1 /* SPDX-License-Identifier: GPL-2.0 */
2 /*
3 * include/linux/vt_buffer.h -- Access to VT screen buffer
4 *
5 * (c) 1998 Martin Mares <mj@ucw.cz>
6 *
7 * This is a set of macros and functions which are used in the
8 * console driver and related code to access the screen buffer.
9 * In most cases the console works with simple in-memory buffer,
10 * but when handling hardware text mode consoles, we store
11 * the foreground console directly in video memory.
12 */
13
14 #ifndef _LINUX_VT_BUFFER_H_
15 #define _LINUX_VT_BUFFER_H_
16
17 #include <linux/string.h>
18
19 #if IS_ENABLED(CONFIG_VGA_CONSOLE) || IS_ENABLED(CONFIG_MDA_CONSOLE)
20 #include <asm/vga.h>
21 #endif
22
23 #ifndef VT_BUF_HAVE_RW
24 #define scr_writew(val, addr) (*(addr) = (val))
25 #define scr_readw(addr) (*(addr))
26 #endif
27
28 #ifndef VT_BUF_HAVE_MEMSETW
29 static inline void scr_memsetw(u16 *s, u16 c, unsigned int count)
30 {
31 #ifdef VT_BUF_HAVE_RW
32 count /= 2;
33 while (count--)
34 scr_writew(c, s++);
35 #else
36 memset16(s, c, count / 2);
37 #endif
38 }
39 #endif
40
41 #ifndef VT_BUF_HAVE_MEMCPYW
42 static inline void scr_memcpyw(u16 *d, const u16 *s, unsigned int count)
43 {
44 #ifdef VT_BUF_HAVE_RW
45 count /= 2;
46 while (count--)
47 scr_writew(scr_readw(s++), d++);
48 #else
49 memcpy(d, s, count);
50 #endif
51 }
52 #endif
53
54 #ifndef VT_BUF_HAVE_MEMMOVEW
55 static inline void scr_memmovew(u16 *d, const u16 *s, unsigned int count)
56 {
57 #ifdef VT_BUF_HAVE_RW
58 if (d < s)
59 scr_memcpyw(d, s, count);
60 else {
61 count /= 2;
62 d += count;
63 s += count;
64 while (count--)
65 scr_writew(scr_readw(--s), --d);
66 }
67 #else
68 memmove(d, s, count);
69 #endif
70 }
71 #endif
72
73 #endif
74
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