summaryrefslogtreecommitdiff
path: root/kernel/irq/irqdesc.c
blob: bb48a5c1964e22bbccd75196046ae70e05d5355e (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
/*
 * Copyright (C) 1992, 1998-2006 Linus Torvalds, Ingo Molnar
 * Copyright (C) 2005-2006, Thomas Gleixner, Russell King
 *
 * This file contains the interrupt descriptor management code
 *
 * Detailed information is available in Documentation/DocBook/genericirq
 *
 */
#include <linux/irq.h>
#include <linux/slab.h>
#include <linux/export.h>
#include <linux/interrupt.h>
#include <linux/kernel_stat.h>
#include <linux/radix-tree.h>
#include <linux/bitmap.h>
#include <linux/irqdomain.h>

#include "internals.h"

/*
 * lockdep: we want to handle all irq_desc locks as a single lock-class:
 */
static struct lock_class_key irq_desc_lock_class;

#if defined(CONFIG_SMP)
static void __init init_irq_default_affinity(void)
{
	alloc_cpumask_var(&irq_default_affinity, GFP_NOWAIT);
	cpumask_setall(irq_default_affinity);
}
#else
static void __init init_irq_default_affinity(void)
{
}
#endif

#ifdef CONFIG_SMP
static int alloc_masks(struct irq_desc *desc, gfp_t gfp, int node)
{
	if (!zalloc_cpumask_var_node(&desc->irq_common_data.affinity,
				     gfp, node))
		return -ENOMEM;

#ifdef CONFIG_GENERIC_PENDING_IRQ
	if (!zalloc_cpumask_var_node(&desc->pending_mask, gfp, node)) {
		free_cpumask_var(desc->irq_common_data.affinity);
		return -ENOMEM;
	}
#endif
	return 0;
}

static void desc_smp_init(struct irq_desc *desc, int node)
{
	cpumask_copy(desc->irq_common_data.affinity, irq_default_affinity);
#ifdef CONFIG_GENERIC_PENDING_IRQ
	cpumask_clear(desc->pending_mask);
#endif
#ifdef CONFIG_NUMA
	desc->irq_common_data.node = node;
#endif
}

#else
static inline int
alloc_masks(struct irq_desc *desc, gfp_t gfp, int node) { return 0; }
static inline void desc_smp_init(struct irq_desc *desc, int node) { }
#endif

static void desc_set_defaults(unsigned int irq, struct irq_desc *desc, int node,
		struct module *owner)
{
	int cpu;

	desc->irq_common_data.handler_data = NULL;

	desc->irq_data.common = &desc->irq_common_data;
	desc->irq_data.irq = irq;
	desc->irq_data.chip = &no_irq_chip;
	desc->irq_data.chip_data = NULL;
	desc->irq_data.msi_desc = NULL;
	irq_settings_clr_and_set(desc, ~0, _IRQ_DEFAULT_INIT_FLAGS);
	irqd_set(&desc->irq_data, IRQD_IRQ_DISABLED);
	desc->handle_irq = handle_bad_irq;
	desc->depth = 1;
	desc->irq_count = 0;
	desc->irqs_unhandled = 0;
	desc->name = NULL;
	desc->owner = owner;
	for_each_possible_cpu(cpu)
		*per_cpu_ptr(desc->kstat_irqs, cpu) = 0;
	desc_smp_init(desc, node);
}

int nr_irqs = NR_IRQS;
EXPORT_SYMBOL_GPL(nr_irqs);

static DEFINE_MUTEX(sparse_irq_lock);
static DECLARE_BITMAP(allocated_irqs, IRQ_BITMAP_BITS);

#ifdef CONFIG_SPARSE_IRQ

static RADIX_TREE(irq_desc_tree, GFP_KERNEL);

static void irq_insert_desc(unsigned int irq, struct irq_desc *desc)
{
	radix_tree_insert(&irq_desc_tree, irq, desc);
}

struct irq_desc *irq_to_desc(unsigned int irq)
{
	return radix_tree_lookup(&irq_desc_tree, irq);
}
EXPORT_SYMBOL(irq_to_desc);

static void delete_irq_desc(unsigned int irq)
{
	radix_tree_delete(&irq_desc_tree, irq);
}

#ifdef CONFIG_SMP
static void free_masks(struct irq_desc *desc)
{
#ifdef CONFIG_GENERIC_PENDING_IRQ
	free_cpumask_var(desc->pending_mask);
#endif
	free_cpumask_var(desc->irq_common_data.affinity);
}
#else
static inline void free_masks(struct irq_desc *desc) { }
#endif

void irq_lock_sparse(void)
{
	mutex_lock(&sparse_irq_lock);
}

void irq_unlock_sparse(void)
{
	mutex_unlock(&sparse_irq_lock);
}

static struct irq_desc *alloc_desc(int irq, int node, struct module *owner)
{
	struct irq_desc *desc;
	gfp_t gfp = GFP_KERNEL;

	desc = kzalloc_node(sizeof(*desc), gfp, node);
	if (!desc)
		return NULL;
	/* allocate based on nr_cpu_ids */
	desc->kstat_irqs = alloc_percpu(unsigned int);
	if (!desc->kstat_irqs)
		goto err_desc;

	if (alloc_masks(desc, gfp, node))
		goto err_kstat;

	raw_spin_lock_init(&desc->lock);
	lockdep_set_class(&desc->lock, &irq_desc_lock_class);

	desc_set_defaults(irq, desc, node, owner);

	return desc;

err_kstat:
	free_percpu(desc->kstat_irqs);
err_desc:
	kfree(desc);
	return NULL;
}

static void free_desc(unsigned int irq)
{
	struct irq_desc *desc = irq_to_desc(irq);

	unregister_irq_proc(irq, desc);

	/*
	 * sparse_irq_lock protects also show_interrupts() and
	 * kstat_irq_usr(). Once we deleted the descriptor from the
	 * sparse tree we can free it. Access in proc will fail to
	 * lookup the descriptor.
	 */
	mutex_lock(&sparse_irq_lock);
	delete_irq_desc(irq);
	mutex_unlock(&sparse_irq_lock);

	free_masks(desc);
	free_percpu(desc->kstat_irqs);
	kfree(desc);
}

static int alloc_descs(unsigned int start, unsigned int cnt, int node,
		       struct module *owner)
{
	struct irq_desc *desc;
	int i;

	for (i = 0; i < cnt; i++) {
		desc = alloc_desc(start + i, node, owner);
		if (!desc)
			goto err;
		mutex_lock(&sparse_irq_lock);
		irq_insert_desc(start + i, desc);
		mutex_unlock(&sparse_irq_lock);
	}
	return start;

err:
	for (i--; i >= 0; i--)
		free_desc(start + i);

	mutex_lock(&sparse_irq_lock);
	bitmap_clear(allocated_irqs, start, cnt);
	mutex_unlock(&sparse_irq_lock);
	return -ENOMEM;
}

static int irq_expand_nr_irqs(unsigned int nr)
{
	if (nr > IRQ_BITMAP_BITS)
		return -ENOMEM;
	nr_irqs = nr;
	return 0;
}

int __init early_irq_init(void)
{
	int i, initcnt, node = first_online_node;
	struct irq_desc *desc;

	init_irq_default_affinity();

	/* Let arch update nr_irqs and return the nr of preallocated irqs */
	initcnt = arch_probe_nr_irqs();
	printk(KERN_INFO "NR_IRQS:%d nr_irqs:%d %d\n", NR_IRQS, nr_irqs, initcnt);

	if (WARN_ON(nr_irqs > IRQ_BITMAP_BITS))
		nr_irqs = IRQ_BITMAP_BITS;

	if (WARN_ON(initcnt > IRQ_BITMAP_BITS))
		initcnt = IRQ_BITMAP_BITS;

	if (initcnt > nr_irqs)
		nr_irqs = initcnt;

	for (i = 0; i < initcnt; i++) {
		desc = alloc_desc(i, node, NULL);
		set_bit(i, allocated_irqs);
		irq_insert_desc(i, desc);
	}
	return arch_early_irq_init();
}

#else /* !CONFIG_SPARSE_IRQ */

struct irq_desc irq_desc[NR_IRQS] __cacheline_aligned_in_smp = {
	[0 ... NR_IRQS-1] = {
		.handle_irq	= handle_bad_irq,
		.depth		= 1,
		.lock		= __RAW_SPIN_LOCK_UNLOCKED(irq_desc->lock),
	}
};

int __init early_irq_init(void)
{
	int count, i, node = first_online_node;
	struct irq_desc *desc;

	init_irq_default_affinity();

	printk(KERN_INFO "NR_IRQS:%d\n", NR_IRQS);

	desc = irq_desc;
	count = ARRAY_SIZE(irq_desc);

	for (i = 0; i < count; i++) {
		desc[i].kstat_irqs = alloc_percpu(unsigned int);
		alloc_masks(&desc[i], GFP_KERNEL, node);
		raw_spin_lock_init(&desc[i].lock);
		lockdep_set_class(&desc[i].lock, &irq_desc_lock_class);
		desc_set_defaults(i, &desc[i], node, NULL);
	}
	return arch_early_irq_init();
}

struct irq_desc *irq_to_desc(unsigned int irq)
{
	return (irq < NR_IRQS) ? irq_desc + irq : NULL;
}
EXPORT_SYMBOL(irq_to_desc);

static void free_desc(unsigned int irq)
{
	struct irq_desc *desc = irq_to_desc(irq);
	unsigned long flags;

	raw_spin_lock_irqsave(&desc->lock, flags);
	desc_set_defaults(irq, desc, irq_desc_get_node(desc), NULL);
	raw_spin_unlock_irqrestore(&desc->lock, flags);
}

static inline int alloc_descs(unsigned int start, unsigned int cnt, int node,
			      struct module *owner)
{
	u32 i;

	for (i = 0; i < cnt; i++) {
		struct irq_desc *desc = irq_to_desc(start + i);

		desc->owner = owner;
	}
	return start;
}

static int irq_expand_nr_irqs(unsigned int nr)
{
	return -ENOMEM;
}

void irq_mark_irq(unsigned int irq)
{
	mutex_lock(&sparse_irq_lock);
	bitmap_set(allocated_irqs, irq, 1);
	mutex_unlock(&sparse_irq_lock);
}

#ifdef CONFIG_GENERIC_IRQ_LEGACY
void irq_init_desc(unsigned int irq)
{
	free_desc(irq);
}
#endif

#endif /* !CONFIG_SPARSE_IRQ */

/**
 * generic_handle_irq - Invoke the handler for a particular irq
 * @irq:	The irq number to handle
 *
 */
int generic_handle_irq(unsigned int irq)
{
	struct irq_desc *desc = irq_to_desc(irq);

	if (!desc)
		return -EINVAL;
	generic_handle_irq_desc(irq, desc);
	return 0;
}
EXPORT_SYMBOL_GPL(generic_handle_irq);

#ifdef CONFIG_HANDLE_DOMAIN_IRQ
/**
 * __handle_domain_irq - Invoke the handler for a HW irq belonging to a domain
 * @domain:	The domain where to perform the lookup
 * @hwirq:	The HW irq number to convert to a logical one
 * @lookup:	Whether to perform the domain lookup or not
 * @regs:	Register file coming from the low-level handling code
 *
 * Returns:	0 on success, or -EINVAL if conversion has failed
 */
int __handle_domain_irq(struct irq_domain *domain, unsigned int hwirq,
			bool lookup, struct pt_regs *regs)
{
	struct pt_regs *old_regs = set_irq_regs(regs);
	unsigned int irq = hwirq;
	int ret = 0;

	irq_enter();

#ifdef CONFIG_IRQ_DOMAIN
	if (lookup)
		irq = irq_find_mapping(domain, hwirq);
#endif

	/*
	 * Some hardware gives randomly wrong interrupts.  Rather
	 * than crashing, do something sensible.
	 */
	if (unlikely(!irq || irq >= nr_irqs)) {
		ack_bad_irq(irq);
		ret = -EINVAL;
	} else {
		generic_handle_irq(irq);
	}

	irq_exit();
	set_irq_regs(old_regs);
	return ret;
}
#endif

/* Dynamic interrupt handling */

/**
 * irq_free_descs - free irq descriptors
 * @from:	Start of descriptor range
 * @cnt:	Number of consecutive irqs to free
 */
void irq_free_descs(unsigned int from, unsigned int cnt)
{
	int i;

	if (from >= nr_irqs || (from + cnt) > nr_irqs)
		return;

	for (i = 0; i < cnt; i++)
		free_desc(from + i);

	mutex_lock(&sparse_irq_lock);
	bitmap_clear(allocated_irqs, from, cnt);
	mutex_unlock(&sparse_irq_lock);
}
EXPORT_SYMBOL_GPL(irq_free_descs);

/**
 * irq_alloc_descs - allocate and initialize a range of irq descriptors
 * @irq:	Allocate for specific irq number if irq >= 0
 * @from:	Start the search from this irq number
 * @cnt:	Number of consecutive irqs to allocate.
 * @node:	Preferred node on which the irq descriptor should be allocated
 * @owner:	Owning module (can be NULL)
 *
 * Returns the first irq number or error code
 */
int __ref
__irq_alloc_descs(int irq, unsigned int from, unsigned int cnt, int node,
		  struct module *owner)
{
	int start, ret;

	if (!cnt)
		return -EINVAL;

	if (irq >= 0) {
		if (from > irq)
			return -EINVAL;
		from = irq;
	} else {
		/*
		 * For interrupts which are freely allocated the
		 * architecture can force a lower bound to the @from
		 * argument. x86 uses this to exclude the GSI space.
		 */
		from = arch_dynirq_lower_bound(from);
	}

	mutex_lock(&sparse_irq_lock);

	start = bitmap_find_next_zero_area(allocated_irqs, IRQ_BITMAP_BITS,
					   from, cnt, 0);
	ret = -EEXIST;
	if (irq >=0 && start != irq)
		goto err;

	if (start + cnt > nr_irqs) {
		ret = irq_expand_nr_irqs(start + cnt);
		if (ret)
			goto err;
	}

	bitmap_set(allocated_irqs, start, cnt);
	mutex_unlock(&sparse_irq_lock);
	return alloc_descs(start, cnt, node, owner);

err:
	mutex_unlock(&sparse_irq_lock);
	return ret;
}
EXPORT_SYMBOL_GPL(__irq_alloc_descs);

#ifdef CONFIG_GENERIC_IRQ_LEGACY_ALLOC_HWIRQ
/**
 * irq_alloc_hwirqs - Allocate an irq descriptor and initialize the hardware
 * @cnt:	number of interrupts to allocate
 * @node:	node on which to allocate
 *
 * Returns an interrupt number > 0 or 0, if the allocation fails.
 */
unsigned int irq_alloc_hwirqs(int cnt, int node)
{
	int i, irq = __irq_alloc_descs(-1, 0, cnt, node, NULL);

	if (irq < 0)
		return 0;

	for (i = irq; cnt > 0; i++, cnt--) {
		if (arch_setup_hwirq(i, node))
			goto err;
		irq_clear_status_flags(i, _IRQ_NOREQUEST);
	}
	return irq;

err:
	for (i--; i >= irq; i--) {
		irq_set_status_flags(i, _IRQ_NOREQUEST | _IRQ_NOPROBE);
		arch_teardown_hwirq(i);
	}
	irq_free_descs(irq, cnt);
	return 0;
}
EXPORT_SYMBOL_GPL(irq_alloc_hwirqs);

/**
 * irq_free_hwirqs - Free irq descriptor and cleanup the hardware
 * @from:	Free from irq number
 * @cnt:	number of interrupts to free
 *
 */
void irq_free_hwirqs(unsigned int from, int cnt)
{
	int i, j;

	for (i = from, j = cnt; j > 0; i++, j--) {
		irq_set_status_flags(i, _IRQ_NOREQUEST | _IRQ_NOPROBE);
		arch_teardown_hwirq(i);
	}
	irq_free_descs(from, cnt);
}
EXPORT_SYMBOL_GPL(irq_free_hwirqs);
#endif

/**
 * irq_get_next_irq - get next allocated irq number
 * @offset:	where to start the search
 *
 * Returns next irq number after offset or nr_irqs if none is found.
 */
unsigned int irq_get_next_irq(unsigned int offset)
{
	return find_next_bit(allocated_irqs, nr_irqs, offset);
}

struct irq_desc *
__irq_get_desc_lock(unsigned int irq, unsigned long *flags, bool bus,
		    unsigned int check)
{
	struct irq_desc *desc = irq_to_desc(irq);

	if (desc) {
		if (check & _IRQ_DESC_CHECK) {
			if ((check & _IRQ_DESC_PERCPU) &&
			    !irq_settings_is_per_cpu_devid(desc))
				return NULL;

			if (!(check & _IRQ_DESC_PERCPU) &&
			    irq_settings_is_per_cpu_devid(desc))
				return NULL;
		}

		if (bus)
			chip_bus_lock(desc);
		raw_spin_lock_irqsave(&desc->lock, *flags);
	}
	return desc;
}

void __irq_put_desc_unlock(struct irq_desc *desc, unsigned long flags, bool bus)
{
	raw_spin_unlock_irqrestore(&desc->lock, flags);
	if (bus)
		chip_bus_sync_unlock(desc);
}

int irq_set_percpu_devid(unsigned int irq)
{
	struct irq_desc *desc = irq_to_desc(irq);

	if (!desc)
		return -EINVAL;

	if (desc->percpu_enabled)
		return -EINVAL;

	desc->percpu_enabled = kzalloc(sizeof(*desc->percpu_enabled), GFP_KERNEL);

	if (!desc->percpu_enabled)
		return -ENOMEM;

	irq_set_percpu_devid_flags(irq);
	return 0;
}

void kstat_incr_irq_this_cpu(unsigned int irq)
{
	kstat_incr_irqs_this_cpu(irq_to_desc(irq));
}

/**
 * kstat_irqs_cpu - Get the statistics for an interrupt on a cpu
 * @irq:	The interrupt number
 * @cpu:	The cpu number
 *
 * Returns the sum of interrupt counts on @cpu since boot for
 * @irq. The caller must ensure that the interrupt is not removed
 * concurrently.
 */
unsigned int kstat_irqs_cpu(unsigned int irq, int cpu)
{
	struct irq_desc *desc = irq_to_desc(irq);

	return desc && desc->kstat_irqs ?
			*per_cpu_ptr(desc->kstat_irqs, cpu) : 0;
}

/**
 * kstat_irqs - Get the statistics for an interrupt
 * @irq:	The interrupt number
 *
 * Returns the sum of interrupt counts on all cpus since boot for
 * @irq. The caller must ensure that the interrupt is not removed
 * concurrently.
 */
unsigned int kstat_irqs(unsigned int irq)
{
	struct irq_desc *desc = irq_to_desc(irq);
	int cpu;
	unsigned int sum = 0;

	if (!desc || !desc->kstat_irqs)
		return 0;
	for_each_possible_cpu(cpu)
		sum += *per_cpu_ptr(desc->kstat_irqs, cpu);
	return sum;
}

/**
 * kstat_irqs_usr - Get the statistics for an interrupt
 * @irq:	The interrupt number
 *
 * Returns the sum of interrupt counts on all cpus since boot for
 * @irq. Contrary to kstat_irqs() this can be called from any
 * preemptible context. It's protected against concurrent removal of
 * an interrupt descriptor when sparse irqs are enabled.
 */
unsigned int kstat_irqs_usr(unsigned int irq)
{
	unsigned int sum;

	irq_lock_sparse();
	sum = kstat_irqs(irq);
	irq_unlock_sparse();
	return sum;
}