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 #include <linux/config.h>
  17
  18 #if defined(CONFIG_VGA_CONSOLE) || defined(CONFIG_MDA_CONSOLE)
  19 #include <asm/vga.h>
  20 #endif
  21
  22 #ifndef VT_BUF_HAVE_RW
  23 #define scr_writew(val, addr) (*(addr) = (val))
  24 #define scr_readw(addr) (*(addr))
  25 #define scr_memcpyw(d, s, c) memcpy(d, s, c)
  26 #define scr_memmovew(d, s, c) memmove(d, s, c)
  27 #define VT_BUF_HAVE_MEMCPYW
  28 #define VT_BUF_HAVE_MEMMOVEW
  29 #endif
  30
  31 #ifndef VT_BUF_HAVE_MEMSETW
  32 static inline void scr_memsetw(u16 *s, u16 c, unsigned int count)
  33 {
  34         count /= 2;
  35         while (count--)
  36                 scr_writew(c, s++);
  37 }
  38 #endif
  39
  40 #ifndef VT_BUF_HAVE_MEMCPYW
  41 static inline void scr_memcpyw(u16 *d, const u16 *s, unsigned int count)
  42 {
  43         count /= 2;
  44         while (count--)
  45                 scr_writew(scr_readw(s++), d++);
  46 }
  47 #endif
  48
  49 #ifndef VT_BUF_HAVE_MEMMOVEW
  50 static inline void scr_memmovew(u16 *d, const u16 *s, unsigned int count)
  51 {
  52         if (d < s)
  53                 scr_memcpyw(d, s, count);
  54         else {
  55                 count /= 2;
  56                 d += count;
  57                 s += count;
  58                 while (count--)
  59                         scr_writew(scr_readw(--s), --d);
  60         }
  61 }
  62 #endif
  63
  64 #endif