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authorLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 18:20:36 -0400
committerLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 18:20:36 -0400
commit1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch)
tree0bba044c4ce775e45a88a51686b5d9f90697ea9d /arch/frv/kernel/irq.c
Linux-2.6.12-rc2v2.6.12-rc2
Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
Diffstat (limited to 'arch/frv/kernel/irq.c')
-rw-r--r--arch/frv/kernel/irq.c764
1 files changed, 764 insertions, 0 deletions
diff --git a/arch/frv/kernel/irq.c b/arch/frv/kernel/irq.c
new file mode 100644
index 000000000000..8c524cdd2717
--- /dev/null
+++ b/arch/frv/kernel/irq.c
@@ -0,0 +1,764 @@
1/* irq.c: FRV IRQ handling
2 *
3 * Copyright (C) 2003, 2004 Red Hat, Inc. All Rights Reserved.
4 * Written by David Howells (dhowells@redhat.com)
5 *
6 * This program is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU General Public License
8 * as published by the Free Software Foundation; either version
9 * 2 of the License, or (at your option) any later version.
10 */
11
12/*
13 * (mostly architecture independent, will move to kernel/irq.c in 2.5.)
14 *
15 * IRQs are in fact implemented a bit like signal handlers for the kernel.
16 * Naturally it's not a 1:1 relation, but there are similarities.
17 */
18
19#include <linux/config.h>
20#include <linux/ptrace.h>
21#include <linux/errno.h>
22#include <linux/signal.h>
23#include <linux/sched.h>
24#include <linux/ioport.h>
25#include <linux/interrupt.h>
26#include <linux/timex.h>
27#include <linux/slab.h>
28#include <linux/random.h>
29#include <linux/smp_lock.h>
30#include <linux/init.h>
31#include <linux/kernel_stat.h>
32#include <linux/irq.h>
33#include <linux/proc_fs.h>
34#include <linux/seq_file.h>
35
36#include <asm/atomic.h>
37#include <asm/io.h>
38#include <asm/smp.h>
39#include <asm/system.h>
40#include <asm/bitops.h>
41#include <asm/uaccess.h>
42#include <asm/pgalloc.h>
43#include <asm/delay.h>
44#include <asm/irq.h>
45#include <asm/irc-regs.h>
46#include <asm/irq-routing.h>
47#include <asm/gdb-stub.h>
48
49extern void __init fpga_init(void);
50extern void __init route_mb93493_irqs(void);
51
52static void register_irq_proc (unsigned int irq);
53
54/*
55 * Special irq handlers.
56 */
57
58irqreturn_t no_action(int cpl, void *dev_id, struct pt_regs *regs) { return IRQ_HANDLED; }
59
60atomic_t irq_err_count;
61
62/*
63 * Generic, controller-independent functions:
64 */
65int show_interrupts(struct seq_file *p, void *v)
66{
67 struct irqaction *action;
68 struct irq_group *group;
69 unsigned long flags;
70 int level, grp, ix, i, j;
71
72 i = *(loff_t *) v;
73
74 switch (i) {
75 case 0:
76 seq_printf(p, " ");
77 for (j = 0; j < NR_CPUS; j++)
78 if (cpu_online(j))
79 seq_printf(p, "CPU%d ",j);
80
81 seq_putc(p, '\n');
82 break;
83
84 case 1 ... NR_IRQ_GROUPS * NR_IRQ_ACTIONS_PER_GROUP:
85 local_irq_save(flags);
86
87 grp = (i - 1) / NR_IRQ_ACTIONS_PER_GROUP;
88 group = irq_groups[grp];
89 if (!group)
90 goto skip;
91
92 ix = (i - 1) % NR_IRQ_ACTIONS_PER_GROUP;
93 action = group->actions[ix];
94 if (!action)
95 goto skip;
96
97 seq_printf(p, "%3d: ", i - 1);
98
99#ifndef CONFIG_SMP
100 seq_printf(p, "%10u ", kstat_irqs(i));
101#else
102 for (j = 0; j < NR_CPUS; j++)
103 if (cpu_online(j))
104 seq_printf(p, "%10u ", kstat_cpu(j).irqs[i - 1]);
105#endif
106
107 level = group->sources[ix]->level - frv_irq_levels;
108
109 seq_printf(p, " %12s@%x", group->sources[ix]->muxname, level);
110 seq_printf(p, " %s", action->name);
111
112 for (action = action->next; action; action = action->next)
113 seq_printf(p, ", %s", action->name);
114
115 seq_putc(p, '\n');
116skip:
117 local_irq_restore(flags);
118 break;
119
120 case NR_IRQ_GROUPS * NR_IRQ_ACTIONS_PER_GROUP + 1:
121 seq_printf(p, "ERR: %10u\n", atomic_read(&irq_err_count));
122 break;
123
124 default:
125 break;
126 }
127
128 return 0;
129}
130
131
132/*
133 * Generic enable/disable code: this just calls
134 * down into the PIC-specific version for the actual
135 * hardware disable after having gotten the irq
136 * controller lock.
137 */
138
139/**
140 * disable_irq_nosync - disable an irq without waiting
141 * @irq: Interrupt to disable
142 *
143 * Disable the selected interrupt line. Disables and Enables are
144 * nested.
145 * Unlike disable_irq(), this function does not ensure existing
146 * instances of the IRQ handler have completed before returning.
147 *
148 * This function may be called from IRQ context.
149 */
150
151void disable_irq_nosync(unsigned int irq)
152{
153 struct irq_source *source;
154 struct irq_group *group;
155 struct irq_level *level;
156 unsigned long flags;
157 int idx = irq & (NR_IRQ_ACTIONS_PER_GROUP - 1);
158
159 group = irq_groups[irq >> NR_IRQ_LOG2_ACTIONS_PER_GROUP];
160 if (!group)
161 BUG();
162
163 source = group->sources[idx];
164 if (!source)
165 BUG();
166
167 level = source->level;
168
169 spin_lock_irqsave(&level->lock, flags);
170
171 if (group->control) {
172 if (!group->disable_cnt[idx]++)
173 group->control(group, idx, 0);
174 } else if (!level->disable_count++) {
175 __set_MASK(level - frv_irq_levels);
176 }
177
178 spin_unlock_irqrestore(&level->lock, flags);
179}
180
181/**
182 * disable_irq - disable an irq and wait for completion
183 * @irq: Interrupt to disable
184 *
185 * Disable the selected interrupt line. Enables and Disables are
186 * nested.
187 * This function waits for any pending IRQ handlers for this interrupt
188 * to complete before returning. If you use this function while
189 * holding a resource the IRQ handler may need you will deadlock.
190 *
191 * This function may be called - with care - from IRQ context.
192 */
193
194void disable_irq(unsigned int irq)
195{
196 disable_irq_nosync(irq);
197
198#ifdef CONFIG_SMP
199 if (!local_irq_count(smp_processor_id())) {
200 do {
201 barrier();
202 } while (irq_desc[irq].status & IRQ_INPROGRESS);
203 }
204#endif
205}
206
207/**
208 * enable_irq - enable handling of an irq
209 * @irq: Interrupt to enable
210 *
211 * Undoes the effect of one call to disable_irq(). If this
212 * matches the last disable, processing of interrupts on this
213 * IRQ line is re-enabled.
214 *
215 * This function may be called from IRQ context.
216 */
217
218void enable_irq(unsigned int irq)
219{
220 struct irq_source *source;
221 struct irq_group *group;
222 struct irq_level *level;
223 unsigned long flags;
224 int idx = irq & (NR_IRQ_ACTIONS_PER_GROUP - 1);
225 int count;
226
227 group = irq_groups[irq >> NR_IRQ_LOG2_ACTIONS_PER_GROUP];
228 if (!group)
229 BUG();
230
231 source = group->sources[idx];
232 if (!source)
233 BUG();
234
235 level = source->level;
236
237 spin_lock_irqsave(&level->lock, flags);
238
239 if (group->control)
240 count = group->disable_cnt[idx];
241 else
242 count = level->disable_count;
243
244 switch (count) {
245 case 1:
246 if (group->control) {
247 if (group->actions[idx])
248 group->control(group, idx, 1);
249 } else {
250 if (level->usage)
251 __clr_MASK(level - frv_irq_levels);
252 }
253 /* fall-through */
254
255 default:
256 count--;
257 break;
258
259 case 0:
260 printk("enable_irq(%u) unbalanced from %p\n", irq, __builtin_return_address(0));
261 }
262
263 if (group->control)
264 group->disable_cnt[idx] = count;
265 else
266 level->disable_count = count;
267
268 spin_unlock_irqrestore(&level->lock, flags);
269}
270
271/*****************************************************************************/
272/*
273 * handles all normal device IRQ's
274 * - registers are referred to by the __frame variable (GR28)
275 * - IRQ distribution is complicated in this arch because of the many PICs, the
276 * way they work and the way they cascade
277 */
278asmlinkage void do_IRQ(void)
279{
280 struct irq_source *source;
281 int level, cpu;
282
283 level = (__frame->tbr >> 4) & 0xf;
284 cpu = smp_processor_id();
285
286#if 0
287 {
288 static u32 irqcount;
289 *(volatile u32 *) 0xe1200004 = ~((irqcount++ << 8) | level);
290 *(volatile u16 *) 0xffc00100 = (u16) ~0x9999;
291 mb();
292 }
293#endif
294
295 if ((unsigned long) __frame - (unsigned long) (current + 1) < 512)
296 BUG();
297
298 __set_MASK(level);
299 __clr_RC(level);
300 __clr_IRL();
301
302 kstat_this_cpu.irqs[level]++;
303
304 irq_enter();
305
306 for (source = frv_irq_levels[level].sources; source; source = source->next)
307 source->doirq(source);
308
309 irq_exit();
310
311 __clr_MASK(level);
312
313 /* only process softirqs if we didn't interrupt another interrupt handler */
314 if ((__frame->psr & PSR_PIL) == PSR_PIL_0)
315 if (local_softirq_pending())
316 do_softirq();
317
318#ifdef CONFIG_PREEMPT
319 local_irq_disable();
320 while (--current->preempt_count == 0) {
321 if (!(__frame->psr & PSR_S) ||
322 current->need_resched == 0 ||
323 in_interrupt())
324 break;
325 current->preempt_count++;
326 local_irq_enable();
327 preempt_schedule();
328 local_irq_disable();
329 }
330#endif
331
332#if 0
333 {
334 *(volatile u16 *) 0xffc00100 = (u16) ~0x6666;
335 mb();
336 }
337#endif
338
339} /* end do_IRQ() */
340
341/*****************************************************************************/
342/*
343 * handles all NMIs when not co-opted by the debugger
344 * - registers are referred to by the __frame variable (GR28)
345 */
346asmlinkage void do_NMI(void)
347{
348} /* end do_NMI() */
349
350/*****************************************************************************/
351/**
352 * request_irq - allocate an interrupt line
353 * @irq: Interrupt line to allocate
354 * @handler: Function to be called when the IRQ occurs
355 * @irqflags: Interrupt type flags
356 * @devname: An ascii name for the claiming device
357 * @dev_id: A cookie passed back to the handler function
358 *
359 * This call allocates interrupt resources and enables the
360 * interrupt line and IRQ handling. From the point this
361 * call is made your handler function may be invoked. Since
362 * your handler function must clear any interrupt the board
363 * raises, you must take care both to initialise your hardware
364 * and to set up the interrupt handler in the right order.
365 *
366 * Dev_id must be globally unique. Normally the address of the
367 * device data structure is used as the cookie. Since the handler
368 * receives this value it makes sense to use it.
369 *
370 * If your interrupt is shared you must pass a non NULL dev_id
371 * as this is required when freeing the interrupt.
372 *
373 * Flags:
374 *
375 * SA_SHIRQ Interrupt is shared
376 *
377 * SA_INTERRUPT Disable local interrupts while processing
378 *
379 * SA_SAMPLE_RANDOM The interrupt can be used for entropy
380 *
381 */
382
383int request_irq(unsigned int irq,
384 irqreturn_t (*handler)(int, void *, struct pt_regs *),
385 unsigned long irqflags,
386 const char * devname,
387 void *dev_id)
388{
389 int retval;
390 struct irqaction *action;
391
392#if 1
393 /*
394 * Sanity-check: shared interrupts should REALLY pass in
395 * a real dev-ID, otherwise we'll have trouble later trying
396 * to figure out which interrupt is which (messes up the
397 * interrupt freeing logic etc).
398 */
399 if (irqflags & SA_SHIRQ) {
400 if (!dev_id)
401 printk("Bad boy: %s (at 0x%x) called us without a dev_id!\n",
402 devname, (&irq)[-1]);
403 }
404#endif
405
406 if ((irq >> NR_IRQ_LOG2_ACTIONS_PER_GROUP) >= NR_IRQ_GROUPS)
407 return -EINVAL;
408 if (!handler)
409 return -EINVAL;
410
411 action = (struct irqaction *) kmalloc(sizeof(struct irqaction), GFP_KERNEL);
412 if (!action)
413 return -ENOMEM;
414
415 action->handler = handler;
416 action->flags = irqflags;
417 action->mask = CPU_MASK_NONE;
418 action->name = devname;
419 action->next = NULL;
420 action->dev_id = dev_id;
421
422 retval = setup_irq(irq, action);
423 if (retval)
424 kfree(action);
425 return retval;
426}
427
428/**
429 * free_irq - free an interrupt
430 * @irq: Interrupt line to free
431 * @dev_id: Device identity to free
432 *
433 * Remove an interrupt handler. The handler is removed and if the
434 * interrupt line is no longer in use by any driver it is disabled.
435 * On a shared IRQ the caller must ensure the interrupt is disabled
436 * on the card it drives before calling this function. The function
437 * does not return until any executing interrupts for this IRQ
438 * have completed.
439 *
440 * This function may be called from interrupt context.
441 *
442 * Bugs: Attempting to free an irq in a handler for the same irq hangs
443 * the machine.
444 */
445
446void free_irq(unsigned int irq, void *dev_id)
447{
448 struct irq_source *source;
449 struct irq_group *group;
450 struct irq_level *level;
451 struct irqaction **p, **pp;
452 unsigned long flags;
453
454 if ((irq >> NR_IRQ_LOG2_ACTIONS_PER_GROUP) >= NR_IRQ_GROUPS)
455 return;
456
457 group = irq_groups[irq >> NR_IRQ_LOG2_ACTIONS_PER_GROUP];
458 if (!group)
459 BUG();
460
461 source = group->sources[irq & (NR_IRQ_ACTIONS_PER_GROUP - 1)];
462 if (!source)
463 BUG();
464
465 level = source->level;
466 p = &group->actions[irq & (NR_IRQ_ACTIONS_PER_GROUP - 1)];
467
468 spin_lock_irqsave(&level->lock, flags);
469
470 for (pp = p; *pp; pp = &(*pp)->next) {
471 struct irqaction *action = *pp;
472
473 if (action->dev_id != dev_id)
474 continue;
475
476 /* found it - remove from the list of entries */
477 *pp = action->next;
478
479 level->usage--;
480
481 if (p == pp && group->control)
482 group->control(group, irq & (NR_IRQ_ACTIONS_PER_GROUP - 1), 0);
483
484 if (level->usage == 0)
485 __set_MASK(level - frv_irq_levels);
486
487 spin_unlock_irqrestore(&level->lock,flags);
488
489#ifdef CONFIG_SMP
490 /* Wait to make sure it's not being used on another CPU */
491 while (desc->status & IRQ_INPROGRESS)
492 barrier();
493#endif
494 kfree(action);
495 return;
496 }
497}
498
499/*
500 * IRQ autodetection code..
501 *
502 * This depends on the fact that any interrupt that comes in on to an
503 * unassigned IRQ will cause GxICR_DETECT to be set
504 */
505
506static DECLARE_MUTEX(probe_sem);
507
508/**
509 * probe_irq_on - begin an interrupt autodetect
510 *
511 * Commence probing for an interrupt. The interrupts are scanned
512 * and a mask of potential interrupt lines is returned.
513 *
514 */
515
516unsigned long probe_irq_on(void)
517{
518 down(&probe_sem);
519 return 0;
520}
521
522/*
523 * Return a mask of triggered interrupts (this
524 * can handle only legacy ISA interrupts).
525 */
526
527/**
528 * probe_irq_mask - scan a bitmap of interrupt lines
529 * @val: mask of interrupts to consider
530 *
531 * Scan the ISA bus interrupt lines and return a bitmap of
532 * active interrupts. The interrupt probe logic state is then
533 * returned to its previous value.
534 *
535 * Note: we need to scan all the irq's even though we will
536 * only return ISA irq numbers - just so that we reset them
537 * all to a known state.
538 */
539unsigned int probe_irq_mask(unsigned long xmask)
540{
541 up(&probe_sem);
542 return 0;
543}
544
545/*
546 * Return the one interrupt that triggered (this can
547 * handle any interrupt source).
548 */
549
550/**
551 * probe_irq_off - end an interrupt autodetect
552 * @xmask: mask of potential interrupts (unused)
553 *
554 * Scans the unused interrupt lines and returns the line which
555 * appears to have triggered the interrupt. If no interrupt was
556 * found then zero is returned. If more than one interrupt is
557 * found then minus the first candidate is returned to indicate
558 * their is doubt.
559 *
560 * The interrupt probe logic state is returned to its previous
561 * value.
562 *
563 * BUGS: When used in a module (which arguably shouldnt happen)
564 * nothing prevents two IRQ probe callers from overlapping. The
565 * results of this are non-optimal.
566 */
567
568int probe_irq_off(unsigned long xmask)
569{
570 up(&probe_sem);
571 return -1;
572}
573
574/* this was setup_x86_irq but it seems pretty generic */
575int setup_irq(unsigned int irq, struct irqaction *new)
576{
577 struct irq_source *source;
578 struct irq_group *group;
579 struct irq_level *level;
580 struct irqaction **p, **pp;
581 unsigned long flags;
582
583 group = irq_groups[irq >> NR_IRQ_LOG2_ACTIONS_PER_GROUP];
584 if (!group)
585 BUG();
586
587 source = group->sources[irq & (NR_IRQ_ACTIONS_PER_GROUP - 1)];
588 if (!source)
589 BUG();
590
591 level = source->level;
592
593 p = &group->actions[irq & (NR_IRQ_ACTIONS_PER_GROUP - 1)];
594
595 /*
596 * Some drivers like serial.c use request_irq() heavily,
597 * so we have to be careful not to interfere with a
598 * running system.
599 */
600 if (new->flags & SA_SAMPLE_RANDOM) {
601 /*
602 * This function might sleep, we want to call it first,
603 * outside of the atomic block.
604 * Yes, this might clear the entropy pool if the wrong
605 * driver is attempted to be loaded, without actually
606 * installing a new handler, but is this really a problem,
607 * only the sysadmin is able to do this.
608 */
609 rand_initialize_irq(irq);
610 }
611
612 /* must juggle the interrupt processing stuff with interrupts disabled */
613 spin_lock_irqsave(&level->lock, flags);
614
615 /* can't share interrupts unless all parties agree to */
616 if (level->usage != 0 && !(level->flags & new->flags & SA_SHIRQ)) {
617 spin_unlock_irqrestore(&level->lock,flags);
618 return -EBUSY;
619 }
620
621 /* add new interrupt at end of irq queue */
622 pp = p;
623 while (*pp)
624 pp = &(*pp)->next;
625
626 *pp = new;
627
628 level->usage++;
629 level->flags = new->flags;
630
631 /* turn the interrupts on */
632 if (level->usage == 1)
633 __clr_MASK(level - frv_irq_levels);
634
635 if (p == pp && group->control)
636 group->control(group, irq & (NR_IRQ_ACTIONS_PER_GROUP - 1), 1);
637
638 spin_unlock_irqrestore(&level->lock, flags);
639 register_irq_proc(irq);
640 return 0;
641}
642
643static struct proc_dir_entry * root_irq_dir;
644static struct proc_dir_entry * irq_dir [NR_IRQS];
645
646#define HEX_DIGITS 8
647
648static unsigned int parse_hex_value (const char *buffer,
649 unsigned long count, unsigned long *ret)
650{
651 unsigned char hexnum [HEX_DIGITS];
652 unsigned long value;
653 int i;
654
655 if (!count)
656 return -EINVAL;
657 if (count > HEX_DIGITS)
658 count = HEX_DIGITS;
659 if (copy_from_user(hexnum, buffer, count))
660 return -EFAULT;
661
662 /*
663 * Parse the first 8 characters as a hex string, any non-hex char
664 * is end-of-string. '00e1', 'e1', '00E1', 'E1' are all the same.
665 */
666 value = 0;
667
668 for (i = 0; i < count; i++) {
669 unsigned int c = hexnum[i];
670
671 switch (c) {
672 case '0' ... '9': c -= '0'; break;
673 case 'a' ... 'f': c -= 'a'-10; break;
674 case 'A' ... 'F': c -= 'A'-10; break;
675 default:
676 goto out;
677 }
678 value = (value << 4) | c;
679 }
680out:
681 *ret = value;
682 return 0;
683}
684
685
686static int prof_cpu_mask_read_proc (char *page, char **start, off_t off,
687 int count, int *eof, void *data)
688{
689 unsigned long *mask = (unsigned long *) data;
690 if (count < HEX_DIGITS+1)
691 return -EINVAL;
692 return sprintf (page, "%08lx\n", *mask);
693}
694
695static int prof_cpu_mask_write_proc (struct file *file, const char *buffer,
696 unsigned long count, void *data)
697{
698 unsigned long *mask = (unsigned long *) data, full_count = count, err;
699 unsigned long new_value;
700
701 show_state();
702 err = parse_hex_value(buffer, count, &new_value);
703 if (err)
704 return err;
705
706 *mask = new_value;
707 return full_count;
708}
709
710#define MAX_NAMELEN 10
711
712static void register_irq_proc (unsigned int irq)
713{
714 char name [MAX_NAMELEN];
715
716 if (!root_irq_dir || irq_dir[irq])
717 return;
718
719 memset(name, 0, MAX_NAMELEN);
720 sprintf(name, "%d", irq);
721
722 /* create /proc/irq/1234 */
723 irq_dir[irq] = proc_mkdir(name, root_irq_dir);
724}
725
726unsigned long prof_cpu_mask = -1;
727
728void init_irq_proc (void)
729{
730 struct proc_dir_entry *entry;
731 int i;
732
733 /* create /proc/irq */
734 root_irq_dir = proc_mkdir("irq", 0);
735
736 /* create /proc/irq/prof_cpu_mask */
737 entry = create_proc_entry("prof_cpu_mask", 0600, root_irq_dir);
738 if (!entry)
739 return;
740
741 entry->nlink = 1;
742 entry->data = (void *)&prof_cpu_mask;
743 entry->read_proc = prof_cpu_mask_read_proc;
744 entry->write_proc = prof_cpu_mask_write_proc;
745
746 /*
747 * Create entries for all existing IRQs.
748 */
749 for (i = 0; i < NR_IRQS; i++)
750 register_irq_proc(i);
751}
752
753/*****************************************************************************/
754/*
755 * initialise the interrupt system
756 */
757void __init init_IRQ(void)
758{
759 route_cpu_irqs();
760 fpga_init();
761#ifdef CONFIG_FUJITSU_MB93493
762 route_mb93493_irqs();
763#endif
764} /* end init_IRQ() */