[mirror_ubuntu-bionic-kernel.git] / include / xen / gntdev.h

/******************************************************************************
 * gntdev.h
 * 
 * Interface to /dev/xen/gntdev.
 * 
 * Copyright (c) 2007, D G Murray
 * 
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License version 2
 * as published by the Free Software Foundation; or, when distributed
 * separately from the Linux kernel or incorporated into other
 * software packages, subject to the following license:
 * 
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this source file (the "Software"), to deal in the Software without
 * restriction, including without limitation the rights to use, copy, modify,
 * merge, publish, distribute, sublicense, and/or sell copies of the Software,
 * and to permit persons to whom the Software is furnished to do so, subject to
 * the following conditions:
 * 
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 * 
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
 * IN THE SOFTWARE.
 */

#ifndef __LINUX_PUBLIC_GNTDEV_H__
#define __LINUX_PUBLIC_GNTDEV_H__

struct ioctl_gntdev_grant_ref {
	/* The domain ID of the grant to be mapped. */
	uint32_t domid;
	/* The grant reference of the grant to be mapped. */
	uint32_t ref;
};

/*
 * Inserts the grant references into the mapping table of an instance
 * of gntdev. N.B. This does not perform the mapping, which is deferred
 * until mmap() is called with @index as the offset.
 */
#define IOCTL_GNTDEV_MAP_GRANT_REF \
_IOC(_IOC_NONE, 'G', 0, sizeof(struct ioctl_gntdev_map_grant_ref))
struct ioctl_gntdev_map_grant_ref {
	/* IN parameters */
	/* The number of grants to be mapped. */
	uint32_t count;
	uint32_t pad;
	/* OUT parameters */
	/* The offset to be used on a subsequent call to mmap(). */
	uint64_t index;
	/* Variable IN parameter. */
	/* Array of grant references, of size @count. */
	struct ioctl_gntdev_grant_ref refs[1];
};

/*
 * Removes the grant references from the mapping table of an instance of
 * of gntdev. N.B. munmap() must be called on the relevant virtual address(es)
 * before this ioctl is called, or an error will result.
 */
#define IOCTL_GNTDEV_UNMAP_GRANT_REF \
_IOC(_IOC_NONE, 'G', 1, sizeof(struct ioctl_gntdev_unmap_grant_ref))
struct ioctl_gntdev_unmap_grant_ref {
	/* IN parameters */
	/* The offset was returned by the corresponding map operation. */
	uint64_t index;
	/* The number of pages to be unmapped. */
	uint32_t count;
	uint32_t pad;
};

/*
 * Returns the offset in the driver's address space that corresponds
 * to @vaddr. This can be used to perform a munmap(), followed by an
 * UNMAP_GRANT_REF ioctl, where no state about the offset is retained by
 * the caller. The number of pages that were allocated at the same time as
 * @vaddr is returned in @count.
 *
 * N.B. Where more than one page has been mapped into a contiguous range, the
 *      supplied @vaddr must correspond to the start of the range; otherwise
 *      an error will result. It is only possible to munmap() the entire
 *      contiguously-allocated range at once, and not any subrange thereof.
 */
#define IOCTL_GNTDEV_GET_OFFSET_FOR_VADDR \
_IOC(_IOC_NONE, 'G', 2, sizeof(struct ioctl_gntdev_get_offset_for_vaddr))
struct ioctl_gntdev_get_offset_for_vaddr {
	/* IN parameters */
	/* The virtual address of the first mapped page in a range. */
	uint64_t vaddr;
	/* OUT parameters */
	/* The offset that was used in the initial mmap() operation. */
	uint64_t offset;
	/* The number of pages mapped in the VM area that begins at @vaddr. */
	uint32_t count;
	uint32_t pad;
};

/*
 * Sets the maximum number of grants that may mapped at once by this gntdev
 * instance.
 *
 * N.B. This must be called before any other ioctl is performed on the device.
 */
#define IOCTL_GNTDEV_SET_MAX_GRANTS \
_IOC(_IOC_NONE, 'G', 3, sizeof(struct ioctl_gntdev_set_max_grants))
struct ioctl_gntdev_set_max_grants {
	/* IN parameter */
	/* The maximum number of grants that may be mapped at once. */
	uint32_t count;
};

/*
 * Sets up an unmap notification within the page, so that the other side can do
 * cleanup if this side crashes. Required to implement cross-domain robust
 * mutexes or close notification on communication channels.
 *
 * Each mapped page only supports one notification; multiple calls referring to
 * the same page overwrite the previous notification. You must clear the
 * notification prior to the IOCTL_GNTALLOC_DEALLOC_GREF if you do not want it
 * to occur.
 */
#define IOCTL_GNTDEV_SET_UNMAP_NOTIFY \
_IOC(_IOC_NONE, 'G', 7, sizeof(struct ioctl_gntdev_unmap_notify))
struct ioctl_gntdev_unmap_notify {
	/* IN parameters */
	/* Offset in the file descriptor for a byte within the page (same as
	 * used in mmap). If using UNMAP_NOTIFY_CLEAR_BYTE, this is the byte to
	 * be cleared. Otherwise, it can be any byte in the page whose
	 * notification we are adjusting.
	 */
	uint64_t index;
	/* Action(s) to take on unmap */
	uint32_t action;
	/* Event channel to notify */
	uint32_t event_channel_port;
};

/* Clear (set to zero) the byte specified by index */
#define UNMAP_NOTIFY_CLEAR_BYTE 0x1
/* Send an interrupt on the indicated event channel */
#define UNMAP_NOTIFY_SEND_EVENT 0x2

#endif /* __LINUX_PUBLIC_GNTDEV_H__ */
Commit	Line	Data
ab31523c GH	1	/******************************************************************************
	2	* gntdev.h
	3	*
	4	* Interface to /dev/xen/gntdev.
	5	*
	6	* Copyright (c) 2007, D G Murray
	7	*
	8	* This program is free software; you can redistribute it and/or
	9	* modify it under the terms of the GNU General Public License version 2
	10	* as published by the Free Software Foundation; or, when distributed
	11	* separately from the Linux kernel or incorporated into other
	12	* software packages, subject to the following license:
	13	*
	14	* Permission is hereby granted, free of charge, to any person obtaining a copy
	15	* of this source file (the "Software"), to deal in the Software without
	16	* restriction, including without limitation the rights to use, copy, modify,
	17	* merge, publish, distribute, sublicense, and/or sell copies of the Software,
	18	* and to permit persons to whom the Software is furnished to do so, subject to
	19	* the following conditions:
	20	*
	21	* The above copyright notice and this permission notice shall be included in
	22	* all copies or substantial portions of the Software.
	23	*
	24	* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
	25	* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
	26	* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
	27	* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
	28	* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
	29	* FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
	30	* IN THE SOFTWARE.
	31	*/
	32
	33	#ifndef __LINUX_PUBLIC_GNTDEV_H__
	34	#define __LINUX_PUBLIC_GNTDEV_H__
	35
	36	struct ioctl_gntdev_grant_ref {
	37	/* The domain ID of the grant to be mapped. */
	38	uint32_t domid;
	39	/* The grant reference of the grant to be mapped. */
	40	uint32_t ref;
	41	};
	42
	43	/*
	44	* Inserts the grant references into the mapping table of an instance
	45	* of gntdev. N.B. This does not perform the mapping, which is deferred
	46	* until mmap() is called with @index as the offset.
	47	*/
	48	#define IOCTL_GNTDEV_MAP_GRANT_REF \
	49	_IOC(_IOC_NONE, 'G', 0, sizeof(struct ioctl_gntdev_map_grant_ref))
	50	struct ioctl_gntdev_map_grant_ref {
	51	/* IN parameters */
	52	/* The number of grants to be mapped. */
	53	uint32_t count;
	54	uint32_t pad;
	55	/* OUT parameters */
	56	/* The offset to be used on a subsequent call to mmap(). */
	57	uint64_t index;
	58	/* Variable IN parameter. */
	59	/* Array of grant references, of size @count. */
	60	struct ioctl_gntdev_grant_ref refs[1];
	61	};
	62
	63	/*
	64	* Removes the grant references from the mapping table of an instance of
65	* of gntdev. N.B. munmap() must be called on the relevant virtual address(es)
66	* before this ioctl is called, or an error will result.
67	*/
68	#define IOCTL_GNTDEV_UNMAP_GRANT_REF \
69	_IOC(_IOC_NONE, 'G', 1, sizeof(struct ioctl_gntdev_unmap_grant_ref))
70	struct ioctl_gntdev_unmap_grant_ref {
71	/* IN parameters */
72	/* The offset was returned by the corresponding map operation. */
73	uint64_t index;
74	/* The number of pages to be unmapped. */
75	uint32_t count;
76	uint32_t pad;
77	};
78
79	/*
80	* Returns the offset in the driver's address space that corresponds
81	* to @vaddr. This can be used to perform a munmap(), followed by an
82	* UNMAP_GRANT_REF ioctl, where no state about the offset is retained by
83	* the caller. The number of pages that were allocated at the same time as
84	* @vaddr is returned in @count.
85	*
86	* N.B. Where more than one page has been mapped into a contiguous range, the
87	* supplied @vaddr must correspond to the start of the range; otherwise
88	* an error will result. It is only possible to munmap() the entire
89	* contiguously-allocated range at once, and not any subrange thereof.
90	*/
91	#define IOCTL_GNTDEV_GET_OFFSET_FOR_VADDR \
92	_IOC(_IOC_NONE, 'G', 2, sizeof(struct ioctl_gntdev_get_offset_for_vaddr))
93	struct ioctl_gntdev_get_offset_for_vaddr {
94	/* IN parameters */
95	/* The virtual address of the first mapped page in a range. */
96	uint64_t vaddr;
97	/* OUT parameters */
98	/* The offset that was used in the initial mmap() operation. */
99	uint64_t offset;
100	/* The number of pages mapped in the VM area that begins at @vaddr. */
101	uint32_t count;
102	uint32_t pad;
103	};
104
105	/*
106	* Sets the maximum number of grants that may mapped at once by this gntdev
107	* instance.
108	*
109	* N.B. This must be called before any other ioctl is performed on the device.
110	*/
111	#define IOCTL_GNTDEV_SET_MAX_GRANTS \
112	_IOC(_IOC_NONE, 'G', 3, sizeof(struct ioctl_gntdev_set_max_grants))
113	struct ioctl_gntdev_set_max_grants {
114	/* IN parameter */
115	/* The maximum number of grants that may be mapped at once. */
116	uint32_t count;
117	};
118
bdc612dc DDG	119	/*
	120	* Sets up an unmap notification within the page, so that the other side can do
	121	* cleanup if this side crashes. Required to implement cross-domain robust
	122	* mutexes or close notification on communication channels.
	123	*
	124	* Each mapped page only supports one notification; multiple calls referring to
	125	* the same page overwrite the previous notification. You must clear the
	126	* notification prior to the IOCTL_GNTALLOC_DEALLOC_GREF if you do not want it
	127	* to occur.
	128	*/
	129	#define IOCTL_GNTDEV_SET_UNMAP_NOTIFY \
	130	_IOC(_IOC_NONE, 'G', 7, sizeof(struct ioctl_gntdev_unmap_notify))
	131	struct ioctl_gntdev_unmap_notify {
	132	/* IN parameters */
	133	/* Offset in the file descriptor for a byte within the page (same as
	134	* used in mmap). If using UNMAP_NOTIFY_CLEAR_BYTE, this is the byte to
	135	* be cleared. Otherwise, it can be any byte in the page whose
	136	* notification we are adjusting.
	137	*/
	138	uint64_t index;
	139	/* Action(s) to take on unmap */
	140	uint32_t action;
	141	/* Event channel to notify */
	142	uint32_t event_channel_port;
	143	};
	144
	145	/* Clear (set to zero) the byte specified by index */
	146	#define UNMAP_NOTIFY_CLEAR_BYTE 0x1
	147	/* Send an interrupt on the indicated event channel */
	148	#define UNMAP_NOTIFY_SEND_EVENT 0x2
	149
ab31523c	150	#endif /* __LINUX_PUBLIC_GNTDEV_H__ */