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
 278 static void free_desc(unsigned int irq)
 279 {
 280         dynamic_irq_cleanup(irq);
 281 }
 282
 283 static inline int alloc_descs(unsigned int start, unsigned int cnt, int node,
 284                               struct module *owner)
 285 {
 286         u32 i;
 287
 288         for (i = 0; i < cnt; i++) {
 289                 struct irq_desc *desc = irq_to_desc(start + i);
 290
 291                 desc->owner = owner;
 292         }
 293         return start;
 294 }
 295
 296 static int irq_expand_nr_irqs(unsigned int nr)
 297 {
 298         return -ENOMEM;
 299 }
 300
 301 #endif /* !CONFIG_SPARSE_IRQ */
 302
 303 /**
 304  * generic_handle_irq - Invoke the handler for a particular irq
 305  * @irq:        The irq number to handle
 306  *
 307  */
 308 int generic_handle_irq(unsigned int irq)
 309 {
 310         struct irq_desc *desc = irq_to_desc(irq);
 311
 312         if (!desc)
 313                 return -EINVAL;
 314         generic_handle_irq_desc(irq, desc);
 315         return 0;
 316 }
 317 EXPORT_SYMBOL_GPL(generic_handle_irq);
 318
 319 /* Dynamic interrupt handling */
 320
 321 /**
 322  * irq_free_descs - free irq descriptors
 323  * @from:       Start of descriptor range
 324  * @cnt:        Number of consecutive irqs to free
 325  */
 326 void irq_free_descs(unsigned int from, unsigned int cnt)
 327 {
 328         int i;
 329
 330         if (from >= nr_irqs || (from + cnt) > nr_irqs)
 331                 return;
 332
 333         for (i = 0; i < cnt; i++)
 334                 free_desc(from + i);
 335
 336         mutex_lock(&sparse_irq_lock);
 337         bitmap_clear(allocated_irqs, from, cnt);
 338         mutex_unlock(&sparse_irq_lock);
 339 }
 340 EXPORT_SYMBOL_GPL(irq_free_descs);
 341
 342 /**
 343  * irq_alloc_descs - allocate and initialize a range of irq descriptors
 344  * @irq:        Allocate for specific irq number if irq >= 0
 345  * @from:       Start the search from this irq number
 346  * @cnt:        Number of consecutive irqs to allocate.
 347  * @node:       Preferred node on which the irq descriptor should be allocated
 348  * @owner:      Owning module (can be NULL)
 349  *
 350  * Returns the first irq number or error code
 351  */
 352 int __ref
 353 __irq_alloc_descs(int irq, unsigned int from, unsigned int cnt, int node,
 354                   struct module *owner)
 355 {
 356         int start, ret;
 357
 358         if (!cnt)
 359                 return -EINVAL;
 360
 361         if (irq >= 0) {
 362                 if (from > irq)
 363                         return -EINVAL;
 364                 from = irq;
 365         }
 366
 367         mutex_lock(&sparse_irq_lock);
 368
 369         start = bitmap_find_next_zero_area(allocated_irqs, IRQ_BITMAP_BITS,
 370                                            from, cnt, 0);
 371         ret = -EEXIST;
 372         if (irq >=0 && start != irq)
 373                 goto err;
 374
 375         if (start + cnt > nr_irqs) {
 376                 ret = irq_expand_nr_irqs(start + cnt);
 377                 if (ret)
 378                         goto err;
 379         }
 380
 381         bitmap_set(allocated_irqs, start, cnt);
 382         mutex_unlock(&sparse_irq_lock);
 383         return alloc_descs(start, cnt, node, owner);
 384
 385 err:
 386         mutex_unlock(&sparse_irq_lock);
 387         return ret;
 388 }
 389 EXPORT_SYMBOL_GPL(__irq_alloc_descs);
 390
 391 /**
 392  * irq_reserve_irqs - mark irqs allocated
 393  * @from:       mark from irq number
 394  * @cnt:        number of irqs to mark
 395  *
 396  * Returns 0 on success or an appropriate error code
 397  */
 398 int irq_reserve_irqs(unsigned int from, unsigned int cnt)
 399 {
 400         unsigned int start;
 401         int ret = 0;
 402
 403         if (!cnt || (from + cnt) > nr_irqs)
 404                 return -EINVAL;
 405
 406         mutex_lock(&sparse_irq_lock);
 407         start = bitmap_find_next_zero_area(allocated_irqs, nr_irqs, from, cnt, 0);
 408         if (start == from)
 409                 bitmap_set(allocated_irqs, start, cnt);
 410         else
 411                 ret = -EEXIST;
 412         mutex_unlock(&sparse_irq_lock);
 413         return ret;
 414 }
 415
 416 /**
 417  * irq_get_next_irq - get next allocated irq number
 418  * @offset:     where to start the search
 419  *
 420  * Returns next irq number after offset or nr_irqs if none is found.
 421  */
 422 unsigned int irq_get_next_irq(unsigned int offset)
 423 {
 424         return find_next_bit(allocated_irqs, nr_irqs, offset);
 425 }
 426
 427 struct irq_desc *
 428 __irq_get_desc_lock(unsigned int irq, unsigned long *flags, bool bus,
 429                     unsigned int check)
 430 {
 431         struct irq_desc *desc = irq_to_desc(irq);
 432
 433         if (desc) {
 434                 if (check & _IRQ_DESC_CHECK) {
 435                         if ((check & _IRQ_DESC_PERCPU) &&
 436                             !irq_settings_is_per_cpu_devid(desc))
 437                                 return NULL;
 438
 439                         if (!(check & _IRQ_DESC_PERCPU) &&
 440                             irq_settings_is_per_cpu_devid(desc))
 441                                 return NULL;
 442                 }
 443
 444                 if (bus)
 445                         chip_bus_lock(desc);
 446                 raw_spin_lock_irqsave(&desc->lock, *flags);
 447         }
 448         return desc;
 449 }
 450
 451 void __irq_put_desc_unlock(struct irq_desc *desc, unsigned long flags, bool bus)
 452 {
 453         raw_spin_unlock_irqrestore(&desc->lock, flags);
 454         if (bus)
 455                 chip_bus_sync_unlock(desc);
 456 }
 457
 458 int irq_set_percpu_devid(unsigned int irq)
 459 {
 460         struct irq_desc *desc = irq_to_desc(irq);
 461
 462         if (!desc)
 463                 return -EINVAL;
 464
 465         if (desc->percpu_enabled)
 466                 return -EINVAL;
 467
 468         desc->percpu_enabled = kzalloc(sizeof(*desc->percpu_enabled), GFP_KERNEL);
 469
 470         if (!desc->percpu_enabled)
 471                 return -ENOMEM;
 472
 473         irq_set_percpu_devid_flags(irq);
 474         return 0;
 475 }
 476
 477 /**
 478  * dynamic_irq_cleanup - cleanup a dynamically allocated irq
 479  * @irq:        irq number to initialize
 480  */
 481 void dynamic_irq_cleanup(unsigned int irq)
 482 {
 483         struct irq_desc *desc = irq_to_desc(irq);
 484         unsigned long flags;
 485
 486         raw_spin_lock_irqsave(&desc->lock, flags);
 487         desc_set_defaults(irq, desc, desc_node(desc), NULL);
 488         raw_spin_unlock_irqrestore(&desc->lock, flags);
 489 }
 490
 491 unsigned int kstat_irqs_cpu(unsigned int irq, int cpu)
 492 {
 493         struct irq_desc *desc = irq_to_desc(irq);
 494
 495         return desc && desc->kstat_irqs ?
 496                         *per_cpu_ptr(desc->kstat_irqs, cpu) : 0;
 497 }
 498
 499 unsigned int kstat_irqs(unsigned int irq)
 500 {
 501         struct irq_desc *desc = irq_to_desc(irq);
 502         int cpu;
 503         int sum = 0;
 504
 505         if (!desc || !desc->kstat_irqs)
 506                 return 0;
 507         for_each_possible_cpu(cpu)
 508                 sum += *per_cpu_ptr(desc->kstat_irqs, cpu);
 509         return sum;
 510 }