diff options
Diffstat (limited to 'arch/powerpc/kernel/entry_64.S')
| -rw-r--r-- | arch/powerpc/kernel/entry_64.S | 183 |
1 files changed, 81 insertions, 102 deletions
diff --git a/arch/powerpc/kernel/entry_64.S b/arch/powerpc/kernel/entry_64.S index f8a7a1a1a9f4..5971c85df136 100644 --- a/arch/powerpc/kernel/entry_64.S +++ b/arch/powerpc/kernel/entry_64.S @@ -63,15 +63,9 @@ system_call_common: std r0,GPR0(r1) std r10,GPR1(r1) ACCOUNT_CPU_USER_ENTRY(r10, r11) - /* - * This "crclr so" clears CR0.SO, which is the error indication on - * return from this system call. There must be no cmp instruction - * between it and the "mfcr r9" below, otherwise if XER.SO is set, - * CR0.SO will get set, causing all system calls to appear to fail. - */ - crclr so std r2,GPR2(r1) std r3,GPR3(r1) + mfcr r2 std r4,GPR4(r1) std r5,GPR5(r1) std r6,GPR6(r1) @@ -82,18 +76,20 @@ system_call_common: std r11,GPR10(r1) std r11,GPR11(r1) std r11,GPR12(r1) + std r11,_XER(r1) + std r11,_CTR(r1) std r9,GPR13(r1) - mfcr r9 mflr r10 + /* + * This clears CR0.SO (bit 28), which is the error indication on + * return from this system call. + */ + rldimi r2,r11,28,(63-28) li r11,0xc01 - std r9,_CCR(r1) std r10,_LINK(r1) std r11,_TRAP(r1) - mfxer r9 - mfctr r10 - std r9,_XER(r1) - std r10,_CTR(r1) std r3,ORIG_GPR3(r1) + std r2,_CCR(r1) ld r2,PACATOC(r13) addi r9,r1,STACK_FRAME_OVERHEAD ld r11,exception_marker@toc(r2) @@ -154,7 +150,7 @@ END_FW_FTR_SECTION_IFSET(FW_FEATURE_SPLPAR) ld r10,TI_FLAGS(r11) andi. r11,r10,_TIF_SYSCALL_T_OR_A bne- syscall_dotrace -syscall_dotrace_cont: +.Lsyscall_dotrace_cont: cmpldi 0,r0,NR_syscalls bge- syscall_enosys @@ -211,7 +207,7 @@ syscall_exit: cmpld r3,r11 ld r5,_CCR(r1) bge- syscall_error -syscall_error_cont: +.Lsyscall_error_cont: ld r7,_NIP(r1) BEGIN_FTR_SECTION stdcx. r0,0,r1 /* to clear the reservation */ @@ -246,7 +242,7 @@ syscall_error: oris r5,r5,0x1000 /* Set SO bit in CR */ neg r3,r3 std r5,_CCR(r1) - b syscall_error_cont + b .Lsyscall_error_cont /* Traced system call support */ syscall_dotrace: @@ -268,7 +264,7 @@ syscall_dotrace: addi r9,r1,STACK_FRAME_OVERHEAD clrrdi r10,r1,THREAD_SHIFT ld r10,TI_FLAGS(r10) - b syscall_dotrace_cont + b .Lsyscall_dotrace_cont syscall_enosys: li r3,-ENOSYS @@ -562,49 +558,72 @@ _GLOBAL(ret_from_except_lite) mtmsrd r10,1 /* Update machine state */ #endif /* CONFIG_PPC_BOOK3E */ -#ifdef CONFIG_PREEMPT clrrdi r9,r1,THREAD_SHIFT /* current_thread_info() */ - li r0,_TIF_NEED_RESCHED /* bits to check */ ld r3,_MSR(r1) ld r4,TI_FLAGS(r9) - /* Move MSR_PR bit in r3 to _TIF_SIGPENDING position in r0 */ - rlwimi r0,r3,32+TIF_SIGPENDING-MSR_PR_LG,_TIF_SIGPENDING - and. r0,r4,r0 /* check NEED_RESCHED and maybe SIGPENDING */ - bne do_work - -#else /* !CONFIG_PREEMPT */ - ld r3,_MSR(r1) /* Returning to user mode? */ andi. r3,r3,MSR_PR - beq restore /* if not, just restore regs and return */ + beq resume_kernel /* Check current_thread_info()->flags */ + andi. r0,r4,_TIF_USER_WORK_MASK + beq restore + + andi. r0,r4,_TIF_NEED_RESCHED + beq 1f + bl .restore_interrupts + bl .schedule + b .ret_from_except_lite + +1: bl .save_nvgprs + bl .restore_interrupts + addi r3,r1,STACK_FRAME_OVERHEAD + bl .do_notify_resume + b .ret_from_except + +resume_kernel: +#ifdef CONFIG_PREEMPT + /* Check if we need to preempt */ + andi. r0,r4,_TIF_NEED_RESCHED + beq+ restore + /* Check that preempt_count() == 0 and interrupts are enabled */ + lwz r8,TI_PREEMPT(r9) + cmpwi cr1,r8,0 + ld r0,SOFTE(r1) + cmpdi r0,0 + crandc eq,cr1*4+eq,eq + bne restore + + /* + * Here we are preempting the current task. We want to make + * sure we are soft-disabled first + */ + SOFT_DISABLE_INTS(r3,r4) +1: bl .preempt_schedule_irq + + /* Re-test flags and eventually loop */ clrrdi r9,r1,THREAD_SHIFT ld r4,TI_FLAGS(r9) - andi. r0,r4,_TIF_USER_WORK_MASK - bne do_work -#endif /* !CONFIG_PREEMPT */ + andi. r0,r4,_TIF_NEED_RESCHED + bne 1b +#endif /* CONFIG_PREEMPT */ .globl fast_exc_return_irq fast_exc_return_irq: restore: /* - * This is the main kernel exit path, we first check if we - * have to change our interrupt state. + * This is the main kernel exit path. First we check if we + * are about to re-enable interrupts */ ld r5,SOFTE(r1) lbz r6,PACASOFTIRQEN(r13) - cmpwi cr1,r5,0 - cmpw cr0,r5,r6 - beq cr0,4f + cmpwi cr0,r5,0 + beq restore_irq_off - /* We do, handle disable first, which is easy */ - bne cr1,3f; - li r0,0 - stb r0,PACASOFTIRQEN(r13); - TRACE_DISABLE_INTS - b 4f + /* We are enabling, were we already enabled ? Yes, just return */ + cmpwi cr0,r6,1 + beq cr0,do_restore -3: /* + /* * We are about to soft-enable interrupts (we are hard disabled * at this point). We check if there's anything that needs to * be replayed first. @@ -626,7 +645,7 @@ restore_no_replay: /* * Final return path. BookE is handled in a different file */ -4: +do_restore: #ifdef CONFIG_PPC_BOOK3E b .exception_return_book3e #else @@ -700,6 +719,25 @@ fast_exception_return: #endif /* CONFIG_PPC_BOOK3E */ /* + * We are returning to a context with interrupts soft disabled. + * + * However, we may also about to hard enable, so we need to + * make sure that in this case, we also clear PACA_IRQ_HARD_DIS + * or that bit can get out of sync and bad things will happen + */ +restore_irq_off: + ld r3,_MSR(r1) + lbz r7,PACAIRQHAPPENED(r13) + andi. r0,r3,MSR_EE + beq 1f + rlwinm r7,r7,0,~PACA_IRQ_HARD_DIS + stb r7,PACAIRQHAPPENED(r13) +1: li r0,0 + stb r0,PACASOFTIRQEN(r13); + TRACE_DISABLE_INTS + b do_restore + + /* * Something did happen, check if a re-emit is needed * (this also clears paca->irq_happened) */ @@ -748,65 +786,6 @@ restore_check_irq_replay: #endif /* CONFIG_PPC_BOOK3E */ 1: b .ret_from_except /* What else to do here ? */ -do_work: -#ifdef CONFIG_PREEMPT - andi. r0,r3,MSR_PR /* Returning to user mode? */ - bne user_work - /* Check that preempt_count() == 0 and interrupts are enabled */ - lwz r8,TI_PREEMPT(r9) - cmpwi cr1,r8,0 - ld r0,SOFTE(r1) - cmpdi r0,0 - crandc eq,cr1*4+eq,eq - bne restore - - /* - * Here we are preempting the current task. We want to make - * sure we are soft-disabled first - */ - SOFT_DISABLE_INTS(r3,r4) -1: bl .preempt_schedule_irq - - /* Hard-disable interrupts again (and update PACA) */ -#ifdef CONFIG_PPC_BOOK3E - wrteei 0 -#else - ld r10,PACAKMSR(r13) /* Get kernel MSR without EE */ - mtmsrd r10,1 -#endif /* CONFIG_PPC_BOOK3E */ - li r0,PACA_IRQ_HARD_DIS - stb r0,PACAIRQHAPPENED(r13) - - /* Re-test flags and eventually loop */ - clrrdi r9,r1,THREAD_SHIFT - ld r4,TI_FLAGS(r9) - andi. r0,r4,_TIF_NEED_RESCHED - bne 1b - b restore - -user_work: -#endif /* CONFIG_PREEMPT */ - - /* Enable interrupts */ -#ifdef CONFIG_PPC_BOOK3E - wrteei 1 -#else - ori r10,r10,MSR_EE - mtmsrd r10,1 -#endif /* CONFIG_PPC_BOOK3E */ - - andi. r0,r4,_TIF_NEED_RESCHED - beq 1f - bl .restore_interrupts - bl .schedule - b .ret_from_except_lite - -1: bl .save_nvgprs - bl .restore_interrupts - addi r3,r1,STACK_FRAME_OVERHEAD - bl .do_notify_resume - b .ret_from_except - unrecov_restore: addi r3,r1,STACK_FRAME_OVERHEAD bl .unrecoverable_exception |