xref: /linux/drivers/irqchip/irq-mips-gic.c (revision e5d3a64e650c721f9e9b1f76e5df8c62f16b734d)
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 Ralf Baechle (ralf@linux-mips.org)
7  * Copyright (C) 2012 MIPS Technologies, Inc.  All rights reserved.
8  */
9 
10 #define pr_fmt(fmt) "irq-mips-gic: " fmt
11 
12 #include <linux/bitfield.h>
13 #include <linux/bitmap.h>
14 #include <linux/clocksource.h>
15 #include <linux/cpuhotplug.h>
16 #include <linux/init.h>
17 #include <linux/interrupt.h>
18 #include <linux/irq.h>
19 #include <linux/irqchip.h>
20 #include <linux/irqdomain.h>
21 #include <linux/of_address.h>
22 #include <linux/percpu.h>
23 #include <linux/sched.h>
24 #include <linux/smp.h>
25 
26 #include <asm/mips-cps.h>
27 #include <asm/setup.h>
28 #include <asm/traps.h>
29 
30 #include <dt-bindings/interrupt-controller/mips-gic.h>
31 
32 #define GIC_MAX_INTRS		256
33 #define GIC_MAX_LONGS		BITS_TO_LONGS(GIC_MAX_INTRS)
34 
35 /* Add 2 to convert GIC CPU pin to core interrupt */
36 #define GIC_CPU_PIN_OFFSET	2
37 
38 /* Mapped interrupt to pin X, then GIC will generate the vector (X+1). */
39 #define GIC_PIN_TO_VEC_OFFSET	1
40 
41 /* Convert between local/shared IRQ number and GIC HW IRQ number. */
42 #define GIC_LOCAL_HWIRQ_BASE	0
43 #define GIC_LOCAL_TO_HWIRQ(x)	(GIC_LOCAL_HWIRQ_BASE + (x))
44 #define GIC_HWIRQ_TO_LOCAL(x)	((x) - GIC_LOCAL_HWIRQ_BASE)
45 #define GIC_SHARED_HWIRQ_BASE	GIC_NUM_LOCAL_INTRS
46 #define GIC_SHARED_TO_HWIRQ(x)	(GIC_SHARED_HWIRQ_BASE + (x))
47 #define GIC_HWIRQ_TO_SHARED(x)	((x) - GIC_SHARED_HWIRQ_BASE)
48 
49 void __iomem *mips_gic_base;
50 
51 static DEFINE_PER_CPU_READ_MOSTLY(unsigned long[GIC_MAX_LONGS], pcpu_masks);
52 
53 static DEFINE_SPINLOCK(gic_lock);
54 static struct irq_domain *gic_irq_domain;
55 static int gic_shared_intrs;
56 static unsigned int gic_cpu_pin;
57 static unsigned int timer_cpu_pin;
58 static struct irq_chip gic_level_irq_controller, gic_edge_irq_controller;
59 
60 #ifdef CONFIG_GENERIC_IRQ_IPI
61 static DECLARE_BITMAP(ipi_resrv, GIC_MAX_INTRS);
62 static DECLARE_BITMAP(ipi_available, GIC_MAX_INTRS);
63 #endif /* CONFIG_GENERIC_IRQ_IPI */
64 
65 static struct gic_all_vpes_chip_data {
66 	u32	map;
67 	bool	mask;
68 } gic_all_vpes_chip_data[GIC_NUM_LOCAL_INTRS];
69 
70 static void gic_clear_pcpu_masks(unsigned int intr)
71 {
72 	unsigned int i;
73 
74 	/* Clear the interrupt's bit in all pcpu_masks */
75 	for_each_possible_cpu(i)
76 		clear_bit(intr, per_cpu_ptr(pcpu_masks, i));
77 }
78 
79 static bool gic_local_irq_is_routable(int intr)
80 {
81 	u32 vpe_ctl;
82 
83 	/* All local interrupts are routable in EIC mode. */
84 	if (cpu_has_veic)
85 		return true;
86 
87 	vpe_ctl = read_gic_vl_ctl();
88 	switch (intr) {
89 	case GIC_LOCAL_INT_TIMER:
90 		return vpe_ctl & GIC_VX_CTL_TIMER_ROUTABLE;
91 	case GIC_LOCAL_INT_PERFCTR:
92 		return vpe_ctl & GIC_VX_CTL_PERFCNT_ROUTABLE;
93 	case GIC_LOCAL_INT_FDC:
94 		return vpe_ctl & GIC_VX_CTL_FDC_ROUTABLE;
95 	case GIC_LOCAL_INT_SWINT0:
96 	case GIC_LOCAL_INT_SWINT1:
97 		return vpe_ctl & GIC_VX_CTL_SWINT_ROUTABLE;
98 	default:
99 		return true;
100 	}
101 }
102 
103 static void gic_bind_eic_interrupt(int irq, int set)
104 {
105 	/* Convert irq vector # to hw int # */
106 	irq -= GIC_PIN_TO_VEC_OFFSET;
107 
108 	/* Set irq to use shadow set */
109 	write_gic_vl_eic_shadow_set(irq, set);
110 }
111 
112 static void gic_send_ipi(struct irq_data *d, unsigned int cpu)
113 {
114 	irq_hw_number_t hwirq = GIC_HWIRQ_TO_SHARED(irqd_to_hwirq(d));
115 
116 	write_gic_wedge(GIC_WEDGE_RW | hwirq);
117 }
118 
119 int gic_get_c0_compare_int(void)
120 {
121 	if (!gic_local_irq_is_routable(GIC_LOCAL_INT_TIMER))
122 		return MIPS_CPU_IRQ_BASE + cp0_compare_irq;
123 	return irq_create_mapping(gic_irq_domain,
124 				  GIC_LOCAL_TO_HWIRQ(GIC_LOCAL_INT_TIMER));
125 }
126 
127 int gic_get_c0_perfcount_int(void)
128 {
129 	if (!gic_local_irq_is_routable(GIC_LOCAL_INT_PERFCTR)) {
130 		/* Is the performance counter shared with the timer? */
131 		if (cp0_perfcount_irq < 0)
132 			return -1;
133 		return MIPS_CPU_IRQ_BASE + cp0_perfcount_irq;
134 	}
135 	return irq_create_mapping(gic_irq_domain,
136 				  GIC_LOCAL_TO_HWIRQ(GIC_LOCAL_INT_PERFCTR));
137 }
138 
139 int gic_get_c0_fdc_int(void)
140 {
141 	if (!gic_local_irq_is_routable(GIC_LOCAL_INT_FDC)) {
142 		/* Is the FDC IRQ even present? */
143 		if (cp0_fdc_irq < 0)
144 			return -1;
145 		return MIPS_CPU_IRQ_BASE + cp0_fdc_irq;
146 	}
147 
148 	return irq_create_mapping(gic_irq_domain,
149 				  GIC_LOCAL_TO_HWIRQ(GIC_LOCAL_INT_FDC));
150 }
151 
152 static void gic_handle_shared_int(bool chained)
153 {
154 	unsigned int intr;
155 	unsigned long *pcpu_mask;
156 	DECLARE_BITMAP(pending, GIC_MAX_INTRS);
157 
158 	/* Get per-cpu bitmaps */
159 	pcpu_mask = this_cpu_ptr(pcpu_masks);
160 
161 	if (mips_cm_is64)
162 		__ioread64_copy(pending, addr_gic_pend(),
163 				DIV_ROUND_UP(gic_shared_intrs, 64));
164 	else
165 		__ioread32_copy(pending, addr_gic_pend(),
166 				DIV_ROUND_UP(gic_shared_intrs, 32));
167 
168 	bitmap_and(pending, pending, pcpu_mask, gic_shared_intrs);
169 
170 	for_each_set_bit(intr, pending, gic_shared_intrs) {
171 		if (chained)
172 			generic_handle_domain_irq(gic_irq_domain,
173 						  GIC_SHARED_TO_HWIRQ(intr));
174 		else
175 			do_domain_IRQ(gic_irq_domain,
176 				      GIC_SHARED_TO_HWIRQ(intr));
177 	}
178 }
179 
180 static void gic_mask_irq(struct irq_data *d)
181 {
182 	unsigned int intr = GIC_HWIRQ_TO_SHARED(d->hwirq);
183 
184 	write_gic_rmask(intr);
185 	gic_clear_pcpu_masks(intr);
186 }
187 
188 static void gic_unmask_irq(struct irq_data *d)
189 {
190 	unsigned int intr = GIC_HWIRQ_TO_SHARED(d->hwirq);
191 	unsigned int cpu;
192 
193 	write_gic_smask(intr);
194 
195 	gic_clear_pcpu_masks(intr);
196 	cpu = cpumask_first(irq_data_get_effective_affinity_mask(d));
197 	set_bit(intr, per_cpu_ptr(pcpu_masks, cpu));
198 }
199 
200 static void gic_ack_irq(struct irq_data *d)
201 {
202 	unsigned int irq = GIC_HWIRQ_TO_SHARED(d->hwirq);
203 
204 	write_gic_wedge(irq);
205 }
206 
207 static int gic_set_type(struct irq_data *d, unsigned int type)
208 {
209 	unsigned int irq, pol, trig, dual;
210 	unsigned long flags;
211 
212 	irq = GIC_HWIRQ_TO_SHARED(d->hwirq);
213 
214 	spin_lock_irqsave(&gic_lock, flags);
215 	switch (type & IRQ_TYPE_SENSE_MASK) {
216 	case IRQ_TYPE_EDGE_FALLING:
217 		pol = GIC_POL_FALLING_EDGE;
218 		trig = GIC_TRIG_EDGE;
219 		dual = GIC_DUAL_SINGLE;
220 		break;
221 	case IRQ_TYPE_EDGE_RISING:
222 		pol = GIC_POL_RISING_EDGE;
223 		trig = GIC_TRIG_EDGE;
224 		dual = GIC_DUAL_SINGLE;
225 		break;
226 	case IRQ_TYPE_EDGE_BOTH:
227 		pol = 0; /* Doesn't matter */
228 		trig = GIC_TRIG_EDGE;
229 		dual = GIC_DUAL_DUAL;
230 		break;
231 	case IRQ_TYPE_LEVEL_LOW:
232 		pol = GIC_POL_ACTIVE_LOW;
233 		trig = GIC_TRIG_LEVEL;
234 		dual = GIC_DUAL_SINGLE;
235 		break;
236 	case IRQ_TYPE_LEVEL_HIGH:
237 	default:
238 		pol = GIC_POL_ACTIVE_HIGH;
239 		trig = GIC_TRIG_LEVEL;
240 		dual = GIC_DUAL_SINGLE;
241 		break;
242 	}
243 
244 	change_gic_pol(irq, pol);
245 	change_gic_trig(irq, trig);
246 	change_gic_dual(irq, dual);
247 
248 	if (trig == GIC_TRIG_EDGE)
249 		irq_set_chip_handler_name_locked(d, &gic_edge_irq_controller,
250 						 handle_edge_irq, NULL);
251 	else
252 		irq_set_chip_handler_name_locked(d, &gic_level_irq_controller,
253 						 handle_level_irq, NULL);
254 	spin_unlock_irqrestore(&gic_lock, flags);
255 
256 	return 0;
257 }
258 
259 #ifdef CONFIG_SMP
260 static int gic_set_affinity(struct irq_data *d, const struct cpumask *cpumask,
261 			    bool force)
262 {
263 	unsigned int irq = GIC_HWIRQ_TO_SHARED(d->hwirq);
264 	unsigned long flags;
265 	unsigned int cpu;
266 
267 	cpu = cpumask_first_and(cpumask, cpu_online_mask);
268 	if (cpu >= NR_CPUS)
269 		return -EINVAL;
270 
271 	/* Assumption : cpumask refers to a single CPU */
272 	spin_lock_irqsave(&gic_lock, flags);
273 
274 	/* Re-route this IRQ */
275 	write_gic_map_vp(irq, BIT(mips_cm_vp_id(cpu)));
276 
277 	/* Update the pcpu_masks */
278 	gic_clear_pcpu_masks(irq);
279 	if (read_gic_mask(irq))
280 		set_bit(irq, per_cpu_ptr(pcpu_masks, cpu));
281 
282 	irq_data_update_effective_affinity(d, cpumask_of(cpu));
283 	spin_unlock_irqrestore(&gic_lock, flags);
284 
285 	return IRQ_SET_MASK_OK;
286 }
287 #endif
288 
289 static struct irq_chip gic_level_irq_controller = {
290 	.name			=	"MIPS GIC",
291 	.irq_mask		=	gic_mask_irq,
292 	.irq_unmask		=	gic_unmask_irq,
293 	.irq_set_type		=	gic_set_type,
294 #ifdef CONFIG_SMP
295 	.irq_set_affinity	=	gic_set_affinity,
296 #endif
297 };
298 
299 static struct irq_chip gic_edge_irq_controller = {
300 	.name			=	"MIPS GIC",
301 	.irq_ack		=	gic_ack_irq,
302 	.irq_mask		=	gic_mask_irq,
303 	.irq_unmask		=	gic_unmask_irq,
304 	.irq_set_type		=	gic_set_type,
305 #ifdef CONFIG_SMP
306 	.irq_set_affinity	=	gic_set_affinity,
307 #endif
308 	.ipi_send_single	=	gic_send_ipi,
309 };
310 
311 static void gic_handle_local_int(bool chained)
312 {
313 	unsigned long pending, masked;
314 	unsigned int intr;
315 
316 	pending = read_gic_vl_pend();
317 	masked = read_gic_vl_mask();
318 
319 	bitmap_and(&pending, &pending, &masked, GIC_NUM_LOCAL_INTRS);
320 
321 	for_each_set_bit(intr, &pending, GIC_NUM_LOCAL_INTRS) {
322 		if (chained)
323 			generic_handle_domain_irq(gic_irq_domain,
324 						  GIC_LOCAL_TO_HWIRQ(intr));
325 		else
326 			do_domain_IRQ(gic_irq_domain,
327 				      GIC_LOCAL_TO_HWIRQ(intr));
328 	}
329 }
330 
331 static void gic_mask_local_irq(struct irq_data *d)
332 {
333 	int intr = GIC_HWIRQ_TO_LOCAL(d->hwirq);
334 
335 	write_gic_vl_rmask(BIT(intr));
336 }
337 
338 static void gic_unmask_local_irq(struct irq_data *d)
339 {
340 	int intr = GIC_HWIRQ_TO_LOCAL(d->hwirq);
341 
342 	write_gic_vl_smask(BIT(intr));
343 }
344 
345 static struct irq_chip gic_local_irq_controller = {
346 	.name			=	"MIPS GIC Local",
347 	.irq_mask		=	gic_mask_local_irq,
348 	.irq_unmask		=	gic_unmask_local_irq,
349 };
350 
351 static void gic_mask_local_irq_all_vpes(struct irq_data *d)
352 {
353 	struct gic_all_vpes_chip_data *cd;
354 	unsigned long flags;
355 	int intr, cpu;
356 
357 	intr = GIC_HWIRQ_TO_LOCAL(d->hwirq);
358 	cd = irq_data_get_irq_chip_data(d);
359 	cd->mask = false;
360 
361 	spin_lock_irqsave(&gic_lock, flags);
362 	for_each_online_cpu(cpu) {
363 		write_gic_vl_other(mips_cm_vp_id(cpu));
364 		write_gic_vo_rmask(BIT(intr));
365 	}
366 	spin_unlock_irqrestore(&gic_lock, flags);
367 }
368 
369 static void gic_unmask_local_irq_all_vpes(struct irq_data *d)
370 {
371 	struct gic_all_vpes_chip_data *cd;
372 	unsigned long flags;
373 	int intr, cpu;
374 
375 	intr = GIC_HWIRQ_TO_LOCAL(d->hwirq);
376 	cd = irq_data_get_irq_chip_data(d);
377 	cd->mask = true;
378 
379 	spin_lock_irqsave(&gic_lock, flags);
380 	for_each_online_cpu(cpu) {
381 		write_gic_vl_other(mips_cm_vp_id(cpu));
382 		write_gic_vo_smask(BIT(intr));
383 	}
384 	spin_unlock_irqrestore(&gic_lock, flags);
385 }
386 
387 static void gic_all_vpes_irq_cpu_online(void)
388 {
389 	static const unsigned int local_intrs[] = {
390 		GIC_LOCAL_INT_TIMER,
391 		GIC_LOCAL_INT_PERFCTR,
392 		GIC_LOCAL_INT_FDC,
393 	};
394 	unsigned long flags;
395 	int i;
396 
397 	spin_lock_irqsave(&gic_lock, flags);
398 
399 	for (i = 0; i < ARRAY_SIZE(local_intrs); i++) {
400 		unsigned int intr = local_intrs[i];
401 		struct gic_all_vpes_chip_data *cd;
402 
403 		cd = &gic_all_vpes_chip_data[intr];
404 		write_gic_vl_map(mips_gic_vx_map_reg(intr), cd->map);
405 		if (cd->mask)
406 			write_gic_vl_smask(BIT(intr));
407 	}
408 
409 	spin_unlock_irqrestore(&gic_lock, flags);
410 }
411 
412 static struct irq_chip gic_all_vpes_local_irq_controller = {
413 	.name			= "MIPS GIC Local",
414 	.irq_mask		= gic_mask_local_irq_all_vpes,
415 	.irq_unmask		= gic_unmask_local_irq_all_vpes,
416 };
417 
418 static void __gic_irq_dispatch(void)
419 {
420 	gic_handle_local_int(false);
421 	gic_handle_shared_int(false);
422 }
423 
424 static void gic_irq_dispatch(struct irq_desc *desc)
425 {
426 	gic_handle_local_int(true);
427 	gic_handle_shared_int(true);
428 }
429 
430 static int gic_shared_irq_domain_map(struct irq_domain *d, unsigned int virq,
431 				     irq_hw_number_t hw, unsigned int cpu)
432 {
433 	int intr = GIC_HWIRQ_TO_SHARED(hw);
434 	struct irq_data *data;
435 	unsigned long flags;
436 
437 	data = irq_get_irq_data(virq);
438 
439 	spin_lock_irqsave(&gic_lock, flags);
440 	write_gic_map_pin(intr, GIC_MAP_PIN_MAP_TO_PIN | gic_cpu_pin);
441 	write_gic_map_vp(intr, BIT(mips_cm_vp_id(cpu)));
442 	irq_data_update_effective_affinity(data, cpumask_of(cpu));
443 	spin_unlock_irqrestore(&gic_lock, flags);
444 
445 	return 0;
446 }
447 
448 static int gic_irq_domain_xlate(struct irq_domain *d, struct device_node *ctrlr,
449 				const u32 *intspec, unsigned int intsize,
450 				irq_hw_number_t *out_hwirq,
451 				unsigned int *out_type)
452 {
453 	if (intsize != 3)
454 		return -EINVAL;
455 
456 	if (intspec[0] == GIC_SHARED)
457 		*out_hwirq = GIC_SHARED_TO_HWIRQ(intspec[1]);
458 	else if (intspec[0] == GIC_LOCAL)
459 		*out_hwirq = GIC_LOCAL_TO_HWIRQ(intspec[1]);
460 	else
461 		return -EINVAL;
462 	*out_type = intspec[2] & IRQ_TYPE_SENSE_MASK;
463 
464 	return 0;
465 }
466 
467 static int gic_irq_domain_map(struct irq_domain *d, unsigned int virq,
468 			      irq_hw_number_t hwirq)
469 {
470 	struct gic_all_vpes_chip_data *cd;
471 	unsigned long flags;
472 	unsigned int intr;
473 	int err, cpu;
474 	u32 map;
475 
476 	if (hwirq >= GIC_SHARED_HWIRQ_BASE) {
477 #ifdef CONFIG_GENERIC_IRQ_IPI
478 		/* verify that shared irqs don't conflict with an IPI irq */
479 		if (test_bit(GIC_HWIRQ_TO_SHARED(hwirq), ipi_resrv))
480 			return -EBUSY;
481 #endif /* CONFIG_GENERIC_IRQ_IPI */
482 
483 		err = irq_domain_set_hwirq_and_chip(d, virq, hwirq,
484 						    &gic_level_irq_controller,
485 						    NULL);
486 		if (err)
487 			return err;
488 
489 		irqd_set_single_target(irq_desc_get_irq_data(irq_to_desc(virq)));
490 		return gic_shared_irq_domain_map(d, virq, hwirq, 0);
491 	}
492 
493 	intr = GIC_HWIRQ_TO_LOCAL(hwirq);
494 	map = GIC_MAP_PIN_MAP_TO_PIN | gic_cpu_pin;
495 
496 	/*
497 	 * If adding support for more per-cpu interrupts, keep the the
498 	 * array in gic_all_vpes_irq_cpu_online() in sync.
499 	 */
500 	switch (intr) {
501 	case GIC_LOCAL_INT_TIMER:
502 		/* CONFIG_MIPS_CMP workaround (see __gic_init) */
503 		map = GIC_MAP_PIN_MAP_TO_PIN | timer_cpu_pin;
504 		fallthrough;
505 	case GIC_LOCAL_INT_PERFCTR:
506 	case GIC_LOCAL_INT_FDC:
507 		/*
508 		 * HACK: These are all really percpu interrupts, but
509 		 * the rest of the MIPS kernel code does not use the
510 		 * percpu IRQ API for them.
511 		 */
512 		cd = &gic_all_vpes_chip_data[intr];
513 		cd->map = map;
514 		err = irq_domain_set_hwirq_and_chip(d, virq, hwirq,
515 						    &gic_all_vpes_local_irq_controller,
516 						    cd);
517 		if (err)
518 			return err;
519 
520 		irq_set_handler(virq, handle_percpu_irq);
521 		break;
522 
523 	default:
524 		err = irq_domain_set_hwirq_and_chip(d, virq, hwirq,
525 						    &gic_local_irq_controller,
526 						    NULL);
527 		if (err)
528 			return err;
529 
530 		irq_set_handler(virq, handle_percpu_devid_irq);
531 		irq_set_percpu_devid(virq);
532 		break;
533 	}
534 
535 	if (!gic_local_irq_is_routable(intr))
536 		return -EPERM;
537 
538 	spin_lock_irqsave(&gic_lock, flags);
539 	for_each_online_cpu(cpu) {
540 		write_gic_vl_other(mips_cm_vp_id(cpu));
541 		write_gic_vo_map(mips_gic_vx_map_reg(intr), map);
542 	}
543 	spin_unlock_irqrestore(&gic_lock, flags);
544 
545 	return 0;
546 }
547 
548 static int gic_irq_domain_alloc(struct irq_domain *d, unsigned int virq,
549 				unsigned int nr_irqs, void *arg)
550 {
551 	struct irq_fwspec *fwspec = arg;
552 	irq_hw_number_t hwirq;
553 
554 	if (fwspec->param[0] == GIC_SHARED)
555 		hwirq = GIC_SHARED_TO_HWIRQ(fwspec->param[1]);
556 	else
557 		hwirq = GIC_LOCAL_TO_HWIRQ(fwspec->param[1]);
558 
559 	return gic_irq_domain_map(d, virq, hwirq);
560 }
561 
562 void gic_irq_domain_free(struct irq_domain *d, unsigned int virq,
563 			 unsigned int nr_irqs)
564 {
565 }
566 
567 static const struct irq_domain_ops gic_irq_domain_ops = {
568 	.xlate = gic_irq_domain_xlate,
569 	.alloc = gic_irq_domain_alloc,
570 	.free = gic_irq_domain_free,
571 	.map = gic_irq_domain_map,
572 };
573 
574 #ifdef CONFIG_GENERIC_IRQ_IPI
575 
576 static int gic_ipi_domain_xlate(struct irq_domain *d, struct device_node *ctrlr,
577 				const u32 *intspec, unsigned int intsize,
578 				irq_hw_number_t *out_hwirq,
579 				unsigned int *out_type)
580 {
581 	/*
582 	 * There's nothing to translate here. hwirq is dynamically allocated and
583 	 * the irq type is always edge triggered.
584 	 * */
585 	*out_hwirq = 0;
586 	*out_type = IRQ_TYPE_EDGE_RISING;
587 
588 	return 0;
589 }
590 
591 static int gic_ipi_domain_alloc(struct irq_domain *d, unsigned int virq,
592 				unsigned int nr_irqs, void *arg)
593 {
594 	struct cpumask *ipimask = arg;
595 	irq_hw_number_t hwirq, base_hwirq;
596 	int cpu, ret, i;
597 
598 	base_hwirq = find_first_bit(ipi_available, gic_shared_intrs);
599 	if (base_hwirq == gic_shared_intrs)
600 		return -ENOMEM;
601 
602 	/* check that we have enough space */
603 	for (i = base_hwirq; i < nr_irqs; i++) {
604 		if (!test_bit(i, ipi_available))
605 			return -EBUSY;
606 	}
607 	bitmap_clear(ipi_available, base_hwirq, nr_irqs);
608 
609 	/* map the hwirq for each cpu consecutively */
610 	i = 0;
611 	for_each_cpu(cpu, ipimask) {
612 		hwirq = GIC_SHARED_TO_HWIRQ(base_hwirq + i);
613 
614 		ret = irq_domain_set_hwirq_and_chip(d, virq + i, hwirq,
615 						    &gic_edge_irq_controller,
616 						    NULL);
617 		if (ret)
618 			goto error;
619 
620 		ret = irq_domain_set_hwirq_and_chip(d->parent, virq + i, hwirq,
621 						    &gic_edge_irq_controller,
622 						    NULL);
623 		if (ret)
624 			goto error;
625 
626 		ret = irq_set_irq_type(virq + i, IRQ_TYPE_EDGE_RISING);
627 		if (ret)
628 			goto error;
629 
630 		ret = gic_shared_irq_domain_map(d, virq + i, hwirq, cpu);
631 		if (ret)
632 			goto error;
633 
634 		i++;
635 	}
636 
637 	return 0;
638 error:
639 	bitmap_set(ipi_available, base_hwirq, nr_irqs);
640 	return ret;
641 }
642 
643 static void gic_ipi_domain_free(struct irq_domain *d, unsigned int virq,
644 				unsigned int nr_irqs)
645 {
646 	irq_hw_number_t base_hwirq;
647 	struct irq_data *data;
648 
649 	data = irq_get_irq_data(virq);
650 	if (!data)
651 		return;
652 
653 	base_hwirq = GIC_HWIRQ_TO_SHARED(irqd_to_hwirq(data));
654 	bitmap_set(ipi_available, base_hwirq, nr_irqs);
655 }
656 
657 static int gic_ipi_domain_match(struct irq_domain *d, struct device_node *node,
658 				enum irq_domain_bus_token bus_token)
659 {
660 	bool is_ipi;
661 
662 	switch (bus_token) {
663 	case DOMAIN_BUS_IPI:
664 		is_ipi = d->bus_token == bus_token;
665 		return (!node || to_of_node(d->fwnode) == node) && is_ipi;
666 		break;
667 	default:
668 		return 0;
669 	}
670 }
671 
672 static const struct irq_domain_ops gic_ipi_domain_ops = {
673 	.xlate = gic_ipi_domain_xlate,
674 	.alloc = gic_ipi_domain_alloc,
675 	.free = gic_ipi_domain_free,
676 	.match = gic_ipi_domain_match,
677 };
678 
679 static int gic_register_ipi_domain(struct device_node *node)
680 {
681 	struct irq_domain *gic_ipi_domain;
682 	unsigned int v[2], num_ipis;
683 
684 	gic_ipi_domain = irq_domain_add_hierarchy(gic_irq_domain,
685 						  IRQ_DOMAIN_FLAG_IPI_PER_CPU,
686 						  GIC_NUM_LOCAL_INTRS + gic_shared_intrs,
687 						  node, &gic_ipi_domain_ops, NULL);
688 	if (!gic_ipi_domain) {
689 		pr_err("Failed to add IPI domain");
690 		return -ENXIO;
691 	}
692 
693 	irq_domain_update_bus_token(gic_ipi_domain, DOMAIN_BUS_IPI);
694 
695 	if (node &&
696 	    !of_property_read_u32_array(node, "mti,reserved-ipi-vectors", v, 2)) {
697 		bitmap_set(ipi_resrv, v[0], v[1]);
698 	} else {
699 		/*
700 		 * Reserve 2 interrupts per possible CPU/VP for use as IPIs,
701 		 * meeting the requirements of arch/mips SMP.
702 		 */
703 		num_ipis = 2 * num_possible_cpus();
704 		bitmap_set(ipi_resrv, gic_shared_intrs - num_ipis, num_ipis);
705 	}
706 
707 	bitmap_copy(ipi_available, ipi_resrv, GIC_MAX_INTRS);
708 
709 	return 0;
710 }
711 
712 #else /* !CONFIG_GENERIC_IRQ_IPI */
713 
714 static inline int gic_register_ipi_domain(struct device_node *node)
715 {
716 	return 0;
717 }
718 
719 #endif /* !CONFIG_GENERIC_IRQ_IPI */
720 
721 static int gic_cpu_startup(unsigned int cpu)
722 {
723 	/* Enable or disable EIC */
724 	change_gic_vl_ctl(GIC_VX_CTL_EIC,
725 			  cpu_has_veic ? GIC_VX_CTL_EIC : 0);
726 
727 	/* Clear all local IRQ masks (ie. disable all local interrupts) */
728 	write_gic_vl_rmask(~0);
729 
730 	/* Enable desired interrupts */
731 	gic_all_vpes_irq_cpu_online();
732 
733 	return 0;
734 }
735 
736 static int __init gic_of_init(struct device_node *node,
737 			      struct device_node *parent)
738 {
739 	unsigned int cpu_vec, i, gicconfig;
740 	unsigned long reserved;
741 	phys_addr_t gic_base;
742 	struct resource res;
743 	size_t gic_len;
744 	int ret;
745 
746 	/* Find the first available CPU vector. */
747 	i = 0;
748 	reserved = (C_SW0 | C_SW1) >> __ffs(C_SW0);
749 	while (!of_property_read_u32_index(node, "mti,reserved-cpu-vectors",
750 					   i++, &cpu_vec))
751 		reserved |= BIT(cpu_vec);
752 
753 	cpu_vec = find_first_zero_bit(&reserved, hweight_long(ST0_IM));
754 	if (cpu_vec == hweight_long(ST0_IM)) {
755 		pr_err("No CPU vectors available\n");
756 		return -ENODEV;
757 	}
758 
759 	if (of_address_to_resource(node, 0, &res)) {
760 		/*
761 		 * Probe the CM for the GIC base address if not specified
762 		 * in the device-tree.
763 		 */
764 		if (mips_cm_present()) {
765 			gic_base = read_gcr_gic_base() &
766 				~CM_GCR_GIC_BASE_GICEN;
767 			gic_len = 0x20000;
768 			pr_warn("Using inherited base address %pa\n",
769 				&gic_base);
770 		} else {
771 			pr_err("Failed to get memory range\n");
772 			return -ENODEV;
773 		}
774 	} else {
775 		gic_base = res.start;
776 		gic_len = resource_size(&res);
777 	}
778 
779 	if (mips_cm_present()) {
780 		write_gcr_gic_base(gic_base | CM_GCR_GIC_BASE_GICEN);
781 		/* Ensure GIC region is enabled before trying to access it */
782 		__sync();
783 	}
784 
785 	mips_gic_base = ioremap(gic_base, gic_len);
786 	if (!mips_gic_base) {
787 		pr_err("Failed to ioremap gic_base\n");
788 		return -ENOMEM;
789 	}
790 
791 	gicconfig = read_gic_config();
792 	gic_shared_intrs = FIELD_GET(GIC_CONFIG_NUMINTERRUPTS, gicconfig);
793 	gic_shared_intrs = (gic_shared_intrs + 1) * 8;
794 
795 	if (cpu_has_veic) {
796 		/* Always use vector 1 in EIC mode */
797 		gic_cpu_pin = 0;
798 		timer_cpu_pin = gic_cpu_pin;
799 		set_vi_handler(gic_cpu_pin + GIC_PIN_TO_VEC_OFFSET,
800 			       __gic_irq_dispatch);
801 	} else {
802 		gic_cpu_pin = cpu_vec - GIC_CPU_PIN_OFFSET;
803 		irq_set_chained_handler(MIPS_CPU_IRQ_BASE + cpu_vec,
804 					gic_irq_dispatch);
805 		/*
806 		 * With the CMP implementation of SMP (deprecated), other CPUs
807 		 * are started by the bootloader and put into a timer based
808 		 * waiting poll loop. We must not re-route those CPU's local
809 		 * timer interrupts as the wait instruction will never finish,
810 		 * so just handle whatever CPU interrupt it is routed to by
811 		 * default.
812 		 *
813 		 * This workaround should be removed when CMP support is
814 		 * dropped.
815 		 */
816 		if (IS_ENABLED(CONFIG_MIPS_CMP) &&
817 		    gic_local_irq_is_routable(GIC_LOCAL_INT_TIMER)) {
818 			timer_cpu_pin = read_gic_vl_timer_map() & GIC_MAP_PIN_MAP;
819 			irq_set_chained_handler(MIPS_CPU_IRQ_BASE +
820 						GIC_CPU_PIN_OFFSET +
821 						timer_cpu_pin,
822 						gic_irq_dispatch);
823 		} else {
824 			timer_cpu_pin = gic_cpu_pin;
825 		}
826 	}
827 
828 	gic_irq_domain = irq_domain_add_simple(node, GIC_NUM_LOCAL_INTRS +
829 					       gic_shared_intrs, 0,
830 					       &gic_irq_domain_ops, NULL);
831 	if (!gic_irq_domain) {
832 		pr_err("Failed to add IRQ domain");
833 		return -ENXIO;
834 	}
835 
836 	ret = gic_register_ipi_domain(node);
837 	if (ret)
838 		return ret;
839 
840 	board_bind_eic_interrupt = &gic_bind_eic_interrupt;
841 
842 	/* Setup defaults */
843 	for (i = 0; i < gic_shared_intrs; i++) {
844 		change_gic_pol(i, GIC_POL_ACTIVE_HIGH);
845 		change_gic_trig(i, GIC_TRIG_LEVEL);
846 		write_gic_rmask(i);
847 	}
848 
849 	return cpuhp_setup_state(CPUHP_AP_IRQ_MIPS_GIC_STARTING,
850 				 "irqchip/mips/gic:starting",
851 				 gic_cpu_startup, NULL);
852 }
853 IRQCHIP_DECLARE(mips_gic, "mti,gic", gic_of_init);
854