diff options
Diffstat (limited to 'arch/ppc/kernel/entry.S')
| -rw-r--r-- | arch/ppc/kernel/entry.S | 960 |
1 files changed, 0 insertions, 960 deletions
diff --git a/arch/ppc/kernel/entry.S b/arch/ppc/kernel/entry.S deleted file mode 100644 index 5f3a5d0..0000000 --- a/arch/ppc/kernel/entry.S +++ /dev/null @@ -1,960 +0,0 @@ -/* - * PowerPC version - * Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org) - * Rewritten by Cort Dougan (cort@fsmlabs.com) for PReP - * Copyright (C) 1996 Cort Dougan <cort@fsmlabs.com> - * Adapted for Power Macintosh by Paul Mackerras. - * Low-level exception handlers and MMU support - * rewritten by Paul Mackerras. - * Copyright (C) 1996 Paul Mackerras. - * MPC8xx modifications Copyright (C) 1997 Dan Malek (dmalek@jlc.net). - * - * This file contains the system call entry code, context switch - * code, and exception/interrupt return code for PowerPC. - * - * 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. - * - */ - -#include <linux/errno.h> -#include <linux/sys.h> -#include <linux/threads.h> -#include <asm/processor.h> -#include <asm/page.h> -#include <asm/mmu.h> -#include <asm/cputable.h> -#include <asm/thread_info.h> -#include <asm/ppc_asm.h> -#include <asm/asm-offsets.h> -#include <asm/unistd.h> - -#undef SHOW_SYSCALLS -#undef SHOW_SYSCALLS_TASK - -/* - * MSR_KERNEL is > 0x10000 on 4xx/Book-E since it include MSR_CE. - */ -#if MSR_KERNEL >= 0x10000 -#define LOAD_MSR_KERNEL(r, x) lis r,(x)@h; ori r,r,(x)@l -#else -#define LOAD_MSR_KERNEL(r, x) li r,(x) -#endif - -#ifdef CONFIG_BOOKE -#include "head_booke.h" -#define TRANSFER_TO_HANDLER_EXC_LEVEL(exc_level) \ - mtspr exc_level##_SPRG,r8; \ - BOOKE_LOAD_EXC_LEVEL_STACK(exc_level); \ - lwz r0,GPR10-INT_FRAME_SIZE(r8); \ - stw r0,GPR10(r11); \ - lwz r0,GPR11-INT_FRAME_SIZE(r8); \ - stw r0,GPR11(r11); \ - mfspr r8,exc_level##_SPRG - - .globl mcheck_transfer_to_handler -mcheck_transfer_to_handler: - TRANSFER_TO_HANDLER_EXC_LEVEL(MCHECK) - b transfer_to_handler_full - - .globl debug_transfer_to_handler -debug_transfer_to_handler: - TRANSFER_TO_HANDLER_EXC_LEVEL(DEBUG) - b transfer_to_handler_full - - .globl crit_transfer_to_handler -crit_transfer_to_handler: - TRANSFER_TO_HANDLER_EXC_LEVEL(CRIT) - /* fall through */ -#endif - -#ifdef CONFIG_40x - .globl crit_transfer_to_handler -crit_transfer_to_handler: - lwz r0,crit_r10@l(0) - stw r0,GPR10(r11) - lwz r0,crit_r11@l(0) - stw r0,GPR11(r11) - /* fall through */ -#endif - -/* - * This code finishes saving the registers to the exception frame - * and jumps to the appropriate handler for the exception, turning - * on address translation. - * Note that we rely on the caller having set cr0.eq iff the exception - * occurred in kernel mode (i.e. MSR:PR = 0). - */ - .globl transfer_to_handler_full -transfer_to_handler_full: - SAVE_NVGPRS(r11) - /* fall through */ - - .globl transfer_to_handler -transfer_to_handler: - stw r2,GPR2(r11) - stw r12,_NIP(r11) - stw r9,_MSR(r11) - andi. r2,r9,MSR_PR - mfctr r12 - mfspr r2,SPRN_XER - stw r12,_CTR(r11) - stw r2,_XER(r11) - mfspr r12,SPRN_SPRG3 - addi r2,r12,-THREAD - tovirt(r2,r2) /* set r2 to current */ - beq 2f /* if from user, fix up THREAD.regs */ - addi r11,r1,STACK_FRAME_OVERHEAD - stw r11,PT_REGS(r12) -#if defined(CONFIG_40x) || defined(CONFIG_BOOKE) - /* Check to see if the dbcr0 register is set up to debug. Use the - single-step bit to do this. */ - lwz r12,THREAD_DBCR0(r12) - andis. r12,r12,DBCR0_IC@h - beq+ 3f - /* From user and task is ptraced - load up global dbcr0 */ - li r12,-1 /* clear all pending debug events */ - mtspr SPRN_DBSR,r12 - lis r11,global_dbcr0@ha - tophys(r11,r11) - addi r11,r11,global_dbcr0@l - lwz r12,0(r11) - mtspr SPRN_DBCR0,r12 - lwz r12,4(r11) - addi r12,r12,-1 - stw r12,4(r11) -#endif - b 3f - -2: /* if from kernel, check interrupted DOZE/NAP mode and - * check for stack overflow - */ - lwz r9,THREAD_INFO-THREAD(r12) - cmplw r1,r9 /* if r1 <= current->thread_info */ - ble- stack_ovf /* then the kernel stack overflowed */ -5: -#ifdef CONFIG_6xx - tophys(r9,r9) /* check local flags */ - lwz r12,TI_LOCAL_FLAGS(r9) - mtcrf 0x01,r12 - bt- 31-TLF_NAPPING,4f -#endif /* CONFIG_6xx */ - .globl transfer_to_handler_cont -transfer_to_handler_cont: -3: - mflr r9 - lwz r11,0(r9) /* virtual address of handler */ - lwz r9,4(r9) /* where to go when done */ - mtspr SPRN_SRR0,r11 - mtspr SPRN_SRR1,r10 - mtlr r9 - SYNC - RFI /* jump to handler, enable MMU */ - -#ifdef CONFIG_6xx -4: rlwinm r12,r12,0,~_TLF_NAPPING - stw r12,TI_LOCAL_FLAGS(r9) - b power_save_6xx_restore -#endif - -/* - * On kernel stack overflow, load up an initial stack pointer - * and call StackOverflow(regs), which should not return. - */ -stack_ovf: - /* sometimes we use a statically-allocated stack, which is OK. */ - lis r12,_end@h - ori r12,r12,_end@l - cmplw r1,r12 - ble 5b /* r1 <= &_end is OK */ - SAVE_NVGPRS(r11) - addi r3,r1,STACK_FRAME_OVERHEAD - lis r1,init_thread_union@ha - addi r1,r1,init_thread_union@l - addi r1,r1,THREAD_SIZE-STACK_FRAME_OVERHEAD - lis r9,StackOverflow@ha - addi r9,r9,StackOverflow@l - LOAD_MSR_KERNEL(r10,MSR_KERNEL) - FIX_SRR1(r10,r12) - mtspr SPRN_SRR0,r9 - mtspr SPRN_SRR1,r10 - SYNC - RFI - -/* - * Handle a system call. - */ - .stabs "arch/ppc/kernel/",N_SO,0,0,0f - .stabs "entry.S",N_SO,0,0,0f -0: - -_GLOBAL(DoSyscall) - stw r3,ORIG_GPR3(r1) - li r12,0 - stw r12,RESULT(r1) - lwz r11,_CCR(r1) /* Clear SO bit in CR */ - rlwinm r11,r11,0,4,2 - stw r11,_CCR(r1) -#ifdef SHOW_SYSCALLS - bl do_show_syscall -#endif /* SHOW_SYSCALLS */ - rlwinm r10,r1,0,0,18 /* current_thread_info() */ - lwz r11,TI_FLAGS(r10) - andi. r11,r11,_TIF_SYSCALL_T_OR_A - bne- syscall_dotrace -syscall_dotrace_cont: - cmplwi 0,r0,NR_syscalls - lis r10,sys_call_table@h - ori r10,r10,sys_call_table@l - slwi r0,r0,2 - bge- 66f - lwzx r10,r10,r0 /* Fetch system call handler [ptr] */ - mtlr r10 - addi r9,r1,STACK_FRAME_OVERHEAD - PPC440EP_ERR42 - blrl /* Call handler */ - .globl ret_from_syscall -ret_from_syscall: -#ifdef SHOW_SYSCALLS - bl do_show_syscall_exit -#endif - mr r6,r3 - rlwinm r12,r1,0,0,18 /* current_thread_info() */ - /* disable interrupts so current_thread_info()->flags can't change */ - LOAD_MSR_KERNEL(r10,MSR_KERNEL) /* doesn't include MSR_EE */ - SYNC - MTMSRD(r10) - lwz r9,TI_FLAGS(r12) - li r8,-_LAST_ERRNO - andi. r0,r9,(_TIF_SYSCALL_T_OR_A|_TIF_SINGLESTEP|_TIF_USER_WORK_MASK|_TIF_PERSYSCALL_MASK) - bne- syscall_exit_work - cmplw 0,r3,r8 - blt+ syscall_exit_cont - lwz r11,_CCR(r1) /* Load CR */ - neg r3,r3 - oris r11,r11,0x1000 /* Set SO bit in CR */ - stw r11,_CCR(r1) -syscall_exit_cont: -#if defined(CONFIG_4xx) || defined(CONFIG_BOOKE) - /* If the process has its own DBCR0 value, load it up. The single - step bit tells us that dbcr0 should be loaded. */ - lwz r0,THREAD+THREAD_DBCR0(r2) - andis. r10,r0,DBCR0_IC@h - bnel- load_dbcr0 -#endif -#ifdef CONFIG_44x - lis r4,icache_44x_need_flush@ha - lwz r5,icache_44x_need_flush@l(r4) - cmplwi cr0,r5,0 - bne- 2f -1: -#endif /* CONFIG_44x */ -BEGIN_FTR_SECTION - lwarx r7,0,r1 -END_FTR_SECTION_IFSET(CPU_FTR_NEED_PAIRED_STWCX) - stwcx. r0,0,r1 /* to clear the reservation */ - lwz r4,_LINK(r1) - lwz r5,_CCR(r1) - mtlr r4 - mtcr r5 - lwz r7,_NIP(r1) - lwz r8,_MSR(r1) - FIX_SRR1(r8, r0) - lwz r2,GPR2(r1) - lwz r1,GPR1(r1) - mtspr SPRN_SRR0,r7 - mtspr SPRN_SRR1,r8 - SYNC - RFI -#ifdef CONFIG_44x -2: li r7,0 - iccci r0,r0 - stw r7,icache_44x_need_flush@l(r4) - b 1b -#endif /* CONFIG_44x */ - -66: li r3,-ENOSYS - b ret_from_syscall - - .globl ret_from_fork -ret_from_fork: - REST_NVGPRS(r1) - bl schedule_tail - li r3,0 - b ret_from_syscall - -/* Traced system call support */ -syscall_dotrace: - SAVE_NVGPRS(r1) - li r0,0xc00 - stw r0,TRAP(r1) - addi r3,r1,STACK_FRAME_OVERHEAD - bl do_syscall_trace_enter - lwz r0,GPR0(r1) /* Restore original registers */ - lwz r3,GPR3(r1) - lwz r4,GPR4(r1) - lwz r5,GPR5(r1) - lwz r6,GPR6(r1) - lwz r7,GPR7(r1) - lwz r8,GPR8(r1) - REST_NVGPRS(r1) - b syscall_dotrace_cont - -syscall_exit_work: - andi. r0,r9,_TIF_RESTOREALL - beq+ 0f - REST_NVGPRS(r1) - b 2f -0: cmplw 0,r3,r8 - blt+ 1f - andi. r0,r9,_TIF_NOERROR - bne- 1f - lwz r11,_CCR(r1) /* Load CR */ - neg r3,r3 - oris r11,r11,0x1000 /* Set SO bit in CR */ - stw r11,_CCR(r1) - -1: stw r6,RESULT(r1) /* Save result */ - stw r3,GPR3(r1) /* Update return value */ -2: andi. r0,r9,(_TIF_PERSYSCALL_MASK) - beq 4f - - /* Clear per-syscall TIF flags if any are set. */ - - li r11,_TIF_PERSYSCALL_MASK - addi r12,r12,TI_FLAGS -3: lwarx r8,0,r12 - andc r8,r8,r11 -#ifdef CONFIG_IBM405_ERR77 - dcbt 0,r12 -#endif - stwcx. r8,0,r12 - bne- 3b - subi r12,r12,TI_FLAGS - -4: /* Anything which requires enabling interrupts? */ - andi. r0,r9,(_TIF_SYSCALL_T_OR_A|_TIF_SINGLESTEP) - beq ret_from_except - - /* Re-enable interrupts */ - ori r10,r10,MSR_EE - SYNC - MTMSRD(r10) - - /* Save NVGPRS if they're not saved already */ - lwz r4,TRAP(r1) - andi. r4,r4,1 - beq 5f - SAVE_NVGPRS(r1) - li r4,0xc00 - stw r4,TRAP(r1) -5: - addi r3,r1,STACK_FRAME_OVERHEAD - bl do_syscall_trace_leave - b ret_from_except_full - -#ifdef SHOW_SYSCALLS -do_show_syscall: -#ifdef SHOW_SYSCALLS_TASK - lis r11,show_syscalls_task@ha - lwz r11,show_syscalls_task@l(r11) - cmp 0,r2,r11 - bnelr -#endif - stw r31,GPR31(r1) - mflr r31 - lis r3,7f@ha - addi r3,r3,7f@l - lwz r4,GPR0(r1) - lwz r5,GPR3(r1) - lwz r6,GPR4(r1) - lwz r7,GPR5(r1) - lwz r8,GPR6(r1) - lwz r9,GPR7(r1) - bl printk - lis r3,77f@ha - addi r3,r3,77f@l - lwz r4,GPR8(r1) - mr r5,r2 - bl printk - lwz r0,GPR0(r1) - lwz r3,GPR3(r1) - lwz r4,GPR4(r1) - lwz r5,GPR5(r1) - lwz r6,GPR6(r1) - lwz r7,GPR7(r1) - lwz r8,GPR8(r1) - mtlr r31 - lwz r31,GPR31(r1) - blr - -do_show_syscall_exit: -#ifdef SHOW_SYSCALLS_TASK - lis r11,show_syscalls_task@ha - lwz r11,show_syscalls_task@l(r11) - cmp 0,r2,r11 - bnelr -#endif - stw r31,GPR31(r1) - mflr r31 - stw r3,RESULT(r1) /* Save result */ - mr r4,r3 - lis r3,79f@ha - addi r3,r3,79f@l - bl printk - lwz r3,RESULT(r1) - mtlr r31 - lwz r31,GPR31(r1) - blr - -7: .string "syscall %d(%x, %x, %x, %x, %x, " -77: .string "%x), current=%p\n" -79: .string " -> %x\n" - .align 2,0 - -#ifdef SHOW_SYSCALLS_TASK - .data - .globl show_syscalls_task -show_syscalls_task: - .long -1 - .text -#endif -#endif /* SHOW_SYSCALLS */ - -/* - * The fork/clone functions need to copy the full register set into - * the child process. Therefore we need to save all the nonvolatile - * registers (r13 - r31) before calling the C code. - */ - .globl ppc_fork -ppc_fork: - SAVE_NVGPRS(r1) - lwz r0,TRAP(r1) - rlwinm r0,r0,0,0,30 /* clear LSB to indicate full */ - stw r0,TRAP(r1) /* register set saved */ - b sys_fork - - .globl ppc_vfork -ppc_vfork: - SAVE_NVGPRS(r1) - lwz r0,TRAP(r1) - rlwinm r0,r0,0,0,30 /* clear LSB to indicate full */ - stw r0,TRAP(r1) /* register set saved */ - b sys_vfork - - .globl ppc_clone -ppc_clone: - SAVE_NVGPRS(r1) - lwz r0,TRAP(r1) - rlwinm r0,r0,0,0,30 /* clear LSB to indicate full */ - stw r0,TRAP(r1) /* register set saved */ - b sys_clone - - .globl ppc_swapcontext -ppc_swapcontext: - SAVE_NVGPRS(r1) - lwz r0,TRAP(r1) - rlwinm r0,r0,0,0,30 /* clear LSB to indicate full */ - stw r0,TRAP(r1) /* register set saved */ - b sys_swapcontext - -/* - * Top-level page fault handling. - * This is in assembler because if do_page_fault tells us that - * it is a bad kernel page fault, we want to save the non-volatile - * registers before calling bad_page_fault. - */ - .globl handle_page_fault -handle_page_fault: - stw r4,_DAR(r1) - addi r3,r1,STACK_FRAME_OVERHEAD - bl do_page_fault - cmpwi r3,0 - beq+ ret_from_except - SAVE_NVGPRS(r1) - lwz r0,TRAP(r1) - clrrwi r0,r0,1 - stw r0,TRAP(r1) - mr r5,r3 - addi r3,r1,STACK_FRAME_OVERHEAD - lwz r4,_DAR(r1) - bl bad_page_fault - b ret_from_except_full - -/* - * This routine switches between two different tasks. The process - * state of one is saved on its kernel stack. Then the state - * of the other is restored from its kernel stack. The memory - * management hardware is updated to the second process's state. - * Finally, we can return to the second process. - * On entry, r3 points to the THREAD for the current task, r4 - * points to the THREAD for the new task. - * - * This routine is always called with interrupts disabled. - * - * Note: there are two ways to get to the "going out" portion - * of this code; either by coming in via the entry (_switch) - * or via "fork" which must set up an environment equivalent - * to the "_switch" path. If you change this , you'll have to - * change the fork code also. - * - * The code which creates the new task context is in 'copy_thread' - * in arch/ppc/kernel/process.c - */ -_GLOBAL(_switch) - stwu r1,-INT_FRAME_SIZE(r1) - mflr r0 - stw r0,INT_FRAME_SIZE+4(r1) - /* r3-r12 are caller saved -- Cort */ - SAVE_NVGPRS(r1) - stw r0,_NIP(r1) /* Return to switch caller */ - mfmsr r11 - li r0,MSR_FP /* Disable floating-point */ -#ifdef CONFIG_ALTIVEC -BEGIN_FTR_SECTION - oris r0,r0,MSR_VEC@h /* Disable altivec */ - mfspr r12,SPRN_VRSAVE /* save vrsave register value */ - stw r12,THREAD+THREAD_VRSAVE(r2) -END_FTR_SECTION_IFSET(CPU_FTR_ALTIVEC) -#endif /* CONFIG_ALTIVEC */ - and. r0,r0,r11 /* FP or altivec enabled? */ - beq+ 1f - andc r11,r11,r0 - MTMSRD(r11) - isync -1: stw r11,_MSR(r1) - mfcr r10 - stw r10,_CCR(r1) - stw r1,KSP(r3) /* Set old stack pointer */ - -#ifdef CONFIG_SMP - /* We need a sync somewhere here to make sure that if the - * previous task gets rescheduled on another CPU, it sees all - * stores it has performed on this one. - */ - sync -#endif /* CONFIG_SMP */ - - tophys(r0,r4) - CLR_TOP32(r0) - mtspr SPRN_SPRG3,r0 /* Update current THREAD phys addr */ - lwz r1,KSP(r4) /* Load new stack pointer */ - - /* save the old current 'last' for return value */ - mr r3,r2 - addi r2,r4,-THREAD /* Update current */ - -#ifdef CONFIG_ALTIVEC -BEGIN_FTR_SECTION - lwz r0,THREAD+THREAD_VRSAVE(r2) - mtspr SPRN_VRSAVE,r0 /* if G4, restore VRSAVE reg */ -END_FTR_SECTION_IFSET(CPU_FTR_ALTIVEC) -#endif /* CONFIG_ALTIVEC */ - lwz r0,_CCR(r1) - mtcrf 0xFF,r0 - /* r3-r12 are destroyed -- Cort */ - REST_NVGPRS(r1) - - lwz r4,_NIP(r1) /* Return to _switch caller in new task */ - mtlr r4 - addi r1,r1,INT_FRAME_SIZE - blr - - .globl fast_exception_return -fast_exception_return: -#if !(defined(CONFIG_4xx) || defined(CONFIG_BOOKE)) - andi. r10,r9,MSR_RI /* check for recoverable interrupt */ - beq 1f /* if not, we've got problems */ -#endif - -2: REST_4GPRS(3, r11) - lwz r10,_CCR(r11) - REST_GPR(1, r11) - mtcr r10 - lwz r10,_LINK(r11) - mtlr r10 - REST_GPR(10, r11) - mtspr SPRN_SRR1,r9 - mtspr SPRN_SRR0,r12 - REST_GPR(9, r11) - REST_GPR(12, r11) - lwz r11,GPR11(r11) - SYNC - RFI - -#if !(defined(CONFIG_4xx) || defined(CONFIG_BOOKE)) -/* check if the exception happened in a restartable section */ -1: lis r3,exc_exit_restart_end@ha - addi r3,r3,exc_exit_restart_end@l - cmplw r12,r3 - bge 3f - lis r4,exc_exit_restart@ha - addi r4,r4,exc_exit_restart@l - cmplw r12,r4 - blt 3f - lis r3,fee_restarts@ha - tophys(r3,r3) - lwz r5,fee_restarts@l(r3) - addi r5,r5,1 - stw r5,fee_restarts@l(r3) - mr r12,r4 /* restart at exc_exit_restart */ - b 2b - - .section .bss - .align 2 -fee_restarts: - .space 4 - .previous - -/* aargh, a nonrecoverable interrupt, panic */ -/* aargh, we don't know which trap this is */ -/* but the 601 doesn't implement the RI bit, so assume it's OK */ -3: -BEGIN_FTR_SECTION - b 2b -END_FTR_SECTION_IFSET(CPU_FTR_601) - li r10,-1 - stw r10,TRAP(r11) - addi r3,r1,STACK_FRAME_OVERHEAD - lis r10,MSR_KERNEL@h - ori r10,r10,MSR_KERNEL@l - bl transfer_to_handler_full - .long nonrecoverable_exception - .long ret_from_except -#endif - - .globl ret_from_except_full -ret_from_except_full: - REST_NVGPRS(r1) - /* fall through */ - - .globl ret_from_except -ret_from_except: - /* Hard-disable interrupts so that current_thread_info()->flags - * can't change between when we test it and when we return - * from the interrupt. */ - LOAD_MSR_KERNEL(r10,MSR_KERNEL) - SYNC /* Some chip revs have problems here... */ - MTMSRD(r10) /* disable interrupts */ - - lwz r3,_MSR(r1) /* Returning to user mode? */ - andi. r0,r3,MSR_PR - beq resume_kernel - -user_exc_return: /* r10 contains MSR_KERNEL here */ - /* Check current_thread_info()->flags */ - rlwinm r9,r1,0,0,18 - lwz r9,TI_FLAGS(r9) - andi. r0,r9,(_TIF_SIGPENDING|_TIF_RESTORE_SIGMASK|_TIF_NEED_RESCHED) - bne do_work - -restore_user: -#if defined(CONFIG_4xx) || defined(CONFIG_BOOKE) - /* Check whether this process has its own DBCR0 value. The single - step bit tells us that dbcr0 should be loaded. */ - lwz r0,THREAD+THREAD_DBCR0(r2) - andis. r10,r0,DBCR0_IC@h - bnel- load_dbcr0 -#endif - -#ifdef CONFIG_PREEMPT - b restore - -/* N.B. the only way to get here is from the beq following ret_from_except. */ -resume_kernel: - /* check current_thread_info->preempt_count */ - rlwinm r9,r1,0,0,18 - lwz r0,TI_PREEMPT(r9) - cmpwi 0,r0,0 /* if non-zero, just restore regs and return */ - bne restore - lwz r0,TI_FLAGS(r9) - andi. r0,r0,_TIF_NEED_RESCHED - beq+ restore - andi. r0,r3,MSR_EE /* interrupts off? */ - beq restore /* don't schedule if so */ -1: bl preempt_schedule_irq - rlwinm r9,r1,0,0,18 - lwz r3,TI_FLAGS(r9) - andi. r0,r3,_TIF_NEED_RESCHED - bne- 1b -#else -resume_kernel: -#endif /* CONFIG_PREEMPT */ - - /* interrupts are hard-disabled at this point */ -restore: -#ifdef CONFIG_44x - lis r4,icache_44x_need_flush@ha - lwz r5,icache_44x_need_flush@l(r4) - cmplwi cr0,r5,0 - beq+ 1f - li r6,0 - iccci r0,r0 - stw r6,icache_44x_need_flush@l(r4) -1: -#endif /* CONFIG_44x */ - lwz r0,GPR0(r1) - lwz r2,GPR2(r1) - REST_4GPRS(3, r1) - REST_2GPRS(7, r1) - - lwz r10,_XER(r1) - lwz r11,_CTR(r1) - mtspr SPRN_XER,r10 - mtctr r11 - - PPC405_ERR77(0,r1) -BEGIN_FTR_SECTION - lwarx r11,0,r1 -END_FTR_SECTION_IFSET(CPU_FTR_NEED_PAIRED_STWCX) - stwcx. r0,0,r1 /* to clear the reservation */ - -#if !(defined(CONFIG_4xx) || defined(CONFIG_BOOKE)) - lwz r9,_MSR(r1) - andi. r10,r9,MSR_RI /* check if this exception occurred */ - beql nonrecoverable /* at a bad place (MSR:RI = 0) */ - - lwz r10,_CCR(r1) - lwz r11,_LINK(r1) - mtcrf 0xFF,r10 - mtlr r11 - - /* - * Once we put values in SRR0 and SRR1, we are in a state - * where exceptions are not recoverable, since taking an - * exception will trash SRR0 and SRR1. Therefore we clear the - * MSR:RI bit to indicate this. If we do take an exception, - * we can't return to the point of the exception but we - * can restart the exception exit path at the label - * exc_exit_restart below. -- paulus - */ - LOAD_MSR_KERNEL(r10,MSR_KERNEL & ~MSR_RI) - SYNC - MTMSRD(r10) /* clear the RI bit */ - .globl exc_exit_restart -exc_exit_restart: - lwz r9,_MSR(r1) - lwz r12,_NIP(r1) - FIX_SRR1(r9,r10) - mtspr SPRN_SRR0,r12 - mtspr SPRN_SRR1,r9 - REST_4GPRS(9, r1) - lwz r1,GPR1(r1) - .globl exc_exit_restart_end -exc_exit_restart_end: - SYNC - RFI - -#else /* !(CONFIG_4xx || CONFIG_BOOKE) */ - /* - * This is a bit different on 4xx/Book-E because it doesn't have - * the RI bit in the MSR. - * The TLB miss handler checks if we have interrupted - * the exception exit path and restarts it if so - * (well maybe one day it will... :). - */ - lwz r11,_LINK(r1) - mtlr r11 - lwz r10,_CCR(r1) - mtcrf 0xff,r10 - REST_2GPRS(9, r1) - .globl exc_exit_restart -exc_exit_restart: - lwz r11,_NIP(r1) - lwz r12,_MSR(r1) -exc_exit_start: - mtspr SPRN_SRR0,r11 - mtspr SPRN_SRR1,r12 - REST_2GPRS(11, r1) - lwz r1,GPR1(r1) - .globl exc_exit_restart_end -exc_exit_restart_end: - PPC405_ERR77_SYNC - rfi - b . /* prevent prefetch past rfi */ - -/* - * Returning from a critical interrupt in user mode doesn't need - * to be any different from a normal exception. For a critical - * interrupt in the kernel, we just return (without checking for - * preemption) since the interrupt may have happened at some crucial - * place (e.g. inside the TLB miss handler), and because we will be - * running with r1 pointing into critical_stack, not the current - * process's kernel stack (and therefore current_thread_info() will - * give the wrong answer). - * We have to restore various SPRs that may have been in use at the - * time of the critical interrupt. - * - */ -#ifdef CONFIG_40x -#define PPC_40x_TURN_OFF_MSR_DR \ - /* avoid any possible TLB misses here by turning off MSR.DR, we \ - * assume the instructions here are mapped by a pinned TLB entry */ \ - li r10,MSR_IR; \ - mtmsr r10; \ - isync; \ - tophys(r1, r1); -#else -#define PPC_40x_TURN_OFF_MSR_DR -#endif - -#define RET_FROM_EXC_LEVEL(exc_lvl_srr0, exc_lvl_srr1, exc_lvl_rfi) \ - REST_NVGPRS(r1); \ - lwz r3,_MSR(r1); \ - andi. r3,r3,MSR_PR; \ - LOAD_MSR_KERNEL(r10,MSR_KERNEL); \ - bne user_exc_return; \ - lwz r0,GPR0(r1); \ - lwz r2,GPR2(r1); \ - REST_4GPRS(3, r1); \ - REST_2GPRS(7, r1); \ - lwz r10,_XER(r1); \ - lwz r11,_CTR(r1); \ - mtspr SPRN_XER,r10; \ - mtctr r11; \ - PPC405_ERR77(0,r1); \ - stwcx. r0,0,r1; /* to clear the reservation */ \ - lwz r11,_LINK(r1); \ - mtlr r11; \ - lwz r10,_CCR(r1); \ - mtcrf 0xff,r10; \ - PPC_40x_TURN_OFF_MSR_DR; \ - lwz r9,_DEAR(r1); \ - lwz r10,_ESR(r1); \ - mtspr SPRN_DEAR,r9; \ - mtspr SPRN_ESR,r10; \ - lwz r11,_NIP(r1); \ - lwz r12,_MSR(r1); \ - mtspr exc_lvl_srr0,r11; \ - mtspr exc_lvl_srr1,r12; \ - lwz r9,GPR9(r1); \ - lwz r12,GPR12(r1); \ - lwz r10,GPR10(r1); \ - lwz r11,GPR11(r1); \ - lwz r1,GPR1(r1); \ - PPC405_ERR77_SYNC; \ - exc_lvl_rfi; \ - b .; /* prevent prefetch past exc_lvl_rfi */ - - .globl ret_from_crit_exc -ret_from_crit_exc: - RET_FROM_EXC_LEVEL(SPRN_CSRR0, SPRN_CSRR1, RFCI) - -#ifdef CONFIG_BOOKE - .globl ret_from_debug_exc -ret_from_debug_exc: - RET_FROM_EXC_LEVEL(SPRN_DSRR0, SPRN_DSRR1, RFDI) - - .globl ret_from_mcheck_exc -ret_from_mcheck_exc: - RET_FROM_EXC_LEVEL(SPRN_MCSRR0, SPRN_MCSRR1, RFMCI) -#endif /* CONFIG_BOOKE */ - -/* - * Load the DBCR0 value for a task that is being ptraced, - * having first saved away the global DBCR0. Note that r0 - * has the dbcr0 value to set upon entry to this. - */ -load_dbcr0: - mfmsr r10 /* first disable debug exceptions */ - rlwinm r10,r10,0,~MSR_DE - mtmsr r10 - isync - mfspr r10,SPRN_DBCR0 - lis r11,global_dbcr0@ha - addi r11,r11,global_dbcr0@l - stw r10,0(r11) - mtspr SPRN_DBCR0,r0 - lwz r10,4(r11) - addi r10,r10,1 - stw r10,4(r11) - li r11,-1 - mtspr SPRN_DBSR,r11 /* clear all pending debug events */ - blr - - .section .bss - .align 4 -global_dbcr0: - .space 8 - .previous -#endif /* !(CONFIG_4xx || CONFIG_BOOKE) */ - -do_work: /* r10 contains MSR_KERNEL here */ - andi. r0,r9,_TIF_NEED_RESCHED - beq do_user_signal - -do_resched: /* r10 contains MSR_KERNEL here */ - ori r10,r10,MSR_EE - SYNC - MTMSRD(r10) /* hard-enable interrupts */ - bl schedule -recheck: - LOAD_MSR_KERNEL(r10,MSR_KERNEL) - SYNC - MTMSRD(r10) /* disable interrupts */ - rlwinm r9,r1,0,0,18 - lwz r9,TI_FLAGS(r9) - andi. r0,r9,_TIF_NEED_RESCHED - bne- do_resched - andi. r0,r9,_TIF_SIGPENDING - beq restore_user -do_user_signal: /* r10 contains MSR_KERNEL here */ - ori r10,r10,MSR_EE - SYNC - MTMSRD(r10) /* hard-enable interrupts */ - /* save r13-r31 in the exception frame, if not already done */ - lwz r3,TRAP(r1) - andi. r0,r3,1 - beq 2f - SAVE_NVGPRS(r1) - rlwinm r3,r3,0,0,30 - stw r3,TRAP(r1) -2: li r3,0 - addi r4,r1,STACK_FRAME_OVERHEAD - bl do_signal - REST_NVGPRS(r1) - b recheck - -/* - * We come here when we are at the end of handling an exception - * that occurred at a place where taking an exception will lose - * state information, such as the contents of SRR0 and SRR1. - */ -nonrecoverable: - lis r10,exc_exit_restart_end@ha - addi r10,r10,exc_exit_restart_end@l - cmplw r12,r10 - bge 3f - lis r11,exc_exit_restart@ha - addi r11,r11,exc_exit_restart@l - cmplw r12,r11 - blt 3f - lis r10,ee_restarts@ha - lwz r12,ee_restarts@l(r10) - addi r12,r12,1 - stw r12,ee_restarts@l(r10) - mr r12,r11 /* restart at exc_exit_restart */ - blr -3: /* OK, we can't recover, kill this process */ - /* but the 601 doesn't implement the RI bit, so assume it's OK */ -BEGIN_FTR_SECTION - blr -END_FTR_SECTION_IFSET(CPU_FTR_601) - lwz r3,TRAP(r1) - andi. r0,r3,1 - beq 4f - SAVE_NVGPRS(r1) - rlwinm r3,r3,0,0,30 - stw r3,TRAP(r1) -4: addi r3,r1,STACK_FRAME_OVERHEAD - bl nonrecoverable_exception - /* shouldn't return */ - b 4b - - .section .bss - .align 2 -ee_restarts: - .space 4 - .previous |
