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=-1.1 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_PASS autolearn=ham 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 AB11AC43142 for ; Tue, 31 Jul 2018 18:22:02 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 3E5EA20857 for ; Tue, 31 Jul 2018 18:22:02 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="hmLqGjGq" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 3E5EA20857 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=gmail.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729963AbeGaUDc (ORCPT ); Tue, 31 Jul 2018 16:03:32 -0400 Received: from mail-io0-f194.google.com ([209.85.223.194]:35753 "EHLO mail-io0-f194.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729644AbeGaUDb (ORCPT ); Tue, 31 Jul 2018 16:03:31 -0400 Received: by mail-io0-f194.google.com with SMTP id w11-v6so13869587iob.2 for ; Tue, 31 Jul 2018 11:21:59 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=subject:to:cc:references:from:message-id:date:user-agent :mime-version:in-reply-to:content-language:content-transfer-encoding; bh=2HMehfdDkjGDNTUdHCh9ypmEMD7butM7h2R8hS34Vn4=; b=hmLqGjGqFk/iKk7sPZW3zGnqc+tJYas8rYykhicDd/OpFTiybuqIBF5wSaLEgCQbNC HhbEHjsQzTfjcWN7sCk5zan4RNCoGOo2SC4285VM17BUnhT6eXuCfe2B0cDp7TUsedWh svaoxAjHvNMBAlYfPwexYgMpjNZ2mpiOKqCb31nSlzxR/UMZ9Fo0OMdyaqb8+QAgibo2 yoltEjRb2dBAUEaoe8CAr6IO/UT2XBu3hwGXVikyC0ltSkMccdUOiISFSPhmVwIusZcp sCWzWjaicu30uJxUpyWTCWDzMyEBfKeUR4zlyzpo+Na6jfWv3EaMf0bhwN/yHyTD9Ujb vApw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:subject:to:cc:references:from:message-id:date :user-agent:mime-version:in-reply-to:content-language :content-transfer-encoding; bh=2HMehfdDkjGDNTUdHCh9ypmEMD7butM7h2R8hS34Vn4=; b=kOgDlcvscp/IURtVc/CMnSAcHI3pDGx64mqWZBF9pxcXZNtp1TImU4OUSFQ8/QJDVf WkTmwegCYeb300ErlBB/0zsP1P+UFpgmxD2mEPA4wj+KCsdke+wEjqCCNDTCHmy5jcuv x5a2JNSLOMGcsuc306VJTlkufqMU9Svt43RaEPJ19vz6UczQ8LjEQfcY4K8qDHEi7Fba 5aNWXP6EWGeIykAyzS1eri7YUwu/pa1m3AAcXPy2Nfce4LcUhTb6wsLb+DCplW/xQi4O BFN+46ei8ug8+Ta3ffFrnzQ632OMh3tqmIQktRlOeBtnWa3tTxG3uBPvA7PTZQvnBTls fRKQ== X-Gm-Message-State: AOUpUlEOffqIW4AJj42gPa3je4NVmtjGmQ646+X92vcQVinxODR09fsR 6nCSlLnm8EU6SjdkyAOehQMi72cmXsM= X-Google-Smtp-Source: AAOMgpenyIpJJ4WLkuAjFEil4rvMrJGOTh98VqLDHS+C8Cps6IV4zAGWIC59n3zjo0HYgFShWmDf1A== X-Received: by 2002:a6b:bbc1:: with SMTP id l184-v6mr686897iof.83.1533061318844; Tue, 31 Jul 2018 11:21:58 -0700 (PDT) Received: from [10.0.2.15] ([72.138.96.106]) by smtp.gmail.com with ESMTPSA id i3-v6sm1727831iti.40.2018.07.31.11.21.57 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Tue, 31 Jul 2018 11:21:58 -0700 (PDT) Subject: Re: [RESEND PATCH 0/6] rapidio: move Kconfig menu definition to subsystem To: Russell King - ARM Linux , Alexei Colin Cc: Andrew Morton , John Paul Walters , Catalin Marinas , Arnd Bergmann , Will Deacon , Ralf Baechle , Paul Burton , Alexander Sverdlin , Benjamin Herrenschmidt , Paul Mackerras , Thomas Gleixner , Peter Anvin , Matt Porter , x86@kernel.org, linuxppc-dev@lists.ozlabs.org, linux-mips@linux-mips.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org References: <20180731142954.30345-1-acolin@isi.edu> <20180731155909.GO17271@n2100.armlinux.org.uk> From: Alex Bounine Message-ID: <1f427e4c-3fb8-769a-efb6-db64afd4617a@gmail.com> Date: Tue, 31 Jul 2018 14:21:57 -0400 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.9.1 MIME-Version: 1.0 In-Reply-To: <20180731155909.GO17271@n2100.armlinux.org.uk> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2018-07-31 11:59 AM, Russell King - ARM Linux wrote: > For the thread associated with this patch set, a review of a previous > patch for ARM posted last Tuesday on this subject asked a series of > questions about the PCI-nature of this. The review has not been > responded to. We are dealing with this now. More appropriate to do it this time than before having reworked set. > If it is inappropriate to offer RapidIO for any architecture that > happens to has PCI, then it is inappropriate to offer it for any > ARM machine that happens to have PCI. It is completely appropriate to use RapidIO on any architecture that has PCI/PCIe using existing PCIe-to-SRIO host bridges. Works well with Marvell and NVIDIA boards. Confusion here is caused by the fact that there are ARM and non-ARM devices that offer on-chip RapidIO host controllers as well as PCIe. E.g. TI Keystone/KeystoneII, FSL 85xx/86xx, Xilinx and Altera FPGAs with ARM cores, Cavium on MIPS. In most cases external buses are configurable and we have to address possible combinations. I already posted some explanation in response to your earlier comment. > In light of the lack of explanation on this point so far, I'm naking > the ARM part of this series for now. > Explanations posted. > I also think that the HAS_RAPIDIO thing is misleading and needs > sorting out (as I've mentioned in other emails, including the one > I refer to above) before rapidio becomes available more widely. > Highly likely it is used right now in a base station of mobile operator near you :) > On Tue, Jul 31, 2018 at 10:29:48AM -0400, Alexei Colin wrote: >> Resending the patchset from prior submission: >> https://lkml.org/lkml/2018/7/30/911 >> >> The only change are the Cc tags in all patches now include the mailing >> lists for all affected architectures, and patch 1/6 (which adds the menu >> item to RapdidIO subsystem Kconfig) is CCed to all maintainers who are >> getting this cover letter. The cover letter has been updated with >> explanations to points raised in the feedback. >> >> >> >> The top-level Kconfig entry for RapidIO subsystem is currently >> duplicated in several architecture-specific Kconfig files. This set of >> patches does two things: >> >> 1. Move the Kconfig menu definition into the RapidIO subsystem and >> remove the duplicate definitions from arch Kconfig files. >> >> 2. Enable RapidIO Kconfig menu entry for arm and arm64 architectures, >> where it was not enabled before. I tested that subsystem and drivers >> build successfully for both architectures, and tested that the modules >> load on a custom arm64 Qemu model. >> >> For all architectures, RapidIO menu should be offered when either: >> (1) The platform has a PCI bus (which host a RapidIO module on the bus). >> (2) The platform has a RapidIO IP block (connected to a system bus, e.g. >> AXI on ARM). In this case, 'select HAS_RAPIDIO' should be added to the >> 'config ARCH_*' menu entry for the SoCs that offer the IP block. >> >> Prior to this patchset, different architectures used different criteria: >> * powerpc: (1) and (2) >> * mips: (1) and (2) after recent commit into next that added (2): >> https://www.linux-mips.org/archives/linux-mips/2018-07/msg00596.html >> fc5d988878942e9b42a4de5204bdd452f3f1ce47 >> 491ec1553e0075f345fbe476a93775eabcbc40b6 >> * x86: (1) >> * arm,arm64: none (RapidIO menus never offered) >> >> This set of architectures are the ones that implement support for >> RapidIO as system bus. On some platforms RapidIO can be the only system >> bus available replacing PCI/PCIe. As it is done now, RapidIO is >> configured in "Bus Options" (x86/PPC) or "Bus Support" (ARMs) sub-menu >> and from system configuration option it should be kept this way. >> Current location of RAPIDIO configuration option is familiar to users of >> PowerPC and x86 platforms, and is similarly available in some ARM >> manufacturers kernel code trees. (Alex Bounine) >> >> HAS_RAPIDIO is not enabled unconditionally, because HAS_RAPIDIO option >> is intended for SOCs that have built in SRIO controllers, like TI >> KeyStoneII or FPGAs. Because RapidIO subsystem core is required during >> RapidIO port driver initialization, having separate option allows us to >> control available build options for RapidIO core and port driver (bool >> vs. tristate) and disable module option if port driver is configured as >> built-in. (Alex Bounine) >> >> Responses to feedback from prior submission (thanks for the reviews!): >> http://lists.infradead.org/pipermail/linux-arm-kernel/2018-July/593347.html >> http://lists.infradead.org/pipermail/linux-arm-kernel/2018-July/593349.html >> >> Changelog: >> * Moved Kconfig entry into RapidIO subsystem instead of duplicating >> >> In the current patchset, I took the approach of adding '|| PCI' to the >> depends in the subsystem. I did try the alterantive approach mentioned >> in the reviews for v1 of this patch, where the subsystem Kconfig does >> not add a '|| PCI' and each per-architecture Kconfig has to add a >> 'select HAS_RAPIDIO if PCI' and SoCs with IP blocks have to also add >> 'select HAS_RAPIDIO'. This works too but requires each architecture's >> Kconfig to add the line for RapidIO (whereas current approach does not >> require that involvement) and also may create a false impression that >> the dependency on PCI is strict. >> >> We appreciate the suggestion for also selecting the RapdiIO subsystem for >> compilation with COMPILE_TEST, but hope to address it in a separate >> patchset, localized to the subsystem, since it will need to change >> depends on all drivers, not just on the top level, and since this >> patch now spans multiple architectures. >> >> Alexei Colin (6): >> rapidio: define top Kconfig menu in driver subtree >> x86: factor out RapidIO Kconfig menu >> powerpc: factor out RapidIO Kconfig menu entry >> mips: factor out RapidIO Kconfig entry >> arm: enable RapidIO menu in Kconfig >> arm64: enable RapidIO menu in Kconfig >> >> arch/arm/Kconfig | 2 ++ >> arch/arm64/Kconfig | 2 ++ >> arch/mips/Kconfig | 11 ----------- >> arch/powerpc/Kconfig | 13 +------------ >> arch/x86/Kconfig | 8 -------- >> drivers/rapidio/Kconfig | 15 +++++++++++++++ >> 6 files changed, 20 insertions(+), 31 deletions(-) >> >> -- >> 2.18.0 >> >