xref: /openbmc/linux/kernel/irq/chip.c (revision e1f7c9ee)
1 /*
2  * linux/kernel/irq/chip.c
3  *
4  * Copyright (C) 1992, 1998-2006 Linus Torvalds, Ingo Molnar
5  * Copyright (C) 2005-2006, Thomas Gleixner, Russell King
6  *
7  * This file contains the core interrupt handling code, for irq-chip
8  * based architectures.
9  *
10  * Detailed information is available in Documentation/DocBook/genericirq
11  */
12 
13 #include <linux/irq.h>
14 #include <linux/msi.h>
15 #include <linux/module.h>
16 #include <linux/interrupt.h>
17 #include <linux/kernel_stat.h>
18 
19 #include <trace/events/irq.h>
20 
21 #include "internals.h"
22 
23 /**
24  *	irq_set_chip - set the irq chip for an irq
25  *	@irq:	irq number
26  *	@chip:	pointer to irq chip description structure
27  */
28 int irq_set_chip(unsigned int irq, struct irq_chip *chip)
29 {
30 	unsigned long flags;
31 	struct irq_desc *desc = irq_get_desc_lock(irq, &flags, 0);
32 
33 	if (!desc)
34 		return -EINVAL;
35 
36 	if (!chip)
37 		chip = &no_irq_chip;
38 
39 	desc->irq_data.chip = chip;
40 	irq_put_desc_unlock(desc, flags);
41 	/*
42 	 * For !CONFIG_SPARSE_IRQ make the irq show up in
43 	 * allocated_irqs.
44 	 */
45 	irq_mark_irq(irq);
46 	return 0;
47 }
48 EXPORT_SYMBOL(irq_set_chip);
49 
50 /**
51  *	irq_set_type - set the irq trigger type for an irq
52  *	@irq:	irq number
53  *	@type:	IRQ_TYPE_{LEVEL,EDGE}_* value - see include/linux/irq.h
54  */
55 int irq_set_irq_type(unsigned int irq, unsigned int type)
56 {
57 	unsigned long flags;
58 	struct irq_desc *desc = irq_get_desc_buslock(irq, &flags, IRQ_GET_DESC_CHECK_GLOBAL);
59 	int ret = 0;
60 
61 	if (!desc)
62 		return -EINVAL;
63 
64 	type &= IRQ_TYPE_SENSE_MASK;
65 	ret = __irq_set_trigger(desc, irq, type);
66 	irq_put_desc_busunlock(desc, flags);
67 	return ret;
68 }
69 EXPORT_SYMBOL(irq_set_irq_type);
70 
71 /**
72  *	irq_set_handler_data - set irq handler data for an irq
73  *	@irq:	Interrupt number
74  *	@data:	Pointer to interrupt specific data
75  *
76  *	Set the hardware irq controller data for an irq
77  */
78 int irq_set_handler_data(unsigned int irq, void *data)
79 {
80 	unsigned long flags;
81 	struct irq_desc *desc = irq_get_desc_lock(irq, &flags, 0);
82 
83 	if (!desc)
84 		return -EINVAL;
85 	desc->irq_data.handler_data = data;
86 	irq_put_desc_unlock(desc, flags);
87 	return 0;
88 }
89 EXPORT_SYMBOL(irq_set_handler_data);
90 
91 /**
92  *	irq_set_msi_desc_off - set MSI descriptor data for an irq at offset
93  *	@irq_base:	Interrupt number base
94  *	@irq_offset:	Interrupt number offset
95  *	@entry:		Pointer to MSI descriptor data
96  *
97  *	Set the MSI descriptor entry for an irq at offset
98  */
99 int irq_set_msi_desc_off(unsigned int irq_base, unsigned int irq_offset,
100 			 struct msi_desc *entry)
101 {
102 	unsigned long flags;
103 	struct irq_desc *desc = irq_get_desc_lock(irq_base + irq_offset, &flags, IRQ_GET_DESC_CHECK_GLOBAL);
104 
105 	if (!desc)
106 		return -EINVAL;
107 	desc->irq_data.msi_desc = entry;
108 	if (entry && !irq_offset)
109 		entry->irq = irq_base;
110 	irq_put_desc_unlock(desc, flags);
111 	return 0;
112 }
113 
114 /**
115  *	irq_set_msi_desc - set MSI descriptor data for an irq
116  *	@irq:	Interrupt number
117  *	@entry:	Pointer to MSI descriptor data
118  *
119  *	Set the MSI descriptor entry for an irq
120  */
121 int irq_set_msi_desc(unsigned int irq, struct msi_desc *entry)
122 {
123 	return irq_set_msi_desc_off(irq, 0, entry);
124 }
125 
126 /**
127  *	irq_set_chip_data - set irq chip data for an irq
128  *	@irq:	Interrupt number
129  *	@data:	Pointer to chip specific data
130  *
131  *	Set the hardware irq chip data for an irq
132  */
133 int irq_set_chip_data(unsigned int irq, void *data)
134 {
135 	unsigned long flags;
136 	struct irq_desc *desc = irq_get_desc_lock(irq, &flags, 0);
137 
138 	if (!desc)
139 		return -EINVAL;
140 	desc->irq_data.chip_data = data;
141 	irq_put_desc_unlock(desc, flags);
142 	return 0;
143 }
144 EXPORT_SYMBOL(irq_set_chip_data);
145 
146 struct irq_data *irq_get_irq_data(unsigned int irq)
147 {
148 	struct irq_desc *desc = irq_to_desc(irq);
149 
150 	return desc ? &desc->irq_data : NULL;
151 }
152 EXPORT_SYMBOL_GPL(irq_get_irq_data);
153 
154 static void irq_state_clr_disabled(struct irq_desc *desc)
155 {
156 	irqd_clear(&desc->irq_data, IRQD_IRQ_DISABLED);
157 }
158 
159 static void irq_state_set_disabled(struct irq_desc *desc)
160 {
161 	irqd_set(&desc->irq_data, IRQD_IRQ_DISABLED);
162 }
163 
164 static void irq_state_clr_masked(struct irq_desc *desc)
165 {
166 	irqd_clear(&desc->irq_data, IRQD_IRQ_MASKED);
167 }
168 
169 static void irq_state_set_masked(struct irq_desc *desc)
170 {
171 	irqd_set(&desc->irq_data, IRQD_IRQ_MASKED);
172 }
173 
174 int irq_startup(struct irq_desc *desc, bool resend)
175 {
176 	int ret = 0;
177 
178 	irq_state_clr_disabled(desc);
179 	desc->depth = 0;
180 
181 	if (desc->irq_data.chip->irq_startup) {
182 		ret = desc->irq_data.chip->irq_startup(&desc->irq_data);
183 		irq_state_clr_masked(desc);
184 	} else {
185 		irq_enable(desc);
186 	}
187 	if (resend)
188 		check_irq_resend(desc, desc->irq_data.irq);
189 	return ret;
190 }
191 
192 void irq_shutdown(struct irq_desc *desc)
193 {
194 	irq_state_set_disabled(desc);
195 	desc->depth = 1;
196 	if (desc->irq_data.chip->irq_shutdown)
197 		desc->irq_data.chip->irq_shutdown(&desc->irq_data);
198 	else if (desc->irq_data.chip->irq_disable)
199 		desc->irq_data.chip->irq_disable(&desc->irq_data);
200 	else
201 		desc->irq_data.chip->irq_mask(&desc->irq_data);
202 	irq_state_set_masked(desc);
203 }
204 
205 void irq_enable(struct irq_desc *desc)
206 {
207 	irq_state_clr_disabled(desc);
208 	if (desc->irq_data.chip->irq_enable)
209 		desc->irq_data.chip->irq_enable(&desc->irq_data);
210 	else
211 		desc->irq_data.chip->irq_unmask(&desc->irq_data);
212 	irq_state_clr_masked(desc);
213 }
214 
215 /**
216  * irq_disable - Mark interrupt disabled
217  * @desc:	irq descriptor which should be disabled
218  *
219  * If the chip does not implement the irq_disable callback, we
220  * use a lazy disable approach. That means we mark the interrupt
221  * disabled, but leave the hardware unmasked. That's an
222  * optimization because we avoid the hardware access for the
223  * common case where no interrupt happens after we marked it
224  * disabled. If an interrupt happens, then the interrupt flow
225  * handler masks the line at the hardware level and marks it
226  * pending.
227  */
228 void irq_disable(struct irq_desc *desc)
229 {
230 	irq_state_set_disabled(desc);
231 	if (desc->irq_data.chip->irq_disable) {
232 		desc->irq_data.chip->irq_disable(&desc->irq_data);
233 		irq_state_set_masked(desc);
234 	}
235 }
236 
237 void irq_percpu_enable(struct irq_desc *desc, unsigned int cpu)
238 {
239 	if (desc->irq_data.chip->irq_enable)
240 		desc->irq_data.chip->irq_enable(&desc->irq_data);
241 	else
242 		desc->irq_data.chip->irq_unmask(&desc->irq_data);
243 	cpumask_set_cpu(cpu, desc->percpu_enabled);
244 }
245 
246 void irq_percpu_disable(struct irq_desc *desc, unsigned int cpu)
247 {
248 	if (desc->irq_data.chip->irq_disable)
249 		desc->irq_data.chip->irq_disable(&desc->irq_data);
250 	else
251 		desc->irq_data.chip->irq_mask(&desc->irq_data);
252 	cpumask_clear_cpu(cpu, desc->percpu_enabled);
253 }
254 
255 static inline void mask_ack_irq(struct irq_desc *desc)
256 {
257 	if (desc->irq_data.chip->irq_mask_ack)
258 		desc->irq_data.chip->irq_mask_ack(&desc->irq_data);
259 	else {
260 		desc->irq_data.chip->irq_mask(&desc->irq_data);
261 		if (desc->irq_data.chip->irq_ack)
262 			desc->irq_data.chip->irq_ack(&desc->irq_data);
263 	}
264 	irq_state_set_masked(desc);
265 }
266 
267 void mask_irq(struct irq_desc *desc)
268 {
269 	if (desc->irq_data.chip->irq_mask) {
270 		desc->irq_data.chip->irq_mask(&desc->irq_data);
271 		irq_state_set_masked(desc);
272 	}
273 }
274 
275 void unmask_irq(struct irq_desc *desc)
276 {
277 	if (desc->irq_data.chip->irq_unmask) {
278 		desc->irq_data.chip->irq_unmask(&desc->irq_data);
279 		irq_state_clr_masked(desc);
280 	}
281 }
282 
283 void unmask_threaded_irq(struct irq_desc *desc)
284 {
285 	struct irq_chip *chip = desc->irq_data.chip;
286 
287 	if (chip->flags & IRQCHIP_EOI_THREADED)
288 		chip->irq_eoi(&desc->irq_data);
289 
290 	if (chip->irq_unmask) {
291 		chip->irq_unmask(&desc->irq_data);
292 		irq_state_clr_masked(desc);
293 	}
294 }
295 
296 /*
297  *	handle_nested_irq - Handle a nested irq from a irq thread
298  *	@irq:	the interrupt number
299  *
300  *	Handle interrupts which are nested into a threaded interrupt
301  *	handler. The handler function is called inside the calling
302  *	threads context.
303  */
304 void handle_nested_irq(unsigned int irq)
305 {
306 	struct irq_desc *desc = irq_to_desc(irq);
307 	struct irqaction *action;
308 	irqreturn_t action_ret;
309 
310 	might_sleep();
311 
312 	raw_spin_lock_irq(&desc->lock);
313 
314 	desc->istate &= ~(IRQS_REPLAY | IRQS_WAITING);
315 	kstat_incr_irqs_this_cpu(irq, desc);
316 
317 	action = desc->action;
318 	if (unlikely(!action || irqd_irq_disabled(&desc->irq_data))) {
319 		desc->istate |= IRQS_PENDING;
320 		goto out_unlock;
321 	}
322 
323 	irqd_set(&desc->irq_data, IRQD_IRQ_INPROGRESS);
324 	raw_spin_unlock_irq(&desc->lock);
325 
326 	action_ret = action->thread_fn(action->irq, action->dev_id);
327 	if (!noirqdebug)
328 		note_interrupt(irq, desc, action_ret);
329 
330 	raw_spin_lock_irq(&desc->lock);
331 	irqd_clear(&desc->irq_data, IRQD_IRQ_INPROGRESS);
332 
333 out_unlock:
334 	raw_spin_unlock_irq(&desc->lock);
335 }
336 EXPORT_SYMBOL_GPL(handle_nested_irq);
337 
338 static bool irq_check_poll(struct irq_desc *desc)
339 {
340 	if (!(desc->istate & IRQS_POLL_INPROGRESS))
341 		return false;
342 	return irq_wait_for_poll(desc);
343 }
344 
345 static bool irq_may_run(struct irq_desc *desc)
346 {
347 	unsigned int mask = IRQD_IRQ_INPROGRESS | IRQD_WAKEUP_ARMED;
348 
349 	/*
350 	 * If the interrupt is not in progress and is not an armed
351 	 * wakeup interrupt, proceed.
352 	 */
353 	if (!irqd_has_set(&desc->irq_data, mask))
354 		return true;
355 
356 	/*
357 	 * If the interrupt is an armed wakeup source, mark it pending
358 	 * and suspended, disable it and notify the pm core about the
359 	 * event.
360 	 */
361 	if (irq_pm_check_wakeup(desc))
362 		return false;
363 
364 	/*
365 	 * Handle a potential concurrent poll on a different core.
366 	 */
367 	return irq_check_poll(desc);
368 }
369 
370 /**
371  *	handle_simple_irq - Simple and software-decoded IRQs.
372  *	@irq:	the interrupt number
373  *	@desc:	the interrupt description structure for this irq
374  *
375  *	Simple interrupts are either sent from a demultiplexing interrupt
376  *	handler or come from hardware, where no interrupt hardware control
377  *	is necessary.
378  *
379  *	Note: The caller is expected to handle the ack, clear, mask and
380  *	unmask issues if necessary.
381  */
382 void
383 handle_simple_irq(unsigned int irq, struct irq_desc *desc)
384 {
385 	raw_spin_lock(&desc->lock);
386 
387 	if (!irq_may_run(desc))
388 		goto out_unlock;
389 
390 	desc->istate &= ~(IRQS_REPLAY | IRQS_WAITING);
391 	kstat_incr_irqs_this_cpu(irq, desc);
392 
393 	if (unlikely(!desc->action || irqd_irq_disabled(&desc->irq_data))) {
394 		desc->istate |= IRQS_PENDING;
395 		goto out_unlock;
396 	}
397 
398 	handle_irq_event(desc);
399 
400 out_unlock:
401 	raw_spin_unlock(&desc->lock);
402 }
403 EXPORT_SYMBOL_GPL(handle_simple_irq);
404 
405 /*
406  * Called unconditionally from handle_level_irq() and only for oneshot
407  * interrupts from handle_fasteoi_irq()
408  */
409 static void cond_unmask_irq(struct irq_desc *desc)
410 {
411 	/*
412 	 * We need to unmask in the following cases:
413 	 * - Standard level irq (IRQF_ONESHOT is not set)
414 	 * - Oneshot irq which did not wake the thread (caused by a
415 	 *   spurious interrupt or a primary handler handling it
416 	 *   completely).
417 	 */
418 	if (!irqd_irq_disabled(&desc->irq_data) &&
419 	    irqd_irq_masked(&desc->irq_data) && !desc->threads_oneshot)
420 		unmask_irq(desc);
421 }
422 
423 /**
424  *	handle_level_irq - Level type irq handler
425  *	@irq:	the interrupt number
426  *	@desc:	the interrupt description structure for this irq
427  *
428  *	Level type interrupts are active as long as the hardware line has
429  *	the active level. This may require to mask the interrupt and unmask
430  *	it after the associated handler has acknowledged the device, so the
431  *	interrupt line is back to inactive.
432  */
433 void
434 handle_level_irq(unsigned int irq, struct irq_desc *desc)
435 {
436 	raw_spin_lock(&desc->lock);
437 	mask_ack_irq(desc);
438 
439 	if (!irq_may_run(desc))
440 		goto out_unlock;
441 
442 	desc->istate &= ~(IRQS_REPLAY | IRQS_WAITING);
443 	kstat_incr_irqs_this_cpu(irq, desc);
444 
445 	/*
446 	 * If its disabled or no action available
447 	 * keep it masked and get out of here
448 	 */
449 	if (unlikely(!desc->action || irqd_irq_disabled(&desc->irq_data))) {
450 		desc->istate |= IRQS_PENDING;
451 		goto out_unlock;
452 	}
453 
454 	handle_irq_event(desc);
455 
456 	cond_unmask_irq(desc);
457 
458 out_unlock:
459 	raw_spin_unlock(&desc->lock);
460 }
461 EXPORT_SYMBOL_GPL(handle_level_irq);
462 
463 #ifdef CONFIG_IRQ_PREFLOW_FASTEOI
464 static inline void preflow_handler(struct irq_desc *desc)
465 {
466 	if (desc->preflow_handler)
467 		desc->preflow_handler(&desc->irq_data);
468 }
469 #else
470 static inline void preflow_handler(struct irq_desc *desc) { }
471 #endif
472 
473 static void cond_unmask_eoi_irq(struct irq_desc *desc, struct irq_chip *chip)
474 {
475 	if (!(desc->istate & IRQS_ONESHOT)) {
476 		chip->irq_eoi(&desc->irq_data);
477 		return;
478 	}
479 	/*
480 	 * We need to unmask in the following cases:
481 	 * - Oneshot irq which did not wake the thread (caused by a
482 	 *   spurious interrupt or a primary handler handling it
483 	 *   completely).
484 	 */
485 	if (!irqd_irq_disabled(&desc->irq_data) &&
486 	    irqd_irq_masked(&desc->irq_data) && !desc->threads_oneshot) {
487 		chip->irq_eoi(&desc->irq_data);
488 		unmask_irq(desc);
489 	} else if (!(chip->flags & IRQCHIP_EOI_THREADED)) {
490 		chip->irq_eoi(&desc->irq_data);
491 	}
492 }
493 
494 /**
495  *	handle_fasteoi_irq - irq handler for transparent controllers
496  *	@irq:	the interrupt number
497  *	@desc:	the interrupt description structure for this irq
498  *
499  *	Only a single callback will be issued to the chip: an ->eoi()
500  *	call when the interrupt has been serviced. This enables support
501  *	for modern forms of interrupt handlers, which handle the flow
502  *	details in hardware, transparently.
503  */
504 void
505 handle_fasteoi_irq(unsigned int irq, struct irq_desc *desc)
506 {
507 	struct irq_chip *chip = desc->irq_data.chip;
508 
509 	raw_spin_lock(&desc->lock);
510 
511 	if (!irq_may_run(desc))
512 		goto out;
513 
514 	desc->istate &= ~(IRQS_REPLAY | IRQS_WAITING);
515 	kstat_incr_irqs_this_cpu(irq, desc);
516 
517 	/*
518 	 * If its disabled or no action available
519 	 * then mask it and get out of here:
520 	 */
521 	if (unlikely(!desc->action || irqd_irq_disabled(&desc->irq_data))) {
522 		desc->istate |= IRQS_PENDING;
523 		mask_irq(desc);
524 		goto out;
525 	}
526 
527 	if (desc->istate & IRQS_ONESHOT)
528 		mask_irq(desc);
529 
530 	preflow_handler(desc);
531 	handle_irq_event(desc);
532 
533 	cond_unmask_eoi_irq(desc, chip);
534 
535 	raw_spin_unlock(&desc->lock);
536 	return;
537 out:
538 	if (!(chip->flags & IRQCHIP_EOI_IF_HANDLED))
539 		chip->irq_eoi(&desc->irq_data);
540 	raw_spin_unlock(&desc->lock);
541 }
542 EXPORT_SYMBOL_GPL(handle_fasteoi_irq);
543 
544 /**
545  *	handle_edge_irq - edge type IRQ handler
546  *	@irq:	the interrupt number
547  *	@desc:	the interrupt description structure for this irq
548  *
549  *	Interrupt occures on the falling and/or rising edge of a hardware
550  *	signal. The occurrence is latched into the irq controller hardware
551  *	and must be acked in order to be reenabled. After the ack another
552  *	interrupt can happen on the same source even before the first one
553  *	is handled by the associated event handler. If this happens it
554  *	might be necessary to disable (mask) the interrupt depending on the
555  *	controller hardware. This requires to reenable the interrupt inside
556  *	of the loop which handles the interrupts which have arrived while
557  *	the handler was running. If all pending interrupts are handled, the
558  *	loop is left.
559  */
560 void
561 handle_edge_irq(unsigned int irq, struct irq_desc *desc)
562 {
563 	raw_spin_lock(&desc->lock);
564 
565 	desc->istate &= ~(IRQS_REPLAY | IRQS_WAITING);
566 
567 	if (!irq_may_run(desc)) {
568 		desc->istate |= IRQS_PENDING;
569 		mask_ack_irq(desc);
570 		goto out_unlock;
571 	}
572 
573 	/*
574 	 * If its disabled or no action available then mask it and get
575 	 * out of here.
576 	 */
577 	if (irqd_irq_disabled(&desc->irq_data) || !desc->action) {
578 		desc->istate |= IRQS_PENDING;
579 		mask_ack_irq(desc);
580 		goto out_unlock;
581 	}
582 
583 	kstat_incr_irqs_this_cpu(irq, desc);
584 
585 	/* Start handling the irq */
586 	desc->irq_data.chip->irq_ack(&desc->irq_data);
587 
588 	do {
589 		if (unlikely(!desc->action)) {
590 			mask_irq(desc);
591 			goto out_unlock;
592 		}
593 
594 		/*
595 		 * When another irq arrived while we were handling
596 		 * one, we could have masked the irq.
597 		 * Renable it, if it was not disabled in meantime.
598 		 */
599 		if (unlikely(desc->istate & IRQS_PENDING)) {
600 			if (!irqd_irq_disabled(&desc->irq_data) &&
601 			    irqd_irq_masked(&desc->irq_data))
602 				unmask_irq(desc);
603 		}
604 
605 		handle_irq_event(desc);
606 
607 	} while ((desc->istate & IRQS_PENDING) &&
608 		 !irqd_irq_disabled(&desc->irq_data));
609 
610 out_unlock:
611 	raw_spin_unlock(&desc->lock);
612 }
613 EXPORT_SYMBOL(handle_edge_irq);
614 
615 #ifdef CONFIG_IRQ_EDGE_EOI_HANDLER
616 /**
617  *	handle_edge_eoi_irq - edge eoi type IRQ handler
618  *	@irq:	the interrupt number
619  *	@desc:	the interrupt description structure for this irq
620  *
621  * Similar as the above handle_edge_irq, but using eoi and w/o the
622  * mask/unmask logic.
623  */
624 void handle_edge_eoi_irq(unsigned int irq, struct irq_desc *desc)
625 {
626 	struct irq_chip *chip = irq_desc_get_chip(desc);
627 
628 	raw_spin_lock(&desc->lock);
629 
630 	desc->istate &= ~(IRQS_REPLAY | IRQS_WAITING);
631 
632 	if (!irq_may_run(desc)) {
633 		desc->istate |= IRQS_PENDING;
634 		goto out_eoi;
635 	}
636 
637 	/*
638 	 * If its disabled or no action available then mask it and get
639 	 * out of here.
640 	 */
641 	if (irqd_irq_disabled(&desc->irq_data) || !desc->action) {
642 		desc->istate |= IRQS_PENDING;
643 		goto out_eoi;
644 	}
645 
646 	kstat_incr_irqs_this_cpu(irq, desc);
647 
648 	do {
649 		if (unlikely(!desc->action))
650 			goto out_eoi;
651 
652 		handle_irq_event(desc);
653 
654 	} while ((desc->istate & IRQS_PENDING) &&
655 		 !irqd_irq_disabled(&desc->irq_data));
656 
657 out_eoi:
658 	chip->irq_eoi(&desc->irq_data);
659 	raw_spin_unlock(&desc->lock);
660 }
661 #endif
662 
663 /**
664  *	handle_percpu_irq - Per CPU local irq handler
665  *	@irq:	the interrupt number
666  *	@desc:	the interrupt description structure for this irq
667  *
668  *	Per CPU interrupts on SMP machines without locking requirements
669  */
670 void
671 handle_percpu_irq(unsigned int irq, struct irq_desc *desc)
672 {
673 	struct irq_chip *chip = irq_desc_get_chip(desc);
674 
675 	kstat_incr_irqs_this_cpu(irq, desc);
676 
677 	if (chip->irq_ack)
678 		chip->irq_ack(&desc->irq_data);
679 
680 	handle_irq_event_percpu(desc, desc->action);
681 
682 	if (chip->irq_eoi)
683 		chip->irq_eoi(&desc->irq_data);
684 }
685 
686 /**
687  * handle_percpu_devid_irq - Per CPU local irq handler with per cpu dev ids
688  * @irq:	the interrupt number
689  * @desc:	the interrupt description structure for this irq
690  *
691  * Per CPU interrupts on SMP machines without locking requirements. Same as
692  * handle_percpu_irq() above but with the following extras:
693  *
694  * action->percpu_dev_id is a pointer to percpu variables which
695  * contain the real device id for the cpu on which this handler is
696  * called
697  */
698 void handle_percpu_devid_irq(unsigned int irq, struct irq_desc *desc)
699 {
700 	struct irq_chip *chip = irq_desc_get_chip(desc);
701 	struct irqaction *action = desc->action;
702 	void *dev_id = raw_cpu_ptr(action->percpu_dev_id);
703 	irqreturn_t res;
704 
705 	kstat_incr_irqs_this_cpu(irq, desc);
706 
707 	if (chip->irq_ack)
708 		chip->irq_ack(&desc->irq_data);
709 
710 	trace_irq_handler_entry(irq, action);
711 	res = action->handler(irq, dev_id);
712 	trace_irq_handler_exit(irq, action, res);
713 
714 	if (chip->irq_eoi)
715 		chip->irq_eoi(&desc->irq_data);
716 }
717 
718 void
719 __irq_set_handler(unsigned int irq, irq_flow_handler_t handle, int is_chained,
720 		  const char *name)
721 {
722 	unsigned long flags;
723 	struct irq_desc *desc = irq_get_desc_buslock(irq, &flags, 0);
724 
725 	if (!desc)
726 		return;
727 
728 	if (!handle) {
729 		handle = handle_bad_irq;
730 	} else {
731 		if (WARN_ON(desc->irq_data.chip == &no_irq_chip))
732 			goto out;
733 	}
734 
735 	/* Uninstall? */
736 	if (handle == handle_bad_irq) {
737 		if (desc->irq_data.chip != &no_irq_chip)
738 			mask_ack_irq(desc);
739 		irq_state_set_disabled(desc);
740 		desc->depth = 1;
741 	}
742 	desc->handle_irq = handle;
743 	desc->name = name;
744 
745 	if (handle != handle_bad_irq && is_chained) {
746 		irq_settings_set_noprobe(desc);
747 		irq_settings_set_norequest(desc);
748 		irq_settings_set_nothread(desc);
749 		irq_startup(desc, true);
750 	}
751 out:
752 	irq_put_desc_busunlock(desc, flags);
753 }
754 EXPORT_SYMBOL_GPL(__irq_set_handler);
755 
756 void
757 irq_set_chip_and_handler_name(unsigned int irq, struct irq_chip *chip,
758 			      irq_flow_handler_t handle, const char *name)
759 {
760 	irq_set_chip(irq, chip);
761 	__irq_set_handler(irq, handle, 0, name);
762 }
763 EXPORT_SYMBOL_GPL(irq_set_chip_and_handler_name);
764 
765 void irq_modify_status(unsigned int irq, unsigned long clr, unsigned long set)
766 {
767 	unsigned long flags;
768 	struct irq_desc *desc = irq_get_desc_lock(irq, &flags, 0);
769 
770 	if (!desc)
771 		return;
772 	irq_settings_clr_and_set(desc, clr, set);
773 
774 	irqd_clear(&desc->irq_data, IRQD_NO_BALANCING | IRQD_PER_CPU |
775 		   IRQD_TRIGGER_MASK | IRQD_LEVEL | IRQD_MOVE_PCNTXT);
776 	if (irq_settings_has_no_balance_set(desc))
777 		irqd_set(&desc->irq_data, IRQD_NO_BALANCING);
778 	if (irq_settings_is_per_cpu(desc))
779 		irqd_set(&desc->irq_data, IRQD_PER_CPU);
780 	if (irq_settings_can_move_pcntxt(desc))
781 		irqd_set(&desc->irq_data, IRQD_MOVE_PCNTXT);
782 	if (irq_settings_is_level(desc))
783 		irqd_set(&desc->irq_data, IRQD_LEVEL);
784 
785 	irqd_set(&desc->irq_data, irq_settings_get_trigger_mask(desc));
786 
787 	irq_put_desc_unlock(desc, flags);
788 }
789 EXPORT_SYMBOL_GPL(irq_modify_status);
790 
791 /**
792  *	irq_cpu_online - Invoke all irq_cpu_online functions.
793  *
794  *	Iterate through all irqs and invoke the chip.irq_cpu_online()
795  *	for each.
796  */
797 void irq_cpu_online(void)
798 {
799 	struct irq_desc *desc;
800 	struct irq_chip *chip;
801 	unsigned long flags;
802 	unsigned int irq;
803 
804 	for_each_active_irq(irq) {
805 		desc = irq_to_desc(irq);
806 		if (!desc)
807 			continue;
808 
809 		raw_spin_lock_irqsave(&desc->lock, flags);
810 
811 		chip = irq_data_get_irq_chip(&desc->irq_data);
812 		if (chip && chip->irq_cpu_online &&
813 		    (!(chip->flags & IRQCHIP_ONOFFLINE_ENABLED) ||
814 		     !irqd_irq_disabled(&desc->irq_data)))
815 			chip->irq_cpu_online(&desc->irq_data);
816 
817 		raw_spin_unlock_irqrestore(&desc->lock, flags);
818 	}
819 }
820 
821 /**
822  *	irq_cpu_offline - Invoke all irq_cpu_offline functions.
823  *
824  *	Iterate through all irqs and invoke the chip.irq_cpu_offline()
825  *	for each.
826  */
827 void irq_cpu_offline(void)
828 {
829 	struct irq_desc *desc;
830 	struct irq_chip *chip;
831 	unsigned long flags;
832 	unsigned int irq;
833 
834 	for_each_active_irq(irq) {
835 		desc = irq_to_desc(irq);
836 		if (!desc)
837 			continue;
838 
839 		raw_spin_lock_irqsave(&desc->lock, flags);
840 
841 		chip = irq_data_get_irq_chip(&desc->irq_data);
842 		if (chip && chip->irq_cpu_offline &&
843 		    (!(chip->flags & IRQCHIP_ONOFFLINE_ENABLED) ||
844 		     !irqd_irq_disabled(&desc->irq_data)))
845 			chip->irq_cpu_offline(&desc->irq_data);
846 
847 		raw_spin_unlock_irqrestore(&desc->lock, flags);
848 	}
849 }
850