kernel/irq/irqdesc.c

   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 }