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
scr_memsetw(u16 * s,u16 c,unsigned int count)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
scr_memcpyw(u16 * d,const u16 * s,unsigned int count)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
scr_memmovew(u16 * d,const u16 * s,unsigned int count)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
65