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