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 #endif
  25
  26 #ifndef VT_BUF_HAVE_MEMSETW
  27 static inline void scr_memsetw(u16 *s, u16 c, unsigned int count)
  28 {
  29         count /= 2;
  30         while (count--)
  31                 scr_writew(c, s++);
  32 }
  33 #endif
  34
  35 #ifndef VT_BUF_HAVE_MEMCPYW
  36 static inline void scr_memcpyw(u16 *d, const u16 *s, unsigned int count)
  37 {
  38         count /= 2;
  39         while (count--)
  40                 scr_writew(scr_readw(s++), d++);
  41 }
  42 #endif
  43
  44 #ifndef VT_BUF_HAVE_MEMMOVEW
  45 static inline void scr_memmovew(u16 *d, const u16 *s, unsigned int count)
  46 {
  47         if (d < s)
  48                 scr_memcpyw(d, s, count);
  49         else {
  50                 count /= 2;
  51                 d += count;
  52                 s += count;
  53                 while (count--)
  54                         scr_writew(scr_readw(--s), --d);
  55         }
  56 }
  57 #endif
  58
  59 #endif