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);
180 desc_set_defaults(irq, desc, node, owner);
185 free_percpu(desc->kstat_irqs);
191 static void free_desc(unsigned int irq)
193 struct irq_desc *desc = irq_to_desc(irq);
195 unregister_irq_proc(irq, desc);
198 * sparse_irq_lock protects also show_interrupts() and
199 * kstat_irq_usr(). Once we deleted the descriptor from the
200 * sparse tree we can free it. Access in proc will fail to
201 * lookup the descriptor.
203 mutex_lock(&sparse_irq_lock);
204 delete_irq_desc(irq);
205 mutex_unlock(&sparse_irq_lock);
208 free_percpu(desc->kstat_irqs);
212 static int alloc_descs(unsigned int start, unsigned int cnt, int node,
213 struct module *owner)
215 struct irq_desc *desc;
218 for (i = 0; i < cnt; i++) {
219 desc = alloc_desc(start + i, node, owner);
222 mutex_lock(&sparse_irq_lock);
223 irq_insert_desc(start + i, desc);
224 mutex_unlock(&sparse_irq_lock);
229 for (i--; i >= 0; i--)
230 free_desc(start + i);
232 mutex_lock(&sparse_irq_lock);
233 bitmap_clear(allocated_irqs, start, cnt);
234 mutex_unlock(&sparse_irq_lock);
238 static int irq_expand_nr_irqs(unsigned int nr)
240 if (nr > IRQ_BITMAP_BITS)
246 int __init early_irq_init(void)
248 int i, initcnt, node = first_online_node;
249 struct irq_desc *desc;
251 init_irq_default_affinity();
253 /* Let arch update nr_irqs and return the nr of preallocated irqs */
254 initcnt = arch_probe_nr_irqs();
255 printk(KERN_INFO "NR_IRQS:%d nr_irqs:%d %d\n", NR_IRQS, nr_irqs, initcnt);
257 if (WARN_ON(nr_irqs > IRQ_BITMAP_BITS))
258 nr_irqs = IRQ_BITMAP_BITS;
260 if (WARN_ON(initcnt > IRQ_BITMAP_BITS))
261 initcnt = IRQ_BITMAP_BITS;
263 if (initcnt > nr_irqs)
266 for (i = 0; i < initcnt; i++) {
267 desc = alloc_desc(i, node, NULL);
268 set_bit(i, allocated_irqs);
269 irq_insert_desc(i, desc);
271 return arch_early_irq_init();
274 #else /* !CONFIG_SPARSE_IRQ */
276 struct irq_desc irq_desc[NR_IRQS] __cacheline_aligned_in_smp = {
277 [0 ... NR_IRQS-1] = {
278 .handle_irq = handle_bad_irq,
280 .lock = __RAW_SPIN_LOCK_UNLOCKED(irq_desc->lock),
284 int __init early_irq_init(void)
286 int count, i, node = first_online_node;
287 struct irq_desc *desc;
289 init_irq_default_affinity();
291 printk(KERN_INFO "NR_IRQS:%d\n", NR_IRQS);
294 count = ARRAY_SIZE(irq_desc);
296 for (i = 0; i < count; i++) {
297 desc[i].kstat_irqs = alloc_percpu(unsigned int);
298 alloc_masks(&desc[i], GFP_KERNEL, node);
299 raw_spin_lock_init(&desc[i].lock);
300 lockdep_set_class(&desc[i].lock, &irq_desc_lock_class);
301 desc_set_defaults(i, &desc[i], node, NULL);
303 return arch_early_irq_init();
306 struct irq_desc *irq_to_desc(unsigned int irq)
308 return (irq < NR_IRQS) ? irq_desc + irq : NULL;
310 EXPORT_SYMBOL(irq_to_desc);
312 static void free_desc(unsigned int irq)
314 struct irq_desc *desc = irq_to_desc(irq);
317 raw_spin_lock_irqsave(&desc->lock, flags);
318 desc_set_defaults(irq, desc, irq_desc_get_node(desc), NULL);
319 raw_spin_unlock_irqrestore(&desc->lock, flags);
322 static inline int alloc_descs(unsigned int start, unsigned int cnt, int node,
323 struct module *owner)
327 for (i = 0; i < cnt; i++) {
328 struct irq_desc *desc = irq_to_desc(start + i);
335 static int irq_expand_nr_irqs(unsigned int nr)
340 void irq_mark_irq(unsigned int irq)
342 mutex_lock(&sparse_irq_lock);
343 bitmap_set(allocated_irqs, irq, 1);
344 mutex_unlock(&sparse_irq_lock);
347 #ifdef CONFIG_GENERIC_IRQ_LEGACY
348 void irq_init_desc(unsigned int irq)
354 #endif /* !CONFIG_SPARSE_IRQ */
357 * generic_handle_irq - Invoke the handler for a particular irq
358 * @irq: The irq number to handle
361 int generic_handle_irq(unsigned int irq)
363 struct irq_desc *desc = irq_to_desc(irq);
367 generic_handle_irq_desc(desc);
370 EXPORT_SYMBOL_GPL(generic_handle_irq);
372 #ifdef CONFIG_HANDLE_DOMAIN_IRQ
374 * __handle_domain_irq - Invoke the handler for a HW irq belonging to a domain
375 * @domain: The domain where to perform the lookup
376 * @hwirq: The HW irq number to convert to a logical one
377 * @lookup: Whether to perform the domain lookup or not
378 * @regs: Register file coming from the low-level handling code
380 * Returns: 0 on success, or -EINVAL if conversion has failed
382 int __handle_domain_irq(struct irq_domain *domain, unsigned int hwirq,
383 bool lookup, struct pt_regs *regs)
385 struct pt_regs *old_regs = set_irq_regs(regs);
386 unsigned int irq = hwirq;
391 #ifdef CONFIG_IRQ_DOMAIN
393 irq = irq_find_mapping(domain, hwirq);
397 * Some hardware gives randomly wrong interrupts. Rather
398 * than crashing, do something sensible.
400 if (unlikely(!irq || irq >= nr_irqs)) {
404 generic_handle_irq(irq);
408 set_irq_regs(old_regs);
413 /* Dynamic interrupt handling */
416 * irq_free_descs - free irq descriptors
417 * @from: Start of descriptor range
418 * @cnt: Number of consecutive irqs to free
420 void irq_free_descs(unsigned int from, unsigned int cnt)
424 if (from >= nr_irqs || (from + cnt) > nr_irqs)
427 for (i = 0; i < cnt; i++)
430 mutex_lock(&sparse_irq_lock);
431 bitmap_clear(allocated_irqs, from, cnt);
432 mutex_unlock(&sparse_irq_lock);
434 EXPORT_SYMBOL_GPL(irq_free_descs);
437 * irq_alloc_descs - allocate and initialize a range of irq descriptors
438 * @irq: Allocate for specific irq number if irq >= 0
439 * @from: Start the search from this irq number
440 * @cnt: Number of consecutive irqs to allocate.
441 * @node: Preferred node on which the irq descriptor should be allocated
442 * @owner: Owning module (can be NULL)
444 * Returns the first irq number or error code
447 __irq_alloc_descs(int irq, unsigned int from, unsigned int cnt, int node,
448 struct module *owner)
461 * For interrupts which are freely allocated the
462 * architecture can force a lower bound to the @from
463 * argument. x86 uses this to exclude the GSI space.
465 from = arch_dynirq_lower_bound(from);
468 mutex_lock(&sparse_irq_lock);
470 start = bitmap_find_next_zero_area(allocated_irqs, IRQ_BITMAP_BITS,
473 if (irq >=0 && start != irq)
476 if (start + cnt > nr_irqs) {
477 ret = irq_expand_nr_irqs(start + cnt);
482 bitmap_set(allocated_irqs, start, cnt);
483 mutex_unlock(&sparse_irq_lock);
484 return alloc_descs(start, cnt, node, owner);
487 mutex_unlock(&sparse_irq_lock);
490 EXPORT_SYMBOL_GPL(__irq_alloc_descs);
492 #ifdef CONFIG_GENERIC_IRQ_LEGACY_ALLOC_HWIRQ
494 * irq_alloc_hwirqs - Allocate an irq descriptor and initialize the hardware
495 * @cnt: number of interrupts to allocate
496 * @node: node on which to allocate
498 * Returns an interrupt number > 0 or 0, if the allocation fails.
500 unsigned int irq_alloc_hwirqs(int cnt, int node)
502 int i, irq = __irq_alloc_descs(-1, 0, cnt, node, NULL);
507 for (i = irq; cnt > 0; i++, cnt--) {
508 if (arch_setup_hwirq(i, node))
510 irq_clear_status_flags(i, _IRQ_NOREQUEST);
515 for (i--; i >= irq; i--) {
516 irq_set_status_flags(i, _IRQ_NOREQUEST | _IRQ_NOPROBE);
517 arch_teardown_hwirq(i);
519 irq_free_descs(irq, cnt);
522 EXPORT_SYMBOL_GPL(irq_alloc_hwirqs);
525 * irq_free_hwirqs - Free irq descriptor and cleanup the hardware
526 * @from: Free from irq number
527 * @cnt: number of interrupts to free
530 void irq_free_hwirqs(unsigned int from, int cnt)
534 for (i = from, j = cnt; j > 0; i++, j--) {
535 irq_set_status_flags(i, _IRQ_NOREQUEST | _IRQ_NOPROBE);
536 arch_teardown_hwirq(i);
538 irq_free_descs(from, cnt);
540 EXPORT_SYMBOL_GPL(irq_free_hwirqs);
544 * irq_get_next_irq - get next allocated irq number
545 * @offset: where to start the search
547 * Returns next irq number after offset or nr_irqs if none is found.
549 unsigned int irq_get_next_irq(unsigned int offset)
551 return find_next_bit(allocated_irqs, nr_irqs, offset);
555 __irq_get_desc_lock(unsigned int irq, unsigned long *flags, bool bus,
558 struct irq_desc *desc = irq_to_desc(irq);
561 if (check & _IRQ_DESC_CHECK) {
562 if ((check & _IRQ_DESC_PERCPU) &&
563 !irq_settings_is_per_cpu_devid(desc))
566 if (!(check & _IRQ_DESC_PERCPU) &&
567 irq_settings_is_per_cpu_devid(desc))
573 raw_spin_lock_irqsave(&desc->lock, *flags);
578 void __irq_put_desc_unlock(struct irq_desc *desc, unsigned long flags, bool bus)
580 raw_spin_unlock_irqrestore(&desc->lock, flags);
582 chip_bus_sync_unlock(desc);
585 int irq_set_percpu_devid(unsigned int irq)
587 struct irq_desc *desc = irq_to_desc(irq);
592 if (desc->percpu_enabled)
595 desc->percpu_enabled = kzalloc(sizeof(*desc->percpu_enabled), GFP_KERNEL);
597 if (!desc->percpu_enabled)
600 irq_set_percpu_devid_flags(irq);
604 void kstat_incr_irq_this_cpu(unsigned int irq)
606 kstat_incr_irqs_this_cpu(irq_to_desc(irq));
610 * kstat_irqs_cpu - Get the statistics for an interrupt on a cpu
611 * @irq: The interrupt number
612 * @cpu: The cpu number
614 * Returns the sum of interrupt counts on @cpu since boot for
615 * @irq. The caller must ensure that the interrupt is not removed
618 unsigned int kstat_irqs_cpu(unsigned int irq, int cpu)
620 struct irq_desc *desc = irq_to_desc(irq);
622 return desc && desc->kstat_irqs ?
623 *per_cpu_ptr(desc->kstat_irqs, cpu) : 0;
627 * kstat_irqs - Get the statistics for an interrupt
628 * @irq: The interrupt number
630 * Returns the sum of interrupt counts on all cpus since boot for
631 * @irq. The caller must ensure that the interrupt is not removed
634 unsigned int kstat_irqs(unsigned int irq)
636 struct irq_desc *desc = irq_to_desc(irq);
638 unsigned int sum = 0;
640 if (!desc || !desc->kstat_irqs)
642 for_each_possible_cpu(cpu)
643 sum += *per_cpu_ptr(desc->kstat_irqs, cpu);
648 * kstat_irqs_usr - Get the statistics for an interrupt
649 * @irq: The interrupt number
651 * Returns the sum of interrupt counts on all cpus since boot for
652 * @irq. Contrary to kstat_irqs() this can be called from any
653 * preemptible context. It's protected against concurrent removal of
654 * an interrupt descriptor when sparse irqs are enabled.
656 unsigned int kstat_irqs_usr(unsigned int irq)
661 sum = kstat_irqs(irq);