1 /* SPDX-License-Identifier: GPL-2.0 */ 2 /* -*- linux-c -*- 3 * 4 * $Id: sysrq.h,v 1.3 1997/07/17 11:54:33 mj Exp $ 5 * 6 * Linux Magic System Request Key Hacks 7 * 8 * (c) 1997 Martin Mares <mj@atrey.karlin.mff.cuni.cz> 9 * 10 * (c) 2000 Crutcher Dunnavant <crutcher+kernel@datastacks.com> 11 * overhauled to use key registration 12 * based upon discusions in irc://irc.openprojects.net/#kernelnewbies 13 */ 14 15 #ifndef _LINUX_SYSRQ_H 16 #define _LINUX_SYSRQ_H 17 18 #include <linux/errno.h> 19 #include <linux/types.h> 20 21 /* Possible values of bitmask for enabling sysrq functions */ 22 /* 0x0001 is reserved for enable everything */ 23 #define SYSRQ_ENABLE_LOG 0x0002 24 #define SYSRQ_ENABLE_KEYBOARD 0x0004 25 #define SYSRQ_ENABLE_DUMP 0x0008 26 #define SYSRQ_ENABLE_SYNC 0x0010 27 #define SYSRQ_ENABLE_REMOUNT 0x0020 28 #define SYSRQ_ENABLE_SIGNAL 0x0040 29 #define SYSRQ_ENABLE_BOOT 0x0080 30 #define SYSRQ_ENABLE_RTNICE 0x0100 31 32 struct sysrq_key_op { 33 void (*handler)(int); 34 char *help_msg; 35 char *action_msg; 36 int enable_mask; 37 }; 38 39 #ifdef CONFIG_MAGIC_SYSRQ 40 41 /* Generic SysRq interface -- you may call it from any device driver, supplying 42 * ASCII code of the key, pointer to registers and kbd/tty structs (if they 43 * are available -- else NULL's). 44 */ 45 46 void handle_sysrq(int key); 47 void __handle_sysrq(int key, bool check_mask); 48 int register_sysrq_key(int key, struct sysrq_key_op *op); 49 int unregister_sysrq_key(int key, struct sysrq_key_op *op); 50 struct sysrq_key_op *__sysrq_get_key_op(int key); 51 52 int sysrq_toggle_support(int enable_mask); 53 54 #else 55 56 static inline void handle_sysrq(int key) 57 { 58 } 59 60 static inline void __handle_sysrq(int key, bool check_mask) 61 { 62 } 63 64 static inline int register_sysrq_key(int key, struct sysrq_key_op *op) 65 { 66 return -EINVAL; 67 } 68 69 static inline int unregister_sysrq_key(int key, struct sysrq_key_op *op) 70 { 71 return -EINVAL; 72 } 73 74 #endif 75 76 #endif /* _LINUX_SYSRQ_H */ 77