kernel/irq/irqdomain.c

   1 #define pr_fmt(fmt)  "irq: " fmt
   2
   3 #include <linux/debugfs.h>
   4 #include <linux/hardirq.h>
   5 #include <linux/interrupt.h>
   6 #include <linux/irq.h>
   7 #include <linux/irqdesc.h>
   8 #include <linux/irqdomain.h>
   9 #include <linux/module.h>
  10 #include <linux/mutex.h>
  11 #include <linux/of.h>
  12 #include <linux/of_address.h>
  13 #include <linux/topology.h>
  14 #include <linux/seq_file.h>
  15 #include <linux/slab.h>
  16 #include <linux/smp.h>
  17 #include <linux/fs.h>
  18
  19 #define IRQ_DOMAIN_MAP_LEGACY 0 /* driver allocated fixed range of irqs.
  20                                  * ie. legacy 8259, gets irqs 1..15 */
  21 #define IRQ_DOMAIN_MAP_NOMAP 1 /* no fast reverse mapping */
  22 #define IRQ_DOMAIN_MAP_LINEAR 2 /* linear map of interrupts */
  23 #define IRQ_DOMAIN_MAP_TREE 3 /* radix tree */
  24
  25 static LIST_HEAD(irq_domain_list);
  26 static DEFINE_MUTEX(irq_domain_mutex);
  27
  28 static DEFINE_MUTEX(revmap_trees_mutex);
  29 static struct irq_domain *irq_default_domain;
  30
  31 /**
  32  * irq_domain_alloc() - Allocate a new irq_domain data structure
  33  * @of_node: optional device-tree node of the interrupt controller
  34  * @revmap_type: type of reverse mapping to use
  35  * @ops: map/unmap domain callbacks
  36  * @host_data: Controller private data pointer
  37  *
  38  * Allocates and initialize and irq_domain structure.  Caller is expected to
  39  * register allocated irq_domain with irq_domain_register().  Returns pointer
  40  * to IRQ domain, or NULL on failure.
  41  */
  42 static struct irq_domain *irq_domain_alloc(struct device_node *of_node,
  43                                            unsigned int revmap_type,
  44                                            const struct irq_domain_ops *ops,
  45                                            void *host_data)
  46 {
  47         struct irq_domain *domain;
  48
  49         domain = kzalloc_node(sizeof(*domain), GFP_KERNEL,
  50                               of_node_to_nid(of_node));
  51         if (WARN_ON(!domain))
  52                 return NULL;
  53
  54         /* Fill structure */
  55         domain->revmap_type = revmap_type;
  56         domain->ops = ops;
  57         domain->host_data = host_data;
  58         domain->of_node = of_node_get(of_node);
  59
  60         return domain;
  61 }
  62
  63 static void irq_domain_free(struct irq_domain *domain)
  64 {
  65         of_node_put(domain->of_node);
  66         kfree(domain);
  67 }
  68
  69 static void irq_domain_add(struct irq_domain *domain)
  70 {
  71         mutex_lock(&irq_domain_mutex);
  72         list_add(&domain->link, &irq_domain_list);
  73         mutex_unlock(&irq_domain_mutex);
  74         pr_debug("Allocated domain of type %d @0x%p\n",
  75                  domain->revmap_type, domain);
  76 }
  77
  78 /**
  79  * irq_domain_remove() - Remove an irq domain.
  80  * @domain: domain to remove
  81  *
  82  * This routine is used to remove an irq domain. The caller must ensure
  83  * that all mappings within the domain have been disposed of prior to
  84  * use, depending on the revmap type.
  85  */
  86 void irq_domain_remove(struct irq_domain *domain)
  87 {
  88         mutex_lock(&irq_domain_mutex);
  89
  90         switch (domain->revmap_type) {
  91         case IRQ_DOMAIN_MAP_LEGACY:
  92                 /*
  93                  * Legacy domains don't manage their own irq_desc
  94                  * allocations, we expect the caller to handle irq_desc
  95                  * freeing on their own.
  96                  */
  97                 break;
  98         case IRQ_DOMAIN_MAP_TREE:
  99                 /*
 100                  * radix_tree_delete() takes care of destroying the root
 101                  * node when all entries are removed. Shout if there are
 102                  * any mappings left.
 103                  */
 104                 WARN_ON(domain->revmap_data.tree.height);
 105                 break;
 106         case IRQ_DOMAIN_MAP_LINEAR:
 107                 kfree(domain->revmap_data.linear.revmap);
 108                 domain->revmap_data.linear.size = 0;
 109                 break;
 110         case IRQ_DOMAIN_MAP_NOMAP:
 111                 break;
 112         }
 113
 114         list_del(&domain->link);
 115
 116         /*
 117          * If the going away domain is the default one, reset it.
 118          */
 119         if (unlikely(irq_default_domain == domain))
 120                 irq_set_default_host(NULL);
 121
 122         mutex_unlock(&irq_domain_mutex);
 123
 124         pr_debug("Removed domain of type %d @0x%p\n",
 125                  domain->revmap_type, domain);
 126
 127         irq_domain_free(domain);
 128 }
 129 EXPORT_SYMBOL_GPL(irq_domain_remove);
 130
 131 static unsigned int irq_domain_legacy_revmap(struct irq_domain *domain,
 132                                              irq_hw_number_t hwirq)
 133 {
 134         irq_hw_number_t first_hwirq = domain->revmap_data.legacy.first_hwirq;
 135         int size = domain->revmap_data.legacy.size;
 136
 137         if (WARN_ON(hwirq < first_hwirq || hwirq >= first_hwirq + size))
 138                 return 0;
 139         return hwirq - first_hwirq + domain->revmap_data.legacy.first_irq;
 140 }
 141
 142 /**
 143  * irq_domain_add_simple() - Allocate and register a simple irq_domain.
 144  * @of_node: pointer to interrupt controller's device tree node.
 145  * @size: total number of irqs in mapping
 146  * @first_irq: first number of irq block assigned to the domain
 147  * @ops: map/unmap domain callbacks
 148  * @host_data: Controller private data pointer
 149  *
 150  * Allocates a legacy irq_domain if irq_base is positive or a linear
 151  * domain otherwise. For the legacy domain, IRQ descriptors will also
 152  * be allocated.
 153  *
 154  * This is intended to implement the expected behaviour for most
 155  * interrupt controllers which is that a linear mapping should
 156  * normally be used unless the system requires a legacy mapping in
 157  * order to support supplying interrupt numbers during non-DT
 158  * registration of devices.
 159  */
 160 struct irq_domain *irq_domain_add_simple(struct device_node *of_node,
 161                                          unsigned int size,
 162                                          unsigned int first_irq,
 163                                          const struct irq_domain_ops *ops,
 164                                          void *host_data)
 165 {
 166         if (first_irq > 0) {
 167                 int irq_base;
 168
 169                 if (IS_ENABLED(CONFIG_SPARSE_IRQ)) {
 170                         /*
 171                          * Set the descriptor allocator to search for a
 172                          * 1-to-1 mapping, such as irq_alloc_desc_at().
 173                          * Use of_node_to_nid() which is defined to
 174                          * numa_node_id() on platforms that have no custom
 175                          * implementation.
 176                          */
 177                         irq_base = irq_alloc_descs(first_irq, first_irq, size,
 178                                                    of_node_to_nid(of_node));
 179                         if (irq_base < 0) {
 180                                 pr_info("Cannot allocate irq_descs @ IRQ%d, assuming pre-allocated\n",
 181                                         first_irq);
 182                                 irq_base = first_irq;
 183                         }
 184                 } else
 185                         irq_base = first_irq;
 186
 187                 return irq_domain_add_legacy(of_node, size, irq_base, 0,
 188                                              ops, host_data);
 189         }
 190
 191         /* A linear domain is the default */
 192         return irq_domain_add_linear(of_node, size, ops, host_data);
 193 }
 194 EXPORT_SYMBOL_GPL(irq_domain_add_simple);
 195
 196 /**
 197  * irq_domain_add_legacy() - Allocate and register a legacy revmap irq_domain.
 198  * @of_node: pointer to interrupt controller's device tree node.
 199  * @size: total number of irqs in legacy mapping
 200  * @first_irq: first number of irq block assigned to the domain
 201  * @first_hwirq: first hwirq number to use for the translation. Should normally
 202  *               be '0', but a positive integer can be used if the effective
 203  *               hwirqs numbering does not begin at zero.
 204  * @ops: map/unmap domain callbacks
 205  * @host_data: Controller private data pointer
 206  *
 207  * Note: the map() callback will be called before this function returns
 208  * for all legacy interrupts except 0 (which is always the invalid irq for
 209  * a legacy controller).
 210  */
 211 struct irq_domain *irq_domain_add_legacy(struct device_node *of_node,
 212                                          unsigned int size,
 213                                          unsigned int first_irq,
 214                                          irq_hw_number_t first_hwirq,
 215                                          const struct irq_domain_ops *ops,
 216                                          void *host_data)
 217 {
 218         struct irq_domain *domain;
 219         unsigned int i;
 220
 221         domain = irq_domain_alloc(of_node, IRQ_DOMAIN_MAP_LEGACY, ops, host_data);
 222         if (!domain)
 223                 return NULL;
 224
 225         domain->revmap_data.legacy.first_irq = first_irq;
 226         domain->revmap_data.legacy.first_hwirq = first_hwirq;
 227         domain->revmap_data.legacy.size = size;
 228
 229         mutex_lock(&irq_domain_mutex);
 230         /* Verify that all the irqs are available */
 231         for (i = 0; i < size; i++) {
 232                 int irq = first_irq + i;
 233                 struct irq_data *irq_data = irq_get_irq_data(irq);
 234
 235                 if (WARN_ON(!irq_data || irq_data->domain)) {
 236                         mutex_unlock(&irq_domain_mutex);
 237                         irq_domain_free(domain);
 238                         return NULL;
 239                 }
 240         }
 241
 242         /* Claim all of the irqs before registering a legacy domain */
 243         for (i = 0; i < size; i++) {
 244                 struct irq_data *irq_data = irq_get_irq_data(first_irq + i);
 245                 irq_data->hwirq = first_hwirq + i;
 246                 irq_data->domain = domain;
 247         }
 248         mutex_unlock(&irq_domain_mutex);
 249
 250         for (i = 0; i < size; i++) {
 251                 int irq = first_irq + i;
 252                 int hwirq = first_hwirq + i;
 253
 254                 /* IRQ0 gets ignored */
 255                 if (!irq)
 256                         continue;
 257
 258                 /* Legacy flags are left to default at this point,
 259                  * one can then use irq_create_mapping() to
 260                  * explicitly change them
 261                  */
 262                 if (ops->map)
 263                         ops->map(domain, irq, hwirq);
 264
 265                 /* Clear norequest flags */
 266                 irq_clear_status_flags(irq, IRQ_NOREQUEST);
 267         }
 268
 269         irq_domain_add(domain);
 270         return domain;
 271 }
 272 EXPORT_SYMBOL_GPL(irq_domain_add_legacy);
 273
 274 /**
 275  * irq_domain_add_linear() - Allocate and register a linear revmap irq_domain.
 276  * @of_node: pointer to interrupt controller's device tree node.
 277  * @size: Number of interrupts in the domain.
 278  * @ops: map/unmap domain callbacks
 279  * @host_data: Controller private data pointer
 280  */
 281 struct irq_domain *irq_domain_add_linear(struct device_node *of_node,
 282                                          unsigned int size,
 283                                          const struct irq_domain_ops *ops,
 284                                          void *host_data)
 285 {
 286         struct irq_domain *domain;
 287         unsigned int *revmap;
 288
 289         revmap = kzalloc_node(sizeof(*revmap) * size, GFP_KERNEL,
 290                               of_node_to_nid(of_node));
 291         if (WARN_ON(!revmap))
 292                 return NULL;
 293
 294         domain = irq_domain_alloc(of_node, IRQ_DOMAIN_MAP_LINEAR, ops, host_data);
 295         if (!domain) {
 296                 kfree(revmap);
 297                 return NULL;
 298         }
 299         domain->revmap_data.linear.size = size;
 300         domain->revmap_data.linear.revmap = revmap;
 301         irq_domain_add(domain);
 302         return domain;
 303 }
 304 EXPORT_SYMBOL_GPL(irq_domain_add_linear);
 305
 306 struct irq_domain *irq_domain_add_nomap(struct device_node *of_node,
 307                                          unsigned int max_irq,
 308                                          const struct irq_domain_ops *ops,
 309                                          void *host_data)
 310 {
 311         struct irq_domain *domain = irq_domain_alloc(of_node,
 312                                         IRQ_DOMAIN_MAP_NOMAP, ops, host_data);
 313         if (domain) {
 314                 domain->revmap_data.nomap.max_irq = max_irq ? max_irq : ~0;
 315                 irq_domain_add(domain);
 316         }
 317         return domain;
 318 }
 319 EXPORT_SYMBOL_GPL(irq_domain_add_nomap);
 320
 321 /**
 322  * irq_domain_add_tree()
 323  * @of_node: pointer to interrupt controller's device tree node.
 324  * @ops: map/unmap domain callbacks
 325  *
 326  * Note: The radix tree will be allocated later during boot automatically
 327  * (the reverse mapping will use the slow path until that happens).
 328  */
 329 struct irq_domain *irq_domain_add_tree(struct device_node *of_node,
 330                                          const struct irq_domain_ops *ops,
 331                                          void *host_data)
 332 {
 333         struct irq_domain *domain = irq_domain_alloc(of_node,
 334                                         IRQ_DOMAIN_MAP_TREE, ops, host_data);
 335         if (domain) {
 336                 INIT_RADIX_TREE(&domain->revmap_data.tree, GFP_KERNEL);
 337                 irq_domain_add(domain);
 338         }
 339         return domain;
 340 }
 341 EXPORT_SYMBOL_GPL(irq_domain_add_tree);
 342
 343 /**
 344  * irq_find_host() - Locates a domain for a given device node
 345  * @node: device-tree node of the interrupt controller
 346  */
 347 struct irq_domain *irq_find_host(struct device_node *node)
 348 {
 349         struct irq_domain *h, *found = NULL;
 350         int rc;
 351
 352         /* We might want to match the legacy controller last since
 353          * it might potentially be set to match all interrupts in
 354          * the absence of a device node. This isn't a problem so far
 355          * yet though...
 356          */
 357         mutex_lock(&irq_domain_mutex);
 358         list_for_each_entry(h, &irq_domain_list, link) {
 359                 if (h->ops->match)
 360                         rc = h->ops->match(h, node);
 361                 else
 362                         rc = (h->of_node != NULL) && (h->of_node == node);
 363
 364                 if (rc) {
 365                         found = h;
 366                         break;
 367                 }
 368         }
 369         mutex_unlock(&irq_domain_mutex);
 370         return found;
 371 }
 372 EXPORT_SYMBOL_GPL(irq_find_host);
 373
 374 /**
 375  * irq_set_default_host() - Set a "default" irq domain
 376  * @domain: default domain pointer
 377  *
 378  * For convenience, it's possible to set a "default" domain that will be used
 379  * whenever NULL is passed to irq_create_mapping(). It makes life easier for
 380  * platforms that want to manipulate a few hard coded interrupt numbers that
 381  * aren't properly represented in the device-tree.
 382  */
 383 void irq_set_default_host(struct irq_domain *domain)
 384 {
 385         pr_debug("Default domain set to @0x%p\n", domain);
 386
 387         irq_default_domain = domain;
 388 }
 389 EXPORT_SYMBOL_GPL(irq_set_default_host);
 390
 391 static void irq_domain_disassociate_many(struct irq_domain *domain,
 392                                          unsigned int irq_base, int count)
 393 {
 394         /*
 395          * disassociate in reverse order;
 396          * not strictly necessary, but nice for unwinding
 397          */
 398         while (count--) {
 399                 int irq = irq_base + count;
 400                 struct irq_data *irq_data = irq_get_irq_data(irq);
 401                 irq_hw_number_t hwirq = irq_data->hwirq;
 402
 403                 if (WARN_ON(!irq_data || irq_data->domain != domain))
 404                         continue;
 405
 406                 irq_set_status_flags(irq, IRQ_NOREQUEST);
 407
 408                 /* remove chip and handler */
 409                 irq_set_chip_and_handler(irq, NULL, NULL);
 410
 411                 /* Make sure it's completed */
 412                 synchronize_irq(irq);
 413
 414                 /* Tell the PIC about it */
 415                 if (domain->ops->unmap)
 416                         domain->ops->unmap(domain, irq);
 417                 smp_mb();
 418
 419                 irq_data->domain = NULL;
 420                 irq_data->hwirq = 0;
 421
 422                 /* Clear reverse map */
 423                 switch(domain->revmap_type) {
 424                 case IRQ_DOMAIN_MAP_LINEAR:
 425                         if (hwirq < domain->revmap_data.linear.size)
 426                                 domain->revmap_data.linear.revmap[hwirq] = 0;
 427                         break;
 428                 case IRQ_DOMAIN_MAP_TREE:
 429                         mutex_lock(&revmap_trees_mutex);
 430                         radix_tree_delete(&domain->revmap_data.tree, hwirq);
 431                         mutex_unlock(&revmap_trees_mutex);
 432                         break;
 433                 }
 434         }
 435 }
 436
 437 int irq_domain_associate_many(struct irq_domain *domain, unsigned int irq_base,
 438                               irq_hw_number_t hwirq_base, int count)
 439 {
 440         unsigned int virq = irq_base;
 441         irq_hw_number_t hwirq = hwirq_base;
 442         int i, ret;
 443
 444         pr_debug("%s(%s, irqbase=%i, hwbase=%i, count=%i)\n", __func__,
 445                 of_node_full_name(domain->of_node), irq_base, (int)hwirq_base, count);
 446
 447         for (i = 0; i < count; i++) {
 448                 struct irq_data *irq_data = irq_get_irq_data(virq + i);
 449
 450                 if (WARN(!irq_data, "error: irq_desc not allocated; "
 451                          "irq=%i hwirq=0x%x\n", virq + i, (int)hwirq + i))
 452                         return -EINVAL;
 453                 if (WARN(irq_data->domain, "error: irq_desc already associated; "
 454                          "irq=%i hwirq=0x%x\n", virq + i, (int)hwirq + i))
 455                         return -EINVAL;
 456         };
 457
 458         for (i = 0; i < count; i++, virq++, hwirq++) {
 459                 struct irq_data *irq_data = irq_get_irq_data(virq);
 460
 461                 irq_data->hwirq = hwirq;
 462                 irq_data->domain = domain;
 463                 if (domain->ops->map) {
 464                         ret = domain->ops->map(domain, virq, hwirq);
 465                         if (ret != 0) {
 466                                 /*
 467                                  * If map() returns -EPERM, this interrupt is protected
 468                                  * by the firmware or some other service and shall not
 469                                  * be mapped.
 470                                  *
 471                                  * Since on some platforms we blindly try to map everything
 472                                  * we end up with a log full of backtraces.
 473                                  *
 474                                  * So instead, we silently fail on -EPERM, it is the
 475                                  * responsibility of the PIC driver to display a relevant
 476                                  * message if needed.
 477                                  */
 478                                 if (ret != -EPERM) {
 479                                         pr_err("irq-%i==>hwirq-0x%lx mapping failed: %d\n",
 480                                                virq, hwirq, ret);
 481                                         WARN_ON(1);
 482                                 }
 483                                 irq_data->domain = NULL;
 484                                 irq_data->hwirq = 0;
 485                                 goto err_unmap;
 486                         }
 487                 }
 488
 489                 switch (domain->revmap_type) {
 490                 case IRQ_DOMAIN_MAP_LINEAR:
 491                         if (hwirq < domain->revmap_data.linear.size)
 492                                 domain->revmap_data.linear.revmap[hwirq] = virq;
 493                         break;
 494                 case IRQ_DOMAIN_MAP_TREE:
 495                         mutex_lock(&revmap_trees_mutex);
 496                         radix_tree_insert(&domain->revmap_data.tree, hwirq, irq_data);
 497                         mutex_unlock(&revmap_trees_mutex);
 498                         break;
 499                 }
 500
 501                 irq_clear_status_flags(virq, IRQ_NOREQUEST);
 502         }
 503
 504         return 0;
 505
 506  err_unmap:
 507         irq_domain_disassociate_many(domain, irq_base, i);
 508         return -EINVAL;
 509 }
 510 EXPORT_SYMBOL_GPL(irq_domain_associate_many);
 511
 512 /**
 513  * irq_create_direct_mapping() - Allocate an irq for direct mapping
 514  * @domain: domain to allocate the irq for or NULL for default domain
 515  *
 516  * This routine is used for irq controllers which can choose the hardware
 517  * interrupt numbers they generate. In such a case it's simplest to use
 518  * the linux irq as the hardware interrupt number.
 519  */
 520 unsigned int irq_create_direct_mapping(struct irq_domain *domain)
 521 {
 522         unsigned int virq;
 523
 524         if (domain == NULL)
 525                 domain = irq_default_domain;
 526
 527         if (WARN_ON(!domain || domain->revmap_type != IRQ_DOMAIN_MAP_NOMAP))
 528                 return 0;
 529
 530         virq = irq_alloc_desc_from(1, of_node_to_nid(domain->of_node));
 531         if (!virq) {
 532                 pr_debug("create_direct virq allocation failed\n");
 533                 return 0;
 534         }
 535         if (virq >= domain->revmap_data.nomap.max_irq) {
 536                 pr_err("ERROR: no free irqs available below %i maximum\n",
 537                         domain->revmap_data.nomap.max_irq);
 538                 irq_free_desc(virq);
 539                 return 0;
 540         }
 541         pr_debug("create_direct obtained virq %d\n", virq);
 542
 543         if (irq_domain_associate(domain, virq, virq)) {
 544                 irq_free_desc(virq);
 545                 return 0;
 546         }
 547
 548         return virq;
 549 }
 550 EXPORT_SYMBOL_GPL(irq_create_direct_mapping);
 551
 552 /**
 553  * irq_create_mapping() - Map a hardware interrupt into linux irq space
 554  * @domain: domain owning this hardware interrupt or NULL for default domain
 555  * @hwirq: hardware irq number in that domain space
 556  *
 557  * Only one mapping per hardware interrupt is permitted. Returns a linux
 558  * irq number.
 559  * If the sense/trigger is to be specified, set_irq_type() should be called
 560  * on the number returned from that call.
 561  */
 562 unsigned int irq_create_mapping(struct irq_domain *domain,
 563                                 irq_hw_number_t hwirq)
 564 {
 565         unsigned int hint;
 566         int virq;
 567
 568         pr_debug("irq_create_mapping(0x%p, 0x%lx)\n", domain, hwirq);
 569
 570         /* Look for default domain if nececssary */
 571         if (domain == NULL)
 572                 domain = irq_default_domain;
 573         if (domain == NULL) {
 574                 pr_warning("irq_create_mapping called for"
 575                            " NULL domain, hwirq=%lx\n", hwirq);
 576                 WARN_ON(1);
 577                 return 0;
 578         }
 579         pr_debug("-> using domain @%p\n", domain);
 580
 581         /* Check if mapping already exists */
 582         virq = irq_find_mapping(domain, hwirq);
 583         if (virq) {
 584                 pr_debug("-> existing mapping on virq %d\n", virq);
 585                 return virq;
 586         }
 587
 588         /* Get a virtual interrupt number */
 589         if (domain->revmap_type == IRQ_DOMAIN_MAP_LEGACY)
 590                 return irq_domain_legacy_revmap(domain, hwirq);
 591
 592         /* Allocate a virtual interrupt number */
 593         hint = hwirq % nr_irqs;
 594         if (hint == 0)
 595                 hint++;
 596         virq = irq_alloc_desc_from(hint, of_node_to_nid(domain->of_node));
 597         if (virq <= 0)
 598                 virq = irq_alloc_desc_from(1, of_node_to_nid(domain->of_node));
 599         if (virq <= 0) {
 600                 pr_debug("-> virq allocation failed\n");
 601                 return 0;
 602         }
 603
 604         if (irq_domain_associate(domain, virq, hwirq)) {
 605                 irq_free_desc(virq);
 606                 return 0;
 607         }
 608
 609         pr_debug("irq %lu on domain %s mapped to virtual irq %u\n",
 610                 hwirq, of_node_full_name(domain->of_node), virq);
 611
 612         return virq;
 613 }
 614 EXPORT_SYMBOL_GPL(irq_create_mapping);
 615
 616 /**
 617  * irq_create_strict_mappings() - Map a range of hw irqs to fixed linux irqs
 618  * @domain: domain owning the interrupt range
 619  * @irq_base: beginning of linux IRQ range
 620  * @hwirq_base: beginning of hardware IRQ range
 621  * @count: Number of interrupts to map
 622  *
 623  * This routine is used for allocating and mapping a range of hardware
 624  * irqs to linux irqs where the linux irq numbers are at pre-defined
 625  * locations. For use by controllers that already have static mappings
 626  * to insert in to the domain.
 627  *
 628  * Non-linear users can use irq_create_identity_mapping() for IRQ-at-a-time
 629  * domain insertion.
 630  *
 631  * 0 is returned upon success, while any failure to establish a static
 632  * mapping is treated as an error.
 633  */
 634 int irq_create_strict_mappings(struct irq_domain *domain, unsigned int irq_base,
 635                                irq_hw_number_t hwirq_base, int count)
 636 {
 637         int ret;
 638
 639         ret = irq_alloc_descs(irq_base, irq_base, count,
 640                               of_node_to_nid(domain->of_node));
 641         if (unlikely(ret < 0))
 642                 return ret;
 643
 644         ret = irq_domain_associate_many(domain, irq_base, hwirq_base, count);
 645         if (unlikely(ret < 0)) {
 646                 irq_free_descs(irq_base, count);
 647                 return ret;
 648         }
 649
 650         return 0;
 651 }
 652 EXPORT_SYMBOL_GPL(irq_create_strict_mappings);
 653
 654 unsigned int irq_create_of_mapping(struct device_node *controller,
 655                                    const u32 *intspec, unsigned int intsize)
 656 {
 657         struct irq_domain *domain;
 658         irq_hw_number_t hwirq;
 659         unsigned int type = IRQ_TYPE_NONE;
 660         unsigned int virq;
 661
 662         domain = controller ? irq_find_host(controller) : irq_default_domain;
 663         if (!domain) {
 664 #ifdef CONFIG_MIPS
 665                 /*
 666                  * Workaround to avoid breaking interrupt controller drivers
 667                  * that don't yet register an irq_domain.  This is temporary
 668                  * code. ~~~gcl, Feb 24, 2012
 669                  *
 670                  * Scheduled for removal in Linux v3.6.  That should be enough
 671                  * time.
 672                  */
 673                 if (intsize > 0)
 674                         return intspec[0];
 675 #endif
 676                 pr_warning("no irq domain found for %s !\n",
 677                            of_node_full_name(controller));
 678                 return 0;
 679         }
 680
 681         /* If domain has no translation, then we assume interrupt line */
 682         if (domain->ops->xlate == NULL)
 683                 hwirq = intspec[0];
 684         else {
 685                 if (domain->ops->xlate(domain, controller, intspec, intsize,
 686                                      &hwirq, &type))
 687                         return 0;
 688         }
 689
 690         /* Create mapping */
 691         virq = irq_create_mapping(domain, hwirq);
 692         if (!virq)
 693                 return virq;
 694
 695         /* Set type if specified and different than the current one */
 696         if (type != IRQ_TYPE_NONE &&
 697             type != (irqd_get_trigger_type(irq_get_irq_data(virq))))
 698                 irq_set_irq_type(virq, type);
 699         return virq;
 700 }
 701 EXPORT_SYMBOL_GPL(irq_create_of_mapping);
 702
 703 /**
 704  * irq_dispose_mapping() - Unmap an interrupt
 705  * @virq: linux irq number of the interrupt to unmap
 706  */
 707 void irq_dispose_mapping(unsigned int virq)
 708 {
 709         struct irq_data *irq_data = irq_get_irq_data(virq);
 710         struct irq_domain *domain;
 711
 712         if (!virq || !irq_data)
 713                 return;
 714
 715         domain = irq_data->domain;
 716         if (WARN_ON(domain == NULL))
 717                 return;
 718
 719         /* Never unmap legacy interrupts */
 720         if (domain->revmap_type == IRQ_DOMAIN_MAP_LEGACY)
 721                 return;
 722
 723         irq_domain_disassociate_many(domain, virq, 1);
 724         irq_free_desc(virq);
 725 }
 726 EXPORT_SYMBOL_GPL(irq_dispose_mapping);
 727
 728 /**
 729  * irq_find_mapping() - Find a linux irq from an hw irq number.
 730  * @domain: domain owning this hardware interrupt
 731  * @hwirq: hardware irq number in that domain space
 732  */
 733 unsigned int irq_find_mapping(struct irq_domain *domain,
 734                               irq_hw_number_t hwirq)
 735 {
 736         struct irq_data *data;
 737
 738         /* Look for default domain if nececssary */
 739         if (domain == NULL)
 740                 domain = irq_default_domain;
 741         if (domain == NULL)
 742                 return 0;
 743
 744         switch (domain->revmap_type) {
 745         case IRQ_DOMAIN_MAP_LEGACY:
 746                 return irq_domain_legacy_revmap(domain, hwirq);
 747         case IRQ_DOMAIN_MAP_LINEAR:
 748                 return irq_linear_revmap(domain, hwirq);
 749         case IRQ_DOMAIN_MAP_TREE:
 750                 rcu_read_lock();
 751                 data = radix_tree_lookup(&domain->revmap_data.tree, hwirq);
 752                 rcu_read_unlock();
 753                 if (data)
 754                         return data->irq;
 755                 break;
 756         case IRQ_DOMAIN_MAP_NOMAP:
 757                 data = irq_get_irq_data(hwirq);
 758                 if (data && (data->domain == domain) && (data->hwirq == hwirq))
 759                         return hwirq;
 760                 break;
 761         }
 762
 763         return 0;
 764 }
 765 EXPORT_SYMBOL_GPL(irq_find_mapping);
 766
 767 /**
 768  * irq_linear_revmap() - Find a linux irq from a hw irq number.
 769  * @domain: domain owning this hardware interrupt
 770  * @hwirq: hardware irq number in that domain space
 771  *
 772  * This is a fast path that can be called directly by irq controller code to
 773  * save a handful of instructions.
 774  */
 775 unsigned int irq_linear_revmap(struct irq_domain *domain,
 776                                irq_hw_number_t hwirq)
 777 {
 778         BUG_ON(domain->revmap_type != IRQ_DOMAIN_MAP_LINEAR);
 779
 780         /* Check revmap bounds; complain if exceeded */
 781         if (WARN_ON(hwirq >= domain->revmap_data.linear.size))
 782                 return 0;
 783
 784         return domain->revmap_data.linear.revmap[hwirq];
 785 }
 786 EXPORT_SYMBOL_GPL(irq_linear_revmap);
 787
 788 #ifdef CONFIG_IRQ_DOMAIN_DEBUG
 789 static int virq_debug_show(struct seq_file *m, void *private)
 790 {
 791         unsigned long flags;
 792         struct irq_desc *desc;
 793         const char *p;
 794         static const char none[] = "none";
 795         void *data;
 796         int i;
 797
 798         seq_printf(m, "%-5s  %-7s  %-15s  %-*s  %s\n", "irq", "hwirq",
 799                       "chip name", (int)(2 * sizeof(void *) + 2), "chip data",
 800                       "domain name");
 801
 802         for (i = 1; i < nr_irqs; i++) {
 803                 desc = irq_to_desc(i);
 804                 if (!desc)
 805                         continue;
 806
 807                 raw_spin_lock_irqsave(&desc->lock, flags);
 808
 809                 if (desc->action && desc->action->handler) {
 810                         struct irq_chip *chip;
 811
 812                         seq_printf(m, "%5d  ", i);
 813                         seq_printf(m, "0x%05lx  ", desc->irq_data.hwirq);
 814
 815                         chip = irq_desc_get_chip(desc);
 816                         if (chip && chip->name)
 817                                 p = chip->name;
 818                         else
 819                                 p = none;
 820                         seq_printf(m, "%-15s  ", p);
 821
 822                         data = irq_desc_get_chip_data(desc);
 823                         seq_printf(m, data ? "0x%p  " : "  %p  ", data);
 824
 825                         if (desc->irq_data.domain)
 826                                 p = of_node_full_name(desc->irq_data.domain->of_node);
 827                         else
 828                                 p = none;
 829                         seq_printf(m, "%s\n", p);
 830                 }
 831
 832                 raw_spin_unlock_irqrestore(&desc->lock, flags);
 833         }
 834
 835         return 0;
 836 }
 837
 838 static int virq_debug_open(struct inode *inode, struct file *file)
 839 {
 840         return single_open(file, virq_debug_show, inode->i_private);
 841 }
 842
 843 static const struct file_operations virq_debug_fops = {
 844         .open = virq_debug_open,
 845         .read = seq_read,
 846         .llseek = seq_lseek,
 847         .release = single_release,
 848 };
 849
 850 static int __init irq_debugfs_init(void)
 851 {
 852         if (debugfs_create_file("irq_domain_mapping", S_IRUGO, NULL,
 853                                  NULL, &virq_debug_fops) == NULL)
 854                 return -ENOMEM;
 855
 856         return 0;
 857 }
 858 __initcall(irq_debugfs_init);
 859 #endif /* CONFIG_IRQ_DOMAIN_DEBUG */
 860
 861 /**
 862  * irq_domain_xlate_onecell() - Generic xlate for direct one cell bindings
 863  *
 864  * Device Tree IRQ specifier translation function which works with one cell
 865  * bindings where the cell value maps directly to the hwirq number.
 866  */
 867 int irq_domain_xlate_onecell(struct irq_domain *d, struct device_node *ctrlr,
 868                              const u32 *intspec, unsigned int intsize,
 869                              unsigned long *out_hwirq, unsigned int *out_type)
 870 {
 871         if (WARN_ON(intsize < 1))
 872                 return -EINVAL;
 873         *out_hwirq = intspec[0];
 874         *out_type = IRQ_TYPE_NONE;
 875         return 0;
 876 }
 877 EXPORT_SYMBOL_GPL(irq_domain_xlate_onecell);
 878
 879 /**
 880  * irq_domain_xlate_twocell() - Generic xlate for direct two cell bindings
 881  *
 882  * Device Tree IRQ specifier translation function which works with two cell
 883  * bindings where the cell values map directly to the hwirq number
 884  * and linux irq flags.
 885  */
 886 int irq_domain_xlate_twocell(struct irq_domain *d, struct device_node *ctrlr,
 887                         const u32 *intspec, unsigned int intsize,
 888                         irq_hw_number_t *out_hwirq, unsigned int *out_type)
 889 {
 890         if (WARN_ON(intsize < 2))
 891                 return -EINVAL;
 892         *out_hwirq = intspec[0];
 893         *out_type = intspec[1] & IRQ_TYPE_SENSE_MASK;
 894         return 0;
 895 }
 896 EXPORT_SYMBOL_GPL(irq_domain_xlate_twocell);
 897
 898 /**
 899  * irq_domain_xlate_onetwocell() - Generic xlate for one or two cell bindings
 900  *
 901  * Device Tree IRQ specifier translation function which works with either one
 902  * or two cell bindings where the cell values map directly to the hwirq number
 903  * and linux irq flags.
 904  *
 905  * Note: don't use this function unless your interrupt controller explicitly
 906  * supports both one and two cell bindings.  For the majority of controllers
 907  * the _onecell() or _twocell() variants above should be used.
 908  */
 909 int irq_domain_xlate_onetwocell(struct irq_domain *d,
 910                                 struct device_node *ctrlr,
 911                                 const u32 *intspec, unsigned int intsize,
 912                                 unsigned long *out_hwirq, unsigned int *out_type)
 913 {
 914         if (WARN_ON(intsize < 1))
 915                 return -EINVAL;
 916         *out_hwirq = intspec[0];
 917         *out_type = (intsize > 1) ? intspec[1] : IRQ_TYPE_NONE;
 918         return 0;
 919 }
 920 EXPORT_SYMBOL_GPL(irq_domain_xlate_onetwocell);
 921
 922 const struct irq_domain_ops irq_domain_simple_ops = {
 923         .xlate = irq_domain_xlate_onetwocell,
 924 };
 925 EXPORT_SYMBOL_GPL(irq_domain_simple_ops);
 926
 927 #ifdef CONFIG_OF_IRQ
 928 void irq_domain_generate_simple(const struct of_device_id *match,
 929                                 u64 phys_base, unsigned int irq_start)
 930 {
 931         struct device_node *node;
 932         pr_debug("looking for phys_base=%llx, irq_start=%i\n",
 933                 (unsigned long long) phys_base, (int) irq_start);
 934         node = of_find_matching_node_by_address(NULL, match, phys_base);
 935         if (node)
 936                 irq_domain_add_legacy(node, 32, irq_start, 0,
 937                                       &irq_domain_simple_ops, NULL);
 938 }
 939 EXPORT_SYMBOL_GPL(irq_domain_generate_simple);
 940 #endif