xref: /openbmc/linux/arch/mips/bcm63xx/irq.c (revision 12eb4683)
1 /*
2  * This file is subject to the terms and conditions of the GNU General Public
3  * License.  See the file "COPYING" in the main directory of this archive
4  * for more details.
5  *
6  * Copyright (C) 2008 Maxime Bizon <mbizon@freebox.fr>
7  * Copyright (C) 2008 Nicolas Schichan <nschichan@freebox.fr>
8  */
9 
10 #include <linux/kernel.h>
11 #include <linux/init.h>
12 #include <linux/interrupt.h>
13 #include <linux/module.h>
14 #include <linux/irq.h>
15 #include <asm/irq_cpu.h>
16 #include <asm/mipsregs.h>
17 #include <bcm63xx_cpu.h>
18 #include <bcm63xx_regs.h>
19 #include <bcm63xx_io.h>
20 #include <bcm63xx_irq.h>
21 
22 static void __dispatch_internal(void) __maybe_unused;
23 static void __dispatch_internal_64(void) __maybe_unused;
24 static void __internal_irq_mask_32(unsigned int irq) __maybe_unused;
25 static void __internal_irq_mask_64(unsigned int irq) __maybe_unused;
26 static void __internal_irq_unmask_32(unsigned int irq) __maybe_unused;
27 static void __internal_irq_unmask_64(unsigned int irq) __maybe_unused;
28 
29 #ifndef BCMCPU_RUNTIME_DETECT
30 #ifdef CONFIG_BCM63XX_CPU_3368
31 #define irq_stat_reg		PERF_IRQSTAT_3368_REG
32 #define irq_mask_reg		PERF_IRQMASK_3368_REG
33 #define irq_bits		32
34 #define is_ext_irq_cascaded	0
35 #define ext_irq_start		0
36 #define ext_irq_end		0
37 #define ext_irq_count		4
38 #define ext_irq_cfg_reg1	PERF_EXTIRQ_CFG_REG_3368
39 #define ext_irq_cfg_reg2	0
40 #endif
41 #ifdef CONFIG_BCM63XX_CPU_6328
42 #define irq_stat_reg		PERF_IRQSTAT_6328_REG
43 #define irq_mask_reg		PERF_IRQMASK_6328_REG
44 #define irq_bits		64
45 #define is_ext_irq_cascaded	1
46 #define ext_irq_start		(BCM_6328_EXT_IRQ0 - IRQ_INTERNAL_BASE)
47 #define ext_irq_end		(BCM_6328_EXT_IRQ3 - IRQ_INTERNAL_BASE)
48 #define ext_irq_count		4
49 #define ext_irq_cfg_reg1	PERF_EXTIRQ_CFG_REG_6328
50 #define ext_irq_cfg_reg2	0
51 #endif
52 #ifdef CONFIG_BCM63XX_CPU_6338
53 #define irq_stat_reg		PERF_IRQSTAT_6338_REG
54 #define irq_mask_reg		PERF_IRQMASK_6338_REG
55 #define irq_bits		32
56 #define is_ext_irq_cascaded	0
57 #define ext_irq_start		0
58 #define ext_irq_end		0
59 #define ext_irq_count		4
60 #define ext_irq_cfg_reg1	PERF_EXTIRQ_CFG_REG_6338
61 #define ext_irq_cfg_reg2	0
62 #endif
63 #ifdef CONFIG_BCM63XX_CPU_6345
64 #define irq_stat_reg		PERF_IRQSTAT_6345_REG
65 #define irq_mask_reg		PERF_IRQMASK_6345_REG
66 #define irq_bits		32
67 #define is_ext_irq_cascaded	0
68 #define ext_irq_start		0
69 #define ext_irq_end		0
70 #define ext_irq_count		4
71 #define ext_irq_cfg_reg1	PERF_EXTIRQ_CFG_REG_6345
72 #define ext_irq_cfg_reg2	0
73 #endif
74 #ifdef CONFIG_BCM63XX_CPU_6348
75 #define irq_stat_reg		PERF_IRQSTAT_6348_REG
76 #define irq_mask_reg		PERF_IRQMASK_6348_REG
77 #define irq_bits		32
78 #define is_ext_irq_cascaded	0
79 #define ext_irq_start		0
80 #define ext_irq_end		0
81 #define ext_irq_count		4
82 #define ext_irq_cfg_reg1	PERF_EXTIRQ_CFG_REG_6348
83 #define ext_irq_cfg_reg2	0
84 #endif
85 #ifdef CONFIG_BCM63XX_CPU_6358
86 #define irq_stat_reg		PERF_IRQSTAT_6358_REG
87 #define irq_mask_reg		PERF_IRQMASK_6358_REG
88 #define irq_bits		32
89 #define is_ext_irq_cascaded	1
90 #define ext_irq_start		(BCM_6358_EXT_IRQ0 - IRQ_INTERNAL_BASE)
91 #define ext_irq_end		(BCM_6358_EXT_IRQ3 - IRQ_INTERNAL_BASE)
92 #define ext_irq_count		4
93 #define ext_irq_cfg_reg1	PERF_EXTIRQ_CFG_REG_6358
94 #define ext_irq_cfg_reg2	0
95 #endif
96 #ifdef CONFIG_BCM63XX_CPU_6362
97 #define irq_stat_reg		PERF_IRQSTAT_6362_REG
98 #define irq_mask_reg		PERF_IRQMASK_6362_REG
99 #define irq_bits		64
100 #define is_ext_irq_cascaded	1
101 #define ext_irq_start		(BCM_6362_EXT_IRQ0 - IRQ_INTERNAL_BASE)
102 #define ext_irq_end		(BCM_6362_EXT_IRQ3 - IRQ_INTERNAL_BASE)
103 #define ext_irq_count		4
104 #define ext_irq_cfg_reg1	PERF_EXTIRQ_CFG_REG_6362
105 #define ext_irq_cfg_reg2	0
106 #endif
107 #ifdef CONFIG_BCM63XX_CPU_6368
108 #define irq_stat_reg		PERF_IRQSTAT_6368_REG
109 #define irq_mask_reg		PERF_IRQMASK_6368_REG
110 #define irq_bits		64
111 #define is_ext_irq_cascaded	1
112 #define ext_irq_start		(BCM_6368_EXT_IRQ0 - IRQ_INTERNAL_BASE)
113 #define ext_irq_end		(BCM_6368_EXT_IRQ5 - IRQ_INTERNAL_BASE)
114 #define ext_irq_count		6
115 #define ext_irq_cfg_reg1	PERF_EXTIRQ_CFG_REG_6368
116 #define ext_irq_cfg_reg2	PERF_EXTIRQ_CFG_REG2_6368
117 #endif
118 
119 #if irq_bits == 32
120 #define dispatch_internal			__dispatch_internal
121 #define internal_irq_mask			__internal_irq_mask_32
122 #define internal_irq_unmask			__internal_irq_unmask_32
123 #else
124 #define dispatch_internal			__dispatch_internal_64
125 #define internal_irq_mask			__internal_irq_mask_64
126 #define internal_irq_unmask			__internal_irq_unmask_64
127 #endif
128 
129 #define irq_stat_addr	(bcm63xx_regset_address(RSET_PERF) + irq_stat_reg)
130 #define irq_mask_addr	(bcm63xx_regset_address(RSET_PERF) + irq_mask_reg)
131 
132 static inline void bcm63xx_init_irq(void)
133 {
134 }
135 #else /* ! BCMCPU_RUNTIME_DETECT */
136 
137 static u32 irq_stat_addr, irq_mask_addr;
138 static void (*dispatch_internal)(void);
139 static int is_ext_irq_cascaded;
140 static unsigned int ext_irq_count;
141 static unsigned int ext_irq_start, ext_irq_end;
142 static unsigned int ext_irq_cfg_reg1, ext_irq_cfg_reg2;
143 static void (*internal_irq_mask)(unsigned int irq);
144 static void (*internal_irq_unmask)(unsigned int irq);
145 
146 static void bcm63xx_init_irq(void)
147 {
148 	int irq_bits;
149 
150 	irq_stat_addr = bcm63xx_regset_address(RSET_PERF);
151 	irq_mask_addr = bcm63xx_regset_address(RSET_PERF);
152 
153 	switch (bcm63xx_get_cpu_id()) {
154 	case BCM3368_CPU_ID:
155 		irq_stat_addr += PERF_IRQSTAT_3368_REG;
156 		irq_mask_addr += PERF_IRQMASK_3368_REG;
157 		irq_bits = 32;
158 		ext_irq_count = 4;
159 		ext_irq_cfg_reg1 = PERF_EXTIRQ_CFG_REG_3368;
160 		break;
161 	case BCM6328_CPU_ID:
162 		irq_stat_addr += PERF_IRQSTAT_6328_REG;
163 		irq_mask_addr += PERF_IRQMASK_6328_REG;
164 		irq_bits = 64;
165 		ext_irq_count = 4;
166 		is_ext_irq_cascaded = 1;
167 		ext_irq_start = BCM_6328_EXT_IRQ0 - IRQ_INTERNAL_BASE;
168 		ext_irq_end = BCM_6328_EXT_IRQ3 - IRQ_INTERNAL_BASE;
169 		ext_irq_cfg_reg1 = PERF_EXTIRQ_CFG_REG_6328;
170 		break;
171 	case BCM6338_CPU_ID:
172 		irq_stat_addr += PERF_IRQSTAT_6338_REG;
173 		irq_mask_addr += PERF_IRQMASK_6338_REG;
174 		irq_bits = 32;
175 		ext_irq_count = 4;
176 		ext_irq_cfg_reg1 = PERF_EXTIRQ_CFG_REG_6338;
177 		break;
178 	case BCM6345_CPU_ID:
179 		irq_stat_addr += PERF_IRQSTAT_6345_REG;
180 		irq_mask_addr += PERF_IRQMASK_6345_REG;
181 		irq_bits = 32;
182 		ext_irq_count = 4;
183 		ext_irq_cfg_reg1 = PERF_EXTIRQ_CFG_REG_6345;
184 		break;
185 	case BCM6348_CPU_ID:
186 		irq_stat_addr += PERF_IRQSTAT_6348_REG;
187 		irq_mask_addr += PERF_IRQMASK_6348_REG;
188 		irq_bits = 32;
189 		ext_irq_count = 4;
190 		ext_irq_cfg_reg1 = PERF_EXTIRQ_CFG_REG_6348;
191 		break;
192 	case BCM6358_CPU_ID:
193 		irq_stat_addr += PERF_IRQSTAT_6358_REG;
194 		irq_mask_addr += PERF_IRQMASK_6358_REG;
195 		irq_bits = 32;
196 		ext_irq_count = 4;
197 		is_ext_irq_cascaded = 1;
198 		ext_irq_start = BCM_6358_EXT_IRQ0 - IRQ_INTERNAL_BASE;
199 		ext_irq_end = BCM_6358_EXT_IRQ3 - IRQ_INTERNAL_BASE;
200 		ext_irq_cfg_reg1 = PERF_EXTIRQ_CFG_REG_6358;
201 		break;
202 	case BCM6362_CPU_ID:
203 		irq_stat_addr += PERF_IRQSTAT_6362_REG;
204 		irq_mask_addr += PERF_IRQMASK_6362_REG;
205 		irq_bits = 64;
206 		ext_irq_count = 4;
207 		is_ext_irq_cascaded = 1;
208 		ext_irq_start = BCM_6362_EXT_IRQ0 - IRQ_INTERNAL_BASE;
209 		ext_irq_end = BCM_6362_EXT_IRQ3 - IRQ_INTERNAL_BASE;
210 		ext_irq_cfg_reg1 = PERF_EXTIRQ_CFG_REG_6362;
211 		break;
212 	case BCM6368_CPU_ID:
213 		irq_stat_addr += PERF_IRQSTAT_6368_REG;
214 		irq_mask_addr += PERF_IRQMASK_6368_REG;
215 		irq_bits = 64;
216 		ext_irq_count = 6;
217 		is_ext_irq_cascaded = 1;
218 		ext_irq_start = BCM_6368_EXT_IRQ0 - IRQ_INTERNAL_BASE;
219 		ext_irq_end = BCM_6368_EXT_IRQ5 - IRQ_INTERNAL_BASE;
220 		ext_irq_cfg_reg1 = PERF_EXTIRQ_CFG_REG_6368;
221 		ext_irq_cfg_reg2 = PERF_EXTIRQ_CFG_REG2_6368;
222 		break;
223 	default:
224 		BUG();
225 	}
226 
227 	if (irq_bits == 32) {
228 		dispatch_internal = __dispatch_internal;
229 		internal_irq_mask = __internal_irq_mask_32;
230 		internal_irq_unmask = __internal_irq_unmask_32;
231 	} else {
232 		dispatch_internal = __dispatch_internal_64;
233 		internal_irq_mask = __internal_irq_mask_64;
234 		internal_irq_unmask = __internal_irq_unmask_64;
235 	}
236 }
237 #endif /* ! BCMCPU_RUNTIME_DETECT */
238 
239 static inline u32 get_ext_irq_perf_reg(int irq)
240 {
241 	if (irq < 4)
242 		return ext_irq_cfg_reg1;
243 	return ext_irq_cfg_reg2;
244 }
245 
246 static inline void handle_internal(int intbit)
247 {
248 	if (is_ext_irq_cascaded &&
249 	    intbit >= ext_irq_start && intbit <= ext_irq_end)
250 		do_IRQ(intbit - ext_irq_start + IRQ_EXTERNAL_BASE);
251 	else
252 		do_IRQ(intbit + IRQ_INTERNAL_BASE);
253 }
254 
255 /*
256  * dispatch internal devices IRQ (uart, enet, watchdog, ...). do not
257  * prioritize any interrupt relatively to another. the static counter
258  * will resume the loop where it ended the last time we left this
259  * function.
260  */
261 static void __dispatch_internal(void)
262 {
263 	u32 pending;
264 	static int i;
265 
266 	pending = bcm_readl(irq_stat_addr) & bcm_readl(irq_mask_addr);
267 
268 	if (!pending)
269 		return ;
270 
271 	while (1) {
272 		int to_call = i;
273 
274 		i = (i + 1) & 0x1f;
275 		if (pending & (1 << to_call)) {
276 			handle_internal(to_call);
277 			break;
278 		}
279 	}
280 }
281 
282 static void __dispatch_internal_64(void)
283 {
284 	u64 pending;
285 	static int i;
286 
287 	pending = bcm_readq(irq_stat_addr) & bcm_readq(irq_mask_addr);
288 
289 	if (!pending)
290 		return ;
291 
292 	while (1) {
293 		int to_call = i;
294 
295 		i = (i + 1) & 0x3f;
296 		if (pending & (1ull << to_call)) {
297 			handle_internal(to_call);
298 			break;
299 		}
300 	}
301 }
302 
303 asmlinkage void plat_irq_dispatch(void)
304 {
305 	u32 cause;
306 
307 	do {
308 		cause = read_c0_cause() & read_c0_status() & ST0_IM;
309 
310 		if (!cause)
311 			break;
312 
313 		if (cause & CAUSEF_IP7)
314 			do_IRQ(7);
315 		if (cause & CAUSEF_IP0)
316 			do_IRQ(0);
317 		if (cause & CAUSEF_IP1)
318 			do_IRQ(1);
319 		if (cause & CAUSEF_IP2)
320 			dispatch_internal();
321 		if (!is_ext_irq_cascaded) {
322 			if (cause & CAUSEF_IP3)
323 				do_IRQ(IRQ_EXT_0);
324 			if (cause & CAUSEF_IP4)
325 				do_IRQ(IRQ_EXT_1);
326 			if (cause & CAUSEF_IP5)
327 				do_IRQ(IRQ_EXT_2);
328 			if (cause & CAUSEF_IP6)
329 				do_IRQ(IRQ_EXT_3);
330 		}
331 	} while (1);
332 }
333 
334 /*
335  * internal IRQs operations: only mask/unmask on PERF irq mask
336  * register.
337  */
338 static void __internal_irq_mask_32(unsigned int irq)
339 {
340 	u32 mask;
341 
342 	mask = bcm_readl(irq_mask_addr);
343 	mask &= ~(1 << irq);
344 	bcm_writel(mask, irq_mask_addr);
345 }
346 
347 static void __internal_irq_mask_64(unsigned int irq)
348 {
349 	u64 mask;
350 
351 	mask = bcm_readq(irq_mask_addr);
352 	mask &= ~(1ull << irq);
353 	bcm_writeq(mask, irq_mask_addr);
354 }
355 
356 static void __internal_irq_unmask_32(unsigned int irq)
357 {
358 	u32 mask;
359 
360 	mask = bcm_readl(irq_mask_addr);
361 	mask |= (1 << irq);
362 	bcm_writel(mask, irq_mask_addr);
363 }
364 
365 static void __internal_irq_unmask_64(unsigned int irq)
366 {
367 	u64 mask;
368 
369 	mask = bcm_readq(irq_mask_addr);
370 	mask |= (1ull << irq);
371 	bcm_writeq(mask, irq_mask_addr);
372 }
373 
374 static void bcm63xx_internal_irq_mask(struct irq_data *d)
375 {
376 	internal_irq_mask(d->irq - IRQ_INTERNAL_BASE);
377 }
378 
379 static void bcm63xx_internal_irq_unmask(struct irq_data *d)
380 {
381 	internal_irq_unmask(d->irq - IRQ_INTERNAL_BASE);
382 }
383 
384 /*
385  * external IRQs operations: mask/unmask and clear on PERF external
386  * irq control register.
387  */
388 static void bcm63xx_external_irq_mask(struct irq_data *d)
389 {
390 	unsigned int irq = d->irq - IRQ_EXTERNAL_BASE;
391 	u32 reg, regaddr;
392 
393 	regaddr = get_ext_irq_perf_reg(irq);
394 	reg = bcm_perf_readl(regaddr);
395 
396 	if (BCMCPU_IS_6348())
397 		reg &= ~EXTIRQ_CFG_MASK_6348(irq % 4);
398 	else
399 		reg &= ~EXTIRQ_CFG_MASK(irq % 4);
400 
401 	bcm_perf_writel(reg, regaddr);
402 	if (is_ext_irq_cascaded)
403 		internal_irq_mask(irq + ext_irq_start);
404 }
405 
406 static void bcm63xx_external_irq_unmask(struct irq_data *d)
407 {
408 	unsigned int irq = d->irq - IRQ_EXTERNAL_BASE;
409 	u32 reg, regaddr;
410 
411 	regaddr = get_ext_irq_perf_reg(irq);
412 	reg = bcm_perf_readl(regaddr);
413 
414 	if (BCMCPU_IS_6348())
415 		reg |= EXTIRQ_CFG_MASK_6348(irq % 4);
416 	else
417 		reg |= EXTIRQ_CFG_MASK(irq % 4);
418 
419 	bcm_perf_writel(reg, regaddr);
420 
421 	if (is_ext_irq_cascaded)
422 		internal_irq_unmask(irq + ext_irq_start);
423 }
424 
425 static void bcm63xx_external_irq_clear(struct irq_data *d)
426 {
427 	unsigned int irq = d->irq - IRQ_EXTERNAL_BASE;
428 	u32 reg, regaddr;
429 
430 	regaddr = get_ext_irq_perf_reg(irq);
431 	reg = bcm_perf_readl(regaddr);
432 
433 	if (BCMCPU_IS_6348())
434 		reg |= EXTIRQ_CFG_CLEAR_6348(irq % 4);
435 	else
436 		reg |= EXTIRQ_CFG_CLEAR(irq % 4);
437 
438 	bcm_perf_writel(reg, regaddr);
439 }
440 
441 static int bcm63xx_external_irq_set_type(struct irq_data *d,
442 					 unsigned int flow_type)
443 {
444 	unsigned int irq = d->irq - IRQ_EXTERNAL_BASE;
445 	u32 reg, regaddr;
446 	int levelsense, sense, bothedge;
447 
448 	flow_type &= IRQ_TYPE_SENSE_MASK;
449 
450 	if (flow_type == IRQ_TYPE_NONE)
451 		flow_type = IRQ_TYPE_LEVEL_LOW;
452 
453 	levelsense = sense = bothedge = 0;
454 	switch (flow_type) {
455 	case IRQ_TYPE_EDGE_BOTH:
456 		bothedge = 1;
457 		break;
458 
459 	case IRQ_TYPE_EDGE_RISING:
460 		sense = 1;
461 		break;
462 
463 	case IRQ_TYPE_EDGE_FALLING:
464 		break;
465 
466 	case IRQ_TYPE_LEVEL_HIGH:
467 		levelsense = 1;
468 		sense = 1;
469 		break;
470 
471 	case IRQ_TYPE_LEVEL_LOW:
472 		levelsense = 1;
473 		break;
474 
475 	default:
476 		printk(KERN_ERR "bogus flow type combination given !\n");
477 		return -EINVAL;
478 	}
479 
480 	regaddr = get_ext_irq_perf_reg(irq);
481 	reg = bcm_perf_readl(regaddr);
482 	irq %= 4;
483 
484 	switch (bcm63xx_get_cpu_id()) {
485 	case BCM6348_CPU_ID:
486 		if (levelsense)
487 			reg |= EXTIRQ_CFG_LEVELSENSE_6348(irq);
488 		else
489 			reg &= ~EXTIRQ_CFG_LEVELSENSE_6348(irq);
490 		if (sense)
491 			reg |= EXTIRQ_CFG_SENSE_6348(irq);
492 		else
493 			reg &= ~EXTIRQ_CFG_SENSE_6348(irq);
494 		if (bothedge)
495 			reg |= EXTIRQ_CFG_BOTHEDGE_6348(irq);
496 		else
497 			reg &= ~EXTIRQ_CFG_BOTHEDGE_6348(irq);
498 		break;
499 
500 	case BCM3368_CPU_ID:
501 	case BCM6328_CPU_ID:
502 	case BCM6338_CPU_ID:
503 	case BCM6345_CPU_ID:
504 	case BCM6358_CPU_ID:
505 	case BCM6362_CPU_ID:
506 	case BCM6368_CPU_ID:
507 		if (levelsense)
508 			reg |= EXTIRQ_CFG_LEVELSENSE(irq);
509 		else
510 			reg &= ~EXTIRQ_CFG_LEVELSENSE(irq);
511 		if (sense)
512 			reg |= EXTIRQ_CFG_SENSE(irq);
513 		else
514 			reg &= ~EXTIRQ_CFG_SENSE(irq);
515 		if (bothedge)
516 			reg |= EXTIRQ_CFG_BOTHEDGE(irq);
517 		else
518 			reg &= ~EXTIRQ_CFG_BOTHEDGE(irq);
519 		break;
520 	default:
521 		BUG();
522 	}
523 
524 	bcm_perf_writel(reg, regaddr);
525 
526 	irqd_set_trigger_type(d, flow_type);
527 	if (flow_type & (IRQ_TYPE_LEVEL_LOW | IRQ_TYPE_LEVEL_HIGH))
528 		__irq_set_handler_locked(d->irq, handle_level_irq);
529 	else
530 		__irq_set_handler_locked(d->irq, handle_edge_irq);
531 
532 	return IRQ_SET_MASK_OK_NOCOPY;
533 }
534 
535 static struct irq_chip bcm63xx_internal_irq_chip = {
536 	.name		= "bcm63xx_ipic",
537 	.irq_mask	= bcm63xx_internal_irq_mask,
538 	.irq_unmask	= bcm63xx_internal_irq_unmask,
539 };
540 
541 static struct irq_chip bcm63xx_external_irq_chip = {
542 	.name		= "bcm63xx_epic",
543 	.irq_ack	= bcm63xx_external_irq_clear,
544 
545 	.irq_mask	= bcm63xx_external_irq_mask,
546 	.irq_unmask	= bcm63xx_external_irq_unmask,
547 
548 	.irq_set_type	= bcm63xx_external_irq_set_type,
549 };
550 
551 static struct irqaction cpu_ip2_cascade_action = {
552 	.handler	= no_action,
553 	.name		= "cascade_ip2",
554 	.flags		= IRQF_NO_THREAD,
555 };
556 
557 static struct irqaction cpu_ext_cascade_action = {
558 	.handler	= no_action,
559 	.name		= "cascade_extirq",
560 	.flags		= IRQF_NO_THREAD,
561 };
562 
563 void __init arch_init_irq(void)
564 {
565 	int i;
566 
567 	bcm63xx_init_irq();
568 	mips_cpu_irq_init();
569 	for (i = IRQ_INTERNAL_BASE; i < NR_IRQS; ++i)
570 		irq_set_chip_and_handler(i, &bcm63xx_internal_irq_chip,
571 					 handle_level_irq);
572 
573 	for (i = IRQ_EXTERNAL_BASE; i < IRQ_EXTERNAL_BASE + ext_irq_count; ++i)
574 		irq_set_chip_and_handler(i, &bcm63xx_external_irq_chip,
575 					 handle_edge_irq);
576 
577 	if (!is_ext_irq_cascaded) {
578 		for (i = 3; i < 3 + ext_irq_count; ++i)
579 			setup_irq(MIPS_CPU_IRQ_BASE + i, &cpu_ext_cascade_action);
580 	}
581 
582 	setup_irq(MIPS_CPU_IRQ_BASE + 2, &cpu_ip2_cascade_action);
583 }
584