kernel/irq/proc.c

   1 /*
   2  * linux/kernel/irq/proc.c
   3  *
   4  * Copyright (C) 1992, 1998-2004 Linus Torvalds, Ingo Molnar
   5  *
   6  * This file contains the /proc/irq/ handling code.
   7  */
   8
   9 #include <linux/irq.h>
  10 #include <linux/gfp.h>
  11 #include <linux/proc_fs.h>
  12 #include <linux/seq_file.h>
  13 #include <linux/interrupt.h>
  14 #include <linux/kernel_stat.h>
  15
  16 #include "internals.h"
  17
  18 static struct proc_dir_entry *root_irq_dir;
  19
  20 #ifdef CONFIG_SMP
  21
  22 static int irq_affinity_proc_show(struct seq_file *m, void *v)
  23 {
  24         struct irq_desc *desc = irq_to_desc((long)m->private);
  25         const struct cpumask *mask = desc->irq_data.affinity;
  26
  27 #ifdef CONFIG_GENERIC_PENDING_IRQ
  28         if (irqd_is_setaffinity_pending(&desc->irq_data))
  29                 mask = desc->pending_mask;
  30 #endif
  31         seq_cpumask(m, mask);
  32         seq_putc(m, '\n');
  33         return 0;
  34 }
  35
  36 static int irq_affinity_hint_proc_show(struct seq_file *m, void *v)
  37 {
  38         struct irq_desc *desc = irq_to_desc((long)m->private);
  39         unsigned long flags;
  40         cpumask_var_t mask;
  41
  42         if (!zalloc_cpumask_var(&mask, GFP_KERNEL))
  43                 return -ENOMEM;
  44
  45         raw_spin_lock_irqsave(&desc->lock, flags);
  46         if (desc->affinity_hint)
  47                 cpumask_copy(mask, desc->affinity_hint);
  48         raw_spin_unlock_irqrestore(&desc->lock, flags);
  49
  50         seq_cpumask(m, mask);
  51         seq_putc(m, '\n');
  52         free_cpumask_var(mask);
  53
  54         return 0;
  55 }
  56
  57 #ifndef is_affinity_mask_valid
  58 #define is_affinity_mask_valid(val) 1
  59 #endif
  60
  61 int no_irq_affinity;
  62 static ssize_t irq_affinity_proc_write(struct file *file,
  63                 const char __user *buffer, size_t count, loff_t *pos)
  64 {
  65         unsigned int irq = (int)(long)PDE(file->f_path.dentry->d_inode)->data;
  66         cpumask_var_t new_value;
  67         int err;
  68
  69         if (!irq_to_desc(irq)->irq_data.chip->irq_set_affinity || no_irq_affinity ||
  70             irq_balancing_disabled(irq))
  71                 return -EIO;
  72
  73         if (!alloc_cpumask_var(&new_value, GFP_KERNEL))
  74                 return -ENOMEM;
  75
  76         err = cpumask_parse_user(buffer, count, new_value);
  77         if (err)
  78                 goto free_cpumask;
  79
  80         if (!is_affinity_mask_valid(new_value)) {
  81                 err = -EINVAL;
  82                 goto free_cpumask;
  83         }
  84
  85         /*
  86          * Do not allow disabling IRQs completely - it's a too easy
  87          * way to make the system unusable accidentally :-) At least
  88          * one online CPU still has to be targeted.
  89          */
  90         if (!cpumask_intersects(new_value, cpu_online_mask)) {
  91                 /* Special case for empty set - allow the architecture
  92                    code to set default SMP affinity. */
  93                 err = irq_select_affinity_usr(irq, new_value) ? -EINVAL : count;
  94         } else {
  95                 irq_set_affinity(irq, new_value);
  96                 err = count;
  97         }
  98
  99 free_cpumask:
 100         free_cpumask_var(new_value);
 101         return err;
 102 }
 103
 104 static int irq_affinity_proc_open(struct inode *inode, struct file *file)
 105 {
 106         return single_open(file, irq_affinity_proc_show, PDE(inode)->data);
 107 }
 108
 109 static int irq_affinity_hint_proc_open(struct inode *inode, struct file *file)
 110 {
 111         return single_open(file, irq_affinity_hint_proc_show, PDE(inode)->data);
 112 }
 113
 114 static const struct file_operations irq_affinity_proc_fops = {
 115         .open           = irq_affinity_proc_open,
 116         .read           = seq_read,
 117         .llseek         = seq_lseek,
 118         .release        = single_release,
 119         .write          = irq_affinity_proc_write,
 120 };
 121
 122 static const struct file_operations irq_affinity_hint_proc_fops = {
 123         .open           = irq_affinity_hint_proc_open,
 124         .read           = seq_read,
 125         .llseek         = seq_lseek,
 126         .release        = single_release,
 127 };
 128
 129 static int default_affinity_show(struct seq_file *m, void *v)
 130 {
 131         seq_cpumask(m, irq_default_affinity);
 132         seq_putc(m, '\n');
 133         return 0;
 134 }
 135
 136 static ssize_t default_affinity_write(struct file *file,
 137                 const char __user *buffer, size_t count, loff_t *ppos)
 138 {
 139         cpumask_var_t new_value;
 140         int err;
 141
 142         if (!alloc_cpumask_var(&new_value, GFP_KERNEL))
 143                 return -ENOMEM;
 144
 145         err = cpumask_parse_user(buffer, count, new_value);
 146         if (err)
 147                 goto out;
 148
 149         if (!is_affinity_mask_valid(new_value)) {
 150                 err = -EINVAL;
 151                 goto out;
 152         }
 153
 154         /*
 155          * Do not allow disabling IRQs completely - it's a too easy
 156          * way to make the system unusable accidentally :-) At least
 157          * one online CPU still has to be targeted.
 158          */
 159         if (!cpumask_intersects(new_value, cpu_online_mask)) {
 160                 err = -EINVAL;
 161                 goto out;
 162         }
 163
 164         cpumask_copy(irq_default_affinity, new_value);
 165         err = count;
 166
 167 out:
 168         free_cpumask_var(new_value);
 169         return err;
 170 }
 171
 172 static int default_affinity_open(struct inode *inode, struct file *file)
 173 {
 174         return single_open(file, default_affinity_show, PDE(inode)->data);
 175 }
 176
 177 static const struct file_operations default_affinity_proc_fops = {
 178         .open           = default_affinity_open,
 179         .read           = seq_read,
 180         .llseek         = seq_lseek,
 181         .release        = single_release,
 182         .write          = default_affinity_write,
 183 };
 184
 185 static int irq_node_proc_show(struct seq_file *m, void *v)
 186 {
 187         struct irq_desc *desc = irq_to_desc((long) m->private);
 188
 189         seq_printf(m, "%d\n", desc->irq_data.node);
 190         return 0;
 191 }
 192
 193 static int irq_node_proc_open(struct inode *inode, struct file *file)
 194 {
 195         return single_open(file, irq_node_proc_show, PDE(inode)->data);
 196 }
 197
 198 static const struct file_operations irq_node_proc_fops = {
 199         .open           = irq_node_proc_open,
 200         .read           = seq_read,
 201         .llseek         = seq_lseek,
 202         .release        = single_release,
 203 };
 204 #endif
 205
 206 static int irq_spurious_proc_show(struct seq_file *m, void *v)
 207 {
 208         struct irq_desc *desc = irq_to_desc((long) m->private);
 209
 210         seq_printf(m, "count %u\n" "unhandled %u\n" "last_unhandled %u ms\n",
 211                    desc->irq_count, desc->irqs_unhandled,
 212                    jiffies_to_msecs(desc->last_unhandled));
 213         return 0;
 214 }
 215
 216 static int irq_spurious_proc_open(struct inode *inode, struct file *file)
 217 {
 218         return single_open(file, irq_spurious_proc_show, PDE(inode)->data);
 219 }
 220
 221 static const struct file_operations irq_spurious_proc_fops = {
 222         .open           = irq_spurious_proc_open,
 223         .read           = seq_read,
 224         .llseek         = seq_lseek,
 225         .release        = single_release,
 226 };
 227
 228 #define MAX_NAMELEN 128
 229
 230 static int name_unique(unsigned int irq, struct irqaction *new_action)
 231 {
 232         struct irq_desc *desc = irq_to_desc(irq);
 233         struct irqaction *action;
 234         unsigned long flags;
 235         int ret = 1;
 236
 237         raw_spin_lock_irqsave(&desc->lock, flags);
 238         for (action = desc->action ; action; action = action->next) {
 239                 if ((action != new_action) && action->name &&
 240                                 !strcmp(new_action->name, action->name)) {
 241                         ret = 0;
 242                         break;
 243                 }
 244         }
 245         raw_spin_unlock_irqrestore(&desc->lock, flags);
 246         return ret;
 247 }
 248
 249 void register_handler_proc(unsigned int irq, struct irqaction *action)
 250 {
 251         char name [MAX_NAMELEN];
 252         struct irq_desc *desc = irq_to_desc(irq);
 253
 254         if (!desc->dir || action->dir || !action->name ||
 255                                         !name_unique(irq, action))
 256                 return;
 257
 258         memset(name, 0, MAX_NAMELEN);
 259         snprintf(name, MAX_NAMELEN, "%s", action->name);
 260
 261         /* create /proc/irq/1234/handler/ */
 262         action->dir = proc_mkdir(name, desc->dir);
 263 }
 264
 265 #undef MAX_NAMELEN
 266
 267 #define MAX_NAMELEN 10
 268
 269 void register_irq_proc(unsigned int irq, struct irq_desc *desc)
 270 {
 271         char name [MAX_NAMELEN];
 272
 273         if (!root_irq_dir || (desc->irq_data.chip == &no_irq_chip) || desc->dir)
 274                 return;
 275
 276         memset(name, 0, MAX_NAMELEN);
 277         sprintf(name, "%d", irq);
 278
 279         /* create /proc/irq/1234 */
 280         desc->dir = proc_mkdir(name, root_irq_dir);
 281         if (!desc->dir)
 282                 return;
 283
 284 #ifdef CONFIG_SMP
 285         /* create /proc/irq/<irq>/smp_affinity */
 286         proc_create_data("smp_affinity", 0600, desc->dir,
 287                          &irq_affinity_proc_fops, (void *)(long)irq);
 288
 289         /* create /proc/irq/<irq>/affinity_hint */
 290         proc_create_data("affinity_hint", 0400, desc->dir,
 291                          &irq_affinity_hint_proc_fops, (void *)(long)irq);
 292
 293         proc_create_data("node", 0444, desc->dir,
 294                          &irq_node_proc_fops, (void *)(long)irq);
 295 #endif
 296
 297         proc_create_data("spurious", 0444, desc->dir,
 298                          &irq_spurious_proc_fops, (void *)(long)irq);
 299 }
 300
 301 void unregister_irq_proc(unsigned int irq, struct irq_desc *desc)
 302 {
 303         char name [MAX_NAMELEN];
 304
 305         if (!root_irq_dir || !desc->dir)
 306                 return;
 307 #ifdef CONFIG_SMP
 308         remove_proc_entry("smp_affinity", desc->dir);
 309         remove_proc_entry("affinity_hint", desc->dir);
 310         remove_proc_entry("node", desc->dir);
 311 #endif
 312         remove_proc_entry("spurious", desc->dir);
 313
 314         memset(name, 0, MAX_NAMELEN);
 315         sprintf(name, "%u", irq);
 316         remove_proc_entry(name, root_irq_dir);
 317 }
 318
 319 #undef MAX_NAMELEN
 320
 321 void unregister_handler_proc(unsigned int irq, struct irqaction *action)
 322 {
 323         if (action->dir) {
 324                 struct irq_desc *desc = irq_to_desc(irq);
 325
 326                 remove_proc_entry(action->dir->name, desc->dir);
 327         }
 328 }
 329
 330 static void register_default_affinity_proc(void)
 331 {
 332 #ifdef CONFIG_SMP
 333         proc_create("irq/default_smp_affinity", 0600, NULL,
 334                     &default_affinity_proc_fops);
 335 #endif
 336 }
 337
 338 void init_irq_proc(void)
 339 {
 340         unsigned int irq;
 341         struct irq_desc *desc;
 342
 343         /* create /proc/irq */
 344         root_irq_dir = proc_mkdir("irq", NULL);
 345         if (!root_irq_dir)
 346                 return;
 347
 348         register_default_affinity_proc();
 349
 350         /*
 351          * Create entries for all existing IRQs.
 352          */
 353         for_each_irq_desc(irq, desc) {
 354                 if (!desc)
 355                         continue;
 356
 357                 register_irq_proc(irq, desc);
 358         }
 359 }
 360
 361 #ifdef CONFIG_GENERIC_IRQ_SHOW
 362
 363 int __weak arch_show_interrupts(struct seq_file *p, int prec)
 364 {
 365         return 0;
 366 }
 367
 368 int show_interrupts(struct seq_file *p, void *v)
 369 {
 370         static int prec;
 371
 372         unsigned long flags, any_count = 0;
 373         int i = *(loff_t *) v, j;
 374         struct irqaction *action;
 375         struct irq_desc *desc;
 376
 377         if (i > nr_irqs)
 378                 return 0;
 379
 380         if (i == nr_irqs)
 381                 return arch_show_interrupts(p, prec);
 382
 383         /* print header and calculate the width of the first column */
 384         if (i == 0) {
 385                 for (prec = 3, j = 1000; prec < 10 && j <= nr_irqs; ++prec)
 386                         j *= 10;
 387
 388                 seq_printf(p, "%*s", prec + 8, "");
 389                 for_each_online_cpu(j)
 390                         seq_printf(p, "CPU%-8d", j);
 391                 seq_putc(p, '\n');
 392         }
 393
 394         desc = irq_to_desc(i);
 395         if (!desc)
 396                 return 0;
 397
 398         raw_spin_lock_irqsave(&desc->lock, flags);
 399         for_each_online_cpu(j)
 400                 any_count |= kstat_irqs_cpu(i, j);
 401         action = desc->action;
 402         if (!action && !any_count)
 403                 goto out;
 404
 405         seq_printf(p, "%*d: ", prec, i);
 406         for_each_online_cpu(j)
 407                 seq_printf(p, "%10u ", kstat_irqs_cpu(i, j));
 408         seq_printf(p, " %8s", desc->irq_data.chip->name);
 409         seq_printf(p, "-%-8s", desc->name);
 410
 411         if (action) {
 412                 seq_printf(p, "  %s", action->name);
 413                 while ((action = action->next) != NULL)
 414                         seq_printf(p, ", %s", action->name);
 415         }
 416
 417         seq_putc(p, '\n');
 418 out:
 419         raw_spin_unlock_irqrestore(&desc->lock, flags);
 420         return 0;
 421 }
 422 #endif