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      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 (at) us.ibm.com>
     23  * Copyright (C) 2006 Red Hat, Inc., Markus Armbruster <armbru (at) 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 {
     46     uint8_t type;    /* XENFB_TYPE_UPDATE */
     47     int32_t x;      /* source x */
     48     int32_t y;      /* source y */
     49     int32_t width;  /* rect width */
     50     int32_t height; /* rect height */
     51 };
     52 
     53 /*
     54  * Framebuffer resize notification event
     55  * Capable backend sets feature-resize in xenstore.
     56  */
     57 #define XENFB_TYPE_RESIZE 3
     58 
     59 struct xenfb_resize
     60 {
     61     uint8_t type;    /* XENFB_TYPE_RESIZE */
     62     int32_t width;   /* width in pixels */
     63     int32_t height;  /* height in pixels */
     64     int32_t stride;  /* stride in bytes */
     65     int32_t depth;   /* depth in bits */
     66     int32_t offset;  /* offset of the framebuffer in bytes */
     67 };
     68 
     69 #define XENFB_OUT_EVENT_SIZE 40
     70 
     71 union xenfb_out_event
     72 {
     73     uint8_t type;
     74     struct xenfb_update update;
     75     struct xenfb_resize resize;
     76     char pad[XENFB_OUT_EVENT_SIZE];
     77 };
     78 
     79 /* In events (backend -> frontend) */
     80 
     81 /*
     82  * Frontends should ignore unknown in events.
     83  */
     84 
     85 /*
     86  * Framebuffer refresh period advice
     87  * Backend sends it to advise the frontend their preferred period of
     88  * refresh.  Frontends that keep the framebuffer constantly up-to-date
     89  * just ignore it.  Frontends that use the advice should immediately
     90  * refresh the framebuffer (and send an update notification event if
     91  * those have been requested), then use the update frequency to guide
     92  * their periodical refreshs.
     93  */
     94 #define XENFB_TYPE_REFRESH_PERIOD 1
     95 #define XENFB_NO_REFRESH 0
     96 
     97 struct xenfb_refresh_period
     98 {
     99     uint8_t type;    /* XENFB_TYPE_UPDATE_PERIOD */
    100     uint32_t period; /* period of refresh, in ms,
    101                       * XENFB_NO_REFRESH if no refresh is needed */
    102 };
    103 
    104 #define XENFB_IN_EVENT_SIZE 40
    105 
    106 union xenfb_in_event
    107 {
    108     uint8_t type;
    109     struct xenfb_refresh_period refresh_period;
    110     char pad[XENFB_IN_EVENT_SIZE];
    111 };
    112 
    113 /* shared page */
    114 
    115 #define XENFB_IN_RING_SIZE 1024
    116 #define XENFB_IN_RING_LEN (XENFB_IN_RING_SIZE / XENFB_IN_EVENT_SIZE)
    117 #define XENFB_IN_RING_OFFS 1024
    118 #define XENFB_IN_RING(page) \
    119     ((union xenfb_in_event *)((char *)(page) + XENFB_IN_RING_OFFS))
    120 #define XENFB_IN_RING_REF(page, idx) \
    121     (XENFB_IN_RING((page))[(idx) % XENFB_IN_RING_LEN])
    122 
    123 #define XENFB_OUT_RING_SIZE 2048
    124 #define XENFB_OUT_RING_LEN (XENFB_OUT_RING_SIZE / XENFB_OUT_EVENT_SIZE)
    125 #define XENFB_OUT_RING_OFFS (XENFB_IN_RING_OFFS + XENFB_IN_RING_SIZE)
    126 #define XENFB_OUT_RING(page) \
    127     ((union xenfb_out_event *)((char *)(page) + XENFB_OUT_RING_OFFS))
    128 #define XENFB_OUT_RING_REF(page, idx) \
    129     (XENFB_OUT_RING((page))[(idx) % XENFB_OUT_RING_LEN])
    130 
    131 struct xenfb_page
    132 {
    133     uint32_t in_cons, in_prod;
    134     uint32_t out_cons, out_prod;
    135 
    136     int32_t width;          /* the width of the framebuffer (in pixels) */
    137     int32_t height;         /* the height of the framebuffer (in pixels) */
    138     uint32_t line_length;   /* the length of a row of pixels (in bytes) */
    139     uint32_t mem_length;    /* the length of the framebuffer (in bytes) */
    140     uint8_t depth;          /* the depth of a pixel (in bits) */
    141 
    142     /*
    143      * Framebuffer page directory
    144      *
    145      * Each directory page holds PAGE_SIZE / sizeof(*pd)
    146      * framebuffer pages, and can thus map up to PAGE_SIZE *
    147      * PAGE_SIZE / sizeof(*pd) bytes.  With PAGE_SIZE == 4096 and
    148      * sizeof(unsigned long) == 4/8, that's 4 Megs 32 bit and 2 Megs
    149      * 64 bit.  256 directories give enough room for a 512 Meg
    150      * framebuffer with a max resolution of 12,800x10,240.  Should
    151      * be enough for a while with room leftover for expansion.
    152      */
    153     unsigned long pd[256];
    154 };
    155 
    156 /*
    157  * Wart: xenkbd needs to know default resolution.  Put it here until a
    158  * better solution is found, but don't leak it to the backend.
    159  */
    160 #ifdef __KERNEL__
    161 #define XENFB_WIDTH 800
    162 #define XENFB_HEIGHT 600
    163 #define XENFB_DEPTH 32
    164 #endif
    165 
    166 #endif
    167 
    168 /*
    169  * Local variables:
    170  * mode: C
    171  * c-file-style: "BSD"
    172  * c-basic-offset: 4
    173  * tab-width: 4
    174  * indent-tabs-mode: nil
    175  * End:
    176  */
    177