2 * linux/kernel/irq/chip.c
4 * Copyright (C) 1992, 1998-2006 Linus Torvalds, Ingo Molnar
5 * Copyright (C) 2005-2006, Thomas Gleixner, Russell King
7 * This file contains the core interrupt handling code, for irq-chip
10 * Detailed information is available in Documentation/DocBook/genericirq
13 #include <linux/irq.h>
14 #include <linux/msi.h>
15 #include <linux/module.h>
16 #include <linux/interrupt.h>
17 #include <linux/kernel_stat.h>
19 #include "internals.h"
22 * dynamic_irq_init - initialize a dynamically allocated irq
23 * @irq: irq number to initialize
25 void dynamic_irq_init(unsigned int irq)
27 struct irq_desc *desc;
30 desc = irq_to_desc(irq);
32 WARN(1, KERN_ERR "Trying to initialize invalid IRQ%d\n", irq);
36 /* Ensure we don't have left over values from a previous use of this irq */
37 spin_lock_irqsave(&desc->lock, flags);
38 desc->status = IRQ_DISABLED;
39 desc->chip = &no_irq_chip;
40 desc->handle_irq = handle_bad_irq;
42 desc->msi_desc = NULL;
43 desc->handler_data = NULL;
44 desc->chip_data = NULL;
47 desc->irqs_unhandled = 0;
49 cpumask_setall(desc->affinity);
50 #ifdef CONFIG_GENERIC_PENDING_IRQ
51 cpumask_clear(desc->pending_mask);
54 spin_unlock_irqrestore(&desc->lock, flags);
58 * dynamic_irq_cleanup - cleanup a dynamically allocated irq
59 * @irq: irq number to initialize
61 void dynamic_irq_cleanup(unsigned int irq)
63 struct irq_desc *desc = irq_to_desc(irq);
67 WARN(1, KERN_ERR "Trying to cleanup invalid IRQ%d\n", irq);
71 spin_lock_irqsave(&desc->lock, flags);
73 spin_unlock_irqrestore(&desc->lock, flags);
74 WARN(1, KERN_ERR "Destroying IRQ%d without calling free_irq\n",
78 desc->msi_desc = NULL;
79 desc->handler_data = NULL;
80 desc->chip_data = NULL;
81 desc->handle_irq = handle_bad_irq;
82 desc->chip = &no_irq_chip;
84 spin_unlock_irqrestore(&desc->lock, flags);
89 * set_irq_chip - set the irq chip for an irq
91 * @chip: pointer to irq chip description structure
93 int set_irq_chip(unsigned int irq, struct irq_chip *chip)
95 struct irq_desc *desc = irq_to_desc(irq);
99 WARN(1, KERN_ERR "Trying to install chip for IRQ%d\n", irq);
106 spin_lock_irqsave(&desc->lock, flags);
107 irq_chip_set_defaults(chip);
109 spin_unlock_irqrestore(&desc->lock, flags);
113 EXPORT_SYMBOL(set_irq_chip);
116 * set_irq_type - set the irq trigger type for an irq
118 * @type: IRQ_TYPE_{LEVEL,EDGE}_* value - see include/linux/irq.h
120 int set_irq_type(unsigned int irq, unsigned int type)
122 struct irq_desc *desc = irq_to_desc(irq);
127 printk(KERN_ERR "Trying to set irq type for IRQ%d\n", irq);
131 type &= IRQ_TYPE_SENSE_MASK;
132 if (type == IRQ_TYPE_NONE)
135 spin_lock_irqsave(&desc->lock, flags);
136 ret = __irq_set_trigger(desc, irq, type);
137 spin_unlock_irqrestore(&desc->lock, flags);
140 EXPORT_SYMBOL(set_irq_type);
143 * set_irq_data - set irq type data for an irq
144 * @irq: Interrupt number
145 * @data: Pointer to interrupt specific data
147 * Set the hardware irq controller data for an irq
149 int set_irq_data(unsigned int irq, void *data)
151 struct irq_desc *desc = irq_to_desc(irq);
156 "Trying to install controller data for IRQ%d\n", irq);
160 spin_lock_irqsave(&desc->lock, flags);
161 desc->handler_data = data;
162 spin_unlock_irqrestore(&desc->lock, flags);
165 EXPORT_SYMBOL(set_irq_data);
168 * set_irq_data - set irq type data for an irq
169 * @irq: Interrupt number
170 * @entry: Pointer to MSI descriptor data
172 * Set the hardware irq controller data for an irq
174 int set_irq_msi(unsigned int irq, struct msi_desc *entry)
176 struct irq_desc *desc = irq_to_desc(irq);
181 "Trying to install msi data for IRQ%d\n", irq);
185 spin_lock_irqsave(&desc->lock, flags);
186 desc->msi_desc = entry;
189 spin_unlock_irqrestore(&desc->lock, flags);
194 * set_irq_chip_data - set irq chip data for an irq
195 * @irq: Interrupt number
196 * @data: Pointer to chip specific data
198 * Set the hardware irq chip data for an irq
200 int set_irq_chip_data(unsigned int irq, void *data)
202 struct irq_desc *desc = irq_to_desc(irq);
207 "Trying to install chip data for IRQ%d\n", irq);
212 printk(KERN_ERR "BUG: bad set_irq_chip_data(IRQ#%d)\n", irq);
216 spin_lock_irqsave(&desc->lock, flags);
217 desc->chip_data = data;
218 spin_unlock_irqrestore(&desc->lock, flags);
222 EXPORT_SYMBOL(set_irq_chip_data);
225 * default enable function
227 static void default_enable(unsigned int irq)
229 struct irq_desc *desc = irq_to_desc(irq);
231 desc->chip->unmask(irq);
232 desc->status &= ~IRQ_MASKED;
236 * default disable function
238 static void default_disable(unsigned int irq)
243 * default startup function
245 static unsigned int default_startup(unsigned int irq)
247 struct irq_desc *desc = irq_to_desc(irq);
249 desc->chip->enable(irq);
254 * default shutdown function
256 static void default_shutdown(unsigned int irq)
258 struct irq_desc *desc = irq_to_desc(irq);
260 desc->chip->mask(irq);
261 desc->status |= IRQ_MASKED;
265 * Fixup enable/disable function pointers
267 void irq_chip_set_defaults(struct irq_chip *chip)
270 chip->enable = default_enable;
272 chip->disable = default_disable;
274 chip->startup = default_startup;
276 * We use chip->disable, when the user provided its own. When
277 * we have default_disable set for chip->disable, then we need
278 * to use default_shutdown, otherwise the irq line is not
279 * disabled on free_irq():
282 chip->shutdown = chip->disable != default_disable ?
283 chip->disable : default_shutdown;
285 chip->name = chip->typename;
287 chip->end = dummy_irq_chip.end;
290 static inline void mask_ack_irq(struct irq_desc *desc, int irq)
292 if (desc->chip->mask_ack)
293 desc->chip->mask_ack(irq);
295 desc->chip->mask(irq);
296 desc->chip->ack(irq);
301 * handle_simple_irq - Simple and software-decoded IRQs.
302 * @irq: the interrupt number
303 * @desc: the interrupt description structure for this irq
305 * Simple interrupts are either sent from a demultiplexing interrupt
306 * handler or come from hardware, where no interrupt hardware control
309 * Note: The caller is expected to handle the ack, clear, mask and
310 * unmask issues if necessary.
313 handle_simple_irq(unsigned int irq, struct irq_desc *desc)
315 struct irqaction *action;
316 irqreturn_t action_ret;
318 spin_lock(&desc->lock);
320 if (unlikely(desc->status & IRQ_INPROGRESS))
322 desc->status &= ~(IRQ_REPLAY | IRQ_WAITING);
323 kstat_incr_irqs_this_cpu(irq, desc);
325 action = desc->action;
326 if (unlikely(!action || (desc->status & IRQ_DISABLED)))
329 desc->status |= IRQ_INPROGRESS;
330 spin_unlock(&desc->lock);
332 action_ret = handle_IRQ_event(irq, action);
334 note_interrupt(irq, desc, action_ret);
336 spin_lock(&desc->lock);
337 desc->status &= ~IRQ_INPROGRESS;
339 spin_unlock(&desc->lock);
343 * handle_level_irq - Level type irq handler
344 * @irq: the interrupt number
345 * @desc: the interrupt description structure for this irq
347 * Level type interrupts are active as long as the hardware line has
348 * the active level. This may require to mask the interrupt and unmask
349 * it after the associated handler has acknowledged the device, so the
350 * interrupt line is back to inactive.
353 handle_level_irq(unsigned int irq, struct irq_desc *desc)
355 struct irqaction *action;
356 irqreturn_t action_ret;
358 spin_lock(&desc->lock);
359 mask_ack_irq(desc, irq);
360 desc = irq_remap_to_desc(irq, desc);
362 if (unlikely(desc->status & IRQ_INPROGRESS))
364 desc->status &= ~(IRQ_REPLAY | IRQ_WAITING);
365 kstat_incr_irqs_this_cpu(irq, desc);
368 * If its disabled or no action available
369 * keep it masked and get out of here
371 action = desc->action;
372 if (unlikely(!action || (desc->status & IRQ_DISABLED)))
375 desc->status |= IRQ_INPROGRESS;
376 spin_unlock(&desc->lock);
378 action_ret = handle_IRQ_event(irq, action);
380 note_interrupt(irq, desc, action_ret);
382 spin_lock(&desc->lock);
383 desc->status &= ~IRQ_INPROGRESS;
384 if (!(desc->status & IRQ_DISABLED) && desc->chip->unmask)
385 desc->chip->unmask(irq);
387 spin_unlock(&desc->lock);
391 * handle_fasteoi_irq - irq handler for transparent controllers
392 * @irq: the interrupt number
393 * @desc: the interrupt description structure for this irq
395 * Only a single callback will be issued to the chip: an ->eoi()
396 * call when the interrupt has been serviced. This enables support
397 * for modern forms of interrupt handlers, which handle the flow
398 * details in hardware, transparently.
401 handle_fasteoi_irq(unsigned int irq, struct irq_desc *desc)
403 struct irqaction *action;
404 irqreturn_t action_ret;
406 spin_lock(&desc->lock);
408 if (unlikely(desc->status & IRQ_INPROGRESS))
411 desc->status &= ~(IRQ_REPLAY | IRQ_WAITING);
412 kstat_incr_irqs_this_cpu(irq, desc);
415 * If its disabled or no action available
416 * then mask it and get out of here:
418 action = desc->action;
419 if (unlikely(!action || (desc->status & IRQ_DISABLED))) {
420 desc->status |= IRQ_PENDING;
421 if (desc->chip->mask)
422 desc->chip->mask(irq);
426 desc->status |= IRQ_INPROGRESS;
427 desc->status &= ~IRQ_PENDING;
428 spin_unlock(&desc->lock);
430 action_ret = handle_IRQ_event(irq, action);
432 note_interrupt(irq, desc, action_ret);
434 spin_lock(&desc->lock);
435 desc->status &= ~IRQ_INPROGRESS;
437 desc->chip->eoi(irq);
438 desc = irq_remap_to_desc(irq, desc);
440 spin_unlock(&desc->lock);
444 * handle_edge_irq - edge type IRQ handler
445 * @irq: the interrupt number
446 * @desc: the interrupt description structure for this irq
448 * Interrupt occures on the falling and/or rising edge of a hardware
449 * signal. The occurence is latched into the irq controller hardware
450 * and must be acked in order to be reenabled. After the ack another
451 * interrupt can happen on the same source even before the first one
452 * is handled by the assosiacted event handler. If this happens it
453 * might be necessary to disable (mask) the interrupt depending on the
454 * controller hardware. This requires to reenable the interrupt inside
455 * of the loop which handles the interrupts which have arrived while
456 * the handler was running. If all pending interrupts are handled, the
460 handle_edge_irq(unsigned int irq, struct irq_desc *desc)
462 spin_lock(&desc->lock);
464 desc->status &= ~(IRQ_REPLAY | IRQ_WAITING);
467 * If we're currently running this IRQ, or its disabled,
468 * we shouldn't process the IRQ. Mark it pending, handle
469 * the necessary masking and go out
471 if (unlikely((desc->status & (IRQ_INPROGRESS | IRQ_DISABLED)) ||
473 desc->status |= (IRQ_PENDING | IRQ_MASKED);
474 mask_ack_irq(desc, irq);
475 desc = irq_remap_to_desc(irq, desc);
478 kstat_incr_irqs_this_cpu(irq, desc);
480 /* Start handling the irq */
481 desc->chip->ack(irq);
482 desc = irq_remap_to_desc(irq, desc);
484 /* Mark the IRQ currently in progress.*/
485 desc->status |= IRQ_INPROGRESS;
488 struct irqaction *action = desc->action;
489 irqreturn_t action_ret;
491 if (unlikely(!action)) {
492 desc->chip->mask(irq);
497 * When another irq arrived while we were handling
498 * one, we could have masked the irq.
499 * Renable it, if it was not disabled in meantime.
501 if (unlikely((desc->status &
502 (IRQ_PENDING | IRQ_MASKED | IRQ_DISABLED)) ==
503 (IRQ_PENDING | IRQ_MASKED))) {
504 desc->chip->unmask(irq);
505 desc->status &= ~IRQ_MASKED;
508 desc->status &= ~IRQ_PENDING;
509 spin_unlock(&desc->lock);
510 action_ret = handle_IRQ_event(irq, action);
512 note_interrupt(irq, desc, action_ret);
513 spin_lock(&desc->lock);
515 } while ((desc->status & (IRQ_PENDING | IRQ_DISABLED)) == IRQ_PENDING);
517 desc->status &= ~IRQ_INPROGRESS;
519 spin_unlock(&desc->lock);
523 * handle_percpu_IRQ - Per CPU local irq handler
524 * @irq: the interrupt number
525 * @desc: the interrupt description structure for this irq
527 * Per CPU interrupts on SMP machines without locking requirements
530 handle_percpu_irq(unsigned int irq, struct irq_desc *desc)
532 irqreturn_t action_ret;
534 kstat_incr_irqs_this_cpu(irq, desc);
537 desc->chip->ack(irq);
539 action_ret = handle_IRQ_event(irq, desc->action);
541 note_interrupt(irq, desc, action_ret);
543 if (desc->chip->eoi) {
544 desc->chip->eoi(irq);
545 desc = irq_remap_to_desc(irq, desc);
550 __set_irq_handler(unsigned int irq, irq_flow_handler_t handle, int is_chained,
553 struct irq_desc *desc = irq_to_desc(irq);
558 "Trying to install type control for IRQ%d\n", irq);
563 handle = handle_bad_irq;
564 else if (desc->chip == &no_irq_chip) {
565 printk(KERN_WARNING "Trying to install %sinterrupt handler "
566 "for IRQ%d\n", is_chained ? "chained " : "", irq);
568 * Some ARM implementations install a handler for really dumb
569 * interrupt hardware without setting an irq_chip. This worked
570 * with the ARM no_irq_chip but the check in setup_irq would
571 * prevent us to setup the interrupt at all. Switch it to
572 * dummy_irq_chip for easy transition.
574 desc->chip = &dummy_irq_chip;
577 spin_lock_irqsave(&desc->lock, flags);
580 if (handle == handle_bad_irq) {
581 if (desc->chip != &no_irq_chip) {
582 mask_ack_irq(desc, irq);
583 desc = irq_remap_to_desc(irq, desc);
585 desc->status |= IRQ_DISABLED;
588 desc->handle_irq = handle;
591 if (handle != handle_bad_irq && is_chained) {
592 desc->status &= ~IRQ_DISABLED;
593 desc->status |= IRQ_NOREQUEST | IRQ_NOPROBE;
595 desc->chip->startup(irq);
597 spin_unlock_irqrestore(&desc->lock, flags);
601 set_irq_chip_and_handler(unsigned int irq, struct irq_chip *chip,
602 irq_flow_handler_t handle)
604 set_irq_chip(irq, chip);
605 __set_irq_handler(irq, handle, 0, NULL);
609 set_irq_chip_and_handler_name(unsigned int irq, struct irq_chip *chip,
610 irq_flow_handler_t handle, const char *name)
612 set_irq_chip(irq, chip);
613 __set_irq_handler(irq, handle, 0, name);
616 void __init set_irq_noprobe(unsigned int irq)
618 struct irq_desc *desc = irq_to_desc(irq);
622 printk(KERN_ERR "Trying to mark IRQ%d non-probeable\n", irq);
626 spin_lock_irqsave(&desc->lock, flags);
627 desc->status |= IRQ_NOPROBE;
628 spin_unlock_irqrestore(&desc->lock, flags);
631 void __init set_irq_probe(unsigned int irq)
633 struct irq_desc *desc = irq_to_desc(irq);
637 printk(KERN_ERR "Trying to mark IRQ%d probeable\n", irq);
641 spin_lock_irqsave(&desc->lock, flags);
642 desc->status &= ~IRQ_NOPROBE;
643 spin_unlock_irqrestore(&desc->lock, flags);