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