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| author | Matthew Wilcox <mawilcox@microsoft.com> | 2017-09-08 16:14:15 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2017-09-08 18:26:48 -0700 |
| commit | ac036f9570a2d318b7d8dbbdbf0e269d7cc68cef (patch) | |
| tree | fe4b5aa299c97e2b496d6b1a9e0fe93f1e7b3f22 /include/linux | |
| parent | 1caffba9db4aa27c3e7ebc05668afca1f991ab8d (diff) | |
| download | linux-ac036f9570a2d318b7d8dbbdbf0e269d7cc68cef.tar.gz linux-ac036f9570a2d318b7d8dbbdbf0e269d7cc68cef.tar.bz2 linux-ac036f9570a2d318b7d8dbbdbf0e269d7cc68cef.zip | |
vga: optimise console scrolling
Where possible, call memset16(), memmove() or memcpy() instead of using
open-coded loops. I don't like the calling convention that uses a byte
count instead of a count of u16s, but it's a little late to change that.
Reduces code size of fbcon.o by almost 400 bytes on my laptop build.
[akpm@linux-foundation.org: fix build]
Link: http://lkml.kernel.org/r/20170720184539.31609-9-willy@infradead.org
Signed-off-by: Matthew Wilcox <mawilcox@microsoft.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: David Miller <davem@davemloft.net>
Cc: Sam Ravnborg <sam@ravnborg.org>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: "James E.J. Bottomley" <jejb@linux.vnet.ibm.com>
Cc: "Martin K. Petersen" <martin.petersen@oracle.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: Matt Turner <mattst88@gmail.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Russell King <rmk+kernel@armlinux.org.uk>
Cc: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'include/linux')
| -rw-r--r-- | include/linux/vt_buffer.h | 13 |
1 files changed, 13 insertions, 0 deletions
diff --git a/include/linux/vt_buffer.h b/include/linux/vt_buffer.h index f38c10ba3ff5..30b6e0d2a942 100644 --- a/include/linux/vt_buffer.h +++ b/include/linux/vt_buffer.h @@ -13,6 +13,7 @@ #ifndef _LINUX_VT_BUFFER_H_ #define _LINUX_VT_BUFFER_H_ +#include <linux/string.h> #if defined(CONFIG_VGA_CONSOLE) || defined(CONFIG_MDA_CONSOLE) #include <asm/vga.h> @@ -26,24 +27,33 @@ #ifndef VT_BUF_HAVE_MEMSETW static inline void scr_memsetw(u16 *s, u16 c, unsigned int count) { +#ifdef VT_BUF_HAVE_RW count /= 2; while (count--) scr_writew(c, s++); +#else + memset16(s, c, count / 2); +#endif } #endif #ifndef VT_BUF_HAVE_MEMCPYW static inline void scr_memcpyw(u16 *d, const u16 *s, unsigned int count) { +#ifdef VT_BUF_HAVE_RW count /= 2; while (count--) scr_writew(scr_readw(s++), d++); +#else + memcpy(d, s, count); +#endif } #endif #ifndef VT_BUF_HAVE_MEMMOVEW static inline void scr_memmovew(u16 *d, const u16 *s, unsigned int count) { +#ifdef VT_BUF_HAVE_RW if (d < s) scr_memcpyw(d, s, count); else { @@ -53,6 +63,9 @@ static inline void scr_memmovew(u16 *d, const u16 *s, unsigned int count) while (count--) scr_writew(scr_readw(--s), --d); } +#else + memmove(d, s, count); +#endif } #endif |