1/* SPDX-License-Identifier: MIT */
2/*
3 * fbif.h -- Xen virtual frame buffer device
4 *
5 * Copyright (C) 2005 Anthony Liguori <aliguori@us.ibm.com>
6 * Copyright (C) 2006 Red Hat, Inc., Markus Armbruster <armbru@redhat.com>
7 */
8
9#ifndef __XEN_PUBLIC_IO_FBIF_H__
10#define __XEN_PUBLIC_IO_FBIF_H__
11
12/* Out events (frontend -> backend) */
13
14/*
15 * Out events may be sent only when requested by backend, and receipt
16 * of an unknown out event is an error.
17 */
18
19/* Event type 1 currently not used */
20/*
21 * Framebuffer update notification event
22 * Capable frontend sets feature-update in xenstore.
23 * Backend requests it by setting request-update in xenstore.
24 */
25#define XENFB_TYPE_UPDATE 2
26
27struct xenfb_update {
28 uint8_t type; /* XENFB_TYPE_UPDATE */
29 int32_t x; /* source x */
30 int32_t y; /* source y */
31 int32_t width; /* rect width */
32 int32_t height; /* rect height */
33};
34
35/*
36 * Framebuffer resize notification event
37 * Capable backend sets feature-resize in xenstore.
38 */
39#define XENFB_TYPE_RESIZE 3
40
41struct xenfb_resize {
42 uint8_t type; /* XENFB_TYPE_RESIZE */
43 int32_t width; /* width in pixels */
44 int32_t height; /* height in pixels */
45 int32_t stride; /* stride in bytes */
46 int32_t depth; /* depth in bits */
47 int32_t offset; /* start offset within framebuffer */
48};
49
50#define XENFB_OUT_EVENT_SIZE 40
51
52union xenfb_out_event {
53 uint8_t type;
54 struct xenfb_update update;
55 struct xenfb_resize resize;
56 char pad[XENFB_OUT_EVENT_SIZE];
57};
58
59/* In events (backend -> frontend) */
60
61/*
62 * Frontends should ignore unknown in events.
63 * No in events currently defined.
64 */
65
66#define XENFB_IN_EVENT_SIZE 40
67
68union xenfb_in_event {
69 uint8_t type;
70 char pad[XENFB_IN_EVENT_SIZE];
71};
72
73/* shared page */
74
75#define XENFB_IN_RING_SIZE 1024
76#define XENFB_IN_RING_LEN (XENFB_IN_RING_SIZE / XENFB_IN_EVENT_SIZE)
77#define XENFB_IN_RING_OFFS 1024
78#define XENFB_IN_RING(page) \
79 ((union xenfb_in_event *)((char *)(page) + XENFB_IN_RING_OFFS))
80#define XENFB_IN_RING_REF(page, idx) \
81 (XENFB_IN_RING((page))[(idx) % XENFB_IN_RING_LEN])
82
83#define XENFB_OUT_RING_SIZE 2048
84#define XENFB_OUT_RING_LEN (XENFB_OUT_RING_SIZE / XENFB_OUT_EVENT_SIZE)
85#define XENFB_OUT_RING_OFFS (XENFB_IN_RING_OFFS + XENFB_IN_RING_SIZE)
86#define XENFB_OUT_RING(page) \
87 ((union xenfb_out_event *)((char *)(page) + XENFB_OUT_RING_OFFS))
88#define XENFB_OUT_RING_REF(page, idx) \
89 (XENFB_OUT_RING((page))[(idx) % XENFB_OUT_RING_LEN])
90
91struct xenfb_page {
92 uint32_t in_cons, in_prod;
93 uint32_t out_cons, out_prod;
94
95 int32_t width; /* width of the framebuffer (in pixels) */
96 int32_t height; /* height of the framebuffer (in pixels) */
97 uint32_t line_length; /* length of a row of pixels (in bytes) */
98 uint32_t mem_length; /* length of the framebuffer (in bytes) */
99 uint8_t depth; /* depth of a pixel (in bits) */
100
101 /*
102 * Framebuffer page directory
103 *
104 * Each directory page holds PAGE_SIZE / sizeof(*pd)
105 * framebuffer pages, and can thus map up to PAGE_SIZE *
106 * PAGE_SIZE / sizeof(*pd) bytes. With PAGE_SIZE == 4096 and
107 * sizeof(unsigned long) == 4/8, that's 4 Megs 32 bit and 2
108 * Megs 64 bit. 256 directories give enough room for a 512
109 * Meg framebuffer with a max resolution of 12,800x10,240.
110 * Should be enough for a while with room leftover for
111 * expansion.
112 */
113 unsigned long pd[256];
114};
115
116/*
117 * Wart: xenkbd needs to know default resolution. Put it here until a
118 * better solution is found, but don't leak it to the backend.
119 */
120#ifdef __KERNEL__
121#define XENFB_WIDTH 800
122#define XENFB_HEIGHT 600
123#define XENFB_DEPTH 32
124#endif
125
126#endif
127

source code of linux/include/xen/interface/io/fbif.h