diff options
Diffstat (limited to 'arch/powerpc/kernel/irq.c')
| -rw-r--r-- | arch/powerpc/kernel/irq.c | 591 |
1 files changed, 49 insertions, 542 deletions
diff --git a/arch/powerpc/kernel/irq.c b/arch/powerpc/kernel/irq.c index c4f1d6b7d992..9ede61a5a469 100644 --- a/arch/powerpc/kernel/irq.c +++ b/arch/powerpc/kernel/irq.c @@ -52,28 +52,21 @@ #include <linux/of_irq.h> #include <linux/vmalloc.h> #include <linux/pgtable.h> +#include <linux/static_call.h> #include <linux/uaccess.h> #include <asm/interrupt.h> #include <asm/io.h> #include <asm/irq.h> #include <asm/cache.h> -#include <asm/prom.h> #include <asm/ptrace.h> #include <asm/machdep.h> #include <asm/udbg.h> #include <asm/smp.h> -#include <asm/livepatch.h> -#include <asm/asm-prototypes.h> #include <asm/hw_irq.h> #include <asm/softirq_stack.h> +#include <asm/ppc_asm.h> -#ifdef CONFIG_PPC64 -#include <asm/paca.h> -#include <asm/firmware.h> -#include <asm/lv1call.h> -#include <asm/dbell.h> -#endif #define CREATE_TRACE_POINTS #include <asm/trace.h> #include <asm/cpu_has_feature.h> @@ -90,488 +83,6 @@ u32 tau_interrupts(unsigned long cpu); #endif #endif /* CONFIG_PPC32 */ -#ifdef CONFIG_PPC64 - -int distribute_irqs = 1; - -static inline notrace unsigned long get_irq_happened(void) -{ - unsigned long happened; - - __asm__ __volatile__("lbz %0,%1(13)" - : "=r" (happened) : "i" (offsetof(struct paca_struct, irq_happened))); - - return happened; -} - -void replay_soft_interrupts(void) -{ - struct pt_regs regs; - - /* - * Be careful here, calling these interrupt handlers can cause - * softirqs to be raised, which they may run when calling irq_exit, - * which will cause local_irq_enable() to be run, which can then - * recurse into this function. Don't keep any state across - * interrupt handler calls which may change underneath us. - * - * We use local_paca rather than get_paca() to avoid all the - * debug_smp_processor_id() business in this low level function. - */ - - ppc_save_regs(®s); - regs.softe = IRQS_ENABLED; - regs.msr |= MSR_EE; - -again: - if (IS_ENABLED(CONFIG_PPC_IRQ_SOFT_MASK_DEBUG)) - WARN_ON_ONCE(mfmsr() & MSR_EE); - - /* - * Force the delivery of pending soft-disabled interrupts on PS3. - * Any HV call will have this side effect. - */ - if (firmware_has_feature(FW_FEATURE_PS3_LV1)) { - u64 tmp, tmp2; - lv1_get_version_info(&tmp, &tmp2); - } - - /* - * Check if an hypervisor Maintenance interrupt happened. - * This is a higher priority interrupt than the others, so - * replay it first. - */ - if (IS_ENABLED(CONFIG_PPC_BOOK3S) && (local_paca->irq_happened & PACA_IRQ_HMI)) { - local_paca->irq_happened &= ~PACA_IRQ_HMI; - regs.trap = INTERRUPT_HMI; - handle_hmi_exception(®s); - if (!(local_paca->irq_happened & PACA_IRQ_HARD_DIS)) - hard_irq_disable(); - } - - if (local_paca->irq_happened & PACA_IRQ_DEC) { - local_paca->irq_happened &= ~PACA_IRQ_DEC; - regs.trap = INTERRUPT_DECREMENTER; - timer_interrupt(®s); - if (!(local_paca->irq_happened & PACA_IRQ_HARD_DIS)) - hard_irq_disable(); - } - - if (local_paca->irq_happened & PACA_IRQ_EE) { - local_paca->irq_happened &= ~PACA_IRQ_EE; - regs.trap = INTERRUPT_EXTERNAL; - do_IRQ(®s); - if (!(local_paca->irq_happened & PACA_IRQ_HARD_DIS)) - hard_irq_disable(); - } - - if (IS_ENABLED(CONFIG_PPC_DOORBELL) && (local_paca->irq_happened & PACA_IRQ_DBELL)) { - local_paca->irq_happened &= ~PACA_IRQ_DBELL; - regs.trap = INTERRUPT_DOORBELL; - doorbell_exception(®s); - if (!(local_paca->irq_happened & PACA_IRQ_HARD_DIS)) - hard_irq_disable(); - } - - /* Book3E does not support soft-masking PMI interrupts */ - if (IS_ENABLED(CONFIG_PPC_BOOK3S) && (local_paca->irq_happened & PACA_IRQ_PMI)) { - local_paca->irq_happened &= ~PACA_IRQ_PMI; - regs.trap = INTERRUPT_PERFMON; - performance_monitor_exception(®s); - if (!(local_paca->irq_happened & PACA_IRQ_HARD_DIS)) - hard_irq_disable(); - } - - if (local_paca->irq_happened & ~PACA_IRQ_HARD_DIS) { - /* - * We are responding to the next interrupt, so interrupt-off - * latencies should be reset here. - */ - trace_hardirqs_on(); - trace_hardirqs_off(); - goto again; - } -} - -#if defined(CONFIG_PPC_BOOK3S_64) && defined(CONFIG_PPC_KUAP) -static inline void replay_soft_interrupts_irqrestore(void) -{ - unsigned long kuap_state = get_kuap(); - - /* - * Check if anything calls local_irq_enable/restore() when KUAP is - * disabled (user access enabled). We handle that case here by saving - * and re-locking AMR but we shouldn't get here in the first place, - * hence the warning. - */ - kuap_assert_locked(); - - if (kuap_state != AMR_KUAP_BLOCKED) - set_kuap(AMR_KUAP_BLOCKED); - - replay_soft_interrupts(); - - if (kuap_state != AMR_KUAP_BLOCKED) - set_kuap(kuap_state); -} -#else -#define replay_soft_interrupts_irqrestore() replay_soft_interrupts() -#endif - -#ifdef CONFIG_CC_HAS_ASM_GOTO -notrace void arch_local_irq_restore(unsigned long mask) -{ - unsigned char irq_happened; - - /* Write the new soft-enabled value if it is a disable */ - if (mask) { - irq_soft_mask_set(mask); - return; - } - - if (IS_ENABLED(CONFIG_PPC_IRQ_SOFT_MASK_DEBUG)) - WARN_ON_ONCE(in_nmi() || in_hardirq()); - - /* - * After the stb, interrupts are unmasked and there are no interrupts - * pending replay. The restart sequence makes this atomic with - * respect to soft-masked interrupts. If this was just a simple code - * sequence, a soft-masked interrupt could become pending right after - * the comparison and before the stb. - * - * This allows interrupts to be unmasked without hard disabling, and - * also without new hard interrupts coming in ahead of pending ones. - */ - asm_volatile_goto( -"1: \n" -" lbz 9,%0(13) \n" -" cmpwi 9,0 \n" -" bne %l[happened] \n" -" stb 9,%1(13) \n" -"2: \n" - RESTART_TABLE(1b, 2b, 1b) - : : "i" (offsetof(struct paca_struct, irq_happened)), - "i" (offsetof(struct paca_struct, irq_soft_mask)) - : "cr0", "r9" - : happened); - - if (IS_ENABLED(CONFIG_PPC_IRQ_SOFT_MASK_DEBUG)) - WARN_ON_ONCE(!(mfmsr() & MSR_EE)); - - return; - -happened: - irq_happened = get_irq_happened(); - if (IS_ENABLED(CONFIG_PPC_IRQ_SOFT_MASK_DEBUG)) - WARN_ON_ONCE(!irq_happened); - - if (irq_happened == PACA_IRQ_HARD_DIS) { - if (IS_ENABLED(CONFIG_PPC_IRQ_SOFT_MASK_DEBUG)) - WARN_ON_ONCE(mfmsr() & MSR_EE); - irq_soft_mask_set(IRQS_ENABLED); - local_paca->irq_happened = 0; - __hard_irq_enable(); - return; - } - - /* Have interrupts to replay, need to hard disable first */ - if (!(irq_happened & PACA_IRQ_HARD_DIS)) { - if (IS_ENABLED(CONFIG_PPC_IRQ_SOFT_MASK_DEBUG)) { - if (!(mfmsr() & MSR_EE)) { - /* - * An interrupt could have come in and cleared - * MSR[EE] and set IRQ_HARD_DIS, so check - * IRQ_HARD_DIS again and warn if it is still - * clear. - */ - irq_happened = get_irq_happened(); - WARN_ON_ONCE(!(irq_happened & PACA_IRQ_HARD_DIS)); - } - } - __hard_irq_disable(); - local_paca->irq_happened |= PACA_IRQ_HARD_DIS; - } else { - if (IS_ENABLED(CONFIG_PPC_IRQ_SOFT_MASK_DEBUG)) { - if (WARN_ON_ONCE(mfmsr() & MSR_EE)) - __hard_irq_disable(); - } - } - - /* - * Disable preempt here, so that the below preempt_enable will - * perform resched if required (a replayed interrupt may set - * need_resched). - */ - preempt_disable(); - irq_soft_mask_set(IRQS_ALL_DISABLED); - trace_hardirqs_off(); - - replay_soft_interrupts_irqrestore(); - local_paca->irq_happened = 0; - - trace_hardirqs_on(); - irq_soft_mask_set(IRQS_ENABLED); - __hard_irq_enable(); - preempt_enable(); -} -#else -notrace void arch_local_irq_restore(unsigned long mask) -{ - unsigned char irq_happened; - - /* Write the new soft-enabled value */ - irq_soft_mask_set(mask); - if (mask) - return; - - if (IS_ENABLED(CONFIG_PPC_IRQ_SOFT_MASK_DEBUG)) - WARN_ON_ONCE(in_nmi() || in_hardirq()); - - /* - * From this point onward, we can take interrupts, preempt, - * etc... unless we got hard-disabled. We check if an event - * happened. If none happened, we know we can just return. - * - * We may have preempted before the check below, in which case - * we are checking the "new" CPU instead of the old one. This - * is only a problem if an event happened on the "old" CPU. - * - * External interrupt events will have caused interrupts to - * be hard-disabled, so there is no problem, we - * cannot have preempted. - */ - irq_happened = get_irq_happened(); - if (!irq_happened) { - if (IS_ENABLED(CONFIG_PPC_IRQ_SOFT_MASK_DEBUG)) - WARN_ON_ONCE(!(mfmsr() & MSR_EE)); - return; - } - - /* We need to hard disable to replay. */ - if (!(irq_happened & PACA_IRQ_HARD_DIS)) { - if (IS_ENABLED(CONFIG_PPC_IRQ_SOFT_MASK_DEBUG)) - WARN_ON_ONCE(!(mfmsr() & MSR_EE)); - __hard_irq_disable(); - local_paca->irq_happened |= PACA_IRQ_HARD_DIS; - } else { - /* - * We should already be hard disabled here. We had bugs - * where that wasn't the case so let's dbl check it and - * warn if we are wrong. Only do that when IRQ tracing - * is enabled as mfmsr() can be costly. - */ - if (IS_ENABLED(CONFIG_PPC_IRQ_SOFT_MASK_DEBUG)) { - if (WARN_ON_ONCE(mfmsr() & MSR_EE)) - __hard_irq_disable(); - } - - if (irq_happened == PACA_IRQ_HARD_DIS) { - local_paca->irq_happened = 0; - __hard_irq_enable(); - return; - } - } - - /* - * Disable preempt here, so that the below preempt_enable will - * perform resched if required (a replayed interrupt may set - * need_resched). - */ - preempt_disable(); - irq_soft_mask_set(IRQS_ALL_DISABLED); - trace_hardirqs_off(); - - replay_soft_interrupts_irqrestore(); - local_paca->irq_happened = 0; - - trace_hardirqs_on(); - irq_soft_mask_set(IRQS_ENABLED); - __hard_irq_enable(); - preempt_enable(); -} -#endif -EXPORT_SYMBOL(arch_local_irq_restore); - -/* - * This is a helper to use when about to go into idle low-power - * when the latter has the side effect of re-enabling interrupts - * (such as calling H_CEDE under pHyp). - * - * You call this function with interrupts soft-disabled (this is - * already the case when ppc_md.power_save is called). The function - * will return whether to enter power save or just return. - * - * In the former case, it will have notified lockdep of interrupts - * being re-enabled and generally sanitized the lazy irq state, - * and in the latter case it will leave with interrupts hard - * disabled and marked as such, so the local_irq_enable() call - * in arch_cpu_idle() will properly re-enable everything. - */ -bool prep_irq_for_idle(void) -{ - /* - * First we need to hard disable to ensure no interrupt - * occurs before we effectively enter the low power state - */ - __hard_irq_disable(); - local_paca->irq_happened |= PACA_IRQ_HARD_DIS; - - /* - * If anything happened while we were soft-disabled, - * we return now and do not enter the low power state. - */ - if (lazy_irq_pending()) - return false; - - /* Tell lockdep we are about to re-enable */ - trace_hardirqs_on(); - - /* - * Mark interrupts as soft-enabled and clear the - * PACA_IRQ_HARD_DIS from the pending mask since we - * are about to hard enable as well as a side effect - * of entering the low power state. - */ - local_paca->irq_happened &= ~PACA_IRQ_HARD_DIS; - irq_soft_mask_set(IRQS_ENABLED); - - /* Tell the caller to enter the low power state */ - return true; -} - -#ifdef CONFIG_PPC_BOOK3S -/* - * This is for idle sequences that return with IRQs off, but the - * idle state itself wakes on interrupt. Tell the irq tracer that - * IRQs are enabled for the duration of idle so it does not get long - * off times. Must be paired with fini_irq_for_idle_irqsoff. - */ -bool prep_irq_for_idle_irqsoff(void) -{ - WARN_ON(!irqs_disabled()); - - /* - * First we need to hard disable to ensure no interrupt - * occurs before we effectively enter the low power state - */ - __hard_irq_disable(); - local_paca->irq_happened |= PACA_IRQ_HARD_DIS; - - /* - * If anything happened while we were soft-disabled, - * we return now and do not enter the low power state. - */ - if (lazy_irq_pending()) - return false; - - /* Tell lockdep we are about to re-enable */ - trace_hardirqs_on(); - - return true; -} - -/* - * Take the SRR1 wakeup reason, index into this table to find the - * appropriate irq_happened bit. - * - * Sytem reset exceptions taken in idle state also come through here, - * but they are NMI interrupts so do not need to wait for IRQs to be - * restored, and should be taken as early as practical. These are marked - * with 0xff in the table. The Power ISA specifies 0100b as the system - * reset interrupt reason. - */ -#define IRQ_SYSTEM_RESET 0xff - -static const u8 srr1_to_lazyirq[0x10] = { - 0, 0, 0, - PACA_IRQ_DBELL, - IRQ_SYSTEM_RESET, - PACA_IRQ_DBELL, - PACA_IRQ_DEC, - 0, - PACA_IRQ_EE, - PACA_IRQ_EE, - PACA_IRQ_HMI, - 0, 0, 0, 0, 0 }; - -void replay_system_reset(void) -{ - struct pt_regs regs; - - ppc_save_regs(®s); - regs.trap = 0x100; - get_paca()->in_nmi = 1; - system_reset_exception(®s); - get_paca()->in_nmi = 0; -} -EXPORT_SYMBOL_GPL(replay_system_reset); - -void irq_set_pending_from_srr1(unsigned long srr1) -{ - unsigned int idx = (srr1 & SRR1_WAKEMASK_P8) >> 18; - u8 reason = srr1_to_lazyirq[idx]; - - /* - * Take the system reset now, which is immediately after registers - * are restored from idle. It's an NMI, so interrupts need not be - * re-enabled before it is taken. - */ - if (unlikely(reason == IRQ_SYSTEM_RESET)) { - replay_system_reset(); - return; - } - - if (reason == PACA_IRQ_DBELL) { - /* - * When doorbell triggers a system reset wakeup, the message - * is not cleared, so if the doorbell interrupt is replayed - * and the IPI handled, the doorbell interrupt would still - * fire when EE is enabled. - * - * To avoid taking the superfluous doorbell interrupt, - * execute a msgclr here before the interrupt is replayed. - */ - ppc_msgclr(PPC_DBELL_MSGTYPE); - } - - /* - * The 0 index (SRR1[42:45]=b0000) must always evaluate to 0, - * so this can be called unconditionally with the SRR1 wake - * reason as returned by the idle code, which uses 0 to mean no - * interrupt. - * - * If a future CPU was to designate this as an interrupt reason, - * then a new index for no interrupt must be assigned. - */ - local_paca->irq_happened |= reason; -} -#endif /* CONFIG_PPC_BOOK3S */ - -/* - * Force a replay of the external interrupt handler on this CPU. - */ -void force_external_irq_replay(void) -{ - /* - * This must only be called with interrupts soft-disabled, - * the replay will happen when re-enabling. - */ - WARN_ON(!arch_irqs_disabled()); - - /* - * Interrupts must always be hard disabled before irq_happened is - * modified (to prevent lost update in case of interrupt between - * load and store). - */ - __hard_irq_disable(); - local_paca->irq_happened |= PACA_IRQ_HARD_DIS; - - /* Indicate in the PACA that we have an interrupt to replay */ - local_paca->irq_happened |= PACA_IRQ_EE; -} - -#endif /* CONFIG_PPC64 */ - int arch_show_interrupts(struct seq_file *p, int prec) { int j; @@ -674,22 +185,21 @@ u64 arch_irq_stat_cpu(unsigned int cpu) return sum; } -static inline void check_stack_overflow(void) +static inline void check_stack_overflow(unsigned long sp) { - long sp; - if (!IS_ENABLED(CONFIG_DEBUG_STACKOVERFLOW)) return; - sp = current_stack_pointer & (THREAD_SIZE - 1); + sp &= THREAD_SIZE - 1; - /* check for stack overflow: is there less than 2KB free? */ - if (unlikely(sp < 2048)) { + /* check for stack overflow: is there less than 1/4th free? */ + if (unlikely(sp < THREAD_SIZE / 4)) { pr_err("do_IRQ: stack overflow: %ld\n", sp); dump_stack(); } } +#ifdef CONFIG_SOFTIRQ_ON_OWN_STACK static __always_inline void call_do_softirq(const void *sp) { /* Temporarily switch r1 to sp, call __do_softirq() then restore r1. */ @@ -708,44 +218,28 @@ static __always_inline void call_do_softirq(const void *sp) "r11", "r12" ); } +#endif -static __always_inline void call_do_irq(struct pt_regs *regs, void *sp) -{ - register unsigned long r3 asm("r3") = (unsigned long)regs; - - /* Temporarily switch r1 to sp, call __do_irq() then restore r1. */ - asm volatile ( - PPC_STLU " %%r1, %[offset](%[sp]) ;" - "mr %%r1, %[sp] ;" - "bl %[callee] ;" - PPC_LL " %%r1, 0(%%r1) ;" - : // Outputs - "+r" (r3) - : // Inputs - [sp] "b" (sp), [offset] "i" (THREAD_SIZE - STACK_FRAME_OVERHEAD), - [callee] "i" (__do_irq) - : // Clobbers - "lr", "xer", "ctr", "memory", "cr0", "cr1", "cr5", "cr6", - "cr7", "r0", "r4", "r5", "r6", "r7", "r8", "r9", "r10", - "r11", "r12" - ); -} +DEFINE_STATIC_CALL_RET0(ppc_get_irq, *ppc_md.get_irq); -void __do_irq(struct pt_regs *regs) +static void __do_irq(struct pt_regs *regs, unsigned long oldsp) { unsigned int irq; trace_irq_entry(regs); + check_stack_overflow(oldsp); + /* * Query the platform PIC for the interrupt & ack it. * * This will typically lower the interrupt line to the CPU */ - irq = ppc_md.get_irq(); + irq = static_call(ppc_get_irq)(); /* We can hard enable interrupts now to allow perf interrupts */ - may_hard_irq_enable(); + if (should_hard_irq_enable()) + do_hard_irq_enable(); /* And finally process it */ if (unlikely(!irq)) @@ -756,6 +250,29 @@ void __do_irq(struct pt_regs *regs) trace_irq_exit(regs); } +static __always_inline void call_do_irq(struct pt_regs *regs, void *sp) +{ + register unsigned long r3 asm("r3") = (unsigned long)regs; + + /* Temporarily switch r1 to sp, call __do_irq() then restore r1. */ + asm volatile ( + PPC_STLU " %%r1, %[offset](%[sp]) ;" + "mr %%r4, %%r1 ;" + "mr %%r1, %[sp] ;" + "bl %[callee] ;" + PPC_LL " %%r1, 0(%%r1) ;" + : // Outputs + "+r" (r3) + : // Inputs + [sp] "b" (sp), [offset] "i" (THREAD_SIZE - STACK_FRAME_OVERHEAD), + [callee] "i" (__do_irq) + : // Clobbers + "lr", "xer", "ctr", "memory", "cr0", "cr1", "cr5", "cr6", + "cr7", "r0", "r4", "r5", "r6", "r7", "r8", "r9", "r10", + "r11", "r12" + ); +} + void __do_IRQ(struct pt_regs *regs) { struct pt_regs *old_regs = set_irq_regs(regs); @@ -766,16 +283,11 @@ void __do_IRQ(struct pt_regs *regs) irqsp = hardirq_ctx[raw_smp_processor_id()]; sirqsp = softirq_ctx[raw_smp_processor_id()]; - check_stack_overflow(); - - /* Already there ? */ - if (unlikely(cursp == irqsp || cursp == sirqsp)) { - __do_irq(regs); - set_irq_regs(old_regs); - return; - } - /* Switch stack and call */ - call_do_irq(regs, irqsp); + /* Already there ? If not switch stack and call */ + if (unlikely(cursp == irqsp || cursp == sirqsp)) + __do_irq(regs, current_stack_pointer); + else + call_do_irq(regs, irqsp); set_irq_regs(old_regs); } @@ -809,9 +321,12 @@ void __init init_IRQ(void) if (ppc_md.init_IRQ) ppc_md.init_IRQ(); + + if (!WARN_ON(!ppc_md.get_irq)) + static_call_update(ppc_get_irq, ppc_md.get_irq); } -#if defined(CONFIG_BOOKE) || defined(CONFIG_40x) +#ifdef CONFIG_BOOKE_OR_40x void *critirq_ctx[NR_CPUS] __read_mostly; void *dbgirq_ctx[NR_CPUS] __read_mostly; void *mcheckirq_ctx[NR_CPUS] __read_mostly; @@ -820,10 +335,12 @@ void *mcheckirq_ctx[NR_CPUS] __read_mostly; void *softirq_ctx[NR_CPUS] __read_mostly; void *hardirq_ctx[NR_CPUS] __read_mostly; +#ifdef CONFIG_SOFTIRQ_ON_OWN_STACK void do_softirq_own_stack(void) { call_do_softirq(softirq_ctx[smp_processor_id()]); } +#endif irq_hw_number_t virq_to_hw(unsigned int virq) { @@ -867,13 +384,3 @@ int irq_choose_cpu(const struct cpumask *mask) return hard_smp_processor_id(); } #endif - -#ifdef CONFIG_PPC64 -static int __init setup_noirqdistrib(char *str) -{ - distribute_irqs = 0; - return 1; -} - -__setup("noirqdistrib", setup_noirqdistrib); -#endif /* CONFIG_PPC64 */ |