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
27static 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
36static 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
45static 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
60