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
36struct 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))
50struct 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))
70struct 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))
93struct 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))
113struct 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
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))
131struct 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
150#endif /* __LINUX_PUBLIC_GNTDEV_H__ */
151