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 | ||
3aa551c9 TG |
83 | static void |
84 | irq_set_thread_affinity(struct irq_desc *desc, const struct cpumask *cpumask) | |
85 | { | |
86 | struct irqaction *action = desc->action; | |
87 | ||
88 | while (action) { | |
89 | if (action->thread) | |
90 | set_cpus_allowed_ptr(action->thread, cpumask); | |
91 | action = action->next; | |
92 | } | |
93 | } | |
94 | ||
771ee3b0 TG |
95 | /** |
96 | * irq_set_affinity - Set the irq affinity of a given irq | |
97 | * @irq: Interrupt to set affinity | |
98 | * @cpumask: cpumask | |
99 | * | |
100 | */ | |
0de26520 | 101 | int irq_set_affinity(unsigned int irq, const struct cpumask *cpumask) |
771ee3b0 | 102 | { |
08678b08 | 103 | struct irq_desc *desc = irq_to_desc(irq); |
f6d87f4b | 104 | unsigned long flags; |
771ee3b0 TG |
105 | |
106 | if (!desc->chip->set_affinity) | |
107 | return -EINVAL; | |
108 | ||
f6d87f4b TG |
109 | spin_lock_irqsave(&desc->lock, flags); |
110 | ||
771ee3b0 | 111 | #ifdef CONFIG_GENERIC_PENDING_IRQ |
6ec3cfec | 112 | if (desc->status & IRQ_MOVE_PCNTXT) |
72b1e22d | 113 | desc->chip->set_affinity(irq, cpumask); |
6ec3cfec | 114 | else { |
f6d87f4b | 115 | desc->status |= IRQ_MOVE_PENDING; |
7f7ace0c | 116 | cpumask_copy(desc->pending_mask, cpumask); |
f6d87f4b | 117 | } |
771ee3b0 | 118 | #else |
7f7ace0c | 119 | cpumask_copy(desc->affinity, cpumask); |
771ee3b0 TG |
120 | desc->chip->set_affinity(irq, cpumask); |
121 | #endif | |
3aa551c9 | 122 | irq_set_thread_affinity(desc, cpumask); |
f6d87f4b TG |
123 | desc->status |= IRQ_AFFINITY_SET; |
124 | spin_unlock_irqrestore(&desc->lock, flags); | |
771ee3b0 TG |
125 | return 0; |
126 | } | |
127 | ||
18404756 MK |
128 | #ifndef CONFIG_AUTO_IRQ_AFFINITY |
129 | /* | |
130 | * Generic version of the affinity autoselector. | |
131 | */ | |
548c8933 | 132 | static int setup_affinity(unsigned int irq, struct irq_desc *desc) |
18404756 | 133 | { |
18404756 MK |
134 | if (!irq_can_set_affinity(irq)) |
135 | return 0; | |
136 | ||
f6d87f4b TG |
137 | /* |
138 | * Preserve an userspace affinity setup, but make sure that | |
139 | * one of the targets is online. | |
140 | */ | |
612e3684 | 141 | if (desc->status & (IRQ_AFFINITY_SET | IRQ_NO_BALANCING)) { |
7f7ace0c | 142 | if (cpumask_any_and(desc->affinity, cpu_online_mask) |
0de26520 RR |
143 | < nr_cpu_ids) |
144 | goto set_affinity; | |
f6d87f4b TG |
145 | else |
146 | desc->status &= ~IRQ_AFFINITY_SET; | |
147 | } | |
148 | ||
7f7ace0c | 149 | cpumask_and(desc->affinity, cpu_online_mask, irq_default_affinity); |
0de26520 | 150 | set_affinity: |
7f7ace0c | 151 | desc->chip->set_affinity(irq, desc->affinity); |
18404756 | 152 | |
18404756 MK |
153 | return 0; |
154 | } | |
f6d87f4b | 155 | #else |
548c8933 | 156 | static inline int setup_affinity(unsigned int irq, struct irq_desc *d) |
f6d87f4b TG |
157 | { |
158 | return irq_select_affinity(irq); | |
159 | } | |
18404756 MK |
160 | #endif |
161 | ||
f6d87f4b TG |
162 | /* |
163 | * Called when affinity is set via /proc/irq | |
164 | */ | |
165 | int irq_select_affinity_usr(unsigned int irq) | |
166 | { | |
167 | struct irq_desc *desc = irq_to_desc(irq); | |
168 | unsigned long flags; | |
169 | int ret; | |
170 | ||
171 | spin_lock_irqsave(&desc->lock, flags); | |
548c8933 | 172 | ret = setup_affinity(irq, desc); |
3aa551c9 TG |
173 | if (!ret) |
174 | irq_set_thread_affinity(desc, desc->affinity); | |
f6d87f4b TG |
175 | spin_unlock_irqrestore(&desc->lock, flags); |
176 | ||
177 | return ret; | |
178 | } | |
179 | ||
180 | #else | |
548c8933 | 181 | static inline int setup_affinity(unsigned int irq, struct irq_desc *desc) |
f6d87f4b TG |
182 | { |
183 | return 0; | |
184 | } | |
1da177e4 LT |
185 | #endif |
186 | ||
0a0c5168 RW |
187 | void __disable_irq(struct irq_desc *desc, unsigned int irq, bool suspend) |
188 | { | |
189 | if (suspend) { | |
190 | if (!desc->action || (desc->action->flags & IRQF_TIMER)) | |
191 | return; | |
192 | desc->status |= IRQ_SUSPENDED; | |
193 | } | |
194 | ||
195 | if (!desc->depth++) { | |
196 | desc->status |= IRQ_DISABLED; | |
197 | desc->chip->disable(irq); | |
198 | } | |
199 | } | |
200 | ||
1da177e4 LT |
201 | /** |
202 | * disable_irq_nosync - disable an irq without waiting | |
203 | * @irq: Interrupt to disable | |
204 | * | |
205 | * Disable the selected interrupt line. Disables and Enables are | |
206 | * nested. | |
207 | * Unlike disable_irq(), this function does not ensure existing | |
208 | * instances of the IRQ handler have completed before returning. | |
209 | * | |
210 | * This function may be called from IRQ context. | |
211 | */ | |
212 | void disable_irq_nosync(unsigned int irq) | |
213 | { | |
d3c60047 | 214 | struct irq_desc *desc = irq_to_desc(irq); |
1da177e4 LT |
215 | unsigned long flags; |
216 | ||
7d94f7ca | 217 | if (!desc) |
c2b5a251 MW |
218 | return; |
219 | ||
1da177e4 | 220 | spin_lock_irqsave(&desc->lock, flags); |
0a0c5168 | 221 | __disable_irq(desc, irq, false); |
1da177e4 LT |
222 | spin_unlock_irqrestore(&desc->lock, flags); |
223 | } | |
1da177e4 LT |
224 | EXPORT_SYMBOL(disable_irq_nosync); |
225 | ||
226 | /** | |
227 | * disable_irq - disable an irq and wait for completion | |
228 | * @irq: Interrupt to disable | |
229 | * | |
230 | * Disable the selected interrupt line. Enables and Disables are | |
231 | * nested. | |
232 | * This function waits for any pending IRQ handlers for this interrupt | |
233 | * to complete before returning. If you use this function while | |
234 | * holding a resource the IRQ handler may need you will deadlock. | |
235 | * | |
236 | * This function may be called - with care - from IRQ context. | |
237 | */ | |
238 | void disable_irq(unsigned int irq) | |
239 | { | |
d3c60047 | 240 | struct irq_desc *desc = irq_to_desc(irq); |
1da177e4 | 241 | |
7d94f7ca | 242 | if (!desc) |
c2b5a251 MW |
243 | return; |
244 | ||
1da177e4 LT |
245 | disable_irq_nosync(irq); |
246 | if (desc->action) | |
247 | synchronize_irq(irq); | |
248 | } | |
1da177e4 LT |
249 | EXPORT_SYMBOL(disable_irq); |
250 | ||
0a0c5168 | 251 | void __enable_irq(struct irq_desc *desc, unsigned int irq, bool resume) |
1adb0850 | 252 | { |
0a0c5168 RW |
253 | if (resume) |
254 | desc->status &= ~IRQ_SUSPENDED; | |
255 | ||
1adb0850 TG |
256 | switch (desc->depth) { |
257 | case 0: | |
0a0c5168 | 258 | err_out: |
b8c512f6 | 259 | WARN(1, KERN_WARNING "Unbalanced enable for IRQ %d\n", irq); |
1adb0850 TG |
260 | break; |
261 | case 1: { | |
262 | unsigned int status = desc->status & ~IRQ_DISABLED; | |
263 | ||
0a0c5168 RW |
264 | if (desc->status & IRQ_SUSPENDED) |
265 | goto err_out; | |
1adb0850 TG |
266 | /* Prevent probing on this irq: */ |
267 | desc->status = status | IRQ_NOPROBE; | |
268 | check_irq_resend(desc, irq); | |
269 | /* fall-through */ | |
270 | } | |
271 | default: | |
272 | desc->depth--; | |
273 | } | |
274 | } | |
275 | ||
1da177e4 LT |
276 | /** |
277 | * enable_irq - enable handling of an irq | |
278 | * @irq: Interrupt to enable | |
279 | * | |
280 | * Undoes the effect of one call to disable_irq(). If this | |
281 | * matches the last disable, processing of interrupts on this | |
282 | * IRQ line is re-enabled. | |
283 | * | |
284 | * This function may be called from IRQ context. | |
285 | */ | |
286 | void enable_irq(unsigned int irq) | |
287 | { | |
d3c60047 | 288 | struct irq_desc *desc = irq_to_desc(irq); |
1da177e4 LT |
289 | unsigned long flags; |
290 | ||
7d94f7ca | 291 | if (!desc) |
c2b5a251 MW |
292 | return; |
293 | ||
1da177e4 | 294 | spin_lock_irqsave(&desc->lock, flags); |
0a0c5168 | 295 | __enable_irq(desc, irq, false); |
1da177e4 LT |
296 | spin_unlock_irqrestore(&desc->lock, flags); |
297 | } | |
1da177e4 LT |
298 | EXPORT_SYMBOL(enable_irq); |
299 | ||
0c5d1eb7 | 300 | static int set_irq_wake_real(unsigned int irq, unsigned int on) |
2db87321 | 301 | { |
08678b08 | 302 | struct irq_desc *desc = irq_to_desc(irq); |
2db87321 UKK |
303 | int ret = -ENXIO; |
304 | ||
305 | if (desc->chip->set_wake) | |
306 | ret = desc->chip->set_wake(irq, on); | |
307 | ||
308 | return ret; | |
309 | } | |
310 | ||
ba9a2331 TG |
311 | /** |
312 | * set_irq_wake - control irq power management wakeup | |
313 | * @irq: interrupt to control | |
314 | * @on: enable/disable power management wakeup | |
315 | * | |
15a647eb DB |
316 | * Enable/disable power management wakeup mode, which is |
317 | * disabled by default. Enables and disables must match, | |
318 | * just as they match for non-wakeup mode support. | |
319 | * | |
320 | * Wakeup mode lets this IRQ wake the system from sleep | |
321 | * states like "suspend to RAM". | |
ba9a2331 TG |
322 | */ |
323 | int set_irq_wake(unsigned int irq, unsigned int on) | |
324 | { | |
08678b08 | 325 | struct irq_desc *desc = irq_to_desc(irq); |
ba9a2331 | 326 | unsigned long flags; |
2db87321 | 327 | int ret = 0; |
ba9a2331 | 328 | |
15a647eb DB |
329 | /* wakeup-capable irqs can be shared between drivers that |
330 | * don't need to have the same sleep mode behaviors. | |
331 | */ | |
ba9a2331 | 332 | spin_lock_irqsave(&desc->lock, flags); |
15a647eb | 333 | if (on) { |
2db87321 UKK |
334 | if (desc->wake_depth++ == 0) { |
335 | ret = set_irq_wake_real(irq, on); | |
336 | if (ret) | |
337 | desc->wake_depth = 0; | |
338 | else | |
339 | desc->status |= IRQ_WAKEUP; | |
340 | } | |
15a647eb DB |
341 | } else { |
342 | if (desc->wake_depth == 0) { | |
7a2c4770 | 343 | WARN(1, "Unbalanced IRQ %d wake disable\n", irq); |
2db87321 UKK |
344 | } else if (--desc->wake_depth == 0) { |
345 | ret = set_irq_wake_real(irq, on); | |
346 | if (ret) | |
347 | desc->wake_depth = 1; | |
348 | else | |
349 | desc->status &= ~IRQ_WAKEUP; | |
350 | } | |
15a647eb | 351 | } |
2db87321 | 352 | |
ba9a2331 TG |
353 | spin_unlock_irqrestore(&desc->lock, flags); |
354 | return ret; | |
355 | } | |
356 | EXPORT_SYMBOL(set_irq_wake); | |
357 | ||
1da177e4 LT |
358 | /* |
359 | * Internal function that tells the architecture code whether a | |
360 | * particular irq has been exclusively allocated or is available | |
361 | * for driver use. | |
362 | */ | |
363 | int can_request_irq(unsigned int irq, unsigned long irqflags) | |
364 | { | |
d3c60047 | 365 | struct irq_desc *desc = irq_to_desc(irq); |
1da177e4 LT |
366 | struct irqaction *action; |
367 | ||
7d94f7ca YL |
368 | if (!desc) |
369 | return 0; | |
370 | ||
371 | if (desc->status & IRQ_NOREQUEST) | |
1da177e4 LT |
372 | return 0; |
373 | ||
08678b08 | 374 | action = desc->action; |
1da177e4 | 375 | if (action) |
3cca53b0 | 376 | if (irqflags & action->flags & IRQF_SHARED) |
1da177e4 LT |
377 | action = NULL; |
378 | ||
379 | return !action; | |
380 | } | |
381 | ||
6a6de9ef TG |
382 | void compat_irq_chip_set_default_handler(struct irq_desc *desc) |
383 | { | |
384 | /* | |
385 | * If the architecture still has not overriden | |
386 | * the flow handler then zap the default. This | |
387 | * should catch incorrect flow-type setting. | |
388 | */ | |
389 | if (desc->handle_irq == &handle_bad_irq) | |
390 | desc->handle_irq = NULL; | |
391 | } | |
392 | ||
0c5d1eb7 | 393 | int __irq_set_trigger(struct irq_desc *desc, unsigned int irq, |
82736f4d UKK |
394 | unsigned long flags) |
395 | { | |
396 | int ret; | |
0c5d1eb7 | 397 | struct irq_chip *chip = desc->chip; |
82736f4d UKK |
398 | |
399 | if (!chip || !chip->set_type) { | |
400 | /* | |
401 | * IRQF_TRIGGER_* but the PIC does not support multiple | |
402 | * flow-types? | |
403 | */ | |
3ff68a6a | 404 | pr_debug("No set_type function for IRQ %d (%s)\n", irq, |
82736f4d UKK |
405 | chip ? (chip->name ? : "unknown") : "unknown"); |
406 | return 0; | |
407 | } | |
408 | ||
f2b662da DB |
409 | /* caller masked out all except trigger mode flags */ |
410 | ret = chip->set_type(irq, flags); | |
82736f4d UKK |
411 | |
412 | if (ret) | |
c69ad71b | 413 | pr_err("setting trigger mode %d for irq %u failed (%pF)\n", |
f2b662da | 414 | (int)flags, irq, chip->set_type); |
0c5d1eb7 | 415 | else { |
f2b662da DB |
416 | if (flags & (IRQ_TYPE_LEVEL_LOW | IRQ_TYPE_LEVEL_HIGH)) |
417 | flags |= IRQ_LEVEL; | |
0c5d1eb7 | 418 | /* note that IRQF_TRIGGER_MASK == IRQ_TYPE_SENSE_MASK */ |
f2b662da DB |
419 | desc->status &= ~(IRQ_LEVEL | IRQ_TYPE_SENSE_MASK); |
420 | desc->status |= flags; | |
0c5d1eb7 | 421 | } |
82736f4d UKK |
422 | |
423 | return ret; | |
424 | } | |
425 | ||
3aa551c9 TG |
426 | static int irq_wait_for_interrupt(struct irqaction *action) |
427 | { | |
428 | while (!kthread_should_stop()) { | |
429 | set_current_state(TASK_INTERRUPTIBLE); | |
f48fe81e TG |
430 | |
431 | if (test_and_clear_bit(IRQTF_RUNTHREAD, | |
432 | &action->thread_flags)) { | |
3aa551c9 TG |
433 | __set_current_state(TASK_RUNNING); |
434 | return 0; | |
f48fe81e TG |
435 | } |
436 | schedule(); | |
3aa551c9 TG |
437 | } |
438 | return -1; | |
439 | } | |
440 | ||
441 | /* | |
442 | * Interrupt handler thread | |
443 | */ | |
444 | static int irq_thread(void *data) | |
445 | { | |
446 | struct sched_param param = { .sched_priority = MAX_USER_RT_PRIO/2, }; | |
447 | struct irqaction *action = data; | |
448 | struct irq_desc *desc = irq_to_desc(action->irq); | |
449 | int wake; | |
450 | ||
451 | sched_setscheduler(current, SCHED_FIFO, ¶m); | |
452 | current->irqaction = action; | |
453 | ||
454 | while (!irq_wait_for_interrupt(action)) { | |
455 | ||
456 | atomic_inc(&desc->threads_active); | |
457 | ||
458 | spin_lock_irq(&desc->lock); | |
459 | if (unlikely(desc->status & IRQ_DISABLED)) { | |
460 | /* | |
461 | * CHECKME: We might need a dedicated | |
462 | * IRQ_THREAD_PENDING flag here, which | |
463 | * retriggers the thread in check_irq_resend() | |
464 | * but AFAICT IRQ_PENDING should be fine as it | |
465 | * retriggers the interrupt itself --- tglx | |
466 | */ | |
467 | desc->status |= IRQ_PENDING; | |
468 | spin_unlock_irq(&desc->lock); | |
469 | } else { | |
470 | spin_unlock_irq(&desc->lock); | |
471 | ||
472 | action->thread_fn(action->irq, action->dev_id); | |
473 | } | |
474 | ||
475 | wake = atomic_dec_and_test(&desc->threads_active); | |
476 | ||
477 | if (wake && waitqueue_active(&desc->wait_for_threads)) | |
478 | wake_up(&desc->wait_for_threads); | |
479 | } | |
480 | ||
481 | /* | |
482 | * Clear irqaction. Otherwise exit_irq_thread() would make | |
483 | * fuzz about an active irq thread going into nirvana. | |
484 | */ | |
485 | current->irqaction = NULL; | |
486 | return 0; | |
487 | } | |
488 | ||
489 | /* | |
490 | * Called from do_exit() | |
491 | */ | |
492 | void exit_irq_thread(void) | |
493 | { | |
494 | struct task_struct *tsk = current; | |
495 | ||
496 | if (!tsk->irqaction) | |
497 | return; | |
498 | ||
499 | printk(KERN_ERR | |
500 | "exiting task \"%s\" (%d) is an active IRQ thread (irq %d)\n", | |
501 | tsk->comm ? tsk->comm : "", tsk->pid, tsk->irqaction->irq); | |
502 | ||
503 | /* | |
504 | * Set the THREAD DIED flag to prevent further wakeups of the | |
505 | * soon to be gone threaded handler. | |
506 | */ | |
507 | set_bit(IRQTF_DIED, &tsk->irqaction->flags); | |
508 | } | |
509 | ||
1da177e4 LT |
510 | /* |
511 | * Internal function to register an irqaction - typically used to | |
512 | * allocate special interrupts that are part of the architecture. | |
513 | */ | |
d3c60047 | 514 | static int |
327ec569 | 515 | __setup_irq(unsigned int irq, struct irq_desc *desc, struct irqaction *new) |
1da177e4 | 516 | { |
f17c7545 | 517 | struct irqaction *old, **old_ptr; |
8b126b77 | 518 | const char *old_name = NULL; |
1da177e4 LT |
519 | unsigned long flags; |
520 | int shared = 0; | |
82736f4d | 521 | int ret; |
1da177e4 | 522 | |
7d94f7ca | 523 | if (!desc) |
c2b5a251 MW |
524 | return -EINVAL; |
525 | ||
f1c2662c | 526 | if (desc->chip == &no_irq_chip) |
1da177e4 LT |
527 | return -ENOSYS; |
528 | /* | |
529 | * Some drivers like serial.c use request_irq() heavily, | |
530 | * so we have to be careful not to interfere with a | |
531 | * running system. | |
532 | */ | |
3cca53b0 | 533 | if (new->flags & IRQF_SAMPLE_RANDOM) { |
1da177e4 LT |
534 | /* |
535 | * This function might sleep, we want to call it first, | |
536 | * outside of the atomic block. | |
537 | * Yes, this might clear the entropy pool if the wrong | |
538 | * driver is attempted to be loaded, without actually | |
539 | * installing a new handler, but is this really a problem, | |
540 | * only the sysadmin is able to do this. | |
541 | */ | |
542 | rand_initialize_irq(irq); | |
543 | } | |
544 | ||
3aa551c9 TG |
545 | /* |
546 | * Threaded handler ? | |
547 | */ | |
548 | if (new->thread_fn) { | |
549 | struct task_struct *t; | |
550 | ||
551 | t = kthread_create(irq_thread, new, "irq/%d-%s", irq, | |
552 | new->name); | |
553 | if (IS_ERR(t)) | |
554 | return PTR_ERR(t); | |
555 | /* | |
556 | * We keep the reference to the task struct even if | |
557 | * the thread dies to avoid that the interrupt code | |
558 | * references an already freed task_struct. | |
559 | */ | |
560 | get_task_struct(t); | |
561 | new->thread = t; | |
562 | wake_up_process(t); | |
563 | } | |
564 | ||
1da177e4 LT |
565 | /* |
566 | * The following block of code has to be executed atomically | |
567 | */ | |
06fcb0c6 | 568 | spin_lock_irqsave(&desc->lock, flags); |
f17c7545 IM |
569 | old_ptr = &desc->action; |
570 | old = *old_ptr; | |
06fcb0c6 | 571 | if (old) { |
e76de9f8 TG |
572 | /* |
573 | * Can't share interrupts unless both agree to and are | |
574 | * the same type (level, edge, polarity). So both flag | |
3cca53b0 | 575 | * fields must have IRQF_SHARED set and the bits which |
e76de9f8 TG |
576 | * set the trigger type must match. |
577 | */ | |
3cca53b0 | 578 | if (!((old->flags & new->flags) & IRQF_SHARED) || |
8b126b77 AM |
579 | ((old->flags ^ new->flags) & IRQF_TRIGGER_MASK)) { |
580 | old_name = old->name; | |
f5163427 | 581 | goto mismatch; |
8b126b77 | 582 | } |
f5163427 | 583 | |
284c6680 | 584 | #if defined(CONFIG_IRQ_PER_CPU) |
f5163427 | 585 | /* All handlers must agree on per-cpuness */ |
3cca53b0 TG |
586 | if ((old->flags & IRQF_PERCPU) != |
587 | (new->flags & IRQF_PERCPU)) | |
f5163427 DS |
588 | goto mismatch; |
589 | #endif | |
1da177e4 LT |
590 | |
591 | /* add new interrupt at end of irq queue */ | |
592 | do { | |
f17c7545 IM |
593 | old_ptr = &old->next; |
594 | old = *old_ptr; | |
1da177e4 LT |
595 | } while (old); |
596 | shared = 1; | |
597 | } | |
598 | ||
1da177e4 | 599 | if (!shared) { |
6a6de9ef | 600 | irq_chip_set_defaults(desc->chip); |
e76de9f8 | 601 | |
3aa551c9 TG |
602 | init_waitqueue_head(&desc->wait_for_threads); |
603 | ||
e76de9f8 | 604 | /* Setup the type (level, edge polarity) if configured: */ |
3cca53b0 | 605 | if (new->flags & IRQF_TRIGGER_MASK) { |
f2b662da DB |
606 | ret = __irq_set_trigger(desc, irq, |
607 | new->flags & IRQF_TRIGGER_MASK); | |
82736f4d | 608 | |
3aa551c9 TG |
609 | if (ret) |
610 | goto out_thread; | |
e76de9f8 TG |
611 | } else |
612 | compat_irq_chip_set_default_handler(desc); | |
82736f4d UKK |
613 | #if defined(CONFIG_IRQ_PER_CPU) |
614 | if (new->flags & IRQF_PERCPU) | |
615 | desc->status |= IRQ_PER_CPU; | |
616 | #endif | |
6a6de9ef | 617 | |
94d39e1f | 618 | desc->status &= ~(IRQ_AUTODETECT | IRQ_WAITING | |
1adb0850 | 619 | IRQ_INPROGRESS | IRQ_SPURIOUS_DISABLED); |
94d39e1f TG |
620 | |
621 | if (!(desc->status & IRQ_NOAUTOEN)) { | |
622 | desc->depth = 0; | |
623 | desc->status &= ~IRQ_DISABLED; | |
7e6e178a | 624 | desc->chip->startup(irq); |
e76de9f8 TG |
625 | } else |
626 | /* Undo nested disables: */ | |
627 | desc->depth = 1; | |
18404756 | 628 | |
612e3684 TG |
629 | /* Exclude IRQ from balancing if requested */ |
630 | if (new->flags & IRQF_NOBALANCING) | |
631 | desc->status |= IRQ_NO_BALANCING; | |
632 | ||
18404756 | 633 | /* Set default affinity mask once everything is setup */ |
548c8933 | 634 | setup_affinity(irq, desc); |
0c5d1eb7 DB |
635 | |
636 | } else if ((new->flags & IRQF_TRIGGER_MASK) | |
637 | && (new->flags & IRQF_TRIGGER_MASK) | |
638 | != (desc->status & IRQ_TYPE_SENSE_MASK)) { | |
639 | /* hope the handler works with the actual trigger mode... */ | |
640 | pr_warning("IRQ %d uses trigger mode %d; requested %d\n", | |
641 | irq, (int)(desc->status & IRQ_TYPE_SENSE_MASK), | |
642 | (int)(new->flags & IRQF_TRIGGER_MASK)); | |
1da177e4 | 643 | } |
82736f4d | 644 | |
f17c7545 | 645 | *old_ptr = new; |
82736f4d | 646 | |
8528b0f1 LT |
647 | /* Reset broken irq detection when installing new handler */ |
648 | desc->irq_count = 0; | |
649 | desc->irqs_unhandled = 0; | |
1adb0850 TG |
650 | |
651 | /* | |
652 | * Check whether we disabled the irq via the spurious handler | |
653 | * before. Reenable it and give it another chance. | |
654 | */ | |
655 | if (shared && (desc->status & IRQ_SPURIOUS_DISABLED)) { | |
656 | desc->status &= ~IRQ_SPURIOUS_DISABLED; | |
0a0c5168 | 657 | __enable_irq(desc, irq, false); |
1adb0850 TG |
658 | } |
659 | ||
06fcb0c6 | 660 | spin_unlock_irqrestore(&desc->lock, flags); |
1da177e4 LT |
661 | |
662 | new->irq = irq; | |
2c6927a3 | 663 | register_irq_proc(irq, desc); |
1da177e4 LT |
664 | new->dir = NULL; |
665 | register_handler_proc(irq, new); | |
666 | ||
667 | return 0; | |
f5163427 DS |
668 | |
669 | mismatch: | |
3f050447 | 670 | #ifdef CONFIG_DEBUG_SHIRQ |
3cca53b0 | 671 | if (!(new->flags & IRQF_PROBE_SHARED)) { |
e8c4b9d0 | 672 | printk(KERN_ERR "IRQ handler type mismatch for IRQ %d\n", irq); |
8b126b77 AM |
673 | if (old_name) |
674 | printk(KERN_ERR "current handler: %s\n", old_name); | |
13e87ec6 AM |
675 | dump_stack(); |
676 | } | |
3f050447 | 677 | #endif |
3aa551c9 TG |
678 | ret = -EBUSY; |
679 | ||
680 | out_thread: | |
8b126b77 | 681 | spin_unlock_irqrestore(&desc->lock, flags); |
3aa551c9 TG |
682 | if (new->thread) { |
683 | struct task_struct *t = new->thread; | |
684 | ||
685 | new->thread = NULL; | |
686 | if (likely(!test_bit(IRQTF_DIED, &new->thread_flags))) | |
687 | kthread_stop(t); | |
688 | put_task_struct(t); | |
689 | } | |
690 | return ret; | |
1da177e4 LT |
691 | } |
692 | ||
d3c60047 TG |
693 | /** |
694 | * setup_irq - setup an interrupt | |
695 | * @irq: Interrupt line to setup | |
696 | * @act: irqaction for the interrupt | |
697 | * | |
698 | * Used to statically setup interrupts in the early boot process. | |
699 | */ | |
700 | int setup_irq(unsigned int irq, struct irqaction *act) | |
701 | { | |
702 | struct irq_desc *desc = irq_to_desc(irq); | |
703 | ||
704 | return __setup_irq(irq, desc, act); | |
705 | } | |
eb53b4e8 | 706 | EXPORT_SYMBOL_GPL(setup_irq); |
d3c60047 | 707 | |
cbf94f06 MD |
708 | /* |
709 | * Internal function to unregister an irqaction - used to free | |
710 | * regular and special interrupts that are part of the architecture. | |
1da177e4 | 711 | */ |
cbf94f06 | 712 | static struct irqaction *__free_irq(unsigned int irq, void *dev_id) |
1da177e4 | 713 | { |
d3c60047 | 714 | struct irq_desc *desc = irq_to_desc(irq); |
f17c7545 | 715 | struct irqaction *action, **action_ptr; |
3aa551c9 | 716 | struct task_struct *irqthread; |
1da177e4 LT |
717 | unsigned long flags; |
718 | ||
ae88a23b | 719 | WARN(in_interrupt(), "Trying to free IRQ %d from IRQ context!\n", irq); |
7d94f7ca | 720 | |
7d94f7ca | 721 | if (!desc) |
f21cfb25 | 722 | return NULL; |
1da177e4 | 723 | |
06fcb0c6 | 724 | spin_lock_irqsave(&desc->lock, flags); |
ae88a23b IM |
725 | |
726 | /* | |
727 | * There can be multiple actions per IRQ descriptor, find the right | |
728 | * one based on the dev_id: | |
729 | */ | |
f17c7545 | 730 | action_ptr = &desc->action; |
1da177e4 | 731 | for (;;) { |
f17c7545 | 732 | action = *action_ptr; |
1da177e4 | 733 | |
ae88a23b IM |
734 | if (!action) { |
735 | WARN(1, "Trying to free already-free IRQ %d\n", irq); | |
736 | spin_unlock_irqrestore(&desc->lock, flags); | |
1da177e4 | 737 | |
f21cfb25 | 738 | return NULL; |
ae88a23b | 739 | } |
1da177e4 | 740 | |
8316e381 IM |
741 | if (action->dev_id == dev_id) |
742 | break; | |
f17c7545 | 743 | action_ptr = &action->next; |
ae88a23b | 744 | } |
dbce706e | 745 | |
ae88a23b | 746 | /* Found it - now remove it from the list of entries: */ |
f17c7545 | 747 | *action_ptr = action->next; |
ae88a23b IM |
748 | |
749 | /* Currently used only by UML, might disappear one day: */ | |
b77d6adc | 750 | #ifdef CONFIG_IRQ_RELEASE_METHOD |
ae88a23b IM |
751 | if (desc->chip->release) |
752 | desc->chip->release(irq, dev_id); | |
b77d6adc | 753 | #endif |
dbce706e | 754 | |
ae88a23b IM |
755 | /* If this was the last handler, shut down the IRQ line: */ |
756 | if (!desc->action) { | |
757 | desc->status |= IRQ_DISABLED; | |
758 | if (desc->chip->shutdown) | |
759 | desc->chip->shutdown(irq); | |
760 | else | |
761 | desc->chip->disable(irq); | |
762 | } | |
3aa551c9 TG |
763 | |
764 | irqthread = action->thread; | |
765 | action->thread = NULL; | |
766 | ||
ae88a23b IM |
767 | spin_unlock_irqrestore(&desc->lock, flags); |
768 | ||
769 | unregister_handler_proc(irq, action); | |
770 | ||
771 | /* Make sure it's not being used on another CPU: */ | |
772 | synchronize_irq(irq); | |
1da177e4 | 773 | |
3aa551c9 TG |
774 | if (irqthread) { |
775 | if (!test_bit(IRQTF_DIED, &action->thread_flags)) | |
776 | kthread_stop(irqthread); | |
777 | put_task_struct(irqthread); | |
778 | } | |
779 | ||
70edcd77 | 780 | #ifdef CONFIG_DEBUG_SHIRQ |
ae88a23b IM |
781 | /* |
782 | * It's a shared IRQ -- the driver ought to be prepared for an IRQ | |
783 | * event to happen even now it's being freed, so let's make sure that | |
784 | * is so by doing an extra call to the handler .... | |
785 | * | |
786 | * ( We do this after actually deregistering it, to make sure that a | |
787 | * 'real' IRQ doesn't run in * parallel with our fake. ) | |
788 | */ | |
789 | if (action->flags & IRQF_SHARED) { | |
790 | local_irq_save(flags); | |
791 | action->handler(irq, dev_id); | |
792 | local_irq_restore(flags); | |
1da177e4 | 793 | } |
ae88a23b | 794 | #endif |
f21cfb25 MD |
795 | return action; |
796 | } | |
797 | ||
cbf94f06 MD |
798 | /** |
799 | * remove_irq - free an interrupt | |
800 | * @irq: Interrupt line to free | |
801 | * @act: irqaction for the interrupt | |
802 | * | |
803 | * Used to remove interrupts statically setup by the early boot process. | |
804 | */ | |
805 | void remove_irq(unsigned int irq, struct irqaction *act) | |
806 | { | |
807 | __free_irq(irq, act->dev_id); | |
808 | } | |
eb53b4e8 | 809 | EXPORT_SYMBOL_GPL(remove_irq); |
cbf94f06 | 810 | |
f21cfb25 MD |
811 | /** |
812 | * free_irq - free an interrupt allocated with request_irq | |
813 | * @irq: Interrupt line to free | |
814 | * @dev_id: Device identity to free | |
815 | * | |
816 | * Remove an interrupt handler. The handler is removed and if the | |
817 | * interrupt line is no longer in use by any driver it is disabled. | |
818 | * On a shared IRQ the caller must ensure the interrupt is disabled | |
819 | * on the card it drives before calling this function. The function | |
820 | * does not return until any executing interrupts for this IRQ | |
821 | * have completed. | |
822 | * | |
823 | * This function must not be called from interrupt context. | |
824 | */ | |
825 | void free_irq(unsigned int irq, void *dev_id) | |
826 | { | |
cbf94f06 | 827 | kfree(__free_irq(irq, dev_id)); |
1da177e4 | 828 | } |
1da177e4 LT |
829 | EXPORT_SYMBOL(free_irq); |
830 | ||
831 | /** | |
3aa551c9 | 832 | * request_threaded_irq - allocate an interrupt line |
1da177e4 | 833 | * @irq: Interrupt line to allocate |
3aa551c9 TG |
834 | * @handler: Function to be called when the IRQ occurs. |
835 | * Primary handler for threaded interrupts | |
f48fe81e TG |
836 | * @thread_fn: Function called from the irq handler thread |
837 | * If NULL, no irq thread is created | |
1da177e4 LT |
838 | * @irqflags: Interrupt type flags |
839 | * @devname: An ascii name for the claiming device | |
840 | * @dev_id: A cookie passed back to the handler function | |
841 | * | |
842 | * This call allocates interrupt resources and enables the | |
843 | * interrupt line and IRQ handling. From the point this | |
844 | * call is made your handler function may be invoked. Since | |
845 | * your handler function must clear any interrupt the board | |
846 | * raises, you must take care both to initialise your hardware | |
847 | * and to set up the interrupt handler in the right order. | |
848 | * | |
3aa551c9 TG |
849 | * If you want to set up a threaded irq handler for your device |
850 | * then you need to supply @handler and @thread_fn. @handler ist | |
851 | * still called in hard interrupt context and has to check | |
852 | * whether the interrupt originates from the device. If yes it | |
853 | * needs to disable the interrupt on the device and return | |
854 | * IRQ_THREAD_WAKE which will wake up the handler thread and run | |
855 | * @thread_fn. This split handler design is necessary to support | |
856 | * shared interrupts. | |
857 | * | |
1da177e4 LT |
858 | * Dev_id must be globally unique. Normally the address of the |
859 | * device data structure is used as the cookie. Since the handler | |
860 | * receives this value it makes sense to use it. | |
861 | * | |
862 | * If your interrupt is shared you must pass a non NULL dev_id | |
863 | * as this is required when freeing the interrupt. | |
864 | * | |
865 | * Flags: | |
866 | * | |
3cca53b0 TG |
867 | * IRQF_SHARED Interrupt is shared |
868 | * IRQF_DISABLED Disable local interrupts while processing | |
869 | * IRQF_SAMPLE_RANDOM The interrupt can be used for entropy | |
0c5d1eb7 | 870 | * IRQF_TRIGGER_* Specify active edge(s) or level |
1da177e4 LT |
871 | * |
872 | */ | |
3aa551c9 TG |
873 | int request_threaded_irq(unsigned int irq, irq_handler_t handler, |
874 | irq_handler_t thread_fn, unsigned long irqflags, | |
875 | const char *devname, void *dev_id) | |
1da177e4 | 876 | { |
06fcb0c6 | 877 | struct irqaction *action; |
08678b08 | 878 | struct irq_desc *desc; |
d3c60047 | 879 | int retval; |
1da177e4 | 880 | |
470c6623 DB |
881 | /* |
882 | * handle_IRQ_event() always ignores IRQF_DISABLED except for | |
883 | * the _first_ irqaction (sigh). That can cause oopsing, but | |
884 | * the behavior is classified as "will not fix" so we need to | |
885 | * start nudging drivers away from using that idiom. | |
886 | */ | |
327ec569 IM |
887 | if ((irqflags & (IRQF_SHARED|IRQF_DISABLED)) == |
888 | (IRQF_SHARED|IRQF_DISABLED)) { | |
889 | pr_warning( | |
890 | "IRQ %d/%s: IRQF_DISABLED is not guaranteed on shared IRQs\n", | |
891 | irq, devname); | |
892 | } | |
470c6623 | 893 | |
fbb9ce95 IM |
894 | #ifdef CONFIG_LOCKDEP |
895 | /* | |
896 | * Lockdep wants atomic interrupt handlers: | |
897 | */ | |
38515e90 | 898 | irqflags |= IRQF_DISABLED; |
fbb9ce95 | 899 | #endif |
1da177e4 LT |
900 | /* |
901 | * Sanity-check: shared interrupts must pass in a real dev-ID, | |
902 | * otherwise we'll have trouble later trying to figure out | |
903 | * which interrupt is which (messes up the interrupt freeing | |
904 | * logic etc). | |
905 | */ | |
3cca53b0 | 906 | if ((irqflags & IRQF_SHARED) && !dev_id) |
1da177e4 | 907 | return -EINVAL; |
7d94f7ca | 908 | |
cb5bc832 | 909 | desc = irq_to_desc(irq); |
7d94f7ca | 910 | if (!desc) |
1da177e4 | 911 | return -EINVAL; |
7d94f7ca | 912 | |
08678b08 | 913 | if (desc->status & IRQ_NOREQUEST) |
6550c775 | 914 | return -EINVAL; |
1da177e4 LT |
915 | if (!handler) |
916 | return -EINVAL; | |
917 | ||
45535732 | 918 | action = kzalloc(sizeof(struct irqaction), GFP_KERNEL); |
1da177e4 LT |
919 | if (!action) |
920 | return -ENOMEM; | |
921 | ||
922 | action->handler = handler; | |
3aa551c9 | 923 | action->thread_fn = thread_fn; |
1da177e4 | 924 | action->flags = irqflags; |
1da177e4 | 925 | action->name = devname; |
1da177e4 LT |
926 | action->dev_id = dev_id; |
927 | ||
d3c60047 | 928 | retval = __setup_irq(irq, desc, action); |
377bf1e4 AV |
929 | if (retval) |
930 | kfree(action); | |
931 | ||
a304e1b8 DW |
932 | #ifdef CONFIG_DEBUG_SHIRQ |
933 | if (irqflags & IRQF_SHARED) { | |
934 | /* | |
935 | * It's a shared IRQ -- the driver ought to be prepared for it | |
936 | * to happen immediately, so let's make sure.... | |
377bf1e4 AV |
937 | * We disable the irq to make sure that a 'real' IRQ doesn't |
938 | * run in parallel with our fake. | |
a304e1b8 | 939 | */ |
59845b1f | 940 | unsigned long flags; |
a304e1b8 | 941 | |
377bf1e4 | 942 | disable_irq(irq); |
59845b1f | 943 | local_irq_save(flags); |
377bf1e4 | 944 | |
59845b1f | 945 | handler(irq, dev_id); |
377bf1e4 | 946 | |
59845b1f | 947 | local_irq_restore(flags); |
377bf1e4 | 948 | enable_irq(irq); |
a304e1b8 DW |
949 | } |
950 | #endif | |
1da177e4 LT |
951 | return retval; |
952 | } | |
3aa551c9 | 953 | EXPORT_SYMBOL(request_threaded_irq); |