From: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
To: davem@davemloft.net, netdev@vger.kernel.org
Cc: yoshfuji@linux-ipv6.org
Subject: [PATCH net-next] ipv6: Optimize ipv6_change_dsfield().
Date: Wed, 09 Jan 2013 01:47:08 +0900 [thread overview]
Message-ID: <50EC4D8C.2080408@linux-ipv6.org> (raw)
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>
---
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 8a8d4e0..e1ad903 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);
}
--
1.7.9.5
reply other threads:[~2013-01-08 16:47 UTC|newest]
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