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authorFinn Thain <fthain@telegraphics.com.au>2018-10-13 11:47:55 +1100
committerGeert Uytterhoeven <geert@linux-m68k.org>2018-12-03 13:05:42 +0100
commitb6cf523c16e148e1ece5fc4ff4657d79323a4635 (patch)
treea0268d6a6f4dd3651ef3f505d0acf22b5c1fe8b6 /arch/m68k
parent651022382c7f8da46cb4872a545ee1da6d097d2a (diff)
m68k: Unroll raw_outsb() loop
Unroll the raw_outsb() loop using the optimized assembler code from raw_outsw(). That code is copied and pasted, with movew changed to moveb. This improves the performance of sequential write transfers using mac_esp in PIO mode by 5% or 10%. (The DMA controller on the 840av/660av models is still unsupported so PIO transfers are used.) Tested-by: Stan Johnson <userm57@yahoo.com> Signed-off-by: Finn Thain <fthain@telegraphics.com.au> Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Diffstat (limited to 'arch/m68k')
-rw-r--r--arch/m68k/include/asm/raw_io.h39
1 files changed, 35 insertions, 4 deletions
diff --git a/arch/m68k/include/asm/raw_io.h b/arch/m68k/include/asm/raw_io.h
index 85761255dde5..8a6dc6e5a279 100644
--- a/arch/m68k/include/asm/raw_io.h
+++ b/arch/m68k/include/asm/raw_io.h
@@ -107,12 +107,43 @@ static inline void raw_insb(volatile u8 __iomem *port, u8 *buf, unsigned int len
}
static inline void raw_outsb(volatile u8 __iomem *port, const u8 *buf,
- unsigned int len)
+ unsigned int nr)
{
- unsigned int i;
+ unsigned int tmp;
- for (i = 0; i < len; i++)
- out_8(port, *buf++);
+ if (nr & 15) {
+ tmp = (nr & 15) - 1;
+ asm volatile (
+ "1: moveb %0@+,%2@; dbra %1,1b"
+ : "=a" (buf), "=d" (tmp)
+ : "a" (port), "0" (buf),
+ "1" (tmp));
+ }
+ if (nr >> 4) {
+ tmp = (nr >> 4) - 1;
+ asm volatile (
+ "1: "
+ "moveb %0@+,%2@; "
+ "moveb %0@+,%2@; "
+ "moveb %0@+,%2@; "
+ "moveb %0@+,%2@; "
+ "moveb %0@+,%2@; "
+ "moveb %0@+,%2@; "
+ "moveb %0@+,%2@; "
+ "moveb %0@+,%2@; "
+ "moveb %0@+,%2@; "
+ "moveb %0@+,%2@; "
+ "moveb %0@+,%2@; "
+ "moveb %0@+,%2@; "
+ "moveb %0@+,%2@; "
+ "moveb %0@+,%2@; "
+ "moveb %0@+,%2@; "
+ "moveb %0@+,%2@; "
+ "dbra %1,1b"
+ : "=a" (buf), "=d" (tmp)
+ : "a" (port), "0" (buf),
+ "1" (tmp));
+ }
}
static inline void raw_insw(volatile u16 __iomem *port, u16 *buf, unsigned int nr)