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genirq: Implement a sane sparse_irq allocator
[mirror_ubuntu-artful-kernel.git] / kernel / irq / irqdesc.c
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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>
1f5a5b87 16#include <linux/bitmap.h>
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17
18#include "internals.h"
19
20/*
21 * lockdep: we want to handle all irq_desc locks as a single lock-class:
22 */
23struct lock_class_key irq_desc_lock_class;
24
25#if defined(CONFIG_SMP) && defined(CONFIG_GENERIC_HARDIRQS)
26static 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
32static void __init init_irq_default_affinity(void)
33{
34}
35#endif
36
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37#ifdef CONFIG_SMP
38static 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
52static void desc_smp_init(struct irq_desc *desc, int node)
53{
54 desc->node = node;
55 cpumask_copy(desc->irq_data.affinity, irq_default_affinity);
56}
57
58#else
59static inline int
60alloc_masks(struct irq_desc *desc, gfp_t gfp, int node) { return 0; }
61static inline void desc_smp_init(struct irq_desc *desc, int node) { }
62#endif
63
64static void desc_set_defaults(unsigned int irq, struct irq_desc *desc, int node)
65{
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;
73 desc->depth = 1;
74 desc->name = NULL;
75 memset(desc->kstat_irqs, 0, nr_cpu_ids * sizeof(*(desc->kstat_irqs)));
76 desc_smp_init(desc, node);
77}
78
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79int nr_irqs = NR_IRQS;
80EXPORT_SYMBOL_GPL(nr_irqs);
81
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82DEFINE_RAW_SPINLOCK(sparse_irq_lock);
83static DECLARE_BITMAP(allocated_irqs, NR_IRQS);
84
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85#ifdef CONFIG_SPARSE_IRQ
86
87static struct irq_desc irq_desc_init = {
1318a481 88 .status = IRQ_DEFAULT_INIT_FLAGS,
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89 .handle_irq = handle_bad_irq,
90 .depth = 1,
91 .lock = __RAW_SPIN_LOCK_UNLOCKED(irq_desc_init.lock),
92};
93
94void __ref init_kstat_irqs(struct irq_desc *desc, int node, int nr)
95{
96 void *ptr;
97
98 ptr = kzalloc_node(nr * sizeof(*desc->kstat_irqs),
99 GFP_ATOMIC, node);
100
101 /*
102 * don't overwite if can not get new one
103 * init_copy_kstat_irqs() could still use old one
104 */
105 if (ptr) {
106 printk(KERN_DEBUG " alloc kstat_irqs on node %d\n", node);
107 desc->kstat_irqs = ptr;
108 }
109}
110
111static void init_one_irq_desc(int irq, struct irq_desc *desc, int node)
112{
113 memcpy(desc, &irq_desc_init, sizeof(struct irq_desc));
114
115 raw_spin_lock_init(&desc->lock);
116 desc->irq_data.irq = irq;
117#ifdef CONFIG_SMP
118 desc->irq_data.node = node;
119#endif
120 lockdep_set_class(&desc->lock, &irq_desc_lock_class);
121 init_kstat_irqs(desc, node, nr_cpu_ids);
122 if (!desc->kstat_irqs) {
123 printk(KERN_ERR "can not alloc kstat_irqs\n");
124 BUG_ON(1);
125 }
126 if (!alloc_desc_masks(desc, node, false)) {
127 printk(KERN_ERR "can not alloc irq_desc cpumasks\n");
128 BUG_ON(1);
129 }
130 init_desc_masks(desc);
131 arch_init_chip_data(desc, node);
132}
133
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134static RADIX_TREE(irq_desc_tree, GFP_ATOMIC);
135
1f5a5b87 136static void irq_insert_desc(unsigned int irq, struct irq_desc *desc)
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137{
138 radix_tree_insert(&irq_desc_tree, irq, desc);
139}
140
141struct irq_desc *irq_to_desc(unsigned int irq)
142{
143 return radix_tree_lookup(&irq_desc_tree, irq);
144}
145
146void replace_irq_desc(unsigned int irq, struct irq_desc *desc)
147{
148 void **ptr;
149
150 ptr = radix_tree_lookup_slot(&irq_desc_tree, irq);
151 if (ptr)
152 radix_tree_replace_slot(ptr, desc);
153}
154
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155static void delete_irq_desc(unsigned int irq)
156{
157 radix_tree_delete(&irq_desc_tree, irq);
158}
159
160#ifdef CONFIG_SMP
161static void free_masks(struct irq_desc *desc)
162{
163#ifdef CONFIG_GENERIC_PENDING_IRQ
164 free_cpumask_var(desc->pending_mask);
165#endif
166 free_cpumask_var(desc->affinity);
167}
168#else
169static inline void free_masks(struct irq_desc *desc) { }
170#endif
171
172static struct irq_desc *alloc_desc(int irq, int node)
173{
174 struct irq_desc *desc;
175 gfp_t gfp = GFP_KERNEL;
176
177 desc = kzalloc_node(sizeof(*desc), gfp, node);
178 if (!desc)
179 return NULL;
180 /* allocate based on nr_cpu_ids */
181 desc->kstat_irqs = kzalloc_node(nr_cpu_ids * sizeof(*desc->kstat_irqs),
182 gfp, node);
183 if (!desc->kstat_irqs)
184 goto err_desc;
185
186 if (alloc_masks(desc, gfp, node))
187 goto err_kstat;
188
189 raw_spin_lock_init(&desc->lock);
190 lockdep_set_class(&desc->lock, &irq_desc_lock_class);
191
192 desc_set_defaults(irq, desc, node);
193
194 return desc;
195
196err_kstat:
197 kfree(desc->kstat_irqs);
198err_desc:
199 kfree(desc);
200 return NULL;
201}
202
203static void free_desc(unsigned int irq)
204{
205 struct irq_desc *desc = irq_to_desc(irq);
206 unsigned long flags;
207
208 raw_spin_lock_irqsave(&sparse_irq_lock, flags);
209 delete_irq_desc(irq);
210 raw_spin_unlock_irqrestore(&sparse_irq_lock, flags);
211
212 free_masks(desc);
213 kfree(desc->kstat_irqs);
214 kfree(desc);
215}
216
217static int alloc_descs(unsigned int start, unsigned int cnt, int node)
218{
219 struct irq_desc *desc;
220 unsigned long flags;
221 int i;
222
223 for (i = 0; i < cnt; i++) {
224 desc = alloc_desc(start + i, node);
225 if (!desc)
226 goto err;
227 raw_spin_lock_irqsave(&sparse_irq_lock, flags);
228 irq_insert_desc(start + i, desc);
229 raw_spin_unlock_irqrestore(&sparse_irq_lock, flags);
230 }
231 return start;
232
233err:
234 for (i--; i >= 0; i--)
235 free_desc(start + i);
236
237 raw_spin_lock_irqsave(&sparse_irq_lock, flags);
238 bitmap_clear(allocated_irqs, start, cnt);
239 raw_spin_unlock_irqrestore(&sparse_irq_lock, flags);
240 return -ENOMEM;
241}
242
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243static struct irq_desc irq_desc_legacy[NR_IRQS_LEGACY] __cacheline_aligned_in_smp = {
244 [0 ... NR_IRQS_LEGACY-1] = {
1318a481 245 .status = IRQ_DEFAULT_INIT_FLAGS,
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246 .handle_irq = handle_bad_irq,
247 .depth = 1,
248 .lock = __RAW_SPIN_LOCK_UNLOCKED(irq_desc_init.lock),
249 }
250};
251
252static unsigned int *kstat_irqs_legacy;
253
254int __init early_irq_init(void)
255{
256 struct irq_desc *desc;
257 int legacy_count;
258 int node;
259 int i;
260
261 init_irq_default_affinity();
262
263 /* initialize nr_irqs based on nr_cpu_ids */
264 arch_probe_nr_irqs();
265 printk(KERN_INFO "NR_IRQS:%d nr_irqs:%d\n", NR_IRQS, nr_irqs);
266
267 desc = irq_desc_legacy;
268 legacy_count = ARRAY_SIZE(irq_desc_legacy);
269 node = first_online_node;
270
271 /* allocate based on nr_cpu_ids */
272 kstat_irqs_legacy = kzalloc_node(NR_IRQS_LEGACY * nr_cpu_ids *
273 sizeof(int), GFP_NOWAIT, node);
274
275 irq_desc_init.irq_data.chip = &no_irq_chip;
276
277 for (i = 0; i < legacy_count; i++) {
278 desc[i].irq_data.irq = i;
279 desc[i].irq_data.chip = &no_irq_chip;
280#ifdef CONFIG_SMP
281 desc[i].irq_data.node = node;
282#endif
283 desc[i].kstat_irqs = kstat_irqs_legacy + i * nr_cpu_ids;
284 lockdep_set_class(&desc[i].lock, &irq_desc_lock_class);
285 alloc_desc_masks(&desc[i], node, true);
286 init_desc_masks(&desc[i]);
1f5a5b87 287 irq_insert_desc(i, &desc[i]);
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288 }
289
290 return arch_early_irq_init();
291}
292
293struct irq_desc * __ref irq_to_desc_alloc_node(unsigned int irq, int node)
294{
295 struct irq_desc *desc;
296 unsigned long flags;
297
298 if (irq >= nr_irqs) {
299 WARN(1, "irq (%d) >= nr_irqs (%d) in irq_to_desc_alloc\n",
300 irq, nr_irqs);
301 return NULL;
302 }
303
304 desc = irq_to_desc(irq);
305 if (desc)
306 return desc;
307
308 raw_spin_lock_irqsave(&sparse_irq_lock, flags);
309
310 /* We have to check it to avoid races with another CPU */
311 desc = irq_to_desc(irq);
312 if (desc)
313 goto out_unlock;
314
315 desc = kzalloc_node(sizeof(*desc), GFP_ATOMIC, node);
316
317 printk(KERN_DEBUG " alloc irq_desc for %d on node %d\n", irq, node);
318 if (!desc) {
319 printk(KERN_ERR "can not alloc irq_desc\n");
320 BUG_ON(1);
321 }
322 init_one_irq_desc(irq, desc, node);
323
1f5a5b87 324 irq_insert_desc(irq, desc);
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325
326out_unlock:
327 raw_spin_unlock_irqrestore(&sparse_irq_lock, flags);
328
329 return desc;
330}
331
332#else /* !CONFIG_SPARSE_IRQ */
333
334struct irq_desc irq_desc[NR_IRQS] __cacheline_aligned_in_smp = {
335 [0 ... NR_IRQS-1] = {
1318a481 336 .status = IRQ_DEFAULT_INIT_FLAGS,
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337 .handle_irq = handle_bad_irq,
338 .depth = 1,
339 .lock = __RAW_SPIN_LOCK_UNLOCKED(irq_desc->lock),
340 }
341};
342
343static unsigned int kstat_irqs_all[NR_IRQS][NR_CPUS];
344int __init early_irq_init(void)
345{
346 struct irq_desc *desc;
347 int count;
348 int i;
349
350 init_irq_default_affinity();
351
352 printk(KERN_INFO "NR_IRQS:%d\n", NR_IRQS);
353
354 desc = irq_desc;
355 count = ARRAY_SIZE(irq_desc);
356
357 for (i = 0; i < count; i++) {
358 desc[i].irq_data.irq = i;
359 desc[i].irq_data.chip = &no_irq_chip;
360 alloc_desc_masks(&desc[i], 0, true);
361 init_desc_masks(&desc[i]);
362 desc[i].kstat_irqs = kstat_irqs_all[i];
154cd387 363 lockdep_set_class(&desc[i].lock, &irq_desc_lock_class);
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364 }
365 return arch_early_irq_init();
366}
367
368struct irq_desc *irq_to_desc(unsigned int irq)
369{
370 return (irq < NR_IRQS) ? irq_desc + irq : NULL;
371}
372
373struct irq_desc *irq_to_desc_alloc_node(unsigned int irq, int node)
374{
375 return irq_to_desc(irq);
376}
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377
378#ifdef CONFIG_SMP
379static inline int desc_node(struct irq_desc *desc)
380{
381 return desc->irq_data.node;
382}
383#else
384static inline int desc_node(struct irq_desc *desc) { return 0; }
385#endif
386
387static void free_desc(unsigned int irq)
388{
389 struct irq_desc *desc = irq_to_desc(irq);
390 unsigned long flags;
391
392 raw_spin_lock_irqsave(&desc->lock, flags);
393 desc_set_defaults(irq, desc, desc_node(desc));
394 raw_spin_unlock_irqrestore(&desc->lock, flags);
395}
396
397static inline int alloc_descs(unsigned int start, unsigned int cnt, int node)
398{
399 return start;
400}
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401#endif /* !CONFIG_SPARSE_IRQ */
402
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403/* Dynamic interrupt handling */
404
405/**
406 * irq_free_descs - free irq descriptors
407 * @from: Start of descriptor range
408 * @cnt: Number of consecutive irqs to free
409 */
410void irq_free_descs(unsigned int from, unsigned int cnt)
411{
412 unsigned long flags;
413 int i;
414
415 if (from >= nr_irqs || (from + cnt) > nr_irqs)
416 return;
417
418 for (i = 0; i < cnt; i++)
419 free_desc(from + i);
420
421 raw_spin_lock_irqsave(&sparse_irq_lock, flags);
422 bitmap_clear(allocated_irqs, from, cnt);
423 raw_spin_unlock_irqrestore(&sparse_irq_lock, flags);
424}
425
426/**
427 * irq_alloc_descs - allocate and initialize a range of irq descriptors
428 * @irq: Allocate for specific irq number if irq >= 0
429 * @from: Start the search from this irq number
430 * @cnt: Number of consecutive irqs to allocate.
431 * @node: Preferred node on which the irq descriptor should be allocated
432 *
433 * Returns the first irq number or error code
434 */
435int __ref
436irq_alloc_descs(int irq, unsigned int from, unsigned int cnt, int node)
437{
438 unsigned long flags;
439 int start, ret;
440
441 if (!cnt)
442 return -EINVAL;
443
444 raw_spin_lock_irqsave(&sparse_irq_lock, flags);
445
446 start = bitmap_find_next_zero_area(allocated_irqs, nr_irqs, from, cnt, 0);
447 ret = -EEXIST;
448 if (irq >=0 && start != irq)
449 goto err;
450
451 ret = -ENOMEM;
452 if (start >= nr_irqs)
453 goto err;
454
455 bitmap_set(allocated_irqs, start, cnt);
456 raw_spin_unlock_irqrestore(&sparse_irq_lock, flags);
457 return alloc_descs(start, cnt, node);
458
459err:
460 raw_spin_unlock_irqrestore(&sparse_irq_lock, flags);
461 return ret;
462}
463
464/* Statistics access */
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465void clear_kstat_irqs(struct irq_desc *desc)
466{
467 memset(desc->kstat_irqs, 0, nr_cpu_ids * sizeof(*(desc->kstat_irqs)));
468}
469
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470unsigned int kstat_irqs_cpu(unsigned int irq, int cpu)
471{
472 struct irq_desc *desc = irq_to_desc(irq);
473 return desc ? desc->kstat_irqs[cpu] : 0;
474}