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
  18 #include "internals.h"
  19
  20 /*
  21  * lockdep: we want to handle all irq_desc locks as a single lock-class:
  22  */
  23 static struct lock_class_key irq_desc_lock_class;
  24
  25 #if defined(CONFIG_SMP)
  26 static void __init init_irq_default_affinity(void)
  27 {
  28         alloc_cpumask_var(&irq_default_affinity, GFP_NOWAIT);
  29         cpumask_setall(irq_default_affinity);
  30 }
  31 #else
  32 static void __init init_irq_default_affinity(void)
  33 {
  34 }
  35 #endif
  36
  37 #ifdef CONFIG_SMP
  38 static int alloc_masks(struct irq_desc *desc, gfp_t gfp, int node)
  39 {
  40         if (!zalloc_cpumask_var_node(&desc->irq_data.affinity, gfp, node))
  41                 return -ENOMEM;
  42
  43 #ifdef CONFIG_GENERIC_PENDING_IRQ
  44         if (!zalloc_cpumask_var_node(&desc->pending_mask, gfp, node)) {
  45                 free_cpumask_var(desc->irq_data.affinity);
  46                 return -ENOMEM;
  47         }
  48 #endif
  49         return 0;
  50 }
  51
  52 static void desc_smp_init(struct irq_desc *desc, int node)
  53 {
  54         desc->irq_data.node = node;
  55         cpumask_copy(desc->irq_data.affinity, irq_default_affinity);
  56 #ifdef CONFIG_GENERIC_PENDING_IRQ
  57         cpumask_clear(desc->pending_mask);
  58 #endif
  59 }
  60
  61 static inline int desc_node(struct irq_desc *desc)
  62 {
  63         return desc->irq_data.node;
  64 }
  65
  66 #else
  67 static inline int
  68 alloc_masks(struct irq_desc *desc, gfp_t gfp, int node) { return 0; }
  69 static inline void desc_smp_init(struct irq_desc *desc, int node) { }
  70 static inline int desc_node(struct irq_desc *desc) { return 0; }
  71 #endif
  72
  73 static void desc_set_defaults(unsigned int irq, struct irq_desc *desc, int node,
  74                 struct module *owner)
  75 {
  76         int cpu;
  77
  78         desc->irq_data.irq = irq;
  79         desc->irq_data.chip = &no_irq_chip;
  80         desc->irq_data.chip_data = NULL;
  81         desc->irq_data.handler_data = NULL;
  82         desc->irq_data.msi_desc = NULL;
  83         irq_settings_clr_and_set(desc, ~0, _IRQ_DEFAULT_INIT_FLAGS);
  84         irqd_set(&desc->irq_data, IRQD_IRQ_DISABLED);
  85         desc->handle_irq = handle_bad_irq;
  86         desc->depth = 1;
  87         desc->irq_count = 0;
  88         desc->irqs_unhandled = 0;
  89         desc->name = NULL;
  90         desc->owner = owner;
  91         for_each_possible_cpu(cpu)
  92                 *per_cpu_ptr(desc->kstat_irqs, cpu) = 0;
  93         desc_smp_init(desc, node);
  94 }
  95
  96 int nr_irqs = NR_IRQS;
  97 EXPORT_SYMBOL_GPL(nr_irqs);
  98
  99 static DEFINE_MUTEX(sparse_irq_lock);
 100 static DECLARE_BITMAP(allocated_irqs, IRQ_BITMAP_BITS);
 101
 102 #ifdef CONFIG_SPARSE_IRQ
 103
 104 static RADIX_TREE(irq_desc_tree, GFP_KERNEL);
 105
 106 static void irq_insert_desc(unsigned int irq, struct irq_desc *desc)
 107 {
 108         radix_tree_insert(&irq_desc_tree, irq, desc);
 109 }
 110
 111 struct irq_desc *irq_to_desc(unsigned int irq)
 112 {
 113         return radix_tree_lookup(&irq_desc_tree, irq);
 114 }
 115 EXPORT_SYMBOL(irq_to_desc);
 116
 117 static void delete_irq_desc(unsigned int irq)
 118 {
 119         radix_tree_delete(&irq_desc_tree, irq);
 120 }
 121
 122 #ifdef CONFIG_SMP
 123 static void free_masks(struct irq_desc *desc)
 124 {
 125 #ifdef CONFIG_GENERIC_PENDING_IRQ
 126         free_cpumask_var(desc->pending_mask);
 127 #endif
 128         free_cpumask_var(desc->irq_data.affinity);
 129 }
 130 #else
 131 static inline void free_masks(struct irq_desc *desc) { }
 132 #endif
 133
 134 static struct irq_desc *alloc_desc(int irq, int node, struct module *owner)
 135 {
 136         struct irq_desc *desc;
 137         gfp_t gfp = GFP_KERNEL;
 138
 139         desc = kzalloc_node(sizeof(*desc), gfp, node);
 140         if (!desc)
 141                 return NULL;
 142         /* allocate based on nr_cpu_ids */
 143         desc->kstat_irqs = alloc_percpu(unsigned int);
 144         if (!desc->kstat_irqs)
 145                 goto err_desc;
 146
 147         if (alloc_masks(desc, gfp, node))
 148                 goto err_kstat;
 149
 150         raw_spin_lock_init(&desc->lock);
 151         lockdep_set_class(&desc->lock, &irq_desc_lock_class);
 152
 153         desc_set_defaults(irq, desc, node, owner);
 154
 155         return desc;
 156
 157 err_kstat:
 158         free_percpu(desc->kstat_irqs);
 159 err_desc:
 160         kfree(desc);
 161         return NULL;
 162 }
 163
 164 static void free_desc(unsigned int irq)
 165 {
 166         struct irq_desc *desc = irq_to_desc(irq);
 167
 168         unregister_irq_proc(irq, desc);
 169
 170         mutex_lock(&sparse_irq_lock);
 171         delete_irq_desc(irq);
 172         mutex_unlock(&sparse_irq_lock);
 173
 174         free_masks(desc);
 175         free_percpu(desc->kstat_irqs);
 176         kfree(desc);
 177 }
 178
 179 static int alloc_descs(unsigned int start, unsigned int cnt, int node,
 180                        struct module *owner)
 181 {
 182         struct irq_desc *desc;
 183         int i;
 184
 185         for (i = 0; i < cnt; i++) {
 186                 desc = alloc_desc(start + i, node, owner);
 187                 if (!desc)
 188                         goto err;
 189                 mutex_lock(&sparse_irq_lock);
 190                 irq_insert_desc(start + i, desc);
 191                 mutex_unlock(&sparse_irq_lock);
 192         }
 193         return start;
 194
 195 err:
 196         for (i--; i >= 0; i--)
 197                 free_desc(start + i);
 198
 199         mutex_lock(&sparse_irq_lock);
 200         bitmap_clear(allocated_irqs, start, cnt);
 201         mutex_unlock(&sparse_irq_lock);
 202         return -ENOMEM;
 203 }
 204
 205 static int irq_expand_nr_irqs(unsigned int nr)
 206 {
 207         if (nr > IRQ_BITMAP_BITS)
 208                 return -ENOMEM;
 209         nr_irqs = nr;
 210         return 0;
 211 }
 212
 213 int __init early_irq_init(void)
 214 {
 215         int i, initcnt, node = first_online_node;
 216         struct irq_desc *desc;
 217
 218         init_irq_default_affinity();
 219
 220         /* Let arch update nr_irqs and return the nr of preallocated irqs */
 221         initcnt = arch_probe_nr_irqs();
 222         printk(KERN_INFO "NR_IRQS:%d nr_irqs:%d %d\n", NR_IRQS, nr_irqs, initcnt);
 223
 224         if (WARN_ON(nr_irqs > IRQ_BITMAP_BITS))
 225                 nr_irqs = IRQ_BITMAP_BITS;
 226
 227         if (WARN_ON(initcnt > IRQ_BITMAP_BITS))
 228                 initcnt = IRQ_BITMAP_BITS;
 229
 230         if (initcnt > nr_irqs)
 231                 nr_irqs = initcnt;
 232
 233         for (i = 0; i < initcnt; i++) {
 234                 desc = alloc_desc(i, node, NULL);
 235                 set_bit(i, allocated_irqs);
 236                 irq_insert_desc(i, desc);
 237         }
 238         return arch_early_irq_init();
 239 }
 240
 241 #else /* !CONFIG_SPARSE_IRQ */
 242
 243 struct irq_desc irq_desc[NR_IRQS] __cacheline_aligned_in_smp = {
 244         [0 ... NR_IRQS-1] = {
 245                 .handle_irq     = handle_bad_irq,
 246                 .depth          = 1,
 247                 .lock           = __RAW_SPIN_LOCK_UNLOCKED(irq_desc->lock),
 248         }
 249 };
 250
 251 int __init early_irq_init(void)
 252 {
 253         int count, i, node = first_online_node;
 254         struct irq_desc *desc;
 255
 256         init_irq_default_affinity();
 257
 258         printk(KERN_INFO "NR_IRQS:%d\n", NR_IRQS);
 259
 260         desc = irq_desc;
 261         count = ARRAY_SIZE(irq_desc);
 262
 263         for (i = 0; i < count; i++) {
 264                 desc[i].kstat_irqs = alloc_percpu(unsigned int);
 265                 alloc_masks(&desc[i], GFP_KERNEL, node);
 266                 raw_spin_lock_init(&desc[i].lock);
 267                 lockdep_set_class(&desc[i].lock, &irq_desc_lock_class);
 268                 desc_set_defaults(i, &desc[i], node, NULL);
 269         }
 270         return arch_early_irq_init();
 271 }
 272
 273 struct irq_desc *irq_to_desc(unsigned int irq)
 274 {
 275         return (irq < NR_IRQS) ? irq_desc + irq : NULL;
 276 }
 277 EXPORT_SYMBOL(irq_to_desc);
 278
 279 static void free_desc(unsigned int irq)
 280 {
 281         dynamic_irq_cleanup(irq);
 282 }
 283
 284 static inline int alloc_descs(unsigned int start, unsigned int cnt, int node,
 285                               struct module *owner)
 286 {
 287         u32 i;
 288
 289         for (i = 0; i < cnt; i++) {
 290                 struct irq_desc *desc = irq_to_desc(start + i);
 291
 292                 desc->owner = owner;
 293         }
 294         return start;
 295 }
 296
 297 static int irq_expand_nr_irqs(unsigned int nr)
 298 {
 299         return -ENOMEM;
 300 }
 301
 302 #endif /* !CONFIG_SPARSE_IRQ */
 303
 304 /**
 305  * generic_handle_irq - Invoke the handler for a particular irq
 306  * @irq:        The irq number to handle
 307  *
 308  */
 309 int generic_handle_irq(unsigned int irq)
 310 {
 311         struct irq_desc *desc = irq_to_desc(irq);
 312
 313         if (!desc)
 314                 return -EINVAL;
 315         generic_handle_irq_desc(irq, desc);
 316         return 0;
 317 }
 318 EXPORT_SYMBOL_GPL(generic_handle_irq);
 319
 320 /* Dynamic interrupt handling */
 321
 322 /**
 323  * irq_free_descs - free irq descriptors
 324  * @from:       Start of descriptor range
 325  * @cnt:        Number of consecutive irqs to free
 326  */
 327 void irq_free_descs(unsigned int from, unsigned int cnt)
 328 {
 329         int i;
 330
 331         if (from >= nr_irqs || (from + cnt) > nr_irqs)
 332                 return;
 333
 334         for (i = 0; i < cnt; i++)
 335                 free_desc(from + i);
 336
 337         mutex_lock(&sparse_irq_lock);
 338         bitmap_clear(allocated_irqs, from, cnt);
 339         mutex_unlock(&sparse_irq_lock);
 340 }
 341 EXPORT_SYMBOL_GPL(irq_free_descs);
 342
 343 /**
 344  * irq_alloc_descs - allocate and initialize a range of irq descriptors
 345  * @irq:        Allocate for specific irq number if irq >= 0
 346  * @from:       Start the search from this irq number
 347  * @cnt:        Number of consecutive irqs to allocate.
 348  * @node:       Preferred node on which the irq descriptor should be allocated
 349  * @owner:      Owning module (can be NULL)
 350  *
 351  * Returns the first irq number or error code
 352  */
 353 int __ref
 354 __irq_alloc_descs(int irq, unsigned int from, unsigned int cnt, int node,
 355                   struct module *owner)
 356 {
 357         int start, ret;
 358
 359         if (!cnt)
 360                 return -EINVAL;
 361
 362         if (irq >= 0) {
 363                 if (from > irq)
 364                         return -EINVAL;
 365                 from = irq;
 366         }
 367
 368         mutex_lock(&sparse_irq_lock);
 369
 370         start = bitmap_find_next_zero_area(allocated_irqs, IRQ_BITMAP_BITS,
 371                                            from, cnt, 0);
 372         ret = -EEXIST;
 373         if (irq >=0 && start != irq)
 374                 goto err;
 375
 376         if (start + cnt > nr_irqs) {
 377                 ret = irq_expand_nr_irqs(start + cnt);
 378                 if (ret)
 379                         goto err;
 380         }
 381
 382         bitmap_set(allocated_irqs, start, cnt);
 383         mutex_unlock(&sparse_irq_lock);
 384         return alloc_descs(start, cnt, node, owner);
 385
 386 err:
 387         mutex_unlock(&sparse_irq_lock);
 388         return ret;
 389 }
 390 EXPORT_SYMBOL_GPL(__irq_alloc_descs);
 391
 392 /**
 393  * irq_reserve_irqs - mark irqs allocated
 394  * @from:       mark from irq number
 395  * @cnt:        number of irqs to mark
 396  *
 397  * Returns 0 on success or an appropriate error code
 398  */
 399 int irq_reserve_irqs(unsigned int from, unsigned int cnt)
 400 {
 401         unsigned int start;
 402         int ret = 0;
 403
 404         if (!cnt || (from + cnt) > nr_irqs)
 405                 return -EINVAL;
 406
 407         mutex_lock(&sparse_irq_lock);
 408         start = bitmap_find_next_zero_area(allocated_irqs, nr_irqs, from, cnt, 0);
 409         if (start == from)
 410                 bitmap_set(allocated_irqs, start, cnt);
 411         else
 412                 ret = -EEXIST;
 413         mutex_unlock(&sparse_irq_lock);
 414         return ret;
 415 }
 416
 417 /**
 418  * irq_get_next_irq - get next allocated irq number
 419  * @offset:     where to start the search
 420  *
 421  * Returns next irq number after offset or nr_irqs if none is found.
 422  */
 423 unsigned int irq_get_next_irq(unsigned int offset)
 424 {
 425         return find_next_bit(allocated_irqs, nr_irqs, offset);
 426 }
 427
 428 struct irq_desc *
 429 __irq_get_desc_lock(unsigned int irq, unsigned long *flags, bool bus,
 430                     unsigned int check)
 431 {
 432         struct irq_desc *desc = irq_to_desc(irq);
 433
 434         if (desc) {
 435                 if (check & _IRQ_DESC_CHECK) {
 436                         if ((check & _IRQ_DESC_PERCPU) &&
 437                             !irq_settings_is_per_cpu_devid(desc))
 438                                 return NULL;
 439
 440                         if (!(check & _IRQ_DESC_PERCPU) &&
 441                             irq_settings_is_per_cpu_devid(desc))
 442                                 return NULL;
 443                 }
 444
 445                 if (bus)
 446                         chip_bus_lock(desc);
 447                 raw_spin_lock_irqsave(&desc->lock, *flags);
 448         }
 449         return desc;
 450 }
 451
 452 void __irq_put_desc_unlock(struct irq_desc *desc, unsigned long flags, bool bus)
 453 {
 454         raw_spin_unlock_irqrestore(&desc->lock, flags);
 455         if (bus)
 456                 chip_bus_sync_unlock(desc);
 457 }
 458
 459 int irq_set_percpu_devid(unsigned int irq)
 460 {
 461         struct irq_desc *desc = irq_to_desc(irq);
 462
 463         if (!desc)
 464                 return -EINVAL;
 465
 466         if (desc->percpu_enabled)
 467                 return -EINVAL;
 468
 469         desc->percpu_enabled = kzalloc(sizeof(*desc->percpu_enabled), GFP_KERNEL);
 470
 471         if (!desc->percpu_enabled)
 472                 return -ENOMEM;
 473
 474         irq_set_percpu_devid_flags(irq);
 475         return 0;
 476 }
 477
 478 /**
 479  * dynamic_irq_cleanup - cleanup a dynamically allocated irq
 480  * @irq:        irq number to initialize
 481  */
 482 void dynamic_irq_cleanup(unsigned int irq)
 483 {
 484         struct irq_desc *desc = irq_to_desc(irq);
 485         unsigned long flags;
 486
 487         raw_spin_lock_irqsave(&desc->lock, flags);
 488         desc_set_defaults(irq, desc, desc_node(desc), NULL);
 489         raw_spin_unlock_irqrestore(&desc->lock, flags);
 490 }
 491
 492 void kstat_incr_irq_this_cpu(unsigned int irq)
 493 {
 494         kstat_incr_irqs_this_cpu(irq, irq_to_desc(irq));
 495 }
 496
 497 unsigned int kstat_irqs_cpu(unsigned int irq, int cpu)
 498 {
 499         struct irq_desc *desc = irq_to_desc(irq);
 500
 501         return desc && desc->kstat_irqs ?
 502                         *per_cpu_ptr(desc->kstat_irqs, cpu) : 0;
 503 }
 504
 505 unsigned int kstat_irqs(unsigned int irq)
 506 {
 507         struct irq_desc *desc = irq_to_desc(irq);
 508         int cpu;
 509         int sum = 0;
 510
 511         if (!desc || !desc->kstat_irqs)
 512                 return 0;
 513         for_each_possible_cpu(cpu)
 514                 sum += *per_cpu_ptr(desc->kstat_irqs, cpu);
 515         return sum;
 516 }