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=-21.0 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,MENTIONS_GIT_HOSTING,NICE_REPLY_A, 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 880B5C4338F for ; Mon, 9 Aug 2021 16:26:58 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 4111960F11 for ; Mon, 9 Aug 2021 16:26:58 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.1 mail.kernel.org 4111960F11 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=arm.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:Content-Type: Content-Transfer-Encoding:List-Subscribe:List-Help:List-Post:List-Archive: List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:Date:Message-ID:From: References:Cc:To:Subject:Reply-To:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=11zb85Jx7nSBixRaaHXULMM+ZuDhm8+MHaWgEXCsImQ=; b=0JHFdIn5giwg589xT0yaHuxv3w LMqE/PrrWgOLkfy0+xZxKs7o/eBvtIPBoexD1EL93Lv2+BQJ54EcxVAfXMesm/w2Iw6HEfvXzox0M PeM9VflF6cyH6SldvLGKwxTASf2e6u6dE89vjLDEKYX3y1z1kERmVUTyFI4d2v6/6PJEde8n4x0ro UmCxT8snzD3HL9OHHlD827O77dG0eeNEHjm2RHCOeUrnK7M4Kadms9p2Ga0ESN986wHZYwcSfYw/T DT8nTyBpU/X/FhdPtXVxdT7F42drIGN6wTLzvU6F6Zdby3e6O9T2Gihi3shMjBL4r6TWvvy7+zZOB CM5bBo5Q==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1mD85F-001RhM-7T; Mon, 09 Aug 2021 16:25:01 +0000 Received: from foss.arm.com ([217.140.110.172]) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1mD85A-001RgE-RZ; Mon, 09 Aug 2021 16:24:58 +0000 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id D5FD6D6E; Mon, 9 Aug 2021 09:24:51 -0700 (PDT) Received: from [192.168.122.166] (unknown [172.31.20.19]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 5C00E3F718; Mon, 9 Aug 2021 09:24:51 -0700 (PDT) Subject: Re: [PATCH 3/3] PCI/ACPI: Add new quirk detection, enable bcm2711 To: Rob Herring Cc: Bjorn Helgaas , PCI , Lorenzo Pieralisi , Nicolas Saenz Julienne , Bjorn Helgaas , "Rafael J. Wysocki" , Len Brown , Krzysztof Wilczynski , Florian Fainelli , "maintainer:BROADCOM BCM7XXX ARM ARCHITECTURE" , "open list:ACPI FOR ARM64 (ACPI/arm64)" , linux-arm-kernel , "moderated list:BROADCOM BCM2835 ARM ARCHITECTURE" , "linux-kernel@vger.kernel.org" References: <20210806221256.GA1891371@bjorn-Precision-5520> <5f4f484b-9eef-2722-405d-a7ff6259aa0f@arm.com> From: Jeremy Linton Message-ID: Date: Mon, 9 Aug 2021 11:24:46 -0500 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.10.1 MIME-Version: 1.0 In-Reply-To: Content-Language: en-US X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20210809_092457_063608_C9303001 X-CRM114-Status: GOOD ( 40.77 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset="us-ascii"; Format="flowed" Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org Hi, Thanks for looking at this. On 8/9/21 10:27 AM, Rob Herring wrote: > On Fri, Aug 6, 2021 at 6:35 PM Jeremy Linton wrote: >> >> Hi, >> >> Thanks for looking at this. >> >> On 8/6/21 5:12 PM, Bjorn Helgaas wrote: >>> In subject, this or similar would match history: >>> >>> PCI/ACPI: Add Broadcom bcm2711 MCFG quirk >>> >>> On Thu, Aug 05, 2021 at 04:12:00PM -0500, Jeremy Linton wrote: >>>> Now that we have a bcm2711 quirk, we need to be able to >>>> detect it when the MCFG is missing. Use a namespace >>>> property as an alternative to the MCFG OEM. >>> >>> Rewrap to use ~75 columns. >>> >>> Mention the DT namespace property here. >>> >>>> Signed-off-by: Jeremy Linton >>>> --- >>>> drivers/acpi/pci_mcfg.c | 14 ++++++++++++++ >>>> 1 file changed, 14 insertions(+) >>>> >>>> diff --git a/drivers/acpi/pci_mcfg.c b/drivers/acpi/pci_mcfg.c >>>> index 53cab975f612..7d77fc72c2a4 100644 >>>> --- a/drivers/acpi/pci_mcfg.c >>>> +++ b/drivers/acpi/pci_mcfg.c >>>> @@ -169,6 +169,9 @@ static struct mcfg_fixup mcfg_quirks[] = { >>>> ALTRA_ECAM_QUIRK(1, 13), >>>> ALTRA_ECAM_QUIRK(1, 14), >>>> ALTRA_ECAM_QUIRK(1, 15), >>>> + >>>> + { "bcm2711", "", 0, 0, MCFG_BUS_ANY, &bcm2711_pcie_ops, >>>> + DEFINE_RES_MEM(0xFD500000, 0xA000) }, >>>> }; >>>> >>>> static char mcfg_oem_id[ACPI_OEM_ID_SIZE]; >>>> @@ -198,8 +201,19 @@ static void pci_mcfg_apply_quirks(struct acpi_pci_root *root, >>>> u16 segment = root->segment; >>>> struct resource *bus_range = &root->secondary; >>>> struct mcfg_fixup *f; >>>> + const char *soc; >>>> int i; >>>> >>>> + /* >>>> + * This could be a machine with a PCI/SMC conduit, >>>> + * which means it doens't have MCFG. Get the machineid from >>>> + * the namespace definition instead. >>> >>> s/SMC/SMCCC/ ? Cover letter uses SMCCC (not sure it's relevant anyway) >>> s/doens't/doesn't/ >>> >>> Rewrap comment to use ~80 columns. >>> >>> Seems pretty reasonable that a platform without standard ECAM might >>> not have MCFG, since MCFG basically implies ECAM. >> >> >> Sure, on all the above comments. >> >>> >>> Is "linux,pcie-quirk" the right property to look for? It doesn't >>> sound very generic, and it doesn't sound like anything related to >>> ECAM. Is it new? I don't see it in the tree yet. Should it be in >>> Documentation/devicetree/bindings/pci/pci.txt so we don't get a >>> different property name for every new platform? > > No, it should not be in pci.txt. Nothing to do with DT and I don't > review ACPI bindings (someone should) if I can help it. That is the intention of the uefi properties registry I referred to earlier. It has a code first model too, which allows us to review it here and then update the document with the property and the intended behavior. > >> Yes, I made it up. Someone else commented about the "linux," partially >> because it should be "linux-" to conform with >> https://github.com/UEFI/DSD-Guide. But also in the same context of it >> being linux specific. I think that guide is where it should end up, >> rather than the devicetree bindings. >> >> I guess we can request addition to the uefi- but that seems like a >> mistake this is really (hopefully?) a Linux specific properly as other >> OS's will simply use the SMC. I think we could request another prefix if >> we come up with a good one and think it belongs in that guide. > > It's only Linux specific until it's not. > > What happens when there's a second PCIe quirk here? Say what the quirk > is (and not in terms of Linux policy). This is really just a stand in for the existing MCFG oem id, its an identifier to key off, nothing else. Maybe a better name is "linux-ecam-quirk-id" or something to that effect? > > Don't you know the device here and can imply all this (like implying > off of 'compatible' in DT)? Adding properties to address issues > creates compatibility issues. Maybe not an issue in this case if the > firmware is not stable, but not a good practice to be in. Yes, and no, I think there was some discussion a few years back about using non standard HID's for these nonstandard implementations, but that was discouraged at the time in favor of using the standard identifiers and and keying off a Soc/platform specific ID to enable a "quirk". Given we are a bit far down that path and the decision was made to continue down it (rather than solving much of it with a new firmware interface) this seems like the straightforward solution. The vast majority of these are SoC specific, and just minor tweaks for alignment/etc. Given its an ACPI/UEFI machine we are already hiding a lot of the platform specific behavior for configuring the bridge/etc that might require DT like properties in the firmware. Thanks again. _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel