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Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
2 * linux/kernel/irq/manage.c
3 *
Ingo Molnara34db9b2006-06-29 02:24:50 -07004 * Copyright (C) 1992, 1998-2006 Linus Torvalds, Ingo Molnar
5 * Copyright (C) 2005-2006 Thomas Gleixner
Linus Torvalds1da177e2005-04-16 15:20:36 -07006 *
7 * This file contains driver APIs to the irq subsystem.
8 */
9
Andrew Morton97fd75b2012-05-31 16:26:07 -070010#define pr_fmt(fmt) "genirq: " fmt
11
Linus Torvalds1da177e2005-04-16 15:20:36 -070012#include <linux/irq.h>
Thomas Gleixner3aa551c2009-03-23 18:28:15 +010013#include <linux/kthread.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070014#include <linux/module.h>
15#include <linux/random.h>
16#include <linux/interrupt.h>
Robert P. J. Day1aeb2722008-04-29 00:59:25 -070017#include <linux/slab.h>
Thomas Gleixner3aa551c2009-03-23 18:28:15 +010018#include <linux/sched.h>
Clark Williams8bd75c72013-02-07 09:47:07 -060019#include <linux/sched/rt.h>
Oleg Nesterov4d1d61a2012-05-11 10:59:08 +100020#include <linux/task_work.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070021
22#include "internals.h"
23
Thomas Gleixner8d32a302011-02-23 23:52:23 +000024#ifdef CONFIG_IRQ_FORCED_THREADING
25__read_mostly bool force_irqthreads;
26
27static int __init setup_forced_irqthreads(char *arg)
28{
29 force_irqthreads = true;
30 return 0;
31}
32early_param("threadirqs", setup_forced_irqthreads);
33#endif
34
Thomas Gleixner18258f72014-02-15 00:55:18 +000035static void __synchronize_hardirq(struct irq_desc *desc)
Linus Torvalds1da177e2005-04-16 15:20:36 -070036{
Thomas Gleixner32f41252011-03-28 14:10:52 +020037 bool inprogress;
Linus Torvalds1da177e2005-04-16 15:20:36 -070038
Herbert Xua98ce5c2007-10-23 11:26:25 +080039 do {
40 unsigned long flags;
41
42 /*
43 * Wait until we're out of the critical section. This might
44 * give the wrong answer due to the lack of memory barriers.
45 */
Thomas Gleixner32f41252011-03-28 14:10:52 +020046 while (irqd_irq_inprogress(&desc->irq_data))
Herbert Xua98ce5c2007-10-23 11:26:25 +080047 cpu_relax();
48
49 /* Ok, that indicated we're done: double-check carefully. */
Thomas Gleixner239007b2009-11-17 16:46:45 +010050 raw_spin_lock_irqsave(&desc->lock, flags);
Thomas Gleixner32f41252011-03-28 14:10:52 +020051 inprogress = irqd_irq_inprogress(&desc->irq_data);
Thomas Gleixner239007b2009-11-17 16:46:45 +010052 raw_spin_unlock_irqrestore(&desc->lock, flags);
Herbert Xua98ce5c2007-10-23 11:26:25 +080053
54 /* Oops, that failed? */
Thomas Gleixner32f41252011-03-28 14:10:52 +020055 } while (inprogress);
Thomas Gleixner18258f72014-02-15 00:55:18 +000056}
Thomas Gleixner3aa551c2009-03-23 18:28:15 +010057
Thomas Gleixner18258f72014-02-15 00:55:18 +000058/**
59 * synchronize_hardirq - wait for pending hard IRQ handlers (on other CPUs)
60 * @irq: interrupt number to wait for
61 *
62 * This function waits for any pending hard IRQ handlers for this
63 * interrupt to complete before returning. If you use this
64 * function while holding a resource the IRQ handler may need you
65 * will deadlock. It does not take associated threaded handlers
66 * into account.
67 *
68 * Do not use this for shutdown scenarios where you must be sure
69 * that all parts (hardirq and threaded handler) have completed.
70 *
71 * This function may be called - with care - from IRQ context.
72 */
73void synchronize_hardirq(unsigned int irq)
74{
75 struct irq_desc *desc = irq_to_desc(irq);
76
77 if (desc)
78 __synchronize_hardirq(desc);
79}
80EXPORT_SYMBOL(synchronize_hardirq);
81
82/**
83 * synchronize_irq - wait for pending IRQ handlers (on other CPUs)
84 * @irq: interrupt number to wait for
85 *
86 * This function waits for any pending IRQ handlers for this interrupt
87 * to complete before returning. If you use this function while
88 * holding a resource the IRQ handler may need you will deadlock.
89 *
90 * This function may be called - with care - from IRQ context.
91 */
92void synchronize_irq(unsigned int irq)
93{
94 struct irq_desc *desc = irq_to_desc(irq);
95
96 if (desc) {
97 __synchronize_hardirq(desc);
98 /*
99 * We made sure that no hardirq handler is
100 * running. Now verify that no threaded handlers are
101 * active.
102 */
103 wait_event(desc->wait_for_threads,
104 !atomic_read(&desc->threads_active));
105 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700106}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700107EXPORT_SYMBOL(synchronize_irq);
108
Thomas Gleixner3aa551c2009-03-23 18:28:15 +0100109#ifdef CONFIG_SMP
110cpumask_var_t irq_default_affinity;
111
Thomas Gleixner771ee3b2007-02-16 01:27:25 -0800112/**
113 * irq_can_set_affinity - Check if the affinity of a given irq can be set
114 * @irq: Interrupt to check
115 *
116 */
117int irq_can_set_affinity(unsigned int irq)
118{
Yinghai Lu08678b02008-08-19 20:50:05 -0700119 struct irq_desc *desc = irq_to_desc(irq);
Thomas Gleixner771ee3b2007-02-16 01:27:25 -0800120
Thomas Gleixnerbce43032011-02-10 22:37:41 +0100121 if (!desc || !irqd_can_balance(&desc->irq_data) ||
122 !desc->irq_data.chip || !desc->irq_data.chip->irq_set_affinity)
Thomas Gleixner771ee3b2007-02-16 01:27:25 -0800123 return 0;
124
125 return 1;
126}
127
Thomas Gleixner591d2fb2009-07-21 11:09:39 +0200128/**
129 * irq_set_thread_affinity - Notify irq threads to adjust affinity
130 * @desc: irq descriptor which has affitnity changed
131 *
132 * We just set IRQTF_AFFINITY and delegate the affinity setting
133 * to the interrupt thread itself. We can not call
134 * set_cpus_allowed_ptr() here as we hold desc->lock and this
135 * code can be called from hard interrupt context.
136 */
137void irq_set_thread_affinity(struct irq_desc *desc)
Thomas Gleixner3aa551c2009-03-23 18:28:15 +0100138{
139 struct irqaction *action = desc->action;
140
141 while (action) {
142 if (action->thread)
Thomas Gleixner591d2fb2009-07-21 11:09:39 +0200143 set_bit(IRQTF_AFFINITY, &action->thread_flags);
Thomas Gleixner3aa551c2009-03-23 18:28:15 +0100144 action = action->next;
145 }
146}
147
Thomas Gleixner1fa46f12011-02-07 16:46:58 +0100148#ifdef CONFIG_GENERIC_PENDING_IRQ
Thomas Gleixner0ef5ca12011-03-28 21:59:37 +0200149static inline bool irq_can_move_pcntxt(struct irq_data *data)
Thomas Gleixner1fa46f12011-02-07 16:46:58 +0100150{
Thomas Gleixner0ef5ca12011-03-28 21:59:37 +0200151 return irqd_can_move_in_process_context(data);
Thomas Gleixner1fa46f12011-02-07 16:46:58 +0100152}
Thomas Gleixner0ef5ca12011-03-28 21:59:37 +0200153static inline bool irq_move_pending(struct irq_data *data)
Thomas Gleixner1fa46f12011-02-07 16:46:58 +0100154{
Thomas Gleixner0ef5ca12011-03-28 21:59:37 +0200155 return irqd_is_setaffinity_pending(data);
Thomas Gleixner1fa46f12011-02-07 16:46:58 +0100156}
157static inline void
158irq_copy_pending(struct irq_desc *desc, const struct cpumask *mask)
159{
160 cpumask_copy(desc->pending_mask, mask);
161}
162static inline void
163irq_get_pending(struct cpumask *mask, struct irq_desc *desc)
164{
165 cpumask_copy(mask, desc->pending_mask);
166}
167#else
Thomas Gleixner0ef5ca12011-03-28 21:59:37 +0200168static inline bool irq_can_move_pcntxt(struct irq_data *data) { return true; }
Thomas Gleixnercd22c0e2011-03-29 11:36:05 +0200169static inline bool irq_move_pending(struct irq_data *data) { return false; }
Thomas Gleixner1fa46f12011-02-07 16:46:58 +0100170static inline void
171irq_copy_pending(struct irq_desc *desc, const struct cpumask *mask) { }
172static inline void
173irq_get_pending(struct cpumask *mask, struct irq_desc *desc) { }
174#endif
175
Jiang Liu818b0f32012-03-30 23:11:34 +0800176int irq_do_set_affinity(struct irq_data *data, const struct cpumask *mask,
177 bool force)
178{
179 struct irq_desc *desc = irq_data_to_desc(data);
180 struct irq_chip *chip = irq_data_get_irq_chip(data);
181 int ret;
182
Thomas Gleixner01f8fa42014-04-16 14:36:44 +0000183 ret = chip->irq_set_affinity(data, mask, force);
Jiang Liu818b0f32012-03-30 23:11:34 +0800184 switch (ret) {
185 case IRQ_SET_MASK_OK:
186 cpumask_copy(data->affinity, mask);
187 case IRQ_SET_MASK_OK_NOCOPY:
188 irq_set_thread_affinity(desc);
189 ret = 0;
190 }
191
192 return ret;
193}
194
Thomas Gleixner01f8fa42014-04-16 14:36:44 +0000195int irq_set_affinity_locked(struct irq_data *data, const struct cpumask *mask,
196 bool force)
David Daneyc2d0c552011-03-25 12:38:50 -0700197{
198 struct irq_chip *chip = irq_data_get_irq_chip(data);
199 struct irq_desc *desc = irq_data_to_desc(data);
200 int ret = 0;
201
202 if (!chip || !chip->irq_set_affinity)
203 return -EINVAL;
204
Thomas Gleixner0ef5ca12011-03-28 21:59:37 +0200205 if (irq_can_move_pcntxt(data)) {
Thomas Gleixner01f8fa42014-04-16 14:36:44 +0000206 ret = irq_do_set_affinity(data, mask, force);
David Daneyc2d0c552011-03-25 12:38:50 -0700207 } else {
208 irqd_set_move_pending(data);
209 irq_copy_pending(desc, mask);
210 }
211
212 if (desc->affinity_notify) {
213 kref_get(&desc->affinity_notify->kref);
214 schedule_work(&desc->affinity_notify->work);
215 }
David Daneyc2d0c552011-03-25 12:38:50 -0700216 irqd_set(data, IRQD_AFFINITY_SET);
217
218 return ret;
219}
220
Thomas Gleixner01f8fa42014-04-16 14:36:44 +0000221int __irq_set_affinity(unsigned int irq, const struct cpumask *mask, bool force)
Thomas Gleixner771ee3b2007-02-16 01:27:25 -0800222{
Yinghai Lu08678b02008-08-19 20:50:05 -0700223 struct irq_desc *desc = irq_to_desc(irq);
Thomas Gleixnerf6d87f42008-11-07 13:18:30 +0100224 unsigned long flags;
David Daneyc2d0c552011-03-25 12:38:50 -0700225 int ret;
Thomas Gleixner771ee3b2007-02-16 01:27:25 -0800226
David Daneyc2d0c552011-03-25 12:38:50 -0700227 if (!desc)
Thomas Gleixner771ee3b2007-02-16 01:27:25 -0800228 return -EINVAL;
229
Thomas Gleixner239007b2009-11-17 16:46:45 +0100230 raw_spin_lock_irqsave(&desc->lock, flags);
Thomas Gleixner01f8fa42014-04-16 14:36:44 +0000231 ret = irq_set_affinity_locked(irq_desc_get_irq_data(desc), mask, force);
Thomas Gleixner239007b2009-11-17 16:46:45 +0100232 raw_spin_unlock_irqrestore(&desc->lock, flags);
Thomas Gleixner1fa46f12011-02-07 16:46:58 +0100233 return ret;
Thomas Gleixner771ee3b2007-02-16 01:27:25 -0800234}
235
Peter P Waskiewicz Jre7a297b2010-04-30 14:44:50 -0700236int irq_set_affinity_hint(unsigned int irq, const struct cpumask *m)
237{
Peter P Waskiewicz Jre7a297b2010-04-30 14:44:50 -0700238 unsigned long flags;
Marc Zyngier31d9d9b2011-09-23 17:03:06 +0100239 struct irq_desc *desc = irq_get_desc_lock(irq, &flags, IRQ_GET_DESC_CHECK_GLOBAL);
Peter P Waskiewicz Jre7a297b2010-04-30 14:44:50 -0700240
241 if (!desc)
242 return -EINVAL;
Peter P Waskiewicz Jre7a297b2010-04-30 14:44:50 -0700243 desc->affinity_hint = m;
Thomas Gleixner02725e72011-02-12 10:37:36 +0100244 irq_put_desc_unlock(desc, flags);
Peter P Waskiewicz Jre7a297b2010-04-30 14:44:50 -0700245 return 0;
246}
247EXPORT_SYMBOL_GPL(irq_set_affinity_hint);
248
Ben Hutchingscd7eab42011-01-19 21:01:44 +0000249static void irq_affinity_notify(struct work_struct *work)
250{
251 struct irq_affinity_notify *notify =
252 container_of(work, struct irq_affinity_notify, work);
253 struct irq_desc *desc = irq_to_desc(notify->irq);
254 cpumask_var_t cpumask;
255 unsigned long flags;
256
Thomas Gleixner1fa46f12011-02-07 16:46:58 +0100257 if (!desc || !alloc_cpumask_var(&cpumask, GFP_KERNEL))
Ben Hutchingscd7eab42011-01-19 21:01:44 +0000258 goto out;
259
260 raw_spin_lock_irqsave(&desc->lock, flags);
Thomas Gleixner0ef5ca12011-03-28 21:59:37 +0200261 if (irq_move_pending(&desc->irq_data))
Thomas Gleixner1fa46f12011-02-07 16:46:58 +0100262 irq_get_pending(cpumask, desc);
Ben Hutchingscd7eab42011-01-19 21:01:44 +0000263 else
Thomas Gleixner1fb0ef32011-01-31 08:57:41 +0100264 cpumask_copy(cpumask, desc->irq_data.affinity);
Ben Hutchingscd7eab42011-01-19 21:01:44 +0000265 raw_spin_unlock_irqrestore(&desc->lock, flags);
266
267 notify->notify(notify, cpumask);
268
269 free_cpumask_var(cpumask);
270out:
271 kref_put(&notify->kref, notify->release);
272}
273
274/**
275 * irq_set_affinity_notifier - control notification of IRQ affinity changes
276 * @irq: Interrupt for which to enable/disable notification
277 * @notify: Context for notification, or %NULL to disable
278 * notification. Function pointers must be initialised;
279 * the other fields will be initialised by this function.
280 *
281 * Must be called in process context. Notification may only be enabled
282 * after the IRQ is allocated and must be disabled before the IRQ is
283 * freed using free_irq().
284 */
285int
286irq_set_affinity_notifier(unsigned int irq, struct irq_affinity_notify *notify)
287{
288 struct irq_desc *desc = irq_to_desc(irq);
289 struct irq_affinity_notify *old_notify;
290 unsigned long flags;
291
292 /* The release function is promised process context */
293 might_sleep();
294
295 if (!desc)
296 return -EINVAL;
297
298 /* Complete initialisation of *notify */
299 if (notify) {
300 notify->irq = irq;
301 kref_init(&notify->kref);
302 INIT_WORK(&notify->work, irq_affinity_notify);
303 }
304
305 raw_spin_lock_irqsave(&desc->lock, flags);
306 old_notify = desc->affinity_notify;
307 desc->affinity_notify = notify;
308 raw_spin_unlock_irqrestore(&desc->lock, flags);
309
310 if (old_notify)
311 kref_put(&old_notify->kref, old_notify->release);
312
313 return 0;
314}
315EXPORT_SYMBOL_GPL(irq_set_affinity_notifier);
316
Max Krasnyansky18404752008-05-29 11:02:52 -0700317#ifndef CONFIG_AUTO_IRQ_AFFINITY
318/*
319 * Generic version of the affinity autoselector.
320 */
Thomas Gleixner3b8249e2011-02-07 16:02:20 +0100321static int
322setup_affinity(unsigned int irq, struct irq_desc *desc, struct cpumask *mask)
Max Krasnyansky18404752008-05-29 11:02:52 -0700323{
Thomas Gleixner569bda82011-02-07 17:05:08 +0100324 struct cpumask *set = irq_default_affinity;
Jiang Liu818b0f32012-03-30 23:11:34 +0800325 int node = desc->irq_data.node;
Thomas Gleixner569bda82011-02-07 17:05:08 +0100326
Thomas Gleixnerb0082072011-02-07 17:30:50 +0100327 /* Excludes PER_CPU and NO_BALANCE interrupts */
Max Krasnyansky18404752008-05-29 11:02:52 -0700328 if (!irq_can_set_affinity(irq))
329 return 0;
330
Thomas Gleixnerf6d87f42008-11-07 13:18:30 +0100331 /*
332 * Preserve an userspace affinity setup, but make sure that
333 * one of the targets is online.
334 */
Thomas Gleixner2bdd1052011-02-08 17:22:00 +0100335 if (irqd_has_set(&desc->irq_data, IRQD_AFFINITY_SET)) {
Thomas Gleixner569bda82011-02-07 17:05:08 +0100336 if (cpumask_intersects(desc->irq_data.affinity,
337 cpu_online_mask))
338 set = desc->irq_data.affinity;
Thomas Gleixner0c6f8a82011-03-28 13:32:20 +0200339 else
Thomas Gleixner2bdd1052011-02-08 17:22:00 +0100340 irqd_clear(&desc->irq_data, IRQD_AFFINITY_SET);
Thomas Gleixnerf6d87f42008-11-07 13:18:30 +0100341 }
Max Krasnyansky18404752008-05-29 11:02:52 -0700342
Thomas Gleixner3b8249e2011-02-07 16:02:20 +0100343 cpumask_and(mask, cpu_online_mask, set);
Prarit Bhargava241fc642012-03-26 15:02:18 -0400344 if (node != NUMA_NO_NODE) {
345 const struct cpumask *nodemask = cpumask_of_node(node);
346
347 /* make sure at least one of the cpus in nodemask is online */
348 if (cpumask_intersects(mask, nodemask))
349 cpumask_and(mask, mask, nodemask);
350 }
Jiang Liu818b0f32012-03-30 23:11:34 +0800351 irq_do_set_affinity(&desc->irq_data, mask, false);
Max Krasnyansky18404752008-05-29 11:02:52 -0700352 return 0;
353}
Thomas Gleixnerf6d87f42008-11-07 13:18:30 +0100354#else
Thomas Gleixner3b8249e2011-02-07 16:02:20 +0100355static inline int
356setup_affinity(unsigned int irq, struct irq_desc *d, struct cpumask *mask)
Thomas Gleixnerf6d87f42008-11-07 13:18:30 +0100357{
358 return irq_select_affinity(irq);
359}
Max Krasnyansky18404752008-05-29 11:02:52 -0700360#endif
361
Thomas Gleixnerf6d87f42008-11-07 13:18:30 +0100362/*
363 * Called when affinity is set via /proc/irq
364 */
Thomas Gleixner3b8249e2011-02-07 16:02:20 +0100365int irq_select_affinity_usr(unsigned int irq, struct cpumask *mask)
Thomas Gleixnerf6d87f42008-11-07 13:18:30 +0100366{
367 struct irq_desc *desc = irq_to_desc(irq);
368 unsigned long flags;
369 int ret;
370
Thomas Gleixner239007b2009-11-17 16:46:45 +0100371 raw_spin_lock_irqsave(&desc->lock, flags);
Thomas Gleixner3b8249e2011-02-07 16:02:20 +0100372 ret = setup_affinity(irq, desc, mask);
Thomas Gleixner239007b2009-11-17 16:46:45 +0100373 raw_spin_unlock_irqrestore(&desc->lock, flags);
Thomas Gleixnerf6d87f42008-11-07 13:18:30 +0100374 return ret;
375}
376
377#else
Thomas Gleixner3b8249e2011-02-07 16:02:20 +0100378static inline int
379setup_affinity(unsigned int irq, struct irq_desc *desc, struct cpumask *mask)
Thomas Gleixnerf6d87f42008-11-07 13:18:30 +0100380{
381 return 0;
382}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700383#endif
384
Rafael J. Wysocki0a0c5162009-03-16 22:33:49 +0100385void __disable_irq(struct irq_desc *desc, unsigned int irq, bool suspend)
386{
387 if (suspend) {
Ian Campbell685fd0b2010-07-29 11:16:32 +0100388 if (!desc->action || (desc->action->flags & IRQF_NO_SUSPEND))
Rafael J. Wysocki0a0c5162009-03-16 22:33:49 +0100389 return;
Thomas Gleixnerc531e832011-02-08 12:44:58 +0100390 desc->istate |= IRQS_SUSPENDED;
Rafael J. Wysocki0a0c5162009-03-16 22:33:49 +0100391 }
392
Thomas Gleixner3aae9942011-02-04 10:17:52 +0100393 if (!desc->depth++)
Thomas Gleixner87923472011-02-03 12:27:44 +0100394 irq_disable(desc);
Rafael J. Wysocki0a0c5162009-03-16 22:33:49 +0100395}
396
Thomas Gleixner02725e72011-02-12 10:37:36 +0100397static int __disable_irq_nosync(unsigned int irq)
398{
399 unsigned long flags;
Marc Zyngier31d9d9b2011-09-23 17:03:06 +0100400 struct irq_desc *desc = irq_get_desc_buslock(irq, &flags, IRQ_GET_DESC_CHECK_GLOBAL);
Thomas Gleixner02725e72011-02-12 10:37:36 +0100401
402 if (!desc)
403 return -EINVAL;
404 __disable_irq(desc, irq, false);
405 irq_put_desc_busunlock(desc, flags);
406 return 0;
407}
408
Linus Torvalds1da177e2005-04-16 15:20:36 -0700409/**
410 * disable_irq_nosync - disable an irq without waiting
411 * @irq: Interrupt to disable
412 *
413 * Disable the selected interrupt line. Disables and Enables are
414 * nested.
415 * Unlike disable_irq(), this function does not ensure existing
416 * instances of the IRQ handler have completed before returning.
417 *
418 * This function may be called from IRQ context.
419 */
420void disable_irq_nosync(unsigned int irq)
421{
Thomas Gleixner02725e72011-02-12 10:37:36 +0100422 __disable_irq_nosync(irq);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700423}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700424EXPORT_SYMBOL(disable_irq_nosync);
425
426/**
427 * disable_irq - disable an irq and wait for completion
428 * @irq: Interrupt to disable
429 *
430 * Disable the selected interrupt line. Enables and Disables are
431 * nested.
432 * This function waits for any pending IRQ handlers for this interrupt
433 * to complete before returning. If you use this function while
434 * holding a resource the IRQ handler may need you will deadlock.
435 *
436 * This function may be called - with care - from IRQ context.
437 */
438void disable_irq(unsigned int irq)
439{
Thomas Gleixner02725e72011-02-12 10:37:36 +0100440 if (!__disable_irq_nosync(irq))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700441 synchronize_irq(irq);
442}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700443EXPORT_SYMBOL(disable_irq);
444
Rafael J. Wysocki0a0c5162009-03-16 22:33:49 +0100445void __enable_irq(struct irq_desc *desc, unsigned int irq, bool resume)
Thomas Gleixner1adb0852008-04-28 17:01:56 +0200446{
Thomas Gleixnerdc5f2192011-02-04 13:19:20 +0100447 if (resume) {
Thomas Gleixnerc531e832011-02-08 12:44:58 +0100448 if (!(desc->istate & IRQS_SUSPENDED)) {
Thomas Gleixnerdc5f2192011-02-04 13:19:20 +0100449 if (!desc->action)
450 return;
451 if (!(desc->action->flags & IRQF_FORCE_RESUME))
452 return;
453 /* Pretend that it got disabled ! */
454 desc->depth++;
455 }
Thomas Gleixnerc531e832011-02-08 12:44:58 +0100456 desc->istate &= ~IRQS_SUSPENDED;
Thomas Gleixnerdc5f2192011-02-04 13:19:20 +0100457 }
Rafael J. Wysocki0a0c5162009-03-16 22:33:49 +0100458
Thomas Gleixner1adb0852008-04-28 17:01:56 +0200459 switch (desc->depth) {
460 case 0:
Rafael J. Wysocki0a0c5162009-03-16 22:33:49 +0100461 err_out:
Arjan van de Venb8c512f2008-07-25 19:45:36 -0700462 WARN(1, KERN_WARNING "Unbalanced enable for IRQ %d\n", irq);
Thomas Gleixner1adb0852008-04-28 17:01:56 +0200463 break;
464 case 1: {
Thomas Gleixnerc531e832011-02-08 12:44:58 +0100465 if (desc->istate & IRQS_SUSPENDED)
Rafael J. Wysocki0a0c5162009-03-16 22:33:49 +0100466 goto err_out;
Thomas Gleixner1adb0852008-04-28 17:01:56 +0200467 /* Prevent probing on this irq: */
Thomas Gleixner1ccb4e62011-02-09 14:44:17 +0100468 irq_settings_set_noprobe(desc);
Thomas Gleixner3aae9942011-02-04 10:17:52 +0100469 irq_enable(desc);
Thomas Gleixner1adb0852008-04-28 17:01:56 +0200470 check_irq_resend(desc, irq);
471 /* fall-through */
472 }
473 default:
474 desc->depth--;
475 }
476}
477
Linus Torvalds1da177e2005-04-16 15:20:36 -0700478/**
479 * enable_irq - enable handling of an irq
480 * @irq: Interrupt to enable
481 *
482 * Undoes the effect of one call to disable_irq(). If this
483 * matches the last disable, processing of interrupts on this
484 * IRQ line is re-enabled.
485 *
Thomas Gleixner70aedd22009-08-13 12:17:48 +0200486 * This function may be called from IRQ context only when
Thomas Gleixner6b8ff312010-10-01 12:58:38 +0200487 * desc->irq_data.chip->bus_lock and desc->chip->bus_sync_unlock are NULL !
Linus Torvalds1da177e2005-04-16 15:20:36 -0700488 */
489void enable_irq(unsigned int irq)
490{
Linus Torvalds1da177e2005-04-16 15:20:36 -0700491 unsigned long flags;
Marc Zyngier31d9d9b2011-09-23 17:03:06 +0100492 struct irq_desc *desc = irq_get_desc_buslock(irq, &flags, IRQ_GET_DESC_CHECK_GLOBAL);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700493
Yinghai Lu7d94f7c2008-08-19 20:50:14 -0700494 if (!desc)
Matthew Wilcoxc2b5a252005-11-03 07:51:18 -0700495 return;
Thomas Gleixner50f7c032011-02-03 13:23:54 +0100496 if (WARN(!desc->irq_data.chip,
497 KERN_ERR "enable_irq before setup/request_irq: irq %u\n", irq))
Thomas Gleixner02725e72011-02-12 10:37:36 +0100498 goto out;
Thomas Gleixner2656c362010-10-22 14:47:57 +0200499
Rafael J. Wysocki0a0c5162009-03-16 22:33:49 +0100500 __enable_irq(desc, irq, false);
Thomas Gleixner02725e72011-02-12 10:37:36 +0100501out:
502 irq_put_desc_busunlock(desc, flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700503}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700504EXPORT_SYMBOL(enable_irq);
505
David Brownell0c5d1eb2008-10-01 14:46:18 -0700506static int set_irq_wake_real(unsigned int irq, unsigned int on)
Uwe Kleine-König2db87322008-07-23 14:42:25 +0200507{
Yinghai Lu08678b02008-08-19 20:50:05 -0700508 struct irq_desc *desc = irq_to_desc(irq);
Uwe Kleine-König2db87322008-07-23 14:42:25 +0200509 int ret = -ENXIO;
510
Santosh Shilimkar60f96b42011-09-09 13:59:35 +0530511 if (irq_desc_get_chip(desc)->flags & IRQCHIP_SKIP_SET_WAKE)
512 return 0;
513
Thomas Gleixner2f7e99b2010-09-27 12:45:50 +0000514 if (desc->irq_data.chip->irq_set_wake)
515 ret = desc->irq_data.chip->irq_set_wake(&desc->irq_data, on);
Uwe Kleine-König2db87322008-07-23 14:42:25 +0200516
517 return ret;
518}
519
Thomas Gleixnerba9a2332006-06-29 02:24:55 -0700520/**
Thomas Gleixnera0cd9ca2011-02-10 11:36:33 +0100521 * irq_set_irq_wake - control irq power management wakeup
Thomas Gleixnerba9a2332006-06-29 02:24:55 -0700522 * @irq: interrupt to control
523 * @on: enable/disable power management wakeup
524 *
David Brownell15a647e2006-07-30 03:03:08 -0700525 * Enable/disable power management wakeup mode, which is
526 * disabled by default. Enables and disables must match,
527 * just as they match for non-wakeup mode support.
528 *
529 * Wakeup mode lets this IRQ wake the system from sleep
530 * states like "suspend to RAM".
Thomas Gleixnerba9a2332006-06-29 02:24:55 -0700531 */
Thomas Gleixnera0cd9ca2011-02-10 11:36:33 +0100532int irq_set_irq_wake(unsigned int irq, unsigned int on)
Thomas Gleixnerba9a2332006-06-29 02:24:55 -0700533{
Thomas Gleixnerba9a2332006-06-29 02:24:55 -0700534 unsigned long flags;
Marc Zyngier31d9d9b2011-09-23 17:03:06 +0100535 struct irq_desc *desc = irq_get_desc_buslock(irq, &flags, IRQ_GET_DESC_CHECK_GLOBAL);
Uwe Kleine-König2db87322008-07-23 14:42:25 +0200536 int ret = 0;
Thomas Gleixnerba9a2332006-06-29 02:24:55 -0700537
Jesper Juhl13863a62011-06-09 23:14:58 +0200538 if (!desc)
539 return -EINVAL;
540
David Brownell15a647e2006-07-30 03:03:08 -0700541 /* wakeup-capable irqs can be shared between drivers that
542 * don't need to have the same sleep mode behaviors.
543 */
David Brownell15a647e2006-07-30 03:03:08 -0700544 if (on) {
Uwe Kleine-König2db87322008-07-23 14:42:25 +0200545 if (desc->wake_depth++ == 0) {
546 ret = set_irq_wake_real(irq, on);
547 if (ret)
548 desc->wake_depth = 0;
549 else
Thomas Gleixner7f942262011-02-10 19:46:26 +0100550 irqd_set(&desc->irq_data, IRQD_WAKEUP_STATE);
Uwe Kleine-König2db87322008-07-23 14:42:25 +0200551 }
David Brownell15a647e2006-07-30 03:03:08 -0700552 } else {
553 if (desc->wake_depth == 0) {
Arjan van de Ven7a2c4772008-07-25 01:45:54 -0700554 WARN(1, "Unbalanced IRQ %d wake disable\n", irq);
Uwe Kleine-König2db87322008-07-23 14:42:25 +0200555 } else if (--desc->wake_depth == 0) {
556 ret = set_irq_wake_real(irq, on);
557 if (ret)
558 desc->wake_depth = 1;
559 else
Thomas Gleixner7f942262011-02-10 19:46:26 +0100560 irqd_clear(&desc->irq_data, IRQD_WAKEUP_STATE);
Uwe Kleine-König2db87322008-07-23 14:42:25 +0200561 }
David Brownell15a647e2006-07-30 03:03:08 -0700562 }
Thomas Gleixner02725e72011-02-12 10:37:36 +0100563 irq_put_desc_busunlock(desc, flags);
Thomas Gleixnerba9a2332006-06-29 02:24:55 -0700564 return ret;
565}
Thomas Gleixnera0cd9ca2011-02-10 11:36:33 +0100566EXPORT_SYMBOL(irq_set_irq_wake);
Thomas Gleixnerba9a2332006-06-29 02:24:55 -0700567
Linus Torvalds1da177e2005-04-16 15:20:36 -0700568/*
569 * Internal function that tells the architecture code whether a
570 * particular irq has been exclusively allocated or is available
571 * for driver use.
572 */
573int can_request_irq(unsigned int irq, unsigned long irqflags)
574{
Thomas Gleixnercc8c3b72010-03-23 22:40:53 +0100575 unsigned long flags;
Marc Zyngier31d9d9b2011-09-23 17:03:06 +0100576 struct irq_desc *desc = irq_get_desc_lock(irq, &flags, 0);
Thomas Gleixner02725e72011-02-12 10:37:36 +0100577 int canrequest = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700578
Yinghai Lu7d94f7c2008-08-19 20:50:14 -0700579 if (!desc)
580 return 0;
581
Thomas Gleixner02725e72011-02-12 10:37:36 +0100582 if (irq_settings_can_request(desc)) {
Ben Hutchings2779db82013-06-28 02:40:30 +0100583 if (!desc->action ||
584 irqflags & desc->action->flags & IRQF_SHARED)
585 canrequest = 1;
Thomas Gleixner02725e72011-02-12 10:37:36 +0100586 }
587 irq_put_desc_unlock(desc, flags);
588 return canrequest;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700589}
590
David Brownell0c5d1eb2008-10-01 14:46:18 -0700591int __irq_set_trigger(struct irq_desc *desc, unsigned int irq,
Thomas Gleixnerb2ba2c32010-09-27 12:45:47 +0000592 unsigned long flags)
Uwe Kleine-König82736f42008-07-23 21:28:54 -0700593{
Thomas Gleixner6b8ff312010-10-01 12:58:38 +0200594 struct irq_chip *chip = desc->irq_data.chip;
Thomas Gleixnerd4d5e082011-02-10 13:16:14 +0100595 int ret, unmask = 0;
Uwe Kleine-König82736f42008-07-23 21:28:54 -0700596
Thomas Gleixnerb2ba2c32010-09-27 12:45:47 +0000597 if (!chip || !chip->irq_set_type) {
Uwe Kleine-König82736f42008-07-23 21:28:54 -0700598 /*
599 * IRQF_TRIGGER_* but the PIC does not support multiple
600 * flow-types?
601 */
Andrew Morton97fd75b2012-05-31 16:26:07 -0700602 pr_debug("No set_type function for IRQ %d (%s)\n", irq,
Thomas Gleixnerf5d89472012-04-19 12:06:13 +0200603 chip ? (chip->name ? : "unknown") : "unknown");
Uwe Kleine-König82736f42008-07-23 21:28:54 -0700604 return 0;
605 }
606
Thomas Gleixner876dbd42011-02-08 17:28:12 +0100607 flags &= IRQ_TYPE_SENSE_MASK;
Thomas Gleixnerd4d5e082011-02-10 13:16:14 +0100608
609 if (chip->flags & IRQCHIP_SET_TYPE_MASKED) {
Thomas Gleixner32f41252011-03-28 14:10:52 +0200610 if (!irqd_irq_masked(&desc->irq_data))
Thomas Gleixnerd4d5e082011-02-10 13:16:14 +0100611 mask_irq(desc);
Thomas Gleixner32f41252011-03-28 14:10:52 +0200612 if (!irqd_irq_disabled(&desc->irq_data))
Thomas Gleixnerd4d5e082011-02-10 13:16:14 +0100613 unmask = 1;
614 }
615
David Brownellf2b662d2008-12-01 14:31:38 -0800616 /* caller masked out all except trigger mode flags */
Thomas Gleixnerb2ba2c32010-09-27 12:45:47 +0000617 ret = chip->irq_set_type(&desc->irq_data, flags);
Uwe Kleine-König82736f42008-07-23 21:28:54 -0700618
Thomas Gleixner876dbd42011-02-08 17:28:12 +0100619 switch (ret) {
620 case IRQ_SET_MASK_OK:
621 irqd_clear(&desc->irq_data, IRQD_TRIGGER_MASK);
622 irqd_set(&desc->irq_data, flags);
623
624 case IRQ_SET_MASK_OK_NOCOPY:
625 flags = irqd_get_trigger_type(&desc->irq_data);
626 irq_settings_set_trigger_mask(desc, flags);
627 irqd_clear(&desc->irq_data, IRQD_LEVEL);
628 irq_settings_clr_level(desc);
629 if (flags & IRQ_TYPE_LEVEL_MASK) {
630 irq_settings_set_level(desc);
631 irqd_set(&desc->irq_data, IRQD_LEVEL);
632 }
Thomas Gleixner46732472010-06-07 17:53:51 +0200633
Thomas Gleixnerd4d5e082011-02-10 13:16:14 +0100634 ret = 0;
Thomas Gleixner8fff39e2011-02-21 14:19:42 +0100635 break;
Thomas Gleixner876dbd42011-02-08 17:28:12 +0100636 default:
Andrew Morton97fd75b2012-05-31 16:26:07 -0700637 pr_err("Setting trigger mode %lu for irq %u failed (%pF)\n",
Thomas Gleixner876dbd42011-02-08 17:28:12 +0100638 flags, irq, chip->irq_set_type);
David Brownell0c5d1eb2008-10-01 14:46:18 -0700639 }
Thomas Gleixnerd4d5e082011-02-10 13:16:14 +0100640 if (unmask)
641 unmask_irq(desc);
Uwe Kleine-König82736f42008-07-23 21:28:54 -0700642 return ret;
643}
644
Thomas Gleixner293a7a02012-10-16 15:07:49 -0700645#ifdef CONFIG_HARDIRQS_SW_RESEND
646int irq_set_parent(int irq, int parent_irq)
647{
648 unsigned long flags;
649 struct irq_desc *desc = irq_get_desc_lock(irq, &flags, 0);
650
651 if (!desc)
652 return -EINVAL;
653
654 desc->parent_irq = parent_irq;
655
656 irq_put_desc_unlock(desc, flags);
657 return 0;
658}
659#endif
660
Thomas Gleixnerb25c3402009-08-13 12:17:22 +0200661/*
662 * Default primary interrupt handler for threaded interrupts. Is
663 * assigned as primary handler when request_threaded_irq is called
664 * with handler == NULL. Useful for oneshot interrupts.
665 */
666static irqreturn_t irq_default_primary_handler(int irq, void *dev_id)
667{
668 return IRQ_WAKE_THREAD;
669}
670
Thomas Gleixner399b5da2009-08-13 13:21:38 +0200671/*
672 * Primary handler for nested threaded interrupts. Should never be
673 * called.
674 */
675static irqreturn_t irq_nested_primary_handler(int irq, void *dev_id)
676{
677 WARN(1, "Primary handler called for nested irq %d\n", irq);
678 return IRQ_NONE;
679}
680
Thomas Gleixner3aa551c2009-03-23 18:28:15 +0100681static int irq_wait_for_interrupt(struct irqaction *action)
682{
Ido Yariv550acb12011-12-01 13:55:08 +0200683 set_current_state(TASK_INTERRUPTIBLE);
684
Thomas Gleixner3aa551c2009-03-23 18:28:15 +0100685 while (!kthread_should_stop()) {
Thomas Gleixnerf48fe812009-03-24 11:46:22 +0100686
687 if (test_and_clear_bit(IRQTF_RUNTHREAD,
688 &action->thread_flags)) {
Thomas Gleixner3aa551c2009-03-23 18:28:15 +0100689 __set_current_state(TASK_RUNNING);
690 return 0;
Thomas Gleixnerf48fe812009-03-24 11:46:22 +0100691 }
692 schedule();
Ido Yariv550acb12011-12-01 13:55:08 +0200693 set_current_state(TASK_INTERRUPTIBLE);
Thomas Gleixner3aa551c2009-03-23 18:28:15 +0100694 }
Ido Yariv550acb12011-12-01 13:55:08 +0200695 __set_current_state(TASK_RUNNING);
Thomas Gleixner3aa551c2009-03-23 18:28:15 +0100696 return -1;
697}
698
Thomas Gleixnerb25c3402009-08-13 12:17:22 +0200699/*
700 * Oneshot interrupts keep the irq line masked until the threaded
701 * handler finished. unmask if the interrupt has not been disabled and
702 * is marked MASKED.
703 */
Thomas Gleixnerb5faba22011-02-23 23:52:13 +0000704static void irq_finalize_oneshot(struct irq_desc *desc,
Alexander Gordeevf3f79e32012-03-21 17:22:35 +0100705 struct irqaction *action)
Thomas Gleixnerb25c3402009-08-13 12:17:22 +0200706{
Thomas Gleixnerb5faba22011-02-23 23:52:13 +0000707 if (!(desc->istate & IRQS_ONESHOT))
708 return;
Thomas Gleixner0b1adaa2010-03-09 19:45:54 +0100709again:
Thomas Gleixner3876ec92010-09-27 12:44:35 +0000710 chip_bus_lock(desc);
Thomas Gleixner239007b2009-11-17 16:46:45 +0100711 raw_spin_lock_irq(&desc->lock);
Thomas Gleixner0b1adaa2010-03-09 19:45:54 +0100712
713 /*
714 * Implausible though it may be we need to protect us against
715 * the following scenario:
716 *
717 * The thread is faster done than the hard interrupt handler
718 * on the other CPU. If we unmask the irq line then the
719 * interrupt can come in again and masks the line, leaves due
Thomas Gleixner009b4c32011-02-07 21:48:49 +0100720 * to IRQS_INPROGRESS and the irq line is masked forever.
Thomas Gleixnerb5faba22011-02-23 23:52:13 +0000721 *
722 * This also serializes the state of shared oneshot handlers
723 * versus "desc->threads_onehsot |= action->thread_mask;" in
724 * irq_wake_thread(). See the comment there which explains the
725 * serialization.
Thomas Gleixner0b1adaa2010-03-09 19:45:54 +0100726 */
Thomas Gleixner32f41252011-03-28 14:10:52 +0200727 if (unlikely(irqd_irq_inprogress(&desc->irq_data))) {
Thomas Gleixner0b1adaa2010-03-09 19:45:54 +0100728 raw_spin_unlock_irq(&desc->lock);
Thomas Gleixner3876ec92010-09-27 12:44:35 +0000729 chip_bus_sync_unlock(desc);
Thomas Gleixner0b1adaa2010-03-09 19:45:54 +0100730 cpu_relax();
731 goto again;
732 }
733
Thomas Gleixnerb5faba22011-02-23 23:52:13 +0000734 /*
735 * Now check again, whether the thread should run. Otherwise
736 * we would clear the threads_oneshot bit of this thread which
737 * was just set.
738 */
Alexander Gordeevf3f79e32012-03-21 17:22:35 +0100739 if (test_bit(IRQTF_RUNTHREAD, &action->thread_flags))
Thomas Gleixnerb5faba22011-02-23 23:52:13 +0000740 goto out_unlock;
741
742 desc->threads_oneshot &= ~action->thread_mask;
743
Thomas Gleixner32f41252011-03-28 14:10:52 +0200744 if (!desc->threads_oneshot && !irqd_irq_disabled(&desc->irq_data) &&
745 irqd_irq_masked(&desc->irq_data))
Thomas Gleixner328a4972014-03-13 19:03:51 +0100746 unmask_threaded_irq(desc);
Thomas Gleixner32f41252011-03-28 14:10:52 +0200747
Thomas Gleixnerb5faba22011-02-23 23:52:13 +0000748out_unlock:
Thomas Gleixner239007b2009-11-17 16:46:45 +0100749 raw_spin_unlock_irq(&desc->lock);
Thomas Gleixner3876ec92010-09-27 12:44:35 +0000750 chip_bus_sync_unlock(desc);
Thomas Gleixnerb25c3402009-08-13 12:17:22 +0200751}
752
Bruno Premont61f38262009-07-22 22:22:32 +0200753#ifdef CONFIG_SMP
Thomas Gleixner3aa551c2009-03-23 18:28:15 +0100754/*
Chuansheng Liub04c6442014-02-10 16:13:57 +0800755 * Check whether we need to change the affinity of the interrupt thread.
Thomas Gleixner591d2fb2009-07-21 11:09:39 +0200756 */
757static void
758irq_thread_check_affinity(struct irq_desc *desc, struct irqaction *action)
759{
760 cpumask_var_t mask;
Thomas Gleixner04aa5302012-11-03 11:52:09 +0100761 bool valid = true;
Thomas Gleixner591d2fb2009-07-21 11:09:39 +0200762
763 if (!test_and_clear_bit(IRQTF_AFFINITY, &action->thread_flags))
764 return;
765
766 /*
767 * In case we are out of memory we set IRQTF_AFFINITY again and
768 * try again next time
769 */
770 if (!alloc_cpumask_var(&mask, GFP_KERNEL)) {
771 set_bit(IRQTF_AFFINITY, &action->thread_flags);
772 return;
773 }
774
Thomas Gleixner239007b2009-11-17 16:46:45 +0100775 raw_spin_lock_irq(&desc->lock);
Thomas Gleixner04aa5302012-11-03 11:52:09 +0100776 /*
777 * This code is triggered unconditionally. Check the affinity
778 * mask pointer. For CPU_MASK_OFFSTACK=n this is optimized out.
779 */
780 if (desc->irq_data.affinity)
781 cpumask_copy(mask, desc->irq_data.affinity);
782 else
783 valid = false;
Thomas Gleixner239007b2009-11-17 16:46:45 +0100784 raw_spin_unlock_irq(&desc->lock);
Thomas Gleixner591d2fb2009-07-21 11:09:39 +0200785
Thomas Gleixner04aa5302012-11-03 11:52:09 +0100786 if (valid)
787 set_cpus_allowed_ptr(current, mask);
Thomas Gleixner591d2fb2009-07-21 11:09:39 +0200788 free_cpumask_var(mask);
789}
Bruno Premont61f38262009-07-22 22:22:32 +0200790#else
791static inline void
792irq_thread_check_affinity(struct irq_desc *desc, struct irqaction *action) { }
793#endif
Thomas Gleixner591d2fb2009-07-21 11:09:39 +0200794
795/*
Thomas Gleixner8d32a302011-02-23 23:52:23 +0000796 * Interrupts which are not explicitely requested as threaded
797 * interrupts rely on the implicit bh/preempt disable of the hard irq
798 * context. So we need to disable bh here to avoid deadlocks and other
799 * side effects.
800 */
Sebastian Andrzej Siewior3a43e052011-05-31 08:56:11 +0200801static irqreturn_t
Thomas Gleixner8d32a302011-02-23 23:52:23 +0000802irq_forced_thread_fn(struct irq_desc *desc, struct irqaction *action)
803{
Sebastian Andrzej Siewior3a43e052011-05-31 08:56:11 +0200804 irqreturn_t ret;
805
Thomas Gleixner8d32a302011-02-23 23:52:23 +0000806 local_bh_disable();
Sebastian Andrzej Siewior3a43e052011-05-31 08:56:11 +0200807 ret = action->thread_fn(action->irq, action->dev_id);
Alexander Gordeevf3f79e32012-03-21 17:22:35 +0100808 irq_finalize_oneshot(desc, action);
Thomas Gleixner8d32a302011-02-23 23:52:23 +0000809 local_bh_enable();
Sebastian Andrzej Siewior3a43e052011-05-31 08:56:11 +0200810 return ret;
Thomas Gleixner8d32a302011-02-23 23:52:23 +0000811}
812
813/*
Xie XiuQif788e7b2013-10-18 09:12:04 +0800814 * Interrupts explicitly requested as threaded interrupts want to be
Thomas Gleixner8d32a302011-02-23 23:52:23 +0000815 * preemtible - many of them need to sleep and wait for slow busses to
816 * complete.
817 */
Sebastian Andrzej Siewior3a43e052011-05-31 08:56:11 +0200818static irqreturn_t irq_thread_fn(struct irq_desc *desc,
819 struct irqaction *action)
Thomas Gleixner8d32a302011-02-23 23:52:23 +0000820{
Sebastian Andrzej Siewior3a43e052011-05-31 08:56:11 +0200821 irqreturn_t ret;
822
823 ret = action->thread_fn(action->irq, action->dev_id);
Alexander Gordeevf3f79e32012-03-21 17:22:35 +0100824 irq_finalize_oneshot(desc, action);
Sebastian Andrzej Siewior3a43e052011-05-31 08:56:11 +0200825 return ret;
Thomas Gleixner8d32a302011-02-23 23:52:23 +0000826}
827
Ido Yariv7140ea12011-12-02 18:24:12 +0200828static void wake_threads_waitq(struct irq_desc *desc)
829{
Chuansheng Liuc6856892014-02-24 11:29:50 +0800830 if (atomic_dec_and_test(&desc->threads_active))
Ido Yariv7140ea12011-12-02 18:24:12 +0200831 wake_up(&desc->wait_for_threads);
832}
833
Al Viro67d12142012-06-27 11:07:19 +0400834static void irq_thread_dtor(struct callback_head *unused)
Oleg Nesterov4d1d61a2012-05-11 10:59:08 +1000835{
836 struct task_struct *tsk = current;
837 struct irq_desc *desc;
838 struct irqaction *action;
839
840 if (WARN_ON_ONCE(!(current->flags & PF_EXITING)))
841 return;
842
843 action = kthread_data(tsk);
844
Linus Torvaldsfb21aff2012-05-31 18:47:30 -0700845 pr_err("exiting task \"%s\" (%d) is an active IRQ thread (irq %d)\n",
Alan Cox19af3952012-12-18 14:21:25 -0800846 tsk->comm, tsk->pid, action->irq);
Oleg Nesterov4d1d61a2012-05-11 10:59:08 +1000847
848
849 desc = irq_to_desc(action->irq);
850 /*
851 * If IRQTF_RUNTHREAD is set, we need to decrement
852 * desc->threads_active and wake possible waiters.
853 */
854 if (test_and_clear_bit(IRQTF_RUNTHREAD, &action->thread_flags))
855 wake_threads_waitq(desc);
856
857 /* Prevent a stale desc->threads_oneshot */
858 irq_finalize_oneshot(desc, action);
859}
860
Thomas Gleixner8d32a302011-02-23 23:52:23 +0000861/*
Thomas Gleixner3aa551c2009-03-23 18:28:15 +0100862 * Interrupt handler thread
863 */
864static int irq_thread(void *data)
865{
Al Viro67d12142012-06-27 11:07:19 +0400866 struct callback_head on_exit_work;
Thomas Gleixner3aa551c2009-03-23 18:28:15 +0100867 struct irqaction *action = data;
868 struct irq_desc *desc = irq_to_desc(action->irq);
Sebastian Andrzej Siewior3a43e052011-05-31 08:56:11 +0200869 irqreturn_t (*handler_fn)(struct irq_desc *desc,
870 struct irqaction *action);
Thomas Gleixner3aa551c2009-03-23 18:28:15 +0100871
Alexander Gordeev540b60e2012-03-09 14:59:13 +0100872 if (force_irqthreads && test_bit(IRQTF_FORCED_THREAD,
Thomas Gleixner8d32a302011-02-23 23:52:23 +0000873 &action->thread_flags))
874 handler_fn = irq_forced_thread_fn;
875 else
876 handler_fn = irq_thread_fn;
877
Al Viro41f9d292012-06-26 22:10:04 +0400878 init_task_work(&on_exit_work, irq_thread_dtor);
Oleg Nesterov4d1d61a2012-05-11 10:59:08 +1000879 task_work_add(current, &on_exit_work, false);
Thomas Gleixner3aa551c2009-03-23 18:28:15 +0100880
Sankara Muthukrishnanf3de44e2012-10-31 15:41:23 -0500881 irq_thread_check_affinity(desc, action);
882
Thomas Gleixner3aa551c2009-03-23 18:28:15 +0100883 while (!irq_wait_for_interrupt(action)) {
Ido Yariv7140ea12011-12-02 18:24:12 +0200884 irqreturn_t action_ret;
Thomas Gleixner3aa551c2009-03-23 18:28:15 +0100885
Thomas Gleixner591d2fb2009-07-21 11:09:39 +0200886 irq_thread_check_affinity(desc, action);
887
Ido Yariv7140ea12011-12-02 18:24:12 +0200888 action_ret = handler_fn(desc, action);
Thomas Gleixner1e77d0a2013-03-07 14:53:45 +0100889 if (action_ret == IRQ_HANDLED)
890 atomic_inc(&desc->threads_handled);
Thomas Gleixner3aa551c2009-03-23 18:28:15 +0100891
Ido Yariv7140ea12011-12-02 18:24:12 +0200892 wake_threads_waitq(desc);
Thomas Gleixner3aa551c2009-03-23 18:28:15 +0100893 }
894
Ido Yariv7140ea12011-12-02 18:24:12 +0200895 /*
896 * This is the regular exit path. __free_irq() is stopping the
897 * thread via kthread_stop() after calling
898 * synchronize_irq(). So neither IRQTF_RUNTHREAD nor the
Thomas Gleixnere04268b2012-03-15 22:55:21 +0100899 * oneshot mask bit can be set. We cannot verify that as we
900 * cannot touch the oneshot mask at this point anymore as
901 * __setup_irq() might have given out currents thread_mask
902 * again.
Thomas Gleixner3aa551c2009-03-23 18:28:15 +0100903 */
Oleg Nesterov4d1d61a2012-05-11 10:59:08 +1000904 task_work_cancel(current, irq_thread_dtor);
Thomas Gleixner3aa551c2009-03-23 18:28:15 +0100905 return 0;
906}
907
Thomas Gleixnera92444c2014-02-15 00:55:19 +0000908/**
909 * irq_wake_thread - wake the irq thread for the action identified by dev_id
910 * @irq: Interrupt line
911 * @dev_id: Device identity for which the thread should be woken
912 *
913 */
914void irq_wake_thread(unsigned int irq, void *dev_id)
915{
916 struct irq_desc *desc = irq_to_desc(irq);
917 struct irqaction *action;
918 unsigned long flags;
919
920 if (!desc || WARN_ON(irq_settings_is_per_cpu_devid(desc)))
921 return;
922
923 raw_spin_lock_irqsave(&desc->lock, flags);
924 for (action = desc->action; action; action = action->next) {
925 if (action->dev_id == dev_id) {
926 if (action->thread)
927 __irq_wake_thread(desc, action);
928 break;
929 }
930 }
931 raw_spin_unlock_irqrestore(&desc->lock, flags);
932}
933EXPORT_SYMBOL_GPL(irq_wake_thread);
934
Thomas Gleixner8d32a302011-02-23 23:52:23 +0000935static void irq_setup_forced_threading(struct irqaction *new)
936{
937 if (!force_irqthreads)
938 return;
939 if (new->flags & (IRQF_NO_THREAD | IRQF_PERCPU | IRQF_ONESHOT))
940 return;
941
942 new->flags |= IRQF_ONESHOT;
943
944 if (!new->thread_fn) {
945 set_bit(IRQTF_FORCED_THREAD, &new->thread_flags);
946 new->thread_fn = new->handler;
947 new->handler = irq_default_primary_handler;
948 }
949}
950
Thomas Gleixnerc1bacba2014-03-08 08:59:58 +0100951static int irq_request_resources(struct irq_desc *desc)
952{
953 struct irq_data *d = &desc->irq_data;
954 struct irq_chip *c = d->chip;
955
956 return c->irq_request_resources ? c->irq_request_resources(d) : 0;
957}
958
959static void irq_release_resources(struct irq_desc *desc)
960{
961 struct irq_data *d = &desc->irq_data;
962 struct irq_chip *c = d->chip;
963
964 if (c->irq_release_resources)
965 c->irq_release_resources(d);
966}
967
Linus Torvalds1da177e2005-04-16 15:20:36 -0700968/*
969 * Internal function to register an irqaction - typically used to
970 * allocate special interrupts that are part of the architecture.
971 */
Thomas Gleixnerd3c60042008-10-16 09:55:00 +0200972static int
Ingo Molnar327ec562009-02-15 11:21:37 +0100973__setup_irq(unsigned int irq, struct irq_desc *desc, struct irqaction *new)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700974{
Ingo Molnarf17c7542009-02-17 20:43:37 +0100975 struct irqaction *old, **old_ptr;
Thomas Gleixnerb5faba22011-02-23 23:52:13 +0000976 unsigned long flags, thread_mask = 0;
Thomas Gleixner3b8249e2011-02-07 16:02:20 +0100977 int ret, nested, shared = 0;
978 cpumask_var_t mask;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700979
Yinghai Lu7d94f7c2008-08-19 20:50:14 -0700980 if (!desc)
Matthew Wilcoxc2b5a252005-11-03 07:51:18 -0700981 return -EINVAL;
982
Thomas Gleixner6b8ff312010-10-01 12:58:38 +0200983 if (desc->irq_data.chip == &no_irq_chip)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700984 return -ENOSYS;
Sebastian Andrzej Siewiorb6873802011-07-11 12:17:31 +0200985 if (!try_module_get(desc->owner))
986 return -ENODEV;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700987
988 /*
Thomas Gleixner399b5da2009-08-13 13:21:38 +0200989 * Check whether the interrupt nests into another interrupt
990 * thread.
Thomas Gleixner3aa551c2009-03-23 18:28:15 +0100991 */
Thomas Gleixner1ccb4e62011-02-09 14:44:17 +0100992 nested = irq_settings_is_nested_thread(desc);
Thomas Gleixner399b5da2009-08-13 13:21:38 +0200993 if (nested) {
Sebastian Andrzej Siewiorb6873802011-07-11 12:17:31 +0200994 if (!new->thread_fn) {
995 ret = -EINVAL;
996 goto out_mput;
997 }
Thomas Gleixner399b5da2009-08-13 13:21:38 +0200998 /*
999 * Replace the primary handler which was provided from
1000 * the driver for non nested interrupt handling by the
1001 * dummy function which warns when called.
1002 */
1003 new->handler = irq_nested_primary_handler;
Thomas Gleixner8d32a302011-02-23 23:52:23 +00001004 } else {
Paul Mundt7f1b1242011-04-07 06:01:44 +09001005 if (irq_settings_can_thread(desc))
1006 irq_setup_forced_threading(new);
Thomas Gleixner399b5da2009-08-13 13:21:38 +02001007 }
1008
1009 /*
1010 * Create a handler thread when a thread function is supplied
1011 * and the interrupt does not nest into another interrupt
1012 * thread.
1013 */
1014 if (new->thread_fn && !nested) {
Thomas Gleixner3aa551c2009-03-23 18:28:15 +01001015 struct task_struct *t;
Ivo Siebenee238712013-06-03 12:12:02 +02001016 static const struct sched_param param = {
1017 .sched_priority = MAX_USER_RT_PRIO/2,
1018 };
Thomas Gleixner3aa551c2009-03-23 18:28:15 +01001019
1020 t = kthread_create(irq_thread, new, "irq/%d-%s", irq,
1021 new->name);
Sebastian Andrzej Siewiorb6873802011-07-11 12:17:31 +02001022 if (IS_ERR(t)) {
1023 ret = PTR_ERR(t);
1024 goto out_mput;
1025 }
Ivo Siebenee238712013-06-03 12:12:02 +02001026
Thomas Pfaffbbfe65c2013-10-11 13:00:40 +02001027 sched_setscheduler_nocheck(t, SCHED_FIFO, &param);
Ivo Siebenee238712013-06-03 12:12:02 +02001028
Thomas Gleixner3aa551c2009-03-23 18:28:15 +01001029 /*
1030 * We keep the reference to the task struct even if
1031 * the thread dies to avoid that the interrupt code
1032 * references an already freed task_struct.
1033 */
1034 get_task_struct(t);
1035 new->thread = t;
Thomas Gleixner04aa5302012-11-03 11:52:09 +01001036 /*
1037 * Tell the thread to set its affinity. This is
1038 * important for shared interrupt handlers as we do
1039 * not invoke setup_affinity() for the secondary
1040 * handlers as everything is already set up. Even for
1041 * interrupts marked with IRQF_NO_BALANCE this is
1042 * correct as we want the thread to move to the cpu(s)
1043 * on which the requesting code placed the interrupt.
1044 */
1045 set_bit(IRQTF_AFFINITY, &new->thread_flags);
Thomas Gleixner3aa551c2009-03-23 18:28:15 +01001046 }
1047
Thomas Gleixner3b8249e2011-02-07 16:02:20 +01001048 if (!alloc_cpumask_var(&mask, GFP_KERNEL)) {
1049 ret = -ENOMEM;
1050 goto out_thread;
1051 }
1052
Thomas Gleixner3aa551c2009-03-23 18:28:15 +01001053 /*
Thomas Gleixnerdc9b2292012-07-13 19:29:45 +02001054 * Drivers are often written to work w/o knowledge about the
1055 * underlying irq chip implementation, so a request for a
1056 * threaded irq without a primary hard irq context handler
1057 * requires the ONESHOT flag to be set. Some irq chips like
1058 * MSI based interrupts are per se one shot safe. Check the
1059 * chip flags, so we can avoid the unmask dance at the end of
1060 * the threaded handler for those.
1061 */
1062 if (desc->irq_data.chip->flags & IRQCHIP_ONESHOT_SAFE)
1063 new->flags &= ~IRQF_ONESHOT;
1064
1065 /*
Linus Torvalds1da177e2005-04-16 15:20:36 -07001066 * The following block of code has to be executed atomically
1067 */
Thomas Gleixner239007b2009-11-17 16:46:45 +01001068 raw_spin_lock_irqsave(&desc->lock, flags);
Ingo Molnarf17c7542009-02-17 20:43:37 +01001069 old_ptr = &desc->action;
1070 old = *old_ptr;
Ingo Molnar06fcb0c2006-06-29 02:24:40 -07001071 if (old) {
Thomas Gleixnere76de9f2006-06-29 02:24:56 -07001072 /*
1073 * Can't share interrupts unless both agree to and are
1074 * the same type (level, edge, polarity). So both flag
Thomas Gleixner3cca53b2006-07-01 19:29:31 -07001075 * fields must have IRQF_SHARED set and the bits which
Thomas Gleixner9d591ed2011-02-23 23:52:16 +00001076 * set the trigger type must match. Also all must
1077 * agree on ONESHOT.
Thomas Gleixnere76de9f2006-06-29 02:24:56 -07001078 */
Thomas Gleixner3cca53b2006-07-01 19:29:31 -07001079 if (!((old->flags & new->flags) & IRQF_SHARED) ||
Thomas Gleixner9d591ed2011-02-23 23:52:16 +00001080 ((old->flags ^ new->flags) & IRQF_TRIGGER_MASK) ||
Thomas Gleixnerf5d89472012-04-19 12:06:13 +02001081 ((old->flags ^ new->flags) & IRQF_ONESHOT))
Dimitri Sivanichf5163422006-03-25 03:08:23 -08001082 goto mismatch;
1083
Dimitri Sivanichf5163422006-03-25 03:08:23 -08001084 /* All handlers must agree on per-cpuness */
Thomas Gleixner3cca53b2006-07-01 19:29:31 -07001085 if ((old->flags & IRQF_PERCPU) !=
1086 (new->flags & IRQF_PERCPU))
Dimitri Sivanichf5163422006-03-25 03:08:23 -08001087 goto mismatch;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001088
1089 /* add new interrupt at end of irq queue */
1090 do {
Thomas Gleixner52abb702012-03-06 23:18:54 +01001091 /*
1092 * Or all existing action->thread_mask bits,
1093 * so we can find the next zero bit for this
1094 * new action.
1095 */
Thomas Gleixnerb5faba22011-02-23 23:52:13 +00001096 thread_mask |= old->thread_mask;
Ingo Molnarf17c7542009-02-17 20:43:37 +01001097 old_ptr = &old->next;
1098 old = *old_ptr;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001099 } while (old);
1100 shared = 1;
1101 }
1102
Thomas Gleixnerb5faba22011-02-23 23:52:13 +00001103 /*
Thomas Gleixner52abb702012-03-06 23:18:54 +01001104 * Setup the thread mask for this irqaction for ONESHOT. For
1105 * !ONESHOT irqs the thread mask is 0 so we can avoid a
1106 * conditional in irq_wake_thread().
Thomas Gleixnerb5faba22011-02-23 23:52:13 +00001107 */
Thomas Gleixner52abb702012-03-06 23:18:54 +01001108 if (new->flags & IRQF_ONESHOT) {
1109 /*
1110 * Unlikely to have 32 resp 64 irqs sharing one line,
1111 * but who knows.
1112 */
1113 if (thread_mask == ~0UL) {
1114 ret = -EBUSY;
1115 goto out_mask;
1116 }
1117 /*
1118 * The thread_mask for the action is or'ed to
1119 * desc->thread_active to indicate that the
1120 * IRQF_ONESHOT thread handler has been woken, but not
1121 * yet finished. The bit is cleared when a thread
1122 * completes. When all threads of a shared interrupt
1123 * line have completed desc->threads_active becomes
1124 * zero and the interrupt line is unmasked. See
1125 * handle.c:irq_wake_thread() for further information.
1126 *
1127 * If no thread is woken by primary (hard irq context)
1128 * interrupt handlers, then desc->threads_active is
1129 * also checked for zero to unmask the irq line in the
1130 * affected hard irq flow handlers
1131 * (handle_[fasteoi|level]_irq).
1132 *
1133 * The new action gets the first zero bit of
1134 * thread_mask assigned. See the loop above which or's
1135 * all existing action->thread_mask bits.
1136 */
1137 new->thread_mask = 1 << ffz(thread_mask);
Thomas Gleixner1c6c6952012-04-19 10:35:17 +02001138
Thomas Gleixnerdc9b2292012-07-13 19:29:45 +02001139 } else if (new->handler == irq_default_primary_handler &&
1140 !(desc->irq_data.chip->flags & IRQCHIP_ONESHOT_SAFE)) {
Thomas Gleixner1c6c6952012-04-19 10:35:17 +02001141 /*
1142 * The interrupt was requested with handler = NULL, so
1143 * we use the default primary handler for it. But it
1144 * does not have the oneshot flag set. In combination
1145 * with level interrupts this is deadly, because the
1146 * default primary handler just wakes the thread, then
1147 * the irq lines is reenabled, but the device still
1148 * has the level irq asserted. Rinse and repeat....
1149 *
1150 * While this works for edge type interrupts, we play
1151 * it safe and reject unconditionally because we can't
1152 * say for sure which type this interrupt really
1153 * has. The type flags are unreliable as the
1154 * underlying chip implementation can override them.
1155 */
Andrew Morton97fd75b2012-05-31 16:26:07 -07001156 pr_err("Threaded irq requested with handler=NULL and !ONESHOT for irq %d\n",
Thomas Gleixner1c6c6952012-04-19 10:35:17 +02001157 irq);
1158 ret = -EINVAL;
1159 goto out_mask;
Thomas Gleixnerb5faba22011-02-23 23:52:13 +00001160 }
Thomas Gleixnerb5faba22011-02-23 23:52:13 +00001161
Linus Torvalds1da177e2005-04-16 15:20:36 -07001162 if (!shared) {
Thomas Gleixnerc1bacba2014-03-08 08:59:58 +01001163 ret = irq_request_resources(desc);
1164 if (ret) {
1165 pr_err("Failed to request resources for %s (irq %d) on irqchip %s\n",
1166 new->name, irq, desc->irq_data.chip->name);
1167 goto out_mask;
1168 }
1169
Thomas Gleixner3aa551c2009-03-23 18:28:15 +01001170 init_waitqueue_head(&desc->wait_for_threads);
1171
Uwe Kleine-König82736f42008-07-23 21:28:54 -07001172 /* Setup the type (level, edge polarity) if configured: */
1173 if (new->flags & IRQF_TRIGGER_MASK) {
David Brownellf2b662d2008-12-01 14:31:38 -08001174 ret = __irq_set_trigger(desc, irq,
1175 new->flags & IRQF_TRIGGER_MASK);
Uwe Kleine-König82736f42008-07-23 21:28:54 -07001176
Thomas Gleixner3aa551c2009-03-23 18:28:15 +01001177 if (ret)
Thomas Gleixner3b8249e2011-02-07 16:02:20 +01001178 goto out_mask;
Thomas Gleixner091738a2011-02-14 20:16:43 +01001179 }
Ahmed S. Darwishf75d2222007-05-08 00:27:55 -07001180
Thomas Gleixner009b4c32011-02-07 21:48:49 +01001181 desc->istate &= ~(IRQS_AUTODETECT | IRQS_SPURIOUS_DISABLED | \
Thomas Gleixner32f41252011-03-28 14:10:52 +02001182 IRQS_ONESHOT | IRQS_WAITING);
1183 irqd_clear(&desc->irq_data, IRQD_IRQ_INPROGRESS);
Thomas Gleixner94d39e12006-06-29 02:24:50 -07001184
Thomas Gleixnera0056772011-02-08 17:11:03 +01001185 if (new->flags & IRQF_PERCPU) {
1186 irqd_set(&desc->irq_data, IRQD_PER_CPU);
1187 irq_settings_set_per_cpu(desc);
1188 }
Thomas Gleixner6a58fb32011-02-08 15:40:05 +01001189
Thomas Gleixnerb25c3402009-08-13 12:17:22 +02001190 if (new->flags & IRQF_ONESHOT)
Thomas Gleixner3d67bae2011-02-07 21:02:10 +01001191 desc->istate |= IRQS_ONESHOT;
Thomas Gleixnerb25c3402009-08-13 12:17:22 +02001192
Thomas Gleixner1ccb4e62011-02-09 14:44:17 +01001193 if (irq_settings_can_autoenable(desc))
Thomas Gleixnerb4bc7242012-02-08 11:57:52 +01001194 irq_startup(desc, true);
Thomas Gleixner46999232011-02-02 21:41:14 +00001195 else
Thomas Gleixnere76de9f2006-06-29 02:24:56 -07001196 /* Undo nested disables: */
1197 desc->depth = 1;
Max Krasnyansky18404752008-05-29 11:02:52 -07001198
Thomas Gleixner612e3682008-11-07 13:58:46 +01001199 /* Exclude IRQ from balancing if requested */
Thomas Gleixnera0056772011-02-08 17:11:03 +01001200 if (new->flags & IRQF_NOBALANCING) {
1201 irq_settings_set_no_balancing(desc);
1202 irqd_set(&desc->irq_data, IRQD_NO_BALANCING);
1203 }
Thomas Gleixner612e3682008-11-07 13:58:46 +01001204
Max Krasnyansky18404752008-05-29 11:02:52 -07001205 /* Set default affinity mask once everything is setup */
Thomas Gleixner3b8249e2011-02-07 16:02:20 +01001206 setup_affinity(irq, desc, mask);
David Brownell0c5d1eb2008-10-01 14:46:18 -07001207
Thomas Gleixner876dbd42011-02-08 17:28:12 +01001208 } else if (new->flags & IRQF_TRIGGER_MASK) {
1209 unsigned int nmsk = new->flags & IRQF_TRIGGER_MASK;
1210 unsigned int omsk = irq_settings_get_trigger_mask(desc);
1211
1212 if (nmsk != omsk)
1213 /* hope the handler works with current trigger mode */
Andrew Morton97fd75b2012-05-31 16:26:07 -07001214 pr_warning("irq %d uses trigger mode %u; requested %u\n",
Thomas Gleixner876dbd42011-02-08 17:28:12 +01001215 irq, nmsk, omsk);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001216 }
Uwe Kleine-König82736f42008-07-23 21:28:54 -07001217
Thomas Gleixner69ab8492009-08-17 14:07:16 +02001218 new->irq = irq;
Ingo Molnarf17c7542009-02-17 20:43:37 +01001219 *old_ptr = new;
Uwe Kleine-König82736f42008-07-23 21:28:54 -07001220
Linus Torvalds8528b0f2007-01-23 14:16:31 -08001221 /* Reset broken irq detection when installing new handler */
1222 desc->irq_count = 0;
1223 desc->irqs_unhandled = 0;
Thomas Gleixner1adb0852008-04-28 17:01:56 +02001224
1225 /*
1226 * Check whether we disabled the irq via the spurious handler
1227 * before. Reenable it and give it another chance.
1228 */
Thomas Gleixner7acdd532011-02-07 20:40:54 +01001229 if (shared && (desc->istate & IRQS_SPURIOUS_DISABLED)) {
1230 desc->istate &= ~IRQS_SPURIOUS_DISABLED;
Rafael J. Wysocki0a0c5162009-03-16 22:33:49 +01001231 __enable_irq(desc, irq, false);
Thomas Gleixner1adb0852008-04-28 17:01:56 +02001232 }
1233
Thomas Gleixner239007b2009-11-17 16:46:45 +01001234 raw_spin_unlock_irqrestore(&desc->lock, flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001235
Thomas Gleixner69ab8492009-08-17 14:07:16 +02001236 /*
1237 * Strictly no need to wake it up, but hung_task complains
1238 * when no hard interrupt wakes the thread up.
1239 */
1240 if (new->thread)
1241 wake_up_process(new->thread);
1242
Yinghai Lu2c6927a2008-08-19 20:50:11 -07001243 register_irq_proc(irq, desc);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001244 new->dir = NULL;
1245 register_handler_proc(irq, new);
Xiaotian Feng4f5058c2011-04-02 19:39:35 +08001246 free_cpumask_var(mask);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001247
1248 return 0;
Dimitri Sivanichf5163422006-03-25 03:08:23 -08001249
1250mismatch:
Thomas Gleixner3cca53b2006-07-01 19:29:31 -07001251 if (!(new->flags & IRQF_PROBE_SHARED)) {
Andrew Morton97fd75b2012-05-31 16:26:07 -07001252 pr_err("Flags mismatch irq %d. %08x (%s) vs. %08x (%s)\n",
Thomas Gleixnerf5d89472012-04-19 12:06:13 +02001253 irq, new->flags, new->name, old->flags, old->name);
1254#ifdef CONFIG_DEBUG_SHIRQ
Andrew Morton13e87ec2006-04-27 18:39:18 -07001255 dump_stack();
Alan Cox3f050442007-02-12 00:52:04 -08001256#endif
Thomas Gleixnerf5d89472012-04-19 12:06:13 +02001257 }
Thomas Gleixner3aa551c2009-03-23 18:28:15 +01001258 ret = -EBUSY;
1259
Thomas Gleixner3b8249e2011-02-07 16:02:20 +01001260out_mask:
Dan Carpenter1c389792011-03-17 14:43:07 +03001261 raw_spin_unlock_irqrestore(&desc->lock, flags);
Thomas Gleixner3b8249e2011-02-07 16:02:20 +01001262 free_cpumask_var(mask);
1263
Thomas Gleixner3aa551c2009-03-23 18:28:15 +01001264out_thread:
Thomas Gleixner3aa551c2009-03-23 18:28:15 +01001265 if (new->thread) {
1266 struct task_struct *t = new->thread;
1267
1268 new->thread = NULL;
Alexander Gordeev05d74ef2012-03-09 14:59:40 +01001269 kthread_stop(t);
Thomas Gleixner3aa551c2009-03-23 18:28:15 +01001270 put_task_struct(t);
1271 }
Sebastian Andrzej Siewiorb6873802011-07-11 12:17:31 +02001272out_mput:
1273 module_put(desc->owner);
Thomas Gleixner3aa551c2009-03-23 18:28:15 +01001274 return ret;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001275}
1276
1277/**
Thomas Gleixnerd3c60042008-10-16 09:55:00 +02001278 * setup_irq - setup an interrupt
1279 * @irq: Interrupt line to setup
1280 * @act: irqaction for the interrupt
1281 *
1282 * Used to statically setup interrupts in the early boot process.
1283 */
1284int setup_irq(unsigned int irq, struct irqaction *act)
1285{
David Daney986c0112011-02-09 16:04:25 -08001286 int retval;
Thomas Gleixnerd3c60042008-10-16 09:55:00 +02001287 struct irq_desc *desc = irq_to_desc(irq);
1288
Marc Zyngier31d9d9b2011-09-23 17:03:06 +01001289 if (WARN_ON(irq_settings_is_per_cpu_devid(desc)))
1290 return -EINVAL;
David Daney986c0112011-02-09 16:04:25 -08001291 chip_bus_lock(desc);
1292 retval = __setup_irq(irq, desc, act);
1293 chip_bus_sync_unlock(desc);
1294
1295 return retval;
Thomas Gleixnerd3c60042008-10-16 09:55:00 +02001296}
Magnus Dammeb53b4e2009-03-12 21:05:59 +09001297EXPORT_SYMBOL_GPL(setup_irq);
Thomas Gleixnerd3c60042008-10-16 09:55:00 +02001298
Marc Zyngier31d9d9b2011-09-23 17:03:06 +01001299/*
Magnus Dammcbf94f02009-03-12 21:05:51 +09001300 * Internal function to unregister an irqaction - used to free
1301 * regular and special interrupts that are part of the architecture.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001302 */
Magnus Dammcbf94f02009-03-12 21:05:51 +09001303static struct irqaction *__free_irq(unsigned int irq, void *dev_id)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001304{
Thomas Gleixnerd3c60042008-10-16 09:55:00 +02001305 struct irq_desc *desc = irq_to_desc(irq);
Ingo Molnarf17c7542009-02-17 20:43:37 +01001306 struct irqaction *action, **action_ptr;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001307 unsigned long flags;
1308
Ingo Molnarae88a232009-02-15 11:29:50 +01001309 WARN(in_interrupt(), "Trying to free IRQ %d from IRQ context!\n", irq);
Yinghai Lu7d94f7c2008-08-19 20:50:14 -07001310
Yinghai Lu7d94f7c2008-08-19 20:50:14 -07001311 if (!desc)
Magnus Dammf21cfb22009-03-12 21:05:42 +09001312 return NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001313
Thomas Gleixner239007b2009-11-17 16:46:45 +01001314 raw_spin_lock_irqsave(&desc->lock, flags);
Ingo Molnarae88a232009-02-15 11:29:50 +01001315
1316 /*
1317 * There can be multiple actions per IRQ descriptor, find the right
1318 * one based on the dev_id:
1319 */
Ingo Molnarf17c7542009-02-17 20:43:37 +01001320 action_ptr = &desc->action;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001321 for (;;) {
Ingo Molnarf17c7542009-02-17 20:43:37 +01001322 action = *action_ptr;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001323
Ingo Molnarae88a232009-02-15 11:29:50 +01001324 if (!action) {
1325 WARN(1, "Trying to free already-free IRQ %d\n", irq);
Thomas Gleixner239007b2009-11-17 16:46:45 +01001326 raw_spin_unlock_irqrestore(&desc->lock, flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001327
Magnus Dammf21cfb22009-03-12 21:05:42 +09001328 return NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001329 }
Ingo Molnarae88a232009-02-15 11:29:50 +01001330
Ingo Molnar8316e382009-02-17 20:28:29 +01001331 if (action->dev_id == dev_id)
1332 break;
Ingo Molnarf17c7542009-02-17 20:43:37 +01001333 action_ptr = &action->next;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001334 }
Ingo Molnarae88a232009-02-15 11:29:50 +01001335
1336 /* Found it - now remove it from the list of entries: */
Ingo Molnarf17c7542009-02-17 20:43:37 +01001337 *action_ptr = action->next;
Ingo Molnarae88a232009-02-15 11:29:50 +01001338
Ingo Molnarae88a232009-02-15 11:29:50 +01001339 /* If this was the last handler, shut down the IRQ line: */
Thomas Gleixnerc1bacba2014-03-08 08:59:58 +01001340 if (!desc->action) {
Thomas Gleixner46999232011-02-02 21:41:14 +00001341 irq_shutdown(desc);
Thomas Gleixnerc1bacba2014-03-08 08:59:58 +01001342 irq_release_resources(desc);
1343 }
Thomas Gleixner3aa551c2009-03-23 18:28:15 +01001344
Peter P Waskiewicz Jre7a297b2010-04-30 14:44:50 -07001345#ifdef CONFIG_SMP
1346 /* make sure affinity_hint is cleaned up */
1347 if (WARN_ON_ONCE(desc->affinity_hint))
1348 desc->affinity_hint = NULL;
1349#endif
1350
Thomas Gleixner239007b2009-11-17 16:46:45 +01001351 raw_spin_unlock_irqrestore(&desc->lock, flags);
Ingo Molnarae88a232009-02-15 11:29:50 +01001352
1353 unregister_handler_proc(irq, action);
1354
1355 /* Make sure it's not being used on another CPU: */
1356 synchronize_irq(irq);
1357
1358#ifdef CONFIG_DEBUG_SHIRQ
1359 /*
1360 * It's a shared IRQ -- the driver ought to be prepared for an IRQ
1361 * event to happen even now it's being freed, so let's make sure that
1362 * is so by doing an extra call to the handler ....
1363 *
1364 * ( We do this after actually deregistering it, to make sure that a
1365 * 'real' IRQ doesn't run in * parallel with our fake. )
1366 */
1367 if (action->flags & IRQF_SHARED) {
1368 local_irq_save(flags);
1369 action->handler(irq, dev_id);
1370 local_irq_restore(flags);
1371 }
1372#endif
Linus Torvalds2d860ad2009-08-13 13:05:10 -07001373
1374 if (action->thread) {
Alexander Gordeev05d74ef2012-03-09 14:59:40 +01001375 kthread_stop(action->thread);
Linus Torvalds2d860ad2009-08-13 13:05:10 -07001376 put_task_struct(action->thread);
1377 }
1378
Sebastian Andrzej Siewiorb6873802011-07-11 12:17:31 +02001379 module_put(desc->owner);
Magnus Dammf21cfb22009-03-12 21:05:42 +09001380 return action;
1381}
Linus Torvalds1da177e2005-04-16 15:20:36 -07001382
1383/**
Magnus Dammcbf94f02009-03-12 21:05:51 +09001384 * remove_irq - free an interrupt
1385 * @irq: Interrupt line to free
1386 * @act: irqaction for the interrupt
1387 *
1388 * Used to remove interrupts statically setup by the early boot process.
1389 */
1390void remove_irq(unsigned int irq, struct irqaction *act)
1391{
Marc Zyngier31d9d9b2011-09-23 17:03:06 +01001392 struct irq_desc *desc = irq_to_desc(irq);
1393
1394 if (desc && !WARN_ON(irq_settings_is_per_cpu_devid(desc)))
1395 __free_irq(irq, act->dev_id);
Magnus Dammcbf94f02009-03-12 21:05:51 +09001396}
Magnus Dammeb53b4e2009-03-12 21:05:59 +09001397EXPORT_SYMBOL_GPL(remove_irq);
Magnus Dammcbf94f02009-03-12 21:05:51 +09001398
1399/**
Magnus Dammf21cfb22009-03-12 21:05:42 +09001400 * free_irq - free an interrupt allocated with request_irq
Linus Torvalds1da177e2005-04-16 15:20:36 -07001401 * @irq: Interrupt line to free
1402 * @dev_id: Device identity to free
1403 *
1404 * Remove an interrupt handler. The handler is removed and if the
1405 * interrupt line is no longer in use by any driver it is disabled.
1406 * On a shared IRQ the caller must ensure the interrupt is disabled
1407 * on the card it drives before calling this function. The function
1408 * does not return until any executing interrupts for this IRQ
1409 * have completed.
1410 *
1411 * This function must not be called from interrupt context.
1412 */
1413void free_irq(unsigned int irq, void *dev_id)
1414{
Thomas Gleixner70aedd22009-08-13 12:17:48 +02001415 struct irq_desc *desc = irq_to_desc(irq);
1416
Marc Zyngier31d9d9b2011-09-23 17:03:06 +01001417 if (!desc || WARN_ON(irq_settings_is_per_cpu_devid(desc)))
Thomas Gleixner70aedd22009-08-13 12:17:48 +02001418 return;
1419
Ben Hutchingscd7eab42011-01-19 21:01:44 +00001420#ifdef CONFIG_SMP
1421 if (WARN_ON(desc->affinity_notify))
1422 desc->affinity_notify = NULL;
1423#endif
1424
Thomas Gleixner3876ec92010-09-27 12:44:35 +00001425 chip_bus_lock(desc);
Magnus Dammcbf94f02009-03-12 21:05:51 +09001426 kfree(__free_irq(irq, dev_id));
Thomas Gleixner3876ec92010-09-27 12:44:35 +00001427 chip_bus_sync_unlock(desc);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001428}
Linus Torvalds1da177e2005-04-16 15:20:36 -07001429EXPORT_SYMBOL(free_irq);
1430
1431/**
Thomas Gleixner3aa551c2009-03-23 18:28:15 +01001432 * request_threaded_irq - allocate an interrupt line
Linus Torvalds1da177e2005-04-16 15:20:36 -07001433 * @irq: Interrupt line to allocate
Thomas Gleixner3aa551c2009-03-23 18:28:15 +01001434 * @handler: Function to be called when the IRQ occurs.
1435 * Primary handler for threaded interrupts
Thomas Gleixnerb25c3402009-08-13 12:17:22 +02001436 * If NULL and thread_fn != NULL the default
1437 * primary handler is installed
Thomas Gleixnerf48fe812009-03-24 11:46:22 +01001438 * @thread_fn: Function called from the irq handler thread
1439 * If NULL, no irq thread is created
Linus Torvalds1da177e2005-04-16 15:20:36 -07001440 * @irqflags: Interrupt type flags
1441 * @devname: An ascii name for the claiming device
1442 * @dev_id: A cookie passed back to the handler function
1443 *
1444 * This call allocates interrupt resources and enables the
1445 * interrupt line and IRQ handling. From the point this
1446 * call is made your handler function may be invoked. Since
1447 * your handler function must clear any interrupt the board
1448 * raises, you must take care both to initialise your hardware
1449 * and to set up the interrupt handler in the right order.
1450 *
Thomas Gleixner3aa551c2009-03-23 18:28:15 +01001451 * If you want to set up a threaded irq handler for your device
Javi Merino6d21af42011-10-26 10:16:11 +01001452 * then you need to supply @handler and @thread_fn. @handler is
Thomas Gleixner3aa551c2009-03-23 18:28:15 +01001453 * still called in hard interrupt context and has to check
1454 * whether the interrupt originates from the device. If yes it
1455 * needs to disable the interrupt on the device and return
Steven Rostedt39a2edd2009-05-12 14:35:54 -04001456 * IRQ_WAKE_THREAD which will wake up the handler thread and run
Thomas Gleixner3aa551c2009-03-23 18:28:15 +01001457 * @thread_fn. This split handler design is necessary to support
1458 * shared interrupts.
1459 *
Linus Torvalds1da177e2005-04-16 15:20:36 -07001460 * Dev_id must be globally unique. Normally the address of the
1461 * device data structure is used as the cookie. Since the handler
1462 * receives this value it makes sense to use it.
1463 *
1464 * If your interrupt is shared you must pass a non NULL dev_id
1465 * as this is required when freeing the interrupt.
1466 *
1467 * Flags:
1468 *
Thomas Gleixner3cca53b2006-07-01 19:29:31 -07001469 * IRQF_SHARED Interrupt is shared
David Brownell0c5d1eb2008-10-01 14:46:18 -07001470 * IRQF_TRIGGER_* Specify active edge(s) or level
Linus Torvalds1da177e2005-04-16 15:20:36 -07001471 *
1472 */
Thomas Gleixner3aa551c2009-03-23 18:28:15 +01001473int request_threaded_irq(unsigned int irq, irq_handler_t handler,
1474 irq_handler_t thread_fn, unsigned long irqflags,
1475 const char *devname, void *dev_id)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001476{
Ingo Molnar06fcb0c2006-06-29 02:24:40 -07001477 struct irqaction *action;
Yinghai Lu08678b02008-08-19 20:50:05 -07001478 struct irq_desc *desc;
Thomas Gleixnerd3c60042008-10-16 09:55:00 +02001479 int retval;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001480
David Brownell470c6622008-12-01 14:31:37 -08001481 /*
Linus Torvalds1da177e2005-04-16 15:20:36 -07001482 * Sanity-check: shared interrupts must pass in a real dev-ID,
1483 * otherwise we'll have trouble later trying to figure out
1484 * which interrupt is which (messes up the interrupt freeing
1485 * logic etc).
1486 */
Thomas Gleixner3cca53b2006-07-01 19:29:31 -07001487 if ((irqflags & IRQF_SHARED) && !dev_id)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001488 return -EINVAL;
Yinghai Lu7d94f7c2008-08-19 20:50:14 -07001489
Yinghai Lucb5bc832008-08-19 20:50:17 -07001490 desc = irq_to_desc(irq);
Yinghai Lu7d94f7c2008-08-19 20:50:14 -07001491 if (!desc)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001492 return -EINVAL;
Yinghai Lu7d94f7c2008-08-19 20:50:14 -07001493
Marc Zyngier31d9d9b2011-09-23 17:03:06 +01001494 if (!irq_settings_can_request(desc) ||
1495 WARN_ON(irq_settings_is_per_cpu_devid(desc)))
Thomas Gleixner6550c772006-06-29 02:24:49 -07001496 return -EINVAL;
Thomas Gleixnerb25c3402009-08-13 12:17:22 +02001497
1498 if (!handler) {
1499 if (!thread_fn)
1500 return -EINVAL;
1501 handler = irq_default_primary_handler;
1502 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001503
Thomas Gleixner45535732009-02-22 23:00:32 +01001504 action = kzalloc(sizeof(struct irqaction), GFP_KERNEL);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001505 if (!action)
1506 return -ENOMEM;
1507
1508 action->handler = handler;
Thomas Gleixner3aa551c2009-03-23 18:28:15 +01001509 action->thread_fn = thread_fn;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001510 action->flags = irqflags;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001511 action->name = devname;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001512 action->dev_id = dev_id;
1513
Thomas Gleixner3876ec92010-09-27 12:44:35 +00001514 chip_bus_lock(desc);
Thomas Gleixnerd3c60042008-10-16 09:55:00 +02001515 retval = __setup_irq(irq, desc, action);
Thomas Gleixner3876ec92010-09-27 12:44:35 +00001516 chip_bus_sync_unlock(desc);
Thomas Gleixner70aedd22009-08-13 12:17:48 +02001517
Anton Vorontsov377bf1e2008-08-21 22:58:28 +04001518 if (retval)
1519 kfree(action);
1520
Thomas Gleixner6d83f942011-02-18 23:27:23 +01001521#ifdef CONFIG_DEBUG_SHIRQ_FIXME
Luis Henriques6ce51c42009-04-01 18:06:35 +01001522 if (!retval && (irqflags & IRQF_SHARED)) {
David Woodhousea304e1b2007-02-12 00:52:00 -08001523 /*
1524 * It's a shared IRQ -- the driver ought to be prepared for it
1525 * to happen immediately, so let's make sure....
Anton Vorontsov377bf1e2008-08-21 22:58:28 +04001526 * We disable the irq to make sure that a 'real' IRQ doesn't
1527 * run in parallel with our fake.
David Woodhousea304e1b2007-02-12 00:52:00 -08001528 */
Jarek Poplawski59845b12007-08-30 23:56:34 -07001529 unsigned long flags;
David Woodhousea304e1b2007-02-12 00:52:00 -08001530
Anton Vorontsov377bf1e2008-08-21 22:58:28 +04001531 disable_irq(irq);
Jarek Poplawski59845b12007-08-30 23:56:34 -07001532 local_irq_save(flags);
Anton Vorontsov377bf1e2008-08-21 22:58:28 +04001533
Jarek Poplawski59845b12007-08-30 23:56:34 -07001534 handler(irq, dev_id);
Anton Vorontsov377bf1e2008-08-21 22:58:28 +04001535
Jarek Poplawski59845b12007-08-30 23:56:34 -07001536 local_irq_restore(flags);
Anton Vorontsov377bf1e2008-08-21 22:58:28 +04001537 enable_irq(irq);
David Woodhousea304e1b2007-02-12 00:52:00 -08001538 }
1539#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -07001540 return retval;
1541}
Thomas Gleixner3aa551c2009-03-23 18:28:15 +01001542EXPORT_SYMBOL(request_threaded_irq);
Marc Zyngierae731f82010-03-15 22:56:33 +00001543
1544/**
1545 * request_any_context_irq - allocate an interrupt line
1546 * @irq: Interrupt line to allocate
1547 * @handler: Function to be called when the IRQ occurs.
1548 * Threaded handler for threaded interrupts.
1549 * @flags: Interrupt type flags
1550 * @name: An ascii name for the claiming device
1551 * @dev_id: A cookie passed back to the handler function
1552 *
1553 * This call allocates interrupt resources and enables the
1554 * interrupt line and IRQ handling. It selects either a
1555 * hardirq or threaded handling method depending on the
1556 * context.
1557 *
1558 * On failure, it returns a negative value. On success,
1559 * it returns either IRQC_IS_HARDIRQ or IRQC_IS_NESTED.
1560 */
1561int request_any_context_irq(unsigned int irq, irq_handler_t handler,
1562 unsigned long flags, const char *name, void *dev_id)
1563{
1564 struct irq_desc *desc = irq_to_desc(irq);
1565 int ret;
1566
1567 if (!desc)
1568 return -EINVAL;
1569
Thomas Gleixner1ccb4e62011-02-09 14:44:17 +01001570 if (irq_settings_is_nested_thread(desc)) {
Marc Zyngierae731f82010-03-15 22:56:33 +00001571 ret = request_threaded_irq(irq, NULL, handler,
1572 flags, name, dev_id);
1573 return !ret ? IRQC_IS_NESTED : ret;
1574 }
1575
1576 ret = request_irq(irq, handler, flags, name, dev_id);
1577 return !ret ? IRQC_IS_HARDIRQ : ret;
1578}
1579EXPORT_SYMBOL_GPL(request_any_context_irq);
Marc Zyngier31d9d9b2011-09-23 17:03:06 +01001580
Marc Zyngier1e7c5fd2011-09-30 10:48:47 +01001581void enable_percpu_irq(unsigned int irq, unsigned int type)
Marc Zyngier31d9d9b2011-09-23 17:03:06 +01001582{
1583 unsigned int cpu = smp_processor_id();
1584 unsigned long flags;
1585 struct irq_desc *desc = irq_get_desc_lock(irq, &flags, IRQ_GET_DESC_CHECK_PERCPU);
1586
1587 if (!desc)
1588 return;
1589
Marc Zyngier1e7c5fd2011-09-30 10:48:47 +01001590 type &= IRQ_TYPE_SENSE_MASK;
1591 if (type != IRQ_TYPE_NONE) {
1592 int ret;
1593
1594 ret = __irq_set_trigger(desc, irq, type);
1595
1596 if (ret) {
Thomas Gleixner32cffdd2011-10-04 18:43:57 +02001597 WARN(1, "failed to set type for IRQ%d\n", irq);
Marc Zyngier1e7c5fd2011-09-30 10:48:47 +01001598 goto out;
1599 }
1600 }
1601
Marc Zyngier31d9d9b2011-09-23 17:03:06 +01001602 irq_percpu_enable(desc, cpu);
Marc Zyngier1e7c5fd2011-09-30 10:48:47 +01001603out:
Marc Zyngier31d9d9b2011-09-23 17:03:06 +01001604 irq_put_desc_unlock(desc, flags);
1605}
Chris Metcalf36a5df82013-02-01 15:04:26 -05001606EXPORT_SYMBOL_GPL(enable_percpu_irq);
Marc Zyngier31d9d9b2011-09-23 17:03:06 +01001607
1608void disable_percpu_irq(unsigned int irq)
1609{
1610 unsigned int cpu = smp_processor_id();
1611 unsigned long flags;
1612 struct irq_desc *desc = irq_get_desc_lock(irq, &flags, IRQ_GET_DESC_CHECK_PERCPU);
1613
1614 if (!desc)
1615 return;
1616
1617 irq_percpu_disable(desc, cpu);
1618 irq_put_desc_unlock(desc, flags);
1619}
Chris Metcalf36a5df82013-02-01 15:04:26 -05001620EXPORT_SYMBOL_GPL(disable_percpu_irq);
Marc Zyngier31d9d9b2011-09-23 17:03:06 +01001621
1622/*
1623 * Internal function to unregister a percpu irqaction.
1624 */
1625static struct irqaction *__free_percpu_irq(unsigned int irq, void __percpu *dev_id)
1626{
1627 struct irq_desc *desc = irq_to_desc(irq);
1628 struct irqaction *action;
1629 unsigned long flags;
1630
1631 WARN(in_interrupt(), "Trying to free IRQ %d from IRQ context!\n", irq);
1632
1633 if (!desc)
1634 return NULL;
1635
1636 raw_spin_lock_irqsave(&desc->lock, flags);
1637
1638 action = desc->action;
1639 if (!action || action->percpu_dev_id != dev_id) {
1640 WARN(1, "Trying to free already-free IRQ %d\n", irq);
1641 goto bad;
1642 }
1643
1644 if (!cpumask_empty(desc->percpu_enabled)) {
1645 WARN(1, "percpu IRQ %d still enabled on CPU%d!\n",
1646 irq, cpumask_first(desc->percpu_enabled));
1647 goto bad;
1648 }
1649
1650 /* Found it - now remove it from the list of entries: */
1651 desc->action = NULL;
1652
1653 raw_spin_unlock_irqrestore(&desc->lock, flags);
1654
1655 unregister_handler_proc(irq, action);
1656
1657 module_put(desc->owner);
1658 return action;
1659
1660bad:
1661 raw_spin_unlock_irqrestore(&desc->lock, flags);
1662 return NULL;
1663}
1664
1665/**
1666 * remove_percpu_irq - free a per-cpu interrupt
1667 * @irq: Interrupt line to free
1668 * @act: irqaction for the interrupt
1669 *
1670 * Used to remove interrupts statically setup by the early boot process.
1671 */
1672void remove_percpu_irq(unsigned int irq, struct irqaction *act)
1673{
1674 struct irq_desc *desc = irq_to_desc(irq);
1675
1676 if (desc && irq_settings_is_per_cpu_devid(desc))
1677 __free_percpu_irq(irq, act->percpu_dev_id);
1678}
1679
1680/**
1681 * free_percpu_irq - free an interrupt allocated with request_percpu_irq
1682 * @irq: Interrupt line to free
1683 * @dev_id: Device identity to free
1684 *
1685 * Remove a percpu interrupt handler. The handler is removed, but
1686 * the interrupt line is not disabled. This must be done on each
1687 * CPU before calling this function. The function does not return
1688 * until any executing interrupts for this IRQ have completed.
1689 *
1690 * This function must not be called from interrupt context.
1691 */
1692void free_percpu_irq(unsigned int irq, void __percpu *dev_id)
1693{
1694 struct irq_desc *desc = irq_to_desc(irq);
1695
1696 if (!desc || !irq_settings_is_per_cpu_devid(desc))
1697 return;
1698
1699 chip_bus_lock(desc);
1700 kfree(__free_percpu_irq(irq, dev_id));
1701 chip_bus_sync_unlock(desc);
1702}
1703
1704/**
1705 * setup_percpu_irq - setup a per-cpu interrupt
1706 * @irq: Interrupt line to setup
1707 * @act: irqaction for the interrupt
1708 *
1709 * Used to statically setup per-cpu interrupts in the early boot process.
1710 */
1711int setup_percpu_irq(unsigned int irq, struct irqaction *act)
1712{
1713 struct irq_desc *desc = irq_to_desc(irq);
1714 int retval;
1715
1716 if (!desc || !irq_settings_is_per_cpu_devid(desc))
1717 return -EINVAL;
1718 chip_bus_lock(desc);
1719 retval = __setup_irq(irq, desc, act);
1720 chip_bus_sync_unlock(desc);
1721
1722 return retval;
1723}
1724
1725/**
1726 * request_percpu_irq - allocate a percpu interrupt line
1727 * @irq: Interrupt line to allocate
1728 * @handler: Function to be called when the IRQ occurs.
1729 * @devname: An ascii name for the claiming device
1730 * @dev_id: A percpu cookie passed back to the handler function
1731 *
1732 * This call allocates interrupt resources, but doesn't
1733 * automatically enable the interrupt. It has to be done on each
1734 * CPU using enable_percpu_irq().
1735 *
1736 * Dev_id must be globally unique. It is a per-cpu variable, and
1737 * the handler gets called with the interrupted CPU's instance of
1738 * that variable.
1739 */
1740int request_percpu_irq(unsigned int irq, irq_handler_t handler,
1741 const char *devname, void __percpu *dev_id)
1742{
1743 struct irqaction *action;
1744 struct irq_desc *desc;
1745 int retval;
1746
1747 if (!dev_id)
1748 return -EINVAL;
1749
1750 desc = irq_to_desc(irq);
1751 if (!desc || !irq_settings_can_request(desc) ||
1752 !irq_settings_is_per_cpu_devid(desc))
1753 return -EINVAL;
1754
1755 action = kzalloc(sizeof(struct irqaction), GFP_KERNEL);
1756 if (!action)
1757 return -ENOMEM;
1758
1759 action->handler = handler;
Marc Zyngier2ed0e642011-11-16 12:27:39 +00001760 action->flags = IRQF_PERCPU | IRQF_NO_SUSPEND;
Marc Zyngier31d9d9b2011-09-23 17:03:06 +01001761 action->name = devname;
1762 action->percpu_dev_id = dev_id;
1763
1764 chip_bus_lock(desc);
1765 retval = __setup_irq(irq, desc, action);
1766 chip_bus_sync_unlock(desc);
1767
1768 if (retval)
1769 kfree(action);
1770
1771 return retval;
1772}