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