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=-8.5 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,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 937B6C2D0E8 for ; Wed, 1 Apr 2020 03:08:47 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 5F4C62077D for ; Wed, 1 Apr 2020 03:08:47 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=ti.com header.i=@ti.com header.b="svH23gQL" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731619AbgDADIn (ORCPT ); Tue, 31 Mar 2020 23:08:43 -0400 Received: from fllv0015.ext.ti.com ([198.47.19.141]:35828 "EHLO fllv0015.ext.ti.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1731592AbgDADIn (ORCPT ); Tue, 31 Mar 2020 23:08:43 -0400 Received: from lelv0265.itg.ti.com ([10.180.67.224]) by fllv0015.ext.ti.com (8.15.2/8.15.2) with ESMTP id 03138XVe083327; Tue, 31 Mar 2020 22:08:33 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ti.com; s=ti-com-17Q1; t=1585710513; bh=QGxTvKSuMAvjN97JC/+YbiSUgKIoFS5hHdeQwmmihL8=; h=Subject:To:CC:References:From:Date:In-Reply-To; b=svH23gQL6L6RQllYde7vA4qFa7cNAFQdHgdJdaiBLrMlkuQE1Yo9V2VhWBQ93wen5 L37uEHT+EYnDmp/RTAGWkNhQMmGgsrB1422HGGLqXNyiFsVCnDszZcTLXZ/dK6mFhQ 7u6+8Afdaj/M6DWcbOD6u6OClBCE//jfthIobAeA= Received: from DFLE112.ent.ti.com (dfle112.ent.ti.com [10.64.6.33]) by lelv0265.itg.ti.com (8.15.2/8.15.2) with ESMTPS id 03138XDk076010 (version=TLSv1.2 cipher=AES256-GCM-SHA384 bits=256 verify=FAIL); Tue, 31 Mar 2020 22:08:33 -0500 Received: from DFLE114.ent.ti.com (10.64.6.35) by DFLE112.ent.ti.com (10.64.6.33) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256_P256) id 15.1.1847.3; Tue, 31 Mar 2020 22:08:33 -0500 Received: from fllv0040.itg.ti.com (10.64.41.20) by DFLE114.ent.ti.com (10.64.6.35) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256_P256) id 15.1.1847.3 via Frontend Transport; Tue, 31 Mar 2020 22:08:33 -0500 Received: from [10.250.133.232] (ileax41-snat.itg.ti.com [10.172.224.153]) by fllv0040.itg.ti.com (8.15.2/8.15.2) with ESMTP id 03138RCe023502; Tue, 31 Mar 2020 22:08:30 -0500 Subject: Re: [PATCH 1/3] dt-bindings: PCI: cadence: Deprecate inbound/outbound specific bindings To: Rob Herring CC: Tom Joseph , Lorenzo Pieralisi , Andrew Murray , Bjorn Helgaas , Mark Rutland , , , References: <20200327104727.4708-1-kishon@ti.com> <20200327104727.4708-2-kishon@ti.com> <20200330160142.GA6259@bogus> <2a18a228-9248-24a8-c9cd-a041c62aa381@ti.com> <20200331164529.GA32149@bogus> From: Kishon Vijay Abraham I Message-ID: <2985575e-e079-2a8d-bf3e-b7efb7291fc3@ti.com> Date: Wed, 1 Apr 2020 08:38:26 +0530 User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:68.0) Gecko/20100101 Thunderbird/68.6.0 MIME-Version: 1.0 In-Reply-To: <20200331164529.GA32149@bogus> Content-Type: text/plain; charset="utf-8" Content-Language: en-US Content-Transfer-Encoding: 7bit X-EXCLAIMER-MD-CONFIG: e1e8a2fd-e40a-4ac6-ac9b-f7e9cc9ee180 Sender: linux-pci-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org Hi Rob, On 3/31/2020 10:15 PM, Rob Herring wrote: > On Tue, Mar 31, 2020 at 09:08:12AM +0530, Kishon Vijay Abraham I wrote: >> Hi Rob, >> >> On 3/30/2020 9:31 PM, Rob Herring wrote: >>> On Fri, Mar 27, 2020 at 04:17:25PM +0530, Kishon Vijay Abraham I wrote: >>>> Deprecate cdns,max-outbound-regions and cdns,no-bar-match-nbits for >>>> host mode as both these could be derived from "ranges" and "dma-ranges" >>>> property. "cdns,max-outbound-regions" property would still be required >>>> for EP mode. >>>> >>>> Signed-off-by: Kishon Vijay Abraham I >>>> --- >>>> .../bindings/pci/cdns,cdns-pcie-ep.yaml | 2 +- >>>> .../bindings/pci/cdns,cdns-pcie-host.yaml | 3 +-- >>>> .../devicetree/bindings/pci/cdns-pcie-ep.yaml | 25 +++++++++++++++++++ >>>> .../bindings/pci/cdns-pcie-host.yaml | 10 ++++++++ >>>> .../devicetree/bindings/pci/cdns-pcie.yaml | 8 ------ >>>> 5 files changed, 37 insertions(+), 11 deletions(-) >>>> create mode 100644 Documentation/devicetree/bindings/pci/cdns-pcie-ep.yaml >>>> >>>> diff --git a/Documentation/devicetree/bindings/pci/cdns,cdns-pcie-ep.yaml b/Documentation/devicetree/bindings/pci/cdns,cdns-pcie-ep.yaml >>>> index 2996f8d4777c..50ce5d79d2c7 100644 >>>> --- a/Documentation/devicetree/bindings/pci/cdns,cdns-pcie-ep.yaml >>>> +++ b/Documentation/devicetree/bindings/pci/cdns,cdns-pcie-ep.yaml >>>> @@ -10,7 +10,7 @@ maintainers: >>>> - Tom Joseph >>>> >>>> allOf: >>>> - - $ref: "cdns-pcie.yaml#" >>>> + - $ref: "cdns-pcie-ep.yaml#" >>>> - $ref: "pci-ep.yaml#" >>>> >>>> properties: >>>> diff --git a/Documentation/devicetree/bindings/pci/cdns,cdns-pcie-host.yaml b/Documentation/devicetree/bindings/pci/cdns,cdns-pcie-host.yaml >>>> index cabbe46ff578..84a8f095d031 100644 >>>> --- a/Documentation/devicetree/bindings/pci/cdns,cdns-pcie-host.yaml >>>> +++ b/Documentation/devicetree/bindings/pci/cdns,cdns-pcie-host.yaml >>>> @@ -45,8 +45,6 @@ examples: >>>> #size-cells = <2>; >>>> bus-range = <0x0 0xff>; >>>> linux,pci-domain = <0>; >>>> - cdns,max-outbound-regions = <16>; >>>> - cdns,no-bar-match-nbits = <32>; >>>> vendor-id = <0x17cd>; >>>> device-id = <0x0200>; >>>> >>>> @@ -57,6 +55,7 @@ examples: >>>> >>>> ranges = <0x02000000 0x0 0x42000000 0x0 0x42000000 0x0 0x1000000>, >>>> <0x01000000 0x0 0x43000000 0x0 0x43000000 0x0 0x0010000>; >>>> + dma-ranges = <0x02000000 0x0 0x0 0x0 0x0 0x1 0x00000000>; >>>> >>>> #interrupt-cells = <0x1>; >>>> >>>> diff --git a/Documentation/devicetree/bindings/pci/cdns-pcie-ep.yaml b/Documentation/devicetree/bindings/pci/cdns-pcie-ep.yaml >>>> new file mode 100644 >>>> index 000000000000..6150a7a7bdbf >>>> --- /dev/null >>>> +++ b/Documentation/devicetree/bindings/pci/cdns-pcie-ep.yaml >>>> @@ -0,0 +1,25 @@ >>>> +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause) >>>> +%YAML 1.2 >>>> +--- >>>> +$id: "http://devicetree.org/schemas/pci/cdns-pcie-ep.yaml#" >>>> +$schema: "http://devicetree.org/meta-schemas/core.yaml#" >>>> + >>>> +title: Cadence PCIe Device >>>> + >>>> +maintainers: >>>> + - Tom Joseph >>>> + >>>> +allOf: >>>> + - $ref: "cdns-pcie.yaml#" >>>> + >>>> +properties: >>>> + cdns,max-outbound-regions: >>>> + description: maximum number of outbound regions >>>> + allOf: >>>> + - $ref: /schemas/types.yaml#/definitions/uint32 >>>> + minimum: 1 >>>> + maximum: 32 >>>> + default: 32 >>> >>> I have a feeling that as the PCI endpoint binding evolves this won't be >>> necessary. I can see a common need to define the number of BARs for an >>> endpoint and then this will again just be error checking. >> >> For every buffer given by the host, we have to create a new outbound >> translation. If there are no outbound regions, we have to report the error to >> the endpoint function driver. At-least for reporting the error, we'd need to >> have this binding no? > > But isn't the endpoint defined to have some number of BARs? The PCI host > doesn't decide that. cdns,max-outbound-regions defined here doesn't configure the BARs. BARs provide an interface for the host to access the endpoints memory. IOW for BARs we configure the inbound address translation unit. cdns,max-outbound-regions is used while configuring the outbound address translation unit. Outbound regions are used while the endpoint access host memory and in that path endpoint BARs doesn't come. > >>> >>> What's the result if you write to a non-existent region in register >>> CDNS_PCIE_AT_OB_REGION_PCI_ADDR0/1? If the register is non-existent and >>> doesn't abort, you could detect this instead. >> >> I'm not sure if we should ever try to write to a non-existent register though >> the behavior could be different in different platforms. IMHO maximum number of >> outbound regions is a HW property and is best described in device tree. > > AIUI, PCI defines non-existent (config space) registers to return all > 1s. Not sure if this register is in PCI config space or the host SoC bus > (e.g. AXI). It seems PCI bridges get done both ways from what I've seen. All of that is correct for the Host or RC. However here cdns,max-outbound-regions is an endpoint specific property (defined only in cdns-pcie-ep.yaml) and is useful while configuring OB address translation unit for the endpoint to access host memory. Thanks Kishon