xref: /openbmc/linux/kernel/irq/chip.c (revision e868d61272caa648214046a096e5a6bfc068dc8c)
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 "internals.h"
20 
21 /**
22  *	dynamic_irq_init - initialize a dynamically allocated irq
23  *	@irq:	irq number to initialize
24  */
25 void dynamic_irq_init(unsigned int irq)
26 {
27 	struct irq_desc *desc;
28 	unsigned long flags;
29 
30 	if (irq >= NR_IRQS) {
31 		printk(KERN_ERR "Trying to initialize invalid IRQ%d\n", irq);
32 		WARN_ON(1);
33 		return;
34 	}
35 
36 	/* Ensure we don't have left over values from a previous use of this irq */
37 	desc = irq_desc + irq;
38 	spin_lock_irqsave(&desc->lock, flags);
39 	desc->status = IRQ_DISABLED;
40 	desc->chip = &no_irq_chip;
41 	desc->handle_irq = handle_bad_irq;
42 	desc->depth = 1;
43 	desc->msi_desc = NULL;
44 	desc->handler_data = NULL;
45 	desc->chip_data = NULL;
46 	desc->action = NULL;
47 	desc->irq_count = 0;
48 	desc->irqs_unhandled = 0;
49 #ifdef CONFIG_SMP
50 	desc->affinity = CPU_MASK_ALL;
51 #endif
52 	spin_unlock_irqrestore(&desc->lock, flags);
53 }
54 
55 /**
56  *	dynamic_irq_cleanup - cleanup a dynamically allocated irq
57  *	@irq:	irq number to initialize
58  */
59 void dynamic_irq_cleanup(unsigned int irq)
60 {
61 	struct irq_desc *desc;
62 	unsigned long flags;
63 
64 	if (irq >= NR_IRQS) {
65 		printk(KERN_ERR "Trying to cleanup invalid IRQ%d\n", irq);
66 		WARN_ON(1);
67 		return;
68 	}
69 
70 	desc = irq_desc + irq;
71 	spin_lock_irqsave(&desc->lock, flags);
72 	if (desc->action) {
73 		spin_unlock_irqrestore(&desc->lock, flags);
74 		printk(KERN_ERR "Destroying IRQ%d without calling free_irq\n",
75 			irq);
76 		WARN_ON(1);
77 		return;
78 	}
79 	desc->msi_desc = NULL;
80 	desc->handler_data = NULL;
81 	desc->chip_data = NULL;
82 	desc->handle_irq = handle_bad_irq;
83 	desc->chip = &no_irq_chip;
84 	spin_unlock_irqrestore(&desc->lock, flags);
85 }
86 
87 
88 /**
89  *	set_irq_chip - set the irq chip for an irq
90  *	@irq:	irq number
91  *	@chip:	pointer to irq chip description structure
92  */
93 int set_irq_chip(unsigned int irq, struct irq_chip *chip)
94 {
95 	struct irq_desc *desc;
96 	unsigned long flags;
97 
98 	if (irq >= NR_IRQS) {
99 		printk(KERN_ERR "Trying to install chip for IRQ%d\n", irq);
100 		WARN_ON(1);
101 		return -EINVAL;
102 	}
103 
104 	if (!chip)
105 		chip = &no_irq_chip;
106 
107 	desc = irq_desc + irq;
108 	spin_lock_irqsave(&desc->lock, flags);
109 	irq_chip_set_defaults(chip);
110 	desc->chip = chip;
111 	spin_unlock_irqrestore(&desc->lock, flags);
112 
113 	return 0;
114 }
115 EXPORT_SYMBOL(set_irq_chip);
116 
117 /**
118  *	set_irq_type - set the irq type for an irq
119  *	@irq:	irq number
120  *	@type:	interrupt type - see include/linux/interrupt.h
121  */
122 int set_irq_type(unsigned int irq, unsigned int type)
123 {
124 	struct irq_desc *desc;
125 	unsigned long flags;
126 	int ret = -ENXIO;
127 
128 	if (irq >= NR_IRQS) {
129 		printk(KERN_ERR "Trying to set irq type for IRQ%d\n", irq);
130 		return -ENODEV;
131 	}
132 
133 	desc = irq_desc + irq;
134 	if (desc->chip->set_type) {
135 		spin_lock_irqsave(&desc->lock, flags);
136 		ret = desc->chip->set_type(irq, type);
137 		spin_unlock_irqrestore(&desc->lock, flags);
138 	}
139 	return ret;
140 }
141 EXPORT_SYMBOL(set_irq_type);
142 
143 /**
144  *	set_irq_data - set irq type data for an irq
145  *	@irq:	Interrupt number
146  *	@data:	Pointer to interrupt specific data
147  *
148  *	Set the hardware irq controller data for an irq
149  */
150 int set_irq_data(unsigned int irq, void *data)
151 {
152 	struct irq_desc *desc;
153 	unsigned long flags;
154 
155 	if (irq >= NR_IRQS) {
156 		printk(KERN_ERR
157 		       "Trying to install controller data for IRQ%d\n", irq);
158 		return -EINVAL;
159 	}
160 
161 	desc = irq_desc + irq;
162 	spin_lock_irqsave(&desc->lock, flags);
163 	desc->handler_data = data;
164 	spin_unlock_irqrestore(&desc->lock, flags);
165 	return 0;
166 }
167 EXPORT_SYMBOL(set_irq_data);
168 
169 /**
170  *	set_irq_data - set irq type data for an irq
171  *	@irq:	Interrupt number
172  *	@entry:	Pointer to MSI descriptor data
173  *
174  *	Set the hardware irq controller data for an irq
175  */
176 int set_irq_msi(unsigned int irq, struct msi_desc *entry)
177 {
178 	struct irq_desc *desc;
179 	unsigned long flags;
180 
181 	if (irq >= NR_IRQS) {
182 		printk(KERN_ERR
183 		       "Trying to install msi data for IRQ%d\n", irq);
184 		return -EINVAL;
185 	}
186 	desc = irq_desc + irq;
187 	spin_lock_irqsave(&desc->lock, flags);
188 	desc->msi_desc = entry;
189 	if (entry)
190 		entry->irq = irq;
191 	spin_unlock_irqrestore(&desc->lock, flags);
192 	return 0;
193 }
194 
195 /**
196  *	set_irq_chip_data - set irq chip data for an irq
197  *	@irq:	Interrupt number
198  *	@data:	Pointer to chip specific data
199  *
200  *	Set the hardware irq chip data for an irq
201  */
202 int set_irq_chip_data(unsigned int irq, void *data)
203 {
204 	struct irq_desc *desc = irq_desc + irq;
205 	unsigned long flags;
206 
207 	if (irq >= NR_IRQS || !desc->chip) {
208 		printk(KERN_ERR "BUG: bad set_irq_chip_data(IRQ#%d)\n", irq);
209 		return -EINVAL;
210 	}
211 
212 	spin_lock_irqsave(&desc->lock, flags);
213 	desc->chip_data = data;
214 	spin_unlock_irqrestore(&desc->lock, flags);
215 
216 	return 0;
217 }
218 EXPORT_SYMBOL(set_irq_chip_data);
219 
220 /*
221  * default enable function
222  */
223 static void default_enable(unsigned int irq)
224 {
225 	struct irq_desc *desc = irq_desc + irq;
226 
227 	desc->chip->unmask(irq);
228 	desc->status &= ~IRQ_MASKED;
229 }
230 
231 /*
232  * default disable function
233  */
234 static void default_disable(unsigned int irq)
235 {
236 }
237 
238 /*
239  * default startup function
240  */
241 static unsigned int default_startup(unsigned int irq)
242 {
243 	irq_desc[irq].chip->enable(irq);
244 
245 	return 0;
246 }
247 
248 /*
249  * Fixup enable/disable function pointers
250  */
251 void irq_chip_set_defaults(struct irq_chip *chip)
252 {
253 	if (!chip->enable)
254 		chip->enable = default_enable;
255 	if (!chip->disable)
256 		chip->disable = default_disable;
257 	if (!chip->startup)
258 		chip->startup = default_startup;
259 	if (!chip->shutdown)
260 		chip->shutdown = chip->disable;
261 	if (!chip->name)
262 		chip->name = chip->typename;
263 	if (!chip->end)
264 		chip->end = dummy_irq_chip.end;
265 }
266 
267 static inline void mask_ack_irq(struct irq_desc *desc, int irq)
268 {
269 	if (desc->chip->mask_ack)
270 		desc->chip->mask_ack(irq);
271 	else {
272 		desc->chip->mask(irq);
273 		desc->chip->ack(irq);
274 	}
275 }
276 
277 /**
278  *	handle_simple_irq - Simple and software-decoded IRQs.
279  *	@irq:	the interrupt number
280  *	@desc:	the interrupt description structure for this irq
281  *
282  *	Simple interrupts are either sent from a demultiplexing interrupt
283  *	handler or come from hardware, where no interrupt hardware control
284  *	is necessary.
285  *
286  *	Note: The caller is expected to handle the ack, clear, mask and
287  *	unmask issues if necessary.
288  */
289 void fastcall
290 handle_simple_irq(unsigned int irq, struct irq_desc *desc)
291 {
292 	struct irqaction *action;
293 	irqreturn_t action_ret;
294 	const unsigned int cpu = smp_processor_id();
295 
296 	spin_lock(&desc->lock);
297 
298 	if (unlikely(desc->status & IRQ_INPROGRESS))
299 		goto out_unlock;
300 	kstat_cpu(cpu).irqs[irq]++;
301 
302 	action = desc->action;
303 	if (unlikely(!action || (desc->status & IRQ_DISABLED))) {
304 		if (desc->chip->mask)
305 			desc->chip->mask(irq);
306 		desc->status &= ~(IRQ_REPLAY | IRQ_WAITING);
307 		desc->status |= IRQ_PENDING;
308 		goto out_unlock;
309 	}
310 
311 	desc->status &= ~(IRQ_REPLAY | IRQ_WAITING | IRQ_PENDING);
312 	desc->status |= IRQ_INPROGRESS;
313 	spin_unlock(&desc->lock);
314 
315 	action_ret = handle_IRQ_event(irq, action);
316 	if (!noirqdebug)
317 		note_interrupt(irq, desc, action_ret);
318 
319 	spin_lock(&desc->lock);
320 	desc->status &= ~IRQ_INPROGRESS;
321 out_unlock:
322 	spin_unlock(&desc->lock);
323 }
324 
325 /**
326  *	handle_level_irq - Level type irq handler
327  *	@irq:	the interrupt number
328  *	@desc:	the interrupt description structure for this irq
329  *
330  *	Level type interrupts are active as long as the hardware line has
331  *	the active level. This may require to mask the interrupt and unmask
332  *	it after the associated handler has acknowledged the device, so the
333  *	interrupt line is back to inactive.
334  */
335 void fastcall
336 handle_level_irq(unsigned int irq, struct irq_desc *desc)
337 {
338 	unsigned int cpu = smp_processor_id();
339 	struct irqaction *action;
340 	irqreturn_t action_ret;
341 
342 	spin_lock(&desc->lock);
343 	mask_ack_irq(desc, irq);
344 
345 	if (unlikely(desc->status & IRQ_INPROGRESS))
346 		goto out_unlock;
347 	desc->status &= ~(IRQ_REPLAY | IRQ_WAITING);
348 	kstat_cpu(cpu).irqs[irq]++;
349 
350 	/*
351 	 * If its disabled or no action available
352 	 * keep it masked and get out of here
353 	 */
354 	action = desc->action;
355 	if (unlikely(!action || (desc->status & IRQ_DISABLED))) {
356 		desc->status |= IRQ_PENDING;
357 		goto out_unlock;
358 	}
359 
360 	desc->status |= IRQ_INPROGRESS;
361 	desc->status &= ~IRQ_PENDING;
362 	spin_unlock(&desc->lock);
363 
364 	action_ret = handle_IRQ_event(irq, action);
365 	if (!noirqdebug)
366 		note_interrupt(irq, desc, action_ret);
367 
368 	spin_lock(&desc->lock);
369 	desc->status &= ~IRQ_INPROGRESS;
370 	if (!(desc->status & IRQ_DISABLED) && desc->chip->unmask)
371 		desc->chip->unmask(irq);
372 out_unlock:
373 	spin_unlock(&desc->lock);
374 }
375 
376 /**
377  *	handle_fasteoi_irq - irq handler for transparent controllers
378  *	@irq:	the interrupt number
379  *	@desc:	the interrupt description structure for this irq
380  *
381  *	Only a single callback will be issued to the chip: an ->eoi()
382  *	call when the interrupt has been serviced. This enables support
383  *	for modern forms of interrupt handlers, which handle the flow
384  *	details in hardware, transparently.
385  */
386 void fastcall
387 handle_fasteoi_irq(unsigned int irq, struct irq_desc *desc)
388 {
389 	unsigned int cpu = smp_processor_id();
390 	struct irqaction *action;
391 	irqreturn_t action_ret;
392 
393 	spin_lock(&desc->lock);
394 
395 	if (unlikely(desc->status & IRQ_INPROGRESS))
396 		goto out;
397 
398 	desc->status &= ~(IRQ_REPLAY | IRQ_WAITING);
399 	kstat_cpu(cpu).irqs[irq]++;
400 
401 	/*
402 	 * If its disabled or no action available
403 	 * then mask it and get out of here:
404 	 */
405 	action = desc->action;
406 	if (unlikely(!action || (desc->status & IRQ_DISABLED))) {
407 		desc->status |= IRQ_PENDING;
408 		if (desc->chip->mask)
409 			desc->chip->mask(irq);
410 		goto out;
411 	}
412 
413 	desc->status |= IRQ_INPROGRESS;
414 	desc->status &= ~IRQ_PENDING;
415 	spin_unlock(&desc->lock);
416 
417 	action_ret = handle_IRQ_event(irq, action);
418 	if (!noirqdebug)
419 		note_interrupt(irq, desc, action_ret);
420 
421 	spin_lock(&desc->lock);
422 	desc->status &= ~IRQ_INPROGRESS;
423 out:
424 	desc->chip->eoi(irq);
425 
426 	spin_unlock(&desc->lock);
427 }
428 
429 /**
430  *	handle_edge_irq - edge type IRQ handler
431  *	@irq:	the interrupt number
432  *	@desc:	the interrupt description structure for this irq
433  *
434  *	Interrupt occures on the falling and/or rising edge of a hardware
435  *	signal. The occurence is latched into the irq controller hardware
436  *	and must be acked in order to be reenabled. After the ack another
437  *	interrupt can happen on the same source even before the first one
438  *	is handled by the assosiacted event handler. If this happens it
439  *	might be necessary to disable (mask) the interrupt depending on the
440  *	controller hardware. This requires to reenable the interrupt inside
441  *	of the loop which handles the interrupts which have arrived while
442  *	the handler was running. If all pending interrupts are handled, the
443  *	loop is left.
444  */
445 void fastcall
446 handle_edge_irq(unsigned int irq, struct irq_desc *desc)
447 {
448 	const unsigned int cpu = smp_processor_id();
449 
450 	spin_lock(&desc->lock);
451 
452 	desc->status &= ~(IRQ_REPLAY | IRQ_WAITING);
453 
454 	/*
455 	 * If we're currently running this IRQ, or its disabled,
456 	 * we shouldn't process the IRQ. Mark it pending, handle
457 	 * the necessary masking and go out
458 	 */
459 	if (unlikely((desc->status & (IRQ_INPROGRESS | IRQ_DISABLED)) ||
460 		    !desc->action)) {
461 		desc->status |= (IRQ_PENDING | IRQ_MASKED);
462 		mask_ack_irq(desc, irq);
463 		goto out_unlock;
464 	}
465 
466 	kstat_cpu(cpu).irqs[irq]++;
467 
468 	/* Start handling the irq */
469 	desc->chip->ack(irq);
470 
471 	/* Mark the IRQ currently in progress.*/
472 	desc->status |= IRQ_INPROGRESS;
473 
474 	do {
475 		struct irqaction *action = desc->action;
476 		irqreturn_t action_ret;
477 
478 		if (unlikely(!action)) {
479 			desc->chip->mask(irq);
480 			goto out_unlock;
481 		}
482 
483 		/*
484 		 * When another irq arrived while we were handling
485 		 * one, we could have masked the irq.
486 		 * Renable it, if it was not disabled in meantime.
487 		 */
488 		if (unlikely((desc->status &
489 			       (IRQ_PENDING | IRQ_MASKED | IRQ_DISABLED)) ==
490 			      (IRQ_PENDING | IRQ_MASKED))) {
491 			desc->chip->unmask(irq);
492 			desc->status &= ~IRQ_MASKED;
493 		}
494 
495 		desc->status &= ~IRQ_PENDING;
496 		spin_unlock(&desc->lock);
497 		action_ret = handle_IRQ_event(irq, action);
498 		if (!noirqdebug)
499 			note_interrupt(irq, desc, action_ret);
500 		spin_lock(&desc->lock);
501 
502 	} while ((desc->status & (IRQ_PENDING | IRQ_DISABLED)) == IRQ_PENDING);
503 
504 	desc->status &= ~IRQ_INPROGRESS;
505 out_unlock:
506 	spin_unlock(&desc->lock);
507 }
508 
509 #ifdef CONFIG_SMP
510 /**
511  *	handle_percpu_IRQ - Per CPU local irq handler
512  *	@irq:	the interrupt number
513  *	@desc:	the interrupt description structure for this irq
514  *
515  *	Per CPU interrupts on SMP machines without locking requirements
516  */
517 void fastcall
518 handle_percpu_irq(unsigned int irq, struct irq_desc *desc)
519 {
520 	irqreturn_t action_ret;
521 
522 	kstat_this_cpu.irqs[irq]++;
523 
524 	if (desc->chip->ack)
525 		desc->chip->ack(irq);
526 
527 	action_ret = handle_IRQ_event(irq, desc->action);
528 	if (!noirqdebug)
529 		note_interrupt(irq, desc, action_ret);
530 
531 	if (desc->chip->eoi)
532 		desc->chip->eoi(irq);
533 }
534 
535 #endif /* CONFIG_SMP */
536 
537 void
538 __set_irq_handler(unsigned int irq, irq_flow_handler_t handle, int is_chained,
539 		  const char *name)
540 {
541 	struct irq_desc *desc;
542 	unsigned long flags;
543 
544 	if (irq >= NR_IRQS) {
545 		printk(KERN_ERR
546 		       "Trying to install type control for IRQ%d\n", irq);
547 		return;
548 	}
549 
550 	desc = irq_desc + irq;
551 
552 	if (!handle)
553 		handle = handle_bad_irq;
554 	else if (desc->chip == &no_irq_chip) {
555 		printk(KERN_WARNING "Trying to install %sinterrupt handler "
556 		       "for IRQ%d\n", is_chained ? "chained " : "", irq);
557 		/*
558 		 * Some ARM implementations install a handler for really dumb
559 		 * interrupt hardware without setting an irq_chip. This worked
560 		 * with the ARM no_irq_chip but the check in setup_irq would
561 		 * prevent us to setup the interrupt at all. Switch it to
562 		 * dummy_irq_chip for easy transition.
563 		 */
564 		desc->chip = &dummy_irq_chip;
565 	}
566 
567 	spin_lock_irqsave(&desc->lock, flags);
568 
569 	/* Uninstall? */
570 	if (handle == handle_bad_irq) {
571 		if (desc->chip != &no_irq_chip)
572 			mask_ack_irq(desc, irq);
573 		desc->status |= IRQ_DISABLED;
574 		desc->depth = 1;
575 	}
576 	desc->handle_irq = handle;
577 	desc->name = name;
578 
579 	if (handle != handle_bad_irq && is_chained) {
580 		desc->status &= ~IRQ_DISABLED;
581 		desc->status |= IRQ_NOREQUEST | IRQ_NOPROBE;
582 		desc->depth = 0;
583 		desc->chip->unmask(irq);
584 	}
585 	spin_unlock_irqrestore(&desc->lock, flags);
586 }
587 
588 void
589 set_irq_chip_and_handler(unsigned int irq, struct irq_chip *chip,
590 			 irq_flow_handler_t handle)
591 {
592 	set_irq_chip(irq, chip);
593 	__set_irq_handler(irq, handle, 0, NULL);
594 }
595 
596 void
597 set_irq_chip_and_handler_name(unsigned int irq, struct irq_chip *chip,
598 			      irq_flow_handler_t handle, const char *name)
599 {
600 	set_irq_chip(irq, chip);
601 	__set_irq_handler(irq, handle, 0, name);
602 }
603