From patchwork Thu Jul 23 16:52:44 2015 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Mark Rutland X-Patchwork-Id: 6855001 Return-Path: X-Original-To: patchwork-linux-arm@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork2.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.136]) by patchwork2.web.kernel.org (Postfix) with ESMTP id 518C1C05AC for ; Thu, 23 Jul 2015 16:59:02 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 01CC420735 for ; Thu, 23 Jul 2015 16:59:01 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.9]) (using TLSv1.2 with cipher AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id E9C80205EF for ; Thu, 23 Jul 2015 16:58:59 +0000 (UTC) Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.80.1 #2 (Red Hat Linux)) id 1ZIJmT-0006MK-N6; Thu, 23 Jul 2015 16:55:37 +0000 Received: from foss.arm.com ([217.140.101.70]) by bombadil.infradead.org with esmtp (Exim 4.80.1 #2 (Red Hat Linux)) id 1ZIJki-0005uG-Ka for linux-arm-kernel@lists.infradead.org; Thu, 23 Jul 2015 16:53:49 +0000 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.72.51.249]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id ACB3D3DB; Thu, 23 Jul 2015 09:53:42 -0700 (PDT) Received: from leverpostej.cambridge.arm.com (usa-sjc-imap-foss1.foss.arm.com [10.72.51.249]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPA id BDA443F510; Thu, 23 Jul 2015 09:53:26 -0700 (PDT) From: Mark Rutland To: devicetree@vger.kernel.org Subject: [PATCH 2/3] Docs: dt: Add PCI MSI map bindings Date: Thu, 23 Jul 2015 17:52:44 +0100 Message-Id: <1437670365-20704-3-git-send-email-mark.rutland@arm.com> X-Mailer: git-send-email 1.9.1 In-Reply-To: <1437670365-20704-1-git-send-email-mark.rutland@arm.com> References: <1437670365-20704-1-git-send-email-mark.rutland@arm.com> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20150723_095348_693312_BB92A091 X-CRM114-Status: GOOD ( 17.86 ) X-Spam-Score: -8.1 (--------) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.20 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Mark Rutland , lorenzo.pieralisi@arm.com, arnd@arndb.de, marc.zyngier@arm.com, will.deacon@arm.com, linux-kernel@vger.kernel.org, ddaney@caviumnetworks.com, iommu@lists.linux-foundation.org, tirumalesh.chalamarla@caviumnetworks.com, laurent.pinchart@ideasonboard.com, thunder.leizhen@huawei.com, treding@nvidia.com, robin.murphy@arm.com, linux-arm-kernel@lists.infradead.org, majun258@huawei.com MIME-Version: 1.0 Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org X-Spam-Status: No, score=-5.4 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_MED, RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=unavailable version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP Currently msi-parent is used by a few bindings to describe the relationship between a PCI root complex and a single MSI controller, but this property does not have a generic binding document. Additionally, msi-parent is insufficient to describe more complex relationships between MSI controllers and devices under a root complex, where devices may be able to target multiple MSI controllers, or where MSI controllers use (non-probeable) sideband information to distinguish devices. This patch adds a generic binding for mapping PCI devices to MSI controllers. This document covers msi-parent, and a new msi-map property (specific to PCI*) which may be used to map devices (identified by their Requester ID) to sideband data for each MSI controller that they may target. Signed-off-by: Mark Rutland Acked-by: David Daney --- Documentation/devicetree/bindings/pci/pci-msi.txt | 220 ++++++++++++++++++++++ 1 file changed, 220 insertions(+) create mode 100644 Documentation/devicetree/bindings/pci/pci-msi.txt diff --git a/Documentation/devicetree/bindings/pci/pci-msi.txt b/Documentation/devicetree/bindings/pci/pci-msi.txt new file mode 100644 index 0000000..9b3cc81 --- /dev/null +++ b/Documentation/devicetree/bindings/pci/pci-msi.txt @@ -0,0 +1,220 @@ +This document describes the generic device tree binding for describing the +relationship between PCI devices and MSI controllers. + +Each PCI device under a root complex is uniquely identified by its Requester ID +(AKA RID). A Requester ID is a triplet of a Bus number, Device number, and +Function number. + +For the purpose of this document, when treated as a numeric value, a RID is +formatted such that: + +* Bits [15:8] are the Bus number. +* Bits [7:3] are the Device number. +* Bits [2:0] are the Function number. +* Any other bits required for padding must be zero. + +MSIs may be distinguished in part through the use of sideband data accompanying +writes. In the case of PCI devices, this sideband data may be derived from the +Requester ID. A mechanism is required to associate a device with both the MSI +controllers it can address, and the sideband data that will be associated with +its writes to those controllers. + +For generic MSI bindings, see +Documentation/devicetree/bindings/interrupt-controller/msi.txt. + + +PCI root complex +================ + +Optional properties +------------------- + +- msi-map: Maps a Requester ID to an MSI controller and associated + msi-specifier data. The property is an arbitrary number of tuples of + (rid-base,msi-controller,msi-base,length), where: + + * rid-base is a single cell describing the first RID matched by the entry. + + * msi-controller is a single phandle to an MSI controller + + * msi-base is an msi-specifier describing the msi-specifier produced for the + first RID matched by the entry. + + * length is a single cell describing how many consecutive RIDs are matched + following the rid-base. + + Any RID r in the interval [rid-base, rid-base + length) is associated with + the listed msi-controller, with the msi-specifier (r - rid-base + msi-base). + +- msi-map-mask: A mask to be applied to each Requester ID prior to being mapped + to an msi-specifier per the msi-map property. + +- msi-parent: Describes the MSI parent of the root complex itself. Where + the root complex and MSI controller do not pass sideband data with MSI + writes, this property may be used to describe the MSI controller(s) + used by PCI devices under the root complex, if defined as such in the + binding for the root complex. + + +Example (1) +=========== + +/ { + #address-cells = <1>; + #size-cells = <1>; + + msi: msi-controller@a { + reg = <0xa 0x1>; + compatible = "vendor,some-controller"; + msi-controller; + #msi-cells = <1>; + }; + + pci: pci@f { + reg = <0xf 0x1>; + compatible = "vendor,pcie-root-complex"; + device_type = "pci"; + + /* + * The sideband data provided to the MSI controller is + * the RID, identity-mapped. + */ + msi-map = <0x0 &msi_a 0x0 0x10000>, + }; +}; + + +Example (2) +=========== + +/ { + #address-cells = <1>; + #size-cells = <1>; + + msi: msi-controller@a { + reg = <0xa 0x1>; + compatible = "vendor,some-controller"; + msi-controller; + #msi-cells = <1>; + }; + + pci: pci@f { + reg = <0xf 0x1>; + compatible = "vendor,pcie-root-complex"; + device_type = "pci"; + + /* + * The sideband data provided to the MSI controller is + * the RID, masked to only the device and function bits. + */ + msi-map = <0x0 &msi_a 0x0 0x100>, + msi-map-mask = <0xff> + }; +}; + + +Example (3) +=========== + +/ { + #address-cells = <1>; + #size-cells = <1>; + + msi: msi-controller@a { + reg = <0xa 0x1>; + compatible = "vendor,some-controller"; + msi-controller; + #msi-cells = <1>; + }; + + pci: pci@f { + reg = <0xf 0x1>; + compatible = "vendor,pcie-root-complex"; + device_type = "pci"; + + /* + * The sideband data provided to the MSI controller is + * the RID, but the high bit of the bus number is + * ignored. + */ + msi-map = <0x0000 &msi 0x0000 0x8000>, + <0x8000 &msi 0x0000 0x8000>; + }; +}; + + +Example (4) +=========== + +/ { + #address-cells = <1>; + #size-cells = <1>; + + msi: msi-controller@a { + reg = <0xa 0x1>; + compatible = "vendor,some-controller"; + msi-controller; + #msi-cells = <1>; + }; + + pci: pci@f { + reg = <0xf 0x1>; + compatible = "vendor,pcie-root-complex"; + device_type = "pci"; + + /* + * The sideband data provided to the MSI controller is + * the RID, but the high bit of the bus number is + * negated. + */ + msi-map = <0x0000 &msi 0x8000 0x8000>, + <0x8000 &msi 0x0000 0x8000>; + }; +}; + + +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>; + }; +};