From patchwork Fri Jun 30 10:17:29 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Sui Jingfeng X-Patchwork-Id: 13297940 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 gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id A5E49EB64D7 for ; Fri, 30 Jun 2023 10:18:00 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id C064F10E152; Fri, 30 Jun 2023 10:17:59 +0000 (UTC) Received: from out-60.mta0.migadu.com (out-60.mta0.migadu.com [91.218.175.60]) by gabe.freedesktop.org (Postfix) with ESMTPS id 1D6E410E144 for ; Fri, 30 Jun 2023 10:17:47 +0000 (UTC) X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1688120266; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=3Ml7rkVkU9dTc0+Xfj7L5gDY8LPJxmXh8rcpwPh2b98=; b=BGaslFGf5MzqKg8hmjZQCbuFcW8ysx9xCnhDgdWOUZJyDhIpqCppGx4MdN0PN3JEm09nqk IXICgDA0TFnSpwMSzsvHUKky+eQnGOyURH6hEuDAWTxLZSMO+84otNiFMoM30NBFdK97j1 iEulAEIbzcJr8RYBCQAmeihTHD6DaWo= From: Sui Jingfeng To: Bjorn Helgaas , Maarten Lankhorst , Maxime Ripard , Thomas Zimmermann , David Airlie , Daniel Vetter Subject: [PATCH 2/4] PCI/VGA: Deal only with PCI VGA class devices Date: Fri, 30 Jun 2023 18:17:29 +0800 Message-Id: <20230630101731.134375-2-sui.jingfeng@linux.dev> In-Reply-To: <20230630101731.134375-1-sui.jingfeng@linux.dev> References: <20230630101731.134375-1-sui.jingfeng@linux.dev> MIME-Version: 1.0 X-Migadu-Flow: FLOW_OUT X-BeenThere: dri-devel@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Direct Rendering Infrastructure - Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: linux-pci@vger.kernel.org, Sui Jingfeng , linux-kernel@vger.kernel.org, dri-devel@lists.freedesktop.org, Mario Limonciello Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" From: Sui Jingfeng VGAARB should only care about PCI VGA class devices (pdev->class == 0x0300) since only those devices might have VGA routed to them.      PCI_CLASS_DISPLAY_3D and PCI_CLASS_DISPLAY_OTHER are used to annotate the render-only GPU. Render-only GPUs shouldn't decode the fixed VGA address. For example, nvidia render-only GPU typically has 0x0380 as its PCI class. A render-only GPU cannot be used to display something on the screen. Hence, it should not be the default boot device in normal cases. Cc: Bjorn Helgaas Reviewed-by: Mario Limonciello Signed-off-by: Sui Jingfeng --- drivers/pci/vgaarb.c | 22 ++++++++++++---------- 1 file changed, 12 insertions(+), 10 deletions(-) diff --git a/drivers/pci/vgaarb.c b/drivers/pci/vgaarb.c index c1bc6c983932..22a505e877dc 100644 --- a/drivers/pci/vgaarb.c +++ b/drivers/pci/vgaarb.c @@ -754,10 +754,6 @@ static bool vga_arbiter_add_pci_device(struct pci_dev *pdev) struct pci_dev *bridge; u16 cmd; - /* Only deal with VGA class devices */ - if ((pdev->class >> 8) != PCI_CLASS_DISPLAY_VGA) - return false; - /* Allocate structure */ vgadev = kzalloc(sizeof(struct vga_device), GFP_KERNEL); if (vgadev == NULL) { @@ -1500,7 +1496,9 @@ static int pci_notify(struct notifier_block *nb, unsigned long action, struct pci_dev *pdev = to_pci_dev(dev); bool notify = false; - vgaarb_dbg(dev, "%s\n", __func__); + /* Only deal with VGA class devices */ + if (pdev->class != PCI_CLASS_DISPLAY_VGA << 8) + return 0; /* For now we're only intereted in devices added and removed. I didn't * test this thing here, so someone needs to double check for the @@ -1510,6 +1508,8 @@ static int pci_notify(struct notifier_block *nb, unsigned long action, else if (action == BUS_NOTIFY_DEL_DEVICE) notify = vga_arbiter_del_pci_device(pdev); + vgaarb_dbg(dev, "%s: action = %lu\n", __func__, action); + if (notify) vga_arbiter_notify_clients(); return 0; @@ -1534,8 +1534,8 @@ static struct miscdevice vga_arb_device = { static int __init vga_arb_device_init(void) { + struct pci_dev *pdev = NULL; int rc; - struct pci_dev *pdev; rc = misc_register(&vga_arb_device); if (rc < 0) @@ -1545,11 +1545,13 @@ static int __init vga_arb_device_init(void) /* We add all PCI devices satisfying VGA class in the arbiter by * default */ - pdev = NULL; - while ((pdev = - pci_get_subsys(PCI_ANY_ID, PCI_ANY_ID, PCI_ANY_ID, - PCI_ANY_ID, pdev)) != NULL) + while (1) { + pdev = pci_get_class(PCI_CLASS_DISPLAY_VGA << 8, pdev); + if (!pdev) + break; + vga_arbiter_add_pci_device(pdev); + } pr_info("loaded\n"); return rc;