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         kobject_del(&desc->kobj);
 425         delete_irq_desc(irq);
 426
 427         /*
 428          * We free the descriptor, masks and stat fields via RCU. That
 429          * allows demultiplex interrupts to do rcu based management of
 430          * the child interrupts.
 431          */
 432         call_rcu(&desc->rcu, delayed_free_desc);
 433 }
 434
 435 static int alloc_descs(unsigned int start, unsigned int cnt, int node,
 436                        const struct cpumask *affinity, struct module *owner)
 437 {
 438         const struct cpumask *mask = NULL;
 439         struct irq_desc *desc;
 440         unsigned int flags;
 441         int i;
 442
 443         /* Validate affinity mask(s) */
 444         if (affinity) {
 445                 for (i = 0, mask = affinity; i < cnt; i++, mask++) {
 446                         if (cpumask_empty(mask))
 447                                 return -EINVAL;
 448                 }
 449         }
 450
 451         flags = affinity ? IRQD_AFFINITY_MANAGED : 0;
 452         mask = NULL;
 453
 454         for (i = 0; i < cnt; i++) {
 455                 if (affinity) {
 456                         node = cpu_to_node(cpumask_first(affinity));
 457                         mask = affinity;
 458                         affinity++;
 459                 }
 460                 desc = alloc_desc(start + i, node, flags, mask, owner);
 461                 if (!desc)
 462                         goto err;
 463                 irq_insert_desc(start + i, desc);
 464                 irq_sysfs_add(start + i, desc);
 465         }
 466         bitmap_set(allocated_irqs, start, cnt);
 467         return start;
 468
 469 err:
 470         for (i--; i >= 0; i--)
 471                 free_desc(start + i);
 472         return -ENOMEM;
 473 }
 474
 475 static int irq_expand_nr_irqs(unsigned int nr)
 476 {
 477         if (nr > IRQ_BITMAP_BITS)
 478                 return -ENOMEM;
 479         nr_irqs = nr;
 480         return 0;
 481 }
 482
 483 int __init early_irq_init(void)
 484 {
 485         int i, initcnt, node = first_online_node;
 486         struct irq_desc *desc;
 487
 488         init_irq_default_affinity();
 489
 490         /* Let arch update nr_irqs and return the nr of preallocated irqs */
 491         initcnt = arch_probe_nr_irqs();
 492         printk(KERN_INFO "NR_IRQS: %d, nr_irqs: %d, preallocated irqs: %d\n",
 493                NR_IRQS, nr_irqs, initcnt);
 494
 495         if (WARN_ON(nr_irqs > IRQ_BITMAP_BITS))
 496                 nr_irqs = IRQ_BITMAP_BITS;
 497
 498         if (WARN_ON(initcnt > IRQ_BITMAP_BITS))
 499                 initcnt = IRQ_BITMAP_BITS;
 500
 501         if (initcnt > nr_irqs)
 502                 nr_irqs = initcnt;
 503
 504         for (i = 0; i < initcnt; i++) {
 505                 desc = alloc_desc(i, node, 0, NULL, NULL);
 506                 set_bit(i, allocated_irqs);
 507                 irq_insert_desc(i, desc);
 508         }
 509         return arch_early_irq_init();
 510 }
 511
 512 #else /* !CONFIG_SPARSE_IRQ */
 513
 514 struct irq_desc irq_desc[NR_IRQS] __cacheline_aligned_in_smp = {
 515         [0 ... NR_IRQS-1] = {
 516                 .handle_irq     = handle_bad_irq,
 517                 .depth          = 1,
 518                 .lock           = __RAW_SPIN_LOCK_UNLOCKED(irq_desc->lock),
 519         }
 520 };
 521
 522 int __init early_irq_init(void)
 523 {
 524         int count, i, node = first_online_node;
 525         struct irq_desc *desc;
 526
 527         init_irq_default_affinity();
 528
 529         printk(KERN_INFO "NR_IRQS: %d\n", NR_IRQS);
 530
 531         desc = irq_desc;
 532         count = ARRAY_SIZE(irq_desc);
 533
 534         for (i = 0; i < count; i++) {
 535                 desc[i].kstat_irqs = alloc_percpu(unsigned int);
 536                 alloc_masks(&desc[i], node);
 537                 raw_spin_lock_init(&desc[i].lock);
 538                 lockdep_set_class(&desc[i].lock, &irq_desc_lock_class);
 539                 desc_set_defaults(i, &desc[i], node, NULL, NULL);
 540         }
 541         return arch_early_irq_init();
 542 }
 543
 544 struct irq_desc *irq_to_desc(unsigned int irq)
 545 {
 546         return (irq < NR_IRQS) ? irq_desc + irq : NULL;
 547 }
 548 EXPORT_SYMBOL(irq_to_desc);
 549
 550 static void free_desc(unsigned int irq)
 551 {
 552         struct irq_desc *desc = irq_to_desc(irq);
 553         unsigned long flags;
 554
 555         raw_spin_lock_irqsave(&desc->lock, flags);
 556         desc_set_defaults(irq, desc, irq_desc_get_node(desc), NULL, NULL);
 557         raw_spin_unlock_irqrestore(&desc->lock, flags);
 558 }
 559
 560 static inline int alloc_descs(unsigned int start, unsigned int cnt, int node,
 561                               const struct cpumask *affinity,
 562                               struct module *owner)
 563 {
 564         u32 i;
 565
 566         for (i = 0; i < cnt; i++) {
 567                 struct irq_desc *desc = irq_to_desc(start + i);
 568
 569                 desc->owner = owner;
 570         }
 571         bitmap_set(allocated_irqs, start, cnt);
 572         return start;
 573 }
 574
 575 static int irq_expand_nr_irqs(unsigned int nr)
 576 {
 577         return -ENOMEM;
 578 }
 579
 580 void irq_mark_irq(unsigned int irq)
 581 {
 582         mutex_lock(&sparse_irq_lock);
 583         bitmap_set(allocated_irqs, irq, 1);
 584         mutex_unlock(&sparse_irq_lock);
 585 }
 586
 587 #ifdef CONFIG_GENERIC_IRQ_LEGACY
 588 void irq_init_desc(unsigned int irq)
 589 {
 590         free_desc(irq);
 591 }
 592 #endif
 593
 594 #endif /* !CONFIG_SPARSE_IRQ */
 595
 596 /**
 597  * generic_handle_irq - Invoke the handler for a particular irq
 598  * @irq:        The irq number to handle
 599  *
 600  */
 601 int generic_handle_irq(unsigned int irq)
 602 {
 603         struct irq_desc *desc = irq_to_desc(irq);
 604
 605         if (!desc)
 606                 return -EINVAL;
 607         generic_handle_irq_desc(desc);
 608         return 0;
 609 }
 610 EXPORT_SYMBOL_GPL(generic_handle_irq);
 611
 612 #ifdef CONFIG_HANDLE_DOMAIN_IRQ
 613 /**
 614  * __handle_domain_irq - Invoke the handler for a HW irq belonging to a domain
 615  * @domain:     The domain where to perform the lookup
 616  * @hwirq:      The HW irq number to convert to a logical one
 617  * @lookup:     Whether to perform the domain lookup or not
 618  * @regs:       Register file coming from the low-level handling code
 619  *
 620  * Returns:     0 on success, or -EINVAL if conversion has failed
 621  */
 622 int __handle_domain_irq(struct irq_domain *domain, unsigned int hwirq,
 623                         bool lookup, struct pt_regs *regs)
 624 {
 625         struct pt_regs *old_regs = set_irq_regs(regs);
 626         unsigned int irq = hwirq;
 627         int ret = 0;
 628
 629         irq_enter();
 630
 631 #ifdef CONFIG_IRQ_DOMAIN
 632         if (lookup)
 633                 irq = irq_find_mapping(domain, hwirq);
 634 #endif
 635
 636         /*
 637          * Some hardware gives randomly wrong interrupts.  Rather
 638          * than crashing, do something sensible.
 639          */
 640         if (unlikely(!irq || irq >= nr_irqs)) {
 641                 ack_bad_irq(irq);
 642                 ret = -EINVAL;
 643         } else {
 644                 generic_handle_irq(irq);
 645         }
 646
 647         irq_exit();
 648         set_irq_regs(old_regs);
 649         return ret;
 650 }
 651 #endif
 652
 653 /* Dynamic interrupt handling */
 654
 655 /**
 656  * irq_free_descs - free irq descriptors
 657  * @from:       Start of descriptor range
 658  * @cnt:        Number of consecutive irqs to free
 659  */
 660 void irq_free_descs(unsigned int from, unsigned int cnt)
 661 {
 662         int i;
 663
 664         if (from >= nr_irqs || (from + cnt) > nr_irqs)
 665                 return;
 666
 667         mutex_lock(&sparse_irq_lock);
 668         for (i = 0; i < cnt; i++)
 669                 free_desc(from + i);
 670
 671         bitmap_clear(allocated_irqs, from, cnt);
 672         mutex_unlock(&sparse_irq_lock);
 673 }
 674 EXPORT_SYMBOL_GPL(irq_free_descs);
 675
 676 /**
 677  * irq_alloc_descs - allocate and initialize a range of irq descriptors
 678  * @irq:        Allocate for specific irq number if irq >= 0
 679  * @from:       Start the search from this irq number
 680  * @cnt:        Number of consecutive irqs to allocate.
 681  * @node:       Preferred node on which the irq descriptor should be allocated
 682  * @owner:      Owning module (can be NULL)
 683  * @affinity:   Optional pointer to an affinity mask array of size @cnt which
 684  *              hints where the irq descriptors should be allocated and which
 685  *              default affinities to use
 686  *
 687  * Returns the first irq number or error code
 688  */
 689 int __ref
 690 __irq_alloc_descs(int irq, unsigned int from, unsigned int cnt, int node,
 691                   struct module *owner, const struct cpumask *affinity)
 692 {
 693         int start, ret;
 694
 695         if (!cnt)
 696                 return -EINVAL;
 697
 698         if (irq >= 0) {
 699                 if (from > irq)
 700                         return -EINVAL;
 701                 from = irq;
 702         } else {
 703                 /*
 704                  * For interrupts which are freely allocated the
 705                  * architecture can force a lower bound to the @from
 706                  * argument. x86 uses this to exclude the GSI space.
 707                  */
 708                 from = arch_dynirq_lower_bound(from);
 709         }
 710
 711         mutex_lock(&sparse_irq_lock);
 712
 713         start = bitmap_find_next_zero_area(allocated_irqs, IRQ_BITMAP_BITS,
 714                                            from, cnt, 0);
 715         ret = -EEXIST;
 716         if (irq >=0 && start != irq)
 717                 goto unlock;
 718
 719         if (start + cnt > nr_irqs) {
 720                 ret = irq_expand_nr_irqs(start + cnt);
 721                 if (ret)
 722                         goto unlock;
 723         }
 724         ret = alloc_descs(start, cnt, node, affinity, owner);
 725 unlock:
 726         mutex_unlock(&sparse_irq_lock);
 727         return ret;
 728 }
 729 EXPORT_SYMBOL_GPL(__irq_alloc_descs);
 730
 731 #ifdef CONFIG_GENERIC_IRQ_LEGACY_ALLOC_HWIRQ
 732 /**
 733  * irq_alloc_hwirqs - Allocate an irq descriptor and initialize the hardware
 734  * @cnt:        number of interrupts to allocate
 735  * @node:       node on which to allocate
 736  *
 737  * Returns an interrupt number > 0 or 0, if the allocation fails.
 738  */
 739 unsigned int irq_alloc_hwirqs(int cnt, int node)
 740 {
 741         int i, irq = __irq_alloc_descs(-1, 0, cnt, node, NULL, NULL);
 742
 743         if (irq < 0)
 744                 return 0;
 745
 746         for (i = irq; cnt > 0; i++, cnt--) {
 747                 if (arch_setup_hwirq(i, node))
 748                         goto err;
 749                 irq_clear_status_flags(i, _IRQ_NOREQUEST);
 750         }
 751         return irq;
 752
 753 err:
 754         for (i--; i >= irq; i--) {
 755                 irq_set_status_flags(i, _IRQ_NOREQUEST | _IRQ_NOPROBE);
 756                 arch_teardown_hwirq(i);
 757         }
 758         irq_free_descs(irq, cnt);
 759         return 0;
 760 }
 761 EXPORT_SYMBOL_GPL(irq_alloc_hwirqs);
 762
 763 /**
 764  * irq_free_hwirqs - Free irq descriptor and cleanup the hardware
 765  * @from:       Free from irq number
 766  * @cnt:        number of interrupts to free
 767  *
 768  */
 769 void irq_free_hwirqs(unsigned int from, int cnt)
 770 {
 771         int i, j;
 772
 773         for (i = from, j = cnt; j > 0; i++, j--) {
 774                 irq_set_status_flags(i, _IRQ_NOREQUEST | _IRQ_NOPROBE);
 775                 arch_teardown_hwirq(i);
 776         }
 777         irq_free_descs(from, cnt);
 778 }
 779 EXPORT_SYMBOL_GPL(irq_free_hwirqs);
 780 #endif
 781
 782 /**
 783  * irq_get_next_irq - get next allocated irq number
 784  * @offset:     where to start the search
 785  *
 786  * Returns next irq number after offset or nr_irqs if none is found.
 787  */
 788 unsigned int irq_get_next_irq(unsigned int offset)
 789 {
 790         return find_next_bit(allocated_irqs, nr_irqs, offset);
 791 }
 792
 793 struct irq_desc *
 794 __irq_get_desc_lock(unsigned int irq, unsigned long *flags, bool bus,
 795                     unsigned int check)
 796 {
 797         struct irq_desc *desc = irq_to_desc(irq);
 798
 799         if (desc) {
 800                 if (check & _IRQ_DESC_CHECK) {
 801                         if ((check & _IRQ_DESC_PERCPU) &&
 802                             !irq_settings_is_per_cpu_devid(desc))
 803                                 return NULL;
 804
 805                         if (!(check & _IRQ_DESC_PERCPU) &&
 806                             irq_settings_is_per_cpu_devid(desc))
 807                                 return NULL;
 808                 }
 809
 810                 if (bus)
 811                         chip_bus_lock(desc);
 812                 raw_spin_lock_irqsave(&desc->lock, *flags);
 813         }
 814         return desc;
 815 }
 816
 817 void __irq_put_desc_unlock(struct irq_desc *desc, unsigned long flags, bool bus)
 818 {
 819         raw_spin_unlock_irqrestore(&desc->lock, flags);
 820         if (bus)
 821                 chip_bus_sync_unlock(desc);
 822 }
 823
 824 int irq_set_percpu_devid_partition(unsigned int irq,
 825                                    const struct cpumask *affinity)
 826 {
 827         struct irq_desc *desc = irq_to_desc(irq);
 828
 829         if (!desc)
 830                 return -EINVAL;
 831
 832         if (desc->percpu_enabled)
 833                 return -EINVAL;
 834
 835         desc->percpu_enabled = kzalloc(sizeof(*desc->percpu_enabled), GFP_KERNEL);
 836
 837         if (!desc->percpu_enabled)
 838                 return -ENOMEM;
 839
 840         if (affinity)
 841                 desc->percpu_affinity = affinity;
 842         else
 843                 desc->percpu_affinity = cpu_possible_mask;
 844
 845         irq_set_percpu_devid_flags(irq);
 846         return 0;
 847 }
 848
 849 int irq_set_percpu_devid(unsigned int irq)
 850 {
 851         return irq_set_percpu_devid_partition(irq, NULL);
 852 }
 853
 854 int irq_get_percpu_devid_partition(unsigned int irq, struct cpumask *affinity)
 855 {
 856         struct irq_desc *desc = irq_to_desc(irq);
 857
 858         if (!desc || !desc->percpu_enabled)
 859                 return -EINVAL;
 860
 861         if (affinity)
 862                 cpumask_copy(affinity, desc->percpu_affinity);
 863
 864         return 0;
 865 }
 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 }