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