diff options
Diffstat (limited to 'arch/powerpc/kernel/entry_64.S')
| -rw-r--r-- | arch/powerpc/kernel/entry_64.S | 897 |
1 files changed, 187 insertions, 710 deletions
diff --git a/arch/powerpc/kernel/entry_64.S b/arch/powerpc/kernel/entry_64.S index 6ba675b0cf7d..9a1e5d636dea 100644 --- a/arch/powerpc/kernel/entry_64.S +++ b/arch/powerpc/kernel/entry_64.S @@ -16,6 +16,7 @@ #include <linux/errno.h> #include <linux/err.h> +#include <asm/cache.h> #include <asm/unistd.h> #include <asm/processor.h> #include <asm/page.h> @@ -51,8 +52,10 @@ SYS_CALL_TABLE: .tc sys_call_table[TC],sys_call_table +#ifdef CONFIG_COMPAT COMPAT_SYS_CALL_TABLE: .tc compat_sys_call_table[TC],compat_sys_call_table +#endif /* This value is used to mark exception frames on the stack. */ exception_marker: @@ -69,6 +72,7 @@ BEGIN_FTR_SECTION bne .Ltabort_syscall END_FTR_SECTION_IFSET(CPU_FTR_TM) #endif +_ASM_NOKPROBE_SYMBOL(system_call_common) mr r10,r1 ld r1,PACAKSAVE(r13) std r10,0(r1) @@ -76,342 +80,122 @@ END_FTR_SECTION_IFSET(CPU_FTR_TM) std r12,_MSR(r1) std r0,GPR0(r1) std r10,GPR1(r1) + std r2,GPR2(r1) #ifdef CONFIG_PPC_FSL_BOOK3E START_BTB_FLUSH_SECTION BTB_FLUSH(r10) END_BTB_FLUSH_SECTION #endif - ACCOUNT_CPU_USER_ENTRY(r13, r10, r11) - std r2,GPR2(r1) + ld r2,PACATOC(r13) + mfcr r12 + li r11,0 + /* Can we avoid saving r3-r8 in common case? */ std r3,GPR3(r1) - mfcr r2 std r4,GPR4(r1) std r5,GPR5(r1) std r6,GPR6(r1) std r7,GPR7(r1) std r8,GPR8(r1) - li r11,0 + /* Zero r9-r12, this should only be required when restoring all GPRs */ std r11,GPR9(r1) std r11,GPR10(r1) std r11,GPR11(r1) std r11,GPR12(r1) + std r9,GPR13(r1) + SAVE_NVGPRS(r1) std r11,_XER(r1) std r11,_CTR(r1) - std r9,GPR13(r1) 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 + rldimi r12,r11,28,(63-28) + li r11,0xc00 std r10,_LINK(r1) std r11,_TRAP(r1) + std r12,_CCR(r1) std r3,ORIG_GPR3(r1) - std r2,_CCR(r1) - ld r2,PACATOC(r13) - addi r9,r1,STACK_FRAME_OVERHEAD + addi r10,r1,STACK_FRAME_OVERHEAD ld r11,exception_marker@toc(r2) - std r11,-16(r9) /* "regshere" marker */ - - kuap_check_amr r10, r11 - -#if defined(CONFIG_VIRT_CPU_ACCOUNTING_NATIVE) && defined(CONFIG_PPC_SPLPAR) -BEGIN_FW_FTR_SECTION - /* see if there are any DTL entries to process */ - ld r10,PACALPPACAPTR(r13) /* get ptr to VPA */ - ld r11,PACA_DTL_RIDX(r13) /* get log read index */ - addi r10,r10,LPPACA_DTLIDX - LDX_BE r10,0,r10 /* get log write index */ - cmpd r11,r10 - beq+ 33f - bl accumulate_stolen_time - REST_GPR(0,r1) - REST_4GPRS(3,r1) - REST_2GPRS(7,r1) - addi r9,r1,STACK_FRAME_OVERHEAD -33: -END_FW_FTR_SECTION_IFSET(FW_FEATURE_SPLPAR) -#endif /* CONFIG_VIRT_CPU_ACCOUNTING_NATIVE && CONFIG_PPC_SPLPAR */ - - /* - * A syscall should always be called with interrupts enabled - * so we just unconditionally hard-enable here. When some kind - * of irq tracing is used, we additionally check that condition - * is correct - */ -#if defined(CONFIG_PPC_IRQ_SOFT_MASK_DEBUG) && defined(CONFIG_BUG) - lbz r10,PACAIRQSOFTMASK(r13) -1: tdnei r10,IRQS_ENABLED - EMIT_BUG_ENTRY 1b,__FILE__,__LINE__,BUGFLAG_WARNING -#endif - -#ifdef CONFIG_PPC_BOOK3E - wrteei 1 -#else - li r11,MSR_RI - ori r11,r11,MSR_EE - mtmsrd r11,1 -#endif /* CONFIG_PPC_BOOK3E */ - -system_call: /* label this so stack traces look sane */ - /* We do need to set SOFTE in the stack frame or the return - * from interrupt will be painful - */ - li r10,IRQS_ENABLED - std r10,SOFTE(r1) + std r11,-16(r10) /* "regshere" marker */ - ld r11, PACA_THREAD_INFO(r13) - ld r10,TI_FLAGS(r11) - andi. r11,r10,_TIF_SYSCALL_DOTRACE - bne .Lsyscall_dotrace /* does not return */ - cmpldi 0,r0,NR_syscalls - bge- .Lsyscall_enosys - -.Lsyscall: -/* - * Need to vector to 32 Bit or default sys_call_table here, - * based on caller's run-mode / personality. - */ - ld r11,SYS_CALL_TABLE@toc(2) - andis. r10,r10,_TIF_32BIT@h - beq 15f - ld r11,COMPAT_SYS_CALL_TABLE@toc(2) - clrldi r3,r3,32 - clrldi r4,r4,32 - clrldi r5,r5,32 - clrldi r6,r6,32 - clrldi r7,r7,32 - clrldi r8,r8,32 -15: - slwi r0,r0,3 - - barrier_nospec_asm /* - * Prevent the load of the handler below (based on the user-passed - * system call number) being speculatively executed until the test - * against NR_syscalls and branch to .Lsyscall_enosys above has - * committed. + * RECONCILE_IRQ_STATE without calling trace_hardirqs_off(), which + * would clobber syscall parameters. Also we always enter with IRQs + * enabled and nothing pending. system_call_exception() will call + * trace_hardirqs_off(). */ + li r11,IRQS_ALL_DISABLED + li r12,PACA_IRQ_HARD_DIS + stb r11,PACAIRQSOFTMASK(r13) + stb r12,PACAIRQHAPPENED(r13) - ldx r12,r11,r0 /* Fetch system call handler [ptr] */ - mtctr r12 - bctrl /* Call handler */ + /* Calling convention has r9 = orig r0, r10 = regs */ + mr r9,r0 + bl system_call_exception - /* syscall_exit can exit to kernel mode, via ret_from_kernel_thread */ .Lsyscall_exit: - std r3,RESULT(r1) - -#ifdef CONFIG_DEBUG_RSEQ - /* Check whether the syscall is issued inside a restartable sequence */ - addi r3,r1,STACK_FRAME_OVERHEAD - bl rseq_syscall - ld r3,RESULT(r1) -#endif - - ld r12, PACA_THREAD_INFO(r13) - - ld r8,_MSR(r1) - -/* - * This is a few instructions into the actual syscall exit path (which actually - * starts at .Lsyscall_exit) to cater to kprobe blacklisting and to reduce the - * number of visible symbols for profiling purposes. - * - * We can probe from system_call until this point as MSR_RI is set. But once it - * is cleared below, we won't be able to take a trap. - * - * This is blacklisted from kprobes further below with _ASM_NOKPROBE_SYMBOL(). - */ -system_call_exit: - /* - * Disable interrupts so current_thread_info()->flags can't change, - * and so that we don't get interrupted after loading SRR0/1. - * - * Leave MSR_RI enabled for now, because with THREAD_INFO_IN_TASK we - * could fault on the load of the TI_FLAGS below. - */ -#ifdef CONFIG_PPC_BOOK3E - wrteei 0 -#else - li r11,MSR_RI - mtmsrd r11,1 -#endif /* CONFIG_PPC_BOOK3E */ + addi r4,r1,STACK_FRAME_OVERHEAD + bl syscall_exit_prepare - ld r9,TI_FLAGS(r12) - li r11,-MAX_ERRNO - andi. r0,r9,(_TIF_SYSCALL_DOTRACE|_TIF_SINGLESTEP|_TIF_USER_WORK_MASK|_TIF_PERSYSCALL_MASK) - bne- .Lsyscall_exit_work + ld r2,_CCR(r1) + ld r4,_NIP(r1) + ld r5,_MSR(r1) + ld r6,_LINK(r1) - andi. r0,r8,MSR_FP - beq 2f -#ifdef CONFIG_ALTIVEC - andis. r0,r8,MSR_VEC@h - bne 3f -#endif -2: addi r3,r1,STACK_FRAME_OVERHEAD - bl restore_math - ld r8,_MSR(r1) - ld r3,RESULT(r1) - li r11,-MAX_ERRNO - -3: cmpld r3,r11 - ld r5,_CCR(r1) - bge- .Lsyscall_error -.Lsyscall_error_cont: - ld r7,_NIP(r1) BEGIN_FTR_SECTION stdcx. r0,0,r1 /* to clear the reservation */ END_FTR_SECTION_IFCLR(CPU_FTR_STCX_CHECKS_ADDRESS) - andi. r6,r8,MSR_PR - ld r4,_LINK(r1) - kuap_check_amr r10, r11 + mtspr SPRN_SRR0,r4 + mtspr SPRN_SRR1,r5 + mtlr r6 -#ifdef CONFIG_PPC_BOOK3S - /* - * Clear MSR_RI, MSR_EE is already and remains disabled. We could do - * this later, but testing shows that doing it here causes less slow - * down than doing it closer to the rfid. - */ + cmpdi r3,0 + bne .Lsyscall_restore_regs + /* Zero volatile regs that may contain sensitive kernel data */ + li r0,0 + li r4,0 + li r5,0 + li r6,0 + li r7,0 + li r8,0 + li r9,0 + li r10,0 li r11,0 - mtmsrd r11,1 -#endif - - beq- 1f - ACCOUNT_CPU_USER_EXIT(r13, r11, r12) + li r12,0 + mtctr r0 + mtspr SPRN_XER,r0 +.Lsyscall_restore_regs_cont: BEGIN_FTR_SECTION HMT_MEDIUM_LOW END_FTR_SECTION_IFSET(CPU_FTR_HAS_PPR) -#ifdef CONFIG_PPC_TRANSACTIONAL_MEM - std r8, PACATMSCRATCH(r13) -#endif - /* * We don't need to restore AMR on the way back to userspace for KUAP. * The value of AMR only matters while we're in the kernel. */ - ld r13,GPR13(r1) /* only restore r13 if returning to usermode */ + mtcr r2 ld r2,GPR2(r1) + ld r3,GPR3(r1) + ld r13,GPR13(r1) ld r1,GPR1(r1) - mtlr r4 - mtcr r5 - mtspr SPRN_SRR0,r7 - mtspr SPRN_SRR1,r8 RFI_TO_USER b . /* prevent speculative execution */ -1: /* exit to kernel */ - kuap_restore_amr r2 - - ld r2,GPR2(r1) - ld r1,GPR1(r1) - mtlr r4 - mtcr r5 - mtspr SPRN_SRR0,r7 - mtspr SPRN_SRR1,r8 - RFI_TO_KERNEL - b . /* prevent speculative execution */ - -.Lsyscall_error: - oris r5,r5,0x1000 /* Set SO bit in CR */ - neg r3,r3 - std r5,_CCR(r1) - b .Lsyscall_error_cont - -/* Traced system call support */ -.Lsyscall_dotrace: - bl save_nvgprs - addi r3,r1,STACK_FRAME_OVERHEAD - bl do_syscall_trace_enter - - /* - * We use the return value of do_syscall_trace_enter() as the syscall - * number. If the syscall was rejected for any reason do_syscall_trace_enter() - * returns an invalid syscall number and the test below against - * NR_syscalls will fail. - */ - mr r0,r3 - - /* Restore argument registers just clobbered and/or possibly changed. */ - ld r3,GPR3(r1) - ld r4,GPR4(r1) - ld r5,GPR5(r1) - ld r6,GPR6(r1) - ld r7,GPR7(r1) - ld r8,GPR8(r1) - - /* Repopulate r9 and r10 for the syscall path */ - addi r9,r1,STACK_FRAME_OVERHEAD - ld r10, PACA_THREAD_INFO(r13) - ld r10,TI_FLAGS(r10) - - cmpldi r0,NR_syscalls - blt+ .Lsyscall - - /* Return code is already in r3 thanks to do_syscall_trace_enter() */ - b .Lsyscall_exit - - -.Lsyscall_enosys: - li r3,-ENOSYS - b .Lsyscall_exit - -.Lsyscall_exit_work: - /* If TIF_RESTOREALL is set, don't scribble on either r3 or ccr. - If TIF_NOERROR is set, just save r3 as it is. */ - - andi. r0,r9,_TIF_RESTOREALL - beq+ 0f +.Lsyscall_restore_regs: + ld r3,_CTR(r1) + ld r4,_XER(r1) REST_NVGPRS(r1) - b 2f -0: cmpld r3,r11 /* r11 is -MAX_ERRNO */ - blt+ 1f - andi. r0,r9,_TIF_NOERROR - bne- 1f - ld r5,_CCR(r1) - neg r3,r3 - oris r5,r5,0x1000 /* Set SO bit in CR */ - std r5,_CCR(r1) -1: std r3,GPR3(r1) -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: ldarx r10,0,r12 - andc r10,r10,r11 - stdcx. r10,0,r12 - bne- 3b - subi r12,r12,TI_FLAGS - -4: /* Anything else left to do? */ -BEGIN_FTR_SECTION - lis r3,DEFAULT_PPR@highest /* Set default PPR */ - sldi r3,r3,32 /* bits 11-13 are used for ppr */ - std r3,_PPR(r1) -END_FTR_SECTION_IFSET(CPU_FTR_HAS_PPR) - - andi. r0,r9,(_TIF_SYSCALL_DOTRACE|_TIF_SINGLESTEP) - beq ret_from_except_lite - - /* Re-enable interrupts */ -#ifdef CONFIG_PPC_BOOK3E - wrteei 1 -#else - li r10,MSR_RI - ori r10,r10,MSR_EE - mtmsrd r10,1 -#endif /* CONFIG_PPC_BOOK3E */ - - bl save_nvgprs - addi r3,r1,STACK_FRAME_OVERHEAD - bl do_syscall_trace_leave - b ret_from_except + mtctr r3 + mtspr SPRN_XER,r4 + ld r0,GPR0(r1) + REST_8GPRS(4, r1) + ld r12,GPR12(r1) + b .Lsyscall_restore_regs_cont #ifdef CONFIG_PPC_TRANSACTIONAL_MEM .Ltabort_syscall: @@ -439,64 +223,6 @@ END_FTR_SECTION_IFSET(CPU_FTR_HAS_PPR) RFI_TO_USER b . /* prevent speculative execution */ #endif -_ASM_NOKPROBE_SYMBOL(system_call_common); -_ASM_NOKPROBE_SYMBOL(system_call_exit); - -/* Save non-volatile GPRs, if not already saved. */ -_GLOBAL(save_nvgprs) - ld r11,_TRAP(r1) - andi. r0,r11,1 - beqlr- - SAVE_NVGPRS(r1) - clrrdi r0,r11,1 - std r0,_TRAP(r1) - blr -_ASM_NOKPROBE_SYMBOL(save_nvgprs); - - -/* - * The sigsuspend and rt_sigsuspend system calls can call do_signal - * and thus put the process into the stopped state where we might - * want to examine its user state with ptrace. Therefore we need - * to save all the nonvolatile registers (r14 - r31) before calling - * the C code. Similarly, fork, vfork and clone need the full - * register state on the stack so that it can be copied to the child. - */ - -_GLOBAL(ppc_fork) - bl save_nvgprs - bl sys_fork - b .Lsyscall_exit - -_GLOBAL(ppc_vfork) - bl save_nvgprs - bl sys_vfork - b .Lsyscall_exit - -_GLOBAL(ppc_clone) - bl save_nvgprs - bl sys_clone - b .Lsyscall_exit - -_GLOBAL(ppc_clone3) - bl save_nvgprs - bl sys_clone3 - b .Lsyscall_exit - -_GLOBAL(ppc32_swapcontext) - bl save_nvgprs - bl compat_sys_swapcontext - b .Lsyscall_exit - -_GLOBAL(ppc64_swapcontext) - bl save_nvgprs - bl sys_swapcontext - b .Lsyscall_exit - -_GLOBAL(ppc_switch_endian) - bl save_nvgprs - bl sys_switch_endian - b .Lsyscall_exit _GLOBAL(ret_from_fork) bl schedule_tail @@ -516,6 +242,19 @@ _GLOBAL(ret_from_kernel_thread) li r3,0 b .Lsyscall_exit +#ifdef CONFIG_PPC_BOOK3E +/* Save non-volatile GPRs, if not already saved. */ +_GLOBAL(save_nvgprs) + ld r11,_TRAP(r1) + andi. r0,r11,1 + beqlr- + SAVE_NVGPRS(r1) + clrrdi r0,r11,1 + std r0,_TRAP(r1) + blr +_ASM_NOKPROBE_SYMBOL(save_nvgprs); +#endif + #ifdef CONFIG_PPC_BOOK3S_64 #define FLUSH_COUNT_CACHE \ @@ -578,7 +317,7 @@ flush_count_cache: * 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, via ret_from_except. + * Finally, we can return to the second process, via interrupt_return. * On entry, r3 points to the THREAD for the current task, r4 * points to the THREAD for the new task. * @@ -730,408 +469,146 @@ END_FTR_SECTION_IFCLR(CPU_FTR_ARCH_207S) addi r1,r1,SWITCH_FRAME_SIZE blr - .align 7 -_GLOBAL(ret_from_except) - ld r11,_TRAP(r1) - andi. r0,r11,1 - bne ret_from_except_lite - REST_NVGPRS(r1) - -_GLOBAL(ret_from_except_lite) - /* - * Disable interrupts so that current_thread_info()->flags - * can't change between when we test it and when we return - * from the interrupt. - */ -#ifdef CONFIG_PPC_BOOK3E - wrteei 0 -#else - li r10,MSR_RI - mtmsrd r10,1 /* Update machine state */ -#endif /* CONFIG_PPC_BOOK3E */ - - ld r9, PACA_THREAD_INFO(r13) - ld r3,_MSR(r1) -#ifdef CONFIG_PPC_BOOK3E - ld r10,PACACURRENT(r13) -#endif /* CONFIG_PPC_BOOK3E */ - ld r4,TI_FLAGS(r9) - andi. r3,r3,MSR_PR - beq resume_kernel -#ifdef CONFIG_PPC_BOOK3E - lwz r3,(THREAD+THREAD_DBCR0)(r10) -#endif /* CONFIG_PPC_BOOK3E */ - - /* Check current_thread_info()->flags */ - andi. r0,r4,_TIF_USER_WORK_MASK - bne 1f -#ifdef CONFIG_PPC_BOOK3E +#ifdef CONFIG_PPC_BOOK3S /* - * Check to see if the dbcr0 register is set up to debug. - * Use the internal debug mode bit to do this. - */ - andis. r0,r3,DBCR0_IDM@h - beq restore - mfmsr r0 - rlwinm r0,r0,0,~MSR_DE /* Clear MSR.DE */ - mtmsr r0 - mtspr SPRN_DBCR0,r3 - li r10, -1 - mtspr SPRN_DBSR,r10 - b restore -#else - addi r3,r1,STACK_FRAME_OVERHEAD - bl restore_math - b restore -#endif -1: andi. r0,r4,_TIF_NEED_RESCHED - beq 2f - bl restore_interrupts - SCHEDULE_USER - b ret_from_except_lite -2: -#ifdef CONFIG_PPC_TRANSACTIONAL_MEM - andi. r0,r4,_TIF_USER_WORK_MASK & ~_TIF_RESTORE_TM - bne 3f /* only restore TM if nothing else to do */ + * If MSR EE/RI was never enabled, IRQs not reconciled, NVGPRs not + * touched, AMR not set, no exit work created, then this can be used. + */ + .balign IFETCH_ALIGN_BYTES + .globl fast_interrupt_return +fast_interrupt_return: +_ASM_NOKPROBE_SYMBOL(fast_interrupt_return) + ld r4,_MSR(r1) + andi. r0,r4,MSR_PR + bne .Lfast_user_interrupt_return + andi. r0,r4,MSR_RI + li r3,0 /* 0 return value, no EMULATE_STACK_STORE */ + bne+ .Lfast_kernel_interrupt_return addi r3,r1,STACK_FRAME_OVERHEAD - bl restore_tm_state - b restore -3: -#endif - bl save_nvgprs - /* - * Use a non volatile GPR to save and restore our thread_info flags - * across the call to restore_interrupts. - */ - mr r30,r4 - bl restore_interrupts - mr r4,r30 + bl unrecoverable_exception + b . /* should not get here */ + + .balign IFETCH_ALIGN_BYTES + .globl interrupt_return +interrupt_return: +_ASM_NOKPROBE_SYMBOL(interrupt_return) + ld r4,_MSR(r1) + andi. r0,r4,MSR_PR + beq .Lkernel_interrupt_return addi r3,r1,STACK_FRAME_OVERHEAD - bl do_notify_resume - b ret_from_except + bl interrupt_exit_user_prepare + cmpdi r3,0 + bne- .Lrestore_nvgprs -resume_kernel: - /* check current_thread_info, _TIF_EMULATE_STACK_STORE */ - andis. r8,r4,_TIF_EMULATE_STACK_STORE@h - beq+ 1f - - addi r8,r1,INT_FRAME_SIZE /* Get the kprobed function entry */ +.Lfast_user_interrupt_return: + ld r11,_NIP(r1) + ld r12,_MSR(r1) +BEGIN_FTR_SECTION + ld r10,_PPR(r1) + mtspr SPRN_PPR,r10 +END_FTR_SECTION_IFSET(CPU_FTR_HAS_PPR) + mtspr SPRN_SRR0,r11 + mtspr SPRN_SRR1,r12 - ld 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 */ +BEGIN_FTR_SECTION + stdcx. r0,0,r1 /* to clear the reservation */ +FTR_SECTION_ELSE + ldarx r0,0,r1 +ALT_FTR_SECTION_END_IFCLR(CPU_FTR_STCX_CHECKS_ADDRESS) - /* Copy from the original to the trampoline. */ - li r5,INT_FRAME_SIZE/8 /* size: INT_FRAME_SIZE */ - li r6,0 /* start offset: 0 */ - mtctr r5 -2: ldx r0,r6,r4 - stdx r0,r6,r3 - addi r6,r6,8 - bdnz 2b - - /* Do real store operation to complete stdu */ - ld r5,GPR1(r1) - std r8,0(r5) - - /* Clear _TIF_EMULATE_STACK_STORE flag */ - lis r11,_TIF_EMULATE_STACK_STORE@h - addi r5,r9,TI_FLAGS -0: ldarx r4,0,r5 - andc r4,r4,r11 - stdcx. r4,0,r5 - bne- 0b -1: - -#ifdef CONFIG_PREEMPTION - /* 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 cr0,r8,0 - bne restore - ld r0,SOFTE(r1) - andi. r0,r0,IRQS_DISABLED - bne restore + ld r3,_CCR(r1) + ld r4,_LINK(r1) + ld r5,_CTR(r1) + ld r6,_XER(r1) + li r0,0 - /* - * Here we are preempting the current task. We want to make - * sure we are soft-disabled first and reconcile irq state. - */ - RECONCILE_IRQ_STATE(r3,r4) - bl preempt_schedule_irq + REST_4GPRS(7, r1) + REST_2GPRS(11, r1) + REST_GPR(13, r1) - /* - * arch_local_irq_restore() from preempt_schedule_irq above may - * enable hard interrupt but we really should disable interrupts - * when we return from the interrupt, and so that we don't get - * interrupted after loading SRR0/1. - */ -#ifdef CONFIG_PPC_BOOK3E - wrteei 0 -#else - li r10,MSR_RI - mtmsrd r10,1 /* Update machine state */ -#endif /* CONFIG_PPC_BOOK3E */ -#endif /* CONFIG_PREEMPTION */ + mtcr r3 + mtlr r4 + mtctr r5 + mtspr SPRN_XER,r6 - .globl fast_exc_return_irq -fast_exc_return_irq: -restore: - /* - * This is the main kernel exit path. First we check if we - * are about to re-enable interrupts - */ - ld r5,SOFTE(r1) - lbz r6,PACAIRQSOFTMASK(r13) - andi. r5,r5,IRQS_DISABLED - bne .Lrestore_irq_off + REST_4GPRS(2, r1) + REST_GPR(6, r1) + REST_GPR(0, r1) + REST_GPR(1, r1) + RFI_TO_USER + b . /* prevent speculative execution */ - /* We are enabling, were we already enabled ? Yes, just return */ - andi. r6,r6,IRQS_DISABLED - beq cr0,.Ldo_restore +.Lrestore_nvgprs: + REST_NVGPRS(r1) + b .Lfast_user_interrupt_return - /* - * 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. - */ - lbz r0,PACAIRQHAPPENED(r13) - cmpwi cr0,r0,0 - bne- .Lrestore_check_irq_replay + .balign IFETCH_ALIGN_BYTES +.Lkernel_interrupt_return: + addi r3,r1,STACK_FRAME_OVERHEAD + bl interrupt_exit_kernel_prepare - /* - * Get here when nothing happened while soft-disabled, just - * soft-enable and move-on. We will hard-enable as a side - * effect of rfi - */ -.Lrestore_no_replay: - TRACE_ENABLE_INTS - li r0,IRQS_ENABLED - stb r0,PACAIRQSOFTMASK(r13); +.Lfast_kernel_interrupt_return: + cmpdi cr1,r3,0 + ld r11,_NIP(r1) + ld r12,_MSR(r1) + mtspr SPRN_SRR0,r11 + mtspr SPRN_SRR1,r12 - /* - * Final return path. BookE is handled in a different file - */ -.Ldo_restore: -#ifdef CONFIG_PPC_BOOK3E - b exception_return_book3e -#else - /* - * Clear the reservation. If we know the CPU tracks the address of - * the reservation then we can potentially save some cycles and use - * a larx. On POWER6 and POWER7 this is significantly faster. - */ BEGIN_FTR_SECTION stdcx. r0,0,r1 /* to clear the reservation */ FTR_SECTION_ELSE - ldarx r4,0,r1 + ldarx r0,0,r1 ALT_FTR_SECTION_END_IFCLR(CPU_FTR_STCX_CHECKS_ADDRESS) - /* - * Some code path such as load_up_fpu or altivec return directly - * here. They run entirely hard disabled and do not alter the - * interrupt state. They also don't use lwarx/stwcx. and thus - * are known not to leave dangling reservations. - */ - .globl fast_exception_return -fast_exception_return: - ld r3,_MSR(r1) + ld r3,_LINK(r1) ld r4,_CTR(r1) - ld r0,_LINK(r1) - mtctr r4 - mtlr r0 - ld r4,_XER(r1) - mtspr SPRN_XER,r4 - - kuap_check_amr r5, r6 - - REST_8GPRS(5, r1) - - andi. r0,r3,MSR_RI - beq- .Lunrecov_restore - - /* - * Clear RI before restoring r13. If we are returning to - * userspace and we take an exception after restoring r13, - * we end up corrupting the userspace r13 value. - */ - li r4,0 - mtmsrd r4,1 - -#ifdef CONFIG_PPC_TRANSACTIONAL_MEM - /* TM debug */ - std r3, PACATMSCRATCH(r13) /* Stash returned-to MSR */ -#endif - /* - * r13 is our per cpu area, only restore it if we are returning to - * userspace the value stored in the stack frame may belong to - * another CPU. - */ - andi. r0,r3,MSR_PR - beq 1f -BEGIN_FTR_SECTION - /* Restore PPR */ - ld r2,_PPR(r1) - mtspr SPRN_PPR,r2 -END_FTR_SECTION_IFSET(CPU_FTR_HAS_PPR) - ACCOUNT_CPU_USER_EXIT(r13, r2, r4) - REST_GPR(13, r1) - - /* - * We don't need to restore AMR on the way back to userspace for KUAP. - * The value of AMR only matters while we're in the kernel. - */ - mtspr SPRN_SRR1,r3 - - ld r2,_CCR(r1) - mtcrf 0xFF,r2 - ld r2,_NIP(r1) - mtspr SPRN_SRR0,r2 - - ld r0,GPR0(r1) - ld r2,GPR2(r1) - ld r3,GPR3(r1) - ld r4,GPR4(r1) - ld r1,GPR1(r1) - RFI_TO_USER - b . /* prevent speculative execution */ + ld r5,_XER(r1) + ld r6,_CCR(r1) + li r0,0 -1: mtspr SPRN_SRR1,r3 + REST_4GPRS(7, r1) + REST_2GPRS(11, r1) - ld r2,_CCR(r1) - mtcrf 0xFF,r2 - ld r2,_NIP(r1) - mtspr SPRN_SRR0,r2 + mtlr r3 + mtctr r4 + mtspr SPRN_XER,r5 /* * Leaving a stale exception_marker on the stack can confuse * the reliable stack unwinder later on. Clear it. */ - li r2,0 - std r2,STACK_FRAME_OVERHEAD-16(r1) - - ld r0,GPR0(r1) - ld r2,GPR2(r1) - ld r3,GPR3(r1) + std r0,STACK_FRAME_OVERHEAD-16(r1) - kuap_restore_amr r4 + REST_4GPRS(2, r1) - ld r4,GPR4(r1) - ld r1,GPR1(r1) + bne- cr1,1f /* emulate stack store */ + mtcr r6 + REST_GPR(6, r1) + REST_GPR(0, r1) + REST_GPR(1, r1) RFI_TO_KERNEL b . /* prevent speculative execution */ -#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 - */ -.Lrestore_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: -#if defined(CONFIG_PPC_IRQ_SOFT_MASK_DEBUG) && defined(CONFIG_BUG) - /* The interrupt should not have soft enabled. */ - lbz r7,PACAIRQSOFTMASK(r13) -1: tdeqi r7,IRQS_ENABLED - EMIT_BUG_ENTRY 1b,__FILE__,__LINE__,BUGFLAG_WARNING -#endif - b .Ldo_restore - - /* - * Something did happen, check if a re-emit is needed - * (this also clears paca->irq_happened) - */ -.Lrestore_check_irq_replay: - /* XXX: We could implement a fast path here where we check - * for irq_happened being just 0x01, in which case we can - * clear it and return. That means that we would potentially - * miss a decrementer having wrapped all the way around. - * - * Still, this might be useful for things like hash_page - */ - bl __check_irq_replay - cmpwi cr0,r3,0 - beq .Lrestore_no_replay - - /* - * We need to re-emit an interrupt. We do so by re-using our - * existing exception frame. We first change the trap value, - * but we need to ensure we preserve the low nibble of it - */ - ld r4,_TRAP(r1) - clrldi r4,r4,60 - or r4,r4,r3 - std r4,_TRAP(r1) - - /* - * PACA_IRQ_HARD_DIS won't always be set here, so set it now - * to reconcile the IRQ state. Tracing is already accounted for. - */ - lbz r4,PACAIRQHAPPENED(r13) - ori r4,r4,PACA_IRQ_HARD_DIS - stb r4,PACAIRQHAPPENED(r13) - - /* - * Then find the right handler and call it. Interrupts are - * still soft-disabled and we keep them that way. - */ - cmpwi cr0,r3,0x500 - bne 1f - addi r3,r1,STACK_FRAME_OVERHEAD; - bl do_IRQ - b ret_from_except -1: cmpwi cr0,r3,0xf00 - bne 1f - addi r3,r1,STACK_FRAME_OVERHEAD; - bl performance_monitor_exception - b ret_from_except -1: cmpwi cr0,r3,0xe60 - bne 1f - addi r3,r1,STACK_FRAME_OVERHEAD; - bl handle_hmi_exception - b ret_from_except -1: cmpwi cr0,r3,0x900 - bne 1f - addi r3,r1,STACK_FRAME_OVERHEAD; - bl timer_interrupt - b ret_from_except -#ifdef CONFIG_PPC_DOORBELL -1: -#ifdef CONFIG_PPC_BOOK3E - cmpwi cr0,r3,0x280 -#else - cmpwi cr0,r3,0xa00 -#endif /* CONFIG_PPC_BOOK3E */ - bne 1f - addi r3,r1,STACK_FRAME_OVERHEAD; - bl doorbell_exception -#endif /* CONFIG_PPC_DOORBELL */ -1: b ret_from_except /* What else to do here ? */ - -.Lunrecov_restore: - addi r3,r1,STACK_FRAME_OVERHEAD - bl unrecoverable_exception - b .Lunrecov_restore - -_ASM_NOKPROBE_SYMBOL(ret_from_except); -_ASM_NOKPROBE_SYMBOL(ret_from_except_lite); -_ASM_NOKPROBE_SYMBOL(resume_kernel); -_ASM_NOKPROBE_SYMBOL(fast_exc_return_irq); -_ASM_NOKPROBE_SYMBOL(restore); -_ASM_NOKPROBE_SYMBOL(fast_exception_return); +1: /* + * Emulate stack store with update. New r1 value was already calculated + * and updated in our interrupt regs by emulate_loadstore, but we can't + * store the previous value of r1 to the stack before re-loading our + * registers from it, otherwise they could be clobbered. Use + * PACA_EXGEN as temporary storage to hold the store data, as + * interrupts are disabled here so it won't be clobbered. + */ + mtcr r6 + std r9,PACA_EXGEN+0(r13) + addi r9,r1,INT_FRAME_SIZE /* get original r1 */ + REST_GPR(6, r1) + REST_GPR(0, r1) + REST_GPR(1, r1) + std r9,0(r1) /* perform store component of stdu */ + ld r9,PACA_EXGEN+0(r13) + RFI_TO_KERNEL + b . /* prevent speculative execution */ +#endif /* CONFIG_PPC_BOOK3S */ #ifdef CONFIG_PPC_RTAS /* |