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/module.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 struct lock_class_key irq_desc_lock_class;
25 #if defined(CONFIG_SMP) && defined(CONFIG_GENERIC_HARDIRQS)
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)
75 desc->irq_data.irq = irq;
76 desc->irq_data.chip = &no_irq_chip;
77 desc->irq_data.chip_data = NULL;
78 desc->irq_data.handler_data = NULL;
79 desc->irq_data.msi_desc = NULL;
80 desc->status = IRQ_DEFAULT_INIT_FLAGS;
81 desc->handle_irq = handle_bad_irq;
84 desc->irqs_unhandled = 0;
86 memset(desc->kstat_irqs, 0, nr_cpu_ids * sizeof(*(desc->kstat_irqs)));
87 desc_smp_init(desc, node);
90 int nr_irqs = NR_IRQS;
91 EXPORT_SYMBOL_GPL(nr_irqs);
93 DEFINE_RAW_SPINLOCK(sparse_irq_lock);
94 static DECLARE_BITMAP(allocated_irqs, NR_IRQS);
96 #ifdef CONFIG_SPARSE_IRQ
98 void __ref init_kstat_irqs(struct irq_desc *desc, int node, int nr)
102 ptr = kzalloc_node(nr * sizeof(*desc->kstat_irqs),
106 * don't overwite if can not get new one
107 * init_copy_kstat_irqs() could still use old one
110 printk(KERN_DEBUG " alloc kstat_irqs on node %d\n", node);
111 desc->kstat_irqs = ptr;
115 static RADIX_TREE(irq_desc_tree, GFP_ATOMIC);
117 static void irq_insert_desc(unsigned int irq, struct irq_desc *desc)
119 radix_tree_insert(&irq_desc_tree, irq, desc);
122 struct irq_desc *irq_to_desc(unsigned int irq)
124 return radix_tree_lookup(&irq_desc_tree, irq);
127 void replace_irq_desc(unsigned int irq, struct irq_desc *desc)
131 ptr = radix_tree_lookup_slot(&irq_desc_tree, irq);
133 radix_tree_replace_slot(ptr, desc);
136 static void delete_irq_desc(unsigned int irq)
138 radix_tree_delete(&irq_desc_tree, irq);
142 static void free_masks(struct irq_desc *desc)
144 #ifdef CONFIG_GENERIC_PENDING_IRQ
145 free_cpumask_var(desc->pending_mask);
147 free_cpumask_var(desc->affinity);
150 static inline void free_masks(struct irq_desc *desc) { }
153 static struct irq_desc *alloc_desc(int irq, int node)
155 /* Temporary hack until we can switch to GFP_KERNEL */
156 gfp_t gfp = gfp_allowed_mask == GFP_BOOT_MASK ? GFP_NOWAIT : GFP_ATOMIC;
157 struct irq_desc *desc;
159 desc = kzalloc_node(sizeof(*desc), gfp, node);
162 /* allocate based on nr_cpu_ids */
163 desc->kstat_irqs = kzalloc_node(nr_cpu_ids * sizeof(*desc->kstat_irqs),
165 if (!desc->kstat_irqs)
168 if (alloc_masks(desc, gfp, node))
171 raw_spin_lock_init(&desc->lock);
172 lockdep_set_class(&desc->lock, &irq_desc_lock_class);
174 desc_set_defaults(irq, desc, node);
179 kfree(desc->kstat_irqs);
185 static void free_desc(unsigned int irq)
187 struct irq_desc *desc = irq_to_desc(irq);
190 unregister_irq_proc(irq, desc);
192 raw_spin_lock_irqsave(&sparse_irq_lock, flags);
193 delete_irq_desc(irq);
194 raw_spin_unlock_irqrestore(&sparse_irq_lock, flags);
197 kfree(desc->kstat_irqs);
201 static int alloc_descs(unsigned int start, unsigned int cnt, int node)
203 struct irq_desc *desc;
207 for (i = 0; i < cnt; i++) {
208 desc = alloc_desc(start + i, node);
211 raw_spin_lock_irqsave(&sparse_irq_lock, flags);
212 irq_insert_desc(start + i, desc);
213 raw_spin_unlock_irqrestore(&sparse_irq_lock, flags);
218 for (i--; i >= 0; i--)
219 free_desc(start + i);
221 raw_spin_lock_irqsave(&sparse_irq_lock, flags);
222 bitmap_clear(allocated_irqs, start, cnt);
223 raw_spin_unlock_irqrestore(&sparse_irq_lock, flags);
227 struct irq_desc * __ref irq_to_desc_alloc_node(unsigned int irq, int node)
229 int res = irq_alloc_descs(irq, irq, 1, node);
231 if (res == -EEXIST || res == irq)
232 return irq_to_desc(irq);
236 int __init early_irq_init(void)
238 int i, initcnt, node = first_online_node;
239 struct irq_desc *desc;
241 init_irq_default_affinity();
243 /* Let arch update nr_irqs and return the nr of preallocated irqs */
244 initcnt = arch_probe_nr_irqs();
245 printk(KERN_INFO "NR_IRQS:%d nr_irqs:%d %d\n", NR_IRQS, nr_irqs, initcnt);
247 for (i = 0; i < initcnt; i++) {
248 desc = alloc_desc(i, node);
249 set_bit(i, allocated_irqs);
250 irq_insert_desc(i, desc);
252 return arch_early_irq_init();
255 #else /* !CONFIG_SPARSE_IRQ */
257 struct irq_desc irq_desc[NR_IRQS] __cacheline_aligned_in_smp = {
258 [0 ... NR_IRQS-1] = {
259 .status = IRQ_DEFAULT_INIT_FLAGS,
260 .handle_irq = handle_bad_irq,
262 .lock = __RAW_SPIN_LOCK_UNLOCKED(irq_desc->lock),
266 static unsigned int kstat_irqs_all[NR_IRQS][NR_CPUS];
267 int __init early_irq_init(void)
269 int count, i, node = first_online_node;
270 struct irq_desc *desc;
272 init_irq_default_affinity();
274 printk(KERN_INFO "NR_IRQS:%d\n", NR_IRQS);
277 count = ARRAY_SIZE(irq_desc);
279 for (i = 0; i < count; i++) {
280 desc[i].irq_data.irq = i;
281 desc[i].irq_data.chip = &no_irq_chip;
282 desc[i].kstat_irqs = kstat_irqs_all[i];
283 alloc_masks(desc + i, GFP_KERNEL, node);
284 desc_smp_init(desc + i, node);
285 lockdep_set_class(&desc[i].lock, &irq_desc_lock_class);
287 return arch_early_irq_init();
290 struct irq_desc *irq_to_desc(unsigned int irq)
292 return (irq < NR_IRQS) ? irq_desc + irq : NULL;
295 struct irq_desc *irq_to_desc_alloc_node(unsigned int irq, int node)
297 return irq_to_desc(irq);
300 static void free_desc(unsigned int irq)
302 dynamic_irq_cleanup(irq);
305 static inline int alloc_descs(unsigned int start, unsigned int cnt, int node)
309 #endif /* !CONFIG_SPARSE_IRQ */
311 /* Dynamic interrupt handling */
314 * irq_free_descs - free irq descriptors
315 * @from: Start of descriptor range
316 * @cnt: Number of consecutive irqs to free
318 void irq_free_descs(unsigned int from, unsigned int cnt)
323 if (from >= nr_irqs || (from + cnt) > nr_irqs)
326 for (i = 0; i < cnt; i++)
329 raw_spin_lock_irqsave(&sparse_irq_lock, flags);
330 bitmap_clear(allocated_irqs, from, cnt);
331 raw_spin_unlock_irqrestore(&sparse_irq_lock, flags);
335 * irq_alloc_descs - allocate and initialize a range of irq descriptors
336 * @irq: Allocate for specific irq number if irq >= 0
337 * @from: Start the search from this irq number
338 * @cnt: Number of consecutive irqs to allocate.
339 * @node: Preferred node on which the irq descriptor should be allocated
341 * Returns the first irq number or error code
344 irq_alloc_descs(int irq, unsigned int from, unsigned int cnt, int node)
352 raw_spin_lock_irqsave(&sparse_irq_lock, flags);
354 start = bitmap_find_next_zero_area(allocated_irqs, nr_irqs, from, cnt, 0);
356 if (irq >=0 && start != irq)
360 if (start >= nr_irqs)
363 bitmap_set(allocated_irqs, start, cnt);
364 raw_spin_unlock_irqrestore(&sparse_irq_lock, flags);
365 return alloc_descs(start, cnt, node);
368 raw_spin_unlock_irqrestore(&sparse_irq_lock, flags);
373 * irq_reserve_irqs - mark irqs allocated
374 * @from: mark from irq number
375 * @cnt: number of irqs to mark
377 * Returns 0 on success or an appropriate error code
379 int irq_reserve_irqs(unsigned int from, unsigned int cnt)
385 if (!cnt || (from + cnt) > nr_irqs)
388 raw_spin_lock_irqsave(&sparse_irq_lock, flags);
389 start = bitmap_find_next_zero_area(allocated_irqs, nr_irqs, from, cnt, 0);
391 bitmap_set(allocated_irqs, start, cnt);
394 raw_spin_unlock_irqrestore(&sparse_irq_lock, flags);
399 * irq_get_next_irq - get next allocated irq number
400 * @offset: where to start the search
402 * Returns next irq number after offset or nr_irqs if none is found.
404 unsigned int irq_get_next_irq(unsigned int offset)
406 return find_next_bit(allocated_irqs, nr_irqs, offset);
410 * dynamic_irq_cleanup - cleanup a dynamically allocated irq
411 * @irq: irq number to initialize
413 void dynamic_irq_cleanup(unsigned int irq)
415 struct irq_desc *desc = irq_to_desc(irq);
418 raw_spin_lock_irqsave(&desc->lock, flags);
419 desc_set_defaults(irq, desc, desc_node(desc));
420 raw_spin_unlock_irqrestore(&desc->lock, flags);
423 unsigned int kstat_irqs_cpu(unsigned int irq, int cpu)
425 struct irq_desc *desc = irq_to_desc(irq);
426 return desc ? desc->kstat_irqs[cpu] : 0;