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_putc(m, '\n');
  59         return 0;
  60 }
  61
  62 static void *c_start(struct seq_file *m, loff_t *pos)
  63 {
  64         struct console *con;
  65         loff_t off = 0;
  66
  67         console_lock();
  68         for_each_console(con)
  69                 if (off++ == *pos)
  70                         break;
  71
  72         return con;
  73 }
  74
  75 static void *c_next(struct seq_file *m, void *v, loff_t *pos)
  76 {
  77         struct console *con = v;
  78         ++*pos;
  79         return con->next;
  80 }
  81
  82 static void c_stop(struct seq_file *m, void *v)
  83 {
  84         console_unlock();
  85 }
  86
  87 static const struct seq_operations consoles_op = {
  88         .start  = c_start,
  89         .next   = c_next,
  90         .stop   = c_stop,
  91         .show   = show_console_dev
  92 };
  93
  94 static int consoles_open(struct inode *inode, struct file *file)
  95 {
  96         return seq_open(file, &consoles_op);
  97 }
  98
  99 static const struct file_operations proc_consoles_operations = {
 100         .open           = consoles_open,
 101         .read           = seq_read,
 102         .llseek         = seq_lseek,
 103         .release        = seq_release,
 104 };
 105
 106 static int __init proc_consoles_init(void)
 107 {
 108         proc_create("consoles", 0, NULL, &proc_consoles_operations);
 109         return 0;
 110 }
 111 fs_initcall(proc_consoles_init);