aboutsummaryrefslogtreecommitdiff
path: root/arch/mips/sgi-ip22/ip22-int.c
blob: 3f2b7633f946a6bbe020d80f4643ad253789da82 (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
/*
 * ip22-int.c: Routines for generic manipulation of the INT[23] ASIC
 *             found on INDY and Indigo2 workstations.
 *
 * Copyright (C) 1996 David S. Miller (davem@davemloft.net)
 * Copyright (C) 1997, 1998 Ralf Baechle (ralf@gnu.org)
 * Copyright (C) 1999 Andrew R. Baker (andrewb@uab.edu)
 *                    - Indigo2 changes
 *                    - Interrupt handling fixes
 * Copyright (C) 2001, 2003 Ladislav Michl (ladis@linux-mips.org)
 */
#include <linux/types.h>
#include <linux/init.h>
#include <linux/kernel_stat.h>
#include <linux/interrupt.h>
#include <linux/ftrace.h>

#include <asm/irq_cpu.h>
#include <asm/sgi/hpc3.h>
#include <asm/sgi/ip22.h>

/* So far nothing hangs here */
#undef USE_LIO3_IRQ

struct sgint_regs *sgint;

static char lc0msk_to_irqnr[256];
static char lc1msk_to_irqnr[256];
static char lc2msk_to_irqnr[256];
static char lc3msk_to_irqnr[256];

extern int ip22_eisa_init(void);

static void enable_local0_irq(struct irq_data *d)
{
	/* don't allow mappable interrupt to be enabled from setup_irq,
	 * we have our own way to do so */
	if (d->irq != SGI_MAP_0_IRQ)
		sgint->imask0 |= (1 << (d->irq - SGINT_LOCAL0));
}

static void disable_local0_irq(struct irq_data *d)
{
	sgint->imask0 &= ~(1 << (d->irq - SGINT_LOCAL0));
}

static struct irq_chip ip22_local0_irq_type = {
	.name		= "IP22 local 0",
	.irq_mask	= disable_local0_irq,
	.irq_unmask	= enable_local0_irq,
};

static void enable_local1_irq(struct irq_data *d)
{
	/* don't allow mappable interrupt to be enabled from setup_irq,
	 * we have our own way to do so */
	if (d->irq != SGI_MAP_1_IRQ)
		sgint->imask1 |= (1 << (d->irq - SGINT_LOCAL1));
}

static void disable_local1_irq(struct irq_data *d)
{
	sgint->imask1 &= ~(1 << (d->irq - SGINT_LOCAL1));
}

static struct irq_chip ip22_local1_irq_type = {
	.name		= "IP22 local 1",
	.irq_mask	= disable_local1_irq,
	.irq_unmask	= enable_local1_irq,
};

static void enable_local2_irq(struct irq_data *d)
{
	sgint->imask0 |= (1 << (SGI_MAP_0_IRQ - SGINT_LOCAL0));
	sgint->cmeimask0 |= (1 << (d->irq - SGINT_LOCAL2));
}

static void disable_local2_irq(struct irq_data *d)
{
	sgint->cmeimask0 &= ~(1 << (d->irq - SGINT_LOCAL2));
	if (!sgint->cmeimask0)
		sgint->imask0 &= ~(1 << (SGI_MAP_0_IRQ - SGINT_LOCAL0));
}

static struct irq_chip ip22_local2_irq_type = {
	.name		= "IP22 local 2",
	.irq_mask	= disable_local2_irq,
	.irq_unmask	= enable_local2_irq,
};

static void enable_local3_irq(struct irq_data *d)
{
	sgint->imask1 |= (1 << (SGI_MAP_1_IRQ - SGINT_LOCAL1));
	sgint->cmeimask1 |= (1 << (d->irq - SGINT_LOCAL3));
}

static void disable_local3_irq(struct irq_data *d)
{
	sgint->cmeimask1 &= ~(1 << (d->irq - SGINT_LOCAL3));
	if (!sgint->cmeimask1)
		sgint->imask1 &= ~(1 << (SGI_MAP_1_IRQ - SGINT_LOCAL1));
}

static struct irq_chip ip22_local3_irq_type = {
	.name		= "IP22 local 3",
	.irq_mask	= disable_local3_irq,
	.irq_unmask	= enable_local3_irq,
};

static void indy_local0_irqdispatch(void)
{
	u8 mask = sgint->istat0 & sgint->imask0;
	u8 mask2;
	int irq;

	if (mask & SGINT_ISTAT0_LIO2) {
		mask2 = sgint->vmeistat & sgint->cmeimask0;
		irq = lc2msk_to_irqnr[mask2];
	} else
		irq = lc0msk_to_irqnr[mask];

	/* if irq == 0, then the interrupt has already been cleared */
	if (irq)
		do_IRQ(irq);
}

static void indy_local1_irqdispatch(void)
{
	u8 mask = sgint->istat1 & sgint->imask1;
	u8 mask2;
	int irq;

	if (mask & SGINT_ISTAT1_LIO3) {
		mask2 = sgint->vmeistat & sgint->cmeimask1;
		irq = lc3msk_to_irqnr[mask2];
	} else
		irq = lc1msk_to_irqnr[mask];

	/* if irq == 0, then the interrupt has already been cleared */
	if (irq)
		do_IRQ(irq);
}

extern void ip22_be_interrupt(int irq);

static void __irq_entry indy_buserror_irq(void)
{
	int irq = SGI_BUSERR_IRQ;

	irq_enter();
	kstat_incr_irqs_this_cpu(irq, irq_to_desc(irq));
	ip22_be_interrupt(irq);
	irq_exit();
}

static struct irqaction local0_cascade = {
	.handler	= no_action,
	.flags		= IRQF_NO_THREAD,
	.name		= "local0 cascade",
};

static struct irqaction local1_cascade = {
	.handler	= no_action,
	.flags		= IRQF_NO_THREAD,
	.name		= "local1 cascade",
};

static struct irqaction buserr = {
	.handler	= no_action,
	.flags		= IRQF_NO_THREAD,
	.name		= "Bus Error",
};

static struct irqaction map0_cascade = {
	.handler	= no_action,
	.flags		= IRQF_NO_THREAD,
	.name		= "mapable0 cascade",
};

#ifdef USE_LIO3_IRQ
static struct irqaction map1_cascade = {
	.handler	= no_action,
	.flags		= IRQF_NO_THREAD,
	.name		= "mapable1 cascade",
};
#define SGI_INTERRUPTS	SGINT_END
#else
#define SGI_INTERRUPTS	SGINT_LOCAL3
#endif

extern void indy_8254timer_irq(void);

/*
 * IRQs on the INDY look basically (barring software IRQs which we don't use
 * at all) like:
 *
 *	MIPS IRQ	Source
 *      --------        ------
 *             0	Software (ignored)
 *             1        Software (ignored)
 *             2        Local IRQ level zero
 *             3        Local IRQ level one
 *             4        8254 Timer zero
 *             5        8254 Timer one
 *             6        Bus Error
 *             7        R4k timer (what we use)
 *
 * We handle the IRQ according to _our_ priority which is:
 *
 * Highest ----     R4k Timer
 *                  Local IRQ zero
 *                  Local IRQ one
 *                  Bus Error
 *                  8254 Timer zero
 * Lowest  ----     8254 Timer one
 *
 * then we just return, if multiple IRQs are pending then we will just take
 * another exception, big deal.
 */

asmlinkage void plat_irq_dispatch(void)
{
	unsigned int pending = read_c0_status() & read_c0_cause();

	/*
	 * First we check for r4k counter/timer IRQ.
	 */
	if (pending & CAUSEF_IP7)
		do_IRQ(SGI_TIMER_IRQ);
	else if (pending & CAUSEF_IP2)
		indy_local0_irqdispatch();
	else if (pending & CAUSEF_IP3)
		indy_local1_irqdispatch();
	else if (pending & CAUSEF_IP6)
		indy_buserror_irq();
	else if (pending & (CAUSEF_IP4 | CAUSEF_IP5))
		indy_8254timer_irq();
}

void __init arch_init_irq(void)
{
	int i;

	/* Init local mask --> irq tables. */
	for (i = 0; i < 256; i++) {
		if (i & 0x80) {
			lc0msk_to_irqnr[i] = SGINT_LOCAL0 + 7;
			lc1msk_to_irqnr[i] = SGINT_LOCAL1 + 7;
			lc2msk_to_irqnr[i] = SGINT_LOCAL2 + 7;
			lc3msk_to_irqnr[i] = SGINT_LOCAL3 + 7;
		} else if (i & 0x40) {
			lc0msk_to_irqnr[i] = SGINT_LOCAL0 + 6;
			lc1msk_to_irqnr[i] = SGINT_LOCAL1 + 6;
			lc2msk_to_irqnr[i] = SGINT_LOCAL2 + 6;
			lc3msk_to_irqnr[i] = SGINT_LOCAL3 + 6;
		} else if (i & 0x20) {
			lc0msk_to_irqnr[i] = SGINT_LOCAL0 + 5;
			lc1msk_to_irqnr[i] = SGINT_LOCAL1 + 5;
			lc2msk_to_irqnr[i] = SGINT_LOCAL2 + 5;
			lc3msk_to_irqnr[i] = SGINT_LOCAL3 + 5;
		} else if (i & 0x10) {
			lc0msk_to_irqnr[i] = SGINT_LOCAL0 + 4;
			lc1msk_to_irqnr[i] = SGINT_LOCAL1 + 4;
			lc2msk_to_irqnr[i] = SGINT_LOCAL2 + 4;
			lc3msk_to_irqnr[i] = SGINT_LOCAL3 + 4;
		} else if (i & 0x08) {
			lc0msk_to_irqnr[i] = SGINT_LOCAL0 + 3;
			lc1msk_to_irqnr[i] = SGINT_LOCAL1 + 3;
			lc2msk_to_irqnr[i] = SGINT_LOCAL2 + 3;
			lc3msk_to_irqnr[i] = SGINT_LOCAL3 + 3;
		} else if (i & 0x04) {
			lc0msk_to_irqnr[i] = SGINT_LOCAL0 + 2;
			lc1msk_to_irqnr[i] = SGINT_LOCAL1 + 2;
			lc2msk_to_irqnr[i] = SGINT_LOCAL2 + 2;
			lc3msk_to_irqnr[i] = SGINT_LOCAL3 + 2;
		} else if (i & 0x02) {
			lc0msk_to_irqnr[i] = SGINT_LOCAL0 + 1;
			lc1msk_to_irqnr[i] = SGINT_LOCAL1 + 1;
			lc2msk_to_irqnr[i] = SGINT_LOCAL2 + 1;
			lc3msk_to_irqnr[i] = SGINT_LOCAL3 + 1;
		} else if (i & 0x01) {
			lc0msk_to_irqnr[i] = SGINT_LOCAL0 + 0;
			lc1msk_to_irqnr[i] = SGINT_LOCAL1 + 0;
			lc2msk_to_irqnr[i] = SGINT_LOCAL2 + 0;
			lc3msk_to_irqnr[i] = SGINT_LOCAL3 + 0;
		} else {
			lc0msk_to_irqnr[i] = 0;
			lc1msk_to_irqnr[i] = 0;
			lc2msk_to_irqnr[i] = 0;
			lc3msk_to_irqnr[i] = 0;
		}
	}

	/* Mask out all interrupts. */
	sgint->imask0 = 0;
	sgint->imask1 = 0;
	sgint->cmeimask0 = 0;
	sgint->cmeimask1 = 0;

	/* init CPU irqs */
	mips_cpu_irq_init();

	for (i = SGINT_LOCAL0; i < SGI_INTERRUPTS; i++) {
		struct irq_chip *handler;

		if (i < SGINT_LOCAL1)
			handler		= &ip22_local0_irq_type;
		else if (i < SGINT_LOCAL2)
			handler		= &ip22_local1_irq_type;
		else if (i < SGINT_LOCAL3)
			handler		= &ip22_local2_irq_type;
		else
			handler		= &ip22_local3_irq_type;

		irq_set_chip_and_handler(i, handler, handle_level_irq);
	}

	/* vector handler. this register the IRQ as non-sharable */
	setup_irq(SGI_LOCAL_0_IRQ, &local0_cascade);
	setup_irq(SGI_LOCAL_1_IRQ, &local1_cascade);
	setup_irq(SGI_BUSERR_IRQ, &buserr);

	/* cascade in cascade. i love Indy ;-) */
	setup_irq(SGI_MAP_0_IRQ, &map0_cascade);
#ifdef USE_LIO3_IRQ
	setup_irq(SGI_MAP_1_IRQ, &map1_cascade);
#endif

#ifdef CONFIG_EISA
	if (ip22_is_fullhouse())	/* Only Indigo-2 has EISA stuff */
		ip22_eisa_init();
#endif
}