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
32static 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
41static 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
50static 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
65