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 commandline 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, "%lu\n", 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_each_action_of_desc(desc, action) {
 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 const 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 const 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 #ifdef CONFIG_KVM_BOOK3S_64_HV_MODULE
 359 EXPORT_SYMBOL_GPL(irq_to_desc);
 360 #endif
 361
 362 static void delete_irq_desc(unsigned int irq)
 363 {
 364         radix_tree_delete(&irq_desc_tree, irq);
 365 }
 366
 367 #ifdef CONFIG_SMP
 368 static void free_masks(struct irq_desc *desc)
 369 {
 370 #ifdef CONFIG_GENERIC_PENDING_IRQ
 371         free_cpumask_var(desc->pending_mask);
 372 #endif
 373         free_cpumask_var(desc->irq_common_data.affinity);
 374 #ifdef CONFIG_GENERIC_IRQ_EFFECTIVE_AFF_MASK
 375         free_cpumask_var(desc->irq_common_data.effective_affinity);
 376 #endif
 377 }
 378 #else
 379 static inline void free_masks(struct irq_desc *desc) { }
 380 #endif
 381
 382 void irq_lock_sparse(void)
 383 {
 384         mutex_lock(&sparse_irq_lock);
 385 }
 386
 387 void irq_unlock_sparse(void)
 388 {
 389         mutex_unlock(&sparse_irq_lock);
 390 }
 391
 392 static struct irq_desc *alloc_desc(int irq, int node, unsigned int flags,
 393                                    const struct cpumask *affinity,
 394                                    struct module *owner)
 395 {
 396         struct irq_desc *desc;
 397
 398         desc = kzalloc_node(sizeof(*desc), GFP_KERNEL, node);
 399         if (!desc)
 400                 return NULL;
 401         /* allocate based on nr_cpu_ids */
 402         desc->kstat_irqs = alloc_percpu(unsigned int);
 403         if (!desc->kstat_irqs)
 404                 goto err_desc;
 405
 406         if (alloc_masks(desc, node))
 407                 goto err_kstat;
 408
 409         raw_spin_lock_init(&desc->lock);
 410         lockdep_set_class(&desc->lock, &irq_desc_lock_class);
 411         mutex_init(&desc->request_mutex);
 412         init_rcu_head(&desc->rcu);
 413         init_waitqueue_head(&desc->wait_for_threads);
 414
 415         desc_set_defaults(irq, desc, node, affinity, owner);
 416         irqd_set(&desc->irq_data, flags);
 417         kobject_init(&desc->kobj, &irq_kobj_type);
 418
 419         return desc;
 420
 421 err_kstat:
 422         free_percpu(desc->kstat_irqs);
 423 err_desc:
 424         kfree(desc);
 425         return NULL;
 426 }
 427
 428 static void irq_kobj_release(struct kobject *kobj)
 429 {
 430         struct irq_desc *desc = container_of(kobj, struct irq_desc, kobj);
 431
 432         free_masks(desc);
 433         free_percpu(desc->kstat_irqs);
 434         kfree(desc);
 435 }
 436
 437 static void delayed_free_desc(struct rcu_head *rhp)
 438 {
 439         struct irq_desc *desc = container_of(rhp, struct irq_desc, rcu);
 440
 441         kobject_put(&desc->kobj);
 442 }
 443
 444 static void free_desc(unsigned int irq)
 445 {
 446         struct irq_desc *desc = irq_to_desc(irq);
 447
 448         irq_remove_debugfs_entry(desc);
 449         unregister_irq_proc(irq, desc);
 450
 451         /*
 452          * sparse_irq_lock protects also show_interrupts() and
 453          * kstat_irq_usr(). Once we deleted the descriptor from the
 454          * sparse tree we can free it. Access in proc will fail to
 455          * lookup the descriptor.
 456          *
 457          * The sysfs entry must be serialized against a concurrent
 458          * irq_sysfs_init() as well.
 459          */
 460         irq_sysfs_del(desc);
 461         delete_irq_desc(irq);
 462
 463         /*
 464          * We free the descriptor, masks and stat fields via RCU. That
 465          * allows demultiplex interrupts to do rcu based management of
 466          * the child interrupts.
 467          * This also allows us to use rcu in kstat_irqs_usr().
 468          */
 469         call_rcu(&desc->rcu, delayed_free_desc);
 470 }
 471
 472 static int alloc_descs(unsigned int start, unsigned int cnt, int node,
 473                        const struct irq_affinity_desc *affinity,
 474                        struct module *owner)
 475 {
 476         struct irq_desc *desc;
 477         int i;
 478
 479         /* Validate affinity mask(s) */
 480         if (affinity) {
 481                 for (i = 0; i < cnt; i++) {
 482                         if (cpumask_empty(&affinity[i].mask))
 483                                 return -EINVAL;
 484                 }
 485         }
 486
 487         for (i = 0; i < cnt; i++) {
 488                 const struct cpumask *mask = NULL;
 489                 unsigned int flags = 0;
 490
 491                 if (affinity) {
 492                         if (affinity->is_managed) {
 493                                 flags = IRQD_AFFINITY_MANAGED |
 494                                         IRQD_MANAGED_SHUTDOWN;
 495                         }
 496                         mask = &affinity->mask;
 497                         node = cpu_to_node(cpumask_first(mask));
 498                         affinity++;
 499                 }
 500
 501                 desc = alloc_desc(start + i, node, flags, mask, owner);
 502                 if (!desc)
 503                         goto err;
 504                 irq_insert_desc(start + i, desc);
 505                 irq_sysfs_add(start + i, desc);
 506                 irq_add_debugfs_entry(start + i, desc);
 507         }
 508         bitmap_set(allocated_irqs, start, cnt);
 509         return start;
 510
 511 err:
 512         for (i--; i >= 0; i--)
 513                 free_desc(start + i);
 514         return -ENOMEM;
 515 }
 516
 517 static int irq_expand_nr_irqs(unsigned int nr)
 518 {
 519         if (nr > IRQ_BITMAP_BITS)
 520                 return -ENOMEM;
 521         nr_irqs = nr;
 522         return 0;
 523 }
 524
 525 int __init early_irq_init(void)
 526 {
 527         int i, initcnt, node = first_online_node;
 528         struct irq_desc *desc;
 529
 530         init_irq_default_affinity();
 531
 532         /* Let arch update nr_irqs and return the nr of preallocated irqs */
 533         initcnt = arch_probe_nr_irqs();
 534         printk(KERN_INFO "NR_IRQS: %d, nr_irqs: %d, preallocated irqs: %d\n",
 535                NR_IRQS, nr_irqs, initcnt);
 536
 537         if (WARN_ON(nr_irqs > IRQ_BITMAP_BITS))
 538                 nr_irqs = IRQ_BITMAP_BITS;
 539
 540         if (WARN_ON(initcnt > IRQ_BITMAP_BITS))
 541                 initcnt = IRQ_BITMAP_BITS;
 542
 543         if (initcnt > nr_irqs)
 544                 nr_irqs = initcnt;
 545
 546         for (i = 0; i < initcnt; i++) {
 547                 desc = alloc_desc(i, node, 0, NULL, NULL);
 548                 set_bit(i, allocated_irqs);
 549                 irq_insert_desc(i, desc);
 550         }
 551         return arch_early_irq_init();
 552 }
 553
 554 #else /* !CONFIG_SPARSE_IRQ */
 555
 556 struct irq_desc irq_desc[NR_IRQS] __cacheline_aligned_in_smp = {
 557         [0 ... NR_IRQS-1] = {
 558                 .handle_irq     = handle_bad_irq,
 559                 .depth          = 1,
 560                 .lock           = __RAW_SPIN_LOCK_UNLOCKED(irq_desc->lock),
 561         }
 562 };
 563
 564 int __init early_irq_init(void)
 565 {
 566         int count, i, node = first_online_node;
 567         struct irq_desc *desc;
 568
 569         init_irq_default_affinity();
 570
 571         printk(KERN_INFO "NR_IRQS: %d\n", NR_IRQS);
 572
 573         desc = irq_desc;
 574         count = ARRAY_SIZE(irq_desc);
 575
 576         for (i = 0; i < count; i++) {
 577                 desc[i].kstat_irqs = alloc_percpu(unsigned int);
 578                 alloc_masks(&desc[i], node);
 579                 raw_spin_lock_init(&desc[i].lock);
 580                 lockdep_set_class(&desc[i].lock, &irq_desc_lock_class);
 581                 mutex_init(&desc[i].request_mutex);
 582                 init_waitqueue_head(&desc[i].wait_for_threads);
 583                 desc_set_defaults(i, &desc[i], node, NULL, NULL);
 584         }
 585         return arch_early_irq_init();
 586 }
 587
 588 struct irq_desc *irq_to_desc(unsigned int irq)
 589 {
 590         return (irq < NR_IRQS) ? irq_desc + irq : NULL;
 591 }
 592 EXPORT_SYMBOL(irq_to_desc);
 593
 594 static void free_desc(unsigned int irq)
 595 {
 596         struct irq_desc *desc = irq_to_desc(irq);
 597         unsigned long flags;
 598
 599         raw_spin_lock_irqsave(&desc->lock, flags);
 600         desc_set_defaults(irq, desc, irq_desc_get_node(desc), NULL, NULL);
 601         raw_spin_unlock_irqrestore(&desc->lock, flags);
 602 }
 603
 604 static inline int alloc_descs(unsigned int start, unsigned int cnt, int node,
 605                               const struct irq_affinity_desc *affinity,
 606                               struct module *owner)
 607 {
 608         u32 i;
 609
 610         for (i = 0; i < cnt; i++) {
 611                 struct irq_desc *desc = irq_to_desc(start + i);
 612
 613                 desc->owner = owner;
 614         }
 615         bitmap_set(allocated_irqs, start, cnt);
 616         return start;
 617 }
 618
 619 static int irq_expand_nr_irqs(unsigned int nr)
 620 {
 621         return -ENOMEM;
 622 }
 623
 624 void irq_mark_irq(unsigned int irq)
 625 {
 626         mutex_lock(&sparse_irq_lock);
 627         bitmap_set(allocated_irqs, irq, 1);
 628         mutex_unlock(&sparse_irq_lock);
 629 }
 630
 631 #ifdef CONFIG_GENERIC_IRQ_LEGACY
 632 void irq_init_desc(unsigned int irq)
 633 {
 634         free_desc(irq);
 635 }
 636 #endif
 637
 638 #endif /* !CONFIG_SPARSE_IRQ */
 639
 640 int handle_irq_desc(struct irq_desc *desc)
 641 {
 642         struct irq_data *data;
 643
 644         if (!desc)
 645                 return -EINVAL;
 646
 647         data = irq_desc_get_irq_data(desc);
 648         if (WARN_ON_ONCE(!in_hardirq() && handle_enforce_irqctx(data)))
 649                 return -EPERM;
 650
 651         generic_handle_irq_desc(desc);
 652         return 0;
 653 }
 654
 655 /**
 656  * generic_handle_irq - Invoke the handler for a particular irq
 657  * @irq:        The irq number to handle
 658  *
 659  * Returns:     0 on success, or -EINVAL if conversion has failed
 660  *
 661  *              This function must be called from an IRQ context with irq regs
 662  *              initialized.
 663   */
 664 int generic_handle_irq(unsigned int irq)
 665 {
 666         return handle_irq_desc(irq_to_desc(irq));
 667 }
 668 EXPORT_SYMBOL_GPL(generic_handle_irq);
 669
 670 /**
 671  * generic_handle_irq_safe - Invoke the handler for a particular irq from any
 672  *                           context.
 673  * @irq:        The irq number to handle
 674  *
 675  * Returns:     0 on success, a negative value on error.
 676  *
 677  * This function can be called from any context (IRQ or process context). It
 678  * will report an error if not invoked from IRQ context and the irq has been
 679  * marked to enforce IRQ-context only.
 680  */
 681 int generic_handle_irq_safe(unsigned int irq)
 682 {
 683         unsigned long flags;
 684         int ret;
 685
 686         local_irq_save(flags);
 687         ret = handle_irq_desc(irq_to_desc(irq));
 688         local_irq_restore(flags);
 689         return ret;
 690 }
 691 EXPORT_SYMBOL_GPL(generic_handle_irq_safe);
 692
 693 #ifdef CONFIG_IRQ_DOMAIN
 694 /**
 695  * generic_handle_domain_irq - Invoke the handler for a HW irq belonging
 696  *                             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  *
 700  * Returns:     0 on success, or -EINVAL if conversion has failed
 701  *
 702  *              This function must be called from an IRQ context with irq regs
 703  *              initialized.
 704  */
 705 int generic_handle_domain_irq(struct irq_domain *domain, unsigned int hwirq)
 706 {
 707         return handle_irq_desc(irq_resolve_mapping(domain, hwirq));
 708 }
 709 EXPORT_SYMBOL_GPL(generic_handle_domain_irq);
 710
 711  /**
 712  * generic_handle_irq_safe - Invoke the handler for a HW irq belonging
 713  *                           to a domain from any context.
 714  * @domain:     The domain where to perform the lookup
 715  * @hwirq:      The HW irq number to convert to a logical one
 716  *
 717  * Returns:     0 on success, a negative value on error.
 718  *
 719  * This function can be called from any context (IRQ or process
 720  * context). If the interrupt is marked as 'enforce IRQ-context only' then
 721  * the function must be invoked from hard interrupt context.
 722  */
 723 int generic_handle_domain_irq_safe(struct irq_domain *domain, unsigned int hwirq)
 724 {
 725         unsigned long flags;
 726         int ret;
 727
 728         local_irq_save(flags);
 729         ret = handle_irq_desc(irq_resolve_mapping(domain, hwirq));
 730         local_irq_restore(flags);
 731         return ret;
 732 }
 733 EXPORT_SYMBOL_GPL(generic_handle_domain_irq_safe);
 734
 735 /**
 736  * generic_handle_domain_nmi - Invoke the handler for a HW nmi belonging
 737  *                             to a domain.
 738  * @domain:     The domain where to perform the lookup
 739  * @hwirq:      The HW irq number to convert to a logical one
 740  *
 741  * Returns:     0 on success, or -EINVAL if conversion has failed
 742  *
 743  *              This function must be called from an NMI context with irq regs
 744  *              initialized.
 745  **/
 746 int generic_handle_domain_nmi(struct irq_domain *domain, unsigned int hwirq)
 747 {
 748         WARN_ON_ONCE(!in_nmi());
 749         return handle_irq_desc(irq_resolve_mapping(domain, hwirq));
 750 }
 751 #endif
 752
 753 /* Dynamic interrupt handling */
 754
 755 /**
 756  * irq_free_descs - free irq descriptors
 757  * @from:       Start of descriptor range
 758  * @cnt:        Number of consecutive irqs to free
 759  */
 760 void irq_free_descs(unsigned int from, unsigned int cnt)
 761 {
 762         int i;
 763
 764         if (from >= nr_irqs || (from + cnt) > nr_irqs)
 765                 return;
 766
 767         mutex_lock(&sparse_irq_lock);
 768         for (i = 0; i < cnt; i++)
 769                 free_desc(from + i);
 770
 771         bitmap_clear(allocated_irqs, from, cnt);
 772         mutex_unlock(&sparse_irq_lock);
 773 }
 774 EXPORT_SYMBOL_GPL(irq_free_descs);
 775
 776 /**
 777  * __irq_alloc_descs - allocate and initialize a range of irq descriptors
 778  * @irq:        Allocate for specific irq number if irq >= 0
 779  * @from:       Start the search from this irq number
 780  * @cnt:        Number of consecutive irqs to allocate.
 781  * @node:       Preferred node on which the irq descriptor should be allocated
 782  * @owner:      Owning module (can be NULL)
 783  * @affinity:   Optional pointer to an affinity mask array of size @cnt which
 784  *              hints where the irq descriptors should be allocated and which
 785  *              default affinities to use
 786  *
 787  * Returns the first irq number or error code
 788  */
 789 int __ref
 790 __irq_alloc_descs(int irq, unsigned int from, unsigned int cnt, int node,
 791                   struct module *owner, const struct irq_affinity_desc *affinity)
 792 {
 793         int start, ret;
 794
 795         if (!cnt)
 796                 return -EINVAL;
 797
 798         if (irq >= 0) {
 799                 if (from > irq)
 800                         return -EINVAL;
 801                 from = irq;
 802         } else {
 803                 /*
 804                  * For interrupts which are freely allocated the
 805                  * architecture can force a lower bound to the @from
 806                  * argument. x86 uses this to exclude the GSI space.
 807                  */
 808                 from = arch_dynirq_lower_bound(from);
 809         }
 810
 811         mutex_lock(&sparse_irq_lock);
 812
 813         start = bitmap_find_next_zero_area(allocated_irqs, IRQ_BITMAP_BITS,
 814                                            from, cnt, 0);
 815         ret = -EEXIST;
 816         if (irq >=0 && start != irq)
 817                 goto unlock;
 818
 819         if (start + cnt > nr_irqs) {
 820                 ret = irq_expand_nr_irqs(start + cnt);
 821                 if (ret)
 822                         goto unlock;
 823         }
 824         ret = alloc_descs(start, cnt, node, affinity, owner);
 825 unlock:
 826         mutex_unlock(&sparse_irq_lock);
 827         return ret;
 828 }
 829 EXPORT_SYMBOL_GPL(__irq_alloc_descs);
 830
 831 /**
 832  * irq_get_next_irq - get next allocated irq number
 833  * @offset:     where to start the search
 834  *
 835  * Returns next irq number after offset or nr_irqs if none is found.
 836  */
 837 unsigned int irq_get_next_irq(unsigned int offset)
 838 {
 839         return find_next_bit(allocated_irqs, nr_irqs, offset);
 840 }
 841
 842 struct irq_desc *
 843 __irq_get_desc_lock(unsigned int irq, unsigned long *flags, bool bus,
 844                     unsigned int check)
 845 {
 846         struct irq_desc *desc = irq_to_desc(irq);
 847
 848         if (desc) {
 849                 if (check & _IRQ_DESC_CHECK) {
 850                         if ((check & _IRQ_DESC_PERCPU) &&
 851                             !irq_settings_is_per_cpu_devid(desc))
 852                                 return NULL;
 853
 854                         if (!(check & _IRQ_DESC_PERCPU) &&
 855                             irq_settings_is_per_cpu_devid(desc))
 856                                 return NULL;
 857                 }
 858
 859                 if (bus)
 860                         chip_bus_lock(desc);
 861                 raw_spin_lock_irqsave(&desc->lock, *flags);
 862         }
 863         return desc;
 864 }
 865
 866 void __irq_put_desc_unlock(struct irq_desc *desc, unsigned long flags, bool bus)
 867         __releases(&desc->lock)
 868 {
 869         raw_spin_unlock_irqrestore(&desc->lock, flags);
 870         if (bus)
 871                 chip_bus_sync_unlock(desc);
 872 }
 873
 874 int irq_set_percpu_devid_partition(unsigned int irq,
 875                                    const struct cpumask *affinity)
 876 {
 877         struct irq_desc *desc = irq_to_desc(irq);
 878
 879         if (!desc)
 880                 return -EINVAL;
 881
 882         if (desc->percpu_enabled)
 883                 return -EINVAL;
 884
 885         desc->percpu_enabled = kzalloc(sizeof(*desc->percpu_enabled), GFP_KERNEL);
 886
 887         if (!desc->percpu_enabled)
 888                 return -ENOMEM;
 889
 890         if (affinity)
 891                 desc->percpu_affinity = affinity;
 892         else
 893                 desc->percpu_affinity = cpu_possible_mask;
 894
 895         irq_set_percpu_devid_flags(irq);
 896         return 0;
 897 }
 898
 899 int irq_set_percpu_devid(unsigned int irq)
 900 {
 901         return irq_set_percpu_devid_partition(irq, NULL);
 902 }
 903
 904 int irq_get_percpu_devid_partition(unsigned int irq, struct cpumask *affinity)
 905 {
 906         struct irq_desc *desc = irq_to_desc(irq);
 907
 908         if (!desc || !desc->percpu_enabled)
 909                 return -EINVAL;
 910
 911         if (affinity)
 912                 cpumask_copy(affinity, desc->percpu_affinity);
 913
 914         return 0;
 915 }
 916 EXPORT_SYMBOL_GPL(irq_get_percpu_devid_partition);
 917
 918 void kstat_incr_irq_this_cpu(unsigned int irq)
 919 {
 920         kstat_incr_irqs_this_cpu(irq_to_desc(irq));
 921 }
 922
 923 /**
 924  * kstat_irqs_cpu - Get the statistics for an interrupt on a cpu
 925  * @irq:        The interrupt number
 926  * @cpu:        The cpu number
 927  *
 928  * Returns the sum of interrupt counts on @cpu since boot for
 929  * @irq. The caller must ensure that the interrupt is not removed
 930  * concurrently.
 931  */
 932 unsigned int kstat_irqs_cpu(unsigned int irq, int cpu)
 933 {
 934         struct irq_desc *desc = irq_to_desc(irq);
 935
 936         return desc && desc->kstat_irqs ?
 937                         *per_cpu_ptr(desc->kstat_irqs, cpu) : 0;
 938 }
 939
 940 static bool irq_is_nmi(struct irq_desc *desc)
 941 {
 942         return desc->istate & IRQS_NMI;
 943 }
 944
 945 static unsigned int kstat_irqs(unsigned int irq)
 946 {
 947         struct irq_desc *desc = irq_to_desc(irq);
 948         unsigned int sum = 0;
 949         int cpu;
 950
 951         if (!desc || !desc->kstat_irqs)
 952                 return 0;
 953         if (!irq_settings_is_per_cpu_devid(desc) &&
 954             !irq_settings_is_per_cpu(desc) &&
 955             !irq_is_nmi(desc))
 956                 return data_race(desc->tot_count);
 957
 958         for_each_possible_cpu(cpu)
 959                 sum += data_race(*per_cpu_ptr(desc->kstat_irqs, cpu));
 960         return sum;
 961 }
 962
 963 /**
 964  * kstat_irqs_usr - Get the statistics for an interrupt from thread context
 965  * @irq:        The interrupt number
 966  *
 967  * Returns the sum of interrupt counts on all cpus since boot for @irq.
 968  *
 969  * It uses rcu to protect the access since a concurrent removal of an
 970  * interrupt descriptor is observing an rcu grace period before
 971  * delayed_free_desc()/irq_kobj_release().
 972  */
 973 unsigned int kstat_irqs_usr(unsigned int irq)
 974 {
 975         unsigned int sum;
 976
 977         rcu_read_lock();
 978         sum = kstat_irqs(irq);
 979         rcu_read_unlock();
 980         return sum;
 981 }
 982
 983 #ifdef CONFIG_LOCKDEP
 984 void __irq_set_lockdep_class(unsigned int irq, struct lock_class_key *lock_class,
 985                              struct lock_class_key *request_class)
 986 {
 987         struct irq_desc *desc = irq_to_desc(irq);
 988
 989         if (desc) {
 990                 lockdep_set_class(&desc->lock, lock_class);
 991                 lockdep_set_class(&desc->request_mutex, request_class);
 992         }
 993 }
 994 EXPORT_SYMBOL_GPL(__irq_set_lockdep_class);
 995 #endif