Commit c5cdfdf9 authored Feb 27, 2014 by Jan Beulich Committed by H. Peter Anvin Mar 19, 2014

x86, hash: Swap arguments passed to crc32_u32()



... to match the function's parameters. While reportedly commutative,
using the proper order allows for leveraging the instruction permitting
the source operand to be in memory.

[ hpa: This code originated in the dpdk toolkit.  This was a bug in dpdk
  which has recently been fixed in part due to an earlier version of
  this patch. ]

Signed-off-by: Jan Beulich <jbeulich@suse.com>
Link: http://lkml.kernel.org/r/530F09B6020000780011FBEB@nat28.tlf.novell.com


Acked-by: Daniel Borkmann <dborkman@redhat.com>
Cc: Francesco Fusco <ffusco@redhat.com>
Cc: Thomas Graf <tgraf@redhat.com>
Cc: David S. Miller <davem@davemloft.net>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>

parent 06325190

arch/x86/lib/hash.c

+3 −3

Original line number	Diff line number	Diff line
		@@ -53,7 +53,7 @@ static u32 intel_crc4_2_hash(const void *data, u32 len, u32 seed)
		u32 i, tmp = 0;

		for (i = 0; i < len / 4; i++)
		seed = crc32_u32(*p32++, seed);
		seed = crc32_u32(seed, *p32++);

		switch (3 - (len & 0x03)) {
		case 0:
		@@ -64,7 +64,7 @@ static u32 intel_crc4_2_hash(const void *data, u32 len, u32 seed)
		/* fallthrough */
		case 2:
		tmp \|= ((const u8 ) p32);
		seed = crc32_u32(tmp, seed);
		seed = crc32_u32(seed, tmp);
		default:
		break;
		}
		@@ -78,7 +78,7 @@ static u32 intel_crc4_2_hash2(const u32 *data, u32 len, u32 seed)
		u32 i;

		for (i = 0; i < len; i++)
		seed = crc32_u32(*p32++, seed);
		seed = crc32_u32(seed, *p32++);

		return seed;
		}

Admin message