xref: /linux/drivers/irqchip/irq-gic.c (revision e0bf6c5ca2d3281f231c5f0c9bf145e9513644de)
1 /*
2  *  Copyright (C) 2002 ARM Limited, All Rights Reserved.
3  *
4  * This program is free software; you can redistribute it and/or modify
5  * it under the terms of the GNU General Public License version 2 as
6  * published by the Free Software Foundation.
7  *
8  * Interrupt architecture for the GIC:
9  *
10  * o There is one Interrupt Distributor, which receives interrupts
11  *   from system devices and sends them to the Interrupt Controllers.
12  *
13  * o There is one CPU Interface per CPU, which sends interrupts sent
14  *   by the Distributor, and interrupts generated locally, to the
15  *   associated CPU. The base address of the CPU interface is usually
16  *   aliased so that the same address points to different chips depending
17  *   on the CPU it is accessed from.
18  *
19  * Note that IRQs 0-31 are special - they are local to each CPU.
20  * As such, the enable set/clear, pending set/clear and active bit
21  * registers are banked per-cpu for these sources.
22  */
23 #include <linux/init.h>
24 #include <linux/kernel.h>
25 #include <linux/err.h>
26 #include <linux/module.h>
27 #include <linux/list.h>
28 #include <linux/smp.h>
29 #include <linux/cpu.h>
30 #include <linux/cpu_pm.h>
31 #include <linux/cpumask.h>
32 #include <linux/io.h>
33 #include <linux/of.h>
34 #include <linux/of_address.h>
35 #include <linux/of_irq.h>
36 #include <linux/irqdomain.h>
37 #include <linux/interrupt.h>
38 #include <linux/percpu.h>
39 #include <linux/slab.h>
40 #include <linux/irqchip/chained_irq.h>
41 #include <linux/irqchip/arm-gic.h>
42 
43 #include <asm/cputype.h>
44 #include <asm/irq.h>
45 #include <asm/exception.h>
46 #include <asm/smp_plat.h>
47 
48 #include "irq-gic-common.h"
49 #include "irqchip.h"
50 
51 union gic_base {
52 	void __iomem *common_base;
53 	void __percpu * __iomem *percpu_base;
54 };
55 
56 struct gic_chip_data {
57 	union gic_base dist_base;
58 	union gic_base cpu_base;
59 #ifdef CONFIG_CPU_PM
60 	u32 saved_spi_enable[DIV_ROUND_UP(1020, 32)];
61 	u32 saved_spi_conf[DIV_ROUND_UP(1020, 16)];
62 	u32 saved_spi_target[DIV_ROUND_UP(1020, 4)];
63 	u32 __percpu *saved_ppi_enable;
64 	u32 __percpu *saved_ppi_conf;
65 #endif
66 	struct irq_domain *domain;
67 	unsigned int gic_irqs;
68 #ifdef CONFIG_GIC_NON_BANKED
69 	void __iomem *(*get_base)(union gic_base *);
70 #endif
71 };
72 
73 static DEFINE_RAW_SPINLOCK(irq_controller_lock);
74 
75 /*
76  * The GIC mapping of CPU interfaces does not necessarily match
77  * the logical CPU numbering.  Let's use a mapping as returned
78  * by the GIC itself.
79  */
80 #define NR_GIC_CPU_IF 8
81 static u8 gic_cpu_map[NR_GIC_CPU_IF] __read_mostly;
82 
83 /*
84  * Supported arch specific GIC irq extension.
85  * Default make them NULL.
86  */
87 struct irq_chip gic_arch_extn = {
88 	.irq_eoi	= NULL,
89 	.irq_mask	= NULL,
90 	.irq_unmask	= NULL,
91 	.irq_retrigger	= NULL,
92 	.irq_set_type	= NULL,
93 	.irq_set_wake	= NULL,
94 };
95 
96 #ifndef MAX_GIC_NR
97 #define MAX_GIC_NR	1
98 #endif
99 
100 static struct gic_chip_data gic_data[MAX_GIC_NR] __read_mostly;
101 
102 #ifdef CONFIG_GIC_NON_BANKED
103 static void __iomem *gic_get_percpu_base(union gic_base *base)
104 {
105 	return raw_cpu_read(*base->percpu_base);
106 }
107 
108 static void __iomem *gic_get_common_base(union gic_base *base)
109 {
110 	return base->common_base;
111 }
112 
113 static inline void __iomem *gic_data_dist_base(struct gic_chip_data *data)
114 {
115 	return data->get_base(&data->dist_base);
116 }
117 
118 static inline void __iomem *gic_data_cpu_base(struct gic_chip_data *data)
119 {
120 	return data->get_base(&data->cpu_base);
121 }
122 
123 static inline void gic_set_base_accessor(struct gic_chip_data *data,
124 					 void __iomem *(*f)(union gic_base *))
125 {
126 	data->get_base = f;
127 }
128 #else
129 #define gic_data_dist_base(d)	((d)->dist_base.common_base)
130 #define gic_data_cpu_base(d)	((d)->cpu_base.common_base)
131 #define gic_set_base_accessor(d, f)
132 #endif
133 
134 static inline void __iomem *gic_dist_base(struct irq_data *d)
135 {
136 	struct gic_chip_data *gic_data = irq_data_get_irq_chip_data(d);
137 	return gic_data_dist_base(gic_data);
138 }
139 
140 static inline void __iomem *gic_cpu_base(struct irq_data *d)
141 {
142 	struct gic_chip_data *gic_data = irq_data_get_irq_chip_data(d);
143 	return gic_data_cpu_base(gic_data);
144 }
145 
146 static inline unsigned int gic_irq(struct irq_data *d)
147 {
148 	return d->hwirq;
149 }
150 
151 /*
152  * Routines to acknowledge, disable and enable interrupts
153  */
154 static void gic_mask_irq(struct irq_data *d)
155 {
156 	u32 mask = 1 << (gic_irq(d) % 32);
157 	unsigned long flags;
158 
159 	raw_spin_lock_irqsave(&irq_controller_lock, flags);
160 	writel_relaxed(mask, gic_dist_base(d) + GIC_DIST_ENABLE_CLEAR + (gic_irq(d) / 32) * 4);
161 	if (gic_arch_extn.irq_mask)
162 		gic_arch_extn.irq_mask(d);
163 	raw_spin_unlock_irqrestore(&irq_controller_lock, flags);
164 }
165 
166 static void gic_unmask_irq(struct irq_data *d)
167 {
168 	u32 mask = 1 << (gic_irq(d) % 32);
169 	unsigned long flags;
170 
171 	raw_spin_lock_irqsave(&irq_controller_lock, flags);
172 	if (gic_arch_extn.irq_unmask)
173 		gic_arch_extn.irq_unmask(d);
174 	writel_relaxed(mask, gic_dist_base(d) + GIC_DIST_ENABLE_SET + (gic_irq(d) / 32) * 4);
175 	raw_spin_unlock_irqrestore(&irq_controller_lock, flags);
176 }
177 
178 static void gic_eoi_irq(struct irq_data *d)
179 {
180 	if (gic_arch_extn.irq_eoi) {
181 		raw_spin_lock(&irq_controller_lock);
182 		gic_arch_extn.irq_eoi(d);
183 		raw_spin_unlock(&irq_controller_lock);
184 	}
185 
186 	writel_relaxed(gic_irq(d), gic_cpu_base(d) + GIC_CPU_EOI);
187 }
188 
189 static int gic_set_type(struct irq_data *d, unsigned int type)
190 {
191 	void __iomem *base = gic_dist_base(d);
192 	unsigned int gicirq = gic_irq(d);
193 	unsigned long flags;
194 	int ret;
195 
196 	/* Interrupt configuration for SGIs can't be changed */
197 	if (gicirq < 16)
198 		return -EINVAL;
199 
200 	/* SPIs have restrictions on the supported types */
201 	if (gicirq >= 32 && type != IRQ_TYPE_LEVEL_HIGH &&
202 			    type != IRQ_TYPE_EDGE_RISING)
203 		return -EINVAL;
204 
205 	raw_spin_lock_irqsave(&irq_controller_lock, flags);
206 
207 	if (gic_arch_extn.irq_set_type)
208 		gic_arch_extn.irq_set_type(d, type);
209 
210 	ret = gic_configure_irq(gicirq, type, base, NULL);
211 
212 	raw_spin_unlock_irqrestore(&irq_controller_lock, flags);
213 
214 	return ret;
215 }
216 
217 static int gic_retrigger(struct irq_data *d)
218 {
219 	if (gic_arch_extn.irq_retrigger)
220 		return gic_arch_extn.irq_retrigger(d);
221 
222 	/* the genirq layer expects 0 if we can't retrigger in hardware */
223 	return 0;
224 }
225 
226 #ifdef CONFIG_SMP
227 static int gic_set_affinity(struct irq_data *d, const struct cpumask *mask_val,
228 			    bool force)
229 {
230 	void __iomem *reg = gic_dist_base(d) + GIC_DIST_TARGET + (gic_irq(d) & ~3);
231 	unsigned int cpu, shift = (gic_irq(d) % 4) * 8;
232 	u32 val, mask, bit;
233 	unsigned long flags;
234 
235 	if (!force)
236 		cpu = cpumask_any_and(mask_val, cpu_online_mask);
237 	else
238 		cpu = cpumask_first(mask_val);
239 
240 	if (cpu >= NR_GIC_CPU_IF || cpu >= nr_cpu_ids)
241 		return -EINVAL;
242 
243 	raw_spin_lock_irqsave(&irq_controller_lock, flags);
244 	mask = 0xff << shift;
245 	bit = gic_cpu_map[cpu] << shift;
246 	val = readl_relaxed(reg) & ~mask;
247 	writel_relaxed(val | bit, reg);
248 	raw_spin_unlock_irqrestore(&irq_controller_lock, flags);
249 
250 	return IRQ_SET_MASK_OK;
251 }
252 #endif
253 
254 #ifdef CONFIG_PM
255 static int gic_set_wake(struct irq_data *d, unsigned int on)
256 {
257 	int ret = -ENXIO;
258 
259 	if (gic_arch_extn.irq_set_wake)
260 		ret = gic_arch_extn.irq_set_wake(d, on);
261 
262 	return ret;
263 }
264 
265 #else
266 #define gic_set_wake	NULL
267 #endif
268 
269 static void __exception_irq_entry gic_handle_irq(struct pt_regs *regs)
270 {
271 	u32 irqstat, irqnr;
272 	struct gic_chip_data *gic = &gic_data[0];
273 	void __iomem *cpu_base = gic_data_cpu_base(gic);
274 
275 	do {
276 		irqstat = readl_relaxed(cpu_base + GIC_CPU_INTACK);
277 		irqnr = irqstat & GICC_IAR_INT_ID_MASK;
278 
279 		if (likely(irqnr > 15 && irqnr < 1021)) {
280 			handle_domain_irq(gic->domain, irqnr, regs);
281 			continue;
282 		}
283 		if (irqnr < 16) {
284 			writel_relaxed(irqstat, cpu_base + GIC_CPU_EOI);
285 #ifdef CONFIG_SMP
286 			handle_IPI(irqnr, regs);
287 #endif
288 			continue;
289 		}
290 		break;
291 	} while (1);
292 }
293 
294 static void gic_handle_cascade_irq(unsigned int irq, struct irq_desc *desc)
295 {
296 	struct gic_chip_data *chip_data = irq_get_handler_data(irq);
297 	struct irq_chip *chip = irq_get_chip(irq);
298 	unsigned int cascade_irq, gic_irq;
299 	unsigned long status;
300 
301 	chained_irq_enter(chip, desc);
302 
303 	raw_spin_lock(&irq_controller_lock);
304 	status = readl_relaxed(gic_data_cpu_base(chip_data) + GIC_CPU_INTACK);
305 	raw_spin_unlock(&irq_controller_lock);
306 
307 	gic_irq = (status & GICC_IAR_INT_ID_MASK);
308 	if (gic_irq == GICC_INT_SPURIOUS)
309 		goto out;
310 
311 	cascade_irq = irq_find_mapping(chip_data->domain, gic_irq);
312 	if (unlikely(gic_irq < 32 || gic_irq > 1020))
313 		handle_bad_irq(cascade_irq, desc);
314 	else
315 		generic_handle_irq(cascade_irq);
316 
317  out:
318 	chained_irq_exit(chip, desc);
319 }
320 
321 static struct irq_chip gic_chip = {
322 	.name			= "GIC",
323 	.irq_mask		= gic_mask_irq,
324 	.irq_unmask		= gic_unmask_irq,
325 	.irq_eoi		= gic_eoi_irq,
326 	.irq_set_type		= gic_set_type,
327 	.irq_retrigger		= gic_retrigger,
328 #ifdef CONFIG_SMP
329 	.irq_set_affinity	= gic_set_affinity,
330 #endif
331 	.irq_set_wake		= gic_set_wake,
332 };
333 
334 void __init gic_cascade_irq(unsigned int gic_nr, unsigned int irq)
335 {
336 	if (gic_nr >= MAX_GIC_NR)
337 		BUG();
338 	if (irq_set_handler_data(irq, &gic_data[gic_nr]) != 0)
339 		BUG();
340 	irq_set_chained_handler(irq, gic_handle_cascade_irq);
341 }
342 
343 static u8 gic_get_cpumask(struct gic_chip_data *gic)
344 {
345 	void __iomem *base = gic_data_dist_base(gic);
346 	u32 mask, i;
347 
348 	for (i = mask = 0; i < 32; i += 4) {
349 		mask = readl_relaxed(base + GIC_DIST_TARGET + i);
350 		mask |= mask >> 16;
351 		mask |= mask >> 8;
352 		if (mask)
353 			break;
354 	}
355 
356 	if (!mask)
357 		pr_crit("GIC CPU mask not found - kernel will fail to boot.\n");
358 
359 	return mask;
360 }
361 
362 static void gic_cpu_if_up(void)
363 {
364 	void __iomem *cpu_base = gic_data_cpu_base(&gic_data[0]);
365 	u32 bypass = 0;
366 
367 	/*
368 	* Preserve bypass disable bits to be written back later
369 	*/
370 	bypass = readl(cpu_base + GIC_CPU_CTRL);
371 	bypass &= GICC_DIS_BYPASS_MASK;
372 
373 	writel_relaxed(bypass | GICC_ENABLE, cpu_base + GIC_CPU_CTRL);
374 }
375 
376 
377 static void __init gic_dist_init(struct gic_chip_data *gic)
378 {
379 	unsigned int i;
380 	u32 cpumask;
381 	unsigned int gic_irqs = gic->gic_irqs;
382 	void __iomem *base = gic_data_dist_base(gic);
383 
384 	writel_relaxed(GICD_DISABLE, base + GIC_DIST_CTRL);
385 
386 	/*
387 	 * Set all global interrupts to this CPU only.
388 	 */
389 	cpumask = gic_get_cpumask(gic);
390 	cpumask |= cpumask << 8;
391 	cpumask |= cpumask << 16;
392 	for (i = 32; i < gic_irqs; i += 4)
393 		writel_relaxed(cpumask, base + GIC_DIST_TARGET + i * 4 / 4);
394 
395 	gic_dist_config(base, gic_irqs, NULL);
396 
397 	writel_relaxed(GICD_ENABLE, base + GIC_DIST_CTRL);
398 }
399 
400 static void gic_cpu_init(struct gic_chip_data *gic)
401 {
402 	void __iomem *dist_base = gic_data_dist_base(gic);
403 	void __iomem *base = gic_data_cpu_base(gic);
404 	unsigned int cpu_mask, cpu = smp_processor_id();
405 	int i;
406 
407 	/*
408 	 * Get what the GIC says our CPU mask is.
409 	 */
410 	BUG_ON(cpu >= NR_GIC_CPU_IF);
411 	cpu_mask = gic_get_cpumask(gic);
412 	gic_cpu_map[cpu] = cpu_mask;
413 
414 	/*
415 	 * Clear our mask from the other map entries in case they're
416 	 * still undefined.
417 	 */
418 	for (i = 0; i < NR_GIC_CPU_IF; i++)
419 		if (i != cpu)
420 			gic_cpu_map[i] &= ~cpu_mask;
421 
422 	gic_cpu_config(dist_base, NULL);
423 
424 	writel_relaxed(GICC_INT_PRI_THRESHOLD, base + GIC_CPU_PRIMASK);
425 	gic_cpu_if_up();
426 }
427 
428 void gic_cpu_if_down(void)
429 {
430 	void __iomem *cpu_base = gic_data_cpu_base(&gic_data[0]);
431 	u32 val = 0;
432 
433 	val = readl(cpu_base + GIC_CPU_CTRL);
434 	val &= ~GICC_ENABLE;
435 	writel_relaxed(val, cpu_base + GIC_CPU_CTRL);
436 }
437 
438 #ifdef CONFIG_CPU_PM
439 /*
440  * Saves the GIC distributor registers during suspend or idle.  Must be called
441  * with interrupts disabled but before powering down the GIC.  After calling
442  * this function, no interrupts will be delivered by the GIC, and another
443  * platform-specific wakeup source must be enabled.
444  */
445 static void gic_dist_save(unsigned int gic_nr)
446 {
447 	unsigned int gic_irqs;
448 	void __iomem *dist_base;
449 	int i;
450 
451 	if (gic_nr >= MAX_GIC_NR)
452 		BUG();
453 
454 	gic_irqs = gic_data[gic_nr].gic_irqs;
455 	dist_base = gic_data_dist_base(&gic_data[gic_nr]);
456 
457 	if (!dist_base)
458 		return;
459 
460 	for (i = 0; i < DIV_ROUND_UP(gic_irqs, 16); i++)
461 		gic_data[gic_nr].saved_spi_conf[i] =
462 			readl_relaxed(dist_base + GIC_DIST_CONFIG + i * 4);
463 
464 	for (i = 0; i < DIV_ROUND_UP(gic_irqs, 4); i++)
465 		gic_data[gic_nr].saved_spi_target[i] =
466 			readl_relaxed(dist_base + GIC_DIST_TARGET + i * 4);
467 
468 	for (i = 0; i < DIV_ROUND_UP(gic_irqs, 32); i++)
469 		gic_data[gic_nr].saved_spi_enable[i] =
470 			readl_relaxed(dist_base + GIC_DIST_ENABLE_SET + i * 4);
471 }
472 
473 /*
474  * Restores the GIC distributor registers during resume or when coming out of
475  * idle.  Must be called before enabling interrupts.  If a level interrupt
476  * that occured while the GIC was suspended is still present, it will be
477  * handled normally, but any edge interrupts that occured will not be seen by
478  * the GIC and need to be handled by the platform-specific wakeup source.
479  */
480 static void gic_dist_restore(unsigned int gic_nr)
481 {
482 	unsigned int gic_irqs;
483 	unsigned int i;
484 	void __iomem *dist_base;
485 
486 	if (gic_nr >= MAX_GIC_NR)
487 		BUG();
488 
489 	gic_irqs = gic_data[gic_nr].gic_irqs;
490 	dist_base = gic_data_dist_base(&gic_data[gic_nr]);
491 
492 	if (!dist_base)
493 		return;
494 
495 	writel_relaxed(GICD_DISABLE, dist_base + GIC_DIST_CTRL);
496 
497 	for (i = 0; i < DIV_ROUND_UP(gic_irqs, 16); i++)
498 		writel_relaxed(gic_data[gic_nr].saved_spi_conf[i],
499 			dist_base + GIC_DIST_CONFIG + i * 4);
500 
501 	for (i = 0; i < DIV_ROUND_UP(gic_irqs, 4); i++)
502 		writel_relaxed(GICD_INT_DEF_PRI_X4,
503 			dist_base + GIC_DIST_PRI + i * 4);
504 
505 	for (i = 0; i < DIV_ROUND_UP(gic_irqs, 4); i++)
506 		writel_relaxed(gic_data[gic_nr].saved_spi_target[i],
507 			dist_base + GIC_DIST_TARGET + i * 4);
508 
509 	for (i = 0; i < DIV_ROUND_UP(gic_irqs, 32); i++)
510 		writel_relaxed(gic_data[gic_nr].saved_spi_enable[i],
511 			dist_base + GIC_DIST_ENABLE_SET + i * 4);
512 
513 	writel_relaxed(GICD_ENABLE, dist_base + GIC_DIST_CTRL);
514 }
515 
516 static void gic_cpu_save(unsigned int gic_nr)
517 {
518 	int i;
519 	u32 *ptr;
520 	void __iomem *dist_base;
521 	void __iomem *cpu_base;
522 
523 	if (gic_nr >= MAX_GIC_NR)
524 		BUG();
525 
526 	dist_base = gic_data_dist_base(&gic_data[gic_nr]);
527 	cpu_base = gic_data_cpu_base(&gic_data[gic_nr]);
528 
529 	if (!dist_base || !cpu_base)
530 		return;
531 
532 	ptr = raw_cpu_ptr(gic_data[gic_nr].saved_ppi_enable);
533 	for (i = 0; i < DIV_ROUND_UP(32, 32); i++)
534 		ptr[i] = readl_relaxed(dist_base + GIC_DIST_ENABLE_SET + i * 4);
535 
536 	ptr = raw_cpu_ptr(gic_data[gic_nr].saved_ppi_conf);
537 	for (i = 0; i < DIV_ROUND_UP(32, 16); i++)
538 		ptr[i] = readl_relaxed(dist_base + GIC_DIST_CONFIG + i * 4);
539 
540 }
541 
542 static void gic_cpu_restore(unsigned int gic_nr)
543 {
544 	int i;
545 	u32 *ptr;
546 	void __iomem *dist_base;
547 	void __iomem *cpu_base;
548 
549 	if (gic_nr >= MAX_GIC_NR)
550 		BUG();
551 
552 	dist_base = gic_data_dist_base(&gic_data[gic_nr]);
553 	cpu_base = gic_data_cpu_base(&gic_data[gic_nr]);
554 
555 	if (!dist_base || !cpu_base)
556 		return;
557 
558 	ptr = raw_cpu_ptr(gic_data[gic_nr].saved_ppi_enable);
559 	for (i = 0; i < DIV_ROUND_UP(32, 32); i++)
560 		writel_relaxed(ptr[i], dist_base + GIC_DIST_ENABLE_SET + i * 4);
561 
562 	ptr = raw_cpu_ptr(gic_data[gic_nr].saved_ppi_conf);
563 	for (i = 0; i < DIV_ROUND_UP(32, 16); i++)
564 		writel_relaxed(ptr[i], dist_base + GIC_DIST_CONFIG + i * 4);
565 
566 	for (i = 0; i < DIV_ROUND_UP(32, 4); i++)
567 		writel_relaxed(GICD_INT_DEF_PRI_X4,
568 					dist_base + GIC_DIST_PRI + i * 4);
569 
570 	writel_relaxed(GICC_INT_PRI_THRESHOLD, cpu_base + GIC_CPU_PRIMASK);
571 	gic_cpu_if_up();
572 }
573 
574 static int gic_notifier(struct notifier_block *self, unsigned long cmd,	void *v)
575 {
576 	int i;
577 
578 	for (i = 0; i < MAX_GIC_NR; i++) {
579 #ifdef CONFIG_GIC_NON_BANKED
580 		/* Skip over unused GICs */
581 		if (!gic_data[i].get_base)
582 			continue;
583 #endif
584 		switch (cmd) {
585 		case CPU_PM_ENTER:
586 			gic_cpu_save(i);
587 			break;
588 		case CPU_PM_ENTER_FAILED:
589 		case CPU_PM_EXIT:
590 			gic_cpu_restore(i);
591 			break;
592 		case CPU_CLUSTER_PM_ENTER:
593 			gic_dist_save(i);
594 			break;
595 		case CPU_CLUSTER_PM_ENTER_FAILED:
596 		case CPU_CLUSTER_PM_EXIT:
597 			gic_dist_restore(i);
598 			break;
599 		}
600 	}
601 
602 	return NOTIFY_OK;
603 }
604 
605 static struct notifier_block gic_notifier_block = {
606 	.notifier_call = gic_notifier,
607 };
608 
609 static void __init gic_pm_init(struct gic_chip_data *gic)
610 {
611 	gic->saved_ppi_enable = __alloc_percpu(DIV_ROUND_UP(32, 32) * 4,
612 		sizeof(u32));
613 	BUG_ON(!gic->saved_ppi_enable);
614 
615 	gic->saved_ppi_conf = __alloc_percpu(DIV_ROUND_UP(32, 16) * 4,
616 		sizeof(u32));
617 	BUG_ON(!gic->saved_ppi_conf);
618 
619 	if (gic == &gic_data[0])
620 		cpu_pm_register_notifier(&gic_notifier_block);
621 }
622 #else
623 static void __init gic_pm_init(struct gic_chip_data *gic)
624 {
625 }
626 #endif
627 
628 #ifdef CONFIG_SMP
629 static void gic_raise_softirq(const struct cpumask *mask, unsigned int irq)
630 {
631 	int cpu;
632 	unsigned long flags, map = 0;
633 
634 	raw_spin_lock_irqsave(&irq_controller_lock, flags);
635 
636 	/* Convert our logical CPU mask into a physical one. */
637 	for_each_cpu(cpu, mask)
638 		map |= gic_cpu_map[cpu];
639 
640 	/*
641 	 * Ensure that stores to Normal memory are visible to the
642 	 * other CPUs before they observe us issuing the IPI.
643 	 */
644 	dmb(ishst);
645 
646 	/* this always happens on GIC0 */
647 	writel_relaxed(map << 16 | irq, gic_data_dist_base(&gic_data[0]) + GIC_DIST_SOFTINT);
648 
649 	raw_spin_unlock_irqrestore(&irq_controller_lock, flags);
650 }
651 #endif
652 
653 #ifdef CONFIG_BL_SWITCHER
654 /*
655  * gic_send_sgi - send a SGI directly to given CPU interface number
656  *
657  * cpu_id: the ID for the destination CPU interface
658  * irq: the IPI number to send a SGI for
659  */
660 void gic_send_sgi(unsigned int cpu_id, unsigned int irq)
661 {
662 	BUG_ON(cpu_id >= NR_GIC_CPU_IF);
663 	cpu_id = 1 << cpu_id;
664 	/* this always happens on GIC0 */
665 	writel_relaxed((cpu_id << 16) | irq, gic_data_dist_base(&gic_data[0]) + GIC_DIST_SOFTINT);
666 }
667 
668 /*
669  * gic_get_cpu_id - get the CPU interface ID for the specified CPU
670  *
671  * @cpu: the logical CPU number to get the GIC ID for.
672  *
673  * Return the CPU interface ID for the given logical CPU number,
674  * or -1 if the CPU number is too large or the interface ID is
675  * unknown (more than one bit set).
676  */
677 int gic_get_cpu_id(unsigned int cpu)
678 {
679 	unsigned int cpu_bit;
680 
681 	if (cpu >= NR_GIC_CPU_IF)
682 		return -1;
683 	cpu_bit = gic_cpu_map[cpu];
684 	if (cpu_bit & (cpu_bit - 1))
685 		return -1;
686 	return __ffs(cpu_bit);
687 }
688 
689 /*
690  * gic_migrate_target - migrate IRQs to another CPU interface
691  *
692  * @new_cpu_id: the CPU target ID to migrate IRQs to
693  *
694  * Migrate all peripheral interrupts with a target matching the current CPU
695  * to the interface corresponding to @new_cpu_id.  The CPU interface mapping
696  * is also updated.  Targets to other CPU interfaces are unchanged.
697  * This must be called with IRQs locally disabled.
698  */
699 void gic_migrate_target(unsigned int new_cpu_id)
700 {
701 	unsigned int cur_cpu_id, gic_irqs, gic_nr = 0;
702 	void __iomem *dist_base;
703 	int i, ror_val, cpu = smp_processor_id();
704 	u32 val, cur_target_mask, active_mask;
705 
706 	if (gic_nr >= MAX_GIC_NR)
707 		BUG();
708 
709 	dist_base = gic_data_dist_base(&gic_data[gic_nr]);
710 	if (!dist_base)
711 		return;
712 	gic_irqs = gic_data[gic_nr].gic_irqs;
713 
714 	cur_cpu_id = __ffs(gic_cpu_map[cpu]);
715 	cur_target_mask = 0x01010101 << cur_cpu_id;
716 	ror_val = (cur_cpu_id - new_cpu_id) & 31;
717 
718 	raw_spin_lock(&irq_controller_lock);
719 
720 	/* Update the target interface for this logical CPU */
721 	gic_cpu_map[cpu] = 1 << new_cpu_id;
722 
723 	/*
724 	 * Find all the peripheral interrupts targetting the current
725 	 * CPU interface and migrate them to the new CPU interface.
726 	 * We skip DIST_TARGET 0 to 7 as they are read-only.
727 	 */
728 	for (i = 8; i < DIV_ROUND_UP(gic_irqs, 4); i++) {
729 		val = readl_relaxed(dist_base + GIC_DIST_TARGET + i * 4);
730 		active_mask = val & cur_target_mask;
731 		if (active_mask) {
732 			val &= ~active_mask;
733 			val |= ror32(active_mask, ror_val);
734 			writel_relaxed(val, dist_base + GIC_DIST_TARGET + i*4);
735 		}
736 	}
737 
738 	raw_spin_unlock(&irq_controller_lock);
739 
740 	/*
741 	 * Now let's migrate and clear any potential SGIs that might be
742 	 * pending for us (cur_cpu_id).  Since GIC_DIST_SGI_PENDING_SET
743 	 * is a banked register, we can only forward the SGI using
744 	 * GIC_DIST_SOFTINT.  The original SGI source is lost but Linux
745 	 * doesn't use that information anyway.
746 	 *
747 	 * For the same reason we do not adjust SGI source information
748 	 * for previously sent SGIs by us to other CPUs either.
749 	 */
750 	for (i = 0; i < 16; i += 4) {
751 		int j;
752 		val = readl_relaxed(dist_base + GIC_DIST_SGI_PENDING_SET + i);
753 		if (!val)
754 			continue;
755 		writel_relaxed(val, dist_base + GIC_DIST_SGI_PENDING_CLEAR + i);
756 		for (j = i; j < i + 4; j++) {
757 			if (val & 0xff)
758 				writel_relaxed((1 << (new_cpu_id + 16)) | j,
759 						dist_base + GIC_DIST_SOFTINT);
760 			val >>= 8;
761 		}
762 	}
763 }
764 
765 /*
766  * gic_get_sgir_physaddr - get the physical address for the SGI register
767  *
768  * REturn the physical address of the SGI register to be used
769  * by some early assembly code when the kernel is not yet available.
770  */
771 static unsigned long gic_dist_physaddr;
772 
773 unsigned long gic_get_sgir_physaddr(void)
774 {
775 	if (!gic_dist_physaddr)
776 		return 0;
777 	return gic_dist_physaddr + GIC_DIST_SOFTINT;
778 }
779 
780 void __init gic_init_physaddr(struct device_node *node)
781 {
782 	struct resource res;
783 	if (of_address_to_resource(node, 0, &res) == 0) {
784 		gic_dist_physaddr = res.start;
785 		pr_info("GIC physical location is %#lx\n", gic_dist_physaddr);
786 	}
787 }
788 
789 #else
790 #define gic_init_physaddr(node)  do { } while (0)
791 #endif
792 
793 static int gic_irq_domain_map(struct irq_domain *d, unsigned int irq,
794 				irq_hw_number_t hw)
795 {
796 	if (hw < 32) {
797 		irq_set_percpu_devid(irq);
798 		irq_domain_set_info(d, irq, hw, &gic_chip, d->host_data,
799 				    handle_percpu_devid_irq, NULL, NULL);
800 		set_irq_flags(irq, IRQF_VALID | IRQF_NOAUTOEN);
801 	} else {
802 		irq_domain_set_info(d, irq, hw, &gic_chip, d->host_data,
803 				    handle_fasteoi_irq, NULL, NULL);
804 		set_irq_flags(irq, IRQF_VALID | IRQF_PROBE);
805 
806 		gic_routable_irq_domain_ops->map(d, irq, hw);
807 	}
808 	return 0;
809 }
810 
811 static void gic_irq_domain_unmap(struct irq_domain *d, unsigned int irq)
812 {
813 	gic_routable_irq_domain_ops->unmap(d, irq);
814 }
815 
816 static int gic_irq_domain_xlate(struct irq_domain *d,
817 				struct device_node *controller,
818 				const u32 *intspec, unsigned int intsize,
819 				unsigned long *out_hwirq, unsigned int *out_type)
820 {
821 	unsigned long ret = 0;
822 
823 	if (d->of_node != controller)
824 		return -EINVAL;
825 	if (intsize < 3)
826 		return -EINVAL;
827 
828 	/* Get the interrupt number and add 16 to skip over SGIs */
829 	*out_hwirq = intspec[1] + 16;
830 
831 	/* For SPIs, we need to add 16 more to get the GIC irq ID number */
832 	if (!intspec[0]) {
833 		ret = gic_routable_irq_domain_ops->xlate(d, controller,
834 							 intspec,
835 							 intsize,
836 							 out_hwirq,
837 							 out_type);
838 
839 		if (IS_ERR_VALUE(ret))
840 			return ret;
841 	}
842 
843 	*out_type = intspec[2] & IRQ_TYPE_SENSE_MASK;
844 
845 	return ret;
846 }
847 
848 #ifdef CONFIG_SMP
849 static int gic_secondary_init(struct notifier_block *nfb, unsigned long action,
850 			      void *hcpu)
851 {
852 	if (action == CPU_STARTING || action == CPU_STARTING_FROZEN)
853 		gic_cpu_init(&gic_data[0]);
854 	return NOTIFY_OK;
855 }
856 
857 /*
858  * Notifier for enabling the GIC CPU interface. Set an arbitrarily high
859  * priority because the GIC needs to be up before the ARM generic timers.
860  */
861 static struct notifier_block gic_cpu_notifier = {
862 	.notifier_call = gic_secondary_init,
863 	.priority = 100,
864 };
865 #endif
866 
867 static int gic_irq_domain_alloc(struct irq_domain *domain, unsigned int virq,
868 				unsigned int nr_irqs, void *arg)
869 {
870 	int i, ret;
871 	irq_hw_number_t hwirq;
872 	unsigned int type = IRQ_TYPE_NONE;
873 	struct of_phandle_args *irq_data = arg;
874 
875 	ret = gic_irq_domain_xlate(domain, irq_data->np, irq_data->args,
876 				   irq_data->args_count, &hwirq, &type);
877 	if (ret)
878 		return ret;
879 
880 	for (i = 0; i < nr_irqs; i++)
881 		gic_irq_domain_map(domain, virq + i, hwirq + i);
882 
883 	return 0;
884 }
885 
886 static const struct irq_domain_ops gic_irq_domain_hierarchy_ops = {
887 	.xlate = gic_irq_domain_xlate,
888 	.alloc = gic_irq_domain_alloc,
889 	.free = irq_domain_free_irqs_top,
890 };
891 
892 static const struct irq_domain_ops gic_irq_domain_ops = {
893 	.map = gic_irq_domain_map,
894 	.unmap = gic_irq_domain_unmap,
895 	.xlate = gic_irq_domain_xlate,
896 };
897 
898 /* Default functions for routable irq domain */
899 static int gic_routable_irq_domain_map(struct irq_domain *d, unsigned int irq,
900 			      irq_hw_number_t hw)
901 {
902 	return 0;
903 }
904 
905 static void gic_routable_irq_domain_unmap(struct irq_domain *d,
906 					  unsigned int irq)
907 {
908 }
909 
910 static int gic_routable_irq_domain_xlate(struct irq_domain *d,
911 				struct device_node *controller,
912 				const u32 *intspec, unsigned int intsize,
913 				unsigned long *out_hwirq,
914 				unsigned int *out_type)
915 {
916 	*out_hwirq += 16;
917 	return 0;
918 }
919 
920 static const struct irq_domain_ops gic_default_routable_irq_domain_ops = {
921 	.map = gic_routable_irq_domain_map,
922 	.unmap = gic_routable_irq_domain_unmap,
923 	.xlate = gic_routable_irq_domain_xlate,
924 };
925 
926 const struct irq_domain_ops *gic_routable_irq_domain_ops =
927 					&gic_default_routable_irq_domain_ops;
928 
929 void __init gic_init_bases(unsigned int gic_nr, int irq_start,
930 			   void __iomem *dist_base, void __iomem *cpu_base,
931 			   u32 percpu_offset, struct device_node *node)
932 {
933 	irq_hw_number_t hwirq_base;
934 	struct gic_chip_data *gic;
935 	int gic_irqs, irq_base, i;
936 	int nr_routable_irqs;
937 
938 	BUG_ON(gic_nr >= MAX_GIC_NR);
939 
940 	gic = &gic_data[gic_nr];
941 #ifdef CONFIG_GIC_NON_BANKED
942 	if (percpu_offset) { /* Frankein-GIC without banked registers... */
943 		unsigned int cpu;
944 
945 		gic->dist_base.percpu_base = alloc_percpu(void __iomem *);
946 		gic->cpu_base.percpu_base = alloc_percpu(void __iomem *);
947 		if (WARN_ON(!gic->dist_base.percpu_base ||
948 			    !gic->cpu_base.percpu_base)) {
949 			free_percpu(gic->dist_base.percpu_base);
950 			free_percpu(gic->cpu_base.percpu_base);
951 			return;
952 		}
953 
954 		for_each_possible_cpu(cpu) {
955 			u32 mpidr = cpu_logical_map(cpu);
956 			u32 core_id = MPIDR_AFFINITY_LEVEL(mpidr, 0);
957 			unsigned long offset = percpu_offset * core_id;
958 			*per_cpu_ptr(gic->dist_base.percpu_base, cpu) = dist_base + offset;
959 			*per_cpu_ptr(gic->cpu_base.percpu_base, cpu) = cpu_base + offset;
960 		}
961 
962 		gic_set_base_accessor(gic, gic_get_percpu_base);
963 	} else
964 #endif
965 	{			/* Normal, sane GIC... */
966 		WARN(percpu_offset,
967 		     "GIC_NON_BANKED not enabled, ignoring %08x offset!",
968 		     percpu_offset);
969 		gic->dist_base.common_base = dist_base;
970 		gic->cpu_base.common_base = cpu_base;
971 		gic_set_base_accessor(gic, gic_get_common_base);
972 	}
973 
974 	/*
975 	 * Initialize the CPU interface map to all CPUs.
976 	 * It will be refined as each CPU probes its ID.
977 	 */
978 	for (i = 0; i < NR_GIC_CPU_IF; i++)
979 		gic_cpu_map[i] = 0xff;
980 
981 	/*
982 	 * Find out how many interrupts are supported.
983 	 * The GIC only supports up to 1020 interrupt sources.
984 	 */
985 	gic_irqs = readl_relaxed(gic_data_dist_base(gic) + GIC_DIST_CTR) & 0x1f;
986 	gic_irqs = (gic_irqs + 1) * 32;
987 	if (gic_irqs > 1020)
988 		gic_irqs = 1020;
989 	gic->gic_irqs = gic_irqs;
990 
991 	if (node) {		/* DT case */
992 		const struct irq_domain_ops *ops = &gic_irq_domain_hierarchy_ops;
993 
994 		if (!of_property_read_u32(node, "arm,routable-irqs",
995 					  &nr_routable_irqs)) {
996 			ops = &gic_irq_domain_ops;
997 			gic_irqs = nr_routable_irqs;
998 		}
999 
1000 		gic->domain = irq_domain_add_linear(node, gic_irqs, ops, gic);
1001 	} else {		/* Non-DT case */
1002 		/*
1003 		 * For primary GICs, skip over SGIs.
1004 		 * For secondary GICs, skip over PPIs, too.
1005 		 */
1006 		if (gic_nr == 0 && (irq_start & 31) > 0) {
1007 			hwirq_base = 16;
1008 			if (irq_start != -1)
1009 				irq_start = (irq_start & ~31) + 16;
1010 		} else {
1011 			hwirq_base = 32;
1012 		}
1013 
1014 		gic_irqs -= hwirq_base; /* calculate # of irqs to allocate */
1015 
1016 		irq_base = irq_alloc_descs(irq_start, 16, gic_irqs,
1017 					   numa_node_id());
1018 		if (IS_ERR_VALUE(irq_base)) {
1019 			WARN(1, "Cannot allocate irq_descs @ IRQ%d, assuming pre-allocated\n",
1020 			     irq_start);
1021 			irq_base = irq_start;
1022 		}
1023 
1024 		gic->domain = irq_domain_add_legacy(node, gic_irqs, irq_base,
1025 					hwirq_base, &gic_irq_domain_ops, gic);
1026 	}
1027 
1028 	if (WARN_ON(!gic->domain))
1029 		return;
1030 
1031 	if (gic_nr == 0) {
1032 #ifdef CONFIG_SMP
1033 		set_smp_cross_call(gic_raise_softirq);
1034 		register_cpu_notifier(&gic_cpu_notifier);
1035 #endif
1036 		set_handle_irq(gic_handle_irq);
1037 	}
1038 
1039 	gic_chip.flags |= gic_arch_extn.flags;
1040 	gic_dist_init(gic);
1041 	gic_cpu_init(gic);
1042 	gic_pm_init(gic);
1043 }
1044 
1045 #ifdef CONFIG_OF
1046 static int gic_cnt __initdata;
1047 
1048 static int __init
1049 gic_of_init(struct device_node *node, struct device_node *parent)
1050 {
1051 	void __iomem *cpu_base;
1052 	void __iomem *dist_base;
1053 	u32 percpu_offset;
1054 	int irq;
1055 
1056 	if (WARN_ON(!node))
1057 		return -ENODEV;
1058 
1059 	dist_base = of_iomap(node, 0);
1060 	WARN(!dist_base, "unable to map gic dist registers\n");
1061 
1062 	cpu_base = of_iomap(node, 1);
1063 	WARN(!cpu_base, "unable to map gic cpu registers\n");
1064 
1065 	if (of_property_read_u32(node, "cpu-offset", &percpu_offset))
1066 		percpu_offset = 0;
1067 
1068 	gic_init_bases(gic_cnt, -1, dist_base, cpu_base, percpu_offset, node);
1069 	if (!gic_cnt)
1070 		gic_init_physaddr(node);
1071 
1072 	if (parent) {
1073 		irq = irq_of_parse_and_map(node, 0);
1074 		gic_cascade_irq(gic_cnt, irq);
1075 	}
1076 
1077 	if (IS_ENABLED(CONFIG_ARM_GIC_V2M))
1078 		gicv2m_of_init(node, gic_data[gic_cnt].domain);
1079 
1080 	gic_cnt++;
1081 	return 0;
1082 }
1083 IRQCHIP_DECLARE(gic_400, "arm,gic-400", gic_of_init);
1084 IRQCHIP_DECLARE(arm11mp_gic, "arm,arm11mp-gic", gic_of_init);
1085 IRQCHIP_DECLARE(arm1176jzf_dc_gic, "arm,arm1176jzf-devchip-gic", gic_of_init);
1086 IRQCHIP_DECLARE(cortex_a15_gic, "arm,cortex-a15-gic", gic_of_init);
1087 IRQCHIP_DECLARE(cortex_a9_gic, "arm,cortex-a9-gic", gic_of_init);
1088 IRQCHIP_DECLARE(cortex_a7_gic, "arm,cortex-a7-gic", gic_of_init);
1089 IRQCHIP_DECLARE(msm_8660_qgic, "qcom,msm-8660-qgic", gic_of_init);
1090 IRQCHIP_DECLARE(msm_qgic2, "qcom,msm-qgic2", gic_of_init);
1091 
1092 #endif
1093