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++) {
 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                 mutex_init(&desc[i].request_mutex);
 562                 desc_set_defaults(i, &desc[i], node, NULL, NULL);
 563         }
 564         return arch_early_irq_init();
 565 }
 566
 567 struct irq_desc *irq_to_desc(unsigned int irq)
 568 {
 569         return (irq < NR_IRQS) ? irq_desc + irq : NULL;
 570 }
 571 EXPORT_SYMBOL(irq_to_desc);
 572
 573 static void free_desc(unsigned int irq)
 574 {
 575         struct irq_desc *desc = irq_to_desc(irq);
 576         unsigned long flags;
 577
 578         raw_spin_lock_irqsave(&desc->lock, flags);
 579         desc_set_defaults(irq, desc, irq_desc_get_node(desc), NULL, NULL);
 580         raw_spin_unlock_irqrestore(&desc->lock, flags);
 581 }
 582
 583 static inline int alloc_descs(unsigned int start, unsigned int cnt, int node,
 584                               const struct irq_affinity_desc *affinity,
 585                               struct module *owner)
 586 {
 587         u32 i;
 588
 589         for (i = 0; i < cnt; i++) {
 590                 struct irq_desc *desc = irq_to_desc(start + i);
 591
 592                 desc->owner = owner;
 593         }
 594         bitmap_set(allocated_irqs, start, cnt);
 595         return start;
 596 }
 597
 598 static int irq_expand_nr_irqs(unsigned int nr)
 599 {
 600         return -ENOMEM;
 601 }
 602
 603 void irq_mark_irq(unsigned int irq)
 604 {
 605         mutex_lock(&sparse_irq_lock);
 606         bitmap_set(allocated_irqs, irq, 1);
 607         mutex_unlock(&sparse_irq_lock);
 608 }
 609
 610 #ifdef CONFIG_GENERIC_IRQ_LEGACY
 611 void irq_init_desc(unsigned int irq)
 612 {
 613         free_desc(irq);
 614 }
 615 #endif
 616
 617 #endif /* !CONFIG_SPARSE_IRQ */
 618
 619 /**
 620  * generic_handle_irq - Invoke the handler for a particular irq
 621  * @irq:        The irq number to handle
 622  *
 623  */
 624 int generic_handle_irq(unsigned int irq)
 625 {
 626         struct irq_desc *desc = irq_to_desc(irq);
 627
 628         if (!desc)
 629                 return -EINVAL;
 630         generic_handle_irq_desc(desc);
 631         return 0;
 632 }
 633 EXPORT_SYMBOL_GPL(generic_handle_irq);
 634
 635 #ifdef CONFIG_HANDLE_DOMAIN_IRQ
 636 /**
 637  * __handle_domain_irq - Invoke the handler for a HW irq belonging to a domain
 638  * @domain:     The domain where to perform the lookup
 639  * @hwirq:      The HW irq number to convert to a logical one
 640  * @lookup:     Whether to perform the domain lookup or not
 641  * @regs:       Register file coming from the low-level handling code
 642  *
 643  * Returns:     0 on success, or -EINVAL if conversion has failed
 644  */
 645 int __handle_domain_irq(struct irq_domain *domain, unsigned int hwirq,
 646                         bool lookup, struct pt_regs *regs)
 647 {
 648         struct pt_regs *old_regs = set_irq_regs(regs);
 649         unsigned int irq = hwirq;
 650         int ret = 0;
 651
 652         irq_enter();
 653
 654 #ifdef CONFIG_IRQ_DOMAIN
 655         if (lookup)
 656                 irq = irq_find_mapping(domain, hwirq);
 657 #endif
 658
 659         /*
 660          * Some hardware gives randomly wrong interrupts.  Rather
 661          * than crashing, do something sensible.
 662          */
 663         if (unlikely(!irq || irq >= nr_irqs)) {
 664                 ack_bad_irq(irq);
 665                 ret = -EINVAL;
 666         } else {
 667                 generic_handle_irq(irq);
 668         }
 669
 670         irq_exit();
 671         set_irq_regs(old_regs);
 672         return ret;
 673 }
 674
 675 #ifdef CONFIG_IRQ_DOMAIN
 676 /**
 677  * handle_domain_nmi - Invoke the handler for a HW irq belonging to a domain
 678  * @domain:     The domain where to perform the lookup
 679  * @hwirq:      The HW irq number to convert to a logical one
 680  * @regs:       Register file coming from the low-level handling code
 681  *
 682  * Returns:     0 on success, or -EINVAL if conversion has failed
 683  */
 684 int handle_domain_nmi(struct irq_domain *domain, unsigned int hwirq,
 685                       struct pt_regs *regs)
 686 {
 687         struct pt_regs *old_regs = set_irq_regs(regs);
 688         unsigned int irq;
 689         int ret = 0;
 690
 691         nmi_enter();
 692
 693         irq = irq_find_mapping(domain, hwirq);
 694
 695         /*
 696          * ack_bad_irq is not NMI-safe, just report
 697          * an invalid interrupt.
 698          */
 699         if (likely(irq))
 700                 generic_handle_irq(irq);
 701         else
 702                 ret = -EINVAL;
 703
 704         nmi_exit();
 705         set_irq_regs(old_regs);
 706         return ret;
 707 }
 708 #endif
 709 #endif
 710
 711 /* Dynamic interrupt handling */
 712
 713 /**
 714  * irq_free_descs - free irq descriptors
 715  * @from:       Start of descriptor range
 716  * @cnt:        Number of consecutive irqs to free
 717  */
 718 void irq_free_descs(unsigned int from, unsigned int cnt)
 719 {
 720         int i;
 721
 722         if (from >= nr_irqs || (from + cnt) > nr_irqs)
 723                 return;
 724
 725         mutex_lock(&sparse_irq_lock);
 726         for (i = 0; i < cnt; i++)
 727                 free_desc(from + i);
 728
 729         bitmap_clear(allocated_irqs, from, cnt);
 730         mutex_unlock(&sparse_irq_lock);
 731 }
 732 EXPORT_SYMBOL_GPL(irq_free_descs);
 733
 734 /**
 735  * irq_alloc_descs - allocate and initialize a range of irq descriptors
 736  * @irq:        Allocate for specific irq number if irq >= 0
 737  * @from:       Start the search from this irq number
 738  * @cnt:        Number of consecutive irqs to allocate.
 739  * @node:       Preferred node on which the irq descriptor should be allocated
 740  * @owner:      Owning module (can be NULL)
 741  * @affinity:   Optional pointer to an affinity mask array of size @cnt which
 742  *              hints where the irq descriptors should be allocated and which
 743  *              default affinities to use
 744  *
 745  * Returns the first irq number or error code
 746  */
 747 int __ref
 748 __irq_alloc_descs(int irq, unsigned int from, unsigned int cnt, int node,
 749                   struct module *owner, const struct irq_affinity_desc *affinity)
 750 {
 751         int start, ret;
 752
 753         if (!cnt)
 754                 return -EINVAL;
 755
 756         if (irq >= 0) {
 757                 if (from > irq)
 758                         return -EINVAL;
 759                 from = irq;
 760         } else {
 761                 /*
 762                  * For interrupts which are freely allocated the
 763                  * architecture can force a lower bound to the @from
 764                  * argument. x86 uses this to exclude the GSI space.
 765                  */
 766                 from = arch_dynirq_lower_bound(from);
 767         }
 768
 769         mutex_lock(&sparse_irq_lock);
 770
 771         start = bitmap_find_next_zero_area(allocated_irqs, IRQ_BITMAP_BITS,
 772                                            from, cnt, 0);
 773         ret = -EEXIST;
 774         if (irq >=0 && start != irq)
 775                 goto unlock;
 776
 777         if (start + cnt > nr_irqs) {
 778                 ret = irq_expand_nr_irqs(start + cnt);
 779                 if (ret)
 780                         goto unlock;
 781         }
 782         ret = alloc_descs(start, cnt, node, affinity, owner);
 783 unlock:
 784         mutex_unlock(&sparse_irq_lock);
 785         return ret;
 786 }
 787 EXPORT_SYMBOL_GPL(__irq_alloc_descs);
 788
 789 #ifdef CONFIG_GENERIC_IRQ_LEGACY_ALLOC_HWIRQ
 790 /**
 791  * irq_alloc_hwirqs - Allocate an irq descriptor and initialize the hardware
 792  * @cnt:        number of interrupts to allocate
 793  * @node:       node on which to allocate
 794  *
 795  * Returns an interrupt number > 0 or 0, if the allocation fails.
 796  */
 797 unsigned int irq_alloc_hwirqs(int cnt, int node)
 798 {
 799         int i, irq = __irq_alloc_descs(-1, 0, cnt, node, NULL, NULL);
 800
 801         if (irq < 0)
 802                 return 0;
 803
 804         for (i = irq; cnt > 0; i++, cnt--) {
 805                 if (arch_setup_hwirq(i, node))
 806                         goto err;
 807                 irq_clear_status_flags(i, _IRQ_NOREQUEST);
 808         }
 809         return irq;
 810
 811 err:
 812         for (i--; i >= irq; i--) {
 813                 irq_set_status_flags(i, _IRQ_NOREQUEST | _IRQ_NOPROBE);
 814                 arch_teardown_hwirq(i);
 815         }
 816         irq_free_descs(irq, cnt);
 817         return 0;
 818 }
 819 EXPORT_SYMBOL_GPL(irq_alloc_hwirqs);
 820
 821 /**
 822  * irq_free_hwirqs - Free irq descriptor and cleanup the hardware
 823  * @from:       Free from irq number
 824  * @cnt:        number of interrupts to free
 825  *
 826  */
 827 void irq_free_hwirqs(unsigned int from, int cnt)
 828 {
 829         int i, j;
 830
 831         for (i = from, j = cnt; j > 0; i++, j--) {
 832                 irq_set_status_flags(i, _IRQ_NOREQUEST | _IRQ_NOPROBE);
 833                 arch_teardown_hwirq(i);
 834         }
 835         irq_free_descs(from, cnt);
 836 }
 837 EXPORT_SYMBOL_GPL(irq_free_hwirqs);
 838 #endif
 839
 840 /**
 841  * irq_get_next_irq - get next allocated irq number
 842  * @offset:     where to start the search
 843  *
 844  * Returns next irq number after offset or nr_irqs if none is found.
 845  */
 846 unsigned int irq_get_next_irq(unsigned int offset)
 847 {
 848         return find_next_bit(allocated_irqs, nr_irqs, offset);
 849 }
 850
 851 struct irq_desc *
 852 __irq_get_desc_lock(unsigned int irq, unsigned long *flags, bool bus,
 853                     unsigned int check)
 854 {
 855         struct irq_desc *desc = irq_to_desc(irq);
 856
 857         if (desc) {
 858                 if (check & _IRQ_DESC_CHECK) {
 859                         if ((check & _IRQ_DESC_PERCPU) &&
 860                             !irq_settings_is_per_cpu_devid(desc))
 861                                 return NULL;
 862
 863                         if (!(check & _IRQ_DESC_PERCPU) &&
 864                             irq_settings_is_per_cpu_devid(desc))
 865                                 return NULL;
 866                 }
 867
 868                 if (bus)
 869                         chip_bus_lock(desc);
 870                 raw_spin_lock_irqsave(&desc->lock, *flags);
 871         }
 872         return desc;
 873 }
 874
 875 void __irq_put_desc_unlock(struct irq_desc *desc, unsigned long flags, bool bus)
 876 {
 877         raw_spin_unlock_irqrestore(&desc->lock, flags);
 878         if (bus)
 879                 chip_bus_sync_unlock(desc);
 880 }
 881
 882 int irq_set_percpu_devid_partition(unsigned int irq,
 883                                    const struct cpumask *affinity)
 884 {
 885         struct irq_desc *desc = irq_to_desc(irq);
 886
 887         if (!desc)
 888                 return -EINVAL;
 889
 890         if (desc->percpu_enabled)
 891                 return -EINVAL;
 892
 893         desc->percpu_enabled = kzalloc(sizeof(*desc->percpu_enabled), GFP_KERNEL);
 894
 895         if (!desc->percpu_enabled)
 896                 return -ENOMEM;
 897
 898         if (affinity)
 899                 desc->percpu_affinity = affinity;
 900         else
 901                 desc->percpu_affinity = cpu_possible_mask;
 902
 903         irq_set_percpu_devid_flags(irq);
 904         return 0;
 905 }
 906
 907 int irq_set_percpu_devid(unsigned int irq)
 908 {
 909         return irq_set_percpu_devid_partition(irq, NULL);
 910 }
 911
 912 int irq_get_percpu_devid_partition(unsigned int irq, struct cpumask *affinity)
 913 {
 914         struct irq_desc *desc = irq_to_desc(irq);
 915
 916         if (!desc || !desc->percpu_enabled)
 917                 return -EINVAL;
 918
 919         if (affinity)
 920                 cpumask_copy(affinity, desc->percpu_affinity);
 921
 922         return 0;
 923 }
 924 EXPORT_SYMBOL_GPL(irq_get_percpu_devid_partition);
 925
 926 void kstat_incr_irq_this_cpu(unsigned int irq)
 927 {
 928         kstat_incr_irqs_this_cpu(irq_to_desc(irq));
 929 }
 930
 931 /**
 932  * kstat_irqs_cpu - Get the statistics for an interrupt on a cpu
 933  * @irq:        The interrupt number
 934  * @cpu:        The cpu number
 935  *
 936  * Returns the sum of interrupt counts on @cpu since boot for
 937  * @irq. The caller must ensure that the interrupt is not removed
 938  * concurrently.
 939  */
 940 unsigned int kstat_irqs_cpu(unsigned int irq, int cpu)
 941 {
 942         struct irq_desc *desc = irq_to_desc(irq);
 943
 944         return desc && desc->kstat_irqs ?
 945                         *per_cpu_ptr(desc->kstat_irqs, cpu) : 0;
 946 }
 947
 948 /**
 949  * kstat_irqs - Get the statistics for an interrupt
 950  * @irq:        The interrupt number
 951  *
 952  * Returns the sum of interrupt counts on all cpus since boot for
 953  * @irq. The caller must ensure that the interrupt is not removed
 954  * concurrently.
 955  */
 956 unsigned int kstat_irqs(unsigned int irq)
 957 {
 958         struct irq_desc *desc = irq_to_desc(irq);
 959         unsigned int sum = 0;
 960         int cpu;
 961
 962         if (!desc || !desc->kstat_irqs)
 963                 return 0;
 964         if (!irq_settings_is_per_cpu_devid(desc) &&
 965             !irq_settings_is_per_cpu(desc))
 966             return desc->tot_count;
 967
 968         for_each_possible_cpu(cpu)
 969                 sum += *per_cpu_ptr(desc->kstat_irqs, cpu);
 970         return sum;
 971 }
 972
 973 /**
 974  * kstat_irqs_usr - Get the statistics for an interrupt
 975  * @irq:        The interrupt number
 976  *
 977  * Returns the sum of interrupt counts on all cpus since boot for @irq.
 978  * Contrary to kstat_irqs() this can be called from any context.
 979  * It uses rcu since a concurrent removal of an interrupt descriptor is
 980  * observing an rcu grace period before delayed_free_desc()/irq_kobj_release().
 981  */
 982 unsigned int kstat_irqs_usr(unsigned int irq)
 983 {
 984         unsigned int sum;
 985
 986         rcu_read_lock();
 987         sum = kstat_irqs(irq);
 988         rcu_read_unlock();
 989         return sum;
 990 }