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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 5EE67C001B0 for ; Wed, 9 Aug 2023 22:57:43 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229988AbjHIW5m (ORCPT ); Wed, 9 Aug 2023 18:57:42 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:45752 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229581AbjHIW5m (ORCPT ); Wed, 9 Aug 2023 18:57:42 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 38DF0E52; Wed, 9 Aug 2023 15:57:41 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id B353364BAC; Wed, 9 Aug 2023 22:57:40 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id AB10AC433C8; Wed, 9 Aug 2023 22:57:39 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1691621860; bh=Ql3to1IJwpgeRfj699MkiCOXh7sBIqi9/cjNmbZWUTk=; h=Date:From:To:Cc:Subject:In-Reply-To:From; b=RUHWRltkPA12Kj2DgZ8R48fvhAXnicqOstELHQsrAvyvWUBELc4u1PdBAZPAyguWy WChH7oCMVkyfBE9uTULypcNdxec1eisFBS3m/KWOIgxWWYscvPTXVIHPzWvu4zUIUn bOCK6lLH62yMUBP8j4n40IO6q+EcPoZupQPms4vnT6Ks927I96c+kbuInvK9eeubNT xudYXUo6Jit2aI9Wb2qrwiuK6NB00kO3EeDQvFXNkJUYCU8UIvmtMp2L/yUMb/IAEY 4ER4xpVL4TLFxWMMp/nLlr0NVPe5vKlejv1zI+7pP1wMIk+7qHEvG0G6S50GoYw3cP lcNd77Zpvhz1Q== Date: Wed, 9 Aug 2023 17:57:38 -0500 From: Bjorn Helgaas To: Rob Herring Cc: linux-pci@vger.kernel.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, robh@kernel.org, max.zhen@amd.com, sonal.santan@amd.com, stefano.stabellini@xilinx.com, Lizhi Hou Subject: Re: [PATCH V12 0/5] Generate device tree node for pci devices Message-ID: <20230809225738.GA11578@bhelgaas> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <1690564018-11142-1-git-send-email-lizhi.hou@amd.com> Precedence: bulk List-ID: X-Mailing-List: devicetree@vger.kernel.org Rob, I'm assuming this series is yours; I've acked the drivers/pci parts. Let me know if otherwise. On Fri, Jul 28, 2023 at 10:06:53AM -0700, Lizhi Hou wrote: > This patch series introduces OF overlay support for PCI devices which > primarily addresses two use cases. First, it provides a data driven method > to describe hardware peripherals that are present in a PCI endpoint and > hence can be accessed by the PCI host. Second, it allows reuse of a OF > compatible driver -- often used in SoC platforms -- in a PCI host based > system. > > There are 2 series devices rely on this patch: > > 1) Xilinx Alveo Accelerator cards (FPGA based device) > 2) Microchip LAN9662 Ethernet Controller > > Please see: https://lore.kernel.org/lkml/20220427094502.456111-1-clement.leger@bootlin.com/ > > Normally, the PCI core discovers PCI devices and their BARs using the > PCI enumeration process. However, the process does not provide a way to > discover the hardware peripherals that are present in a PCI device, and > which can be accessed through the PCI BARs. Also, the enumeration process > does not provide a way to associate MSI-X vectors of a PCI device with the > hardware peripherals that are present in the device. PCI device drivers > often use header files to describe the hardware peripherals and their > resources as there is no standard data driven way to do so. This patch > series proposes to use flattened device tree blob to describe the > peripherals in a data driven way. Based on previous discussion, using > device tree overlay is the best way to unflatten the blob and populate > platform devices. To use device tree overlay, there are three obvious > problems that need to be resolved. > > First, we need to create a base tree for non-DT system such as x86_64. A > patch series has been submitted for this: > https://lore.kernel.org/lkml/20220624034327.2542112-1-frowand.list@gmail.com/ > https://lore.kernel.org/lkml/20220216050056.311496-1-lizhi.hou@xilinx.com/ > > Second, a device tree node corresponding to the PCI endpoint is required > for overlaying the flattened device tree blob for that PCI endpoint. > Because PCI is a self-discoverable bus, a device tree node is usually not > created for PCI devices. This series adds support to generate a device > tree node for a PCI device which advertises itself using PCI quirks > infrastructure. > > Third, we need to generate device tree nodes for PCI bridges since a child > PCI endpoint may choose to have a device tree node created. > > This patch series is made up of three patches. > > The first patch is adding OF interface to create or destroy OF node > dynamically. > > The second patch introduces a kernel option, CONFIG_PCI_DYNAMIC_OF_NODES. > When the option is turned on, the kernel will generate device tree nodes > for all PCI bridges unconditionally. The patch also shows how to use the > PCI quirks infrastructure, DECLARE_PCI_FIXUP_FINAL to generate a device > tree node for a device. Specifically, the patch generates a device tree > node for Xilinx Alveo U50 PCIe accelerator device. The generated device > tree nodes do not have any property. > > The third patch adds basic properties ('reg', 'compatible' and > 'device_type') to the dynamically generated device tree nodes. More > properties can be added in the future. > > Here is the example of device tree nodes generated within the ARM64 QEMU. > > # lspci -t > -[0000:00]-+-00.0 > +-01.0 > +-03.0-[01-03]----00.0-[02-03]----00.0-[03]----00.0 > +-03.1-[04]-- > \-04.0-[05-06]----00.0-[06]-- > > Without CONFIG_PCI_DYNAMIC_OF_NODES > > # tree /sys/firmware/devicetree/base/pcie@10000000/ > /sys/firmware/devicetree/base/pcie@10000000/ > |-- #address-cells > |-- #interrupt-cells > |-- #size-cells > |-- bus-range > |-- compatible > |-- device_type > |-- dma-coherent > |-- interrupt-map > |-- interrupt-map-mask > |-- linux,pci-domain > |-- msi-map > |-- name > |-- ranges > `-- reg > > With CONFIG_PCI_DYNAMIC_OF_NODES > > # tree /sys/firmware/devicetree/base/pcie@10000000/ > /sys/firmware/devicetree/base/pcie@10000000/ > |-- #address-cells > |-- #interrupt-cells > |-- #size-cells > |-- bus-range > |-- compatible > |-- device_type > |-- dma-coherent > |-- interrupt-map > |-- interrupt-map-mask > |-- linux,pci-domain > |-- msi-map > |-- name > |-- pci@3,0 > | |-- #address-cells > | |-- #interrupt-cells > | |-- #size-cells > | |-- bus-range > | |-- compatible > | |-- device_type > | |-- interrupt-map > | |-- interrupt-map-mask > | |-- interrupts > | |-- pci@0,0 > | | |-- #address-cells > | | |-- #interrupt-cells > | | |-- #size-cells > | | |-- bus-range > | | |-- compatible > | | |-- device_type > | | |-- interrupt-map > | | |-- interrupt-map-mask > | | |-- pci@0,0 > | | | |-- #address-cells > | | | |-- #interrupt-cells > | | | |-- #size-cells > | | | |-- bus-range > | | | |-- compatible > | | | |-- dev@0,0 > | | | | |-- #address-cells > | | | | |-- #size-cells > | | | | |-- compatible > | | | | |-- ranges > | | | | `-- reg > | | | |-- device_type > | | | |-- interrupt-map > | | | |-- interrupt-map-mask > | | | |-- ranges > | | | `-- reg > | | |-- ranges > | | `-- reg > | |-- ranges > | `-- reg > |-- pci@3,1 > | |-- #address-cells > | |-- #interrupt-cells > | |-- #size-cells > | |-- bus-range > | |-- compatible > | |-- device_type > | |-- interrupt-map > | |-- interrupt-map-mask > | |-- interrupts > | |-- ranges > | `-- reg > |-- pci@4,0 > | |-- #address-cells > | |-- #interrupt-cells > | |-- #size-cells > | |-- bus-range > | |-- compatible > | |-- device_type > | |-- interrupt-map > | |-- interrupt-map-mask > | |-- pci@0,0 > | | |-- #address-cells > | | |-- #interrupt-cells > | | |-- #size-cells > | | |-- bus-range > | | |-- compatible > | | |-- device_type > | | |-- interrupt-map > | | |-- interrupt-map-mask > | | |-- interrupts > | | |-- ranges > | | `-- reg > | |-- ranges > | `-- reg > |-- ranges > `-- reg > > Changes since v11: > - Create interrupt related properties > > Changes since v10: > - Remove 'dynamic' property > > Changes since v9: > - Introduce 'dynamic' property to identify dynamically generated device tree > node for PCI device > - Added 'bus-range' property to remove dtc warnings > - Minor code review fixes > > Changes since v8: > - Added patches to create unit test to verifying address translation > The test relies on QEMU PCI Test Device, please see > https://github.com/houlz0507/xoclv2/blob/pci-dt-0329/pci-dt-patch-0329/README > for test setup > - Minor code review fixes > > Changes since v7: > - Modified dynamic node creation interfaces > - Added unittest for new added interfaces > > Changes since v6: > - Removed single line wrapper functions > - Added Signed-off-by Clément Léger > > Changes since v5: > - Fixed code review comments > - Fixed incorrect 'ranges' and 'reg' properties > > Changes since RFC v4: > - Fixed code review comments > > Changes since RFC v3: > - Split the Xilinx Alveo U50 PCI quirk to a separate patch > - Minor changes in commit description and code comment > > Changes since RFC v2: > - Merged patch 3 with patch 2 > - Added OF interfaces of_changeset_add_prop_* and use them to create > properties. > - Added '#address-cells', '#size-cells' and 'ranges' properties. > > Changes since RFC v1: > - Added one patch to create basic properties. > - To move DT related code out of PCI subsystem, replaced of_node_alloc() > with of_create_node()/of_destroy_node() > > Lizhi Hou (5): > of: dynamic: Add interfaces for creating device node dynamically > PCI: Create device tree node for bridge > PCI: Add quirks to generate device tree node for Xilinx Alveo U50 > of: overlay: Extend of_overlay_fdt_apply() to specify the target node > of: unittest: Add pci_dt_testdrv pci driver > > drivers/of/dynamic.c | 164 ++++++++ > drivers/of/overlay.c | 42 ++- > drivers/of/unittest-data/Makefile | 3 +- > .../of/unittest-data/overlay_pci_node.dtso | 22 ++ > drivers/of/unittest.c | 211 ++++++++++- > drivers/pci/Kconfig | 12 + > drivers/pci/Makefile | 1 + > drivers/pci/bus.c | 2 + > drivers/pci/of.c | 79 ++++ > drivers/pci/of_property.c | 355 ++++++++++++++++++ > drivers/pci/pci.h | 12 + > drivers/pci/quirks.c | 12 + > drivers/pci/remove.c | 1 + > include/linux/of.h | 25 +- > 14 files changed, 926 insertions(+), 15 deletions(-) > create mode 100644 drivers/of/unittest-data/overlay_pci_node.dtso > create mode 100644 drivers/pci/of_property.c > > -- > 2.34.1 >