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