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