aboutsummaryrefslogtreecommitdiffstats
path: root/arch/frv/kernel/irq.c
blob: 08967010be04a5c702ad1d42e9e96e6df47534a3 (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
/* irq.c: FRV IRQ handling
 *
 * Copyright (C) 2003, 2004 Red Hat, Inc. All Rights Reserved.
 * Written by David Howells (dhowells@redhat.com)
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version
 * 2 of the License, or (at your option) any later version.
 */

/*
 * (mostly architecture independent, will move to kernel/irq.c in 2.5.)
 *
 * IRQs are in fact implemented a bit like signal handlers for the kernel.
 * Naturally it's not a 1:1 relation, but there are similarities.
 */

#include <linux/ptrace.h>
#include <linux/errno.h>
#include <linux/signal.h>
#include <linux/sched.h>
#include <linux/ioport.h>
#include <linux/interrupt.h>
#include <linux/timex.h>
#include <linux/slab.h>
#include <linux/random.h>
#include <linux/smp_lock.h>
#include <linux/init.h>
#include <linux/kernel_stat.h>
#include <linux/irq.h>
#include <linux/proc_fs.h>
#include <linux/seq_file.h>
#include <linux/module.h>

#include <asm/atomic.h>
#include <asm/io.h>
#include <asm/smp.h>
#include <asm/system.h>
#include <asm/bitops.h>
#include <asm/uaccess.h>
#include <asm/pgalloc.h>
#include <asm/delay.h>
#include <asm/irq.h>
#include <asm/irc-regs.h>
#include <asm/irq-routing.h>
#include <asm/gdb-stub.h>

extern void __init fpga_init(void);
extern void __init route_mb93493_irqs(void);

static void register_irq_proc (unsigned int irq);

/*
 * Special irq handlers.
 */

irqreturn_t no_action(int cpl, void *dev_id, struct pt_regs *regs) { return IRQ_HANDLED; }

atomic_t irq_err_count;

/*
 * Generic, controller-independent functions:
 */
int show_interrupts(struct seq_file *p, void *v)
{
	struct irqaction *action;
	struct irq_group *group;
	unsigned long flags;
	int level, grp, ix, i, j;

	i = *(loff_t *) v;

	switch (i) {
	case 0:
		seq_printf(p, "           ");
		for_each_online_cpu(j)
			seq_printf(p, "CPU%d       ",j);

		seq_putc(p, '\n');
		break;

	case 1 ... NR_IRQ_GROUPS * NR_IRQ_ACTIONS_PER_GROUP:
		local_irq_save(flags);

		grp = (i - 1) / NR_IRQ_ACTIONS_PER_GROUP;
		group = irq_groups[grp];
		if (!group)
			goto skip;

		ix = (i - 1) % NR_IRQ_ACTIONS_PER_GROUP;
		action = group->actions[ix];
		if (!action)
			goto skip;

		seq_printf(p, "%3d: ", i - 1);

#ifndef CONFIG_SMP
		seq_printf(p, "%10u ", kstat_irqs(i));
#else
		for_each_online_cpu(j)
			seq_printf(p, "%10u ", kstat_cpu(j).irqs[i - 1]);
#endif

		level = group->sources[ix]->level - frv_irq_levels;

		seq_printf(p, " %12s@%x", group->sources[ix]->muxname, level);
		seq_printf(p, "  %s", action->name);

		for (action = action->next; action; action = action->next)
			seq_printf(p, ", %s", action->name);

		seq_putc(p, '\n');
skip:
		local_irq_restore(flags);
		break;

	case NR_IRQ_GROUPS * NR_IRQ_ACTIONS_PER_GROUP + 1:
		seq_printf(p, "ERR: %10u\n", atomic_read(&irq_err_count));
		break;

	default:
		break;
	}

	return 0;
}


/*
 * Generic enable/disable code: this just calls
 * down into the PIC-specific version for the actual
 * hardware disable after having gotten the irq
 * controller lock.
 */

/**
 *	disable_irq_nosync - disable an irq without waiting
 *	@irq: Interrupt to disable
 *
 *	Disable the selected interrupt line.  Disables and Enables are
 *	nested.
 *	Unlike disable_irq(), this function does not ensure existing
 *	instances of the IRQ handler have completed before returning.
 *
 *	This function may be called from IRQ context.
 */

void disable_irq_nosync(unsigned int irq)
{
	struct irq_source *source;
	struct irq_group *group;
	struct irq_level *level;
	unsigned long flags;
	int idx = irq & (NR_IRQ_ACTIONS_PER_GROUP - 1);

	group = irq_groups[irq >> NR_IRQ_LOG2_ACTIONS_PER_GROUP];
	if (!group)
		BUG();

	source = group->sources[idx];
	if (!source)
		BUG();

	level = source->level;

	spin_lock_irqsave(&level->lock, flags);

	if (group->control) {
		if (!group->disable_cnt[idx]++)
			group->control(group, idx, 0);
	} else if (!level->disable_count++) {
		__set_MASK(level - frv_irq_levels);
	}

	spin_unlock_irqrestore(&level->lock, flags);
}

EXPORT_SYMBOL(disable_irq_nosync);

/**
 *	disable_irq - disable an irq and wait for completion
 *	@irq: Interrupt to disable
 *
 *	Disable the selected interrupt line.  Enables and Disables are
 *	nested.
 *	This function waits for any pending IRQ handlers for this interrupt
 *	to complete before returning. If you use this function while
 *	holding a resource the IRQ handler may need you will deadlock.
 *
 *	This function may be called - with care - from IRQ context.
 */

void disable_irq(unsigned int irq)
{
	disable_irq_nosync(irq);

#ifdef CONFIG_SMP
	if (!local_irq_count(smp_processor_id())) {
		do {
			barrier();
		} while (irq_desc[irq].status & IRQ_INPROGRESS);
	}
#endif
}

EXPORT_SYMBOL(disable_irq);

/**
 *	enable_irq - enable handling of an irq
 *	@irq: Interrupt to enable
 *
 *	Undoes the effect of one call to disable_irq().  If this
 *	matches the last disable, processing of interrupts on this
 *	IRQ line is re-enabled.
 *
 *	This function may be called from IRQ context.
 */

void enable_irq(unsigned int irq)
{
	struct irq_source *source;
	struct irq_group *group;
	struct irq_level *level;
	unsigned long flags;
	int idx = irq & (NR_IRQ_ACTIONS_PER_GROUP - 1);
	int count;

	group = irq_groups[irq >> NR_IRQ_LOG2_ACTIONS_PER_GROUP];
	if (!group)
		BUG();

	source = group->sources[idx];
	if (!source)
		BUG();

	level = source->level;

	spin_lock_irqsave(&level->lock, flags);

	if (group->control)
		count = group->disable_cnt[idx];
	else
		count = level->disable_count;

	switch (count) {
	case 1:
		if (group->control) {
			if (group->actions[idx])
				group->control(group, idx, 1);
		} else {
			if (level->usage)
				__clr_MASK(level - frv_irq_levels);
		}
		/* fall-through */

	default:
		count--;
		break;

	case 0:
		printk("enable_irq(%u) unbalanced from %p\n", irq, __builtin_return_address(0));
	}

	if (group->control)
		group->disable_cnt[idx] = count;
	else
		level->disable_count = count;

	spin_unlock_irqrestore(&level->lock, flags);
}

EXPORT_SYMBOL(enable_irq);

/*****************************************************************************/
/*
 * handles all normal device IRQ's
 * - registers are referred to by the __frame variable (GR28)
 * - IRQ distribution is complicated in this arch because of the many PICs, the
 *   way they work and the way they cascade
 */
asmlinkage void do_IRQ(void)
{
	struct irq_source *source;
	int level, cpu;

	irq_enter();

	level = (__frame->tbr >> 4) & 0xf;
	cpu = smp_processor_id();

	if ((unsigned long) __frame - (unsigned long) (current + 1) < 512)
		BUG();

	__set_MASK(level);
	__clr_RC(level);
	__clr_IRL();

	kstat_this_cpu.irqs[level]++;

	for (source = frv_irq_levels[level].sources; source; source = source->next)
		source->doirq(source);

	__clr_MASK(level);

	irq_exit();

} /* end do_IRQ() */

/*****************************************************************************/
/*
 * handles all NMIs when not co-opted by the debugger
 * - registers are referred to by the __frame variable (GR28)
 */
asmlinkage void do_NMI(void)
{
} /* end do_NMI() */

/*****************************************************************************/
/**
 *	request_irq - allocate an interrupt line
 *	@irq: Interrupt line to allocate
 *	@handler: Function to be called when the IRQ occurs
 *	@irqflags: Interrupt type flags
 *	@devname: An ascii name for the claiming device
 *	@dev_id: A cookie passed back to the handler function
 *
 *	This call allocates interrupt resources and enables the
 *	interrupt line and IRQ handling. From the point this
 *	call is made your handler function may be invoked. Since
 *	your handler function must clear any interrupt the board
 *	raises, you must take care both to initialise your hardware
 *	and to set up the interrupt handler in the right order.
 *
 *	Dev_id must be globally unique. Normally the address of the
 *	device data structure is used as the cookie. Since the handler
 *	receives this value it makes sense to use it.
 *
 *	If your interrupt is shared you must pass a non NULL dev_id
 *	as this is required when freeing the interrupt.
 *
 *	Flags:
 *
 *	IRQF_SHARED		Interrupt is shared
 *
 *	IRQF_DISABLED	Disable local interrupts while processing
 *
 *	IRQF_SAMPLE_RANDOM	The interrupt can be used for entropy
 *
 */

int request_irq(unsigned int irq,
		irqreturn_t (*handler)(int, void *, struct pt_regs *),
		unsigned long irqflags,
		const char * devname,
		void *dev_id)
{
	int retval;
	struct irqaction *action;

#if 1
	/*
	 * Sanity-check: shared interrupts should REALLY pass in
	 * a real dev-ID, otherwise we'll have trouble later trying
	 * to figure out which interrupt is which (messes up the
	 * interrupt freeing logic etc).
	 */
	if (irqflags & IRQF_SHARED) {
		if (!dev_id)
			printk("Bad boy: %s (at 0x%x) called us without a dev_id!\n",
			       devname, (&irq)[-1]);
	}
#endif

	if ((irq >> NR_IRQ_LOG2_ACTIONS_PER_GROUP) >= NR_IRQ_GROUPS)
		return -EINVAL;
	if (!handler)
		return -EINVAL;

	action = (struct irqaction *) kmalloc(sizeof(struct irqaction), GFP_KERNEL);
	if (!action)
		return -ENOMEM;

	action->handler = handler;
	action->flags = irqflags;
	action->mask = CPU_MASK_NONE;
	action->name = devname;
	action->next = NULL;
	action->dev_id = dev_id;

	retval = setup_irq(irq, action);
	if (retval)
		kfree(action);
	return retval;
}

EXPORT_SYMBOL(request_irq);

/**
 *	free_irq - free an interrupt
 *	@irq: Interrupt line to free
 *	@dev_id: Device identity to free
 *
 *	Remove an interrupt handler. The handler is removed and if the
 *	interrupt line is no longer in use by any driver it is disabled.
 *	On a shared IRQ the caller must ensure the interrupt is disabled
 *	on the card it drives before calling this function. The function
 *	does not return until any executing interrupts for this IRQ
 *	have completed.
 *
 *	This function may be called from interrupt context.
 *
 *	Bugs: Attempting to free an irq in a handler for the same irq hangs
 *	      the machine.
 */

void free_irq(unsigned int irq, void *dev_id)
{
	struct irq_source *source;
	struct irq_group *group;
	struct irq_level *level;
	struct irqaction **p, **pp;
	unsigned long flags;

	if ((irq >> NR_IRQ_LOG2_ACTIONS_PER_GROUP) >= NR_IRQ_GROUPS)
		return;

	group = irq_groups[irq >> NR_IRQ_LOG2_ACTIONS_PER_GROUP];
	if (!group)
		BUG();

	source = group->sources[irq & (NR_IRQ_ACTIONS_PER_GROUP - 1)];
	if (!source)
		BUG();

	level = source->level;
	p = &group->actions[irq & (NR_IRQ_ACTIONS_PER_GROUP - 1)];

	spin_lock_irqsave(&level->lock, flags);

	for (pp = p; *pp; pp = &(*pp)->next) {
		struct irqaction *action = *pp;

		if (action->dev_id != dev_id)
			continue;

		/* found it - remove from the list of entries */
		*pp = action->next;

		level->usage--;

		if (p == pp && group->control)
			group->control(group, irq & (NR_IRQ_ACTIONS_PER_GROUP - 1), 0);

		if (level->usage == 0)
			__set_MASK(level - frv_irq_levels);

		spin_unlock_irqrestore(&level->lock,flags);

#ifdef CONFIG_SMP
		/* Wait to make sure it's not being used on another CPU */
		while (desc->status & IRQ_INPROGRESS)
			barrier();
#endif
		kfree(action);
		return;
	}
}

EXPORT_SYMBOL(free_irq);

/*
 * IRQ autodetection code..
 *
 * This depends on the fact that any interrupt that comes in on to an
 * unassigned IRQ will cause GxICR_DETECT to be set
 */

static DECLARE_MUTEX(probe_sem);

/**
 *	probe_irq_on	- begin an interrupt autodetect
 *
 *	Commence probing for an interrupt. The interrupts are scanned
 *	and a mask of potential interrupt lines is returned.
 *
 */

unsigned long probe_irq_on(void)
{
	down(&probe_sem);
	return 0;
}

EXPORT_SYMBOL(probe_irq_on);

/*
 * Return a mask of triggered interrupts (this
 * can handle only legacy ISA interrupts).
 */

/**
 *	probe_irq_mask - scan a bitmap of interrupt lines
 *	@val:	mask of interrupts to consider
 *
 *	Scan the ISA bus interrupt lines and return a bitmap of
 *	active interrupts. The interrupt probe logic state is then
 *	returned to its previous value.
 *
 *	Note: we need to scan all the irq's even though we will
 *	only return ISA irq numbers - just so that we reset them
 *	all to a known state.
 */
unsigned int probe_irq_mask(unsigned long xmask)
{
	up(&probe_sem);
	return 0;
}

EXPORT_SYMBOL(probe_irq_mask);

/*
 * Return the one interrupt that triggered (this can
 * handle any interrupt source).
 */

/**
 *	probe_irq_off	- end an interrupt autodetect
 *	@xmask: mask of potential interrupts (unused)
 *
 *	Scans the unused interrupt lines and returns the line which
 *	appears to have triggered the interrupt. If no interrupt was
 *	found then zero is returned. If more than one interrupt is
 *	found then minus the first candidate is returned to indicate
 *	their is doubt.
 *
 *	The interrupt probe logic state is returned to its previous
 *	value.
 *
 *	BUGS: When used in a module (which arguably shouldnt happen)
 *	nothing prevents two IRQ probe callers from overlapping. The
 *	results of this are non-optimal.
 */

int probe_irq_off(unsigned long xmask)
{
	up(&probe_sem);
	return -1;
}

EXPORT_SYMBOL(probe_irq_off);

/* this was setup_x86_irq but it seems pretty generic */
int setup_irq(unsigned int irq, struct irqaction *new)
{
	struct irq_source *source;
	struct irq_group *group;
	struct irq_level *level;
	struct irqaction **p, **pp;
	unsigned long flags;

	group = irq_groups[irq >> NR_IRQ_LOG2_ACTIONS_PER_GROUP];
	if (!group)
		BUG();

	source = group->sources[irq & (NR_IRQ_ACTIONS_PER_GROUP - 1)];
	if (!source)
		BUG();

	level = source->level;

	p = &group->actions[irq & (NR_IRQ_ACTIONS_PER_GROUP - 1)];

	/*
	 * Some drivers like serial.c use request_irq() heavily,
	 * so we have to be careful not to interfere with a
	 * running system.
	 */
	if (new->flags & IRQF_SAMPLE_RANDOM) {
		/*
		 * This function might sleep, we want to call it first,
		 * outside of the atomic block.
		 * Yes, this might clear the entropy pool if the wrong
		 * driver is attempted to be loaded, without actually
		 * installing a new handler, but is this really a problem,
		 * only the sysadmin is able to do this.
		 */
		rand_initialize_irq(irq);
	}

	/* must juggle the interrupt processing stuff with interrupts disabled */
	spin_lock_irqsave(&level->lock, flags);

	/* can't share interrupts unless all parties agree to */
	if (level->usage != 0 && !(level->flags & new->flags & IRQF_SHARED)) {
		spin_unlock_irqrestore(&level->lock,flags);
		return -EBUSY;
	}

	/* add new interrupt at end of irq queue */
	pp = p;
	while (*pp)
		pp = &(*pp)->next;

	*pp = new;

	level->usage++;
	level->flags = new->flags;

	/* turn the interrupts on */
	if (level->usage == 1)
		__clr_MASK(level - frv_irq_levels);

	if (p == pp && group->control)
		group->control(group, irq & (NR_IRQ_ACTIONS_PER_GROUP - 1), 1);

	spin_unlock_irqrestore(&level->lock, flags);
	register_irq_proc(irq);
	return 0;
}

static struct proc_dir_entry * root_irq_dir;
static struct proc_dir_entry * irq_dir [NR_IRQS];

#define HEX_DIGITS 8

static unsigned int parse_hex_value (const char __user *buffer,
				     unsigned long count, unsigned long *ret)
{
	unsigned char hexnum [HEX_DIGITS];
	unsigned long value;
	int i;

	if (!count)
		return -EINVAL;
	if (count > HEX_DIGITS)
		count = HEX_DIGITS;
	if (copy_from_user(hexnum, buffer, count))
		return -EFAULT;

	/*
	 * Parse the first 8 characters as a hex string, any non-hex char
	 * is end-of-string. '00e1', 'e1', '00E1', 'E1' are all the same.
	 */
	value = 0;

	for (i = 0; i < count; i++) {
		unsigned int c = hexnum[i];

		switch (c) {
			case '0' ... '9': c -= '0'; break;
			case 'a' ... 'f': c -= 'a'-10; break;
			case 'A' ... 'F': c -= 'A'-10; break;
		default:
			goto out;
		}
		value = (value << 4) | c;
	}
out:
	*ret = value;
	return 0;
}


static int prof_cpu_mask_read_proc (char *page, char **start, off_t off,
			int count, int *eof, void *data)
{
	unsigned long *mask = (unsigned long *) data;
	if (count < HEX_DIGITS+1)
		return -EINVAL;
	return sprintf (page, "%08lx\n", *mask);
}

static int prof_cpu_mask_write_proc (struct file *file, const char __user *buffer,
					unsigned long count, void *data)
{
	unsigned long *mask = (unsigned long *) data, full_count = count, err;
	unsigned long new_value;

	show_state();
	err = parse_hex_value(buffer, count, &new_value);
	if (err)
		return err;

	*mask = new_value;
	return full_count;
}

#define MAX_NAMELEN 10

static void register_irq_proc (unsigned int irq)
{
	char name [MAX_NAMELEN];

	if (!root_irq_dir || irq_dir[irq])
		return;

	memset(name, 0, MAX_NAMELEN);
	sprintf(name, "%d", irq);

	/* create /proc/irq/1234 */
	irq_dir[irq] = proc_mkdir(name, root_irq_dir);
}

unsigned long prof_cpu_mask = -1;

void init_irq_proc (void)
{
	struct proc_dir_entry *entry;
	int i;

	/* create /proc/irq */
	root_irq_dir = proc_mkdir("irq", NULL);

	/* create /proc/irq/prof_cpu_mask */
	entry = create_proc_entry("prof_cpu_mask", 0600, root_irq_dir);
	if (!entry)
	    return;

	entry->nlink = 1;
	entry->data = (void *)&prof_cpu_mask;
	entry->read_proc = prof_cpu_mask_read_proc;
	entry->write_proc = prof_cpu_mask_write_proc;

	/*
	 * Create entries for all existing IRQs.
	 */
	for (i = 0; i < NR_IRQS; i++)
		register_irq_proc(i);
}

/*****************************************************************************/
/*
 * initialise the interrupt system
 */
void __init init_IRQ(void)
{
	route_cpu_irqs();
	fpga_init();
#ifdef CONFIG_FUJITSU_MB93493
	route_mb93493_irqs();
#endif
} /* end init_IRQ() */