nvme: fix Kconfig description for BLK_DEV_NVME_SCSI
[linux-2.6-block.git] / kernel / irq / irqdesc.c
CommitLineData
3795de23
TG
1/*
2 * Copyright (C) 1992, 1998-2006 Linus Torvalds, Ingo Molnar
3 * Copyright (C) 2005-2006, Thomas Gleixner, Russell King
4 *
5 * This file contains the interrupt descriptor management code
6 *
7 * Detailed information is available in Documentation/DocBook/genericirq
8 *
9 */
10#include <linux/irq.h>
11#include <linux/slab.h>
ec53cf23 12#include <linux/export.h>
3795de23
TG
13#include <linux/interrupt.h>
14#include <linux/kernel_stat.h>
15#include <linux/radix-tree.h>
1f5a5b87 16#include <linux/bitmap.h>
76ba59f8 17#include <linux/irqdomain.h>
3795de23
TG
18
19#include "internals.h"
20
21/*
22 * lockdep: we want to handle all irq_desc locks as a single lock-class:
23 */
78f90d91 24static struct lock_class_key irq_desc_lock_class;
3795de23 25
fe051434 26#if defined(CONFIG_SMP)
3795de23
TG
27static void __init init_irq_default_affinity(void)
28{
29 alloc_cpumask_var(&irq_default_affinity, GFP_NOWAIT);
30 cpumask_setall(irq_default_affinity);
31}
32#else
33static void __init init_irq_default_affinity(void)
34{
35}
36#endif
37
1f5a5b87
TG
38#ifdef CONFIG_SMP
39static int alloc_masks(struct irq_desc *desc, gfp_t gfp, int node)
40{
9df872fa
JL
41 if (!zalloc_cpumask_var_node(&desc->irq_common_data.affinity,
42 gfp, node))
1f5a5b87
TG
43 return -ENOMEM;
44
45#ifdef CONFIG_GENERIC_PENDING_IRQ
46 if (!zalloc_cpumask_var_node(&desc->pending_mask, gfp, node)) {
9df872fa 47 free_cpumask_var(desc->irq_common_data.affinity);
1f5a5b87
TG
48 return -ENOMEM;
49 }
50#endif
51 return 0;
52}
53
54static void desc_smp_init(struct irq_desc *desc, int node)
55{
9df872fa 56 cpumask_copy(desc->irq_common_data.affinity, irq_default_affinity);
b7b29338
TG
57#ifdef CONFIG_GENERIC_PENDING_IRQ
58 cpumask_clear(desc->pending_mask);
59#endif
449e9cae
JL
60#ifdef CONFIG_NUMA
61 desc->irq_common_data.node = node;
62#endif
b7b29338
TG
63}
64
1f5a5b87
TG
65#else
66static inline int
67alloc_masks(struct irq_desc *desc, gfp_t gfp, int node) { return 0; }
68static inline void desc_smp_init(struct irq_desc *desc, int node) { }
69#endif
70
b6873807
SAS
71static void desc_set_defaults(unsigned int irq, struct irq_desc *desc, int node,
72 struct module *owner)
1f5a5b87 73{
6c9ae009
ED
74 int cpu;
75
af7080e0 76 desc->irq_common_data.handler_data = NULL;
b237721c 77 desc->irq_common_data.msi_desc = NULL;
af7080e0 78
0d0b4c86 79 desc->irq_data.common = &desc->irq_common_data;
1f5a5b87
TG
80 desc->irq_data.irq = irq;
81 desc->irq_data.chip = &no_irq_chip;
82 desc->irq_data.chip_data = NULL;
f9e4989e 83 irq_settings_clr_and_set(desc, ~0, _IRQ_DEFAULT_INIT_FLAGS);
801a0e9a 84 irqd_set(&desc->irq_data, IRQD_IRQ_DISABLED);
1f5a5b87
TG
85 desc->handle_irq = handle_bad_irq;
86 desc->depth = 1;
b7b29338
TG
87 desc->irq_count = 0;
88 desc->irqs_unhandled = 0;
1f5a5b87 89 desc->name = NULL;
b6873807 90 desc->owner = owner;
6c9ae009
ED
91 for_each_possible_cpu(cpu)
92 *per_cpu_ptr(desc->kstat_irqs, cpu) = 0;
1f5a5b87
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93 desc_smp_init(desc, node);
94}
95
3795de23
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96int nr_irqs = NR_IRQS;
97EXPORT_SYMBOL_GPL(nr_irqs);
98
a05a900a 99static DEFINE_MUTEX(sparse_irq_lock);
c1ee6264 100static DECLARE_BITMAP(allocated_irqs, IRQ_BITMAP_BITS);
1f5a5b87 101
3795de23
TG
102#ifdef CONFIG_SPARSE_IRQ
103
baa0d233 104static RADIX_TREE(irq_desc_tree, GFP_KERNEL);
3795de23 105
1f5a5b87 106static void irq_insert_desc(unsigned int irq, struct irq_desc *desc)
3795de23
TG
107{
108 radix_tree_insert(&irq_desc_tree, irq, desc);
109}
110
111struct irq_desc *irq_to_desc(unsigned int irq)
112{
113 return radix_tree_lookup(&irq_desc_tree, irq);
114}
3911ff30 115EXPORT_SYMBOL(irq_to_desc);
3795de23 116
1f5a5b87
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117static void delete_irq_desc(unsigned int irq)
118{
119 radix_tree_delete(&irq_desc_tree, irq);
120}
121
122#ifdef CONFIG_SMP
123static void free_masks(struct irq_desc *desc)
124{
125#ifdef CONFIG_GENERIC_PENDING_IRQ
126 free_cpumask_var(desc->pending_mask);
127#endif
9df872fa 128 free_cpumask_var(desc->irq_common_data.affinity);
1f5a5b87
TG
129}
130#else
131static inline void free_masks(struct irq_desc *desc) { }
132#endif
133
c291ee62
TG
134void irq_lock_sparse(void)
135{
136 mutex_lock(&sparse_irq_lock);
137}
138
139void irq_unlock_sparse(void)
140{
141 mutex_unlock(&sparse_irq_lock);
142}
143
b6873807 144static struct irq_desc *alloc_desc(int irq, int node, struct module *owner)
1f5a5b87
TG
145{
146 struct irq_desc *desc;
baa0d233 147 gfp_t gfp = GFP_KERNEL;
1f5a5b87
TG
148
149 desc = kzalloc_node(sizeof(*desc), gfp, node);
150 if (!desc)
151 return NULL;
152 /* allocate based on nr_cpu_ids */
6c9ae009 153 desc->kstat_irqs = alloc_percpu(unsigned int);
1f5a5b87
TG
154 if (!desc->kstat_irqs)
155 goto err_desc;
156
157 if (alloc_masks(desc, gfp, node))
158 goto err_kstat;
159
160 raw_spin_lock_init(&desc->lock);
161 lockdep_set_class(&desc->lock, &irq_desc_lock_class);
425a5072 162 init_rcu_head(&desc->rcu);
1f5a5b87 163
b6873807 164 desc_set_defaults(irq, desc, node, owner);
1f5a5b87
TG
165
166 return desc;
167
168err_kstat:
6c9ae009 169 free_percpu(desc->kstat_irqs);
1f5a5b87
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170err_desc:
171 kfree(desc);
172 return NULL;
173}
174
425a5072
TG
175static void delayed_free_desc(struct rcu_head *rhp)
176{
177 struct irq_desc *desc = container_of(rhp, struct irq_desc, rcu);
178
179 free_masks(desc);
180 free_percpu(desc->kstat_irqs);
181 kfree(desc);
182}
183
1f5a5b87
TG
184static void free_desc(unsigned int irq)
185{
186 struct irq_desc *desc = irq_to_desc(irq);
1f5a5b87 187
13bfe99e
TG
188 unregister_irq_proc(irq, desc);
189
c291ee62
TG
190 /*
191 * sparse_irq_lock protects also show_interrupts() and
192 * kstat_irq_usr(). Once we deleted the descriptor from the
193 * sparse tree we can free it. Access in proc will fail to
194 * lookup the descriptor.
195 */
a05a900a 196 mutex_lock(&sparse_irq_lock);
1f5a5b87 197 delete_irq_desc(irq);
a05a900a 198 mutex_unlock(&sparse_irq_lock);
1f5a5b87 199
425a5072
TG
200 /*
201 * We free the descriptor, masks and stat fields via RCU. That
202 * allows demultiplex interrupts to do rcu based management of
203 * the child interrupts.
204 */
205 call_rcu(&desc->rcu, delayed_free_desc);
1f5a5b87
TG
206}
207
b6873807
SAS
208static int alloc_descs(unsigned int start, unsigned int cnt, int node,
209 struct module *owner)
1f5a5b87
TG
210{
211 struct irq_desc *desc;
1f5a5b87
TG
212 int i;
213
214 for (i = 0; i < cnt; i++) {
b6873807 215 desc = alloc_desc(start + i, node, owner);
1f5a5b87
TG
216 if (!desc)
217 goto err;
a05a900a 218 mutex_lock(&sparse_irq_lock);
1f5a5b87 219 irq_insert_desc(start + i, desc);
a05a900a 220 mutex_unlock(&sparse_irq_lock);
1f5a5b87
TG
221 }
222 return start;
223
224err:
225 for (i--; i >= 0; i--)
226 free_desc(start + i);
227
a05a900a 228 mutex_lock(&sparse_irq_lock);
1f5a5b87 229 bitmap_clear(allocated_irqs, start, cnt);
a05a900a 230 mutex_unlock(&sparse_irq_lock);
1f5a5b87
TG
231 return -ENOMEM;
232}
233
ed4dea6e 234static int irq_expand_nr_irqs(unsigned int nr)
e7bcecb7 235{
ed4dea6e 236 if (nr > IRQ_BITMAP_BITS)
e7bcecb7 237 return -ENOMEM;
ed4dea6e 238 nr_irqs = nr;
e7bcecb7
TG
239 return 0;
240}
241
3795de23
TG
242int __init early_irq_init(void)
243{
b683de2b 244 int i, initcnt, node = first_online_node;
3795de23 245 struct irq_desc *desc;
3795de23
TG
246
247 init_irq_default_affinity();
248
b683de2b
TG
249 /* Let arch update nr_irqs and return the nr of preallocated irqs */
250 initcnt = arch_probe_nr_irqs();
251 printk(KERN_INFO "NR_IRQS:%d nr_irqs:%d %d\n", NR_IRQS, nr_irqs, initcnt);
3795de23 252
c1ee6264
TG
253 if (WARN_ON(nr_irqs > IRQ_BITMAP_BITS))
254 nr_irqs = IRQ_BITMAP_BITS;
255
256 if (WARN_ON(initcnt > IRQ_BITMAP_BITS))
257 initcnt = IRQ_BITMAP_BITS;
258
259 if (initcnt > nr_irqs)
260 nr_irqs = initcnt;
261
b683de2b 262 for (i = 0; i < initcnt; i++) {
b6873807 263 desc = alloc_desc(i, node, NULL);
aa99ec0f
TG
264 set_bit(i, allocated_irqs);
265 irq_insert_desc(i, desc);
3795de23 266 }
3795de23
TG
267 return arch_early_irq_init();
268}
269
3795de23
TG
270#else /* !CONFIG_SPARSE_IRQ */
271
272struct irq_desc irq_desc[NR_IRQS] __cacheline_aligned_in_smp = {
273 [0 ... NR_IRQS-1] = {
3795de23
TG
274 .handle_irq = handle_bad_irq,
275 .depth = 1,
276 .lock = __RAW_SPIN_LOCK_UNLOCKED(irq_desc->lock),
277 }
278};
279
3795de23
TG
280int __init early_irq_init(void)
281{
aa99ec0f 282 int count, i, node = first_online_node;
3795de23 283 struct irq_desc *desc;
3795de23
TG
284
285 init_irq_default_affinity();
286
287 printk(KERN_INFO "NR_IRQS:%d\n", NR_IRQS);
288
289 desc = irq_desc;
290 count = ARRAY_SIZE(irq_desc);
291
292 for (i = 0; i < count; i++) {
6c9ae009 293 desc[i].kstat_irqs = alloc_percpu(unsigned int);
e7fbad30
LW
294 alloc_masks(&desc[i], GFP_KERNEL, node);
295 raw_spin_lock_init(&desc[i].lock);
154cd387 296 lockdep_set_class(&desc[i].lock, &irq_desc_lock_class);
b6873807 297 desc_set_defaults(i, &desc[i], node, NULL);
3795de23
TG
298 }
299 return arch_early_irq_init();
300}
301
302struct irq_desc *irq_to_desc(unsigned int irq)
303{
304 return (irq < NR_IRQS) ? irq_desc + irq : NULL;
305}
2c45aada 306EXPORT_SYMBOL(irq_to_desc);
3795de23 307
1f5a5b87
TG
308static void free_desc(unsigned int irq)
309{
d8179bc0
TG
310 struct irq_desc *desc = irq_to_desc(irq);
311 unsigned long flags;
312
313 raw_spin_lock_irqsave(&desc->lock, flags);
6783011b 314 desc_set_defaults(irq, desc, irq_desc_get_node(desc), NULL);
d8179bc0 315 raw_spin_unlock_irqrestore(&desc->lock, flags);
1f5a5b87
TG
316}
317
b6873807
SAS
318static inline int alloc_descs(unsigned int start, unsigned int cnt, int node,
319 struct module *owner)
1f5a5b87 320{
b6873807
SAS
321 u32 i;
322
323 for (i = 0; i < cnt; i++) {
324 struct irq_desc *desc = irq_to_desc(start + i);
325
326 desc->owner = owner;
327 }
1f5a5b87
TG
328 return start;
329}
e7bcecb7 330
ed4dea6e 331static int irq_expand_nr_irqs(unsigned int nr)
e7bcecb7
TG
332{
333 return -ENOMEM;
334}
335
f63b6a05
TG
336void irq_mark_irq(unsigned int irq)
337{
338 mutex_lock(&sparse_irq_lock);
339 bitmap_set(allocated_irqs, irq, 1);
340 mutex_unlock(&sparse_irq_lock);
341}
342
c940e01c
TG
343#ifdef CONFIG_GENERIC_IRQ_LEGACY
344void irq_init_desc(unsigned int irq)
345{
d8179bc0 346 free_desc(irq);
c940e01c
TG
347}
348#endif
349
3795de23
TG
350#endif /* !CONFIG_SPARSE_IRQ */
351
fe12bc2c
TG
352/**
353 * generic_handle_irq - Invoke the handler for a particular irq
354 * @irq: The irq number to handle
355 *
356 */
357int generic_handle_irq(unsigned int irq)
358{
359 struct irq_desc *desc = irq_to_desc(irq);
360
361 if (!desc)
362 return -EINVAL;
bd0b9ac4 363 generic_handle_irq_desc(desc);
fe12bc2c
TG
364 return 0;
365}
edf76f83 366EXPORT_SYMBOL_GPL(generic_handle_irq);
fe12bc2c 367
76ba59f8
MZ
368#ifdef CONFIG_HANDLE_DOMAIN_IRQ
369/**
370 * __handle_domain_irq - Invoke the handler for a HW irq belonging to a domain
371 * @domain: The domain where to perform the lookup
372 * @hwirq: The HW irq number to convert to a logical one
373 * @lookup: Whether to perform the domain lookup or not
374 * @regs: Register file coming from the low-level handling code
375 *
376 * Returns: 0 on success, or -EINVAL if conversion has failed
377 */
378int __handle_domain_irq(struct irq_domain *domain, unsigned int hwirq,
379 bool lookup, struct pt_regs *regs)
380{
381 struct pt_regs *old_regs = set_irq_regs(regs);
382 unsigned int irq = hwirq;
383 int ret = 0;
384
385 irq_enter();
386
387#ifdef CONFIG_IRQ_DOMAIN
388 if (lookup)
389 irq = irq_find_mapping(domain, hwirq);
390#endif
391
392 /*
393 * Some hardware gives randomly wrong interrupts. Rather
394 * than crashing, do something sensible.
395 */
396 if (unlikely(!irq || irq >= nr_irqs)) {
397 ack_bad_irq(irq);
398 ret = -EINVAL;
399 } else {
400 generic_handle_irq(irq);
401 }
402
403 irq_exit();
404 set_irq_regs(old_regs);
405 return ret;
406}
407#endif
408
1f5a5b87
TG
409/* Dynamic interrupt handling */
410
411/**
412 * irq_free_descs - free irq descriptors
413 * @from: Start of descriptor range
414 * @cnt: Number of consecutive irqs to free
415 */
416void irq_free_descs(unsigned int from, unsigned int cnt)
417{
1f5a5b87
TG
418 int i;
419
420 if (from >= nr_irqs || (from + cnt) > nr_irqs)
421 return;
422
423 for (i = 0; i < cnt; i++)
424 free_desc(from + i);
425
a05a900a 426 mutex_lock(&sparse_irq_lock);
1f5a5b87 427 bitmap_clear(allocated_irqs, from, cnt);
a05a900a 428 mutex_unlock(&sparse_irq_lock);
1f5a5b87 429}
edf76f83 430EXPORT_SYMBOL_GPL(irq_free_descs);
1f5a5b87
TG
431
432/**
433 * irq_alloc_descs - allocate and initialize a range of irq descriptors
434 * @irq: Allocate for specific irq number if irq >= 0
435 * @from: Start the search from this irq number
436 * @cnt: Number of consecutive irqs to allocate.
437 * @node: Preferred node on which the irq descriptor should be allocated
d522a0d1 438 * @owner: Owning module (can be NULL)
1f5a5b87
TG
439 *
440 * Returns the first irq number or error code
441 */
442int __ref
b6873807
SAS
443__irq_alloc_descs(int irq, unsigned int from, unsigned int cnt, int node,
444 struct module *owner)
1f5a5b87 445{
1f5a5b87
TG
446 int start, ret;
447
448 if (!cnt)
449 return -EINVAL;
450
c5182b88
MB
451 if (irq >= 0) {
452 if (from > irq)
453 return -EINVAL;
454 from = irq;
62a08ae2
TG
455 } else {
456 /*
457 * For interrupts which are freely allocated the
458 * architecture can force a lower bound to the @from
459 * argument. x86 uses this to exclude the GSI space.
460 */
461 from = arch_dynirq_lower_bound(from);
c5182b88
MB
462 }
463
a05a900a 464 mutex_lock(&sparse_irq_lock);
1f5a5b87 465
ed4dea6e
YL
466 start = bitmap_find_next_zero_area(allocated_irqs, IRQ_BITMAP_BITS,
467 from, cnt, 0);
1f5a5b87
TG
468 ret = -EEXIST;
469 if (irq >=0 && start != irq)
470 goto err;
471
ed4dea6e
YL
472 if (start + cnt > nr_irqs) {
473 ret = irq_expand_nr_irqs(start + cnt);
e7bcecb7
TG
474 if (ret)
475 goto err;
476 }
1f5a5b87
TG
477
478 bitmap_set(allocated_irqs, start, cnt);
a05a900a 479 mutex_unlock(&sparse_irq_lock);
b6873807 480 return alloc_descs(start, cnt, node, owner);
1f5a5b87
TG
481
482err:
a05a900a 483 mutex_unlock(&sparse_irq_lock);
1f5a5b87
TG
484 return ret;
485}
b6873807 486EXPORT_SYMBOL_GPL(__irq_alloc_descs);
1f5a5b87 487
7b6ef126
TG
488#ifdef CONFIG_GENERIC_IRQ_LEGACY_ALLOC_HWIRQ
489/**
490 * irq_alloc_hwirqs - Allocate an irq descriptor and initialize the hardware
491 * @cnt: number of interrupts to allocate
492 * @node: node on which to allocate
493 *
494 * Returns an interrupt number > 0 or 0, if the allocation fails.
495 */
496unsigned int irq_alloc_hwirqs(int cnt, int node)
497{
498 int i, irq = __irq_alloc_descs(-1, 0, cnt, node, NULL);
499
500 if (irq < 0)
501 return 0;
502
503 for (i = irq; cnt > 0; i++, cnt--) {
504 if (arch_setup_hwirq(i, node))
505 goto err;
506 irq_clear_status_flags(i, _IRQ_NOREQUEST);
507 }
508 return irq;
509
510err:
511 for (i--; i >= irq; i--) {
512 irq_set_status_flags(i, _IRQ_NOREQUEST | _IRQ_NOPROBE);
513 arch_teardown_hwirq(i);
514 }
515 irq_free_descs(irq, cnt);
516 return 0;
517}
518EXPORT_SYMBOL_GPL(irq_alloc_hwirqs);
519
520/**
521 * irq_free_hwirqs - Free irq descriptor and cleanup the hardware
522 * @from: Free from irq number
523 * @cnt: number of interrupts to free
524 *
525 */
526void irq_free_hwirqs(unsigned int from, int cnt)
527{
8844aad8 528 int i, j;
7b6ef126 529
8844aad8 530 for (i = from, j = cnt; j > 0; i++, j--) {
7b6ef126
TG
531 irq_set_status_flags(i, _IRQ_NOREQUEST | _IRQ_NOPROBE);
532 arch_teardown_hwirq(i);
533 }
534 irq_free_descs(from, cnt);
535}
536EXPORT_SYMBOL_GPL(irq_free_hwirqs);
537#endif
538
a98d24b7
TG
539/**
540 * irq_get_next_irq - get next allocated irq number
541 * @offset: where to start the search
542 *
543 * Returns next irq number after offset or nr_irqs if none is found.
544 */
545unsigned int irq_get_next_irq(unsigned int offset)
546{
547 return find_next_bit(allocated_irqs, nr_irqs, offset);
548}
549
d5eb4ad2 550struct irq_desc *
31d9d9b6
MZ
551__irq_get_desc_lock(unsigned int irq, unsigned long *flags, bool bus,
552 unsigned int check)
d5eb4ad2
TG
553{
554 struct irq_desc *desc = irq_to_desc(irq);
555
556 if (desc) {
31d9d9b6
MZ
557 if (check & _IRQ_DESC_CHECK) {
558 if ((check & _IRQ_DESC_PERCPU) &&
559 !irq_settings_is_per_cpu_devid(desc))
560 return NULL;
561
562 if (!(check & _IRQ_DESC_PERCPU) &&
563 irq_settings_is_per_cpu_devid(desc))
564 return NULL;
565 }
566
d5eb4ad2
TG
567 if (bus)
568 chip_bus_lock(desc);
569 raw_spin_lock_irqsave(&desc->lock, *flags);
570 }
571 return desc;
572}
573
574void __irq_put_desc_unlock(struct irq_desc *desc, unsigned long flags, bool bus)
575{
576 raw_spin_unlock_irqrestore(&desc->lock, flags);
577 if (bus)
578 chip_bus_sync_unlock(desc);
579}
580
31d9d9b6
MZ
581int irq_set_percpu_devid(unsigned int irq)
582{
583 struct irq_desc *desc = irq_to_desc(irq);
584
585 if (!desc)
586 return -EINVAL;
587
588 if (desc->percpu_enabled)
589 return -EINVAL;
590
591 desc->percpu_enabled = kzalloc(sizeof(*desc->percpu_enabled), GFP_KERNEL);
592
593 if (!desc->percpu_enabled)
594 return -ENOMEM;
595
596 irq_set_percpu_devid_flags(irq);
597 return 0;
598}
599
792d0018
TG
600void kstat_incr_irq_this_cpu(unsigned int irq)
601{
b51bf95c 602 kstat_incr_irqs_this_cpu(irq_to_desc(irq));
792d0018
TG
603}
604
c291ee62
TG
605/**
606 * kstat_irqs_cpu - Get the statistics for an interrupt on a cpu
607 * @irq: The interrupt number
608 * @cpu: The cpu number
609 *
610 * Returns the sum of interrupt counts on @cpu since boot for
611 * @irq. The caller must ensure that the interrupt is not removed
612 * concurrently.
613 */
3795de23
TG
614unsigned int kstat_irqs_cpu(unsigned int irq, int cpu)
615{
616 struct irq_desc *desc = irq_to_desc(irq);
6c9ae009
ED
617
618 return desc && desc->kstat_irqs ?
619 *per_cpu_ptr(desc->kstat_irqs, cpu) : 0;
3795de23 620}
478735e3 621
c291ee62
TG
622/**
623 * kstat_irqs - Get the statistics for an interrupt
624 * @irq: The interrupt number
625 *
626 * Returns the sum of interrupt counts on all cpus since boot for
627 * @irq. The caller must ensure that the interrupt is not removed
628 * concurrently.
629 */
478735e3
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630unsigned int kstat_irqs(unsigned int irq)
631{
632 struct irq_desc *desc = irq_to_desc(irq);
633 int cpu;
5e9662fa 634 unsigned int sum = 0;
478735e3 635
6c9ae009 636 if (!desc || !desc->kstat_irqs)
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637 return 0;
638 for_each_possible_cpu(cpu)
6c9ae009 639 sum += *per_cpu_ptr(desc->kstat_irqs, cpu);
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640 return sum;
641}
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642
643/**
644 * kstat_irqs_usr - Get the statistics for an interrupt
645 * @irq: The interrupt number
646 *
647 * Returns the sum of interrupt counts on all cpus since boot for
648 * @irq. Contrary to kstat_irqs() this can be called from any
649 * preemptible context. It's protected against concurrent removal of
650 * an interrupt descriptor when sparse irqs are enabled.
651 */
652unsigned int kstat_irqs_usr(unsigned int irq)
653{
7df0b278 654 unsigned int sum;
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655
656 irq_lock_sparse();
657 sum = kstat_irqs(irq);
658 irq_unlock_sparse();
659 return sum;
660}