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1 /*
2  * Copyright (C) 1992, 1998-2006 Linus Torvalds, Ingo Molnar
3  * Copyright (C) 2005-2006, Thomas Gleixner, Russell King
4  *
5  * This file contains the interrupt descriptor management code
6  *
7  * Detailed information is available in Documentation/DocBook/genericirq
8  *
9  */
10 #include <linux/irq.h>
11 #include <linux/slab.h>
12 #include <linux/export.h>
13 #include <linux/interrupt.h>
14 #include <linux/kernel_stat.h>
15 #include <linux/radix-tree.h>
16 #include <linux/bitmap.h>
17 #include <linux/irqdomain.h>
18 #include <linux/sysfs.h>
19 
20 #include "internals.h"
21 
22 /*
23  * lockdep: we want to handle all irq_desc locks as a single lock-class:
24  */
25 static struct lock_class_key irq_desc_lock_class;
26 
27 #if defined(CONFIG_SMP)
irq_affinity_setup(char * str)28 static int __init irq_affinity_setup(char *str)
29 {
30 	zalloc_cpumask_var(&irq_default_affinity, GFP_NOWAIT);
31 	cpulist_parse(str, irq_default_affinity);
32 	/*
33 	 * Set at least the boot cpu. We don't want to end up with
34 	 * bugreports caused by random comandline masks
35 	 */
36 	cpumask_set_cpu(smp_processor_id(), irq_default_affinity);
37 	return 1;
38 }
39 __setup("irqaffinity=", irq_affinity_setup);
40 
init_irq_default_affinity(void)41 static void __init init_irq_default_affinity(void)
42 {
43 #ifdef CONFIG_CPUMASK_OFFSTACK
44 	if (!irq_default_affinity)
45 		zalloc_cpumask_var(&irq_default_affinity, GFP_NOWAIT);
46 #endif
47 	if (cpumask_empty(irq_default_affinity))
48 		cpumask_setall(irq_default_affinity);
49 }
50 #else
init_irq_default_affinity(void)51 static void __init init_irq_default_affinity(void)
52 {
53 }
54 #endif
55 
56 #ifdef CONFIG_SMP
alloc_masks(struct irq_desc * desc,gfp_t gfp,int node)57 static int alloc_masks(struct irq_desc *desc, gfp_t gfp, int node)
58 {
59 	if (!zalloc_cpumask_var_node(&desc->irq_common_data.affinity,
60 				     gfp, node))
61 		return -ENOMEM;
62 
63 #ifdef CONFIG_GENERIC_PENDING_IRQ
64 	if (!zalloc_cpumask_var_node(&desc->pending_mask, gfp, node)) {
65 		free_cpumask_var(desc->irq_common_data.affinity);
66 		return -ENOMEM;
67 	}
68 #endif
69 	return 0;
70 }
71 
desc_smp_init(struct irq_desc * desc,int node,const struct cpumask * affinity)72 static void desc_smp_init(struct irq_desc *desc, int node,
73 			  const struct cpumask *affinity)
74 {
75 	if (!affinity)
76 		affinity = irq_default_affinity;
77 	cpumask_copy(desc->irq_common_data.affinity, affinity);
78 
79 #ifdef CONFIG_GENERIC_PENDING_IRQ
80 	cpumask_clear(desc->pending_mask);
81 #endif
82 #ifdef CONFIG_NUMA
83 	desc->irq_common_data.node = node;
84 #endif
85 }
86 
87 #else
88 static inline int
alloc_masks(struct irq_desc * desc,gfp_t gfp,int node)89 alloc_masks(struct irq_desc *desc, gfp_t gfp, int node) { return 0; }
90 static inline void
desc_smp_init(struct irq_desc * desc,int node,const struct cpumask * affinity)91 desc_smp_init(struct irq_desc *desc, int node, const struct cpumask *affinity) { }
92 #endif
93 
desc_set_defaults(unsigned int irq,struct irq_desc * desc,int node,const struct cpumask * affinity,struct module * owner)94 static void desc_set_defaults(unsigned int irq, struct irq_desc *desc, int node,
95 			      const struct cpumask *affinity, struct module *owner)
96 {
97 	int cpu;
98 
99 	desc->irq_common_data.handler_data = NULL;
100 	desc->irq_common_data.msi_desc = NULL;
101 
102 	desc->irq_data.common = &desc->irq_common_data;
103 	desc->irq_data.irq = irq;
104 	desc->irq_data.chip = &no_irq_chip;
105 	desc->irq_data.chip_data = NULL;
106 	irq_settings_clr_and_set(desc, ~0, _IRQ_DEFAULT_INIT_FLAGS);
107 	irqd_set(&desc->irq_data, IRQD_IRQ_DISABLED);
108 	desc->handle_irq = handle_bad_irq;
109 	desc->depth = 1;
110 	desc->irq_count = 0;
111 	desc->irqs_unhandled = 0;
112 	desc->name = NULL;
113 	desc->owner = owner;
114 	for_each_possible_cpu(cpu)
115 		*per_cpu_ptr(desc->kstat_irqs, cpu) = 0;
116 	desc_smp_init(desc, node, affinity);
117 }
118 
119 int nr_irqs = NR_IRQS;
120 EXPORT_SYMBOL_GPL(nr_irqs);
121 
122 static DEFINE_MUTEX(sparse_irq_lock);
123 static DECLARE_BITMAP(allocated_irqs, IRQ_BITMAP_BITS);
124 
125 #ifdef CONFIG_SPARSE_IRQ
126 
127 static void irq_kobj_release(struct kobject *kobj);
128 
129 #ifdef CONFIG_SYSFS
130 static struct kobject *irq_kobj_base;
131 
132 #define IRQ_ATTR_RO(_name) \
133 static struct kobj_attribute _name##_attr = __ATTR_RO(_name)
134 
per_cpu_count_show(struct kobject * kobj,struct kobj_attribute * attr,char * buf)135 static ssize_t per_cpu_count_show(struct kobject *kobj,
136 				  struct kobj_attribute *attr, char *buf)
137 {
138 	struct irq_desc *desc = container_of(kobj, struct irq_desc, kobj);
139 	int cpu, irq = desc->irq_data.irq;
140 	ssize_t ret = 0;
141 	char *p = "";
142 
143 	for_each_possible_cpu(cpu) {
144 		unsigned int c = kstat_irqs_cpu(irq, cpu);
145 
146 		ret += scnprintf(buf + ret, PAGE_SIZE - ret, "%s%u", p, c);
147 		p = ",";
148 	}
149 
150 	ret += scnprintf(buf + ret, PAGE_SIZE - ret, "\n");
151 	return ret;
152 }
153 IRQ_ATTR_RO(per_cpu_count);
154 
chip_name_show(struct kobject * kobj,struct kobj_attribute * attr,char * buf)155 static ssize_t chip_name_show(struct kobject *kobj,
156 			      struct kobj_attribute *attr, char *buf)
157 {
158 	struct irq_desc *desc = container_of(kobj, struct irq_desc, kobj);
159 	ssize_t ret = 0;
160 
161 	raw_spin_lock_irq(&desc->lock);
162 	if (desc->irq_data.chip && desc->irq_data.chip->name) {
163 		ret = scnprintf(buf, PAGE_SIZE, "%s\n",
164 				desc->irq_data.chip->name);
165 	}
166 	raw_spin_unlock_irq(&desc->lock);
167 
168 	return ret;
169 }
170 IRQ_ATTR_RO(chip_name);
171 
hwirq_show(struct kobject * kobj,struct kobj_attribute * attr,char * buf)172 static ssize_t hwirq_show(struct kobject *kobj,
173 			  struct kobj_attribute *attr, char *buf)
174 {
175 	struct irq_desc *desc = container_of(kobj, struct irq_desc, kobj);
176 	ssize_t ret = 0;
177 
178 	raw_spin_lock_irq(&desc->lock);
179 	if (desc->irq_data.domain)
180 		ret = sprintf(buf, "%d\n", (int)desc->irq_data.hwirq);
181 	raw_spin_unlock_irq(&desc->lock);
182 
183 	return ret;
184 }
185 IRQ_ATTR_RO(hwirq);
186 
type_show(struct kobject * kobj,struct kobj_attribute * attr,char * buf)187 static ssize_t type_show(struct kobject *kobj,
188 			 struct kobj_attribute *attr, char *buf)
189 {
190 	struct irq_desc *desc = container_of(kobj, struct irq_desc, kobj);
191 	ssize_t ret = 0;
192 
193 	raw_spin_lock_irq(&desc->lock);
194 	ret = sprintf(buf, "%s\n",
195 		      irqd_is_level_type(&desc->irq_data) ? "level" : "edge");
196 	raw_spin_unlock_irq(&desc->lock);
197 
198 	return ret;
199 
200 }
201 IRQ_ATTR_RO(type);
202 
name_show(struct kobject * kobj,struct kobj_attribute * attr,char * buf)203 static ssize_t name_show(struct kobject *kobj,
204 			 struct kobj_attribute *attr, char *buf)
205 {
206 	struct irq_desc *desc = container_of(kobj, struct irq_desc, kobj);
207 	ssize_t ret = 0;
208 
209 	raw_spin_lock_irq(&desc->lock);
210 	if (desc->name)
211 		ret = scnprintf(buf, PAGE_SIZE, "%s\n", desc->name);
212 	raw_spin_unlock_irq(&desc->lock);
213 
214 	return ret;
215 }
216 IRQ_ATTR_RO(name);
217 
actions_show(struct kobject * kobj,struct kobj_attribute * attr,char * buf)218 static ssize_t actions_show(struct kobject *kobj,
219 			    struct kobj_attribute *attr, char *buf)
220 {
221 	struct irq_desc *desc = container_of(kobj, struct irq_desc, kobj);
222 	struct irqaction *action;
223 	ssize_t ret = 0;
224 	char *p = "";
225 
226 	raw_spin_lock_irq(&desc->lock);
227 	for (action = desc->action; action != NULL; action = action->next) {
228 		ret += scnprintf(buf + ret, PAGE_SIZE - ret, "%s%s",
229 				 p, action->name);
230 		p = ",";
231 	}
232 	raw_spin_unlock_irq(&desc->lock);
233 
234 	if (ret)
235 		ret += scnprintf(buf + ret, PAGE_SIZE - ret, "\n");
236 
237 	return ret;
238 }
239 IRQ_ATTR_RO(actions);
240 
241 static struct attribute *irq_attrs[] = {
242 	&per_cpu_count_attr.attr,
243 	&chip_name_attr.attr,
244 	&hwirq_attr.attr,
245 	&type_attr.attr,
246 	&name_attr.attr,
247 	&actions_attr.attr,
248 	NULL
249 };
250 
251 static struct kobj_type irq_kobj_type = {
252 	.release	= irq_kobj_release,
253 	.sysfs_ops	= &kobj_sysfs_ops,
254 	.default_attrs	= irq_attrs,
255 };
256 
irq_sysfs_add(int irq,struct irq_desc * desc)257 static void irq_sysfs_add(int irq, struct irq_desc *desc)
258 {
259 	if (irq_kobj_base) {
260 		/*
261 		 * Continue even in case of failure as this is nothing
262 		 * crucial.
263 		 */
264 		if (kobject_add(&desc->kobj, irq_kobj_base, "%d", irq))
265 			pr_warn("Failed to add kobject for irq %d\n", irq);
266 	}
267 }
268 
irq_sysfs_init(void)269 static int __init irq_sysfs_init(void)
270 {
271 	struct irq_desc *desc;
272 	int irq;
273 
274 	/* Prevent concurrent irq alloc/free */
275 	irq_lock_sparse();
276 
277 	irq_kobj_base = kobject_create_and_add("irq", kernel_kobj);
278 	if (!irq_kobj_base) {
279 		irq_unlock_sparse();
280 		return -ENOMEM;
281 	}
282 
283 	/* Add the already allocated interrupts */
284 	for_each_irq_desc(irq, desc)
285 		irq_sysfs_add(irq, desc);
286 	irq_unlock_sparse();
287 
288 	return 0;
289 }
290 postcore_initcall(irq_sysfs_init);
291 
292 #else /* !CONFIG_SYSFS */
293 
294 static struct kobj_type irq_kobj_type = {
295 	.release	= irq_kobj_release,
296 };
297 
irq_sysfs_add(int irq,struct irq_desc * desc)298 static void irq_sysfs_add(int irq, struct irq_desc *desc) {}
299 
300 #endif /* CONFIG_SYSFS */
301 
302 static RADIX_TREE(irq_desc_tree, GFP_KERNEL);
303 
irq_insert_desc(unsigned int irq,struct irq_desc * desc)304 static void irq_insert_desc(unsigned int irq, struct irq_desc *desc)
305 {
306 	radix_tree_insert(&irq_desc_tree, irq, desc);
307 }
308 
irq_to_desc(unsigned int irq)309 struct irq_desc *irq_to_desc(unsigned int irq)
310 {
311 	return radix_tree_lookup(&irq_desc_tree, irq);
312 }
313 EXPORT_SYMBOL(irq_to_desc);
314 
delete_irq_desc(unsigned int irq)315 static void delete_irq_desc(unsigned int irq)
316 {
317 	radix_tree_delete(&irq_desc_tree, irq);
318 }
319 
320 #ifdef CONFIG_SMP
free_masks(struct irq_desc * desc)321 static void free_masks(struct irq_desc *desc)
322 {
323 #ifdef CONFIG_GENERIC_PENDING_IRQ
324 	free_cpumask_var(desc->pending_mask);
325 #endif
326 	free_cpumask_var(desc->irq_common_data.affinity);
327 }
328 #else
free_masks(struct irq_desc * desc)329 static inline void free_masks(struct irq_desc *desc) { }
330 #endif
331 
irq_lock_sparse(void)332 void irq_lock_sparse(void)
333 {
334 	mutex_lock(&sparse_irq_lock);
335 }
336 
irq_unlock_sparse(void)337 void irq_unlock_sparse(void)
338 {
339 	mutex_unlock(&sparse_irq_lock);
340 }
341 
alloc_desc(int irq,int node,unsigned int flags,const struct cpumask * affinity,struct module * owner)342 static struct irq_desc *alloc_desc(int irq, int node, unsigned int flags,
343 				   const struct cpumask *affinity,
344 				   struct module *owner)
345 {
346 	struct irq_desc *desc;
347 	gfp_t gfp = GFP_KERNEL;
348 
349 	desc = kzalloc_node(sizeof(*desc), gfp, node);
350 	if (!desc)
351 		return NULL;
352 	/* allocate based on nr_cpu_ids */
353 	desc->kstat_irqs = alloc_percpu(unsigned int);
354 	if (!desc->kstat_irqs)
355 		goto err_desc;
356 
357 	if (alloc_masks(desc, gfp, node))
358 		goto err_kstat;
359 
360 	raw_spin_lock_init(&desc->lock);
361 	lockdep_set_class(&desc->lock, &irq_desc_lock_class);
362 	init_rcu_head(&desc->rcu);
363 
364 	desc_set_defaults(irq, desc, node, affinity, owner);
365 	irqd_set(&desc->irq_data, flags);
366 	kobject_init(&desc->kobj, &irq_kobj_type);
367 
368 	return desc;
369 
370 err_kstat:
371 	free_percpu(desc->kstat_irqs);
372 err_desc:
373 	kfree(desc);
374 	return NULL;
375 }
376 
irq_kobj_release(struct kobject * kobj)377 static void irq_kobj_release(struct kobject *kobj)
378 {
379 	struct irq_desc *desc = container_of(kobj, struct irq_desc, kobj);
380 
381 	free_masks(desc);
382 	free_percpu(desc->kstat_irqs);
383 	kfree(desc);
384 }
385 
delayed_free_desc(struct rcu_head * rhp)386 static void delayed_free_desc(struct rcu_head *rhp)
387 {
388 	struct irq_desc *desc = container_of(rhp, struct irq_desc, rcu);
389 
390 	kobject_put(&desc->kobj);
391 }
392 
free_desc(unsigned int irq)393 static void free_desc(unsigned int irq)
394 {
395 	struct irq_desc *desc = irq_to_desc(irq);
396 
397 	unregister_irq_proc(irq, desc);
398 
399 	/*
400 	 * sparse_irq_lock protects also show_interrupts() and
401 	 * kstat_irq_usr(). Once we deleted the descriptor from the
402 	 * sparse tree we can free it. Access in proc will fail to
403 	 * lookup the descriptor.
404 	 *
405 	 * The sysfs entry must be serialized against a concurrent
406 	 * irq_sysfs_init() as well.
407 	 */
408 	kobject_del(&desc->kobj);
409 	delete_irq_desc(irq);
410 
411 	/*
412 	 * We free the descriptor, masks and stat fields via RCU. That
413 	 * allows demultiplex interrupts to do rcu based management of
414 	 * the child interrupts.
415 	 */
416 	call_rcu(&desc->rcu, delayed_free_desc);
417 }
418 
alloc_descs(unsigned int start,unsigned int cnt,int node,const struct cpumask * affinity,struct module * owner)419 static int alloc_descs(unsigned int start, unsigned int cnt, int node,
420 		       const struct cpumask *affinity, struct module *owner)
421 {
422 	const struct cpumask *mask = NULL;
423 	struct irq_desc *desc;
424 	unsigned int flags;
425 	int i;
426 
427 	/* Validate affinity mask(s) */
428 	if (affinity) {
429 		for (i = 0, mask = affinity; i < cnt; i++, mask++) {
430 			if (cpumask_empty(mask))
431 				return -EINVAL;
432 		}
433 	}
434 
435 	flags = affinity ? IRQD_AFFINITY_MANAGED : 0;
436 	mask = NULL;
437 
438 	for (i = 0; i < cnt; i++) {
439 		if (affinity) {
440 			node = cpu_to_node(cpumask_first(affinity));
441 			mask = affinity;
442 			affinity++;
443 		}
444 		desc = alloc_desc(start + i, node, flags, mask, owner);
445 		if (!desc)
446 			goto err;
447 		irq_insert_desc(start + i, desc);
448 		irq_sysfs_add(start + i, desc);
449 	}
450 	bitmap_set(allocated_irqs, start, cnt);
451 	return start;
452 
453 err:
454 	for (i--; i >= 0; i--)
455 		free_desc(start + i);
456 	return -ENOMEM;
457 }
458 
irq_expand_nr_irqs(unsigned int nr)459 static int irq_expand_nr_irqs(unsigned int nr)
460 {
461 	if (nr > IRQ_BITMAP_BITS)
462 		return -ENOMEM;
463 	nr_irqs = nr;
464 	return 0;
465 }
466 
early_irq_init(void)467 int __init early_irq_init(void)
468 {
469 	int i, initcnt, node = first_online_node;
470 	struct irq_desc *desc;
471 
472 	init_irq_default_affinity();
473 
474 	/* Let arch update nr_irqs and return the nr of preallocated irqs */
475 	initcnt = arch_probe_nr_irqs();
476 	printk(KERN_INFO "NR_IRQS:%d nr_irqs:%d %d\n", NR_IRQS, nr_irqs, initcnt);
477 
478 	if (WARN_ON(nr_irqs > IRQ_BITMAP_BITS))
479 		nr_irqs = IRQ_BITMAP_BITS;
480 
481 	if (WARN_ON(initcnt > IRQ_BITMAP_BITS))
482 		initcnt = IRQ_BITMAP_BITS;
483 
484 	if (initcnt > nr_irqs)
485 		nr_irqs = initcnt;
486 
487 	for (i = 0; i < initcnt; i++) {
488 		desc = alloc_desc(i, node, 0, NULL, NULL);
489 		set_bit(i, allocated_irqs);
490 		irq_insert_desc(i, desc);
491 	}
492 	return arch_early_irq_init();
493 }
494 
495 #else /* !CONFIG_SPARSE_IRQ */
496 
497 struct irq_desc irq_desc[NR_IRQS] __cacheline_aligned_in_smp = {
498 	[0 ... NR_IRQS-1] = {
499 		.handle_irq	= handle_bad_irq,
500 		.depth		= 1,
501 		.lock		= __RAW_SPIN_LOCK_UNLOCKED(irq_desc->lock),
502 	}
503 };
504 
early_irq_init(void)505 int __init early_irq_init(void)
506 {
507 	int count, i, node = first_online_node;
508 	struct irq_desc *desc;
509 
510 	init_irq_default_affinity();
511 
512 	printk(KERN_INFO "NR_IRQS:%d\n", NR_IRQS);
513 
514 	desc = irq_desc;
515 	count = ARRAY_SIZE(irq_desc);
516 
517 	for (i = 0; i < count; i++) {
518 		desc[i].kstat_irqs = alloc_percpu(unsigned int);
519 		alloc_masks(&desc[i], GFP_KERNEL, node);
520 		raw_spin_lock_init(&desc[i].lock);
521 		lockdep_set_class(&desc[i].lock, &irq_desc_lock_class);
522 		desc_set_defaults(i, &desc[i], node, NULL, NULL);
523 	}
524 	return arch_early_irq_init();
525 }
526 
irq_to_desc(unsigned int irq)527 struct irq_desc *irq_to_desc(unsigned int irq)
528 {
529 	return (irq < NR_IRQS) ? irq_desc + irq : NULL;
530 }
531 EXPORT_SYMBOL(irq_to_desc);
532 
free_desc(unsigned int irq)533 static void free_desc(unsigned int irq)
534 {
535 	struct irq_desc *desc = irq_to_desc(irq);
536 	unsigned long flags;
537 
538 	raw_spin_lock_irqsave(&desc->lock, flags);
539 	desc_set_defaults(irq, desc, irq_desc_get_node(desc), NULL, NULL);
540 	raw_spin_unlock_irqrestore(&desc->lock, flags);
541 }
542 
alloc_descs(unsigned int start,unsigned int cnt,int node,const struct cpumask * affinity,struct module * owner)543 static inline int alloc_descs(unsigned int start, unsigned int cnt, int node,
544 			      const struct cpumask *affinity,
545 			      struct module *owner)
546 {
547 	u32 i;
548 
549 	for (i = 0; i < cnt; i++) {
550 		struct irq_desc *desc = irq_to_desc(start + i);
551 
552 		desc->owner = owner;
553 	}
554 	bitmap_set(allocated_irqs, start, cnt);
555 	return start;
556 }
557 
irq_expand_nr_irqs(unsigned int nr)558 static int irq_expand_nr_irqs(unsigned int nr)
559 {
560 	return -ENOMEM;
561 }
562 
irq_mark_irq(unsigned int irq)563 void irq_mark_irq(unsigned int irq)
564 {
565 	mutex_lock(&sparse_irq_lock);
566 	bitmap_set(allocated_irqs, irq, 1);
567 	mutex_unlock(&sparse_irq_lock);
568 }
569 
570 #ifdef CONFIG_GENERIC_IRQ_LEGACY
irq_init_desc(unsigned int irq)571 void irq_init_desc(unsigned int irq)
572 {
573 	free_desc(irq);
574 }
575 #endif
576 
577 #endif /* !CONFIG_SPARSE_IRQ */
578 
579 /**
580  * generic_handle_irq - Invoke the handler for a particular irq
581  * @irq:	The irq number to handle
582  *
583  */
generic_handle_irq(unsigned int irq)584 int generic_handle_irq(unsigned int irq)
585 {
586 	struct irq_desc *desc = irq_to_desc(irq);
587 
588 	if (!desc)
589 		return -EINVAL;
590 	generic_handle_irq_desc(desc);
591 	return 0;
592 }
593 EXPORT_SYMBOL_GPL(generic_handle_irq);
594 
595 #ifdef CONFIG_HANDLE_DOMAIN_IRQ
596 /**
597  * __handle_domain_irq - Invoke the handler for a HW irq belonging to a domain
598  * @domain:	The domain where to perform the lookup
599  * @hwirq:	The HW irq number to convert to a logical one
600  * @lookup:	Whether to perform the domain lookup or not
601  * @regs:	Register file coming from the low-level handling code
602  *
603  * Returns:	0 on success, or -EINVAL if conversion has failed
604  */
__handle_domain_irq(struct irq_domain * domain,unsigned int hwirq,bool lookup,struct pt_regs * regs)605 int __handle_domain_irq(struct irq_domain *domain, unsigned int hwirq,
606 			bool lookup, struct pt_regs *regs)
607 {
608 	struct pt_regs *old_regs = set_irq_regs(regs);
609 	unsigned int irq = hwirq;
610 	int ret = 0;
611 
612 	irq_enter();
613 
614 #ifdef CONFIG_IRQ_DOMAIN
615 	if (lookup)
616 		irq = irq_find_mapping(domain, hwirq);
617 #endif
618 
619 	/*
620 	 * Some hardware gives randomly wrong interrupts.  Rather
621 	 * than crashing, do something sensible.
622 	 */
623 	if (unlikely(!irq || irq >= nr_irqs)) {
624 		ack_bad_irq(irq);
625 		ret = -EINVAL;
626 	} else {
627 		generic_handle_irq(irq);
628 	}
629 
630 	irq_exit();
631 	set_irq_regs(old_regs);
632 	return ret;
633 }
634 #endif
635 
636 /* Dynamic interrupt handling */
637 
638 /**
639  * irq_free_descs - free irq descriptors
640  * @from:	Start of descriptor range
641  * @cnt:	Number of consecutive irqs to free
642  */
irq_free_descs(unsigned int from,unsigned int cnt)643 void irq_free_descs(unsigned int from, unsigned int cnt)
644 {
645 	int i;
646 
647 	if (from >= nr_irqs || (from + cnt) > nr_irqs)
648 		return;
649 
650 	mutex_lock(&sparse_irq_lock);
651 	for (i = 0; i < cnt; i++)
652 		free_desc(from + i);
653 
654 	bitmap_clear(allocated_irqs, from, cnt);
655 	mutex_unlock(&sparse_irq_lock);
656 }
657 EXPORT_SYMBOL_GPL(irq_free_descs);
658 
659 /**
660  * irq_alloc_descs - allocate and initialize a range of irq descriptors
661  * @irq:	Allocate for specific irq number if irq >= 0
662  * @from:	Start the search from this irq number
663  * @cnt:	Number of consecutive irqs to allocate.
664  * @node:	Preferred node on which the irq descriptor should be allocated
665  * @owner:	Owning module (can be NULL)
666  * @affinity:	Optional pointer to an affinity mask array of size @cnt which
667  *		hints where the irq descriptors should be allocated and which
668  *		default affinities to use
669  *
670  * Returns the first irq number or error code
671  */
672 int __ref
__irq_alloc_descs(int irq,unsigned int from,unsigned int cnt,int node,struct module * owner,const struct cpumask * affinity)673 __irq_alloc_descs(int irq, unsigned int from, unsigned int cnt, int node,
674 		  struct module *owner, const struct cpumask *affinity)
675 {
676 	int start, ret;
677 
678 	if (!cnt)
679 		return -EINVAL;
680 
681 	if (irq >= 0) {
682 		if (from > irq)
683 			return -EINVAL;
684 		from = irq;
685 	} else {
686 		/*
687 		 * For interrupts which are freely allocated the
688 		 * architecture can force a lower bound to the @from
689 		 * argument. x86 uses this to exclude the GSI space.
690 		 */
691 		from = arch_dynirq_lower_bound(from);
692 	}
693 
694 	mutex_lock(&sparse_irq_lock);
695 
696 	start = bitmap_find_next_zero_area(allocated_irqs, IRQ_BITMAP_BITS,
697 					   from, cnt, 0);
698 	ret = -EEXIST;
699 	if (irq >=0 && start != irq)
700 		goto unlock;
701 
702 	if (start + cnt > nr_irqs) {
703 		ret = irq_expand_nr_irqs(start + cnt);
704 		if (ret)
705 			goto unlock;
706 	}
707 	ret = alloc_descs(start, cnt, node, affinity, owner);
708 unlock:
709 	mutex_unlock(&sparse_irq_lock);
710 	return ret;
711 }
712 EXPORT_SYMBOL_GPL(__irq_alloc_descs);
713 
714 #ifdef CONFIG_GENERIC_IRQ_LEGACY_ALLOC_HWIRQ
715 /**
716  * irq_alloc_hwirqs - Allocate an irq descriptor and initialize the hardware
717  * @cnt:	number of interrupts to allocate
718  * @node:	node on which to allocate
719  *
720  * Returns an interrupt number > 0 or 0, if the allocation fails.
721  */
irq_alloc_hwirqs(int cnt,int node)722 unsigned int irq_alloc_hwirqs(int cnt, int node)
723 {
724 	int i, irq = __irq_alloc_descs(-1, 0, cnt, node, NULL, NULL);
725 
726 	if (irq < 0)
727 		return 0;
728 
729 	for (i = irq; cnt > 0; i++, cnt--) {
730 		if (arch_setup_hwirq(i, node))
731 			goto err;
732 		irq_clear_status_flags(i, _IRQ_NOREQUEST);
733 	}
734 	return irq;
735 
736 err:
737 	for (i--; i >= irq; i--) {
738 		irq_set_status_flags(i, _IRQ_NOREQUEST | _IRQ_NOPROBE);
739 		arch_teardown_hwirq(i);
740 	}
741 	irq_free_descs(irq, cnt);
742 	return 0;
743 }
744 EXPORT_SYMBOL_GPL(irq_alloc_hwirqs);
745 
746 /**
747  * irq_free_hwirqs - Free irq descriptor and cleanup the hardware
748  * @from:	Free from irq number
749  * @cnt:	number of interrupts to free
750  *
751  */
irq_free_hwirqs(unsigned int from,int cnt)752 void irq_free_hwirqs(unsigned int from, int cnt)
753 {
754 	int i, j;
755 
756 	for (i = from, j = cnt; j > 0; i++, j--) {
757 		irq_set_status_flags(i, _IRQ_NOREQUEST | _IRQ_NOPROBE);
758 		arch_teardown_hwirq(i);
759 	}
760 	irq_free_descs(from, cnt);
761 }
762 EXPORT_SYMBOL_GPL(irq_free_hwirqs);
763 #endif
764 
765 /**
766  * irq_get_next_irq - get next allocated irq number
767  * @offset:	where to start the search
768  *
769  * Returns next irq number after offset or nr_irqs if none is found.
770  */
irq_get_next_irq(unsigned int offset)771 unsigned int irq_get_next_irq(unsigned int offset)
772 {
773 	return find_next_bit(allocated_irqs, nr_irqs, offset);
774 }
775 
776 struct irq_desc *
__irq_get_desc_lock(unsigned int irq,unsigned long * flags,bool bus,unsigned int check)777 __irq_get_desc_lock(unsigned int irq, unsigned long *flags, bool bus,
778 		    unsigned int check)
779 {
780 	struct irq_desc *desc = irq_to_desc(irq);
781 
782 	if (desc) {
783 		if (check & _IRQ_DESC_CHECK) {
784 			if ((check & _IRQ_DESC_PERCPU) &&
785 			    !irq_settings_is_per_cpu_devid(desc))
786 				return NULL;
787 
788 			if (!(check & _IRQ_DESC_PERCPU) &&
789 			    irq_settings_is_per_cpu_devid(desc))
790 				return NULL;
791 		}
792 
793 		if (bus)
794 			chip_bus_lock(desc);
795 		raw_spin_lock_irqsave(&desc->lock, *flags);
796 	}
797 	return desc;
798 }
799 
__irq_put_desc_unlock(struct irq_desc * desc,unsigned long flags,bool bus)800 void __irq_put_desc_unlock(struct irq_desc *desc, unsigned long flags, bool bus)
801 {
802 	raw_spin_unlock_irqrestore(&desc->lock, flags);
803 	if (bus)
804 		chip_bus_sync_unlock(desc);
805 }
806 
irq_set_percpu_devid_partition(unsigned int irq,const struct cpumask * affinity)807 int irq_set_percpu_devid_partition(unsigned int irq,
808 				   const struct cpumask *affinity)
809 {
810 	struct irq_desc *desc = irq_to_desc(irq);
811 
812 	if (!desc)
813 		return -EINVAL;
814 
815 	if (desc->percpu_enabled)
816 		return -EINVAL;
817 
818 	desc->percpu_enabled = kzalloc(sizeof(*desc->percpu_enabled), GFP_KERNEL);
819 
820 	if (!desc->percpu_enabled)
821 		return -ENOMEM;
822 
823 	if (affinity)
824 		desc->percpu_affinity = affinity;
825 	else
826 		desc->percpu_affinity = cpu_possible_mask;
827 
828 	irq_set_percpu_devid_flags(irq);
829 	return 0;
830 }
831 
irq_set_percpu_devid(unsigned int irq)832 int irq_set_percpu_devid(unsigned int irq)
833 {
834 	return irq_set_percpu_devid_partition(irq, NULL);
835 }
836 
irq_get_percpu_devid_partition(unsigned int irq,struct cpumask * affinity)837 int irq_get_percpu_devid_partition(unsigned int irq, struct cpumask *affinity)
838 {
839 	struct irq_desc *desc = irq_to_desc(irq);
840 
841 	if (!desc || !desc->percpu_enabled)
842 		return -EINVAL;
843 
844 	if (affinity)
845 		cpumask_copy(affinity, desc->percpu_affinity);
846 
847 	return 0;
848 }
849 
kstat_incr_irq_this_cpu(unsigned int irq)850 void kstat_incr_irq_this_cpu(unsigned int irq)
851 {
852 	kstat_incr_irqs_this_cpu(irq_to_desc(irq));
853 }
854 
855 /**
856  * kstat_irqs_cpu - Get the statistics for an interrupt on a cpu
857  * @irq:	The interrupt number
858  * @cpu:	The cpu number
859  *
860  * Returns the sum of interrupt counts on @cpu since boot for
861  * @irq. The caller must ensure that the interrupt is not removed
862  * concurrently.
863  */
kstat_irqs_cpu(unsigned int irq,int cpu)864 unsigned int kstat_irqs_cpu(unsigned int irq, int cpu)
865 {
866 	struct irq_desc *desc = irq_to_desc(irq);
867 
868 	return desc && desc->kstat_irqs ?
869 			*per_cpu_ptr(desc->kstat_irqs, cpu) : 0;
870 }
871 
872 /**
873  * kstat_irqs - Get the statistics for an interrupt
874  * @irq:	The interrupt number
875  *
876  * Returns the sum of interrupt counts on all cpus since boot for
877  * @irq. The caller must ensure that the interrupt is not removed
878  * concurrently.
879  */
kstat_irqs(unsigned int irq)880 unsigned int kstat_irqs(unsigned int irq)
881 {
882 	struct irq_desc *desc = irq_to_desc(irq);
883 	int cpu;
884 	unsigned int sum = 0;
885 
886 	if (!desc || !desc->kstat_irqs)
887 		return 0;
888 	for_each_possible_cpu(cpu)
889 		sum += *per_cpu_ptr(desc->kstat_irqs, cpu);
890 	return sum;
891 }
892 
893 /**
894  * kstat_irqs_usr - Get the statistics for an interrupt
895  * @irq:	The interrupt number
896  *
897  * Returns the sum of interrupt counts on all cpus since boot for
898  * @irq. Contrary to kstat_irqs() this can be called from any
899  * preemptible context. It's protected against concurrent removal of
900  * an interrupt descriptor when sparse irqs are enabled.
901  */
kstat_irqs_usr(unsigned int irq)902 unsigned int kstat_irqs_usr(unsigned int irq)
903 {
904 	unsigned int sum;
905 
906 	irq_lock_sparse();
907 	sum = kstat_irqs(irq);
908 	irq_unlock_sparse();
909 	return sum;
910 }
911