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>
18 #include <linux/rculist.h>
19 #include <linux/hash.h>
20 #include <linux/bootmem.h>
22 #define CREATE_TRACE_POINTS
23 #include <trace/events/irq.h>
25 #include "internals.h"
28 * lockdep: we want to handle all irq_desc locks as a single lock-class:
30 struct lock_class_key irq_desc_lock_class
;
33 * handle_bad_irq - handle spurious and unhandled irqs
34 * @irq: the interrupt number
35 * @desc: description of the interrupt
37 * Handles spurious and unhandled IRQ's. It also prints a debugmessage.
39 void handle_bad_irq(unsigned int irq
, struct irq_desc
*desc
)
41 print_irq_desc(irq
, desc
);
42 kstat_incr_irqs_this_cpu(irq
, desc
);
46 #if defined(CONFIG_SMP) && defined(CONFIG_GENERIC_HARDIRQS)
47 static void __init
init_irq_default_affinity(void)
49 alloc_bootmem_cpumask_var(&irq_default_affinity
);
50 cpumask_setall(irq_default_affinity
);
53 static void __init
init_irq_default_affinity(void)
59 * Linux has a controller-independent interrupt architecture.
60 * Every controller has a 'controller-template', that is used
61 * by the main code to do the right thing. Each driver-visible
62 * interrupt source is transparently wired to the appropriate
63 * controller. Thus drivers need not be aware of the
64 * interrupt-controller.
66 * The code is designed to be easily extended with new/different
67 * interrupt controllers, without having to do assembly magic or
68 * having to touch the generic code.
70 * Controller mappings for all interrupt sources:
72 int nr_irqs
= NR_IRQS
;
73 EXPORT_SYMBOL_GPL(nr_irqs
);
75 #ifdef CONFIG_SPARSE_IRQ
77 static struct irq_desc irq_desc_init
= {
79 .status
= IRQ_DISABLED
,
81 .handle_irq
= handle_bad_irq
,
83 .lock
= __SPIN_LOCK_UNLOCKED(irq_desc_init
.lock
),
86 void init_kstat_irqs(struct irq_desc
*desc
, int cpu
, int nr
)
91 node
= cpu_to_node(cpu
);
92 ptr
= kzalloc_node(nr
* sizeof(*desc
->kstat_irqs
), GFP_ATOMIC
, node
);
95 * don't overwite if can not get new one
96 * init_copy_kstat_irqs() could still use old one
99 printk(KERN_DEBUG
" alloc kstat_irqs on cpu %d node %d\n",
101 desc
->kstat_irqs
= ptr
;
105 static void init_one_irq_desc(int irq
, struct irq_desc
*desc
, int cpu
)
107 memcpy(desc
, &irq_desc_init
, sizeof(struct irq_desc
));
109 spin_lock_init(&desc
->lock
);
114 lockdep_set_class(&desc
->lock
, &irq_desc_lock_class
);
115 init_kstat_irqs(desc
, cpu
, nr_cpu_ids
);
116 if (!desc
->kstat_irqs
) {
117 printk(KERN_ERR
"can not alloc kstat_irqs\n");
120 if (!init_alloc_desc_masks(desc
, cpu
, false)) {
121 printk(KERN_ERR
"can not alloc irq_desc cpumasks\n");
124 arch_init_chip_data(desc
, cpu
);
128 * Protect the sparse_irqs:
130 DEFINE_SPINLOCK(sparse_irq_lock
);
132 struct irq_desc
**irq_desc_ptrs __read_mostly
;
134 static struct irq_desc irq_desc_legacy
[NR_IRQS_LEGACY
] __cacheline_aligned_in_smp
= {
135 [0 ... NR_IRQS_LEGACY
-1] = {
137 .status
= IRQ_DISABLED
,
138 .chip
= &no_irq_chip
,
139 .handle_irq
= handle_bad_irq
,
141 .lock
= __SPIN_LOCK_UNLOCKED(irq_desc_init
.lock
),
145 static unsigned int *kstat_irqs_legacy
;
147 int __init
early_irq_init(void)
149 struct irq_desc
*desc
;
153 init_irq_default_affinity();
155 /* initialize nr_irqs based on nr_cpu_ids */
156 arch_probe_nr_irqs();
157 printk(KERN_INFO
"NR_IRQS:%d nr_irqs:%d\n", NR_IRQS
, nr_irqs
);
159 desc
= irq_desc_legacy
;
160 legacy_count
= ARRAY_SIZE(irq_desc_legacy
);
162 /* allocate irq_desc_ptrs array based on nr_irqs */
163 irq_desc_ptrs
= alloc_bootmem(nr_irqs
* sizeof(void *));
165 /* allocate based on nr_cpu_ids */
166 /* FIXME: invert kstat_irgs, and it'd be a per_cpu_alloc'd thing */
167 kstat_irqs_legacy
= alloc_bootmem(NR_IRQS_LEGACY
* nr_cpu_ids
*
170 for (i
= 0; i
< legacy_count
; i
++) {
172 desc
[i
].kstat_irqs
= kstat_irqs_legacy
+ i
* nr_cpu_ids
;
173 lockdep_set_class(&desc
[i
].lock
, &irq_desc_lock_class
);
174 init_alloc_desc_masks(&desc
[i
], 0, true);
175 irq_desc_ptrs
[i
] = desc
+ i
;
178 for (i
= legacy_count
; i
< nr_irqs
; i
++)
179 irq_desc_ptrs
[i
] = NULL
;
181 return arch_early_irq_init();
184 struct irq_desc
*irq_to_desc(unsigned int irq
)
186 if (irq_desc_ptrs
&& irq
< nr_irqs
)
187 return irq_desc_ptrs
[irq
];
192 struct irq_desc
*irq_to_desc_alloc_cpu(unsigned int irq
, int cpu
)
194 struct irq_desc
*desc
;
198 if (irq
>= nr_irqs
) {
199 WARN(1, "irq (%d) >= nr_irqs (%d) in irq_to_desc_alloc\n",
204 desc
= irq_desc_ptrs
[irq
];
208 spin_lock_irqsave(&sparse_irq_lock
, flags
);
210 /* We have to check it to avoid races with another CPU */
211 desc
= irq_desc_ptrs
[irq
];
215 node
= cpu_to_node(cpu
);
216 desc
= kzalloc_node(sizeof(*desc
), GFP_ATOMIC
, node
);
217 printk(KERN_DEBUG
" alloc irq_desc for %d on cpu %d node %d\n",
220 printk(KERN_ERR
"can not alloc irq_desc\n");
223 init_one_irq_desc(irq
, desc
, cpu
);
225 irq_desc_ptrs
[irq
] = desc
;
228 spin_unlock_irqrestore(&sparse_irq_lock
, flags
);
233 #else /* !CONFIG_SPARSE_IRQ */
235 struct irq_desc irq_desc
[NR_IRQS
] __cacheline_aligned_in_smp
= {
236 [0 ... NR_IRQS
-1] = {
237 .status
= IRQ_DISABLED
,
238 .chip
= &no_irq_chip
,
239 .handle_irq
= handle_bad_irq
,
241 .lock
= __SPIN_LOCK_UNLOCKED(irq_desc
->lock
),
245 static unsigned int kstat_irqs_all
[NR_IRQS
][NR_CPUS
];
246 int __init
early_irq_init(void)
248 struct irq_desc
*desc
;
252 init_irq_default_affinity();
254 printk(KERN_INFO
"NR_IRQS:%d\n", NR_IRQS
);
257 count
= ARRAY_SIZE(irq_desc
);
259 for (i
= 0; i
< count
; i
++) {
261 init_alloc_desc_masks(&desc
[i
], 0, true);
262 desc
[i
].kstat_irqs
= kstat_irqs_all
[i
];
264 return arch_early_irq_init();
267 struct irq_desc
*irq_to_desc(unsigned int irq
)
269 return (irq
< NR_IRQS
) ? irq_desc
+ irq
: NULL
;
272 struct irq_desc
*irq_to_desc_alloc_cpu(unsigned int irq
, int cpu
)
274 return irq_to_desc(irq
);
276 #endif /* !CONFIG_SPARSE_IRQ */
278 void clear_kstat_irqs(struct irq_desc
*desc
)
280 memset(desc
->kstat_irqs
, 0, nr_cpu_ids
* sizeof(*(desc
->kstat_irqs
)));
284 * What should we do if we get a hw irq event on an illegal vector?
285 * Each architecture has to answer this themself.
287 static void ack_bad(unsigned int irq
)
289 struct irq_desc
*desc
= irq_to_desc(irq
);
291 print_irq_desc(irq
, desc
);
298 static void noop(unsigned int irq
)
302 static unsigned int noop_ret(unsigned int irq
)
308 * Generic no controller implementation
310 struct irq_chip no_irq_chip
= {
321 * Generic dummy implementation which can be used for
322 * real dumb interrupt sources
324 struct irq_chip dummy_irq_chip
= {
337 * Special, empty irq handler:
339 irqreturn_t
no_action(int cpl
, void *dev_id
)
344 static void warn_no_thread(unsigned int irq
, struct irqaction
*action
)
346 if (test_and_set_bit(IRQTF_WARNED
, &action
->thread_flags
))
349 printk(KERN_WARNING
"IRQ %d device %s returned IRQ_WAKE_THREAD "
350 "but no thread function available.", irq
, action
->name
);
354 * handle_IRQ_event - irq action chain handler
355 * @irq: the interrupt number
356 * @action: the interrupt action chain for this irq
358 * Handles the action chain of an irq event
360 irqreturn_t
handle_IRQ_event(unsigned int irq
, struct irqaction
*action
)
362 irqreturn_t ret
, retval
= IRQ_NONE
;
363 unsigned int status
= 0;
365 WARN_ONCE(!in_irq(), "BUG: IRQ handler called from non-hardirq context!");
367 if (!(action
->flags
& IRQF_DISABLED
))
368 local_irq_enable_in_hardirq();
371 trace_irq_handler_entry(irq
, action
);
372 ret
= action
->handler(irq
, action
->dev_id
);
373 trace_irq_handler_exit(irq
, action
, ret
);
376 case IRQ_WAKE_THREAD
:
378 * Set result to handled so the spurious check
384 * Catch drivers which return WAKE_THREAD but
385 * did not set up a thread function
387 if (unlikely(!action
->thread_fn
)) {
388 warn_no_thread(irq
, action
);
393 * Wake up the handler thread for this
394 * action. In case the thread crashed and was
395 * killed we just pretend that we handled the
396 * interrupt. The hardirq handler above has
397 * disabled the device interrupt, so no irq
400 if (likely(!test_bit(IRQTF_DIED
,
401 &action
->thread_flags
))) {
402 set_bit(IRQTF_RUNTHREAD
, &action
->thread_flags
);
403 wake_up_process(action
->thread
);
406 /* Fall through to add to randomness */
408 status
|= action
->flags
;
416 action
= action
->next
;
419 if (status
& IRQF_SAMPLE_RANDOM
)
420 add_interrupt_randomness(irq
);
426 #ifndef CONFIG_GENERIC_HARDIRQS_NO__DO_IRQ
428 #ifdef CONFIG_ENABLE_WARN_DEPRECATED
429 # warning __do_IRQ is deprecated. Please convert to proper flow handlers
433 * __do_IRQ - original all in one highlevel IRQ handler
434 * @irq: the interrupt number
436 * __do_IRQ handles all normal device IRQ's (the special
437 * SMP cross-CPU interrupts have their own specific
440 * This is the original x86 implementation which is used for every
443 unsigned int __do_IRQ(unsigned int irq
)
445 struct irq_desc
*desc
= irq_to_desc(irq
);
446 struct irqaction
*action
;
449 kstat_incr_irqs_this_cpu(irq
, desc
);
451 if (CHECK_IRQ_PER_CPU(desc
->status
)) {
452 irqreturn_t action_ret
;
455 * No locking required for CPU-local interrupts:
457 if (desc
->chip
->ack
) {
458 desc
->chip
->ack(irq
);
460 desc
= irq_remap_to_desc(irq
, desc
);
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
);
472 if (desc
->chip
->ack
) {
473 desc
->chip
->ack(irq
);
474 desc
= irq_remap_to_desc(irq
, desc
);
477 * REPLAY is when Linux resends an IRQ that was dropped earlier
478 * WAITING is used by probe to mark irqs that are being tested
480 status
= desc
->status
& ~(IRQ_REPLAY
| IRQ_WAITING
);
481 status
|= IRQ_PENDING
; /* we _want_ to handle it */
484 * If the IRQ is disabled for whatever reason, we cannot
485 * use the action we have.
488 if (likely(!(status
& (IRQ_DISABLED
| IRQ_INPROGRESS
)))) {
489 action
= desc
->action
;
490 status
&= ~IRQ_PENDING
; /* we commit to handling */
491 status
|= IRQ_INPROGRESS
; /* we are handling it */
493 desc
->status
= status
;
496 * If there is no IRQ handler or it was disabled, exit early.
497 * Since we set PENDING, if another processor is handling
498 * a different instance of this same irq, the other processor
499 * will take care of it.
501 if (unlikely(!action
))
505 * Edge triggered interrupts need to remember
507 * This applies to any hw interrupts that allow a second
508 * instance of the same irq to arrive while we are in do_IRQ
509 * or in the handler. But the code here only handles the _second_
510 * instance of the irq, not the third or fourth. So it is mostly
511 * useful for irq hardware that does not mask cleanly in an
515 irqreturn_t action_ret
;
517 spin_unlock(&desc
->lock
);
519 action_ret
= handle_IRQ_event(irq
, action
);
521 note_interrupt(irq
, desc
, action_ret
);
523 spin_lock(&desc
->lock
);
524 if (likely(!(desc
->status
& IRQ_PENDING
)))
526 desc
->status
&= ~IRQ_PENDING
;
528 desc
->status
&= ~IRQ_INPROGRESS
;
532 * The ->end() handler has to deal with interrupts which got
533 * disabled while the handler was running.
535 desc
->chip
->end(irq
);
536 spin_unlock(&desc
->lock
);
542 void early_init_irq_lock_class(void)
544 struct irq_desc
*desc
;
547 for_each_irq_desc(i
, desc
) {
548 lockdep_set_class(&desc
->lock
, &irq_desc_lock_class
);
552 unsigned int kstat_irqs_cpu(unsigned int irq
, int cpu
)
554 struct irq_desc
*desc
= irq_to_desc(irq
);
555 return desc
? desc
->kstat_irqs
[cpu
] : 0;
557 EXPORT_SYMBOL(kstat_irqs_cpu
);