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Commit | Line | Data |
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1da177e4 LT |
1 | /* |
2 | * linux/kernel/irq/manage.c | |
3 | * | |
a34db9b2 IM |
4 | * Copyright (C) 1992, 1998-2006 Linus Torvalds, Ingo Molnar |
5 | * Copyright (C) 2005-2006 Thomas Gleixner | |
1da177e4 LT |
6 | * |
7 | * This file contains driver APIs to the irq subsystem. | |
8 | */ | |
9 | ||
10 | #include <linux/irq.h> | |
11 | #include <linux/module.h> | |
12 | #include <linux/random.h> | |
13 | #include <linux/interrupt.h> | |
1aeb272c | 14 | #include <linux/slab.h> |
1da177e4 LT |
15 | |
16 | #include "internals.h" | |
17 | ||
1267a8df | 18 | #if defined(CONFIG_SMP) && defined(CONFIG_GENERIC_HARDIRQS) |
d036e67b | 19 | cpumask_var_t irq_default_affinity; |
1da177e4 | 20 | |
1da177e4 LT |
21 | /** |
22 | * synchronize_irq - wait for pending IRQ handlers (on other CPUs) | |
1e5d5331 | 23 | * @irq: interrupt number to wait for |
1da177e4 LT |
24 | * |
25 | * This function waits for any pending IRQ handlers for this interrupt | |
26 | * to complete before returning. If you use this function while | |
27 | * holding a resource the IRQ handler may need you will deadlock. | |
28 | * | |
29 | * This function may be called - with care - from IRQ context. | |
30 | */ | |
31 | void synchronize_irq(unsigned int irq) | |
32 | { | |
cb5bc832 | 33 | struct irq_desc *desc = irq_to_desc(irq); |
a98ce5c6 | 34 | unsigned int status; |
1da177e4 | 35 | |
7d94f7ca | 36 | if (!desc) |
c2b5a251 MW |
37 | return; |
38 | ||
a98ce5c6 HX |
39 | do { |
40 | unsigned long flags; | |
41 | ||
42 | /* | |
43 | * Wait until we're out of the critical section. This might | |
44 | * give the wrong answer due to the lack of memory barriers. | |
45 | */ | |
46 | while (desc->status & IRQ_INPROGRESS) | |
47 | cpu_relax(); | |
48 | ||
49 | /* Ok, that indicated we're done: double-check carefully. */ | |
50 | spin_lock_irqsave(&desc->lock, flags); | |
51 | status = desc->status; | |
52 | spin_unlock_irqrestore(&desc->lock, flags); | |
53 | ||
54 | /* Oops, that failed? */ | |
55 | } while (status & IRQ_INPROGRESS); | |
1da177e4 | 56 | } |
1da177e4 LT |
57 | EXPORT_SYMBOL(synchronize_irq); |
58 | ||
771ee3b0 TG |
59 | /** |
60 | * irq_can_set_affinity - Check if the affinity of a given irq can be set | |
61 | * @irq: Interrupt to check | |
62 | * | |
63 | */ | |
64 | int irq_can_set_affinity(unsigned int irq) | |
65 | { | |
08678b08 | 66 | struct irq_desc *desc = irq_to_desc(irq); |
771ee3b0 TG |
67 | |
68 | if (CHECK_IRQ_PER_CPU(desc->status) || !desc->chip || | |
69 | !desc->chip->set_affinity) | |
70 | return 0; | |
71 | ||
72 | return 1; | |
73 | } | |
74 | ||
75 | /** | |
76 | * irq_set_affinity - Set the irq affinity of a given irq | |
77 | * @irq: Interrupt to set affinity | |
78 | * @cpumask: cpumask | |
79 | * | |
80 | */ | |
0de26520 | 81 | int irq_set_affinity(unsigned int irq, const struct cpumask *cpumask) |
771ee3b0 | 82 | { |
08678b08 | 83 | struct irq_desc *desc = irq_to_desc(irq); |
f6d87f4b | 84 | unsigned long flags; |
771ee3b0 TG |
85 | |
86 | if (!desc->chip->set_affinity) | |
87 | return -EINVAL; | |
88 | ||
f6d87f4b TG |
89 | spin_lock_irqsave(&desc->lock, flags); |
90 | ||
771ee3b0 | 91 | #ifdef CONFIG_GENERIC_PENDING_IRQ |
932775a4 | 92 | if (desc->status & IRQ_MOVE_PCNTXT || desc->status & IRQ_DISABLED) { |
7f7ace0c | 93 | cpumask_copy(desc->affinity, cpumask); |
72b1e22d | 94 | desc->chip->set_affinity(irq, cpumask); |
f6d87f4b TG |
95 | } else { |
96 | desc->status |= IRQ_MOVE_PENDING; | |
7f7ace0c | 97 | cpumask_copy(desc->pending_mask, cpumask); |
f6d87f4b | 98 | } |
771ee3b0 | 99 | #else |
7f7ace0c | 100 | cpumask_copy(desc->affinity, cpumask); |
771ee3b0 TG |
101 | desc->chip->set_affinity(irq, cpumask); |
102 | #endif | |
f6d87f4b TG |
103 | desc->status |= IRQ_AFFINITY_SET; |
104 | spin_unlock_irqrestore(&desc->lock, flags); | |
771ee3b0 TG |
105 | return 0; |
106 | } | |
107 | ||
18404756 MK |
108 | #ifndef CONFIG_AUTO_IRQ_AFFINITY |
109 | /* | |
110 | * Generic version of the affinity autoselector. | |
111 | */ | |
548c8933 | 112 | static int setup_affinity(unsigned int irq, struct irq_desc *desc) |
18404756 | 113 | { |
18404756 MK |
114 | if (!irq_can_set_affinity(irq)) |
115 | return 0; | |
116 | ||
f6d87f4b TG |
117 | /* |
118 | * Preserve an userspace affinity setup, but make sure that | |
119 | * one of the targets is online. | |
120 | */ | |
612e3684 | 121 | if (desc->status & (IRQ_AFFINITY_SET | IRQ_NO_BALANCING)) { |
7f7ace0c | 122 | if (cpumask_any_and(desc->affinity, cpu_online_mask) |
0de26520 RR |
123 | < nr_cpu_ids) |
124 | goto set_affinity; | |
f6d87f4b TG |
125 | else |
126 | desc->status &= ~IRQ_AFFINITY_SET; | |
127 | } | |
128 | ||
7f7ace0c | 129 | cpumask_and(desc->affinity, cpu_online_mask, irq_default_affinity); |
0de26520 | 130 | set_affinity: |
7f7ace0c | 131 | desc->chip->set_affinity(irq, desc->affinity); |
18404756 | 132 | |
18404756 MK |
133 | return 0; |
134 | } | |
f6d87f4b | 135 | #else |
548c8933 | 136 | static inline int setup_affinity(unsigned int irq, struct irq_desc *d) |
f6d87f4b TG |
137 | { |
138 | return irq_select_affinity(irq); | |
139 | } | |
18404756 MK |
140 | #endif |
141 | ||
f6d87f4b TG |
142 | /* |
143 | * Called when affinity is set via /proc/irq | |
144 | */ | |
145 | int irq_select_affinity_usr(unsigned int irq) | |
146 | { | |
147 | struct irq_desc *desc = irq_to_desc(irq); | |
148 | unsigned long flags; | |
149 | int ret; | |
150 | ||
151 | spin_lock_irqsave(&desc->lock, flags); | |
548c8933 | 152 | ret = setup_affinity(irq, desc); |
f6d87f4b TG |
153 | spin_unlock_irqrestore(&desc->lock, flags); |
154 | ||
155 | return ret; | |
156 | } | |
157 | ||
158 | #else | |
548c8933 | 159 | static inline int setup_affinity(unsigned int irq, struct irq_desc *desc) |
f6d87f4b TG |
160 | { |
161 | return 0; | |
162 | } | |
1da177e4 LT |
163 | #endif |
164 | ||
0a0c5168 RW |
165 | void __disable_irq(struct irq_desc *desc, unsigned int irq, bool suspend) |
166 | { | |
167 | if (suspend) { | |
168 | if (!desc->action || (desc->action->flags & IRQF_TIMER)) | |
169 | return; | |
170 | desc->status |= IRQ_SUSPENDED; | |
171 | } | |
172 | ||
173 | if (!desc->depth++) { | |
174 | desc->status |= IRQ_DISABLED; | |
175 | desc->chip->disable(irq); | |
176 | } | |
177 | } | |
178 | ||
1da177e4 LT |
179 | /** |
180 | * disable_irq_nosync - disable an irq without waiting | |
181 | * @irq: Interrupt to disable | |
182 | * | |
183 | * Disable the selected interrupt line. Disables and Enables are | |
184 | * nested. | |
185 | * Unlike disable_irq(), this function does not ensure existing | |
186 | * instances of the IRQ handler have completed before returning. | |
187 | * | |
188 | * This function may be called from IRQ context. | |
189 | */ | |
190 | void disable_irq_nosync(unsigned int irq) | |
191 | { | |
d3c60047 | 192 | struct irq_desc *desc = irq_to_desc(irq); |
1da177e4 LT |
193 | unsigned long flags; |
194 | ||
7d94f7ca | 195 | if (!desc) |
c2b5a251 MW |
196 | return; |
197 | ||
1da177e4 | 198 | spin_lock_irqsave(&desc->lock, flags); |
0a0c5168 | 199 | __disable_irq(desc, irq, false); |
1da177e4 LT |
200 | spin_unlock_irqrestore(&desc->lock, flags); |
201 | } | |
1da177e4 LT |
202 | EXPORT_SYMBOL(disable_irq_nosync); |
203 | ||
204 | /** | |
205 | * disable_irq - disable an irq and wait for completion | |
206 | * @irq: Interrupt to disable | |
207 | * | |
208 | * Disable the selected interrupt line. Enables and Disables are | |
209 | * nested. | |
210 | * This function waits for any pending IRQ handlers for this interrupt | |
211 | * to complete before returning. If you use this function while | |
212 | * holding a resource the IRQ handler may need you will deadlock. | |
213 | * | |
214 | * This function may be called - with care - from IRQ context. | |
215 | */ | |
216 | void disable_irq(unsigned int irq) | |
217 | { | |
d3c60047 | 218 | struct irq_desc *desc = irq_to_desc(irq); |
1da177e4 | 219 | |
7d94f7ca | 220 | if (!desc) |
c2b5a251 MW |
221 | return; |
222 | ||
1da177e4 LT |
223 | disable_irq_nosync(irq); |
224 | if (desc->action) | |
225 | synchronize_irq(irq); | |
226 | } | |
1da177e4 LT |
227 | EXPORT_SYMBOL(disable_irq); |
228 | ||
0a0c5168 | 229 | void __enable_irq(struct irq_desc *desc, unsigned int irq, bool resume) |
1adb0850 | 230 | { |
0a0c5168 RW |
231 | if (resume) |
232 | desc->status &= ~IRQ_SUSPENDED; | |
233 | ||
1adb0850 TG |
234 | switch (desc->depth) { |
235 | case 0: | |
0a0c5168 | 236 | err_out: |
b8c512f6 | 237 | WARN(1, KERN_WARNING "Unbalanced enable for IRQ %d\n", irq); |
1adb0850 TG |
238 | break; |
239 | case 1: { | |
240 | unsigned int status = desc->status & ~IRQ_DISABLED; | |
241 | ||
0a0c5168 RW |
242 | if (desc->status & IRQ_SUSPENDED) |
243 | goto err_out; | |
1adb0850 TG |
244 | /* Prevent probing on this irq: */ |
245 | desc->status = status | IRQ_NOPROBE; | |
246 | check_irq_resend(desc, irq); | |
247 | /* fall-through */ | |
248 | } | |
249 | default: | |
250 | desc->depth--; | |
251 | } | |
252 | } | |
253 | ||
1da177e4 LT |
254 | /** |
255 | * enable_irq - enable handling of an irq | |
256 | * @irq: Interrupt to enable | |
257 | * | |
258 | * Undoes the effect of one call to disable_irq(). If this | |
259 | * matches the last disable, processing of interrupts on this | |
260 | * IRQ line is re-enabled. | |
261 | * | |
262 | * This function may be called from IRQ context. | |
263 | */ | |
264 | void enable_irq(unsigned int irq) | |
265 | { | |
d3c60047 | 266 | struct irq_desc *desc = irq_to_desc(irq); |
1da177e4 LT |
267 | unsigned long flags; |
268 | ||
7d94f7ca | 269 | if (!desc) |
c2b5a251 MW |
270 | return; |
271 | ||
1da177e4 | 272 | spin_lock_irqsave(&desc->lock, flags); |
0a0c5168 | 273 | __enable_irq(desc, irq, false); |
1da177e4 LT |
274 | spin_unlock_irqrestore(&desc->lock, flags); |
275 | } | |
1da177e4 LT |
276 | EXPORT_SYMBOL(enable_irq); |
277 | ||
0c5d1eb7 | 278 | static int set_irq_wake_real(unsigned int irq, unsigned int on) |
2db87321 | 279 | { |
08678b08 | 280 | struct irq_desc *desc = irq_to_desc(irq); |
2db87321 UKK |
281 | int ret = -ENXIO; |
282 | ||
283 | if (desc->chip->set_wake) | |
284 | ret = desc->chip->set_wake(irq, on); | |
285 | ||
286 | return ret; | |
287 | } | |
288 | ||
ba9a2331 TG |
289 | /** |
290 | * set_irq_wake - control irq power management wakeup | |
291 | * @irq: interrupt to control | |
292 | * @on: enable/disable power management wakeup | |
293 | * | |
15a647eb DB |
294 | * Enable/disable power management wakeup mode, which is |
295 | * disabled by default. Enables and disables must match, | |
296 | * just as they match for non-wakeup mode support. | |
297 | * | |
298 | * Wakeup mode lets this IRQ wake the system from sleep | |
299 | * states like "suspend to RAM". | |
ba9a2331 TG |
300 | */ |
301 | int set_irq_wake(unsigned int irq, unsigned int on) | |
302 | { | |
08678b08 | 303 | struct irq_desc *desc = irq_to_desc(irq); |
ba9a2331 | 304 | unsigned long flags; |
2db87321 | 305 | int ret = 0; |
ba9a2331 | 306 | |
15a647eb DB |
307 | /* wakeup-capable irqs can be shared between drivers that |
308 | * don't need to have the same sleep mode behaviors. | |
309 | */ | |
ba9a2331 | 310 | spin_lock_irqsave(&desc->lock, flags); |
15a647eb | 311 | if (on) { |
2db87321 UKK |
312 | if (desc->wake_depth++ == 0) { |
313 | ret = set_irq_wake_real(irq, on); | |
314 | if (ret) | |
315 | desc->wake_depth = 0; | |
316 | else | |
317 | desc->status |= IRQ_WAKEUP; | |
318 | } | |
15a647eb DB |
319 | } else { |
320 | if (desc->wake_depth == 0) { | |
7a2c4770 | 321 | WARN(1, "Unbalanced IRQ %d wake disable\n", irq); |
2db87321 UKK |
322 | } else if (--desc->wake_depth == 0) { |
323 | ret = set_irq_wake_real(irq, on); | |
324 | if (ret) | |
325 | desc->wake_depth = 1; | |
326 | else | |
327 | desc->status &= ~IRQ_WAKEUP; | |
328 | } | |
15a647eb | 329 | } |
2db87321 | 330 | |
ba9a2331 TG |
331 | spin_unlock_irqrestore(&desc->lock, flags); |
332 | return ret; | |
333 | } | |
334 | EXPORT_SYMBOL(set_irq_wake); | |
335 | ||
1da177e4 LT |
336 | /* |
337 | * Internal function that tells the architecture code whether a | |
338 | * particular irq has been exclusively allocated or is available | |
339 | * for driver use. | |
340 | */ | |
341 | int can_request_irq(unsigned int irq, unsigned long irqflags) | |
342 | { | |
d3c60047 | 343 | struct irq_desc *desc = irq_to_desc(irq); |
1da177e4 LT |
344 | struct irqaction *action; |
345 | ||
7d94f7ca YL |
346 | if (!desc) |
347 | return 0; | |
348 | ||
349 | if (desc->status & IRQ_NOREQUEST) | |
1da177e4 LT |
350 | return 0; |
351 | ||
08678b08 | 352 | action = desc->action; |
1da177e4 | 353 | if (action) |
3cca53b0 | 354 | if (irqflags & action->flags & IRQF_SHARED) |
1da177e4 LT |
355 | action = NULL; |
356 | ||
357 | return !action; | |
358 | } | |
359 | ||
6a6de9ef TG |
360 | void compat_irq_chip_set_default_handler(struct irq_desc *desc) |
361 | { | |
362 | /* | |
363 | * If the architecture still has not overriden | |
364 | * the flow handler then zap the default. This | |
365 | * should catch incorrect flow-type setting. | |
366 | */ | |
367 | if (desc->handle_irq == &handle_bad_irq) | |
368 | desc->handle_irq = NULL; | |
369 | } | |
370 | ||
0c5d1eb7 | 371 | int __irq_set_trigger(struct irq_desc *desc, unsigned int irq, |
82736f4d UKK |
372 | unsigned long flags) |
373 | { | |
374 | int ret; | |
0c5d1eb7 | 375 | struct irq_chip *chip = desc->chip; |
82736f4d UKK |
376 | |
377 | if (!chip || !chip->set_type) { | |
378 | /* | |
379 | * IRQF_TRIGGER_* but the PIC does not support multiple | |
380 | * flow-types? | |
381 | */ | |
3ff68a6a | 382 | pr_debug("No set_type function for IRQ %d (%s)\n", irq, |
82736f4d UKK |
383 | chip ? (chip->name ? : "unknown") : "unknown"); |
384 | return 0; | |
385 | } | |
386 | ||
f2b662da DB |
387 | /* caller masked out all except trigger mode flags */ |
388 | ret = chip->set_type(irq, flags); | |
82736f4d UKK |
389 | |
390 | if (ret) | |
c69ad71b | 391 | pr_err("setting trigger mode %d for irq %u failed (%pF)\n", |
f2b662da | 392 | (int)flags, irq, chip->set_type); |
0c5d1eb7 | 393 | else { |
f2b662da DB |
394 | if (flags & (IRQ_TYPE_LEVEL_LOW | IRQ_TYPE_LEVEL_HIGH)) |
395 | flags |= IRQ_LEVEL; | |
0c5d1eb7 | 396 | /* note that IRQF_TRIGGER_MASK == IRQ_TYPE_SENSE_MASK */ |
f2b662da DB |
397 | desc->status &= ~(IRQ_LEVEL | IRQ_TYPE_SENSE_MASK); |
398 | desc->status |= flags; | |
0c5d1eb7 | 399 | } |
82736f4d UKK |
400 | |
401 | return ret; | |
402 | } | |
403 | ||
1da177e4 LT |
404 | /* |
405 | * Internal function to register an irqaction - typically used to | |
406 | * allocate special interrupts that are part of the architecture. | |
407 | */ | |
d3c60047 | 408 | static int |
327ec569 | 409 | __setup_irq(unsigned int irq, struct irq_desc *desc, struct irqaction *new) |
1da177e4 | 410 | { |
f17c7545 | 411 | struct irqaction *old, **old_ptr; |
8b126b77 | 412 | const char *old_name = NULL; |
1da177e4 LT |
413 | unsigned long flags; |
414 | int shared = 0; | |
82736f4d | 415 | int ret; |
1da177e4 | 416 | |
7d94f7ca | 417 | if (!desc) |
c2b5a251 MW |
418 | return -EINVAL; |
419 | ||
f1c2662c | 420 | if (desc->chip == &no_irq_chip) |
1da177e4 LT |
421 | return -ENOSYS; |
422 | /* | |
423 | * Some drivers like serial.c use request_irq() heavily, | |
424 | * so we have to be careful not to interfere with a | |
425 | * running system. | |
426 | */ | |
3cca53b0 | 427 | if (new->flags & IRQF_SAMPLE_RANDOM) { |
1da177e4 LT |
428 | /* |
429 | * This function might sleep, we want to call it first, | |
430 | * outside of the atomic block. | |
431 | * Yes, this might clear the entropy pool if the wrong | |
432 | * driver is attempted to be loaded, without actually | |
433 | * installing a new handler, but is this really a problem, | |
434 | * only the sysadmin is able to do this. | |
435 | */ | |
436 | rand_initialize_irq(irq); | |
437 | } | |
438 | ||
439 | /* | |
440 | * The following block of code has to be executed atomically | |
441 | */ | |
06fcb0c6 | 442 | spin_lock_irqsave(&desc->lock, flags); |
f17c7545 IM |
443 | old_ptr = &desc->action; |
444 | old = *old_ptr; | |
06fcb0c6 | 445 | if (old) { |
e76de9f8 TG |
446 | /* |
447 | * Can't share interrupts unless both agree to and are | |
448 | * the same type (level, edge, polarity). So both flag | |
3cca53b0 | 449 | * fields must have IRQF_SHARED set and the bits which |
e76de9f8 TG |
450 | * set the trigger type must match. |
451 | */ | |
3cca53b0 | 452 | if (!((old->flags & new->flags) & IRQF_SHARED) || |
8b126b77 AM |
453 | ((old->flags ^ new->flags) & IRQF_TRIGGER_MASK)) { |
454 | old_name = old->name; | |
f5163427 | 455 | goto mismatch; |
8b126b77 | 456 | } |
f5163427 | 457 | |
284c6680 | 458 | #if defined(CONFIG_IRQ_PER_CPU) |
f5163427 | 459 | /* All handlers must agree on per-cpuness */ |
3cca53b0 TG |
460 | if ((old->flags & IRQF_PERCPU) != |
461 | (new->flags & IRQF_PERCPU)) | |
f5163427 DS |
462 | goto mismatch; |
463 | #endif | |
1da177e4 LT |
464 | |
465 | /* add new interrupt at end of irq queue */ | |
466 | do { | |
f17c7545 IM |
467 | old_ptr = &old->next; |
468 | old = *old_ptr; | |
1da177e4 LT |
469 | } while (old); |
470 | shared = 1; | |
471 | } | |
472 | ||
1da177e4 | 473 | if (!shared) { |
6a6de9ef | 474 | irq_chip_set_defaults(desc->chip); |
e76de9f8 TG |
475 | |
476 | /* Setup the type (level, edge polarity) if configured: */ | |
3cca53b0 | 477 | if (new->flags & IRQF_TRIGGER_MASK) { |
f2b662da DB |
478 | ret = __irq_set_trigger(desc, irq, |
479 | new->flags & IRQF_TRIGGER_MASK); | |
82736f4d UKK |
480 | |
481 | if (ret) { | |
482 | spin_unlock_irqrestore(&desc->lock, flags); | |
483 | return ret; | |
484 | } | |
e76de9f8 TG |
485 | } else |
486 | compat_irq_chip_set_default_handler(desc); | |
82736f4d UKK |
487 | #if defined(CONFIG_IRQ_PER_CPU) |
488 | if (new->flags & IRQF_PERCPU) | |
489 | desc->status |= IRQ_PER_CPU; | |
490 | #endif | |
6a6de9ef | 491 | |
94d39e1f | 492 | desc->status &= ~(IRQ_AUTODETECT | IRQ_WAITING | |
1adb0850 | 493 | IRQ_INPROGRESS | IRQ_SPURIOUS_DISABLED); |
94d39e1f TG |
494 | |
495 | if (!(desc->status & IRQ_NOAUTOEN)) { | |
496 | desc->depth = 0; | |
497 | desc->status &= ~IRQ_DISABLED; | |
7e6e178a | 498 | desc->chip->startup(irq); |
e76de9f8 TG |
499 | } else |
500 | /* Undo nested disables: */ | |
501 | desc->depth = 1; | |
18404756 | 502 | |
612e3684 TG |
503 | /* Exclude IRQ from balancing if requested */ |
504 | if (new->flags & IRQF_NOBALANCING) | |
505 | desc->status |= IRQ_NO_BALANCING; | |
506 | ||
18404756 | 507 | /* Set default affinity mask once everything is setup */ |
548c8933 | 508 | setup_affinity(irq, desc); |
0c5d1eb7 DB |
509 | |
510 | } else if ((new->flags & IRQF_TRIGGER_MASK) | |
511 | && (new->flags & IRQF_TRIGGER_MASK) | |
512 | != (desc->status & IRQ_TYPE_SENSE_MASK)) { | |
513 | /* hope the handler works with the actual trigger mode... */ | |
514 | pr_warning("IRQ %d uses trigger mode %d; requested %d\n", | |
515 | irq, (int)(desc->status & IRQ_TYPE_SENSE_MASK), | |
516 | (int)(new->flags & IRQF_TRIGGER_MASK)); | |
1da177e4 | 517 | } |
82736f4d | 518 | |
f17c7545 | 519 | *old_ptr = new; |
82736f4d | 520 | |
8528b0f1 LT |
521 | /* Reset broken irq detection when installing new handler */ |
522 | desc->irq_count = 0; | |
523 | desc->irqs_unhandled = 0; | |
1adb0850 TG |
524 | |
525 | /* | |
526 | * Check whether we disabled the irq via the spurious handler | |
527 | * before. Reenable it and give it another chance. | |
528 | */ | |
529 | if (shared && (desc->status & IRQ_SPURIOUS_DISABLED)) { | |
530 | desc->status &= ~IRQ_SPURIOUS_DISABLED; | |
0a0c5168 | 531 | __enable_irq(desc, irq, false); |
1adb0850 TG |
532 | } |
533 | ||
06fcb0c6 | 534 | spin_unlock_irqrestore(&desc->lock, flags); |
1da177e4 LT |
535 | |
536 | new->irq = irq; | |
2c6927a3 | 537 | register_irq_proc(irq, desc); |
1da177e4 LT |
538 | new->dir = NULL; |
539 | register_handler_proc(irq, new); | |
540 | ||
541 | return 0; | |
f5163427 DS |
542 | |
543 | mismatch: | |
3f050447 | 544 | #ifdef CONFIG_DEBUG_SHIRQ |
3cca53b0 | 545 | if (!(new->flags & IRQF_PROBE_SHARED)) { |
e8c4b9d0 | 546 | printk(KERN_ERR "IRQ handler type mismatch for IRQ %d\n", irq); |
8b126b77 AM |
547 | if (old_name) |
548 | printk(KERN_ERR "current handler: %s\n", old_name); | |
13e87ec6 AM |
549 | dump_stack(); |
550 | } | |
3f050447 | 551 | #endif |
8b126b77 | 552 | spin_unlock_irqrestore(&desc->lock, flags); |
f5163427 | 553 | return -EBUSY; |
1da177e4 LT |
554 | } |
555 | ||
d3c60047 TG |
556 | /** |
557 | * setup_irq - setup an interrupt | |
558 | * @irq: Interrupt line to setup | |
559 | * @act: irqaction for the interrupt | |
560 | * | |
561 | * Used to statically setup interrupts in the early boot process. | |
562 | */ | |
563 | int setup_irq(unsigned int irq, struct irqaction *act) | |
564 | { | |
565 | struct irq_desc *desc = irq_to_desc(irq); | |
566 | ||
567 | return __setup_irq(irq, desc, act); | |
568 | } | |
eb53b4e8 | 569 | EXPORT_SYMBOL_GPL(setup_irq); |
d3c60047 | 570 | |
cbf94f06 MD |
571 | /* |
572 | * Internal function to unregister an irqaction - used to free | |
573 | * regular and special interrupts that are part of the architecture. | |
1da177e4 | 574 | */ |
cbf94f06 | 575 | static struct irqaction *__free_irq(unsigned int irq, void *dev_id) |
1da177e4 | 576 | { |
d3c60047 | 577 | struct irq_desc *desc = irq_to_desc(irq); |
f17c7545 | 578 | struct irqaction *action, **action_ptr; |
1da177e4 LT |
579 | unsigned long flags; |
580 | ||
ae88a23b | 581 | WARN(in_interrupt(), "Trying to free IRQ %d from IRQ context!\n", irq); |
7d94f7ca | 582 | |
7d94f7ca | 583 | if (!desc) |
f21cfb25 | 584 | return NULL; |
1da177e4 | 585 | |
06fcb0c6 | 586 | spin_lock_irqsave(&desc->lock, flags); |
ae88a23b IM |
587 | |
588 | /* | |
589 | * There can be multiple actions per IRQ descriptor, find the right | |
590 | * one based on the dev_id: | |
591 | */ | |
f17c7545 | 592 | action_ptr = &desc->action; |
1da177e4 | 593 | for (;;) { |
f17c7545 | 594 | action = *action_ptr; |
1da177e4 | 595 | |
ae88a23b IM |
596 | if (!action) { |
597 | WARN(1, "Trying to free already-free IRQ %d\n", irq); | |
598 | spin_unlock_irqrestore(&desc->lock, flags); | |
1da177e4 | 599 | |
f21cfb25 | 600 | return NULL; |
ae88a23b | 601 | } |
1da177e4 | 602 | |
8316e381 IM |
603 | if (action->dev_id == dev_id) |
604 | break; | |
f17c7545 | 605 | action_ptr = &action->next; |
ae88a23b | 606 | } |
dbce706e | 607 | |
ae88a23b | 608 | /* Found it - now remove it from the list of entries: */ |
f17c7545 | 609 | *action_ptr = action->next; |
ae88a23b IM |
610 | |
611 | /* Currently used only by UML, might disappear one day: */ | |
b77d6adc | 612 | #ifdef CONFIG_IRQ_RELEASE_METHOD |
ae88a23b IM |
613 | if (desc->chip->release) |
614 | desc->chip->release(irq, dev_id); | |
b77d6adc | 615 | #endif |
dbce706e | 616 | |
ae88a23b IM |
617 | /* If this was the last handler, shut down the IRQ line: */ |
618 | if (!desc->action) { | |
619 | desc->status |= IRQ_DISABLED; | |
620 | if (desc->chip->shutdown) | |
621 | desc->chip->shutdown(irq); | |
622 | else | |
623 | desc->chip->disable(irq); | |
624 | } | |
625 | spin_unlock_irqrestore(&desc->lock, flags); | |
626 | ||
627 | unregister_handler_proc(irq, action); | |
628 | ||
629 | /* Make sure it's not being used on another CPU: */ | |
630 | synchronize_irq(irq); | |
1da177e4 | 631 | |
70edcd77 | 632 | #ifdef CONFIG_DEBUG_SHIRQ |
ae88a23b IM |
633 | /* |
634 | * It's a shared IRQ -- the driver ought to be prepared for an IRQ | |
635 | * event to happen even now it's being freed, so let's make sure that | |
636 | * is so by doing an extra call to the handler .... | |
637 | * | |
638 | * ( We do this after actually deregistering it, to make sure that a | |
639 | * 'real' IRQ doesn't run in * parallel with our fake. ) | |
640 | */ | |
641 | if (action->flags & IRQF_SHARED) { | |
642 | local_irq_save(flags); | |
643 | action->handler(irq, dev_id); | |
644 | local_irq_restore(flags); | |
1da177e4 | 645 | } |
ae88a23b | 646 | #endif |
f21cfb25 MD |
647 | return action; |
648 | } | |
649 | ||
cbf94f06 MD |
650 | /** |
651 | * remove_irq - free an interrupt | |
652 | * @irq: Interrupt line to free | |
653 | * @act: irqaction for the interrupt | |
654 | * | |
655 | * Used to remove interrupts statically setup by the early boot process. | |
656 | */ | |
657 | void remove_irq(unsigned int irq, struct irqaction *act) | |
658 | { | |
659 | __free_irq(irq, act->dev_id); | |
660 | } | |
eb53b4e8 | 661 | EXPORT_SYMBOL_GPL(remove_irq); |
cbf94f06 | 662 | |
f21cfb25 MD |
663 | /** |
664 | * free_irq - free an interrupt allocated with request_irq | |
665 | * @irq: Interrupt line to free | |
666 | * @dev_id: Device identity to free | |
667 | * | |
668 | * Remove an interrupt handler. The handler is removed and if the | |
669 | * interrupt line is no longer in use by any driver it is disabled. | |
670 | * On a shared IRQ the caller must ensure the interrupt is disabled | |
671 | * on the card it drives before calling this function. The function | |
672 | * does not return until any executing interrupts for this IRQ | |
673 | * have completed. | |
674 | * | |
675 | * This function must not be called from interrupt context. | |
676 | */ | |
677 | void free_irq(unsigned int irq, void *dev_id) | |
678 | { | |
cbf94f06 | 679 | kfree(__free_irq(irq, dev_id)); |
1da177e4 | 680 | } |
1da177e4 LT |
681 | EXPORT_SYMBOL(free_irq); |
682 | ||
683 | /** | |
684 | * request_irq - allocate an interrupt line | |
685 | * @irq: Interrupt line to allocate | |
686 | * @handler: Function to be called when the IRQ occurs | |
687 | * @irqflags: Interrupt type flags | |
688 | * @devname: An ascii name for the claiming device | |
689 | * @dev_id: A cookie passed back to the handler function | |
690 | * | |
691 | * This call allocates interrupt resources and enables the | |
692 | * interrupt line and IRQ handling. From the point this | |
693 | * call is made your handler function may be invoked. Since | |
694 | * your handler function must clear any interrupt the board | |
695 | * raises, you must take care both to initialise your hardware | |
696 | * and to set up the interrupt handler in the right order. | |
697 | * | |
698 | * Dev_id must be globally unique. Normally the address of the | |
699 | * device data structure is used as the cookie. Since the handler | |
700 | * receives this value it makes sense to use it. | |
701 | * | |
702 | * If your interrupt is shared you must pass a non NULL dev_id | |
703 | * as this is required when freeing the interrupt. | |
704 | * | |
705 | * Flags: | |
706 | * | |
3cca53b0 TG |
707 | * IRQF_SHARED Interrupt is shared |
708 | * IRQF_DISABLED Disable local interrupts while processing | |
709 | * IRQF_SAMPLE_RANDOM The interrupt can be used for entropy | |
0c5d1eb7 | 710 | * IRQF_TRIGGER_* Specify active edge(s) or level |
1da177e4 LT |
711 | * |
712 | */ | |
da482792 | 713 | int request_irq(unsigned int irq, irq_handler_t handler, |
06fcb0c6 | 714 | unsigned long irqflags, const char *devname, void *dev_id) |
1da177e4 | 715 | { |
06fcb0c6 | 716 | struct irqaction *action; |
08678b08 | 717 | struct irq_desc *desc; |
d3c60047 | 718 | int retval; |
1da177e4 | 719 | |
470c6623 DB |
720 | /* |
721 | * handle_IRQ_event() always ignores IRQF_DISABLED except for | |
722 | * the _first_ irqaction (sigh). That can cause oopsing, but | |
723 | * the behavior is classified as "will not fix" so we need to | |
724 | * start nudging drivers away from using that idiom. | |
725 | */ | |
327ec569 IM |
726 | if ((irqflags & (IRQF_SHARED|IRQF_DISABLED)) == |
727 | (IRQF_SHARED|IRQF_DISABLED)) { | |
728 | pr_warning( | |
729 | "IRQ %d/%s: IRQF_DISABLED is not guaranteed on shared IRQs\n", | |
730 | irq, devname); | |
731 | } | |
470c6623 | 732 | |
fbb9ce95 IM |
733 | #ifdef CONFIG_LOCKDEP |
734 | /* | |
735 | * Lockdep wants atomic interrupt handlers: | |
736 | */ | |
38515e90 | 737 | irqflags |= IRQF_DISABLED; |
fbb9ce95 | 738 | #endif |
1da177e4 LT |
739 | /* |
740 | * Sanity-check: shared interrupts must pass in a real dev-ID, | |
741 | * otherwise we'll have trouble later trying to figure out | |
742 | * which interrupt is which (messes up the interrupt freeing | |
743 | * logic etc). | |
744 | */ | |
3cca53b0 | 745 | if ((irqflags & IRQF_SHARED) && !dev_id) |
1da177e4 | 746 | return -EINVAL; |
7d94f7ca | 747 | |
cb5bc832 | 748 | desc = irq_to_desc(irq); |
7d94f7ca | 749 | if (!desc) |
1da177e4 | 750 | return -EINVAL; |
7d94f7ca | 751 | |
08678b08 | 752 | if (desc->status & IRQ_NOREQUEST) |
6550c775 | 753 | return -EINVAL; |
1da177e4 LT |
754 | if (!handler) |
755 | return -EINVAL; | |
756 | ||
45535732 | 757 | action = kzalloc(sizeof(struct irqaction), GFP_KERNEL); |
1da177e4 LT |
758 | if (!action) |
759 | return -ENOMEM; | |
760 | ||
761 | action->handler = handler; | |
762 | action->flags = irqflags; | |
1da177e4 | 763 | action->name = devname; |
1da177e4 LT |
764 | action->dev_id = dev_id; |
765 | ||
d3c60047 | 766 | retval = __setup_irq(irq, desc, action); |
377bf1e4 AV |
767 | if (retval) |
768 | kfree(action); | |
769 | ||
a304e1b8 DW |
770 | #ifdef CONFIG_DEBUG_SHIRQ |
771 | if (irqflags & IRQF_SHARED) { | |
772 | /* | |
773 | * It's a shared IRQ -- the driver ought to be prepared for it | |
774 | * to happen immediately, so let's make sure.... | |
377bf1e4 AV |
775 | * We disable the irq to make sure that a 'real' IRQ doesn't |
776 | * run in parallel with our fake. | |
a304e1b8 | 777 | */ |
59845b1f | 778 | unsigned long flags; |
a304e1b8 | 779 | |
377bf1e4 | 780 | disable_irq(irq); |
59845b1f | 781 | local_irq_save(flags); |
377bf1e4 | 782 | |
59845b1f | 783 | handler(irq, dev_id); |
377bf1e4 | 784 | |
59845b1f | 785 | local_irq_restore(flags); |
377bf1e4 | 786 | enable_irq(irq); |
a304e1b8 DW |
787 | } |
788 | #endif | |
1da177e4 LT |
789 | return retval; |
790 | } | |
1da177e4 | 791 | EXPORT_SYMBOL(request_irq); |