Patchwork [net-next] ipv6: Optimize ipv6_change_dsfield().

login
register
mail settings
Submitter YOSHIFUJI Hideaki / 吉藤英明
Date Jan. 8, 2013, 4:47 p.m.
Message ID <50EC4D8C.2080408@linux-ipv6.org>
Download mbox | patch
Permalink /patch/210434/
State Accepted
Delegated to: David Miller
Headers show

Comments

YOSHIFUJI Hideaki / 吉藤英明 - Jan. 8, 2013, 4:47 p.m.
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(-)

Patch

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);
 }