xref: /openbmc/linux/drivers/irqchip/irq-gic.c (revision 94cdda6b)
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/acpi.h>
37 #include <linux/irqdomain.h>
38 #include <linux/interrupt.h>
39 #include <linux/percpu.h>
40 #include <linux/slab.h>
41 #include <linux/irqchip/chained_irq.h>
42 #include <linux/irqchip/arm-gic.h>
43 #include <linux/irqchip/arm-gic-acpi.h>
44 
45 #include <asm/cputype.h>
46 #include <asm/irq.h>
47 #include <asm/exception.h>
48 #include <asm/smp_plat.h>
49 
50 #include "irq-gic-common.h"
51 #include "irqchip.h"
52 
53 union gic_base {
54 	void __iomem *common_base;
55 	void __percpu * __iomem *percpu_base;
56 };
57 
58 struct gic_chip_data {
59 	union gic_base dist_base;
60 	union gic_base cpu_base;
61 #ifdef CONFIG_CPU_PM
62 	u32 saved_spi_enable[DIV_ROUND_UP(1020, 32)];
63 	u32 saved_spi_conf[DIV_ROUND_UP(1020, 16)];
64 	u32 saved_spi_target[DIV_ROUND_UP(1020, 4)];
65 	u32 __percpu *saved_ppi_enable;
66 	u32 __percpu *saved_ppi_conf;
67 #endif
68 	struct irq_domain *domain;
69 	unsigned int gic_irqs;
70 #ifdef CONFIG_GIC_NON_BANKED
71 	void __iomem *(*get_base)(union gic_base *);
72 #endif
73 };
74 
75 static DEFINE_RAW_SPINLOCK(irq_controller_lock);
76 
77 /*
78  * The GIC mapping of CPU interfaces does not necessarily match
79  * the logical CPU numbering.  Let's use a mapping as returned
80  * by the GIC itself.
81  */
82 #define NR_GIC_CPU_IF 8
83 static u8 gic_cpu_map[NR_GIC_CPU_IF] __read_mostly;
84 
85 /*
86  * Supported arch specific GIC irq extension.
87  * Default make them NULL.
88  */
89 struct irq_chip gic_arch_extn = {
90 	.irq_eoi	= NULL,
91 	.irq_mask	= NULL,
92 	.irq_unmask	= NULL,
93 	.irq_retrigger	= NULL,
94 	.irq_set_type	= NULL,
95 	.irq_set_wake	= NULL,
96 };
97 
98 #ifndef MAX_GIC_NR
99 #define MAX_GIC_NR	1
100 #endif
101 
102 static struct gic_chip_data gic_data[MAX_GIC_NR] __read_mostly;
103 
104 #ifdef CONFIG_GIC_NON_BANKED
105 static void __iomem *gic_get_percpu_base(union gic_base *base)
106 {
107 	return raw_cpu_read(*base->percpu_base);
108 }
109 
110 static void __iomem *gic_get_common_base(union gic_base *base)
111 {
112 	return base->common_base;
113 }
114 
115 static inline void __iomem *gic_data_dist_base(struct gic_chip_data *data)
116 {
117 	return data->get_base(&data->dist_base);
118 }
119 
120 static inline void __iomem *gic_data_cpu_base(struct gic_chip_data *data)
121 {
122 	return data->get_base(&data->cpu_base);
123 }
124 
125 static inline void gic_set_base_accessor(struct gic_chip_data *data,
126 					 void __iomem *(*f)(union gic_base *))
127 {
128 	data->get_base = f;
129 }
130 #else
131 #define gic_data_dist_base(d)	((d)->dist_base.common_base)
132 #define gic_data_cpu_base(d)	((d)->cpu_base.common_base)
133 #define gic_set_base_accessor(d, f)
134 #endif
135 
136 static inline void __iomem *gic_dist_base(struct irq_data *d)
137 {
138 	struct gic_chip_data *gic_data = irq_data_get_irq_chip_data(d);
139 	return gic_data_dist_base(gic_data);
140 }
141 
142 static inline void __iomem *gic_cpu_base(struct irq_data *d)
143 {
144 	struct gic_chip_data *gic_data = irq_data_get_irq_chip_data(d);
145 	return gic_data_cpu_base(gic_data);
146 }
147 
148 static inline unsigned int gic_irq(struct irq_data *d)
149 {
150 	return d->hwirq;
151 }
152 
153 /*
154  * Routines to acknowledge, disable and enable interrupts
155  */
156 static void gic_poke_irq(struct irq_data *d, u32 offset)
157 {
158 	u32 mask = 1 << (gic_irq(d) % 32);
159 	writel_relaxed(mask, gic_dist_base(d) + offset + (gic_irq(d) / 32) * 4);
160 }
161 
162 static int gic_peek_irq(struct irq_data *d, u32 offset)
163 {
164 	u32 mask = 1 << (gic_irq(d) % 32);
165 	return !!(readl_relaxed(gic_dist_base(d) + offset + (gic_irq(d) / 32) * 4) & mask);
166 }
167 
168 static void gic_mask_irq(struct irq_data *d)
169 {
170 	unsigned long flags;
171 
172 	raw_spin_lock_irqsave(&irq_controller_lock, flags);
173 	gic_poke_irq(d, GIC_DIST_ENABLE_CLEAR);
174 	if (gic_arch_extn.irq_mask)
175 		gic_arch_extn.irq_mask(d);
176 	raw_spin_unlock_irqrestore(&irq_controller_lock, flags);
177 }
178 
179 static void gic_unmask_irq(struct irq_data *d)
180 {
181 	unsigned long flags;
182 
183 	raw_spin_lock_irqsave(&irq_controller_lock, flags);
184 	if (gic_arch_extn.irq_unmask)
185 		gic_arch_extn.irq_unmask(d);
186 	gic_poke_irq(d, GIC_DIST_ENABLE_SET);
187 	raw_spin_unlock_irqrestore(&irq_controller_lock, flags);
188 }
189 
190 static void gic_eoi_irq(struct irq_data *d)
191 {
192 	if (gic_arch_extn.irq_eoi) {
193 		raw_spin_lock(&irq_controller_lock);
194 		gic_arch_extn.irq_eoi(d);
195 		raw_spin_unlock(&irq_controller_lock);
196 	}
197 
198 	writel_relaxed(gic_irq(d), gic_cpu_base(d) + GIC_CPU_EOI);
199 }
200 
201 static int gic_irq_set_irqchip_state(struct irq_data *d,
202 				     enum irqchip_irq_state which, bool val)
203 {
204 	u32 reg;
205 
206 	switch (which) {
207 	case IRQCHIP_STATE_PENDING:
208 		reg = val ? GIC_DIST_PENDING_SET : GIC_DIST_PENDING_CLEAR;
209 		break;
210 
211 	case IRQCHIP_STATE_ACTIVE:
212 		reg = val ? GIC_DIST_ACTIVE_SET : GIC_DIST_ACTIVE_CLEAR;
213 		break;
214 
215 	case IRQCHIP_STATE_MASKED:
216 		reg = val ? GIC_DIST_ENABLE_CLEAR : GIC_DIST_ENABLE_SET;
217 		break;
218 
219 	default:
220 		return -EINVAL;
221 	}
222 
223 	gic_poke_irq(d, reg);
224 	return 0;
225 }
226 
227 static int gic_irq_get_irqchip_state(struct irq_data *d,
228 				      enum irqchip_irq_state which, bool *val)
229 {
230 	switch (which) {
231 	case IRQCHIP_STATE_PENDING:
232 		*val = gic_peek_irq(d, GIC_DIST_PENDING_SET);
233 		break;
234 
235 	case IRQCHIP_STATE_ACTIVE:
236 		*val = gic_peek_irq(d, GIC_DIST_ACTIVE_SET);
237 		break;
238 
239 	case IRQCHIP_STATE_MASKED:
240 		*val = !gic_peek_irq(d, GIC_DIST_ENABLE_SET);
241 		break;
242 
243 	default:
244 		return -EINVAL;
245 	}
246 
247 	return 0;
248 }
249 
250 static int gic_set_type(struct irq_data *d, unsigned int type)
251 {
252 	void __iomem *base = gic_dist_base(d);
253 	unsigned int gicirq = gic_irq(d);
254 	unsigned long flags;
255 	int ret;
256 
257 	/* Interrupt configuration for SGIs can't be changed */
258 	if (gicirq < 16)
259 		return -EINVAL;
260 
261 	/* SPIs have restrictions on the supported types */
262 	if (gicirq >= 32 && type != IRQ_TYPE_LEVEL_HIGH &&
263 			    type != IRQ_TYPE_EDGE_RISING)
264 		return -EINVAL;
265 
266 	raw_spin_lock_irqsave(&irq_controller_lock, flags);
267 
268 	if (gic_arch_extn.irq_set_type)
269 		gic_arch_extn.irq_set_type(d, type);
270 
271 	ret = gic_configure_irq(gicirq, type, base, NULL);
272 
273 	raw_spin_unlock_irqrestore(&irq_controller_lock, flags);
274 
275 	return ret;
276 }
277 
278 static int gic_retrigger(struct irq_data *d)
279 {
280 	if (gic_arch_extn.irq_retrigger)
281 		return gic_arch_extn.irq_retrigger(d);
282 
283 	/* the genirq layer expects 0 if we can't retrigger in hardware */
284 	return 0;
285 }
286 
287 #ifdef CONFIG_SMP
288 static int gic_set_affinity(struct irq_data *d, const struct cpumask *mask_val,
289 			    bool force)
290 {
291 	void __iomem *reg = gic_dist_base(d) + GIC_DIST_TARGET + (gic_irq(d) & ~3);
292 	unsigned int cpu, shift = (gic_irq(d) % 4) * 8;
293 	u32 val, mask, bit;
294 	unsigned long flags;
295 
296 	if (!force)
297 		cpu = cpumask_any_and(mask_val, cpu_online_mask);
298 	else
299 		cpu = cpumask_first(mask_val);
300 
301 	if (cpu >= NR_GIC_CPU_IF || cpu >= nr_cpu_ids)
302 		return -EINVAL;
303 
304 	raw_spin_lock_irqsave(&irq_controller_lock, flags);
305 	mask = 0xff << shift;
306 	bit = gic_cpu_map[cpu] << shift;
307 	val = readl_relaxed(reg) & ~mask;
308 	writel_relaxed(val | bit, reg);
309 	raw_spin_unlock_irqrestore(&irq_controller_lock, flags);
310 
311 	return IRQ_SET_MASK_OK;
312 }
313 #endif
314 
315 #ifdef CONFIG_PM
316 static int gic_set_wake(struct irq_data *d, unsigned int on)
317 {
318 	int ret = -ENXIO;
319 
320 	if (gic_arch_extn.irq_set_wake)
321 		ret = gic_arch_extn.irq_set_wake(d, on);
322 
323 	return ret;
324 }
325 
326 #else
327 #define gic_set_wake	NULL
328 #endif
329 
330 static void __exception_irq_entry gic_handle_irq(struct pt_regs *regs)
331 {
332 	u32 irqstat, irqnr;
333 	struct gic_chip_data *gic = &gic_data[0];
334 	void __iomem *cpu_base = gic_data_cpu_base(gic);
335 
336 	do {
337 		irqstat = readl_relaxed(cpu_base + GIC_CPU_INTACK);
338 		irqnr = irqstat & GICC_IAR_INT_ID_MASK;
339 
340 		if (likely(irqnr > 15 && irqnr < 1021)) {
341 			handle_domain_irq(gic->domain, irqnr, regs);
342 			continue;
343 		}
344 		if (irqnr < 16) {
345 			writel_relaxed(irqstat, cpu_base + GIC_CPU_EOI);
346 #ifdef CONFIG_SMP
347 			handle_IPI(irqnr, regs);
348 #endif
349 			continue;
350 		}
351 		break;
352 	} while (1);
353 }
354 
355 static void gic_handle_cascade_irq(unsigned int irq, struct irq_desc *desc)
356 {
357 	struct gic_chip_data *chip_data = irq_get_handler_data(irq);
358 	struct irq_chip *chip = irq_get_chip(irq);
359 	unsigned int cascade_irq, gic_irq;
360 	unsigned long status;
361 
362 	chained_irq_enter(chip, desc);
363 
364 	raw_spin_lock(&irq_controller_lock);
365 	status = readl_relaxed(gic_data_cpu_base(chip_data) + GIC_CPU_INTACK);
366 	raw_spin_unlock(&irq_controller_lock);
367 
368 	gic_irq = (status & GICC_IAR_INT_ID_MASK);
369 	if (gic_irq == GICC_INT_SPURIOUS)
370 		goto out;
371 
372 	cascade_irq = irq_find_mapping(chip_data->domain, gic_irq);
373 	if (unlikely(gic_irq < 32 || gic_irq > 1020))
374 		handle_bad_irq(cascade_irq, desc);
375 	else
376 		generic_handle_irq(cascade_irq);
377 
378  out:
379 	chained_irq_exit(chip, desc);
380 }
381 
382 static struct irq_chip gic_chip = {
383 	.name			= "GIC",
384 	.irq_mask		= gic_mask_irq,
385 	.irq_unmask		= gic_unmask_irq,
386 	.irq_eoi		= gic_eoi_irq,
387 	.irq_set_type		= gic_set_type,
388 	.irq_retrigger		= gic_retrigger,
389 #ifdef CONFIG_SMP
390 	.irq_set_affinity	= gic_set_affinity,
391 #endif
392 	.irq_set_wake		= gic_set_wake,
393 	.irq_get_irqchip_state	= gic_irq_get_irqchip_state,
394 	.irq_set_irqchip_state	= gic_irq_set_irqchip_state,
395 };
396 
397 void __init gic_cascade_irq(unsigned int gic_nr, unsigned int irq)
398 {
399 	if (gic_nr >= MAX_GIC_NR)
400 		BUG();
401 	if (irq_set_handler_data(irq, &gic_data[gic_nr]) != 0)
402 		BUG();
403 	irq_set_chained_handler(irq, gic_handle_cascade_irq);
404 }
405 
406 static u8 gic_get_cpumask(struct gic_chip_data *gic)
407 {
408 	void __iomem *base = gic_data_dist_base(gic);
409 	u32 mask, i;
410 
411 	for (i = mask = 0; i < 32; i += 4) {
412 		mask = readl_relaxed(base + GIC_DIST_TARGET + i);
413 		mask |= mask >> 16;
414 		mask |= mask >> 8;
415 		if (mask)
416 			break;
417 	}
418 
419 	if (!mask && num_possible_cpus() > 1)
420 		pr_crit("GIC CPU mask not found - kernel will fail to boot.\n");
421 
422 	return mask;
423 }
424 
425 static void gic_cpu_if_up(void)
426 {
427 	void __iomem *cpu_base = gic_data_cpu_base(&gic_data[0]);
428 	u32 bypass = 0;
429 
430 	/*
431 	* Preserve bypass disable bits to be written back later
432 	*/
433 	bypass = readl(cpu_base + GIC_CPU_CTRL);
434 	bypass &= GICC_DIS_BYPASS_MASK;
435 
436 	writel_relaxed(bypass | GICC_ENABLE, cpu_base + GIC_CPU_CTRL);
437 }
438 
439 
440 static void __init gic_dist_init(struct gic_chip_data *gic)
441 {
442 	unsigned int i;
443 	u32 cpumask;
444 	unsigned int gic_irqs = gic->gic_irqs;
445 	void __iomem *base = gic_data_dist_base(gic);
446 
447 	writel_relaxed(GICD_DISABLE, base + GIC_DIST_CTRL);
448 
449 	/*
450 	 * Set all global interrupts to this CPU only.
451 	 */
452 	cpumask = gic_get_cpumask(gic);
453 	cpumask |= cpumask << 8;
454 	cpumask |= cpumask << 16;
455 	for (i = 32; i < gic_irqs; i += 4)
456 		writel_relaxed(cpumask, base + GIC_DIST_TARGET + i * 4 / 4);
457 
458 	gic_dist_config(base, gic_irqs, NULL);
459 
460 	writel_relaxed(GICD_ENABLE, base + GIC_DIST_CTRL);
461 }
462 
463 static void gic_cpu_init(struct gic_chip_data *gic)
464 {
465 	void __iomem *dist_base = gic_data_dist_base(gic);
466 	void __iomem *base = gic_data_cpu_base(gic);
467 	unsigned int cpu_mask, cpu = smp_processor_id();
468 	int i;
469 
470 	/*
471 	 * Get what the GIC says our CPU mask is.
472 	 */
473 	BUG_ON(cpu >= NR_GIC_CPU_IF);
474 	cpu_mask = gic_get_cpumask(gic);
475 	gic_cpu_map[cpu] = cpu_mask;
476 
477 	/*
478 	 * Clear our mask from the other map entries in case they're
479 	 * still undefined.
480 	 */
481 	for (i = 0; i < NR_GIC_CPU_IF; i++)
482 		if (i != cpu)
483 			gic_cpu_map[i] &= ~cpu_mask;
484 
485 	gic_cpu_config(dist_base, NULL);
486 
487 	writel_relaxed(GICC_INT_PRI_THRESHOLD, base + GIC_CPU_PRIMASK);
488 	gic_cpu_if_up();
489 }
490 
491 void gic_cpu_if_down(void)
492 {
493 	void __iomem *cpu_base = gic_data_cpu_base(&gic_data[0]);
494 	u32 val = 0;
495 
496 	val = readl(cpu_base + GIC_CPU_CTRL);
497 	val &= ~GICC_ENABLE;
498 	writel_relaxed(val, cpu_base + GIC_CPU_CTRL);
499 }
500 
501 #ifdef CONFIG_CPU_PM
502 /*
503  * Saves the GIC distributor registers during suspend or idle.  Must be called
504  * with interrupts disabled but before powering down the GIC.  After calling
505  * this function, no interrupts will be delivered by the GIC, and another
506  * platform-specific wakeup source must be enabled.
507  */
508 static void gic_dist_save(unsigned int gic_nr)
509 {
510 	unsigned int gic_irqs;
511 	void __iomem *dist_base;
512 	int i;
513 
514 	if (gic_nr >= MAX_GIC_NR)
515 		BUG();
516 
517 	gic_irqs = gic_data[gic_nr].gic_irqs;
518 	dist_base = gic_data_dist_base(&gic_data[gic_nr]);
519 
520 	if (!dist_base)
521 		return;
522 
523 	for (i = 0; i < DIV_ROUND_UP(gic_irqs, 16); i++)
524 		gic_data[gic_nr].saved_spi_conf[i] =
525 			readl_relaxed(dist_base + GIC_DIST_CONFIG + i * 4);
526 
527 	for (i = 0; i < DIV_ROUND_UP(gic_irqs, 4); i++)
528 		gic_data[gic_nr].saved_spi_target[i] =
529 			readl_relaxed(dist_base + GIC_DIST_TARGET + i * 4);
530 
531 	for (i = 0; i < DIV_ROUND_UP(gic_irqs, 32); i++)
532 		gic_data[gic_nr].saved_spi_enable[i] =
533 			readl_relaxed(dist_base + GIC_DIST_ENABLE_SET + i * 4);
534 }
535 
536 /*
537  * Restores the GIC distributor registers during resume or when coming out of
538  * idle.  Must be called before enabling interrupts.  If a level interrupt
539  * that occured while the GIC was suspended is still present, it will be
540  * handled normally, but any edge interrupts that occured will not be seen by
541  * the GIC and need to be handled by the platform-specific wakeup source.
542  */
543 static void gic_dist_restore(unsigned int gic_nr)
544 {
545 	unsigned int gic_irqs;
546 	unsigned int i;
547 	void __iomem *dist_base;
548 
549 	if (gic_nr >= MAX_GIC_NR)
550 		BUG();
551 
552 	gic_irqs = gic_data[gic_nr].gic_irqs;
553 	dist_base = gic_data_dist_base(&gic_data[gic_nr]);
554 
555 	if (!dist_base)
556 		return;
557 
558 	writel_relaxed(GICD_DISABLE, dist_base + GIC_DIST_CTRL);
559 
560 	for (i = 0; i < DIV_ROUND_UP(gic_irqs, 16); i++)
561 		writel_relaxed(gic_data[gic_nr].saved_spi_conf[i],
562 			dist_base + GIC_DIST_CONFIG + i * 4);
563 
564 	for (i = 0; i < DIV_ROUND_UP(gic_irqs, 4); i++)
565 		writel_relaxed(GICD_INT_DEF_PRI_X4,
566 			dist_base + GIC_DIST_PRI + i * 4);
567 
568 	for (i = 0; i < DIV_ROUND_UP(gic_irqs, 4); i++)
569 		writel_relaxed(gic_data[gic_nr].saved_spi_target[i],
570 			dist_base + GIC_DIST_TARGET + i * 4);
571 
572 	for (i = 0; i < DIV_ROUND_UP(gic_irqs, 32); i++)
573 		writel_relaxed(gic_data[gic_nr].saved_spi_enable[i],
574 			dist_base + GIC_DIST_ENABLE_SET + i * 4);
575 
576 	writel_relaxed(GICD_ENABLE, dist_base + GIC_DIST_CTRL);
577 }
578 
579 static void gic_cpu_save(unsigned int gic_nr)
580 {
581 	int i;
582 	u32 *ptr;
583 	void __iomem *dist_base;
584 	void __iomem *cpu_base;
585 
586 	if (gic_nr >= MAX_GIC_NR)
587 		BUG();
588 
589 	dist_base = gic_data_dist_base(&gic_data[gic_nr]);
590 	cpu_base = gic_data_cpu_base(&gic_data[gic_nr]);
591 
592 	if (!dist_base || !cpu_base)
593 		return;
594 
595 	ptr = raw_cpu_ptr(gic_data[gic_nr].saved_ppi_enable);
596 	for (i = 0; i < DIV_ROUND_UP(32, 32); i++)
597 		ptr[i] = readl_relaxed(dist_base + GIC_DIST_ENABLE_SET + i * 4);
598 
599 	ptr = raw_cpu_ptr(gic_data[gic_nr].saved_ppi_conf);
600 	for (i = 0; i < DIV_ROUND_UP(32, 16); i++)
601 		ptr[i] = readl_relaxed(dist_base + GIC_DIST_CONFIG + i * 4);
602 
603 }
604 
605 static void gic_cpu_restore(unsigned int gic_nr)
606 {
607 	int i;
608 	u32 *ptr;
609 	void __iomem *dist_base;
610 	void __iomem *cpu_base;
611 
612 	if (gic_nr >= MAX_GIC_NR)
613 		BUG();
614 
615 	dist_base = gic_data_dist_base(&gic_data[gic_nr]);
616 	cpu_base = gic_data_cpu_base(&gic_data[gic_nr]);
617 
618 	if (!dist_base || !cpu_base)
619 		return;
620 
621 	ptr = raw_cpu_ptr(gic_data[gic_nr].saved_ppi_enable);
622 	for (i = 0; i < DIV_ROUND_UP(32, 32); i++)
623 		writel_relaxed(ptr[i], dist_base + GIC_DIST_ENABLE_SET + i * 4);
624 
625 	ptr = raw_cpu_ptr(gic_data[gic_nr].saved_ppi_conf);
626 	for (i = 0; i < DIV_ROUND_UP(32, 16); i++)
627 		writel_relaxed(ptr[i], dist_base + GIC_DIST_CONFIG + i * 4);
628 
629 	for (i = 0; i < DIV_ROUND_UP(32, 4); i++)
630 		writel_relaxed(GICD_INT_DEF_PRI_X4,
631 					dist_base + GIC_DIST_PRI + i * 4);
632 
633 	writel_relaxed(GICC_INT_PRI_THRESHOLD, cpu_base + GIC_CPU_PRIMASK);
634 	gic_cpu_if_up();
635 }
636 
637 static int gic_notifier(struct notifier_block *self, unsigned long cmd,	void *v)
638 {
639 	int i;
640 
641 	for (i = 0; i < MAX_GIC_NR; i++) {
642 #ifdef CONFIG_GIC_NON_BANKED
643 		/* Skip over unused GICs */
644 		if (!gic_data[i].get_base)
645 			continue;
646 #endif
647 		switch (cmd) {
648 		case CPU_PM_ENTER:
649 			gic_cpu_save(i);
650 			break;
651 		case CPU_PM_ENTER_FAILED:
652 		case CPU_PM_EXIT:
653 			gic_cpu_restore(i);
654 			break;
655 		case CPU_CLUSTER_PM_ENTER:
656 			gic_dist_save(i);
657 			break;
658 		case CPU_CLUSTER_PM_ENTER_FAILED:
659 		case CPU_CLUSTER_PM_EXIT:
660 			gic_dist_restore(i);
661 			break;
662 		}
663 	}
664 
665 	return NOTIFY_OK;
666 }
667 
668 static struct notifier_block gic_notifier_block = {
669 	.notifier_call = gic_notifier,
670 };
671 
672 static void __init gic_pm_init(struct gic_chip_data *gic)
673 {
674 	gic->saved_ppi_enable = __alloc_percpu(DIV_ROUND_UP(32, 32) * 4,
675 		sizeof(u32));
676 	BUG_ON(!gic->saved_ppi_enable);
677 
678 	gic->saved_ppi_conf = __alloc_percpu(DIV_ROUND_UP(32, 16) * 4,
679 		sizeof(u32));
680 	BUG_ON(!gic->saved_ppi_conf);
681 
682 	if (gic == &gic_data[0])
683 		cpu_pm_register_notifier(&gic_notifier_block);
684 }
685 #else
686 static void __init gic_pm_init(struct gic_chip_data *gic)
687 {
688 }
689 #endif
690 
691 #ifdef CONFIG_SMP
692 static void gic_raise_softirq(const struct cpumask *mask, unsigned int irq)
693 {
694 	int cpu;
695 	unsigned long flags, map = 0;
696 
697 	raw_spin_lock_irqsave(&irq_controller_lock, flags);
698 
699 	/* Convert our logical CPU mask into a physical one. */
700 	for_each_cpu(cpu, mask)
701 		map |= gic_cpu_map[cpu];
702 
703 	/*
704 	 * Ensure that stores to Normal memory are visible to the
705 	 * other CPUs before they observe us issuing the IPI.
706 	 */
707 	dmb(ishst);
708 
709 	/* this always happens on GIC0 */
710 	writel_relaxed(map << 16 | irq, gic_data_dist_base(&gic_data[0]) + GIC_DIST_SOFTINT);
711 
712 	raw_spin_unlock_irqrestore(&irq_controller_lock, flags);
713 }
714 #endif
715 
716 #ifdef CONFIG_BL_SWITCHER
717 /*
718  * gic_send_sgi - send a SGI directly to given CPU interface number
719  *
720  * cpu_id: the ID for the destination CPU interface
721  * irq: the IPI number to send a SGI for
722  */
723 void gic_send_sgi(unsigned int cpu_id, unsigned int irq)
724 {
725 	BUG_ON(cpu_id >= NR_GIC_CPU_IF);
726 	cpu_id = 1 << cpu_id;
727 	/* this always happens on GIC0 */
728 	writel_relaxed((cpu_id << 16) | irq, gic_data_dist_base(&gic_data[0]) + GIC_DIST_SOFTINT);
729 }
730 
731 /*
732  * gic_get_cpu_id - get the CPU interface ID for the specified CPU
733  *
734  * @cpu: the logical CPU number to get the GIC ID for.
735  *
736  * Return the CPU interface ID for the given logical CPU number,
737  * or -1 if the CPU number is too large or the interface ID is
738  * unknown (more than one bit set).
739  */
740 int gic_get_cpu_id(unsigned int cpu)
741 {
742 	unsigned int cpu_bit;
743 
744 	if (cpu >= NR_GIC_CPU_IF)
745 		return -1;
746 	cpu_bit = gic_cpu_map[cpu];
747 	if (cpu_bit & (cpu_bit - 1))
748 		return -1;
749 	return __ffs(cpu_bit);
750 }
751 
752 /*
753  * gic_migrate_target - migrate IRQs to another CPU interface
754  *
755  * @new_cpu_id: the CPU target ID to migrate IRQs to
756  *
757  * Migrate all peripheral interrupts with a target matching the current CPU
758  * to the interface corresponding to @new_cpu_id.  The CPU interface mapping
759  * is also updated.  Targets to other CPU interfaces are unchanged.
760  * This must be called with IRQs locally disabled.
761  */
762 void gic_migrate_target(unsigned int new_cpu_id)
763 {
764 	unsigned int cur_cpu_id, gic_irqs, gic_nr = 0;
765 	void __iomem *dist_base;
766 	int i, ror_val, cpu = smp_processor_id();
767 	u32 val, cur_target_mask, active_mask;
768 
769 	if (gic_nr >= MAX_GIC_NR)
770 		BUG();
771 
772 	dist_base = gic_data_dist_base(&gic_data[gic_nr]);
773 	if (!dist_base)
774 		return;
775 	gic_irqs = gic_data[gic_nr].gic_irqs;
776 
777 	cur_cpu_id = __ffs(gic_cpu_map[cpu]);
778 	cur_target_mask = 0x01010101 << cur_cpu_id;
779 	ror_val = (cur_cpu_id - new_cpu_id) & 31;
780 
781 	raw_spin_lock(&irq_controller_lock);
782 
783 	/* Update the target interface for this logical CPU */
784 	gic_cpu_map[cpu] = 1 << new_cpu_id;
785 
786 	/*
787 	 * Find all the peripheral interrupts targetting the current
788 	 * CPU interface and migrate them to the new CPU interface.
789 	 * We skip DIST_TARGET 0 to 7 as they are read-only.
790 	 */
791 	for (i = 8; i < DIV_ROUND_UP(gic_irqs, 4); i++) {
792 		val = readl_relaxed(dist_base + GIC_DIST_TARGET + i * 4);
793 		active_mask = val & cur_target_mask;
794 		if (active_mask) {
795 			val &= ~active_mask;
796 			val |= ror32(active_mask, ror_val);
797 			writel_relaxed(val, dist_base + GIC_DIST_TARGET + i*4);
798 		}
799 	}
800 
801 	raw_spin_unlock(&irq_controller_lock);
802 
803 	/*
804 	 * Now let's migrate and clear any potential SGIs that might be
805 	 * pending for us (cur_cpu_id).  Since GIC_DIST_SGI_PENDING_SET
806 	 * is a banked register, we can only forward the SGI using
807 	 * GIC_DIST_SOFTINT.  The original SGI source is lost but Linux
808 	 * doesn't use that information anyway.
809 	 *
810 	 * For the same reason we do not adjust SGI source information
811 	 * for previously sent SGIs by us to other CPUs either.
812 	 */
813 	for (i = 0; i < 16; i += 4) {
814 		int j;
815 		val = readl_relaxed(dist_base + GIC_DIST_SGI_PENDING_SET + i);
816 		if (!val)
817 			continue;
818 		writel_relaxed(val, dist_base + GIC_DIST_SGI_PENDING_CLEAR + i);
819 		for (j = i; j < i + 4; j++) {
820 			if (val & 0xff)
821 				writel_relaxed((1 << (new_cpu_id + 16)) | j,
822 						dist_base + GIC_DIST_SOFTINT);
823 			val >>= 8;
824 		}
825 	}
826 }
827 
828 /*
829  * gic_get_sgir_physaddr - get the physical address for the SGI register
830  *
831  * REturn the physical address of the SGI register to be used
832  * by some early assembly code when the kernel is not yet available.
833  */
834 static unsigned long gic_dist_physaddr;
835 
836 unsigned long gic_get_sgir_physaddr(void)
837 {
838 	if (!gic_dist_physaddr)
839 		return 0;
840 	return gic_dist_physaddr + GIC_DIST_SOFTINT;
841 }
842 
843 void __init gic_init_physaddr(struct device_node *node)
844 {
845 	struct resource res;
846 	if (of_address_to_resource(node, 0, &res) == 0) {
847 		gic_dist_physaddr = res.start;
848 		pr_info("GIC physical location is %#lx\n", gic_dist_physaddr);
849 	}
850 }
851 
852 #else
853 #define gic_init_physaddr(node)  do { } while (0)
854 #endif
855 
856 static int gic_irq_domain_map(struct irq_domain *d, unsigned int irq,
857 				irq_hw_number_t hw)
858 {
859 	if (hw < 32) {
860 		irq_set_percpu_devid(irq);
861 		irq_domain_set_info(d, irq, hw, &gic_chip, d->host_data,
862 				    handle_percpu_devid_irq, NULL, NULL);
863 		set_irq_flags(irq, IRQF_VALID | IRQF_NOAUTOEN);
864 	} else {
865 		irq_domain_set_info(d, irq, hw, &gic_chip, d->host_data,
866 				    handle_fasteoi_irq, NULL, NULL);
867 		set_irq_flags(irq, IRQF_VALID | IRQF_PROBE);
868 	}
869 	return 0;
870 }
871 
872 static void gic_irq_domain_unmap(struct irq_domain *d, unsigned int irq)
873 {
874 }
875 
876 static int gic_irq_domain_xlate(struct irq_domain *d,
877 				struct device_node *controller,
878 				const u32 *intspec, unsigned int intsize,
879 				unsigned long *out_hwirq, unsigned int *out_type)
880 {
881 	unsigned long ret = 0;
882 
883 	if (d->of_node != controller)
884 		return -EINVAL;
885 	if (intsize < 3)
886 		return -EINVAL;
887 
888 	/* Get the interrupt number and add 16 to skip over SGIs */
889 	*out_hwirq = intspec[1] + 16;
890 
891 	/* For SPIs, we need to add 16 more to get the GIC irq ID number */
892 	if (!intspec[0])
893 		*out_hwirq += 16;
894 
895 	*out_type = intspec[2] & IRQ_TYPE_SENSE_MASK;
896 
897 	return ret;
898 }
899 
900 #ifdef CONFIG_SMP
901 static int gic_secondary_init(struct notifier_block *nfb, unsigned long action,
902 			      void *hcpu)
903 {
904 	if (action == CPU_STARTING || action == CPU_STARTING_FROZEN)
905 		gic_cpu_init(&gic_data[0]);
906 	return NOTIFY_OK;
907 }
908 
909 /*
910  * Notifier for enabling the GIC CPU interface. Set an arbitrarily high
911  * priority because the GIC needs to be up before the ARM generic timers.
912  */
913 static struct notifier_block gic_cpu_notifier = {
914 	.notifier_call = gic_secondary_init,
915 	.priority = 100,
916 };
917 #endif
918 
919 static int gic_irq_domain_alloc(struct irq_domain *domain, unsigned int virq,
920 				unsigned int nr_irqs, void *arg)
921 {
922 	int i, ret;
923 	irq_hw_number_t hwirq;
924 	unsigned int type = IRQ_TYPE_NONE;
925 	struct of_phandle_args *irq_data = arg;
926 
927 	ret = gic_irq_domain_xlate(domain, irq_data->np, irq_data->args,
928 				   irq_data->args_count, &hwirq, &type);
929 	if (ret)
930 		return ret;
931 
932 	for (i = 0; i < nr_irqs; i++)
933 		gic_irq_domain_map(domain, virq + i, hwirq + i);
934 
935 	return 0;
936 }
937 
938 static const struct irq_domain_ops gic_irq_domain_hierarchy_ops = {
939 	.xlate = gic_irq_domain_xlate,
940 	.alloc = gic_irq_domain_alloc,
941 	.free = irq_domain_free_irqs_top,
942 };
943 
944 static const struct irq_domain_ops gic_irq_domain_ops = {
945 	.map = gic_irq_domain_map,
946 	.unmap = gic_irq_domain_unmap,
947 	.xlate = gic_irq_domain_xlate,
948 };
949 
950 void gic_set_irqchip_flags(unsigned long flags)
951 {
952 	gic_chip.flags |= flags;
953 }
954 
955 void __init gic_init_bases(unsigned int gic_nr, int irq_start,
956 			   void __iomem *dist_base, void __iomem *cpu_base,
957 			   u32 percpu_offset, struct device_node *node)
958 {
959 	irq_hw_number_t hwirq_base;
960 	struct gic_chip_data *gic;
961 	int gic_irqs, irq_base, i;
962 
963 	BUG_ON(gic_nr >= MAX_GIC_NR);
964 
965 	gic = &gic_data[gic_nr];
966 #ifdef CONFIG_GIC_NON_BANKED
967 	if (percpu_offset) { /* Frankein-GIC without banked registers... */
968 		unsigned int cpu;
969 
970 		gic->dist_base.percpu_base = alloc_percpu(void __iomem *);
971 		gic->cpu_base.percpu_base = alloc_percpu(void __iomem *);
972 		if (WARN_ON(!gic->dist_base.percpu_base ||
973 			    !gic->cpu_base.percpu_base)) {
974 			free_percpu(gic->dist_base.percpu_base);
975 			free_percpu(gic->cpu_base.percpu_base);
976 			return;
977 		}
978 
979 		for_each_possible_cpu(cpu) {
980 			u32 mpidr = cpu_logical_map(cpu);
981 			u32 core_id = MPIDR_AFFINITY_LEVEL(mpidr, 0);
982 			unsigned long offset = percpu_offset * core_id;
983 			*per_cpu_ptr(gic->dist_base.percpu_base, cpu) = dist_base + offset;
984 			*per_cpu_ptr(gic->cpu_base.percpu_base, cpu) = cpu_base + offset;
985 		}
986 
987 		gic_set_base_accessor(gic, gic_get_percpu_base);
988 	} else
989 #endif
990 	{			/* Normal, sane GIC... */
991 		WARN(percpu_offset,
992 		     "GIC_NON_BANKED not enabled, ignoring %08x offset!",
993 		     percpu_offset);
994 		gic->dist_base.common_base = dist_base;
995 		gic->cpu_base.common_base = cpu_base;
996 		gic_set_base_accessor(gic, gic_get_common_base);
997 	}
998 
999 	/*
1000 	 * Initialize the CPU interface map to all CPUs.
1001 	 * It will be refined as each CPU probes its ID.
1002 	 */
1003 	for (i = 0; i < NR_GIC_CPU_IF; i++)
1004 		gic_cpu_map[i] = 0xff;
1005 
1006 	/*
1007 	 * Find out how many interrupts are supported.
1008 	 * The GIC only supports up to 1020 interrupt sources.
1009 	 */
1010 	gic_irqs = readl_relaxed(gic_data_dist_base(gic) + GIC_DIST_CTR) & 0x1f;
1011 	gic_irqs = (gic_irqs + 1) * 32;
1012 	if (gic_irqs > 1020)
1013 		gic_irqs = 1020;
1014 	gic->gic_irqs = gic_irqs;
1015 
1016 	if (node) {		/* DT case */
1017 		gic->domain = irq_domain_add_linear(node, gic_irqs,
1018 						    &gic_irq_domain_hierarchy_ops,
1019 						    gic);
1020 	} else {		/* Non-DT case */
1021 		/*
1022 		 * For primary GICs, skip over SGIs.
1023 		 * For secondary GICs, skip over PPIs, too.
1024 		 */
1025 		if (gic_nr == 0 && (irq_start & 31) > 0) {
1026 			hwirq_base = 16;
1027 			if (irq_start != -1)
1028 				irq_start = (irq_start & ~31) + 16;
1029 		} else {
1030 			hwirq_base = 32;
1031 		}
1032 
1033 		gic_irqs -= hwirq_base; /* calculate # of irqs to allocate */
1034 
1035 		irq_base = irq_alloc_descs(irq_start, 16, gic_irqs,
1036 					   numa_node_id());
1037 		if (IS_ERR_VALUE(irq_base)) {
1038 			WARN(1, "Cannot allocate irq_descs @ IRQ%d, assuming pre-allocated\n",
1039 			     irq_start);
1040 			irq_base = irq_start;
1041 		}
1042 
1043 		gic->domain = irq_domain_add_legacy(node, gic_irqs, irq_base,
1044 					hwirq_base, &gic_irq_domain_ops, gic);
1045 	}
1046 
1047 	if (WARN_ON(!gic->domain))
1048 		return;
1049 
1050 	if (gic_nr == 0) {
1051 #ifdef CONFIG_SMP
1052 		set_smp_cross_call(gic_raise_softirq);
1053 		register_cpu_notifier(&gic_cpu_notifier);
1054 #endif
1055 		set_handle_irq(gic_handle_irq);
1056 	}
1057 
1058 	gic_chip.flags |= gic_arch_extn.flags;
1059 	gic_dist_init(gic);
1060 	gic_cpu_init(gic);
1061 	gic_pm_init(gic);
1062 }
1063 
1064 #ifdef CONFIG_OF
1065 static int gic_cnt __initdata;
1066 
1067 static int __init
1068 gic_of_init(struct device_node *node, struct device_node *parent)
1069 {
1070 	void __iomem *cpu_base;
1071 	void __iomem *dist_base;
1072 	u32 percpu_offset;
1073 	int irq;
1074 
1075 	if (WARN_ON(!node))
1076 		return -ENODEV;
1077 
1078 	dist_base = of_iomap(node, 0);
1079 	WARN(!dist_base, "unable to map gic dist registers\n");
1080 
1081 	cpu_base = of_iomap(node, 1);
1082 	WARN(!cpu_base, "unable to map gic cpu registers\n");
1083 
1084 	if (of_property_read_u32(node, "cpu-offset", &percpu_offset))
1085 		percpu_offset = 0;
1086 
1087 	gic_init_bases(gic_cnt, -1, dist_base, cpu_base, percpu_offset, node);
1088 	if (!gic_cnt)
1089 		gic_init_physaddr(node);
1090 
1091 	if (parent) {
1092 		irq = irq_of_parse_and_map(node, 0);
1093 		gic_cascade_irq(gic_cnt, irq);
1094 	}
1095 
1096 	if (IS_ENABLED(CONFIG_ARM_GIC_V2M))
1097 		gicv2m_of_init(node, gic_data[gic_cnt].domain);
1098 
1099 	gic_cnt++;
1100 	return 0;
1101 }
1102 IRQCHIP_DECLARE(gic_400, "arm,gic-400", gic_of_init);
1103 IRQCHIP_DECLARE(arm11mp_gic, "arm,arm11mp-gic", gic_of_init);
1104 IRQCHIP_DECLARE(arm1176jzf_dc_gic, "arm,arm1176jzf-devchip-gic", gic_of_init);
1105 IRQCHIP_DECLARE(cortex_a15_gic, "arm,cortex-a15-gic", gic_of_init);
1106 IRQCHIP_DECLARE(cortex_a9_gic, "arm,cortex-a9-gic", gic_of_init);
1107 IRQCHIP_DECLARE(cortex_a7_gic, "arm,cortex-a7-gic", gic_of_init);
1108 IRQCHIP_DECLARE(msm_8660_qgic, "qcom,msm-8660-qgic", gic_of_init);
1109 IRQCHIP_DECLARE(msm_qgic2, "qcom,msm-qgic2", gic_of_init);
1110 
1111 #endif
1112 
1113 #ifdef CONFIG_ACPI
1114 static phys_addr_t dist_phy_base, cpu_phy_base __initdata;
1115 
1116 static int __init
1117 gic_acpi_parse_madt_cpu(struct acpi_subtable_header *header,
1118 			const unsigned long end)
1119 {
1120 	struct acpi_madt_generic_interrupt *processor;
1121 	phys_addr_t gic_cpu_base;
1122 	static int cpu_base_assigned;
1123 
1124 	processor = (struct acpi_madt_generic_interrupt *)header;
1125 
1126 	if (BAD_MADT_ENTRY(processor, end))
1127 		return -EINVAL;
1128 
1129 	/*
1130 	 * There is no support for non-banked GICv1/2 register in ACPI spec.
1131 	 * All CPU interface addresses have to be the same.
1132 	 */
1133 	gic_cpu_base = processor->base_address;
1134 	if (cpu_base_assigned && gic_cpu_base != cpu_phy_base)
1135 		return -EINVAL;
1136 
1137 	cpu_phy_base = gic_cpu_base;
1138 	cpu_base_assigned = 1;
1139 	return 0;
1140 }
1141 
1142 static int __init
1143 gic_acpi_parse_madt_distributor(struct acpi_subtable_header *header,
1144 				const unsigned long end)
1145 {
1146 	struct acpi_madt_generic_distributor *dist;
1147 
1148 	dist = (struct acpi_madt_generic_distributor *)header;
1149 
1150 	if (BAD_MADT_ENTRY(dist, end))
1151 		return -EINVAL;
1152 
1153 	dist_phy_base = dist->base_address;
1154 	return 0;
1155 }
1156 
1157 int __init
1158 gic_v2_acpi_init(struct acpi_table_header *table)
1159 {
1160 	void __iomem *cpu_base, *dist_base;
1161 	int count;
1162 
1163 	/* Collect CPU base addresses */
1164 	count = acpi_parse_entries(ACPI_SIG_MADT,
1165 				   sizeof(struct acpi_table_madt),
1166 				   gic_acpi_parse_madt_cpu, table,
1167 				   ACPI_MADT_TYPE_GENERIC_INTERRUPT, 0);
1168 	if (count <= 0) {
1169 		pr_err("No valid GICC entries exist\n");
1170 		return -EINVAL;
1171 	}
1172 
1173 	/*
1174 	 * Find distributor base address. We expect one distributor entry since
1175 	 * ACPI 5.1 spec neither support multi-GIC instances nor GIC cascade.
1176 	 */
1177 	count = acpi_parse_entries(ACPI_SIG_MADT,
1178 				   sizeof(struct acpi_table_madt),
1179 				   gic_acpi_parse_madt_distributor, table,
1180 				   ACPI_MADT_TYPE_GENERIC_DISTRIBUTOR, 0);
1181 	if (count <= 0) {
1182 		pr_err("No valid GICD entries exist\n");
1183 		return -EINVAL;
1184 	} else if (count > 1) {
1185 		pr_err("More than one GICD entry detected\n");
1186 		return -EINVAL;
1187 	}
1188 
1189 	cpu_base = ioremap(cpu_phy_base, ACPI_GIC_CPU_IF_MEM_SIZE);
1190 	if (!cpu_base) {
1191 		pr_err("Unable to map GICC registers\n");
1192 		return -ENOMEM;
1193 	}
1194 
1195 	dist_base = ioremap(dist_phy_base, ACPI_GICV2_DIST_MEM_SIZE);
1196 	if (!dist_base) {
1197 		pr_err("Unable to map GICD registers\n");
1198 		iounmap(cpu_base);
1199 		return -ENOMEM;
1200 	}
1201 
1202 	/*
1203 	 * Initialize zero GIC instance (no multi-GIC support). Also, set GIC
1204 	 * as default IRQ domain to allow for GSI registration and GSI to IRQ
1205 	 * number translation (see acpi_register_gsi() and acpi_gsi_to_irq()).
1206 	 */
1207 	gic_init_bases(0, -1, dist_base, cpu_base, 0, NULL);
1208 	irq_set_default_host(gic_data[0].domain);
1209 
1210 	acpi_irq_model = ACPI_IRQ_MODEL_GIC;
1211 	return 0;
1212 }
1213 #endif
1214