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v6.2
  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 */
 25static struct lock_class_key irq_desc_lock_class;
 26
 27#if defined(CONFIG_SMP)
 28static 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
 41static 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
 49static void __init init_irq_default_affinity(void)
 50{
 51}
 52#endif
 53
 54#ifdef CONFIG_SMP
 55static 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
 81static 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
 97static inline int
 98alloc_masks(struct irq_desc *desc, int node) { return 0; }
 99static inline void
100desc_smp_init(struct irq_desc *desc, int node, const struct cpumask *affinity) { }
 
101#endif
102
103static 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
130int nr_irqs = NR_IRQS;
131EXPORT_SYMBOL_GPL(nr_irqs);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
132
133static DEFINE_MUTEX(sparse_irq_lock);
134static DECLARE_BITMAP(allocated_irqs, IRQ_BITMAP_BITS);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
135
136#ifdef CONFIG_SPARSE_IRQ
137
138static void irq_kobj_release(struct kobject *kobj);
139
140#ifdef CONFIG_SYSFS
141static struct kobject *irq_kobj_base;
142
143#define IRQ_ATTR_RO(_name) \
144static struct kobj_attribute _name##_attr = __ATTR_RO(_name)
145
146static 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}
164IRQ_ATTR_RO(per_cpu_count);
165
166static 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}
181IRQ_ATTR_RO(chip_name);
182
183static 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}
196IRQ_ATTR_RO(hwirq);
197
198static 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}
212IRQ_ATTR_RO(type);
213
214static 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}
228IRQ_ATTR_RO(wakeup);
229
230static 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}
243IRQ_ATTR_RO(name);
244
245static 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}
266IRQ_ATTR_RO(actions);
267
268static 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};
278ATTRIBUTE_GROUPS(irq);
279
280static struct kobj_type irq_kobj_type = {
281	.release	= irq_kobj_release,
282	.sysfs_ops	= &kobj_sysfs_ops,
283	.default_groups = irq_groups,
284};
285
286static 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
301static 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
313static 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}
334postcore_initcall(irq_sysfs_init);
335
336#else /* !CONFIG_SYSFS */
337
338static struct kobj_type irq_kobj_type = {
339	.release	= irq_kobj_release,
340};
341
342static void irq_sysfs_add(int irq, struct irq_desc *desc) {}
343static void irq_sysfs_del(struct irq_desc *desc) {}
344
345#endif /* CONFIG_SYSFS */
346
347static RADIX_TREE(irq_desc_tree, GFP_KERNEL);
348
349static void irq_insert_desc(unsigned int irq, struct irq_desc *desc)
350{
351	radix_tree_insert(&irq_desc_tree, irq, desc);
352}
353
354struct 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
359EXPORT_SYMBOL_GPL(irq_to_desc);
360#endif
361
362static void delete_irq_desc(unsigned int irq)
363{
364	radix_tree_delete(&irq_desc_tree, irq);
365}
366
367#ifdef CONFIG_SMP
368static 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
379static inline void free_masks(struct irq_desc *desc) { }
380#endif
381
382void irq_lock_sparse(void)
383{
384	mutex_lock(&sparse_irq_lock);
385}
386
387void irq_unlock_sparse(void)
388{
389	mutex_unlock(&sparse_irq_lock);
390}
391
392static 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
421err_kstat:
422	free_percpu(desc->kstat_irqs);
423err_desc:
424	kfree(desc);
425	return NULL;
426}
427
428static 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
437static 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
444static 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
472static 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
511err:
512	for (i--; i >= 0; i--)
513		free_desc(start + i);
514	return -ENOMEM;
515}
516
517static 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
525int __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
556struct 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
564int __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
588struct irq_desc *irq_to_desc(unsigned int irq)
589{
590	return (irq < NR_IRQS) ? irq_desc + irq : NULL;
591}
592EXPORT_SYMBOL(irq_to_desc);
593
594static 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
604static 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
619static int irq_expand_nr_irqs(unsigned int nr)
620{
621	return -ENOMEM;
622}
623
624void 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
632void irq_init_desc(unsigned int irq)
633{
634	free_desc(irq);
635}
636#endif
637
638#endif /* !CONFIG_SPARSE_IRQ */
639
640int 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  */
664int generic_handle_irq(unsigned int irq)
665{
666	return handle_irq_desc(irq_to_desc(irq));
667}
668EXPORT_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 */
681int 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}
691EXPORT_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 */
705int generic_handle_domain_irq(struct irq_domain *domain, unsigned int hwirq)
706{
707	return handle_irq_desc(irq_resolve_mapping(domain, hwirq));
708}
709EXPORT_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 */
723int 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}
733EXPORT_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 **/
746int 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 */
760void 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}
774EXPORT_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 */
789int __ref
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);
825unlock:
826	mutex_unlock(&sparse_irq_lock);
827	return ret;
828}
829EXPORT_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 */
837unsigned int irq_get_next_irq(unsigned int offset)
838{
839	return find_next_bit(allocated_irqs, nr_irqs, offset);
840}
841
842struct irq_desc *
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
866void __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
874int 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
899int irq_set_percpu_devid(unsigned int irq)
900{
901	return irq_set_percpu_devid_partition(irq, NULL);
902}
903
904int 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}
916EXPORT_SYMBOL_GPL(irq_get_percpu_devid_partition);
917
918void 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 */
932unsigned 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
940static bool irq_is_nmi(struct irq_desc *desc)
941{
942	return desc->istate & IRQS_NMI;
943}
944
945static 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 */
973unsigned 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
984void __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}
994EXPORT_SYMBOL_GPL(__irq_set_lockdep_class);
995#endif
v6.13.7
   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#include <linux/string_choices.h>
  19
  20#include "internals.h"
  21
  22/*
  23 * lockdep: we want to handle all irq_desc locks as a single lock-class:
  24 */
  25static struct lock_class_key irq_desc_lock_class;
  26
  27#if defined(CONFIG_SMP)
  28static 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
  41static 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
  49static void __init init_irq_default_affinity(void)
  50{
  51}
  52#endif
  53
  54#ifdef CONFIG_SMP
  55static 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
  81static 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
  96static void free_masks(struct irq_desc *desc)
  97{
  98#ifdef CONFIG_GENERIC_PENDING_IRQ
  99	free_cpumask_var(desc->pending_mask);
 100#endif
 101	free_cpumask_var(desc->irq_common_data.affinity);
 102#ifdef CONFIG_GENERIC_IRQ_EFFECTIVE_AFF_MASK
 103	free_cpumask_var(desc->irq_common_data.effective_affinity);
 104#endif
 105}
 106
 107#else
 108static inline int
 109alloc_masks(struct irq_desc *desc, int node) { return 0; }
 110static inline void
 111desc_smp_init(struct irq_desc *desc, int node, const struct cpumask *affinity) { }
 112static inline void free_masks(struct irq_desc *desc) { }
 113#endif
 114
 115static void desc_set_defaults(unsigned int irq, struct irq_desc *desc, int node,
 116			      const struct cpumask *affinity, struct module *owner)
 117{
 118	int cpu;
 119
 120	desc->irq_common_data.handler_data = NULL;
 121	desc->irq_common_data.msi_desc = NULL;
 122
 123	desc->irq_data.common = &desc->irq_common_data;
 124	desc->irq_data.irq = irq;
 125	desc->irq_data.chip = &no_irq_chip;
 126	desc->irq_data.chip_data = NULL;
 127	irq_settings_clr_and_set(desc, ~0, _IRQ_DEFAULT_INIT_FLAGS);
 128	irqd_set(&desc->irq_data, IRQD_IRQ_DISABLED);
 129	irqd_set(&desc->irq_data, IRQD_IRQ_MASKED);
 130	desc->handle_irq = handle_bad_irq;
 131	desc->depth = 1;
 132	desc->irq_count = 0;
 133	desc->irqs_unhandled = 0;
 134	desc->tot_count = 0;
 135	desc->name = NULL;
 136	desc->owner = owner;
 137	for_each_possible_cpu(cpu)
 138		*per_cpu_ptr(desc->kstat_irqs, cpu) = (struct irqstat) { };
 139	desc_smp_init(desc, node, affinity);
 140}
 141
 142static unsigned int nr_irqs = NR_IRQS;
 143
 144/**
 145 * irq_get_nr_irqs() - Number of interrupts supported by the system.
 146 */
 147unsigned int irq_get_nr_irqs(void)
 148{
 149	return nr_irqs;
 150}
 151EXPORT_SYMBOL_GPL(irq_get_nr_irqs);
 152
 153/**
 154 * irq_set_nr_irqs() - Set the number of interrupts supported by the system.
 155 * @nr: New number of interrupts.
 156 *
 157 * Return: @nr.
 158 */
 159unsigned int irq_set_nr_irqs(unsigned int nr)
 160{
 161	nr_irqs = nr;
 162
 163	return nr;
 164}
 165EXPORT_SYMBOL_GPL(irq_set_nr_irqs);
 166
 167static DEFINE_MUTEX(sparse_irq_lock);
 168static struct maple_tree sparse_irqs = MTREE_INIT_EXT(sparse_irqs,
 169					MT_FLAGS_ALLOC_RANGE |
 170					MT_FLAGS_LOCK_EXTERN |
 171					MT_FLAGS_USE_RCU,
 172					sparse_irq_lock);
 173
 174static int irq_find_free_area(unsigned int from, unsigned int cnt)
 175{
 176	MA_STATE(mas, &sparse_irqs, 0, 0);
 177
 178	if (mas_empty_area(&mas, from, MAX_SPARSE_IRQS, cnt))
 179		return -ENOSPC;
 180	return mas.index;
 181}
 182
 183static unsigned int irq_find_at_or_after(unsigned int offset)
 184{
 185	unsigned long index = offset;
 186	struct irq_desc *desc;
 187
 188	guard(rcu)();
 189	desc = mt_find(&sparse_irqs, &index, nr_irqs);
 190
 191	return desc ? irq_desc_get_irq(desc) : nr_irqs;
 192}
 193
 194static void irq_insert_desc(unsigned int irq, struct irq_desc *desc)
 195{
 196	MA_STATE(mas, &sparse_irqs, irq, irq);
 197	WARN_ON(mas_store_gfp(&mas, desc, GFP_KERNEL) != 0);
 198}
 199
 200static void delete_irq_desc(unsigned int irq)
 201{
 202	MA_STATE(mas, &sparse_irqs, irq, irq);
 203	mas_erase(&mas);
 204}
 205
 206#ifdef CONFIG_SPARSE_IRQ
 207static const struct kobj_type irq_kobj_type;
 208#endif
 209
 210static int init_desc(struct irq_desc *desc, int irq, int node,
 211		     unsigned int flags,
 212		     const struct cpumask *affinity,
 213		     struct module *owner)
 214{
 215	desc->kstat_irqs = alloc_percpu(struct irqstat);
 216	if (!desc->kstat_irqs)
 217		return -ENOMEM;
 218
 219	if (alloc_masks(desc, node)) {
 220		free_percpu(desc->kstat_irqs);
 221		return -ENOMEM;
 222	}
 223
 224	raw_spin_lock_init(&desc->lock);
 225	lockdep_set_class(&desc->lock, &irq_desc_lock_class);
 226	mutex_init(&desc->request_mutex);
 227	init_waitqueue_head(&desc->wait_for_threads);
 228	desc_set_defaults(irq, desc, node, affinity, owner);
 229	irqd_set(&desc->irq_data, flags);
 230	irq_resend_init(desc);
 231#ifdef CONFIG_SPARSE_IRQ
 232	kobject_init(&desc->kobj, &irq_kobj_type);
 233	init_rcu_head(&desc->rcu);
 234#endif
 235
 236	return 0;
 237}
 238
 239#ifdef CONFIG_SPARSE_IRQ
 240
 241static void irq_kobj_release(struct kobject *kobj);
 242
 243#ifdef CONFIG_SYSFS
 244static struct kobject *irq_kobj_base;
 245
 246#define IRQ_ATTR_RO(_name) \
 247static struct kobj_attribute _name##_attr = __ATTR_RO(_name)
 248
 249static ssize_t per_cpu_count_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	char *p = "";
 255	int cpu;
 256
 257	for_each_possible_cpu(cpu) {
 258		unsigned int c = irq_desc_kstat_cpu(desc, cpu);
 259
 260		ret += scnprintf(buf + ret, PAGE_SIZE - ret, "%s%u", p, c);
 261		p = ",";
 262	}
 263
 264	ret += scnprintf(buf + ret, PAGE_SIZE - ret, "\n");
 265	return ret;
 266}
 267IRQ_ATTR_RO(per_cpu_count);
 268
 269static ssize_t chip_name_show(struct kobject *kobj,
 270			      struct kobj_attribute *attr, char *buf)
 271{
 272	struct irq_desc *desc = container_of(kobj, struct irq_desc, kobj);
 273	ssize_t ret = 0;
 274
 275	raw_spin_lock_irq(&desc->lock);
 276	if (desc->irq_data.chip && desc->irq_data.chip->name) {
 277		ret = scnprintf(buf, PAGE_SIZE, "%s\n",
 278				desc->irq_data.chip->name);
 279	}
 280	raw_spin_unlock_irq(&desc->lock);
 281
 282	return ret;
 283}
 284IRQ_ATTR_RO(chip_name);
 285
 286static ssize_t hwirq_show(struct kobject *kobj,
 287			  struct kobj_attribute *attr, char *buf)
 288{
 289	struct irq_desc *desc = container_of(kobj, struct irq_desc, kobj);
 290	ssize_t ret = 0;
 291
 292	raw_spin_lock_irq(&desc->lock);
 293	if (desc->irq_data.domain)
 294		ret = sprintf(buf, "%lu\n", desc->irq_data.hwirq);
 295	raw_spin_unlock_irq(&desc->lock);
 296
 297	return ret;
 298}
 299IRQ_ATTR_RO(hwirq);
 300
 301static ssize_t type_show(struct kobject *kobj,
 302			 struct kobj_attribute *attr, char *buf)
 303{
 304	struct irq_desc *desc = container_of(kobj, struct irq_desc, kobj);
 305	ssize_t ret = 0;
 306
 307	raw_spin_lock_irq(&desc->lock);
 308	ret = sprintf(buf, "%s\n",
 309		      irqd_is_level_type(&desc->irq_data) ? "level" : "edge");
 310	raw_spin_unlock_irq(&desc->lock);
 311
 312	return ret;
 313
 314}
 315IRQ_ATTR_RO(type);
 316
 317static ssize_t wakeup_show(struct kobject *kobj,
 318			   struct kobj_attribute *attr, char *buf)
 319{
 320	struct irq_desc *desc = container_of(kobj, struct irq_desc, kobj);
 321	ssize_t ret = 0;
 322
 323	raw_spin_lock_irq(&desc->lock);
 324	ret = sprintf(buf, "%s\n", str_enabled_disabled(irqd_is_wakeup_set(&desc->irq_data)));
 
 325	raw_spin_unlock_irq(&desc->lock);
 326
 327	return ret;
 328
 329}
 330IRQ_ATTR_RO(wakeup);
 331
 332static ssize_t name_show(struct kobject *kobj,
 333			 struct kobj_attribute *attr, char *buf)
 334{
 335	struct irq_desc *desc = container_of(kobj, struct irq_desc, kobj);
 336	ssize_t ret = 0;
 337
 338	raw_spin_lock_irq(&desc->lock);
 339	if (desc->name)
 340		ret = scnprintf(buf, PAGE_SIZE, "%s\n", desc->name);
 341	raw_spin_unlock_irq(&desc->lock);
 342
 343	return ret;
 344}
 345IRQ_ATTR_RO(name);
 346
 347static ssize_t actions_show(struct kobject *kobj,
 348			    struct kobj_attribute *attr, char *buf)
 349{
 350	struct irq_desc *desc = container_of(kobj, struct irq_desc, kobj);
 351	struct irqaction *action;
 352	ssize_t ret = 0;
 353	char *p = "";
 354
 355	raw_spin_lock_irq(&desc->lock);
 356	for_each_action_of_desc(desc, action) {
 357		ret += scnprintf(buf + ret, PAGE_SIZE - ret, "%s%s",
 358				 p, action->name);
 359		p = ",";
 360	}
 361	raw_spin_unlock_irq(&desc->lock);
 362
 363	if (ret)
 364		ret += scnprintf(buf + ret, PAGE_SIZE - ret, "\n");
 365
 366	return ret;
 367}
 368IRQ_ATTR_RO(actions);
 369
 370static struct attribute *irq_attrs[] = {
 371	&per_cpu_count_attr.attr,
 372	&chip_name_attr.attr,
 373	&hwirq_attr.attr,
 374	&type_attr.attr,
 375	&wakeup_attr.attr,
 376	&name_attr.attr,
 377	&actions_attr.attr,
 378	NULL
 379};
 380ATTRIBUTE_GROUPS(irq);
 381
 382static const struct kobj_type irq_kobj_type = {
 383	.release	= irq_kobj_release,
 384	.sysfs_ops	= &kobj_sysfs_ops,
 385	.default_groups = irq_groups,
 386};
 387
 388static void irq_sysfs_add(int irq, struct irq_desc *desc)
 389{
 390	if (irq_kobj_base) {
 391		/*
 392		 * Continue even in case of failure as this is nothing
 393		 * crucial and failures in the late irq_sysfs_init()
 394		 * cannot be rolled back.
 395		 */
 396		if (kobject_add(&desc->kobj, irq_kobj_base, "%d", irq))
 397			pr_warn("Failed to add kobject for irq %d\n", irq);
 398		else
 399			desc->istate |= IRQS_SYSFS;
 400	}
 401}
 402
 403static void irq_sysfs_del(struct irq_desc *desc)
 404{
 405	/*
 406	 * Only invoke kobject_del() when kobject_add() was successfully
 407	 * invoked for the descriptor. This covers both early boot, where
 408	 * sysfs is not initialized yet, and the case of a failed
 409	 * kobject_add() invocation.
 410	 */
 411	if (desc->istate & IRQS_SYSFS)
 412		kobject_del(&desc->kobj);
 413}
 414
 415static int __init irq_sysfs_init(void)
 416{
 417	struct irq_desc *desc;
 418	int irq;
 419
 420	/* Prevent concurrent irq alloc/free */
 421	irq_lock_sparse();
 422
 423	irq_kobj_base = kobject_create_and_add("irq", kernel_kobj);
 424	if (!irq_kobj_base) {
 425		irq_unlock_sparse();
 426		return -ENOMEM;
 427	}
 428
 429	/* Add the already allocated interrupts */
 430	for_each_irq_desc(irq, desc)
 431		irq_sysfs_add(irq, desc);
 432	irq_unlock_sparse();
 433
 434	return 0;
 435}
 436postcore_initcall(irq_sysfs_init);
 437
 438#else /* !CONFIG_SYSFS */
 439
 440static const struct kobj_type irq_kobj_type = {
 441	.release	= irq_kobj_release,
 442};
 443
 444static void irq_sysfs_add(int irq, struct irq_desc *desc) {}
 445static void irq_sysfs_del(struct irq_desc *desc) {}
 446
 447#endif /* CONFIG_SYSFS */
 448
 
 
 
 
 
 
 
 449struct irq_desc *irq_to_desc(unsigned int irq)
 450{
 451	return mtree_load(&sparse_irqs, irq);
 452}
 453#ifdef CONFIG_KVM_BOOK3S_64_HV_MODULE
 454EXPORT_SYMBOL_GPL(irq_to_desc);
 455#endif
 456
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 457void irq_lock_sparse(void)
 458{
 459	mutex_lock(&sparse_irq_lock);
 460}
 461
 462void irq_unlock_sparse(void)
 463{
 464	mutex_unlock(&sparse_irq_lock);
 465}
 466
 467static struct irq_desc *alloc_desc(int irq, int node, unsigned int flags,
 468				   const struct cpumask *affinity,
 469				   struct module *owner)
 470{
 471	struct irq_desc *desc;
 472	int ret;
 473
 474	desc = kzalloc_node(sizeof(*desc), GFP_KERNEL, node);
 475	if (!desc)
 476		return NULL;
 
 
 
 
 
 
 
 477
 478	ret = init_desc(desc, irq, node, flags, affinity, owner);
 479	if (unlikely(ret)) {
 480		kfree(desc);
 481		return NULL;
 482	}
 
 
 
 
 483
 484	return desc;
 
 
 
 
 
 
 485}
 486
 487static void irq_kobj_release(struct kobject *kobj)
 488{
 489	struct irq_desc *desc = container_of(kobj, struct irq_desc, kobj);
 490
 491	free_masks(desc);
 492	free_percpu(desc->kstat_irqs);
 493	kfree(desc);
 494}
 495
 496static void delayed_free_desc(struct rcu_head *rhp)
 497{
 498	struct irq_desc *desc = container_of(rhp, struct irq_desc, rcu);
 499
 500	kobject_put(&desc->kobj);
 501}
 502
 503static void free_desc(unsigned int irq)
 504{
 505	struct irq_desc *desc = irq_to_desc(irq);
 506
 507	irq_remove_debugfs_entry(desc);
 508	unregister_irq_proc(irq, desc);
 509
 510	/*
 511	 * sparse_irq_lock protects also show_interrupts() and
 512	 * kstat_irq_usr(). Once we deleted the descriptor from the
 513	 * sparse tree we can free it. Access in proc will fail to
 514	 * lookup the descriptor.
 515	 *
 516	 * The sysfs entry must be serialized against a concurrent
 517	 * irq_sysfs_init() as well.
 518	 */
 519	irq_sysfs_del(desc);
 520	delete_irq_desc(irq);
 521
 522	/*
 523	 * We free the descriptor, masks and stat fields via RCU. That
 524	 * allows demultiplex interrupts to do rcu based management of
 525	 * the child interrupts.
 526	 * This also allows us to use rcu in kstat_irqs_usr().
 527	 */
 528	call_rcu(&desc->rcu, delayed_free_desc);
 529}
 530
 531static int alloc_descs(unsigned int start, unsigned int cnt, int node,
 532		       const struct irq_affinity_desc *affinity,
 533		       struct module *owner)
 534{
 535	struct irq_desc *desc;
 536	int i;
 537
 538	/* Validate affinity mask(s) */
 539	if (affinity) {
 540		for (i = 0; i < cnt; i++) {
 541			if (cpumask_empty(&affinity[i].mask))
 542				return -EINVAL;
 543		}
 544	}
 545
 546	for (i = 0; i < cnt; i++) {
 547		const struct cpumask *mask = NULL;
 548		unsigned int flags = 0;
 549
 550		if (affinity) {
 551			if (affinity->is_managed) {
 552				flags = IRQD_AFFINITY_MANAGED |
 553					IRQD_MANAGED_SHUTDOWN;
 554			}
 555			flags |= IRQD_AFFINITY_SET;
 556			mask = &affinity->mask;
 557			node = cpu_to_node(cpumask_first(mask));
 558			affinity++;
 559		}
 560
 561		desc = alloc_desc(start + i, node, flags, mask, owner);
 562		if (!desc)
 563			goto err;
 564		irq_insert_desc(start + i, desc);
 565		irq_sysfs_add(start + i, desc);
 566		irq_add_debugfs_entry(start + i, desc);
 567	}
 
 568	return start;
 569
 570err:
 571	for (i--; i >= 0; i--)
 572		free_desc(start + i);
 573	return -ENOMEM;
 574}
 575
 576static int irq_expand_nr_irqs(unsigned int nr)
 577{
 578	if (nr > MAX_SPARSE_IRQS)
 579		return -ENOMEM;
 580	nr_irqs = nr;
 581	return 0;
 582}
 583
 584int __init early_irq_init(void)
 585{
 586	int i, initcnt, node = first_online_node;
 587	struct irq_desc *desc;
 588
 589	init_irq_default_affinity();
 590
 591	/* Let arch update nr_irqs and return the nr of preallocated irqs */
 592	initcnt = arch_probe_nr_irqs();
 593	printk(KERN_INFO "NR_IRQS: %d, nr_irqs: %d, preallocated irqs: %d\n",
 594	       NR_IRQS, nr_irqs, initcnt);
 595
 596	if (WARN_ON(nr_irqs > MAX_SPARSE_IRQS))
 597		nr_irqs = MAX_SPARSE_IRQS;
 598
 599	if (WARN_ON(initcnt > MAX_SPARSE_IRQS))
 600		initcnt = MAX_SPARSE_IRQS;
 601
 602	if (initcnt > nr_irqs)
 603		nr_irqs = initcnt;
 604
 605	for (i = 0; i < initcnt; i++) {
 606		desc = alloc_desc(i, node, 0, NULL, NULL);
 
 607		irq_insert_desc(i, desc);
 608	}
 609	return arch_early_irq_init();
 610}
 611
 612#else /* !CONFIG_SPARSE_IRQ */
 613
 614struct irq_desc irq_desc[NR_IRQS] __cacheline_aligned_in_smp = {
 615	[0 ... NR_IRQS-1] = {
 616		.handle_irq	= handle_bad_irq,
 617		.depth		= 1,
 618		.lock		= __RAW_SPIN_LOCK_UNLOCKED(irq_desc->lock),
 619	}
 620};
 621
 622int __init early_irq_init(void)
 623{
 624	int count, i, node = first_online_node;
 625	int ret;
 626
 627	init_irq_default_affinity();
 628
 629	printk(KERN_INFO "NR_IRQS: %d\n", NR_IRQS);
 630
 
 631	count = ARRAY_SIZE(irq_desc);
 632
 633	for (i = 0; i < count; i++) {
 634		ret = init_desc(irq_desc + i, i, node, 0, NULL, NULL);
 635		if (unlikely(ret))
 636			goto __free_desc_res;
 
 
 
 
 637	}
 638
 639	return arch_early_irq_init();
 640
 641__free_desc_res:
 642	while (--i >= 0) {
 643		free_masks(irq_desc + i);
 644		free_percpu(irq_desc[i].kstat_irqs);
 645	}
 646
 647	return ret;
 648}
 649
 650struct irq_desc *irq_to_desc(unsigned int irq)
 651{
 652	return (irq < NR_IRQS) ? irq_desc + irq : NULL;
 653}
 654EXPORT_SYMBOL(irq_to_desc);
 655
 656static void free_desc(unsigned int irq)
 657{
 658	struct irq_desc *desc = irq_to_desc(irq);
 659	unsigned long flags;
 660
 661	raw_spin_lock_irqsave(&desc->lock, flags);
 662	desc_set_defaults(irq, desc, irq_desc_get_node(desc), NULL, NULL);
 663	raw_spin_unlock_irqrestore(&desc->lock, flags);
 664	delete_irq_desc(irq);
 665}
 666
 667static inline int alloc_descs(unsigned int start, unsigned int cnt, int node,
 668			      const struct irq_affinity_desc *affinity,
 669			      struct module *owner)
 670{
 671	u32 i;
 672
 673	for (i = 0; i < cnt; i++) {
 674		struct irq_desc *desc = irq_to_desc(start + i);
 675
 676		desc->owner = owner;
 677		irq_insert_desc(start + i, desc);
 678	}
 
 679	return start;
 680}
 681
 682static int irq_expand_nr_irqs(unsigned int nr)
 683{
 684	return -ENOMEM;
 685}
 686
 687void irq_mark_irq(unsigned int irq)
 688{
 689	mutex_lock(&sparse_irq_lock);
 690	irq_insert_desc(irq, irq_desc + irq);
 691	mutex_unlock(&sparse_irq_lock);
 692}
 693
 694#ifdef CONFIG_GENERIC_IRQ_LEGACY
 695void irq_init_desc(unsigned int irq)
 696{
 697	free_desc(irq);
 698}
 699#endif
 700
 701#endif /* !CONFIG_SPARSE_IRQ */
 702
 703int handle_irq_desc(struct irq_desc *desc)
 704{
 705	struct irq_data *data;
 706
 707	if (!desc)
 708		return -EINVAL;
 709
 710	data = irq_desc_get_irq_data(desc);
 711	if (WARN_ON_ONCE(!in_hardirq() && handle_enforce_irqctx(data)))
 712		return -EPERM;
 713
 714	generic_handle_irq_desc(desc);
 715	return 0;
 716}
 717
 718/**
 719 * generic_handle_irq - Invoke the handler for a particular irq
 720 * @irq:	The irq number to handle
 721 *
 722 * Returns:	0 on success, or -EINVAL if conversion has failed
 723 *
 724 * 		This function must be called from an IRQ context with irq regs
 725 * 		initialized.
 726  */
 727int generic_handle_irq(unsigned int irq)
 728{
 729	return handle_irq_desc(irq_to_desc(irq));
 730}
 731EXPORT_SYMBOL_GPL(generic_handle_irq);
 732
 733/**
 734 * generic_handle_irq_safe - Invoke the handler for a particular irq from any
 735 *			     context.
 736 * @irq:	The irq number to handle
 737 *
 738 * Returns:	0 on success, a negative value on error.
 739 *
 740 * This function can be called from any context (IRQ or process context). It
 741 * will report an error if not invoked from IRQ context and the irq has been
 742 * marked to enforce IRQ-context only.
 743 */
 744int generic_handle_irq_safe(unsigned int irq)
 745{
 746	unsigned long flags;
 747	int ret;
 748
 749	local_irq_save(flags);
 750	ret = handle_irq_desc(irq_to_desc(irq));
 751	local_irq_restore(flags);
 752	return ret;
 753}
 754EXPORT_SYMBOL_GPL(generic_handle_irq_safe);
 755
 756#ifdef CONFIG_IRQ_DOMAIN
 757/**
 758 * generic_handle_domain_irq - Invoke the handler for a HW irq belonging
 759 *                             to a domain.
 760 * @domain:	The domain where to perform the lookup
 761 * @hwirq:	The HW irq number to convert to a logical one
 762 *
 763 * Returns:	0 on success, or -EINVAL if conversion has failed
 764 *
 765 * 		This function must be called from an IRQ context with irq regs
 766 * 		initialized.
 767 */
 768int generic_handle_domain_irq(struct irq_domain *domain, unsigned int hwirq)
 769{
 770	return handle_irq_desc(irq_resolve_mapping(domain, hwirq));
 771}
 772EXPORT_SYMBOL_GPL(generic_handle_domain_irq);
 773
 774 /**
 775 * generic_handle_irq_safe - Invoke the handler for a HW irq belonging
 776 *			     to a domain from any context.
 777 * @domain:	The domain where to perform the lookup
 778 * @hwirq:	The HW irq number to convert to a logical one
 779 *
 780 * Returns:	0 on success, a negative value on error.
 781 *
 782 * This function can be called from any context (IRQ or process
 783 * context). If the interrupt is marked as 'enforce IRQ-context only' then
 784 * the function must be invoked from hard interrupt context.
 785 */
 786int generic_handle_domain_irq_safe(struct irq_domain *domain, unsigned int hwirq)
 787{
 788	unsigned long flags;
 789	int ret;
 790
 791	local_irq_save(flags);
 792	ret = handle_irq_desc(irq_resolve_mapping(domain, hwirq));
 793	local_irq_restore(flags);
 794	return ret;
 795}
 796EXPORT_SYMBOL_GPL(generic_handle_domain_irq_safe);
 797
 798/**
 799 * generic_handle_domain_nmi - Invoke the handler for a HW nmi belonging
 800 *                             to a domain.
 801 * @domain:	The domain where to perform the lookup
 802 * @hwirq:	The HW irq number to convert to a logical one
 803 *
 804 * Returns:	0 on success, or -EINVAL if conversion has failed
 805 *
 806 * 		This function must be called from an NMI context with irq regs
 807 * 		initialized.
 808 **/
 809int generic_handle_domain_nmi(struct irq_domain *domain, unsigned int hwirq)
 810{
 811	WARN_ON_ONCE(!in_nmi());
 812	return handle_irq_desc(irq_resolve_mapping(domain, hwirq));
 813}
 814#endif
 815
 816/* Dynamic interrupt handling */
 817
 818/**
 819 * irq_free_descs - free irq descriptors
 820 * @from:	Start of descriptor range
 821 * @cnt:	Number of consecutive irqs to free
 822 */
 823void irq_free_descs(unsigned int from, unsigned int cnt)
 824{
 825	int i;
 826
 827	if (from >= nr_irqs || (from + cnt) > nr_irqs)
 828		return;
 829
 830	mutex_lock(&sparse_irq_lock);
 831	for (i = 0; i < cnt; i++)
 832		free_desc(from + i);
 833
 
 834	mutex_unlock(&sparse_irq_lock);
 835}
 836EXPORT_SYMBOL_GPL(irq_free_descs);
 837
 838/**
 839 * __irq_alloc_descs - allocate and initialize a range of irq descriptors
 840 * @irq:	Allocate for specific irq number if irq >= 0
 841 * @from:	Start the search from this irq number
 842 * @cnt:	Number of consecutive irqs to allocate.
 843 * @node:	Preferred node on which the irq descriptor should be allocated
 844 * @owner:	Owning module (can be NULL)
 845 * @affinity:	Optional pointer to an affinity mask array of size @cnt which
 846 *		hints where the irq descriptors should be allocated and which
 847 *		default affinities to use
 848 *
 849 * Returns the first irq number or error code
 850 */
 851int __ref
 852__irq_alloc_descs(int irq, unsigned int from, unsigned int cnt, int node,
 853		  struct module *owner, const struct irq_affinity_desc *affinity)
 854{
 855	int start, ret;
 856
 857	if (!cnt)
 858		return -EINVAL;
 859
 860	if (irq >= 0) {
 861		if (from > irq)
 862			return -EINVAL;
 863		from = irq;
 864	} else {
 865		/*
 866		 * For interrupts which are freely allocated the
 867		 * architecture can force a lower bound to the @from
 868		 * argument. x86 uses this to exclude the GSI space.
 869		 */
 870		from = arch_dynirq_lower_bound(from);
 871	}
 872
 873	mutex_lock(&sparse_irq_lock);
 874
 875	start = irq_find_free_area(from, cnt);
 
 876	ret = -EEXIST;
 877	if (irq >=0 && start != irq)
 878		goto unlock;
 879
 880	if (start + cnt > nr_irqs) {
 881		ret = irq_expand_nr_irqs(start + cnt);
 882		if (ret)
 883			goto unlock;
 884	}
 885	ret = alloc_descs(start, cnt, node, affinity, owner);
 886unlock:
 887	mutex_unlock(&sparse_irq_lock);
 888	return ret;
 889}
 890EXPORT_SYMBOL_GPL(__irq_alloc_descs);
 891
 892/**
 893 * irq_get_next_irq - get next allocated irq number
 894 * @offset:	where to start the search
 895 *
 896 * Returns next irq number after offset or nr_irqs if none is found.
 897 */
 898unsigned int irq_get_next_irq(unsigned int offset)
 899{
 900	return irq_find_at_or_after(offset);
 901}
 902
 903struct irq_desc *
 904__irq_get_desc_lock(unsigned int irq, unsigned long *flags, bool bus,
 905		    unsigned int check)
 906{
 907	struct irq_desc *desc = irq_to_desc(irq);
 908
 909	if (desc) {
 910		if (check & _IRQ_DESC_CHECK) {
 911			if ((check & _IRQ_DESC_PERCPU) &&
 912			    !irq_settings_is_per_cpu_devid(desc))
 913				return NULL;
 914
 915			if (!(check & _IRQ_DESC_PERCPU) &&
 916			    irq_settings_is_per_cpu_devid(desc))
 917				return NULL;
 918		}
 919
 920		if (bus)
 921			chip_bus_lock(desc);
 922		raw_spin_lock_irqsave(&desc->lock, *flags);
 923	}
 924	return desc;
 925}
 926
 927void __irq_put_desc_unlock(struct irq_desc *desc, unsigned long flags, bool bus)
 928	__releases(&desc->lock)
 929{
 930	raw_spin_unlock_irqrestore(&desc->lock, flags);
 931	if (bus)
 932		chip_bus_sync_unlock(desc);
 933}
 934
 935int irq_set_percpu_devid_partition(unsigned int irq,
 936				   const struct cpumask *affinity)
 937{
 938	struct irq_desc *desc = irq_to_desc(irq);
 939
 940	if (!desc || desc->percpu_enabled)
 
 
 
 941		return -EINVAL;
 942
 943	desc->percpu_enabled = kzalloc(sizeof(*desc->percpu_enabled), GFP_KERNEL);
 944
 945	if (!desc->percpu_enabled)
 946		return -ENOMEM;
 947
 948	desc->percpu_affinity = affinity ? : cpu_possible_mask;
 
 
 
 949
 950	irq_set_percpu_devid_flags(irq);
 951	return 0;
 952}
 953
 954int irq_set_percpu_devid(unsigned int irq)
 955{
 956	return irq_set_percpu_devid_partition(irq, NULL);
 957}
 958
 959int irq_get_percpu_devid_partition(unsigned int irq, struct cpumask *affinity)
 960{
 961	struct irq_desc *desc = irq_to_desc(irq);
 962
 963	if (!desc || !desc->percpu_enabled)
 964		return -EINVAL;
 965
 966	if (affinity)
 967		cpumask_copy(affinity, desc->percpu_affinity);
 968
 969	return 0;
 970}
 971EXPORT_SYMBOL_GPL(irq_get_percpu_devid_partition);
 972
 973void kstat_incr_irq_this_cpu(unsigned int irq)
 974{
 975	kstat_incr_irqs_this_cpu(irq_to_desc(irq));
 976}
 977
 978/**
 979 * kstat_irqs_cpu - Get the statistics for an interrupt on a cpu
 980 * @irq:	The interrupt number
 981 * @cpu:	The cpu number
 982 *
 983 * Returns the sum of interrupt counts on @cpu since boot for
 984 * @irq. The caller must ensure that the interrupt is not removed
 985 * concurrently.
 986 */
 987unsigned int kstat_irqs_cpu(unsigned int irq, int cpu)
 988{
 989	struct irq_desc *desc = irq_to_desc(irq);
 990
 991	return desc && desc->kstat_irqs ? per_cpu(desc->kstat_irqs->cnt, cpu) : 0;
 
 992}
 993
 994unsigned int kstat_irqs_desc(struct irq_desc *desc, const struct cpumask *cpumask)
 
 
 
 
 
 995{
 
 996	unsigned int sum = 0;
 997	int cpu;
 998
 
 
 999	if (!irq_settings_is_per_cpu_devid(desc) &&
1000	    !irq_settings_is_per_cpu(desc) &&
1001	    !irq_is_nmi(desc))
1002		return data_race(desc->tot_count);
1003
1004	for_each_cpu(cpu, cpumask)
1005		sum += data_race(per_cpu(desc->kstat_irqs->cnt, cpu));
1006	return sum;
1007}
1008
1009static unsigned int kstat_irqs(unsigned int irq)
1010{
1011	struct irq_desc *desc = irq_to_desc(irq);
1012
1013	if (!desc || !desc->kstat_irqs)
1014		return 0;
1015	return kstat_irqs_desc(desc, cpu_possible_mask);
1016}
1017
1018#ifdef CONFIG_GENERIC_IRQ_STAT_SNAPSHOT
1019
1020void kstat_snapshot_irqs(void)
1021{
1022	struct irq_desc *desc;
1023	unsigned int irq;
1024
1025	for_each_irq_desc(irq, desc) {
1026		if (!desc->kstat_irqs)
1027			continue;
1028		this_cpu_write(desc->kstat_irqs->ref, this_cpu_read(desc->kstat_irqs->cnt));
1029	}
1030}
1031
1032unsigned int kstat_get_irq_since_snapshot(unsigned int irq)
1033{
1034	struct irq_desc *desc = irq_to_desc(irq);
1035
1036	if (!desc || !desc->kstat_irqs)
1037		return 0;
1038	return this_cpu_read(desc->kstat_irqs->cnt) - this_cpu_read(desc->kstat_irqs->ref);
1039}
1040
1041#endif
1042
1043/**
1044 * kstat_irqs_usr - Get the statistics for an interrupt from thread context
1045 * @irq:	The interrupt number
1046 *
1047 * Returns the sum of interrupt counts on all cpus since boot for @irq.
1048 *
1049 * It uses rcu to protect the access since a concurrent removal of an
1050 * interrupt descriptor is observing an rcu grace period before
1051 * delayed_free_desc()/irq_kobj_release().
1052 */
1053unsigned int kstat_irqs_usr(unsigned int irq)
1054{
1055	unsigned int sum;
1056
1057	rcu_read_lock();
1058	sum = kstat_irqs(irq);
1059	rcu_read_unlock();
1060	return sum;
1061}
1062
1063#ifdef CONFIG_LOCKDEP
1064void __irq_set_lockdep_class(unsigned int irq, struct lock_class_key *lock_class,
1065			     struct lock_class_key *request_class)
1066{
1067	struct irq_desc *desc = irq_to_desc(irq);
1068
1069	if (desc) {
1070		lockdep_set_class(&desc->lock, lock_class);
1071		lockdep_set_class(&desc->request_mutex, request_class);
1072	}
1073}
1074EXPORT_SYMBOL_GPL(__irq_set_lockdep_class);
1075#endif