kernel/irq/irqdesc.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * Copyright (C) 1992, 1998-2006 Linus Torvalds, Ingo Molnar
   4  * Copyright (C) 2005-2006, Thomas Gleixner, Russell King
   5  *
   6  * This file contains the interrupt descriptor management code. Detailed
   7  * information is available in Documentation/core-api/genericirq.rst
   8  *
   9  */
  10 #include <linux/irq.h>
  11 #include <linux/slab.h>
  12 #include <linux/export.h>
  13 #include <linux/interrupt.h>
  14 #include <linux/kernel_stat.h>
  15 #include <linux/radix-tree.h>
  16 #include <linux/bitmap.h>
  17 #include <linux/irqdomain.h>
  18 #include <linux/sysfs.h>
  19
  20 #include "internals.h"
  21
  22 /*
  23  * lockdep: we want to handle all irq_desc locks as a single lock-class:
  24  */
  25 static struct lock_class_key irq_desc_lock_class;
  26
  27 #if defined(CONFIG_SMP)
  28 static int __init irq_affinity_setup(char *str)
  29 {
  30         alloc_bootmem_cpumask_var(&irq_default_affinity);
  31         cpulist_parse(str, irq_default_affinity);
  32         /*
  33          * Set at least the boot cpu. We don't want to end up with
  34          * bugreports caused by random comandline masks
  35          */
  36         cpumask_set_cpu(smp_processor_id(), irq_default_affinity);
  37         return 1;
  38 }
  39 __setup("irqaffinity=", irq_affinity_setup);
  40
  41 static void __init init_irq_default_affinity(void)
  42 {
  43         if (!cpumask_available(irq_default_affinity))
  44                 zalloc_cpumask_var(&irq_default_affinity, GFP_NOWAIT);
  45         if (cpumask_empty(irq_default_affinity))
  46                 cpumask_setall(irq_default_affinity);
  47 }
  48 #else
  49 static void __init init_irq_default_affinity(void)
  50 {
  51 }
  52 #endif
  53
  54 #ifdef CONFIG_SMP
  55 static int alloc_masks(struct irq_desc *desc, int node)
  56 {
  57         if (!zalloc_cpumask_var_node(&desc->irq_common_data.affinity,
  58                                      GFP_KERNEL, node))
  59                 return -ENOMEM;
  60
  61 #ifdef CONFIG_GENERIC_IRQ_EFFECTIVE_AFF_MASK
  62         if (!zalloc_cpumask_var_node(&desc->irq_common_data.effective_affinity,
  63                                      GFP_KERNEL, node)) {
  64                 free_cpumask_var(desc->irq_common_data.affinity);
  65                 return -ENOMEM;
  66         }
  67 #endif
  68
  69 #ifdef CONFIG_GENERIC_PENDING_IRQ
  70         if (!zalloc_cpumask_var_node(&desc->pending_mask, GFP_KERNEL, node)) {
  71 #ifdef CONFIG_GENERIC_IRQ_EFFECTIVE_AFF_MASK
  72                 free_cpumask_var(desc->irq_common_data.effective_affinity);
  73 #endif
  74                 free_cpumask_var(desc->irq_common_data.affinity);
  75                 return -ENOMEM;
  76         }
  77 #endif
  78         return 0;
  79 }
  80
  81 static void desc_smp_init(struct irq_desc *desc, int node,
  82                           const struct cpumask *affinity)
  83 {
  84         if (!affinity)
  85                 affinity = irq_default_affinity;
  86         cpumask_copy(desc->irq_common_data.affinity, affinity);
  87
  88 #ifdef CONFIG_GENERIC_PENDING_IRQ
  89         cpumask_clear(desc->pending_mask);
  90 #endif
  91 #ifdef CONFIG_NUMA
  92         desc->irq_common_data.node = node;
  93 #endif
  94 }
  95
  96 #else
  97 static inline int
  98 alloc_masks(struct irq_desc *desc, int node) { return 0; }
  99 static inline void
 100 desc_smp_init(struct irq_desc *desc, int node, const struct cpumask *affinity) { }
 101 #endif
 102
 103 static void desc_set_defaults(unsigned int irq, struct irq_desc *desc, int node,
 104                               const struct cpumask *affinity, struct module *owner)
 105 {
 106         int cpu;
 107
 108         desc->irq_common_data.handler_data = NULL;
 109         desc->irq_common_data.msi_desc = NULL;
 110
 111         desc->irq_data.common = &desc->irq_common_data;
 112         desc->irq_data.irq = irq;
 113         desc->irq_data.chip = &no_irq_chip;
 114         desc->irq_data.chip_data = NULL;
 115         irq_settings_clr_and_set(desc, ~0, _IRQ_DEFAULT_INIT_FLAGS);
 116         irqd_set(&desc->irq_data, IRQD_IRQ_DISABLED);
 117         irqd_set(&desc->irq_data, IRQD_IRQ_MASKED);
 118         desc->handle_irq = handle_bad_irq;
 119         desc->depth = 1;
 120         desc->irq_count = 0;
 121         desc->irqs_unhandled = 0;
 122         desc->name = NULL;
 123         desc->owner = owner;
 124         for_each_possible_cpu(cpu)
 125                 *per_cpu_ptr(desc->kstat_irqs, cpu) = 0;
 126         desc_smp_init(desc, node, affinity);
 127 }
 128
 129 int nr_irqs = NR_IRQS;
 130 EXPORT_SYMBOL_GPL(nr_irqs);
 131
 132 static DEFINE_MUTEX(sparse_irq_lock);
 133 static DECLARE_BITMAP(allocated_irqs, IRQ_BITMAP_BITS);
 134
 135 #ifdef CONFIG_SPARSE_IRQ
 136
 137 static void irq_kobj_release(struct kobject *kobj);
 138
 139 #ifdef CONFIG_SYSFS
 140 static struct kobject *irq_kobj_base;
 141
 142 #define IRQ_ATTR_RO(_name) \
 143 static struct kobj_attribute _name##_attr = __ATTR_RO(_name)
 144
 145 static ssize_t per_cpu_count_show(struct kobject *kobj,
 146                                   struct kobj_attribute *attr, char *buf)
 147 {
 148         struct irq_desc *desc = container_of(kobj, struct irq_desc, kobj);
 149         int cpu, irq = desc->irq_data.irq;
 150         ssize_t ret = 0;
 151         char *p = "";
 152
 153         for_each_possible_cpu(cpu) {
 154                 unsigned int c = kstat_irqs_cpu(irq, cpu);
 155
 156                 ret += scnprintf(buf + ret, PAGE_SIZE - ret, "%s%u", p, c);
 157                 p = ",";
 158         }
 159
 160         ret += scnprintf(buf + ret, PAGE_SIZE - ret, "\n");
 161         return ret;
 162 }
 163 IRQ_ATTR_RO(per_cpu_count);
 164
 165 static ssize_t chip_name_show(struct kobject *kobj,
 166                               struct kobj_attribute *attr, char *buf)
 167 {
 168         struct irq_desc *desc = container_of(kobj, struct irq_desc, kobj);
 169         ssize_t ret = 0;
 170
 171         raw_spin_lock_irq(&desc->lock);
 172         if (desc->irq_data.chip && desc->irq_data.chip->name) {
 173                 ret = scnprintf(buf, PAGE_SIZE, "%s\n",
 174                                 desc->irq_data.chip->name);
 175         }
 176         raw_spin_unlock_irq(&desc->lock);
 177
 178         return ret;
 179 }
 180 IRQ_ATTR_RO(chip_name);
 181
 182 static ssize_t hwirq_show(struct kobject *kobj,
 183                           struct kobj_attribute *attr, char *buf)
 184 {
 185         struct irq_desc *desc = container_of(kobj, struct irq_desc, kobj);
 186         ssize_t ret = 0;
 187
 188         raw_spin_lock_irq(&desc->lock);
 189         if (desc->irq_data.domain)
 190                 ret = sprintf(buf, "%d\n", (int)desc->irq_data.hwirq);
 191         raw_spin_unlock_irq(&desc->lock);
 192
 193         return ret;
 194 }
 195 IRQ_ATTR_RO(hwirq);
 196
 197 static ssize_t type_show(struct kobject *kobj,
 198                          struct kobj_attribute *attr, char *buf)
 199 {
 200         struct irq_desc *desc = container_of(kobj, struct irq_desc, kobj);
 201         ssize_t ret = 0;
 202
 203         raw_spin_lock_irq(&desc->lock);
 204         ret = sprintf(buf, "%s\n",
 205                       irqd_is_level_type(&desc->irq_data) ? "level" : "edge");
 206         raw_spin_unlock_irq(&desc->lock);
 207
 208         return ret;
 209
 210 }
 211 IRQ_ATTR_RO(type);
 212
 213 static ssize_t wakeup_show(struct kobject *kobj,
 214                            struct kobj_attribute *attr, char *buf)
 215 {
 216         struct irq_desc *desc = container_of(kobj, struct irq_desc, kobj);
 217         ssize_t ret = 0;
 218
 219         raw_spin_lock_irq(&desc->lock);
 220         ret = sprintf(buf, "%s\n",
 221                       irqd_is_wakeup_set(&desc->irq_data) ? "enabled" : "disabled");
 222         raw_spin_unlock_irq(&desc->lock);
 223
 224         return ret;
 225
 226 }
 227 IRQ_ATTR_RO(wakeup);
 228
 229 static ssize_t name_show(struct kobject *kobj,
 230                          struct kobj_attribute *attr, char *buf)
 231 {
 232         struct irq_desc *desc = container_of(kobj, struct irq_desc, kobj);
 233         ssize_t ret = 0;
 234
 235         raw_spin_lock_irq(&desc->lock);
 236         if (desc->name)
 237                 ret = scnprintf(buf, PAGE_SIZE, "%s\n", desc->name);
 238         raw_spin_unlock_irq(&desc->lock);
 239
 240         return ret;
 241 }
 242 IRQ_ATTR_RO(name);
 243
 244 static ssize_t actions_show(struct kobject *kobj,
 245                             struct kobj_attribute *attr, char *buf)
 246 {
 247         struct irq_desc *desc = container_of(kobj, struct irq_desc, kobj);
 248         struct irqaction *action;
 249         ssize_t ret = 0;
 250         char *p = "";
 251
 252         raw_spin_lock_irq(&desc->lock);
 253         for (action = desc->action; action != NULL; action = action->next) {
 254                 ret += scnprintf(buf + ret, PAGE_SIZE - ret, "%s%s",
 255                                  p, action->name);
 256                 p = ",";
 257         }
 258         raw_spin_unlock_irq(&desc->lock);
 259
 260         if (ret)
 261                 ret += scnprintf(buf + ret, PAGE_SIZE - ret, "\n");
 262
 263         return ret;
 264 }
 265 IRQ_ATTR_RO(actions);
 266
 267 static struct attribute *irq_attrs[] = {
 268         &per_cpu_count_attr.attr,
 269         &chip_name_attr.attr,
 270         &hwirq_attr.attr,
 271         &type_attr.attr,
 272         &wakeup_attr.attr,
 273         &name_attr.attr,
 274         &actions_attr.attr,
 275         NULL
 276 };
 277
 278 static struct kobj_type irq_kobj_type = {
 279         .release        = irq_kobj_release,
 280         .sysfs_ops      = &kobj_sysfs_ops,
 281         .default_attrs  = irq_attrs,
 282 };
 283
 284 static void irq_sysfs_add(int irq, struct irq_desc *desc)
 285 {
 286         if (irq_kobj_base) {
 287                 /*
 288                  * Continue even in case of failure as this is nothing
 289                  * crucial.
 290                  */
 291                 if (kobject_add(&desc->kobj, irq_kobj_base, "%d", irq))
 292                         pr_warn("Failed to add kobject for irq %d\n", irq);
 293         }
 294 }
 295
 296 static int __init irq_sysfs_init(void)
 297 {
 298         struct irq_desc *desc;
 299         int irq;
 300
 301         /* Prevent concurrent irq alloc/free */
 302         irq_lock_sparse();
 303
 304         irq_kobj_base = kobject_create_and_add("irq", kernel_kobj);
 305         if (!irq_kobj_base) {
 306                 irq_unlock_sparse();
 307                 return -ENOMEM;
 308         }
 309
 310         /* Add the already allocated interrupts */
 311         for_each_irq_desc(irq, desc)
 312                 irq_sysfs_add(irq, desc);
 313         irq_unlock_sparse();
 314
 315         return 0;
 316 }
 317 postcore_initcall(irq_sysfs_init);
 318
 319 #else /* !CONFIG_SYSFS */
 320
 321 static struct kobj_type irq_kobj_type = {
 322         .release        = irq_kobj_release,
 323 };
 324
 325 static void irq_sysfs_add(int irq, struct irq_desc *desc) {}
 326
 327 #endif /* CONFIG_SYSFS */
 328
 329 static RADIX_TREE(irq_desc_tree, GFP_KERNEL);
 330
 331 static void irq_insert_desc(unsigned int irq, struct irq_desc *desc)
 332 {
 333         radix_tree_insert(&irq_desc_tree, irq, desc);
 334 }
 335
 336 struct irq_desc *irq_to_desc(unsigned int irq)
 337 {
 338         return radix_tree_lookup(&irq_desc_tree, irq);
 339 }
 340 EXPORT_SYMBOL(irq_to_desc);
 341
 342 static void delete_irq_desc(unsigned int irq)
 343 {
 344         radix_tree_delete(&irq_desc_tree, irq);
 345 }
 346
 347 #ifdef CONFIG_SMP
 348 static void free_masks(struct irq_desc *desc)
 349 {
 350 #ifdef CONFIG_GENERIC_PENDING_IRQ
 351         free_cpumask_var(desc->pending_mask);
 352 #endif
 353         free_cpumask_var(desc->irq_common_data.affinity);
 354 #ifdef CONFIG_GENERIC_IRQ_EFFECTIVE_AFF_MASK
 355         free_cpumask_var(desc->irq_common_data.effective_affinity);
 356 #endif
 357 }
 358 #else
 359 static inline void free_masks(struct irq_desc *desc) { }
 360 #endif
 361
 362 void irq_lock_sparse(void)
 363 {
 364         mutex_lock(&sparse_irq_lock);
 365 }
 366
 367 void irq_unlock_sparse(void)
 368 {
 369         mutex_unlock(&sparse_irq_lock);
 370 }
 371
 372 static struct irq_desc *alloc_desc(int irq, int node, unsigned int flags,
 373                                    const struct cpumask *affinity,
 374                                    struct module *owner)
 375 {
 376         struct irq_desc *desc;
 377
 378         desc = kzalloc_node(sizeof(*desc), GFP_KERNEL, node);
 379         if (!desc)
 380                 return NULL;
 381         /* allocate based on nr_cpu_ids */
 382         desc->kstat_irqs = alloc_percpu(unsigned int);
 383         if (!desc->kstat_irqs)
 384                 goto err_desc;
 385
 386         if (alloc_masks(desc, node))
 387                 goto err_kstat;
 388
 389         raw_spin_lock_init(&desc->lock);
 390         lockdep_set_class(&desc->lock, &irq_desc_lock_class);
 391         mutex_init(&desc->request_mutex);
 392         init_rcu_head(&desc->rcu);
 393
 394         desc_set_defaults(irq, desc, node, affinity, owner);
 395         irqd_set(&desc->irq_data, flags);
 396         kobject_init(&desc->kobj, &irq_kobj_type);
 397
 398         return desc;
 399
 400 err_kstat:
 401         free_percpu(desc->kstat_irqs);
 402 err_desc:
 403         kfree(desc);
 404         return NULL;
 405 }
 406
 407 static void irq_kobj_release(struct kobject *kobj)
 408 {
 409         struct irq_desc *desc = container_of(kobj, struct irq_desc, kobj);
 410
 411         free_masks(desc);
 412         free_percpu(desc->kstat_irqs);
 413         kfree(desc);
 414 }
 415
 416 static void delayed_free_desc(struct rcu_head *rhp)
 417 {
 418         struct irq_desc *desc = container_of(rhp, struct irq_desc, rcu);
 419
 420         kobject_put(&desc->kobj);
 421 }
 422
 423 static void free_desc(unsigned int irq)
 424 {
 425         struct irq_desc *desc = irq_to_desc(irq);
 426
 427         irq_remove_debugfs_entry(desc);
 428         unregister_irq_proc(irq, desc);
 429
 430         /*
 431          * sparse_irq_lock protects also show_interrupts() and
 432          * kstat_irq_usr(). Once we deleted the descriptor from the
 433          * sparse tree we can free it. Access in proc will fail to
 434          * lookup the descriptor.
 435          *
 436          * The sysfs entry must be serialized against a concurrent
 437          * irq_sysfs_init() as well.
 438          */
 439         kobject_del(&desc->kobj);
 440         delete_irq_desc(irq);
 441
 442         /*
 443          * We free the descriptor, masks and stat fields via RCU. That
 444          * allows demultiplex interrupts to do rcu based management of
 445          * the child interrupts.
 446          * This also allows us to use rcu in kstat_irqs_usr().
 447          */
 448         call_rcu(&desc->rcu, delayed_free_desc);
 449 }
 450
 451 static int alloc_descs(unsigned int start, unsigned int cnt, int node,
 452                        const struct cpumask *affinity, struct module *owner)
 453 {
 454         const struct cpumask *mask = NULL;
 455         struct irq_desc *desc;
 456         unsigned int flags;
 457         int i;
 458
 459         /* Validate affinity mask(s) */
 460         if (affinity) {
 461                 for (i = 0, mask = affinity; i < cnt; i++, mask++) {
 462                         if (cpumask_empty(mask))
 463                                 return -EINVAL;
 464                 }
 465         }
 466
 467         flags = affinity ? IRQD_AFFINITY_MANAGED | IRQD_MANAGED_SHUTDOWN : 0;
 468         mask = NULL;
 469
 470         for (i = 0; i < cnt; i++) {
 471                 if (affinity) {
 472                         node = cpu_to_node(cpumask_first(affinity));
 473                         mask = affinity;
 474                         affinity++;
 475                 }
 476                 desc = alloc_desc(start + i, node, flags, mask, owner);
 477                 if (!desc)
 478                         goto err;
 479                 irq_insert_desc(start + i, desc);
 480                 irq_sysfs_add(start + i, desc);
 481                 irq_add_debugfs_entry(start + i, desc);
 482         }
 483         bitmap_set(allocated_irqs, start, cnt);
 484         return start;
 485
 486 err:
 487         for (i--; i >= 0; i--)
 488                 free_desc(start + i);
 489         return -ENOMEM;
 490 }
 491
 492 static int irq_expand_nr_irqs(unsigned int nr)
 493 {
 494         if (nr > IRQ_BITMAP_BITS)
 495                 return -ENOMEM;
 496         nr_irqs = nr;
 497         return 0;
 498 }
 499
 500 int __init early_irq_init(void)
 501 {
 502         int i, initcnt, node = first_online_node;
 503         struct irq_desc *desc;
 504
 505         init_irq_default_affinity();
 506
 507         /* Let arch update nr_irqs and return the nr of preallocated irqs */
 508         initcnt = arch_probe_nr_irqs();
 509         printk(KERN_INFO "NR_IRQS: %d, nr_irqs: %d, preallocated irqs: %d\n",
 510                NR_IRQS, nr_irqs, initcnt);
 511
 512         if (WARN_ON(nr_irqs > IRQ_BITMAP_BITS))
 513                 nr_irqs = IRQ_BITMAP_BITS;
 514
 515         if (WARN_ON(initcnt > IRQ_BITMAP_BITS))
 516                 initcnt = IRQ_BITMAP_BITS;
 517
 518         if (initcnt > nr_irqs)
 519                 nr_irqs = initcnt;
 520
 521         for (i = 0; i < initcnt; i++) {
 522                 desc = alloc_desc(i, node, 0, NULL, NULL);
 523                 set_bit(i, allocated_irqs);
 524                 irq_insert_desc(i, desc);
 525         }
 526         return arch_early_irq_init();
 527 }
 528
 529 #else /* !CONFIG_SPARSE_IRQ */
 530
 531 struct irq_desc irq_desc[NR_IRQS] __cacheline_aligned_in_smp = {
 532         [0 ... NR_IRQS-1] = {
 533                 .handle_irq     = handle_bad_irq,
 534                 .depth          = 1,
 535                 .lock           = __RAW_SPIN_LOCK_UNLOCKED(irq_desc->lock),
 536         }
 537 };
 538
 539 int __init early_irq_init(void)
 540 {
 541         int count, i, node = first_online_node;
 542         struct irq_desc *desc;
 543
 544         init_irq_default_affinity();
 545
 546         printk(KERN_INFO "NR_IRQS: %d\n", NR_IRQS);
 547
 548         desc = irq_desc;
 549         count = ARRAY_SIZE(irq_desc);
 550
 551         for (i = 0; i < count; i++) {
 552                 desc[i].kstat_irqs = alloc_percpu(unsigned int);
 553                 alloc_masks(&desc[i], node);
 554                 raw_spin_lock_init(&desc[i].lock);
 555                 lockdep_set_class(&desc[i].lock, &irq_desc_lock_class);
 556                 desc_set_defaults(i, &desc[i], node, NULL, NULL);
 557         }
 558         return arch_early_irq_init();
 559 }
 560
 561 struct irq_desc *irq_to_desc(unsigned int irq)
 562 {
 563         return (irq < NR_IRQS) ? irq_desc + irq : NULL;
 564 }
 565 EXPORT_SYMBOL(irq_to_desc);
 566
 567 static void free_desc(unsigned int irq)
 568 {
 569         struct irq_desc *desc = irq_to_desc(irq);
 570         unsigned long flags;
 571
 572         raw_spin_lock_irqsave(&desc->lock, flags);
 573         desc_set_defaults(irq, desc, irq_desc_get_node(desc), NULL, NULL);
 574         raw_spin_unlock_irqrestore(&desc->lock, flags);
 575 }
 576
 577 static inline int alloc_descs(unsigned int start, unsigned int cnt, int node,
 578                               const struct cpumask *affinity,
 579                               struct module *owner)
 580 {
 581         u32 i;
 582
 583         for (i = 0; i < cnt; i++) {
 584                 struct irq_desc *desc = irq_to_desc(start + i);
 585
 586                 desc->owner = owner;
 587         }
 588         bitmap_set(allocated_irqs, start, cnt);
 589         return start;
 590 }
 591
 592 static int irq_expand_nr_irqs(unsigned int nr)
 593 {
 594         return -ENOMEM;
 595 }
 596
 597 void irq_mark_irq(unsigned int irq)
 598 {
 599         mutex_lock(&sparse_irq_lock);
 600         bitmap_set(allocated_irqs, irq, 1);
 601         mutex_unlock(&sparse_irq_lock);
 602 }
 603
 604 #ifdef CONFIG_GENERIC_IRQ_LEGACY
 605 void irq_init_desc(unsigned int irq)
 606 {
 607         free_desc(irq);
 608 }
 609 #endif
 610
 611 #endif /* !CONFIG_SPARSE_IRQ */
 612
 613 /**
 614  * generic_handle_irq - Invoke the handler for a particular irq
 615  * @irq:        The irq number to handle
 616  *
 617  */
 618 int generic_handle_irq(unsigned int irq)
 619 {
 620         struct irq_desc *desc = irq_to_desc(irq);
 621
 622         if (!desc)
 623                 return -EINVAL;
 624         generic_handle_irq_desc(desc);
 625         return 0;
 626 }
 627 EXPORT_SYMBOL_GPL(generic_handle_irq);
 628
 629 #ifdef CONFIG_HANDLE_DOMAIN_IRQ
 630 /**
 631  * __handle_domain_irq - Invoke the handler for a HW irq belonging to a domain
 632  * @domain:     The domain where to perform the lookup
 633  * @hwirq:      The HW irq number to convert to a logical one
 634  * @lookup:     Whether to perform the domain lookup or not
 635  * @regs:       Register file coming from the low-level handling code
 636  *
 637  * Returns:     0 on success, or -EINVAL if conversion has failed
 638  */
 639 int __handle_domain_irq(struct irq_domain *domain, unsigned int hwirq,
 640                         bool lookup, struct pt_regs *regs)
 641 {
 642         struct pt_regs *old_regs = set_irq_regs(regs);
 643         unsigned int irq = hwirq;
 644         int ret = 0;
 645
 646         irq_enter();
 647
 648 #ifdef CONFIG_IRQ_DOMAIN
 649         if (lookup)
 650                 irq = irq_find_mapping(domain, hwirq);
 651 #endif
 652
 653         /*
 654          * Some hardware gives randomly wrong interrupts.  Rather
 655          * than crashing, do something sensible.
 656          */
 657         if (unlikely(!irq || irq >= nr_irqs)) {
 658                 ack_bad_irq(irq);
 659                 ret = -EINVAL;
 660         } else {
 661                 generic_handle_irq(irq);
 662         }
 663
 664         irq_exit();
 665         set_irq_regs(old_regs);
 666         return ret;
 667 }
 668 #endif
 669
 670 /* Dynamic interrupt handling */
 671
 672 /**
 673  * irq_free_descs - free irq descriptors
 674  * @from:       Start of descriptor range
 675  * @cnt:        Number of consecutive irqs to free
 676  */
 677 void irq_free_descs(unsigned int from, unsigned int cnt)
 678 {
 679         int i;
 680
 681         if (from >= nr_irqs || (from + cnt) > nr_irqs)
 682                 return;
 683
 684         mutex_lock(&sparse_irq_lock);
 685         for (i = 0; i < cnt; i++)
 686                 free_desc(from + i);
 687
 688         bitmap_clear(allocated_irqs, from, cnt);
 689         mutex_unlock(&sparse_irq_lock);
 690 }
 691 EXPORT_SYMBOL_GPL(irq_free_descs);
 692
 693 /**
 694  * irq_alloc_descs - allocate and initialize a range of irq descriptors
 695  * @irq:        Allocate for specific irq number if irq >= 0
 696  * @from:       Start the search from this irq number
 697  * @cnt:        Number of consecutive irqs to allocate.
 698  * @node:       Preferred node on which the irq descriptor should be allocated
 699  * @owner:      Owning module (can be NULL)
 700  * @affinity:   Optional pointer to an affinity mask array of size @cnt which
 701  *              hints where the irq descriptors should be allocated and which
 702  *              default affinities to use
 703  *
 704  * Returns the first irq number or error code
 705  */
 706 int __ref
 707 __irq_alloc_descs(int irq, unsigned int from, unsigned int cnt, int node,
 708                   struct module *owner, const struct cpumask *affinity)
 709 {
 710         int start, ret;
 711
 712         if (!cnt)
 713                 return -EINVAL;
 714
 715         if (irq >= 0) {
 716                 if (from > irq)
 717                         return -EINVAL;
 718                 from = irq;
 719         } else {
 720                 /*
 721                  * For interrupts which are freely allocated the
 722                  * architecture can force a lower bound to the @from
 723                  * argument. x86 uses this to exclude the GSI space.
 724                  */
 725                 from = arch_dynirq_lower_bound(from);
 726         }
 727
 728         mutex_lock(&sparse_irq_lock);
 729
 730         start = bitmap_find_next_zero_area(allocated_irqs, IRQ_BITMAP_BITS,
 731                                            from, cnt, 0);
 732         ret = -EEXIST;
 733         if (irq >=0 && start != irq)
 734                 goto unlock;
 735
 736         if (start + cnt > nr_irqs) {
 737                 ret = irq_expand_nr_irqs(start + cnt);
 738                 if (ret)
 739                         goto unlock;
 740         }
 741         ret = alloc_descs(start, cnt, node, affinity, owner);
 742 unlock:
 743         mutex_unlock(&sparse_irq_lock);
 744         return ret;
 745 }
 746 EXPORT_SYMBOL_GPL(__irq_alloc_descs);
 747
 748 #ifdef CONFIG_GENERIC_IRQ_LEGACY_ALLOC_HWIRQ
 749 /**
 750  * irq_alloc_hwirqs - Allocate an irq descriptor and initialize the hardware
 751  * @cnt:        number of interrupts to allocate
 752  * @node:       node on which to allocate
 753  *
 754  * Returns an interrupt number > 0 or 0, if the allocation fails.
 755  */
 756 unsigned int irq_alloc_hwirqs(int cnt, int node)
 757 {
 758         int i, irq = __irq_alloc_descs(-1, 0, cnt, node, NULL, NULL);
 759
 760         if (irq < 0)
 761                 return 0;
 762
 763         for (i = irq; cnt > 0; i++, cnt--) {
 764                 if (arch_setup_hwirq(i, node))
 765                         goto err;
 766                 irq_clear_status_flags(i, _IRQ_NOREQUEST);
 767         }
 768         return irq;
 769
 770 err:
 771         for (i--; i >= irq; i--) {
 772                 irq_set_status_flags(i, _IRQ_NOREQUEST | _IRQ_NOPROBE);
 773                 arch_teardown_hwirq(i);
 774         }
 775         irq_free_descs(irq, cnt);
 776         return 0;
 777 }
 778 EXPORT_SYMBOL_GPL(irq_alloc_hwirqs);
 779
 780 /**
 781  * irq_free_hwirqs - Free irq descriptor and cleanup the hardware
 782  * @from:       Free from irq number
 783  * @cnt:        number of interrupts to free
 784  *
 785  */
 786 void irq_free_hwirqs(unsigned int from, int cnt)
 787 {
 788         int i, j;
 789
 790         for (i = from, j = cnt; j > 0; i++, j--) {
 791                 irq_set_status_flags(i, _IRQ_NOREQUEST | _IRQ_NOPROBE);
 792                 arch_teardown_hwirq(i);
 793         }
 794         irq_free_descs(from, cnt);
 795 }
 796 EXPORT_SYMBOL_GPL(irq_free_hwirqs);
 797 #endif
 798
 799 /**
 800  * irq_get_next_irq - get next allocated irq number
 801  * @offset:     where to start the search
 802  *
 803  * Returns next irq number after offset or nr_irqs if none is found.
 804  */
 805 unsigned int irq_get_next_irq(unsigned int offset)
 806 {
 807         return find_next_bit(allocated_irqs, nr_irqs, offset);
 808 }
 809
 810 struct irq_desc *
 811 __irq_get_desc_lock(unsigned int irq, unsigned long *flags, bool bus,
 812                     unsigned int check)
 813 {
 814         struct irq_desc *desc = irq_to_desc(irq);
 815
 816         if (desc) {
 817                 if (check & _IRQ_DESC_CHECK) {
 818                         if ((check & _IRQ_DESC_PERCPU) &&
 819                             !irq_settings_is_per_cpu_devid(desc))
 820                                 return NULL;
 821
 822                         if (!(check & _IRQ_DESC_PERCPU) &&
 823                             irq_settings_is_per_cpu_devid(desc))
 824                                 return NULL;
 825                 }
 826
 827                 if (bus)
 828                         chip_bus_lock(desc);
 829                 raw_spin_lock_irqsave(&desc->lock, *flags);
 830         }
 831         return desc;
 832 }
 833
 834 void __irq_put_desc_unlock(struct irq_desc *desc, unsigned long flags, bool bus)
 835 {
 836         raw_spin_unlock_irqrestore(&desc->lock, flags);
 837         if (bus)
 838                 chip_bus_sync_unlock(desc);
 839 }
 840
 841 int irq_set_percpu_devid_partition(unsigned int irq,
 842                                    const struct cpumask *affinity)
 843 {
 844         struct irq_desc *desc = irq_to_desc(irq);
 845
 846         if (!desc)
 847                 return -EINVAL;
 848
 849         if (desc->percpu_enabled)
 850                 return -EINVAL;
 851
 852         desc->percpu_enabled = kzalloc(sizeof(*desc->percpu_enabled), GFP_KERNEL);
 853
 854         if (!desc->percpu_enabled)
 855                 return -ENOMEM;
 856
 857         if (affinity)
 858                 desc->percpu_affinity = affinity;
 859         else
 860                 desc->percpu_affinity = cpu_possible_mask;
 861
 862         irq_set_percpu_devid_flags(irq);
 863         return 0;
 864 }
 865
 866 int irq_set_percpu_devid(unsigned int irq)
 867 {
 868         return irq_set_percpu_devid_partition(irq, NULL);
 869 }
 870
 871 int irq_get_percpu_devid_partition(unsigned int irq, struct cpumask *affinity)
 872 {
 873         struct irq_desc *desc = irq_to_desc(irq);
 874
 875         if (!desc || !desc->percpu_enabled)
 876                 return -EINVAL;
 877
 878         if (affinity)
 879                 cpumask_copy(affinity, desc->percpu_affinity);
 880
 881         return 0;
 882 }
 883 EXPORT_SYMBOL_GPL(irq_get_percpu_devid_partition);
 884
 885 void kstat_incr_irq_this_cpu(unsigned int irq)
 886 {
 887         kstat_incr_irqs_this_cpu(irq_to_desc(irq));
 888 }
 889
 890 /**
 891  * kstat_irqs_cpu - Get the statistics for an interrupt on a cpu
 892  * @irq:        The interrupt number
 893  * @cpu:        The cpu number
 894  *
 895  * Returns the sum of interrupt counts on @cpu since boot for
 896  * @irq. The caller must ensure that the interrupt is not removed
 897  * concurrently.
 898  */
 899 unsigned int kstat_irqs_cpu(unsigned int irq, int cpu)
 900 {
 901         struct irq_desc *desc = irq_to_desc(irq);
 902
 903         return desc && desc->kstat_irqs ?
 904                         *per_cpu_ptr(desc->kstat_irqs, cpu) : 0;
 905 }
 906
 907 /**
 908  * kstat_irqs - Get the statistics for an interrupt
 909  * @irq:        The interrupt number
 910  *
 911  * Returns the sum of interrupt counts on all cpus since boot for
 912  * @irq. The caller must ensure that the interrupt is not removed
 913  * concurrently.
 914  */
 915 unsigned int kstat_irqs(unsigned int irq)
 916 {
 917         struct irq_desc *desc = irq_to_desc(irq);
 918         int cpu;
 919         unsigned int sum = 0;
 920
 921         if (!desc || !desc->kstat_irqs)
 922                 return 0;
 923         for_each_possible_cpu(cpu)
 924                 sum += *per_cpu_ptr(desc->kstat_irqs, cpu);
 925         return sum;
 926 }
 927
 928 /**
 929  * kstat_irqs_usr - Get the statistics for an interrupt
 930  * @irq:        The interrupt number
 931  *
 932  * Returns the sum of interrupt counts on all cpus since boot for @irq.
 933  * Contrary to kstat_irqs() this can be called from any context.
 934  * It uses rcu since a concurrent removal of an interrupt descriptor is
 935  * observing an rcu grace period before delayed_free_desc()/irq_kobj_release().
 936  */
 937 unsigned int kstat_irqs_usr(unsigned int irq)
 938 {
 939         unsigned int sum;
 940
 941         rcu_read_lock();
 942         sum = kstat_irqs(irq);
 943         rcu_read_unlock();
 944         return sum;
 945 }