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 show_irq_affinity(int type, 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         if (type)
  32                 seq_cpumask_list(m, mask);
  33         else
  34                 seq_cpumask(m, mask);
  35         seq_putc(m, '\n');
  36         return 0;
  37 }
  38
  39 static int irq_affinity_hint_proc_show(struct seq_file *m, void *v)
  40 {
  41         struct irq_desc *desc = irq_to_desc((long)m->private);
  42         unsigned long flags;
  43         cpumask_var_t mask;
  44
  45         if (!zalloc_cpumask_var(&mask, GFP_KERNEL))
  46                 return -ENOMEM;
  47
  48         raw_spin_lock_irqsave(&desc->lock, flags);
  49         if (desc->affinity_hint)
  50                 cpumask_copy(mask, desc->affinity_hint);
  51         raw_spin_unlock_irqrestore(&desc->lock, flags);
  52
  53         seq_cpumask(m, mask);
  54         seq_putc(m, '\n');
  55         free_cpumask_var(mask);
  56
  57         return 0;
  58 }
  59
  60 #ifndef is_affinity_mask_valid
  61 #define is_affinity_mask_valid(val) 1
  62 #endif
  63
  64 int no_irq_affinity;
  65 static int irq_affinity_proc_show(struct seq_file *m, void *v)
  66 {
  67         return show_irq_affinity(0, m, v);
  68 }
  69
  70 static int irq_affinity_list_proc_show(struct seq_file *m, void *v)
  71 {
  72         return show_irq_affinity(1, m, v);
  73 }
  74
  75
  76 static ssize_t write_irq_affinity(int type, struct file *file,
  77                 const char __user *buffer, size_t count, loff_t *pos)
  78 {
  79         unsigned int irq = (int)(long)PDE(file->f_path.dentry->d_inode)->data;
  80         cpumask_var_t new_value;
  81         int err;
  82
  83         if (!irq_can_set_affinity(irq) || no_irq_affinity)
  84                 return -EIO;
  85
  86         if (!alloc_cpumask_var(&new_value, GFP_KERNEL))
  87                 return -ENOMEM;
  88
  89         if (type)
  90                 err = cpumask_parselist_user(buffer, count, new_value);
  91         else
  92                 err = cpumask_parse_user(buffer, count, new_value);
  93         if (err)
  94                 goto free_cpumask;
  95
  96         if (!is_affinity_mask_valid(new_value)) {
  97                 err = -EINVAL;
  98                 goto free_cpumask;
  99         }
 100
 101         /*
 102          * Do not allow disabling IRQs completely - it's a too easy
 103          * way to make the system unusable accidentally :-) At least
 104          * one online CPU still has to be targeted.
 105          */
 106         if (!cpumask_intersects(new_value, cpu_online_mask)) {
 107                 /* Special case for empty set - allow the architecture
 108                    code to set default SMP affinity. */
 109                 err = irq_select_affinity_usr(irq, new_value) ? -EINVAL : count;
 110         } else {
 111                 irq_set_affinity(irq, new_value);
 112                 err = count;
 113         }
 114
 115 free_cpumask:
 116         free_cpumask_var(new_value);
 117         return err;
 118 }
 119
 120 static ssize_t irq_affinity_proc_write(struct file *file,
 121                 const char __user *buffer, size_t count, loff_t *pos)
 122 {
 123         return write_irq_affinity(0, file, buffer, count, pos);
 124 }
 125
 126 static ssize_t irq_affinity_list_proc_write(struct file *file,
 127                 const char __user *buffer, size_t count, loff_t *pos)
 128 {
 129         return write_irq_affinity(1, file, buffer, count, pos);
 130 }
 131
 132 static int irq_affinity_proc_open(struct inode *inode, struct file *file)
 133 {
 134         return single_open(file, irq_affinity_proc_show, PDE(inode)->data);
 135 }
 136
 137 static int irq_affinity_list_proc_open(struct inode *inode, struct file *file)
 138 {
 139         return single_open(file, irq_affinity_list_proc_show, PDE(inode)->data);
 140 }
 141
 142 static int irq_affinity_hint_proc_open(struct inode *inode, struct file *file)
 143 {
 144         return single_open(file, irq_affinity_hint_proc_show, PDE(inode)->data);
 145 }
 146
 147 static const struct file_operations irq_affinity_proc_fops = {
 148         .open           = irq_affinity_proc_open,
 149         .read           = seq_read,
 150         .llseek         = seq_lseek,
 151         .release        = single_release,
 152         .write          = irq_affinity_proc_write,
 153 };
 154
 155 static const struct file_operations irq_affinity_hint_proc_fops = {
 156         .open           = irq_affinity_hint_proc_open,
 157         .read           = seq_read,
 158         .llseek         = seq_lseek,
 159         .release        = single_release,
 160 };
 161
 162 static const struct file_operations irq_affinity_list_proc_fops = {
 163         .open           = irq_affinity_list_proc_open,
 164         .read           = seq_read,
 165         .llseek         = seq_lseek,
 166         .release        = single_release,
 167         .write          = irq_affinity_list_proc_write,
 168 };
 169
 170 static int default_affinity_show(struct seq_file *m, void *v)
 171 {
 172         seq_cpumask(m, irq_default_affinity);
 173         seq_putc(m, '\n');
 174         return 0;
 175 }
 176
 177 static ssize_t default_affinity_write(struct file *file,
 178                 const char __user *buffer, size_t count, loff_t *ppos)
 179 {
 180         cpumask_var_t new_value;
 181         int err;
 182
 183         if (!alloc_cpumask_var(&new_value, GFP_KERNEL))
 184                 return -ENOMEM;
 185
 186         err = cpumask_parse_user(buffer, count, new_value);
 187         if (err)
 188                 goto out;
 189
 190         if (!is_affinity_mask_valid(new_value)) {
 191                 err = -EINVAL;
 192                 goto out;
 193         }
 194
 195         /*
 196          * Do not allow disabling IRQs completely - it's a too easy
 197          * way to make the system unusable accidentally :-) At least
 198          * one online CPU still has to be targeted.
 199          */
 200         if (!cpumask_intersects(new_value, cpu_online_mask)) {
 201                 err = -EINVAL;
 202                 goto out;
 203         }
 204
 205         cpumask_copy(irq_default_affinity, new_value);
 206         err = count;
 207
 208 out:
 209         free_cpumask_var(new_value);
 210         return err;
 211 }
 212
 213 static int default_affinity_open(struct inode *inode, struct file *file)
 214 {
 215         return single_open(file, default_affinity_show, PDE(inode)->data);
 216 }
 217
 218 static const struct file_operations default_affinity_proc_fops = {
 219         .open           = default_affinity_open,
 220         .read           = seq_read,
 221         .llseek         = seq_lseek,
 222         .release        = single_release,
 223         .write          = default_affinity_write,
 224 };
 225
 226 static int irq_node_proc_show(struct seq_file *m, void *v)
 227 {
 228         struct irq_desc *desc = irq_to_desc((long) m->private);
 229
 230         seq_printf(m, "%d\n", desc->irq_data.node);
 231         return 0;
 232 }
 233
 234 static int irq_node_proc_open(struct inode *inode, struct file *file)
 235 {
 236         return single_open(file, irq_node_proc_show, PDE(inode)->data);
 237 }
 238
 239 static const struct file_operations irq_node_proc_fops = {
 240         .open           = irq_node_proc_open,
 241         .read           = seq_read,
 242         .llseek         = seq_lseek,
 243         .release        = single_release,
 244 };
 245 #endif
 246
 247 static int irq_spurious_proc_show(struct seq_file *m, void *v)
 248 {
 249         struct irq_desc *desc = irq_to_desc((long) m->private);
 250
 251         seq_printf(m, "count %u\n" "unhandled %u\n" "last_unhandled %u ms\n",
 252                    desc->irq_count, desc->irqs_unhandled,
 253                    jiffies_to_msecs(desc->last_unhandled));
 254         return 0;
 255 }
 256
 257 static int irq_spurious_proc_open(struct inode *inode, struct file *file)
 258 {
 259         return single_open(file, irq_spurious_proc_show, PDE(inode)->data);
 260 }
 261
 262 static const struct file_operations irq_spurious_proc_fops = {
 263         .open           = irq_spurious_proc_open,
 264         .read           = seq_read,
 265         .llseek         = seq_lseek,
 266         .release        = single_release,
 267 };
 268
 269 #define MAX_NAMELEN 128
 270
 271 static int name_unique(unsigned int irq, struct irqaction *new_action)
 272 {
 273         struct irq_desc *desc = irq_to_desc(irq);
 274         struct irqaction *action;
 275         unsigned long flags;
 276         int ret = 1;
 277
 278         raw_spin_lock_irqsave(&desc->lock, flags);
 279         for (action = desc->action ; action; action = action->next) {
 280                 if ((action != new_action) && action->name &&
 281                                 !strcmp(new_action->name, action->name)) {
 282                         ret = 0;
 283                         break;
 284                 }
 285         }
 286         raw_spin_unlock_irqrestore(&desc->lock, flags);
 287         return ret;
 288 }
 289
 290 void register_handler_proc(unsigned int irq, struct irqaction *action)
 291 {
 292         char name [MAX_NAMELEN];
 293         struct irq_desc *desc = irq_to_desc(irq);
 294
 295         if (!desc->dir || action->dir || !action->name ||
 296                                         !name_unique(irq, action))
 297                 return;
 298
 299         memset(name, 0, MAX_NAMELEN);
 300         snprintf(name, MAX_NAMELEN, "%s", action->name);
 301
 302         /* create /proc/irq/1234/handler/ */
 303         action->dir = proc_mkdir(name, desc->dir);
 304 }
 305
 306 #undef MAX_NAMELEN
 307
 308 #define MAX_NAMELEN 10
 309
 310 void register_irq_proc(unsigned int irq, struct irq_desc *desc)
 311 {
 312         char name [MAX_NAMELEN];
 313
 314         if (!root_irq_dir || (desc->irq_data.chip == &no_irq_chip) || desc->dir)
 315                 return;
 316
 317         memset(name, 0, MAX_NAMELEN);
 318         sprintf(name, "%d", irq);
 319
 320         /* create /proc/irq/1234 */
 321         desc->dir = proc_mkdir(name, root_irq_dir);
 322         if (!desc->dir)
 323                 return;
 324
 325 #ifdef CONFIG_SMP
 326         /* create /proc/irq/<irq>/smp_affinity */
 327         proc_create_data("smp_affinity", 0600, desc->dir,
 328                          &irq_affinity_proc_fops, (void *)(long)irq);
 329
 330         /* create /proc/irq/<irq>/affinity_hint */
 331         proc_create_data("affinity_hint", 0400, desc->dir,
 332                          &irq_affinity_hint_proc_fops, (void *)(long)irq);
 333
 334         /* create /proc/irq/<irq>/smp_affinity_list */
 335         proc_create_data("smp_affinity_list", 0600, desc->dir,
 336                          &irq_affinity_list_proc_fops, (void *)(long)irq);
 337
 338         proc_create_data("node", 0444, desc->dir,
 339                          &irq_node_proc_fops, (void *)(long)irq);
 340 #endif
 341
 342         proc_create_data("spurious", 0444, desc->dir,
 343                          &irq_spurious_proc_fops, (void *)(long)irq);
 344 }
 345
 346 void unregister_irq_proc(unsigned int irq, struct irq_desc *desc)
 347 {
 348         char name [MAX_NAMELEN];
 349
 350         if (!root_irq_dir || !desc->dir)
 351                 return;
 352 #ifdef CONFIG_SMP
 353         remove_proc_entry("smp_affinity", desc->dir);
 354         remove_proc_entry("affinity_hint", desc->dir);
 355         remove_proc_entry("node", desc->dir);
 356 #endif
 357         remove_proc_entry("spurious", desc->dir);
 358
 359         memset(name, 0, MAX_NAMELEN);
 360         sprintf(name, "%u", irq);
 361         remove_proc_entry(name, root_irq_dir);
 362 }
 363
 364 #undef MAX_NAMELEN
 365
 366 void unregister_handler_proc(unsigned int irq, struct irqaction *action)
 367 {
 368         if (action->dir) {
 369                 struct irq_desc *desc = irq_to_desc(irq);
 370
 371                 remove_proc_entry(action->dir->name, desc->dir);
 372         }
 373 }
 374
 375 static void register_default_affinity_proc(void)
 376 {
 377 #ifdef CONFIG_SMP
 378         proc_create("irq/default_smp_affinity", 0600, NULL,
 379                     &default_affinity_proc_fops);
 380 #endif
 381 }
 382
 383 void init_irq_proc(void)
 384 {
 385         unsigned int irq;
 386         struct irq_desc *desc;
 387
 388         /* create /proc/irq */
 389         root_irq_dir = proc_mkdir("irq", NULL);
 390         if (!root_irq_dir)
 391                 return;
 392
 393         register_default_affinity_proc();
 394
 395         /*
 396          * Create entries for all existing IRQs.
 397          */
 398         for_each_irq_desc(irq, desc) {
 399                 if (!desc)
 400                         continue;
 401
 402                 register_irq_proc(irq, desc);
 403         }
 404 }
 405
 406 #ifdef CONFIG_GENERIC_IRQ_SHOW
 407
 408 int __weak arch_show_interrupts(struct seq_file *p, int prec)
 409 {
 410         return 0;
 411 }
 412
 413 #ifndef ACTUAL_NR_IRQS
 414 # define ACTUAL_NR_IRQS nr_irqs
 415 #endif
 416
 417 int show_interrupts(struct seq_file *p, void *v)
 418 {
 419         static int prec;
 420
 421         unsigned long flags, any_count = 0;
 422         int i = *(loff_t *) v, j;
 423         struct irqaction *action;
 424         struct irq_desc *desc;
 425
 426         if (i > ACTUAL_NR_IRQS)
 427                 return 0;
 428
 429         if (i == ACTUAL_NR_IRQS)
 430                 return arch_show_interrupts(p, prec);
 431
 432         /* print header and calculate the width of the first column */
 433         if (i == 0) {
 434                 for (prec = 3, j = 1000; prec < 10 && j <= nr_irqs; ++prec)
 435                         j *= 10;
 436
 437                 seq_printf(p, "%*s", prec + 8, "");
 438                 for_each_online_cpu(j)
 439                         seq_printf(p, "CPU%-8d", j);
 440                 seq_putc(p, '\n');
 441         }
 442
 443         desc = irq_to_desc(i);
 444         if (!desc)
 445                 return 0;
 446
 447         raw_spin_lock_irqsave(&desc->lock, flags);
 448         for_each_online_cpu(j)
 449                 any_count |= kstat_irqs_cpu(i, j);
 450         action = desc->action;
 451         if (!action && !any_count)
 452                 goto out;
 453
 454         seq_printf(p, "%*d: ", prec, i);
 455         for_each_online_cpu(j)
 456                 seq_printf(p, "%10u ", kstat_irqs_cpu(i, j));
 457
 458         if (desc->irq_data.chip) {
 459                 if (desc->irq_data.chip->irq_print_chip)
 460                         desc->irq_data.chip->irq_print_chip(&desc->irq_data, p);
 461                 else if (desc->irq_data.chip->name)
 462                         seq_printf(p, " %8s", desc->irq_data.chip->name);
 463                 else
 464                         seq_printf(p, " %8s", "-");
 465         } else {
 466                 seq_printf(p, " %8s", "None");
 467         }
 468 #ifdef CONFIG_GENERIC_IRQ_SHOW_LEVEL
 469         seq_printf(p, " %-8s", irqd_is_level_type(&desc->irq_data) ? "Level" : "Edge");
 470 #endif
 471         if (desc->name)
 472                 seq_printf(p, "-%-8s", desc->name);
 473
 474         if (action) {
 475                 seq_printf(p, "  %s", action->name);
 476                 while ((action = action->next) != NULL)
 477                         seq_printf(p, ", %s", action->name);
 478         }
 479
 480         seq_putc(p, '\n');
 481 out:
 482         raw_spin_unlock_irqrestore(&desc->lock, flags);
 483         return 0;
 484 }
 485 #endif