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); |
Jiang Liu | b51bf95 | 2015-06-04 12:13:25 +0800 | [diff] [blame] | 33 | kstat_incr_irqs_this_cpu(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 | } |
Alexander Shiyan | d6ee6d2 | 2014-03-22 12:20:31 +0400 | [diff] [blame] | 44 | EXPORT_SYMBOL_GPL(no_action); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 45 | |
Thomas Gleixner | f48fe81 | 2009-03-24 11:46:22 +0100 | [diff] [blame] | 46 | static void warn_no_thread(unsigned int irq, struct irqaction *action) |
| 47 | { |
| 48 | if (test_and_set_bit(IRQTF_WARNED, &action->thread_flags)) |
| 49 | return; |
| 50 | |
| 51 | printk(KERN_WARNING "IRQ %d device %s returned IRQ_WAKE_THREAD " |
| 52 | "but no thread function available.", irq, action->name); |
| 53 | } |
| 54 | |
Thomas Gleixner | a92444c | 2014-02-15 00:55:19 +0000 | [diff] [blame] | 55 | void __irq_wake_thread(struct irq_desc *desc, struct irqaction *action) |
Thomas Gleixner | b5faba2 | 2011-02-23 23:52:13 +0000 | [diff] [blame] | 56 | { |
| 57 | /* |
Alexander Gordeev | 69592db | 2012-03-21 17:22:13 +0100 | [diff] [blame] | 58 | * In case the thread crashed and was killed we just pretend that |
| 59 | * we handled the interrupt. The hardirq handler has disabled the |
| 60 | * device interrupt, so no irq storm is lurking. |
| 61 | */ |
| 62 | if (action->thread->flags & PF_EXITING) |
| 63 | return; |
| 64 | |
| 65 | /* |
| 66 | * Wake up the handler thread for this action. If the |
Thomas Gleixner | b5faba2 | 2011-02-23 23:52:13 +0000 | [diff] [blame] | 67 | * RUNTHREAD bit is already set, nothing to do. |
| 68 | */ |
Alexander Gordeev | 69592db | 2012-03-21 17:22:13 +0100 | [diff] [blame] | 69 | if (test_and_set_bit(IRQTF_RUNTHREAD, &action->thread_flags)) |
Thomas Gleixner | b5faba2 | 2011-02-23 23:52:13 +0000 | [diff] [blame] | 70 | return; |
| 71 | |
| 72 | /* |
| 73 | * It's safe to OR the mask lockless here. We have only two |
| 74 | * places which write to threads_oneshot: This code and the |
| 75 | * irq thread. |
| 76 | * |
| 77 | * This code is the hard irq context and can never run on two |
| 78 | * cpus in parallel. If it ever does we have more serious |
| 79 | * problems than this bitmask. |
| 80 | * |
| 81 | * The irq threads of this irq which clear their "running" bit |
| 82 | * in threads_oneshot are serialized via desc->lock against |
| 83 | * each other and they are serialized against this code by |
| 84 | * IRQS_INPROGRESS. |
| 85 | * |
| 86 | * Hard irq handler: |
| 87 | * |
| 88 | * spin_lock(desc->lock); |
| 89 | * desc->state |= IRQS_INPROGRESS; |
| 90 | * spin_unlock(desc->lock); |
| 91 | * set_bit(IRQTF_RUNTHREAD, &action->thread_flags); |
| 92 | * desc->threads_oneshot |= mask; |
| 93 | * spin_lock(desc->lock); |
| 94 | * desc->state &= ~IRQS_INPROGRESS; |
| 95 | * spin_unlock(desc->lock); |
| 96 | * |
| 97 | * irq thread: |
| 98 | * |
| 99 | * again: |
| 100 | * spin_lock(desc->lock); |
| 101 | * if (desc->state & IRQS_INPROGRESS) { |
| 102 | * spin_unlock(desc->lock); |
| 103 | * while(desc->state & IRQS_INPROGRESS) |
| 104 | * cpu_relax(); |
| 105 | * goto again; |
| 106 | * } |
| 107 | * if (!test_bit(IRQTF_RUNTHREAD, &action->thread_flags)) |
| 108 | * desc->threads_oneshot &= ~mask; |
| 109 | * spin_unlock(desc->lock); |
| 110 | * |
| 111 | * So either the thread waits for us to clear IRQS_INPROGRESS |
| 112 | * or we are waiting in the flow handler for desc->lock to be |
| 113 | * released before we reach this point. The thread also checks |
| 114 | * IRQTF_RUNTHREAD under desc->lock. If set it leaves |
| 115 | * threads_oneshot untouched and runs the thread another time. |
| 116 | */ |
| 117 | desc->threads_oneshot |= action->thread_mask; |
Ido Yariv | 7140ea1 | 2011-12-02 18:24:12 +0200 | [diff] [blame] | 118 | |
| 119 | /* |
| 120 | * We increment the threads_active counter in case we wake up |
| 121 | * the irq thread. The irq thread decrements the counter when |
| 122 | * it returns from the handler or in the exit path and wakes |
| 123 | * up waiters which are stuck in synchronize_irq() when the |
| 124 | * active count becomes zero. synchronize_irq() is serialized |
| 125 | * against this code (hard irq handler) via IRQS_INPROGRESS |
| 126 | * like the finalize_oneshot() code. See comment above. |
| 127 | */ |
| 128 | atomic_inc(&desc->threads_active); |
| 129 | |
Thomas Gleixner | b5faba2 | 2011-02-23 23:52:13 +0000 | [diff] [blame] | 130 | wake_up_process(action->thread); |
| 131 | } |
| 132 | |
Thomas Gleixner | 1277a53 | 2011-02-07 01:40:27 +0100 | [diff] [blame] | 133 | irqreturn_t |
| 134 | handle_irq_event_percpu(struct irq_desc *desc, struct irqaction *action) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 135 | { |
Thomas Gleixner | 70433c0 | 2011-02-22 12:50:12 +0100 | [diff] [blame] | 136 | irqreturn_t retval = IRQ_NONE; |
Theodore Ts'o | 775f4b2 | 2012-07-02 07:52:16 -0400 | [diff] [blame] | 137 | unsigned int flags = 0, irq = desc->irq_data.irq; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 138 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 139 | do { |
Thomas Gleixner | 70433c0 | 2011-02-22 12:50:12 +0100 | [diff] [blame] | 140 | irqreturn_t res; |
| 141 | |
Jason Baron | af39241 | 2009-02-26 10:11:05 -0500 | [diff] [blame] | 142 | trace_irq_handler_entry(irq, action); |
Thomas Gleixner | 70433c0 | 2011-02-22 12:50:12 +0100 | [diff] [blame] | 143 | res = action->handler(irq, action->dev_id); |
| 144 | trace_irq_handler_exit(irq, action, res); |
Thomas Gleixner | 3aa551c | 2009-03-23 18:28:15 +0100 | [diff] [blame] | 145 | |
Thomas Gleixner | 1204e95 | 2011-02-25 17:17:18 +0100 | [diff] [blame] | 146 | if (WARN_ONCE(!irqs_disabled(),"irq %u handler %pF enabled interrupts\n", |
| 147 | irq, action->handler)) |
Thomas Gleixner | b738a50 | 2011-02-02 23:58:19 +0100 | [diff] [blame] | 148 | local_irq_disable(); |
| 149 | |
Thomas Gleixner | 70433c0 | 2011-02-22 12:50:12 +0100 | [diff] [blame] | 150 | switch (res) { |
Thomas Gleixner | 3aa551c | 2009-03-23 18:28:15 +0100 | [diff] [blame] | 151 | case IRQ_WAKE_THREAD: |
| 152 | /* |
Thomas Gleixner | f48fe81 | 2009-03-24 11:46:22 +0100 | [diff] [blame] | 153 | * Catch drivers which return WAKE_THREAD but |
| 154 | * did not set up a thread function |
| 155 | */ |
| 156 | if (unlikely(!action->thread_fn)) { |
| 157 | warn_no_thread(irq, action); |
| 158 | break; |
| 159 | } |
| 160 | |
Thomas Gleixner | a92444c | 2014-02-15 00:55:19 +0000 | [diff] [blame] | 161 | __irq_wake_thread(desc, action); |
Thomas Gleixner | 3aa551c | 2009-03-23 18:28:15 +0100 | [diff] [blame] | 162 | |
Thomas Gleixner | 3aa551c | 2009-03-23 18:28:15 +0100 | [diff] [blame] | 163 | /* Fall through to add to randomness */ |
| 164 | case IRQ_HANDLED: |
Theodore Ts'o | 775f4b2 | 2012-07-02 07:52:16 -0400 | [diff] [blame] | 165 | flags |= action->flags; |
Thomas Gleixner | 3aa551c | 2009-03-23 18:28:15 +0100 | [diff] [blame] | 166 | break; |
| 167 | |
| 168 | default: |
| 169 | break; |
| 170 | } |
| 171 | |
Thomas Gleixner | 70433c0 | 2011-02-22 12:50:12 +0100 | [diff] [blame] | 172 | retval |= res; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 173 | action = action->next; |
| 174 | } while (action); |
| 175 | |
Theodore Ts'o | 775f4b2 | 2012-07-02 07:52:16 -0400 | [diff] [blame] | 176 | add_interrupt_randomness(irq, flags); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 177 | |
Thomas Gleixner | 4912609 | 2011-02-07 01:08:49 +0100 | [diff] [blame] | 178 | if (!noirqdebug) |
Jiang Liu | 0dcdbc9 | 2015-06-04 12:13:28 +0800 | [diff] [blame^] | 179 | note_interrupt(desc, retval); |
Thomas Gleixner | 1277a53 | 2011-02-07 01:40:27 +0100 | [diff] [blame] | 180 | return retval; |
Thomas Gleixner | 4912609 | 2011-02-07 01:08:49 +0100 | [diff] [blame] | 181 | } |
| 182 | |
| 183 | irqreturn_t handle_irq_event(struct irq_desc *desc) |
| 184 | { |
| 185 | struct irqaction *action = desc->action; |
| 186 | irqreturn_t ret; |
| 187 | |
Thomas Gleixner | 2a0d6fb | 2011-02-08 12:17:57 +0100 | [diff] [blame] | 188 | desc->istate &= ~IRQS_PENDING; |
Thomas Gleixner | 32f4125 | 2011-03-28 14:10:52 +0200 | [diff] [blame] | 189 | irqd_set(&desc->irq_data, IRQD_IRQ_INPROGRESS); |
Thomas Gleixner | 4912609 | 2011-02-07 01:08:49 +0100 | [diff] [blame] | 190 | raw_spin_unlock(&desc->lock); |
| 191 | |
| 192 | ret = handle_irq_event_percpu(desc, action); |
| 193 | |
| 194 | raw_spin_lock(&desc->lock); |
Thomas Gleixner | 32f4125 | 2011-03-28 14:10:52 +0200 | [diff] [blame] | 195 | irqd_clear(&desc->irq_data, IRQD_IRQ_INPROGRESS); |
Thomas Gleixner | 4912609 | 2011-02-07 01:08:49 +0100 | [diff] [blame] | 196 | return ret; |
| 197 | } |