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 __XEN_GNTDEV_H__
34#define __XEN_GNTDEV_H__
35
36#include <sys/ioccom.h>
37
38struct ioctl_gntdev_grant_ref {
39	/* The domain ID of the grant to be mapped. */
40	uint32_t domid;
41	/* The grant reference of the grant to be mapped. */
42	uint32_t ref;
43};
44
45/*
46 * Inserts the grant references into the mapping table of an instance
47 * of gntdev. N.B. This does not perform the mapping, which is deferred
48 * until mmap() is called with @index as the offset.
49 */
50#define IOCTL_GNTDEV_MAP_GRANT_REF				\
51	_IOWR('G', 0, sizeof(struct ioctl_gntdev_map_grant_ref))
52struct ioctl_gntdev_map_grant_ref {
53	/* IN parameters */
54	/* The number of grants to be mapped. */
55	uint32_t count;
56	uint32_t pad;
57	/* OUT parameters */
58	/* The offset to be used on a subsequent call to mmap(). */
59	uint64_t index;
60	/* Variable IN parameter. */
61	/* Array of grant references, of size @count. */
62	struct ioctl_gntdev_grant_ref refs[1];
63};
64
65/*
66 * Removes the grant references from the mapping table of an instance of
67 * of gntdev. N.B. munmap() must be called on the relevant virtual address(es)
68 * before this ioctl is called, or an error will result.
69 */
70#define IOCTL_GNTDEV_UNMAP_GRANT_REF				\
71	_IOW('G', 1, sizeof(struct ioctl_gntdev_unmap_grant_ref))
72struct ioctl_gntdev_unmap_grant_ref {
73	/* IN parameters */
74	/* The offset was returned by the corresponding map operation. */
75	uint64_t index;
76	/* The number of pages to be unmapped. */
77	uint32_t count;
78	uint32_t pad;
79};
80
81/*
82 * Returns the offset in the driver's address space that corresponds
83 * to @vaddr. This can be used to perform a munmap(), followed by an
84 * UNMAP_GRANT_REF ioctl, where no state about the offset is retained by
85 * the caller. The number of pages that were allocated at the same time as
86 * @vaddr is returned in @count.
87 *
88 * N.B. Where more than one page has been mapped into a contiguous range, the
89 *      supplied @vaddr must correspond to the start of the range; otherwise
90 *      an error will result. It is only possible to munmap() the entire
91 *      contiguously-allocated range at once, and not any subrange thereof.
92 */
93#define IOCTL_GNTDEV_GET_OFFSET_FOR_VADDR			\
94	_IOWR('G', 2, sizeof(struct ioctl_gntdev_get_offset_for_vaddr))
95struct ioctl_gntdev_get_offset_for_vaddr {
96	/* IN parameters */
97	/* The virtual address of the first mapped page in a range. */
98	uint64_t vaddr;
99	/* OUT parameters */
100	/* The offset that was used in the initial mmap() operation. */
101	uint64_t offset;
102	/* The number of pages mapped in the VM area that begins at @vaddr. */
103	uint32_t count;
104	uint32_t pad;
105};
106
107/*
108 * Sets the maximum number of grants that may mapped at once by this gntdev
109 * instance.
110 *
111 * N.B. This must be called before any other ioctl is performed on the device.
112 */
113#define IOCTL_GNTDEV_SET_MAX_GRANTS \
114	_IOW('G', 3, sizeof(struct ioctl_gntdev_set_max_grants))
115struct ioctl_gntdev_set_max_grants {
116	/* IN parameter */
117	/* The maximum number of grants that may be mapped at once. */
118	uint32_t count;
119};
120
121#endif /* __XEN_GNTDEV_H__ */
122