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 } 115 116 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 unsigned int check) 429 { 430 struct irq_desc *desc = irq_to_desc(irq); 431 432 if (desc) { 433 if (check & _IRQ_DESC_CHECK) { 434 if ((check & _IRQ_DESC_PERCPU) && 435 !irq_settings_is_per_cpu_devid(desc)) 436 return NULL; 437 438 if (!(check & _IRQ_DESC_PERCPU) && 439 irq_settings_is_per_cpu_devid(desc)) 440 return NULL; 441 } 442 443 if (bus) 444 chip_bus_lock(desc); 445 raw_spin_lock_irqsave(&desc->lock, *flags); 446 } 447 return desc; 448 } 449 450 void __irq_put_desc_unlock(struct irq_desc *desc, unsigned long flags, bool bus) 451 { 452 raw_spin_unlock_irqrestore(&desc->lock, flags); 453 if (bus) 454 chip_bus_sync_unlock(desc); 455 } 456 457 int irq_set_percpu_devid(unsigned int irq) 458 { 459 struct irq_desc *desc = irq_to_desc(irq); 460 461 if (!desc) 462 return -EINVAL; 463 464 if (desc->percpu_enabled) 465 return -EINVAL; 466 467 desc->percpu_enabled = kzalloc(sizeof(*desc->percpu_enabled), GFP_KERNEL); 468 469 if (!desc->percpu_enabled) 470 return -ENOMEM; 471 472 irq_set_percpu_devid_flags(irq); 473 return 0; 474 } 475 476 /** 477 * dynamic_irq_cleanup - cleanup a dynamically allocated irq 478 * @irq: irq number to initialize 479 */ 480 void dynamic_irq_cleanup(unsigned int irq) 481 { 482 struct irq_desc *desc = irq_to_desc(irq); 483 unsigned long flags; 484 485 raw_spin_lock_irqsave(&desc->lock, flags); 486 desc_set_defaults(irq, desc, desc_node(desc), NULL); 487 raw_spin_unlock_irqrestore(&desc->lock, flags); 488 } 489 490 unsigned int kstat_irqs_cpu(unsigned int irq, int cpu) 491 { 492 struct irq_desc *desc = irq_to_desc(irq); 493 494 return desc && desc->kstat_irqs ? 495 *per_cpu_ptr(desc->kstat_irqs, cpu) : 0; 496 } 497 498 unsigned int kstat_irqs(unsigned int irq) 499 { 500 struct irq_desc *desc = irq_to_desc(irq); 501 int cpu; 502 int sum = 0; 503 504 if (!desc || !desc->kstat_irqs) 505 return 0; 506 for_each_possible_cpu(cpu) 507 sum += *per_cpu_ptr(desc->kstat_irqs, cpu); 508 return sum; 509 } 510