2 * linux/kernel/irq/chip.c
4 * Copyright (C) 1992, 1998-2006 Linus Torvalds, Ingo Molnar
5 * Copyright (C) 2005-2006, Thomas Gleixner, Russell King
7 * This file contains the core interrupt handling code, for irq-chip
10 * Detailed information is available in Documentation/DocBook/genericirq
13 #include <linux/irq.h>
14 #include <linux/module.h>
15 #include <linux/interrupt.h>
16 #include <linux/kernel_stat.h>
18 #include "internals.h"
21 * dynamic_irq_init - initialize a dynamically allocated irq
22 * @irq: irq number to initialize
24 void dynamic_irq_init(unsigned int irq)
26 struct irq_desc *desc;
30 printk(KERN_ERR "Trying to initialize invalid IRQ%d\n", irq);
35 /* Ensure we don't have left over values from a previous use of this irq */
36 desc = irq_desc + irq;
37 spin_lock_irqsave(&desc->lock, flags);
38 desc->status = IRQ_DISABLED;
39 desc->chip = &no_irq_chip;
40 desc->handle_irq = handle_bad_irq;
42 desc->handler_data = NULL;
43 desc->chip_data = NULL;
46 desc->irqs_unhandled = 0;
48 desc->affinity = CPU_MASK_ALL;
50 spin_unlock_irqrestore(&desc->lock, flags);
54 * dynamic_irq_cleanup - cleanup a dynamically allocated irq
55 * @irq: irq number to initialize
57 void dynamic_irq_cleanup(unsigned int irq)
59 struct irq_desc *desc;
63 printk(KERN_ERR "Trying to cleanup invalid IRQ%d\n", irq);
68 desc = irq_desc + irq;
69 spin_lock_irqsave(&desc->lock, flags);
71 spin_unlock_irqrestore(&desc->lock, flags);
72 printk(KERN_ERR "Destroying IRQ%d without calling free_irq\n",
77 desc->handle_irq = handle_bad_irq;
78 desc->chip = &no_irq_chip;
79 spin_unlock_irqrestore(&desc->lock, flags);
84 * set_irq_chip - set the irq chip for an irq
86 * @chip: pointer to irq chip description structure
88 int set_irq_chip(unsigned int irq, struct irq_chip *chip)
90 struct irq_desc *desc;
94 printk(KERN_ERR "Trying to install chip for IRQ%d\n", irq);
102 desc = irq_desc + irq;
103 spin_lock_irqsave(&desc->lock, flags);
104 irq_chip_set_defaults(chip);
106 spin_unlock_irqrestore(&desc->lock, flags);
110 EXPORT_SYMBOL(set_irq_chip);
113 * set_irq_type - set the irq type for an irq
115 * @type: interrupt type - see include/linux/interrupt.h
117 int set_irq_type(unsigned int irq, unsigned int type)
119 struct irq_desc *desc;
123 if (irq >= NR_IRQS) {
124 printk(KERN_ERR "Trying to set irq type for IRQ%d\n", irq);
128 desc = irq_desc + irq;
129 if (desc->chip->set_type) {
130 spin_lock_irqsave(&desc->lock, flags);
131 ret = desc->chip->set_type(irq, type);
132 spin_unlock_irqrestore(&desc->lock, flags);
136 EXPORT_SYMBOL(set_irq_type);
139 * set_irq_data - set irq type data for an irq
140 * @irq: Interrupt number
141 * @data: Pointer to interrupt specific data
143 * Set the hardware irq controller data for an irq
145 int set_irq_data(unsigned int irq, void *data)
147 struct irq_desc *desc;
150 if (irq >= NR_IRQS) {
152 "Trying to install controller data for IRQ%d\n", irq);
156 desc = irq_desc + irq;
157 spin_lock_irqsave(&desc->lock, flags);
158 desc->handler_data = data;
159 spin_unlock_irqrestore(&desc->lock, flags);
162 EXPORT_SYMBOL(set_irq_data);
165 * set_irq_chip_data - set irq chip data for an irq
166 * @irq: Interrupt number
167 * @data: Pointer to chip specific data
169 * Set the hardware irq chip data for an irq
171 int set_irq_chip_data(unsigned int irq, void *data)
173 struct irq_desc *desc = irq_desc + irq;
176 if (irq >= NR_IRQS || !desc->chip) {
177 printk(KERN_ERR "BUG: bad set_irq_chip_data(IRQ#%d)\n", irq);
181 spin_lock_irqsave(&desc->lock, flags);
182 desc->chip_data = data;
183 spin_unlock_irqrestore(&desc->lock, flags);
187 EXPORT_SYMBOL(set_irq_chip_data);
190 * default enable function
192 static void default_enable(unsigned int irq)
194 struct irq_desc *desc = irq_desc + irq;
196 desc->chip->unmask(irq);
197 desc->status &= ~IRQ_MASKED;
201 * default disable function
203 static void default_disable(unsigned int irq)
205 struct irq_desc *desc = irq_desc + irq;
207 if (!(desc->status & IRQ_DELAYED_DISABLE))
208 desc->chip->mask(irq);
212 * default startup function
214 static unsigned int default_startup(unsigned int irq)
216 irq_desc[irq].chip->enable(irq);
222 * Fixup enable/disable function pointers
224 void irq_chip_set_defaults(struct irq_chip *chip)
227 chip->enable = default_enable;
229 chip->disable = default_disable;
231 chip->startup = default_startup;
233 chip->shutdown = chip->disable;
235 chip->name = chip->typename;
238 static inline void mask_ack_irq(struct irq_desc *desc, int irq)
240 if (desc->chip->mask_ack)
241 desc->chip->mask_ack(irq);
243 desc->chip->mask(irq);
244 desc->chip->ack(irq);
249 * handle_simple_irq - Simple and software-decoded IRQs.
250 * @irq: the interrupt number
251 * @desc: the interrupt description structure for this irq
253 * Simple interrupts are either sent from a demultiplexing interrupt
254 * handler or come from hardware, where no interrupt hardware control
257 * Note: The caller is expected to handle the ack, clear, mask and
258 * unmask issues if necessary.
261 handle_simple_irq(unsigned int irq, struct irq_desc *desc)
263 struct irqaction *action;
264 irqreturn_t action_ret;
265 const unsigned int cpu = smp_processor_id();
267 spin_lock(&desc->lock);
269 if (unlikely(desc->status & IRQ_INPROGRESS))
271 desc->status &= ~(IRQ_REPLAY | IRQ_WAITING);
272 kstat_cpu(cpu).irqs[irq]++;
274 action = desc->action;
275 if (unlikely(!action || (desc->status & IRQ_DISABLED)))
278 desc->status |= IRQ_INPROGRESS;
279 spin_unlock(&desc->lock);
281 action_ret = handle_IRQ_event(irq, action);
283 note_interrupt(irq, desc, action_ret);
285 spin_lock(&desc->lock);
286 desc->status &= ~IRQ_INPROGRESS;
288 spin_unlock(&desc->lock);
292 * handle_level_irq - Level type irq handler
293 * @irq: the interrupt number
294 * @desc: the interrupt description structure for this irq
296 * Level type interrupts are active as long as the hardware line has
297 * the active level. This may require to mask the interrupt and unmask
298 * it after the associated handler has acknowledged the device, so the
299 * interrupt line is back to inactive.
302 handle_level_irq(unsigned int irq, struct irq_desc *desc)
304 unsigned int cpu = smp_processor_id();
305 struct irqaction *action;
306 irqreturn_t action_ret;
308 spin_lock(&desc->lock);
309 mask_ack_irq(desc, irq);
311 if (unlikely(desc->status & IRQ_INPROGRESS))
313 desc->status &= ~(IRQ_REPLAY | IRQ_WAITING);
314 kstat_cpu(cpu).irqs[irq]++;
317 * If its disabled or no action available
318 * keep it masked and get out of here
320 action = desc->action;
321 if (unlikely(!action || (desc->status & IRQ_DISABLED))) {
322 desc->status |= IRQ_PENDING;
326 desc->status |= IRQ_INPROGRESS;
327 desc->status &= ~IRQ_PENDING;
328 spin_unlock(&desc->lock);
330 action_ret = handle_IRQ_event(irq, action);
332 note_interrupt(irq, desc, action_ret);
334 spin_lock(&desc->lock);
335 desc->status &= ~IRQ_INPROGRESS;
336 if (!(desc->status & IRQ_DISABLED) && desc->chip->unmask)
337 desc->chip->unmask(irq);
339 spin_unlock(&desc->lock);
343 * handle_fasteoi_irq - irq handler for transparent controllers
344 * @irq: the interrupt number
345 * @desc: the interrupt description structure for this irq
347 * Only a single callback will be issued to the chip: an ->eoi()
348 * call when the interrupt has been serviced. This enables support
349 * for modern forms of interrupt handlers, which handle the flow
350 * details in hardware, transparently.
353 handle_fasteoi_irq(unsigned int irq, struct irq_desc *desc)
355 unsigned int cpu = smp_processor_id();
356 struct irqaction *action;
357 irqreturn_t action_ret;
359 spin_lock(&desc->lock);
361 if (unlikely(desc->status & IRQ_INPROGRESS))
364 desc->status &= ~(IRQ_REPLAY | IRQ_WAITING);
365 kstat_cpu(cpu).irqs[irq]++;
368 * If its disabled or no action available
369 * keep it masked and get out of here
371 action = desc->action;
372 if (unlikely(!action || (desc->status & IRQ_DISABLED))) {
373 desc->status |= IRQ_PENDING;
377 desc->status |= IRQ_INPROGRESS;
378 desc->status &= ~IRQ_PENDING;
379 spin_unlock(&desc->lock);
381 action_ret = handle_IRQ_event(irq, action);
383 note_interrupt(irq, desc, action_ret);
385 spin_lock(&desc->lock);
386 desc->status &= ~IRQ_INPROGRESS;
388 desc->chip->eoi(irq);
390 spin_unlock(&desc->lock);
394 * handle_edge_irq - edge type IRQ handler
395 * @irq: the interrupt number
396 * @desc: the interrupt description structure for this irq
398 * Interrupt occures on the falling and/or rising edge of a hardware
399 * signal. The occurence is latched into the irq controller hardware
400 * and must be acked in order to be reenabled. After the ack another
401 * interrupt can happen on the same source even before the first one
402 * is handled by the assosiacted event handler. If this happens it
403 * might be necessary to disable (mask) the interrupt depending on the
404 * controller hardware. This requires to reenable the interrupt inside
405 * of the loop which handles the interrupts which have arrived while
406 * the handler was running. If all pending interrupts are handled, the
410 handle_edge_irq(unsigned int irq, struct irq_desc *desc)
412 const unsigned int cpu = smp_processor_id();
414 spin_lock(&desc->lock);
416 desc->status &= ~(IRQ_REPLAY | IRQ_WAITING);
419 * If we're currently running this IRQ, or its disabled,
420 * we shouldn't process the IRQ. Mark it pending, handle
421 * the necessary masking and go out
423 if (unlikely((desc->status & (IRQ_INPROGRESS | IRQ_DISABLED)) ||
425 desc->status |= (IRQ_PENDING | IRQ_MASKED);
426 mask_ack_irq(desc, irq);
430 kstat_cpu(cpu).irqs[irq]++;
432 /* Start handling the irq */
433 desc->chip->ack(irq);
435 /* Mark the IRQ currently in progress.*/
436 desc->status |= IRQ_INPROGRESS;
439 struct irqaction *action = desc->action;
440 irqreturn_t action_ret;
442 if (unlikely(!action)) {
443 desc->chip->mask(irq);
448 * When another irq arrived while we were handling
449 * one, we could have masked the irq.
450 * Renable it, if it was not disabled in meantime.
452 if (unlikely((desc->status &
453 (IRQ_PENDING | IRQ_MASKED | IRQ_DISABLED)) ==
454 (IRQ_PENDING | IRQ_MASKED))) {
455 desc->chip->unmask(irq);
456 desc->status &= ~IRQ_MASKED;
459 desc->status &= ~IRQ_PENDING;
460 spin_unlock(&desc->lock);
461 action_ret = handle_IRQ_event(irq, action);
463 note_interrupt(irq, desc, action_ret);
464 spin_lock(&desc->lock);
466 } while ((desc->status & (IRQ_PENDING | IRQ_DISABLED)) == IRQ_PENDING);
468 desc->status &= ~IRQ_INPROGRESS;
470 spin_unlock(&desc->lock);
475 * handle_percpu_IRQ - Per CPU local irq handler
476 * @irq: the interrupt number
477 * @desc: the interrupt description structure for this irq
479 * Per CPU interrupts on SMP machines without locking requirements
482 handle_percpu_irq(unsigned int irq, struct irq_desc *desc)
484 irqreturn_t action_ret;
486 kstat_this_cpu.irqs[irq]++;
489 desc->chip->ack(irq);
491 action_ret = handle_IRQ_event(irq, desc->action);
493 note_interrupt(irq, desc, action_ret);
496 desc->chip->eoi(irq);
499 #endif /* CONFIG_SMP */
502 __set_irq_handler(unsigned int irq, irq_flow_handler_t handle, int is_chained,
505 struct irq_desc *desc;
508 if (irq >= NR_IRQS) {
510 "Trying to install type control for IRQ%d\n", irq);
514 desc = irq_desc + irq;
517 handle = handle_bad_irq;
519 if (desc->chip == &no_irq_chip) {
520 printk(KERN_WARNING "Trying to install %sinterrupt handler "
521 "for IRQ%d\n", is_chained ? "chained " : " ", irq);
523 * Some ARM implementations install a handler for really dumb
524 * interrupt hardware without setting an irq_chip. This worked
525 * with the ARM no_irq_chip but the check in setup_irq would
526 * prevent us to setup the interrupt at all. Switch it to
527 * dummy_irq_chip for easy transition.
529 desc->chip = &dummy_irq_chip;
532 spin_lock_irqsave(&desc->lock, flags);
535 if (handle == handle_bad_irq) {
536 if (desc->chip != &no_irq_chip) {
537 desc->chip->mask(irq);
538 desc->chip->ack(irq);
540 desc->status |= IRQ_DISABLED;
543 desc->handle_irq = handle;
546 if (handle != handle_bad_irq && is_chained) {
547 desc->status &= ~IRQ_DISABLED;
548 desc->status |= IRQ_NOREQUEST | IRQ_NOPROBE;
550 desc->chip->unmask(irq);
552 spin_unlock_irqrestore(&desc->lock, flags);
556 set_irq_chip_and_handler(unsigned int irq, struct irq_chip *chip,
557 irq_flow_handler_t handle)
559 set_irq_chip(irq, chip);
560 __set_irq_handler(irq, handle, 0, NULL);
564 set_irq_chip_and_handler_name(unsigned int irq, struct irq_chip *chip,
565 irq_flow_handler_t handle, const char *name)
567 set_irq_chip(irq, chip);
568 __set_irq_handler(irq, handle, 0, name);