2 * Copyright (C) 1992, 1998-2006 Linus Torvalds, Ingo Molnar
3 * Copyright (C) 2005-2006, Thomas Gleixner, Russell King
5 * This file contains the interrupt descriptor management code
7 * Detailed information is available in Documentation/DocBook/genericirq
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 zalloc_cpumask_var(&irq_default_affinity, GFP_NOWAIT);
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 comandline 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 #ifdef CONFIG_CPUMASK_OFFSTACK
44 if (!irq_default_affinity)
45 zalloc_cpumask_var(&irq_default_affinity, GFP_NOWAIT);
47 if (cpumask_empty(irq_default_affinity))
48 cpumask_setall(irq_default_affinity);
51 static void __init init_irq_default_affinity(void)
57 static int alloc_masks(struct irq_desc *desc, gfp_t gfp, int node)
59 if (!zalloc_cpumask_var_node(&desc->irq_common_data.affinity,
63 #ifdef CONFIG_GENERIC_PENDING_IRQ
64 if (!zalloc_cpumask_var_node(&desc->pending_mask, gfp, node)) {
65 free_cpumask_var(desc->irq_common_data.affinity);
72 static void desc_smp_init(struct irq_desc *desc, int node,
73 const struct cpumask *affinity)
76 affinity = irq_default_affinity;
77 cpumask_copy(desc->irq_common_data.affinity, affinity);
79 #ifdef CONFIG_GENERIC_PENDING_IRQ
80 cpumask_clear(desc->pending_mask);
83 desc->irq_common_data.node = node;
89 alloc_masks(struct irq_desc *desc, gfp_t gfp, int node) { return 0; }
91 desc_smp_init(struct irq_desc *desc, int node, const struct cpumask *affinity) { }
94 static void desc_set_defaults(unsigned int irq, struct irq_desc *desc, int node,
95 const struct cpumask *affinity, struct module *owner)
99 desc->irq_common_data.handler_data = NULL;
100 desc->irq_common_data.msi_desc = NULL;
102 desc->irq_data.common = &desc->irq_common_data;
103 desc->irq_data.irq = irq;
104 desc->irq_data.chip = &no_irq_chip;
105 desc->irq_data.chip_data = NULL;
106 irq_settings_clr_and_set(desc, ~0, _IRQ_DEFAULT_INIT_FLAGS);
107 irqd_set(&desc->irq_data, IRQD_IRQ_DISABLED);
108 desc->handle_irq = handle_bad_irq;
111 desc->irqs_unhandled = 0;
114 for_each_possible_cpu(cpu)
115 *per_cpu_ptr(desc->kstat_irqs, cpu) = 0;
116 desc_smp_init(desc, node, affinity);
119 int nr_irqs = NR_IRQS;
120 EXPORT_SYMBOL_GPL(nr_irqs);
122 static DEFINE_MUTEX(sparse_irq_lock);
123 static DECLARE_BITMAP(allocated_irqs, IRQ_BITMAP_BITS);
125 #ifdef CONFIG_SPARSE_IRQ
127 static void irq_kobj_release(struct kobject *kobj);
130 static struct kobject *irq_kobj_base;
132 #define IRQ_ATTR_RO(_name) \
133 static struct kobj_attribute _name##_attr = __ATTR_RO(_name)
135 static ssize_t per_cpu_count_show(struct kobject *kobj,
136 struct kobj_attribute *attr, char *buf)
138 struct irq_desc *desc = container_of(kobj, struct irq_desc, kobj);
139 int cpu, irq = desc->irq_data.irq;
143 for_each_possible_cpu(cpu) {
144 unsigned int c = kstat_irqs_cpu(irq, cpu);
146 ret += scnprintf(buf + ret, PAGE_SIZE - ret, "%s%u", p, c);
150 ret += scnprintf(buf + ret, PAGE_SIZE - ret, "\n");
153 IRQ_ATTR_RO(per_cpu_count);
155 static ssize_t chip_name_show(struct kobject *kobj,
156 struct kobj_attribute *attr, char *buf)
158 struct irq_desc *desc = container_of(kobj, struct irq_desc, kobj);
161 raw_spin_lock_irq(&desc->lock);
162 if (desc->irq_data.chip && desc->irq_data.chip->name) {
163 ret = scnprintf(buf, PAGE_SIZE, "%s\n",
164 desc->irq_data.chip->name);
166 raw_spin_unlock_irq(&desc->lock);
170 IRQ_ATTR_RO(chip_name);
172 static ssize_t hwirq_show(struct kobject *kobj,
173 struct kobj_attribute *attr, char *buf)
175 struct irq_desc *desc = container_of(kobj, struct irq_desc, kobj);
178 raw_spin_lock_irq(&desc->lock);
179 if (desc->irq_data.domain)
180 ret = sprintf(buf, "%d\n", (int)desc->irq_data.hwirq);
181 raw_spin_unlock_irq(&desc->lock);
187 static ssize_t type_show(struct kobject *kobj,
188 struct kobj_attribute *attr, char *buf)
190 struct irq_desc *desc = container_of(kobj, struct irq_desc, kobj);
193 raw_spin_lock_irq(&desc->lock);
194 ret = sprintf(buf, "%s\n",
195 irqd_is_level_type(&desc->irq_data) ? "level" : "edge");
196 raw_spin_unlock_irq(&desc->lock);
203 static ssize_t name_show(struct kobject *kobj,
204 struct kobj_attribute *attr, char *buf)
206 struct irq_desc *desc = container_of(kobj, struct irq_desc, kobj);
209 raw_spin_lock_irq(&desc->lock);
211 ret = scnprintf(buf, PAGE_SIZE, "%s\n", desc->name);
212 raw_spin_unlock_irq(&desc->lock);
218 static ssize_t actions_show(struct kobject *kobj,
219 struct kobj_attribute *attr, char *buf)
221 struct irq_desc *desc = container_of(kobj, struct irq_desc, kobj);
222 struct irqaction *action;
226 raw_spin_lock_irq(&desc->lock);
227 for (action = desc->action; action != NULL; action = action->next) {
228 ret += scnprintf(buf + ret, PAGE_SIZE - ret, "%s%s",
232 raw_spin_unlock_irq(&desc->lock);
235 ret += scnprintf(buf + ret, PAGE_SIZE - ret, "\n");
239 IRQ_ATTR_RO(actions);
241 static struct attribute *irq_attrs[] = {
242 &per_cpu_count_attr.attr,
243 &chip_name_attr.attr,
251 static struct kobj_type irq_kobj_type = {
252 .release = irq_kobj_release,
253 .sysfs_ops = &kobj_sysfs_ops,
254 .default_attrs = irq_attrs,
257 static void irq_sysfs_add(int irq, struct irq_desc *desc)
261 * Continue even in case of failure as this is nothing
264 if (kobject_add(&desc->kobj, irq_kobj_base, "%d", irq))
265 pr_warn("Failed to add kobject for irq %d\n", irq);
269 static int __init irq_sysfs_init(void)
271 struct irq_desc *desc;
274 /* Prevent concurrent irq alloc/free */
277 irq_kobj_base = kobject_create_and_add("irq", kernel_kobj);
278 if (!irq_kobj_base) {
283 /* Add the already allocated interrupts */
284 for_each_irq_desc(irq, desc)
285 irq_sysfs_add(irq, desc);
290 postcore_initcall(irq_sysfs_init);
292 #else /* !CONFIG_SYSFS */
294 static struct kobj_type irq_kobj_type = {
295 .release = irq_kobj_release,
298 static void irq_sysfs_add(int irq, struct irq_desc *desc) {}
300 #endif /* CONFIG_SYSFS */
302 static RADIX_TREE(irq_desc_tree, GFP_KERNEL);
304 static void irq_insert_desc(unsigned int irq, struct irq_desc *desc)
306 radix_tree_insert(&irq_desc_tree, irq, desc);
309 struct irq_desc *irq_to_desc(unsigned int irq)
311 return radix_tree_lookup(&irq_desc_tree, irq);
313 EXPORT_SYMBOL(irq_to_desc);
315 static void delete_irq_desc(unsigned int irq)
317 radix_tree_delete(&irq_desc_tree, irq);
321 static void free_masks(struct irq_desc *desc)
323 #ifdef CONFIG_GENERIC_PENDING_IRQ
324 free_cpumask_var(desc->pending_mask);
326 free_cpumask_var(desc->irq_common_data.affinity);
329 static inline void free_masks(struct irq_desc *desc) { }
332 void irq_lock_sparse(void)
334 mutex_lock(&sparse_irq_lock);
337 void irq_unlock_sparse(void)
339 mutex_unlock(&sparse_irq_lock);
342 static struct irq_desc *alloc_desc(int irq, int node, unsigned int flags,
343 const struct cpumask *affinity,
344 struct module *owner)
346 struct irq_desc *desc;
347 gfp_t gfp = GFP_KERNEL;
349 desc = kzalloc_node(sizeof(*desc), gfp, node);
352 /* allocate based on nr_cpu_ids */
353 desc->kstat_irqs = alloc_percpu(unsigned int);
354 if (!desc->kstat_irqs)
357 if (alloc_masks(desc, gfp, node))
360 raw_spin_lock_init(&desc->lock);
361 lockdep_set_class(&desc->lock, &irq_desc_lock_class);
362 init_rcu_head(&desc->rcu);
364 desc_set_defaults(irq, desc, node, affinity, owner);
365 irqd_set(&desc->irq_data, flags);
366 kobject_init(&desc->kobj, &irq_kobj_type);
371 free_percpu(desc->kstat_irqs);
377 static void irq_kobj_release(struct kobject *kobj)
379 struct irq_desc *desc = container_of(kobj, struct irq_desc, kobj);
382 free_percpu(desc->kstat_irqs);
386 static void delayed_free_desc(struct rcu_head *rhp)
388 struct irq_desc *desc = container_of(rhp, struct irq_desc, rcu);
390 kobject_put(&desc->kobj);
393 static void free_desc(unsigned int irq)
395 struct irq_desc *desc = irq_to_desc(irq);
397 unregister_irq_proc(irq, desc);
400 * sparse_irq_lock protects also show_interrupts() and
401 * kstat_irq_usr(). Once we deleted the descriptor from the
402 * sparse tree we can free it. Access in proc will fail to
403 * lookup the descriptor.
405 * The sysfs entry must be serialized against a concurrent
406 * irq_sysfs_init() as well.
408 mutex_lock(&sparse_irq_lock);
409 kobject_del(&desc->kobj);
410 delete_irq_desc(irq);
411 mutex_unlock(&sparse_irq_lock);
414 * We free the descriptor, masks and stat fields via RCU. That
415 * allows demultiplex interrupts to do rcu based management of
416 * the child interrupts.
418 call_rcu(&desc->rcu, delayed_free_desc);
421 static int alloc_descs(unsigned int start, unsigned int cnt, int node,
422 const struct cpumask *affinity, struct module *owner)
424 const struct cpumask *mask = NULL;
425 struct irq_desc *desc;
429 /* Validate affinity mask(s) */
431 for (i = 0, mask = affinity; i < cnt; i++, mask++) {
432 if (cpumask_empty(mask))
437 flags = affinity ? IRQD_AFFINITY_MANAGED : 0;
440 for (i = 0; i < cnt; i++) {
442 node = cpu_to_node(cpumask_first(affinity));
446 desc = alloc_desc(start + i, node, flags, mask, owner);
449 mutex_lock(&sparse_irq_lock);
450 irq_insert_desc(start + i, desc);
451 irq_sysfs_add(start + i, desc);
452 mutex_unlock(&sparse_irq_lock);
457 for (i--; i >= 0; i--)
458 free_desc(start + i);
460 mutex_lock(&sparse_irq_lock);
461 bitmap_clear(allocated_irqs, start, cnt);
462 mutex_unlock(&sparse_irq_lock);
466 static int irq_expand_nr_irqs(unsigned int nr)
468 if (nr > IRQ_BITMAP_BITS)
474 int __init early_irq_init(void)
476 int i, initcnt, node = first_online_node;
477 struct irq_desc *desc;
479 init_irq_default_affinity();
481 /* Let arch update nr_irqs and return the nr of preallocated irqs */
482 initcnt = arch_probe_nr_irqs();
483 printk(KERN_INFO "NR_IRQS:%d nr_irqs:%d %d\n", NR_IRQS, nr_irqs, initcnt);
485 if (WARN_ON(nr_irqs > IRQ_BITMAP_BITS))
486 nr_irqs = IRQ_BITMAP_BITS;
488 if (WARN_ON(initcnt > IRQ_BITMAP_BITS))
489 initcnt = IRQ_BITMAP_BITS;
491 if (initcnt > nr_irqs)
494 for (i = 0; i < initcnt; i++) {
495 desc = alloc_desc(i, node, 0, NULL, NULL);
496 set_bit(i, allocated_irqs);
497 irq_insert_desc(i, desc);
499 return arch_early_irq_init();
502 #else /* !CONFIG_SPARSE_IRQ */
504 struct irq_desc irq_desc[NR_IRQS] __cacheline_aligned_in_smp = {
505 [0 ... NR_IRQS-1] = {
506 .handle_irq = handle_bad_irq,
508 .lock = __RAW_SPIN_LOCK_UNLOCKED(irq_desc->lock),
512 int __init early_irq_init(void)
514 int count, i, node = first_online_node;
515 struct irq_desc *desc;
517 init_irq_default_affinity();
519 printk(KERN_INFO "NR_IRQS:%d\n", NR_IRQS);
522 count = ARRAY_SIZE(irq_desc);
524 for (i = 0; i < count; i++) {
525 desc[i].kstat_irqs = alloc_percpu(unsigned int);
526 alloc_masks(&desc[i], GFP_KERNEL, node);
527 raw_spin_lock_init(&desc[i].lock);
528 lockdep_set_class(&desc[i].lock, &irq_desc_lock_class);
529 desc_set_defaults(i, &desc[i], node, NULL, NULL);
531 return arch_early_irq_init();
534 struct irq_desc *irq_to_desc(unsigned int irq)
536 return (irq < NR_IRQS) ? irq_desc + irq : NULL;
538 EXPORT_SYMBOL(irq_to_desc);
540 static void free_desc(unsigned int irq)
542 struct irq_desc *desc = irq_to_desc(irq);
545 raw_spin_lock_irqsave(&desc->lock, flags);
546 desc_set_defaults(irq, desc, irq_desc_get_node(desc), NULL, NULL);
547 raw_spin_unlock_irqrestore(&desc->lock, flags);
550 static inline int alloc_descs(unsigned int start, unsigned int cnt, int node,
551 const struct cpumask *affinity,
552 struct module *owner)
556 for (i = 0; i < cnt; i++) {
557 struct irq_desc *desc = irq_to_desc(start + i);
564 static int irq_expand_nr_irqs(unsigned int nr)
569 void irq_mark_irq(unsigned int irq)
571 mutex_lock(&sparse_irq_lock);
572 bitmap_set(allocated_irqs, irq, 1);
573 mutex_unlock(&sparse_irq_lock);
576 #ifdef CONFIG_GENERIC_IRQ_LEGACY
577 void irq_init_desc(unsigned int irq)
583 #endif /* !CONFIG_SPARSE_IRQ */
586 * generic_handle_irq - Invoke the handler for a particular irq
587 * @irq: The irq number to handle
590 int generic_handle_irq(unsigned int irq)
592 struct irq_desc *desc = irq_to_desc(irq);
596 generic_handle_irq_desc(desc);
599 EXPORT_SYMBOL_GPL(generic_handle_irq);
601 #ifdef CONFIG_HANDLE_DOMAIN_IRQ
603 * __handle_domain_irq - Invoke the handler for a HW irq belonging to a domain
604 * @domain: The domain where to perform the lookup
605 * @hwirq: The HW irq number to convert to a logical one
606 * @lookup: Whether to perform the domain lookup or not
607 * @regs: Register file coming from the low-level handling code
609 * Returns: 0 on success, or -EINVAL if conversion has failed
611 int __handle_domain_irq(struct irq_domain *domain, unsigned int hwirq,
612 bool lookup, struct pt_regs *regs)
614 struct pt_regs *old_regs = set_irq_regs(regs);
615 unsigned int irq = hwirq;
620 #ifdef CONFIG_IRQ_DOMAIN
622 irq = irq_find_mapping(domain, hwirq);
626 * Some hardware gives randomly wrong interrupts. Rather
627 * than crashing, do something sensible.
629 if (unlikely(!irq || irq >= nr_irqs)) {
633 generic_handle_irq(irq);
637 set_irq_regs(old_regs);
642 /* Dynamic interrupt handling */
645 * irq_free_descs - free irq descriptors
646 * @from: Start of descriptor range
647 * @cnt: Number of consecutive irqs to free
649 void irq_free_descs(unsigned int from, unsigned int cnt)
653 if (from >= nr_irqs || (from + cnt) > nr_irqs)
656 for (i = 0; i < cnt; i++)
659 mutex_lock(&sparse_irq_lock);
660 bitmap_clear(allocated_irqs, from, cnt);
661 mutex_unlock(&sparse_irq_lock);
663 EXPORT_SYMBOL_GPL(irq_free_descs);
666 * irq_alloc_descs - allocate and initialize a range of irq descriptors
667 * @irq: Allocate for specific irq number if irq >= 0
668 * @from: Start the search from this irq number
669 * @cnt: Number of consecutive irqs to allocate.
670 * @node: Preferred node on which the irq descriptor should be allocated
671 * @owner: Owning module (can be NULL)
672 * @affinity: Optional pointer to an affinity mask array of size @cnt which
673 * hints where the irq descriptors should be allocated and which
674 * default affinities to use
676 * Returns the first irq number or error code
679 __irq_alloc_descs(int irq, unsigned int from, unsigned int cnt, int node,
680 struct module *owner, const struct cpumask *affinity)
693 * For interrupts which are freely allocated the
694 * architecture can force a lower bound to the @from
695 * argument. x86 uses this to exclude the GSI space.
697 from = arch_dynirq_lower_bound(from);
700 mutex_lock(&sparse_irq_lock);
702 start = bitmap_find_next_zero_area(allocated_irqs, IRQ_BITMAP_BITS,
705 if (irq >=0 && start != irq)
708 if (start + cnt > nr_irqs) {
709 ret = irq_expand_nr_irqs(start + cnt);
714 bitmap_set(allocated_irqs, start, cnt);
715 mutex_unlock(&sparse_irq_lock);
716 return alloc_descs(start, cnt, node, affinity, owner);
719 mutex_unlock(&sparse_irq_lock);
722 EXPORT_SYMBOL_GPL(__irq_alloc_descs);
724 #ifdef CONFIG_GENERIC_IRQ_LEGACY_ALLOC_HWIRQ
726 * irq_alloc_hwirqs - Allocate an irq descriptor and initialize the hardware
727 * @cnt: number of interrupts to allocate
728 * @node: node on which to allocate
730 * Returns an interrupt number > 0 or 0, if the allocation fails.
732 unsigned int irq_alloc_hwirqs(int cnt, int node)
734 int i, irq = __irq_alloc_descs(-1, 0, cnt, node, NULL, NULL);
739 for (i = irq; cnt > 0; i++, cnt--) {
740 if (arch_setup_hwirq(i, node))
742 irq_clear_status_flags(i, _IRQ_NOREQUEST);
747 for (i--; i >= irq; i--) {
748 irq_set_status_flags(i, _IRQ_NOREQUEST | _IRQ_NOPROBE);
749 arch_teardown_hwirq(i);
751 irq_free_descs(irq, cnt);
754 EXPORT_SYMBOL_GPL(irq_alloc_hwirqs);
757 * irq_free_hwirqs - Free irq descriptor and cleanup the hardware
758 * @from: Free from irq number
759 * @cnt: number of interrupts to free
762 void irq_free_hwirqs(unsigned int from, int cnt)
766 for (i = from, j = cnt; j > 0; i++, j--) {
767 irq_set_status_flags(i, _IRQ_NOREQUEST | _IRQ_NOPROBE);
768 arch_teardown_hwirq(i);
770 irq_free_descs(from, cnt);
772 EXPORT_SYMBOL_GPL(irq_free_hwirqs);
776 * irq_get_next_irq - get next allocated irq number
777 * @offset: where to start the search
779 * Returns next irq number after offset or nr_irqs if none is found.
781 unsigned int irq_get_next_irq(unsigned int offset)
783 return find_next_bit(allocated_irqs, nr_irqs, offset);
787 __irq_get_desc_lock(unsigned int irq, unsigned long *flags, bool bus,
790 struct irq_desc *desc = irq_to_desc(irq);
793 if (check & _IRQ_DESC_CHECK) {
794 if ((check & _IRQ_DESC_PERCPU) &&
795 !irq_settings_is_per_cpu_devid(desc))
798 if (!(check & _IRQ_DESC_PERCPU) &&
799 irq_settings_is_per_cpu_devid(desc))
805 raw_spin_lock_irqsave(&desc->lock, *flags);
810 void __irq_put_desc_unlock(struct irq_desc *desc, unsigned long flags, bool bus)
812 raw_spin_unlock_irqrestore(&desc->lock, flags);
814 chip_bus_sync_unlock(desc);
817 int irq_set_percpu_devid_partition(unsigned int irq,
818 const struct cpumask *affinity)
820 struct irq_desc *desc = irq_to_desc(irq);
825 if (desc->percpu_enabled)
828 desc->percpu_enabled = kzalloc(sizeof(*desc->percpu_enabled), GFP_KERNEL);
830 if (!desc->percpu_enabled)
834 desc->percpu_affinity = affinity;
836 desc->percpu_affinity = cpu_possible_mask;
838 irq_set_percpu_devid_flags(irq);
842 int irq_set_percpu_devid(unsigned int irq)
844 return irq_set_percpu_devid_partition(irq, NULL);
847 int irq_get_percpu_devid_partition(unsigned int irq, struct cpumask *affinity)
849 struct irq_desc *desc = irq_to_desc(irq);
851 if (!desc || !desc->percpu_enabled)
855 cpumask_copy(affinity, desc->percpu_affinity);
860 void kstat_incr_irq_this_cpu(unsigned int irq)
862 kstat_incr_irqs_this_cpu(irq_to_desc(irq));
866 * kstat_irqs_cpu - Get the statistics for an interrupt on a cpu
867 * @irq: The interrupt number
868 * @cpu: The cpu number
870 * Returns the sum of interrupt counts on @cpu since boot for
871 * @irq. The caller must ensure that the interrupt is not removed
874 unsigned int kstat_irqs_cpu(unsigned int irq, int cpu)
876 struct irq_desc *desc = irq_to_desc(irq);
878 return desc && desc->kstat_irqs ?
879 *per_cpu_ptr(desc->kstat_irqs, cpu) : 0;
883 * kstat_irqs - Get the statistics for an interrupt
884 * @irq: The interrupt number
886 * Returns the sum of interrupt counts on all cpus since boot for
887 * @irq. The caller must ensure that the interrupt is not removed
890 unsigned int kstat_irqs(unsigned int irq)
892 struct irq_desc *desc = irq_to_desc(irq);
894 unsigned int sum = 0;
896 if (!desc || !desc->kstat_irqs)
898 for_each_possible_cpu(cpu)
899 sum += *per_cpu_ptr(desc->kstat_irqs, cpu);
904 * kstat_irqs_usr - Get the statistics for an interrupt
905 * @irq: The interrupt number
907 * Returns the sum of interrupt counts on all cpus since boot for
908 * @irq. Contrary to kstat_irqs() this can be called from any
909 * preemptible context. It's protected against concurrent removal of
910 * an interrupt descriptor when sparse irqs are enabled.
912 unsigned int kstat_irqs_usr(unsigned int irq)
917 sum = kstat_irqs(irq);