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 mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 22274C4332F for ; Tue, 5 Oct 2021 15:10:47 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 09662614C8 for ; Tue, 5 Oct 2021 15:10:47 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235528AbhJEPMg (ORCPT ); Tue, 5 Oct 2021 11:12:36 -0400 Received: from mail.kernel.org ([198.145.29.99]:35574 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229488AbhJEPMe (ORCPT ); Tue, 5 Oct 2021 11:12:34 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id A7604613AC; Tue, 5 Oct 2021 15:10:43 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1633446644; bh=Oj/dpsXfZsdFT7IwiB6sdPRCjBt10BrnkG8D+uo6sIo=; h=Date:From:To:Cc:Subject:In-Reply-To:From; b=AufutoAB69XX17b/4aQLtRhiBG9Avh+kvxdspsskno6fEhAuWl4qN+adoAG9BKH2P PyXghsGrmDUcR7jDXCAFw++X8BZsXNYN7zOR53H1AmRYXgM6JpRZGBx7nA5cFD+fGY 4/3jwswfV3hInmbo80Ko1w6scY0FmY23rBNsnUHrP34WCluoZYylOrXW8+BF3e2pau ms6H1zZZrVQhH6kpk5U2zKhSbUrwIHZqUAEm3Jh5kcQCa1RNbyruYlvMkxT0hiQ7PI ZcFUN0Vcl2HsjPrKsrN2er50Qnr/0+QMiPO3ME2XqfLxeergohRnJJ+gT53QLfYgEj lV4jvS5wK36sg== Date: Tue, 5 Oct 2021 10:10:42 -0500 From: Bjorn Helgaas To: Jeremy Linton Cc: linux-pci@vger.kernel.org, lorenzo.pieralisi@arm.com, nsaenz@kernel.org, bhelgaas@google.com, rjw@rjwysocki.net, lenb@kernel.org, robh@kernel.org, kw@linux.com, f.fainelli@gmail.com, bcm-kernel-feedback-list@broadcom.com, linux-acpi@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-rpi-kernel@lists.infradead.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v3 3/4] PCI/ACPI: Add Broadcom bcm2711 MCFG quirk Message-ID: <20211005151042.GA1083482@bhelgaas> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20210826071557.29239-4-jeremy.linton@arm.com> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Aug 26, 2021 at 02:15:56AM -0500, Jeremy Linton wrote: > Now that there is a bcm2711 quirk, it needs to be enabled when the > MCFG is missing. Use an ACPI namespace _DSD property > "linux-ecam-quirk-id" as an alternative to the MCFG OEM. > > Signed-off-by: Jeremy Linton > Acked-by: Florian Fainelli > Acked-by: Bjorn Helgaas > --- > drivers/acpi/pci_mcfg.c | 17 +++++++++++++++++ > 1 file changed, 17 insertions(+) > > diff --git a/drivers/acpi/pci_mcfg.c b/drivers/acpi/pci_mcfg.c > index 53cab975f612..04c517418365 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), > + > + { "bc2711", "", 0, 0, MCFG_BUS_ANY, &bcm2711_pcie_ops, > + DEFINE_RES_MEM(0xFD500000, 0xA000) }, > }; > > static char mcfg_oem_id[ACPI_OEM_ID_SIZE]; > @@ -198,8 +201,22 @@ 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 may be a machine with a PCI/SMC conduit, which means it doesn't > + * have an MCFG. Use an ACPI namespace definition instead. > + */ > + if (!fwnode_property_read_string(acpi_fwnode_handle(root->device), > + "linux-ecam-quirk-id", &soc)) { > + if (strlen(soc) != ACPI_OEM_ID_SIZE) >From a reviewing perspective, it's not obvious why soc must be exactly ACPI_OEM_ID_SIZE. Does that imply space-padding in the DT string or something? Is there any documentation for this DT property? Also not obvious why strlen() is safe here. I mean, I looked a couple levels deep in fwnode_property_read_string(), but whatever guarantees null termination is buried pretty deep. It seems a little weird to use an MCFG quirk mechanism when there's no MCFG at all on this platform. > + dev_err(&root->device->dev, "ECAM quirk should be %d characters\n", > + ACPI_OEM_ID_SIZE); > + else > + memcpy(mcfg_oem_id, soc, ACPI_OEM_ID_SIZE); > + } > + > for (i = 0, f = mcfg_quirks; i < ARRAY_SIZE(mcfg_quirks); i++, f++) { > if (pci_mcfg_quirk_matches(f, segment, bus_range)) { > if (f->cfgres.start) > -- > 2.31.1 >