[PATCH net-next] ipv6: Optimize ipv6_change_dsfield().
From: YOSHIFUJI Hideaki <hidden>
Date: 2013-01-08 16:47:10
Subsystem:
networking [general], the rest · Maintainers:
"David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Linus Torvalds
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 <redacted> --- 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