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-rw-r--r--arch/arm/kernel/irq.c1038
1 files changed, 1038 insertions, 0 deletions
diff --git a/arch/arm/kernel/irq.c b/arch/arm/kernel/irq.c
new file mode 100644
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1/*
2 * linux/arch/arm/kernel/irq.c
3 *
4 * Copyright (C) 1992 Linus Torvalds
5 * Modifications for ARM processor Copyright (C) 1995-2000 Russell King.
6 *
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License version 2 as
9 * published by the Free Software Foundation.
10 *
11 * This file contains the code used by various IRQ handling routines:
12 * asking for different IRQ's should be done through these routines
13 * instead of just grabbing them. Thus setups with different IRQ numbers
14 * shouldn't result in any weird surprises, and installing new handlers
15 * should be easier.
16 *
17 * IRQ's are in fact implemented a bit like signal handlers for the kernel.
18 * Naturally it's not a 1:1 relation, but there are similarities.
19 */
20#include <linux/config.h>
21#include <linux/kernel_stat.h>
22#include <linux/module.h>
23#include <linux/signal.h>
24#include <linux/ioport.h>
25#include <linux/interrupt.h>
26#include <linux/ptrace.h>
27#include <linux/slab.h>
28#include <linux/random.h>
29#include <linux/smp.h>
30#include <linux/init.h>
31#include <linux/seq_file.h>
32#include <linux/errno.h>
33#include <linux/list.h>
34#include <linux/kallsyms.h>
35#include <linux/proc_fs.h>
36
37#include <asm/irq.h>
38#include <asm/system.h>
39#include <asm/mach/irq.h>
40
41/*
42 * Maximum IRQ count. Currently, this is arbitary. However, it should
43 * not be set too low to prevent false triggering. Conversely, if it
44 * is set too high, then you could miss a stuck IRQ.
45 *
46 * Maybe we ought to set a timer and re-enable the IRQ at a later time?
47 */
48#define MAX_IRQ_CNT 100000
49
50static int noirqdebug;
51static volatile unsigned long irq_err_count;
52static DEFINE_SPINLOCK(irq_controller_lock);
53static LIST_HEAD(irq_pending);
54
55struct irqdesc irq_desc[NR_IRQS];
56void (*init_arch_irq)(void) __initdata = NULL;
57
58/*
59 * No architecture-specific irq_finish function defined in arm/arch/irqs.h.
60 */
61#ifndef irq_finish
62#define irq_finish(irq) do { } while (0)
63#endif
64
65/*
66 * Dummy mask/unmask handler
67 */
68void dummy_mask_unmask_irq(unsigned int irq)
69{
70}
71
72irqreturn_t no_action(int irq, void *dev_id, struct pt_regs *regs)
73{
74 return IRQ_NONE;
75}
76
77void do_bad_IRQ(unsigned int irq, struct irqdesc *desc, struct pt_regs *regs)
78{
79 irq_err_count += 1;
80 printk(KERN_ERR "IRQ: spurious interrupt %d\n", irq);
81}
82
83static struct irqchip bad_chip = {
84 .ack = dummy_mask_unmask_irq,
85 .mask = dummy_mask_unmask_irq,
86 .unmask = dummy_mask_unmask_irq,
87};
88
89static struct irqdesc bad_irq_desc = {
90 .chip = &bad_chip,
91 .handle = do_bad_IRQ,
92 .pend = LIST_HEAD_INIT(bad_irq_desc.pend),
93 .disable_depth = 1,
94};
95
96#ifdef CONFIG_SMP
97void synchronize_irq(unsigned int irq)
98{
99 struct irqdesc *desc = irq_desc + irq;
100
101 while (desc->running)
102 barrier();
103}
104EXPORT_SYMBOL(synchronize_irq);
105
106#define smp_set_running(desc) do { desc->running = 1; } while (0)
107#define smp_clear_running(desc) do { desc->running = 0; } while (0)
108#else
109#define smp_set_running(desc) do { } while (0)
110#define smp_clear_running(desc) do { } while (0)
111#endif
112
113/**
114 * disable_irq_nosync - disable an irq without waiting
115 * @irq: Interrupt to disable
116 *
117 * Disable the selected interrupt line. Enables and disables
118 * are nested. We do this lazily.
119 *
120 * This function may be called from IRQ context.
121 */
122void disable_irq_nosync(unsigned int irq)
123{
124 struct irqdesc *desc = irq_desc + irq;
125 unsigned long flags;
126
127 spin_lock_irqsave(&irq_controller_lock, flags);
128 desc->disable_depth++;
129 list_del_init(&desc->pend);
130 spin_unlock_irqrestore(&irq_controller_lock, flags);
131}
132EXPORT_SYMBOL(disable_irq_nosync);
133
134/**
135 * disable_irq - disable an irq and wait for completion
136 * @irq: Interrupt to disable
137 *
138 * Disable the selected interrupt line. Enables and disables
139 * are nested. This functions waits for any pending IRQ
140 * handlers for this interrupt to complete before returning.
141 * If you use this function while holding a resource the IRQ
142 * handler may need you will deadlock.
143 *
144 * This function may be called - with care - from IRQ context.
145 */
146void disable_irq(unsigned int irq)
147{
148 struct irqdesc *desc = irq_desc + irq;
149
150 disable_irq_nosync(irq);
151 if (desc->action)
152 synchronize_irq(irq);
153}
154EXPORT_SYMBOL(disable_irq);
155
156/**
157 * enable_irq - enable interrupt handling on an irq
158 * @irq: Interrupt to enable
159 *
160 * Re-enables the processing of interrupts on this IRQ line.
161 * Note that this may call the interrupt handler, so you may
162 * get unexpected results if you hold IRQs disabled.
163 *
164 * This function may be called from IRQ context.
165 */
166void enable_irq(unsigned int irq)
167{
168 struct irqdesc *desc = irq_desc + irq;
169 unsigned long flags;
170
171 spin_lock_irqsave(&irq_controller_lock, flags);
172 if (unlikely(!desc->disable_depth)) {
173 printk("enable_irq(%u) unbalanced from %p\n", irq,
174 __builtin_return_address(0));
175 } else if (!--desc->disable_depth) {
176 desc->probing = 0;
177 desc->chip->unmask(irq);
178
179 /*
180 * If the interrupt is waiting to be processed,
181 * try to re-run it. We can't directly run it
182 * from here since the caller might be in an
183 * interrupt-protected region.
184 */
185 if (desc->pending && list_empty(&desc->pend)) {
186 desc->pending = 0;
187 if (!desc->chip->retrigger ||
188 desc->chip->retrigger(irq))
189 list_add(&desc->pend, &irq_pending);
190 }
191 }
192 spin_unlock_irqrestore(&irq_controller_lock, flags);
193}
194EXPORT_SYMBOL(enable_irq);
195
196/*
197 * Enable wake on selected irq
198 */
199void enable_irq_wake(unsigned int irq)
200{
201 struct irqdesc *desc = irq_desc + irq;
202 unsigned long flags;
203
204 spin_lock_irqsave(&irq_controller_lock, flags);
205 if (desc->chip->wake)
206 desc->chip->wake(irq, 1);
207 spin_unlock_irqrestore(&irq_controller_lock, flags);
208}
209EXPORT_SYMBOL(enable_irq_wake);
210
211void disable_irq_wake(unsigned int irq)
212{
213 struct irqdesc *desc = irq_desc + irq;
214 unsigned long flags;
215
216 spin_lock_irqsave(&irq_controller_lock, flags);
217 if (desc->chip->wake)
218 desc->chip->wake(irq, 0);
219 spin_unlock_irqrestore(&irq_controller_lock, flags);
220}
221EXPORT_SYMBOL(disable_irq_wake);
222
223int show_interrupts(struct seq_file *p, void *v)
224{
225 int i = *(loff_t *) v, cpu;
226 struct irqaction * action;
227 unsigned long flags;
228
229 if (i == 0) {
230 char cpuname[12];
231
232 seq_printf(p, " ");
233 for_each_present_cpu(cpu) {
234 sprintf(cpuname, "CPU%d", cpu);
235 seq_printf(p, " %10s", cpuname);
236 }
237 seq_putc(p, '\n');
238 }
239
240 if (i < NR_IRQS) {
241 spin_lock_irqsave(&irq_controller_lock, flags);
242 action = irq_desc[i].action;
243 if (!action)
244 goto unlock;
245
246 seq_printf(p, "%3d: ", i);
247 for_each_present_cpu(cpu)
248 seq_printf(p, "%10u ", kstat_cpu(cpu).irqs[i]);
249 seq_printf(p, " %s", action->name);
250 for (action = action->next; action; action = action->next)
251 seq_printf(p, ", %s", action->name);
252
253 seq_putc(p, '\n');
254unlock:
255 spin_unlock_irqrestore(&irq_controller_lock, flags);
256 } else if (i == NR_IRQS) {
257#ifdef CONFIG_ARCH_ACORN
258 show_fiq_list(p, v);
259#endif
260#ifdef CONFIG_SMP
261 show_ipi_list(p);
262#endif
263 seq_printf(p, "Err: %10lu\n", irq_err_count);
264 }
265 return 0;
266}
267
268/*
269 * IRQ lock detection.
270 *
271 * Hopefully, this should get us out of a few locked situations.
272 * However, it may take a while for this to happen, since we need
273 * a large number if IRQs to appear in the same jiffie with the
274 * same instruction pointer (or within 2 instructions).
275 */
276static int check_irq_lock(struct irqdesc *desc, int irq, struct pt_regs *regs)
277{
278 unsigned long instr_ptr = instruction_pointer(regs);
279
280 if (desc->lck_jif == jiffies &&
281 desc->lck_pc >= instr_ptr && desc->lck_pc < instr_ptr + 8) {
282 desc->lck_cnt += 1;
283
284 if (desc->lck_cnt > MAX_IRQ_CNT) {
285 printk(KERN_ERR "IRQ LOCK: IRQ%d is locking the system, disabled\n", irq);
286 return 1;
287 }
288 } else {
289 desc->lck_cnt = 0;
290 desc->lck_pc = instruction_pointer(regs);
291 desc->lck_jif = jiffies;
292 }
293 return 0;
294}
295
296static void
297report_bad_irq(unsigned int irq, struct pt_regs *regs, struct irqdesc *desc, int ret)
298{
299 static int count = 100;
300 struct irqaction *action;
301
302 if (!count || noirqdebug)
303 return;
304
305 count--;
306
307 if (ret != IRQ_HANDLED && ret != IRQ_NONE) {
308 printk("irq%u: bogus retval mask %x\n", irq, ret);
309 } else {
310 printk("irq%u: nobody cared\n", irq);
311 }
312 show_regs(regs);
313 dump_stack();
314 printk(KERN_ERR "handlers:");
315 action = desc->action;
316 do {
317 printk("\n" KERN_ERR "[<%p>]", action->handler);
318 print_symbol(" (%s)", (unsigned long)action->handler);
319 action = action->next;
320 } while (action);
321 printk("\n");
322}
323
324static int
325__do_irq(unsigned int irq, struct irqaction *action, struct pt_regs *regs)
326{
327 unsigned int status;
328 int ret, retval = 0;
329
330 spin_unlock(&irq_controller_lock);
331
332 if (!(action->flags & SA_INTERRUPT))
333 local_irq_enable();
334
335 status = 0;
336 do {
337 ret = action->handler(irq, action->dev_id, regs);
338 if (ret == IRQ_HANDLED)
339 status |= action->flags;
340 retval |= ret;
341 action = action->next;
342 } while (action);
343
344 if (status & SA_SAMPLE_RANDOM)
345 add_interrupt_randomness(irq);
346
347 spin_lock_irq(&irq_controller_lock);
348
349 return retval;
350}
351
352/*
353 * This is for software-decoded IRQs. The caller is expected to
354 * handle the ack, clear, mask and unmask issues.
355 */
356void
357do_simple_IRQ(unsigned int irq, struct irqdesc *desc, struct pt_regs *regs)
358{
359 struct irqaction *action;
360 const unsigned int cpu = smp_processor_id();
361
362 desc->triggered = 1;
363
364 kstat_cpu(cpu).irqs[irq]++;
365
366 smp_set_running(desc);
367
368 action = desc->action;
369 if (action) {
370 int ret = __do_irq(irq, action, regs);
371 if (ret != IRQ_HANDLED)
372 report_bad_irq(irq, regs, desc, ret);
373 }
374
375 smp_clear_running(desc);
376}
377
378/*
379 * Most edge-triggered IRQ implementations seem to take a broken
380 * approach to this. Hence the complexity.
381 */
382void
383do_edge_IRQ(unsigned int irq, struct irqdesc *desc, struct pt_regs *regs)
384{
385 const unsigned int cpu = smp_processor_id();
386
387 desc->triggered = 1;
388
389 /*
390 * If we're currently running this IRQ, or its disabled,
391 * we shouldn't process the IRQ. Instead, turn on the
392 * hardware masks.
393 */
394 if (unlikely(desc->running || desc->disable_depth))
395 goto running;
396
397 /*
398 * Acknowledge and clear the IRQ, but don't mask it.
399 */
400 desc->chip->ack(irq);
401
402 /*
403 * Mark the IRQ currently in progress.
404 */
405 desc->running = 1;
406
407 kstat_cpu(cpu).irqs[irq]++;
408
409 do {
410 struct irqaction *action;
411
412 action = desc->action;
413 if (!action)
414 break;
415
416 if (desc->pending && !desc->disable_depth) {
417 desc->pending = 0;
418 desc->chip->unmask(irq);
419 }
420
421 __do_irq(irq, action, regs);
422 } while (desc->pending && !desc->disable_depth);
423
424 desc->running = 0;
425
426 /*
427 * If we were disabled or freed, shut down the handler.
428 */
429 if (likely(desc->action && !check_irq_lock(desc, irq, regs)))
430 return;
431
432 running:
433 /*
434 * We got another IRQ while this one was masked or
435 * currently running. Delay it.
436 */
437 desc->pending = 1;
438 desc->chip->mask(irq);
439 desc->chip->ack(irq);
440}
441
442/*
443 * Level-based IRQ handler. Nice and simple.
444 */
445void
446do_level_IRQ(unsigned int irq, struct irqdesc *desc, struct pt_regs *regs)
447{
448 struct irqaction *action;
449 const unsigned int cpu = smp_processor_id();
450
451 desc->triggered = 1;
452
453 /*
454 * Acknowledge, clear _AND_ disable the interrupt.
455 */
456 desc->chip->ack(irq);
457
458 if (likely(!desc->disable_depth)) {
459 kstat_cpu(cpu).irqs[irq]++;
460
461 smp_set_running(desc);
462
463 /*
464 * Return with this interrupt masked if no action
465 */
466 action = desc->action;
467 if (action) {
468 int ret = __do_irq(irq, desc->action, regs);
469
470 if (ret != IRQ_HANDLED)
471 report_bad_irq(irq, regs, desc, ret);
472
473 if (likely(!desc->disable_depth &&
474 !check_irq_lock(desc, irq, regs)))
475 desc->chip->unmask(irq);
476 }
477
478 smp_clear_running(desc);
479 }
480}
481
482static void do_pending_irqs(struct pt_regs *regs)
483{
484 struct list_head head, *l, *n;
485
486 do {
487 struct irqdesc *desc;
488
489 /*
490 * First, take the pending interrupts off the list.
491 * The act of calling the handlers may add some IRQs
492 * back onto the list.
493 */
494 head = irq_pending;
495 INIT_LIST_HEAD(&irq_pending);
496 head.next->prev = &head;
497 head.prev->next = &head;
498
499 /*
500 * Now run each entry. We must delete it from our
501 * list before calling the handler.
502 */
503 list_for_each_safe(l, n, &head) {
504 desc = list_entry(l, struct irqdesc, pend);
505 list_del_init(&desc->pend);
506 desc->handle(desc - irq_desc, desc, regs);
507 }
508
509 /*
510 * The list must be empty.
511 */
512 BUG_ON(!list_empty(&head));
513 } while (!list_empty(&irq_pending));
514}
515
516/*
517 * do_IRQ handles all hardware IRQ's. Decoded IRQs should not
518 * come via this function. Instead, they should provide their
519 * own 'handler'
520 */
521asmlinkage void asm_do_IRQ(unsigned int irq, struct pt_regs *regs)
522{
523 struct irqdesc *desc = irq_desc + irq;
524
525 /*
526 * Some hardware gives randomly wrong interrupts. Rather
527 * than crashing, do something sensible.
528 */
529 if (irq >= NR_IRQS)
530 desc = &bad_irq_desc;
531
532 irq_enter();
533 spin_lock(&irq_controller_lock);
534 desc->handle(irq, desc, regs);
535
536 /*
537 * Now re-run any pending interrupts.
538 */
539 if (!list_empty(&irq_pending))
540 do_pending_irqs(regs);
541
542 irq_finish(irq);
543
544 spin_unlock(&irq_controller_lock);
545 irq_exit();
546}
547
548void __set_irq_handler(unsigned int irq, irq_handler_t handle, int is_chained)
549{
550 struct irqdesc *desc;
551 unsigned long flags;
552
553 if (irq >= NR_IRQS) {
554 printk(KERN_ERR "Trying to install handler for IRQ%d\n", irq);
555 return;
556 }
557
558 if (handle == NULL)
559 handle = do_bad_IRQ;
560
561 desc = irq_desc + irq;
562
563 if (is_chained && desc->chip == &bad_chip)
564 printk(KERN_WARNING "Trying to install chained handler for IRQ%d\n", irq);
565
566 spin_lock_irqsave(&irq_controller_lock, flags);
567 if (handle == do_bad_IRQ) {
568 desc->chip->mask(irq);
569 desc->chip->ack(irq);
570 desc->disable_depth = 1;
571 }
572 desc->handle = handle;
573 if (handle != do_bad_IRQ && is_chained) {
574 desc->valid = 0;
575 desc->probe_ok = 0;
576 desc->disable_depth = 0;
577 desc->chip->unmask(irq);
578 }
579 spin_unlock_irqrestore(&irq_controller_lock, flags);
580}
581
582void set_irq_chip(unsigned int irq, struct irqchip *chip)
583{
584 struct irqdesc *desc;
585 unsigned long flags;
586
587 if (irq >= NR_IRQS) {
588 printk(KERN_ERR "Trying to install chip for IRQ%d\n", irq);
589 return;
590 }
591
592 if (chip == NULL)
593 chip = &bad_chip;
594
595 desc = irq_desc + irq;
596 spin_lock_irqsave(&irq_controller_lock, flags);
597 desc->chip = chip;
598 spin_unlock_irqrestore(&irq_controller_lock, flags);
599}
600
601int set_irq_type(unsigned int irq, unsigned int type)
602{
603 struct irqdesc *desc;
604 unsigned long flags;
605 int ret = -ENXIO;
606
607 if (irq >= NR_IRQS) {
608 printk(KERN_ERR "Trying to set irq type for IRQ%d\n", irq);
609 return -ENODEV;
610 }
611
612 desc = irq_desc + irq;
613 if (desc->chip->type) {
614 spin_lock_irqsave(&irq_controller_lock, flags);
615 ret = desc->chip->type(irq, type);
616 spin_unlock_irqrestore(&irq_controller_lock, flags);
617 }
618
619 return ret;
620}
621EXPORT_SYMBOL(set_irq_type);
622
623void set_irq_flags(unsigned int irq, unsigned int iflags)
624{
625 struct irqdesc *desc;
626 unsigned long flags;
627
628 if (irq >= NR_IRQS) {
629 printk(KERN_ERR "Trying to set irq flags for IRQ%d\n", irq);
630 return;
631 }
632
633 desc = irq_desc + irq;
634 spin_lock_irqsave(&irq_controller_lock, flags);
635 desc->valid = (iflags & IRQF_VALID) != 0;
636 desc->probe_ok = (iflags & IRQF_PROBE) != 0;
637 desc->noautoenable = (iflags & IRQF_NOAUTOEN) != 0;
638 spin_unlock_irqrestore(&irq_controller_lock, flags);
639}
640
641int setup_irq(unsigned int irq, struct irqaction *new)
642{
643 int shared = 0;
644 struct irqaction *old, **p;
645 unsigned long flags;
646 struct irqdesc *desc;
647
648 /*
649 * Some drivers like serial.c use request_irq() heavily,
650 * so we have to be careful not to interfere with a
651 * running system.
652 */
653 if (new->flags & SA_SAMPLE_RANDOM) {
654 /*
655 * This function might sleep, we want to call it first,
656 * outside of the atomic block.
657 * Yes, this might clear the entropy pool if the wrong
658 * driver is attempted to be loaded, without actually
659 * installing a new handler, but is this really a problem,
660 * only the sysadmin is able to do this.
661 */
662 rand_initialize_irq(irq);
663 }
664
665 /*
666 * The following block of code has to be executed atomically
667 */
668 desc = irq_desc + irq;
669 spin_lock_irqsave(&irq_controller_lock, flags);
670 p = &desc->action;
671 if ((old = *p) != NULL) {
672 /* Can't share interrupts unless both agree to */
673 if (!(old->flags & new->flags & SA_SHIRQ)) {
674 spin_unlock_irqrestore(&irq_controller_lock, flags);
675 return -EBUSY;
676 }
677
678 /* add new interrupt at end of irq queue */
679 do {
680 p = &old->next;
681 old = *p;
682 } while (old);
683 shared = 1;
684 }
685
686 *p = new;
687
688 if (!shared) {
689 desc->probing = 0;
690 desc->running = 0;
691 desc->pending = 0;
692 desc->disable_depth = 1;
693 if (!desc->noautoenable) {
694 desc->disable_depth = 0;
695 desc->chip->unmask(irq);
696 }
697 }
698
699 spin_unlock_irqrestore(&irq_controller_lock, flags);
700 return 0;
701}
702
703/**
704 * request_irq - allocate an interrupt line
705 * @irq: Interrupt line to allocate
706 * @handler: Function to be called when the IRQ occurs
707 * @irqflags: Interrupt type flags
708 * @devname: An ascii name for the claiming device
709 * @dev_id: A cookie passed back to the handler function
710 *
711 * This call allocates interrupt resources and enables the
712 * interrupt line and IRQ handling. From the point this
713 * call is made your handler function may be invoked. Since
714 * your handler function must clear any interrupt the board
715 * raises, you must take care both to initialise your hardware
716 * and to set up the interrupt handler in the right order.
717 *
718 * Dev_id must be globally unique. Normally the address of the
719 * device data structure is used as the cookie. Since the handler
720 * receives this value it makes sense to use it.
721 *
722 * If your interrupt is shared you must pass a non NULL dev_id
723 * as this is required when freeing the interrupt.
724 *
725 * Flags:
726 *
727 * SA_SHIRQ Interrupt is shared
728 *
729 * SA_INTERRUPT Disable local interrupts while processing
730 *
731 * SA_SAMPLE_RANDOM The interrupt can be used for entropy
732 *
733 */
734int request_irq(unsigned int irq, irqreturn_t (*handler)(int, void *, struct pt_regs *),
735 unsigned long irq_flags, const char * devname, void *dev_id)
736{
737 unsigned long retval;
738 struct irqaction *action;
739
740 if (irq >= NR_IRQS || !irq_desc[irq].valid || !handler ||
741 (irq_flags & SA_SHIRQ && !dev_id))
742 return -EINVAL;
743
744 action = (struct irqaction *)kmalloc(sizeof(struct irqaction), GFP_KERNEL);
745 if (!action)
746 return -ENOMEM;
747
748 action->handler = handler;
749 action->flags = irq_flags;
750 cpus_clear(action->mask);
751 action->name = devname;
752 action->next = NULL;
753 action->dev_id = dev_id;
754
755 retval = setup_irq(irq, action);
756
757 if (retval)
758 kfree(action);
759 return retval;
760}
761
762EXPORT_SYMBOL(request_irq);
763
764/**
765 * free_irq - free an interrupt
766 * @irq: Interrupt line to free
767 * @dev_id: Device identity to free
768 *
769 * Remove an interrupt handler. The handler is removed and if the
770 * interrupt line is no longer in use by any driver it is disabled.
771 * On a shared IRQ the caller must ensure the interrupt is disabled
772 * on the card it drives before calling this function.
773 *
774 * This function must not be called from interrupt context.
775 */
776void free_irq(unsigned int irq, void *dev_id)
777{
778 struct irqaction * action, **p;
779 unsigned long flags;
780
781 if (irq >= NR_IRQS || !irq_desc[irq].valid) {
782 printk(KERN_ERR "Trying to free IRQ%d\n",irq);
783 dump_stack();
784 return;
785 }
786
787 spin_lock_irqsave(&irq_controller_lock, flags);
788 for (p = &irq_desc[irq].action; (action = *p) != NULL; p = &action->next) {
789 if (action->dev_id != dev_id)
790 continue;
791
792 /* Found it - now free it */
793 *p = action->next;
794 break;
795 }
796 spin_unlock_irqrestore(&irq_controller_lock, flags);
797
798 if (!action) {
799 printk(KERN_ERR "Trying to free free IRQ%d\n",irq);
800 dump_stack();
801 } else {
802 synchronize_irq(irq);
803 kfree(action);
804 }
805}
806
807EXPORT_SYMBOL(free_irq);
808
809static DECLARE_MUTEX(probe_sem);
810
811/* Start the interrupt probing. Unlike other architectures,
812 * we don't return a mask of interrupts from probe_irq_on,
813 * but return the number of interrupts enabled for the probe.
814 * The interrupts which have been enabled for probing is
815 * instead recorded in the irq_desc structure.
816 */
817unsigned long probe_irq_on(void)
818{
819 unsigned int i, irqs = 0;
820 unsigned long delay;
821
822 down(&probe_sem);
823
824 /*
825 * first snaffle up any unassigned but
826 * probe-able interrupts
827 */
828 spin_lock_irq(&irq_controller_lock);
829 for (i = 0; i < NR_IRQS; i++) {
830 if (!irq_desc[i].probe_ok || irq_desc[i].action)
831 continue;
832
833 irq_desc[i].probing = 1;
834 irq_desc[i].triggered = 0;
835 if (irq_desc[i].chip->type)
836 irq_desc[i].chip->type(i, IRQT_PROBE);
837 irq_desc[i].chip->unmask(i);
838 irqs += 1;
839 }
840 spin_unlock_irq(&irq_controller_lock);
841
842 /*
843 * wait for spurious interrupts to mask themselves out again
844 */
845 for (delay = jiffies + HZ/10; time_before(jiffies, delay); )
846 /* min 100ms delay */;
847
848 /*
849 * now filter out any obviously spurious interrupts
850 */
851 spin_lock_irq(&irq_controller_lock);
852 for (i = 0; i < NR_IRQS; i++) {
853 if (irq_desc[i].probing && irq_desc[i].triggered) {
854 irq_desc[i].probing = 0;
855 irqs -= 1;
856 }
857 }
858 spin_unlock_irq(&irq_controller_lock);
859
860 return irqs;
861}
862
863EXPORT_SYMBOL(probe_irq_on);
864
865unsigned int probe_irq_mask(unsigned long irqs)
866{
867 unsigned int mask = 0, i;
868
869 spin_lock_irq(&irq_controller_lock);
870 for (i = 0; i < 16 && i < NR_IRQS; i++)
871 if (irq_desc[i].probing && irq_desc[i].triggered)
872 mask |= 1 << i;
873 spin_unlock_irq(&irq_controller_lock);
874
875 up(&probe_sem);
876
877 return mask;
878}
879EXPORT_SYMBOL(probe_irq_mask);
880
881/*
882 * Possible return values:
883 * >= 0 - interrupt number
884 * -1 - no interrupt/many interrupts
885 */
886int probe_irq_off(unsigned long irqs)
887{
888 unsigned int i;
889 int irq_found = NO_IRQ;
890
891 /*
892 * look at the interrupts, and find exactly one
893 * that we were probing has been triggered
894 */
895 spin_lock_irq(&irq_controller_lock);
896 for (i = 0; i < NR_IRQS; i++) {
897 if (irq_desc[i].probing &&
898 irq_desc[i].triggered) {
899 if (irq_found != NO_IRQ) {
900 irq_found = NO_IRQ;
901 goto out;
902 }
903 irq_found = i;
904 }
905 }
906
907 if (irq_found == -1)
908 irq_found = NO_IRQ;
909out:
910 spin_unlock_irq(&irq_controller_lock);
911
912 up(&probe_sem);
913
914 return irq_found;
915}
916
917EXPORT_SYMBOL(probe_irq_off);
918
919#ifdef CONFIG_SMP
920static void route_irq(struct irqdesc *desc, unsigned int irq, unsigned int cpu)
921{
922 pr_debug("IRQ%u: moving from cpu%u to cpu%u\n", irq, desc->cpu, cpu);
923
924 spin_lock_irq(&irq_controller_lock);
925 desc->cpu = cpu;
926 desc->chip->set_cpu(desc, irq, cpu);
927 spin_unlock_irq(&irq_controller_lock);
928}
929
930#ifdef CONFIG_PROC_FS
931static int
932irq_affinity_read_proc(char *page, char **start, off_t off, int count,
933 int *eof, void *data)
934{
935 struct irqdesc *desc = irq_desc + ((int)data);
936 int len = cpumask_scnprintf(page, count, desc->affinity);
937
938 if (count - len < 2)
939 return -EINVAL;
940 page[len++] = '\n';
941 page[len] = '\0';
942
943 return len;
944}
945
946static int
947irq_affinity_write_proc(struct file *file, const char __user *buffer,
948 unsigned long count, void *data)
949{
950 unsigned int irq = (unsigned int)data;
951 struct irqdesc *desc = irq_desc + irq;
952 cpumask_t affinity, tmp;
953 int ret = -EIO;
954
955 if (!desc->chip->set_cpu)
956 goto out;
957
958 ret = cpumask_parse(buffer, count, affinity);
959 if (ret)
960 goto out;
961
962 cpus_and(tmp, affinity, cpu_online_map);
963 if (cpus_empty(tmp)) {
964 ret = -EINVAL;
965 goto out;
966 }
967
968 desc->affinity = affinity;
969 route_irq(desc, irq, first_cpu(tmp));
970 ret = count;
971
972 out:
973 return ret;
974}
975#endif
976#endif
977
978void __init init_irq_proc(void)
979{
980#if defined(CONFIG_SMP) && defined(CONFIG_PROC_FS)
981 struct proc_dir_entry *dir;
982 int irq;
983
984 dir = proc_mkdir("irq", 0);
985 if (!dir)
986 return;
987
988 for (irq = 0; irq < NR_IRQS; irq++) {
989 struct proc_dir_entry *entry;
990 struct irqdesc *desc;
991 char name[16];
992
993 desc = irq_desc + irq;
994 memset(name, 0, sizeof(name));
995 snprintf(name, sizeof(name) - 1, "%u", irq);
996
997 desc->procdir = proc_mkdir(name, dir);
998 if (!desc->procdir)
999 continue;
1000
1001 entry = create_proc_entry("smp_affinity", 0600, desc->procdir);
1002 if (entry) {
1003 entry->nlink = 1;
1004 entry->data = (void *)irq;
1005 entry->read_proc = irq_affinity_read_proc;
1006 entry->write_proc = irq_affinity_write_proc;
1007 }
1008 }
1009#endif
1010}
1011
1012void __init init_IRQ(void)
1013{
1014 struct irqdesc *desc;
1015 extern void init_dma(void);
1016 int irq;
1017
1018#ifdef CONFIG_SMP
1019 bad_irq_desc.affinity = CPU_MASK_ALL;
1020 bad_irq_desc.cpu = smp_processor_id();
1021#endif
1022
1023 for (irq = 0, desc = irq_desc; irq < NR_IRQS; irq++, desc++) {
1024 *desc = bad_irq_desc;
1025 INIT_LIST_HEAD(&desc->pend);
1026 }
1027
1028 init_arch_irq();
1029 init_dma();
1030}
1031
1032static int __init noirqdebug_setup(char *str)
1033{
1034 noirqdebug = 1;
1035 return 1;
1036}
1037
1038__setup("noirqdebug", noirqdebug_setup);