diff options
Diffstat (limited to 'kernel/irq/irqdesc.c')
-rw-r--r-- | kernel/irq/irqdesc.c | 466 |
1 files changed, 466 insertions, 0 deletions
diff --git a/kernel/irq/irqdesc.c b/kernel/irq/irqdesc.c new file mode 100644 index 000000000000..4c60a50e66b2 --- /dev/null +++ b/kernel/irq/irqdesc.c | |||
@@ -0,0 +1,466 @@ | |||
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 | } | ||