diff options
Diffstat (limited to 'arch/powerpc/kernel/irq.c')
| -rw-r--r-- | arch/powerpc/kernel/irq.c | 570 |
1 files changed, 113 insertions, 457 deletions
diff --git a/arch/powerpc/kernel/irq.c b/arch/powerpc/kernel/irq.c index 5645bc9cbc09..6f7d4edaa0bc 100644 --- a/arch/powerpc/kernel/irq.c +++ b/arch/powerpc/kernel/irq.c @@ -50,26 +50,23 @@ #include <linux/debugfs.h> #include <linux/of.h> #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/pgtable.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> -#endif #define CREATE_TRACE_POINTS #include <asm/trace.h> #include <asm/cpu_has_feature.h> @@ -86,417 +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; -} - -static inline notrace int decrementer_check_overflow(void) -{ - u64 now = get_tb_or_rtc(); - u64 *next_tb = this_cpu_ptr(&decrementers_next_tb); - - return now >= *next_tb; -} - -/* This is called whenever we are re-enabling interrupts - * and returns either 0 (nothing to do) or 500/900/280/a00/e80 if - * there's an EE, DEC or DBELL to generate. - * - * This is called in two contexts: From arch_local_irq_restore() - * before soft-enabling interrupts, and from the exception exit - * path when returning from an interrupt from a soft-disabled to - * a soft enabled context. In both case we have interrupts hard - * disabled. - * - * We take care of only clearing the bits we handled in the - * PACA irq_happened field since we can only re-emit one at a - * time and we don't want to "lose" one. - */ -notrace unsigned int __check_irq_replay(void) -{ - /* - * We use local_paca rather than get_paca() to avoid all - * the debug_smp_processor_id() business in this low level - * function - */ - unsigned char happened = local_paca->irq_happened; - - /* - * We are responding to the next interrupt, so interrupt-off - * latencies should be reset here. - */ - trace_hardirqs_on(); - trace_hardirqs_off(); - - /* - * We are always hard disabled here, but PACA_IRQ_HARD_DIS may - * not be set, which means interrupts have only just been hard - * disabled as part of the local_irq_restore or interrupt return - * code. In that case, skip the decrementr check becaus it's - * expensive to read the TB. - * - * HARD_DIS then gets cleared here, but it's reconciled later. - * Either local_irq_disable will replay the interrupt and that - * will reconcile state like other hard interrupts. Or interrupt - * retur will replay the interrupt and in that case it sets - * PACA_IRQ_HARD_DIS by hand (see comments in entry_64.S). - */ - if (happened & PACA_IRQ_HARD_DIS) { - local_paca->irq_happened &= ~PACA_IRQ_HARD_DIS; - - /* - * We may have missed a decrementer interrupt if hard disabled. - * Check the decrementer register in case we had a rollover - * while hard disabled. - */ - if (!(happened & PACA_IRQ_DEC)) { - if (decrementer_check_overflow()) { - local_paca->irq_happened |= PACA_IRQ_DEC; - happened |= PACA_IRQ_DEC; - } - } - } - - /* - * 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 (happened & PACA_IRQ_HMI) { - local_paca->irq_happened &= ~PACA_IRQ_HMI; - return 0xe60; - } - - if (happened & PACA_IRQ_DEC) { - local_paca->irq_happened &= ~PACA_IRQ_DEC; - return 0x900; - } - - if (happened & PACA_IRQ_PMI) { - local_paca->irq_happened &= ~PACA_IRQ_PMI; - return 0xf00; - } - - if (happened & PACA_IRQ_EE) { - local_paca->irq_happened &= ~PACA_IRQ_EE; - return 0x500; - } - -#ifdef CONFIG_PPC_BOOK3E - /* - * Check if an EPR external interrupt happened this bit is typically - * set if we need to handle another "edge" interrupt from within the - * MPIC "EPR" handler. - */ - if (happened & PACA_IRQ_EE_EDGE) { - local_paca->irq_happened &= ~PACA_IRQ_EE_EDGE; - return 0x500; - } - - if (happened & PACA_IRQ_DBELL) { - local_paca->irq_happened &= ~PACA_IRQ_DBELL; - return 0x280; - } -#else - if (happened & PACA_IRQ_DBELL) { - local_paca->irq_happened &= ~PACA_IRQ_DBELL; - return 0xa00; - } -#endif /* CONFIG_PPC_BOOK3E */ - - /* There should be nothing left ! */ - BUG_ON(local_paca->irq_happened != 0); - - return 0; -} - -notrace void arch_local_irq_restore(unsigned long mask) -{ - unsigned char irq_happened; - unsigned int replay; - - /* Write the new soft-enabled value */ - irq_soft_mask_set(mask); - if (mask) - return; - - /* - * 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) { -#ifdef CONFIG_PPC_IRQ_SOFT_MASK_DEBUG - WARN_ON_ONCE(!(mfmsr() & MSR_EE)); -#endif - return; - } - - /* - * We need to hard disable to get a trusted value from - * __check_irq_replay(). We also need to soft-disable - * again to avoid warnings in there due to the use of - * per-cpu variables. - */ - if (!(irq_happened & PACA_IRQ_HARD_DIS)) { -#ifdef CONFIG_PPC_IRQ_SOFT_MASK_DEBUG - WARN_ON_ONCE(!(mfmsr() & MSR_EE)); -#endif - __hard_irq_disable(); -#ifdef CONFIG_PPC_IRQ_SOFT_MASK_DEBUG - } 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 (WARN_ON_ONCE(mfmsr() & MSR_EE)) - __hard_irq_disable(); -#endif - } - - irq_soft_mask_set(IRQS_ALL_DISABLED); - trace_hardirqs_off(); - - /* - * Check if anything needs to be re-emitted. We haven't - * soft-enabled yet to avoid warnings in decrementer_check_overflow - * accessing per-cpu variables - */ - replay = __check_irq_replay(); - - /* We can soft-enable now */ - trace_hardirqs_on(); - irq_soft_mask_set(IRQS_ENABLED); - - /* - * And replay if we have to. This will return with interrupts - * hard-enabled. - */ - if (replay) { - __replay_interrupt(replay); - return; - } - - /* Finally, let's ensure we are hard enabled */ - __hard_irq_enable(); -} -EXPORT_SYMBOL(arch_local_irq_restore); - -/* - * This is specifically called by assembly code to re-enable interrupts - * if they are currently disabled. This is typically called before - * schedule() or do_signal() when returning to userspace. We do it - * in C to avoid the burden of dealing with lockdep etc... - * - * NOTE: This is called with interrupts hard disabled but not marked - * as such in paca->irq_happened, so we need to resync this. - */ -void notrace restore_interrupts(void) -{ - if (irqs_disabled()) { - local_paca->irq_happened |= PACA_IRQ_HARD_DIS; - local_irq_enable(); - } else - __hard_irq_enable(); -} - -/* - * 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; - } - - /* - * 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; @@ -540,13 +126,14 @@ int arch_show_interrupts(struct seq_file *p, int prec) seq_printf(p, "%10u ", per_cpu(irq_stat, j).mce_exceptions); seq_printf(p, " Machine check exceptions\n"); +#ifdef CONFIG_PPC_BOOK3S_64 if (cpu_has_feature(CPU_FTR_HVMODE)) { seq_printf(p, "%*s: ", prec, "HMI"); for_each_online_cpu(j) - seq_printf(p, "%10u ", - per_cpu(irq_stat, j).hmi_exceptions); + seq_printf(p, "%10u ", paca_ptrs[j]->hmi_irqs); seq_printf(p, " Hypervisor Maintenance Interrupts\n"); } +#endif seq_printf(p, "%*s: ", prec, "NMI"); for_each_online_cpu(j) @@ -584,7 +171,9 @@ u64 arch_irq_stat_cpu(unsigned int cpu) sum += per_cpu(irq_stat, cpu).mce_exceptions; sum += per_cpu(irq_stat, cpu).spurious_irqs; sum += per_cpu(irq_stat, cpu).timer_irqs_others; - sum += per_cpu(irq_stat, cpu).hmi_exceptions; +#ifdef CONFIG_PPC_BOOK3S_64 + sum += paca_ptrs[cpu]->hmi_irqs; +#endif sum += per_cpu(irq_stat, cpu).sreset_irqs; #ifdef CONFIG_PPC_WATCHDOG sum += per_cpu(irq_stat, cpu).soft_nmi_irqs; @@ -596,40 +185,65 @@ 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) { -#ifdef CONFIG_DEBUG_STACKOVERFLOW - 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. */ + asm volatile ( + PPC_STLU " %%r1, %[offset](%[sp]) ;" + "mr %%r1, %[sp] ;" +#ifdef CONFIG_PPC_KERNEL_PCREL + "bl %[callee]@notoc ;" +#else + "bl %[callee] ;" #endif + PPC_LL " %%r1, 0(%%r1) ;" + : // Outputs + : // Inputs + [sp] "b" (sp), [offset] "i" (THREAD_SIZE - STACK_FRAME_MIN_SIZE), + [callee] "i" (__do_softirq) + : // Clobbers + "lr", "xer", "ctr", "memory", "cr0", "cr1", "cr5", "cr6", + "cr7", "r0", "r3", "r4", "r5", "r6", "r7", "r8", "r9", "r10", + "r11", "r12" + ); } +#endif -void __do_irq(struct pt_regs *regs) +DEFINE_STATIC_CALL_RET0(ppc_get_irq, *ppc_md.get_irq); + +static void __do_irq(struct pt_regs *regs, unsigned long oldsp) { unsigned int irq; - irq_enter(); - trace_irq_entry(regs); - check_stack_overflow(); + 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(regs)) + do_hard_irq_enable(); /* And finally process it */ if (unlikely(!irq)) @@ -638,39 +252,89 @@ void __do_irq(struct pt_regs *regs) generic_handle_irq(irq); trace_irq_exit(regs); +} - irq_exit(); +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] ;" +#ifdef CONFIG_PPC_KERNEL_PCREL + "bl %[callee]@notoc ;" +#else + "bl %[callee] ;" +#endif + PPC_LL " %%r1, 0(%%r1) ;" + : // Outputs + "+r" (r3) + : // Inputs + [sp] "b" (sp), [offset] "i" (THREAD_SIZE - STACK_FRAME_MIN_SIZE), + [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) +void __do_IRQ(struct pt_regs *regs) { struct pt_regs *old_regs = set_irq_regs(regs); void *cursp, *irqsp, *sirqsp; /* Switch to the irq stack to handle this */ - cursp = (void *)(current_stack_pointer() & ~(THREAD_SIZE - 1)); + cursp = (void *)(current_stack_pointer & ~(THREAD_SIZE - 1)); irqsp = hardirq_ctx[raw_smp_processor_id()]; sirqsp = softirq_ctx[raw_smp_processor_id()]; - /* 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); } +DEFINE_INTERRUPT_HANDLER_ASYNC(do_IRQ) +{ + __do_IRQ(regs); +} + +static void *__init alloc_vm_stack(void) +{ + return __vmalloc_node(THREAD_SIZE, THREAD_ALIGN, THREADINFO_GFP, + NUMA_NO_NODE, (void *)_RET_IP_); +} + +static void __init vmap_irqstack_init(void) +{ + int i; + + for_each_possible_cpu(i) { + softirq_ctx[i] = alloc_vm_stack(); + hardirq_ctx[i] = alloc_vm_stack(); + } +} + + void __init init_IRQ(void) { + if (IS_ENABLED(CONFIG_VMAP_STACK)) + vmap_irqstack_init(); + 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; @@ -679,10 +343,12 @@ 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) { @@ -726,13 +392,3 @@ 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 */ |