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