From a0376db0f234a8053100bddf26c073be79546b2b Mon Sep 17 00:00:00 2001
From: =?utf8?q?YOSHIFUJI=20Hideaki=20/=20=E5=90=89=E8=97=A4=E8=8B=B1?=
=?utf8?q?=E6=98=8E?= <yoshfuji@linux-ipv6.org>
Date: Tue, 8 Jan 2013 06:47:08 +0000
Subject: [PATCH] ipv6: Optimize ipv6_change_dsfield().
Do not convert endian back and forth.
If the caller uses contant "mask" argument (and most callers do),
we can omit runtime endian conversion here.
Signed-off-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
---
include/net/dsfield.h | 6 ++----
1 file changed, 2 insertions(+), 4 deletions(-)
diff --git a/include/net/dsfield.h b/include/net/dsfield.h
index 8a8d4e06900d..e1ad903a8d6a 100644
--- a/include/net/dsfield.h
+++ b/include/net/dsfield.h
@@ -43,11 +43,9 @@ static inline void ipv4_change_dsfield(struct iphdr *iph,__u8 mask,
static inline void ipv6_change_dsfield(struct ipv6hdr *ipv6h,__u8 mask,
__u8 value)
{
- __u16 tmp;
+ __be16 *p = (__force __be16 *)ipv6h;
- tmp = ntohs(*(__be16 *) ipv6h);
- tmp = (tmp & ((mask << 4) | 0xf00f)) | (value << 4);
- *(__be16 *) ipv6h = htons(tmp);
+ *p = (*p & htons((((u16)mask << 4) | 0xf00f))) | htons((u16)value << 4);
}
--
2.34.1