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authorMatthew Wilcox <mawilcox@microsoft.com>2017-09-09 02:14:15 +0300
committerLinus Torvalds <torvalds@linux-foundation.org>2017-09-09 04:26:48 +0300
commitac036f9570a2d318b7d8dbbdbf0e269d7cc68cef (patch)
treefe4b5aa299c97e2b496d6b1a9e0fe93f1e7b3f22
parent1caffba9db4aa27c3e7ebc05668afca1f991ab8d (diff)
downloadlinux-ac036f9570a2d318b7d8dbbdbf0e269d7cc68cef.tar.xz
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>
-rw-r--r--arch/mips/include/asm/vga.h7
-rw-r--r--arch/powerpc/include/asm/vga.h8
-rw-r--r--arch/sparc/include/asm/vga.h25
-rw-r--r--include/linux/vt_buffer.h13
4 files changed, 53 insertions, 0 deletions
diff --git a/arch/mips/include/asm/vga.h b/arch/mips/include/asm/vga.h
index f82c83749a08..975ff51f80c4 100644
--- a/arch/mips/include/asm/vga.h
+++ b/arch/mips/include/asm/vga.h
@@ -6,6 +6,7 @@
#ifndef _ASM_VGA_H
#define _ASM_VGA_H
+#include <linux/string.h>
#include <asm/addrspace.h>
#include <asm/byteorder.h>
@@ -40,9 +41,15 @@ static inline u16 scr_readw(volatile const u16 *addr)
return le16_to_cpu(*addr);
}
+static inline void scr_memsetw(u16 *s, u16 v, unsigned int count)
+{
+ memset16(s, cpu_to_le16(v), count / 2);
+}
+
#define scr_memcpyw(d, s, c) memcpy(d, s, c)
#define scr_memmovew(d, s, c) memmove(d, s, c)
#define VT_BUF_HAVE_MEMCPYW
#define VT_BUF_HAVE_MEMMOVEW
+#define VT_BUF_HAVE_MEMSETW
#endif /* _ASM_VGA_H */
diff --git a/arch/powerpc/include/asm/vga.h b/arch/powerpc/include/asm/vga.h
index ab3acd2f2786..7a7b541b7493 100644
--- a/arch/powerpc/include/asm/vga.h
+++ b/arch/powerpc/include/asm/vga.h
@@ -33,8 +33,16 @@ static inline u16 scr_readw(volatile const u16 *addr)
return le16_to_cpu(*addr);
}
+#define VT_BUF_HAVE_MEMSETW
+static inline void scr_memsetw(u16 *s, u16 v, unsigned int n)
+{
+ memset16(s, cpu_to_le16(v), n / 2);
+}
+
#define VT_BUF_HAVE_MEMCPYW
+#define VT_BUF_HAVE_MEMMOVEW
#define scr_memcpyw memcpy
+#define scr_memmovew memmove
#endif /* !CONFIG_VGA_CONSOLE && !CONFIG_MDA_CONSOLE */
diff --git a/arch/sparc/include/asm/vga.h b/arch/sparc/include/asm/vga.h
index ec0e9967d93d..f54e8b6fb197 100644
--- a/arch/sparc/include/asm/vga.h
+++ b/arch/sparc/include/asm/vga.h
@@ -8,9 +8,13 @@
#define _LINUX_ASM_VGA_H_
#include <linux/bug.h>
+#include <linux/string.h>
#include <asm/types.h>
#define VT_BUF_HAVE_RW
+#define VT_BUF_HAVE_MEMSETW
+#define VT_BUF_HAVE_MEMCPYW
+#define VT_BUF_HAVE_MEMMOVEW
#undef scr_writew
#undef scr_readw
@@ -29,6 +33,27 @@ static inline u16 scr_readw(const u16 *addr)
return *addr;
}
+static inline void scr_memsetw(u16 *p, u16 v, unsigned int n)
+{
+ BUG_ON((long) p >= 0);
+
+ memset16(p, cpu_to_le16(v), n / 2);
+}
+
+static inline void scr_memcpyw(u16 *d, u16 *s, unsigned int n)
+{
+ BUG_ON((long) d >= 0);
+
+ memcpy(d, s, n);
+}
+
+static inline void scr_memmovew(u16 *d, u16 *s, unsigned int n)
+{
+ BUG_ON((long) d >= 0);
+
+ memmove(d, s, n);
+}
+
#define VGA_MAP_MEM(x,s) (x)
#endif
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