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