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