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=-8.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=unavailable 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 21F63C433E0 for ; Fri, 22 May 2020 09:42:51 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 0D317207CB for ; Fri, 22 May 2020 09:42:51 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728425AbgEVJmu (ORCPT ); Fri, 22 May 2020 05:42:50 -0400 Received: from foss.arm.com ([217.140.110.172]:60234 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728212AbgEVJmu (ORCPT ); Fri, 22 May 2020 05:42:50 -0400 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 5D4FC30E; Fri, 22 May 2020 02:42:49 -0700 (PDT) Received: from [10.57.2.168] (unknown [10.57.2.168]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 11AEE3F305; Fri, 22 May 2020 02:42:46 -0700 (PDT) Subject: Re: [PATCH 09/12] dt-bindings: arm: fsl: Add msi-map device-tree binding for fsl-mc bus To: Rob Herring , Lorenzo Pieralisi Cc: devicetree@vger.kernel.org, Catalin Marinas , Will Deacon , Diana Craciun , PCI , Sudeep Holla , "Rafael J. Wysocki" , Makarand Pawagi , linux-acpi@vger.kernel.org, Linux IOMMU , Marc Zyngier , Hanjun Guo , Bjorn Helgaas , "moderated list:ARM/FREESCALE IMX / MXC ARM ARCHITECTURE" References: <20200521130008.8266-1-lorenzo.pieralisi@arm.com> <20200521130008.8266-10-lorenzo.pieralisi@arm.com> From: Robin Murphy Message-ID: Date: Fri, 22 May 2020 10:42:45 +0100 User-Agent: Mozilla/5.0 (Windows NT 10.0; rv:68.0) Gecko/20100101 Thunderbird/68.8.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-GB Content-Transfer-Encoding: 7bit Sender: linux-acpi-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-acpi@vger.kernel.org On 2020-05-22 00:10, Rob Herring wrote: > On Thu, May 21, 2020 at 7:00 AM Lorenzo Pieralisi > wrote: >> >> From: Laurentiu Tudor >> >> The existing bindings cannot be used to specify the relationship >> between fsl-mc devices and GIC ITSes. >> >> Add a generic binding for mapping fsl-mc devices to GIC ITSes, using >> msi-map property. >> >> Signed-off-by: Laurentiu Tudor >> Cc: Rob Herring >> --- >> .../devicetree/bindings/misc/fsl,qoriq-mc.txt | 30 +++++++++++++++++-- >> 1 file changed, 27 insertions(+), 3 deletions(-) >> >> diff --git a/Documentation/devicetree/bindings/misc/fsl,qoriq-mc.txt b/Documentation/devicetree/bindings/misc/fsl,qoriq-mc.txt >> index 9134e9bcca56..b0813b2d0493 100644 >> --- a/Documentation/devicetree/bindings/misc/fsl,qoriq-mc.txt >> +++ b/Documentation/devicetree/bindings/misc/fsl,qoriq-mc.txt >> @@ -18,9 +18,9 @@ same hardware "isolation context" and a 10-bit value called an ICID >> the requester. >> >> The generic 'iommus' property is insufficient to describe the relationship >> -between ICIDs and IOMMUs, so an iommu-map property is used to define >> -the set of possible ICIDs under a root DPRC and how they map to >> -an IOMMU. >> +between ICIDs and IOMMUs, so the iommu-map and msi-map properties are used >> +to define the set of possible ICIDs under a root DPRC and how they map to >> +an IOMMU and a GIC ITS respectively. >> >> For generic IOMMU bindings, see >> Documentation/devicetree/bindings/iommu/iommu.txt. >> @@ -28,6 +28,9 @@ Documentation/devicetree/bindings/iommu/iommu.txt. >> For arm-smmu binding, see: >> Documentation/devicetree/bindings/iommu/arm,smmu.yaml. >> >> +For GICv3 and GIC ITS bindings, see: >> +Documentation/devicetree/bindings/interrupt-controller/arm,gic-v3.yaml. >> + >> Required properties: >> >> - compatible >> @@ -119,6 +122,15 @@ Optional properties: >> associated with the listed IOMMU, with the iommu-specifier >> (i - icid-base + iommu-base). >> >> +- msi-map: Maps an ICID to a GIC ITS and associated iommu-specifier >> + data. >> + >> + The property is an arbitrary number of tuples of >> + (icid-base,iommu,iommu-base,length). > > I'm confused because the example has GIC ITS phandle, not an IOMMU. > > What is an iommu-base? Right, I was already halfway through writing a reply to say that all the copy-pasted "iommu" references here should be using the terminology from the pci-msi.txt binding instead. >> + >> + Any ICID in the interval [icid-base, icid-base + length) is >> + associated with the listed GIC ITS, with the iommu-specifier >> + (i - icid-base + iommu-base). >> Example: >> >> smmu: iommu@5000000 { >> @@ -128,6 +140,16 @@ Example: >> ... >> }; >> >> + gic: interrupt-controller@6000000 { >> + compatible = "arm,gic-v3"; >> + ... >> + its: gic-its@6020000 { >> + compatible = "arm,gic-v3-its"; >> + msi-controller; >> + ... >> + }; >> + }; >> + >> fsl_mc: fsl-mc@80c000000 { >> compatible = "fsl,qoriq-mc"; >> reg = <0x00000008 0x0c000000 0 0x40>, /* MC portal base */ >> @@ -135,6 +157,8 @@ Example: >> msi-parent = <&its>; Side note: is it right to keep msi-parent here? It rather implies that the MC itself has a 'native' Device ID rather than an ICID, which I believe is not strictly true. Plus it's extra-confusing that it doesn't specify an ID either way, since that makes it look like the legacy PCI case that gets treated implicitly as an identity msi-map, which makes no sense at all to combine with an actual msi-map. >> /* define map for ICIDs 23-64 */ >> iommu-map = <23 &smmu 23 41>; >> + /* define msi map for ICIDs 23-64 */ >> + msi-map = <23 &its 23 41>; > > Seeing 23 twice is odd. The numbers to the right of 'its' should be an > ITS number space. On about 99% of systems the values in the SMMU Stream ID and ITS Device ID spaces are going to be the same. Nobody's going to bother carrying *two* sets of sideband data across the interconnect if they don't have to ;) Robin. >> #address-cells = <3>; >> #size-cells = <1>; >> >> -- >> 2.26.1 >> > _______________________________________________ > iommu mailing list > iommu@lists.linux-foundation.org > https://lists.linuxfoundation.org/mailman/listinfo/iommu >