From: Arnd Bergmann Subject: Re: [PATCH 1/7] asm-generic/io.h: add io{read,write}64 accessors Date: Thu, 05 May 2016 12:56:48 +0200 Message-ID: <4560398.4eHNWD6mu5@wuerfel> References: <1462382179-11889-1-git-send-email-horia.geanta@nxp.com> <16429831.u9JK7qO1GE@wuerfel> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7Bit Cc: Horia =?utf-8?B?R2VhbnTEgw==?= , Herbert Xu , "linux-crypto@vger.kernel.org" , "linux-arch@vger.kernel.org" , "linux-kernel@vger.kernel.org" , "David S. Miller" , Scott Wood , Alexandru Porosanu , Tudor Ambarus , Cristian Stoica , arcml , Noam Camus To: Vineet Gupta Return-path: Received: from mout.kundenserver.de ([212.227.126.133]:54701 "EHLO mout.kundenserver.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756675AbcEEK5j (ORCPT ); Thu, 5 May 2016 06:57:39 -0400 In-Reply-To: Sender: linux-crypto-owner@vger.kernel.org List-ID: On Thursday 05 May 2016 08:16:47 Vineet Gupta wrote: > Thx for noticing this Arnd and the heads up. Does the patch below look ok to you ? > > -----------> > rom b7e719831c389ab4fa338b2e2e7c0d1ff90dabb0 Mon Sep 17 00:00:00 2001 > From: Vineet Gupta > Date: Thu, 5 May 2016 13:32:34 +0530 > Subject: [PATCH] ARC: Add missing io barriers to io{read,write}{16,32}be() > > While reviewing a different change to asm-generic/io.h Arnd spotted that > ARC ioread32 and ioread32be both of which come from asm-generic versions > are not symmetrical in terms of calling the io barriers. > > generic ioread32 -> ARC readl() [ has barriers] > generic ioread32be -> __be32_to_cpu(__raw_readl()) [ lacks barriers] > > While generic ioread32be is being remediated to call readl(), that involves > a swab32(), causing double swaps on ioread32be() on Big Endian systems. > > So provide our versions of big endian IO accessors to ensure io barrier > calls while also keeping them optimal > > Suggested-by: Arnd Bergmann > Cc: stable@vger.kernel.org [4.2+] > Signed-off-by: Vineet Gupta Yes, that looks correct. We probably want this regardless of the change I proposed for the generic file, to avoid the double swap. Acked-by: Arnd Bergmann