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