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
scr_memsetw(u16 * s,u16 c,unsigned int count)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
scr_memcpyw(u16 * d,const u16 * s,unsigned int count)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
scr_memmovew(u16 * d,const u16 * s,unsigned int count)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
64