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authorDmitry Torokhov <dmitry.torokhov@gmail.com>2015-02-20 11:54:53 -0800
committerDmitry Torokhov <dmitry.torokhov@gmail.com>2015-02-20 11:54:53 -0800
commit4c971aa78314253cce914ed29e3d90df3326d646 (patch)
treea9dcf0b1fdc9e1aacff90afb5b3ab79983115dcc /lib
parentMerge branch 'next' into for-linus (diff)
parentInput: psmouse - use IS_ENABLED instead of homegrown code (diff)
downloadlinux-dev-4c971aa78314253cce914ed29e3d90df3326d646.tar.xz
linux-dev-4c971aa78314253cce914ed29e3d90df3326d646.zip
Merge branch 'next' into for-linus
Second round of updates for 3.20.
Diffstat (limited to 'lib')
-rw-r--r--lib/checksum.c12
1 files changed, 10 insertions, 2 deletions
diff --git a/lib/checksum.c b/lib/checksum.c
index 129775eb6de6..8b39e86dbab5 100644
--- a/lib/checksum.c
+++ b/lib/checksum.c
@@ -181,6 +181,15 @@ csum_partial_copy(const void *src, void *dst, int len, __wsum sum)
EXPORT_SYMBOL(csum_partial_copy);
#ifndef csum_tcpudp_nofold
+static inline u32 from64to32(u64 x)
+{
+ /* add up 32-bit and 32-bit for 32+c bit */
+ x = (x & 0xffffffff) + (x >> 32);
+ /* add up carry.. */
+ x = (x & 0xffffffff) + (x >> 32);
+ return (u32)x;
+}
+
__wsum csum_tcpudp_nofold(__be32 saddr, __be32 daddr,
unsigned short len,
unsigned short proto,
@@ -195,8 +204,7 @@ __wsum csum_tcpudp_nofold(__be32 saddr, __be32 daddr,
#else
s += (proto + len) << 8;
#endif
- s += (s >> 32);
- return (__force __wsum)s;
+ return (__force __wsum)from64to32(s);
}
EXPORT_SYMBOL(csum_tcpudp_nofold);
#endif