summaryrefslogtreecommitdiff
path: root/arch/arm/kernel/entry-armv.S
diff options
context:
space:
mode:
authorAndré Fabian Silva Delgado <emulatorman@parabola.nu>2015-08-05 17:04:01 -0300
committerAndré Fabian Silva Delgado <emulatorman@parabola.nu>2015-08-05 17:04:01 -0300
commit57f0f512b273f60d52568b8c6b77e17f5636edc0 (patch)
tree5e910f0e82173f4ef4f51111366a3f1299037a7b /arch/arm/kernel/entry-armv.S
Initial import
Diffstat (limited to 'arch/arm/kernel/entry-armv.S')
-rw-r--r--arch/arm/kernel/entry-armv.S1238
1 files changed, 1238 insertions, 0 deletions
diff --git a/arch/arm/kernel/entry-armv.S b/arch/arm/kernel/entry-armv.S
new file mode 100644
index 000000000..570306c49
--- /dev/null
+++ b/arch/arm/kernel/entry-armv.S
@@ -0,0 +1,1238 @@
+/*
+ * linux/arch/arm/kernel/entry-armv.S
+ *
+ * Copyright (C) 1996,1997,1998 Russell King.
+ * ARM700 fix by Matthew Godbolt (linux-user@willothewisp.demon.co.uk)
+ * nommu support by Hyok S. Choi (hyok.choi@samsung.com)
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * Low-level vector interface routines
+ *
+ * Note: there is a StrongARM bug in the STMIA rn, {regs}^ instruction
+ * that causes it to save wrong values... Be aware!
+ */
+
+#include <asm/assembler.h>
+#include <asm/memory.h>
+#include <asm/glue-df.h>
+#include <asm/glue-pf.h>
+#include <asm/vfpmacros.h>
+#ifndef CONFIG_MULTI_IRQ_HANDLER
+#include <mach/entry-macro.S>
+#endif
+#include <asm/thread_notify.h>
+#include <asm/unwind.h>
+#include <asm/unistd.h>
+#include <asm/tls.h>
+#include <asm/system_info.h>
+
+#include "entry-header.S"
+#include <asm/entry-macro-multi.S>
+#include <asm/probes.h>
+
+/*
+ * Interrupt handling.
+ */
+ .macro irq_handler
+#ifdef CONFIG_MULTI_IRQ_HANDLER
+ ldr r1, =handle_arch_irq
+ mov r0, sp
+ adr lr, BSYM(9997f)
+ ldr pc, [r1]
+#else
+ arch_irq_handler_default
+#endif
+9997:
+ .endm
+
+ .macro pabt_helper
+ @ PABORT handler takes pt_regs in r2, fault address in r4 and psr in r5
+#ifdef MULTI_PABORT
+ ldr ip, .LCprocfns
+ mov lr, pc
+ ldr pc, [ip, #PROCESSOR_PABT_FUNC]
+#else
+ bl CPU_PABORT_HANDLER
+#endif
+ .endm
+
+ .macro dabt_helper
+
+ @
+ @ Call the processor-specific abort handler:
+ @
+ @ r2 - pt_regs
+ @ r4 - aborted context pc
+ @ r5 - aborted context psr
+ @
+ @ The abort handler must return the aborted address in r0, and
+ @ the fault status register in r1. r9 must be preserved.
+ @
+#ifdef MULTI_DABORT
+ ldr ip, .LCprocfns
+ mov lr, pc
+ ldr pc, [ip, #PROCESSOR_DABT_FUNC]
+#else
+ bl CPU_DABORT_HANDLER
+#endif
+ .endm
+
+#ifdef CONFIG_KPROBES
+ .section .kprobes.text,"ax",%progbits
+#else
+ .text
+#endif
+
+/*
+ * Invalid mode handlers
+ */
+ .macro inv_entry, reason
+ sub sp, sp, #S_FRAME_SIZE
+ ARM( stmib sp, {r1 - lr} )
+ THUMB( stmia sp, {r0 - r12} )
+ THUMB( str sp, [sp, #S_SP] )
+ THUMB( str lr, [sp, #S_LR] )
+ mov r1, #\reason
+ .endm
+
+__pabt_invalid:
+ inv_entry BAD_PREFETCH
+ b common_invalid
+ENDPROC(__pabt_invalid)
+
+__dabt_invalid:
+ inv_entry BAD_DATA
+ b common_invalid
+ENDPROC(__dabt_invalid)
+
+__irq_invalid:
+ inv_entry BAD_IRQ
+ b common_invalid
+ENDPROC(__irq_invalid)
+
+__und_invalid:
+ inv_entry BAD_UNDEFINSTR
+
+ @
+ @ XXX fall through to common_invalid
+ @
+
+@
+@ common_invalid - generic code for failed exception (re-entrant version of handlers)
+@
+common_invalid:
+ zero_fp
+
+ ldmia r0, {r4 - r6}
+ add r0, sp, #S_PC @ here for interlock avoidance
+ mov r7, #-1 @ "" "" "" ""
+ str r4, [sp] @ save preserved r0
+ stmia r0, {r5 - r7} @ lr_<exception>,
+ @ cpsr_<exception>, "old_r0"
+
+ mov r0, sp
+ b bad_mode
+ENDPROC(__und_invalid)
+
+/*
+ * SVC mode handlers
+ */
+
+#if defined(CONFIG_AEABI) && (__LINUX_ARM_ARCH__ >= 5)
+#define SPFIX(code...) code
+#else
+#define SPFIX(code...)
+#endif
+
+ .macro svc_entry, stack_hole=0, trace=1
+ UNWIND(.fnstart )
+ UNWIND(.save {r0 - pc} )
+ sub sp, sp, #(S_FRAME_SIZE + \stack_hole - 4)
+#ifdef CONFIG_THUMB2_KERNEL
+ SPFIX( str r0, [sp] ) @ temporarily saved
+ SPFIX( mov r0, sp )
+ SPFIX( tst r0, #4 ) @ test original stack alignment
+ SPFIX( ldr r0, [sp] ) @ restored
+#else
+ SPFIX( tst sp, #4 )
+#endif
+ SPFIX( subeq sp, sp, #4 )
+ stmia sp, {r1 - r12}
+
+ ldmia r0, {r3 - r5}
+ add r7, sp, #S_SP - 4 @ here for interlock avoidance
+ mov r6, #-1 @ "" "" "" ""
+ add r2, sp, #(S_FRAME_SIZE + \stack_hole - 4)
+ SPFIX( addeq r2, r2, #4 )
+ str r3, [sp, #-4]! @ save the "real" r0 copied
+ @ from the exception stack
+
+ mov r3, lr
+
+ @
+ @ We are now ready to fill in the remaining blanks on the stack:
+ @
+ @ r2 - sp_svc
+ @ r3 - lr_svc
+ @ r4 - lr_<exception>, already fixed up for correct return/restart
+ @ r5 - spsr_<exception>
+ @ r6 - orig_r0 (see pt_regs definition in ptrace.h)
+ @
+ stmia r7, {r2 - r6}
+
+ .if \trace
+#ifdef CONFIG_TRACE_IRQFLAGS
+ bl trace_hardirqs_off
+#endif
+ .endif
+ .endm
+
+ .align 5
+__dabt_svc:
+ svc_entry
+ mov r2, sp
+ dabt_helper
+ THUMB( ldr r5, [sp, #S_PSR] ) @ potentially updated CPSR
+ svc_exit r5 @ return from exception
+ UNWIND(.fnend )
+ENDPROC(__dabt_svc)
+
+ .align 5
+__irq_svc:
+ svc_entry
+ irq_handler
+
+#ifdef CONFIG_PREEMPT
+ get_thread_info tsk
+ ldr r8, [tsk, #TI_PREEMPT] @ get preempt count
+ ldr r0, [tsk, #TI_FLAGS] @ get flags
+ teq r8, #0 @ if preempt count != 0
+ movne r0, #0 @ force flags to 0
+ tst r0, #_TIF_NEED_RESCHED
+ blne svc_preempt
+#endif
+
+ svc_exit r5, irq = 1 @ return from exception
+ UNWIND(.fnend )
+ENDPROC(__irq_svc)
+
+ .ltorg
+
+#ifdef CONFIG_PREEMPT
+svc_preempt:
+ mov r8, lr
+1: bl preempt_schedule_irq @ irq en/disable is done inside
+ ldr r0, [tsk, #TI_FLAGS] @ get new tasks TI_FLAGS
+ tst r0, #_TIF_NEED_RESCHED
+ reteq r8 @ go again
+ b 1b
+#endif
+
+__und_fault:
+ @ Correct the PC such that it is pointing at the instruction
+ @ which caused the fault. If the faulting instruction was ARM
+ @ the PC will be pointing at the next instruction, and have to
+ @ subtract 4. Otherwise, it is Thumb, and the PC will be
+ @ pointing at the second half of the Thumb instruction. We
+ @ have to subtract 2.
+ ldr r2, [r0, #S_PC]
+ sub r2, r2, r1
+ str r2, [r0, #S_PC]
+ b do_undefinstr
+ENDPROC(__und_fault)
+
+ .align 5
+__und_svc:
+#ifdef CONFIG_KPROBES
+ @ If a kprobe is about to simulate a "stmdb sp..." instruction,
+ @ it obviously needs free stack space which then will belong to
+ @ the saved context.
+ svc_entry MAX_STACK_SIZE
+#else
+ svc_entry
+#endif
+ @
+ @ call emulation code, which returns using r9 if it has emulated
+ @ the instruction, or the more conventional lr if we are to treat
+ @ this as a real undefined instruction
+ @
+ @ r0 - instruction
+ @
+#ifndef CONFIG_THUMB2_KERNEL
+ ldr r0, [r4, #-4]
+#else
+ mov r1, #2
+ ldrh r0, [r4, #-2] @ Thumb instruction at LR - 2
+ cmp r0, #0xe800 @ 32-bit instruction if xx >= 0
+ blo __und_svc_fault
+ ldrh r9, [r4] @ bottom 16 bits
+ add r4, r4, #2
+ str r4, [sp, #S_PC]
+ orr r0, r9, r0, lsl #16
+#endif
+ adr r9, BSYM(__und_svc_finish)
+ mov r2, r4
+ bl call_fpe
+
+ mov r1, #4 @ PC correction to apply
+__und_svc_fault:
+ mov r0, sp @ struct pt_regs *regs
+ bl __und_fault
+
+__und_svc_finish:
+ ldr r5, [sp, #S_PSR] @ Get SVC cpsr
+ svc_exit r5 @ return from exception
+ UNWIND(.fnend )
+ENDPROC(__und_svc)
+
+ .align 5
+__pabt_svc:
+ svc_entry
+ mov r2, sp @ regs
+ pabt_helper
+ svc_exit r5 @ return from exception
+ UNWIND(.fnend )
+ENDPROC(__pabt_svc)
+
+ .align 5
+__fiq_svc:
+ svc_entry trace=0
+ mov r0, sp @ struct pt_regs *regs
+ bl handle_fiq_as_nmi
+ svc_exit_via_fiq
+ UNWIND(.fnend )
+ENDPROC(__fiq_svc)
+
+ .align 5
+.LCcralign:
+ .word cr_alignment
+#ifdef MULTI_DABORT
+.LCprocfns:
+ .word processor
+#endif
+.LCfp:
+ .word fp_enter
+
+/*
+ * Abort mode handlers
+ */
+
+@
+@ Taking a FIQ in abort mode is similar to taking a FIQ in SVC mode
+@ and reuses the same macros. However in abort mode we must also
+@ save/restore lr_abt and spsr_abt to make nested aborts safe.
+@
+ .align 5
+__fiq_abt:
+ svc_entry trace=0
+
+ ARM( msr cpsr_c, #ABT_MODE | PSR_I_BIT | PSR_F_BIT )
+ THUMB( mov r0, #ABT_MODE | PSR_I_BIT | PSR_F_BIT )
+ THUMB( msr cpsr_c, r0 )
+ mov r1, lr @ Save lr_abt
+ mrs r2, spsr @ Save spsr_abt, abort is now safe
+ ARM( msr cpsr_c, #SVC_MODE | PSR_I_BIT | PSR_F_BIT )
+ THUMB( mov r0, #SVC_MODE | PSR_I_BIT | PSR_F_BIT )
+ THUMB( msr cpsr_c, r0 )
+ stmfd sp!, {r1 - r2}
+
+ add r0, sp, #8 @ struct pt_regs *regs
+ bl handle_fiq_as_nmi
+
+ ldmfd sp!, {r1 - r2}
+ ARM( msr cpsr_c, #ABT_MODE | PSR_I_BIT | PSR_F_BIT )
+ THUMB( mov r0, #ABT_MODE | PSR_I_BIT | PSR_F_BIT )
+ THUMB( msr cpsr_c, r0 )
+ mov lr, r1 @ Restore lr_abt, abort is unsafe
+ msr spsr_cxsf, r2 @ Restore spsr_abt
+ ARM( msr cpsr_c, #SVC_MODE | PSR_I_BIT | PSR_F_BIT )
+ THUMB( mov r0, #SVC_MODE | PSR_I_BIT | PSR_F_BIT )
+ THUMB( msr cpsr_c, r0 )
+
+ svc_exit_via_fiq
+ UNWIND(.fnend )
+ENDPROC(__fiq_abt)
+
+/*
+ * User mode handlers
+ *
+ * EABI note: sp_svc is always 64-bit aligned here, so should S_FRAME_SIZE
+ */
+
+#if defined(CONFIG_AEABI) && (__LINUX_ARM_ARCH__ >= 5) && (S_FRAME_SIZE & 7)
+#error "sizeof(struct pt_regs) must be a multiple of 8"
+#endif
+
+ .macro usr_entry, trace=1
+ UNWIND(.fnstart )
+ UNWIND(.cantunwind ) @ don't unwind the user space
+ sub sp, sp, #S_FRAME_SIZE
+ ARM( stmib sp, {r1 - r12} )
+ THUMB( stmia sp, {r0 - r12} )
+
+ ATRAP( mrc p15, 0, r7, c1, c0, 0)
+ ATRAP( ldr r8, .LCcralign)
+
+ ldmia r0, {r3 - r5}
+ add r0, sp, #S_PC @ here for interlock avoidance
+ mov r6, #-1 @ "" "" "" ""
+
+ str r3, [sp] @ save the "real" r0 copied
+ @ from the exception stack
+
+ ATRAP( ldr r8, [r8, #0])
+
+ @
+ @ We are now ready to fill in the remaining blanks on the stack:
+ @
+ @ r4 - lr_<exception>, already fixed up for correct return/restart
+ @ r5 - spsr_<exception>
+ @ r6 - orig_r0 (see pt_regs definition in ptrace.h)
+ @
+ @ Also, separately save sp_usr and lr_usr
+ @
+ stmia r0, {r4 - r6}
+ ARM( stmdb r0, {sp, lr}^ )
+ THUMB( store_user_sp_lr r0, r1, S_SP - S_PC )
+
+ @ Enable the alignment trap while in kernel mode
+ ATRAP( teq r8, r7)
+ ATRAP( mcrne p15, 0, r8, c1, c0, 0)
+
+ @
+ @ Clear FP to mark the first stack frame
+ @
+ zero_fp
+
+ .if \trace
+#ifdef CONFIG_IRQSOFF_TRACER
+ bl trace_hardirqs_off
+#endif
+ ct_user_exit save = 0
+ .endif
+ .endm
+
+ .macro kuser_cmpxchg_check
+#if !defined(CONFIG_CPU_32v6K) && defined(CONFIG_KUSER_HELPERS) && \
+ !defined(CONFIG_NEEDS_SYSCALL_FOR_CMPXCHG)
+#ifndef CONFIG_MMU
+#warning "NPTL on non MMU needs fixing"
+#else
+ @ Make sure our user space atomic helper is restarted
+ @ if it was interrupted in a critical region. Here we
+ @ perform a quick test inline since it should be false
+ @ 99.9999% of the time. The rest is done out of line.
+ cmp r4, #TASK_SIZE
+ blhs kuser_cmpxchg64_fixup
+#endif
+#endif
+ .endm
+
+ .align 5
+__dabt_usr:
+ usr_entry
+ kuser_cmpxchg_check
+ mov r2, sp
+ dabt_helper
+ b ret_from_exception
+ UNWIND(.fnend )
+ENDPROC(__dabt_usr)
+
+ .align 5
+__irq_usr:
+ usr_entry
+ kuser_cmpxchg_check
+ irq_handler
+ get_thread_info tsk
+ mov why, #0
+ b ret_to_user_from_irq
+ UNWIND(.fnend )
+ENDPROC(__irq_usr)
+
+ .ltorg
+
+ .align 5
+__und_usr:
+ usr_entry
+
+ mov r2, r4
+ mov r3, r5
+
+ @ r2 = regs->ARM_pc, which is either 2 or 4 bytes ahead of the
+ @ faulting instruction depending on Thumb mode.
+ @ r3 = regs->ARM_cpsr
+ @
+ @ The emulation code returns using r9 if it has emulated the
+ @ instruction, or the more conventional lr if we are to treat
+ @ this as a real undefined instruction
+ @
+ adr r9, BSYM(ret_from_exception)
+
+ @ IRQs must be enabled before attempting to read the instruction from
+ @ user space since that could cause a page/translation fault if the
+ @ page table was modified by another CPU.
+ enable_irq
+
+ tst r3, #PSR_T_BIT @ Thumb mode?
+ bne __und_usr_thumb
+ sub r4, r2, #4 @ ARM instr at LR - 4
+1: ldrt r0, [r4]
+ ARM_BE8(rev r0, r0) @ little endian instruction
+
+ @ r0 = 32-bit ARM instruction which caused the exception
+ @ r2 = PC value for the following instruction (:= regs->ARM_pc)
+ @ r4 = PC value for the faulting instruction
+ @ lr = 32-bit undefined instruction function
+ adr lr, BSYM(__und_usr_fault_32)
+ b call_fpe
+
+__und_usr_thumb:
+ @ Thumb instruction
+ sub r4, r2, #2 @ First half of thumb instr at LR - 2
+#if CONFIG_ARM_THUMB && __LINUX_ARM_ARCH__ >= 6 && CONFIG_CPU_V7
+/*
+ * Thumb-2 instruction handling. Note that because pre-v6 and >= v6 platforms
+ * can never be supported in a single kernel, this code is not applicable at
+ * all when __LINUX_ARM_ARCH__ < 6. This allows simplifying assumptions to be
+ * made about .arch directives.
+ */
+#if __LINUX_ARM_ARCH__ < 7
+/* If the target CPU may not be Thumb-2-capable, a run-time check is needed: */
+#define NEED_CPU_ARCHITECTURE
+ ldr r5, .LCcpu_architecture
+ ldr r5, [r5]
+ cmp r5, #CPU_ARCH_ARMv7
+ blo __und_usr_fault_16 @ 16bit undefined instruction
+/*
+ * The following code won't get run unless the running CPU really is v7, so
+ * coding round the lack of ldrht on older arches is pointless. Temporarily
+ * override the assembler target arch with the minimum required instead:
+ */
+ .arch armv6t2
+#endif
+2: ldrht r5, [r4]
+ARM_BE8(rev16 r5, r5) @ little endian instruction
+ cmp r5, #0xe800 @ 32bit instruction if xx != 0
+ blo __und_usr_fault_16 @ 16bit undefined instruction
+3: ldrht r0, [r2]
+ARM_BE8(rev16 r0, r0) @ little endian instruction
+ add r2, r2, #2 @ r2 is PC + 2, make it PC + 4
+ str r2, [sp, #S_PC] @ it's a 2x16bit instr, update
+ orr r0, r0, r5, lsl #16
+ adr lr, BSYM(__und_usr_fault_32)
+ @ r0 = the two 16-bit Thumb instructions which caused the exception
+ @ r2 = PC value for the following Thumb instruction (:= regs->ARM_pc)
+ @ r4 = PC value for the first 16-bit Thumb instruction
+ @ lr = 32bit undefined instruction function
+
+#if __LINUX_ARM_ARCH__ < 7
+/* If the target arch was overridden, change it back: */
+#ifdef CONFIG_CPU_32v6K
+ .arch armv6k
+#else
+ .arch armv6
+#endif
+#endif /* __LINUX_ARM_ARCH__ < 7 */
+#else /* !(CONFIG_ARM_THUMB && __LINUX_ARM_ARCH__ >= 6 && CONFIG_CPU_V7) */
+ b __und_usr_fault_16
+#endif
+ UNWIND(.fnend)
+ENDPROC(__und_usr)
+
+/*
+ * The out of line fixup for the ldrt instructions above.
+ */
+ .pushsection .text.fixup, "ax"
+ .align 2
+4: str r4, [sp, #S_PC] @ retry current instruction
+ ret r9
+ .popsection
+ .pushsection __ex_table,"a"
+ .long 1b, 4b
+#if CONFIG_ARM_THUMB && __LINUX_ARM_ARCH__ >= 6 && CONFIG_CPU_V7
+ .long 2b, 4b
+ .long 3b, 4b
+#endif
+ .popsection
+
+/*
+ * Check whether the instruction is a co-processor instruction.
+ * If yes, we need to call the relevant co-processor handler.
+ *
+ * Note that we don't do a full check here for the co-processor
+ * instructions; all instructions with bit 27 set are well
+ * defined. The only instructions that should fault are the
+ * co-processor instructions. However, we have to watch out
+ * for the ARM6/ARM7 SWI bug.
+ *
+ * NEON is a special case that has to be handled here. Not all
+ * NEON instructions are co-processor instructions, so we have
+ * to make a special case of checking for them. Plus, there's
+ * five groups of them, so we have a table of mask/opcode pairs
+ * to check against, and if any match then we branch off into the
+ * NEON handler code.
+ *
+ * Emulators may wish to make use of the following registers:
+ * r0 = instruction opcode (32-bit ARM or two 16-bit Thumb)
+ * r2 = PC value to resume execution after successful emulation
+ * r9 = normal "successful" return address
+ * r10 = this threads thread_info structure
+ * lr = unrecognised instruction return address
+ * IRQs enabled, FIQs enabled.
+ */
+ @
+ @ Fall-through from Thumb-2 __und_usr
+ @
+#ifdef CONFIG_NEON
+ get_thread_info r10 @ get current thread
+ adr r6, .LCneon_thumb_opcodes
+ b 2f
+#endif
+call_fpe:
+ get_thread_info r10 @ get current thread
+#ifdef CONFIG_NEON
+ adr r6, .LCneon_arm_opcodes
+2: ldr r5, [r6], #4 @ mask value
+ ldr r7, [r6], #4 @ opcode bits matching in mask
+ cmp r5, #0 @ end mask?
+ beq 1f
+ and r8, r0, r5
+ cmp r8, r7 @ NEON instruction?
+ bne 2b
+ mov r7, #1
+ strb r7, [r10, #TI_USED_CP + 10] @ mark CP#10 as used
+ strb r7, [r10, #TI_USED_CP + 11] @ mark CP#11 as used
+ b do_vfp @ let VFP handler handle this
+1:
+#endif
+ tst r0, #0x08000000 @ only CDP/CPRT/LDC/STC have bit 27
+ tstne r0, #0x04000000 @ bit 26 set on both ARM and Thumb-2
+ reteq lr
+ and r8, r0, #0x00000f00 @ mask out CP number
+ THUMB( lsr r8, r8, #8 )
+ mov r7, #1
+ add r6, r10, #TI_USED_CP
+ ARM( strb r7, [r6, r8, lsr #8] ) @ set appropriate used_cp[]
+ THUMB( strb r7, [r6, r8] ) @ set appropriate used_cp[]
+#ifdef CONFIG_IWMMXT
+ @ Test if we need to give access to iWMMXt coprocessors
+ ldr r5, [r10, #TI_FLAGS]
+ rsbs r7, r8, #(1 << 8) @ CP 0 or 1 only
+ movcss r7, r5, lsr #(TIF_USING_IWMMXT + 1)
+ bcs iwmmxt_task_enable
+#endif
+ ARM( add pc, pc, r8, lsr #6 )
+ THUMB( lsl r8, r8, #2 )
+ THUMB( add pc, r8 )
+ nop
+
+ ret.w lr @ CP#0
+ W(b) do_fpe @ CP#1 (FPE)
+ W(b) do_fpe @ CP#2 (FPE)
+ ret.w lr @ CP#3
+#ifdef CONFIG_CRUNCH
+ b crunch_task_enable @ CP#4 (MaverickCrunch)
+ b crunch_task_enable @ CP#5 (MaverickCrunch)
+ b crunch_task_enable @ CP#6 (MaverickCrunch)
+#else
+ ret.w lr @ CP#4
+ ret.w lr @ CP#5
+ ret.w lr @ CP#6
+#endif
+ ret.w lr @ CP#7
+ ret.w lr @ CP#8
+ ret.w lr @ CP#9
+#ifdef CONFIG_VFP
+ W(b) do_vfp @ CP#10 (VFP)
+ W(b) do_vfp @ CP#11 (VFP)
+#else
+ ret.w lr @ CP#10 (VFP)
+ ret.w lr @ CP#11 (VFP)
+#endif
+ ret.w lr @ CP#12
+ ret.w lr @ CP#13
+ ret.w lr @ CP#14 (Debug)
+ ret.w lr @ CP#15 (Control)
+
+#ifdef NEED_CPU_ARCHITECTURE
+ .align 2
+.LCcpu_architecture:
+ .word __cpu_architecture
+#endif
+
+#ifdef CONFIG_NEON
+ .align 6
+
+.LCneon_arm_opcodes:
+ .word 0xfe000000 @ mask
+ .word 0xf2000000 @ opcode
+
+ .word 0xff100000 @ mask
+ .word 0xf4000000 @ opcode
+
+ .word 0x00000000 @ mask
+ .word 0x00000000 @ opcode
+
+.LCneon_thumb_opcodes:
+ .word 0xef000000 @ mask
+ .word 0xef000000 @ opcode
+
+ .word 0xff100000 @ mask
+ .word 0xf9000000 @ opcode
+
+ .word 0x00000000 @ mask
+ .word 0x00000000 @ opcode
+#endif
+
+do_fpe:
+ ldr r4, .LCfp
+ add r10, r10, #TI_FPSTATE @ r10 = workspace
+ ldr pc, [r4] @ Call FP module USR entry point
+
+/*
+ * The FP module is called with these registers set:
+ * r0 = instruction
+ * r2 = PC+4
+ * r9 = normal "successful" return address
+ * r10 = FP workspace
+ * lr = unrecognised FP instruction return address
+ */
+
+ .pushsection .data
+ENTRY(fp_enter)
+ .word no_fp
+ .popsection
+
+ENTRY(no_fp)
+ ret lr
+ENDPROC(no_fp)
+
+__und_usr_fault_32:
+ mov r1, #4
+ b 1f
+__und_usr_fault_16:
+ mov r1, #2
+1: mov r0, sp
+ adr lr, BSYM(ret_from_exception)
+ b __und_fault
+ENDPROC(__und_usr_fault_32)
+ENDPROC(__und_usr_fault_16)
+
+ .align 5
+__pabt_usr:
+ usr_entry
+ mov r2, sp @ regs
+ pabt_helper
+ UNWIND(.fnend )
+ /* fall through */
+/*
+ * This is the return code to user mode for abort handlers
+ */
+ENTRY(ret_from_exception)
+ UNWIND(.fnstart )
+ UNWIND(.cantunwind )
+ get_thread_info tsk
+ mov why, #0
+ b ret_to_user
+ UNWIND(.fnend )
+ENDPROC(__pabt_usr)
+ENDPROC(ret_from_exception)
+
+ .align 5
+__fiq_usr:
+ usr_entry trace=0
+ kuser_cmpxchg_check
+ mov r0, sp @ struct pt_regs *regs
+ bl handle_fiq_as_nmi
+ get_thread_info tsk
+ restore_user_regs fast = 0, offset = 0
+ UNWIND(.fnend )
+ENDPROC(__fiq_usr)
+
+/*
+ * Register switch for ARMv3 and ARMv4 processors
+ * r0 = previous task_struct, r1 = previous thread_info, r2 = next thread_info
+ * previous and next are guaranteed not to be the same.
+ */
+ENTRY(__switch_to)
+ UNWIND(.fnstart )
+ UNWIND(.cantunwind )
+ add ip, r1, #TI_CPU_SAVE
+ ARM( stmia ip!, {r4 - sl, fp, sp, lr} ) @ Store most regs on stack
+ THUMB( stmia ip!, {r4 - sl, fp} ) @ Store most regs on stack
+ THUMB( str sp, [ip], #4 )
+ THUMB( str lr, [ip], #4 )
+ ldr r4, [r2, #TI_TP_VALUE]
+ ldr r5, [r2, #TI_TP_VALUE + 4]
+#ifdef CONFIG_CPU_USE_DOMAINS
+ ldr r6, [r2, #TI_CPU_DOMAIN]
+#endif
+ switch_tls r1, r4, r5, r3, r7
+#if defined(CONFIG_CC_STACKPROTECTOR) && !defined(CONFIG_SMP)
+ ldr r7, [r2, #TI_TASK]
+ ldr r8, =__stack_chk_guard
+ ldr r7, [r7, #TSK_STACK_CANARY]
+#endif
+#ifdef CONFIG_CPU_USE_DOMAINS
+ mcr p15, 0, r6, c3, c0, 0 @ Set domain register
+#endif
+ mov r5, r0
+ add r4, r2, #TI_CPU_SAVE
+ ldr r0, =thread_notify_head
+ mov r1, #THREAD_NOTIFY_SWITCH
+ bl atomic_notifier_call_chain
+#if defined(CONFIG_CC_STACKPROTECTOR) && !defined(CONFIG_SMP)
+ str r7, [r8]
+#endif
+ THUMB( mov ip, r4 )
+ mov r0, r5
+ ARM( ldmia r4, {r4 - sl, fp, sp, pc} ) @ Load all regs saved previously
+ THUMB( ldmia ip!, {r4 - sl, fp} ) @ Load all regs saved previously
+ THUMB( ldr sp, [ip], #4 )
+ THUMB( ldr pc, [ip] )
+ UNWIND(.fnend )
+ENDPROC(__switch_to)
+
+ __INIT
+
+/*
+ * User helpers.
+ *
+ * Each segment is 32-byte aligned and will be moved to the top of the high
+ * vector page. New segments (if ever needed) must be added in front of
+ * existing ones. This mechanism should be used only for things that are
+ * really small and justified, and not be abused freely.
+ *
+ * See Documentation/arm/kernel_user_helpers.txt for formal definitions.
+ */
+ THUMB( .arm )
+
+ .macro usr_ret, reg
+#ifdef CONFIG_ARM_THUMB
+ bx \reg
+#else
+ ret \reg
+#endif
+ .endm
+
+ .macro kuser_pad, sym, size
+ .if (. - \sym) & 3
+ .rept 4 - (. - \sym) & 3
+ .byte 0
+ .endr
+ .endif
+ .rept (\size - (. - \sym)) / 4
+ .word 0xe7fddef1
+ .endr
+ .endm
+
+#ifdef CONFIG_KUSER_HELPERS
+ .align 5
+ .globl __kuser_helper_start
+__kuser_helper_start:
+
+/*
+ * Due to the length of some sequences, __kuser_cmpxchg64 spans 2 regular
+ * kuser "slots", therefore 0xffff0f80 is not used as a valid entry point.
+ */
+
+__kuser_cmpxchg64: @ 0xffff0f60
+
+#if defined(CONFIG_NEEDS_SYSCALL_FOR_CMPXCHG)
+
+ /*
+ * Poor you. No fast solution possible...
+ * The kernel itself must perform the operation.
+ * A special ghost syscall is used for that (see traps.c).
+ */
+ stmfd sp!, {r7, lr}
+ ldr r7, 1f @ it's 20 bits
+ swi __ARM_NR_cmpxchg64
+ ldmfd sp!, {r7, pc}
+1: .word __ARM_NR_cmpxchg64
+
+#elif defined(CONFIG_CPU_32v6K)
+
+ stmfd sp!, {r4, r5, r6, r7}
+ ldrd r4, r5, [r0] @ load old val
+ ldrd r6, r7, [r1] @ load new val
+ smp_dmb arm
+1: ldrexd r0, r1, [r2] @ load current val
+ eors r3, r0, r4 @ compare with oldval (1)
+ eoreqs r3, r1, r5 @ compare with oldval (2)
+ strexdeq r3, r6, r7, [r2] @ store newval if eq
+ teqeq r3, #1 @ success?
+ beq 1b @ if no then retry
+ smp_dmb arm
+ rsbs r0, r3, #0 @ set returned val and C flag
+ ldmfd sp!, {r4, r5, r6, r7}
+ usr_ret lr
+
+#elif !defined(CONFIG_SMP)
+
+#ifdef CONFIG_MMU
+
+ /*
+ * The only thing that can break atomicity in this cmpxchg64
+ * implementation is either an IRQ or a data abort exception
+ * causing another process/thread to be scheduled in the middle of
+ * the critical sequence. The same strategy as for cmpxchg is used.
+ */
+ stmfd sp!, {r4, r5, r6, lr}
+ ldmia r0, {r4, r5} @ load old val
+ ldmia r1, {r6, lr} @ load new val
+1: ldmia r2, {r0, r1} @ load current val
+ eors r3, r0, r4 @ compare with oldval (1)
+ eoreqs r3, r1, r5 @ compare with oldval (2)
+2: stmeqia r2, {r6, lr} @ store newval if eq
+ rsbs r0, r3, #0 @ set return val and C flag
+ ldmfd sp!, {r4, r5, r6, pc}
+
+ .text
+kuser_cmpxchg64_fixup:
+ @ Called from kuser_cmpxchg_fixup.
+ @ r4 = address of interrupted insn (must be preserved).
+ @ sp = saved regs. r7 and r8 are clobbered.
+ @ 1b = first critical insn, 2b = last critical insn.
+ @ If r4 >= 1b and r4 <= 2b then saved pc_usr is set to 1b.
+ mov r7, #0xffff0fff
+ sub r7, r7, #(0xffff0fff - (0xffff0f60 + (1b - __kuser_cmpxchg64)))
+ subs r8, r4, r7
+ rsbcss r8, r8, #(2b - 1b)
+ strcs r7, [sp, #S_PC]
+#if __LINUX_ARM_ARCH__ < 6
+ bcc kuser_cmpxchg32_fixup
+#endif
+ ret lr
+ .previous
+
+#else
+#warning "NPTL on non MMU needs fixing"
+ mov r0, #-1
+ adds r0, r0, #0
+ usr_ret lr
+#endif
+
+#else
+#error "incoherent kernel configuration"
+#endif
+
+ kuser_pad __kuser_cmpxchg64, 64
+
+__kuser_memory_barrier: @ 0xffff0fa0
+ smp_dmb arm
+ usr_ret lr
+
+ kuser_pad __kuser_memory_barrier, 32
+
+__kuser_cmpxchg: @ 0xffff0fc0
+
+#if defined(CONFIG_NEEDS_SYSCALL_FOR_CMPXCHG)
+
+ /*
+ * Poor you. No fast solution possible...
+ * The kernel itself must perform the operation.
+ * A special ghost syscall is used for that (see traps.c).
+ */
+ stmfd sp!, {r7, lr}
+ ldr r7, 1f @ it's 20 bits
+ swi __ARM_NR_cmpxchg
+ ldmfd sp!, {r7, pc}
+1: .word __ARM_NR_cmpxchg
+
+#elif __LINUX_ARM_ARCH__ < 6
+
+#ifdef CONFIG_MMU
+
+ /*
+ * The only thing that can break atomicity in this cmpxchg
+ * implementation is either an IRQ or a data abort exception
+ * causing another process/thread to be scheduled in the middle
+ * of the critical sequence. To prevent this, code is added to
+ * the IRQ and data abort exception handlers to set the pc back
+ * to the beginning of the critical section if it is found to be
+ * within that critical section (see kuser_cmpxchg_fixup).
+ */
+1: ldr r3, [r2] @ load current val
+ subs r3, r3, r0 @ compare with oldval
+2: streq r1, [r2] @ store newval if eq
+ rsbs r0, r3, #0 @ set return val and C flag
+ usr_ret lr
+
+ .text
+kuser_cmpxchg32_fixup:
+ @ Called from kuser_cmpxchg_check macro.
+ @ r4 = address of interrupted insn (must be preserved).
+ @ sp = saved regs. r7 and r8 are clobbered.
+ @ 1b = first critical insn, 2b = last critical insn.
+ @ If r4 >= 1b and r4 <= 2b then saved pc_usr is set to 1b.
+ mov r7, #0xffff0fff
+ sub r7, r7, #(0xffff0fff - (0xffff0fc0 + (1b - __kuser_cmpxchg)))
+ subs r8, r4, r7
+ rsbcss r8, r8, #(2b - 1b)
+ strcs r7, [sp, #S_PC]
+ ret lr
+ .previous
+
+#else
+#warning "NPTL on non MMU needs fixing"
+ mov r0, #-1
+ adds r0, r0, #0
+ usr_ret lr
+#endif
+
+#else
+
+ smp_dmb arm
+1: ldrex r3, [r2]
+ subs r3, r3, r0
+ strexeq r3, r1, [r2]
+ teqeq r3, #1
+ beq 1b
+ rsbs r0, r3, #0
+ /* beware -- each __kuser slot must be 8 instructions max */
+ ALT_SMP(b __kuser_memory_barrier)
+ ALT_UP(usr_ret lr)
+
+#endif
+
+ kuser_pad __kuser_cmpxchg, 32
+
+__kuser_get_tls: @ 0xffff0fe0
+ ldr r0, [pc, #(16 - 8)] @ read TLS, set in kuser_get_tls_init
+ usr_ret lr
+ mrc p15, 0, r0, c13, c0, 3 @ 0xffff0fe8 hardware TLS code
+ kuser_pad __kuser_get_tls, 16
+ .rep 3
+ .word 0 @ 0xffff0ff0 software TLS value, then
+ .endr @ pad up to __kuser_helper_version
+
+__kuser_helper_version: @ 0xffff0ffc
+ .word ((__kuser_helper_end - __kuser_helper_start) >> 5)
+
+ .globl __kuser_helper_end
+__kuser_helper_end:
+
+#endif
+
+ THUMB( .thumb )
+
+/*
+ * Vector stubs.
+ *
+ * This code is copied to 0xffff1000 so we can use branches in the
+ * vectors, rather than ldr's. Note that this code must not exceed
+ * a page size.
+ *
+ * Common stub entry macro:
+ * Enter in IRQ mode, spsr = SVC/USR CPSR, lr = SVC/USR PC
+ *
+ * SP points to a minimal amount of processor-private memory, the address
+ * of which is copied into r0 for the mode specific abort handler.
+ */
+ .macro vector_stub, name, mode, correction=0
+ .align 5
+
+vector_\name:
+ .if \correction
+ sub lr, lr, #\correction
+ .endif
+
+ @
+ @ Save r0, lr_<exception> (parent PC) and spsr_<exception>
+ @ (parent CPSR)
+ @
+ stmia sp, {r0, lr} @ save r0, lr
+ mrs lr, spsr
+ str lr, [sp, #8] @ save spsr
+
+ @
+ @ Prepare for SVC32 mode. IRQs remain disabled.
+ @
+ mrs r0, cpsr
+ eor r0, r0, #(\mode ^ SVC_MODE | PSR_ISETSTATE)
+ msr spsr_cxsf, r0
+
+ @
+ @ the branch table must immediately follow this code
+ @
+ and lr, lr, #0x0f
+ THUMB( adr r0, 1f )
+ THUMB( ldr lr, [r0, lr, lsl #2] )
+ mov r0, sp
+ ARM( ldr lr, [pc, lr, lsl #2] )
+ movs pc, lr @ branch to handler in SVC mode
+ENDPROC(vector_\name)
+
+ .align 2
+ @ handler addresses follow this label
+1:
+ .endm
+
+ .section .stubs, "ax", %progbits
+__stubs_start:
+ @ This must be the first word
+ .word vector_swi
+
+vector_rst:
+ ARM( swi SYS_ERROR0 )
+ THUMB( svc #0 )
+ THUMB( nop )
+ b vector_und
+
+/*
+ * Interrupt dispatcher
+ */
+ vector_stub irq, IRQ_MODE, 4
+
+ .long __irq_usr @ 0 (USR_26 / USR_32)
+ .long __irq_invalid @ 1 (FIQ_26 / FIQ_32)
+ .long __irq_invalid @ 2 (IRQ_26 / IRQ_32)
+ .long __irq_svc @ 3 (SVC_26 / SVC_32)
+ .long __irq_invalid @ 4
+ .long __irq_invalid @ 5
+ .long __irq_invalid @ 6
+ .long __irq_invalid @ 7
+ .long __irq_invalid @ 8
+ .long __irq_invalid @ 9
+ .long __irq_invalid @ a
+ .long __irq_invalid @ b
+ .long __irq_invalid @ c
+ .long __irq_invalid @ d
+ .long __irq_invalid @ e
+ .long __irq_invalid @ f
+
+/*
+ * Data abort dispatcher
+ * Enter in ABT mode, spsr = USR CPSR, lr = USR PC
+ */
+ vector_stub dabt, ABT_MODE, 8
+
+ .long __dabt_usr @ 0 (USR_26 / USR_32)
+ .long __dabt_invalid @ 1 (FIQ_26 / FIQ_32)
+ .long __dabt_invalid @ 2 (IRQ_26 / IRQ_32)
+ .long __dabt_svc @ 3 (SVC_26 / SVC_32)
+ .long __dabt_invalid @ 4
+ .long __dabt_invalid @ 5
+ .long __dabt_invalid @ 6
+ .long __dabt_invalid @ 7
+ .long __dabt_invalid @ 8
+ .long __dabt_invalid @ 9
+ .long __dabt_invalid @ a
+ .long __dabt_invalid @ b
+ .long __dabt_invalid @ c
+ .long __dabt_invalid @ d
+ .long __dabt_invalid @ e
+ .long __dabt_invalid @ f
+
+/*
+ * Prefetch abort dispatcher
+ * Enter in ABT mode, spsr = USR CPSR, lr = USR PC
+ */
+ vector_stub pabt, ABT_MODE, 4
+
+ .long __pabt_usr @ 0 (USR_26 / USR_32)
+ .long __pabt_invalid @ 1 (FIQ_26 / FIQ_32)
+ .long __pabt_invalid @ 2 (IRQ_26 / IRQ_32)
+ .long __pabt_svc @ 3 (SVC_26 / SVC_32)
+ .long __pabt_invalid @ 4
+ .long __pabt_invalid @ 5
+ .long __pabt_invalid @ 6
+ .long __pabt_invalid @ 7
+ .long __pabt_invalid @ 8
+ .long __pabt_invalid @ 9
+ .long __pabt_invalid @ a
+ .long __pabt_invalid @ b
+ .long __pabt_invalid @ c
+ .long __pabt_invalid @ d
+ .long __pabt_invalid @ e
+ .long __pabt_invalid @ f
+
+/*
+ * Undef instr entry dispatcher
+ * Enter in UND mode, spsr = SVC/USR CPSR, lr = SVC/USR PC
+ */
+ vector_stub und, UND_MODE
+
+ .long __und_usr @ 0 (USR_26 / USR_32)
+ .long __und_invalid @ 1 (FIQ_26 / FIQ_32)
+ .long __und_invalid @ 2 (IRQ_26 / IRQ_32)
+ .long __und_svc @ 3 (SVC_26 / SVC_32)
+ .long __und_invalid @ 4
+ .long __und_invalid @ 5
+ .long __und_invalid @ 6
+ .long __und_invalid @ 7
+ .long __und_invalid @ 8
+ .long __und_invalid @ 9
+ .long __und_invalid @ a
+ .long __und_invalid @ b
+ .long __und_invalid @ c
+ .long __und_invalid @ d
+ .long __und_invalid @ e
+ .long __und_invalid @ f
+
+ .align 5
+
+/*=============================================================================
+ * Address exception handler
+ *-----------------------------------------------------------------------------
+ * These aren't too critical.
+ * (they're not supposed to happen, and won't happen in 32-bit data mode).
+ */
+
+vector_addrexcptn:
+ b vector_addrexcptn
+
+/*=============================================================================
+ * FIQ "NMI" handler
+ *-----------------------------------------------------------------------------
+ * Handle a FIQ using the SVC stack allowing FIQ act like NMI on x86
+ * systems.
+ */
+ vector_stub fiq, FIQ_MODE, 4
+
+ .long __fiq_usr @ 0 (USR_26 / USR_32)
+ .long __fiq_svc @ 1 (FIQ_26 / FIQ_32)
+ .long __fiq_svc @ 2 (IRQ_26 / IRQ_32)
+ .long __fiq_svc @ 3 (SVC_26 / SVC_32)
+ .long __fiq_svc @ 4
+ .long __fiq_svc @ 5
+ .long __fiq_svc @ 6
+ .long __fiq_abt @ 7
+ .long __fiq_svc @ 8
+ .long __fiq_svc @ 9
+ .long __fiq_svc @ a
+ .long __fiq_svc @ b
+ .long __fiq_svc @ c
+ .long __fiq_svc @ d
+ .long __fiq_svc @ e
+ .long __fiq_svc @ f
+
+ .globl vector_fiq_offset
+ .equ vector_fiq_offset, vector_fiq
+
+ .section .vectors, "ax", %progbits
+__vectors_start:
+ W(b) vector_rst
+ W(b) vector_und
+ W(ldr) pc, __vectors_start + 0x1000
+ W(b) vector_pabt
+ W(b) vector_dabt
+ W(b) vector_addrexcptn
+ W(b) vector_irq
+ W(b) vector_fiq
+
+ .data
+
+ .globl cr_alignment
+cr_alignment:
+ .space 4
+
+#ifdef CONFIG_MULTI_IRQ_HANDLER
+ .globl handle_arch_irq
+handle_arch_irq:
+ .space 4
+#endif