From 118178e62e2e0da39b394e812fef7179c8bdb3bc Mon Sep 17 00:00:00 2001 From: Nicholas Piggin Date: Sat, 30 Jan 2021 23:08:49 +1000 Subject: [PATCH] powerpc: move NMI entry/exit code into wrapper This moves the common NMI entry and exit code into the interrupt handler wrappers. This changes the behaviour of soft-NMI (watchdog) and HMI interrupts, and also MCE interrupts on 64e, by adding missing parts of the NMI entry to them. Signed-off-by: Nicholas Piggin Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20210130130852.2952424-40-npiggin@gmail.com --- arch/powerpc/include/asm/interrupt.h | 28 ++++++++++++++++++++++++++++ arch/powerpc/kernel/mce.c | 11 ----------- arch/powerpc/kernel/traps.c | 35 ++++++----------------------------- arch/powerpc/kernel/watchdog.c | 10 ++++------ 4 files changed, 38 insertions(+), 46 deletions(-) diff --git a/arch/powerpc/include/asm/interrupt.h b/arch/powerpc/include/asm/interrupt.h index ca8e08b..cd819d4 100644 --- a/arch/powerpc/include/asm/interrupt.h +++ b/arch/powerpc/include/asm/interrupt.h @@ -94,14 +94,42 @@ static inline void interrupt_async_exit_prepare(struct pt_regs *regs, struct int } struct interrupt_nmi_state { +#ifdef CONFIG_PPC64 + u8 ftrace_enabled; +#endif }; static inline void interrupt_nmi_enter_prepare(struct pt_regs *regs, struct interrupt_nmi_state *state) { +#ifdef CONFIG_PPC64 + /* Allow DEC and PMI to be traced when they are soft-NMI */ + if (TRAP(regs) != 0x900 && TRAP(regs) != 0xf00 && TRAP(regs) != 0x260) { + state->ftrace_enabled = this_cpu_get_ftrace_enabled(); + this_cpu_set_ftrace_enabled(0); + } +#endif + + /* + * Do not use nmi_enter() for pseries hash guest taking a real-mode + * NMI because not everything it touches is within the RMA limit. + */ + if (!IS_ENABLED(CONFIG_PPC_BOOK3S_64) || + !firmware_has_feature(FW_FEATURE_LPAR) || + radix_enabled() || (mfmsr() & MSR_DR)) + nmi_enter(); } static inline void interrupt_nmi_exit_prepare(struct pt_regs *regs, struct interrupt_nmi_state *state) { + if (!IS_ENABLED(CONFIG_PPC_BOOK3S_64) || + !firmware_has_feature(FW_FEATURE_LPAR) || + radix_enabled() || (mfmsr() & MSR_DR)) + nmi_exit(); + +#ifdef CONFIG_PPC64 + if (TRAP(regs) != 0x900 && TRAP(regs) != 0xf00 && TRAP(regs) != 0x260) + this_cpu_set_ftrace_enabled(state->ftrace_enabled); +#endif } /** diff --git a/arch/powerpc/kernel/mce.c b/arch/powerpc/kernel/mce.c index cfe96cd..11f0cae 100644 --- a/arch/powerpc/kernel/mce.c +++ b/arch/powerpc/kernel/mce.c @@ -587,12 +587,6 @@ EXPORT_SYMBOL_GPL(machine_check_print_event_info); DEFINE_INTERRUPT_HANDLER_NMI(machine_check_early) { long handled = 0; - u8 ftrace_enabled = this_cpu_get_ftrace_enabled(); - - this_cpu_set_ftrace_enabled(0); - /* Do not use nmi_enter/exit for pseries hpte guest */ - if (radix_enabled() || !firmware_has_feature(FW_FEATURE_LPAR)) - nmi_enter(); hv_nmi_check_nonrecoverable(regs); @@ -602,11 +596,6 @@ DEFINE_INTERRUPT_HANDLER_NMI(machine_check_early) if (ppc_md.machine_check_early) handled = ppc_md.machine_check_early(regs); - if (radix_enabled() || !firmware_has_feature(FW_FEATURE_LPAR)) - nmi_exit(); - - this_cpu_set_ftrace_enabled(ftrace_enabled); - return handled; } diff --git a/arch/powerpc/kernel/traps.c b/arch/powerpc/kernel/traps.c index 13fb93a..39c8b7e 100644 --- a/arch/powerpc/kernel/traps.c +++ b/arch/powerpc/kernel/traps.c @@ -435,11 +435,6 @@ DEFINE_INTERRUPT_HANDLER_NMI(system_reset_exception) { unsigned long hsrr0, hsrr1; bool saved_hsrrs = false; - u8 ftrace_enabled = this_cpu_get_ftrace_enabled(); - - this_cpu_set_ftrace_enabled(0); - - nmi_enter(); /* * System reset can interrupt code where HSRRs are live and MSR[RI]=1. @@ -514,10 +509,6 @@ out: mtspr(SPRN_HSRR1, hsrr1); } - nmi_exit(); - - this_cpu_set_ftrace_enabled(ftrace_enabled); - /* What should we do here? We could issue a shutdown or hard reset. */ return 0; @@ -809,6 +800,12 @@ void die_mce(const char *str, struct pt_regs *regs, long err) } NOKPROBE_SYMBOL(die_mce); +/* + * BOOK3S_64 does not call this handler as a non-maskable interrupt + * (it uses its own early real-mode handler to handle the MCE proper + * and then raises irq_work to call this handler when interrupts are + * enabled). + */ #ifdef CONFIG_PPC_BOOK3S_64 DEFINE_INTERRUPT_HANDLER_ASYNC(machine_check_exception) #else @@ -817,20 +814,6 @@ DEFINE_INTERRUPT_HANDLER_NMI(machine_check_exception) { int recover = 0; - /* - * BOOK3S_64 does not call this handler as a non-maskable interrupt - * (it uses its own early real-mode handler to handle the MCE proper - * and then raises irq_work to call this handler when interrupts are - * enabled). - * - * This is silly. The BOOK3S_64 should just call a different function - * rather than expecting semantics to magically change. Something - * like 'non_nmi_machine_check_exception()', perhaps? - */ - const bool nmi = !IS_ENABLED(CONFIG_PPC_BOOK3S_64); - - if (nmi) nmi_enter(); - __this_cpu_inc(irq_stat.mce_exceptions); add_taint(TAINT_MACHINE_CHECK, LOCKDEP_NOW_UNRELIABLE); @@ -862,8 +845,6 @@ bail: if (!(regs->msr & MSR_RI)) die_mce("Unrecoverable Machine check", regs, SIGBUS); - if (nmi) nmi_exit(); - #ifdef CONFIG_PPC_BOOK3S_64 return; #else @@ -1892,14 +1873,10 @@ DEFINE_INTERRUPT_HANDLER(vsx_unavailable_tm) DECLARE_INTERRUPT_HANDLER_NMI(performance_monitor_exception_nmi); DEFINE_INTERRUPT_HANDLER_NMI(performance_monitor_exception_nmi) { - nmi_enter(); - __this_cpu_inc(irq_stat.pmu_irqs); perf_irq(regs); - nmi_exit(); - return 0; } #endif diff --git a/arch/powerpc/kernel/watchdog.c b/arch/powerpc/kernel/watchdog.c index be6b228..c9a8f47 100644 --- a/arch/powerpc/kernel/watchdog.c +++ b/arch/powerpc/kernel/watchdog.c @@ -255,11 +255,12 @@ DEFINE_INTERRUPT_HANDLER_NMI(soft_nmi_interrupt) int cpu = raw_smp_processor_id(); u64 tb; + /* should only arrive from kernel, with irqs disabled */ + WARN_ON_ONCE(!arch_irq_disabled_regs(regs)); + if (!cpumask_test_cpu(cpu, &wd_cpus_enabled)) return 0; - nmi_enter(); - __this_cpu_inc(irq_stat.soft_nmi_irqs); tb = get_tb(); @@ -267,7 +268,7 @@ DEFINE_INTERRUPT_HANDLER_NMI(soft_nmi_interrupt) wd_smp_lock(&flags); if (cpumask_test_cpu(cpu, &wd_smp_cpus_stuck)) { wd_smp_unlock(&flags); - goto out; + return 0; } set_cpu_stuck(cpu, tb); @@ -291,9 +292,6 @@ DEFINE_INTERRUPT_HANDLER_NMI(soft_nmi_interrupt) if (wd_panic_timeout_tb < 0x7fffffff) mtspr(SPRN_DEC, wd_panic_timeout_tb); -out: - nmi_exit(); - return 0; } -- 2.7.4