genirq: replace irq_gc_ack() with {set,clr}_bit variants (fwd)
[linux-2.6.git] / kernel / irq / irqdesc.c
1 /*
2  * Copyright (C) 1992, 1998-2006 Linus Torvalds, Ingo Molnar
3  * Copyright (C) 2005-2006, Thomas Gleixner, Russell King
4  *
5  * This file contains the interrupt descriptor management code
6  *
7  * Detailed information is available in Documentation/DocBook/genericirq
8  *
9  */
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>
17
18 #include "internals.h"
19
20 /*
21  * lockdep: we want to handle all irq_desc locks as a single lock-class:
22  */
23 static struct lock_class_key irq_desc_lock_class;
24
25 #if defined(CONFIG_SMP)
26 static void __init init_irq_default_affinity(void)
27 {
28         alloc_cpumask_var(&irq_default_affinity, GFP_NOWAIT);
29         cpumask_setall(irq_default_affinity);
30 }
31 #else
32 static void __init init_irq_default_affinity(void)
33 {
34 }
35 #endif
36
37 #ifdef CONFIG_SMP
38 static int alloc_masks(struct irq_desc *desc, gfp_t gfp, int node)
39 {
40         if (!zalloc_cpumask_var_node(&desc->irq_data.affinity, gfp, node))
41                 return -ENOMEM;
42
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);
46                 return -ENOMEM;
47         }
48 #endif
49         return 0;
50 }
51
52 static void desc_smp_init(struct irq_desc *desc, int node)
53 {
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);
58 #endif
59 }
60
61 static inline int desc_node(struct irq_desc *desc)
62 {
63         return desc->irq_data.node;
64 }
65
66 #else
67 static inline int
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; }
71 #endif
72
73 static void desc_set_defaults(unsigned int irq, struct irq_desc *desc, int node)
74 {
75         int cpu;
76
77         desc->irq_data.irq = irq;
78         desc->irq_data.chip = &no_irq_chip;
79         desc->irq_data.chip_data = NULL;
80         desc->irq_data.handler_data = NULL;
81         desc->irq_data.msi_desc = NULL;
82         irq_settings_clr_and_set(desc, ~0, _IRQ_DEFAULT_INIT_FLAGS);
83         irqd_set(&desc->irq_data, IRQD_IRQ_DISABLED);
84         desc->handle_irq = handle_bad_irq;
85         desc->depth = 1;
86         desc->irq_count = 0;
87         desc->irqs_unhandled = 0;
88         desc->name = NULL;
89         for_each_possible_cpu(cpu)
90                 *per_cpu_ptr(desc->kstat_irqs, cpu) = 0;
91         desc_smp_init(desc, node);
92 }
93
94 int nr_irqs = NR_IRQS;
95 EXPORT_SYMBOL_GPL(nr_irqs);
96
97 static DEFINE_MUTEX(sparse_irq_lock);
98 static DECLARE_BITMAP(allocated_irqs, IRQ_BITMAP_BITS);
99
100 #ifdef CONFIG_SPARSE_IRQ
101
102 static RADIX_TREE(irq_desc_tree, GFP_KERNEL);
103
104 static void irq_insert_desc(unsigned int irq, struct irq_desc *desc)
105 {
106         radix_tree_insert(&irq_desc_tree, irq, desc);
107 }
108
109 struct irq_desc *irq_to_desc(unsigned int irq)
110 {
111         return radix_tree_lookup(&irq_desc_tree, irq);
112 }
113
114 static void delete_irq_desc(unsigned int irq)
115 {
116         radix_tree_delete(&irq_desc_tree, irq);
117 }
118
119 #ifdef CONFIG_SMP
120 static void free_masks(struct irq_desc *desc)
121 {
122 #ifdef CONFIG_GENERIC_PENDING_IRQ
123         free_cpumask_var(desc->pending_mask);
124 #endif
125         free_cpumask_var(desc->irq_data.affinity);
126 }
127 #else
128 static inline void free_masks(struct irq_desc *desc) { }
129 #endif
130
131 static struct irq_desc *alloc_desc(int irq, int node)
132 {
133         struct irq_desc *desc;
134         gfp_t gfp = GFP_KERNEL;
135
136         desc = kzalloc_node(sizeof(*desc), gfp, node);
137         if (!desc)
138                 return NULL;
139         /* allocate based on nr_cpu_ids */
140         desc->kstat_irqs = alloc_percpu(unsigned int);
141         if (!desc->kstat_irqs)
142                 goto err_desc;
143
144         if (alloc_masks(desc, gfp, node))
145                 goto err_kstat;
146
147         raw_spin_lock_init(&desc->lock);
148         lockdep_set_class(&desc->lock, &irq_desc_lock_class);
149
150         desc_set_defaults(irq, desc, node);
151
152         return desc;
153
154 err_kstat:
155         free_percpu(desc->kstat_irqs);
156 err_desc:
157         kfree(desc);
158         return NULL;
159 }
160
161 static void free_desc(unsigned int irq)
162 {
163         struct irq_desc *desc = irq_to_desc(irq);
164
165         unregister_irq_proc(irq, desc);
166
167         mutex_lock(&sparse_irq_lock);
168         delete_irq_desc(irq);
169         mutex_unlock(&sparse_irq_lock);
170
171         free_masks(desc);
172         free_percpu(desc->kstat_irqs);
173         kfree(desc);
174 }
175
176 static int alloc_descs(unsigned int start, unsigned int cnt, int node)
177 {
178         struct irq_desc *desc;
179         int i;
180
181         for (i = 0; i < cnt; i++) {
182                 desc = alloc_desc(start + i, node);
183                 if (!desc)
184                         goto err;
185                 mutex_lock(&sparse_irq_lock);
186                 irq_insert_desc(start + i, desc);
187                 mutex_unlock(&sparse_irq_lock);
188         }
189         return start;
190
191 err:
192         for (i--; i >= 0; i--)
193                 free_desc(start + i);
194
195         mutex_lock(&sparse_irq_lock);
196         bitmap_clear(allocated_irqs, start, cnt);
197         mutex_unlock(&sparse_irq_lock);
198         return -ENOMEM;
199 }
200
201 static int irq_expand_nr_irqs(unsigned int nr)
202 {
203         if (nr > IRQ_BITMAP_BITS)
204                 return -ENOMEM;
205         nr_irqs = nr;
206         return 0;
207 }
208
209 int __init early_irq_init(void)
210 {
211         int i, initcnt, node = first_online_node;
212         struct irq_desc *desc;
213
214         init_irq_default_affinity();
215
216         /* Let arch update nr_irqs and return the nr of preallocated irqs */
217         initcnt = arch_probe_nr_irqs();
218         printk(KERN_INFO "NR_IRQS:%d nr_irqs:%d %d\n", NR_IRQS, nr_irqs, initcnt);
219
220         if (WARN_ON(nr_irqs > IRQ_BITMAP_BITS))
221                 nr_irqs = IRQ_BITMAP_BITS;
222
223         if (WARN_ON(initcnt > IRQ_BITMAP_BITS))
224                 initcnt = IRQ_BITMAP_BITS;
225
226         if (initcnt > nr_irqs)
227                 nr_irqs = initcnt;
228
229         for (i = 0; i < initcnt; i++) {
230                 desc = alloc_desc(i, node);
231                 set_bit(i, allocated_irqs);
232                 irq_insert_desc(i, desc);
233         }
234         return arch_early_irq_init();
235 }
236
237 #else /* !CONFIG_SPARSE_IRQ */
238
239 struct irq_desc irq_desc[NR_IRQS] __cacheline_aligned_in_smp = {
240         [0 ... NR_IRQS-1] = {
241                 .handle_irq     = handle_bad_irq,
242                 .depth          = 1,
243                 .lock           = __RAW_SPIN_LOCK_UNLOCKED(irq_desc->lock),
244         }
245 };
246
247 int __init early_irq_init(void)
248 {
249         int count, i, node = first_online_node;
250         struct irq_desc *desc;
251
252         init_irq_default_affinity();
253
254         printk(KERN_INFO "NR_IRQS:%d\n", NR_IRQS);
255
256         desc = irq_desc;
257         count = ARRAY_SIZE(irq_desc);
258
259         for (i = 0; i < count; i++) {
260                 desc[i].kstat_irqs = alloc_percpu(unsigned int);
261                 alloc_masks(&desc[i], GFP_KERNEL, node);
262                 raw_spin_lock_init(&desc[i].lock);
263                 lockdep_set_class(&desc[i].lock, &irq_desc_lock_class);
264                 desc_set_defaults(i, &desc[i], node);
265         }
266         return arch_early_irq_init();
267 }
268
269 struct irq_desc *irq_to_desc(unsigned int irq)
270 {
271         return (irq < NR_IRQS) ? irq_desc + irq : NULL;
272 }
273
274 static void free_desc(unsigned int irq)
275 {
276         dynamic_irq_cleanup(irq);
277 }
278
279 static inline int alloc_descs(unsigned int start, unsigned int cnt, int node)
280 {
281         return start;
282 }
283
284 static int irq_expand_nr_irqs(unsigned int nr)
285 {
286         return -ENOMEM;
287 }
288
289 #endif /* !CONFIG_SPARSE_IRQ */
290
291 /**
292  * generic_handle_irq - Invoke the handler for a particular irq
293  * @irq:        The irq number to handle
294  *
295  */
296 int generic_handle_irq(unsigned int irq)
297 {
298         struct irq_desc *desc = irq_to_desc(irq);
299
300         if (!desc)
301                 return -EINVAL;
302         generic_handle_irq_desc(irq, desc);
303         return 0;
304 }
305 EXPORT_SYMBOL_GPL(generic_handle_irq);
306
307 /* Dynamic interrupt handling */
308
309 /**
310  * irq_free_descs - free irq descriptors
311  * @from:       Start of descriptor range
312  * @cnt:        Number of consecutive irqs to free
313  */
314 void irq_free_descs(unsigned int from, unsigned int cnt)
315 {
316         int i;
317
318         if (from >= nr_irqs || (from + cnt) > nr_irqs)
319                 return;
320
321         for (i = 0; i < cnt; i++)
322                 free_desc(from + i);
323
324         mutex_lock(&sparse_irq_lock);
325         bitmap_clear(allocated_irqs, from, cnt);
326         mutex_unlock(&sparse_irq_lock);
327 }
328 EXPORT_SYMBOL_GPL(irq_free_descs);
329
330 /**
331  * irq_alloc_descs - allocate and initialize a range of irq descriptors
332  * @irq:        Allocate for specific irq number if irq >= 0
333  * @from:       Start the search from this irq number
334  * @cnt:        Number of consecutive irqs to allocate.
335  * @node:       Preferred node on which the irq descriptor should be allocated
336  *
337  * Returns the first irq number or error code
338  */
339 int __ref
340 irq_alloc_descs(int irq, unsigned int from, unsigned int cnt, int node)
341 {
342         int start, ret;
343
344         if (!cnt)
345                 return -EINVAL;
346
347         if (irq >= 0) {
348                 if (from > irq)
349                         return -EINVAL;
350                 from = irq;
351         }
352
353         mutex_lock(&sparse_irq_lock);
354
355         start = bitmap_find_next_zero_area(allocated_irqs, IRQ_BITMAP_BITS,
356                                            from, cnt, 0);
357         ret = -EEXIST;
358         if (irq >=0 && start != irq)
359                 goto err;
360
361         if (start + cnt > nr_irqs) {
362                 ret = irq_expand_nr_irqs(start + cnt);
363                 if (ret)
364                         goto err;
365         }
366
367         bitmap_set(allocated_irqs, start, cnt);
368         mutex_unlock(&sparse_irq_lock);
369         return alloc_descs(start, cnt, node);
370
371 err:
372         mutex_unlock(&sparse_irq_lock);
373         return ret;
374 }
375 EXPORT_SYMBOL_GPL(irq_alloc_descs);
376
377 /**
378  * irq_reserve_irqs - mark irqs allocated
379  * @from:       mark from irq number
380  * @cnt:        number of irqs to mark
381  *
382  * Returns 0 on success or an appropriate error code
383  */
384 int irq_reserve_irqs(unsigned int from, unsigned int cnt)
385 {
386         unsigned int start;
387         int ret = 0;
388
389         if (!cnt || (from + cnt) > nr_irqs)
390                 return -EINVAL;
391
392         mutex_lock(&sparse_irq_lock);
393         start = bitmap_find_next_zero_area(allocated_irqs, nr_irqs, from, cnt, 0);
394         if (start == from)
395                 bitmap_set(allocated_irqs, start, cnt);
396         else
397                 ret = -EEXIST;
398         mutex_unlock(&sparse_irq_lock);
399         return ret;
400 }
401
402 /**
403  * irq_get_next_irq - get next allocated irq number
404  * @offset:     where to start the search
405  *
406  * Returns next irq number after offset or nr_irqs if none is found.
407  */
408 unsigned int irq_get_next_irq(unsigned int offset)
409 {
410         return find_next_bit(allocated_irqs, nr_irqs, offset);
411 }
412
413 struct irq_desc *
414 __irq_get_desc_lock(unsigned int irq, unsigned long *flags, bool bus)
415 {
416         struct irq_desc *desc = irq_to_desc(irq);
417
418         if (desc) {
419                 if (bus)
420                         chip_bus_lock(desc);
421                 raw_spin_lock_irqsave(&desc->lock, *flags);
422         }
423         return desc;
424 }
425
426 void __irq_put_desc_unlock(struct irq_desc *desc, unsigned long flags, bool bus)
427 {
428         raw_spin_unlock_irqrestore(&desc->lock, flags);
429         if (bus)
430                 chip_bus_sync_unlock(desc);
431 }
432
433 /**
434  * dynamic_irq_cleanup - cleanup a dynamically allocated irq
435  * @irq:        irq number to initialize
436  */
437 void dynamic_irq_cleanup(unsigned int irq)
438 {
439         struct irq_desc *desc = irq_to_desc(irq);
440         unsigned long flags;
441
442         raw_spin_lock_irqsave(&desc->lock, flags);
443         desc_set_defaults(irq, desc, desc_node(desc));
444         raw_spin_unlock_irqrestore(&desc->lock, flags);
445 }
446
447 unsigned int kstat_irqs_cpu(unsigned int irq, int cpu)
448 {
449         struct irq_desc *desc = irq_to_desc(irq);
450
451         return desc && desc->kstat_irqs ?
452                         *per_cpu_ptr(desc->kstat_irqs, cpu) : 0;
453 }
454
455 unsigned int kstat_irqs(unsigned int irq)
456 {
457         struct irq_desc *desc = irq_to_desc(irq);
458         int cpu;
459         int sum = 0;
460
461         if (!desc || !desc->kstat_irqs)
462                 return 0;
463         for_each_possible_cpu(cpu)
464                 sum += *per_cpu_ptr(desc->kstat_irqs, cpu);
465         return sum;
466 }