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 void __init init_irq_default_affinity(void)
29 alloc_cpumask_var(&irq_default_affinity, GFP_NOWAIT);
30 cpumask_setall(irq_default_affinity);
33 static void __init init_irq_default_affinity(void)
39 static int alloc_masks(struct irq_desc *desc, gfp_t gfp, int node)
41 if (!zalloc_cpumask_var_node(&desc->irq_common_data.affinity,
45 #ifdef CONFIG_GENERIC_PENDING_IRQ
46 if (!zalloc_cpumask_var_node(&desc->pending_mask, gfp, node)) {
47 free_cpumask_var(desc->irq_common_data.affinity);
54 static void desc_smp_init(struct irq_desc *desc, int node)
56 cpumask_copy(desc->irq_common_data.affinity, irq_default_affinity);
57 #ifdef CONFIG_GENERIC_PENDING_IRQ
58 cpumask_clear(desc->pending_mask);
61 desc->irq_common_data.node = node;
67 alloc_masks(struct irq_desc *desc, gfp_t gfp, int node) { return 0; }
68 static inline void desc_smp_init(struct irq_desc *desc, int node) { }
71 static void desc_set_defaults(unsigned int irq, struct irq_desc *desc, int node,
76 desc->irq_common_data.handler_data = NULL;
77 desc->irq_common_data.msi_desc = NULL;
79 desc->irq_data.common = &desc->irq_common_data;
80 desc->irq_data.irq = irq;
81 desc->irq_data.chip = &no_irq_chip;
82 desc->irq_data.chip_data = 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;
88 desc->irqs_unhandled = 0;
91 for_each_possible_cpu(cpu)
92 *per_cpu_ptr(desc->kstat_irqs, cpu) = 0;
93 desc_smp_init(desc, node);
96 int nr_irqs = NR_IRQS;
97 EXPORT_SYMBOL_GPL(nr_irqs);
99 static DEFINE_MUTEX(sparse_irq_lock);
100 static DECLARE_BITMAP(allocated_irqs, IRQ_BITMAP_BITS);
102 #ifdef CONFIG_SPARSE_IRQ
104 static RADIX_TREE(irq_desc_tree, GFP_KERNEL);
106 static void irq_insert_desc(unsigned int irq, struct irq_desc *desc)
108 radix_tree_insert(&irq_desc_tree, irq, desc);
111 struct irq_desc *irq_to_desc(unsigned int irq)
113 return radix_tree_lookup(&irq_desc_tree, irq);
115 EXPORT_SYMBOL(irq_to_desc);
117 static void delete_irq_desc(unsigned int irq)
119 radix_tree_delete(&irq_desc_tree, irq);
123 static void free_masks(struct irq_desc *desc)
125 #ifdef CONFIG_GENERIC_PENDING_IRQ
126 free_cpumask_var(desc->pending_mask);
128 free_cpumask_var(desc->irq_common_data.affinity);
131 static inline void free_masks(struct irq_desc *desc) { }
134 void irq_lock_sparse(void)
136 mutex_lock(&sparse_irq_lock);
139 void irq_unlock_sparse(void)
141 mutex_unlock(&sparse_irq_lock);
144 static struct irq_desc *alloc_desc(int irq, int node, struct module *owner)
146 struct irq_desc *desc;
147 gfp_t gfp = GFP_KERNEL;
149 desc = kzalloc_node(sizeof(*desc), gfp, node);
152 /* allocate based on nr_cpu_ids */
153 desc->kstat_irqs = alloc_percpu(unsigned int);
154 if (!desc->kstat_irqs)
157 if (alloc_masks(desc, gfp, node))
160 raw_spin_lock_init(&desc->lock);
161 lockdep_set_class(&desc->lock, &irq_desc_lock_class);
162 init_rcu_head(&desc->rcu);
164 desc_set_defaults(irq, desc, node, owner);
169 free_percpu(desc->kstat_irqs);
175 static void delayed_free_desc(struct rcu_head *rhp)
177 struct irq_desc *desc = container_of(rhp, struct irq_desc, rcu);
180 free_percpu(desc->kstat_irqs);
184 static void free_desc(unsigned int irq)
186 struct irq_desc *desc = irq_to_desc(irq);
188 unregister_irq_proc(irq, desc);
191 * sparse_irq_lock protects also show_interrupts() and
192 * kstat_irq_usr(). Once we deleted the descriptor from the
193 * sparse tree we can free it. Access in proc will fail to
194 * lookup the descriptor.
196 mutex_lock(&sparse_irq_lock);
197 delete_irq_desc(irq);
198 mutex_unlock(&sparse_irq_lock);
201 * We free the descriptor, masks and stat fields via RCU. That
202 * allows demultiplex interrupts to do rcu based management of
203 * the child interrupts.
205 call_rcu(&desc->rcu, delayed_free_desc);
208 static int alloc_descs(unsigned int start, unsigned int cnt, int node,
209 struct module *owner)
211 struct irq_desc *desc;
214 for (i = 0; i < cnt; i++) {
215 desc = alloc_desc(start + i, node, owner);
218 mutex_lock(&sparse_irq_lock);
219 irq_insert_desc(start + i, desc);
220 mutex_unlock(&sparse_irq_lock);
225 for (i--; i >= 0; i--)
226 free_desc(start + i);
228 mutex_lock(&sparse_irq_lock);
229 bitmap_clear(allocated_irqs, start, cnt);
230 mutex_unlock(&sparse_irq_lock);
234 static int irq_expand_nr_irqs(unsigned int nr)
236 if (nr > IRQ_BITMAP_BITS)
242 int __init early_irq_init(void)
244 int i, initcnt, node = first_online_node;
245 struct irq_desc *desc;
247 init_irq_default_affinity();
249 /* Let arch update nr_irqs and return the nr of preallocated irqs */
250 initcnt = arch_probe_nr_irqs();
251 printk(KERN_INFO "NR_IRQS:%d nr_irqs:%d %d\n", NR_IRQS, nr_irqs, initcnt);
253 if (WARN_ON(nr_irqs > IRQ_BITMAP_BITS))
254 nr_irqs = IRQ_BITMAP_BITS;
256 if (WARN_ON(initcnt > IRQ_BITMAP_BITS))
257 initcnt = IRQ_BITMAP_BITS;
259 if (initcnt > nr_irqs)
262 for (i = 0; i < initcnt; i++) {
263 desc = alloc_desc(i, node, NULL);
264 set_bit(i, allocated_irqs);
265 irq_insert_desc(i, desc);
267 return arch_early_irq_init();
270 #else /* !CONFIG_SPARSE_IRQ */
272 struct irq_desc irq_desc[NR_IRQS] __cacheline_aligned_in_smp = {
273 [0 ... NR_IRQS-1] = {
274 .handle_irq = handle_bad_irq,
276 .lock = __RAW_SPIN_LOCK_UNLOCKED(irq_desc->lock),
280 int __init early_irq_init(void)
282 int count, i, node = first_online_node;
283 struct irq_desc *desc;
285 init_irq_default_affinity();
287 printk(KERN_INFO "NR_IRQS:%d\n", NR_IRQS);
290 count = ARRAY_SIZE(irq_desc);
292 for (i = 0; i < count; i++) {
293 desc[i].kstat_irqs = alloc_percpu(unsigned int);
294 alloc_masks(&desc[i], GFP_KERNEL, node);
295 raw_spin_lock_init(&desc[i].lock);
296 lockdep_set_class(&desc[i].lock, &irq_desc_lock_class);
297 desc_set_defaults(i, &desc[i], node, NULL);
299 return arch_early_irq_init();
302 struct irq_desc *irq_to_desc(unsigned int irq)
304 return (irq < NR_IRQS) ? irq_desc + irq : NULL;
306 EXPORT_SYMBOL(irq_to_desc);
308 static void free_desc(unsigned int irq)
310 struct irq_desc *desc = irq_to_desc(irq);
313 raw_spin_lock_irqsave(&desc->lock, flags);
314 desc_set_defaults(irq, desc, irq_desc_get_node(desc), NULL);
315 raw_spin_unlock_irqrestore(&desc->lock, flags);
318 static inline int alloc_descs(unsigned int start, unsigned int cnt, int node,
319 struct module *owner)
323 for (i = 0; i < cnt; i++) {
324 struct irq_desc *desc = irq_to_desc(start + i);
331 static int irq_expand_nr_irqs(unsigned int nr)
336 void irq_mark_irq(unsigned int irq)
338 mutex_lock(&sparse_irq_lock);
339 bitmap_set(allocated_irqs, irq, 1);
340 mutex_unlock(&sparse_irq_lock);
343 #ifdef CONFIG_GENERIC_IRQ_LEGACY
344 void irq_init_desc(unsigned int irq)
350 #endif /* !CONFIG_SPARSE_IRQ */
353 * generic_handle_irq - Invoke the handler for a particular irq
354 * @irq: The irq number to handle
357 int generic_handle_irq(unsigned int irq)
359 struct irq_desc *desc = irq_to_desc(irq);
363 generic_handle_irq_desc(desc);
366 EXPORT_SYMBOL_GPL(generic_handle_irq);
368 #ifdef CONFIG_HANDLE_DOMAIN_IRQ
370 * __handle_domain_irq - Invoke the handler for a HW irq belonging to a domain
371 * @domain: The domain where to perform the lookup
372 * @hwirq: The HW irq number to convert to a logical one
373 * @lookup: Whether to perform the domain lookup or not
374 * @regs: Register file coming from the low-level handling code
376 * Returns: 0 on success, or -EINVAL if conversion has failed
378 int __handle_domain_irq(struct irq_domain *domain, unsigned int hwirq,
379 bool lookup, struct pt_regs *regs)
381 struct pt_regs *old_regs = set_irq_regs(regs);
382 unsigned int irq = hwirq;
387 #ifdef CONFIG_IRQ_DOMAIN
389 irq = irq_find_mapping(domain, hwirq);
393 * Some hardware gives randomly wrong interrupts. Rather
394 * than crashing, do something sensible.
396 if (unlikely(!irq || irq >= nr_irqs)) {
400 generic_handle_irq(irq);
404 set_irq_regs(old_regs);
409 /* Dynamic interrupt handling */
412 * irq_free_descs - free irq descriptors
413 * @from: Start of descriptor range
414 * @cnt: Number of consecutive irqs to free
416 void irq_free_descs(unsigned int from, unsigned int cnt)
420 if (from >= nr_irqs || (from + cnt) > nr_irqs)
423 for (i = 0; i < cnt; i++)
426 mutex_lock(&sparse_irq_lock);
427 bitmap_clear(allocated_irqs, from, cnt);
428 mutex_unlock(&sparse_irq_lock);
430 EXPORT_SYMBOL_GPL(irq_free_descs);
433 * irq_alloc_descs - allocate and initialize a range of irq descriptors
434 * @irq: Allocate for specific irq number if irq >= 0
435 * @from: Start the search from this irq number
436 * @cnt: Number of consecutive irqs to allocate.
437 * @node: Preferred node on which the irq descriptor should be allocated
438 * @owner: Owning module (can be NULL)
440 * Returns the first irq number or error code
443 __irq_alloc_descs(int irq, unsigned int from, unsigned int cnt, int node,
444 struct module *owner)
457 * For interrupts which are freely allocated the
458 * architecture can force a lower bound to the @from
459 * argument. x86 uses this to exclude the GSI space.
461 from = arch_dynirq_lower_bound(from);
464 mutex_lock(&sparse_irq_lock);
466 start = bitmap_find_next_zero_area(allocated_irqs, IRQ_BITMAP_BITS,
469 if (irq >=0 && start != irq)
472 if (start + cnt > nr_irqs) {
473 ret = irq_expand_nr_irqs(start + cnt);
478 bitmap_set(allocated_irqs, start, cnt);
479 mutex_unlock(&sparse_irq_lock);
480 return alloc_descs(start, cnt, node, owner);
483 mutex_unlock(&sparse_irq_lock);
486 EXPORT_SYMBOL_GPL(__irq_alloc_descs);
488 #ifdef CONFIG_GENERIC_IRQ_LEGACY_ALLOC_HWIRQ
490 * irq_alloc_hwirqs - Allocate an irq descriptor and initialize the hardware
491 * @cnt: number of interrupts to allocate
492 * @node: node on which to allocate
494 * Returns an interrupt number > 0 or 0, if the allocation fails.
496 unsigned int irq_alloc_hwirqs(int cnt, int node)
498 int i, irq = __irq_alloc_descs(-1, 0, cnt, node, NULL);
503 for (i = irq; cnt > 0; i++, cnt--) {
504 if (arch_setup_hwirq(i, node))
506 irq_clear_status_flags(i, _IRQ_NOREQUEST);
511 for (i--; i >= irq; i--) {
512 irq_set_status_flags(i, _IRQ_NOREQUEST | _IRQ_NOPROBE);
513 arch_teardown_hwirq(i);
515 irq_free_descs(irq, cnt);
518 EXPORT_SYMBOL_GPL(irq_alloc_hwirqs);
521 * irq_free_hwirqs - Free irq descriptor and cleanup the hardware
522 * @from: Free from irq number
523 * @cnt: number of interrupts to free
526 void irq_free_hwirqs(unsigned int from, int cnt)
530 for (i = from, j = cnt; j > 0; i++, j--) {
531 irq_set_status_flags(i, _IRQ_NOREQUEST | _IRQ_NOPROBE);
532 arch_teardown_hwirq(i);
534 irq_free_descs(from, cnt);
536 EXPORT_SYMBOL_GPL(irq_free_hwirqs);
540 * irq_get_next_irq - get next allocated irq number
541 * @offset: where to start the search
543 * Returns next irq number after offset or nr_irqs if none is found.
545 unsigned int irq_get_next_irq(unsigned int offset)
547 return find_next_bit(allocated_irqs, nr_irqs, offset);
551 __irq_get_desc_lock(unsigned int irq, unsigned long *flags, bool bus,
554 struct irq_desc *desc = irq_to_desc(irq);
557 if (check & _IRQ_DESC_CHECK) {
558 if ((check & _IRQ_DESC_PERCPU) &&
559 !irq_settings_is_per_cpu_devid(desc))
562 if (!(check & _IRQ_DESC_PERCPU) &&
563 irq_settings_is_per_cpu_devid(desc))
569 raw_spin_lock_irqsave(&desc->lock, *flags);
574 void __irq_put_desc_unlock(struct irq_desc *desc, unsigned long flags, bool bus)
576 raw_spin_unlock_irqrestore(&desc->lock, flags);
578 chip_bus_sync_unlock(desc);
581 int irq_set_percpu_devid(unsigned int irq)
583 struct irq_desc *desc = irq_to_desc(irq);
588 if (desc->percpu_enabled)
591 desc->percpu_enabled = kzalloc(sizeof(*desc->percpu_enabled), GFP_KERNEL);
593 if (!desc->percpu_enabled)
596 irq_set_percpu_devid_flags(irq);
600 void kstat_incr_irq_this_cpu(unsigned int irq)
602 kstat_incr_irqs_this_cpu(irq_to_desc(irq));
606 * kstat_irqs_cpu - Get the statistics for an interrupt on a cpu
607 * @irq: The interrupt number
608 * @cpu: The cpu number
610 * Returns the sum of interrupt counts on @cpu since boot for
611 * @irq. The caller must ensure that the interrupt is not removed
614 unsigned int kstat_irqs_cpu(unsigned int irq, int cpu)
616 struct irq_desc *desc = irq_to_desc(irq);
618 return desc && desc->kstat_irqs ?
619 *per_cpu_ptr(desc->kstat_irqs, cpu) : 0;
623 * kstat_irqs - Get the statistics for an interrupt
624 * @irq: The interrupt number
626 * Returns the sum of interrupt counts on all cpus since boot for
627 * @irq. The caller must ensure that the interrupt is not removed
630 unsigned int kstat_irqs(unsigned int irq)
632 struct irq_desc *desc = irq_to_desc(irq);
634 unsigned int sum = 0;
636 if (!desc || !desc->kstat_irqs)
638 for_each_possible_cpu(cpu)
639 sum += *per_cpu_ptr(desc->kstat_irqs, cpu);
644 * kstat_irqs_usr - Get the statistics for an interrupt
645 * @irq: The interrupt number
647 * Returns the sum of interrupt counts on all cpus since boot for
648 * @irq. Contrary to kstat_irqs() this can be called from any
649 * preemptible context. It's protected against concurrent removal of
650 * an interrupt descriptor when sparse irqs are enabled.
652 unsigned int kstat_irqs_usr(unsigned int irq)
657 sum = kstat_irqs(irq);