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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> | |
1aeb272c | 14 | #include <linux/slab.h> |
1da177e4 LT |
15 | |
16 | #include "internals.h" | |
17 | ||
1267a8df | 18 | #if defined(CONFIG_SMP) && defined(CONFIG_GENERIC_HARDIRQS) |
d036e67b | 19 | cpumask_var_t irq_default_affinity; |
1da177e4 | 20 | |
1da177e4 LT |
21 | /** |
22 | * synchronize_irq - wait for pending IRQ handlers (on other CPUs) | |
1e5d5331 | 23 | * @irq: interrupt number to wait for |
1da177e4 LT |
24 | * |
25 | * This function waits for any pending IRQ handlers for this interrupt | |
26 | * to complete before returning. If you use this function while | |
27 | * holding a resource the IRQ handler may need you will deadlock. | |
28 | * | |
29 | * This function may be called - with care - from IRQ context. | |
30 | */ | |
31 | void synchronize_irq(unsigned int irq) | |
32 | { | |
cb5bc832 | 33 | struct irq_desc *desc = irq_to_desc(irq); |
a98ce5c6 | 34 | unsigned int status; |
1da177e4 | 35 | |
7d94f7ca | 36 | if (!desc) |
c2b5a251 MW |
37 | return; |
38 | ||
a98ce5c6 HX |
39 | do { |
40 | unsigned long flags; | |
41 | ||
42 | /* | |
43 | * Wait until we're out of the critical section. This might | |
44 | * give the wrong answer due to the lack of memory barriers. | |
45 | */ | |
46 | while (desc->status & IRQ_INPROGRESS) | |
47 | cpu_relax(); | |
48 | ||
49 | /* Ok, that indicated we're done: double-check carefully. */ | |
50 | spin_lock_irqsave(&desc->lock, flags); | |
51 | status = desc->status; | |
52 | spin_unlock_irqrestore(&desc->lock, flags); | |
53 | ||
54 | /* Oops, that failed? */ | |
55 | } while (status & IRQ_INPROGRESS); | |
1da177e4 | 56 | } |
1da177e4 LT |
57 | EXPORT_SYMBOL(synchronize_irq); |
58 | ||
771ee3b0 TG |
59 | /** |
60 | * irq_can_set_affinity - Check if the affinity of a given irq can be set | |
61 | * @irq: Interrupt to check | |
62 | * | |
63 | */ | |
64 | int irq_can_set_affinity(unsigned int irq) | |
65 | { | |
08678b08 | 66 | struct irq_desc *desc = irq_to_desc(irq); |
771ee3b0 TG |
67 | |
68 | if (CHECK_IRQ_PER_CPU(desc->status) || !desc->chip || | |
69 | !desc->chip->set_affinity) | |
70 | return 0; | |
71 | ||
72 | return 1; | |
73 | } | |
74 | ||
75 | /** | |
76 | * irq_set_affinity - Set the irq affinity of a given irq | |
77 | * @irq: Interrupt to set affinity | |
78 | * @cpumask: cpumask | |
79 | * | |
80 | */ | |
0de26520 | 81 | int irq_set_affinity(unsigned int irq, const struct cpumask *cpumask) |
771ee3b0 | 82 | { |
08678b08 | 83 | struct irq_desc *desc = irq_to_desc(irq); |
f6d87f4b | 84 | unsigned long flags; |
771ee3b0 TG |
85 | |
86 | if (!desc->chip->set_affinity) | |
87 | return -EINVAL; | |
88 | ||
f6d87f4b TG |
89 | spin_lock_irqsave(&desc->lock, flags); |
90 | ||
771ee3b0 | 91 | #ifdef CONFIG_GENERIC_PENDING_IRQ |
932775a4 | 92 | if (desc->status & IRQ_MOVE_PCNTXT || desc->status & IRQ_DISABLED) { |
0de26520 | 93 | cpumask_copy(&desc->affinity, cpumask); |
72b1e22d | 94 | desc->chip->set_affinity(irq, cpumask); |
f6d87f4b TG |
95 | } else { |
96 | desc->status |= IRQ_MOVE_PENDING; | |
0de26520 | 97 | cpumask_copy(&desc->pending_mask, cpumask); |
f6d87f4b | 98 | } |
771ee3b0 | 99 | #else |
0de26520 | 100 | cpumask_copy(&desc->affinity, cpumask); |
771ee3b0 TG |
101 | desc->chip->set_affinity(irq, cpumask); |
102 | #endif | |
f6d87f4b TG |
103 | desc->status |= IRQ_AFFINITY_SET; |
104 | spin_unlock_irqrestore(&desc->lock, flags); | |
771ee3b0 TG |
105 | return 0; |
106 | } | |
107 | ||
18404756 MK |
108 | #ifndef CONFIG_AUTO_IRQ_AFFINITY |
109 | /* | |
110 | * Generic version of the affinity autoselector. | |
111 | */ | |
f6d87f4b | 112 | int do_irq_select_affinity(unsigned int irq, struct irq_desc *desc) |
18404756 | 113 | { |
18404756 MK |
114 | if (!irq_can_set_affinity(irq)) |
115 | return 0; | |
116 | ||
f6d87f4b TG |
117 | /* |
118 | * Preserve an userspace affinity setup, but make sure that | |
119 | * one of the targets is online. | |
120 | */ | |
612e3684 | 121 | if (desc->status & (IRQ_AFFINITY_SET | IRQ_NO_BALANCING)) { |
0de26520 RR |
122 | if (cpumask_any_and(&desc->affinity, cpu_online_mask) |
123 | < nr_cpu_ids) | |
124 | goto set_affinity; | |
f6d87f4b TG |
125 | else |
126 | desc->status &= ~IRQ_AFFINITY_SET; | |
127 | } | |
128 | ||
d036e67b | 129 | cpumask_and(&desc->affinity, cpu_online_mask, irq_default_affinity); |
0de26520 RR |
130 | set_affinity: |
131 | desc->chip->set_affinity(irq, &desc->affinity); | |
18404756 | 132 | |
18404756 MK |
133 | return 0; |
134 | } | |
f6d87f4b TG |
135 | #else |
136 | static inline int do_irq_select_affinity(unsigned int irq, struct irq_desc *d) | |
137 | { | |
138 | return irq_select_affinity(irq); | |
139 | } | |
18404756 MK |
140 | #endif |
141 | ||
f6d87f4b TG |
142 | /* |
143 | * Called when affinity is set via /proc/irq | |
144 | */ | |
145 | int irq_select_affinity_usr(unsigned int irq) | |
146 | { | |
147 | struct irq_desc *desc = irq_to_desc(irq); | |
148 | unsigned long flags; | |
149 | int ret; | |
150 | ||
151 | spin_lock_irqsave(&desc->lock, flags); | |
152 | ret = do_irq_select_affinity(irq, desc); | |
153 | spin_unlock_irqrestore(&desc->lock, flags); | |
154 | ||
155 | return ret; | |
156 | } | |
157 | ||
158 | #else | |
f131e243 | 159 | static inline int do_irq_select_affinity(int irq, struct irq_desc *desc) |
f6d87f4b TG |
160 | { |
161 | return 0; | |
162 | } | |
1da177e4 LT |
163 | #endif |
164 | ||
165 | /** | |
166 | * disable_irq_nosync - disable an irq without waiting | |
167 | * @irq: Interrupt to disable | |
168 | * | |
169 | * Disable the selected interrupt line. Disables and Enables are | |
170 | * nested. | |
171 | * Unlike disable_irq(), this function does not ensure existing | |
172 | * instances of the IRQ handler have completed before returning. | |
173 | * | |
174 | * This function may be called from IRQ context. | |
175 | */ | |
176 | void disable_irq_nosync(unsigned int irq) | |
177 | { | |
d3c60047 | 178 | struct irq_desc *desc = irq_to_desc(irq); |
1da177e4 LT |
179 | unsigned long flags; |
180 | ||
7d94f7ca | 181 | if (!desc) |
c2b5a251 MW |
182 | return; |
183 | ||
1da177e4 LT |
184 | spin_lock_irqsave(&desc->lock, flags); |
185 | if (!desc->depth++) { | |
186 | desc->status |= IRQ_DISABLED; | |
d1bef4ed | 187 | desc->chip->disable(irq); |
1da177e4 LT |
188 | } |
189 | spin_unlock_irqrestore(&desc->lock, flags); | |
190 | } | |
1da177e4 LT |
191 | EXPORT_SYMBOL(disable_irq_nosync); |
192 | ||
193 | /** | |
194 | * disable_irq - disable an irq and wait for completion | |
195 | * @irq: Interrupt to disable | |
196 | * | |
197 | * Disable the selected interrupt line. Enables and Disables are | |
198 | * nested. | |
199 | * This function waits for any pending IRQ handlers for this interrupt | |
200 | * to complete before returning. If you use this function while | |
201 | * holding a resource the IRQ handler may need you will deadlock. | |
202 | * | |
203 | * This function may be called - with care - from IRQ context. | |
204 | */ | |
205 | void disable_irq(unsigned int irq) | |
206 | { | |
d3c60047 | 207 | struct irq_desc *desc = irq_to_desc(irq); |
1da177e4 | 208 | |
7d94f7ca | 209 | if (!desc) |
c2b5a251 MW |
210 | return; |
211 | ||
1da177e4 LT |
212 | disable_irq_nosync(irq); |
213 | if (desc->action) | |
214 | synchronize_irq(irq); | |
215 | } | |
1da177e4 LT |
216 | EXPORT_SYMBOL(disable_irq); |
217 | ||
1adb0850 TG |
218 | static void __enable_irq(struct irq_desc *desc, unsigned int irq) |
219 | { | |
220 | switch (desc->depth) { | |
221 | case 0: | |
b8c512f6 | 222 | WARN(1, KERN_WARNING "Unbalanced enable for IRQ %d\n", irq); |
1adb0850 TG |
223 | break; |
224 | case 1: { | |
225 | unsigned int status = desc->status & ~IRQ_DISABLED; | |
226 | ||
227 | /* Prevent probing on this irq: */ | |
228 | desc->status = status | IRQ_NOPROBE; | |
229 | check_irq_resend(desc, irq); | |
230 | /* fall-through */ | |
231 | } | |
232 | default: | |
233 | desc->depth--; | |
234 | } | |
235 | } | |
236 | ||
1da177e4 LT |
237 | /** |
238 | * enable_irq - enable handling of an irq | |
239 | * @irq: Interrupt to enable | |
240 | * | |
241 | * Undoes the effect of one call to disable_irq(). If this | |
242 | * matches the last disable, processing of interrupts on this | |
243 | * IRQ line is re-enabled. | |
244 | * | |
245 | * This function may be called from IRQ context. | |
246 | */ | |
247 | void enable_irq(unsigned int irq) | |
248 | { | |
d3c60047 | 249 | struct irq_desc *desc = irq_to_desc(irq); |
1da177e4 LT |
250 | unsigned long flags; |
251 | ||
7d94f7ca | 252 | if (!desc) |
c2b5a251 MW |
253 | return; |
254 | ||
1da177e4 | 255 | spin_lock_irqsave(&desc->lock, flags); |
1adb0850 | 256 | __enable_irq(desc, irq); |
1da177e4 LT |
257 | spin_unlock_irqrestore(&desc->lock, flags); |
258 | } | |
1da177e4 LT |
259 | EXPORT_SYMBOL(enable_irq); |
260 | ||
0c5d1eb7 | 261 | static int set_irq_wake_real(unsigned int irq, unsigned int on) |
2db87321 | 262 | { |
08678b08 | 263 | struct irq_desc *desc = irq_to_desc(irq); |
2db87321 UKK |
264 | int ret = -ENXIO; |
265 | ||
266 | if (desc->chip->set_wake) | |
267 | ret = desc->chip->set_wake(irq, on); | |
268 | ||
269 | return ret; | |
270 | } | |
271 | ||
ba9a2331 TG |
272 | /** |
273 | * set_irq_wake - control irq power management wakeup | |
274 | * @irq: interrupt to control | |
275 | * @on: enable/disable power management wakeup | |
276 | * | |
15a647eb DB |
277 | * Enable/disable power management wakeup mode, which is |
278 | * disabled by default. Enables and disables must match, | |
279 | * just as they match for non-wakeup mode support. | |
280 | * | |
281 | * Wakeup mode lets this IRQ wake the system from sleep | |
282 | * states like "suspend to RAM". | |
ba9a2331 TG |
283 | */ |
284 | int set_irq_wake(unsigned int irq, unsigned int on) | |
285 | { | |
08678b08 | 286 | struct irq_desc *desc = irq_to_desc(irq); |
ba9a2331 | 287 | unsigned long flags; |
2db87321 | 288 | int ret = 0; |
ba9a2331 | 289 | |
15a647eb DB |
290 | /* wakeup-capable irqs can be shared between drivers that |
291 | * don't need to have the same sleep mode behaviors. | |
292 | */ | |
ba9a2331 | 293 | spin_lock_irqsave(&desc->lock, flags); |
15a647eb | 294 | if (on) { |
2db87321 UKK |
295 | if (desc->wake_depth++ == 0) { |
296 | ret = set_irq_wake_real(irq, on); | |
297 | if (ret) | |
298 | desc->wake_depth = 0; | |
299 | else | |
300 | desc->status |= IRQ_WAKEUP; | |
301 | } | |
15a647eb DB |
302 | } else { |
303 | if (desc->wake_depth == 0) { | |
7a2c4770 | 304 | WARN(1, "Unbalanced IRQ %d wake disable\n", irq); |
2db87321 UKK |
305 | } else if (--desc->wake_depth == 0) { |
306 | ret = set_irq_wake_real(irq, on); | |
307 | if (ret) | |
308 | desc->wake_depth = 1; | |
309 | else | |
310 | desc->status &= ~IRQ_WAKEUP; | |
311 | } | |
15a647eb | 312 | } |
2db87321 | 313 | |
ba9a2331 TG |
314 | spin_unlock_irqrestore(&desc->lock, flags); |
315 | return ret; | |
316 | } | |
317 | EXPORT_SYMBOL(set_irq_wake); | |
318 | ||
1da177e4 LT |
319 | /* |
320 | * Internal function that tells the architecture code whether a | |
321 | * particular irq has been exclusively allocated or is available | |
322 | * for driver use. | |
323 | */ | |
324 | int can_request_irq(unsigned int irq, unsigned long irqflags) | |
325 | { | |
d3c60047 | 326 | struct irq_desc *desc = irq_to_desc(irq); |
1da177e4 LT |
327 | struct irqaction *action; |
328 | ||
7d94f7ca YL |
329 | if (!desc) |
330 | return 0; | |
331 | ||
332 | if (desc->status & IRQ_NOREQUEST) | |
1da177e4 LT |
333 | return 0; |
334 | ||
08678b08 | 335 | action = desc->action; |
1da177e4 | 336 | if (action) |
3cca53b0 | 337 | if (irqflags & action->flags & IRQF_SHARED) |
1da177e4 LT |
338 | action = NULL; |
339 | ||
340 | return !action; | |
341 | } | |
342 | ||
6a6de9ef TG |
343 | void compat_irq_chip_set_default_handler(struct irq_desc *desc) |
344 | { | |
345 | /* | |
346 | * If the architecture still has not overriden | |
347 | * the flow handler then zap the default. This | |
348 | * should catch incorrect flow-type setting. | |
349 | */ | |
350 | if (desc->handle_irq == &handle_bad_irq) | |
351 | desc->handle_irq = NULL; | |
352 | } | |
353 | ||
0c5d1eb7 | 354 | int __irq_set_trigger(struct irq_desc *desc, unsigned int irq, |
82736f4d UKK |
355 | unsigned long flags) |
356 | { | |
357 | int ret; | |
0c5d1eb7 | 358 | struct irq_chip *chip = desc->chip; |
82736f4d UKK |
359 | |
360 | if (!chip || !chip->set_type) { | |
361 | /* | |
362 | * IRQF_TRIGGER_* but the PIC does not support multiple | |
363 | * flow-types? | |
364 | */ | |
3ff68a6a | 365 | pr_debug("No set_type function for IRQ %d (%s)\n", irq, |
82736f4d UKK |
366 | chip ? (chip->name ? : "unknown") : "unknown"); |
367 | return 0; | |
368 | } | |
369 | ||
f2b662da DB |
370 | /* caller masked out all except trigger mode flags */ |
371 | ret = chip->set_type(irq, flags); | |
82736f4d UKK |
372 | |
373 | if (ret) | |
c69ad71b | 374 | pr_err("setting trigger mode %d for irq %u failed (%pF)\n", |
f2b662da | 375 | (int)flags, irq, chip->set_type); |
0c5d1eb7 | 376 | else { |
f2b662da DB |
377 | if (flags & (IRQ_TYPE_LEVEL_LOW | IRQ_TYPE_LEVEL_HIGH)) |
378 | flags |= IRQ_LEVEL; | |
0c5d1eb7 | 379 | /* note that IRQF_TRIGGER_MASK == IRQ_TYPE_SENSE_MASK */ |
f2b662da DB |
380 | desc->status &= ~(IRQ_LEVEL | IRQ_TYPE_SENSE_MASK); |
381 | desc->status |= flags; | |
0c5d1eb7 | 382 | } |
82736f4d UKK |
383 | |
384 | return ret; | |
385 | } | |
386 | ||
1da177e4 LT |
387 | /* |
388 | * Internal function to register an irqaction - typically used to | |
389 | * allocate special interrupts that are part of the architecture. | |
390 | */ | |
d3c60047 | 391 | static int |
327ec569 | 392 | __setup_irq(unsigned int irq, struct irq_desc *desc, struct irqaction *new) |
1da177e4 | 393 | { |
f17c7545 | 394 | struct irqaction *old, **old_ptr; |
8b126b77 | 395 | const char *old_name = NULL; |
1da177e4 LT |
396 | unsigned long flags; |
397 | int shared = 0; | |
82736f4d | 398 | int ret; |
1da177e4 | 399 | |
7d94f7ca | 400 | if (!desc) |
c2b5a251 MW |
401 | return -EINVAL; |
402 | ||
f1c2662c | 403 | if (desc->chip == &no_irq_chip) |
1da177e4 LT |
404 | return -ENOSYS; |
405 | /* | |
406 | * Some drivers like serial.c use request_irq() heavily, | |
407 | * so we have to be careful not to interfere with a | |
408 | * running system. | |
409 | */ | |
3cca53b0 | 410 | if (new->flags & IRQF_SAMPLE_RANDOM) { |
1da177e4 LT |
411 | /* |
412 | * This function might sleep, we want to call it first, | |
413 | * outside of the atomic block. | |
414 | * Yes, this might clear the entropy pool if the wrong | |
415 | * driver is attempted to be loaded, without actually | |
416 | * installing a new handler, but is this really a problem, | |
417 | * only the sysadmin is able to do this. | |
418 | */ | |
419 | rand_initialize_irq(irq); | |
420 | } | |
421 | ||
422 | /* | |
423 | * The following block of code has to be executed atomically | |
424 | */ | |
06fcb0c6 | 425 | spin_lock_irqsave(&desc->lock, flags); |
f17c7545 IM |
426 | old_ptr = &desc->action; |
427 | old = *old_ptr; | |
06fcb0c6 | 428 | if (old) { |
e76de9f8 TG |
429 | /* |
430 | * Can't share interrupts unless both agree to and are | |
431 | * the same type (level, edge, polarity). So both flag | |
3cca53b0 | 432 | * fields must have IRQF_SHARED set and the bits which |
e76de9f8 TG |
433 | * set the trigger type must match. |
434 | */ | |
3cca53b0 | 435 | if (!((old->flags & new->flags) & IRQF_SHARED) || |
8b126b77 AM |
436 | ((old->flags ^ new->flags) & IRQF_TRIGGER_MASK)) { |
437 | old_name = old->name; | |
f5163427 | 438 | goto mismatch; |
8b126b77 | 439 | } |
f5163427 | 440 | |
284c6680 | 441 | #if defined(CONFIG_IRQ_PER_CPU) |
f5163427 | 442 | /* All handlers must agree on per-cpuness */ |
3cca53b0 TG |
443 | if ((old->flags & IRQF_PERCPU) != |
444 | (new->flags & IRQF_PERCPU)) | |
f5163427 DS |
445 | goto mismatch; |
446 | #endif | |
1da177e4 LT |
447 | |
448 | /* add new interrupt at end of irq queue */ | |
449 | do { | |
f17c7545 IM |
450 | old_ptr = &old->next; |
451 | old = *old_ptr; | |
1da177e4 LT |
452 | } while (old); |
453 | shared = 1; | |
454 | } | |
455 | ||
1da177e4 | 456 | if (!shared) { |
6a6de9ef | 457 | irq_chip_set_defaults(desc->chip); |
e76de9f8 TG |
458 | |
459 | /* Setup the type (level, edge polarity) if configured: */ | |
3cca53b0 | 460 | if (new->flags & IRQF_TRIGGER_MASK) { |
f2b662da DB |
461 | ret = __irq_set_trigger(desc, irq, |
462 | new->flags & IRQF_TRIGGER_MASK); | |
82736f4d UKK |
463 | |
464 | if (ret) { | |
465 | spin_unlock_irqrestore(&desc->lock, flags); | |
466 | return ret; | |
467 | } | |
e76de9f8 TG |
468 | } else |
469 | compat_irq_chip_set_default_handler(desc); | |
82736f4d UKK |
470 | #if defined(CONFIG_IRQ_PER_CPU) |
471 | if (new->flags & IRQF_PERCPU) | |
472 | desc->status |= IRQ_PER_CPU; | |
473 | #endif | |
6a6de9ef | 474 | |
94d39e1f | 475 | desc->status &= ~(IRQ_AUTODETECT | IRQ_WAITING | |
1adb0850 | 476 | IRQ_INPROGRESS | IRQ_SPURIOUS_DISABLED); |
94d39e1f TG |
477 | |
478 | if (!(desc->status & IRQ_NOAUTOEN)) { | |
479 | desc->depth = 0; | |
480 | desc->status &= ~IRQ_DISABLED; | |
7e6e178a | 481 | desc->chip->startup(irq); |
e76de9f8 TG |
482 | } else |
483 | /* Undo nested disables: */ | |
484 | desc->depth = 1; | |
18404756 | 485 | |
612e3684 TG |
486 | /* Exclude IRQ from balancing if requested */ |
487 | if (new->flags & IRQF_NOBALANCING) | |
488 | desc->status |= IRQ_NO_BALANCING; | |
489 | ||
18404756 | 490 | /* Set default affinity mask once everything is setup */ |
f6d87f4b | 491 | do_irq_select_affinity(irq, desc); |
0c5d1eb7 DB |
492 | |
493 | } else if ((new->flags & IRQF_TRIGGER_MASK) | |
494 | && (new->flags & IRQF_TRIGGER_MASK) | |
495 | != (desc->status & IRQ_TYPE_SENSE_MASK)) { | |
496 | /* hope the handler works with the actual trigger mode... */ | |
497 | pr_warning("IRQ %d uses trigger mode %d; requested %d\n", | |
498 | irq, (int)(desc->status & IRQ_TYPE_SENSE_MASK), | |
499 | (int)(new->flags & IRQF_TRIGGER_MASK)); | |
1da177e4 | 500 | } |
82736f4d | 501 | |
f17c7545 | 502 | *old_ptr = new; |
82736f4d | 503 | |
8528b0f1 LT |
504 | /* Reset broken irq detection when installing new handler */ |
505 | desc->irq_count = 0; | |
506 | desc->irqs_unhandled = 0; | |
1adb0850 TG |
507 | |
508 | /* | |
509 | * Check whether we disabled the irq via the spurious handler | |
510 | * before. Reenable it and give it another chance. | |
511 | */ | |
512 | if (shared && (desc->status & IRQ_SPURIOUS_DISABLED)) { | |
513 | desc->status &= ~IRQ_SPURIOUS_DISABLED; | |
514 | __enable_irq(desc, irq); | |
515 | } | |
516 | ||
06fcb0c6 | 517 | spin_unlock_irqrestore(&desc->lock, flags); |
1da177e4 LT |
518 | |
519 | new->irq = irq; | |
2c6927a3 | 520 | register_irq_proc(irq, desc); |
1da177e4 LT |
521 | new->dir = NULL; |
522 | register_handler_proc(irq, new); | |
523 | ||
524 | return 0; | |
f5163427 DS |
525 | |
526 | mismatch: | |
3f050447 | 527 | #ifdef CONFIG_DEBUG_SHIRQ |
3cca53b0 | 528 | if (!(new->flags & IRQF_PROBE_SHARED)) { |
e8c4b9d0 | 529 | printk(KERN_ERR "IRQ handler type mismatch for IRQ %d\n", irq); |
8b126b77 AM |
530 | if (old_name) |
531 | printk(KERN_ERR "current handler: %s\n", old_name); | |
13e87ec6 AM |
532 | dump_stack(); |
533 | } | |
3f050447 | 534 | #endif |
8b126b77 | 535 | spin_unlock_irqrestore(&desc->lock, flags); |
f5163427 | 536 | return -EBUSY; |
1da177e4 LT |
537 | } |
538 | ||
d3c60047 TG |
539 | /** |
540 | * setup_irq - setup an interrupt | |
541 | * @irq: Interrupt line to setup | |
542 | * @act: irqaction for the interrupt | |
543 | * | |
544 | * Used to statically setup interrupts in the early boot process. | |
545 | */ | |
546 | int setup_irq(unsigned int irq, struct irqaction *act) | |
547 | { | |
548 | struct irq_desc *desc = irq_to_desc(irq); | |
549 | ||
550 | return __setup_irq(irq, desc, act); | |
551 | } | |
552 | ||
cbf94f06 MD |
553 | /* |
554 | * Internal function to unregister an irqaction - used to free | |
555 | * regular and special interrupts that are part of the architecture. | |
1da177e4 | 556 | */ |
cbf94f06 | 557 | static struct irqaction *__free_irq(unsigned int irq, void *dev_id) |
1da177e4 | 558 | { |
d3c60047 | 559 | struct irq_desc *desc = irq_to_desc(irq); |
f17c7545 | 560 | struct irqaction *action, **action_ptr; |
1da177e4 LT |
561 | unsigned long flags; |
562 | ||
ae88a23b | 563 | WARN(in_interrupt(), "Trying to free IRQ %d from IRQ context!\n", irq); |
7d94f7ca | 564 | |
7d94f7ca | 565 | if (!desc) |
f21cfb25 | 566 | return NULL; |
1da177e4 | 567 | |
06fcb0c6 | 568 | spin_lock_irqsave(&desc->lock, flags); |
ae88a23b IM |
569 | |
570 | /* | |
571 | * There can be multiple actions per IRQ descriptor, find the right | |
572 | * one based on the dev_id: | |
573 | */ | |
f17c7545 | 574 | action_ptr = &desc->action; |
1da177e4 | 575 | for (;;) { |
f17c7545 | 576 | action = *action_ptr; |
1da177e4 | 577 | |
ae88a23b IM |
578 | if (!action) { |
579 | WARN(1, "Trying to free already-free IRQ %d\n", irq); | |
580 | spin_unlock_irqrestore(&desc->lock, flags); | |
1da177e4 | 581 | |
f21cfb25 | 582 | return NULL; |
ae88a23b | 583 | } |
1da177e4 | 584 | |
8316e381 IM |
585 | if (action->dev_id == dev_id) |
586 | break; | |
f17c7545 | 587 | action_ptr = &action->next; |
ae88a23b IM |
588 | } |
589 | ||
590 | /* Found it - now remove it from the list of entries: */ | |
f17c7545 | 591 | *action_ptr = action->next; |
ae88a23b IM |
592 | |
593 | /* Currently used only by UML, might disappear one day: */ | |
b77d6adc | 594 | #ifdef CONFIG_IRQ_RELEASE_METHOD |
ae88a23b IM |
595 | if (desc->chip->release) |
596 | desc->chip->release(irq, dev_id); | |
b77d6adc | 597 | #endif |
dbce706e | 598 | |
ae88a23b IM |
599 | /* If this was the last handler, shut down the IRQ line: */ |
600 | if (!desc->action) { | |
601 | desc->status |= IRQ_DISABLED; | |
602 | if (desc->chip->shutdown) | |
603 | desc->chip->shutdown(irq); | |
604 | else | |
605 | desc->chip->disable(irq); | |
606 | } | |
607 | spin_unlock_irqrestore(&desc->lock, flags); | |
608 | ||
609 | unregister_handler_proc(irq, action); | |
610 | ||
611 | /* Make sure it's not being used on another CPU: */ | |
612 | synchronize_irq(irq); | |
1da177e4 | 613 | |
70edcd77 | 614 | #ifdef CONFIG_DEBUG_SHIRQ |
ae88a23b IM |
615 | /* |
616 | * It's a shared IRQ -- the driver ought to be prepared for an IRQ | |
617 | * event to happen even now it's being freed, so let's make sure that | |
618 | * is so by doing an extra call to the handler .... | |
619 | * | |
620 | * ( We do this after actually deregistering it, to make sure that a | |
621 | * 'real' IRQ doesn't run in * parallel with our fake. ) | |
622 | */ | |
623 | if (action->flags & IRQF_SHARED) { | |
624 | local_irq_save(flags); | |
625 | action->handler(irq, dev_id); | |
626 | local_irq_restore(flags); | |
1da177e4 | 627 | } |
ae88a23b | 628 | #endif |
f21cfb25 MD |
629 | return action; |
630 | } | |
631 | ||
cbf94f06 MD |
632 | /** |
633 | * remove_irq - free an interrupt | |
634 | * @irq: Interrupt line to free | |
635 | * @act: irqaction for the interrupt | |
636 | * | |
637 | * Used to remove interrupts statically setup by the early boot process. | |
638 | */ | |
639 | void remove_irq(unsigned int irq, struct irqaction *act) | |
640 | { | |
641 | __free_irq(irq, act->dev_id); | |
642 | } | |
643 | ||
f21cfb25 MD |
644 | /** |
645 | * free_irq - free an interrupt allocated with request_irq | |
646 | * @irq: Interrupt line to free | |
647 | * @dev_id: Device identity to free | |
648 | * | |
649 | * Remove an interrupt handler. The handler is removed and if the | |
650 | * interrupt line is no longer in use by any driver it is disabled. | |
651 | * On a shared IRQ the caller must ensure the interrupt is disabled | |
652 | * on the card it drives before calling this function. The function | |
653 | * does not return until any executing interrupts for this IRQ | |
654 | * have completed. | |
655 | * | |
656 | * This function must not be called from interrupt context. | |
657 | */ | |
658 | void free_irq(unsigned int irq, void *dev_id) | |
659 | { | |
cbf94f06 | 660 | kfree(__free_irq(irq, dev_id)); |
1da177e4 | 661 | } |
1da177e4 LT |
662 | EXPORT_SYMBOL(free_irq); |
663 | ||
664 | /** | |
665 | * request_irq - allocate an interrupt line | |
666 | * @irq: Interrupt line to allocate | |
667 | * @handler: Function to be called when the IRQ occurs | |
668 | * @irqflags: Interrupt type flags | |
669 | * @devname: An ascii name for the claiming device | |
670 | * @dev_id: A cookie passed back to the handler function | |
671 | * | |
672 | * This call allocates interrupt resources and enables the | |
673 | * interrupt line and IRQ handling. From the point this | |
674 | * call is made your handler function may be invoked. Since | |
675 | * your handler function must clear any interrupt the board | |
676 | * raises, you must take care both to initialise your hardware | |
677 | * and to set up the interrupt handler in the right order. | |
678 | * | |
679 | * Dev_id must be globally unique. Normally the address of the | |
680 | * device data structure is used as the cookie. Since the handler | |
681 | * receives this value it makes sense to use it. | |
682 | * | |
683 | * If your interrupt is shared you must pass a non NULL dev_id | |
684 | * as this is required when freeing the interrupt. | |
685 | * | |
686 | * Flags: | |
687 | * | |
3cca53b0 TG |
688 | * IRQF_SHARED Interrupt is shared |
689 | * IRQF_DISABLED Disable local interrupts while processing | |
690 | * IRQF_SAMPLE_RANDOM The interrupt can be used for entropy | |
0c5d1eb7 | 691 | * IRQF_TRIGGER_* Specify active edge(s) or level |
1da177e4 LT |
692 | * |
693 | */ | |
da482792 | 694 | int request_irq(unsigned int irq, irq_handler_t handler, |
06fcb0c6 | 695 | unsigned long irqflags, const char *devname, void *dev_id) |
1da177e4 | 696 | { |
06fcb0c6 | 697 | struct irqaction *action; |
08678b08 | 698 | struct irq_desc *desc; |
d3c60047 | 699 | int retval; |
1da177e4 | 700 | |
470c6623 DB |
701 | /* |
702 | * handle_IRQ_event() always ignores IRQF_DISABLED except for | |
703 | * the _first_ irqaction (sigh). That can cause oopsing, but | |
704 | * the behavior is classified as "will not fix" so we need to | |
705 | * start nudging drivers away from using that idiom. | |
706 | */ | |
327ec569 IM |
707 | if ((irqflags & (IRQF_SHARED|IRQF_DISABLED)) == |
708 | (IRQF_SHARED|IRQF_DISABLED)) { | |
709 | pr_warning( | |
710 | "IRQ %d/%s: IRQF_DISABLED is not guaranteed on shared IRQs\n", | |
711 | irq, devname); | |
712 | } | |
470c6623 | 713 | |
fbb9ce95 IM |
714 | #ifdef CONFIG_LOCKDEP |
715 | /* | |
716 | * Lockdep wants atomic interrupt handlers: | |
717 | */ | |
38515e90 | 718 | irqflags |= IRQF_DISABLED; |
fbb9ce95 | 719 | #endif |
1da177e4 LT |
720 | /* |
721 | * Sanity-check: shared interrupts must pass in a real dev-ID, | |
722 | * otherwise we'll have trouble later trying to figure out | |
723 | * which interrupt is which (messes up the interrupt freeing | |
724 | * logic etc). | |
725 | */ | |
3cca53b0 | 726 | if ((irqflags & IRQF_SHARED) && !dev_id) |
1da177e4 | 727 | return -EINVAL; |
7d94f7ca | 728 | |
cb5bc832 | 729 | desc = irq_to_desc(irq); |
7d94f7ca | 730 | if (!desc) |
1da177e4 | 731 | return -EINVAL; |
7d94f7ca | 732 | |
08678b08 | 733 | if (desc->status & IRQ_NOREQUEST) |
6550c775 | 734 | return -EINVAL; |
1da177e4 LT |
735 | if (!handler) |
736 | return -EINVAL; | |
737 | ||
0e43785c | 738 | action = kmalloc(sizeof(struct irqaction), GFP_KERNEL); |
1da177e4 LT |
739 | if (!action) |
740 | return -ENOMEM; | |
741 | ||
742 | action->handler = handler; | |
743 | action->flags = irqflags; | |
744 | cpus_clear(action->mask); | |
745 | action->name = devname; | |
746 | action->next = NULL; | |
747 | action->dev_id = dev_id; | |
748 | ||
d3c60047 | 749 | retval = __setup_irq(irq, desc, action); |
377bf1e4 AV |
750 | if (retval) |
751 | kfree(action); | |
752 | ||
a304e1b8 DW |
753 | #ifdef CONFIG_DEBUG_SHIRQ |
754 | if (irqflags & IRQF_SHARED) { | |
755 | /* | |
756 | * It's a shared IRQ -- the driver ought to be prepared for it | |
757 | * to happen immediately, so let's make sure.... | |
377bf1e4 AV |
758 | * We disable the irq to make sure that a 'real' IRQ doesn't |
759 | * run in parallel with our fake. | |
a304e1b8 | 760 | */ |
59845b1f | 761 | unsigned long flags; |
a304e1b8 | 762 | |
377bf1e4 | 763 | disable_irq(irq); |
59845b1f | 764 | local_irq_save(flags); |
377bf1e4 | 765 | |
59845b1f | 766 | handler(irq, dev_id); |
377bf1e4 | 767 | |
59845b1f | 768 | local_irq_restore(flags); |
377bf1e4 | 769 | enable_irq(irq); |
a304e1b8 DW |
770 | } |
771 | #endif | |
1da177e4 LT |
772 | return retval; |
773 | } | |
1da177e4 | 774 | EXPORT_SYMBOL(request_irq); |