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