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->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 name_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         if (desc->name)
 222                 ret = scnprintf(buf, PAGE_SIZE, "%s\n", desc->name);
 223         raw_spin_unlock_irq(&desc->lock);
 224
 225         return ret;
 226 }
 227 IRQ_ATTR_RO(name);
 228
 229 static ssize_t actions_show(struct kobject *kobj,
 230                             struct kobj_attribute *attr, char *buf)
 231 {
 232         struct irq_desc *desc = container_of(kobj, struct irq_desc, kobj);
 233         struct irqaction *action;
 234         ssize_t ret = 0;
 235         char *p = "";
 236
 237         raw_spin_lock_irq(&desc->lock);
 238         for (action = desc->action; action != NULL; action = action->next) {
 239                 ret += scnprintf(buf + ret, PAGE_SIZE - ret, "%s%s",
 240                                  p, action->name);
 241                 p = ",";
 242         }
 243         raw_spin_unlock_irq(&desc->lock);
 244
 245         if (ret)
 246                 ret += scnprintf(buf + ret, PAGE_SIZE - ret, "\n");
 247
 248         return ret;
 249 }
 250 IRQ_ATTR_RO(actions);
 251
 252 static struct attribute *irq_attrs[] = {
 253         &per_cpu_count_attr.attr,
 254         &chip_name_attr.attr,
 255         &hwirq_attr.attr,
 256         &type_attr.attr,
 257         &name_attr.attr,
 258         &actions_attr.attr,
 259         NULL
 260 };
 261
 262 static struct kobj_type irq_kobj_type = {
 263         .release        = irq_kobj_release,
 264         .sysfs_ops      = &kobj_sysfs_ops,
 265         .default_attrs  = irq_attrs,
 266 };
 267
 268 static void irq_sysfs_add(int irq, struct irq_desc *desc)
 269 {
 270         if (irq_kobj_base) {
 271                 /*
 272                  * Continue even in case of failure as this is nothing
 273                  * crucial.
 274                  */
 275                 if (kobject_add(&desc->kobj, irq_kobj_base, "%d", irq))
 276                         pr_warn("Failed to add kobject for irq %d\n", irq);
 277         }
 278 }
 279
 280 static void irq_sysfs_del(struct irq_desc *desc)
 281 {
 282         /*
 283          * If irq_sysfs_init() has not yet been invoked (early boot), then
 284          * irq_kobj_base is NULL and the descriptor was never added.
 285          * kobject_del() complains about a object with no parent, so make
 286          * it conditional.
 287          */
 288         if (irq_kobj_base)
 289                 kobject_del(&desc->kobj);
 290 }
 291
 292 static int __init irq_sysfs_init(void)
 293 {
 294         struct irq_desc *desc;
 295         int irq;
 296
 297         /* Prevent concurrent irq alloc/free */
 298         irq_lock_sparse();
 299
 300         irq_kobj_base = kobject_create_and_add("irq", kernel_kobj);
 301         if (!irq_kobj_base) {
 302                 irq_unlock_sparse();
 303                 return -ENOMEM;
 304         }
 305
 306         /* Add the already allocated interrupts */
 307         for_each_irq_desc(irq, desc)
 308                 irq_sysfs_add(irq, desc);
 309         irq_unlock_sparse();
 310
 311         return 0;
 312 }
 313 postcore_initcall(irq_sysfs_init);
 314
 315 #else /* !CONFIG_SYSFS */
 316
 317 static struct kobj_type irq_kobj_type = {
 318         .release        = irq_kobj_release,
 319 };
 320
 321 static void irq_sysfs_add(int irq, struct irq_desc *desc) {}
 322 static void irq_sysfs_del(struct irq_desc *desc) {}
 323
 324 #endif /* CONFIG_SYSFS */
 325
 326 static RADIX_TREE(irq_desc_tree, GFP_KERNEL);
 327
 328 static void irq_insert_desc(unsigned int irq, struct irq_desc *desc)
 329 {
 330         radix_tree_insert(&irq_desc_tree, irq, desc);
 331 }
 332
 333 struct irq_desc *irq_to_desc(unsigned int irq)
 334 {
 335         return radix_tree_lookup(&irq_desc_tree, irq);
 336 }
 337 EXPORT_SYMBOL(irq_to_desc);
 338
 339 static void delete_irq_desc(unsigned int irq)
 340 {
 341         radix_tree_delete(&irq_desc_tree, irq);
 342 }
 343
 344 #ifdef CONFIG_SMP
 345 static void free_masks(struct irq_desc *desc)
 346 {
 347 #ifdef CONFIG_GENERIC_PENDING_IRQ
 348         free_cpumask_var(desc->pending_mask);
 349 #endif
 350         free_cpumask_var(desc->irq_common_data.affinity);
 351 #ifdef CONFIG_GENERIC_IRQ_EFFECTIVE_AFF_MASK
 352         free_cpumask_var(desc->irq_common_data.effective_affinity);
 353 #endif
 354 }
 355 #else
 356 static inline void free_masks(struct irq_desc *desc) { }
 357 #endif
 358
 359 void irq_lock_sparse(void)
 360 {
 361         mutex_lock(&sparse_irq_lock);
 362 }
 363
 364 void irq_unlock_sparse(void)
 365 {
 366         mutex_unlock(&sparse_irq_lock);
 367 }
 368
 369 static struct irq_desc *alloc_desc(int irq, int node, unsigned int flags,
 370                                    const struct cpumask *affinity,
 371                                    struct module *owner)
 372 {
 373         struct irq_desc *desc;
 374
 375         desc = kzalloc_node(sizeof(*desc), GFP_KERNEL, node);
 376         if (!desc)
 377                 return NULL;
 378         /* allocate based on nr_cpu_ids */
 379         desc->kstat_irqs = alloc_percpu(unsigned int);
 380         if (!desc->kstat_irqs)
 381                 goto err_desc;
 382
 383         if (alloc_masks(desc, node))
 384                 goto err_kstat;
 385
 386         raw_spin_lock_init(&desc->lock);
 387         lockdep_set_class(&desc->lock, &irq_desc_lock_class);
 388         mutex_init(&desc->request_mutex);
 389         init_rcu_head(&desc->rcu);
 390
 391         desc_set_defaults(irq, desc, node, affinity, owner);
 392         irqd_set(&desc->irq_data, flags);
 393         kobject_init(&desc->kobj, &irq_kobj_type);
 394
 395         return desc;
 396
 397 err_kstat:
 398         free_percpu(desc->kstat_irqs);
 399 err_desc:
 400         kfree(desc);
 401         return NULL;
 402 }
 403
 404 static void irq_kobj_release(struct kobject *kobj)
 405 {
 406         struct irq_desc *desc = container_of(kobj, struct irq_desc, kobj);
 407
 408         free_masks(desc);
 409         free_percpu(desc->kstat_irqs);
 410         kfree(desc);
 411 }
 412
 413 static void delayed_free_desc(struct rcu_head *rhp)
 414 {
 415         struct irq_desc *desc = container_of(rhp, struct irq_desc, rcu);
 416
 417         kobject_put(&desc->kobj);
 418 }
 419
 420 static void free_desc(unsigned int irq)
 421 {
 422         struct irq_desc *desc = irq_to_desc(irq);
 423
 424         irq_remove_debugfs_entry(desc);
 425         unregister_irq_proc(irq, desc);
 426
 427         /*
 428          * sparse_irq_lock protects also show_interrupts() and
 429          * kstat_irq_usr(). Once we deleted the descriptor from the
 430          * sparse tree we can free it. Access in proc will fail to
 431          * lookup the descriptor.
 432          *
 433          * The sysfs entry must be serialized against a concurrent
 434          * irq_sysfs_init() as well.
 435          */
 436         irq_sysfs_del(desc);
 437         delete_irq_desc(irq);
 438
 439         /*
 440          * We free the descriptor, masks and stat fields via RCU. That
 441          * allows demultiplex interrupts to do rcu based management of
 442          * the child interrupts.
 443          */
 444         call_rcu(&desc->rcu, delayed_free_desc);
 445 }
 446
 447 static int alloc_descs(unsigned int start, unsigned int cnt, int node,
 448                        const struct cpumask *affinity, struct module *owner)
 449 {
 450         const struct cpumask *mask = NULL;
 451         struct irq_desc *desc;
 452         unsigned int flags;
 453         int i;
 454
 455         /* Validate affinity mask(s) */
 456         if (affinity) {
 457                 for (i = 0, mask = affinity; i < cnt; i++, mask++) {
 458                         if (cpumask_empty(mask))
 459                                 return -EINVAL;
 460                 }
 461         }
 462
 463         flags = affinity ? IRQD_AFFINITY_MANAGED : 0;
 464         mask = NULL;
 465
 466         for (i = 0; i < cnt; i++) {
 467                 if (affinity) {
 468                         node = cpu_to_node(cpumask_first(affinity));
 469                         mask = affinity;
 470                         affinity++;
 471                 }
 472                 desc = alloc_desc(start + i, node, flags, mask, owner);
 473                 if (!desc)
 474                         goto err;
 475                 irq_insert_desc(start + i, desc);
 476                 irq_sysfs_add(start + i, desc);
 477         }
 478         bitmap_set(allocated_irqs, start, cnt);
 479         return start;
 480
 481 err:
 482         for (i--; i >= 0; i--)
 483                 free_desc(start + i);
 484         return -ENOMEM;
 485 }
 486
 487 static int irq_expand_nr_irqs(unsigned int nr)
 488 {
 489         if (nr > IRQ_BITMAP_BITS)
 490                 return -ENOMEM;
 491         nr_irqs = nr;
 492         return 0;
 493 }
 494
 495 int __init early_irq_init(void)
 496 {
 497         int i, initcnt, node = first_online_node;
 498         struct irq_desc *desc;
 499
 500         init_irq_default_affinity();
 501
 502         /* Let arch update nr_irqs and return the nr of preallocated irqs */
 503         initcnt = arch_probe_nr_irqs();
 504         printk(KERN_INFO "NR_IRQS: %d, nr_irqs: %d, preallocated irqs: %d\n",
 505                NR_IRQS, nr_irqs, initcnt);
 506
 507         if (WARN_ON(nr_irqs > IRQ_BITMAP_BITS))
 508                 nr_irqs = IRQ_BITMAP_BITS;
 509
 510         if (WARN_ON(initcnt > IRQ_BITMAP_BITS))
 511                 initcnt = IRQ_BITMAP_BITS;
 512
 513         if (initcnt > nr_irqs)
 514                 nr_irqs = initcnt;
 515
 516         for (i = 0; i < initcnt; i++) {
 517                 desc = alloc_desc(i, node, 0, NULL, NULL);
 518                 set_bit(i, allocated_irqs);
 519                 irq_insert_desc(i, desc);
 520         }
 521         return arch_early_irq_init();
 522 }
 523
 524 #else /* !CONFIG_SPARSE_IRQ */
 525
 526 struct irq_desc irq_desc[NR_IRQS] __cacheline_aligned_in_smp = {
 527         [0 ... NR_IRQS-1] = {
 528                 .handle_irq     = handle_bad_irq,
 529                 .depth          = 1,
 530                 .lock           = __RAW_SPIN_LOCK_UNLOCKED(irq_desc->lock),
 531         }
 532 };
 533
 534 int __init early_irq_init(void)
 535 {
 536         int count, i, node = first_online_node;
 537         struct irq_desc *desc;
 538
 539         init_irq_default_affinity();
 540
 541         printk(KERN_INFO "NR_IRQS: %d\n", NR_IRQS);
 542
 543         desc = irq_desc;
 544         count = ARRAY_SIZE(irq_desc);
 545
 546         for (i = 0; i < count; i++) {
 547                 desc[i].kstat_irqs = alloc_percpu(unsigned int);
 548                 alloc_masks(&desc[i], node);
 549                 raw_spin_lock_init(&desc[i].lock);
 550                 lockdep_set_class(&desc[i].lock, &irq_desc_lock_class);
 551                 mutex_init(&desc[i].request_mutex);
 552                 desc_set_defaults(i, &desc[i], node, NULL, NULL);
 553         }
 554         return arch_early_irq_init();
 555 }
 556
 557 struct irq_desc *irq_to_desc(unsigned int irq)
 558 {
 559         return (irq < NR_IRQS) ? irq_desc + irq : NULL;
 560 }
 561 EXPORT_SYMBOL(irq_to_desc);
 562
 563 static void free_desc(unsigned int irq)
 564 {
 565         struct irq_desc *desc = irq_to_desc(irq);
 566         unsigned long flags;
 567
 568         raw_spin_lock_irqsave(&desc->lock, flags);
 569         desc_set_defaults(irq, desc, irq_desc_get_node(desc), NULL, NULL);
 570         raw_spin_unlock_irqrestore(&desc->lock, flags);
 571 }
 572
 573 static inline int alloc_descs(unsigned int start, unsigned int cnt, int node,
 574                               const struct cpumask *affinity,
 575                               struct module *owner)
 576 {
 577         u32 i;
 578
 579         for (i = 0; i < cnt; i++) {
 580                 struct irq_desc *desc = irq_to_desc(start + i);
 581
 582                 desc->owner = owner;
 583         }
 584         bitmap_set(allocated_irqs, start, cnt);
 585         return start;
 586 }
 587
 588 static int irq_expand_nr_irqs(unsigned int nr)
 589 {
 590         return -ENOMEM;
 591 }
 592
 593 void irq_mark_irq(unsigned int irq)
 594 {
 595         mutex_lock(&sparse_irq_lock);
 596         bitmap_set(allocated_irqs, irq, 1);
 597         mutex_unlock(&sparse_irq_lock);
 598 }
 599
 600 #ifdef CONFIG_GENERIC_IRQ_LEGACY
 601 void irq_init_desc(unsigned int irq)
 602 {
 603         free_desc(irq);
 604 }
 605 #endif
 606
 607 #endif /* !CONFIG_SPARSE_IRQ */
 608
 609 /**
 610  * generic_handle_irq - Invoke the handler for a particular irq
 611  * @irq:        The irq number to handle
 612  *
 613  */
 614 int generic_handle_irq(unsigned int irq)
 615 {
 616         struct irq_desc *desc = irq_to_desc(irq);
 617
 618         if (!desc)
 619                 return -EINVAL;
 620         generic_handle_irq_desc(desc);
 621         return 0;
 622 }
 623 EXPORT_SYMBOL_GPL(generic_handle_irq);
 624
 625 #ifdef CONFIG_HANDLE_DOMAIN_IRQ
 626 /**
 627  * __handle_domain_irq - Invoke the handler for a HW irq belonging to a domain
 628  * @domain:     The domain where to perform the lookup
 629  * @hwirq:      The HW irq number to convert to a logical one
 630  * @lookup:     Whether to perform the domain lookup or not
 631  * @regs:       Register file coming from the low-level handling code
 632  *
 633  * Returns:     0 on success, or -EINVAL if conversion has failed
 634  */
 635 int __handle_domain_irq(struct irq_domain *domain, unsigned int hwirq,
 636                         bool lookup, struct pt_regs *regs)
 637 {
 638         struct pt_regs *old_regs = set_irq_regs(regs);
 639         unsigned int irq = hwirq;
 640         int ret = 0;
 641
 642         irq_enter();
 643
 644 #ifdef CONFIG_IRQ_DOMAIN
 645         if (lookup)
 646                 irq = irq_find_mapping(domain, hwirq);
 647 #endif
 648
 649         /*
 650          * Some hardware gives randomly wrong interrupts.  Rather
 651          * than crashing, do something sensible.
 652          */
 653         if (unlikely(!irq || irq >= nr_irqs)) {
 654                 ack_bad_irq(irq);
 655                 ret = -EINVAL;
 656         } else {
 657                 generic_handle_irq(irq);
 658         }
 659
 660         irq_exit();
 661         set_irq_regs(old_regs);
 662         return ret;
 663 }
 664 #endif
 665
 666 /* Dynamic interrupt handling */
 667
 668 /**
 669  * irq_free_descs - free irq descriptors
 670  * @from:       Start of descriptor range
 671  * @cnt:        Number of consecutive irqs to free
 672  */
 673 void irq_free_descs(unsigned int from, unsigned int cnt)
 674 {
 675         int i;
 676
 677         if (from >= nr_irqs || (from + cnt) > nr_irqs)
 678                 return;
 679
 680         mutex_lock(&sparse_irq_lock);
 681         for (i = 0; i < cnt; i++)
 682                 free_desc(from + i);
 683
 684         bitmap_clear(allocated_irqs, from, cnt);
 685         mutex_unlock(&sparse_irq_lock);
 686 }
 687 EXPORT_SYMBOL_GPL(irq_free_descs);
 688
 689 /**
 690  * irq_alloc_descs - allocate and initialize a range of irq descriptors
 691  * @irq:        Allocate for specific irq number if irq >= 0
 692  * @from:       Start the search from this irq number
 693  * @cnt:        Number of consecutive irqs to allocate.
 694  * @node:       Preferred node on which the irq descriptor should be allocated
 695  * @owner:      Owning module (can be NULL)
 696  * @affinity:   Optional pointer to an affinity mask array of size @cnt which
 697  *              hints where the irq descriptors should be allocated and which
 698  *              default affinities to use
 699  *
 700  * Returns the first irq number or error code
 701  */
 702 int __ref
 703 __irq_alloc_descs(int irq, unsigned int from, unsigned int cnt, int node,
 704                   struct module *owner, const struct cpumask *affinity)
 705 {
 706         int start, ret;
 707
 708         if (!cnt)
 709                 return -EINVAL;
 710
 711         if (irq >= 0) {
 712                 if (from > irq)
 713                         return -EINVAL;
 714                 from = irq;
 715         } else {
 716                 /*
 717                  * For interrupts which are freely allocated the
 718                  * architecture can force a lower bound to the @from
 719                  * argument. x86 uses this to exclude the GSI space.
 720                  */
 721                 from = arch_dynirq_lower_bound(from);
 722         }
 723
 724         mutex_lock(&sparse_irq_lock);
 725
 726         start = bitmap_find_next_zero_area(allocated_irqs, IRQ_BITMAP_BITS,
 727                                            from, cnt, 0);
 728         ret = -EEXIST;
 729         if (irq >=0 && start != irq)
 730                 goto unlock;
 731
 732         if (start + cnt > nr_irqs) {
 733                 ret = irq_expand_nr_irqs(start + cnt);
 734                 if (ret)
 735                         goto unlock;
 736         }
 737         ret = alloc_descs(start, cnt, node, affinity, owner);
 738 unlock:
 739         mutex_unlock(&sparse_irq_lock);
 740         return ret;
 741 }
 742 EXPORT_SYMBOL_GPL(__irq_alloc_descs);
 743
 744 #ifdef CONFIG_GENERIC_IRQ_LEGACY_ALLOC_HWIRQ
 745 /**
 746  * irq_alloc_hwirqs - Allocate an irq descriptor and initialize the hardware
 747  * @cnt:        number of interrupts to allocate
 748  * @node:       node on which to allocate
 749  *
 750  * Returns an interrupt number > 0 or 0, if the allocation fails.
 751  */
 752 unsigned int irq_alloc_hwirqs(int cnt, int node)
 753 {
 754         int i, irq = __irq_alloc_descs(-1, 0, cnt, node, NULL, NULL);
 755
 756         if (irq < 0)
 757                 return 0;
 758
 759         for (i = irq; cnt > 0; i++, cnt--) {
 760                 if (arch_setup_hwirq(i, node))
 761                         goto err;
 762                 irq_clear_status_flags(i, _IRQ_NOREQUEST);
 763         }
 764         return irq;
 765
 766 err:
 767         for (i--; i >= irq; i--) {
 768                 irq_set_status_flags(i, _IRQ_NOREQUEST | _IRQ_NOPROBE);
 769                 arch_teardown_hwirq(i);
 770         }
 771         irq_free_descs(irq, cnt);
 772         return 0;
 773 }
 774 EXPORT_SYMBOL_GPL(irq_alloc_hwirqs);
 775
 776 /**
 777  * irq_free_hwirqs - Free irq descriptor and cleanup the hardware
 778  * @from:       Free from irq number
 779  * @cnt:        number of interrupts to free
 780  *
 781  */
 782 void irq_free_hwirqs(unsigned int from, int cnt)
 783 {
 784         int i, j;
 785
 786         for (i = from, j = cnt; j > 0; i++, j--) {
 787                 irq_set_status_flags(i, _IRQ_NOREQUEST | _IRQ_NOPROBE);
 788                 arch_teardown_hwirq(i);
 789         }
 790         irq_free_descs(from, cnt);
 791 }
 792 EXPORT_SYMBOL_GPL(irq_free_hwirqs);
 793 #endif
 794
 795 /**
 796  * irq_get_next_irq - get next allocated irq number
 797  * @offset:     where to start the search
 798  *
 799  * Returns next irq number after offset or nr_irqs if none is found.
 800  */
 801 unsigned int irq_get_next_irq(unsigned int offset)
 802 {
 803         return find_next_bit(allocated_irqs, nr_irqs, offset);
 804 }
 805
 806 struct irq_desc *
 807 __irq_get_desc_lock(unsigned int irq, unsigned long *flags, bool bus,
 808                     unsigned int check)
 809 {
 810         struct irq_desc *desc = irq_to_desc(irq);
 811
 812         if (desc) {
 813                 if (check & _IRQ_DESC_CHECK) {
 814                         if ((check & _IRQ_DESC_PERCPU) &&
 815                             !irq_settings_is_per_cpu_devid(desc))
 816                                 return NULL;
 817
 818                         if (!(check & _IRQ_DESC_PERCPU) &&
 819                             irq_settings_is_per_cpu_devid(desc))
 820                                 return NULL;
 821                 }
 822
 823                 if (bus)
 824                         chip_bus_lock(desc);
 825                 raw_spin_lock_irqsave(&desc->lock, *flags);
 826         }
 827         return desc;
 828 }
 829
 830 void __irq_put_desc_unlock(struct irq_desc *desc, unsigned long flags, bool bus)
 831 {
 832         raw_spin_unlock_irqrestore(&desc->lock, flags);
 833         if (bus)
 834                 chip_bus_sync_unlock(desc);
 835 }
 836
 837 int irq_set_percpu_devid_partition(unsigned int irq,
 838                                    const struct cpumask *affinity)
 839 {
 840         struct irq_desc *desc = irq_to_desc(irq);
 841
 842         if (!desc)
 843                 return -EINVAL;
 844
 845         if (desc->percpu_enabled)
 846                 return -EINVAL;
 847
 848         desc->percpu_enabled = kzalloc(sizeof(*desc->percpu_enabled), GFP_KERNEL);
 849
 850         if (!desc->percpu_enabled)
 851                 return -ENOMEM;
 852
 853         if (affinity)
 854                 desc->percpu_affinity = affinity;
 855         else
 856                 desc->percpu_affinity = cpu_possible_mask;
 857
 858         irq_set_percpu_devid_flags(irq);
 859         return 0;
 860 }
 861
 862 int irq_set_percpu_devid(unsigned int irq)
 863 {
 864         return irq_set_percpu_devid_partition(irq, NULL);
 865 }
 866
 867 int irq_get_percpu_devid_partition(unsigned int irq, struct cpumask *affinity)
 868 {
 869         struct irq_desc *desc = irq_to_desc(irq);
 870
 871         if (!desc || !desc->percpu_enabled)
 872                 return -EINVAL;
 873
 874         if (affinity)
 875                 cpumask_copy(affinity, desc->percpu_affinity);
 876
 877         return 0;
 878 }
 879
 880 void kstat_incr_irq_this_cpu(unsigned int irq)
 881 {
 882         kstat_incr_irqs_this_cpu(irq_to_desc(irq));
 883 }
 884
 885 /**
 886  * kstat_irqs_cpu - Get the statistics for an interrupt on a cpu
 887  * @irq:        The interrupt number
 888  * @cpu:        The cpu number
 889  *
 890  * Returns the sum of interrupt counts on @cpu since boot for
 891  * @irq. The caller must ensure that the interrupt is not removed
 892  * concurrently.
 893  */
 894 unsigned int kstat_irqs_cpu(unsigned int irq, int cpu)
 895 {
 896         struct irq_desc *desc = irq_to_desc(irq);
 897
 898         return desc && desc->kstat_irqs ?
 899                         *per_cpu_ptr(desc->kstat_irqs, cpu) : 0;
 900 }
 901
 902 /**
 903  * kstat_irqs - Get the statistics for an interrupt
 904  * @irq:        The interrupt number
 905  *
 906  * Returns the sum of interrupt counts on all cpus since boot for
 907  * @irq. The caller must ensure that the interrupt is not removed
 908  * concurrently.
 909  */
 910 unsigned int kstat_irqs(unsigned int irq)
 911 {
 912         struct irq_desc *desc = irq_to_desc(irq);
 913         unsigned int sum = 0;
 914         int cpu;
 915
 916         if (!desc || !desc->kstat_irqs)
 917                 return 0;
 918         if (!irq_settings_is_per_cpu_devid(desc) &&
 919             !irq_settings_is_per_cpu(desc))
 920             return desc->tot_count;
 921
 922         for_each_possible_cpu(cpu)
 923                 sum += *per_cpu_ptr(desc->kstat_irqs, cpu);
 924         return sum;
 925 }
 926
 927 /**
 928  * kstat_irqs_usr - Get the statistics for an interrupt
 929  * @irq:        The interrupt number
 930  *
 931  * Returns the sum of interrupt counts on all cpus since boot for
 932  * @irq. Contrary to kstat_irqs() this can be called from any
 933  * preemptible context. It's protected against concurrent removal of
 934  * an interrupt descriptor when sparse irqs are enabled.
 935  */
 936 unsigned int kstat_irqs_usr(unsigned int irq)
 937 {
 938         unsigned int sum;
 939
 940         irq_lock_sparse();
 941         sum = kstat_irqs(irq);
 942         irq_unlock_sparse();
 943         return sum;
 944 }