summaryrefslogtreecommitdiffstats
path: root/arch/mips/kernel/old-irq.c
blob: a5dfa25429160ba052488617fc8af9d300fd2a4d (plain)
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
/*
 * This file is subject to the terms and conditions of the GNU General Public
 * License.  See the file "COPYING" in the main directory of this archive
 * for more details.
 *
 * Code to handle x86 style IRQs plus some generic interrupt stuff.
 *
 * Copyright (C) 1992 Linus Torvalds
 * Copyright (C) 1994 - 2001 Ralf Baechle
 *
 * Old rotten IRQ code.  To be killed as soon as everybody had converted or
 * in 2.5.0, whatever comes first.
 */
#include <linux/config.h>
#include <linux/errno.h>
#include <linux/init.h>
#include <linux/kernel_stat.h>
#include <linux/module.h>
#include <linux/signal.h>
#include <linux/sched.h>
#include <linux/types.h>
#include <linux/interrupt.h>
#include <linux/ioport.h>
#include <linux/timex.h>
#include <linux/slab.h>
#include <linux/random.h>

#include <asm/bitops.h>
#include <asm/bootinfo.h>
#include <asm/io.h>
#include <asm/irq.h>
#include <asm/mipsregs.h>
#include <asm/system.h>
#include <asm/nile4.h>

/*
 * The board specific setup routine sets irq_setup to point to a board
 * specific setup routine.
 */
void (*irq_setup)(void);

/*
 * Linux has a controller-independent x86 interrupt architecture.
 * every controller has a 'controller-template', that is used
 * by the main code to do the right thing. Each driver-visible
 * interrupt source is transparently wired to the apropriate
 * controller. Thus drivers need not be aware of the
 * interrupt-controller.
 *
 * Various interrupt controllers we handle: 8259 PIC, SMP IO-APIC,
 * PIIX4's internal 8259 PIC and SGI's Visual Workstation Cobalt (IO-)APIC.
 * (IO-APICs assumed to be messaging to Pentium local-APICs)
 *
 * the code is designed to be easily extended with new/different
 * interrupt controllers, without having to do assembly magic.
 */

/*
 * This contains the irq mask for both 8259A irq controllers, it's an
 * int so we can deal with the third PIC in some systems like the RM300.
 * (XXX This is broken for big endian.)
 */
static unsigned int cached_irq_mask = 0xffff;

#define __byte(x,y) (((unsigned char *)&(y))[x])
#define __word(x,y) (((unsigned short *)&(y))[x])
#define __long(x,y) (((unsigned int *)&(y))[x])

#define cached_21       (__byte(0,cached_irq_mask))
#define cached_A1       (__byte(1,cached_irq_mask))

unsigned long spurious_count = 0;

/*
 * (un)mask_irq, disable_irq() and enable_irq() only handle (E)ISA and
 * PCI devices.  Other onboard hardware needs specific routines.
 */
static inline void mask_irq(unsigned int irq)
{
	cached_irq_mask |= 1 << irq;
	if (irq & 8) {
		outb(cached_A1, 0xa1);
	} else {
		outb(cached_21, 0x21);
	}
}

static inline void unmask_irq(unsigned int irq)
{
	cached_irq_mask &= ~(1 << irq);
	if (irq & 8) {
		outb(cached_A1, 0xa1);
	} else {
		outb(cached_21, 0x21);
	}
}

void i8259_disable_irq(unsigned int irq_nr)
{
	unsigned long flags;

	save_and_cli(flags);
	mask_irq(irq_nr);
	restore_flags(flags);
}

void i8259_enable_irq(unsigned int irq_nr)
{
	unsigned long flags;
	save_and_cli(flags);
	unmask_irq(irq_nr);
	restore_flags(flags);
}

static struct irqaction *irq_action[NR_IRQS] = {
	NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL,
	NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL,
	NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL,
	NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL,
	NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL,
	NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL,
	NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL,
	NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL
};

int get_irq_list(char *buf)
{
	int i, len = 0;
	struct irqaction * action;

	for (i = 0 ; i < 32 ; i++) {
		action = irq_action[i];
		if (!action) 
			continue;
		len += sprintf(buf+len, "%2d: %8d %c %s",
			i, kstat.irqs[0][i],
			(action->flags & SA_INTERRUPT) ? '+' : ' ',
			action->name);
		for (action=action->next; action; action = action->next) {
			len += sprintf(buf+len, ",%s %s",
				(action->flags & SA_INTERRUPT) ? " +" : "",
				action->name);
		}
		len += sprintf(buf+len, "\n");
	}
	return len;
}

static inline void i8259_mask_and_ack_irq(int irq)
{
	cached_irq_mask |= 1 << irq;

	if (irq & 8) {
		inb(0xa1);
		outb(cached_A1, 0xa1);
		outb(0x62, 0x20);		/* Specific EOI to cascade */
                outb(0x20, 0xa0);
        } else {
		inb(0x21);
		outb(cached_21, 0x21);
		outb(0x20, 0x20);
        }
}

asmlinkage void i8259_do_irq(int irq, struct pt_regs *regs)
{
	struct irqaction *action;
	int do_random, cpu;

	cpu = smp_processor_id();
	irq_enter(cpu, irq);

	if (irq >= 16)
		goto out;

	i8259_mask_and_ack_irq(irq);

	kstat.irqs[cpu][irq]++;

	action = *(irq + irq_action);
	if (!action)
		goto out;

	if (!(action->flags & SA_INTERRUPT))
		__sti();
	action = *(irq + irq_action);
	do_random = 0;
       	do {
		do_random |= action->flags;
		action->handler(irq, action->dev_id, regs);
		action = action->next;
       	} while (action);
	if (do_random & SA_SAMPLE_RANDOM)
		add_interrupt_randomness(irq);
	__cli();
	unmask_irq (irq);

out:
	irq_exit(cpu, irq);
}

/*
 * do_IRQ handles IRQ's that have been installed without the
 * SA_INTERRUPT flag: it uses the full signal-handling return
 * and runs with other interrupts enabled. All relatively slow
 * IRQ's should use this format: notably the keyboard/timer
 * routines.
 */
asmlinkage void do_IRQ(int irq, struct pt_regs * regs)
{
	struct irqaction *action;
	int do_random, cpu;

	cpu = smp_processor_id();
	irq_enter(cpu, irq);
	kstat.irqs[cpu][irq]++;

	action = *(irq + irq_action);
	if (action) {
		if (!(action->flags & SA_INTERRUPT))
			__sti();
		action = *(irq + irq_action);
		do_random = 0;
        	do {
			do_random |= action->flags;
			action->handler(irq, action->dev_id, regs);
			action = action->next;
        	} while (action);
		if (do_random & SA_SAMPLE_RANDOM)
			add_interrupt_randomness(irq);
		__cli();
	}
	irq_exit(cpu, irq);

	if (softirq_active(cpu)&softirq_mask(cpu))
		do_softirq();

	/* unmasking and bottom half handling is done magically for us. */
}

int i8259_setup_irq(int irq, struct irqaction * new)
{
	int shared = 0;
	struct irqaction *old, **p;
	unsigned long flags;

	p = irq_action + irq;
	if ((old = *p) != NULL) {
		/* Can't share interrupts unless both agree to */
		if (!(old->flags & new->flags & SA_SHIRQ))
			return -EBUSY;

		/* Can't share interrupts unless both are same type */
		if ((old->flags ^ new->flags) & SA_INTERRUPT)
			return -EBUSY;

		/* add new interrupt at end of irq queue */
		do {
			p = &old->next;
			old = *p;
		} while (old);
		shared = 1;
	}

	if (new->flags & SA_SAMPLE_RANDOM)
		rand_initialize_irq(irq);

	save_and_cli(flags);
	*p = new;

	if (!shared) {
		if (is_i8259_irq(irq))
		    unmask_irq(irq);
#if (defined(CONFIG_DDB5074) || defined(CONFIG_DDB5476))
		else
		    nile4_enable_irq(irq_to_nile4(irq));
#endif
	}
	restore_flags(flags);
	return 0;
}

/*
 * Request_interrupt and free_interrupt ``sort of'' handle interrupts of
 * non i8259 devices.  They will have to be replaced by architecture
 * specific variants.  For now we still use this as broken as it is because
 * it used to work ...
 */
int request_irq(unsigned int irq, 
		void (*handler)(int, void *, struct pt_regs *),
		unsigned long irqflags, const char * devname, void *dev_id)
{
	int retval;
	struct irqaction * action;

	if (irq >= 32)
		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 = 0;
	action->name = devname;
	action->next = NULL;
	action->dev_id = dev_id;

	retval = i8259_setup_irq(irq, action);

	if (retval)
		kfree(action);
	return retval;
}
		
void free_irq(unsigned int irq, void *dev_id)
{
	struct irqaction * action, **p;
	unsigned long flags;

	if (irq > 31) {
		printk("Trying to free IRQ%d\n",irq);
		return;
	}
	for (p = irq + irq_action; (action = *p) != NULL; p = &action->next) {
		if (action->dev_id != dev_id)
			continue;

		/* Found it - now free it */
		save_and_cli(flags);
		*p = action->next;
		if (!irq[irq_action])
			mask_irq(irq);
		restore_flags(flags);
		kfree(action);
		return;
	}
	printk("Trying to free free IRQ%d\n",irq);
}

unsigned long probe_irq_on (void)
{
	unsigned int i, irqs = 0;
	unsigned long delay;

	/* first, enable any unassigned (E)ISA irqs */
	for (i = 15; i > 0; i--) {
		if (!irq_action[i]) {
			i8259_enable_irq(i);
			irqs |= (1 << i);
		}
	}

	/* wait for spurious interrupts to mask themselves out again */
	for (delay = jiffies + HZ/10; time_before(jiffies, delay); )
		/* about 100ms delay */;

	/* now filter out any obviously spurious interrupts */
	return irqs & ~cached_irq_mask;
}

int probe_irq_off (unsigned long irqs)
{
	unsigned int i;

#ifdef DEBUG
	printk("probe_irq_off: irqs=0x%04x irqmask=0x%04x\n", irqs, irqmask);
#endif
	irqs &= cached_irq_mask;
	if (!irqs)
		return 0;
	i = ffz(~irqs);
	if (irqs != (irqs & (1 << i)))
		i = -i;
	return i;
}

void __init i8259_init(void)
{
	/* Init master interrupt controller */
	outb(0x11, 0x20); /* Start init sequence */
	outb(0x00, 0x21); /* Vector base */
	outb(0x04, 0x21); /* edge tiggered, Cascade (slave) on IRQ2 */
	outb(0x01, 0x21); /* Select 8086 mode */
	outb(0xff, 0x21); /* Mask all */
        
	/* Init slave interrupt controller */
	outb(0x11, 0xa0); /* Start init sequence */
	outb(0x08, 0xa1); /* Vector base */
	outb(0x02, 0xa1); /* edge triggered, Cascade (slave) on IRQ2 */
	outb(0x01, 0xa1); /* Select 8086 mode */
	outb(0xff, 0xa1); /* Mask all */

	outb(cached_A1, 0xa1);
	outb(cached_21, 0x21);
}

void __init init_IRQ(void)
{
	/* i8259_init(); */
	irq_setup();
}