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