xref: /openbmc/linux/drivers/irqchip/irq-gic.c (revision bc000245)
1 /*
2  *  linux/arch/arm/common/gic.c
3  *
4  *  Copyright (C) 2002 ARM Limited, All Rights Reserved.
5  *
6  * This program is free software; you can redistribute it and/or modify
7  * it under the terms of the GNU General Public License version 2 as
8  * published by the Free Software Foundation.
9  *
10  * Interrupt architecture for the GIC:
11  *
12  * o There is one Interrupt Distributor, which receives interrupts
13  *   from system devices and sends them to the Interrupt Controllers.
14  *
15  * o There is one CPU Interface per CPU, which sends interrupts sent
16  *   by the Distributor, and interrupts generated locally, to the
17  *   associated CPU. The base address of the CPU interface is usually
18  *   aliased so that the same address points to different chips depending
19  *   on the CPU it is accessed from.
20  *
21  * Note that IRQs 0-31 are special - they are local to each CPU.
22  * As such, the enable set/clear, pending set/clear and active bit
23  * registers are banked per-cpu for these sources.
24  */
25 #include <linux/init.h>
26 #include <linux/kernel.h>
27 #include <linux/err.h>
28 #include <linux/module.h>
29 #include <linux/list.h>
30 #include <linux/smp.h>
31 #include <linux/cpu.h>
32 #include <linux/cpu_pm.h>
33 #include <linux/cpumask.h>
34 #include <linux/io.h>
35 #include <linux/of.h>
36 #include <linux/of_address.h>
37 #include <linux/of_irq.h>
38 #include <linux/irqdomain.h>
39 #include <linux/interrupt.h>
40 #include <linux/percpu.h>
41 #include <linux/slab.h>
42 #include <linux/irqchip/chained_irq.h>
43 #include <linux/irqchip/arm-gic.h>
44 
45 #include <asm/irq.h>
46 #include <asm/exception.h>
47 #include <asm/smp_plat.h>
48 
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 	u32 enablemask = 1 << (gicirq % 32);
192 	u32 enableoff = (gicirq / 32) * 4;
193 	u32 confmask = 0x2 << ((gicirq % 16) * 2);
194 	u32 confoff = (gicirq / 16) * 4;
195 	bool enabled = false;
196 	u32 val;
197 
198 	/* Interrupt configuration for SGIs can't be changed */
199 	if (gicirq < 16)
200 		return -EINVAL;
201 
202 	if (type != IRQ_TYPE_LEVEL_HIGH && type != IRQ_TYPE_EDGE_RISING)
203 		return -EINVAL;
204 
205 	raw_spin_lock(&irq_controller_lock);
206 
207 	if (gic_arch_extn.irq_set_type)
208 		gic_arch_extn.irq_set_type(d, type);
209 
210 	val = readl_relaxed(base + GIC_DIST_CONFIG + confoff);
211 	if (type == IRQ_TYPE_LEVEL_HIGH)
212 		val &= ~confmask;
213 	else if (type == IRQ_TYPE_EDGE_RISING)
214 		val |= confmask;
215 
216 	/*
217 	 * As recommended by the spec, disable the interrupt before changing
218 	 * the configuration
219 	 */
220 	if (readl_relaxed(base + GIC_DIST_ENABLE_SET + enableoff) & enablemask) {
221 		writel_relaxed(enablemask, base + GIC_DIST_ENABLE_CLEAR + enableoff);
222 		enabled = true;
223 	}
224 
225 	writel_relaxed(val, base + GIC_DIST_CONFIG + confoff);
226 
227 	if (enabled)
228 		writel_relaxed(enablemask, base + GIC_DIST_ENABLE_SET + enableoff);
229 
230 	raw_spin_unlock(&irq_controller_lock);
231 
232 	return 0;
233 }
234 
235 static int gic_retrigger(struct irq_data *d)
236 {
237 	if (gic_arch_extn.irq_retrigger)
238 		return gic_arch_extn.irq_retrigger(d);
239 
240 	/* the genirq layer expects 0 if we can't retrigger in hardware */
241 	return 0;
242 }
243 
244 #ifdef CONFIG_SMP
245 static int gic_set_affinity(struct irq_data *d, const struct cpumask *mask_val,
246 			    bool force)
247 {
248 	void __iomem *reg = gic_dist_base(d) + GIC_DIST_TARGET + (gic_irq(d) & ~3);
249 	unsigned int shift = (gic_irq(d) % 4) * 8;
250 	unsigned int cpu = cpumask_any_and(mask_val, cpu_online_mask);
251 	u32 val, mask, bit;
252 
253 	if (cpu >= NR_GIC_CPU_IF || cpu >= nr_cpu_ids)
254 		return -EINVAL;
255 
256 	raw_spin_lock(&irq_controller_lock);
257 	mask = 0xff << shift;
258 	bit = gic_cpu_map[cpu] << shift;
259 	val = readl_relaxed(reg) & ~mask;
260 	writel_relaxed(val | bit, reg);
261 	raw_spin_unlock(&irq_controller_lock);
262 
263 	return IRQ_SET_MASK_OK;
264 }
265 #endif
266 
267 #ifdef CONFIG_PM
268 static int gic_set_wake(struct irq_data *d, unsigned int on)
269 {
270 	int ret = -ENXIO;
271 
272 	if (gic_arch_extn.irq_set_wake)
273 		ret = gic_arch_extn.irq_set_wake(d, on);
274 
275 	return ret;
276 }
277 
278 #else
279 #define gic_set_wake	NULL
280 #endif
281 
282 static asmlinkage void __exception_irq_entry gic_handle_irq(struct pt_regs *regs)
283 {
284 	u32 irqstat, irqnr;
285 	struct gic_chip_data *gic = &gic_data[0];
286 	void __iomem *cpu_base = gic_data_cpu_base(gic);
287 
288 	do {
289 		irqstat = readl_relaxed(cpu_base + GIC_CPU_INTACK);
290 		irqnr = irqstat & ~0x1c00;
291 
292 		if (likely(irqnr > 15 && irqnr < 1021)) {
293 			irqnr = irq_find_mapping(gic->domain, irqnr);
294 			handle_IRQ(irqnr, regs);
295 			continue;
296 		}
297 		if (irqnr < 16) {
298 			writel_relaxed(irqstat, cpu_base + GIC_CPU_EOI);
299 #ifdef CONFIG_SMP
300 			handle_IPI(irqnr, regs);
301 #endif
302 			continue;
303 		}
304 		break;
305 	} while (1);
306 }
307 
308 static void gic_handle_cascade_irq(unsigned int irq, struct irq_desc *desc)
309 {
310 	struct gic_chip_data *chip_data = irq_get_handler_data(irq);
311 	struct irq_chip *chip = irq_get_chip(irq);
312 	unsigned int cascade_irq, gic_irq;
313 	unsigned long status;
314 
315 	chained_irq_enter(chip, desc);
316 
317 	raw_spin_lock(&irq_controller_lock);
318 	status = readl_relaxed(gic_data_cpu_base(chip_data) + GIC_CPU_INTACK);
319 	raw_spin_unlock(&irq_controller_lock);
320 
321 	gic_irq = (status & 0x3ff);
322 	if (gic_irq == 1023)
323 		goto out;
324 
325 	cascade_irq = irq_find_mapping(chip_data->domain, gic_irq);
326 	if (unlikely(gic_irq < 32 || gic_irq > 1020))
327 		handle_bad_irq(cascade_irq, desc);
328 	else
329 		generic_handle_irq(cascade_irq);
330 
331  out:
332 	chained_irq_exit(chip, desc);
333 }
334 
335 static struct irq_chip gic_chip = {
336 	.name			= "GIC",
337 	.irq_mask		= gic_mask_irq,
338 	.irq_unmask		= gic_unmask_irq,
339 	.irq_eoi		= gic_eoi_irq,
340 	.irq_set_type		= gic_set_type,
341 	.irq_retrigger		= gic_retrigger,
342 #ifdef CONFIG_SMP
343 	.irq_set_affinity	= gic_set_affinity,
344 #endif
345 	.irq_set_wake		= gic_set_wake,
346 };
347 
348 void __init gic_cascade_irq(unsigned int gic_nr, unsigned int irq)
349 {
350 	if (gic_nr >= MAX_GIC_NR)
351 		BUG();
352 	if (irq_set_handler_data(irq, &gic_data[gic_nr]) != 0)
353 		BUG();
354 	irq_set_chained_handler(irq, gic_handle_cascade_irq);
355 }
356 
357 static u8 gic_get_cpumask(struct gic_chip_data *gic)
358 {
359 	void __iomem *base = gic_data_dist_base(gic);
360 	u32 mask, i;
361 
362 	for (i = mask = 0; i < 32; i += 4) {
363 		mask = readl_relaxed(base + GIC_DIST_TARGET + i);
364 		mask |= mask >> 16;
365 		mask |= mask >> 8;
366 		if (mask)
367 			break;
368 	}
369 
370 	if (!mask)
371 		pr_crit("GIC CPU mask not found - kernel will fail to boot.\n");
372 
373 	return mask;
374 }
375 
376 static void __init gic_dist_init(struct gic_chip_data *gic)
377 {
378 	unsigned int i;
379 	u32 cpumask;
380 	unsigned int gic_irqs = gic->gic_irqs;
381 	void __iomem *base = gic_data_dist_base(gic);
382 
383 	writel_relaxed(0, base + GIC_DIST_CTRL);
384 
385 	/*
386 	 * Set all global interrupts to be level triggered, active low.
387 	 */
388 	for (i = 32; i < gic_irqs; i += 16)
389 		writel_relaxed(0, base + GIC_DIST_CONFIG + i * 4 / 16);
390 
391 	/*
392 	 * Set all global interrupts to this CPU only.
393 	 */
394 	cpumask = gic_get_cpumask(gic);
395 	cpumask |= cpumask << 8;
396 	cpumask |= cpumask << 16;
397 	for (i = 32; i < gic_irqs; i += 4)
398 		writel_relaxed(cpumask, base + GIC_DIST_TARGET + i * 4 / 4);
399 
400 	/*
401 	 * Set priority on all global interrupts.
402 	 */
403 	for (i = 32; i < gic_irqs; i += 4)
404 		writel_relaxed(0xa0a0a0a0, base + GIC_DIST_PRI + i * 4 / 4);
405 
406 	/*
407 	 * Disable all interrupts.  Leave the PPI and SGIs alone
408 	 * as these enables are banked registers.
409 	 */
410 	for (i = 32; i < gic_irqs; i += 32)
411 		writel_relaxed(0xffffffff, base + GIC_DIST_ENABLE_CLEAR + i * 4 / 32);
412 
413 	writel_relaxed(1, base + GIC_DIST_CTRL);
414 }
415 
416 static void gic_cpu_init(struct gic_chip_data *gic)
417 {
418 	void __iomem *dist_base = gic_data_dist_base(gic);
419 	void __iomem *base = gic_data_cpu_base(gic);
420 	unsigned int cpu_mask, cpu = smp_processor_id();
421 	int i;
422 
423 	/*
424 	 * Get what the GIC says our CPU mask is.
425 	 */
426 	BUG_ON(cpu >= NR_GIC_CPU_IF);
427 	cpu_mask = gic_get_cpumask(gic);
428 	gic_cpu_map[cpu] = cpu_mask;
429 
430 	/*
431 	 * Clear our mask from the other map entries in case they're
432 	 * still undefined.
433 	 */
434 	for (i = 0; i < NR_GIC_CPU_IF; i++)
435 		if (i != cpu)
436 			gic_cpu_map[i] &= ~cpu_mask;
437 
438 	/*
439 	 * Deal with the banked PPI and SGI interrupts - disable all
440 	 * PPI interrupts, ensure all SGI interrupts are enabled.
441 	 */
442 	writel_relaxed(0xffff0000, dist_base + GIC_DIST_ENABLE_CLEAR);
443 	writel_relaxed(0x0000ffff, dist_base + GIC_DIST_ENABLE_SET);
444 
445 	/*
446 	 * Set priority on PPI and SGI interrupts
447 	 */
448 	for (i = 0; i < 32; i += 4)
449 		writel_relaxed(0xa0a0a0a0, dist_base + GIC_DIST_PRI + i * 4 / 4);
450 
451 	writel_relaxed(0xf0, base + GIC_CPU_PRIMASK);
452 	writel_relaxed(1, base + GIC_CPU_CTRL);
453 }
454 
455 void gic_cpu_if_down(void)
456 {
457 	void __iomem *cpu_base = gic_data_cpu_base(&gic_data[0]);
458 	writel_relaxed(0, cpu_base + GIC_CPU_CTRL);
459 }
460 
461 #ifdef CONFIG_CPU_PM
462 /*
463  * Saves the GIC distributor registers during suspend or idle.  Must be called
464  * with interrupts disabled but before powering down the GIC.  After calling
465  * this function, no interrupts will be delivered by the GIC, and another
466  * platform-specific wakeup source must be enabled.
467  */
468 static void gic_dist_save(unsigned int gic_nr)
469 {
470 	unsigned int gic_irqs;
471 	void __iomem *dist_base;
472 	int i;
473 
474 	if (gic_nr >= MAX_GIC_NR)
475 		BUG();
476 
477 	gic_irqs = gic_data[gic_nr].gic_irqs;
478 	dist_base = gic_data_dist_base(&gic_data[gic_nr]);
479 
480 	if (!dist_base)
481 		return;
482 
483 	for (i = 0; i < DIV_ROUND_UP(gic_irqs, 16); i++)
484 		gic_data[gic_nr].saved_spi_conf[i] =
485 			readl_relaxed(dist_base + GIC_DIST_CONFIG + i * 4);
486 
487 	for (i = 0; i < DIV_ROUND_UP(gic_irqs, 4); i++)
488 		gic_data[gic_nr].saved_spi_target[i] =
489 			readl_relaxed(dist_base + GIC_DIST_TARGET + i * 4);
490 
491 	for (i = 0; i < DIV_ROUND_UP(gic_irqs, 32); i++)
492 		gic_data[gic_nr].saved_spi_enable[i] =
493 			readl_relaxed(dist_base + GIC_DIST_ENABLE_SET + i * 4);
494 }
495 
496 /*
497  * Restores the GIC distributor registers during resume or when coming out of
498  * idle.  Must be called before enabling interrupts.  If a level interrupt
499  * that occured while the GIC was suspended is still present, it will be
500  * handled normally, but any edge interrupts that occured will not be seen by
501  * the GIC and need to be handled by the platform-specific wakeup source.
502  */
503 static void gic_dist_restore(unsigned int gic_nr)
504 {
505 	unsigned int gic_irqs;
506 	unsigned int i;
507 	void __iomem *dist_base;
508 
509 	if (gic_nr >= MAX_GIC_NR)
510 		BUG();
511 
512 	gic_irqs = gic_data[gic_nr].gic_irqs;
513 	dist_base = gic_data_dist_base(&gic_data[gic_nr]);
514 
515 	if (!dist_base)
516 		return;
517 
518 	writel_relaxed(0, dist_base + GIC_DIST_CTRL);
519 
520 	for (i = 0; i < DIV_ROUND_UP(gic_irqs, 16); i++)
521 		writel_relaxed(gic_data[gic_nr].saved_spi_conf[i],
522 			dist_base + GIC_DIST_CONFIG + i * 4);
523 
524 	for (i = 0; i < DIV_ROUND_UP(gic_irqs, 4); i++)
525 		writel_relaxed(0xa0a0a0a0,
526 			dist_base + GIC_DIST_PRI + i * 4);
527 
528 	for (i = 0; i < DIV_ROUND_UP(gic_irqs, 4); i++)
529 		writel_relaxed(gic_data[gic_nr].saved_spi_target[i],
530 			dist_base + GIC_DIST_TARGET + i * 4);
531 
532 	for (i = 0; i < DIV_ROUND_UP(gic_irqs, 32); i++)
533 		writel_relaxed(gic_data[gic_nr].saved_spi_enable[i],
534 			dist_base + GIC_DIST_ENABLE_SET + i * 4);
535 
536 	writel_relaxed(1, dist_base + GIC_DIST_CTRL);
537 }
538 
539 static void gic_cpu_save(unsigned int gic_nr)
540 {
541 	int i;
542 	u32 *ptr;
543 	void __iomem *dist_base;
544 	void __iomem *cpu_base;
545 
546 	if (gic_nr >= MAX_GIC_NR)
547 		BUG();
548 
549 	dist_base = gic_data_dist_base(&gic_data[gic_nr]);
550 	cpu_base = gic_data_cpu_base(&gic_data[gic_nr]);
551 
552 	if (!dist_base || !cpu_base)
553 		return;
554 
555 	ptr = __this_cpu_ptr(gic_data[gic_nr].saved_ppi_enable);
556 	for (i = 0; i < DIV_ROUND_UP(32, 32); i++)
557 		ptr[i] = readl_relaxed(dist_base + GIC_DIST_ENABLE_SET + i * 4);
558 
559 	ptr = __this_cpu_ptr(gic_data[gic_nr].saved_ppi_conf);
560 	for (i = 0; i < DIV_ROUND_UP(32, 16); i++)
561 		ptr[i] = readl_relaxed(dist_base + GIC_DIST_CONFIG + i * 4);
562 
563 }
564 
565 static void gic_cpu_restore(unsigned int gic_nr)
566 {
567 	int i;
568 	u32 *ptr;
569 	void __iomem *dist_base;
570 	void __iomem *cpu_base;
571 
572 	if (gic_nr >= MAX_GIC_NR)
573 		BUG();
574 
575 	dist_base = gic_data_dist_base(&gic_data[gic_nr]);
576 	cpu_base = gic_data_cpu_base(&gic_data[gic_nr]);
577 
578 	if (!dist_base || !cpu_base)
579 		return;
580 
581 	ptr = __this_cpu_ptr(gic_data[gic_nr].saved_ppi_enable);
582 	for (i = 0; i < DIV_ROUND_UP(32, 32); i++)
583 		writel_relaxed(ptr[i], dist_base + GIC_DIST_ENABLE_SET + i * 4);
584 
585 	ptr = __this_cpu_ptr(gic_data[gic_nr].saved_ppi_conf);
586 	for (i = 0; i < DIV_ROUND_UP(32, 16); i++)
587 		writel_relaxed(ptr[i], dist_base + GIC_DIST_CONFIG + i * 4);
588 
589 	for (i = 0; i < DIV_ROUND_UP(32, 4); i++)
590 		writel_relaxed(0xa0a0a0a0, dist_base + GIC_DIST_PRI + i * 4);
591 
592 	writel_relaxed(0xf0, cpu_base + GIC_CPU_PRIMASK);
593 	writel_relaxed(1, cpu_base + GIC_CPU_CTRL);
594 }
595 
596 static int gic_notifier(struct notifier_block *self, unsigned long cmd,	void *v)
597 {
598 	int i;
599 
600 	for (i = 0; i < MAX_GIC_NR; i++) {
601 #ifdef CONFIG_GIC_NON_BANKED
602 		/* Skip over unused GICs */
603 		if (!gic_data[i].get_base)
604 			continue;
605 #endif
606 		switch (cmd) {
607 		case CPU_PM_ENTER:
608 			gic_cpu_save(i);
609 			break;
610 		case CPU_PM_ENTER_FAILED:
611 		case CPU_PM_EXIT:
612 			gic_cpu_restore(i);
613 			break;
614 		case CPU_CLUSTER_PM_ENTER:
615 			gic_dist_save(i);
616 			break;
617 		case CPU_CLUSTER_PM_ENTER_FAILED:
618 		case CPU_CLUSTER_PM_EXIT:
619 			gic_dist_restore(i);
620 			break;
621 		}
622 	}
623 
624 	return NOTIFY_OK;
625 }
626 
627 static struct notifier_block gic_notifier_block = {
628 	.notifier_call = gic_notifier,
629 };
630 
631 static void __init gic_pm_init(struct gic_chip_data *gic)
632 {
633 	gic->saved_ppi_enable = __alloc_percpu(DIV_ROUND_UP(32, 32) * 4,
634 		sizeof(u32));
635 	BUG_ON(!gic->saved_ppi_enable);
636 
637 	gic->saved_ppi_conf = __alloc_percpu(DIV_ROUND_UP(32, 16) * 4,
638 		sizeof(u32));
639 	BUG_ON(!gic->saved_ppi_conf);
640 
641 	if (gic == &gic_data[0])
642 		cpu_pm_register_notifier(&gic_notifier_block);
643 }
644 #else
645 static void __init gic_pm_init(struct gic_chip_data *gic)
646 {
647 }
648 #endif
649 
650 #ifdef CONFIG_SMP
651 void gic_raise_softirq(const struct cpumask *mask, unsigned int irq)
652 {
653 	int cpu;
654 	unsigned long flags, map = 0;
655 
656 	raw_spin_lock_irqsave(&irq_controller_lock, flags);
657 
658 	/* Convert our logical CPU mask into a physical one. */
659 	for_each_cpu(cpu, mask)
660 		map |= gic_cpu_map[cpu];
661 
662 	/*
663 	 * Ensure that stores to Normal memory are visible to the
664 	 * other CPUs before issuing the IPI.
665 	 */
666 	dsb();
667 
668 	/* this always happens on GIC0 */
669 	writel_relaxed(map << 16 | irq, gic_data_dist_base(&gic_data[0]) + GIC_DIST_SOFTINT);
670 
671 	raw_spin_unlock_irqrestore(&irq_controller_lock, flags);
672 }
673 #endif
674 
675 #ifdef CONFIG_BL_SWITCHER
676 /*
677  * gic_send_sgi - send a SGI directly to given CPU interface number
678  *
679  * cpu_id: the ID for the destination CPU interface
680  * irq: the IPI number to send a SGI for
681  */
682 void gic_send_sgi(unsigned int cpu_id, unsigned int irq)
683 {
684 	BUG_ON(cpu_id >= NR_GIC_CPU_IF);
685 	cpu_id = 1 << cpu_id;
686 	/* this always happens on GIC0 */
687 	writel_relaxed((cpu_id << 16) | irq, gic_data_dist_base(&gic_data[0]) + GIC_DIST_SOFTINT);
688 }
689 
690 /*
691  * gic_get_cpu_id - get the CPU interface ID for the specified CPU
692  *
693  * @cpu: the logical CPU number to get the GIC ID for.
694  *
695  * Return the CPU interface ID for the given logical CPU number,
696  * or -1 if the CPU number is too large or the interface ID is
697  * unknown (more than one bit set).
698  */
699 int gic_get_cpu_id(unsigned int cpu)
700 {
701 	unsigned int cpu_bit;
702 
703 	if (cpu >= NR_GIC_CPU_IF)
704 		return -1;
705 	cpu_bit = gic_cpu_map[cpu];
706 	if (cpu_bit & (cpu_bit - 1))
707 		return -1;
708 	return __ffs(cpu_bit);
709 }
710 
711 /*
712  * gic_migrate_target - migrate IRQs to another CPU interface
713  *
714  * @new_cpu_id: the CPU target ID to migrate IRQs to
715  *
716  * Migrate all peripheral interrupts with a target matching the current CPU
717  * to the interface corresponding to @new_cpu_id.  The CPU interface mapping
718  * is also updated.  Targets to other CPU interfaces are unchanged.
719  * This must be called with IRQs locally disabled.
720  */
721 void gic_migrate_target(unsigned int new_cpu_id)
722 {
723 	unsigned int cur_cpu_id, gic_irqs, gic_nr = 0;
724 	void __iomem *dist_base;
725 	int i, ror_val, cpu = smp_processor_id();
726 	u32 val, cur_target_mask, active_mask;
727 
728 	if (gic_nr >= MAX_GIC_NR)
729 		BUG();
730 
731 	dist_base = gic_data_dist_base(&gic_data[gic_nr]);
732 	if (!dist_base)
733 		return;
734 	gic_irqs = gic_data[gic_nr].gic_irqs;
735 
736 	cur_cpu_id = __ffs(gic_cpu_map[cpu]);
737 	cur_target_mask = 0x01010101 << cur_cpu_id;
738 	ror_val = (cur_cpu_id - new_cpu_id) & 31;
739 
740 	raw_spin_lock(&irq_controller_lock);
741 
742 	/* Update the target interface for this logical CPU */
743 	gic_cpu_map[cpu] = 1 << new_cpu_id;
744 
745 	/*
746 	 * Find all the peripheral interrupts targetting the current
747 	 * CPU interface and migrate them to the new CPU interface.
748 	 * We skip DIST_TARGET 0 to 7 as they are read-only.
749 	 */
750 	for (i = 8; i < DIV_ROUND_UP(gic_irqs, 4); i++) {
751 		val = readl_relaxed(dist_base + GIC_DIST_TARGET + i * 4);
752 		active_mask = val & cur_target_mask;
753 		if (active_mask) {
754 			val &= ~active_mask;
755 			val |= ror32(active_mask, ror_val);
756 			writel_relaxed(val, dist_base + GIC_DIST_TARGET + i*4);
757 		}
758 	}
759 
760 	raw_spin_unlock(&irq_controller_lock);
761 
762 	/*
763 	 * Now let's migrate and clear any potential SGIs that might be
764 	 * pending for us (cur_cpu_id).  Since GIC_DIST_SGI_PENDING_SET
765 	 * is a banked register, we can only forward the SGI using
766 	 * GIC_DIST_SOFTINT.  The original SGI source is lost but Linux
767 	 * doesn't use that information anyway.
768 	 *
769 	 * For the same reason we do not adjust SGI source information
770 	 * for previously sent SGIs by us to other CPUs either.
771 	 */
772 	for (i = 0; i < 16; i += 4) {
773 		int j;
774 		val = readl_relaxed(dist_base + GIC_DIST_SGI_PENDING_SET + i);
775 		if (!val)
776 			continue;
777 		writel_relaxed(val, dist_base + GIC_DIST_SGI_PENDING_CLEAR + i);
778 		for (j = i; j < i + 4; j++) {
779 			if (val & 0xff)
780 				writel_relaxed((1 << (new_cpu_id + 16)) | j,
781 						dist_base + GIC_DIST_SOFTINT);
782 			val >>= 8;
783 		}
784 	}
785 }
786 
787 /*
788  * gic_get_sgir_physaddr - get the physical address for the SGI register
789  *
790  * REturn the physical address of the SGI register to be used
791  * by some early assembly code when the kernel is not yet available.
792  */
793 static unsigned long gic_dist_physaddr;
794 
795 unsigned long gic_get_sgir_physaddr(void)
796 {
797 	if (!gic_dist_physaddr)
798 		return 0;
799 	return gic_dist_physaddr + GIC_DIST_SOFTINT;
800 }
801 
802 void __init gic_init_physaddr(struct device_node *node)
803 {
804 	struct resource res;
805 	if (of_address_to_resource(node, 0, &res) == 0) {
806 		gic_dist_physaddr = res.start;
807 		pr_info("GIC physical location is %#lx\n", gic_dist_physaddr);
808 	}
809 }
810 
811 #else
812 #define gic_init_physaddr(node)  do { } while (0)
813 #endif
814 
815 static int gic_irq_domain_map(struct irq_domain *d, unsigned int irq,
816 				irq_hw_number_t hw)
817 {
818 	if (hw < 32) {
819 		irq_set_percpu_devid(irq);
820 		irq_set_chip_and_handler(irq, &gic_chip,
821 					 handle_percpu_devid_irq);
822 		set_irq_flags(irq, IRQF_VALID | IRQF_NOAUTOEN);
823 	} else {
824 		irq_set_chip_and_handler(irq, &gic_chip,
825 					 handle_fasteoi_irq);
826 		set_irq_flags(irq, IRQF_VALID | IRQF_PROBE);
827 	}
828 	irq_set_chip_data(irq, d->host_data);
829 	return 0;
830 }
831 
832 static int gic_irq_domain_xlate(struct irq_domain *d,
833 				struct device_node *controller,
834 				const u32 *intspec, unsigned int intsize,
835 				unsigned long *out_hwirq, unsigned int *out_type)
836 {
837 	if (d->of_node != controller)
838 		return -EINVAL;
839 	if (intsize < 3)
840 		return -EINVAL;
841 
842 	/* Get the interrupt number and add 16 to skip over SGIs */
843 	*out_hwirq = intspec[1] + 16;
844 
845 	/* For SPIs, we need to add 16 more to get the GIC irq ID number */
846 	if (!intspec[0])
847 		*out_hwirq += 16;
848 
849 	*out_type = intspec[2] & IRQ_TYPE_SENSE_MASK;
850 	return 0;
851 }
852 
853 #ifdef CONFIG_SMP
854 static int gic_secondary_init(struct notifier_block *nfb, unsigned long action,
855 			      void *hcpu)
856 {
857 	if (action == CPU_STARTING || action == CPU_STARTING_FROZEN)
858 		gic_cpu_init(&gic_data[0]);
859 	return NOTIFY_OK;
860 }
861 
862 /*
863  * Notifier for enabling the GIC CPU interface. Set an arbitrarily high
864  * priority because the GIC needs to be up before the ARM generic timers.
865  */
866 static struct notifier_block gic_cpu_notifier = {
867 	.notifier_call = gic_secondary_init,
868 	.priority = 100,
869 };
870 #endif
871 
872 const struct irq_domain_ops gic_irq_domain_ops = {
873 	.map = gic_irq_domain_map,
874 	.xlate = gic_irq_domain_xlate,
875 };
876 
877 void __init gic_init_bases(unsigned int gic_nr, int irq_start,
878 			   void __iomem *dist_base, void __iomem *cpu_base,
879 			   u32 percpu_offset, struct device_node *node)
880 {
881 	irq_hw_number_t hwirq_base;
882 	struct gic_chip_data *gic;
883 	int gic_irqs, irq_base, i;
884 
885 	BUG_ON(gic_nr >= MAX_GIC_NR);
886 
887 	gic = &gic_data[gic_nr];
888 #ifdef CONFIG_GIC_NON_BANKED
889 	if (percpu_offset) { /* Frankein-GIC without banked registers... */
890 		unsigned int cpu;
891 
892 		gic->dist_base.percpu_base = alloc_percpu(void __iomem *);
893 		gic->cpu_base.percpu_base = alloc_percpu(void __iomem *);
894 		if (WARN_ON(!gic->dist_base.percpu_base ||
895 			    !gic->cpu_base.percpu_base)) {
896 			free_percpu(gic->dist_base.percpu_base);
897 			free_percpu(gic->cpu_base.percpu_base);
898 			return;
899 		}
900 
901 		for_each_possible_cpu(cpu) {
902 			unsigned long offset = percpu_offset * cpu_logical_map(cpu);
903 			*per_cpu_ptr(gic->dist_base.percpu_base, cpu) = dist_base + offset;
904 			*per_cpu_ptr(gic->cpu_base.percpu_base, cpu) = cpu_base + offset;
905 		}
906 
907 		gic_set_base_accessor(gic, gic_get_percpu_base);
908 	} else
909 #endif
910 	{			/* Normal, sane GIC... */
911 		WARN(percpu_offset,
912 		     "GIC_NON_BANKED not enabled, ignoring %08x offset!",
913 		     percpu_offset);
914 		gic->dist_base.common_base = dist_base;
915 		gic->cpu_base.common_base = cpu_base;
916 		gic_set_base_accessor(gic, gic_get_common_base);
917 	}
918 
919 	/*
920 	 * Initialize the CPU interface map to all CPUs.
921 	 * It will be refined as each CPU probes its ID.
922 	 */
923 	for (i = 0; i < NR_GIC_CPU_IF; i++)
924 		gic_cpu_map[i] = 0xff;
925 
926 	/*
927 	 * For primary GICs, skip over SGIs.
928 	 * For secondary GICs, skip over PPIs, too.
929 	 */
930 	if (gic_nr == 0 && (irq_start & 31) > 0) {
931 		hwirq_base = 16;
932 		if (irq_start != -1)
933 			irq_start = (irq_start & ~31) + 16;
934 	} else {
935 		hwirq_base = 32;
936 	}
937 
938 	/*
939 	 * Find out how many interrupts are supported.
940 	 * The GIC only supports up to 1020 interrupt sources.
941 	 */
942 	gic_irqs = readl_relaxed(gic_data_dist_base(gic) + GIC_DIST_CTR) & 0x1f;
943 	gic_irqs = (gic_irqs + 1) * 32;
944 	if (gic_irqs > 1020)
945 		gic_irqs = 1020;
946 	gic->gic_irqs = gic_irqs;
947 
948 	gic_irqs -= hwirq_base; /* calculate # of irqs to allocate */
949 	irq_base = irq_alloc_descs(irq_start, 16, gic_irqs, numa_node_id());
950 	if (IS_ERR_VALUE(irq_base)) {
951 		WARN(1, "Cannot allocate irq_descs @ IRQ%d, assuming pre-allocated\n",
952 		     irq_start);
953 		irq_base = irq_start;
954 	}
955 	gic->domain = irq_domain_add_legacy(node, gic_irqs, irq_base,
956 				    hwirq_base, &gic_irq_domain_ops, gic);
957 	if (WARN_ON(!gic->domain))
958 		return;
959 
960 	if (gic_nr == 0) {
961 #ifdef CONFIG_SMP
962 		set_smp_cross_call(gic_raise_softirq);
963 		register_cpu_notifier(&gic_cpu_notifier);
964 #endif
965 		set_handle_irq(gic_handle_irq);
966 	}
967 
968 	gic_chip.flags |= gic_arch_extn.flags;
969 	gic_dist_init(gic);
970 	gic_cpu_init(gic);
971 	gic_pm_init(gic);
972 }
973 
974 #ifdef CONFIG_OF
975 static int gic_cnt __initdata;
976 
977 int __init gic_of_init(struct device_node *node, struct device_node *parent)
978 {
979 	void __iomem *cpu_base;
980 	void __iomem *dist_base;
981 	u32 percpu_offset;
982 	int irq;
983 
984 	if (WARN_ON(!node))
985 		return -ENODEV;
986 
987 	dist_base = of_iomap(node, 0);
988 	WARN(!dist_base, "unable to map gic dist registers\n");
989 
990 	cpu_base = of_iomap(node, 1);
991 	WARN(!cpu_base, "unable to map gic cpu registers\n");
992 
993 	if (of_property_read_u32(node, "cpu-offset", &percpu_offset))
994 		percpu_offset = 0;
995 
996 	gic_init_bases(gic_cnt, -1, dist_base, cpu_base, percpu_offset, node);
997 	if (!gic_cnt)
998 		gic_init_physaddr(node);
999 
1000 	if (parent) {
1001 		irq = irq_of_parse_and_map(node, 0);
1002 		gic_cascade_irq(gic_cnt, irq);
1003 	}
1004 	gic_cnt++;
1005 	return 0;
1006 }
1007 IRQCHIP_DECLARE(cortex_a15_gic, "arm,cortex-a15-gic", gic_of_init);
1008 IRQCHIP_DECLARE(cortex_a9_gic, "arm,cortex-a9-gic", gic_of_init);
1009 IRQCHIP_DECLARE(msm_8660_qgic, "qcom,msm-8660-qgic", gic_of_init);
1010 IRQCHIP_DECLARE(msm_qgic2, "qcom,msm-qgic2", gic_of_init);
1011 
1012 #endif
1013