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