Thomas Gleixner | 52a65ff | 2018-03-14 22:15:19 +0100 | [diff] [blame] | 1 | // SPDX-License-Identifier: GPL-2.0 |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2 | /* |
Ingo Molnar | a34db9b | 2006-06-29 02:24:50 -0700 | [diff] [blame] | 3 | * Copyright (C) 1992, 1998-2006 Linus Torvalds, Ingo Molnar |
| 4 | * Copyright (C) 2005-2006, Thomas Gleixner, Russell King |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 5 | * |
Thomas Gleixner | 99bfce5 | 2018-03-14 22:15:16 +0100 | [diff] [blame] | 6 | * This file contains the core interrupt handling code. Detailed |
| 7 | * information is available in Documentation/core-api/genericirq.rst |
Ingo Molnar | a34db9b | 2006-06-29 02:24:50 -0700 | [diff] [blame] | 8 | * |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 9 | */ |
| 10 | |
| 11 | #include <linux/irq.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 12 | #include <linux/random.h> |
Thomas Gleixner | 3795de2 | 2010-09-22 17:09:43 +0200 | [diff] [blame] | 13 | #include <linux/sched.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 14 | #include <linux/interrupt.h> |
| 15 | #include <linux/kernel_stat.h> |
Thomas Gleixner | 3795de2 | 2010-09-22 17:09:43 +0200 | [diff] [blame] | 16 | |
Steven Rostedt | ad8d75f | 2009-04-14 19:39:12 -0400 | [diff] [blame] | 17 | #include <trace/events/irq.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 18 | |
| 19 | #include "internals.h" |
| 20 | |
Palmer Dabbelt | caacdbf | 2018-03-07 15:57:27 -0800 | [diff] [blame] | 21 | #ifdef CONFIG_GENERIC_IRQ_MULTI_HANDLER |
| 22 | void (*handle_arch_irq)(struct pt_regs *) __ro_after_init; |
| 23 | #endif |
| 24 | |
Thomas Gleixner | 6a6de9e | 2006-06-29 02:24:51 -0700 | [diff] [blame] | 25 | /** |
| 26 | * handle_bad_irq - handle spurious and unhandled irqs |
Henrik Kretzschmar | 43a1dd5 | 2006-08-31 21:27:44 -0700 | [diff] [blame] | 27 | * @desc: description of the interrupt |
Henrik Kretzschmar | 43a1dd5 | 2006-08-31 21:27:44 -0700 | [diff] [blame] | 28 | * |
| 29 | * Handles spurious and unhandled IRQ's. It also prints a debugmessage. |
Thomas Gleixner | 6a6de9e | 2006-06-29 02:24:51 -0700 | [diff] [blame] | 30 | */ |
Thomas Gleixner | bd0b9ac | 2015-09-14 10:42:37 +0200 | [diff] [blame] | 31 | void handle_bad_irq(struct irq_desc *desc) |
Thomas Gleixner | 6a6de9e | 2006-06-29 02:24:51 -0700 | [diff] [blame] | 32 | { |
Thomas Gleixner | bd0b9ac | 2015-09-14 10:42:37 +0200 | [diff] [blame] | 33 | unsigned int irq = irq_desc_get_irq(desc); |
| 34 | |
Ingo Molnar | 43f7775 | 2006-06-29 02:24:58 -0700 | [diff] [blame] | 35 | print_irq_desc(irq, desc); |
Jiang Liu | b51bf95 | 2015-06-04 12:13:25 +0800 | [diff] [blame] | 36 | kstat_incr_irqs_this_cpu(desc); |
Thomas Gleixner | 6a6de9e | 2006-06-29 02:24:51 -0700 | [diff] [blame] | 37 | ack_bad_irq(irq); |
| 38 | } |
Arnd Bergmann | 9d67dc5 | 2015-10-06 22:24:50 +0200 | [diff] [blame] | 39 | EXPORT_SYMBOL_GPL(handle_bad_irq); |
Thomas Gleixner | 6a6de9e | 2006-06-29 02:24:51 -0700 | [diff] [blame] | 40 | |
Thomas Gleixner | f8b5473 | 2006-07-01 22:30:08 +0100 | [diff] [blame] | 41 | /* |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 42 | * Special, empty irq handler: |
| 43 | */ |
David Howells | 7d12e78 | 2006-10-05 14:55:46 +0100 | [diff] [blame] | 44 | irqreturn_t no_action(int cpl, void *dev_id) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 45 | { |
| 46 | return IRQ_NONE; |
| 47 | } |
Alexander Shiyan | d6ee6d2 | 2014-03-22 12:20:31 +0400 | [diff] [blame] | 48 | EXPORT_SYMBOL_GPL(no_action); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 49 | |
Thomas Gleixner | f48fe81 | 2009-03-24 11:46:22 +0100 | [diff] [blame] | 50 | static void warn_no_thread(unsigned int irq, struct irqaction *action) |
| 51 | { |
| 52 | if (test_and_set_bit(IRQTF_WARNED, &action->thread_flags)) |
| 53 | return; |
| 54 | |
| 55 | printk(KERN_WARNING "IRQ %d device %s returned IRQ_WAKE_THREAD " |
| 56 | "but no thread function available.", irq, action->name); |
| 57 | } |
| 58 | |
Thomas Gleixner | a92444c | 2014-02-15 00:55:19 +0000 | [diff] [blame] | 59 | void __irq_wake_thread(struct irq_desc *desc, struct irqaction *action) |
Thomas Gleixner | b5faba2 | 2011-02-23 23:52:13 +0000 | [diff] [blame] | 60 | { |
| 61 | /* |
Alexander Gordeev | 69592db | 2012-03-21 17:22:13 +0100 | [diff] [blame] | 62 | * In case the thread crashed and was killed we just pretend that |
| 63 | * we handled the interrupt. The hardirq handler has disabled the |
| 64 | * device interrupt, so no irq storm is lurking. |
| 65 | */ |
| 66 | if (action->thread->flags & PF_EXITING) |
| 67 | return; |
| 68 | |
| 69 | /* |
| 70 | * Wake up the handler thread for this action. If the |
Thomas Gleixner | b5faba2 | 2011-02-23 23:52:13 +0000 | [diff] [blame] | 71 | * RUNTHREAD bit is already set, nothing to do. |
| 72 | */ |
Alexander Gordeev | 69592db | 2012-03-21 17:22:13 +0100 | [diff] [blame] | 73 | if (test_and_set_bit(IRQTF_RUNTHREAD, &action->thread_flags)) |
Thomas Gleixner | b5faba2 | 2011-02-23 23:52:13 +0000 | [diff] [blame] | 74 | return; |
| 75 | |
| 76 | /* |
| 77 | * It's safe to OR the mask lockless here. We have only two |
| 78 | * places which write to threads_oneshot: This code and the |
| 79 | * irq thread. |
| 80 | * |
| 81 | * This code is the hard irq context and can never run on two |
| 82 | * cpus in parallel. If it ever does we have more serious |
| 83 | * problems than this bitmask. |
| 84 | * |
| 85 | * The irq threads of this irq which clear their "running" bit |
| 86 | * in threads_oneshot are serialized via desc->lock against |
| 87 | * each other and they are serialized against this code by |
| 88 | * IRQS_INPROGRESS. |
| 89 | * |
| 90 | * Hard irq handler: |
| 91 | * |
| 92 | * spin_lock(desc->lock); |
| 93 | * desc->state |= IRQS_INPROGRESS; |
| 94 | * spin_unlock(desc->lock); |
| 95 | * set_bit(IRQTF_RUNTHREAD, &action->thread_flags); |
| 96 | * desc->threads_oneshot |= mask; |
| 97 | * spin_lock(desc->lock); |
| 98 | * desc->state &= ~IRQS_INPROGRESS; |
| 99 | * spin_unlock(desc->lock); |
| 100 | * |
| 101 | * irq thread: |
| 102 | * |
| 103 | * again: |
| 104 | * spin_lock(desc->lock); |
| 105 | * if (desc->state & IRQS_INPROGRESS) { |
| 106 | * spin_unlock(desc->lock); |
| 107 | * while(desc->state & IRQS_INPROGRESS) |
| 108 | * cpu_relax(); |
| 109 | * goto again; |
| 110 | * } |
| 111 | * if (!test_bit(IRQTF_RUNTHREAD, &action->thread_flags)) |
| 112 | * desc->threads_oneshot &= ~mask; |
| 113 | * spin_unlock(desc->lock); |
| 114 | * |
| 115 | * So either the thread waits for us to clear IRQS_INPROGRESS |
| 116 | * or we are waiting in the flow handler for desc->lock to be |
| 117 | * released before we reach this point. The thread also checks |
| 118 | * IRQTF_RUNTHREAD under desc->lock. If set it leaves |
| 119 | * threads_oneshot untouched and runs the thread another time. |
| 120 | */ |
| 121 | desc->threads_oneshot |= action->thread_mask; |
Ido Yariv | 7140ea1 | 2011-12-02 18:24:12 +0200 | [diff] [blame] | 122 | |
| 123 | /* |
| 124 | * We increment the threads_active counter in case we wake up |
| 125 | * the irq thread. The irq thread decrements the counter when |
| 126 | * it returns from the handler or in the exit path and wakes |
| 127 | * up waiters which are stuck in synchronize_irq() when the |
| 128 | * active count becomes zero. synchronize_irq() is serialized |
| 129 | * against this code (hard irq handler) via IRQS_INPROGRESS |
| 130 | * like the finalize_oneshot() code. See comment above. |
| 131 | */ |
| 132 | atomic_inc(&desc->threads_active); |
| 133 | |
Thomas Gleixner | b5faba2 | 2011-02-23 23:52:13 +0000 | [diff] [blame] | 134 | wake_up_process(action->thread); |
| 135 | } |
| 136 | |
Keith Busch | edd14cf | 2016-06-17 16:00:20 -0600 | [diff] [blame] | 137 | irqreturn_t __handle_irq_event_percpu(struct irq_desc *desc, unsigned int *flags) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 138 | { |
Thomas Gleixner | 70433c0 | 2011-02-22 12:50:12 +0100 | [diff] [blame] | 139 | irqreturn_t retval = IRQ_NONE; |
Keith Busch | edd14cf | 2016-06-17 16:00:20 -0600 | [diff] [blame] | 140 | unsigned int irq = desc->irq_data.irq; |
Daniel Lezcano | f944b5a | 2016-01-14 10:54:13 +0100 | [diff] [blame] | 141 | struct irqaction *action; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 142 | |
Daniel Lezcano | b2d3d61 | 2017-06-23 16:11:07 +0200 | [diff] [blame] | 143 | record_irq_time(desc); |
| 144 | |
Daniel Lezcano | f944b5a | 2016-01-14 10:54:13 +0100 | [diff] [blame] | 145 | for_each_action_of_desc(desc, action) { |
Thomas Gleixner | 70433c0 | 2011-02-22 12:50:12 +0100 | [diff] [blame] | 146 | irqreturn_t res; |
| 147 | |
Peter Zijlstra | de8f5e4 | 2020-03-21 12:26:01 +0100 | [diff] [blame] | 148 | /* |
| 149 | * If this IRQ would be threaded under force_irqthreads, mark it so. |
| 150 | */ |
| 151 | if (irq_settings_can_thread(desc) && |
| 152 | !(action->flags & (IRQF_NO_THREAD | IRQF_PERCPU | IRQF_ONESHOT))) |
Linus Torvalds | d5f744f | 2020-03-30 19:14:28 -0700 | [diff] [blame] | 153 | lockdep_hardirq_threaded(); |
Peter Zijlstra | de8f5e4 | 2020-03-21 12:26:01 +0100 | [diff] [blame] | 154 | |
Jason Baron | af39241 | 2009-02-26 10:11:05 -0500 | [diff] [blame] | 155 | trace_irq_handler_entry(irq, action); |
Thomas Gleixner | 70433c0 | 2011-02-22 12:50:12 +0100 | [diff] [blame] | 156 | res = action->handler(irq, action->dev_id); |
| 157 | trace_irq_handler_exit(irq, action, res); |
Thomas Gleixner | 3aa551c | 2009-03-23 18:28:15 +0100 | [diff] [blame] | 158 | |
Sakari Ailus | d75f773 | 2019-03-25 21:32:28 +0200 | [diff] [blame] | 159 | if (WARN_ONCE(!irqs_disabled(),"irq %u handler %pS enabled interrupts\n", |
Thomas Gleixner | 1204e95 | 2011-02-25 17:17:18 +0100 | [diff] [blame] | 160 | irq, action->handler)) |
Thomas Gleixner | b738a50 | 2011-02-02 23:58:19 +0100 | [diff] [blame] | 161 | local_irq_disable(); |
| 162 | |
Thomas Gleixner | 70433c0 | 2011-02-22 12:50:12 +0100 | [diff] [blame] | 163 | switch (res) { |
Thomas Gleixner | 3aa551c | 2009-03-23 18:28:15 +0100 | [diff] [blame] | 164 | case IRQ_WAKE_THREAD: |
| 165 | /* |
Thomas Gleixner | f48fe81 | 2009-03-24 11:46:22 +0100 | [diff] [blame] | 166 | * Catch drivers which return WAKE_THREAD but |
| 167 | * did not set up a thread function |
| 168 | */ |
| 169 | if (unlikely(!action->thread_fn)) { |
| 170 | warn_no_thread(irq, action); |
| 171 | break; |
| 172 | } |
| 173 | |
Thomas Gleixner | a92444c | 2014-02-15 00:55:19 +0000 | [diff] [blame] | 174 | __irq_wake_thread(desc, action); |
Thomas Gleixner | 3aa551c | 2009-03-23 18:28:15 +0100 | [diff] [blame] | 175 | |
Gustavo A. R. Silva | df561f66 | 2020-08-23 17:36:59 -0500 | [diff] [blame] | 176 | fallthrough; /* to add to randomness */ |
Thomas Gleixner | 3aa551c | 2009-03-23 18:28:15 +0100 | [diff] [blame] | 177 | case IRQ_HANDLED: |
Keith Busch | edd14cf | 2016-06-17 16:00:20 -0600 | [diff] [blame] | 178 | *flags |= action->flags; |
Thomas Gleixner | 3aa551c | 2009-03-23 18:28:15 +0100 | [diff] [blame] | 179 | break; |
| 180 | |
| 181 | default: |
| 182 | break; |
| 183 | } |
| 184 | |
Thomas Gleixner | 70433c0 | 2011-02-22 12:50:12 +0100 | [diff] [blame] | 185 | retval |= res; |
Thomas Gleixner | 570540d5 | 2016-01-13 14:07:25 +0100 | [diff] [blame] | 186 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 187 | |
Keith Busch | edd14cf | 2016-06-17 16:00:20 -0600 | [diff] [blame] | 188 | return retval; |
| 189 | } |
| 190 | |
| 191 | irqreturn_t handle_irq_event_percpu(struct irq_desc *desc) |
| 192 | { |
| 193 | irqreturn_t retval; |
| 194 | unsigned int flags = 0; |
| 195 | |
| 196 | retval = __handle_irq_event_percpu(desc, &flags); |
| 197 | |
| 198 | add_interrupt_randomness(desc->irq_data.irq, flags); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 199 | |
Thomas Gleixner | 4912609 | 2011-02-07 01:08:49 +0100 | [diff] [blame] | 200 | if (!noirqdebug) |
Jiang Liu | 0dcdbc9 | 2015-06-04 12:13:28 +0800 | [diff] [blame] | 201 | note_interrupt(desc, retval); |
Thomas Gleixner | 1277a53 | 2011-02-07 01:40:27 +0100 | [diff] [blame] | 202 | return retval; |
Thomas Gleixner | 4912609 | 2011-02-07 01:08:49 +0100 | [diff] [blame] | 203 | } |
| 204 | |
| 205 | irqreturn_t handle_irq_event(struct irq_desc *desc) |
| 206 | { |
Thomas Gleixner | 4912609 | 2011-02-07 01:08:49 +0100 | [diff] [blame] | 207 | irqreturn_t ret; |
| 208 | |
Thomas Gleixner | 2a0d6fb | 2011-02-08 12:17:57 +0100 | [diff] [blame] | 209 | desc->istate &= ~IRQS_PENDING; |
Thomas Gleixner | 32f4125 | 2011-03-28 14:10:52 +0200 | [diff] [blame] | 210 | irqd_set(&desc->irq_data, IRQD_IRQ_INPROGRESS); |
Thomas Gleixner | 4912609 | 2011-02-07 01:08:49 +0100 | [diff] [blame] | 211 | raw_spin_unlock(&desc->lock); |
| 212 | |
Huang Shijie | 71f6434 | 2015-09-02 10:24:55 +0800 | [diff] [blame] | 213 | ret = handle_irq_event_percpu(desc); |
Thomas Gleixner | 4912609 | 2011-02-07 01:08:49 +0100 | [diff] [blame] | 214 | |
| 215 | raw_spin_lock(&desc->lock); |
Thomas Gleixner | 32f4125 | 2011-03-28 14:10:52 +0200 | [diff] [blame] | 216 | irqd_clear(&desc->irq_data, IRQD_IRQ_INPROGRESS); |
Thomas Gleixner | 4912609 | 2011-02-07 01:08:49 +0100 | [diff] [blame] | 217 | return ret; |
| 218 | } |
Palmer Dabbelt | caacdbf | 2018-03-07 15:57:27 -0800 | [diff] [blame] | 219 | |
| 220 | #ifdef CONFIG_GENERIC_IRQ_MULTI_HANDLER |
| 221 | int __init set_handle_irq(void (*handle_irq)(struct pt_regs *)) |
| 222 | { |
| 223 | if (handle_arch_irq) |
| 224 | return -EBUSY; |
| 225 | |
| 226 | handle_arch_irq = handle_irq; |
| 227 | return 0; |
| 228 | } |
| 229 | #endif |