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> | |
3aa551c9 | 11 | #include <linux/kthread.h> |
1da177e4 LT |
12 | #include <linux/module.h> |
13 | #include <linux/random.h> | |
14 | #include <linux/interrupt.h> | |
1aeb272c | 15 | #include <linux/slab.h> |
3aa551c9 | 16 | #include <linux/sched.h> |
1da177e4 LT |
17 | |
18 | #include "internals.h" | |
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 | { | |
cb5bc832 | 32 | struct irq_desc *desc = irq_to_desc(irq); |
a98ce5c6 | 33 | unsigned int status; |
1da177e4 | 34 | |
7d94f7ca | 35 | if (!desc) |
c2b5a251 MW |
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); | |
3aa551c9 TG |
55 | |
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)); | |
1da177e4 | 61 | } |
1da177e4 LT |
62 | EXPORT_SYMBOL(synchronize_irq); |
63 | ||
3aa551c9 TG |
64 | #ifdef CONFIG_SMP |
65 | cpumask_var_t irq_default_affinity; | |
66 | ||
771ee3b0 TG |
67 | /** |
68 | * irq_can_set_affinity - Check if the affinity of a given irq can be set | |
69 | * @irq: Interrupt to check | |
70 | * | |
71 | */ | |
72 | int irq_can_set_affinity(unsigned int irq) | |
73 | { | |
08678b08 | 74 | struct irq_desc *desc = irq_to_desc(irq); |
771ee3b0 TG |
75 | |
76 | if (CHECK_IRQ_PER_CPU(desc->status) || !desc->chip || | |
77 | !desc->chip->set_affinity) | |
78 | return 0; | |
79 | ||
80 | return 1; | |
81 | } | |
82 | ||
591d2fb0 TG |
83 | /** |
84 | * irq_set_thread_affinity - Notify irq threads to adjust affinity | |
85 | * @desc: irq descriptor which has affitnity changed | |
86 | * | |
87 | * We just set IRQTF_AFFINITY and delegate the affinity setting | |
88 | * to the interrupt thread itself. We can not call | |
89 | * set_cpus_allowed_ptr() here as we hold desc->lock and this | |
90 | * code can be called from hard interrupt context. | |
91 | */ | |
92 | void irq_set_thread_affinity(struct irq_desc *desc) | |
3aa551c9 TG |
93 | { |
94 | struct irqaction *action = desc->action; | |
95 | ||
96 | while (action) { | |
97 | if (action->thread) | |
591d2fb0 | 98 | set_bit(IRQTF_AFFINITY, &action->thread_flags); |
3aa551c9 TG |
99 | action = action->next; |
100 | } | |
101 | } | |
102 | ||
771ee3b0 TG |
103 | /** |
104 | * irq_set_affinity - Set the irq affinity of a given irq | |
105 | * @irq: Interrupt to set affinity | |
106 | * @cpumask: cpumask | |
107 | * | |
108 | */ | |
0de26520 | 109 | int irq_set_affinity(unsigned int irq, const struct cpumask *cpumask) |
771ee3b0 | 110 | { |
08678b08 | 111 | struct irq_desc *desc = irq_to_desc(irq); |
f6d87f4b | 112 | unsigned long flags; |
771ee3b0 TG |
113 | |
114 | if (!desc->chip->set_affinity) | |
115 | return -EINVAL; | |
116 | ||
f6d87f4b TG |
117 | spin_lock_irqsave(&desc->lock, flags); |
118 | ||
771ee3b0 | 119 | #ifdef CONFIG_GENERIC_PENDING_IRQ |
57b150cc YL |
120 | if (desc->status & IRQ_MOVE_PCNTXT) { |
121 | if (!desc->chip->set_affinity(irq, cpumask)) { | |
122 | cpumask_copy(desc->affinity, cpumask); | |
591d2fb0 | 123 | irq_set_thread_affinity(desc); |
57b150cc YL |
124 | } |
125 | } | |
6ec3cfec | 126 | else { |
f6d87f4b | 127 | desc->status |= IRQ_MOVE_PENDING; |
7f7ace0c | 128 | cpumask_copy(desc->pending_mask, cpumask); |
f6d87f4b | 129 | } |
771ee3b0 | 130 | #else |
57b150cc YL |
131 | if (!desc->chip->set_affinity(irq, cpumask)) { |
132 | cpumask_copy(desc->affinity, cpumask); | |
591d2fb0 | 133 | irq_set_thread_affinity(desc); |
57b150cc | 134 | } |
771ee3b0 | 135 | #endif |
f6d87f4b TG |
136 | desc->status |= IRQ_AFFINITY_SET; |
137 | spin_unlock_irqrestore(&desc->lock, flags); | |
771ee3b0 TG |
138 | return 0; |
139 | } | |
140 | ||
18404756 MK |
141 | #ifndef CONFIG_AUTO_IRQ_AFFINITY |
142 | /* | |
143 | * Generic version of the affinity autoselector. | |
144 | */ | |
548c8933 | 145 | static int setup_affinity(unsigned int irq, struct irq_desc *desc) |
18404756 | 146 | { |
18404756 MK |
147 | if (!irq_can_set_affinity(irq)) |
148 | return 0; | |
149 | ||
f6d87f4b TG |
150 | /* |
151 | * Preserve an userspace affinity setup, but make sure that | |
152 | * one of the targets is online. | |
153 | */ | |
612e3684 | 154 | if (desc->status & (IRQ_AFFINITY_SET | IRQ_NO_BALANCING)) { |
7f7ace0c | 155 | if (cpumask_any_and(desc->affinity, cpu_online_mask) |
0de26520 RR |
156 | < nr_cpu_ids) |
157 | goto set_affinity; | |
f6d87f4b TG |
158 | else |
159 | desc->status &= ~IRQ_AFFINITY_SET; | |
160 | } | |
161 | ||
7f7ace0c | 162 | cpumask_and(desc->affinity, cpu_online_mask, irq_default_affinity); |
0de26520 | 163 | set_affinity: |
7f7ace0c | 164 | desc->chip->set_affinity(irq, desc->affinity); |
18404756 | 165 | |
18404756 MK |
166 | return 0; |
167 | } | |
f6d87f4b | 168 | #else |
548c8933 | 169 | static inline int setup_affinity(unsigned int irq, struct irq_desc *d) |
f6d87f4b TG |
170 | { |
171 | return irq_select_affinity(irq); | |
172 | } | |
18404756 MK |
173 | #endif |
174 | ||
f6d87f4b TG |
175 | /* |
176 | * Called when affinity is set via /proc/irq | |
177 | */ | |
178 | int irq_select_affinity_usr(unsigned int irq) | |
179 | { | |
180 | struct irq_desc *desc = irq_to_desc(irq); | |
181 | unsigned long flags; | |
182 | int ret; | |
183 | ||
184 | spin_lock_irqsave(&desc->lock, flags); | |
548c8933 | 185 | ret = setup_affinity(irq, desc); |
3aa551c9 | 186 | if (!ret) |
591d2fb0 | 187 | irq_set_thread_affinity(desc); |
f6d87f4b TG |
188 | spin_unlock_irqrestore(&desc->lock, flags); |
189 | ||
190 | return ret; | |
191 | } | |
192 | ||
193 | #else | |
548c8933 | 194 | static inline int setup_affinity(unsigned int irq, struct irq_desc *desc) |
f6d87f4b TG |
195 | { |
196 | return 0; | |
197 | } | |
1da177e4 LT |
198 | #endif |
199 | ||
0a0c5168 RW |
200 | void __disable_irq(struct irq_desc *desc, unsigned int irq, bool suspend) |
201 | { | |
202 | if (suspend) { | |
203 | if (!desc->action || (desc->action->flags & IRQF_TIMER)) | |
204 | return; | |
205 | desc->status |= IRQ_SUSPENDED; | |
206 | } | |
207 | ||
208 | if (!desc->depth++) { | |
209 | desc->status |= IRQ_DISABLED; | |
210 | desc->chip->disable(irq); | |
211 | } | |
212 | } | |
213 | ||
1da177e4 LT |
214 | /** |
215 | * disable_irq_nosync - disable an irq without waiting | |
216 | * @irq: Interrupt to disable | |
217 | * | |
218 | * Disable the selected interrupt line. Disables and Enables are | |
219 | * nested. | |
220 | * Unlike disable_irq(), this function does not ensure existing | |
221 | * instances of the IRQ handler have completed before returning. | |
222 | * | |
223 | * This function may be called from IRQ context. | |
224 | */ | |
225 | void disable_irq_nosync(unsigned int irq) | |
226 | { | |
d3c60047 | 227 | struct irq_desc *desc = irq_to_desc(irq); |
1da177e4 LT |
228 | unsigned long flags; |
229 | ||
7d94f7ca | 230 | if (!desc) |
c2b5a251 MW |
231 | return; |
232 | ||
1da177e4 | 233 | spin_lock_irqsave(&desc->lock, flags); |
0a0c5168 | 234 | __disable_irq(desc, irq, false); |
1da177e4 LT |
235 | spin_unlock_irqrestore(&desc->lock, flags); |
236 | } | |
1da177e4 LT |
237 | EXPORT_SYMBOL(disable_irq_nosync); |
238 | ||
239 | /** | |
240 | * disable_irq - disable an irq and wait for completion | |
241 | * @irq: Interrupt to disable | |
242 | * | |
243 | * Disable the selected interrupt line. Enables and Disables are | |
244 | * nested. | |
245 | * This function waits for any pending IRQ handlers for this interrupt | |
246 | * to complete before returning. If you use this function while | |
247 | * holding a resource the IRQ handler may need you will deadlock. | |
248 | * | |
249 | * This function may be called - with care - from IRQ context. | |
250 | */ | |
251 | void disable_irq(unsigned int irq) | |
252 | { | |
d3c60047 | 253 | struct irq_desc *desc = irq_to_desc(irq); |
1da177e4 | 254 | |
7d94f7ca | 255 | if (!desc) |
c2b5a251 MW |
256 | return; |
257 | ||
1da177e4 LT |
258 | disable_irq_nosync(irq); |
259 | if (desc->action) | |
260 | synchronize_irq(irq); | |
261 | } | |
1da177e4 LT |
262 | EXPORT_SYMBOL(disable_irq); |
263 | ||
0a0c5168 | 264 | void __enable_irq(struct irq_desc *desc, unsigned int irq, bool resume) |
1adb0850 | 265 | { |
0a0c5168 RW |
266 | if (resume) |
267 | desc->status &= ~IRQ_SUSPENDED; | |
268 | ||
1adb0850 TG |
269 | switch (desc->depth) { |
270 | case 0: | |
0a0c5168 | 271 | err_out: |
b8c512f6 | 272 | WARN(1, KERN_WARNING "Unbalanced enable for IRQ %d\n", irq); |
1adb0850 TG |
273 | break; |
274 | case 1: { | |
275 | unsigned int status = desc->status & ~IRQ_DISABLED; | |
276 | ||
0a0c5168 RW |
277 | if (desc->status & IRQ_SUSPENDED) |
278 | goto err_out; | |
1adb0850 TG |
279 | /* Prevent probing on this irq: */ |
280 | desc->status = status | IRQ_NOPROBE; | |
281 | check_irq_resend(desc, irq); | |
282 | /* fall-through */ | |
283 | } | |
284 | default: | |
285 | desc->depth--; | |
286 | } | |
287 | } | |
288 | ||
1da177e4 LT |
289 | /** |
290 | * enable_irq - enable handling of an irq | |
291 | * @irq: Interrupt to enable | |
292 | * | |
293 | * Undoes the effect of one call to disable_irq(). If this | |
294 | * matches the last disable, processing of interrupts on this | |
295 | * IRQ line is re-enabled. | |
296 | * | |
297 | * This function may be called from IRQ context. | |
298 | */ | |
299 | void enable_irq(unsigned int irq) | |
300 | { | |
d3c60047 | 301 | struct irq_desc *desc = irq_to_desc(irq); |
1da177e4 LT |
302 | unsigned long flags; |
303 | ||
7d94f7ca | 304 | if (!desc) |
c2b5a251 MW |
305 | return; |
306 | ||
1da177e4 | 307 | spin_lock_irqsave(&desc->lock, flags); |
0a0c5168 | 308 | __enable_irq(desc, irq, false); |
1da177e4 LT |
309 | spin_unlock_irqrestore(&desc->lock, flags); |
310 | } | |
1da177e4 LT |
311 | EXPORT_SYMBOL(enable_irq); |
312 | ||
0c5d1eb7 | 313 | static int set_irq_wake_real(unsigned int irq, unsigned int on) |
2db87321 | 314 | { |
08678b08 | 315 | struct irq_desc *desc = irq_to_desc(irq); |
2db87321 UKK |
316 | int ret = -ENXIO; |
317 | ||
318 | if (desc->chip->set_wake) | |
319 | ret = desc->chip->set_wake(irq, on); | |
320 | ||
321 | return ret; | |
322 | } | |
323 | ||
ba9a2331 TG |
324 | /** |
325 | * set_irq_wake - control irq power management wakeup | |
326 | * @irq: interrupt to control | |
327 | * @on: enable/disable power management wakeup | |
328 | * | |
15a647eb DB |
329 | * Enable/disable power management wakeup mode, which is |
330 | * disabled by default. Enables and disables must match, | |
331 | * just as they match for non-wakeup mode support. | |
332 | * | |
333 | * Wakeup mode lets this IRQ wake the system from sleep | |
334 | * states like "suspend to RAM". | |
ba9a2331 TG |
335 | */ |
336 | int set_irq_wake(unsigned int irq, unsigned int on) | |
337 | { | |
08678b08 | 338 | struct irq_desc *desc = irq_to_desc(irq); |
ba9a2331 | 339 | unsigned long flags; |
2db87321 | 340 | int ret = 0; |
ba9a2331 | 341 | |
15a647eb DB |
342 | /* wakeup-capable irqs can be shared between drivers that |
343 | * don't need to have the same sleep mode behaviors. | |
344 | */ | |
ba9a2331 | 345 | spin_lock_irqsave(&desc->lock, flags); |
15a647eb | 346 | if (on) { |
2db87321 UKK |
347 | if (desc->wake_depth++ == 0) { |
348 | ret = set_irq_wake_real(irq, on); | |
349 | if (ret) | |
350 | desc->wake_depth = 0; | |
351 | else | |
352 | desc->status |= IRQ_WAKEUP; | |
353 | } | |
15a647eb DB |
354 | } else { |
355 | if (desc->wake_depth == 0) { | |
7a2c4770 | 356 | WARN(1, "Unbalanced IRQ %d wake disable\n", irq); |
2db87321 UKK |
357 | } else if (--desc->wake_depth == 0) { |
358 | ret = set_irq_wake_real(irq, on); | |
359 | if (ret) | |
360 | desc->wake_depth = 1; | |
361 | else | |
362 | desc->status &= ~IRQ_WAKEUP; | |
363 | } | |
15a647eb | 364 | } |
2db87321 | 365 | |
ba9a2331 TG |
366 | spin_unlock_irqrestore(&desc->lock, flags); |
367 | return ret; | |
368 | } | |
369 | EXPORT_SYMBOL(set_irq_wake); | |
370 | ||
1da177e4 LT |
371 | /* |
372 | * Internal function that tells the architecture code whether a | |
373 | * particular irq has been exclusively allocated or is available | |
374 | * for driver use. | |
375 | */ | |
376 | int can_request_irq(unsigned int irq, unsigned long irqflags) | |
377 | { | |
d3c60047 | 378 | struct irq_desc *desc = irq_to_desc(irq); |
1da177e4 LT |
379 | struct irqaction *action; |
380 | ||
7d94f7ca YL |
381 | if (!desc) |
382 | return 0; | |
383 | ||
384 | if (desc->status & IRQ_NOREQUEST) | |
1da177e4 LT |
385 | return 0; |
386 | ||
08678b08 | 387 | action = desc->action; |
1da177e4 | 388 | if (action) |
3cca53b0 | 389 | if (irqflags & action->flags & IRQF_SHARED) |
1da177e4 LT |
390 | action = NULL; |
391 | ||
392 | return !action; | |
393 | } | |
394 | ||
6a6de9ef TG |
395 | void compat_irq_chip_set_default_handler(struct irq_desc *desc) |
396 | { | |
397 | /* | |
398 | * If the architecture still has not overriden | |
399 | * the flow handler then zap the default. This | |
400 | * should catch incorrect flow-type setting. | |
401 | */ | |
402 | if (desc->handle_irq == &handle_bad_irq) | |
403 | desc->handle_irq = NULL; | |
404 | } | |
405 | ||
0c5d1eb7 | 406 | int __irq_set_trigger(struct irq_desc *desc, unsigned int irq, |
82736f4d UKK |
407 | unsigned long flags) |
408 | { | |
409 | int ret; | |
0c5d1eb7 | 410 | struct irq_chip *chip = desc->chip; |
82736f4d UKK |
411 | |
412 | if (!chip || !chip->set_type) { | |
413 | /* | |
414 | * IRQF_TRIGGER_* but the PIC does not support multiple | |
415 | * flow-types? | |
416 | */ | |
3ff68a6a | 417 | pr_debug("No set_type function for IRQ %d (%s)\n", irq, |
82736f4d UKK |
418 | chip ? (chip->name ? : "unknown") : "unknown"); |
419 | return 0; | |
420 | } | |
421 | ||
f2b662da DB |
422 | /* caller masked out all except trigger mode flags */ |
423 | ret = chip->set_type(irq, flags); | |
82736f4d UKK |
424 | |
425 | if (ret) | |
c69ad71b | 426 | pr_err("setting trigger mode %d for irq %u failed (%pF)\n", |
f2b662da | 427 | (int)flags, irq, chip->set_type); |
0c5d1eb7 | 428 | else { |
f2b662da DB |
429 | if (flags & (IRQ_TYPE_LEVEL_LOW | IRQ_TYPE_LEVEL_HIGH)) |
430 | flags |= IRQ_LEVEL; | |
0c5d1eb7 | 431 | /* note that IRQF_TRIGGER_MASK == IRQ_TYPE_SENSE_MASK */ |
f2b662da DB |
432 | desc->status &= ~(IRQ_LEVEL | IRQ_TYPE_SENSE_MASK); |
433 | desc->status |= flags; | |
0c5d1eb7 | 434 | } |
82736f4d UKK |
435 | |
436 | return ret; | |
437 | } | |
438 | ||
3aa551c9 TG |
439 | static int irq_wait_for_interrupt(struct irqaction *action) |
440 | { | |
441 | while (!kthread_should_stop()) { | |
442 | set_current_state(TASK_INTERRUPTIBLE); | |
f48fe81e TG |
443 | |
444 | if (test_and_clear_bit(IRQTF_RUNTHREAD, | |
445 | &action->thread_flags)) { | |
3aa551c9 TG |
446 | __set_current_state(TASK_RUNNING); |
447 | return 0; | |
f48fe81e TG |
448 | } |
449 | schedule(); | |
3aa551c9 TG |
450 | } |
451 | return -1; | |
452 | } | |
453 | ||
61f38261 | 454 | #ifdef CONFIG_SMP |
591d2fb0 TG |
455 | /* |
456 | * Check whether we need to change the affinity of the interrupt thread. | |
457 | */ | |
458 | static void | |
459 | irq_thread_check_affinity(struct irq_desc *desc, struct irqaction *action) | |
460 | { | |
461 | cpumask_var_t mask; | |
462 | ||
463 | if (!test_and_clear_bit(IRQTF_AFFINITY, &action->thread_flags)) | |
464 | return; | |
465 | ||
466 | /* | |
467 | * In case we are out of memory we set IRQTF_AFFINITY again and | |
468 | * try again next time | |
469 | */ | |
470 | if (!alloc_cpumask_var(&mask, GFP_KERNEL)) { | |
471 | set_bit(IRQTF_AFFINITY, &action->thread_flags); | |
472 | return; | |
473 | } | |
474 | ||
475 | spin_lock_irq(&desc->lock); | |
476 | cpumask_copy(mask, desc->affinity); | |
477 | spin_unlock_irq(&desc->lock); | |
478 | ||
479 | set_cpus_allowed_ptr(current, mask); | |
480 | free_cpumask_var(mask); | |
481 | } | |
61f38261 BP |
482 | #else |
483 | static inline void | |
484 | irq_thread_check_affinity(struct irq_desc *desc, struct irqaction *action) { } | |
485 | #endif | |
591d2fb0 | 486 | |
3aa551c9 TG |
487 | /* |
488 | * Interrupt handler thread | |
489 | */ | |
490 | static int irq_thread(void *data) | |
491 | { | |
492 | struct sched_param param = { .sched_priority = MAX_USER_RT_PRIO/2, }; | |
493 | struct irqaction *action = data; | |
494 | struct irq_desc *desc = irq_to_desc(action->irq); | |
495 | int wake; | |
496 | ||
497 | sched_setscheduler(current, SCHED_FIFO, ¶m); | |
498 | current->irqaction = action; | |
499 | ||
500 | while (!irq_wait_for_interrupt(action)) { | |
501 | ||
591d2fb0 TG |
502 | irq_thread_check_affinity(desc, action); |
503 | ||
3aa551c9 TG |
504 | atomic_inc(&desc->threads_active); |
505 | ||
506 | spin_lock_irq(&desc->lock); | |
507 | if (unlikely(desc->status & IRQ_DISABLED)) { | |
508 | /* | |
509 | * CHECKME: We might need a dedicated | |
510 | * IRQ_THREAD_PENDING flag here, which | |
511 | * retriggers the thread in check_irq_resend() | |
512 | * but AFAICT IRQ_PENDING should be fine as it | |
513 | * retriggers the interrupt itself --- tglx | |
514 | */ | |
515 | desc->status |= IRQ_PENDING; | |
516 | spin_unlock_irq(&desc->lock); | |
517 | } else { | |
518 | spin_unlock_irq(&desc->lock); | |
519 | ||
520 | action->thread_fn(action->irq, action->dev_id); | |
521 | } | |
522 | ||
523 | wake = atomic_dec_and_test(&desc->threads_active); | |
524 | ||
525 | if (wake && waitqueue_active(&desc->wait_for_threads)) | |
526 | wake_up(&desc->wait_for_threads); | |
527 | } | |
528 | ||
529 | /* | |
530 | * Clear irqaction. Otherwise exit_irq_thread() would make | |
531 | * fuzz about an active irq thread going into nirvana. | |
532 | */ | |
533 | current->irqaction = NULL; | |
534 | return 0; | |
535 | } | |
536 | ||
537 | /* | |
538 | * Called from do_exit() | |
539 | */ | |
540 | void exit_irq_thread(void) | |
541 | { | |
542 | struct task_struct *tsk = current; | |
543 | ||
544 | if (!tsk->irqaction) | |
545 | return; | |
546 | ||
547 | printk(KERN_ERR | |
548 | "exiting task \"%s\" (%d) is an active IRQ thread (irq %d)\n", | |
549 | tsk->comm ? tsk->comm : "", tsk->pid, tsk->irqaction->irq); | |
550 | ||
551 | /* | |
552 | * Set the THREAD DIED flag to prevent further wakeups of the | |
553 | * soon to be gone threaded handler. | |
554 | */ | |
555 | set_bit(IRQTF_DIED, &tsk->irqaction->flags); | |
556 | } | |
557 | ||
1da177e4 LT |
558 | /* |
559 | * Internal function to register an irqaction - typically used to | |
560 | * allocate special interrupts that are part of the architecture. | |
561 | */ | |
d3c60047 | 562 | static int |
327ec569 | 563 | __setup_irq(unsigned int irq, struct irq_desc *desc, struct irqaction *new) |
1da177e4 | 564 | { |
f17c7545 | 565 | struct irqaction *old, **old_ptr; |
8b126b77 | 566 | const char *old_name = NULL; |
1da177e4 LT |
567 | unsigned long flags; |
568 | int shared = 0; | |
82736f4d | 569 | int ret; |
1da177e4 | 570 | |
7d94f7ca | 571 | if (!desc) |
c2b5a251 MW |
572 | return -EINVAL; |
573 | ||
f1c2662c | 574 | if (desc->chip == &no_irq_chip) |
1da177e4 LT |
575 | return -ENOSYS; |
576 | /* | |
577 | * Some drivers like serial.c use request_irq() heavily, | |
578 | * so we have to be careful not to interfere with a | |
579 | * running system. | |
580 | */ | |
3cca53b0 | 581 | if (new->flags & IRQF_SAMPLE_RANDOM) { |
1da177e4 LT |
582 | /* |
583 | * This function might sleep, we want to call it first, | |
584 | * outside of the atomic block. | |
585 | * Yes, this might clear the entropy pool if the wrong | |
586 | * driver is attempted to be loaded, without actually | |
587 | * installing a new handler, but is this really a problem, | |
588 | * only the sysadmin is able to do this. | |
589 | */ | |
590 | rand_initialize_irq(irq); | |
591 | } | |
592 | ||
3aa551c9 TG |
593 | /* |
594 | * Threaded handler ? | |
595 | */ | |
596 | if (new->thread_fn) { | |
597 | struct task_struct *t; | |
598 | ||
599 | t = kthread_create(irq_thread, new, "irq/%d-%s", irq, | |
600 | new->name); | |
601 | if (IS_ERR(t)) | |
602 | return PTR_ERR(t); | |
603 | /* | |
604 | * We keep the reference to the task struct even if | |
605 | * the thread dies to avoid that the interrupt code | |
606 | * references an already freed task_struct. | |
607 | */ | |
608 | get_task_struct(t); | |
609 | new->thread = t; | |
610 | wake_up_process(t); | |
611 | } | |
612 | ||
1da177e4 LT |
613 | /* |
614 | * The following block of code has to be executed atomically | |
615 | */ | |
06fcb0c6 | 616 | spin_lock_irqsave(&desc->lock, flags); |
f17c7545 IM |
617 | old_ptr = &desc->action; |
618 | old = *old_ptr; | |
06fcb0c6 | 619 | if (old) { |
e76de9f8 TG |
620 | /* |
621 | * Can't share interrupts unless both agree to and are | |
622 | * the same type (level, edge, polarity). So both flag | |
3cca53b0 | 623 | * fields must have IRQF_SHARED set and the bits which |
e76de9f8 TG |
624 | * set the trigger type must match. |
625 | */ | |
3cca53b0 | 626 | if (!((old->flags & new->flags) & IRQF_SHARED) || |
8b126b77 AM |
627 | ((old->flags ^ new->flags) & IRQF_TRIGGER_MASK)) { |
628 | old_name = old->name; | |
f5163427 | 629 | goto mismatch; |
8b126b77 | 630 | } |
f5163427 | 631 | |
284c6680 | 632 | #if defined(CONFIG_IRQ_PER_CPU) |
f5163427 | 633 | /* All handlers must agree on per-cpuness */ |
3cca53b0 TG |
634 | if ((old->flags & IRQF_PERCPU) != |
635 | (new->flags & IRQF_PERCPU)) | |
f5163427 DS |
636 | goto mismatch; |
637 | #endif | |
1da177e4 LT |
638 | |
639 | /* add new interrupt at end of irq queue */ | |
640 | do { | |
f17c7545 IM |
641 | old_ptr = &old->next; |
642 | old = *old_ptr; | |
1da177e4 LT |
643 | } while (old); |
644 | shared = 1; | |
645 | } | |
646 | ||
1da177e4 | 647 | if (!shared) { |
6a6de9ef | 648 | irq_chip_set_defaults(desc->chip); |
e76de9f8 | 649 | |
3aa551c9 TG |
650 | init_waitqueue_head(&desc->wait_for_threads); |
651 | ||
e76de9f8 | 652 | /* Setup the type (level, edge polarity) if configured: */ |
3cca53b0 | 653 | if (new->flags & IRQF_TRIGGER_MASK) { |
f2b662da DB |
654 | ret = __irq_set_trigger(desc, irq, |
655 | new->flags & IRQF_TRIGGER_MASK); | |
82736f4d | 656 | |
3aa551c9 TG |
657 | if (ret) |
658 | goto out_thread; | |
e76de9f8 TG |
659 | } else |
660 | compat_irq_chip_set_default_handler(desc); | |
82736f4d UKK |
661 | #if defined(CONFIG_IRQ_PER_CPU) |
662 | if (new->flags & IRQF_PERCPU) | |
663 | desc->status |= IRQ_PER_CPU; | |
664 | #endif | |
6a6de9ef | 665 | |
94d39e1f | 666 | desc->status &= ~(IRQ_AUTODETECT | IRQ_WAITING | |
1adb0850 | 667 | IRQ_INPROGRESS | IRQ_SPURIOUS_DISABLED); |
94d39e1f TG |
668 | |
669 | if (!(desc->status & IRQ_NOAUTOEN)) { | |
670 | desc->depth = 0; | |
671 | desc->status &= ~IRQ_DISABLED; | |
7e6e178a | 672 | desc->chip->startup(irq); |
e76de9f8 TG |
673 | } else |
674 | /* Undo nested disables: */ | |
675 | desc->depth = 1; | |
18404756 | 676 | |
612e3684 TG |
677 | /* Exclude IRQ from balancing if requested */ |
678 | if (new->flags & IRQF_NOBALANCING) | |
679 | desc->status |= IRQ_NO_BALANCING; | |
680 | ||
18404756 | 681 | /* Set default affinity mask once everything is setup */ |
548c8933 | 682 | setup_affinity(irq, desc); |
0c5d1eb7 DB |
683 | |
684 | } else if ((new->flags & IRQF_TRIGGER_MASK) | |
685 | && (new->flags & IRQF_TRIGGER_MASK) | |
686 | != (desc->status & IRQ_TYPE_SENSE_MASK)) { | |
687 | /* hope the handler works with the actual trigger mode... */ | |
688 | pr_warning("IRQ %d uses trigger mode %d; requested %d\n", | |
689 | irq, (int)(desc->status & IRQ_TYPE_SENSE_MASK), | |
690 | (int)(new->flags & IRQF_TRIGGER_MASK)); | |
1da177e4 | 691 | } |
82736f4d | 692 | |
f17c7545 | 693 | *old_ptr = new; |
82736f4d | 694 | |
8528b0f1 LT |
695 | /* Reset broken irq detection when installing new handler */ |
696 | desc->irq_count = 0; | |
697 | desc->irqs_unhandled = 0; | |
1adb0850 TG |
698 | |
699 | /* | |
700 | * Check whether we disabled the irq via the spurious handler | |
701 | * before. Reenable it and give it another chance. | |
702 | */ | |
703 | if (shared && (desc->status & IRQ_SPURIOUS_DISABLED)) { | |
704 | desc->status &= ~IRQ_SPURIOUS_DISABLED; | |
0a0c5168 | 705 | __enable_irq(desc, irq, false); |
1adb0850 TG |
706 | } |
707 | ||
06fcb0c6 | 708 | spin_unlock_irqrestore(&desc->lock, flags); |
1da177e4 LT |
709 | |
710 | new->irq = irq; | |
2c6927a3 | 711 | register_irq_proc(irq, desc); |
1da177e4 LT |
712 | new->dir = NULL; |
713 | register_handler_proc(irq, new); | |
714 | ||
715 | return 0; | |
f5163427 DS |
716 | |
717 | mismatch: | |
3f050447 | 718 | #ifdef CONFIG_DEBUG_SHIRQ |
3cca53b0 | 719 | if (!(new->flags & IRQF_PROBE_SHARED)) { |
e8c4b9d0 | 720 | printk(KERN_ERR "IRQ handler type mismatch for IRQ %d\n", irq); |
8b126b77 AM |
721 | if (old_name) |
722 | printk(KERN_ERR "current handler: %s\n", old_name); | |
13e87ec6 AM |
723 | dump_stack(); |
724 | } | |
3f050447 | 725 | #endif |
3aa551c9 TG |
726 | ret = -EBUSY; |
727 | ||
728 | out_thread: | |
8b126b77 | 729 | spin_unlock_irqrestore(&desc->lock, flags); |
3aa551c9 TG |
730 | if (new->thread) { |
731 | struct task_struct *t = new->thread; | |
732 | ||
733 | new->thread = NULL; | |
734 | if (likely(!test_bit(IRQTF_DIED, &new->thread_flags))) | |
735 | kthread_stop(t); | |
736 | put_task_struct(t); | |
737 | } | |
738 | return ret; | |
1da177e4 LT |
739 | } |
740 | ||
d3c60047 TG |
741 | /** |
742 | * setup_irq - setup an interrupt | |
743 | * @irq: Interrupt line to setup | |
744 | * @act: irqaction for the interrupt | |
745 | * | |
746 | * Used to statically setup interrupts in the early boot process. | |
747 | */ | |
748 | int setup_irq(unsigned int irq, struct irqaction *act) | |
749 | { | |
750 | struct irq_desc *desc = irq_to_desc(irq); | |
751 | ||
752 | return __setup_irq(irq, desc, act); | |
753 | } | |
eb53b4e8 | 754 | EXPORT_SYMBOL_GPL(setup_irq); |
d3c60047 | 755 | |
cbf94f06 MD |
756 | /* |
757 | * Internal function to unregister an irqaction - used to free | |
758 | * regular and special interrupts that are part of the architecture. | |
1da177e4 | 759 | */ |
cbf94f06 | 760 | static struct irqaction *__free_irq(unsigned int irq, void *dev_id) |
1da177e4 | 761 | { |
d3c60047 | 762 | struct irq_desc *desc = irq_to_desc(irq); |
f17c7545 | 763 | struct irqaction *action, **action_ptr; |
3aa551c9 | 764 | struct task_struct *irqthread; |
1da177e4 LT |
765 | unsigned long flags; |
766 | ||
ae88a23b | 767 | WARN(in_interrupt(), "Trying to free IRQ %d from IRQ context!\n", irq); |
7d94f7ca | 768 | |
7d94f7ca | 769 | if (!desc) |
f21cfb25 | 770 | return NULL; |
1da177e4 | 771 | |
06fcb0c6 | 772 | spin_lock_irqsave(&desc->lock, flags); |
ae88a23b IM |
773 | |
774 | /* | |
775 | * There can be multiple actions per IRQ descriptor, find the right | |
776 | * one based on the dev_id: | |
777 | */ | |
f17c7545 | 778 | action_ptr = &desc->action; |
1da177e4 | 779 | for (;;) { |
f17c7545 | 780 | action = *action_ptr; |
1da177e4 | 781 | |
ae88a23b IM |
782 | if (!action) { |
783 | WARN(1, "Trying to free already-free IRQ %d\n", irq); | |
784 | spin_unlock_irqrestore(&desc->lock, flags); | |
1da177e4 | 785 | |
f21cfb25 | 786 | return NULL; |
ae88a23b | 787 | } |
1da177e4 | 788 | |
8316e381 IM |
789 | if (action->dev_id == dev_id) |
790 | break; | |
f17c7545 | 791 | action_ptr = &action->next; |
ae88a23b | 792 | } |
dbce706e | 793 | |
ae88a23b | 794 | /* Found it - now remove it from the list of entries: */ |
f17c7545 | 795 | *action_ptr = action->next; |
ae88a23b IM |
796 | |
797 | /* Currently used only by UML, might disappear one day: */ | |
b77d6adc | 798 | #ifdef CONFIG_IRQ_RELEASE_METHOD |
ae88a23b IM |
799 | if (desc->chip->release) |
800 | desc->chip->release(irq, dev_id); | |
b77d6adc | 801 | #endif |
dbce706e | 802 | |
ae88a23b IM |
803 | /* If this was the last handler, shut down the IRQ line: */ |
804 | if (!desc->action) { | |
805 | desc->status |= IRQ_DISABLED; | |
806 | if (desc->chip->shutdown) | |
807 | desc->chip->shutdown(irq); | |
808 | else | |
809 | desc->chip->disable(irq); | |
810 | } | |
3aa551c9 TG |
811 | |
812 | irqthread = action->thread; | |
813 | action->thread = NULL; | |
814 | ||
ae88a23b IM |
815 | spin_unlock_irqrestore(&desc->lock, flags); |
816 | ||
817 | unregister_handler_proc(irq, action); | |
818 | ||
819 | /* Make sure it's not being used on another CPU: */ | |
820 | synchronize_irq(irq); | |
1da177e4 | 821 | |
3aa551c9 TG |
822 | if (irqthread) { |
823 | if (!test_bit(IRQTF_DIED, &action->thread_flags)) | |
824 | kthread_stop(irqthread); | |
825 | put_task_struct(irqthread); | |
826 | } | |
827 | ||
70edcd77 | 828 | #ifdef CONFIG_DEBUG_SHIRQ |
ae88a23b IM |
829 | /* |
830 | * It's a shared IRQ -- the driver ought to be prepared for an IRQ | |
831 | * event to happen even now it's being freed, so let's make sure that | |
832 | * is so by doing an extra call to the handler .... | |
833 | * | |
834 | * ( We do this after actually deregistering it, to make sure that a | |
835 | * 'real' IRQ doesn't run in * parallel with our fake. ) | |
836 | */ | |
837 | if (action->flags & IRQF_SHARED) { | |
838 | local_irq_save(flags); | |
839 | action->handler(irq, dev_id); | |
840 | local_irq_restore(flags); | |
1da177e4 | 841 | } |
ae88a23b | 842 | #endif |
f21cfb25 MD |
843 | return action; |
844 | } | |
845 | ||
cbf94f06 MD |
846 | /** |
847 | * remove_irq - free an interrupt | |
848 | * @irq: Interrupt line to free | |
849 | * @act: irqaction for the interrupt | |
850 | * | |
851 | * Used to remove interrupts statically setup by the early boot process. | |
852 | */ | |
853 | void remove_irq(unsigned int irq, struct irqaction *act) | |
854 | { | |
855 | __free_irq(irq, act->dev_id); | |
856 | } | |
eb53b4e8 | 857 | EXPORT_SYMBOL_GPL(remove_irq); |
cbf94f06 | 858 | |
f21cfb25 MD |
859 | /** |
860 | * free_irq - free an interrupt allocated with request_irq | |
861 | * @irq: Interrupt line to free | |
862 | * @dev_id: Device identity to free | |
863 | * | |
864 | * Remove an interrupt handler. The handler is removed and if the | |
865 | * interrupt line is no longer in use by any driver it is disabled. | |
866 | * On a shared IRQ the caller must ensure the interrupt is disabled | |
867 | * on the card it drives before calling this function. The function | |
868 | * does not return until any executing interrupts for this IRQ | |
869 | * have completed. | |
870 | * | |
871 | * This function must not be called from interrupt context. | |
872 | */ | |
873 | void free_irq(unsigned int irq, void *dev_id) | |
874 | { | |
cbf94f06 | 875 | kfree(__free_irq(irq, dev_id)); |
1da177e4 | 876 | } |
1da177e4 LT |
877 | EXPORT_SYMBOL(free_irq); |
878 | ||
879 | /** | |
3aa551c9 | 880 | * request_threaded_irq - allocate an interrupt line |
1da177e4 | 881 | * @irq: Interrupt line to allocate |
3aa551c9 TG |
882 | * @handler: Function to be called when the IRQ occurs. |
883 | * Primary handler for threaded interrupts | |
f48fe81e TG |
884 | * @thread_fn: Function called from the irq handler thread |
885 | * If NULL, no irq thread is created | |
1da177e4 LT |
886 | * @irqflags: Interrupt type flags |
887 | * @devname: An ascii name for the claiming device | |
888 | * @dev_id: A cookie passed back to the handler function | |
889 | * | |
890 | * This call allocates interrupt resources and enables the | |
891 | * interrupt line and IRQ handling. From the point this | |
892 | * call is made your handler function may be invoked. Since | |
893 | * your handler function must clear any interrupt the board | |
894 | * raises, you must take care both to initialise your hardware | |
895 | * and to set up the interrupt handler in the right order. | |
896 | * | |
3aa551c9 TG |
897 | * If you want to set up a threaded irq handler for your device |
898 | * then you need to supply @handler and @thread_fn. @handler ist | |
899 | * still called in hard interrupt context and has to check | |
900 | * whether the interrupt originates from the device. If yes it | |
901 | * needs to disable the interrupt on the device and return | |
39a2eddb | 902 | * IRQ_WAKE_THREAD which will wake up the handler thread and run |
3aa551c9 TG |
903 | * @thread_fn. This split handler design is necessary to support |
904 | * shared interrupts. | |
905 | * | |
1da177e4 LT |
906 | * Dev_id must be globally unique. Normally the address of the |
907 | * device data structure is used as the cookie. Since the handler | |
908 | * receives this value it makes sense to use it. | |
909 | * | |
910 | * If your interrupt is shared you must pass a non NULL dev_id | |
911 | * as this is required when freeing the interrupt. | |
912 | * | |
913 | * Flags: | |
914 | * | |
3cca53b0 TG |
915 | * IRQF_SHARED Interrupt is shared |
916 | * IRQF_DISABLED Disable local interrupts while processing | |
917 | * IRQF_SAMPLE_RANDOM The interrupt can be used for entropy | |
0c5d1eb7 | 918 | * IRQF_TRIGGER_* Specify active edge(s) or level |
1da177e4 LT |
919 | * |
920 | */ | |
3aa551c9 TG |
921 | int request_threaded_irq(unsigned int irq, irq_handler_t handler, |
922 | irq_handler_t thread_fn, unsigned long irqflags, | |
923 | const char *devname, void *dev_id) | |
1da177e4 | 924 | { |
06fcb0c6 | 925 | struct irqaction *action; |
08678b08 | 926 | struct irq_desc *desc; |
d3c60047 | 927 | int retval; |
1da177e4 | 928 | |
470c6623 DB |
929 | /* |
930 | * handle_IRQ_event() always ignores IRQF_DISABLED except for | |
931 | * the _first_ irqaction (sigh). That can cause oopsing, but | |
932 | * the behavior is classified as "will not fix" so we need to | |
933 | * start nudging drivers away from using that idiom. | |
934 | */ | |
327ec569 IM |
935 | if ((irqflags & (IRQF_SHARED|IRQF_DISABLED)) == |
936 | (IRQF_SHARED|IRQF_DISABLED)) { | |
937 | pr_warning( | |
938 | "IRQ %d/%s: IRQF_DISABLED is not guaranteed on shared IRQs\n", | |
939 | irq, devname); | |
940 | } | |
470c6623 | 941 | |
fbb9ce95 IM |
942 | #ifdef CONFIG_LOCKDEP |
943 | /* | |
944 | * Lockdep wants atomic interrupt handlers: | |
945 | */ | |
38515e90 | 946 | irqflags |= IRQF_DISABLED; |
fbb9ce95 | 947 | #endif |
1da177e4 LT |
948 | /* |
949 | * Sanity-check: shared interrupts must pass in a real dev-ID, | |
950 | * otherwise we'll have trouble later trying to figure out | |
951 | * which interrupt is which (messes up the interrupt freeing | |
952 | * logic etc). | |
953 | */ | |
3cca53b0 | 954 | if ((irqflags & IRQF_SHARED) && !dev_id) |
1da177e4 | 955 | return -EINVAL; |
7d94f7ca | 956 | |
cb5bc832 | 957 | desc = irq_to_desc(irq); |
7d94f7ca | 958 | if (!desc) |
1da177e4 | 959 | return -EINVAL; |
7d94f7ca | 960 | |
08678b08 | 961 | if (desc->status & IRQ_NOREQUEST) |
6550c775 | 962 | return -EINVAL; |
1da177e4 LT |
963 | if (!handler) |
964 | return -EINVAL; | |
965 | ||
45535732 | 966 | action = kzalloc(sizeof(struct irqaction), GFP_KERNEL); |
1da177e4 LT |
967 | if (!action) |
968 | return -ENOMEM; | |
969 | ||
970 | action->handler = handler; | |
3aa551c9 | 971 | action->thread_fn = thread_fn; |
1da177e4 | 972 | action->flags = irqflags; |
1da177e4 | 973 | action->name = devname; |
1da177e4 LT |
974 | action->dev_id = dev_id; |
975 | ||
d3c60047 | 976 | retval = __setup_irq(irq, desc, action); |
377bf1e4 AV |
977 | if (retval) |
978 | kfree(action); | |
979 | ||
a304e1b8 DW |
980 | #ifdef CONFIG_DEBUG_SHIRQ |
981 | if (irqflags & IRQF_SHARED) { | |
982 | /* | |
983 | * It's a shared IRQ -- the driver ought to be prepared for it | |
984 | * to happen immediately, so let's make sure.... | |
377bf1e4 AV |
985 | * We disable the irq to make sure that a 'real' IRQ doesn't |
986 | * run in parallel with our fake. | |
a304e1b8 | 987 | */ |
59845b1f | 988 | unsigned long flags; |
a304e1b8 | 989 | |
377bf1e4 | 990 | disable_irq(irq); |
59845b1f | 991 | local_irq_save(flags); |
377bf1e4 | 992 | |
59845b1f | 993 | handler(irq, dev_id); |
377bf1e4 | 994 | |
59845b1f | 995 | local_irq_restore(flags); |
377bf1e4 | 996 | enable_irq(irq); |
a304e1b8 DW |
997 | } |
998 | #endif | |
1da177e4 LT |
999 | return retval; |
1000 | } | |
3aa551c9 | 1001 | EXPORT_SYMBOL(request_threaded_irq); |