summaryrefslogtreecommitdiff
path: root/drivers/irqchip/irq-gic-v3.c
blob: 1a146ccee7017d4b344763c5f5d2cf45af1d9e4f (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
/*
 * Copyright (C) 2013, 2014 ARM Limited, All Rights Reserved.
 * Author: Marc Zyngier <marc.zyngier@arm.com>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */

#include <linux/cpu.h>
#include <linux/cpu_pm.h>
#include <linux/delay.h>
#include <linux/interrupt.h>
#include <linux/of.h>
#include <linux/of_address.h>
#include <linux/of_irq.h>
#include <linux/percpu.h>
#include <linux/slab.h>

#include <linux/irqchip/arm-gic-v3.h>

#include <asm/cputype.h>
#include <asm/exception.h>
#include <asm/smp_plat.h>

#include "irq-gic-common.h"
#include "irqchip.h"

struct redist_region {
	void __iomem		*redist_base;
	phys_addr_t		phys_base;
};

struct gic_chip_data {
	void __iomem		*dist_base;
	struct redist_region	*redist_regions;
	struct rdists		rdists;
	struct irq_domain	*domain;
	u64			redist_stride;
	u32			nr_redist_regions;
	unsigned int		irq_nr;
};

static struct gic_chip_data gic_data __read_mostly;

#define gic_data_rdist()		(this_cpu_ptr(gic_data.rdists.rdist))
#define gic_data_rdist_rd_base()	(gic_data_rdist()->rd_base)
#define gic_data_rdist_sgi_base()	(gic_data_rdist_rd_base() + SZ_64K)

/* Our default, arbitrary priority value. Linux only uses one anyway. */
#define DEFAULT_PMR_VALUE	0xf0

static inline unsigned int gic_irq(struct irq_data *d)
{
	return d->hwirq;
}

static inline int gic_irq_in_rdist(struct irq_data *d)
{
	return gic_irq(d) < 32;
}

static inline void __iomem *gic_dist_base(struct irq_data *d)
{
	if (gic_irq_in_rdist(d))	/* SGI+PPI -> SGI_base for this CPU */
		return gic_data_rdist_sgi_base();

	if (d->hwirq <= 1023)		/* SPI -> dist_base */
		return gic_data.dist_base;

	return NULL;
}

static void gic_do_wait_for_rwp(void __iomem *base)
{
	u32 count = 1000000;	/* 1s! */

	while (readl_relaxed(base + GICD_CTLR) & GICD_CTLR_RWP) {
		count--;
		if (!count) {
			pr_err_ratelimited("RWP timeout, gone fishing\n");
			return;
		}
		cpu_relax();
		udelay(1);
	};
}

/* Wait for completion of a distributor change */
static void gic_dist_wait_for_rwp(void)
{
	gic_do_wait_for_rwp(gic_data.dist_base);
}

/* Wait for completion of a redistributor change */
static void gic_redist_wait_for_rwp(void)
{
	gic_do_wait_for_rwp(gic_data_rdist_rd_base());
}

/* Low level accessors */
static u64 __maybe_unused gic_read_iar(void)
{
	u64 irqstat;

	asm volatile("mrs_s %0, " __stringify(ICC_IAR1_EL1) : "=r" (irqstat));
	return irqstat;
}

static void __maybe_unused gic_write_pmr(u64 val)
{
	asm volatile("msr_s " __stringify(ICC_PMR_EL1) ", %0" : : "r" (val));
}

static void __maybe_unused gic_write_ctlr(u64 val)
{
	asm volatile("msr_s " __stringify(ICC_CTLR_EL1) ", %0" : : "r" (val));
	isb();
}

static void __maybe_unused gic_write_grpen1(u64 val)
{
	asm volatile("msr_s " __stringify(ICC_GRPEN1_EL1) ", %0" : : "r" (val));
	isb();
}

static void __maybe_unused gic_write_sgi1r(u64 val)
{
	asm volatile("msr_s " __stringify(ICC_SGI1R_EL1) ", %0" : : "r" (val));
}

static void gic_enable_sre(void)
{
	u64 val;

	asm volatile("mrs_s %0, " __stringify(ICC_SRE_EL1) : "=r" (val));
	val |= ICC_SRE_EL1_SRE;
	asm volatile("msr_s " __stringify(ICC_SRE_EL1) ", %0" : : "r" (val));
	isb();

	/*
	 * Need to check that the SRE bit has actually been set. If
	 * not, it means that SRE is disabled at EL2. We're going to
	 * die painfully, and there is nothing we can do about it.
	 *
	 * Kindly inform the luser.
	 */
	asm volatile("mrs_s %0, " __stringify(ICC_SRE_EL1) : "=r" (val));
	if (!(val & ICC_SRE_EL1_SRE))
		pr_err("GIC: unable to set SRE (disabled at EL2), panic ahead\n");
}

static void gic_enable_redist(bool enable)
{
	void __iomem *rbase;
	u32 count = 1000000;	/* 1s! */
	u32 val;

	rbase = gic_data_rdist_rd_base();

	val = readl_relaxed(rbase + GICR_WAKER);
	if (enable)
		/* Wake up this CPU redistributor */
		val &= ~GICR_WAKER_ProcessorSleep;
	else
		val |= GICR_WAKER_ProcessorSleep;
	writel_relaxed(val, rbase + GICR_WAKER);

	if (!enable) {		/* Check that GICR_WAKER is writeable */
		val = readl_relaxed(rbase + GICR_WAKER);
		if (!(val & GICR_WAKER_ProcessorSleep))
			return;	/* No PM support in this redistributor */
	}

	while (count--) {
		val = readl_relaxed(rbase + GICR_WAKER);
		if (enable ^ (val & GICR_WAKER_ChildrenAsleep))
			break;
		cpu_relax();
		udelay(1);
	};
	if (!count)
		pr_err_ratelimited("redistributor failed to %s...\n",
				   enable ? "wakeup" : "sleep");
}

/*
 * Routines to disable, enable, EOI and route interrupts
 */
static void gic_poke_irq(struct irq_data *d, u32 offset)
{
	u32 mask = 1 << (gic_irq(d) % 32);
	void (*rwp_wait)(void);
	void __iomem *base;

	if (gic_irq_in_rdist(d)) {
		base = gic_data_rdist_sgi_base();
		rwp_wait = gic_redist_wait_for_rwp;
	} else {
		base = gic_data.dist_base;
		rwp_wait = gic_dist_wait_for_rwp;
	}

	writel_relaxed(mask, base + offset + (gic_irq(d) / 32) * 4);
	rwp_wait();
}

static void gic_mask_irq(struct irq_data *d)
{
	gic_poke_irq(d, GICD_ICENABLER);
}

static void gic_unmask_irq(struct irq_data *d)
{
	gic_poke_irq(d, GICD_ISENABLER);
}

static void gic_eoi_irq(struct irq_data *d)
{
	gic_write_eoir(gic_irq(d));
}

static int gic_set_type(struct irq_data *d, unsigned int type)
{
	unsigned int irq = gic_irq(d);
	void (*rwp_wait)(void);
	void __iomem *base;

	/* Interrupt configuration for SGIs can't be changed */
	if (irq < 16)
		return -EINVAL;

	if (type != IRQ_TYPE_LEVEL_HIGH && type != IRQ_TYPE_EDGE_RISING)
		return -EINVAL;

	if (gic_irq_in_rdist(d)) {
		base = gic_data_rdist_sgi_base();
		rwp_wait = gic_redist_wait_for_rwp;
	} else {
		base = gic_data.dist_base;
		rwp_wait = gic_dist_wait_for_rwp;
	}

	gic_configure_irq(irq, type, base, rwp_wait);

	return 0;
}

static u64 gic_mpidr_to_affinity(u64 mpidr)
{
	u64 aff;

	aff = (MPIDR_AFFINITY_LEVEL(mpidr, 3) << 32 |
	       MPIDR_AFFINITY_LEVEL(mpidr, 2) << 16 |
	       MPIDR_AFFINITY_LEVEL(mpidr, 1) << 8  |
	       MPIDR_AFFINITY_LEVEL(mpidr, 0));

	return aff;
}

static asmlinkage void __exception_irq_entry gic_handle_irq(struct pt_regs *regs)
{
	u64 irqnr;

	do {
		irqnr = gic_read_iar();

		if (likely(irqnr > 15 && irqnr < 1020) || irqnr >= 8192) {
			int err;
			err = handle_domain_irq(gic_data.domain, irqnr, regs);
			if (err) {
				WARN_ONCE(true, "Unexpected interrupt received!\n");
				gic_write_eoir(irqnr);
			}
			continue;
		}
		if (irqnr < 16) {
			gic_write_eoir(irqnr);
#ifdef CONFIG_SMP
			handle_IPI(irqnr, regs);
#else
			WARN_ONCE(true, "Unexpected SGI received!\n");
#endif
			continue;
		}
	} while (irqnr != ICC_IAR1_EL1_SPURIOUS);
}

static void __init gic_dist_init(void)
{
	unsigned int i;
	u64 affinity;
	void __iomem *base = gic_data.dist_base;

	/* Disable the distributor */
	writel_relaxed(0, base + GICD_CTLR);
	gic_dist_wait_for_rwp();

	gic_dist_config(base, gic_data.irq_nr, gic_dist_wait_for_rwp);

	/* Enable distributor with ARE, Group1 */
	writel_relaxed(GICD_CTLR_ARE_NS | GICD_CTLR_ENABLE_G1A | GICD_CTLR_ENABLE_G1,
		       base + GICD_CTLR);

	/*
	 * Set all global interrupts to the boot CPU only. ARE must be
	 * enabled.
	 */
	affinity = gic_mpidr_to_affinity(cpu_logical_map(smp_processor_id()));
	for (i = 32; i < gic_data.irq_nr; i++)
		writeq_relaxed(affinity, base + GICD_IROUTER + i * 8);
}

static int gic_populate_rdist(void)
{
	u64 mpidr = cpu_logical_map(smp_processor_id());
	u64 typer;
	u32 aff;
	int i;

	/*
	 * Convert affinity to a 32bit value that can be matched to
	 * GICR_TYPER bits [63:32].
	 */
	aff = (MPIDR_AFFINITY_LEVEL(mpidr, 3) << 24 |
	       MPIDR_AFFINITY_LEVEL(mpidr, 2) << 16 |
	       MPIDR_AFFINITY_LEVEL(mpidr, 1) << 8 |
	       MPIDR_AFFINITY_LEVEL(mpidr, 0));

	for (i = 0; i < gic_data.nr_redist_regions; i++) {
		void __iomem *ptr = gic_data.redist_regions[i].redist_base;
		u32 reg;

		reg = readl_relaxed(ptr + GICR_PIDR2) & GIC_PIDR2_ARCH_MASK;
		if (reg != GIC_PIDR2_ARCH_GICv3 &&
		    reg != GIC_PIDR2_ARCH_GICv4) { /* We're in trouble... */
			pr_warn("No redistributor present @%p\n", ptr);
			break;
		}

		do {
			typer = readq_relaxed(ptr + GICR_TYPER);
			if ((typer >> 32) == aff) {
				u64 offset = ptr - gic_data.redist_regions[i].redist_base;
				gic_data_rdist_rd_base() = ptr;
				gic_data_rdist()->phys_base = gic_data.redist_regions[i].phys_base + offset;
				pr_info("CPU%d: found redistributor %llx region %d:%pa\n",
					smp_processor_id(),
					(unsigned long long)mpidr,
					i, &gic_data_rdist()->phys_base);
				return 0;
			}

			if (gic_data.redist_stride) {
				ptr += gic_data.redist_stride;
			} else {
				ptr += SZ_64K * 2; /* Skip RD_base + SGI_base */
				if (typer & GICR_TYPER_VLPIS)
					ptr += SZ_64K * 2; /* Skip VLPI_base + reserved page */
			}
		} while (!(typer & GICR_TYPER_LAST));
	}

	/* We couldn't even deal with ourselves... */
	WARN(true, "CPU%d: mpidr %llx has no re-distributor!\n",
	     smp_processor_id(), (unsigned long long)mpidr);
	return -ENODEV;
}

static void gic_cpu_sys_reg_init(void)
{
	/* Enable system registers */
	gic_enable_sre();

	/* Set priority mask register */
	gic_write_pmr(DEFAULT_PMR_VALUE);

	/* EOI deactivates interrupt too (mode 0) */
	gic_write_ctlr(ICC_CTLR_EL1_EOImode_drop_dir);

	/* ... and let's hit the road... */
	gic_write_grpen1(1);
}

static int gic_dist_supports_lpis(void)
{
	return !!(readl_relaxed(gic_data.dist_base + GICD_TYPER) & GICD_TYPER_LPIS);
}

static void gic_cpu_init(void)
{
	void __iomem *rbase;

	/* Register ourselves with the rest of the world */
	if (gic_populate_rdist())
		return;

	gic_enable_redist(true);

	rbase = gic_data_rdist_sgi_base();

	gic_cpu_config(rbase, gic_redist_wait_for_rwp);

	/* Give LPIs a spin */
	if (IS_ENABLED(CONFIG_ARM_GIC_V3_ITS) && gic_dist_supports_lpis())
		its_cpu_init();

	/* initialise system registers */
	gic_cpu_sys_reg_init();
}

#ifdef CONFIG_SMP
static int gic_peek_irq(struct irq_data *d, u32 offset)
{
	u32 mask = 1 << (gic_irq(d) % 32);
	void __iomem *base;

	if (gic_irq_in_rdist(d))
		base = gic_data_rdist_sgi_base();
	else
		base = gic_data.dist_base;

	return !!(readl_relaxed(base + offset + (gic_irq(d) / 32) * 4) & mask);
}

static int gic_secondary_init(struct notifier_block *nfb,
			      unsigned long action, void *hcpu)
{
	if (action == CPU_STARTING || action == CPU_STARTING_FROZEN)
		gic_cpu_init();
	return NOTIFY_OK;
}

/*
 * Notifier for enabling the GIC CPU interface. Set an arbitrarily high
 * priority because the GIC needs to be up before the ARM generic timers.
 */
static struct notifier_block gic_cpu_notifier = {
	.notifier_call = gic_secondary_init,
	.priority = 100,
};

static u16 gic_compute_target_list(int *base_cpu, const struct cpumask *mask,
				   u64 cluster_id)
{
	int cpu = *base_cpu;
	u64 mpidr = cpu_logical_map(cpu);
	u16 tlist = 0;

	while (cpu < nr_cpu_ids) {
		/*
		 * If we ever get a cluster of more than 16 CPUs, just
		 * scream and skip that CPU.
		 */
		if (WARN_ON((mpidr & 0xff) >= 16))
			goto out;

		tlist |= 1 << (mpidr & 0xf);

		cpu = cpumask_next(cpu, mask);
		if (cpu == nr_cpu_ids)
			goto out;

		mpidr = cpu_logical_map(cpu);

		if (cluster_id != (mpidr & ~0xffUL)) {
			cpu--;
			goto out;
		}
	}
out:
	*base_cpu = cpu;
	return tlist;
}

static void gic_send_sgi(u64 cluster_id, u16 tlist, unsigned int irq)
{
	u64 val;

	val = (MPIDR_AFFINITY_LEVEL(cluster_id, 3) << 48	|
	       MPIDR_AFFINITY_LEVEL(cluster_id, 2) << 32	|
	       irq << 24			    		|
	       MPIDR_AFFINITY_LEVEL(cluster_id, 1) << 16	|
	       tlist);

	pr_debug("CPU%d: ICC_SGI1R_EL1 %llx\n", smp_processor_id(), val);
	gic_write_sgi1r(val);
}

static void gic_raise_softirq(const struct cpumask *mask, unsigned int irq)
{
	int cpu;

	if (WARN_ON(irq >= 16))
		return;

	/*
	 * Ensure that stores to Normal memory are visible to the
	 * other CPUs before issuing the IPI.
	 */
	smp_wmb();

	for_each_cpu_mask(cpu, *mask) {
		u64 cluster_id = cpu_logical_map(cpu) & ~0xffUL;
		u16 tlist;

		tlist = gic_compute_target_list(&cpu, mask, cluster_id);
		gic_send_sgi(cluster_id, tlist, irq);
	}

	/* Force the above writes to ICC_SGI1R_EL1 to be executed */
	isb();
}

static void gic_smp_init(void)
{
	set_smp_cross_call(gic_raise_softirq);
	register_cpu_notifier(&gic_cpu_notifier);
}

static int gic_set_affinity(struct irq_data *d, const struct cpumask *mask_val,
			    bool force)
{
	unsigned int cpu = cpumask_any_and(mask_val, cpu_online_mask);
	void __iomem *reg;
	int enabled;
	u64 val;

	if (gic_irq_in_rdist(d))
		return -EINVAL;

	/* If interrupt was enabled, disable it first */
	enabled = gic_peek_irq(d, GICD_ISENABLER);
	if (enabled)
		gic_mask_irq(d);

	reg = gic_dist_base(d) + GICD_IROUTER + (gic_irq(d) * 8);
	val = gic_mpidr_to_affinity(cpu_logical_map(cpu));

	writeq_relaxed(val, reg);

	/*
	 * If the interrupt was enabled, enabled it again. Otherwise,
	 * just wait for the distributor to have digested our changes.
	 */
	if (enabled)
		gic_unmask_irq(d);
	else
		gic_dist_wait_for_rwp();

	return IRQ_SET_MASK_OK;
}
#else
#define gic_set_affinity	NULL
#define gic_smp_init()		do { } while(0)
#endif

#ifdef CONFIG_CPU_PM
static int gic_cpu_pm_notifier(struct notifier_block *self,
			       unsigned long cmd, void *v)
{
	if (cmd == CPU_PM_EXIT) {
		gic_enable_redist(true);
		gic_cpu_sys_reg_init();
	} else if (cmd == CPU_PM_ENTER) {
		gic_write_grpen1(0);
		gic_enable_redist(false);
	}
	return NOTIFY_OK;
}

static struct notifier_block gic_cpu_pm_notifier_block = {
	.notifier_call = gic_cpu_pm_notifier,
};

static void gic_cpu_pm_init(void)
{
	cpu_pm_register_notifier(&gic_cpu_pm_notifier_block);
}

#else
static inline void gic_cpu_pm_init(void) { }
#endif /* CONFIG_CPU_PM */

static struct irq_chip gic_chip = {
	.name			= "GICv3",
	.irq_mask		= gic_mask_irq,
	.irq_unmask		= gic_unmask_irq,
	.irq_eoi		= gic_eoi_irq,
	.irq_set_type		= gic_set_type,
	.irq_set_affinity	= gic_set_affinity,
};

#define GIC_ID_NR		(1U << gic_data.rdists.id_bits)

static int gic_irq_domain_map(struct irq_domain *d, unsigned int irq,
			      irq_hw_number_t hw)
{
	/* SGIs are private to the core kernel */
	if (hw < 16)
		return -EPERM;
	/* Nothing here */
	if (hw >= gic_data.irq_nr && hw < 8192)
		return -EPERM;
	/* Off limits */
	if (hw >= GIC_ID_NR)
		return -EPERM;

	/* PPIs */
	if (hw < 32) {
		irq_set_percpu_devid(irq);
		irq_domain_set_info(d, irq, hw, &gic_chip, d->host_data,
				    handle_percpu_devid_irq, NULL, NULL);
		set_irq_flags(irq, IRQF_VALID | IRQF_NOAUTOEN);
	}
	/* SPIs */
	if (hw >= 32 && hw < gic_data.irq_nr) {
		irq_domain_set_info(d, irq, hw, &gic_chip, d->host_data,
				    handle_fasteoi_irq, NULL, NULL);
		set_irq_flags(irq, IRQF_VALID | IRQF_PROBE);
	}
	/* LPIs */
	if (hw >= 8192 && hw < GIC_ID_NR) {
		if (!gic_dist_supports_lpis())
			return -EPERM;
		irq_domain_set_info(d, irq, hw, &gic_chip, d->host_data,
				    handle_fasteoi_irq, NULL, NULL);
		set_irq_flags(irq, IRQF_VALID);
	}

	return 0;
}

static int gic_irq_domain_xlate(struct irq_domain *d,
				struct device_node *controller,
				const u32 *intspec, unsigned int intsize,
				unsigned long *out_hwirq, unsigned int *out_type)
{
	if (d->of_node != controller)
		return -EINVAL;
	if (intsize < 3)
		return -EINVAL;

	switch(intspec[0]) {
	case 0:			/* SPI */
		*out_hwirq = intspec[1] + 32;
		break;
	case 1:			/* PPI */
		*out_hwirq = intspec[1] + 16;
		break;
	case GIC_IRQ_TYPE_LPI:	/* LPI */
		*out_hwirq = intspec[1];
		break;
	default:
		return -EINVAL;
	}

	*out_type = intspec[2] & IRQ_TYPE_SENSE_MASK;
	return 0;
}

static int gic_irq_domain_alloc(struct irq_domain *domain, unsigned int virq,
				unsigned int nr_irqs, void *arg)
{
	int i, ret;
	irq_hw_number_t hwirq;
	unsigned int type = IRQ_TYPE_NONE;
	struct of_phandle_args *irq_data = arg;

	ret = gic_irq_domain_xlate(domain, irq_data->np, irq_data->args,
				   irq_data->args_count, &hwirq, &type);
	if (ret)
		return ret;

	for (i = 0; i < nr_irqs; i++)
		gic_irq_domain_map(domain, virq + i, hwirq + i);

	return 0;
}

static void gic_irq_domain_free(struct irq_domain *domain, unsigned int virq,
				unsigned int nr_irqs)
{
	int i;

	for (i = 0; i < nr_irqs; i++) {
		struct irq_data *d = irq_domain_get_irq_data(domain, virq + i);
		irq_set_handler(virq + i, NULL);
		irq_domain_reset_irq_data(d);
	}
}

static const struct irq_domain_ops gic_irq_domain_ops = {
	.xlate = gic_irq_domain_xlate,
	.alloc = gic_irq_domain_alloc,
	.free = gic_irq_domain_free,
};

static int __init gic_of_init(struct device_node *node, struct device_node *parent)
{
	void __iomem *dist_base;
	struct redist_region *rdist_regs;
	u64 redist_stride;
	u32 nr_redist_regions;
	u32 typer;
	u32 reg;
	int gic_irqs;
	int err;
	int i;

	dist_base = of_iomap(node, 0);
	if (!dist_base) {
		pr_err("%s: unable to map gic dist registers\n",
			node->full_name);
		return -ENXIO;
	}

	reg = readl_relaxed(dist_base + GICD_PIDR2) & GIC_PIDR2_ARCH_MASK;
	if (reg != GIC_PIDR2_ARCH_GICv3 && reg != GIC_PIDR2_ARCH_GICv4) {
		pr_err("%s: no distributor detected, giving up\n",
			node->full_name);
		err = -ENODEV;
		goto out_unmap_dist;
	}

	if (of_property_read_u32(node, "#redistributor-regions", &nr_redist_regions))
		nr_redist_regions = 1;

	rdist_regs = kzalloc(sizeof(*rdist_regs) * nr_redist_regions, GFP_KERNEL);
	if (!rdist_regs) {
		err = -ENOMEM;
		goto out_unmap_dist;
	}

	for (i = 0; i < nr_redist_regions; i++) {
		struct resource res;
		int ret;

		ret = of_address_to_resource(node, 1 + i, &res);
		rdist_regs[i].redist_base = of_iomap(node, 1 + i);
		if (ret || !rdist_regs[i].redist_base) {
			pr_err("%s: couldn't map region %d\n",
			       node->full_name, i);
			err = -ENODEV;
			goto out_unmap_rdist;
		}
		rdist_regs[i].phys_base = res.start;
	}

	if (of_property_read_u64(node, "redistributor-stride", &redist_stride))
		redist_stride = 0;

	gic_data.dist_base = dist_base;
	gic_data.redist_regions = rdist_regs;
	gic_data.nr_redist_regions = nr_redist_regions;
	gic_data.redist_stride = redist_stride;

	/*
	 * Find out how many interrupts are supported.
	 * The GIC only supports up to 1020 interrupt sources (SGI+PPI+SPI)
	 */
	typer = readl_relaxed(gic_data.dist_base + GICD_TYPER);
	gic_data.rdists.id_bits = GICD_TYPER_ID_BITS(typer);
	gic_irqs = GICD_TYPER_IRQS(typer);
	if (gic_irqs > 1020)
		gic_irqs = 1020;
	gic_data.irq_nr = gic_irqs;

	gic_data.domain = irq_domain_add_tree(node, &gic_irq_domain_ops,
					      &gic_data);
	gic_data.rdists.rdist = alloc_percpu(typeof(*gic_data.rdists.rdist));

	if (WARN_ON(!gic_data.domain) || WARN_ON(!gic_data.rdists.rdist)) {
		err = -ENOMEM;
		goto out_free;
	}

	set_handle_irq(gic_handle_irq);

	if (IS_ENABLED(CONFIG_ARM_GIC_V3_ITS) && gic_dist_supports_lpis())
		its_init(node, &gic_data.rdists, gic_data.domain);

	gic_smp_init();
	gic_dist_init();
	gic_cpu_init();
	gic_cpu_pm_init();

	return 0;

out_free:
	if (gic_data.domain)
		irq_domain_remove(gic_data.domain);
	free_percpu(gic_data.rdists.rdist);
out_unmap_rdist:
	for (i = 0; i < nr_redist_regions; i++)
		if (rdist_regs[i].redist_base)
			iounmap(rdist_regs[i].redist_base);
	kfree(rdist_regs);
out_unmap_dist:
	iounmap(dist_base);
	return err;
}

IRQCHIP_DECLARE(gic_v3, "arm,gic-v3", gic_of_init);