xref: /openbmc/linux/arch/mips/bcm63xx/irq.c (revision 8684014d)
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 <linux/spinlock.h>
16 #include <asm/irq_cpu.h>
17 #include <asm/mipsregs.h>
18 #include <bcm63xx_cpu.h>
19 #include <bcm63xx_regs.h>
20 #include <bcm63xx_io.h>
21 #include <bcm63xx_irq.h>
22 
23 
24 static DEFINE_SPINLOCK(ipic_lock);
25 static DEFINE_SPINLOCK(epic_lock);
26 
27 static u32 irq_stat_addr[2];
28 static u32 irq_mask_addr[2];
29 static void (*dispatch_internal)(int cpu);
30 static int is_ext_irq_cascaded;
31 static unsigned int ext_irq_count;
32 static unsigned int ext_irq_start, ext_irq_end;
33 static unsigned int ext_irq_cfg_reg1, ext_irq_cfg_reg2;
34 static void (*internal_irq_mask)(struct irq_data *d);
35 static void (*internal_irq_unmask)(struct irq_data *d, const struct cpumask *m);
36 
37 
38 static inline u32 get_ext_irq_perf_reg(int irq)
39 {
40 	if (irq < 4)
41 		return ext_irq_cfg_reg1;
42 	return ext_irq_cfg_reg2;
43 }
44 
45 static inline void handle_internal(int intbit)
46 {
47 	if (is_ext_irq_cascaded &&
48 	    intbit >= ext_irq_start && intbit <= ext_irq_end)
49 		do_IRQ(intbit - ext_irq_start + IRQ_EXTERNAL_BASE);
50 	else
51 		do_IRQ(intbit + IRQ_INTERNAL_BASE);
52 }
53 
54 static inline int enable_irq_for_cpu(int cpu, struct irq_data *d,
55 				     const struct cpumask *m)
56 {
57 	bool enable = cpu_online(cpu);
58 
59 #ifdef CONFIG_SMP
60 	if (m)
61 		enable &= cpu_isset(cpu, *m);
62 	else if (irqd_affinity_was_set(d))
63 		enable &= cpu_isset(cpu, *d->affinity);
64 #endif
65 	return enable;
66 }
67 
68 /*
69  * dispatch internal devices IRQ (uart, enet, watchdog, ...). do not
70  * prioritize any interrupt relatively to another. the static counter
71  * will resume the loop where it ended the last time we left this
72  * function.
73  */
74 
75 #define BUILD_IPIC_INTERNAL(width)					\
76 void __dispatch_internal_##width(int cpu)				\
77 {									\
78 	u32 pending[width / 32];					\
79 	unsigned int src, tgt;						\
80 	bool irqs_pending = false;					\
81 	static unsigned int i[2];					\
82 	unsigned int *next = &i[cpu];					\
83 	unsigned long flags;						\
84 									\
85 	/* read registers in reverse order */				\
86 	spin_lock_irqsave(&ipic_lock, flags);				\
87 	for (src = 0, tgt = (width / 32); src < (width / 32); src++) {	\
88 		u32 val;						\
89 									\
90 		val = bcm_readl(irq_stat_addr[cpu] + src * sizeof(u32)); \
91 		val &= bcm_readl(irq_mask_addr[cpu] + src * sizeof(u32)); \
92 		pending[--tgt] = val;					\
93 									\
94 		if (val)						\
95 			irqs_pending = true;				\
96 	}								\
97 	spin_unlock_irqrestore(&ipic_lock, flags);			\
98 									\
99 	if (!irqs_pending)						\
100 		return;							\
101 									\
102 	while (1) {							\
103 		unsigned int to_call = *next;				\
104 									\
105 		*next = (*next + 1) & (width - 1);			\
106 		if (pending[to_call / 32] & (1 << (to_call & 0x1f))) {	\
107 			handle_internal(to_call);			\
108 			break;						\
109 		}							\
110 	}								\
111 }									\
112 									\
113 static void __internal_irq_mask_##width(struct irq_data *d)		\
114 {									\
115 	u32 val;							\
116 	unsigned irq = d->irq - IRQ_INTERNAL_BASE;			\
117 	unsigned reg = (irq / 32) ^ (width/32 - 1);			\
118 	unsigned bit = irq & 0x1f;					\
119 	unsigned long flags;						\
120 	int cpu;							\
121 									\
122 	spin_lock_irqsave(&ipic_lock, flags);				\
123 	for_each_present_cpu(cpu) {					\
124 		if (!irq_mask_addr[cpu])				\
125 			break;						\
126 									\
127 		val = bcm_readl(irq_mask_addr[cpu] + reg * sizeof(u32));\
128 		val &= ~(1 << bit);					\
129 		bcm_writel(val, irq_mask_addr[cpu] + reg * sizeof(u32));\
130 	}								\
131 	spin_unlock_irqrestore(&ipic_lock, flags);			\
132 }									\
133 									\
134 static void __internal_irq_unmask_##width(struct irq_data *d,		\
135 					  const struct cpumask *m)	\
136 {									\
137 	u32 val;							\
138 	unsigned irq = d->irq - IRQ_INTERNAL_BASE;			\
139 	unsigned reg = (irq / 32) ^ (width/32 - 1);			\
140 	unsigned bit = irq & 0x1f;					\
141 	unsigned long flags;						\
142 	int cpu;							\
143 									\
144 	spin_lock_irqsave(&ipic_lock, flags);				\
145 	for_each_present_cpu(cpu) {					\
146 		if (!irq_mask_addr[cpu])				\
147 			break;						\
148 									\
149 		val = bcm_readl(irq_mask_addr[cpu] + reg * sizeof(u32));\
150 		if (enable_irq_for_cpu(cpu, d, m))			\
151 			val |= (1 << bit);				\
152 		else							\
153 			val &= ~(1 << bit);				\
154 		bcm_writel(val, irq_mask_addr[cpu] + reg * sizeof(u32));\
155 	}								\
156 	spin_unlock_irqrestore(&ipic_lock, flags);			\
157 }
158 
159 BUILD_IPIC_INTERNAL(32);
160 BUILD_IPIC_INTERNAL(64);
161 
162 asmlinkage void plat_irq_dispatch(void)
163 {
164 	u32 cause;
165 
166 	do {
167 		cause = read_c0_cause() & read_c0_status() & ST0_IM;
168 
169 		if (!cause)
170 			break;
171 
172 		if (cause & CAUSEF_IP7)
173 			do_IRQ(7);
174 		if (cause & CAUSEF_IP0)
175 			do_IRQ(0);
176 		if (cause & CAUSEF_IP1)
177 			do_IRQ(1);
178 		if (cause & CAUSEF_IP2)
179 			dispatch_internal(0);
180 		if (is_ext_irq_cascaded) {
181 			if (cause & CAUSEF_IP3)
182 				dispatch_internal(1);
183 		} else {
184 			if (cause & CAUSEF_IP3)
185 				do_IRQ(IRQ_EXT_0);
186 			if (cause & CAUSEF_IP4)
187 				do_IRQ(IRQ_EXT_1);
188 			if (cause & CAUSEF_IP5)
189 				do_IRQ(IRQ_EXT_2);
190 			if (cause & CAUSEF_IP6)
191 				do_IRQ(IRQ_EXT_3);
192 		}
193 	} while (1);
194 }
195 
196 /*
197  * internal IRQs operations: only mask/unmask on PERF irq mask
198  * register.
199  */
200 static void bcm63xx_internal_irq_mask(struct irq_data *d)
201 {
202 	internal_irq_mask(d);
203 }
204 
205 static void bcm63xx_internal_irq_unmask(struct irq_data *d)
206 {
207 	internal_irq_unmask(d, NULL);
208 }
209 
210 /*
211  * external IRQs operations: mask/unmask and clear on PERF external
212  * irq control register.
213  */
214 static void bcm63xx_external_irq_mask(struct irq_data *d)
215 {
216 	unsigned int irq = d->irq - IRQ_EXTERNAL_BASE;
217 	u32 reg, regaddr;
218 	unsigned long flags;
219 
220 	regaddr = get_ext_irq_perf_reg(irq);
221 	spin_lock_irqsave(&epic_lock, flags);
222 	reg = bcm_perf_readl(regaddr);
223 
224 	if (BCMCPU_IS_6348())
225 		reg &= ~EXTIRQ_CFG_MASK_6348(irq % 4);
226 	else
227 		reg &= ~EXTIRQ_CFG_MASK(irq % 4);
228 
229 	bcm_perf_writel(reg, regaddr);
230 	spin_unlock_irqrestore(&epic_lock, flags);
231 
232 	if (is_ext_irq_cascaded)
233 		internal_irq_mask(irq_get_irq_data(irq + ext_irq_start));
234 }
235 
236 static void bcm63xx_external_irq_unmask(struct irq_data *d)
237 {
238 	unsigned int irq = d->irq - IRQ_EXTERNAL_BASE;
239 	u32 reg, regaddr;
240 	unsigned long flags;
241 
242 	regaddr = get_ext_irq_perf_reg(irq);
243 	spin_lock_irqsave(&epic_lock, flags);
244 	reg = bcm_perf_readl(regaddr);
245 
246 	if (BCMCPU_IS_6348())
247 		reg |= EXTIRQ_CFG_MASK_6348(irq % 4);
248 	else
249 		reg |= EXTIRQ_CFG_MASK(irq % 4);
250 
251 	bcm_perf_writel(reg, regaddr);
252 	spin_unlock_irqrestore(&epic_lock, flags);
253 
254 	if (is_ext_irq_cascaded)
255 		internal_irq_unmask(irq_get_irq_data(irq + ext_irq_start),
256 				    NULL);
257 }
258 
259 static void bcm63xx_external_irq_clear(struct irq_data *d)
260 {
261 	unsigned int irq = d->irq - IRQ_EXTERNAL_BASE;
262 	u32 reg, regaddr;
263 	unsigned long flags;
264 
265 	regaddr = get_ext_irq_perf_reg(irq);
266 	spin_lock_irqsave(&epic_lock, flags);
267 	reg = bcm_perf_readl(regaddr);
268 
269 	if (BCMCPU_IS_6348())
270 		reg |= EXTIRQ_CFG_CLEAR_6348(irq % 4);
271 	else
272 		reg |= EXTIRQ_CFG_CLEAR(irq % 4);
273 
274 	bcm_perf_writel(reg, regaddr);
275 	spin_unlock_irqrestore(&epic_lock, flags);
276 }
277 
278 static int bcm63xx_external_irq_set_type(struct irq_data *d,
279 					 unsigned int flow_type)
280 {
281 	unsigned int irq = d->irq - IRQ_EXTERNAL_BASE;
282 	u32 reg, regaddr;
283 	int levelsense, sense, bothedge;
284 	unsigned long flags;
285 
286 	flow_type &= IRQ_TYPE_SENSE_MASK;
287 
288 	if (flow_type == IRQ_TYPE_NONE)
289 		flow_type = IRQ_TYPE_LEVEL_LOW;
290 
291 	levelsense = sense = bothedge = 0;
292 	switch (flow_type) {
293 	case IRQ_TYPE_EDGE_BOTH:
294 		bothedge = 1;
295 		break;
296 
297 	case IRQ_TYPE_EDGE_RISING:
298 		sense = 1;
299 		break;
300 
301 	case IRQ_TYPE_EDGE_FALLING:
302 		break;
303 
304 	case IRQ_TYPE_LEVEL_HIGH:
305 		levelsense = 1;
306 		sense = 1;
307 		break;
308 
309 	case IRQ_TYPE_LEVEL_LOW:
310 		levelsense = 1;
311 		break;
312 
313 	default:
314 		printk(KERN_ERR "bogus flow type combination given !\n");
315 		return -EINVAL;
316 	}
317 
318 	regaddr = get_ext_irq_perf_reg(irq);
319 	spin_lock_irqsave(&epic_lock, flags);
320 	reg = bcm_perf_readl(regaddr);
321 	irq %= 4;
322 
323 	switch (bcm63xx_get_cpu_id()) {
324 	case BCM6348_CPU_ID:
325 		if (levelsense)
326 			reg |= EXTIRQ_CFG_LEVELSENSE_6348(irq);
327 		else
328 			reg &= ~EXTIRQ_CFG_LEVELSENSE_6348(irq);
329 		if (sense)
330 			reg |= EXTIRQ_CFG_SENSE_6348(irq);
331 		else
332 			reg &= ~EXTIRQ_CFG_SENSE_6348(irq);
333 		if (bothedge)
334 			reg |= EXTIRQ_CFG_BOTHEDGE_6348(irq);
335 		else
336 			reg &= ~EXTIRQ_CFG_BOTHEDGE_6348(irq);
337 		break;
338 
339 	case BCM3368_CPU_ID:
340 	case BCM6328_CPU_ID:
341 	case BCM6338_CPU_ID:
342 	case BCM6345_CPU_ID:
343 	case BCM6358_CPU_ID:
344 	case BCM6362_CPU_ID:
345 	case BCM6368_CPU_ID:
346 		if (levelsense)
347 			reg |= EXTIRQ_CFG_LEVELSENSE(irq);
348 		else
349 			reg &= ~EXTIRQ_CFG_LEVELSENSE(irq);
350 		if (sense)
351 			reg |= EXTIRQ_CFG_SENSE(irq);
352 		else
353 			reg &= ~EXTIRQ_CFG_SENSE(irq);
354 		if (bothedge)
355 			reg |= EXTIRQ_CFG_BOTHEDGE(irq);
356 		else
357 			reg &= ~EXTIRQ_CFG_BOTHEDGE(irq);
358 		break;
359 	default:
360 		BUG();
361 	}
362 
363 	bcm_perf_writel(reg, regaddr);
364 	spin_unlock_irqrestore(&epic_lock, flags);
365 
366 	irqd_set_trigger_type(d, flow_type);
367 	if (flow_type & (IRQ_TYPE_LEVEL_LOW | IRQ_TYPE_LEVEL_HIGH))
368 		__irq_set_handler_locked(d->irq, handle_level_irq);
369 	else
370 		__irq_set_handler_locked(d->irq, handle_edge_irq);
371 
372 	return IRQ_SET_MASK_OK_NOCOPY;
373 }
374 
375 #ifdef CONFIG_SMP
376 static int bcm63xx_internal_set_affinity(struct irq_data *data,
377 					 const struct cpumask *dest,
378 					 bool force)
379 {
380 	if (!irqd_irq_disabled(data))
381 		internal_irq_unmask(data, dest);
382 
383 	return 0;
384 }
385 #endif
386 
387 static struct irq_chip bcm63xx_internal_irq_chip = {
388 	.name		= "bcm63xx_ipic",
389 	.irq_mask	= bcm63xx_internal_irq_mask,
390 	.irq_unmask	= bcm63xx_internal_irq_unmask,
391 };
392 
393 static struct irq_chip bcm63xx_external_irq_chip = {
394 	.name		= "bcm63xx_epic",
395 	.irq_ack	= bcm63xx_external_irq_clear,
396 
397 	.irq_mask	= bcm63xx_external_irq_mask,
398 	.irq_unmask	= bcm63xx_external_irq_unmask,
399 
400 	.irq_set_type	= bcm63xx_external_irq_set_type,
401 };
402 
403 static struct irqaction cpu_ip2_cascade_action = {
404 	.handler	= no_action,
405 	.name		= "cascade_ip2",
406 	.flags		= IRQF_NO_THREAD,
407 };
408 
409 #ifdef CONFIG_SMP
410 static struct irqaction cpu_ip3_cascade_action = {
411 	.handler	= no_action,
412 	.name		= "cascade_ip3",
413 	.flags		= IRQF_NO_THREAD,
414 };
415 #endif
416 
417 static struct irqaction cpu_ext_cascade_action = {
418 	.handler	= no_action,
419 	.name		= "cascade_extirq",
420 	.flags		= IRQF_NO_THREAD,
421 };
422 
423 static void bcm63xx_init_irq(void)
424 {
425 	int irq_bits;
426 
427 	irq_stat_addr[0] = bcm63xx_regset_address(RSET_PERF);
428 	irq_mask_addr[0] = bcm63xx_regset_address(RSET_PERF);
429 	irq_stat_addr[1] = bcm63xx_regset_address(RSET_PERF);
430 	irq_mask_addr[1] = bcm63xx_regset_address(RSET_PERF);
431 
432 	switch (bcm63xx_get_cpu_id()) {
433 	case BCM3368_CPU_ID:
434 		irq_stat_addr[0] += PERF_IRQSTAT_3368_REG;
435 		irq_mask_addr[0] += PERF_IRQMASK_3368_REG;
436 		irq_stat_addr[1] = 0;
437 		irq_mask_addr[1] = 0;
438 		irq_bits = 32;
439 		ext_irq_count = 4;
440 		ext_irq_cfg_reg1 = PERF_EXTIRQ_CFG_REG_3368;
441 		break;
442 	case BCM6328_CPU_ID:
443 		irq_stat_addr[0] += PERF_IRQSTAT_6328_REG(0);
444 		irq_mask_addr[0] += PERF_IRQMASK_6328_REG(0);
445 		irq_stat_addr[1] += PERF_IRQSTAT_6328_REG(1);
446 		irq_mask_addr[1] += PERF_IRQMASK_6328_REG(1);
447 		irq_bits = 64;
448 		ext_irq_count = 4;
449 		is_ext_irq_cascaded = 1;
450 		ext_irq_start = BCM_6328_EXT_IRQ0 - IRQ_INTERNAL_BASE;
451 		ext_irq_end = BCM_6328_EXT_IRQ3 - IRQ_INTERNAL_BASE;
452 		ext_irq_cfg_reg1 = PERF_EXTIRQ_CFG_REG_6328;
453 		break;
454 	case BCM6338_CPU_ID:
455 		irq_stat_addr[0] += PERF_IRQSTAT_6338_REG;
456 		irq_mask_addr[0] += PERF_IRQMASK_6338_REG;
457 		irq_stat_addr[1] = 0;
458 		irq_mask_addr[1] = 0;
459 		irq_bits = 32;
460 		ext_irq_count = 4;
461 		ext_irq_cfg_reg1 = PERF_EXTIRQ_CFG_REG_6338;
462 		break;
463 	case BCM6345_CPU_ID:
464 		irq_stat_addr[0] += PERF_IRQSTAT_6345_REG;
465 		irq_mask_addr[0] += PERF_IRQMASK_6345_REG;
466 		irq_stat_addr[1] = 0;
467 		irq_mask_addr[1] = 0;
468 		irq_bits = 32;
469 		ext_irq_count = 4;
470 		ext_irq_cfg_reg1 = PERF_EXTIRQ_CFG_REG_6345;
471 		break;
472 	case BCM6348_CPU_ID:
473 		irq_stat_addr[0] += PERF_IRQSTAT_6348_REG;
474 		irq_mask_addr[0] += PERF_IRQMASK_6348_REG;
475 		irq_stat_addr[1] = 0;
476 		irq_mask_addr[1] = 0;
477 		irq_bits = 32;
478 		ext_irq_count = 4;
479 		ext_irq_cfg_reg1 = PERF_EXTIRQ_CFG_REG_6348;
480 		break;
481 	case BCM6358_CPU_ID:
482 		irq_stat_addr[0] += PERF_IRQSTAT_6358_REG(0);
483 		irq_mask_addr[0] += PERF_IRQMASK_6358_REG(0);
484 		irq_stat_addr[1] += PERF_IRQSTAT_6358_REG(1);
485 		irq_mask_addr[1] += PERF_IRQMASK_6358_REG(1);
486 		irq_bits = 32;
487 		ext_irq_count = 4;
488 		is_ext_irq_cascaded = 1;
489 		ext_irq_start = BCM_6358_EXT_IRQ0 - IRQ_INTERNAL_BASE;
490 		ext_irq_end = BCM_6358_EXT_IRQ3 - IRQ_INTERNAL_BASE;
491 		ext_irq_cfg_reg1 = PERF_EXTIRQ_CFG_REG_6358;
492 		break;
493 	case BCM6362_CPU_ID:
494 		irq_stat_addr[0] += PERF_IRQSTAT_6362_REG(0);
495 		irq_mask_addr[0] += PERF_IRQMASK_6362_REG(0);
496 		irq_stat_addr[1] += PERF_IRQSTAT_6362_REG(1);
497 		irq_mask_addr[1] += PERF_IRQMASK_6362_REG(1);
498 		irq_bits = 64;
499 		ext_irq_count = 4;
500 		is_ext_irq_cascaded = 1;
501 		ext_irq_start = BCM_6362_EXT_IRQ0 - IRQ_INTERNAL_BASE;
502 		ext_irq_end = BCM_6362_EXT_IRQ3 - IRQ_INTERNAL_BASE;
503 		ext_irq_cfg_reg1 = PERF_EXTIRQ_CFG_REG_6362;
504 		break;
505 	case BCM6368_CPU_ID:
506 		irq_stat_addr[0] += PERF_IRQSTAT_6368_REG(0);
507 		irq_mask_addr[0] += PERF_IRQMASK_6368_REG(0);
508 		irq_stat_addr[1] += PERF_IRQSTAT_6368_REG(1);
509 		irq_mask_addr[1] += PERF_IRQMASK_6368_REG(1);
510 		irq_bits = 64;
511 		ext_irq_count = 6;
512 		is_ext_irq_cascaded = 1;
513 		ext_irq_start = BCM_6368_EXT_IRQ0 - IRQ_INTERNAL_BASE;
514 		ext_irq_end = BCM_6368_EXT_IRQ5 - IRQ_INTERNAL_BASE;
515 		ext_irq_cfg_reg1 = PERF_EXTIRQ_CFG_REG_6368;
516 		ext_irq_cfg_reg2 = PERF_EXTIRQ_CFG_REG2_6368;
517 		break;
518 	default:
519 		BUG();
520 	}
521 
522 	if (irq_bits == 32) {
523 		dispatch_internal = __dispatch_internal_32;
524 		internal_irq_mask = __internal_irq_mask_32;
525 		internal_irq_unmask = __internal_irq_unmask_32;
526 	} else {
527 		dispatch_internal = __dispatch_internal_64;
528 		internal_irq_mask = __internal_irq_mask_64;
529 		internal_irq_unmask = __internal_irq_unmask_64;
530 	}
531 }
532 
533 void __init arch_init_irq(void)
534 {
535 	int i;
536 
537 	bcm63xx_init_irq();
538 	mips_cpu_irq_init();
539 	for (i = IRQ_INTERNAL_BASE; i < NR_IRQS; ++i)
540 		irq_set_chip_and_handler(i, &bcm63xx_internal_irq_chip,
541 					 handle_level_irq);
542 
543 	for (i = IRQ_EXTERNAL_BASE; i < IRQ_EXTERNAL_BASE + ext_irq_count; ++i)
544 		irq_set_chip_and_handler(i, &bcm63xx_external_irq_chip,
545 					 handle_edge_irq);
546 
547 	if (!is_ext_irq_cascaded) {
548 		for (i = 3; i < 3 + ext_irq_count; ++i)
549 			setup_irq(MIPS_CPU_IRQ_BASE + i, &cpu_ext_cascade_action);
550 	}
551 
552 	setup_irq(MIPS_CPU_IRQ_BASE + 2, &cpu_ip2_cascade_action);
553 #ifdef CONFIG_SMP
554 	if (is_ext_irq_cascaded) {
555 		setup_irq(MIPS_CPU_IRQ_BASE + 3, &cpu_ip3_cascade_action);
556 		bcm63xx_internal_irq_chip.irq_set_affinity =
557 			bcm63xx_internal_set_affinity;
558 
559 		cpumask_clear(irq_default_affinity);
560 		cpumask_set_cpu(smp_processor_id(), irq_default_affinity);
561 	}
562 #endif
563 }
564