aboutsummaryrefslogtreecommitdiff
path: root/kernel/irq/chip.c
blob: d5a3009da71aed6dd5f3a82895f2f21cecd656b6 (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
/*
 * linux/kernel/irq/chip.c
 *
 * Copyright (C) 1992, 1998-2006 Linus Torvalds, Ingo Molnar
 * Copyright (C) 2005-2006, Thomas Gleixner, Russell King
 *
 * This file contains the core interrupt handling code, for irq-chip
 * based architectures.
 *
 * Detailed information is available in Documentation/DocBook/genericirq
 */

#include <linux/irq.h>
#include <linux/msi.h>
#include <linux/module.h>
#include <linux/interrupt.h>
#include <linux/kernel_stat.h>

#include "internals.h"

/**
 *	irq_set_chip - set the irq chip for an irq
 *	@irq:	irq number
 *	@chip:	pointer to irq chip description structure
 */
int irq_set_chip(unsigned int irq, struct irq_chip *chip)
{
	unsigned long flags;
	struct irq_desc *desc = irq_get_desc_lock(irq, &flags);

	if (!desc)
		return -EINVAL;

	if (!chip)
		chip = &no_irq_chip;

	desc->irq_data.chip = chip;
	irq_put_desc_unlock(desc, flags);
	/*
	 * For !CONFIG_SPARSE_IRQ make the irq show up in
	 * allocated_irqs. For the CONFIG_SPARSE_IRQ case, it is
	 * already marked, and this call is harmless.
	 */
	irq_reserve_irq(irq);
	return 0;
}
EXPORT_SYMBOL(irq_set_chip);

/**
 *	irq_set_type - set the irq trigger type for an irq
 *	@irq:	irq number
 *	@type:	IRQ_TYPE_{LEVEL,EDGE}_* value - see include/linux/irq.h
 */
int irq_set_irq_type(unsigned int irq, unsigned int type)
{
	unsigned long flags;
	struct irq_desc *desc = irq_get_desc_buslock(irq, &flags);
	int ret = 0;

	if (!desc)
		return -EINVAL;

	type &= IRQ_TYPE_SENSE_MASK;
	if (type != IRQ_TYPE_NONE)
		ret = __irq_set_trigger(desc, irq, type);
	irq_put_desc_busunlock(desc, flags);
	return ret;
}
EXPORT_SYMBOL(irq_set_irq_type);

/**
 *	irq_set_handler_data - set irq handler data for an irq
 *	@irq:	Interrupt number
 *	@data:	Pointer to interrupt specific data
 *
 *	Set the hardware irq controller data for an irq
 */
int irq_set_handler_data(unsigned int irq, void *data)
{
	unsigned long flags;
	struct irq_desc *desc = irq_get_desc_lock(irq, &flags);

	if (!desc)
		return -EINVAL;
	desc->irq_data.handler_data = data;
	irq_put_desc_unlock(desc, flags);
	return 0;
}
EXPORT_SYMBOL(irq_set_handler_data);

/**
 *	irq_set_msi_desc - set MSI descriptor data for an irq
 *	@irq:	Interrupt number
 *	@entry:	Pointer to MSI descriptor data
 *
 *	Set the MSI descriptor entry for an irq
 */
int irq_set_msi_desc(unsigned int irq, struct msi_desc *entry)
{
	unsigned long flags;
	struct irq_desc *desc = irq_get_desc_lock(irq, &flags);

	if (!desc)
		return -EINVAL;
	desc->irq_data.msi_desc = entry;
	if (entry)
		entry->irq = irq;
	irq_put_desc_unlock(desc, flags);
	return 0;
}

/**
 *	irq_set_chip_data - set irq chip data for an irq
 *	@irq:	Interrupt number
 *	@data:	Pointer to chip specific data
 *
 *	Set the hardware irq chip data for an irq
 */
int irq_set_chip_data(unsigned int irq, void *data)
{
	unsigned long flags;
	struct irq_desc *desc = irq_get_desc_lock(irq, &flags);

	if (!desc)
		return -EINVAL;
	desc->irq_data.chip_data = data;
	irq_put_desc_unlock(desc, flags);
	return 0;
}
EXPORT_SYMBOL(irq_set_chip_data);

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

	return desc ? &desc->irq_data : NULL;
}
EXPORT_SYMBOL_GPL(irq_get_irq_data);

static void irq_state_clr_disabled(struct irq_desc *desc)
{
	irqd_clear(&desc->irq_data, IRQD_IRQ_DISABLED);
}

static void irq_state_set_disabled(struct irq_desc *desc)
{
	irqd_set(&desc->irq_data, IRQD_IRQ_DISABLED);
}

static void irq_state_clr_masked(struct irq_desc *desc)
{
	irqd_clear(&desc->irq_data, IRQD_IRQ_MASKED);
}

static void irq_state_set_masked(struct irq_desc *desc)
{
	irqd_set(&desc->irq_data, IRQD_IRQ_MASKED);
}

int irq_startup(struct irq_desc *desc)
{
	irq_state_clr_disabled(desc);
	desc->depth = 0;

	if (desc->irq_data.chip->irq_startup) {
		int ret = desc->irq_data.chip->irq_startup(&desc->irq_data);
		irq_state_clr_masked(desc);
		return ret;
	}

	irq_enable(desc);
	return 0;
}

void irq_shutdown(struct irq_desc *desc)
{
	irq_state_set_disabled(desc);
	desc->depth = 1;
	if (desc->irq_data.chip->irq_shutdown)
		desc->irq_data.chip->irq_shutdown(&desc->irq_data);
	if (desc->irq_data.chip->irq_disable)
		desc->irq_data.chip->irq_disable(&desc->irq_data);
	else
		desc->irq_data.chip->irq_mask(&desc->irq_data);
	irq_state_set_masked(desc);
}

void irq_enable(struct irq_desc *desc)
{
	irq_state_clr_disabled(desc);
	if (desc->irq_data.chip->irq_enable)
		desc->irq_data.chip->irq_enable(&desc->irq_data);
	else
		desc->irq_data.chip->irq_unmask(&desc->irq_data);
	irq_state_clr_masked(desc);
}

void irq_disable(struct irq_desc *desc)
{
	irq_state_set_disabled(desc);
	if (desc->irq_data.chip->irq_disable) {
		desc->irq_data.chip->irq_disable(&desc->irq_data);
		irq_state_set_masked(desc);
	}
}

static inline void mask_ack_irq(struct irq_desc *desc)
{
	if (desc->irq_data.chip->irq_mask_ack)
		desc->irq_data.chip->irq_mask_ack(&desc->irq_data);
	else {
		desc->irq_data.chip->irq_mask(&desc->irq_data);
		if (desc->irq_data.chip->irq_ack)
			desc->irq_data.chip->irq_ack(&desc->irq_data);
	}
	irq_state_set_masked(desc);
}

void mask_irq(struct irq_desc *desc)
{
	if (desc->irq_data.chip->irq_mask) {
		desc->irq_data.chip->irq_mask(&desc->irq_data);
		irq_state_set_masked(desc);
	}
}

void unmask_irq(struct irq_desc *desc)
{
	if (desc->irq_data.chip->irq_unmask) {
		desc->irq_data.chip->irq_unmask(&desc->irq_data);
		irq_state_clr_masked(desc);
	}
}

/*
 *	handle_nested_irq - Handle a nested irq from a irq thread
 *	@irq:	the interrupt number
 *
 *	Handle interrupts which are nested into a threaded interrupt
 *	handler. The handler function is called inside the calling
 *	threads context.
 */
void handle_nested_irq(unsigned int irq)
{
	struct irq_desc *desc = irq_to_desc(irq);
	struct irqaction *action;
	irqreturn_t action_ret;

	might_sleep();

	raw_spin_lock_irq(&desc->lock);

	kstat_incr_irqs_this_cpu(irq, desc);

	action = desc->action;
	if (unlikely(!action || irqd_irq_disabled(&desc->irq_data)))
		goto out_unlock;

	irqd_set(&desc->irq_data, IRQD_IRQ_INPROGRESS);
	raw_spin_unlock_irq(&desc->lock);

	action_ret = action->thread_fn(action->irq, action->dev_id);
	if (!noirqdebug)
		note_interrupt(irq, desc, action_ret);

	raw_spin_lock_irq(&desc->lock);
	irqd_clear(&desc->irq_data, IRQD_IRQ_INPROGRESS);

out_unlock:
	raw_spin_unlock_irq(&desc->lock);
}
EXPORT_SYMBOL_GPL(handle_nested_irq);

static bool irq_check_poll(struct irq_desc *desc)
{
	if (!(desc->istate & IRQS_POLL_INPROGRESS))
		return false;
	return irq_wait_for_poll(desc);
}

/**
 *	handle_simple_irq - Simple and software-decoded IRQs.
 *	@irq:	the interrupt number
 *	@desc:	the interrupt description structure for this irq
 *
 *	Simple interrupts are either sent from a demultiplexing interrupt
 *	handler or come from hardware, where no interrupt hardware control
 *	is necessary.
 *
 *	Note: The caller is expected to handle the ack, clear, mask and
 *	unmask issues if necessary.
 */
void
handle_simple_irq(unsigned int irq, struct irq_desc *desc)
{
	raw_spin_lock(&desc->lock);

	if (unlikely(irqd_irq_inprogress(&desc->irq_data)))
		if (!irq_check_poll(desc))
			goto out_unlock;

	desc->istate &= ~(IRQS_REPLAY | IRQS_WAITING);
	kstat_incr_irqs_this_cpu(irq, desc);

	if (unlikely(!desc->action || irqd_irq_disabled(&desc->irq_data)))
		goto out_unlock;

	handle_irq_event(desc);

out_unlock:
	raw_spin_unlock(&desc->lock);
}
EXPORT_SYMBOL_GPL(handle_simple_irq);

/**
 *	handle_level_irq - Level type irq handler
 *	@irq:	the interrupt number
 *	@desc:	the interrupt description structure for this irq
 *
 *	Level type interrupts are active as long as the hardware line has
 *	the active level. This may require to mask the interrupt and unmask
 *	it after the associated handler has acknowledged the device, so the
 *	interrupt line is back to inactive.
 */
void
handle_level_irq(unsigned int irq, struct irq_desc *desc)
{
	raw_spin_lock(&desc->lock);
	mask_ack_irq(desc);

	if (unlikely(irqd_irq_inprogress(&desc->irq_data)))
		if (!irq_check_poll(desc))
			goto out_unlock;

	desc->istate &= ~(IRQS_REPLAY | IRQS_WAITING);
	kstat_incr_irqs_this_cpu(irq, desc);

	/*
	 * If its disabled or no action available
	 * keep it masked and get out of here
	 */
	if (unlikely(!desc->action || irqd_irq_disabled(&desc->irq_data)))
		goto out_unlock;

	handle_irq_event(desc);

	if (!irqd_irq_disabled(&desc->irq_data) && !(desc->istate & IRQS_ONESHOT))
		unmask_irq(desc);
out_unlock:
	raw_spin_unlock(&desc->lock);
}
EXPORT_SYMBOL_GPL(handle_level_irq);

#ifdef CONFIG_IRQ_PREFLOW_FASTEOI
static inline void preflow_handler(struct irq_desc *desc)
{
	if (desc->preflow_handler)
		desc->preflow_handler(&desc->irq_data);
}
#else
static inline void preflow_handler(struct irq_desc *desc) { }
#endif

/**
 *	handle_fasteoi_irq - irq handler for transparent controllers
 *	@irq:	the interrupt number
 *	@desc:	the interrupt description structure for this irq
 *
 *	Only a single callback will be issued to the chip: an ->eoi()
 *	call when the interrupt has been serviced. This enables support
 *	for modern forms of interrupt handlers, which handle the flow
 *	details in hardware, transparently.
 */
void
handle_fasteoi_irq(unsigned int irq, struct irq_desc *desc)
{
	raw_spin_lock(&desc->lock);

	if (unlikely(irqd_irq_inprogress(&desc->irq_data)))
		if (!irq_check_poll(desc))
			goto out;

	desc->istate &= ~(IRQS_REPLAY | IRQS_WAITING);
	kstat_incr_irqs_this_cpu(irq, desc);

	/*
	 * If its disabled or no action available
	 * then mask it and get out of here:
	 */
	if (unlikely(!desc->action || irqd_irq_disabled(&desc->irq_data))) {
		desc->istate |= IRQS_PENDING;
		mask_irq(desc);
		goto out;
	}

	if (desc->istate & IRQS_ONESHOT)
		mask_irq(desc);

	preflow_handler(desc);
	handle_irq_event(desc);

out_eoi:
	desc->irq_data.chip->irq_eoi(&desc->irq_data);
out_unlock:
	raw_spin_unlock(&desc->lock);
	return;
out:
	if (!(desc->irq_data.chip->flags & IRQCHIP_EOI_IF_HANDLED))
		goto out_eoi;
	goto out_unlock;
}

/**
 *	handle_edge_irq - edge type IRQ handler
 *	@irq:	the interrupt number
 *	@desc:	the interrupt description structure for this irq
 *
 *	Interrupt occures on the falling and/or rising edge of a hardware
 *	signal. The occurrence is latched into the irq controller hardware
 *	and must be acked in order to be reenabled. After the ack another
 *	interrupt can happen on the same source even before the first one
 *	is handled by the associated event handler. If this happens it
 *	might be necessary to disable (mask) the interrupt depending on the
 *	controller hardware. This requires to reenable the interrupt inside
 *	of the loop which handles the interrupts which have arrived while
 *	the handler was running. If all pending interrupts are handled, the
 *	loop is left.
 */
void
handle_edge_irq(unsigned int irq, struct irq_desc *desc)
{
	raw_spin_lock(&desc->lock);

	desc->istate &= ~(IRQS_REPLAY | IRQS_WAITING);
	/*
	 * If we're currently running this IRQ, or its disabled,
	 * we shouldn't process the IRQ. Mark it pending, handle
	 * the necessary masking and go out
	 */
	if (unlikely(irqd_irq_disabled(&desc->irq_data) ||
		     irqd_irq_inprogress(&desc->irq_data) || !desc->action)) {
		if (!irq_check_poll(desc)) {
			desc->istate |= IRQS_PENDING;
			mask_ack_irq(desc);
			goto out_unlock;
		}
	}
	kstat_incr_irqs_this_cpu(irq, desc);

	/* Start handling the irq */
	desc->irq_data.chip->irq_ack(&desc->irq_data);

	do {
		if (unlikely(!desc->action)) {
			mask_irq(desc);
			goto out_unlock;
		}

		/*
		 * When another irq arrived while we were handling
		 * one, we could have masked the irq.
		 * Renable it, if it was not disabled in meantime.
		 */
		if (unlikely(desc->istate & IRQS_PENDING)) {
			if (!irqd_irq_disabled(&desc->irq_data) &&
			    irqd_irq_masked(&desc->irq_data))
				unmask_irq(desc);
		}

		handle_irq_event(desc);

	} while ((desc->istate & IRQS_PENDING) &&
		 !irqd_irq_disabled(&desc->irq_data));

out_unlock:
	raw_spin_unlock(&desc->lock);
}

#ifdef CONFIG_IRQ_EDGE_EOI_HANDLER
/**
 *	handle_edge_eoi_irq - edge eoi type IRQ handler
 *	@irq:	the interrupt number
 *	@desc:	the interrupt description structure for this irq
 *
 * Similar as the above handle_edge_irq, but using eoi and w/o the
 * mask/unmask logic.
 */
void handle_edge_eoi_irq(unsigned int irq, struct irq_desc *desc)
{
	struct irq_chip *chip = irq_desc_get_chip(desc);

	raw_spin_lock(&desc->lock);

	desc->istate &= ~(IRQS_REPLAY | IRQS_WAITING);
	/*
	 * If we're currently running this IRQ, or its disabled,
	 * we shouldn't process the IRQ. Mark it pending, handle
	 * the necessary masking and go out
	 */
	if (unlikely(irqd_irq_disabled(&desc->irq_data) ||
		     irqd_irq_inprogress(&desc->irq_data) || !desc->action)) {
		if (!irq_check_poll(desc)) {
			desc->istate |= IRQS_PENDING;
			goto out_eoi;
		}
	}
	kstat_incr_irqs_this_cpu(irq, desc);

	do {
		if (unlikely(!desc->action))
			goto out_eoi;

		handle_irq_event(desc);

	} while ((desc->istate & IRQS_PENDING) &&
		 !irqd_irq_disabled(&desc->irq_data));

out_eoi:
	chip->irq_eoi(&desc->irq_data);
	raw_spin_unlock(&desc->lock);
}
#endif

/**
 *	handle_percpu_irq - Per CPU local irq handler
 *	@irq:	the interrupt number
 *	@desc:	the interrupt description structure for this irq
 *
 *	Per CPU interrupts on SMP machines without locking requirements
 */
void
handle_percpu_irq(unsigned int irq, struct irq_desc *desc)
{
	struct irq_chip *chip = irq_desc_get_chip(desc);

	kstat_incr_irqs_this_cpu(irq, desc);

	if (chip->irq_ack)
		chip->irq_ack(&desc->irq_data);

	handle_irq_event_percpu(desc, desc->action);

	if (chip->irq_eoi)
		chip->irq_eoi(&desc->irq_data);
}

void
__irq_set_handler(unsigned int irq, irq_flow_handler_t handle, int is_chained,
		  const char *name)
{
	unsigned long flags;
	struct irq_desc *desc = irq_get_desc_buslock(irq, &flags);

	if (!desc)
		return;

	if (!handle) {
		handle = handle_bad_irq;
	} else {
		if (WARN_ON(desc->irq_data.chip == &no_irq_chip))
			goto out;
	}

	/* Uninstall? */
	if (handle == handle_bad_irq) {
		if (desc->irq_data.chip != &no_irq_chip)
			mask_ack_irq(desc);
		irq_state_set_disabled(desc);
		desc->depth = 1;
	}
	desc->handle_irq = handle;
	desc->name = name;

	if (handle != handle_bad_irq && is_chained) {
		irq_settings_set_noprobe(desc);
		irq_settings_set_norequest(desc);
		irq_settings_set_nothread(desc);
		irq_startup(desc);
	}
out:
	irq_put_desc_busunlock(desc, flags);
}
EXPORT_SYMBOL_GPL(__irq_set_handler);

void
irq_set_chip_and_handler_name(unsigned int irq, struct irq_chip *chip,
			      irq_flow_handler_t handle, const char *name)
{
	irq_set_chip(irq, chip);
	__irq_set_handler(irq, handle, 0, name);
}

void irq_modify_status(unsigned int irq, unsigned long clr, unsigned long set)
{
	unsigned long flags;
	struct irq_desc *desc = irq_get_desc_lock(irq, &flags);

	if (!desc)
		return;
	irq_settings_clr_and_set(desc, clr, set);

	irqd_clear(&desc->irq_data, IRQD_NO_BALANCING | IRQD_PER_CPU |
		   IRQD_TRIGGER_MASK | IRQD_LEVEL | IRQD_MOVE_PCNTXT);
	if (irq_settings_has_no_balance_set(desc))
		irqd_set(&desc->irq_data, IRQD_NO_BALANCING);
	if (irq_settings_is_per_cpu(desc))
		irqd_set(&desc->irq_data, IRQD_PER_CPU);
	if (irq_settings_can_move_pcntxt(desc))
		irqd_set(&desc->irq_data, IRQD_MOVE_PCNTXT);
	if (irq_settings_is_level(desc))
		irqd_set(&desc->irq_data, IRQD_LEVEL);

	irqd_set(&desc->irq_data, irq_settings_get_trigger_mask(desc));

	irq_put_desc_unlock(desc, flags);
}
EXPORT_SYMBOL_GPL(irq_modify_status);

/**
 *	irq_cpu_online - Invoke all irq_cpu_online functions.
 *
 *	Iterate through all irqs and invoke the chip.irq_cpu_online()
 *	for each.
 */
void irq_cpu_online(void)
{
	struct irq_desc *desc;
	struct irq_chip *chip;
	unsigned long flags;
	unsigned int irq;

	for_each_active_irq(irq) {
		desc = irq_to_desc(irq);
		if (!desc)
			continue;

		raw_spin_lock_irqsave(&desc->lock, flags);

		chip = irq_data_get_irq_chip(&desc->irq_data);
		if (chip && chip->irq_cpu_online &&
		    (!(chip->flags & IRQCHIP_ONOFFLINE_ENABLED) ||
		     !irqd_irq_disabled(&desc->irq_data)))
			chip->irq_cpu_online(&desc->irq_data);

		raw_spin_unlock_irqrestore(&desc->lock, flags);
	}
}

/**
 *	irq_cpu_offline - Invoke all irq_cpu_offline functions.
 *
 *	Iterate through all irqs and invoke the chip.irq_cpu_offline()
 *	for each.
 */
void irq_cpu_offline(void)
{
	struct irq_desc *desc;
	struct irq_chip *chip;
	unsigned long flags;
	unsigned int irq;

	for_each_active_irq(irq) {
		desc = irq_to_desc(irq);
		if (!desc)
			continue;

		raw_spin_lock_irqsave(&desc->lock, flags);

		chip = irq_data_get_irq_chip(&desc->irq_data);
		if (chip && chip->irq_cpu_offline &&
		    (!(chip->flags & IRQCHIP_ONOFFLINE_ENABLED) ||
		     !irqd_irq_disabled(&desc->irq_data)))
			chip->irq_cpu_offline(&desc->irq_data);

		raw_spin_unlock_irqrestore(&desc->lock, flags);
	}
}