From patchwork Fri Aug 27 08:31:28 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Huacai Chen X-Patchwork-Id: 12461571 X-Patchwork-Delegate: bhelgaas@google.com 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=-16.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT 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 05A98C432BE for ; Fri, 27 Aug 2021 08:37:36 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id D554D60F92 for ; Fri, 27 Aug 2021 08:37:35 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233297AbhH0IiX (ORCPT ); Fri, 27 Aug 2021 04:38:23 -0400 Received: from mail.kernel.org ([198.145.29.99]:45568 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232758AbhH0IiW (ORCPT ); Fri, 27 Aug 2021 04:38:22 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 1970260F4F; Fri, 27 Aug 2021 08:37:31 +0000 (UTC) From: Huacai Chen To: David Airlie , Daniel Vetter , Bjorn Helgaas Cc: linux-pci@vger.kernel.org, dri-devel@lists.freedesktop.org, Xuefeng Li , Huacai Chen , Huacai Chen Subject: [PATCH V4 09/10] PCI/VGA: Rework default VGA device selection (Step 1) Date: Fri, 27 Aug 2021 16:31:28 +0800 Message-Id: <20210827083129.2781420-10-chenhuacai@loongson.cn> X-Mailer: git-send-email 2.27.0 In-Reply-To: <20210827083129.2781420-1-chenhuacai@loongson.cn> References: <20210827083129.2781420-1-chenhuacai@loongson.cn> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org Current default VGA device selection fails in some cases: - On BMC system, the AST2500 bridge [1a03:1150] does not implement PCI_BRIDGE_CTL_VGA [1]. This is perfectly legal but means the legacy VGA resources won't reach downstream devices unless they're included in the usual bridge windows. - vga_arb_select_default_device() will set a device below such a bridge as the default VGA device as long as it has PCI_COMMAND_IO and PCI_COMMAND_MEMORY enabled. - vga_arbiter_add_pci_device() is called for every VGA device, either at boot-time or at hot-add time, and it will also set the device as the default VGA device, but ONLY if all bridges leading to it implement PCI_BRIDGE_CTL_VGA. - This difference between vga_arb_select_default_device() and vga_arbiter_add_pci_device() means that a device below an AST2500 or similar bridge can only be set as the default if it is enumerated before vga_arb_device_init(). - On ACPI-based systems, PCI devices are enumerated by acpi_init(), which runs before vga_arb_device_init(). - On non-ACPI systems, like on MIPS system, they are enumerated by pcibios_init(), which typically runs *after* vga_arb_device_init(). So I made vga_arb_update_default_device() to replace the current vga_ arb_select_default_device(), which will be call from vga_arbiter_add_ pci_device(), set the default device even if it does not own the VGA resources because an upstream bridge doesn't implement PCI_BRIDGE_CTL_ VGA. And the default VGA device is updated if a better one is found (device with legacy resources enabled is better, device owns the firmware framebuffer is even better). This patch is the first step: complete vga_arb_update_default_device(). The logic of selecting the best device is the same as vga_arb_select_ default_device(). Signed-off-by: Huacai Chen Signed-off-by: Bjorn Helgaas --- drivers/pci/vgaarb.c | 69 ++++++++++++++++++++++++++++++++++++++++++-- 1 file changed, 66 insertions(+), 3 deletions(-) diff --git a/drivers/pci/vgaarb.c b/drivers/pci/vgaarb.c index dd07b1c3205f..ee7caee08b1b 100644 --- a/drivers/pci/vgaarb.c +++ b/drivers/pci/vgaarb.c @@ -580,16 +580,79 @@ static bool vga_arb_integrated_gpu(struct device *dev) static void vga_arb_update_default_device(struct vga_device *vgadev) { struct pci_dev *pdev = vgadev->pdev; + struct device *dev = &pdev->dev; + struct vga_device *vgadev_default; +#if defined(CONFIG_X86) || defined(CONFIG_IA64) + int i; + unsigned long flags; + u64 base = screen_info.lfb_base; + u64 size = screen_info.lfb_size; + u64 limit; + resource_size_t start, end; +#endif /* * If we don't have a default VGA device yet, and this device owns * the legacy VGA resources, make it the default. */ - if (!vga_default_device() && - ((vgadev->owns & VGA_RSRC_LEGACY_MASK) == VGA_RSRC_LEGACY_MASK)) { - vgaarb_info(&pdev->dev, "setting as boot VGA device\n"); + if (!vga_default_device()) { + if ((vgadev->owns & VGA_RSRC_LEGACY_MASK) == VGA_RSRC_LEGACY_MASK) + vgaarb_info(dev, "setting as boot VGA device\n"); + else + vgaarb_info(dev, "setting as boot device (VGA legacy resources not available)\n"); + vga_set_default_device(pdev); + } + + vgadev_default = vgadev_find(vga_default); + + /* Overridden by a better device */ + if (vgadev_default && ((vgadev_default->owns & VGA_RSRC_LEGACY_MASK) == 0) + && ((vgadev->owns & VGA_RSRC_LEGACY_MASK) == VGA_RSRC_LEGACY_MASK)) { + vgaarb_info(dev, "overriding boot VGA device\n"); vga_set_default_device(pdev); } + + if (vga_arb_integrated_gpu(dev)) { + vgaarb_info(dev, "overriding boot VGA device\n"); + vga_set_default_device(pdev); + } + +#if defined(CONFIG_X86) || defined(CONFIG_IA64) + if (screen_info.capabilities & VIDEO_CAPABILITY_64BIT_BASE) + base |= (u64)screen_info.ext_lfb_base << 32; + + limit = base + size; + + /* + * Override vga_arbiter_add_pci_device()'s I/O based detection + * as it may take the wrong device (e.g. on Apple system under + * EFI). + * + * Select the device owning the boot framebuffer if there is + * one. + */ + + /* Does firmware framebuffer belong to us? */ + for (i = 0; i < DEVICE_COUNT_RESOURCE; i++) { + flags = pci_resource_flags(vgadev->pdev, i); + + if ((flags & IORESOURCE_MEM) == 0) + continue; + + start = pci_resource_start(vgadev->pdev, i); + end = pci_resource_end(vgadev->pdev, i); + + if (!start || !end) + continue; + + if (base < start || limit >= end) + continue; + + if (vgadev->pdev != vga_default_device()) + vgaarb_info(dev, "overriding boot device\n"); + vga_set_default_device(vgadev->pdev); + } +#endif } /*