From patchwork Tue Jul 11 13:43:50 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Sui Jingfeng X-Patchwork-Id: 13308757 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 388DBC001DD for ; Tue, 11 Jul 2023 13:44:26 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 016D910E39D; Tue, 11 Jul 2023 13:44:23 +0000 (UTC) Received: from out-20.mta0.migadu.com (out-20.mta0.migadu.com [IPv6:2001:41d0:1004:224b::14]) by gabe.freedesktop.org (Postfix) with ESMTPS id 231E510E397 for ; Tue, 11 Jul 2023 13:44:19 +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=1689083056; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=EDDNh+sBHMY69JnXGN2eCCl56IIKvpnc8EX4QusViis=; b=WUckSHg09hEzPNeV04y0qZK1g3Jy9t7p1rUsytc1VIEpkXvlHG61+vjN0q3AnCCGgpqhSs Ev+jicQte07i3NBYujTu9tcXWwIGZPveSSOVVHCEoNbZomNXUMlxpmz14wyegvfITmsQed 7l+nv0PlzbWeGIJCvkQ9zw0SS77e7K0= From: Sui Jingfeng To: Bjorn Helgaas , Maarten Lankhorst , Maxime Ripard , Thomas Zimmermann , David Airlie , Daniel Vetter , Sui@freedesktop.org, Jingfeng@loongson.cn Subject: [PATCH 2/6] PCI/VGA: Deal with PCI VGA compatible devices only Date: Tue, 11 Jul 2023 21:43:50 +0800 Message-Id: <20230711134354.755966-3-sui.jingfeng@linux.dev> In-Reply-To: <20230711134354.755966-1-sui.jingfeng@linux.dev> References: <20230711134354.755966-1-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: Sui Jingfeng , linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org, dri-devel@lists.freedesktop.org, loongson-kernel@lists.loongnix.cn, Mario Limonciello Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" From: Sui Jingfeng Currently, vgaarb only cares about PCI VGA-compatible class devices. While vga_arbiter_del_pci_device() gets called unbalanced when some PCI device is about to be removed. This happens even during the boot process. Another reason is that the vga_arb_device_init() function is not efficient. Since we only care about VGA-compatible devices (pdev->class == 0x030000), We could filter the unqualified devices out in the vga_arb_device_init() function. While the current implementation is to search all PCI devices in a system, this is not necessary. Reviewed-by: Mario Limonciello Signed-off-by: Sui Jingfeng --- drivers/pci/vgaarb.c | 25 +++++++++++++------------ 1 file changed, 13 insertions(+), 12 deletions(-) diff --git a/drivers/pci/vgaarb.c b/drivers/pci/vgaarb.c index c1bc6c983932..021116ed61cb 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) { @@ -1502,6 +1498,10 @@ static int pci_notify(struct notifier_block *nb, unsigned long action, vgaarb_dbg(dev, "%s\n", __func__); + /* Deal with VGA compatible devices only */ + if ((pdev->class >> 8) != PCI_CLASS_DISPLAY_VGA) + 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 * cases of hotplugable vga cards. */ @@ -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) @@ -1543,13 +1543,14 @@ static int __init vga_arb_device_init(void) bus_register_notifier(&pci_bus_type, &pci_notifier); - /* 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) - vga_arbiter_add_pci_device(pdev); + /* + * We add all PCI VGA compatible devices in the arbiter by default + */ + do { + pdev = pci_get_class(PCI_CLASS_DISPLAY_VGA << 8, pdev); + if (pdev) + vga_arbiter_add_pci_device(pdev); + } while (pdev); pr_info("loaded\n"); return rc;