The commit 8e3d8433d8c22ca6c42cba4a67d300c39aae7822 ([NET]: MIPS checksum annotations and cleanups) broke 64-bit MIPS. The problem is the commit replaces some unsigned long with __be32. On 64bit MIPS, a __be32 (i.e. unsigned int) value is represented as a sign-extented 32-bit value in a 64-bit argument register. So the address 192.168.0.1 (0xc0a80001) is passed as 0xffffffffc0a80001 to csum_tcpudp_nofold() but the asm code in the function expects 0x00000000c0a80001, therefore it returns a wrong checksum. Explicit cast to unsigned long is needed to drop high 32bit. Signed-off-by: Atsushi Nemoto <anemo@xxxxxxxxxxxxx> --- diff --git a/include/asm-mips/checksum.h b/include/asm-mips/checksum.h index 24cdcc6..20a81e1 100644 --- a/include/asm-mips/checksum.h +++ b/include/asm-mips/checksum.h @@ -159,7 +159,8 @@ static inline __wsum csum_tcpudp_nofold(__be32 saddr, #endif " .set pop" : "=r" (sum) - : "0" (daddr), "r"(saddr), + : "0" ((__force unsigned long)daddr), + "r" ((__force unsigned long)saddr), #ifdef __MIPSEL__ "r" ((proto + len) << 8), #else
