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 } 277 278 static void free_desc(unsigned int irq) 279 { 280 dynamic_irq_cleanup(irq); 281 } 282 283 static inline int alloc_descs(unsigned int start, unsigned int cnt, int node, 284 struct module *owner) 285 { 286 u32 i; 287 288 for (i = 0; i < cnt; i++) { 289 struct irq_desc *desc = irq_to_desc(start + i); 290 291 desc->owner = owner; 292 } 293 return start; 294 } 295 296 static int irq_expand_nr_irqs(unsigned int nr) 297 { 298 return -ENOMEM; 299 } 300 301 #endif /* !CONFIG_SPARSE_IRQ */ 302 303 /** 304 * generic_handle_irq - Invoke the handler for a particular irq 305 * @irq: The irq number to handle 306 * 307 */ 308 int generic_handle_irq(unsigned int irq) 309 { 310 struct irq_desc *desc = irq_to_desc(irq); 311 312 if (!desc) 313 return -EINVAL; 314 generic_handle_irq_desc(irq, desc); 315 return 0; 316 } 317 EXPORT_SYMBOL_GPL(generic_handle_irq); 318 319 /* Dynamic interrupt handling */ 320 321 /** 322 * irq_free_descs - free irq descriptors 323 * @from: Start of descriptor range 324 * @cnt: Number of consecutive irqs to free 325 */ 326 void irq_free_descs(unsigned int from, unsigned int cnt) 327 { 328 int i; 329 330 if (from >= nr_irqs || (from + cnt) > nr_irqs) 331 return; 332 333 for (i = 0; i < cnt; i++) 334 free_desc(from + i); 335 336 mutex_lock(&sparse_irq_lock); 337 bitmap_clear(allocated_irqs, from, cnt); 338 mutex_unlock(&sparse_irq_lock); 339 } 340 EXPORT_SYMBOL_GPL(irq_free_descs); 341 342 /** 343 * irq_alloc_descs - allocate and initialize a range of irq descriptors 344 * @irq: Allocate for specific irq number if irq >= 0 345 * @from: Start the search from this irq number 346 * @cnt: Number of consecutive irqs to allocate. 347 * @node: Preferred node on which the irq descriptor should be allocated 348 * @owner: Owning module (can be NULL) 349 * 350 * Returns the first irq number or error code 351 */ 352 int __ref 353 __irq_alloc_descs(int irq, unsigned int from, unsigned int cnt, int node, 354 struct module *owner) 355 { 356 int start, ret; 357 358 if (!cnt) 359 return -EINVAL; 360 361 if (irq >= 0) { 362 if (from > irq) 363 return -EINVAL; 364 from = irq; 365 } 366 367 mutex_lock(&sparse_irq_lock); 368 369 start = bitmap_find_next_zero_area(allocated_irqs, IRQ_BITMAP_BITS, 370 from, cnt, 0); 371 ret = -EEXIST; 372 if (irq >=0 && start != irq) 373 goto err; 374 375 if (start + cnt > nr_irqs) { 376 ret = irq_expand_nr_irqs(start + cnt); 377 if (ret) 378 goto err; 379 } 380 381 bitmap_set(allocated_irqs, start, cnt); 382 mutex_unlock(&sparse_irq_lock); 383 return alloc_descs(start, cnt, node, owner); 384 385 err: 386 mutex_unlock(&sparse_irq_lock); 387 return ret; 388 } 389 EXPORT_SYMBOL_GPL(__irq_alloc_descs); 390 391 /** 392 * irq_reserve_irqs - mark irqs allocated 393 * @from: mark from irq number 394 * @cnt: number of irqs to mark 395 * 396 * Returns 0 on success or an appropriate error code 397 */ 398 int irq_reserve_irqs(unsigned int from, unsigned int cnt) 399 { 400 unsigned int start; 401 int ret = 0; 402 403 if (!cnt || (from + cnt) > nr_irqs) 404 return -EINVAL; 405 406 mutex_lock(&sparse_irq_lock); 407 start = bitmap_find_next_zero_area(allocated_irqs, nr_irqs, from, cnt, 0); 408 if (start == from) 409 bitmap_set(allocated_irqs, start, cnt); 410 else 411 ret = -EEXIST; 412 mutex_unlock(&sparse_irq_lock); 413 return ret; 414 } 415 416 /** 417 * irq_get_next_irq - get next allocated irq number 418 * @offset: where to start the search 419 * 420 * Returns next irq number after offset or nr_irqs if none is found. 421 */ 422 unsigned int irq_get_next_irq(unsigned int offset) 423 { 424 return find_next_bit(allocated_irqs, nr_irqs, offset); 425 } 426 427 struct irq_desc * 428 __irq_get_desc_lock(unsigned int irq, unsigned long *flags, bool bus, 429 unsigned int check) 430 { 431 struct irq_desc *desc = irq_to_desc(irq); 432 433 if (desc) { 434 if (check & _IRQ_DESC_CHECK) { 435 if ((check & _IRQ_DESC_PERCPU) && 436 !irq_settings_is_per_cpu_devid(desc)) 437 return NULL; 438 439 if (!(check & _IRQ_DESC_PERCPU) && 440 irq_settings_is_per_cpu_devid(desc)) 441 return NULL; 442 } 443 444 if (bus) 445 chip_bus_lock(desc); 446 raw_spin_lock_irqsave(&desc->lock, *flags); 447 } 448 return desc; 449 } 450 451 void __irq_put_desc_unlock(struct irq_desc *desc, unsigned long flags, bool bus) 452 { 453 raw_spin_unlock_irqrestore(&desc->lock, flags); 454 if (bus) 455 chip_bus_sync_unlock(desc); 456 } 457 458 int irq_set_percpu_devid(unsigned int irq) 459 { 460 struct irq_desc *desc = irq_to_desc(irq); 461 462 if (!desc) 463 return -EINVAL; 464 465 if (desc->percpu_enabled) 466 return -EINVAL; 467 468 desc->percpu_enabled = kzalloc(sizeof(*desc->percpu_enabled), GFP_KERNEL); 469 470 if (!desc->percpu_enabled) 471 return -ENOMEM; 472 473 irq_set_percpu_devid_flags(irq); 474 return 0; 475 } 476 477 /** 478 * dynamic_irq_cleanup - cleanup a dynamically allocated irq 479 * @irq: irq number to initialize 480 */ 481 void dynamic_irq_cleanup(unsigned int irq) 482 { 483 struct irq_desc *desc = irq_to_desc(irq); 484 unsigned long flags; 485 486 raw_spin_lock_irqsave(&desc->lock, flags); 487 desc_set_defaults(irq, desc, desc_node(desc), NULL); 488 raw_spin_unlock_irqrestore(&desc->lock, flags); 489 } 490 491 unsigned int kstat_irqs_cpu(unsigned int irq, int cpu) 492 { 493 struct irq_desc *desc = irq_to_desc(irq); 494 495 return desc && desc->kstat_irqs ? 496 *per_cpu_ptr(desc->kstat_irqs, cpu) : 0; 497 } 498 499 unsigned int kstat_irqs(unsigned int irq) 500 { 501 struct irq_desc *desc = irq_to_desc(irq); 502 int cpu; 503 int sum = 0; 504 505 if (!desc || !desc->kstat_irqs) 506 return 0; 507 for_each_possible_cpu(cpu) 508 sum += *per_cpu_ptr(desc->kstat_irqs, cpu); 509 return sum; 510 } 511