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