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