Commit | Line | Data |
---|---|---|
1da177e4 LT |
1 | /* |
2 | * linux/kernel/irq/handle.c | |
3 | * | |
a34db9b2 IM |
4 | * Copyright (C) 1992, 1998-2006 Linus Torvalds, Ingo Molnar |
5 | * Copyright (C) 2005-2006, Thomas Gleixner, Russell King | |
1da177e4 LT |
6 | * |
7 | * This file contains the core interrupt handling code. | |
a34db9b2 IM |
8 | * |
9 | * Detailed information is available in Documentation/DocBook/genericirq | |
10 | * | |
1da177e4 LT |
11 | */ |
12 | ||
13 | #include <linux/irq.h> | |
14 | #include <linux/module.h> | |
15 | #include <linux/random.h> | |
16 | #include <linux/interrupt.h> | |
17 | #include <linux/kernel_stat.h> | |
18 | ||
19 | #include "internals.h" | |
20 | ||
08678b08 YL |
21 | /* |
22 | * lockdep: we want to handle all irq_desc locks as a single lock-class: | |
23 | */ | |
24 | static struct lock_class_key irq_desc_lock_class; | |
08678b08 | 25 | |
6a6de9ef TG |
26 | /** |
27 | * handle_bad_irq - handle spurious and unhandled irqs | |
43a1dd50 HK |
28 | * @irq: the interrupt number |
29 | * @desc: description of the interrupt | |
43a1dd50 HK |
30 | * |
31 | * Handles spurious and unhandled IRQ's. It also prints a debugmessage. | |
6a6de9ef | 32 | */ |
7ad5b3a5 | 33 | void |
7d12e780 | 34 | handle_bad_irq(unsigned int irq, struct irq_desc *desc) |
6a6de9ef | 35 | { |
43f77759 | 36 | print_irq_desc(irq, desc); |
7f95ec9e | 37 | kstat_irqs_this_cpu(desc)++; |
6a6de9ef TG |
38 | ack_bad_irq(irq); |
39 | } | |
40 | ||
1da177e4 LT |
41 | /* |
42 | * Linux has a controller-independent interrupt architecture. | |
43 | * Every controller has a 'controller-template', that is used | |
44 | * by the main code to do the right thing. Each driver-visible | |
06fcb0c6 | 45 | * interrupt source is transparently wired to the appropriate |
1da177e4 LT |
46 | * controller. Thus drivers need not be aware of the |
47 | * interrupt-controller. | |
48 | * | |
49 | * The code is designed to be easily extended with new/different | |
50 | * interrupt controllers, without having to do assembly magic or | |
51 | * having to touch the generic code. | |
52 | * | |
53 | * Controller mappings for all interrupt sources: | |
54 | */ | |
85c0f909 | 55 | int nr_irqs = NR_IRQS; |
fa42d10d | 56 | EXPORT_SYMBOL_GPL(nr_irqs); |
d60458b2 YL |
57 | |
58 | #ifdef CONFIG_HAVE_DYN_ARRAY | |
08678b08 YL |
59 | static struct irq_desc irq_desc_init = { |
60 | .irq = -1U, | |
d60458b2 YL |
61 | .status = IRQ_DISABLED, |
62 | .chip = &no_irq_chip, | |
63 | .handle_irq = handle_bad_irq, | |
64 | .depth = 1, | |
65 | .lock = __SPIN_LOCK_UNLOCKED(irq_desc_init.lock), | |
66 | #ifdef CONFIG_SMP | |
67 | .affinity = CPU_MASK_ALL | |
68 | #endif | |
69 | }; | |
70 | ||
08678b08 YL |
71 | |
72 | static void init_one_irq_desc(struct irq_desc *desc) | |
73 | { | |
74 | memcpy(desc, &irq_desc_init, sizeof(struct irq_desc)); | |
08678b08 | 75 | lockdep_set_class(&desc->lock, &irq_desc_lock_class); |
08678b08 YL |
76 | } |
77 | ||
7f95ec9e YL |
78 | extern int after_bootmem; |
79 | extern void *__alloc_bootmem_nopanic(unsigned long size, | |
80 | unsigned long align, | |
81 | unsigned long goal); | |
08678b08 | 82 | |
7f95ec9e | 83 | static void init_kstat_irqs(struct irq_desc *desc, int nr_desc, int nr) |
08678b08 | 84 | { |
7f95ec9e YL |
85 | unsigned long bytes, total_bytes; |
86 | char *ptr; | |
87 | int i; | |
88 | unsigned long phys; | |
89 | ||
90 | /* Compute how many bytes we need per irq and allocate them */ | |
91 | bytes = nr * sizeof(unsigned int); | |
92 | total_bytes = bytes * nr_desc; | |
93 | if (after_bootmem) | |
94 | ptr = kzalloc(total_bytes, GFP_ATOMIC); | |
95 | else | |
96 | ptr = __alloc_bootmem_nopanic(total_bytes, PAGE_SIZE, 0); | |
97 | ||
98 | if (!ptr) | |
99 | panic(" can not allocate kstat_irqs\n"); | |
100 | ||
101 | phys = __pa(ptr); | |
102 | printk(KERN_DEBUG "kstat_irqs ==> [%#lx - %#lx]\n", phys, phys + total_bytes); | |
103 | ||
104 | for (i = 0; i < nr_desc; i++) { | |
105 | desc[i].kstat_irqs = (unsigned int *)ptr; | |
106 | ptr += bytes; | |
107 | } | |
08678b08 YL |
108 | } |
109 | ||
e89eb438 YL |
110 | /* |
111 | * Protect the sparse_irqs_free freelist: | |
112 | */ | |
113 | static DEFINE_SPINLOCK(sparse_irq_lock); | |
114 | ||
67fb283e YL |
115 | #ifdef CONFIG_HAVE_SPARSE_IRQ |
116 | static struct irq_desc *sparse_irqs_free; | |
117 | struct irq_desc *sparse_irqs; | |
118 | #endif | |
119 | ||
d60458b2 YL |
120 | static void __init init_work(void *data) |
121 | { | |
122 | struct dyn_array *da = data; | |
123 | int i; | |
124 | struct irq_desc *desc; | |
125 | ||
126 | desc = *da->name; | |
127 | ||
7f95ec9e | 128 | for (i = 0; i < *da->nr; i++) { |
08678b08 | 129 | init_one_irq_desc(&desc[i]); |
7f95ec9e YL |
130 | #ifndef CONFIG_HAVE_SPARSE_IRQ |
131 | desc[i].irq = i; | |
132 | #endif | |
133 | } | |
08678b08 | 134 | |
67fb283e YL |
135 | /* init kstat_irqs, nr_cpu_ids is ready already */ |
136 | init_kstat_irqs(desc, *da->nr, nr_cpu_ids); | |
137 | ||
7f95ec9e | 138 | #ifdef CONFIG_HAVE_SPARSE_IRQ |
08678b08 YL |
139 | for (i = 1; i < *da->nr; i++) |
140 | desc[i-1].next = &desc[i]; | |
7f95ec9e | 141 | |
67fb283e YL |
142 | sparse_irqs_free = sparse_irqs; |
143 | sparse_irqs = NULL; | |
144 | #endif | |
d60458b2 YL |
145 | } |
146 | ||
7f95ec9e YL |
147 | #ifdef CONFIG_HAVE_SPARSE_IRQ |
148 | static int nr_irq_desc = 32; | |
149 | ||
150 | static int __init parse_nr_irq_desc(char *arg) | |
151 | { | |
152 | if (arg) | |
153 | nr_irq_desc = simple_strtoul(arg, NULL, 0); | |
154 | return 0; | |
155 | } | |
156 | ||
157 | early_param("nr_irq_desc", parse_nr_irq_desc); | |
158 | ||
08678b08 YL |
159 | DEFINE_DYN_ARRAY(sparse_irqs, sizeof(struct irq_desc), nr_irq_desc, PAGE_SIZE, init_work); |
160 | ||
cb5bc832 | 161 | struct irq_desc *irq_to_desc(unsigned int irq) |
9059d8fa YL |
162 | { |
163 | struct irq_desc *desc; | |
164 | ||
67fb283e | 165 | desc = sparse_irqs; |
9059d8fa YL |
166 | while (desc) { |
167 | if (desc->irq == irq) | |
168 | return desc; | |
169 | ||
9059d8fa YL |
170 | desc = desc->next; |
171 | } | |
172 | return NULL; | |
173 | } | |
e89eb438 | 174 | |
cb5bc832 | 175 | struct irq_desc *irq_to_desc_alloc(unsigned int irq) |
08678b08 YL |
176 | { |
177 | struct irq_desc *desc, *desc_pri; | |
e89eb438 | 178 | unsigned long flags; |
08678b08 | 179 | int count = 0; |
e89eb438 | 180 | int i; |
08678b08 | 181 | |
67fb283e | 182 | desc_pri = desc = sparse_irqs; |
08678b08 YL |
183 | while (desc) { |
184 | if (desc->irq == irq) | |
185 | return desc; | |
186 | ||
08678b08 YL |
187 | desc_pri = desc; |
188 | desc = desc->next; | |
189 | count++; | |
190 | } | |
191 | ||
e89eb438 | 192 | spin_lock_irqsave(&sparse_irq_lock, flags); |
08678b08 YL |
193 | /* |
194 | * we run out of pre-allocate ones, allocate more | |
195 | */ | |
67fb283e YL |
196 | if (!sparse_irqs_free) { |
197 | unsigned long phys; | |
198 | unsigned long total_bytes; | |
08678b08 | 199 | |
67fb283e | 200 | printk(KERN_DEBUG "try to get more irq_desc %d\n", nr_irq_desc); |
08678b08 | 201 | |
67fb283e YL |
202 | total_bytes = sizeof(struct irq_desc) * nr_irq_desc; |
203 | if (after_bootmem) | |
204 | desc = kzalloc(total_bytes, GFP_ATOMIC); | |
205 | else | |
206 | desc = __alloc_bootmem_nopanic(total_bytes, PAGE_SIZE, 0); | |
08678b08 | 207 | |
67fb283e YL |
208 | if (!desc) |
209 | panic("please boot with nr_irq_desc= %d\n", count * 2); | |
7f95ec9e | 210 | |
67fb283e YL |
211 | phys = __pa(desc); |
212 | printk(KERN_DEBUG "irq_desc ==> [%#lx - %#lx]\n", phys, phys + total_bytes); | |
08678b08 | 213 | |
67fb283e YL |
214 | for (i = 0; i < nr_irq_desc; i++) |
215 | init_one_irq_desc(&desc[i]); | |
08678b08 | 216 | |
67fb283e YL |
217 | for (i = 1; i < nr_irq_desc; i++) |
218 | desc[i-1].next = &desc[i]; | |
7f95ec9e | 219 | |
67fb283e YL |
220 | /* init kstat_irqs, nr_cpu_ids is ready already */ |
221 | init_kstat_irqs(desc, nr_irq_desc, nr_cpu_ids); | |
08678b08 | 222 | |
67fb283e YL |
223 | sparse_irqs_free = desc; |
224 | } | |
225 | ||
226 | desc = sparse_irqs_free; | |
227 | sparse_irqs_free = sparse_irqs_free->next; | |
228 | desc->next = NULL; | |
229 | if (desc_pri) | |
230 | desc_pri->next = desc; | |
231 | else | |
232 | sparse_irqs = desc; | |
233 | desc->irq = irq; | |
e89eb438 YL |
234 | |
235 | spin_unlock_irqrestore(&sparse_irq_lock, flags); | |
236 | ||
67fb283e YL |
237 | printk(KERN_DEBUG "found new irq_desc for irq %d\n", desc->irq); |
238 | #ifdef CONFIG_HAVE_SPARSE_IRQ_DEBUG | |
239 | { | |
240 | /* dump the results */ | |
241 | struct irq_desc *desc; | |
242 | unsigned long phys; | |
243 | unsigned long bytes = sizeof(struct irq_desc); | |
244 | unsigned int irqx; | |
245 | ||
246 | printk(KERN_DEBUG "=========================== %d\n", irq); | |
247 | printk(KERN_DEBUG "irq_desc dump after get that for %d\n", irq); | |
248 | for_each_irq_desc(irqx, desc) { | |
249 | phys = __pa(desc); | |
250 | printk(KERN_DEBUG "irq_desc %d ==> [%#lx - %#lx]\n", irqx, phys, phys + bytes); | |
251 | } | |
252 | printk(KERN_DEBUG "===========================\n"); | |
253 | } | |
254 | #endif | |
08678b08 YL |
255 | return desc; |
256 | } | |
257 | #else | |
9059d8fa | 258 | struct irq_desc *irq_desc; |
d60458b2 YL |
259 | DEFINE_DYN_ARRAY(irq_desc, sizeof(struct irq_desc), nr_irqs, PAGE_SIZE, init_work); |
260 | ||
08678b08 YL |
261 | #endif |
262 | ||
d60458b2 YL |
263 | #else |
264 | ||
e729aa16 | 265 | struct irq_desc irq_desc[NR_IRQS] __cacheline_aligned_in_smp = { |
1da177e4 | 266 | [0 ... NR_IRQS-1] = { |
4f167fb4 | 267 | .status = IRQ_DISABLED, |
f1c2662c | 268 | .chip = &no_irq_chip, |
7a55713a | 269 | .handle_irq = handle_bad_irq, |
94d39e1f | 270 | .depth = 1, |
08678b08 | 271 | .lock = __SPIN_LOCK_UNLOCKED(sparse_irqs->lock), |
a53da52f IM |
272 | #ifdef CONFIG_SMP |
273 | .affinity = CPU_MASK_ALL | |
274 | #endif | |
1da177e4 LT |
275 | } |
276 | }; | |
08678b08 YL |
277 | |
278 | #endif | |
279 | ||
280 | #ifndef CONFIG_HAVE_SPARSE_IRQ | |
281 | struct irq_desc *irq_to_desc(unsigned int irq) | |
282 | { | |
283 | if (irq < nr_irqs) | |
284 | return &irq_desc[irq]; | |
285 | ||
286 | return NULL; | |
287 | } | |
cb5bc832 | 288 | struct irq_desc *irq_to_desc_alloc(unsigned int irq) |
9059d8fa YL |
289 | { |
290 | return irq_to_desc(irq); | |
291 | } | |
d60458b2 | 292 | #endif |
1da177e4 LT |
293 | |
294 | /* | |
77a5afec IM |
295 | * What should we do if we get a hw irq event on an illegal vector? |
296 | * Each architecture has to answer this themself. | |
1da177e4 | 297 | */ |
77a5afec | 298 | static void ack_bad(unsigned int irq) |
1da177e4 | 299 | { |
08678b08 YL |
300 | struct irq_desc *desc; |
301 | ||
302 | desc = irq_to_desc(irq); | |
303 | print_irq_desc(irq, desc); | |
1da177e4 LT |
304 | ack_bad_irq(irq); |
305 | } | |
306 | ||
77a5afec IM |
307 | /* |
308 | * NOP functions | |
309 | */ | |
310 | static void noop(unsigned int irq) | |
311 | { | |
312 | } | |
313 | ||
314 | static unsigned int noop_ret(unsigned int irq) | |
315 | { | |
316 | return 0; | |
317 | } | |
318 | ||
319 | /* | |
320 | * Generic no controller implementation | |
321 | */ | |
f1c2662c IM |
322 | struct irq_chip no_irq_chip = { |
323 | .name = "none", | |
77a5afec IM |
324 | .startup = noop_ret, |
325 | .shutdown = noop, | |
326 | .enable = noop, | |
327 | .disable = noop, | |
328 | .ack = ack_bad, | |
329 | .end = noop, | |
1da177e4 LT |
330 | }; |
331 | ||
f8b5473f TG |
332 | /* |
333 | * Generic dummy implementation which can be used for | |
334 | * real dumb interrupt sources | |
335 | */ | |
336 | struct irq_chip dummy_irq_chip = { | |
337 | .name = "dummy", | |
338 | .startup = noop_ret, | |
339 | .shutdown = noop, | |
340 | .enable = noop, | |
341 | .disable = noop, | |
342 | .ack = noop, | |
343 | .mask = noop, | |
344 | .unmask = noop, | |
345 | .end = noop, | |
346 | }; | |
347 | ||
1da177e4 LT |
348 | /* |
349 | * Special, empty irq handler: | |
350 | */ | |
7d12e780 | 351 | irqreturn_t no_action(int cpl, void *dev_id) |
1da177e4 LT |
352 | { |
353 | return IRQ_NONE; | |
354 | } | |
355 | ||
8d28bc75 IM |
356 | /** |
357 | * handle_IRQ_event - irq action chain handler | |
358 | * @irq: the interrupt number | |
8d28bc75 IM |
359 | * @action: the interrupt action chain for this irq |
360 | * | |
361 | * Handles the action chain of an irq event | |
1da177e4 | 362 | */ |
7d12e780 | 363 | irqreturn_t handle_IRQ_event(unsigned int irq, struct irqaction *action) |
1da177e4 | 364 | { |
908dcecd JB |
365 | irqreturn_t ret, retval = IRQ_NONE; |
366 | unsigned int status = 0; | |
1da177e4 | 367 | |
3cca53b0 | 368 | if (!(action->flags & IRQF_DISABLED)) |
366c7f55 | 369 | local_irq_enable_in_hardirq(); |
1da177e4 LT |
370 | |
371 | do { | |
7d12e780 | 372 | ret = action->handler(irq, action->dev_id); |
1da177e4 LT |
373 | if (ret == IRQ_HANDLED) |
374 | status |= action->flags; | |
375 | retval |= ret; | |
376 | action = action->next; | |
377 | } while (action); | |
378 | ||
3cca53b0 | 379 | if (status & IRQF_SAMPLE_RANDOM) |
1da177e4 LT |
380 | add_interrupt_randomness(irq); |
381 | local_irq_disable(); | |
382 | ||
383 | return retval; | |
384 | } | |
385 | ||
af8c65b5 | 386 | #ifndef CONFIG_GENERIC_HARDIRQS_NO__DO_IRQ |
8d28bc75 IM |
387 | /** |
388 | * __do_IRQ - original all in one highlevel IRQ handler | |
389 | * @irq: the interrupt number | |
8d28bc75 IM |
390 | * |
391 | * __do_IRQ handles all normal device IRQ's (the special | |
1da177e4 LT |
392 | * SMP cross-CPU interrupts have their own specific |
393 | * handlers). | |
8d28bc75 IM |
394 | * |
395 | * This is the original x86 implementation which is used for every | |
396 | * interrupt type. | |
1da177e4 | 397 | */ |
7ad5b3a5 | 398 | unsigned int __do_IRQ(unsigned int irq) |
1da177e4 | 399 | { |
08678b08 | 400 | struct irq_desc *desc = irq_to_desc(irq); |
06fcb0c6 | 401 | struct irqaction *action; |
1da177e4 LT |
402 | unsigned int status; |
403 | ||
7f95ec9e | 404 | kstat_irqs_this_cpu(desc)++; |
f26fdd59 | 405 | if (CHECK_IRQ_PER_CPU(desc->status)) { |
1da177e4 LT |
406 | irqreturn_t action_ret; |
407 | ||
408 | /* | |
409 | * No locking required for CPU-local interrupts: | |
410 | */ | |
d1bef4ed IM |
411 | if (desc->chip->ack) |
412 | desc->chip->ack(irq); | |
c642b839 RA |
413 | if (likely(!(desc->status & IRQ_DISABLED))) { |
414 | action_ret = handle_IRQ_event(irq, desc->action); | |
415 | if (!noirqdebug) | |
416 | note_interrupt(irq, desc, action_ret); | |
417 | } | |
d1bef4ed | 418 | desc->chip->end(irq); |
1da177e4 LT |
419 | return 1; |
420 | } | |
421 | ||
422 | spin_lock(&desc->lock); | |
d1bef4ed IM |
423 | if (desc->chip->ack) |
424 | desc->chip->ack(irq); | |
1da177e4 LT |
425 | /* |
426 | * REPLAY is when Linux resends an IRQ that was dropped earlier | |
427 | * WAITING is used by probe to mark irqs that are being tested | |
428 | */ | |
429 | status = desc->status & ~(IRQ_REPLAY | IRQ_WAITING); | |
430 | status |= IRQ_PENDING; /* we _want_ to handle it */ | |
431 | ||
432 | /* | |
433 | * If the IRQ is disabled for whatever reason, we cannot | |
434 | * use the action we have. | |
435 | */ | |
436 | action = NULL; | |
437 | if (likely(!(status & (IRQ_DISABLED | IRQ_INPROGRESS)))) { | |
438 | action = desc->action; | |
439 | status &= ~IRQ_PENDING; /* we commit to handling */ | |
440 | status |= IRQ_INPROGRESS; /* we are handling it */ | |
441 | } | |
442 | desc->status = status; | |
443 | ||
444 | /* | |
445 | * If there is no IRQ handler or it was disabled, exit early. | |
446 | * Since we set PENDING, if another processor is handling | |
447 | * a different instance of this same irq, the other processor | |
448 | * will take care of it. | |
449 | */ | |
450 | if (unlikely(!action)) | |
451 | goto out; | |
452 | ||
453 | /* | |
454 | * Edge triggered interrupts need to remember | |
455 | * pending events. | |
456 | * This applies to any hw interrupts that allow a second | |
457 | * instance of the same irq to arrive while we are in do_IRQ | |
458 | * or in the handler. But the code here only handles the _second_ | |
459 | * instance of the irq, not the third or fourth. So it is mostly | |
460 | * useful for irq hardware that does not mask cleanly in an | |
461 | * SMP environment. | |
462 | */ | |
463 | for (;;) { | |
464 | irqreturn_t action_ret; | |
465 | ||
466 | spin_unlock(&desc->lock); | |
467 | ||
7d12e780 | 468 | action_ret = handle_IRQ_event(irq, action); |
1da177e4 | 469 | if (!noirqdebug) |
7d12e780 | 470 | note_interrupt(irq, desc, action_ret); |
b42172fc LT |
471 | |
472 | spin_lock(&desc->lock); | |
1da177e4 LT |
473 | if (likely(!(desc->status & IRQ_PENDING))) |
474 | break; | |
475 | desc->status &= ~IRQ_PENDING; | |
476 | } | |
477 | desc->status &= ~IRQ_INPROGRESS; | |
478 | ||
479 | out: | |
480 | /* | |
481 | * The ->end() handler has to deal with interrupts which got | |
482 | * disabled while the handler was running. | |
483 | */ | |
d1bef4ed | 484 | desc->chip->end(irq); |
1da177e4 LT |
485 | spin_unlock(&desc->lock); |
486 | ||
487 | return 1; | |
488 | } | |
af8c65b5 | 489 | #endif |
1da177e4 | 490 | |
243c7621 | 491 | |
08678b08 | 492 | #ifdef CONFIG_TRACE_IRQFLAGS |
243c7621 IM |
493 | void early_init_irq_lock_class(void) |
494 | { | |
08678b08 | 495 | #ifndef CONFIG_HAVE_DYN_ARRAY |
243c7621 IM |
496 | int i; |
497 | ||
85c0f909 | 498 | for (i = 0; i < nr_irqs; i++) |
243c7621 | 499 | lockdep_set_class(&irq_desc[i].lock, &irq_desc_lock_class); |
08678b08 | 500 | #endif |
243c7621 | 501 | } |
243c7621 | 502 | #endif |
08678b08 | 503 | |
7f95ec9e YL |
504 | unsigned int kstat_irqs_cpu(unsigned int irq, int cpu) |
505 | { | |
506 | struct irq_desc *desc = irq_to_desc(irq); | |
507 | return desc->kstat_irqs[cpu]; | |
508 | } | |
509 | EXPORT_SYMBOL(kstat_irqs_cpu); | |
510 |