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 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 smtp.lore.kernel.org (Postfix) with ESMTPS id 42E4FC433F5 for ; Tue, 31 May 2022 16:20:40 +0000 (UTC) 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=mB3fcvH/hBPgCDLQhY1O7SRlc0DUoL6au1+1cKEWUPI=; b=gnu4Qvv8IMxQAT 15eu5XJbiAA+Pnmb2pd5SgwaMKhQ9umqIO/KoWFcumR9Car/WjAlMoSBTnA5gSjAZHakgNYiwYNYi Qappxh0Pj6VzSy3u4kFTppkhzB0jx/W/6nWRhIQ/C1vzHyalrAi9URhbb9/+77CV2Jpv1hhClxuuI FguAab177ujmMPLECMHCd3ZEvpJxZg+GEP1sf8o1aDX74DwXGmOmMXf4e8h+szkUXGKGdFCJh30K/ sYnm12pssI8osQcs7/einz8AprBbxbxOibY5tmCB1GfdU/WUnvKE0jpJmtYqcCG1R3/ABe/X982Q9 9xmKHww/fR1YWQfI4Weg==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1nw4aZ-00Bked-Su; Tue, 31 May 2022 16:19:24 +0000 Received: from dfw.source.kernel.org ([2604:1380:4641:c500::1]) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1nw4aW-00Bkdn-MP for linux-arm-kernel@lists.infradead.org; Tue, 31 May 2022 16:19:21 +0000 Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 0CA5B604F5; Tue, 31 May 2022 16:19:19 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 19D2CC385A9; Tue, 31 May 2022 16:19:14 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1654013958; bh=C7JqPHYdDIfIV1hFpEuC1J6B7QEItv7CaH7EVzTRasE=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=c7uCs1jy8TG74D+Nj32f4BthpKKQvR+72bqpZXJZDojOu/Ri4D//ChSLI2vkj884B k35ZMlm5UJfSwDAtNkaERyfhCvFvZXDpAthbHc4HkQ7W03zyQPBFHoKp7stXu318GC 5VM4zAwxH7TtP3LB1s/bzGOH8e9Lq2vjBfscQPE3016J1EHU4Nqji9R8xT3oCFM7zr HGeViJPNgdB51Kq1EoXhNEyKiBj2Ya4ArkH46ly3m4pxnzPNywvMEU2/pM4mGnrLa2 psUMVuVTbOqTI27e5Hs7HKH8fpB6H+JgeeIjB7UTyNZkdBfYSv+/9JLpw/iQ0xyJfZ r4XR05x5qaAjg== Date: Tue, 31 May 2022 17:19:11 +0100 From: Will Deacon To: Rob Clark Cc: Konrad Dybcio , ~postmarketos/upstreaming@lists.sr.ht, linux-arm-msm , Bjorn Andersson , "moderated list:ARM/FREESCALE IMX / MXC ARM ARCHITECTURE" , "list@263.net:IOMMU DRIVERS , Joerg Roedel ," , Martin Botka , AngeloGioacchino Del Regno , Marijn Suijten , jamipkettunen@somainline.org, Andy Gross , Joerg Roedel , Rob Herring , Krzysztof Kozlowski , Robin Murphy , "open list:OPEN FIRMWARE AND FLATTENED DEVICE TREE BINDINGS" , Linux Kernel Mailing List Subject: Re: [PATCH 1/6] iommu/qcom: Use the asid read from device-tree if specified Message-ID: <20220531161910.GE25502@willie-the-truck> References: <20220527212901.29268-1-konrad.dybcio@somainline.org> <20220527212901.29268-2-konrad.dybcio@somainline.org> <20220531154631.GA25502@willie-the-truck> 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-20220531_091920_806997_972B5B06 X-CRM114-Status: GOOD ( 25.15 ) 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 Tue, May 31, 2022 at 09:15:22AM -0700, Rob Clark wrote: > On Tue, May 31, 2022 at 8:46 AM Will Deacon wrote: > > > > On Fri, May 27, 2022 at 11:28:56PM +0200, Konrad Dybcio wrote: > > > From: AngeloGioacchino Del Regno > > > > > > As specified in this driver, the context banks are 0x1000 apart. > > > Problem is that sometimes the context number (our asid) does not > > > match this logic and we end up using the wrong one: this starts > > > being a problem in the case that we need to send TZ commands > > > to do anything on a specific context. > > > > I don't understand this. The ASID is a software construct, so it shouldn't > > matter what we use. If it does matter, then please can you explain why? The > > fact that the context banks are 0x1000 apart seems unrelated. > > I think the connection is that mapping from ctx bank to ASID is 1:1 But in what sense? How is the ASID used beyond a tag in the TLB? The commit message hints at "TZ commands" being a problem. I'm not doubting that this is needed to make the thing work, I just don't understand why. Will _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel