ee062b7939d3fce9f2813e2bb8f37c5159448631
[muen/linux.git] / kernel / irq / irqdesc.c
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Copyright (C) 1992, 1998-2006 Linus Torvalds, Ingo Molnar
4  * Copyright (C) 2005-2006, Thomas Gleixner, Russell King
5  *
6  * This file contains the interrupt descriptor management code. Detailed
7  * information is available in Documentation/core-api/genericirq.rst
8  *
9  */
10 #include <linux/irq.h>
11 #include <linux/slab.h>
12 #include <linux/export.h>
13 #include <linux/interrupt.h>
14 #include <linux/kernel_stat.h>
15 #include <linux/radix-tree.h>
16 #include <linux/bitmap.h>
17 #include <linux/irqdomain.h>
18 #include <linux/sysfs.h>
19
20 #include "internals.h"
21
22 /*
23  * lockdep: we want to handle all irq_desc locks as a single lock-class:
24  */
25 static struct lock_class_key irq_desc_lock_class;
26
27 #if defined(CONFIG_SMP)
28 static int __init irq_affinity_setup(char *str)
29 {
30         alloc_bootmem_cpumask_var(&irq_default_affinity);
31         cpulist_parse(str, irq_default_affinity);
32         /*
33          * Set at least the boot cpu. We don't want to end up with
34          * bugreports caused by random comandline masks
35          */
36         cpumask_set_cpu(smp_processor_id(), irq_default_affinity);
37         return 1;
38 }
39 __setup("irqaffinity=", irq_affinity_setup);
40
41 static void __init init_irq_default_affinity(void)
42 {
43         if (!cpumask_available(irq_default_affinity))
44                 zalloc_cpumask_var(&irq_default_affinity, GFP_NOWAIT);
45         if (cpumask_empty(irq_default_affinity))
46                 cpumask_setall(irq_default_affinity);
47 }
48 #else
49 static void __init init_irq_default_affinity(void)
50 {
51 }
52 #endif
53
54 #ifdef CONFIG_SMP
55 static int alloc_masks(struct irq_desc *desc, int node)
56 {
57         if (!zalloc_cpumask_var_node(&desc->irq_common_data.affinity,
58                                      GFP_KERNEL, node))
59                 return -ENOMEM;
60
61 #ifdef CONFIG_GENERIC_IRQ_EFFECTIVE_AFF_MASK
62         if (!zalloc_cpumask_var_node(&desc->irq_common_data.effective_affinity,
63                                      GFP_KERNEL, node)) {
64                 free_cpumask_var(desc->irq_common_data.affinity);
65                 return -ENOMEM;
66         }
67 #endif
68
69 #ifdef CONFIG_GENERIC_PENDING_IRQ
70         if (!zalloc_cpumask_var_node(&desc->pending_mask, GFP_KERNEL, node)) {
71 #ifdef CONFIG_GENERIC_IRQ_EFFECTIVE_AFF_MASK
72                 free_cpumask_var(desc->irq_common_data.effective_affinity);
73 #endif
74                 free_cpumask_var(desc->irq_common_data.affinity);
75                 return -ENOMEM;
76         }
77 #endif
78         return 0;
79 }
80
81 static void desc_smp_init(struct irq_desc *desc, int node,
82                           const struct cpumask *affinity)
83 {
84         if (!affinity)
85                 affinity = irq_default_affinity;
86         cpumask_copy(desc->irq_common_data.affinity, affinity);
87
88 #ifdef CONFIG_GENERIC_PENDING_IRQ
89         cpumask_clear(desc->pending_mask);
90 #endif
91 #ifdef CONFIG_NUMA
92         desc->irq_common_data.node = node;
93 #endif
94 }
95
96 #else
97 static inline int
98 alloc_masks(struct irq_desc *desc, int node) { return 0; }
99 static inline void
100 desc_smp_init(struct irq_desc *desc, int node, const struct cpumask *affinity) { }
101 #endif
102
103 static void desc_set_defaults(unsigned int irq, struct irq_desc *desc, int node,
104                               const struct cpumask *affinity, struct module *owner)
105 {
106         int cpu;
107
108         desc->irq_common_data.handler_data = NULL;
109         desc->irq_common_data.msi_desc = NULL;
110
111         desc->irq_data.common = &desc->irq_common_data;
112         desc->irq_data.irq = irq;
113         desc->irq_data.chip = &no_irq_chip;
114         desc->irq_data.chip_data = NULL;
115         irq_settings_clr_and_set(desc, ~0, _IRQ_DEFAULT_INIT_FLAGS);
116         irqd_set(&desc->irq_data, IRQD_IRQ_DISABLED);
117         irqd_set(&desc->irq_data, IRQD_IRQ_MASKED);
118         desc->handle_irq = handle_bad_irq;
119         desc->depth = 1;
120         desc->irq_count = 0;
121         desc->irqs_unhandled = 0;
122         desc->name = NULL;
123         desc->owner = owner;
124         for_each_possible_cpu(cpu)
125                 *per_cpu_ptr(desc->kstat_irqs, cpu) = 0;
126         desc_smp_init(desc, node, affinity);
127 }
128
129 int nr_irqs = NR_IRQS;
130 EXPORT_SYMBOL_GPL(nr_irqs);
131
132 static DEFINE_MUTEX(sparse_irq_lock);
133 static DECLARE_BITMAP(allocated_irqs, IRQ_BITMAP_BITS);
134
135 #ifdef CONFIG_SPARSE_IRQ
136
137 static void irq_kobj_release(struct kobject *kobj);
138
139 #ifdef CONFIG_SYSFS
140 static struct kobject *irq_kobj_base;
141
142 #define IRQ_ATTR_RO(_name) \
143 static struct kobj_attribute _name##_attr = __ATTR_RO(_name)
144
145 static ssize_t per_cpu_count_show(struct kobject *kobj,
146                                   struct kobj_attribute *attr, char *buf)
147 {
148         struct irq_desc *desc = container_of(kobj, struct irq_desc, kobj);
149         int cpu, irq = desc->irq_data.irq;
150         ssize_t ret = 0;
151         char *p = "";
152
153         for_each_possible_cpu(cpu) {
154                 unsigned int c = kstat_irqs_cpu(irq, cpu);
155
156                 ret += scnprintf(buf + ret, PAGE_SIZE - ret, "%s%u", p, c);
157                 p = ",";
158         }
159
160         ret += scnprintf(buf + ret, PAGE_SIZE - ret, "\n");
161         return ret;
162 }
163 IRQ_ATTR_RO(per_cpu_count);
164
165 static ssize_t chip_name_show(struct kobject *kobj,
166                               struct kobj_attribute *attr, char *buf)
167 {
168         struct irq_desc *desc = container_of(kobj, struct irq_desc, kobj);
169         ssize_t ret = 0;
170
171         raw_spin_lock_irq(&desc->lock);
172         if (desc->irq_data.chip && desc->irq_data.chip->name) {
173                 ret = scnprintf(buf, PAGE_SIZE, "%s\n",
174                                 desc->irq_data.chip->name);
175         }
176         raw_spin_unlock_irq(&desc->lock);
177
178         return ret;
179 }
180 IRQ_ATTR_RO(chip_name);
181
182 static ssize_t hwirq_show(struct kobject *kobj,
183                           struct kobj_attribute *attr, char *buf)
184 {
185         struct irq_desc *desc = container_of(kobj, struct irq_desc, kobj);
186         ssize_t ret = 0;
187
188         raw_spin_lock_irq(&desc->lock);
189         if (desc->irq_data.domain)
190                 ret = sprintf(buf, "%d\n", (int)desc->irq_data.hwirq);
191         raw_spin_unlock_irq(&desc->lock);
192
193         return ret;
194 }
195 IRQ_ATTR_RO(hwirq);
196
197 static ssize_t type_show(struct kobject *kobj,
198                          struct kobj_attribute *attr, char *buf)
199 {
200         struct irq_desc *desc = container_of(kobj, struct irq_desc, kobj);
201         ssize_t ret = 0;
202
203         raw_spin_lock_irq(&desc->lock);
204         ret = sprintf(buf, "%s\n",
205                       irqd_is_level_type(&desc->irq_data) ? "level" : "edge");
206         raw_spin_unlock_irq(&desc->lock);
207
208         return ret;
209
210 }
211 IRQ_ATTR_RO(type);
212
213 static ssize_t wakeup_show(struct kobject *kobj,
214                            struct kobj_attribute *attr, char *buf)
215 {
216         struct irq_desc *desc = container_of(kobj, struct irq_desc, kobj);
217         ssize_t ret = 0;
218
219         raw_spin_lock_irq(&desc->lock);
220         ret = sprintf(buf, "%s\n",
221                       irqd_is_wakeup_set(&desc->irq_data) ? "enabled" : "disabled");
222         raw_spin_unlock_irq(&desc->lock);
223
224         return ret;
225
226 }
227 IRQ_ATTR_RO(wakeup);
228
229 static ssize_t name_show(struct kobject *kobj,
230                          struct kobj_attribute *attr, char *buf)
231 {
232         struct irq_desc *desc = container_of(kobj, struct irq_desc, kobj);
233         ssize_t ret = 0;
234
235         raw_spin_lock_irq(&desc->lock);
236         if (desc->name)
237                 ret = scnprintf(buf, PAGE_SIZE, "%s\n", desc->name);
238         raw_spin_unlock_irq(&desc->lock);
239
240         return ret;
241 }
242 IRQ_ATTR_RO(name);
243
244 static ssize_t actions_show(struct kobject *kobj,
245                             struct kobj_attribute *attr, char *buf)
246 {
247         struct irq_desc *desc = container_of(kobj, struct irq_desc, kobj);
248         struct irqaction *action;
249         ssize_t ret = 0;
250         char *p = "";
251
252         raw_spin_lock_irq(&desc->lock);
253         for (action = desc->action; action != NULL; action = action->next) {
254                 ret += scnprintf(buf + ret, PAGE_SIZE - ret, "%s%s",
255                                  p, action->name);
256                 p = ",";
257         }
258         raw_spin_unlock_irq(&desc->lock);
259
260         if (ret)
261                 ret += scnprintf(buf + ret, PAGE_SIZE - ret, "\n");
262
263         return ret;
264 }
265 IRQ_ATTR_RO(actions);
266
267 static struct attribute *irq_attrs[] = {
268         &per_cpu_count_attr.attr,
269         &chip_name_attr.attr,
270         &hwirq_attr.attr,
271         &type_attr.attr,
272         &wakeup_attr.attr,
273         &name_attr.attr,
274         &actions_attr.attr,
275         NULL
276 };
277
278 static struct kobj_type irq_kobj_type = {
279         .release        = irq_kobj_release,
280         .sysfs_ops      = &kobj_sysfs_ops,
281         .default_attrs  = irq_attrs,
282 };
283
284 static void irq_sysfs_add(int irq, struct irq_desc *desc)
285 {
286         if (irq_kobj_base) {
287                 /*
288                  * Continue even in case of failure as this is nothing
289                  * crucial.
290                  */
291                 if (kobject_add(&desc->kobj, irq_kobj_base, "%d", irq))
292                         pr_warn("Failed to add kobject for irq %d\n", irq);
293         }
294 }
295
296 static int __init irq_sysfs_init(void)
297 {
298         struct irq_desc *desc;
299         int irq;
300
301         /* Prevent concurrent irq alloc/free */
302         irq_lock_sparse();
303
304         irq_kobj_base = kobject_create_and_add("irq", kernel_kobj);
305         if (!irq_kobj_base) {
306                 irq_unlock_sparse();
307                 return -ENOMEM;
308         }
309
310         /* Add the already allocated interrupts */
311         for_each_irq_desc(irq, desc)
312                 irq_sysfs_add(irq, desc);
313         irq_unlock_sparse();
314
315         return 0;
316 }
317 postcore_initcall(irq_sysfs_init);
318
319 #else /* !CONFIG_SYSFS */
320
321 static struct kobj_type irq_kobj_type = {
322         .release        = irq_kobj_release,
323 };
324
325 static void irq_sysfs_add(int irq, struct irq_desc *desc) {}
326
327 #endif /* CONFIG_SYSFS */
328
329 static RADIX_TREE(irq_desc_tree, GFP_KERNEL);
330
331 static void irq_insert_desc(unsigned int irq, struct irq_desc *desc)
332 {
333         radix_tree_insert(&irq_desc_tree, irq, desc);
334 }
335
336 struct irq_desc *irq_to_desc(unsigned int irq)
337 {
338         return radix_tree_lookup(&irq_desc_tree, irq);
339 }
340 EXPORT_SYMBOL(irq_to_desc);
341
342 static void delete_irq_desc(unsigned int irq)
343 {
344         radix_tree_delete(&irq_desc_tree, irq);
345 }
346
347 #ifdef CONFIG_SMP
348 static void free_masks(struct irq_desc *desc)
349 {
350 #ifdef CONFIG_GENERIC_PENDING_IRQ
351         free_cpumask_var(desc->pending_mask);
352 #endif
353         free_cpumask_var(desc->irq_common_data.affinity);
354 #ifdef CONFIG_GENERIC_IRQ_EFFECTIVE_AFF_MASK
355         free_cpumask_var(desc->irq_common_data.effective_affinity);
356 #endif
357 }
358 #else
359 static inline void free_masks(struct irq_desc *desc) { }
360 #endif
361
362 void irq_lock_sparse(void)
363 {
364         mutex_lock(&sparse_irq_lock);
365 }
366
367 void irq_unlock_sparse(void)
368 {
369         mutex_unlock(&sparse_irq_lock);
370 }
371
372 static struct irq_desc *alloc_desc(int irq, int node, unsigned int flags,
373                                    const struct cpumask *affinity,
374                                    struct module *owner)
375 {
376         struct irq_desc *desc;
377
378         desc = kzalloc_node(sizeof(*desc), GFP_KERNEL, node);
379         if (!desc)
380                 return NULL;
381         /* allocate based on nr_cpu_ids */
382         desc->kstat_irqs = alloc_percpu(unsigned int);
383         if (!desc->kstat_irqs)
384                 goto err_desc;
385
386         if (alloc_masks(desc, node))
387                 goto err_kstat;
388
389         raw_spin_lock_init(&desc->lock);
390         lockdep_set_class(&desc->lock, &irq_desc_lock_class);
391         mutex_init(&desc->request_mutex);
392         init_rcu_head(&desc->rcu);
393
394         desc_set_defaults(irq, desc, node, affinity, owner);
395         irqd_set(&desc->irq_data, flags);
396         kobject_init(&desc->kobj, &irq_kobj_type);
397
398         return desc;
399
400 err_kstat:
401         free_percpu(desc->kstat_irqs);
402 err_desc:
403         kfree(desc);
404         return NULL;
405 }
406
407 static void irq_kobj_release(struct kobject *kobj)
408 {
409         struct irq_desc *desc = container_of(kobj, struct irq_desc, kobj);
410
411         free_masks(desc);
412         free_percpu(desc->kstat_irqs);
413         kfree(desc);
414 }
415
416 static void delayed_free_desc(struct rcu_head *rhp)
417 {
418         struct irq_desc *desc = container_of(rhp, struct irq_desc, rcu);
419
420         kobject_put(&desc->kobj);
421 }
422
423 static void free_desc(unsigned int irq)
424 {
425         struct irq_desc *desc = irq_to_desc(irq);
426
427         irq_remove_debugfs_entry(desc);
428         unregister_irq_proc(irq, desc);
429
430         /*
431          * sparse_irq_lock protects also show_interrupts() and
432          * kstat_irq_usr(). Once we deleted the descriptor from the
433          * sparse tree we can free it. Access in proc will fail to
434          * lookup the descriptor.
435          *
436          * The sysfs entry must be serialized against a concurrent
437          * irq_sysfs_init() as well.
438          */
439         kobject_del(&desc->kobj);
440         delete_irq_desc(irq);
441
442         /*
443          * We free the descriptor, masks and stat fields via RCU. That
444          * allows demultiplex interrupts to do rcu based management of
445          * the child interrupts.
446          * This also allows us to use rcu in kstat_irqs_usr().
447          */
448         call_rcu(&desc->rcu, delayed_free_desc);
449 }
450
451 static int alloc_descs(unsigned int start, unsigned int cnt, int node,
452                        const struct irq_affinity_desc *affinity,
453                        struct module *owner)
454 {
455         struct irq_desc *desc;
456         int i;
457
458         /* Validate affinity mask(s) */
459         if (affinity) {
460                 for (i = 0; i < cnt; i++, i++) {
461                         if (cpumask_empty(&affinity[i].mask))
462                                 return -EINVAL;
463                 }
464         }
465
466         for (i = 0; i < cnt; i++) {
467                 const struct cpumask *mask = NULL;
468                 unsigned int flags = 0;
469
470                 if (affinity) {
471                         if (affinity->is_managed) {
472                                 flags = IRQD_AFFINITY_MANAGED |
473                                         IRQD_MANAGED_SHUTDOWN;
474                         }
475                         mask = &affinity->mask;
476                         node = cpu_to_node(cpumask_first(mask));
477                         affinity++;
478                 }
479
480                 desc = alloc_desc(start + i, node, flags, mask, owner);
481                 if (!desc)
482                         goto err;
483                 irq_insert_desc(start + i, desc);
484                 irq_sysfs_add(start + i, desc);
485                 irq_add_debugfs_entry(start + i, desc);
486         }
487         bitmap_set(allocated_irqs, start, cnt);
488         return start;
489
490 err:
491         for (i--; i >= 0; i--)
492                 free_desc(start + i);
493         return -ENOMEM;
494 }
495
496 static int irq_expand_nr_irqs(unsigned int nr)
497 {
498         if (nr > IRQ_BITMAP_BITS)
499                 return -ENOMEM;
500         nr_irqs = nr;
501         return 0;
502 }
503
504 int __init early_irq_init(void)
505 {
506         int i, initcnt, node = first_online_node;
507         struct irq_desc *desc;
508
509         init_irq_default_affinity();
510
511         /* Let arch update nr_irqs and return the nr of preallocated irqs */
512         initcnt = arch_probe_nr_irqs();
513         printk(KERN_INFO "NR_IRQS: %d, nr_irqs: %d, preallocated irqs: %d\n",
514                NR_IRQS, nr_irqs, initcnt);
515
516         if (WARN_ON(nr_irqs > IRQ_BITMAP_BITS))
517                 nr_irqs = IRQ_BITMAP_BITS;
518
519         if (WARN_ON(initcnt > IRQ_BITMAP_BITS))
520                 initcnt = IRQ_BITMAP_BITS;
521
522         if (initcnt > nr_irqs)
523                 nr_irqs = initcnt;
524
525         for (i = 0; i < initcnt; i++) {
526                 desc = alloc_desc(i, node, 0, NULL, NULL);
527                 set_bit(i, allocated_irqs);
528                 irq_insert_desc(i, desc);
529         }
530         return arch_early_irq_init();
531 }
532
533 #else /* !CONFIG_SPARSE_IRQ */
534
535 struct irq_desc irq_desc[NR_IRQS] __cacheline_aligned_in_smp = {
536         [0 ... NR_IRQS-1] = {
537                 .handle_irq     = handle_bad_irq,
538                 .depth          = 1,
539                 .lock           = __RAW_SPIN_LOCK_UNLOCKED(irq_desc->lock),
540         }
541 };
542
543 int __init early_irq_init(void)
544 {
545         int count, i, node = first_online_node;
546         struct irq_desc *desc;
547
548         init_irq_default_affinity();
549
550         printk(KERN_INFO "NR_IRQS: %d\n", NR_IRQS);
551
552         desc = irq_desc;
553         count = ARRAY_SIZE(irq_desc);
554
555         for (i = 0; i < count; i++) {
556                 desc[i].kstat_irqs = alloc_percpu(unsigned int);
557                 alloc_masks(&desc[i], node);
558                 raw_spin_lock_init(&desc[i].lock);
559                 lockdep_set_class(&desc[i].lock, &irq_desc_lock_class);
560                 desc_set_defaults(i, &desc[i], node, NULL, NULL);
561         }
562         return arch_early_irq_init();
563 }
564
565 struct irq_desc *irq_to_desc(unsigned int irq)
566 {
567         return (irq < NR_IRQS) ? irq_desc + irq : NULL;
568 }
569 EXPORT_SYMBOL(irq_to_desc);
570
571 static void free_desc(unsigned int irq)
572 {
573         struct irq_desc *desc = irq_to_desc(irq);
574         unsigned long flags;
575
576         raw_spin_lock_irqsave(&desc->lock, flags);
577         desc_set_defaults(irq, desc, irq_desc_get_node(desc), NULL, NULL);
578         raw_spin_unlock_irqrestore(&desc->lock, flags);
579 }
580
581 static inline int alloc_descs(unsigned int start, unsigned int cnt, int node,
582                               const struct irq_affinity_desc *affinity,
583                               struct module *owner)
584 {
585         u32 i;
586
587         for (i = 0; i < cnt; i++) {
588                 struct irq_desc *desc = irq_to_desc(start + i);
589
590                 desc->owner = owner;
591         }
592         bitmap_set(allocated_irqs, start, cnt);
593         return start;
594 }
595
596 static int irq_expand_nr_irqs(unsigned int nr)
597 {
598         return -ENOMEM;
599 }
600
601 void irq_mark_irq(unsigned int irq)
602 {
603         mutex_lock(&sparse_irq_lock);
604         bitmap_set(allocated_irqs, irq, 1);
605         mutex_unlock(&sparse_irq_lock);
606 }
607
608 #ifdef CONFIG_GENERIC_IRQ_LEGACY
609 void irq_init_desc(unsigned int irq)
610 {
611         free_desc(irq);
612 }
613 #endif
614
615 #endif /* !CONFIG_SPARSE_IRQ */
616
617 /**
618  * generic_handle_irq - Invoke the handler for a particular irq
619  * @irq:        The irq number to handle
620  *
621  */
622 int generic_handle_irq(unsigned int irq)
623 {
624         struct irq_desc *desc = irq_to_desc(irq);
625
626         if (!desc)
627                 return -EINVAL;
628         generic_handle_irq_desc(desc);
629         return 0;
630 }
631 EXPORT_SYMBOL_GPL(generic_handle_irq);
632
633 #ifdef CONFIG_HANDLE_DOMAIN_IRQ
634 /**
635  * __handle_domain_irq - Invoke the handler for a HW irq belonging to a domain
636  * @domain:     The domain where to perform the lookup
637  * @hwirq:      The HW irq number to convert to a logical one
638  * @lookup:     Whether to perform the domain lookup or not
639  * @regs:       Register file coming from the low-level handling code
640  *
641  * Returns:     0 on success, or -EINVAL if conversion has failed
642  */
643 int __handle_domain_irq(struct irq_domain *domain, unsigned int hwirq,
644                         bool lookup, struct pt_regs *regs)
645 {
646         struct pt_regs *old_regs = set_irq_regs(regs);
647         unsigned int irq = hwirq;
648         int ret = 0;
649
650         irq_enter();
651
652 #ifdef CONFIG_IRQ_DOMAIN
653         if (lookup)
654                 irq = irq_find_mapping(domain, hwirq);
655 #endif
656
657         /*
658          * Some hardware gives randomly wrong interrupts.  Rather
659          * than crashing, do something sensible.
660          */
661         if (unlikely(!irq || irq >= nr_irqs)) {
662                 ack_bad_irq(irq);
663                 ret = -EINVAL;
664         } else {
665                 generic_handle_irq(irq);
666         }
667
668         irq_exit();
669         set_irq_regs(old_regs);
670         return ret;
671 }
672 #endif
673
674 /* Dynamic interrupt handling */
675
676 /**
677  * irq_free_descs - free irq descriptors
678  * @from:       Start of descriptor range
679  * @cnt:        Number of consecutive irqs to free
680  */
681 void irq_free_descs(unsigned int from, unsigned int cnt)
682 {
683         int i;
684
685         if (from >= nr_irqs || (from + cnt) > nr_irqs)
686                 return;
687
688         mutex_lock(&sparse_irq_lock);
689         for (i = 0; i < cnt; i++)
690                 free_desc(from + i);
691
692         bitmap_clear(allocated_irqs, from, cnt);
693         mutex_unlock(&sparse_irq_lock);
694 }
695 EXPORT_SYMBOL_GPL(irq_free_descs);
696
697 /**
698  * irq_alloc_descs - allocate and initialize a range of irq descriptors
699  * @irq:        Allocate for specific irq number if irq >= 0
700  * @from:       Start the search from this irq number
701  * @cnt:        Number of consecutive irqs to allocate.
702  * @node:       Preferred node on which the irq descriptor should be allocated
703  * @owner:      Owning module (can be NULL)
704  * @affinity:   Optional pointer to an affinity mask array of size @cnt which
705  *              hints where the irq descriptors should be allocated and which
706  *              default affinities to use
707  *
708  * Returns the first irq number or error code
709  */
710 int __ref
711 __irq_alloc_descs(int irq, unsigned int from, unsigned int cnt, int node,
712                   struct module *owner, const struct irq_affinity_desc *affinity)
713 {
714         int start, ret;
715
716         if (!cnt)
717                 return -EINVAL;
718
719         if (irq >= 0) {
720                 if (from > irq)
721                         return -EINVAL;
722                 from = irq;
723         } else {
724                 /*
725                  * For interrupts which are freely allocated the
726                  * architecture can force a lower bound to the @from
727                  * argument. x86 uses this to exclude the GSI space.
728                  */
729                 from = arch_dynirq_lower_bound(from);
730         }
731
732         mutex_lock(&sparse_irq_lock);
733
734         start = bitmap_find_next_zero_area(allocated_irqs, IRQ_BITMAP_BITS,
735                                            from, cnt, 0);
736         ret = -EEXIST;
737         if (irq >=0 && start != irq)
738                 goto unlock;
739
740         if (start + cnt > nr_irqs) {
741                 ret = irq_expand_nr_irqs(start + cnt);
742                 if (ret)
743                         goto unlock;
744         }
745         ret = alloc_descs(start, cnt, node, affinity, owner);
746 unlock:
747         mutex_unlock(&sparse_irq_lock);
748         return ret;
749 }
750 EXPORT_SYMBOL_GPL(__irq_alloc_descs);
751
752 #ifdef CONFIG_GENERIC_IRQ_LEGACY_ALLOC_HWIRQ
753 /**
754  * irq_alloc_hwirqs - Allocate an irq descriptor and initialize the hardware
755  * @cnt:        number of interrupts to allocate
756  * @node:       node on which to allocate
757  *
758  * Returns an interrupt number > 0 or 0, if the allocation fails.
759  */
760 unsigned int irq_alloc_hwirqs(int cnt, int node)
761 {
762         int i, irq = __irq_alloc_descs(-1, 0, cnt, node, NULL, NULL);
763
764         if (irq < 0)
765                 return 0;
766
767         for (i = irq; cnt > 0; i++, cnt--) {
768                 if (arch_setup_hwirq(i, node))
769                         goto err;
770                 irq_clear_status_flags(i, _IRQ_NOREQUEST);
771         }
772         return irq;
773
774 err:
775         for (i--; i >= irq; i--) {
776                 irq_set_status_flags(i, _IRQ_NOREQUEST | _IRQ_NOPROBE);
777                 arch_teardown_hwirq(i);
778         }
779         irq_free_descs(irq, cnt);
780         return 0;
781 }
782 EXPORT_SYMBOL_GPL(irq_alloc_hwirqs);
783
784 /**
785  * irq_free_hwirqs - Free irq descriptor and cleanup the hardware
786  * @from:       Free from irq number
787  * @cnt:        number of interrupts to free
788  *
789  */
790 void irq_free_hwirqs(unsigned int from, int cnt)
791 {
792         int i, j;
793
794         for (i = from, j = cnt; j > 0; i++, j--) {
795                 irq_set_status_flags(i, _IRQ_NOREQUEST | _IRQ_NOPROBE);
796                 arch_teardown_hwirq(i);
797         }
798         irq_free_descs(from, cnt);
799 }
800 EXPORT_SYMBOL_GPL(irq_free_hwirqs);
801 #endif
802
803 /**
804  * irq_get_next_irq - get next allocated irq number
805  * @offset:     where to start the search
806  *
807  * Returns next irq number after offset or nr_irqs if none is found.
808  */
809 unsigned int irq_get_next_irq(unsigned int offset)
810 {
811         return find_next_bit(allocated_irqs, nr_irqs, offset);
812 }
813
814 struct irq_desc *
815 __irq_get_desc_lock(unsigned int irq, unsigned long *flags, bool bus,
816                     unsigned int check)
817 {
818         struct irq_desc *desc = irq_to_desc(irq);
819
820         if (desc) {
821                 if (check & _IRQ_DESC_CHECK) {
822                         if ((check & _IRQ_DESC_PERCPU) &&
823                             !irq_settings_is_per_cpu_devid(desc))
824                                 return NULL;
825
826                         if (!(check & _IRQ_DESC_PERCPU) &&
827                             irq_settings_is_per_cpu_devid(desc))
828                                 return NULL;
829                 }
830
831                 if (bus)
832                         chip_bus_lock(desc);
833                 raw_spin_lock_irqsave(&desc->lock, *flags);
834         }
835         return desc;
836 }
837
838 void __irq_put_desc_unlock(struct irq_desc *desc, unsigned long flags, bool bus)
839 {
840         raw_spin_unlock_irqrestore(&desc->lock, flags);
841         if (bus)
842                 chip_bus_sync_unlock(desc);
843 }
844
845 int irq_set_percpu_devid_partition(unsigned int irq,
846                                    const struct cpumask *affinity)
847 {
848         struct irq_desc *desc = irq_to_desc(irq);
849
850         if (!desc)
851                 return -EINVAL;
852
853         if (desc->percpu_enabled)
854                 return -EINVAL;
855
856         desc->percpu_enabled = kzalloc(sizeof(*desc->percpu_enabled), GFP_KERNEL);
857
858         if (!desc->percpu_enabled)
859                 return -ENOMEM;
860
861         if (affinity)
862                 desc->percpu_affinity = affinity;
863         else
864                 desc->percpu_affinity = cpu_possible_mask;
865
866         irq_set_percpu_devid_flags(irq);
867         return 0;
868 }
869
870 int irq_set_percpu_devid(unsigned int irq)
871 {
872         return irq_set_percpu_devid_partition(irq, NULL);
873 }
874
875 int irq_get_percpu_devid_partition(unsigned int irq, struct cpumask *affinity)
876 {
877         struct irq_desc *desc = irq_to_desc(irq);
878
879         if (!desc || !desc->percpu_enabled)
880                 return -EINVAL;
881
882         if (affinity)
883                 cpumask_copy(affinity, desc->percpu_affinity);
884
885         return 0;
886 }
887 EXPORT_SYMBOL_GPL(irq_get_percpu_devid_partition);
888
889 void kstat_incr_irq_this_cpu(unsigned int irq)
890 {
891         kstat_incr_irqs_this_cpu(irq_to_desc(irq));
892 }
893
894 /**
895  * kstat_irqs_cpu - Get the statistics for an interrupt on a cpu
896  * @irq:        The interrupt number
897  * @cpu:        The cpu number
898  *
899  * Returns the sum of interrupt counts on @cpu since boot for
900  * @irq. The caller must ensure that the interrupt is not removed
901  * concurrently.
902  */
903 unsigned int kstat_irqs_cpu(unsigned int irq, int cpu)
904 {
905         struct irq_desc *desc = irq_to_desc(irq);
906
907         return desc && desc->kstat_irqs ?
908                         *per_cpu_ptr(desc->kstat_irqs, cpu) : 0;
909 }
910
911 /**
912  * kstat_irqs - Get the statistics for an interrupt
913  * @irq:        The interrupt number
914  *
915  * Returns the sum of interrupt counts on all cpus since boot for
916  * @irq. The caller must ensure that the interrupt is not removed
917  * concurrently.
918  */
919 unsigned int kstat_irqs(unsigned int irq)
920 {
921         struct irq_desc *desc = irq_to_desc(irq);
922         int cpu;
923         unsigned int sum = 0;
924
925         if (!desc || !desc->kstat_irqs)
926                 return 0;
927         for_each_possible_cpu(cpu)
928                 sum += *per_cpu_ptr(desc->kstat_irqs, cpu);
929         return sum;
930 }
931
932 /**
933  * kstat_irqs_usr - Get the statistics for an interrupt
934  * @irq:        The interrupt number
935  *
936  * Returns the sum of interrupt counts on all cpus since boot for @irq.
937  * Contrary to kstat_irqs() this can be called from any context.
938  * It uses rcu since a concurrent removal of an interrupt descriptor is
939  * observing an rcu grace period before delayed_free_desc()/irq_kobj_release().
940  */
941 unsigned int kstat_irqs_usr(unsigned int irq)
942 {
943         unsigned int sum;
944
945         rcu_read_lock();
946         sum = kstat_irqs(irq);
947         rcu_read_unlock();
948         return sum;
949 }