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[209.132.180.67]) by mx.google.com with ESMTP id o14si2291401ejm.281.2019.11.27.02.43.37; Wed, 27 Nov 2019 02:44:02 -0800 (PST) Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67; Authentication-Results: mx.google.com; spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727304AbfK0KkB (ORCPT + 99 others); Wed, 27 Nov 2019 05:40:01 -0500 Received: from mx2.suse.de ([195.135.220.15]:56332 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1727247AbfK0KkA (ORCPT ); Wed, 27 Nov 2019 05:40:00 -0500 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.220.254]) by mx1.suse.de (Postfix) with ESMTP id 2F449B3E4; Wed, 27 Nov 2019 10:39:55 +0000 (UTC) From: Michal Suchanek To: linuxppc-dev@lists.ozlabs.org Cc: Benjamin Herrenschmidt , Paul Mackerras , Michael Ellerman , Oleg Nesterov , Alexander Viro , Christian Brauner , Nicholas Piggin , Allison Randal , "Naveen N. Rao" , Michal Suchanek , Thomas Gleixner , Breno Leitao , Christophe Leroy , Claudio Carvalho , Russell Currey , Greg Kroah-Hartman , Mahesh Salgaonkar , Arnd Bergmann , Geert Uytterhoeven , Firoz Khan , Dmitry Vyukov , Masahiro Yamada , Hari Bathini , Andrew Donnellan , Nicolai Stange , Valentin Schneider , Diana Craciun , Daniel Axtens , Michael Neuling , Gustavo Romero , Mathieu Malaterre , "Steven Rostedt" , "Eric W. Biederman" , Heiko Carstens , David Howells , Brajeswar Ghosh , Jagadeesh Pagadala , David Hildenbrand , Andrew Morton , Madhavan Srinivasan , linux-kernel@vger.kernel.org Subject: [PATCH v2 rebase 24/34] powerpc/64s: interrupt return in C Date: Wed, 27 Nov 2019 11:39:00 +0100 Message-Id: X-Mailer: git-send-email 2.23.0 In-Reply-To: References: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Nicholas Piggin Implement the bulk of interrupt return logic in C. The asm return code must handle a few cases: restoring full GPRs, and emulating stack store. The asm return code is moved into 64e for now. The new logic has made allowance for 64e, but I don't have a full environment that works well to test it, and even booting in emulated qemu is not great for stress testing. 64e shouldn't be too far off working with this, given a bit more testing and auditing of the logic. This is slightly faster on a POWER9 (page fault speed increases about 1.1%), probably due to reduced mtmsrd. Signed-off-by: Nicholas Piggin [ms: Move the FP restore functions to restore_math. They are not used anywhere else and when restore_math is not built gcc warns about them being unused. Add asm/context_tracking.h include to exceptions-64e.S for SCHEDULE_USER definition.] Signed-off-by: Michal Suchanek --- .../powerpc/include/asm/book3s/64/kup-radix.h | 10 + arch/powerpc/include/asm/switch_to.h | 6 + arch/powerpc/kernel/entry_64.S | 475 ++++-------------- arch/powerpc/kernel/exceptions-64e.S | 255 +++++++++- arch/powerpc/kernel/exceptions-64s.S | 119 ++--- arch/powerpc/kernel/process.c | 89 ++-- arch/powerpc/kernel/syscall_64.c | 157 +++++- arch/powerpc/kernel/vector.S | 2 +- 8 files changed, 623 insertions(+), 490 deletions(-) diff --git a/arch/powerpc/include/asm/book3s/64/kup-radix.h b/arch/powerpc/include/asm/book3s/64/kup-radix.h index 07058edc5970..762afbed4762 100644 --- a/arch/powerpc/include/asm/book3s/64/kup-radix.h +++ b/arch/powerpc/include/asm/book3s/64/kup-radix.h @@ -60,6 +60,12 @@ #include #include +static inline void kuap_restore_amr(struct pt_regs *regs) +{ + if (mmu_has_feature(MMU_FTR_RADIX_KUAP)) + mtspr(SPRN_AMR, regs->kuap); +} + static inline void kuap_check_amr(void) { if (IS_ENABLED(CONFIG_PPC_KUAP_DEBUG) && mmu_has_feature(MMU_FTR_RADIX_KUAP)) @@ -110,6 +116,10 @@ static inline bool bad_kuap_fault(struct pt_regs *regs, bool is_write) "Bug: %s fault blocked by AMR!", is_write ? "Write" : "Read"); } #else /* CONFIG_PPC_KUAP */ +static inline void kuap_restore_amr(struct pt_regs *regs) +{ +} + static inline void kuap_check_amr(void) { } diff --git a/arch/powerpc/include/asm/switch_to.h b/arch/powerpc/include/asm/switch_to.h index 476008bc3d08..b867b58b1093 100644 --- a/arch/powerpc/include/asm/switch_to.h +++ b/arch/powerpc/include/asm/switch_to.h @@ -23,7 +23,13 @@ extern void switch_booke_debug_regs(struct debug_reg *new_debug); extern int emulate_altivec(struct pt_regs *); +#ifdef CONFIG_PPC_BOOK3S_64 void restore_math(struct pt_regs *regs); +#else +static inline void restore_math(struct pt_regs *regs) +{ +} +#endif void restore_tm_state(struct pt_regs *regs); diff --git a/arch/powerpc/kernel/entry_64.S b/arch/powerpc/kernel/entry_64.S index 15bc2a872a76..b2e68f5ca8f7 100644 --- a/arch/powerpc/kernel/entry_64.S +++ b/arch/powerpc/kernel/entry_64.S @@ -16,6 +16,7 @@ #include #include +#include #include #include #include @@ -279,7 +280,7 @@ 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. * @@ -433,408 +434,150 @@ 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) +#ifdef CONFIG_PPC_BOOK3S /* - * 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 */ + * 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 +_GLOBAL(fast_interrupt_return) + ld r4,_MSR(r1) + andi. r0,r4,MSR_PR + bne .Lfast_user_interrupt_return + andi. r0,r4,MSR_RI + bne+ .Lfast_kernel_interrupt_return + addi r3,r1,STACK_FRAME_OVERHEAD + bl unrecoverable_exception + b . /* should not get here */ - 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 */ + .balign IFETCH_ALIGN_BYTES +_GLOBAL(interrupt_return) + REST_NVGPRS(r1) - /* Check current_thread_info()->flags */ - andi. r0,r4,_TIF_USER_WORK_MASK - bne 1f -#ifdef CONFIG_PPC_BOOK3E - /* - * 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 + .balign IFETCH_ALIGN_BYTES +_GLOBAL(interrupt_return_lite) + ld r4,_MSR(r1) + andi. r0,r4,MSR_PR + beq kernel_interrupt_return +user_interrupt_return: 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 */ - 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 - addi r3,r1,STACK_FRAME_OVERHEAD - bl do_notify_resume - b ret_from_except - -resume_kernel: - /* check current_thread_info, _TIF_EMULATE_STACK_STORE */ - andis. r8,r4,_TIF_EMULATE_STACK_STORE@h - beq+ 1f + bl interrupt_exit_user_prepare + cmpdi r3,0 + bne- .Lrestore_nvgprs - 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_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 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_PREEMPT */ + 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 +kernel_interrupt_return: + addi r3,r1,STACK_FRAME_OVERHEAD + bl interrupt_exit_kernel_prepare + cmpdi cr1,r3,0 - /* - * 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: + 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 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) + ld r3,_CCR(r1) + ld r4,_LINK(r1) + ld r5,_CTR(r1) + ld r6,_XER(r1) + li r0,0 - andi. r0,r3,MSR_RI - beq- .Lunrecov_restore + REST_4GPRS(7, r1) + REST_2GPRS(11, r1) - /* - * 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) + bne- cr1,1f /* emulate stack store */ + mtcr r3 + mtlr r4 + mtctr r5 + mtspr SPRN_XER,r6 /* - * 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. + * Leaving a stale exception_marker on the stack can confuse + * the reliable stack unwinder later on. Clear it. */ - mtspr SPRN_SRR1,r3 - - ld r2,_CCR(r1) - mtcrf 0xFF,r2 - ld r2,_NIP(r1) - mtspr SPRN_SRR0,r2 + std r0,STACK_FRAME_OVERHEAD-16(r1) - ld r0,GPR0(r1) - ld r2,GPR2(r1) - ld r3,GPR3(r1) - ld r4,GPR4(r1) - ld r1,GPR1(r1) - RFI_TO_USER + REST_4GPRS(2, r1) + REST_GPR(6, r1) + REST_GPR(0, r1) + REST_GPR(1, r1) + RFI_TO_KERNEL b . /* prevent speculative execution */ -1: mtspr SPRN_SRR1,r3 - - ld r2,_CCR(r1) - mtcrf 0xFF,r2 - ld r2,_NIP(r1) - mtspr SPRN_SRR0,r2 +1: mtcr r3 + mtlr r4 + mtctr r5 + mtspr SPRN_XER,r6 /* * 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) + std r0,STACK_FRAME_OVERHEAD-16(r1) - ld r0,GPR0(r1) - ld r2,GPR2(r1) - ld r3,GPR3(r1) + REST_4GPRS(2, r1) + REST_GPR(6, r1) + REST_GPR(0, r1) - kuap_restore_amr r4 + /* Nasty emulate stack store case. */ + std r9,PACA_EXGEN+0(r13) + addi r9,r1,INT_FRAME_SIZE /* get original r1 */ + REST_GPR(1, r1) + std r9,0(r1) + ld r9,PACA_EXGEN+0(r13) - ld r4,GPR4(r1) - ld r1,GPR1(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); - +#endif /* CONFIG_PPC_BOOK3S */ #ifdef CONFIG_PPC_RTAS /* diff --git a/arch/powerpc/kernel/exceptions-64e.S b/arch/powerpc/kernel/exceptions-64e.S index e4076e3c072d..f7ca46f2a38e 100644 --- a/arch/powerpc/kernel/exceptions-64e.S +++ b/arch/powerpc/kernel/exceptions-64e.S @@ -24,6 +24,7 @@ #include #include #include +#include /* XXX This will ultimately add space for a special exception save * structure used to save things like SRR0/SRR1, SPRGs, MAS, etc... @@ -1073,17 +1074,161 @@ alignment_more: bl alignment_exception b ret_from_except -/* - * We branch here from entry_64.S for the last stage of the exception - * return code path. MSR:EE is expected to be off at that point - */ -_GLOBAL(exception_return_book3e) - b 1f + .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. + */ + wrteei 0 + + ld r9, PACA_THREAD_INFO(r13) + ld r3,_MSR(r1) + ld r10,PACACURRENT(r13) + ld r4,TI_FLAGS(r9) + andi. r3,r3,MSR_PR + beq resume_kernel + lwz r3,(THREAD+THREAD_DBCR0)(r10) + + /* Check current_thread_info()->flags */ + andi. r0,r4,_TIF_USER_WORK_MASK + bne 1f + /* + * 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 +1: andi. r0,r4,_TIF_NEED_RESCHED + beq 2f + bl restore_interrupts + SCHEDULE_USER + b ret_from_except_lite +2: + 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 + addi r3,r1,STACK_FRAME_OVERHEAD + bl do_notify_resume + b ret_from_except + +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 */ + + 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 */ + + /* 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_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 cr0,r8,0 + bne restore + ld r0,SOFTE(r1) + andi. r0,r0,IRQS_DISABLED + bne restore + + /* + * 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 + + /* + * 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. + */ + wrteei 0 +#endif /* CONFIG_PREEMPT */ + +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 + + /* We are enabling, were we already enabled ? Yes, just return */ + andi. r6,r6,IRQS_DISABLED + beq cr0,fast_exception_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 + + /* + * 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); /* This is the return from load_up_fpu fast path which could do with * less GPR restores in fact, but for now we have a single return path */ - .globl fast_exception_return fast_exception_return: wrteei 0 1: mr r0,r13 @@ -1124,6 +1269,102 @@ fast_exception_return: mfspr r13,SPRN_SPRG_GEN_SCRATCH rfi + /* + * 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 fast_exception_return + + /* + * 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: + cmpwi cr0,r3,0x280 + 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 ? */ + +_ASM_NOKPROBE_SYMBOL(ret_from_except); +_ASM_NOKPROBE_SYMBOL(ret_from_except_lite); +_ASM_NOKPROBE_SYMBOL(resume_kernel); +_ASM_NOKPROBE_SYMBOL(restore); +_ASM_NOKPROBE_SYMBOL(fast_exception_return); + /* * Trampolines used when spotting a bad kernel stack pointer in * the exception entry code. diff --git a/arch/powerpc/kernel/exceptions-64s.S b/arch/powerpc/kernel/exceptions-64s.S index af1264cd005f..269edd1460be 100644 --- a/arch/powerpc/kernel/exceptions-64s.S +++ b/arch/powerpc/kernel/exceptions-64s.S @@ -575,6 +575,8 @@ END_FTR_SECTION_IFSET(CPU_FTR_HAS_PPR) std r10,GPR12(r1) std r11,GPR13(r1) + SAVE_NVGPRS(r1) + .if IDAR .if IISIDE ld r10,_NIP(r1) @@ -611,7 +613,7 @@ END_FTR_SECTION_IFSET(CPU_FTR_CFAR) mfspr r11,SPRN_XER /* save XER in stackframe */ std r10,SOFTE(r1) std r11,_XER(r1) - li r9,(IVEC)+1 + li r9,IVEC std r9,_TRAP(r1) /* set trap number */ li r10,0 ld r11,exception_marker@toc(r2) @@ -918,7 +920,6 @@ EXC_COMMON_BEGIN(system_reset_common) ld r1,PACA_NMI_EMERG_SP(r13) subi r1,r1,INT_FRAME_SIZE __GEN_COMMON_BODY system_reset - bl save_nvgprs /* * Set IRQS_ALL_DISABLED unconditionally so arch_irqs_disabled does * the right thing. We do not want to reconcile because that goes @@ -1093,7 +1094,6 @@ END_FTR_SECTION_IFSET(CPU_FTR_HVMODE) li r10,MSR_RI mtmsrd r10,1 - bl save_nvgprs addi r3,r1,STACK_FRAME_OVERHEAD bl machine_check_early std r3,RESULT(r1) /* Save result */ @@ -1186,10 +1186,9 @@ EXC_COMMON_BEGIN(machine_check_common) /* Enable MSR_RI when finished with PACA_EXMC */ li r10,MSR_RI mtmsrd r10,1 - bl save_nvgprs addi r3,r1,STACK_FRAME_OVERHEAD bl machine_check_exception - b ret_from_except + b interrupt_return GEN_KVM machine_check @@ -1356,20 +1355,19 @@ BEGIN_MMU_FTR_SECTION bl do_slb_fault cmpdi r3,0 bne- 1f - b fast_exception_return + b fast_interrupt_return 1: /* Error case */ MMU_FTR_SECTION_ELSE /* Radix case, access is outside page table range */ li r3,-EFAULT ALT_MMU_FTR_SECTION_END_IFCLR(MMU_FTR_TYPE_RADIX) std r3,RESULT(r1) - bl save_nvgprs RECONCILE_IRQ_STATE(r10, r11) ld r4,_DAR(r1) ld r5,RESULT(r1) addi r3,r1,STACK_FRAME_OVERHEAD bl do_bad_slb_fault - b ret_from_except + b interrupt_return GEN_KVM data_access_slb @@ -1449,20 +1447,19 @@ BEGIN_MMU_FTR_SECTION bl do_slb_fault cmpdi r3,0 bne- 1f - b fast_exception_return + b fast_interrupt_return 1: /* Error case */ MMU_FTR_SECTION_ELSE /* Radix case, access is outside page table range */ li r3,-EFAULT ALT_MMU_FTR_SECTION_END_IFCLR(MMU_FTR_TYPE_RADIX) std r3,RESULT(r1) - bl save_nvgprs RECONCILE_IRQ_STATE(r10, r11) ld r4,_DAR(r1) ld r5,RESULT(r1) addi r3,r1,STACK_FRAME_OVERHEAD bl do_bad_slb_fault - b ret_from_except + b interrupt_return GEN_KVM instruction_access_slb @@ -1510,7 +1507,7 @@ EXC_COMMON_BEGIN(hardware_interrupt_common) RUNLATCH_ON addi r3,r1,STACK_FRAME_OVERHEAD bl do_IRQ - b ret_from_except_lite + b interrupt_return_lite GEN_KVM hardware_interrupt @@ -1536,10 +1533,9 @@ EXC_VIRT_BEGIN(alignment, 0x4600, 0x100) EXC_VIRT_END(alignment, 0x4600, 0x100) EXC_COMMON_BEGIN(alignment_common) GEN_COMMON alignment - bl save_nvgprs addi r3,r1,STACK_FRAME_OVERHEAD bl alignment_exception - b ret_from_except + b interrupt_return GEN_KVM alignment @@ -1600,10 +1596,9 @@ EXC_COMMON_BEGIN(program_check_common) __ISTACK(program_check)=1 __GEN_COMMON_BODY program_check 3: - bl save_nvgprs addi r3,r1,STACK_FRAME_OVERHEAD bl program_check_exception - b ret_from_except + b interrupt_return GEN_KVM program_check @@ -1634,7 +1629,6 @@ EXC_VIRT_END(fp_unavailable, 0x4800, 0x100) EXC_COMMON_BEGIN(fp_unavailable_common) GEN_COMMON fp_unavailable bne 1f /* if from user, just load it up */ - bl save_nvgprs RECONCILE_IRQ_STATE(r10, r11) addi r3,r1,STACK_FRAME_OVERHEAD bl kernel_fp_unavailable_exception @@ -1651,14 +1645,13 @@ BEGIN_FTR_SECTION END_FTR_SECTION_IFSET(CPU_FTR_TM) #endif bl load_up_fpu - b fast_exception_return + b fast_interrupt_return #ifdef CONFIG_PPC_TRANSACTIONAL_MEM 2: /* User process was in a transaction */ - bl save_nvgprs RECONCILE_IRQ_STATE(r10, r11) addi r3,r1,STACK_FRAME_OVERHEAD bl fp_unavailable_tm - b ret_from_except + b interrupt_return #endif GEN_KVM fp_unavailable @@ -1701,7 +1694,7 @@ EXC_COMMON_BEGIN(decrementer_common) RUNLATCH_ON addi r3,r1,STACK_FRAME_OVERHEAD bl timer_interrupt - b ret_from_except_lite + b interrupt_return_lite GEN_KVM decrementer @@ -1792,7 +1785,7 @@ EXC_COMMON_BEGIN(doorbell_super_common) #else bl unknown_exception #endif - b ret_from_except_lite + b interrupt_return_lite GEN_KVM doorbell_super @@ -1977,10 +1970,9 @@ EXC_VIRT_BEGIN(single_step, 0x4d00, 0x100) EXC_VIRT_END(single_step, 0x4d00, 0x100) EXC_COMMON_BEGIN(single_step_common) GEN_COMMON single_step - bl save_nvgprs addi r3,r1,STACK_FRAME_OVERHEAD bl single_step_exception - b ret_from_except + b interrupt_return GEN_KVM single_step @@ -2015,7 +2007,6 @@ EXC_VIRT_BEGIN(h_data_storage, 0x4e00, 0x20) EXC_VIRT_END(h_data_storage, 0x4e00, 0x20) EXC_COMMON_BEGIN(h_data_storage_common) GEN_COMMON h_data_storage - bl save_nvgprs addi r3,r1,STACK_FRAME_OVERHEAD BEGIN_MMU_FTR_SECTION ld r4,_DAR(r1) @@ -2024,7 +2015,7 @@ BEGIN_MMU_FTR_SECTION MMU_FTR_SECTION_ELSE bl unknown_exception ALT_MMU_FTR_SECTION_END_IFSET(MMU_FTR_TYPE_RADIX) - b ret_from_except + b interrupt_return GEN_KVM h_data_storage @@ -2049,10 +2040,9 @@ EXC_VIRT_BEGIN(h_instr_storage, 0x4e20, 0x20) EXC_VIRT_END(h_instr_storage, 0x4e20, 0x20) EXC_COMMON_BEGIN(h_instr_storage_common) GEN_COMMON h_instr_storage - bl save_nvgprs addi r3,r1,STACK_FRAME_OVERHEAD bl unknown_exception - b ret_from_except + b interrupt_return GEN_KVM h_instr_storage @@ -2075,10 +2065,9 @@ EXC_VIRT_BEGIN(emulation_assist, 0x4e40, 0x20) EXC_VIRT_END(emulation_assist, 0x4e40, 0x20) EXC_COMMON_BEGIN(emulation_assist_common) GEN_COMMON emulation_assist - bl save_nvgprs addi r3,r1,STACK_FRAME_OVERHEAD bl emulation_assist_interrupt - b ret_from_except + b interrupt_return GEN_KVM emulation_assist @@ -2158,10 +2147,9 @@ EXC_COMMON_BEGIN(hmi_exception_common) GEN_COMMON hmi_exception FINISH_NAP RUNLATCH_ON - bl save_nvgprs addi r3,r1,STACK_FRAME_OVERHEAD bl handle_hmi_exception - b ret_from_except + b interrupt_return GEN_KVM hmi_exception @@ -2195,7 +2183,7 @@ EXC_COMMON_BEGIN(h_doorbell_common) #else bl unknown_exception #endif - b ret_from_except_lite + b interrupt_return_lite GEN_KVM h_doorbell @@ -2225,7 +2213,7 @@ EXC_COMMON_BEGIN(h_virt_irq_common) RUNLATCH_ON addi r3,r1,STACK_FRAME_OVERHEAD bl do_IRQ - b ret_from_except_lite + b interrupt_return_lite GEN_KVM h_virt_irq @@ -2272,7 +2260,7 @@ EXC_COMMON_BEGIN(performance_monitor_common) RUNLATCH_ON addi r3,r1,STACK_FRAME_OVERHEAD bl performance_monitor_exception - b ret_from_except_lite + b interrupt_return_lite GEN_KVM performance_monitor @@ -2312,23 +2300,21 @@ BEGIN_FTR_SECTION END_FTR_SECTION_NESTED(CPU_FTR_TM, CPU_FTR_TM, 69) #endif bl load_up_altivec - b fast_exception_return + b fast_interrupt_return #ifdef CONFIG_PPC_TRANSACTIONAL_MEM 2: /* User process was in a transaction */ - bl save_nvgprs RECONCILE_IRQ_STATE(r10, r11) addi r3,r1,STACK_FRAME_OVERHEAD bl altivec_unavailable_tm - b ret_from_except + b interrupt_return #endif 1: END_FTR_SECTION_IFSET(CPU_FTR_ALTIVEC) #endif - bl save_nvgprs RECONCILE_IRQ_STATE(r10, r11) addi r3,r1,STACK_FRAME_OVERHEAD bl altivec_unavailable_exception - b ret_from_except + b interrupt_return GEN_KVM altivec_unavailable @@ -2370,20 +2356,18 @@ BEGIN_FTR_SECTION b load_up_vsx #ifdef CONFIG_PPC_TRANSACTIONAL_MEM 2: /* User process was in a transaction */ - bl save_nvgprs RECONCILE_IRQ_STATE(r10, r11) addi r3,r1,STACK_FRAME_OVERHEAD bl vsx_unavailable_tm - b ret_from_except + b interrupt_return #endif 1: END_FTR_SECTION_IFSET(CPU_FTR_VSX) #endif - bl save_nvgprs RECONCILE_IRQ_STATE(r10, r11) addi r3,r1,STACK_FRAME_OVERHEAD bl vsx_unavailable_exception - b ret_from_except + b interrupt_return GEN_KVM vsx_unavailable @@ -2410,10 +2394,9 @@ EXC_VIRT_BEGIN(facility_unavailable, 0x4f60, 0x20) EXC_VIRT_END(facility_unavailable, 0x4f60, 0x20) EXC_COMMON_BEGIN(facility_unavailable_common) GEN_COMMON facility_unavailable - bl save_nvgprs addi r3,r1,STACK_FRAME_OVERHEAD bl facility_unavailable_exception - b ret_from_except + b interrupt_return GEN_KVM facility_unavailable @@ -2440,10 +2423,9 @@ EXC_VIRT_BEGIN(h_facility_unavailable, 0x4f80, 0x20) EXC_VIRT_END(h_facility_unavailable, 0x4f80, 0x20) EXC_COMMON_BEGIN(h_facility_unavailable_common) GEN_COMMON h_facility_unavailable - bl save_nvgprs addi r3,r1,STACK_FRAME_OVERHEAD bl facility_unavailable_exception - b ret_from_except + b interrupt_return GEN_KVM h_facility_unavailable @@ -2474,10 +2456,9 @@ EXC_REAL_END(cbe_system_error, 0x1200, 0x100) EXC_VIRT_NONE(0x5200, 0x100) EXC_COMMON_BEGIN(cbe_system_error_common) GEN_COMMON cbe_system_error - bl save_nvgprs addi r3,r1,STACK_FRAME_OVERHEAD bl cbe_system_error_exception - b ret_from_except + b interrupt_return GEN_KVM cbe_system_error @@ -2503,10 +2484,9 @@ EXC_VIRT_BEGIN(instruction_breakpoint, 0x5300, 0x100) EXC_VIRT_END(instruction_breakpoint, 0x5300, 0x100) EXC_COMMON_BEGIN(instruction_breakpoint_common) GEN_COMMON instruction_breakpoint - bl save_nvgprs addi r3,r1,STACK_FRAME_OVERHEAD bl instruction_breakpoint_exception - b ret_from_except + b interrupt_return GEN_KVM instruction_breakpoint @@ -2626,10 +2606,9 @@ END_FTR_SECTION_IFSET(CPU_FTR_CFAR) EXC_COMMON_BEGIN(denorm_exception_common) GEN_COMMON denorm_exception - bl save_nvgprs addi r3,r1,STACK_FRAME_OVERHEAD bl unknown_exception - b ret_from_except + b interrupt_return GEN_KVM denorm_exception @@ -2648,10 +2627,9 @@ EXC_REAL_END(cbe_maintenance, 0x1600, 0x100) EXC_VIRT_NONE(0x5600, 0x100) EXC_COMMON_BEGIN(cbe_maintenance_common) GEN_COMMON cbe_maintenance - bl save_nvgprs addi r3,r1,STACK_FRAME_OVERHEAD bl cbe_maintenance_exception - b ret_from_except + b interrupt_return GEN_KVM cbe_maintenance @@ -2676,14 +2654,13 @@ EXC_VIRT_BEGIN(altivec_assist, 0x5700, 0x100) EXC_VIRT_END(altivec_assist, 0x5700, 0x100) EXC_COMMON_BEGIN(altivec_assist_common) GEN_COMMON altivec_assist - bl save_nvgprs addi r3,r1,STACK_FRAME_OVERHEAD #ifdef CONFIG_ALTIVEC bl altivec_assist_exception #else bl unknown_exception #endif - b ret_from_except + b interrupt_return GEN_KVM altivec_assist @@ -2702,10 +2679,9 @@ EXC_REAL_END(cbe_thermal, 0x1800, 0x100) EXC_VIRT_NONE(0x5800, 0x100) EXC_COMMON_BEGIN(cbe_thermal_common) GEN_COMMON cbe_thermal - bl save_nvgprs addi r3,r1,STACK_FRAME_OVERHEAD bl cbe_thermal_exception - b ret_from_except + b interrupt_return GEN_KVM cbe_thermal @@ -2737,7 +2713,6 @@ EXC_COMMON_BEGIN(soft_nmi_common) ld r1,PACAEMERGSP(r13) subi r1,r1,INT_FRAME_SIZE __GEN_COMMON_BODY soft_nmi - bl save_nvgprs addi r3,r1,STACK_FRAME_OVERHEAD bl soft_nmi_interrupt /* Clear MSR_RI before setting SRR0 and SRR1. */ @@ -3038,7 +3013,7 @@ do_hash_page: cmpdi r3,0 /* see if __hash_page succeeded */ /* Success */ - beq fast_exc_return_irq /* Return from exception on success */ + beq interrupt_return_lite /* Return from exception on success */ /* Error */ blt- 13f @@ -3055,17 +3030,15 @@ handle_page_fault: addi r3,r1,STACK_FRAME_OVERHEAD bl do_page_fault cmpdi r3,0 - beq+ ret_from_except_lite - bl save_nvgprs + beq+ interrupt_return_lite mr r5,r3 addi r3,r1,STACK_FRAME_OVERHEAD ld r4,_DAR(r1) bl bad_page_fault - b ret_from_except + b interrupt_return /* We have a data breakpoint exception - handle it */ handle_dabr_fault: - bl save_nvgprs ld r4,_DAR(r1) ld r5,_DSISR(r1) addi r3,r1,STACK_FRAME_OVERHEAD @@ -3073,21 +3046,20 @@ handle_dabr_fault: /* * do_break() may have changed the NV GPRS while handling a breakpoint. * If so, we need to restore them with their updated values. Don't use - * ret_from_except_lite here. + * interrupt_return_lite here. */ - b ret_from_except + b interrupt_return #ifdef CONFIG_PPC_BOOK3S_64 /* We have a page fault that hash_page could handle but HV refused * the PTE insertion */ -13: bl save_nvgprs - mr r5,r3 +13: mr r5,r3 addi r3,r1,STACK_FRAME_OVERHEAD ld r4,_DAR(r1) bl low_hash_fault - b ret_from_except + b interrupt_return #endif /* @@ -3097,11 +3069,10 @@ handle_dabr_fault: * were soft-disabled. We want to invoke the exception handler for * the access, or panic if there isn't a handler. */ -77: bl save_nvgprs - addi r3,r1,STACK_FRAME_OVERHEAD +77: addi r3,r1,STACK_FRAME_OVERHEAD li r5,SIGSEGV bl bad_page_fault - b ret_from_except + b interrupt_return /* * When doorbell is triggered from system reset wakeup, the message is diff --git a/arch/powerpc/kernel/process.c b/arch/powerpc/kernel/process.c index 4df94b6e2f32..b5f8433f8b46 100644 --- a/arch/powerpc/kernel/process.c +++ b/arch/powerpc/kernel/process.c @@ -236,23 +236,9 @@ void enable_kernel_fp(void) } } EXPORT_SYMBOL(enable_kernel_fp); - -static int restore_fp(struct task_struct *tsk) -{ - if (tsk->thread.load_fp) { - load_fp_state(¤t->thread.fp_state); - current->thread.load_fp++; - return 1; - } - return 0; -} -#else -static int restore_fp(struct task_struct *tsk) { return 0; } #endif /* CONFIG_PPC_FPU */ #ifdef CONFIG_ALTIVEC -#define loadvec(thr) ((thr).load_vec) - static void __giveup_altivec(struct task_struct *tsk) { unsigned long msr; @@ -318,21 +304,6 @@ void flush_altivec_to_thread(struct task_struct *tsk) } } EXPORT_SYMBOL_GPL(flush_altivec_to_thread); - -static int restore_altivec(struct task_struct *tsk) -{ - if (cpu_has_feature(CPU_FTR_ALTIVEC) && (tsk->thread.load_vec)) { - load_vr_state(&tsk->thread.vr_state); - tsk->thread.used_vr = 1; - tsk->thread.load_vec++; - - return 1; - } - return 0; -} -#else -#define loadvec(thr) 0 -static inline int restore_altivec(struct task_struct *tsk) { return 0; } #endif /* CONFIG_ALTIVEC */ #ifdef CONFIG_VSX @@ -400,18 +371,6 @@ void flush_vsx_to_thread(struct task_struct *tsk) } } EXPORT_SYMBOL_GPL(flush_vsx_to_thread); - -static int restore_vsx(struct task_struct *tsk) -{ - if (cpu_has_feature(CPU_FTR_VSX)) { - tsk->thread.used_vsr = 1; - return 1; - } - - return 0; -} -#else -static inline int restore_vsx(struct task_struct *tsk) { return 0; } #endif /* CONFIG_VSX */ #ifdef CONFIG_SPE @@ -511,6 +470,53 @@ void giveup_all(struct task_struct *tsk) } EXPORT_SYMBOL(giveup_all); +#ifdef CONFIG_PPC_BOOK3S_64 +#ifdef CONFIG_PPC_FPU +static int restore_fp(struct task_struct *tsk) +{ + if (tsk->thread.load_fp) { + load_fp_state(¤t->thread.fp_state); + current->thread.load_fp++; + return 1; + } + return 0; +} +#else +static int restore_fp(struct task_struct *tsk) { return 0; } +#endif /* CONFIG_PPC_FPU */ + +#ifdef CONFIG_ALTIVEC +#define loadvec(thr) ((thr).load_vec) +static int restore_altivec(struct task_struct *tsk) +{ + if (cpu_has_feature(CPU_FTR_ALTIVEC) && (tsk->thread.load_vec)) { + load_vr_state(&tsk->thread.vr_state); + tsk->thread.used_vr = 1; + tsk->thread.load_vec++; + + return 1; + } + return 0; +} +#else +#define loadvec(thr) 0 +static inline int restore_altivec(struct task_struct *tsk) { return 0; } +#endif /* CONFIG_ALTIVEC */ + +#ifdef CONFIG_VSX +static int restore_vsx(struct task_struct *tsk) +{ + if (cpu_has_feature(CPU_FTR_VSX)) { + tsk->thread.used_vsr = 1; + return 1; + } + + return 0; +} +#else +static inline int restore_vsx(struct task_struct *tsk) { return 0; } +#endif /* CONFIG_VSX */ + /* * The exception exit path calls restore_math() with interrupts hard disabled * but the soft irq state not "reconciled". ftrace code that calls @@ -551,6 +557,7 @@ void notrace restore_math(struct pt_regs *regs) regs->msr = msr; } +#endif static void save_all(struct task_struct *tsk) { diff --git a/arch/powerpc/kernel/syscall_64.c b/arch/powerpc/kernel/syscall_64.c index ce4e1b5a9c27..d00cfc4a39a9 100644 --- a/arch/powerpc/kernel/syscall_64.c +++ b/arch/powerpc/kernel/syscall_64.c @@ -20,7 +20,11 @@ long system_call_exception(long r3, long r4, long r5, long r6, long r7, long r8, unsigned long ti_flags; syscall_fn f; + if (IS_ENABLED(CONFIG_PPC_BOOK3S)) + BUG_ON(!(regs->msr & MSR_RI)); BUG_ON(!(regs->msr & MSR_PR)); + BUG_ON(!FULL_REGS(regs)); + BUG_ON(regs->softe != IRQS_ENABLED); if (IS_ENABLED(CONFIG_PPC_TRANSACTIONAL_MEM) && unlikely(regs->msr & MSR_TS_T)) @@ -177,7 +181,7 @@ notrace unsigned long syscall_exit_prepare(unsigned long r3, struct pt_regs *reg trace_hardirqs_off(); local_paca->irq_happened |= PACA_IRQ_HARD_DIS; local_irq_enable(); - /* Took an interrupt which may have more exit work to do. */ + /* Took an interrupt, may have more exit work to do. */ goto again; } local_paca->irq_happened &= ~PACA_IRQ_HARD_DIS; @@ -193,3 +197,154 @@ notrace unsigned long syscall_exit_prepare(unsigned long r3, struct pt_regs *reg return ret; } + +#ifdef CONFIG_PPC_BOOK3S /* BOOK3E not yet using this */ +notrace unsigned long interrupt_exit_user_prepare(struct pt_regs *regs, unsigned long msr) +{ +#ifdef CONFIG_PPC_BOOK3E + struct thread_struct *ts = ¤t->thread; +#endif + unsigned long *ti_flagsp = ¤t_thread_info()->flags; + unsigned long ti_flags; + unsigned long flags; + unsigned long ret = 0; + + if (IS_ENABLED(CONFIG_PPC_BOOK3S)) + BUG_ON(!(regs->msr & MSR_RI)); + BUG_ON(!(regs->msr & MSR_PR)); + BUG_ON(!FULL_REGS(regs)); + BUG_ON(regs->softe != IRQS_ENABLED); + + local_irq_save(flags); + +again: + ti_flags = READ_ONCE(*ti_flagsp); + while (unlikely(ti_flags & (_TIF_USER_WORK_MASK & ~_TIF_RESTORE_TM))) { + local_irq_enable(); /* returning to user: may enable */ + if (ti_flags & _TIF_NEED_RESCHED) { + schedule(); + } else { + if (ti_flags & _TIF_SIGPENDING) + ret |= _TIF_RESTOREALL; + do_notify_resume(regs, ti_flags); + } + local_irq_disable(); + ti_flags = READ_ONCE(*ti_flagsp); + } + + if (IS_ENABLED(CONFIG_PPC_BOOK3S)) { + unsigned long mathflags = 0; + + if (IS_ENABLED(CONFIG_PPC_FPU)) + mathflags |= MSR_FP; + if (IS_ENABLED(CONFIG_ALTIVEC)) + mathflags |= MSR_VEC; + + if (IS_ENABLED(CONFIG_PPC_TRANSACTIONAL_MEM) && + (ti_flags & _TIF_RESTORE_TM)) + restore_tm_state(regs); + else if ((regs->msr & mathflags) != mathflags) + restore_math(regs); + } + + trace_hardirqs_on(); + __hard_EE_RI_disable(); + if (unlikely(lazy_irq_pending())) { + __hard_RI_enable(); + trace_hardirqs_off(); + local_paca->irq_happened |= PACA_IRQ_HARD_DIS; + local_irq_enable(); + local_irq_disable(); + /* Took an interrupt, may have more exit work to do. */ + goto again; + } + local_paca->irq_happened &= ~PACA_IRQ_HARD_DIS; + irq_soft_mask_set(IRQS_ENABLED); + +#ifdef CONFIG_PPC_BOOK3E + if (unlikely(ts->debug.dbcr0 & DBCR0_IDM)) { + /* + * Check to see if the dbcr0 register is set up to debug. + * Use the internal debug mode bit to do this. + */ + mtmsr(mfmsr() & ~MSR_DE); + mtspr(SPRN_DBCR0, ts->debug.dbcr0); + mtspr(SPRN_DBSR, -1); + } +#endif + +#ifdef CONFIG_PPC_TRANSACTIONAL_MEM + local_paca->tm_scratch = regs->msr; +#endif + + kuap_check_amr(); + + account_cpu_user_exit(); + + return ret; +} + +void unrecoverable_exception(struct pt_regs *regs); +void preempt_schedule_irq(void); + +notrace unsigned long interrupt_exit_kernel_prepare(struct pt_regs *regs, unsigned long msr) +{ + unsigned long *ti_flagsp = ¤t_thread_info()->flags; + unsigned long flags; + + if (IS_ENABLED(CONFIG_PPC_BOOK3S) && unlikely(!(regs->msr & MSR_RI))) + unrecoverable_exception(regs); + BUG_ON(regs->msr & MSR_PR); + BUG_ON(!FULL_REGS(regs)); + + local_irq_save(flags); + + if (regs->softe == IRQS_ENABLED) { + /* Returning to a kernel context with local irqs enabled. */ +again: + if (IS_ENABLED(CONFIG_PREEMPT)) { + /* Return to preemptible kernel context */ + if (unlikely(*ti_flagsp & _TIF_NEED_RESCHED)) { + if (preempt_count() == 0) + preempt_schedule_irq(); + } + } + + trace_hardirqs_on(); + __hard_EE_RI_disable(); + if (unlikely(lazy_irq_pending())) { + __hard_RI_enable(); + trace_hardirqs_off(); + local_paca->irq_happened |= PACA_IRQ_HARD_DIS; + local_irq_enable(); + local_irq_disable(); + /* Took an interrupt, may have more exit work to do. */ + goto again; + } + irq_soft_mask_set(IRQS_ENABLED); + } else { + /* Returning to a kernel context with local irqs disabled. */ + trace_hardirqs_on(); + __hard_EE_RI_disable(); + } + + if (regs->msr & MSR_EE) + local_paca->irq_happened &= ~PACA_IRQ_HARD_DIS; + +#ifdef CONFIG_PPC_TRANSACTIONAL_MEM + local_paca->tm_scratch = regs->msr; +#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. + */ + kuap_restore_amr(regs); + + if (unlikely(*ti_flagsp & _TIF_EMULATE_STACK_STORE)) { + clear_bits(_TIF_EMULATE_STACK_STORE, ti_flagsp); + return 1; + } + return 0; +} +#endif diff --git a/arch/powerpc/kernel/vector.S b/arch/powerpc/kernel/vector.S index 8eb867dbad5f..44e7a776e56f 100644 --- a/arch/powerpc/kernel/vector.S +++ b/arch/powerpc/kernel/vector.S @@ -131,7 +131,7 @@ _GLOBAL(load_up_vsx) /* enable use of VSX after return */ oris r12,r12,MSR_VSX@h std r12,_MSR(r1) - b fast_exception_return + b fast_interrupt_return #endif /* CONFIG_VSX */ -- 2.23.0