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);
60 alloc_masks(struct irq_desc *desc, gfp_t gfp, int node) { return 0; }
61 static inline void desc_smp_init(struct irq_desc *desc, int node) { }
64 static void desc_set_defaults(unsigned int irq, struct irq_desc *desc, int node)
66 desc->irq_data.irq = irq;
67 desc->irq_data.chip = &no_irq_chip;
68 desc->irq_data.chip_data = NULL;
69 desc->irq_data.handler_data = NULL;
70 desc->irq_data.msi_desc = NULL;
71 desc->status = IRQ_DEFAULT_INIT_FLAGS;
72 desc->handle_irq = handle_bad_irq;
75 memset(desc->kstat_irqs, 0, nr_cpu_ids * sizeof(*(desc->kstat_irqs)));
76 desc_smp_init(desc, node);
79 int nr_irqs = NR_IRQS;
80 EXPORT_SYMBOL_GPL(nr_irqs);
82 DEFINE_RAW_SPINLOCK(sparse_irq_lock);
83 static DECLARE_BITMAP(allocated_irqs, NR_IRQS);
85 #ifdef CONFIG_SPARSE_IRQ
87 void __ref init_kstat_irqs(struct irq_desc *desc, int node, int nr)
91 ptr = kzalloc_node(nr * sizeof(*desc->kstat_irqs),
95 * don't overwite if can not get new one
96 * init_copy_kstat_irqs() could still use old one
99 printk(KERN_DEBUG " alloc kstat_irqs on node %d\n", node);
100 desc->kstat_irqs = ptr;
104 static RADIX_TREE(irq_desc_tree, GFP_ATOMIC);
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 void replace_irq_desc(unsigned int irq, struct irq_desc *desc)
120 ptr = radix_tree_lookup_slot(&irq_desc_tree, irq);
122 radix_tree_replace_slot(ptr, desc);
125 static void delete_irq_desc(unsigned int irq)
127 radix_tree_delete(&irq_desc_tree, irq);
131 static void free_masks(struct irq_desc *desc)
133 #ifdef CONFIG_GENERIC_PENDING_IRQ
134 free_cpumask_var(desc->pending_mask);
136 free_cpumask_var(desc->affinity);
139 static inline void free_masks(struct irq_desc *desc) { }
142 static struct irq_desc *alloc_desc(int irq, int node)
144 /* Temporary hack until we can switch to GFP_KERNEL */
145 gfp_t gfp = gfp_allowed_mask == GFP_BOOT_MASK ? GFP_NOWAIT : GFP_ATOMIC;
146 struct irq_desc *desc;
148 desc = kzalloc_node(sizeof(*desc), gfp, node);
151 /* allocate based on nr_cpu_ids */
152 desc->kstat_irqs = kzalloc_node(nr_cpu_ids * sizeof(*desc->kstat_irqs),
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);
163 desc_set_defaults(irq, desc, node);
168 kfree(desc->kstat_irqs);
174 static void free_desc(unsigned int irq)
176 struct irq_desc *desc = irq_to_desc(irq);
179 unregister_irq_proc(irq, desc);
181 raw_spin_lock_irqsave(&sparse_irq_lock, flags);
182 delete_irq_desc(irq);
183 raw_spin_unlock_irqrestore(&sparse_irq_lock, flags);
186 kfree(desc->kstat_irqs);
190 static int alloc_descs(unsigned int start, unsigned int cnt, int node)
192 struct irq_desc *desc;
196 for (i = 0; i < cnt; i++) {
197 desc = alloc_desc(start + i, node);
200 /* temporary until I fixed x86 madness */
201 arch_init_chip_data(desc, node);
202 raw_spin_lock_irqsave(&sparse_irq_lock, flags);
203 irq_insert_desc(start + i, desc);
204 raw_spin_unlock_irqrestore(&sparse_irq_lock, flags);
209 for (i--; i >= 0; i--)
210 free_desc(start + i);
212 raw_spin_lock_irqsave(&sparse_irq_lock, flags);
213 bitmap_clear(allocated_irqs, start, cnt);
214 raw_spin_unlock_irqrestore(&sparse_irq_lock, flags);
218 struct irq_desc * __ref irq_to_desc_alloc_node(unsigned int irq, int node)
220 int res = irq_alloc_descs(irq, irq, 1, node);
222 if (res == -EEXIST || res == irq)
223 return irq_to_desc(irq);
227 int __init early_irq_init(void)
229 int i, initcnt, node = first_online_node;
230 struct irq_desc *desc;
232 init_irq_default_affinity();
234 /* Let arch update nr_irqs and return the nr of preallocated irqs */
235 initcnt = arch_probe_nr_irqs();
236 printk(KERN_INFO "NR_IRQS:%d nr_irqs:%d %d\n", NR_IRQS, nr_irqs, initcnt);
238 for (i = 0; i < initcnt; i++) {
239 desc = alloc_desc(i, node);
240 set_bit(i, allocated_irqs);
241 irq_insert_desc(i, desc);
243 return arch_early_irq_init();
246 #else /* !CONFIG_SPARSE_IRQ */
248 struct irq_desc irq_desc[NR_IRQS] __cacheline_aligned_in_smp = {
249 [0 ... NR_IRQS-1] = {
250 .status = IRQ_DEFAULT_INIT_FLAGS,
251 .handle_irq = handle_bad_irq,
253 .lock = __RAW_SPIN_LOCK_UNLOCKED(irq_desc->lock),
257 static unsigned int kstat_irqs_all[NR_IRQS][NR_CPUS];
258 int __init early_irq_init(void)
260 int count, i, node = first_online_node;
261 struct irq_desc *desc;
263 init_irq_default_affinity();
265 printk(KERN_INFO "NR_IRQS:%d\n", NR_IRQS);
268 count = ARRAY_SIZE(irq_desc);
270 for (i = 0; i < count; i++) {
271 desc[i].irq_data.irq = i;
272 desc[i].irq_data.chip = &no_irq_chip;
273 desc[i].kstat_irqs = kstat_irqs_all[i];
274 alloc_masks(desc + i, GFP_KERNEL, node);
275 desc_smp_init(desc + i, node);
276 lockdep_set_class(&desc[i].lock, &irq_desc_lock_class);
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 struct irq_desc *irq_to_desc_alloc_node(unsigned int irq, int node)
288 return irq_to_desc(irq);
292 static inline int desc_node(struct irq_desc *desc)
294 return desc->irq_data.node;
297 static inline int desc_node(struct irq_desc *desc) { return 0; }
300 static void free_desc(unsigned int irq)
302 struct irq_desc *desc = irq_to_desc(irq);
305 raw_spin_lock_irqsave(&desc->lock, flags);
306 desc_set_defaults(irq, desc, desc_node(desc));
307 raw_spin_unlock_irqrestore(&desc->lock, flags);
310 static inline int alloc_descs(unsigned int start, unsigned int cnt, int node)
314 #endif /* !CONFIG_SPARSE_IRQ */
316 /* Dynamic interrupt handling */
319 * irq_free_descs - free irq descriptors
320 * @from: Start of descriptor range
321 * @cnt: Number of consecutive irqs to free
323 void irq_free_descs(unsigned int from, unsigned int cnt)
328 if (from >= nr_irqs || (from + cnt) > nr_irqs)
331 for (i = 0; i < cnt; i++)
334 raw_spin_lock_irqsave(&sparse_irq_lock, flags);
335 bitmap_clear(allocated_irqs, from, cnt);
336 raw_spin_unlock_irqrestore(&sparse_irq_lock, flags);
340 * irq_alloc_descs - allocate and initialize a range of irq descriptors
341 * @irq: Allocate for specific irq number if irq >= 0
342 * @from: Start the search from this irq number
343 * @cnt: Number of consecutive irqs to allocate.
344 * @node: Preferred node on which the irq descriptor should be allocated
346 * Returns the first irq number or error code
349 irq_alloc_descs(int irq, unsigned int from, unsigned int cnt, int node)
357 raw_spin_lock_irqsave(&sparse_irq_lock, flags);
359 start = bitmap_find_next_zero_area(allocated_irqs, nr_irqs, from, cnt, 0);
361 if (irq >=0 && start != irq)
365 if (start >= nr_irqs)
368 bitmap_set(allocated_irqs, start, cnt);
369 raw_spin_unlock_irqrestore(&sparse_irq_lock, flags);
370 return alloc_descs(start, cnt, node);
373 raw_spin_unlock_irqrestore(&sparse_irq_lock, flags);
378 * irq_reserve_irqs - mark irqs allocated
379 * @from: mark from irq number
380 * @cnt: number of irqs to mark
382 * Returns 0 on success or an appropriate error code
384 int irq_reserve_irqs(unsigned int from, unsigned int cnt)
390 if (!cnt || (from + cnt) > nr_irqs)
393 raw_spin_lock_irqsave(&sparse_irq_lock, flags);
394 start = bitmap_find_next_zero_area(allocated_irqs, nr_irqs, from, cnt, 0);
396 bitmap_set(allocated_irqs, start, cnt);
399 raw_spin_unlock_irqrestore(&sparse_irq_lock, flags);
404 * irq_get_next_irq - get next allocated irq number
405 * @offset: where to start the search
407 * Returns next irq number after offset or nr_irqs if none is found.
409 unsigned int irq_get_next_irq(unsigned int offset)
411 return find_next_bit(allocated_irqs, nr_irqs, offset);
414 /* Statistics access */
415 void clear_kstat_irqs(struct irq_desc *desc)
417 memset(desc->kstat_irqs, 0, nr_cpu_ids * sizeof(*(desc->kstat_irqs)));
420 unsigned int kstat_irqs_cpu(unsigned int irq, int cpu)
422 struct irq_desc *desc = irq_to_desc(irq);
423 return desc ? desc->kstat_irqs[cpu] : 0;