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=-5.5 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,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 9C873C4361B for ; Wed, 9 Dec 2020 20:09:07 +0000 (UTC) Received: from merlin.infradead.org (merlin.infradead.org [205.233.59.134]) (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 47E4121D46 for ; Wed, 9 Dec 2020 20:09:07 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 47E4121D46 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+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=merlin.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=gMeY6RF0DwU1x7L/caWcGv8XZEapbZtLaQSwT3YYLEs=; b=noKWs22fANU9kB6VyAA2KIcZx aijii46y38ZflnT92NIz9WADjH+/0FFP4N5Ncxa4vkx6iDGIUnc2zLln91xpkXoxv9P2BhheGOyfm Mct2NRq2j9jnaRhmdR/ELE2xwatMvrvoUIux2Vb4xdkyR2P4Une6t0HnvKRT8L95uc8I4SPTDb4Ze iszq3CyvIFNlJXZc5dhbUzbCFhsiJ9YiG/DtT9np1yPXxXl1dtg3fP7mtulPebLrMlYnUWpiIq2Xb HVHL1UYJpc+AeYHx02f1F6jbHYIAKzzQuzpNI1k80IyIyXP2Pe8dRRojScpO52jAc2WhtESqCsGnS qOlgSM+mw==; Received: from localhost ([::1] helo=merlin.infradead.org) by merlin.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1kn5kh-0000cL-Ka; Wed, 09 Dec 2020 20:07:55 +0000 Received: from mail.kernel.org ([198.145.29.99]) by merlin.infradead.org with esmtps (Exim 4.92.3 #3 (Red Hat Linux)) id 1kn5ke-0000ba-S9 for linux-arm-kernel@lists.infradead.org; Wed, 09 Dec 2020 20:07:53 +0000 Date: Wed, 9 Dec 2020 20:07:42 +0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1607544468; bh=RwtPuIYol40kyDSA4Jk5Z51qfhMMaedTf5Q+9030Dtg=; h=From:To:Cc:Subject:References:In-Reply-To:From; b=WjTRYZErNqmS7HSgHfZJvcGSudj6QQ/BoaTG0mpwRSde3DtGgpDV/4KNjtqyEp4N+ 2SFusGgwv6iZgTJCRLikjacas6bF+LBJeIO0GTHgZ4EvroAXOfs4Of64brnCCAiEL/ NS4gCLeuTP+i1+ZCKXLR4nYVtPRM5cuymwlc4I/UEatT/px6/DX1ax9KzE7bxb22m0 D2BA2bOs49gRHUGRFhScPxtDW0b+fk74I1a1oBmW5xKntFJsqo1uuXPCsQPbHQGka9 x7PsjSp1nxXDMK0hxlRclxlkbHpcjvFPaN5DcSyltP56QCuHoa53NMckH935C/JDn1 FhQiUpC9ttZAw== From: Will Deacon To: Krishna Reddy Subject: Re: [PATCH v10 10/13] iommu/arm-smmu-v3: Check for SVA features Message-ID: <20201209200741.GA8992@willie-the-truck> References: <20200918101852.582559-1-jean-philippe@linaro.org> <20200918101852.582559-11-jean-philippe@linaro.org> <753bcd76c21c4ea98ef1d4e492db01f4@huawei.com> <20200924101340.GC170808@myrica> <47b244b99f284790b82b2c0a968ba830@huawei.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: 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-20201209_150753_012034_29C5FCF1 X-CRM114-Status: GOOD ( 14.23 ) 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: Jean-Philippe Brucker , Yu-Huan Hsu , Suzuki K Poulose , "catalin.marinas@arm.com" , Alistair Popple , Sachin Nikam , "fenghua.yu@intel.com" , Pritesh Raithatha , Vikram Sethi , "linux-mm@kvack.org" , "iommu@lists.linux-foundation.org" , Shameerali Kolothum Thodi , Jason Gunthorpe , "zhangfei.gao@linaro.org" , "robin.murphy@arm.com" , "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+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Wed, Dec 09, 2020 at 07:49:09PM +0000, Krishna Reddy wrote: > > > Why is BTM mandated for SVA? I couldn't find this requirement in > > > SMMU spec (Sorry if I missed it or this got discussed earlier). But > > > if performance is the > > only concern here, > > > is it better just to allow it with a warning rather than limiting > > > SMMUs without > > BTM? > > > > It's a performance concern and requires to support multiple > > configurations, but the spec allows it. Are there SMMUs without BTM > > that need it? > > The Tegra Next Generation SOC uses arm-smmu-v3, but it doesn't have support for BTM. > Do you have plan to get your earlier patch to handle invalidate > notifications into upstream sometime soon? Is that a limitation of the SMMU implementation, the interconnect or the integration? Will _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel