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=-2.3 required=3.0 tests=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 2D68DC3A59B for ; Fri, 30 Aug 2019 17:45:52 +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 F2FF023426 for ; Fri, 30 Aug 2019 17:45:51 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="lfZeJ2fx" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org F2FF023426 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=arm.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+infradead-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=bombadil.20170209; h=Sender:Content-Type: Content-Transfer-Encoding:Cc:List-Subscribe:List-Help:List-Post:List-Archive: List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:Date:Message-ID:From: References:To:Subject:Reply-To:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=gwTlRVq2uMD8YN2ddn53TMYdELypSswxHWYHDCeOpdU=; b=lfZeJ2fxpTz1G3CuS5HnQma8d fk0iWzc6HacfanpGwBxQowbAARw/RmLTtBXAxcX3nFid1ZKc35CL8Ngfze2agkodseX+V9oNEJsFS B/OVYYETQWi7uKUY9OQGp3HooEcHO2d2eDn0Kvw2UiOyokuCuVqvFmDuCCn1Tjg7tbFtcsrekX17J 8sDggc4HHNU4TABWokwwTEzGQV+NJVBYEHsCj1O6t09xaxH00bsdPECecB7GU5603pGC/iGjADLX6 8se9f7UT3APajLGbwFH8H7DGmFzitAtQnhQdWN2I7Izl/4Wcuz205dJiRgEDNAiIrqha4YbatNMg6 u0orFOW/Q==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.92 #3 (Red Hat Linux)) id 1i3ky1-0003Pk-QP; Fri, 30 Aug 2019 17:45:45 +0000 Received: from foss.arm.com ([217.140.110.172]) by bombadil.infradead.org with esmtp (Exim 4.92 #3 (Red Hat Linux)) id 1i3kxz-0003P3-7e for linux-arm-kernel@lists.infradead.org; Fri, 30 Aug 2019 17:45:44 +0000 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 170BF337; Fri, 30 Aug 2019 10:45:42 -0700 (PDT) Received: from [10.1.197.57] (e110467-lin.cambridge.arm.com [10.1.197.57]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 719A83F718; Fri, 30 Aug 2019 10:45:37 -0700 (PDT) Subject: Re: [PATCH 6/7] arm64: tegra: Add DT node for T194 SMMU To: Krishna Reddy References: <1567118827-26358-1-git-send-email-vdumpa@nvidia.com> <1567118827-26358-7-git-send-email-vdumpa@nvidia.com> From: Robin Murphy Message-ID: Date: Fri, 30 Aug 2019 18:45:34 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.6.1 MIME-Version: 1.0 In-Reply-To: Content-Language: en-GB X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20190830_104543_322265_AE2E137D X-CRM114-Status: GOOD ( 14.00 ) 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: Timo Alho , Thierry Reding , Mikko Perttunen , "linux-kernel@vger.kernel.org" , "joro@8bytes.org" , "will.deacon@arm.com" , "iommu@lists.linux-foundation.org" , Pritesh Raithatha , "Thomas Zeng \(SW-TEGRA\)" , Sachin Nikam , "linux-tegra@vger.kernel.org" , Yu-Huan Hsu , Juha Tukkinen , Alexander Van Brunt , "linux-arm-kernel@lists.infradead.org" Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset="us-ascii"; Format="flowed" Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+infradead-linux-arm-kernel=archiver.kernel.org@lists.infradead.org On 30/08/2019 18:25, Krishna Reddy wrote: >>> + #global-interrupts = <1>; > >> Shouldn't that be 3? > > Interrupt line is shared between global and all context faults for each SMMU instance. > Nvidia implementation checks for both Global and context faults on each interrupt to an SMMU instance. > It can be either 1 or 3. If we make it 3, we need to add two more irq entries in node for context faults. The number of global interrupts has never been related to the number of context interrupts :/ > In the future, we can update arm-smmu.c to support shared interrupt line between global and all context faults. Clearly you have one combined interrupt output per SMMU - describing those as one global interrupt and the first two context bank interrupts respectively makes far less sense than calling them 3 global interrupts, not least because the latter is strictly true. Yes, the binding prevents us from describing the context bank interrupts for more than one instance, but at that point the fact that it *is* the combined output saves us - because the driver is aware of this specific integration it knows it can just register the "secondary" global interrupts as "secondary" context interrupts too. If we had separate IRQ lines per context bank per instance, then we'd have a really big problem and might have to redefine the binding, but as it is it happens to work out pretty neatly. Robin. _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel