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 27 struct xenfb_update 28 { 29 uint8_t type; /* XENFB_TYPE_UPDATE */ 30 int32_t x; /* source x */ 31 int32_t y; /* source y */ 32 int32_t width; /* rect width */ 33 int32_t height; /* rect height */ 34 }; 35 36 /* 37 * Framebuffer resize notification event 38 * Capable backend sets feature-resize in xenstore. 39 */ 40 #define XENFB_TYPE_RESIZE 3 41 42 struct xenfb_resize 43 { 44 uint8_t type; /* XENFB_TYPE_RESIZE */ 45 int32_t width; /* width in pixels */ 46 int32_t height; /* height in pixels */ 47 int32_t stride; /* stride in bytes */ 48 int32_t depth; /* depth in bits */ 49 int32_t offset; /* offset of the framebuffer in bytes */ 50 }; 51 52 #define XENFB_OUT_EVENT_SIZE 40 53 54 union xenfb_out_event 55 { 56 uint8_t type; 57 struct xenfb_update update; 58 struct xenfb_resize resize; 59 char pad[XENFB_OUT_EVENT_SIZE]; 60 }; 61 62 /* In events (backend -> frontend) */ 63 64 /* 65 * Frontends should ignore unknown in events. 66 */ 67 68 /* 69 * Framebuffer refresh period advice 70 * Backend sends it to advise the frontend their preferred period of 71 * refresh. Frontends that keep the framebuffer constantly up-to-date 72 * just ignore it. Frontends that use the advice should immediately 73 * refresh the framebuffer (and send an update notification event if 74 * those have been requested), then use the update frequency to guide 75 * their periodical refreshs. 76 */ 77 #define XENFB_TYPE_REFRESH_PERIOD 1 78 #define XENFB_NO_REFRESH 0 79 80 struct xenfb_refresh_period 81 { 82 uint8_t type; /* XENFB_TYPE_UPDATE_PERIOD */ 83 uint32_t period; /* period of refresh, in ms, 84 * XENFB_NO_REFRESH if no refresh is needed */ 85 }; 86 87 #define XENFB_IN_EVENT_SIZE 40 88 89 union xenfb_in_event 90 { 91 uint8_t type; 92 struct xenfb_refresh_period refresh_period; 93 char pad[XENFB_IN_EVENT_SIZE]; 94 }; 95 96 /* shared page */ 97 98 #define XENFB_IN_RING_SIZE 1024 99 #define XENFB_IN_RING_LEN (XENFB_IN_RING_SIZE / XENFB_IN_EVENT_SIZE) 100 #define XENFB_IN_RING_OFFS 1024 101 #define XENFB_IN_RING(page) \ 102 ((union xenfb_in_event *)((char *)(page) + XENFB_IN_RING_OFFS)) 103 #define XENFB_IN_RING_REF(page, idx) \ 104 (XENFB_IN_RING((page))[(idx) % XENFB_IN_RING_LEN]) 105 106 #define XENFB_OUT_RING_SIZE 2048 107 #define XENFB_OUT_RING_LEN (XENFB_OUT_RING_SIZE / XENFB_OUT_EVENT_SIZE) 108 #define XENFB_OUT_RING_OFFS (XENFB_IN_RING_OFFS + XENFB_IN_RING_SIZE) 109 #define XENFB_OUT_RING(page) \ 110 ((union xenfb_out_event *)((char *)(page) + XENFB_OUT_RING_OFFS)) 111 #define XENFB_OUT_RING_REF(page, idx) \ 112 (XENFB_OUT_RING((page))[(idx) % XENFB_OUT_RING_LEN]) 113 114 struct xenfb_page 115 { 116 uint32_t in_cons, in_prod; 117 uint32_t out_cons, out_prod; 118 119 int32_t width; /* the width of the framebuffer (in pixels) */ 120 int32_t height; /* the height of the framebuffer (in pixels) */ 121 uint32_t line_length; /* the length of a row of pixels (in bytes) */ 122 uint32_t mem_length; /* the length of the framebuffer (in bytes) */ 123 uint8_t depth; /* the depth of a pixel (in bits) */ 124 125 /* 126 * Framebuffer page directory 127 * 128 * Each directory page holds PAGE_SIZE / sizeof(*pd) 129 * framebuffer pages, and can thus map up to PAGE_SIZE * 130 * PAGE_SIZE / sizeof(*pd) bytes. With PAGE_SIZE == 4096 and 131 * sizeof(unsigned long) == 4/8, that's 4 Megs 32 bit and 2 Megs 132 * 64 bit. 256 directories give enough room for a 512 Meg 133 * framebuffer with a max resolution of 12,800x10,240. Should 134 * be enough for a while with room leftover for expansion. 135 */ 136 unsigned long pd[256]; 137 }; 138 139 /* 140 * Wart: xenkbd needs to know default resolution. Put it here until a 141 * better solution is found, but don't leak it to the backend. 142 */ 143 #ifdef __KERNEL__ 144 #define XENFB_WIDTH 800 145 #define XENFB_HEIGHT 600 146 #define XENFB_DEPTH 32 147 #endif 148 149 #endif 150 151 /* 152 * Local variables: 153 * mode: C 154 * c-file-style: "BSD" 155 * c-basic-offset: 4 156 * tab-width: 4 157 * indent-tabs-mode: nil 158 * End: 159 */ 160