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->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 wakeup_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         ret = sprintf(buf, "%s\n",
 222                       irqd_is_wakeup_set(&desc->irq_data) ? "enabled" : "disabled");
 223         raw_spin_unlock_irq(&desc->lock);
 224
 225         return ret;
 226
 227 }
 228 IRQ_ATTR_RO(wakeup);
 229
 230 static ssize_t name_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         ssize_t ret = 0;
 235
 236         raw_spin_lock_irq(&desc->lock);
 237         if (desc->name)
 238                 ret = scnprintf(buf, PAGE_SIZE, "%s\n", desc->name);
 239         raw_spin_unlock_irq(&desc->lock);
 240
 241         return ret;
 242 }
 243 IRQ_ATTR_RO(name);
 244
 245 static ssize_t actions_show(struct kobject *kobj,
 246                             struct kobj_attribute *attr, char *buf)
 247 {
 248         struct irq_desc *desc = container_of(kobj, struct irq_desc, kobj);
 249         struct irqaction *action;
 250         ssize_t ret = 0;
 251         char *p = "";
 252
 253         raw_spin_lock_irq(&desc->lock);
 254         for (action = desc->action; action != NULL; action = action->next) {
 255                 ret += scnprintf(buf + ret, PAGE_SIZE - ret, "%s%s",
 256                                  p, action->name);
 257                 p = ",";
 258         }
 259         raw_spin_unlock_irq(&desc->lock);
 260
 261         if (ret)
 262                 ret += scnprintf(buf + ret, PAGE_SIZE - ret, "\n");
 263
 264         return ret;
 265 }
 266 IRQ_ATTR_RO(actions);
 267
 268 static struct attribute *irq_attrs[] = {
 269         &per_cpu_count_attr.attr,
 270         &chip_name_attr.attr,
 271         &hwirq_attr.attr,
 272         &type_attr.attr,
 273         &wakeup_attr.attr,
 274         &name_attr.attr,
 275         &actions_attr.attr,
 276         NULL
 277 };
 278 ATTRIBUTE_GROUPS(irq);
 279
 280 static struct kobj_type irq_kobj_type = {
 281         .release        = irq_kobj_release,
 282         .sysfs_ops      = &kobj_sysfs_ops,
 283         .default_groups = irq_groups,
 284 };
 285
 286 static void irq_sysfs_add(int irq, struct irq_desc *desc)
 287 {
 288         if (irq_kobj_base) {
 289                 /*
 290                  * Continue even in case of failure as this is nothing
 291                  * crucial and failures in the late irq_sysfs_init()
 292                  * cannot be rolled back.
 293                  */
 294                 if (kobject_add(&desc->kobj, irq_kobj_base, "%d", irq))
 295                         pr_warn("Failed to add kobject for irq %d\n", irq);
 296                 else
 297                         desc->istate |= IRQS_SYSFS;
 298         }
 299 }
 300
 301 static void irq_sysfs_del(struct irq_desc *desc)
 302 {
 303         /*
 304          * Only invoke kobject_del() when kobject_add() was successfully
 305          * invoked for the descriptor. This covers both early boot, where
 306          * sysfs is not initialized yet, and the case of a failed
 307          * kobject_add() invocation.
 308          */
 309         if (desc->istate & IRQS_SYSFS)
 310                 kobject_del(&desc->kobj);
 311 }
 312
 313 static int __init irq_sysfs_init(void)
 314 {
 315         struct irq_desc *desc;
 316         int irq;
 317
 318         /* Prevent concurrent irq alloc/free */
 319         irq_lock_sparse();
 320
 321         irq_kobj_base = kobject_create_and_add("irq", kernel_kobj);
 322         if (!irq_kobj_base) {
 323                 irq_unlock_sparse();
 324                 return -ENOMEM;
 325         }
 326
 327         /* Add the already allocated interrupts */
 328         for_each_irq_desc(irq, desc)
 329                 irq_sysfs_add(irq, desc);
 330         irq_unlock_sparse();
 331
 332         return 0;
 333 }
 334 postcore_initcall(irq_sysfs_init);
 335
 336 #else /* !CONFIG_SYSFS */
 337
 338 static struct kobj_type irq_kobj_type = {
 339         .release        = irq_kobj_release,
 340 };
 341
 342 static void irq_sysfs_add(int irq, struct irq_desc *desc) {}
 343 static void irq_sysfs_del(struct irq_desc *desc) {}
 344
 345 #endif /* CONFIG_SYSFS */
 346
 347 static RADIX_TREE(irq_desc_tree, GFP_KERNEL);
 348
 349 static void irq_insert_desc(unsigned int irq, struct irq_desc *desc)
 350 {
 351         radix_tree_insert(&irq_desc_tree, irq, desc);
 352 }
 353
 354 struct irq_desc *irq_to_desc(unsigned int irq)
 355 {
 356         return radix_tree_lookup(&irq_desc_tree, irq);
 357 }
 358 EXPORT_SYMBOL(irq_to_desc);
 359
 360 static void delete_irq_desc(unsigned int irq)
 361 {
 362         radix_tree_delete(&irq_desc_tree, irq);
 363 }
 364
 365 #ifdef CONFIG_SMP
 366 static void free_masks(struct irq_desc *desc)
 367 {
 368 #ifdef CONFIG_GENERIC_PENDING_IRQ
 369         free_cpumask_var(desc->pending_mask);
 370 #endif
 371         free_cpumask_var(desc->irq_common_data.affinity);
 372 #ifdef CONFIG_GENERIC_IRQ_EFFECTIVE_AFF_MASK
 373         free_cpumask_var(desc->irq_common_data.effective_affinity);
 374 #endif
 375 }
 376 #else
 377 static inline void free_masks(struct irq_desc *desc) { }
 378 #endif
 379
 380 void irq_lock_sparse(void)
 381 {
 382         mutex_lock(&sparse_irq_lock);
 383 }
 384
 385 void irq_unlock_sparse(void)
 386 {
 387         mutex_unlock(&sparse_irq_lock);
 388 }
 389
 390 static struct irq_desc *alloc_desc(int irq, int node, unsigned int flags,
 391                                    const struct cpumask *affinity,
 392                                    struct module *owner)
 393 {
 394         struct irq_desc *desc;
 395
 396         desc = kzalloc_node(sizeof(*desc), GFP_KERNEL, node);
 397         if (!desc)
 398                 return NULL;
 399         /* allocate based on nr_cpu_ids */
 400         desc->kstat_irqs = alloc_percpu(unsigned int);
 401         if (!desc->kstat_irqs)
 402                 goto err_desc;
 403
 404         if (alloc_masks(desc, node))
 405                 goto err_kstat;
 406
 407         raw_spin_lock_init(&desc->lock);
 408         lockdep_set_class(&desc->lock, &irq_desc_lock_class);
 409         mutex_init(&desc->request_mutex);
 410         init_rcu_head(&desc->rcu);
 411         init_waitqueue_head(&desc->wait_for_threads);
 412
 413         desc_set_defaults(irq, desc, node, affinity, owner);
 414         irqd_set(&desc->irq_data, flags);
 415         kobject_init(&desc->kobj, &irq_kobj_type);
 416
 417         return desc;
 418
 419 err_kstat:
 420         free_percpu(desc->kstat_irqs);
 421 err_desc:
 422         kfree(desc);
 423         return NULL;
 424 }
 425
 426 static void irq_kobj_release(struct kobject *kobj)
 427 {
 428         struct irq_desc *desc = container_of(kobj, struct irq_desc, kobj);
 429
 430         free_masks(desc);
 431         free_percpu(desc->kstat_irqs);
 432         kfree(desc);
 433 }
 434
 435 static void delayed_free_desc(struct rcu_head *rhp)
 436 {
 437         struct irq_desc *desc = container_of(rhp, struct irq_desc, rcu);
 438
 439         kobject_put(&desc->kobj);
 440 }
 441
 442 static void free_desc(unsigned int irq)
 443 {
 444         struct irq_desc *desc = irq_to_desc(irq);
 445
 446         irq_remove_debugfs_entry(desc);
 447         unregister_irq_proc(irq, desc);
 448
 449         /*
 450          * sparse_irq_lock protects also show_interrupts() and
 451          * kstat_irq_usr(). Once we deleted the descriptor from the
 452          * sparse tree we can free it. Access in proc will fail to
 453          * lookup the descriptor.
 454          *
 455          * The sysfs entry must be serialized against a concurrent
 456          * irq_sysfs_init() as well.
 457          */
 458         irq_sysfs_del(desc);
 459         delete_irq_desc(irq);
 460
 461         /*
 462          * We free the descriptor, masks and stat fields via RCU. That
 463          * allows demultiplex interrupts to do rcu based management of
 464          * the child interrupts.
 465          * This also allows us to use rcu in kstat_irqs_usr().
 466          */
 467         call_rcu(&desc->rcu, delayed_free_desc);
 468 }
 469
 470 static int alloc_descs(unsigned int start, unsigned int cnt, int node,
 471                        const struct irq_affinity_desc *affinity,
 472                        struct module *owner)
 473 {
 474         struct irq_desc *desc;
 475         int i;
 476
 477         /* Validate affinity mask(s) */
 478         if (affinity) {
 479                 for (i = 0; i < cnt; i++) {
 480                         if (cpumask_empty(&affinity[i].mask))
 481                                 return -EINVAL;
 482                 }
 483         }
 484
 485         for (i = 0; i < cnt; i++) {
 486                 const struct cpumask *mask = NULL;
 487                 unsigned int flags = 0;
 488
 489                 if (affinity) {
 490                         if (affinity->is_managed) {
 491                                 flags = IRQD_AFFINITY_MANAGED |
 492                                         IRQD_MANAGED_SHUTDOWN;
 493                         }
 494                         mask = &affinity->mask;
 495                         node = cpu_to_node(cpumask_first(mask));
 496                         affinity++;
 497                 }
 498
 499                 desc = alloc_desc(start + i, node, flags, mask, owner);
 500                 if (!desc)
 501                         goto err;
 502                 irq_insert_desc(start + i, desc);
 503                 irq_sysfs_add(start + i, desc);
 504                 irq_add_debugfs_entry(start + i, desc);
 505         }
 506         bitmap_set(allocated_irqs, start, cnt);
 507         return start;
 508
 509 err:
 510         for (i--; i >= 0; i--)
 511                 free_desc(start + i);
 512         return -ENOMEM;
 513 }
 514
 515 static int irq_expand_nr_irqs(unsigned int nr)
 516 {
 517         if (nr > IRQ_BITMAP_BITS)
 518                 return -ENOMEM;
 519         nr_irqs = nr;
 520         return 0;
 521 }
 522
 523 int __init early_irq_init(void)
 524 {
 525         int i, initcnt, node = first_online_node;
 526         struct irq_desc *desc;
 527
 528         init_irq_default_affinity();
 529
 530         /* Let arch update nr_irqs and return the nr of preallocated irqs */
 531         initcnt = arch_probe_nr_irqs();
 532         printk(KERN_INFO "NR_IRQS: %d, nr_irqs: %d, preallocated irqs: %d\n",
 533                NR_IRQS, nr_irqs, initcnt);
 534
 535         if (WARN_ON(nr_irqs > IRQ_BITMAP_BITS))
 536                 nr_irqs = IRQ_BITMAP_BITS;
 537
 538         if (WARN_ON(initcnt > IRQ_BITMAP_BITS))
 539                 initcnt = IRQ_BITMAP_BITS;
 540
 541         if (initcnt > nr_irqs)
 542                 nr_irqs = initcnt;
 543
 544         for (i = 0; i < initcnt; i++) {
 545                 desc = alloc_desc(i, node, 0, NULL, NULL);
 546                 set_bit(i, allocated_irqs);
 547                 irq_insert_desc(i, desc);
 548         }
 549         return arch_early_irq_init();
 550 }
 551
 552 #else /* !CONFIG_SPARSE_IRQ */
 553
 554 struct irq_desc irq_desc[NR_IRQS] __cacheline_aligned_in_smp = {
 555         [0 ... NR_IRQS-1] = {
 556                 .handle_irq     = handle_bad_irq,
 557                 .depth          = 1,
 558                 .lock           = __RAW_SPIN_LOCK_UNLOCKED(irq_desc->lock),
 559         }
 560 };
 561
 562 int __init early_irq_init(void)
 563 {
 564         int count, i, node = first_online_node;
 565         struct irq_desc *desc;
 566
 567         init_irq_default_affinity();
 568
 569         printk(KERN_INFO "NR_IRQS: %d\n", NR_IRQS);
 570
 571         desc = irq_desc;
 572         count = ARRAY_SIZE(irq_desc);
 573
 574         for (i = 0; i < count; i++) {
 575                 desc[i].kstat_irqs = alloc_percpu(unsigned int);
 576                 alloc_masks(&desc[i], node);
 577                 raw_spin_lock_init(&desc[i].lock);
 578                 lockdep_set_class(&desc[i].lock, &irq_desc_lock_class);
 579                 mutex_init(&desc[i].request_mutex);
 580                 init_waitqueue_head(&desc[i].wait_for_threads);
 581                 desc_set_defaults(i, &desc[i], node, NULL, NULL);
 582         }
 583         return arch_early_irq_init();
 584 }
 585
 586 struct irq_desc *irq_to_desc(unsigned int irq)
 587 {
 588         return (irq < NR_IRQS) ? irq_desc + irq : NULL;
 589 }
 590 EXPORT_SYMBOL(irq_to_desc);
 591
 592 static void free_desc(unsigned int irq)
 593 {
 594         struct irq_desc *desc = irq_to_desc(irq);
 595         unsigned long flags;
 596
 597         raw_spin_lock_irqsave(&desc->lock, flags);
 598         desc_set_defaults(irq, desc, irq_desc_get_node(desc), NULL, NULL);
 599         raw_spin_unlock_irqrestore(&desc->lock, flags);
 600 }
 601
 602 static inline int alloc_descs(unsigned int start, unsigned int cnt, int node,
 603                               const struct irq_affinity_desc *affinity,
 604                               struct module *owner)
 605 {
 606         u32 i;
 607
 608         for (i = 0; i < cnt; i++) {
 609                 struct irq_desc *desc = irq_to_desc(start + i);
 610
 611                 desc->owner = owner;
 612         }
 613         bitmap_set(allocated_irqs, start, cnt);
 614         return start;
 615 }
 616
 617 static int irq_expand_nr_irqs(unsigned int nr)
 618 {
 619         return -ENOMEM;
 620 }
 621
 622 void irq_mark_irq(unsigned int irq)
 623 {
 624         mutex_lock(&sparse_irq_lock);
 625         bitmap_set(allocated_irqs, irq, 1);
 626         mutex_unlock(&sparse_irq_lock);
 627 }
 628
 629 #ifdef CONFIG_GENERIC_IRQ_LEGACY
 630 void irq_init_desc(unsigned int irq)
 631 {
 632         free_desc(irq);
 633 }
 634 #endif
 635
 636 #endif /* !CONFIG_SPARSE_IRQ */
 637
 638 /**
 639  * generic_handle_irq - Invoke the handler for a particular irq
 640  * @irq:        The irq number to handle
 641  *
 642  */
 643 int generic_handle_irq(unsigned int irq)
 644 {
 645         struct irq_desc *desc = irq_to_desc(irq);
 646
 647         if (!desc)
 648                 return -EINVAL;
 649         generic_handle_irq_desc(desc);
 650         return 0;
 651 }
 652 EXPORT_SYMBOL_GPL(generic_handle_irq);
 653
 654 #ifdef CONFIG_HANDLE_DOMAIN_IRQ
 655 /**
 656  * __handle_domain_irq - Invoke the handler for a HW irq belonging to a domain
 657  * @domain:     The domain where to perform the lookup
 658  * @hwirq:      The HW irq number to convert to a logical one
 659  * @lookup:     Whether to perform the domain lookup or not
 660  * @regs:       Register file coming from the low-level handling code
 661  *
 662  * Returns:     0 on success, or -EINVAL if conversion has failed
 663  */
 664 int __handle_domain_irq(struct irq_domain *domain, unsigned int hwirq,
 665                         bool lookup, struct pt_regs *regs)
 666 {
 667         struct pt_regs *old_regs = set_irq_regs(regs);
 668         unsigned int irq = hwirq;
 669         int ret = 0;
 670
 671         irq_enter();
 672
 673 #ifdef CONFIG_IRQ_DOMAIN
 674         if (lookup)
 675                 irq = irq_find_mapping(domain, hwirq);
 676 #endif
 677
 678         /*
 679          * Some hardware gives randomly wrong interrupts.  Rather
 680          * than crashing, do something sensible.
 681          */
 682         if (unlikely(!irq || irq >= nr_irqs)) {
 683                 ack_bad_irq(irq);
 684                 ret = -EINVAL;
 685         } else {
 686                 generic_handle_irq(irq);
 687         }
 688
 689         irq_exit();
 690         set_irq_regs(old_regs);
 691         return ret;
 692 }
 693
 694 #ifdef CONFIG_IRQ_DOMAIN
 695 /**
 696  * handle_domain_nmi - Invoke the handler for a HW irq belonging to a domain
 697  * @domain:     The domain where to perform the lookup
 698  * @hwirq:      The HW irq number to convert to a logical one
 699  * @regs:       Register file coming from the low-level handling code
 700  *
 701  *              This function must be called from an NMI context.
 702  *
 703  * Returns:     0 on success, or -EINVAL if conversion has failed
 704  */
 705 int handle_domain_nmi(struct irq_domain *domain, unsigned int hwirq,
 706                       struct pt_regs *regs)
 707 {
 708         struct pt_regs *old_regs = set_irq_regs(regs);
 709         unsigned int irq;
 710         int ret = 0;
 711
 712         /*
 713          * NMI context needs to be setup earlier in order to deal with tracing.
 714          */
 715         WARN_ON(!in_nmi());
 716
 717         irq = irq_find_mapping(domain, hwirq);
 718
 719         /*
 720          * ack_bad_irq is not NMI-safe, just report
 721          * an invalid interrupt.
 722          */
 723         if (likely(irq))
 724                 generic_handle_irq(irq);
 725         else
 726                 ret = -EINVAL;
 727
 728         set_irq_regs(old_regs);
 729         return ret;
 730 }
 731 #endif
 732 #endif
 733
 734 /* Dynamic interrupt handling */
 735
 736 /**
 737  * irq_free_descs - free irq descriptors
 738  * @from:       Start of descriptor range
 739  * @cnt:        Number of consecutive irqs to free
 740  */
 741 void irq_free_descs(unsigned int from, unsigned int cnt)
 742 {
 743         int i;
 744
 745         if (from >= nr_irqs || (from + cnt) > nr_irqs)
 746                 return;
 747
 748         mutex_lock(&sparse_irq_lock);
 749         for (i = 0; i < cnt; i++)
 750                 free_desc(from + i);
 751
 752         bitmap_clear(allocated_irqs, from, cnt);
 753         mutex_unlock(&sparse_irq_lock);
 754 }
 755 EXPORT_SYMBOL_GPL(irq_free_descs);
 756
 757 /**
 758  * irq_alloc_descs - allocate and initialize a range of irq descriptors
 759  * @irq:        Allocate for specific irq number if irq >= 0
 760  * @from:       Start the search from this irq number
 761  * @cnt:        Number of consecutive irqs to allocate.
 762  * @node:       Preferred node on which the irq descriptor should be allocated
 763  * @owner:      Owning module (can be NULL)
 764  * @affinity:   Optional pointer to an affinity mask array of size @cnt which
 765  *              hints where the irq descriptors should be allocated and which
 766  *              default affinities to use
 767  *
 768  * Returns the first irq number or error code
 769  */
 770 int __ref
 771 __irq_alloc_descs(int irq, unsigned int from, unsigned int cnt, int node,
 772                   struct module *owner, const struct irq_affinity_desc *affinity)
 773 {
 774         int start, ret;
 775
 776         if (!cnt)
 777                 return -EINVAL;
 778
 779         if (irq >= 0) {
 780                 if (from > irq)
 781                         return -EINVAL;
 782                 from = irq;
 783         } else {
 784                 /*
 785                  * For interrupts which are freely allocated the
 786                  * architecture can force a lower bound to the @from
 787                  * argument. x86 uses this to exclude the GSI space.
 788                  */
 789                 from = arch_dynirq_lower_bound(from);
 790         }
 791
 792         mutex_lock(&sparse_irq_lock);
 793
 794         start = bitmap_find_next_zero_area(allocated_irqs, IRQ_BITMAP_BITS,
 795                                            from, cnt, 0);
 796         ret = -EEXIST;
 797         if (irq >=0 && start != irq)
 798                 goto unlock;
 799
 800         if (start + cnt > nr_irqs) {
 801                 ret = irq_expand_nr_irqs(start + cnt);
 802                 if (ret)
 803                         goto unlock;
 804         }
 805         ret = alloc_descs(start, cnt, node, affinity, owner);
 806 unlock:
 807         mutex_unlock(&sparse_irq_lock);
 808         return ret;
 809 }
 810 EXPORT_SYMBOL_GPL(__irq_alloc_descs);
 811
 812 #ifdef CONFIG_GENERIC_IRQ_LEGACY_ALLOC_HWIRQ
 813 /**
 814  * irq_alloc_hwirqs - Allocate an irq descriptor and initialize the hardware
 815  * @cnt:        number of interrupts to allocate
 816  * @node:       node on which to allocate
 817  *
 818  * Returns an interrupt number > 0 or 0, if the allocation fails.
 819  */
 820 unsigned int irq_alloc_hwirqs(int cnt, int node)
 821 {
 822         int i, irq = __irq_alloc_descs(-1, 0, cnt, node, NULL, NULL);
 823
 824         if (irq < 0)
 825                 return 0;
 826
 827         for (i = irq; cnt > 0; i++, cnt--) {
 828                 if (arch_setup_hwirq(i, node))
 829                         goto err;
 830                 irq_clear_status_flags(i, _IRQ_NOREQUEST);
 831         }
 832         return irq;
 833
 834 err:
 835         for (i--; i >= irq; i--) {
 836                 irq_set_status_flags(i, _IRQ_NOREQUEST | _IRQ_NOPROBE);
 837                 arch_teardown_hwirq(i);
 838         }
 839         irq_free_descs(irq, cnt);
 840         return 0;
 841 }
 842 EXPORT_SYMBOL_GPL(irq_alloc_hwirqs);
 843
 844 /**
 845  * irq_free_hwirqs - Free irq descriptor and cleanup the hardware
 846  * @from:       Free from irq number
 847  * @cnt:        number of interrupts to free
 848  *
 849  */
 850 void irq_free_hwirqs(unsigned int from, int cnt)
 851 {
 852         int i, j;
 853
 854         for (i = from, j = cnt; j > 0; i++, j--) {
 855                 irq_set_status_flags(i, _IRQ_NOREQUEST | _IRQ_NOPROBE);
 856                 arch_teardown_hwirq(i);
 857         }
 858         irq_free_descs(from, cnt);
 859 }
 860 EXPORT_SYMBOL_GPL(irq_free_hwirqs);
 861 #endif
 862
 863 /**
 864  * irq_get_next_irq - get next allocated irq number
 865  * @offset:     where to start the search
 866  *
 867  * Returns next irq number after offset or nr_irqs if none is found.
 868  */
 869 unsigned int irq_get_next_irq(unsigned int offset)
 870 {
 871         return find_next_bit(allocated_irqs, nr_irqs, offset);
 872 }
 873
 874 struct irq_desc *
 875 __irq_get_desc_lock(unsigned int irq, unsigned long *flags, bool bus,
 876                     unsigned int check)
 877 {
 878         struct irq_desc *desc = irq_to_desc(irq);
 879
 880         if (desc) {
 881                 if (check & _IRQ_DESC_CHECK) {
 882                         if ((check & _IRQ_DESC_PERCPU) &&
 883                             !irq_settings_is_per_cpu_devid(desc))
 884                                 return NULL;
 885
 886                         if (!(check & _IRQ_DESC_PERCPU) &&
 887                             irq_settings_is_per_cpu_devid(desc))
 888                                 return NULL;
 889                 }
 890
 891                 if (bus)
 892                         chip_bus_lock(desc);
 893                 raw_spin_lock_irqsave(&desc->lock, *flags);
 894         }
 895         return desc;
 896 }
 897
 898 void __irq_put_desc_unlock(struct irq_desc *desc, unsigned long flags, bool bus)
 899 {
 900         raw_spin_unlock_irqrestore(&desc->lock, flags);
 901         if (bus)
 902                 chip_bus_sync_unlock(desc);
 903 }
 904
 905 int irq_set_percpu_devid_partition(unsigned int irq,
 906                                    const struct cpumask *affinity)
 907 {
 908         struct irq_desc *desc = irq_to_desc(irq);
 909
 910         if (!desc)
 911                 return -EINVAL;
 912
 913         if (desc->percpu_enabled)
 914                 return -EINVAL;
 915
 916         desc->percpu_enabled = kzalloc(sizeof(*desc->percpu_enabled), GFP_KERNEL);
 917
 918         if (!desc->percpu_enabled)
 919                 return -ENOMEM;
 920
 921         if (affinity)
 922                 desc->percpu_affinity = affinity;
 923         else
 924                 desc->percpu_affinity = cpu_possible_mask;
 925
 926         irq_set_percpu_devid_flags(irq);
 927         return 0;
 928 }
 929
 930 int irq_set_percpu_devid(unsigned int irq)
 931 {
 932         return irq_set_percpu_devid_partition(irq, NULL);
 933 }
 934
 935 int irq_get_percpu_devid_partition(unsigned int irq, struct cpumask *affinity)
 936 {
 937         struct irq_desc *desc = irq_to_desc(irq);
 938
 939         if (!desc || !desc->percpu_enabled)
 940                 return -EINVAL;
 941
 942         if (affinity)
 943                 cpumask_copy(affinity, desc->percpu_affinity);
 944
 945         return 0;
 946 }
 947 EXPORT_SYMBOL_GPL(irq_get_percpu_devid_partition);
 948
 949 void kstat_incr_irq_this_cpu(unsigned int irq)
 950 {
 951         kstat_incr_irqs_this_cpu(irq_to_desc(irq));
 952 }
 953
 954 /**
 955  * kstat_irqs_cpu - Get the statistics for an interrupt on a cpu
 956  * @irq:        The interrupt number
 957  * @cpu:        The cpu number
 958  *
 959  * Returns the sum of interrupt counts on @cpu since boot for
 960  * @irq. The caller must ensure that the interrupt is not removed
 961  * concurrently.
 962  */
 963 unsigned int kstat_irqs_cpu(unsigned int irq, int cpu)
 964 {
 965         struct irq_desc *desc = irq_to_desc(irq);
 966
 967         return desc && desc->kstat_irqs ?
 968                         *per_cpu_ptr(desc->kstat_irqs, cpu) : 0;
 969 }
 970
 971 static bool irq_is_nmi(struct irq_desc *desc)
 972 {
 973         return desc->istate & IRQS_NMI;
 974 }
 975
 976 /**
 977  * kstat_irqs - Get the statistics for an interrupt
 978  * @irq:        The interrupt number
 979  *
 980  * Returns the sum of interrupt counts on all cpus since boot for
 981  * @irq. The caller must ensure that the interrupt is not removed
 982  * concurrently.
 983  */
 984 unsigned int kstat_irqs(unsigned int irq)
 985 {
 986         struct irq_desc *desc = irq_to_desc(irq);
 987         unsigned int sum = 0;
 988         int cpu;
 989
 990         if (!desc || !desc->kstat_irqs)
 991                 return 0;
 992         if (!irq_settings_is_per_cpu_devid(desc) &&
 993             !irq_settings_is_per_cpu(desc) &&
 994             !irq_is_nmi(desc))
 995             return desc->tot_count;
 996
 997         for_each_possible_cpu(cpu)
 998                 sum += *per_cpu_ptr(desc->kstat_irqs, cpu);
 999         return sum;
1000 }
1001
1002 /**
1003  * kstat_irqs_usr - Get the statistics for an interrupt
1004  * @irq:        The interrupt number
1005  *
1006  * Returns the sum of interrupt counts on all cpus since boot for @irq.
1007  * Contrary to kstat_irqs() this can be called from any context.
1008  * It uses rcu since a concurrent removal of an interrupt descriptor is
1009  * observing an rcu grace period before delayed_free_desc()/irq_kobj_release().
1010  */
1011 unsigned int kstat_irqs_usr(unsigned int irq)
1012 {
1013         unsigned int sum;
1014
1015         rcu_read_lock();
1016         sum = kstat_irqs(irq);
1017         rcu_read_unlock();
1018         return sum;
1019 }