fs/proc/consoles.c

   1 /*
   2  * Copyright (c) 2010 Werner Fink, Jiri Slaby
   3  *
   4  * Licensed under GPLv2
   5  */
   6
   7 #include <linux/console.h>
   8 #include <linux/kernel.h>
   9 #include <linux/proc_fs.h>
  10 #include <linux/seq_file.h>
  11 #include <linux/tty_driver.h>
  12
  13 /*
  14  * This is handler for /proc/consoles
  15  */
  16 static int show_console_dev(struct seq_file *m, void *v)
  17 {
  18         static const struct {
  19                 short flag;
  20                 char name;
  21         } con_flags[] = {
  22                 { CON_ENABLED,          'E' },
  23                 { CON_CONSDEV,          'C' },
  24                 { CON_BOOT,             'B' },
  25                 { CON_PRINTBUFFER,      'p' },
  26                 { CON_BRL,              'b' },
  27                 { CON_ANYTIME,          'a' },
  28         };
  29         char flags[ARRAY_SIZE(con_flags) + 1];
  30         struct console *con = v;
  31         unsigned int a;
  32         dev_t dev = 0;
  33
  34         if (con->device) {
  35                 const struct tty_driver *driver;
  36                 int index;
  37                 driver = con->device(con, &index);
  38                 if (driver) {
  39                         dev = MKDEV(driver->major, driver->minor_start);
  40                         dev += index;
  41                 }
  42         }
  43
  44         for (a = 0; a < ARRAY_SIZE(con_flags); a++)
  45                 flags[a] = (con->flags & con_flags[a].flag) ?
  46                         con_flags[a].name : ' ';
  47         flags[a] = 0;
  48
  49         seq_setwidth(m, 21 - 1);
  50         seq_printf(m, "%s%d", con->name, con->index);
  51         seq_pad(m, ' ');
  52         seq_printf(m, "%c%c%c (%s)", con->read ? 'R' : '-',
  53                         con->write ? 'W' : '-', con->unblank ? 'U' : '-',
  54                         flags);
  55         if (dev)
  56                 seq_printf(m, " %4d:%d", MAJOR(dev), MINOR(dev));
  57
  58         seq_printf(m, "\n");
  59
  60         return 0;
  61 }
  62
  63 static void *c_start(struct seq_file *m, loff_t *pos)
  64 {
  65         struct console *con;
  66         loff_t off = 0;
  67
  68         console_lock();
  69         for_each_console(con)
  70                 if (off++ == *pos)
  71                         break;
  72
  73         return con;
  74 }
  75
  76 static void *c_next(struct seq_file *m, void *v, loff_t *pos)
  77 {
  78         struct console *con = v;
  79         ++*pos;
  80         return con->next;
  81 }
  82
  83 static void c_stop(struct seq_file *m, void *v)
  84 {
  85         console_unlock();
  86 }
  87
  88 static const struct seq_operations consoles_op = {
  89         .start  = c_start,
  90         .next   = c_next,
  91         .stop   = c_stop,
  92         .show   = show_console_dev
  93 };
  94
  95 static int consoles_open(struct inode *inode, struct file *file)
  96 {
  97         return seq_open(file, &consoles_op);
  98 }
  99
 100 static const struct file_operations proc_consoles_operations = {
 101         .open           = consoles_open,
 102         .read           = seq_read,
 103         .llseek         = seq_lseek,
 104         .release        = seq_release,
 105 };
 106
 107 static int __init proc_consoles_init(void)
 108 {
 109         proc_create("consoles", 0, NULL, &proc_consoles_operations);
 110         return 0;
 111 }
 112 fs_initcall(proc_consoles_init);