Commit | Line | Data |
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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> | |
14 | ||
15 | #include "internals.h" | |
16 | ||
17 | #ifdef CONFIG_SMP | |
18 | ||
1da177e4 LT |
19 | /** |
20 | * synchronize_irq - wait for pending IRQ handlers (on other CPUs) | |
1e5d5331 | 21 | * @irq: interrupt number to wait for |
1da177e4 LT |
22 | * |
23 | * This function waits for any pending IRQ handlers for this interrupt | |
24 | * to complete before returning. If you use this function while | |
25 | * holding a resource the IRQ handler may need you will deadlock. | |
26 | * | |
27 | * This function may be called - with care - from IRQ context. | |
28 | */ | |
29 | void synchronize_irq(unsigned int irq) | |
30 | { | |
31 | struct irq_desc *desc = irq_desc + irq; | |
a98ce5c6 | 32 | unsigned int status; |
1da177e4 | 33 | |
c2b5a251 MW |
34 | if (irq >= NR_IRQS) |
35 | return; | |
36 | ||
a98ce5c6 HX |
37 | do { |
38 | unsigned long flags; | |
39 | ||
40 | /* | |
41 | * Wait until we're out of the critical section. This might | |
42 | * give the wrong answer due to the lack of memory barriers. | |
43 | */ | |
44 | while (desc->status & IRQ_INPROGRESS) | |
45 | cpu_relax(); | |
46 | ||
47 | /* Ok, that indicated we're done: double-check carefully. */ | |
48 | spin_lock_irqsave(&desc->lock, flags); | |
49 | status = desc->status; | |
50 | spin_unlock_irqrestore(&desc->lock, flags); | |
51 | ||
52 | /* Oops, that failed? */ | |
53 | } while (status & IRQ_INPROGRESS); | |
1da177e4 | 54 | } |
1da177e4 LT |
55 | EXPORT_SYMBOL(synchronize_irq); |
56 | ||
771ee3b0 TG |
57 | /** |
58 | * irq_can_set_affinity - Check if the affinity of a given irq can be set | |
59 | * @irq: Interrupt to check | |
60 | * | |
61 | */ | |
62 | int irq_can_set_affinity(unsigned int irq) | |
63 | { | |
64 | struct irq_desc *desc = irq_desc + irq; | |
65 | ||
66 | if (CHECK_IRQ_PER_CPU(desc->status) || !desc->chip || | |
67 | !desc->chip->set_affinity) | |
68 | return 0; | |
69 | ||
70 | return 1; | |
71 | } | |
72 | ||
73 | /** | |
74 | * irq_set_affinity - Set the irq affinity of a given irq | |
75 | * @irq: Interrupt to set affinity | |
76 | * @cpumask: cpumask | |
77 | * | |
78 | */ | |
79 | int irq_set_affinity(unsigned int irq, cpumask_t cpumask) | |
80 | { | |
81 | struct irq_desc *desc = irq_desc + irq; | |
82 | ||
83 | if (!desc->chip->set_affinity) | |
84 | return -EINVAL; | |
85 | ||
86 | set_balance_irq_affinity(irq, cpumask); | |
87 | ||
88 | #ifdef CONFIG_GENERIC_PENDING_IRQ | |
89 | set_pending_irq(irq, cpumask); | |
90 | #else | |
91 | desc->affinity = cpumask; | |
92 | desc->chip->set_affinity(irq, cpumask); | |
93 | #endif | |
94 | return 0; | |
95 | } | |
96 | ||
1da177e4 LT |
97 | #endif |
98 | ||
99 | /** | |
100 | * disable_irq_nosync - disable an irq without waiting | |
101 | * @irq: Interrupt to disable | |
102 | * | |
103 | * Disable the selected interrupt line. Disables and Enables are | |
104 | * nested. | |
105 | * Unlike disable_irq(), this function does not ensure existing | |
106 | * instances of the IRQ handler have completed before returning. | |
107 | * | |
108 | * This function may be called from IRQ context. | |
109 | */ | |
110 | void disable_irq_nosync(unsigned int irq) | |
111 | { | |
34ffdb72 | 112 | struct irq_desc *desc = irq_desc + irq; |
1da177e4 LT |
113 | unsigned long flags; |
114 | ||
c2b5a251 MW |
115 | if (irq >= NR_IRQS) |
116 | return; | |
117 | ||
1da177e4 LT |
118 | spin_lock_irqsave(&desc->lock, flags); |
119 | if (!desc->depth++) { | |
120 | desc->status |= IRQ_DISABLED; | |
d1bef4ed | 121 | desc->chip->disable(irq); |
1da177e4 LT |
122 | } |
123 | spin_unlock_irqrestore(&desc->lock, flags); | |
124 | } | |
1da177e4 LT |
125 | EXPORT_SYMBOL(disable_irq_nosync); |
126 | ||
127 | /** | |
128 | * disable_irq - disable an irq and wait for completion | |
129 | * @irq: Interrupt to disable | |
130 | * | |
131 | * Disable the selected interrupt line. Enables and Disables are | |
132 | * nested. | |
133 | * This function waits for any pending IRQ handlers for this interrupt | |
134 | * to complete before returning. If you use this function while | |
135 | * holding a resource the IRQ handler may need you will deadlock. | |
136 | * | |
137 | * This function may be called - with care - from IRQ context. | |
138 | */ | |
139 | void disable_irq(unsigned int irq) | |
140 | { | |
34ffdb72 | 141 | struct irq_desc *desc = irq_desc + irq; |
1da177e4 | 142 | |
c2b5a251 MW |
143 | if (irq >= NR_IRQS) |
144 | return; | |
145 | ||
1da177e4 LT |
146 | disable_irq_nosync(irq); |
147 | if (desc->action) | |
148 | synchronize_irq(irq); | |
149 | } | |
1da177e4 LT |
150 | EXPORT_SYMBOL(disable_irq); |
151 | ||
152 | /** | |
153 | * enable_irq - enable handling of an irq | |
154 | * @irq: Interrupt to enable | |
155 | * | |
156 | * Undoes the effect of one call to disable_irq(). If this | |
157 | * matches the last disable, processing of interrupts on this | |
158 | * IRQ line is re-enabled. | |
159 | * | |
160 | * This function may be called from IRQ context. | |
161 | */ | |
162 | void enable_irq(unsigned int irq) | |
163 | { | |
34ffdb72 | 164 | struct irq_desc *desc = irq_desc + irq; |
1da177e4 LT |
165 | unsigned long flags; |
166 | ||
c2b5a251 MW |
167 | if (irq >= NR_IRQS) |
168 | return; | |
169 | ||
1da177e4 LT |
170 | spin_lock_irqsave(&desc->lock, flags); |
171 | switch (desc->depth) { | |
172 | case 0: | |
e8c4b9d0 | 173 | printk(KERN_WARNING "Unbalanced enable for IRQ %d\n", irq); |
1da177e4 LT |
174 | WARN_ON(1); |
175 | break; | |
176 | case 1: { | |
3418d724 TG |
177 | unsigned int status = desc->status & ~IRQ_DISABLED; |
178 | ||
179 | /* Prevent probing on this irq: */ | |
180 | desc->status = status | IRQ_NOPROBE; | |
a4633adc | 181 | check_irq_resend(desc, irq); |
1da177e4 LT |
182 | /* fall-through */ |
183 | } | |
184 | default: | |
185 | desc->depth--; | |
186 | } | |
187 | spin_unlock_irqrestore(&desc->lock, flags); | |
188 | } | |
1da177e4 LT |
189 | EXPORT_SYMBOL(enable_irq); |
190 | ||
ba9a2331 TG |
191 | /** |
192 | * set_irq_wake - control irq power management wakeup | |
193 | * @irq: interrupt to control | |
194 | * @on: enable/disable power management wakeup | |
195 | * | |
15a647eb DB |
196 | * Enable/disable power management wakeup mode, which is |
197 | * disabled by default. Enables and disables must match, | |
198 | * just as they match for non-wakeup mode support. | |
199 | * | |
200 | * Wakeup mode lets this IRQ wake the system from sleep | |
201 | * states like "suspend to RAM". | |
ba9a2331 TG |
202 | */ |
203 | int set_irq_wake(unsigned int irq, unsigned int on) | |
204 | { | |
205 | struct irq_desc *desc = irq_desc + irq; | |
206 | unsigned long flags; | |
207 | int ret = -ENXIO; | |
15a647eb | 208 | int (*set_wake)(unsigned, unsigned) = desc->chip->set_wake; |
ba9a2331 | 209 | |
15a647eb DB |
210 | /* wakeup-capable irqs can be shared between drivers that |
211 | * don't need to have the same sleep mode behaviors. | |
212 | */ | |
ba9a2331 | 213 | spin_lock_irqsave(&desc->lock, flags); |
15a647eb DB |
214 | if (on) { |
215 | if (desc->wake_depth++ == 0) | |
216 | desc->status |= IRQ_WAKEUP; | |
217 | else | |
218 | set_wake = NULL; | |
219 | } else { | |
220 | if (desc->wake_depth == 0) { | |
221 | printk(KERN_WARNING "Unbalanced IRQ %d " | |
222 | "wake disable\n", irq); | |
223 | WARN_ON(1); | |
224 | } else if (--desc->wake_depth == 0) | |
225 | desc->status &= ~IRQ_WAKEUP; | |
226 | else | |
227 | set_wake = NULL; | |
228 | } | |
229 | if (set_wake) | |
ba9a2331 TG |
230 | ret = desc->chip->set_wake(irq, on); |
231 | spin_unlock_irqrestore(&desc->lock, flags); | |
232 | return ret; | |
233 | } | |
234 | EXPORT_SYMBOL(set_irq_wake); | |
235 | ||
1da177e4 LT |
236 | /* |
237 | * Internal function that tells the architecture code whether a | |
238 | * particular irq has been exclusively allocated or is available | |
239 | * for driver use. | |
240 | */ | |
241 | int can_request_irq(unsigned int irq, unsigned long irqflags) | |
242 | { | |
243 | struct irqaction *action; | |
244 | ||
6550c775 | 245 | if (irq >= NR_IRQS || irq_desc[irq].status & IRQ_NOREQUEST) |
1da177e4 LT |
246 | return 0; |
247 | ||
248 | action = irq_desc[irq].action; | |
249 | if (action) | |
3cca53b0 | 250 | if (irqflags & action->flags & IRQF_SHARED) |
1da177e4 LT |
251 | action = NULL; |
252 | ||
253 | return !action; | |
254 | } | |
255 | ||
6a6de9ef TG |
256 | void compat_irq_chip_set_default_handler(struct irq_desc *desc) |
257 | { | |
258 | /* | |
259 | * If the architecture still has not overriden | |
260 | * the flow handler then zap the default. This | |
261 | * should catch incorrect flow-type setting. | |
262 | */ | |
263 | if (desc->handle_irq == &handle_bad_irq) | |
264 | desc->handle_irq = NULL; | |
265 | } | |
266 | ||
1da177e4 LT |
267 | /* |
268 | * Internal function to register an irqaction - typically used to | |
269 | * allocate special interrupts that are part of the architecture. | |
270 | */ | |
06fcb0c6 | 271 | int setup_irq(unsigned int irq, struct irqaction *new) |
1da177e4 LT |
272 | { |
273 | struct irq_desc *desc = irq_desc + irq; | |
274 | struct irqaction *old, **p; | |
8b126b77 | 275 | const char *old_name = NULL; |
1da177e4 LT |
276 | unsigned long flags; |
277 | int shared = 0; | |
278 | ||
c2b5a251 MW |
279 | if (irq >= NR_IRQS) |
280 | return -EINVAL; | |
281 | ||
f1c2662c | 282 | if (desc->chip == &no_irq_chip) |
1da177e4 LT |
283 | return -ENOSYS; |
284 | /* | |
285 | * Some drivers like serial.c use request_irq() heavily, | |
286 | * so we have to be careful not to interfere with a | |
287 | * running system. | |
288 | */ | |
3cca53b0 | 289 | if (new->flags & IRQF_SAMPLE_RANDOM) { |
1da177e4 LT |
290 | /* |
291 | * This function might sleep, we want to call it first, | |
292 | * outside of the atomic block. | |
293 | * Yes, this might clear the entropy pool if the wrong | |
294 | * driver is attempted to be loaded, without actually | |
295 | * installing a new handler, but is this really a problem, | |
296 | * only the sysadmin is able to do this. | |
297 | */ | |
298 | rand_initialize_irq(irq); | |
299 | } | |
300 | ||
301 | /* | |
302 | * The following block of code has to be executed atomically | |
303 | */ | |
06fcb0c6 | 304 | spin_lock_irqsave(&desc->lock, flags); |
1da177e4 | 305 | p = &desc->action; |
06fcb0c6 IM |
306 | old = *p; |
307 | if (old) { | |
e76de9f8 TG |
308 | /* |
309 | * Can't share interrupts unless both agree to and are | |
310 | * the same type (level, edge, polarity). So both flag | |
3cca53b0 | 311 | * fields must have IRQF_SHARED set and the bits which |
e76de9f8 TG |
312 | * set the trigger type must match. |
313 | */ | |
3cca53b0 | 314 | if (!((old->flags & new->flags) & IRQF_SHARED) || |
8b126b77 AM |
315 | ((old->flags ^ new->flags) & IRQF_TRIGGER_MASK)) { |
316 | old_name = old->name; | |
f5163427 | 317 | goto mismatch; |
8b126b77 | 318 | } |
f5163427 | 319 | |
284c6680 | 320 | #if defined(CONFIG_IRQ_PER_CPU) |
f5163427 | 321 | /* All handlers must agree on per-cpuness */ |
3cca53b0 TG |
322 | if ((old->flags & IRQF_PERCPU) != |
323 | (new->flags & IRQF_PERCPU)) | |
f5163427 DS |
324 | goto mismatch; |
325 | #endif | |
1da177e4 LT |
326 | |
327 | /* add new interrupt at end of irq queue */ | |
328 | do { | |
329 | p = &old->next; | |
330 | old = *p; | |
331 | } while (old); | |
332 | shared = 1; | |
333 | } | |
334 | ||
335 | *p = new; | |
f75d222b | 336 | |
950f4427 TG |
337 | /* Exclude IRQ from balancing */ |
338 | if (new->flags & IRQF_NOBALANCING) | |
339 | desc->status |= IRQ_NO_BALANCING; | |
340 | ||
1da177e4 | 341 | if (!shared) { |
6a6de9ef | 342 | irq_chip_set_defaults(desc->chip); |
e76de9f8 | 343 | |
f75d222b AD |
344 | #if defined(CONFIG_IRQ_PER_CPU) |
345 | if (new->flags & IRQF_PERCPU) | |
346 | desc->status |= IRQ_PER_CPU; | |
347 | #endif | |
348 | ||
e76de9f8 | 349 | /* Setup the type (level, edge polarity) if configured: */ |
3cca53b0 | 350 | if (new->flags & IRQF_TRIGGER_MASK) { |
e76de9f8 TG |
351 | if (desc->chip && desc->chip->set_type) |
352 | desc->chip->set_type(irq, | |
3cca53b0 | 353 | new->flags & IRQF_TRIGGER_MASK); |
e76de9f8 TG |
354 | else |
355 | /* | |
3cca53b0 | 356 | * IRQF_TRIGGER_* but the PIC does not support |
e76de9f8 TG |
357 | * multiple flow-types? |
358 | */ | |
3cca53b0 | 359 | printk(KERN_WARNING "No IRQF_TRIGGER set_type " |
e8c4b9d0 BH |
360 | "function for IRQ %d (%s)\n", irq, |
361 | desc->chip ? desc->chip->name : | |
362 | "unknown"); | |
e76de9f8 TG |
363 | } else |
364 | compat_irq_chip_set_default_handler(desc); | |
6a6de9ef | 365 | |
94d39e1f TG |
366 | desc->status &= ~(IRQ_AUTODETECT | IRQ_WAITING | |
367 | IRQ_INPROGRESS); | |
368 | ||
369 | if (!(desc->status & IRQ_NOAUTOEN)) { | |
370 | desc->depth = 0; | |
371 | desc->status &= ~IRQ_DISABLED; | |
372 | if (desc->chip->startup) | |
373 | desc->chip->startup(irq); | |
374 | else | |
375 | desc->chip->enable(irq); | |
e76de9f8 TG |
376 | } else |
377 | /* Undo nested disables: */ | |
378 | desc->depth = 1; | |
1da177e4 | 379 | } |
8528b0f1 LT |
380 | /* Reset broken irq detection when installing new handler */ |
381 | desc->irq_count = 0; | |
382 | desc->irqs_unhandled = 0; | |
06fcb0c6 | 383 | spin_unlock_irqrestore(&desc->lock, flags); |
1da177e4 LT |
384 | |
385 | new->irq = irq; | |
386 | register_irq_proc(irq); | |
387 | new->dir = NULL; | |
388 | register_handler_proc(irq, new); | |
389 | ||
390 | return 0; | |
f5163427 DS |
391 | |
392 | mismatch: | |
3f050447 | 393 | #ifdef CONFIG_DEBUG_SHIRQ |
3cca53b0 | 394 | if (!(new->flags & IRQF_PROBE_SHARED)) { |
e8c4b9d0 | 395 | printk(KERN_ERR "IRQ handler type mismatch for IRQ %d\n", irq); |
8b126b77 AM |
396 | if (old_name) |
397 | printk(KERN_ERR "current handler: %s\n", old_name); | |
13e87ec6 AM |
398 | dump_stack(); |
399 | } | |
3f050447 | 400 | #endif |
8b126b77 | 401 | spin_unlock_irqrestore(&desc->lock, flags); |
f5163427 | 402 | return -EBUSY; |
1da177e4 LT |
403 | } |
404 | ||
405 | /** | |
406 | * free_irq - free an interrupt | |
407 | * @irq: Interrupt line to free | |
408 | * @dev_id: Device identity to free | |
409 | * | |
410 | * Remove an interrupt handler. The handler is removed and if the | |
411 | * interrupt line is no longer in use by any driver it is disabled. | |
412 | * On a shared IRQ the caller must ensure the interrupt is disabled | |
413 | * on the card it drives before calling this function. The function | |
414 | * does not return until any executing interrupts for this IRQ | |
415 | * have completed. | |
416 | * | |
417 | * This function must not be called from interrupt context. | |
418 | */ | |
419 | void free_irq(unsigned int irq, void *dev_id) | |
420 | { | |
421 | struct irq_desc *desc; | |
422 | struct irqaction **p; | |
423 | unsigned long flags; | |
424 | ||
cd7b24bb | 425 | WARN_ON(in_interrupt()); |
1da177e4 LT |
426 | if (irq >= NR_IRQS) |
427 | return; | |
428 | ||
429 | desc = irq_desc + irq; | |
06fcb0c6 | 430 | spin_lock_irqsave(&desc->lock, flags); |
1da177e4 LT |
431 | p = &desc->action; |
432 | for (;;) { | |
06fcb0c6 | 433 | struct irqaction *action = *p; |
1da177e4 LT |
434 | |
435 | if (action) { | |
436 | struct irqaction **pp = p; | |
437 | ||
438 | p = &action->next; | |
439 | if (action->dev_id != dev_id) | |
440 | continue; | |
441 | ||
442 | /* Found it - now remove it from the list of entries */ | |
443 | *pp = action->next; | |
dbce706e | 444 | |
b77d6adc PBG |
445 | /* Currently used only by UML, might disappear one day.*/ |
446 | #ifdef CONFIG_IRQ_RELEASE_METHOD | |
d1bef4ed IM |
447 | if (desc->chip->release) |
448 | desc->chip->release(irq, dev_id); | |
b77d6adc | 449 | #endif |
dbce706e | 450 | |
1da177e4 LT |
451 | if (!desc->action) { |
452 | desc->status |= IRQ_DISABLED; | |
d1bef4ed IM |
453 | if (desc->chip->shutdown) |
454 | desc->chip->shutdown(irq); | |
1da177e4 | 455 | else |
d1bef4ed | 456 | desc->chip->disable(irq); |
1da177e4 | 457 | } |
06fcb0c6 | 458 | spin_unlock_irqrestore(&desc->lock, flags); |
1da177e4 LT |
459 | unregister_handler_proc(irq, action); |
460 | ||
461 | /* Make sure it's not being used on another CPU */ | |
462 | synchronize_irq(irq); | |
1d99493b DW |
463 | #ifdef CONFIG_DEBUG_SHIRQ |
464 | /* | |
465 | * It's a shared IRQ -- the driver ought to be | |
466 | * prepared for it to happen even now it's | |
467 | * being freed, so let's make sure.... We do | |
468 | * this after actually deregistering it, to | |
469 | * make sure that a 'real' IRQ doesn't run in | |
470 | * parallel with our fake | |
471 | */ | |
472 | if (action->flags & IRQF_SHARED) { | |
473 | local_irq_save(flags); | |
474 | action->handler(irq, dev_id); | |
475 | local_irq_restore(flags); | |
476 | } | |
477 | #endif | |
1da177e4 LT |
478 | kfree(action); |
479 | return; | |
480 | } | |
e8c4b9d0 | 481 | printk(KERN_ERR "Trying to free already-free IRQ %d\n", irq); |
70edcd77 IM |
482 | #ifdef CONFIG_DEBUG_SHIRQ |
483 | dump_stack(); | |
484 | #endif | |
06fcb0c6 | 485 | spin_unlock_irqrestore(&desc->lock, flags); |
1da177e4 LT |
486 | return; |
487 | } | |
488 | } | |
1da177e4 LT |
489 | EXPORT_SYMBOL(free_irq); |
490 | ||
491 | /** | |
492 | * request_irq - allocate an interrupt line | |
493 | * @irq: Interrupt line to allocate | |
494 | * @handler: Function to be called when the IRQ occurs | |
495 | * @irqflags: Interrupt type flags | |
496 | * @devname: An ascii name for the claiming device | |
497 | * @dev_id: A cookie passed back to the handler function | |
498 | * | |
499 | * This call allocates interrupt resources and enables the | |
500 | * interrupt line and IRQ handling. From the point this | |
501 | * call is made your handler function may be invoked. Since | |
502 | * your handler function must clear any interrupt the board | |
503 | * raises, you must take care both to initialise your hardware | |
504 | * and to set up the interrupt handler in the right order. | |
505 | * | |
506 | * Dev_id must be globally unique. Normally the address of the | |
507 | * device data structure is used as the cookie. Since the handler | |
508 | * receives this value it makes sense to use it. | |
509 | * | |
510 | * If your interrupt is shared you must pass a non NULL dev_id | |
511 | * as this is required when freeing the interrupt. | |
512 | * | |
513 | * Flags: | |
514 | * | |
3cca53b0 TG |
515 | * IRQF_SHARED Interrupt is shared |
516 | * IRQF_DISABLED Disable local interrupts while processing | |
517 | * IRQF_SAMPLE_RANDOM The interrupt can be used for entropy | |
1da177e4 LT |
518 | * |
519 | */ | |
da482792 | 520 | int request_irq(unsigned int irq, irq_handler_t handler, |
06fcb0c6 | 521 | unsigned long irqflags, const char *devname, void *dev_id) |
1da177e4 | 522 | { |
06fcb0c6 | 523 | struct irqaction *action; |
1da177e4 LT |
524 | int retval; |
525 | ||
fbb9ce95 IM |
526 | #ifdef CONFIG_LOCKDEP |
527 | /* | |
528 | * Lockdep wants atomic interrupt handlers: | |
529 | */ | |
38515e90 | 530 | irqflags |= IRQF_DISABLED; |
fbb9ce95 | 531 | #endif |
1da177e4 LT |
532 | /* |
533 | * Sanity-check: shared interrupts must pass in a real dev-ID, | |
534 | * otherwise we'll have trouble later trying to figure out | |
535 | * which interrupt is which (messes up the interrupt freeing | |
536 | * logic etc). | |
537 | */ | |
3cca53b0 | 538 | if ((irqflags & IRQF_SHARED) && !dev_id) |
1da177e4 LT |
539 | return -EINVAL; |
540 | if (irq >= NR_IRQS) | |
541 | return -EINVAL; | |
6550c775 TG |
542 | if (irq_desc[irq].status & IRQ_NOREQUEST) |
543 | return -EINVAL; | |
1da177e4 LT |
544 | if (!handler) |
545 | return -EINVAL; | |
546 | ||
547 | action = kmalloc(sizeof(struct irqaction), GFP_ATOMIC); | |
548 | if (!action) | |
549 | return -ENOMEM; | |
550 | ||
551 | action->handler = handler; | |
552 | action->flags = irqflags; | |
553 | cpus_clear(action->mask); | |
554 | action->name = devname; | |
555 | action->next = NULL; | |
556 | action->dev_id = dev_id; | |
557 | ||
eee45269 IK |
558 | select_smp_affinity(irq); |
559 | ||
a304e1b8 DW |
560 | #ifdef CONFIG_DEBUG_SHIRQ |
561 | if (irqflags & IRQF_SHARED) { | |
562 | /* | |
563 | * It's a shared IRQ -- the driver ought to be prepared for it | |
564 | * to happen immediately, so let's make sure.... | |
565 | * We do this before actually registering it, to make sure that | |
566 | * a 'real' IRQ doesn't run in parallel with our fake | |
567 | */ | |
59845b1f | 568 | unsigned long flags; |
a304e1b8 | 569 | |
59845b1f JP |
570 | local_irq_save(flags); |
571 | handler(irq, dev_id); | |
572 | local_irq_restore(flags); | |
a304e1b8 DW |
573 | } |
574 | #endif | |
575 | ||
1da177e4 LT |
576 | retval = setup_irq(irq, action); |
577 | if (retval) | |
578 | kfree(action); | |
579 | ||
580 | return retval; | |
581 | } | |
1da177e4 | 582 | EXPORT_SYMBOL(request_irq); |