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1 /*
2  * Copyright (C) 2013, 2014 ARM Limited, All Rights Reserved.
3  * Author: Marc Zyngier <marc.zyngier@arm.com>
4  *
5  * This program is free software; you can redistribute it and/or modify
6  * it under the terms of the GNU General Public License version 2 as
7  * published by the Free Software Foundation.
8  *
9  * This program is distributed in the hope that it will be useful,
10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
12  * GNU General Public License for more details.
13  *
14  * You should have received a copy of the GNU General Public License
15  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
16  */
17 
18 #include <linux/cpu.h>
19 #include <linux/cpu_pm.h>
20 #include <linux/delay.h>
21 #include <linux/interrupt.h>
22 #include <linux/of.h>
23 #include <linux/of_address.h>
24 #include <linux/of_irq.h>
25 #include <linux/percpu.h>
26 #include <linux/slab.h>
27 
28 #include <linux/irqchip/arm-gic-v3.h>
29 
30 #include <asm/cputype.h>
31 #include <asm/exception.h>
32 #include <asm/smp_plat.h>
33 
34 #include "irq-gic-common.h"
35 #include "irqchip.h"
36 
37 struct gic_chip_data {
38 	void __iomem		*dist_base;
39 	void __iomem		**redist_base;
40 	void __iomem * __percpu	*rdist;
41 	struct irq_domain	*domain;
42 	u64			redist_stride;
43 	u32			redist_regions;
44 	unsigned int		irq_nr;
45 };
46 
47 static struct gic_chip_data gic_data __read_mostly;
48 
49 #define gic_data_rdist()		(this_cpu_ptr(gic_data.rdist))
50 #define gic_data_rdist_rd_base()	(*gic_data_rdist())
51 #define gic_data_rdist_sgi_base()	(gic_data_rdist_rd_base() + SZ_64K)
52 
53 /* Our default, arbitrary priority value. Linux only uses one anyway. */
54 #define DEFAULT_PMR_VALUE	0xf0
55 
gic_irq(struct irq_data * d)56 static inline unsigned int gic_irq(struct irq_data *d)
57 {
58 	return d->hwirq;
59 }
60 
gic_irq_in_rdist(struct irq_data * d)61 static inline int gic_irq_in_rdist(struct irq_data *d)
62 {
63 	return gic_irq(d) < 32;
64 }
65 
gic_dist_base(struct irq_data * d)66 static inline void __iomem *gic_dist_base(struct irq_data *d)
67 {
68 	if (gic_irq_in_rdist(d))	/* SGI+PPI -> SGI_base for this CPU */
69 		return gic_data_rdist_sgi_base();
70 
71 	if (d->hwirq <= 1023)		/* SPI -> dist_base */
72 		return gic_data.dist_base;
73 
74 	if (d->hwirq >= 8192)
75 		BUG();		/* LPI Detected!!! */
76 
77 	return NULL;
78 }
79 
gic_do_wait_for_rwp(void __iomem * base)80 static void gic_do_wait_for_rwp(void __iomem *base)
81 {
82 	u32 count = 1000000;	/* 1s! */
83 
84 	while (readl_relaxed(base + GICD_CTLR) & GICD_CTLR_RWP) {
85 		count--;
86 		if (!count) {
87 			pr_err_ratelimited("RWP timeout, gone fishing\n");
88 			return;
89 		}
90 		cpu_relax();
91 		udelay(1);
92 	};
93 }
94 
95 /* Wait for completion of a distributor change */
gic_dist_wait_for_rwp(void)96 static void gic_dist_wait_for_rwp(void)
97 {
98 	gic_do_wait_for_rwp(gic_data.dist_base);
99 }
100 
101 /* Wait for completion of a redistributor change */
gic_redist_wait_for_rwp(void)102 static void gic_redist_wait_for_rwp(void)
103 {
104 	gic_do_wait_for_rwp(gic_data_rdist_rd_base());
105 }
106 
107 /* Low level accessors */
gic_read_iar(void)108 static u64 __maybe_unused gic_read_iar(void)
109 {
110 	u64 irqstat;
111 
112 	asm volatile("mrs_s %0, " __stringify(ICC_IAR1_EL1) : "=r" (irqstat));
113 	return irqstat;
114 }
115 
gic_write_pmr(u64 val)116 static void __maybe_unused gic_write_pmr(u64 val)
117 {
118 	asm volatile("msr_s " __stringify(ICC_PMR_EL1) ", %0" : : "r" (val));
119 }
120 
gic_write_ctlr(u64 val)121 static void __maybe_unused gic_write_ctlr(u64 val)
122 {
123 	asm volatile("msr_s " __stringify(ICC_CTLR_EL1) ", %0" : : "r" (val));
124 	isb();
125 }
126 
gic_write_grpen1(u64 val)127 static void __maybe_unused gic_write_grpen1(u64 val)
128 {
129 	asm volatile("msr_s " __stringify(ICC_GRPEN1_EL1) ", %0" : : "r" (val));
130 	isb();
131 }
132 
gic_write_sgi1r(u64 val)133 static void __maybe_unused gic_write_sgi1r(u64 val)
134 {
135 	asm volatile("msr_s " __stringify(ICC_SGI1R_EL1) ", %0" : : "r" (val));
136 }
137 
gic_enable_sre(void)138 static void gic_enable_sre(void)
139 {
140 	u64 val;
141 
142 	asm volatile("mrs_s %0, " __stringify(ICC_SRE_EL1) : "=r" (val));
143 	val |= ICC_SRE_EL1_SRE;
144 	asm volatile("msr_s " __stringify(ICC_SRE_EL1) ", %0" : : "r" (val));
145 	isb();
146 
147 	/*
148 	 * Need to check that the SRE bit has actually been set. If
149 	 * not, it means that SRE is disabled at EL2. We're going to
150 	 * die painfully, and there is nothing we can do about it.
151 	 *
152 	 * Kindly inform the luser.
153 	 */
154 	asm volatile("mrs_s %0, " __stringify(ICC_SRE_EL1) : "=r" (val));
155 	if (!(val & ICC_SRE_EL1_SRE))
156 		pr_err("GIC: unable to set SRE (disabled at EL2), panic ahead\n");
157 }
158 
gic_enable_redist(bool enable)159 static void gic_enable_redist(bool enable)
160 {
161 	void __iomem *rbase;
162 	u32 count = 1000000;	/* 1s! */
163 	u32 val;
164 
165 	rbase = gic_data_rdist_rd_base();
166 
167 	val = readl_relaxed(rbase + GICR_WAKER);
168 	if (enable)
169 		/* Wake up this CPU redistributor */
170 		val &= ~GICR_WAKER_ProcessorSleep;
171 	else
172 		val |= GICR_WAKER_ProcessorSleep;
173 	writel_relaxed(val, rbase + GICR_WAKER);
174 
175 	if (!enable) {		/* Check that GICR_WAKER is writeable */
176 		val = readl_relaxed(rbase + GICR_WAKER);
177 		if (!(val & GICR_WAKER_ProcessorSleep))
178 			return;	/* No PM support in this redistributor */
179 	}
180 
181 	while (--count) {
182 		val = readl_relaxed(rbase + GICR_WAKER);
183 		if (enable ^ (val & GICR_WAKER_ChildrenAsleep))
184 			break;
185 		cpu_relax();
186 		udelay(1);
187 	};
188 	if (!count)
189 		pr_err_ratelimited("redistributor failed to %s...\n",
190 				   enable ? "wakeup" : "sleep");
191 }
192 
193 /*
194  * Routines to disable, enable, EOI and route interrupts
195  */
gic_poke_irq(struct irq_data * d,u32 offset)196 static void gic_poke_irq(struct irq_data *d, u32 offset)
197 {
198 	u32 mask = 1 << (gic_irq(d) % 32);
199 	void (*rwp_wait)(void);
200 	void __iomem *base;
201 
202 	if (gic_irq_in_rdist(d)) {
203 		base = gic_data_rdist_sgi_base();
204 		rwp_wait = gic_redist_wait_for_rwp;
205 	} else {
206 		base = gic_data.dist_base;
207 		rwp_wait = gic_dist_wait_for_rwp;
208 	}
209 
210 	writel_relaxed(mask, base + offset + (gic_irq(d) / 32) * 4);
211 	rwp_wait();
212 }
213 
gic_mask_irq(struct irq_data * d)214 static void gic_mask_irq(struct irq_data *d)
215 {
216 	gic_poke_irq(d, GICD_ICENABLER);
217 }
218 
gic_unmask_irq(struct irq_data * d)219 static void gic_unmask_irq(struct irq_data *d)
220 {
221 	gic_poke_irq(d, GICD_ISENABLER);
222 }
223 
gic_eoi_irq(struct irq_data * d)224 static void gic_eoi_irq(struct irq_data *d)
225 {
226 	gic_write_eoir(gic_irq(d));
227 }
228 
gic_set_type(struct irq_data * d,unsigned int type)229 static int gic_set_type(struct irq_data *d, unsigned int type)
230 {
231 	unsigned int irq = gic_irq(d);
232 	void (*rwp_wait)(void);
233 	void __iomem *base;
234 
235 	/* Interrupt configuration for SGIs can't be changed */
236 	if (irq < 16)
237 		return -EINVAL;
238 
239 	if (type != IRQ_TYPE_LEVEL_HIGH && type != IRQ_TYPE_EDGE_RISING)
240 		return -EINVAL;
241 
242 	if (gic_irq_in_rdist(d)) {
243 		base = gic_data_rdist_sgi_base();
244 		rwp_wait = gic_redist_wait_for_rwp;
245 	} else {
246 		base = gic_data.dist_base;
247 		rwp_wait = gic_dist_wait_for_rwp;
248 	}
249 
250 	gic_configure_irq(irq, type, base, rwp_wait);
251 
252 	return 0;
253 }
254 
gic_mpidr_to_affinity(u64 mpidr)255 static u64 gic_mpidr_to_affinity(u64 mpidr)
256 {
257 	u64 aff;
258 
259 	aff = (MPIDR_AFFINITY_LEVEL(mpidr, 3) << 32 |
260 	       MPIDR_AFFINITY_LEVEL(mpidr, 2) << 16 |
261 	       MPIDR_AFFINITY_LEVEL(mpidr, 1) << 8  |
262 	       MPIDR_AFFINITY_LEVEL(mpidr, 0));
263 
264 	return aff;
265 }
266 
gic_handle_irq(struct pt_regs * regs)267 static asmlinkage void __exception_irq_entry gic_handle_irq(struct pt_regs *regs)
268 {
269 	u64 irqnr;
270 
271 	do {
272 		irqnr = gic_read_iar();
273 
274 		if (likely(irqnr > 15 && irqnr < 1020)) {
275 			int err;
276 			err = handle_domain_irq(gic_data.domain, irqnr, regs);
277 			if (err) {
278 				WARN_ONCE(true, "Unexpected SPI received!\n");
279 				gic_write_eoir(irqnr);
280 			}
281 			continue;
282 		}
283 		if (irqnr < 16) {
284 			gic_write_eoir(irqnr);
285 #ifdef CONFIG_SMP
286 			/*
287 			 * Unlike GICv2, we don't need an smp_rmb() here.
288 			 * The control dependency from gic_read_iar to
289 			 * the ISB in gic_write_eoir is enough to ensure
290 			 * that any shared data read by handle_IPI will
291 			 * be read after the ACK.
292 			 */
293 			handle_IPI(irqnr, regs);
294 #else
295 			WARN_ONCE(true, "Unexpected SGI received!\n");
296 #endif
297 			continue;
298 		}
299 	} while (irqnr != ICC_IAR1_EL1_SPURIOUS);
300 }
301 
gic_dist_init(void)302 static void __init gic_dist_init(void)
303 {
304 	unsigned int i;
305 	u64 affinity;
306 	void __iomem *base = gic_data.dist_base;
307 
308 	/* Disable the distributor */
309 	writel_relaxed(0, base + GICD_CTLR);
310 	gic_dist_wait_for_rwp();
311 
312 	gic_dist_config(base, gic_data.irq_nr, gic_dist_wait_for_rwp);
313 
314 	/* Enable distributor with ARE, Group1 */
315 	writel_relaxed(GICD_CTLR_ARE_NS | GICD_CTLR_ENABLE_G1A | GICD_CTLR_ENABLE_G1,
316 		       base + GICD_CTLR);
317 
318 	/*
319 	 * Set all global interrupts to the boot CPU only. ARE must be
320 	 * enabled.
321 	 */
322 	affinity = gic_mpidr_to_affinity(cpu_logical_map(smp_processor_id()));
323 	for (i = 32; i < gic_data.irq_nr; i++)
324 		writeq_relaxed(affinity, base + GICD_IROUTER + i * 8);
325 }
326 
gic_populate_rdist(void)327 static int gic_populate_rdist(void)
328 {
329 	u64 mpidr = cpu_logical_map(smp_processor_id());
330 	u64 typer;
331 	u32 aff;
332 	int i;
333 
334 	/*
335 	 * Convert affinity to a 32bit value that can be matched to
336 	 * GICR_TYPER bits [63:32].
337 	 */
338 	aff = (MPIDR_AFFINITY_LEVEL(mpidr, 3) << 24 |
339 	       MPIDR_AFFINITY_LEVEL(mpidr, 2) << 16 |
340 	       MPIDR_AFFINITY_LEVEL(mpidr, 1) << 8 |
341 	       MPIDR_AFFINITY_LEVEL(mpidr, 0));
342 
343 	for (i = 0; i < gic_data.redist_regions; i++) {
344 		void __iomem *ptr = gic_data.redist_base[i];
345 		u32 reg;
346 
347 		reg = readl_relaxed(ptr + GICR_PIDR2) & GIC_PIDR2_ARCH_MASK;
348 		if (reg != GIC_PIDR2_ARCH_GICv3 &&
349 		    reg != GIC_PIDR2_ARCH_GICv4) { /* We're in trouble... */
350 			pr_warn("No redistributor present @%p\n", ptr);
351 			break;
352 		}
353 
354 		do {
355 			typer = readq_relaxed(ptr + GICR_TYPER);
356 			if ((typer >> 32) == aff) {
357 				gic_data_rdist_rd_base() = ptr;
358 				pr_info("CPU%d: found redistributor %llx @%p\n",
359 					smp_processor_id(),
360 					(unsigned long long)mpidr, ptr);
361 				return 0;
362 			}
363 
364 			if (gic_data.redist_stride) {
365 				ptr += gic_data.redist_stride;
366 			} else {
367 				ptr += SZ_64K * 2; /* Skip RD_base + SGI_base */
368 				if (typer & GICR_TYPER_VLPIS)
369 					ptr += SZ_64K * 2; /* Skip VLPI_base + reserved page */
370 			}
371 		} while (!(typer & GICR_TYPER_LAST));
372 	}
373 
374 	/* We couldn't even deal with ourselves... */
375 	WARN(true, "CPU%d: mpidr %llx has no re-distributor!\n",
376 	     smp_processor_id(), (unsigned long long)mpidr);
377 	return -ENODEV;
378 }
379 
gic_cpu_sys_reg_init(void)380 static void gic_cpu_sys_reg_init(void)
381 {
382 	/* Enable system registers */
383 	gic_enable_sre();
384 
385 	/* Set priority mask register */
386 	gic_write_pmr(DEFAULT_PMR_VALUE);
387 
388 	/* EOI deactivates interrupt too (mode 0) */
389 	gic_write_ctlr(ICC_CTLR_EL1_EOImode_drop_dir);
390 
391 	/* ... and let's hit the road... */
392 	gic_write_grpen1(1);
393 }
394 
gic_cpu_init(void)395 static void gic_cpu_init(void)
396 {
397 	void __iomem *rbase;
398 
399 	/* Register ourselves with the rest of the world */
400 	if (gic_populate_rdist())
401 		return;
402 
403 	gic_enable_redist(true);
404 
405 	rbase = gic_data_rdist_sgi_base();
406 
407 	gic_cpu_config(rbase, gic_redist_wait_for_rwp);
408 
409 	/* initialise system registers */
410 	gic_cpu_sys_reg_init();
411 }
412 
413 #ifdef CONFIG_SMP
gic_peek_irq(struct irq_data * d,u32 offset)414 static int gic_peek_irq(struct irq_data *d, u32 offset)
415 {
416 	u32 mask = 1 << (gic_irq(d) % 32);
417 	void __iomem *base;
418 
419 	if (gic_irq_in_rdist(d))
420 		base = gic_data_rdist_sgi_base();
421 	else
422 		base = gic_data.dist_base;
423 
424 	return !!(readl_relaxed(base + offset + (gic_irq(d) / 32) * 4) & mask);
425 }
426 
gic_secondary_init(struct notifier_block * nfb,unsigned long action,void * hcpu)427 static int gic_secondary_init(struct notifier_block *nfb,
428 			      unsigned long action, void *hcpu)
429 {
430 	if (action == CPU_STARTING || action == CPU_STARTING_FROZEN)
431 		gic_cpu_init();
432 	return NOTIFY_OK;
433 }
434 
435 /*
436  * Notifier for enabling the GIC CPU interface. Set an arbitrarily high
437  * priority because the GIC needs to be up before the ARM generic timers.
438  */
439 static struct notifier_block gic_cpu_notifier = {
440 	.notifier_call = gic_secondary_init,
441 	.priority = 100,
442 };
443 
gic_compute_target_list(int * base_cpu,const struct cpumask * mask,u64 cluster_id)444 static u16 gic_compute_target_list(int *base_cpu, const struct cpumask *mask,
445 				   u64 cluster_id)
446 {
447 	int cpu = *base_cpu;
448 	u64 mpidr = cpu_logical_map(cpu);
449 	u16 tlist = 0;
450 
451 	while (cpu < nr_cpu_ids) {
452 		/*
453 		 * If we ever get a cluster of more than 16 CPUs, just
454 		 * scream and skip that CPU.
455 		 */
456 		if (WARN_ON((mpidr & 0xff) >= 16))
457 			goto out;
458 
459 		tlist |= 1 << (mpidr & 0xf);
460 
461 		cpu = cpumask_next(cpu, mask);
462 		if (cpu == nr_cpu_ids)
463 			goto out;
464 
465 		mpidr = cpu_logical_map(cpu);
466 
467 		if (cluster_id != (mpidr & ~0xffUL)) {
468 			cpu--;
469 			goto out;
470 		}
471 	}
472 out:
473 	*base_cpu = cpu;
474 	return tlist;
475 }
476 
477 #define MPIDR_TO_SGI_AFFINITY(cluster_id, level) \
478 	(MPIDR_AFFINITY_LEVEL(cluster_id, level) \
479 		<< ICC_SGI1R_AFFINITY_## level ##_SHIFT)
480 
gic_send_sgi(u64 cluster_id,u16 tlist,unsigned int irq)481 static void gic_send_sgi(u64 cluster_id, u16 tlist, unsigned int irq)
482 {
483 	u64 val;
484 
485 	val = (MPIDR_TO_SGI_AFFINITY(cluster_id, 3)	|
486 	       MPIDR_TO_SGI_AFFINITY(cluster_id, 2)	|
487 	       irq << ICC_SGI1R_SGI_ID_SHIFT		|
488 	       MPIDR_TO_SGI_AFFINITY(cluster_id, 1)	|
489 	       tlist << ICC_SGI1R_TARGET_LIST_SHIFT);
490 
491 	pr_debug("CPU%d: ICC_SGI1R_EL1 %llx\n", smp_processor_id(), val);
492 	gic_write_sgi1r(val);
493 }
494 
gic_raise_softirq(const struct cpumask * mask,unsigned int irq)495 static void gic_raise_softirq(const struct cpumask *mask, unsigned int irq)
496 {
497 	int cpu;
498 
499 	if (WARN_ON(irq >= 16))
500 		return;
501 
502 	/*
503 	 * Ensure that stores to Normal memory are visible to the
504 	 * other CPUs before issuing the IPI.
505 	 */
506 	smp_wmb();
507 
508 	for_each_cpu_mask(cpu, *mask) {
509 		u64 cluster_id = cpu_logical_map(cpu) & ~0xffUL;
510 		u16 tlist;
511 
512 		tlist = gic_compute_target_list(&cpu, mask, cluster_id);
513 		gic_send_sgi(cluster_id, tlist, irq);
514 	}
515 
516 	/* Force the above writes to ICC_SGI1R_EL1 to be executed */
517 	isb();
518 }
519 
gic_smp_init(void)520 static void gic_smp_init(void)
521 {
522 	set_smp_cross_call(gic_raise_softirq);
523 	register_cpu_notifier(&gic_cpu_notifier);
524 }
525 
gic_set_affinity(struct irq_data * d,const struct cpumask * mask_val,bool force)526 static int gic_set_affinity(struct irq_data *d, const struct cpumask *mask_val,
527 			    bool force)
528 {
529 	unsigned int cpu = cpumask_any_and(mask_val, cpu_online_mask);
530 	void __iomem *reg;
531 	int enabled;
532 	u64 val;
533 
534 	if (cpu >= nr_cpu_ids)
535 		return -EINVAL;
536 
537 	if (gic_irq_in_rdist(d))
538 		return -EINVAL;
539 
540 	/* If interrupt was enabled, disable it first */
541 	enabled = gic_peek_irq(d, GICD_ISENABLER);
542 	if (enabled)
543 		gic_mask_irq(d);
544 
545 	reg = gic_dist_base(d) + GICD_IROUTER + (gic_irq(d) * 8);
546 	val = gic_mpidr_to_affinity(cpu_logical_map(cpu));
547 
548 	writeq_relaxed(val, reg);
549 
550 	/*
551 	 * If the interrupt was enabled, enabled it again. Otherwise,
552 	 * just wait for the distributor to have digested our changes.
553 	 */
554 	if (enabled)
555 		gic_unmask_irq(d);
556 	else
557 		gic_dist_wait_for_rwp();
558 
559 	return IRQ_SET_MASK_OK;
560 }
561 #else
562 #define gic_set_affinity	NULL
563 #define gic_smp_init()		do { } while(0)
564 #endif
565 
566 #ifdef CONFIG_CPU_PM
gic_cpu_pm_notifier(struct notifier_block * self,unsigned long cmd,void * v)567 static int gic_cpu_pm_notifier(struct notifier_block *self,
568 			       unsigned long cmd, void *v)
569 {
570 	if (cmd == CPU_PM_EXIT) {
571 		gic_enable_redist(true);
572 		gic_cpu_sys_reg_init();
573 	} else if (cmd == CPU_PM_ENTER) {
574 		gic_write_grpen1(0);
575 		gic_enable_redist(false);
576 	}
577 	return NOTIFY_OK;
578 }
579 
580 static struct notifier_block gic_cpu_pm_notifier_block = {
581 	.notifier_call = gic_cpu_pm_notifier,
582 };
583 
gic_cpu_pm_init(void)584 static void gic_cpu_pm_init(void)
585 {
586 	cpu_pm_register_notifier(&gic_cpu_pm_notifier_block);
587 }
588 
589 #else
gic_cpu_pm_init(void)590 static inline void gic_cpu_pm_init(void) { }
591 #endif /* CONFIG_CPU_PM */
592 
593 static struct irq_chip gic_chip = {
594 	.name			= "GICv3",
595 	.irq_mask		= gic_mask_irq,
596 	.irq_unmask		= gic_unmask_irq,
597 	.irq_eoi		= gic_eoi_irq,
598 	.irq_set_type		= gic_set_type,
599 	.irq_set_affinity	= gic_set_affinity,
600 };
601 
gic_irq_domain_map(struct irq_domain * d,unsigned int irq,irq_hw_number_t hw)602 static int gic_irq_domain_map(struct irq_domain *d, unsigned int irq,
603 			      irq_hw_number_t hw)
604 {
605 	/* SGIs are private to the core kernel */
606 	if (hw < 16)
607 		return -EPERM;
608 	/* PPIs */
609 	if (hw < 32) {
610 		irq_set_percpu_devid(irq);
611 		irq_set_chip_and_handler(irq, &gic_chip,
612 					 handle_percpu_devid_irq);
613 		set_irq_flags(irq, IRQF_VALID | IRQF_NOAUTOEN);
614 	}
615 	/* SPIs */
616 	if (hw >= 32 && hw < gic_data.irq_nr) {
617 		irq_set_chip_and_handler(irq, &gic_chip,
618 					 handle_fasteoi_irq);
619 		set_irq_flags(irq, IRQF_VALID | IRQF_PROBE);
620 	}
621 	irq_set_chip_data(irq, d->host_data);
622 	return 0;
623 }
624 
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)625 static int gic_irq_domain_xlate(struct irq_domain *d,
626 				struct device_node *controller,
627 				const u32 *intspec, unsigned int intsize,
628 				unsigned long *out_hwirq, unsigned int *out_type)
629 {
630 	if (d->of_node != controller)
631 		return -EINVAL;
632 	if (intsize < 3)
633 		return -EINVAL;
634 
635 	switch(intspec[0]) {
636 	case 0:			/* SPI */
637 		*out_hwirq = intspec[1] + 32;
638 		break;
639 	case 1:			/* PPI */
640 		*out_hwirq = intspec[1] + 16;
641 		break;
642 	default:
643 		return -EINVAL;
644 	}
645 
646 	*out_type = intspec[2] & IRQ_TYPE_SENSE_MASK;
647 	return 0;
648 }
649 
650 static const struct irq_domain_ops gic_irq_domain_ops = {
651 	.map = gic_irq_domain_map,
652 	.xlate = gic_irq_domain_xlate,
653 };
654 
gic_of_init(struct device_node * node,struct device_node * parent)655 static int __init gic_of_init(struct device_node *node, struct device_node *parent)
656 {
657 	void __iomem *dist_base;
658 	void __iomem **redist_base;
659 	u64 redist_stride;
660 	u32 redist_regions;
661 	u32 reg;
662 	int gic_irqs;
663 	int err;
664 	int i;
665 
666 	dist_base = of_iomap(node, 0);
667 	if (!dist_base) {
668 		pr_err("%s: unable to map gic dist registers\n",
669 			node->full_name);
670 		return -ENXIO;
671 	}
672 
673 	reg = readl_relaxed(dist_base + GICD_PIDR2) & GIC_PIDR2_ARCH_MASK;
674 	if (reg != GIC_PIDR2_ARCH_GICv3 && reg != GIC_PIDR2_ARCH_GICv4) {
675 		pr_err("%s: no distributor detected, giving up\n",
676 			node->full_name);
677 		err = -ENODEV;
678 		goto out_unmap_dist;
679 	}
680 
681 	if (of_property_read_u32(node, "#redistributor-regions", &redist_regions))
682 		redist_regions = 1;
683 
684 	redist_base = kzalloc(sizeof(*redist_base) * redist_regions, GFP_KERNEL);
685 	if (!redist_base) {
686 		err = -ENOMEM;
687 		goto out_unmap_dist;
688 	}
689 
690 	for (i = 0; i < redist_regions; i++) {
691 		redist_base[i] = of_iomap(node, 1 + i);
692 		if (!redist_base[i]) {
693 			pr_err("%s: couldn't map region %d\n",
694 			       node->full_name, i);
695 			err = -ENODEV;
696 			goto out_unmap_rdist;
697 		}
698 	}
699 
700 	if (of_property_read_u64(node, "redistributor-stride", &redist_stride))
701 		redist_stride = 0;
702 
703 	gic_data.dist_base = dist_base;
704 	gic_data.redist_base = redist_base;
705 	gic_data.redist_regions = redist_regions;
706 	gic_data.redist_stride = redist_stride;
707 
708 	/*
709 	 * Find out how many interrupts are supported.
710 	 * The GIC only supports up to 1020 interrupt sources (SGI+PPI+SPI)
711 	 */
712 	gic_irqs = readl_relaxed(gic_data.dist_base + GICD_TYPER) & 0x1f;
713 	gic_irqs = (gic_irqs + 1) * 32;
714 	if (gic_irqs > 1020)
715 		gic_irqs = 1020;
716 	gic_data.irq_nr = gic_irqs;
717 
718 	gic_data.domain = irq_domain_add_tree(node, &gic_irq_domain_ops,
719 					      &gic_data);
720 	gic_data.rdist = alloc_percpu(typeof(*gic_data.rdist));
721 
722 	if (WARN_ON(!gic_data.domain) || WARN_ON(!gic_data.rdist)) {
723 		err = -ENOMEM;
724 		goto out_free;
725 	}
726 
727 	set_handle_irq(gic_handle_irq);
728 
729 	gic_smp_init();
730 	gic_dist_init();
731 	gic_cpu_init();
732 	gic_cpu_pm_init();
733 
734 	return 0;
735 
736 out_free:
737 	if (gic_data.domain)
738 		irq_domain_remove(gic_data.domain);
739 	free_percpu(gic_data.rdist);
740 out_unmap_rdist:
741 	for (i = 0; i < redist_regions; i++)
742 		if (redist_base[i])
743 			iounmap(redist_base[i]);
744 	kfree(redist_base);
745 out_unmap_dist:
746 	iounmap(dist_base);
747 	return err;
748 }
749 
750 IRQCHIP_DECLARE(gic_v3, "arm,gic-v3", gic_of_init);
751