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=-2.3 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS,USER_AGENT_SANE_1 autolearn=no 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 B4F59C54FCB for ; Wed, 22 Apr 2020 13:56:53 +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 705CA2082E for ; Wed, 22 Apr 2020 13:56:53 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="BavOXijj" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 705CA2082E 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=sn06nomnluGbpuOyM/5YFLe78MnmTb2K7ahzt6W1QFY=; b=BavOXijjV+8CAm RQt2DU/xPTlkbt26Q0izBgfv5+FiF9VleIMlTaedNt55NaqknIgasCr+xm3QzOLaHfBiDpC6QV/0u sFOx/1SYMZubQLwBn1eBSBYE4DQLuE+wCXTA7tQ6TjlnA4um00M5OtGBsmdMDDKQZL5JJz0HG/2li FitJtFq+IV/rHHvJF2D+5AWdek25Tor3O49QpcOq5l3EfICcCMnaq/GeRVigVUw5Lxhal1ulHtRJT f5L3ReE++L1tdbyRZK7bApbKCwrkmCZsu7orenVX3NZny6PQZdkSfuM1EdF+LF/euxR18aTbwWGzl VlFuFVl4qtnfz/ovXCtA==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1jRFrw-0004eB-8b; Wed, 22 Apr 2020 13:56:52 +0000 Received: from foss.arm.com ([217.140.110.172]) by bombadil.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1jRFrt-0004cS-Lj for linux-arm-kernel@lists.infradead.org; Wed, 22 Apr 2020 13:56:50 +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 0CBFC30E; Wed, 22 Apr 2020 06:56:47 -0700 (PDT) Received: from gaia (unknown [172.31.20.19]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 6426A3F68F; Wed, 22 Apr 2020 06:56:45 -0700 (PDT) Date: Wed, 22 Apr 2020 14:56:43 +0100 From: Catalin Marinas To: Russell King - ARM Linux admin Subject: Re: [PATCH] arm32: fix flushcache syscall with device address Message-ID: <20200422135642.GD3585@gaia> References: <1587456514-61156-1-git-send-email-tiantao6@hisilicon.com> <20200421081239.GA15439@willie-the-truck> <20200421121651.000009f0@Huawei.com> <20200421165515.GF25745@shell.armlinux.org.uk> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20200421165515.GF25745@shell.armlinux.org.uk> User-Agent: Mutt/1.10.1 (2018-07-13) X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20200422_065649_754816_27774907 X-CRM114-Status: GOOD ( 14.38 ) 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: Will Deacon , gregkh@linuxfoundation.org, linux-kernel@vger.kernel.org, linuxarm@huawei.com, James Morse , linux-arm-kernel@lists.infradead.org, Jonathan Cameron , Tian Tao , tglx@linutronix.de, info@metux.net, allison@lohutok.net 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 Tue, Apr 21, 2020 at 05:55:16PM +0100, Russell King wrote: > On Tue, Apr 21, 2020 at 05:50:22PM +0100, James Morse wrote: > > (Subject Nit: arm64, as that is what your patch modifies) > > That is irrelevent. This is a compatibility interface which is supposed > to reflect the arm32 implementation. Augmenting a compatibility > interface to do more than what it's counterpart that it's supposed to > be compatible with is senseless. > > The API concerned is an ARM32 API which is expected to only be used > for ensuring I/D cache coherency, it is not for DMA. > > Augmenting it on ARM64 for DMA is senseless. I fully agree. I don't see any valid reason why this needs to be fixed. It looks like some broken user process trying to do cache maintenance to PoU on the mapped PCIe BAR (either inadvertently or for the wrong reasons). -- Catalin _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel