diff options
Diffstat (limited to 'arch/powerpc/kernel/entry_32.S')
| -rw-r--r-- | arch/powerpc/kernel/entry_32.S | 262 |
1 files changed, 232 insertions, 30 deletions
diff --git a/arch/powerpc/kernel/entry_32.S b/arch/powerpc/kernel/entry_32.S index 4dd38f12915..22b45a4955c 100644 --- a/arch/powerpc/kernel/entry_32.S +++ b/arch/powerpc/kernel/entry_32.S @@ -31,6 +31,7 @@ #include <asm/asm-offsets.h> #include <asm/unistd.h> #include <asm/ftrace.h> +#include <asm/ptrace.h> #undef SHOW_SYSCALLS #undef SHOW_SYSCALLS_TASK @@ -88,7 +89,11 @@ crit_transfer_to_handler: mfspr r0,SPRN_SRR1 stw r0,_SRR1(r11) - mfspr r8,SPRN_SPRG3 + /* set the stack limit to the current stack + * and set the limit to protect the thread_info + * struct + */ + mfspr r8,SPRN_SPRG_THREAD lwz r0,KSP_LIMIT(r8) stw r0,SAVED_KSP_LIMIT(r11) rlwimi r0,r1,0,0,(31-THREAD_SHIFT) @@ -108,7 +113,11 @@ crit_transfer_to_handler: mfspr r0,SPRN_SRR1 stw r0,crit_srr1@l(0) - mfspr r8,SPRN_SPRG3 + /* set the stack limit to the current stack + * and set the limit to protect the thread_info + * struct + */ + mfspr r8,SPRN_SPRG_THREAD lwz r0,KSP_LIMIT(r8) stw r0,saved_ksp_limit@l(0) rlwimi r0,r1,0,0,(31-THREAD_SHIFT) @@ -138,7 +147,7 @@ transfer_to_handler: mfspr r2,SPRN_XER stw r12,_CTR(r11) stw r2,_XER(r11) - mfspr r12,SPRN_SPRG3 + mfspr r12,SPRN_SPRG_THREAD addi r2,r12,-THREAD tovirt(r2,r2) /* set r2 to current */ beq 2f /* if from user, fix up THREAD.regs */ @@ -157,7 +166,7 @@ transfer_to_handler: tophys(r11,r11) addi r11,r11,global_dbcr0@l #ifdef CONFIG_SMP - rlwinm r9,r1,0,0,(31-THREAD_SHIFT) + CURRENT_THREAD_INFO(r9, r1) lwz r9,TI_CPU(r9) slwi r9,r9,3 add r11,r11,r9 @@ -178,7 +187,7 @@ transfer_to_handler: ble- stack_ovf /* then the kernel stack overflowed */ 5: #if defined(CONFIG_6xx) || defined(CONFIG_E500) - rlwinm r9,r1,0,0,31-THREAD_SHIFT + CURRENT_THREAD_INFO(r9, r1) tophys(r9,r9) /* check local flags */ lwz r12,TI_LOCAL_FLAGS(r9) mtcrf 0x01,r12 @@ -191,11 +200,61 @@ transfer_to_handler_cont: mflr r9 lwz r11,0(r9) /* virtual address of handler */ lwz r9,4(r9) /* where to go when done */ +#ifdef CONFIG_TRACE_IRQFLAGS + lis r12,reenable_mmu@h + ori r12,r12,reenable_mmu@l + mtspr SPRN_SRR0,r12 + mtspr SPRN_SRR1,r10 + SYNC + RFI +reenable_mmu: /* re-enable mmu so we can */ + mfmsr r10 + lwz r12,_MSR(r1) + xor r10,r10,r12 + andi. r10,r10,MSR_EE /* Did EE change? */ + beq 1f + + /* + * The trace_hardirqs_off will use CALLER_ADDR0 and CALLER_ADDR1. + * If from user mode there is only one stack frame on the stack, and + * accessing CALLER_ADDR1 will cause oops. So we need create a dummy + * stack frame to make trace_hardirqs_off happy. + * + * This is handy because we also need to save a bunch of GPRs, + * r3 can be different from GPR3(r1) at this point, r9 and r11 + * contains the old MSR and handler address respectively, + * r4 & r5 can contain page fault arguments that need to be passed + * along as well. r12, CCR, CTR, XER etc... are left clobbered as + * they aren't useful past this point (aren't syscall arguments), + * the rest is restored from the exception frame. + */ + stwu r1,-32(r1) + stw r9,8(r1) + stw r11,12(r1) + stw r3,16(r1) + stw r4,20(r1) + stw r5,24(r1) + bl trace_hardirqs_off + lwz r5,24(r1) + lwz r4,20(r1) + lwz r3,16(r1) + lwz r11,12(r1) + lwz r9,8(r1) + addi r1,r1,32 + lwz r0,GPR0(r1) + lwz r6,GPR6(r1) + lwz r7,GPR7(r1) + lwz r8,GPR8(r1) +1: mtctr r11 + mtlr r9 + bctr /* jump to handler */ +#else /* CONFIG_TRACE_IRQFLAGS */ mtspr SPRN_SRR0,r11 mtspr SPRN_SRR1,r10 mtlr r9 SYNC RFI /* jump to handler, enable MMU */ +#endif /* CONFIG_TRACE_IRQFLAGS */ #if defined (CONFIG_6xx) || defined(CONFIG_E500) 4: rlwinm r12,r12,0,~_TLF_NAPPING @@ -251,7 +310,32 @@ _GLOBAL(DoSyscall) #ifdef SHOW_SYSCALLS bl do_show_syscall #endif /* SHOW_SYSCALLS */ - rlwinm r10,r1,0,0,(31-THREAD_SHIFT) /* current_thread_info() */ +#ifdef CONFIG_TRACE_IRQFLAGS + /* Return from syscalls can (and generally will) hard enable + * interrupts. You aren't supposed to call a syscall with + * interrupts disabled in the first place. However, to ensure + * that we get it right vs. lockdep if it happens, we force + * that hard enable here with appropriate tracing if we see + * that we have been called with interrupts off + */ + mfmsr r11 + andi. r12,r11,MSR_EE + bne+ 1f + /* We came in with interrupts disabled, we enable them now */ + bl trace_hardirqs_on + mfmsr r11 + lwz r0,GPR0(r1) + lwz r3,GPR3(r1) + lwz r4,GPR4(r1) + ori r11,r11,MSR_EE + lwz r5,GPR5(r1) + lwz r6,GPR6(r1) + lwz r7,GPR7(r1) + lwz r8,GPR8(r1) + mtmsr r11 +1: +#endif /* CONFIG_TRACE_IRQFLAGS */ + CURRENT_THREAD_INFO(r10, r1) lwz r11,TI_FLAGS(r10) andi. r11,r11,_TIF_SYSCALL_T_OR_A bne- syscall_dotrace @@ -272,9 +356,10 @@ ret_from_syscall: bl do_show_syscall_exit #endif mr r6,r3 - rlwinm r12,r1,0,0,(31-THREAD_SHIFT) /* current_thread_info() */ + CURRENT_THREAD_INFO(r12, r1) /* disable interrupts so current_thread_info()->flags can't change */ LOAD_MSR_KERNEL(r10,MSR_KERNEL) /* doesn't include MSR_EE */ + /* Note: We don't bother telling lockdep about it */ SYNC MTMSRD(r10) lwz r9,TI_FLAGS(r12) @@ -288,6 +373,19 @@ ret_from_syscall: oris r11,r11,0x1000 /* Set SO bit in CR */ stw r11,_CCR(r1) syscall_exit_cont: + lwz r8,_MSR(r1) +#ifdef CONFIG_TRACE_IRQFLAGS + /* If we are going to return from the syscall with interrupts + * off, we trace that here. It shouldn't happen though but we + * want to catch the bugger if it does right ? + */ + andi. r10,r8,MSR_EE + bne+ 1f + stw r3,GPR3(r1) + bl trace_hardirqs_off + lwz r3,GPR3(r1) +1: +#endif /* CONFIG_TRACE_IRQFLAGS */ #if defined(CONFIG_4xx) || defined(CONFIG_BOOKE) /* If the process has its own DBCR0 value, load it up. The internal debug mode bit tells us that dbcr0 should be loaded. */ @@ -296,11 +394,13 @@ syscall_exit_cont: bnel- load_dbcr0 #endif #ifdef CONFIG_44x +BEGIN_MMU_FTR_SECTION lis r4,icache_44x_need_flush@ha lwz r5,icache_44x_need_flush@l(r4) cmplwi cr0,r5,0 bne- 2f 1: +END_MMU_FTR_SECTION_IFCLR(MMU_FTR_TYPE_47x) #endif /* CONFIG_44x */ BEGIN_FTR_SECTION lwarx r7,0,r1 @@ -311,7 +411,6 @@ END_FTR_SECTION_IFSET(CPU_FTR_NEED_PAIRED_STWCX) mtlr r4 mtcr r5 lwz r7,_NIP(r1) - lwz r8,_MSR(r1) FIX_SRR1(r8, r0) lwz r2,GPR2(r1) lwz r1,GPR1(r1) @@ -336,6 +435,17 @@ ret_from_fork: li r3,0 b ret_from_syscall + .globl ret_from_kernel_thread +ret_from_kernel_thread: + REST_NVGPRS(r1) + bl schedule_tail + mtlr r14 + mr r3,r15 + PPC440EP_ERR42 + blrl + li r3,0 + b ret_from_syscall + /* Traced system call support */ syscall_dotrace: SAVE_NVGPRS(r1) @@ -394,7 +504,9 @@ syscall_exit_work: andi. r0,r9,(_TIF_SYSCALL_T_OR_A|_TIF_SINGLESTEP) beq ret_from_except - /* Re-enable interrupts */ + /* Re-enable interrupts. There is no need to trace that with + * lockdep as we are supposed to have IRQs on at this point + */ ori r10,r10,MSR_EE SYNC MTMSRD(r10) @@ -602,7 +714,7 @@ END_FTR_SECTION_IFSET(CPU_FTR_SPE) tophys(r0,r4) CLR_TOP32(r0) - mtspr SPRN_SPRG3,r0 /* Update current THREAD phys addr */ + mtspr SPRN_SPRG_THREAD,r0 /* Update current THREAD phys addr */ lwz r1,KSP(r4) /* Load new stack pointer */ /* save the old current 'last' for return value */ @@ -705,6 +817,7 @@ 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. */ + /* Note: We don't bother telling lockdep about it */ LOAD_MSR_KERNEL(r10,MSR_KERNEL) SYNC /* Some chip revs have problems here... */ MTMSRD(r10) /* disable interrupts */ @@ -715,7 +828,7 @@ ret_from_except: user_exc_return: /* r10 contains MSR_KERNEL here */ /* Check current_thread_info()->flags */ - rlwinm r9,r1,0,0,(31-THREAD_SHIFT) + CURRENT_THREAD_INFO(r9, r1) lwz r9,TI_FLAGS(r9) andi. r0,r9,_TIF_USER_WORK_MASK bne do_work @@ -729,33 +842,84 @@ restore_user: 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, _TIF_EMULATE_STACK_STORE */ + CURRENT_THREAD_INFO(r9, r1) + lwz r8,TI_FLAGS(r9) + andis. r0,r8,_TIF_EMULATE_STACK_STORE@h + beq+ 1f + + addi r8,r1,INT_FRAME_SIZE /* Get the kprobed function entry */ + + lwz r3,GPR1(r1) + subi r3,r3,INT_FRAME_SIZE /* dst: Allocate a trampoline exception frame */ + mr r4,r1 /* src: current exception frame */ + mr r1,r3 /* Reroute the trampoline frame to r1 */ + + /* Copy from the original to the trampoline. */ + li r5,INT_FRAME_SIZE/4 /* size: INT_FRAME_SIZE */ + li r6,0 /* start offset: 0 */ + mtctr r5 +2: lwzx r0,r6,r4 + stwx r0,r6,r3 + addi r6,r6,4 + bdnz 2b + + /* Do real store operation to complete stwu */ + lwz r5,GPR1(r1) + stw r8,0(r5) + + /* Clear _TIF_EMULATE_STACK_STORE flag */ + lis r11,_TIF_EMULATE_STACK_STORE@h + addi r5,r9,TI_FLAGS +0: lwarx r8,0,r5 + andc r8,r8,r11 +#ifdef CONFIG_IBM405_ERR77 + dcbt 0,r5 +#endif + stwcx. r8,0,r5 + bne- 0b +1: + +#ifdef CONFIG_PREEMPT /* check current_thread_info->preempt_count */ - rlwinm r9,r1,0,0,(31-THREAD_SHIFT) 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 + andi. r8,r8,_TIF_NEED_RESCHED beq+ restore + lwz r3,_MSR(r1) andi. r0,r3,MSR_EE /* interrupts off? */ beq restore /* don't schedule if so */ +#ifdef CONFIG_TRACE_IRQFLAGS + /* Lockdep thinks irqs are enabled, we need to call + * preempt_schedule_irq with IRQs off, so we inform lockdep + * now that we -did- turn them off already + */ + bl trace_hardirqs_off +#endif 1: bl preempt_schedule_irq - rlwinm r9,r1,0,0,(31-THREAD_SHIFT) + CURRENT_THREAD_INFO(r9, r1) lwz r3,TI_FLAGS(r9) andi. r0,r3,_TIF_NEED_RESCHED bne- 1b -#else -resume_kernel: +#ifdef CONFIG_TRACE_IRQFLAGS + /* And now, to properly rebalance the above, we tell lockdep they + * are being turned back on, which will happen when we return + */ + bl trace_hardirqs_on +#endif #endif /* CONFIG_PREEMPT */ /* interrupts are hard-disabled at this point */ restore: #ifdef CONFIG_44x +BEGIN_MMU_FTR_SECTION + b 1f +END_MMU_FTR_SECTION_IFSET(MMU_FTR_TYPE_47x) lis r4,icache_44x_need_flush@ha lwz r5,icache_44x_need_flush@l(r4) cmplwi cr0,r5,0 @@ -765,6 +929,39 @@ restore: stw r6,icache_44x_need_flush@l(r4) 1: #endif /* CONFIG_44x */ + + lwz r9,_MSR(r1) +#ifdef CONFIG_TRACE_IRQFLAGS + /* Lockdep doesn't know about the fact that IRQs are temporarily turned + * off in this assembly code while peeking at TI_FLAGS() and such. However + * we need to inform it if the exception turned interrupts off, and we + * are about to trun them back on. + * + * The problem here sadly is that we don't know whether the exceptions was + * one that turned interrupts off or not. So we always tell lockdep about + * turning them on here when we go back to wherever we came from with EE + * on, even if that may meen some redudant calls being tracked. Maybe later + * we could encode what the exception did somewhere or test the exception + * type in the pt_regs but that sounds overkill + */ + andi. r10,r9,MSR_EE + beq 1f + /* + * Since the ftrace irqsoff latency trace checks CALLER_ADDR1, + * which is the stack frame here, we need to force a stack frame + * in case we came from user space. + */ + stwu r1,-32(r1) + mflr r0 + stw r0,4(r1) + stwu r1,-32(r1) + bl trace_hardirqs_on + lwz r1,0(r1) + lwz r1,0(r1) + lwz r9,_MSR(r1) +1: +#endif /* CONFIG_TRACE_IRQFLAGS */ + lwz r0,GPR0(r1) lwz r2,GPR2(r1) REST_4GPRS(3, r1) @@ -782,7 +979,6 @@ 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) */ @@ -805,7 +1001,6 @@ END_FTR_SECTION_IFSET(CPU_FTR_NEED_PAIRED_STWCX) 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 @@ -945,7 +1140,7 @@ exc_exit_restart_end: #ifdef CONFIG_40x .globl ret_from_crit_exc ret_from_crit_exc: - mfspr r9,SPRN_SPRG3 + mfspr r9,SPRN_SPRG_THREAD lis r10,saved_ksp_limit@ha; lwz r10,saved_ksp_limit@l(r10); tovirt(r9,r9); @@ -962,7 +1157,7 @@ ret_from_crit_exc: #ifdef CONFIG_BOOKE .globl ret_from_crit_exc ret_from_crit_exc: - mfspr r9,SPRN_SPRG3 + mfspr r9,SPRN_SPRG_THREAD lwz r10,SAVED_KSP_LIMIT(r1) stw r10,KSP_LIMIT(r9) RESTORE_xSRR(SRR0,SRR1); @@ -971,11 +1166,11 @@ ret_from_crit_exc: .globl ret_from_debug_exc ret_from_debug_exc: - mfspr r9,SPRN_SPRG3 + mfspr r9,SPRN_SPRG_THREAD lwz r10,SAVED_KSP_LIMIT(r1) stw r10,KSP_LIMIT(r9) lwz r9,THREAD_INFO-THREAD(r9) - rlwinm r10,r1,0,0,(31-THREAD_SHIFT) + CURRENT_THREAD_INFO(r10, r1) lwz r10,TI_PREEMPT(r10) stw r10,TI_PREEMPT(r9) RESTORE_xSRR(SRR0,SRR1); @@ -985,7 +1180,7 @@ ret_from_debug_exc: .globl ret_from_mcheck_exc ret_from_mcheck_exc: - mfspr r9,SPRN_SPRG3 + mfspr r9,SPRN_SPRG_THREAD lwz r10,SAVED_KSP_LIMIT(r1) stw r10,KSP_LIMIT(r9) RESTORE_xSRR(SRR0,SRR1); @@ -1009,7 +1204,7 @@ load_dbcr0: lis r11,global_dbcr0@ha addi r11,r11,global_dbcr0@l #ifdef CONFIG_SMP - rlwinm r9,r1,0,0,(31-THREAD_SHIFT) + CURRENT_THREAD_INFO(r9, r1) lwz r9,TI_CPU(r9) slwi r9,r9,3 add r11,r11,r9 @@ -1035,15 +1230,22 @@ do_work: /* r10 contains MSR_KERNEL here */ beq do_user_signal do_resched: /* r10 contains MSR_KERNEL here */ + /* Note: We don't need to inform lockdep that we are enabling + * interrupts here. As far as it knows, they are already enabled + */ ori r10,r10,MSR_EE SYNC MTMSRD(r10) /* hard-enable interrupts */ bl schedule recheck: + /* Note: And we don't tell it we are disabling them again + * neither. Those disable/enable cycles used to peek at + * TI_FLAGS aren't advertised. + */ LOAD_MSR_KERNEL(r10,MSR_KERNEL) SYNC MTMSRD(r10) /* disable interrupts */ - rlwinm r9,r1,0,0,(31-THREAD_SHIFT) + CURRENT_THREAD_INFO(r9, r1) lwz r9,TI_FLAGS(r9) andi. r0,r9,_TIF_NEED_RESCHED bne- do_resched @@ -1062,7 +1264,7 @@ do_user_signal: /* r10 contains MSR_KERNEL here */ stw r3,_TRAP(r1) 2: addi r3,r1,STACK_FRAME_OVERHEAD mr r4,r9 - bl do_signal + bl do_notify_resume REST_NVGPRS(r1) b recheck @@ -1136,7 +1338,7 @@ _GLOBAL(enter_rtas) MTMSRD(r0) /* don't get trashed */ li r9,MSR_KERNEL & ~(MSR_IR|MSR_DR) mtlr r6 - mtspr SPRN_SPRG2,r7 + mtspr SPRN_SPRG_RTAS,r7 mtspr SPRN_SRR0,r8 mtspr SPRN_SRR1,r9 RFI @@ -1146,7 +1348,7 @@ _GLOBAL(enter_rtas) FIX_SRR1(r9,r0) addi r1,r1,INT_FRAME_SIZE li r0,0 - mtspr SPRN_SPRG2,r0 + mtspr SPRN_SPRG_RTAS,r0 mtspr SPRN_SRR0,r8 mtspr SPRN_SRR1,r9 RFI /* return to caller */ |