include/linux/vt_buffer.h

   1 /*
   2  *      include/linux/vt_buffer.h -- Access to VT screen buffer
   3  *
   4  *      (c) 1998 Martin Mares <mj@ucw.cz>
   5  *
   6  *      This is a set of macros and functions which are used in the
   7  *      console driver and related code to access the screen buffer.
   8  *      In most cases the console works with simple in-memory buffer,
   9  *      but when handling hardware text mode consoles, we store
  10  *      the foreground console directly in video memory.
  11  */
  12
  13 #ifndef _LINUX_VT_BUFFER_H_
  14 #define _LINUX_VT_BUFFER_H_
  15
  16
  17 #if defined(CONFIG_VGA_CONSOLE) || defined(CONFIG_MDA_CONSOLE)
  18 #include <asm/vga.h>
  19 #endif
  20
  21 #ifndef VT_BUF_HAVE_RW
  22 #define scr_writew(val, addr) (*(addr) = (val))
  23 #define scr_readw(addr) (*(addr))
  24 #define scr_memcpyw(d, s, c) memcpy(d, s, c)
  25 #define scr_memmovew(d, s, c) memmove(d, s, c)
  26 #define VT_BUF_HAVE_MEMCPYW
  27 #define VT_BUF_HAVE_MEMMOVEW
  28 #endif
  29
  30 #ifndef VT_BUF_HAVE_MEMSETW
  31 static inline void scr_memsetw(u16 *s, u16 c, unsigned int count)
  32 {
  33         count /= 2;
  34         while (count--)
  35                 scr_writew(c, s++);
  36 }
  37 #endif
  38
  39 #ifndef VT_BUF_HAVE_MEMCPYW
  40 static inline void scr_memcpyw(u16 *d, const u16 *s, unsigned int count)
  41 {
  42         count /= 2;
  43         while (count--)
  44                 scr_writew(scr_readw(s++), d++);
  45 }
  46 #endif
  47
  48 #ifndef VT_BUF_HAVE_MEMMOVEW
  49 static inline void scr_memmovew(u16 *d, const u16 *s, unsigned int count)
  50 {
  51         if (d < s)
  52                 scr_memcpyw(d, s, count);
  53         else {
  54                 count /= 2;
  55                 d += count;
  56                 s += count;
  57                 while (count--)
  58                         scr_writew(scr_readw(--s), --d);
  59         }
  60 }
  61 #endif
  62
  63 #endif