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 int __init irq_affinity_setup(char *str)
  27 {
  28         zalloc_cpumask_var(&irq_default_affinity, GFP_NOWAIT);
  29         cpulist_parse(str, irq_default_affinity);
  30         /*
  31          * Set at least the boot cpu. We don't want to end up with
  32          * bugreports caused by random comandline masks
  33          */
  34         cpumask_set_cpu(smp_processor_id(), irq_default_affinity);
  35         return 1;
  36 }
  37 __setup("irqaffinity=", irq_affinity_setup);
  38
  39 static void __init init_irq_default_affinity(void)
  40 {
  41 #ifdef CONFIG_CPUMASK_OFFSTACK
  42         if (!irq_default_affinity)
  43                 zalloc_cpumask_var(&irq_default_affinity, GFP_NOWAIT);
  44 #endif
  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, gfp_t gfp, int node)
  56 {
  57         if (!zalloc_cpumask_var_node(&desc->irq_data.affinity, gfp, node))
  58                 return -ENOMEM;
  59
  60 #ifdef CONFIG_GENERIC_PENDING_IRQ
  61         if (!zalloc_cpumask_var_node(&desc->pending_mask, gfp, node)) {
  62                 free_cpumask_var(desc->irq_data.affinity);
  63                 return -ENOMEM;
  64         }
  65 #endif
  66         return 0;
  67 }
  68
  69 static void desc_smp_init(struct irq_desc *desc, int node)
  70 {
  71         desc->irq_data.node = node;
  72         cpumask_copy(desc->irq_data.affinity, irq_default_affinity);
  73 #ifdef CONFIG_GENERIC_PENDING_IRQ
  74         cpumask_clear(desc->pending_mask);
  75 #endif
  76 }
  77
  78 static inline int desc_node(struct irq_desc *desc)
  79 {
  80         return desc->irq_data.node;
  81 }
  82
  83 #else
  84 static inline int
  85 alloc_masks(struct irq_desc *desc, gfp_t gfp, int node) { return 0; }
  86 static inline void desc_smp_init(struct irq_desc *desc, int node) { }
  87 static inline int desc_node(struct irq_desc *desc) { return 0; }
  88 #endif
  89
  90 static void desc_set_defaults(unsigned int irq, struct irq_desc *desc, int node,
  91                 struct module *owner)
  92 {
  93         int cpu;
  94
  95         desc->irq_data.irq = irq;
  96         desc->irq_data.chip = &no_irq_chip;
  97         desc->irq_data.chip_data = NULL;
  98         desc->irq_data.handler_data = NULL;
  99         desc->irq_data.msi_desc = NULL;
 100         irq_settings_clr_and_set(desc, ~0, _IRQ_DEFAULT_INIT_FLAGS);
 101         irqd_set(&desc->irq_data, IRQD_IRQ_DISABLED);
 102         desc->handle_irq = handle_bad_irq;
 103         desc->depth = 1;
 104         desc->irq_count = 0;
 105         desc->irqs_unhandled = 0;
 106         desc->name = NULL;
 107         desc->owner = owner;
 108         for_each_possible_cpu(cpu)
 109                 *per_cpu_ptr(desc->kstat_irqs, cpu) = 0;
 110         desc_smp_init(desc, node);
 111 }
 112
 113 int nr_irqs = NR_IRQS;
 114 EXPORT_SYMBOL_GPL(nr_irqs);
 115
 116 static DEFINE_MUTEX(sparse_irq_lock);
 117 static DECLARE_BITMAP(allocated_irqs, IRQ_BITMAP_BITS);
 118
 119 #ifdef CONFIG_SPARSE_IRQ
 120
 121 static RADIX_TREE(irq_desc_tree, GFP_KERNEL);
 122
 123 static void irq_insert_desc(unsigned int irq, struct irq_desc *desc)
 124 {
 125         radix_tree_insert(&irq_desc_tree, irq, desc);
 126 }
 127
 128 struct irq_desc *irq_to_desc(unsigned int irq)
 129 {
 130         return radix_tree_lookup(&irq_desc_tree, irq);
 131 }
 132 EXPORT_SYMBOL(irq_to_desc);
 133
 134 static void delete_irq_desc(unsigned int irq)
 135 {
 136         radix_tree_delete(&irq_desc_tree, irq);
 137 }
 138
 139 #ifdef CONFIG_SMP
 140 static void free_masks(struct irq_desc *desc)
 141 {
 142 #ifdef CONFIG_GENERIC_PENDING_IRQ
 143         free_cpumask_var(desc->pending_mask);
 144 #endif
 145         free_cpumask_var(desc->irq_data.affinity);
 146 }
 147 #else
 148 static inline void free_masks(struct irq_desc *desc) { }
 149 #endif
 150
 151 static struct irq_desc *alloc_desc(int irq, int node, struct module *owner)
 152 {
 153         struct irq_desc *desc;
 154         gfp_t gfp = GFP_KERNEL;
 155
 156         desc = kzalloc_node(sizeof(*desc), gfp, node);
 157         if (!desc)
 158                 return NULL;
 159         /* allocate based on nr_cpu_ids */
 160         desc->kstat_irqs = alloc_percpu(unsigned int);
 161         if (!desc->kstat_irqs)
 162                 goto err_desc;
 163
 164         if (alloc_masks(desc, gfp, node))
 165                 goto err_kstat;
 166
 167         raw_spin_lock_init(&desc->lock);
 168         lockdep_set_class(&desc->lock, &irq_desc_lock_class);
 169
 170         desc_set_defaults(irq, desc, node, owner);
 171
 172         return desc;
 173
 174 err_kstat:
 175         free_percpu(desc->kstat_irqs);
 176 err_desc:
 177         kfree(desc);
 178         return NULL;
 179 }
 180
 181 static void free_desc(unsigned int irq)
 182 {
 183         struct irq_desc *desc = irq_to_desc(irq);
 184
 185         unregister_irq_proc(irq, desc);
 186
 187         mutex_lock(&sparse_irq_lock);
 188         delete_irq_desc(irq);
 189         mutex_unlock(&sparse_irq_lock);
 190
 191         free_masks(desc);
 192         free_percpu(desc->kstat_irqs);
 193         kfree(desc);
 194 }
 195
 196 static int alloc_descs(unsigned int start, unsigned int cnt, int node,
 197                        struct module *owner)
 198 {
 199         struct irq_desc *desc;
 200         int i;
 201
 202         for (i = 0; i < cnt; i++) {
 203                 desc = alloc_desc(start + i, node, owner);
 204                 if (!desc)
 205                         goto err;
 206                 mutex_lock(&sparse_irq_lock);
 207                 irq_insert_desc(start + i, desc);
 208                 mutex_unlock(&sparse_irq_lock);
 209         }
 210         return start;
 211
 212 err:
 213         for (i--; i >= 0; i--)
 214                 free_desc(start + i);
 215
 216         mutex_lock(&sparse_irq_lock);
 217         bitmap_clear(allocated_irqs, start, cnt);
 218         mutex_unlock(&sparse_irq_lock);
 219         return -ENOMEM;
 220 }
 221
 222 static int irq_expand_nr_irqs(unsigned int nr)
 223 {
 224         if (nr > IRQ_BITMAP_BITS)
 225                 return -ENOMEM;
 226         nr_irqs = nr;
 227         return 0;
 228 }
 229
 230 int __init early_irq_init(void)
 231 {
 232         int i, initcnt, node = first_online_node;
 233         struct irq_desc *desc;
 234
 235         init_irq_default_affinity();
 236
 237         /* Let arch update nr_irqs and return the nr of preallocated irqs */
 238         initcnt = arch_probe_nr_irqs();
 239         printk(KERN_INFO "NR_IRQS:%d nr_irqs:%d %d\n", NR_IRQS, nr_irqs, initcnt);
 240
 241         if (WARN_ON(nr_irqs > IRQ_BITMAP_BITS))
 242                 nr_irqs = IRQ_BITMAP_BITS;
 243
 244         if (WARN_ON(initcnt > IRQ_BITMAP_BITS))
 245                 initcnt = IRQ_BITMAP_BITS;
 246
 247         if (initcnt > nr_irqs)
 248                 nr_irqs = initcnt;
 249
 250         for (i = 0; i < initcnt; i++) {
 251                 desc = alloc_desc(i, node, NULL);
 252                 set_bit(i, allocated_irqs);
 253                 irq_insert_desc(i, desc);
 254         }
 255         return arch_early_irq_init();
 256 }
 257
 258 #else /* !CONFIG_SPARSE_IRQ */
 259
 260 struct irq_desc irq_desc[NR_IRQS] __cacheline_aligned_in_smp = {
 261         [0 ... NR_IRQS-1] = {
 262                 .handle_irq     = handle_bad_irq,
 263                 .depth          = 1,
 264                 .lock           = __RAW_SPIN_LOCK_UNLOCKED(irq_desc->lock),
 265         }
 266 };
 267
 268 int __init early_irq_init(void)
 269 {
 270         int count, i, node = first_online_node;
 271         struct irq_desc *desc;
 272
 273         init_irq_default_affinity();
 274
 275         printk(KERN_INFO "NR_IRQS:%d\n", NR_IRQS);
 276
 277         desc = irq_desc;
 278         count = ARRAY_SIZE(irq_desc);
 279
 280         for (i = 0; i < count; i++) {
 281                 desc[i].kstat_irqs = alloc_percpu(unsigned int);
 282                 alloc_masks(&desc[i], GFP_KERNEL, node);
 283                 raw_spin_lock_init(&desc[i].lock);
 284                 lockdep_set_class(&desc[i].lock, &irq_desc_lock_class);
 285                 desc_set_defaults(i, &desc[i], node, NULL);
 286         }
 287         return arch_early_irq_init();
 288 }
 289
 290 struct irq_desc *irq_to_desc(unsigned int irq)
 291 {
 292         return (irq < NR_IRQS) ? irq_desc + irq : NULL;
 293 }
 294
 295 static void free_desc(unsigned int irq)
 296 {
 297         dynamic_irq_cleanup(irq);
 298 }
 299
 300 static inline int alloc_descs(unsigned int start, unsigned int cnt, int node,
 301                               struct module *owner)
 302 {
 303         u32 i;
 304
 305         for (i = 0; i < cnt; i++) {
 306                 struct irq_desc *desc = irq_to_desc(start + i);
 307
 308                 desc->owner = owner;
 309         }
 310         return start;
 311 }
 312
 313 static int irq_expand_nr_irqs(unsigned int nr)
 314 {
 315         return -ENOMEM;
 316 }
 317
 318 #endif /* !CONFIG_SPARSE_IRQ */
 319
 320 /**
 321  * generic_handle_irq - Invoke the handler for a particular irq
 322  * @irq:        The irq number to handle
 323  *
 324  */
 325 int generic_handle_irq(unsigned int irq)
 326 {
 327         struct irq_desc *desc = irq_to_desc(irq);
 328
 329         if (!desc)
 330                 return -EINVAL;
 331         generic_handle_irq_desc(irq, desc);
 332         return 0;
 333 }
 334 EXPORT_SYMBOL_GPL(generic_handle_irq);
 335
 336 /* Dynamic interrupt handling */
 337
 338 /**
 339  * irq_free_descs - free irq descriptors
 340  * @from:       Start of descriptor range
 341  * @cnt:        Number of consecutive irqs to free
 342  */
 343 void irq_free_descs(unsigned int from, unsigned int cnt)
 344 {
 345         int i;
 346
 347         if (from >= nr_irqs || (from + cnt) > nr_irqs)
 348                 return;
 349
 350         for (i = 0; i < cnt; i++)
 351                 free_desc(from + i);
 352
 353         mutex_lock(&sparse_irq_lock);
 354         bitmap_clear(allocated_irqs, from, cnt);
 355         mutex_unlock(&sparse_irq_lock);
 356 }
 357 EXPORT_SYMBOL_GPL(irq_free_descs);
 358
 359 /**
 360  * irq_alloc_descs - allocate and initialize a range of irq descriptors
 361  * @irq:        Allocate for specific irq number if irq >= 0
 362  * @from:       Start the search from this irq number
 363  * @cnt:        Number of consecutive irqs to allocate.
 364  * @node:       Preferred node on which the irq descriptor should be allocated
 365  * @owner:      Owning module (can be NULL)
 366  *
 367  * Returns the first irq number or error code
 368  */
 369 int __ref
 370 __irq_alloc_descs(int irq, unsigned int from, unsigned int cnt, int node,
 371                   struct module *owner)
 372 {
 373         int start, ret;
 374
 375         if (!cnt)
 376                 return -EINVAL;
 377
 378         if (irq >= 0) {
 379                 if (from > irq)
 380                         return -EINVAL;
 381                 from = irq;
 382         }
 383
 384         mutex_lock(&sparse_irq_lock);
 385
 386         start = bitmap_find_next_zero_area(allocated_irqs, IRQ_BITMAP_BITS,
 387                                            from, cnt, 0);
 388         ret = -EEXIST;
 389         if (irq >=0 && start != irq)
 390                 goto err;
 391
 392         if (start + cnt > nr_irqs) {
 393                 ret = irq_expand_nr_irqs(start + cnt);
 394                 if (ret)
 395                         goto err;
 396         }
 397
 398         bitmap_set(allocated_irqs, start, cnt);
 399         mutex_unlock(&sparse_irq_lock);
 400         return alloc_descs(start, cnt, node, owner);
 401
 402 err:
 403         mutex_unlock(&sparse_irq_lock);
 404         return ret;
 405 }
 406 EXPORT_SYMBOL_GPL(__irq_alloc_descs);
 407
 408 /**
 409  * irq_reserve_irqs - mark irqs allocated
 410  * @from:       mark from irq number
 411  * @cnt:        number of irqs to mark
 412  *
 413  * Returns 0 on success or an appropriate error code
 414  */
 415 int irq_reserve_irqs(unsigned int from, unsigned int cnt)
 416 {
 417         unsigned int start;
 418         int ret = 0;
 419
 420         if (!cnt || (from + cnt) > nr_irqs)
 421                 return -EINVAL;
 422
 423         mutex_lock(&sparse_irq_lock);
 424         start = bitmap_find_next_zero_area(allocated_irqs, nr_irqs, from, cnt, 0);
 425         if (start == from)
 426                 bitmap_set(allocated_irqs, start, cnt);
 427         else
 428                 ret = -EEXIST;
 429         mutex_unlock(&sparse_irq_lock);
 430         return ret;
 431 }
 432
 433 /**
 434  * irq_get_next_irq - get next allocated irq number
 435  * @offset:     where to start the search
 436  *
 437  * Returns next irq number after offset or nr_irqs if none is found.
 438  */
 439 unsigned int irq_get_next_irq(unsigned int offset)
 440 {
 441         return find_next_bit(allocated_irqs, nr_irqs, offset);
 442 }
 443
 444 struct irq_desc *
 445 __irq_get_desc_lock(unsigned int irq, unsigned long *flags, bool bus,
 446                     unsigned int check)
 447 {
 448         struct irq_desc *desc = irq_to_desc(irq);
 449
 450         if (desc) {
 451                 if (check & _IRQ_DESC_CHECK) {
 452                         if ((check & _IRQ_DESC_PERCPU) &&
 453                             !irq_settings_is_per_cpu_devid(desc))
 454                                 return NULL;
 455
 456                         if (!(check & _IRQ_DESC_PERCPU) &&
 457                             irq_settings_is_per_cpu_devid(desc))
 458                                 return NULL;
 459                 }
 460
 461                 if (bus)
 462                         chip_bus_lock(desc);
 463                 raw_spin_lock_irqsave(&desc->lock, *flags);
 464         }
 465         return desc;
 466 }
 467
 468 void __irq_put_desc_unlock(struct irq_desc *desc, unsigned long flags, bool bus)
 469 {
 470         raw_spin_unlock_irqrestore(&desc->lock, flags);
 471         if (bus)
 472                 chip_bus_sync_unlock(desc);
 473 }
 474
 475 int irq_set_percpu_devid(unsigned int irq)
 476 {
 477         struct irq_desc *desc = irq_to_desc(irq);
 478
 479         if (!desc)
 480                 return -EINVAL;
 481
 482         if (desc->percpu_enabled)
 483                 return -EINVAL;
 484
 485         desc->percpu_enabled = kzalloc(sizeof(*desc->percpu_enabled), GFP_KERNEL);
 486
 487         if (!desc->percpu_enabled)
 488                 return -ENOMEM;
 489
 490         irq_set_percpu_devid_flags(irq);
 491         return 0;
 492 }
 493
 494 /**
 495  * dynamic_irq_cleanup - cleanup a dynamically allocated irq
 496  * @irq:        irq number to initialize
 497  */
 498 void dynamic_irq_cleanup(unsigned int irq)
 499 {
 500         struct irq_desc *desc = irq_to_desc(irq);
 501         unsigned long flags;
 502
 503         raw_spin_lock_irqsave(&desc->lock, flags);
 504         desc_set_defaults(irq, desc, desc_node(desc), NULL);
 505         raw_spin_unlock_irqrestore(&desc->lock, flags);
 506 }
 507
 508 unsigned int kstat_irqs_cpu(unsigned int irq, int cpu)
 509 {
 510         struct irq_desc *desc = irq_to_desc(irq);
 511
 512         return desc && desc->kstat_irqs ?
 513                         *per_cpu_ptr(desc->kstat_irqs, cpu) : 0;
 514 }
 515
 516 unsigned int kstat_irqs(unsigned int irq)
 517 {
 518         struct irq_desc *desc = irq_to_desc(irq);
 519         int cpu;
 520         int sum = 0;
 521
 522         if (!desc || !desc->kstat_irqs)
 523                 return 0;
 524         for_each_possible_cpu(cpu)
 525                 sum += *per_cpu_ptr(desc->kstat_irqs, cpu);
 526         return sum;
 527 }