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