xref: /openbmc/linux/kernel/irq/irqdesc.c (revision 0688cacd)
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;
152 
153 	guard(rcu)();
154 	desc = mt_find(&sparse_irqs, &index, nr_irqs);
155 
156 	return desc ? irq_desc_get_irq(desc) : nr_irqs;
157 }
158 
irq_insert_desc(unsigned int irq,struct irq_desc * desc)159 static void irq_insert_desc(unsigned int irq, struct irq_desc *desc)
160 {
161 	MA_STATE(mas, &sparse_irqs, irq, irq);
162 	WARN_ON(mas_store_gfp(&mas, desc, GFP_KERNEL) != 0);
163 }
164 
delete_irq_desc(unsigned int irq)165 static void delete_irq_desc(unsigned int irq)
166 {
167 	MA_STATE(mas, &sparse_irqs, irq, irq);
168 	mas_erase(&mas);
169 }
170 
171 #ifdef CONFIG_SPARSE_IRQ
172 
173 static void irq_kobj_release(struct kobject *kobj);
174 
175 #ifdef CONFIG_SYSFS
176 static struct kobject *irq_kobj_base;
177 
178 #define IRQ_ATTR_RO(_name) \
179 static struct kobj_attribute _name##_attr = __ATTR_RO(_name)
180 
per_cpu_count_show(struct kobject * kobj,struct kobj_attribute * attr,char * buf)181 static ssize_t per_cpu_count_show(struct kobject *kobj,
182 				  struct kobj_attribute *attr, char *buf)
183 {
184 	struct irq_desc *desc = container_of(kobj, struct irq_desc, kobj);
185 	ssize_t ret = 0;
186 	char *p = "";
187 	int cpu;
188 
189 	for_each_possible_cpu(cpu) {
190 		unsigned int c = irq_desc_kstat_cpu(desc, cpu);
191 
192 		ret += scnprintf(buf + ret, PAGE_SIZE - ret, "%s%u", p, c);
193 		p = ",";
194 	}
195 
196 	ret += scnprintf(buf + ret, PAGE_SIZE - ret, "\n");
197 	return ret;
198 }
199 IRQ_ATTR_RO(per_cpu_count);
200 
chip_name_show(struct kobject * kobj,struct kobj_attribute * attr,char * buf)201 static ssize_t chip_name_show(struct kobject *kobj,
202 			      struct kobj_attribute *attr, char *buf)
203 {
204 	struct irq_desc *desc = container_of(kobj, struct irq_desc, kobj);
205 	ssize_t ret = 0;
206 
207 	raw_spin_lock_irq(&desc->lock);
208 	if (desc->irq_data.chip && desc->irq_data.chip->name) {
209 		ret = scnprintf(buf, PAGE_SIZE, "%s\n",
210 				desc->irq_data.chip->name);
211 	}
212 	raw_spin_unlock_irq(&desc->lock);
213 
214 	return ret;
215 }
216 IRQ_ATTR_RO(chip_name);
217 
hwirq_show(struct kobject * kobj,struct kobj_attribute * attr,char * buf)218 static ssize_t hwirq_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 	ssize_t ret = 0;
223 
224 	raw_spin_lock_irq(&desc->lock);
225 	if (desc->irq_data.domain)
226 		ret = sprintf(buf, "%lu\n", desc->irq_data.hwirq);
227 	raw_spin_unlock_irq(&desc->lock);
228 
229 	return ret;
230 }
231 IRQ_ATTR_RO(hwirq);
232 
type_show(struct kobject * kobj,struct kobj_attribute * attr,char * buf)233 static ssize_t type_show(struct kobject *kobj,
234 			 struct kobj_attribute *attr, char *buf)
235 {
236 	struct irq_desc *desc = container_of(kobj, struct irq_desc, kobj);
237 	ssize_t ret = 0;
238 
239 	raw_spin_lock_irq(&desc->lock);
240 	ret = sprintf(buf, "%s\n",
241 		      irqd_is_level_type(&desc->irq_data) ? "level" : "edge");
242 	raw_spin_unlock_irq(&desc->lock);
243 
244 	return ret;
245 
246 }
247 IRQ_ATTR_RO(type);
248 
wakeup_show(struct kobject * kobj,struct kobj_attribute * attr,char * buf)249 static ssize_t wakeup_show(struct kobject *kobj,
250 			   struct kobj_attribute *attr, char *buf)
251 {
252 	struct irq_desc *desc = container_of(kobj, struct irq_desc, kobj);
253 	ssize_t ret = 0;
254 
255 	raw_spin_lock_irq(&desc->lock);
256 	ret = sprintf(buf, "%s\n",
257 		      irqd_is_wakeup_set(&desc->irq_data) ? "enabled" : "disabled");
258 	raw_spin_unlock_irq(&desc->lock);
259 
260 	return ret;
261 
262 }
263 IRQ_ATTR_RO(wakeup);
264 
name_show(struct kobject * kobj,struct kobj_attribute * attr,char * buf)265 static ssize_t name_show(struct kobject *kobj,
266 			 struct kobj_attribute *attr, char *buf)
267 {
268 	struct irq_desc *desc = container_of(kobj, struct irq_desc, kobj);
269 	ssize_t ret = 0;
270 
271 	raw_spin_lock_irq(&desc->lock);
272 	if (desc->name)
273 		ret = scnprintf(buf, PAGE_SIZE, "%s\n", desc->name);
274 	raw_spin_unlock_irq(&desc->lock);
275 
276 	return ret;
277 }
278 IRQ_ATTR_RO(name);
279 
actions_show(struct kobject * kobj,struct kobj_attribute * attr,char * buf)280 static ssize_t actions_show(struct kobject *kobj,
281 			    struct kobj_attribute *attr, char *buf)
282 {
283 	struct irq_desc *desc = container_of(kobj, struct irq_desc, kobj);
284 	struct irqaction *action;
285 	ssize_t ret = 0;
286 	char *p = "";
287 
288 	raw_spin_lock_irq(&desc->lock);
289 	for_each_action_of_desc(desc, action) {
290 		ret += scnprintf(buf + ret, PAGE_SIZE - ret, "%s%s",
291 				 p, action->name);
292 		p = ",";
293 	}
294 	raw_spin_unlock_irq(&desc->lock);
295 
296 	if (ret)
297 		ret += scnprintf(buf + ret, PAGE_SIZE - ret, "\n");
298 
299 	return ret;
300 }
301 IRQ_ATTR_RO(actions);
302 
303 static struct attribute *irq_attrs[] = {
304 	&per_cpu_count_attr.attr,
305 	&chip_name_attr.attr,
306 	&hwirq_attr.attr,
307 	&type_attr.attr,
308 	&wakeup_attr.attr,
309 	&name_attr.attr,
310 	&actions_attr.attr,
311 	NULL
312 };
313 ATTRIBUTE_GROUPS(irq);
314 
315 static const struct kobj_type irq_kobj_type = {
316 	.release	= irq_kobj_release,
317 	.sysfs_ops	= &kobj_sysfs_ops,
318 	.default_groups = irq_groups,
319 };
320 
irq_sysfs_add(int irq,struct irq_desc * desc)321 static void irq_sysfs_add(int irq, struct irq_desc *desc)
322 {
323 	if (irq_kobj_base) {
324 		/*
325 		 * Continue even in case of failure as this is nothing
326 		 * crucial and failures in the late irq_sysfs_init()
327 		 * cannot be rolled back.
328 		 */
329 		if (kobject_add(&desc->kobj, irq_kobj_base, "%d", irq))
330 			pr_warn("Failed to add kobject for irq %d\n", irq);
331 		else
332 			desc->istate |= IRQS_SYSFS;
333 	}
334 }
335 
irq_sysfs_del(struct irq_desc * desc)336 static void irq_sysfs_del(struct irq_desc *desc)
337 {
338 	/*
339 	 * Only invoke kobject_del() when kobject_add() was successfully
340 	 * invoked for the descriptor. This covers both early boot, where
341 	 * sysfs is not initialized yet, and the case of a failed
342 	 * kobject_add() invocation.
343 	 */
344 	if (desc->istate & IRQS_SYSFS)
345 		kobject_del(&desc->kobj);
346 }
347 
irq_sysfs_init(void)348 static int __init irq_sysfs_init(void)
349 {
350 	struct irq_desc *desc;
351 	int irq;
352 
353 	/* Prevent concurrent irq alloc/free */
354 	irq_lock_sparse();
355 
356 	irq_kobj_base = kobject_create_and_add("irq", kernel_kobj);
357 	if (!irq_kobj_base) {
358 		irq_unlock_sparse();
359 		return -ENOMEM;
360 	}
361 
362 	/* Add the already allocated interrupts */
363 	for_each_irq_desc(irq, desc)
364 		irq_sysfs_add(irq, desc);
365 	irq_unlock_sparse();
366 
367 	return 0;
368 }
369 postcore_initcall(irq_sysfs_init);
370 
371 #else /* !CONFIG_SYSFS */
372 
373 static const struct kobj_type irq_kobj_type = {
374 	.release	= irq_kobj_release,
375 };
376 
irq_sysfs_add(int irq,struct irq_desc * desc)377 static void irq_sysfs_add(int irq, struct irq_desc *desc) {}
irq_sysfs_del(struct irq_desc * desc)378 static void irq_sysfs_del(struct irq_desc *desc) {}
379 
380 #endif /* CONFIG_SYSFS */
381 
irq_to_desc(unsigned int irq)382 struct irq_desc *irq_to_desc(unsigned int irq)
383 {
384 	return mtree_load(&sparse_irqs, irq);
385 }
386 #ifdef CONFIG_KVM_BOOK3S_64_HV_MODULE
387 EXPORT_SYMBOL_GPL(irq_to_desc);
388 #endif
389 
390 #ifdef CONFIG_SMP
free_masks(struct irq_desc * desc)391 static void free_masks(struct irq_desc *desc)
392 {
393 #ifdef CONFIG_GENERIC_PENDING_IRQ
394 	free_cpumask_var(desc->pending_mask);
395 #endif
396 	free_cpumask_var(desc->irq_common_data.affinity);
397 #ifdef CONFIG_GENERIC_IRQ_EFFECTIVE_AFF_MASK
398 	free_cpumask_var(desc->irq_common_data.effective_affinity);
399 #endif
400 }
401 #else
free_masks(struct irq_desc * desc)402 static inline void free_masks(struct irq_desc *desc) { }
403 #endif
404 
irq_lock_sparse(void)405 void irq_lock_sparse(void)
406 {
407 	mutex_lock(&sparse_irq_lock);
408 }
409 
irq_unlock_sparse(void)410 void irq_unlock_sparse(void)
411 {
412 	mutex_unlock(&sparse_irq_lock);
413 }
414 
alloc_desc(int irq,int node,unsigned int flags,const struct cpumask * affinity,struct module * owner)415 static struct irq_desc *alloc_desc(int irq, int node, unsigned int flags,
416 				   const struct cpumask *affinity,
417 				   struct module *owner)
418 {
419 	struct irq_desc *desc;
420 
421 	desc = kzalloc_node(sizeof(*desc), GFP_KERNEL, node);
422 	if (!desc)
423 		return NULL;
424 	/* allocate based on nr_cpu_ids */
425 	desc->kstat_irqs = alloc_percpu(unsigned int);
426 	if (!desc->kstat_irqs)
427 		goto err_desc;
428 
429 	if (alloc_masks(desc, node))
430 		goto err_kstat;
431 
432 	raw_spin_lock_init(&desc->lock);
433 	lockdep_set_class(&desc->lock, &irq_desc_lock_class);
434 	mutex_init(&desc->request_mutex);
435 	init_rcu_head(&desc->rcu);
436 	init_waitqueue_head(&desc->wait_for_threads);
437 
438 	desc_set_defaults(irq, desc, node, affinity, owner);
439 	irqd_set(&desc->irq_data, flags);
440 	kobject_init(&desc->kobj, &irq_kobj_type);
441 	irq_resend_init(desc);
442 
443 	return desc;
444 
445 err_kstat:
446 	free_percpu(desc->kstat_irqs);
447 err_desc:
448 	kfree(desc);
449 	return NULL;
450 }
451 
irq_kobj_release(struct kobject * kobj)452 static void irq_kobj_release(struct kobject *kobj)
453 {
454 	struct irq_desc *desc = container_of(kobj, struct irq_desc, kobj);
455 
456 	free_masks(desc);
457 	free_percpu(desc->kstat_irqs);
458 	kfree(desc);
459 }
460 
delayed_free_desc(struct rcu_head * rhp)461 static void delayed_free_desc(struct rcu_head *rhp)
462 {
463 	struct irq_desc *desc = container_of(rhp, struct irq_desc, rcu);
464 
465 	kobject_put(&desc->kobj);
466 }
467 
free_desc(unsigned int irq)468 static void free_desc(unsigned int irq)
469 {
470 	struct irq_desc *desc = irq_to_desc(irq);
471 
472 	irq_remove_debugfs_entry(desc);
473 	unregister_irq_proc(irq, desc);
474 
475 	/*
476 	 * sparse_irq_lock protects also show_interrupts() and
477 	 * kstat_irq_usr(). Once we deleted the descriptor from the
478 	 * sparse tree we can free it. Access in proc will fail to
479 	 * lookup the descriptor.
480 	 *
481 	 * The sysfs entry must be serialized against a concurrent
482 	 * irq_sysfs_init() as well.
483 	 */
484 	irq_sysfs_del(desc);
485 	delete_irq_desc(irq);
486 
487 	/*
488 	 * We free the descriptor, masks and stat fields via RCU. That
489 	 * allows demultiplex interrupts to do rcu based management of
490 	 * the child interrupts.
491 	 * This also allows us to use rcu in kstat_irqs_usr().
492 	 */
493 	call_rcu(&desc->rcu, delayed_free_desc);
494 }
495 
alloc_descs(unsigned int start,unsigned int cnt,int node,const struct irq_affinity_desc * affinity,struct module * owner)496 static int alloc_descs(unsigned int start, unsigned int cnt, int node,
497 		       const struct irq_affinity_desc *affinity,
498 		       struct module *owner)
499 {
500 	struct irq_desc *desc;
501 	int i;
502 
503 	/* Validate affinity mask(s) */
504 	if (affinity) {
505 		for (i = 0; i < cnt; i++) {
506 			if (cpumask_empty(&affinity[i].mask))
507 				return -EINVAL;
508 		}
509 	}
510 
511 	for (i = 0; i < cnt; i++) {
512 		const struct cpumask *mask = NULL;
513 		unsigned int flags = 0;
514 
515 		if (affinity) {
516 			if (affinity->is_managed) {
517 				flags = IRQD_AFFINITY_MANAGED |
518 					IRQD_MANAGED_SHUTDOWN;
519 			}
520 			flags |= IRQD_AFFINITY_SET;
521 			mask = &affinity->mask;
522 			node = cpu_to_node(cpumask_first(mask));
523 			affinity++;
524 		}
525 
526 		desc = alloc_desc(start + i, node, flags, mask, owner);
527 		if (!desc)
528 			goto err;
529 		irq_insert_desc(start + i, desc);
530 		irq_sysfs_add(start + i, desc);
531 		irq_add_debugfs_entry(start + i, desc);
532 	}
533 	return start;
534 
535 err:
536 	for (i--; i >= 0; i--)
537 		free_desc(start + i);
538 	return -ENOMEM;
539 }
540 
irq_expand_nr_irqs(unsigned int nr)541 static int irq_expand_nr_irqs(unsigned int nr)
542 {
543 	if (nr > MAX_SPARSE_IRQS)
544 		return -ENOMEM;
545 	nr_irqs = nr;
546 	return 0;
547 }
548 
early_irq_init(void)549 int __init early_irq_init(void)
550 {
551 	int i, initcnt, node = first_online_node;
552 	struct irq_desc *desc;
553 
554 	init_irq_default_affinity();
555 
556 	/* Let arch update nr_irqs and return the nr of preallocated irqs */
557 	initcnt = arch_probe_nr_irqs();
558 	printk(KERN_INFO "NR_IRQS: %d, nr_irqs: %d, preallocated irqs: %d\n",
559 	       NR_IRQS, nr_irqs, initcnt);
560 
561 	if (WARN_ON(nr_irqs > MAX_SPARSE_IRQS))
562 		nr_irqs = MAX_SPARSE_IRQS;
563 
564 	if (WARN_ON(initcnt > MAX_SPARSE_IRQS))
565 		initcnt = MAX_SPARSE_IRQS;
566 
567 	if (initcnt > nr_irqs)
568 		nr_irqs = initcnt;
569 
570 	for (i = 0; i < initcnt; i++) {
571 		desc = alloc_desc(i, node, 0, NULL, NULL);
572 		irq_insert_desc(i, desc);
573 	}
574 	return arch_early_irq_init();
575 }
576 
577 #else /* !CONFIG_SPARSE_IRQ */
578 
579 struct irq_desc irq_desc[NR_IRQS] __cacheline_aligned_in_smp = {
580 	[0 ... NR_IRQS-1] = {
581 		.handle_irq	= handle_bad_irq,
582 		.depth		= 1,
583 		.lock		= __RAW_SPIN_LOCK_UNLOCKED(irq_desc->lock),
584 	}
585 };
586 
early_irq_init(void)587 int __init early_irq_init(void)
588 {
589 	int count, i, node = first_online_node;
590 	struct irq_desc *desc;
591 
592 	init_irq_default_affinity();
593 
594 	printk(KERN_INFO "NR_IRQS: %d\n", NR_IRQS);
595 
596 	desc = irq_desc;
597 	count = ARRAY_SIZE(irq_desc);
598 
599 	for (i = 0; i < count; i++) {
600 		desc[i].kstat_irqs = alloc_percpu(unsigned int);
601 		alloc_masks(&desc[i], node);
602 		raw_spin_lock_init(&desc[i].lock);
603 		lockdep_set_class(&desc[i].lock, &irq_desc_lock_class);
604 		mutex_init(&desc[i].request_mutex);
605 		init_waitqueue_head(&desc[i].wait_for_threads);
606 		desc_set_defaults(i, &desc[i], node, NULL, NULL);
607 		irq_resend_init(&desc[i]);
608 	}
609 	return arch_early_irq_init();
610 }
611 
irq_to_desc(unsigned int irq)612 struct irq_desc *irq_to_desc(unsigned int irq)
613 {
614 	return (irq < NR_IRQS) ? irq_desc + irq : NULL;
615 }
616 EXPORT_SYMBOL(irq_to_desc);
617 
free_desc(unsigned int irq)618 static void free_desc(unsigned int irq)
619 {
620 	struct irq_desc *desc = irq_to_desc(irq);
621 	unsigned long flags;
622 
623 	raw_spin_lock_irqsave(&desc->lock, flags);
624 	desc_set_defaults(irq, desc, irq_desc_get_node(desc), NULL, NULL);
625 	raw_spin_unlock_irqrestore(&desc->lock, flags);
626 	delete_irq_desc(irq);
627 }
628 
alloc_descs(unsigned int start,unsigned int cnt,int node,const struct irq_affinity_desc * affinity,struct module * owner)629 static inline int alloc_descs(unsigned int start, unsigned int cnt, int node,
630 			      const struct irq_affinity_desc *affinity,
631 			      struct module *owner)
632 {
633 	u32 i;
634 
635 	for (i = 0; i < cnt; i++) {
636 		struct irq_desc *desc = irq_to_desc(start + i);
637 
638 		desc->owner = owner;
639 		irq_insert_desc(start + i, desc);
640 	}
641 	return start;
642 }
643 
irq_expand_nr_irqs(unsigned int nr)644 static int irq_expand_nr_irqs(unsigned int nr)
645 {
646 	return -ENOMEM;
647 }
648 
irq_mark_irq(unsigned int irq)649 void irq_mark_irq(unsigned int irq)
650 {
651 	mutex_lock(&sparse_irq_lock);
652 	irq_insert_desc(irq, irq_desc + irq);
653 	mutex_unlock(&sparse_irq_lock);
654 }
655 
656 #ifdef CONFIG_GENERIC_IRQ_LEGACY
irq_init_desc(unsigned int irq)657 void irq_init_desc(unsigned int irq)
658 {
659 	free_desc(irq);
660 }
661 #endif
662 
663 #endif /* !CONFIG_SPARSE_IRQ */
664 
handle_irq_desc(struct irq_desc * desc)665 int handle_irq_desc(struct irq_desc *desc)
666 {
667 	struct irq_data *data;
668 
669 	if (!desc)
670 		return -EINVAL;
671 
672 	data = irq_desc_get_irq_data(desc);
673 	if (WARN_ON_ONCE(!in_hardirq() && handle_enforce_irqctx(data)))
674 		return -EPERM;
675 
676 	generic_handle_irq_desc(desc);
677 	return 0;
678 }
679 
680 /**
681  * generic_handle_irq - Invoke the handler for a particular irq
682  * @irq:	The irq number to handle
683  *
684  * Returns:	0 on success, or -EINVAL if conversion has failed
685  *
686  * 		This function must be called from an IRQ context with irq regs
687  * 		initialized.
688   */
generic_handle_irq(unsigned int irq)689 int generic_handle_irq(unsigned int irq)
690 {
691 	return handle_irq_desc(irq_to_desc(irq));
692 }
693 EXPORT_SYMBOL_GPL(generic_handle_irq);
694 
695 /**
696  * generic_handle_irq_safe - Invoke the handler for a particular irq from any
697  *			     context.
698  * @irq:	The irq number to handle
699  *
700  * Returns:	0 on success, a negative value on error.
701  *
702  * This function can be called from any context (IRQ or process context). It
703  * will report an error if not invoked from IRQ context and the irq has been
704  * marked to enforce IRQ-context only.
705  */
generic_handle_irq_safe(unsigned int irq)706 int generic_handle_irq_safe(unsigned int irq)
707 {
708 	unsigned long flags;
709 	int ret;
710 
711 	local_irq_save(flags);
712 	ret = handle_irq_desc(irq_to_desc(irq));
713 	local_irq_restore(flags);
714 	return ret;
715 }
716 EXPORT_SYMBOL_GPL(generic_handle_irq_safe);
717 
718 #ifdef CONFIG_IRQ_DOMAIN
719 /**
720  * generic_handle_domain_irq - Invoke the handler for a HW irq belonging
721  *                             to a domain.
722  * @domain:	The domain where to perform the lookup
723  * @hwirq:	The HW irq number to convert to a logical one
724  *
725  * Returns:	0 on success, or -EINVAL if conversion has failed
726  *
727  * 		This function must be called from an IRQ context with irq regs
728  * 		initialized.
729  */
generic_handle_domain_irq(struct irq_domain * domain,unsigned int hwirq)730 int generic_handle_domain_irq(struct irq_domain *domain, unsigned int hwirq)
731 {
732 	return handle_irq_desc(irq_resolve_mapping(domain, hwirq));
733 }
734 EXPORT_SYMBOL_GPL(generic_handle_domain_irq);
735 
736  /**
737  * generic_handle_irq_safe - Invoke the handler for a HW irq belonging
738  *			     to a domain from any context.
739  * @domain:	The domain where to perform the lookup
740  * @hwirq:	The HW irq number to convert to a logical one
741  *
742  * Returns:	0 on success, a negative value on error.
743  *
744  * This function can be called from any context (IRQ or process
745  * context). If the interrupt is marked as 'enforce IRQ-context only' then
746  * the function must be invoked from hard interrupt context.
747  */
generic_handle_domain_irq_safe(struct irq_domain * domain,unsigned int hwirq)748 int generic_handle_domain_irq_safe(struct irq_domain *domain, unsigned int hwirq)
749 {
750 	unsigned long flags;
751 	int ret;
752 
753 	local_irq_save(flags);
754 	ret = handle_irq_desc(irq_resolve_mapping(domain, hwirq));
755 	local_irq_restore(flags);
756 	return ret;
757 }
758 EXPORT_SYMBOL_GPL(generic_handle_domain_irq_safe);
759 
760 /**
761  * generic_handle_domain_nmi - Invoke the handler for a HW nmi belonging
762  *                             to a domain.
763  * @domain:	The domain where to perform the lookup
764  * @hwirq:	The HW irq number to convert to a logical one
765  *
766  * Returns:	0 on success, or -EINVAL if conversion has failed
767  *
768  * 		This function must be called from an NMI context with irq regs
769  * 		initialized.
770  **/
generic_handle_domain_nmi(struct irq_domain * domain,unsigned int hwirq)771 int generic_handle_domain_nmi(struct irq_domain *domain, unsigned int hwirq)
772 {
773 	WARN_ON_ONCE(!in_nmi());
774 	return handle_irq_desc(irq_resolve_mapping(domain, hwirq));
775 }
776 #endif
777 
778 /* Dynamic interrupt handling */
779 
780 /**
781  * irq_free_descs - free irq descriptors
782  * @from:	Start of descriptor range
783  * @cnt:	Number of consecutive irqs to free
784  */
irq_free_descs(unsigned int from,unsigned int cnt)785 void irq_free_descs(unsigned int from, unsigned int cnt)
786 {
787 	int i;
788 
789 	if (from >= nr_irqs || (from + cnt) > nr_irqs)
790 		return;
791 
792 	mutex_lock(&sparse_irq_lock);
793 	for (i = 0; i < cnt; i++)
794 		free_desc(from + i);
795 
796 	mutex_unlock(&sparse_irq_lock);
797 }
798 EXPORT_SYMBOL_GPL(irq_free_descs);
799 
800 /**
801  * __irq_alloc_descs - allocate and initialize a range of irq descriptors
802  * @irq:	Allocate for specific irq number if irq >= 0
803  * @from:	Start the search from this irq number
804  * @cnt:	Number of consecutive irqs to allocate.
805  * @node:	Preferred node on which the irq descriptor should be allocated
806  * @owner:	Owning module (can be NULL)
807  * @affinity:	Optional pointer to an affinity mask array of size @cnt which
808  *		hints where the irq descriptors should be allocated and which
809  *		default affinities to use
810  *
811  * Returns the first irq number or error code
812  */
813 int __ref
__irq_alloc_descs(int irq,unsigned int from,unsigned int cnt,int node,struct module * owner,const struct irq_affinity_desc * affinity)814 __irq_alloc_descs(int irq, unsigned int from, unsigned int cnt, int node,
815 		  struct module *owner, const struct irq_affinity_desc *affinity)
816 {
817 	int start, ret;
818 
819 	if (!cnt)
820 		return -EINVAL;
821 
822 	if (irq >= 0) {
823 		if (from > irq)
824 			return -EINVAL;
825 		from = irq;
826 	} else {
827 		/*
828 		 * For interrupts which are freely allocated the
829 		 * architecture can force a lower bound to the @from
830 		 * argument. x86 uses this to exclude the GSI space.
831 		 */
832 		from = arch_dynirq_lower_bound(from);
833 	}
834 
835 	mutex_lock(&sparse_irq_lock);
836 
837 	start = irq_find_free_area(from, cnt);
838 	ret = -EEXIST;
839 	if (irq >=0 && start != irq)
840 		goto unlock;
841 
842 	if (start + cnt > nr_irqs) {
843 		ret = irq_expand_nr_irqs(start + cnt);
844 		if (ret)
845 			goto unlock;
846 	}
847 	ret = alloc_descs(start, cnt, node, affinity, owner);
848 unlock:
849 	mutex_unlock(&sparse_irq_lock);
850 	return ret;
851 }
852 EXPORT_SYMBOL_GPL(__irq_alloc_descs);
853 
854 /**
855  * irq_get_next_irq - get next allocated irq number
856  * @offset:	where to start the search
857  *
858  * Returns next irq number after offset or nr_irqs if none is found.
859  */
irq_get_next_irq(unsigned int offset)860 unsigned int irq_get_next_irq(unsigned int offset)
861 {
862 	return irq_find_at_or_after(offset);
863 }
864 
865 struct irq_desc *
__irq_get_desc_lock(unsigned int irq,unsigned long * flags,bool bus,unsigned int check)866 __irq_get_desc_lock(unsigned int irq, unsigned long *flags, bool bus,
867 		    unsigned int check)
868 {
869 	struct irq_desc *desc = irq_to_desc(irq);
870 
871 	if (desc) {
872 		if (check & _IRQ_DESC_CHECK) {
873 			if ((check & _IRQ_DESC_PERCPU) &&
874 			    !irq_settings_is_per_cpu_devid(desc))
875 				return NULL;
876 
877 			if (!(check & _IRQ_DESC_PERCPU) &&
878 			    irq_settings_is_per_cpu_devid(desc))
879 				return NULL;
880 		}
881 
882 		if (bus)
883 			chip_bus_lock(desc);
884 		raw_spin_lock_irqsave(&desc->lock, *flags);
885 	}
886 	return desc;
887 }
888 
__irq_put_desc_unlock(struct irq_desc * desc,unsigned long flags,bool bus)889 void __irq_put_desc_unlock(struct irq_desc *desc, unsigned long flags, bool bus)
890 	__releases(&desc->lock)
891 {
892 	raw_spin_unlock_irqrestore(&desc->lock, flags);
893 	if (bus)
894 		chip_bus_sync_unlock(desc);
895 }
896 
irq_set_percpu_devid_partition(unsigned int irq,const struct cpumask * affinity)897 int irq_set_percpu_devid_partition(unsigned int irq,
898 				   const struct cpumask *affinity)
899 {
900 	struct irq_desc *desc = irq_to_desc(irq);
901 
902 	if (!desc)
903 		return -EINVAL;
904 
905 	if (desc->percpu_enabled)
906 		return -EINVAL;
907 
908 	desc->percpu_enabled = kzalloc(sizeof(*desc->percpu_enabled), GFP_KERNEL);
909 
910 	if (!desc->percpu_enabled)
911 		return -ENOMEM;
912 
913 	if (affinity)
914 		desc->percpu_affinity = affinity;
915 	else
916 		desc->percpu_affinity = cpu_possible_mask;
917 
918 	irq_set_percpu_devid_flags(irq);
919 	return 0;
920 }
921 
irq_set_percpu_devid(unsigned int irq)922 int irq_set_percpu_devid(unsigned int irq)
923 {
924 	return irq_set_percpu_devid_partition(irq, NULL);
925 }
926 
irq_get_percpu_devid_partition(unsigned int irq,struct cpumask * affinity)927 int irq_get_percpu_devid_partition(unsigned int irq, struct cpumask *affinity)
928 {
929 	struct irq_desc *desc = irq_to_desc(irq);
930 
931 	if (!desc || !desc->percpu_enabled)
932 		return -EINVAL;
933 
934 	if (affinity)
935 		cpumask_copy(affinity, desc->percpu_affinity);
936 
937 	return 0;
938 }
939 EXPORT_SYMBOL_GPL(irq_get_percpu_devid_partition);
940 
kstat_incr_irq_this_cpu(unsigned int irq)941 void kstat_incr_irq_this_cpu(unsigned int irq)
942 {
943 	kstat_incr_irqs_this_cpu(irq_to_desc(irq));
944 }
945 
946 /**
947  * kstat_irqs_cpu - Get the statistics for an interrupt on a cpu
948  * @irq:	The interrupt number
949  * @cpu:	The cpu number
950  *
951  * Returns the sum of interrupt counts on @cpu since boot for
952  * @irq. The caller must ensure that the interrupt is not removed
953  * concurrently.
954  */
kstat_irqs_cpu(unsigned int irq,int cpu)955 unsigned int kstat_irqs_cpu(unsigned int irq, int cpu)
956 {
957 	struct irq_desc *desc = irq_to_desc(irq);
958 
959 	return desc && desc->kstat_irqs ?
960 			*per_cpu_ptr(desc->kstat_irqs, cpu) : 0;
961 }
962 
irq_is_nmi(struct irq_desc * desc)963 static bool irq_is_nmi(struct irq_desc *desc)
964 {
965 	return desc->istate & IRQS_NMI;
966 }
967 
kstat_irqs(unsigned int irq)968 static unsigned int kstat_irqs(unsigned int irq)
969 {
970 	struct irq_desc *desc = irq_to_desc(irq);
971 	unsigned int sum = 0;
972 	int cpu;
973 
974 	if (!desc || !desc->kstat_irqs)
975 		return 0;
976 	if (!irq_settings_is_per_cpu_devid(desc) &&
977 	    !irq_settings_is_per_cpu(desc) &&
978 	    !irq_is_nmi(desc))
979 		return data_race(desc->tot_count);
980 
981 	for_each_possible_cpu(cpu)
982 		sum += data_race(*per_cpu_ptr(desc->kstat_irqs, cpu));
983 	return sum;
984 }
985 
986 /**
987  * kstat_irqs_usr - Get the statistics for an interrupt from thread context
988  * @irq:	The interrupt number
989  *
990  * Returns the sum of interrupt counts on all cpus since boot for @irq.
991  *
992  * It uses rcu to protect the access since a concurrent removal of an
993  * interrupt descriptor is observing an rcu grace period before
994  * delayed_free_desc()/irq_kobj_release().
995  */
kstat_irqs_usr(unsigned int irq)996 unsigned int kstat_irqs_usr(unsigned int irq)
997 {
998 	unsigned int sum;
999 
1000 	rcu_read_lock();
1001 	sum = kstat_irqs(irq);
1002 	rcu_read_unlock();
1003 	return sum;
1004 }
1005 
1006 #ifdef CONFIG_LOCKDEP
__irq_set_lockdep_class(unsigned int irq,struct lock_class_key * lock_class,struct lock_class_key * request_class)1007 void __irq_set_lockdep_class(unsigned int irq, struct lock_class_key *lock_class,
1008 			     struct lock_class_key *request_class)
1009 {
1010 	struct irq_desc *desc = irq_to_desc(irq);
1011 
1012 	if (desc) {
1013 		lockdep_set_class(&desc->lock, lock_class);
1014 		lockdep_set_class(&desc->request_mutex, request_class);
1015 	}
1016 }
1017 EXPORT_SYMBOL_GPL(__irq_set_lockdep_class);
1018 #endif
1019