2 * linux/kernel/irq/handle.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.
9 * Detailed information is available in Documentation/DocBook/genericirq
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>
19 #include "internals.h"
21 #ifdef CONFIG_TRACE_IRQFLAGS
24 * lockdep: we want to handle all irq_desc locks as a single lock-class:
26 static struct lock_class_key irq_desc_lock_class
;
30 * handle_bad_irq - handle spurious and unhandled irqs
31 * @irq: the interrupt number
32 * @desc: description of the interrupt
34 * Handles spurious and unhandled IRQ's. It also prints a debugmessage.
37 handle_bad_irq(unsigned int irq
, struct irq_desc
*desc
)
39 print_irq_desc(irq
, desc
);
40 kstat_irqs_this_cpu(desc
)++;
45 * Linux has a controller-independent interrupt architecture.
46 * Every controller has a 'controller-template', that is used
47 * by the main code to do the right thing. Each driver-visible
48 * interrupt source is transparently wired to the appropriate
49 * controller. Thus drivers need not be aware of the
50 * interrupt-controller.
52 * The code is designed to be easily extended with new/different
53 * interrupt controllers, without having to do assembly magic or
54 * having to touch the generic code.
56 * Controller mappings for all interrupt sources:
58 int nr_irqs
= NR_IRQS
;
59 EXPORT_SYMBOL_GPL(nr_irqs
);
61 #ifdef CONFIG_HAVE_DYN_ARRAY
62 static struct irq_desc irq_desc_init
= {
64 .status
= IRQ_DISABLED
,
66 .handle_irq
= handle_bad_irq
,
68 .lock
= __SPIN_LOCK_UNLOCKED(irq_desc_init
.lock
),
70 .affinity
= CPU_MASK_ALL
75 static void init_one_irq_desc(struct irq_desc
*desc
)
77 memcpy(desc
, &irq_desc_init
, sizeof(struct irq_desc
));
78 #ifdef CONFIG_TRACE_IRQFLAGS
79 lockdep_set_class(&desc
->lock
, &irq_desc_lock_class
);
83 extern int after_bootmem
;
84 extern void *__alloc_bootmem_nopanic(unsigned long size
,
88 static void init_kstat_irqs(struct irq_desc
*desc
, int nr_desc
, int nr
)
90 unsigned long bytes
, total_bytes
;
95 /* Compute how many bytes we need per irq and allocate them */
96 bytes
= nr
* sizeof(unsigned int);
97 total_bytes
= bytes
* nr_desc
;
99 ptr
= kzalloc(total_bytes
, GFP_ATOMIC
);
101 ptr
= __alloc_bootmem_nopanic(total_bytes
, PAGE_SIZE
, 0);
104 panic(" can not allocate kstat_irqs\n");
107 printk(KERN_DEBUG
"kstat_irqs ==> [%#lx - %#lx]\n", phys
, phys
+ total_bytes
);
109 for (i
= 0; i
< nr_desc
; i
++) {
110 desc
[i
].kstat_irqs
= (unsigned int *)ptr
;
115 static void __init
init_work(void *data
)
117 struct dyn_array
*da
= data
;
119 struct irq_desc
*desc
;
123 for (i
= 0; i
< *da
->nr
; i
++) {
124 init_one_irq_desc(&desc
[i
]);
125 #ifndef CONFIG_HAVE_SPARSE_IRQ
130 #ifdef CONFIG_HAVE_SPARSE_IRQ
131 for (i
= 1; i
< *da
->nr
; i
++)
132 desc
[i
-1].next
= &desc
[i
];
135 /* init kstat_irqs, nr_cpu_ids is ready already */
136 init_kstat_irqs(desc
, *da
->nr
, nr_cpu_ids
);
139 #ifdef CONFIG_HAVE_SPARSE_IRQ
140 static int nr_irq_desc
= 32;
142 static int __init
parse_nr_irq_desc(char *arg
)
145 nr_irq_desc
= simple_strtoul(arg
, NULL
, 0);
149 early_param("nr_irq_desc", parse_nr_irq_desc
);
151 struct irq_desc
*sparse_irqs
;
152 DEFINE_DYN_ARRAY(sparse_irqs
, sizeof(struct irq_desc
), nr_irq_desc
, PAGE_SIZE
, init_work
);
154 struct irq_desc
*irq_to_desc(unsigned int irq
)
156 struct irq_desc
*desc
;
160 desc
= &sparse_irqs
[0];
162 if (desc
->irq
== irq
)
165 if (desc
->irq
== -1U)
172 struct irq_desc
*irq_to_desc_alloc(unsigned int irq
)
174 struct irq_desc
*desc
, *desc_pri
;
178 unsigned long total_bytes
;
182 desc_pri
= desc
= &sparse_irqs
[0];
184 if (desc
->irq
== irq
)
187 if (desc
->irq
== -1U) {
189 printk(KERN_DEBUG
"found new irq_desc for irq %d\n", desc
->irq
);
198 * we run out of pre-allocate ones, allocate more
200 printk(KERN_DEBUG
"try to get more irq_desc %d\n", nr_irq_desc
);
202 /* double check if some one mess up the list */
203 struct irq_desc
*desc
;
206 desc
= &sparse_irqs
[0];
208 printk(KERN_DEBUG
"found irq_desc for irq %d\n", desc
->irq
);
210 printk(KERN_DEBUG
"found irq_desc for irq %d and next will be irq %d\n", desc
->irq
, desc
->next
->irq
);
214 printk(KERN_DEBUG
"all preallocted %d\n", count
);
217 total_bytes
= sizeof(struct irq_desc
) * nr_irq_desc
;
219 desc
= kzalloc(total_bytes
, GFP_ATOMIC
);
221 desc
= __alloc_bootmem_nopanic(total_bytes
, PAGE_SIZE
, 0);
224 panic("please boot with nr_irq_desc= %d\n", count
* 2);
227 printk(KERN_DEBUG
"irq_desc ==> [%#lx - %#lx]\n", phys
, phys
+ total_bytes
);
229 for (i
= 0; i
< nr_irq_desc
; i
++)
230 init_one_irq_desc(&desc
[i
]);
232 for (i
= 1; i
< nr_irq_desc
; i
++)
233 desc
[i
-1].next
= &desc
[i
];
235 /* init kstat_irqs, nr_cpu_ids is ready already */
236 init_kstat_irqs(desc
, nr_irq_desc
, nr_cpu_ids
);
239 desc_pri
->next
= desc
;
240 printk(KERN_DEBUG
"1 found new irq_desc for irq %d and pri will be irq %d\n", desc
->irq
, desc_pri
->irq
);
245 struct irq_desc
*irq_desc
;
246 DEFINE_DYN_ARRAY(irq_desc
, sizeof(struct irq_desc
), nr_irqs
, PAGE_SIZE
, init_work
);
252 struct irq_desc irq_desc
[NR_IRQS
] __cacheline_aligned_in_smp
= {
253 [0 ... NR_IRQS
-1] = {
254 .status
= IRQ_DISABLED
,
255 .chip
= &no_irq_chip
,
256 .handle_irq
= handle_bad_irq
,
258 .lock
= __SPIN_LOCK_UNLOCKED(sparse_irqs
->lock
),
260 .affinity
= CPU_MASK_ALL
267 #ifndef CONFIG_HAVE_SPARSE_IRQ
268 struct irq_desc
*irq_to_desc(unsigned int irq
)
271 return &irq_desc
[irq
];
275 struct irq_desc
*irq_to_desc_alloc(unsigned int irq
)
277 return irq_to_desc(irq
);
282 * What should we do if we get a hw irq event on an illegal vector?
283 * Each architecture has to answer this themself.
285 static void ack_bad(unsigned int irq
)
287 struct irq_desc
*desc
;
289 desc
= irq_to_desc(irq
);
290 print_irq_desc(irq
, desc
);
297 static void noop(unsigned int irq
)
301 static unsigned int noop_ret(unsigned int irq
)
307 * Generic no controller implementation
309 struct irq_chip no_irq_chip
= {
320 * Generic dummy implementation which can be used for
321 * real dumb interrupt sources
323 struct irq_chip dummy_irq_chip
= {
336 * Special, empty irq handler:
338 irqreturn_t
no_action(int cpl
, void *dev_id
)
344 * handle_IRQ_event - irq action chain handler
345 * @irq: the interrupt number
346 * @action: the interrupt action chain for this irq
348 * Handles the action chain of an irq event
350 irqreturn_t
handle_IRQ_event(unsigned int irq
, struct irqaction
*action
)
352 irqreturn_t ret
, retval
= IRQ_NONE
;
353 unsigned int status
= 0;
355 if (!(action
->flags
& IRQF_DISABLED
))
356 local_irq_enable_in_hardirq();
359 ret
= action
->handler(irq
, action
->dev_id
);
360 if (ret
== IRQ_HANDLED
)
361 status
|= action
->flags
;
363 action
= action
->next
;
366 if (status
& IRQF_SAMPLE_RANDOM
)
367 add_interrupt_randomness(irq
);
373 #ifndef CONFIG_GENERIC_HARDIRQS_NO__DO_IRQ
375 * __do_IRQ - original all in one highlevel IRQ handler
376 * @irq: the interrupt number
378 * __do_IRQ handles all normal device IRQ's (the special
379 * SMP cross-CPU interrupts have their own specific
382 * This is the original x86 implementation which is used for every
385 unsigned int __do_IRQ(unsigned int irq
)
387 struct irq_desc
*desc
= irq_to_desc(irq
);
388 struct irqaction
*action
;
391 kstat_irqs_this_cpu(desc
)++;
392 if (CHECK_IRQ_PER_CPU(desc
->status
)) {
393 irqreturn_t action_ret
;
396 * No locking required for CPU-local interrupts:
399 desc
->chip
->ack(irq
);
400 if (likely(!(desc
->status
& IRQ_DISABLED
))) {
401 action_ret
= handle_IRQ_event(irq
, desc
->action
);
403 note_interrupt(irq
, desc
, action_ret
);
405 desc
->chip
->end(irq
);
409 spin_lock(&desc
->lock
);
411 desc
->chip
->ack(irq
);
413 * REPLAY is when Linux resends an IRQ that was dropped earlier
414 * WAITING is used by probe to mark irqs that are being tested
416 status
= desc
->status
& ~(IRQ_REPLAY
| IRQ_WAITING
);
417 status
|= IRQ_PENDING
; /* we _want_ to handle it */
420 * If the IRQ is disabled for whatever reason, we cannot
421 * use the action we have.
424 if (likely(!(status
& (IRQ_DISABLED
| IRQ_INPROGRESS
)))) {
425 action
= desc
->action
;
426 status
&= ~IRQ_PENDING
; /* we commit to handling */
427 status
|= IRQ_INPROGRESS
; /* we are handling it */
429 desc
->status
= status
;
432 * If there is no IRQ handler or it was disabled, exit early.
433 * Since we set PENDING, if another processor is handling
434 * a different instance of this same irq, the other processor
435 * will take care of it.
437 if (unlikely(!action
))
441 * Edge triggered interrupts need to remember
443 * This applies to any hw interrupts that allow a second
444 * instance of the same irq to arrive while we are in do_IRQ
445 * or in the handler. But the code here only handles the _second_
446 * instance of the irq, not the third or fourth. So it is mostly
447 * useful for irq hardware that does not mask cleanly in an
451 irqreturn_t action_ret
;
453 spin_unlock(&desc
->lock
);
455 action_ret
= handle_IRQ_event(irq
, action
);
457 note_interrupt(irq
, desc
, action_ret
);
459 spin_lock(&desc
->lock
);
460 if (likely(!(desc
->status
& IRQ_PENDING
)))
462 desc
->status
&= ~IRQ_PENDING
;
464 desc
->status
&= ~IRQ_INPROGRESS
;
468 * The ->end() handler has to deal with interrupts which got
469 * disabled while the handler was running.
471 desc
->chip
->end(irq
);
472 spin_unlock(&desc
->lock
);
479 #ifdef CONFIG_TRACE_IRQFLAGS
480 void early_init_irq_lock_class(void)
482 #ifndef CONFIG_HAVE_DYN_ARRAY
485 for (i
= 0; i
< nr_irqs
; i
++)
486 lockdep_set_class(&irq_desc
[i
].lock
, &irq_desc_lock_class
);
491 unsigned int kstat_irqs_cpu(unsigned int irq
, int cpu
)
493 struct irq_desc
*desc
= irq_to_desc(irq
);
494 return desc
->kstat_irqs
[cpu
];
496 EXPORT_SYMBOL(kstat_irqs_cpu
);