Commit | Line | Data |
---|---|---|
1da177e4 LT |
1 | /* |
2 | * linux/kernel/irq/manage.c | |
3 | * | |
a34db9b2 IM |
4 | * Copyright (C) 1992, 1998-2006 Linus Torvalds, Ingo Molnar |
5 | * Copyright (C) 2005-2006 Thomas Gleixner | |
1da177e4 LT |
6 | * |
7 | * This file contains driver APIs to the irq subsystem. | |
8 | */ | |
9 | ||
10 | #include <linux/irq.h> | |
11 | #include <linux/module.h> | |
12 | #include <linux/random.h> | |
13 | #include <linux/interrupt.h> | |
1aeb272c | 14 | #include <linux/slab.h> |
1da177e4 LT |
15 | |
16 | #include "internals.h" | |
17 | ||
18 | #ifdef CONFIG_SMP | |
19 | ||
1da177e4 LT |
20 | /** |
21 | * synchronize_irq - wait for pending IRQ handlers (on other CPUs) | |
1e5d5331 | 22 | * @irq: interrupt number to wait for |
1da177e4 LT |
23 | * |
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 | */ | |
30 | void synchronize_irq(unsigned int irq) | |
31 | { | |
32 | struct irq_desc *desc = irq_desc + irq; | |
a98ce5c6 | 33 | unsigned int status; |
1da177e4 | 34 | |
c2b5a251 MW |
35 | if (irq >= NR_IRQS) |
36 | return; | |
37 | ||
a98ce5c6 HX |
38 | 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); | |
1da177e4 | 55 | } |
1da177e4 LT |
56 | EXPORT_SYMBOL(synchronize_irq); |
57 | ||
771ee3b0 TG |
58 | /** |
59 | * irq_can_set_affinity - Check if the affinity of a given irq can be set | |
60 | * @irq: Interrupt to check | |
61 | * | |
62 | */ | |
63 | int irq_can_set_affinity(unsigned int irq) | |
64 | { | |
65 | struct irq_desc *desc = irq_desc + irq; | |
66 | ||
67 | if (CHECK_IRQ_PER_CPU(desc->status) || !desc->chip || | |
68 | !desc->chip->set_affinity) | |
69 | return 0; | |
70 | ||
71 | return 1; | |
72 | } | |
73 | ||
74 | /** | |
75 | * irq_set_affinity - Set the irq affinity of a given irq | |
76 | * @irq: Interrupt to set affinity | |
77 | * @cpumask: cpumask | |
78 | * | |
79 | */ | |
80 | int irq_set_affinity(unsigned int irq, cpumask_t cpumask) | |
81 | { | |
82 | struct irq_desc *desc = irq_desc + irq; | |
83 | ||
84 | if (!desc->chip->set_affinity) | |
85 | return -EINVAL; | |
86 | ||
87 | set_balance_irq_affinity(irq, cpumask); | |
88 | ||
89 | #ifdef CONFIG_GENERIC_PENDING_IRQ | |
90 | set_pending_irq(irq, cpumask); | |
91 | #else | |
92 | desc->affinity = cpumask; | |
93 | desc->chip->set_affinity(irq, cpumask); | |
94 | #endif | |
95 | return 0; | |
96 | } | |
97 | ||
1da177e4 LT |
98 | #endif |
99 | ||
100 | /** | |
101 | * disable_irq_nosync - disable an irq without waiting | |
102 | * @irq: Interrupt to disable | |
103 | * | |
104 | * Disable the selected interrupt line. Disables and Enables are | |
105 | * nested. | |
106 | * Unlike disable_irq(), this function does not ensure existing | |
107 | * instances of the IRQ handler have completed before returning. | |
108 | * | |
109 | * This function may be called from IRQ context. | |
110 | */ | |
111 | void disable_irq_nosync(unsigned int irq) | |
112 | { | |
34ffdb72 | 113 | struct irq_desc *desc = irq_desc + irq; |
1da177e4 LT |
114 | unsigned long flags; |
115 | ||
c2b5a251 MW |
116 | if (irq >= NR_IRQS) |
117 | return; | |
118 | ||
1da177e4 LT |
119 | spin_lock_irqsave(&desc->lock, flags); |
120 | if (!desc->depth++) { | |
121 | desc->status |= IRQ_DISABLED; | |
d1bef4ed | 122 | desc->chip->disable(irq); |
1da177e4 LT |
123 | } |
124 | spin_unlock_irqrestore(&desc->lock, flags); | |
125 | } | |
1da177e4 LT |
126 | EXPORT_SYMBOL(disable_irq_nosync); |
127 | ||
128 | /** | |
129 | * disable_irq - disable an irq and wait for completion | |
130 | * @irq: Interrupt to disable | |
131 | * | |
132 | * Disable the selected interrupt line. Enables and Disables are | |
133 | * nested. | |
134 | * This function waits for any pending IRQ handlers for this interrupt | |
135 | * to complete before returning. If you use this function while | |
136 | * holding a resource the IRQ handler may need you will deadlock. | |
137 | * | |
138 | * This function may be called - with care - from IRQ context. | |
139 | */ | |
140 | void disable_irq(unsigned int irq) | |
141 | { | |
34ffdb72 | 142 | struct irq_desc *desc = irq_desc + irq; |
1da177e4 | 143 | |
c2b5a251 MW |
144 | if (irq >= NR_IRQS) |
145 | return; | |
146 | ||
1da177e4 LT |
147 | disable_irq_nosync(irq); |
148 | if (desc->action) | |
149 | synchronize_irq(irq); | |
150 | } | |
1da177e4 LT |
151 | EXPORT_SYMBOL(disable_irq); |
152 | ||
153 | /** | |
154 | * enable_irq - enable handling of an irq | |
155 | * @irq: Interrupt to enable | |
156 | * | |
157 | * Undoes the effect of one call to disable_irq(). If this | |
158 | * matches the last disable, processing of interrupts on this | |
159 | * IRQ line is re-enabled. | |
160 | * | |
161 | * This function may be called from IRQ context. | |
162 | */ | |
163 | void enable_irq(unsigned int irq) | |
164 | { | |
34ffdb72 | 165 | struct irq_desc *desc = irq_desc + irq; |
1da177e4 LT |
166 | unsigned long flags; |
167 | ||
c2b5a251 MW |
168 | if (irq >= NR_IRQS) |
169 | return; | |
170 | ||
1da177e4 LT |
171 | spin_lock_irqsave(&desc->lock, flags); |
172 | switch (desc->depth) { | |
173 | case 0: | |
e8c4b9d0 | 174 | printk(KERN_WARNING "Unbalanced enable for IRQ %d\n", irq); |
1da177e4 LT |
175 | WARN_ON(1); |
176 | break; | |
177 | case 1: { | |
3418d724 TG |
178 | unsigned int status = desc->status & ~IRQ_DISABLED; |
179 | ||
180 | /* Prevent probing on this irq: */ | |
181 | desc->status = status | IRQ_NOPROBE; | |
a4633adc | 182 | check_irq_resend(desc, irq); |
1da177e4 LT |
183 | /* fall-through */ |
184 | } | |
185 | default: | |
186 | desc->depth--; | |
187 | } | |
188 | spin_unlock_irqrestore(&desc->lock, flags); | |
189 | } | |
1da177e4 LT |
190 | EXPORT_SYMBOL(enable_irq); |
191 | ||
ba9a2331 TG |
192 | /** |
193 | * set_irq_wake - control irq power management wakeup | |
194 | * @irq: interrupt to control | |
195 | * @on: enable/disable power management wakeup | |
196 | * | |
15a647eb DB |
197 | * Enable/disable power management wakeup mode, which is |
198 | * disabled by default. Enables and disables must match, | |
199 | * just as they match for non-wakeup mode support. | |
200 | * | |
201 | * Wakeup mode lets this IRQ wake the system from sleep | |
202 | * states like "suspend to RAM". | |
ba9a2331 TG |
203 | */ |
204 | int set_irq_wake(unsigned int irq, unsigned int on) | |
205 | { | |
206 | struct irq_desc *desc = irq_desc + irq; | |
207 | unsigned long flags; | |
208 | int ret = -ENXIO; | |
15a647eb | 209 | int (*set_wake)(unsigned, unsigned) = desc->chip->set_wake; |
ba9a2331 | 210 | |
15a647eb DB |
211 | /* wakeup-capable irqs can be shared between drivers that |
212 | * don't need to have the same sleep mode behaviors. | |
213 | */ | |
ba9a2331 | 214 | spin_lock_irqsave(&desc->lock, flags); |
15a647eb DB |
215 | if (on) { |
216 | if (desc->wake_depth++ == 0) | |
217 | desc->status |= IRQ_WAKEUP; | |
218 | else | |
219 | set_wake = NULL; | |
220 | } else { | |
221 | if (desc->wake_depth == 0) { | |
222 | printk(KERN_WARNING "Unbalanced IRQ %d " | |
223 | "wake disable\n", irq); | |
224 | WARN_ON(1); | |
225 | } else if (--desc->wake_depth == 0) | |
226 | desc->status &= ~IRQ_WAKEUP; | |
227 | else | |
228 | set_wake = NULL; | |
229 | } | |
230 | if (set_wake) | |
ba9a2331 TG |
231 | ret = desc->chip->set_wake(irq, on); |
232 | spin_unlock_irqrestore(&desc->lock, flags); | |
233 | return ret; | |
234 | } | |
235 | EXPORT_SYMBOL(set_irq_wake); | |
236 | ||
1da177e4 LT |
237 | /* |
238 | * Internal function that tells the architecture code whether a | |
239 | * particular irq has been exclusively allocated or is available | |
240 | * for driver use. | |
241 | */ | |
242 | int can_request_irq(unsigned int irq, unsigned long irqflags) | |
243 | { | |
244 | struct irqaction *action; | |
245 | ||
6550c775 | 246 | if (irq >= NR_IRQS || irq_desc[irq].status & IRQ_NOREQUEST) |
1da177e4 LT |
247 | return 0; |
248 | ||
249 | action = irq_desc[irq].action; | |
250 | if (action) | |
3cca53b0 | 251 | if (irqflags & action->flags & IRQF_SHARED) |
1da177e4 LT |
252 | action = NULL; |
253 | ||
254 | return !action; | |
255 | } | |
256 | ||
6a6de9ef TG |
257 | void compat_irq_chip_set_default_handler(struct irq_desc *desc) |
258 | { | |
259 | /* | |
260 | * If the architecture still has not overriden | |
261 | * the flow handler then zap the default. This | |
262 | * should catch incorrect flow-type setting. | |
263 | */ | |
264 | if (desc->handle_irq == &handle_bad_irq) | |
265 | desc->handle_irq = NULL; | |
266 | } | |
267 | ||
1da177e4 LT |
268 | /* |
269 | * Internal function to register an irqaction - typically used to | |
270 | * allocate special interrupts that are part of the architecture. | |
271 | */ | |
06fcb0c6 | 272 | int setup_irq(unsigned int irq, struct irqaction *new) |
1da177e4 LT |
273 | { |
274 | struct irq_desc *desc = irq_desc + irq; | |
275 | struct irqaction *old, **p; | |
8b126b77 | 276 | const char *old_name = NULL; |
1da177e4 LT |
277 | unsigned long flags; |
278 | int shared = 0; | |
279 | ||
c2b5a251 MW |
280 | if (irq >= NR_IRQS) |
281 | return -EINVAL; | |
282 | ||
f1c2662c | 283 | if (desc->chip == &no_irq_chip) |
1da177e4 LT |
284 | return -ENOSYS; |
285 | /* | |
286 | * Some drivers like serial.c use request_irq() heavily, | |
287 | * so we have to be careful not to interfere with a | |
288 | * running system. | |
289 | */ | |
3cca53b0 | 290 | if (new->flags & IRQF_SAMPLE_RANDOM) { |
1da177e4 LT |
291 | /* |
292 | * This function might sleep, we want to call it first, | |
293 | * outside of the atomic block. | |
294 | * Yes, this might clear the entropy pool if the wrong | |
295 | * driver is attempted to be loaded, without actually | |
296 | * installing a new handler, but is this really a problem, | |
297 | * only the sysadmin is able to do this. | |
298 | */ | |
299 | rand_initialize_irq(irq); | |
300 | } | |
301 | ||
302 | /* | |
303 | * The following block of code has to be executed atomically | |
304 | */ | |
06fcb0c6 | 305 | spin_lock_irqsave(&desc->lock, flags); |
1da177e4 | 306 | p = &desc->action; |
06fcb0c6 IM |
307 | old = *p; |
308 | if (old) { | |
e76de9f8 TG |
309 | /* |
310 | * Can't share interrupts unless both agree to and are | |
311 | * the same type (level, edge, polarity). So both flag | |
3cca53b0 | 312 | * fields must have IRQF_SHARED set and the bits which |
e76de9f8 TG |
313 | * set the trigger type must match. |
314 | */ | |
3cca53b0 | 315 | if (!((old->flags & new->flags) & IRQF_SHARED) || |
8b126b77 AM |
316 | ((old->flags ^ new->flags) & IRQF_TRIGGER_MASK)) { |
317 | old_name = old->name; | |
f5163427 | 318 | goto mismatch; |
8b126b77 | 319 | } |
f5163427 | 320 | |
284c6680 | 321 | #if defined(CONFIG_IRQ_PER_CPU) |
f5163427 | 322 | /* All handlers must agree on per-cpuness */ |
3cca53b0 TG |
323 | if ((old->flags & IRQF_PERCPU) != |
324 | (new->flags & IRQF_PERCPU)) | |
f5163427 DS |
325 | goto mismatch; |
326 | #endif | |
1da177e4 LT |
327 | |
328 | /* add new interrupt at end of irq queue */ | |
329 | do { | |
330 | p = &old->next; | |
331 | old = *p; | |
332 | } while (old); | |
333 | shared = 1; | |
334 | } | |
335 | ||
336 | *p = new; | |
f75d222b | 337 | |
950f4427 TG |
338 | /* Exclude IRQ from balancing */ |
339 | if (new->flags & IRQF_NOBALANCING) | |
340 | desc->status |= IRQ_NO_BALANCING; | |
341 | ||
1da177e4 | 342 | if (!shared) { |
6a6de9ef | 343 | irq_chip_set_defaults(desc->chip); |
e76de9f8 | 344 | |
f75d222b AD |
345 | #if defined(CONFIG_IRQ_PER_CPU) |
346 | if (new->flags & IRQF_PERCPU) | |
347 | desc->status |= IRQ_PER_CPU; | |
348 | #endif | |
349 | ||
e76de9f8 | 350 | /* Setup the type (level, edge polarity) if configured: */ |
3cca53b0 | 351 | if (new->flags & IRQF_TRIGGER_MASK) { |
e76de9f8 TG |
352 | if (desc->chip && desc->chip->set_type) |
353 | desc->chip->set_type(irq, | |
3cca53b0 | 354 | new->flags & IRQF_TRIGGER_MASK); |
e76de9f8 TG |
355 | else |
356 | /* | |
3cca53b0 | 357 | * IRQF_TRIGGER_* but the PIC does not support |
e76de9f8 TG |
358 | * multiple flow-types? |
359 | */ | |
3cca53b0 | 360 | printk(KERN_WARNING "No IRQF_TRIGGER set_type " |
e8c4b9d0 BH |
361 | "function for IRQ %d (%s)\n", irq, |
362 | desc->chip ? desc->chip->name : | |
363 | "unknown"); | |
e76de9f8 TG |
364 | } else |
365 | compat_irq_chip_set_default_handler(desc); | |
6a6de9ef | 366 | |
94d39e1f TG |
367 | desc->status &= ~(IRQ_AUTODETECT | IRQ_WAITING | |
368 | IRQ_INPROGRESS); | |
369 | ||
370 | if (!(desc->status & IRQ_NOAUTOEN)) { | |
371 | desc->depth = 0; | |
372 | desc->status &= ~IRQ_DISABLED; | |
373 | if (desc->chip->startup) | |
374 | desc->chip->startup(irq); | |
375 | else | |
376 | desc->chip->enable(irq); | |
e76de9f8 TG |
377 | } else |
378 | /* Undo nested disables: */ | |
379 | desc->depth = 1; | |
1da177e4 | 380 | } |
8528b0f1 LT |
381 | /* Reset broken irq detection when installing new handler */ |
382 | desc->irq_count = 0; | |
383 | desc->irqs_unhandled = 0; | |
06fcb0c6 | 384 | spin_unlock_irqrestore(&desc->lock, flags); |
1da177e4 LT |
385 | |
386 | new->irq = irq; | |
387 | register_irq_proc(irq); | |
388 | new->dir = NULL; | |
389 | register_handler_proc(irq, new); | |
390 | ||
391 | return 0; | |
f5163427 DS |
392 | |
393 | mismatch: | |
3f050447 | 394 | #ifdef CONFIG_DEBUG_SHIRQ |
3cca53b0 | 395 | if (!(new->flags & IRQF_PROBE_SHARED)) { |
e8c4b9d0 | 396 | printk(KERN_ERR "IRQ handler type mismatch for IRQ %d\n", irq); |
8b126b77 AM |
397 | if (old_name) |
398 | printk(KERN_ERR "current handler: %s\n", old_name); | |
13e87ec6 AM |
399 | dump_stack(); |
400 | } | |
3f050447 | 401 | #endif |
8b126b77 | 402 | spin_unlock_irqrestore(&desc->lock, flags); |
f5163427 | 403 | return -EBUSY; |
1da177e4 LT |
404 | } |
405 | ||
406 | /** | |
407 | * free_irq - free an interrupt | |
408 | * @irq: Interrupt line to free | |
409 | * @dev_id: Device identity to free | |
410 | * | |
411 | * Remove an interrupt handler. The handler is removed and if the | |
412 | * interrupt line is no longer in use by any driver it is disabled. | |
413 | * On a shared IRQ the caller must ensure the interrupt is disabled | |
414 | * on the card it drives before calling this function. The function | |
415 | * does not return until any executing interrupts for this IRQ | |
416 | * have completed. | |
417 | * | |
418 | * This function must not be called from interrupt context. | |
419 | */ | |
420 | void free_irq(unsigned int irq, void *dev_id) | |
421 | { | |
422 | struct irq_desc *desc; | |
423 | struct irqaction **p; | |
424 | unsigned long flags; | |
425 | ||
cd7b24bb | 426 | WARN_ON(in_interrupt()); |
1da177e4 LT |
427 | if (irq >= NR_IRQS) |
428 | return; | |
429 | ||
430 | desc = irq_desc + irq; | |
06fcb0c6 | 431 | spin_lock_irqsave(&desc->lock, flags); |
1da177e4 LT |
432 | p = &desc->action; |
433 | for (;;) { | |
06fcb0c6 | 434 | struct irqaction *action = *p; |
1da177e4 LT |
435 | |
436 | if (action) { | |
437 | struct irqaction **pp = p; | |
438 | ||
439 | p = &action->next; | |
440 | if (action->dev_id != dev_id) | |
441 | continue; | |
442 | ||
443 | /* Found it - now remove it from the list of entries */ | |
444 | *pp = action->next; | |
dbce706e | 445 | |
b77d6adc PBG |
446 | /* Currently used only by UML, might disappear one day.*/ |
447 | #ifdef CONFIG_IRQ_RELEASE_METHOD | |
d1bef4ed IM |
448 | if (desc->chip->release) |
449 | desc->chip->release(irq, dev_id); | |
b77d6adc | 450 | #endif |
dbce706e | 451 | |
1da177e4 LT |
452 | if (!desc->action) { |
453 | desc->status |= IRQ_DISABLED; | |
d1bef4ed IM |
454 | if (desc->chip->shutdown) |
455 | desc->chip->shutdown(irq); | |
1da177e4 | 456 | else |
d1bef4ed | 457 | desc->chip->disable(irq); |
1da177e4 | 458 | } |
06fcb0c6 | 459 | spin_unlock_irqrestore(&desc->lock, flags); |
1da177e4 LT |
460 | unregister_handler_proc(irq, action); |
461 | ||
462 | /* Make sure it's not being used on another CPU */ | |
463 | synchronize_irq(irq); | |
1d99493b DW |
464 | #ifdef CONFIG_DEBUG_SHIRQ |
465 | /* | |
466 | * It's a shared IRQ -- the driver ought to be | |
467 | * prepared for it to happen even now it's | |
468 | * being freed, so let's make sure.... We do | |
469 | * this after actually deregistering it, to | |
470 | * make sure that a 'real' IRQ doesn't run in | |
471 | * parallel with our fake | |
472 | */ | |
473 | if (action->flags & IRQF_SHARED) { | |
474 | local_irq_save(flags); | |
475 | action->handler(irq, dev_id); | |
476 | local_irq_restore(flags); | |
477 | } | |
478 | #endif | |
1da177e4 LT |
479 | kfree(action); |
480 | return; | |
481 | } | |
e8c4b9d0 | 482 | printk(KERN_ERR "Trying to free already-free IRQ %d\n", irq); |
70edcd77 IM |
483 | #ifdef CONFIG_DEBUG_SHIRQ |
484 | dump_stack(); | |
485 | #endif | |
06fcb0c6 | 486 | spin_unlock_irqrestore(&desc->lock, flags); |
1da177e4 LT |
487 | return; |
488 | } | |
489 | } | |
1da177e4 LT |
490 | EXPORT_SYMBOL(free_irq); |
491 | ||
492 | /** | |
493 | * request_irq - allocate an interrupt line | |
494 | * @irq: Interrupt line to allocate | |
495 | * @handler: Function to be called when the IRQ occurs | |
496 | * @irqflags: Interrupt type flags | |
497 | * @devname: An ascii name for the claiming device | |
498 | * @dev_id: A cookie passed back to the handler function | |
499 | * | |
500 | * This call allocates interrupt resources and enables the | |
501 | * interrupt line and IRQ handling. From the point this | |
502 | * call is made your handler function may be invoked. Since | |
503 | * your handler function must clear any interrupt the board | |
504 | * raises, you must take care both to initialise your hardware | |
505 | * and to set up the interrupt handler in the right order. | |
506 | * | |
507 | * Dev_id must be globally unique. Normally the address of the | |
508 | * device data structure is used as the cookie. Since the handler | |
509 | * receives this value it makes sense to use it. | |
510 | * | |
511 | * If your interrupt is shared you must pass a non NULL dev_id | |
512 | * as this is required when freeing the interrupt. | |
513 | * | |
514 | * Flags: | |
515 | * | |
3cca53b0 TG |
516 | * IRQF_SHARED Interrupt is shared |
517 | * IRQF_DISABLED Disable local interrupts while processing | |
518 | * IRQF_SAMPLE_RANDOM The interrupt can be used for entropy | |
1da177e4 LT |
519 | * |
520 | */ | |
da482792 | 521 | int request_irq(unsigned int irq, irq_handler_t handler, |
06fcb0c6 | 522 | unsigned long irqflags, const char *devname, void *dev_id) |
1da177e4 | 523 | { |
06fcb0c6 | 524 | struct irqaction *action; |
1da177e4 LT |
525 | int retval; |
526 | ||
fbb9ce95 IM |
527 | #ifdef CONFIG_LOCKDEP |
528 | /* | |
529 | * Lockdep wants atomic interrupt handlers: | |
530 | */ | |
38515e90 | 531 | irqflags |= IRQF_DISABLED; |
fbb9ce95 | 532 | #endif |
1da177e4 LT |
533 | /* |
534 | * Sanity-check: shared interrupts must pass in a real dev-ID, | |
535 | * otherwise we'll have trouble later trying to figure out | |
536 | * which interrupt is which (messes up the interrupt freeing | |
537 | * logic etc). | |
538 | */ | |
3cca53b0 | 539 | if ((irqflags & IRQF_SHARED) && !dev_id) |
1da177e4 LT |
540 | return -EINVAL; |
541 | if (irq >= NR_IRQS) | |
542 | return -EINVAL; | |
6550c775 TG |
543 | if (irq_desc[irq].status & IRQ_NOREQUEST) |
544 | return -EINVAL; | |
1da177e4 LT |
545 | if (!handler) |
546 | return -EINVAL; | |
547 | ||
548 | action = kmalloc(sizeof(struct irqaction), GFP_ATOMIC); | |
549 | if (!action) | |
550 | return -ENOMEM; | |
551 | ||
552 | action->handler = handler; | |
553 | action->flags = irqflags; | |
554 | cpus_clear(action->mask); | |
555 | action->name = devname; | |
556 | action->next = NULL; | |
557 | action->dev_id = dev_id; | |
558 | ||
eee45269 IK |
559 | select_smp_affinity(irq); |
560 | ||
a304e1b8 DW |
561 | #ifdef CONFIG_DEBUG_SHIRQ |
562 | if (irqflags & IRQF_SHARED) { | |
563 | /* | |
564 | * It's a shared IRQ -- the driver ought to be prepared for it | |
565 | * to happen immediately, so let's make sure.... | |
566 | * We do this before actually registering it, to make sure that | |
567 | * a 'real' IRQ doesn't run in parallel with our fake | |
568 | */ | |
59845b1f | 569 | unsigned long flags; |
a304e1b8 | 570 | |
59845b1f JP |
571 | local_irq_save(flags); |
572 | handler(irq, dev_id); | |
573 | local_irq_restore(flags); | |
a304e1b8 DW |
574 | } |
575 | #endif | |
576 | ||
1da177e4 LT |
577 | retval = setup_irq(irq, action); |
578 | if (retval) | |
579 | kfree(action); | |
580 | ||
581 | return retval; | |
582 | } | |
1da177e4 | 583 | EXPORT_SYMBOL(request_irq); |