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v4.6
 
  1/*
  2 * Copyright (C) 1992, 1998-2006 Linus Torvalds, Ingo Molnar
  3 * Copyright (C) 2005-2006, Thomas Gleixner, Russell King
  4 *
  5 * This file contains the interrupt descriptor management code
  6 *
  7 * Detailed information is available in Documentation/DocBook/genericirq
  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
 19#include "internals.h"
 20
 21/*
 22 * lockdep: we want to handle all irq_desc locks as a single lock-class:
 23 */
 24static struct lock_class_key irq_desc_lock_class;
 25
 26#if defined(CONFIG_SMP)
 27static int __init irq_affinity_setup(char *str)
 28{
 29	zalloc_cpumask_var(&irq_default_affinity, GFP_NOWAIT);
 30	cpulist_parse(str, irq_default_affinity);
 31	/*
 32	 * Set at least the boot cpu. We don't want to end up with
 33	 * bugreports caused by random comandline masks
 34	 */
 35	cpumask_set_cpu(smp_processor_id(), irq_default_affinity);
 36	return 1;
 37}
 38__setup("irqaffinity=", irq_affinity_setup);
 39
 40static void __init init_irq_default_affinity(void)
 41{
 42#ifdef CONFIG_CPUMASK_OFFSTACK
 43	if (!irq_default_affinity)
 44		zalloc_cpumask_var(&irq_default_affinity, GFP_NOWAIT);
 45#endif
 46	if (cpumask_empty(irq_default_affinity))
 47		cpumask_setall(irq_default_affinity);
 48}
 49#else
 50static void __init init_irq_default_affinity(void)
 51{
 52}
 53#endif
 54
 55#ifdef CONFIG_SMP
 56static int alloc_masks(struct irq_desc *desc, gfp_t gfp, int node)
 57{
 58	if (!zalloc_cpumask_var_node(&desc->irq_common_data.affinity,
 59				     gfp, node))
 60		return -ENOMEM;
 61
 
 
 
 
 
 
 
 
 62#ifdef CONFIG_GENERIC_PENDING_IRQ
 63	if (!zalloc_cpumask_var_node(&desc->pending_mask, gfp, node)) {
 
 
 
 64		free_cpumask_var(desc->irq_common_data.affinity);
 65		return -ENOMEM;
 66	}
 67#endif
 68	return 0;
 69}
 70
 71static void desc_smp_init(struct irq_desc *desc, int node)
 
 72{
 73	cpumask_copy(desc->irq_common_data.affinity, irq_default_affinity);
 
 
 
 74#ifdef CONFIG_GENERIC_PENDING_IRQ
 75	cpumask_clear(desc->pending_mask);
 76#endif
 77#ifdef CONFIG_NUMA
 78	desc->irq_common_data.node = node;
 79#endif
 80}
 81
 82#else
 83static inline int
 84alloc_masks(struct irq_desc *desc, gfp_t gfp, int node) { return 0; }
 85static inline void desc_smp_init(struct irq_desc *desc, int node) { }
 
 86#endif
 87
 88static void desc_set_defaults(unsigned int irq, struct irq_desc *desc, int node,
 89		struct module *owner)
 90{
 91	int cpu;
 92
 93	desc->irq_common_data.handler_data = NULL;
 94	desc->irq_common_data.msi_desc = NULL;
 95
 96	desc->irq_data.common = &desc->irq_common_data;
 97	desc->irq_data.irq = irq;
 98	desc->irq_data.chip = &no_irq_chip;
 99	desc->irq_data.chip_data = NULL;
100	irq_settings_clr_and_set(desc, ~0, _IRQ_DEFAULT_INIT_FLAGS);
101	irqd_set(&desc->irq_data, IRQD_IRQ_DISABLED);
 
102	desc->handle_irq = handle_bad_irq;
103	desc->depth = 1;
104	desc->irq_count = 0;
105	desc->irqs_unhandled = 0;
 
106	desc->name = NULL;
107	desc->owner = owner;
108	for_each_possible_cpu(cpu)
109		*per_cpu_ptr(desc->kstat_irqs, cpu) = 0;
110	desc_smp_init(desc, node);
111}
112
113int nr_irqs = NR_IRQS;
114EXPORT_SYMBOL_GPL(nr_irqs);
115
116static DEFINE_MUTEX(sparse_irq_lock);
117static DECLARE_BITMAP(allocated_irqs, IRQ_BITMAP_BITS);
 
 
 
 
118
119#ifdef CONFIG_SPARSE_IRQ
 
 
120
121static RADIX_TREE(irq_desc_tree, GFP_KERNEL);
 
 
 
122
123static void irq_insert_desc(unsigned int irq, struct irq_desc *desc)
124{
125	radix_tree_insert(&irq_desc_tree, irq, desc);
 
 
 
126}
127
128struct irq_desc *irq_to_desc(unsigned int irq)
129{
130	return radix_tree_lookup(&irq_desc_tree, irq);
 
131}
132EXPORT_SYMBOL(irq_to_desc);
133
134static void delete_irq_desc(unsigned int irq)
135{
136	radix_tree_delete(&irq_desc_tree, irq);
 
137}
138
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
139#ifdef CONFIG_SMP
140static void free_masks(struct irq_desc *desc)
141{
142#ifdef CONFIG_GENERIC_PENDING_IRQ
143	free_cpumask_var(desc->pending_mask);
144#endif
145	free_cpumask_var(desc->irq_common_data.affinity);
 
 
 
146}
147#else
148static inline void free_masks(struct irq_desc *desc) { }
149#endif
150
151void irq_lock_sparse(void)
152{
153	mutex_lock(&sparse_irq_lock);
154}
155
156void irq_unlock_sparse(void)
157{
158	mutex_unlock(&sparse_irq_lock);
159}
160
161static struct irq_desc *alloc_desc(int irq, int node, struct module *owner)
 
 
162{
163	struct irq_desc *desc;
164	gfp_t gfp = GFP_KERNEL;
165
166	desc = kzalloc_node(sizeof(*desc), gfp, node);
167	if (!desc)
168		return NULL;
169	/* allocate based on nr_cpu_ids */
170	desc->kstat_irqs = alloc_percpu(unsigned int);
171	if (!desc->kstat_irqs)
172		goto err_desc;
173
174	if (alloc_masks(desc, gfp, node))
175		goto err_kstat;
176
177	raw_spin_lock_init(&desc->lock);
178	lockdep_set_class(&desc->lock, &irq_desc_lock_class);
 
179	init_rcu_head(&desc->rcu);
 
180
181	desc_set_defaults(irq, desc, node, owner);
 
 
 
182
183	return desc;
184
185err_kstat:
186	free_percpu(desc->kstat_irqs);
187err_desc:
188	kfree(desc);
189	return NULL;
190}
191
192static void delayed_free_desc(struct rcu_head *rhp)
193{
194	struct irq_desc *desc = container_of(rhp, struct irq_desc, rcu);
195
196	free_masks(desc);
197	free_percpu(desc->kstat_irqs);
198	kfree(desc);
199}
200
 
 
 
 
 
 
 
201static void free_desc(unsigned int irq)
202{
203	struct irq_desc *desc = irq_to_desc(irq);
204
 
205	unregister_irq_proc(irq, desc);
206
207	/*
208	 * sparse_irq_lock protects also show_interrupts() and
209	 * kstat_irq_usr(). Once we deleted the descriptor from the
210	 * sparse tree we can free it. Access in proc will fail to
211	 * lookup the descriptor.
 
 
 
212	 */
213	mutex_lock(&sparse_irq_lock);
214	delete_irq_desc(irq);
215	mutex_unlock(&sparse_irq_lock);
216
217	/*
218	 * We free the descriptor, masks and stat fields via RCU. That
219	 * allows demultiplex interrupts to do rcu based management of
220	 * the child interrupts.
 
221	 */
222	call_rcu(&desc->rcu, delayed_free_desc);
223}
224
225static int alloc_descs(unsigned int start, unsigned int cnt, int node,
 
226		       struct module *owner)
227{
228	struct irq_desc *desc;
229	int i;
230
 
 
 
 
 
 
 
 
231	for (i = 0; i < cnt; i++) {
232		desc = alloc_desc(start + i, node, owner);
 
 
 
 
 
 
 
 
 
 
 
 
 
233		if (!desc)
234			goto err;
235		mutex_lock(&sparse_irq_lock);
236		irq_insert_desc(start + i, desc);
237		mutex_unlock(&sparse_irq_lock);
 
238	}
239	return start;
240
241err:
242	for (i--; i >= 0; i--)
243		free_desc(start + i);
244
245	mutex_lock(&sparse_irq_lock);
246	bitmap_clear(allocated_irqs, start, cnt);
247	mutex_unlock(&sparse_irq_lock);
248	return -ENOMEM;
249}
250
251static int irq_expand_nr_irqs(unsigned int nr)
252{
253	if (nr > IRQ_BITMAP_BITS)
254		return -ENOMEM;
255	nr_irqs = nr;
256	return 0;
257}
258
259int __init early_irq_init(void)
260{
261	int i, initcnt, node = first_online_node;
262	struct irq_desc *desc;
263
264	init_irq_default_affinity();
265
266	/* Let arch update nr_irqs and return the nr of preallocated irqs */
267	initcnt = arch_probe_nr_irqs();
268	printk(KERN_INFO "NR_IRQS:%d nr_irqs:%d %d\n", NR_IRQS, nr_irqs, initcnt);
 
269
270	if (WARN_ON(nr_irqs > IRQ_BITMAP_BITS))
271		nr_irqs = IRQ_BITMAP_BITS;
272
273	if (WARN_ON(initcnt > IRQ_BITMAP_BITS))
274		initcnt = IRQ_BITMAP_BITS;
275
276	if (initcnt > nr_irqs)
277		nr_irqs = initcnt;
278
279	for (i = 0; i < initcnt; i++) {
280		desc = alloc_desc(i, node, NULL);
281		set_bit(i, allocated_irqs);
282		irq_insert_desc(i, desc);
283	}
284	return arch_early_irq_init();
285}
286
287#else /* !CONFIG_SPARSE_IRQ */
288
289struct irq_desc irq_desc[NR_IRQS] __cacheline_aligned_in_smp = {
290	[0 ... NR_IRQS-1] = {
291		.handle_irq	= handle_bad_irq,
292		.depth		= 1,
293		.lock		= __RAW_SPIN_LOCK_UNLOCKED(irq_desc->lock),
294	}
295};
296
297int __init early_irq_init(void)
298{
299	int count, i, node = first_online_node;
300	struct irq_desc *desc;
301
302	init_irq_default_affinity();
303
304	printk(KERN_INFO "NR_IRQS:%d\n", NR_IRQS);
305
306	desc = irq_desc;
307	count = ARRAY_SIZE(irq_desc);
308
309	for (i = 0; i < count; i++) {
310		desc[i].kstat_irqs = alloc_percpu(unsigned int);
311		alloc_masks(&desc[i], GFP_KERNEL, node);
312		raw_spin_lock_init(&desc[i].lock);
313		lockdep_set_class(&desc[i].lock, &irq_desc_lock_class);
314		desc_set_defaults(i, &desc[i], node, NULL);
 
 
 
315	}
316	return arch_early_irq_init();
317}
318
319struct irq_desc *irq_to_desc(unsigned int irq)
320{
321	return (irq < NR_IRQS) ? irq_desc + irq : NULL;
322}
323EXPORT_SYMBOL(irq_to_desc);
324
325static void free_desc(unsigned int irq)
326{
327	struct irq_desc *desc = irq_to_desc(irq);
328	unsigned long flags;
329
330	raw_spin_lock_irqsave(&desc->lock, flags);
331	desc_set_defaults(irq, desc, irq_desc_get_node(desc), NULL);
332	raw_spin_unlock_irqrestore(&desc->lock, flags);
 
333}
334
335static inline int alloc_descs(unsigned int start, unsigned int cnt, int node,
 
336			      struct module *owner)
337{
338	u32 i;
339
340	for (i = 0; i < cnt; i++) {
341		struct irq_desc *desc = irq_to_desc(start + i);
342
343		desc->owner = owner;
 
344	}
345	return start;
346}
347
348static int irq_expand_nr_irqs(unsigned int nr)
349{
350	return -ENOMEM;
351}
352
353void irq_mark_irq(unsigned int irq)
354{
355	mutex_lock(&sparse_irq_lock);
356	bitmap_set(allocated_irqs, irq, 1);
357	mutex_unlock(&sparse_irq_lock);
358}
359
360#ifdef CONFIG_GENERIC_IRQ_LEGACY
361void irq_init_desc(unsigned int irq)
362{
363	free_desc(irq);
364}
365#endif
366
367#endif /* !CONFIG_SPARSE_IRQ */
368
369/**
370 * generic_handle_irq - Invoke the handler for a particular irq
371 * @irq:	The irq number to handle
372 *
373 */
374int generic_handle_irq(unsigned int irq)
375{
376	struct irq_desc *desc = irq_to_desc(irq);
377
378	if (!desc)
379		return -EINVAL;
 
 
 
 
 
380	generic_handle_irq_desc(desc);
381	return 0;
382}
383EXPORT_SYMBOL_GPL(generic_handle_irq);
384
385#ifdef CONFIG_HANDLE_DOMAIN_IRQ
386/**
387 * __handle_domain_irq - Invoke the handler for a HW irq belonging to a domain
388 * @domain:	The domain where to perform the lookup
389 * @hwirq:	The HW irq number to convert to a logical one
390 * @lookup:	Whether to perform the domain lookup or not
391 * @regs:	Register file coming from the low-level handling code
392 *
393 * Returns:	0 on success, or -EINVAL if conversion has failed
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
394 */
395int __handle_domain_irq(struct irq_domain *domain, unsigned int hwirq,
396			bool lookup, struct pt_regs *regs)
397{
398	struct pt_regs *old_regs = set_irq_regs(regs);
399	unsigned int irq = hwirq;
400	int ret = 0;
401
402	irq_enter();
 
 
 
 
 
403
404#ifdef CONFIG_IRQ_DOMAIN
405	if (lookup)
406		irq = irq_find_mapping(domain, hwirq);
407#endif
 
 
 
 
 
 
 
 
 
 
 
 
 
408
409	/*
410	 * Some hardware gives randomly wrong interrupts.  Rather
411	 * than crashing, do something sensible.
412	 */
413	if (unlikely(!irq || irq >= nr_irqs)) {
414		ack_bad_irq(irq);
415		ret = -EINVAL;
416	} else {
417		generic_handle_irq(irq);
418	}
 
 
 
 
 
 
419
420	irq_exit();
421	set_irq_regs(old_regs);
 
422	return ret;
423}
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
424#endif
425
426/* Dynamic interrupt handling */
427
428/**
429 * irq_free_descs - free irq descriptors
430 * @from:	Start of descriptor range
431 * @cnt:	Number of consecutive irqs to free
432 */
433void irq_free_descs(unsigned int from, unsigned int cnt)
434{
435	int i;
436
437	if (from >= nr_irqs || (from + cnt) > nr_irqs)
438		return;
439
 
440	for (i = 0; i < cnt; i++)
441		free_desc(from + i);
442
443	mutex_lock(&sparse_irq_lock);
444	bitmap_clear(allocated_irqs, from, cnt);
445	mutex_unlock(&sparse_irq_lock);
446}
447EXPORT_SYMBOL_GPL(irq_free_descs);
448
449/**
450 * irq_alloc_descs - allocate and initialize a range of irq descriptors
451 * @irq:	Allocate for specific irq number if irq >= 0
452 * @from:	Start the search from this irq number
453 * @cnt:	Number of consecutive irqs to allocate.
454 * @node:	Preferred node on which the irq descriptor should be allocated
455 * @owner:	Owning module (can be NULL)
 
 
 
456 *
457 * Returns the first irq number or error code
458 */
459int __ref
460__irq_alloc_descs(int irq, unsigned int from, unsigned int cnt, int node,
461		  struct module *owner)
462{
463	int start, ret;
464
465	if (!cnt)
466		return -EINVAL;
467
468	if (irq >= 0) {
469		if (from > irq)
470			return -EINVAL;
471		from = irq;
472	} else {
473		/*
474		 * For interrupts which are freely allocated the
475		 * architecture can force a lower bound to the @from
476		 * argument. x86 uses this to exclude the GSI space.
477		 */
478		from = arch_dynirq_lower_bound(from);
479	}
480
481	mutex_lock(&sparse_irq_lock);
482
483	start = bitmap_find_next_zero_area(allocated_irqs, IRQ_BITMAP_BITS,
484					   from, cnt, 0);
485	ret = -EEXIST;
486	if (irq >=0 && start != irq)
487		goto err;
488
489	if (start + cnt > nr_irqs) {
490		ret = irq_expand_nr_irqs(start + cnt);
491		if (ret)
492			goto err;
493	}
494
495	bitmap_set(allocated_irqs, start, cnt);
496	mutex_unlock(&sparse_irq_lock);
497	return alloc_descs(start, cnt, node, owner);
498
499err:
500	mutex_unlock(&sparse_irq_lock);
501	return ret;
502}
503EXPORT_SYMBOL_GPL(__irq_alloc_descs);
504
505#ifdef CONFIG_GENERIC_IRQ_LEGACY_ALLOC_HWIRQ
506/**
507 * irq_alloc_hwirqs - Allocate an irq descriptor and initialize the hardware
508 * @cnt:	number of interrupts to allocate
509 * @node:	node on which to allocate
510 *
511 * Returns an interrupt number > 0 or 0, if the allocation fails.
512 */
513unsigned int irq_alloc_hwirqs(int cnt, int node)
514{
515	int i, irq = __irq_alloc_descs(-1, 0, cnt, node, NULL);
516
517	if (irq < 0)
518		return 0;
519
520	for (i = irq; cnt > 0; i++, cnt--) {
521		if (arch_setup_hwirq(i, node))
522			goto err;
523		irq_clear_status_flags(i, _IRQ_NOREQUEST);
524	}
525	return irq;
526
527err:
528	for (i--; i >= irq; i--) {
529		irq_set_status_flags(i, _IRQ_NOREQUEST | _IRQ_NOPROBE);
530		arch_teardown_hwirq(i);
531	}
532	irq_free_descs(irq, cnt);
533	return 0;
534}
535EXPORT_SYMBOL_GPL(irq_alloc_hwirqs);
536
537/**
538 * irq_free_hwirqs - Free irq descriptor and cleanup the hardware
539 * @from:	Free from irq number
540 * @cnt:	number of interrupts to free
541 *
542 */
543void irq_free_hwirqs(unsigned int from, int cnt)
544{
545	int i, j;
546
547	for (i = from, j = cnt; j > 0; i++, j--) {
548		irq_set_status_flags(i, _IRQ_NOREQUEST | _IRQ_NOPROBE);
549		arch_teardown_hwirq(i);
550	}
551	irq_free_descs(from, cnt);
552}
553EXPORT_SYMBOL_GPL(irq_free_hwirqs);
554#endif
555
556/**
557 * irq_get_next_irq - get next allocated irq number
558 * @offset:	where to start the search
559 *
560 * Returns next irq number after offset or nr_irqs if none is found.
561 */
562unsigned int irq_get_next_irq(unsigned int offset)
563{
564	return find_next_bit(allocated_irqs, nr_irqs, offset);
565}
566
567struct irq_desc *
568__irq_get_desc_lock(unsigned int irq, unsigned long *flags, bool bus,
569		    unsigned int check)
570{
571	struct irq_desc *desc = irq_to_desc(irq);
572
573	if (desc) {
574		if (check & _IRQ_DESC_CHECK) {
575			if ((check & _IRQ_DESC_PERCPU) &&
576			    !irq_settings_is_per_cpu_devid(desc))
577				return NULL;
578
579			if (!(check & _IRQ_DESC_PERCPU) &&
580			    irq_settings_is_per_cpu_devid(desc))
581				return NULL;
582		}
583
584		if (bus)
585			chip_bus_lock(desc);
586		raw_spin_lock_irqsave(&desc->lock, *flags);
587	}
588	return desc;
589}
590
591void __irq_put_desc_unlock(struct irq_desc *desc, unsigned long flags, bool bus)
 
592{
593	raw_spin_unlock_irqrestore(&desc->lock, flags);
594	if (bus)
595		chip_bus_sync_unlock(desc);
596}
597
598int irq_set_percpu_devid(unsigned int irq)
 
599{
600	struct irq_desc *desc = irq_to_desc(irq);
601
602	if (!desc)
603		return -EINVAL;
604
605	if (desc->percpu_enabled)
606		return -EINVAL;
607
608	desc->percpu_enabled = kzalloc(sizeof(*desc->percpu_enabled), GFP_KERNEL);
609
610	if (!desc->percpu_enabled)
611		return -ENOMEM;
612
 
 
 
 
 
613	irq_set_percpu_devid_flags(irq);
614	return 0;
615}
616
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
617void kstat_incr_irq_this_cpu(unsigned int irq)
618{
619	kstat_incr_irqs_this_cpu(irq_to_desc(irq));
620}
621
622/**
623 * kstat_irqs_cpu - Get the statistics for an interrupt on a cpu
624 * @irq:	The interrupt number
625 * @cpu:	The cpu number
626 *
627 * Returns the sum of interrupt counts on @cpu since boot for
628 * @irq. The caller must ensure that the interrupt is not removed
629 * concurrently.
630 */
631unsigned int kstat_irqs_cpu(unsigned int irq, int cpu)
632{
633	struct irq_desc *desc = irq_to_desc(irq);
634
635	return desc && desc->kstat_irqs ?
636			*per_cpu_ptr(desc->kstat_irqs, cpu) : 0;
637}
638
639/**
640 * kstat_irqs - Get the statistics for an interrupt
641 * @irq:	The interrupt number
642 *
643 * Returns the sum of interrupt counts on all cpus since boot for
644 * @irq. The caller must ensure that the interrupt is not removed
645 * concurrently.
646 */
647unsigned int kstat_irqs(unsigned int irq)
648{
649	struct irq_desc *desc = irq_to_desc(irq);
650	int cpu;
651	unsigned int sum = 0;
 
652
653	if (!desc || !desc->kstat_irqs)
654		return 0;
 
 
 
 
 
655	for_each_possible_cpu(cpu)
656		sum += *per_cpu_ptr(desc->kstat_irqs, cpu);
657	return sum;
658}
659
660/**
661 * kstat_irqs_usr - Get the statistics for an interrupt
662 * @irq:	The interrupt number
663 *
664 * Returns the sum of interrupt counts on all cpus since boot for
665 * @irq. Contrary to kstat_irqs() this can be called from any
666 * preemptible context. It's protected against concurrent removal of
667 * an interrupt descriptor when sparse irqs are enabled.
 
668 */
669unsigned int kstat_irqs_usr(unsigned int irq)
670{
671	unsigned int sum;
672
673	irq_lock_sparse();
674	sum = kstat_irqs(irq);
675	irq_unlock_sparse();
676	return sum;
677}
v6.8
   1// SPDX-License-Identifier: GPL-2.0
   2/*
   3 * Copyright (C) 1992, 1998-2006 Linus Torvalds, Ingo Molnar
   4 * Copyright (C) 2005-2006, Thomas Gleixner, Russell King
   5 *
   6 * This file contains the interrupt descriptor management code. Detailed
   7 * information is available in Documentation/core-api/genericirq.rst
 
   8 *
   9 */
  10#include <linux/irq.h>
  11#include <linux/slab.h>
  12#include <linux/export.h>
  13#include <linux/interrupt.h>
  14#include <linux/kernel_stat.h>
  15#include <linux/maple_tree.h>
 
  16#include <linux/irqdomain.h>
  17#include <linux/sysfs.h>
  18
  19#include "internals.h"
  20
  21/*
  22 * lockdep: we want to handle all irq_desc locks as a single lock-class:
  23 */
  24static struct lock_class_key irq_desc_lock_class;
  25
  26#if defined(CONFIG_SMP)
  27static int __init irq_affinity_setup(char *str)
  28{
  29	alloc_bootmem_cpumask_var(&irq_default_affinity);
  30	cpulist_parse(str, irq_default_affinity);
  31	/*
  32	 * Set at least the boot cpu. We don't want to end up with
  33	 * bugreports caused by random commandline masks
  34	 */
  35	cpumask_set_cpu(smp_processor_id(), irq_default_affinity);
  36	return 1;
  37}
  38__setup("irqaffinity=", irq_affinity_setup);
  39
  40static void __init init_irq_default_affinity(void)
  41{
  42	if (!cpumask_available(irq_default_affinity))
 
  43		zalloc_cpumask_var(&irq_default_affinity, GFP_NOWAIT);
 
  44	if (cpumask_empty(irq_default_affinity))
  45		cpumask_setall(irq_default_affinity);
  46}
  47#else
  48static void __init init_irq_default_affinity(void)
  49{
  50}
  51#endif
  52
  53#ifdef CONFIG_SMP
  54static int alloc_masks(struct irq_desc *desc, int node)
  55{
  56	if (!zalloc_cpumask_var_node(&desc->irq_common_data.affinity,
  57				     GFP_KERNEL, node))
  58		return -ENOMEM;
  59
  60#ifdef CONFIG_GENERIC_IRQ_EFFECTIVE_AFF_MASK
  61	if (!zalloc_cpumask_var_node(&desc->irq_common_data.effective_affinity,
  62				     GFP_KERNEL, node)) {
  63		free_cpumask_var(desc->irq_common_data.affinity);
  64		return -ENOMEM;
  65	}
  66#endif
  67
  68#ifdef CONFIG_GENERIC_PENDING_IRQ
  69	if (!zalloc_cpumask_var_node(&desc->pending_mask, GFP_KERNEL, node)) {
  70#ifdef CONFIG_GENERIC_IRQ_EFFECTIVE_AFF_MASK
  71		free_cpumask_var(desc->irq_common_data.effective_affinity);
  72#endif
  73		free_cpumask_var(desc->irq_common_data.affinity);
  74		return -ENOMEM;
  75	}
  76#endif
  77	return 0;
  78}
  79
  80static void desc_smp_init(struct irq_desc *desc, int node,
  81			  const struct cpumask *affinity)
  82{
  83	if (!affinity)
  84		affinity = irq_default_affinity;
  85	cpumask_copy(desc->irq_common_data.affinity, affinity);
  86
  87#ifdef CONFIG_GENERIC_PENDING_IRQ
  88	cpumask_clear(desc->pending_mask);
  89#endif
  90#ifdef CONFIG_NUMA
  91	desc->irq_common_data.node = node;
  92#endif
  93}
  94
  95#else
  96static inline int
  97alloc_masks(struct irq_desc *desc, int node) { return 0; }
  98static inline void
  99desc_smp_init(struct irq_desc *desc, int node, const struct cpumask *affinity) { }
 100#endif
 101
 102static void desc_set_defaults(unsigned int irq, struct irq_desc *desc, int node,
 103			      const struct cpumask *affinity, struct module *owner)
 104{
 105	int cpu;
 106
 107	desc->irq_common_data.handler_data = NULL;
 108	desc->irq_common_data.msi_desc = NULL;
 109
 110	desc->irq_data.common = &desc->irq_common_data;
 111	desc->irq_data.irq = irq;
 112	desc->irq_data.chip = &no_irq_chip;
 113	desc->irq_data.chip_data = NULL;
 114	irq_settings_clr_and_set(desc, ~0, _IRQ_DEFAULT_INIT_FLAGS);
 115	irqd_set(&desc->irq_data, IRQD_IRQ_DISABLED);
 116	irqd_set(&desc->irq_data, IRQD_IRQ_MASKED);
 117	desc->handle_irq = handle_bad_irq;
 118	desc->depth = 1;
 119	desc->irq_count = 0;
 120	desc->irqs_unhandled = 0;
 121	desc->tot_count = 0;
 122	desc->name = NULL;
 123	desc->owner = owner;
 124	for_each_possible_cpu(cpu)
 125		*per_cpu_ptr(desc->kstat_irqs, cpu) = 0;
 126	desc_smp_init(desc, node, affinity);
 127}
 128
 129int nr_irqs = NR_IRQS;
 130EXPORT_SYMBOL_GPL(nr_irqs);
 131
 132static DEFINE_MUTEX(sparse_irq_lock);
 133static struct maple_tree sparse_irqs = MTREE_INIT_EXT(sparse_irqs,
 134					MT_FLAGS_ALLOC_RANGE |
 135					MT_FLAGS_LOCK_EXTERN |
 136					MT_FLAGS_USE_RCU,
 137					sparse_irq_lock);
 138
 139static int irq_find_free_area(unsigned int from, unsigned int cnt)
 140{
 141	MA_STATE(mas, &sparse_irqs, 0, 0);
 142
 143	if (mas_empty_area(&mas, from, MAX_SPARSE_IRQS, cnt))
 144		return -ENOSPC;
 145	return mas.index;
 146}
 147
 148static unsigned int irq_find_at_or_after(unsigned int offset)
 149{
 150	unsigned long index = offset;
 151	struct irq_desc *desc = mt_find(&sparse_irqs, &index, nr_irqs);
 152
 153	return desc ? irq_desc_get_irq(desc) : nr_irqs;
 154}
 155
 156static void irq_insert_desc(unsigned int irq, struct irq_desc *desc)
 157{
 158	MA_STATE(mas, &sparse_irqs, irq, irq);
 159	WARN_ON(mas_store_gfp(&mas, desc, GFP_KERNEL) != 0);
 160}
 
 161
 162static void delete_irq_desc(unsigned int irq)
 163{
 164	MA_STATE(mas, &sparse_irqs, irq, irq);
 165	mas_erase(&mas);
 166}
 167
 168#ifdef CONFIG_SPARSE_IRQ
 169
 170static void irq_kobj_release(struct kobject *kobj);
 171
 172#ifdef CONFIG_SYSFS
 173static struct kobject *irq_kobj_base;
 174
 175#define IRQ_ATTR_RO(_name) \
 176static struct kobj_attribute _name##_attr = __ATTR_RO(_name)
 177
 178static ssize_t per_cpu_count_show(struct kobject *kobj,
 179				  struct kobj_attribute *attr, char *buf)
 180{
 181	struct irq_desc *desc = container_of(kobj, struct irq_desc, kobj);
 182	ssize_t ret = 0;
 183	char *p = "";
 184	int cpu;
 185
 186	for_each_possible_cpu(cpu) {
 187		unsigned int c = irq_desc_kstat_cpu(desc, cpu);
 188
 189		ret += scnprintf(buf + ret, PAGE_SIZE - ret, "%s%u", p, c);
 190		p = ",";
 191	}
 192
 193	ret += scnprintf(buf + ret, PAGE_SIZE - ret, "\n");
 194	return ret;
 195}
 196IRQ_ATTR_RO(per_cpu_count);
 197
 198static ssize_t chip_name_show(struct kobject *kobj,
 199			      struct kobj_attribute *attr, char *buf)
 200{
 201	struct irq_desc *desc = container_of(kobj, struct irq_desc, kobj);
 202	ssize_t ret = 0;
 203
 204	raw_spin_lock_irq(&desc->lock);
 205	if (desc->irq_data.chip && desc->irq_data.chip->name) {
 206		ret = scnprintf(buf, PAGE_SIZE, "%s\n",
 207				desc->irq_data.chip->name);
 208	}
 209	raw_spin_unlock_irq(&desc->lock);
 210
 211	return ret;
 212}
 213IRQ_ATTR_RO(chip_name);
 214
 215static ssize_t hwirq_show(struct kobject *kobj,
 216			  struct kobj_attribute *attr, char *buf)
 217{
 218	struct irq_desc *desc = container_of(kobj, struct irq_desc, kobj);
 219	ssize_t ret = 0;
 220
 221	raw_spin_lock_irq(&desc->lock);
 222	if (desc->irq_data.domain)
 223		ret = sprintf(buf, "%lu\n", desc->irq_data.hwirq);
 224	raw_spin_unlock_irq(&desc->lock);
 225
 226	return ret;
 227}
 228IRQ_ATTR_RO(hwirq);
 229
 230static ssize_t type_show(struct kobject *kobj,
 231			 struct kobj_attribute *attr, char *buf)
 232{
 233	struct irq_desc *desc = container_of(kobj, struct irq_desc, kobj);
 234	ssize_t ret = 0;
 235
 236	raw_spin_lock_irq(&desc->lock);
 237	ret = sprintf(buf, "%s\n",
 238		      irqd_is_level_type(&desc->irq_data) ? "level" : "edge");
 239	raw_spin_unlock_irq(&desc->lock);
 240
 241	return ret;
 242
 243}
 244IRQ_ATTR_RO(type);
 245
 246static ssize_t wakeup_show(struct kobject *kobj,
 247			   struct kobj_attribute *attr, char *buf)
 248{
 249	struct irq_desc *desc = container_of(kobj, struct irq_desc, kobj);
 250	ssize_t ret = 0;
 251
 252	raw_spin_lock_irq(&desc->lock);
 253	ret = sprintf(buf, "%s\n",
 254		      irqd_is_wakeup_set(&desc->irq_data) ? "enabled" : "disabled");
 255	raw_spin_unlock_irq(&desc->lock);
 256
 257	return ret;
 258
 259}
 260IRQ_ATTR_RO(wakeup);
 261
 262static ssize_t name_show(struct kobject *kobj,
 263			 struct kobj_attribute *attr, char *buf)
 264{
 265	struct irq_desc *desc = container_of(kobj, struct irq_desc, kobj);
 266	ssize_t ret = 0;
 267
 268	raw_spin_lock_irq(&desc->lock);
 269	if (desc->name)
 270		ret = scnprintf(buf, PAGE_SIZE, "%s\n", desc->name);
 271	raw_spin_unlock_irq(&desc->lock);
 272
 273	return ret;
 274}
 275IRQ_ATTR_RO(name);
 276
 277static ssize_t actions_show(struct kobject *kobj,
 278			    struct kobj_attribute *attr, char *buf)
 279{
 280	struct irq_desc *desc = container_of(kobj, struct irq_desc, kobj);
 281	struct irqaction *action;
 282	ssize_t ret = 0;
 283	char *p = "";
 284
 285	raw_spin_lock_irq(&desc->lock);
 286	for_each_action_of_desc(desc, action) {
 287		ret += scnprintf(buf + ret, PAGE_SIZE - ret, "%s%s",
 288				 p, action->name);
 289		p = ",";
 290	}
 291	raw_spin_unlock_irq(&desc->lock);
 292
 293	if (ret)
 294		ret += scnprintf(buf + ret, PAGE_SIZE - ret, "\n");
 295
 296	return ret;
 297}
 298IRQ_ATTR_RO(actions);
 299
 300static struct attribute *irq_attrs[] = {
 301	&per_cpu_count_attr.attr,
 302	&chip_name_attr.attr,
 303	&hwirq_attr.attr,
 304	&type_attr.attr,
 305	&wakeup_attr.attr,
 306	&name_attr.attr,
 307	&actions_attr.attr,
 308	NULL
 309};
 310ATTRIBUTE_GROUPS(irq);
 311
 312static const struct kobj_type irq_kobj_type = {
 313	.release	= irq_kobj_release,
 314	.sysfs_ops	= &kobj_sysfs_ops,
 315	.default_groups = irq_groups,
 316};
 317
 318static void irq_sysfs_add(int irq, struct irq_desc *desc)
 319{
 320	if (irq_kobj_base) {
 321		/*
 322		 * Continue even in case of failure as this is nothing
 323		 * crucial and failures in the late irq_sysfs_init()
 324		 * cannot be rolled back.
 325		 */
 326		if (kobject_add(&desc->kobj, irq_kobj_base, "%d", irq))
 327			pr_warn("Failed to add kobject for irq %d\n", irq);
 328		else
 329			desc->istate |= IRQS_SYSFS;
 330	}
 331}
 332
 333static void irq_sysfs_del(struct irq_desc *desc)
 334{
 335	/*
 336	 * Only invoke kobject_del() when kobject_add() was successfully
 337	 * invoked for the descriptor. This covers both early boot, where
 338	 * sysfs is not initialized yet, and the case of a failed
 339	 * kobject_add() invocation.
 340	 */
 341	if (desc->istate & IRQS_SYSFS)
 342		kobject_del(&desc->kobj);
 343}
 344
 345static int __init irq_sysfs_init(void)
 346{
 347	struct irq_desc *desc;
 348	int irq;
 349
 350	/* Prevent concurrent irq alloc/free */
 351	irq_lock_sparse();
 352
 353	irq_kobj_base = kobject_create_and_add("irq", kernel_kobj);
 354	if (!irq_kobj_base) {
 355		irq_unlock_sparse();
 356		return -ENOMEM;
 357	}
 358
 359	/* Add the already allocated interrupts */
 360	for_each_irq_desc(irq, desc)
 361		irq_sysfs_add(irq, desc);
 362	irq_unlock_sparse();
 363
 364	return 0;
 365}
 366postcore_initcall(irq_sysfs_init);
 367
 368#else /* !CONFIG_SYSFS */
 369
 370static const struct kobj_type irq_kobj_type = {
 371	.release	= irq_kobj_release,
 372};
 373
 374static void irq_sysfs_add(int irq, struct irq_desc *desc) {}
 375static void irq_sysfs_del(struct irq_desc *desc) {}
 376
 377#endif /* CONFIG_SYSFS */
 378
 379struct irq_desc *irq_to_desc(unsigned int irq)
 380{
 381	return mtree_load(&sparse_irqs, irq);
 382}
 383#ifdef CONFIG_KVM_BOOK3S_64_HV_MODULE
 384EXPORT_SYMBOL_GPL(irq_to_desc);
 385#endif
 386
 387#ifdef CONFIG_SMP
 388static void free_masks(struct irq_desc *desc)
 389{
 390#ifdef CONFIG_GENERIC_PENDING_IRQ
 391	free_cpumask_var(desc->pending_mask);
 392#endif
 393	free_cpumask_var(desc->irq_common_data.affinity);
 394#ifdef CONFIG_GENERIC_IRQ_EFFECTIVE_AFF_MASK
 395	free_cpumask_var(desc->irq_common_data.effective_affinity);
 396#endif
 397}
 398#else
 399static inline void free_masks(struct irq_desc *desc) { }
 400#endif
 401
 402void irq_lock_sparse(void)
 403{
 404	mutex_lock(&sparse_irq_lock);
 405}
 406
 407void irq_unlock_sparse(void)
 408{
 409	mutex_unlock(&sparse_irq_lock);
 410}
 411
 412static struct irq_desc *alloc_desc(int irq, int node, unsigned int flags,
 413				   const struct cpumask *affinity,
 414				   struct module *owner)
 415{
 416	struct irq_desc *desc;
 
 417
 418	desc = kzalloc_node(sizeof(*desc), GFP_KERNEL, node);
 419	if (!desc)
 420		return NULL;
 421	/* allocate based on nr_cpu_ids */
 422	desc->kstat_irqs = alloc_percpu(unsigned int);
 423	if (!desc->kstat_irqs)
 424		goto err_desc;
 425
 426	if (alloc_masks(desc, node))
 427		goto err_kstat;
 428
 429	raw_spin_lock_init(&desc->lock);
 430	lockdep_set_class(&desc->lock, &irq_desc_lock_class);
 431	mutex_init(&desc->request_mutex);
 432	init_rcu_head(&desc->rcu);
 433	init_waitqueue_head(&desc->wait_for_threads);
 434
 435	desc_set_defaults(irq, desc, node, affinity, owner);
 436	irqd_set(&desc->irq_data, flags);
 437	kobject_init(&desc->kobj, &irq_kobj_type);
 438	irq_resend_init(desc);
 439
 440	return desc;
 441
 442err_kstat:
 443	free_percpu(desc->kstat_irqs);
 444err_desc:
 445	kfree(desc);
 446	return NULL;
 447}
 448
 449static void irq_kobj_release(struct kobject *kobj)
 450{
 451	struct irq_desc *desc = container_of(kobj, struct irq_desc, kobj);
 452
 453	free_masks(desc);
 454	free_percpu(desc->kstat_irqs);
 455	kfree(desc);
 456}
 457
 458static void delayed_free_desc(struct rcu_head *rhp)
 459{
 460	struct irq_desc *desc = container_of(rhp, struct irq_desc, rcu);
 461
 462	kobject_put(&desc->kobj);
 463}
 464
 465static void free_desc(unsigned int irq)
 466{
 467	struct irq_desc *desc = irq_to_desc(irq);
 468
 469	irq_remove_debugfs_entry(desc);
 470	unregister_irq_proc(irq, desc);
 471
 472	/*
 473	 * sparse_irq_lock protects also show_interrupts() and
 474	 * kstat_irq_usr(). Once we deleted the descriptor from the
 475	 * sparse tree we can free it. Access in proc will fail to
 476	 * lookup the descriptor.
 477	 *
 478	 * The sysfs entry must be serialized against a concurrent
 479	 * irq_sysfs_init() as well.
 480	 */
 481	irq_sysfs_del(desc);
 482	delete_irq_desc(irq);
 
 483
 484	/*
 485	 * We free the descriptor, masks and stat fields via RCU. That
 486	 * allows demultiplex interrupts to do rcu based management of
 487	 * the child interrupts.
 488	 * This also allows us to use rcu in kstat_irqs_usr().
 489	 */
 490	call_rcu(&desc->rcu, delayed_free_desc);
 491}
 492
 493static int alloc_descs(unsigned int start, unsigned int cnt, int node,
 494		       const struct irq_affinity_desc *affinity,
 495		       struct module *owner)
 496{
 497	struct irq_desc *desc;
 498	int i;
 499
 500	/* Validate affinity mask(s) */
 501	if (affinity) {
 502		for (i = 0; i < cnt; i++) {
 503			if (cpumask_empty(&affinity[i].mask))
 504				return -EINVAL;
 505		}
 506	}
 507
 508	for (i = 0; i < cnt; i++) {
 509		const struct cpumask *mask = NULL;
 510		unsigned int flags = 0;
 511
 512		if (affinity) {
 513			if (affinity->is_managed) {
 514				flags = IRQD_AFFINITY_MANAGED |
 515					IRQD_MANAGED_SHUTDOWN;
 516			}
 517			mask = &affinity->mask;
 518			node = cpu_to_node(cpumask_first(mask));
 519			affinity++;
 520		}
 521
 522		desc = alloc_desc(start + i, node, flags, mask, owner);
 523		if (!desc)
 524			goto err;
 
 525		irq_insert_desc(start + i, desc);
 526		irq_sysfs_add(start + i, desc);
 527		irq_add_debugfs_entry(start + i, desc);
 528	}
 529	return start;
 530
 531err:
 532	for (i--; i >= 0; i--)
 533		free_desc(start + i);
 
 
 
 
 534	return -ENOMEM;
 535}
 536
 537static int irq_expand_nr_irqs(unsigned int nr)
 538{
 539	if (nr > MAX_SPARSE_IRQS)
 540		return -ENOMEM;
 541	nr_irqs = nr;
 542	return 0;
 543}
 544
 545int __init early_irq_init(void)
 546{
 547	int i, initcnt, node = first_online_node;
 548	struct irq_desc *desc;
 549
 550	init_irq_default_affinity();
 551
 552	/* Let arch update nr_irqs and return the nr of preallocated irqs */
 553	initcnt = arch_probe_nr_irqs();
 554	printk(KERN_INFO "NR_IRQS: %d, nr_irqs: %d, preallocated irqs: %d\n",
 555	       NR_IRQS, nr_irqs, initcnt);
 556
 557	if (WARN_ON(nr_irqs > MAX_SPARSE_IRQS))
 558		nr_irqs = MAX_SPARSE_IRQS;
 559
 560	if (WARN_ON(initcnt > MAX_SPARSE_IRQS))
 561		initcnt = MAX_SPARSE_IRQS;
 562
 563	if (initcnt > nr_irqs)
 564		nr_irqs = initcnt;
 565
 566	for (i = 0; i < initcnt; i++) {
 567		desc = alloc_desc(i, node, 0, NULL, NULL);
 
 568		irq_insert_desc(i, desc);
 569	}
 570	return arch_early_irq_init();
 571}
 572
 573#else /* !CONFIG_SPARSE_IRQ */
 574
 575struct irq_desc irq_desc[NR_IRQS] __cacheline_aligned_in_smp = {
 576	[0 ... NR_IRQS-1] = {
 577		.handle_irq	= handle_bad_irq,
 578		.depth		= 1,
 579		.lock		= __RAW_SPIN_LOCK_UNLOCKED(irq_desc->lock),
 580	}
 581};
 582
 583int __init early_irq_init(void)
 584{
 585	int count, i, node = first_online_node;
 586	struct irq_desc *desc;
 587
 588	init_irq_default_affinity();
 589
 590	printk(KERN_INFO "NR_IRQS: %d\n", NR_IRQS);
 591
 592	desc = irq_desc;
 593	count = ARRAY_SIZE(irq_desc);
 594
 595	for (i = 0; i < count; i++) {
 596		desc[i].kstat_irqs = alloc_percpu(unsigned int);
 597		alloc_masks(&desc[i], node);
 598		raw_spin_lock_init(&desc[i].lock);
 599		lockdep_set_class(&desc[i].lock, &irq_desc_lock_class);
 600		mutex_init(&desc[i].request_mutex);
 601		init_waitqueue_head(&desc[i].wait_for_threads);
 602		desc_set_defaults(i, &desc[i], node, NULL, NULL);
 603		irq_resend_init(&desc[i]);
 604	}
 605	return arch_early_irq_init();
 606}
 607
 608struct irq_desc *irq_to_desc(unsigned int irq)
 609{
 610	return (irq < NR_IRQS) ? irq_desc + irq : NULL;
 611}
 612EXPORT_SYMBOL(irq_to_desc);
 613
 614static void free_desc(unsigned int irq)
 615{
 616	struct irq_desc *desc = irq_to_desc(irq);
 617	unsigned long flags;
 618
 619	raw_spin_lock_irqsave(&desc->lock, flags);
 620	desc_set_defaults(irq, desc, irq_desc_get_node(desc), NULL, NULL);
 621	raw_spin_unlock_irqrestore(&desc->lock, flags);
 622	delete_irq_desc(irq);
 623}
 624
 625static inline int alloc_descs(unsigned int start, unsigned int cnt, int node,
 626			      const struct irq_affinity_desc *affinity,
 627			      struct module *owner)
 628{
 629	u32 i;
 630
 631	for (i = 0; i < cnt; i++) {
 632		struct irq_desc *desc = irq_to_desc(start + i);
 633
 634		desc->owner = owner;
 635		irq_insert_desc(start + i, desc);
 636	}
 637	return start;
 638}
 639
 640static int irq_expand_nr_irqs(unsigned int nr)
 641{
 642	return -ENOMEM;
 643}
 644
 645void irq_mark_irq(unsigned int irq)
 646{
 647	mutex_lock(&sparse_irq_lock);
 648	irq_insert_desc(irq, irq_desc + irq);
 649	mutex_unlock(&sparse_irq_lock);
 650}
 651
 652#ifdef CONFIG_GENERIC_IRQ_LEGACY
 653void irq_init_desc(unsigned int irq)
 654{
 655	free_desc(irq);
 656}
 657#endif
 658
 659#endif /* !CONFIG_SPARSE_IRQ */
 660
 661int handle_irq_desc(struct irq_desc *desc)
 
 
 
 
 
 662{
 663	struct irq_data *data;
 664
 665	if (!desc)
 666		return -EINVAL;
 667
 668	data = irq_desc_get_irq_data(desc);
 669	if (WARN_ON_ONCE(!in_hardirq() && handle_enforce_irqctx(data)))
 670		return -EPERM;
 671
 672	generic_handle_irq_desc(desc);
 673	return 0;
 674}
 
 675
 
 676/**
 677 * generic_handle_irq - Invoke the handler for a particular irq
 678 * @irq:	The irq number to handle
 
 
 
 679 *
 680 * Returns:	0 on success, or -EINVAL if conversion has failed
 681 *
 682 * 		This function must be called from an IRQ context with irq regs
 683 * 		initialized.
 684  */
 685int generic_handle_irq(unsigned int irq)
 686{
 687	return handle_irq_desc(irq_to_desc(irq));
 688}
 689EXPORT_SYMBOL_GPL(generic_handle_irq);
 690
 691/**
 692 * generic_handle_irq_safe - Invoke the handler for a particular irq from any
 693 *			     context.
 694 * @irq:	The irq number to handle
 695 *
 696 * Returns:	0 on success, a negative value on error.
 697 *
 698 * This function can be called from any context (IRQ or process context). It
 699 * will report an error if not invoked from IRQ context and the irq has been
 700 * marked to enforce IRQ-context only.
 701 */
 702int generic_handle_irq_safe(unsigned int irq)
 
 703{
 704	unsigned long flags;
 705	int ret;
 
 706
 707	local_irq_save(flags);
 708	ret = handle_irq_desc(irq_to_desc(irq));
 709	local_irq_restore(flags);
 710	return ret;
 711}
 712EXPORT_SYMBOL_GPL(generic_handle_irq_safe);
 713
 714#ifdef CONFIG_IRQ_DOMAIN
 715/**
 716 * generic_handle_domain_irq - Invoke the handler for a HW irq belonging
 717 *                             to a domain.
 718 * @domain:	The domain where to perform the lookup
 719 * @hwirq:	The HW irq number to convert to a logical one
 720 *
 721 * Returns:	0 on success, or -EINVAL if conversion has failed
 722 *
 723 * 		This function must be called from an IRQ context with irq regs
 724 * 		initialized.
 725 */
 726int generic_handle_domain_irq(struct irq_domain *domain, unsigned int hwirq)
 727{
 728	return handle_irq_desc(irq_resolve_mapping(domain, hwirq));
 729}
 730EXPORT_SYMBOL_GPL(generic_handle_domain_irq);
 731
 732 /**
 733 * generic_handle_irq_safe - Invoke the handler for a HW irq belonging
 734 *			     to a domain from any context.
 735 * @domain:	The domain where to perform the lookup
 736 * @hwirq:	The HW irq number to convert to a logical one
 737 *
 738 * Returns:	0 on success, a negative value on error.
 739 *
 740 * This function can be called from any context (IRQ or process
 741 * context). If the interrupt is marked as 'enforce IRQ-context only' then
 742 * the function must be invoked from hard interrupt context.
 743 */
 744int generic_handle_domain_irq_safe(struct irq_domain *domain, unsigned int hwirq)
 745{
 746	unsigned long flags;
 747	int ret;
 748
 749	local_irq_save(flags);
 750	ret = handle_irq_desc(irq_resolve_mapping(domain, hwirq));
 751	local_irq_restore(flags);
 752	return ret;
 753}
 754EXPORT_SYMBOL_GPL(generic_handle_domain_irq_safe);
 755
 756/**
 757 * generic_handle_domain_nmi - Invoke the handler for a HW nmi belonging
 758 *                             to a domain.
 759 * @domain:	The domain where to perform the lookup
 760 * @hwirq:	The HW irq number to convert to a logical one
 761 *
 762 * Returns:	0 on success, or -EINVAL if conversion has failed
 763 *
 764 * 		This function must be called from an NMI context with irq regs
 765 * 		initialized.
 766 **/
 767int generic_handle_domain_nmi(struct irq_domain *domain, unsigned int hwirq)
 768{
 769	WARN_ON_ONCE(!in_nmi());
 770	return handle_irq_desc(irq_resolve_mapping(domain, hwirq));
 771}
 772#endif
 773
 774/* Dynamic interrupt handling */
 775
 776/**
 777 * irq_free_descs - free irq descriptors
 778 * @from:	Start of descriptor range
 779 * @cnt:	Number of consecutive irqs to free
 780 */
 781void irq_free_descs(unsigned int from, unsigned int cnt)
 782{
 783	int i;
 784
 785	if (from >= nr_irqs || (from + cnt) > nr_irqs)
 786		return;
 787
 788	mutex_lock(&sparse_irq_lock);
 789	for (i = 0; i < cnt; i++)
 790		free_desc(from + i);
 791
 
 
 792	mutex_unlock(&sparse_irq_lock);
 793}
 794EXPORT_SYMBOL_GPL(irq_free_descs);
 795
 796/**
 797 * __irq_alloc_descs - allocate and initialize a range of irq descriptors
 798 * @irq:	Allocate for specific irq number if irq >= 0
 799 * @from:	Start the search from this irq number
 800 * @cnt:	Number of consecutive irqs to allocate.
 801 * @node:	Preferred node on which the irq descriptor should be allocated
 802 * @owner:	Owning module (can be NULL)
 803 * @affinity:	Optional pointer to an affinity mask array of size @cnt which
 804 *		hints where the irq descriptors should be allocated and which
 805 *		default affinities to use
 806 *
 807 * Returns the first irq number or error code
 808 */
 809int __ref
 810__irq_alloc_descs(int irq, unsigned int from, unsigned int cnt, int node,
 811		  struct module *owner, const struct irq_affinity_desc *affinity)
 812{
 813	int start, ret;
 814
 815	if (!cnt)
 816		return -EINVAL;
 817
 818	if (irq >= 0) {
 819		if (from > irq)
 820			return -EINVAL;
 821		from = irq;
 822	} else {
 823		/*
 824		 * For interrupts which are freely allocated the
 825		 * architecture can force a lower bound to the @from
 826		 * argument. x86 uses this to exclude the GSI space.
 827		 */
 828		from = arch_dynirq_lower_bound(from);
 829	}
 830
 831	mutex_lock(&sparse_irq_lock);
 832
 833	start = irq_find_free_area(from, cnt);
 
 834	ret = -EEXIST;
 835	if (irq >=0 && start != irq)
 836		goto unlock;
 837
 838	if (start + cnt > nr_irqs) {
 839		ret = irq_expand_nr_irqs(start + cnt);
 840		if (ret)
 841			goto unlock;
 842	}
 843	ret = alloc_descs(start, cnt, node, affinity, owner);
 844unlock:
 
 
 
 
 845	mutex_unlock(&sparse_irq_lock);
 846	return ret;
 847}
 848EXPORT_SYMBOL_GPL(__irq_alloc_descs);
 849
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 850/**
 851 * irq_get_next_irq - get next allocated irq number
 852 * @offset:	where to start the search
 853 *
 854 * Returns next irq number after offset or nr_irqs if none is found.
 855 */
 856unsigned int irq_get_next_irq(unsigned int offset)
 857{
 858	return irq_find_at_or_after(offset);
 859}
 860
 861struct irq_desc *
 862__irq_get_desc_lock(unsigned int irq, unsigned long *flags, bool bus,
 863		    unsigned int check)
 864{
 865	struct irq_desc *desc = irq_to_desc(irq);
 866
 867	if (desc) {
 868		if (check & _IRQ_DESC_CHECK) {
 869			if ((check & _IRQ_DESC_PERCPU) &&
 870			    !irq_settings_is_per_cpu_devid(desc))
 871				return NULL;
 872
 873			if (!(check & _IRQ_DESC_PERCPU) &&
 874			    irq_settings_is_per_cpu_devid(desc))
 875				return NULL;
 876		}
 877
 878		if (bus)
 879			chip_bus_lock(desc);
 880		raw_spin_lock_irqsave(&desc->lock, *flags);
 881	}
 882	return desc;
 883}
 884
 885void __irq_put_desc_unlock(struct irq_desc *desc, unsigned long flags, bool bus)
 886	__releases(&desc->lock)
 887{
 888	raw_spin_unlock_irqrestore(&desc->lock, flags);
 889	if (bus)
 890		chip_bus_sync_unlock(desc);
 891}
 892
 893int irq_set_percpu_devid_partition(unsigned int irq,
 894				   const struct cpumask *affinity)
 895{
 896	struct irq_desc *desc = irq_to_desc(irq);
 897
 898	if (!desc)
 899		return -EINVAL;
 900
 901	if (desc->percpu_enabled)
 902		return -EINVAL;
 903
 904	desc->percpu_enabled = kzalloc(sizeof(*desc->percpu_enabled), GFP_KERNEL);
 905
 906	if (!desc->percpu_enabled)
 907		return -ENOMEM;
 908
 909	if (affinity)
 910		desc->percpu_affinity = affinity;
 911	else
 912		desc->percpu_affinity = cpu_possible_mask;
 913
 914	irq_set_percpu_devid_flags(irq);
 915	return 0;
 916}
 917
 918int irq_set_percpu_devid(unsigned int irq)
 919{
 920	return irq_set_percpu_devid_partition(irq, NULL);
 921}
 922
 923int irq_get_percpu_devid_partition(unsigned int irq, struct cpumask *affinity)
 924{
 925	struct irq_desc *desc = irq_to_desc(irq);
 926
 927	if (!desc || !desc->percpu_enabled)
 928		return -EINVAL;
 929
 930	if (affinity)
 931		cpumask_copy(affinity, desc->percpu_affinity);
 932
 933	return 0;
 934}
 935EXPORT_SYMBOL_GPL(irq_get_percpu_devid_partition);
 936
 937void kstat_incr_irq_this_cpu(unsigned int irq)
 938{
 939	kstat_incr_irqs_this_cpu(irq_to_desc(irq));
 940}
 941
 942/**
 943 * kstat_irqs_cpu - Get the statistics for an interrupt on a cpu
 944 * @irq:	The interrupt number
 945 * @cpu:	The cpu number
 946 *
 947 * Returns the sum of interrupt counts on @cpu since boot for
 948 * @irq. The caller must ensure that the interrupt is not removed
 949 * concurrently.
 950 */
 951unsigned int kstat_irqs_cpu(unsigned int irq, int cpu)
 952{
 953	struct irq_desc *desc = irq_to_desc(irq);
 954
 955	return desc && desc->kstat_irqs ?
 956			*per_cpu_ptr(desc->kstat_irqs, cpu) : 0;
 957}
 958
 959static bool irq_is_nmi(struct irq_desc *desc)
 960{
 961	return desc->istate & IRQS_NMI;
 962}
 963
 964static unsigned int kstat_irqs(unsigned int irq)
 
 
 
 965{
 966	struct irq_desc *desc = irq_to_desc(irq);
 
 967	unsigned int sum = 0;
 968	int cpu;
 969
 970	if (!desc || !desc->kstat_irqs)
 971		return 0;
 972	if (!irq_settings_is_per_cpu_devid(desc) &&
 973	    !irq_settings_is_per_cpu(desc) &&
 974	    !irq_is_nmi(desc))
 975		return data_race(desc->tot_count);
 976
 977	for_each_possible_cpu(cpu)
 978		sum += data_race(*per_cpu_ptr(desc->kstat_irqs, cpu));
 979	return sum;
 980}
 981
 982/**
 983 * kstat_irqs_usr - Get the statistics for an interrupt from thread context
 984 * @irq:	The interrupt number
 985 *
 986 * Returns the sum of interrupt counts on all cpus since boot for @irq.
 987 *
 988 * It uses rcu to protect the access since a concurrent removal of an
 989 * interrupt descriptor is observing an rcu grace period before
 990 * delayed_free_desc()/irq_kobj_release().
 991 */
 992unsigned int kstat_irqs_usr(unsigned int irq)
 993{
 994	unsigned int sum;
 995
 996	rcu_read_lock();
 997	sum = kstat_irqs(irq);
 998	rcu_read_unlock();
 999	return sum;
1000}
1001
1002#ifdef CONFIG_LOCKDEP
1003void __irq_set_lockdep_class(unsigned int irq, struct lock_class_key *lock_class,
1004			     struct lock_class_key *request_class)
1005{
1006	struct irq_desc *desc = irq_to_desc(irq);
1007
1008	if (desc) {
1009		lockdep_set_class(&desc->lock, lock_class);
1010		lockdep_set_class(&desc->request_mutex, request_class);
1011	}
1012}
1013EXPORT_SYMBOL_GPL(__irq_set_lockdep_class);
1014#endif