xref: /linux/include/xen/interface/io/fbif.h (revision f7511d5f66f01fc451747b24e79f3ada7a3af9af)
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 #define XENFB_OUT_EVENT_SIZE 40
53 
54 union xenfb_out_event {
55 	uint8_t type;
56 	struct xenfb_update update;
57 	char pad[XENFB_OUT_EVENT_SIZE];
58 };
59 
60 /* In events (backend -> frontend) */
61 
62 /*
63  * Frontends should ignore unknown in events.
64  * No in events currently defined.
65  */
66 
67 #define XENFB_IN_EVENT_SIZE 40
68 
69 union xenfb_in_event {
70 	uint8_t type;
71 	char pad[XENFB_IN_EVENT_SIZE];
72 };
73 
74 /* shared page */
75 
76 #define XENFB_IN_RING_SIZE 1024
77 #define XENFB_IN_RING_LEN (XENFB_IN_RING_SIZE / XENFB_IN_EVENT_SIZE)
78 #define XENFB_IN_RING_OFFS 1024
79 #define XENFB_IN_RING(page) \
80 	((union xenfb_in_event *)((char *)(page) + XENFB_IN_RING_OFFS))
81 #define XENFB_IN_RING_REF(page, idx) \
82 	(XENFB_IN_RING((page))[(idx) % XENFB_IN_RING_LEN])
83 
84 #define XENFB_OUT_RING_SIZE 2048
85 #define XENFB_OUT_RING_LEN (XENFB_OUT_RING_SIZE / XENFB_OUT_EVENT_SIZE)
86 #define XENFB_OUT_RING_OFFS (XENFB_IN_RING_OFFS + XENFB_IN_RING_SIZE)
87 #define XENFB_OUT_RING(page) \
88 	((union xenfb_out_event *)((char *)(page) + XENFB_OUT_RING_OFFS))
89 #define XENFB_OUT_RING_REF(page, idx) \
90 	(XENFB_OUT_RING((page))[(idx) % XENFB_OUT_RING_LEN])
91 
92 struct xenfb_page {
93 	uint32_t in_cons, in_prod;
94 	uint32_t out_cons, out_prod;
95 
96 	int32_t width;          /* width of the framebuffer (in pixels) */
97 	int32_t height;         /* height of the framebuffer (in pixels) */
98 	uint32_t line_length;   /* length of a row of pixels (in bytes) */
99 	uint32_t mem_length;    /* length of the framebuffer (in bytes) */
100 	uint8_t depth;          /* depth of a pixel (in bits) */
101 
102 	/*
103 	 * Framebuffer page directory
104 	 *
105 	 * Each directory page holds PAGE_SIZE / sizeof(*pd)
106 	 * framebuffer pages, and can thus map up to PAGE_SIZE *
107 	 * PAGE_SIZE / sizeof(*pd) bytes.  With PAGE_SIZE == 4096 and
108 	 * sizeof(unsigned long) == 4, that's 4 Megs.  Two directory
109 	 * pages should be enough for a while.
110 	 */
111 	unsigned long pd[2];
112 };
113 
114 /*
115  * Wart: xenkbd needs to know resolution.  Put it here until a better
116  * solution is found, but don't leak it to the backend.
117  */
118 #ifdef __KERNEL__
119 #define XENFB_WIDTH 800
120 #define XENFB_HEIGHT 600
121 #define XENFB_DEPTH 32
122 #endif
123 
124 #endif
125