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 defined(CONFIG_VGA_CONSOLE) || defined(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