On Tue, Feb 12, 2013 at 04:47:41PM +0200, Shlomo Pongratz wrote: > On 2/11/2013 9:46 PM, Hefty, Sean wrote: > >>>+++ b/drivers/infiniband/ulp/ipoib/ipoib_main.c > >>>@@ -844,10 +844,10 @@ static u32 ipoib_addr_hash(struct ipoib_neigh_hash > >>>*htbl, > >>>u8 *daddr) > >>> * different subnets. > >>> */ > >>> /* qpn octets[1:4) & port GUID octets[12:20) */ > >>>- u32 *daddr_32 = (u32 *) daddr; > >>>+ u32 *d32 = (u32 *)daddr; > >>> u32 hv; > >>> > >>>- hv = jhash_3words(daddr_32[3], daddr_32[4], 0xFFFFFF & daddr_32[0], 0); > >>>+ hv = jhash_3words(d32[3], d32[4], cpu_to_be32(0xFFFFFF) & d32[0], 0); > >Should d32 be declared as __be32 *? > Hi Sean, > > The IPoIB destination address is indeed in big endian format and > normally the pointer to it should be of type __be32. > However in this case I just want to feed it into the hash function > without the flags part. > defining d32 as __be32* will make the code a bit ugly as I'll need > to cast 3 of "jhash_3words" functions arguments. > That is, > > __be32 *d32; > .... > > hv = jhash_3words((__force u32) d32[3], (__force u32) d32[4], > (__force u32)(cpu_to_be32(0xFFFFFF) & d32[0]), 0);
Not sure what your hv is used for, but be aware that it is going to have a different value on big and little endian systems.. This is why the (__force u32) is somewhat desirable, because you are explicitly, and deliberately ignoring the effect of endianness at that point in the code. Jason -- To unsubscribe from this list: send the line "unsubscribe linux-rdma" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
