kernel/irq/irqdesc.c

   1 /*
   2  * Copyright (C) 1992, 1998-2006 Linus Torvalds, Ingo Molnar
   3  * Copyright (C) 2005-2006, Thomas Gleixner, Russell King
   4  *
   5  * This file contains the interrupt descriptor management code
   6  *
   7  * Detailed information is available in Documentation/DocBook/genericirq
   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
  19 #include "internals.h"
  20
  21 /*
  22  * lockdep: we want to handle all irq_desc locks as a single lock-class:
  23  */
  24 static struct lock_class_key irq_desc_lock_class;
  25
  26 #if defined(CONFIG_SMP)
  27 static void __init init_irq_default_affinity(void)
  28 {
  29         alloc_cpumask_var(&irq_default_affinity, GFP_NOWAIT);
  30         cpumask_setall(irq_default_affinity);
  31 }
  32 #else
  33 static void __init init_irq_default_affinity(void)
  34 {
  35 }
  36 #endif
  37
  38 #ifdef CONFIG_SMP
  39 static int alloc_masks(struct irq_desc *desc, gfp_t gfp, int node)
  40 {
  41         if (!zalloc_cpumask_var_node(&desc->irq_data.affinity, gfp, node))
  42                 return -ENOMEM;
  43
  44 #ifdef CONFIG_GENERIC_PENDING_IRQ
  45         if (!zalloc_cpumask_var_node(&desc->pending_mask, gfp, node)) {
  46                 free_cpumask_var(desc->irq_data.affinity);
  47                 return -ENOMEM;
  48         }
  49 #endif
  50         return 0;
  51 }
  52
  53 static void desc_smp_init(struct irq_desc *desc, int node)
  54 {
  55         desc->irq_data.node = node;
  56         cpumask_copy(desc->irq_data.affinity, irq_default_affinity);
  57 #ifdef CONFIG_GENERIC_PENDING_IRQ
  58         cpumask_clear(desc->pending_mask);
  59 #endif
  60 }
  61
  62 static inline int desc_node(struct irq_desc *desc)
  63 {
  64         return desc->irq_data.node;
  65 }
  66
  67 #else
  68 static inline int
  69 alloc_masks(struct irq_desc *desc, gfp_t gfp, int node) { return 0; }
  70 static inline void desc_smp_init(struct irq_desc *desc, int node) { }
  71 static inline int desc_node(struct irq_desc *desc) { return 0; }
  72 #endif
  73
  74 static void desc_set_defaults(unsigned int irq, struct irq_desc *desc, int node,
  75                 struct module *owner)
  76 {
  77         int cpu;
  78
  79         desc->irq_data.irq = irq;
  80         desc->irq_data.chip = &no_irq_chip;
  81         desc->irq_data.chip_data = NULL;
  82         desc->irq_data.handler_data = NULL;
  83         desc->irq_data.msi_desc = NULL;
  84         irq_settings_clr_and_set(desc, ~0, _IRQ_DEFAULT_INIT_FLAGS);
  85         irqd_set(&desc->irq_data, IRQD_IRQ_DISABLED);
  86         desc->handle_irq = handle_bad_irq;
  87         desc->depth = 1;
  88         desc->irq_count = 0;
  89         desc->irqs_unhandled = 0;
  90         desc->name = NULL;
  91         desc->owner = owner;
  92         for_each_possible_cpu(cpu)
  93                 *per_cpu_ptr(desc->kstat_irqs, cpu) = 0;
  94         desc_smp_init(desc, node);
  95 }
  96
  97 int nr_irqs = NR_IRQS;
  98 EXPORT_SYMBOL_GPL(nr_irqs);
  99
 100 static DEFINE_MUTEX(sparse_irq_lock);
 101 static DECLARE_BITMAP(allocated_irqs, IRQ_BITMAP_BITS);
 102
 103 #ifdef CONFIG_SPARSE_IRQ
 104
 105 static RADIX_TREE(irq_desc_tree, GFP_KERNEL);
 106
 107 static void irq_insert_desc(unsigned int irq, struct irq_desc *desc)
 108 {
 109         radix_tree_insert(&irq_desc_tree, irq, desc);
 110 }
 111
 112 struct irq_desc *irq_to_desc(unsigned int irq)
 113 {
 114         return radix_tree_lookup(&irq_desc_tree, irq);
 115 }
 116 EXPORT_SYMBOL(irq_to_desc);
 117
 118 static void delete_irq_desc(unsigned int irq)
 119 {
 120         radix_tree_delete(&irq_desc_tree, irq);
 121 }
 122
 123 #ifdef CONFIG_SMP
 124 static void free_masks(struct irq_desc *desc)
 125 {
 126 #ifdef CONFIG_GENERIC_PENDING_IRQ
 127         free_cpumask_var(desc->pending_mask);
 128 #endif
 129         free_cpumask_var(desc->irq_data.affinity);
 130 }
 131 #else
 132 static inline void free_masks(struct irq_desc *desc) { }
 133 #endif
 134
 135 static struct irq_desc *alloc_desc(int irq, int node, struct module *owner)
 136 {
 137         struct irq_desc *desc;
 138         gfp_t gfp = GFP_KERNEL;
 139
 140         desc = kzalloc_node(sizeof(*desc), gfp, node);
 141         if (!desc)
 142                 return NULL;
 143         /* allocate based on nr_cpu_ids */
 144         desc->kstat_irqs = alloc_percpu(unsigned int);
 145         if (!desc->kstat_irqs)
 146                 goto err_desc;
 147
 148         if (alloc_masks(desc, gfp, node))
 149                 goto err_kstat;
 150
 151         raw_spin_lock_init(&desc->lock);
 152         lockdep_set_class(&desc->lock, &irq_desc_lock_class);
 153
 154         desc_set_defaults(irq, desc, node, owner);
 155
 156         return desc;
 157
 158 err_kstat:
 159         free_percpu(desc->kstat_irqs);
 160 err_desc:
 161         kfree(desc);
 162         return NULL;
 163 }
 164
 165 static void free_desc(unsigned int irq)
 166 {
 167         struct irq_desc *desc = irq_to_desc(irq);
 168
 169         unregister_irq_proc(irq, desc);
 170
 171         mutex_lock(&sparse_irq_lock);
 172         delete_irq_desc(irq);
 173         mutex_unlock(&sparse_irq_lock);
 174
 175         free_masks(desc);
 176         free_percpu(desc->kstat_irqs);
 177         kfree(desc);
 178 }
 179
 180 static int alloc_descs(unsigned int start, unsigned int cnt, int node,
 181                        struct module *owner)
 182 {
 183         struct irq_desc *desc;
 184         int i;
 185
 186         for (i = 0; i < cnt; i++) {
 187                 desc = alloc_desc(start + i, node, owner);
 188                 if (!desc)
 189                         goto err;
 190                 mutex_lock(&sparse_irq_lock);
 191                 irq_insert_desc(start + i, desc);
 192                 mutex_unlock(&sparse_irq_lock);
 193         }
 194         return start;
 195
 196 err:
 197         for (i--; i >= 0; i--)
 198                 free_desc(start + i);
 199
 200         mutex_lock(&sparse_irq_lock);
 201         bitmap_clear(allocated_irqs, start, cnt);
 202         mutex_unlock(&sparse_irq_lock);
 203         return -ENOMEM;
 204 }
 205
 206 static int irq_expand_nr_irqs(unsigned int nr)
 207 {
 208         if (nr > IRQ_BITMAP_BITS)
 209                 return -ENOMEM;
 210         nr_irqs = nr;
 211         return 0;
 212 }
 213
 214 int __init early_irq_init(void)
 215 {
 216         int i, initcnt, node = first_online_node;
 217         struct irq_desc *desc;
 218
 219         init_irq_default_affinity();
 220
 221         /* Let arch update nr_irqs and return the nr of preallocated irqs */
 222         initcnt = arch_probe_nr_irqs();
 223         printk(KERN_INFO "NR_IRQS:%d nr_irqs:%d %d\n", NR_IRQS, nr_irqs, initcnt);
 224
 225         if (WARN_ON(nr_irqs > IRQ_BITMAP_BITS))
 226                 nr_irqs = IRQ_BITMAP_BITS;
 227
 228         if (WARN_ON(initcnt > IRQ_BITMAP_BITS))
 229                 initcnt = IRQ_BITMAP_BITS;
 230
 231         if (initcnt > nr_irqs)
 232                 nr_irqs = initcnt;
 233
 234         for (i = 0; i < initcnt; i++) {
 235                 desc = alloc_desc(i, node, NULL);
 236                 set_bit(i, allocated_irqs);
 237                 irq_insert_desc(i, desc);
 238         }
 239         return arch_early_irq_init();
 240 }
 241
 242 #else /* !CONFIG_SPARSE_IRQ */
 243
 244 struct irq_desc irq_desc[NR_IRQS] __cacheline_aligned_in_smp = {
 245         [0 ... NR_IRQS-1] = {
 246                 .handle_irq     = handle_bad_irq,
 247                 .depth          = 1,
 248                 .lock           = __RAW_SPIN_LOCK_UNLOCKED(irq_desc->lock),
 249         }
 250 };
 251
 252 int __init early_irq_init(void)
 253 {
 254         int count, i, node = first_online_node;
 255         struct irq_desc *desc;
 256
 257         init_irq_default_affinity();
 258
 259         printk(KERN_INFO "NR_IRQS:%d\n", NR_IRQS);
 260
 261         desc = irq_desc;
 262         count = ARRAY_SIZE(irq_desc);
 263
 264         for (i = 0; i < count; i++) {
 265                 desc[i].kstat_irqs = alloc_percpu(unsigned int);
 266                 alloc_masks(&desc[i], GFP_KERNEL, node);
 267                 raw_spin_lock_init(&desc[i].lock);
 268                 lockdep_set_class(&desc[i].lock, &irq_desc_lock_class);
 269                 desc_set_defaults(i, &desc[i], node, NULL);
 270         }
 271         return arch_early_irq_init();
 272 }
 273
 274 struct irq_desc *irq_to_desc(unsigned int irq)
 275 {
 276         return (irq < NR_IRQS) ? irq_desc + irq : NULL;
 277 }
 278 EXPORT_SYMBOL(irq_to_desc);
 279
 280 static void free_desc(unsigned int irq)
 281 {
 282         struct irq_desc *desc = irq_to_desc(irq);
 283         unsigned long flags;
 284
 285         raw_spin_lock_irqsave(&desc->lock, flags);
 286         desc_set_defaults(irq, desc, desc_node(desc), NULL);
 287         raw_spin_unlock_irqrestore(&desc->lock, flags);
 288 }
 289
 290 static inline int alloc_descs(unsigned int start, unsigned int cnt, int node,
 291                               struct module *owner)
 292 {
 293         u32 i;
 294
 295         for (i = 0; i < cnt; i++) {
 296                 struct irq_desc *desc = irq_to_desc(start + i);
 297
 298                 desc->owner = owner;
 299         }
 300         return start;
 301 }
 302
 303 static int irq_expand_nr_irqs(unsigned int nr)
 304 {
 305         return -ENOMEM;
 306 }
 307
 308 void irq_mark_irq(unsigned int irq)
 309 {
 310         mutex_lock(&sparse_irq_lock);
 311         bitmap_set(allocated_irqs, irq, 1);
 312         mutex_unlock(&sparse_irq_lock);
 313 }
 314
 315 #ifdef CONFIG_GENERIC_IRQ_LEGACY
 316 void irq_init_desc(unsigned int irq)
 317 {
 318         free_desc(irq);
 319 }
 320 #endif
 321
 322 #endif /* !CONFIG_SPARSE_IRQ */
 323
 324 /**
 325  * generic_handle_irq - Invoke the handler for a particular irq
 326  * @irq:        The irq number to handle
 327  *
 328  */
 329 int generic_handle_irq(unsigned int irq)
 330 {
 331         struct irq_desc *desc = irq_to_desc(irq);
 332
 333         if (!desc)
 334                 return -EINVAL;
 335         generic_handle_irq_desc(irq, desc);
 336         return 0;
 337 }
 338 EXPORT_SYMBOL_GPL(generic_handle_irq);
 339
 340 #ifdef CONFIG_HANDLE_DOMAIN_IRQ
 341 /**
 342  * __handle_domain_irq - Invoke the handler for a HW irq belonging to a domain
 343  * @domain:     The domain where to perform the lookup
 344  * @hwirq:      The HW irq number to convert to a logical one
 345  * @lookup:     Whether to perform the domain lookup or not
 346  * @regs:       Register file coming from the low-level handling code
 347  *
 348  * Returns:     0 on success, or -EINVAL if conversion has failed
 349  */
 350 int __handle_domain_irq(struct irq_domain *domain, unsigned int hwirq,
 351                         bool lookup, struct pt_regs *regs)
 352 {
 353         struct pt_regs *old_regs = set_irq_regs(regs);
 354         unsigned int irq = hwirq;
 355         int ret = 0;
 356
 357         irq_enter();
 358
 359 #ifdef CONFIG_IRQ_DOMAIN
 360         if (lookup)
 361                 irq = irq_find_mapping(domain, hwirq);
 362 #endif
 363
 364         /*
 365          * Some hardware gives randomly wrong interrupts.  Rather
 366          * than crashing, do something sensible.
 367          */
 368         if (unlikely(!irq || irq >= nr_irqs)) {
 369                 ack_bad_irq(irq);
 370                 ret = -EINVAL;
 371         } else {
 372                 generic_handle_irq(irq);
 373         }
 374
 375         irq_exit();
 376         set_irq_regs(old_regs);
 377         return ret;
 378 }
 379 #endif
 380
 381 /* Dynamic interrupt handling */
 382
 383 /**
 384  * irq_free_descs - free irq descriptors
 385  * @from:       Start of descriptor range
 386  * @cnt:        Number of consecutive irqs to free
 387  */
 388 void irq_free_descs(unsigned int from, unsigned int cnt)
 389 {
 390         int i;
 391
 392         if (from >= nr_irqs || (from + cnt) > nr_irqs)
 393                 return;
 394
 395         for (i = 0; i < cnt; i++)
 396                 free_desc(from + i);
 397
 398         mutex_lock(&sparse_irq_lock);
 399         bitmap_clear(allocated_irqs, from, cnt);
 400         mutex_unlock(&sparse_irq_lock);
 401 }
 402 EXPORT_SYMBOL_GPL(irq_free_descs);
 403
 404 /**
 405  * irq_alloc_descs - allocate and initialize a range of irq descriptors
 406  * @irq:        Allocate for specific irq number if irq >= 0
 407  * @from:       Start the search from this irq number
 408  * @cnt:        Number of consecutive irqs to allocate.
 409  * @node:       Preferred node on which the irq descriptor should be allocated
 410  * @owner:      Owning module (can be NULL)
 411  *
 412  * Returns the first irq number or error code
 413  */
 414 int __ref
 415 __irq_alloc_descs(int irq, unsigned int from, unsigned int cnt, int node,
 416                   struct module *owner)
 417 {
 418         int start, ret;
 419
 420         if (!cnt)
 421                 return -EINVAL;
 422
 423         if (irq >= 0) {
 424                 if (from > irq)
 425                         return -EINVAL;
 426                 from = irq;
 427         } else {
 428                 /*
 429                  * For interrupts which are freely allocated the
 430                  * architecture can force a lower bound to the @from
 431                  * argument. x86 uses this to exclude the GSI space.
 432                  */
 433                 from = arch_dynirq_lower_bound(from);
 434         }
 435
 436         mutex_lock(&sparse_irq_lock);
 437
 438         start = bitmap_find_next_zero_area(allocated_irqs, IRQ_BITMAP_BITS,
 439                                            from, cnt, 0);
 440         ret = -EEXIST;
 441         if (irq >=0 && start != irq)
 442                 goto err;
 443
 444         if (start + cnt > nr_irqs) {
 445                 ret = irq_expand_nr_irqs(start + cnt);
 446                 if (ret)
 447                         goto err;
 448         }
 449
 450         bitmap_set(allocated_irqs, start, cnt);
 451         mutex_unlock(&sparse_irq_lock);
 452         return alloc_descs(start, cnt, node, owner);
 453
 454 err:
 455         mutex_unlock(&sparse_irq_lock);
 456         return ret;
 457 }
 458 EXPORT_SYMBOL_GPL(__irq_alloc_descs);
 459
 460 #ifdef CONFIG_GENERIC_IRQ_LEGACY_ALLOC_HWIRQ
 461 /**
 462  * irq_alloc_hwirqs - Allocate an irq descriptor and initialize the hardware
 463  * @cnt:        number of interrupts to allocate
 464  * @node:       node on which to allocate
 465  *
 466  * Returns an interrupt number > 0 or 0, if the allocation fails.
 467  */
 468 unsigned int irq_alloc_hwirqs(int cnt, int node)
 469 {
 470         int i, irq = __irq_alloc_descs(-1, 0, cnt, node, NULL);
 471
 472         if (irq < 0)
 473                 return 0;
 474
 475         for (i = irq; cnt > 0; i++, cnt--) {
 476                 if (arch_setup_hwirq(i, node))
 477                         goto err;
 478                 irq_clear_status_flags(i, _IRQ_NOREQUEST);
 479         }
 480         return irq;
 481
 482 err:
 483         for (i--; i >= irq; i--) {
 484                 irq_set_status_flags(i, _IRQ_NOREQUEST | _IRQ_NOPROBE);
 485                 arch_teardown_hwirq(i);
 486         }
 487         irq_free_descs(irq, cnt);
 488         return 0;
 489 }
 490 EXPORT_SYMBOL_GPL(irq_alloc_hwirqs);
 491
 492 /**
 493  * irq_free_hwirqs - Free irq descriptor and cleanup the hardware
 494  * @from:       Free from irq number
 495  * @cnt:        number of interrupts to free
 496  *
 497  */
 498 void irq_free_hwirqs(unsigned int from, int cnt)
 499 {
 500         int i, j;
 501
 502         for (i = from, j = cnt; j > 0; i++, j--) {
 503                 irq_set_status_flags(i, _IRQ_NOREQUEST | _IRQ_NOPROBE);
 504                 arch_teardown_hwirq(i);
 505         }
 506         irq_free_descs(from, cnt);
 507 }
 508 EXPORT_SYMBOL_GPL(irq_free_hwirqs);
 509 #endif
 510
 511 /**
 512  * irq_get_next_irq - get next allocated irq number
 513  * @offset:     where to start the search
 514  *
 515  * Returns next irq number after offset or nr_irqs if none is found.
 516  */
 517 unsigned int irq_get_next_irq(unsigned int offset)
 518 {
 519         return find_next_bit(allocated_irqs, nr_irqs, offset);
 520 }
 521
 522 struct irq_desc *
 523 __irq_get_desc_lock(unsigned int irq, unsigned long *flags, bool bus,
 524                     unsigned int check)
 525 {
 526         struct irq_desc *desc = irq_to_desc(irq);
 527
 528         if (desc) {
 529                 if (check & _IRQ_DESC_CHECK) {
 530                         if ((check & _IRQ_DESC_PERCPU) &&
 531                             !irq_settings_is_per_cpu_devid(desc))
 532                                 return NULL;
 533
 534                         if (!(check & _IRQ_DESC_PERCPU) &&
 535                             irq_settings_is_per_cpu_devid(desc))
 536                                 return NULL;
 537                 }
 538
 539                 if (bus)
 540                         chip_bus_lock(desc);
 541                 raw_spin_lock_irqsave(&desc->lock, *flags);
 542         }
 543         return desc;
 544 }
 545
 546 void __irq_put_desc_unlock(struct irq_desc *desc, unsigned long flags, bool bus)
 547 {
 548         raw_spin_unlock_irqrestore(&desc->lock, flags);
 549         if (bus)
 550                 chip_bus_sync_unlock(desc);
 551 }
 552
 553 int irq_set_percpu_devid(unsigned int irq)
 554 {
 555         struct irq_desc *desc = irq_to_desc(irq);
 556
 557         if (!desc)
 558                 return -EINVAL;
 559
 560         if (desc->percpu_enabled)
 561                 return -EINVAL;
 562
 563         desc->percpu_enabled = kzalloc(sizeof(*desc->percpu_enabled), GFP_KERNEL);
 564
 565         if (!desc->percpu_enabled)
 566                 return -ENOMEM;
 567
 568         irq_set_percpu_devid_flags(irq);
 569         return 0;
 570 }
 571
 572 void kstat_incr_irq_this_cpu(unsigned int irq)
 573 {
 574         kstat_incr_irqs_this_cpu(irq, irq_to_desc(irq));
 575 }
 576
 577 unsigned int kstat_irqs_cpu(unsigned int irq, int cpu)
 578 {
 579         struct irq_desc *desc = irq_to_desc(irq);
 580
 581         return desc && desc->kstat_irqs ?
 582                         *per_cpu_ptr(desc->kstat_irqs, cpu) : 0;
 583 }
 584
 585 unsigned int kstat_irqs(unsigned int irq)
 586 {
 587         struct irq_desc *desc = irq_to_desc(irq);
 588         int cpu;
 589         int sum = 0;
 590
 591         if (!desc || !desc->kstat_irqs)
 592                 return 0;
 593         for_each_possible_cpu(cpu)
 594                 sum += *per_cpu_ptr(desc->kstat_irqs, cpu);
 595         return sum;
 596 }