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         ssize_t ret = 0;
 151         char *p = "";
 152         int cpu;
 153
 154         for_each_possible_cpu(cpu) {
 155                 unsigned int c = irq_desc_kstat_cpu(desc, 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.
 292                  */
 293                 if (kobject_add(&desc->kobj, irq_kobj_base, "%d", irq))
 294                         pr_warn("Failed to add kobject for irq %d\n", irq);
 295         }
 296 }
 297
 298 static void irq_sysfs_del(struct irq_desc *desc)
 299 {
 300         /*
 301          * If irq_sysfs_init() has not yet been invoked (early boot), then
 302          * irq_kobj_base is NULL and the descriptor was never added.
 303          * kobject_del() complains about a object with no parent, so make
 304          * it conditional.
 305          */
 306         if (irq_kobj_base)
 307                 kobject_del(&desc->kobj);
 308 }
 309
 310 static int __init irq_sysfs_init(void)
 311 {
 312         struct irq_desc *desc;
 313         int irq;
 314
 315         /* Prevent concurrent irq alloc/free */
 316         irq_lock_sparse();
 317
 318         irq_kobj_base = kobject_create_and_add("irq", kernel_kobj);
 319         if (!irq_kobj_base) {
 320                 irq_unlock_sparse();
 321                 return -ENOMEM;
 322         }
 323
 324         /* Add the already allocated interrupts */
 325         for_each_irq_desc(irq, desc)
 326                 irq_sysfs_add(irq, desc);
 327         irq_unlock_sparse();
 328
 329         return 0;
 330 }
 331 postcore_initcall(irq_sysfs_init);
 332
 333 #else /* !CONFIG_SYSFS */
 334
 335 static struct kobj_type irq_kobj_type = {
 336         .release        = irq_kobj_release,
 337 };
 338
 339 static void irq_sysfs_add(int irq, struct irq_desc *desc) {}
 340 static void irq_sysfs_del(struct irq_desc *desc) {}
 341
 342 #endif /* CONFIG_SYSFS */
 343
 344 static RADIX_TREE(irq_desc_tree, GFP_KERNEL);
 345
 346 static void irq_insert_desc(unsigned int irq, struct irq_desc *desc)
 347 {
 348         radix_tree_insert(&irq_desc_tree, irq, desc);
 349 }
 350
 351 struct irq_desc *irq_to_desc(unsigned int irq)
 352 {
 353         return radix_tree_lookup(&irq_desc_tree, irq);
 354 }
 355 #ifdef CONFIG_KVM_BOOK3S_64_HV
 356 EXPORT_SYMBOL_GPL(irq_to_desc);
 357 #endif
 358
 359 static void delete_irq_desc(unsigned int irq)
 360 {
 361         radix_tree_delete(&irq_desc_tree, irq);
 362 }
 363
 364 #ifdef CONFIG_SMP
 365 static void free_masks(struct irq_desc *desc)
 366 {
 367 #ifdef CONFIG_GENERIC_PENDING_IRQ
 368         free_cpumask_var(desc->pending_mask);
 369 #endif
 370         free_cpumask_var(desc->irq_common_data.affinity);
 371 #ifdef CONFIG_GENERIC_IRQ_EFFECTIVE_AFF_MASK
 372         free_cpumask_var(desc->irq_common_data.effective_affinity);
 373 #endif
 374 }
 375 #else
 376 static inline void free_masks(struct irq_desc *desc) { }
 377 #endif
 378
 379 void irq_lock_sparse(void)
 380 {
 381         mutex_lock(&sparse_irq_lock);
 382 }
 383
 384 void irq_unlock_sparse(void)
 385 {
 386         mutex_unlock(&sparse_irq_lock);
 387 }
 388
 389 static struct irq_desc *alloc_desc(int irq, int node, unsigned int flags,
 390                                    const struct cpumask *affinity,
 391                                    struct module *owner)
 392 {
 393         struct irq_desc *desc;
 394
 395         desc = kzalloc_node(sizeof(*desc), GFP_KERNEL, node);
 396         if (!desc)
 397                 return NULL;
 398         /* allocate based on nr_cpu_ids */
 399         desc->kstat_irqs = alloc_percpu(unsigned int);
 400         if (!desc->kstat_irqs)
 401                 goto err_desc;
 402
 403         if (alloc_masks(desc, node))
 404                 goto err_kstat;
 405
 406         raw_spin_lock_init(&desc->lock);
 407         lockdep_set_class(&desc->lock, &irq_desc_lock_class);
 408         mutex_init(&desc->request_mutex);
 409         init_rcu_head(&desc->rcu);
 410
 411         desc_set_defaults(irq, desc, node, affinity, owner);
 412         irqd_set(&desc->irq_data, flags);
 413         kobject_init(&desc->kobj, &irq_kobj_type);
 414
 415         return desc;
 416
 417 err_kstat:
 418         free_percpu(desc->kstat_irqs);
 419 err_desc:
 420         kfree(desc);
 421         return NULL;
 422 }
 423
 424 static void irq_kobj_release(struct kobject *kobj)
 425 {
 426         struct irq_desc *desc = container_of(kobj, struct irq_desc, kobj);
 427
 428         free_masks(desc);
 429         free_percpu(desc->kstat_irqs);
 430         kfree(desc);
 431 }
 432
 433 static void delayed_free_desc(struct rcu_head *rhp)
 434 {
 435         struct irq_desc *desc = container_of(rhp, struct irq_desc, rcu);
 436
 437         kobject_put(&desc->kobj);
 438 }
 439
 440 static void free_desc(unsigned int irq)
 441 {
 442         struct irq_desc *desc = irq_to_desc(irq);
 443
 444         irq_remove_debugfs_entry(desc);
 445         unregister_irq_proc(irq, desc);
 446
 447         /*
 448          * sparse_irq_lock protects also show_interrupts() and
 449          * kstat_irq_usr(). Once we deleted the descriptor from the
 450          * sparse tree we can free it. Access in proc will fail to
 451          * lookup the descriptor.
 452          *
 453          * The sysfs entry must be serialized against a concurrent
 454          * irq_sysfs_init() as well.
 455          */
 456         irq_sysfs_del(desc);
 457         delete_irq_desc(irq);
 458
 459         /*
 460          * We free the descriptor, masks and stat fields via RCU. That
 461          * allows demultiplex interrupts to do rcu based management of
 462          * the child interrupts.
 463          * This also allows us to use rcu in kstat_irqs_usr().
 464          */
 465         call_rcu(&desc->rcu, delayed_free_desc);
 466 }
 467
 468 static int alloc_descs(unsigned int start, unsigned int cnt, int node,
 469                        const struct irq_affinity_desc *affinity,
 470                        struct module *owner)
 471 {
 472         struct irq_desc *desc;
 473         int i;
 474
 475         /* Validate affinity mask(s) */
 476         if (affinity) {
 477                 for (i = 0; i < cnt; i++) {
 478                         if (cpumask_empty(&affinity[i].mask))
 479                                 return -EINVAL;
 480                 }
 481         }
 482
 483         for (i = 0; i < cnt; i++) {
 484                 const struct cpumask *mask = NULL;
 485                 unsigned int flags = 0;
 486
 487                 if (affinity) {
 488                         if (affinity->is_managed) {
 489                                 flags = IRQD_AFFINITY_MANAGED |
 490                                         IRQD_MANAGED_SHUTDOWN;
 491                         }
 492                         mask = &affinity->mask;
 493                         node = cpu_to_node(cpumask_first(mask));
 494                         affinity++;
 495                 }
 496
 497                 desc = alloc_desc(start + i, node, flags, mask, owner);
 498                 if (!desc)
 499                         goto err;
 500                 irq_insert_desc(start + i, desc);
 501                 irq_sysfs_add(start + i, desc);
 502                 irq_add_debugfs_entry(start + i, desc);
 503         }
 504         bitmap_set(allocated_irqs, start, cnt);
 505         return start;
 506
 507 err:
 508         for (i--; i >= 0; i--)
 509                 free_desc(start + i);
 510         return -ENOMEM;
 511 }
 512
 513 static int irq_expand_nr_irqs(unsigned int nr)
 514 {
 515         if (nr > IRQ_BITMAP_BITS)
 516                 return -ENOMEM;
 517         nr_irqs = nr;
 518         return 0;
 519 }
 520
 521 int __init early_irq_init(void)
 522 {
 523         int i, initcnt, node = first_online_node;
 524         struct irq_desc *desc;
 525
 526         init_irq_default_affinity();
 527
 528         /* Let arch update nr_irqs and return the nr of preallocated irqs */
 529         initcnt = arch_probe_nr_irqs();
 530         printk(KERN_INFO "NR_IRQS: %d, nr_irqs: %d, preallocated irqs: %d\n",
 531                NR_IRQS, nr_irqs, initcnt);
 532
 533         if (WARN_ON(nr_irqs > IRQ_BITMAP_BITS))
 534                 nr_irqs = IRQ_BITMAP_BITS;
 535
 536         if (WARN_ON(initcnt > IRQ_BITMAP_BITS))
 537                 initcnt = IRQ_BITMAP_BITS;
 538
 539         if (initcnt > nr_irqs)
 540                 nr_irqs = initcnt;
 541
 542         for (i = 0; i < initcnt; i++) {
 543                 desc = alloc_desc(i, node, 0, NULL, NULL);
 544                 set_bit(i, allocated_irqs);
 545                 irq_insert_desc(i, desc);
 546         }
 547         return arch_early_irq_init();
 548 }
 549
 550 #else /* !CONFIG_SPARSE_IRQ */
 551
 552 struct irq_desc irq_desc[NR_IRQS] __cacheline_aligned_in_smp = {
 553         [0 ... NR_IRQS-1] = {
 554                 .handle_irq     = handle_bad_irq,
 555                 .depth          = 1,
 556                 .lock           = __RAW_SPIN_LOCK_UNLOCKED(irq_desc->lock),
 557         }
 558 };
 559
 560 int __init early_irq_init(void)
 561 {
 562         int count, i, node = first_online_node;
 563         struct irq_desc *desc;
 564
 565         init_irq_default_affinity();
 566
 567         printk(KERN_INFO "NR_IRQS: %d\n", NR_IRQS);
 568
 569         desc = irq_desc;
 570         count = ARRAY_SIZE(irq_desc);
 571
 572         for (i = 0; i < count; i++) {
 573                 desc[i].kstat_irqs = alloc_percpu(unsigned int);
 574                 alloc_masks(&desc[i], node);
 575                 raw_spin_lock_init(&desc[i].lock);
 576                 lockdep_set_class(&desc[i].lock, &irq_desc_lock_class);
 577                 mutex_init(&desc[i].request_mutex);
 578                 desc_set_defaults(i, &desc[i], node, NULL, NULL);
 579         }
 580         return arch_early_irq_init();
 581 }
 582
 583 struct irq_desc *irq_to_desc(unsigned int irq)
 584 {
 585         return (irq < NR_IRQS) ? irq_desc + irq : NULL;
 586 }
 587 EXPORT_SYMBOL(irq_to_desc);
 588
 589 static void free_desc(unsigned int irq)
 590 {
 591         struct irq_desc *desc = irq_to_desc(irq);
 592         unsigned long flags;
 593
 594         raw_spin_lock_irqsave(&desc->lock, flags);
 595         desc_set_defaults(irq, desc, irq_desc_get_node(desc), NULL, NULL);
 596         raw_spin_unlock_irqrestore(&desc->lock, flags);
 597 }
 598
 599 static inline int alloc_descs(unsigned int start, unsigned int cnt, int node,
 600                               const struct irq_affinity_desc *affinity,
 601                               struct module *owner)
 602 {
 603         u32 i;
 604
 605         for (i = 0; i < cnt; i++) {
 606                 struct irq_desc *desc = irq_to_desc(start + i);
 607
 608                 desc->owner = owner;
 609         }
 610         bitmap_set(allocated_irqs, start, cnt);
 611         return start;
 612 }
 613
 614 static int irq_expand_nr_irqs(unsigned int nr)
 615 {
 616         return -ENOMEM;
 617 }
 618
 619 void irq_mark_irq(unsigned int irq)
 620 {
 621         mutex_lock(&sparse_irq_lock);
 622         bitmap_set(allocated_irqs, irq, 1);
 623         mutex_unlock(&sparse_irq_lock);
 624 }
 625
 626 #ifdef CONFIG_GENERIC_IRQ_LEGACY
 627 void irq_init_desc(unsigned int irq)
 628 {
 629         free_desc(irq);
 630 }
 631 #endif
 632
 633 #endif /* !CONFIG_SPARSE_IRQ */
 634
 635 /**
 636  * generic_handle_irq - Invoke the handler for a particular irq
 637  * @irq:        The irq number to handle
 638  *
 639  */
 640 int generic_handle_irq(unsigned int irq)
 641 {
 642         struct irq_desc *desc = irq_to_desc(irq);
 643         struct irq_data *data;
 644
 645         if (!desc)
 646                 return -EINVAL;
 647
 648         data = irq_desc_get_irq_data(desc);
 649         if (WARN_ON_ONCE(!in_irq() && handle_enforce_irqctx(data)))
 650                 return -EPERM;
 651
 652         generic_handle_irq_desc(desc);
 653         return 0;
 654 }
 655 EXPORT_SYMBOL_GPL(generic_handle_irq);
 656
 657 #ifdef CONFIG_HANDLE_DOMAIN_IRQ
 658 /**
 659  * __handle_domain_irq - Invoke the handler for a HW irq belonging to a domain
 660  * @domain:     The domain where to perform the lookup
 661  * @hwirq:      The HW irq number to convert to a logical one
 662  * @lookup:     Whether to perform the domain lookup or not
 663  * @regs:       Register file coming from the low-level handling code
 664  *
 665  * Returns:     0 on success, or -EINVAL if conversion has failed
 666  */
 667 int __handle_domain_irq(struct irq_domain *domain, unsigned int hwirq,
 668                         bool lookup, struct pt_regs *regs)
 669 {
 670         struct pt_regs *old_regs = set_irq_regs(regs);
 671         unsigned int irq = hwirq;
 672         int ret = 0;
 673
 674         irq_enter();
 675
 676 #ifdef CONFIG_IRQ_DOMAIN
 677         if (lookup)
 678                 irq = irq_find_mapping(domain, hwirq);
 679 #endif
 680
 681         /*
 682          * Some hardware gives randomly wrong interrupts.  Rather
 683          * than crashing, do something sensible.
 684          */
 685         if (unlikely(!irq || irq >= nr_irqs)) {
 686                 ack_bad_irq(irq);
 687                 ret = -EINVAL;
 688         } else {
 689                 generic_handle_irq(irq);
 690         }
 691
 692         irq_exit();
 693         set_irq_regs(old_regs);
 694         return ret;
 695 }
 696
 697 #ifdef CONFIG_IRQ_DOMAIN
 698 /**
 699  * handle_domain_nmi - Invoke the handler for a HW irq belonging to a domain
 700  * @domain:     The domain where to perform the lookup
 701  * @hwirq:      The HW irq number to convert to a logical one
 702  * @regs:       Register file coming from the low-level handling code
 703  *
 704  *              This function must be called from an NMI context.
 705  *
 706  * Returns:     0 on success, or -EINVAL if conversion has failed
 707  */
 708 int handle_domain_nmi(struct irq_domain *domain, unsigned int hwirq,
 709                       struct pt_regs *regs)
 710 {
 711         struct pt_regs *old_regs = set_irq_regs(regs);
 712         unsigned int irq;
 713         int ret = 0;
 714
 715         /*
 716          * NMI context needs to be setup earlier in order to deal with tracing.
 717          */
 718         WARN_ON(!in_nmi());
 719
 720         irq = irq_find_mapping(domain, hwirq);
 721
 722         /*
 723          * ack_bad_irq is not NMI-safe, just report
 724          * an invalid interrupt.
 725          */
 726         if (likely(irq))
 727                 generic_handle_irq(irq);
 728         else
 729                 ret = -EINVAL;
 730
 731         set_irq_regs(old_regs);
 732         return ret;
 733 }
 734 #endif
 735 #endif
 736
 737 /* Dynamic interrupt handling */
 738
 739 /**
 740  * irq_free_descs - free irq descriptors
 741  * @from:       Start of descriptor range
 742  * @cnt:        Number of consecutive irqs to free
 743  */
 744 void irq_free_descs(unsigned int from, unsigned int cnt)
 745 {
 746         int i;
 747
 748         if (from >= nr_irqs || (from + cnt) > nr_irqs)
 749                 return;
 750
 751         mutex_lock(&sparse_irq_lock);
 752         for (i = 0; i < cnt; i++)
 753                 free_desc(from + i);
 754
 755         bitmap_clear(allocated_irqs, from, cnt);
 756         mutex_unlock(&sparse_irq_lock);
 757 }
 758 EXPORT_SYMBOL_GPL(irq_free_descs);
 759
 760 /**
 761  * __irq_alloc_descs - allocate and initialize a range of irq descriptors
 762  * @irq:        Allocate for specific irq number if irq >= 0
 763  * @from:       Start the search from this irq number
 764  * @cnt:        Number of consecutive irqs to allocate.
 765  * @node:       Preferred node on which the irq descriptor should be allocated
 766  * @owner:      Owning module (can be NULL)
 767  * @affinity:   Optional pointer to an affinity mask array of size @cnt which
 768  *              hints where the irq descriptors should be allocated and which
 769  *              default affinities to use
 770  *
 771  * Returns the first irq number or error code
 772  */
 773 int __ref
 774 __irq_alloc_descs(int irq, unsigned int from, unsigned int cnt, int node,
 775                   struct module *owner, const struct irq_affinity_desc *affinity)
 776 {
 777         int start, ret;
 778
 779         if (!cnt)
 780                 return -EINVAL;
 781
 782         if (irq >= 0) {
 783                 if (from > irq)
 784                         return -EINVAL;
 785                 from = irq;
 786         } else {
 787                 /*
 788                  * For interrupts which are freely allocated the
 789                  * architecture can force a lower bound to the @from
 790                  * argument. x86 uses this to exclude the GSI space.
 791                  */
 792                 from = arch_dynirq_lower_bound(from);
 793         }
 794
 795         mutex_lock(&sparse_irq_lock);
 796
 797         start = bitmap_find_next_zero_area(allocated_irqs, IRQ_BITMAP_BITS,
 798                                            from, cnt, 0);
 799         ret = -EEXIST;
 800         if (irq >=0 && start != irq)
 801                 goto unlock;
 802
 803         if (start + cnt > nr_irqs) {
 804                 ret = irq_expand_nr_irqs(start + cnt);
 805                 if (ret)
 806                         goto unlock;
 807         }
 808         ret = alloc_descs(start, cnt, node, affinity, owner);
 809 unlock:
 810         mutex_unlock(&sparse_irq_lock);
 811         return ret;
 812 }
 813 EXPORT_SYMBOL_GPL(__irq_alloc_descs);
 814
 815 /**
 816  * irq_get_next_irq - get next allocated irq number
 817  * @offset:     where to start the search
 818  *
 819  * Returns next irq number after offset or nr_irqs if none is found.
 820  */
 821 unsigned int irq_get_next_irq(unsigned int offset)
 822 {
 823         return find_next_bit(allocated_irqs, nr_irqs, offset);
 824 }
 825
 826 struct irq_desc *
 827 __irq_get_desc_lock(unsigned int irq, unsigned long *flags, bool bus,
 828                     unsigned int check)
 829 {
 830         struct irq_desc *desc = irq_to_desc(irq);
 831
 832         if (desc) {
 833                 if (check & _IRQ_DESC_CHECK) {
 834                         if ((check & _IRQ_DESC_PERCPU) &&
 835                             !irq_settings_is_per_cpu_devid(desc))
 836                                 return NULL;
 837
 838                         if (!(check & _IRQ_DESC_PERCPU) &&
 839                             irq_settings_is_per_cpu_devid(desc))
 840                                 return NULL;
 841                 }
 842
 843                 if (bus)
 844                         chip_bus_lock(desc);
 845                 raw_spin_lock_irqsave(&desc->lock, *flags);
 846         }
 847         return desc;
 848 }
 849
 850 void __irq_put_desc_unlock(struct irq_desc *desc, unsigned long flags, bool bus)
 851         __releases(&desc->lock)
 852 {
 853         raw_spin_unlock_irqrestore(&desc->lock, flags);
 854         if (bus)
 855                 chip_bus_sync_unlock(desc);
 856 }
 857
 858 int irq_set_percpu_devid_partition(unsigned int irq,
 859                                    const struct cpumask *affinity)
 860 {
 861         struct irq_desc *desc = irq_to_desc(irq);
 862
 863         if (!desc)
 864                 return -EINVAL;
 865
 866         if (desc->percpu_enabled)
 867                 return -EINVAL;
 868
 869         desc->percpu_enabled = kzalloc(sizeof(*desc->percpu_enabled), GFP_KERNEL);
 870
 871         if (!desc->percpu_enabled)
 872                 return -ENOMEM;
 873
 874         if (affinity)
 875                 desc->percpu_affinity = affinity;
 876         else
 877                 desc->percpu_affinity = cpu_possible_mask;
 878
 879         irq_set_percpu_devid_flags(irq);
 880         return 0;
 881 }
 882
 883 int irq_set_percpu_devid(unsigned int irq)
 884 {
 885         return irq_set_percpu_devid_partition(irq, NULL);
 886 }
 887
 888 int irq_get_percpu_devid_partition(unsigned int irq, struct cpumask *affinity)
 889 {
 890         struct irq_desc *desc = irq_to_desc(irq);
 891
 892         if (!desc || !desc->percpu_enabled)
 893                 return -EINVAL;
 894
 895         if (affinity)
 896                 cpumask_copy(affinity, desc->percpu_affinity);
 897
 898         return 0;
 899 }
 900 EXPORT_SYMBOL_GPL(irq_get_percpu_devid_partition);
 901
 902 void kstat_incr_irq_this_cpu(unsigned int irq)
 903 {
 904         kstat_incr_irqs_this_cpu(irq_to_desc(irq));
 905 }
 906
 907 /**
 908  * kstat_irqs_cpu - Get the statistics for an interrupt on a cpu
 909  * @irq:        The interrupt number
 910  * @cpu:        The cpu number
 911  *
 912  * Returns the sum of interrupt counts on @cpu since boot for
 913  * @irq. The caller must ensure that the interrupt is not removed
 914  * concurrently.
 915  */
 916 unsigned int kstat_irqs_cpu(unsigned int irq, int cpu)
 917 {
 918         struct irq_desc *desc = irq_to_desc(irq);
 919
 920         return desc && desc->kstat_irqs ?
 921                         *per_cpu_ptr(desc->kstat_irqs, cpu) : 0;
 922 }
 923
 924 static bool irq_is_nmi(struct irq_desc *desc)
 925 {
 926         return desc->istate & IRQS_NMI;
 927 }
 928
 929 static unsigned int kstat_irqs(unsigned int irq)
 930 {
 931         struct irq_desc *desc = irq_to_desc(irq);
 932         unsigned int sum = 0;
 933         int cpu;
 934
 935         if (!desc || !desc->kstat_irqs)
 936                 return 0;
 937         if (!irq_settings_is_per_cpu_devid(desc) &&
 938             !irq_settings_is_per_cpu(desc) &&
 939             !irq_is_nmi(desc))
 940                 return data_race(desc->tot_count);
 941
 942         for_each_possible_cpu(cpu)
 943                 sum += data_race(*per_cpu_ptr(desc->kstat_irqs, cpu));
 944         return sum;
 945 }
 946
 947 /**
 948  * kstat_irqs_usr - Get the statistics for an interrupt from thread context
 949  * @irq:        The interrupt number
 950  *
 951  * Returns the sum of interrupt counts on all cpus since boot for @irq.
 952  *
 953  * It uses rcu to protect the access since a concurrent removal of an
 954  * interrupt descriptor is observing an rcu grace period before
 955  * delayed_free_desc()/irq_kobj_release().
 956  */
 957 unsigned int kstat_irqs_usr(unsigned int irq)
 958 {
 959         unsigned int sum;
 960
 961         rcu_read_lock();
 962         sum = kstat_irqs(irq);
 963         rcu_read_unlock();
 964         return sum;
 965 }
 966
 967 #ifdef CONFIG_LOCKDEP
 968 void __irq_set_lockdep_class(unsigned int irq, struct lock_class_key *lock_class,
 969                              struct lock_class_key *request_class)
 970 {
 971         struct irq_desc *desc = irq_to_desc(irq);
 972
 973         if (desc) {
 974                 lockdep_set_class(&desc->lock, lock_class);
 975                 lockdep_set_class(&desc->request_mutex, request_class);
 976         }
 977 }
 978 EXPORT_SYMBOL_GPL(__irq_set_lockdep_class);
 979 #endif