diff options
Diffstat (limited to 'arch/xtensa/kernel')
26 files changed, 9111 insertions, 0 deletions
diff --git a/arch/xtensa/kernel/.gitignore b/arch/xtensa/kernel/.gitignore new file mode 100644 index 000000000..c5f676c3c --- /dev/null +++ b/arch/xtensa/kernel/.gitignore @@ -0,0 +1 @@ +vmlinux.lds diff --git a/arch/xtensa/kernel/Makefile b/arch/xtensa/kernel/Makefile new file mode 100644 index 000000000..d3a0f0fd5 --- /dev/null +++ b/arch/xtensa/kernel/Makefile @@ -0,0 +1,40 @@ +# +# Makefile for the Linux/Xtensa kernel. +# + +extra-y := head.o vmlinux.lds + +obj-y := align.o coprocessor.o entry.o irq.o pci-dma.o platform.o process.o \ + ptrace.o setup.o signal.o stacktrace.o syscall.o time.o traps.o \ + vectors.o + +obj-$(CONFIG_KGDB) += xtensa-stub.o +obj-$(CONFIG_PCI) += pci.o +obj-$(CONFIG_MODULES) += xtensa_ksyms.o module.o +obj-$(CONFIG_FUNCTION_TRACER) += mcount.o +obj-$(CONFIG_SMP) += smp.o mxhead.o + +AFLAGS_head.o += -mtext-section-literals + +# In the Xtensa architecture, assembly generates literals which must always +# precede the L32R instruction with a relative offset less than 256 kB. +# Therefore, the .text and .literal section must be combined in parenthesis +# in the linker script, such as: *(.literal .text). +# +# We need to post-process the generated vmlinux.lds scripts to convert +# *(xxx.text) to *(xxx.literal xxx.text) for the following text sections: +# .text .ref.text .*init.text .*exit.text .text.* +# +# Replicate rules in scripts/Makefile.build + +sed-y = -e 's/\*(\(\.[a-z]*it\|\.ref\|\)\.text)/*(\1.literal \1.text)/g' \ + -e 's/\.text\.unlikely/.literal.unlikely .text.unlikely/g' \ + -e 's/\*(\(\.text .*\))/*(.literal \1)/g' \ + -e 's/\*(\(\.text\.[a-z]*\))/*(\1.literal \1)/g' + +quiet_cmd__cpp_lds_S = LDS $@ +cmd__cpp_lds_S = $(CPP) $(cpp_flags) -P -C -Uxtensa -D__ASSEMBLY__ $< \ + | sed $(sed-y) >$@ + +$(obj)/vmlinux.lds: $(src)/vmlinux.lds.S FORCE + $(call if_changed_dep,_cpp_lds_S) diff --git a/arch/xtensa/kernel/align.S b/arch/xtensa/kernel/align.S new file mode 100644 index 000000000..890004af0 --- /dev/null +++ b/arch/xtensa/kernel/align.S @@ -0,0 +1,488 @@ +/* + * arch/xtensa/kernel/align.S + * + * Handle unalignment exceptions in kernel space. + * + * This file is subject to the terms and conditions of the GNU General + * Public License. See the file "COPYING" in the main directory of + * this archive for more details. + * + * Copyright (C) 2001 - 2005 Tensilica, Inc. + * Copyright (C) 2014 Cadence Design Systems Inc. + * + * Rewritten by Chris Zankel <chris@zankel.net> + * + * Based on work from Joe Taylor <joe@tensilica.com, joetylr@yahoo.com> + * and Marc Gauthier <marc@tensilica.com, marc@alimni.uwaterloo.ca> + */ + +#include <linux/linkage.h> +#include <asm/current.h> +#include <asm/asm-offsets.h> +#include <asm/processor.h> + +#if XCHAL_UNALIGNED_LOAD_EXCEPTION || XCHAL_UNALIGNED_STORE_EXCEPTION + +/* First-level exception handler for unaligned exceptions. + * + * Note: This handler works only for kernel exceptions. Unaligned user + * access should get a seg fault. + */ + +/* Big and little endian 16-bit values are located in + * different halves of a register. HWORD_START helps to + * abstract the notion of extracting a 16-bit value from a + * register. + * We also have to define new shifting instructions because + * lsb and msb are on 'opposite' ends in a register for + * different endian machines. + * + * Assume a memory region in ascending address: + * 0 1 2 3|4 5 6 7 + * + * When loading one word into a register, the content of that register is: + * LE 3 2 1 0, 7 6 5 4 + * BE 0 1 2 3, 4 5 6 7 + * + * Masking the bits of the higher/lower address means: + * LE X X 0 0, 0 0 X X + * BE 0 0 X X, X X 0 0 + * + * Shifting to higher/lower addresses, means: + * LE shift left / shift right + * BE shift right / shift left + * + * Extracting 16 bits from a 32 bit reg. value to higher/lower address means: + * LE mask 0 0 X X / shift left + * BE shift left / mask 0 0 X X + */ + +#define UNALIGNED_USER_EXCEPTION + +#if XCHAL_HAVE_BE + +#define HWORD_START 16 +#define INSN_OP0 28 +#define INSN_T 24 +#define INSN_OP1 16 + +.macro __src_b r, w0, w1; src \r, \w0, \w1; .endm +.macro __ssa8 r; ssa8b \r; .endm +.macro __ssa8r r; ssa8l \r; .endm +.macro __sh r, s; srl \r, \s; .endm +.macro __sl r, s; sll \r, \s; .endm +.macro __exth r, s; extui \r, \s, 0, 16; .endm +.macro __extl r, s; slli \r, \s, 16; .endm + +#else + +#define HWORD_START 0 +#define INSN_OP0 0 +#define INSN_T 4 +#define INSN_OP1 12 + +.macro __src_b r, w0, w1; src \r, \w1, \w0; .endm +.macro __ssa8 r; ssa8l \r; .endm +.macro __ssa8r r; ssa8b \r; .endm +.macro __sh r, s; sll \r, \s; .endm +.macro __sl r, s; srl \r, \s; .endm +.macro __exth r, s; slli \r, \s, 16; .endm +.macro __extl r, s; extui \r, \s, 0, 16; .endm + +#endif + +/* + * xxxx xxxx = imm8 field + * yyyy = imm4 field + * ssss = s field + * tttt = t field + * + * 16 0 + * ------------------- + * L32I.N yyyy ssss tttt 1000 + * S32I.N yyyy ssss tttt 1001 + * + * 23 0 + * ----------------------------- + * res 0000 0010 + * L16UI xxxx xxxx 0001 ssss tttt 0010 + * L32I xxxx xxxx 0010 ssss tttt 0010 + * XXX 0011 ssss tttt 0010 + * XXX 0100 ssss tttt 0010 + * S16I xxxx xxxx 0101 ssss tttt 0010 + * S32I xxxx xxxx 0110 ssss tttt 0010 + * XXX 0111 ssss tttt 0010 + * XXX 1000 ssss tttt 0010 + * L16SI xxxx xxxx 1001 ssss tttt 0010 + * XXX 1010 0010 + * **L32AI xxxx xxxx 1011 ssss tttt 0010 unsupported + * XXX 1100 0010 + * XXX 1101 0010 + * XXX 1110 0010 + * **S32RI xxxx xxxx 1111 ssss tttt 0010 unsupported + * ----------------------------- + * ^ ^ ^ + * sub-opcode (NIBBLE_R) -+ | | + * t field (NIBBLE_T) -----------+ | + * major opcode (NIBBLE_OP0) --------------+ + */ + +#define OP0_L32I_N 0x8 /* load immediate narrow */ +#define OP0_S32I_N 0x9 /* store immediate narrow */ +#define OP1_SI_MASK 0x4 /* OP1 bit set for stores */ +#define OP1_SI_BIT 2 /* OP1 bit number for stores */ + +#define OP1_L32I 0x2 +#define OP1_L16UI 0x1 +#define OP1_L16SI 0x9 +#define OP1_L32AI 0xb + +#define OP1_S32I 0x6 +#define OP1_S16I 0x5 +#define OP1_S32RI 0xf + +/* + * Entry condition: + * + * a0: trashed, original value saved on stack (PT_AREG0) + * a1: a1 + * a2: new stack pointer, original in DEPC + * a3: a3 + * depc: a2, original value saved on stack (PT_DEPC) + * excsave_1: dispatch table + * + * PT_DEPC >= VALID_DOUBLE_EXCEPTION_ADDRESS: double exception, DEPC + * < VALID_DOUBLE_EXCEPTION_ADDRESS: regular exception + */ + + +ENTRY(fast_unaligned) + + /* Note: We don't expect the address to be aligned on a word + * boundary. After all, the processor generated that exception + * and it would be a hardware fault. + */ + + /* Save some working register */ + + s32i a4, a2, PT_AREG4 + s32i a5, a2, PT_AREG5 + s32i a6, a2, PT_AREG6 + s32i a7, a2, PT_AREG7 + s32i a8, a2, PT_AREG8 + + rsr a0, depc + s32i a0, a2, PT_AREG2 + s32i a3, a2, PT_AREG3 + + rsr a3, excsave1 + movi a4, fast_unaligned_fixup + s32i a4, a3, EXC_TABLE_FIXUP + + /* Keep value of SAR in a0 */ + + rsr a0, sar + rsr a8, excvaddr # load unaligned memory address + + /* Now, identify one of the following load/store instructions. + * + * The only possible danger of a double exception on the + * following l32i instructions is kernel code in vmalloc + * memory. The processor was just executing at the EPC_1 + * address, and indeed, already fetched the instruction. That + * guarantees a TLB mapping, which hasn't been replaced by + * this unaligned exception handler that uses only static TLB + * mappings. However, high-level interrupt handlers might + * modify TLB entries, so for the generic case, we register a + * TABLE_FIXUP handler here, too. + */ + + /* a3...a6 saved on stack, a2 = SP */ + + /* Extract the instruction that caused the unaligned access. */ + + rsr a7, epc1 # load exception address + movi a3, ~3 + and a3, a3, a7 # mask lower bits + + l32i a4, a3, 0 # load 2 words + l32i a5, a3, 4 + + __ssa8 a7 + __src_b a4, a4, a5 # a4 has the instruction + + /* Analyze the instruction (load or store?). */ + + extui a5, a4, INSN_OP0, 4 # get insn.op0 nibble + +#if XCHAL_HAVE_DENSITY + _beqi a5, OP0_L32I_N, .Lload # L32I.N, jump + addi a6, a5, -OP0_S32I_N + _beqz a6, .Lstore # S32I.N, do a store +#endif + /* 'store indicator bit' not set, jump */ + _bbci.l a4, OP1_SI_BIT + INSN_OP1, .Lload + + /* Store: Jump to table entry to get the value in the source register.*/ + +.Lstore:movi a5, .Lstore_table # table + extui a6, a4, INSN_T, 4 # get source register + addx8 a5, a6, a5 + jx a5 # jump into table + + /* Load: Load memory address. */ + +.Lload: movi a3, ~3 + and a3, a3, a8 # align memory address + + __ssa8 a8 +#ifdef UNALIGNED_USER_EXCEPTION + addi a3, a3, 8 + l32e a5, a3, -8 + l32e a6, a3, -4 +#else + l32i a5, a3, 0 + l32i a6, a3, 4 +#endif + __src_b a3, a5, a6 # a3 has the data word + +#if XCHAL_HAVE_DENSITY + addi a7, a7, 2 # increment PC (assume 16-bit insn) + + extui a5, a4, INSN_OP0, 4 + _beqi a5, OP0_L32I_N, 1f # l32i.n: jump + + addi a7, a7, 1 +#else + addi a7, a7, 3 +#endif + + extui a5, a4, INSN_OP1, 4 + _beqi a5, OP1_L32I, 1f # l32i: jump + + extui a3, a3, 0, 16 # extract lower 16 bits + _beqi a5, OP1_L16UI, 1f + addi a5, a5, -OP1_L16SI + _bnez a5, .Linvalid_instruction_load + + /* sign extend value */ + + slli a3, a3, 16 + srai a3, a3, 16 + + /* Set target register. */ + +1: + extui a4, a4, INSN_T, 4 # extract target register + movi a5, .Lload_table + addx8 a4, a4, a5 + jx a4 # jump to entry for target register + + .align 8 +.Lload_table: + s32i a3, a2, PT_AREG0; _j .Lexit; .align 8 + mov a1, a3; _j .Lexit; .align 8 # fishy?? + s32i a3, a2, PT_AREG2; _j .Lexit; .align 8 + s32i a3, a2, PT_AREG3; _j .Lexit; .align 8 + s32i a3, a2, PT_AREG4; _j .Lexit; .align 8 + s32i a3, a2, PT_AREG5; _j .Lexit; .align 8 + s32i a3, a2, PT_AREG6; _j .Lexit; .align 8 + s32i a3, a2, PT_AREG7; _j .Lexit; .align 8 + s32i a3, a2, PT_AREG8; _j .Lexit; .align 8 + mov a9, a3 ; _j .Lexit; .align 8 + mov a10, a3 ; _j .Lexit; .align 8 + mov a11, a3 ; _j .Lexit; .align 8 + mov a12, a3 ; _j .Lexit; .align 8 + mov a13, a3 ; _j .Lexit; .align 8 + mov a14, a3 ; _j .Lexit; .align 8 + mov a15, a3 ; _j .Lexit; .align 8 + +.Lstore_table: + l32i a3, a2, PT_AREG0; _j 1f; .align 8 + mov a3, a1; _j 1f; .align 8 # fishy?? + l32i a3, a2, PT_AREG2; _j 1f; .align 8 + l32i a3, a2, PT_AREG3; _j 1f; .align 8 + l32i a3, a2, PT_AREG4; _j 1f; .align 8 + l32i a3, a2, PT_AREG5; _j 1f; .align 8 + l32i a3, a2, PT_AREG6; _j 1f; .align 8 + l32i a3, a2, PT_AREG7; _j 1f; .align 8 + l32i a3, a2, PT_AREG8; _j 1f; .align 8 + mov a3, a9 ; _j 1f; .align 8 + mov a3, a10 ; _j 1f; .align 8 + mov a3, a11 ; _j 1f; .align 8 + mov a3, a12 ; _j 1f; .align 8 + mov a3, a13 ; _j 1f; .align 8 + mov a3, a14 ; _j 1f; .align 8 + mov a3, a15 ; _j 1f; .align 8 + + /* We cannot handle this exception. */ + + .extern _kernel_exception +.Linvalid_instruction_load: +.Linvalid_instruction_store: + + movi a4, 0 + rsr a3, excsave1 + s32i a4, a3, EXC_TABLE_FIXUP + + /* Restore a4...a8 and SAR, set SP, and jump to default exception. */ + + l32i a8, a2, PT_AREG8 + l32i a7, a2, PT_AREG7 + l32i a6, a2, PT_AREG6 + l32i a5, a2, PT_AREG5 + l32i a4, a2, PT_AREG4 + wsr a0, sar + mov a1, a2 + + rsr a0, ps + bbsi.l a0, PS_UM_BIT, 2f # jump if user mode + + movi a0, _kernel_exception + jx a0 + +2: movi a0, _user_exception + jx a0 + +1: # a7: instruction pointer, a4: instruction, a3: value + + movi a6, 0 # mask: ffffffff:00000000 + +#if XCHAL_HAVE_DENSITY + addi a7, a7, 2 # incr. PC,assume 16-bit instruction + + extui a5, a4, INSN_OP0, 4 # extract OP0 + addi a5, a5, -OP0_S32I_N + _beqz a5, 1f # s32i.n: jump + + addi a7, a7, 1 # increment PC, 32-bit instruction +#else + addi a7, a7, 3 # increment PC, 32-bit instruction +#endif + + extui a5, a4, INSN_OP1, 4 # extract OP1 + _beqi a5, OP1_S32I, 1f # jump if 32 bit store + _bnei a5, OP1_S16I, .Linvalid_instruction_store + + movi a5, -1 + __extl a3, a3 # get 16-bit value + __exth a6, a5 # get 16-bit mask ffffffff:ffff0000 + + /* Get memory address */ + +1: + movi a4, ~3 + and a4, a4, a8 # align memory address + + /* Insert value into memory */ + + movi a5, -1 # mask: ffffffff:XXXX0000 +#ifdef UNALIGNED_USER_EXCEPTION + addi a4, a4, 8 +#endif + + __ssa8r a8 + __src_b a8, a5, a6 # lo-mask F..F0..0 (BE) 0..0F..F (LE) + __src_b a6, a6, a5 # hi-mask 0..0F..F (BE) F..F0..0 (LE) +#ifdef UNALIGNED_USER_EXCEPTION + l32e a5, a4, -8 +#else + l32i a5, a4, 0 # load lower address word +#endif + and a5, a5, a8 # mask + __sh a8, a3 # shift value + or a5, a5, a8 # or with original value +#ifdef UNALIGNED_USER_EXCEPTION + s32e a5, a4, -8 + l32e a8, a4, -4 +#else + s32i a5, a4, 0 # store + l32i a8, a4, 4 # same for upper address word +#endif + __sl a5, a3 + and a6, a8, a6 + or a6, a6, a5 +#ifdef UNALIGNED_USER_EXCEPTION + s32e a6, a4, -4 +#else + s32i a6, a4, 4 +#endif + +.Lexit: +#if XCHAL_HAVE_LOOPS + rsr a4, lend # check if we reached LEND + bne a7, a4, 1f + rsr a4, lcount # and LCOUNT != 0 + beqz a4, 1f + addi a4, a4, -1 # decrement LCOUNT and set + rsr a7, lbeg # set PC to LBEGIN + wsr a4, lcount +#endif + +1: wsr a7, epc1 # skip emulated instruction + + /* Update icount if we're single-stepping in userspace. */ + rsr a4, icountlevel + beqz a4, 1f + bgeui a4, LOCKLEVEL + 1, 1f + rsr a4, icount + addi a4, a4, 1 + wsr a4, icount +1: + movi a4, 0 + rsr a3, excsave1 + s32i a4, a3, EXC_TABLE_FIXUP + + /* Restore working register */ + + l32i a8, a2, PT_AREG8 + l32i a7, a2, PT_AREG7 + l32i a6, a2, PT_AREG6 + l32i a5, a2, PT_AREG5 + l32i a4, a2, PT_AREG4 + l32i a3, a2, PT_AREG3 + + /* restore SAR and return */ + + wsr a0, sar + l32i a0, a2, PT_AREG0 + l32i a2, a2, PT_AREG2 + rfe + +ENDPROC(fast_unaligned) + +ENTRY(fast_unaligned_fixup) + + l32i a2, a3, EXC_TABLE_DOUBLE_SAVE + wsr a3, excsave1 + + l32i a8, a2, PT_AREG8 + l32i a7, a2, PT_AREG7 + l32i a6, a2, PT_AREG6 + l32i a5, a2, PT_AREG5 + l32i a4, a2, PT_AREG4 + l32i a0, a2, PT_AREG2 + xsr a0, depc # restore depc and a0 + wsr a0, sar + + rsr a0, exccause + s32i a0, a2, PT_DEPC # mark as a regular exception + + rsr a0, ps + bbsi.l a0, PS_UM_BIT, 1f # jump if user mode + + rsr a0, exccause + addx4 a0, a0, a3 # find entry in table + l32i a0, a0, EXC_TABLE_FAST_KERNEL # load handler + l32i a3, a2, PT_AREG3 + jx a0 +1: + rsr a0, exccause + addx4 a0, a0, a3 # find entry in table + l32i a0, a0, EXC_TABLE_FAST_USER # load handler + l32i a3, a2, PT_AREG3 + jx a0 + +ENDPROC(fast_unaligned_fixup) + +#endif /* XCHAL_UNALIGNED_LOAD_EXCEPTION || XCHAL_UNALIGNED_STORE_EXCEPTION */ diff --git a/arch/xtensa/kernel/asm-offsets.c b/arch/xtensa/kernel/asm-offsets.c new file mode 100644 index 000000000..b123ace3b --- /dev/null +++ b/arch/xtensa/kernel/asm-offsets.c @@ -0,0 +1,121 @@ +/* + * arch/xtensa/kernel/asm-offsets.c + * + * Generates definitions from c-type structures used by assembly sources. + * + * This file is subject to the terms and conditions of the GNU General Public + * License. See the file "COPYING" in the main directory of this archive + * for more details. + * + * Copyright (C) 2005 Tensilica Inc. + * + * Chris Zankel <chris@zankel.net> + */ + +#include <asm/processor.h> +#include <asm/coprocessor.h> + +#include <linux/types.h> +#include <linux/stddef.h> +#include <linux/thread_info.h> +#include <linux/ptrace.h> +#include <linux/mm.h> +#include <linux/kbuild.h> + +#include <asm/ptrace.h> +#include <asm/uaccess.h> + +int main(void) +{ + /* struct pt_regs */ + DEFINE(PT_PC, offsetof (struct pt_regs, pc)); + DEFINE(PT_PS, offsetof (struct pt_regs, ps)); + DEFINE(PT_DEPC, offsetof (struct pt_regs, depc)); + DEFINE(PT_EXCCAUSE, offsetof (struct pt_regs, exccause)); + DEFINE(PT_EXCVADDR, offsetof (struct pt_regs, excvaddr)); + DEFINE(PT_DEBUGCAUSE, offsetof (struct pt_regs, debugcause)); + DEFINE(PT_WMASK, offsetof (struct pt_regs, wmask)); + DEFINE(PT_LBEG, offsetof (struct pt_regs, lbeg)); + DEFINE(PT_LEND, offsetof (struct pt_regs, lend)); + DEFINE(PT_LCOUNT, offsetof (struct pt_regs, lcount)); + DEFINE(PT_SAR, offsetof (struct pt_regs, sar)); + DEFINE(PT_ICOUNTLEVEL, offsetof (struct pt_regs, icountlevel)); + DEFINE(PT_SYSCALL, offsetof (struct pt_regs, syscall)); + DEFINE(PT_SCOMPARE1, offsetof(struct pt_regs, scompare1)); + DEFINE(PT_THREADPTR, offsetof(struct pt_regs, threadptr)); + DEFINE(PT_AREG, offsetof (struct pt_regs, areg[0])); + DEFINE(PT_AREG0, offsetof (struct pt_regs, areg[0])); + DEFINE(PT_AREG1, offsetof (struct pt_regs, areg[1])); + DEFINE(PT_AREG2, offsetof (struct pt_regs, areg[2])); + DEFINE(PT_AREG3, offsetof (struct pt_regs, areg[3])); + DEFINE(PT_AREG4, offsetof (struct pt_regs, areg[4])); + DEFINE(PT_AREG5, offsetof (struct pt_regs, areg[5])); + DEFINE(PT_AREG6, offsetof (struct pt_regs, areg[6])); + DEFINE(PT_AREG7, offsetof (struct pt_regs, areg[7])); + DEFINE(PT_AREG8, offsetof (struct pt_regs, areg[8])); + DEFINE(PT_AREG9, offsetof (struct pt_regs, areg[9])); + DEFINE(PT_AREG10, offsetof (struct pt_regs, areg[10])); + DEFINE(PT_AREG11, offsetof (struct pt_regs, areg[11])); + DEFINE(PT_AREG12, offsetof (struct pt_regs, areg[12])); + DEFINE(PT_AREG13, offsetof (struct pt_regs, areg[13])); + DEFINE(PT_AREG14, offsetof (struct pt_regs, areg[14])); + DEFINE(PT_AREG15, offsetof (struct pt_regs, areg[15])); + DEFINE(PT_WINDOWBASE, offsetof (struct pt_regs, windowbase)); + DEFINE(PT_WINDOWSTART, offsetof(struct pt_regs, windowstart)); + DEFINE(PT_SIZE, sizeof(struct pt_regs)); + DEFINE(PT_AREG_END, offsetof (struct pt_regs, areg[XCHAL_NUM_AREGS])); + DEFINE(PT_USER_SIZE, offsetof(struct pt_regs, areg[XCHAL_NUM_AREGS])); + DEFINE(PT_XTREGS_OPT, offsetof(struct pt_regs, xtregs_opt)); + DEFINE(XTREGS_OPT_SIZE, sizeof(xtregs_opt_t)); + + /* struct task_struct */ + DEFINE(TASK_PTRACE, offsetof (struct task_struct, ptrace)); + DEFINE(TASK_MM, offsetof (struct task_struct, mm)); + DEFINE(TASK_ACTIVE_MM, offsetof (struct task_struct, active_mm)); + DEFINE(TASK_PID, offsetof (struct task_struct, pid)); + DEFINE(TASK_THREAD, offsetof (struct task_struct, thread)); + DEFINE(TASK_THREAD_INFO, offsetof (struct task_struct, stack)); + DEFINE(TASK_STRUCT_SIZE, sizeof (struct task_struct)); + + /* offsets in thread_info struct */ + OFFSET(TI_TASK, thread_info, task); + OFFSET(TI_FLAGS, thread_info, flags); + OFFSET(TI_STSTUS, thread_info, status); + OFFSET(TI_CPU, thread_info, cpu); + OFFSET(TI_PRE_COUNT, thread_info, preempt_count); + OFFSET(TI_ADDR_LIMIT, thread_info, addr_limit); + + /* struct thread_info (offset from start_struct) */ + DEFINE(THREAD_RA, offsetof (struct task_struct, thread.ra)); + DEFINE(THREAD_SP, offsetof (struct task_struct, thread.sp)); + DEFINE(THREAD_CPENABLE, offsetof (struct thread_info, cpenable)); +#if XTENSA_HAVE_COPROCESSORS + DEFINE(THREAD_XTREGS_CP0, offsetof (struct thread_info, xtregs_cp)); + DEFINE(THREAD_XTREGS_CP1, offsetof (struct thread_info, xtregs_cp)); + DEFINE(THREAD_XTREGS_CP2, offsetof (struct thread_info, xtregs_cp)); + DEFINE(THREAD_XTREGS_CP3, offsetof (struct thread_info, xtregs_cp)); + DEFINE(THREAD_XTREGS_CP4, offsetof (struct thread_info, xtregs_cp)); + DEFINE(THREAD_XTREGS_CP5, offsetof (struct thread_info, xtregs_cp)); + DEFINE(THREAD_XTREGS_CP6, offsetof (struct thread_info, xtregs_cp)); + DEFINE(THREAD_XTREGS_CP7, offsetof (struct thread_info, xtregs_cp)); +#endif + DEFINE(THREAD_XTREGS_USER, offsetof (struct thread_info, xtregs_user)); + DEFINE(XTREGS_USER_SIZE, sizeof(xtregs_user_t)); + DEFINE(THREAD_CURRENT_DS, offsetof (struct task_struct, \ + thread.current_ds)); + + /* struct mm_struct */ + DEFINE(MM_USERS, offsetof(struct mm_struct, mm_users)); + DEFINE(MM_PGD, offsetof (struct mm_struct, pgd)); + DEFINE(MM_CONTEXT, offsetof (struct mm_struct, context)); + + /* struct page */ + DEFINE(PAGE_FLAGS, offsetof(struct page, flags)); + + /* constants */ + DEFINE(_CLONE_VM, CLONE_VM); + DEFINE(_CLONE_UNTRACED, CLONE_UNTRACED); + DEFINE(PG_ARCH_1, PG_arch_1); + + return 0; +} diff --git a/arch/xtensa/kernel/coprocessor.S b/arch/xtensa/kernel/coprocessor.S new file mode 100644 index 000000000..a482df5df --- /dev/null +++ b/arch/xtensa/kernel/coprocessor.S @@ -0,0 +1,355 @@ +/* + * arch/xtensa/kernel/coprocessor.S + * + * Xtensa processor configuration-specific table of coprocessor and + * other custom register layout information. + * + * This file is subject to the terms and conditions of the GNU General Public + * License. See the file "COPYING" in the main directory of this archive + * for more details. + * + * Copyright (C) 2003 - 2007 Tensilica Inc. + */ + + +#include <linux/linkage.h> +#include <asm/asm-offsets.h> +#include <asm/processor.h> +#include <asm/coprocessor.h> +#include <asm/thread_info.h> +#include <asm/uaccess.h> +#include <asm/unistd.h> +#include <asm/ptrace.h> +#include <asm/current.h> +#include <asm/pgtable.h> +#include <asm/page.h> +#include <asm/signal.h> +#include <asm/tlbflush.h> + +/* + * Entry condition: + * + * a0: trashed, original value saved on stack (PT_AREG0) + * a1: a1 + * a2: new stack pointer, original in DEPC + * a3: a3 + * depc: a2, original value saved on stack (PT_DEPC) + * excsave_1: dispatch table + * + * PT_DEPC >= VALID_DOUBLE_EXCEPTION_ADDRESS: double exception, DEPC + * < VALID_DOUBLE_EXCEPTION_ADDRESS: regular exception + */ + +/* IO protection is currently unsupported. */ + +ENTRY(fast_io_protect) + + wsr a0, excsave1 + movi a0, unrecoverable_exception + callx0 a0 + +ENDPROC(fast_io_protect) + +#if XTENSA_HAVE_COPROCESSORS + +/* + * Macros for lazy context switch. + */ + +#define SAVE_CP_REGS(x) \ + .align 4; \ + .Lsave_cp_regs_cp##x: \ + .if XTENSA_HAVE_COPROCESSOR(x); \ + xchal_cp##x##_store a2 a4 a5 a6 a7; \ + .endif; \ + jx a0 + +#define SAVE_CP_REGS_TAB(x) \ + .if XTENSA_HAVE_COPROCESSOR(x); \ + .long .Lsave_cp_regs_cp##x - .Lsave_cp_regs_jump_table; \ + .else; \ + .long 0; \ + .endif; \ + .long THREAD_XTREGS_CP##x + + +#define LOAD_CP_REGS(x) \ + .align 4; \ + .Lload_cp_regs_cp##x: \ + .if XTENSA_HAVE_COPROCESSOR(x); \ + xchal_cp##x##_load a2 a4 a5 a6 a7; \ + .endif; \ + jx a0 + +#define LOAD_CP_REGS_TAB(x) \ + .if XTENSA_HAVE_COPROCESSOR(x); \ + .long .Lload_cp_regs_cp##x - .Lload_cp_regs_jump_table; \ + .else; \ + .long 0; \ + .endif; \ + .long THREAD_XTREGS_CP##x + + SAVE_CP_REGS(0) + SAVE_CP_REGS(1) + SAVE_CP_REGS(2) + SAVE_CP_REGS(3) + SAVE_CP_REGS(4) + SAVE_CP_REGS(5) + SAVE_CP_REGS(6) + SAVE_CP_REGS(7) + + LOAD_CP_REGS(0) + LOAD_CP_REGS(1) + LOAD_CP_REGS(2) + LOAD_CP_REGS(3) + LOAD_CP_REGS(4) + LOAD_CP_REGS(5) + LOAD_CP_REGS(6) + LOAD_CP_REGS(7) + + .align 4 +.Lsave_cp_regs_jump_table: + SAVE_CP_REGS_TAB(0) + SAVE_CP_REGS_TAB(1) + SAVE_CP_REGS_TAB(2) + SAVE_CP_REGS_TAB(3) + SAVE_CP_REGS_TAB(4) + SAVE_CP_REGS_TAB(5) + SAVE_CP_REGS_TAB(6) + SAVE_CP_REGS_TAB(7) + +.Lload_cp_regs_jump_table: + LOAD_CP_REGS_TAB(0) + LOAD_CP_REGS_TAB(1) + LOAD_CP_REGS_TAB(2) + LOAD_CP_REGS_TAB(3) + LOAD_CP_REGS_TAB(4) + LOAD_CP_REGS_TAB(5) + LOAD_CP_REGS_TAB(6) + LOAD_CP_REGS_TAB(7) + +/* + * coprocessor_save(buffer, index) + * a2 a3 + * coprocessor_load(buffer, index) + * a2 a3 + * + * Save or load coprocessor registers for coprocessor 'index'. + * The register values are saved to or loaded from them 'buffer' address. + * + * Note that these functions don't update the coprocessor_owner information! + * + */ + +ENTRY(coprocessor_save) + + entry a1, 32 + s32i a0, a1, 0 + movi a0, .Lsave_cp_regs_jump_table + addx8 a3, a3, a0 + l32i a3, a3, 0 + beqz a3, 1f + add a0, a0, a3 + callx0 a0 +1: l32i a0, a1, 0 + retw + +ENDPROC(coprocessor_save) + +ENTRY(coprocessor_load) + + entry a1, 32 + s32i a0, a1, 0 + movi a0, .Lload_cp_regs_jump_table + addx4 a3, a3, a0 + l32i a3, a3, 0 + beqz a3, 1f + add a0, a0, a3 + callx0 a0 +1: l32i a0, a1, 0 + retw + +ENDPROC(coprocessor_load) + +/* + * coprocessor_flush(struct task_info*, index) + * a2 a3 + * coprocessor_restore(struct task_info*, index) + * a2 a3 + * + * Save or load coprocessor registers for coprocessor 'index'. + * The register values are saved to or loaded from the coprocessor area + * inside the task_info structure. + * + * Note that these functions don't update the coprocessor_owner information! + * + */ + + +ENTRY(coprocessor_flush) + + entry a1, 32 + s32i a0, a1, 0 + movi a0, .Lsave_cp_regs_jump_table + addx8 a3, a3, a0 + l32i a4, a3, 4 + l32i a3, a3, 0 + add a2, a2, a4 + beqz a3, 1f + add a0, a0, a3 + callx0 a0 +1: l32i a0, a1, 0 + retw + +ENDPROC(coprocessor_flush) + +ENTRY(coprocessor_restore) + entry a1, 32 + s32i a0, a1, 0 + movi a0, .Lload_cp_regs_jump_table + addx4 a3, a3, a0 + l32i a4, a3, 4 + l32i a3, a3, 0 + add a2, a2, a4 + beqz a3, 1f + add a0, a0, a3 + callx0 a0 +1: l32i a0, a1, 0 + retw + +ENDPROC(coprocessor_restore) + +/* + * Entry condition: + * + * a0: trashed, original value saved on stack (PT_AREG0) + * a1: a1 + * a2: new stack pointer, original in DEPC + * a3: a3 + * depc: a2, original value saved on stack (PT_DEPC) + * excsave_1: dispatch table + * + * PT_DEPC >= VALID_DOUBLE_EXCEPTION_ADDRESS: double exception, DEPC + * < VALID_DOUBLE_EXCEPTION_ADDRESS: regular exception + */ + +ENTRY(fast_coprocessor_double) + + wsr a0, excsave1 + movi a0, unrecoverable_exception + callx0 a0 + +ENDPROC(fast_coprocessor_double) + +ENTRY(fast_coprocessor) + + /* Save remaining registers a1-a3 and SAR */ + + s32i a3, a2, PT_AREG3 + rsr a3, sar + s32i a1, a2, PT_AREG1 + s32i a3, a2, PT_SAR + mov a1, a2 + rsr a2, depc + s32i a2, a1, PT_AREG2 + + /* + * The hal macros require up to 4 temporary registers. We use a3..a6. + */ + + s32i a4, a1, PT_AREG4 + s32i a5, a1, PT_AREG5 + s32i a6, a1, PT_AREG6 + + /* Find coprocessor number. Subtract first CP EXCCAUSE from EXCCAUSE */ + + rsr a3, exccause + addi a3, a3, -EXCCAUSE_COPROCESSOR0_DISABLED + + /* Set corresponding CPENABLE bit -> (sar:cp-index, a3: 1<<cp-index)*/ + + ssl a3 # SAR: 32 - coprocessor_number + movi a2, 1 + rsr a0, cpenable + sll a2, a2 + or a0, a0, a2 + wsr a0, cpenable + rsync + + /* Retrieve previous owner. (a3 still holds CP number) */ + + movi a0, coprocessor_owner # list of owners + addx4 a0, a3, a0 # entry for CP + l32i a4, a0, 0 + + beqz a4, 1f # skip 'save' if no previous owner + + /* Disable coprocessor for previous owner. (a2 = 1 << CP number) */ + + l32i a5, a4, THREAD_CPENABLE + xor a5, a5, a2 # (1 << cp-id) still in a2 + s32i a5, a4, THREAD_CPENABLE + + /* + * Get context save area and 'call' save routine. + * (a4 still holds previous owner (thread_info), a3 CP number) + */ + + movi a5, .Lsave_cp_regs_jump_table + movi a0, 2f # a0: 'return' address + addx8 a3, a3, a5 # a3: coprocessor number + l32i a2, a3, 4 # a2: xtregs offset + l32i a3, a3, 0 # a3: jump offset + add a2, a2, a4 + add a4, a3, a5 # a4: address of save routine + jx a4 + + /* Note that only a0 and a1 were preserved. */ + +2: rsr a3, exccause + addi a3, a3, -EXCCAUSE_COPROCESSOR0_DISABLED + movi a0, coprocessor_owner + addx4 a0, a3, a0 + + /* Set new 'owner' (a0 points to the CP owner, a3 contains the CP nr) */ + +1: GET_THREAD_INFO (a4, a1) + s32i a4, a0, 0 + + /* Get context save area and 'call' load routine. */ + + movi a5, .Lload_cp_regs_jump_table + movi a0, 1f + addx8 a3, a3, a5 + l32i a2, a3, 4 # a2: xtregs offset + l32i a3, a3, 0 # a3: jump offset + add a2, a2, a4 + add a4, a3, a5 + jx a4 + + /* Restore all registers and return from exception handler. */ + +1: l32i a6, a1, PT_AREG6 + l32i a5, a1, PT_AREG5 + l32i a4, a1, PT_AREG4 + + l32i a0, a1, PT_SAR + l32i a3, a1, PT_AREG3 + l32i a2, a1, PT_AREG2 + wsr a0, sar + l32i a0, a1, PT_AREG0 + l32i a1, a1, PT_AREG1 + + rfe + +ENDPROC(fast_coprocessor) + + .data + +ENTRY(coprocessor_owner) + + .fill XCHAL_CP_MAX, 4, 0 + +END(coprocessor_owner) + +#endif /* XTENSA_HAVE_COPROCESSORS */ diff --git a/arch/xtensa/kernel/entry.S b/arch/xtensa/kernel/entry.S new file mode 100644 index 000000000..82bbfa5a0 --- /dev/null +++ b/arch/xtensa/kernel/entry.S @@ -0,0 +1,1938 @@ +/* + * arch/xtensa/kernel/entry.S + * + * Low-level exception handling + * + * This file is subject to the terms and conditions of the GNU General Public + * License. See the file "COPYING" in the main directory of this archive + * for more details. + * + * Copyright (C) 2004 - 2008 by Tensilica Inc. + * + * Chris Zankel <chris@zankel.net> + * + */ + +#include <linux/linkage.h> +#include <asm/asm-offsets.h> +#include <asm/processor.h> +#include <asm/coprocessor.h> +#include <asm/thread_info.h> +#include <asm/uaccess.h> +#include <asm/unistd.h> +#include <asm/ptrace.h> +#include <asm/current.h> +#include <asm/pgtable.h> +#include <asm/page.h> +#include <asm/signal.h> +#include <asm/tlbflush.h> +#include <variant/tie-asm.h> + +/* Unimplemented features. */ + +#undef KERNEL_STACK_OVERFLOW_CHECK + +/* Not well tested. + * + * - fast_coprocessor + */ + +/* + * Macro to find first bit set in WINDOWBASE from the left + 1 + * + * 100....0 -> 1 + * 010....0 -> 2 + * 000....1 -> WSBITS + */ + + .macro ffs_ws bit mask + +#if XCHAL_HAVE_NSA + nsau \bit, \mask # 32-WSBITS ... 31 (32 iff 0) + addi \bit, \bit, WSBITS - 32 + 1 # uppest bit set -> return 1 +#else + movi \bit, WSBITS +#if WSBITS > 16 + _bltui \mask, 0x10000, 99f + addi \bit, \bit, -16 + extui \mask, \mask, 16, 16 +#endif +#if WSBITS > 8 +99: _bltui \mask, 0x100, 99f + addi \bit, \bit, -8 + srli \mask, \mask, 8 +#endif +99: _bltui \mask, 0x10, 99f + addi \bit, \bit, -4 + srli \mask, \mask, 4 +99: _bltui \mask, 0x4, 99f + addi \bit, \bit, -2 + srli \mask, \mask, 2 +99: _bltui \mask, 0x2, 99f + addi \bit, \bit, -1 +99: + +#endif + .endm + +/* ----------------- DEFAULT FIRST LEVEL EXCEPTION HANDLERS ----------------- */ + +/* + * First-level exception handler for user exceptions. + * Save some special registers, extra states and all registers in the AR + * register file that were in use in the user task, and jump to the common + * exception code. + * We save SAR (used to calculate WMASK), and WB and WS (we don't have to + * save them for kernel exceptions). + * + * Entry condition for user_exception: + * + * a0: trashed, original value saved on stack (PT_AREG0) + * a1: a1 + * a2: new stack pointer, original value in depc + * a3: a3 + * depc: a2, original value saved on stack (PT_DEPC) + * excsave1: dispatch table + * + * PT_DEPC >= VALID_DOUBLE_EXCEPTION_ADDRESS: double exception, DEPC + * < VALID_DOUBLE_EXCEPTION_ADDRESS: regular exception + * + * Entry condition for _user_exception: + * + * a0-a3 and depc have been saved to PT_AREG0...PT_AREG3 and PT_DEPC + * excsave has been restored, and + * stack pointer (a1) has been set. + * + * Note: _user_exception might be at an odd address. Don't use call0..call12 + */ + +ENTRY(user_exception) + + /* Save a1, a2, a3, and set SP. */ + + rsr a0, depc + s32i a1, a2, PT_AREG1 + s32i a0, a2, PT_AREG2 + s32i a3, a2, PT_AREG3 + mov a1, a2 + + .globl _user_exception +_user_exception: + + /* Save SAR and turn off single stepping */ + + movi a2, 0 + rsr a3, sar + xsr a2, icountlevel + s32i a3, a1, PT_SAR + s32i a2, a1, PT_ICOUNTLEVEL + +#if XCHAL_HAVE_THREADPTR + rur a2, threadptr + s32i a2, a1, PT_THREADPTR +#endif + + /* Rotate ws so that the current windowbase is at bit0. */ + /* Assume ws = xxwww1yyyy. Rotate ws right, so that a2 = yyyyxxwww1 */ + + rsr a2, windowbase + rsr a3, windowstart + ssr a2 + s32i a2, a1, PT_WINDOWBASE + s32i a3, a1, PT_WINDOWSTART + slli a2, a3, 32-WSBITS + src a2, a3, a2 + srli a2, a2, 32-WSBITS + s32i a2, a1, PT_WMASK # needed for restoring registers + + /* Save only live registers. */ + + _bbsi.l a2, 1, 1f + s32i a4, a1, PT_AREG4 + s32i a5, a1, PT_AREG5 + s32i a6, a1, PT_AREG6 + s32i a7, a1, PT_AREG7 + _bbsi.l a2, 2, 1f + s32i a8, a1, PT_AREG8 + s32i a9, a1, PT_AREG9 + s32i a10, a1, PT_AREG10 + s32i a11, a1, PT_AREG11 + _bbsi.l a2, 3, 1f + s32i a12, a1, PT_AREG12 + s32i a13, a1, PT_AREG13 + s32i a14, a1, PT_AREG14 + s32i a15, a1, PT_AREG15 + _bnei a2, 1, 1f # only one valid frame? + + /* Only one valid frame, skip saving regs. */ + + j 2f + + /* Save the remaining registers. + * We have to save all registers up to the first '1' from + * the right, except the current frame (bit 0). + * Assume a2 is: 001001000110001 + * All register frames starting from the top field to the marked '1' + * must be saved. + */ + +1: addi a3, a2, -1 # eliminate '1' in bit 0: yyyyxxww0 + neg a3, a3 # yyyyxxww0 -> YYYYXXWW1+1 + and a3, a3, a2 # max. only one bit is set + + /* Find number of frames to save */ + + ffs_ws a0, a3 # number of frames to the '1' from left + + /* Store information into WMASK: + * bits 0..3: xxx1 masked lower 4 bits of the rotated windowstart, + * bits 4...: number of valid 4-register frames + */ + + slli a3, a0, 4 # number of frames to save in bits 8..4 + extui a2, a2, 0, 4 # mask for the first 16 registers + or a2, a3, a2 + s32i a2, a1, PT_WMASK # needed when we restore the reg-file + + /* Save 4 registers at a time */ + +1: rotw -1 + s32i a0, a5, PT_AREG_END - 16 + s32i a1, a5, PT_AREG_END - 12 + s32i a2, a5, PT_AREG_END - 8 + s32i a3, a5, PT_AREG_END - 4 + addi a0, a4, -1 + addi a1, a5, -16 + _bnez a0, 1b + + /* WINDOWBASE still in SAR! */ + + rsr a2, sar # original WINDOWBASE + movi a3, 1 + ssl a2 + sll a3, a3 + wsr a3, windowstart # set corresponding WINDOWSTART bit + wsr a2, windowbase # and WINDOWSTART + rsync + + /* We are back to the original stack pointer (a1) */ + +2: /* Now, jump to the common exception handler. */ + + j common_exception + +ENDPROC(user_exception) + +/* + * First-level exit handler for kernel exceptions + * Save special registers and the live window frame. + * Note: Even though we changes the stack pointer, we don't have to do a + * MOVSP here, as we do that when we return from the exception. + * (See comment in the kernel exception exit code) + * + * Entry condition for kernel_exception: + * + * a0: trashed, original value saved on stack (PT_AREG0) + * a1: a1 + * a2: new stack pointer, original in DEPC + * a3: a3 + * depc: a2, original value saved on stack (PT_DEPC) + * excsave_1: dispatch table + * + * PT_DEPC >= VALID_DOUBLE_EXCEPTION_ADDRESS: double exception, DEPC + * < VALID_DOUBLE_EXCEPTION_ADDRESS: regular exception + * + * Entry condition for _kernel_exception: + * + * a0-a3 and depc have been saved to PT_AREG0...PT_AREG3 and PT_DEPC + * excsave has been restored, and + * stack pointer (a1) has been set. + * + * Note: _kernel_exception might be at an odd address. Don't use call0..call12 + */ + +ENTRY(kernel_exception) + + /* Save a1, a2, a3, and set SP. */ + + rsr a0, depc # get a2 + s32i a1, a2, PT_AREG1 + s32i a0, a2, PT_AREG2 + s32i a3, a2, PT_AREG3 + mov a1, a2 + + .globl _kernel_exception +_kernel_exception: + + /* Save SAR and turn off single stepping */ + + movi a2, 0 + rsr a3, sar + xsr a2, icountlevel + s32i a3, a1, PT_SAR + s32i a2, a1, PT_ICOUNTLEVEL + + /* Rotate ws so that the current windowbase is at bit0. */ + /* Assume ws = xxwww1yyyy. Rotate ws right, so that a2 = yyyyxxwww1 */ + + rsr a2, windowbase # don't need to save these, we only + rsr a3, windowstart # need shifted windowstart: windowmask + ssr a2 + slli a2, a3, 32-WSBITS + src a2, a3, a2 + srli a2, a2, 32-WSBITS + s32i a2, a1, PT_WMASK # needed for kernel_exception_exit + + /* Save only the live window-frame */ + + _bbsi.l a2, 1, 1f + s32i a4, a1, PT_AREG4 + s32i a5, a1, PT_AREG5 + s32i a6, a1, PT_AREG6 + s32i a7, a1, PT_AREG7 + _bbsi.l a2, 2, 1f + s32i a8, a1, PT_AREG8 + s32i a9, a1, PT_AREG9 + s32i a10, a1, PT_AREG10 + s32i a11, a1, PT_AREG11 + _bbsi.l a2, 3, 1f + s32i a12, a1, PT_AREG12 + s32i a13, a1, PT_AREG13 + s32i a14, a1, PT_AREG14 + s32i a15, a1, PT_AREG15 + +1: + +#ifdef KERNEL_STACK_OVERFLOW_CHECK + + /* Stack overflow check, for debugging */ + extui a2, a1, TASK_SIZE_BITS,XX + movi a3, SIZE?? + _bge a2, a3, out_of_stack_panic + +#endif + +/* + * This is the common exception handler. + * We get here from the user exception handler or simply by falling through + * from the kernel exception handler. + * Save the remaining special registers, switch to kernel mode, and jump + * to the second-level exception handler. + * + */ + +common_exception: + + /* Save some registers, disable loops and clear the syscall flag. */ + + rsr a2, debugcause + rsr a3, epc1 + s32i a2, a1, PT_DEBUGCAUSE + s32i a3, a1, PT_PC + + movi a2, -1 + rsr a3, excvaddr + s32i a2, a1, PT_SYSCALL + movi a2, 0 + s32i a3, a1, PT_EXCVADDR + xsr a2, lcount + s32i a2, a1, PT_LCOUNT + + /* It is now save to restore the EXC_TABLE_FIXUP variable. */ + + rsr a0, exccause + movi a3, 0 + rsr a2, excsave1 + s32i a0, a1, PT_EXCCAUSE + s32i a3, a2, EXC_TABLE_FIXUP + + /* All unrecoverable states are saved on stack, now, and a1 is valid, + * so we can allow exceptions and interrupts (*) again. + * Set PS(EXCM = 0, UM = 0, RING = 0, OWB = 0, WOE = 1, INTLEVEL = X) + * + * (*) We only allow interrupts if they were previously enabled and + * we're not handling an IRQ + */ + + rsr a3, ps + addi a0, a0, -EXCCAUSE_LEVEL1_INTERRUPT + movi a2, LOCKLEVEL + extui a3, a3, PS_INTLEVEL_SHIFT, PS_INTLEVEL_WIDTH + # a3 = PS.INTLEVEL + moveqz a3, a2, a0 # a3 = LOCKLEVEL iff interrupt + movi a2, 1 << PS_WOE_BIT + or a3, a3, a2 + rsr a0, exccause + xsr a3, ps + + s32i a3, a1, PT_PS # save ps + + /* Save lbeg, lend */ + + rsr a2, lbeg + rsr a3, lend + s32i a2, a1, PT_LBEG + s32i a3, a1, PT_LEND + + /* Save SCOMPARE1 */ + +#if XCHAL_HAVE_S32C1I + rsr a2, scompare1 + s32i a2, a1, PT_SCOMPARE1 +#endif + + /* Save optional registers. */ + + save_xtregs_opt a1 a2 a4 a5 a6 a7 PT_XTREGS_OPT + +#ifdef CONFIG_TRACE_IRQFLAGS + l32i a4, a1, PT_DEPC + /* Double exception means we came here with an exception + * while PS.EXCM was set, i.e. interrupts disabled. + */ + bgeui a4, VALID_DOUBLE_EXCEPTION_ADDRESS, 1f + l32i a4, a1, PT_EXCCAUSE + bnei a4, EXCCAUSE_LEVEL1_INTERRUPT, 1f + /* We came here with an interrupt means interrupts were enabled + * and we've just disabled them. + */ + movi a4, trace_hardirqs_off + callx4 a4 +1: +#endif + + /* Go to second-level dispatcher. Set up parameters to pass to the + * exception handler and call the exception handler. + */ + + rsr a4, excsave1 + mov a6, a1 # pass stack frame + mov a7, a0 # pass EXCCAUSE + addx4 a4, a0, a4 + l32i a4, a4, EXC_TABLE_DEFAULT # load handler + + /* Call the second-level handler */ + + callx4 a4 + + /* Jump here for exception exit */ + .global common_exception_return +common_exception_return: + +1: + rsil a2, LOCKLEVEL + + /* Jump if we are returning from kernel exceptions. */ + + l32i a3, a1, PT_PS + GET_THREAD_INFO(a2, a1) + l32i a4, a2, TI_FLAGS + _bbci.l a3, PS_UM_BIT, 6f + + /* Specific to a user exception exit: + * We need to check some flags for signal handling and rescheduling, + * and have to restore WB and WS, extra states, and all registers + * in the register file that were in use in the user task. + * Note that we don't disable interrupts here. + */ + + _bbsi.l a4, TIF_NEED_RESCHED, 3f + _bbsi.l a4, TIF_NOTIFY_RESUME, 2f + _bbci.l a4, TIF_SIGPENDING, 5f + +2: l32i a4, a1, PT_DEPC + bgeui a4, VALID_DOUBLE_EXCEPTION_ADDRESS, 4f + + /* Call do_signal() */ + + rsil a2, 0 + movi a4, do_notify_resume # int do_notify_resume(struct pt_regs*) + mov a6, a1 + callx4 a4 + j 1b + +3: /* Reschedule */ + + rsil a2, 0 + movi a4, schedule # void schedule (void) + callx4 a4 + j 1b + +#ifdef CONFIG_PREEMPT +6: + _bbci.l a4, TIF_NEED_RESCHED, 4f + + /* Check current_thread_info->preempt_count */ + + l32i a4, a2, TI_PRE_COUNT + bnez a4, 4f + movi a4, preempt_schedule_irq + callx4 a4 + j 1b +#endif + +5: +#ifdef CONFIG_DEBUG_TLB_SANITY + l32i a4, a1, PT_DEPC + bgeui a4, VALID_DOUBLE_EXCEPTION_ADDRESS, 4f + movi a4, check_tlb_sanity + callx4 a4 +#endif +6: +4: +#ifdef CONFIG_TRACE_IRQFLAGS + l32i a4, a1, PT_DEPC + /* Double exception means we came here with an exception + * while PS.EXCM was set, i.e. interrupts disabled. + */ + bgeui a4, VALID_DOUBLE_EXCEPTION_ADDRESS, 1f + l32i a4, a1, PT_EXCCAUSE + bnei a4, EXCCAUSE_LEVEL1_INTERRUPT, 1f + /* We came here with an interrupt means interrupts were enabled + * and we'll reenable them on return. + */ + movi a4, trace_hardirqs_on + callx4 a4 +1: +#endif + /* Restore optional registers. */ + + load_xtregs_opt a1 a2 a4 a5 a6 a7 PT_XTREGS_OPT + + /* Restore SCOMPARE1 */ + +#if XCHAL_HAVE_S32C1I + l32i a2, a1, PT_SCOMPARE1 + wsr a2, scompare1 +#endif + wsr a3, ps /* disable interrupts */ + + _bbci.l a3, PS_UM_BIT, kernel_exception_exit + +user_exception_exit: + + /* Restore the state of the task and return from the exception. */ + + /* Switch to the user thread WINDOWBASE. Save SP temporarily in DEPC */ + + l32i a2, a1, PT_WINDOWBASE + l32i a3, a1, PT_WINDOWSTART + wsr a1, depc # use DEPC as temp storage + wsr a3, windowstart # restore WINDOWSTART + ssr a2 # preserve user's WB in the SAR + wsr a2, windowbase # switch to user's saved WB + rsync + rsr a1, depc # restore stack pointer + l32i a2, a1, PT_WMASK # register frames saved (in bits 4...9) + rotw -1 # we restore a4..a7 + _bltui a6, 16, 1f # only have to restore current window? + + /* The working registers are a0 and a3. We are restoring to + * a4..a7. Be careful not to destroy what we have just restored. + * Note: wmask has the format YYYYM: + * Y: number of registers saved in groups of 4 + * M: 4 bit mask of first 16 registers + */ + + mov a2, a6 + mov a3, a5 + +2: rotw -1 # a0..a3 become a4..a7 + addi a3, a7, -4*4 # next iteration + addi a2, a6, -16 # decrementing Y in WMASK + l32i a4, a3, PT_AREG_END + 0 + l32i a5, a3, PT_AREG_END + 4 + l32i a6, a3, PT_AREG_END + 8 + l32i a7, a3, PT_AREG_END + 12 + _bgeui a2, 16, 2b + + /* Clear unrestored registers (don't leak anything to user-land */ + +1: rsr a0, windowbase + rsr a3, sar + sub a3, a0, a3 + beqz a3, 2f + extui a3, a3, 0, WBBITS + +1: rotw -1 + addi a3, a7, -1 + movi a4, 0 + movi a5, 0 + movi a6, 0 + movi a7, 0 + bgei a3, 1, 1b + + /* We are back were we were when we started. + * Note: a2 still contains WMASK (if we've returned to the original + * frame where we had loaded a2), or at least the lower 4 bits + * (if we have restored WSBITS-1 frames). + */ + +#if XCHAL_HAVE_THREADPTR + l32i a3, a1, PT_THREADPTR + wur a3, threadptr +#endif + +2: j common_exception_exit + + /* This is the kernel exception exit. + * We avoided to do a MOVSP when we entered the exception, but we + * have to do it here. + */ + +kernel_exception_exit: + + /* Check if we have to do a movsp. + * + * We only have to do a movsp if the previous window-frame has + * been spilled to the *temporary* exception stack instead of the + * task's stack. This is the case if the corresponding bit in + * WINDOWSTART for the previous window-frame was set before + * (not spilled) but is zero now (spilled). + * If this bit is zero, all other bits except the one for the + * current window frame are also zero. So, we can use a simple test: + * 'and' WINDOWSTART and WINDOWSTART-1: + * + * (XXXXXX1[0]* - 1) AND XXXXXX1[0]* = XXXXXX0[0]* + * + * The result is zero only if one bit was set. + * + * (Note: We might have gone through several task switches before + * we come back to the current task, so WINDOWBASE might be + * different from the time the exception occurred.) + */ + + /* Test WINDOWSTART before and after the exception. + * We actually have WMASK, so we only have to test if it is 1 or not. + */ + + l32i a2, a1, PT_WMASK + _beqi a2, 1, common_exception_exit # Spilled before exception,jump + + /* Test WINDOWSTART now. If spilled, do the movsp */ + + rsr a3, windowstart + addi a0, a3, -1 + and a3, a3, a0 + _bnez a3, common_exception_exit + + /* Do a movsp (we returned from a call4, so we have at least a0..a7) */ + + addi a0, a1, -16 + l32i a3, a0, 0 + l32i a4, a0, 4 + s32i a3, a1, PT_SIZE+0 + s32i a4, a1, PT_SIZE+4 + l32i a3, a0, 8 + l32i a4, a0, 12 + s32i a3, a1, PT_SIZE+8 + s32i a4, a1, PT_SIZE+12 + + /* Common exception exit. + * We restore the special register and the current window frame, and + * return from the exception. + * + * Note: We expect a2 to hold PT_WMASK + */ + +common_exception_exit: + + /* Restore address registers. */ + + _bbsi.l a2, 1, 1f + l32i a4, a1, PT_AREG4 + l32i a5, a1, PT_AREG5 + l32i a6, a1, PT_AREG6 + l32i a7, a1, PT_AREG7 + _bbsi.l a2, 2, 1f + l32i a8, a1, PT_AREG8 + l32i a9, a1, PT_AREG9 + l32i a10, a1, PT_AREG10 + l32i a11, a1, PT_AREG11 + _bbsi.l a2, 3, 1f + l32i a12, a1, PT_AREG12 + l32i a13, a1, PT_AREG13 + l32i a14, a1, PT_AREG14 + l32i a15, a1, PT_AREG15 + + /* Restore PC, SAR */ + +1: l32i a2, a1, PT_PC + l32i a3, a1, PT_SAR + wsr a2, epc1 + wsr a3, sar + + /* Restore LBEG, LEND, LCOUNT */ + + l32i a2, a1, PT_LBEG + l32i a3, a1, PT_LEND + wsr a2, lbeg + l32i a2, a1, PT_LCOUNT + wsr a3, lend + wsr a2, lcount + + /* We control single stepping through the ICOUNTLEVEL register. */ + + l32i a2, a1, PT_ICOUNTLEVEL + movi a3, -2 + wsr a2, icountlevel + wsr a3, icount + + /* Check if it was double exception. */ + + l32i a0, a1, PT_DEPC + l32i a3, a1, PT_AREG3 + l32i a2, a1, PT_AREG2 + _bgeui a0, VALID_DOUBLE_EXCEPTION_ADDRESS, 1f + + /* Restore a0...a3 and return */ + + l32i a0, a1, PT_AREG0 + l32i a1, a1, PT_AREG1 + rfe + +1: wsr a0, depc + l32i a0, a1, PT_AREG0 + l32i a1, a1, PT_AREG1 + rfde + +ENDPROC(kernel_exception) + +/* + * Debug exception handler. + * + * Currently, we don't support KGDB, so only user application can be debugged. + * + * When we get here, a0 is trashed and saved to excsave[debuglevel] + */ + +ENTRY(debug_exception) + + rsr a0, SREG_EPS + XCHAL_DEBUGLEVEL + bbsi.l a0, PS_EXCM_BIT, 1f # exception mode + + /* Set EPC1 and EXCCAUSE */ + + wsr a2, depc # save a2 temporarily + rsr a2, SREG_EPC + XCHAL_DEBUGLEVEL + wsr a2, epc1 + + movi a2, EXCCAUSE_MAPPED_DEBUG + wsr a2, exccause + + /* Restore PS to the value before the debug exc but with PS.EXCM set.*/ + + movi a2, 1 << PS_EXCM_BIT + or a2, a0, a2 + movi a0, debug_exception # restore a3, debug jump vector + wsr a2, ps + xsr a0, SREG_EXCSAVE + XCHAL_DEBUGLEVEL + + /* Switch to kernel/user stack, restore jump vector, and save a0 */ + + bbsi.l a2, PS_UM_BIT, 2f # jump if user mode + + addi a2, a1, -16-PT_SIZE # assume kernel stack + s32i a0, a2, PT_AREG0 + movi a0, 0 + s32i a1, a2, PT_AREG1 + s32i a0, a2, PT_DEPC # mark it as a regular exception + xsr a0, depc + s32i a3, a2, PT_AREG3 + s32i a0, a2, PT_AREG2 + mov a1, a2 + j _kernel_exception + +2: rsr a2, excsave1 + l32i a2, a2, EXC_TABLE_KSTK # load kernel stack pointer + s32i a0, a2, PT_AREG0 + movi a0, 0 + s32i a1, a2, PT_AREG1 + s32i a0, a2, PT_DEPC + xsr a0, depc + s32i a3, a2, PT_AREG3 + s32i a0, a2, PT_AREG2 + mov a1, a2 + j _user_exception + + /* Debug exception while in exception mode. */ +1: j 1b // FIXME!! + +ENDPROC(debug_exception) + +/* + * We get here in case of an unrecoverable exception. + * The only thing we can do is to be nice and print a panic message. + * We only produce a single stack frame for panic, so ??? + * + * + * Entry conditions: + * + * - a0 contains the caller address; original value saved in excsave1. + * - the original a0 contains a valid return address (backtrace) or 0. + * - a2 contains a valid stackpointer + * + * Notes: + * + * - If the stack pointer could be invalid, the caller has to setup a + * dummy stack pointer (e.g. the stack of the init_task) + * + * - If the return address could be invalid, the caller has to set it + * to 0, so the backtrace would stop. + * + */ + .align 4 +unrecoverable_text: + .ascii "Unrecoverable error in exception handler\0" + +ENTRY(unrecoverable_exception) + + movi a0, 1 + movi a1, 0 + + wsr a0, windowstart + wsr a1, windowbase + rsync + + movi a1, (1 << PS_WOE_BIT) | LOCKLEVEL + wsr a1, ps + rsync + + movi a1, init_task + movi a0, 0 + addi a1, a1, PT_REGS_OFFSET + + movi a4, panic + movi a6, unrecoverable_text + + callx4 a4 + +1: j 1b + +ENDPROC(unrecoverable_exception) + +/* -------------------------- FAST EXCEPTION HANDLERS ----------------------- */ + +/* + * Fast-handler for alloca exceptions + * + * The ALLOCA handler is entered when user code executes the MOVSP + * instruction and the caller's frame is not in the register file. + * + * This algorithm was taken from the Ross Morley's RTOS Porting Layer: + * + * /home/ross/rtos/porting/XtensaRTOS-PortingLayer-20090507/xtensa_vectors.S + * + * It leverages the existing window spill/fill routines and their support for + * double exceptions. The 'movsp' instruction will only cause an exception if + * the next window needs to be loaded. In fact this ALLOCA exception may be + * replaced at some point by changing the hardware to do a underflow exception + * of the proper size instead. + * + * This algorithm simply backs out the register changes started by the user + * excpetion handler, makes it appear that we have started a window underflow + * by rotating the window back and then setting the old window base (OWB) in + * the 'ps' register with the rolled back window base. The 'movsp' instruction + * will be re-executed and this time since the next window frames is in the + * active AR registers it won't cause an exception. + * + * If the WindowUnderflow code gets a TLB miss the page will get mapped + * the the partial windeowUnderflow will be handeled in the double exception + * handler. + * + * Entry condition: + * + * a0: trashed, original value saved on stack (PT_AREG0) + * a1: a1 + * a2: new stack pointer, original in DEPC + * a3: a3 + * depc: a2, original value saved on stack (PT_DEPC) + * excsave_1: dispatch table + * + * PT_DEPC >= VALID_DOUBLE_EXCEPTION_ADDRESS: double exception, DEPC + * < VALID_DOUBLE_EXCEPTION_ADDRESS: regular exception + */ + +ENTRY(fast_alloca) + rsr a0, windowbase + rotw -1 + rsr a2, ps + extui a3, a2, PS_OWB_SHIFT, PS_OWB_WIDTH + xor a3, a3, a4 + l32i a4, a6, PT_AREG0 + l32i a1, a6, PT_DEPC + rsr a6, depc + wsr a1, depc + slli a3, a3, PS_OWB_SHIFT + xor a2, a2, a3 + wsr a2, ps + rsync + + _bbci.l a4, 31, 4f + rotw -1 + _bbci.l a8, 30, 8f + rotw -1 + j _WindowUnderflow12 +8: j _WindowUnderflow8 +4: j _WindowUnderflow4 +ENDPROC(fast_alloca) + +/* + * fast system calls. + * + * WARNING: The kernel doesn't save the entire user context before + * handling a fast system call. These functions are small and short, + * usually offering some functionality not available to user tasks. + * + * BE CAREFUL TO PRESERVE THE USER'S CONTEXT. + * + * Entry condition: + * + * a0: trashed, original value saved on stack (PT_AREG0) + * a1: a1 + * a2: new stack pointer, original in DEPC + * a3: a3 + * depc: a2, original value saved on stack (PT_DEPC) + * excsave_1: dispatch table + */ + +ENTRY(fast_syscall_kernel) + + /* Skip syscall. */ + + rsr a0, epc1 + addi a0, a0, 3 + wsr a0, epc1 + + l32i a0, a2, PT_DEPC + bgeui a0, VALID_DOUBLE_EXCEPTION_ADDRESS, fast_syscall_unrecoverable + + rsr a0, depc # get syscall-nr + _beqz a0, fast_syscall_spill_registers + _beqi a0, __NR_xtensa, fast_syscall_xtensa + + j kernel_exception + +ENDPROC(fast_syscall_kernel) + +ENTRY(fast_syscall_user) + + /* Skip syscall. */ + + rsr a0, epc1 + addi a0, a0, 3 + wsr a0, epc1 + + l32i a0, a2, PT_DEPC + bgeui a0, VALID_DOUBLE_EXCEPTION_ADDRESS, fast_syscall_unrecoverable + + rsr a0, depc # get syscall-nr + _beqz a0, fast_syscall_spill_registers + _beqi a0, __NR_xtensa, fast_syscall_xtensa + + j user_exception + +ENDPROC(fast_syscall_user) + +ENTRY(fast_syscall_unrecoverable) + + /* Restore all states. */ + + l32i a0, a2, PT_AREG0 # restore a0 + xsr a2, depc # restore a2, depc + + wsr a0, excsave1 + movi a0, unrecoverable_exception + callx0 a0 + +ENDPROC(fast_syscall_unrecoverable) + +/* + * sysxtensa syscall handler + * + * int sysxtensa (SYS_XTENSA_ATOMIC_SET, ptr, val, unused); + * int sysxtensa (SYS_XTENSA_ATOMIC_ADD, ptr, val, unused); + * int sysxtensa (SYS_XTENSA_ATOMIC_EXG_ADD, ptr, val, unused); + * int sysxtensa (SYS_XTENSA_ATOMIC_CMP_SWP, ptr, oldval, newval); + * a2 a6 a3 a4 a5 + * + * Entry condition: + * + * a0: a2 (syscall-nr), original value saved on stack (PT_AREG0) + * a1: a1 + * a2: new stack pointer, original in a0 and DEPC + * a3: a3 + * a4..a15: unchanged + * depc: a2, original value saved on stack (PT_DEPC) + * excsave_1: dispatch table + * + * PT_DEPC >= VALID_DOUBLE_EXCEPTION_ADDRESS: double exception, DEPC + * < VALID_DOUBLE_EXCEPTION_ADDRESS: regular exception + * + * Note: we don't have to save a2; a2 holds the return value + * + * We use the two macros TRY and CATCH: + * + * TRY adds an entry to the __ex_table fixup table for the immediately + * following instruction. + * + * CATCH catches any exception that occurred at one of the preceding TRY + * statements and continues from there + * + * Usage TRY l32i a0, a1, 0 + * <other code> + * done: rfe + * CATCH <set return code> + * j done + */ + +#ifdef CONFIG_FAST_SYSCALL_XTENSA + +#define TRY \ + .section __ex_table, "a"; \ + .word 66f, 67f; \ + .text; \ +66: + +#define CATCH \ +67: + +ENTRY(fast_syscall_xtensa) + + s32i a7, a2, PT_AREG7 # we need an additional register + movi a7, 4 # sizeof(unsigned int) + access_ok a3, a7, a0, a2, .Leac # a0: scratch reg, a2: sp + + _bgeui a6, SYS_XTENSA_COUNT, .Lill + _bnei a6, SYS_XTENSA_ATOMIC_CMP_SWP, .Lnswp + + /* Fall through for ATOMIC_CMP_SWP. */ + +.Lswp: /* Atomic compare and swap */ + +TRY l32i a0, a3, 0 # read old value + bne a0, a4, 1f # same as old value? jump +TRY s32i a5, a3, 0 # different, modify value + l32i a7, a2, PT_AREG7 # restore a7 + l32i a0, a2, PT_AREG0 # restore a0 + movi a2, 1 # and return 1 + rfe + +1: l32i a7, a2, PT_AREG7 # restore a7 + l32i a0, a2, PT_AREG0 # restore a0 + movi a2, 0 # return 0 (note that we cannot set + rfe + +.Lnswp: /* Atomic set, add, and exg_add. */ + +TRY l32i a7, a3, 0 # orig + addi a6, a6, -SYS_XTENSA_ATOMIC_SET + add a0, a4, a7 # + arg + moveqz a0, a4, a6 # set + addi a6, a6, SYS_XTENSA_ATOMIC_SET +TRY s32i a0, a3, 0 # write new value + + mov a0, a2 + mov a2, a7 + l32i a7, a0, PT_AREG7 # restore a7 + l32i a0, a0, PT_AREG0 # restore a0 + rfe + +CATCH +.Leac: l32i a7, a2, PT_AREG7 # restore a7 + l32i a0, a2, PT_AREG0 # restore a0 + movi a2, -EFAULT + rfe + +.Lill: l32i a7, a2, PT_AREG7 # restore a7 + l32i a0, a2, PT_AREG0 # restore a0 + movi a2, -EINVAL + rfe + +ENDPROC(fast_syscall_xtensa) + +#else /* CONFIG_FAST_SYSCALL_XTENSA */ + +ENTRY(fast_syscall_xtensa) + + l32i a0, a2, PT_AREG0 # restore a0 + movi a2, -ENOSYS + rfe + +ENDPROC(fast_syscall_xtensa) + +#endif /* CONFIG_FAST_SYSCALL_XTENSA */ + + +/* fast_syscall_spill_registers. + * + * Entry condition: + * + * a0: trashed, original value saved on stack (PT_AREG0) + * a1: a1 + * a2: new stack pointer, original in DEPC + * a3: a3 + * depc: a2, original value saved on stack (PT_DEPC) + * excsave_1: dispatch table + * + * Note: We assume the stack pointer is EXC_TABLE_KSTK in the fixup handler. + */ + +#ifdef CONFIG_FAST_SYSCALL_SPILL_REGISTERS + +ENTRY(fast_syscall_spill_registers) + + /* Register a FIXUP handler (pass current wb as a parameter) */ + + xsr a3, excsave1 + movi a0, fast_syscall_spill_registers_fixup + s32i a0, a3, EXC_TABLE_FIXUP + rsr a0, windowbase + s32i a0, a3, EXC_TABLE_PARAM + xsr a3, excsave1 # restore a3 and excsave_1 + + /* Save a3, a4 and SAR on stack. */ + + rsr a0, sar + s32i a3, a2, PT_AREG3 + s32i a0, a2, PT_SAR + + /* The spill routine might clobber a4, a7, a8, a11, a12, and a15. */ + + s32i a4, a2, PT_AREG4 + s32i a7, a2, PT_AREG7 + s32i a8, a2, PT_AREG8 + s32i a11, a2, PT_AREG11 + s32i a12, a2, PT_AREG12 + s32i a15, a2, PT_AREG15 + + /* + * Rotate ws so that the current windowbase is at bit 0. + * Assume ws = xxxwww1yy (www1 current window frame). + * Rotate ws right so that a4 = yyxxxwww1. + */ + + rsr a0, windowbase + rsr a3, windowstart # a3 = xxxwww1yy + ssr a0 # holds WB + slli a0, a3, WSBITS + or a3, a3, a0 # a3 = xxxwww1yyxxxwww1yy + srl a3, a3 # a3 = 00xxxwww1yyxxxwww1 + + /* We are done if there are no more than the current register frame. */ + + extui a3, a3, 1, WSBITS-1 # a3 = 0yyxxxwww + movi a0, (1 << (WSBITS-1)) + _beqz a3, .Lnospill # only one active frame? jump + + /* We want 1 at the top, so that we return to the current windowbase */ + + or a3, a3, a0 # 1yyxxxwww + + /* Skip empty frames - get 'oldest' WINDOWSTART-bit. */ + + wsr a3, windowstart # save shifted windowstart + neg a0, a3 + and a3, a0, a3 # first bit set from right: 000010000 + + ffs_ws a0, a3 # a0: shifts to skip empty frames + movi a3, WSBITS + sub a0, a3, a0 # WSBITS-a0:number of 0-bits from right + ssr a0 # save in SAR for later. + + rsr a3, windowbase + add a3, a3, a0 + wsr a3, windowbase + rsync + + rsr a3, windowstart + srl a3, a3 # shift windowstart + + /* WB is now just one frame below the oldest frame in the register + window. WS is shifted so the oldest frame is in bit 0, thus, WB + and WS differ by one 4-register frame. */ + + /* Save frames. Depending what call was used (call4, call8, call12), + * we have to save 4,8. or 12 registers. + */ + + +.Lloop: _bbsi.l a3, 1, .Lc4 + _bbci.l a3, 2, .Lc12 + +.Lc8: s32e a4, a13, -16 + l32e a4, a5, -12 + s32e a8, a4, -32 + s32e a5, a13, -12 + s32e a6, a13, -8 + s32e a7, a13, -4 + s32e a9, a4, -28 + s32e a10, a4, -24 + s32e a11, a4, -20 + srli a11, a3, 2 # shift windowbase by 2 + rotw 2 + _bnei a3, 1, .Lloop + j .Lexit + +.Lc4: s32e a4, a9, -16 + s32e a5, a9, -12 + s32e a6, a9, -8 + s32e a7, a9, -4 + + srli a7, a3, 1 + rotw 1 + _bnei a3, 1, .Lloop + j .Lexit + +.Lc12: _bbci.l a3, 3, .Linvalid_mask # bit 2 shouldn't be zero! + + /* 12-register frame (call12) */ + + l32e a0, a5, -12 + s32e a8, a0, -48 + mov a8, a0 + + s32e a9, a8, -44 + s32e a10, a8, -40 + s32e a11, a8, -36 + s32e a12, a8, -32 + s32e a13, a8, -28 + s32e a14, a8, -24 + s32e a15, a8, -20 + srli a15, a3, 3 + + /* The stack pointer for a4..a7 is out of reach, so we rotate the + * window, grab the stackpointer, and rotate back. + * Alternatively, we could also use the following approach, but that + * makes the fixup routine much more complicated: + * rotw 1 + * s32e a0, a13, -16 + * ... + * rotw 2 + */ + + rotw 1 + mov a4, a13 + rotw -1 + + s32e a4, a8, -16 + s32e a5, a8, -12 + s32e a6, a8, -8 + s32e a7, a8, -4 + + rotw 3 + + _beqi a3, 1, .Lexit + j .Lloop + +.Lexit: + + /* Done. Do the final rotation and set WS */ + + rotw 1 + rsr a3, windowbase + ssl a3 + movi a3, 1 + sll a3, a3 + wsr a3, windowstart +.Lnospill: + + /* Advance PC, restore registers and SAR, and return from exception. */ + + l32i a3, a2, PT_SAR + l32i a0, a2, PT_AREG0 + wsr a3, sar + l32i a3, a2, PT_AREG3 + + /* Restore clobbered registers. */ + + l32i a4, a2, PT_AREG4 + l32i a7, a2, PT_AREG7 + l32i a8, a2, PT_AREG8 + l32i a11, a2, PT_AREG11 + l32i a12, a2, PT_AREG12 + l32i a15, a2, PT_AREG15 + + movi a2, 0 + rfe + +.Linvalid_mask: + + /* We get here because of an unrecoverable error in the window + * registers, so set up a dummy frame and kill the user application. + * Note: We assume EXC_TABLE_KSTK contains a valid stack pointer. + */ + + movi a0, 1 + movi a1, 0 + + wsr a0, windowstart + wsr a1, windowbase + rsync + + movi a0, 0 + + rsr a3, excsave1 + l32i a1, a3, EXC_TABLE_KSTK + + movi a4, (1 << PS_WOE_BIT) | LOCKLEVEL + wsr a4, ps + rsync + + movi a6, SIGSEGV + movi a4, do_exit + callx4 a4 + + /* shouldn't return, so panic */ + + wsr a0, excsave1 + movi a0, unrecoverable_exception + callx0 a0 # should not return +1: j 1b + + +ENDPROC(fast_syscall_spill_registers) + +/* Fixup handler. + * + * We get here if the spill routine causes an exception, e.g. tlb miss. + * We basically restore WINDOWBASE and WINDOWSTART to the condition when + * we entered the spill routine and jump to the user exception handler. + * + * Note that we only need to restore the bits in windowstart that have not + * been spilled yet by the _spill_register routine. Luckily, a3 contains a + * rotated windowstart with only those bits set for frames that haven't been + * spilled yet. Because a3 is rotated such that bit 0 represents the register + * frame for the current windowbase - 1, we need to rotate a3 left by the + * value of the current windowbase + 1 and move it to windowstart. + * + * a0: value of depc, original value in depc + * a2: trashed, original value in EXC_TABLE_DOUBLE_SAVE + * a3: exctable, original value in excsave1 + */ + +ENTRY(fast_syscall_spill_registers_fixup) + + rsr a2, windowbase # get current windowbase (a2 is saved) + xsr a0, depc # restore depc and a0 + ssl a2 # set shift (32 - WB) + + /* We need to make sure the current registers (a0-a3) are preserved. + * To do this, we simply set the bit for the current window frame + * in WS, so that the exception handlers save them to the task stack. + * + * Note: we use a3 to set the windowbase, so we take a special care + * of it, saving it in the original _spill_registers frame across + * the exception handler call. + */ + + xsr a3, excsave1 # get spill-mask + slli a3, a3, 1 # shift left by one + addi a3, a3, 1 # set the bit for the current window frame + + slli a2, a3, 32-WSBITS + src a2, a3, a2 # a2 = xxwww1yyxxxwww1yy...... + wsr a2, windowstart # set corrected windowstart + + srli a3, a3, 1 + rsr a2, excsave1 + l32i a2, a2, EXC_TABLE_DOUBLE_SAVE # restore a2 + xsr a2, excsave1 + s32i a3, a2, EXC_TABLE_DOUBLE_SAVE # save a3 + l32i a3, a2, EXC_TABLE_PARAM # original WB (in user task) + xsr a2, excsave1 + + /* Return to the original (user task) WINDOWBASE. + * We leave the following frame behind: + * a0, a1, a2 same + * a3: trashed (saved in EXC_TABLE_DOUBLE_SAVE) + * depc: depc (we have to return to that address) + * excsave_1: exctable + */ + + wsr a3, windowbase + rsync + + /* We are now in the original frame when we entered _spill_registers: + * a0: return address + * a1: used, stack pointer + * a2: kernel stack pointer + * a3: available + * depc: exception address + * excsave: exctable + * Note: This frame might be the same as above. + */ + + /* Setup stack pointer. */ + + addi a2, a2, -PT_USER_SIZE + s32i a0, a2, PT_AREG0 + + /* Make sure we return to this fixup handler. */ + + movi a3, fast_syscall_spill_registers_fixup_return + s32i a3, a2, PT_DEPC # setup depc + + /* Jump to the exception handler. */ + + rsr a3, excsave1 + rsr a0, exccause + addx4 a0, a0, a3 # find entry in table + l32i a0, a0, EXC_TABLE_FAST_USER # load handler + l32i a3, a3, EXC_TABLE_DOUBLE_SAVE + jx a0 + +ENDPROC(fast_syscall_spill_registers_fixup) + +ENTRY(fast_syscall_spill_registers_fixup_return) + + /* When we return here, all registers have been restored (a2: DEPC) */ + + wsr a2, depc # exception address + + /* Restore fixup handler. */ + + rsr a2, excsave1 + s32i a3, a2, EXC_TABLE_DOUBLE_SAVE + movi a3, fast_syscall_spill_registers_fixup + s32i a3, a2, EXC_TABLE_FIXUP + rsr a3, windowbase + s32i a3, a2, EXC_TABLE_PARAM + l32i a2, a2, EXC_TABLE_KSTK + + /* Load WB at the time the exception occurred. */ + + rsr a3, sar # WB is still in SAR + neg a3, a3 + wsr a3, windowbase + rsync + + rsr a3, excsave1 + l32i a3, a3, EXC_TABLE_DOUBLE_SAVE + + rfde + +ENDPROC(fast_syscall_spill_registers_fixup_return) + +#else /* CONFIG_FAST_SYSCALL_SPILL_REGISTERS */ + +ENTRY(fast_syscall_spill_registers) + + l32i a0, a2, PT_AREG0 # restore a0 + movi a2, -ENOSYS + rfe + +ENDPROC(fast_syscall_spill_registers) + +#endif /* CONFIG_FAST_SYSCALL_SPILL_REGISTERS */ + +#ifdef CONFIG_MMU +/* + * We should never get here. Bail out! + */ + +ENTRY(fast_second_level_miss_double_kernel) + +1: movi a0, unrecoverable_exception + callx0 a0 # should not return +1: j 1b + +ENDPROC(fast_second_level_miss_double_kernel) + +/* First-level entry handler for user, kernel, and double 2nd-level + * TLB miss exceptions. Note that for now, user and kernel miss + * exceptions share the same entry point and are handled identically. + * + * An old, less-efficient C version of this function used to exist. + * We include it below, interleaved as comments, for reference. + * + * Entry condition: + * + * a0: trashed, original value saved on stack (PT_AREG0) + * a1: a1 + * a2: new stack pointer, original in DEPC + * a3: a3 + * depc: a2, original value saved on stack (PT_DEPC) + * excsave_1: dispatch table + * + * PT_DEPC >= VALID_DOUBLE_EXCEPTION_ADDRESS: double exception, DEPC + * < VALID_DOUBLE_EXCEPTION_ADDRESS: regular exception + */ + +ENTRY(fast_second_level_miss) + + /* Save a1 and a3. Note: we don't expect a double exception. */ + + s32i a1, a2, PT_AREG1 + s32i a3, a2, PT_AREG3 + + /* We need to map the page of PTEs for the user task. Find + * the pointer to that page. Also, it's possible for tsk->mm + * to be NULL while tsk->active_mm is nonzero if we faulted on + * a vmalloc address. In that rare case, we must use + * active_mm instead to avoid a fault in this handler. See + * + * http://mail.nl.linux.org/linux-mm/2002-08/msg00258.html + * (or search Internet on "mm vs. active_mm") + * + * if (!mm) + * mm = tsk->active_mm; + * pgd = pgd_offset (mm, regs->excvaddr); + * pmd = pmd_offset (pgd, regs->excvaddr); + * pmdval = *pmd; + */ + + GET_CURRENT(a1,a2) + l32i a0, a1, TASK_MM # tsk->mm + beqz a0, 9f + +8: rsr a3, excvaddr # fault address + _PGD_OFFSET(a0, a3, a1) + l32i a0, a0, 0 # read pmdval + beqz a0, 2f + + /* Read ptevaddr and convert to top of page-table page. + * + * vpnval = read_ptevaddr_register() & PAGE_MASK; + * vpnval += DTLB_WAY_PGTABLE; + * pteval = mk_pte (virt_to_page(pmd_val(pmdval)), PAGE_KERNEL); + * write_dtlb_entry (pteval, vpnval); + * + * The messy computation for 'pteval' above really simplifies + * into the following: + * + * pteval = ((pmdval - PAGE_OFFSET) & PAGE_MASK) | PAGE_DIRECTORY + */ + + movi a1, (-PAGE_OFFSET) & 0xffffffff + add a0, a0, a1 # pmdval - PAGE_OFFSET + extui a1, a0, 0, PAGE_SHIFT # ... & PAGE_MASK + xor a0, a0, a1 + + movi a1, _PAGE_DIRECTORY + or a0, a0, a1 # ... | PAGE_DIRECTORY + + /* + * We utilize all three wired-ways (7-9) to hold pmd translations. + * Memory regions are mapped to the DTLBs according to bits 28 and 29. + * This allows to map the three most common regions to three different + * DTLBs: + * 0,1 -> way 7 program (0040.0000) and virtual (c000.0000) + * 2 -> way 8 shared libaries (2000.0000) + * 3 -> way 0 stack (3000.0000) + */ + + extui a3, a3, 28, 2 # addr. bit 28 and 29 0,1,2,3 + rsr a1, ptevaddr + addx2 a3, a3, a3 # -> 0,3,6,9 + srli a1, a1, PAGE_SHIFT + extui a3, a3, 2, 2 # -> 0,0,1,2 + slli a1, a1, PAGE_SHIFT # ptevaddr & PAGE_MASK + addi a3, a3, DTLB_WAY_PGD + add a1, a1, a3 # ... + way_number + +3: wdtlb a0, a1 + dsync + + /* Exit critical section. */ + +4: rsr a3, excsave1 + movi a0, 0 + s32i a0, a3, EXC_TABLE_FIXUP + + /* Restore the working registers, and return. */ + + l32i a0, a2, PT_AREG0 + l32i a1, a2, PT_AREG1 + l32i a3, a2, PT_AREG3 + l32i a2, a2, PT_DEPC + + bgeui a2, VALID_DOUBLE_EXCEPTION_ADDRESS, 1f + + /* Restore excsave1 and return. */ + + rsr a2, depc + rfe + + /* Return from double exception. */ + +1: xsr a2, depc + esync + rfde + +9: l32i a0, a1, TASK_ACTIVE_MM # unlikely case mm == 0 + j 8b + +#if (DCACHE_WAY_SIZE > PAGE_SIZE) + +2: /* Special case for cache aliasing. + * We (should) only get here if a clear_user_page, copy_user_page + * or the aliased cache flush functions got preemptively interrupted + * by another task. Re-establish temporary mapping to the + * TLBTEMP_BASE areas. + */ + + /* We shouldn't be in a double exception */ + + l32i a0, a2, PT_DEPC + bgeui a0, VALID_DOUBLE_EXCEPTION_ADDRESS, 2f + + /* Make sure the exception originated in the special functions */ + + movi a0, __tlbtemp_mapping_start + rsr a3, epc1 + bltu a3, a0, 2f + movi a0, __tlbtemp_mapping_end + bgeu a3, a0, 2f + + /* Check if excvaddr was in one of the TLBTEMP_BASE areas. */ + + movi a3, TLBTEMP_BASE_1 + rsr a0, excvaddr + bltu a0, a3, 2f + + addi a1, a0, -TLBTEMP_SIZE + bgeu a1, a3, 2f + + /* Check if we have to restore an ITLB mapping. */ + + movi a1, __tlbtemp_mapping_itlb + rsr a3, epc1 + sub a3, a3, a1 + + /* Calculate VPN */ + + movi a1, PAGE_MASK + and a1, a1, a0 + + /* Jump for ITLB entry */ + + bgez a3, 1f + + /* We can use up to two TLBTEMP areas, one for src and one for dst. */ + + extui a3, a0, PAGE_SHIFT + DCACHE_ALIAS_ORDER, 1 + add a1, a3, a1 + + /* PPN is in a6 for the first TLBTEMP area and in a7 for the second. */ + + mov a0, a6 + movnez a0, a7, a3 + j 3b + + /* ITLB entry. We only use dst in a6. */ + +1: witlb a6, a1 + isync + j 4b + + +#endif // DCACHE_WAY_SIZE > PAGE_SIZE + + +2: /* Invalid PGD, default exception handling */ + + rsr a1, depc + s32i a1, a2, PT_AREG2 + mov a1, a2 + + rsr a2, ps + bbsi.l a2, PS_UM_BIT, 1f + j _kernel_exception +1: j _user_exception + +ENDPROC(fast_second_level_miss) + +/* + * StoreProhibitedException + * + * Update the pte and invalidate the itlb mapping for this pte. + * + * Entry condition: + * + * a0: trashed, original value saved on stack (PT_AREG0) + * a1: a1 + * a2: new stack pointer, original in DEPC + * a3: a3 + * depc: a2, original value saved on stack (PT_DEPC) + * excsave_1: dispatch table + * + * PT_DEPC >= VALID_DOUBLE_EXCEPTION_ADDRESS: double exception, DEPC + * < VALID_DOUBLE_EXCEPTION_ADDRESS: regular exception + */ + +ENTRY(fast_store_prohibited) + + /* Save a1 and a3. */ + + s32i a1, a2, PT_AREG1 + s32i a3, a2, PT_AREG3 + + GET_CURRENT(a1,a2) + l32i a0, a1, TASK_MM # tsk->mm + beqz a0, 9f + +8: rsr a1, excvaddr # fault address + _PGD_OFFSET(a0, a1, a3) + l32i a0, a0, 0 + beqz a0, 2f + + /* + * Note that we test _PAGE_WRITABLE_BIT only if PTE is present + * and is not PAGE_NONE. See pgtable.h for possible PTE layouts. + */ + + _PTE_OFFSET(a0, a1, a3) + l32i a3, a0, 0 # read pteval + movi a1, _PAGE_CA_INVALID + ball a3, a1, 2f + bbci.l a3, _PAGE_WRITABLE_BIT, 2f + + movi a1, _PAGE_ACCESSED | _PAGE_DIRTY | _PAGE_HW_WRITE + or a3, a3, a1 + rsr a1, excvaddr + s32i a3, a0, 0 + + /* We need to flush the cache if we have page coloring. */ +#if (DCACHE_WAY_SIZE > PAGE_SIZE) && XCHAL_DCACHE_IS_WRITEBACK + dhwb a0, 0 +#endif + pdtlb a0, a1 + wdtlb a3, a0 + + /* Exit critical section. */ + + movi a0, 0 + rsr a3, excsave1 + s32i a0, a3, EXC_TABLE_FIXUP + + /* Restore the working registers, and return. */ + + l32i a3, a2, PT_AREG3 + l32i a1, a2, PT_AREG1 + l32i a0, a2, PT_AREG0 + l32i a2, a2, PT_DEPC + + bgeui a2, VALID_DOUBLE_EXCEPTION_ADDRESS, 1f + + rsr a2, depc + rfe + + /* Double exception. Restore FIXUP handler and return. */ + +1: xsr a2, depc + esync + rfde + +9: l32i a0, a1, TASK_ACTIVE_MM # unlikely case mm == 0 + j 8b + +2: /* If there was a problem, handle fault in C */ + + rsr a3, depc # still holds a2 + s32i a3, a2, PT_AREG2 + mov a1, a2 + + rsr a2, ps + bbsi.l a2, PS_UM_BIT, 1f + j _kernel_exception +1: j _user_exception + +ENDPROC(fast_store_prohibited) + +#endif /* CONFIG_MMU */ + +/* + * System Calls. + * + * void system_call (struct pt_regs* regs, int exccause) + * a2 a3 + */ + +ENTRY(system_call) + + entry a1, 32 + + /* regs->syscall = regs->areg[2] */ + + l32i a3, a2, PT_AREG2 + mov a6, a2 + movi a4, do_syscall_trace_enter + s32i a3, a2, PT_SYSCALL + callx4 a4 + + /* syscall = sys_call_table[syscall_nr] */ + + movi a4, sys_call_table; + movi a5, __NR_syscall_count + movi a6, -ENOSYS + bgeu a3, a5, 1f + + addx4 a4, a3, a4 + l32i a4, a4, 0 + movi a5, sys_ni_syscall; + beq a4, a5, 1f + + /* Load args: arg0 - arg5 are passed via regs. */ + + l32i a6, a2, PT_AREG6 + l32i a7, a2, PT_AREG3 + l32i a8, a2, PT_AREG4 + l32i a9, a2, PT_AREG5 + l32i a10, a2, PT_AREG8 + l32i a11, a2, PT_AREG9 + + /* Pass one additional argument to the syscall: pt_regs (on stack) */ + s32i a2, a1, 0 + + callx4 a4 + +1: /* regs->areg[2] = return_value */ + + s32i a6, a2, PT_AREG2 + movi a4, do_syscall_trace_leave + mov a6, a2 + callx4 a4 + retw + +ENDPROC(system_call) + +/* + * Spill live registers on the kernel stack macro. + * + * Entry condition: ps.woe is set, ps.excm is cleared + * Exit condition: windowstart has single bit set + * May clobber: a12, a13 + */ + .macro spill_registers_kernel + +#if XCHAL_NUM_AREGS > 16 + call12 1f + _j 2f + retw + .align 4 +1: + _entry a1, 48 + addi a12, a0, 3 +#if XCHAL_NUM_AREGS > 32 + .rept (XCHAL_NUM_AREGS - 32) / 12 + _entry a1, 48 + mov a12, a0 + .endr +#endif + _entry a1, 48 +#if XCHAL_NUM_AREGS % 12 == 0 + mov a8, a8 +#elif XCHAL_NUM_AREGS % 12 == 4 + mov a12, a12 +#elif XCHAL_NUM_AREGS % 12 == 8 + mov a4, a4 +#endif + retw +2: +#else + mov a12, a12 +#endif + .endm + +/* + * Task switch. + * + * struct task* _switch_to (struct task* prev, struct task* next) + * a2 a2 a3 + */ + +ENTRY(_switch_to) + + entry a1, 16 + + mov a11, a3 # and 'next' (a3) + + l32i a4, a2, TASK_THREAD_INFO + l32i a5, a3, TASK_THREAD_INFO + + save_xtregs_user a4 a6 a8 a9 a12 a13 THREAD_XTREGS_USER + +#if THREAD_RA > 1020 || THREAD_SP > 1020 + addi a10, a2, TASK_THREAD + s32i a0, a10, THREAD_RA - TASK_THREAD # save return address + s32i a1, a10, THREAD_SP - TASK_THREAD # save stack pointer +#else + s32i a0, a2, THREAD_RA # save return address + s32i a1, a2, THREAD_SP # save stack pointer +#endif + + /* Disable ints while we manipulate the stack pointer. */ + + rsil a14, LOCKLEVEL + rsr a3, excsave1 + rsync + s32i a3, a3, EXC_TABLE_FIXUP /* enter critical section */ + + /* Switch CPENABLE */ + +#if (XTENSA_HAVE_COPROCESSORS || XTENSA_HAVE_IO_PORTS) + l32i a3, a5, THREAD_CPENABLE + xsr a3, cpenable + s32i a3, a4, THREAD_CPENABLE +#endif + + /* Flush register file. */ + + spill_registers_kernel + + /* Set kernel stack (and leave critical section) + * Note: It's save to set it here. The stack will not be overwritten + * because the kernel stack will only be loaded again after + * we return from kernel space. + */ + + rsr a3, excsave1 # exc_table + movi a6, 0 + addi a7, a5, PT_REGS_OFFSET + s32i a6, a3, EXC_TABLE_FIXUP + s32i a7, a3, EXC_TABLE_KSTK + + /* restore context of the task 'next' */ + + l32i a0, a11, THREAD_RA # restore return address + l32i a1, a11, THREAD_SP # restore stack pointer + + load_xtregs_user a5 a6 a8 a9 a12 a13 THREAD_XTREGS_USER + + wsr a14, ps + rsync + + retw + +ENDPROC(_switch_to) + +ENTRY(ret_from_fork) + + /* void schedule_tail (struct task_struct *prev) + * Note: prev is still in a6 (return value from fake call4 frame) + */ + movi a4, schedule_tail + callx4 a4 + + movi a4, do_syscall_trace_leave + mov a6, a1 + callx4 a4 + + j common_exception_return + +ENDPROC(ret_from_fork) + +/* + * Kernel thread creation helper + * On entry, set up by copy_thread: a2 = thread_fn, a3 = thread_fn arg + * left from _switch_to: a6 = prev + */ +ENTRY(ret_from_kernel_thread) + + call4 schedule_tail + mov a6, a3 + callx4 a2 + j common_exception_return + +ENDPROC(ret_from_kernel_thread) diff --git a/arch/xtensa/kernel/head.S b/arch/xtensa/kernel/head.S new file mode 100644 index 000000000..15a461e2a --- /dev/null +++ b/arch/xtensa/kernel/head.S @@ -0,0 +1,380 @@ +/* + * arch/xtensa/kernel/head.S + * + * Xtensa Processor startup code. + * + * This file is subject to the terms and conditions of the GNU General Public + * License. See the file "COPYING" in the main directory of this archive + * for more details. + * + * Copyright (C) 2001 - 2008 Tensilica Inc. + * + * Chris Zankel <chris@zankel.net> + * Marc Gauthier <marc@tensilica.com, marc@alumni.uwaterloo.ca> + * Joe Taylor <joe@tensilica.com, joetylr@yahoo.com> + * Kevin Chea + */ + +#include <asm/processor.h> +#include <asm/page.h> +#include <asm/cacheasm.h> +#include <asm/initialize_mmu.h> +#include <asm/mxregs.h> + +#include <linux/init.h> +#include <linux/linkage.h> + +/* + * This module contains the entry code for kernel images. It performs the + * minimal setup needed to call the generic C routines. + * + * Prerequisites: + * + * - The kernel image has been loaded to the actual address where it was + * compiled to. + * - a2 contains either 0 or a pointer to a list of boot parameters. + * (see setup.c for more details) + * + */ + +/* + * _start + * + * The bootloader passes a pointer to a list of boot parameters in a2. + */ + + /* The first bytes of the kernel image must be an instruction, so we + * manually allocate and define the literal constant we need for a jx + * instruction. + */ + + __HEAD + .begin no-absolute-literals + +ENTRY(_start) + + /* Preserve the pointer to the boot parameter list in EXCSAVE_1 */ + wsr a2, excsave1 + _j _SetupOCD + + .align 4 + .literal_position +.Lstartup: + .word _startup + + .align 4 +_SetupOCD: + /* + * Initialize WB, WS, and clear PS.EXCM (to allow loop instructions). + * Set Interrupt Level just below XCHAL_DEBUGLEVEL to allow + * xt-gdb to single step via DEBUG exceptions received directly + * by ocd. + */ + movi a1, 1 + movi a0, 0 + wsr a1, windowstart + wsr a0, windowbase + rsync + + movi a1, LOCKLEVEL + wsr a1, ps + rsync + + .global _SetupMMU +_SetupMMU: + Offset = _SetupMMU - _start + +#ifdef CONFIG_INITIALIZE_XTENSA_MMU_INSIDE_VMLINUX + initialize_mmu +#if defined(CONFIG_MMU) && XCHAL_HAVE_PTP_MMU && XCHAL_HAVE_SPANNING_WAY + rsr a2, excsave1 + movi a3, 0x08000000 + bgeu a2, a3, 1f + movi a3, 0xd0000000 + add a2, a2, a3 + wsr a2, excsave1 +1: +#endif +#endif + .end no-absolute-literals + + l32r a0, .Lstartup + jx a0 + +ENDPROC(_start) + + __REF + .literal_position + +ENTRY(_startup) + + /* Set a0 to 0 for the remaining initialization. */ + + movi a0, 0 + +#if XCHAL_HAVE_VECBASE + movi a2, VECBASE_RESET_VADDR + wsr a2, vecbase +#endif + + /* Clear debugging registers. */ + +#if XCHAL_HAVE_DEBUG +#if XCHAL_NUM_IBREAK > 0 + wsr a0, ibreakenable +#endif + wsr a0, icount + movi a1, 15 + wsr a0, icountlevel + + .set _index, 0 + .rept XCHAL_NUM_DBREAK - 1 + wsr a0, SREG_DBREAKC + _index + .set _index, _index + 1 + .endr +#endif + + /* Clear CCOUNT (not really necessary, but nice) */ + + wsr a0, ccount # not really necessary, but nice + + /* Disable zero-loops. */ + +#if XCHAL_HAVE_LOOPS + wsr a0, lcount +#endif + + /* Disable all timers. */ + + .set _index, 0 + .rept XCHAL_NUM_TIMERS + wsr a0, SREG_CCOMPARE + _index + .set _index, _index + 1 + .endr + + /* Interrupt initialization. */ + + movi a2, XCHAL_INTTYPE_MASK_SOFTWARE | XCHAL_INTTYPE_MASK_EXTERN_EDGE + wsr a0, intenable + wsr a2, intclear + + /* Disable coprocessors. */ + +#if XCHAL_HAVE_CP + wsr a0, cpenable +#endif + + /* Initialize the caches. + * a2, a3 are just working registers (clobbered). + */ + +#if XCHAL_DCACHE_LINE_LOCKABLE + ___unlock_dcache_all a2 a3 +#endif + +#if XCHAL_ICACHE_LINE_LOCKABLE + ___unlock_icache_all a2 a3 +#endif + + ___invalidate_dcache_all a2 a3 + ___invalidate_icache_all a2 a3 + + isync + +#ifdef CONFIG_HAVE_SMP + movi a2, CCON # MX External Register to Configure Cache + movi a3, 1 + wer a3, a2 +#endif + + /* Setup stack and enable window exceptions (keep irqs disabled) */ + + movi a1, start_info + l32i a1, a1, 0 + + movi a2, (1 << PS_WOE_BIT) | LOCKLEVEL + # WOE=1, INTLEVEL=LOCKLEVEL, UM=0 + wsr a2, ps # (enable reg-windows; progmode stack) + rsync + + /* Set up EXCSAVE[DEBUGLEVEL] to point to the Debug Exception Handler.*/ + + movi a2, debug_exception + wsr a2, SREG_EXCSAVE + XCHAL_DEBUGLEVEL + +#ifdef CONFIG_SMP + /* + * Notice that we assume with SMP that cores have PRID + * supported by the cores. + */ + rsr a2, prid + bnez a2, .Lboot_secondary + +#endif /* CONFIG_SMP */ + + /* Unpack data sections + * + * The linker script used to build the Linux kernel image + * creates a table located at __boot_reloc_table_start + * that contans the information what data needs to be unpacked. + * + * Uses a2-a7. + */ + + movi a2, __boot_reloc_table_start + movi a3, __boot_reloc_table_end + +1: beq a2, a3, 3f # no more entries? + l32i a4, a2, 0 # start destination (in RAM) + l32i a5, a2, 4 # end desination (in RAM) + l32i a6, a2, 8 # start source (in ROM) + addi a2, a2, 12 # next entry + beq a4, a5, 1b # skip, empty entry + beq a4, a6, 1b # skip, source and dest. are the same + +2: l32i a7, a6, 0 # load word + addi a6, a6, 4 + s32i a7, a4, 0 # store word + addi a4, a4, 4 + bltu a4, a5, 2b + j 1b + +3: + /* All code and initialized data segments have been copied. + * Now clear the BSS segment. + */ + + movi a2, __bss_start # start of BSS + movi a3, __bss_stop # end of BSS + + __loopt a2, a3, a4, 2 + s32i a0, a2, 0 + __endla a2, a4, 4 + +#if XCHAL_DCACHE_IS_WRITEBACK + + /* After unpacking, flush the writeback cache to memory so the + * instructions/data are available. + */ + + ___flush_dcache_all a2 a3 +#endif + memw + isync + ___invalidate_icache_all a2 a3 + isync + + movi a6, 0 + xsr a6, excsave1 + + /* init_arch kick-starts the linux kernel */ + + movi a4, init_arch + callx4 a4 + + movi a4, start_kernel + callx4 a4 + +should_never_return: + j should_never_return + +#ifdef CONFIG_SMP +.Lboot_secondary: + + movi a2, cpu_start_ccount +1: + l32i a3, a2, 0 + beqi a3, 0, 1b + movi a3, 0 + s32i a3, a2, 0 + memw +1: + l32i a3, a2, 0 + beqi a3, 0, 1b + wsr a3, ccount + movi a3, 0 + s32i a3, a2, 0 + memw + + movi a6, 0 + wsr a6, excsave1 + + movi a4, secondary_start_kernel + callx4 a4 + j should_never_return + +#endif /* CONFIG_SMP */ + +ENDPROC(_startup) + +#ifdef CONFIG_HOTPLUG_CPU + +ENTRY(cpu_restart) + +#if XCHAL_DCACHE_IS_WRITEBACK + ___flush_invalidate_dcache_all a2 a3 +#else + ___invalidate_dcache_all a2 a3 +#endif + memw + movi a2, CCON # MX External Register to Configure Cache + movi a3, 0 + wer a3, a2 + extw + + rsr a0, prid + neg a2, a0 + movi a3, cpu_start_id + s32i a2, a3, 0 +#if XCHAL_DCACHE_IS_WRITEBACK + dhwbi a3, 0 +#endif +1: + l32i a2, a3, 0 + dhi a3, 0 + bne a2, a0, 1b + + /* + * Initialize WB, WS, and clear PS.EXCM (to allow loop instructions). + * Set Interrupt Level just below XCHAL_DEBUGLEVEL to allow + * xt-gdb to single step via DEBUG exceptions received directly + * by ocd. + */ + movi a1, 1 + movi a0, 0 + wsr a1, windowstart + wsr a0, windowbase + rsync + + movi a1, LOCKLEVEL + wsr a1, ps + rsync + + j _startup + +ENDPROC(cpu_restart) + +#endif /* CONFIG_HOTPLUG_CPU */ + +/* + * DATA section + */ + + .section ".data.init.refok" + .align 4 +ENTRY(start_info) + .long init_thread_union + KERNEL_STACK_SIZE + +/* + * BSS section + */ + +__PAGE_ALIGNED_BSS +#ifdef CONFIG_MMU +ENTRY(swapper_pg_dir) + .fill PAGE_SIZE, 1, 0 +END(swapper_pg_dir) +#endif +ENTRY(empty_zero_page) + .fill PAGE_SIZE, 1, 0 +END(empty_zero_page) diff --git a/arch/xtensa/kernel/irq.c b/arch/xtensa/kernel/irq.c new file mode 100644 index 000000000..3eee94f62 --- /dev/null +++ b/arch/xtensa/kernel/irq.c @@ -0,0 +1,188 @@ +/* + * linux/arch/xtensa/kernel/irq.c + * + * Xtensa built-in interrupt controller and some generic functions copied + * from i386. + * + * Copyright (C) 2002 - 2013 Tensilica, Inc. + * Copyright (C) 1992, 1998 Linus Torvalds, Ingo Molnar + * + * + * Chris Zankel <chris@zankel.net> + * Kevin Chea + * + */ + +#include <linux/module.h> +#include <linux/seq_file.h> +#include <linux/interrupt.h> +#include <linux/irq.h> +#include <linux/kernel_stat.h> +#include <linux/irqchip.h> +#include <linux/irqchip/xtensa-mx.h> +#include <linux/irqchip/xtensa-pic.h> +#include <linux/irqdomain.h> +#include <linux/of.h> + +#include <asm/mxregs.h> +#include <asm/uaccess.h> +#include <asm/platform.h> + +atomic_t irq_err_count; + +asmlinkage void do_IRQ(int hwirq, struct pt_regs *regs) +{ + int irq = irq_find_mapping(NULL, hwirq); + + if (hwirq >= NR_IRQS) { + printk(KERN_EMERG "%s: cannot handle IRQ %d\n", + __func__, hwirq); + } + +#ifdef CONFIG_DEBUG_STACKOVERFLOW + /* Debugging check for stack overflow: is there less than 1KB free? */ + { + unsigned long sp; + + __asm__ __volatile__ ("mov %0, a1\n" : "=a" (sp)); + sp &= THREAD_SIZE - 1; + + if (unlikely(sp < (sizeof(thread_info) + 1024))) + printk("Stack overflow in do_IRQ: %ld\n", + sp - sizeof(struct thread_info)); + } +#endif + generic_handle_irq(irq); +} + +int arch_show_interrupts(struct seq_file *p, int prec) +{ +#ifdef CONFIG_SMP + show_ipi_list(p, prec); +#endif + seq_printf(p, "%*s: ", prec, "ERR"); + seq_printf(p, "%10u\n", atomic_read(&irq_err_count)); + return 0; +} + +int xtensa_irq_domain_xlate(const u32 *intspec, unsigned int intsize, + unsigned long int_irq, unsigned long ext_irq, + unsigned long *out_hwirq, unsigned int *out_type) +{ + if (WARN_ON(intsize < 1 || intsize > 2)) + return -EINVAL; + if (intsize == 2 && intspec[1] == 1) { + int_irq = xtensa_map_ext_irq(ext_irq); + if (int_irq < XCHAL_NUM_INTERRUPTS) + *out_hwirq = int_irq; + else + return -EINVAL; + } else { + *out_hwirq = int_irq; + } + *out_type = IRQ_TYPE_NONE; + return 0; +} + +int xtensa_irq_map(struct irq_domain *d, unsigned int irq, + irq_hw_number_t hw) +{ + struct irq_chip *irq_chip = d->host_data; + u32 mask = 1 << hw; + + if (mask & XCHAL_INTTYPE_MASK_SOFTWARE) { + irq_set_chip_and_handler_name(irq, irq_chip, + handle_simple_irq, "level"); + irq_set_status_flags(irq, IRQ_LEVEL); + } else if (mask & XCHAL_INTTYPE_MASK_EXTERN_EDGE) { + irq_set_chip_and_handler_name(irq, irq_chip, + handle_edge_irq, "edge"); + irq_clear_status_flags(irq, IRQ_LEVEL); + } else if (mask & XCHAL_INTTYPE_MASK_EXTERN_LEVEL) { + irq_set_chip_and_handler_name(irq, irq_chip, + handle_level_irq, "level"); + irq_set_status_flags(irq, IRQ_LEVEL); + } else if (mask & XCHAL_INTTYPE_MASK_TIMER) { + irq_set_chip_and_handler_name(irq, irq_chip, + handle_percpu_irq, "timer"); + irq_clear_status_flags(irq, IRQ_LEVEL); + } else {/* XCHAL_INTTYPE_MASK_WRITE_ERROR */ + /* XCHAL_INTTYPE_MASK_NMI */ + irq_set_chip_and_handler_name(irq, irq_chip, + handle_level_irq, "level"); + irq_set_status_flags(irq, IRQ_LEVEL); + } + return 0; +} + +unsigned xtensa_map_ext_irq(unsigned ext_irq) +{ + unsigned mask = XCHAL_INTTYPE_MASK_EXTERN_EDGE | + XCHAL_INTTYPE_MASK_EXTERN_LEVEL; + unsigned i; + + for (i = 0; mask; ++i, mask >>= 1) { + if ((mask & 1) && ext_irq-- == 0) + return i; + } + return XCHAL_NUM_INTERRUPTS; +} + +unsigned xtensa_get_ext_irq_no(unsigned irq) +{ + unsigned mask = (XCHAL_INTTYPE_MASK_EXTERN_EDGE | + XCHAL_INTTYPE_MASK_EXTERN_LEVEL) & + ((1u << irq) - 1); + return hweight32(mask); +} + +void __init init_IRQ(void) +{ +#ifdef CONFIG_OF + irqchip_init(); +#else +#ifdef CONFIG_HAVE_SMP + xtensa_mx_init_legacy(NULL); +#else + xtensa_pic_init_legacy(NULL); +#endif +#endif + +#ifdef CONFIG_SMP + ipi_init(); +#endif + variant_init_irq(); +} + +#ifdef CONFIG_HOTPLUG_CPU +/* + * The CPU has been marked offline. Migrate IRQs off this CPU. If + * the affinity settings do not allow other CPUs, force them onto any + * available CPU. + */ +void migrate_irqs(void) +{ + unsigned int i, cpu = smp_processor_id(); + + for_each_active_irq(i) { + struct irq_data *data = irq_get_irq_data(i); + unsigned int newcpu; + + if (irqd_is_per_cpu(data)) + continue; + + if (!cpumask_test_cpu(cpu, data->affinity)) + continue; + + newcpu = cpumask_any_and(data->affinity, cpu_online_mask); + + if (newcpu >= nr_cpu_ids) { + pr_info_ratelimited("IRQ%u no longer affine to CPU%u\n", + i, cpu); + + cpumask_setall(data->affinity); + } + irq_set_affinity(i, data->affinity); + } +} +#endif /* CONFIG_HOTPLUG_CPU */ diff --git a/arch/xtensa/kernel/mcount.S b/arch/xtensa/kernel/mcount.S new file mode 100644 index 000000000..0eeda2e4a --- /dev/null +++ b/arch/xtensa/kernel/mcount.S @@ -0,0 +1,50 @@ +/* + * arch/xtensa/kernel/mcount.S + * + * Xtensa specific mcount support + * + * This file is subject to the terms and conditions of the GNU General Public + * License. See the file "COPYING" in the main directory of this archive + * for more details. + * + * Copyright (C) 2013 Tensilica Inc. + */ + +#include <linux/linkage.h> +#include <asm/ftrace.h> + +/* + * Entry condition: + * + * a2: a0 of the caller + */ + +ENTRY(_mcount) + + entry a1, 16 + + movi a4, ftrace_trace_function + l32i a4, a4, 0 + movi a3, ftrace_stub + bne a3, a4, 1f + retw + +1: xor a7, a2, a1 + movi a3, 0x3fffffff + and a7, a7, a3 + xor a7, a7, a1 + + xor a6, a0, a1 + and a6, a6, a3 + xor a6, a6, a1 + addi a6, a6, -MCOUNT_INSN_SIZE + callx4 a4 + + retw + +ENDPROC(_mcount) + +ENTRY(ftrace_stub) + entry a1, 16 + retw +ENDPROC(ftrace_stub) diff --git a/arch/xtensa/kernel/module.c b/arch/xtensa/kernel/module.c new file mode 100644 index 000000000..b715237ba --- /dev/null +++ b/arch/xtensa/kernel/module.c @@ -0,0 +1,192 @@ +/* + * arch/xtensa/kernel/module.c + * + * Module support. + * + * This file is subject to the terms and conditions of the GNU General Public + * License. See the file "COPYING" in the main directory of this archive + * for more details. + * + * Copyright (C) 2001 - 2006 Tensilica Inc. + * + * Chris Zankel <chris@zankel.net> + * + */ + +#include <linux/module.h> +#include <linux/moduleloader.h> +#include <linux/elf.h> +#include <linux/vmalloc.h> +#include <linux/fs.h> +#include <linux/string.h> +#include <linux/kernel.h> +#include <linux/cache.h> + +#undef DEBUG_RELOCATE + +static int +decode_calln_opcode (unsigned char *location) +{ +#ifdef __XTENSA_EB__ + return (location[0] & 0xf0) == 0x50; +#endif +#ifdef __XTENSA_EL__ + return (location[0] & 0xf) == 0x5; +#endif +} + +static int +decode_l32r_opcode (unsigned char *location) +{ +#ifdef __XTENSA_EB__ + return (location[0] & 0xf0) == 0x10; +#endif +#ifdef __XTENSA_EL__ + return (location[0] & 0xf) == 0x1; +#endif +} + +int apply_relocate_add(Elf32_Shdr *sechdrs, + const char *strtab, + unsigned int symindex, + unsigned int relsec, + struct module *mod) +{ + unsigned int i; + Elf32_Rela *rela = (void *)sechdrs[relsec].sh_addr; + Elf32_Sym *sym; + unsigned char *location; + uint32_t value; + +#ifdef DEBUG_RELOCATE + printk("Applying relocate section %u to %u\n", relsec, + sechdrs[relsec].sh_info); +#endif + for (i = 0; i < sechdrs[relsec].sh_size / sizeof(*rela); i++) { + location = (char *)sechdrs[sechdrs[relsec].sh_info].sh_addr + + rela[i].r_offset; + sym = (Elf32_Sym *)sechdrs[symindex].sh_addr + + ELF32_R_SYM(rela[i].r_info); + value = sym->st_value + rela[i].r_addend; + + switch (ELF32_R_TYPE(rela[i].r_info)) { + case R_XTENSA_NONE: + case R_XTENSA_DIFF8: + case R_XTENSA_DIFF16: + case R_XTENSA_DIFF32: + case R_XTENSA_ASM_EXPAND: + break; + + case R_XTENSA_32: + case R_XTENSA_PLT: + *(uint32_t *)location += value; + break; + + case R_XTENSA_SLOT0_OP: + if (decode_calln_opcode(location)) { + value -= ((unsigned long)location & -4) + 4; + if ((value & 3) != 0 || + ((value + (1 << 19)) >> 20) != 0) { + printk("%s: relocation out of range, " + "section %d reloc %d " + "sym '%s'\n", + mod->name, relsec, i, + strtab + sym->st_name); + return -ENOEXEC; + } + value = (signed int)value >> 2; +#ifdef __XTENSA_EB__ + location[0] = ((location[0] & ~0x3) | + ((value >> 16) & 0x3)); + location[1] = (value >> 8) & 0xff; + location[2] = value & 0xff; +#endif +#ifdef __XTENSA_EL__ + location[0] = ((location[0] & ~0xc0) | + ((value << 6) & 0xc0)); + location[1] = (value >> 2) & 0xff; + location[2] = (value >> 10) & 0xff; +#endif + } else if (decode_l32r_opcode(location)) { + value -= (((unsigned long)location + 3) & -4); + if ((value & 3) != 0 || + (signed int)value >> 18 != -1) { + printk("%s: relocation out of range, " + "section %d reloc %d " + "sym '%s'\n", + mod->name, relsec, i, + strtab + sym->st_name); + return -ENOEXEC; + } + value = (signed int)value >> 2; + +#ifdef __XTENSA_EB__ + location[1] = (value >> 8) & 0xff; + location[2] = value & 0xff; +#endif +#ifdef __XTENSA_EL__ + location[1] = value & 0xff; + location[2] = (value >> 8) & 0xff; +#endif + } + /* FIXME: Ignore any other opcodes. The Xtensa + assembler currently assumes that the linker will + always do relaxation and so all PC-relative + operands need relocations. (The assembler also + writes out the tentative PC-relative values, + assuming no link-time relaxation, so it is usually + safe to ignore the relocations.) If the + assembler's "--no-link-relax" flag can be made to + work, and if all kernel modules can be assembled + with that flag, then unexpected relocations could + be detected here. */ + break; + + case R_XTENSA_SLOT1_OP: + case R_XTENSA_SLOT2_OP: + case R_XTENSA_SLOT3_OP: + case R_XTENSA_SLOT4_OP: + case R_XTENSA_SLOT5_OP: + case R_XTENSA_SLOT6_OP: + case R_XTENSA_SLOT7_OP: + case R_XTENSA_SLOT8_OP: + case R_XTENSA_SLOT9_OP: + case R_XTENSA_SLOT10_OP: + case R_XTENSA_SLOT11_OP: + case R_XTENSA_SLOT12_OP: + case R_XTENSA_SLOT13_OP: + case R_XTENSA_SLOT14_OP: + printk("%s: unexpected FLIX relocation: %u\n", + mod->name, + ELF32_R_TYPE(rela[i].r_info)); + return -ENOEXEC; + + case R_XTENSA_SLOT0_ALT: + case R_XTENSA_SLOT1_ALT: + case R_XTENSA_SLOT2_ALT: + case R_XTENSA_SLOT3_ALT: + case R_XTENSA_SLOT4_ALT: + case R_XTENSA_SLOT5_ALT: + case R_XTENSA_SLOT6_ALT: + case R_XTENSA_SLOT7_ALT: + case R_XTENSA_SLOT8_ALT: + case R_XTENSA_SLOT9_ALT: + case R_XTENSA_SLOT10_ALT: + case R_XTENSA_SLOT11_ALT: + case R_XTENSA_SLOT12_ALT: + case R_XTENSA_SLOT13_ALT: + case R_XTENSA_SLOT14_ALT: + printk("%s: unexpected ALT relocation: %u\n", + mod->name, + ELF32_R_TYPE(rela[i].r_info)); + return -ENOEXEC; + + default: + printk("%s: unexpected relocation: %u\n", + mod->name, + ELF32_R_TYPE(rela[i].r_info)); + return -ENOEXEC; + } + } + return 0; +} diff --git a/arch/xtensa/kernel/mxhead.S b/arch/xtensa/kernel/mxhead.S new file mode 100644 index 000000000..77a161a11 --- /dev/null +++ b/arch/xtensa/kernel/mxhead.S @@ -0,0 +1,85 @@ +/* + * Xtensa Secondary Processors startup code. + * + * This file is subject to the terms and conditions of the GNU General Public + * License. See the file "COPYING" in the main directory of this archive + * for more details. + * + * Copyright (C) 2001 - 2013 Tensilica Inc. + * + * Joe Taylor <joe@tensilica.com> + * Chris Zankel <chris@zankel.net> + * Marc Gauthier <marc@tensilica.com, marc@alumni.uwaterloo.ca> + * Pete Delaney <piet@tensilica.com> + */ + +#include <linux/linkage.h> + +#include <asm/cacheasm.h> +#include <asm/initialize_mmu.h> +#include <asm/mxregs.h> +#include <asm/regs.h> + + + .section .SecondaryResetVector.text, "ax" + + +ENTRY(_SecondaryResetVector) + _j _SetupOCD + + .begin no-absolute-literals + .literal_position + +_SetupOCD: + /* + * Initialize WB, WS, and clear PS.EXCM (to allow loop instructions). + * Set Interrupt Level just below XCHAL_DEBUGLEVEL to allow + * xt-gdb to single step via DEBUG exceptions received directly + * by ocd. + */ + movi a1, 1 + movi a0, 0 + wsr a1, windowstart + wsr a0, windowbase + rsync + + movi a1, LOCKLEVEL + wsr a1, ps + rsync + +_SetupMMU: + Offset = _SetupMMU - _SecondaryResetVector + +#ifdef CONFIG_INITIALIZE_XTENSA_MMU_INSIDE_VMLINUX + initialize_mmu +#endif + + /* + * Start Secondary Processors with NULL pointer to boot params. + */ + movi a2, 0 # a2 == NULL + movi a3, _startup + jx a3 + + .end no-absolute-literals + + + .section .SecondaryResetVector.remapped_text, "ax" + .global _RemappedSecondaryResetVector + + .org 0 # Need to do org before literals + +_RemappedSecondaryResetVector: + .begin no-absolute-literals + .literal_position + + _j _RemappedSetupMMU + . = _RemappedSecondaryResetVector + Offset + +_RemappedSetupMMU: + +#ifdef CONFIG_INITIALIZE_XTENSA_MMU_INSIDE_VMLINUX + initialize_mmu +#endif + + .end no-absolute-literals diff --git a/arch/xtensa/kernel/pci-dma.c b/arch/xtensa/kernel/pci-dma.c new file mode 100644 index 000000000..e8b76b8e4 --- /dev/null +++ b/arch/xtensa/kernel/pci-dma.c @@ -0,0 +1,98 @@ +/* + * arch/xtensa/kernel/pci-dma.c + * + * DMA coherent memory allocation. + * + * This program is free software; you can redistribute it and/or modify it + * under the terms of the GNU General Public License as published by the + * Free Software Foundation; either version 2 of the License, or (at your + * option) any later version. + * + * Copyright (C) 2002 - 2005 Tensilica Inc. + * + * Based on version for i386. + * + * Chris Zankel <chris@zankel.net> + * Joe Taylor <joe@tensilica.com, joetylr@yahoo.com> + */ + +#include <linux/types.h> +#include <linux/mm.h> +#include <linux/string.h> +#include <linux/pci.h> +#include <linux/gfp.h> +#include <linux/module.h> +#include <asm/io.h> +#include <asm/cacheflush.h> + +/* + * Note: We assume that the full memory space is always mapped to 'kseg' + * Otherwise we have to use page attributes (not implemented). + */ + +void * +dma_alloc_coherent(struct device *dev,size_t size,dma_addr_t *handle,gfp_t flag) +{ + unsigned long ret; + unsigned long uncached = 0; + + /* ignore region speicifiers */ + + flag &= ~(__GFP_DMA | __GFP_HIGHMEM); + + if (dev == NULL || (dev->coherent_dma_mask < 0xffffffff)) + flag |= GFP_DMA; + ret = (unsigned long)__get_free_pages(flag, get_order(size)); + + if (ret == 0) + return NULL; + + /* We currently don't support coherent memory outside KSEG */ + + BUG_ON(ret < XCHAL_KSEG_CACHED_VADDR || + ret > XCHAL_KSEG_CACHED_VADDR + XCHAL_KSEG_SIZE - 1); + + + if (ret != 0) { + memset((void*) ret, 0, size); + uncached = ret+XCHAL_KSEG_BYPASS_VADDR-XCHAL_KSEG_CACHED_VADDR; + *handle = virt_to_bus((void*)ret); + __flush_invalidate_dcache_range(ret, size); + } + + return (void*)uncached; +} +EXPORT_SYMBOL(dma_alloc_coherent); + +void dma_free_coherent(struct device *hwdev, size_t size, + void *vaddr, dma_addr_t dma_handle) +{ + unsigned long addr = (unsigned long)vaddr + + XCHAL_KSEG_CACHED_VADDR - XCHAL_KSEG_BYPASS_VADDR; + + BUG_ON(addr < XCHAL_KSEG_CACHED_VADDR || + addr > XCHAL_KSEG_CACHED_VADDR + XCHAL_KSEG_SIZE - 1); + + free_pages(addr, get_order(size)); +} +EXPORT_SYMBOL(dma_free_coherent); + + +void consistent_sync(void *vaddr, size_t size, int direction) +{ + switch (direction) { + case PCI_DMA_NONE: + BUG(); + case PCI_DMA_FROMDEVICE: /* invalidate only */ + __invalidate_dcache_range((unsigned long)vaddr, + (unsigned long)size); + break; + + case PCI_DMA_TODEVICE: /* writeback only */ + case PCI_DMA_BIDIRECTIONAL: /* writeback and invalidate */ + __flush_invalidate_dcache_range((unsigned long)vaddr, + (unsigned long)size); + break; + } +} +EXPORT_SYMBOL(consistent_sync); diff --git a/arch/xtensa/kernel/pci.c b/arch/xtensa/kernel/pci.c new file mode 100644 index 000000000..b848cc3dc --- /dev/null +++ b/arch/xtensa/kernel/pci.c @@ -0,0 +1,381 @@ +/* + * arch/xtensa/kernel/pci.c + * + * PCI bios-type initialisation for PCI machines + * + * This program is free software; you can redistribute it and/or modify it + * under the terms of the GNU General Public License as published by the + * Free Software Foundation; either version 2 of the License, or (at your + * option) any later version. + * + * Copyright (C) 2001-2005 Tensilica Inc. + * + * Based largely on work from Cort (ppc/kernel/pci.c) + * IO functions copied from sparc. + * + * Chris Zankel <chris@zankel.net> + * + */ + +#include <linux/kernel.h> +#include <linux/pci.h> +#include <linux/delay.h> +#include <linux/string.h> +#include <linux/init.h> +#include <linux/sched.h> +#include <linux/errno.h> +#include <linux/bootmem.h> + +#include <asm/pci-bridge.h> +#include <asm/platform.h> + +#undef DEBUG + +#ifdef DEBUG +#define DBG(x...) printk(x) +#else +#define DBG(x...) +#endif + +/* PCI Controller */ + + +/* + * pcibios_alloc_controller + * pcibios_enable_device + * pcibios_fixups + * pcibios_align_resource + * pcibios_fixup_bus + * pci_bus_add_device + * pci_mmap_page_range + */ + +struct pci_controller* pci_ctrl_head; +struct pci_controller** pci_ctrl_tail = &pci_ctrl_head; + +static int pci_bus_count; + +/* + * We need to avoid collisions with `mirrored' VGA ports + * and other strange ISA hardware, so we always want the + * addresses to be allocated in the 0x000-0x0ff region + * modulo 0x400. + * + * Why? Because some silly external IO cards only decode + * the low 10 bits of the IO address. The 0x00-0xff region + * is reserved for motherboard devices that decode all 16 + * bits, so it's ok to allocate at, say, 0x2800-0x28ff, + * but we want to try to avoid allocating at 0x2900-0x2bff + * which might have be mirrored at 0x0100-0x03ff.. + */ +resource_size_t +pcibios_align_resource(void *data, const struct resource *res, + resource_size_t size, resource_size_t align) +{ + struct pci_dev *dev = data; + resource_size_t start = res->start; + + if (res->flags & IORESOURCE_IO) { + if (size > 0x100) { + pr_err("PCI: I/O Region %s/%d too large (%u bytes)\n", + pci_name(dev), dev->resource - res, + size); + } + + if (start & 0x300) + start = (start + 0x3ff) & ~0x3ff; + } + + return start; +} + +int +pcibios_enable_resources(struct pci_dev *dev, int mask) +{ + u16 cmd, old_cmd; + int idx; + struct resource *r; + + pci_read_config_word(dev, PCI_COMMAND, &cmd); + old_cmd = cmd; + for(idx=0; idx<6; idx++) { + r = &dev->resource[idx]; + if (!r->start && r->end) { + printk (KERN_ERR "PCI: Device %s not available because " + "of resource collisions\n", pci_name(dev)); + return -EINVAL; + } + if (r->flags & IORESOURCE_IO) + cmd |= PCI_COMMAND_IO; + if (r->flags & IORESOURCE_MEM) + cmd |= PCI_COMMAND_MEMORY; + } + if (dev->resource[PCI_ROM_RESOURCE].start) + cmd |= PCI_COMMAND_MEMORY; + if (cmd != old_cmd) { + printk("PCI: Enabling device %s (%04x -> %04x)\n", + pci_name(dev), old_cmd, cmd); + pci_write_config_word(dev, PCI_COMMAND, cmd); + } + return 0; +} + +struct pci_controller * __init pcibios_alloc_controller(void) +{ + struct pci_controller *pci_ctrl; + + pci_ctrl = (struct pci_controller *)alloc_bootmem(sizeof(*pci_ctrl)); + memset(pci_ctrl, 0, sizeof(struct pci_controller)); + + *pci_ctrl_tail = pci_ctrl; + pci_ctrl_tail = &pci_ctrl->next; + + return pci_ctrl; +} + +static void __init pci_controller_apertures(struct pci_controller *pci_ctrl, + struct list_head *resources) +{ + struct resource *res; + unsigned long io_offset; + int i; + + io_offset = (unsigned long)pci_ctrl->io_space.base; + res = &pci_ctrl->io_resource; + if (!res->flags) { + if (io_offset) + printk (KERN_ERR "I/O resource not set for host" + " bridge %d\n", pci_ctrl->index); + res->start = 0; + res->end = IO_SPACE_LIMIT; + res->flags = IORESOURCE_IO; + } + res->start += io_offset; + res->end += io_offset; + pci_add_resource_offset(resources, res, io_offset); + + for (i = 0; i < 3; i++) { + res = &pci_ctrl->mem_resources[i]; + if (!res->flags) { + if (i > 0) + continue; + printk(KERN_ERR "Memory resource not set for " + "host bridge %d\n", pci_ctrl->index); + res->start = 0; + res->end = ~0U; + res->flags = IORESOURCE_MEM; + } + pci_add_resource(resources, res); + } +} + +static int __init pcibios_init(void) +{ + struct pci_controller *pci_ctrl; + struct list_head resources; + struct pci_bus *bus; + int next_busno = 0, ret; + + printk("PCI: Probing PCI hardware\n"); + + /* Scan all of the recorded PCI controllers. */ + for (pci_ctrl = pci_ctrl_head; pci_ctrl; pci_ctrl = pci_ctrl->next) { + pci_ctrl->last_busno = 0xff; + INIT_LIST_HEAD(&resources); + pci_controller_apertures(pci_ctrl, &resources); + bus = pci_scan_root_bus(NULL, pci_ctrl->first_busno, + pci_ctrl->ops, pci_ctrl, &resources); + if (!bus) + continue; + + pci_ctrl->bus = bus; + pci_ctrl->last_busno = bus->busn_res.end; + if (next_busno <= pci_ctrl->last_busno) + next_busno = pci_ctrl->last_busno+1; + } + pci_bus_count = next_busno; + ret = platform_pcibios_fixup(); + if (ret) + return ret; + + for (pci_ctrl = pci_ctrl_head; pci_ctrl; pci_ctrl = pci_ctrl->next) { + if (pci_ctrl->bus) + pci_bus_add_devices(pci_ctrl->bus); + } + + return 0; +} + +subsys_initcall(pcibios_init); + +void pcibios_fixup_bus(struct pci_bus *bus) +{ + if (bus->parent) { + /* This is a subordinate bridge */ + pci_read_bridge_bases(bus); + } +} + +void pcibios_set_master(struct pci_dev *dev) +{ + /* No special bus mastering setup handling */ +} + +int pcibios_enable_device(struct pci_dev *dev, int mask) +{ + u16 cmd, old_cmd; + int idx; + struct resource *r; + + pci_read_config_word(dev, PCI_COMMAND, &cmd); + old_cmd = cmd; + for (idx=0; idx<6; idx++) { + r = &dev->resource[idx]; + if (!r->start && r->end) { + printk(KERN_ERR "PCI: Device %s not available because " + "of resource collisions\n", pci_name(dev)); + return -EINVAL; + } + if (r->flags & IORESOURCE_IO) + cmd |= PCI_COMMAND_IO; + if (r->flags & IORESOURCE_MEM) + cmd |= PCI_COMMAND_MEMORY; + } + if (cmd != old_cmd) { + printk("PCI: Enabling device %s (%04x -> %04x)\n", + pci_name(dev), old_cmd, cmd); + pci_write_config_word(dev, PCI_COMMAND, cmd); + } + + return 0; +} + +#ifdef CONFIG_PROC_FS + +/* + * Return the index of the PCI controller for device pdev. + */ + +int +pci_controller_num(struct pci_dev *dev) +{ + struct pci_controller *pci_ctrl = (struct pci_controller*) dev->sysdata; + return pci_ctrl->index; +} + +#endif /* CONFIG_PROC_FS */ + +/* + * Platform support for /proc/bus/pci/X/Y mmap()s, + * modelled on the sparc64 implementation by Dave Miller. + * -- paulus. + */ + +/* + * Adjust vm_pgoff of VMA such that it is the physical page offset + * corresponding to the 32-bit pci bus offset for DEV requested by the user. + * + * Basically, the user finds the base address for his device which he wishes + * to mmap. They read the 32-bit value from the config space base register, + * add whatever PAGE_SIZE multiple offset they wish, and feed this into the + * offset parameter of mmap on /proc/bus/pci/XXX for that device. + * + * Returns negative error code on failure, zero on success. + */ +static __inline__ int +__pci_mmap_make_offset(struct pci_dev *dev, struct vm_area_struct *vma, + enum pci_mmap_state mmap_state) +{ + struct pci_controller *pci_ctrl = (struct pci_controller*) dev->sysdata; + unsigned long offset = vma->vm_pgoff << PAGE_SHIFT; + unsigned long io_offset = 0; + int i, res_bit; + + if (pci_ctrl == 0) + return -EINVAL; /* should never happen */ + + /* If memory, add on the PCI bridge address offset */ + if (mmap_state == pci_mmap_mem) { + res_bit = IORESOURCE_MEM; + } else { + io_offset = (unsigned long)pci_ctrl->io_space.base; + offset += io_offset; + res_bit = IORESOURCE_IO; + } + + /* + * Check that the offset requested corresponds to one of the + * resources of the device. + */ + for (i = 0; i <= PCI_ROM_RESOURCE; i++) { + struct resource *rp = &dev->resource[i]; + int flags = rp->flags; + + /* treat ROM as memory (should be already) */ + if (i == PCI_ROM_RESOURCE) + flags |= IORESOURCE_MEM; + + /* Active and same type? */ + if ((flags & res_bit) == 0) + continue; + + /* In the range of this resource? */ + if (offset < (rp->start & PAGE_MASK) || offset > rp->end) + continue; + + /* found it! construct the final physical address */ + if (mmap_state == pci_mmap_io) + offset += pci_ctrl->io_space.start - io_offset; + vma->vm_pgoff = offset >> PAGE_SHIFT; + return 0; + } + + return -EINVAL; +} + +/* + * Set vm_page_prot of VMA, as appropriate for this architecture, for a pci + * device mapping. + */ +static __inline__ void +__pci_mmap_set_pgprot(struct pci_dev *dev, struct vm_area_struct *vma, + enum pci_mmap_state mmap_state, int write_combine) +{ + int prot = pgprot_val(vma->vm_page_prot); + + /* Set to write-through */ + prot = (prot & _PAGE_CA_MASK) | _PAGE_CA_WT; +#if 0 + if (!write_combine) + prot |= _PAGE_WRITETHRU; +#endif + vma->vm_page_prot = __pgprot(prot); +} + +/* + * Perform the actual remap of the pages for a PCI device mapping, as + * appropriate for this architecture. The region in the process to map + * is described by vm_start and vm_end members of VMA, the base physical + * address is found in vm_pgoff. + * The pci device structure is provided so that architectures may make mapping + * decisions on a per-device or per-bus basis. + * + * Returns a negative error code on failure, zero on success. + */ +int pci_mmap_page_range(struct pci_dev *dev, struct vm_area_struct *vma, + enum pci_mmap_state mmap_state, + int write_combine) +{ + int ret; + + ret = __pci_mmap_make_offset(dev, vma, mmap_state); + if (ret < 0) + return ret; + + __pci_mmap_set_pgprot(dev, vma, mmap_state, write_combine); + + ret = io_remap_pfn_range(vma, vma->vm_start, vma->vm_pgoff, + vma->vm_end - vma->vm_start,vma->vm_page_prot); + + return ret; +} diff --git a/arch/xtensa/kernel/platform.c b/arch/xtensa/kernel/platform.c new file mode 100644 index 000000000..1cf008284 --- /dev/null +++ b/arch/xtensa/kernel/platform.c @@ -0,0 +1,46 @@ +/* + * arch/xtensa/kernel/platform.c + * + * Default platform functions. + * + * This file is subject to the terms and conditions of the GNU General Public + * License. See the file "COPYING" in the main directory of this archive + * for more details. + * + * Copyright (C) 2005 Tensilica Inc. + * + * Chris Zankel <chris@zankel.net> + */ + +#include <linux/types.h> +#include <linux/pci.h> +#include <linux/time.h> +#include <asm/platform.h> +#include <asm/timex.h> +#include <asm/param.h> /* HZ */ + +#define _F(r,f,a,b) \ + r __platform_##f a b; \ + r platform_##f a __attribute__((weak, alias("__platform_"#f))) + +/* + * Default functions that are used if no platform specific function is defined. + * (Please, refer to include/asm-xtensa/platform.h for more information) + */ + +_F(void, setup, (char** cmd), { }); +_F(void, restart, (void), { while(1); }); +_F(void, halt, (void), { while(1); }); +_F(void, power_off, (void), { while(1); }); +_F(void, idle, (void), { __asm__ __volatile__ ("waiti 0" ::: "memory"); }); +_F(void, heartbeat, (void), { }); +_F(int, pcibios_fixup, (void), { return 0; }); +_F(void, pcibios_init, (void), { }); + +#ifdef CONFIG_XTENSA_CALIBRATE_CCOUNT +_F(void, calibrate_ccount, (void), +{ + pr_err("ERROR: Cannot calibrate cpu frequency! Assuming 10MHz.\n"); + ccount_freq = 10 * 1000000UL; +}); +#endif diff --git a/arch/xtensa/kernel/process.c b/arch/xtensa/kernel/process.c new file mode 100644 index 000000000..1c85323f0 --- /dev/null +++ b/arch/xtensa/kernel/process.c @@ -0,0 +1,356 @@ +/* + * arch/xtensa/kernel/process.c + * + * Xtensa Processor version. + * + * This file is subject to the terms and conditions of the GNU General Public + * License. See the file "COPYING" in the main directory of this archive + * for more details. + * + * Copyright (C) 2001 - 2005 Tensilica Inc. + * + * Joe Taylor <joe@tensilica.com, joetylr@yahoo.com> + * Chris Zankel <chris@zankel.net> + * Marc Gauthier <marc@tensilica.com, marc@alumni.uwaterloo.ca> + * Kevin Chea + */ + +#include <linux/errno.h> +#include <linux/sched.h> +#include <linux/kernel.h> +#include <linux/mm.h> +#include <linux/smp.h> +#include <linux/stddef.h> +#include <linux/unistd.h> +#include <linux/ptrace.h> +#include <linux/elf.h> +#include <linux/init.h> +#include <linux/prctl.h> +#include <linux/init_task.h> +#include <linux/module.h> +#include <linux/mqueue.h> +#include <linux/fs.h> +#include <linux/slab.h> +#include <linux/rcupdate.h> + +#include <asm/pgtable.h> +#include <asm/uaccess.h> +#include <asm/io.h> +#include <asm/processor.h> +#include <asm/platform.h> +#include <asm/mmu.h> +#include <asm/irq.h> +#include <linux/atomic.h> +#include <asm/asm-offsets.h> +#include <asm/regs.h> + +extern void ret_from_fork(void); +extern void ret_from_kernel_thread(void); + +struct task_struct *current_set[NR_CPUS] = {&init_task, }; + +void (*pm_power_off)(void) = NULL; +EXPORT_SYMBOL(pm_power_off); + + +#if XTENSA_HAVE_COPROCESSORS + +void coprocessor_release_all(struct thread_info *ti) +{ + unsigned long cpenable; + int i; + + /* Make sure we don't switch tasks during this operation. */ + + preempt_disable(); + + /* Walk through all cp owners and release it for the requested one. */ + + cpenable = ti->cpenable; + + for (i = 0; i < XCHAL_CP_MAX; i++) { + if (coprocessor_owner[i] == ti) { + coprocessor_owner[i] = 0; + cpenable &= ~(1 << i); + } + } + + ti->cpenable = cpenable; + coprocessor_clear_cpenable(); + + preempt_enable(); +} + +void coprocessor_flush_all(struct thread_info *ti) +{ + unsigned long cpenable; + int i; + + preempt_disable(); + + cpenable = ti->cpenable; + + for (i = 0; i < XCHAL_CP_MAX; i++) { + if ((cpenable & 1) != 0 && coprocessor_owner[i] == ti) + coprocessor_flush(ti, i); + cpenable >>= 1; + } + + preempt_enable(); +} + +#endif + + +/* + * Powermanagement idle function, if any is provided by the platform. + */ +void arch_cpu_idle(void) +{ + platform_idle(); +} + +/* + * This is called when the thread calls exit(). + */ +void exit_thread(void) +{ +#if XTENSA_HAVE_COPROCESSORS + coprocessor_release_all(current_thread_info()); +#endif +} + +/* + * Flush thread state. This is called when a thread does an execve() + * Note that we flush coprocessor registers for the case execve fails. + */ +void flush_thread(void) +{ +#if XTENSA_HAVE_COPROCESSORS + struct thread_info *ti = current_thread_info(); + coprocessor_flush_all(ti); + coprocessor_release_all(ti); +#endif +} + +/* + * this gets called so that we can store coprocessor state into memory and + * copy the current task into the new thread. + */ +int arch_dup_task_struct(struct task_struct *dst, struct task_struct *src) +{ +#if XTENSA_HAVE_COPROCESSORS + coprocessor_flush_all(task_thread_info(src)); +#endif + *dst = *src; + return 0; +} + +/* + * Copy thread. + * + * There are two modes in which this function is called: + * 1) Userspace thread creation, + * regs != NULL, usp_thread_fn is userspace stack pointer. + * It is expected to copy parent regs (in case CLONE_VM is not set + * in the clone_flags) and set up passed usp in the childregs. + * 2) Kernel thread creation, + * regs == NULL, usp_thread_fn is the function to run in the new thread + * and thread_fn_arg is its parameter. + * childregs are not used for the kernel threads. + * + * The stack layout for the new thread looks like this: + * + * +------------------------+ + * | childregs | + * +------------------------+ <- thread.sp = sp in dummy-frame + * | dummy-frame | (saved in dummy-frame spill-area) + * +------------------------+ + * + * We create a dummy frame to return to either ret_from_fork or + * ret_from_kernel_thread: + * a0 points to ret_from_fork/ret_from_kernel_thread (simulating a call4) + * sp points to itself (thread.sp) + * a2, a3 are unused for userspace threads, + * a2 points to thread_fn, a3 holds thread_fn arg for kernel threads. + * + * Note: This is a pristine frame, so we don't need any spill region on top of + * childregs. + * + * The fun part: if we're keeping the same VM (i.e. cloning a thread, + * not an entire process), we're normally given a new usp, and we CANNOT share + * any live address register windows. If we just copy those live frames over, + * the two threads (parent and child) will overflow the same frames onto the + * parent stack at different times, likely corrupting the parent stack (esp. + * if the parent returns from functions that called clone() and calls new + * ones, before the child overflows its now old copies of its parent windows). + * One solution is to spill windows to the parent stack, but that's fairly + * involved. Much simpler to just not copy those live frames across. + */ + +int copy_thread(unsigned long clone_flags, unsigned long usp_thread_fn, + unsigned long thread_fn_arg, struct task_struct *p) +{ + struct pt_regs *childregs = task_pt_regs(p); + +#if (XTENSA_HAVE_COPROCESSORS || XTENSA_HAVE_IO_PORTS) + struct thread_info *ti; +#endif + + /* Create a call4 dummy-frame: a0 = 0, a1 = childregs. */ + *((int*)childregs - 3) = (unsigned long)childregs; + *((int*)childregs - 4) = 0; + + p->thread.sp = (unsigned long)childregs; + + if (!(p->flags & PF_KTHREAD)) { + struct pt_regs *regs = current_pt_regs(); + unsigned long usp = usp_thread_fn ? + usp_thread_fn : regs->areg[1]; + + p->thread.ra = MAKE_RA_FOR_CALL( + (unsigned long)ret_from_fork, 0x1); + + /* This does not copy all the regs. + * In a bout of brilliance or madness, + * ARs beyond a0-a15 exist past the end of the struct. + */ + *childregs = *regs; + childregs->areg[1] = usp; + childregs->areg[2] = 0; + + /* When sharing memory with the parent thread, the child + usually starts on a pristine stack, so we have to reset + windowbase, windowstart and wmask. + (Note that such a new thread is required to always create + an initial call4 frame) + The exception is vfork, where the new thread continues to + run on the parent's stack until it calls execve. This could + be a call8 or call12, which requires a legal stack frame + of the previous caller for the overflow handlers to work. + (Note that it's always legal to overflow live registers). + In this case, ensure to spill at least the stack pointer + of that frame. */ + + if (clone_flags & CLONE_VM) { + /* check that caller window is live and same stack */ + int len = childregs->wmask & ~0xf; + if (regs->areg[1] == usp && len != 0) { + int callinc = (regs->areg[0] >> 30) & 3; + int caller_ars = XCHAL_NUM_AREGS - callinc * 4; + put_user(regs->areg[caller_ars+1], + (unsigned __user*)(usp - 12)); + } + childregs->wmask = 1; + childregs->windowstart = 1; + childregs->windowbase = 0; + } else { + int len = childregs->wmask & ~0xf; + memcpy(&childregs->areg[XCHAL_NUM_AREGS - len/4], + ®s->areg[XCHAL_NUM_AREGS - len/4], len); + } + + /* The thread pointer is passed in the '4th argument' (= a5) */ + if (clone_flags & CLONE_SETTLS) + childregs->threadptr = childregs->areg[5]; + } else { + p->thread.ra = MAKE_RA_FOR_CALL( + (unsigned long)ret_from_kernel_thread, 1); + + /* pass parameters to ret_from_kernel_thread: + * a2 = thread_fn, a3 = thread_fn arg + */ + *((int *)childregs - 1) = thread_fn_arg; + *((int *)childregs - 2) = usp_thread_fn; + + /* Childregs are only used when we're going to userspace + * in which case start_thread will set them up. + */ + } + +#if (XTENSA_HAVE_COPROCESSORS || XTENSA_HAVE_IO_PORTS) + ti = task_thread_info(p); + ti->cpenable = 0; +#endif + + return 0; +} + + +/* + * These bracket the sleeping functions.. + */ + +unsigned long get_wchan(struct task_struct *p) +{ + unsigned long sp, pc; + unsigned long stack_page = (unsigned long) task_stack_page(p); + int count = 0; + + if (!p || p == current || p->state == TASK_RUNNING) + return 0; + + sp = p->thread.sp; + pc = MAKE_PC_FROM_RA(p->thread.ra, p->thread.sp); + + do { + if (sp < stack_page + sizeof(struct task_struct) || + sp >= (stack_page + THREAD_SIZE) || + pc == 0) + return 0; + if (!in_sched_functions(pc)) + return pc; + + /* Stack layout: sp-4: ra, sp-3: sp' */ + + pc = MAKE_PC_FROM_RA(*(unsigned long*)sp - 4, sp); + sp = *(unsigned long *)sp - 3; + } while (count++ < 16); + return 0; +} + +/* + * xtensa_gregset_t and 'struct pt_regs' are vastly different formats + * of processor registers. Besides different ordering, + * xtensa_gregset_t contains non-live register information that + * 'struct pt_regs' does not. Exception handling (primarily) uses + * 'struct pt_regs'. Core files and ptrace use xtensa_gregset_t. + * + */ + +void xtensa_elf_core_copy_regs (xtensa_gregset_t *elfregs, struct pt_regs *regs) +{ + unsigned long wb, ws, wm; + int live, last; + + wb = regs->windowbase; + ws = regs->windowstart; + wm = regs->wmask; + ws = ((ws >> wb) | (ws << (WSBITS - wb))) & ((1 << WSBITS) - 1); + + /* Don't leak any random bits. */ + + memset(elfregs, 0, sizeof(*elfregs)); + + /* Note: PS.EXCM is not set while user task is running; its + * being set in regs->ps is for exception handling convenience. + */ + + elfregs->pc = regs->pc; + elfregs->ps = (regs->ps & ~(1 << PS_EXCM_BIT)); + elfregs->lbeg = regs->lbeg; + elfregs->lend = regs->lend; + elfregs->lcount = regs->lcount; + elfregs->sar = regs->sar; + elfregs->windowstart = ws; + + live = (wm & 2) ? 4 : (wm & 4) ? 8 : (wm & 8) ? 12 : 16; + last = XCHAL_NUM_AREGS - (wm >> 4) * 4; + memcpy(elfregs->a, regs->areg, live * 4); + memcpy(elfregs->a + last, regs->areg + last, (wm >> 4) * 16); +} + +int dump_fpu(void) +{ + return 0; +} diff --git a/arch/xtensa/kernel/ptrace.c b/arch/xtensa/kernel/ptrace.c new file mode 100644 index 000000000..4d54b4811 --- /dev/null +++ b/arch/xtensa/kernel/ptrace.c @@ -0,0 +1,354 @@ +// TODO some minor issues +/* + * This file is subject to the terms and conditions of the GNU General Public + * License. See the file "COPYING" in the main directory of this archive + * for more details. + * + * Copyright (C) 2001 - 2007 Tensilica Inc. + * + * Joe Taylor <joe@tensilica.com, joetylr@yahoo.com> + * Chris Zankel <chris@zankel.net> + * Scott Foehner<sfoehner@yahoo.com>, + * Kevin Chea + * Marc Gauthier<marc@tensilica.com> <marc@alumni.uwaterloo.ca> + */ + +#include <linux/kernel.h> +#include <linux/sched.h> +#include <linux/mm.h> +#include <linux/errno.h> +#include <linux/ptrace.h> +#include <linux/smp.h> +#include <linux/security.h> +#include <linux/signal.h> + +#include <asm/pgtable.h> +#include <asm/page.h> +#include <asm/uaccess.h> +#include <asm/ptrace.h> +#include <asm/elf.h> +#include <asm/coprocessor.h> + + +void user_enable_single_step(struct task_struct *child) +{ + child->ptrace |= PT_SINGLESTEP; +} + +void user_disable_single_step(struct task_struct *child) +{ + child->ptrace &= ~PT_SINGLESTEP; +} + +/* + * Called by kernel/ptrace.c when detaching to disable single stepping. + */ + +void ptrace_disable(struct task_struct *child) +{ + /* Nothing to do.. */ +} + +int ptrace_getregs(struct task_struct *child, void __user *uregs) +{ + struct pt_regs *regs = task_pt_regs(child); + xtensa_gregset_t __user *gregset = uregs; + unsigned long wb = regs->windowbase; + int i; + + if (!access_ok(VERIFY_WRITE, uregs, sizeof(xtensa_gregset_t))) + return -EIO; + + __put_user(regs->pc, &gregset->pc); + __put_user(regs->ps & ~(1 << PS_EXCM_BIT), &gregset->ps); + __put_user(regs->lbeg, &gregset->lbeg); + __put_user(regs->lend, &gregset->lend); + __put_user(regs->lcount, &gregset->lcount); + __put_user(regs->windowstart, &gregset->windowstart); + __put_user(regs->windowbase, &gregset->windowbase); + __put_user(regs->threadptr, &gregset->threadptr); + + for (i = 0; i < XCHAL_NUM_AREGS; i++) + __put_user(regs->areg[i], + gregset->a + ((wb * 4 + i) % XCHAL_NUM_AREGS)); + + return 0; +} + +int ptrace_setregs(struct task_struct *child, void __user *uregs) +{ + struct pt_regs *regs = task_pt_regs(child); + xtensa_gregset_t *gregset = uregs; + const unsigned long ps_mask = PS_CALLINC_MASK | PS_OWB_MASK; + unsigned long ps; + unsigned long wb, ws; + + if (!access_ok(VERIFY_WRITE, uregs, sizeof(xtensa_gregset_t))) + return -EIO; + + __get_user(regs->pc, &gregset->pc); + __get_user(ps, &gregset->ps); + __get_user(regs->lbeg, &gregset->lbeg); + __get_user(regs->lend, &gregset->lend); + __get_user(regs->lcount, &gregset->lcount); + __get_user(ws, &gregset->windowstart); + __get_user(wb, &gregset->windowbase); + __get_user(regs->threadptr, &gregset->threadptr); + + regs->ps = (regs->ps & ~ps_mask) | (ps & ps_mask) | (1 << PS_EXCM_BIT); + + if (wb >= XCHAL_NUM_AREGS / 4) + return -EFAULT; + + if (wb != regs->windowbase || ws != regs->windowstart) { + unsigned long rotws, wmask; + + rotws = (((ws | (ws << WSBITS)) >> wb) & + ((1 << WSBITS) - 1)) & ~1; + wmask = ((rotws ? WSBITS + 1 - ffs(rotws) : 0) << 4) | + (rotws & 0xF) | 1; + regs->windowbase = wb; + regs->windowstart = ws; + regs->wmask = wmask; + } + + if (wb != 0 && __copy_from_user(regs->areg + XCHAL_NUM_AREGS - wb * 4, + gregset->a, wb * 16)) + return -EFAULT; + + if (__copy_from_user(regs->areg, gregset->a + wb * 4, + (WSBITS - wb) * 16)) + return -EFAULT; + + return 0; +} + + +int ptrace_getxregs(struct task_struct *child, void __user *uregs) +{ + struct pt_regs *regs = task_pt_regs(child); + struct thread_info *ti = task_thread_info(child); + elf_xtregs_t __user *xtregs = uregs; + int ret = 0; + + if (!access_ok(VERIFY_WRITE, uregs, sizeof(elf_xtregs_t))) + return -EIO; + +#if XTENSA_HAVE_COPROCESSORS + /* Flush all coprocessor registers to memory. */ + coprocessor_flush_all(ti); + ret |= __copy_to_user(&xtregs->cp0, &ti->xtregs_cp, + sizeof(xtregs_coprocessor_t)); +#endif + ret |= __copy_to_user(&xtregs->opt, ®s->xtregs_opt, + sizeof(xtregs->opt)); + ret |= __copy_to_user(&xtregs->user,&ti->xtregs_user, + sizeof(xtregs->user)); + + return ret ? -EFAULT : 0; +} + +int ptrace_setxregs(struct task_struct *child, void __user *uregs) +{ + struct thread_info *ti = task_thread_info(child); + struct pt_regs *regs = task_pt_regs(child); + elf_xtregs_t *xtregs = uregs; + int ret = 0; + + if (!access_ok(VERIFY_READ, uregs, sizeof(elf_xtregs_t))) + return -EFAULT; + +#if XTENSA_HAVE_COPROCESSORS + /* Flush all coprocessors before we overwrite them. */ + coprocessor_flush_all(ti); + coprocessor_release_all(ti); + + ret |= __copy_from_user(&ti->xtregs_cp, &xtregs->cp0, + sizeof(xtregs_coprocessor_t)); +#endif + ret |= __copy_from_user(®s->xtregs_opt, &xtregs->opt, + sizeof(xtregs->opt)); + ret |= __copy_from_user(&ti->xtregs_user, &xtregs->user, + sizeof(xtregs->user)); + + return ret ? -EFAULT : 0; +} + +int ptrace_peekusr(struct task_struct *child, long regno, long __user *ret) +{ + struct pt_regs *regs; + unsigned long tmp; + + regs = task_pt_regs(child); + tmp = 0; /* Default return value. */ + + switch(regno) { + + case REG_AR_BASE ... REG_AR_BASE + XCHAL_NUM_AREGS - 1: + tmp = regs->areg[regno - REG_AR_BASE]; + break; + + case REG_A_BASE ... REG_A_BASE + 15: + tmp = regs->areg[regno - REG_A_BASE]; + break; + + case REG_PC: + tmp = regs->pc; + break; + + case REG_PS: + /* Note: PS.EXCM is not set while user task is running; + * its being set in regs is for exception handling + * convenience. */ + tmp = (regs->ps & ~(1 << PS_EXCM_BIT)); + break; + + case REG_WB: + break; /* tmp = 0 */ + + case REG_WS: + { + unsigned long wb = regs->windowbase; + unsigned long ws = regs->windowstart; + tmp = ((ws>>wb) | (ws<<(WSBITS-wb))) & ((1<<WSBITS)-1); + break; + } + case REG_LBEG: + tmp = regs->lbeg; + break; + + case REG_LEND: + tmp = regs->lend; + break; + + case REG_LCOUNT: + tmp = regs->lcount; + break; + + case REG_SAR: + tmp = regs->sar; + break; + + case SYSCALL_NR: + tmp = regs->syscall; + break; + + default: + return -EIO; + } + return put_user(tmp, ret); +} + +int ptrace_pokeusr(struct task_struct *child, long regno, long val) +{ + struct pt_regs *regs; + regs = task_pt_regs(child); + + switch (regno) { + case REG_AR_BASE ... REG_AR_BASE + XCHAL_NUM_AREGS - 1: + regs->areg[regno - REG_AR_BASE] = val; + break; + + case REG_A_BASE ... REG_A_BASE + 15: + regs->areg[regno - REG_A_BASE] = val; + break; + + case REG_PC: + regs->pc = val; + break; + + case SYSCALL_NR: + regs->syscall = val; + break; + + default: + return -EIO; + } + return 0; +} + +long arch_ptrace(struct task_struct *child, long request, + unsigned long addr, unsigned long data) +{ + int ret = -EPERM; + void __user *datap = (void __user *) data; + + switch (request) { + case PTRACE_PEEKTEXT: /* read word at location addr. */ + case PTRACE_PEEKDATA: + ret = generic_ptrace_peekdata(child, addr, data); + break; + + case PTRACE_PEEKUSR: /* read register specified by addr. */ + ret = ptrace_peekusr(child, addr, datap); + break; + + case PTRACE_POKETEXT: /* write the word at location addr. */ + case PTRACE_POKEDATA: + ret = generic_ptrace_pokedata(child, addr, data); + break; + + case PTRACE_POKEUSR: /* write register specified by addr. */ + ret = ptrace_pokeusr(child, addr, data); + break; + + case PTRACE_GETREGS: + ret = ptrace_getregs(child, datap); + break; + + case PTRACE_SETREGS: + ret = ptrace_setregs(child, datap); + break; + + case PTRACE_GETXTREGS: + ret = ptrace_getxregs(child, datap); + break; + + case PTRACE_SETXTREGS: + ret = ptrace_setxregs(child, datap); + break; + + default: + ret = ptrace_request(child, request, addr, data); + break; + } + + return ret; +} + +void do_syscall_trace(void) +{ + /* + * The 0x80 provides a way for the tracing parent to distinguish + * between a syscall stop and SIGTRAP delivery + */ + ptrace_notify(SIGTRAP|((current->ptrace & PT_TRACESYSGOOD) ? 0x80 : 0)); + + /* + * this isn't the same as continuing with a signal, but it will do + * for normal use. strace only continues with a signal if the + * stopping signal is not SIGTRAP. -brl + */ + if (current->exit_code) { + send_sig(current->exit_code, current, 1); + current->exit_code = 0; + } +} + +void do_syscall_trace_enter(struct pt_regs *regs) +{ + if (test_thread_flag(TIF_SYSCALL_TRACE) + && (current->ptrace & PT_PTRACED)) + do_syscall_trace(); + +#if 0 + audit_syscall_entry(...); +#endif +} + +void do_syscall_trace_leave(struct pt_regs *regs) +{ + if ((test_thread_flag(TIF_SYSCALL_TRACE)) + && (current->ptrace & PT_PTRACED)) + do_syscall_trace(); +} diff --git a/arch/xtensa/kernel/setup.c b/arch/xtensa/kernel/setup.c new file mode 100644 index 000000000..28fc57ef5 --- /dev/null +++ b/arch/xtensa/kernel/setup.c @@ -0,0 +1,728 @@ +/* + * arch/xtensa/kernel/setup.c + * + * This file is subject to the terms and conditions of the GNU General Public + * License. See the file "COPYING" in the main directory of this archive + * for more details. + * + * Copyright (C) 1995 Linus Torvalds + * Copyright (C) 2001 - 2005 Tensilica Inc. + * + * Chris Zankel <chris@zankel.net> + * Joe Taylor <joe@tensilica.com, joetylr@yahoo.com> + * Kevin Chea + * Marc Gauthier<marc@tensilica.com> <marc@alumni.uwaterloo.ca> + */ + +#include <linux/errno.h> +#include <linux/init.h> +#include <linux/mm.h> +#include <linux/proc_fs.h> +#include <linux/screen_info.h> +#include <linux/bootmem.h> +#include <linux/kernel.h> +#include <linux/percpu.h> +#include <linux/clk-provider.h> +#include <linux/cpu.h> +#include <linux/of_fdt.h> +#include <linux/of_platform.h> + +#if defined(CONFIG_VGA_CONSOLE) || defined(CONFIG_DUMMY_CONSOLE) +# include <linux/console.h> +#endif + +#ifdef CONFIG_RTC +# include <linux/timex.h> +#endif + +#ifdef CONFIG_PROC_FS +# include <linux/seq_file.h> +#endif + +#include <asm/bootparam.h> +#include <asm/mmu_context.h> +#include <asm/pgtable.h> +#include <asm/processor.h> +#include <asm/timex.h> +#include <asm/platform.h> +#include <asm/page.h> +#include <asm/setup.h> +#include <asm/param.h> +#include <asm/traps.h> +#include <asm/smp.h> +#include <asm/sysmem.h> + +#include <platform/hardware.h> + +#if defined(CONFIG_VGA_CONSOLE) || defined(CONFIG_DUMMY_CONSOLE) +struct screen_info screen_info = { 0, 24, 0, 0, 0, 80, 0, 0, 0, 24, 1, 16}; +#endif + +#ifdef CONFIG_BLK_DEV_FD +extern struct fd_ops no_fd_ops; +struct fd_ops *fd_ops; +#endif + +extern struct rtc_ops no_rtc_ops; +struct rtc_ops *rtc_ops; + +#ifdef CONFIG_BLK_DEV_INITRD +extern unsigned long initrd_start; +extern unsigned long initrd_end; +int initrd_is_mapped = 0; +extern int initrd_below_start_ok; +#endif + +#ifdef CONFIG_OF +void *dtb_start = __dtb_start; +#endif + +unsigned char aux_device_present; +extern unsigned long loops_per_jiffy; + +/* Command line specified as configuration option. */ + +static char __initdata command_line[COMMAND_LINE_SIZE]; + +#ifdef CONFIG_CMDLINE_BOOL +static char default_command_line[COMMAND_LINE_SIZE] __initdata = CONFIG_CMDLINE; +#endif + +/* + * Boot parameter parsing. + * + * The Xtensa port uses a list of variable-sized tags to pass data to + * the kernel. The first tag must be a BP_TAG_FIRST tag for the list + * to be recognised. The list is terminated with a zero-sized + * BP_TAG_LAST tag. + */ + +typedef struct tagtable { + u32 tag; + int (*parse)(const bp_tag_t*); +} tagtable_t; + +#define __tagtable(tag, fn) static tagtable_t __tagtable_##fn \ + __attribute__((used, section(".taglist"))) = { tag, fn } + +/* parse current tag */ + +static int __init parse_tag_mem(const bp_tag_t *tag) +{ + struct bp_meminfo *mi = (struct bp_meminfo *)(tag->data); + + if (mi->type != MEMORY_TYPE_CONVENTIONAL) + return -1; + + return add_sysmem_bank(mi->start, mi->end); +} + +__tagtable(BP_TAG_MEMORY, parse_tag_mem); + +#ifdef CONFIG_BLK_DEV_INITRD + +static int __init parse_tag_initrd(const bp_tag_t* tag) +{ + struct bp_meminfo *mi = (struct bp_meminfo *)(tag->data); + + initrd_start = (unsigned long)__va(mi->start); + initrd_end = (unsigned long)__va(mi->end); + + return 0; +} + +__tagtable(BP_TAG_INITRD, parse_tag_initrd); + +#ifdef CONFIG_OF + +static int __init parse_tag_fdt(const bp_tag_t *tag) +{ + dtb_start = __va(tag->data[0]); + return 0; +} + +__tagtable(BP_TAG_FDT, parse_tag_fdt); + +#endif /* CONFIG_OF */ + +#endif /* CONFIG_BLK_DEV_INITRD */ + +static int __init parse_tag_cmdline(const bp_tag_t* tag) +{ + strlcpy(command_line, (char *)(tag->data), COMMAND_LINE_SIZE); + return 0; +} + +__tagtable(BP_TAG_COMMAND_LINE, parse_tag_cmdline); + +static int __init parse_bootparam(const bp_tag_t* tag) +{ + extern tagtable_t __tagtable_begin, __tagtable_end; + tagtable_t *t; + + /* Boot parameters must start with a BP_TAG_FIRST tag. */ + + if (tag->id != BP_TAG_FIRST) { + printk(KERN_WARNING "Invalid boot parameters!\n"); + return 0; + } + + tag = (bp_tag_t*)((unsigned long)tag + sizeof(bp_tag_t) + tag->size); + + /* Parse all tags. */ + + while (tag != NULL && tag->id != BP_TAG_LAST) { + for (t = &__tagtable_begin; t < &__tagtable_end; t++) { + if (tag->id == t->tag) { + t->parse(tag); + break; + } + } + if (t == &__tagtable_end) + printk(KERN_WARNING "Ignoring tag " + "0x%08x\n", tag->id); + tag = (bp_tag_t*)((unsigned long)(tag + 1) + tag->size); + } + + return 0; +} + +#ifdef CONFIG_OF +bool __initdata dt_memory_scan = false; + +#if XCHAL_HAVE_PTP_MMU && XCHAL_HAVE_SPANNING_WAY +unsigned long xtensa_kio_paddr = XCHAL_KIO_DEFAULT_PADDR; +EXPORT_SYMBOL(xtensa_kio_paddr); + +static int __init xtensa_dt_io_area(unsigned long node, const char *uname, + int depth, void *data) +{ + const __be32 *ranges; + int len; + + if (depth > 1) + return 0; + + if (!of_flat_dt_is_compatible(node, "simple-bus")) + return 0; + + ranges = of_get_flat_dt_prop(node, "ranges", &len); + if (!ranges) + return 1; + if (len == 0) + return 1; + + xtensa_kio_paddr = of_read_ulong(ranges+1, 1); + /* round down to nearest 256MB boundary */ + xtensa_kio_paddr &= 0xf0000000; + + return 1; +} +#else +static int __init xtensa_dt_io_area(unsigned long node, const char *uname, + int depth, void *data) +{ + return 1; +} +#endif + +void __init early_init_dt_add_memory_arch(u64 base, u64 size) +{ + if (!dt_memory_scan) + return; + + size &= PAGE_MASK; + add_sysmem_bank(base, base + size); +} + +void * __init early_init_dt_alloc_memory_arch(u64 size, u64 align) +{ + return __alloc_bootmem(size, align, 0); +} + +void __init early_init_devtree(void *params) +{ + if (sysmem.nr_banks == 0) + dt_memory_scan = true; + + early_init_dt_scan(params); + of_scan_flat_dt(xtensa_dt_io_area, NULL); + + if (!command_line[0]) + strlcpy(command_line, boot_command_line, COMMAND_LINE_SIZE); +} + +static int __init xtensa_device_probe(void) +{ + of_clk_init(NULL); + of_platform_populate(NULL, of_default_bus_match_table, NULL, NULL); + return 0; +} + +device_initcall(xtensa_device_probe); + +#endif /* CONFIG_OF */ + +/* + * Initialize architecture. (Early stage) + */ + +void __init init_arch(bp_tag_t *bp_start) +{ + /* Parse boot parameters */ + + if (bp_start) + parse_bootparam(bp_start); + +#ifdef CONFIG_OF + early_init_devtree(dtb_start); +#endif + + if (sysmem.nr_banks == 0) { + add_sysmem_bank(PLATFORM_DEFAULT_MEM_START, + PLATFORM_DEFAULT_MEM_START + + PLATFORM_DEFAULT_MEM_SIZE); + } + +#ifdef CONFIG_CMDLINE_BOOL + if (!command_line[0]) + strlcpy(command_line, default_command_line, COMMAND_LINE_SIZE); +#endif + + /* Early hook for platforms */ + + platform_init(bp_start); + + /* Initialize MMU. */ + + init_mmu(); +} + +/* + * Initialize system. Setup memory and reserve regions. + */ + +extern char _end; +extern char _stext; +extern char _WindowVectors_text_start; +extern char _WindowVectors_text_end; +extern char _DebugInterruptVector_literal_start; +extern char _DebugInterruptVector_text_end; +extern char _KernelExceptionVector_literal_start; +extern char _KernelExceptionVector_text_end; +extern char _UserExceptionVector_literal_start; +extern char _UserExceptionVector_text_end; +extern char _DoubleExceptionVector_literal_start; +extern char _DoubleExceptionVector_text_end; +#if XCHAL_EXCM_LEVEL >= 2 +extern char _Level2InterruptVector_text_start; +extern char _Level2InterruptVector_text_end; +#endif +#if XCHAL_EXCM_LEVEL >= 3 +extern char _Level3InterruptVector_text_start; +extern char _Level3InterruptVector_text_end; +#endif +#if XCHAL_EXCM_LEVEL >= 4 +extern char _Level4InterruptVector_text_start; +extern char _Level4InterruptVector_text_end; +#endif +#if XCHAL_EXCM_LEVEL >= 5 +extern char _Level5InterruptVector_text_start; +extern char _Level5InterruptVector_text_end; +#endif +#if XCHAL_EXCM_LEVEL >= 6 +extern char _Level6InterruptVector_text_start; +extern char _Level6InterruptVector_text_end; +#endif + + + +#ifdef CONFIG_S32C1I_SELFTEST +#if XCHAL_HAVE_S32C1I + +static int __initdata rcw_word, rcw_probe_pc, rcw_exc; + +/* + * Basic atomic compare-and-swap, that records PC of S32C1I for probing. + * + * If *v == cmp, set *v = set. Return previous *v. + */ +static inline int probed_compare_swap(int *v, int cmp, int set) +{ + int tmp; + + __asm__ __volatile__( + " movi %1, 1f\n" + " s32i %1, %4, 0\n" + " wsr %2, scompare1\n" + "1: s32c1i %0, %3, 0\n" + : "=a" (set), "=&a" (tmp) + : "a" (cmp), "a" (v), "a" (&rcw_probe_pc), "0" (set) + : "memory" + ); + return set; +} + +/* Handle probed exception */ + +static void __init do_probed_exception(struct pt_regs *regs, + unsigned long exccause) +{ + if (regs->pc == rcw_probe_pc) { /* exception on s32c1i ? */ + regs->pc += 3; /* skip the s32c1i instruction */ + rcw_exc = exccause; + } else { + do_unhandled(regs, exccause); + } +} + +/* Simple test of S32C1I (soc bringup assist) */ + +static int __init check_s32c1i(void) +{ + int n, cause1, cause2; + void *handbus, *handdata, *handaddr; /* temporarily saved handlers */ + + rcw_probe_pc = 0; + handbus = trap_set_handler(EXCCAUSE_LOAD_STORE_ERROR, + do_probed_exception); + handdata = trap_set_handler(EXCCAUSE_LOAD_STORE_DATA_ERROR, + do_probed_exception); + handaddr = trap_set_handler(EXCCAUSE_LOAD_STORE_ADDR_ERROR, + do_probed_exception); + + /* First try an S32C1I that does not store: */ + rcw_exc = 0; + rcw_word = 1; + n = probed_compare_swap(&rcw_word, 0, 2); + cause1 = rcw_exc; + + /* took exception? */ + if (cause1 != 0) { + /* unclean exception? */ + if (n != 2 || rcw_word != 1) + panic("S32C1I exception error"); + } else if (rcw_word != 1 || n != 1) { + panic("S32C1I compare error"); + } + + /* Then an S32C1I that stores: */ + rcw_exc = 0; + rcw_word = 0x1234567; + n = probed_compare_swap(&rcw_word, 0x1234567, 0xabcde); + cause2 = rcw_exc; + + if (cause2 != 0) { + /* unclean exception? */ + if (n != 0xabcde || rcw_word != 0x1234567) + panic("S32C1I exception error (b)"); + } else if (rcw_word != 0xabcde || n != 0x1234567) { + panic("S32C1I store error"); + } + + /* Verify consistency of exceptions: */ + if (cause1 || cause2) { + pr_warn("S32C1I took exception %d, %d\n", cause1, cause2); + /* If emulation of S32C1I upon bus error gets implemented, + we can get rid of this panic for single core (not SMP) */ + panic("S32C1I exceptions not currently supported"); + } + if (cause1 != cause2) + panic("inconsistent S32C1I exceptions"); + + trap_set_handler(EXCCAUSE_LOAD_STORE_ERROR, handbus); + trap_set_handler(EXCCAUSE_LOAD_STORE_DATA_ERROR, handdata); + trap_set_handler(EXCCAUSE_LOAD_STORE_ADDR_ERROR, handaddr); + return 0; +} + +#else /* XCHAL_HAVE_S32C1I */ + +/* This condition should not occur with a commercially deployed processor. + Display reminder for early engr test or demo chips / FPGA bitstreams */ +static int __init check_s32c1i(void) +{ + pr_warn("Processor configuration lacks atomic compare-and-swap support!\n"); + return 0; +} + +#endif /* XCHAL_HAVE_S32C1I */ +early_initcall(check_s32c1i); +#endif /* CONFIG_S32C1I_SELFTEST */ + + +void __init setup_arch(char **cmdline_p) +{ + strlcpy(boot_command_line, command_line, COMMAND_LINE_SIZE); + *cmdline_p = command_line; + + /* Reserve some memory regions */ + +#ifdef CONFIG_BLK_DEV_INITRD + if (initrd_start < initrd_end) { + initrd_is_mapped = mem_reserve(__pa(initrd_start), + __pa(initrd_end), 0) == 0; + initrd_below_start_ok = 1; + } else { + initrd_start = 0; + } +#endif + + mem_reserve(__pa(&_stext),__pa(&_end), 1); + + mem_reserve(__pa(&_WindowVectors_text_start), + __pa(&_WindowVectors_text_end), 0); + + mem_reserve(__pa(&_DebugInterruptVector_literal_start), + __pa(&_DebugInterruptVector_text_end), 0); + + mem_reserve(__pa(&_KernelExceptionVector_literal_start), + __pa(&_KernelExceptionVector_text_end), 0); + + mem_reserve(__pa(&_UserExceptionVector_literal_start), + __pa(&_UserExceptionVector_text_end), 0); + + mem_reserve(__pa(&_DoubleExceptionVector_literal_start), + __pa(&_DoubleExceptionVector_text_end), 0); + +#if XCHAL_EXCM_LEVEL >= 2 + mem_reserve(__pa(&_Level2InterruptVector_text_start), + __pa(&_Level2InterruptVector_text_end), 0); +#endif +#if XCHAL_EXCM_LEVEL >= 3 + mem_reserve(__pa(&_Level3InterruptVector_text_start), + __pa(&_Level3InterruptVector_text_end), 0); +#endif +#if XCHAL_EXCM_LEVEL >= 4 + mem_reserve(__pa(&_Level4InterruptVector_text_start), + __pa(&_Level4InterruptVector_text_end), 0); +#endif +#if XCHAL_EXCM_LEVEL >= 5 + mem_reserve(__pa(&_Level5InterruptVector_text_start), + __pa(&_Level5InterruptVector_text_end), 0); +#endif +#if XCHAL_EXCM_LEVEL >= 6 + mem_reserve(__pa(&_Level6InterruptVector_text_start), + __pa(&_Level6InterruptVector_text_end), 0); +#endif + + parse_early_param(); + bootmem_init(); + + unflatten_and_copy_device_tree(); + + platform_setup(cmdline_p); + +#ifdef CONFIG_SMP + smp_init_cpus(); +#endif + + paging_init(); + zones_init(); + +#ifdef CONFIG_VT +# if defined(CONFIG_VGA_CONSOLE) + conswitchp = &vga_con; +# elif defined(CONFIG_DUMMY_CONSOLE) + conswitchp = &dummy_con; +# endif +#endif + +#ifdef CONFIG_PCI + platform_pcibios_init(); +#endif +} + +static DEFINE_PER_CPU(struct cpu, cpu_data); + +static int __init topology_init(void) +{ + int i; + + for_each_possible_cpu(i) { + struct cpu *cpu = &per_cpu(cpu_data, i); + cpu->hotpluggable = !!i; + register_cpu(cpu, i); + } + + return 0; +} +subsys_initcall(topology_init); + +void machine_restart(char * cmd) +{ + platform_restart(); +} + +void machine_halt(void) +{ + platform_halt(); + while (1); +} + +void machine_power_off(void) +{ + platform_power_off(); + while (1); +} +#ifdef CONFIG_PROC_FS + +/* + * Display some core information through /proc/cpuinfo. + */ + +static int +c_show(struct seq_file *f, void *slot) +{ + /* high-level stuff */ + seq_printf(f, "CPU count\t: %u\n" + "CPU list\t: %*pbl\n" + "vendor_id\t: Tensilica\n" + "model\t\t: Xtensa " XCHAL_HW_VERSION_NAME "\n" + "core ID\t\t: " XCHAL_CORE_ID "\n" + "build ID\t: 0x%x\n" + "byte order\t: %s\n" + "cpu MHz\t\t: %lu.%02lu\n" + "bogomips\t: %lu.%02lu\n", + num_online_cpus(), + cpumask_pr_args(cpu_online_mask), + XCHAL_BUILD_UNIQUE_ID, + XCHAL_HAVE_BE ? "big" : "little", + ccount_freq/1000000, + (ccount_freq/10000) % 100, + loops_per_jiffy/(500000/HZ), + (loops_per_jiffy/(5000/HZ)) % 100); + + seq_printf(f,"flags\t\t: " +#if XCHAL_HAVE_NMI + "nmi " +#endif +#if XCHAL_HAVE_DEBUG + "debug " +# if XCHAL_HAVE_OCD + "ocd " +# endif +#endif +#if XCHAL_HAVE_DENSITY + "density " +#endif +#if XCHAL_HAVE_BOOLEANS + "boolean " +#endif +#if XCHAL_HAVE_LOOPS + "loop " +#endif +#if XCHAL_HAVE_NSA + "nsa " +#endif +#if XCHAL_HAVE_MINMAX + "minmax " +#endif +#if XCHAL_HAVE_SEXT + "sext " +#endif +#if XCHAL_HAVE_CLAMPS + "clamps " +#endif +#if XCHAL_HAVE_MAC16 + "mac16 " +#endif +#if XCHAL_HAVE_MUL16 + "mul16 " +#endif +#if XCHAL_HAVE_MUL32 + "mul32 " +#endif +#if XCHAL_HAVE_MUL32_HIGH + "mul32h " +#endif +#if XCHAL_HAVE_FP + "fpu " +#endif +#if XCHAL_HAVE_S32C1I + "s32c1i " +#endif + "\n"); + + /* Registers. */ + seq_printf(f,"physical aregs\t: %d\n" + "misc regs\t: %d\n" + "ibreak\t\t: %d\n" + "dbreak\t\t: %d\n", + XCHAL_NUM_AREGS, + XCHAL_NUM_MISC_REGS, + XCHAL_NUM_IBREAK, + XCHAL_NUM_DBREAK); + + + /* Interrupt. */ + seq_printf(f,"num ints\t: %d\n" + "ext ints\t: %d\n" + "int levels\t: %d\n" + "timers\t\t: %d\n" + "debug level\t: %d\n", + XCHAL_NUM_INTERRUPTS, + XCHAL_NUM_EXTINTERRUPTS, + XCHAL_NUM_INTLEVELS, + XCHAL_NUM_TIMERS, + XCHAL_DEBUGLEVEL); + + /* Cache */ + seq_printf(f,"icache line size: %d\n" + "icache ways\t: %d\n" + "icache size\t: %d\n" + "icache flags\t: " +#if XCHAL_ICACHE_LINE_LOCKABLE + "lock " +#endif + "\n" + "dcache line size: %d\n" + "dcache ways\t: %d\n" + "dcache size\t: %d\n" + "dcache flags\t: " +#if XCHAL_DCACHE_IS_WRITEBACK + "writeback " +#endif +#if XCHAL_DCACHE_LINE_LOCKABLE + "lock " +#endif + "\n", + XCHAL_ICACHE_LINESIZE, + XCHAL_ICACHE_WAYS, + XCHAL_ICACHE_SIZE, + XCHAL_DCACHE_LINESIZE, + XCHAL_DCACHE_WAYS, + XCHAL_DCACHE_SIZE); + + return 0; +} + +/* + * We show only CPU #0 info. + */ +static void * +c_start(struct seq_file *f, loff_t *pos) +{ + return (*pos == 0) ? (void *)1 : NULL; +} + +static void * +c_next(struct seq_file *f, void *v, loff_t *pos) +{ + return NULL; +} + +static void +c_stop(struct seq_file *f, void *v) +{ +} + +const struct seq_operations cpuinfo_op = +{ + .start = c_start, + .next = c_next, + .stop = c_stop, + .show = c_show, +}; + +#endif /* CONFIG_PROC_FS */ diff --git a/arch/xtensa/kernel/signal.c b/arch/xtensa/kernel/signal.c new file mode 100644 index 000000000..e87adaa07 --- /dev/null +++ b/arch/xtensa/kernel/signal.c @@ -0,0 +1,499 @@ +/* + * arch/xtensa/kernel/signal.c + * + * Default platform functions. + * + * This file is subject to the terms and conditions of the GNU General Public + * License. See the file "COPYING" in the main directory of this archive + * for more details. + * + * Copyright (C) 2005, 2006 Tensilica Inc. + * Copyright (C) 1991, 1992 Linus Torvalds + * 1997-11-28 Modified for POSIX.1b signals by Richard Henderson + * + * Chris Zankel <chris@zankel.net> + * Joe Taylor <joe@tensilica.com> + */ + +#include <linux/signal.h> +#include <linux/errno.h> +#include <linux/ptrace.h> +#include <linux/personality.h> +#include <linux/tracehook.h> + +#include <asm/ucontext.h> +#include <asm/uaccess.h> +#include <asm/cacheflush.h> +#include <asm/coprocessor.h> +#include <asm/unistd.h> + +#define DEBUG_SIG 0 + +extern struct task_struct *coproc_owners[]; + +struct rt_sigframe +{ + struct siginfo info; + struct ucontext uc; + struct { + xtregs_opt_t opt; + xtregs_user_t user; +#if XTENSA_HAVE_COPROCESSORS + xtregs_coprocessor_t cp; +#endif + } xtregs; + unsigned char retcode[6]; + unsigned int window[4]; +}; + +/* + * Flush register windows stored in pt_regs to stack. + * Returns 1 for errors. + */ + +int +flush_window_regs_user(struct pt_regs *regs) +{ + const unsigned long ws = regs->windowstart; + const unsigned long wb = regs->windowbase; + unsigned long sp = 0; + unsigned long wm; + int err = 1; + int base; + + /* Return if no other frames. */ + + if (regs->wmask == 1) + return 0; + + /* Rotate windowmask and skip empty frames. */ + + wm = (ws >> wb) | (ws << (XCHAL_NUM_AREGS / 4 - wb)); + base = (XCHAL_NUM_AREGS / 4) - (regs->wmask >> 4); + + /* For call8 or call12 frames, we need the previous stack pointer. */ + + if ((regs->wmask & 2) == 0) + if (__get_user(sp, (int*)(regs->areg[base * 4 + 1] - 12))) + goto errout; + + /* Spill frames to stack. */ + + while (base < XCHAL_NUM_AREGS / 4) { + + int m = (wm >> base); + int inc = 0; + + /* Save registers a4..a7 (call8) or a4...a11 (call12) */ + + if (m & 2) { /* call4 */ + inc = 1; + + } else if (m & 4) { /* call8 */ + if (copy_to_user((void*)(sp - 32), + ®s->areg[(base + 1) * 4], 16)) + goto errout; + inc = 2; + + } else if (m & 8) { /* call12 */ + if (copy_to_user((void*)(sp - 48), + ®s->areg[(base + 1) * 4], 32)) + goto errout; + inc = 3; + } + + /* Save current frame a0..a3 under next SP */ + + sp = regs->areg[((base + inc) * 4 + 1) % XCHAL_NUM_AREGS]; + if (copy_to_user((void*)(sp - 16), ®s->areg[base * 4], 16)) + goto errout; + + /* Get current stack pointer for next loop iteration. */ + + sp = regs->areg[base * 4 + 1]; + base += inc; + } + + regs->wmask = 1; + regs->windowstart = 1 << wb; + + return 0; + +errout: + return err; +} + +/* + * Note: We don't copy double exception 'regs', we have to finish double exc. + * first before we return to signal handler! This dbl.exc.handler might cause + * another double exception, but I think we are fine as the situation is the + * same as if we had returned to the signal handerl and got an interrupt + * immediately... + */ + +static int +setup_sigcontext(struct rt_sigframe __user *frame, struct pt_regs *regs) +{ + struct sigcontext __user *sc = &frame->uc.uc_mcontext; + struct thread_info *ti = current_thread_info(); + int err = 0; + +#define COPY(x) err |= __put_user(regs->x, &sc->sc_##x) + COPY(pc); + COPY(ps); + COPY(lbeg); + COPY(lend); + COPY(lcount); + COPY(sar); +#undef COPY + + err |= flush_window_regs_user(regs); + err |= __copy_to_user (sc->sc_a, regs->areg, 16 * 4); + err |= __put_user(0, &sc->sc_xtregs); + + if (err) + return err; + +#if XTENSA_HAVE_COPROCESSORS + coprocessor_flush_all(ti); + coprocessor_release_all(ti); + err |= __copy_to_user(&frame->xtregs.cp, &ti->xtregs_cp, + sizeof (frame->xtregs.cp)); +#endif + err |= __copy_to_user(&frame->xtregs.opt, ®s->xtregs_opt, + sizeof (xtregs_opt_t)); + err |= __copy_to_user(&frame->xtregs.user, &ti->xtregs_user, + sizeof (xtregs_user_t)); + + err |= __put_user(err ? NULL : &frame->xtregs, &sc->sc_xtregs); + + return err; +} + +static int +restore_sigcontext(struct pt_regs *regs, struct rt_sigframe __user *frame) +{ + struct sigcontext __user *sc = &frame->uc.uc_mcontext; + struct thread_info *ti = current_thread_info(); + unsigned int err = 0; + unsigned long ps; + +#define COPY(x) err |= __get_user(regs->x, &sc->sc_##x) + COPY(pc); + COPY(lbeg); + COPY(lend); + COPY(lcount); + COPY(sar); +#undef COPY + + /* All registers were flushed to stack. Start with a prestine frame. */ + + regs->wmask = 1; + regs->windowbase = 0; + regs->windowstart = 1; + + regs->syscall = -1; /* disable syscall checks */ + + /* For PS, restore only PS.CALLINC. + * Assume that all other bits are either the same as for the signal + * handler, or the user mode value doesn't matter (e.g. PS.OWB). + */ + err |= __get_user(ps, &sc->sc_ps); + regs->ps = (regs->ps & ~PS_CALLINC_MASK) | (ps & PS_CALLINC_MASK); + + /* Additional corruption checks */ + + if ((regs->lcount > 0) + && ((regs->lbeg > TASK_SIZE) || (regs->lend > TASK_SIZE)) ) + err = 1; + + err |= __copy_from_user(regs->areg, sc->sc_a, 16 * 4); + + if (err) + return err; + + /* The signal handler may have used coprocessors in which + * case they are still enabled. We disable them to force a + * reloading of the original task's CP state by the lazy + * context-switching mechanisms of CP exception handling. + * Also, we essentially discard any coprocessor state that the + * signal handler created. */ + +#if XTENSA_HAVE_COPROCESSORS + coprocessor_release_all(ti); + err |= __copy_from_user(&ti->xtregs_cp, &frame->xtregs.cp, + sizeof (frame->xtregs.cp)); +#endif + err |= __copy_from_user(&ti->xtregs_user, &frame->xtregs.user, + sizeof (xtregs_user_t)); + err |= __copy_from_user(®s->xtregs_opt, &frame->xtregs.opt, + sizeof (xtregs_opt_t)); + + return err; +} + + +/* + * Do a signal return; undo the signal stack. + */ + +asmlinkage long xtensa_rt_sigreturn(long a0, long a1, long a2, long a3, + long a4, long a5, struct pt_regs *regs) +{ + struct rt_sigframe __user *frame; + sigset_t set; + int ret; + + /* Always make any pending restarted system calls return -EINTR */ + current->restart_block.fn = do_no_restart_syscall; + + if (regs->depc > 64) + panic("rt_sigreturn in double exception!\n"); + + frame = (struct rt_sigframe __user *) regs->areg[1]; + + if (!access_ok(VERIFY_READ, frame, sizeof(*frame))) + goto badframe; + + if (__copy_from_user(&set, &frame->uc.uc_sigmask, sizeof(set))) + goto badframe; + + set_current_blocked(&set); + + if (restore_sigcontext(regs, frame)) + goto badframe; + + ret = regs->areg[2]; + + if (restore_altstack(&frame->uc.uc_stack)) + goto badframe; + + return ret; + +badframe: + force_sig(SIGSEGV, current); + return 0; +} + + + +/* + * Set up a signal frame. + */ + +static int +gen_return_code(unsigned char *codemem) +{ + int err = 0; + + /* + * The 12-bit immediate is really split up within the 24-bit MOVI + * instruction. As long as the above system call numbers fit within + * 8-bits, the following code works fine. See the Xtensa ISA for + * details. + */ + +#if __NR_rt_sigreturn > 255 +# error Generating the MOVI instruction below breaks! +#endif + +#ifdef __XTENSA_EB__ /* Big Endian version */ + /* Generate instruction: MOVI a2, __NR_rt_sigreturn */ + err |= __put_user(0x22, &codemem[0]); + err |= __put_user(0x0a, &codemem[1]); + err |= __put_user(__NR_rt_sigreturn, &codemem[2]); + /* Generate instruction: SYSCALL */ + err |= __put_user(0x00, &codemem[3]); + err |= __put_user(0x05, &codemem[4]); + err |= __put_user(0x00, &codemem[5]); + +#elif defined __XTENSA_EL__ /* Little Endian version */ + /* Generate instruction: MOVI a2, __NR_rt_sigreturn */ + err |= __put_user(0x22, &codemem[0]); + err |= __put_user(0xa0, &codemem[1]); + err |= __put_user(__NR_rt_sigreturn, &codemem[2]); + /* Generate instruction: SYSCALL */ + err |= __put_user(0x00, &codemem[3]); + err |= __put_user(0x50, &codemem[4]); + err |= __put_user(0x00, &codemem[5]); +#else +# error Must use compiler for Xtensa processors. +#endif + + /* Flush generated code out of the data cache */ + + if (err == 0) { + __invalidate_icache_range((unsigned long)codemem, 6UL); + __flush_invalidate_dcache_range((unsigned long)codemem, 6UL); + } + + return err; +} + + +static int setup_frame(struct ksignal *ksig, sigset_t *set, + struct pt_regs *regs) +{ + struct rt_sigframe *frame; + int err = 0, sig = ksig->sig; + unsigned long sp, ra, tp; + + sp = regs->areg[1]; + + if ((ksig->ka.sa.sa_flags & SA_ONSTACK) != 0 && sas_ss_flags(sp) == 0) { + sp = current->sas_ss_sp + current->sas_ss_size; + } + + frame = (void *)((sp - sizeof(*frame)) & -16ul); + + if (regs->depc > 64) + panic ("Double exception sys_sigreturn\n"); + + if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame))) { + return -EFAULT; + } + + if (ksig->ka.sa.sa_flags & SA_SIGINFO) { + err |= copy_siginfo_to_user(&frame->info, &ksig->info); + } + + /* Create the user context. */ + + err |= __put_user(0, &frame->uc.uc_flags); + err |= __put_user(0, &frame->uc.uc_link); + err |= __save_altstack(&frame->uc.uc_stack, regs->areg[1]); + err |= setup_sigcontext(frame, regs); + err |= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set)); + + if (ksig->ka.sa.sa_flags & SA_RESTORER) { + ra = (unsigned long)ksig->ka.sa.sa_restorer; + } else { + + /* Create sys_rt_sigreturn syscall in stack frame */ + + err |= gen_return_code(frame->retcode); + + if (err) { + return -EFAULT; + } + ra = (unsigned long) frame->retcode; + } + + /* + * Create signal handler execution context. + * Return context not modified until this point. + */ + + /* Set up registers for signal handler; preserve the threadptr */ + tp = regs->threadptr; + start_thread(regs, (unsigned long) ksig->ka.sa.sa_handler, + (unsigned long) frame); + + /* Set up a stack frame for a call4 + * Note: PS.CALLINC is set to one by start_thread + */ + regs->areg[4] = (((unsigned long) ra) & 0x3fffffff) | 0x40000000; + regs->areg[6] = (unsigned long) sig; + regs->areg[7] = (unsigned long) &frame->info; + regs->areg[8] = (unsigned long) &frame->uc; + regs->threadptr = tp; + +#if DEBUG_SIG + printk("SIG rt deliver (%s:%d): signal=%d sp=%p pc=%08x\n", + current->comm, current->pid, sig, frame, regs->pc); +#endif + + return 0; +} + +/* + * Note that 'init' is a special process: it doesn't get signals it doesn't + * want to handle. Thus you cannot kill init even with a SIGKILL even by + * mistake. + * + * Note that we go through the signals twice: once to check the signals that + * the kernel can handle, and then we build all the user-level signal handling + * stack-frames in one go after that. + */ +static void do_signal(struct pt_regs *regs) +{ + struct ksignal ksig; + + task_pt_regs(current)->icountlevel = 0; + + if (get_signal(&ksig)) { + int ret; + + /* Are we from a system call? */ + + if ((signed)regs->syscall >= 0) { + + /* If so, check system call restarting.. */ + + switch (regs->areg[2]) { + case -ERESTARTNOHAND: + case -ERESTART_RESTARTBLOCK: + regs->areg[2] = -EINTR; + break; + + case -ERESTARTSYS: + if (!(ksig.ka.sa.sa_flags & SA_RESTART)) { + regs->areg[2] = -EINTR; + break; + } + /* fallthrough */ + case -ERESTARTNOINTR: + regs->areg[2] = regs->syscall; + regs->pc -= 3; + break; + + default: + /* nothing to do */ + if (regs->areg[2] != 0) + break; + } + } + + /* Whee! Actually deliver the signal. */ + /* Set up the stack frame */ + ret = setup_frame(&ksig, sigmask_to_save(), regs); + signal_setup_done(ret, &ksig, 0); + if (current->ptrace & PT_SINGLESTEP) + task_pt_regs(current)->icountlevel = 1; + + return; + } + + /* Did we come from a system call? */ + if ((signed) regs->syscall >= 0) { + /* Restart the system call - no handlers present */ + switch (regs->areg[2]) { + case -ERESTARTNOHAND: + case -ERESTARTSYS: + case -ERESTARTNOINTR: + regs->areg[2] = regs->syscall; + regs->pc -= 3; + break; + case -ERESTART_RESTARTBLOCK: + regs->areg[2] = __NR_restart_syscall; + regs->pc -= 3; + break; + } + } + + /* If there's no signal to deliver, we just restore the saved mask. */ + restore_saved_sigmask(); + + if (current->ptrace & PT_SINGLESTEP) + task_pt_regs(current)->icountlevel = 1; + return; +} + +void do_notify_resume(struct pt_regs *regs) +{ + if (test_thread_flag(TIF_SIGPENDING)) + do_signal(regs); + + if (test_and_clear_thread_flag(TIF_NOTIFY_RESUME)) + tracehook_notify_resume(regs); +} diff --git a/arch/xtensa/kernel/smp.c b/arch/xtensa/kernel/smp.c new file mode 100644 index 000000000..4d02e3851 --- /dev/null +++ b/arch/xtensa/kernel/smp.c @@ -0,0 +1,608 @@ +/* + * Xtensa SMP support functions. + * + * This file is subject to the terms and conditions of the GNU General Public + * License. See the file "COPYING" in the main directory of this archive + * for more details. + * + * Copyright (C) 2008 - 2013 Tensilica Inc. + * + * Chris Zankel <chris@zankel.net> + * Joe Taylor <joe@tensilica.com> + * Pete Delaney <piet@tensilica.com + */ + +#include <linux/cpu.h> +#include <linux/cpumask.h> +#include <linux/delay.h> +#include <linux/init.h> +#include <linux/interrupt.h> +#include <linux/irqdomain.h> +#include <linux/irq.h> +#include <linux/kdebug.h> +#include <linux/module.h> +#include <linux/reboot.h> +#include <linux/seq_file.h> +#include <linux/smp.h> +#include <linux/thread_info.h> + +#include <asm/cacheflush.h> +#include <asm/kdebug.h> +#include <asm/mmu_context.h> +#include <asm/mxregs.h> +#include <asm/platform.h> +#include <asm/tlbflush.h> +#include <asm/traps.h> + +#ifdef CONFIG_SMP +# if XCHAL_HAVE_S32C1I == 0 +# error "The S32C1I option is required for SMP." +# endif +#endif + +static void system_invalidate_dcache_range(unsigned long start, + unsigned long size); +static void system_flush_invalidate_dcache_range(unsigned long start, + unsigned long size); + +/* IPI (Inter Process Interrupt) */ + +#define IPI_IRQ 0 + +static irqreturn_t ipi_interrupt(int irq, void *dev_id); +static struct irqaction ipi_irqaction = { + .handler = ipi_interrupt, + .flags = IRQF_PERCPU, + .name = "ipi", +}; + +void ipi_init(void) +{ + unsigned irq = irq_create_mapping(NULL, IPI_IRQ); + setup_irq(irq, &ipi_irqaction); +} + +static inline unsigned int get_core_count(void) +{ + /* Bits 18..21 of SYSCFGID contain the core count minus 1. */ + unsigned int syscfgid = get_er(SYSCFGID); + return ((syscfgid >> 18) & 0xf) + 1; +} + +static inline int get_core_id(void) +{ + /* Bits 0...18 of SYSCFGID contain the core id */ + unsigned int core_id = get_er(SYSCFGID); + return core_id & 0x3fff; +} + +void __init smp_prepare_cpus(unsigned int max_cpus) +{ + unsigned i; + + for (i = 0; i < max_cpus; ++i) + set_cpu_present(i, true); +} + +void __init smp_init_cpus(void) +{ + unsigned i; + unsigned int ncpus = get_core_count(); + unsigned int core_id = get_core_id(); + + pr_info("%s: Core Count = %d\n", __func__, ncpus); + pr_info("%s: Core Id = %d\n", __func__, core_id); + + for (i = 0; i < ncpus; ++i) + set_cpu_possible(i, true); +} + +void __init smp_prepare_boot_cpu(void) +{ + unsigned int cpu = smp_processor_id(); + BUG_ON(cpu != 0); + cpu_asid_cache(cpu) = ASID_USER_FIRST; +} + +void __init smp_cpus_done(unsigned int max_cpus) +{ +} + +static int boot_secondary_processors = 1; /* Set with xt-gdb via .xt-gdb */ +static DECLARE_COMPLETION(cpu_running); + +void secondary_start_kernel(void) +{ + struct mm_struct *mm = &init_mm; + unsigned int cpu = smp_processor_id(); + + init_mmu(); + +#ifdef CONFIG_DEBUG_KERNEL + if (boot_secondary_processors == 0) { + pr_debug("%s: boot_secondary_processors:%d; Hanging cpu:%d\n", + __func__, boot_secondary_processors, cpu); + for (;;) + __asm__ __volatile__ ("waiti " __stringify(LOCKLEVEL)); + } + + pr_debug("%s: boot_secondary_processors:%d; Booting cpu:%d\n", + __func__, boot_secondary_processors, cpu); +#endif + /* Init EXCSAVE1 */ + + secondary_trap_init(); + + /* All kernel threads share the same mm context. */ + + atomic_inc(&mm->mm_users); + atomic_inc(&mm->mm_count); + current->active_mm = mm; + cpumask_set_cpu(cpu, mm_cpumask(mm)); + enter_lazy_tlb(mm, current); + + preempt_disable(); + trace_hardirqs_off(); + + calibrate_delay(); + + notify_cpu_starting(cpu); + + secondary_init_irq(); + local_timer_setup(cpu); + + set_cpu_online(cpu, true); + + local_irq_enable(); + + complete(&cpu_running); + + cpu_startup_entry(CPUHP_ONLINE); +} + +static void mx_cpu_start(void *p) +{ + unsigned cpu = (unsigned)p; + unsigned long run_stall_mask = get_er(MPSCORE); + + set_er(run_stall_mask & ~(1u << cpu), MPSCORE); + pr_debug("%s: cpu: %d, run_stall_mask: %lx ---> %lx\n", + __func__, cpu, run_stall_mask, get_er(MPSCORE)); +} + +static void mx_cpu_stop(void *p) +{ + unsigned cpu = (unsigned)p; + unsigned long run_stall_mask = get_er(MPSCORE); + + set_er(run_stall_mask | (1u << cpu), MPSCORE); + pr_debug("%s: cpu: %d, run_stall_mask: %lx ---> %lx\n", + __func__, cpu, run_stall_mask, get_er(MPSCORE)); +} + +#ifdef CONFIG_HOTPLUG_CPU +unsigned long cpu_start_id __cacheline_aligned; +#endif +unsigned long cpu_start_ccount; + +static int boot_secondary(unsigned int cpu, struct task_struct *ts) +{ + unsigned long timeout = jiffies + msecs_to_jiffies(1000); + unsigned long ccount; + int i; + +#ifdef CONFIG_HOTPLUG_CPU + cpu_start_id = cpu; + system_flush_invalidate_dcache_range( + (unsigned long)&cpu_start_id, sizeof(cpu_start_id)); +#endif + smp_call_function_single(0, mx_cpu_start, (void *)cpu, 1); + + for (i = 0; i < 2; ++i) { + do + ccount = get_ccount(); + while (!ccount); + + cpu_start_ccount = ccount; + + while (time_before(jiffies, timeout)) { + mb(); + if (!cpu_start_ccount) + break; + } + + if (cpu_start_ccount) { + smp_call_function_single(0, mx_cpu_stop, + (void *)cpu, 1); + cpu_start_ccount = 0; + return -EIO; + } + } + return 0; +} + +int __cpu_up(unsigned int cpu, struct task_struct *idle) +{ + int ret = 0; + + if (cpu_asid_cache(cpu) == 0) + cpu_asid_cache(cpu) = ASID_USER_FIRST; + + start_info.stack = (unsigned long)task_pt_regs(idle); + wmb(); + + pr_debug("%s: Calling wakeup_secondary(cpu:%d, idle:%p, sp: %08lx)\n", + __func__, cpu, idle, start_info.stack); + + ret = boot_secondary(cpu, idle); + if (ret == 0) { + wait_for_completion_timeout(&cpu_running, + msecs_to_jiffies(1000)); + if (!cpu_online(cpu)) + ret = -EIO; + } + + if (ret) + pr_err("CPU %u failed to boot\n", cpu); + + return ret; +} + +#ifdef CONFIG_HOTPLUG_CPU + +/* + * __cpu_disable runs on the processor to be shutdown. + */ +int __cpu_disable(void) +{ + unsigned int cpu = smp_processor_id(); + + /* + * Take this CPU offline. Once we clear this, we can't return, + * and we must not schedule until we're ready to give up the cpu. + */ + set_cpu_online(cpu, false); + + /* + * OK - migrate IRQs away from this CPU + */ + migrate_irqs(); + + /* + * Flush user cache and TLB mappings, and then remove this CPU + * from the vm mask set of all processes. + */ + local_flush_cache_all(); + local_flush_tlb_all(); + invalidate_page_directory(); + + clear_tasks_mm_cpumask(cpu); + + return 0; +} + +static void platform_cpu_kill(unsigned int cpu) +{ + smp_call_function_single(0, mx_cpu_stop, (void *)cpu, true); +} + +/* + * called on the thread which is asking for a CPU to be shutdown - + * waits until shutdown has completed, or it is timed out. + */ +void __cpu_die(unsigned int cpu) +{ + unsigned long timeout = jiffies + msecs_to_jiffies(1000); + while (time_before(jiffies, timeout)) { + system_invalidate_dcache_range((unsigned long)&cpu_start_id, + sizeof(cpu_start_id)); + if (cpu_start_id == -cpu) { + platform_cpu_kill(cpu); + return; + } + } + pr_err("CPU%u: unable to kill\n", cpu); +} + +void arch_cpu_idle_dead(void) +{ + cpu_die(); +} +/* + * Called from the idle thread for the CPU which has been shutdown. + * + * Note that we disable IRQs here, but do not re-enable them + * before returning to the caller. This is also the behaviour + * of the other hotplug-cpu capable cores, so presumably coming + * out of idle fixes this. + */ +void __ref cpu_die(void) +{ + idle_task_exit(); + local_irq_disable(); + __asm__ __volatile__( + " movi a2, cpu_restart\n" + " jx a2\n"); +} + +#endif /* CONFIG_HOTPLUG_CPU */ + +enum ipi_msg_type { + IPI_RESCHEDULE = 0, + IPI_CALL_FUNC, + IPI_CPU_STOP, + IPI_MAX +}; + +static const struct { + const char *short_text; + const char *long_text; +} ipi_text[] = { + { .short_text = "RES", .long_text = "Rescheduling interrupts" }, + { .short_text = "CAL", .long_text = "Function call interrupts" }, + { .short_text = "DIE", .long_text = "CPU shutdown interrupts" }, +}; + +struct ipi_data { + unsigned long ipi_count[IPI_MAX]; +}; + +static DEFINE_PER_CPU(struct ipi_data, ipi_data); + +static void send_ipi_message(const struct cpumask *callmask, + enum ipi_msg_type msg_id) +{ + int index; + unsigned long mask = 0; + + for_each_cpu(index, callmask) + if (index != smp_processor_id()) + mask |= 1 << index; + + set_er(mask, MIPISET(msg_id)); +} + +void arch_send_call_function_ipi_mask(const struct cpumask *mask) +{ + send_ipi_message(mask, IPI_CALL_FUNC); +} + +void arch_send_call_function_single_ipi(int cpu) +{ + send_ipi_message(cpumask_of(cpu), IPI_CALL_FUNC); +} + +void smp_send_reschedule(int cpu) +{ + send_ipi_message(cpumask_of(cpu), IPI_RESCHEDULE); +} + +void smp_send_stop(void) +{ + struct cpumask targets; + + cpumask_copy(&targets, cpu_online_mask); + cpumask_clear_cpu(smp_processor_id(), &targets); + send_ipi_message(&targets, IPI_CPU_STOP); +} + +static void ipi_cpu_stop(unsigned int cpu) +{ + set_cpu_online(cpu, false); + machine_halt(); +} + +irqreturn_t ipi_interrupt(int irq, void *dev_id) +{ + unsigned int cpu = smp_processor_id(); + struct ipi_data *ipi = &per_cpu(ipi_data, cpu); + unsigned int msg; + unsigned i; + + msg = get_er(MIPICAUSE(cpu)); + for (i = 0; i < IPI_MAX; i++) + if (msg & (1 << i)) { + set_er(1 << i, MIPICAUSE(cpu)); + ++ipi->ipi_count[i]; + } + + if (msg & (1 << IPI_RESCHEDULE)) + scheduler_ipi(); + if (msg & (1 << IPI_CALL_FUNC)) + generic_smp_call_function_interrupt(); + if (msg & (1 << IPI_CPU_STOP)) + ipi_cpu_stop(cpu); + + return IRQ_HANDLED; +} + +void show_ipi_list(struct seq_file *p, int prec) +{ + unsigned int cpu; + unsigned i; + + for (i = 0; i < IPI_MAX; ++i) { + seq_printf(p, "%*s:", prec, ipi_text[i].short_text); + for_each_online_cpu(cpu) + seq_printf(p, " %10lu", + per_cpu(ipi_data, cpu).ipi_count[i]); + seq_printf(p, " %s\n", ipi_text[i].long_text); + } +} + +int setup_profiling_timer(unsigned int multiplier) +{ + pr_debug("setup_profiling_timer %d\n", multiplier); + return 0; +} + +/* TLB flush functions */ + +struct flush_data { + struct vm_area_struct *vma; + unsigned long addr1; + unsigned long addr2; +}; + +static void ipi_flush_tlb_all(void *arg) +{ + local_flush_tlb_all(); +} + +void flush_tlb_all(void) +{ + on_each_cpu(ipi_flush_tlb_all, NULL, 1); +} + +static void ipi_flush_tlb_mm(void *arg) +{ + local_flush_tlb_mm(arg); +} + +void flush_tlb_mm(struct mm_struct *mm) +{ + on_each_cpu(ipi_flush_tlb_mm, mm, 1); +} + +static void ipi_flush_tlb_page(void *arg) +{ + struct flush_data *fd = arg; + local_flush_tlb_page(fd->vma, fd->addr1); +} + +void flush_tlb_page(struct vm_area_struct *vma, unsigned long addr) +{ + struct flush_data fd = { + .vma = vma, + .addr1 = addr, + }; + on_each_cpu(ipi_flush_tlb_page, &fd, 1); +} + +static void ipi_flush_tlb_range(void *arg) +{ + struct flush_data *fd = arg; + local_flush_tlb_range(fd->vma, fd->addr1, fd->addr2); +} + +void flush_tlb_range(struct vm_area_struct *vma, + unsigned long start, unsigned long end) +{ + struct flush_data fd = { + .vma = vma, + .addr1 = start, + .addr2 = end, + }; + on_each_cpu(ipi_flush_tlb_range, &fd, 1); +} + +static void ipi_flush_tlb_kernel_range(void *arg) +{ + struct flush_data *fd = arg; + local_flush_tlb_kernel_range(fd->addr1, fd->addr2); +} + +void flush_tlb_kernel_range(unsigned long start, unsigned long end) +{ + struct flush_data fd = { + .addr1 = start, + .addr2 = end, + }; + on_each_cpu(ipi_flush_tlb_kernel_range, &fd, 1); +} + +/* Cache flush functions */ + +static void ipi_flush_cache_all(void *arg) +{ + local_flush_cache_all(); +} + +void flush_cache_all(void) +{ + on_each_cpu(ipi_flush_cache_all, NULL, 1); +} + +static void ipi_flush_cache_page(void *arg) +{ + struct flush_data *fd = arg; + local_flush_cache_page(fd->vma, fd->addr1, fd->addr2); +} + +void flush_cache_page(struct vm_area_struct *vma, + unsigned long address, unsigned long pfn) +{ + struct flush_data fd = { + .vma = vma, + .addr1 = address, + .addr2 = pfn, + }; + on_each_cpu(ipi_flush_cache_page, &fd, 1); +} + +static void ipi_flush_cache_range(void *arg) +{ + struct flush_data *fd = arg; + local_flush_cache_range(fd->vma, fd->addr1, fd->addr2); +} + +void flush_cache_range(struct vm_area_struct *vma, + unsigned long start, unsigned long end) +{ + struct flush_data fd = { + .vma = vma, + .addr1 = start, + .addr2 = end, + }; + on_each_cpu(ipi_flush_cache_range, &fd, 1); +} + +static void ipi_flush_icache_range(void *arg) +{ + struct flush_data *fd = arg; + local_flush_icache_range(fd->addr1, fd->addr2); +} + +void flush_icache_range(unsigned long start, unsigned long end) +{ + struct flush_data fd = { + .addr1 = start, + .addr2 = end, + }; + on_each_cpu(ipi_flush_icache_range, &fd, 1); +} +EXPORT_SYMBOL(flush_icache_range); + +/* ------------------------------------------------------------------------- */ + +static void ipi_invalidate_dcache_range(void *arg) +{ + struct flush_data *fd = arg; + __invalidate_dcache_range(fd->addr1, fd->addr2); +} + +static void system_invalidate_dcache_range(unsigned long start, + unsigned long size) +{ + struct flush_data fd = { + .addr1 = start, + .addr2 = size, + }; + on_each_cpu(ipi_invalidate_dcache_range, &fd, 1); +} + +static void ipi_flush_invalidate_dcache_range(void *arg) +{ + struct flush_data *fd = arg; + __flush_invalidate_dcache_range(fd->addr1, fd->addr2); +} + +static void system_flush_invalidate_dcache_range(unsigned long start, + unsigned long size) +{ + struct flush_data fd = { + .addr1 = start, + .addr2 = size, + }; + on_each_cpu(ipi_flush_invalidate_dcache_range, &fd, 1); +} diff --git a/arch/xtensa/kernel/stacktrace.c b/arch/xtensa/kernel/stacktrace.c new file mode 100644 index 000000000..7d2c317bd --- /dev/null +++ b/arch/xtensa/kernel/stacktrace.c @@ -0,0 +1,120 @@ +/* + * arch/xtensa/kernel/stacktrace.c + * + * This file is subject to the terms and conditions of the GNU General Public + * License. See the file "COPYING" in the main directory of this archive + * for more details. + * + * Copyright (C) 2001 - 2013 Tensilica Inc. + */ +#include <linux/export.h> +#include <linux/sched.h> +#include <linux/stacktrace.h> + +#include <asm/stacktrace.h> +#include <asm/traps.h> + +void walk_stackframe(unsigned long *sp, + int (*fn)(struct stackframe *frame, void *data), + void *data) +{ + unsigned long a0, a1; + unsigned long sp_end; + + a1 = (unsigned long)sp; + sp_end = ALIGN(a1, THREAD_SIZE); + + spill_registers(); + + while (a1 < sp_end) { + struct stackframe frame; + + sp = (unsigned long *)a1; + + a0 = *(sp - 4); + a1 = *(sp - 3); + + if (a1 <= (unsigned long)sp) + break; + + frame.pc = MAKE_PC_FROM_RA(a0, a1); + frame.sp = a1; + + if (fn(&frame, data)) + return; + } +} + +#ifdef CONFIG_STACKTRACE + +struct stack_trace_data { + struct stack_trace *trace; + unsigned skip; +}; + +static int stack_trace_cb(struct stackframe *frame, void *data) +{ + struct stack_trace_data *trace_data = data; + struct stack_trace *trace = trace_data->trace; + + if (trace_data->skip) { + --trace_data->skip; + return 0; + } + if (!kernel_text_address(frame->pc)) + return 0; + + trace->entries[trace->nr_entries++] = frame->pc; + return trace->nr_entries >= trace->max_entries; +} + +void save_stack_trace_tsk(struct task_struct *task, struct stack_trace *trace) +{ + struct stack_trace_data trace_data = { + .trace = trace, + .skip = trace->skip, + }; + walk_stackframe(stack_pointer(task), stack_trace_cb, &trace_data); +} +EXPORT_SYMBOL_GPL(save_stack_trace_tsk); + +void save_stack_trace(struct stack_trace *trace) +{ + save_stack_trace_tsk(current, trace); +} +EXPORT_SYMBOL_GPL(save_stack_trace); + +#endif + +#ifdef CONFIG_FRAME_POINTER + +struct return_addr_data { + unsigned long addr; + unsigned skip; +}; + +static int return_address_cb(struct stackframe *frame, void *data) +{ + struct return_addr_data *r = data; + + if (r->skip) { + --r->skip; + return 0; + } + if (!kernel_text_address(frame->pc)) + return 0; + r->addr = frame->pc; + return 1; +} + +unsigned long return_address(unsigned level) +{ + struct return_addr_data r = { + .skip = level + 1, + }; + walk_stackframe(stack_pointer(NULL), return_address_cb, &r); + return r.addr; +} +EXPORT_SYMBOL(return_address); + +#endif diff --git a/arch/xtensa/kernel/syscall.c b/arch/xtensa/kernel/syscall.c new file mode 100644 index 000000000..83cf49685 --- /dev/null +++ b/arch/xtensa/kernel/syscall.c @@ -0,0 +1,97 @@ +/* + * arch/xtensa/kernel/syscall.c + * + * This file is subject to the terms and conditions of the GNU General Public + * License. See the file "COPYING" in the main directory of this archive + * for more details. + * + * Copyright (C) 2001 - 2005 Tensilica Inc. + * Copyright (C) 2000 Silicon Graphics, Inc. + * Copyright (C) 1995 - 2000 by Ralf Baechle + * + * Joe Taylor <joe@tensilica.com, joetylr@yahoo.com> + * Marc Gauthier <marc@tensilica.com, marc@alumni.uwaterloo.ca> + * Chris Zankel <chris@zankel.net> + * Kevin Chea + * + */ +#include <asm/uaccess.h> +#include <asm/syscall.h> +#include <asm/unistd.h> +#include <linux/linkage.h> +#include <linux/stringify.h> +#include <linux/errno.h> +#include <linux/syscalls.h> +#include <linux/file.h> +#include <linux/fs.h> +#include <linux/mman.h> +#include <linux/shm.h> + +typedef void (*syscall_t)(void); + +syscall_t sys_call_table[__NR_syscall_count] /* FIXME __cacheline_aligned */= { + [0 ... __NR_syscall_count - 1] = (syscall_t)&sys_ni_syscall, + +#define __SYSCALL(nr,symbol,nargs) [ nr ] = (syscall_t)symbol, +#include <uapi/asm/unistd.h> +}; + +#define COLOUR_ALIGN(addr, pgoff) \ + ((((addr) + SHMLBA - 1) & ~(SHMLBA - 1)) + \ + (((pgoff) << PAGE_SHIFT) & (SHMLBA - 1))) + +asmlinkage long xtensa_shmat(int shmid, char __user *shmaddr, int shmflg) +{ + unsigned long ret; + long err; + + err = do_shmat(shmid, shmaddr, shmflg, &ret, SHMLBA); + if (err) + return err; + return (long)ret; +} + +asmlinkage long xtensa_fadvise64_64(int fd, int advice, + unsigned long long offset, unsigned long long len) +{ + return sys_fadvise64_64(fd, offset, len, advice); +} + +#ifdef CONFIG_MMU +unsigned long arch_get_unmapped_area(struct file *filp, unsigned long addr, + unsigned long len, unsigned long pgoff, unsigned long flags) +{ + struct vm_area_struct *vmm; + + if (flags & MAP_FIXED) { + /* We do not accept a shared mapping if it would violate + * cache aliasing constraints. + */ + if ((flags & MAP_SHARED) && + ((addr - (pgoff << PAGE_SHIFT)) & (SHMLBA - 1))) + return -EINVAL; + return addr; + } + + if (len > TASK_SIZE) + return -ENOMEM; + if (!addr) + addr = TASK_UNMAPPED_BASE; + + if (flags & MAP_SHARED) + addr = COLOUR_ALIGN(addr, pgoff); + else + addr = PAGE_ALIGN(addr); + + for (vmm = find_vma(current->mm, addr); ; vmm = vmm->vm_next) { + /* At this point: (!vmm || addr < vmm->vm_end). */ + if (TASK_SIZE - len < addr) + return -ENOMEM; + if (!vmm || addr + len <= vmm->vm_start) + return addr; + addr = vmm->vm_end; + if (flags & MAP_SHARED) + addr = COLOUR_ALIGN(addr, pgoff); + } +} +#endif diff --git a/arch/xtensa/kernel/time.c b/arch/xtensa/kernel/time.c new file mode 100644 index 000000000..2a1823de6 --- /dev/null +++ b/arch/xtensa/kernel/time.c @@ -0,0 +1,181 @@ +/* + * arch/xtensa/kernel/time.c + * + * Timer and clock support. + * + * This file is subject to the terms and conditions of the GNU General Public + * License. See the file "COPYING" in the main directory of this archive + * for more details. + * + * Copyright (C) 2005 Tensilica Inc. + * + * Chris Zankel <chris@zankel.net> + */ + +#include <linux/errno.h> +#include <linux/sched.h> +#include <linux/time.h> +#include <linux/clocksource.h> +#include <linux/clockchips.h> +#include <linux/interrupt.h> +#include <linux/module.h> +#include <linux/init.h> +#include <linux/irq.h> +#include <linux/profile.h> +#include <linux/delay.h> +#include <linux/irqdomain.h> +#include <linux/sched_clock.h> + +#include <asm/timex.h> +#include <asm/platform.h> + +unsigned long ccount_freq; /* ccount Hz */ +EXPORT_SYMBOL(ccount_freq); + +static cycle_t ccount_read(struct clocksource *cs) +{ + return (cycle_t)get_ccount(); +} + +static u64 notrace ccount_sched_clock_read(void) +{ + return get_ccount(); +} + +static struct clocksource ccount_clocksource = { + .name = "ccount", + .rating = 200, + .read = ccount_read, + .mask = CLOCKSOURCE_MASK(32), + .flags = CLOCK_SOURCE_IS_CONTINUOUS, +}; + +static int ccount_timer_set_next_event(unsigned long delta, + struct clock_event_device *dev); +static void ccount_timer_set_mode(enum clock_event_mode mode, + struct clock_event_device *evt); +struct ccount_timer { + struct clock_event_device evt; + int irq_enabled; + char name[24]; +}; +static DEFINE_PER_CPU(struct ccount_timer, ccount_timer); + +static int ccount_timer_set_next_event(unsigned long delta, + struct clock_event_device *dev) +{ + unsigned long flags, next; + int ret = 0; + + local_irq_save(flags); + next = get_ccount() + delta; + set_linux_timer(next); + if (next - get_ccount() > delta) + ret = -ETIME; + local_irq_restore(flags); + + return ret; +} + +static void ccount_timer_set_mode(enum clock_event_mode mode, + struct clock_event_device *evt) +{ + struct ccount_timer *timer = + container_of(evt, struct ccount_timer, evt); + + /* + * There is no way to disable the timer interrupt at the device level, + * only at the intenable register itself. Since enable_irq/disable_irq + * calls are nested, we need to make sure that these calls are + * balanced. + */ + switch (mode) { + case CLOCK_EVT_MODE_SHUTDOWN: + case CLOCK_EVT_MODE_UNUSED: + if (timer->irq_enabled) { + disable_irq(evt->irq); + timer->irq_enabled = 0; + } + break; + case CLOCK_EVT_MODE_RESUME: + case CLOCK_EVT_MODE_ONESHOT: + if (!timer->irq_enabled) { + enable_irq(evt->irq); + timer->irq_enabled = 1; + } + default: + break; + } +} + +static irqreturn_t timer_interrupt(int irq, void *dev_id); +static struct irqaction timer_irqaction = { + .handler = timer_interrupt, + .flags = IRQF_TIMER, + .name = "timer", +}; + +void local_timer_setup(unsigned cpu) +{ + struct ccount_timer *timer = &per_cpu(ccount_timer, cpu); + struct clock_event_device *clockevent = &timer->evt; + + timer->irq_enabled = 1; + clockevent->name = timer->name; + snprintf(timer->name, sizeof(timer->name), "ccount_clockevent_%u", cpu); + clockevent->features = CLOCK_EVT_FEAT_ONESHOT; + clockevent->rating = 300; + clockevent->set_next_event = ccount_timer_set_next_event; + clockevent->set_mode = ccount_timer_set_mode; + clockevent->cpumask = cpumask_of(cpu); + clockevent->irq = irq_create_mapping(NULL, LINUX_TIMER_INT); + if (WARN(!clockevent->irq, "error: can't map timer irq")) + return; + clockevents_config_and_register(clockevent, ccount_freq, + 0xf, 0xffffffff); +} + +void __init time_init(void) +{ +#ifdef CONFIG_XTENSA_CALIBRATE_CCOUNT + printk("Calibrating CPU frequency "); + platform_calibrate_ccount(); + printk("%d.%02d MHz\n", (int)ccount_freq/1000000, + (int)(ccount_freq/10000)%100); +#else + ccount_freq = CONFIG_XTENSA_CPU_CLOCK*1000000UL; +#endif + clocksource_register_hz(&ccount_clocksource, ccount_freq); + local_timer_setup(0); + setup_irq(this_cpu_ptr(&ccount_timer)->evt.irq, &timer_irqaction); + sched_clock_register(ccount_sched_clock_read, 32, ccount_freq); + clocksource_of_init(); +} + +/* + * The timer interrupt is called HZ times per second. + */ + +irqreturn_t timer_interrupt(int irq, void *dev_id) +{ + struct clock_event_device *evt = &this_cpu_ptr(&ccount_timer)->evt; + + set_linux_timer(get_linux_timer()); + evt->event_handler(evt); + + /* Allow platform to do something useful (Wdog). */ + platform_heartbeat(); + + return IRQ_HANDLED; +} + +#ifndef CONFIG_GENERIC_CALIBRATE_DELAY +void calibrate_delay(void) +{ + loops_per_jiffy = ccount_freq / HZ; + printk("Calibrating delay loop (skipped)... " + "%lu.%02lu BogoMIPS preset\n", + loops_per_jiffy/(1000000/HZ), + (loops_per_jiffy/(10000/HZ)) % 100); +} +#endif diff --git a/arch/xtensa/kernel/traps.c b/arch/xtensa/kernel/traps.c new file mode 100644 index 000000000..9d2f45f01 --- /dev/null +++ b/arch/xtensa/kernel/traps.c @@ -0,0 +1,517 @@ +/* + * arch/xtensa/kernel/traps.c + * + * Exception handling. + * + * Derived from code with the following copyrights: + * Copyright (C) 1994 - 1999 by Ralf Baechle + * Modified for R3000 by Paul M. Antoine, 1995, 1996 + * Complete output from die() by Ulf Carlsson, 1998 + * Copyright (C) 1999 Silicon Graphics, Inc. + * + * Essentially rewritten for the Xtensa architecture port. + * + * Copyright (C) 2001 - 2013 Tensilica Inc. + * + * Joe Taylor <joe@tensilica.com, joetylr@yahoo.com> + * Chris Zankel <chris@zankel.net> + * Marc Gauthier<marc@tensilica.com, marc@alumni.uwaterloo.ca> + * Kevin Chea + * + * This file is subject to the terms and conditions of the GNU General Public + * License. See the file "COPYING" in the main directory of this archive + * for more details. + */ + +#include <linux/kernel.h> +#include <linux/sched.h> +#include <linux/init.h> +#include <linux/module.h> +#include <linux/stringify.h> +#include <linux/kallsyms.h> +#include <linux/delay.h> +#include <linux/hardirq.h> + +#include <asm/stacktrace.h> +#include <asm/ptrace.h> +#include <asm/timex.h> +#include <asm/uaccess.h> +#include <asm/pgtable.h> +#include <asm/processor.h> +#include <asm/traps.h> + +#ifdef CONFIG_KGDB +extern int gdb_enter; +extern int return_from_debug_flag; +#endif + +/* + * Machine specific interrupt handlers + */ + +extern void kernel_exception(void); +extern void user_exception(void); + +extern void fast_syscall_kernel(void); +extern void fast_syscall_user(void); +extern void fast_alloca(void); +extern void fast_unaligned(void); +extern void fast_second_level_miss(void); +extern void fast_store_prohibited(void); +extern void fast_coprocessor(void); + +extern void do_illegal_instruction (struct pt_regs*); +extern void do_interrupt (struct pt_regs*); +extern void do_unaligned_user (struct pt_regs*); +extern void do_multihit (struct pt_regs*, unsigned long); +extern void do_page_fault (struct pt_regs*, unsigned long); +extern void do_debug (struct pt_regs*); +extern void system_call (struct pt_regs*); + +/* + * The vector table must be preceded by a save area (which + * implies it must be in RAM, unless one places RAM immediately + * before a ROM and puts the vector at the start of the ROM (!)) + */ + +#define KRNL 0x01 +#define USER 0x02 + +#define COPROCESSOR(x) \ +{ EXCCAUSE_COPROCESSOR ## x ## _DISABLED, USER, fast_coprocessor } + +typedef struct { + int cause; + int fast; + void* handler; +} dispatch_init_table_t; + +static dispatch_init_table_t __initdata dispatch_init_table[] = { + +{ EXCCAUSE_ILLEGAL_INSTRUCTION, 0, do_illegal_instruction}, +{ EXCCAUSE_SYSTEM_CALL, KRNL, fast_syscall_kernel }, +{ EXCCAUSE_SYSTEM_CALL, USER, fast_syscall_user }, +{ EXCCAUSE_SYSTEM_CALL, 0, system_call }, +/* EXCCAUSE_INSTRUCTION_FETCH unhandled */ +/* EXCCAUSE_LOAD_STORE_ERROR unhandled*/ +{ EXCCAUSE_LEVEL1_INTERRUPT, 0, do_interrupt }, +{ EXCCAUSE_ALLOCA, USER|KRNL, fast_alloca }, +/* EXCCAUSE_INTEGER_DIVIDE_BY_ZERO unhandled */ +/* EXCCAUSE_PRIVILEGED unhandled */ +#if XCHAL_UNALIGNED_LOAD_EXCEPTION || XCHAL_UNALIGNED_STORE_EXCEPTION +#ifdef CONFIG_XTENSA_UNALIGNED_USER +{ EXCCAUSE_UNALIGNED, USER, fast_unaligned }, +#endif +{ EXCCAUSE_UNALIGNED, 0, do_unaligned_user }, +{ EXCCAUSE_UNALIGNED, KRNL, fast_unaligned }, +#endif +#ifdef CONFIG_MMU +{ EXCCAUSE_ITLB_MISS, 0, do_page_fault }, +{ EXCCAUSE_ITLB_MISS, USER|KRNL, fast_second_level_miss}, +{ EXCCAUSE_ITLB_MULTIHIT, 0, do_multihit }, +{ EXCCAUSE_ITLB_PRIVILEGE, 0, do_page_fault }, +/* EXCCAUSE_SIZE_RESTRICTION unhandled */ +{ EXCCAUSE_FETCH_CACHE_ATTRIBUTE, 0, do_page_fault }, +{ EXCCAUSE_DTLB_MISS, USER|KRNL, fast_second_level_miss}, +{ EXCCAUSE_DTLB_MISS, 0, do_page_fault }, +{ EXCCAUSE_DTLB_MULTIHIT, 0, do_multihit }, +{ EXCCAUSE_DTLB_PRIVILEGE, 0, do_page_fault }, +/* EXCCAUSE_DTLB_SIZE_RESTRICTION unhandled */ +{ EXCCAUSE_STORE_CACHE_ATTRIBUTE, USER|KRNL, fast_store_prohibited }, +{ EXCCAUSE_STORE_CACHE_ATTRIBUTE, 0, do_page_fault }, +{ EXCCAUSE_LOAD_CACHE_ATTRIBUTE, 0, do_page_fault }, +#endif /* CONFIG_MMU */ +/* XCCHAL_EXCCAUSE_FLOATING_POINT unhandled */ +#if XTENSA_HAVE_COPROCESSOR(0) +COPROCESSOR(0), +#endif +#if XTENSA_HAVE_COPROCESSOR(1) +COPROCESSOR(1), +#endif +#if XTENSA_HAVE_COPROCESSOR(2) +COPROCESSOR(2), +#endif +#if XTENSA_HAVE_COPROCESSOR(3) +COPROCESSOR(3), +#endif +#if XTENSA_HAVE_COPROCESSOR(4) +COPROCESSOR(4), +#endif +#if XTENSA_HAVE_COPROCESSOR(5) +COPROCESSOR(5), +#endif +#if XTENSA_HAVE_COPROCESSOR(6) +COPROCESSOR(6), +#endif +#if XTENSA_HAVE_COPROCESSOR(7) +COPROCESSOR(7), +#endif +{ EXCCAUSE_MAPPED_DEBUG, 0, do_debug }, +{ -1, -1, 0 } + +}; + +/* The exception table <exc_table> serves two functions: + * 1. it contains three dispatch tables (fast_user, fast_kernel, default-c) + * 2. it is a temporary memory buffer for the exception handlers. + */ + +DEFINE_PER_CPU(unsigned long, exc_table[EXC_TABLE_SIZE/4]); + +void die(const char*, struct pt_regs*, long); + +static inline void +__die_if_kernel(const char *str, struct pt_regs *regs, long err) +{ + if (!user_mode(regs)) + die(str, regs, err); +} + +/* + * Unhandled Exceptions. Kill user task or panic if in kernel space. + */ + +void do_unhandled(struct pt_regs *regs, unsigned long exccause) +{ + __die_if_kernel("Caught unhandled exception - should not happen", + regs, SIGKILL); + + /* If in user mode, send SIGILL signal to current process */ + printk("Caught unhandled exception in '%s' " + "(pid = %d, pc = %#010lx) - should not happen\n" + "\tEXCCAUSE is %ld\n", + current->comm, task_pid_nr(current), regs->pc, exccause); + force_sig(SIGILL, current); +} + +/* + * Multi-hit exception. This if fatal! + */ + +void do_multihit(struct pt_regs *regs, unsigned long exccause) +{ + die("Caught multihit exception", regs, SIGKILL); +} + +/* + * IRQ handler. + */ + +extern void do_IRQ(int, struct pt_regs *); + +void do_interrupt(struct pt_regs *regs) +{ + static const unsigned int_level_mask[] = { + 0, + XCHAL_INTLEVEL1_MASK, + XCHAL_INTLEVEL2_MASK, + XCHAL_INTLEVEL3_MASK, + XCHAL_INTLEVEL4_MASK, + XCHAL_INTLEVEL5_MASK, + XCHAL_INTLEVEL6_MASK, + XCHAL_INTLEVEL7_MASK, + }; + struct pt_regs *old_regs = set_irq_regs(regs); + + irq_enter(); + + for (;;) { + unsigned intread = get_sr(interrupt); + unsigned intenable = get_sr(intenable); + unsigned int_at_level = intread & intenable; + unsigned level; + + for (level = LOCKLEVEL; level > 0; --level) { + if (int_at_level & int_level_mask[level]) { + int_at_level &= int_level_mask[level]; + break; + } + } + + if (level == 0) + break; + + do_IRQ(__ffs(int_at_level), regs); + } + + irq_exit(); + set_irq_regs(old_regs); +} + +/* + * Illegal instruction. Fatal if in kernel space. + */ + +void +do_illegal_instruction(struct pt_regs *regs) +{ + __die_if_kernel("Illegal instruction in kernel", regs, SIGKILL); + + /* If in user mode, send SIGILL signal to current process. */ + + printk("Illegal Instruction in '%s' (pid = %d, pc = %#010lx)\n", + current->comm, task_pid_nr(current), regs->pc); + force_sig(SIGILL, current); +} + + +/* + * Handle unaligned memory accesses from user space. Kill task. + * + * If CONFIG_UNALIGNED_USER is not set, we don't allow unaligned memory + * accesses causes from user space. + */ + +#if XCHAL_UNALIGNED_LOAD_EXCEPTION || XCHAL_UNALIGNED_STORE_EXCEPTION +void +do_unaligned_user (struct pt_regs *regs) +{ + siginfo_t info; + + __die_if_kernel("Unhandled unaligned exception in kernel", + regs, SIGKILL); + + current->thread.bad_vaddr = regs->excvaddr; + current->thread.error_code = -3; + printk("Unaligned memory access to %08lx in '%s' " + "(pid = %d, pc = %#010lx)\n", + regs->excvaddr, current->comm, task_pid_nr(current), regs->pc); + info.si_signo = SIGBUS; + info.si_errno = 0; + info.si_code = BUS_ADRALN; + info.si_addr = (void *) regs->excvaddr; + force_sig_info(SIGSEGV, &info, current); + +} +#endif + +void +do_debug(struct pt_regs *regs) +{ +#ifdef CONFIG_KGDB + /* If remote debugging is configured AND enabled, we give control to + * kgdb. Otherwise, we fall through, perhaps giving control to the + * native debugger. + */ + + if (gdb_enter) { + extern void gdb_handle_exception(struct pt_regs *); + gdb_handle_exception(regs); + return_from_debug_flag = 1; + return; + } +#endif + + __die_if_kernel("Breakpoint in kernel", regs, SIGKILL); + + /* If in user mode, send SIGTRAP signal to current process */ + + force_sig(SIGTRAP, current); +} + + +static void set_handler(int idx, void *handler) +{ + unsigned int cpu; + + for_each_possible_cpu(cpu) + per_cpu(exc_table, cpu)[idx] = (unsigned long)handler; +} + +/* Set exception C handler - for temporary use when probing exceptions */ + +void * __init trap_set_handler(int cause, void *handler) +{ + void *previous = (void *)per_cpu(exc_table, 0)[ + EXC_TABLE_DEFAULT / 4 + cause]; + set_handler(EXC_TABLE_DEFAULT / 4 + cause, handler); + return previous; +} + + +static void trap_init_excsave(void) +{ + unsigned long excsave1 = (unsigned long)this_cpu_ptr(exc_table); + __asm__ __volatile__("wsr %0, excsave1\n" : : "a" (excsave1)); +} + +/* + * Initialize dispatch tables. + * + * The exception vectors are stored compressed the __init section in the + * dispatch_init_table. This function initializes the following three tables + * from that compressed table: + * - fast user first dispatch table for user exceptions + * - fast kernel first dispatch table for kernel exceptions + * - default C-handler C-handler called by the default fast handler. + * + * See vectors.S for more details. + */ + +void __init trap_init(void) +{ + int i; + + /* Setup default vectors. */ + + for(i = 0; i < 64; i++) { + set_handler(EXC_TABLE_FAST_USER/4 + i, user_exception); + set_handler(EXC_TABLE_FAST_KERNEL/4 + i, kernel_exception); + set_handler(EXC_TABLE_DEFAULT/4 + i, do_unhandled); + } + + /* Setup specific handlers. */ + + for(i = 0; dispatch_init_table[i].cause >= 0; i++) { + + int fast = dispatch_init_table[i].fast; + int cause = dispatch_init_table[i].cause; + void *handler = dispatch_init_table[i].handler; + + if (fast == 0) + set_handler (EXC_TABLE_DEFAULT/4 + cause, handler); + if (fast && fast & USER) + set_handler (EXC_TABLE_FAST_USER/4 + cause, handler); + if (fast && fast & KRNL) + set_handler (EXC_TABLE_FAST_KERNEL/4 + cause, handler); + } + + /* Initialize EXCSAVE_1 to hold the address of the exception table. */ + trap_init_excsave(); +} + +#ifdef CONFIG_SMP +void secondary_trap_init(void) +{ + trap_init_excsave(); +} +#endif + +/* + * This function dumps the current valid window frame and other base registers. + */ + +void show_regs(struct pt_regs * regs) +{ + int i, wmask; + + show_regs_print_info(KERN_DEFAULT); + + wmask = regs->wmask & ~1; + + for (i = 0; i < 16; i++) { + if ((i % 8) == 0) + printk(KERN_INFO "a%02d:", i); + printk(KERN_CONT " %08lx", regs->areg[i]); + } + printk(KERN_CONT "\n"); + + printk("pc: %08lx, ps: %08lx, depc: %08lx, excvaddr: %08lx\n", + regs->pc, regs->ps, regs->depc, regs->excvaddr); + printk("lbeg: %08lx, lend: %08lx lcount: %08lx, sar: %08lx\n", + regs->lbeg, regs->lend, regs->lcount, regs->sar); + if (user_mode(regs)) + printk("wb: %08lx, ws: %08lx, wmask: %08lx, syscall: %ld\n", + regs->windowbase, regs->windowstart, regs->wmask, + regs->syscall); +} + +static int show_trace_cb(struct stackframe *frame, void *data) +{ + if (kernel_text_address(frame->pc)) { + printk(" [<%08lx>] ", frame->pc); + print_symbol("%s\n", frame->pc); + } + return 0; +} + +void show_trace(struct task_struct *task, unsigned long *sp) +{ + if (!sp) + sp = stack_pointer(task); + + printk("Call Trace:"); +#ifdef CONFIG_KALLSYMS + printk("\n"); +#endif + walk_stackframe(sp, show_trace_cb, NULL); + printk("\n"); +} + +/* + * This routine abuses get_user()/put_user() to reference pointers + * with at least a bit of error checking ... + */ + +static int kstack_depth_to_print = 24; + +void show_stack(struct task_struct *task, unsigned long *sp) +{ + int i = 0; + unsigned long *stack; + + if (!sp) + sp = stack_pointer(task); + stack = sp; + + printk("\nStack: "); + + for (i = 0; i < kstack_depth_to_print; i++) { + if (kstack_end(sp)) + break; + if (i && ((i % 8) == 0)) + printk("\n "); + printk("%08lx ", *sp++); + } + printk("\n"); + show_trace(task, stack); +} + +void show_code(unsigned int *pc) +{ + long i; + + printk("\nCode:"); + + for(i = -3 ; i < 6 ; i++) { + unsigned long insn; + if (__get_user(insn, pc + i)) { + printk(" (Bad address in pc)\n"); + break; + } + printk("%c%08lx%c",(i?' ':'<'),insn,(i?' ':'>')); + } +} + +DEFINE_SPINLOCK(die_lock); + +void die(const char * str, struct pt_regs * regs, long err) +{ + static int die_counter; + int nl = 0; + + console_verbose(); + spin_lock_irq(&die_lock); + + printk("%s: sig: %ld [#%d]\n", str, err, ++die_counter); +#ifdef CONFIG_PREEMPT + printk("PREEMPT "); + nl = 1; +#endif + if (nl) + printk("\n"); + show_regs(regs); + if (!user_mode(regs)) + show_stack(NULL, (unsigned long*)regs->areg[1]); + + add_taint(TAINT_DIE, LOCKDEP_NOW_UNRELIABLE); + spin_unlock_irq(&die_lock); + + if (in_interrupt()) + panic("Fatal exception in interrupt"); + + if (panic_on_oops) + panic("Fatal exception"); + + do_exit(err); +} diff --git a/arch/xtensa/kernel/vectors.S b/arch/xtensa/kernel/vectors.S new file mode 100644 index 000000000..1b397a902 --- /dev/null +++ b/arch/xtensa/kernel/vectors.S @@ -0,0 +1,782 @@ +/* + * arch/xtensa/kernel/vectors.S + * + * This file contains all exception vectors (user, kernel, and double), + * as well as the window vectors (overflow and underflow), and the debug + * vector. These are the primary vectors executed by the processor if an + * exception occurs. + * + * This file is subject to the terms and conditions of the GNU General + * Public License. See the file "COPYING" in the main directory of + * this archive for more details. + * + * Copyright (C) 2005 - 2008 Tensilica, Inc. + * + * Chris Zankel <chris@zankel.net> + * + */ + +/* + * We use a two-level table approach. The user and kernel exception vectors + * use a first-level dispatch table to dispatch the exception to a registered + * fast handler or the default handler, if no fast handler was registered. + * The default handler sets up a C-stack and dispatches the exception to a + * registerd C handler in the second-level dispatch table. + * + * Fast handler entry condition: + * + * a0: trashed, original value saved on stack (PT_AREG0) + * a1: a1 + * a2: new stack pointer, original value in depc + * a3: dispatch table + * depc: a2, original value saved on stack (PT_DEPC) + * excsave_1: a3 + * + * The value for PT_DEPC saved to stack also functions as a boolean to + * indicate that the exception is either a double or a regular exception: + * + * PT_DEPC >= VALID_DOUBLE_EXCEPTION_ADDRESS: double exception + * < VALID_DOUBLE_EXCEPTION_ADDRESS: regular exception + * + * Note: Neither the kernel nor the user exception handler generate literals. + * + */ + +#include <linux/linkage.h> +#include <asm/ptrace.h> +#include <asm/current.h> +#include <asm/asm-offsets.h> +#include <asm/pgtable.h> +#include <asm/processor.h> +#include <asm/page.h> +#include <asm/thread_info.h> +#include <asm/vectors.h> + +#define WINDOW_VECTORS_SIZE 0x180 + + +/* + * User exception vector. (Exceptions with PS.UM == 1, PS.EXCM == 0) + * + * We get here when an exception occurred while we were in userland. + * We switch to the kernel stack and jump to the first level handler + * associated to the exception cause. + * + * Note: the saved kernel stack pointer (EXC_TABLE_KSTK) is already + * decremented by PT_USER_SIZE. + */ + + .section .UserExceptionVector.text, "ax" + +ENTRY(_UserExceptionVector) + + xsr a3, excsave1 # save a3 and get dispatch table + wsr a2, depc # save a2 + l32i a2, a3, EXC_TABLE_KSTK # load kernel stack to a2 + s32i a0, a2, PT_AREG0 # save a0 to ESF + rsr a0, exccause # retrieve exception cause + s32i a0, a2, PT_DEPC # mark it as a regular exception + addx4 a0, a0, a3 # find entry in table + l32i a0, a0, EXC_TABLE_FAST_USER # load handler + xsr a3, excsave1 # restore a3 and dispatch table + jx a0 + +ENDPROC(_UserExceptionVector) + +/* + * Kernel exception vector. (Exceptions with PS.UM == 0, PS.EXCM == 0) + * + * We get this exception when we were already in kernel space. + * We decrement the current stack pointer (kernel) by PT_SIZE and + * jump to the first-level handler associated with the exception cause. + * + * Note: we need to preserve space for the spill region. + */ + + .section .KernelExceptionVector.text, "ax" + +ENTRY(_KernelExceptionVector) + + xsr a3, excsave1 # save a3, and get dispatch table + wsr a2, depc # save a2 + addi a2, a1, -16-PT_SIZE # adjust stack pointer + s32i a0, a2, PT_AREG0 # save a0 to ESF + rsr a0, exccause # retrieve exception cause + s32i a0, a2, PT_DEPC # mark it as a regular exception + addx4 a0, a0, a3 # find entry in table + l32i a0, a0, EXC_TABLE_FAST_KERNEL # load handler address + xsr a3, excsave1 # restore a3 and dispatch table + jx a0 + +ENDPROC(_KernelExceptionVector) + +/* + * Double exception vector (Exceptions with PS.EXCM == 1) + * We get this exception when another exception occurs while were are + * already in an exception, such as window overflow/underflow exception, + * or 'expected' exceptions, for example memory exception when we were trying + * to read data from an invalid address in user space. + * + * Note that this vector is never invoked for level-1 interrupts, because such + * interrupts are disabled (masked) when PS.EXCM is set. + * + * We decode the exception and take the appropriate action. However, the + * double exception vector is much more careful, because a lot more error + * cases go through the double exception vector than through the user and + * kernel exception vectors. + * + * Occasionally, the kernel expects a double exception to occur. This usually + * happens when accessing user-space memory with the user's permissions + * (l32e/s32e instructions). The kernel state, though, is not always suitable + * for immediate transfer of control to handle_double, where "normal" exception + * processing occurs. Also in kernel mode, TLB misses can occur if accessing + * vmalloc memory, possibly requiring repair in a double exception handler. + * + * The variable at TABLE_FIXUP offset from the pointer in EXCSAVE_1 doubles as + * a boolean variable and a pointer to a fixup routine. If the variable + * EXC_TABLE_FIXUP is non-zero, this handler jumps to that address. A value of + * zero indicates to use the default kernel/user exception handler. + * There is only one exception, when the value is identical to the exc_table + * label, the kernel is in trouble. This mechanism is used to protect critical + * sections, mainly when the handler writes to the stack to assert the stack + * pointer is valid. Once the fixup/default handler leaves that area, the + * EXC_TABLE_FIXUP variable is reset to the fixup handler or zero. + * + * Procedures wishing to use this mechanism should set EXC_TABLE_FIXUP to the + * nonzero address of a fixup routine before it could cause a double exception + * and reset it before it returns. + * + * Some other things to take care of when a fast exception handler doesn't + * specify a particular fixup handler but wants to use the default handlers: + * + * - The original stack pointer (in a1) must not be modified. The fast + * exception handler should only use a2 as the stack pointer. + * + * - If the fast handler manipulates the stack pointer (in a2), it has to + * register a valid fixup handler and cannot use the default handlers. + * + * - The handler can use any other generic register from a3 to a15, but it + * must save the content of these registers to stack (PT_AREG3...PT_AREGx) + * + * - These registers must be saved before a double exception can occur. + * + * - If we ever implement handling signals while in double exceptions, the + * number of registers a fast handler has saved (excluding a0 and a1) must + * be written to PT_AREG1. (1 if only a3 is used, 2 for a3 and a4, etc. ) + * + * The fixup handlers are special handlers: + * + * - Fixup entry conditions differ from regular exceptions: + * + * a0: DEPC + * a1: a1 + * a2: trashed, original value in EXC_TABLE_DOUBLE_SAVE + * a3: exctable + * depc: a0 + * excsave_1: a3 + * + * - When the kernel enters the fixup handler, it still assumes it is in a + * critical section, so EXC_TABLE_FIXUP variable is set to exc_table. + * The fixup handler, therefore, has to re-register itself as the fixup + * handler before it returns from the double exception. + * + * - Fixup handler can share the same exception frame with the fast handler. + * The kernel stack pointer is not changed when entering the fixup handler. + * + * - Fixup handlers can jump to the default kernel and user exception + * handlers. Before it jumps, though, it has to setup a exception frame + * on stack. Because the default handler resets the register fixup handler + * the fixup handler must make sure that the default handler returns to + * it instead of the exception address, so it can re-register itself as + * the fixup handler. + * + * In case of a critical condition where the kernel cannot recover, we jump + * to unrecoverable_exception with the following entry conditions. + * All registers a0...a15 are unchanged from the last exception, except: + * + * a0: last address before we jumped to the unrecoverable_exception. + * excsave_1: a0 + * + * + * See the handle_alloca_user and spill_registers routines for example clients. + * + * FIXME: Note: we currently don't allow signal handling coming from a double + * exception, so the item markt with (*) is not required. + */ + + .section .DoubleExceptionVector.text, "ax" + .begin literal_prefix .DoubleExceptionVector + .globl _DoubleExceptionVector_WindowUnderflow + .globl _DoubleExceptionVector_WindowOverflow + +ENTRY(_DoubleExceptionVector) + + xsr a3, excsave1 + s32i a2, a3, EXC_TABLE_DOUBLE_SAVE + + /* Check for kernel double exception (usually fatal). */ + + rsr a2, ps + _bbci.l a2, PS_UM_BIT, .Lksp + + /* Check if we are currently handling a window exception. */ + /* Note: We don't need to indicate that we enter a critical section. */ + + xsr a0, depc # get DEPC, save a0 + + movi a2, WINDOW_VECTORS_VADDR + _bltu a0, a2, .Lfixup + addi a2, a2, WINDOW_VECTORS_SIZE + _bgeu a0, a2, .Lfixup + + /* Window overflow/underflow exception. Get stack pointer. */ + + l32i a2, a3, EXC_TABLE_KSTK + + /* Check for overflow/underflow exception, jump if overflow. */ + + bbci.l a0, 6, _DoubleExceptionVector_WindowOverflow + + /* + * Restart window underflow exception. + * Currently: + * depc = orig a0, + * a0 = orig DEPC, + * a2 = new sp based on KSTK from exc_table + * a3 = excsave_1 + * excsave_1 = orig a3 + * + * We return to the instruction in user space that caused the window + * underflow exception. Therefore, we change window base to the value + * before we entered the window underflow exception and prepare the + * registers to return as if we were coming from a regular exception + * by changing depc (in a0). + * Note: We can trash the current window frame (a0...a3) and depc! + */ +_DoubleExceptionVector_WindowUnderflow: + xsr a3, excsave1 + wsr a2, depc # save stack pointer temporarily + rsr a0, ps + extui a0, a0, PS_OWB_SHIFT, PS_OWB_WIDTH + wsr a0, windowbase + rsync + + /* We are now in the previous window frame. Save registers again. */ + + xsr a2, depc # save a2 and get stack pointer + s32i a0, a2, PT_AREG0 + xsr a3, excsave1 + rsr a0, exccause + s32i a0, a2, PT_DEPC # mark it as a regular exception + addx4 a0, a0, a3 + xsr a3, excsave1 + l32i a0, a0, EXC_TABLE_FAST_USER + jx a0 + + /* + * We only allow the ITLB miss exception if we are in kernel space. + * All other exceptions are unexpected and thus unrecoverable! + */ + +#ifdef CONFIG_MMU + .extern fast_second_level_miss_double_kernel + +.Lksp: /* a0: a0, a1: a1, a2: a2, a3: trashed, depc: depc, excsave: a3 */ + + rsr a3, exccause + beqi a3, EXCCAUSE_ITLB_MISS, 1f + addi a3, a3, -EXCCAUSE_DTLB_MISS + bnez a3, .Lunrecoverable +1: movi a3, fast_second_level_miss_double_kernel + jx a3 +#else +.equ .Lksp, .Lunrecoverable +#endif + + /* Critical! We can't handle this situation. PANIC! */ + + .extern unrecoverable_exception + +.Lunrecoverable_fixup: + l32i a2, a3, EXC_TABLE_DOUBLE_SAVE + xsr a0, depc + +.Lunrecoverable: + rsr a3, excsave1 + wsr a0, excsave1 + movi a0, unrecoverable_exception + callx0 a0 + +.Lfixup:/* Check for a fixup handler or if we were in a critical section. */ + + /* a0: depc, a1: a1, a2: trash, a3: exctable, depc: a0, excsave1: a3 */ + + /* Enter critical section. */ + + l32i a2, a3, EXC_TABLE_FIXUP + s32i a3, a3, EXC_TABLE_FIXUP + beq a2, a3, .Lunrecoverable_fixup # critical section + beqz a2, .Ldflt # no handler was registered + + /* a0: depc, a1: a1, a2: trash, a3: exctable, depc: a0, excsave: a3 */ + + jx a2 + +.Ldflt: /* Get stack pointer. */ + + l32i a2, a3, EXC_TABLE_DOUBLE_SAVE + addi a2, a2, -PT_USER_SIZE + + /* a0: depc, a1: a1, a2: kstk, a3: exctable, depc: a0, excsave: a3 */ + + s32i a0, a2, PT_DEPC + l32i a0, a3, EXC_TABLE_DOUBLE_SAVE + xsr a0, depc + s32i a0, a2, PT_AREG0 + + /* a0: avail, a1: a1, a2: kstk, a3: exctable, depc: a2, excsave: a3 */ + + rsr a0, exccause + addx4 a0, a0, a3 + xsr a3, excsave1 + l32i a0, a0, EXC_TABLE_FAST_USER + jx a0 + + /* + * Restart window OVERFLOW exception. + * Currently: + * depc = orig a0, + * a0 = orig DEPC, + * a2 = new sp based on KSTK from exc_table + * a3 = EXCSAVE_1 + * excsave_1 = orig a3 + * + * We return to the instruction in user space that caused the window + * overflow exception. Therefore, we change window base to the value + * before we entered the window overflow exception and prepare the + * registers to return as if we were coming from a regular exception + * by changing DEPC (in a0). + * + * NOTE: We CANNOT trash the current window frame (a0...a3), but we + * can clobber depc. + * + * The tricky part here is that overflow8 and overflow12 handlers + * save a0, then clobber a0. To restart the handler, we have to restore + * a0 if the double exception was past the point where a0 was clobbered. + * + * To keep things simple, we take advantage of the fact all overflow + * handlers save a0 in their very first instruction. If DEPC was past + * that instruction, we can safely restore a0 from where it was saved + * on the stack. + * + * a0: depc, a1: a1, a2: kstk, a3: exc_table, depc: a0, excsave1: a3 + */ +_DoubleExceptionVector_WindowOverflow: + extui a2, a0, 0, 6 # get offset into 64-byte vector handler + beqz a2, 1f # if at start of vector, don't restore + + addi a0, a0, -128 + bbsi.l a0, 8, 1f # don't restore except for overflow 8 and 12 + + /* + * This fixup handler is for the extremely unlikely case where the + * overflow handler's reference thru a0 gets a hardware TLB refill + * that bumps out the (distinct, aliasing) TLB entry that mapped its + * prior references thru a9/a13, and where our reference now thru + * a9/a13 gets a 2nd-level miss exception (not hardware TLB refill). + */ + movi a2, window_overflow_restore_a0_fixup + s32i a2, a3, EXC_TABLE_FIXUP + l32i a2, a3, EXC_TABLE_DOUBLE_SAVE + xsr a3, excsave1 + + bbsi.l a0, 7, 2f + + /* + * Restore a0 as saved by _WindowOverflow8(). + */ + + l32e a0, a9, -16 + wsr a0, depc # replace the saved a0 + j 3f + +2: + /* + * Restore a0 as saved by _WindowOverflow12(). + */ + + l32e a0, a13, -16 + wsr a0, depc # replace the saved a0 +3: + xsr a3, excsave1 + movi a0, 0 + s32i a0, a3, EXC_TABLE_FIXUP + s32i a2, a3, EXC_TABLE_DOUBLE_SAVE +1: + /* + * Restore WindowBase while leaving all address registers restored. + * We have to use ROTW for this, because WSR.WINDOWBASE requires + * an address register (which would prevent restore). + * + * Window Base goes from 0 ... 7 (Module 8) + * Window Start is 8 bits; Ex: (0b1010 1010):0x55 from series of call4s + */ + + rsr a0, ps + extui a0, a0, PS_OWB_SHIFT, PS_OWB_WIDTH + rsr a2, windowbase + sub a0, a2, a0 + extui a0, a0, 0, 3 + + l32i a2, a3, EXC_TABLE_DOUBLE_SAVE + xsr a3, excsave1 + beqi a0, 1, .L1pane + beqi a0, 3, .L3pane + + rsr a0, depc + rotw -2 + + /* + * We are now in the user code's original window frame. + * Process the exception as a user exception as if it was + * taken by the user code. + * + * This is similar to the user exception vector, + * except that PT_DEPC isn't set to EXCCAUSE. + */ +1: + xsr a3, excsave1 + wsr a2, depc + l32i a2, a3, EXC_TABLE_KSTK + s32i a0, a2, PT_AREG0 + rsr a0, exccause + + s32i a0, a2, PT_DEPC + +_DoubleExceptionVector_handle_exception: + addi a0, a0, -EXCCAUSE_UNALIGNED + beqz a0, 2f + addx4 a0, a0, a3 + l32i a0, a0, EXC_TABLE_FAST_USER + 4 * EXCCAUSE_UNALIGNED + xsr a3, excsave1 + jx a0 +2: + movi a0, user_exception + xsr a3, excsave1 + jx a0 + +.L1pane: + rsr a0, depc + rotw -1 + j 1b + +.L3pane: + rsr a0, depc + rotw -3 + j 1b + + +ENDPROC(_DoubleExceptionVector) + +/* + * Fixup handler for TLB miss in double exception handler for window owerflow. + * We get here with windowbase set to the window that was being spilled and + * a0 trashed. a0 bit 7 determines if this is a call8 (bit clear) or call12 + * (bit set) window. + * + * We do the following here: + * - go to the original window retaining a0 value; + * - set up exception stack to return back to appropriate a0 restore code + * (we'll need to rotate window back and there's no place to save this + * information, use different return address for that); + * - handle the exception; + * - go to the window that was being spilled; + * - set up window_overflow_restore_a0_fixup as a fixup routine; + * - reload a0; + * - restore the original window; + * - reset the default fixup routine; + * - return to user. By the time we get to this fixup handler all information + * about the conditions of the original double exception that happened in + * the window overflow handler is lost, so we just return to userspace to + * retry overflow from start. + * + * a0: value of depc, original value in depc + * a2: trashed, original value in EXC_TABLE_DOUBLE_SAVE + * a3: exctable, original value in excsave1 + */ + +ENTRY(window_overflow_restore_a0_fixup) + + rsr a0, ps + extui a0, a0, PS_OWB_SHIFT, PS_OWB_WIDTH + rsr a2, windowbase + sub a0, a2, a0 + extui a0, a0, 0, 3 + l32i a2, a3, EXC_TABLE_DOUBLE_SAVE + xsr a3, excsave1 + + _beqi a0, 1, .Lhandle_1 + _beqi a0, 3, .Lhandle_3 + + .macro overflow_fixup_handle_exception_pane n + + rsr a0, depc + rotw -\n + + xsr a3, excsave1 + wsr a2, depc + l32i a2, a3, EXC_TABLE_KSTK + s32i a0, a2, PT_AREG0 + + movi a0, .Lrestore_\n + s32i a0, a2, PT_DEPC + rsr a0, exccause + j _DoubleExceptionVector_handle_exception + + .endm + + overflow_fixup_handle_exception_pane 2 +.Lhandle_1: + overflow_fixup_handle_exception_pane 1 +.Lhandle_3: + overflow_fixup_handle_exception_pane 3 + + .macro overflow_fixup_restore_a0_pane n + + rotw \n + /* Need to preserve a0 value here to be able to handle exception + * that may occur on a0 reload from stack. It may occur because + * TLB miss handler may not be atomic and pointer to page table + * may be lost before we get here. There are no free registers, + * so we need to use EXC_TABLE_DOUBLE_SAVE area. + */ + xsr a3, excsave1 + s32i a2, a3, EXC_TABLE_DOUBLE_SAVE + movi a2, window_overflow_restore_a0_fixup + s32i a2, a3, EXC_TABLE_FIXUP + l32i a2, a3, EXC_TABLE_DOUBLE_SAVE + xsr a3, excsave1 + bbsi.l a0, 7, 1f + l32e a0, a9, -16 + j 2f +1: + l32e a0, a13, -16 +2: + rotw -\n + + .endm + +.Lrestore_2: + overflow_fixup_restore_a0_pane 2 + +.Lset_default_fixup: + xsr a3, excsave1 + s32i a2, a3, EXC_TABLE_DOUBLE_SAVE + movi a2, 0 + s32i a2, a3, EXC_TABLE_FIXUP + l32i a2, a3, EXC_TABLE_DOUBLE_SAVE + xsr a3, excsave1 + rfe + +.Lrestore_1: + overflow_fixup_restore_a0_pane 1 + j .Lset_default_fixup +.Lrestore_3: + overflow_fixup_restore_a0_pane 3 + j .Lset_default_fixup + +ENDPROC(window_overflow_restore_a0_fixup) + + .end literal_prefix +/* + * Debug interrupt vector + * + * There is not much space here, so simply jump to another handler. + * EXCSAVE[DEBUGLEVEL] has been set to that handler. + */ + + .section .DebugInterruptVector.text, "ax" + +ENTRY(_DebugInterruptVector) + + xsr a0, SREG_EXCSAVE + XCHAL_DEBUGLEVEL + jx a0 + +ENDPROC(_DebugInterruptVector) + + + +/* + * Medium priority level interrupt vectors + * + * Each takes less than 16 (0x10) bytes, no literals, by placing + * the extra 8 bytes that would otherwise be required in the window + * vectors area where there is space. With relocatable vectors, + * all vectors are within ~ 4 kB range of each other, so we can + * simply jump (J) to another vector without having to use JX. + * + * common_exception code gets current IRQ level in PS.INTLEVEL + * and preserves it for the IRQ handling time. + */ + + .macro irq_entry_level level + + .if XCHAL_EXCM_LEVEL >= \level + .section .Level\level\()InterruptVector.text, "ax" +ENTRY(_Level\level\()InterruptVector) + wsr a0, excsave2 + rsr a0, epc\level + wsr a0, epc1 + movi a0, EXCCAUSE_LEVEL1_INTERRUPT + wsr a0, exccause + rsr a0, eps\level + # branch to user or kernel vector + j _SimulateUserKernelVectorException + .endif + + .endm + + irq_entry_level 2 + irq_entry_level 3 + irq_entry_level 4 + irq_entry_level 5 + irq_entry_level 6 + + +/* Window overflow and underflow handlers. + * The handlers must be 64 bytes apart, first starting with the underflow + * handlers underflow-4 to underflow-12, then the overflow handlers + * overflow-4 to overflow-12. + * + * Note: We rerun the underflow handlers if we hit an exception, so + * we try to access any page that would cause a page fault early. + */ + +#define ENTRY_ALIGN64(name) \ + .globl name; \ + .align 64; \ + name: + + .section .WindowVectors.text, "ax" + + +/* 4-Register Window Overflow Vector (Handler) */ + +ENTRY_ALIGN64(_WindowOverflow4) + + s32e a0, a5, -16 + s32e a1, a5, -12 + s32e a2, a5, -8 + s32e a3, a5, -4 + rfwo + +ENDPROC(_WindowOverflow4) + + +#if XCHAL_EXCM_LEVEL >= 2 + /* Not a window vector - but a convenient location + * (where we know there's space) for continuation of + * medium priority interrupt dispatch code. + * On entry here, a0 contains PS, and EPC2 contains saved a0: + */ + .align 4 +_SimulateUserKernelVectorException: + addi a0, a0, (1 << PS_EXCM_BIT) + wsr a0, ps + bbsi.l a0, PS_UM_BIT, 1f # branch if user mode + rsr a0, excsave2 # restore a0 + j _KernelExceptionVector # simulate kernel vector exception +1: rsr a0, excsave2 # restore a0 + j _UserExceptionVector # simulate user vector exception +#endif + + +/* 4-Register Window Underflow Vector (Handler) */ + +ENTRY_ALIGN64(_WindowUnderflow4) + + l32e a0, a5, -16 + l32e a1, a5, -12 + l32e a2, a5, -8 + l32e a3, a5, -4 + rfwu + +ENDPROC(_WindowUnderflow4) + +/* 8-Register Window Overflow Vector (Handler) */ + +ENTRY_ALIGN64(_WindowOverflow8) + + s32e a0, a9, -16 + l32e a0, a1, -12 + s32e a2, a9, -8 + s32e a1, a9, -12 + s32e a3, a9, -4 + s32e a4, a0, -32 + s32e a5, a0, -28 + s32e a6, a0, -24 + s32e a7, a0, -20 + rfwo + +ENDPROC(_WindowOverflow8) + +/* 8-Register Window Underflow Vector (Handler) */ + +ENTRY_ALIGN64(_WindowUnderflow8) + + l32e a1, a9, -12 + l32e a0, a9, -16 + l32e a7, a1, -12 + l32e a2, a9, -8 + l32e a4, a7, -32 + l32e a3, a9, -4 + l32e a5, a7, -28 + l32e a6, a7, -24 + l32e a7, a7, -20 + rfwu + +ENDPROC(_WindowUnderflow8) + +/* 12-Register Window Overflow Vector (Handler) */ + +ENTRY_ALIGN64(_WindowOverflow12) + + s32e a0, a13, -16 + l32e a0, a1, -12 + s32e a1, a13, -12 + s32e a2, a13, -8 + s32e a3, a13, -4 + s32e a4, a0, -48 + s32e a5, a0, -44 + s32e a6, a0, -40 + s32e a7, a0, -36 + s32e a8, a0, -32 + s32e a9, a0, -28 + s32e a10, a0, -24 + s32e a11, a0, -20 + rfwo + +ENDPROC(_WindowOverflow12) + +/* 12-Register Window Underflow Vector (Handler) */ + +ENTRY_ALIGN64(_WindowUnderflow12) + + l32e a1, a13, -12 + l32e a0, a13, -16 + l32e a11, a1, -12 + l32e a2, a13, -8 + l32e a4, a11, -48 + l32e a8, a11, -32 + l32e a3, a13, -4 + l32e a5, a11, -44 + l32e a6, a11, -40 + l32e a7, a11, -36 + l32e a9, a11, -28 + l32e a10, a11, -24 + l32e a11, a11, -20 + rfwu + +ENDPROC(_WindowUnderflow12) + + .text diff --git a/arch/xtensa/kernel/vmlinux.lds.S b/arch/xtensa/kernel/vmlinux.lds.S new file mode 100644 index 000000000..fc1bc2ba8 --- /dev/null +++ b/arch/xtensa/kernel/vmlinux.lds.S @@ -0,0 +1,370 @@ +/* + * arch/xtensa/kernel/vmlinux.lds.S + * + * Xtensa linker script + * + * This file is subject to the terms and conditions of the GNU General Public + * License. See the file "COPYING" in the main directory of this archive + * for more details. + * + * Copyright (C) 2001 - 2008 Tensilica Inc. + * + * Chris Zankel <chris@zankel.net> + * Marc Gauthier <marc@tensilica.com, marc@alumni.uwaterloo.ca> + * Joe Taylor <joe@tensilica.com, joetylr@yahoo.com> + */ + +#include <asm-generic/vmlinux.lds.h> +#include <asm/page.h> +#include <asm/thread_info.h> + +#include <asm/vectors.h> +#include <variant/core.h> +#include <platform/hardware.h> +OUTPUT_ARCH(xtensa) +ENTRY(_start) + +#ifdef __XTENSA_EB__ +jiffies = jiffies_64 + 4; +#else +jiffies = jiffies_64; +#endif + +#ifndef KERNELOFFSET +#define KERNELOFFSET 0xd0003000 +#endif + +/* Note: In the following macros, it would be nice to specify only the + vector name and section kind and construct "sym" and "section" using + CPP concatenation, but that does not work reliably. Concatenating a + string with "." produces an invalid token. CPP will not print a + warning because it thinks this is an assembly file, but it leaves + them as multiple tokens and there may or may not be whitespace + between them. */ + +/* Macro for a relocation entry */ + +#define RELOCATE_ENTRY(sym, section) \ + LONG(sym ## _start); \ + LONG(sym ## _end); \ + LONG(LOADADDR(section)) + +/* Macro to define a section for a vector. + * + * Use of the MIN function catches the types of errors illustrated in + * the following example: + * + * Assume the section .DoubleExceptionVector.literal is completely + * full. Then a programmer adds code to .DoubleExceptionVector.text + * that produces another literal. The final literal position will + * overlay onto the first word of the adjacent code section + * .DoubleExceptionVector.text. (In practice, the literals will + * overwrite the code, and the first few instructions will be + * garbage.) + */ + +#define SECTION_VECTOR(sym, section, addr, max_prevsec_size, prevsec) \ + section addr : AT((MIN(LOADADDR(prevsec) + max_prevsec_size, \ + LOADADDR(prevsec) + SIZEOF(prevsec)) + 3) & ~ 3) \ + { \ + . = ALIGN(4); \ + sym ## _start = ABSOLUTE(.); \ + *(section) \ + sym ## _end = ABSOLUTE(.); \ + } + +/* + * Mapping of input sections to output sections when linking. + */ + +SECTIONS +{ + . = KERNELOFFSET; + /* .text section */ + + _text = .; + _stext = .; + + .text : + { + /* The HEAD_TEXT section must be the first section! */ + HEAD_TEXT + TEXT_TEXT + VMLINUX_SYMBOL(__sched_text_start) = .; + *(.sched.literal .sched.text) + VMLINUX_SYMBOL(__sched_text_end) = .; + VMLINUX_SYMBOL(__lock_text_start) = .; + *(.spinlock.literal .spinlock.text) + VMLINUX_SYMBOL(__lock_text_end) = .; + + } + _etext = .; + PROVIDE (etext = .); + + . = ALIGN(16); + + RODATA + + /* Relocation table */ + + .fixup : { *(.fixup) } + + EXCEPTION_TABLE(16) + /* Data section */ + + _sdata = .; + RW_DATA_SECTION(XCHAL_ICACHE_LINESIZE, PAGE_SIZE, THREAD_SIZE) + _edata = .; + + /* Initialization code and data: */ + + . = ALIGN(PAGE_SIZE); + __init_begin = .; + INIT_TEXT_SECTION(PAGE_SIZE) + + .init.data : + { + INIT_DATA + . = ALIGN(0x4); + __tagtable_begin = .; + *(.taglist) + __tagtable_end = .; + + . = ALIGN(16); + __boot_reloc_table_start = ABSOLUTE(.); + + RELOCATE_ENTRY(_WindowVectors_text, + .WindowVectors.text); +#if XCHAL_EXCM_LEVEL >= 2 + RELOCATE_ENTRY(_Level2InterruptVector_text, + .Level2InterruptVector.text); +#endif +#if XCHAL_EXCM_LEVEL >= 3 + RELOCATE_ENTRY(_Level3InterruptVector_text, + .Level3InterruptVector.text); +#endif +#if XCHAL_EXCM_LEVEL >= 4 + RELOCATE_ENTRY(_Level4InterruptVector_text, + .Level4InterruptVector.text); +#endif +#if XCHAL_EXCM_LEVEL >= 5 + RELOCATE_ENTRY(_Level5InterruptVector_text, + .Level5InterruptVector.text); +#endif +#if XCHAL_EXCM_LEVEL >= 6 + RELOCATE_ENTRY(_Level6InterruptVector_text, + .Level6InterruptVector.text); +#endif + RELOCATE_ENTRY(_KernelExceptionVector_text, + .KernelExceptionVector.text); + RELOCATE_ENTRY(_UserExceptionVector_text, + .UserExceptionVector.text); + RELOCATE_ENTRY(_DoubleExceptionVector_literal, + .DoubleExceptionVector.literal); + RELOCATE_ENTRY(_DoubleExceptionVector_text, + .DoubleExceptionVector.text); + RELOCATE_ENTRY(_DebugInterruptVector_text, + .DebugInterruptVector.text); +#if defined(CONFIG_SMP) + RELOCATE_ENTRY(_SecondaryResetVector_literal, + .SecondaryResetVector.literal); + RELOCATE_ENTRY(_SecondaryResetVector_text, + .SecondaryResetVector.text); +#endif + + + __boot_reloc_table_end = ABSOLUTE(.) ; + + INIT_SETUP(XCHAL_ICACHE_LINESIZE) + INIT_CALLS + CON_INITCALL + SECURITY_INITCALL + INIT_RAM_FS + } + + PERCPU_SECTION(XCHAL_ICACHE_LINESIZE) + + /* We need this dummy segment here */ + + . = ALIGN(4); + .dummy : { LONG(0) } + + /* The vectors are relocated to the real position at startup time */ + + SECTION_VECTOR (_WindowVectors_text, + .WindowVectors.text, + WINDOW_VECTORS_VADDR, 4, + .dummy) + SECTION_VECTOR (_DebugInterruptVector_literal, + .DebugInterruptVector.literal, + DEBUG_VECTOR_VADDR - 4, + SIZEOF(.WindowVectors.text), + .WindowVectors.text) + SECTION_VECTOR (_DebugInterruptVector_text, + .DebugInterruptVector.text, + DEBUG_VECTOR_VADDR, + 4, + .DebugInterruptVector.literal) +#undef LAST +#define LAST .DebugInterruptVector.text +#if XCHAL_EXCM_LEVEL >= 2 + SECTION_VECTOR (_Level2InterruptVector_text, + .Level2InterruptVector.text, + INTLEVEL2_VECTOR_VADDR, + SIZEOF(LAST), LAST) +# undef LAST +# define LAST .Level2InterruptVector.text +#endif +#if XCHAL_EXCM_LEVEL >= 3 + SECTION_VECTOR (_Level3InterruptVector_text, + .Level3InterruptVector.text, + INTLEVEL3_VECTOR_VADDR, + SIZEOF(LAST), LAST) +# undef LAST +# define LAST .Level3InterruptVector.text +#endif +#if XCHAL_EXCM_LEVEL >= 4 + SECTION_VECTOR (_Level4InterruptVector_text, + .Level4InterruptVector.text, + INTLEVEL4_VECTOR_VADDR, + SIZEOF(LAST), LAST) +# undef LAST +# define LAST .Level4InterruptVector.text +#endif +#if XCHAL_EXCM_LEVEL >= 5 + SECTION_VECTOR (_Level5InterruptVector_text, + .Level5InterruptVector.text, + INTLEVEL5_VECTOR_VADDR, + SIZEOF(LAST), LAST) +# undef LAST +# define LAST .Level5InterruptVector.text +#endif +#if XCHAL_EXCM_LEVEL >= 6 + SECTION_VECTOR (_Level6InterruptVector_text, + .Level6InterruptVector.text, + INTLEVEL6_VECTOR_VADDR, + SIZEOF(LAST), LAST) +# undef LAST +# define LAST .Level6InterruptVector.text +#endif + SECTION_VECTOR (_KernelExceptionVector_literal, + .KernelExceptionVector.literal, + KERNEL_VECTOR_VADDR - 4, + SIZEOF(LAST), LAST) +#undef LAST + SECTION_VECTOR (_KernelExceptionVector_text, + .KernelExceptionVector.text, + KERNEL_VECTOR_VADDR, + 4, + .KernelExceptionVector.literal) + SECTION_VECTOR (_UserExceptionVector_literal, + .UserExceptionVector.literal, + USER_VECTOR_VADDR - 4, + SIZEOF(.KernelExceptionVector.text), + .KernelExceptionVector.text) + SECTION_VECTOR (_UserExceptionVector_text, + .UserExceptionVector.text, + USER_VECTOR_VADDR, + 4, + .UserExceptionVector.literal) + SECTION_VECTOR (_DoubleExceptionVector_literal, + .DoubleExceptionVector.literal, + DOUBLEEXC_VECTOR_VADDR - 48, + SIZEOF(.UserExceptionVector.text), + .UserExceptionVector.text) + SECTION_VECTOR (_DoubleExceptionVector_text, + .DoubleExceptionVector.text, + DOUBLEEXC_VECTOR_VADDR, + 48, + .DoubleExceptionVector.literal) + + . = (LOADADDR( .DoubleExceptionVector.text ) + SIZEOF( .DoubleExceptionVector.text ) + 3) & ~ 3; + +#if defined(CONFIG_SMP) + + SECTION_VECTOR (_SecondaryResetVector_literal, + .SecondaryResetVector.literal, + RESET_VECTOR1_VADDR - 4, + SIZEOF(.DoubleExceptionVector.text), + .DoubleExceptionVector.text) + + SECTION_VECTOR (_SecondaryResetVector_text, + .SecondaryResetVector.text, + RESET_VECTOR1_VADDR, + 4, + .SecondaryResetVector.literal) + + . = LOADADDR(.SecondaryResetVector.text)+SIZEOF(.SecondaryResetVector.text); + +#endif + + . = ALIGN(PAGE_SIZE); + + __init_end = .; + + BSS_SECTION(0, 8192, 0) + + _end = .; + + /* only used by the boot loader */ + + . = ALIGN(0x10); + .bootstrap : { *(.bootstrap.literal .bootstrap.text .bootstrap.data) } + + .ResetVector.text RESET_VECTOR_VADDR : + { + *(.ResetVector.text) + } + + + /* + * This is a remapped copy of the Secondary Reset Vector Code. + * It keeps gdb in sync with the PC after switching + * to the temporary mapping used while setting up + * the V2 MMU mappings for Linux. + * + * Only debug information about this section is put in the kernel image. + */ + .SecondaryResetVector.remapped_text 0x46000000 (INFO): + { + *(.SecondaryResetVector.remapped_text) + } + + + .xt.lit : { *(.xt.lit) } + .xt.prop : { *(.xt.prop) } + + .debug 0 : { *(.debug) } + .line 0 : { *(.line) } + .debug_srcinfo 0 : { *(.debug_srcinfo) } + .debug_sfnames 0 : { *(.debug_sfnames) } + .debug_aranges 0 : { *(.debug_aranges) } + .debug_pubnames 0 : { *(.debug_pubnames) } + .debug_info 0 : { *(.debug_info) } + .debug_abbrev 0 : { *(.debug_abbrev) } + .debug_line 0 : { *(.debug_line) } + .debug_frame 0 : { *(.debug_frame) } + .debug_str 0 : { *(.debug_str) } + .debug_loc 0 : { *(.debug_loc) } + .debug_macinfo 0 : { *(.debug_macinfo) } + .debug_weaknames 0 : { *(.debug_weaknames) } + .debug_funcnames 0 : { *(.debug_funcnames) } + .debug_typenames 0 : { *(.debug_typenames) } + .debug_varnames 0 : { *(.debug_varnames) } + + .xt.insn 0 : + { + *(.xt.insn) + *(.gnu.linkonce.x*) + } + + .xt.lit 0 : + { + *(.xt.lit) + *(.gnu.linkonce.p*) + } + + /* Sections to be discarded */ + DISCARDS + /DISCARD/ : { *(.exit.literal) } +} diff --git a/arch/xtensa/kernel/xtensa_ksyms.c b/arch/xtensa/kernel/xtensa_ksyms.c new file mode 100644 index 000000000..4d2872fd9 --- /dev/null +++ b/arch/xtensa/kernel/xtensa_ksyms.c @@ -0,0 +1,136 @@ +/* + * arch/xtensa/kernel/xtensa_ksyms.c + * + * Export Xtensa-specific functions for loadable modules. + * + * This file is subject to the terms and conditions of the GNU General Public + * License. See the file "COPYING" in the main directory of this archive + * for more details. + * + * Copyright (C) 2001 - 2005 Tensilica Inc. + * + * Joe Taylor <joe@tensilica.com> + */ + +#include <linux/module.h> +#include <linux/string.h> +#include <linux/mm.h> +#include <linux/interrupt.h> +#include <asm/irq.h> +#include <linux/in6.h> + +#include <asm/uaccess.h> +#include <asm/cacheflush.h> +#include <asm/checksum.h> +#include <asm/dma.h> +#include <asm/io.h> +#include <asm/page.h> +#include <asm/pgalloc.h> +#include <asm/ftrace.h> +#ifdef CONFIG_BLK_DEV_FD +#include <asm/floppy.h> +#endif +#ifdef CONFIG_NET +#include <net/checksum.h> +#endif /* CONFIG_NET */ + + +/* + * String functions + */ +EXPORT_SYMBOL(memset); +EXPORT_SYMBOL(memcpy); +EXPORT_SYMBOL(memmove); +EXPORT_SYMBOL(__strncpy_user); +EXPORT_SYMBOL(clear_page); +EXPORT_SYMBOL(copy_page); + +EXPORT_SYMBOL(empty_zero_page); + +/* + * gcc internal math functions + */ +extern long long __ashrdi3(long long, int); +extern long long __ashldi3(long long, int); +extern long long __lshrdi3(long long, int); +extern int __divsi3(int, int); +extern int __modsi3(int, int); +extern long long __muldi3(long long, long long); +extern int __mulsi3(int, int); +extern unsigned int __udivsi3(unsigned int, unsigned int); +extern unsigned int __umodsi3(unsigned int, unsigned int); +extern unsigned long long __umoddi3(unsigned long long, unsigned long long); +extern unsigned long long __udivdi3(unsigned long long, unsigned long long); +extern int __ucmpdi2(int, int); + +EXPORT_SYMBOL(__ashldi3); +EXPORT_SYMBOL(__ashrdi3); +EXPORT_SYMBOL(__lshrdi3); +EXPORT_SYMBOL(__divsi3); +EXPORT_SYMBOL(__modsi3); +EXPORT_SYMBOL(__muldi3); +EXPORT_SYMBOL(__mulsi3); +EXPORT_SYMBOL(__udivsi3); +EXPORT_SYMBOL(__umodsi3); +EXPORT_SYMBOL(__udivdi3); +EXPORT_SYMBOL(__umoddi3); +EXPORT_SYMBOL(__ucmpdi2); + +void __xtensa_libgcc_window_spill(void) +{ + BUG(); +} +EXPORT_SYMBOL(__xtensa_libgcc_window_spill); + +unsigned long __sync_fetch_and_and_4(unsigned long *p, unsigned long v) +{ + BUG(); +} +EXPORT_SYMBOL(__sync_fetch_and_and_4); + +unsigned long __sync_fetch_and_or_4(unsigned long *p, unsigned long v) +{ + BUG(); +} +EXPORT_SYMBOL(__sync_fetch_and_or_4); + +#ifdef CONFIG_NET +/* + * Networking support + */ +EXPORT_SYMBOL(csum_partial); +EXPORT_SYMBOL(csum_partial_copy_generic); +#endif /* CONFIG_NET */ + +/* + * Architecture-specific symbols + */ +EXPORT_SYMBOL(__xtensa_copy_user); +EXPORT_SYMBOL(__invalidate_icache_range); + +/* + * Kernel hacking ... + */ + +#if defined(CONFIG_VGA_CONSOLE) || defined(CONFIG_DUMMY_CONSOLE) +// FIXME EXPORT_SYMBOL(screen_info); +#endif + +EXPORT_SYMBOL(outsb); +EXPORT_SYMBOL(outsw); +EXPORT_SYMBOL(outsl); +EXPORT_SYMBOL(insb); +EXPORT_SYMBOL(insw); +EXPORT_SYMBOL(insl); + +extern long common_exception_return; +EXPORT_SYMBOL(common_exception_return); + +#ifdef CONFIG_FUNCTION_TRACER +EXPORT_SYMBOL(_mcount); +#endif + +EXPORT_SYMBOL(__invalidate_dcache_range); +#if XCHAL_DCACHE_IS_WRITEBACK +EXPORT_SYMBOL(__flush_dcache_range); +#endif |