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>
18 #include "internals.h"
21 * lockdep: we want to handle all irq_desc locks as a single lock-class:
23 static struct lock_class_key irq_desc_lock_class;
25 #if defined(CONFIG_SMP)
26 static void __init init_irq_default_affinity(void)
28 alloc_cpumask_var(&irq_default_affinity, GFP_NOWAIT);
29 cpumask_setall(irq_default_affinity);
32 static void __init init_irq_default_affinity(void)
38 static int alloc_masks(struct irq_desc *desc, gfp_t gfp, int node)
40 if (!zalloc_cpumask_var_node(&desc->irq_data.affinity, gfp, node))
43 #ifdef CONFIG_GENERIC_PENDING_IRQ
44 if (!zalloc_cpumask_var_node(&desc->pending_mask, gfp, node)) {
45 free_cpumask_var(desc->irq_data.affinity);
52 static void desc_smp_init(struct irq_desc *desc, int node)
54 desc->irq_data.node = node;
55 cpumask_copy(desc->irq_data.affinity, irq_default_affinity);
56 #ifdef CONFIG_GENERIC_PENDING_IRQ
57 cpumask_clear(desc->pending_mask);
61 static inline int desc_node(struct irq_desc *desc)
63 return desc->irq_data.node;
68 alloc_masks(struct irq_desc *desc, gfp_t gfp, int node) { return 0; }
69 static inline void desc_smp_init(struct irq_desc *desc, int node) { }
70 static inline int desc_node(struct irq_desc *desc) { return 0; }
73 static void desc_set_defaults(unsigned int irq, struct irq_desc *desc, int node,
78 desc->irq_data.irq = irq;
79 desc->irq_data.chip = &no_irq_chip;
80 desc->irq_data.chip_data = NULL;
81 desc->irq_data.handler_data = NULL;
82 desc->irq_data.msi_desc = 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);
116 static void delete_irq_desc(unsigned int irq)
118 radix_tree_delete(&irq_desc_tree, irq);
122 static void free_masks(struct irq_desc *desc)
124 #ifdef CONFIG_GENERIC_PENDING_IRQ
125 free_cpumask_var(desc->pending_mask);
127 free_cpumask_var(desc->irq_data.affinity);
130 static inline void free_masks(struct irq_desc *desc) { }
133 void irq_lock_sparse(void)
135 mutex_lock(&sparse_irq_lock);
138 void irq_unlock_sparse(void)
140 mutex_unlock(&sparse_irq_lock);
143 static struct irq_desc *alloc_desc(int irq, int node, struct module *owner)
145 struct irq_desc *desc;
146 gfp_t gfp = GFP_KERNEL;
148 desc = kzalloc_node(sizeof(*desc), gfp, node);
151 /* allocate based on nr_cpu_ids */
152 desc->kstat_irqs = alloc_percpu(unsigned int);
153 if (!desc->kstat_irqs)
156 if (alloc_masks(desc, gfp, node))
159 raw_spin_lock_init(&desc->lock);
160 lockdep_set_class(&desc->lock, &irq_desc_lock_class);
162 desc_set_defaults(irq, desc, node, owner);
167 free_percpu(desc->kstat_irqs);
173 static void free_desc(unsigned int irq)
175 struct irq_desc *desc = irq_to_desc(irq);
177 unregister_irq_proc(irq, desc);
180 * sparse_irq_lock protects also show_interrupts() and
181 * kstat_irq_usr(). Once we deleted the descriptor from the
182 * sparse tree we can free it. Access in proc will fail to
183 * lookup the descriptor.
185 delete_irq_desc(irq);
188 free_percpu(desc->kstat_irqs);
192 static int alloc_descs(unsigned int start, unsigned int cnt, int node,
193 struct module *owner)
195 struct irq_desc *desc;
198 for (i = 0; i < cnt; i++) {
199 desc = alloc_desc(start + i, node, owner);
202 irq_insert_desc(start + i, desc);
204 bitmap_set(allocated_irqs, start, cnt);
208 for (i--; i >= 0; i--)
209 free_desc(start + i);
213 static int irq_expand_nr_irqs(unsigned int nr)
215 if (nr > IRQ_BITMAP_BITS)
221 int __init early_irq_init(void)
223 int i, initcnt, node = first_online_node;
224 struct irq_desc *desc;
226 init_irq_default_affinity();
228 /* Let arch update nr_irqs and return the nr of preallocated irqs */
229 initcnt = arch_probe_nr_irqs();
230 printk(KERN_INFO "NR_IRQS:%d nr_irqs:%d %d\n", NR_IRQS, nr_irqs, initcnt);
232 if (WARN_ON(nr_irqs > IRQ_BITMAP_BITS))
233 nr_irqs = IRQ_BITMAP_BITS;
235 if (WARN_ON(initcnt > IRQ_BITMAP_BITS))
236 initcnt = IRQ_BITMAP_BITS;
238 if (initcnt > nr_irqs)
241 for (i = 0; i < initcnt; i++) {
242 desc = alloc_desc(i, node, NULL);
243 set_bit(i, allocated_irqs);
244 irq_insert_desc(i, desc);
246 return arch_early_irq_init();
249 #else /* !CONFIG_SPARSE_IRQ */
251 struct irq_desc irq_desc[NR_IRQS] __cacheline_aligned_in_smp = {
252 [0 ... NR_IRQS-1] = {
253 .handle_irq = handle_bad_irq,
255 .lock = __RAW_SPIN_LOCK_UNLOCKED(irq_desc->lock),
259 int __init early_irq_init(void)
261 int count, i, node = first_online_node;
262 struct irq_desc *desc;
264 init_irq_default_affinity();
266 printk(KERN_INFO "NR_IRQS:%d\n", NR_IRQS);
269 count = ARRAY_SIZE(irq_desc);
271 for (i = 0; i < count; i++) {
272 desc[i].kstat_irqs = alloc_percpu(unsigned int);
273 alloc_masks(&desc[i], GFP_KERNEL, node);
274 raw_spin_lock_init(&desc[i].lock);
275 lockdep_set_class(&desc[i].lock, &irq_desc_lock_class);
276 desc_set_defaults(i, &desc[i], node, NULL);
278 return arch_early_irq_init();
281 struct irq_desc *irq_to_desc(unsigned int irq)
283 return (irq < NR_IRQS) ? irq_desc + irq : NULL;
286 static void free_desc(unsigned int irq)
288 dynamic_irq_cleanup(irq);
291 static inline int alloc_descs(unsigned int start, unsigned int cnt, int node,
292 struct module *owner)
296 for (i = 0; i < cnt; i++) {
297 struct irq_desc *desc = irq_to_desc(start + i);
301 bitmap_set(allocated_irqs, start, cnt);
305 static int irq_expand_nr_irqs(unsigned int nr)
310 #endif /* !CONFIG_SPARSE_IRQ */
313 * generic_handle_irq - Invoke the handler for a particular irq
314 * @irq: The irq number to handle
317 int generic_handle_irq(unsigned int irq)
319 struct irq_desc *desc = irq_to_desc(irq);
323 generic_handle_irq_desc(irq, desc);
326 EXPORT_SYMBOL_GPL(generic_handle_irq);
328 /* Dynamic interrupt handling */
331 * irq_free_descs - free irq descriptors
332 * @from: Start of descriptor range
333 * @cnt: Number of consecutive irqs to free
335 void irq_free_descs(unsigned int from, unsigned int cnt)
339 if (from >= nr_irqs || (from + cnt) > nr_irqs)
342 mutex_lock(&sparse_irq_lock);
343 for (i = 0; i < cnt; i++)
346 bitmap_clear(allocated_irqs, from, cnt);
347 mutex_unlock(&sparse_irq_lock);
349 EXPORT_SYMBOL_GPL(irq_free_descs);
352 * irq_alloc_descs - allocate and initialize a range of irq descriptors
353 * @irq: Allocate for specific irq number if irq >= 0
354 * @from: Start the search from this irq number
355 * @cnt: Number of consecutive irqs to allocate.
356 * @node: Preferred node on which the irq descriptor should be allocated
357 * @owner: Owning module (can be NULL)
359 * Returns the first irq number or error code
362 __irq_alloc_descs(int irq, unsigned int from, unsigned int cnt, int node,
363 struct module *owner)
376 mutex_lock(&sparse_irq_lock);
378 start = bitmap_find_next_zero_area(allocated_irqs, IRQ_BITMAP_BITS,
381 if (irq >=0 && start != irq)
384 if (start + cnt > nr_irqs) {
385 ret = irq_expand_nr_irqs(start + cnt);
389 ret = alloc_descs(start, cnt, node, owner);
391 mutex_unlock(&sparse_irq_lock);
394 EXPORT_SYMBOL_GPL(__irq_alloc_descs);
397 * irq_reserve_irqs - mark irqs allocated
398 * @from: mark from irq number
399 * @cnt: number of irqs to mark
401 * Returns 0 on success or an appropriate error code
403 int irq_reserve_irqs(unsigned int from, unsigned int cnt)
408 if (!cnt || (from + cnt) > nr_irqs)
411 mutex_lock(&sparse_irq_lock);
412 start = bitmap_find_next_zero_area(allocated_irqs, nr_irqs, from, cnt, 0);
414 bitmap_set(allocated_irqs, start, cnt);
417 mutex_unlock(&sparse_irq_lock);
422 * irq_get_next_irq - get next allocated irq number
423 * @offset: where to start the search
425 * Returns next irq number after offset or nr_irqs if none is found.
427 unsigned int irq_get_next_irq(unsigned int offset)
429 return find_next_bit(allocated_irqs, nr_irqs, offset);
433 __irq_get_desc_lock(unsigned int irq, unsigned long *flags, bool bus,
436 struct irq_desc *desc = irq_to_desc(irq);
439 if (check & _IRQ_DESC_CHECK) {
440 if ((check & _IRQ_DESC_PERCPU) &&
441 !irq_settings_is_per_cpu_devid(desc))
444 if (!(check & _IRQ_DESC_PERCPU) &&
445 irq_settings_is_per_cpu_devid(desc))
451 raw_spin_lock_irqsave(&desc->lock, *flags);
456 void __irq_put_desc_unlock(struct irq_desc *desc, unsigned long flags, bool bus)
458 raw_spin_unlock_irqrestore(&desc->lock, flags);
460 chip_bus_sync_unlock(desc);
463 int irq_set_percpu_devid(unsigned int irq)
465 struct irq_desc *desc = irq_to_desc(irq);
470 if (desc->percpu_enabled)
473 desc->percpu_enabled = kzalloc(sizeof(*desc->percpu_enabled), GFP_KERNEL);
475 if (!desc->percpu_enabled)
478 irq_set_percpu_devid_flags(irq);
483 * dynamic_irq_cleanup - cleanup a dynamically allocated irq
484 * @irq: irq number to initialize
486 void dynamic_irq_cleanup(unsigned int irq)
488 struct irq_desc *desc = irq_to_desc(irq);
491 raw_spin_lock_irqsave(&desc->lock, flags);
492 desc_set_defaults(irq, desc, desc_node(desc), NULL);
493 raw_spin_unlock_irqrestore(&desc->lock, flags);
497 * kstat_irqs_cpu - Get the statistics for an interrupt on a cpu
498 * @irq: The interrupt number
499 * @cpu: The cpu number
501 * Returns the sum of interrupt counts on @cpu since boot for
502 * @irq. The caller must ensure that the interrupt is not removed
505 unsigned int kstat_irqs_cpu(unsigned int irq, int cpu)
507 struct irq_desc *desc = irq_to_desc(irq);
509 return desc && desc->kstat_irqs ?
510 *per_cpu_ptr(desc->kstat_irqs, cpu) : 0;
514 * kstat_irqs - Get the statistics for an interrupt
515 * @irq: The interrupt number
517 * Returns the sum of interrupt counts on all cpus since boot for
518 * @irq. The caller must ensure that the interrupt is not removed
521 unsigned int kstat_irqs(unsigned int irq)
523 struct irq_desc *desc = irq_to_desc(irq);
527 if (!desc || !desc->kstat_irqs)
529 for_each_possible_cpu(cpu)
530 sum += *per_cpu_ptr(desc->kstat_irqs, cpu);
535 * kstat_irqs_usr - Get the statistics for an interrupt
536 * @irq: The interrupt number
538 * Returns the sum of interrupt counts on all cpus since boot for
539 * @irq. Contrary to kstat_irqs() this can be called from any
540 * preemptible context. It's protected against concurrent removal of
541 * an interrupt descriptor when sparse irqs are enabled.
543 unsigned int kstat_irqs_usr(unsigned int irq)
548 sum = kstat_irqs(irq);