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=-10.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT 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 E10F8C43215 for ; Tue, 26 Nov 2019 16:30:00 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id BB02020722 for ; Tue, 26 Nov 2019 16:30:00 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1574785800; bh=qrvXuMHKCoQOdORxNJ+YbqsB49FLPqu3p1fW/+eSpZo=; h=From:To:Cc:Subject:Date:List-ID:From; b=0q/OgHLd9EZa8OTV3Fx0MduWx9Ytw3Av5yd+98Z8ok0YdniF+MveJfyAc3ULaOcae /6QNWyPlcBgM3Ur4gh97eOOa3hN31iAqpeFDq4uWIV+vYlxCiqDd9JsCgvw8f+kHH3 uwJfryN3G22h83TdqySTngVRB90k/tqB/EiBbXUQ= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727859AbfKZQaA (ORCPT ); Tue, 26 Nov 2019 11:30:00 -0500 Received: from mail.kernel.org ([198.145.29.99]:44620 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725972AbfKZQ37 (ORCPT ); Tue, 26 Nov 2019 11:29:59 -0500 Received: from localhost.localdomain (91-167-84-221.subs.proxad.net [91.167.84.221]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 184572071A; Tue, 26 Nov 2019 16:29:56 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1574785798; bh=qrvXuMHKCoQOdORxNJ+YbqsB49FLPqu3p1fW/+eSpZo=; h=From:To:Cc:Subject:Date:From; b=rNwTJiwpENG4ilu/hr3qpPAyWcnzAGOtNgVJBrxsMrEgkzWe0Ng+15ivaad2xTIvx yMTwWWetijnvVdKWKUlrh5QdY8wiellk32/tA6dpP1AjdcTEAoL2qjvN//Fb8u6qal YuLRlvReTloPuw1Grmkb393LOg6lU11gvYBcBctQ= From: Ard Biesheuvel To: linux-kernel@vger.kernel.org Cc: linux-arm-kernel@lists.infradead.org, linux-efi@vger.kernel.org, will@kernel.org, bhelgaas@google.com, Ard Biesheuvel , Greg Kroah-Hartman , Saravana Kannan Subject: [PATCH] efi: arm: defer probe of PCIe backed efifb on DT systems Date: Tue, 26 Nov 2019 17:29:02 +0100 Message-Id: <20191126162902.16788-1-ardb@kernel.org> X-Mailer: git-send-email 2.20.1 MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org The new of_devlink support breaks PCIe probing on ARM platforms booting via UEFI if the firmware exposes a EFI framebuffer that is backed by a PCI device. The reason is that the probing order gets reversed, resulting in a resource conflict on the framebuffer memory window when the PCIe probes last, causing it to give up entirely. Given that we rely on PCI quirks to deal with EFI framebuffers that get moved around in memory, we cannot simply drop the memory reservation, so instead, let's use the device link infrastructure to register this dependency, and force the probing to occur in the expected order. Cc: Greg Kroah-Hartman Cc: Saravana Kannan Signed-off-by: Ard Biesheuvel --- drivers/firmware/efi/arm-init.c | 66 ++++++++++++++++++-- 1 file changed, 61 insertions(+), 5 deletions(-) diff --git a/drivers/firmware/efi/arm-init.c b/drivers/firmware/efi/arm-init.c index 311cd349a862..617226d50774 100644 --- a/drivers/firmware/efi/arm-init.c +++ b/drivers/firmware/efi/arm-init.c @@ -14,6 +14,7 @@ #include #include #include +#include #include #include #include @@ -267,15 +268,70 @@ void __init efi_init(void) efi_memmap_unmap(); } +static bool __init efifb_overlaps_pci_range(const struct of_pci_range *range) +{ + u64 fb_base = screen_info.lfb_base; + + if (screen_info.capabilities & VIDEO_CAPABILITY_64BIT_BASE) + fb_base |= (u64)(unsigned long)screen_info.ext_lfb_base << 32; + + return fb_base >= range->cpu_addr && + fb_base < (range->cpu_addr + range->size); +} + static int __init register_gop_device(void) { - void *pd; + struct platform_device *pd; + struct device_node *np; + bool found = false; + int err; if (screen_info.orig_video_isVGA != VIDEO_TYPE_EFI) return 0; - pd = platform_device_register_data(NULL, "efi-framebuffer", 0, - &screen_info, sizeof(screen_info)); - return PTR_ERR_OR_ZERO(pd); + pd = platform_device_alloc("efi-framebuffer", 0); + if (!pd) + return -ENOMEM; + + err = platform_device_add_data(pd, &screen_info, sizeof(screen_info)); + if (err) + return err; + + /* + * If the efifb framebuffer is backed by a PCI graphics controller, we + * have to ensure that this relation is expressed using a device link + * when running in DT mode, or the probe order may be reversed, + * resulting in a resource reservation conflict on the memory window + * that the efifb framebuffer steals from the PCIe host bridge. + */ + for_each_node_by_type(np, "pci") { + struct of_pci_range_parser parser; + struct of_pci_range range; + struct device *sup_dev; + + if (found) { + of_node_put(np); + break; + } + + err = of_pci_range_parser_init(&parser, np); + if (err) { + pr_warn("of_pci_range_parser_init() failed: %d\n", err); + continue; + } + + sup_dev = get_dev_from_fwnode(&np->fwnode); + + for_each_of_pci_range(&parser, &range) { + if (efifb_overlaps_pci_range(&range)) { + found = true; + if (!device_link_add(&pd->dev, sup_dev, 0)) + pr_warn("device_link_add() failed\n"); + break; + } + } + put_device(sup_dev); + } + return platform_device_add(pd); } -subsys_initcall(register_gop_device); +device_initcall(register_gop_device); -- 2.20.1