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/slab.h>
15 #include <linux/module.h>
16 #include <linux/random.h>
17 #include <linux/interrupt.h>
18 #include <linux/kernel_stat.h>
19 #include <linux/rculist.h>
20 #include <linux/hash.h>
21 #include <linux/bootmem.h>
22 #include <trace/events/irq.h>
24 #include "internals.h"
27 * lockdep: we want to handle all irq_desc locks as a single lock-class:
29 struct lock_class_key irq_desc_lock_class
;
32 * handle_bad_irq - handle spurious and unhandled irqs
33 * @irq: the interrupt number
34 * @desc: description of the interrupt
36 * Handles spurious and unhandled IRQ's. It also prints a debugmessage.
38 void handle_bad_irq(unsigned int irq
, struct irq_desc
*desc
)
40 print_irq_desc(irq
, desc
);
41 kstat_incr_irqs_this_cpu(irq
, desc
);
45 #if defined(CONFIG_SMP) && defined(CONFIG_GENERIC_HARDIRQS)
46 static void __init
init_irq_default_affinity(void)
48 alloc_bootmem_cpumask_var(&irq_default_affinity
);
49 cpumask_setall(irq_default_affinity
);
52 static void __init
init_irq_default_affinity(void)
58 * Linux has a controller-independent interrupt architecture.
59 * Every controller has a 'controller-template', that is used
60 * by the main code to do the right thing. Each driver-visible
61 * interrupt source is transparently wired to the appropriate
62 * controller. Thus drivers need not be aware of the
63 * interrupt-controller.
65 * The code is designed to be easily extended with new/different
66 * interrupt controllers, without having to do assembly magic or
67 * having to touch the generic code.
69 * Controller mappings for all interrupt sources:
71 int nr_irqs
= NR_IRQS
;
72 EXPORT_SYMBOL_GPL(nr_irqs
);
74 #ifdef CONFIG_SPARSE_IRQ
76 static struct irq_desc irq_desc_init
= {
78 .status
= IRQ_DISABLED
,
80 .handle_irq
= handle_bad_irq
,
82 .lock
= __SPIN_LOCK_UNLOCKED(irq_desc_init
.lock
),
85 void __ref
init_kstat_irqs(struct irq_desc
*desc
, int node
, int nr
)
89 if (slab_is_available())
90 ptr
= kzalloc_node(nr
* sizeof(*desc
->kstat_irqs
),
93 ptr
= alloc_bootmem_node(NODE_DATA(node
),
94 nr
* sizeof(*desc
->kstat_irqs
));
97 * don't overwite if can not get new one
98 * init_copy_kstat_irqs() could still use old one
101 printk(KERN_DEBUG
" alloc kstat_irqs on node %d\n", node
);
102 desc
->kstat_irqs
= ptr
;
106 static void init_one_irq_desc(int irq
, struct irq_desc
*desc
, int node
)
108 memcpy(desc
, &irq_desc_init
, sizeof(struct irq_desc
));
110 spin_lock_init(&desc
->lock
);
115 lockdep_set_class(&desc
->lock
, &irq_desc_lock_class
);
116 init_kstat_irqs(desc
, node
, nr_cpu_ids
);
117 if (!desc
->kstat_irqs
) {
118 printk(KERN_ERR
"can not alloc kstat_irqs\n");
121 if (!alloc_desc_masks(desc
, node
, false)) {
122 printk(KERN_ERR
"can not alloc irq_desc cpumasks\n");
125 init_desc_masks(desc
);
126 arch_init_chip_data(desc
, node
);
130 * Protect the sparse_irqs:
132 DEFINE_SPINLOCK(sparse_irq_lock
);
134 struct irq_desc
**irq_desc_ptrs __read_mostly
;
136 static struct irq_desc irq_desc_legacy
[NR_IRQS_LEGACY
] __cacheline_aligned_in_smp
= {
137 [0 ... NR_IRQS_LEGACY
-1] = {
139 .status
= IRQ_DISABLED
,
140 .chip
= &no_irq_chip
,
141 .handle_irq
= handle_bad_irq
,
143 .lock
= __SPIN_LOCK_UNLOCKED(irq_desc_init
.lock
),
147 static unsigned int *kstat_irqs_legacy
;
149 int __init
early_irq_init(void)
151 struct irq_desc
*desc
;
155 init_irq_default_affinity();
157 /* initialize nr_irqs based on nr_cpu_ids */
158 arch_probe_nr_irqs();
159 printk(KERN_INFO
"NR_IRQS:%d nr_irqs:%d\n", NR_IRQS
, nr_irqs
);
161 desc
= irq_desc_legacy
;
162 legacy_count
= ARRAY_SIZE(irq_desc_legacy
);
164 /* allocate irq_desc_ptrs array based on nr_irqs */
165 irq_desc_ptrs
= alloc_bootmem(nr_irqs
* sizeof(void *));
167 /* allocate based on nr_cpu_ids */
168 /* FIXME: invert kstat_irgs, and it'd be a per_cpu_alloc'd thing */
169 kstat_irqs_legacy
= alloc_bootmem(NR_IRQS_LEGACY
* nr_cpu_ids
*
172 for (i
= 0; i
< legacy_count
; i
++) {
174 desc
[i
].kstat_irqs
= kstat_irqs_legacy
+ i
* nr_cpu_ids
;
175 lockdep_set_class(&desc
[i
].lock
, &irq_desc_lock_class
);
176 alloc_desc_masks(&desc
[i
], 0, true);
177 init_desc_masks(&desc
[i
]);
178 irq_desc_ptrs
[i
] = desc
+ i
;
181 for (i
= legacy_count
; i
< nr_irqs
; i
++)
182 irq_desc_ptrs
[i
] = NULL
;
184 return arch_early_irq_init();
187 struct irq_desc
*irq_to_desc(unsigned int irq
)
189 if (irq_desc_ptrs
&& irq
< nr_irqs
)
190 return irq_desc_ptrs
[irq
];
195 struct irq_desc
* __ref
irq_to_desc_alloc_node(unsigned int irq
, int node
)
197 struct irq_desc
*desc
;
200 if (irq
>= nr_irqs
) {
201 WARN(1, "irq (%d) >= nr_irqs (%d) in irq_to_desc_alloc\n",
206 desc
= irq_desc_ptrs
[irq
];
210 spin_lock_irqsave(&sparse_irq_lock
, flags
);
212 /* We have to check it to avoid races with another CPU */
213 desc
= irq_desc_ptrs
[irq
];
217 if (slab_is_available())
218 desc
= kzalloc_node(sizeof(*desc
), GFP_ATOMIC
, node
);
220 desc
= alloc_bootmem_node(NODE_DATA(node
), sizeof(*desc
));
222 printk(KERN_DEBUG
" alloc irq_desc for %d on node %d\n", irq
, node
);
224 printk(KERN_ERR
"can not alloc irq_desc\n");
227 init_one_irq_desc(irq
, desc
, node
);
229 irq_desc_ptrs
[irq
] = desc
;
232 spin_unlock_irqrestore(&sparse_irq_lock
, flags
);
237 #else /* !CONFIG_SPARSE_IRQ */
239 struct irq_desc irq_desc
[NR_IRQS
] __cacheline_aligned_in_smp
= {
240 [0 ... NR_IRQS
-1] = {
241 .status
= IRQ_DISABLED
,
242 .chip
= &no_irq_chip
,
243 .handle_irq
= handle_bad_irq
,
245 .lock
= __SPIN_LOCK_UNLOCKED(irq_desc
->lock
),
249 static unsigned int kstat_irqs_all
[NR_IRQS
][NR_CPUS
];
250 int __init
early_irq_init(void)
252 struct irq_desc
*desc
;
256 init_irq_default_affinity();
258 printk(KERN_INFO
"NR_IRQS:%d\n", NR_IRQS
);
261 count
= ARRAY_SIZE(irq_desc
);
263 for (i
= 0; i
< count
; i
++) {
265 alloc_desc_masks(&desc
[i
], 0, true);
266 init_desc_masks(&desc
[i
]);
267 desc
[i
].kstat_irqs
= kstat_irqs_all
[i
];
269 return arch_early_irq_init();
272 struct irq_desc
*irq_to_desc(unsigned int irq
)
274 return (irq
< NR_IRQS
) ? irq_desc
+ irq
: NULL
;
277 struct irq_desc
*irq_to_desc_alloc_node(unsigned int irq
, int node
)
279 return irq_to_desc(irq
);
281 #endif /* !CONFIG_SPARSE_IRQ */
283 void clear_kstat_irqs(struct irq_desc
*desc
)
285 memset(desc
->kstat_irqs
, 0, nr_cpu_ids
* sizeof(*(desc
->kstat_irqs
)));
289 * What should we do if we get a hw irq event on an illegal vector?
290 * Each architecture has to answer this themself.
292 static void ack_bad(unsigned int irq
)
294 struct irq_desc
*desc
= irq_to_desc(irq
);
296 print_irq_desc(irq
, desc
);
303 static void noop(unsigned int irq
)
307 static unsigned int noop_ret(unsigned int irq
)
313 * Generic no controller implementation
315 struct irq_chip no_irq_chip
= {
326 * Generic dummy implementation which can be used for
327 * real dumb interrupt sources
329 struct irq_chip dummy_irq_chip
= {
342 * Special, empty irq handler:
344 irqreturn_t
no_action(int cpl
, void *dev_id
)
349 static void warn_no_thread(unsigned int irq
, struct irqaction
*action
)
351 if (test_and_set_bit(IRQTF_WARNED
, &action
->thread_flags
))
354 printk(KERN_WARNING
"IRQ %d device %s returned IRQ_WAKE_THREAD "
355 "but no thread function available.", irq
, action
->name
);
359 * handle_IRQ_event - irq action chain handler
360 * @irq: the interrupt number
361 * @action: the interrupt action chain for this irq
363 * Handles the action chain of an irq event
365 irqreturn_t
handle_IRQ_event(unsigned int irq
, struct irqaction
*action
)
367 irqreturn_t ret
, retval
= IRQ_NONE
;
368 unsigned int status
= 0;
370 if (!(action
->flags
& IRQF_DISABLED
))
371 local_irq_enable_in_hardirq();
374 trace_irq_handler_entry(irq
, action
);
375 ret
= action
->handler(irq
, action
->dev_id
);
376 trace_irq_handler_exit(irq
, action
, ret
);
379 case IRQ_WAKE_THREAD
:
381 * Set result to handled so the spurious check
387 * Catch drivers which return WAKE_THREAD but
388 * did not set up a thread function
390 if (unlikely(!action
->thread_fn
)) {
391 warn_no_thread(irq
, action
);
396 * Wake up the handler thread for this
397 * action. In case the thread crashed and was
398 * killed we just pretend that we handled the
399 * interrupt. The hardirq handler above has
400 * disabled the device interrupt, so no irq
403 if (likely(!test_bit(IRQTF_DIED
,
404 &action
->thread_flags
))) {
405 set_bit(IRQTF_RUNTHREAD
, &action
->thread_flags
);
406 wake_up_process(action
->thread
);
409 /* Fall through to add to randomness */
411 status
|= action
->flags
;
419 action
= action
->next
;
422 if (status
& IRQF_SAMPLE_RANDOM
)
423 add_interrupt_randomness(irq
);
429 #ifndef CONFIG_GENERIC_HARDIRQS_NO__DO_IRQ
431 #ifdef CONFIG_ENABLE_WARN_DEPRECATED
432 # warning __do_IRQ is deprecated. Please convert to proper flow handlers
436 * __do_IRQ - original all in one highlevel IRQ handler
437 * @irq: the interrupt number
439 * __do_IRQ handles all normal device IRQ's (the special
440 * SMP cross-CPU interrupts have their own specific
443 * This is the original x86 implementation which is used for every
446 unsigned int __do_IRQ(unsigned int irq
)
448 struct irq_desc
*desc
= irq_to_desc(irq
);
449 struct irqaction
*action
;
452 kstat_incr_irqs_this_cpu(irq
, desc
);
454 if (CHECK_IRQ_PER_CPU(desc
->status
)) {
455 irqreturn_t action_ret
;
458 * No locking required for CPU-local interrupts:
461 desc
->chip
->ack(irq
);
462 if (likely(!(desc
->status
& IRQ_DISABLED
))) {
463 action_ret
= handle_IRQ_event(irq
, desc
->action
);
465 note_interrupt(irq
, desc
, action_ret
);
467 desc
->chip
->end(irq
);
471 spin_lock(&desc
->lock
);
473 desc
->chip
->ack(irq
);
475 * REPLAY is when Linux resends an IRQ that was dropped earlier
476 * WAITING is used by probe to mark irqs that are being tested
478 status
= desc
->status
& ~(IRQ_REPLAY
| IRQ_WAITING
);
479 status
|= IRQ_PENDING
; /* we _want_ to handle it */
482 * If the IRQ is disabled for whatever reason, we cannot
483 * use the action we have.
486 if (likely(!(status
& (IRQ_DISABLED
| IRQ_INPROGRESS
)))) {
487 action
= desc
->action
;
488 status
&= ~IRQ_PENDING
; /* we commit to handling */
489 status
|= IRQ_INPROGRESS
; /* we are handling it */
491 desc
->status
= status
;
494 * If there is no IRQ handler or it was disabled, exit early.
495 * Since we set PENDING, if another processor is handling
496 * a different instance of this same irq, the other processor
497 * will take care of it.
499 if (unlikely(!action
))
503 * Edge triggered interrupts need to remember
505 * This applies to any hw interrupts that allow a second
506 * instance of the same irq to arrive while we are in do_IRQ
507 * or in the handler. But the code here only handles the _second_
508 * instance of the irq, not the third or fourth. So it is mostly
509 * useful for irq hardware that does not mask cleanly in an
513 irqreturn_t action_ret
;
515 spin_unlock(&desc
->lock
);
517 action_ret
= handle_IRQ_event(irq
, action
);
519 note_interrupt(irq
, desc
, action_ret
);
521 spin_lock(&desc
->lock
);
522 if (likely(!(desc
->status
& IRQ_PENDING
)))
524 desc
->status
&= ~IRQ_PENDING
;
526 desc
->status
&= ~IRQ_INPROGRESS
;
530 * The ->end() handler has to deal with interrupts which got
531 * disabled while the handler was running.
533 desc
->chip
->end(irq
);
534 spin_unlock(&desc
->lock
);
540 void early_init_irq_lock_class(void)
542 struct irq_desc
*desc
;
545 for_each_irq_desc(i
, desc
) {
546 lockdep_set_class(&desc
->lock
, &irq_desc_lock_class
);
550 unsigned int kstat_irqs_cpu(unsigned int irq
, int cpu
)
552 struct irq_desc
*desc
= irq_to_desc(irq
);
553 return desc
? desc
->kstat_irqs
[cpu
] : 0;
555 EXPORT_SYMBOL(kstat_irqs_cpu
);