From: Matthew Wilcox <willy@infradead.org>
To: linux-kernel@vger.kernel.org
Cc: minchan@kernel.org, Matthew Wilcox <mawilcox@microsoft.com>,
akpm@linuxfoundation.org, mpe@ellerman.id.au
Subject: [PATCH v4 8/8] vga: Optimise console scrolling
Date: Thu, 20 Jul 2017 11:45:39 -0700 [thread overview]
Message-ID: <20170720184539.31609-9-willy@infradead.org> (raw)
In-Reply-To: <20170720184539.31609-1-willy@infradead.org>
From: Matthew Wilcox <mawilcox@microsoft.com>
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.
Signed-off-by: Matthew Wilcox <mawilcox@microsoft.com>
---
arch/mips/include/asm/vga.h | 7 +++++++
arch/powerpc/include/asm/vga.h | 8 ++++++++
arch/sparc/include/asm/vga.h | 25 +++++++++++++++++++++++++
include/linux/vt_buffer.h | 12 ++++++++++++
4 files changed, 52 insertions(+)
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..31b92fcd8f03 100644
--- a/include/linux/vt_buffer.h
+++ b/include/linux/vt_buffer.h
@@ -26,24 +26,33 @@
#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 +62,9 @@ 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
--
2.13.2
next prev parent reply other threads:[~2017-07-20 18:45 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-07-20 18:45 [PATCH v4 0/8] Multibyte memset variations Matthew Wilcox
2017-07-20 18:45 ` [PATCH v4 1/8] Add multibyte memset functions Matthew Wilcox
2017-07-20 18:45 ` [PATCH v4 2/8] Add testcases for memset16/32/64 Matthew Wilcox
2017-07-20 18:45 ` [PATCH v4 3/8] x86: Implement memset16, memset32 & memset64 Matthew Wilcox
2017-07-20 18:45 ` [PATCH v4 4/8] ARM: Implement " Matthew Wilcox
2017-07-20 18:45 ` [PATCH v4 5/8] alpha: Add support for memset16 Matthew Wilcox
2017-07-20 18:45 ` [PATCH v4 6/8] zram: Convert to using memset_l Matthew Wilcox
2017-07-20 18:45 ` [PATCH v4 7/8] sym53c8xx_2: Convert to use memset32 Matthew Wilcox
2017-07-20 18:45 ` Matthew Wilcox [this message]
2017-07-25 5:27 ` [PATCH v4 0/8] Multibyte memset variations Michael Ellerman
2017-07-25 13:08 ` Matthew Wilcox
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