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 static 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 static DEFINE_MUTEX(sparse_irq_lock);
94 static DECLARE_BITMAP(allocated_irqs, NR_IRQS);
96 #ifdef CONFIG_SPARSE_IRQ
98 static RADIX_TREE(irq_desc_tree, GFP_ATOMIC);
100 static void irq_insert_desc(unsigned int irq, struct irq_desc *desc)
102 radix_tree_insert(&irq_desc_tree, irq, desc);
105 struct irq_desc *irq_to_desc(unsigned int irq)
107 return radix_tree_lookup(&irq_desc_tree, irq);
110 static void delete_irq_desc(unsigned int irq)
112 radix_tree_delete(&irq_desc_tree, irq);
116 static void free_masks(struct irq_desc *desc)
118 #ifdef CONFIG_GENERIC_PENDING_IRQ
119 free_cpumask_var(desc->pending_mask);
121 free_cpumask_var(desc->affinity);
124 static inline void free_masks(struct irq_desc *desc) { }
127 static struct irq_desc *alloc_desc(int irq, int node)
129 /* Temporary hack until we can switch to GFP_KERNEL */
130 gfp_t gfp = gfp_allowed_mask == GFP_BOOT_MASK ? GFP_NOWAIT : GFP_ATOMIC;
131 struct irq_desc *desc;
133 desc = kzalloc_node(sizeof(*desc), gfp, node);
136 /* allocate based on nr_cpu_ids */
137 desc->kstat_irqs = kzalloc_node(nr_cpu_ids * sizeof(*desc->kstat_irqs),
139 if (!desc->kstat_irqs)
142 if (alloc_masks(desc, gfp, node))
145 raw_spin_lock_init(&desc->lock);
146 lockdep_set_class(&desc->lock, &irq_desc_lock_class);
148 desc_set_defaults(irq, desc, node);
153 kfree(desc->kstat_irqs);
159 static void free_desc(unsigned int irq)
161 struct irq_desc *desc = irq_to_desc(irq);
163 unregister_irq_proc(irq, desc);
165 mutex_lock(&sparse_irq_lock);
166 delete_irq_desc(irq);
167 mutex_unlock(&sparse_irq_lock);
170 kfree(desc->kstat_irqs);
174 static int alloc_descs(unsigned int start, unsigned int cnt, int node)
176 struct irq_desc *desc;
179 for (i = 0; i < cnt; i++) {
180 desc = alloc_desc(start + i, node);
183 mutex_lock(&sparse_irq_lock);
184 irq_insert_desc(start + i, desc);
185 mutex_unlock(&sparse_irq_lock);
190 for (i--; i >= 0; i--)
191 free_desc(start + i);
193 mutex_lock(&sparse_irq_lock);
194 bitmap_clear(allocated_irqs, start, cnt);
195 mutex_unlock(&sparse_irq_lock);
199 struct irq_desc * __ref irq_to_desc_alloc_node(unsigned int irq, int node)
201 int res = irq_alloc_descs(irq, irq, 1, node);
203 if (res == -EEXIST || res == irq)
204 return irq_to_desc(irq);
208 int __init early_irq_init(void)
210 int i, initcnt, node = first_online_node;
211 struct irq_desc *desc;
213 init_irq_default_affinity();
215 /* Let arch update nr_irqs and return the nr of preallocated irqs */
216 initcnt = arch_probe_nr_irqs();
217 printk(KERN_INFO "NR_IRQS:%d nr_irqs:%d %d\n", NR_IRQS, nr_irqs, initcnt);
219 for (i = 0; i < initcnt; i++) {
220 desc = alloc_desc(i, node);
221 set_bit(i, allocated_irqs);
222 irq_insert_desc(i, desc);
224 return arch_early_irq_init();
227 #else /* !CONFIG_SPARSE_IRQ */
229 struct irq_desc irq_desc[NR_IRQS] __cacheline_aligned_in_smp = {
230 [0 ... NR_IRQS-1] = {
231 .status = IRQ_DEFAULT_INIT_FLAGS,
232 .handle_irq = handle_bad_irq,
234 .lock = __RAW_SPIN_LOCK_UNLOCKED(irq_desc->lock),
238 static unsigned int kstat_irqs_all[NR_IRQS][NR_CPUS];
239 int __init early_irq_init(void)
241 int count, i, node = first_online_node;
242 struct irq_desc *desc;
244 init_irq_default_affinity();
246 printk(KERN_INFO "NR_IRQS:%d\n", NR_IRQS);
249 count = ARRAY_SIZE(irq_desc);
251 for (i = 0; i < count; i++) {
252 desc[i].irq_data.irq = i;
253 desc[i].irq_data.chip = &no_irq_chip;
254 desc[i].kstat_irqs = kstat_irqs_all[i];
255 alloc_masks(desc + i, GFP_KERNEL, node);
256 desc_smp_init(desc + i, node);
257 lockdep_set_class(&desc[i].lock, &irq_desc_lock_class);
259 return arch_early_irq_init();
262 struct irq_desc *irq_to_desc(unsigned int irq)
264 return (irq < NR_IRQS) ? irq_desc + irq : NULL;
267 struct irq_desc *irq_to_desc_alloc_node(unsigned int irq, int node)
269 return irq_to_desc(irq);
272 static void free_desc(unsigned int irq)
274 dynamic_irq_cleanup(irq);
277 static inline int alloc_descs(unsigned int start, unsigned int cnt, int node)
281 #endif /* !CONFIG_SPARSE_IRQ */
283 /* Dynamic interrupt handling */
286 * irq_free_descs - free irq descriptors
287 * @from: Start of descriptor range
288 * @cnt: Number of consecutive irqs to free
290 void irq_free_descs(unsigned int from, unsigned int cnt)
294 if (from >= nr_irqs || (from + cnt) > nr_irqs)
297 for (i = 0; i < cnt; i++)
300 mutex_lock(&sparse_irq_lock);
301 bitmap_clear(allocated_irqs, from, cnt);
302 mutex_unlock(&sparse_irq_lock);
306 * irq_alloc_descs - allocate and initialize a range of irq descriptors
307 * @irq: Allocate for specific irq number if irq >= 0
308 * @from: Start the search from this irq number
309 * @cnt: Number of consecutive irqs to allocate.
310 * @node: Preferred node on which the irq descriptor should be allocated
312 * Returns the first irq number or error code
315 irq_alloc_descs(int irq, unsigned int from, unsigned int cnt, int node)
322 mutex_lock(&sparse_irq_lock);
324 start = bitmap_find_next_zero_area(allocated_irqs, nr_irqs, from, cnt, 0);
326 if (irq >=0 && start != irq)
330 if (start >= nr_irqs)
333 bitmap_set(allocated_irqs, start, cnt);
334 mutex_unlock(&sparse_irq_lock);
335 return alloc_descs(start, cnt, node);
338 mutex_unlock(&sparse_irq_lock);
343 * irq_reserve_irqs - mark irqs allocated
344 * @from: mark from irq number
345 * @cnt: number of irqs to mark
347 * Returns 0 on success or an appropriate error code
349 int irq_reserve_irqs(unsigned int from, unsigned int cnt)
354 if (!cnt || (from + cnt) > nr_irqs)
357 mutex_lock(&sparse_irq_lock);
358 start = bitmap_find_next_zero_area(allocated_irqs, nr_irqs, from, cnt, 0);
360 bitmap_set(allocated_irqs, start, cnt);
363 mutex_unlock(&sparse_irq_lock);
368 * irq_get_next_irq - get next allocated irq number
369 * @offset: where to start the search
371 * Returns next irq number after offset or nr_irqs if none is found.
373 unsigned int irq_get_next_irq(unsigned int offset)
375 return find_next_bit(allocated_irqs, nr_irqs, offset);
379 * dynamic_irq_cleanup - cleanup a dynamically allocated irq
380 * @irq: irq number to initialize
382 void dynamic_irq_cleanup(unsigned int irq)
384 struct irq_desc *desc = irq_to_desc(irq);
387 raw_spin_lock_irqsave(&desc->lock, flags);
388 desc_set_defaults(irq, desc, desc_node(desc));
389 raw_spin_unlock_irqrestore(&desc->lock, flags);
392 unsigned int kstat_irqs_cpu(unsigned int irq, int cpu)
394 struct irq_desc *desc = irq_to_desc(irq);
395 return desc ? desc->kstat_irqs[cpu] : 0;