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v3.15
 
  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>
 12#include <linux/export.h>
 13#include <linux/interrupt.h>
 14#include <linux/kernel_stat.h>
 15#include <linux/radix-tree.h>
 16#include <linux/bitmap.h>
 
 
 17
 18#include "internals.h"
 19
 20/*
 21 * lockdep: we want to handle all irq_desc locks as a single lock-class:
 22 */
 23static struct lock_class_key irq_desc_lock_class;
 24
 25#if defined(CONFIG_SMP)
 
 
 
 
 
 
 
 
 
 
 
 
 
 26static void __init init_irq_default_affinity(void)
 27{
 28	alloc_cpumask_var(&irq_default_affinity, GFP_NOWAIT);
 29	cpumask_setall(irq_default_affinity);
 
 
 30}
 31#else
 32static void __init init_irq_default_affinity(void)
 33{
 34}
 35#endif
 36
 37#ifdef CONFIG_SMP
 38static int alloc_masks(struct irq_desc *desc, gfp_t gfp, int node)
 39{
 40	if (!zalloc_cpumask_var_node(&desc->irq_data.affinity, gfp, node))
 
 41		return -ENOMEM;
 42
 
 
 
 
 
 
 
 
 43#ifdef CONFIG_GENERIC_PENDING_IRQ
 44	if (!zalloc_cpumask_var_node(&desc->pending_mask, gfp, node)) {
 45		free_cpumask_var(desc->irq_data.affinity);
 
 
 
 46		return -ENOMEM;
 47	}
 48#endif
 49	return 0;
 50}
 51
 52static void desc_smp_init(struct irq_desc *desc, int node)
 
 53{
 54	desc->irq_data.node = node;
 55	cpumask_copy(desc->irq_data.affinity, irq_default_affinity);
 
 
 56#ifdef CONFIG_GENERIC_PENDING_IRQ
 57	cpumask_clear(desc->pending_mask);
 58#endif
 59}
 60
 61static inline int desc_node(struct irq_desc *desc)
 62{
 63	return desc->irq_data.node;
 64}
 65
 66#else
 67static inline int
 68alloc_masks(struct irq_desc *desc, gfp_t gfp, int node) { return 0; }
 69static inline void desc_smp_init(struct irq_desc *desc, int node) { }
 70static inline int desc_node(struct irq_desc *desc) { return 0; }
 71#endif
 72
 73static void desc_set_defaults(unsigned int irq, struct irq_desc *desc, int node,
 74		struct module *owner)
 75{
 76	int cpu;
 77
 
 
 
 
 78	desc->irq_data.irq = irq;
 79	desc->irq_data.chip = &no_irq_chip;
 80	desc->irq_data.chip_data = NULL;
 81	desc->irq_data.handler_data = NULL;
 82	desc->irq_data.msi_desc = NULL;
 83	irq_settings_clr_and_set(desc, ~0, _IRQ_DEFAULT_INIT_FLAGS);
 84	irqd_set(&desc->irq_data, IRQD_IRQ_DISABLED);
 
 85	desc->handle_irq = handle_bad_irq;
 86	desc->depth = 1;
 87	desc->irq_count = 0;
 88	desc->irqs_unhandled = 0;
 89	desc->name = NULL;
 90	desc->owner = owner;
 91	for_each_possible_cpu(cpu)
 92		*per_cpu_ptr(desc->kstat_irqs, cpu) = 0;
 93	desc_smp_init(desc, node);
 94}
 95
 96int nr_irqs = NR_IRQS;
 97EXPORT_SYMBOL_GPL(nr_irqs);
 98
 99static DEFINE_MUTEX(sparse_irq_lock);
100static DECLARE_BITMAP(allocated_irqs, IRQ_BITMAP_BITS);
101
102#ifdef CONFIG_SPARSE_IRQ
103
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
104static RADIX_TREE(irq_desc_tree, GFP_KERNEL);
105
106static void irq_insert_desc(unsigned int irq, struct irq_desc *desc)
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}
115EXPORT_SYMBOL(irq_to_desc);
116
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
128	free_cpumask_var(desc->irq_data.affinity);
 
 
 
129}
130#else
131static inline void free_masks(struct irq_desc *desc) { }
132#endif
133
134static struct irq_desc *alloc_desc(int irq, int node, struct module *owner)
 
 
 
 
 
 
 
 
 
 
 
 
135{
136	struct irq_desc *desc;
137	gfp_t gfp = GFP_KERNEL;
138
139	desc = kzalloc_node(sizeof(*desc), gfp, node);
140	if (!desc)
141		return NULL;
142	/* allocate based on nr_cpu_ids */
143	desc->kstat_irqs = alloc_percpu(unsigned int);
144	if (!desc->kstat_irqs)
145		goto err_desc;
146
147	if (alloc_masks(desc, gfp, node))
148		goto err_kstat;
149
150	raw_spin_lock_init(&desc->lock);
151	lockdep_set_class(&desc->lock, &irq_desc_lock_class);
 
 
152
153	desc_set_defaults(irq, desc, node, owner);
 
 
154
155	return desc;
156
157err_kstat:
158	free_percpu(desc->kstat_irqs);
159err_desc:
160	kfree(desc);
161	return NULL;
162}
163
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
164static void free_desc(unsigned int irq)
165{
166	struct irq_desc *desc = irq_to_desc(irq);
167
 
168	unregister_irq_proc(irq, desc);
169
170	mutex_lock(&sparse_irq_lock);
 
 
 
 
 
 
 
 
 
171	delete_irq_desc(irq);
172	mutex_unlock(&sparse_irq_lock);
173
174	free_masks(desc);
175	free_percpu(desc->kstat_irqs);
176	kfree(desc);
 
 
 
177}
178
179static int alloc_descs(unsigned int start, unsigned int cnt, int node,
180		       struct module *owner)
181{
 
182	struct irq_desc *desc;
 
183	int i;
184
 
 
 
 
 
 
 
 
 
 
 
185	for (i = 0; i < cnt; i++) {
186		desc = alloc_desc(start + i, node, owner);
 
 
 
 
 
187		if (!desc)
188			goto err;
189		mutex_lock(&sparse_irq_lock);
190		irq_insert_desc(start + i, desc);
191		mutex_unlock(&sparse_irq_lock);
 
192	}
 
193	return start;
194
195err:
196	for (i--; i >= 0; i--)
197		free_desc(start + i);
198
199	mutex_lock(&sparse_irq_lock);
200	bitmap_clear(allocated_irqs, start, cnt);
201	mutex_unlock(&sparse_irq_lock);
202	return -ENOMEM;
203}
204
205static int irq_expand_nr_irqs(unsigned int nr)
206{
207	if (nr > IRQ_BITMAP_BITS)
208		return -ENOMEM;
209	nr_irqs = nr;
210	return 0;
211}
212
213int __init early_irq_init(void)
214{
215	int i, initcnt, node = first_online_node;
216	struct irq_desc *desc;
217
218	init_irq_default_affinity();
219
220	/* Let arch update nr_irqs and return the nr of preallocated irqs */
221	initcnt = arch_probe_nr_irqs();
222	printk(KERN_INFO "NR_IRQS:%d nr_irqs:%d %d\n", NR_IRQS, nr_irqs, initcnt);
 
223
224	if (WARN_ON(nr_irqs > IRQ_BITMAP_BITS))
225		nr_irqs = IRQ_BITMAP_BITS;
226
227	if (WARN_ON(initcnt > IRQ_BITMAP_BITS))
228		initcnt = IRQ_BITMAP_BITS;
229
230	if (initcnt > nr_irqs)
231		nr_irqs = initcnt;
232
233	for (i = 0; i < initcnt; i++) {
234		desc = alloc_desc(i, node, NULL);
235		set_bit(i, allocated_irqs);
236		irq_insert_desc(i, desc);
237	}
238	return arch_early_irq_init();
239}
240
241#else /* !CONFIG_SPARSE_IRQ */
242
243struct irq_desc irq_desc[NR_IRQS] __cacheline_aligned_in_smp = {
244	[0 ... NR_IRQS-1] = {
245		.handle_irq	= handle_bad_irq,
246		.depth		= 1,
247		.lock		= __RAW_SPIN_LOCK_UNLOCKED(irq_desc->lock),
248	}
249};
250
251int __init early_irq_init(void)
252{
253	int count, i, node = first_online_node;
254	struct irq_desc *desc;
255
256	init_irq_default_affinity();
257
258	printk(KERN_INFO "NR_IRQS:%d\n", NR_IRQS);
259
260	desc = irq_desc;
261	count = ARRAY_SIZE(irq_desc);
262
263	for (i = 0; i < count; i++) {
264		desc[i].kstat_irqs = alloc_percpu(unsigned int);
265		alloc_masks(&desc[i], GFP_KERNEL, node);
266		raw_spin_lock_init(&desc[i].lock);
267		lockdep_set_class(&desc[i].lock, &irq_desc_lock_class);
268		desc_set_defaults(i, &desc[i], node, NULL);
269	}
270	return arch_early_irq_init();
271}
272
273struct irq_desc *irq_to_desc(unsigned int irq)
274{
275	return (irq < NR_IRQS) ? irq_desc + irq : NULL;
276}
277EXPORT_SYMBOL(irq_to_desc);
278
279static void free_desc(unsigned int irq)
280{
281	dynamic_irq_cleanup(irq);
 
 
 
 
 
282}
283
284static inline int alloc_descs(unsigned int start, unsigned int cnt, int node,
 
285			      struct module *owner)
286{
287	u32 i;
288
289	for (i = 0; i < cnt; i++) {
290		struct irq_desc *desc = irq_to_desc(start + i);
291
292		desc->owner = owner;
293	}
 
294	return start;
295}
296
297static int irq_expand_nr_irqs(unsigned int nr)
298{
299	return -ENOMEM;
300}
301
 
 
 
 
 
 
 
 
 
 
 
 
 
 
302#endif /* !CONFIG_SPARSE_IRQ */
303
304/**
305 * generic_handle_irq - Invoke the handler for a particular irq
306 * @irq:	The irq number to handle
307 *
308 */
309int generic_handle_irq(unsigned int irq)
310{
311	struct irq_desc *desc = irq_to_desc(irq);
312
313	if (!desc)
314		return -EINVAL;
315	generic_handle_irq_desc(irq, desc);
316	return 0;
317}
318EXPORT_SYMBOL_GPL(generic_handle_irq);
319
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
320/* Dynamic interrupt handling */
321
322/**
323 * irq_free_descs - free irq descriptors
324 * @from:	Start of descriptor range
325 * @cnt:	Number of consecutive irqs to free
326 */
327void irq_free_descs(unsigned int from, unsigned int cnt)
328{
329	int i;
330
331	if (from >= nr_irqs || (from + cnt) > nr_irqs)
332		return;
333
 
334	for (i = 0; i < cnt; i++)
335		free_desc(from + i);
336
337	mutex_lock(&sparse_irq_lock);
338	bitmap_clear(allocated_irqs, from, cnt);
339	mutex_unlock(&sparse_irq_lock);
340}
341EXPORT_SYMBOL_GPL(irq_free_descs);
342
343/**
344 * irq_alloc_descs - allocate and initialize a range of irq descriptors
345 * @irq:	Allocate for specific irq number if irq >= 0
346 * @from:	Start the search from this irq number
347 * @cnt:	Number of consecutive irqs to allocate.
348 * @node:	Preferred node on which the irq descriptor should be allocated
349 * @owner:	Owning module (can be NULL)
 
 
 
350 *
351 * Returns the first irq number or error code
352 */
353int __ref
354__irq_alloc_descs(int irq, unsigned int from, unsigned int cnt, int node,
355		  struct module *owner)
356{
357	int start, ret;
358
359	if (!cnt)
360		return -EINVAL;
361
362	if (irq >= 0) {
363		if (from > irq)
364			return -EINVAL;
365		from = irq;
366	} else {
367		/*
368		 * For interrupts which are freely allocated the
369		 * architecture can force a lower bound to the @from
370		 * argument. x86 uses this to exclude the GSI space.
371		 */
372		from = arch_dynirq_lower_bound(from);
373	}
374
375	mutex_lock(&sparse_irq_lock);
376
377	start = bitmap_find_next_zero_area(allocated_irqs, IRQ_BITMAP_BITS,
378					   from, cnt, 0);
379	ret = -EEXIST;
380	if (irq >=0 && start != irq)
381		goto err;
382
383	if (start + cnt > nr_irqs) {
384		ret = irq_expand_nr_irqs(start + cnt);
385		if (ret)
386			goto err;
387	}
388
389	bitmap_set(allocated_irqs, start, cnt);
390	mutex_unlock(&sparse_irq_lock);
391	return alloc_descs(start, cnt, node, owner);
392
393err:
394	mutex_unlock(&sparse_irq_lock);
395	return ret;
396}
397EXPORT_SYMBOL_GPL(__irq_alloc_descs);
398
 
399/**
400 * irq_reserve_irqs - mark irqs allocated
401 * @from:	mark from irq number
402 * @cnt:	number of irqs to mark
403 *
404 * Returns 0 on success or an appropriate error code
405 */
406int irq_reserve_irqs(unsigned int from, unsigned int cnt)
407{
408	unsigned int start;
409	int ret = 0;
410
411	if (!cnt || (from + cnt) > nr_irqs)
412		return -EINVAL;
413
414	mutex_lock(&sparse_irq_lock);
415	start = bitmap_find_next_zero_area(allocated_irqs, nr_irqs, from, cnt, 0);
416	if (start == from)
417		bitmap_set(allocated_irqs, start, cnt);
418	else
419		ret = -EEXIST;
420	mutex_unlock(&sparse_irq_lock);
421	return ret;
 
 
 
 
 
 
422}
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
423
424/**
425 * irq_get_next_irq - get next allocated irq number
426 * @offset:	where to start the search
427 *
428 * Returns next irq number after offset or nr_irqs if none is found.
429 */
430unsigned int irq_get_next_irq(unsigned int offset)
431{
432	return find_next_bit(allocated_irqs, nr_irqs, offset);
433}
434
435struct irq_desc *
436__irq_get_desc_lock(unsigned int irq, unsigned long *flags, bool bus,
437		    unsigned int check)
438{
439	struct irq_desc *desc = irq_to_desc(irq);
440
441	if (desc) {
442		if (check & _IRQ_DESC_CHECK) {
443			if ((check & _IRQ_DESC_PERCPU) &&
444			    !irq_settings_is_per_cpu_devid(desc))
445				return NULL;
446
447			if (!(check & _IRQ_DESC_PERCPU) &&
448			    irq_settings_is_per_cpu_devid(desc))
449				return NULL;
450		}
451
452		if (bus)
453			chip_bus_lock(desc);
454		raw_spin_lock_irqsave(&desc->lock, *flags);
455	}
456	return desc;
457}
458
459void __irq_put_desc_unlock(struct irq_desc *desc, unsigned long flags, bool bus)
460{
461	raw_spin_unlock_irqrestore(&desc->lock, flags);
462	if (bus)
463		chip_bus_sync_unlock(desc);
464}
465
466int irq_set_percpu_devid(unsigned int irq)
 
467{
468	struct irq_desc *desc = irq_to_desc(irq);
469
470	if (!desc)
471		return -EINVAL;
472
473	if (desc->percpu_enabled)
474		return -EINVAL;
475
476	desc->percpu_enabled = kzalloc(sizeof(*desc->percpu_enabled), GFP_KERNEL);
477
478	if (!desc->percpu_enabled)
479		return -ENOMEM;
480
 
 
 
 
 
481	irq_set_percpu_devid_flags(irq);
482	return 0;
483}
484
485/**
486 * dynamic_irq_cleanup - cleanup a dynamically allocated irq
487 * @irq:	irq number to initialize
488 */
489void dynamic_irq_cleanup(unsigned int irq)
 
490{
491	struct irq_desc *desc = irq_to_desc(irq);
492	unsigned long flags;
493
494	raw_spin_lock_irqsave(&desc->lock, flags);
495	desc_set_defaults(irq, desc, desc_node(desc), NULL);
496	raw_spin_unlock_irqrestore(&desc->lock, flags);
 
 
 
 
497}
 
498
499void kstat_incr_irq_this_cpu(unsigned int irq)
500{
501	kstat_incr_irqs_this_cpu(irq, irq_to_desc(irq));
502}
503
 
 
 
 
 
 
 
 
 
504unsigned int kstat_irqs_cpu(unsigned int irq, int cpu)
505{
506	struct irq_desc *desc = irq_to_desc(irq);
507
508	return desc && desc->kstat_irqs ?
509			*per_cpu_ptr(desc->kstat_irqs, cpu) : 0;
510}
511
 
 
 
 
 
 
 
 
512unsigned int kstat_irqs(unsigned int irq)
513{
514	struct irq_desc *desc = irq_to_desc(irq);
515	int cpu;
516	int sum = 0;
517
518	if (!desc || !desc->kstat_irqs)
519		return 0;
520	for_each_possible_cpu(cpu)
521		sum += *per_cpu_ptr(desc->kstat_irqs, cpu);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
522	return sum;
523}
v4.17
  1// SPDX-License-Identifier: GPL-2.0
  2/*
  3 * Copyright (C) 1992, 1998-2006 Linus Torvalds, Ingo Molnar
  4 * Copyright (C) 2005-2006, Thomas Gleixner, Russell King
  5 *
  6 * This file contains the interrupt descriptor management code. Detailed
  7 * information is available in Documentation/core-api/genericirq.rst
 
  8 *
  9 */
 10#include <linux/irq.h>
 11#include <linux/slab.h>
 12#include <linux/export.h>
 13#include <linux/interrupt.h>
 14#include <linux/kernel_stat.h>
 15#include <linux/radix-tree.h>
 16#include <linux/bitmap.h>
 17#include <linux/irqdomain.h>
 18#include <linux/sysfs.h>
 19
 20#include "internals.h"
 21
 22/*
 23 * lockdep: we want to handle all irq_desc locks as a single lock-class:
 24 */
 25static struct lock_class_key irq_desc_lock_class;
 26
 27#if defined(CONFIG_SMP)
 28static int __init irq_affinity_setup(char *str)
 29{
 30	alloc_bootmem_cpumask_var(&irq_default_affinity);
 31	cpulist_parse(str, irq_default_affinity);
 32	/*
 33	 * Set at least the boot cpu. We don't want to end up with
 34	 * bugreports caused by random comandline masks
 35	 */
 36	cpumask_set_cpu(smp_processor_id(), irq_default_affinity);
 37	return 1;
 38}
 39__setup("irqaffinity=", irq_affinity_setup);
 40
 41static void __init init_irq_default_affinity(void)
 42{
 43	if (!cpumask_available(irq_default_affinity))
 44		zalloc_cpumask_var(&irq_default_affinity, GFP_NOWAIT);
 45	if (cpumask_empty(irq_default_affinity))
 46		cpumask_setall(irq_default_affinity);
 47}
 48#else
 49static void __init init_irq_default_affinity(void)
 50{
 51}
 52#endif
 53
 54#ifdef CONFIG_SMP
 55static int alloc_masks(struct irq_desc *desc, int node)
 56{
 57	if (!zalloc_cpumask_var_node(&desc->irq_common_data.affinity,
 58				     GFP_KERNEL, node))
 59		return -ENOMEM;
 60
 61#ifdef CONFIG_GENERIC_IRQ_EFFECTIVE_AFF_MASK
 62	if (!zalloc_cpumask_var_node(&desc->irq_common_data.effective_affinity,
 63				     GFP_KERNEL, node)) {
 64		free_cpumask_var(desc->irq_common_data.affinity);
 65		return -ENOMEM;
 66	}
 67#endif
 68
 69#ifdef CONFIG_GENERIC_PENDING_IRQ
 70	if (!zalloc_cpumask_var_node(&desc->pending_mask, GFP_KERNEL, node)) {
 71#ifdef CONFIG_GENERIC_IRQ_EFFECTIVE_AFF_MASK
 72		free_cpumask_var(desc->irq_common_data.effective_affinity);
 73#endif
 74		free_cpumask_var(desc->irq_common_data.affinity);
 75		return -ENOMEM;
 76	}
 77#endif
 78	return 0;
 79}
 80
 81static void desc_smp_init(struct irq_desc *desc, int node,
 82			  const struct cpumask *affinity)
 83{
 84	if (!affinity)
 85		affinity = irq_default_affinity;
 86	cpumask_copy(desc->irq_common_data.affinity, affinity);
 87
 88#ifdef CONFIG_GENERIC_PENDING_IRQ
 89	cpumask_clear(desc->pending_mask);
 90#endif
 91#ifdef CONFIG_NUMA
 92	desc->irq_common_data.node = node;
 93#endif
 
 
 94}
 95
 96#else
 97static inline int
 98alloc_masks(struct irq_desc *desc, int node) { return 0; }
 99static inline void
100desc_smp_init(struct irq_desc *desc, int node, const struct cpumask *affinity) { }
101#endif
102
103static void desc_set_defaults(unsigned int irq, struct irq_desc *desc, int node,
104			      const struct cpumask *affinity, struct module *owner)
105{
106	int cpu;
107
108	desc->irq_common_data.handler_data = NULL;
109	desc->irq_common_data.msi_desc = NULL;
110
111	desc->irq_data.common = &desc->irq_common_data;
112	desc->irq_data.irq = irq;
113	desc->irq_data.chip = &no_irq_chip;
114	desc->irq_data.chip_data = NULL;
 
 
115	irq_settings_clr_and_set(desc, ~0, _IRQ_DEFAULT_INIT_FLAGS);
116	irqd_set(&desc->irq_data, IRQD_IRQ_DISABLED);
117	irqd_set(&desc->irq_data, IRQD_IRQ_MASKED);
118	desc->handle_irq = handle_bad_irq;
119	desc->depth = 1;
120	desc->irq_count = 0;
121	desc->irqs_unhandled = 0;
122	desc->name = NULL;
123	desc->owner = owner;
124	for_each_possible_cpu(cpu)
125		*per_cpu_ptr(desc->kstat_irqs, cpu) = 0;
126	desc_smp_init(desc, node, affinity);
127}
128
129int nr_irqs = NR_IRQS;
130EXPORT_SYMBOL_GPL(nr_irqs);
131
132static DEFINE_MUTEX(sparse_irq_lock);
133static DECLARE_BITMAP(allocated_irqs, IRQ_BITMAP_BITS);
134
135#ifdef CONFIG_SPARSE_IRQ
136
137static void irq_kobj_release(struct kobject *kobj);
138
139#ifdef CONFIG_SYSFS
140static struct kobject *irq_kobj_base;
141
142#define IRQ_ATTR_RO(_name) \
143static struct kobj_attribute _name##_attr = __ATTR_RO(_name)
144
145static ssize_t per_cpu_count_show(struct kobject *kobj,
146				  struct kobj_attribute *attr, char *buf)
147{
148	struct irq_desc *desc = container_of(kobj, struct irq_desc, kobj);
149	int cpu, irq = desc->irq_data.irq;
150	ssize_t ret = 0;
151	char *p = "";
152
153	for_each_possible_cpu(cpu) {
154		unsigned int c = kstat_irqs_cpu(irq, cpu);
155
156		ret += scnprintf(buf + ret, PAGE_SIZE - ret, "%s%u", p, c);
157		p = ",";
158	}
159
160	ret += scnprintf(buf + ret, PAGE_SIZE - ret, "\n");
161	return ret;
162}
163IRQ_ATTR_RO(per_cpu_count);
164
165static ssize_t chip_name_show(struct kobject *kobj,
166			      struct kobj_attribute *attr, char *buf)
167{
168	struct irq_desc *desc = container_of(kobj, struct irq_desc, kobj);
169	ssize_t ret = 0;
170
171	raw_spin_lock_irq(&desc->lock);
172	if (desc->irq_data.chip && desc->irq_data.chip->name) {
173		ret = scnprintf(buf, PAGE_SIZE, "%s\n",
174				desc->irq_data.chip->name);
175	}
176	raw_spin_unlock_irq(&desc->lock);
177
178	return ret;
179}
180IRQ_ATTR_RO(chip_name);
181
182static ssize_t hwirq_show(struct kobject *kobj,
183			  struct kobj_attribute *attr, char *buf)
184{
185	struct irq_desc *desc = container_of(kobj, struct irq_desc, kobj);
186	ssize_t ret = 0;
187
188	raw_spin_lock_irq(&desc->lock);
189	if (desc->irq_data.domain)
190		ret = sprintf(buf, "%d\n", (int)desc->irq_data.hwirq);
191	raw_spin_unlock_irq(&desc->lock);
192
193	return ret;
194}
195IRQ_ATTR_RO(hwirq);
196
197static ssize_t type_show(struct kobject *kobj,
198			 struct kobj_attribute *attr, char *buf)
199{
200	struct irq_desc *desc = container_of(kobj, struct irq_desc, kobj);
201	ssize_t ret = 0;
202
203	raw_spin_lock_irq(&desc->lock);
204	ret = sprintf(buf, "%s\n",
205		      irqd_is_level_type(&desc->irq_data) ? "level" : "edge");
206	raw_spin_unlock_irq(&desc->lock);
207
208	return ret;
209
210}
211IRQ_ATTR_RO(type);
212
213static ssize_t wakeup_show(struct kobject *kobj,
214			   struct kobj_attribute *attr, char *buf)
215{
216	struct irq_desc *desc = container_of(kobj, struct irq_desc, kobj);
217	ssize_t ret = 0;
218
219	raw_spin_lock_irq(&desc->lock);
220	ret = sprintf(buf, "%s\n",
221		      irqd_is_wakeup_set(&desc->irq_data) ? "enabled" : "disabled");
222	raw_spin_unlock_irq(&desc->lock);
223
224	return ret;
225
226}
227IRQ_ATTR_RO(wakeup);
228
229static ssize_t name_show(struct kobject *kobj,
230			 struct kobj_attribute *attr, char *buf)
231{
232	struct irq_desc *desc = container_of(kobj, struct irq_desc, kobj);
233	ssize_t ret = 0;
234
235	raw_spin_lock_irq(&desc->lock);
236	if (desc->name)
237		ret = scnprintf(buf, PAGE_SIZE, "%s\n", desc->name);
238	raw_spin_unlock_irq(&desc->lock);
239
240	return ret;
241}
242IRQ_ATTR_RO(name);
243
244static ssize_t actions_show(struct kobject *kobj,
245			    struct kobj_attribute *attr, char *buf)
246{
247	struct irq_desc *desc = container_of(kobj, struct irq_desc, kobj);
248	struct irqaction *action;
249	ssize_t ret = 0;
250	char *p = "";
251
252	raw_spin_lock_irq(&desc->lock);
253	for (action = desc->action; action != NULL; action = action->next) {
254		ret += scnprintf(buf + ret, PAGE_SIZE - ret, "%s%s",
255				 p, action->name);
256		p = ",";
257	}
258	raw_spin_unlock_irq(&desc->lock);
259
260	if (ret)
261		ret += scnprintf(buf + ret, PAGE_SIZE - ret, "\n");
262
263	return ret;
264}
265IRQ_ATTR_RO(actions);
266
267static struct attribute *irq_attrs[] = {
268	&per_cpu_count_attr.attr,
269	&chip_name_attr.attr,
270	&hwirq_attr.attr,
271	&type_attr.attr,
272	&wakeup_attr.attr,
273	&name_attr.attr,
274	&actions_attr.attr,
275	NULL
276};
277
278static struct kobj_type irq_kobj_type = {
279	.release	= irq_kobj_release,
280	.sysfs_ops	= &kobj_sysfs_ops,
281	.default_attrs	= irq_attrs,
282};
283
284static void irq_sysfs_add(int irq, struct irq_desc *desc)
285{
286	if (irq_kobj_base) {
287		/*
288		 * Continue even in case of failure as this is nothing
289		 * crucial.
290		 */
291		if (kobject_add(&desc->kobj, irq_kobj_base, "%d", irq))
292			pr_warn("Failed to add kobject for irq %d\n", irq);
293	}
294}
295
296static int __init irq_sysfs_init(void)
297{
298	struct irq_desc *desc;
299	int irq;
300
301	/* Prevent concurrent irq alloc/free */
302	irq_lock_sparse();
303
304	irq_kobj_base = kobject_create_and_add("irq", kernel_kobj);
305	if (!irq_kobj_base) {
306		irq_unlock_sparse();
307		return -ENOMEM;
308	}
309
310	/* Add the already allocated interrupts */
311	for_each_irq_desc(irq, desc)
312		irq_sysfs_add(irq, desc);
313	irq_unlock_sparse();
314
315	return 0;
316}
317postcore_initcall(irq_sysfs_init);
318
319#else /* !CONFIG_SYSFS */
320
321static struct kobj_type irq_kobj_type = {
322	.release	= irq_kobj_release,
323};
324
325static void irq_sysfs_add(int irq, struct irq_desc *desc) {}
326
327#endif /* CONFIG_SYSFS */
328
329static RADIX_TREE(irq_desc_tree, GFP_KERNEL);
330
331static void irq_insert_desc(unsigned int irq, struct irq_desc *desc)
332{
333	radix_tree_insert(&irq_desc_tree, irq, desc);
334}
335
336struct irq_desc *irq_to_desc(unsigned int irq)
337{
338	return radix_tree_lookup(&irq_desc_tree, irq);
339}
340EXPORT_SYMBOL(irq_to_desc);
341
342static void delete_irq_desc(unsigned int irq)
343{
344	radix_tree_delete(&irq_desc_tree, irq);
345}
346
347#ifdef CONFIG_SMP
348static void free_masks(struct irq_desc *desc)
349{
350#ifdef CONFIG_GENERIC_PENDING_IRQ
351	free_cpumask_var(desc->pending_mask);
352#endif
353	free_cpumask_var(desc->irq_common_data.affinity);
354#ifdef CONFIG_GENERIC_IRQ_EFFECTIVE_AFF_MASK
355	free_cpumask_var(desc->irq_common_data.effective_affinity);
356#endif
357}
358#else
359static inline void free_masks(struct irq_desc *desc) { }
360#endif
361
362void irq_lock_sparse(void)
363{
364	mutex_lock(&sparse_irq_lock);
365}
366
367void irq_unlock_sparse(void)
368{
369	mutex_unlock(&sparse_irq_lock);
370}
371
372static struct irq_desc *alloc_desc(int irq, int node, unsigned int flags,
373				   const struct cpumask *affinity,
374				   struct module *owner)
375{
376	struct irq_desc *desc;
 
377
378	desc = kzalloc_node(sizeof(*desc), GFP_KERNEL, node);
379	if (!desc)
380		return NULL;
381	/* allocate based on nr_cpu_ids */
382	desc->kstat_irqs = alloc_percpu(unsigned int);
383	if (!desc->kstat_irqs)
384		goto err_desc;
385
386	if (alloc_masks(desc, node))
387		goto err_kstat;
388
389	raw_spin_lock_init(&desc->lock);
390	lockdep_set_class(&desc->lock, &irq_desc_lock_class);
391	mutex_init(&desc->request_mutex);
392	init_rcu_head(&desc->rcu);
393
394	desc_set_defaults(irq, desc, node, affinity, owner);
395	irqd_set(&desc->irq_data, flags);
396	kobject_init(&desc->kobj, &irq_kobj_type);
397
398	return desc;
399
400err_kstat:
401	free_percpu(desc->kstat_irqs);
402err_desc:
403	kfree(desc);
404	return NULL;
405}
406
407static void irq_kobj_release(struct kobject *kobj)
408{
409	struct irq_desc *desc = container_of(kobj, struct irq_desc, kobj);
410
411	free_masks(desc);
412	free_percpu(desc->kstat_irqs);
413	kfree(desc);
414}
415
416static void delayed_free_desc(struct rcu_head *rhp)
417{
418	struct irq_desc *desc = container_of(rhp, struct irq_desc, rcu);
419
420	kobject_put(&desc->kobj);
421}
422
423static void free_desc(unsigned int irq)
424{
425	struct irq_desc *desc = irq_to_desc(irq);
426
427	irq_remove_debugfs_entry(desc);
428	unregister_irq_proc(irq, desc);
429
430	/*
431	 * sparse_irq_lock protects also show_interrupts() and
432	 * kstat_irq_usr(). Once we deleted the descriptor from the
433	 * sparse tree we can free it. Access in proc will fail to
434	 * lookup the descriptor.
435	 *
436	 * The sysfs entry must be serialized against a concurrent
437	 * irq_sysfs_init() as well.
438	 */
439	kobject_del(&desc->kobj);
440	delete_irq_desc(irq);
 
441
442	/*
443	 * We free the descriptor, masks and stat fields via RCU. That
444	 * allows demultiplex interrupts to do rcu based management of
445	 * the child interrupts.
446	 */
447	call_rcu(&desc->rcu, delayed_free_desc);
448}
449
450static int alloc_descs(unsigned int start, unsigned int cnt, int node,
451		       const struct cpumask *affinity, struct module *owner)
452{
453	const struct cpumask *mask = NULL;
454	struct irq_desc *desc;
455	unsigned int flags;
456	int i;
457
458	/* Validate affinity mask(s) */
459	if (affinity) {
460		for (i = 0, mask = affinity; i < cnt; i++, mask++) {
461			if (cpumask_empty(mask))
462				return -EINVAL;
463		}
464	}
465
466	flags = affinity ? IRQD_AFFINITY_MANAGED | IRQD_MANAGED_SHUTDOWN : 0;
467	mask = NULL;
468
469	for (i = 0; i < cnt; i++) {
470		if (affinity) {
471			node = cpu_to_node(cpumask_first(affinity));
472			mask = affinity;
473			affinity++;
474		}
475		desc = alloc_desc(start + i, node, flags, mask, owner);
476		if (!desc)
477			goto err;
 
478		irq_insert_desc(start + i, desc);
479		irq_sysfs_add(start + i, desc);
480		irq_add_debugfs_entry(start + i, desc);
481	}
482	bitmap_set(allocated_irqs, start, cnt);
483	return start;
484
485err:
486	for (i--; i >= 0; i--)
487		free_desc(start + i);
 
 
 
 
488	return -ENOMEM;
489}
490
491static int irq_expand_nr_irqs(unsigned int nr)
492{
493	if (nr > IRQ_BITMAP_BITS)
494		return -ENOMEM;
495	nr_irqs = nr;
496	return 0;
497}
498
499int __init early_irq_init(void)
500{
501	int i, initcnt, node = first_online_node;
502	struct irq_desc *desc;
503
504	init_irq_default_affinity();
505
506	/* Let arch update nr_irqs and return the nr of preallocated irqs */
507	initcnt = arch_probe_nr_irqs();
508	printk(KERN_INFO "NR_IRQS: %d, nr_irqs: %d, preallocated irqs: %d\n",
509	       NR_IRQS, nr_irqs, initcnt);
510
511	if (WARN_ON(nr_irqs > IRQ_BITMAP_BITS))
512		nr_irqs = IRQ_BITMAP_BITS;
513
514	if (WARN_ON(initcnt > IRQ_BITMAP_BITS))
515		initcnt = IRQ_BITMAP_BITS;
516
517	if (initcnt > nr_irqs)
518		nr_irqs = initcnt;
519
520	for (i = 0; i < initcnt; i++) {
521		desc = alloc_desc(i, node, 0, NULL, NULL);
522		set_bit(i, allocated_irqs);
523		irq_insert_desc(i, desc);
524	}
525	return arch_early_irq_init();
526}
527
528#else /* !CONFIG_SPARSE_IRQ */
529
530struct irq_desc irq_desc[NR_IRQS] __cacheline_aligned_in_smp = {
531	[0 ... NR_IRQS-1] = {
532		.handle_irq	= handle_bad_irq,
533		.depth		= 1,
534		.lock		= __RAW_SPIN_LOCK_UNLOCKED(irq_desc->lock),
535	}
536};
537
538int __init early_irq_init(void)
539{
540	int count, i, node = first_online_node;
541	struct irq_desc *desc;
542
543	init_irq_default_affinity();
544
545	printk(KERN_INFO "NR_IRQS: %d\n", NR_IRQS);
546
547	desc = irq_desc;
548	count = ARRAY_SIZE(irq_desc);
549
550	for (i = 0; i < count; i++) {
551		desc[i].kstat_irqs = alloc_percpu(unsigned int);
552		alloc_masks(&desc[i], node);
553		raw_spin_lock_init(&desc[i].lock);
554		lockdep_set_class(&desc[i].lock, &irq_desc_lock_class);
555		desc_set_defaults(i, &desc[i], node, NULL, NULL);
556	}
557	return arch_early_irq_init();
558}
559
560struct irq_desc *irq_to_desc(unsigned int irq)
561{
562	return (irq < NR_IRQS) ? irq_desc + irq : NULL;
563}
564EXPORT_SYMBOL(irq_to_desc);
565
566static void free_desc(unsigned int irq)
567{
568	struct irq_desc *desc = irq_to_desc(irq);
569	unsigned long flags;
570
571	raw_spin_lock_irqsave(&desc->lock, flags);
572	desc_set_defaults(irq, desc, irq_desc_get_node(desc), NULL, NULL);
573	raw_spin_unlock_irqrestore(&desc->lock, flags);
574}
575
576static inline int alloc_descs(unsigned int start, unsigned int cnt, int node,
577			      const struct cpumask *affinity,
578			      struct module *owner)
579{
580	u32 i;
581
582	for (i = 0; i < cnt; i++) {
583		struct irq_desc *desc = irq_to_desc(start + i);
584
585		desc->owner = owner;
586	}
587	bitmap_set(allocated_irqs, start, cnt);
588	return start;
589}
590
591static int irq_expand_nr_irqs(unsigned int nr)
592{
593	return -ENOMEM;
594}
595
596void irq_mark_irq(unsigned int irq)
597{
598	mutex_lock(&sparse_irq_lock);
599	bitmap_set(allocated_irqs, irq, 1);
600	mutex_unlock(&sparse_irq_lock);
601}
602
603#ifdef CONFIG_GENERIC_IRQ_LEGACY
604void irq_init_desc(unsigned int irq)
605{
606	free_desc(irq);
607}
608#endif
609
610#endif /* !CONFIG_SPARSE_IRQ */
611
612/**
613 * generic_handle_irq - Invoke the handler for a particular irq
614 * @irq:	The irq number to handle
615 *
616 */
617int generic_handle_irq(unsigned int irq)
618{
619	struct irq_desc *desc = irq_to_desc(irq);
620
621	if (!desc)
622		return -EINVAL;
623	generic_handle_irq_desc(desc);
624	return 0;
625}
626EXPORT_SYMBOL_GPL(generic_handle_irq);
627
628#ifdef CONFIG_HANDLE_DOMAIN_IRQ
629/**
630 * __handle_domain_irq - Invoke the handler for a HW irq belonging to a domain
631 * @domain:	The domain where to perform the lookup
632 * @hwirq:	The HW irq number to convert to a logical one
633 * @lookup:	Whether to perform the domain lookup or not
634 * @regs:	Register file coming from the low-level handling code
635 *
636 * Returns:	0 on success, or -EINVAL if conversion has failed
637 */
638int __handle_domain_irq(struct irq_domain *domain, unsigned int hwirq,
639			bool lookup, struct pt_regs *regs)
640{
641	struct pt_regs *old_regs = set_irq_regs(regs);
642	unsigned int irq = hwirq;
643	int ret = 0;
644
645	irq_enter();
646
647#ifdef CONFIG_IRQ_DOMAIN
648	if (lookup)
649		irq = irq_find_mapping(domain, hwirq);
650#endif
651
652	/*
653	 * Some hardware gives randomly wrong interrupts.  Rather
654	 * than crashing, do something sensible.
655	 */
656	if (unlikely(!irq || irq >= nr_irqs)) {
657		ack_bad_irq(irq);
658		ret = -EINVAL;
659	} else {
660		generic_handle_irq(irq);
661	}
662
663	irq_exit();
664	set_irq_regs(old_regs);
665	return ret;
666}
667#endif
668
669/* Dynamic interrupt handling */
670
671/**
672 * irq_free_descs - free irq descriptors
673 * @from:	Start of descriptor range
674 * @cnt:	Number of consecutive irqs to free
675 */
676void irq_free_descs(unsigned int from, unsigned int cnt)
677{
678	int i;
679
680	if (from >= nr_irqs || (from + cnt) > nr_irqs)
681		return;
682
683	mutex_lock(&sparse_irq_lock);
684	for (i = 0; i < cnt; i++)
685		free_desc(from + i);
686
 
687	bitmap_clear(allocated_irqs, from, cnt);
688	mutex_unlock(&sparse_irq_lock);
689}
690EXPORT_SYMBOL_GPL(irq_free_descs);
691
692/**
693 * irq_alloc_descs - allocate and initialize a range of irq descriptors
694 * @irq:	Allocate for specific irq number if irq >= 0
695 * @from:	Start the search from this irq number
696 * @cnt:	Number of consecutive irqs to allocate.
697 * @node:	Preferred node on which the irq descriptor should be allocated
698 * @owner:	Owning module (can be NULL)
699 * @affinity:	Optional pointer to an affinity mask array of size @cnt which
700 *		hints where the irq descriptors should be allocated and which
701 *		default affinities to use
702 *
703 * Returns the first irq number or error code
704 */
705int __ref
706__irq_alloc_descs(int irq, unsigned int from, unsigned int cnt, int node,
707		  struct module *owner, const struct cpumask *affinity)
708{
709	int start, ret;
710
711	if (!cnt)
712		return -EINVAL;
713
714	if (irq >= 0) {
715		if (from > irq)
716			return -EINVAL;
717		from = irq;
718	} else {
719		/*
720		 * For interrupts which are freely allocated the
721		 * architecture can force a lower bound to the @from
722		 * argument. x86 uses this to exclude the GSI space.
723		 */
724		from = arch_dynirq_lower_bound(from);
725	}
726
727	mutex_lock(&sparse_irq_lock);
728
729	start = bitmap_find_next_zero_area(allocated_irqs, IRQ_BITMAP_BITS,
730					   from, cnt, 0);
731	ret = -EEXIST;
732	if (irq >=0 && start != irq)
733		goto unlock;
734
735	if (start + cnt > nr_irqs) {
736		ret = irq_expand_nr_irqs(start + cnt);
737		if (ret)
738			goto unlock;
739	}
740	ret = alloc_descs(start, cnt, node, affinity, owner);
741unlock:
 
 
 
 
742	mutex_unlock(&sparse_irq_lock);
743	return ret;
744}
745EXPORT_SYMBOL_GPL(__irq_alloc_descs);
746
747#ifdef CONFIG_GENERIC_IRQ_LEGACY_ALLOC_HWIRQ
748/**
749 * irq_alloc_hwirqs - Allocate an irq descriptor and initialize the hardware
750 * @cnt:	number of interrupts to allocate
751 * @node:	node on which to allocate
752 *
753 * Returns an interrupt number > 0 or 0, if the allocation fails.
754 */
755unsigned int irq_alloc_hwirqs(int cnt, int node)
756{
757	int i, irq = __irq_alloc_descs(-1, 0, cnt, node, NULL, NULL);
 
758
759	if (irq < 0)
760		return 0;
761
762	for (i = irq; cnt > 0; i++, cnt--) {
763		if (arch_setup_hwirq(i, node))
764			goto err;
765		irq_clear_status_flags(i, _IRQ_NOREQUEST);
766	}
767	return irq;
768
769err:
770	for (i--; i >= irq; i--) {
771		irq_set_status_flags(i, _IRQ_NOREQUEST | _IRQ_NOPROBE);
772		arch_teardown_hwirq(i);
773	}
774	irq_free_descs(irq, cnt);
775	return 0;
776}
777EXPORT_SYMBOL_GPL(irq_alloc_hwirqs);
778
779/**
780 * irq_free_hwirqs - Free irq descriptor and cleanup the hardware
781 * @from:	Free from irq number
782 * @cnt:	number of interrupts to free
783 *
784 */
785void irq_free_hwirqs(unsigned int from, int cnt)
786{
787	int i, j;
788
789	for (i = from, j = cnt; j > 0; i++, j--) {
790		irq_set_status_flags(i, _IRQ_NOREQUEST | _IRQ_NOPROBE);
791		arch_teardown_hwirq(i);
792	}
793	irq_free_descs(from, cnt);
794}
795EXPORT_SYMBOL_GPL(irq_free_hwirqs);
796#endif
797
798/**
799 * irq_get_next_irq - get next allocated irq number
800 * @offset:	where to start the search
801 *
802 * Returns next irq number after offset or nr_irqs if none is found.
803 */
804unsigned int irq_get_next_irq(unsigned int offset)
805{
806	return find_next_bit(allocated_irqs, nr_irqs, offset);
807}
808
809struct irq_desc *
810__irq_get_desc_lock(unsigned int irq, unsigned long *flags, bool bus,
811		    unsigned int check)
812{
813	struct irq_desc *desc = irq_to_desc(irq);
814
815	if (desc) {
816		if (check & _IRQ_DESC_CHECK) {
817			if ((check & _IRQ_DESC_PERCPU) &&
818			    !irq_settings_is_per_cpu_devid(desc))
819				return NULL;
820
821			if (!(check & _IRQ_DESC_PERCPU) &&
822			    irq_settings_is_per_cpu_devid(desc))
823				return NULL;
824		}
825
826		if (bus)
827			chip_bus_lock(desc);
828		raw_spin_lock_irqsave(&desc->lock, *flags);
829	}
830	return desc;
831}
832
833void __irq_put_desc_unlock(struct irq_desc *desc, unsigned long flags, bool bus)
834{
835	raw_spin_unlock_irqrestore(&desc->lock, flags);
836	if (bus)
837		chip_bus_sync_unlock(desc);
838}
839
840int irq_set_percpu_devid_partition(unsigned int irq,
841				   const struct cpumask *affinity)
842{
843	struct irq_desc *desc = irq_to_desc(irq);
844
845	if (!desc)
846		return -EINVAL;
847
848	if (desc->percpu_enabled)
849		return -EINVAL;
850
851	desc->percpu_enabled = kzalloc(sizeof(*desc->percpu_enabled), GFP_KERNEL);
852
853	if (!desc->percpu_enabled)
854		return -ENOMEM;
855
856	if (affinity)
857		desc->percpu_affinity = affinity;
858	else
859		desc->percpu_affinity = cpu_possible_mask;
860
861	irq_set_percpu_devid_flags(irq);
862	return 0;
863}
864
865int irq_set_percpu_devid(unsigned int irq)
866{
867	return irq_set_percpu_devid_partition(irq, NULL);
868}
869
870int irq_get_percpu_devid_partition(unsigned int irq, struct cpumask *affinity)
871{
872	struct irq_desc *desc = irq_to_desc(irq);
 
873
874	if (!desc || !desc->percpu_enabled)
875		return -EINVAL;
876
877	if (affinity)
878		cpumask_copy(affinity, desc->percpu_affinity);
879
880	return 0;
881}
882EXPORT_SYMBOL_GPL(irq_get_percpu_devid_partition);
883
884void kstat_incr_irq_this_cpu(unsigned int irq)
885{
886	kstat_incr_irqs_this_cpu(irq_to_desc(irq));
887}
888
889/**
890 * kstat_irqs_cpu - Get the statistics for an interrupt on a cpu
891 * @irq:	The interrupt number
892 * @cpu:	The cpu number
893 *
894 * Returns the sum of interrupt counts on @cpu since boot for
895 * @irq. The caller must ensure that the interrupt is not removed
896 * concurrently.
897 */
898unsigned int kstat_irqs_cpu(unsigned int irq, int cpu)
899{
900	struct irq_desc *desc = irq_to_desc(irq);
901
902	return desc && desc->kstat_irqs ?
903			*per_cpu_ptr(desc->kstat_irqs, cpu) : 0;
904}
905
906/**
907 * kstat_irqs - Get the statistics for an interrupt
908 * @irq:	The interrupt number
909 *
910 * Returns the sum of interrupt counts on all cpus since boot for
911 * @irq. The caller must ensure that the interrupt is not removed
912 * concurrently.
913 */
914unsigned int kstat_irqs(unsigned int irq)
915{
916	struct irq_desc *desc = irq_to_desc(irq);
917	int cpu;
918	unsigned int sum = 0;
919
920	if (!desc || !desc->kstat_irqs)
921		return 0;
922	for_each_possible_cpu(cpu)
923		sum += *per_cpu_ptr(desc->kstat_irqs, cpu);
924	return sum;
925}
926
927/**
928 * kstat_irqs_usr - Get the statistics for an interrupt
929 * @irq:	The interrupt number
930 *
931 * Returns the sum of interrupt counts on all cpus since boot for
932 * @irq. Contrary to kstat_irqs() this can be called from any
933 * preemptible context. It's protected against concurrent removal of
934 * an interrupt descriptor when sparse irqs are enabled.
935 */
936unsigned int kstat_irqs_usr(unsigned int irq)
937{
938	unsigned int sum;
939
940	irq_lock_sparse();
941	sum = kstat_irqs(irq);
942	irq_unlock_sparse();
943	return sum;
944}