xref: /linux/drivers/irqchip/irq-gic.c (revision 3932b9ca55b0be314a36d3e84faff3e823c081f5)
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 *__this_cpu_ptr(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 
158 	raw_spin_lock(&irq_controller_lock);
159 	writel_relaxed(mask, gic_dist_base(d) + GIC_DIST_ENABLE_CLEAR + (gic_irq(d) / 32) * 4);
160 	if (gic_arch_extn.irq_mask)
161 		gic_arch_extn.irq_mask(d);
162 	raw_spin_unlock(&irq_controller_lock);
163 }
164 
165 static void gic_unmask_irq(struct irq_data *d)
166 {
167 	u32 mask = 1 << (gic_irq(d) % 32);
168 
169 	raw_spin_lock(&irq_controller_lock);
170 	if (gic_arch_extn.irq_unmask)
171 		gic_arch_extn.irq_unmask(d);
172 	writel_relaxed(mask, gic_dist_base(d) + GIC_DIST_ENABLE_SET + (gic_irq(d) / 32) * 4);
173 	raw_spin_unlock(&irq_controller_lock);
174 }
175 
176 static void gic_eoi_irq(struct irq_data *d)
177 {
178 	if (gic_arch_extn.irq_eoi) {
179 		raw_spin_lock(&irq_controller_lock);
180 		gic_arch_extn.irq_eoi(d);
181 		raw_spin_unlock(&irq_controller_lock);
182 	}
183 
184 	writel_relaxed(gic_irq(d), gic_cpu_base(d) + GIC_CPU_EOI);
185 }
186 
187 static int gic_set_type(struct irq_data *d, unsigned int type)
188 {
189 	void __iomem *base = gic_dist_base(d);
190 	unsigned int gicirq = gic_irq(d);
191 
192 	/* Interrupt configuration for SGIs can't be changed */
193 	if (gicirq < 16)
194 		return -EINVAL;
195 
196 	if (type != IRQ_TYPE_LEVEL_HIGH && type != IRQ_TYPE_EDGE_RISING)
197 		return -EINVAL;
198 
199 	raw_spin_lock(&irq_controller_lock);
200 
201 	if (gic_arch_extn.irq_set_type)
202 		gic_arch_extn.irq_set_type(d, type);
203 
204 	gic_configure_irq(gicirq, type, base, NULL);
205 
206 	raw_spin_unlock(&irq_controller_lock);
207 
208 	return 0;
209 }
210 
211 static int gic_retrigger(struct irq_data *d)
212 {
213 	if (gic_arch_extn.irq_retrigger)
214 		return gic_arch_extn.irq_retrigger(d);
215 
216 	/* the genirq layer expects 0 if we can't retrigger in hardware */
217 	return 0;
218 }
219 
220 #ifdef CONFIG_SMP
221 static int gic_set_affinity(struct irq_data *d, const struct cpumask *mask_val,
222 			    bool force)
223 {
224 	void __iomem *reg = gic_dist_base(d) + GIC_DIST_TARGET + (gic_irq(d) & ~3);
225 	unsigned int cpu, shift = (gic_irq(d) % 4) * 8;
226 	u32 val, mask, bit;
227 
228 	if (!force)
229 		cpu = cpumask_any_and(mask_val, cpu_online_mask);
230 	else
231 		cpu = cpumask_first(mask_val);
232 
233 	if (cpu >= NR_GIC_CPU_IF || cpu >= nr_cpu_ids)
234 		return -EINVAL;
235 
236 	raw_spin_lock(&irq_controller_lock);
237 	mask = 0xff << shift;
238 	bit = gic_cpu_map[cpu] << shift;
239 	val = readl_relaxed(reg) & ~mask;
240 	writel_relaxed(val | bit, reg);
241 	raw_spin_unlock(&irq_controller_lock);
242 
243 	return IRQ_SET_MASK_OK;
244 }
245 #endif
246 
247 #ifdef CONFIG_PM
248 static int gic_set_wake(struct irq_data *d, unsigned int on)
249 {
250 	int ret = -ENXIO;
251 
252 	if (gic_arch_extn.irq_set_wake)
253 		ret = gic_arch_extn.irq_set_wake(d, on);
254 
255 	return ret;
256 }
257 
258 #else
259 #define gic_set_wake	NULL
260 #endif
261 
262 static void __exception_irq_entry gic_handle_irq(struct pt_regs *regs)
263 {
264 	u32 irqstat, irqnr;
265 	struct gic_chip_data *gic = &gic_data[0];
266 	void __iomem *cpu_base = gic_data_cpu_base(gic);
267 
268 	do {
269 		irqstat = readl_relaxed(cpu_base + GIC_CPU_INTACK);
270 		irqnr = irqstat & GICC_IAR_INT_ID_MASK;
271 
272 		if (likely(irqnr > 15 && irqnr < 1021)) {
273 			irqnr = irq_find_mapping(gic->domain, irqnr);
274 			handle_IRQ(irqnr, regs);
275 			continue;
276 		}
277 		if (irqnr < 16) {
278 			writel_relaxed(irqstat, cpu_base + GIC_CPU_EOI);
279 #ifdef CONFIG_SMP
280 			handle_IPI(irqnr, regs);
281 #endif
282 			continue;
283 		}
284 		break;
285 	} while (1);
286 }
287 
288 static void gic_handle_cascade_irq(unsigned int irq, struct irq_desc *desc)
289 {
290 	struct gic_chip_data *chip_data = irq_get_handler_data(irq);
291 	struct irq_chip *chip = irq_get_chip(irq);
292 	unsigned int cascade_irq, gic_irq;
293 	unsigned long status;
294 
295 	chained_irq_enter(chip, desc);
296 
297 	raw_spin_lock(&irq_controller_lock);
298 	status = readl_relaxed(gic_data_cpu_base(chip_data) + GIC_CPU_INTACK);
299 	raw_spin_unlock(&irq_controller_lock);
300 
301 	gic_irq = (status & 0x3ff);
302 	if (gic_irq == 1023)
303 		goto out;
304 
305 	cascade_irq = irq_find_mapping(chip_data->domain, gic_irq);
306 	if (unlikely(gic_irq < 32 || gic_irq > 1020))
307 		handle_bad_irq(cascade_irq, desc);
308 	else
309 		generic_handle_irq(cascade_irq);
310 
311  out:
312 	chained_irq_exit(chip, desc);
313 }
314 
315 static struct irq_chip gic_chip = {
316 	.name			= "GIC",
317 	.irq_mask		= gic_mask_irq,
318 	.irq_unmask		= gic_unmask_irq,
319 	.irq_eoi		= gic_eoi_irq,
320 	.irq_set_type		= gic_set_type,
321 	.irq_retrigger		= gic_retrigger,
322 #ifdef CONFIG_SMP
323 	.irq_set_affinity	= gic_set_affinity,
324 #endif
325 	.irq_set_wake		= gic_set_wake,
326 };
327 
328 void __init gic_cascade_irq(unsigned int gic_nr, unsigned int irq)
329 {
330 	if (gic_nr >= MAX_GIC_NR)
331 		BUG();
332 	if (irq_set_handler_data(irq, &gic_data[gic_nr]) != 0)
333 		BUG();
334 	irq_set_chained_handler(irq, gic_handle_cascade_irq);
335 }
336 
337 static u8 gic_get_cpumask(struct gic_chip_data *gic)
338 {
339 	void __iomem *base = gic_data_dist_base(gic);
340 	u32 mask, i;
341 
342 	for (i = mask = 0; i < 32; i += 4) {
343 		mask = readl_relaxed(base + GIC_DIST_TARGET + i);
344 		mask |= mask >> 16;
345 		mask |= mask >> 8;
346 		if (mask)
347 			break;
348 	}
349 
350 	if (!mask)
351 		pr_crit("GIC CPU mask not found - kernel will fail to boot.\n");
352 
353 	return mask;
354 }
355 
356 static void __init gic_dist_init(struct gic_chip_data *gic)
357 {
358 	unsigned int i;
359 	u32 cpumask;
360 	unsigned int gic_irqs = gic->gic_irqs;
361 	void __iomem *base = gic_data_dist_base(gic);
362 
363 	writel_relaxed(0, base + GIC_DIST_CTRL);
364 
365 	/*
366 	 * Set all global interrupts to this CPU only.
367 	 */
368 	cpumask = gic_get_cpumask(gic);
369 	cpumask |= cpumask << 8;
370 	cpumask |= cpumask << 16;
371 	for (i = 32; i < gic_irqs; i += 4)
372 		writel_relaxed(cpumask, base + GIC_DIST_TARGET + i * 4 / 4);
373 
374 	gic_dist_config(base, gic_irqs, NULL);
375 
376 	writel_relaxed(1, base + GIC_DIST_CTRL);
377 }
378 
379 static void gic_cpu_init(struct gic_chip_data *gic)
380 {
381 	void __iomem *dist_base = gic_data_dist_base(gic);
382 	void __iomem *base = gic_data_cpu_base(gic);
383 	unsigned int cpu_mask, cpu = smp_processor_id();
384 	int i;
385 
386 	/*
387 	 * Get what the GIC says our CPU mask is.
388 	 */
389 	BUG_ON(cpu >= NR_GIC_CPU_IF);
390 	cpu_mask = gic_get_cpumask(gic);
391 	gic_cpu_map[cpu] = cpu_mask;
392 
393 	/*
394 	 * Clear our mask from the other map entries in case they're
395 	 * still undefined.
396 	 */
397 	for (i = 0; i < NR_GIC_CPU_IF; i++)
398 		if (i != cpu)
399 			gic_cpu_map[i] &= ~cpu_mask;
400 
401 	gic_cpu_config(dist_base, NULL);
402 
403 	writel_relaxed(0xf0, base + GIC_CPU_PRIMASK);
404 	writel_relaxed(1, base + GIC_CPU_CTRL);
405 }
406 
407 void gic_cpu_if_down(void)
408 {
409 	void __iomem *cpu_base = gic_data_cpu_base(&gic_data[0]);
410 	writel_relaxed(0, cpu_base + GIC_CPU_CTRL);
411 }
412 
413 #ifdef CONFIG_CPU_PM
414 /*
415  * Saves the GIC distributor registers during suspend or idle.  Must be called
416  * with interrupts disabled but before powering down the GIC.  After calling
417  * this function, no interrupts will be delivered by the GIC, and another
418  * platform-specific wakeup source must be enabled.
419  */
420 static void gic_dist_save(unsigned int gic_nr)
421 {
422 	unsigned int gic_irqs;
423 	void __iomem *dist_base;
424 	int i;
425 
426 	if (gic_nr >= MAX_GIC_NR)
427 		BUG();
428 
429 	gic_irqs = gic_data[gic_nr].gic_irqs;
430 	dist_base = gic_data_dist_base(&gic_data[gic_nr]);
431 
432 	if (!dist_base)
433 		return;
434 
435 	for (i = 0; i < DIV_ROUND_UP(gic_irqs, 16); i++)
436 		gic_data[gic_nr].saved_spi_conf[i] =
437 			readl_relaxed(dist_base + GIC_DIST_CONFIG + i * 4);
438 
439 	for (i = 0; i < DIV_ROUND_UP(gic_irqs, 4); i++)
440 		gic_data[gic_nr].saved_spi_target[i] =
441 			readl_relaxed(dist_base + GIC_DIST_TARGET + i * 4);
442 
443 	for (i = 0; i < DIV_ROUND_UP(gic_irqs, 32); i++)
444 		gic_data[gic_nr].saved_spi_enable[i] =
445 			readl_relaxed(dist_base + GIC_DIST_ENABLE_SET + i * 4);
446 }
447 
448 /*
449  * Restores the GIC distributor registers during resume or when coming out of
450  * idle.  Must be called before enabling interrupts.  If a level interrupt
451  * that occured while the GIC was suspended is still present, it will be
452  * handled normally, but any edge interrupts that occured will not be seen by
453  * the GIC and need to be handled by the platform-specific wakeup source.
454  */
455 static void gic_dist_restore(unsigned int gic_nr)
456 {
457 	unsigned int gic_irqs;
458 	unsigned int i;
459 	void __iomem *dist_base;
460 
461 	if (gic_nr >= MAX_GIC_NR)
462 		BUG();
463 
464 	gic_irqs = gic_data[gic_nr].gic_irqs;
465 	dist_base = gic_data_dist_base(&gic_data[gic_nr]);
466 
467 	if (!dist_base)
468 		return;
469 
470 	writel_relaxed(0, dist_base + GIC_DIST_CTRL);
471 
472 	for (i = 0; i < DIV_ROUND_UP(gic_irqs, 16); i++)
473 		writel_relaxed(gic_data[gic_nr].saved_spi_conf[i],
474 			dist_base + GIC_DIST_CONFIG + i * 4);
475 
476 	for (i = 0; i < DIV_ROUND_UP(gic_irqs, 4); i++)
477 		writel_relaxed(0xa0a0a0a0,
478 			dist_base + GIC_DIST_PRI + i * 4);
479 
480 	for (i = 0; i < DIV_ROUND_UP(gic_irqs, 4); i++)
481 		writel_relaxed(gic_data[gic_nr].saved_spi_target[i],
482 			dist_base + GIC_DIST_TARGET + i * 4);
483 
484 	for (i = 0; i < DIV_ROUND_UP(gic_irqs, 32); i++)
485 		writel_relaxed(gic_data[gic_nr].saved_spi_enable[i],
486 			dist_base + GIC_DIST_ENABLE_SET + i * 4);
487 
488 	writel_relaxed(1, dist_base + GIC_DIST_CTRL);
489 }
490 
491 static void gic_cpu_save(unsigned int gic_nr)
492 {
493 	int i;
494 	u32 *ptr;
495 	void __iomem *dist_base;
496 	void __iomem *cpu_base;
497 
498 	if (gic_nr >= MAX_GIC_NR)
499 		BUG();
500 
501 	dist_base = gic_data_dist_base(&gic_data[gic_nr]);
502 	cpu_base = gic_data_cpu_base(&gic_data[gic_nr]);
503 
504 	if (!dist_base || !cpu_base)
505 		return;
506 
507 	ptr = __this_cpu_ptr(gic_data[gic_nr].saved_ppi_enable);
508 	for (i = 0; i < DIV_ROUND_UP(32, 32); i++)
509 		ptr[i] = readl_relaxed(dist_base + GIC_DIST_ENABLE_SET + i * 4);
510 
511 	ptr = __this_cpu_ptr(gic_data[gic_nr].saved_ppi_conf);
512 	for (i = 0; i < DIV_ROUND_UP(32, 16); i++)
513 		ptr[i] = readl_relaxed(dist_base + GIC_DIST_CONFIG + i * 4);
514 
515 }
516 
517 static void gic_cpu_restore(unsigned int gic_nr)
518 {
519 	int i;
520 	u32 *ptr;
521 	void __iomem *dist_base;
522 	void __iomem *cpu_base;
523 
524 	if (gic_nr >= MAX_GIC_NR)
525 		BUG();
526 
527 	dist_base = gic_data_dist_base(&gic_data[gic_nr]);
528 	cpu_base = gic_data_cpu_base(&gic_data[gic_nr]);
529 
530 	if (!dist_base || !cpu_base)
531 		return;
532 
533 	ptr = __this_cpu_ptr(gic_data[gic_nr].saved_ppi_enable);
534 	for (i = 0; i < DIV_ROUND_UP(32, 32); i++)
535 		writel_relaxed(ptr[i], dist_base + GIC_DIST_ENABLE_SET + i * 4);
536 
537 	ptr = __this_cpu_ptr(gic_data[gic_nr].saved_ppi_conf);
538 	for (i = 0; i < DIV_ROUND_UP(32, 16); i++)
539 		writel_relaxed(ptr[i], dist_base + GIC_DIST_CONFIG + i * 4);
540 
541 	for (i = 0; i < DIV_ROUND_UP(32, 4); i++)
542 		writel_relaxed(0xa0a0a0a0, dist_base + GIC_DIST_PRI + i * 4);
543 
544 	writel_relaxed(0xf0, cpu_base + GIC_CPU_PRIMASK);
545 	writel_relaxed(1, cpu_base + GIC_CPU_CTRL);
546 }
547 
548 static int gic_notifier(struct notifier_block *self, unsigned long cmd,	void *v)
549 {
550 	int i;
551 
552 	for (i = 0; i < MAX_GIC_NR; i++) {
553 #ifdef CONFIG_GIC_NON_BANKED
554 		/* Skip over unused GICs */
555 		if (!gic_data[i].get_base)
556 			continue;
557 #endif
558 		switch (cmd) {
559 		case CPU_PM_ENTER:
560 			gic_cpu_save(i);
561 			break;
562 		case CPU_PM_ENTER_FAILED:
563 		case CPU_PM_EXIT:
564 			gic_cpu_restore(i);
565 			break;
566 		case CPU_CLUSTER_PM_ENTER:
567 			gic_dist_save(i);
568 			break;
569 		case CPU_CLUSTER_PM_ENTER_FAILED:
570 		case CPU_CLUSTER_PM_EXIT:
571 			gic_dist_restore(i);
572 			break;
573 		}
574 	}
575 
576 	return NOTIFY_OK;
577 }
578 
579 static struct notifier_block gic_notifier_block = {
580 	.notifier_call = gic_notifier,
581 };
582 
583 static void __init gic_pm_init(struct gic_chip_data *gic)
584 {
585 	gic->saved_ppi_enable = __alloc_percpu(DIV_ROUND_UP(32, 32) * 4,
586 		sizeof(u32));
587 	BUG_ON(!gic->saved_ppi_enable);
588 
589 	gic->saved_ppi_conf = __alloc_percpu(DIV_ROUND_UP(32, 16) * 4,
590 		sizeof(u32));
591 	BUG_ON(!gic->saved_ppi_conf);
592 
593 	if (gic == &gic_data[0])
594 		cpu_pm_register_notifier(&gic_notifier_block);
595 }
596 #else
597 static void __init gic_pm_init(struct gic_chip_data *gic)
598 {
599 }
600 #endif
601 
602 #ifdef CONFIG_SMP
603 static void gic_raise_softirq(const struct cpumask *mask, unsigned int irq)
604 {
605 	int cpu;
606 	unsigned long flags, map = 0;
607 
608 	raw_spin_lock_irqsave(&irq_controller_lock, flags);
609 
610 	/* Convert our logical CPU mask into a physical one. */
611 	for_each_cpu(cpu, mask)
612 		map |= gic_cpu_map[cpu];
613 
614 	/*
615 	 * Ensure that stores to Normal memory are visible to the
616 	 * other CPUs before they observe us issuing the IPI.
617 	 */
618 	dmb(ishst);
619 
620 	/* this always happens on GIC0 */
621 	writel_relaxed(map << 16 | irq, gic_data_dist_base(&gic_data[0]) + GIC_DIST_SOFTINT);
622 
623 	raw_spin_unlock_irqrestore(&irq_controller_lock, flags);
624 }
625 #endif
626 
627 #ifdef CONFIG_BL_SWITCHER
628 /*
629  * gic_send_sgi - send a SGI directly to given CPU interface number
630  *
631  * cpu_id: the ID for the destination CPU interface
632  * irq: the IPI number to send a SGI for
633  */
634 void gic_send_sgi(unsigned int cpu_id, unsigned int irq)
635 {
636 	BUG_ON(cpu_id >= NR_GIC_CPU_IF);
637 	cpu_id = 1 << cpu_id;
638 	/* this always happens on GIC0 */
639 	writel_relaxed((cpu_id << 16) | irq, gic_data_dist_base(&gic_data[0]) + GIC_DIST_SOFTINT);
640 }
641 
642 /*
643  * gic_get_cpu_id - get the CPU interface ID for the specified CPU
644  *
645  * @cpu: the logical CPU number to get the GIC ID for.
646  *
647  * Return the CPU interface ID for the given logical CPU number,
648  * or -1 if the CPU number is too large or the interface ID is
649  * unknown (more than one bit set).
650  */
651 int gic_get_cpu_id(unsigned int cpu)
652 {
653 	unsigned int cpu_bit;
654 
655 	if (cpu >= NR_GIC_CPU_IF)
656 		return -1;
657 	cpu_bit = gic_cpu_map[cpu];
658 	if (cpu_bit & (cpu_bit - 1))
659 		return -1;
660 	return __ffs(cpu_bit);
661 }
662 
663 /*
664  * gic_migrate_target - migrate IRQs to another CPU interface
665  *
666  * @new_cpu_id: the CPU target ID to migrate IRQs to
667  *
668  * Migrate all peripheral interrupts with a target matching the current CPU
669  * to the interface corresponding to @new_cpu_id.  The CPU interface mapping
670  * is also updated.  Targets to other CPU interfaces are unchanged.
671  * This must be called with IRQs locally disabled.
672  */
673 void gic_migrate_target(unsigned int new_cpu_id)
674 {
675 	unsigned int cur_cpu_id, gic_irqs, gic_nr = 0;
676 	void __iomem *dist_base;
677 	int i, ror_val, cpu = smp_processor_id();
678 	u32 val, cur_target_mask, active_mask;
679 
680 	if (gic_nr >= MAX_GIC_NR)
681 		BUG();
682 
683 	dist_base = gic_data_dist_base(&gic_data[gic_nr]);
684 	if (!dist_base)
685 		return;
686 	gic_irqs = gic_data[gic_nr].gic_irqs;
687 
688 	cur_cpu_id = __ffs(gic_cpu_map[cpu]);
689 	cur_target_mask = 0x01010101 << cur_cpu_id;
690 	ror_val = (cur_cpu_id - new_cpu_id) & 31;
691 
692 	raw_spin_lock(&irq_controller_lock);
693 
694 	/* Update the target interface for this logical CPU */
695 	gic_cpu_map[cpu] = 1 << new_cpu_id;
696 
697 	/*
698 	 * Find all the peripheral interrupts targetting the current
699 	 * CPU interface and migrate them to the new CPU interface.
700 	 * We skip DIST_TARGET 0 to 7 as they are read-only.
701 	 */
702 	for (i = 8; i < DIV_ROUND_UP(gic_irqs, 4); i++) {
703 		val = readl_relaxed(dist_base + GIC_DIST_TARGET + i * 4);
704 		active_mask = val & cur_target_mask;
705 		if (active_mask) {
706 			val &= ~active_mask;
707 			val |= ror32(active_mask, ror_val);
708 			writel_relaxed(val, dist_base + GIC_DIST_TARGET + i*4);
709 		}
710 	}
711 
712 	raw_spin_unlock(&irq_controller_lock);
713 
714 	/*
715 	 * Now let's migrate and clear any potential SGIs that might be
716 	 * pending for us (cur_cpu_id).  Since GIC_DIST_SGI_PENDING_SET
717 	 * is a banked register, we can only forward the SGI using
718 	 * GIC_DIST_SOFTINT.  The original SGI source is lost but Linux
719 	 * doesn't use that information anyway.
720 	 *
721 	 * For the same reason we do not adjust SGI source information
722 	 * for previously sent SGIs by us to other CPUs either.
723 	 */
724 	for (i = 0; i < 16; i += 4) {
725 		int j;
726 		val = readl_relaxed(dist_base + GIC_DIST_SGI_PENDING_SET + i);
727 		if (!val)
728 			continue;
729 		writel_relaxed(val, dist_base + GIC_DIST_SGI_PENDING_CLEAR + i);
730 		for (j = i; j < i + 4; j++) {
731 			if (val & 0xff)
732 				writel_relaxed((1 << (new_cpu_id + 16)) | j,
733 						dist_base + GIC_DIST_SOFTINT);
734 			val >>= 8;
735 		}
736 	}
737 }
738 
739 /*
740  * gic_get_sgir_physaddr - get the physical address for the SGI register
741  *
742  * REturn the physical address of the SGI register to be used
743  * by some early assembly code when the kernel is not yet available.
744  */
745 static unsigned long gic_dist_physaddr;
746 
747 unsigned long gic_get_sgir_physaddr(void)
748 {
749 	if (!gic_dist_physaddr)
750 		return 0;
751 	return gic_dist_physaddr + GIC_DIST_SOFTINT;
752 }
753 
754 void __init gic_init_physaddr(struct device_node *node)
755 {
756 	struct resource res;
757 	if (of_address_to_resource(node, 0, &res) == 0) {
758 		gic_dist_physaddr = res.start;
759 		pr_info("GIC physical location is %#lx\n", gic_dist_physaddr);
760 	}
761 }
762 
763 #else
764 #define gic_init_physaddr(node)  do { } while (0)
765 #endif
766 
767 static int gic_irq_domain_map(struct irq_domain *d, unsigned int irq,
768 				irq_hw_number_t hw)
769 {
770 	if (hw < 32) {
771 		irq_set_percpu_devid(irq);
772 		irq_set_chip_and_handler(irq, &gic_chip,
773 					 handle_percpu_devid_irq);
774 		set_irq_flags(irq, IRQF_VALID | IRQF_NOAUTOEN);
775 	} else {
776 		irq_set_chip_and_handler(irq, &gic_chip,
777 					 handle_fasteoi_irq);
778 		set_irq_flags(irq, IRQF_VALID | IRQF_PROBE);
779 
780 		gic_routable_irq_domain_ops->map(d, irq, hw);
781 	}
782 	irq_set_chip_data(irq, d->host_data);
783 	return 0;
784 }
785 
786 static void gic_irq_domain_unmap(struct irq_domain *d, unsigned int irq)
787 {
788 	gic_routable_irq_domain_ops->unmap(d, irq);
789 }
790 
791 static int gic_irq_domain_xlate(struct irq_domain *d,
792 				struct device_node *controller,
793 				const u32 *intspec, unsigned int intsize,
794 				unsigned long *out_hwirq, unsigned int *out_type)
795 {
796 	unsigned long ret = 0;
797 
798 	if (d->of_node != controller)
799 		return -EINVAL;
800 	if (intsize < 3)
801 		return -EINVAL;
802 
803 	/* Get the interrupt number and add 16 to skip over SGIs */
804 	*out_hwirq = intspec[1] + 16;
805 
806 	/* For SPIs, we need to add 16 more to get the GIC irq ID number */
807 	if (!intspec[0]) {
808 		ret = gic_routable_irq_domain_ops->xlate(d, controller,
809 							 intspec,
810 							 intsize,
811 							 out_hwirq,
812 							 out_type);
813 
814 		if (IS_ERR_VALUE(ret))
815 			return ret;
816 	}
817 
818 	*out_type = intspec[2] & IRQ_TYPE_SENSE_MASK;
819 
820 	return ret;
821 }
822 
823 #ifdef CONFIG_SMP
824 static int gic_secondary_init(struct notifier_block *nfb, unsigned long action,
825 			      void *hcpu)
826 {
827 	if (action == CPU_STARTING || action == CPU_STARTING_FROZEN)
828 		gic_cpu_init(&gic_data[0]);
829 	return NOTIFY_OK;
830 }
831 
832 /*
833  * Notifier for enabling the GIC CPU interface. Set an arbitrarily high
834  * priority because the GIC needs to be up before the ARM generic timers.
835  */
836 static struct notifier_block gic_cpu_notifier = {
837 	.notifier_call = gic_secondary_init,
838 	.priority = 100,
839 };
840 #endif
841 
842 static const struct irq_domain_ops gic_irq_domain_ops = {
843 	.map = gic_irq_domain_map,
844 	.unmap = gic_irq_domain_unmap,
845 	.xlate = gic_irq_domain_xlate,
846 };
847 
848 /* Default functions for routable irq domain */
849 static int gic_routable_irq_domain_map(struct irq_domain *d, unsigned int irq,
850 			      irq_hw_number_t hw)
851 {
852 	return 0;
853 }
854 
855 static void gic_routable_irq_domain_unmap(struct irq_domain *d,
856 					  unsigned int irq)
857 {
858 }
859 
860 static int gic_routable_irq_domain_xlate(struct irq_domain *d,
861 				struct device_node *controller,
862 				const u32 *intspec, unsigned int intsize,
863 				unsigned long *out_hwirq,
864 				unsigned int *out_type)
865 {
866 	*out_hwirq += 16;
867 	return 0;
868 }
869 
870 static const struct irq_domain_ops gic_default_routable_irq_domain_ops = {
871 	.map = gic_routable_irq_domain_map,
872 	.unmap = gic_routable_irq_domain_unmap,
873 	.xlate = gic_routable_irq_domain_xlate,
874 };
875 
876 const struct irq_domain_ops *gic_routable_irq_domain_ops =
877 					&gic_default_routable_irq_domain_ops;
878 
879 void __init gic_init_bases(unsigned int gic_nr, int irq_start,
880 			   void __iomem *dist_base, void __iomem *cpu_base,
881 			   u32 percpu_offset, struct device_node *node)
882 {
883 	irq_hw_number_t hwirq_base;
884 	struct gic_chip_data *gic;
885 	int gic_irqs, irq_base, i;
886 	int nr_routable_irqs;
887 
888 	BUG_ON(gic_nr >= MAX_GIC_NR);
889 
890 	gic = &gic_data[gic_nr];
891 #ifdef CONFIG_GIC_NON_BANKED
892 	if (percpu_offset) { /* Frankein-GIC without banked registers... */
893 		unsigned int cpu;
894 
895 		gic->dist_base.percpu_base = alloc_percpu(void __iomem *);
896 		gic->cpu_base.percpu_base = alloc_percpu(void __iomem *);
897 		if (WARN_ON(!gic->dist_base.percpu_base ||
898 			    !gic->cpu_base.percpu_base)) {
899 			free_percpu(gic->dist_base.percpu_base);
900 			free_percpu(gic->cpu_base.percpu_base);
901 			return;
902 		}
903 
904 		for_each_possible_cpu(cpu) {
905 			u32 mpidr = cpu_logical_map(cpu);
906 			u32 core_id = MPIDR_AFFINITY_LEVEL(mpidr, 0);
907 			unsigned long offset = percpu_offset * core_id;
908 			*per_cpu_ptr(gic->dist_base.percpu_base, cpu) = dist_base + offset;
909 			*per_cpu_ptr(gic->cpu_base.percpu_base, cpu) = cpu_base + offset;
910 		}
911 
912 		gic_set_base_accessor(gic, gic_get_percpu_base);
913 	} else
914 #endif
915 	{			/* Normal, sane GIC... */
916 		WARN(percpu_offset,
917 		     "GIC_NON_BANKED not enabled, ignoring %08x offset!",
918 		     percpu_offset);
919 		gic->dist_base.common_base = dist_base;
920 		gic->cpu_base.common_base = cpu_base;
921 		gic_set_base_accessor(gic, gic_get_common_base);
922 	}
923 
924 	/*
925 	 * Initialize the CPU interface map to all CPUs.
926 	 * It will be refined as each CPU probes its ID.
927 	 */
928 	for (i = 0; i < NR_GIC_CPU_IF; i++)
929 		gic_cpu_map[i] = 0xff;
930 
931 	/*
932 	 * For primary GICs, skip over SGIs.
933 	 * For secondary GICs, skip over PPIs, too.
934 	 */
935 	if (gic_nr == 0 && (irq_start & 31) > 0) {
936 		hwirq_base = 16;
937 		if (irq_start != -1)
938 			irq_start = (irq_start & ~31) + 16;
939 	} else {
940 		hwirq_base = 32;
941 	}
942 
943 	/*
944 	 * Find out how many interrupts are supported.
945 	 * The GIC only supports up to 1020 interrupt sources.
946 	 */
947 	gic_irqs = readl_relaxed(gic_data_dist_base(gic) + GIC_DIST_CTR) & 0x1f;
948 	gic_irqs = (gic_irqs + 1) * 32;
949 	if (gic_irqs > 1020)
950 		gic_irqs = 1020;
951 	gic->gic_irqs = gic_irqs;
952 
953 	gic_irqs -= hwirq_base; /* calculate # of irqs to allocate */
954 
955 	if (of_property_read_u32(node, "arm,routable-irqs",
956 				 &nr_routable_irqs)) {
957 		irq_base = irq_alloc_descs(irq_start, 16, gic_irqs,
958 					   numa_node_id());
959 		if (IS_ERR_VALUE(irq_base)) {
960 			WARN(1, "Cannot allocate irq_descs @ IRQ%d, assuming pre-allocated\n",
961 			     irq_start);
962 			irq_base = irq_start;
963 		}
964 
965 		gic->domain = irq_domain_add_legacy(node, gic_irqs, irq_base,
966 					hwirq_base, &gic_irq_domain_ops, gic);
967 	} else {
968 		gic->domain = irq_domain_add_linear(node, nr_routable_irqs,
969 						    &gic_irq_domain_ops,
970 						    gic);
971 	}
972 
973 	if (WARN_ON(!gic->domain))
974 		return;
975 
976 	if (gic_nr == 0) {
977 #ifdef CONFIG_SMP
978 		set_smp_cross_call(gic_raise_softirq);
979 		register_cpu_notifier(&gic_cpu_notifier);
980 #endif
981 		set_handle_irq(gic_handle_irq);
982 	}
983 
984 	gic_chip.flags |= gic_arch_extn.flags;
985 	gic_dist_init(gic);
986 	gic_cpu_init(gic);
987 	gic_pm_init(gic);
988 }
989 
990 #ifdef CONFIG_OF
991 static int gic_cnt __initdata;
992 
993 static int __init
994 gic_of_init(struct device_node *node, struct device_node *parent)
995 {
996 	void __iomem *cpu_base;
997 	void __iomem *dist_base;
998 	u32 percpu_offset;
999 	int irq;
1000 
1001 	if (WARN_ON(!node))
1002 		return -ENODEV;
1003 
1004 	dist_base = of_iomap(node, 0);
1005 	WARN(!dist_base, "unable to map gic dist registers\n");
1006 
1007 	cpu_base = of_iomap(node, 1);
1008 	WARN(!cpu_base, "unable to map gic cpu registers\n");
1009 
1010 	if (of_property_read_u32(node, "cpu-offset", &percpu_offset))
1011 		percpu_offset = 0;
1012 
1013 	gic_init_bases(gic_cnt, -1, dist_base, cpu_base, percpu_offset, node);
1014 	if (!gic_cnt)
1015 		gic_init_physaddr(node);
1016 
1017 	if (parent) {
1018 		irq = irq_of_parse_and_map(node, 0);
1019 		gic_cascade_irq(gic_cnt, irq);
1020 	}
1021 	gic_cnt++;
1022 	return 0;
1023 }
1024 IRQCHIP_DECLARE(gic_400, "arm,gic-400", gic_of_init);
1025 IRQCHIP_DECLARE(cortex_a15_gic, "arm,cortex-a15-gic", gic_of_init);
1026 IRQCHIP_DECLARE(cortex_a9_gic, "arm,cortex-a9-gic", gic_of_init);
1027 IRQCHIP_DECLARE(cortex_a7_gic, "arm,cortex-a7-gic", gic_of_init);
1028 IRQCHIP_DECLARE(msm_8660_qgic, "qcom,msm-8660-qgic", gic_of_init);
1029 IRQCHIP_DECLARE(msm_qgic2, "qcom,msm-qgic2", gic_of_init);
1030 
1031 #endif
1032