blob: 7e2e7dd4cd2f70e5d619f893161225e230bf487c [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
Rafael J. Wysocki0a0c5162009-03-16 22:33:49 +0100188void __disable_irq(struct irq_desc *desc, unsigned int irq, bool suspend)
189{
190 if (suspend) {
191 if (!desc->action || (desc->action->flags & IRQF_TIMER))
192 return;
193 desc->status |= IRQ_SUSPENDED;
194 }
195
196 if (!desc->depth++) {
197 desc->status |= IRQ_DISABLED;
198 desc->chip->disable(irq);
199 }
200}
201
Linus Torvalds1da177e2005-04-16 15:20:36 -0700202/**
203 * disable_irq_nosync - disable an irq without waiting
204 * @irq: Interrupt to disable
205 *
206 * Disable the selected interrupt line. Disables and Enables are
207 * nested.
208 * Unlike disable_irq(), this function does not ensure existing
209 * instances of the IRQ handler have completed before returning.
210 *
211 * This function may be called from IRQ context.
212 */
213void disable_irq_nosync(unsigned int irq)
214{
Thomas Gleixnerd3c60042008-10-16 09:55:00 +0200215 struct irq_desc *desc = irq_to_desc(irq);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700216 unsigned long flags;
217
Yinghai Lu7d94f7c2008-08-19 20:50:14 -0700218 if (!desc)
Matthew Wilcoxc2b5a252005-11-03 07:51:18 -0700219 return;
220
Linus Torvalds1da177e2005-04-16 15:20:36 -0700221 spin_lock_irqsave(&desc->lock, flags);
Rafael J. Wysocki0a0c5162009-03-16 22:33:49 +0100222 __disable_irq(desc, irq, false);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700223 spin_unlock_irqrestore(&desc->lock, flags);
224}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700225EXPORT_SYMBOL(disable_irq_nosync);
226
227/**
228 * disable_irq - disable an irq and wait for completion
229 * @irq: Interrupt to disable
230 *
231 * Disable the selected interrupt line. Enables and Disables are
232 * nested.
233 * This function waits for any pending IRQ handlers for this interrupt
234 * to complete before returning. If you use this function while
235 * holding a resource the IRQ handler may need you will deadlock.
236 *
237 * This function may be called - with care - from IRQ context.
238 */
239void disable_irq(unsigned int irq)
240{
Thomas Gleixnerd3c60042008-10-16 09:55:00 +0200241 struct irq_desc *desc = irq_to_desc(irq);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700242
Yinghai Lu7d94f7c2008-08-19 20:50:14 -0700243 if (!desc)
Matthew Wilcoxc2b5a252005-11-03 07:51:18 -0700244 return;
245
Linus Torvalds1da177e2005-04-16 15:20:36 -0700246 disable_irq_nosync(irq);
247 if (desc->action)
248 synchronize_irq(irq);
249}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700250EXPORT_SYMBOL(disable_irq);
251
Rafael J. Wysocki0a0c5162009-03-16 22:33:49 +0100252void __enable_irq(struct irq_desc *desc, unsigned int irq, bool resume)
Thomas Gleixner1adb0852008-04-28 17:01:56 +0200253{
Rafael J. Wysocki0a0c5162009-03-16 22:33:49 +0100254 if (resume)
255 desc->status &= ~IRQ_SUSPENDED;
256
Thomas Gleixner1adb0852008-04-28 17:01:56 +0200257 switch (desc->depth) {
258 case 0:
Rafael J. Wysocki0a0c5162009-03-16 22:33:49 +0100259 err_out:
Arjan van de Venb8c512f2008-07-25 19:45:36 -0700260 WARN(1, KERN_WARNING "Unbalanced enable for IRQ %d\n", irq);
Thomas Gleixner1adb0852008-04-28 17:01:56 +0200261 break;
262 case 1: {
263 unsigned int status = desc->status & ~IRQ_DISABLED;
264
Rafael J. Wysocki0a0c5162009-03-16 22:33:49 +0100265 if (desc->status & IRQ_SUSPENDED)
266 goto err_out;
Thomas Gleixner1adb0852008-04-28 17:01:56 +0200267 /* Prevent probing on this irq: */
268 desc->status = status | IRQ_NOPROBE;
269 check_irq_resend(desc, irq);
270 /* fall-through */
271 }
272 default:
273 desc->depth--;
274 }
275}
276
Linus Torvalds1da177e2005-04-16 15:20:36 -0700277/**
278 * enable_irq - enable handling of an irq
279 * @irq: Interrupt to enable
280 *
281 * Undoes the effect of one call to disable_irq(). If this
282 * matches the last disable, processing of interrupts on this
283 * IRQ line is re-enabled.
284 *
285 * This function may be called from IRQ context.
286 */
287void enable_irq(unsigned int irq)
288{
Thomas Gleixnerd3c60042008-10-16 09:55:00 +0200289 struct irq_desc *desc = irq_to_desc(irq);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700290 unsigned long flags;
291
Yinghai Lu7d94f7c2008-08-19 20:50:14 -0700292 if (!desc)
Matthew Wilcoxc2b5a252005-11-03 07:51:18 -0700293 return;
294
Linus Torvalds1da177e2005-04-16 15:20:36 -0700295 spin_lock_irqsave(&desc->lock, flags);
Rafael J. Wysocki0a0c5162009-03-16 22:33:49 +0100296 __enable_irq(desc, irq, false);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700297 spin_unlock_irqrestore(&desc->lock, flags);
298}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700299EXPORT_SYMBOL(enable_irq);
300
David Brownell0c5d1eb2008-10-01 14:46:18 -0700301static int set_irq_wake_real(unsigned int irq, unsigned int on)
Uwe Kleine-König2db87322008-07-23 14:42:25 +0200302{
Yinghai Lu08678b02008-08-19 20:50:05 -0700303 struct irq_desc *desc = irq_to_desc(irq);
Uwe Kleine-König2db87322008-07-23 14:42:25 +0200304 int ret = -ENXIO;
305
306 if (desc->chip->set_wake)
307 ret = desc->chip->set_wake(irq, on);
308
309 return ret;
310}
311
Thomas Gleixnerba9a2332006-06-29 02:24:55 -0700312/**
313 * set_irq_wake - control irq power management wakeup
314 * @irq: interrupt to control
315 * @on: enable/disable power management wakeup
316 *
David Brownell15a647e2006-07-30 03:03:08 -0700317 * Enable/disable power management wakeup mode, which is
318 * disabled by default. Enables and disables must match,
319 * just as they match for non-wakeup mode support.
320 *
321 * Wakeup mode lets this IRQ wake the system from sleep
322 * states like "suspend to RAM".
Thomas Gleixnerba9a2332006-06-29 02:24:55 -0700323 */
324int set_irq_wake(unsigned int irq, unsigned int on)
325{
Yinghai Lu08678b02008-08-19 20:50:05 -0700326 struct irq_desc *desc = irq_to_desc(irq);
Thomas Gleixnerba9a2332006-06-29 02:24:55 -0700327 unsigned long flags;
Uwe Kleine-König2db87322008-07-23 14:42:25 +0200328 int ret = 0;
Thomas Gleixnerba9a2332006-06-29 02:24:55 -0700329
David Brownell15a647e2006-07-30 03:03:08 -0700330 /* wakeup-capable irqs can be shared between drivers that
331 * don't need to have the same sleep mode behaviors.
332 */
Thomas Gleixnerba9a2332006-06-29 02:24:55 -0700333 spin_lock_irqsave(&desc->lock, flags);
David Brownell15a647e2006-07-30 03:03:08 -0700334 if (on) {
Uwe Kleine-König2db87322008-07-23 14:42:25 +0200335 if (desc->wake_depth++ == 0) {
336 ret = set_irq_wake_real(irq, on);
337 if (ret)
338 desc->wake_depth = 0;
339 else
340 desc->status |= IRQ_WAKEUP;
341 }
David Brownell15a647e2006-07-30 03:03:08 -0700342 } else {
343 if (desc->wake_depth == 0) {
Arjan van de Ven7a2c4772008-07-25 01:45:54 -0700344 WARN(1, "Unbalanced IRQ %d wake disable\n", irq);
Uwe Kleine-König2db87322008-07-23 14:42:25 +0200345 } else if (--desc->wake_depth == 0) {
346 ret = set_irq_wake_real(irq, on);
347 if (ret)
348 desc->wake_depth = 1;
349 else
350 desc->status &= ~IRQ_WAKEUP;
351 }
David Brownell15a647e2006-07-30 03:03:08 -0700352 }
Uwe Kleine-König2db87322008-07-23 14:42:25 +0200353
Thomas Gleixnerba9a2332006-06-29 02:24:55 -0700354 spin_unlock_irqrestore(&desc->lock, flags);
355 return ret;
356}
357EXPORT_SYMBOL(set_irq_wake);
358
Linus Torvalds1da177e2005-04-16 15:20:36 -0700359/*
360 * Internal function that tells the architecture code whether a
361 * particular irq has been exclusively allocated or is available
362 * for driver use.
363 */
364int can_request_irq(unsigned int irq, unsigned long irqflags)
365{
Thomas Gleixnerd3c60042008-10-16 09:55:00 +0200366 struct irq_desc *desc = irq_to_desc(irq);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700367 struct irqaction *action;
368
Yinghai Lu7d94f7c2008-08-19 20:50:14 -0700369 if (!desc)
370 return 0;
371
372 if (desc->status & IRQ_NOREQUEST)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700373 return 0;
374
Yinghai Lu08678b02008-08-19 20:50:05 -0700375 action = desc->action;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700376 if (action)
Thomas Gleixner3cca53b2006-07-01 19:29:31 -0700377 if (irqflags & action->flags & IRQF_SHARED)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700378 action = NULL;
379
380 return !action;
381}
382
Thomas Gleixner6a6de9e2006-06-29 02:24:51 -0700383void compat_irq_chip_set_default_handler(struct irq_desc *desc)
384{
385 /*
386 * If the architecture still has not overriden
387 * the flow handler then zap the default. This
388 * should catch incorrect flow-type setting.
389 */
390 if (desc->handle_irq == &handle_bad_irq)
391 desc->handle_irq = NULL;
392}
393
David Brownell0c5d1eb2008-10-01 14:46:18 -0700394int __irq_set_trigger(struct irq_desc *desc, unsigned int irq,
Uwe Kleine-König82736f42008-07-23 21:28:54 -0700395 unsigned long flags)
396{
397 int ret;
David Brownell0c5d1eb2008-10-01 14:46:18 -0700398 struct irq_chip *chip = desc->chip;
Uwe Kleine-König82736f42008-07-23 21:28:54 -0700399
400 if (!chip || !chip->set_type) {
401 /*
402 * IRQF_TRIGGER_* but the PIC does not support multiple
403 * flow-types?
404 */
Mark Nelson3ff68a62008-11-13 21:37:41 +1100405 pr_debug("No set_type function for IRQ %d (%s)\n", irq,
Uwe Kleine-König82736f42008-07-23 21:28:54 -0700406 chip ? (chip->name ? : "unknown") : "unknown");
407 return 0;
408 }
409
David Brownellf2b662d2008-12-01 14:31:38 -0800410 /* caller masked out all except trigger mode flags */
411 ret = chip->set_type(irq, flags);
Uwe Kleine-König82736f42008-07-23 21:28:54 -0700412
413 if (ret)
David Brownellc69ad712008-08-05 13:01:14 -0700414 pr_err("setting trigger mode %d for irq %u failed (%pF)\n",
David Brownellf2b662d2008-12-01 14:31:38 -0800415 (int)flags, irq, chip->set_type);
David Brownell0c5d1eb2008-10-01 14:46:18 -0700416 else {
David Brownellf2b662d2008-12-01 14:31:38 -0800417 if (flags & (IRQ_TYPE_LEVEL_LOW | IRQ_TYPE_LEVEL_HIGH))
418 flags |= IRQ_LEVEL;
David Brownell0c5d1eb2008-10-01 14:46:18 -0700419 /* note that IRQF_TRIGGER_MASK == IRQ_TYPE_SENSE_MASK */
David Brownellf2b662d2008-12-01 14:31:38 -0800420 desc->status &= ~(IRQ_LEVEL | IRQ_TYPE_SENSE_MASK);
421 desc->status |= flags;
David Brownell0c5d1eb2008-10-01 14:46:18 -0700422 }
Uwe Kleine-König82736f42008-07-23 21:28:54 -0700423
424 return ret;
425}
426
Thomas Gleixner3aa551c2009-03-23 18:28:15 +0100427static int irq_wait_for_interrupt(struct irqaction *action)
428{
429 while (!kthread_should_stop()) {
430 set_current_state(TASK_INTERRUPTIBLE);
Thomas Gleixnerf48fe812009-03-24 11:46:22 +0100431
432 if (test_and_clear_bit(IRQTF_RUNTHREAD,
433 &action->thread_flags)) {
Thomas Gleixner3aa551c2009-03-23 18:28:15 +0100434 __set_current_state(TASK_RUNNING);
435 return 0;
Thomas Gleixnerf48fe812009-03-24 11:46:22 +0100436 }
437 schedule();
Thomas Gleixner3aa551c2009-03-23 18:28:15 +0100438 }
439 return -1;
440}
441
442/*
443 * Interrupt handler thread
444 */
445static int irq_thread(void *data)
446{
447 struct sched_param param = { .sched_priority = MAX_USER_RT_PRIO/2, };
448 struct irqaction *action = data;
449 struct irq_desc *desc = irq_to_desc(action->irq);
450 int wake;
451
452 sched_setscheduler(current, SCHED_FIFO, &param);
453 current->irqaction = action;
454
455 while (!irq_wait_for_interrupt(action)) {
456
457 atomic_inc(&desc->threads_active);
458
459 spin_lock_irq(&desc->lock);
460 if (unlikely(desc->status & IRQ_DISABLED)) {
461 /*
462 * CHECKME: We might need a dedicated
463 * IRQ_THREAD_PENDING flag here, which
464 * retriggers the thread in check_irq_resend()
465 * but AFAICT IRQ_PENDING should be fine as it
466 * retriggers the interrupt itself --- tglx
467 */
468 desc->status |= IRQ_PENDING;
469 spin_unlock_irq(&desc->lock);
470 } else {
471 spin_unlock_irq(&desc->lock);
472
473 action->thread_fn(action->irq, action->dev_id);
474 }
475
476 wake = atomic_dec_and_test(&desc->threads_active);
477
478 if (wake && waitqueue_active(&desc->wait_for_threads))
479 wake_up(&desc->wait_for_threads);
480 }
481
482 /*
483 * Clear irqaction. Otherwise exit_irq_thread() would make
484 * fuzz about an active irq thread going into nirvana.
485 */
486 current->irqaction = NULL;
487 return 0;
488}
489
490/*
491 * Called from do_exit()
492 */
493void exit_irq_thread(void)
494{
495 struct task_struct *tsk = current;
496
497 if (!tsk->irqaction)
498 return;
499
500 printk(KERN_ERR
501 "exiting task \"%s\" (%d) is an active IRQ thread (irq %d)\n",
502 tsk->comm ? tsk->comm : "", tsk->pid, tsk->irqaction->irq);
503
504 /*
505 * Set the THREAD DIED flag to prevent further wakeups of the
506 * soon to be gone threaded handler.
507 */
508 set_bit(IRQTF_DIED, &tsk->irqaction->flags);
509}
510
Linus Torvalds1da177e2005-04-16 15:20:36 -0700511/*
512 * Internal function to register an irqaction - typically used to
513 * allocate special interrupts that are part of the architecture.
514 */
Thomas Gleixnerd3c60042008-10-16 09:55:00 +0200515static int
Ingo Molnar327ec562009-02-15 11:21:37 +0100516__setup_irq(unsigned int irq, struct irq_desc *desc, struct irqaction *new)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700517{
Ingo Molnarf17c7542009-02-17 20:43:37 +0100518 struct irqaction *old, **old_ptr;
Andrew Morton8b126b72006-11-14 02:03:23 -0800519 const char *old_name = NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700520 unsigned long flags;
521 int shared = 0;
Uwe Kleine-König82736f42008-07-23 21:28:54 -0700522 int ret;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700523
Yinghai Lu7d94f7c2008-08-19 20:50:14 -0700524 if (!desc)
Matthew Wilcoxc2b5a252005-11-03 07:51:18 -0700525 return -EINVAL;
526
Ingo Molnarf1c26622006-06-29 02:24:57 -0700527 if (desc->chip == &no_irq_chip)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700528 return -ENOSYS;
529 /*
530 * Some drivers like serial.c use request_irq() heavily,
531 * so we have to be careful not to interfere with a
532 * running system.
533 */
Thomas Gleixner3cca53b2006-07-01 19:29:31 -0700534 if (new->flags & IRQF_SAMPLE_RANDOM) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700535 /*
536 * This function might sleep, we want to call it first,
537 * outside of the atomic block.
538 * Yes, this might clear the entropy pool if the wrong
539 * driver is attempted to be loaded, without actually
540 * installing a new handler, but is this really a problem,
541 * only the sysadmin is able to do this.
542 */
543 rand_initialize_irq(irq);
544 }
545
546 /*
Thomas Gleixner3aa551c2009-03-23 18:28:15 +0100547 * Threaded handler ?
548 */
549 if (new->thread_fn) {
550 struct task_struct *t;
551
552 t = kthread_create(irq_thread, new, "irq/%d-%s", irq,
553 new->name);
554 if (IS_ERR(t))
555 return PTR_ERR(t);
556 /*
557 * We keep the reference to the task struct even if
558 * the thread dies to avoid that the interrupt code
559 * references an already freed task_struct.
560 */
561 get_task_struct(t);
562 new->thread = t;
563 wake_up_process(t);
564 }
565
566 /*
Linus Torvalds1da177e2005-04-16 15:20:36 -0700567 * The following block of code has to be executed atomically
568 */
Ingo Molnar06fcb0c2006-06-29 02:24:40 -0700569 spin_lock_irqsave(&desc->lock, flags);
Ingo Molnarf17c7542009-02-17 20:43:37 +0100570 old_ptr = &desc->action;
571 old = *old_ptr;
Ingo Molnar06fcb0c2006-06-29 02:24:40 -0700572 if (old) {
Thomas Gleixnere76de9f2006-06-29 02:24:56 -0700573 /*
574 * Can't share interrupts unless both agree to and are
575 * the same type (level, edge, polarity). So both flag
Thomas Gleixner3cca53b2006-07-01 19:29:31 -0700576 * fields must have IRQF_SHARED set and the bits which
Thomas Gleixnere76de9f2006-06-29 02:24:56 -0700577 * set the trigger type must match.
578 */
Thomas Gleixner3cca53b2006-07-01 19:29:31 -0700579 if (!((old->flags & new->flags) & IRQF_SHARED) ||
Andrew Morton8b126b72006-11-14 02:03:23 -0800580 ((old->flags ^ new->flags) & IRQF_TRIGGER_MASK)) {
581 old_name = old->name;
Dimitri Sivanichf5163422006-03-25 03:08:23 -0800582 goto mismatch;
Andrew Morton8b126b72006-11-14 02:03:23 -0800583 }
Dimitri Sivanichf5163422006-03-25 03:08:23 -0800584
Thomas Gleixner284c6682006-07-03 02:20:32 +0200585#if defined(CONFIG_IRQ_PER_CPU)
Dimitri Sivanichf5163422006-03-25 03:08:23 -0800586 /* All handlers must agree on per-cpuness */
Thomas Gleixner3cca53b2006-07-01 19:29:31 -0700587 if ((old->flags & IRQF_PERCPU) !=
588 (new->flags & IRQF_PERCPU))
Dimitri Sivanichf5163422006-03-25 03:08:23 -0800589 goto mismatch;
590#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -0700591
592 /* add new interrupt at end of irq queue */
593 do {
Ingo Molnarf17c7542009-02-17 20:43:37 +0100594 old_ptr = &old->next;
595 old = *old_ptr;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700596 } while (old);
597 shared = 1;
598 }
599
Linus Torvalds1da177e2005-04-16 15:20:36 -0700600 if (!shared) {
Thomas Gleixner6a6de9e2006-06-29 02:24:51 -0700601 irq_chip_set_defaults(desc->chip);
Thomas Gleixnere76de9f2006-06-29 02:24:56 -0700602
Thomas Gleixner3aa551c2009-03-23 18:28:15 +0100603 init_waitqueue_head(&desc->wait_for_threads);
604
Uwe Kleine-König82736f42008-07-23 21:28:54 -0700605 /* Setup the type (level, edge polarity) if configured: */
606 if (new->flags & IRQF_TRIGGER_MASK) {
David Brownellf2b662d2008-12-01 14:31:38 -0800607 ret = __irq_set_trigger(desc, irq,
608 new->flags & IRQF_TRIGGER_MASK);
Uwe Kleine-König82736f42008-07-23 21:28:54 -0700609
Thomas Gleixner3aa551c2009-03-23 18:28:15 +0100610 if (ret)
611 goto out_thread;
Uwe Kleine-König82736f42008-07-23 21:28:54 -0700612 } else
613 compat_irq_chip_set_default_handler(desc);
Ahmed S. Darwishf75d2222007-05-08 00:27:55 -0700614#if defined(CONFIG_IRQ_PER_CPU)
615 if (new->flags & IRQF_PERCPU)
616 desc->status |= IRQ_PER_CPU;
617#endif
618
Thomas Gleixner94d39e12006-06-29 02:24:50 -0700619 desc->status &= ~(IRQ_AUTODETECT | IRQ_WAITING |
Thomas Gleixner1adb0852008-04-28 17:01:56 +0200620 IRQ_INPROGRESS | IRQ_SPURIOUS_DISABLED);
Thomas Gleixner94d39e12006-06-29 02:24:50 -0700621
622 if (!(desc->status & IRQ_NOAUTOEN)) {
623 desc->depth = 0;
624 desc->status &= ~IRQ_DISABLED;
Pawel MOLL7e6e1782008-09-01 10:12:11 +0100625 desc->chip->startup(irq);
Thomas Gleixnere76de9f2006-06-29 02:24:56 -0700626 } else
627 /* Undo nested disables: */
628 desc->depth = 1;
Max Krasnyansky18404752008-05-29 11:02:52 -0700629
Thomas Gleixner612e3682008-11-07 13:58:46 +0100630 /* Exclude IRQ from balancing if requested */
631 if (new->flags & IRQF_NOBALANCING)
632 desc->status |= IRQ_NO_BALANCING;
633
Max Krasnyansky18404752008-05-29 11:02:52 -0700634 /* Set default affinity mask once everything is setup */
Hannes Eder548c8932009-02-08 20:24:47 +0100635 setup_affinity(irq, desc);
David Brownell0c5d1eb2008-10-01 14:46:18 -0700636
637 } else if ((new->flags & IRQF_TRIGGER_MASK)
638 && (new->flags & IRQF_TRIGGER_MASK)
639 != (desc->status & IRQ_TYPE_SENSE_MASK)) {
640 /* hope the handler works with the actual trigger mode... */
641 pr_warning("IRQ %d uses trigger mode %d; requested %d\n",
642 irq, (int)(desc->status & IRQ_TYPE_SENSE_MASK),
643 (int)(new->flags & IRQF_TRIGGER_MASK));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700644 }
Uwe Kleine-König82736f42008-07-23 21:28:54 -0700645
Ingo Molnarf17c7542009-02-17 20:43:37 +0100646 *old_ptr = new;
Uwe Kleine-König82736f42008-07-23 21:28:54 -0700647
Linus Torvalds8528b0f2007-01-23 14:16:31 -0800648 /* Reset broken irq detection when installing new handler */
649 desc->irq_count = 0;
650 desc->irqs_unhandled = 0;
Thomas Gleixner1adb0852008-04-28 17:01:56 +0200651
652 /*
653 * Check whether we disabled the irq via the spurious handler
654 * before. Reenable it and give it another chance.
655 */
656 if (shared && (desc->status & IRQ_SPURIOUS_DISABLED)) {
657 desc->status &= ~IRQ_SPURIOUS_DISABLED;
Rafael J. Wysocki0a0c5162009-03-16 22:33:49 +0100658 __enable_irq(desc, irq, false);
Thomas Gleixner1adb0852008-04-28 17:01:56 +0200659 }
660
Ingo Molnar06fcb0c2006-06-29 02:24:40 -0700661 spin_unlock_irqrestore(&desc->lock, flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700662
663 new->irq = irq;
Yinghai Lu2c6927a2008-08-19 20:50:11 -0700664 register_irq_proc(irq, desc);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700665 new->dir = NULL;
666 register_handler_proc(irq, new);
667
668 return 0;
Dimitri Sivanichf5163422006-03-25 03:08:23 -0800669
670mismatch:
Alan Cox3f050442007-02-12 00:52:04 -0800671#ifdef CONFIG_DEBUG_SHIRQ
Thomas Gleixner3cca53b2006-07-01 19:29:31 -0700672 if (!(new->flags & IRQF_PROBE_SHARED)) {
Bjorn Helgaase8c4b9d2006-07-01 04:35:45 -0700673 printk(KERN_ERR "IRQ handler type mismatch for IRQ %d\n", irq);
Andrew Morton8b126b72006-11-14 02:03:23 -0800674 if (old_name)
675 printk(KERN_ERR "current handler: %s\n", old_name);
Andrew Morton13e87ec2006-04-27 18:39:18 -0700676 dump_stack();
677 }
Alan Cox3f050442007-02-12 00:52:04 -0800678#endif
Thomas Gleixner3aa551c2009-03-23 18:28:15 +0100679 ret = -EBUSY;
680
681out_thread:
Andrew Morton8b126b72006-11-14 02:03:23 -0800682 spin_unlock_irqrestore(&desc->lock, flags);
Thomas Gleixner3aa551c2009-03-23 18:28:15 +0100683 if (new->thread) {
684 struct task_struct *t = new->thread;
685
686 new->thread = NULL;
687 if (likely(!test_bit(IRQTF_DIED, &new->thread_flags)))
688 kthread_stop(t);
689 put_task_struct(t);
690 }
691 return ret;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700692}
693
694/**
Thomas Gleixnerd3c60042008-10-16 09:55:00 +0200695 * setup_irq - setup an interrupt
696 * @irq: Interrupt line to setup
697 * @act: irqaction for the interrupt
698 *
699 * Used to statically setup interrupts in the early boot process.
700 */
701int setup_irq(unsigned int irq, struct irqaction *act)
702{
703 struct irq_desc *desc = irq_to_desc(irq);
704
705 return __setup_irq(irq, desc, act);
706}
Magnus Dammeb53b4e2009-03-12 21:05:59 +0900707EXPORT_SYMBOL_GPL(setup_irq);
Thomas Gleixnerd3c60042008-10-16 09:55:00 +0200708
Magnus Dammcbf94f02009-03-12 21:05:51 +0900709 /*
710 * Internal function to unregister an irqaction - used to free
711 * regular and special interrupts that are part of the architecture.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700712 */
Magnus Dammcbf94f02009-03-12 21:05:51 +0900713static struct irqaction *__free_irq(unsigned int irq, void *dev_id)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700714{
Thomas Gleixnerd3c60042008-10-16 09:55:00 +0200715 struct irq_desc *desc = irq_to_desc(irq);
Ingo Molnarf17c7542009-02-17 20:43:37 +0100716 struct irqaction *action, **action_ptr;
Thomas Gleixner3aa551c2009-03-23 18:28:15 +0100717 struct task_struct *irqthread;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700718 unsigned long flags;
719
Ingo Molnarae88a232009-02-15 11:29:50 +0100720 WARN(in_interrupt(), "Trying to free IRQ %d from IRQ context!\n", irq);
Yinghai Lu7d94f7c2008-08-19 20:50:14 -0700721
Yinghai Lu7d94f7c2008-08-19 20:50:14 -0700722 if (!desc)
Magnus Dammf21cfb22009-03-12 21:05:42 +0900723 return NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700724
Ingo Molnar06fcb0c2006-06-29 02:24:40 -0700725 spin_lock_irqsave(&desc->lock, flags);
Ingo Molnarae88a232009-02-15 11:29:50 +0100726
727 /*
728 * There can be multiple actions per IRQ descriptor, find the right
729 * one based on the dev_id:
730 */
Ingo Molnarf17c7542009-02-17 20:43:37 +0100731 action_ptr = &desc->action;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700732 for (;;) {
Ingo Molnarf17c7542009-02-17 20:43:37 +0100733 action = *action_ptr;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700734
Ingo Molnarae88a232009-02-15 11:29:50 +0100735 if (!action) {
736 WARN(1, "Trying to free already-free IRQ %d\n", irq);
Ingo Molnar06fcb0c2006-06-29 02:24:40 -0700737 spin_unlock_irqrestore(&desc->lock, flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700738
Magnus Dammf21cfb22009-03-12 21:05:42 +0900739 return NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700740 }
Ingo Molnarae88a232009-02-15 11:29:50 +0100741
Ingo Molnar8316e382009-02-17 20:28:29 +0100742 if (action->dev_id == dev_id)
743 break;
Ingo Molnarf17c7542009-02-17 20:43:37 +0100744 action_ptr = &action->next;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700745 }
Ingo Molnarae88a232009-02-15 11:29:50 +0100746
747 /* Found it - now remove it from the list of entries: */
Ingo Molnarf17c7542009-02-17 20:43:37 +0100748 *action_ptr = action->next;
Ingo Molnarae88a232009-02-15 11:29:50 +0100749
750 /* Currently used only by UML, might disappear one day: */
751#ifdef CONFIG_IRQ_RELEASE_METHOD
752 if (desc->chip->release)
753 desc->chip->release(irq, dev_id);
754#endif
755
756 /* If this was the last handler, shut down the IRQ line: */
757 if (!desc->action) {
758 desc->status |= IRQ_DISABLED;
759 if (desc->chip->shutdown)
760 desc->chip->shutdown(irq);
761 else
762 desc->chip->disable(irq);
763 }
Thomas Gleixner3aa551c2009-03-23 18:28:15 +0100764
765 irqthread = action->thread;
766 action->thread = NULL;
767
Ingo Molnarae88a232009-02-15 11:29:50 +0100768 spin_unlock_irqrestore(&desc->lock, flags);
769
770 unregister_handler_proc(irq, action);
771
772 /* Make sure it's not being used on another CPU: */
773 synchronize_irq(irq);
774
Thomas Gleixner3aa551c2009-03-23 18:28:15 +0100775 if (irqthread) {
776 if (!test_bit(IRQTF_DIED, &action->thread_flags))
777 kthread_stop(irqthread);
778 put_task_struct(irqthread);
779 }
780
Ingo Molnarae88a232009-02-15 11:29:50 +0100781#ifdef CONFIG_DEBUG_SHIRQ
782 /*
783 * It's a shared IRQ -- the driver ought to be prepared for an IRQ
784 * event to happen even now it's being freed, so let's make sure that
785 * is so by doing an extra call to the handler ....
786 *
787 * ( We do this after actually deregistering it, to make sure that a
788 * 'real' IRQ doesn't run in * parallel with our fake. )
789 */
790 if (action->flags & IRQF_SHARED) {
791 local_irq_save(flags);
792 action->handler(irq, dev_id);
793 local_irq_restore(flags);
794 }
795#endif
Magnus Dammf21cfb22009-03-12 21:05:42 +0900796 return action;
797}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700798
799/**
Magnus Dammcbf94f02009-03-12 21:05:51 +0900800 * remove_irq - free an interrupt
801 * @irq: Interrupt line to free
802 * @act: irqaction for the interrupt
803 *
804 * Used to remove interrupts statically setup by the early boot process.
805 */
806void remove_irq(unsigned int irq, struct irqaction *act)
807{
808 __free_irq(irq, act->dev_id);
809}
Magnus Dammeb53b4e2009-03-12 21:05:59 +0900810EXPORT_SYMBOL_GPL(remove_irq);
Magnus Dammcbf94f02009-03-12 21:05:51 +0900811
812/**
Magnus Dammf21cfb22009-03-12 21:05:42 +0900813 * free_irq - free an interrupt allocated with request_irq
Linus Torvalds1da177e2005-04-16 15:20:36 -0700814 * @irq: Interrupt line to free
815 * @dev_id: Device identity to free
816 *
817 * Remove an interrupt handler. The handler is removed and if the
818 * interrupt line is no longer in use by any driver it is disabled.
819 * On a shared IRQ the caller must ensure the interrupt is disabled
820 * on the card it drives before calling this function. The function
821 * does not return until any executing interrupts for this IRQ
822 * have completed.
823 *
824 * This function must not be called from interrupt context.
825 */
826void free_irq(unsigned int irq, void *dev_id)
827{
Magnus Dammcbf94f02009-03-12 21:05:51 +0900828 kfree(__free_irq(irq, dev_id));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700829}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700830EXPORT_SYMBOL(free_irq);
831
832/**
Thomas Gleixner3aa551c2009-03-23 18:28:15 +0100833 * request_threaded_irq - allocate an interrupt line
Linus Torvalds1da177e2005-04-16 15:20:36 -0700834 * @irq: Interrupt line to allocate
Thomas Gleixner3aa551c2009-03-23 18:28:15 +0100835 * @handler: Function to be called when the IRQ occurs.
836 * Primary handler for threaded interrupts
Thomas Gleixnerf48fe812009-03-24 11:46:22 +0100837 * @thread_fn: Function called from the irq handler thread
838 * If NULL, no irq thread is created
Linus Torvalds1da177e2005-04-16 15:20:36 -0700839 * @irqflags: Interrupt type flags
840 * @devname: An ascii name for the claiming device
841 * @dev_id: A cookie passed back to the handler function
842 *
843 * This call allocates interrupt resources and enables the
844 * interrupt line and IRQ handling. From the point this
845 * call is made your handler function may be invoked. Since
846 * your handler function must clear any interrupt the board
847 * raises, you must take care both to initialise your hardware
848 * and to set up the interrupt handler in the right order.
849 *
Thomas Gleixner3aa551c2009-03-23 18:28:15 +0100850 * If you want to set up a threaded irq handler for your device
851 * then you need to supply @handler and @thread_fn. @handler ist
852 * still called in hard interrupt context and has to check
853 * whether the interrupt originates from the device. If yes it
854 * needs to disable the interrupt on the device and return
855 * IRQ_THREAD_WAKE which will wake up the handler thread and run
856 * @thread_fn. This split handler design is necessary to support
857 * shared interrupts.
858 *
Linus Torvalds1da177e2005-04-16 15:20:36 -0700859 * Dev_id must be globally unique. Normally the address of the
860 * device data structure is used as the cookie. Since the handler
861 * receives this value it makes sense to use it.
862 *
863 * If your interrupt is shared you must pass a non NULL dev_id
864 * as this is required when freeing the interrupt.
865 *
866 * Flags:
867 *
Thomas Gleixner3cca53b2006-07-01 19:29:31 -0700868 * IRQF_SHARED Interrupt is shared
869 * IRQF_DISABLED Disable local interrupts while processing
870 * IRQF_SAMPLE_RANDOM The interrupt can be used for entropy
David Brownell0c5d1eb2008-10-01 14:46:18 -0700871 * IRQF_TRIGGER_* Specify active edge(s) or level
Linus Torvalds1da177e2005-04-16 15:20:36 -0700872 *
873 */
Thomas Gleixner3aa551c2009-03-23 18:28:15 +0100874int request_threaded_irq(unsigned int irq, irq_handler_t handler,
875 irq_handler_t thread_fn, unsigned long irqflags,
876 const char *devname, void *dev_id)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700877{
Ingo Molnar06fcb0c2006-06-29 02:24:40 -0700878 struct irqaction *action;
Yinghai Lu08678b02008-08-19 20:50:05 -0700879 struct irq_desc *desc;
Thomas Gleixnerd3c60042008-10-16 09:55:00 +0200880 int retval;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700881
David Brownell470c6622008-12-01 14:31:37 -0800882 /*
883 * handle_IRQ_event() always ignores IRQF_DISABLED except for
884 * the _first_ irqaction (sigh). That can cause oopsing, but
885 * the behavior is classified as "will not fix" so we need to
886 * start nudging drivers away from using that idiom.
887 */
Ingo Molnar327ec562009-02-15 11:21:37 +0100888 if ((irqflags & (IRQF_SHARED|IRQF_DISABLED)) ==
889 (IRQF_SHARED|IRQF_DISABLED)) {
890 pr_warning(
891 "IRQ %d/%s: IRQF_DISABLED is not guaranteed on shared IRQs\n",
892 irq, devname);
893 }
David Brownell470c6622008-12-01 14:31:37 -0800894
Ingo Molnarfbb9ce952006-07-03 00:24:50 -0700895#ifdef CONFIG_LOCKDEP
896 /*
897 * Lockdep wants atomic interrupt handlers:
898 */
Thomas Gleixner38515e92007-02-14 00:33:16 -0800899 irqflags |= IRQF_DISABLED;
Ingo Molnarfbb9ce952006-07-03 00:24:50 -0700900#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -0700901 /*
902 * Sanity-check: shared interrupts must pass in a real dev-ID,
903 * otherwise we'll have trouble later trying to figure out
904 * which interrupt is which (messes up the interrupt freeing
905 * logic etc).
906 */
Thomas Gleixner3cca53b2006-07-01 19:29:31 -0700907 if ((irqflags & IRQF_SHARED) && !dev_id)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700908 return -EINVAL;
Yinghai Lu7d94f7c2008-08-19 20:50:14 -0700909
Yinghai Lucb5bc832008-08-19 20:50:17 -0700910 desc = irq_to_desc(irq);
Yinghai Lu7d94f7c2008-08-19 20:50:14 -0700911 if (!desc)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700912 return -EINVAL;
Yinghai Lu7d94f7c2008-08-19 20:50:14 -0700913
Yinghai Lu08678b02008-08-19 20:50:05 -0700914 if (desc->status & IRQ_NOREQUEST)
Thomas Gleixner6550c772006-06-29 02:24:49 -0700915 return -EINVAL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700916 if (!handler)
917 return -EINVAL;
918
Thomas Gleixner45535732009-02-22 23:00:32 +0100919 action = kzalloc(sizeof(struct irqaction), GFP_KERNEL);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700920 if (!action)
921 return -ENOMEM;
922
923 action->handler = handler;
Thomas Gleixner3aa551c2009-03-23 18:28:15 +0100924 action->thread_fn = thread_fn;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700925 action->flags = irqflags;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700926 action->name = devname;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700927 action->dev_id = dev_id;
928
Thomas Gleixnerd3c60042008-10-16 09:55:00 +0200929 retval = __setup_irq(irq, desc, action);
Anton Vorontsov377bf1e2008-08-21 22:58:28 +0400930 if (retval)
931 kfree(action);
932
David Woodhousea304e1b2007-02-12 00:52:00 -0800933#ifdef CONFIG_DEBUG_SHIRQ
934 if (irqflags & IRQF_SHARED) {
935 /*
936 * It's a shared IRQ -- the driver ought to be prepared for it
937 * to happen immediately, so let's make sure....
Anton Vorontsov377bf1e2008-08-21 22:58:28 +0400938 * We disable the irq to make sure that a 'real' IRQ doesn't
939 * run in parallel with our fake.
David Woodhousea304e1b2007-02-12 00:52:00 -0800940 */
Jarek Poplawski59845b12007-08-30 23:56:34 -0700941 unsigned long flags;
David Woodhousea304e1b2007-02-12 00:52:00 -0800942
Anton Vorontsov377bf1e2008-08-21 22:58:28 +0400943 disable_irq(irq);
Jarek Poplawski59845b12007-08-30 23:56:34 -0700944 local_irq_save(flags);
Anton Vorontsov377bf1e2008-08-21 22:58:28 +0400945
Jarek Poplawski59845b12007-08-30 23:56:34 -0700946 handler(irq, dev_id);
Anton Vorontsov377bf1e2008-08-21 22:58:28 +0400947
Jarek Poplawski59845b12007-08-30 23:56:34 -0700948 local_irq_restore(flags);
Anton Vorontsov377bf1e2008-08-21 22:58:28 +0400949 enable_irq(irq);
David Woodhousea304e1b2007-02-12 00:52:00 -0800950 }
951#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -0700952 return retval;
953}
Thomas Gleixner3aa551c2009-03-23 18:28:15 +0100954EXPORT_SYMBOL(request_threaded_irq);