From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752992AbaBXIDw (ORCPT ); Mon, 24 Feb 2014 03:03:52 -0500 Received: from nat28.tlf.novell.com ([130.57.49.28]:46899 "EHLO nat28.tlf.novell.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752965AbaBXIDu convert rfc822-to-8bit (ORCPT ); Mon, 24 Feb 2014 03:03:50 -0500 Message-Id: <530B0AF2020000780011E97B@nat28.tlf.novell.com> X-Mailer: Novell GroupWise Internet Agent 12.0.2 Date: Mon, 24 Feb 2014 08:03:46 +0000 From: "Jan Beulich" To: "Daniel Borkmann" Cc: , , , , , , Subject: Re: [PATCH 2/3] x86/hash: swap parameters of crc32_u32() References: <53073986020000780011E2E1@nat28.tlf.novell.com> <5308938A.8070506@redhat.com> In-Reply-To: <5308938A.8070506@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 8BIT Content-Disposition: inline Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org >>> On 22.02.14 at 13:09, Daniel Borkmann wrote: > On 02/21/2014 11:33 AM, Jan Beulich wrote: >> ... to match its two callers (i.e. the alternative would have been to >> swap the arguments at the call sites). >> >> Signed-off-by: Jan Beulich >> Cc: Francesco Fusco >> Cc: Daniel Borkmann >> Cc: Thomas Graf >> Cc: David S. Miller >> --- >> arch/x86/lib/hash.c | 2 +- >> 1 file changed, 1 insertion(+), 1 deletion(-) >> >> --- 3.14-rc3-x86-hash-crc32.orig/arch/x86/lib/hash.c >> +++ 3.14-rc3-x86-hash-crc32/arch/x86/lib/hash.c >> @@ -37,7 +37,7 @@ >> #include >> #include >> >> -static inline u32 crc32_u32(u32 crc, u32 val) >> +static inline u32 crc32_u32(u32 val, u32 crc) >> { >> #ifdef CONFIG_AS_CRC32 >> asm ("crc32l %1,%0\n" : "+r" (crc) : "rm" (val)); > > Can you elaborate? > > Sorry, I need to ask here (even if it's a stupid question ;)) if this > change is safe to do; are referring to a cleanup or fixing a concrete > bug? The code is a modified version of the DPDK hash which you can find > in [1]. Arguments of the caller are in the correct order, afaik. > > [1] http://dpdk.org/browse/dpdk/tree/lib/librte_hash/rte_hash_crc.h Yes, that file appears to be correct: rte_hash_crc_4byte(uint32_t data, uint32_t init_val) as opposed to static inline u32 crc32_u32(u32 crc, u32 val) (quite obviously data <-> val and crc <-> init_val, supported by the second argument in each caller being named "seed"). Jan