kernel/irq/irqdesc.c

   1 /*
   2  * Copyright (C) 1992, 1998-2006 Linus Torvalds, Ingo Molnar
   3  * Copyright (C) 2005-2006, Thomas Gleixner, Russell King
   4  *
   5  * This file contains the interrupt descriptor management code
   6  *
   7  * Detailed 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         zalloc_cpumask_var(&irq_default_affinity, GFP_NOWAIT);
  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 #ifdef CONFIG_CPUMASK_OFFSTACK
  44         if (!irq_default_affinity)
  45                 zalloc_cpumask_var(&irq_default_affinity, GFP_NOWAIT);
  46 #endif
  47         if (cpumask_empty(irq_default_affinity))
  48                 cpumask_setall(irq_default_affinity);
  49 }
  50 #else
  51 static void __init init_irq_default_affinity(void)
  52 {
  53 }
  54 #endif
  55
  56 #ifdef CONFIG_SMP
  57 static int alloc_masks(struct irq_desc *desc, int node)
  58 {
  59         if (!zalloc_cpumask_var_node(&desc->irq_common_data.affinity,
  60                                      GFP_KERNEL, node))
  61                 return -ENOMEM;
  62
  63 #ifdef CONFIG_GENERIC_IRQ_EFFECTIVE_AFF_MASK
  64         if (!zalloc_cpumask_var_node(&desc->irq_common_data.effective_affinity,
  65                                      GFP_KERNEL, node)) {
  66                 free_cpumask_var(desc->irq_common_data.affinity);
  67                 return -ENOMEM;
  68         }
  69 #endif
  70
  71 #ifdef CONFIG_GENERIC_PENDING_IRQ
  72         if (!zalloc_cpumask_var_node(&desc->pending_mask, GFP_KERNEL, node)) {
  73 #ifdef CONFIG_GENERIC_IRQ_EFFECTIVE_AFF_MASK
  74                 free_cpumask_var(desc->irq_common_data.effective_affinity);
  75 #endif
  76                 free_cpumask_var(desc->irq_common_data.affinity);
  77                 return -ENOMEM;
  78         }
  79 #endif
  80         return 0;
  81 }
  82
  83 static void desc_smp_init(struct irq_desc *desc, int node,
  84                           const struct cpumask *affinity)
  85 {
  86         if (!affinity)
  87                 affinity = irq_default_affinity;
  88         cpumask_copy(desc->irq_common_data.affinity, affinity);
  89
  90 #ifdef CONFIG_GENERIC_PENDING_IRQ
  91         cpumask_clear(desc->pending_mask);
  92 #endif
  93 #ifdef CONFIG_NUMA
  94         desc->irq_common_data.node = node;
  95 #endif
  96 }
  97
  98 #else
  99 static inline int
 100 alloc_masks(struct irq_desc *desc, int node) { return 0; }
 101 static inline void
 102 desc_smp_init(struct irq_desc *desc, int node, const struct cpumask *affinity) { }
 103 #endif
 104
 105 static void desc_set_defaults(unsigned int irq, struct irq_desc *desc, int node,
 106                               const struct cpumask *affinity, struct module *owner)
 107 {
 108         int cpu;
 109
 110         desc->irq_common_data.handler_data = NULL;
 111         desc->irq_common_data.msi_desc = NULL;
 112
 113         desc->irq_data.common = &desc->irq_common_data;
 114         desc->irq_data.irq = irq;
 115         desc->irq_data.chip = &no_irq_chip;
 116         desc->irq_data.chip_data = NULL;
 117         irq_settings_clr_and_set(desc, ~0, _IRQ_DEFAULT_INIT_FLAGS);
 118         irqd_set(&desc->irq_data, IRQD_IRQ_DISABLED);
 119         irqd_set(&desc->irq_data, IRQD_IRQ_MASKED);
 120         desc->handle_irq = handle_bad_irq;
 121         desc->depth = 1;
 122         desc->irq_count = 0;
 123         desc->irqs_unhandled = 0;
 124         desc->name = NULL;
 125         desc->owner = owner;
 126         for_each_possible_cpu(cpu)
 127                 *per_cpu_ptr(desc->kstat_irqs, cpu) = 0;
 128         desc_smp_init(desc, node, affinity);
 129 }
 130
 131 int nr_irqs = NR_IRQS;
 132 EXPORT_SYMBOL_GPL(nr_irqs);
 133
 134 static DEFINE_MUTEX(sparse_irq_lock);
 135 static DECLARE_BITMAP(allocated_irqs, IRQ_BITMAP_BITS);
 136
 137 #ifdef CONFIG_SPARSE_IRQ
 138
 139 static void irq_kobj_release(struct kobject *kobj);
 140
 141 #ifdef CONFIG_SYSFS
 142 static struct kobject *irq_kobj_base;
 143
 144 #define IRQ_ATTR_RO(_name) \
 145 static struct kobj_attribute _name##_attr = __ATTR_RO(_name)
 146
 147 static ssize_t per_cpu_count_show(struct kobject *kobj,
 148                                   struct kobj_attribute *attr, char *buf)
 149 {
 150         struct irq_desc *desc = container_of(kobj, struct irq_desc, kobj);
 151         int cpu, irq = desc->irq_data.irq;
 152         ssize_t ret = 0;
 153         char *p = "";
 154
 155         for_each_possible_cpu(cpu) {
 156                 unsigned int c = kstat_irqs_cpu(irq, cpu);
 157
 158                 ret += scnprintf(buf + ret, PAGE_SIZE - ret, "%s%u", p, c);
 159                 p = ",";
 160         }
 161
 162         ret += scnprintf(buf + ret, PAGE_SIZE - ret, "\n");
 163         return ret;
 164 }
 165 IRQ_ATTR_RO(per_cpu_count);
 166
 167 static ssize_t chip_name_show(struct kobject *kobj,
 168                               struct kobj_attribute *attr, char *buf)
 169 {
 170         struct irq_desc *desc = container_of(kobj, struct irq_desc, kobj);
 171         ssize_t ret = 0;
 172
 173         raw_spin_lock_irq(&desc->lock);
 174         if (desc->irq_data.chip && desc->irq_data.chip->name) {
 175                 ret = scnprintf(buf, PAGE_SIZE, "%s\n",
 176                                 desc->irq_data.chip->name);
 177         }
 178         raw_spin_unlock_irq(&desc->lock);
 179
 180         return ret;
 181 }
 182 IRQ_ATTR_RO(chip_name);
 183
 184 static ssize_t hwirq_show(struct kobject *kobj,
 185                           struct kobj_attribute *attr, char *buf)
 186 {
 187         struct irq_desc *desc = container_of(kobj, struct irq_desc, kobj);
 188         ssize_t ret = 0;
 189
 190         raw_spin_lock_irq(&desc->lock);
 191         if (desc->irq_data.domain)
 192                 ret = sprintf(buf, "%d\n", (int)desc->irq_data.hwirq);
 193         raw_spin_unlock_irq(&desc->lock);
 194
 195         return ret;
 196 }
 197 IRQ_ATTR_RO(hwirq);
 198
 199 static ssize_t type_show(struct kobject *kobj,
 200                          struct kobj_attribute *attr, char *buf)
 201 {
 202         struct irq_desc *desc = container_of(kobj, struct irq_desc, kobj);
 203         ssize_t ret = 0;
 204
 205         raw_spin_lock_irq(&desc->lock);
 206         ret = sprintf(buf, "%s\n",
 207                       irqd_is_level_type(&desc->irq_data) ? "level" : "edge");
 208         raw_spin_unlock_irq(&desc->lock);
 209
 210         return ret;
 211
 212 }
 213 IRQ_ATTR_RO(type);
 214
 215 static ssize_t name_show(struct kobject *kobj,
 216                          struct kobj_attribute *attr, char *buf)
 217 {
 218         struct irq_desc *desc = container_of(kobj, struct irq_desc, kobj);
 219         ssize_t ret = 0;
 220
 221         raw_spin_lock_irq(&desc->lock);
 222         if (desc->name)
 223                 ret = scnprintf(buf, PAGE_SIZE, "%s\n", desc->name);
 224         raw_spin_unlock_irq(&desc->lock);
 225
 226         return ret;
 227 }
 228 IRQ_ATTR_RO(name);
 229
 230 static ssize_t actions_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         struct irqaction *action;
 235         ssize_t ret = 0;
 236         char *p = "";
 237
 238         raw_spin_lock_irq(&desc->lock);
 239         for (action = desc->action; action != NULL; action = action->next) {
 240                 ret += scnprintf(buf + ret, PAGE_SIZE - ret, "%s%s",
 241                                  p, action->name);
 242                 p = ",";
 243         }
 244         raw_spin_unlock_irq(&desc->lock);
 245
 246         if (ret)
 247                 ret += scnprintf(buf + ret, PAGE_SIZE - ret, "\n");
 248
 249         return ret;
 250 }
 251 IRQ_ATTR_RO(actions);
 252
 253 static struct attribute *irq_attrs[] = {
 254         &per_cpu_count_attr.attr,
 255         &chip_name_attr.attr,
 256         &hwirq_attr.attr,
 257         &type_attr.attr,
 258         &name_attr.attr,
 259         &actions_attr.attr,
 260         NULL
 261 };
 262
 263 static struct kobj_type irq_kobj_type = {
 264         .release        = irq_kobj_release,
 265         .sysfs_ops      = &kobj_sysfs_ops,
 266         .default_attrs  = irq_attrs,
 267 };
 268
 269 static void irq_sysfs_add(int irq, struct irq_desc *desc)
 270 {
 271         if (irq_kobj_base) {
 272                 /*
 273                  * Continue even in case of failure as this is nothing
 274                  * crucial.
 275                  */
 276                 if (kobject_add(&desc->kobj, irq_kobj_base, "%d", irq))
 277                         pr_warn("Failed to add kobject for irq %d\n", irq);
 278         }
 279 }
 280
 281 static int __init irq_sysfs_init(void)
 282 {
 283         struct irq_desc *desc;
 284         int irq;
 285
 286         /* Prevent concurrent irq alloc/free */
 287         irq_lock_sparse();
 288
 289         irq_kobj_base = kobject_create_and_add("irq", kernel_kobj);
 290         if (!irq_kobj_base) {
 291                 irq_unlock_sparse();
 292                 return -ENOMEM;
 293         }
 294
 295         /* Add the already allocated interrupts */
 296         for_each_irq_desc(irq, desc)
 297                 irq_sysfs_add(irq, desc);
 298         irq_unlock_sparse();
 299
 300         return 0;
 301 }
 302 postcore_initcall(irq_sysfs_init);
 303
 304 #else /* !CONFIG_SYSFS */
 305
 306 static struct kobj_type irq_kobj_type = {
 307         .release        = irq_kobj_release,
 308 };
 309
 310 static void irq_sysfs_add(int irq, struct irq_desc *desc) {}
 311
 312 #endif /* CONFIG_SYSFS */
 313
 314 static RADIX_TREE(irq_desc_tree, GFP_KERNEL);
 315
 316 static void irq_insert_desc(unsigned int irq, struct irq_desc *desc)
 317 {
 318         radix_tree_insert(&irq_desc_tree, irq, desc);
 319 }
 320
 321 struct irq_desc *irq_to_desc(unsigned int irq)
 322 {
 323         return radix_tree_lookup(&irq_desc_tree, irq);
 324 }
 325 EXPORT_SYMBOL(irq_to_desc);
 326
 327 static void delete_irq_desc(unsigned int irq)
 328 {
 329         radix_tree_delete(&irq_desc_tree, irq);
 330 }
 331
 332 #ifdef CONFIG_SMP
 333 static void free_masks(struct irq_desc *desc)
 334 {
 335 #ifdef CONFIG_GENERIC_PENDING_IRQ
 336         free_cpumask_var(desc->pending_mask);
 337 #endif
 338         free_cpumask_var(desc->irq_common_data.affinity);
 339 #ifdef CONFIG_GENERIC_IRQ_EFFECTIVE_AFF_MASK
 340         free_cpumask_var(desc->irq_common_data.effective_affinity);
 341 #endif
 342 }
 343 #else
 344 static inline void free_masks(struct irq_desc *desc) { }
 345 #endif
 346
 347 void irq_lock_sparse(void)
 348 {
 349         mutex_lock(&sparse_irq_lock);
 350 }
 351
 352 void irq_unlock_sparse(void)
 353 {
 354         mutex_unlock(&sparse_irq_lock);
 355 }
 356
 357 static struct irq_desc *alloc_desc(int irq, int node, unsigned int flags,
 358                                    const struct cpumask *affinity,
 359                                    struct module *owner)
 360 {
 361         struct irq_desc *desc;
 362
 363         desc = kzalloc_node(sizeof(*desc), GFP_KERNEL, node);
 364         if (!desc)
 365                 return NULL;
 366         /* allocate based on nr_cpu_ids */
 367         desc->kstat_irqs = alloc_percpu(unsigned int);
 368         if (!desc->kstat_irqs)
 369                 goto err_desc;
 370
 371         if (alloc_masks(desc, node))
 372                 goto err_kstat;
 373
 374         raw_spin_lock_init(&desc->lock);
 375         lockdep_set_class(&desc->lock, &irq_desc_lock_class);
 376         mutex_init(&desc->request_mutex);
 377         init_rcu_head(&desc->rcu);
 378
 379         desc_set_defaults(irq, desc, node, affinity, owner);
 380         irqd_set(&desc->irq_data, flags);
 381         kobject_init(&desc->kobj, &irq_kobj_type);
 382
 383         return desc;
 384
 385 err_kstat:
 386         free_percpu(desc->kstat_irqs);
 387 err_desc:
 388         kfree(desc);
 389         return NULL;
 390 }
 391
 392 static void irq_kobj_release(struct kobject *kobj)
 393 {
 394         struct irq_desc *desc = container_of(kobj, struct irq_desc, kobj);
 395
 396         free_masks(desc);
 397         free_percpu(desc->kstat_irqs);
 398         kfree(desc);
 399 }
 400
 401 static void delayed_free_desc(struct rcu_head *rhp)
 402 {
 403         struct irq_desc *desc = container_of(rhp, struct irq_desc, rcu);
 404
 405         kobject_put(&desc->kobj);
 406 }
 407
 408 static void free_desc(unsigned int irq)
 409 {
 410         struct irq_desc *desc = irq_to_desc(irq);
 411
 412         irq_remove_debugfs_entry(desc);
 413         unregister_irq_proc(irq, desc);
 414
 415         /*
 416          * sparse_irq_lock protects also show_interrupts() and
 417          * kstat_irq_usr(). Once we deleted the descriptor from the
 418          * sparse tree we can free it. Access in proc will fail to
 419          * lookup the descriptor.
 420          *
 421          * The sysfs entry must be serialized against a concurrent
 422          * irq_sysfs_init() as well.
 423          */
 424         mutex_lock(&sparse_irq_lock);
 425         kobject_del(&desc->kobj);
 426         delete_irq_desc(irq);
 427         mutex_unlock(&sparse_irq_lock);
 428
 429         /*
 430          * We free the descriptor, masks and stat fields via RCU. That
 431          * allows demultiplex interrupts to do rcu based management of
 432          * the child interrupts.
 433          */
 434         call_rcu(&desc->rcu, delayed_free_desc);
 435 }
 436
 437 static int alloc_descs(unsigned int start, unsigned int cnt, int node,
 438                        const struct cpumask *affinity, struct module *owner)
 439 {
 440         const struct cpumask *mask = NULL;
 441         struct irq_desc *desc;
 442         unsigned int flags;
 443         int i;
 444
 445         /* Validate affinity mask(s) */
 446         if (affinity) {
 447                 for (i = 0, mask = affinity; i < cnt; i++, mask++) {
 448                         if (cpumask_empty(mask))
 449                                 return -EINVAL;
 450                 }
 451         }
 452
 453         flags = affinity ? IRQD_AFFINITY_MANAGED : 0;
 454         mask = NULL;
 455
 456         for (i = 0; i < cnt; i++) {
 457                 if (affinity) {
 458                         node = cpu_to_node(cpumask_first(affinity));
 459                         mask = affinity;
 460                         affinity++;
 461                 }
 462                 desc = alloc_desc(start + i, node, flags, mask, owner);
 463                 if (!desc)
 464                         goto err;
 465                 mutex_lock(&sparse_irq_lock);
 466                 irq_insert_desc(start + i, desc);
 467                 irq_sysfs_add(start + i, desc);
 468                 mutex_unlock(&sparse_irq_lock);
 469         }
 470         return start;
 471
 472 err:
 473         for (i--; i >= 0; i--)
 474                 free_desc(start + i);
 475
 476         mutex_lock(&sparse_irq_lock);
 477         bitmap_clear(allocated_irqs, start, cnt);
 478         mutex_unlock(&sparse_irq_lock);
 479         return -ENOMEM;
 480 }
 481
 482 static int irq_expand_nr_irqs(unsigned int nr)
 483 {
 484         if (nr > IRQ_BITMAP_BITS)
 485                 return -ENOMEM;
 486         nr_irqs = nr;
 487         return 0;
 488 }
 489
 490 int __init early_irq_init(void)
 491 {
 492         int i, initcnt, node = first_online_node;
 493         struct irq_desc *desc;
 494
 495         init_irq_default_affinity();
 496
 497         /* Let arch update nr_irqs and return the nr of preallocated irqs */
 498         initcnt = arch_probe_nr_irqs();
 499         printk(KERN_INFO "NR_IRQS: %d, nr_irqs: %d, preallocated irqs: %d\n",
 500                NR_IRQS, nr_irqs, initcnt);
 501
 502         if (WARN_ON(nr_irqs > IRQ_BITMAP_BITS))
 503                 nr_irqs = IRQ_BITMAP_BITS;
 504
 505         if (WARN_ON(initcnt > IRQ_BITMAP_BITS))
 506                 initcnt = IRQ_BITMAP_BITS;
 507
 508         if (initcnt > nr_irqs)
 509                 nr_irqs = initcnt;
 510
 511         for (i = 0; i < initcnt; i++) {
 512                 desc = alloc_desc(i, node, 0, NULL, NULL);
 513                 set_bit(i, allocated_irqs);
 514                 irq_insert_desc(i, desc);
 515         }
 516         return arch_early_irq_init();
 517 }
 518
 519 #else /* !CONFIG_SPARSE_IRQ */
 520
 521 struct irq_desc irq_desc[NR_IRQS] __cacheline_aligned_in_smp = {
 522         [0 ... NR_IRQS-1] = {
 523                 .handle_irq     = handle_bad_irq,
 524                 .depth          = 1,
 525                 .lock           = __RAW_SPIN_LOCK_UNLOCKED(irq_desc->lock),
 526         }
 527 };
 528
 529 int __init early_irq_init(void)
 530 {
 531         int count, i, node = first_online_node;
 532         struct irq_desc *desc;
 533
 534         init_irq_default_affinity();
 535
 536         printk(KERN_INFO "NR_IRQS: %d\n", NR_IRQS);
 537
 538         desc = irq_desc;
 539         count = ARRAY_SIZE(irq_desc);
 540
 541         for (i = 0; i < count; i++) {
 542                 desc[i].kstat_irqs = alloc_percpu(unsigned int);
 543                 alloc_masks(&desc[i], node);
 544                 raw_spin_lock_init(&desc[i].lock);
 545                 lockdep_set_class(&desc[i].lock, &irq_desc_lock_class);
 546                 desc_set_defaults(i, &desc[i], node, NULL, NULL);
 547         }
 548         return arch_early_irq_init();
 549 }
 550
 551 struct irq_desc *irq_to_desc(unsigned int irq)
 552 {
 553         return (irq < NR_IRQS) ? irq_desc + irq : NULL;
 554 }
 555 EXPORT_SYMBOL(irq_to_desc);
 556
 557 static void free_desc(unsigned int irq)
 558 {
 559         struct irq_desc *desc = irq_to_desc(irq);
 560         unsigned long flags;
 561
 562         raw_spin_lock_irqsave(&desc->lock, flags);
 563         desc_set_defaults(irq, desc, irq_desc_get_node(desc), NULL, NULL);
 564         raw_spin_unlock_irqrestore(&desc->lock, flags);
 565 }
 566
 567 static inline int alloc_descs(unsigned int start, unsigned int cnt, int node,
 568                               const struct cpumask *affinity,
 569                               struct module *owner)
 570 {
 571         u32 i;
 572
 573         for (i = 0; i < cnt; i++) {
 574                 struct irq_desc *desc = irq_to_desc(start + i);
 575
 576                 desc->owner = owner;
 577         }
 578         return start;
 579 }
 580
 581 static int irq_expand_nr_irqs(unsigned int nr)
 582 {
 583         return -ENOMEM;
 584 }
 585
 586 void irq_mark_irq(unsigned int irq)
 587 {
 588         mutex_lock(&sparse_irq_lock);
 589         bitmap_set(allocated_irqs, irq, 1);
 590         mutex_unlock(&sparse_irq_lock);
 591 }
 592
 593 #ifdef CONFIG_GENERIC_IRQ_LEGACY
 594 void irq_init_desc(unsigned int irq)
 595 {
 596         free_desc(irq);
 597 }
 598 #endif
 599
 600 #endif /* !CONFIG_SPARSE_IRQ */
 601
 602 /**
 603  * generic_handle_irq - Invoke the handler for a particular irq
 604  * @irq:        The irq number to handle
 605  *
 606  */
 607 int generic_handle_irq(unsigned int irq)
 608 {
 609         struct irq_desc *desc = irq_to_desc(irq);
 610
 611         if (!desc)
 612                 return -EINVAL;
 613         generic_handle_irq_desc(desc);
 614         return 0;
 615 }
 616 EXPORT_SYMBOL_GPL(generic_handle_irq);
 617
 618 #ifdef CONFIG_HANDLE_DOMAIN_IRQ
 619 /**
 620  * __handle_domain_irq - Invoke the handler for a HW irq belonging to a domain
 621  * @domain:     The domain where to perform the lookup
 622  * @hwirq:      The HW irq number to convert to a logical one
 623  * @lookup:     Whether to perform the domain lookup or not
 624  * @regs:       Register file coming from the low-level handling code
 625  *
 626  * Returns:     0 on success, or -EINVAL if conversion has failed
 627  */
 628 int __handle_domain_irq(struct irq_domain *domain, unsigned int hwirq,
 629                         bool lookup, struct pt_regs *regs)
 630 {
 631         struct pt_regs *old_regs = set_irq_regs(regs);
 632         unsigned int irq = hwirq;
 633         int ret = 0;
 634
 635         irq_enter();
 636
 637 #ifdef CONFIG_IRQ_DOMAIN
 638         if (lookup)
 639                 irq = irq_find_mapping(domain, hwirq);
 640 #endif
 641
 642         /*
 643          * Some hardware gives randomly wrong interrupts.  Rather
 644          * than crashing, do something sensible.
 645          */
 646         if (unlikely(!irq || irq >= nr_irqs)) {
 647                 ack_bad_irq(irq);
 648                 ret = -EINVAL;
 649         } else {
 650                 generic_handle_irq(irq);
 651         }
 652
 653         irq_exit();
 654         set_irq_regs(old_regs);
 655         return ret;
 656 }
 657 #endif
 658
 659 /* Dynamic interrupt handling */
 660
 661 /**
 662  * irq_free_descs - free irq descriptors
 663  * @from:       Start of descriptor range
 664  * @cnt:        Number of consecutive irqs to free
 665  */
 666 void irq_free_descs(unsigned int from, unsigned int cnt)
 667 {
 668         int i;
 669
 670         if (from >= nr_irqs || (from + cnt) > nr_irqs)
 671                 return;
 672
 673         for (i = 0; i < cnt; i++)
 674                 free_desc(from + i);
 675
 676         mutex_lock(&sparse_irq_lock);
 677         bitmap_clear(allocated_irqs, from, cnt);
 678         mutex_unlock(&sparse_irq_lock);
 679 }
 680 EXPORT_SYMBOL_GPL(irq_free_descs);
 681
 682 /**
 683  * irq_alloc_descs - allocate and initialize a range of irq descriptors
 684  * @irq:        Allocate for specific irq number if irq >= 0
 685  * @from:       Start the search from this irq number
 686  * @cnt:        Number of consecutive irqs to allocate.
 687  * @node:       Preferred node on which the irq descriptor should be allocated
 688  * @owner:      Owning module (can be NULL)
 689  * @affinity:   Optional pointer to an affinity mask array of size @cnt which
 690  *              hints where the irq descriptors should be allocated and which
 691  *              default affinities to use
 692  *
 693  * Returns the first irq number or error code
 694  */
 695 int __ref
 696 __irq_alloc_descs(int irq, unsigned int from, unsigned int cnt, int node,
 697                   struct module *owner, const struct cpumask *affinity)
 698 {
 699         int start, ret;
 700
 701         if (!cnt)
 702                 return -EINVAL;
 703
 704         if (irq >= 0) {
 705                 if (from > irq)
 706                         return -EINVAL;
 707                 from = irq;
 708         } else {
 709                 /*
 710                  * For interrupts which are freely allocated the
 711                  * architecture can force a lower bound to the @from
 712                  * argument. x86 uses this to exclude the GSI space.
 713                  */
 714                 from = arch_dynirq_lower_bound(from);
 715         }
 716
 717         mutex_lock(&sparse_irq_lock);
 718
 719         start = bitmap_find_next_zero_area(allocated_irqs, IRQ_BITMAP_BITS,
 720                                            from, cnt, 0);
 721         ret = -EEXIST;
 722         if (irq >=0 && start != irq)
 723                 goto err;
 724
 725         if (start + cnt > nr_irqs) {
 726                 ret = irq_expand_nr_irqs(start + cnt);
 727                 if (ret)
 728                         goto err;
 729         }
 730
 731         bitmap_set(allocated_irqs, start, cnt);
 732         mutex_unlock(&sparse_irq_lock);
 733         return alloc_descs(start, cnt, node, affinity, owner);
 734
 735 err:
 736         mutex_unlock(&sparse_irq_lock);
 737         return ret;
 738 }
 739 EXPORT_SYMBOL_GPL(__irq_alloc_descs);
 740
 741 #ifdef CONFIG_GENERIC_IRQ_LEGACY_ALLOC_HWIRQ
 742 /**
 743  * irq_alloc_hwirqs - Allocate an irq descriptor and initialize the hardware
 744  * @cnt:        number of interrupts to allocate
 745  * @node:       node on which to allocate
 746  *
 747  * Returns an interrupt number > 0 or 0, if the allocation fails.
 748  */
 749 unsigned int irq_alloc_hwirqs(int cnt, int node)
 750 {
 751         int i, irq = __irq_alloc_descs(-1, 0, cnt, node, NULL, NULL);
 752
 753         if (irq < 0)
 754                 return 0;
 755
 756         for (i = irq; cnt > 0; i++, cnt--) {
 757                 if (arch_setup_hwirq(i, node))
 758                         goto err;
 759                 irq_clear_status_flags(i, _IRQ_NOREQUEST);
 760         }
 761         return irq;
 762
 763 err:
 764         for (i--; i >= irq; i--) {
 765                 irq_set_status_flags(i, _IRQ_NOREQUEST | _IRQ_NOPROBE);
 766                 arch_teardown_hwirq(i);
 767         }
 768         irq_free_descs(irq, cnt);
 769         return 0;
 770 }
 771 EXPORT_SYMBOL_GPL(irq_alloc_hwirqs);
 772
 773 /**
 774  * irq_free_hwirqs - Free irq descriptor and cleanup the hardware
 775  * @from:       Free from irq number
 776  * @cnt:        number of interrupts to free
 777  *
 778  */
 779 void irq_free_hwirqs(unsigned int from, int cnt)
 780 {
 781         int i, j;
 782
 783         for (i = from, j = cnt; j > 0; i++, j--) {
 784                 irq_set_status_flags(i, _IRQ_NOREQUEST | _IRQ_NOPROBE);
 785                 arch_teardown_hwirq(i);
 786         }
 787         irq_free_descs(from, cnt);
 788 }
 789 EXPORT_SYMBOL_GPL(irq_free_hwirqs);
 790 #endif
 791
 792 /**
 793  * irq_get_next_irq - get next allocated irq number
 794  * @offset:     where to start the search
 795  *
 796  * Returns next irq number after offset or nr_irqs if none is found.
 797  */
 798 unsigned int irq_get_next_irq(unsigned int offset)
 799 {
 800         return find_next_bit(allocated_irqs, nr_irqs, offset);
 801 }
 802
 803 struct irq_desc *
 804 __irq_get_desc_lock(unsigned int irq, unsigned long *flags, bool bus,
 805                     unsigned int check)
 806 {
 807         struct irq_desc *desc = irq_to_desc(irq);
 808
 809         if (desc) {
 810                 if (check & _IRQ_DESC_CHECK) {
 811                         if ((check & _IRQ_DESC_PERCPU) &&
 812                             !irq_settings_is_per_cpu_devid(desc))
 813                                 return NULL;
 814
 815                         if (!(check & _IRQ_DESC_PERCPU) &&
 816                             irq_settings_is_per_cpu_devid(desc))
 817                                 return NULL;
 818                 }
 819
 820                 if (bus)
 821                         chip_bus_lock(desc);
 822                 raw_spin_lock_irqsave(&desc->lock, *flags);
 823         }
 824         return desc;
 825 }
 826
 827 void __irq_put_desc_unlock(struct irq_desc *desc, unsigned long flags, bool bus)
 828 {
 829         raw_spin_unlock_irqrestore(&desc->lock, flags);
 830         if (bus)
 831                 chip_bus_sync_unlock(desc);
 832 }
 833
 834 int irq_set_percpu_devid_partition(unsigned int irq,
 835                                    const struct cpumask *affinity)
 836 {
 837         struct irq_desc *desc = irq_to_desc(irq);
 838
 839         if (!desc)
 840                 return -EINVAL;
 841
 842         if (desc->percpu_enabled)
 843                 return -EINVAL;
 844
 845         desc->percpu_enabled = kzalloc(sizeof(*desc->percpu_enabled), GFP_KERNEL);
 846
 847         if (!desc->percpu_enabled)
 848                 return -ENOMEM;
 849
 850         if (affinity)
 851                 desc->percpu_affinity = affinity;
 852         else
 853                 desc->percpu_affinity = cpu_possible_mask;
 854
 855         irq_set_percpu_devid_flags(irq);
 856         return 0;
 857 }
 858
 859 int irq_set_percpu_devid(unsigned int irq)
 860 {
 861         return irq_set_percpu_devid_partition(irq, NULL);
 862 }
 863
 864 int irq_get_percpu_devid_partition(unsigned int irq, struct cpumask *affinity)
 865 {
 866         struct irq_desc *desc = irq_to_desc(irq);
 867
 868         if (!desc || !desc->percpu_enabled)
 869                 return -EINVAL;
 870
 871         if (affinity)
 872                 cpumask_copy(affinity, desc->percpu_affinity);
 873
 874         return 0;
 875 }
 876
 877 void kstat_incr_irq_this_cpu(unsigned int irq)
 878 {
 879         kstat_incr_irqs_this_cpu(irq_to_desc(irq));
 880 }
 881
 882 /**
 883  * kstat_irqs_cpu - Get the statistics for an interrupt on a cpu
 884  * @irq:        The interrupt number
 885  * @cpu:        The cpu number
 886  *
 887  * Returns the sum of interrupt counts on @cpu since boot for
 888  * @irq. The caller must ensure that the interrupt is not removed
 889  * concurrently.
 890  */
 891 unsigned int kstat_irqs_cpu(unsigned int irq, int cpu)
 892 {
 893         struct irq_desc *desc = irq_to_desc(irq);
 894
 895         return desc && desc->kstat_irqs ?
 896                         *per_cpu_ptr(desc->kstat_irqs, cpu) : 0;
 897 }
 898
 899 /**
 900  * kstat_irqs - Get the statistics for an interrupt
 901  * @irq:        The interrupt number
 902  *
 903  * Returns the sum of interrupt counts on all cpus since boot for
 904  * @irq. The caller must ensure that the interrupt is not removed
 905  * concurrently.
 906  */
 907 unsigned int kstat_irqs(unsigned int irq)
 908 {
 909         struct irq_desc *desc = irq_to_desc(irq);
 910         int cpu;
 911         unsigned int sum = 0;
 912
 913         if (!desc || !desc->kstat_irqs)
 914                 return 0;
 915         for_each_possible_cpu(cpu)
 916                 sum += *per_cpu_ptr(desc->kstat_irqs, cpu);
 917         return sum;
 918 }
 919
 920 /**
 921  * kstat_irqs_usr - Get the statistics for an interrupt
 922  * @irq:        The interrupt number
 923  *
 924  * Returns the sum of interrupt counts on all cpus since boot for
 925  * @irq. Contrary to kstat_irqs() this can be called from any
 926  * preemptible context. It's protected against concurrent removal of
 927  * an interrupt descriptor when sparse irqs are enabled.
 928  */
 929 unsigned int kstat_irqs_usr(unsigned int irq)
 930 {
 931         unsigned int sum;
 932
 933         irq_lock_sparse();
 934         sum = kstat_irqs(irq);
 935         irq_unlock_sparse();
 936         return sum;
 937 }