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1 | /* |
2 | * linux/kernel/irq/chip.c | |
3 | * | |
4 | * Copyright (C) 1992, 1998-2006 Linus Torvalds, Ingo Molnar | |
5 | * Copyright (C) 2005-2006, Thomas Gleixner, Russell King | |
6 | * | |
7 | * This file contains the core interrupt handling code, for irq-chip | |
8 | * based architectures. | |
9 | * | |
10 | * Detailed information is available in Documentation/DocBook/genericirq | |
11 | */ | |
12 | ||
13 | #include <linux/irq.h> | |
14 | #include <linux/module.h> | |
15 | #include <linux/interrupt.h> | |
16 | #include <linux/kernel_stat.h> | |
17 | ||
18 | #include "internals.h" | |
19 | ||
20 | /** | |
21 | * set_irq_chip - set the irq chip for an irq | |
22 | * @irq: irq number | |
23 | * @chip: pointer to irq chip description structure | |
24 | */ | |
25 | int set_irq_chip(unsigned int irq, struct irq_chip *chip) | |
26 | { | |
27 | struct irq_desc *desc; | |
28 | unsigned long flags; | |
29 | ||
30 | if (irq >= NR_IRQS) { | |
31 | printk(KERN_ERR "Trying to install chip for IRQ%d\n", irq); | |
32 | WARN_ON(1); | |
33 | return -EINVAL; | |
34 | } | |
35 | ||
36 | if (!chip) | |
37 | chip = &no_irq_chip; | |
38 | ||
39 | desc = irq_desc + irq; | |
40 | spin_lock_irqsave(&desc->lock, flags); | |
41 | irq_chip_set_defaults(chip); | |
42 | desc->chip = chip; | |
43 | /* | |
44 | * For compatibility only: | |
45 | */ | |
46 | desc->chip = chip; | |
47 | spin_unlock_irqrestore(&desc->lock, flags); | |
48 | ||
49 | return 0; | |
50 | } | |
51 | EXPORT_SYMBOL(set_irq_chip); | |
52 | ||
53 | /** | |
54 | * set_irq_type - set the irq type for an irq | |
55 | * @irq: irq number | |
56 | * @type: interrupt type - see include/linux/interrupt.h | |
57 | */ | |
58 | int set_irq_type(unsigned int irq, unsigned int type) | |
59 | { | |
60 | struct irq_desc *desc; | |
61 | unsigned long flags; | |
62 | int ret = -ENXIO; | |
63 | ||
64 | if (irq >= NR_IRQS) { | |
65 | printk(KERN_ERR "Trying to set irq type for IRQ%d\n", irq); | |
66 | return -ENODEV; | |
67 | } | |
68 | ||
69 | desc = irq_desc + irq; | |
70 | if (desc->chip->set_type) { | |
71 | spin_lock_irqsave(&desc->lock, flags); | |
72 | ret = desc->chip->set_type(irq, type); | |
73 | spin_unlock_irqrestore(&desc->lock, flags); | |
74 | } | |
75 | return ret; | |
76 | } | |
77 | EXPORT_SYMBOL(set_irq_type); | |
78 | ||
79 | /** | |
80 | * set_irq_data - set irq type data for an irq | |
81 | * @irq: Interrupt number | |
82 | * @data: Pointer to interrupt specific data | |
83 | * | |
84 | * Set the hardware irq controller data for an irq | |
85 | */ | |
86 | int set_irq_data(unsigned int irq, void *data) | |
87 | { | |
88 | struct irq_desc *desc; | |
89 | unsigned long flags; | |
90 | ||
91 | if (irq >= NR_IRQS) { | |
92 | printk(KERN_ERR | |
93 | "Trying to install controller data for IRQ%d\n", irq); | |
94 | return -EINVAL; | |
95 | } | |
96 | ||
97 | desc = irq_desc + irq; | |
98 | spin_lock_irqsave(&desc->lock, flags); | |
99 | desc->handler_data = data; | |
100 | spin_unlock_irqrestore(&desc->lock, flags); | |
101 | return 0; | |
102 | } | |
103 | EXPORT_SYMBOL(set_irq_data); | |
104 | ||
105 | /** | |
106 | * set_irq_chip_data - set irq chip data for an irq | |
107 | * @irq: Interrupt number | |
108 | * @data: Pointer to chip specific data | |
109 | * | |
110 | * Set the hardware irq chip data for an irq | |
111 | */ | |
112 | int set_irq_chip_data(unsigned int irq, void *data) | |
113 | { | |
114 | struct irq_desc *desc = irq_desc + irq; | |
115 | unsigned long flags; | |
116 | ||
117 | if (irq >= NR_IRQS || !desc->chip) { | |
118 | printk(KERN_ERR "BUG: bad set_irq_chip_data(IRQ#%d)\n", irq); | |
119 | return -EINVAL; | |
120 | } | |
121 | ||
122 | spin_lock_irqsave(&desc->lock, flags); | |
123 | desc->chip_data = data; | |
124 | spin_unlock_irqrestore(&desc->lock, flags); | |
125 | ||
126 | return 0; | |
127 | } | |
128 | EXPORT_SYMBOL(set_irq_chip_data); | |
129 | ||
130 | /* | |
131 | * default enable function | |
132 | */ | |
133 | static void default_enable(unsigned int irq) | |
134 | { | |
135 | struct irq_desc *desc = irq_desc + irq; | |
136 | ||
137 | desc->chip->unmask(irq); | |
138 | desc->status &= ~IRQ_MASKED; | |
139 | } | |
140 | ||
141 | /* | |
142 | * default disable function | |
143 | */ | |
144 | static void default_disable(unsigned int irq) | |
145 | { | |
146 | struct irq_desc *desc = irq_desc + irq; | |
147 | ||
148 | if (!(desc->status & IRQ_DELAYED_DISABLE)) | |
149 | irq_desc[irq].chip->mask(irq); | |
150 | } | |
151 | ||
152 | /* | |
153 | * default startup function | |
154 | */ | |
155 | static unsigned int default_startup(unsigned int irq) | |
156 | { | |
157 | irq_desc[irq].chip->enable(irq); | |
158 | ||
159 | return 0; | |
160 | } | |
161 | ||
162 | /* | |
163 | * Fixup enable/disable function pointers | |
164 | */ | |
165 | void irq_chip_set_defaults(struct irq_chip *chip) | |
166 | { | |
167 | if (!chip->enable) | |
168 | chip->enable = default_enable; | |
169 | if (!chip->disable) | |
170 | chip->disable = default_disable; | |
171 | if (!chip->startup) | |
172 | chip->startup = default_startup; | |
173 | if (!chip->shutdown) | |
174 | chip->shutdown = chip->disable; | |
175 | if (!chip->name) | |
176 | chip->name = chip->typename; | |
177 | } | |
178 | ||
179 | static inline void mask_ack_irq(struct irq_desc *desc, int irq) | |
180 | { | |
181 | if (desc->chip->mask_ack) | |
182 | desc->chip->mask_ack(irq); | |
183 | else { | |
184 | desc->chip->mask(irq); | |
185 | desc->chip->ack(irq); | |
186 | } | |
187 | } | |
188 | ||
189 | /** | |
190 | * handle_simple_irq - Simple and software-decoded IRQs. | |
191 | * @irq: the interrupt number | |
192 | * @desc: the interrupt description structure for this irq | |
193 | * @regs: pointer to a register structure | |
194 | * | |
195 | * Simple interrupts are either sent from a demultiplexing interrupt | |
196 | * handler or come from hardware, where no interrupt hardware control | |
197 | * is necessary. | |
198 | * | |
199 | * Note: The caller is expected to handle the ack, clear, mask and | |
200 | * unmask issues if necessary. | |
201 | */ | |
202 | void fastcall | |
203 | handle_simple_irq(unsigned int irq, struct irq_desc *desc, struct pt_regs *regs) | |
204 | { | |
205 | struct irqaction *action; | |
206 | irqreturn_t action_ret; | |
207 | const unsigned int cpu = smp_processor_id(); | |
208 | ||
209 | spin_lock(&desc->lock); | |
210 | ||
211 | if (unlikely(desc->status & IRQ_INPROGRESS)) | |
212 | goto out_unlock; | |
213 | desc->status &= ~(IRQ_REPLAY | IRQ_WAITING); | |
214 | kstat_cpu(cpu).irqs[irq]++; | |
215 | ||
216 | action = desc->action; | |
217 | if (unlikely(!action || (desc->status & IRQ_DISABLED))) | |
218 | goto out_unlock; | |
219 | ||
220 | desc->status |= IRQ_INPROGRESS; | |
221 | spin_unlock(&desc->lock); | |
222 | ||
223 | action_ret = handle_IRQ_event(irq, regs, action); | |
224 | if (!noirqdebug) | |
225 | note_interrupt(irq, desc, action_ret, regs); | |
226 | ||
227 | spin_lock(&desc->lock); | |
228 | desc->status &= ~IRQ_INPROGRESS; | |
229 | out_unlock: | |
230 | spin_unlock(&desc->lock); | |
231 | } | |
232 | ||
233 | /** | |
234 | * handle_level_irq - Level type irq handler | |
235 | * @irq: the interrupt number | |
236 | * @desc: the interrupt description structure for this irq | |
237 | * @regs: pointer to a register structure | |
238 | * | |
239 | * Level type interrupts are active as long as the hardware line has | |
240 | * the active level. This may require to mask the interrupt and unmask | |
241 | * it after the associated handler has acknowledged the device, so the | |
242 | * interrupt line is back to inactive. | |
243 | */ | |
244 | void fastcall | |
245 | handle_level_irq(unsigned int irq, struct irq_desc *desc, struct pt_regs *regs) | |
246 | { | |
247 | unsigned int cpu = smp_processor_id(); | |
248 | struct irqaction *action; | |
249 | irqreturn_t action_ret; | |
250 | ||
251 | spin_lock(&desc->lock); | |
252 | mask_ack_irq(desc, irq); | |
253 | ||
254 | if (unlikely(desc->status & IRQ_INPROGRESS)) | |
255 | goto out; | |
256 | desc->status &= ~(IRQ_REPLAY | IRQ_WAITING); | |
257 | kstat_cpu(cpu).irqs[irq]++; | |
258 | ||
259 | /* | |
260 | * If its disabled or no action available | |
261 | * keep it masked and get out of here | |
262 | */ | |
263 | action = desc->action; | |
264 | if (unlikely(!action || (desc->status & IRQ_DISABLED))) | |
265 | goto out; | |
266 | ||
267 | desc->status |= IRQ_INPROGRESS; | |
268 | spin_unlock(&desc->lock); | |
269 | ||
270 | action_ret = handle_IRQ_event(irq, regs, action); | |
271 | if (!noirqdebug) | |
272 | note_interrupt(irq, desc, action_ret, regs); | |
273 | ||
274 | spin_lock(&desc->lock); | |
275 | desc->status &= ~IRQ_INPROGRESS; | |
276 | out: | |
277 | if (!(desc->status & IRQ_DISABLED) && desc->chip->unmask) | |
278 | desc->chip->unmask(irq); | |
279 | spin_unlock(&desc->lock); | |
280 | } | |
281 | ||
282 | /** | |
283 | * handle_fastack_irq - irq handler for transparent controllers | |
284 | * @irq: the interrupt number | |
285 | * @desc: the interrupt description structure for this irq | |
286 | * @regs: pointer to a register structure | |
287 | * | |
288 | * Only a single callback will be issued to the chip: an ->ack() | |
289 | * call when the interrupt has been serviced. This enables support | |
290 | * for modern forms of interrupt handlers, which handle the flow | |
291 | * details in hardware, transparently. | |
292 | */ | |
293 | void fastcall | |
294 | handle_fastack_irq(unsigned int irq, struct irq_desc *desc, | |
295 | struct pt_regs *regs) | |
296 | { | |
297 | unsigned int cpu = smp_processor_id(); | |
298 | struct irqaction *action; | |
299 | irqreturn_t action_ret; | |
300 | ||
301 | spin_lock(&desc->lock); | |
302 | ||
303 | if (unlikely(desc->status & IRQ_INPROGRESS)) | |
304 | goto out; | |
305 | ||
306 | desc->status &= ~(IRQ_REPLAY | IRQ_WAITING); | |
307 | kstat_cpu(cpu).irqs[irq]++; | |
308 | ||
309 | /* | |
310 | * If its disabled or no action available | |
311 | * keep it masked and get out of here | |
312 | */ | |
313 | action = desc->action; | |
314 | if (unlikely(!action || (desc->status & IRQ_DISABLED))) | |
315 | goto out; | |
316 | ||
317 | desc->status |= IRQ_INPROGRESS; | |
318 | spin_unlock(&desc->lock); | |
319 | ||
320 | action_ret = handle_IRQ_event(irq, regs, action); | |
321 | if (!noirqdebug) | |
322 | note_interrupt(irq, desc, action_ret, regs); | |
323 | ||
324 | spin_lock(&desc->lock); | |
325 | desc->status &= ~IRQ_INPROGRESS; | |
326 | out: | |
327 | if (!(desc->status & IRQ_DISABLED)) | |
328 | desc->chip->ack(irq); | |
329 | else | |
330 | desc->chip->mask(irq); | |
331 | ||
332 | spin_unlock(&desc->lock); | |
333 | } | |
334 | ||
335 | /** | |
336 | * handle_edge_irq - edge type IRQ handler | |
337 | * @irq: the interrupt number | |
338 | * @desc: the interrupt description structure for this irq | |
339 | * @regs: pointer to a register structure | |
340 | * | |
341 | * Interrupt occures on the falling and/or rising edge of a hardware | |
342 | * signal. The occurence is latched into the irq controller hardware | |
343 | * and must be acked in order to be reenabled. After the ack another | |
344 | * interrupt can happen on the same source even before the first one | |
345 | * is handled by the assosiacted event handler. If this happens it | |
346 | * might be necessary to disable (mask) the interrupt depending on the | |
347 | * controller hardware. This requires to reenable the interrupt inside | |
348 | * of the loop which handles the interrupts which have arrived while | |
349 | * the handler was running. If all pending interrupts are handled, the | |
350 | * loop is left. | |
351 | */ | |
352 | void fastcall | |
353 | handle_edge_irq(unsigned int irq, struct irq_desc *desc, struct pt_regs *regs) | |
354 | { | |
355 | const unsigned int cpu = smp_processor_id(); | |
356 | ||
357 | spin_lock(&desc->lock); | |
358 | ||
359 | desc->status &= ~(IRQ_REPLAY | IRQ_WAITING); | |
360 | ||
361 | /* | |
362 | * If we're currently running this IRQ, or its disabled, | |
363 | * we shouldn't process the IRQ. Mark it pending, handle | |
364 | * the necessary masking and go out | |
365 | */ | |
366 | if (unlikely((desc->status & (IRQ_INPROGRESS | IRQ_DISABLED)) || | |
367 | !desc->action)) { | |
368 | desc->status |= (IRQ_PENDING | IRQ_MASKED); | |
369 | mask_ack_irq(desc, irq); | |
370 | goto out_unlock; | |
371 | } | |
372 | ||
373 | kstat_cpu(cpu).irqs[irq]++; | |
374 | ||
375 | /* Start handling the irq */ | |
376 | desc->chip->ack(irq); | |
377 | ||
378 | /* Mark the IRQ currently in progress.*/ | |
379 | desc->status |= IRQ_INPROGRESS; | |
380 | ||
381 | do { | |
382 | struct irqaction *action = desc->action; | |
383 | irqreturn_t action_ret; | |
384 | ||
385 | if (unlikely(!action)) { | |
386 | desc->chip->mask(irq); | |
387 | goto out_unlock; | |
388 | } | |
389 | ||
390 | /* | |
391 | * When another irq arrived while we were handling | |
392 | * one, we could have masked the irq. | |
393 | * Renable it, if it was not disabled in meantime. | |
394 | */ | |
395 | if (unlikely((desc->status & | |
396 | (IRQ_PENDING | IRQ_MASKED | IRQ_DISABLED)) == | |
397 | (IRQ_PENDING | IRQ_MASKED))) { | |
398 | desc->chip->unmask(irq); | |
399 | desc->status &= ~IRQ_MASKED; | |
400 | } | |
401 | ||
402 | desc->status &= ~IRQ_PENDING; | |
403 | spin_unlock(&desc->lock); | |
404 | action_ret = handle_IRQ_event(irq, regs, action); | |
405 | if (!noirqdebug) | |
406 | note_interrupt(irq, desc, action_ret, regs); | |
407 | spin_lock(&desc->lock); | |
408 | ||
409 | } while ((desc->status & (IRQ_PENDING | IRQ_DISABLED)) == IRQ_PENDING); | |
410 | ||
411 | desc->status &= ~IRQ_INPROGRESS; | |
412 | out_unlock: | |
413 | spin_unlock(&desc->lock); | |
414 | } | |
415 | ||
416 | #ifdef CONFIG_SMP | |
417 | /** | |
418 | * handle_percpu_IRQ - Per CPU local irq handler | |
419 | * @irq: the interrupt number | |
420 | * @desc: the interrupt description structure for this irq | |
421 | * @regs: pointer to a register structure | |
422 | * | |
423 | * Per CPU interrupts on SMP machines without locking requirements | |
424 | */ | |
425 | void fastcall | |
426 | handle_percpu_irq(unsigned int irq, struct irq_desc *desc, struct pt_regs *regs) | |
427 | { | |
428 | irqreturn_t action_ret; | |
429 | ||
430 | kstat_this_cpu.irqs[irq]++; | |
431 | ||
432 | if (desc->chip->ack) | |
433 | desc->chip->ack(irq); | |
434 | ||
435 | action_ret = handle_IRQ_event(irq, regs, desc->action); | |
436 | if (!noirqdebug) | |
437 | note_interrupt(irq, desc, action_ret, regs); | |
438 | ||
439 | if (desc->chip->eoi) | |
440 | desc->chip->eoi(irq); | |
441 | } | |
442 | ||
443 | #endif /* CONFIG_SMP */ | |
444 | ||
445 | void | |
446 | __set_irq_handler(unsigned int irq, | |
447 | void fastcall (*handle)(unsigned int, irq_desc_t *, | |
448 | struct pt_regs *), | |
449 | int is_chained) | |
450 | { | |
451 | struct irq_desc *desc; | |
452 | unsigned long flags; | |
453 | ||
454 | if (irq >= NR_IRQS) { | |
455 | printk(KERN_ERR | |
456 | "Trying to install type control for IRQ%d\n", irq); | |
457 | return; | |
458 | } | |
459 | ||
460 | desc = irq_desc + irq; | |
461 | ||
462 | if (!handle) | |
463 | handle = handle_bad_irq; | |
464 | ||
465 | if (is_chained && desc->chip == &no_irq_chip) | |
466 | printk(KERN_WARNING "Trying to install " | |
467 | "chained interrupt type for IRQ%d\n", irq); | |
468 | ||
469 | spin_lock_irqsave(&desc->lock, flags); | |
470 | ||
471 | /* Uninstall? */ | |
472 | if (handle == handle_bad_irq) { | |
473 | if (desc->chip != &no_irq_chip) { | |
474 | desc->chip->mask(irq); | |
475 | desc->chip->ack(irq); | |
476 | } | |
477 | desc->status |= IRQ_DISABLED; | |
478 | desc->depth = 1; | |
479 | } | |
480 | desc->handle_irq = handle; | |
481 | ||
482 | if (handle != handle_bad_irq && is_chained) { | |
483 | desc->status &= ~IRQ_DISABLED; | |
484 | desc->status |= IRQ_NOREQUEST | IRQ_NOPROBE; | |
485 | desc->depth = 0; | |
486 | desc->chip->unmask(irq); | |
487 | } | |
488 | spin_unlock_irqrestore(&desc->lock, flags); | |
489 | } | |
490 | ||
491 | void | |
492 | set_irq_chip_and_handler(unsigned int irq, struct irq_chip *chip, | |
493 | void fastcall (*handle)(unsigned int, | |
494 | struct irq_desc *, | |
495 | struct pt_regs *)) | |
496 | { | |
497 | set_irq_chip(irq, chip); | |
498 | __set_irq_handler(irq, handle, 0); | |
499 | } | |
500 | ||
501 | /* | |
502 | * Get a descriptive string for the highlevel handler, for | |
503 | * /proc/interrupts output: | |
504 | */ | |
505 | const char * | |
506 | handle_irq_name(void fastcall (*handle)(unsigned int, struct irq_desc *, | |
507 | struct pt_regs *)) | |
508 | { | |
509 | if (handle == handle_level_irq) | |
510 | return "level "; | |
511 | if (handle == handle_fastack_irq) | |
512 | return "level "; | |
513 | if (handle == handle_edge_irq) | |
514 | return "edge "; | |
515 | if (handle == handle_simple_irq) | |
516 | return "simple"; | |
517 | #ifdef CONFIG_SMP | |
518 | if (handle == handle_percpu_irq) | |
519 | return "percpu"; | |
520 | #endif | |
521 | if (handle == handle_bad_irq) | |
522 | return "bad "; | |
523 | ||
524 | return NULL; | |
525 | } |