Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752558AbbG0JQ5 (ORCPT ); Mon, 27 Jul 2015 05:16:57 -0400 Received: from foss.arm.com ([217.140.101.70]:51558 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750883AbbG0JQ4 (ORCPT ); Mon, 27 Jul 2015 05:16:56 -0400 Date: Mon, 27 Jul 2015 10:16:17 +0100 From: Mark Rutland To: "Chalamarla, Tirumalesh" Cc: "devicetree@vger.kernel.org" , "linux-kernel@vger.kernel.org" , "iommu@lists.linux-foundation.org" , linux-arm-kernel , Will Deacon , Marc Zyngier , Robin Murphy , Lorenzo Pieralisi , Arnd Bergmann , "treding@nvidia.com" , "Daney, David" , "majun258@huawei.com" , "thunder.leizhen@huawei.com" , "laurent.pinchart@ideasonboard.com" Subject: Re: [PATCH 2/3] Docs: dt: Add PCI MSI map bindings Message-ID: <20150727091535.GA9169@leverpostej> References: <1437670365-20704-1-git-send-email-mark.rutland@arm.com> <1437670365-20704-3-git-send-email-mark.rutland@arm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1783 Lines: 62 > > +Example (5) > > +=========== > > + > > +/ { > > + #address-cells = <1>; > > + #size-cells = <1>; > > + > > + msi_a: msi-controller@a { > > + reg = <0xa 0x1>; > > + compatible = "vendor,some-controller"; > > + msi-controller; > > + #msi-cells = <1>; > > + }; > > + > > + msi_b: msi-controller@b { > > + reg = <0xb 0x1>; > > + compatible = "vendor,some-controller"; > > + msi-controller; > > + #msi-cells = <1>; > > + }; > > + > > + msi_c: msi-controller@c { > > + reg = <0xc 0x1>; > > + compatible = "vendor,some-controller"; > > + msi-controller; > > + #msi-cells = <1>; > > + }; > > + > > + pci: pci@c { > > + reg = <0xf 0x1>; > > + compatible = "vendor,pcie-root-complex"; > > + device_type = "pci"; > > + > > + /* > > + * The sideband data provided to MSI controller a is the > > + * RID, but the high bit of the bus number is negated. > > + * The sideband data provided to MSI controller b is the > > + * RID, identity-mapped. > > + * MSI controller c is not addressable. > > + */ > > + msi-map = <0x0000 &msi_a 0x8000 0x08000>, > > + <0x8000 &msi_a 0x0000 0x08000>, > > + <0x0000 &msi_b 0x0000 0x10000>; > > + }; > > they can be identical right? like > <0x8000 &msi_a 0x0000 0x08000>, > <0x8000 &msi_b 0x0000 0x08000>; In general that would be valid, yes. In this case two entries are required for MSI controller a because the high bit passed to it is negated. This does not occur for MSI controller b, so it only requires a single entry to describe the transformation. Thanks, Mark. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/