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
;
31 printk(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 desc
= irq_desc
+ 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 desc
->affinity
= CPU_MASK_ALL
;
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
;
65 printk(KERN_ERR
"Trying to cleanup invalid IRQ%d\n", irq
);
70 desc
= irq_desc
+ irq
;
71 spin_lock_irqsave(&desc
->lock
, flags
);
73 spin_unlock_irqrestore(&desc
->lock
, flags
);
74 printk(KERN_ERR
"Destroying IRQ%d without calling free_irq\n",
79 desc
->msi_desc
= NULL
;
80 desc
->handler_data
= NULL
;
81 desc
->chip_data
= NULL
;
82 desc
->handle_irq
= handle_bad_irq
;
83 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
;
99 printk(KERN_ERR
"Trying to install chip for IRQ%d\n", irq
);
107 desc
= irq_desc
+ irq
;
108 spin_lock_irqsave(&desc
->lock
, flags
);
109 irq_chip_set_defaults(chip
);
111 spin_unlock_irqrestore(&desc
->lock
, flags
);
115 EXPORT_SYMBOL(set_irq_chip
);
118 * set_irq_type - set the irq type for an irq
120 * @type: interrupt type - see include/linux/interrupt.h
122 int set_irq_type(unsigned int irq
, unsigned int type
)
124 struct irq_desc
*desc
;
128 if (irq
>= NR_IRQS
) {
129 printk(KERN_ERR
"Trying to set irq type for IRQ%d\n", irq
);
133 desc
= irq_desc
+ irq
;
134 if (desc
->chip
->set_type
) {
135 spin_lock_irqsave(&desc
->lock
, flags
);
136 ret
= desc
->chip
->set_type(irq
, type
);
137 spin_unlock_irqrestore(&desc
->lock
, flags
);
141 EXPORT_SYMBOL(set_irq_type
);
144 * set_irq_data - set irq type data for an irq
145 * @irq: Interrupt number
146 * @data: Pointer to interrupt specific data
148 * Set the hardware irq controller data for an irq
150 int set_irq_data(unsigned int irq
, void *data
)
152 struct irq_desc
*desc
;
155 if (irq
>= NR_IRQS
) {
157 "Trying to install controller data for IRQ%d\n", irq
);
161 desc
= irq_desc
+ irq
;
162 spin_lock_irqsave(&desc
->lock
, flags
);
163 desc
->handler_data
= data
;
164 spin_unlock_irqrestore(&desc
->lock
, flags
);
167 EXPORT_SYMBOL(set_irq_data
);
170 * set_irq_data - set irq type data for an irq
171 * @irq: Interrupt number
172 * @entry: Pointer to MSI descriptor data
174 * Set the hardware irq controller data for an irq
176 int set_irq_msi(unsigned int irq
, struct msi_desc
*entry
)
178 struct irq_desc
*desc
;
181 if (irq
>= NR_IRQS
) {
183 "Trying to install msi data for IRQ%d\n", irq
);
186 desc
= irq_desc
+ irq
;
187 spin_lock_irqsave(&desc
->lock
, flags
);
188 desc
->msi_desc
= entry
;
191 spin_unlock_irqrestore(&desc
->lock
, flags
);
196 * set_irq_chip_data - set irq chip data for an irq
197 * @irq: Interrupt number
198 * @data: Pointer to chip specific data
200 * Set the hardware irq chip data for an irq
202 int set_irq_chip_data(unsigned int irq
, void *data
)
204 struct irq_desc
*desc
= irq_desc
+ irq
;
207 if (irq
>= NR_IRQS
|| !desc
->chip
) {
208 printk(KERN_ERR
"BUG: bad set_irq_chip_data(IRQ#%d)\n", irq
);
212 spin_lock_irqsave(&desc
->lock
, flags
);
213 desc
->chip_data
= data
;
214 spin_unlock_irqrestore(&desc
->lock
, flags
);
218 EXPORT_SYMBOL(set_irq_chip_data
);
221 * default enable function
223 static void default_enable(unsigned int irq
)
225 struct irq_desc
*desc
= irq_desc
+ irq
;
227 desc
->chip
->unmask(irq
);
228 desc
->status
&= ~IRQ_MASKED
;
232 * default disable function
234 static void default_disable(unsigned int irq
)
239 * default startup function
241 static unsigned int default_startup(unsigned int irq
)
243 irq_desc
[irq
].chip
->enable(irq
);
249 * default shutdown function
251 static void default_shutdown(unsigned int irq
)
253 struct irq_desc
*desc
= irq_desc
+ irq
;
255 desc
->chip
->mask(irq
);
256 desc
->status
|= IRQ_MASKED
;
260 * Fixup enable/disable function pointers
262 void irq_chip_set_defaults(struct irq_chip
*chip
)
265 chip
->enable
= default_enable
;
267 chip
->disable
= default_disable
;
269 chip
->startup
= default_startup
;
271 * We use chip->disable, when the user provided its own. When
272 * we have default_disable set for chip->disable, then we need
273 * to use default_shutdown, otherwise the irq line is not
274 * disabled on free_irq():
277 chip
->shutdown
= chip
->disable
!= default_disable
?
278 chip
->disable
: default_shutdown
;
280 chip
->name
= chip
->typename
;
282 chip
->end
= dummy_irq_chip
.end
;
285 static inline void mask_ack_irq(struct irq_desc
*desc
, int irq
)
287 if (desc
->chip
->mask_ack
)
288 desc
->chip
->mask_ack(irq
);
290 desc
->chip
->mask(irq
);
291 desc
->chip
->ack(irq
);
296 * handle_simple_irq - Simple and software-decoded IRQs.
297 * @irq: the interrupt number
298 * @desc: the interrupt description structure for this irq
300 * Simple interrupts are either sent from a demultiplexing interrupt
301 * handler or come from hardware, where no interrupt hardware control
304 * Note: The caller is expected to handle the ack, clear, mask and
305 * unmask issues if necessary.
308 handle_simple_irq(unsigned int irq
, struct irq_desc
*desc
)
310 struct irqaction
*action
;
311 irqreturn_t action_ret
;
312 const unsigned int cpu
= smp_processor_id();
314 spin_lock(&desc
->lock
);
316 if (unlikely(desc
->status
& IRQ_INPROGRESS
))
318 kstat_cpu(cpu
).irqs
[irq
]++;
320 action
= desc
->action
;
321 if (unlikely(!action
|| (desc
->status
& IRQ_DISABLED
))) {
322 if (desc
->chip
->mask
)
323 desc
->chip
->mask(irq
);
324 desc
->status
&= ~(IRQ_REPLAY
| IRQ_WAITING
);
325 desc
->status
|= IRQ_PENDING
;
329 desc
->status
&= ~(IRQ_REPLAY
| IRQ_WAITING
| IRQ_PENDING
);
330 desc
->status
|= IRQ_INPROGRESS
;
331 spin_unlock(&desc
->lock
);
333 action_ret
= handle_IRQ_event(irq
, action
);
335 note_interrupt(irq
, desc
, action_ret
);
337 spin_lock(&desc
->lock
);
338 desc
->status
&= ~IRQ_INPROGRESS
;
340 spin_unlock(&desc
->lock
);
344 * handle_level_irq - Level type irq handler
345 * @irq: the interrupt number
346 * @desc: the interrupt description structure for this irq
348 * Level type interrupts are active as long as the hardware line has
349 * the active level. This may require to mask the interrupt and unmask
350 * it after the associated handler has acknowledged the device, so the
351 * interrupt line is back to inactive.
354 handle_level_irq(unsigned int irq
, struct irq_desc
*desc
)
356 unsigned int cpu
= smp_processor_id();
357 struct irqaction
*action
;
358 irqreturn_t action_ret
;
360 spin_lock(&desc
->lock
);
361 mask_ack_irq(desc
, irq
);
363 if (unlikely(desc
->status
& IRQ_INPROGRESS
))
365 desc
->status
&= ~(IRQ_REPLAY
| IRQ_WAITING
);
366 kstat_cpu(cpu
).irqs
[irq
]++;
369 * If its disabled or no action available
370 * keep it masked and get out of here
372 action
= desc
->action
;
373 if (unlikely(!action
|| (desc
->status
& IRQ_DISABLED
)))
376 desc
->status
|= IRQ_INPROGRESS
;
377 spin_unlock(&desc
->lock
);
379 action_ret
= handle_IRQ_event(irq
, action
);
381 note_interrupt(irq
, desc
, action_ret
);
383 spin_lock(&desc
->lock
);
384 desc
->status
&= ~IRQ_INPROGRESS
;
385 if (!(desc
->status
& IRQ_DISABLED
) && desc
->chip
->unmask
)
386 desc
->chip
->unmask(irq
);
388 spin_unlock(&desc
->lock
);
392 * handle_fasteoi_irq - irq handler for transparent controllers
393 * @irq: the interrupt number
394 * @desc: the interrupt description structure for this irq
396 * Only a single callback will be issued to the chip: an ->eoi()
397 * call when the interrupt has been serviced. This enables support
398 * for modern forms of interrupt handlers, which handle the flow
399 * details in hardware, transparently.
402 handle_fasteoi_irq(unsigned int irq
, struct irq_desc
*desc
)
404 unsigned int cpu
= smp_processor_id();
405 struct irqaction
*action
;
406 irqreturn_t action_ret
;
408 spin_lock(&desc
->lock
);
410 if (unlikely(desc
->status
& IRQ_INPROGRESS
))
413 desc
->status
&= ~(IRQ_REPLAY
| IRQ_WAITING
);
414 kstat_cpu(cpu
).irqs
[irq
]++;
417 * If its disabled or no action available
418 * then mask it and get out of here:
420 action
= desc
->action
;
421 if (unlikely(!action
|| (desc
->status
& IRQ_DISABLED
))) {
422 desc
->status
|= IRQ_PENDING
;
423 if (desc
->chip
->mask
)
424 desc
->chip
->mask(irq
);
428 desc
->status
|= IRQ_INPROGRESS
;
429 desc
->status
&= ~IRQ_PENDING
;
430 spin_unlock(&desc
->lock
);
432 action_ret
= handle_IRQ_event(irq
, action
);
434 note_interrupt(irq
, desc
, action_ret
);
436 spin_lock(&desc
->lock
);
437 desc
->status
&= ~IRQ_INPROGRESS
;
439 desc
->chip
->eoi(irq
);
441 spin_unlock(&desc
->lock
);
445 * handle_edge_irq - edge type IRQ handler
446 * @irq: the interrupt number
447 * @desc: the interrupt description structure for this irq
449 * Interrupt occures on the falling and/or rising edge of a hardware
450 * signal. The occurence is latched into the irq controller hardware
451 * and must be acked in order to be reenabled. After the ack another
452 * interrupt can happen on the same source even before the first one
453 * is handled by the assosiacted event handler. If this happens it
454 * might be necessary to disable (mask) the interrupt depending on the
455 * controller hardware. This requires to reenable the interrupt inside
456 * of the loop which handles the interrupts which have arrived while
457 * the handler was running. If all pending interrupts are handled, the
461 handle_edge_irq(unsigned int irq
, struct irq_desc
*desc
)
463 const unsigned int cpu
= smp_processor_id();
465 spin_lock(&desc
->lock
);
467 desc
->status
&= ~(IRQ_REPLAY
| IRQ_WAITING
);
470 * If we're currently running this IRQ, or its disabled,
471 * we shouldn't process the IRQ. Mark it pending, handle
472 * the necessary masking and go out
474 if (unlikely((desc
->status
& (IRQ_INPROGRESS
| IRQ_DISABLED
)) ||
476 desc
->status
|= (IRQ_PENDING
| IRQ_MASKED
);
477 mask_ack_irq(desc
, irq
);
481 kstat_cpu(cpu
).irqs
[irq
]++;
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
);
526 * handle_percpu_IRQ - Per CPU local irq handler
527 * @irq: the interrupt number
528 * @desc: the interrupt description structure for this irq
530 * Per CPU interrupts on SMP machines without locking requirements
533 handle_percpu_irq(unsigned int irq
, struct irq_desc
*desc
)
535 irqreturn_t action_ret
;
537 kstat_this_cpu
.irqs
[irq
]++;
540 desc
->chip
->ack(irq
);
542 action_ret
= handle_IRQ_event(irq
, desc
->action
);
544 note_interrupt(irq
, desc
, action_ret
);
547 desc
->chip
->eoi(irq
);
550 #endif /* CONFIG_SMP */
553 __set_irq_handler(unsigned int irq
, irq_flow_handler_t handle
, int is_chained
,
556 struct irq_desc
*desc
;
559 if (irq
>= NR_IRQS
) {
561 "Trying to install type control for IRQ%d\n", irq
);
565 desc
= irq_desc
+ irq
;
568 handle
= handle_bad_irq
;
569 else if (desc
->chip
== &no_irq_chip
) {
570 printk(KERN_WARNING
"Trying to install %sinterrupt handler "
571 "for IRQ%d\n", is_chained
? "chained " : "", irq
);
573 * Some ARM implementations install a handler for really dumb
574 * interrupt hardware without setting an irq_chip. This worked
575 * with the ARM no_irq_chip but the check in setup_irq would
576 * prevent us to setup the interrupt at all. Switch it to
577 * dummy_irq_chip for easy transition.
579 desc
->chip
= &dummy_irq_chip
;
582 spin_lock_irqsave(&desc
->lock
, flags
);
585 if (handle
== handle_bad_irq
) {
586 if (desc
->chip
!= &no_irq_chip
)
587 mask_ack_irq(desc
, irq
);
588 desc
->status
|= IRQ_DISABLED
;
591 desc
->handle_irq
= handle
;
594 if (handle
!= handle_bad_irq
&& is_chained
) {
595 desc
->status
&= ~IRQ_DISABLED
;
596 desc
->status
|= IRQ_NOREQUEST
| IRQ_NOPROBE
;
598 desc
->chip
->unmask(irq
);
600 spin_unlock_irqrestore(&desc
->lock
, flags
);
604 set_irq_chip_and_handler(unsigned int irq
, struct irq_chip
*chip
,
605 irq_flow_handler_t handle
)
607 set_irq_chip(irq
, chip
);
608 __set_irq_handler(irq
, handle
, 0, NULL
);
612 set_irq_chip_and_handler_name(unsigned int irq
, struct irq_chip
*chip
,
613 irq_flow_handler_t handle
, const char *name
)
615 set_irq_chip(irq
, chip
);
616 __set_irq_handler(irq
, handle
, 0, name
);