Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1 | /* |
| 2 | * linux/kernel/irq/handle.c |
| 3 | * |
Ingo Molnar | a34db9b | 2006-06-29 02:24:50 -0700 | [diff] [blame] | 4 | * Copyright (C) 1992, 1998-2006 Linus Torvalds, Ingo Molnar |
| 5 | * Copyright (C) 2005-2006, Thomas Gleixner, Russell King |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 6 | * |
| 7 | * This file contains the core interrupt handling code. |
Ingo Molnar | a34db9b | 2006-06-29 02:24:50 -0700 | [diff] [blame] | 8 | * |
| 9 | * Detailed information is available in Documentation/DocBook/genericirq |
| 10 | * |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 11 | */ |
| 12 | |
| 13 | #include <linux/irq.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 14 | #include <linux/random.h> |
Thomas Gleixner | 3795de2 | 2010-09-22 17:09:43 +0200 | [diff] [blame] | 15 | #include <linux/sched.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 16 | #include <linux/interrupt.h> |
| 17 | #include <linux/kernel_stat.h> |
Thomas Gleixner | 3795de2 | 2010-09-22 17:09:43 +0200 | [diff] [blame] | 18 | |
Steven Rostedt | ad8d75f | 2009-04-14 19:39:12 -0400 | [diff] [blame] | 19 | #include <trace/events/irq.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 20 | |
| 21 | #include "internals.h" |
| 22 | |
Thomas Gleixner | 6a6de9e | 2006-06-29 02:24:51 -0700 | [diff] [blame] | 23 | /** |
| 24 | * handle_bad_irq - handle spurious and unhandled irqs |
Henrik Kretzschmar | 43a1dd5 | 2006-08-31 21:27:44 -0700 | [diff] [blame] | 25 | * @irq: the interrupt number |
| 26 | * @desc: description of the interrupt |
Henrik Kretzschmar | 43a1dd5 | 2006-08-31 21:27:44 -0700 | [diff] [blame] | 27 | * |
| 28 | * Handles spurious and unhandled IRQ's. It also prints a debugmessage. |
Thomas Gleixner | 6a6de9e | 2006-06-29 02:24:51 -0700 | [diff] [blame] | 29 | */ |
Thomas Gleixner | d6c88a5 | 2008-10-15 15:27:23 +0200 | [diff] [blame] | 30 | void handle_bad_irq(unsigned int irq, struct irq_desc *desc) |
Thomas Gleixner | 6a6de9e | 2006-06-29 02:24:51 -0700 | [diff] [blame] | 31 | { |
Ingo Molnar | 43f7775 | 2006-06-29 02:24:58 -0700 | [diff] [blame] | 32 | print_irq_desc(irq, desc); |
Thomas Gleixner | d6c88a5 | 2008-10-15 15:27:23 +0200 | [diff] [blame] | 33 | kstat_incr_irqs_this_cpu(irq, desc); |
Thomas Gleixner | 6a6de9e | 2006-06-29 02:24:51 -0700 | [diff] [blame] | 34 | ack_bad_irq(irq); |
| 35 | } |
| 36 | |
Thomas Gleixner | f8b5473 | 2006-07-01 22:30:08 +0100 | [diff] [blame] | 37 | /* |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 38 | * Special, empty irq handler: |
| 39 | */ |
David Howells | 7d12e78 | 2006-10-05 14:55:46 +0100 | [diff] [blame] | 40 | irqreturn_t no_action(int cpl, void *dev_id) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 41 | { |
| 42 | return IRQ_NONE; |
| 43 | } |
| 44 | |
Thomas Gleixner | f48fe81 | 2009-03-24 11:46:22 +0100 | [diff] [blame] | 45 | static void warn_no_thread(unsigned int irq, struct irqaction *action) |
| 46 | { |
| 47 | if (test_and_set_bit(IRQTF_WARNED, &action->thread_flags)) |
| 48 | return; |
| 49 | |
| 50 | printk(KERN_WARNING "IRQ %d device %s returned IRQ_WAKE_THREAD " |
| 51 | "but no thread function available.", irq, action->name); |
| 52 | } |
| 53 | |
Thomas Gleixner | 1277a53 | 2011-02-07 01:40:27 +0100 | [diff] [blame] | 54 | irqreturn_t |
| 55 | handle_irq_event_percpu(struct irq_desc *desc, struct irqaction *action) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 56 | { |
Jan Beulich | 908dcec | 2006-06-23 02:06:00 -0700 | [diff] [blame] | 57 | irqreturn_t ret, retval = IRQ_NONE; |
Thomas Gleixner | 1277a53 | 2011-02-07 01:40:27 +0100 | [diff] [blame] | 58 | unsigned int status = 0, irq = desc->irq_data.irq; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 59 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 60 | do { |
Jason Baron | af39241 | 2009-02-26 10:11:05 -0500 | [diff] [blame] | 61 | trace_irq_handler_entry(irq, action); |
David Howells | 7d12e78 | 2006-10-05 14:55:46 +0100 | [diff] [blame] | 62 | ret = action->handler(irq, action->dev_id); |
Jason Baron | af39241 | 2009-02-26 10:11:05 -0500 | [diff] [blame] | 63 | trace_irq_handler_exit(irq, action, ret); |
Thomas Gleixner | 3aa551c | 2009-03-23 18:28:15 +0100 | [diff] [blame] | 64 | |
Thomas Gleixner | b738a50 | 2011-02-02 23:58:19 +0100 | [diff] [blame] | 65 | if (WARN_ON_ONCE(!irqs_disabled())) |
| 66 | local_irq_disable(); |
| 67 | |
Thomas Gleixner | 3aa551c | 2009-03-23 18:28:15 +0100 | [diff] [blame] | 68 | switch (ret) { |
| 69 | case IRQ_WAKE_THREAD: |
| 70 | /* |
Thomas Gleixner | f48fe81 | 2009-03-24 11:46:22 +0100 | [diff] [blame] | 71 | * Set result to handled so the spurious check |
| 72 | * does not trigger. |
| 73 | */ |
| 74 | ret = IRQ_HANDLED; |
| 75 | |
| 76 | /* |
| 77 | * Catch drivers which return WAKE_THREAD but |
| 78 | * did not set up a thread function |
| 79 | */ |
| 80 | if (unlikely(!action->thread_fn)) { |
| 81 | warn_no_thread(irq, action); |
| 82 | break; |
| 83 | } |
| 84 | |
| 85 | /* |
Thomas Gleixner | 3aa551c | 2009-03-23 18:28:15 +0100 | [diff] [blame] | 86 | * Wake up the handler thread for this |
| 87 | * action. In case the thread crashed and was |
| 88 | * killed we just pretend that we handled the |
| 89 | * interrupt. The hardirq handler above has |
| 90 | * disabled the device interrupt, so no irq |
| 91 | * storm is lurking. |
| 92 | */ |
| 93 | if (likely(!test_bit(IRQTF_DIED, |
| 94 | &action->thread_flags))) { |
| 95 | set_bit(IRQTF_RUNTHREAD, &action->thread_flags); |
| 96 | wake_up_process(action->thread); |
| 97 | } |
| 98 | |
Thomas Gleixner | 3aa551c | 2009-03-23 18:28:15 +0100 | [diff] [blame] | 99 | /* Fall through to add to randomness */ |
| 100 | case IRQ_HANDLED: |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 101 | status |= action->flags; |
Thomas Gleixner | 3aa551c | 2009-03-23 18:28:15 +0100 | [diff] [blame] | 102 | break; |
| 103 | |
| 104 | default: |
| 105 | break; |
| 106 | } |
| 107 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 108 | retval |= ret; |
| 109 | action = action->next; |
| 110 | } while (action); |
| 111 | |
Thomas Gleixner | 3cca53b | 2006-07-01 19:29:31 -0700 | [diff] [blame] | 112 | if (status & IRQF_SAMPLE_RANDOM) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 113 | add_interrupt_randomness(irq); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 114 | |
Thomas Gleixner | 4912609 | 2011-02-07 01:08:49 +0100 | [diff] [blame] | 115 | if (!noirqdebug) |
Thomas Gleixner | 1277a53 | 2011-02-07 01:40:27 +0100 | [diff] [blame] | 116 | note_interrupt(irq, desc, ret); |
| 117 | return retval; |
Thomas Gleixner | 4912609 | 2011-02-07 01:08:49 +0100 | [diff] [blame] | 118 | } |
| 119 | |
| 120 | irqreturn_t handle_irq_event(struct irq_desc *desc) |
| 121 | { |
| 122 | struct irqaction *action = desc->action; |
| 123 | irqreturn_t ret; |
| 124 | |
Thomas Gleixner | 2a0d6fb | 2011-02-08 12:17:57 +0100 | [diff] [blame^] | 125 | irq_compat_clr_pending(desc); |
| 126 | desc->istate &= ~IRQS_PENDING; |
Thomas Gleixner | 009b4c3 | 2011-02-07 21:48:49 +0100 | [diff] [blame] | 127 | irq_compat_set_progress(desc); |
| 128 | desc->istate |= IRQS_INPROGRESS; |
Thomas Gleixner | 4912609 | 2011-02-07 01:08:49 +0100 | [diff] [blame] | 129 | raw_spin_unlock(&desc->lock); |
| 130 | |
| 131 | ret = handle_irq_event_percpu(desc, action); |
| 132 | |
| 133 | raw_spin_lock(&desc->lock); |
Thomas Gleixner | 009b4c3 | 2011-02-07 21:48:49 +0100 | [diff] [blame] | 134 | desc->istate &= ~IRQS_INPROGRESS; |
| 135 | irq_compat_clr_progress(desc); |
Thomas Gleixner | 4912609 | 2011-02-07 01:08:49 +0100 | [diff] [blame] | 136 | return ret; |
| 137 | } |
| 138 | |
| 139 | /** |
| 140 | * handle_IRQ_event - irq action chain handler |
| 141 | * @irq: the interrupt number |
| 142 | * @action: the interrupt action chain for this irq |
| 143 | * |
| 144 | * Handles the action chain of an irq event |
| 145 | */ |
| 146 | irqreturn_t handle_IRQ_event(unsigned int irq, struct irqaction *action) |
| 147 | { |
Thomas Gleixner | 1277a53 | 2011-02-07 01:40:27 +0100 | [diff] [blame] | 148 | return handle_irq_event_percpu(irq_to_desc(irq), action); |
Thomas Gleixner | 4912609 | 2011-02-07 01:08:49 +0100 | [diff] [blame] | 149 | } |