summaryrefslogtreecommitdiffstats
path: root/kernel/irq/irqdesc.c
blob: 02b446a21ce64d1b45edb6bf009bfbd36100bc59 (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
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
// SPDX-License-Identifier: GPL-2.0
/*
 * 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/core-api/genericirq.rst
 *
 */
#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 <linux/sysfs.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 int __init irq_affinity_setup(char *str)
{
	alloc_bootmem_cpumask_var(&irq_default_affinity);
	cpulist_parse(str, irq_default_affinity);
	/*
	 * Set at least the boot cpu. We don't want to end up with
	 * bugreports caused by random comandline masks
	 */
	cpumask_set_cpu(smp_processor_id(), irq_default_affinity);
	return 1;
}
__setup("irqaffinity=", irq_affinity_setup);

static void __init init_irq_default_affinity(void)
{
	if (!cpumask_available(irq_default_affinity))
		zalloc_cpumask_var(&irq_default_affinity, GFP_NOWAIT);
	if (cpumask_empty(irq_default_affinity))
		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, int node)
{
	if (!zalloc_cpumask_var_node(&desc->irq_common_data.affinity,
				     GFP_KERNEL, node))
		return -ENOMEM;

#ifdef CONFIG_GENERIC_IRQ_EFFECTIVE_AFF_MASK
	if (!zalloc_cpumask_var_node(&desc->irq_common_data.effective_affinity,
				     GFP_KERNEL, node)) {
		free_cpumask_var(desc->irq_common_data.affinity);
		return -ENOMEM;
	}
#endif

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

static void desc_smp_init(struct irq_desc *desc, int node,
			  const struct cpumask *affinity)
{
	if (!affinity)
		affinity = irq_default_affinity;
	cpumask_copy(desc->irq_common_data.affinity, 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, int node) { return 0; }
static inline void
desc_smp_init(struct irq_desc *desc, int node, const struct cpumask *affinity) { }
#endif

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

	desc->irq_common_data.handler_data = NULL;
	desc->irq_common_data.msi_desc = 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;
	irq_settings_clr_and_set(desc, ~0, _IRQ_DEFAULT_INIT_FLAGS);
	irqd_set(&desc->irq_data, IRQD_IRQ_DISABLED);
	irqd_set(&desc->irq_data, IRQD_IRQ_MASKED);
	desc->handle_irq = handle_bad_irq;
	desc->depth = 1;
	desc->irq_count = 0;
	desc->irqs_unhandled = 0;
	desc->tot_count = 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, affinity);
}

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 void irq_kobj_release(struct kobject *kobj);

#ifdef CONFIG_SYSFS
static struct kobject *irq_kobj_base;

#define IRQ_ATTR_RO(_name) \
static struct kobj_attribute _name##_attr = __ATTR_RO(_name)

static ssize_t per_cpu_count_show(struct kobject *kobj,
				  struct kobj_attribute *attr, char *buf)
{
	struct irq_desc *desc = container_of(kobj, struct irq_desc, kobj);
	int cpu, irq = desc->irq_data.irq;
	ssize_t ret = 0;
	char *p = "";

	for_each_possible_cpu(cpu) {
		unsigned int c = kstat_irqs_cpu(irq, cpu);

		ret += scnprintf(buf + ret, PAGE_SIZE - ret, "%s%u", p, c);
		p = ",";
	}

	ret += scnprintf(buf + ret, PAGE_SIZE - ret, "\n");
	return ret;
}
IRQ_ATTR_RO(per_cpu_count);

static ssize_t chip_name_show(struct kobject *kobj,
			      struct kobj_attribute *attr, char *buf)
{
	struct irq_desc *desc = container_of(kobj, struct irq_desc, kobj);
	ssize_t ret = 0;

	raw_spin_lock_irq(&desc->lock);
	if (desc->irq_data.chip && desc->irq_data.chip->name) {
		ret = scnprintf(buf, PAGE_SIZE, "%s\n",
				desc->irq_data.chip->name);
	}
	raw_spin_unlock_irq(&desc->lock);

	return ret;
}
IRQ_ATTR_RO(chip_name);

static ssize_t hwirq_show(struct kobject *kobj,
			  struct kobj_attribute *attr, char *buf)
{
	struct irq_desc *desc = container_of(kobj, struct irq_desc, kobj);
	ssize_t ret = 0;

	raw_spin_lock_irq(&desc->lock);
	if (desc->irq_data.domain)
		ret = sprintf(buf, "%d\n", (int)desc->irq_data.hwirq);
	raw_spin_unlock_irq(&desc->lock);

	return ret;
}
IRQ_ATTR_RO(hwirq);

static ssize_t type_show(struct kobject *kobj,
			 struct kobj_attribute *attr, char *buf)
{
	struct irq_desc *desc = container_of(kobj, struct irq_desc, kobj);
	ssize_t ret = 0;

	raw_spin_lock_irq(&desc->lock);
	ret = sprintf(buf, "%s\n",
		      irqd_is_level_type(&desc->irq_data) ? "level" : "edge");
	raw_spin_unlock_irq(&desc->lock);

	return ret;

}
IRQ_ATTR_RO(type);

static ssize_t wakeup_show(struct kobject *kobj,
			   struct kobj_attribute *attr, char *buf)
{
	struct irq_desc *desc = container_of(kobj, struct irq_desc, kobj);
	ssize_t ret = 0;

	raw_spin_lock_irq(&desc->lock);
	ret = sprintf(buf, "%s\n",
		      irqd_is_wakeup_set(&desc->irq_data) ? "enabled" : "disabled");
	raw_spin_unlock_irq(&desc->lock);

	return ret;

}
IRQ_ATTR_RO(wakeup);

static ssize_t name_show(struct kobject *kobj,
			 struct kobj_attribute *attr, char *buf)
{
	struct irq_desc *desc = container_of(kobj, struct irq_desc, kobj);
	ssize_t ret = 0;

	raw_spin_lock_irq(&desc->lock);
	if (desc->name)
		ret = scnprintf(buf, PAGE_SIZE, "%s\n", desc->name);
	raw_spin_unlock_irq(&desc->lock);

	return ret;
}
IRQ_ATTR_RO(name);

static ssize_t actions_show(struct kobject *kobj,
			    struct kobj_attribute *attr, char *buf)
{
	struct irq_desc *desc = container_of(kobj, struct irq_desc, kobj);
	struct irqaction *action;
	ssize_t ret = 0;
	char *p = "";

	raw_spin_lock_irq(&desc->lock);
	for (action = desc->action; action != NULL; action = action->next) {
		ret += scnprintf(buf + ret, PAGE_SIZE - ret, "%s%s",
				 p, action->name);
		p = ",";
	}
	raw_spin_unlock_irq(&desc->lock);

	if (ret)
		ret += scnprintf(buf + ret, PAGE_SIZE - ret, "\n");

	return ret;
}
IRQ_ATTR_RO(actions);

static struct attribute *irq_attrs[] = {
	&per_cpu_count_attr.attr,
	&chip_name_attr.attr,
	&hwirq_attr.attr,
	&type_attr.attr,
	&wakeup_attr.attr,
	&name_attr.attr,
	&actions_attr.attr,
	NULL
};
ATTRIBUTE_GROUPS(irq);

static struct kobj_type irq_kobj_type = {
	.release	= irq_kobj_release,
	.sysfs_ops	= &kobj_sysfs_ops,
	.default_groups = irq_groups,
};

static void irq_sysfs_add(int irq, struct irq_desc *desc)
{
	if (irq_kobj_base) {
		/*
		 * Continue even in case of failure as this is nothing
		 * crucial.
		 */
		if (kobject_add(&desc->kobj, irq_kobj_base, "%d", irq))
			pr_warn("Failed to add kobject for irq %d\n", irq);
	}
}

static void irq_sysfs_del(struct irq_desc *desc)
{
	/*
	 * If irq_sysfs_init() has not yet been invoked (early boot), then
	 * irq_kobj_base is NULL and the descriptor was never added.
	 * kobject_del() complains about a object with no parent, so make
	 * it conditional.
	 */
	if (irq_kobj_base)
		kobject_del(&desc->kobj);
}

static int __init irq_sysfs_init(void)
{
	struct irq_desc *desc;
	int irq;

	/* Prevent concurrent irq alloc/free */
	irq_lock_sparse();

	irq_kobj_base = kobject_create_and_add("irq", kernel_kobj);
	if (!irq_kobj_base) {
		irq_unlock_sparse();
		return -ENOMEM;
	}

	/* Add the already allocated interrupts */
	for_each_irq_desc(irq, desc)
		irq_sysfs_add(irq, desc);
	irq_unlock_sparse();

	return 0;
}
postcore_initcall(irq_sysfs_init);

#else /* !CONFIG_SYSFS */

static struct kobj_type irq_kobj_type = {
	.release	= irq_kobj_release,
};

static void irq_sysfs_add(int irq, struct irq_desc *desc) {}
static void irq_sysfs_del(struct irq_desc *desc) {}

#endif /* CONFIG_SYSFS */

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);
#ifdef CONFIG_GENERIC_IRQ_EFFECTIVE_AFF_MASK
	free_cpumask_var(desc->irq_common_data.effective_affinity);
#endif
}
#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, unsigned int flags,
				   const struct cpumask *affinity,
				   struct module *owner)
{
	struct irq_desc *desc;

	desc = kzalloc_node(sizeof(*desc), GFP_KERNEL, 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, node))
		goto err_kstat;

	raw_spin_lock_init(&desc->lock);
	lockdep_set_class(&desc->lock, &irq_desc_lock_class);
	mutex_init(&desc->request_mutex);
	init_rcu_head(&desc->rcu);

	desc_set_defaults(irq, desc, node, affinity, owner);
	irqd_set(&desc->irq_data, flags);
	kobject_init(&desc->kobj, &irq_kobj_type);

	return desc;

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

static void irq_kobj_release(struct kobject *kobj)
{
	struct irq_desc *desc = container_of(kobj, struct irq_desc, kobj);

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

static void delayed_free_desc(struct rcu_head *rhp)
{
	struct irq_desc *desc = container_of(rhp, struct irq_desc, rcu);

	kobject_put(&desc->kobj);
}

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

	irq_remove_debugfs_entry(desc);
	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.
	 *
	 * The sysfs entry must be serialized against a concurrent
	 * irq_sysfs_init() as well.
	 */
	irq_sysfs_del(desc);
	delete_irq_desc(irq);

	/*
	 * We free the descriptor, masks and stat fields via RCU. That
	 * allows demultiplex interrupts to do rcu based management of
	 * the child interrupts.
	 * This also allows us to use rcu in kstat_irqs_usr().
	 */
	call_rcu(&desc->rcu, delayed_free_desc);
}

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

	/* Validate affinity mask(s) */
	if (affinity) {
		for (i = 0; i < cnt; i++) {
			if (cpumask_empty(&affinity[i].mask))
				return -EINVAL;
		}
	}

	for (i = 0; i < cnt; i++) {
		const struct cpumask *mask = NULL;
		unsigned int flags = 0;

		if (affinity) {
			if (affinity->is_managed) {
				flags = IRQD_AFFINITY_MANAGED |
					IRQD_MANAGED_SHUTDOWN;
			}
			mask = &affinity->mask;
			node = cpu_to_node(cpumask_first(mask));
			affinity++;
		}

		desc = alloc_desc(start + i, node, flags, mask, owner);
		if (!desc)
			goto err;
		irq_insert_desc(start + i, desc);
		irq_sysfs_add(start + i, desc);
		irq_add_debugfs_entry(start + i, desc);
	}
	bitmap_set(allocated_irqs, start, cnt);
	return start;

err:
	for (i--; i >= 0; i--)
		free_desc(start + i);
	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, preallocated irqs: %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, 0, NULL, 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], node);
		raw_spin_lock_init(&desc[i].lock);
		lockdep_set_class(&desc[i].lock, &irq_desc_lock_class);
		mutex_init(&desc[i].request_mutex);
		desc_set_defaults(i, &desc[i], node, NULL, 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, NULL);
	raw_spin_unlock_irqrestore(&desc->lock, flags);
}

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

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

		desc->owner = owner;
	}
	bitmap_set(allocated_irqs, start, cnt);
	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);
	struct irq_data *data;

	if (!desc)
		return -EINVAL;

	data = irq_desc_get_irq_data(desc);
	if (WARN_ON_ONCE(!in_irq() && handle_enforce_irqctx(data)))
		return -EPERM;

	generic_handle_irq_desc(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;
}

#ifdef CONFIG_IRQ_DOMAIN
/**
 * handle_domain_nmi - 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
 * @regs:	Register file coming from the low-level handling code
 *
 *		This function must be called from an NMI context.
 *
 * Returns:	0 on success, or -EINVAL if conversion has failed
 */
int handle_domain_nmi(struct irq_domain *domain, unsigned int hwirq,
		      struct pt_regs *regs)
{
	struct pt_regs *old_regs = set_irq_regs(regs);
	unsigned int irq;
	int ret = 0;

	/*
	 * NMI context needs to be setup earlier in order to deal with tracing.
	 */
	WARN_ON(!in_nmi());

	irq = irq_find_mapping(domain, hwirq);

	/*
	 * ack_bad_irq is not NMI-safe, just report
	 * an invalid interrupt.
	 */
	if (likely(irq))
		generic_handle_irq(irq);
	else
		ret = -EINVAL;

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

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

	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)
 * @affinity:	Optional pointer to an affinity mask array of size @cnt which
 *		hints where the irq descriptors should be allocated and which
 *		default affinities to use
 *
 * 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, const struct irq_affinity_desc *affinity)
{
	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 unlock;

	if (start + cnt > nr_irqs) {
		ret = irq_expand_nr_irqs(start + cnt);
		if (ret)
			goto unlock;
	}
	ret = alloc_descs(start, cnt, node, affinity, owner);
unlock:
	mutex_unlock(&sparse_irq_lock);
	return ret;
}
EXPORT_SYMBOL_GPL(__irq_alloc_descs);

/**
 * 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)
	__releases(&desc->lock)
{
	raw_spin_unlock_irqrestore(&desc->lock, flags);
	if (bus)
		chip_bus_sync_unlock(desc);
}

int irq_set_percpu_devid_partition(unsigned int irq,
				   const struct cpumask *affinity)
{
	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;

	if (affinity)
		desc->percpu_affinity = affinity;
	else
		desc->percpu_affinity = cpu_possible_mask;

	irq_set_percpu_devid_flags(irq);
	return 0;
}

int irq_set_percpu_devid(unsigned int irq)
{
	return irq_set_percpu_devid_partition(irq, NULL);
}

int irq_get_percpu_devid_partition(unsigned int irq, struct cpumask *affinity)
{
	struct irq_desc *desc = irq_to_desc(irq);

	if (!desc || !desc->percpu_enabled)
		return -EINVAL;

	if (affinity)
		cpumask_copy(affinity, desc->percpu_affinity);

	return 0;
}
EXPORT_SYMBOL_GPL(irq_get_percpu_devid_partition);

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;
}

static bool irq_is_nmi(struct irq_desc *desc)
{
	return desc->istate & IRQS_NMI;
}

/**
 * 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);
	unsigned int sum = 0;
	int cpu;

	if (!desc || !desc->kstat_irqs)
		return 0;
	if (!irq_settings_is_per_cpu_devid(desc) &&
	    !irq_settings_is_per_cpu(desc) &&
	    !irq_is_nmi(desc))
		return data_race(desc->tot_count);

	for_each_possible_cpu(cpu)
		sum += data_race(*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 context.
 * It uses rcu since a concurrent removal of an interrupt descriptor is
 * observing an rcu grace period before delayed_free_desc()/irq_kobj_release().
 */
unsigned int kstat_irqs_usr(unsigned int irq)
{
	unsigned int sum;

	rcu_read_lock();
	sum = kstat_irqs(irq);
	rcu_read_unlock();
	return sum;
}

#ifdef CONFIG_LOCKDEP
void __irq_set_lockdep_class(unsigned int irq, struct lock_class_key *lock_class,
			     struct lock_class_key *request_class)
{
	struct irq_desc *desc = irq_to_desc(irq);

	if (desc) {
		lockdep_set_class(&desc->lock, lock_class);
		lockdep_set_class(&desc->request_mutex, request_class);
	}
}
EXPORT_SYMBOL_GPL(__irq_set_lockdep_class);
#endif