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=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 D525BC33C99 for ; Tue, 7 Jan 2020 10:55:08 +0000 (UTC) Received: from fraxinus.osuosl.org (smtp4.osuosl.org [140.211.166.137]) (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 86F3C20678 for ; Tue, 7 Jan 2020 10:55:07 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 86F3C20678 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=lst.de Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=iommu-bounces@lists.linux-foundation.org Received: from localhost (localhost [127.0.0.1]) by fraxinus.osuosl.org (Postfix) with ESMTP id 82EFA84CE6; Tue, 7 Jan 2020 10:55:07 +0000 (UTC) X-Virus-Scanned: amavisd-new at osuosl.org Received: from fraxinus.osuosl.org ([127.0.0.1]) by localhost (.osuosl.org [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id CWbIX8_Bg_as; Tue, 7 Jan 2020 10:55:06 +0000 (UTC) Received: from lists.linuxfoundation.org (lf-lists.osuosl.org [140.211.9.56]) by fraxinus.osuosl.org (Postfix) with ESMTP id 6E33C84CC2; Tue, 7 Jan 2020 10:55:06 +0000 (UTC) Received: from lf-lists.osuosl.org (localhost [127.0.0.1]) by lists.linuxfoundation.org (Postfix) with ESMTP id 5209EC1D82; Tue, 7 Jan 2020 10:55:06 +0000 (UTC) Received: from silver.osuosl.org (smtp3.osuosl.org [140.211.166.136]) by lists.linuxfoundation.org (Postfix) with ESMTP id 5BC86C0881 for ; Tue, 7 Jan 2020 10:55:05 +0000 (UTC) Received: from localhost (localhost [127.0.0.1]) by silver.osuosl.org (Postfix) with ESMTP id 4A1EA20338 for ; Tue, 7 Jan 2020 10:55:05 +0000 (UTC) X-Virus-Scanned: amavisd-new at osuosl.org Received: from silver.osuosl.org ([127.0.0.1]) by localhost (.osuosl.org [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id wkZJuJHWTbA5 for ; Tue, 7 Jan 2020 10:55:04 +0000 (UTC) X-Greylist: from auto-whitelisted by SQLgrey-1.7.6 Received: from verein.lst.de (verein.lst.de [213.95.11.211]) by silver.osuosl.org (Postfix) with ESMTPS id D3B812011A for ; Tue, 7 Jan 2020 10:55:03 +0000 (UTC) Received: by verein.lst.de (Postfix, from userid 2407) id DE1FD68AFE; Tue, 7 Jan 2020 11:54:58 +0100 (CET) Date: Tue, 7 Jan 2020 11:54:58 +0100 From: Christoph Hellwig To: Robin Murphy Subject: Re: [rfc] dma-mapping: preallocate unencrypted DMA atomic pool Message-ID: <20200107105458.GA3139@lst.de> References: <3213a6ac-5aad-62bc-bf95-fae8ba088b9e@arm.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <3213a6ac-5aad-62bc-bf95-fae8ba088b9e@arm.com> User-Agent: Mutt/1.5.17 (2007-11-01) Cc: "Lendacky, Thomas" , "Singh, Brijesh" , "Grimm, Jon" , baekhw@google.com, "linux-kernel@vger.kernel.org" , "iommu@lists.linux-foundation.org" , David Rientjes , Christoph Hellwig 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 Mon, Jan 06, 2020 at 05:34:00PM +0000, Robin Murphy wrote: > On 01/01/2020 1:54 am, David Rientjes via iommu wrote: >> Christoph, Thomas, is something like this (without the diagnosic >> information included in this patch) acceptable for these allocations? >> Adding expansion support when the pool is half depleted wouldn't be *that* >> hard. >> >> Or are there alternatives we should consider? Thanks! > > Are there any platforms which require both non-cacheable remapping *and* > unencrypted remapping for distinct subsets of devices? > > If not (and I'm assuming there aren't, because otherwise this patch is > incomplete in covering only 2 of the 3 possible combinations), then > couldn't we keep things simpler by just attributing both properties to the > single "atomic pool" on the basis that one or the other will always be a > no-op? In other words, basically just tweaking the existing "!coherent" > tests to "!coherent || force_dma_unencrypted()" and doing > set_dma_unencrypted() unconditionally in atomic_pool_init(). I think that would make most sense. _______________________________________________ iommu mailing list iommu@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/iommu