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 struct pt_regs;
  18 struct tty_struct;
  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 struct sysrq_key_op {
  32         void (*handler)(int, struct tty_struct *);
  33         char *help_msg;
  34         char *action_msg;
  35         int enable_mask;
  36 };
  37
  38 #ifdef CONFIG_MAGIC_SYSRQ
  39
  40 extern int sysrq_on(void);
  41
  42 /*
  43  * Do not use this one directly:
  44  */
  45 extern int __sysrq_enabled;
  46
  47 /* Generic SysRq interface -- you may call it from any device driver, supplying
  48  * ASCII code of the key, pointer to registers and kbd/tty structs (if they
  49  * are available -- else NULL's).
  50  */
  51
  52 void handle_sysrq(int key, struct tty_struct *tty);
  53 void __handle_sysrq(int key, struct tty_struct *tty, int check_mask);
  54 int register_sysrq_key(int key, struct sysrq_key_op *op);
  55 int unregister_sysrq_key(int key, struct sysrq_key_op *op);
  56 struct sysrq_key_op *__sysrq_get_key_op(int key);
  57
  58 #else
  59
  60 static inline int sysrq_on(void)
  61 {
  62         return 0;
  63 }
  64 static inline int __reterr(void)
  65 {
  66         return -EINVAL;
  67 }
  68 static inline void handle_sysrq(int key, struct tty_struct *tty)
  69 {
  70 }
  71
  72 #define register_sysrq_key(ig,nore) __reterr()
  73 #define unregister_sysrq_key(ig,nore) __reterr()
  74
  75 #endif
  76
  77 #endif /* _LINUX_SYSRQ_H */