1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * ip22-int.c: Routines for generic manipulation of the INT[23] ASIC
4 * found on INDY and Indigo2 workstations.
5 *
6 * Copyright (C) 1996 David S. Miller (davem@davemloft.net)
7 * Copyright (C) 1997, 1998 Ralf Baechle (ralf@gnu.org)
8 * Copyright (C) 1999 Andrew R. Baker (andrewb@uab.edu)
9 * - Indigo2 changes
10 * - Interrupt handling fixes
11 * Copyright (C) 2001, 2003 Ladislav Michl (ladis@linux-mips.org)
12 */
13 #include <linux/types.h>
14 #include <linux/init.h>
15 #include <linux/kernel_stat.h>
16 #include <linux/interrupt.h>
17 #include <linux/ftrace.h>
18
19 #include <asm/irq_cpu.h>
20 #include <asm/sgi/hpc3.h>
21 #include <asm/sgi/ip22.h>
22
23 /* So far nothing hangs here */
24 #undef USE_LIO3_IRQ
25
26 struct sgint_regs *sgint;
27
28 static char lc0msk_to_irqnr[256];
29 static char lc1msk_to_irqnr[256];
30 static char lc2msk_to_irqnr[256];
31 static char lc3msk_to_irqnr[256];
32
33 extern int ip22_eisa_init(void);
34
enable_local0_irq(struct irq_data * d)35 static void enable_local0_irq(struct irq_data *d)
36 {
37 /* don't allow mappable interrupt to be enabled from setup_irq,
38 * we have our own way to do so */
39 if (d->irq != SGI_MAP_0_IRQ)
40 sgint->imask0 |= (1 << (d->irq - SGINT_LOCAL0));
41 }
42
disable_local0_irq(struct irq_data * d)43 static void disable_local0_irq(struct irq_data *d)
44 {
45 sgint->imask0 &= ~(1 << (d->irq - SGINT_LOCAL0));
46 }
47
48 static struct irq_chip ip22_local0_irq_type = {
49 .name = "IP22 local 0",
50 .irq_mask = disable_local0_irq,
51 .irq_unmask = enable_local0_irq,
52 };
53
enable_local1_irq(struct irq_data * d)54 static void enable_local1_irq(struct irq_data *d)
55 {
56 /* don't allow mappable interrupt to be enabled from setup_irq,
57 * we have our own way to do so */
58 if (d->irq != SGI_MAP_1_IRQ)
59 sgint->imask1 |= (1 << (d->irq - SGINT_LOCAL1));
60 }
61
disable_local1_irq(struct irq_data * d)62 static void disable_local1_irq(struct irq_data *d)
63 {
64 sgint->imask1 &= ~(1 << (d->irq - SGINT_LOCAL1));
65 }
66
67 static struct irq_chip ip22_local1_irq_type = {
68 .name = "IP22 local 1",
69 .irq_mask = disable_local1_irq,
70 .irq_unmask = enable_local1_irq,
71 };
72
enable_local2_irq(struct irq_data * d)73 static void enable_local2_irq(struct irq_data *d)
74 {
75 sgint->imask0 |= (1 << (SGI_MAP_0_IRQ - SGINT_LOCAL0));
76 sgint->cmeimask0 |= (1 << (d->irq - SGINT_LOCAL2));
77 }
78
disable_local2_irq(struct irq_data * d)79 static void disable_local2_irq(struct irq_data *d)
80 {
81 sgint->cmeimask0 &= ~(1 << (d->irq - SGINT_LOCAL2));
82 if (!sgint->cmeimask0)
83 sgint->imask0 &= ~(1 << (SGI_MAP_0_IRQ - SGINT_LOCAL0));
84 }
85
86 static struct irq_chip ip22_local2_irq_type = {
87 .name = "IP22 local 2",
88 .irq_mask = disable_local2_irq,
89 .irq_unmask = enable_local2_irq,
90 };
91
enable_local3_irq(struct irq_data * d)92 static void enable_local3_irq(struct irq_data *d)
93 {
94 sgint->imask1 |= (1 << (SGI_MAP_1_IRQ - SGINT_LOCAL1));
95 sgint->cmeimask1 |= (1 << (d->irq - SGINT_LOCAL3));
96 }
97
disable_local3_irq(struct irq_data * d)98 static void disable_local3_irq(struct irq_data *d)
99 {
100 sgint->cmeimask1 &= ~(1 << (d->irq - SGINT_LOCAL3));
101 if (!sgint->cmeimask1)
102 sgint->imask1 &= ~(1 << (SGI_MAP_1_IRQ - SGINT_LOCAL1));
103 }
104
105 static struct irq_chip ip22_local3_irq_type = {
106 .name = "IP22 local 3",
107 .irq_mask = disable_local3_irq,
108 .irq_unmask = enable_local3_irq,
109 };
110
indy_local0_irqdispatch(void)111 static void indy_local0_irqdispatch(void)
112 {
113 u8 mask = sgint->istat0 & sgint->imask0;
114 u8 mask2;
115 int irq;
116
117 if (mask & SGINT_ISTAT0_LIO2) {
118 mask2 = sgint->vmeistat & sgint->cmeimask0;
119 irq = lc2msk_to_irqnr[mask2];
120 } else
121 irq = lc0msk_to_irqnr[mask];
122
123 /*
124 * workaround for INT2 bug; if irq == 0, INT2 has seen a fifo full
125 * irq, but failed to latch it into status register
126 */
127 if (irq)
128 do_IRQ(irq);
129 else
130 do_IRQ(SGINT_LOCAL0 + 0);
131 }
132
indy_local1_irqdispatch(void)133 static void indy_local1_irqdispatch(void)
134 {
135 u8 mask = sgint->istat1 & sgint->imask1;
136 u8 mask2;
137 int irq;
138
139 if (mask & SGINT_ISTAT1_LIO3) {
140 mask2 = sgint->vmeistat & sgint->cmeimask1;
141 irq = lc3msk_to_irqnr[mask2];
142 } else
143 irq = lc1msk_to_irqnr[mask];
144
145 /* if irq == 0, then the interrupt has already been cleared */
146 if (irq)
147 do_IRQ(irq);
148 }
149
150 extern void ip22_be_interrupt(int irq);
151
indy_buserror_irq(void)152 static void __irq_entry indy_buserror_irq(void)
153 {
154 int irq = SGI_BUSERR_IRQ;
155
156 irq_enter();
157 kstat_incr_irq_this_cpu(irq);
158 ip22_be_interrupt(irq);
159 irq_exit();
160 }
161
162 static struct irqaction local0_cascade = {
163 .handler = no_action,
164 .flags = IRQF_NO_THREAD,
165 .name = "local0 cascade",
166 };
167
168 static struct irqaction local1_cascade = {
169 .handler = no_action,
170 .flags = IRQF_NO_THREAD,
171 .name = "local1 cascade",
172 };
173
174 static struct irqaction buserr = {
175 .handler = no_action,
176 .flags = IRQF_NO_THREAD,
177 .name = "Bus Error",
178 };
179
180 static struct irqaction map0_cascade = {
181 .handler = no_action,
182 .flags = IRQF_NO_THREAD,
183 .name = "mapable0 cascade",
184 };
185
186 #ifdef USE_LIO3_IRQ
187 static struct irqaction map1_cascade = {
188 .handler = no_action,
189 .flags = IRQF_NO_THREAD,
190 .name = "mapable1 cascade",
191 };
192 #define SGI_INTERRUPTS SGINT_END
193 #else
194 #define SGI_INTERRUPTS SGINT_LOCAL3
195 #endif
196
197 extern void indy_8254timer_irq(void);
198
199 /*
200 * IRQs on the INDY look basically (barring software IRQs which we don't use
201 * at all) like:
202 *
203 * MIPS IRQ Source
204 * -------- ------
205 * 0 Software (ignored)
206 * 1 Software (ignored)
207 * 2 Local IRQ level zero
208 * 3 Local IRQ level one
209 * 4 8254 Timer zero
210 * 5 8254 Timer one
211 * 6 Bus Error
212 * 7 R4k timer (what we use)
213 *
214 * We handle the IRQ according to _our_ priority which is:
215 *
216 * Highest ---- R4k Timer
217 * Local IRQ zero
218 * Local IRQ one
219 * Bus Error
220 * 8254 Timer zero
221 * Lowest ---- 8254 Timer one
222 *
223 * then we just return, if multiple IRQs are pending then we will just take
224 * another exception, big deal.
225 */
226
plat_irq_dispatch(void)227 asmlinkage void plat_irq_dispatch(void)
228 {
229 unsigned int pending = read_c0_status() & read_c0_cause();
230
231 /*
232 * First we check for r4k counter/timer IRQ.
233 */
234 if (pending & CAUSEF_IP7)
235 do_IRQ(SGI_TIMER_IRQ);
236 else if (pending & CAUSEF_IP2)
237 indy_local0_irqdispatch();
238 else if (pending & CAUSEF_IP3)
239 indy_local1_irqdispatch();
240 else if (pending & CAUSEF_IP6)
241 indy_buserror_irq();
242 else if (pending & (CAUSEF_IP4 | CAUSEF_IP5))
243 indy_8254timer_irq();
244 }
245
arch_init_irq(void)246 void __init arch_init_irq(void)
247 {
248 int i;
249
250 /* Init local mask --> irq tables. */
251 for (i = 0; i < 256; i++) {
252 if (i & 0x80) {
253 lc0msk_to_irqnr[i] = SGINT_LOCAL0 + 7;
254 lc1msk_to_irqnr[i] = SGINT_LOCAL1 + 7;
255 lc2msk_to_irqnr[i] = SGINT_LOCAL2 + 7;
256 lc3msk_to_irqnr[i] = SGINT_LOCAL3 + 7;
257 } else if (i & 0x40) {
258 lc0msk_to_irqnr[i] = SGINT_LOCAL0 + 6;
259 lc1msk_to_irqnr[i] = SGINT_LOCAL1 + 6;
260 lc2msk_to_irqnr[i] = SGINT_LOCAL2 + 6;
261 lc3msk_to_irqnr[i] = SGINT_LOCAL3 + 6;
262 } else if (i & 0x20) {
263 lc0msk_to_irqnr[i] = SGINT_LOCAL0 + 5;
264 lc1msk_to_irqnr[i] = SGINT_LOCAL1 + 5;
265 lc2msk_to_irqnr[i] = SGINT_LOCAL2 + 5;
266 lc3msk_to_irqnr[i] = SGINT_LOCAL3 + 5;
267 } else if (i & 0x10) {
268 lc0msk_to_irqnr[i] = SGINT_LOCAL0 + 4;
269 lc1msk_to_irqnr[i] = SGINT_LOCAL1 + 4;
270 lc2msk_to_irqnr[i] = SGINT_LOCAL2 + 4;
271 lc3msk_to_irqnr[i] = SGINT_LOCAL3 + 4;
272 } else if (i & 0x08) {
273 lc0msk_to_irqnr[i] = SGINT_LOCAL0 + 3;
274 lc1msk_to_irqnr[i] = SGINT_LOCAL1 + 3;
275 lc2msk_to_irqnr[i] = SGINT_LOCAL2 + 3;
276 lc3msk_to_irqnr[i] = SGINT_LOCAL3 + 3;
277 } else if (i & 0x04) {
278 lc0msk_to_irqnr[i] = SGINT_LOCAL0 + 2;
279 lc1msk_to_irqnr[i] = SGINT_LOCAL1 + 2;
280 lc2msk_to_irqnr[i] = SGINT_LOCAL2 + 2;
281 lc3msk_to_irqnr[i] = SGINT_LOCAL3 + 2;
282 } else if (i & 0x02) {
283 lc0msk_to_irqnr[i] = SGINT_LOCAL0 + 1;
284 lc1msk_to_irqnr[i] = SGINT_LOCAL1 + 1;
285 lc2msk_to_irqnr[i] = SGINT_LOCAL2 + 1;
286 lc3msk_to_irqnr[i] = SGINT_LOCAL3 + 1;
287 } else if (i & 0x01) {
288 lc0msk_to_irqnr[i] = SGINT_LOCAL0 + 0;
289 lc1msk_to_irqnr[i] = SGINT_LOCAL1 + 0;
290 lc2msk_to_irqnr[i] = SGINT_LOCAL2 + 0;
291 lc3msk_to_irqnr[i] = SGINT_LOCAL3 + 0;
292 } else {
293 lc0msk_to_irqnr[i] = 0;
294 lc1msk_to_irqnr[i] = 0;
295 lc2msk_to_irqnr[i] = 0;
296 lc3msk_to_irqnr[i] = 0;
297 }
298 }
299
300 /* Mask out all interrupts. */
301 sgint->imask0 = 0;
302 sgint->imask1 = 0;
303 sgint->cmeimask0 = 0;
304 sgint->cmeimask1 = 0;
305
306 /* init CPU irqs */
307 mips_cpu_irq_init();
308
309 for (i = SGINT_LOCAL0; i < SGI_INTERRUPTS; i++) {
310 struct irq_chip *handler;
311
312 if (i < SGINT_LOCAL1)
313 handler = &ip22_local0_irq_type;
314 else if (i < SGINT_LOCAL2)
315 handler = &ip22_local1_irq_type;
316 else if (i < SGINT_LOCAL3)
317 handler = &ip22_local2_irq_type;
318 else
319 handler = &ip22_local3_irq_type;
320
321 irq_set_chip_and_handler(i, handler, handle_level_irq);
322 }
323
324 /* vector handler. this register the IRQ as non-sharable */
325 setup_irq(SGI_LOCAL_0_IRQ, &local0_cascade);
326 setup_irq(SGI_LOCAL_1_IRQ, &local1_cascade);
327 setup_irq(SGI_BUSERR_IRQ, &buserr);
328
329 /* cascade in cascade. i love Indy ;-) */
330 setup_irq(SGI_MAP_0_IRQ, &map0_cascade);
331 #ifdef USE_LIO3_IRQ
332 setup_irq(SGI_MAP_1_IRQ, &map1_cascade);
333 #endif
334
335 #ifdef CONFIG_EISA
336 if (ip22_is_fullhouse()) /* Only Indigo-2 has EISA stuff */
337 ip22_eisa_init();
338 #endif
339 }
340