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/module.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
 116 static void delete_irq_desc(unsigned int irq)
 117 {
 118         radix_tree_delete(&irq_desc_tree, irq);
 119 }
 120
 121 #ifdef CONFIG_SMP
 122 static 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
 130 static inline void free_masks(struct irq_desc *desc) { }
 131 #endif
 132
 133 static 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
 156 err_kstat:
 157         free_percpu(desc->kstat_irqs);
 158 err_desc:
 159         kfree(desc);
 160         return NULL;
 161 }
 162
 163 static 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
 178 static 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
 194 err:
 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
 204 static 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
 212 int __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
 242 struct 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
 250 int __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
 272 struct irq_desc *irq_to_desc(unsigned int irq)
 273 {
 274         return (irq < NR_IRQS) ? irq_desc + irq : NULL;
 275 }
 276
 277 static void free_desc(unsigned int irq)
 278 {
 279         dynamic_irq_cleanup(irq);
 280 }
 281
 282 static 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
 295 static 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  */
 307 int 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 }
 316 EXPORT_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  */
 325 void 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 }
 339 EXPORT_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  */
 351 int __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
 384 err:
 385         mutex_unlock(&sparse_irq_lock);
 386         return ret;
 387 }
 388 EXPORT_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  */
 397 int 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  */
 421 unsigned int irq_get_next_irq(unsigned int offset)
 422 {
 423         return find_next_bit(allocated_irqs, nr_irqs, offset);
 424 }
 425
 426 struct irq_desc *
 427 __irq_get_desc_lock(unsigned int irq, unsigned long *flags, bool bus)
 428 {
 429         struct irq_desc *desc = irq_to_desc(irq);
 430
 431         if (desc) {
 432                 if (bus)
 433                         chip_bus_lock(desc);
 434                 raw_spin_lock_irqsave(&desc->lock, *flags);
 435         }
 436         return desc;
 437 }
 438
 439 void __irq_put_desc_unlock(struct irq_desc *desc, unsigned long flags, bool bus)
 440 {
 441         raw_spin_unlock_irqrestore(&desc->lock, flags);
 442         if (bus)
 443                 chip_bus_sync_unlock(desc);
 444 }
 445
 446 /**
 447  * dynamic_irq_cleanup - cleanup a dynamically allocated irq
 448  * @irq:        irq number to initialize
 449  */
 450 void dynamic_irq_cleanup(unsigned int irq)
 451 {
 452         struct irq_desc *desc = irq_to_desc(irq);
 453         unsigned long flags;
 454
 455         raw_spin_lock_irqsave(&desc->lock, flags);
 456         desc_set_defaults(irq, desc, desc_node(desc), NULL);
 457         raw_spin_unlock_irqrestore(&desc->lock, flags);
 458 }
 459
 460 unsigned int kstat_irqs_cpu(unsigned int irq, int cpu)
 461 {
 462         struct irq_desc *desc = irq_to_desc(irq);
 463
 464         return desc && desc->kstat_irqs ?
 465                         *per_cpu_ptr(desc->kstat_irqs, cpu) : 0;
 466 }
 467
 468 unsigned int kstat_irqs(unsigned int irq)
 469 {
 470         struct irq_desc *desc = irq_to_desc(irq);
 471         int cpu;
 472         int sum = 0;
 473
 474         if (!desc || !desc->kstat_irqs)
 475                 return 0;
 476         for_each_possible_cpu(cpu)
 477                 sum += *per_cpu_ptr(desc->kstat_irqs, cpu);
 478         return sum;
 479 }