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 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 5C487C433F5 for ; Thu, 30 Sep 2021 05:46:47 +0000 (UTC) Received: from smtp1.osuosl.org (smtp1.osuosl.org [140.211.166.138]) (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 0AC0A617E5 for ; Thu, 30 Sep 2021 05:46:46 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.1 mail.kernel.org 0AC0A617E5 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=lst.de Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=lists.linux-foundation.org Received: from localhost (localhost [127.0.0.1]) by smtp1.osuosl.org (Postfix) with ESMTP id D1BDB8405D; Thu, 30 Sep 2021 05:46:46 +0000 (UTC) X-Virus-Scanned: amavisd-new at osuosl.org Received: from smtp1.osuosl.org ([127.0.0.1]) by localhost (smtp1.osuosl.org [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id M8gJREN6JAhy; Thu, 30 Sep 2021 05:46:46 +0000 (UTC) Received: from lists.linuxfoundation.org (lf-lists.osuosl.org [140.211.9.56]) by smtp1.osuosl.org (Postfix) with ESMTPS id C2D788405B; Thu, 30 Sep 2021 05:46:45 +0000 (UTC) Received: from lf-lists.osuosl.org (localhost [127.0.0.1]) by lists.linuxfoundation.org (Postfix) with ESMTP id 9A634C000F; Thu, 30 Sep 2021 05:46:45 +0000 (UTC) Received: from smtp3.osuosl.org (smtp3.osuosl.org [IPv6:2605:bc80:3010::136]) by lists.linuxfoundation.org (Postfix) with ESMTP id B1B73C000D for ; Thu, 30 Sep 2021 05:46:43 +0000 (UTC) Received: from localhost (localhost [127.0.0.1]) by smtp3.osuosl.org (Postfix) with ESMTP id 8CAD6607A9 for ; Thu, 30 Sep 2021 05:46:43 +0000 (UTC) X-Virus-Scanned: amavisd-new at osuosl.org Received: from smtp3.osuosl.org ([127.0.0.1]) by localhost (smtp3.osuosl.org [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id 3o3GMvtdTj34 for ; Thu, 30 Sep 2021 05:46:43 +0000 (UTC) X-Greylist: from auto-whitelisted by SQLgrey-1.8.0 Received: from verein.lst.de (verein.lst.de [213.95.11.211]) by smtp3.osuosl.org (Postfix) with ESMTPS id CA4116073D for ; Thu, 30 Sep 2021 05:46:42 +0000 (UTC) Received: by verein.lst.de (Postfix, from userid 2407) id 3107468AFE; Thu, 30 Sep 2021 07:46:38 +0200 (CEST) Date: Thu, 30 Sep 2021 07:46:37 +0200 From: Christoph Hellwig To: Mike Rapoport Subject: Re: [PATCH 1/2] dma-mapping: remove bogus test for pfn_valid from dma_map_resource Message-ID: <20210930054637.GA22287@lst.de> References: <20210930013039.11260-1-rppt@kernel.org> <20210930013039.11260-2-rppt@kernel.org> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20210930013039.11260-2-rppt@kernel.org> User-Agent: Mutt/1.5.17 (2007-11-01) Cc: Will Deacon , Anshuman Khandual , Catalin Marinas , David Hildenbrand , Alex Bee , Linux Kernel Mailing List , iommu@lists.linux-foundation.org, Andrew Morton , Mike Rapoport , Robin Murphy , Christoph Hellwig , linux-arm-kernel@lists.infradead.org X-BeenThere: iommu@lists.linux-foundation.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: Development issues for Linux IOMMU support List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: iommu-bounces@lists.linux-foundation.org Sender: "iommu" On Thu, Sep 30, 2021 at 04:30:38AM +0300, Mike Rapoport wrote: > From: Mike Rapoport > > dma_map_resource() uses pfn_valid() to ensure the range is not RAM. > However, pfn_valid() only checks for availability of the memory map for a > PFN but it does not ensure that the PFN is actually backed by RAM. > > As dma_map_resource() is the only method in DMA mapping APIs that has this > check, simply drop the pfn_valid() test from dma_map_resource(). > > Link: https://lore.kernel.org/all/20210824173741.GC623@arm.com/ > Signed-off-by: Mike Rapoport We'll lose a bit of a sanity check with this, but given the problems it caused: Reviewed-by: Christoph Hellwig _______________________________________________ iommu mailing list iommu@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/iommu