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, v: c, n: 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 | |