diff options
Diffstat (limited to 'kernel/irq/handle.c')
| -rw-r--r-- | kernel/irq/handle.c | 90 |
1 files changed, 79 insertions, 11 deletions
diff --git a/kernel/irq/handle.c b/kernel/irq/handle.c index a8e14c80b405..786f5570a640 100644 --- a/kernel/irq/handle.c +++ b/kernel/irq/handle.c @@ -14,6 +14,8 @@ #include <linux/interrupt.h> #include <linux/kernel_stat.h> +#include <asm/irq_regs.h> + #include <trace/events/irq.h> #include "internals.h" @@ -131,10 +133,56 @@ void __irq_wake_thread(struct irq_desc *desc, struct irqaction *action) */ atomic_inc(&desc->threads_active); - wake_up_process(action->thread); + /* + * This might be a premature wakeup before the thread reached the + * thread function and set the IRQTF_READY bit. It's waiting in + * kthread code with state UNINTERRUPTIBLE. Once it reaches the + * thread function it waits with INTERRUPTIBLE. The wakeup is not + * lost in that case because the thread is guaranteed to observe + * the RUN flag before it goes to sleep in wait_for_interrupt(). + */ + wake_up_state(action->thread, TASK_INTERRUPTIBLE); } -irqreturn_t __handle_irq_event_percpu(struct irq_desc *desc, unsigned int *flags) +static DEFINE_STATIC_KEY_FALSE(irqhandler_duration_check_enabled); +static u64 irqhandler_duration_threshold_ns __ro_after_init; + +static int __init irqhandler_duration_check_setup(char *arg) +{ + unsigned long val; + int ret; + + ret = kstrtoul(arg, 0, &val); + if (ret) { + pr_err("Unable to parse irqhandler.duration_warn_us setting: ret=%d\n", ret); + return 0; + } + + if (!val) { + pr_err("Invalid irqhandler.duration_warn_us setting, must be > 0\n"); + return 0; + } + + irqhandler_duration_threshold_ns = val * 1000; + static_branch_enable(&irqhandler_duration_check_enabled); + + return 1; +} +__setup("irqhandler.duration_warn_us=", irqhandler_duration_check_setup); + +static inline void irqhandler_duration_check(u64 ts_start, unsigned int irq, + const struct irqaction *action) +{ + u64 delta_ns = local_clock() - ts_start; + + if (unlikely(delta_ns > irqhandler_duration_threshold_ns)) { + pr_warn_ratelimited("[CPU%u] long duration of IRQ[%u:%ps], took: %llu us\n", + smp_processor_id(), irq, action->handler, + div_u64(delta_ns, NSEC_PER_USEC)); + } +} + +irqreturn_t __handle_irq_event_percpu(struct irq_desc *desc) { irqreturn_t retval = IRQ_NONE; unsigned int irq = desc->irq_data.irq; @@ -153,7 +201,16 @@ irqreturn_t __handle_irq_event_percpu(struct irq_desc *desc, unsigned int *flags lockdep_hardirq_threaded(); trace_irq_handler_entry(irq, action); - res = action->handler(irq, action->dev_id); + + if (static_branch_unlikely(&irqhandler_duration_check_enabled)) { + u64 ts_start = local_clock(); + + res = action->handler(irq, action->dev_id); + irqhandler_duration_check(ts_start, irq, action); + } else { + res = action->handler(irq, action->dev_id); + } + trace_irq_handler_exit(irq, action, res); if (WARN_ONCE(!irqs_disabled(),"irq %u handler %pS enabled interrupts\n", @@ -172,10 +229,6 @@ irqreturn_t __handle_irq_event_percpu(struct irq_desc *desc, unsigned int *flags } __irq_wake_thread(desc, action); - - /* Fall through - to add to randomness */ - case IRQ_HANDLED: - *flags |= action->flags; break; default: @@ -191,13 +244,12 @@ irqreturn_t __handle_irq_event_percpu(struct irq_desc *desc, unsigned int *flags irqreturn_t handle_irq_event_percpu(struct irq_desc *desc) { irqreturn_t retval; - unsigned int flags = 0; - retval = __handle_irq_event_percpu(desc, &flags); + retval = __handle_irq_event_percpu(desc); - add_interrupt_randomness(desc->irq_data.irq, flags); + add_interrupt_randomness(desc->irq_data.irq); - if (!noirqdebug) + if (!irq_settings_no_debug(desc)) note_interrupt(desc, retval); return retval; } @@ -226,4 +278,20 @@ int __init set_handle_irq(void (*handle_irq)(struct pt_regs *)) handle_arch_irq = handle_irq; return 0; } + +/** + * generic_handle_arch_irq - root irq handler for architectures which do no + * entry accounting themselves + * @regs: Register file coming from the low-level handling code + */ +asmlinkage void noinstr generic_handle_arch_irq(struct pt_regs *regs) +{ + struct pt_regs *old_regs; + + irq_enter(); + old_regs = set_irq_regs(regs); + handle_arch_irq(regs); + set_irq_regs(old_regs); + irq_exit(); +} #endif |