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