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Linux/kernel/irq/irqdesc.c

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  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 commandline 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         ssize_t ret = 0;
151         char *p = "";
152         int cpu;
153 
154         for_each_possible_cpu(cpu) {
155                 unsigned int c = irq_desc_kstat_cpu(desc, cpu);
156 
157                 ret += scnprintf(buf + ret, PAGE_SIZE - ret, "%s%u", p, c);
158                 p = ",";
159         }
160 
161         ret += scnprintf(buf + ret, PAGE_SIZE - ret, "\n");
162         return ret;
163 }
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 ATTRIBUTE_GROUPS(irq);
279 
280 static struct kobj_type irq_kobj_type = {
281         .release        = irq_kobj_release,
282         .sysfs_ops      = &kobj_sysfs_ops,
283         .default_groups = irq_groups,
284 };
285 
286 static void irq_sysfs_add(int irq, struct irq_desc *desc)
287 {
288         if (irq_kobj_base) {
289                 /*
290                  * Continue even in case of failure as this is nothing
291                  * crucial.
292                  */
293                 if (kobject_add(&desc->kobj, irq_kobj_base, "%d", irq))
294                         pr_warn("Failed to add kobject for irq %d\n", irq);
295         }
296 }
297 
298 static void irq_sysfs_del(struct irq_desc *desc)
299 {
300         /*
301          * If irq_sysfs_init() has not yet been invoked (early boot), then
302          * irq_kobj_base is NULL and the descriptor was never added.
303          * kobject_del() complains about a object with no parent, so make
304          * it conditional.
305          */
306         if (irq_kobj_base)
307                 kobject_del(&desc->kobj);
308 }
309 
310 static int __init irq_sysfs_init(void)
311 {
312         struct irq_desc *desc;
313         int irq;
314 
315         /* Prevent concurrent irq alloc/free */
316         irq_lock_sparse();
317 
318         irq_kobj_base = kobject_create_and_add("irq", kernel_kobj);
319         if (!irq_kobj_base) {
320                 irq_unlock_sparse();
321                 return -ENOMEM;
322         }
323 
324         /* Add the already allocated interrupts */
325         for_each_irq_desc(irq, desc)
326                 irq_sysfs_add(irq, desc);
327         irq_unlock_sparse();
328 
329         return 0;
330 }
331 postcore_initcall(irq_sysfs_init);
332 
333 #else /* !CONFIG_SYSFS */
334 
335 static struct kobj_type irq_kobj_type = {
336         .release        = irq_kobj_release,
337 };
338 
339 static void irq_sysfs_add(int irq, struct irq_desc *desc) {}
340 static void irq_sysfs_del(struct irq_desc *desc) {}
341 
342 #endif /* CONFIG_SYSFS */
343 
344 static RADIX_TREE(irq_desc_tree, GFP_KERNEL);
345 
346 static void irq_insert_desc(unsigned int irq, struct irq_desc *desc)
347 {
348         radix_tree_insert(&irq_desc_tree, irq, desc);
349 }
350 
351 struct irq_desc *irq_to_desc(unsigned int irq)
352 {
353         return radix_tree_lookup(&irq_desc_tree, irq);
354 }
355 #ifdef CONFIG_KVM_BOOK3S_64_HV_MODULE
356 EXPORT_SYMBOL_GPL(irq_to_desc);
357 #endif
358 
359 static void delete_irq_desc(unsigned int irq)
360 {
361         radix_tree_delete(&irq_desc_tree, irq);
362 }
363 
364 #ifdef CONFIG_SMP
365 static void free_masks(struct irq_desc *desc)
366 {
367 #ifdef CONFIG_GENERIC_PENDING_IRQ
368         free_cpumask_var(desc->pending_mask);
369 #endif
370         free_cpumask_var(desc->irq_common_data.affinity);
371 #ifdef CONFIG_GENERIC_IRQ_EFFECTIVE_AFF_MASK
372         free_cpumask_var(desc->irq_common_data.effective_affinity);
373 #endif
374 }
375 #else
376 static inline void free_masks(struct irq_desc *desc) { }
377 #endif
378 
379 void irq_lock_sparse(void)
380 {
381         mutex_lock(&sparse_irq_lock);
382 }
383 
384 void irq_unlock_sparse(void)
385 {
386         mutex_unlock(&sparse_irq_lock);
387 }
388 
389 static struct irq_desc *alloc_desc(int irq, int node, unsigned int flags,
390                                    const struct cpumask *affinity,
391                                    struct module *owner)
392 {
393         struct irq_desc *desc;
394 
395         desc = kzalloc_node(sizeof(*desc), GFP_KERNEL, node);
396         if (!desc)
397                 return NULL;
398         /* allocate based on nr_cpu_ids */
399         desc->kstat_irqs = alloc_percpu(unsigned int);
400         if (!desc->kstat_irqs)
401                 goto err_desc;
402 
403         if (alloc_masks(desc, node))
404                 goto err_kstat;
405 
406         raw_spin_lock_init(&desc->lock);
407         lockdep_set_class(&desc->lock, &irq_desc_lock_class);
408         mutex_init(&desc->request_mutex);
409         init_rcu_head(&desc->rcu);
410 
411         desc_set_defaults(irq, desc, node, affinity, owner);
412         irqd_set(&desc->irq_data, flags);
413         kobject_init(&desc->kobj, &irq_kobj_type);
414 
415         return desc;
416 
417 err_kstat:
418         free_percpu(desc->kstat_irqs);
419 err_desc:
420         kfree(desc);
421         return NULL;
422 }
423 
424 static void irq_kobj_release(struct kobject *kobj)
425 {
426         struct irq_desc *desc = container_of(kobj, struct irq_desc, kobj);
427 
428         free_masks(desc);
429         free_percpu(desc->kstat_irqs);
430         kfree(desc);
431 }
432 
433 static void delayed_free_desc(struct rcu_head *rhp)
434 {
435         struct irq_desc *desc = container_of(rhp, struct irq_desc, rcu);
436 
437         kobject_put(&desc->kobj);
438 }
439 
440 static void free_desc(unsigned int irq)
441 {
442         struct irq_desc *desc = irq_to_desc(irq);
443 
444         irq_remove_debugfs_entry(desc);
445         unregister_irq_proc(irq, desc);
446 
447         /*
448          * sparse_irq_lock protects also show_interrupts() and
449          * kstat_irq_usr(). Once we deleted the descriptor from the
450          * sparse tree we can free it. Access in proc will fail to
451          * lookup the descriptor.
452          *
453          * The sysfs entry must be serialized against a concurrent
454          * irq_sysfs_init() as well.
455          */
456         irq_sysfs_del(desc);
457         delete_irq_desc(irq);
458 
459         /*
460          * We free the descriptor, masks and stat fields via RCU. That
461          * allows demultiplex interrupts to do rcu based management of
462          * the child interrupts.
463          * This also allows us to use rcu in kstat_irqs_usr().
464          */
465         call_rcu(&desc->rcu, delayed_free_desc);
466 }
467 
468 static int alloc_descs(unsigned int start, unsigned int cnt, int node,
469                        const struct irq_affinity_desc *affinity,
470                        struct module *owner)
471 {
472         struct irq_desc *desc;
473         int i;
474 
475         /* Validate affinity mask(s) */
476         if (affinity) {
477                 for (i = 0; i < cnt; i++) {
478                         if (cpumask_empty(&affinity[i].mask))
479                                 return -EINVAL;
480                 }
481         }
482 
483         for (i = 0; i < cnt; i++) {
484                 const struct cpumask *mask = NULL;
485                 unsigned int flags = 0;
486 
487                 if (affinity) {
488                         if (affinity->is_managed) {
489                                 flags = IRQD_AFFINITY_MANAGED |
490                                         IRQD_MANAGED_SHUTDOWN;
491                         }
492                         mask = &affinity->mask;
493                         node = cpu_to_node(cpumask_first(mask));
494                         affinity++;
495                 }
496 
497                 desc = alloc_desc(start + i, node, flags, mask, owner);
498                 if (!desc)
499                         goto err;
500                 irq_insert_desc(start + i, desc);
501                 irq_sysfs_add(start + i, desc);
502                 irq_add_debugfs_entry(start + i, desc);
503         }
504         bitmap_set(allocated_irqs, start, cnt);
505         return start;
506 
507 err:
508         for (i--; i >= 0; i--)
509                 free_desc(start + i);
510         return -ENOMEM;
511 }
512 
513 static int irq_expand_nr_irqs(unsigned int nr)
514 {
515         if (nr > IRQ_BITMAP_BITS)
516                 return -ENOMEM;
517         nr_irqs = nr;
518         return 0;
519 }
520 
521 int __init early_irq_init(void)
522 {
523         int i, initcnt, node = first_online_node;
524         struct irq_desc *desc;
525 
526         init_irq_default_affinity();
527 
528         /* Let arch update nr_irqs and return the nr of preallocated irqs */
529         initcnt = arch_probe_nr_irqs();
530         printk(KERN_INFO "NR_IRQS: %d, nr_irqs: %d, preallocated irqs: %d\n",
531                NR_IRQS, nr_irqs, initcnt);
532 
533         if (WARN_ON(nr_irqs > IRQ_BITMAP_BITS))
534                 nr_irqs = IRQ_BITMAP_BITS;
535 
536         if (WARN_ON(initcnt > IRQ_BITMAP_BITS))
537                 initcnt = IRQ_BITMAP_BITS;
538 
539         if (initcnt > nr_irqs)
540                 nr_irqs = initcnt;
541 
542         for (i = 0; i < initcnt; i++) {
543                 desc = alloc_desc(i, node, 0, NULL, NULL);
544                 set_bit(i, allocated_irqs);
545                 irq_insert_desc(i, desc);
546         }
547         return arch_early_irq_init();
548 }
549 
550 #else /* !CONFIG_SPARSE_IRQ */
551 
552 struct irq_desc irq_desc[NR_IRQS] __cacheline_aligned_in_smp = {
553         [0 ... NR_IRQS-1] = {
554                 .handle_irq     = handle_bad_irq,
555                 .depth          = 1,
556                 .lock           = __RAW_SPIN_LOCK_UNLOCKED(irq_desc->lock),
557         }
558 };
559 
560 int __init early_irq_init(void)
561 {
562         int count, i, node = first_online_node;
563         struct irq_desc *desc;
564 
565         init_irq_default_affinity();
566 
567         printk(KERN_INFO "NR_IRQS: %d\n", NR_IRQS);
568 
569         desc = irq_desc;
570         count = ARRAY_SIZE(irq_desc);
571 
572         for (i = 0; i < count; i++) {
573                 desc[i].kstat_irqs = alloc_percpu(unsigned int);
574                 alloc_masks(&desc[i], node);
575                 raw_spin_lock_init(&desc[i].lock);
576                 lockdep_set_class(&desc[i].lock, &irq_desc_lock_class);
577                 mutex_init(&desc[i].request_mutex);
578                 desc_set_defaults(i, &desc[i], node, NULL, NULL);
579         }
580         return arch_early_irq_init();
581 }
582 
583 struct irq_desc *irq_to_desc(unsigned int irq)
584 {
585         return (irq < NR_IRQS) ? irq_desc + irq : NULL;
586 }
587 EXPORT_SYMBOL(irq_to_desc);
588 
589 static void free_desc(unsigned int irq)
590 {
591         struct irq_desc *desc = irq_to_desc(irq);
592         unsigned long flags;
593 
594         raw_spin_lock_irqsave(&desc->lock, flags);
595         desc_set_defaults(irq, desc, irq_desc_get_node(desc), NULL, NULL);
596         raw_spin_unlock_irqrestore(&desc->lock, flags);
597 }
598 
599 static inline int alloc_descs(unsigned int start, unsigned int cnt, int node,
600                               const struct irq_affinity_desc *affinity,
601                               struct module *owner)
602 {
603         u32 i;
604 
605         for (i = 0; i < cnt; i++) {
606                 struct irq_desc *desc = irq_to_desc(start + i);
607 
608                 desc->owner = owner;
609         }
610         bitmap_set(allocated_irqs, start, cnt);
611         return start;
612 }
613 
614 static int irq_expand_nr_irqs(unsigned int nr)
615 {
616         return -ENOMEM;
617 }
618 
619 void irq_mark_irq(unsigned int irq)
620 {
621         mutex_lock(&sparse_irq_lock);
622         bitmap_set(allocated_irqs, irq, 1);
623         mutex_unlock(&sparse_irq_lock);
624 }
625 
626 #ifdef CONFIG_GENERIC_IRQ_LEGACY
627 void irq_init_desc(unsigned int irq)
628 {
629         free_desc(irq);
630 }
631 #endif
632 
633 #endif /* !CONFIG_SPARSE_IRQ */
634 
635 int handle_irq_desc(struct irq_desc *desc)
636 {
637         struct irq_data *data;
638 
639         if (!desc)
640                 return -EINVAL;
641 
642         data = irq_desc_get_irq_data(desc);
643         if (WARN_ON_ONCE(!in_irq() && handle_enforce_irqctx(data)))
644                 return -EPERM;
645 
646         generic_handle_irq_desc(desc);
647         return 0;
648 }
649 EXPORT_SYMBOL_GPL(handle_irq_desc);
650 
651 /**
652  * generic_handle_irq - Invoke the handler for a particular irq
653  * @irq:        The irq number to handle
654  *
655  */
656 int generic_handle_irq(unsigned int irq)
657 {
658         return handle_irq_desc(irq_to_desc(irq));
659 }
660 EXPORT_SYMBOL_GPL(generic_handle_irq);
661 
662 #ifdef CONFIG_IRQ_DOMAIN
663 /**
664  * generic_handle_domain_irq - Invoke the handler for a HW irq belonging
665  *                             to a domain, usually for a non-root interrupt
666  *                             controller
667  * @domain:     The domain where to perform the lookup
668  * @hwirq:      The HW irq number to convert to a logical one
669  *
670  * Returns:     0 on success, or -EINVAL if conversion has failed
671  *
672  */
673 int generic_handle_domain_irq(struct irq_domain *domain, unsigned int hwirq)
674 {
675         return handle_irq_desc(irq_resolve_mapping(domain, hwirq));
676 }
677 EXPORT_SYMBOL_GPL(generic_handle_domain_irq);
678 
679 #ifdef CONFIG_HANDLE_DOMAIN_IRQ
680 /**
681  * handle_domain_irq - Invoke the handler for a HW irq belonging to a domain,
682  *                     usually for a root interrupt controller
683  * @domain:     The domain where to perform the lookup
684  * @hwirq:      The HW irq number to convert to a logical one
685  * @regs:       Register file coming from the low-level handling code
686  *
687  * Returns:     0 on success, or -EINVAL if conversion has failed
688  */
689 int handle_domain_irq(struct irq_domain *domain,
690                       unsigned int hwirq, struct pt_regs *regs)
691 {
692         struct pt_regs *old_regs = set_irq_regs(regs);
693         struct irq_desc *desc;
694         int ret = 0;
695 
696         irq_enter();
697 
698         /* The irqdomain code provides boundary checks */
699         desc = irq_resolve_mapping(domain, hwirq);
700         if (likely(desc))
701                 handle_irq_desc(desc);
702         else
703                 ret = -EINVAL;
704 
705         irq_exit();
706         set_irq_regs(old_regs);
707         return ret;
708 }
709 
710 /**
711  * handle_domain_nmi - Invoke the handler for a HW irq belonging to a domain
712  * @domain:     The domain where to perform the lookup
713  * @hwirq:      The HW irq number to convert to a logical one
714  * @regs:       Register file coming from the low-level handling code
715  *
716  *              This function must be called from an NMI context.
717  *
718  * Returns:     0 on success, or -EINVAL if conversion has failed
719  */
720 int handle_domain_nmi(struct irq_domain *domain, unsigned int hwirq,
721                       struct pt_regs *regs)
722 {
723         struct pt_regs *old_regs = set_irq_regs(regs);
724         struct irq_desc *desc;
725         int ret = 0;
726 
727         /*
728          * NMI context needs to be setup earlier in order to deal with tracing.
729          */
730         WARN_ON(!in_nmi());
731 
732         desc = irq_resolve_mapping(domain, hwirq);
733 
734         /*
735          * ack_bad_irq is not NMI-safe, just report
736          * an invalid interrupt.
737          */
738         if (likely(desc))
739                 handle_irq_desc(desc);
740         else
741                 ret = -EINVAL;
742 
743         set_irq_regs(old_regs);
744         return ret;
745 }
746 #endif
747 #endif
748 
749 /* Dynamic interrupt handling */
750 
751 /**
752  * irq_free_descs - free irq descriptors
753  * @from:       Start of descriptor range
754  * @cnt:        Number of consecutive irqs to free
755  */
756 void irq_free_descs(unsigned int from, unsigned int cnt)
757 {
758         int i;
759 
760         if (from >= nr_irqs || (from + cnt) > nr_irqs)
761                 return;
762 
763         mutex_lock(&sparse_irq_lock);
764         for (i = 0; i < cnt; i++)
765                 free_desc(from + i);
766 
767         bitmap_clear(allocated_irqs, from, cnt);
768         mutex_unlock(&sparse_irq_lock);
769 }
770 EXPORT_SYMBOL_GPL(irq_free_descs);
771 
772 /**
773  * __irq_alloc_descs - allocate and initialize a range of irq descriptors
774  * @irq:        Allocate for specific irq number if irq >= 0
775  * @from:       Start the search from this irq number
776  * @cnt:        Number of consecutive irqs to allocate.
777  * @node:       Preferred node on which the irq descriptor should be allocated
778  * @owner:      Owning module (can be NULL)
779  * @affinity:   Optional pointer to an affinity mask array of size @cnt which
780  *              hints where the irq descriptors should be allocated and which
781  *              default affinities to use
782  *
783  * Returns the first irq number or error code
784  */
785 int __ref
786 __irq_alloc_descs(int irq, unsigned int from, unsigned int cnt, int node,
787                   struct module *owner, const struct irq_affinity_desc *affinity)
788 {
789         int start, ret;
790 
791         if (!cnt)
792                 return -EINVAL;
793 
794         if (irq >= 0) {
795                 if (from > irq)
796                         return -EINVAL;
797                 from = irq;
798         } else {
799                 /*
800                  * For interrupts which are freely allocated the
801                  * architecture can force a lower bound to the @from
802                  * argument. x86 uses this to exclude the GSI space.
803                  */
804                 from = arch_dynirq_lower_bound(from);
805         }
806 
807         mutex_lock(&sparse_irq_lock);
808 
809         start = bitmap_find_next_zero_area(allocated_irqs, IRQ_BITMAP_BITS,
810                                            from, cnt, 0);
811         ret = -EEXIST;
812         if (irq >=0 && start != irq)
813                 goto unlock;
814 
815         if (start + cnt > nr_irqs) {
816                 ret = irq_expand_nr_irqs(start + cnt);
817                 if (ret)
818                         goto unlock;
819         }
820         ret = alloc_descs(start, cnt, node, affinity, owner);
821 unlock:
822         mutex_unlock(&sparse_irq_lock);
823         return ret;
824 }
825 EXPORT_SYMBOL_GPL(__irq_alloc_descs);
826 
827 /**
828  * irq_get_next_irq - get next allocated irq number
829  * @offset:     where to start the search
830  *
831  * Returns next irq number after offset or nr_irqs if none is found.
832  */
833 unsigned int irq_get_next_irq(unsigned int offset)
834 {
835         return find_next_bit(allocated_irqs, nr_irqs, offset);
836 }
837 
838 struct irq_desc *
839 __irq_get_desc_lock(unsigned int irq, unsigned long *flags, bool bus,
840                     unsigned int check)
841 {
842         struct irq_desc *desc = irq_to_desc(irq);
843 
844         if (desc) {
845                 if (check & _IRQ_DESC_CHECK) {
846                         if ((check & _IRQ_DESC_PERCPU) &&
847                             !irq_settings_is_per_cpu_devid(desc))
848                                 return NULL;
849 
850                         if (!(check & _IRQ_DESC_PERCPU) &&
851                             irq_settings_is_per_cpu_devid(desc))
852                                 return NULL;
853                 }
854 
855                 if (bus)
856                         chip_bus_lock(desc);
857                 raw_spin_lock_irqsave(&desc->lock, *flags);
858         }
859         return desc;
860 }
861 
862 void __irq_put_desc_unlock(struct irq_desc *desc, unsigned long flags, bool bus)
863         __releases(&desc->lock)
864 {
865         raw_spin_unlock_irqrestore(&desc->lock, flags);
866         if (bus)
867                 chip_bus_sync_unlock(desc);
868 }
869 
870 int irq_set_percpu_devid_partition(unsigned int irq,
871                                    const struct cpumask *affinity)
872 {
873         struct irq_desc *desc = irq_to_desc(irq);
874 
875         if (!desc)
876                 return -EINVAL;
877 
878         if (desc->percpu_enabled)
879                 return -EINVAL;
880 
881         desc->percpu_enabled = kzalloc(sizeof(*desc->percpu_enabled), GFP_KERNEL);
882 
883         if (!desc->percpu_enabled)
884                 return -ENOMEM;
885 
886         if (affinity)
887                 desc->percpu_affinity = affinity;
888         else
889                 desc->percpu_affinity = cpu_possible_mask;
890 
891         irq_set_percpu_devid_flags(irq);
892         return 0;
893 }
894 
895 int irq_set_percpu_devid(unsigned int irq)
896 {
897         return irq_set_percpu_devid_partition(irq, NULL);
898 }
899 
900 int irq_get_percpu_devid_partition(unsigned int irq, struct cpumask *affinity)
901 {
902         struct irq_desc *desc = irq_to_desc(irq);
903 
904         if (!desc || !desc->percpu_enabled)
905                 return -EINVAL;
906 
907         if (affinity)
908                 cpumask_copy(affinity, desc->percpu_affinity);
909 
910         return 0;
911 }
912 EXPORT_SYMBOL_GPL(irq_get_percpu_devid_partition);
913 
914 void kstat_incr_irq_this_cpu(unsigned int irq)
915 {
916         kstat_incr_irqs_this_cpu(irq_to_desc(irq));
917 }
918 
919 /**
920  * kstat_irqs_cpu - Get the statistics for an interrupt on a cpu
921  * @irq:        The interrupt number
922  * @cpu:        The cpu number
923  *
924  * Returns the sum of interrupt counts on @cpu since boot for
925  * @irq. The caller must ensure that the interrupt is not removed
926  * concurrently.
927  */
928 unsigned int kstat_irqs_cpu(unsigned int irq, int cpu)
929 {
930         struct irq_desc *desc = irq_to_desc(irq);
931 
932         return desc && desc->kstat_irqs ?
933                         *per_cpu_ptr(desc->kstat_irqs, cpu) : 0;
934 }
935 
936 static bool irq_is_nmi(struct irq_desc *desc)
937 {
938         return desc->istate & IRQS_NMI;
939 }
940 
941 static unsigned int kstat_irqs(unsigned int irq)
942 {
943         struct irq_desc *desc = irq_to_desc(irq);
944         unsigned int sum = 0;
945         int cpu;
946 
947         if (!desc || !desc->kstat_irqs)
948                 return 0;
949         if (!irq_settings_is_per_cpu_devid(desc) &&
950             !irq_settings_is_per_cpu(desc) &&
951             !irq_is_nmi(desc))
952                 return data_race(desc->tot_count);
953 
954         for_each_possible_cpu(cpu)
955                 sum += data_race(*per_cpu_ptr(desc->kstat_irqs, cpu));
956         return sum;
957 }
958 
959 /**
960  * kstat_irqs_usr - Get the statistics for an interrupt from thread context
961  * @irq:        The interrupt number
962  *
963  * Returns the sum of interrupt counts on all cpus since boot for @irq.
964  *
965  * It uses rcu to protect the access since a concurrent removal of an
966  * interrupt descriptor is observing an rcu grace period before
967  * delayed_free_desc()/irq_kobj_release().
968  */
969 unsigned int kstat_irqs_usr(unsigned int irq)
970 {
971         unsigned int sum;
972 
973         rcu_read_lock();
974         sum = kstat_irqs(irq);
975         rcu_read_unlock();
976         return sum;
977 }
978 
979 #ifdef CONFIG_LOCKDEP
980 void __irq_set_lockdep_class(unsigned int irq, struct lock_class_key *lock_class,
981                              struct lock_class_key *request_class)
982 {
983         struct irq_desc *desc = irq_to_desc(irq);
984 
985         if (desc) {
986                 lockdep_set_class(&desc->lock, lock_class);
987                 lockdep_set_class(&desc->request_mutex, request_class);
988         }
989 }
990 EXPORT_SYMBOL_GPL(__irq_set_lockdep_class);
991 #endif
992 

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