| /* |
| * 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 */ |
| #ifdef CONFIG_SPE |
| oris r0,r0,MSR_SPE@h /* Disable SPE */ |
| mfspr r12,SPRN_SPEFSCR /* save spefscr register value */ |
| stw r12,THREAD+THREAD_SPEFSCR(r2) |
| #endif /* CONFIG_SPE */ |
| and. r0,r0,r11 /* FP or altivec or SPE 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 */ |
| #ifdef CONFIG_SPE |
| lwz r0,THREAD+THREAD_SPEFSCR(r2) |
| mtspr SPRN_SPEFSCR,r0 /* restore SPEFSCR reg */ |
| #endif /* CONFIG_SPE */ |
| |
| 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 |
