[linux-2.6-block.git] / include / uapi / linux / userfaultfd.h

/*
 *  include/linux/userfaultfd.h
 *
 *  Copyright (C) 2007  Davide Libenzi <davidel@xmailserver.org>
 *  Copyright (C) 2015  Red Hat, Inc.
 *
 */

#ifndef _LINUX_USERFAULTFD_H
#define _LINUX_USERFAULTFD_H

#include <linux/types.h>

#define UFFD_API ((__u64)0xAA)
/* FIXME: add "|UFFD_FEATURE_WP" to UFFD_API_FEATURES after implementing it */
#define UFFD_API_FEATURES (UFFD_FEATURE_WRITE_BIT)
#define UFFD_API_IOCTLS				\
	((__u64)1 << _UFFDIO_REGISTER |		\
	 (__u64)1 << _UFFDIO_UNREGISTER |	\
	 (__u64)1 << _UFFDIO_API)
#define UFFD_API_RANGE_IOCTLS			\
	((__u64)1 << _UFFDIO_WAKE)

/*
 * Valid ioctl command number range with this API is from 0x00 to
 * 0x3F.  UFFDIO_API is the fixed number, everything else can be
 * changed by implementing a different UFFD_API. If sticking to the
 * same UFFD_API more ioctl can be added and userland will be aware of
 * which ioctl the running kernel implements through the ioctl command
 * bitmask written by the UFFDIO_API.
 */
#define _UFFDIO_REGISTER		(0x00)
#define _UFFDIO_UNREGISTER		(0x01)
#define _UFFDIO_WAKE			(0x02)
#define _UFFDIO_API			(0x3F)

/* userfaultfd ioctl ids */
#define UFFDIO 0xAA
#define UFFDIO_API		_IOWR(UFFDIO, _UFFDIO_API,	\
				      struct uffdio_api)
#define UFFDIO_REGISTER		_IOWR(UFFDIO, _UFFDIO_REGISTER, \
				      struct uffdio_register)
#define UFFDIO_UNREGISTER	_IOR(UFFDIO, _UFFDIO_UNREGISTER,	\
				     struct uffdio_range)
#define UFFDIO_WAKE		_IOR(UFFDIO, _UFFDIO_WAKE,	\
				     struct uffdio_range)

/*
 * Valid bits below PAGE_SHIFT in the userfault address read through
 * the read() syscall.
 */
#define UFFD_BIT_WRITE	(1<<0)	/* this was a write fault, MISSING or WP */
#define UFFD_BIT_WP	(1<<1)	/* handle_userfault() reason VM_UFFD_WP */
#define UFFD_BITS	2	/* two above bits used for UFFD_BIT_* mask */

/*
 * Features reported in uffdio_api.features field
 */
#define UFFD_FEATURE_WRITE_BIT	(1<<0) /* Corresponds to UFFD_BIT_WRITE */
#define UFFD_FEATURE_WP_BIT	(1<<1) /* Corresponds to UFFD_BIT_WP */

struct uffdio_api {
	/* userland asks for an API number */
	__u64 api;

	/* kernel answers below with the available features for the API */
	__u64 features;
	__u64 ioctls;
};

struct uffdio_range {
	__u64 start;
	__u64 len;
};

struct uffdio_register {
	struct uffdio_range range;
#define UFFDIO_REGISTER_MODE_MISSING	((__u64)1<<0)
#define UFFDIO_REGISTER_MODE_WP		((__u64)1<<1)
	__u64 mode;

	/*
	 * kernel answers which ioctl commands are available for the
	 * range, keep at the end as the last 8 bytes aren't read.
	 */
	__u64 ioctls;
};

#endif /* _LINUX_USERFAULTFD_H */
Commit	Line	Data
1038628d AA	1	/*
	2	* include/linux/userfaultfd.h
	3	*
	4	* Copyright (C) 2007 Davide Libenzi <davidel@xmailserver.org>
	5	* Copyright (C) 2015 Red Hat, Inc.
	6	*
	7	*/
	8
	9	#ifndef _LINUX_USERFAULTFD_H
	10	#define _LINUX_USERFAULTFD_H
	11
	12	#include <linux/types.h>
	13
	14	#define UFFD_API ((__u64)0xAA)
3f602d27 PE	15	/* FIXME: add "\|UFFD_FEATURE_WP" to UFFD_API_FEATURES after implementing it */
3f602d27 PE	16	#define UFFD_API_FEATURES (UFFD_FEATURE_WRITE_BIT)
1038628d AA	17	#define UFFD_API_IOCTLS \
	18	((__u64)1 << _UFFDIO_REGISTER \| \
	19	(__u64)1 << _UFFDIO_UNREGISTER \| \
	20	(__u64)1 << _UFFDIO_API)
	21	#define UFFD_API_RANGE_IOCTLS \
	22	((__u64)1 << _UFFDIO_WAKE)
	23
	24	/*
	25	* Valid ioctl command number range with this API is from 0x00 to
	26	* 0x3F. UFFDIO_API is the fixed number, everything else can be
	27	* changed by implementing a different UFFD_API. If sticking to the
	28	* same UFFD_API more ioctl can be added and userland will be aware of
	29	* which ioctl the running kernel implements through the ioctl command
	30	* bitmask written by the UFFDIO_API.
	31	*/
	32	#define _UFFDIO_REGISTER (0x00)
	33	#define _UFFDIO_UNREGISTER (0x01)
	34	#define _UFFDIO_WAKE (0x02)
	35	#define _UFFDIO_API (0x3F)
	36
	37	/* userfaultfd ioctl ids */
	38	#define UFFDIO 0xAA
	39	#define UFFDIO_API _IOWR(UFFDIO, _UFFDIO_API, \
	40	struct uffdio_api)
	41	#define UFFDIO_REGISTER _IOWR(UFFDIO, _UFFDIO_REGISTER, \
	42	struct uffdio_register)
	43	#define UFFDIO_UNREGISTER _IOR(UFFDIO, _UFFDIO_UNREGISTER, \
	44	struct uffdio_range)
	45	#define UFFDIO_WAKE _IOR(UFFDIO, _UFFDIO_WAKE, \
	46	struct uffdio_range)
	47
	48	/*
	49	* Valid bits below PAGE_SHIFT in the userfault address read through
	50	* the read() syscall.
	51	*/
	52	#define UFFD_BIT_WRITE (1<<0) /* this was a write fault, MISSING or WP */
	53	#define UFFD_BIT_WP (1<<1) /* handle_userfault() reason VM_UFFD_WP */
	54	#define UFFD_BITS 2 /* two above bits used for UFFD_BIT_* mask */
	55
3f602d27 PE	56	/*
	57	* Features reported in uffdio_api.features field
	58	*/
	59	#define UFFD_FEATURE_WRITE_BIT (1<<0) /* Corresponds to UFFD_BIT_WRITE */
	60	#define UFFD_FEATURE_WP_BIT (1<<1) /* Corresponds to UFFD_BIT_WP */
	61
1038628d AA	62	struct uffdio_api {
	63	/* userland asks for an API number */
	64	__u64 api;
	65
	66	/* kernel answers below with the available features for the API */
3f602d27	67	__u64 features;
1038628d AA	68	__u64 ioctls;
	69	};
	70
	71	struct uffdio_range {
	72	__u64 start;
	73	__u64 len;
	74	};
	75
	76	struct uffdio_register {
	77	struct uffdio_range range;
	78	#define UFFDIO_REGISTER_MODE_MISSING ((__u64)1<<0)
	79	#define UFFDIO_REGISTER_MODE_WP ((__u64)1<<1)
	80	__u64 mode;
	81
	82	/*
	83	* kernel answers which ioctl commands are available for the
	84	* range, keep at the end as the last 8 bytes aren't read.
	85	*/
	86	__u64 ioctls;
	87	};
	88
	89	#endif /* _LINUX_USERFAULTFD_H */