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Diffstat (limited to 'arch/parisc/kernel/entry.S')
| -rw-r--r-- | arch/parisc/kernel/entry.S | 2198 |
1 files changed, 2198 insertions, 0 deletions
diff --git a/arch/parisc/kernel/entry.S b/arch/parisc/kernel/entry.S new file mode 100644 index 000000000..75819617f --- /dev/null +++ b/arch/parisc/kernel/entry.S @@ -0,0 +1,2198 @@ +/* + * Linux/PA-RISC Project (http://www.parisc-linux.org/) + * + * kernel entry points (interruptions, system call wrappers) + * Copyright (C) 1999,2000 Philipp Rumpf + * Copyright (C) 1999 SuSE GmbH Nuernberg + * Copyright (C) 2000 Hewlett-Packard (John Marvin) + * Copyright (C) 1999 Hewlett-Packard (Frank Rowand) + * + * 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, or (at your option) + * any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. + */ + +#include <asm/asm-offsets.h> + +/* we have the following possibilities to act on an interruption: + * - handle in assembly and use shadowed registers only + * - save registers to kernel stack and handle in assembly or C */ + + +#include <asm/psw.h> +#include <asm/cache.h> /* for L1_CACHE_SHIFT */ +#include <asm/assembly.h> /* for LDREG/STREG defines */ +#include <asm/pgtable.h> +#include <asm/signal.h> +#include <asm/unistd.h> +#include <asm/thread_info.h> + +#include <linux/linkage.h> + +#ifdef CONFIG_64BIT + .level 2.0w +#else + .level 2.0 +#endif + + .import pa_dbit_lock,data + + /* space_to_prot macro creates a prot id from a space id */ + +#if (SPACEID_SHIFT) == 0 + .macro space_to_prot spc prot + depd,z \spc,62,31,\prot + .endm +#else + .macro space_to_prot spc prot + extrd,u \spc,(64 - (SPACEID_SHIFT)),32,\prot + .endm +#endif + + /* Switch to virtual mapping, trashing only %r1 */ + .macro virt_map + /* pcxt_ssm_bug */ + rsm PSW_SM_I, %r0 /* barrier for "Relied upon Translation */ + mtsp %r0, %sr4 + mtsp %r0, %sr5 + mtsp %r0, %sr6 + tovirt_r1 %r29 + load32 KERNEL_PSW, %r1 + + rsm PSW_SM_QUIET,%r0 /* second "heavy weight" ctl op */ + mtctl %r0, %cr17 /* Clear IIASQ tail */ + mtctl %r0, %cr17 /* Clear IIASQ head */ + mtctl %r1, %ipsw + load32 4f, %r1 + mtctl %r1, %cr18 /* Set IIAOQ tail */ + ldo 4(%r1), %r1 + mtctl %r1, %cr18 /* Set IIAOQ head */ + rfir + nop +4: + .endm + + /* + * The "get_stack" macros are responsible for determining the + * kernel stack value. + * + * If sr7 == 0 + * Already using a kernel stack, so call the + * get_stack_use_r30 macro to push a pt_regs structure + * on the stack, and store registers there. + * else + * Need to set up a kernel stack, so call the + * get_stack_use_cr30 macro to set up a pointer + * to the pt_regs structure contained within the + * task pointer pointed to by cr30. Set the stack + * pointer to point to the end of the task structure. + * + * Note that we use shadowed registers for temps until + * we can save %r26 and %r29. %r26 is used to preserve + * %r8 (a shadowed register) which temporarily contained + * either the fault type ("code") or the eirr. We need + * to use a non-shadowed register to carry the value over + * the rfir in virt_map. We use %r26 since this value winds + * up being passed as the argument to either do_cpu_irq_mask + * or handle_interruption. %r29 is used to hold a pointer + * the register save area, and once again, it needs to + * be a non-shadowed register so that it survives the rfir. + * + * N.B. TASK_SZ_ALGN and PT_SZ_ALGN include space for a stack frame. + */ + + .macro get_stack_use_cr30 + + /* we save the registers in the task struct */ + + copy %r30, %r17 + mfctl %cr30, %r1 + ldo THREAD_SZ_ALGN(%r1), %r30 + mtsp %r0,%sr7 + mtsp %r16,%sr3 + tophys %r1,%r9 + LDREG TI_TASK(%r9), %r1 /* thread_info -> task_struct */ + tophys %r1,%r9 + ldo TASK_REGS(%r9),%r9 + STREG %r17,PT_GR30(%r9) + STREG %r29,PT_GR29(%r9) + STREG %r26,PT_GR26(%r9) + STREG %r16,PT_SR7(%r9) + copy %r9,%r29 + .endm + + .macro get_stack_use_r30 + + /* we put a struct pt_regs on the stack and save the registers there */ + + tophys %r30,%r9 + copy %r30,%r1 + ldo PT_SZ_ALGN(%r30),%r30 + STREG %r1,PT_GR30(%r9) + STREG %r29,PT_GR29(%r9) + STREG %r26,PT_GR26(%r9) + STREG %r16,PT_SR7(%r9) + copy %r9,%r29 + .endm + + .macro rest_stack + LDREG PT_GR1(%r29), %r1 + LDREG PT_GR30(%r29),%r30 + LDREG PT_GR29(%r29),%r29 + .endm + + /* default interruption handler + * (calls traps.c:handle_interruption) */ + .macro def code + b intr_save + ldi \code, %r8 + .align 32 + .endm + + /* Interrupt interruption handler + * (calls irq.c:do_cpu_irq_mask) */ + .macro extint code + b intr_extint + mfsp %sr7,%r16 + .align 32 + .endm + + .import os_hpmc, code + + /* HPMC handler */ + .macro hpmc code + nop /* must be a NOP, will be patched later */ + load32 PA(os_hpmc), %r3 + bv,n 0(%r3) + nop + .word 0 /* checksum (will be patched) */ + .word PA(os_hpmc) /* address of handler */ + .word 0 /* length of handler */ + .endm + + /* + * Performance Note: Instructions will be moved up into + * this part of the code later on, once we are sure + * that the tlb miss handlers are close to final form. + */ + + /* Register definitions for tlb miss handler macros */ + + va = r8 /* virtual address for which the trap occurred */ + spc = r24 /* space for which the trap occurred */ + +#ifndef CONFIG_64BIT + + /* + * itlb miss interruption handler (parisc 1.1 - 32 bit) + */ + + .macro itlb_11 code + + mfctl %pcsq, spc + b itlb_miss_11 + mfctl %pcoq, va + + .align 32 + .endm +#endif + + /* + * itlb miss interruption handler (parisc 2.0) + */ + + .macro itlb_20 code + mfctl %pcsq, spc +#ifdef CONFIG_64BIT + b itlb_miss_20w +#else + b itlb_miss_20 +#endif + mfctl %pcoq, va + + .align 32 + .endm + +#ifndef CONFIG_64BIT + /* + * naitlb miss interruption handler (parisc 1.1 - 32 bit) + */ + + .macro naitlb_11 code + + mfctl %isr,spc + b naitlb_miss_11 + mfctl %ior,va + + .align 32 + .endm +#endif + + /* + * naitlb miss interruption handler (parisc 2.0) + */ + + .macro naitlb_20 code + + mfctl %isr,spc +#ifdef CONFIG_64BIT + b naitlb_miss_20w +#else + b naitlb_miss_20 +#endif + mfctl %ior,va + + .align 32 + .endm + +#ifndef CONFIG_64BIT + /* + * dtlb miss interruption handler (parisc 1.1 - 32 bit) + */ + + .macro dtlb_11 code + + mfctl %isr, spc + b dtlb_miss_11 + mfctl %ior, va + + .align 32 + .endm +#endif + + /* + * dtlb miss interruption handler (parisc 2.0) + */ + + .macro dtlb_20 code + + mfctl %isr, spc +#ifdef CONFIG_64BIT + b dtlb_miss_20w +#else + b dtlb_miss_20 +#endif + mfctl %ior, va + + .align 32 + .endm + +#ifndef CONFIG_64BIT + /* nadtlb miss interruption handler (parisc 1.1 - 32 bit) */ + + .macro nadtlb_11 code + + mfctl %isr,spc + b nadtlb_miss_11 + mfctl %ior,va + + .align 32 + .endm +#endif + + /* nadtlb miss interruption handler (parisc 2.0) */ + + .macro nadtlb_20 code + + mfctl %isr,spc +#ifdef CONFIG_64BIT + b nadtlb_miss_20w +#else + b nadtlb_miss_20 +#endif + mfctl %ior,va + + .align 32 + .endm + +#ifndef CONFIG_64BIT + /* + * dirty bit trap interruption handler (parisc 1.1 - 32 bit) + */ + + .macro dbit_11 code + + mfctl %isr,spc + b dbit_trap_11 + mfctl %ior,va + + .align 32 + .endm +#endif + + /* + * dirty bit trap interruption handler (parisc 2.0) + */ + + .macro dbit_20 code + + mfctl %isr,spc +#ifdef CONFIG_64BIT + b dbit_trap_20w +#else + b dbit_trap_20 +#endif + mfctl %ior,va + + .align 32 + .endm + + /* In LP64, the space contains part of the upper 32 bits of the + * fault. We have to extract this and place it in the va, + * zeroing the corresponding bits in the space register */ + .macro space_adjust spc,va,tmp +#ifdef CONFIG_64BIT + extrd,u \spc,63,SPACEID_SHIFT,\tmp + depd %r0,63,SPACEID_SHIFT,\spc + depd \tmp,31,SPACEID_SHIFT,\va +#endif + .endm + + .import swapper_pg_dir,code + + /* Get the pgd. For faults on space zero (kernel space), this + * is simply swapper_pg_dir. For user space faults, the + * pgd is stored in %cr25 */ + .macro get_pgd spc,reg + ldil L%PA(swapper_pg_dir),\reg + ldo R%PA(swapper_pg_dir)(\reg),\reg + or,COND(=) %r0,\spc,%r0 + mfctl %cr25,\reg + .endm + + /* + space_check(spc,tmp,fault) + + spc - The space we saw the fault with. + tmp - The place to store the current space. + fault - Function to call on failure. + + Only allow faults on different spaces from the + currently active one if we're the kernel + + */ + .macro space_check spc,tmp,fault + mfsp %sr7,\tmp + or,COND(<>) %r0,\spc,%r0 /* user may execute gateway page + * as kernel, so defeat the space + * check if it is */ + copy \spc,\tmp + or,COND(=) %r0,\tmp,%r0 /* nullify if executing as kernel */ + cmpb,COND(<>),n \tmp,\spc,\fault + .endm + + /* Look up a PTE in a 2-Level scheme (faulting at each + * level if the entry isn't present + * + * NOTE: we use ldw even for LP64, since the short pointers + * can address up to 1TB + */ + .macro L2_ptep pmd,pte,index,va,fault +#if CONFIG_PGTABLE_LEVELS == 3 + extru \va,31-ASM_PMD_SHIFT,ASM_BITS_PER_PMD,\index +#else +# if defined(CONFIG_64BIT) + extrd,u \va,63-ASM_PGDIR_SHIFT,ASM_BITS_PER_PGD,\index + #else + # if PAGE_SIZE > 4096 + extru \va,31-ASM_PGDIR_SHIFT,32-ASM_PGDIR_SHIFT,\index + # else + extru \va,31-ASM_PGDIR_SHIFT,ASM_BITS_PER_PGD,\index + # endif +# endif +#endif + dep %r0,31,PAGE_SHIFT,\pmd /* clear offset */ + copy %r0,\pte + ldw,s \index(\pmd),\pmd + bb,>=,n \pmd,_PxD_PRESENT_BIT,\fault + dep %r0,31,PxD_FLAG_SHIFT,\pmd /* clear flags */ + copy \pmd,%r9 + SHLREG %r9,PxD_VALUE_SHIFT,\pmd + extru \va,31-PAGE_SHIFT,ASM_BITS_PER_PTE,\index + dep %r0,31,PAGE_SHIFT,\pmd /* clear offset */ + shladd \index,BITS_PER_PTE_ENTRY,\pmd,\pmd + LDREG %r0(\pmd),\pte /* pmd is now pte */ + bb,>=,n \pte,_PAGE_PRESENT_BIT,\fault + .endm + + /* Look up PTE in a 3-Level scheme. + * + * Here we implement a Hybrid L2/L3 scheme: we allocate the + * first pmd adjacent to the pgd. This means that we can + * subtract a constant offset to get to it. The pmd and pgd + * sizes are arranged so that a single pmd covers 4GB (giving + * a full LP64 process access to 8TB) so our lookups are + * effectively L2 for the first 4GB of the kernel (i.e. for + * all ILP32 processes and all the kernel for machines with + * under 4GB of memory) */ + .macro L3_ptep pgd,pte,index,va,fault +#if CONFIG_PGTABLE_LEVELS == 3 /* we might have a 2-Level scheme, e.g. with 16kb page size */ + extrd,u \va,63-ASM_PGDIR_SHIFT,ASM_BITS_PER_PGD,\index + copy %r0,\pte + extrd,u,*= \va,63-ASM_PGDIR_SHIFT,64-ASM_PGDIR_SHIFT,%r0 + ldw,s \index(\pgd),\pgd + extrd,u,*= \va,63-ASM_PGDIR_SHIFT,64-ASM_PGDIR_SHIFT,%r0 + bb,>=,n \pgd,_PxD_PRESENT_BIT,\fault + extrd,u,*= \va,63-ASM_PGDIR_SHIFT,64-ASM_PGDIR_SHIFT,%r0 + shld \pgd,PxD_VALUE_SHIFT,\index + extrd,u,*= \va,63-ASM_PGDIR_SHIFT,64-ASM_PGDIR_SHIFT,%r0 + copy \index,\pgd + extrd,u,*<> \va,63-ASM_PGDIR_SHIFT,64-ASM_PGDIR_SHIFT,%r0 + ldo ASM_PGD_PMD_OFFSET(\pgd),\pgd +#endif + L2_ptep \pgd,\pte,\index,\va,\fault + .endm + + /* Acquire pa_dbit_lock lock. */ + .macro dbit_lock spc,tmp,tmp1 +#ifdef CONFIG_SMP + cmpib,COND(=),n 0,\spc,2f + load32 PA(pa_dbit_lock),\tmp +1: LDCW 0(\tmp),\tmp1 + cmpib,COND(=) 0,\tmp1,1b + nop +2: +#endif + .endm + + /* Release pa_dbit_lock lock without reloading lock address. */ + .macro dbit_unlock0 spc,tmp +#ifdef CONFIG_SMP + or,COND(=) %r0,\spc,%r0 + stw \spc,0(\tmp) +#endif + .endm + + /* Release pa_dbit_lock lock. */ + .macro dbit_unlock1 spc,tmp +#ifdef CONFIG_SMP + load32 PA(pa_dbit_lock),\tmp + dbit_unlock0 \spc,\tmp +#endif + .endm + + /* Set the _PAGE_ACCESSED bit of the PTE. Be clever and + * don't needlessly dirty the cache line if it was already set */ + .macro update_ptep spc,ptep,pte,tmp,tmp1 +#ifdef CONFIG_SMP + or,COND(=) %r0,\spc,%r0 + LDREG 0(\ptep),\pte +#endif + ldi _PAGE_ACCESSED,\tmp1 + or \tmp1,\pte,\tmp + and,COND(<>) \tmp1,\pte,%r0 + STREG \tmp,0(\ptep) + .endm + + /* Set the dirty bit (and accessed bit). No need to be + * clever, this is only used from the dirty fault */ + .macro update_dirty spc,ptep,pte,tmp +#ifdef CONFIG_SMP + or,COND(=) %r0,\spc,%r0 + LDREG 0(\ptep),\pte +#endif + ldi _PAGE_ACCESSED|_PAGE_DIRTY,\tmp + or \tmp,\pte,\pte + STREG \pte,0(\ptep) + .endm + + /* bitshift difference between a PFN (based on kernel's PAGE_SIZE) + * to a CPU TLB 4k PFN (4k => 12 bits to shift) */ + #define PAGE_ADD_SHIFT (PAGE_SHIFT-12) + + /* Drop prot bits and convert to page addr for iitlbt and idtlbt */ + .macro convert_for_tlb_insert20 pte + extrd,u \pte,(63-ASM_PFN_PTE_SHIFT)+(63-58)+PAGE_ADD_SHIFT,\ + 64-PAGE_SHIFT-PAGE_ADD_SHIFT,\pte + depdi _PAGE_SIZE_ENCODING_DEFAULT,63,\ + (63-58)+PAGE_ADD_SHIFT,\pte + .endm + + /* Convert the pte and prot to tlb insertion values. How + * this happens is quite subtle, read below */ + .macro make_insert_tlb spc,pte,prot + space_to_prot \spc \prot /* create prot id from space */ + /* The following is the real subtlety. This is depositing + * T <-> _PAGE_REFTRAP + * D <-> _PAGE_DIRTY + * B <-> _PAGE_DMB (memory break) + * + * Then incredible subtlety: The access rights are + * _PAGE_GATEWAY, _PAGE_EXEC and _PAGE_WRITE + * See 3-14 of the parisc 2.0 manual + * + * Finally, _PAGE_READ goes in the top bit of PL1 (so we + * trigger an access rights trap in user space if the user + * tries to read an unreadable page */ + depd \pte,8,7,\prot + + /* PAGE_USER indicates the page can be read with user privileges, + * so deposit X1|11 to PL1|PL2 (remember the upper bit of PL1 + * contains _PAGE_READ) */ + extrd,u,*= \pte,_PAGE_USER_BIT+32,1,%r0 + depdi 7,11,3,\prot + /* If we're a gateway page, drop PL2 back to zero for promotion + * to kernel privilege (so we can execute the page as kernel). + * Any privilege promotion page always denys read and write */ + extrd,u,*= \pte,_PAGE_GATEWAY_BIT+32,1,%r0 + depd %r0,11,2,\prot /* If Gateway, Set PL2 to 0 */ + + /* Enforce uncacheable pages. + * This should ONLY be use for MMIO on PA 2.0 machines. + * Memory/DMA is cache coherent on all PA2.0 machines we support + * (that means T-class is NOT supported) and the memory controllers + * on most of those machines only handles cache transactions. + */ + extrd,u,*= \pte,_PAGE_NO_CACHE_BIT+32,1,%r0 + depdi 1,12,1,\prot + + /* Drop prot bits and convert to page addr for iitlbt and idtlbt */ + convert_for_tlb_insert20 \pte + .endm + + /* Identical macro to make_insert_tlb above, except it + * makes the tlb entry for the differently formatted pa11 + * insertion instructions */ + .macro make_insert_tlb_11 spc,pte,prot + zdep \spc,30,15,\prot + dep \pte,8,7,\prot + extru,= \pte,_PAGE_NO_CACHE_BIT,1,%r0 + depi 1,12,1,\prot + extru,= \pte,_PAGE_USER_BIT,1,%r0 + depi 7,11,3,\prot /* Set for user space (1 rsvd for read) */ + extru,= \pte,_PAGE_GATEWAY_BIT,1,%r0 + depi 0,11,2,\prot /* If Gateway, Set PL2 to 0 */ + + /* Get rid of prot bits and convert to page addr for iitlba */ + + depi 0,31,ASM_PFN_PTE_SHIFT,\pte + SHRREG \pte,(ASM_PFN_PTE_SHIFT-(31-26)),\pte + .endm + + /* This is for ILP32 PA2.0 only. The TLB insertion needs + * to extend into I/O space if the address is 0xfXXXXXXX + * so we extend the f's into the top word of the pte in + * this case */ + .macro f_extend pte,tmp + extrd,s \pte,42,4,\tmp + addi,<> 1,\tmp,%r0 + extrd,s \pte,63,25,\pte + .endm + + /* The alias region is an 8MB aligned 16MB to do clear and + * copy user pages at addresses congruent with the user + * virtual address. + * + * To use the alias page, you set %r26 up with the to TLB + * entry (identifying the physical page) and %r23 up with + * the from tlb entry (or nothing if only a to entry---for + * clear_user_page_asm) */ + .macro do_alias spc,tmp,tmp1,va,pte,prot,fault,patype + cmpib,COND(<>),n 0,\spc,\fault + ldil L%(TMPALIAS_MAP_START),\tmp +#if defined(CONFIG_64BIT) && (TMPALIAS_MAP_START >= 0x80000000) + /* on LP64, ldi will sign extend into the upper 32 bits, + * which is behaviour we don't want */ + depdi 0,31,32,\tmp +#endif + copy \va,\tmp1 + depi 0,31,23,\tmp1 + cmpb,COND(<>),n \tmp,\tmp1,\fault + mfctl %cr19,\tmp /* iir */ + /* get the opcode (first six bits) into \tmp */ + extrw,u \tmp,5,6,\tmp + /* + * Only setting the T bit prevents data cache movein + * Setting access rights to zero prevents instruction cache movein + * + * Note subtlety here: _PAGE_GATEWAY, _PAGE_EXEC and _PAGE_WRITE go + * to type field and _PAGE_READ goes to top bit of PL1 + */ + ldi (_PAGE_REFTRAP|_PAGE_READ|_PAGE_WRITE),\prot + /* + * so if the opcode is one (i.e. this is a memory management + * instruction) nullify the next load so \prot is only T. + * Otherwise this is a normal data operation + */ + cmpiclr,= 0x01,\tmp,%r0 + ldi (_PAGE_DIRTY|_PAGE_READ|_PAGE_WRITE),\prot +.ifc \patype,20 + depd,z \prot,8,7,\prot +.else +.ifc \patype,11 + depw,z \prot,8,7,\prot +.else + .error "undefined PA type to do_alias" +.endif +.endif + /* + * OK, it is in the temp alias region, check whether "from" or "to". + * Check "subtle" note in pacache.S re: r23/r26. + */ +#ifdef CONFIG_64BIT + extrd,u,*= \va,41,1,%r0 +#else + extrw,u,= \va,9,1,%r0 +#endif + or,COND(tr) %r23,%r0,\pte + or %r26,%r0,\pte + .endm + + + /* + * Align fault_vector_20 on 4K boundary so that both + * fault_vector_11 and fault_vector_20 are on the + * same page. This is only necessary as long as we + * write protect the kernel text, which we may stop + * doing once we use large page translations to cover + * the static part of the kernel address space. + */ + + .text + + .align 4096 + +ENTRY(fault_vector_20) + /* First vector is invalid (0) */ + .ascii "cows can fly" + .byte 0 + .align 32 + + hpmc 1 + def 2 + def 3 + extint 4 + def 5 + itlb_20 6 + def 7 + def 8 + def 9 + def 10 + def 11 + def 12 + def 13 + def 14 + dtlb_20 15 + naitlb_20 16 + nadtlb_20 17 + def 18 + def 19 + dbit_20 20 + def 21 + def 22 + def 23 + def 24 + def 25 + def 26 + def 27 + def 28 + def 29 + def 30 + def 31 +END(fault_vector_20) + +#ifndef CONFIG_64BIT + + .align 2048 + +ENTRY(fault_vector_11) + /* First vector is invalid (0) */ + .ascii "cows can fly" + .byte 0 + .align 32 + + hpmc 1 + def 2 + def 3 + extint 4 + def 5 + itlb_11 6 + def 7 + def 8 + def 9 + def 10 + def 11 + def 12 + def 13 + def 14 + dtlb_11 15 + naitlb_11 16 + nadtlb_11 17 + def 18 + def 19 + dbit_11 20 + def 21 + def 22 + def 23 + def 24 + def 25 + def 26 + def 27 + def 28 + def 29 + def 30 + def 31 +END(fault_vector_11) + +#endif + /* Fault vector is separately protected and *must* be on its own page */ + .align PAGE_SIZE +ENTRY(end_fault_vector) + + .import handle_interruption,code + .import do_cpu_irq_mask,code + + /* + * Child Returns here + * + * copy_thread moved args into task save area. + */ + +ENTRY(ret_from_kernel_thread) + + /* Call schedule_tail first though */ + BL schedule_tail, %r2 + nop + + LDREG TI_TASK-THREAD_SZ_ALGN-FRAME_SIZE(%r30), %r1 + LDREG TASK_PT_GR25(%r1), %r26 +#ifdef CONFIG_64BIT + LDREG TASK_PT_GR27(%r1), %r27 +#endif + LDREG TASK_PT_GR26(%r1), %r1 + ble 0(%sr7, %r1) + copy %r31, %r2 + b finish_child_return + nop +ENDPROC(ret_from_kernel_thread) + + + /* + * struct task_struct *_switch_to(struct task_struct *prev, + * struct task_struct *next) + * + * switch kernel stacks and return prev */ +ENTRY(_switch_to) + STREG %r2, -RP_OFFSET(%r30) + + callee_save_float + callee_save + + load32 _switch_to_ret, %r2 + + STREG %r2, TASK_PT_KPC(%r26) + LDREG TASK_PT_KPC(%r25), %r2 + + STREG %r30, TASK_PT_KSP(%r26) + LDREG TASK_PT_KSP(%r25), %r30 + LDREG TASK_THREAD_INFO(%r25), %r25 + bv %r0(%r2) + mtctl %r25,%cr30 + +_switch_to_ret: + mtctl %r0, %cr0 /* Needed for single stepping */ + callee_rest + callee_rest_float + + LDREG -RP_OFFSET(%r30), %r2 + bv %r0(%r2) + copy %r26, %r28 +ENDPROC(_switch_to) + + /* + * Common rfi return path for interruptions, kernel execve, and + * sys_rt_sigreturn (sometimes). The sys_rt_sigreturn syscall will + * return via this path if the signal was received when the process + * was running; if the process was blocked on a syscall then the + * normal syscall_exit path is used. All syscalls for traced + * proceses exit via intr_restore. + * + * XXX If any syscalls that change a processes space id ever exit + * this way, then we will need to copy %sr3 in to PT_SR[3..7], and + * adjust IASQ[0..1]. + * + */ + + .align PAGE_SIZE + +ENTRY(syscall_exit_rfi) + mfctl %cr30,%r16 + LDREG TI_TASK(%r16), %r16 /* thread_info -> task_struct */ + ldo TASK_REGS(%r16),%r16 + /* Force iaoq to userspace, as the user has had access to our current + * context via sigcontext. Also Filter the PSW for the same reason. + */ + LDREG PT_IAOQ0(%r16),%r19 + depi 3,31,2,%r19 + STREG %r19,PT_IAOQ0(%r16) + LDREG PT_IAOQ1(%r16),%r19 + depi 3,31,2,%r19 + STREG %r19,PT_IAOQ1(%r16) + LDREG PT_PSW(%r16),%r19 + load32 USER_PSW_MASK,%r1 +#ifdef CONFIG_64BIT + load32 USER_PSW_HI_MASK,%r20 + depd %r20,31,32,%r1 +#endif + and %r19,%r1,%r19 /* Mask out bits that user shouldn't play with */ + load32 USER_PSW,%r1 + or %r19,%r1,%r19 /* Make sure default USER_PSW bits are set */ + STREG %r19,PT_PSW(%r16) + + /* + * If we aren't being traced, we never saved space registers + * (we don't store them in the sigcontext), so set them + * to "proper" values now (otherwise we'll wind up restoring + * whatever was last stored in the task structure, which might + * be inconsistent if an interrupt occurred while on the gateway + * page). Note that we may be "trashing" values the user put in + * them, but we don't support the user changing them. + */ + + STREG %r0,PT_SR2(%r16) + mfsp %sr3,%r19 + STREG %r19,PT_SR0(%r16) + STREG %r19,PT_SR1(%r16) + STREG %r19,PT_SR3(%r16) + STREG %r19,PT_SR4(%r16) + STREG %r19,PT_SR5(%r16) + STREG %r19,PT_SR6(%r16) + STREG %r19,PT_SR7(%r16) + +intr_return: + /* check for reschedule */ + mfctl %cr30,%r1 + LDREG TI_FLAGS(%r1),%r19 /* sched.h: TIF_NEED_RESCHED */ + bb,<,n %r19,31-TIF_NEED_RESCHED,intr_do_resched /* forward */ + + .import do_notify_resume,code +intr_check_sig: + /* As above */ + mfctl %cr30,%r1 + LDREG TI_FLAGS(%r1),%r19 + ldi (_TIF_SIGPENDING|_TIF_NOTIFY_RESUME), %r20 + and,COND(<>) %r19, %r20, %r0 + b,n intr_restore /* skip past if we've nothing to do */ + + /* This check is critical to having LWS + * working. The IASQ is zero on the gateway + * page and we cannot deliver any signals until + * we get off the gateway page. + * + * Only do signals if we are returning to user space + */ + LDREG PT_IASQ0(%r16), %r20 + cmpib,COND(=),n 0,%r20,intr_restore /* backward */ + LDREG PT_IASQ1(%r16), %r20 + cmpib,COND(=),n 0,%r20,intr_restore /* backward */ + + /* NOTE: We need to enable interrupts if we have to deliver + * signals. We used to do this earlier but it caused kernel + * stack overflows. */ + ssm PSW_SM_I, %r0 + + copy %r0, %r25 /* long in_syscall = 0 */ +#ifdef CONFIG_64BIT + ldo -16(%r30),%r29 /* Reference param save area */ +#endif + + BL do_notify_resume,%r2 + copy %r16, %r26 /* struct pt_regs *regs */ + + b,n intr_check_sig + +intr_restore: + copy %r16,%r29 + ldo PT_FR31(%r29),%r1 + rest_fp %r1 + rest_general %r29 + + /* inverse of virt_map */ + pcxt_ssm_bug + rsm PSW_SM_QUIET,%r0 /* prepare for rfi */ + tophys_r1 %r29 + + /* Restore space id's and special cr's from PT_REGS + * structure pointed to by r29 + */ + rest_specials %r29 + + /* IMPORTANT: rest_stack restores r29 last (we are using it)! + * It also restores r1 and r30. + */ + rest_stack + + rfi + nop + +#ifndef CONFIG_PREEMPT +# define intr_do_preempt intr_restore +#endif /* !CONFIG_PREEMPT */ + + .import schedule,code +intr_do_resched: + /* Only call schedule on return to userspace. If we're returning + * to kernel space, we may schedule if CONFIG_PREEMPT, otherwise + * we jump back to intr_restore. + */ + LDREG PT_IASQ0(%r16), %r20 + cmpib,COND(=) 0, %r20, intr_do_preempt + nop + LDREG PT_IASQ1(%r16), %r20 + cmpib,COND(=) 0, %r20, intr_do_preempt + nop + + /* NOTE: We need to enable interrupts if we schedule. We used + * to do this earlier but it caused kernel stack overflows. */ + ssm PSW_SM_I, %r0 + +#ifdef CONFIG_64BIT + ldo -16(%r30),%r29 /* Reference param save area */ +#endif + + ldil L%intr_check_sig, %r2 +#ifndef CONFIG_64BIT + b schedule +#else + load32 schedule, %r20 + bv %r0(%r20) +#endif + ldo R%intr_check_sig(%r2), %r2 + + /* preempt the current task on returning to kernel + * mode from an interrupt, iff need_resched is set, + * and preempt_count is 0. otherwise, we continue on + * our merry way back to the current running task. + */ +#ifdef CONFIG_PREEMPT + .import preempt_schedule_irq,code +intr_do_preempt: + rsm PSW_SM_I, %r0 /* disable interrupts */ + + /* current_thread_info()->preempt_count */ + mfctl %cr30, %r1 + LDREG TI_PRE_COUNT(%r1), %r19 + cmpib,COND(<>) 0, %r19, intr_restore /* if preempt_count > 0 */ + nop /* prev insn branched backwards */ + + /* check if we interrupted a critical path */ + LDREG PT_PSW(%r16), %r20 + bb,<,n %r20, 31 - PSW_SM_I, intr_restore + nop + + BL preempt_schedule_irq, %r2 + nop + + b,n intr_restore /* ssm PSW_SM_I done by intr_restore */ +#endif /* CONFIG_PREEMPT */ + + /* + * External interrupts. + */ + +intr_extint: + cmpib,COND(=),n 0,%r16,1f + + get_stack_use_cr30 + b,n 2f + +1: + get_stack_use_r30 +2: + save_specials %r29 + virt_map + save_general %r29 + + ldo PT_FR0(%r29), %r24 + save_fp %r24 + + loadgp + + copy %r29, %r26 /* arg0 is pt_regs */ + copy %r29, %r16 /* save pt_regs */ + + ldil L%intr_return, %r2 + +#ifdef CONFIG_64BIT + ldo -16(%r30),%r29 /* Reference param save area */ +#endif + + b do_cpu_irq_mask + ldo R%intr_return(%r2), %r2 /* return to intr_return, not here */ +ENDPROC(syscall_exit_rfi) + + + /* Generic interruptions (illegal insn, unaligned, page fault, etc) */ + +ENTRY(intr_save) /* for os_hpmc */ + mfsp %sr7,%r16 + cmpib,COND(=),n 0,%r16,1f + get_stack_use_cr30 + b 2f + copy %r8,%r26 + +1: + get_stack_use_r30 + copy %r8,%r26 + +2: + save_specials %r29 + + /* If this trap is a itlb miss, skip saving/adjusting isr/ior */ + + /* + * FIXME: 1) Use a #define for the hardwired "6" below (and in + * traps.c. + * 2) Once we start executing code above 4 Gb, we need + * to adjust iasq/iaoq here in the same way we + * adjust isr/ior below. + */ + + cmpib,COND(=),n 6,%r26,skip_save_ior + + + mfctl %cr20, %r16 /* isr */ + nop /* serialize mfctl on PA 2.0 to avoid 4 cycle penalty */ + mfctl %cr21, %r17 /* ior */ + + +#ifdef CONFIG_64BIT + /* + * If the interrupted code was running with W bit off (32 bit), + * clear the b bits (bits 0 & 1) in the ior. + * save_specials left ipsw value in r8 for us to test. + */ + extrd,u,*<> %r8,PSW_W_BIT,1,%r0 + depdi 0,1,2,%r17 + + /* + * FIXME: This code has hardwired assumptions about the split + * between space bits and offset bits. This will change + * when we allow alternate page sizes. + */ + + /* adjust isr/ior. */ + extrd,u %r16,63,SPACEID_SHIFT,%r1 /* get high bits from isr for ior */ + depd %r1,31,SPACEID_SHIFT,%r17 /* deposit them into ior */ + depdi 0,63,SPACEID_SHIFT,%r16 /* clear them from isr */ +#endif + STREG %r16, PT_ISR(%r29) + STREG %r17, PT_IOR(%r29) + + +skip_save_ior: + virt_map + save_general %r29 + + ldo PT_FR0(%r29), %r25 + save_fp %r25 + + loadgp + + copy %r29, %r25 /* arg1 is pt_regs */ +#ifdef CONFIG_64BIT + ldo -16(%r30),%r29 /* Reference param save area */ +#endif + + ldil L%intr_check_sig, %r2 + copy %r25, %r16 /* save pt_regs */ + + b handle_interruption + ldo R%intr_check_sig(%r2), %r2 +ENDPROC(intr_save) + + + /* + * Note for all tlb miss handlers: + * + * cr24 contains a pointer to the kernel address space + * page directory. + * + * cr25 contains a pointer to the current user address + * space page directory. + * + * sr3 will contain the space id of the user address space + * of the current running thread while that thread is + * running in the kernel. + */ + + /* + * register number allocations. Note that these are all + * in the shadowed registers + */ + + t0 = r1 /* temporary register 0 */ + va = r8 /* virtual address for which the trap occurred */ + t1 = r9 /* temporary register 1 */ + pte = r16 /* pte/phys page # */ + prot = r17 /* prot bits */ + spc = r24 /* space for which the trap occurred */ + ptp = r25 /* page directory/page table pointer */ + +#ifdef CONFIG_64BIT + +dtlb_miss_20w: + space_adjust spc,va,t0 + get_pgd spc,ptp + space_check spc,t0,dtlb_fault + + L3_ptep ptp,pte,t0,va,dtlb_check_alias_20w + + dbit_lock spc,t0,t1 + update_ptep spc,ptp,pte,t0,t1 + + make_insert_tlb spc,pte,prot + + idtlbt pte,prot + dbit_unlock1 spc,t0 + + rfir + nop + +dtlb_check_alias_20w: + do_alias spc,t0,t1,va,pte,prot,dtlb_fault,20 + + idtlbt pte,prot + + rfir + nop + +nadtlb_miss_20w: + space_adjust spc,va,t0 + get_pgd spc,ptp + space_check spc,t0,nadtlb_fault + + L3_ptep ptp,pte,t0,va,nadtlb_check_alias_20w + + dbit_lock spc,t0,t1 + update_ptep spc,ptp,pte,t0,t1 + + make_insert_tlb spc,pte,prot + + idtlbt pte,prot + dbit_unlock1 spc,t0 + + rfir + nop + +nadtlb_check_alias_20w: + do_alias spc,t0,t1,va,pte,prot,nadtlb_emulate,20 + + idtlbt pte,prot + + rfir + nop + +#else + +dtlb_miss_11: + get_pgd spc,ptp + + space_check spc,t0,dtlb_fault + + L2_ptep ptp,pte,t0,va,dtlb_check_alias_11 + + dbit_lock spc,t0,t1 + update_ptep spc,ptp,pte,t0,t1 + + make_insert_tlb_11 spc,pte,prot + + mfsp %sr1,t0 /* Save sr1 so we can use it in tlb inserts */ + mtsp spc,%sr1 + + idtlba pte,(%sr1,va) + idtlbp prot,(%sr1,va) + + mtsp t0, %sr1 /* Restore sr1 */ + dbit_unlock1 spc,t0 + + rfir + nop + +dtlb_check_alias_11: + do_alias spc,t0,t1,va,pte,prot,dtlb_fault,11 + + idtlba pte,(va) + idtlbp prot,(va) + + rfir + nop + +nadtlb_miss_11: + get_pgd spc,ptp + + space_check spc,t0,nadtlb_fault + + L2_ptep ptp,pte,t0,va,nadtlb_check_alias_11 + + dbit_lock spc,t0,t1 + update_ptep spc,ptp,pte,t0,t1 + + make_insert_tlb_11 spc,pte,prot + + + mfsp %sr1,t0 /* Save sr1 so we can use it in tlb inserts */ + mtsp spc,%sr1 + + idtlba pte,(%sr1,va) + idtlbp prot,(%sr1,va) + + mtsp t0, %sr1 /* Restore sr1 */ + dbit_unlock1 spc,t0 + + rfir + nop + +nadtlb_check_alias_11: + do_alias spc,t0,t1,va,pte,prot,nadtlb_emulate,11 + + idtlba pte,(va) + idtlbp prot,(va) + + rfir + nop + +dtlb_miss_20: + space_adjust spc,va,t0 + get_pgd spc,ptp + space_check spc,t0,dtlb_fault + + L2_ptep ptp,pte,t0,va,dtlb_check_alias_20 + + dbit_lock spc,t0,t1 + update_ptep spc,ptp,pte,t0,t1 + + make_insert_tlb spc,pte,prot + + f_extend pte,t0 + + idtlbt pte,prot + dbit_unlock1 spc,t0 + + rfir + nop + +dtlb_check_alias_20: + do_alias spc,t0,t1,va,pte,prot,dtlb_fault,20 + + idtlbt pte,prot + + rfir + nop + +nadtlb_miss_20: + get_pgd spc,ptp + + space_check spc,t0,nadtlb_fault + + L2_ptep ptp,pte,t0,va,nadtlb_check_alias_20 + + dbit_lock spc,t0,t1 + update_ptep spc,ptp,pte,t0,t1 + + make_insert_tlb spc,pte,prot + + f_extend pte,t0 + + idtlbt pte,prot + dbit_unlock1 spc,t0 + + rfir + nop + +nadtlb_check_alias_20: + do_alias spc,t0,t1,va,pte,prot,nadtlb_emulate,20 + + idtlbt pte,prot + + rfir + nop + +#endif + +nadtlb_emulate: + + /* + * Non access misses can be caused by fdc,fic,pdc,lpa,probe and + * probei instructions. We don't want to fault for these + * instructions (not only does it not make sense, it can cause + * deadlocks, since some flushes are done with the mmap + * semaphore held). If the translation doesn't exist, we can't + * insert a translation, so have to emulate the side effects + * of the instruction. Since we don't insert a translation + * we can get a lot of faults during a flush loop, so it makes + * sense to try to do it here with minimum overhead. We only + * emulate fdc,fic,pdc,probew,prober instructions whose base + * and index registers are not shadowed. We defer everything + * else to the "slow" path. + */ + + mfctl %cr19,%r9 /* Get iir */ + + /* PA 2.0 Arch Ref. Book pg 382 has a good description of the insn bits. + Checks for fdc,fdce,pdc,"fic,4f",prober,probeir,probew, probeiw */ + + /* Checks for fdc,fdce,pdc,"fic,4f" only */ + ldi 0x280,%r16 + and %r9,%r16,%r17 + cmpb,<>,n %r16,%r17,nadtlb_probe_check + bb,>=,n %r9,26,nadtlb_nullify /* m bit not set, just nullify */ + BL get_register,%r25 + extrw,u %r9,15,5,%r8 /* Get index register # */ + cmpib,COND(=),n -1,%r1,nadtlb_fault /* have to use slow path */ + copy %r1,%r24 + BL get_register,%r25 + extrw,u %r9,10,5,%r8 /* Get base register # */ + cmpib,COND(=),n -1,%r1,nadtlb_fault /* have to use slow path */ + BL set_register,%r25 + add,l %r1,%r24,%r1 /* doesn't affect c/b bits */ + +nadtlb_nullify: + mfctl %ipsw,%r8 + ldil L%PSW_N,%r9 + or %r8,%r9,%r8 /* Set PSW_N */ + mtctl %r8,%ipsw + + rfir + nop + + /* + When there is no translation for the probe address then we + must nullify the insn and return zero in the target regsiter. + This will indicate to the calling code that it does not have + write/read privileges to this address. + + This should technically work for prober and probew in PA 1.1, + and also probe,r and probe,w in PA 2.0 + + WARNING: USE ONLY NON-SHADOW REGISTERS WITH PROBE INSN! + THE SLOW-PATH EMULATION HAS NOT BEEN WRITTEN YET. + + */ +nadtlb_probe_check: + ldi 0x80,%r16 + and %r9,%r16,%r17 + cmpb,<>,n %r16,%r17,nadtlb_fault /* Must be probe,[rw]*/ + BL get_register,%r25 /* Find the target register */ + extrw,u %r9,31,5,%r8 /* Get target register */ + cmpib,COND(=),n -1,%r1,nadtlb_fault /* have to use slow path */ + BL set_register,%r25 + copy %r0,%r1 /* Write zero to target register */ + b nadtlb_nullify /* Nullify return insn */ + nop + + +#ifdef CONFIG_64BIT +itlb_miss_20w: + + /* + * I miss is a little different, since we allow users to fault + * on the gateway page which is in the kernel address space. + */ + + space_adjust spc,va,t0 + get_pgd spc,ptp + space_check spc,t0,itlb_fault + + L3_ptep ptp,pte,t0,va,itlb_fault + + dbit_lock spc,t0,t1 + update_ptep spc,ptp,pte,t0,t1 + + make_insert_tlb spc,pte,prot + + iitlbt pte,prot + dbit_unlock1 spc,t0 + + rfir + nop + +naitlb_miss_20w: + + /* + * I miss is a little different, since we allow users to fault + * on the gateway page which is in the kernel address space. + */ + + space_adjust spc,va,t0 + get_pgd spc,ptp + space_check spc,t0,naitlb_fault + + L3_ptep ptp,pte,t0,va,naitlb_check_alias_20w + + dbit_lock spc,t0,t1 + update_ptep spc,ptp,pte,t0,t1 + + make_insert_tlb spc,pte,prot + + iitlbt pte,prot + dbit_unlock1 spc,t0 + + rfir + nop + +naitlb_check_alias_20w: + do_alias spc,t0,t1,va,pte,prot,naitlb_fault,20 + + iitlbt pte,prot + + rfir + nop + +#else + +itlb_miss_11: + get_pgd spc,ptp + + space_check spc,t0,itlb_fault + + L2_ptep ptp,pte,t0,va,itlb_fault + + dbit_lock spc,t0,t1 + update_ptep spc,ptp,pte,t0,t1 + + make_insert_tlb_11 spc,pte,prot + + mfsp %sr1,t0 /* Save sr1 so we can use it in tlb inserts */ + mtsp spc,%sr1 + + iitlba pte,(%sr1,va) + iitlbp prot,(%sr1,va) + + mtsp t0, %sr1 /* Restore sr1 */ + dbit_unlock1 spc,t0 + + rfir + nop + +naitlb_miss_11: + get_pgd spc,ptp + + space_check spc,t0,naitlb_fault + + L2_ptep ptp,pte,t0,va,naitlb_check_alias_11 + + dbit_lock spc,t0,t1 + update_ptep spc,ptp,pte,t0,t1 + + make_insert_tlb_11 spc,pte,prot + + mfsp %sr1,t0 /* Save sr1 so we can use it in tlb inserts */ + mtsp spc,%sr1 + + iitlba pte,(%sr1,va) + iitlbp prot,(%sr1,va) + + mtsp t0, %sr1 /* Restore sr1 */ + dbit_unlock1 spc,t0 + + rfir + nop + +naitlb_check_alias_11: + do_alias spc,t0,t1,va,pte,prot,itlb_fault,11 + + iitlba pte,(%sr0, va) + iitlbp prot,(%sr0, va) + + rfir + nop + + +itlb_miss_20: + get_pgd spc,ptp + + space_check spc,t0,itlb_fault + + L2_ptep ptp,pte,t0,va,itlb_fault + + dbit_lock spc,t0,t1 + update_ptep spc,ptp,pte,t0,t1 + + make_insert_tlb spc,pte,prot + + f_extend pte,t0 + + iitlbt pte,prot + dbit_unlock1 spc,t0 + + rfir + nop + +naitlb_miss_20: + get_pgd spc,ptp + + space_check spc,t0,naitlb_fault + + L2_ptep ptp,pte,t0,va,naitlb_check_alias_20 + + dbit_lock spc,t0,t1 + update_ptep spc,ptp,pte,t0,t1 + + make_insert_tlb spc,pte,prot + + f_extend pte,t0 + + iitlbt pte,prot + dbit_unlock1 spc,t0 + + rfir + nop + +naitlb_check_alias_20: + do_alias spc,t0,t1,va,pte,prot,naitlb_fault,20 + + iitlbt pte,prot + + rfir + nop + +#endif + +#ifdef CONFIG_64BIT + +dbit_trap_20w: + space_adjust spc,va,t0 + get_pgd spc,ptp + space_check spc,t0,dbit_fault + + L3_ptep ptp,pte,t0,va,dbit_fault + + dbit_lock spc,t0,t1 + update_dirty spc,ptp,pte,t1 + + make_insert_tlb spc,pte,prot + + idtlbt pte,prot + dbit_unlock0 spc,t0 + + rfir + nop +#else + +dbit_trap_11: + + get_pgd spc,ptp + + space_check spc,t0,dbit_fault + + L2_ptep ptp,pte,t0,va,dbit_fault + + dbit_lock spc,t0,t1 + update_dirty spc,ptp,pte,t1 + + make_insert_tlb_11 spc,pte,prot + + mfsp %sr1,t1 /* Save sr1 so we can use it in tlb inserts */ + mtsp spc,%sr1 + + idtlba pte,(%sr1,va) + idtlbp prot,(%sr1,va) + + mtsp t1, %sr1 /* Restore sr1 */ + dbit_unlock0 spc,t0 + + rfir + nop + +dbit_trap_20: + get_pgd spc,ptp + + space_check spc,t0,dbit_fault + + L2_ptep ptp,pte,t0,va,dbit_fault + + dbit_lock spc,t0,t1 + update_dirty spc,ptp,pte,t1 + + make_insert_tlb spc,pte,prot + + f_extend pte,t1 + + idtlbt pte,prot + dbit_unlock0 spc,t0 + + rfir + nop +#endif + + .import handle_interruption,code + +kernel_bad_space: + b intr_save + ldi 31,%r8 /* Use an unused code */ + +dbit_fault: + b intr_save + ldi 20,%r8 + +itlb_fault: + b intr_save + ldi 6,%r8 + +nadtlb_fault: + b intr_save + ldi 17,%r8 + +naitlb_fault: + b intr_save + ldi 16,%r8 + +dtlb_fault: + b intr_save + ldi 15,%r8 + + /* Register saving semantics for system calls: + + %r1 clobbered by system call macro in userspace + %r2 saved in PT_REGS by gateway page + %r3 - %r18 preserved by C code (saved by signal code) + %r19 - %r20 saved in PT_REGS by gateway page + %r21 - %r22 non-standard syscall args + stored in kernel stack by gateway page + %r23 - %r26 arg3-arg0, saved in PT_REGS by gateway page + %r27 - %r30 saved in PT_REGS by gateway page + %r31 syscall return pointer + */ + + /* Floating point registers (FIXME: what do we do with these?) + + %fr0 - %fr3 status/exception, not preserved + %fr4 - %fr7 arguments + %fr8 - %fr11 not preserved by C code + %fr12 - %fr21 preserved by C code + %fr22 - %fr31 not preserved by C code + */ + + .macro reg_save regs + STREG %r3, PT_GR3(\regs) + STREG %r4, PT_GR4(\regs) + STREG %r5, PT_GR5(\regs) + STREG %r6, PT_GR6(\regs) + STREG %r7, PT_GR7(\regs) + STREG %r8, PT_GR8(\regs) + STREG %r9, PT_GR9(\regs) + STREG %r10,PT_GR10(\regs) + STREG %r11,PT_GR11(\regs) + STREG %r12,PT_GR12(\regs) + STREG %r13,PT_GR13(\regs) + STREG %r14,PT_GR14(\regs) + STREG %r15,PT_GR15(\regs) + STREG %r16,PT_GR16(\regs) + STREG %r17,PT_GR17(\regs) + STREG %r18,PT_GR18(\regs) + .endm + + .macro reg_restore regs + LDREG PT_GR3(\regs), %r3 + LDREG PT_GR4(\regs), %r4 + LDREG PT_GR5(\regs), %r5 + LDREG PT_GR6(\regs), %r6 + LDREG PT_GR7(\regs), %r7 + LDREG PT_GR8(\regs), %r8 + LDREG PT_GR9(\regs), %r9 + LDREG PT_GR10(\regs),%r10 + LDREG PT_GR11(\regs),%r11 + LDREG PT_GR12(\regs),%r12 + LDREG PT_GR13(\regs),%r13 + LDREG PT_GR14(\regs),%r14 + LDREG PT_GR15(\regs),%r15 + LDREG PT_GR16(\regs),%r16 + LDREG PT_GR17(\regs),%r17 + LDREG PT_GR18(\regs),%r18 + .endm + + .macro fork_like name +ENTRY(sys_\name\()_wrapper) + LDREG TI_TASK-THREAD_SZ_ALGN-FRAME_SIZE(%r30), %r1 + ldo TASK_REGS(%r1),%r1 + reg_save %r1 + mfctl %cr27, %r28 + ldil L%sys_\name, %r31 + be R%sys_\name(%sr4,%r31) + STREG %r28, PT_CR27(%r1) +ENDPROC(sys_\name\()_wrapper) + .endm + +fork_like clone +fork_like fork +fork_like vfork + + /* Set the return value for the child */ +ENTRY(child_return) + BL schedule_tail, %r2 + nop +finish_child_return: + LDREG TI_TASK-THREAD_SZ_ALGN-FRAME_SIZE(%r30), %r1 + ldo TASK_REGS(%r1),%r1 /* get pt regs */ + + LDREG PT_CR27(%r1), %r3 + mtctl %r3, %cr27 + reg_restore %r1 + b syscall_exit + copy %r0,%r28 +ENDPROC(child_return) + +ENTRY(sys_rt_sigreturn_wrapper) + LDREG TI_TASK-THREAD_SZ_ALGN-FRAME_SIZE(%r30),%r26 + ldo TASK_REGS(%r26),%r26 /* get pt regs */ + /* Don't save regs, we are going to restore them from sigcontext. */ + STREG %r2, -RP_OFFSET(%r30) +#ifdef CONFIG_64BIT + ldo FRAME_SIZE(%r30), %r30 + BL sys_rt_sigreturn,%r2 + ldo -16(%r30),%r29 /* Reference param save area */ +#else + BL sys_rt_sigreturn,%r2 + ldo FRAME_SIZE(%r30), %r30 +#endif + + ldo -FRAME_SIZE(%r30), %r30 + LDREG -RP_OFFSET(%r30), %r2 + + /* FIXME: I think we need to restore a few more things here. */ + LDREG TI_TASK-THREAD_SZ_ALGN-FRAME_SIZE(%r30),%r1 + ldo TASK_REGS(%r1),%r1 /* get pt regs */ + reg_restore %r1 + + /* If the signal was received while the process was blocked on a + * syscall, then r2 will take us to syscall_exit; otherwise r2 will + * take us to syscall_exit_rfi and on to intr_return. + */ + bv %r0(%r2) + LDREG PT_GR28(%r1),%r28 /* reload original r28 for syscall_exit */ +ENDPROC(sys_rt_sigreturn_wrapper) + +ENTRY(syscall_exit) + /* NOTE: Not all syscalls exit this way. rt_sigreturn will exit + * via syscall_exit_rfi if the signal was received while the process + * was running. + */ + + /* save return value now */ + + mfctl %cr30, %r1 + LDREG TI_TASK(%r1),%r1 + STREG %r28,TASK_PT_GR28(%r1) + + /* Seems to me that dp could be wrong here, if the syscall involved + * calling a module, and nothing got round to restoring dp on return. + */ + loadgp + +syscall_check_resched: + + /* check for reschedule */ + + LDREG TI_FLAGS-THREAD_SZ_ALGN-FRAME_SIZE(%r30),%r19 /* long */ + bb,<,n %r19, 31-TIF_NEED_RESCHED, syscall_do_resched /* forward */ + + .import do_signal,code +syscall_check_sig: + LDREG TI_FLAGS-THREAD_SZ_ALGN-FRAME_SIZE(%r30),%r19 + ldi (_TIF_SIGPENDING|_TIF_NOTIFY_RESUME), %r26 + and,COND(<>) %r19, %r26, %r0 + b,n syscall_restore /* skip past if we've nothing to do */ + +syscall_do_signal: + /* Save callee-save registers (for sigcontext). + * FIXME: After this point the process structure should be + * consistent with all the relevant state of the process + * before the syscall. We need to verify this. + */ + LDREG TI_TASK-THREAD_SZ_ALGN-FRAME_SIZE(%r30),%r1 + ldo TASK_REGS(%r1), %r26 /* struct pt_regs *regs */ + reg_save %r26 + +#ifdef CONFIG_64BIT + ldo -16(%r30),%r29 /* Reference param save area */ +#endif + + BL do_notify_resume,%r2 + ldi 1, %r25 /* long in_syscall = 1 */ + + LDREG TI_TASK-THREAD_SZ_ALGN-FRAME_SIZE(%r30),%r1 + ldo TASK_REGS(%r1), %r20 /* reload pt_regs */ + reg_restore %r20 + + b,n syscall_check_sig + +syscall_restore: + LDREG TI_TASK-THREAD_SZ_ALGN-FRAME_SIZE(%r30),%r1 + + /* Are we being ptraced? */ + ldw TASK_FLAGS(%r1),%r19 + ldi _TIF_SYSCALL_TRACE_MASK,%r2 + and,COND(=) %r19,%r2,%r0 + b,n syscall_restore_rfi + + ldo TASK_PT_FR31(%r1),%r19 /* reload fpregs */ + rest_fp %r19 + + LDREG TASK_PT_SAR(%r1),%r19 /* restore SAR */ + mtsar %r19 + + LDREG TASK_PT_GR2(%r1),%r2 /* restore user rp */ + LDREG TASK_PT_GR19(%r1),%r19 + LDREG TASK_PT_GR20(%r1),%r20 + LDREG TASK_PT_GR21(%r1),%r21 + LDREG TASK_PT_GR22(%r1),%r22 + LDREG TASK_PT_GR23(%r1),%r23 + LDREG TASK_PT_GR24(%r1),%r24 + LDREG TASK_PT_GR25(%r1),%r25 + LDREG TASK_PT_GR26(%r1),%r26 + LDREG TASK_PT_GR27(%r1),%r27 /* restore user dp */ + LDREG TASK_PT_GR28(%r1),%r28 /* syscall return value */ + LDREG TASK_PT_GR29(%r1),%r29 + LDREG TASK_PT_GR31(%r1),%r31 /* restore syscall rp */ + + /* NOTE: We use rsm/ssm pair to make this operation atomic */ + LDREG TASK_PT_GR30(%r1),%r1 /* Get user sp */ + rsm PSW_SM_I, %r0 + copy %r1,%r30 /* Restore user sp */ + mfsp %sr3,%r1 /* Get user space id */ + mtsp %r1,%sr7 /* Restore sr7 */ + ssm PSW_SM_I, %r0 + + /* Set sr2 to zero for userspace syscalls to work. */ + mtsp %r0,%sr2 + mtsp %r1,%sr4 /* Restore sr4 */ + mtsp %r1,%sr5 /* Restore sr5 */ + mtsp %r1,%sr6 /* Restore sr6 */ + + depi 3,31,2,%r31 /* ensure return to user mode. */ + +#ifdef CONFIG_64BIT + /* decide whether to reset the wide mode bit + * + * For a syscall, the W bit is stored in the lowest bit + * of sp. Extract it and reset W if it is zero */ + extrd,u,*<> %r30,63,1,%r1 + rsm PSW_SM_W, %r0 + /* now reset the lowest bit of sp if it was set */ + xor %r30,%r1,%r30 +#endif + be,n 0(%sr3,%r31) /* return to user space */ + + /* We have to return via an RFI, so that PSW T and R bits can be set + * appropriately. + * This sets up pt_regs so we can return via intr_restore, which is not + * the most efficient way of doing things, but it works. + */ +syscall_restore_rfi: + ldo -1(%r0),%r2 /* Set recovery cntr to -1 */ + mtctl %r2,%cr0 /* for immediate trap */ + LDREG TASK_PT_PSW(%r1),%r2 /* Get old PSW */ + ldi 0x0b,%r20 /* Create new PSW */ + depi -1,13,1,%r20 /* C, Q, D, and I bits */ + + /* The values of SINGLESTEP_BIT and BLOCKSTEP_BIT are + * set in thread_info.h and converted to PA bitmap + * numbers in asm-offsets.c */ + + /* if ((%r19.SINGLESTEP_BIT)) { %r20.27=1} */ + extru,= %r19,TIF_SINGLESTEP_PA_BIT,1,%r0 + depi -1,27,1,%r20 /* R bit */ + + /* if ((%r19.BLOCKSTEP_BIT)) { %r20.7=1} */ + extru,= %r19,TIF_BLOCKSTEP_PA_BIT,1,%r0 + depi -1,7,1,%r20 /* T bit */ + + STREG %r20,TASK_PT_PSW(%r1) + + /* Always store space registers, since sr3 can be changed (e.g. fork) */ + + mfsp %sr3,%r25 + STREG %r25,TASK_PT_SR3(%r1) + STREG %r25,TASK_PT_SR4(%r1) + STREG %r25,TASK_PT_SR5(%r1) + STREG %r25,TASK_PT_SR6(%r1) + STREG %r25,TASK_PT_SR7(%r1) + STREG %r25,TASK_PT_IASQ0(%r1) + STREG %r25,TASK_PT_IASQ1(%r1) + + /* XXX W bit??? */ + /* Now if old D bit is clear, it means we didn't save all registers + * on syscall entry, so do that now. This only happens on TRACEME + * calls, or if someone attached to us while we were on a syscall. + * We could make this more efficient by not saving r3-r18, but + * then we wouldn't be able to use the common intr_restore path. + * It is only for traced processes anyway, so performance is not + * an issue. + */ + bb,< %r2,30,pt_regs_ok /* Branch if D set */ + ldo TASK_REGS(%r1),%r25 + reg_save %r25 /* Save r3 to r18 */ + + /* Save the current sr */ + mfsp %sr0,%r2 + STREG %r2,TASK_PT_SR0(%r1) + + /* Save the scratch sr */ + mfsp %sr1,%r2 + STREG %r2,TASK_PT_SR1(%r1) + + /* sr2 should be set to zero for userspace syscalls */ + STREG %r0,TASK_PT_SR2(%r1) + + LDREG TASK_PT_GR31(%r1),%r2 + depi 3,31,2,%r2 /* ensure return to user mode. */ + STREG %r2,TASK_PT_IAOQ0(%r1) + ldo 4(%r2),%r2 + STREG %r2,TASK_PT_IAOQ1(%r1) + b intr_restore + copy %r25,%r16 + +pt_regs_ok: + LDREG TASK_PT_IAOQ0(%r1),%r2 + depi 3,31,2,%r2 /* ensure return to user mode. */ + STREG %r2,TASK_PT_IAOQ0(%r1) + LDREG TASK_PT_IAOQ1(%r1),%r2 + depi 3,31,2,%r2 + STREG %r2,TASK_PT_IAOQ1(%r1) + b intr_restore + copy %r25,%r16 + + .import schedule,code +syscall_do_resched: + BL schedule,%r2 +#ifdef CONFIG_64BIT + ldo -16(%r30),%r29 /* Reference param save area */ +#else + nop +#endif + b syscall_check_resched /* if resched, we start over again */ + nop +ENDPROC(syscall_exit) + + +#ifdef CONFIG_FUNCTION_TRACER + .import ftrace_function_trampoline,code +ENTRY(_mcount) + copy %r3, %arg2 + b ftrace_function_trampoline + nop +ENDPROC(_mcount) + +ENTRY(return_to_handler) + load32 return_trampoline, %rp + copy %ret0, %arg0 + copy %ret1, %arg1 + b ftrace_return_to_handler + nop +return_trampoline: + copy %ret0, %rp + copy %r23, %ret0 + copy %r24, %ret1 + +.globl ftrace_stub +ftrace_stub: + bv %r0(%rp) + nop +ENDPROC(return_to_handler) +#endif /* CONFIG_FUNCTION_TRACER */ + +#ifdef CONFIG_IRQSTACKS +/* void call_on_stack(unsigned long param1, void *func, + unsigned long new_stack) */ +ENTRY(call_on_stack) + copy %sp, %r1 + + /* Regarding the HPPA calling conventions for function pointers, + we assume the PIC register is not changed across call. For + CONFIG_64BIT, the argument pointer is left to point at the + argument region allocated for the call to call_on_stack. */ +# ifdef CONFIG_64BIT + /* Switch to new stack. We allocate two 128 byte frames. */ + ldo 256(%arg2), %sp + /* Save previous stack pointer and return pointer in frame marker */ + STREG %rp, -144(%sp) + /* Calls always use function descriptor */ + LDREG 16(%arg1), %arg1 + bve,l (%arg1), %rp + STREG %r1, -136(%sp) + LDREG -144(%sp), %rp + bve (%rp) + LDREG -136(%sp), %sp +# else + /* Switch to new stack. We allocate two 64 byte frames. */ + ldo 128(%arg2), %sp + /* Save previous stack pointer and return pointer in frame marker */ + STREG %r1, -68(%sp) + STREG %rp, -84(%sp) + /* Calls use function descriptor if PLABEL bit is set */ + bb,>=,n %arg1, 30, 1f + depwi 0,31,2, %arg1 + LDREG 0(%arg1), %arg1 +1: + be,l 0(%sr4,%arg1), %sr0, %r31 + copy %r31, %rp + LDREG -84(%sp), %rp + bv (%rp) + LDREG -68(%sp), %sp +# endif /* CONFIG_64BIT */ +ENDPROC(call_on_stack) +#endif /* CONFIG_IRQSTACKS */ + +get_register: + /* + * get_register is used by the non access tlb miss handlers to + * copy the value of the general register specified in r8 into + * r1. This routine can't be used for shadowed registers, since + * the rfir will restore the original value. So, for the shadowed + * registers we put a -1 into r1 to indicate that the register + * should not be used (the register being copied could also have + * a -1 in it, but that is OK, it just means that we will have + * to use the slow path instead). + */ + blr %r8,%r0 + nop + bv %r0(%r25) /* r0 */ + copy %r0,%r1 + bv %r0(%r25) /* r1 - shadowed */ + ldi -1,%r1 + bv %r0(%r25) /* r2 */ + copy %r2,%r1 + bv %r0(%r25) /* r3 */ + copy %r3,%r1 + bv %r0(%r25) /* r4 */ + copy %r4,%r1 + bv %r0(%r25) /* r5 */ + copy %r5,%r1 + bv %r0(%r25) /* r6 */ + copy %r6,%r1 + bv %r0(%r25) /* r7 */ + copy %r7,%r1 + bv %r0(%r25) /* r8 - shadowed */ + ldi -1,%r1 + bv %r0(%r25) /* r9 - shadowed */ + ldi -1,%r1 + bv %r0(%r25) /* r10 */ + copy %r10,%r1 + bv %r0(%r25) /* r11 */ + copy %r11,%r1 + bv %r0(%r25) /* r12 */ + copy %r12,%r1 + bv %r0(%r25) /* r13 */ + copy %r13,%r1 + bv %r0(%r25) /* r14 */ + copy %r14,%r1 + bv %r0(%r25) /* r15 */ + copy %r15,%r1 + bv %r0(%r25) /* r16 - shadowed */ + ldi -1,%r1 + bv %r0(%r25) /* r17 - shadowed */ + ldi -1,%r1 + bv %r0(%r25) /* r18 */ + copy %r18,%r1 + bv %r0(%r25) /* r19 */ + copy %r19,%r1 + bv %r0(%r25) /* r20 */ + copy %r20,%r1 + bv %r0(%r25) /* r21 */ + copy %r21,%r1 + bv %r0(%r25) /* r22 */ + copy %r22,%r1 + bv %r0(%r25) /* r23 */ + copy %r23,%r1 + bv %r0(%r25) /* r24 - shadowed */ + ldi -1,%r1 + bv %r0(%r25) /* r25 - shadowed */ + ldi -1,%r1 + bv %r0(%r25) /* r26 */ + copy %r26,%r1 + bv %r0(%r25) /* r27 */ + copy %r27,%r1 + bv %r0(%r25) /* r28 */ + copy %r28,%r1 + bv %r0(%r25) /* r29 */ + copy %r29,%r1 + bv %r0(%r25) /* r30 */ + copy %r30,%r1 + bv %r0(%r25) /* r31 */ + copy %r31,%r1 + + +set_register: + /* + * set_register is used by the non access tlb miss handlers to + * copy the value of r1 into the general register specified in + * r8. + */ + blr %r8,%r0 + nop + bv %r0(%r25) /* r0 (silly, but it is a place holder) */ + copy %r1,%r0 + bv %r0(%r25) /* r1 */ + copy %r1,%r1 + bv %r0(%r25) /* r2 */ + copy %r1,%r2 + bv %r0(%r25) /* r3 */ + copy %r1,%r3 + bv %r0(%r25) /* r4 */ + copy %r1,%r4 + bv %r0(%r25) /* r5 */ + copy %r1,%r5 + bv %r0(%r25) /* r6 */ + copy %r1,%r6 + bv %r0(%r25) /* r7 */ + copy %r1,%r7 + bv %r0(%r25) /* r8 */ + copy %r1,%r8 + bv %r0(%r25) /* r9 */ + copy %r1,%r9 + bv %r0(%r25) /* r10 */ + copy %r1,%r10 + bv %r0(%r25) /* r11 */ + copy %r1,%r11 + bv %r0(%r25) /* r12 */ + copy %r1,%r12 + bv %r0(%r25) /* r13 */ + copy %r1,%r13 + bv %r0(%r25) /* r14 */ + copy %r1,%r14 + bv %r0(%r25) /* r15 */ + copy %r1,%r15 + bv %r0(%r25) /* r16 */ + copy %r1,%r16 + bv %r0(%r25) /* r17 */ + copy %r1,%r17 + bv %r0(%r25) /* r18 */ + copy %r1,%r18 + bv %r0(%r25) /* r19 */ + copy %r1,%r19 + bv %r0(%r25) /* r20 */ + copy %r1,%r20 + bv %r0(%r25) /* r21 */ + copy %r1,%r21 + bv %r0(%r25) /* r22 */ + copy %r1,%r22 + bv %r0(%r25) /* r23 */ + copy %r1,%r23 + bv %r0(%r25) /* r24 */ + copy %r1,%r24 + bv %r0(%r25) /* r25 */ + copy %r1,%r25 + bv %r0(%r25) /* r26 */ + copy %r1,%r26 + bv %r0(%r25) /* r27 */ + copy %r1,%r27 + bv %r0(%r25) /* r28 */ + copy %r1,%r28 + bv %r0(%r25) /* r29 */ + copy %r1,%r29 + bv %r0(%r25) /* r30 */ + copy %r1,%r30 + bv %r0(%r25) /* r31 */ + copy %r1,%r31 + |