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=-5.6 required=3.0 tests=BAYES_00,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 AB33CC433EF for ; Sat, 18 Sep 2021 05:21:26 +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 6BFB3610C9 for ; Sat, 18 Sep 2021 05:21:26 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.1 mail.kernel.org 6BFB3610C9 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=lst.de Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:References: Message-ID:Subject:Cc: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=j32Ro3k4H+8A8PVempEwign8zrt0sQ4UCCplP7is/hc=; b=EjlaXMV6z52rRf frKMLe8TXthO05BXaUmA03EoIlbkq7pqnNrkrZh2d7ygzBOjKEXDtu5sN9LLiE5zFp2ezHxD75Qhj 5u+HwrlmMFgiN3maJsSMYneymygpBKgeEkT9+m8gKZRrCzW7lntv6mfaiYRDJ5zh+azZ4MrmsAH4N T0XDMImOOzDB7DFMkKHbrAzHQ31YccIHLqX5BDQFbYjjezcZWPHb7MnCiLHwHSsUpu/8DacypVBXz PLGm7YuuVXLSLtFOZtdqoyXZblm016HuJsyUe3BXoZR8DiiVjKm/gxe2smou3jNMxYWt7TJ5Ow5fx zbDKXs/K5w7F5cLuVX4A==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1mRSkW-00FQWT-Vs; Sat, 18 Sep 2021 05:18:53 +0000 Received: from verein.lst.de ([213.95.11.211]) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1mRSkT-00FQVr-9d for linux-arm-kernel@lists.infradead.org; Sat, 18 Sep 2021 05:18:51 +0000 Received: by verein.lst.de (Postfix, from userid 2407) id A44E867357; Sat, 18 Sep 2021 07:18:43 +0200 (CEST) Date: Sat, 18 Sep 2021 07:18:43 +0200 From: Christoph Hellwig To: Mike Rapoport Cc: Catalin Marinas , David Hildenbrand , Robin Murphy , Alex Bee , Will Deacon , Andrew Morton , Anshuman Khandual , Linux Kernel Mailing List , linux-mm@kvack.org, Linux ARM , Christoph Hellwig Subject: Re: [BUG 5.14] arm64/mm: dma memory mapping fails (in some cases) Message-ID: <20210918051843.GA16104@lst.de> References: <20210824173741.GC623@arm.com> <0908ce39-7e30-91fa-68ef-11620f9596ae@arm.com> <60a11eba-2910-3b5f-ef96-97d4556c1596@redhat.com> <20210825102044.GA3420@arm.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.17 (2007-11-01) X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20210917_221849_538142_0CFB35CA X-CRM114-Status: GOOD ( 13.22 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Sat, Sep 18, 2021 at 12:22:47AM +0300, Mike Rapoport wrote: > I did some digging and it seems that the most "generic" way to check if a > page is in RAM is page_is_ram(). It's not 100% bullet proof as it'll give > false negatives for architectures that do not register "System RAM", but > those are not using dma_map_resource() anyway and, apparently, never would. The downside of page_is_ram is that it looks really expensiv for something done at dma mapping time. _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel