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 #ifdef USE_LIO3_IRQ
163 #define SGI_INTERRUPTS SGINT_END
164 #else
165 #define SGI_INTERRUPTS SGINT_LOCAL3
166 #endif
167
168 extern void indy_8254timer_irq(void);
169
170 /*
171 * IRQs on the INDY look basically (barring software IRQs which we don't use
172 * at all) like:
173 *
174 * MIPS IRQ Source
175 * -------- ------
176 * 0 Software (ignored)
177 * 1 Software (ignored)
178 * 2 Local IRQ level zero
179 * 3 Local IRQ level one
180 * 4 8254 Timer zero
181 * 5 8254 Timer one
182 * 6 Bus Error
183 * 7 R4k timer (what we use)
184 *
185 * We handle the IRQ according to _our_ priority which is:
186 *
187 * Highest ---- R4k Timer
188 * Local IRQ zero
189 * Local IRQ one
190 * Bus Error
191 * 8254 Timer zero
192 * Lowest ---- 8254 Timer one
193 *
194 * then we just return, if multiple IRQs are pending then we will just take
195 * another exception, big deal.
196 */
197
plat_irq_dispatch(void)198 asmlinkage void plat_irq_dispatch(void)
199 {
200 unsigned int pending = read_c0_status() & read_c0_cause();
201
202 /*
203 * First we check for r4k counter/timer IRQ.
204 */
205 if (pending & CAUSEF_IP7)
206 do_IRQ(SGI_TIMER_IRQ);
207 else if (pending & CAUSEF_IP2)
208 indy_local0_irqdispatch();
209 else if (pending & CAUSEF_IP3)
210 indy_local1_irqdispatch();
211 else if (pending & CAUSEF_IP6)
212 indy_buserror_irq();
213 else if (pending & (CAUSEF_IP4 | CAUSEF_IP5))
214 indy_8254timer_irq();
215 }
216
arch_init_irq(void)217 void __init arch_init_irq(void)
218 {
219 int i;
220
221 /* Init local mask --> irq tables. */
222 for (i = 0; i < 256; i++) {
223 if (i & 0x80) {
224 lc0msk_to_irqnr[i] = SGINT_LOCAL0 + 7;
225 lc1msk_to_irqnr[i] = SGINT_LOCAL1 + 7;
226 lc2msk_to_irqnr[i] = SGINT_LOCAL2 + 7;
227 lc3msk_to_irqnr[i] = SGINT_LOCAL3 + 7;
228 } else if (i & 0x40) {
229 lc0msk_to_irqnr[i] = SGINT_LOCAL0 + 6;
230 lc1msk_to_irqnr[i] = SGINT_LOCAL1 + 6;
231 lc2msk_to_irqnr[i] = SGINT_LOCAL2 + 6;
232 lc3msk_to_irqnr[i] = SGINT_LOCAL3 + 6;
233 } else if (i & 0x20) {
234 lc0msk_to_irqnr[i] = SGINT_LOCAL0 + 5;
235 lc1msk_to_irqnr[i] = SGINT_LOCAL1 + 5;
236 lc2msk_to_irqnr[i] = SGINT_LOCAL2 + 5;
237 lc3msk_to_irqnr[i] = SGINT_LOCAL3 + 5;
238 } else if (i & 0x10) {
239 lc0msk_to_irqnr[i] = SGINT_LOCAL0 + 4;
240 lc1msk_to_irqnr[i] = SGINT_LOCAL1 + 4;
241 lc2msk_to_irqnr[i] = SGINT_LOCAL2 + 4;
242 lc3msk_to_irqnr[i] = SGINT_LOCAL3 + 4;
243 } else if (i & 0x08) {
244 lc0msk_to_irqnr[i] = SGINT_LOCAL0 + 3;
245 lc1msk_to_irqnr[i] = SGINT_LOCAL1 + 3;
246 lc2msk_to_irqnr[i] = SGINT_LOCAL2 + 3;
247 lc3msk_to_irqnr[i] = SGINT_LOCAL3 + 3;
248 } else if (i & 0x04) {
249 lc0msk_to_irqnr[i] = SGINT_LOCAL0 + 2;
250 lc1msk_to_irqnr[i] = SGINT_LOCAL1 + 2;
251 lc2msk_to_irqnr[i] = SGINT_LOCAL2 + 2;
252 lc3msk_to_irqnr[i] = SGINT_LOCAL3 + 2;
253 } else if (i & 0x02) {
254 lc0msk_to_irqnr[i] = SGINT_LOCAL0 + 1;
255 lc1msk_to_irqnr[i] = SGINT_LOCAL1 + 1;
256 lc2msk_to_irqnr[i] = SGINT_LOCAL2 + 1;
257 lc3msk_to_irqnr[i] = SGINT_LOCAL3 + 1;
258 } else if (i & 0x01) {
259 lc0msk_to_irqnr[i] = SGINT_LOCAL0 + 0;
260 lc1msk_to_irqnr[i] = SGINT_LOCAL1 + 0;
261 lc2msk_to_irqnr[i] = SGINT_LOCAL2 + 0;
262 lc3msk_to_irqnr[i] = SGINT_LOCAL3 + 0;
263 } else {
264 lc0msk_to_irqnr[i] = 0;
265 lc1msk_to_irqnr[i] = 0;
266 lc2msk_to_irqnr[i] = 0;
267 lc3msk_to_irqnr[i] = 0;
268 }
269 }
270
271 /* Mask out all interrupts. */
272 sgint->imask0 = 0;
273 sgint->imask1 = 0;
274 sgint->cmeimask0 = 0;
275 sgint->cmeimask1 = 0;
276
277 /* init CPU irqs */
278 mips_cpu_irq_init();
279
280 for (i = SGINT_LOCAL0; i < SGI_INTERRUPTS; i++) {
281 struct irq_chip *handler;
282
283 if (i < SGINT_LOCAL1)
284 handler = &ip22_local0_irq_type;
285 else if (i < SGINT_LOCAL2)
286 handler = &ip22_local1_irq_type;
287 else if (i < SGINT_LOCAL3)
288 handler = &ip22_local2_irq_type;
289 else
290 handler = &ip22_local3_irq_type;
291
292 irq_set_chip_and_handler(i, handler, handle_level_irq);
293 }
294
295 /* vector handler. this register the IRQ as non-sharable */
296 if (request_irq(SGI_LOCAL_0_IRQ, no_action, IRQF_NO_THREAD,
297 "local0 cascade", NULL))
298 pr_err("Failed to register local0 cascade interrupt\n");
299 if (request_irq(SGI_LOCAL_1_IRQ, no_action, IRQF_NO_THREAD,
300 "local1 cascade", NULL))
301 pr_err("Failed to register local1 cascade interrupt\n");
302 if (request_irq(SGI_BUSERR_IRQ, no_action, IRQF_NO_THREAD,
303 "Bus Error", NULL))
304 pr_err("Failed to register Bus Error interrupt\n");
305
306 /* cascade in cascade. i love Indy ;-) */
307 if (request_irq(SGI_MAP_0_IRQ, no_action, IRQF_NO_THREAD,
308 "mapable0 cascade", NULL))
309 pr_err("Failed to register mapable0 cascade interrupt\n");
310 #ifdef USE_LIO3_IRQ
311 if (request_irq(SGI_MAP_1_IRQ, no_action, IRQF_NO_THREAD,
312 "mapable1 cascade", NULL))
313 pr_err("Failed to register mapable1 cascade interrupt\n");
314 #endif
315
316 #ifdef CONFIG_EISA
317 if (ip22_is_fullhouse()) /* Only Indigo-2 has EISA stuff */
318 ip22_eisa_init();
319 #endif
320 }
321