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/maple_tree.h>
16 #include <linux/irqdomain.h>
17 #include <linux/sysfs.h>
18 
19 #include "internals.h"
20 
21 /*
22  * lockdep: we want to handle all irq_desc locks as a single lock-class:
23  */
24 static struct lock_class_key irq_desc_lock_class;
25 
26 #if defined(CONFIG_SMP)
irq_affinity_setup(char * str)27 static int __init irq_affinity_setup(char *str)
28 {
29 	alloc_bootmem_cpumask_var(&irq_default_affinity);
30 	cpulist_parse(str, irq_default_affinity);
31 	/*
32 	 * Set at least the boot cpu. We don't want to end up with
33 	 * bugreports caused by random commandline masks
34 	 */
35 	cpumask_set_cpu(smp_processor_id(), irq_default_affinity);
36 	return 1;
37 }
38 __setup("irqaffinity=", irq_affinity_setup);
39 
init_irq_default_affinity(void)40 static void __init init_irq_default_affinity(void)
41 {
42 	if (!cpumask_available(irq_default_affinity))
43 		zalloc_cpumask_var(&irq_default_affinity, GFP_NOWAIT);
44 	if (cpumask_empty(irq_default_affinity))
45 		cpumask_setall(irq_default_affinity);
46 }
47 #else
init_irq_default_affinity(void)48 static void __init init_irq_default_affinity(void)
49 {
50 }
51 #endif
52 
53 #ifdef CONFIG_SMP
alloc_masks(struct irq_desc * desc,int node)54 static int alloc_masks(struct irq_desc *desc, int node)
55 {
56 	if (!zalloc_cpumask_var_node(&desc->irq_common_data.affinity,
57 				     GFP_KERNEL, node))
58 		return -ENOMEM;
59 
60 #ifdef CONFIG_GENERIC_IRQ_EFFECTIVE_AFF_MASK
61 	if (!zalloc_cpumask_var_node(&desc->irq_common_data.effective_affinity,
62 				     GFP_KERNEL, node)) {
63 		free_cpumask_var(desc->irq_common_data.affinity);
64 		return -ENOMEM;
65 	}
66 #endif
67 
68 #ifdef CONFIG_GENERIC_PENDING_IRQ
69 	if (!zalloc_cpumask_var_node(&desc->pending_mask, GFP_KERNEL, node)) {
70 #ifdef CONFIG_GENERIC_IRQ_EFFECTIVE_AFF_MASK
71 		free_cpumask_var(desc->irq_common_data.effective_affinity);
72 #endif
73 		free_cpumask_var(desc->irq_common_data.affinity);
74 		return -ENOMEM;
75 	}
76 #endif
77 	return 0;
78 }
79 
desc_smp_init(struct irq_desc * desc,int node,const struct cpumask * affinity)80 static void desc_smp_init(struct irq_desc *desc, int node,
81 			  const struct cpumask *affinity)
82 {
83 	if (!affinity)
84 		affinity = irq_default_affinity;
85 	cpumask_copy(desc->irq_common_data.affinity, affinity);
86 
87 #ifdef CONFIG_GENERIC_PENDING_IRQ
88 	cpumask_clear(desc->pending_mask);
89 #endif
90 #ifdef CONFIG_NUMA
91 	desc->irq_common_data.node = node;
92 #endif
93 }
94 
95 #else
96 static inline int
alloc_masks(struct irq_desc * desc,int node)97 alloc_masks(struct irq_desc *desc, int node) { return 0; }
98 static inline void
desc_smp_init(struct irq_desc * desc,int node,const struct cpumask * affinity)99 desc_smp_init(struct irq_desc *desc, int node, const struct cpumask *affinity) { }
100 #endif
101 
desc_set_defaults(unsigned int irq,struct irq_desc * desc,int node,const struct cpumask * affinity,struct module * owner)102 static void desc_set_defaults(unsigned int irq, struct irq_desc *desc, int node,
103 			      const struct cpumask *affinity, struct module *owner)
104 {
105 	int cpu;
106 
107 	desc->irq_common_data.handler_data = NULL;
108 	desc->irq_common_data.msi_desc = NULL;
109 
110 	desc->irq_data.common = &desc->irq_common_data;
111 	desc->irq_data.irq = irq;
112 	desc->irq_data.chip = &no_irq_chip;
113 	desc->irq_data.chip_data = NULL;
114 	irq_settings_clr_and_set(desc, ~0, _IRQ_DEFAULT_INIT_FLAGS);
115 	irqd_set(&desc->irq_data, IRQD_IRQ_DISABLED);
116 	irqd_set(&desc->irq_data, IRQD_IRQ_MASKED);
117 	desc->handle_irq = handle_bad_irq;
118 	desc->depth = 1;
119 	desc->irq_count = 0;
120 	desc->irqs_unhandled = 0;
121 	desc->tot_count = 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 struct maple_tree sparse_irqs = MTREE_INIT_EXT(sparse_irqs,
134 					MT_FLAGS_ALLOC_RANGE |
135 					MT_FLAGS_LOCK_EXTERN |
136 					MT_FLAGS_USE_RCU,
137 					sparse_irq_lock);
138 
irq_find_free_area(unsigned int from,unsigned int cnt)139 static int irq_find_free_area(unsigned int from, unsigned int cnt)
140 {
141 	MA_STATE(mas, &sparse_irqs, 0, 0);
142 
143 	if (mas_empty_area(&mas, from, MAX_SPARSE_IRQS, cnt))
144 		return -ENOSPC;
145 	return mas.index;
146 }
147 
irq_find_at_or_after(unsigned int offset)148 static unsigned int irq_find_at_or_after(unsigned int offset)
149 {
150 	unsigned long index = offset;
151 	struct irq_desc *desc = mt_find(&sparse_irqs, &index, nr_irqs);
152 
153 	return desc ? irq_desc_get_irq(desc) : nr_irqs;
154 }
155 
irq_insert_desc(unsigned int irq,struct irq_desc * desc)156 static void irq_insert_desc(unsigned int irq, struct irq_desc *desc)
157 {
158 	MA_STATE(mas, &sparse_irqs, irq, irq);
159 	WARN_ON(mas_store_gfp(&mas, desc, GFP_KERNEL) != 0);
160 }
161 
delete_irq_desc(unsigned int irq)162 static void delete_irq_desc(unsigned int irq)
163 {
164 	MA_STATE(mas, &sparse_irqs, irq, irq);
165 	mas_erase(&mas);
166 }
167 
168 #ifdef CONFIG_SPARSE_IRQ
169 
170 static void irq_kobj_release(struct kobject *kobj);
171 
172 #ifdef CONFIG_SYSFS
173 static struct kobject *irq_kobj_base;
174 
175 #define IRQ_ATTR_RO(_name) \
176 static struct kobj_attribute _name##_attr = __ATTR_RO(_name)
177 
per_cpu_count_show(struct kobject * kobj,struct kobj_attribute * attr,char * buf)178 static ssize_t per_cpu_count_show(struct kobject *kobj,
179 				  struct kobj_attribute *attr, char *buf)
180 {
181 	struct irq_desc *desc = container_of(kobj, struct irq_desc, kobj);
182 	ssize_t ret = 0;
183 	char *p = "";
184 	int cpu;
185 
186 	for_each_possible_cpu(cpu) {
187 		unsigned int c = irq_desc_kstat_cpu(desc, cpu);
188 
189 		ret += scnprintf(buf + ret, PAGE_SIZE - ret, "%s%u", p, c);
190 		p = ",";
191 	}
192 
193 	ret += scnprintf(buf + ret, PAGE_SIZE - ret, "\n");
194 	return ret;
195 }
196 IRQ_ATTR_RO(per_cpu_count);
197 
chip_name_show(struct kobject * kobj,struct kobj_attribute * attr,char * buf)198 static ssize_t chip_name_show(struct kobject *kobj,
199 			      struct kobj_attribute *attr, char *buf)
200 {
201 	struct irq_desc *desc = container_of(kobj, struct irq_desc, kobj);
202 	ssize_t ret = 0;
203 
204 	raw_spin_lock_irq(&desc->lock);
205 	if (desc->irq_data.chip && desc->irq_data.chip->name) {
206 		ret = scnprintf(buf, PAGE_SIZE, "%s\n",
207 				desc->irq_data.chip->name);
208 	}
209 	raw_spin_unlock_irq(&desc->lock);
210 
211 	return ret;
212 }
213 IRQ_ATTR_RO(chip_name);
214 
hwirq_show(struct kobject * kobj,struct kobj_attribute * attr,char * buf)215 static ssize_t hwirq_show(struct kobject *kobj,
216 			  struct kobj_attribute *attr, char *buf)
217 {
218 	struct irq_desc *desc = container_of(kobj, struct irq_desc, kobj);
219 	ssize_t ret = 0;
220 
221 	raw_spin_lock_irq(&desc->lock);
222 	if (desc->irq_data.domain)
223 		ret = sprintf(buf, "%lu\n", desc->irq_data.hwirq);
224 	raw_spin_unlock_irq(&desc->lock);
225 
226 	return ret;
227 }
228 IRQ_ATTR_RO(hwirq);
229 
type_show(struct kobject * kobj,struct kobj_attribute * attr,char * buf)230 static ssize_t type_show(struct kobject *kobj,
231 			 struct kobj_attribute *attr, char *buf)
232 {
233 	struct irq_desc *desc = container_of(kobj, struct irq_desc, kobj);
234 	ssize_t ret = 0;
235 
236 	raw_spin_lock_irq(&desc->lock);
237 	ret = sprintf(buf, "%s\n",
238 		      irqd_is_level_type(&desc->irq_data) ? "level" : "edge");
239 	raw_spin_unlock_irq(&desc->lock);
240 
241 	return ret;
242 
243 }
244 IRQ_ATTR_RO(type);
245 
wakeup_show(struct kobject * kobj,struct kobj_attribute * attr,char * buf)246 static ssize_t wakeup_show(struct kobject *kobj,
247 			   struct kobj_attribute *attr, char *buf)
248 {
249 	struct irq_desc *desc = container_of(kobj, struct irq_desc, kobj);
250 	ssize_t ret = 0;
251 
252 	raw_spin_lock_irq(&desc->lock);
253 	ret = sprintf(buf, "%s\n",
254 		      irqd_is_wakeup_set(&desc->irq_data) ? "enabled" : "disabled");
255 	raw_spin_unlock_irq(&desc->lock);
256 
257 	return ret;
258 
259 }
260 IRQ_ATTR_RO(wakeup);
261 
name_show(struct kobject * kobj,struct kobj_attribute * attr,char * buf)262 static ssize_t name_show(struct kobject *kobj,
263 			 struct kobj_attribute *attr, char *buf)
264 {
265 	struct irq_desc *desc = container_of(kobj, struct irq_desc, kobj);
266 	ssize_t ret = 0;
267 
268 	raw_spin_lock_irq(&desc->lock);
269 	if (desc->name)
270 		ret = scnprintf(buf, PAGE_SIZE, "%s\n", desc->name);
271 	raw_spin_unlock_irq(&desc->lock);
272 
273 	return ret;
274 }
275 IRQ_ATTR_RO(name);
276 
actions_show(struct kobject * kobj,struct kobj_attribute * attr,char * buf)277 static ssize_t actions_show(struct kobject *kobj,
278 			    struct kobj_attribute *attr, char *buf)
279 {
280 	struct irq_desc *desc = container_of(kobj, struct irq_desc, kobj);
281 	struct irqaction *action;
282 	ssize_t ret = 0;
283 	char *p = "";
284 
285 	raw_spin_lock_irq(&desc->lock);
286 	for_each_action_of_desc(desc, action) {
287 		ret += scnprintf(buf + ret, PAGE_SIZE - ret, "%s%s",
288 				 p, action->name);
289 		p = ",";
290 	}
291 	raw_spin_unlock_irq(&desc->lock);
292 
293 	if (ret)
294 		ret += scnprintf(buf + ret, PAGE_SIZE - ret, "\n");
295 
296 	return ret;
297 }
298 IRQ_ATTR_RO(actions);
299 
300 static struct attribute *irq_attrs[] = {
301 	&per_cpu_count_attr.attr,
302 	&chip_name_attr.attr,
303 	&hwirq_attr.attr,
304 	&type_attr.attr,
305 	&wakeup_attr.attr,
306 	&name_attr.attr,
307 	&actions_attr.attr,
308 	NULL
309 };
310 ATTRIBUTE_GROUPS(irq);
311 
312 static const struct kobj_type irq_kobj_type = {
313 	.release	= irq_kobj_release,
314 	.sysfs_ops	= &kobj_sysfs_ops,
315 	.default_groups = irq_groups,
316 };
317 
irq_sysfs_add(int irq,struct irq_desc * desc)318 static void irq_sysfs_add(int irq, struct irq_desc *desc)
319 {
320 	if (irq_kobj_base) {
321 		/*
322 		 * Continue even in case of failure as this is nothing
323 		 * crucial and failures in the late irq_sysfs_init()
324 		 * cannot be rolled back.
325 		 */
326 		if (kobject_add(&desc->kobj, irq_kobj_base, "%d", irq))
327 			pr_warn("Failed to add kobject for irq %d\n", irq);
328 		else
329 			desc->istate |= IRQS_SYSFS;
330 	}
331 }
332 
irq_sysfs_del(struct irq_desc * desc)333 static void irq_sysfs_del(struct irq_desc *desc)
334 {
335 	/*
336 	 * Only invoke kobject_del() when kobject_add() was successfully
337 	 * invoked for the descriptor. This covers both early boot, where
338 	 * sysfs is not initialized yet, and the case of a failed
339 	 * kobject_add() invocation.
340 	 */
341 	if (desc->istate & IRQS_SYSFS)
342 		kobject_del(&desc->kobj);
343 }
344 
irq_sysfs_init(void)345 static int __init irq_sysfs_init(void)
346 {
347 	struct irq_desc *desc;
348 	int irq;
349 
350 	/* Prevent concurrent irq alloc/free */
351 	irq_lock_sparse();
352 
353 	irq_kobj_base = kobject_create_and_add("irq", kernel_kobj);
354 	if (!irq_kobj_base) {
355 		irq_unlock_sparse();
356 		return -ENOMEM;
357 	}
358 
359 	/* Add the already allocated interrupts */
360 	for_each_irq_desc(irq, desc)
361 		irq_sysfs_add(irq, desc);
362 	irq_unlock_sparse();
363 
364 	return 0;
365 }
366 postcore_initcall(irq_sysfs_init);
367 
368 #else /* !CONFIG_SYSFS */
369 
370 static const struct kobj_type irq_kobj_type = {
371 	.release	= irq_kobj_release,
372 };
373 
irq_sysfs_add(int irq,struct irq_desc * desc)374 static void irq_sysfs_add(int irq, struct irq_desc *desc) {}
irq_sysfs_del(struct irq_desc * desc)375 static void irq_sysfs_del(struct irq_desc *desc) {}
376 
377 #endif /* CONFIG_SYSFS */
378 
irq_to_desc(unsigned int irq)379 struct irq_desc *irq_to_desc(unsigned int irq)
380 {
381 	return mtree_load(&sparse_irqs, irq);
382 }
383 #ifdef CONFIG_KVM_BOOK3S_64_HV_MODULE
384 EXPORT_SYMBOL_GPL(irq_to_desc);
385 #endif
386 
387 #ifdef CONFIG_SMP
free_masks(struct irq_desc * desc)388 static void free_masks(struct irq_desc *desc)
389 {
390 #ifdef CONFIG_GENERIC_PENDING_IRQ
391 	free_cpumask_var(desc->pending_mask);
392 #endif
393 	free_cpumask_var(desc->irq_common_data.affinity);
394 #ifdef CONFIG_GENERIC_IRQ_EFFECTIVE_AFF_MASK
395 	free_cpumask_var(desc->irq_common_data.effective_affinity);
396 #endif
397 }
398 #else
free_masks(struct irq_desc * desc)399 static inline void free_masks(struct irq_desc *desc) { }
400 #endif
401 
irq_lock_sparse(void)402 void irq_lock_sparse(void)
403 {
404 	mutex_lock(&sparse_irq_lock);
405 }
406 
irq_unlock_sparse(void)407 void irq_unlock_sparse(void)
408 {
409 	mutex_unlock(&sparse_irq_lock);
410 }
411 
alloc_desc(int irq,int node,unsigned int flags,const struct cpumask * affinity,struct module * owner)412 static struct irq_desc *alloc_desc(int irq, int node, unsigned int flags,
413 				   const struct cpumask *affinity,
414 				   struct module *owner)
415 {
416 	struct irq_desc *desc;
417 
418 	desc = kzalloc_node(sizeof(*desc), GFP_KERNEL, node);
419 	if (!desc)
420 		return NULL;
421 	/* allocate based on nr_cpu_ids */
422 	desc->kstat_irqs = alloc_percpu(unsigned int);
423 	if (!desc->kstat_irqs)
424 		goto err_desc;
425 
426 	if (alloc_masks(desc, node))
427 		goto err_kstat;
428 
429 	raw_spin_lock_init(&desc->lock);
430 	lockdep_set_class(&desc->lock, &irq_desc_lock_class);
431 	mutex_init(&desc->request_mutex);
432 	init_rcu_head(&desc->rcu);
433 	init_waitqueue_head(&desc->wait_for_threads);
434 
435 	desc_set_defaults(irq, desc, node, affinity, owner);
436 	irqd_set(&desc->irq_data, flags);
437 	kobject_init(&desc->kobj, &irq_kobj_type);
438 	irq_resend_init(desc);
439 
440 	return desc;
441 
442 err_kstat:
443 	free_percpu(desc->kstat_irqs);
444 err_desc:
445 	kfree(desc);
446 	return NULL;
447 }
448 
irq_kobj_release(struct kobject * kobj)449 static void irq_kobj_release(struct kobject *kobj)
450 {
451 	struct irq_desc *desc = container_of(kobj, struct irq_desc, kobj);
452 
453 	free_masks(desc);
454 	free_percpu(desc->kstat_irqs);
455 	kfree(desc);
456 }
457 
delayed_free_desc(struct rcu_head * rhp)458 static void delayed_free_desc(struct rcu_head *rhp)
459 {
460 	struct irq_desc *desc = container_of(rhp, struct irq_desc, rcu);
461 
462 	kobject_put(&desc->kobj);
463 }
464 
free_desc(unsigned int irq)465 static void free_desc(unsigned int irq)
466 {
467 	struct irq_desc *desc = irq_to_desc(irq);
468 
469 	irq_remove_debugfs_entry(desc);
470 	unregister_irq_proc(irq, desc);
471 
472 	/*
473 	 * sparse_irq_lock protects also show_interrupts() and
474 	 * kstat_irq_usr(). Once we deleted the descriptor from the
475 	 * sparse tree we can free it. Access in proc will fail to
476 	 * lookup the descriptor.
477 	 *
478 	 * The sysfs entry must be serialized against a concurrent
479 	 * irq_sysfs_init() as well.
480 	 */
481 	irq_sysfs_del(desc);
482 	delete_irq_desc(irq);
483 
484 	/*
485 	 * We free the descriptor, masks and stat fields via RCU. That
486 	 * allows demultiplex interrupts to do rcu based management of
487 	 * the child interrupts.
488 	 * This also allows us to use rcu in kstat_irqs_usr().
489 	 */
490 	call_rcu(&desc->rcu, delayed_free_desc);
491 }
492 
alloc_descs(unsigned int start,unsigned int cnt,int node,const struct irq_affinity_desc * affinity,struct module * owner)493 static int alloc_descs(unsigned int start, unsigned int cnt, int node,
494 		       const struct irq_affinity_desc *affinity,
495 		       struct module *owner)
496 {
497 	struct irq_desc *desc;
498 	int i;
499 
500 	/* Validate affinity mask(s) */
501 	if (affinity) {
502 		for (i = 0; i < cnt; i++) {
503 			if (cpumask_empty(&affinity[i].mask))
504 				return -EINVAL;
505 		}
506 	}
507 
508 	for (i = 0; i < cnt; i++) {
509 		const struct cpumask *mask = NULL;
510 		unsigned int flags = 0;
511 
512 		if (affinity) {
513 			if (affinity->is_managed) {
514 				flags = IRQD_AFFINITY_MANAGED |
515 					IRQD_MANAGED_SHUTDOWN;
516 			}
517 			mask = &affinity->mask;
518 			node = cpu_to_node(cpumask_first(mask));
519 			affinity++;
520 		}
521 
522 		desc = alloc_desc(start + i, node, flags, mask, owner);
523 		if (!desc)
524 			goto err;
525 		irq_insert_desc(start + i, desc);
526 		irq_sysfs_add(start + i, desc);
527 		irq_add_debugfs_entry(start + i, desc);
528 	}
529 	return start;
530 
531 err:
532 	for (i--; i >= 0; i--)
533 		free_desc(start + i);
534 	return -ENOMEM;
535 }
536 
irq_expand_nr_irqs(unsigned int nr)537 static int irq_expand_nr_irqs(unsigned int nr)
538 {
539 	if (nr > MAX_SPARSE_IRQS)
540 		return -ENOMEM;
541 	nr_irqs = nr;
542 	return 0;
543 }
544 
early_irq_init(void)545 int __init early_irq_init(void)
546 {
547 	int i, initcnt, node = first_online_node;
548 	struct irq_desc *desc;
549 
550 	init_irq_default_affinity();
551 
552 	/* Let arch update nr_irqs and return the nr of preallocated irqs */
553 	initcnt = arch_probe_nr_irqs();
554 	printk(KERN_INFO "NR_IRQS: %d, nr_irqs: %d, preallocated irqs: %d\n",
555 	       NR_IRQS, nr_irqs, initcnt);
556 
557 	if (WARN_ON(nr_irqs > MAX_SPARSE_IRQS))
558 		nr_irqs = MAX_SPARSE_IRQS;
559 
560 	if (WARN_ON(initcnt > MAX_SPARSE_IRQS))
561 		initcnt = MAX_SPARSE_IRQS;
562 
563 	if (initcnt > nr_irqs)
564 		nr_irqs = initcnt;
565 
566 	for (i = 0; i < initcnt; i++) {
567 		desc = alloc_desc(i, node, 0, NULL, NULL);
568 		irq_insert_desc(i, desc);
569 	}
570 	return arch_early_irq_init();
571 }
572 
573 #else /* !CONFIG_SPARSE_IRQ */
574 
575 struct irq_desc irq_desc[NR_IRQS] __cacheline_aligned_in_smp = {
576 	[0 ... NR_IRQS-1] = {
577 		.handle_irq	= handle_bad_irq,
578 		.depth		= 1,
579 		.lock		= __RAW_SPIN_LOCK_UNLOCKED(irq_desc->lock),
580 	}
581 };
582 
early_irq_init(void)583 int __init early_irq_init(void)
584 {
585 	int count, i, node = first_online_node;
586 	struct irq_desc *desc;
587 
588 	init_irq_default_affinity();
589 
590 	printk(KERN_INFO "NR_IRQS: %d\n", NR_IRQS);
591 
592 	desc = irq_desc;
593 	count = ARRAY_SIZE(irq_desc);
594 
595 	for (i = 0; i < count; i++) {
596 		desc[i].kstat_irqs = alloc_percpu(unsigned int);
597 		alloc_masks(&desc[i], node);
598 		raw_spin_lock_init(&desc[i].lock);
599 		lockdep_set_class(&desc[i].lock, &irq_desc_lock_class);
600 		mutex_init(&desc[i].request_mutex);
601 		init_waitqueue_head(&desc[i].wait_for_threads);
602 		desc_set_defaults(i, &desc[i], node, NULL, NULL);
603 		irq_resend_init(&desc[i]);
604 	}
605 	return arch_early_irq_init();
606 }
607 
irq_to_desc(unsigned int irq)608 struct irq_desc *irq_to_desc(unsigned int irq)
609 {
610 	return (irq < NR_IRQS) ? irq_desc + irq : NULL;
611 }
612 EXPORT_SYMBOL(irq_to_desc);
613 
free_desc(unsigned int irq)614 static void free_desc(unsigned int irq)
615 {
616 	struct irq_desc *desc = irq_to_desc(irq);
617 	unsigned long flags;
618 
619 	raw_spin_lock_irqsave(&desc->lock, flags);
620 	desc_set_defaults(irq, desc, irq_desc_get_node(desc), NULL, NULL);
621 	raw_spin_unlock_irqrestore(&desc->lock, flags);
622 	delete_irq_desc(irq);
623 }
624 
alloc_descs(unsigned int start,unsigned int cnt,int node,const struct irq_affinity_desc * affinity,struct module * owner)625 static inline int alloc_descs(unsigned int start, unsigned int cnt, int node,
626 			      const struct irq_affinity_desc *affinity,
627 			      struct module *owner)
628 {
629 	u32 i;
630 
631 	for (i = 0; i < cnt; i++) {
632 		struct irq_desc *desc = irq_to_desc(start + i);
633 
634 		desc->owner = owner;
635 		irq_insert_desc(start + i, desc);
636 	}
637 	return start;
638 }
639 
irq_expand_nr_irqs(unsigned int nr)640 static int irq_expand_nr_irqs(unsigned int nr)
641 {
642 	return -ENOMEM;
643 }
644 
irq_mark_irq(unsigned int irq)645 void irq_mark_irq(unsigned int irq)
646 {
647 	mutex_lock(&sparse_irq_lock);
648 	irq_insert_desc(irq, irq_desc + irq);
649 	mutex_unlock(&sparse_irq_lock);
650 }
651 
652 #ifdef CONFIG_GENERIC_IRQ_LEGACY
irq_init_desc(unsigned int irq)653 void irq_init_desc(unsigned int irq)
654 {
655 	free_desc(irq);
656 }
657 #endif
658 
659 #endif /* !CONFIG_SPARSE_IRQ */
660 
handle_irq_desc(struct irq_desc * desc)661 int handle_irq_desc(struct irq_desc *desc)
662 {
663 	struct irq_data *data;
664 
665 	if (!desc)
666 		return -EINVAL;
667 
668 	data = irq_desc_get_irq_data(desc);
669 	if (WARN_ON_ONCE(!in_hardirq() && handle_enforce_irqctx(data)))
670 		return -EPERM;
671 
672 	generic_handle_irq_desc(desc);
673 	return 0;
674 }
675 
676 /**
677  * generic_handle_irq - Invoke the handler for a particular irq
678  * @irq:	The irq number to handle
679  *
680  * Returns:	0 on success, or -EINVAL if conversion has failed
681  *
682  * 		This function must be called from an IRQ context with irq regs
683  * 		initialized.
684   */
generic_handle_irq(unsigned int irq)685 int generic_handle_irq(unsigned int irq)
686 {
687 	return handle_irq_desc(irq_to_desc(irq));
688 }
689 EXPORT_SYMBOL_GPL(generic_handle_irq);
690 
691 /**
692  * generic_handle_irq_safe - Invoke the handler for a particular irq from any
693  *			     context.
694  * @irq:	The irq number to handle
695  *
696  * Returns:	0 on success, a negative value on error.
697  *
698  * This function can be called from any context (IRQ or process context). It
699  * will report an error if not invoked from IRQ context and the irq has been
700  * marked to enforce IRQ-context only.
701  */
generic_handle_irq_safe(unsigned int irq)702 int generic_handle_irq_safe(unsigned int irq)
703 {
704 	unsigned long flags;
705 	int ret;
706 
707 	local_irq_save(flags);
708 	ret = handle_irq_desc(irq_to_desc(irq));
709 	local_irq_restore(flags);
710 	return ret;
711 }
712 EXPORT_SYMBOL_GPL(generic_handle_irq_safe);
713 
714 #ifdef CONFIG_IRQ_DOMAIN
715 /**
716  * generic_handle_domain_irq - Invoke the handler for a HW irq belonging
717  *                             to a domain.
718  * @domain:	The domain where to perform the lookup
719  * @hwirq:	The HW irq number to convert to a logical one
720  *
721  * Returns:	0 on success, or -EINVAL if conversion has failed
722  *
723  * 		This function must be called from an IRQ context with irq regs
724  * 		initialized.
725  */
generic_handle_domain_irq(struct irq_domain * domain,unsigned int hwirq)726 int generic_handle_domain_irq(struct irq_domain *domain, unsigned int hwirq)
727 {
728 	return handle_irq_desc(irq_resolve_mapping(domain, hwirq));
729 }
730 EXPORT_SYMBOL_GPL(generic_handle_domain_irq);
731 
732  /**
733  * generic_handle_irq_safe - Invoke the handler for a HW irq belonging
734  *			     to a domain from any context.
735  * @domain:	The domain where to perform the lookup
736  * @hwirq:	The HW irq number to convert to a logical one
737  *
738  * Returns:	0 on success, a negative value on error.
739  *
740  * This function can be called from any context (IRQ or process
741  * context). If the interrupt is marked as 'enforce IRQ-context only' then
742  * the function must be invoked from hard interrupt context.
743  */
generic_handle_domain_irq_safe(struct irq_domain * domain,unsigned int hwirq)744 int generic_handle_domain_irq_safe(struct irq_domain *domain, unsigned int hwirq)
745 {
746 	unsigned long flags;
747 	int ret;
748 
749 	local_irq_save(flags);
750 	ret = handle_irq_desc(irq_resolve_mapping(domain, hwirq));
751 	local_irq_restore(flags);
752 	return ret;
753 }
754 EXPORT_SYMBOL_GPL(generic_handle_domain_irq_safe);
755 
756 /**
757  * generic_handle_domain_nmi - Invoke the handler for a HW nmi belonging
758  *                             to a domain.
759  * @domain:	The domain where to perform the lookup
760  * @hwirq:	The HW irq number to convert to a logical one
761  *
762  * Returns:	0 on success, or -EINVAL if conversion has failed
763  *
764  * 		This function must be called from an NMI context with irq regs
765  * 		initialized.
766  **/
generic_handle_domain_nmi(struct irq_domain * domain,unsigned int hwirq)767 int generic_handle_domain_nmi(struct irq_domain *domain, unsigned int hwirq)
768 {
769 	WARN_ON_ONCE(!in_nmi());
770 	return handle_irq_desc(irq_resolve_mapping(domain, hwirq));
771 }
772 #endif
773 
774 /* Dynamic interrupt handling */
775 
776 /**
777  * irq_free_descs - free irq descriptors
778  * @from:	Start of descriptor range
779  * @cnt:	Number of consecutive irqs to free
780  */
irq_free_descs(unsigned int from,unsigned int cnt)781 void irq_free_descs(unsigned int from, unsigned int cnt)
782 {
783 	int i;
784 
785 	if (from >= nr_irqs || (from + cnt) > nr_irqs)
786 		return;
787 
788 	mutex_lock(&sparse_irq_lock);
789 	for (i = 0; i < cnt; i++)
790 		free_desc(from + i);
791 
792 	mutex_unlock(&sparse_irq_lock);
793 }
794 EXPORT_SYMBOL_GPL(irq_free_descs);
795 
796 /**
797  * __irq_alloc_descs - allocate and initialize a range of irq descriptors
798  * @irq:	Allocate for specific irq number if irq >= 0
799  * @from:	Start the search from this irq number
800  * @cnt:	Number of consecutive irqs to allocate.
801  * @node:	Preferred node on which the irq descriptor should be allocated
802  * @owner:	Owning module (can be NULL)
803  * @affinity:	Optional pointer to an affinity mask array of size @cnt which
804  *		hints where the irq descriptors should be allocated and which
805  *		default affinities to use
806  *
807  * Returns the first irq number or error code
808  */
809 int __ref
__irq_alloc_descs(int irq,unsigned int from,unsigned int cnt,int node,struct module * owner,const struct irq_affinity_desc * affinity)810 __irq_alloc_descs(int irq, unsigned int from, unsigned int cnt, int node,
811 		  struct module *owner, const struct irq_affinity_desc *affinity)
812 {
813 	int start, ret;
814 
815 	if (!cnt)
816 		return -EINVAL;
817 
818 	if (irq >= 0) {
819 		if (from > irq)
820 			return -EINVAL;
821 		from = irq;
822 	} else {
823 		/*
824 		 * For interrupts which are freely allocated the
825 		 * architecture can force a lower bound to the @from
826 		 * argument. x86 uses this to exclude the GSI space.
827 		 */
828 		from = arch_dynirq_lower_bound(from);
829 	}
830 
831 	mutex_lock(&sparse_irq_lock);
832 
833 	start = irq_find_free_area(from, cnt);
834 	ret = -EEXIST;
835 	if (irq >=0 && start != irq)
836 		goto unlock;
837 
838 	if (start + cnt > nr_irqs) {
839 		ret = irq_expand_nr_irqs(start + cnt);
840 		if (ret)
841 			goto unlock;
842 	}
843 	ret = alloc_descs(start, cnt, node, affinity, owner);
844 unlock:
845 	mutex_unlock(&sparse_irq_lock);
846 	return ret;
847 }
848 EXPORT_SYMBOL_GPL(__irq_alloc_descs);
849 
850 /**
851  * irq_get_next_irq - get next allocated irq number
852  * @offset:	where to start the search
853  *
854  * Returns next irq number after offset or nr_irqs if none is found.
855  */
irq_get_next_irq(unsigned int offset)856 unsigned int irq_get_next_irq(unsigned int offset)
857 {
858 	return irq_find_at_or_after(offset);
859 }
860 
861 struct irq_desc *
__irq_get_desc_lock(unsigned int irq,unsigned long * flags,bool bus,unsigned int check)862 __irq_get_desc_lock(unsigned int irq, unsigned long *flags, bool bus,
863 		    unsigned int check)
864 {
865 	struct irq_desc *desc = irq_to_desc(irq);
866 
867 	if (desc) {
868 		if (check & _IRQ_DESC_CHECK) {
869 			if ((check & _IRQ_DESC_PERCPU) &&
870 			    !irq_settings_is_per_cpu_devid(desc))
871 				return NULL;
872 
873 			if (!(check & _IRQ_DESC_PERCPU) &&
874 			    irq_settings_is_per_cpu_devid(desc))
875 				return NULL;
876 		}
877 
878 		if (bus)
879 			chip_bus_lock(desc);
880 		raw_spin_lock_irqsave(&desc->lock, *flags);
881 	}
882 	return desc;
883 }
884 
__irq_put_desc_unlock(struct irq_desc * desc,unsigned long flags,bool bus)885 void __irq_put_desc_unlock(struct irq_desc *desc, unsigned long flags, bool bus)
886 	__releases(&desc->lock)
887 {
888 	raw_spin_unlock_irqrestore(&desc->lock, flags);
889 	if (bus)
890 		chip_bus_sync_unlock(desc);
891 }
892 
irq_set_percpu_devid_partition(unsigned int irq,const struct cpumask * affinity)893 int irq_set_percpu_devid_partition(unsigned int irq,
894 				   const struct cpumask *affinity)
895 {
896 	struct irq_desc *desc = irq_to_desc(irq);
897 
898 	if (!desc)
899 		return -EINVAL;
900 
901 	if (desc->percpu_enabled)
902 		return -EINVAL;
903 
904 	desc->percpu_enabled = kzalloc(sizeof(*desc->percpu_enabled), GFP_KERNEL);
905 
906 	if (!desc->percpu_enabled)
907 		return -ENOMEM;
908 
909 	if (affinity)
910 		desc->percpu_affinity = affinity;
911 	else
912 		desc->percpu_affinity = cpu_possible_mask;
913 
914 	irq_set_percpu_devid_flags(irq);
915 	return 0;
916 }
917 
irq_set_percpu_devid(unsigned int irq)918 int irq_set_percpu_devid(unsigned int irq)
919 {
920 	return irq_set_percpu_devid_partition(irq, NULL);
921 }
922 
irq_get_percpu_devid_partition(unsigned int irq,struct cpumask * affinity)923 int irq_get_percpu_devid_partition(unsigned int irq, struct cpumask *affinity)
924 {
925 	struct irq_desc *desc = irq_to_desc(irq);
926 
927 	if (!desc || !desc->percpu_enabled)
928 		return -EINVAL;
929 
930 	if (affinity)
931 		cpumask_copy(affinity, desc->percpu_affinity);
932 
933 	return 0;
934 }
935 EXPORT_SYMBOL_GPL(irq_get_percpu_devid_partition);
936 
kstat_incr_irq_this_cpu(unsigned int irq)937 void kstat_incr_irq_this_cpu(unsigned int irq)
938 {
939 	kstat_incr_irqs_this_cpu(irq_to_desc(irq));
940 }
941 
942 /**
943  * kstat_irqs_cpu - Get the statistics for an interrupt on a cpu
944  * @irq:	The interrupt number
945  * @cpu:	The cpu number
946  *
947  * Returns the sum of interrupt counts on @cpu since boot for
948  * @irq. The caller must ensure that the interrupt is not removed
949  * concurrently.
950  */
kstat_irqs_cpu(unsigned int irq,int cpu)951 unsigned int kstat_irqs_cpu(unsigned int irq, int cpu)
952 {
953 	struct irq_desc *desc = irq_to_desc(irq);
954 
955 	return desc && desc->kstat_irqs ?
956 			*per_cpu_ptr(desc->kstat_irqs, cpu) : 0;
957 }
958 
irq_is_nmi(struct irq_desc * desc)959 static bool irq_is_nmi(struct irq_desc *desc)
960 {
961 	return desc->istate & IRQS_NMI;
962 }
963 
kstat_irqs(unsigned int irq)964 static unsigned int kstat_irqs(unsigned int irq)
965 {
966 	struct irq_desc *desc = irq_to_desc(irq);
967 	unsigned int sum = 0;
968 	int cpu;
969 
970 	if (!desc || !desc->kstat_irqs)
971 		return 0;
972 	if (!irq_settings_is_per_cpu_devid(desc) &&
973 	    !irq_settings_is_per_cpu(desc) &&
974 	    !irq_is_nmi(desc))
975 		return data_race(desc->tot_count);
976 
977 	for_each_possible_cpu(cpu)
978 		sum += data_race(*per_cpu_ptr(desc->kstat_irqs, cpu));
979 	return sum;
980 }
981 
982 /**
983  * kstat_irqs_usr - Get the statistics for an interrupt from thread context
984  * @irq:	The interrupt number
985  *
986  * Returns the sum of interrupt counts on all cpus since boot for @irq.
987  *
988  * It uses rcu to protect the access since a concurrent removal of an
989  * interrupt descriptor is observing an rcu grace period before
990  * delayed_free_desc()/irq_kobj_release().
991  */
kstat_irqs_usr(unsigned int irq)992 unsigned int kstat_irqs_usr(unsigned int irq)
993 {
994 	unsigned int sum;
995 
996 	rcu_read_lock();
997 	sum = kstat_irqs(irq);
998 	rcu_read_unlock();
999 	return sum;
1000 }
1001 
1002 #ifdef CONFIG_LOCKDEP
__irq_set_lockdep_class(unsigned int irq,struct lock_class_key * lock_class,struct lock_class_key * request_class)1003 void __irq_set_lockdep_class(unsigned int irq, struct lock_class_key *lock_class,
1004 			     struct lock_class_key *request_class)
1005 {
1006 	struct irq_desc *desc = irq_to_desc(irq);
1007 
1008 	if (desc) {
1009 		lockdep_set_class(&desc->lock, lock_class);
1010 		lockdep_set_class(&desc->request_mutex, request_class);
1011 	}
1012 }
1013 EXPORT_SYMBOL_GPL(__irq_set_lockdep_class);
1014 #endif
1015