1b2441318SGreg Kroah-Hartman /* SPDX-License-Identifier: GPL-2.0 */
21da177e4SLinus Torvalds /*
31da177e4SLinus Torvalds * include/linux/vt_buffer.h -- Access to VT screen buffer
41da177e4SLinus Torvalds *
51da177e4SLinus Torvalds * (c) 1998 Martin Mares <mj@ucw.cz>
61da177e4SLinus Torvalds *
71da177e4SLinus Torvalds * This is a set of macros and functions which are used in the
81da177e4SLinus Torvalds * console driver and related code to access the screen buffer.
91da177e4SLinus Torvalds * In most cases the console works with simple in-memory buffer,
101da177e4SLinus Torvalds * but when handling hardware text mode consoles, we store
111da177e4SLinus Torvalds * the foreground console directly in video memory.
121da177e4SLinus Torvalds */
131da177e4SLinus Torvalds
141da177e4SLinus Torvalds #ifndef _LINUX_VT_BUFFER_H_
151da177e4SLinus Torvalds #define _LINUX_VT_BUFFER_H_
161da177e4SLinus Torvalds
17ac036f95SMatthew Wilcox #include <linux/string.h>
181da177e4SLinus Torvalds
19*bfff83c4SRandy Dunlap #if IS_ENABLED(CONFIG_VGA_CONSOLE) || IS_ENABLED(CONFIG_MDA_CONSOLE)
201da177e4SLinus Torvalds #include <asm/vga.h>
211da177e4SLinus Torvalds #endif
221da177e4SLinus Torvalds
231da177e4SLinus Torvalds #ifndef VT_BUF_HAVE_RW
241da177e4SLinus Torvalds #define scr_writew(val, addr) (*(addr) = (val))
251da177e4SLinus Torvalds #define scr_readw(addr) (*(addr))
261da177e4SLinus Torvalds #endif
271da177e4SLinus Torvalds
281da177e4SLinus Torvalds #ifndef VT_BUF_HAVE_MEMSETW
scr_memsetw(u16 * s,u16 c,unsigned int count)291da177e4SLinus Torvalds static inline void scr_memsetw(u16 *s, u16 c, unsigned int count)
301da177e4SLinus Torvalds {
31ac036f95SMatthew Wilcox #ifdef VT_BUF_HAVE_RW
321da177e4SLinus Torvalds count /= 2;
331da177e4SLinus Torvalds while (count--)
341da177e4SLinus Torvalds scr_writew(c, s++);
35ac036f95SMatthew Wilcox #else
36ac036f95SMatthew Wilcox memset16(s, c, count / 2);
37ac036f95SMatthew Wilcox #endif
381da177e4SLinus Torvalds }
391da177e4SLinus Torvalds #endif
401da177e4SLinus Torvalds
411da177e4SLinus Torvalds #ifndef VT_BUF_HAVE_MEMCPYW
scr_memcpyw(u16 * d,const u16 * s,unsigned int count)421da177e4SLinus Torvalds static inline void scr_memcpyw(u16 *d, const u16 *s, unsigned int count)
431da177e4SLinus Torvalds {
44ac036f95SMatthew Wilcox #ifdef VT_BUF_HAVE_RW
451da177e4SLinus Torvalds count /= 2;
461da177e4SLinus Torvalds while (count--)
471da177e4SLinus Torvalds scr_writew(scr_readw(s++), d++);
48ac036f95SMatthew Wilcox #else
49ac036f95SMatthew Wilcox memcpy(d, s, count);
50ac036f95SMatthew Wilcox #endif
511da177e4SLinus Torvalds }
521da177e4SLinus Torvalds #endif
531da177e4SLinus Torvalds
541da177e4SLinus Torvalds #ifndef VT_BUF_HAVE_MEMMOVEW
scr_memmovew(u16 * d,const u16 * s,unsigned int count)551da177e4SLinus Torvalds static inline void scr_memmovew(u16 *d, const u16 *s, unsigned int count)
561da177e4SLinus Torvalds {
57ac036f95SMatthew Wilcox #ifdef VT_BUF_HAVE_RW
581da177e4SLinus Torvalds if (d < s)
591da177e4SLinus Torvalds scr_memcpyw(d, s, count);
601da177e4SLinus Torvalds else {
611da177e4SLinus Torvalds count /= 2;
621da177e4SLinus Torvalds d += count;
631da177e4SLinus Torvalds s += count;
641da177e4SLinus Torvalds while (count--)
651da177e4SLinus Torvalds scr_writew(scr_readw(--s), --d);
661da177e4SLinus Torvalds }
67ac036f95SMatthew Wilcox #else
68ac036f95SMatthew Wilcox memmove(d, s, count);
69ac036f95SMatthew Wilcox #endif
701da177e4SLinus Torvalds }
711da177e4SLinus Torvalds #endif
721da177e4SLinus Torvalds
731da177e4SLinus Torvalds #endif
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