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