From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-2.2 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS,URIBL_BLOCKED,USER_AGENT_MUTT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 3A355C31E45 for ; Thu, 13 Jun 2019 09:23:03 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 10D2F2147A for ; Thu, 13 Jun 2019 09:23:03 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="jueeQVJ0" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 10D2F2147A Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=arm.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+infradead-linux-arm-kernel=archiver.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20170209; h=Sender: Content-Transfer-Encoding:Content-Type:Cc:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:References: Message-ID:Subject:To:From:Date:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=x438AbKjN0AIqq6N41nVXybNXieOCD3FWAan6Fe/gYE=; b=jueeQVJ0uAhT54 tYNL+vWgq0PYRBkn0oU1xvRWyQ7zqiyR/IcrTYMTBpdis/q4GeJkYGcGkCI1WlDgaKlRe4RSFA5fl qNtlPVXjqbz5zHK2T8RPDWzf9cCNgRYonCRpoM1hKMtwjXQEozLxD5LEM4u4qTrThqvzcP62C7Iq9 8c4aB5OjYDwNRMRq7NDnRuqqE1umOr4Pry2yllCbrl9yr8M5bISy3oj5RNTxOFMeXMqTH+8XbiAI0 kaoXk0QmeyBPlSQvd+MyCfyENQs2pR0jUftbITL+t+YrElrwGh896NFRAOuQNqGrWsDOmWPLm/5FZ QqkTfHPk42GDYI5cld8w==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.92 #3 (Red Hat Linux)) id 1hbLwd-00019E-SR; Thu, 13 Jun 2019 09:22:55 +0000 Received: from foss.arm.com ([217.140.110.172]) by bombadil.infradead.org with esmtp (Exim 4.92 #3 (Red Hat Linux)) id 1hbLwY-00013W-SH for linux-arm-kernel@lists.infradead.org; Thu, 13 Jun 2019 09:22:54 +0000 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 6CDDE367; Thu, 13 Jun 2019 02:22:50 -0700 (PDT) Received: from fuggles.cambridge.arm.com (usa-sjc-imap-foss1.foss.arm.com [10.121.207.14]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 336CD3F694; Thu, 13 Jun 2019 02:22:49 -0700 (PDT) Date: Thu, 13 Jun 2019 10:22:47 +0100 From: Will Deacon To: Julien Grall Subject: Re: [PATCH v2 1/3] arm64/sve: Fix missing SVE/FPSIMD endianness conversions Message-ID: <20190613092247.GD17331@fuggles.cambridge.arm.com> References: <1560355234-25516-1-git-send-email-Dave.Martin@arm.com> <1560355234-25516-2-git-send-email-Dave.Martin@arm.com> <771b0099-9217-4e55-b73a-b03434c61655@arm.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <771b0099-9217-4e55-b73a-b03434c61655@arm.com> User-Agent: Mutt/1.11.1+86 (6f28e57d73f2) () X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20190613_022250_956789_EFC8B51F X-CRM114-Status: GOOD ( 15.78 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Peter Maydell , gdb@sourceware.org, Alan Hayward , Zhang Lei , Catalin Marinas , Alex =?iso-8859-1?Q?Benn=E9e?= , Dave Martin , linux-arm-kernel@lists.infradead.org Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+infradead-linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Wed, Jun 12, 2019 at 06:46:04PM +0100, Julien Grall wrote: > On 12/06/2019 17:00, Dave Martin wrote: > > The in-memory representation of SVE and FPSIMD registers is > > different: the FPSIMD V-registers are stored as single 128-bit > > host-endian values, whereas SVE registers are stored in an > > endianness-invariant byte order. > > > > This means that the two representations differ when running on a > > big-endian host. But we blindly copy data from one representation > > to another when converting between the two, resulting in the > > register contents being unintentionally byteswapped in certain > > situations. Currently this can be triggered by the first SVE > > instruction after a syscall, for example (though the potential > > trigger points may vary in future). > > > > So, fix the conversion functions fpsimd_to_sve(), sve_to_fpsimd() > > and sve_sync_from_fpsimd_zeropad() to swab where appropriate. > > > > There is no common swahl128() or swab128() that we could use here. > > Maybe it would be worth making this generic, but for now add a > > simple local hack. > > > > Since the byte order differences are exposed in ABI, also clarify > > the docuentation. > > NIT: s/docuentation/documentation/ > > Although, it is probably too late to fix this one as Will already took the patch. I actually spotted (and fixed) that one when I committed the patch, but I missed the others. Given that this is top of the fixes branch, I can probably just fold these in. Will _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel