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         struct irq_desc *desc = irq_to_desc(irq);
 282         unsigned long flags;
 283
 284         raw_spin_lock_irqsave(&desc->lock, flags);
 285         desc_set_defaults(irq, desc, desc_node(desc), NULL);
 286         raw_spin_unlock_irqrestore(&desc->lock, flags);
 287 }
 288
 289 static inline int alloc_descs(unsigned int start, unsigned int cnt, int node,
 290                               struct module *owner)
 291 {
 292         u32 i;
 293
 294         for (i = 0; i < cnt; i++) {
 295                 struct irq_desc *desc = irq_to_desc(start + i);
 296
 297                 desc->owner = owner;
 298         }
 299         return start;
 300 }
 301
 302 static int irq_expand_nr_irqs(unsigned int nr)
 303 {
 304         return -ENOMEM;
 305 }
 306
 307 void irq_mark_irq(unsigned int irq)
 308 {
 309         mutex_lock(&sparse_irq_lock);
 310         bitmap_set(allocated_irqs, irq, 1);
 311         mutex_unlock(&sparse_irq_lock);
 312 }
 313
 314 #ifdef CONFIG_GENERIC_IRQ_LEGACY
 315 void irq_init_desc(unsigned int irq)
 316 {
 317         free_desc(irq);
 318 }
 319 #endif
 320
 321 #endif /* !CONFIG_SPARSE_IRQ */
 322
 323 /**
 324  * generic_handle_irq - Invoke the handler for a particular irq
 325  * @irq:        The irq number to handle
 326  *
 327  */
 328 int generic_handle_irq(unsigned int irq)
 329 {
 330         struct irq_desc *desc = irq_to_desc(irq);
 331
 332         if (!desc)
 333                 return -EINVAL;
 334         generic_handle_irq_desc(irq, desc);
 335         return 0;
 336 }
 337 EXPORT_SYMBOL_GPL(generic_handle_irq);
 338
 339 /* Dynamic interrupt handling */
 340
 341 /**
 342  * irq_free_descs - free irq descriptors
 343  * @from:       Start of descriptor range
 344  * @cnt:        Number of consecutive irqs to free
 345  */
 346 void irq_free_descs(unsigned int from, unsigned int cnt)
 347 {
 348         int i;
 349
 350         if (from >= nr_irqs || (from + cnt) > nr_irqs)
 351                 return;
 352
 353         for (i = 0; i < cnt; i++)
 354                 free_desc(from + i);
 355
 356         mutex_lock(&sparse_irq_lock);
 357         bitmap_clear(allocated_irqs, from, cnt);
 358         mutex_unlock(&sparse_irq_lock);
 359 }
 360 EXPORT_SYMBOL_GPL(irq_free_descs);
 361
 362 /**
 363  * irq_alloc_descs - allocate and initialize a range of irq descriptors
 364  * @irq:        Allocate for specific irq number if irq >= 0
 365  * @from:       Start the search from this irq number
 366  * @cnt:        Number of consecutive irqs to allocate.
 367  * @node:       Preferred node on which the irq descriptor should be allocated
 368  * @owner:      Owning module (can be NULL)
 369  *
 370  * Returns the first irq number or error code
 371  */
 372 int __ref
 373 __irq_alloc_descs(int irq, unsigned int from, unsigned int cnt, int node,
 374                   struct module *owner)
 375 {
 376         int start, ret;
 377
 378         if (!cnt)
 379                 return -EINVAL;
 380
 381         if (irq >= 0) {
 382                 if (from > irq)
 383                         return -EINVAL;
 384                 from = irq;
 385         } else {
 386                 /*
 387                  * For interrupts which are freely allocated the
 388                  * architecture can force a lower bound to the @from
 389                  * argument. x86 uses this to exclude the GSI space.
 390                  */
 391                 from = arch_dynirq_lower_bound(from);
 392         }
 393
 394         mutex_lock(&sparse_irq_lock);
 395
 396         start = bitmap_find_next_zero_area(allocated_irqs, IRQ_BITMAP_BITS,
 397                                            from, cnt, 0);
 398         ret = -EEXIST;
 399         if (irq >=0 && start != irq)
 400                 goto err;
 401
 402         if (start + cnt > nr_irqs) {
 403                 ret = irq_expand_nr_irqs(start + cnt);
 404                 if (ret)
 405                         goto err;
 406         }
 407
 408         bitmap_set(allocated_irqs, start, cnt);
 409         mutex_unlock(&sparse_irq_lock);
 410         return alloc_descs(start, cnt, node, owner);
 411
 412 err:
 413         mutex_unlock(&sparse_irq_lock);
 414         return ret;
 415 }
 416 EXPORT_SYMBOL_GPL(__irq_alloc_descs);
 417
 418 #ifdef CONFIG_GENERIC_IRQ_LEGACY_ALLOC_HWIRQ
 419 /**
 420  * irq_alloc_hwirqs - Allocate an irq descriptor and initialize the hardware
 421  * @cnt:        number of interrupts to allocate
 422  * @node:       node on which to allocate
 423  *
 424  * Returns an interrupt number > 0 or 0, if the allocation fails.
 425  */
 426 unsigned int irq_alloc_hwirqs(int cnt, int node)
 427 {
 428         int i, irq = __irq_alloc_descs(-1, 0, cnt, node, NULL);
 429
 430         if (irq < 0)
 431                 return 0;
 432
 433         for (i = irq; cnt > 0; i++, cnt--) {
 434                 if (arch_setup_hwirq(i, node))
 435                         goto err;
 436                 irq_clear_status_flags(i, _IRQ_NOREQUEST);
 437         }
 438         return irq;
 439
 440 err:
 441         for (i--; i >= irq; i--) {
 442                 irq_set_status_flags(i, _IRQ_NOREQUEST | _IRQ_NOPROBE);
 443                 arch_teardown_hwirq(i);
 444         }
 445         irq_free_descs(irq, cnt);
 446         return 0;
 447 }
 448 EXPORT_SYMBOL_GPL(irq_alloc_hwirqs);
 449
 450 /**
 451  * irq_free_hwirqs - Free irq descriptor and cleanup the hardware
 452  * @from:       Free from irq number
 453  * @cnt:        number of interrupts to free
 454  *
 455  */
 456 void irq_free_hwirqs(unsigned int from, int cnt)
 457 {
 458         int i, j;
 459
 460         for (i = from, j = cnt; j > 0; i++, j--) {
 461                 irq_set_status_flags(i, _IRQ_NOREQUEST | _IRQ_NOPROBE);
 462                 arch_teardown_hwirq(i);
 463         }
 464         irq_free_descs(from, cnt);
 465 }
 466 EXPORT_SYMBOL_GPL(irq_free_hwirqs);
 467 #endif
 468
 469 /**
 470  * irq_get_next_irq - get next allocated irq number
 471  * @offset:     where to start the search
 472  *
 473  * Returns next irq number after offset or nr_irqs if none is found.
 474  */
 475 unsigned int irq_get_next_irq(unsigned int offset)
 476 {
 477         return find_next_bit(allocated_irqs, nr_irqs, offset);
 478 }
 479
 480 struct irq_desc *
 481 __irq_get_desc_lock(unsigned int irq, unsigned long *flags, bool bus,
 482                     unsigned int check)
 483 {
 484         struct irq_desc *desc = irq_to_desc(irq);
 485
 486         if (desc) {
 487                 if (check & _IRQ_DESC_CHECK) {
 488                         if ((check & _IRQ_DESC_PERCPU) &&
 489                             !irq_settings_is_per_cpu_devid(desc))
 490                                 return NULL;
 491
 492                         if (!(check & _IRQ_DESC_PERCPU) &&
 493                             irq_settings_is_per_cpu_devid(desc))
 494                                 return NULL;
 495                 }
 496
 497                 if (bus)
 498                         chip_bus_lock(desc);
 499                 raw_spin_lock_irqsave(&desc->lock, *flags);
 500         }
 501         return desc;
 502 }
 503
 504 void __irq_put_desc_unlock(struct irq_desc *desc, unsigned long flags, bool bus)
 505 {
 506         raw_spin_unlock_irqrestore(&desc->lock, flags);
 507         if (bus)
 508                 chip_bus_sync_unlock(desc);
 509 }
 510
 511 int irq_set_percpu_devid(unsigned int irq)
 512 {
 513         struct irq_desc *desc = irq_to_desc(irq);
 514
 515         if (!desc)
 516                 return -EINVAL;
 517
 518         if (desc->percpu_enabled)
 519                 return -EINVAL;
 520
 521         desc->percpu_enabled = kzalloc(sizeof(*desc->percpu_enabled), GFP_KERNEL);
 522
 523         if (!desc->percpu_enabled)
 524                 return -ENOMEM;
 525
 526         irq_set_percpu_devid_flags(irq);
 527         return 0;
 528 }
 529
 530 void kstat_incr_irq_this_cpu(unsigned int irq)
 531 {
 532         kstat_incr_irqs_this_cpu(irq, irq_to_desc(irq));
 533 }
 534
 535 unsigned int kstat_irqs_cpu(unsigned int irq, int cpu)
 536 {
 537         struct irq_desc *desc = irq_to_desc(irq);
 538
 539         return desc && desc->kstat_irqs ?
 540                         *per_cpu_ptr(desc->kstat_irqs, cpu) : 0;
 541 }
 542
 543 unsigned int kstat_irqs(unsigned int irq)
 544 {
 545         struct irq_desc *desc = irq_to_desc(irq);
 546         int cpu;
 547         int sum = 0;
 548
 549         if (!desc || !desc->kstat_irqs)
 550                 return 0;
 551         for_each_possible_cpu(cpu)
 552                 sum += *per_cpu_ptr(desc->kstat_irqs, cpu);
 553         return sum;
 554 }