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>
19 #include "internals.h"
22 * lockdep: we want to handle all irq_desc locks as a single lock-class:
24 static struct lock_class_key irq_desc_lock_class;
26 #if defined(CONFIG_SMP)
27 static int __init irq_affinity_setup(char *str)
29 zalloc_cpumask_var(&irq_default_affinity, GFP_NOWAIT);
30 cpulist_parse(str, irq_default_affinity);
32 * Set at least the boot cpu. We don't want to end up with
33 * bugreports caused by random comandline masks
35 cpumask_set_cpu(smp_processor_id(), irq_default_affinity);
38 __setup("irqaffinity=", irq_affinity_setup);
40 static void __init init_irq_default_affinity(void)
42 #ifdef CONFIG_CPUMASK_OFFSTACK
43 if (!irq_default_affinity)
44 zalloc_cpumask_var(&irq_default_affinity, GFP_NOWAIT);
46 if (cpumask_empty(irq_default_affinity))
47 cpumask_setall(irq_default_affinity);
50 static void __init init_irq_default_affinity(void)
56 static int alloc_masks(struct irq_desc *desc, gfp_t gfp, int node)
58 if (!zalloc_cpumask_var_node(&desc->irq_common_data.affinity,
62 #ifdef CONFIG_GENERIC_PENDING_IRQ
63 if (!zalloc_cpumask_var_node(&desc->pending_mask, gfp, node)) {
64 free_cpumask_var(desc->irq_common_data.affinity);
71 static void desc_smp_init(struct irq_desc *desc, int node)
73 cpumask_copy(desc->irq_common_data.affinity, irq_default_affinity);
74 #ifdef CONFIG_GENERIC_PENDING_IRQ
75 cpumask_clear(desc->pending_mask);
78 desc->irq_common_data.node = node;
84 alloc_masks(struct irq_desc *desc, gfp_t gfp, int node) { return 0; }
85 static inline void desc_smp_init(struct irq_desc *desc, int node) { }
88 static void desc_set_defaults(unsigned int irq, struct irq_desc *desc, int node,
93 desc->irq_common_data.handler_data = NULL;
94 desc->irq_common_data.msi_desc = NULL;
96 desc->irq_data.common = &desc->irq_common_data;
97 desc->irq_data.irq = irq;
98 desc->irq_data.chip = &no_irq_chip;
99 desc->irq_data.chip_data = NULL;
100 irq_settings_clr_and_set(desc, ~0, _IRQ_DEFAULT_INIT_FLAGS);
101 irqd_set(&desc->irq_data, IRQD_IRQ_DISABLED);
102 desc->handle_irq = handle_bad_irq;
105 desc->irqs_unhandled = 0;
108 for_each_possible_cpu(cpu)
109 *per_cpu_ptr(desc->kstat_irqs, cpu) = 0;
110 desc_smp_init(desc, node);
113 int nr_irqs = NR_IRQS;
114 EXPORT_SYMBOL_GPL(nr_irqs);
116 static DEFINE_MUTEX(sparse_irq_lock);
117 static DECLARE_BITMAP(allocated_irqs, IRQ_BITMAP_BITS);
119 #ifdef CONFIG_SPARSE_IRQ
121 static RADIX_TREE(irq_desc_tree, GFP_KERNEL);
123 static void irq_insert_desc(unsigned int irq, struct irq_desc *desc)
125 radix_tree_insert(&irq_desc_tree, irq, desc);
128 struct irq_desc *irq_to_desc(unsigned int irq)
130 return radix_tree_lookup(&irq_desc_tree, irq);
132 EXPORT_SYMBOL(irq_to_desc);
134 static void delete_irq_desc(unsigned int irq)
136 radix_tree_delete(&irq_desc_tree, irq);
140 static void free_masks(struct irq_desc *desc)
142 #ifdef CONFIG_GENERIC_PENDING_IRQ
143 free_cpumask_var(desc->pending_mask);
145 free_cpumask_var(desc->irq_common_data.affinity);
148 static inline void free_masks(struct irq_desc *desc) { }
151 void irq_lock_sparse(void)
153 mutex_lock(&sparse_irq_lock);
156 void irq_unlock_sparse(void)
158 mutex_unlock(&sparse_irq_lock);
161 static struct irq_desc *alloc_desc(int irq, int node, struct module *owner)
163 struct irq_desc *desc;
164 gfp_t gfp = GFP_KERNEL;
166 desc = kzalloc_node(sizeof(*desc), gfp, node);
169 /* allocate based on nr_cpu_ids */
170 desc->kstat_irqs = alloc_percpu(unsigned int);
171 if (!desc->kstat_irqs)
174 if (alloc_masks(desc, gfp, node))
177 raw_spin_lock_init(&desc->lock);
178 lockdep_set_class(&desc->lock, &irq_desc_lock_class);
179 init_rcu_head(&desc->rcu);
181 desc_set_defaults(irq, desc, node, owner);
186 free_percpu(desc->kstat_irqs);
192 static void delayed_free_desc(struct rcu_head *rhp)
194 struct irq_desc *desc = container_of(rhp, struct irq_desc, rcu);
197 free_percpu(desc->kstat_irqs);
201 static void free_desc(unsigned int irq)
203 struct irq_desc *desc = irq_to_desc(irq);
205 unregister_irq_proc(irq, desc);
208 * sparse_irq_lock protects also show_interrupts() and
209 * kstat_irq_usr(). Once we deleted the descriptor from the
210 * sparse tree we can free it. Access in proc will fail to
211 * lookup the descriptor.
213 mutex_lock(&sparse_irq_lock);
214 delete_irq_desc(irq);
215 mutex_unlock(&sparse_irq_lock);
218 * We free the descriptor, masks and stat fields via RCU. That
219 * allows demultiplex interrupts to do rcu based management of
220 * the child interrupts.
222 call_rcu(&desc->rcu, delayed_free_desc);
225 static int alloc_descs(unsigned int start, unsigned int cnt, int node,
226 const struct cpumask *affinity, struct module *owner)
228 struct irq_desc *desc;
231 for (i = 0; i < cnt; i++) {
232 desc = alloc_desc(start + i, node, owner);
235 mutex_lock(&sparse_irq_lock);
236 irq_insert_desc(start + i, desc);
237 mutex_unlock(&sparse_irq_lock);
242 for (i--; i >= 0; i--)
243 free_desc(start + i);
245 mutex_lock(&sparse_irq_lock);
246 bitmap_clear(allocated_irqs, start, cnt);
247 mutex_unlock(&sparse_irq_lock);
251 static int irq_expand_nr_irqs(unsigned int nr)
253 if (nr > IRQ_BITMAP_BITS)
259 int __init early_irq_init(void)
261 int i, initcnt, node = first_online_node;
262 struct irq_desc *desc;
264 init_irq_default_affinity();
266 /* Let arch update nr_irqs and return the nr of preallocated irqs */
267 initcnt = arch_probe_nr_irqs();
268 printk(KERN_INFO "NR_IRQS:%d nr_irqs:%d %d\n", NR_IRQS, nr_irqs, initcnt);
270 if (WARN_ON(nr_irqs > IRQ_BITMAP_BITS))
271 nr_irqs = IRQ_BITMAP_BITS;
273 if (WARN_ON(initcnt > IRQ_BITMAP_BITS))
274 initcnt = IRQ_BITMAP_BITS;
276 if (initcnt > nr_irqs)
279 for (i = 0; i < initcnt; i++) {
280 desc = alloc_desc(i, node, NULL);
281 set_bit(i, allocated_irqs);
282 irq_insert_desc(i, desc);
284 return arch_early_irq_init();
287 #else /* !CONFIG_SPARSE_IRQ */
289 struct irq_desc irq_desc[NR_IRQS] __cacheline_aligned_in_smp = {
290 [0 ... NR_IRQS-1] = {
291 .handle_irq = handle_bad_irq,
293 .lock = __RAW_SPIN_LOCK_UNLOCKED(irq_desc->lock),
297 int __init early_irq_init(void)
299 int count, i, node = first_online_node;
300 struct irq_desc *desc;
302 init_irq_default_affinity();
304 printk(KERN_INFO "NR_IRQS:%d\n", NR_IRQS);
307 count = ARRAY_SIZE(irq_desc);
309 for (i = 0; i < count; i++) {
310 desc[i].kstat_irqs = alloc_percpu(unsigned int);
311 alloc_masks(&desc[i], GFP_KERNEL, node);
312 raw_spin_lock_init(&desc[i].lock);
313 lockdep_set_class(&desc[i].lock, &irq_desc_lock_class);
314 desc_set_defaults(i, &desc[i], node, NULL);
316 return arch_early_irq_init();
319 struct irq_desc *irq_to_desc(unsigned int irq)
321 return (irq < NR_IRQS) ? irq_desc + irq : NULL;
323 EXPORT_SYMBOL(irq_to_desc);
325 static void free_desc(unsigned int irq)
327 struct irq_desc *desc = irq_to_desc(irq);
330 raw_spin_lock_irqsave(&desc->lock, flags);
331 desc_set_defaults(irq, desc, irq_desc_get_node(desc), NULL);
332 raw_spin_unlock_irqrestore(&desc->lock, flags);
335 static inline int alloc_descs(unsigned int start, unsigned int cnt, int node,
336 const struct cpumask *affinity,
337 struct module *owner)
341 for (i = 0; i < cnt; i++) {
342 struct irq_desc *desc = irq_to_desc(start + i);
349 static int irq_expand_nr_irqs(unsigned int nr)
354 void irq_mark_irq(unsigned int irq)
356 mutex_lock(&sparse_irq_lock);
357 bitmap_set(allocated_irqs, irq, 1);
358 mutex_unlock(&sparse_irq_lock);
361 #ifdef CONFIG_GENERIC_IRQ_LEGACY
362 void irq_init_desc(unsigned int irq)
368 #endif /* !CONFIG_SPARSE_IRQ */
371 * generic_handle_irq - Invoke the handler for a particular irq
372 * @irq: The irq number to handle
375 int generic_handle_irq(unsigned int irq)
377 struct irq_desc *desc = irq_to_desc(irq);
381 generic_handle_irq_desc(desc);
384 EXPORT_SYMBOL_GPL(generic_handle_irq);
386 #ifdef CONFIG_HANDLE_DOMAIN_IRQ
388 * __handle_domain_irq - Invoke the handler for a HW irq belonging to a domain
389 * @domain: The domain where to perform the lookup
390 * @hwirq: The HW irq number to convert to a logical one
391 * @lookup: Whether to perform the domain lookup or not
392 * @regs: Register file coming from the low-level handling code
394 * Returns: 0 on success, or -EINVAL if conversion has failed
396 int __handle_domain_irq(struct irq_domain *domain, unsigned int hwirq,
397 bool lookup, struct pt_regs *regs)
399 struct pt_regs *old_regs = set_irq_regs(regs);
400 unsigned int irq = hwirq;
405 #ifdef CONFIG_IRQ_DOMAIN
407 irq = irq_find_mapping(domain, hwirq);
411 * Some hardware gives randomly wrong interrupts. Rather
412 * than crashing, do something sensible.
414 if (unlikely(!irq || irq >= nr_irqs)) {
418 generic_handle_irq(irq);
422 set_irq_regs(old_regs);
427 /* Dynamic interrupt handling */
430 * irq_free_descs - free irq descriptors
431 * @from: Start of descriptor range
432 * @cnt: Number of consecutive irqs to free
434 void irq_free_descs(unsigned int from, unsigned int cnt)
438 if (from >= nr_irqs || (from + cnt) > nr_irqs)
441 for (i = 0; i < cnt; i++)
444 mutex_lock(&sparse_irq_lock);
445 bitmap_clear(allocated_irqs, from, cnt);
446 mutex_unlock(&sparse_irq_lock);
448 EXPORT_SYMBOL_GPL(irq_free_descs);
451 * irq_alloc_descs - allocate and initialize a range of irq descriptors
452 * @irq: Allocate for specific irq number if irq >= 0
453 * @from: Start the search from this irq number
454 * @cnt: Number of consecutive irqs to allocate.
455 * @node: Preferred node on which the irq descriptor should be allocated
456 * @owner: Owning module (can be NULL)
457 * @affinity: Optional pointer to an affinity mask which hints where the
458 * irq descriptors should be allocated and which default
461 * Returns the first irq number or error code
464 __irq_alloc_descs(int irq, unsigned int from, unsigned int cnt, int node,
465 struct module *owner, const struct cpumask *affinity)
478 * For interrupts which are freely allocated the
479 * architecture can force a lower bound to the @from
480 * argument. x86 uses this to exclude the GSI space.
482 from = arch_dynirq_lower_bound(from);
485 mutex_lock(&sparse_irq_lock);
487 start = bitmap_find_next_zero_area(allocated_irqs, IRQ_BITMAP_BITS,
490 if (irq >=0 && start != irq)
493 if (start + cnt > nr_irqs) {
494 ret = irq_expand_nr_irqs(start + cnt);
499 bitmap_set(allocated_irqs, start, cnt);
500 mutex_unlock(&sparse_irq_lock);
501 return alloc_descs(start, cnt, node, affinity, owner);
504 mutex_unlock(&sparse_irq_lock);
507 EXPORT_SYMBOL_GPL(__irq_alloc_descs);
509 #ifdef CONFIG_GENERIC_IRQ_LEGACY_ALLOC_HWIRQ
511 * irq_alloc_hwirqs - Allocate an irq descriptor and initialize the hardware
512 * @cnt: number of interrupts to allocate
513 * @node: node on which to allocate
515 * Returns an interrupt number > 0 or 0, if the allocation fails.
517 unsigned int irq_alloc_hwirqs(int cnt, int node)
519 int i, irq = __irq_alloc_descs(-1, 0, cnt, node, NULL, NULL);
524 for (i = irq; cnt > 0; i++, cnt--) {
525 if (arch_setup_hwirq(i, node))
527 irq_clear_status_flags(i, _IRQ_NOREQUEST);
532 for (i--; i >= irq; i--) {
533 irq_set_status_flags(i, _IRQ_NOREQUEST | _IRQ_NOPROBE);
534 arch_teardown_hwirq(i);
536 irq_free_descs(irq, cnt);
539 EXPORT_SYMBOL_GPL(irq_alloc_hwirqs);
542 * irq_free_hwirqs - Free irq descriptor and cleanup the hardware
543 * @from: Free from irq number
544 * @cnt: number of interrupts to free
547 void irq_free_hwirqs(unsigned int from, int cnt)
551 for (i = from, j = cnt; j > 0; i++, j--) {
552 irq_set_status_flags(i, _IRQ_NOREQUEST | _IRQ_NOPROBE);
553 arch_teardown_hwirq(i);
555 irq_free_descs(from, cnt);
557 EXPORT_SYMBOL_GPL(irq_free_hwirqs);
561 * irq_get_next_irq - get next allocated irq number
562 * @offset: where to start the search
564 * Returns next irq number after offset or nr_irqs if none is found.
566 unsigned int irq_get_next_irq(unsigned int offset)
568 return find_next_bit(allocated_irqs, nr_irqs, offset);
572 __irq_get_desc_lock(unsigned int irq, unsigned long *flags, bool bus,
575 struct irq_desc *desc = irq_to_desc(irq);
578 if (check & _IRQ_DESC_CHECK) {
579 if ((check & _IRQ_DESC_PERCPU) &&
580 !irq_settings_is_per_cpu_devid(desc))
583 if (!(check & _IRQ_DESC_PERCPU) &&
584 irq_settings_is_per_cpu_devid(desc))
590 raw_spin_lock_irqsave(&desc->lock, *flags);
595 void __irq_put_desc_unlock(struct irq_desc *desc, unsigned long flags, bool bus)
597 raw_spin_unlock_irqrestore(&desc->lock, flags);
599 chip_bus_sync_unlock(desc);
602 int irq_set_percpu_devid_partition(unsigned int irq,
603 const struct cpumask *affinity)
605 struct irq_desc *desc = irq_to_desc(irq);
610 if (desc->percpu_enabled)
613 desc->percpu_enabled = kzalloc(sizeof(*desc->percpu_enabled), GFP_KERNEL);
615 if (!desc->percpu_enabled)
619 desc->percpu_affinity = affinity;
621 desc->percpu_affinity = cpu_possible_mask;
623 irq_set_percpu_devid_flags(irq);
627 int irq_set_percpu_devid(unsigned int irq)
629 return irq_set_percpu_devid_partition(irq, NULL);
632 int irq_get_percpu_devid_partition(unsigned int irq, struct cpumask *affinity)
634 struct irq_desc *desc = irq_to_desc(irq);
636 if (!desc || !desc->percpu_enabled)
640 cpumask_copy(affinity, desc->percpu_affinity);
645 void kstat_incr_irq_this_cpu(unsigned int irq)
647 kstat_incr_irqs_this_cpu(irq_to_desc(irq));
651 * kstat_irqs_cpu - Get the statistics for an interrupt on a cpu
652 * @irq: The interrupt number
653 * @cpu: The cpu number
655 * Returns the sum of interrupt counts on @cpu since boot for
656 * @irq. The caller must ensure that the interrupt is not removed
659 unsigned int kstat_irqs_cpu(unsigned int irq, int cpu)
661 struct irq_desc *desc = irq_to_desc(irq);
663 return desc && desc->kstat_irqs ?
664 *per_cpu_ptr(desc->kstat_irqs, cpu) : 0;
668 * kstat_irqs - Get the statistics for an interrupt
669 * @irq: The interrupt number
671 * Returns the sum of interrupt counts on all cpus since boot for
672 * @irq. The caller must ensure that the interrupt is not removed
675 unsigned int kstat_irqs(unsigned int irq)
677 struct irq_desc *desc = irq_to_desc(irq);
679 unsigned int sum = 0;
681 if (!desc || !desc->kstat_irqs)
683 for_each_possible_cpu(cpu)
684 sum += *per_cpu_ptr(desc->kstat_irqs, cpu);
689 * kstat_irqs_usr - Get the statistics for an interrupt
690 * @irq: The interrupt number
692 * Returns the sum of interrupt counts on all cpus since boot for
693 * @irq. Contrary to kstat_irqs() this can be called from any
694 * preemptible context. It's protected against concurrent removal of
695 * an interrupt descriptor when sparse irqs are enabled.
697 unsigned int kstat_irqs_usr(unsigned int irq)
702 sum = kstat_irqs(irq);