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 commandline 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->tot_count = 0;
123 	desc->name = NULL;
124 	desc->owner = owner;
125 	for_each_possible_cpu(cpu)
126 		*per_cpu_ptr(desc->kstat_irqs, cpu) = 0;
127 	desc_smp_init(desc, node, affinity);
128 }
129 
130 int nr_irqs = NR_IRQS;
131 EXPORT_SYMBOL_GPL(nr_irqs);
132 
133 static DEFINE_MUTEX(sparse_irq_lock);
134 static DECLARE_BITMAP(allocated_irqs, IRQ_BITMAP_BITS);
135 
136 #ifdef CONFIG_SPARSE_IRQ
137 
138 static void irq_kobj_release(struct kobject *kobj);
139 
140 #ifdef CONFIG_SYSFS
141 static struct kobject *irq_kobj_base;
142 
143 #define IRQ_ATTR_RO(_name) \
144 static struct kobj_attribute _name##_attr = __ATTR_RO(_name)
145 
per_cpu_count_show(struct kobject * kobj,struct kobj_attribute * attr,char * buf)146 static ssize_t per_cpu_count_show(struct kobject *kobj,
147 				  struct kobj_attribute *attr, char *buf)
148 {
149 	struct irq_desc *desc = container_of(kobj, struct irq_desc, kobj);
150 	ssize_t ret = 0;
151 	char *p = "";
152 	int cpu;
153 
154 	for_each_possible_cpu(cpu) {
155 		unsigned int c = irq_desc_kstat_cpu(desc, cpu);
156 
157 		ret += scnprintf(buf + ret, PAGE_SIZE - ret, "%s%u", p, c);
158 		p = ",";
159 	}
160 
161 	ret += scnprintf(buf + ret, PAGE_SIZE - ret, "\n");
162 	return ret;
163 }
164 IRQ_ATTR_RO(per_cpu_count);
165 
chip_name_show(struct kobject * kobj,struct kobj_attribute * attr,char * buf)166 static ssize_t chip_name_show(struct kobject *kobj,
167 			      struct kobj_attribute *attr, char *buf)
168 {
169 	struct irq_desc *desc = container_of(kobj, struct irq_desc, kobj);
170 	ssize_t ret = 0;
171 
172 	raw_spin_lock_irq(&desc->lock);
173 	if (desc->irq_data.chip && desc->irq_data.chip->name) {
174 		ret = scnprintf(buf, PAGE_SIZE, "%s\n",
175 				desc->irq_data.chip->name);
176 	}
177 	raw_spin_unlock_irq(&desc->lock);
178 
179 	return ret;
180 }
181 IRQ_ATTR_RO(chip_name);
182 
hwirq_show(struct kobject * kobj,struct kobj_attribute * attr,char * buf)183 static ssize_t hwirq_show(struct kobject *kobj,
184 			  struct kobj_attribute *attr, char *buf)
185 {
186 	struct irq_desc *desc = container_of(kobj, struct irq_desc, kobj);
187 	ssize_t ret = 0;
188 
189 	raw_spin_lock_irq(&desc->lock);
190 	if (desc->irq_data.domain)
191 		ret = sprintf(buf, "%lu\n", desc->irq_data.hwirq);
192 	raw_spin_unlock_irq(&desc->lock);
193 
194 	return ret;
195 }
196 IRQ_ATTR_RO(hwirq);
197 
type_show(struct kobject * kobj,struct kobj_attribute * attr,char * buf)198 static ssize_t type_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 	ret = sprintf(buf, "%s\n",
206 		      irqd_is_level_type(&desc->irq_data) ? "level" : "edge");
207 	raw_spin_unlock_irq(&desc->lock);
208 
209 	return ret;
210 
211 }
212 IRQ_ATTR_RO(type);
213 
wakeup_show(struct kobject * kobj,struct kobj_attribute * attr,char * buf)214 static ssize_t wakeup_show(struct kobject *kobj,
215 			   struct kobj_attribute *attr, char *buf)
216 {
217 	struct irq_desc *desc = container_of(kobj, struct irq_desc, kobj);
218 	ssize_t ret = 0;
219 
220 	raw_spin_lock_irq(&desc->lock);
221 	ret = sprintf(buf, "%s\n",
222 		      irqd_is_wakeup_set(&desc->irq_data) ? "enabled" : "disabled");
223 	raw_spin_unlock_irq(&desc->lock);
224 
225 	return ret;
226 
227 }
228 IRQ_ATTR_RO(wakeup);
229 
name_show(struct kobject * kobj,struct kobj_attribute * attr,char * buf)230 static ssize_t name_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 	if (desc->name)
238 		ret = scnprintf(buf, PAGE_SIZE, "%s\n", desc->name);
239 	raw_spin_unlock_irq(&desc->lock);
240 
241 	return ret;
242 }
243 IRQ_ATTR_RO(name);
244 
actions_show(struct kobject * kobj,struct kobj_attribute * attr,char * buf)245 static ssize_t actions_show(struct kobject *kobj,
246 			    struct kobj_attribute *attr, char *buf)
247 {
248 	struct irq_desc *desc = container_of(kobj, struct irq_desc, kobj);
249 	struct irqaction *action;
250 	ssize_t ret = 0;
251 	char *p = "";
252 
253 	raw_spin_lock_irq(&desc->lock);
254 	for (action = desc->action; action != NULL; action = action->next) {
255 		ret += scnprintf(buf + ret, PAGE_SIZE - ret, "%s%s",
256 				 p, action->name);
257 		p = ",";
258 	}
259 	raw_spin_unlock_irq(&desc->lock);
260 
261 	if (ret)
262 		ret += scnprintf(buf + ret, PAGE_SIZE - ret, "\n");
263 
264 	return ret;
265 }
266 IRQ_ATTR_RO(actions);
267 
268 static struct attribute *irq_attrs[] = {
269 	&per_cpu_count_attr.attr,
270 	&chip_name_attr.attr,
271 	&hwirq_attr.attr,
272 	&type_attr.attr,
273 	&wakeup_attr.attr,
274 	&name_attr.attr,
275 	&actions_attr.attr,
276 	NULL
277 };
278 ATTRIBUTE_GROUPS(irq);
279 
280 static struct kobj_type irq_kobj_type = {
281 	.release	= irq_kobj_release,
282 	.sysfs_ops	= &kobj_sysfs_ops,
283 	.default_groups = irq_groups,
284 };
285 
irq_sysfs_add(int irq,struct irq_desc * desc)286 static void irq_sysfs_add(int irq, struct irq_desc *desc)
287 {
288 	if (irq_kobj_base) {
289 		/*
290 		 * Continue even in case of failure as this is nothing
291 		 * crucial.
292 		 */
293 		if (kobject_add(&desc->kobj, irq_kobj_base, "%d", irq))
294 			pr_warn("Failed to add kobject for irq %d\n", irq);
295 	}
296 }
297 
irq_sysfs_del(struct irq_desc * desc)298 static void irq_sysfs_del(struct irq_desc *desc)
299 {
300 	/*
301 	 * If irq_sysfs_init() has not yet been invoked (early boot), then
302 	 * irq_kobj_base is NULL and the descriptor was never added.
303 	 * kobject_del() complains about a object with no parent, so make
304 	 * it conditional.
305 	 */
306 	if (irq_kobj_base)
307 		kobject_del(&desc->kobj);
308 }
309 
irq_sysfs_init(void)310 static int __init irq_sysfs_init(void)
311 {
312 	struct irq_desc *desc;
313 	int irq;
314 
315 	/* Prevent concurrent irq alloc/free */
316 	irq_lock_sparse();
317 
318 	irq_kobj_base = kobject_create_and_add("irq", kernel_kobj);
319 	if (!irq_kobj_base) {
320 		irq_unlock_sparse();
321 		return -ENOMEM;
322 	}
323 
324 	/* Add the already allocated interrupts */
325 	for_each_irq_desc(irq, desc)
326 		irq_sysfs_add(irq, desc);
327 	irq_unlock_sparse();
328 
329 	return 0;
330 }
331 postcore_initcall(irq_sysfs_init);
332 
333 #else /* !CONFIG_SYSFS */
334 
335 static struct kobj_type irq_kobj_type = {
336 	.release	= irq_kobj_release,
337 };
338 
irq_sysfs_add(int irq,struct irq_desc * desc)339 static void irq_sysfs_add(int irq, struct irq_desc *desc) {}
irq_sysfs_del(struct irq_desc * desc)340 static void irq_sysfs_del(struct irq_desc *desc) {}
341 
342 #endif /* CONFIG_SYSFS */
343 
344 static RADIX_TREE(irq_desc_tree, GFP_KERNEL);
345 
irq_insert_desc(unsigned int irq,struct irq_desc * desc)346 static void irq_insert_desc(unsigned int irq, struct irq_desc *desc)
347 {
348 	radix_tree_insert(&irq_desc_tree, irq, desc);
349 }
350 
irq_to_desc(unsigned int irq)351 struct irq_desc *irq_to_desc(unsigned int irq)
352 {
353 	return radix_tree_lookup(&irq_desc_tree, irq);
354 }
355 #ifdef CONFIG_KVM_BOOK3S_64_HV_MODULE
356 EXPORT_SYMBOL_GPL(irq_to_desc);
357 #endif
358 
delete_irq_desc(unsigned int irq)359 static void delete_irq_desc(unsigned int irq)
360 {
361 	radix_tree_delete(&irq_desc_tree, irq);
362 }
363 
364 #ifdef CONFIG_SMP
free_masks(struct irq_desc * desc)365 static void free_masks(struct irq_desc *desc)
366 {
367 #ifdef CONFIG_GENERIC_PENDING_IRQ
368 	free_cpumask_var(desc->pending_mask);
369 #endif
370 	free_cpumask_var(desc->irq_common_data.affinity);
371 #ifdef CONFIG_GENERIC_IRQ_EFFECTIVE_AFF_MASK
372 	free_cpumask_var(desc->irq_common_data.effective_affinity);
373 #endif
374 }
375 #else
free_masks(struct irq_desc * desc)376 static inline void free_masks(struct irq_desc *desc) { }
377 #endif
378 
irq_lock_sparse(void)379 void irq_lock_sparse(void)
380 {
381 	mutex_lock(&sparse_irq_lock);
382 }
383 
irq_unlock_sparse(void)384 void irq_unlock_sparse(void)
385 {
386 	mutex_unlock(&sparse_irq_lock);
387 }
388 
alloc_desc(int irq,int node,unsigned int flags,const struct cpumask * affinity,struct module * owner)389 static struct irq_desc *alloc_desc(int irq, int node, unsigned int flags,
390 				   const struct cpumask *affinity,
391 				   struct module *owner)
392 {
393 	struct irq_desc *desc;
394 
395 	desc = kzalloc_node(sizeof(*desc), GFP_KERNEL, node);
396 	if (!desc)
397 		return NULL;
398 	/* allocate based on nr_cpu_ids */
399 	desc->kstat_irqs = alloc_percpu(unsigned int);
400 	if (!desc->kstat_irqs)
401 		goto err_desc;
402 
403 	if (alloc_masks(desc, node))
404 		goto err_kstat;
405 
406 	raw_spin_lock_init(&desc->lock);
407 	lockdep_set_class(&desc->lock, &irq_desc_lock_class);
408 	mutex_init(&desc->request_mutex);
409 	init_rcu_head(&desc->rcu);
410 	init_waitqueue_head(&desc->wait_for_threads);
411 
412 	desc_set_defaults(irq, desc, node, affinity, owner);
413 	irqd_set(&desc->irq_data, flags);
414 	kobject_init(&desc->kobj, &irq_kobj_type);
415 
416 	return desc;
417 
418 err_kstat:
419 	free_percpu(desc->kstat_irqs);
420 err_desc:
421 	kfree(desc);
422 	return NULL;
423 }
424 
irq_kobj_release(struct kobject * kobj)425 static void irq_kobj_release(struct kobject *kobj)
426 {
427 	struct irq_desc *desc = container_of(kobj, struct irq_desc, kobj);
428 
429 	free_masks(desc);
430 	free_percpu(desc->kstat_irqs);
431 	kfree(desc);
432 }
433 
delayed_free_desc(struct rcu_head * rhp)434 static void delayed_free_desc(struct rcu_head *rhp)
435 {
436 	struct irq_desc *desc = container_of(rhp, struct irq_desc, rcu);
437 
438 	kobject_put(&desc->kobj);
439 }
440 
free_desc(unsigned int irq)441 static void free_desc(unsigned int irq)
442 {
443 	struct irq_desc *desc = irq_to_desc(irq);
444 
445 	irq_remove_debugfs_entry(desc);
446 	unregister_irq_proc(irq, desc);
447 
448 	/*
449 	 * sparse_irq_lock protects also show_interrupts() and
450 	 * kstat_irq_usr(). Once we deleted the descriptor from the
451 	 * sparse tree we can free it. Access in proc will fail to
452 	 * lookup the descriptor.
453 	 *
454 	 * The sysfs entry must be serialized against a concurrent
455 	 * irq_sysfs_init() as well.
456 	 */
457 	irq_sysfs_del(desc);
458 	delete_irq_desc(irq);
459 
460 	/*
461 	 * We free the descriptor, masks and stat fields via RCU. That
462 	 * allows demultiplex interrupts to do rcu based management of
463 	 * the child interrupts.
464 	 * This also allows us to use rcu in kstat_irqs_usr().
465 	 */
466 	call_rcu(&desc->rcu, delayed_free_desc);
467 }
468 
alloc_descs(unsigned int start,unsigned int cnt,int node,const struct irq_affinity_desc * affinity,struct module * owner)469 static int alloc_descs(unsigned int start, unsigned int cnt, int node,
470 		       const struct irq_affinity_desc *affinity,
471 		       struct module *owner)
472 {
473 	struct irq_desc *desc;
474 	int i;
475 
476 	/* Validate affinity mask(s) */
477 	if (affinity) {
478 		for (i = 0; i < cnt; i++) {
479 			if (cpumask_empty(&affinity[i].mask))
480 				return -EINVAL;
481 		}
482 	}
483 
484 	for (i = 0; i < cnt; i++) {
485 		const struct cpumask *mask = NULL;
486 		unsigned int flags = 0;
487 
488 		if (affinity) {
489 			if (affinity->is_managed) {
490 				flags = IRQD_AFFINITY_MANAGED |
491 					IRQD_MANAGED_SHUTDOWN;
492 			}
493 			mask = &affinity->mask;
494 			node = cpu_to_node(cpumask_first(mask));
495 			affinity++;
496 		}
497 
498 		desc = alloc_desc(start + i, node, flags, mask, owner);
499 		if (!desc)
500 			goto err;
501 		irq_insert_desc(start + i, desc);
502 		irq_sysfs_add(start + i, desc);
503 		irq_add_debugfs_entry(start + i, desc);
504 	}
505 	bitmap_set(allocated_irqs, start, cnt);
506 	return start;
507 
508 err:
509 	for (i--; i >= 0; i--)
510 		free_desc(start + i);
511 	return -ENOMEM;
512 }
513 
irq_expand_nr_irqs(unsigned int nr)514 static int irq_expand_nr_irqs(unsigned int nr)
515 {
516 	if (nr > IRQ_BITMAP_BITS)
517 		return -ENOMEM;
518 	nr_irqs = nr;
519 	return 0;
520 }
521 
early_irq_init(void)522 int __init early_irq_init(void)
523 {
524 	int i, initcnt, node = first_online_node;
525 	struct irq_desc *desc;
526 
527 	init_irq_default_affinity();
528 
529 	/* Let arch update nr_irqs and return the nr of preallocated irqs */
530 	initcnt = arch_probe_nr_irqs();
531 	printk(KERN_INFO "NR_IRQS: %d, nr_irqs: %d, preallocated irqs: %d\n",
532 	       NR_IRQS, nr_irqs, initcnt);
533 
534 	if (WARN_ON(nr_irqs > IRQ_BITMAP_BITS))
535 		nr_irqs = IRQ_BITMAP_BITS;
536 
537 	if (WARN_ON(initcnt > IRQ_BITMAP_BITS))
538 		initcnt = IRQ_BITMAP_BITS;
539 
540 	if (initcnt > nr_irqs)
541 		nr_irqs = initcnt;
542 
543 	for (i = 0; i < initcnt; i++) {
544 		desc = alloc_desc(i, node, 0, NULL, NULL);
545 		set_bit(i, allocated_irqs);
546 		irq_insert_desc(i, desc);
547 	}
548 	return arch_early_irq_init();
549 }
550 
551 #else /* !CONFIG_SPARSE_IRQ */
552 
553 struct irq_desc irq_desc[NR_IRQS] __cacheline_aligned_in_smp = {
554 	[0 ... NR_IRQS-1] = {
555 		.handle_irq	= handle_bad_irq,
556 		.depth		= 1,
557 		.lock		= __RAW_SPIN_LOCK_UNLOCKED(irq_desc->lock),
558 	}
559 };
560 
early_irq_init(void)561 int __init early_irq_init(void)
562 {
563 	int count, i, node = first_online_node;
564 	struct irq_desc *desc;
565 
566 	init_irq_default_affinity();
567 
568 	printk(KERN_INFO "NR_IRQS: %d\n", NR_IRQS);
569 
570 	desc = irq_desc;
571 	count = ARRAY_SIZE(irq_desc);
572 
573 	for (i = 0; i < count; i++) {
574 		desc[i].kstat_irqs = alloc_percpu(unsigned int);
575 		alloc_masks(&desc[i], node);
576 		raw_spin_lock_init(&desc[i].lock);
577 		lockdep_set_class(&desc[i].lock, &irq_desc_lock_class);
578 		mutex_init(&desc[i].request_mutex);
579 		init_waitqueue_head(&desc[i].wait_for_threads);
580 		desc_set_defaults(i, &desc[i], node, NULL, NULL);
581 	}
582 	return arch_early_irq_init();
583 }
584 
irq_to_desc(unsigned int irq)585 struct irq_desc *irq_to_desc(unsigned int irq)
586 {
587 	return (irq < NR_IRQS) ? irq_desc + irq : NULL;
588 }
589 EXPORT_SYMBOL(irq_to_desc);
590 
free_desc(unsigned int irq)591 static void free_desc(unsigned int irq)
592 {
593 	struct irq_desc *desc = irq_to_desc(irq);
594 	unsigned long flags;
595 
596 	raw_spin_lock_irqsave(&desc->lock, flags);
597 	desc_set_defaults(irq, desc, irq_desc_get_node(desc), NULL, NULL);
598 	raw_spin_unlock_irqrestore(&desc->lock, flags);
599 }
600 
alloc_descs(unsigned int start,unsigned int cnt,int node,const struct irq_affinity_desc * affinity,struct module * owner)601 static inline int alloc_descs(unsigned int start, unsigned int cnt, int node,
602 			      const struct irq_affinity_desc *affinity,
603 			      struct module *owner)
604 {
605 	u32 i;
606 
607 	for (i = 0; i < cnt; i++) {
608 		struct irq_desc *desc = irq_to_desc(start + i);
609 
610 		desc->owner = owner;
611 	}
612 	bitmap_set(allocated_irqs, start, cnt);
613 	return start;
614 }
615 
irq_expand_nr_irqs(unsigned int nr)616 static int irq_expand_nr_irqs(unsigned int nr)
617 {
618 	return -ENOMEM;
619 }
620 
irq_mark_irq(unsigned int irq)621 void irq_mark_irq(unsigned int irq)
622 {
623 	mutex_lock(&sparse_irq_lock);
624 	bitmap_set(allocated_irqs, irq, 1);
625 	mutex_unlock(&sparse_irq_lock);
626 }
627 
628 #ifdef CONFIG_GENERIC_IRQ_LEGACY
irq_init_desc(unsigned int irq)629 void irq_init_desc(unsigned int irq)
630 {
631 	free_desc(irq);
632 }
633 #endif
634 
635 #endif /* !CONFIG_SPARSE_IRQ */
636 
handle_irq_desc(struct irq_desc * desc)637 int handle_irq_desc(struct irq_desc *desc)
638 {
639 	struct irq_data *data;
640 
641 	if (!desc)
642 		return -EINVAL;
643 
644 	data = irq_desc_get_irq_data(desc);
645 	if (WARN_ON_ONCE(!in_hardirq() && handle_enforce_irqctx(data)))
646 		return -EPERM;
647 
648 	generic_handle_irq_desc(desc);
649 	return 0;
650 }
651 
652 /**
653  * generic_handle_irq - Invoke the handler for a particular irq
654  * @irq:	The irq number to handle
655  *
656  * Returns:	0 on success, or -EINVAL if conversion has failed
657  *
658  * 		This function must be called from an IRQ context with irq regs
659  * 		initialized.
660   */
generic_handle_irq(unsigned int irq)661 int generic_handle_irq(unsigned int irq)
662 {
663 	return handle_irq_desc(irq_to_desc(irq));
664 }
665 EXPORT_SYMBOL_GPL(generic_handle_irq);
666 
667 /**
668  * generic_handle_irq_safe - Invoke the handler for a particular irq from any
669  *			     context.
670  * @irq:	The irq number to handle
671  *
672  * Returns:	0 on success, a negative value on error.
673  *
674  * This function can be called from any context (IRQ or process context). It
675  * will report an error if not invoked from IRQ context and the irq has been
676  * marked to enforce IRQ-context only.
677  */
generic_handle_irq_safe(unsigned int irq)678 int generic_handle_irq_safe(unsigned int irq)
679 {
680 	unsigned long flags;
681 	int ret;
682 
683 	local_irq_save(flags);
684 	ret = handle_irq_desc(irq_to_desc(irq));
685 	local_irq_restore(flags);
686 	return ret;
687 }
688 EXPORT_SYMBOL_GPL(generic_handle_irq_safe);
689 
690 #ifdef CONFIG_IRQ_DOMAIN
691 /**
692  * generic_handle_domain_irq - Invoke the handler for a HW irq belonging
693  *                             to a domain.
694  * @domain:	The domain where to perform the lookup
695  * @hwirq:	The HW irq number to convert to a logical one
696  *
697  * Returns:	0 on success, or -EINVAL if conversion has failed
698  *
699  * 		This function must be called from an IRQ context with irq regs
700  * 		initialized.
701  */
generic_handle_domain_irq(struct irq_domain * domain,unsigned int hwirq)702 int generic_handle_domain_irq(struct irq_domain *domain, unsigned int hwirq)
703 {
704 	return handle_irq_desc(irq_resolve_mapping(domain, hwirq));
705 }
706 EXPORT_SYMBOL_GPL(generic_handle_domain_irq);
707 
708 /**
709  * generic_handle_domain_nmi - Invoke the handler for a HW nmi belonging
710  *                             to a domain.
711  * @domain:	The domain where to perform the lookup
712  * @hwirq:	The HW irq number to convert to a logical one
713  *
714  * Returns:	0 on success, or -EINVAL if conversion has failed
715  *
716  * 		This function must be called from an NMI context with irq regs
717  * 		initialized.
718  **/
generic_handle_domain_nmi(struct irq_domain * domain,unsigned int hwirq)719 int generic_handle_domain_nmi(struct irq_domain *domain, unsigned int hwirq)
720 {
721 	WARN_ON_ONCE(!in_nmi());
722 	return handle_irq_desc(irq_resolve_mapping(domain, hwirq));
723 }
724 #endif
725 
726 /* Dynamic interrupt handling */
727 
728 /**
729  * irq_free_descs - free irq descriptors
730  * @from:	Start of descriptor range
731  * @cnt:	Number of consecutive irqs to free
732  */
irq_free_descs(unsigned int from,unsigned int cnt)733 void irq_free_descs(unsigned int from, unsigned int cnt)
734 {
735 	int i;
736 
737 	if (from >= nr_irqs || (from + cnt) > nr_irqs)
738 		return;
739 
740 	mutex_lock(&sparse_irq_lock);
741 	for (i = 0; i < cnt; i++)
742 		free_desc(from + i);
743 
744 	bitmap_clear(allocated_irqs, from, cnt);
745 	mutex_unlock(&sparse_irq_lock);
746 }
747 EXPORT_SYMBOL_GPL(irq_free_descs);
748 
749 /**
750  * __irq_alloc_descs - allocate and initialize a range of irq descriptors
751  * @irq:	Allocate for specific irq number if irq >= 0
752  * @from:	Start the search from this irq number
753  * @cnt:	Number of consecutive irqs to allocate.
754  * @node:	Preferred node on which the irq descriptor should be allocated
755  * @owner:	Owning module (can be NULL)
756  * @affinity:	Optional pointer to an affinity mask array of size @cnt which
757  *		hints where the irq descriptors should be allocated and which
758  *		default affinities to use
759  *
760  * Returns the first irq number or error code
761  */
762 int __ref
__irq_alloc_descs(int irq,unsigned int from,unsigned int cnt,int node,struct module * owner,const struct irq_affinity_desc * affinity)763 __irq_alloc_descs(int irq, unsigned int from, unsigned int cnt, int node,
764 		  struct module *owner, const struct irq_affinity_desc *affinity)
765 {
766 	int start, ret;
767 
768 	if (!cnt)
769 		return -EINVAL;
770 
771 	if (irq >= 0) {
772 		if (from > irq)
773 			return -EINVAL;
774 		from = irq;
775 	} else {
776 		/*
777 		 * For interrupts which are freely allocated the
778 		 * architecture can force a lower bound to the @from
779 		 * argument. x86 uses this to exclude the GSI space.
780 		 */
781 		from = arch_dynirq_lower_bound(from);
782 	}
783 
784 	mutex_lock(&sparse_irq_lock);
785 
786 	start = bitmap_find_next_zero_area(allocated_irqs, IRQ_BITMAP_BITS,
787 					   from, cnt, 0);
788 	ret = -EEXIST;
789 	if (irq >=0 && start != irq)
790 		goto unlock;
791 
792 	if (start + cnt > nr_irqs) {
793 		ret = irq_expand_nr_irqs(start + cnt);
794 		if (ret)
795 			goto unlock;
796 	}
797 	ret = alloc_descs(start, cnt, node, affinity, owner);
798 unlock:
799 	mutex_unlock(&sparse_irq_lock);
800 	return ret;
801 }
802 EXPORT_SYMBOL_GPL(__irq_alloc_descs);
803 
804 /**
805  * irq_get_next_irq - get next allocated irq number
806  * @offset:	where to start the search
807  *
808  * Returns next irq number after offset or nr_irqs if none is found.
809  */
irq_get_next_irq(unsigned int offset)810 unsigned int irq_get_next_irq(unsigned int offset)
811 {
812 	return find_next_bit(allocated_irqs, nr_irqs, offset);
813 }
814 
815 struct irq_desc *
__irq_get_desc_lock(unsigned int irq,unsigned long * flags,bool bus,unsigned int check)816 __irq_get_desc_lock(unsigned int irq, unsigned long *flags, bool bus,
817 		    unsigned int check)
818 {
819 	struct irq_desc *desc = irq_to_desc(irq);
820 
821 	if (desc) {
822 		if (check & _IRQ_DESC_CHECK) {
823 			if ((check & _IRQ_DESC_PERCPU) &&
824 			    !irq_settings_is_per_cpu_devid(desc))
825 				return NULL;
826 
827 			if (!(check & _IRQ_DESC_PERCPU) &&
828 			    irq_settings_is_per_cpu_devid(desc))
829 				return NULL;
830 		}
831 
832 		if (bus)
833 			chip_bus_lock(desc);
834 		raw_spin_lock_irqsave(&desc->lock, *flags);
835 	}
836 	return desc;
837 }
838 
__irq_put_desc_unlock(struct irq_desc * desc,unsigned long flags,bool bus)839 void __irq_put_desc_unlock(struct irq_desc *desc, unsigned long flags, bool bus)
840 	__releases(&desc->lock)
841 {
842 	raw_spin_unlock_irqrestore(&desc->lock, flags);
843 	if (bus)
844 		chip_bus_sync_unlock(desc);
845 }
846 
irq_set_percpu_devid_partition(unsigned int irq,const struct cpumask * affinity)847 int irq_set_percpu_devid_partition(unsigned int irq,
848 				   const struct cpumask *affinity)
849 {
850 	struct irq_desc *desc = irq_to_desc(irq);
851 
852 	if (!desc)
853 		return -EINVAL;
854 
855 	if (desc->percpu_enabled)
856 		return -EINVAL;
857 
858 	desc->percpu_enabled = kzalloc(sizeof(*desc->percpu_enabled), GFP_KERNEL);
859 
860 	if (!desc->percpu_enabled)
861 		return -ENOMEM;
862 
863 	if (affinity)
864 		desc->percpu_affinity = affinity;
865 	else
866 		desc->percpu_affinity = cpu_possible_mask;
867 
868 	irq_set_percpu_devid_flags(irq);
869 	return 0;
870 }
871 
irq_set_percpu_devid(unsigned int irq)872 int irq_set_percpu_devid(unsigned int irq)
873 {
874 	return irq_set_percpu_devid_partition(irq, NULL);
875 }
876 
irq_get_percpu_devid_partition(unsigned int irq,struct cpumask * affinity)877 int irq_get_percpu_devid_partition(unsigned int irq, struct cpumask *affinity)
878 {
879 	struct irq_desc *desc = irq_to_desc(irq);
880 
881 	if (!desc || !desc->percpu_enabled)
882 		return -EINVAL;
883 
884 	if (affinity)
885 		cpumask_copy(affinity, desc->percpu_affinity);
886 
887 	return 0;
888 }
889 EXPORT_SYMBOL_GPL(irq_get_percpu_devid_partition);
890 
kstat_incr_irq_this_cpu(unsigned int irq)891 void kstat_incr_irq_this_cpu(unsigned int irq)
892 {
893 	kstat_incr_irqs_this_cpu(irq_to_desc(irq));
894 }
895 
896 /**
897  * kstat_irqs_cpu - Get the statistics for an interrupt on a cpu
898  * @irq:	The interrupt number
899  * @cpu:	The cpu number
900  *
901  * Returns the sum of interrupt counts on @cpu since boot for
902  * @irq. The caller must ensure that the interrupt is not removed
903  * concurrently.
904  */
kstat_irqs_cpu(unsigned int irq,int cpu)905 unsigned int kstat_irqs_cpu(unsigned int irq, int cpu)
906 {
907 	struct irq_desc *desc = irq_to_desc(irq);
908 
909 	return desc && desc->kstat_irqs ?
910 			*per_cpu_ptr(desc->kstat_irqs, cpu) : 0;
911 }
912 
irq_is_nmi(struct irq_desc * desc)913 static bool irq_is_nmi(struct irq_desc *desc)
914 {
915 	return desc->istate & IRQS_NMI;
916 }
917 
kstat_irqs(unsigned int irq)918 static unsigned int kstat_irqs(unsigned int irq)
919 {
920 	struct irq_desc *desc = irq_to_desc(irq);
921 	unsigned int sum = 0;
922 	int cpu;
923 
924 	if (!desc || !desc->kstat_irqs)
925 		return 0;
926 	if (!irq_settings_is_per_cpu_devid(desc) &&
927 	    !irq_settings_is_per_cpu(desc) &&
928 	    !irq_is_nmi(desc))
929 		return data_race(desc->tot_count);
930 
931 	for_each_possible_cpu(cpu)
932 		sum += data_race(*per_cpu_ptr(desc->kstat_irqs, cpu));
933 	return sum;
934 }
935 
936 /**
937  * kstat_irqs_usr - Get the statistics for an interrupt from thread context
938  * @irq:	The interrupt number
939  *
940  * Returns the sum of interrupt counts on all cpus since boot for @irq.
941  *
942  * It uses rcu to protect the access since a concurrent removal of an
943  * interrupt descriptor is observing an rcu grace period before
944  * delayed_free_desc()/irq_kobj_release().
945  */
kstat_irqs_usr(unsigned int irq)946 unsigned int kstat_irqs_usr(unsigned int irq)
947 {
948 	unsigned int sum;
949 
950 	rcu_read_lock();
951 	sum = kstat_irqs(irq);
952 	rcu_read_unlock();
953 	return sum;
954 }
955 
956 #ifdef CONFIG_LOCKDEP
__irq_set_lockdep_class(unsigned int irq,struct lock_class_key * lock_class,struct lock_class_key * request_class)957 void __irq_set_lockdep_class(unsigned int irq, struct lock_class_key *lock_class,
958 			     struct lock_class_key *request_class)
959 {
960 	struct irq_desc *desc = irq_to_desc(irq);
961 
962 	if (desc) {
963 		lockdep_set_class(&desc->lock, lock_class);
964 		lockdep_set_class(&desc->request_mutex, request_class);
965 	}
966 }
967 EXPORT_SYMBOL_GPL(__irq_set_lockdep_class);
968 #endif
969