xref: /openbmc/linux/include/xen/interface/io/fbif.h (revision f3539c12)
1 /*
2  * fbif.h -- Xen virtual frame buffer device
3  *
4  * Permission is hereby granted, free of charge, to any person obtaining a copy
5  * of this software and associated documentation files (the "Software"), to
6  * deal in the Software without restriction, including without limitation the
7  * rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
8  * sell copies of the Software, and to permit persons to whom the Software is
9  * furnished to do so, subject to the following conditions:
10  *
11  * The above copyright notice and this permission notice shall be included in
12  * all copies or substantial portions of the Software.
13  *
14  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
15  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
16  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
17  * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
18  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
19  * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
20  * DEALINGS IN THE SOFTWARE.
21  *
22  * Copyright (C) 2005 Anthony Liguori <aliguori@us.ibm.com>
23  * Copyright (C) 2006 Red Hat, Inc., Markus Armbruster <armbru@redhat.com>
24  */
25 
26 #ifndef __XEN_PUBLIC_IO_FBIF_H__
27 #define __XEN_PUBLIC_IO_FBIF_H__
28 
29 /* Out events (frontend -> backend) */
30 
31 /*
32  * Out events may be sent only when requested by backend, and receipt
33  * of an unknown out event is an error.
34  */
35 
36 /* Event type 1 currently not used */
37 /*
38  * Framebuffer update notification event
39  * Capable frontend sets feature-update in xenstore.
40  * Backend requests it by setting request-update in xenstore.
41  */
42 #define XENFB_TYPE_UPDATE 2
43 
44 struct xenfb_update {
45 	uint8_t type;		/* XENFB_TYPE_UPDATE */
46 	int32_t x;		/* source x */
47 	int32_t y;		/* source y */
48 	int32_t width;		/* rect width */
49 	int32_t height;		/* rect height */
50 };
51 
52 /*
53  * Framebuffer resize notification event
54  * Capable backend sets feature-resize in xenstore.
55  */
56 #define XENFB_TYPE_RESIZE 3
57 
58 struct xenfb_resize {
59 	uint8_t type;		/* XENFB_TYPE_RESIZE */
60 	int32_t width;		/* width in pixels */
61 	int32_t height;		/* height in pixels */
62 	int32_t stride;		/* stride in bytes */
63 	int32_t depth;		/* depth in bits */
64 	int32_t offset;		/* start offset within framebuffer */
65 };
66 
67 #define XENFB_OUT_EVENT_SIZE 40
68 
69 union xenfb_out_event {
70 	uint8_t type;
71 	struct xenfb_update update;
72 	struct xenfb_resize resize;
73 	char pad[XENFB_OUT_EVENT_SIZE];
74 };
75 
76 /* In events (backend -> frontend) */
77 
78 /*
79  * Frontends should ignore unknown in events.
80  * No in events currently defined.
81  */
82 
83 #define XENFB_IN_EVENT_SIZE 40
84 
85 union xenfb_in_event {
86 	uint8_t type;
87 	char pad[XENFB_IN_EVENT_SIZE];
88 };
89 
90 /* shared page */
91 
92 #define XENFB_IN_RING_SIZE 1024
93 #define XENFB_IN_RING_LEN (XENFB_IN_RING_SIZE / XENFB_IN_EVENT_SIZE)
94 #define XENFB_IN_RING_OFFS 1024
95 #define XENFB_IN_RING(page) \
96 	((union xenfb_in_event *)((char *)(page) + XENFB_IN_RING_OFFS))
97 #define XENFB_IN_RING_REF(page, idx) \
98 	(XENFB_IN_RING((page))[(idx) % XENFB_IN_RING_LEN])
99 
100 #define XENFB_OUT_RING_SIZE 2048
101 #define XENFB_OUT_RING_LEN (XENFB_OUT_RING_SIZE / XENFB_OUT_EVENT_SIZE)
102 #define XENFB_OUT_RING_OFFS (XENFB_IN_RING_OFFS + XENFB_IN_RING_SIZE)
103 #define XENFB_OUT_RING(page) \
104 	((union xenfb_out_event *)((char *)(page) + XENFB_OUT_RING_OFFS))
105 #define XENFB_OUT_RING_REF(page, idx) \
106 	(XENFB_OUT_RING((page))[(idx) % XENFB_OUT_RING_LEN])
107 
108 struct xenfb_page {
109 	uint32_t in_cons, in_prod;
110 	uint32_t out_cons, out_prod;
111 
112 	int32_t width;          /* width of the framebuffer (in pixels) */
113 	int32_t height;         /* height of the framebuffer (in pixels) */
114 	uint32_t line_length;   /* length of a row of pixels (in bytes) */
115 	uint32_t mem_length;    /* length of the framebuffer (in bytes) */
116 	uint8_t depth;          /* depth of a pixel (in bits) */
117 
118 	/*
119 	 * Framebuffer page directory
120 	 *
121 	 * Each directory page holds PAGE_SIZE / sizeof(*pd)
122 	 * framebuffer pages, and can thus map up to PAGE_SIZE *
123 	 * PAGE_SIZE / sizeof(*pd) bytes.  With PAGE_SIZE == 4096 and
124 	 * sizeof(unsigned long) == 4/8, that's 4 Megs 32 bit and 2
125 	 * Megs 64 bit.  256 directories give enough room for a 512
126 	 * Meg framebuffer with a max resolution of 12,800x10,240.
127 	 * Should be enough for a while with room leftover for
128 	 * expansion.
129 	 */
130 	unsigned long pd[256];
131 };
132 
133 /*
134  * Wart: xenkbd needs to know default resolution.  Put it here until a
135  * better solution is found, but don't leak it to the backend.
136  */
137 #ifdef __KERNEL__
138 #define XENFB_WIDTH 800
139 #define XENFB_HEIGHT 600
140 #define XENFB_DEPTH 32
141 #endif
142 
143 #endif
144