manage.c 54.8 KB
Newer Older
L
Linus Torvalds 已提交
1 2 3
/*
 * linux/kernel/irq/manage.c
 *
I
Ingo Molnar 已提交
4 5
 * Copyright (C) 1992, 1998-2006 Linus Torvalds, Ingo Molnar
 * Copyright (C) 2005-2006 Thomas Gleixner
L
Linus Torvalds 已提交
6 7 8 9
 *
 * This file contains driver APIs to the irq subsystem.
 */

10 11
#define pr_fmt(fmt) "genirq: " fmt

L
Linus Torvalds 已提交
12
#include <linux/irq.h>
13
#include <linux/kthread.h>
L
Linus Torvalds 已提交
14 15 16
#include <linux/module.h>
#include <linux/random.h>
#include <linux/interrupt.h>
17
#include <linux/slab.h>
18
#include <linux/sched.h>
19
#include <linux/sched/rt.h>
20
#include <linux/sched/task.h>
21
#include <uapi/linux/sched/types.h>
22
#include <linux/task_work.h>
L
Linus Torvalds 已提交
23 24 25

#include "internals.h"

26 27 28 29 30 31 32 33 34 35 36
#ifdef CONFIG_IRQ_FORCED_THREADING
__read_mostly bool force_irqthreads;

static int __init setup_forced_irqthreads(char *arg)
{
	force_irqthreads = true;
	return 0;
}
early_param("threadirqs", setup_forced_irqthreads);
#endif

37
static void __synchronize_hardirq(struct irq_desc *desc)
L
Linus Torvalds 已提交
38
{
39
	bool inprogress;
L
Linus Torvalds 已提交
40

41 42 43 44 45 46 47
	do {
		unsigned long flags;

		/*
		 * Wait until we're out of the critical section.  This might
		 * give the wrong answer due to the lack of memory barriers.
		 */
48
		while (irqd_irq_inprogress(&desc->irq_data))
49 50 51
			cpu_relax();

		/* Ok, that indicated we're done: double-check carefully. */
52
		raw_spin_lock_irqsave(&desc->lock, flags);
53
		inprogress = irqd_irq_inprogress(&desc->irq_data);
54
		raw_spin_unlock_irqrestore(&desc->lock, flags);
55 56

		/* Oops, that failed? */
57
	} while (inprogress);
58 59 60 61 62 63 64 65 66 67 68 69 70 71 72
}

/**
 *	synchronize_hardirq - wait for pending hard IRQ handlers (on other CPUs)
 *	@irq: interrupt number to wait for
 *
 *	This function waits for any pending hard IRQ handlers for this
 *	interrupt to complete before returning. If you use this
 *	function while holding a resource the IRQ handler may need you
 *	will deadlock. It does not take associated threaded handlers
 *	into account.
 *
 *	Do not use this for shutdown scenarios where you must be sure
 *	that all parts (hardirq and threaded handler) have completed.
 *
73 74
 *	Returns: false if a threaded handler is active.
 *
75 76
 *	This function may be called - with care - from IRQ context.
 */
77
bool synchronize_hardirq(unsigned int irq)
78 79
{
	struct irq_desc *desc = irq_to_desc(irq);
80

81
	if (desc) {
82
		__synchronize_hardirq(desc);
83 84 85 86
		return !atomic_read(&desc->threads_active);
	}

	return true;
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
}
EXPORT_SYMBOL(synchronize_hardirq);

/**
 *	synchronize_irq - wait for pending IRQ handlers (on other CPUs)
 *	@irq: interrupt number to wait for
 *
 *	This function waits for any pending IRQ handlers for this interrupt
 *	to complete before returning. If you use this function while
 *	holding a resource the IRQ handler may need you will deadlock.
 *
 *	This function may be called - with care - from IRQ context.
 */
void synchronize_irq(unsigned int irq)
{
	struct irq_desc *desc = irq_to_desc(irq);

	if (desc) {
		__synchronize_hardirq(desc);
		/*
		 * We made sure that no hardirq handler is
		 * running. Now verify that no threaded handlers are
		 * active.
		 */
		wait_event(desc->wait_for_threads,
			   !atomic_read(&desc->threads_active));
	}
L
Linus Torvalds 已提交
114 115 116
}
EXPORT_SYMBOL(synchronize_irq);

117 118 119
#ifdef CONFIG_SMP
cpumask_var_t irq_default_affinity;

120
static bool __irq_can_set_affinity(struct irq_desc *desc)
121 122 123
{
	if (!desc || !irqd_can_balance(&desc->irq_data) ||
	    !desc->irq_data.chip || !desc->irq_data.chip->irq_set_affinity)
124 125
		return false;
	return true;
126 127
}

128 129 130 131 132 133 134
/**
 *	irq_can_set_affinity - Check if the affinity of a given irq can be set
 *	@irq:		Interrupt to check
 *
 */
int irq_can_set_affinity(unsigned int irq)
{
135
	return __irq_can_set_affinity(irq_to_desc(irq));
136 137
}

138 139 140 141 142 143 144 145 146 147 148 149 150 151 152
/**
 * irq_can_set_affinity_usr - Check if affinity of a irq can be set from user space
 * @irq:	Interrupt to check
 *
 * Like irq_can_set_affinity() above, but additionally checks for the
 * AFFINITY_MANAGED flag.
 */
bool irq_can_set_affinity_usr(unsigned int irq)
{
	struct irq_desc *desc = irq_to_desc(irq);

	return __irq_can_set_affinity(desc) &&
		!irqd_affinity_is_managed(&desc->irq_data);
}

153 154 155 156 157 158 159 160 161 162
/**
 *	irq_set_thread_affinity - Notify irq threads to adjust affinity
 *	@desc:		irq descriptor which has affitnity changed
 *
 *	We just set IRQTF_AFFINITY and delegate the affinity setting
 *	to the interrupt thread itself. We can not call
 *	set_cpus_allowed_ptr() here as we hold desc->lock and this
 *	code can be called from hard interrupt context.
 */
void irq_set_thread_affinity(struct irq_desc *desc)
163
{
164
	struct irqaction *action;
165

166
	for_each_action_of_desc(desc, action)
167
		if (action->thread)
168
			set_bit(IRQTF_AFFINITY, &action->thread_flags);
169 170
}

171
#ifdef CONFIG_GENERIC_PENDING_IRQ
T
Thomas Gleixner 已提交
172
static inline bool irq_can_move_pcntxt(struct irq_data *data)
173
{
T
Thomas Gleixner 已提交
174
	return irqd_can_move_in_process_context(data);
175
}
T
Thomas Gleixner 已提交
176
static inline bool irq_move_pending(struct irq_data *data)
177
{
T
Thomas Gleixner 已提交
178
	return irqd_is_setaffinity_pending(data);
179 180 181 182 183 184 185 186 187 188 189 190
}
static inline void
irq_copy_pending(struct irq_desc *desc, const struct cpumask *mask)
{
	cpumask_copy(desc->pending_mask, mask);
}
static inline void
irq_get_pending(struct cpumask *mask, struct irq_desc *desc)
{
	cpumask_copy(mask, desc->pending_mask);
}
#else
T
Thomas Gleixner 已提交
191
static inline bool irq_can_move_pcntxt(struct irq_data *data) { return true; }
T
Thomas Gleixner 已提交
192
static inline bool irq_move_pending(struct irq_data *data) { return false; }
193 194 195 196 197 198
static inline void
irq_copy_pending(struct irq_desc *desc, const struct cpumask *mask) { }
static inline void
irq_get_pending(struct cpumask *mask, struct irq_desc *desc) { }
#endif

199 200 201 202 203 204 205
int irq_do_set_affinity(struct irq_data *data, const struct cpumask *mask,
			bool force)
{
	struct irq_desc *desc = irq_data_to_desc(data);
	struct irq_chip *chip = irq_data_get_irq_chip(data);
	int ret;

206
	ret = chip->irq_set_affinity(data, mask, force);
207 208
	switch (ret) {
	case IRQ_SET_MASK_OK:
209
	case IRQ_SET_MASK_OK_DONE:
210
		cpumask_copy(desc->irq_common_data.affinity, mask);
211 212 213 214 215 216 217 218
	case IRQ_SET_MASK_OK_NOCOPY:
		irq_set_thread_affinity(desc);
		ret = 0;
	}

	return ret;
}

219 220
int irq_set_affinity_locked(struct irq_data *data, const struct cpumask *mask,
			    bool force)
221
{
222 223
	struct irq_chip *chip = irq_data_get_irq_chip(data);
	struct irq_desc *desc = irq_data_to_desc(data);
224
	int ret = 0;
225

226
	if (!chip || !chip->irq_set_affinity)
227 228
		return -EINVAL;

T
Thomas Gleixner 已提交
229
	if (irq_can_move_pcntxt(data)) {
230
		ret = irq_do_set_affinity(data, mask, force);
231
	} else {
232
		irqd_set_move_pending(data);
233
		irq_copy_pending(desc, mask);
234
	}
235

236 237 238 239
	if (desc->affinity_notify) {
		kref_get(&desc->affinity_notify->kref);
		schedule_work(&desc->affinity_notify->work);
	}
240 241 242 243 244
	irqd_set(data, IRQD_AFFINITY_SET);

	return ret;
}

245
int __irq_set_affinity(unsigned int irq, const struct cpumask *mask, bool force)
246 247 248 249 250 251 252 253 254
{
	struct irq_desc *desc = irq_to_desc(irq);
	unsigned long flags;
	int ret;

	if (!desc)
		return -EINVAL;

	raw_spin_lock_irqsave(&desc->lock, flags);
255
	ret = irq_set_affinity_locked(irq_desc_get_irq_data(desc), mask, force);
256
	raw_spin_unlock_irqrestore(&desc->lock, flags);
257
	return ret;
258 259
}

260 261 262
int irq_set_affinity_hint(unsigned int irq, const struct cpumask *m)
{
	unsigned long flags;
263
	struct irq_desc *desc = irq_get_desc_lock(irq, &flags, IRQ_GET_DESC_CHECK_GLOBAL);
264 265 266 267

	if (!desc)
		return -EINVAL;
	desc->affinity_hint = m;
268
	irq_put_desc_unlock(desc, flags);
269
	/* set the initial affinity to prevent every interrupt being on CPU0 */
270 271
	if (m)
		__irq_set_affinity(irq, m, false);
272 273 274 275
	return 0;
}
EXPORT_SYMBOL_GPL(irq_set_affinity_hint);

276 277 278 279 280 281 282 283
static void irq_affinity_notify(struct work_struct *work)
{
	struct irq_affinity_notify *notify =
		container_of(work, struct irq_affinity_notify, work);
	struct irq_desc *desc = irq_to_desc(notify->irq);
	cpumask_var_t cpumask;
	unsigned long flags;

284
	if (!desc || !alloc_cpumask_var(&cpumask, GFP_KERNEL))
285 286 287
		goto out;

	raw_spin_lock_irqsave(&desc->lock, flags);
T
Thomas Gleixner 已提交
288
	if (irq_move_pending(&desc->irq_data))
289
		irq_get_pending(cpumask, desc);
290
	else
291
		cpumask_copy(cpumask, desc->irq_common_data.affinity);
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
	raw_spin_unlock_irqrestore(&desc->lock, flags);

	notify->notify(notify, cpumask);

	free_cpumask_var(cpumask);
out:
	kref_put(&notify->kref, notify->release);
}

/**
 *	irq_set_affinity_notifier - control notification of IRQ affinity changes
 *	@irq:		Interrupt for which to enable/disable notification
 *	@notify:	Context for notification, or %NULL to disable
 *			notification.  Function pointers must be initialised;
 *			the other fields will be initialised by this function.
 *
 *	Must be called in process context.  Notification may only be enabled
 *	after the IRQ is allocated and must be disabled before the IRQ is
 *	freed using free_irq().
 */
int
irq_set_affinity_notifier(unsigned int irq, struct irq_affinity_notify *notify)
{
	struct irq_desc *desc = irq_to_desc(irq);
	struct irq_affinity_notify *old_notify;
	unsigned long flags;

	/* The release function is promised process context */
	might_sleep();

	if (!desc)
		return -EINVAL;

	/* Complete initialisation of *notify */
	if (notify) {
		notify->irq = irq;
		kref_init(&notify->kref);
		INIT_WORK(&notify->work, irq_affinity_notify);
	}

	raw_spin_lock_irqsave(&desc->lock, flags);
	old_notify = desc->affinity_notify;
	desc->affinity_notify = notify;
	raw_spin_unlock_irqrestore(&desc->lock, flags);

	if (old_notify)
		kref_put(&old_notify->kref, old_notify->release);

	return 0;
}
EXPORT_SYMBOL_GPL(irq_set_affinity_notifier);

344 345 346 347
#ifndef CONFIG_AUTO_IRQ_AFFINITY
/*
 * Generic version of the affinity autoselector.
 */
348
int irq_setup_affinity(struct irq_desc *desc)
349
{
350
	struct cpumask *set = irq_default_affinity;
351 352 353
	int ret, node = irq_desc_get_node(desc);
	static DEFINE_RAW_SPINLOCK(mask_lock);
	static struct cpumask mask;
354

355
	/* Excludes PER_CPU and NO_BALANCE interrupts */
356
	if (!__irq_can_set_affinity(desc))
357 358
		return 0;

359
	raw_spin_lock(&mask_lock);
360
	/*
361
	 * Preserve the managed affinity setting and a userspace affinity
362
	 * setup, but make sure that one of the targets is online.
363
	 */
364 365
	if (irqd_affinity_is_managed(&desc->irq_data) ||
	    irqd_has_set(&desc->irq_data, IRQD_AFFINITY_SET)) {
366
		if (cpumask_intersects(desc->irq_common_data.affinity,
367
				       cpu_online_mask))
368
			set = desc->irq_common_data.affinity;
T
Thomas Gleixner 已提交
369
		else
370
			irqd_clear(&desc->irq_data, IRQD_AFFINITY_SET);
371
	}
372

373
	cpumask_and(&mask, cpu_online_mask, set);
374 375 376 377
	if (node != NUMA_NO_NODE) {
		const struct cpumask *nodemask = cpumask_of_node(node);

		/* make sure at least one of the cpus in nodemask is online */
378 379
		if (cpumask_intersects(&mask, nodemask))
			cpumask_and(&mask, &mask, nodemask);
380
	}
381 382 383
	ret = irq_do_set_affinity(&desc->irq_data, &mask, false);
	raw_spin_unlock(&mask_lock);
	return ret;
384
}
385
#else
386
/* Wrapper for ALPHA specific affinity selector magic */
387
int irq_setup_affinity(struct irq_desc *desc)
388
{
389
	return irq_select_affinity(irq_desc_get_irq(desc));
390
}
391 392
#endif

393
/*
394
 * Called when a bogus affinity is set via /proc/irq
395
 */
396
int irq_select_affinity_usr(unsigned int irq)
397 398 399 400 401
{
	struct irq_desc *desc = irq_to_desc(irq);
	unsigned long flags;
	int ret;

402
	raw_spin_lock_irqsave(&desc->lock, flags);
403
	ret = irq_setup_affinity(desc);
404
	raw_spin_unlock_irqrestore(&desc->lock, flags);
405 406
	return ret;
}
L
Linus Torvalds 已提交
407 408
#endif

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
/**
 *	irq_set_vcpu_affinity - Set vcpu affinity for the interrupt
 *	@irq: interrupt number to set affinity
 *	@vcpu_info: vCPU specific data
 *
 *	This function uses the vCPU specific data to set the vCPU
 *	affinity for an irq. The vCPU specific data is passed from
 *	outside, such as KVM. One example code path is as below:
 *	KVM -> IOMMU -> irq_set_vcpu_affinity().
 */
int irq_set_vcpu_affinity(unsigned int irq, void *vcpu_info)
{
	unsigned long flags;
	struct irq_desc *desc = irq_get_desc_lock(irq, &flags, 0);
	struct irq_data *data;
	struct irq_chip *chip;
	int ret = -ENOSYS;

	if (!desc)
		return -EINVAL;

	data = irq_desc_get_irq_data(desc);
	chip = irq_data_get_irq_chip(data);
	if (chip && chip->irq_set_vcpu_affinity)
		ret = chip->irq_set_vcpu_affinity(data, vcpu_info);
	irq_put_desc_unlock(desc, flags);

	return ret;
}
EXPORT_SYMBOL_GPL(irq_set_vcpu_affinity);

440
void __disable_irq(struct irq_desc *desc)
441
{
442
	if (!desc->depth++)
443
		irq_disable(desc);
444 445
}

446 447 448
static int __disable_irq_nosync(unsigned int irq)
{
	unsigned long flags;
449
	struct irq_desc *desc = irq_get_desc_buslock(irq, &flags, IRQ_GET_DESC_CHECK_GLOBAL);
450 451 452

	if (!desc)
		return -EINVAL;
453
	__disable_irq(desc);
454 455 456 457
	irq_put_desc_busunlock(desc, flags);
	return 0;
}

L
Linus Torvalds 已提交
458 459 460 461 462 463 464 465 466 467 468 469 470
/**
 *	disable_irq_nosync - disable an irq without waiting
 *	@irq: Interrupt to disable
 *
 *	Disable the selected interrupt line.  Disables and Enables are
 *	nested.
 *	Unlike disable_irq(), this function does not ensure existing
 *	instances of the IRQ handler have completed before returning.
 *
 *	This function may be called from IRQ context.
 */
void disable_irq_nosync(unsigned int irq)
{
471
	__disable_irq_nosync(irq);
L
Linus Torvalds 已提交
472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488
}
EXPORT_SYMBOL(disable_irq_nosync);

/**
 *	disable_irq - disable an irq and wait for completion
 *	@irq: Interrupt to disable
 *
 *	Disable the selected interrupt line.  Enables and Disables are
 *	nested.
 *	This function waits for any pending IRQ handlers for this interrupt
 *	to complete before returning. If you use this function while
 *	holding a resource the IRQ handler may need you will deadlock.
 *
 *	This function may be called - with care - from IRQ context.
 */
void disable_irq(unsigned int irq)
{
489
	if (!__disable_irq_nosync(irq))
L
Linus Torvalds 已提交
490 491 492 493
		synchronize_irq(irq);
}
EXPORT_SYMBOL(disable_irq);

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
/**
 *	disable_hardirq - disables an irq and waits for hardirq completion
 *	@irq: Interrupt to disable
 *
 *	Disable the selected interrupt line.  Enables and Disables are
 *	nested.
 *	This function waits for any pending hard IRQ handlers for this
 *	interrupt to complete before returning. If you use this function while
 *	holding a resource the hard IRQ handler may need you will deadlock.
 *
 *	When used to optimistically disable an interrupt from atomic context
 *	the return value must be checked.
 *
 *	Returns: false if a threaded handler is active.
 *
 *	This function may be called - with care - from IRQ context.
 */
bool disable_hardirq(unsigned int irq)
{
	if (!__disable_irq_nosync(irq))
		return synchronize_hardirq(irq);

	return false;
}
EXPORT_SYMBOL_GPL(disable_hardirq);

520
void __enable_irq(struct irq_desc *desc)
521 522 523
{
	switch (desc->depth) {
	case 0:
524
 err_out:
525 526
		WARN(1, KERN_WARNING "Unbalanced enable for IRQ %d\n",
		     irq_desc_get_irq(desc));
527 528
		break;
	case 1: {
529
		if (desc->istate & IRQS_SUSPENDED)
530
			goto err_out;
531
		/* Prevent probing on this irq: */
532
		irq_settings_set_noprobe(desc);
533 534 535 536 537 538 539 540 541
		/*
		 * Call irq_startup() not irq_enable() here because the
		 * interrupt might be marked NOAUTOEN. So irq_startup()
		 * needs to be invoked when it gets enabled the first
		 * time. If it was already started up, then irq_startup()
		 * will invoke irq_enable() under the hood.
		 */
		irq_startup(desc, true);
		break;
542 543 544 545 546 547
	}
	default:
		desc->depth--;
	}
}

L
Linus Torvalds 已提交
548 549 550 551 552 553 554 555
/**
 *	enable_irq - enable handling of an irq
 *	@irq: Interrupt to enable
 *
 *	Undoes the effect of one call to disable_irq().  If this
 *	matches the last disable, processing of interrupts on this
 *	IRQ line is re-enabled.
 *
T
Thomas Gleixner 已提交
556
 *	This function may be called from IRQ context only when
557
 *	desc->irq_data.chip->bus_lock and desc->chip->bus_sync_unlock are NULL !
L
Linus Torvalds 已提交
558 559 560 561
 */
void enable_irq(unsigned int irq)
{
	unsigned long flags;
562
	struct irq_desc *desc = irq_get_desc_buslock(irq, &flags, IRQ_GET_DESC_CHECK_GLOBAL);
L
Linus Torvalds 已提交
563

564
	if (!desc)
565
		return;
T
Thomas Gleixner 已提交
566 567
	if (WARN(!desc->irq_data.chip,
		 KERN_ERR "enable_irq before setup/request_irq: irq %u\n", irq))
568
		goto out;
569

570
	__enable_irq(desc);
571 572
out:
	irq_put_desc_busunlock(desc, flags);
L
Linus Torvalds 已提交
573 574 575
}
EXPORT_SYMBOL(enable_irq);

D
David Brownell 已提交
576
static int set_irq_wake_real(unsigned int irq, unsigned int on)
577
{
578
	struct irq_desc *desc = irq_to_desc(irq);
579 580
	int ret = -ENXIO;

581 582 583
	if (irq_desc_get_chip(desc)->flags &  IRQCHIP_SKIP_SET_WAKE)
		return 0;

584 585
	if (desc->irq_data.chip->irq_set_wake)
		ret = desc->irq_data.chip->irq_set_wake(&desc->irq_data, on);
586 587 588 589

	return ret;
}

590
/**
T
Thomas Gleixner 已提交
591
 *	irq_set_irq_wake - control irq power management wakeup
592 593 594
 *	@irq:	interrupt to control
 *	@on:	enable/disable power management wakeup
 *
595 596 597 598 599 600
 *	Enable/disable power management wakeup mode, which is
 *	disabled by default.  Enables and disables must match,
 *	just as they match for non-wakeup mode support.
 *
 *	Wakeup mode lets this IRQ wake the system from sleep
 *	states like "suspend to RAM".
601
 */
T
Thomas Gleixner 已提交
602
int irq_set_irq_wake(unsigned int irq, unsigned int on)
603 604
{
	unsigned long flags;
605
	struct irq_desc *desc = irq_get_desc_buslock(irq, &flags, IRQ_GET_DESC_CHECK_GLOBAL);
606
	int ret = 0;
607

608 609 610
	if (!desc)
		return -EINVAL;

611 612 613 614
	/* wakeup-capable irqs can be shared between drivers that
	 * don't need to have the same sleep mode behaviors.
	 */
	if (on) {
615 616 617 618 619
		if (desc->wake_depth++ == 0) {
			ret = set_irq_wake_real(irq, on);
			if (ret)
				desc->wake_depth = 0;
			else
620
				irqd_set(&desc->irq_data, IRQD_WAKEUP_STATE);
621
		}
622 623
	} else {
		if (desc->wake_depth == 0) {
624
			WARN(1, "Unbalanced IRQ %d wake disable\n", irq);
625 626 627 628 629
		} else if (--desc->wake_depth == 0) {
			ret = set_irq_wake_real(irq, on);
			if (ret)
				desc->wake_depth = 1;
			else
630
				irqd_clear(&desc->irq_data, IRQD_WAKEUP_STATE);
631
		}
632
	}
633
	irq_put_desc_busunlock(desc, flags);
634 635
	return ret;
}
T
Thomas Gleixner 已提交
636
EXPORT_SYMBOL(irq_set_irq_wake);
637

L
Linus Torvalds 已提交
638 639 640 641 642 643 644
/*
 * Internal function that tells the architecture code whether a
 * particular irq has been exclusively allocated or is available
 * for driver use.
 */
int can_request_irq(unsigned int irq, unsigned long irqflags)
{
645
	unsigned long flags;
646
	struct irq_desc *desc = irq_get_desc_lock(irq, &flags, 0);
647
	int canrequest = 0;
L
Linus Torvalds 已提交
648

649 650 651
	if (!desc)
		return 0;

652
	if (irq_settings_can_request(desc)) {
653 654 655
		if (!desc->action ||
		    irqflags & desc->action->flags & IRQF_SHARED)
			canrequest = 1;
656 657 658
	}
	irq_put_desc_unlock(desc, flags);
	return canrequest;
L
Linus Torvalds 已提交
659 660
}

661
int __irq_set_trigger(struct irq_desc *desc, unsigned long flags)
662
{
663
	struct irq_chip *chip = desc->irq_data.chip;
664
	int ret, unmask = 0;
665

666
	if (!chip || !chip->irq_set_type) {
667 668 669 670
		/*
		 * IRQF_TRIGGER_* but the PIC does not support multiple
		 * flow-types?
		 */
671 672
		pr_debug("No set_type function for IRQ %d (%s)\n",
			 irq_desc_get_irq(desc),
673
			 chip ? (chip->name ? : "unknown") : "unknown");
674 675 676
		return 0;
	}

677
	if (chip->flags & IRQCHIP_SET_TYPE_MASKED) {
678
		if (!irqd_irq_masked(&desc->irq_data))
679
			mask_irq(desc);
680
		if (!irqd_irq_disabled(&desc->irq_data))
681 682 683
			unmask = 1;
	}

684 685
	/* Mask all flags except trigger mode */
	flags &= IRQ_TYPE_SENSE_MASK;
686
	ret = chip->irq_set_type(&desc->irq_data, flags);
687

688 689
	switch (ret) {
	case IRQ_SET_MASK_OK:
690
	case IRQ_SET_MASK_OK_DONE:
691 692 693 694 695 696 697 698 699 700 701 702
		irqd_clear(&desc->irq_data, IRQD_TRIGGER_MASK);
		irqd_set(&desc->irq_data, flags);

	case IRQ_SET_MASK_OK_NOCOPY:
		flags = irqd_get_trigger_type(&desc->irq_data);
		irq_settings_set_trigger_mask(desc, flags);
		irqd_clear(&desc->irq_data, IRQD_LEVEL);
		irq_settings_clr_level(desc);
		if (flags & IRQ_TYPE_LEVEL_MASK) {
			irq_settings_set_level(desc);
			irqd_set(&desc->irq_data, IRQD_LEVEL);
		}
703

704
		ret = 0;
705
		break;
706
	default:
707
		pr_err("Setting trigger mode %lu for irq %u failed (%pF)\n",
708
		       flags, irq_desc_get_irq(desc), chip->irq_set_type);
D
David Brownell 已提交
709
	}
710 711
	if (unmask)
		unmask_irq(desc);
712 713 714
	return ret;
}

715 716 717 718 719 720 721 722 723 724 725 726 727 728
#ifdef CONFIG_HARDIRQS_SW_RESEND
int irq_set_parent(int irq, int parent_irq)
{
	unsigned long flags;
	struct irq_desc *desc = irq_get_desc_lock(irq, &flags, 0);

	if (!desc)
		return -EINVAL;

	desc->parent_irq = parent_irq;

	irq_put_desc_unlock(desc, flags);
	return 0;
}
729
EXPORT_SYMBOL_GPL(irq_set_parent);
730 731
#endif

T
Thomas Gleixner 已提交
732 733 734 735 736 737 738 739 740 741
/*
 * Default primary interrupt handler for threaded interrupts. Is
 * assigned as primary handler when request_threaded_irq is called
 * with handler == NULL. Useful for oneshot interrupts.
 */
static irqreturn_t irq_default_primary_handler(int irq, void *dev_id)
{
	return IRQ_WAKE_THREAD;
}

742 743 744 745 746 747 748 749 750 751
/*
 * Primary handler for nested threaded interrupts. Should never be
 * called.
 */
static irqreturn_t irq_nested_primary_handler(int irq, void *dev_id)
{
	WARN(1, "Primary handler called for nested irq %d\n", irq);
	return IRQ_NONE;
}

752 753 754 755 756 757
static irqreturn_t irq_forced_secondary_handler(int irq, void *dev_id)
{
	WARN(1, "Secondary action handler called for irq %d\n", irq);
	return IRQ_NONE;
}

758 759
static int irq_wait_for_interrupt(struct irqaction *action)
{
760 761
	set_current_state(TASK_INTERRUPTIBLE);

762
	while (!kthread_should_stop()) {
763 764 765

		if (test_and_clear_bit(IRQTF_RUNTHREAD,
				       &action->thread_flags)) {
766 767
			__set_current_state(TASK_RUNNING);
			return 0;
768 769
		}
		schedule();
770
		set_current_state(TASK_INTERRUPTIBLE);
771
	}
772
	__set_current_state(TASK_RUNNING);
773 774 775
	return -1;
}

T
Thomas Gleixner 已提交
776 777 778 779 780
/*
 * Oneshot interrupts keep the irq line masked until the threaded
 * handler finished. unmask if the interrupt has not been disabled and
 * is marked MASKED.
 */
781
static void irq_finalize_oneshot(struct irq_desc *desc,
782
				 struct irqaction *action)
T
Thomas Gleixner 已提交
783
{
784 785
	if (!(desc->istate & IRQS_ONESHOT) ||
	    action->handler == irq_forced_secondary_handler)
786
		return;
787
again:
788
	chip_bus_lock(desc);
789
	raw_spin_lock_irq(&desc->lock);
790 791 792 793 794 795 796 797

	/*
	 * Implausible though it may be we need to protect us against
	 * the following scenario:
	 *
	 * The thread is faster done than the hard interrupt handler
	 * on the other CPU. If we unmask the irq line then the
	 * interrupt can come in again and masks the line, leaves due
798
	 * to IRQS_INPROGRESS and the irq line is masked forever.
799 800 801 802 803
	 *
	 * This also serializes the state of shared oneshot handlers
	 * versus "desc->threads_onehsot |= action->thread_mask;" in
	 * irq_wake_thread(). See the comment there which explains the
	 * serialization.
804
	 */
805
	if (unlikely(irqd_irq_inprogress(&desc->irq_data))) {
806
		raw_spin_unlock_irq(&desc->lock);
807
		chip_bus_sync_unlock(desc);
808 809 810 811
		cpu_relax();
		goto again;
	}

812 813 814 815 816
	/*
	 * Now check again, whether the thread should run. Otherwise
	 * we would clear the threads_oneshot bit of this thread which
	 * was just set.
	 */
817
	if (test_bit(IRQTF_RUNTHREAD, &action->thread_flags))
818 819 820 821
		goto out_unlock;

	desc->threads_oneshot &= ~action->thread_mask;

822 823
	if (!desc->threads_oneshot && !irqd_irq_disabled(&desc->irq_data) &&
	    irqd_irq_masked(&desc->irq_data))
824
		unmask_threaded_irq(desc);
825

826
out_unlock:
827
	raw_spin_unlock_irq(&desc->lock);
828
	chip_bus_sync_unlock(desc);
T
Thomas Gleixner 已提交
829 830
}

831
#ifdef CONFIG_SMP
832
/*
833
 * Check whether we need to change the affinity of the interrupt thread.
834 835 836 837 838
 */
static void
irq_thread_check_affinity(struct irq_desc *desc, struct irqaction *action)
{
	cpumask_var_t mask;
839
	bool valid = true;
840 841 842 843 844 845 846 847 848 849 850 851 852

	if (!test_and_clear_bit(IRQTF_AFFINITY, &action->thread_flags))
		return;

	/*
	 * In case we are out of memory we set IRQTF_AFFINITY again and
	 * try again next time
	 */
	if (!alloc_cpumask_var(&mask, GFP_KERNEL)) {
		set_bit(IRQTF_AFFINITY, &action->thread_flags);
		return;
	}

853
	raw_spin_lock_irq(&desc->lock);
854 855 856 857
	/*
	 * This code is triggered unconditionally. Check the affinity
	 * mask pointer. For CPU_MASK_OFFSTACK=n this is optimized out.
	 */
858
	if (cpumask_available(desc->irq_common_data.affinity))
859
		cpumask_copy(mask, desc->irq_common_data.affinity);
860 861
	else
		valid = false;
862
	raw_spin_unlock_irq(&desc->lock);
863

864 865
	if (valid)
		set_cpus_allowed_ptr(current, mask);
866 867
	free_cpumask_var(mask);
}
868 869 870 871
#else
static inline void
irq_thread_check_affinity(struct irq_desc *desc, struct irqaction *action) { }
#endif
872

873 874 875 876 877 878
/*
 * Interrupts which are not explicitely requested as threaded
 * interrupts rely on the implicit bh/preempt disable of the hard irq
 * context. So we need to disable bh here to avoid deadlocks and other
 * side effects.
 */
879
static irqreturn_t
880 881
irq_forced_thread_fn(struct irq_desc *desc, struct irqaction *action)
{
882 883
	irqreturn_t ret;

884
	local_bh_disable();
885
	ret = action->thread_fn(action->irq, action->dev_id);
886
	irq_finalize_oneshot(desc, action);
887
	local_bh_enable();
888
	return ret;
889 890 891
}

/*
892
 * Interrupts explicitly requested as threaded interrupts want to be
893 894 895
 * preemtible - many of them need to sleep and wait for slow busses to
 * complete.
 */
896 897
static irqreturn_t irq_thread_fn(struct irq_desc *desc,
		struct irqaction *action)
898
{
899 900 901
	irqreturn_t ret;

	ret = action->thread_fn(action->irq, action->dev_id);
902
	irq_finalize_oneshot(desc, action);
903
	return ret;
904 905
}

906 907
static void wake_threads_waitq(struct irq_desc *desc)
{
908
	if (atomic_dec_and_test(&desc->threads_active))
909 910 911
		wake_up(&desc->wait_for_threads);
}

912
static void irq_thread_dtor(struct callback_head *unused)
913 914 915 916 917 918 919 920 921 922
{
	struct task_struct *tsk = current;
	struct irq_desc *desc;
	struct irqaction *action;

	if (WARN_ON_ONCE(!(current->flags & PF_EXITING)))
		return;

	action = kthread_data(tsk);

923
	pr_err("exiting task \"%s\" (%d) is an active IRQ thread (irq %d)\n",
A
Alan Cox 已提交
924
	       tsk->comm, tsk->pid, action->irq);
925 926 927 928 929 930 931 932 933 934 935 936 937 938


	desc = irq_to_desc(action->irq);
	/*
	 * If IRQTF_RUNTHREAD is set, we need to decrement
	 * desc->threads_active and wake possible waiters.
	 */
	if (test_and_clear_bit(IRQTF_RUNTHREAD, &action->thread_flags))
		wake_threads_waitq(desc);

	/* Prevent a stale desc->threads_oneshot */
	irq_finalize_oneshot(desc, action);
}

939 940 941 942 943 944 945 946 947 948 949 950
static void irq_wake_secondary(struct irq_desc *desc, struct irqaction *action)
{
	struct irqaction *secondary = action->secondary;

	if (WARN_ON_ONCE(!secondary))
		return;

	raw_spin_lock_irq(&desc->lock);
	__irq_wake_thread(desc, secondary);
	raw_spin_unlock_irq(&desc->lock);
}

951 952 953 954 955
/*
 * Interrupt handler thread
 */
static int irq_thread(void *data)
{
956
	struct callback_head on_exit_work;
957 958
	struct irqaction *action = data;
	struct irq_desc *desc = irq_to_desc(action->irq);
959 960
	irqreturn_t (*handler_fn)(struct irq_desc *desc,
			struct irqaction *action);
961

962
	if (force_irqthreads && test_bit(IRQTF_FORCED_THREAD,
963 964 965 966 967
					&action->thread_flags))
		handler_fn = irq_forced_thread_fn;
	else
		handler_fn = irq_thread_fn;

A
Al Viro 已提交
968
	init_task_work(&on_exit_work, irq_thread_dtor);
969
	task_work_add(current, &on_exit_work, false);
970

971 972
	irq_thread_check_affinity(desc, action);

973
	while (!irq_wait_for_interrupt(action)) {
974
		irqreturn_t action_ret;
975

976 977
		irq_thread_check_affinity(desc, action);

978
		action_ret = handler_fn(desc, action);
979 980
		if (action_ret == IRQ_HANDLED)
			atomic_inc(&desc->threads_handled);
981 982
		if (action_ret == IRQ_WAKE_THREAD)
			irq_wake_secondary(desc, action);
983

984
		wake_threads_waitq(desc);
985 986
	}

987 988 989 990
	/*
	 * This is the regular exit path. __free_irq() is stopping the
	 * thread via kthread_stop() after calling
	 * synchronize_irq(). So neither IRQTF_RUNTHREAD nor the
991 992 993 994
	 * oneshot mask bit can be set. We cannot verify that as we
	 * cannot touch the oneshot mask at this point anymore as
	 * __setup_irq() might have given out currents thread_mask
	 * again.
995
	 */
996
	task_work_cancel(current, irq_thread_dtor);
997 998 999
	return 0;
}

1000 1001 1002 1003 1004 1005 1006 1007 1008 1009 1010 1011 1012 1013 1014 1015
/**
 *	irq_wake_thread - wake the irq thread for the action identified by dev_id
 *	@irq:		Interrupt line
 *	@dev_id:	Device identity for which the thread should be woken
 *
 */
void irq_wake_thread(unsigned int irq, void *dev_id)
{
	struct irq_desc *desc = irq_to_desc(irq);
	struct irqaction *action;
	unsigned long flags;

	if (!desc || WARN_ON(irq_settings_is_per_cpu_devid(desc)))
		return;

	raw_spin_lock_irqsave(&desc->lock, flags);
1016
	for_each_action_of_desc(desc, action) {
1017 1018 1019 1020 1021 1022 1023 1024 1025 1026
		if (action->dev_id == dev_id) {
			if (action->thread)
				__irq_wake_thread(desc, action);
			break;
		}
	}
	raw_spin_unlock_irqrestore(&desc->lock, flags);
}
EXPORT_SYMBOL_GPL(irq_wake_thread);

1027
static int irq_setup_forced_threading(struct irqaction *new)
1028 1029
{
	if (!force_irqthreads)
1030
		return 0;
1031
	if (new->flags & (IRQF_NO_THREAD | IRQF_PERCPU | IRQF_ONESHOT))
1032
		return 0;
1033 1034 1035

	new->flags |= IRQF_ONESHOT;

1036 1037 1038 1039 1040 1041 1042 1043 1044 1045 1046 1047 1048 1049 1050
	/*
	 * Handle the case where we have a real primary handler and a
	 * thread handler. We force thread them as well by creating a
	 * secondary action.
	 */
	if (new->handler != irq_default_primary_handler && new->thread_fn) {
		/* Allocate the secondary action */
		new->secondary = kzalloc(sizeof(struct irqaction), GFP_KERNEL);
		if (!new->secondary)
			return -ENOMEM;
		new->secondary->handler = irq_forced_secondary_handler;
		new->secondary->thread_fn = new->thread_fn;
		new->secondary->dev_id = new->dev_id;
		new->secondary->irq = new->irq;
		new->secondary->name = new->name;
1051
	}
1052 1053 1054 1055 1056
	/* Deal with the primary handler */
	set_bit(IRQTF_FORCED_THREAD, &new->thread_flags);
	new->thread_fn = new->handler;
	new->handler = irq_default_primary_handler;
	return 0;
1057 1058
}

1059 1060 1061 1062 1063 1064 1065 1066 1067 1068 1069 1070 1071 1072 1073 1074 1075
static int irq_request_resources(struct irq_desc *desc)
{
	struct irq_data *d = &desc->irq_data;
	struct irq_chip *c = d->chip;

	return c->irq_request_resources ? c->irq_request_resources(d) : 0;
}

static void irq_release_resources(struct irq_desc *desc)
{
	struct irq_data *d = &desc->irq_data;
	struct irq_chip *c = d->chip;

	if (c->irq_release_resources)
		c->irq_release_resources(d);
}

1076 1077 1078 1079 1080 1081 1082 1083 1084 1085 1086 1087 1088 1089 1090 1091 1092 1093 1094 1095 1096 1097 1098 1099 1100 1101 1102 1103 1104 1105 1106 1107 1108 1109 1110 1111 1112 1113 1114 1115 1116 1117
static int
setup_irq_thread(struct irqaction *new, unsigned int irq, bool secondary)
{
	struct task_struct *t;
	struct sched_param param = {
		.sched_priority = MAX_USER_RT_PRIO/2,
	};

	if (!secondary) {
		t = kthread_create(irq_thread, new, "irq/%d-%s", irq,
				   new->name);
	} else {
		t = kthread_create(irq_thread, new, "irq/%d-s-%s", irq,
				   new->name);
		param.sched_priority -= 1;
	}

	if (IS_ERR(t))
		return PTR_ERR(t);

	sched_setscheduler_nocheck(t, SCHED_FIFO, &param);

	/*
	 * We keep the reference to the task struct even if
	 * the thread dies to avoid that the interrupt code
	 * references an already freed task_struct.
	 */
	get_task_struct(t);
	new->thread = t;
	/*
	 * Tell the thread to set its affinity. This is
	 * important for shared interrupt handlers as we do
	 * not invoke setup_affinity() for the secondary
	 * handlers as everything is already set up. Even for
	 * interrupts marked with IRQF_NO_BALANCE this is
	 * correct as we want the thread to move to the cpu(s)
	 * on which the requesting code placed the interrupt.
	 */
	set_bit(IRQTF_AFFINITY, &new->thread_flags);
	return 0;
}

L
Linus Torvalds 已提交
1118 1119 1120 1121
/*
 * Internal function to register an irqaction - typically used to
 * allocate special interrupts that are part of the architecture.
 */
1122
static int
I
Ingo Molnar 已提交
1123
__setup_irq(unsigned int irq, struct irq_desc *desc, struct irqaction *new)
L
Linus Torvalds 已提交
1124
{
1125
	struct irqaction *old, **old_ptr;
1126
	unsigned long flags, thread_mask = 0;
1127
	int ret, nested, shared = 0;
L
Linus Torvalds 已提交
1128

1129
	if (!desc)
1130 1131
		return -EINVAL;

1132
	if (desc->irq_data.chip == &no_irq_chip)
L
Linus Torvalds 已提交
1133
		return -ENOSYS;
1134 1135
	if (!try_module_get(desc->owner))
		return -ENODEV;
L
Linus Torvalds 已提交
1136

1137 1138
	new->irq = irq;

1139 1140 1141 1142 1143 1144 1145
	/*
	 * If the trigger type is not specified by the caller,
	 * then use the default for this interrupt.
	 */
	if (!(new->flags & IRQF_TRIGGER_MASK))
		new->flags |= irqd_get_trigger_type(&desc->irq_data);

1146
	/*
1147 1148 1149
	 * Check whether the interrupt nests into another interrupt
	 * thread.
	 */
1150
	nested = irq_settings_is_nested_thread(desc);
1151
	if (nested) {
1152 1153 1154 1155
		if (!new->thread_fn) {
			ret = -EINVAL;
			goto out_mput;
		}
1156 1157 1158 1159 1160 1161
		/*
		 * Replace the primary handler which was provided from
		 * the driver for non nested interrupt handling by the
		 * dummy function which warns when called.
		 */
		new->handler = irq_nested_primary_handler;
1162
	} else {
1163 1164 1165 1166 1167
		if (irq_settings_can_thread(desc)) {
			ret = irq_setup_forced_threading(new);
			if (ret)
				goto out_mput;
		}
1168 1169
	}

1170
	/*
1171 1172 1173
	 * Create a handler thread when a thread function is supplied
	 * and the interrupt does not nest into another interrupt
	 * thread.
1174
	 */
1175
	if (new->thread_fn && !nested) {
1176 1177
		ret = setup_irq_thread(new, irq, false);
		if (ret)
1178
			goto out_mput;
1179 1180 1181 1182
		if (new->secondary) {
			ret = setup_irq_thread(new->secondary, irq, true);
			if (ret)
				goto out_thread;
1183
		}
1184 1185
	}

1186 1187 1188 1189 1190 1191 1192 1193 1194 1195 1196 1197
	/*
	 * Drivers are often written to work w/o knowledge about the
	 * underlying irq chip implementation, so a request for a
	 * threaded irq without a primary hard irq context handler
	 * requires the ONESHOT flag to be set. Some irq chips like
	 * MSI based interrupts are per se one shot safe. Check the
	 * chip flags, so we can avoid the unmask dance at the end of
	 * the threaded handler for those.
	 */
	if (desc->irq_data.chip->flags & IRQCHIP_ONESHOT_SAFE)
		new->flags &= ~IRQF_ONESHOT;

L
Linus Torvalds 已提交
1198 1199 1200
	/*
	 * The following block of code has to be executed atomically
	 */
1201
	raw_spin_lock_irqsave(&desc->lock, flags);
1202 1203
	old_ptr = &desc->action;
	old = *old_ptr;
1204
	if (old) {
1205 1206 1207
		/*
		 * Can't share interrupts unless both agree to and are
		 * the same type (level, edge, polarity). So both flag
1208
		 * fields must have IRQF_SHARED set and the bits which
1209 1210
		 * set the trigger type must match. Also all must
		 * agree on ONESHOT.
1211
		 */
1212 1213
		unsigned int oldtype = irqd_get_trigger_type(&desc->irq_data);

1214
		if (!((old->flags & new->flags) & IRQF_SHARED) ||
1215
		    (oldtype != (new->flags & IRQF_TRIGGER_MASK)) ||
1216
		    ((old->flags ^ new->flags) & IRQF_ONESHOT))
1217 1218 1219
			goto mismatch;

		/* All handlers must agree on per-cpuness */
1220 1221
		if ((old->flags & IRQF_PERCPU) !=
		    (new->flags & IRQF_PERCPU))
1222
			goto mismatch;
L
Linus Torvalds 已提交
1223 1224 1225

		/* add new interrupt at end of irq queue */
		do {
1226 1227 1228 1229 1230
			/*
			 * Or all existing action->thread_mask bits,
			 * so we can find the next zero bit for this
			 * new action.
			 */
1231
			thread_mask |= old->thread_mask;
1232 1233
			old_ptr = &old->next;
			old = *old_ptr;
L
Linus Torvalds 已提交
1234 1235 1236 1237
		} while (old);
		shared = 1;
	}

1238
	/*
1239 1240 1241
	 * Setup the thread mask for this irqaction for ONESHOT. For
	 * !ONESHOT irqs the thread mask is 0 so we can avoid a
	 * conditional in irq_wake_thread().
1242
	 */
1243 1244 1245 1246 1247 1248 1249
	if (new->flags & IRQF_ONESHOT) {
		/*
		 * Unlikely to have 32 resp 64 irqs sharing one line,
		 * but who knows.
		 */
		if (thread_mask == ~0UL) {
			ret = -EBUSY;
1250
			goto out_unlock;
1251 1252 1253 1254 1255 1256 1257 1258 1259 1260 1261 1262 1263 1264 1265 1266 1267 1268 1269 1270 1271 1272
		}
		/*
		 * The thread_mask for the action is or'ed to
		 * desc->thread_active to indicate that the
		 * IRQF_ONESHOT thread handler has been woken, but not
		 * yet finished. The bit is cleared when a thread
		 * completes. When all threads of a shared interrupt
		 * line have completed desc->threads_active becomes
		 * zero and the interrupt line is unmasked. See
		 * handle.c:irq_wake_thread() for further information.
		 *
		 * If no thread is woken by primary (hard irq context)
		 * interrupt handlers, then desc->threads_active is
		 * also checked for zero to unmask the irq line in the
		 * affected hard irq flow handlers
		 * (handle_[fasteoi|level]_irq).
		 *
		 * The new action gets the first zero bit of
		 * thread_mask assigned. See the loop above which or's
		 * all existing action->thread_mask bits.
		 */
		new->thread_mask = 1 << ffz(thread_mask);
1273

1274 1275
	} else if (new->handler == irq_default_primary_handler &&
		   !(desc->irq_data.chip->flags & IRQCHIP_ONESHOT_SAFE)) {
1276 1277 1278 1279 1280 1281 1282 1283 1284 1285 1286 1287 1288 1289 1290
		/*
		 * The interrupt was requested with handler = NULL, so
		 * we use the default primary handler for it. But it
		 * does not have the oneshot flag set. In combination
		 * with level interrupts this is deadly, because the
		 * default primary handler just wakes the thread, then
		 * the irq lines is reenabled, but the device still
		 * has the level irq asserted. Rinse and repeat....
		 *
		 * While this works for edge type interrupts, we play
		 * it safe and reject unconditionally because we can't
		 * say for sure which type this interrupt really
		 * has. The type flags are unreliable as the
		 * underlying chip implementation can override them.
		 */
1291
		pr_err("Threaded irq requested with handler=NULL and !ONESHOT for irq %d\n",
1292 1293
		       irq);
		ret = -EINVAL;
1294
		goto out_unlock;
1295 1296
	}

L
Linus Torvalds 已提交
1297
	if (!shared) {
1298 1299 1300 1301
		ret = irq_request_resources(desc);
		if (ret) {
			pr_err("Failed to request resources for %s (irq %d) on irqchip %s\n",
			       new->name, irq, desc->irq_data.chip->name);
1302
			goto out_unlock;
1303 1304
		}

1305 1306
		init_waitqueue_head(&desc->wait_for_threads);

1307
		/* Setup the type (level, edge polarity) if configured: */
1308
		if (new->flags & IRQF_TRIGGER_MASK) {
1309 1310
			ret = __irq_set_trigger(desc,
						new->flags & IRQF_TRIGGER_MASK);
1311

1312 1313
			if (ret) {
				irq_release_resources(desc);
1314
				goto out_unlock;
1315
			}
1316
		}
T
Thomas Gleixner 已提交
1317

1318
		desc->istate &= ~(IRQS_AUTODETECT | IRQS_SPURIOUS_DISABLED | \
1319 1320
				  IRQS_ONESHOT | IRQS_WAITING);
		irqd_clear(&desc->irq_data, IRQD_IRQ_INPROGRESS);
1321

1322 1323 1324 1325
		if (new->flags & IRQF_PERCPU) {
			irqd_set(&desc->irq_data, IRQD_PER_CPU);
			irq_settings_set_per_cpu(desc);
		}
1326

T
Thomas Gleixner 已提交
1327
		if (new->flags & IRQF_ONESHOT)
1328
			desc->istate |= IRQS_ONESHOT;
T
Thomas Gleixner 已提交
1329

1330
		if (irq_settings_can_autoenable(desc)) {
1331
			irq_startup(desc, true);
1332 1333 1334 1335 1336 1337 1338 1339
		} else {
			/*
			 * Shared interrupts do not go well with disabling
			 * auto enable. The sharing interrupt might request
			 * it while it's still disabled and then wait for
			 * interrupts forever.
			 */
			WARN_ON_ONCE(new->flags & IRQF_SHARED);
1340 1341
			/* Undo nested disables: */
			desc->depth = 1;
1342
		}
1343

1344
		/* Exclude IRQ from balancing if requested */
1345 1346 1347 1348
		if (new->flags & IRQF_NOBALANCING) {
			irq_settings_set_no_balancing(desc);
			irqd_set(&desc->irq_data, IRQD_NO_BALANCING);
		}
1349

1350
		/* Set default affinity mask once everything is setup */
1351
		irq_setup_affinity(desc);
D
David Brownell 已提交
1352

1353 1354
	} else if (new->flags & IRQF_TRIGGER_MASK) {
		unsigned int nmsk = new->flags & IRQF_TRIGGER_MASK;
1355
		unsigned int omsk = irqd_get_trigger_type(&desc->irq_data);
1356 1357 1358

		if (nmsk != omsk)
			/* hope the handler works with current  trigger mode */
1359
			pr_warn("irq %d uses trigger mode %u; requested %u\n",
1360
				irq, omsk, nmsk);
L
Linus Torvalds 已提交
1361
	}
1362

1363
	*old_ptr = new;
1364

1365 1366
	irq_pm_install_action(desc, new);

1367 1368 1369
	/* Reset broken irq detection when installing new handler */
	desc->irq_count = 0;
	desc->irqs_unhandled = 0;
1370 1371 1372 1373 1374

	/*
	 * Check whether we disabled the irq via the spurious handler
	 * before. Reenable it and give it another chance.
	 */
1375 1376
	if (shared && (desc->istate & IRQS_SPURIOUS_DISABLED)) {
		desc->istate &= ~IRQS_SPURIOUS_DISABLED;
1377
		__enable_irq(desc);
1378 1379
	}

1380
	raw_spin_unlock_irqrestore(&desc->lock, flags);
L
Linus Torvalds 已提交
1381

1382 1383 1384 1385 1386 1387
	/*
	 * Strictly no need to wake it up, but hung_task complains
	 * when no hard interrupt wakes the thread up.
	 */
	if (new->thread)
		wake_up_process(new->thread);
1388 1389
	if (new->secondary)
		wake_up_process(new->secondary->thread);
1390

1391
	register_irq_proc(irq, desc);
1392
	irq_add_debugfs_entry(irq, desc);
L
Linus Torvalds 已提交
1393 1394 1395
	new->dir = NULL;
	register_handler_proc(irq, new);
	return 0;
1396 1397

mismatch:
1398
	if (!(new->flags & IRQF_PROBE_SHARED)) {
1399
		pr_err("Flags mismatch irq %d. %08x (%s) vs. %08x (%s)\n",
1400 1401
		       irq, new->flags, new->name, old->flags, old->name);
#ifdef CONFIG_DEBUG_SHIRQ
1402
		dump_stack();
1403
#endif
1404
	}
1405 1406
	ret = -EBUSY;

1407
out_unlock:
1408
	raw_spin_unlock_irqrestore(&desc->lock, flags);
1409

1410 1411 1412 1413 1414
out_thread:
	if (new->thread) {
		struct task_struct *t = new->thread;

		new->thread = NULL;
1415
		kthread_stop(t);
1416 1417
		put_task_struct(t);
	}
1418 1419 1420 1421 1422 1423 1424
	if (new->secondary && new->secondary->thread) {
		struct task_struct *t = new->secondary->thread;

		new->secondary->thread = NULL;
		kthread_stop(t);
		put_task_struct(t);
	}
1425 1426
out_mput:
	module_put(desc->owner);
1427
	return ret;
L
Linus Torvalds 已提交
1428 1429
}

1430 1431 1432 1433 1434 1435 1436 1437 1438
/**
 *	setup_irq - setup an interrupt
 *	@irq: Interrupt line to setup
 *	@act: irqaction for the interrupt
 *
 * Used to statically setup interrupts in the early boot process.
 */
int setup_irq(unsigned int irq, struct irqaction *act)
{
1439
	int retval;
1440 1441
	struct irq_desc *desc = irq_to_desc(irq);

1442
	if (!desc || WARN_ON(irq_settings_is_per_cpu_devid(desc)))
1443
		return -EINVAL;
1444 1445 1446 1447 1448

	retval = irq_chip_pm_get(&desc->irq_data);
	if (retval < 0)
		return retval;

1449 1450 1451 1452
	chip_bus_lock(desc);
	retval = __setup_irq(irq, desc, act);
	chip_bus_sync_unlock(desc);

1453 1454 1455
	if (retval)
		irq_chip_pm_put(&desc->irq_data);

1456
	return retval;
1457
}
1458
EXPORT_SYMBOL_GPL(setup_irq);
1459

1460
/*
1461 1462
 * Internal function to unregister an irqaction - used to free
 * regular and special interrupts that are part of the architecture.
L
Linus Torvalds 已提交
1463
 */
1464
static struct irqaction *__free_irq(unsigned int irq, void *dev_id)
L
Linus Torvalds 已提交
1465
{
1466
	struct irq_desc *desc = irq_to_desc(irq);
1467
	struct irqaction *action, **action_ptr;
L
Linus Torvalds 已提交
1468 1469
	unsigned long flags;

1470
	WARN(in_interrupt(), "Trying to free IRQ %d from IRQ context!\n", irq);
1471 1472

	if (!desc)
1473
		return NULL;
L
Linus Torvalds 已提交
1474

1475
	chip_bus_lock(desc);
1476
	raw_spin_lock_irqsave(&desc->lock, flags);
1477 1478 1479 1480 1481

	/*
	 * There can be multiple actions per IRQ descriptor, find the right
	 * one based on the dev_id:
	 */
1482
	action_ptr = &desc->action;
L
Linus Torvalds 已提交
1483
	for (;;) {
1484
		action = *action_ptr;
L
Linus Torvalds 已提交
1485

1486 1487
		if (!action) {
			WARN(1, "Trying to free already-free IRQ %d\n", irq);
1488
			raw_spin_unlock_irqrestore(&desc->lock, flags);
1489
			chip_bus_sync_unlock(desc);
1490
			return NULL;
1491
		}
L
Linus Torvalds 已提交
1492

1493 1494
		if (action->dev_id == dev_id)
			break;
1495
		action_ptr = &action->next;
1496
	}
1497

1498
	/* Found it - now remove it from the list of entries: */
1499
	*action_ptr = action->next;
1500

1501 1502
	irq_pm_remove_action(desc, action);

1503
	/* If this was the last handler, shut down the IRQ line: */
1504
	if (!desc->action) {
1505
		irq_settings_clr_disable_unlazy(desc);
1506
		irq_shutdown(desc);
1507 1508
		irq_release_resources(desc);
	}
1509

1510 1511 1512 1513 1514 1515
#ifdef CONFIG_SMP
	/* make sure affinity_hint is cleaned up */
	if (WARN_ON_ONCE(desc->affinity_hint))
		desc->affinity_hint = NULL;
#endif

1516
	raw_spin_unlock_irqrestore(&desc->lock, flags);
1517
	chip_bus_sync_unlock(desc);
1518 1519 1520 1521 1522

	unregister_handler_proc(irq, action);

	/* Make sure it's not being used on another CPU: */
	synchronize_irq(irq);
L
Linus Torvalds 已提交
1523

1524
#ifdef CONFIG_DEBUG_SHIRQ
1525 1526 1527 1528 1529 1530 1531 1532 1533 1534 1535 1536
	/*
	 * It's a shared IRQ -- the driver ought to be prepared for an IRQ
	 * event to happen even now it's being freed, so let's make sure that
	 * is so by doing an extra call to the handler ....
	 *
	 * ( We do this after actually deregistering it, to make sure that a
	 *   'real' IRQ doesn't run in * parallel with our fake. )
	 */
	if (action->flags & IRQF_SHARED) {
		local_irq_save(flags);
		action->handler(irq, dev_id);
		local_irq_restore(flags);
L
Linus Torvalds 已提交
1537
	}
1538
#endif
1539 1540

	if (action->thread) {
1541
		kthread_stop(action->thread);
1542
		put_task_struct(action->thread);
1543 1544 1545 1546
		if (action->secondary && action->secondary->thread) {
			kthread_stop(action->secondary->thread);
			put_task_struct(action->secondary->thread);
		}
1547 1548
	}

1549
	irq_chip_pm_put(&desc->irq_data);
1550
	module_put(desc->owner);
1551
	kfree(action->secondary);
1552 1553 1554
	return action;
}

1555 1556 1557 1558 1559 1560 1561 1562 1563
/**
 *	remove_irq - free an interrupt
 *	@irq: Interrupt line to free
 *	@act: irqaction for the interrupt
 *
 * Used to remove interrupts statically setup by the early boot process.
 */
void remove_irq(unsigned int irq, struct irqaction *act)
{
1564 1565 1566
	struct irq_desc *desc = irq_to_desc(irq);

	if (desc && !WARN_ON(irq_settings_is_per_cpu_devid(desc)))
1567
		__free_irq(irq, act->dev_id);
1568
}
1569
EXPORT_SYMBOL_GPL(remove_irq);
1570

1571 1572 1573 1574 1575 1576 1577 1578 1579 1580 1581 1582 1583
/**
 *	free_irq - free an interrupt allocated with request_irq
 *	@irq: Interrupt line to free
 *	@dev_id: Device identity to free
 *
 *	Remove an interrupt handler. The handler is removed and if the
 *	interrupt line is no longer in use by any driver it is disabled.
 *	On a shared IRQ the caller must ensure the interrupt is disabled
 *	on the card it drives before calling this function. The function
 *	does not return until any executing interrupts for this IRQ
 *	have completed.
 *
 *	This function must not be called from interrupt context.
1584 1585
 *
 *	Returns the devname argument passed to request_irq.
1586
 */
1587
const void *free_irq(unsigned int irq, void *dev_id)
1588
{
T
Thomas Gleixner 已提交
1589
	struct irq_desc *desc = irq_to_desc(irq);
1590 1591
	struct irqaction *action;
	const char *devname;
T
Thomas Gleixner 已提交
1592

1593
	if (!desc || WARN_ON(irq_settings_is_per_cpu_devid(desc)))
1594
		return NULL;
T
Thomas Gleixner 已提交
1595

1596 1597 1598 1599 1600
#ifdef CONFIG_SMP
	if (WARN_ON(desc->affinity_notify))
		desc->affinity_notify = NULL;
#endif

1601 1602 1603 1604
	action = __free_irq(irq, dev_id);
	devname = action->name;
	kfree(action);
	return devname;
L
Linus Torvalds 已提交
1605 1606 1607 1608
}
EXPORT_SYMBOL(free_irq);

/**
1609
 *	request_threaded_irq - allocate an interrupt line
L
Linus Torvalds 已提交
1610
 *	@irq: Interrupt line to allocate
1611 1612
 *	@handler: Function to be called when the IRQ occurs.
 *		  Primary handler for threaded interrupts
T
Thomas Gleixner 已提交
1613 1614
 *		  If NULL and thread_fn != NULL the default
 *		  primary handler is installed
1615 1616
 *	@thread_fn: Function called from the irq handler thread
 *		    If NULL, no irq thread is created
L
Linus Torvalds 已提交
1617 1618 1619 1620 1621 1622 1623 1624 1625 1626 1627
 *	@irqflags: Interrupt type flags
 *	@devname: An ascii name for the claiming device
 *	@dev_id: A cookie passed back to the handler function
 *
 *	This call allocates interrupt resources and enables the
 *	interrupt line and IRQ handling. From the point this
 *	call is made your handler function may be invoked. Since
 *	your handler function must clear any interrupt the board
 *	raises, you must take care both to initialise your hardware
 *	and to set up the interrupt handler in the right order.
 *
1628
 *	If you want to set up a threaded irq handler for your device
J
Javi Merino 已提交
1629
 *	then you need to supply @handler and @thread_fn. @handler is
1630 1631 1632
 *	still called in hard interrupt context and has to check
 *	whether the interrupt originates from the device. If yes it
 *	needs to disable the interrupt on the device and return
1633
 *	IRQ_WAKE_THREAD which will wake up the handler thread and run
1634 1635 1636
 *	@thread_fn. This split handler design is necessary to support
 *	shared interrupts.
 *
L
Linus Torvalds 已提交
1637 1638 1639 1640 1641 1642 1643 1644 1645
 *	Dev_id must be globally unique. Normally the address of the
 *	device data structure is used as the cookie. Since the handler
 *	receives this value it makes sense to use it.
 *
 *	If your interrupt is shared you must pass a non NULL dev_id
 *	as this is required when freeing the interrupt.
 *
 *	Flags:
 *
1646
 *	IRQF_SHARED		Interrupt is shared
D
David Brownell 已提交
1647
 *	IRQF_TRIGGER_*		Specify active edge(s) or level
L
Linus Torvalds 已提交
1648 1649
 *
 */
1650 1651 1652
int request_threaded_irq(unsigned int irq, irq_handler_t handler,
			 irq_handler_t thread_fn, unsigned long irqflags,
			 const char *devname, void *dev_id)
L
Linus Torvalds 已提交
1653
{
1654
	struct irqaction *action;
1655
	struct irq_desc *desc;
1656
	int retval;
L
Linus Torvalds 已提交
1657

1658 1659 1660
	if (irq == IRQ_NOTCONNECTED)
		return -ENOTCONN;

L
Linus Torvalds 已提交
1661 1662 1663 1664 1665
	/*
	 * Sanity-check: shared interrupts must pass in a real dev-ID,
	 * otherwise we'll have trouble later trying to figure out
	 * which interrupt is which (messes up the interrupt freeing
	 * logic etc).
1666 1667 1668
	 *
	 * Also IRQF_COND_SUSPEND only makes sense for shared interrupts and
	 * it cannot be set along with IRQF_NO_SUSPEND.
L
Linus Torvalds 已提交
1669
	 */
1670 1671 1672
	if (((irqflags & IRQF_SHARED) && !dev_id) ||
	    (!(irqflags & IRQF_SHARED) && (irqflags & IRQF_COND_SUSPEND)) ||
	    ((irqflags & IRQF_NO_SUSPEND) && (irqflags & IRQF_COND_SUSPEND)))
L
Linus Torvalds 已提交
1673
		return -EINVAL;
1674

1675
	desc = irq_to_desc(irq);
1676
	if (!desc)
L
Linus Torvalds 已提交
1677
		return -EINVAL;
1678

1679 1680
	if (!irq_settings_can_request(desc) ||
	    WARN_ON(irq_settings_is_per_cpu_devid(desc)))
1681
		return -EINVAL;
T
Thomas Gleixner 已提交
1682 1683 1684 1685 1686 1687

	if (!handler) {
		if (!thread_fn)
			return -EINVAL;
		handler = irq_default_primary_handler;
	}
L
Linus Torvalds 已提交
1688

1689
	action = kzalloc(sizeof(struct irqaction), GFP_KERNEL);
L
Linus Torvalds 已提交
1690 1691 1692 1693
	if (!action)
		return -ENOMEM;

	action->handler = handler;
1694
	action->thread_fn = thread_fn;
L
Linus Torvalds 已提交
1695 1696 1697 1698
	action->flags = irqflags;
	action->name = devname;
	action->dev_id = dev_id;

1699
	retval = irq_chip_pm_get(&desc->irq_data);
1700 1701
	if (retval < 0) {
		kfree(action);
1702
		return retval;
1703
	}
1704

1705
	chip_bus_lock(desc);
1706
	retval = __setup_irq(irq, desc, action);
1707
	chip_bus_sync_unlock(desc);
T
Thomas Gleixner 已提交
1708

1709
	if (retval) {
1710
		irq_chip_pm_put(&desc->irq_data);
1711
		kfree(action->secondary);
1712
		kfree(action);
1713
	}
1714

1715
#ifdef CONFIG_DEBUG_SHIRQ_FIXME
1716
	if (!retval && (irqflags & IRQF_SHARED)) {
D
David Woodhouse 已提交
1717 1718 1719
		/*
		 * It's a shared IRQ -- the driver ought to be prepared for it
		 * to happen immediately, so let's make sure....
1720 1721
		 * We disable the irq to make sure that a 'real' IRQ doesn't
		 * run in parallel with our fake.
D
David Woodhouse 已提交
1722
		 */
1723
		unsigned long flags;
D
David Woodhouse 已提交
1724

1725
		disable_irq(irq);
1726
		local_irq_save(flags);
1727

1728
		handler(irq, dev_id);
1729

1730
		local_irq_restore(flags);
1731
		enable_irq(irq);
D
David Woodhouse 已提交
1732 1733
	}
#endif
L
Linus Torvalds 已提交
1734 1735
	return retval;
}
1736
EXPORT_SYMBOL(request_threaded_irq);
1737 1738 1739 1740 1741 1742 1743 1744 1745 1746 1747 1748 1749 1750 1751 1752 1753 1754 1755 1756 1757

/**
 *	request_any_context_irq - allocate an interrupt line
 *	@irq: Interrupt line to allocate
 *	@handler: Function to be called when the IRQ occurs.
 *		  Threaded handler for threaded interrupts.
 *	@flags: Interrupt type flags
 *	@name: An ascii name for the claiming device
 *	@dev_id: A cookie passed back to the handler function
 *
 *	This call allocates interrupt resources and enables the
 *	interrupt line and IRQ handling. It selects either a
 *	hardirq or threaded handling method depending on the
 *	context.
 *
 *	On failure, it returns a negative value. On success,
 *	it returns either IRQC_IS_HARDIRQ or IRQC_IS_NESTED.
 */
int request_any_context_irq(unsigned int irq, irq_handler_t handler,
			    unsigned long flags, const char *name, void *dev_id)
{
1758
	struct irq_desc *desc;
1759 1760
	int ret;

1761 1762 1763 1764
	if (irq == IRQ_NOTCONNECTED)
		return -ENOTCONN;

	desc = irq_to_desc(irq);
1765 1766 1767
	if (!desc)
		return -EINVAL;

1768
	if (irq_settings_is_nested_thread(desc)) {
1769 1770 1771 1772 1773 1774 1775 1776 1777
		ret = request_threaded_irq(irq, NULL, handler,
					   flags, name, dev_id);
		return !ret ? IRQC_IS_NESTED : ret;
	}

	ret = request_irq(irq, handler, flags, name, dev_id);
	return !ret ? IRQC_IS_HARDIRQ : ret;
}
EXPORT_SYMBOL_GPL(request_any_context_irq);
1778

1779
void enable_percpu_irq(unsigned int irq, unsigned int type)
1780 1781 1782 1783 1784 1785 1786 1787
{
	unsigned int cpu = smp_processor_id();
	unsigned long flags;
	struct irq_desc *desc = irq_get_desc_lock(irq, &flags, IRQ_GET_DESC_CHECK_PERCPU);

	if (!desc)
		return;

1788 1789 1790 1791
	/*
	 * If the trigger type is not specified by the caller, then
	 * use the default for this interrupt.
	 */
1792
	type &= IRQ_TYPE_SENSE_MASK;
1793 1794 1795
	if (type == IRQ_TYPE_NONE)
		type = irqd_get_trigger_type(&desc->irq_data);

1796 1797 1798
	if (type != IRQ_TYPE_NONE) {
		int ret;

1799
		ret = __irq_set_trigger(desc, type);
1800 1801

		if (ret) {
1802
			WARN(1, "failed to set type for IRQ%d\n", irq);
1803 1804 1805 1806
			goto out;
		}
	}

1807
	irq_percpu_enable(desc, cpu);
1808
out:
1809 1810
	irq_put_desc_unlock(desc, flags);
}
1811
EXPORT_SYMBOL_GPL(enable_percpu_irq);
1812

1813 1814 1815 1816 1817 1818 1819 1820 1821 1822 1823 1824 1825 1826 1827 1828 1829 1830 1831 1832 1833 1834 1835 1836 1837
/**
 * irq_percpu_is_enabled - Check whether the per cpu irq is enabled
 * @irq:	Linux irq number to check for
 *
 * Must be called from a non migratable context. Returns the enable
 * state of a per cpu interrupt on the current cpu.
 */
bool irq_percpu_is_enabled(unsigned int irq)
{
	unsigned int cpu = smp_processor_id();
	struct irq_desc *desc;
	unsigned long flags;
	bool is_enabled;

	desc = irq_get_desc_lock(irq, &flags, IRQ_GET_DESC_CHECK_PERCPU);
	if (!desc)
		return false;

	is_enabled = cpumask_test_cpu(cpu, desc->percpu_enabled);
	irq_put_desc_unlock(desc, flags);

	return is_enabled;
}
EXPORT_SYMBOL_GPL(irq_percpu_is_enabled);

1838 1839 1840 1841 1842 1843 1844 1845 1846 1847 1848 1849
void disable_percpu_irq(unsigned int irq)
{
	unsigned int cpu = smp_processor_id();
	unsigned long flags;
	struct irq_desc *desc = irq_get_desc_lock(irq, &flags, IRQ_GET_DESC_CHECK_PERCPU);

	if (!desc)
		return;

	irq_percpu_disable(desc, cpu);
	irq_put_desc_unlock(desc, flags);
}
1850
EXPORT_SYMBOL_GPL(disable_percpu_irq);
1851 1852 1853 1854 1855 1856 1857 1858 1859 1860 1861 1862 1863 1864 1865 1866 1867 1868 1869 1870 1871 1872 1873 1874 1875 1876 1877 1878 1879 1880 1881 1882 1883 1884 1885 1886

/*
 * Internal function to unregister a percpu irqaction.
 */
static struct irqaction *__free_percpu_irq(unsigned int irq, void __percpu *dev_id)
{
	struct irq_desc *desc = irq_to_desc(irq);
	struct irqaction *action;
	unsigned long flags;

	WARN(in_interrupt(), "Trying to free IRQ %d from IRQ context!\n", irq);

	if (!desc)
		return NULL;

	raw_spin_lock_irqsave(&desc->lock, flags);

	action = desc->action;
	if (!action || action->percpu_dev_id != dev_id) {
		WARN(1, "Trying to free already-free IRQ %d\n", irq);
		goto bad;
	}

	if (!cpumask_empty(desc->percpu_enabled)) {
		WARN(1, "percpu IRQ %d still enabled on CPU%d!\n",
		     irq, cpumask_first(desc->percpu_enabled));
		goto bad;
	}

	/* Found it - now remove it from the list of entries: */
	desc->action = NULL;

	raw_spin_unlock_irqrestore(&desc->lock, flags);

	unregister_handler_proc(irq, action);

1887
	irq_chip_pm_put(&desc->irq_data);
1888 1889 1890 1891 1892 1893 1894 1895 1896 1897 1898 1899 1900 1901 1902 1903 1904 1905 1906 1907 1908 1909 1910 1911 1912 1913 1914 1915 1916 1917 1918 1919 1920 1921 1922 1923 1924 1925 1926 1927 1928 1929 1930 1931 1932 1933
	module_put(desc->owner);
	return action;

bad:
	raw_spin_unlock_irqrestore(&desc->lock, flags);
	return NULL;
}

/**
 *	remove_percpu_irq - free a per-cpu interrupt
 *	@irq: Interrupt line to free
 *	@act: irqaction for the interrupt
 *
 * Used to remove interrupts statically setup by the early boot process.
 */
void remove_percpu_irq(unsigned int irq, struct irqaction *act)
{
	struct irq_desc *desc = irq_to_desc(irq);

	if (desc && irq_settings_is_per_cpu_devid(desc))
	    __free_percpu_irq(irq, act->percpu_dev_id);
}

/**
 *	free_percpu_irq - free an interrupt allocated with request_percpu_irq
 *	@irq: Interrupt line to free
 *	@dev_id: Device identity to free
 *
 *	Remove a percpu interrupt handler. The handler is removed, but
 *	the interrupt line is not disabled. This must be done on each
 *	CPU before calling this function. The function does not return
 *	until any executing interrupts for this IRQ have completed.
 *
 *	This function must not be called from interrupt context.
 */
void free_percpu_irq(unsigned int irq, void __percpu *dev_id)
{
	struct irq_desc *desc = irq_to_desc(irq);

	if (!desc || !irq_settings_is_per_cpu_devid(desc))
		return;

	chip_bus_lock(desc);
	kfree(__free_percpu_irq(irq, dev_id));
	chip_bus_sync_unlock(desc);
}
1934
EXPORT_SYMBOL_GPL(free_percpu_irq);
1935 1936 1937 1938 1939 1940 1941 1942 1943 1944 1945 1946 1947 1948 1949

/**
 *	setup_percpu_irq - setup a per-cpu interrupt
 *	@irq: Interrupt line to setup
 *	@act: irqaction for the interrupt
 *
 * Used to statically setup per-cpu interrupts in the early boot process.
 */
int setup_percpu_irq(unsigned int irq, struct irqaction *act)
{
	struct irq_desc *desc = irq_to_desc(irq);
	int retval;

	if (!desc || !irq_settings_is_per_cpu_devid(desc))
		return -EINVAL;
1950 1951 1952 1953 1954

	retval = irq_chip_pm_get(&desc->irq_data);
	if (retval < 0)
		return retval;

1955 1956 1957 1958
	chip_bus_lock(desc);
	retval = __setup_irq(irq, desc, act);
	chip_bus_sync_unlock(desc);

1959 1960 1961
	if (retval)
		irq_chip_pm_put(&desc->irq_data);

1962 1963 1964 1965 1966 1967 1968 1969 1970 1971
	return retval;
}

/**
 *	request_percpu_irq - allocate a percpu interrupt line
 *	@irq: Interrupt line to allocate
 *	@handler: Function to be called when the IRQ occurs.
 *	@devname: An ascii name for the claiming device
 *	@dev_id: A percpu cookie passed back to the handler function
 *
1972 1973 1974 1975
 *	This call allocates interrupt resources and enables the
 *	interrupt on the local CPU. If the interrupt is supposed to be
 *	enabled on other CPUs, it has to be done on each CPU using
 *	enable_percpu_irq().
1976 1977 1978 1979 1980 1981 1982 1983 1984 1985 1986 1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000
 *
 *	Dev_id must be globally unique. It is a per-cpu variable, and
 *	the handler gets called with the interrupted CPU's instance of
 *	that variable.
 */
int request_percpu_irq(unsigned int irq, irq_handler_t handler,
		       const char *devname, void __percpu *dev_id)
{
	struct irqaction *action;
	struct irq_desc *desc;
	int retval;

	if (!dev_id)
		return -EINVAL;

	desc = irq_to_desc(irq);
	if (!desc || !irq_settings_can_request(desc) ||
	    !irq_settings_is_per_cpu_devid(desc))
		return -EINVAL;

	action = kzalloc(sizeof(struct irqaction), GFP_KERNEL);
	if (!action)
		return -ENOMEM;

	action->handler = handler;
2001
	action->flags = IRQF_PERCPU | IRQF_NO_SUSPEND;
2002 2003 2004
	action->name = devname;
	action->percpu_dev_id = dev_id;

2005
	retval = irq_chip_pm_get(&desc->irq_data);
2006 2007
	if (retval < 0) {
		kfree(action);
2008
		return retval;
2009
	}
2010

2011 2012 2013 2014
	chip_bus_lock(desc);
	retval = __setup_irq(irq, desc, action);
	chip_bus_sync_unlock(desc);

2015 2016
	if (retval) {
		irq_chip_pm_put(&desc->irq_data);
2017
		kfree(action);
2018
	}
2019 2020 2021

	return retval;
}
2022
EXPORT_SYMBOL_GPL(request_percpu_irq);
2023 2024 2025 2026 2027 2028 2029 2030 2031 2032 2033 2034 2035 2036 2037 2038 2039 2040 2041 2042 2043 2044 2045 2046 2047 2048 2049 2050 2051 2052 2053 2054 2055 2056 2057 2058 2059 2060 2061 2062 2063 2064 2065 2066 2067 2068

/**
 *	irq_get_irqchip_state - returns the irqchip state of a interrupt.
 *	@irq: Interrupt line that is forwarded to a VM
 *	@which: One of IRQCHIP_STATE_* the caller wants to know about
 *	@state: a pointer to a boolean where the state is to be storeed
 *
 *	This call snapshots the internal irqchip state of an
 *	interrupt, returning into @state the bit corresponding to
 *	stage @which
 *
 *	This function should be called with preemption disabled if the
 *	interrupt controller has per-cpu registers.
 */
int irq_get_irqchip_state(unsigned int irq, enum irqchip_irq_state which,
			  bool *state)
{
	struct irq_desc *desc;
	struct irq_data *data;
	struct irq_chip *chip;
	unsigned long flags;
	int err = -EINVAL;

	desc = irq_get_desc_buslock(irq, &flags, 0);
	if (!desc)
		return err;

	data = irq_desc_get_irq_data(desc);

	do {
		chip = irq_data_get_irq_chip(data);
		if (chip->irq_get_irqchip_state)
			break;
#ifdef CONFIG_IRQ_DOMAIN_HIERARCHY
		data = data->parent_data;
#else
		data = NULL;
#endif
	} while (data);

	if (data)
		err = chip->irq_get_irqchip_state(data, which, state);

	irq_put_desc_busunlock(desc, flags);
	return err;
}
2069
EXPORT_SYMBOL_GPL(irq_get_irqchip_state);
2070 2071 2072 2073 2074 2075 2076 2077 2078 2079 2080 2081 2082 2083 2084 2085 2086 2087 2088 2089 2090 2091 2092 2093 2094 2095 2096 2097 2098 2099 2100 2101 2102 2103 2104 2105 2106 2107 2108 2109 2110 2111 2112 2113 2114

/**
 *	irq_set_irqchip_state - set the state of a forwarded interrupt.
 *	@irq: Interrupt line that is forwarded to a VM
 *	@which: State to be restored (one of IRQCHIP_STATE_*)
 *	@val: Value corresponding to @which
 *
 *	This call sets the internal irqchip state of an interrupt,
 *	depending on the value of @which.
 *
 *	This function should be called with preemption disabled if the
 *	interrupt controller has per-cpu registers.
 */
int irq_set_irqchip_state(unsigned int irq, enum irqchip_irq_state which,
			  bool val)
{
	struct irq_desc *desc;
	struct irq_data *data;
	struct irq_chip *chip;
	unsigned long flags;
	int err = -EINVAL;

	desc = irq_get_desc_buslock(irq, &flags, 0);
	if (!desc)
		return err;

	data = irq_desc_get_irq_data(desc);

	do {
		chip = irq_data_get_irq_chip(data);
		if (chip->irq_set_irqchip_state)
			break;
#ifdef CONFIG_IRQ_DOMAIN_HIERARCHY
		data = data->parent_data;
#else
		data = NULL;
#endif
	} while (data);

	if (data)
		err = chip->irq_set_irqchip_state(data, which, val);

	irq_put_desc_busunlock(desc, flags);
	return err;
}
2115
EXPORT_SYMBOL_GPL(irq_set_irqchip_state);