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