include/linux/sysrq.h

   1 /* -*- linux-c -*-
   2  *
   3  *      $Id: sysrq.h,v 1.3 1997/07/17 11:54:33 mj Exp $
   4  *
   5  *      Linux Magic System Request Key Hacks
   6  *
   7  *      (c) 1997 Martin Mares <mj@atrey.karlin.mff.cuni.cz>
   8  *
   9  *      (c) 2000 Crutcher Dunnavant <crutcher+kernel@datastacks.com>
  10  *      overhauled to use key registration
  11  *      based upon discusions in irc://irc.openprojects.net/#kernelnewbies
  12  */
  13
  14 #ifndef _LINUX_SYSRQ_H
  15 #define _LINUX_SYSRQ_H
  16
  17 #include <linux/errno.h>
  18 #include <linux/types.h>
  19
  20 /* Possible values of bitmask for enabling sysrq functions */
  21 /* 0x0001 is reserved for enable everything */
  22 #define SYSRQ_ENABLE_LOG        0x0002
  23 #define SYSRQ_ENABLE_KEYBOARD   0x0004
  24 #define SYSRQ_ENABLE_DUMP       0x0008
  25 #define SYSRQ_ENABLE_SYNC       0x0010
  26 #define SYSRQ_ENABLE_REMOUNT    0x0020
  27 #define SYSRQ_ENABLE_SIGNAL     0x0040
  28 #define SYSRQ_ENABLE_BOOT       0x0080
  29 #define SYSRQ_ENABLE_RTNICE     0x0100
  30
  31 #define SYSRQ_DISABLE_USERSPACE 0x00010000
  32
  33 struct sysrq_key_op {
  34         void (*handler)(int);
  35         char *help_msg;
  36         char *action_msg;
  37         int enable_mask;
  38 };
  39
  40 #ifdef CONFIG_MAGIC_SYSRQ
  41
  42 /* Generic SysRq interface -- you may call it from any device driver, supplying
  43  * ASCII code of the key, pointer to registers and kbd/tty structs (if they
  44  * are available -- else NULL's).
  45  */
  46
  47 #define SYSRQ_FROM_KERNEL       0x0001
  48 #define SYSRQ_FROM_PROC         0x0002
  49 #define SYSRQ_FROM_SYNTHETIC    0x0004
  50
  51 void handle_sysrq(int key);
  52 void __handle_sysrq(int key, unsigned int from);
  53 int register_sysrq_key(int key, struct sysrq_key_op *op);
  54 int unregister_sysrq_key(int key, struct sysrq_key_op *op);
  55 struct sysrq_key_op *__sysrq_get_key_op(int key);
  56
  57 int sysrq_toggle_support(int enable_mask);
  58
  59 #else
  60
  61 static inline void handle_sysrq(int key)
  62 {
  63 }
  64
  65 static inline void __handle_sysrq(int key, bool check_mask)
  66 {
  67 }
  68
  69 static inline int register_sysrq_key(int key, struct sysrq_key_op *op)
  70 {
  71         return -EINVAL;
  72 }
  73
  74 static inline int unregister_sysrq_key(int key, struct sysrq_key_op *op)
  75 {
  76         return -EINVAL;
  77 }
  78
  79 #endif
  80
  81 #endif /* _LINUX_SYSRQ_H */