genirq: Avoid summation loops for /proc/stat
[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->tot_count = 0;
123         desc->name = NULL;
124         desc->owner = owner;
125         for_each_possible_cpu(cpu)
126                 *per_cpu_ptr(desc->kstat_irqs, cpu) = 0;
127         desc_smp_init(desc, node, affinity);
128 }
129
130 int nr_irqs = NR_IRQS;
131 EXPORT_SYMBOL_GPL(nr_irqs);
132
133 static DEFINE_MUTEX(sparse_irq_lock);
134 static DECLARE_BITMAP(allocated_irqs, IRQ_BITMAP_BITS);
135
136 #ifdef CONFIG_SPARSE_IRQ
137
138 static void irq_kobj_release(struct kobject *kobj);
139
140 #ifdef CONFIG_SYSFS
141 static struct kobject *irq_kobj_base;
142
143 #define IRQ_ATTR_RO(_name) \
144 static struct kobj_attribute _name##_attr = __ATTR_RO(_name)
145
146 static ssize_t per_cpu_count_show(struct kobject *kobj,
147                                   struct kobj_attribute *attr, char *buf)
148 {
149         struct irq_desc *desc = container_of(kobj, struct irq_desc, kobj);
150         int cpu, irq = desc->irq_data.irq;
151         ssize_t ret = 0;
152         char *p = "";
153
154         for_each_possible_cpu(cpu) {
155                 unsigned int c = kstat_irqs_cpu(irq, cpu);
156
157                 ret += scnprintf(buf + ret, PAGE_SIZE - ret, "%s%u", p, c);
158                 p = ",";
159         }
160
161         ret += scnprintf(buf + ret, PAGE_SIZE - ret, "\n");
162         return ret;
163 }
164 IRQ_ATTR_RO(per_cpu_count);
165
166 static ssize_t chip_name_show(struct kobject *kobj,
167                               struct kobj_attribute *attr, char *buf)
168 {
169         struct irq_desc *desc = container_of(kobj, struct irq_desc, kobj);
170         ssize_t ret = 0;
171
172         raw_spin_lock_irq(&desc->lock);
173         if (desc->irq_data.chip && desc->irq_data.chip->name) {
174                 ret = scnprintf(buf, PAGE_SIZE, "%s\n",
175                                 desc->irq_data.chip->name);
176         }
177         raw_spin_unlock_irq(&desc->lock);
178
179         return ret;
180 }
181 IRQ_ATTR_RO(chip_name);
182
183 static ssize_t hwirq_show(struct kobject *kobj,
184                           struct kobj_attribute *attr, char *buf)
185 {
186         struct irq_desc *desc = container_of(kobj, struct irq_desc, kobj);
187         ssize_t ret = 0;
188
189         raw_spin_lock_irq(&desc->lock);
190         if (desc->irq_data.domain)
191                 ret = sprintf(buf, "%d\n", (int)desc->irq_data.hwirq);
192         raw_spin_unlock_irq(&desc->lock);
193
194         return ret;
195 }
196 IRQ_ATTR_RO(hwirq);
197
198 static ssize_t type_show(struct kobject *kobj,
199                          struct kobj_attribute *attr, char *buf)
200 {
201         struct irq_desc *desc = container_of(kobj, struct irq_desc, kobj);
202         ssize_t ret = 0;
203
204         raw_spin_lock_irq(&desc->lock);
205         ret = sprintf(buf, "%s\n",
206                       irqd_is_level_type(&desc->irq_data) ? "level" : "edge");
207         raw_spin_unlock_irq(&desc->lock);
208
209         return ret;
210
211 }
212 IRQ_ATTR_RO(type);
213
214 static ssize_t wakeup_show(struct kobject *kobj,
215                            struct kobj_attribute *attr, char *buf)
216 {
217         struct irq_desc *desc = container_of(kobj, struct irq_desc, kobj);
218         ssize_t ret = 0;
219
220         raw_spin_lock_irq(&desc->lock);
221         ret = sprintf(buf, "%s\n",
222                       irqd_is_wakeup_set(&desc->irq_data) ? "enabled" : "disabled");
223         raw_spin_unlock_irq(&desc->lock);
224
225         return ret;
226
227 }
228 IRQ_ATTR_RO(wakeup);
229
230 static ssize_t name_show(struct kobject *kobj,
231                          struct kobj_attribute *attr, char *buf)
232 {
233         struct irq_desc *desc = container_of(kobj, struct irq_desc, kobj);
234         ssize_t ret = 0;
235
236         raw_spin_lock_irq(&desc->lock);
237         if (desc->name)
238                 ret = scnprintf(buf, PAGE_SIZE, "%s\n", desc->name);
239         raw_spin_unlock_irq(&desc->lock);
240
241         return ret;
242 }
243 IRQ_ATTR_RO(name);
244
245 static ssize_t actions_show(struct kobject *kobj,
246                             struct kobj_attribute *attr, char *buf)
247 {
248         struct irq_desc *desc = container_of(kobj, struct irq_desc, kobj);
249         struct irqaction *action;
250         ssize_t ret = 0;
251         char *p = "";
252
253         raw_spin_lock_irq(&desc->lock);
254         for (action = desc->action; action != NULL; action = action->next) {
255                 ret += scnprintf(buf + ret, PAGE_SIZE - ret, "%s%s",
256                                  p, action->name);
257                 p = ",";
258         }
259         raw_spin_unlock_irq(&desc->lock);
260
261         if (ret)
262                 ret += scnprintf(buf + ret, PAGE_SIZE - ret, "\n");
263
264         return ret;
265 }
266 IRQ_ATTR_RO(actions);
267
268 static struct attribute *irq_attrs[] = {
269         &per_cpu_count_attr.attr,
270         &chip_name_attr.attr,
271         &hwirq_attr.attr,
272         &type_attr.attr,
273         &wakeup_attr.attr,
274         &name_attr.attr,
275         &actions_attr.attr,
276         NULL
277 };
278
279 static struct kobj_type irq_kobj_type = {
280         .release        = irq_kobj_release,
281         .sysfs_ops      = &kobj_sysfs_ops,
282         .default_attrs  = irq_attrs,
283 };
284
285 static void irq_sysfs_add(int irq, struct irq_desc *desc)
286 {
287         if (irq_kobj_base) {
288                 /*
289                  * Continue even in case of failure as this is nothing
290                  * crucial.
291                  */
292                 if (kobject_add(&desc->kobj, irq_kobj_base, "%d", irq))
293                         pr_warn("Failed to add kobject for irq %d\n", irq);
294         }
295 }
296
297 static int __init irq_sysfs_init(void)
298 {
299         struct irq_desc *desc;
300         int irq;
301
302         /* Prevent concurrent irq alloc/free */
303         irq_lock_sparse();
304
305         irq_kobj_base = kobject_create_and_add("irq", kernel_kobj);
306         if (!irq_kobj_base) {
307                 irq_unlock_sparse();
308                 return -ENOMEM;
309         }
310
311         /* Add the already allocated interrupts */
312         for_each_irq_desc(irq, desc)
313                 irq_sysfs_add(irq, desc);
314         irq_unlock_sparse();
315
316         return 0;
317 }
318 postcore_initcall(irq_sysfs_init);
319
320 #else /* !CONFIG_SYSFS */
321
322 static struct kobj_type irq_kobj_type = {
323         .release        = irq_kobj_release,
324 };
325
326 static void irq_sysfs_add(int irq, struct irq_desc *desc) {}
327
328 #endif /* CONFIG_SYSFS */
329
330 static RADIX_TREE(irq_desc_tree, GFP_KERNEL);
331
332 static void irq_insert_desc(unsigned int irq, struct irq_desc *desc)
333 {
334         radix_tree_insert(&irq_desc_tree, irq, desc);
335 }
336
337 struct irq_desc *irq_to_desc(unsigned int irq)
338 {
339         return radix_tree_lookup(&irq_desc_tree, irq);
340 }
341 EXPORT_SYMBOL(irq_to_desc);
342
343 static void delete_irq_desc(unsigned int irq)
344 {
345         radix_tree_delete(&irq_desc_tree, irq);
346 }
347
348 #ifdef CONFIG_SMP
349 static void free_masks(struct irq_desc *desc)
350 {
351 #ifdef CONFIG_GENERIC_PENDING_IRQ
352         free_cpumask_var(desc->pending_mask);
353 #endif
354         free_cpumask_var(desc->irq_common_data.affinity);
355 #ifdef CONFIG_GENERIC_IRQ_EFFECTIVE_AFF_MASK
356         free_cpumask_var(desc->irq_common_data.effective_affinity);
357 #endif
358 }
359 #else
360 static inline void free_masks(struct irq_desc *desc) { }
361 #endif
362
363 void irq_lock_sparse(void)
364 {
365         mutex_lock(&sparse_irq_lock);
366 }
367
368 void irq_unlock_sparse(void)
369 {
370         mutex_unlock(&sparse_irq_lock);
371 }
372
373 static struct irq_desc *alloc_desc(int irq, int node, unsigned int flags,
374                                    const struct cpumask *affinity,
375                                    struct module *owner)
376 {
377         struct irq_desc *desc;
378
379         desc = kzalloc_node(sizeof(*desc), GFP_KERNEL, node);
380         if (!desc)
381                 return NULL;
382         /* allocate based on nr_cpu_ids */
383         desc->kstat_irqs = alloc_percpu(unsigned int);
384         if (!desc->kstat_irqs)
385                 goto err_desc;
386
387         if (alloc_masks(desc, node))
388                 goto err_kstat;
389
390         raw_spin_lock_init(&desc->lock);
391         lockdep_set_class(&desc->lock, &irq_desc_lock_class);
392         mutex_init(&desc->request_mutex);
393         init_rcu_head(&desc->rcu);
394
395         desc_set_defaults(irq, desc, node, affinity, owner);
396         irqd_set(&desc->irq_data, flags);
397         kobject_init(&desc->kobj, &irq_kobj_type);
398
399         return desc;
400
401 err_kstat:
402         free_percpu(desc->kstat_irqs);
403 err_desc:
404         kfree(desc);
405         return NULL;
406 }
407
408 static void irq_kobj_release(struct kobject *kobj)
409 {
410         struct irq_desc *desc = container_of(kobj, struct irq_desc, kobj);
411
412         free_masks(desc);
413         free_percpu(desc->kstat_irqs);
414         kfree(desc);
415 }
416
417 static void delayed_free_desc(struct rcu_head *rhp)
418 {
419         struct irq_desc *desc = container_of(rhp, struct irq_desc, rcu);
420
421         kobject_put(&desc->kobj);
422 }
423
424 static void free_desc(unsigned int irq)
425 {
426         struct irq_desc *desc = irq_to_desc(irq);
427
428         irq_remove_debugfs_entry(desc);
429         unregister_irq_proc(irq, desc);
430
431         /*
432          * sparse_irq_lock protects also show_interrupts() and
433          * kstat_irq_usr(). Once we deleted the descriptor from the
434          * sparse tree we can free it. Access in proc will fail to
435          * lookup the descriptor.
436          *
437          * The sysfs entry must be serialized against a concurrent
438          * irq_sysfs_init() as well.
439          */
440         kobject_del(&desc->kobj);
441         delete_irq_desc(irq);
442
443         /*
444          * We free the descriptor, masks and stat fields via RCU. That
445          * allows demultiplex interrupts to do rcu based management of
446          * the child interrupts.
447          * This also allows us to use rcu in kstat_irqs_usr().
448          */
449         call_rcu(&desc->rcu, delayed_free_desc);
450 }
451
452 static int alloc_descs(unsigned int start, unsigned int cnt, int node,
453                        const struct irq_affinity_desc *affinity,
454                        struct module *owner)
455 {
456         struct irq_desc *desc;
457         int i;
458
459         /* Validate affinity mask(s) */
460         if (affinity) {
461                 for (i = 0; i < cnt; i++, i++) {
462                         if (cpumask_empty(&affinity[i].mask))
463                                 return -EINVAL;
464                 }
465         }
466
467         for (i = 0; i < cnt; i++) {
468                 const struct cpumask *mask = NULL;
469                 unsigned int flags = 0;
470
471                 if (affinity) {
472                         if (affinity->is_managed) {
473                                 flags = IRQD_AFFINITY_MANAGED |
474                                         IRQD_MANAGED_SHUTDOWN;
475                         }
476                         mask = &affinity->mask;
477                         node = cpu_to_node(cpumask_first(mask));
478                         affinity++;
479                 }
480
481                 desc = alloc_desc(start + i, node, flags, mask, owner);
482                 if (!desc)
483                         goto err;
484                 irq_insert_desc(start + i, desc);
485                 irq_sysfs_add(start + i, desc);
486                 irq_add_debugfs_entry(start + i, desc);
487         }
488         bitmap_set(allocated_irqs, start, cnt);
489         return start;
490
491 err:
492         for (i--; i >= 0; i--)
493                 free_desc(start + i);
494         return -ENOMEM;
495 }
496
497 static int irq_expand_nr_irqs(unsigned int nr)
498 {
499         if (nr > IRQ_BITMAP_BITS)
500                 return -ENOMEM;
501         nr_irqs = nr;
502         return 0;
503 }
504
505 int __init early_irq_init(void)
506 {
507         int i, initcnt, node = first_online_node;
508         struct irq_desc *desc;
509
510         init_irq_default_affinity();
511
512         /* Let arch update nr_irqs and return the nr of preallocated irqs */
513         initcnt = arch_probe_nr_irqs();
514         printk(KERN_INFO "NR_IRQS: %d, nr_irqs: %d, preallocated irqs: %d\n",
515                NR_IRQS, nr_irqs, initcnt);
516
517         if (WARN_ON(nr_irqs > IRQ_BITMAP_BITS))
518                 nr_irqs = IRQ_BITMAP_BITS;
519
520         if (WARN_ON(initcnt > IRQ_BITMAP_BITS))
521                 initcnt = IRQ_BITMAP_BITS;
522
523         if (initcnt > nr_irqs)
524                 nr_irqs = initcnt;
525
526         for (i = 0; i < initcnt; i++) {
527                 desc = alloc_desc(i, node, 0, NULL, NULL);
528                 set_bit(i, allocated_irqs);
529                 irq_insert_desc(i, desc);
530         }
531         return arch_early_irq_init();
532 }
533
534 #else /* !CONFIG_SPARSE_IRQ */
535
536 struct irq_desc irq_desc[NR_IRQS] __cacheline_aligned_in_smp = {
537         [0 ... NR_IRQS-1] = {
538                 .handle_irq     = handle_bad_irq,
539                 .depth          = 1,
540                 .lock           = __RAW_SPIN_LOCK_UNLOCKED(irq_desc->lock),
541         }
542 };
543
544 int __init early_irq_init(void)
545 {
546         int count, i, node = first_online_node;
547         struct irq_desc *desc;
548
549         init_irq_default_affinity();
550
551         printk(KERN_INFO "NR_IRQS: %d\n", NR_IRQS);
552
553         desc = irq_desc;
554         count = ARRAY_SIZE(irq_desc);
555
556         for (i = 0; i < count; i++) {
557                 desc[i].kstat_irqs = alloc_percpu(unsigned int);
558                 alloc_masks(&desc[i], node);
559                 raw_spin_lock_init(&desc[i].lock);
560                 lockdep_set_class(&desc[i].lock, &irq_desc_lock_class);
561                 desc_set_defaults(i, &desc[i], node, NULL, NULL);
562         }
563         return arch_early_irq_init();
564 }
565
566 struct irq_desc *irq_to_desc(unsigned int irq)
567 {
568         return (irq < NR_IRQS) ? irq_desc + irq : NULL;
569 }
570 EXPORT_SYMBOL(irq_to_desc);
571
572 static void free_desc(unsigned int irq)
573 {
574         struct irq_desc *desc = irq_to_desc(irq);
575         unsigned long flags;
576
577         raw_spin_lock_irqsave(&desc->lock, flags);
578         desc_set_defaults(irq, desc, irq_desc_get_node(desc), NULL, NULL);
579         raw_spin_unlock_irqrestore(&desc->lock, flags);
580 }
581
582 static inline int alloc_descs(unsigned int start, unsigned int cnt, int node,
583                               const struct irq_affinity_desc *affinity,
584                               struct module *owner)
585 {
586         u32 i;
587
588         for (i = 0; i < cnt; i++) {
589                 struct irq_desc *desc = irq_to_desc(start + i);
590
591                 desc->owner = owner;
592         }
593         bitmap_set(allocated_irqs, start, cnt);
594         return start;
595 }
596
597 static int irq_expand_nr_irqs(unsigned int nr)
598 {
599         return -ENOMEM;
600 }
601
602 void irq_mark_irq(unsigned int irq)
603 {
604         mutex_lock(&sparse_irq_lock);
605         bitmap_set(allocated_irqs, irq, 1);
606         mutex_unlock(&sparse_irq_lock);
607 }
608
609 #ifdef CONFIG_GENERIC_IRQ_LEGACY
610 void irq_init_desc(unsigned int irq)
611 {
612         free_desc(irq);
613 }
614 #endif
615
616 #endif /* !CONFIG_SPARSE_IRQ */
617
618 /**
619  * generic_handle_irq - Invoke the handler for a particular irq
620  * @irq:        The irq number to handle
621  *
622  */
623 int generic_handle_irq(unsigned int irq)
624 {
625         struct irq_desc *desc = irq_to_desc(irq);
626
627         if (!desc)
628                 return -EINVAL;
629         generic_handle_irq_desc(desc);
630         return 0;
631 }
632 EXPORT_SYMBOL_GPL(generic_handle_irq);
633
634 #ifdef CONFIG_HANDLE_DOMAIN_IRQ
635 /**
636  * __handle_domain_irq - Invoke the handler for a HW irq belonging to a domain
637  * @domain:     The domain where to perform the lookup
638  * @hwirq:      The HW irq number to convert to a logical one
639  * @lookup:     Whether to perform the domain lookup or not
640  * @regs:       Register file coming from the low-level handling code
641  *
642  * Returns:     0 on success, or -EINVAL if conversion has failed
643  */
644 int __handle_domain_irq(struct irq_domain *domain, unsigned int hwirq,
645                         bool lookup, struct pt_regs *regs)
646 {
647         struct pt_regs *old_regs = set_irq_regs(regs);
648         unsigned int irq = hwirq;
649         int ret = 0;
650
651         irq_enter();
652
653 #ifdef CONFIG_IRQ_DOMAIN
654         if (lookup)
655                 irq = irq_find_mapping(domain, hwirq);
656 #endif
657
658         /*
659          * Some hardware gives randomly wrong interrupts.  Rather
660          * than crashing, do something sensible.
661          */
662         if (unlikely(!irq || irq >= nr_irqs)) {
663                 ack_bad_irq(irq);
664                 ret = -EINVAL;
665         } else {
666                 generic_handle_irq(irq);
667         }
668
669         irq_exit();
670         set_irq_regs(old_regs);
671         return ret;
672 }
673 #endif
674
675 /* Dynamic interrupt handling */
676
677 /**
678  * irq_free_descs - free irq descriptors
679  * @from:       Start of descriptor range
680  * @cnt:        Number of consecutive irqs to free
681  */
682 void irq_free_descs(unsigned int from, unsigned int cnt)
683 {
684         int i;
685
686         if (from >= nr_irqs || (from + cnt) > nr_irqs)
687                 return;
688
689         mutex_lock(&sparse_irq_lock);
690         for (i = 0; i < cnt; i++)
691                 free_desc(from + i);
692
693         bitmap_clear(allocated_irqs, from, cnt);
694         mutex_unlock(&sparse_irq_lock);
695 }
696 EXPORT_SYMBOL_GPL(irq_free_descs);
697
698 /**
699  * irq_alloc_descs - allocate and initialize a range of irq descriptors
700  * @irq:        Allocate for specific irq number if irq >= 0
701  * @from:       Start the search from this irq number
702  * @cnt:        Number of consecutive irqs to allocate.
703  * @node:       Preferred node on which the irq descriptor should be allocated
704  * @owner:      Owning module (can be NULL)
705  * @affinity:   Optional pointer to an affinity mask array of size @cnt which
706  *              hints where the irq descriptors should be allocated and which
707  *              default affinities to use
708  *
709  * Returns the first irq number or error code
710  */
711 int __ref
712 __irq_alloc_descs(int irq, unsigned int from, unsigned int cnt, int node,
713                   struct module *owner, const struct irq_affinity_desc *affinity)
714 {
715         int start, ret;
716
717         if (!cnt)
718                 return -EINVAL;
719
720         if (irq >= 0) {
721                 if (from > irq)
722                         return -EINVAL;
723                 from = irq;
724         } else {
725                 /*
726                  * For interrupts which are freely allocated the
727                  * architecture can force a lower bound to the @from
728                  * argument. x86 uses this to exclude the GSI space.
729                  */
730                 from = arch_dynirq_lower_bound(from);
731         }
732
733         mutex_lock(&sparse_irq_lock);
734
735         start = bitmap_find_next_zero_area(allocated_irqs, IRQ_BITMAP_BITS,
736                                            from, cnt, 0);
737         ret = -EEXIST;
738         if (irq >=0 && start != irq)
739                 goto unlock;
740
741         if (start + cnt > nr_irqs) {
742                 ret = irq_expand_nr_irqs(start + cnt);
743                 if (ret)
744                         goto unlock;
745         }
746         ret = alloc_descs(start, cnt, node, affinity, owner);
747 unlock:
748         mutex_unlock(&sparse_irq_lock);
749         return ret;
750 }
751 EXPORT_SYMBOL_GPL(__irq_alloc_descs);
752
753 #ifdef CONFIG_GENERIC_IRQ_LEGACY_ALLOC_HWIRQ
754 /**
755  * irq_alloc_hwirqs - Allocate an irq descriptor and initialize the hardware
756  * @cnt:        number of interrupts to allocate
757  * @node:       node on which to allocate
758  *
759  * Returns an interrupt number > 0 or 0, if the allocation fails.
760  */
761 unsigned int irq_alloc_hwirqs(int cnt, int node)
762 {
763         int i, irq = __irq_alloc_descs(-1, 0, cnt, node, NULL, NULL);
764
765         if (irq < 0)
766                 return 0;
767
768         for (i = irq; cnt > 0; i++, cnt--) {
769                 if (arch_setup_hwirq(i, node))
770                         goto err;
771                 irq_clear_status_flags(i, _IRQ_NOREQUEST);
772         }
773         return irq;
774
775 err:
776         for (i--; i >= irq; i--) {
777                 irq_set_status_flags(i, _IRQ_NOREQUEST | _IRQ_NOPROBE);
778                 arch_teardown_hwirq(i);
779         }
780         irq_free_descs(irq, cnt);
781         return 0;
782 }
783 EXPORT_SYMBOL_GPL(irq_alloc_hwirqs);
784
785 /**
786  * irq_free_hwirqs - Free irq descriptor and cleanup the hardware
787  * @from:       Free from irq number
788  * @cnt:        number of interrupts to free
789  *
790  */
791 void irq_free_hwirqs(unsigned int from, int cnt)
792 {
793         int i, j;
794
795         for (i = from, j = cnt; j > 0; i++, j--) {
796                 irq_set_status_flags(i, _IRQ_NOREQUEST | _IRQ_NOPROBE);
797                 arch_teardown_hwirq(i);
798         }
799         irq_free_descs(from, cnt);
800 }
801 EXPORT_SYMBOL_GPL(irq_free_hwirqs);
802 #endif
803
804 /**
805  * irq_get_next_irq - get next allocated irq number
806  * @offset:     where to start the search
807  *
808  * Returns next irq number after offset or nr_irqs if none is found.
809  */
810 unsigned int irq_get_next_irq(unsigned int offset)
811 {
812         return find_next_bit(allocated_irqs, nr_irqs, offset);
813 }
814
815 struct irq_desc *
816 __irq_get_desc_lock(unsigned int irq, unsigned long *flags, bool bus,
817                     unsigned int check)
818 {
819         struct irq_desc *desc = irq_to_desc(irq);
820
821         if (desc) {
822                 if (check & _IRQ_DESC_CHECK) {
823                         if ((check & _IRQ_DESC_PERCPU) &&
824                             !irq_settings_is_per_cpu_devid(desc))
825                                 return NULL;
826
827                         if (!(check & _IRQ_DESC_PERCPU) &&
828                             irq_settings_is_per_cpu_devid(desc))
829                                 return NULL;
830                 }
831
832                 if (bus)
833                         chip_bus_lock(desc);
834                 raw_spin_lock_irqsave(&desc->lock, *flags);
835         }
836         return desc;
837 }
838
839 void __irq_put_desc_unlock(struct irq_desc *desc, unsigned long flags, bool bus)
840 {
841         raw_spin_unlock_irqrestore(&desc->lock, flags);
842         if (bus)
843                 chip_bus_sync_unlock(desc);
844 }
845
846 int irq_set_percpu_devid_partition(unsigned int irq,
847                                    const struct cpumask *affinity)
848 {
849         struct irq_desc *desc = irq_to_desc(irq);
850
851         if (!desc)
852                 return -EINVAL;
853
854         if (desc->percpu_enabled)
855                 return -EINVAL;
856
857         desc->percpu_enabled = kzalloc(sizeof(*desc->percpu_enabled), GFP_KERNEL);
858
859         if (!desc->percpu_enabled)
860                 return -ENOMEM;
861
862         if (affinity)
863                 desc->percpu_affinity = affinity;
864         else
865                 desc->percpu_affinity = cpu_possible_mask;
866
867         irq_set_percpu_devid_flags(irq);
868         return 0;
869 }
870
871 int irq_set_percpu_devid(unsigned int irq)
872 {
873         return irq_set_percpu_devid_partition(irq, NULL);
874 }
875
876 int irq_get_percpu_devid_partition(unsigned int irq, struct cpumask *affinity)
877 {
878         struct irq_desc *desc = irq_to_desc(irq);
879
880         if (!desc || !desc->percpu_enabled)
881                 return -EINVAL;
882
883         if (affinity)
884                 cpumask_copy(affinity, desc->percpu_affinity);
885
886         return 0;
887 }
888 EXPORT_SYMBOL_GPL(irq_get_percpu_devid_partition);
889
890 void kstat_incr_irq_this_cpu(unsigned int irq)
891 {
892         kstat_incr_irqs_this_cpu(irq_to_desc(irq));
893 }
894
895 /**
896  * kstat_irqs_cpu - Get the statistics for an interrupt on a cpu
897  * @irq:        The interrupt number
898  * @cpu:        The cpu number
899  *
900  * Returns the sum of interrupt counts on @cpu since boot for
901  * @irq. The caller must ensure that the interrupt is not removed
902  * concurrently.
903  */
904 unsigned int kstat_irqs_cpu(unsigned int irq, int cpu)
905 {
906         struct irq_desc *desc = irq_to_desc(irq);
907
908         return desc && desc->kstat_irqs ?
909                         *per_cpu_ptr(desc->kstat_irqs, cpu) : 0;
910 }
911
912 /**
913  * kstat_irqs - Get the statistics for an interrupt
914  * @irq:        The interrupt number
915  *
916  * Returns the sum of interrupt counts on all cpus since boot for
917  * @irq. The caller must ensure that the interrupt is not removed
918  * concurrently.
919  */
920 unsigned int kstat_irqs(unsigned int irq)
921 {
922         struct irq_desc *desc = irq_to_desc(irq);
923         unsigned int sum = 0;
924         int cpu;
925
926         if (!desc || !desc->kstat_irqs)
927                 return 0;
928         if (!irq_settings_is_per_cpu_devid(desc) &&
929             !irq_settings_is_per_cpu(desc))
930             return desc->tot_count;
931
932         for_each_possible_cpu(cpu)
933                 sum += *per_cpu_ptr(desc->kstat_irqs, cpu);
934         return sum;
935 }
936
937 /**
938  * kstat_irqs_usr - Get the statistics for an interrupt
939  * @irq:        The interrupt number
940  *
941  * Returns the sum of interrupt counts on all cpus since boot for @irq.
942  * Contrary to kstat_irqs() this can be called from any context.
943  * It uses rcu since a concurrent removal of an interrupt descriptor is
944  * observing an rcu grace period before delayed_free_desc()/irq_kobj_release().
945  */
946 unsigned int kstat_irqs_usr(unsigned int irq)
947 {
948         unsigned int sum;
949
950         rcu_read_lock();
951         sum = kstat_irqs(irq);
952         rcu_read_unlock();
953         return sum;
954 }