1 // SPDX-License-Identifier: GPL-2.0
3 * Copyright (C) 1992, 1998-2006 Linus Torvalds, Ingo Molnar
4 * Copyright (C) 2005-2006, Thomas Gleixner, Russell King
6 * This file contains the interrupt descriptor management code. Detailed
7 * information is available in Documentation/core-api/genericirq.rst
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>
20 #include "internals.h"
23 * lockdep: we want to handle all irq_desc locks as a single lock-class:
25 static struct lock_class_key irq_desc_lock_class;
27 #if defined(CONFIG_SMP)
28 static int __init irq_affinity_setup(char *str)
30 alloc_bootmem_cpumask_var(&irq_default_affinity);
31 cpulist_parse(str, irq_default_affinity);
33 * Set at least the boot cpu. We don't want to end up with
34 * bugreports caused by random commandline masks
36 cpumask_set_cpu(smp_processor_id(), irq_default_affinity);
39 __setup("irqaffinity=", irq_affinity_setup);
41 static void __init init_irq_default_affinity(void)
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);
49 static void __init init_irq_default_affinity(void)
55 static int alloc_masks(struct irq_desc *desc, int node)
57 if (!zalloc_cpumask_var_node(&desc->irq_common_data.affinity,
61 #ifdef CONFIG_GENERIC_IRQ_EFFECTIVE_AFF_MASK
62 if (!zalloc_cpumask_var_node(&desc->irq_common_data.effective_affinity,
64 free_cpumask_var(desc->irq_common_data.affinity);
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);
74 free_cpumask_var(desc->irq_common_data.affinity);
81 static void desc_smp_init(struct irq_desc *desc, int node,
82 const struct cpumask *affinity)
85 affinity = irq_default_affinity;
86 cpumask_copy(desc->irq_common_data.affinity, affinity);
88 #ifdef CONFIG_GENERIC_PENDING_IRQ
89 cpumask_clear(desc->pending_mask);
92 desc->irq_common_data.node = node;
98 alloc_masks(struct irq_desc *desc, int node) { return 0; }
100 desc_smp_init(struct irq_desc *desc, int node, const struct cpumask *affinity) { }
103 static void desc_set_defaults(unsigned int irq, struct irq_desc *desc, int node,
104 const struct cpumask *affinity, struct module *owner)
108 desc->irq_common_data.handler_data = NULL;
109 desc->irq_common_data.msi_desc = NULL;
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;
121 desc->irqs_unhandled = 0;
125 for_each_possible_cpu(cpu)
126 *per_cpu_ptr(desc->kstat_irqs, cpu) = 0;
127 desc_smp_init(desc, node, affinity);
130 int nr_irqs = NR_IRQS;
131 EXPORT_SYMBOL_GPL(nr_irqs);
133 static DEFINE_MUTEX(sparse_irq_lock);
134 static DECLARE_BITMAP(allocated_irqs, IRQ_BITMAP_BITS);
136 #ifdef CONFIG_SPARSE_IRQ
138 static void irq_kobj_release(struct kobject *kobj);
141 static struct kobject *irq_kobj_base;
143 #define IRQ_ATTR_RO(_name) \
144 static struct kobj_attribute _name##_attr = __ATTR_RO(_name)
146 static ssize_t per_cpu_count_show(struct kobject *kobj,
147 struct kobj_attribute *attr, char *buf)
149 struct irq_desc *desc = container_of(kobj, struct irq_desc, kobj);
154 for_each_possible_cpu(cpu) {
155 unsigned int c = irq_desc_kstat_cpu(desc, cpu);
157 ret += scnprintf(buf + ret, PAGE_SIZE - ret, "%s%u", p, c);
161 ret += scnprintf(buf + ret, PAGE_SIZE - ret, "\n");
164 IRQ_ATTR_RO(per_cpu_count);
166 static ssize_t chip_name_show(struct kobject *kobj,
167 struct kobj_attribute *attr, char *buf)
169 struct irq_desc *desc = container_of(kobj, struct irq_desc, kobj);
172 raw_spin_lock_irq(&desc->lock);
173 if (desc->irq_data.chip && desc->irq_data.chip->name) {
174 ret = scnprintf(buf, PAGE_SIZE, "%s\n",
175 desc->irq_data.chip->name);
177 raw_spin_unlock_irq(&desc->lock);
181 IRQ_ATTR_RO(chip_name);
183 static ssize_t hwirq_show(struct kobject *kobj,
184 struct kobj_attribute *attr, char *buf)
186 struct irq_desc *desc = container_of(kobj, struct irq_desc, kobj);
189 raw_spin_lock_irq(&desc->lock);
190 if (desc->irq_data.domain)
191 ret = sprintf(buf, "%lu\n", desc->irq_data.hwirq);
192 raw_spin_unlock_irq(&desc->lock);
198 static ssize_t type_show(struct kobject *kobj,
199 struct kobj_attribute *attr, char *buf)
201 struct irq_desc *desc = container_of(kobj, struct irq_desc, kobj);
204 raw_spin_lock_irq(&desc->lock);
205 ret = sprintf(buf, "%s\n",
206 irqd_is_level_type(&desc->irq_data) ? "level" : "edge");
207 raw_spin_unlock_irq(&desc->lock);
214 static ssize_t wakeup_show(struct kobject *kobj,
215 struct kobj_attribute *attr, char *buf)
217 struct irq_desc *desc = container_of(kobj, struct irq_desc, kobj);
220 raw_spin_lock_irq(&desc->lock);
221 ret = sprintf(buf, "%s\n",
222 irqd_is_wakeup_set(&desc->irq_data) ? "enabled" : "disabled");
223 raw_spin_unlock_irq(&desc->lock);
230 static ssize_t name_show(struct kobject *kobj,
231 struct kobj_attribute *attr, char *buf)
233 struct irq_desc *desc = container_of(kobj, struct irq_desc, kobj);
236 raw_spin_lock_irq(&desc->lock);
238 ret = scnprintf(buf, PAGE_SIZE, "%s\n", desc->name);
239 raw_spin_unlock_irq(&desc->lock);
245 static ssize_t actions_show(struct kobject *kobj,
246 struct kobj_attribute *attr, char *buf)
248 struct irq_desc *desc = container_of(kobj, struct irq_desc, kobj);
249 struct irqaction *action;
253 raw_spin_lock_irq(&desc->lock);
254 for (action = desc->action; action != NULL; action = action->next) {
255 ret += scnprintf(buf + ret, PAGE_SIZE - ret, "%s%s",
259 raw_spin_unlock_irq(&desc->lock);
262 ret += scnprintf(buf + ret, PAGE_SIZE - ret, "\n");
266 IRQ_ATTR_RO(actions);
268 static struct attribute *irq_attrs[] = {
269 &per_cpu_count_attr.attr,
270 &chip_name_attr.attr,
278 ATTRIBUTE_GROUPS(irq);
280 static struct kobj_type irq_kobj_type = {
281 .release = irq_kobj_release,
282 .sysfs_ops = &kobj_sysfs_ops,
283 .default_groups = irq_groups,
286 static void irq_sysfs_add(int irq, struct irq_desc *desc)
290 * Continue even in case of failure as this is nothing
293 if (kobject_add(&desc->kobj, irq_kobj_base, "%d", irq))
294 pr_warn("Failed to add kobject for irq %d\n", irq);
298 static void irq_sysfs_del(struct irq_desc *desc)
301 * If irq_sysfs_init() has not yet been invoked (early boot), then
302 * irq_kobj_base is NULL and the descriptor was never added.
303 * kobject_del() complains about a object with no parent, so make
307 kobject_del(&desc->kobj);
310 static int __init irq_sysfs_init(void)
312 struct irq_desc *desc;
315 /* Prevent concurrent irq alloc/free */
318 irq_kobj_base = kobject_create_and_add("irq", kernel_kobj);
319 if (!irq_kobj_base) {
324 /* Add the already allocated interrupts */
325 for_each_irq_desc(irq, desc)
326 irq_sysfs_add(irq, desc);
331 postcore_initcall(irq_sysfs_init);
333 #else /* !CONFIG_SYSFS */
335 static struct kobj_type irq_kobj_type = {
336 .release = irq_kobj_release,
339 static void irq_sysfs_add(int irq, struct irq_desc *desc) {}
340 static void irq_sysfs_del(struct irq_desc *desc) {}
342 #endif /* CONFIG_SYSFS */
344 static RADIX_TREE(irq_desc_tree, GFP_KERNEL);
346 static void irq_insert_desc(unsigned int irq, struct irq_desc *desc)
348 radix_tree_insert(&irq_desc_tree, irq, desc);
351 struct irq_desc *irq_to_desc(unsigned int irq)
353 return radix_tree_lookup(&irq_desc_tree, irq);
355 #ifdef CONFIG_KVM_BOOK3S_64_HV_MODULE
356 EXPORT_SYMBOL_GPL(irq_to_desc);
359 static void delete_irq_desc(unsigned int irq)
361 radix_tree_delete(&irq_desc_tree, irq);
365 static void free_masks(struct irq_desc *desc)
367 #ifdef CONFIG_GENERIC_PENDING_IRQ
368 free_cpumask_var(desc->pending_mask);
370 free_cpumask_var(desc->irq_common_data.affinity);
371 #ifdef CONFIG_GENERIC_IRQ_EFFECTIVE_AFF_MASK
372 free_cpumask_var(desc->irq_common_data.effective_affinity);
376 static inline void free_masks(struct irq_desc *desc) { }
379 void irq_lock_sparse(void)
381 mutex_lock(&sparse_irq_lock);
384 void irq_unlock_sparse(void)
386 mutex_unlock(&sparse_irq_lock);
389 static struct irq_desc *alloc_desc(int irq, int node, unsigned int flags,
390 const struct cpumask *affinity,
391 struct module *owner)
393 struct irq_desc *desc;
395 desc = kzalloc_node(sizeof(*desc), GFP_KERNEL, node);
398 /* allocate based on nr_cpu_ids */
399 desc->kstat_irqs = alloc_percpu(unsigned int);
400 if (!desc->kstat_irqs)
403 if (alloc_masks(desc, node))
406 raw_spin_lock_init(&desc->lock);
407 lockdep_set_class(&desc->lock, &irq_desc_lock_class);
408 mutex_init(&desc->request_mutex);
409 init_rcu_head(&desc->rcu);
411 desc_set_defaults(irq, desc, node, affinity, owner);
412 irqd_set(&desc->irq_data, flags);
413 kobject_init(&desc->kobj, &irq_kobj_type);
418 free_percpu(desc->kstat_irqs);
424 static void irq_kobj_release(struct kobject *kobj)
426 struct irq_desc *desc = container_of(kobj, struct irq_desc, kobj);
429 free_percpu(desc->kstat_irqs);
433 static void delayed_free_desc(struct rcu_head *rhp)
435 struct irq_desc *desc = container_of(rhp, struct irq_desc, rcu);
437 kobject_put(&desc->kobj);
440 static void free_desc(unsigned int irq)
442 struct irq_desc *desc = irq_to_desc(irq);
444 irq_remove_debugfs_entry(desc);
445 unregister_irq_proc(irq, desc);
448 * sparse_irq_lock protects also show_interrupts() and
449 * kstat_irq_usr(). Once we deleted the descriptor from the
450 * sparse tree we can free it. Access in proc will fail to
451 * lookup the descriptor.
453 * The sysfs entry must be serialized against a concurrent
454 * irq_sysfs_init() as well.
457 delete_irq_desc(irq);
460 * We free the descriptor, masks and stat fields via RCU. That
461 * allows demultiplex interrupts to do rcu based management of
462 * the child interrupts.
463 * This also allows us to use rcu in kstat_irqs_usr().
465 call_rcu(&desc->rcu, delayed_free_desc);
468 static int alloc_descs(unsigned int start, unsigned int cnt, int node,
469 const struct irq_affinity_desc *affinity,
470 struct module *owner)
472 struct irq_desc *desc;
475 /* Validate affinity mask(s) */
477 for (i = 0; i < cnt; i++) {
478 if (cpumask_empty(&affinity[i].mask))
483 for (i = 0; i < cnt; i++) {
484 const struct cpumask *mask = NULL;
485 unsigned int flags = 0;
488 if (affinity->is_managed) {
489 flags = IRQD_AFFINITY_MANAGED |
490 IRQD_MANAGED_SHUTDOWN;
492 mask = &affinity->mask;
493 node = cpu_to_node(cpumask_first(mask));
497 desc = alloc_desc(start + i, node, flags, mask, owner);
500 irq_insert_desc(start + i, desc);
501 irq_sysfs_add(start + i, desc);
502 irq_add_debugfs_entry(start + i, desc);
504 bitmap_set(allocated_irqs, start, cnt);
508 for (i--; i >= 0; i--)
509 free_desc(start + i);
513 static int irq_expand_nr_irqs(unsigned int nr)
515 if (nr > IRQ_BITMAP_BITS)
521 int __init early_irq_init(void)
523 int i, initcnt, node = first_online_node;
524 struct irq_desc *desc;
526 init_irq_default_affinity();
528 /* Let arch update nr_irqs and return the nr of preallocated irqs */
529 initcnt = arch_probe_nr_irqs();
530 printk(KERN_INFO "NR_IRQS: %d, nr_irqs: %d, preallocated irqs: %d\n",
531 NR_IRQS, nr_irqs, initcnt);
533 if (WARN_ON(nr_irqs > IRQ_BITMAP_BITS))
534 nr_irqs = IRQ_BITMAP_BITS;
536 if (WARN_ON(initcnt > IRQ_BITMAP_BITS))
537 initcnt = IRQ_BITMAP_BITS;
539 if (initcnt > nr_irqs)
542 for (i = 0; i < initcnt; i++) {
543 desc = alloc_desc(i, node, 0, NULL, NULL);
544 set_bit(i, allocated_irqs);
545 irq_insert_desc(i, desc);
547 return arch_early_irq_init();
550 #else /* !CONFIG_SPARSE_IRQ */
552 struct irq_desc irq_desc[NR_IRQS] __cacheline_aligned_in_smp = {
553 [0 ... NR_IRQS-1] = {
554 .handle_irq = handle_bad_irq,
556 .lock = __RAW_SPIN_LOCK_UNLOCKED(irq_desc->lock),
560 int __init early_irq_init(void)
562 int count, i, node = first_online_node;
563 struct irq_desc *desc;
565 init_irq_default_affinity();
567 printk(KERN_INFO "NR_IRQS: %d\n", NR_IRQS);
570 count = ARRAY_SIZE(irq_desc);
572 for (i = 0; i < count; i++) {
573 desc[i].kstat_irqs = alloc_percpu(unsigned int);
574 alloc_masks(&desc[i], node);
575 raw_spin_lock_init(&desc[i].lock);
576 lockdep_set_class(&desc[i].lock, &irq_desc_lock_class);
577 mutex_init(&desc[i].request_mutex);
578 desc_set_defaults(i, &desc[i], node, NULL, NULL);
580 return arch_early_irq_init();
583 struct irq_desc *irq_to_desc(unsigned int irq)
585 return (irq < NR_IRQS) ? irq_desc + irq : NULL;
587 EXPORT_SYMBOL(irq_to_desc);
589 static void free_desc(unsigned int irq)
591 struct irq_desc *desc = irq_to_desc(irq);
594 raw_spin_lock_irqsave(&desc->lock, flags);
595 desc_set_defaults(irq, desc, irq_desc_get_node(desc), NULL, NULL);
596 raw_spin_unlock_irqrestore(&desc->lock, flags);
599 static inline int alloc_descs(unsigned int start, unsigned int cnt, int node,
600 const struct irq_affinity_desc *affinity,
601 struct module *owner)
605 for (i = 0; i < cnt; i++) {
606 struct irq_desc *desc = irq_to_desc(start + i);
610 bitmap_set(allocated_irqs, start, cnt);
614 static int irq_expand_nr_irqs(unsigned int nr)
619 void irq_mark_irq(unsigned int irq)
621 mutex_lock(&sparse_irq_lock);
622 bitmap_set(allocated_irqs, irq, 1);
623 mutex_unlock(&sparse_irq_lock);
626 #ifdef CONFIG_GENERIC_IRQ_LEGACY
627 void irq_init_desc(unsigned int irq)
633 #endif /* !CONFIG_SPARSE_IRQ */
635 int handle_irq_desc(struct irq_desc *desc)
637 struct irq_data *data;
642 data = irq_desc_get_irq_data(desc);
643 if (WARN_ON_ONCE(!in_irq() && handle_enforce_irqctx(data)))
646 generic_handle_irq_desc(desc);
651 * generic_handle_irq - Invoke the handler for a particular irq
652 * @irq: The irq number to handle
654 * Returns: 0 on success, or -EINVAL if conversion has failed
656 * This function must be called from an IRQ context with irq regs
659 int generic_handle_irq(unsigned int irq)
661 return handle_irq_desc(irq_to_desc(irq));
663 EXPORT_SYMBOL_GPL(generic_handle_irq);
665 #ifdef CONFIG_IRQ_DOMAIN
667 * generic_handle_domain_irq - Invoke the handler for a HW irq belonging
669 * @domain: The domain where to perform the lookup
670 * @hwirq: The HW irq number to convert to a logical one
672 * Returns: 0 on success, or -EINVAL if conversion has failed
674 * This function must be called from an IRQ context with irq regs
677 int generic_handle_domain_irq(struct irq_domain *domain, unsigned int hwirq)
679 WARN_ON_ONCE(!in_irq());
680 return handle_irq_desc(irq_resolve_mapping(domain, hwirq));
682 EXPORT_SYMBOL_GPL(generic_handle_domain_irq);
685 * generic_handle_domain_nmi - Invoke the handler for a HW nmi belonging
687 * @domain: The domain where to perform the lookup
688 * @hwirq: The HW irq number to convert to a logical one
690 * Returns: 0 on success, or -EINVAL if conversion has failed
692 * This function must be called from an NMI context with irq regs
695 int generic_handle_domain_nmi(struct irq_domain *domain, unsigned int hwirq)
697 WARN_ON_ONCE(!in_nmi());
698 return handle_irq_desc(irq_resolve_mapping(domain, hwirq));
702 /* Dynamic interrupt handling */
705 * irq_free_descs - free irq descriptors
706 * @from: Start of descriptor range
707 * @cnt: Number of consecutive irqs to free
709 void irq_free_descs(unsigned int from, unsigned int cnt)
713 if (from >= nr_irqs || (from + cnt) > nr_irqs)
716 mutex_lock(&sparse_irq_lock);
717 for (i = 0; i < cnt; i++)
720 bitmap_clear(allocated_irqs, from, cnt);
721 mutex_unlock(&sparse_irq_lock);
723 EXPORT_SYMBOL_GPL(irq_free_descs);
726 * __irq_alloc_descs - allocate and initialize a range of irq descriptors
727 * @irq: Allocate for specific irq number if irq >= 0
728 * @from: Start the search from this irq number
729 * @cnt: Number of consecutive irqs to allocate.
730 * @node: Preferred node on which the irq descriptor should be allocated
731 * @owner: Owning module (can be NULL)
732 * @affinity: Optional pointer to an affinity mask array of size @cnt which
733 * hints where the irq descriptors should be allocated and which
734 * default affinities to use
736 * Returns the first irq number or error code
739 __irq_alloc_descs(int irq, unsigned int from, unsigned int cnt, int node,
740 struct module *owner, const struct irq_affinity_desc *affinity)
753 * For interrupts which are freely allocated the
754 * architecture can force a lower bound to the @from
755 * argument. x86 uses this to exclude the GSI space.
757 from = arch_dynirq_lower_bound(from);
760 mutex_lock(&sparse_irq_lock);
762 start = bitmap_find_next_zero_area(allocated_irqs, IRQ_BITMAP_BITS,
765 if (irq >=0 && start != irq)
768 if (start + cnt > nr_irqs) {
769 ret = irq_expand_nr_irqs(start + cnt);
773 ret = alloc_descs(start, cnt, node, affinity, owner);
775 mutex_unlock(&sparse_irq_lock);
778 EXPORT_SYMBOL_GPL(__irq_alloc_descs);
781 * irq_get_next_irq - get next allocated irq number
782 * @offset: where to start the search
784 * Returns next irq number after offset or nr_irqs if none is found.
786 unsigned int irq_get_next_irq(unsigned int offset)
788 return find_next_bit(allocated_irqs, nr_irqs, offset);
792 __irq_get_desc_lock(unsigned int irq, unsigned long *flags, bool bus,
795 struct irq_desc *desc = irq_to_desc(irq);
798 if (check & _IRQ_DESC_CHECK) {
799 if ((check & _IRQ_DESC_PERCPU) &&
800 !irq_settings_is_per_cpu_devid(desc))
803 if (!(check & _IRQ_DESC_PERCPU) &&
804 irq_settings_is_per_cpu_devid(desc))
810 raw_spin_lock_irqsave(&desc->lock, *flags);
815 void __irq_put_desc_unlock(struct irq_desc *desc, unsigned long flags, bool bus)
816 __releases(&desc->lock)
818 raw_spin_unlock_irqrestore(&desc->lock, flags);
820 chip_bus_sync_unlock(desc);
823 int irq_set_percpu_devid_partition(unsigned int irq,
824 const struct cpumask *affinity)
826 struct irq_desc *desc = irq_to_desc(irq);
831 if (desc->percpu_enabled)
834 desc->percpu_enabled = kzalloc(sizeof(*desc->percpu_enabled), GFP_KERNEL);
836 if (!desc->percpu_enabled)
840 desc->percpu_affinity = affinity;
842 desc->percpu_affinity = cpu_possible_mask;
844 irq_set_percpu_devid_flags(irq);
848 int irq_set_percpu_devid(unsigned int irq)
850 return irq_set_percpu_devid_partition(irq, NULL);
853 int irq_get_percpu_devid_partition(unsigned int irq, struct cpumask *affinity)
855 struct irq_desc *desc = irq_to_desc(irq);
857 if (!desc || !desc->percpu_enabled)
861 cpumask_copy(affinity, desc->percpu_affinity);
865 EXPORT_SYMBOL_GPL(irq_get_percpu_devid_partition);
867 void kstat_incr_irq_this_cpu(unsigned int irq)
869 kstat_incr_irqs_this_cpu(irq_to_desc(irq));
873 * kstat_irqs_cpu - Get the statistics for an interrupt on a cpu
874 * @irq: The interrupt number
875 * @cpu: The cpu number
877 * Returns the sum of interrupt counts on @cpu since boot for
878 * @irq. The caller must ensure that the interrupt is not removed
881 unsigned int kstat_irqs_cpu(unsigned int irq, int cpu)
883 struct irq_desc *desc = irq_to_desc(irq);
885 return desc && desc->kstat_irqs ?
886 *per_cpu_ptr(desc->kstat_irqs, cpu) : 0;
889 static bool irq_is_nmi(struct irq_desc *desc)
891 return desc->istate & IRQS_NMI;
894 static unsigned int kstat_irqs(unsigned int irq)
896 struct irq_desc *desc = irq_to_desc(irq);
897 unsigned int sum = 0;
900 if (!desc || !desc->kstat_irqs)
902 if (!irq_settings_is_per_cpu_devid(desc) &&
903 !irq_settings_is_per_cpu(desc) &&
905 return data_race(desc->tot_count);
907 for_each_possible_cpu(cpu)
908 sum += data_race(*per_cpu_ptr(desc->kstat_irqs, cpu));
913 * kstat_irqs_usr - Get the statistics for an interrupt from thread context
914 * @irq: The interrupt number
916 * Returns the sum of interrupt counts on all cpus since boot for @irq.
918 * It uses rcu to protect the access since a concurrent removal of an
919 * interrupt descriptor is observing an rcu grace period before
920 * delayed_free_desc()/irq_kobj_release().
922 unsigned int kstat_irqs_usr(unsigned int irq)
927 sum = kstat_irqs(irq);
932 #ifdef CONFIG_LOCKDEP
933 void __irq_set_lockdep_class(unsigned int irq, struct lock_class_key *lock_class,
934 struct lock_class_key *request_class)
936 struct irq_desc *desc = irq_to_desc(irq);
939 lockdep_set_class(&desc->lock, lock_class);
940 lockdep_set_class(&desc->request_mutex, request_class);
943 EXPORT_SYMBOL_GPL(__irq_set_lockdep_class);