[mirror_ubuntu-bionic-kernel.git] / include / linux / sysrq.h

/* SPDX-License-Identifier: GPL-2.0 */
/* -*- linux-c -*-
 *
 *	$Id: sysrq.h,v 1.3 1997/07/17 11:54:33 mj Exp $
 *
 *	Linux Magic System Request Key Hacks
 *
 *	(c) 1997 Martin Mares <mj@atrey.karlin.mff.cuni.cz>
 *
 *	(c) 2000 Crutcher Dunnavant <crutcher+kernel@datastacks.com>
 *	overhauled to use key registration
 *	based upon discusions in irc://irc.openprojects.net/#kernelnewbies
 */

#ifndef _LINUX_SYSRQ_H
#define _LINUX_SYSRQ_H

#include <linux/errno.h>
#include <linux/types.h>

/* Possible values of bitmask for enabling sysrq functions */
/* 0x0001 is reserved for enable everything */
#define SYSRQ_ENABLE_LOG	0x0002
#define SYSRQ_ENABLE_KEYBOARD	0x0004
#define SYSRQ_ENABLE_DUMP	0x0008
#define SYSRQ_ENABLE_SYNC	0x0010
#define SYSRQ_ENABLE_REMOUNT	0x0020
#define SYSRQ_ENABLE_SIGNAL	0x0040
#define SYSRQ_ENABLE_BOOT	0x0080
#define SYSRQ_ENABLE_RTNICE	0x0100

#define SYSRQ_DISABLE_USERSPACE	0x00010000

struct sysrq_key_op {
	void (*handler)(int);
	char *help_msg;
	char *action_msg;
	int enable_mask;
};

#ifdef CONFIG_MAGIC_SYSRQ

/* Generic SysRq interface -- you may call it from any device driver, supplying
 * ASCII code of the key, pointer to registers and kbd/tty structs (if they
 * are available -- else NULL's).
 */

#define SYSRQ_FROM_KERNEL	0x0001
#define SYSRQ_FROM_PROC		0x0002
#define SYSRQ_FROM_SYNTHETIC	0x0004

void handle_sysrq(int key);
void __handle_sysrq(int key, unsigned int from);
int register_sysrq_key(int key, struct sysrq_key_op *op);
int unregister_sysrq_key(int key, struct sysrq_key_op *op);
struct sysrq_key_op *__sysrq_get_key_op(int key);

int sysrq_toggle_support(int enable_mask);

#else

static inline void handle_sysrq(int key)
{
}

static inline void __handle_sysrq(int key, bool check_mask)
{
}

static inline int register_sysrq_key(int key, struct sysrq_key_op *op)
{
	return -EINVAL;
}

static inline int unregister_sysrq_key(int key, struct sysrq_key_op *op)
{
	return -EINVAL;
}

#endif

#endif /* _LINUX_SYSRQ_H */
Commit	Line	Data
	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	#define SYSRQ_DISABLE_USERSPACE 0x00010000
	33
	34	struct sysrq_key_op {
	35	void (*handler)(int);
	36	char *help_msg;
	37	char *action_msg;
	38	int enable_mask;
	39	};
	40
	41	#ifdef CONFIG_MAGIC_SYSRQ
	42
	43	/* Generic SysRq interface -- you may call it from any device driver, supplying
	44	* ASCII code of the key, pointer to registers and kbd/tty structs (if they
	45	* are available -- else NULL's).
	46	*/
	47
	48	#define SYSRQ_FROM_KERNEL 0x0001
	49	#define SYSRQ_FROM_PROC 0x0002
	50	#define SYSRQ_FROM_SYNTHETIC 0x0004
	51
	52	void handle_sysrq(int key);
	53	void __handle_sysrq(int key, unsigned int from);
	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	int sysrq_toggle_support(int enable_mask);
	59
	60	#else
	61
	62	static inline void handle_sysrq(int key)
	63	{
	64	}
	65
	66	static inline void __handle_sysrq(int key, bool check_mask)
	67	{
	68	}
	69
	70	static inline int register_sysrq_key(int key, struct sysrq_key_op *op)
	71	{
	72	return -EINVAL;
	73	}
	74
	75	static inline int unregister_sysrq_key(int key, struct sysrq_key_op *op)
	76	{
	77	return -EINVAL;
	78	}
	79
	80	#endif
	81
	82	#endif /* _LINUX_SYSRQ_H */