blob: a4c1ab86cd25aa099fcaeab12c935b458b1388d7 [file] [log] [blame]
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
10#include <linux/irq.h>
Thomas Gleixner3aa551c2009-03-23 18:28:15 +010011#include <linux/kthread.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070012#include <linux/module.h>
13#include <linux/random.h>
14#include <linux/interrupt.h>
Robert P. J. Day1aeb2722008-04-29 00:59:25 -070015#include <linux/slab.h>
Thomas Gleixner3aa551c2009-03-23 18:28:15 +010016#include <linux/sched.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070017
18#include "internals.h"
19
Linus Torvalds1da177e2005-04-16 15:20:36 -070020/**
21 * synchronize_irq - wait for pending IRQ handlers (on other CPUs)
Randy Dunlap1e5d5332005-11-07 01:01:06 -080022 * @irq: interrupt number to wait for
Linus Torvalds1da177e2005-04-16 15:20:36 -070023 *
24 * This function waits for any pending IRQ handlers for this interrupt
25 * to complete before returning. If you use this function while
26 * holding a resource the IRQ handler may need you will deadlock.
27 *
28 * This function may be called - with care - from IRQ context.
29 */
30void synchronize_irq(unsigned int irq)
31{
Yinghai Lucb5bc832008-08-19 20:50:17 -070032 struct irq_desc *desc = irq_to_desc(irq);
Herbert Xua98ce5c2007-10-23 11:26:25 +080033 unsigned int status;
Linus Torvalds1da177e2005-04-16 15:20:36 -070034
Yinghai Lu7d94f7c2008-08-19 20:50:14 -070035 if (!desc)
Matthew Wilcoxc2b5a252005-11-03 07:51:18 -070036 return;
37
Herbert Xua98ce5c2007-10-23 11:26:25 +080038 do {
39 unsigned long flags;
40
41 /*
42 * Wait until we're out of the critical section. This might
43 * give the wrong answer due to the lack of memory barriers.
44 */
45 while (desc->status & IRQ_INPROGRESS)
46 cpu_relax();
47
48 /* Ok, that indicated we're done: double-check carefully. */
49 spin_lock_irqsave(&desc->lock, flags);
50 status = desc->status;
51 spin_unlock_irqrestore(&desc->lock, flags);
52
53 /* Oops, that failed? */
54 } while (status & IRQ_INPROGRESS);
Thomas Gleixner3aa551c2009-03-23 18:28:15 +010055
56 /*
57 * We made sure that no hardirq handler is running. Now verify
58 * that no threaded handlers are active.
59 */
60 wait_event(desc->wait_for_threads, !atomic_read(&desc->threads_active));
Linus Torvalds1da177e2005-04-16 15:20:36 -070061}
Linus Torvalds1da177e2005-04-16 15:20:36 -070062EXPORT_SYMBOL(synchronize_irq);
63
Thomas Gleixner3aa551c2009-03-23 18:28:15 +010064#ifdef CONFIG_SMP
65cpumask_var_t irq_default_affinity;
66
Thomas Gleixner771ee3b2007-02-16 01:27:25 -080067/**
68 * irq_can_set_affinity - Check if the affinity of a given irq can be set
69 * @irq: Interrupt to check
70 *
71 */
72int irq_can_set_affinity(unsigned int irq)
73{
Yinghai Lu08678b02008-08-19 20:50:05 -070074 struct irq_desc *desc = irq_to_desc(irq);
Thomas Gleixner771ee3b2007-02-16 01:27:25 -080075
76 if (CHECK_IRQ_PER_CPU(desc->status) || !desc->chip ||
77 !desc->chip->set_affinity)
78 return 0;
79
80 return 1;
81}
82
Thomas Gleixner3aa551c2009-03-23 18:28:15 +010083static void
84irq_set_thread_affinity(struct irq_desc *desc, const struct cpumask *cpumask)
85{
86 struct irqaction *action = desc->action;
87
88 while (action) {
89 if (action->thread)
90 set_cpus_allowed_ptr(action->thread, cpumask);
91 action = action->next;
92 }
93}
94
Thomas Gleixner771ee3b2007-02-16 01:27:25 -080095/**
96 * irq_set_affinity - Set the irq affinity of a given irq
97 * @irq: Interrupt to set affinity
98 * @cpumask: cpumask
99 *
100 */
Rusty Russell0de26522008-12-13 21:20:26 +1030101int irq_set_affinity(unsigned int irq, const struct cpumask *cpumask)
Thomas Gleixner771ee3b2007-02-16 01:27:25 -0800102{
Yinghai Lu08678b02008-08-19 20:50:05 -0700103 struct irq_desc *desc = irq_to_desc(irq);
Thomas Gleixnerf6d87f42008-11-07 13:18:30 +0100104 unsigned long flags;
Thomas Gleixner771ee3b2007-02-16 01:27:25 -0800105
106 if (!desc->chip->set_affinity)
107 return -EINVAL;
108
Thomas Gleixnerf6d87f42008-11-07 13:18:30 +0100109 spin_lock_irqsave(&desc->lock, flags);
110
Thomas Gleixner771ee3b2007-02-16 01:27:25 -0800111#ifdef CONFIG_GENERIC_PENDING_IRQ
venkatesh.pallipadi@intel.com932775a2008-09-05 18:02:15 -0700112 if (desc->status & IRQ_MOVE_PCNTXT || desc->status & IRQ_DISABLED) {
Mike Travis7f7ace02009-01-10 21:58:08 -0800113 cpumask_copy(desc->affinity, cpumask);
Suresh Siddha72b1e222008-07-10 11:16:45 -0700114 desc->chip->set_affinity(irq, cpumask);
Thomas Gleixnerf6d87f42008-11-07 13:18:30 +0100115 } else {
116 desc->status |= IRQ_MOVE_PENDING;
Mike Travis7f7ace02009-01-10 21:58:08 -0800117 cpumask_copy(desc->pending_mask, cpumask);
Thomas Gleixnerf6d87f42008-11-07 13:18:30 +0100118 }
Thomas Gleixner771ee3b2007-02-16 01:27:25 -0800119#else
Mike Travis7f7ace02009-01-10 21:58:08 -0800120 cpumask_copy(desc->affinity, cpumask);
Thomas Gleixner771ee3b2007-02-16 01:27:25 -0800121 desc->chip->set_affinity(irq, cpumask);
122#endif
Thomas Gleixner3aa551c2009-03-23 18:28:15 +0100123 irq_set_thread_affinity(desc, cpumask);
Thomas Gleixnerf6d87f42008-11-07 13:18:30 +0100124 desc->status |= IRQ_AFFINITY_SET;
125 spin_unlock_irqrestore(&desc->lock, flags);
Thomas Gleixner771ee3b2007-02-16 01:27:25 -0800126 return 0;
127}
128
Max Krasnyansky18404752008-05-29 11:02:52 -0700129#ifndef CONFIG_AUTO_IRQ_AFFINITY
130/*
131 * Generic version of the affinity autoselector.
132 */
Hannes Eder548c8932009-02-08 20:24:47 +0100133static int setup_affinity(unsigned int irq, struct irq_desc *desc)
Max Krasnyansky18404752008-05-29 11:02:52 -0700134{
Max Krasnyansky18404752008-05-29 11:02:52 -0700135 if (!irq_can_set_affinity(irq))
136 return 0;
137
Thomas Gleixnerf6d87f42008-11-07 13:18:30 +0100138 /*
139 * Preserve an userspace affinity setup, but make sure that
140 * one of the targets is online.
141 */
Thomas Gleixner612e3682008-11-07 13:58:46 +0100142 if (desc->status & (IRQ_AFFINITY_SET | IRQ_NO_BALANCING)) {
Mike Travis7f7ace02009-01-10 21:58:08 -0800143 if (cpumask_any_and(desc->affinity, cpu_online_mask)
Rusty Russell0de26522008-12-13 21:20:26 +1030144 < nr_cpu_ids)
145 goto set_affinity;
Thomas Gleixnerf6d87f42008-11-07 13:18:30 +0100146 else
147 desc->status &= ~IRQ_AFFINITY_SET;
148 }
149
Mike Travis7f7ace02009-01-10 21:58:08 -0800150 cpumask_and(desc->affinity, cpu_online_mask, irq_default_affinity);
Rusty Russell0de26522008-12-13 21:20:26 +1030151set_affinity:
Mike Travis7f7ace02009-01-10 21:58:08 -0800152 desc->chip->set_affinity(irq, desc->affinity);
Max Krasnyansky18404752008-05-29 11:02:52 -0700153
Max Krasnyansky18404752008-05-29 11:02:52 -0700154 return 0;
155}
Thomas Gleixnerf6d87f42008-11-07 13:18:30 +0100156#else
Hannes Eder548c8932009-02-08 20:24:47 +0100157static inline int setup_affinity(unsigned int irq, struct irq_desc *d)
Thomas Gleixnerf6d87f42008-11-07 13:18:30 +0100158{
159 return irq_select_affinity(irq);
160}
Max Krasnyansky18404752008-05-29 11:02:52 -0700161#endif
162
Thomas Gleixnerf6d87f42008-11-07 13:18:30 +0100163/*
164 * Called when affinity is set via /proc/irq
165 */
166int irq_select_affinity_usr(unsigned int irq)
167{
168 struct irq_desc *desc = irq_to_desc(irq);
169 unsigned long flags;
170 int ret;
171
172 spin_lock_irqsave(&desc->lock, flags);
Hannes Eder548c8932009-02-08 20:24:47 +0100173 ret = setup_affinity(irq, desc);
Thomas Gleixner3aa551c2009-03-23 18:28:15 +0100174 if (!ret)
175 irq_set_thread_affinity(desc, desc->affinity);
Thomas Gleixnerf6d87f42008-11-07 13:18:30 +0100176 spin_unlock_irqrestore(&desc->lock, flags);
177
178 return ret;
179}
180
181#else
Hannes Eder548c8932009-02-08 20:24:47 +0100182static inline int setup_affinity(unsigned int irq, struct irq_desc *desc)
Thomas Gleixnerf6d87f42008-11-07 13:18:30 +0100183{
184 return 0;
185}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700186#endif
187
188/**
189 * disable_irq_nosync - disable an irq without waiting
190 * @irq: Interrupt to disable
191 *
192 * Disable the selected interrupt line. Disables and Enables are
193 * nested.
194 * Unlike disable_irq(), this function does not ensure existing
195 * instances of the IRQ handler have completed before returning.
196 *
197 * This function may be called from IRQ context.
198 */
199void disable_irq_nosync(unsigned int irq)
200{
Thomas Gleixnerd3c60042008-10-16 09:55:00 +0200201 struct irq_desc *desc = irq_to_desc(irq);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700202 unsigned long flags;
203
Yinghai Lu7d94f7c2008-08-19 20:50:14 -0700204 if (!desc)
Matthew Wilcoxc2b5a252005-11-03 07:51:18 -0700205 return;
206
Linus Torvalds1da177e2005-04-16 15:20:36 -0700207 spin_lock_irqsave(&desc->lock, flags);
208 if (!desc->depth++) {
209 desc->status |= IRQ_DISABLED;
Ingo Molnard1bef4e2006-06-29 02:24:36 -0700210 desc->chip->disable(irq);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700211 }
212 spin_unlock_irqrestore(&desc->lock, flags);
213}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700214EXPORT_SYMBOL(disable_irq_nosync);
215
216/**
217 * disable_irq - disable an irq and wait for completion
218 * @irq: Interrupt to disable
219 *
220 * Disable the selected interrupt line. Enables and Disables are
221 * nested.
222 * This function waits for any pending IRQ handlers for this interrupt
223 * to complete before returning. If you use this function while
224 * holding a resource the IRQ handler may need you will deadlock.
225 *
226 * This function may be called - with care - from IRQ context.
227 */
228void disable_irq(unsigned int irq)
229{
Thomas Gleixnerd3c60042008-10-16 09:55:00 +0200230 struct irq_desc *desc = irq_to_desc(irq);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700231
Yinghai Lu7d94f7c2008-08-19 20:50:14 -0700232 if (!desc)
Matthew Wilcoxc2b5a252005-11-03 07:51:18 -0700233 return;
234
Linus Torvalds1da177e2005-04-16 15:20:36 -0700235 disable_irq_nosync(irq);
236 if (desc->action)
237 synchronize_irq(irq);
238}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700239EXPORT_SYMBOL(disable_irq);
240
Thomas Gleixner1adb0852008-04-28 17:01:56 +0200241static void __enable_irq(struct irq_desc *desc, unsigned int irq)
242{
243 switch (desc->depth) {
244 case 0:
Arjan van de Venb8c512f2008-07-25 19:45:36 -0700245 WARN(1, KERN_WARNING "Unbalanced enable for IRQ %d\n", irq);
Thomas Gleixner1adb0852008-04-28 17:01:56 +0200246 break;
247 case 1: {
248 unsigned int status = desc->status & ~IRQ_DISABLED;
249
250 /* Prevent probing on this irq: */
251 desc->status = status | IRQ_NOPROBE;
252 check_irq_resend(desc, irq);
253 /* fall-through */
254 }
255 default:
256 desc->depth--;
257 }
258}
259
Linus Torvalds1da177e2005-04-16 15:20:36 -0700260/**
261 * enable_irq - enable handling of an irq
262 * @irq: Interrupt to enable
263 *
264 * Undoes the effect of one call to disable_irq(). If this
265 * matches the last disable, processing of interrupts on this
266 * IRQ line is re-enabled.
267 *
268 * This function may be called from IRQ context.
269 */
270void enable_irq(unsigned int irq)
271{
Thomas Gleixnerd3c60042008-10-16 09:55:00 +0200272 struct irq_desc *desc = irq_to_desc(irq);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700273 unsigned long flags;
274
Yinghai Lu7d94f7c2008-08-19 20:50:14 -0700275 if (!desc)
Matthew Wilcoxc2b5a252005-11-03 07:51:18 -0700276 return;
277
Linus Torvalds1da177e2005-04-16 15:20:36 -0700278 spin_lock_irqsave(&desc->lock, flags);
Thomas Gleixner1adb0852008-04-28 17:01:56 +0200279 __enable_irq(desc, irq);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700280 spin_unlock_irqrestore(&desc->lock, flags);
281}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700282EXPORT_SYMBOL(enable_irq);
283
David Brownell0c5d1eb2008-10-01 14:46:18 -0700284static int set_irq_wake_real(unsigned int irq, unsigned int on)
Uwe Kleine-König2db87322008-07-23 14:42:25 +0200285{
Yinghai Lu08678b02008-08-19 20:50:05 -0700286 struct irq_desc *desc = irq_to_desc(irq);
Uwe Kleine-König2db87322008-07-23 14:42:25 +0200287 int ret = -ENXIO;
288
289 if (desc->chip->set_wake)
290 ret = desc->chip->set_wake(irq, on);
291
292 return ret;
293}
294
Thomas Gleixnerba9a2332006-06-29 02:24:55 -0700295/**
296 * set_irq_wake - control irq power management wakeup
297 * @irq: interrupt to control
298 * @on: enable/disable power management wakeup
299 *
David Brownell15a647e2006-07-30 03:03:08 -0700300 * Enable/disable power management wakeup mode, which is
301 * disabled by default. Enables and disables must match,
302 * just as they match for non-wakeup mode support.
303 *
304 * Wakeup mode lets this IRQ wake the system from sleep
305 * states like "suspend to RAM".
Thomas Gleixnerba9a2332006-06-29 02:24:55 -0700306 */
307int set_irq_wake(unsigned int irq, unsigned int on)
308{
Yinghai Lu08678b02008-08-19 20:50:05 -0700309 struct irq_desc *desc = irq_to_desc(irq);
Thomas Gleixnerba9a2332006-06-29 02:24:55 -0700310 unsigned long flags;
Uwe Kleine-König2db87322008-07-23 14:42:25 +0200311 int ret = 0;
Thomas Gleixnerba9a2332006-06-29 02:24:55 -0700312
David Brownell15a647e2006-07-30 03:03:08 -0700313 /* wakeup-capable irqs can be shared between drivers that
314 * don't need to have the same sleep mode behaviors.
315 */
Thomas Gleixnerba9a2332006-06-29 02:24:55 -0700316 spin_lock_irqsave(&desc->lock, flags);
David Brownell15a647e2006-07-30 03:03:08 -0700317 if (on) {
Uwe Kleine-König2db87322008-07-23 14:42:25 +0200318 if (desc->wake_depth++ == 0) {
319 ret = set_irq_wake_real(irq, on);
320 if (ret)
321 desc->wake_depth = 0;
322 else
323 desc->status |= IRQ_WAKEUP;
324 }
David Brownell15a647e2006-07-30 03:03:08 -0700325 } else {
326 if (desc->wake_depth == 0) {
Arjan van de Ven7a2c4772008-07-25 01:45:54 -0700327 WARN(1, "Unbalanced IRQ %d wake disable\n", irq);
Uwe Kleine-König2db87322008-07-23 14:42:25 +0200328 } else if (--desc->wake_depth == 0) {
329 ret = set_irq_wake_real(irq, on);
330 if (ret)
331 desc->wake_depth = 1;
332 else
333 desc->status &= ~IRQ_WAKEUP;
334 }
David Brownell15a647e2006-07-30 03:03:08 -0700335 }
Uwe Kleine-König2db87322008-07-23 14:42:25 +0200336
Thomas Gleixnerba9a2332006-06-29 02:24:55 -0700337 spin_unlock_irqrestore(&desc->lock, flags);
338 return ret;
339}
340EXPORT_SYMBOL(set_irq_wake);
341
Linus Torvalds1da177e2005-04-16 15:20:36 -0700342/*
343 * Internal function that tells the architecture code whether a
344 * particular irq has been exclusively allocated or is available
345 * for driver use.
346 */
347int can_request_irq(unsigned int irq, unsigned long irqflags)
348{
Thomas Gleixnerd3c60042008-10-16 09:55:00 +0200349 struct irq_desc *desc = irq_to_desc(irq);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700350 struct irqaction *action;
351
Yinghai Lu7d94f7c2008-08-19 20:50:14 -0700352 if (!desc)
353 return 0;
354
355 if (desc->status & IRQ_NOREQUEST)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700356 return 0;
357
Yinghai Lu08678b02008-08-19 20:50:05 -0700358 action = desc->action;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700359 if (action)
Thomas Gleixner3cca53b2006-07-01 19:29:31 -0700360 if (irqflags & action->flags & IRQF_SHARED)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700361 action = NULL;
362
363 return !action;
364}
365
Thomas Gleixner6a6de9e2006-06-29 02:24:51 -0700366void compat_irq_chip_set_default_handler(struct irq_desc *desc)
367{
368 /*
369 * If the architecture still has not overriden
370 * the flow handler then zap the default. This
371 * should catch incorrect flow-type setting.
372 */
373 if (desc->handle_irq == &handle_bad_irq)
374 desc->handle_irq = NULL;
375}
376
David Brownell0c5d1eb2008-10-01 14:46:18 -0700377int __irq_set_trigger(struct irq_desc *desc, unsigned int irq,
Uwe Kleine-König82736f42008-07-23 21:28:54 -0700378 unsigned long flags)
379{
380 int ret;
David Brownell0c5d1eb2008-10-01 14:46:18 -0700381 struct irq_chip *chip = desc->chip;
Uwe Kleine-König82736f42008-07-23 21:28:54 -0700382
383 if (!chip || !chip->set_type) {
384 /*
385 * IRQF_TRIGGER_* but the PIC does not support multiple
386 * flow-types?
387 */
Mark Nelson3ff68a62008-11-13 21:37:41 +1100388 pr_debug("No set_type function for IRQ %d (%s)\n", irq,
Uwe Kleine-König82736f42008-07-23 21:28:54 -0700389 chip ? (chip->name ? : "unknown") : "unknown");
390 return 0;
391 }
392
David Brownellf2b662d2008-12-01 14:31:38 -0800393 /* caller masked out all except trigger mode flags */
394 ret = chip->set_type(irq, flags);
Uwe Kleine-König82736f42008-07-23 21:28:54 -0700395
396 if (ret)
David Brownellc69ad712008-08-05 13:01:14 -0700397 pr_err("setting trigger mode %d for irq %u failed (%pF)\n",
David Brownellf2b662d2008-12-01 14:31:38 -0800398 (int)flags, irq, chip->set_type);
David Brownell0c5d1eb2008-10-01 14:46:18 -0700399 else {
David Brownellf2b662d2008-12-01 14:31:38 -0800400 if (flags & (IRQ_TYPE_LEVEL_LOW | IRQ_TYPE_LEVEL_HIGH))
401 flags |= IRQ_LEVEL;
David Brownell0c5d1eb2008-10-01 14:46:18 -0700402 /* note that IRQF_TRIGGER_MASK == IRQ_TYPE_SENSE_MASK */
David Brownellf2b662d2008-12-01 14:31:38 -0800403 desc->status &= ~(IRQ_LEVEL | IRQ_TYPE_SENSE_MASK);
404 desc->status |= flags;
David Brownell0c5d1eb2008-10-01 14:46:18 -0700405 }
Uwe Kleine-König82736f42008-07-23 21:28:54 -0700406
407 return ret;
408}
409
Thomas Gleixner3aa551c2009-03-23 18:28:15 +0100410static inline int irq_thread_should_run(struct irqaction *action)
411{
412 return test_and_clear_bit(IRQTF_RUNTHREAD, &action->thread_flags);
413}
414
415static int irq_wait_for_interrupt(struct irqaction *action)
416{
417 while (!kthread_should_stop()) {
418 set_current_state(TASK_INTERRUPTIBLE);
419 if (irq_thread_should_run(action)) {
420 __set_current_state(TASK_RUNNING);
421 return 0;
422 } else
423 schedule();
424 }
425 return -1;
426}
427
428/*
429 * Interrupt handler thread
430 */
431static int irq_thread(void *data)
432{
433 struct sched_param param = { .sched_priority = MAX_USER_RT_PRIO/2, };
434 struct irqaction *action = data;
435 struct irq_desc *desc = irq_to_desc(action->irq);
436 int wake;
437
438 sched_setscheduler(current, SCHED_FIFO, &param);
439 current->irqaction = action;
440
441 while (!irq_wait_for_interrupt(action)) {
442
443 atomic_inc(&desc->threads_active);
444
445 spin_lock_irq(&desc->lock);
446 if (unlikely(desc->status & IRQ_DISABLED)) {
447 /*
448 * CHECKME: We might need a dedicated
449 * IRQ_THREAD_PENDING flag here, which
450 * retriggers the thread in check_irq_resend()
451 * but AFAICT IRQ_PENDING should be fine as it
452 * retriggers the interrupt itself --- tglx
453 */
454 desc->status |= IRQ_PENDING;
455 spin_unlock_irq(&desc->lock);
456 } else {
457 spin_unlock_irq(&desc->lock);
458
459 action->thread_fn(action->irq, action->dev_id);
460 }
461
462 wake = atomic_dec_and_test(&desc->threads_active);
463
464 if (wake && waitqueue_active(&desc->wait_for_threads))
465 wake_up(&desc->wait_for_threads);
466 }
467
468 /*
469 * Clear irqaction. Otherwise exit_irq_thread() would make
470 * fuzz about an active irq thread going into nirvana.
471 */
472 current->irqaction = NULL;
473 return 0;
474}
475
476/*
477 * Called from do_exit()
478 */
479void exit_irq_thread(void)
480{
481 struct task_struct *tsk = current;
482
483 if (!tsk->irqaction)
484 return;
485
486 printk(KERN_ERR
487 "exiting task \"%s\" (%d) is an active IRQ thread (irq %d)\n",
488 tsk->comm ? tsk->comm : "", tsk->pid, tsk->irqaction->irq);
489
490 /*
491 * Set the THREAD DIED flag to prevent further wakeups of the
492 * soon to be gone threaded handler.
493 */
494 set_bit(IRQTF_DIED, &tsk->irqaction->flags);
495}
496
Linus Torvalds1da177e2005-04-16 15:20:36 -0700497/*
498 * Internal function to register an irqaction - typically used to
499 * allocate special interrupts that are part of the architecture.
500 */
Thomas Gleixnerd3c60042008-10-16 09:55:00 +0200501static int
Ingo Molnar327ec562009-02-15 11:21:37 +0100502__setup_irq(unsigned int irq, struct irq_desc *desc, struct irqaction *new)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700503{
Ingo Molnarf17c7542009-02-17 20:43:37 +0100504 struct irqaction *old, **old_ptr;
Andrew Morton8b126b72006-11-14 02:03:23 -0800505 const char *old_name = NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700506 unsigned long flags;
507 int shared = 0;
Uwe Kleine-König82736f42008-07-23 21:28:54 -0700508 int ret;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700509
Yinghai Lu7d94f7c2008-08-19 20:50:14 -0700510 if (!desc)
Matthew Wilcoxc2b5a252005-11-03 07:51:18 -0700511 return -EINVAL;
512
Ingo Molnarf1c26622006-06-29 02:24:57 -0700513 if (desc->chip == &no_irq_chip)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700514 return -ENOSYS;
515 /*
516 * Some drivers like serial.c use request_irq() heavily,
517 * so we have to be careful not to interfere with a
518 * running system.
519 */
Thomas Gleixner3cca53b2006-07-01 19:29:31 -0700520 if (new->flags & IRQF_SAMPLE_RANDOM) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700521 /*
522 * This function might sleep, we want to call it first,
523 * outside of the atomic block.
524 * Yes, this might clear the entropy pool if the wrong
525 * driver is attempted to be loaded, without actually
526 * installing a new handler, but is this really a problem,
527 * only the sysadmin is able to do this.
528 */
529 rand_initialize_irq(irq);
530 }
531
532 /*
Thomas Gleixner3aa551c2009-03-23 18:28:15 +0100533 * Threaded handler ?
534 */
535 if (new->thread_fn) {
536 struct task_struct *t;
537
538 t = kthread_create(irq_thread, new, "irq/%d-%s", irq,
539 new->name);
540 if (IS_ERR(t))
541 return PTR_ERR(t);
542 /*
543 * We keep the reference to the task struct even if
544 * the thread dies to avoid that the interrupt code
545 * references an already freed task_struct.
546 */
547 get_task_struct(t);
548 new->thread = t;
549 wake_up_process(t);
550 }
551
552 /*
Linus Torvalds1da177e2005-04-16 15:20:36 -0700553 * The following block of code has to be executed atomically
554 */
Ingo Molnar06fcb0c2006-06-29 02:24:40 -0700555 spin_lock_irqsave(&desc->lock, flags);
Ingo Molnarf17c7542009-02-17 20:43:37 +0100556 old_ptr = &desc->action;
557 old = *old_ptr;
Ingo Molnar06fcb0c2006-06-29 02:24:40 -0700558 if (old) {
Thomas Gleixnere76de9f2006-06-29 02:24:56 -0700559 /*
560 * Can't share interrupts unless both agree to and are
561 * the same type (level, edge, polarity). So both flag
Thomas Gleixner3cca53b2006-07-01 19:29:31 -0700562 * fields must have IRQF_SHARED set and the bits which
Thomas Gleixnere76de9f2006-06-29 02:24:56 -0700563 * set the trigger type must match.
564 */
Thomas Gleixner3cca53b2006-07-01 19:29:31 -0700565 if (!((old->flags & new->flags) & IRQF_SHARED) ||
Andrew Morton8b126b72006-11-14 02:03:23 -0800566 ((old->flags ^ new->flags) & IRQF_TRIGGER_MASK)) {
567 old_name = old->name;
Dimitri Sivanichf5163422006-03-25 03:08:23 -0800568 goto mismatch;
Andrew Morton8b126b72006-11-14 02:03:23 -0800569 }
Dimitri Sivanichf5163422006-03-25 03:08:23 -0800570
Thomas Gleixner284c6682006-07-03 02:20:32 +0200571#if defined(CONFIG_IRQ_PER_CPU)
Dimitri Sivanichf5163422006-03-25 03:08:23 -0800572 /* All handlers must agree on per-cpuness */
Thomas Gleixner3cca53b2006-07-01 19:29:31 -0700573 if ((old->flags & IRQF_PERCPU) !=
574 (new->flags & IRQF_PERCPU))
Dimitri Sivanichf5163422006-03-25 03:08:23 -0800575 goto mismatch;
576#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -0700577
578 /* add new interrupt at end of irq queue */
579 do {
Ingo Molnarf17c7542009-02-17 20:43:37 +0100580 old_ptr = &old->next;
581 old = *old_ptr;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700582 } while (old);
583 shared = 1;
584 }
585
Linus Torvalds1da177e2005-04-16 15:20:36 -0700586 if (!shared) {
Thomas Gleixner6a6de9e2006-06-29 02:24:51 -0700587 irq_chip_set_defaults(desc->chip);
Thomas Gleixnere76de9f2006-06-29 02:24:56 -0700588
Thomas Gleixner3aa551c2009-03-23 18:28:15 +0100589 init_waitqueue_head(&desc->wait_for_threads);
590
Uwe Kleine-König82736f42008-07-23 21:28:54 -0700591 /* Setup the type (level, edge polarity) if configured: */
592 if (new->flags & IRQF_TRIGGER_MASK) {
David Brownellf2b662d2008-12-01 14:31:38 -0800593 ret = __irq_set_trigger(desc, irq,
594 new->flags & IRQF_TRIGGER_MASK);
Uwe Kleine-König82736f42008-07-23 21:28:54 -0700595
Thomas Gleixner3aa551c2009-03-23 18:28:15 +0100596 if (ret)
597 goto out_thread;
Uwe Kleine-König82736f42008-07-23 21:28:54 -0700598 } else
599 compat_irq_chip_set_default_handler(desc);
Ahmed S. Darwishf75d2222007-05-08 00:27:55 -0700600#if defined(CONFIG_IRQ_PER_CPU)
601 if (new->flags & IRQF_PERCPU)
602 desc->status |= IRQ_PER_CPU;
603#endif
604
Thomas Gleixner94d39e12006-06-29 02:24:50 -0700605 desc->status &= ~(IRQ_AUTODETECT | IRQ_WAITING |
Thomas Gleixner1adb0852008-04-28 17:01:56 +0200606 IRQ_INPROGRESS | IRQ_SPURIOUS_DISABLED);
Thomas Gleixner94d39e12006-06-29 02:24:50 -0700607
608 if (!(desc->status & IRQ_NOAUTOEN)) {
609 desc->depth = 0;
610 desc->status &= ~IRQ_DISABLED;
Pawel MOLL7e6e1782008-09-01 10:12:11 +0100611 desc->chip->startup(irq);
Thomas Gleixnere76de9f2006-06-29 02:24:56 -0700612 } else
613 /* Undo nested disables: */
614 desc->depth = 1;
Max Krasnyansky18404752008-05-29 11:02:52 -0700615
Thomas Gleixner612e3682008-11-07 13:58:46 +0100616 /* Exclude IRQ from balancing if requested */
617 if (new->flags & IRQF_NOBALANCING)
618 desc->status |= IRQ_NO_BALANCING;
619
Max Krasnyansky18404752008-05-29 11:02:52 -0700620 /* Set default affinity mask once everything is setup */
Hannes Eder548c8932009-02-08 20:24:47 +0100621 setup_affinity(irq, desc);
David Brownell0c5d1eb2008-10-01 14:46:18 -0700622
623 } else if ((new->flags & IRQF_TRIGGER_MASK)
624 && (new->flags & IRQF_TRIGGER_MASK)
625 != (desc->status & IRQ_TYPE_SENSE_MASK)) {
626 /* hope the handler works with the actual trigger mode... */
627 pr_warning("IRQ %d uses trigger mode %d; requested %d\n",
628 irq, (int)(desc->status & IRQ_TYPE_SENSE_MASK),
629 (int)(new->flags & IRQF_TRIGGER_MASK));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700630 }
Uwe Kleine-König82736f42008-07-23 21:28:54 -0700631
Ingo Molnarf17c7542009-02-17 20:43:37 +0100632 *old_ptr = new;
Uwe Kleine-König82736f42008-07-23 21:28:54 -0700633
Linus Torvalds8528b0f2007-01-23 14:16:31 -0800634 /* Reset broken irq detection when installing new handler */
635 desc->irq_count = 0;
636 desc->irqs_unhandled = 0;
Thomas Gleixner1adb0852008-04-28 17:01:56 +0200637
638 /*
639 * Check whether we disabled the irq via the spurious handler
640 * before. Reenable it and give it another chance.
641 */
642 if (shared && (desc->status & IRQ_SPURIOUS_DISABLED)) {
643 desc->status &= ~IRQ_SPURIOUS_DISABLED;
644 __enable_irq(desc, irq);
645 }
646
Ingo Molnar06fcb0c2006-06-29 02:24:40 -0700647 spin_unlock_irqrestore(&desc->lock, flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700648
649 new->irq = irq;
Yinghai Lu2c6927a2008-08-19 20:50:11 -0700650 register_irq_proc(irq, desc);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700651 new->dir = NULL;
652 register_handler_proc(irq, new);
653
654 return 0;
Dimitri Sivanichf5163422006-03-25 03:08:23 -0800655
656mismatch:
Alan Cox3f050442007-02-12 00:52:04 -0800657#ifdef CONFIG_DEBUG_SHIRQ
Thomas Gleixner3cca53b2006-07-01 19:29:31 -0700658 if (!(new->flags & IRQF_PROBE_SHARED)) {
Bjorn Helgaase8c4b9d2006-07-01 04:35:45 -0700659 printk(KERN_ERR "IRQ handler type mismatch for IRQ %d\n", irq);
Andrew Morton8b126b72006-11-14 02:03:23 -0800660 if (old_name)
661 printk(KERN_ERR "current handler: %s\n", old_name);
Andrew Morton13e87ec2006-04-27 18:39:18 -0700662 dump_stack();
663 }
Alan Cox3f050442007-02-12 00:52:04 -0800664#endif
Thomas Gleixner3aa551c2009-03-23 18:28:15 +0100665 ret = -EBUSY;
666
667out_thread:
Andrew Morton8b126b72006-11-14 02:03:23 -0800668 spin_unlock_irqrestore(&desc->lock, flags);
Thomas Gleixner3aa551c2009-03-23 18:28:15 +0100669 if (new->thread) {
670 struct task_struct *t = new->thread;
671
672 new->thread = NULL;
673 if (likely(!test_bit(IRQTF_DIED, &new->thread_flags)))
674 kthread_stop(t);
675 put_task_struct(t);
676 }
677 return ret;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700678}
679
680/**
Thomas Gleixnerd3c60042008-10-16 09:55:00 +0200681 * setup_irq - setup an interrupt
682 * @irq: Interrupt line to setup
683 * @act: irqaction for the interrupt
684 *
685 * Used to statically setup interrupts in the early boot process.
686 */
687int setup_irq(unsigned int irq, struct irqaction *act)
688{
689 struct irq_desc *desc = irq_to_desc(irq);
690
691 return __setup_irq(irq, desc, act);
692}
Magnus Dammeb53b4e2009-03-12 21:05:59 +0900693EXPORT_SYMBOL_GPL(setup_irq);
Thomas Gleixnerd3c60042008-10-16 09:55:00 +0200694
Magnus Dammcbf94f02009-03-12 21:05:51 +0900695 /*
696 * Internal function to unregister an irqaction - used to free
697 * regular and special interrupts that are part of the architecture.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700698 */
Magnus Dammcbf94f02009-03-12 21:05:51 +0900699static struct irqaction *__free_irq(unsigned int irq, void *dev_id)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700700{
Thomas Gleixnerd3c60042008-10-16 09:55:00 +0200701 struct irq_desc *desc = irq_to_desc(irq);
Ingo Molnarf17c7542009-02-17 20:43:37 +0100702 struct irqaction *action, **action_ptr;
Thomas Gleixner3aa551c2009-03-23 18:28:15 +0100703 struct task_struct *irqthread;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700704 unsigned long flags;
705
Ingo Molnarae88a232009-02-15 11:29:50 +0100706 WARN(in_interrupt(), "Trying to free IRQ %d from IRQ context!\n", irq);
Yinghai Lu7d94f7c2008-08-19 20:50:14 -0700707
Yinghai Lu7d94f7c2008-08-19 20:50:14 -0700708 if (!desc)
Magnus Dammf21cfb22009-03-12 21:05:42 +0900709 return NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700710
Ingo Molnar06fcb0c2006-06-29 02:24:40 -0700711 spin_lock_irqsave(&desc->lock, flags);
Ingo Molnarae88a232009-02-15 11:29:50 +0100712
713 /*
714 * There can be multiple actions per IRQ descriptor, find the right
715 * one based on the dev_id:
716 */
Ingo Molnarf17c7542009-02-17 20:43:37 +0100717 action_ptr = &desc->action;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700718 for (;;) {
Ingo Molnarf17c7542009-02-17 20:43:37 +0100719 action = *action_ptr;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700720
Ingo Molnarae88a232009-02-15 11:29:50 +0100721 if (!action) {
722 WARN(1, "Trying to free already-free IRQ %d\n", irq);
Ingo Molnar06fcb0c2006-06-29 02:24:40 -0700723 spin_unlock_irqrestore(&desc->lock, flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700724
Magnus Dammf21cfb22009-03-12 21:05:42 +0900725 return NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700726 }
Ingo Molnarae88a232009-02-15 11:29:50 +0100727
Ingo Molnar8316e382009-02-17 20:28:29 +0100728 if (action->dev_id == dev_id)
729 break;
Ingo Molnarf17c7542009-02-17 20:43:37 +0100730 action_ptr = &action->next;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700731 }
Ingo Molnarae88a232009-02-15 11:29:50 +0100732
733 /* Found it - now remove it from the list of entries: */
Ingo Molnarf17c7542009-02-17 20:43:37 +0100734 *action_ptr = action->next;
Ingo Molnarae88a232009-02-15 11:29:50 +0100735
736 /* Currently used only by UML, might disappear one day: */
737#ifdef CONFIG_IRQ_RELEASE_METHOD
738 if (desc->chip->release)
739 desc->chip->release(irq, dev_id);
740#endif
741
742 /* If this was the last handler, shut down the IRQ line: */
743 if (!desc->action) {
744 desc->status |= IRQ_DISABLED;
745 if (desc->chip->shutdown)
746 desc->chip->shutdown(irq);
747 else
748 desc->chip->disable(irq);
749 }
Thomas Gleixner3aa551c2009-03-23 18:28:15 +0100750
751 irqthread = action->thread;
752 action->thread = NULL;
753
Ingo Molnarae88a232009-02-15 11:29:50 +0100754 spin_unlock_irqrestore(&desc->lock, flags);
755
756 unregister_handler_proc(irq, action);
757
758 /* Make sure it's not being used on another CPU: */
759 synchronize_irq(irq);
760
Thomas Gleixner3aa551c2009-03-23 18:28:15 +0100761 if (irqthread) {
762 if (!test_bit(IRQTF_DIED, &action->thread_flags))
763 kthread_stop(irqthread);
764 put_task_struct(irqthread);
765 }
766
Ingo Molnarae88a232009-02-15 11:29:50 +0100767#ifdef CONFIG_DEBUG_SHIRQ
768 /*
769 * It's a shared IRQ -- the driver ought to be prepared for an IRQ
770 * event to happen even now it's being freed, so let's make sure that
771 * is so by doing an extra call to the handler ....
772 *
773 * ( We do this after actually deregistering it, to make sure that a
774 * 'real' IRQ doesn't run in * parallel with our fake. )
775 */
776 if (action->flags & IRQF_SHARED) {
777 local_irq_save(flags);
778 action->handler(irq, dev_id);
779 local_irq_restore(flags);
780 }
781#endif
Magnus Dammf21cfb22009-03-12 21:05:42 +0900782 return action;
783}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700784
785/**
Magnus Dammcbf94f02009-03-12 21:05:51 +0900786 * remove_irq - free an interrupt
787 * @irq: Interrupt line to free
788 * @act: irqaction for the interrupt
789 *
790 * Used to remove interrupts statically setup by the early boot process.
791 */
792void remove_irq(unsigned int irq, struct irqaction *act)
793{
794 __free_irq(irq, act->dev_id);
795}
Magnus Dammeb53b4e2009-03-12 21:05:59 +0900796EXPORT_SYMBOL_GPL(remove_irq);
Magnus Dammcbf94f02009-03-12 21:05:51 +0900797
798/**
Magnus Dammf21cfb22009-03-12 21:05:42 +0900799 * free_irq - free an interrupt allocated with request_irq
Linus Torvalds1da177e2005-04-16 15:20:36 -0700800 * @irq: Interrupt line to free
801 * @dev_id: Device identity to free
802 *
803 * Remove an interrupt handler. The handler is removed and if the
804 * interrupt line is no longer in use by any driver it is disabled.
805 * On a shared IRQ the caller must ensure the interrupt is disabled
806 * on the card it drives before calling this function. The function
807 * does not return until any executing interrupts for this IRQ
808 * have completed.
809 *
810 * This function must not be called from interrupt context.
811 */
812void free_irq(unsigned int irq, void *dev_id)
813{
Magnus Dammcbf94f02009-03-12 21:05:51 +0900814 kfree(__free_irq(irq, dev_id));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700815}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700816EXPORT_SYMBOL(free_irq);
817
818/**
Thomas Gleixner3aa551c2009-03-23 18:28:15 +0100819 * request_threaded_irq - allocate an interrupt line
Linus Torvalds1da177e2005-04-16 15:20:36 -0700820 * @irq: Interrupt line to allocate
Thomas Gleixner3aa551c2009-03-23 18:28:15 +0100821 * @handler: Function to be called when the IRQ occurs.
822 * Primary handler for threaded interrupts
823 * @thread_fn: Function called from the irq handler thread
824 * If NULL, no irq thread is created
Linus Torvalds1da177e2005-04-16 15:20:36 -0700825 * @irqflags: Interrupt type flags
826 * @devname: An ascii name for the claiming device
827 * @dev_id: A cookie passed back to the handler function
828 *
829 * This call allocates interrupt resources and enables the
830 * interrupt line and IRQ handling. From the point this
831 * call is made your handler function may be invoked. Since
832 * your handler function must clear any interrupt the board
833 * raises, you must take care both to initialise your hardware
834 * and to set up the interrupt handler in the right order.
835 *
Thomas Gleixner3aa551c2009-03-23 18:28:15 +0100836 * If you want to set up a threaded irq handler for your device
837 * then you need to supply @handler and @thread_fn. @handler ist
838 * still called in hard interrupt context and has to check
839 * whether the interrupt originates from the device. If yes it
840 * needs to disable the interrupt on the device and return
841 * IRQ_THREAD_WAKE which will wake up the handler thread and run
842 * @thread_fn. This split handler design is necessary to support
843 * shared interrupts.
844 *
Linus Torvalds1da177e2005-04-16 15:20:36 -0700845 * Dev_id must be globally unique. Normally the address of the
846 * device data structure is used as the cookie. Since the handler
847 * receives this value it makes sense to use it.
848 *
849 * If your interrupt is shared you must pass a non NULL dev_id
850 * as this is required when freeing the interrupt.
851 *
852 * Flags:
853 *
Thomas Gleixner3cca53b2006-07-01 19:29:31 -0700854 * IRQF_SHARED Interrupt is shared
855 * IRQF_DISABLED Disable local interrupts while processing
856 * IRQF_SAMPLE_RANDOM The interrupt can be used for entropy
David Brownell0c5d1eb2008-10-01 14:46:18 -0700857 * IRQF_TRIGGER_* Specify active edge(s) or level
Linus Torvalds1da177e2005-04-16 15:20:36 -0700858 *
859 */
Thomas Gleixner3aa551c2009-03-23 18:28:15 +0100860int request_threaded_irq(unsigned int irq, irq_handler_t handler,
861 irq_handler_t thread_fn, unsigned long irqflags,
862 const char *devname, void *dev_id)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700863{
Ingo Molnar06fcb0c2006-06-29 02:24:40 -0700864 struct irqaction *action;
Yinghai Lu08678b02008-08-19 20:50:05 -0700865 struct irq_desc *desc;
Thomas Gleixnerd3c60042008-10-16 09:55:00 +0200866 int retval;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700867
David Brownell470c6622008-12-01 14:31:37 -0800868 /*
869 * handle_IRQ_event() always ignores IRQF_DISABLED except for
870 * the _first_ irqaction (sigh). That can cause oopsing, but
871 * the behavior is classified as "will not fix" so we need to
872 * start nudging drivers away from using that idiom.
873 */
Ingo Molnar327ec562009-02-15 11:21:37 +0100874 if ((irqflags & (IRQF_SHARED|IRQF_DISABLED)) ==
875 (IRQF_SHARED|IRQF_DISABLED)) {
876 pr_warning(
877 "IRQ %d/%s: IRQF_DISABLED is not guaranteed on shared IRQs\n",
878 irq, devname);
879 }
David Brownell470c6622008-12-01 14:31:37 -0800880
Ingo Molnarfbb9ce952006-07-03 00:24:50 -0700881#ifdef CONFIG_LOCKDEP
882 /*
883 * Lockdep wants atomic interrupt handlers:
884 */
Thomas Gleixner38515e92007-02-14 00:33:16 -0800885 irqflags |= IRQF_DISABLED;
Ingo Molnarfbb9ce952006-07-03 00:24:50 -0700886#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -0700887 /*
888 * Sanity-check: shared interrupts must pass in a real dev-ID,
889 * otherwise we'll have trouble later trying to figure out
890 * which interrupt is which (messes up the interrupt freeing
891 * logic etc).
892 */
Thomas Gleixner3cca53b2006-07-01 19:29:31 -0700893 if ((irqflags & IRQF_SHARED) && !dev_id)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700894 return -EINVAL;
Yinghai Lu7d94f7c2008-08-19 20:50:14 -0700895
Yinghai Lucb5bc832008-08-19 20:50:17 -0700896 desc = irq_to_desc(irq);
Yinghai Lu7d94f7c2008-08-19 20:50:14 -0700897 if (!desc)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700898 return -EINVAL;
Yinghai Lu7d94f7c2008-08-19 20:50:14 -0700899
Yinghai Lu08678b02008-08-19 20:50:05 -0700900 if (desc->status & IRQ_NOREQUEST)
Thomas Gleixner6550c772006-06-29 02:24:49 -0700901 return -EINVAL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700902 if (!handler)
903 return -EINVAL;
904
Thomas Gleixner45535732009-02-22 23:00:32 +0100905 action = kzalloc(sizeof(struct irqaction), GFP_KERNEL);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700906 if (!action)
907 return -ENOMEM;
908
909 action->handler = handler;
Thomas Gleixner3aa551c2009-03-23 18:28:15 +0100910 action->thread_fn = thread_fn;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700911 action->flags = irqflags;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700912 action->name = devname;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700913 action->dev_id = dev_id;
914
Thomas Gleixnerd3c60042008-10-16 09:55:00 +0200915 retval = __setup_irq(irq, desc, action);
Anton Vorontsov377bf1e2008-08-21 22:58:28 +0400916 if (retval)
917 kfree(action);
918
David Woodhousea304e1b2007-02-12 00:52:00 -0800919#ifdef CONFIG_DEBUG_SHIRQ
920 if (irqflags & IRQF_SHARED) {
921 /*
922 * It's a shared IRQ -- the driver ought to be prepared for it
923 * to happen immediately, so let's make sure....
Anton Vorontsov377bf1e2008-08-21 22:58:28 +0400924 * We disable the irq to make sure that a 'real' IRQ doesn't
925 * run in parallel with our fake.
David Woodhousea304e1b2007-02-12 00:52:00 -0800926 */
Jarek Poplawski59845b12007-08-30 23:56:34 -0700927 unsigned long flags;
David Woodhousea304e1b2007-02-12 00:52:00 -0800928
Anton Vorontsov377bf1e2008-08-21 22:58:28 +0400929 disable_irq(irq);
Jarek Poplawski59845b12007-08-30 23:56:34 -0700930 local_irq_save(flags);
Anton Vorontsov377bf1e2008-08-21 22:58:28 +0400931
Jarek Poplawski59845b12007-08-30 23:56:34 -0700932 handler(irq, dev_id);
Anton Vorontsov377bf1e2008-08-21 22:58:28 +0400933
Jarek Poplawski59845b12007-08-30 23:56:34 -0700934 local_irq_restore(flags);
Anton Vorontsov377bf1e2008-08-21 22:58:28 +0400935 enable_irq(irq);
David Woodhousea304e1b2007-02-12 00:52:00 -0800936 }
937#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -0700938 return retval;
939}
Thomas Gleixner3aa551c2009-03-23 18:28:15 +0100940EXPORT_SYMBOL(request_threaded_irq);