1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Copyright (C) 1992, 1998-2006 Linus Torvalds, Ingo Molnar
4  * Copyright (C) 2005-2006, Thomas Gleixner, Russell King
5  *
6  * This file contains the interrupt descriptor management code. Detailed
7  * information is available in Documentation/core-api/genericirq.rst
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 	alloc_bootmem_cpumask_var(&irq_default_affinity);
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 	if (!cpumask_available(irq_default_affinity))
44 		zalloc_cpumask_var(&irq_default_affinity, GFP_NOWAIT);
45 	if (cpumask_empty(irq_default_affinity))
46 		cpumask_setall(irq_default_affinity);
47 }
48 #else
init_irq_default_affinity(void)49 static void __init init_irq_default_affinity(void)
50 {
51 }
52 #endif
53 
54 #ifdef CONFIG_SMP
alloc_masks(struct irq_desc * desc,int node)55 static int alloc_masks(struct irq_desc *desc, int node)
56 {
57 	if (!zalloc_cpumask_var_node(&desc->irq_common_data.affinity,
58 				     GFP_KERNEL, node))
59 		return -ENOMEM;
60 
61 #ifdef CONFIG_GENERIC_IRQ_EFFECTIVE_AFF_MASK
62 	if (!zalloc_cpumask_var_node(&desc->irq_common_data.effective_affinity,
63 				     GFP_KERNEL, node)) {
64 		free_cpumask_var(desc->irq_common_data.affinity);
65 		return -ENOMEM;
66 	}
67 #endif
68 
69 #ifdef CONFIG_GENERIC_PENDING_IRQ
70 	if (!zalloc_cpumask_var_node(&desc->pending_mask, GFP_KERNEL, node)) {
71 #ifdef CONFIG_GENERIC_IRQ_EFFECTIVE_AFF_MASK
72 		free_cpumask_var(desc->irq_common_data.effective_affinity);
73 #endif
74 		free_cpumask_var(desc->irq_common_data.affinity);
75 		return -ENOMEM;
76 	}
77 #endif
78 	return 0;
79 }
80 
desc_smp_init(struct irq_desc * desc,int node,const struct cpumask * affinity)81 static void desc_smp_init(struct irq_desc *desc, int node,
82 			  const struct cpumask *affinity)
83 {
84 	if (!affinity)
85 		affinity = irq_default_affinity;
86 	cpumask_copy(desc->irq_common_data.affinity, affinity);
87 
88 #ifdef CONFIG_GENERIC_PENDING_IRQ
89 	cpumask_clear(desc->pending_mask);
90 #endif
91 #ifdef CONFIG_NUMA
92 	desc->irq_common_data.node = node;
93 #endif
94 }
95 
96 #else
97 static inline int
alloc_masks(struct irq_desc * desc,int node)98 alloc_masks(struct irq_desc *desc, int node) { return 0; }
99 static inline void
desc_smp_init(struct irq_desc * desc,int node,const struct cpumask * affinity)100 desc_smp_init(struct irq_desc *desc, int node, const struct cpumask *affinity) { }
101 #endif
102 
desc_set_defaults(unsigned int irq,struct irq_desc * desc,int node,const struct cpumask * affinity,struct module * owner)103 static void desc_set_defaults(unsigned int irq, struct irq_desc *desc, int node,
104 			      const struct cpumask *affinity, struct module *owner)
105 {
106 	int cpu;
107 
108 	desc->irq_common_data.handler_data = NULL;
109 	desc->irq_common_data.msi_desc = NULL;
110 
111 	desc->irq_data.common = &desc->irq_common_data;
112 	desc->irq_data.irq = irq;
113 	desc->irq_data.chip = &no_irq_chip;
114 	desc->irq_data.chip_data = NULL;
115 	irq_settings_clr_and_set(desc, ~0, _IRQ_DEFAULT_INIT_FLAGS);
116 	irqd_set(&desc->irq_data, IRQD_IRQ_DISABLED);
117 	irqd_set(&desc->irq_data, IRQD_IRQ_MASKED);
118 	desc->handle_irq = handle_bad_irq;
119 	desc->depth = 1;
120 	desc->irq_count = 0;
121 	desc->irqs_unhandled = 0;
122 	desc->name = NULL;
123 	desc->owner = owner;
124 	for_each_possible_cpu(cpu)
125 		*per_cpu_ptr(desc->kstat_irqs, cpu) = 0;
126 	desc_smp_init(desc, node, affinity);
127 }
128 
129 int nr_irqs = NR_IRQS;
130 EXPORT_SYMBOL_GPL(nr_irqs);
131 
132 static DEFINE_MUTEX(sparse_irq_lock);
133 static DECLARE_BITMAP(allocated_irqs, IRQ_BITMAP_BITS);
134 
135 #ifdef CONFIG_SPARSE_IRQ
136 
137 static void irq_kobj_release(struct kobject *kobj);
138 
139 #ifdef CONFIG_SYSFS
140 static struct kobject *irq_kobj_base;
141 
142 #define IRQ_ATTR_RO(_name) \
143 static struct kobj_attribute _name##_attr = __ATTR_RO(_name)
144 
per_cpu_count_show(struct kobject * kobj,struct kobj_attribute * attr,char * buf)145 static ssize_t per_cpu_count_show(struct kobject *kobj,
146 				  struct kobj_attribute *attr, char *buf)
147 {
148 	struct irq_desc *desc = container_of(kobj, struct irq_desc, kobj);
149 	int cpu, irq = desc->irq_data.irq;
150 	ssize_t ret = 0;
151 	char *p = "";
152 
153 	for_each_possible_cpu(cpu) {
154 		unsigned int c = kstat_irqs_cpu(irq, cpu);
155 
156 		ret += scnprintf(buf + ret, PAGE_SIZE - ret, "%s%u", p, c);
157 		p = ",";
158 	}
159 
160 	ret += scnprintf(buf + ret, PAGE_SIZE - ret, "\n");
161 	return ret;
162 }
163 IRQ_ATTR_RO(per_cpu_count);
164 
chip_name_show(struct kobject * kobj,struct kobj_attribute * attr,char * buf)165 static ssize_t chip_name_show(struct kobject *kobj,
166 			      struct kobj_attribute *attr, char *buf)
167 {
168 	struct irq_desc *desc = container_of(kobj, struct irq_desc, kobj);
169 	ssize_t ret = 0;
170 
171 	raw_spin_lock_irq(&desc->lock);
172 	if (desc->irq_data.chip && desc->irq_data.chip->name) {
173 		ret = scnprintf(buf, PAGE_SIZE, "%s\n",
174 				desc->irq_data.chip->name);
175 	}
176 	raw_spin_unlock_irq(&desc->lock);
177 
178 	return ret;
179 }
180 IRQ_ATTR_RO(chip_name);
181 
hwirq_show(struct kobject * kobj,struct kobj_attribute * attr,char * buf)182 static ssize_t hwirq_show(struct kobject *kobj,
183 			  struct kobj_attribute *attr, char *buf)
184 {
185 	struct irq_desc *desc = container_of(kobj, struct irq_desc, kobj);
186 	ssize_t ret = 0;
187 
188 	raw_spin_lock_irq(&desc->lock);
189 	if (desc->irq_data.domain)
190 		ret = sprintf(buf, "%d\n", (int)desc->irq_data.hwirq);
191 	raw_spin_unlock_irq(&desc->lock);
192 
193 	return ret;
194 }
195 IRQ_ATTR_RO(hwirq);
196 
type_show(struct kobject * kobj,struct kobj_attribute * attr,char * buf)197 static ssize_t type_show(struct kobject *kobj,
198 			 struct kobj_attribute *attr, char *buf)
199 {
200 	struct irq_desc *desc = container_of(kobj, struct irq_desc, kobj);
201 	ssize_t ret = 0;
202 
203 	raw_spin_lock_irq(&desc->lock);
204 	ret = sprintf(buf, "%s\n",
205 		      irqd_is_level_type(&desc->irq_data) ? "level" : "edge");
206 	raw_spin_unlock_irq(&desc->lock);
207 
208 	return ret;
209 
210 }
211 IRQ_ATTR_RO(type);
212 
wakeup_show(struct kobject * kobj,struct kobj_attribute * attr,char * buf)213 static ssize_t wakeup_show(struct kobject *kobj,
214 			   struct kobj_attribute *attr, char *buf)
215 {
216 	struct irq_desc *desc = container_of(kobj, struct irq_desc, kobj);
217 	ssize_t ret = 0;
218 
219 	raw_spin_lock_irq(&desc->lock);
220 	ret = sprintf(buf, "%s\n",
221 		      irqd_is_wakeup_set(&desc->irq_data) ? "enabled" : "disabled");
222 	raw_spin_unlock_irq(&desc->lock);
223 
224 	return ret;
225 
226 }
227 IRQ_ATTR_RO(wakeup);
228 
name_show(struct kobject * kobj,struct kobj_attribute * attr,char * buf)229 static ssize_t name_show(struct kobject *kobj,
230 			 struct kobj_attribute *attr, char *buf)
231 {
232 	struct irq_desc *desc = container_of(kobj, struct irq_desc, kobj);
233 	ssize_t ret = 0;
234 
235 	raw_spin_lock_irq(&desc->lock);
236 	if (desc->name)
237 		ret = scnprintf(buf, PAGE_SIZE, "%s\n", desc->name);
238 	raw_spin_unlock_irq(&desc->lock);
239 
240 	return ret;
241 }
242 IRQ_ATTR_RO(name);
243 
actions_show(struct kobject * kobj,struct kobj_attribute * attr,char * buf)244 static ssize_t actions_show(struct kobject *kobj,
245 			    struct kobj_attribute *attr, char *buf)
246 {
247 	struct irq_desc *desc = container_of(kobj, struct irq_desc, kobj);
248 	struct irqaction *action;
249 	ssize_t ret = 0;
250 	char *p = "";
251 
252 	raw_spin_lock_irq(&desc->lock);
253 	for (action = desc->action; action != NULL; action = action->next) {
254 		ret += scnprintf(buf + ret, PAGE_SIZE - ret, "%s%s",
255 				 p, action->name);
256 		p = ",";
257 	}
258 	raw_spin_unlock_irq(&desc->lock);
259 
260 	if (ret)
261 		ret += scnprintf(buf + ret, PAGE_SIZE - ret, "\n");
262 
263 	return ret;
264 }
265 IRQ_ATTR_RO(actions);
266 
267 static struct attribute *irq_attrs[] = {
268 	&per_cpu_count_attr.attr,
269 	&chip_name_attr.attr,
270 	&hwirq_attr.attr,
271 	&type_attr.attr,
272 	&wakeup_attr.attr,
273 	&name_attr.attr,
274 	&actions_attr.attr,
275 	NULL
276 };
277 
278 static struct kobj_type irq_kobj_type = {
279 	.release	= irq_kobj_release,
280 	.sysfs_ops	= &kobj_sysfs_ops,
281 	.default_attrs	= irq_attrs,
282 };
283 
irq_sysfs_add(int irq,struct irq_desc * desc)284 static void irq_sysfs_add(int irq, struct irq_desc *desc)
285 {
286 	if (irq_kobj_base) {
287 		/*
288 		 * Continue even in case of failure as this is nothing
289 		 * crucial.
290 		 */
291 		if (kobject_add(&desc->kobj, irq_kobj_base, "%d", irq))
292 			pr_warn("Failed to add kobject for irq %d\n", irq);
293 	}
294 }
295 
irq_sysfs_init(void)296 static int __init irq_sysfs_init(void)
297 {
298 	struct irq_desc *desc;
299 	int irq;
300 
301 	/* Prevent concurrent irq alloc/free */
302 	irq_lock_sparse();
303 
304 	irq_kobj_base = kobject_create_and_add("irq", kernel_kobj);
305 	if (!irq_kobj_base) {
306 		irq_unlock_sparse();
307 		return -ENOMEM;
308 	}
309 
310 	/* Add the already allocated interrupts */
311 	for_each_irq_desc(irq, desc)
312 		irq_sysfs_add(irq, desc);
313 	irq_unlock_sparse();
314 
315 	return 0;
316 }
317 postcore_initcall(irq_sysfs_init);
318 
319 #else /* !CONFIG_SYSFS */
320 
321 static struct kobj_type irq_kobj_type = {
322 	.release	= irq_kobj_release,
323 };
324 
irq_sysfs_add(int irq,struct irq_desc * desc)325 static void irq_sysfs_add(int irq, struct irq_desc *desc) {}
326 
327 #endif /* CONFIG_SYSFS */
328 
329 static RADIX_TREE(irq_desc_tree, GFP_KERNEL);
330 
irq_insert_desc(unsigned int irq,struct irq_desc * desc)331 static void irq_insert_desc(unsigned int irq, struct irq_desc *desc)
332 {
333 	radix_tree_insert(&irq_desc_tree, irq, desc);
334 }
335 
irq_to_desc(unsigned int irq)336 struct irq_desc *irq_to_desc(unsigned int irq)
337 {
338 	return radix_tree_lookup(&irq_desc_tree, irq);
339 }
340 EXPORT_SYMBOL(irq_to_desc);
341 
delete_irq_desc(unsigned int irq)342 static void delete_irq_desc(unsigned int irq)
343 {
344 	radix_tree_delete(&irq_desc_tree, irq);
345 }
346 
347 #ifdef CONFIG_SMP
free_masks(struct irq_desc * desc)348 static void free_masks(struct irq_desc *desc)
349 {
350 #ifdef CONFIG_GENERIC_PENDING_IRQ
351 	free_cpumask_var(desc->pending_mask);
352 #endif
353 	free_cpumask_var(desc->irq_common_data.affinity);
354 #ifdef CONFIG_GENERIC_IRQ_EFFECTIVE_AFF_MASK
355 	free_cpumask_var(desc->irq_common_data.effective_affinity);
356 #endif
357 }
358 #else
free_masks(struct irq_desc * desc)359 static inline void free_masks(struct irq_desc *desc) { }
360 #endif
361 
irq_lock_sparse(void)362 void irq_lock_sparse(void)
363 {
364 	mutex_lock(&sparse_irq_lock);
365 }
366 
irq_unlock_sparse(void)367 void irq_unlock_sparse(void)
368 {
369 	mutex_unlock(&sparse_irq_lock);
370 }
371 
alloc_desc(int irq,int node,unsigned int flags,const struct cpumask * affinity,struct module * owner)372 static struct irq_desc *alloc_desc(int irq, int node, unsigned int flags,
373 				   const struct cpumask *affinity,
374 				   struct module *owner)
375 {
376 	struct irq_desc *desc;
377 
378 	desc = kzalloc_node(sizeof(*desc), GFP_KERNEL, node);
379 	if (!desc)
380 		return NULL;
381 	/* allocate based on nr_cpu_ids */
382 	desc->kstat_irqs = alloc_percpu(unsigned int);
383 	if (!desc->kstat_irqs)
384 		goto err_desc;
385 
386 	if (alloc_masks(desc, node))
387 		goto err_kstat;
388 
389 	raw_spin_lock_init(&desc->lock);
390 	lockdep_set_class(&desc->lock, &irq_desc_lock_class);
391 	mutex_init(&desc->request_mutex);
392 	init_rcu_head(&desc->rcu);
393 
394 	desc_set_defaults(irq, desc, node, affinity, owner);
395 	irqd_set(&desc->irq_data, flags);
396 	kobject_init(&desc->kobj, &irq_kobj_type);
397 
398 	return desc;
399 
400 err_kstat:
401 	free_percpu(desc->kstat_irqs);
402 err_desc:
403 	kfree(desc);
404 	return NULL;
405 }
406 
irq_kobj_release(struct kobject * kobj)407 static void irq_kobj_release(struct kobject *kobj)
408 {
409 	struct irq_desc *desc = container_of(kobj, struct irq_desc, kobj);
410 
411 	free_masks(desc);
412 	free_percpu(desc->kstat_irqs);
413 	kfree(desc);
414 }
415 
delayed_free_desc(struct rcu_head * rhp)416 static void delayed_free_desc(struct rcu_head *rhp)
417 {
418 	struct irq_desc *desc = container_of(rhp, struct irq_desc, rcu);
419 
420 	kobject_put(&desc->kobj);
421 }
422 
free_desc(unsigned int irq)423 static void free_desc(unsigned int irq)
424 {
425 	struct irq_desc *desc = irq_to_desc(irq);
426 
427 	irq_remove_debugfs_entry(desc);
428 	unregister_irq_proc(irq, desc);
429 
430 	/*
431 	 * sparse_irq_lock protects also show_interrupts() and
432 	 * kstat_irq_usr(). Once we deleted the descriptor from the
433 	 * sparse tree we can free it. Access in proc will fail to
434 	 * lookup the descriptor.
435 	 *
436 	 * The sysfs entry must be serialized against a concurrent
437 	 * irq_sysfs_init() as well.
438 	 */
439 	kobject_del(&desc->kobj);
440 	delete_irq_desc(irq);
441 
442 	/*
443 	 * We free the descriptor, masks and stat fields via RCU. That
444 	 * allows demultiplex interrupts to do rcu based management of
445 	 * the child interrupts.
446 	 * This also allows us to use rcu in kstat_irqs_usr().
447 	 */
448 	call_rcu(&desc->rcu, delayed_free_desc);
449 }
450 
alloc_descs(unsigned int start,unsigned int cnt,int node,const struct cpumask * affinity,struct module * owner)451 static int alloc_descs(unsigned int start, unsigned int cnt, int node,
452 		       const struct cpumask *affinity, struct module *owner)
453 {
454 	const struct cpumask *mask = NULL;
455 	struct irq_desc *desc;
456 	unsigned int flags;
457 	int i;
458 
459 	/* Validate affinity mask(s) */
460 	if (affinity) {
461 		for (i = 0, mask = affinity; i < cnt; i++, mask++) {
462 			if (cpumask_empty(mask))
463 				return -EINVAL;
464 		}
465 	}
466 
467 	flags = affinity ? IRQD_AFFINITY_MANAGED | IRQD_MANAGED_SHUTDOWN : 0;
468 	mask = NULL;
469 
470 	for (i = 0; i < cnt; i++) {
471 		if (affinity) {
472 			node = cpu_to_node(cpumask_first(affinity));
473 			mask = affinity;
474 			affinity++;
475 		}
476 		desc = alloc_desc(start + i, node, flags, mask, owner);
477 		if (!desc)
478 			goto err;
479 		irq_insert_desc(start + i, desc);
480 		irq_sysfs_add(start + i, desc);
481 		irq_add_debugfs_entry(start + i, desc);
482 	}
483 	bitmap_set(allocated_irqs, start, cnt);
484 	return start;
485 
486 err:
487 	for (i--; i >= 0; i--)
488 		free_desc(start + i);
489 	return -ENOMEM;
490 }
491 
irq_expand_nr_irqs(unsigned int nr)492 static int irq_expand_nr_irqs(unsigned int nr)
493 {
494 	if (nr > IRQ_BITMAP_BITS)
495 		return -ENOMEM;
496 	nr_irqs = nr;
497 	return 0;
498 }
499 
early_irq_init(void)500 int __init early_irq_init(void)
501 {
502 	int i, initcnt, node = first_online_node;
503 	struct irq_desc *desc;
504 
505 	init_irq_default_affinity();
506 
507 	/* Let arch update nr_irqs and return the nr of preallocated irqs */
508 	initcnt = arch_probe_nr_irqs();
509 	printk(KERN_INFO "NR_IRQS: %d, nr_irqs: %d, preallocated irqs: %d\n",
510 	       NR_IRQS, nr_irqs, initcnt);
511 
512 	if (WARN_ON(nr_irqs > IRQ_BITMAP_BITS))
513 		nr_irqs = IRQ_BITMAP_BITS;
514 
515 	if (WARN_ON(initcnt > IRQ_BITMAP_BITS))
516 		initcnt = IRQ_BITMAP_BITS;
517 
518 	if (initcnt > nr_irqs)
519 		nr_irqs = initcnt;
520 
521 	for (i = 0; i < initcnt; i++) {
522 		desc = alloc_desc(i, node, 0, NULL, NULL);
523 		set_bit(i, allocated_irqs);
524 		irq_insert_desc(i, desc);
525 	}
526 	return arch_early_irq_init();
527 }
528 
529 #else /* !CONFIG_SPARSE_IRQ */
530 
531 struct irq_desc irq_desc[NR_IRQS] __cacheline_aligned_in_smp = {
532 	[0 ... NR_IRQS-1] = {
533 		.handle_irq	= handle_bad_irq,
534 		.depth		= 1,
535 		.lock		= __RAW_SPIN_LOCK_UNLOCKED(irq_desc->lock),
536 	}
537 };
538 
early_irq_init(void)539 int __init early_irq_init(void)
540 {
541 	int count, i, node = first_online_node;
542 	struct irq_desc *desc;
543 
544 	init_irq_default_affinity();
545 
546 	printk(KERN_INFO "NR_IRQS: %d\n", NR_IRQS);
547 
548 	desc = irq_desc;
549 	count = ARRAY_SIZE(irq_desc);
550 
551 	for (i = 0; i < count; i++) {
552 		desc[i].kstat_irqs = alloc_percpu(unsigned int);
553 		alloc_masks(&desc[i], node);
554 		raw_spin_lock_init(&desc[i].lock);
555 		lockdep_set_class(&desc[i].lock, &irq_desc_lock_class);
556 		desc_set_defaults(i, &desc[i], node, NULL, NULL);
557 	}
558 	return arch_early_irq_init();
559 }
560 
irq_to_desc(unsigned int irq)561 struct irq_desc *irq_to_desc(unsigned int irq)
562 {
563 	return (irq < NR_IRQS) ? irq_desc + irq : NULL;
564 }
565 EXPORT_SYMBOL(irq_to_desc);
566 
free_desc(unsigned int irq)567 static void free_desc(unsigned int irq)
568 {
569 	struct irq_desc *desc = irq_to_desc(irq);
570 	unsigned long flags;
571 
572 	raw_spin_lock_irqsave(&desc->lock, flags);
573 	desc_set_defaults(irq, desc, irq_desc_get_node(desc), NULL, NULL);
574 	raw_spin_unlock_irqrestore(&desc->lock, flags);
575 }
576 
alloc_descs(unsigned int start,unsigned int cnt,int node,const struct cpumask * affinity,struct module * owner)577 static inline int alloc_descs(unsigned int start, unsigned int cnt, int node,
578 			      const struct cpumask *affinity,
579 			      struct module *owner)
580 {
581 	u32 i;
582 
583 	for (i = 0; i < cnt; i++) {
584 		struct irq_desc *desc = irq_to_desc(start + i);
585 
586 		desc->owner = owner;
587 	}
588 	bitmap_set(allocated_irqs, start, cnt);
589 	return start;
590 }
591 
irq_expand_nr_irqs(unsigned int nr)592 static int irq_expand_nr_irqs(unsigned int nr)
593 {
594 	return -ENOMEM;
595 }
596 
irq_mark_irq(unsigned int irq)597 void irq_mark_irq(unsigned int irq)
598 {
599 	mutex_lock(&sparse_irq_lock);
600 	bitmap_set(allocated_irqs, irq, 1);
601 	mutex_unlock(&sparse_irq_lock);
602 }
603 
604 #ifdef CONFIG_GENERIC_IRQ_LEGACY
irq_init_desc(unsigned int irq)605 void irq_init_desc(unsigned int irq)
606 {
607 	free_desc(irq);
608 }
609 #endif
610 
611 #endif /* !CONFIG_SPARSE_IRQ */
612 
613 /**
614  * generic_handle_irq - Invoke the handler for a particular irq
615  * @irq:	The irq number to handle
616  *
617  */
generic_handle_irq(unsigned int irq)618 int generic_handle_irq(unsigned int irq)
619 {
620 	struct irq_desc *desc = irq_to_desc(irq);
621 
622 	if (!desc)
623 		return -EINVAL;
624 	generic_handle_irq_desc(desc);
625 	return 0;
626 }
627 EXPORT_SYMBOL_GPL(generic_handle_irq);
628 
629 #ifdef CONFIG_HANDLE_DOMAIN_IRQ
630 /**
631  * __handle_domain_irq - Invoke the handler for a HW irq belonging to a domain
632  * @domain:	The domain where to perform the lookup
633  * @hwirq:	The HW irq number to convert to a logical one
634  * @lookup:	Whether to perform the domain lookup or not
635  * @regs:	Register file coming from the low-level handling code
636  *
637  * Returns:	0 on success, or -EINVAL if conversion has failed
638  */
__handle_domain_irq(struct irq_domain * domain,unsigned int hwirq,bool lookup,struct pt_regs * regs)639 int __handle_domain_irq(struct irq_domain *domain, unsigned int hwirq,
640 			bool lookup, struct pt_regs *regs)
641 {
642 	struct pt_regs *old_regs = set_irq_regs(regs);
643 	unsigned int irq = hwirq;
644 	int ret = 0;
645 
646 	irq_enter();
647 
648 #ifdef CONFIG_IRQ_DOMAIN
649 	if (lookup)
650 		irq = irq_find_mapping(domain, hwirq);
651 #endif
652 
653 	/*
654 	 * Some hardware gives randomly wrong interrupts.  Rather
655 	 * than crashing, do something sensible.
656 	 */
657 	if (unlikely(!irq || irq >= nr_irqs)) {
658 		ack_bad_irq(irq);
659 		ret = -EINVAL;
660 	} else {
661 		generic_handle_irq(irq);
662 	}
663 
664 	irq_exit();
665 	set_irq_regs(old_regs);
666 	return ret;
667 }
668 #endif
669 
670 /* Dynamic interrupt handling */
671 
672 /**
673  * irq_free_descs - free irq descriptors
674  * @from:	Start of descriptor range
675  * @cnt:	Number of consecutive irqs to free
676  */
irq_free_descs(unsigned int from,unsigned int cnt)677 void irq_free_descs(unsigned int from, unsigned int cnt)
678 {
679 	int i;
680 
681 	if (from >= nr_irqs || (from + cnt) > nr_irqs)
682 		return;
683 
684 	mutex_lock(&sparse_irq_lock);
685 	for (i = 0; i < cnt; i++)
686 		free_desc(from + i);
687 
688 	bitmap_clear(allocated_irqs, from, cnt);
689 	mutex_unlock(&sparse_irq_lock);
690 }
691 EXPORT_SYMBOL_GPL(irq_free_descs);
692 
693 /**
694  * irq_alloc_descs - allocate and initialize a range of irq descriptors
695  * @irq:	Allocate for specific irq number if irq >= 0
696  * @from:	Start the search from this irq number
697  * @cnt:	Number of consecutive irqs to allocate.
698  * @node:	Preferred node on which the irq descriptor should be allocated
699  * @owner:	Owning module (can be NULL)
700  * @affinity:	Optional pointer to an affinity mask array of size @cnt which
701  *		hints where the irq descriptors should be allocated and which
702  *		default affinities to use
703  *
704  * Returns the first irq number or error code
705  */
706 int __ref
__irq_alloc_descs(int irq,unsigned int from,unsigned int cnt,int node,struct module * owner,const struct cpumask * affinity)707 __irq_alloc_descs(int irq, unsigned int from, unsigned int cnt, int node,
708 		  struct module *owner, const struct cpumask *affinity)
709 {
710 	int start, ret;
711 
712 	if (!cnt)
713 		return -EINVAL;
714 
715 	if (irq >= 0) {
716 		if (from > irq)
717 			return -EINVAL;
718 		from = irq;
719 	} else {
720 		/*
721 		 * For interrupts which are freely allocated the
722 		 * architecture can force a lower bound to the @from
723 		 * argument. x86 uses this to exclude the GSI space.
724 		 */
725 		from = arch_dynirq_lower_bound(from);
726 	}
727 
728 	mutex_lock(&sparse_irq_lock);
729 
730 	start = bitmap_find_next_zero_area(allocated_irqs, IRQ_BITMAP_BITS,
731 					   from, cnt, 0);
732 	ret = -EEXIST;
733 	if (irq >=0 && start != irq)
734 		goto unlock;
735 
736 	if (start + cnt > nr_irqs) {
737 		ret = irq_expand_nr_irqs(start + cnt);
738 		if (ret)
739 			goto unlock;
740 	}
741 	ret = alloc_descs(start, cnt, node, affinity, owner);
742 unlock:
743 	mutex_unlock(&sparse_irq_lock);
744 	return ret;
745 }
746 EXPORT_SYMBOL_GPL(__irq_alloc_descs);
747 
748 #ifdef CONFIG_GENERIC_IRQ_LEGACY_ALLOC_HWIRQ
749 /**
750  * irq_alloc_hwirqs - Allocate an irq descriptor and initialize the hardware
751  * @cnt:	number of interrupts to allocate
752  * @node:	node on which to allocate
753  *
754  * Returns an interrupt number > 0 or 0, if the allocation fails.
755  */
irq_alloc_hwirqs(int cnt,int node)756 unsigned int irq_alloc_hwirqs(int cnt, int node)
757 {
758 	int i, irq = __irq_alloc_descs(-1, 0, cnt, node, NULL, NULL);
759 
760 	if (irq < 0)
761 		return 0;
762 
763 	for (i = irq; cnt > 0; i++, cnt--) {
764 		if (arch_setup_hwirq(i, node))
765 			goto err;
766 		irq_clear_status_flags(i, _IRQ_NOREQUEST);
767 	}
768 	return irq;
769 
770 err:
771 	for (i--; i >= irq; i--) {
772 		irq_set_status_flags(i, _IRQ_NOREQUEST | _IRQ_NOPROBE);
773 		arch_teardown_hwirq(i);
774 	}
775 	irq_free_descs(irq, cnt);
776 	return 0;
777 }
778 EXPORT_SYMBOL_GPL(irq_alloc_hwirqs);
779 
780 /**
781  * irq_free_hwirqs - Free irq descriptor and cleanup the hardware
782  * @from:	Free from irq number
783  * @cnt:	number of interrupts to free
784  *
785  */
irq_free_hwirqs(unsigned int from,int cnt)786 void irq_free_hwirqs(unsigned int from, int cnt)
787 {
788 	int i, j;
789 
790 	for (i = from, j = cnt; j > 0; i++, j--) {
791 		irq_set_status_flags(i, _IRQ_NOREQUEST | _IRQ_NOPROBE);
792 		arch_teardown_hwirq(i);
793 	}
794 	irq_free_descs(from, cnt);
795 }
796 EXPORT_SYMBOL_GPL(irq_free_hwirqs);
797 #endif
798 
799 /**
800  * irq_get_next_irq - get next allocated irq number
801  * @offset:	where to start the search
802  *
803  * Returns next irq number after offset or nr_irqs if none is found.
804  */
irq_get_next_irq(unsigned int offset)805 unsigned int irq_get_next_irq(unsigned int offset)
806 {
807 	return find_next_bit(allocated_irqs, nr_irqs, offset);
808 }
809 
810 struct irq_desc *
__irq_get_desc_lock(unsigned int irq,unsigned long * flags,bool bus,unsigned int check)811 __irq_get_desc_lock(unsigned int irq, unsigned long *flags, bool bus,
812 		    unsigned int check)
813 {
814 	struct irq_desc *desc = irq_to_desc(irq);
815 
816 	if (desc) {
817 		if (check & _IRQ_DESC_CHECK) {
818 			if ((check & _IRQ_DESC_PERCPU) &&
819 			    !irq_settings_is_per_cpu_devid(desc))
820 				return NULL;
821 
822 			if (!(check & _IRQ_DESC_PERCPU) &&
823 			    irq_settings_is_per_cpu_devid(desc))
824 				return NULL;
825 		}
826 
827 		if (bus)
828 			chip_bus_lock(desc);
829 		raw_spin_lock_irqsave(&desc->lock, *flags);
830 	}
831 	return desc;
832 }
833 
__irq_put_desc_unlock(struct irq_desc * desc,unsigned long flags,bool bus)834 void __irq_put_desc_unlock(struct irq_desc *desc, unsigned long flags, bool bus)
835 {
836 	raw_spin_unlock_irqrestore(&desc->lock, flags);
837 	if (bus)
838 		chip_bus_sync_unlock(desc);
839 }
840 
irq_set_percpu_devid_partition(unsigned int irq,const struct cpumask * affinity)841 int irq_set_percpu_devid_partition(unsigned int irq,
842 				   const struct cpumask *affinity)
843 {
844 	struct irq_desc *desc = irq_to_desc(irq);
845 
846 	if (!desc)
847 		return -EINVAL;
848 
849 	if (desc->percpu_enabled)
850 		return -EINVAL;
851 
852 	desc->percpu_enabled = kzalloc(sizeof(*desc->percpu_enabled), GFP_KERNEL);
853 
854 	if (!desc->percpu_enabled)
855 		return -ENOMEM;
856 
857 	if (affinity)
858 		desc->percpu_affinity = affinity;
859 	else
860 		desc->percpu_affinity = cpu_possible_mask;
861 
862 	irq_set_percpu_devid_flags(irq);
863 	return 0;
864 }
865 
irq_set_percpu_devid(unsigned int irq)866 int irq_set_percpu_devid(unsigned int irq)
867 {
868 	return irq_set_percpu_devid_partition(irq, NULL);
869 }
870 
irq_get_percpu_devid_partition(unsigned int irq,struct cpumask * affinity)871 int irq_get_percpu_devid_partition(unsigned int irq, struct cpumask *affinity)
872 {
873 	struct irq_desc *desc = irq_to_desc(irq);
874 
875 	if (!desc || !desc->percpu_enabled)
876 		return -EINVAL;
877 
878 	if (affinity)
879 		cpumask_copy(affinity, desc->percpu_affinity);
880 
881 	return 0;
882 }
883 EXPORT_SYMBOL_GPL(irq_get_percpu_devid_partition);
884 
kstat_incr_irq_this_cpu(unsigned int irq)885 void kstat_incr_irq_this_cpu(unsigned int irq)
886 {
887 	kstat_incr_irqs_this_cpu(irq_to_desc(irq));
888 }
889 
890 /**
891  * kstat_irqs_cpu - Get the statistics for an interrupt on a cpu
892  * @irq:	The interrupt number
893  * @cpu:	The cpu number
894  *
895  * Returns the sum of interrupt counts on @cpu since boot for
896  * @irq. The caller must ensure that the interrupt is not removed
897  * concurrently.
898  */
kstat_irqs_cpu(unsigned int irq,int cpu)899 unsigned int kstat_irqs_cpu(unsigned int irq, int cpu)
900 {
901 	struct irq_desc *desc = irq_to_desc(irq);
902 
903 	return desc && desc->kstat_irqs ?
904 			*per_cpu_ptr(desc->kstat_irqs, cpu) : 0;
905 }
906 
907 /**
908  * kstat_irqs - Get the statistics for an interrupt
909  * @irq:	The interrupt number
910  *
911  * Returns the sum of interrupt counts on all cpus since boot for
912  * @irq. The caller must ensure that the interrupt is not removed
913  * concurrently.
914  */
kstat_irqs(unsigned int irq)915 unsigned int kstat_irqs(unsigned int irq)
916 {
917 	struct irq_desc *desc = irq_to_desc(irq);
918 	int cpu;
919 	unsigned int sum = 0;
920 
921 	if (!desc || !desc->kstat_irqs)
922 		return 0;
923 	for_each_possible_cpu(cpu)
924 		sum += *per_cpu_ptr(desc->kstat_irqs, cpu);
925 	return sum;
926 }
927 
928 /**
929  * kstat_irqs_usr - Get the statistics for an interrupt
930  * @irq:	The interrupt number
931  *
932  * Returns the sum of interrupt counts on all cpus since boot for @irq.
933  * Contrary to kstat_irqs() this can be called from any context.
934  * It uses rcu since a concurrent removal of an interrupt descriptor is
935  * observing an rcu grace period before delayed_free_desc()/irq_kobj_release().
936  */
kstat_irqs_usr(unsigned int irq)937 unsigned int kstat_irqs_usr(unsigned int irq)
938 {
939 	unsigned int sum;
940 
941 	rcu_read_lock();
942 	sum = kstat_irqs(irq);
943 	rcu_read_unlock();
944 	return sum;
945 }
946