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 extern struct cpumask hmp_slow_cpu_mask;
  40
  41 static void __init init_irq_default_affinity(void)
  42 {
  43 #ifdef CONFIG_CPUMASK_OFFSTACK
  44         if (!irq_default_affinity)
  45                 zalloc_cpumask_var(&irq_default_affinity, GFP_NOWAIT);
  46 #endif
  47 #ifdef CONFIG_SCHED_HMP
  48         if (!cpumask_empty(&hmp_slow_cpu_mask)) {
  49                 cpumask_copy(irq_default_affinity, &hmp_slow_cpu_mask);
  50                 return;
  51         }
  52 #endif
  53         if (cpumask_empty(irq_default_affinity))
  54                 cpumask_setall(irq_default_affinity);
  55 }
  56 #else
  57 static void __init init_irq_default_affinity(void)
  58 {
  59 }
  60 #endif
  61
  62 #ifdef CONFIG_SMP
  63 static int alloc_masks(struct irq_desc *desc, gfp_t gfp, int node)
  64 {
  65         if (!zalloc_cpumask_var_node(&desc->irq_data.affinity, gfp, node))
  66                 return -ENOMEM;
  67
  68 #ifdef CONFIG_GENERIC_PENDING_IRQ
  69         if (!zalloc_cpumask_var_node(&desc->pending_mask, gfp, node)) {
  70                 free_cpumask_var(desc->irq_data.affinity);
  71                 return -ENOMEM;
  72         }
  73 #endif
  74         return 0;
  75 }
  76
  77 static void desc_smp_init(struct irq_desc *desc, int node)
  78 {
  79         desc->irq_data.node = node;
  80         cpumask_copy(desc->irq_data.affinity, irq_default_affinity);
  81 #ifdef CONFIG_GENERIC_PENDING_IRQ
  82         cpumask_clear(desc->pending_mask);
  83 #endif
  84 }
  85
  86 static inline int desc_node(struct irq_desc *desc)
  87 {
  88         return desc->irq_data.node;
  89 }
  90
  91 #else
  92 static inline int
  93 alloc_masks(struct irq_desc *desc, gfp_t gfp, int node) { return 0; }
  94 static inline void desc_smp_init(struct irq_desc *desc, int node) { }
  95 static inline int desc_node(struct irq_desc *desc) { return 0; }
  96 #endif
  97
  98 static void desc_set_defaults(unsigned int irq, struct irq_desc *desc, int node,
  99                 struct module *owner)
 100 {
 101         int cpu;
 102
 103         desc->irq_data.irq = irq;
 104         desc->irq_data.chip = &no_irq_chip;
 105         desc->irq_data.chip_data = NULL;
 106         desc->irq_data.handler_data = NULL;
 107         desc->irq_data.msi_desc = NULL;
 108         irq_settings_clr_and_set(desc, ~0, _IRQ_DEFAULT_INIT_FLAGS);
 109         irqd_set(&desc->irq_data, IRQD_IRQ_DISABLED);
 110         desc->handle_irq = handle_bad_irq;
 111         desc->depth = 1;
 112         desc->irq_count = 0;
 113         desc->irqs_unhandled = 0;
 114         desc->name = NULL;
 115         desc->owner = owner;
 116         for_each_possible_cpu(cpu)
 117                 *per_cpu_ptr(desc->kstat_irqs, cpu) = 0;
 118         desc_smp_init(desc, node);
 119 }
 120
 121 int nr_irqs = NR_IRQS;
 122 EXPORT_SYMBOL_GPL(nr_irqs);
 123
 124 static DEFINE_MUTEX(sparse_irq_lock);
 125 static DECLARE_BITMAP(allocated_irqs, IRQ_BITMAP_BITS);
 126
 127 #ifdef CONFIG_SPARSE_IRQ
 128
 129 static RADIX_TREE(irq_desc_tree, GFP_KERNEL);
 130
 131 static void irq_insert_desc(unsigned int irq, struct irq_desc *desc)
 132 {
 133         radix_tree_insert(&irq_desc_tree, irq, desc);
 134 }
 135
 136 struct irq_desc *irq_to_desc(unsigned int irq)
 137 {
 138         return radix_tree_lookup(&irq_desc_tree, irq);
 139 }
 140 EXPORT_SYMBOL(irq_to_desc);
 141
 142 static void delete_irq_desc(unsigned int irq)
 143 {
 144         radix_tree_delete(&irq_desc_tree, irq);
 145 }
 146
 147 #ifdef CONFIG_SMP
 148 static void free_masks(struct irq_desc *desc)
 149 {
 150 #ifdef CONFIG_GENERIC_PENDING_IRQ
 151         free_cpumask_var(desc->pending_mask);
 152 #endif
 153         free_cpumask_var(desc->irq_data.affinity);
 154 }
 155 #else
 156 static inline void free_masks(struct irq_desc *desc) { }
 157 #endif
 158
 159 static struct irq_desc *alloc_desc(int irq, int node, struct module *owner)
 160 {
 161         struct irq_desc *desc;
 162         gfp_t gfp = GFP_KERNEL;
 163
 164         desc = kzalloc_node(sizeof(*desc), gfp, node);
 165         if (!desc)
 166                 return NULL;
 167         /* allocate based on nr_cpu_ids */
 168         desc->kstat_irqs = alloc_percpu(unsigned int);
 169         if (!desc->kstat_irqs)
 170                 goto err_desc;
 171
 172         if (alloc_masks(desc, gfp, node))
 173                 goto err_kstat;
 174
 175         raw_spin_lock_init(&desc->lock);
 176         lockdep_set_class(&desc->lock, &irq_desc_lock_class);
 177
 178         desc_set_defaults(irq, desc, node, owner);
 179
 180         return desc;
 181
 182 err_kstat:
 183         free_percpu(desc->kstat_irqs);
 184 err_desc:
 185         kfree(desc);
 186         return NULL;
 187 }
 188
 189 static void free_desc(unsigned int irq)
 190 {
 191         struct irq_desc *desc = irq_to_desc(irq);
 192
 193         unregister_irq_proc(irq, desc);
 194
 195         mutex_lock(&sparse_irq_lock);
 196         delete_irq_desc(irq);
 197         mutex_unlock(&sparse_irq_lock);
 198
 199         free_masks(desc);
 200         free_percpu(desc->kstat_irqs);
 201         kfree(desc);
 202 }
 203
 204 static int alloc_descs(unsigned int start, unsigned int cnt, int node,
 205                        struct module *owner)
 206 {
 207         struct irq_desc *desc;
 208         int i;
 209
 210         for (i = 0; i < cnt; i++) {
 211                 desc = alloc_desc(start + i, node, owner);
 212                 if (!desc)
 213                         goto err;
 214                 mutex_lock(&sparse_irq_lock);
 215                 irq_insert_desc(start + i, desc);
 216                 mutex_unlock(&sparse_irq_lock);
 217         }
 218         return start;
 219
 220 err:
 221         for (i--; i >= 0; i--)
 222                 free_desc(start + i);
 223
 224         mutex_lock(&sparse_irq_lock);
 225         bitmap_clear(allocated_irqs, start, cnt);
 226         mutex_unlock(&sparse_irq_lock);
 227         return -ENOMEM;
 228 }
 229
 230 static int irq_expand_nr_irqs(unsigned int nr)
 231 {
 232         if (nr > IRQ_BITMAP_BITS)
 233                 return -ENOMEM;
 234         nr_irqs = nr;
 235         return 0;
 236 }
 237
 238 int __init early_irq_init(void)
 239 {
 240         int i, initcnt, node = first_online_node;
 241         struct irq_desc *desc;
 242
 243         init_irq_default_affinity();
 244
 245         /* Let arch update nr_irqs and return the nr of preallocated irqs */
 246         initcnt = arch_probe_nr_irqs();
 247         printk(KERN_INFO "NR_IRQS:%d nr_irqs:%d %d\n", NR_IRQS, nr_irqs, initcnt);
 248
 249         if (WARN_ON(nr_irqs > IRQ_BITMAP_BITS))
 250                 nr_irqs = IRQ_BITMAP_BITS;
 251
 252         if (WARN_ON(initcnt > IRQ_BITMAP_BITS))
 253                 initcnt = IRQ_BITMAP_BITS;
 254
 255         if (initcnt > nr_irqs)
 256                 nr_irqs = initcnt;
 257
 258         for (i = 0; i < initcnt; i++) {
 259                 desc = alloc_desc(i, node, NULL);
 260                 set_bit(i, allocated_irqs);
 261                 irq_insert_desc(i, desc);
 262         }
 263         return arch_early_irq_init();
 264 }
 265
 266 #else /* !CONFIG_SPARSE_IRQ */
 267
 268 struct irq_desc irq_desc[NR_IRQS] __cacheline_aligned_in_smp = {
 269         [0 ... NR_IRQS-1] = {
 270                 .handle_irq     = handle_bad_irq,
 271                 .depth          = 1,
 272                 .lock           = __RAW_SPIN_LOCK_UNLOCKED(irq_desc->lock),
 273         }
 274 };
 275
 276 int __init early_irq_init(void)
 277 {
 278         int count, i, node = first_online_node;
 279         struct irq_desc *desc;
 280
 281         init_irq_default_affinity();
 282
 283         printk(KERN_INFO "NR_IRQS:%d\n", NR_IRQS);
 284
 285         desc = irq_desc;
 286         count = ARRAY_SIZE(irq_desc);
 287
 288         for (i = 0; i < count; i++) {
 289                 desc[i].kstat_irqs = alloc_percpu(unsigned int);
 290                 alloc_masks(&desc[i], GFP_KERNEL, node);
 291                 raw_spin_lock_init(&desc[i].lock);
 292                 lockdep_set_class(&desc[i].lock, &irq_desc_lock_class);
 293                 desc_set_defaults(i, &desc[i], node, NULL);
 294         }
 295         return arch_early_irq_init();
 296 }
 297
 298 struct irq_desc *irq_to_desc(unsigned int irq)
 299 {
 300         return (irq < NR_IRQS) ? irq_desc + irq : NULL;
 301 }
 302 EXPORT_SYMBOL(irq_to_desc);
 303
 304 static void free_desc(unsigned int irq)
 305 {
 306         dynamic_irq_cleanup(irq);
 307 }
 308
 309 static inline int alloc_descs(unsigned int start, unsigned int cnt, int node,
 310                               struct module *owner)
 311 {
 312         u32 i;
 313
 314         for (i = 0; i < cnt; i++) {
 315                 struct irq_desc *desc = irq_to_desc(start + i);
 316
 317                 desc->owner = owner;
 318         }
 319         return start;
 320 }
 321
 322 static int irq_expand_nr_irqs(unsigned int nr)
 323 {
 324         return -ENOMEM;
 325 }
 326
 327 #endif /* !CONFIG_SPARSE_IRQ */
 328
 329 /**
 330  * generic_handle_irq - Invoke the handler for a particular irq
 331  * @irq:        The irq number to handle
 332  *
 333  */
 334 int generic_handle_irq(unsigned int irq)
 335 {
 336         struct irq_desc *desc = irq_to_desc(irq);
 337
 338         if (!desc)
 339                 return -EINVAL;
 340         generic_handle_irq_desc(irq, desc);
 341         return 0;
 342 }
 343 EXPORT_SYMBOL_GPL(generic_handle_irq);
 344
 345 /* Dynamic interrupt handling */
 346
 347 /**
 348  * irq_free_descs - free irq descriptors
 349  * @from:       Start of descriptor range
 350  * @cnt:        Number of consecutive irqs to free
 351  */
 352 void irq_free_descs(unsigned int from, unsigned int cnt)
 353 {
 354         int i;
 355
 356         if (from >= nr_irqs || (from + cnt) > nr_irqs)
 357                 return;
 358
 359         for (i = 0; i < cnt; i++)
 360                 free_desc(from + i);
 361
 362         mutex_lock(&sparse_irq_lock);
 363         bitmap_clear(allocated_irqs, from, cnt);
 364         mutex_unlock(&sparse_irq_lock);
 365 }
 366 EXPORT_SYMBOL_GPL(irq_free_descs);
 367
 368 /**
 369  * irq_alloc_descs - allocate and initialize a range of irq descriptors
 370  * @irq:        Allocate for specific irq number if irq >= 0
 371  * @from:       Start the search from this irq number
 372  * @cnt:        Number of consecutive irqs to allocate.
 373  * @node:       Preferred node on which the irq descriptor should be allocated
 374  * @owner:      Owning module (can be NULL)
 375  *
 376  * Returns the first irq number or error code
 377  */
 378 int __ref
 379 __irq_alloc_descs(int irq, unsigned int from, unsigned int cnt, int node,
 380                   struct module *owner)
 381 {
 382         int start, ret;
 383
 384         if (!cnt)
 385                 return -EINVAL;
 386
 387         if (irq >= 0) {
 388                 if (from > irq)
 389                         return -EINVAL;
 390                 from = irq;
 391         }
 392
 393         mutex_lock(&sparse_irq_lock);
 394
 395         start = bitmap_find_next_zero_area(allocated_irqs, IRQ_BITMAP_BITS,
 396                                            from, cnt, 0);
 397         ret = -EEXIST;
 398         if (irq >=0 && start != irq)
 399                 goto err;
 400
 401         if (start + cnt > nr_irqs) {
 402                 ret = irq_expand_nr_irqs(start + cnt);
 403                 if (ret)
 404                         goto err;
 405         }
 406
 407         bitmap_set(allocated_irqs, start, cnt);
 408         mutex_unlock(&sparse_irq_lock);
 409         return alloc_descs(start, cnt, node, owner);
 410
 411 err:
 412         mutex_unlock(&sparse_irq_lock);
 413         return ret;
 414 }
 415 EXPORT_SYMBOL_GPL(__irq_alloc_descs);
 416
 417 /**
 418  * irq_reserve_irqs - mark irqs allocated
 419  * @from:       mark from irq number
 420  * @cnt:        number of irqs to mark
 421  *
 422  * Returns 0 on success or an appropriate error code
 423  */
 424 int irq_reserve_irqs(unsigned int from, unsigned int cnt)
 425 {
 426         unsigned int start;
 427         int ret = 0;
 428
 429         if (!cnt || (from + cnt) > nr_irqs)
 430                 return -EINVAL;
 431
 432         mutex_lock(&sparse_irq_lock);
 433         start = bitmap_find_next_zero_area(allocated_irqs, nr_irqs, from, cnt, 0);
 434         if (start == from)
 435                 bitmap_set(allocated_irqs, start, cnt);
 436         else
 437                 ret = -EEXIST;
 438         mutex_unlock(&sparse_irq_lock);
 439         return ret;
 440 }
 441
 442 /**
 443  * irq_get_next_irq - get next allocated irq number
 444  * @offset:     where to start the search
 445  *
 446  * Returns next irq number after offset or nr_irqs if none is found.
 447  */
 448 unsigned int irq_get_next_irq(unsigned int offset)
 449 {
 450         return find_next_bit(allocated_irqs, nr_irqs, offset);
 451 }
 452
 453 struct irq_desc *
 454 __irq_get_desc_lock(unsigned int irq, unsigned long *flags, bool bus,
 455                     unsigned int check)
 456 {
 457         struct irq_desc *desc = irq_to_desc(irq);
 458
 459         if (desc) {
 460                 if (check & _IRQ_DESC_CHECK) {
 461                         if ((check & _IRQ_DESC_PERCPU) &&
 462                             !irq_settings_is_per_cpu_devid(desc))
 463                                 return NULL;
 464
 465                         if (!(check & _IRQ_DESC_PERCPU) &&
 466                             irq_settings_is_per_cpu_devid(desc))
 467                                 return NULL;
 468                 }
 469
 470                 if (bus)
 471                         chip_bus_lock(desc);
 472                 raw_spin_lock_irqsave(&desc->lock, *flags);
 473         }
 474         return desc;
 475 }
 476
 477 void __irq_put_desc_unlock(struct irq_desc *desc, unsigned long flags, bool bus)
 478 {
 479         raw_spin_unlock_irqrestore(&desc->lock, flags);
 480         if (bus)
 481                 chip_bus_sync_unlock(desc);
 482 }
 483
 484 int irq_set_percpu_devid(unsigned int irq)
 485 {
 486         struct irq_desc *desc = irq_to_desc(irq);
 487
 488         if (!desc)
 489                 return -EINVAL;
 490
 491         if (desc->percpu_enabled)
 492                 return -EINVAL;
 493
 494         desc->percpu_enabled = kzalloc(sizeof(*desc->percpu_enabled), GFP_KERNEL);
 495
 496         if (!desc->percpu_enabled)
 497                 return -ENOMEM;
 498
 499         irq_set_percpu_devid_flags(irq);
 500         return 0;
 501 }
 502
 503 /**
 504  * dynamic_irq_cleanup - cleanup a dynamically allocated irq
 505  * @irq:        irq number to initialize
 506  */
 507 void dynamic_irq_cleanup(unsigned int irq)
 508 {
 509         struct irq_desc *desc = irq_to_desc(irq);
 510         unsigned long flags;
 511
 512         raw_spin_lock_irqsave(&desc->lock, flags);
 513         desc_set_defaults(irq, desc, desc_node(desc), NULL);
 514         raw_spin_unlock_irqrestore(&desc->lock, flags);
 515 }
 516
 517 unsigned int kstat_irqs_cpu(unsigned int irq, int cpu)
 518 {
 519         struct irq_desc *desc = irq_to_desc(irq);
 520
 521         return desc && desc->kstat_irqs ?
 522                         *per_cpu_ptr(desc->kstat_irqs, cpu) : 0;
 523 }
 524
 525 unsigned int kstat_irqs(unsigned int irq)
 526 {
 527         struct irq_desc *desc = irq_to_desc(irq);
 528         int cpu;
 529         int sum = 0;
 530
 531         if (!desc || !desc->kstat_irqs)
 532                 return 0;
 533         for_each_possible_cpu(cpu)
 534                 sum += *per_cpu_ptr(desc->kstat_irqs, cpu);
 535         return sum;
 536 }