kernel/irq/irqdesc.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * Copyright (C) 1992, 1998-2006 Linus Torvalds, Ingo Molnar
   4  * Copyright (C) 2005-2006, Thomas Gleixner, Russell King
   5  *
   6  * This file contains the interrupt descriptor management code. Detailed
   7  * information is available in Documentation/core-api/genericirq.rst
   8  *
   9  */
  10 #include <linux/irq.h>
  11 #include <linux/slab.h>
  12 #include <linux/export.h>
  13 #include <linux/interrupt.h>
  14 #include <linux/kernel_stat.h>
  15 #include <linux/radix-tree.h>
  16 #include <linux/bitmap.h>
  17 #include <linux/irqdomain.h>
  18 #include <linux/sysfs.h>
  19
  20 #include "internals.h"
  21
  22 /*
  23  * lockdep: we want to handle all irq_desc locks as a single lock-class:
  24  */
  25 static struct lock_class_key irq_desc_lock_class;
  26
  27 #if defined(CONFIG_SMP)
  28 static int __init irq_affinity_setup(char *str)
  29 {
  30         alloc_bootmem_cpumask_var(&irq_default_affinity);
  31         cpulist_parse(str, irq_default_affinity);
  32         /*
  33          * Set at least the boot cpu. We don't want to end up with
  34          * bugreports caused by random comandline masks
  35          */
  36         cpumask_set_cpu(smp_processor_id(), irq_default_affinity);
  37         return 1;
  38 }
  39 __setup("irqaffinity=", irq_affinity_setup);
  40
  41 static void __init init_irq_default_affinity(void)
  42 {
  43         if (!cpumask_available(irq_default_affinity))
  44                 zalloc_cpumask_var(&irq_default_affinity, GFP_NOWAIT);
  45         if (cpumask_empty(irq_default_affinity))
  46                 cpumask_setall(irq_default_affinity);
  47 }
  48 #else
  49 static void __init init_irq_default_affinity(void)
  50 {
  51 }
  52 #endif
  53
  54 #ifdef CONFIG_SMP
  55 static int alloc_masks(struct irq_desc *desc, int node)
  56 {
  57         if (!zalloc_cpumask_var_node(&desc->irq_common_data.affinity,
  58                                      GFP_KERNEL, node))
  59                 return -ENOMEM;
  60
  61 #ifdef CONFIG_GENERIC_IRQ_EFFECTIVE_AFF_MASK
  62         if (!zalloc_cpumask_var_node(&desc->irq_common_data.effective_affinity,
  63                                      GFP_KERNEL, node)) {
  64                 free_cpumask_var(desc->irq_common_data.affinity);
  65                 return -ENOMEM;
  66         }
  67 #endif
  68
  69 #ifdef CONFIG_GENERIC_PENDING_IRQ
  70         if (!zalloc_cpumask_var_node(&desc->pending_mask, GFP_KERNEL, node)) {
  71 #ifdef CONFIG_GENERIC_IRQ_EFFECTIVE_AFF_MASK
  72                 free_cpumask_var(desc->irq_common_data.effective_affinity);
  73 #endif
  74                 free_cpumask_var(desc->irq_common_data.affinity);
  75                 return -ENOMEM;
  76         }
  77 #endif
  78         return 0;
  79 }
  80
  81 static void desc_smp_init(struct irq_desc *desc, int node,
  82                           const struct cpumask *affinity)
  83 {
  84         if (!affinity)
  85                 affinity = irq_default_affinity;
  86         cpumask_copy(desc->irq_common_data.affinity, affinity);
  87
  88 #ifdef CONFIG_GENERIC_PENDING_IRQ
  89         cpumask_clear(desc->pending_mask);
  90 #endif
  91 #ifdef CONFIG_NUMA
  92         desc->irq_common_data.node = node;
  93 #endif
  94 }
  95
  96 #else
  97 static inline int
  98 alloc_masks(struct irq_desc *desc, int node) { return 0; }
  99 static inline void
 100 desc_smp_init(struct irq_desc *desc, int node, const struct cpumask *affinity) { }
 101 #endif
 102
 103 static void desc_set_defaults(unsigned int irq, struct irq_desc *desc, int node,
 104                               const struct cpumask *affinity, struct module *owner)
 105 {
 106         int cpu;
 107
 108         desc->irq_common_data.handler_data = NULL;
 109         desc->irq_common_data.msi_desc = NULL;
 110
 111         desc->irq_data.common = &desc->irq_common_data;
 112         desc->irq_data.irq = irq;
 113         desc->irq_data.chip = &no_irq_chip;
 114         desc->irq_data.chip_data = NULL;
 115         irq_settings_clr_and_set(desc, ~0, _IRQ_DEFAULT_INIT_FLAGS);
 116         irqd_set(&desc->irq_data, IRQD_IRQ_DISABLED);
 117         irqd_set(&desc->irq_data, IRQD_IRQ_MASKED);
 118         desc->handle_irq = handle_bad_irq;
 119         desc->depth = 1;
 120         desc->irq_count = 0;
 121         desc->irqs_unhandled = 0;
 122         desc->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 wakeup_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         ret = sprintf(buf, "%s\n",
 221                       irqd_is_wakeup_set(&desc->irq_data) ? "enabled" : "disabled");
 222         raw_spin_unlock_irq(&desc->lock);
 223
 224         return ret;
 225
 226 }
 227 IRQ_ATTR_RO(wakeup);
 228
 229 static ssize_t name_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         ssize_t ret = 0;
 234
 235         raw_spin_lock_irq(&desc->lock);
 236         if (desc->name)
 237                 ret = scnprintf(buf, PAGE_SIZE, "%s\n", desc->name);
 238         raw_spin_unlock_irq(&desc->lock);
 239
 240         return ret;
 241 }
 242 IRQ_ATTR_RO(name);
 243
 244 static ssize_t actions_show(struct kobject *kobj,
 245                             struct kobj_attribute *attr, char *buf)
 246 {
 247         struct irq_desc *desc = container_of(kobj, struct irq_desc, kobj);
 248         struct irqaction *action;
 249         ssize_t ret = 0;
 250         char *p = "";
 251
 252         raw_spin_lock_irq(&desc->lock);
 253         for (action = desc->action; action != NULL; action = action->next) {
 254                 ret += scnprintf(buf + ret, PAGE_SIZE - ret, "%s%s",
 255                                  p, action->name);
 256                 p = ",";
 257         }
 258         raw_spin_unlock_irq(&desc->lock);
 259
 260         if (ret)
 261                 ret += scnprintf(buf + ret, PAGE_SIZE - ret, "\n");
 262
 263         return ret;
 264 }
 265 IRQ_ATTR_RO(actions);
 266
 267 static struct attribute *irq_attrs[] = {
 268         &per_cpu_count_attr.attr,
 269         &chip_name_attr.attr,
 270         &hwirq_attr.attr,
 271         &type_attr.attr,
 272         &wakeup_attr.attr,
 273         &name_attr.attr,
 274         &actions_attr.attr,
 275         NULL
 276 };
 277
 278 static struct kobj_type irq_kobj_type = {
 279         .release        = irq_kobj_release,
 280         .sysfs_ops      = &kobj_sysfs_ops,
 281         .default_attrs  = irq_attrs,
 282 };
 283
 284 static void irq_sysfs_add(int irq, struct irq_desc *desc)
 285 {
 286         if (irq_kobj_base) {
 287                 /*
 288                  * Continue even in case of failure as this is nothing
 289                  * crucial.
 290                  */
 291                 if (kobject_add(&desc->kobj, irq_kobj_base, "%d", irq))
 292                         pr_warn("Failed to add kobject for irq %d\n", irq);
 293         }
 294 }
 295
 296 static int __init irq_sysfs_init(void)
 297 {
 298         struct irq_desc *desc;
 299         int irq;
 300
 301         /* Prevent concurrent irq alloc/free */
 302         irq_lock_sparse();
 303
 304         irq_kobj_base = kobject_create_and_add("irq", kernel_kobj);
 305         if (!irq_kobj_base) {
 306                 irq_unlock_sparse();
 307                 return -ENOMEM;
 308         }
 309
 310         /* Add the already allocated interrupts */
 311         for_each_irq_desc(irq, desc)
 312                 irq_sysfs_add(irq, desc);
 313         irq_unlock_sparse();
 314
 315         return 0;
 316 }
 317 postcore_initcall(irq_sysfs_init);
 318
 319 #else /* !CONFIG_SYSFS */
 320
 321 static struct kobj_type irq_kobj_type = {
 322         .release        = irq_kobj_release,
 323 };
 324
 325 static void irq_sysfs_add(int irq, struct irq_desc *desc) {}
 326
 327 #endif /* CONFIG_SYSFS */
 328
 329 static RADIX_TREE(irq_desc_tree, GFP_KERNEL);
 330
 331 static void irq_insert_desc(unsigned int irq, struct irq_desc *desc)
 332 {
 333         radix_tree_insert(&irq_desc_tree, irq, desc);
 334 }
 335
 336 struct irq_desc *irq_to_desc(unsigned int irq)
 337 {
 338         return radix_tree_lookup(&irq_desc_tree, irq);
 339 }
 340 EXPORT_SYMBOL(irq_to_desc);
 341
 342 static void delete_irq_desc(unsigned int irq)
 343 {
 344         radix_tree_delete(&irq_desc_tree, irq);
 345 }
 346
 347 #ifdef CONFIG_SMP
 348 static void free_masks(struct irq_desc *desc)
 349 {
 350 #ifdef CONFIG_GENERIC_PENDING_IRQ
 351         free_cpumask_var(desc->pending_mask);
 352 #endif
 353         free_cpumask_var(desc->irq_common_data.affinity);
 354 #ifdef CONFIG_GENERIC_IRQ_EFFECTIVE_AFF_MASK
 355         free_cpumask_var(desc->irq_common_data.effective_affinity);
 356 #endif
 357 }
 358 #else
 359 static inline void free_masks(struct irq_desc *desc) { }
 360 #endif
 361
 362 void irq_lock_sparse(void)
 363 {
 364         mutex_lock(&sparse_irq_lock);
 365 }
 366
 367 void irq_unlock_sparse(void)
 368 {
 369         mutex_unlock(&sparse_irq_lock);
 370 }
 371
 372 static struct irq_desc *alloc_desc(int irq, int node, unsigned int flags,
 373                                    const struct cpumask *affinity,
 374                                    struct module *owner)
 375 {
 376         struct irq_desc *desc;
 377
 378         desc = kzalloc_node(sizeof(*desc), GFP_KERNEL, node);
 379         if (!desc)
 380                 return NULL;
 381         /* allocate based on nr_cpu_ids */
 382         desc->kstat_irqs = alloc_percpu(unsigned int);
 383         if (!desc->kstat_irqs)
 384                 goto err_desc;
 385
 386         if (alloc_masks(desc, node))
 387                 goto err_kstat;
 388
 389         raw_spin_lock_init(&desc->lock);
 390         lockdep_set_class(&desc->lock, &irq_desc_lock_class);
 391         mutex_init(&desc->request_mutex);
 392         init_rcu_head(&desc->rcu);
 393
 394         desc_set_defaults(irq, desc, node, affinity, owner);
 395         irqd_set(&desc->irq_data, flags);
 396         kobject_init(&desc->kobj, &irq_kobj_type);
 397
 398         return desc;
 399
 400 err_kstat:
 401         free_percpu(desc->kstat_irqs);
 402 err_desc:
 403         kfree(desc);
 404         return NULL;
 405 }
 406
 407 static void irq_kobj_release(struct kobject *kobj)
 408 {
 409         struct irq_desc *desc = container_of(kobj, struct irq_desc, kobj);
 410
 411         free_masks(desc);
 412         free_percpu(desc->kstat_irqs);
 413         kfree(desc);
 414 }
 415
 416 static void delayed_free_desc(struct rcu_head *rhp)
 417 {
 418         struct irq_desc *desc = container_of(rhp, struct irq_desc, rcu);
 419
 420         kobject_put(&desc->kobj);
 421 }
 422
 423 static void free_desc(unsigned int irq)
 424 {
 425         struct irq_desc *desc = irq_to_desc(irq);
 426
 427         irq_remove_debugfs_entry(desc);
 428         unregister_irq_proc(irq, desc);
 429
 430         /*
 431          * sparse_irq_lock protects also show_interrupts() and
 432          * kstat_irq_usr(). Once we deleted the descriptor from the
 433          * sparse tree we can free it. Access in proc will fail to
 434          * lookup the descriptor.
 435          *
 436          * The sysfs entry must be serialized against a concurrent
 437          * irq_sysfs_init() as well.
 438          */
 439         kobject_del(&desc->kobj);
 440         delete_irq_desc(irq);
 441
 442         /*
 443          * We free the descriptor, masks and stat fields via RCU. That
 444          * allows demultiplex interrupts to do rcu based management of
 445          * the child interrupts.
 446          */
 447         call_rcu(&desc->rcu, delayed_free_desc);
 448 }
 449
 450 static int alloc_descs(unsigned int start, unsigned int cnt, int node,
 451                        const struct cpumask *affinity, struct module *owner)
 452 {
 453         const struct cpumask *mask = NULL;
 454         struct irq_desc *desc;
 455         unsigned int flags;
 456         int i;
 457
 458         /* Validate affinity mask(s) */
 459         if (affinity) {
 460                 for (i = 0, mask = affinity; i < cnt; i++, mask++) {
 461                         if (cpumask_empty(mask))
 462                                 return -EINVAL;
 463                 }
 464         }
 465
 466         flags = affinity ? IRQD_AFFINITY_MANAGED | IRQD_MANAGED_SHUTDOWN : 0;
 467         mask = NULL;
 468
 469         for (i = 0; i < cnt; i++) {
 470                 if (affinity) {
 471                         node = cpu_to_node(cpumask_first(affinity));
 472                         mask = affinity;
 473                         affinity++;
 474                 }
 475                 desc = alloc_desc(start + i, node, flags, mask, owner);
 476                 if (!desc)
 477                         goto err;
 478                 irq_insert_desc(start + i, desc);
 479                 irq_sysfs_add(start + i, desc);
 480                 irq_add_debugfs_entry(start + i, desc);
 481         }
 482         bitmap_set(allocated_irqs, start, cnt);
 483         return start;
 484
 485 err:
 486         for (i--; i >= 0; i--)
 487                 free_desc(start + i);
 488         return -ENOMEM;
 489 }
 490
 491 static int irq_expand_nr_irqs(unsigned int nr)
 492 {
 493         if (nr > IRQ_BITMAP_BITS)
 494                 return -ENOMEM;
 495         nr_irqs = nr;
 496         return 0;
 497 }
 498
 499 int __init early_irq_init(void)
 500 {
 501         int i, initcnt, node = first_online_node;
 502         struct irq_desc *desc;
 503
 504         init_irq_default_affinity();
 505
 506         /* Let arch update nr_irqs and return the nr of preallocated irqs */
 507         initcnt = arch_probe_nr_irqs();
 508         printk(KERN_INFO "NR_IRQS: %d, nr_irqs: %d, preallocated irqs: %d\n",
 509                NR_IRQS, nr_irqs, initcnt);
 510
 511         if (WARN_ON(nr_irqs > IRQ_BITMAP_BITS))
 512                 nr_irqs = IRQ_BITMAP_BITS;
 513
 514         if (WARN_ON(initcnt > IRQ_BITMAP_BITS))
 515                 initcnt = IRQ_BITMAP_BITS;
 516
 517         if (initcnt > nr_irqs)
 518                 nr_irqs = initcnt;
 519
 520         for (i = 0; i < initcnt; i++) {
 521                 desc = alloc_desc(i, node, 0, NULL, NULL);
 522                 set_bit(i, allocated_irqs);
 523                 irq_insert_desc(i, desc);
 524         }
 525         return arch_early_irq_init();
 526 }
 527
 528 #else /* !CONFIG_SPARSE_IRQ */
 529
 530 struct irq_desc irq_desc[NR_IRQS] __cacheline_aligned_in_smp = {
 531         [0 ... NR_IRQS-1] = {
 532                 .handle_irq     = handle_bad_irq,
 533                 .depth          = 1,
 534                 .lock           = __RAW_SPIN_LOCK_UNLOCKED(irq_desc->lock),
 535         }
 536 };
 537
 538 int __init early_irq_init(void)
 539 {
 540         int count, i, node = first_online_node;
 541         struct irq_desc *desc;
 542
 543         init_irq_default_affinity();
 544
 545         printk(KERN_INFO "NR_IRQS: %d\n", NR_IRQS);
 546
 547         desc = irq_desc;
 548         count = ARRAY_SIZE(irq_desc);
 549
 550         for (i = 0; i < count; i++) {
 551                 desc[i].kstat_irqs = alloc_percpu(unsigned int);
 552                 alloc_masks(&desc[i], node);
 553                 raw_spin_lock_init(&desc[i].lock);
 554                 lockdep_set_class(&desc[i].lock, &irq_desc_lock_class);
 555                 desc_set_defaults(i, &desc[i], node, NULL, NULL);
 556         }
 557         return arch_early_irq_init();
 558 }
 559
 560 struct irq_desc *irq_to_desc(unsigned int irq)
 561 {
 562         return (irq < NR_IRQS) ? irq_desc + irq : NULL;
 563 }
 564 EXPORT_SYMBOL(irq_to_desc);
 565
 566 static void free_desc(unsigned int irq)
 567 {
 568         struct irq_desc *desc = irq_to_desc(irq);
 569         unsigned long flags;
 570
 571         raw_spin_lock_irqsave(&desc->lock, flags);
 572         desc_set_defaults(irq, desc, irq_desc_get_node(desc), NULL, NULL);
 573         raw_spin_unlock_irqrestore(&desc->lock, flags);
 574 }
 575
 576 static inline int alloc_descs(unsigned int start, unsigned int cnt, int node,
 577                               const struct cpumask *affinity,
 578                               struct module *owner)
 579 {
 580         u32 i;
 581
 582         for (i = 0; i < cnt; i++) {
 583                 struct irq_desc *desc = irq_to_desc(start + i);
 584
 585                 desc->owner = owner;
 586         }
 587         bitmap_set(allocated_irqs, start, cnt);
 588         return start;
 589 }
 590
 591 static int irq_expand_nr_irqs(unsigned int nr)
 592 {
 593         return -ENOMEM;
 594 }
 595
 596 void irq_mark_irq(unsigned int irq)
 597 {
 598         mutex_lock(&sparse_irq_lock);
 599         bitmap_set(allocated_irqs, irq, 1);
 600         mutex_unlock(&sparse_irq_lock);
 601 }
 602
 603 #ifdef CONFIG_GENERIC_IRQ_LEGACY
 604 void irq_init_desc(unsigned int irq)
 605 {
 606         free_desc(irq);
 607 }
 608 #endif
 609
 610 #endif /* !CONFIG_SPARSE_IRQ */
 611
 612 /**
 613  * generic_handle_irq - Invoke the handler for a particular irq
 614  * @irq:        The irq number to handle
 615  *
 616  */
 617 int generic_handle_irq(unsigned int irq)
 618 {
 619         struct irq_desc *desc = irq_to_desc(irq);
 620
 621         if (!desc)
 622                 return -EINVAL;
 623         generic_handle_irq_desc(desc);
 624         return 0;
 625 }
 626 EXPORT_SYMBOL_GPL(generic_handle_irq);
 627
 628 #ifdef CONFIG_HANDLE_DOMAIN_IRQ
 629 /**
 630  * __handle_domain_irq - Invoke the handler for a HW irq belonging to a domain
 631  * @domain:     The domain where to perform the lookup
 632  * @hwirq:      The HW irq number to convert to a logical one
 633  * @lookup:     Whether to perform the domain lookup or not
 634  * @regs:       Register file coming from the low-level handling code
 635  *
 636  * Returns:     0 on success, or -EINVAL if conversion has failed
 637  */
 638 int __handle_domain_irq(struct irq_domain *domain, unsigned int hwirq,
 639                         bool lookup, struct pt_regs *regs)
 640 {
 641         struct pt_regs *old_regs = set_irq_regs(regs);
 642         unsigned int irq = hwirq;
 643         int ret = 0;
 644
 645         irq_enter();
 646
 647 #ifdef CONFIG_IRQ_DOMAIN
 648         if (lookup)
 649                 irq = irq_find_mapping(domain, hwirq);
 650 #endif
 651
 652         /*
 653          * Some hardware gives randomly wrong interrupts.  Rather
 654          * than crashing, do something sensible.
 655          */
 656         if (unlikely(!irq || irq >= nr_irqs)) {
 657                 ack_bad_irq(irq);
 658                 ret = -EINVAL;
 659         } else {
 660                 generic_handle_irq(irq);
 661         }
 662
 663         irq_exit();
 664         set_irq_regs(old_regs);
 665         return ret;
 666 }
 667 #endif
 668
 669 /* Dynamic interrupt handling */
 670
 671 /**
 672  * irq_free_descs - free irq descriptors
 673  * @from:       Start of descriptor range
 674  * @cnt:        Number of consecutive irqs to free
 675  */
 676 void irq_free_descs(unsigned int from, unsigned int cnt)
 677 {
 678         int i;
 679
 680         if (from >= nr_irqs || (from + cnt) > nr_irqs)
 681                 return;
 682
 683         mutex_lock(&sparse_irq_lock);
 684         for (i = 0; i < cnt; i++)
 685                 free_desc(from + i);
 686
 687         bitmap_clear(allocated_irqs, from, cnt);
 688         mutex_unlock(&sparse_irq_lock);
 689 }
 690 EXPORT_SYMBOL_GPL(irq_free_descs);
 691
 692 /**
 693  * irq_alloc_descs - allocate and initialize a range of irq descriptors
 694  * @irq:        Allocate for specific irq number if irq >= 0
 695  * @from:       Start the search from this irq number
 696  * @cnt:        Number of consecutive irqs to allocate.
 697  * @node:       Preferred node on which the irq descriptor should be allocated
 698  * @owner:      Owning module (can be NULL)
 699  * @affinity:   Optional pointer to an affinity mask array of size @cnt which
 700  *              hints where the irq descriptors should be allocated and which
 701  *              default affinities to use
 702  *
 703  * Returns the first irq number or error code
 704  */
 705 int __ref
 706 __irq_alloc_descs(int irq, unsigned int from, unsigned int cnt, int node,
 707                   struct module *owner, const struct cpumask *affinity)
 708 {
 709         int start, ret;
 710
 711         if (!cnt)
 712                 return -EINVAL;
 713
 714         if (irq >= 0) {
 715                 if (from > irq)
 716                         return -EINVAL;
 717                 from = irq;
 718         } else {
 719                 /*
 720                  * For interrupts which are freely allocated the
 721                  * architecture can force a lower bound to the @from
 722                  * argument. x86 uses this to exclude the GSI space.
 723                  */
 724                 from = arch_dynirq_lower_bound(from);
 725         }
 726
 727         mutex_lock(&sparse_irq_lock);
 728
 729         start = bitmap_find_next_zero_area(allocated_irqs, IRQ_BITMAP_BITS,
 730                                            from, cnt, 0);
 731         ret = -EEXIST;
 732         if (irq >=0 && start != irq)
 733                 goto unlock;
 734
 735         if (start + cnt > nr_irqs) {
 736                 ret = irq_expand_nr_irqs(start + cnt);
 737                 if (ret)
 738                         goto unlock;
 739         }
 740         ret = alloc_descs(start, cnt, node, affinity, owner);
 741 unlock:
 742         mutex_unlock(&sparse_irq_lock);
 743         return ret;
 744 }
 745 EXPORT_SYMBOL_GPL(__irq_alloc_descs);
 746
 747 #ifdef CONFIG_GENERIC_IRQ_LEGACY_ALLOC_HWIRQ
 748 /**
 749  * irq_alloc_hwirqs - Allocate an irq descriptor and initialize the hardware
 750  * @cnt:        number of interrupts to allocate
 751  * @node:       node on which to allocate
 752  *
 753  * Returns an interrupt number > 0 or 0, if the allocation fails.
 754  */
 755 unsigned int irq_alloc_hwirqs(int cnt, int node)
 756 {
 757         int i, irq = __irq_alloc_descs(-1, 0, cnt, node, NULL, NULL);
 758
 759         if (irq < 0)
 760                 return 0;
 761
 762         for (i = irq; cnt > 0; i++, cnt--) {
 763                 if (arch_setup_hwirq(i, node))
 764                         goto err;
 765                 irq_clear_status_flags(i, _IRQ_NOREQUEST);
 766         }
 767         return irq;
 768
 769 err:
 770         for (i--; i >= irq; i--) {
 771                 irq_set_status_flags(i, _IRQ_NOREQUEST | _IRQ_NOPROBE);
 772                 arch_teardown_hwirq(i);
 773         }
 774         irq_free_descs(irq, cnt);
 775         return 0;
 776 }
 777 EXPORT_SYMBOL_GPL(irq_alloc_hwirqs);
 778
 779 /**
 780  * irq_free_hwirqs - Free irq descriptor and cleanup the hardware
 781  * @from:       Free from irq number
 782  * @cnt:        number of interrupts to free
 783  *
 784  */
 785 void irq_free_hwirqs(unsigned int from, int cnt)
 786 {
 787         int i, j;
 788
 789         for (i = from, j = cnt; j > 0; i++, j--) {
 790                 irq_set_status_flags(i, _IRQ_NOREQUEST | _IRQ_NOPROBE);
 791                 arch_teardown_hwirq(i);
 792         }
 793         irq_free_descs(from, cnt);
 794 }
 795 EXPORT_SYMBOL_GPL(irq_free_hwirqs);
 796 #endif
 797
 798 /**
 799  * irq_get_next_irq - get next allocated irq number
 800  * @offset:     where to start the search
 801  *
 802  * Returns next irq number after offset or nr_irqs if none is found.
 803  */
 804 unsigned int irq_get_next_irq(unsigned int offset)
 805 {
 806         return find_next_bit(allocated_irqs, nr_irqs, offset);
 807 }
 808
 809 struct irq_desc *
 810 __irq_get_desc_lock(unsigned int irq, unsigned long *flags, bool bus,
 811                     unsigned int check)
 812 {
 813         struct irq_desc *desc = irq_to_desc(irq);
 814
 815         if (desc) {
 816                 if (check & _IRQ_DESC_CHECK) {
 817                         if ((check & _IRQ_DESC_PERCPU) &&
 818                             !irq_settings_is_per_cpu_devid(desc))
 819                                 return NULL;
 820
 821                         if (!(check & _IRQ_DESC_PERCPU) &&
 822                             irq_settings_is_per_cpu_devid(desc))
 823                                 return NULL;
 824                 }
 825
 826                 if (bus)
 827                         chip_bus_lock(desc);
 828                 raw_spin_lock_irqsave(&desc->lock, *flags);
 829         }
 830         return desc;
 831 }
 832
 833 void __irq_put_desc_unlock(struct irq_desc *desc, unsigned long flags, bool bus)
 834 {
 835         raw_spin_unlock_irqrestore(&desc->lock, flags);
 836         if (bus)
 837                 chip_bus_sync_unlock(desc);
 838 }
 839
 840 int irq_set_percpu_devid_partition(unsigned int irq,
 841                                    const struct cpumask *affinity)
 842 {
 843         struct irq_desc *desc = irq_to_desc(irq);
 844
 845         if (!desc)
 846                 return -EINVAL;
 847
 848         if (desc->percpu_enabled)
 849                 return -EINVAL;
 850
 851         desc->percpu_enabled = kzalloc(sizeof(*desc->percpu_enabled), GFP_KERNEL);
 852
 853         if (!desc->percpu_enabled)
 854                 return -ENOMEM;
 855
 856         if (affinity)
 857                 desc->percpu_affinity = affinity;
 858         else
 859                 desc->percpu_affinity = cpu_possible_mask;
 860
 861         irq_set_percpu_devid_flags(irq);
 862         return 0;
 863 }
 864
 865 int irq_set_percpu_devid(unsigned int irq)
 866 {
 867         return irq_set_percpu_devid_partition(irq, NULL);
 868 }
 869
 870 int irq_get_percpu_devid_partition(unsigned int irq, struct cpumask *affinity)
 871 {
 872         struct irq_desc *desc = irq_to_desc(irq);
 873
 874         if (!desc || !desc->percpu_enabled)
 875                 return -EINVAL;
 876
 877         if (affinity)
 878                 cpumask_copy(affinity, desc->percpu_affinity);
 879
 880         return 0;
 881 }
 882 EXPORT_SYMBOL_GPL(irq_get_percpu_devid_partition);
 883
 884 void kstat_incr_irq_this_cpu(unsigned int irq)
 885 {
 886         kstat_incr_irqs_this_cpu(irq_to_desc(irq));
 887 }
 888
 889 /**
 890  * kstat_irqs_cpu - Get the statistics for an interrupt on a cpu
 891  * @irq:        The interrupt number
 892  * @cpu:        The cpu number
 893  *
 894  * Returns the sum of interrupt counts on @cpu since boot for
 895  * @irq. The caller must ensure that the interrupt is not removed
 896  * concurrently.
 897  */
 898 unsigned int kstat_irqs_cpu(unsigned int irq, int cpu)
 899 {
 900         struct irq_desc *desc = irq_to_desc(irq);
 901
 902         return desc && desc->kstat_irqs ?
 903                         *per_cpu_ptr(desc->kstat_irqs, cpu) : 0;
 904 }
 905
 906 /**
 907  * kstat_irqs - Get the statistics for an interrupt
 908  * @irq:        The interrupt number
 909  *
 910  * Returns the sum of interrupt counts on all cpus since boot for
 911  * @irq. The caller must ensure that the interrupt is not removed
 912  * concurrently.
 913  */
 914 unsigned int kstat_irqs(unsigned int irq)
 915 {
 916         struct irq_desc *desc = irq_to_desc(irq);
 917         int cpu;
 918         unsigned int sum = 0;
 919
 920         if (!desc || !desc->kstat_irqs)
 921                 return 0;
 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 }