xref: /linux-6.15/include/linux/vt_buffer.h (revision 9d64fc08)
1 /*
2  *	include/linux/vt_buffer.h -- Access to VT screen buffer
3  *
4  *	(c) 1998 Martin Mares <[email protected]>
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/string.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 #endif
26 
27 #ifndef VT_BUF_HAVE_MEMSETW
28 static inline void scr_memsetw(u16 *s, u16 c, unsigned int count)
29 {
30 #ifdef VT_BUF_HAVE_RW
31 	count /= 2;
32 	while (count--)
33 		scr_writew(c, s++);
34 #else
35 	memset16(s, c, count / 2);
36 #endif
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 #ifdef VT_BUF_HAVE_RW
44 	count /= 2;
45 	while (count--)
46 		scr_writew(scr_readw(s++), d++);
47 #else
48 	memcpy(d, s, count);
49 #endif
50 }
51 #endif
52 
53 #ifndef VT_BUF_HAVE_MEMMOVEW
54 static inline void scr_memmovew(u16 *d, const u16 *s, unsigned int count)
55 {
56 #ifdef VT_BUF_HAVE_RW
57 	if (d < s)
58 		scr_memcpyw(d, s, count);
59 	else {
60 		count /= 2;
61 		d += count;
62 		s += count;
63 		while (count--)
64 			scr_writew(scr_readw(--s), --d);
65 	}
66 #else
67 	memmove(d, s, count);
68 #endif
69 }
70 #endif
71 
72 #endif
73