aboutsummaryrefslogtreecommitdiffstats
path: root/include/linux/vt_buffer.h
diff options
context:
space:
mode:
authorMatthew Wilcox <mawilcox@microsoft.com>2017-09-08 16:14:15 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2017-09-08 18:26:48 -0700
commitac036f9570a2d318b7d8dbbdbf0e269d7cc68cef (patch)
treefe4b5aa299c97e2b496d6b1a9e0fe93f1e7b3f22 /include/linux/vt_buffer.h
parentdrivers/scsi/sym53c8xx_2/sym_hipd.c: convert to use memset32 (diff)
downloadlinux-dev-ac036f9570a2d318b7d8dbbdbf0e269d7cc68cef.tar.xz
linux-dev-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 '')
-rw-r--r--include/linux/vt_buffer.h13
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