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 /* first time to use this irq_desc */
31 desc = irq_to_desc(irq);
33 WARN(1, KERN_ERR "Trying to initialize invalid IRQ%d\n", irq);
37 /* Ensure we don't have left over values from a previous use of this irq */
38 spin_lock_irqsave(&desc->lock, flags);
39 desc->status = IRQ_DISABLED;
40 desc->chip = &no_irq_chip;
41 desc->handle_irq = handle_bad_irq;
43 desc->msi_desc = NULL;
44 desc->handler_data = NULL;
45 desc->chip_data = NULL;
48 desc->irqs_unhandled = 0;
50 cpus_setall(desc->affinity);
52 spin_unlock_irqrestore(&desc->lock, flags);
56 * dynamic_irq_cleanup - cleanup a dynamically allocated irq
57 * @irq: irq number to initialize
59 void dynamic_irq_cleanup(unsigned int irq)
61 struct irq_desc *desc;
64 desc = irq_to_desc(irq);
66 WARN(1, KERN_ERR "Trying to cleanup invalid IRQ%d\n", irq);
70 spin_lock_irqsave(&desc->lock, flags);
72 spin_unlock_irqrestore(&desc->lock, flags);
73 WARN(1, KERN_ERR "Destroying IRQ%d without calling free_irq\n",
77 desc->msi_desc = NULL;
78 desc->handler_data = NULL;
79 desc->chip_data = NULL;
80 desc->handle_irq = handle_bad_irq;
81 desc->chip = &no_irq_chip;
82 spin_unlock_irqrestore(&desc->lock, flags);
87 * set_irq_chip - set the irq chip for an irq
89 * @chip: pointer to irq chip description structure
91 int set_irq_chip(unsigned int irq, struct irq_chip *chip)
93 struct irq_desc *desc;
96 desc = irq_to_desc(irq);
98 WARN(1, KERN_ERR "Trying to install chip for IRQ%d\n", irq);
105 spin_lock_irqsave(&desc->lock, flags);
106 irq_chip_set_defaults(chip);
108 spin_unlock_irqrestore(&desc->lock, flags);
112 EXPORT_SYMBOL(set_irq_chip);
115 * set_irq_type - set the irq trigger type for an irq
117 * @type: IRQ_TYPE_{LEVEL,EDGE}_* value - see include/linux/irq.h
119 int set_irq_type(unsigned int irq, unsigned int type)
121 struct irq_desc *desc;
125 desc = irq_to_desc(irq);
127 printk(KERN_ERR "Trying to set irq type for IRQ%d\n", irq);
131 if (type == IRQ_TYPE_NONE)
134 spin_lock_irqsave(&desc->lock, flags);
135 ret = __irq_set_trigger(desc, irq, flags);
136 spin_unlock_irqrestore(&desc->lock, flags);
139 EXPORT_SYMBOL(set_irq_type);
142 * set_irq_data - set irq type data for an irq
143 * @irq: Interrupt number
144 * @data: Pointer to interrupt specific data
146 * Set the hardware irq controller data for an irq
148 int set_irq_data(unsigned int irq, void *data)
150 struct irq_desc *desc;
153 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;
179 desc = irq_to_desc(irq);
182 "Trying to install msi data for IRQ%d\n", irq);
186 spin_lock_irqsave(&desc->lock, flags);
187 desc->msi_desc = entry;
190 spin_unlock_irqrestore(&desc->lock, flags);
195 * set_irq_chip_data - set irq chip data for an irq
196 * @irq: Interrupt number
197 * @data: Pointer to chip specific data
199 * Set the hardware irq chip data for an irq
201 int set_irq_chip_data(unsigned int irq, void *data)
203 struct irq_desc *desc;
206 desc = irq_to_desc(irq);
209 "Trying to install chip data for IRQ%d\n", irq);
214 printk(KERN_ERR "BUG: bad set_irq_chip_data(IRQ#%d)\n", irq);
218 spin_lock_irqsave(&desc->lock, flags);
219 desc->chip_data = data;
220 spin_unlock_irqrestore(&desc->lock, flags);
224 EXPORT_SYMBOL(set_irq_chip_data);
227 * default enable function
229 static void default_enable(unsigned int irq)
231 struct irq_desc *desc;
233 desc = irq_to_desc(irq);
234 desc->chip->unmask(irq);
235 desc->status &= ~IRQ_MASKED;
239 * default disable function
241 static void default_disable(unsigned int irq)
246 * default startup function
248 static unsigned int default_startup(unsigned int irq)
250 struct irq_desc *desc;
252 desc = irq_to_desc(irq);
253 desc->chip->enable(irq);
259 * default shutdown function
261 static void default_shutdown(unsigned int irq)
263 struct irq_desc *desc;
265 desc = irq_to_desc(irq);
266 desc->chip->mask(irq);
267 desc->status |= IRQ_MASKED;
271 * Fixup enable/disable function pointers
273 void irq_chip_set_defaults(struct irq_chip *chip)
276 chip->enable = default_enable;
278 chip->disable = default_disable;
280 chip->startup = default_startup;
282 * We use chip->disable, when the user provided its own. When
283 * we have default_disable set for chip->disable, then we need
284 * to use default_shutdown, otherwise the irq line is not
285 * disabled on free_irq():
288 chip->shutdown = chip->disable != default_disable ?
289 chip->disable : default_shutdown;
291 chip->name = chip->typename;
293 chip->end = dummy_irq_chip.end;
296 static inline void mask_ack_irq(struct irq_desc *desc, int irq)
298 if (desc->chip->mask_ack)
299 desc->chip->mask_ack(irq);
301 desc->chip->mask(irq);
302 desc->chip->ack(irq);
307 * handle_simple_irq - Simple and software-decoded IRQs.
308 * @irq: the interrupt number
309 * @desc: the interrupt description structure for this irq
311 * Simple interrupts are either sent from a demultiplexing interrupt
312 * handler or come from hardware, where no interrupt hardware control
315 * Note: The caller is expected to handle the ack, clear, mask and
316 * unmask issues if necessary.
319 handle_simple_irq(unsigned int irq, struct irq_desc *desc)
321 struct irqaction *action;
322 irqreturn_t action_ret;
324 spin_lock(&desc->lock);
326 if (unlikely(desc->status & IRQ_INPROGRESS))
328 desc->status &= ~(IRQ_REPLAY | IRQ_WAITING);
329 kstat_incr_irqs_this_cpu(irq, desc);
331 action = desc->action;
332 if (unlikely(!action || (desc->status & IRQ_DISABLED)))
335 desc->status |= IRQ_INPROGRESS;
336 spin_unlock(&desc->lock);
338 action_ret = handle_IRQ_event(irq, action);
340 note_interrupt(irq, desc, action_ret);
342 spin_lock(&desc->lock);
343 desc->status &= ~IRQ_INPROGRESS;
345 spin_unlock(&desc->lock);
349 * handle_level_irq - Level type irq handler
350 * @irq: the interrupt number
351 * @desc: the interrupt description structure for this irq
353 * Level type interrupts are active as long as the hardware line has
354 * the active level. This may require to mask the interrupt and unmask
355 * it after the associated handler has acknowledged the device, so the
356 * interrupt line is back to inactive.
359 handle_level_irq(unsigned int irq, struct irq_desc *desc)
361 struct irqaction *action;
362 irqreturn_t action_ret;
364 spin_lock(&desc->lock);
365 mask_ack_irq(desc, irq);
367 if (unlikely(desc->status & IRQ_INPROGRESS))
369 desc->status &= ~(IRQ_REPLAY | IRQ_WAITING);
370 kstat_incr_irqs_this_cpu(irq, desc);
373 * If its disabled or no action available
374 * keep it masked and get out of here
376 action = desc->action;
377 if (unlikely(!action || (desc->status & IRQ_DISABLED)))
380 desc->status |= IRQ_INPROGRESS;
381 spin_unlock(&desc->lock);
383 action_ret = handle_IRQ_event(irq, action);
385 note_interrupt(irq, desc, action_ret);
387 spin_lock(&desc->lock);
388 desc->status &= ~IRQ_INPROGRESS;
389 if (!(desc->status & IRQ_DISABLED) && desc->chip->unmask)
390 desc->chip->unmask(irq);
392 spin_unlock(&desc->lock);
396 * handle_fasteoi_irq - irq handler for transparent controllers
397 * @irq: the interrupt number
398 * @desc: the interrupt description structure for this irq
400 * Only a single callback will be issued to the chip: an ->eoi()
401 * call when the interrupt has been serviced. This enables support
402 * for modern forms of interrupt handlers, which handle the flow
403 * details in hardware, transparently.
406 handle_fasteoi_irq(unsigned int irq, struct irq_desc *desc)
408 struct irqaction *action;
409 irqreturn_t action_ret;
411 spin_lock(&desc->lock);
413 if (unlikely(desc->status & IRQ_INPROGRESS))
416 desc->status &= ~(IRQ_REPLAY | IRQ_WAITING);
417 kstat_incr_irqs_this_cpu(irq, desc);
420 * If its disabled or no action available
421 * then mask it and get out of here:
423 action = desc->action;
424 if (unlikely(!action || (desc->status & IRQ_DISABLED))) {
425 desc->status |= IRQ_PENDING;
426 if (desc->chip->mask)
427 desc->chip->mask(irq);
431 desc->status |= IRQ_INPROGRESS;
432 desc->status &= ~IRQ_PENDING;
433 spin_unlock(&desc->lock);
435 action_ret = handle_IRQ_event(irq, action);
437 note_interrupt(irq, desc, action_ret);
439 spin_lock(&desc->lock);
440 desc->status &= ~IRQ_INPROGRESS;
442 desc->chip->eoi(irq);
444 spin_unlock(&desc->lock);
448 * handle_edge_irq - edge type IRQ handler
449 * @irq: the interrupt number
450 * @desc: the interrupt description structure for this irq
452 * Interrupt occures on the falling and/or rising edge of a hardware
453 * signal. The occurence is latched into the irq controller hardware
454 * and must be acked in order to be reenabled. After the ack another
455 * interrupt can happen on the same source even before the first one
456 * is handled by the assosiacted event handler. If this happens it
457 * might be necessary to disable (mask) the interrupt depending on the
458 * controller hardware. This requires to reenable the interrupt inside
459 * of the loop which handles the interrupts which have arrived while
460 * the handler was running. If all pending interrupts are handled, the
464 handle_edge_irq(unsigned int irq, struct irq_desc *desc)
466 spin_lock(&desc->lock);
468 desc->status &= ~(IRQ_REPLAY | IRQ_WAITING);
471 * If we're currently running this IRQ, or its disabled,
472 * we shouldn't process the IRQ. Mark it pending, handle
473 * the necessary masking and go out
475 if (unlikely((desc->status & (IRQ_INPROGRESS | IRQ_DISABLED)) ||
477 desc->status |= (IRQ_PENDING | IRQ_MASKED);
478 mask_ack_irq(desc, irq);
481 kstat_incr_irqs_this_cpu(irq, desc);
483 /* Start handling the irq */
484 desc->chip->ack(irq);
486 /* Mark the IRQ currently in progress.*/
487 desc->status |= IRQ_INPROGRESS;
490 struct irqaction *action = desc->action;
491 irqreturn_t action_ret;
493 if (unlikely(!action)) {
494 desc->chip->mask(irq);
499 * When another irq arrived while we were handling
500 * one, we could have masked the irq.
501 * Renable it, if it was not disabled in meantime.
503 if (unlikely((desc->status &
504 (IRQ_PENDING | IRQ_MASKED | IRQ_DISABLED)) ==
505 (IRQ_PENDING | IRQ_MASKED))) {
506 desc->chip->unmask(irq);
507 desc->status &= ~IRQ_MASKED;
510 desc->status &= ~IRQ_PENDING;
511 spin_unlock(&desc->lock);
512 action_ret = handle_IRQ_event(irq, action);
514 note_interrupt(irq, desc, action_ret);
515 spin_lock(&desc->lock);
517 } while ((desc->status & (IRQ_PENDING | IRQ_DISABLED)) == IRQ_PENDING);
519 desc->status &= ~IRQ_INPROGRESS;
521 spin_unlock(&desc->lock);
525 * handle_percpu_IRQ - Per CPU local irq handler
526 * @irq: the interrupt number
527 * @desc: the interrupt description structure for this irq
529 * Per CPU interrupts on SMP machines without locking requirements
532 handle_percpu_irq(unsigned int irq, struct irq_desc *desc)
534 irqreturn_t action_ret;
536 kstat_incr_irqs_this_cpu(irq, desc);
539 desc->chip->ack(irq);
541 action_ret = handle_IRQ_event(irq, desc->action);
543 note_interrupt(irq, desc, action_ret);
546 desc->chip->eoi(irq);
550 __set_irq_handler(unsigned int irq, irq_flow_handler_t handle, int is_chained,
553 struct irq_desc *desc;
556 desc = irq_to_desc(irq);
559 "Trying to install type control for IRQ%d\n", irq);
564 handle = handle_bad_irq;
565 else if (desc->chip == &no_irq_chip) {
566 printk(KERN_WARNING "Trying to install %sinterrupt handler "
567 "for IRQ%d\n", is_chained ? "chained " : "", irq);
569 * Some ARM implementations install a handler for really dumb
570 * interrupt hardware without setting an irq_chip. This worked
571 * with the ARM no_irq_chip but the check in setup_irq would
572 * prevent us to setup the interrupt at all. Switch it to
573 * dummy_irq_chip for easy transition.
575 desc->chip = &dummy_irq_chip;
578 spin_lock_irqsave(&desc->lock, flags);
581 if (handle == handle_bad_irq) {
582 if (desc->chip != &no_irq_chip)
583 mask_ack_irq(desc, irq);
584 desc->status |= IRQ_DISABLED;
587 desc->handle_irq = handle;
590 if (handle != handle_bad_irq && is_chained) {
591 desc->status &= ~IRQ_DISABLED;
592 desc->status |= IRQ_NOREQUEST | IRQ_NOPROBE;
594 desc->chip->startup(irq);
596 spin_unlock_irqrestore(&desc->lock, flags);
600 set_irq_chip_and_handler(unsigned int irq, struct irq_chip *chip,
601 irq_flow_handler_t handle)
603 set_irq_chip(irq, chip);
604 __set_irq_handler(irq, handle, 0, NULL);
608 set_irq_chip_and_handler_name(unsigned int irq, struct irq_chip *chip,
609 irq_flow_handler_t handle, const char *name)
611 set_irq_chip(irq, chip);
612 __set_irq_handler(irq, handle, 0, name);
615 void __init set_irq_noprobe(unsigned int irq)
617 struct irq_desc *desc;
620 desc = irq_to_desc(irq);
622 printk(KERN_ERR "Trying to mark IRQ%d non-probeable\n", irq);
627 spin_lock_irqsave(&desc->lock, flags);
628 desc->status |= IRQ_NOPROBE;
629 spin_unlock_irqrestore(&desc->lock, flags);
632 void __init set_irq_probe(unsigned int irq)
634 struct irq_desc *desc;
637 desc = irq_to_desc(irq);
639 printk(KERN_ERR "Trying to mark IRQ%d probeable\n", irq);
644 spin_lock_irqsave(&desc->lock, flags);
645 desc->status &= ~IRQ_NOPROBE;
646 spin_unlock_irqrestore(&desc->lock, flags);