xref: /linux-6.15/include/linux/sysrq.h (revision 97f5f0cd)
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 <[email protected]>
8  *
9  *	(c) 2000 Crutcher Dunnavant <[email protected]>
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 
19 struct pt_regs;
20 struct tty_struct;
21 
22 /* Possible values of bitmask for enabling sysrq functions */
23 /* 0x0001 is reserved for enable everything */
24 #define SYSRQ_ENABLE_LOG	0x0002
25 #define SYSRQ_ENABLE_KEYBOARD	0x0004
26 #define SYSRQ_ENABLE_DUMP	0x0008
27 #define SYSRQ_ENABLE_SYNC	0x0010
28 #define SYSRQ_ENABLE_REMOUNT	0x0020
29 #define SYSRQ_ENABLE_SIGNAL	0x0040
30 #define SYSRQ_ENABLE_BOOT	0x0080
31 #define SYSRQ_ENABLE_RTNICE	0x0100
32 
33 struct sysrq_key_op {
34 	void (*handler)(int, struct tty_struct *);
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 void handle_sysrq(int key, struct tty_struct *tty);
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, struct tty_struct *tty)
57 {
58 }
59 
60 static inline int register_sysrq_key(int key, struct sysrq_key_op *op)
61 {
62 	return -EINVAL;
63 }
64 
65 static inline int unregister_sysrq_key(int key, struct sysrq_key_op *op)
66 {
67 	return -EINVAL;
68 }
69 
70 #endif
71 
72 #endif /* _LINUX_SYSRQ_H */
73