Similarly to the system call change in the previous patch, the mtmsrd to enable RI can be combined with the mtmsrd to enable EE for interrupts which enable the latter, which tends to be the important synchronous interrupts (i.e., page faults).
Do this by enabling EE and RI together at the beginning of the entry wrapper if PACA_IRQ_HARD_DIS is clear, and just enabling RI if it is set (which means something wanted EE=0). Asynchronous interrupts set PACA_IRQ_HARD_DIS, but synchronous ones leave it unchanged, so by default they always get EE=1 unless they interrupt a caller that has hard disabled. When the sync interrupt later calls interrupt_cond_local_irq_enable(), that will not require another mtmsrd because we already enabled here. This tends to save one mtmsrd L=1 for synchronous interrupts on 64s. 64e is conceptually unchanged, but it also sets MSR[EE]=1 now in the interrupt wrapper for synchronous interrupts with the same code. From: Nicholas Piggin <npig...@gmail.com> --- arch/powerpc/include/asm/interrupt.h | 18 +++++++++++++++-- arch/powerpc/kernel/exceptions-64s.S | 30 ---------------------------- 2 files changed, 16 insertions(+), 32 deletions(-) diff --git a/arch/powerpc/include/asm/interrupt.h b/arch/powerpc/include/asm/interrupt.h index 8796eb4630c9..d6d54bbcba2f 100644 --- a/arch/powerpc/include/asm/interrupt.h +++ b/arch/powerpc/include/asm/interrupt.h @@ -55,9 +55,20 @@ static inline void interrupt_enter_prepare(struct pt_regs *regs, struct interrup #endif #ifdef CONFIG_PPC64 - if (irq_soft_mask_set_return(IRQS_ALL_DISABLED) == IRQS_ENABLED) + bool trace_enable = false; + + if (IS_ENABLED(CONFIG_TRACE_IRQFLAGS)) { + if (irq_soft_mask_set_return(IRQS_DISABLED) == IRQS_ENABLED) + trace_enable = true; + } else { + irq_soft_mask_set(IRQS_DISABLED); + } + if (local_paca->irq_happened & PACA_IRQ_HARD_DIS) + __hard_RI_enable(); + else + __hard_irq_enable(); + if (trace_enable) trace_hardirqs_off(); - local_paca->irq_happened |= PACA_IRQ_HARD_DIS; if (user_mode(regs)) { CT_WARN_ON(ct_state() != CONTEXT_USER); @@ -110,6 +121,7 @@ static inline void interrupt_async_enter_prepare(struct pt_regs *regs, struct in __ppc64_runlatch_on(); #endif + local_paca->irq_happened |= PACA_IRQ_HARD_DIS; interrupt_enter_prepare(regs, state); irq_enter(); } @@ -166,6 +178,8 @@ static inline void interrupt_nmi_enter_prepare(struct pt_regs *regs, struct inte local_paca->irq_soft_mask = IRQS_ALL_DISABLED; local_paca->irq_happened |= PACA_IRQ_HARD_DIS; + __hard_RI_enable(); + /* Don't do any per-CPU operations until interrupt state is fixed */ if (nmi_disables_ftrace(regs)) { diff --git a/arch/powerpc/kernel/exceptions-64s.S b/arch/powerpc/kernel/exceptions-64s.S index 2f14ac3c377c..75cee7cdf887 100644 --- a/arch/powerpc/kernel/exceptions-64s.S +++ b/arch/powerpc/kernel/exceptions-64s.S @@ -129,7 +129,6 @@ name: #define IISIDE .L_IISIDE_\name\() /* Uses SRR0/1 not DAR/DSISR */ #define IDAR .L_IDAR_\name\() /* Uses DAR (or SRR0) */ #define IDSISR .L_IDSISR_\name\() /* Uses DSISR (or SRR1) */ -#define ISET_RI .L_ISET_RI_\name\() /* Run common code w/ MSR[RI]=1 */ #define IBRANCH_TO_COMMON .L_IBRANCH_TO_COMMON_\name\() /* ENTRY branch to common */ #define IREALMODE_COMMON .L_IREALMODE_COMMON_\name\() /* Common runs in realmode */ #define IMASK .L_IMASK_\name\() /* IRQ soft-mask bit */ @@ -174,9 +173,6 @@ do_define_int n .ifndef IDSISR IDSISR=0 .endif - .ifndef ISET_RI - ISET_RI=1 - .endif .ifndef IBRANCH_TO_COMMON IBRANCH_TO_COMMON=1 .endif @@ -582,11 +578,6 @@ DEFINE_FIXED_SYMBOL(\name\()_common_real) stb r10,PACASRR_VALID(r13) .endif - .if ISET_RI - li r10,MSR_RI - mtmsrd r10,1 /* Set MSR_RI */ - .endif - .if ISTACK .if IKUAP kuap_save_amr_and_lock r9, r10, cr1, cr0 @@ -931,11 +922,6 @@ INT_DEFINE_BEGIN(system_reset) IVEC=0x100 IAREA=PACA_EXNMI IVIRT=0 /* no virt entry point */ - /* - * MSR_RI is not enabled, because PACA_EXNMI and nmi stack is - * being used, so a nested NMI exception would corrupt it. - */ - ISET_RI=0 ISTACK=0 IKVM_REAL=1 INT_DEFINE_END(system_reset) @@ -1016,8 +1002,6 @@ EXC_COMMON_BEGIN(system_reset_common) lhz r10,PACA_IN_NMI(r13) addi r10,r10,1 sth r10,PACA_IN_NMI(r13) - li r10,MSR_RI - mtmsrd r10,1 mr r10,r1 ld r1,PACA_NMI_EMERG_SP(r13) @@ -1095,12 +1079,6 @@ INT_DEFINE_BEGIN(machine_check_early) IAREA=PACA_EXMC IVIRT=0 /* no virt entry point */ IREALMODE_COMMON=1 - /* - * MSR_RI is not enabled, because PACA_EXMC is being used, so a - * nested machine check corrupts it. machine_check_common enables - * MSR_RI. - */ - ISET_RI=0 ISTACK=0 IDAR=1 IDSISR=1 @@ -1111,7 +1089,6 @@ INT_DEFINE_BEGIN(machine_check) IVEC=0x200 IAREA=PACA_EXMC IVIRT=0 /* no virt entry point */ - ISET_RI=0 IDAR=1 IDSISR=1 IKVM_SKIP=1 @@ -1182,9 +1159,6 @@ EXC_COMMON_BEGIN(machine_check_early_common) BEGIN_FTR_SECTION bl enable_machine_check END_FTR_SECTION_IFSET(CPU_FTR_HVMODE) - li r10,MSR_RI - mtmsrd r10,1 - addi r3,r1,STACK_FRAME_OVERHEAD bl machine_check_early std r3,RESULT(r1) /* Save result */ @@ -1272,10 +1246,6 @@ EXC_COMMON_BEGIN(machine_check_common) * save area: PACA_EXMC instead of PACA_EXGEN. */ GEN_COMMON machine_check - - /* Enable MSR_RI when finished with PACA_EXMC */ - li r10,MSR_RI - mtmsrd r10,1 addi r3,r1,STACK_FRAME_OVERHEAD bl machine_check_exception b interrupt_return_srr -- 2.23.0