From patchwork Fri Feb 25 14:15:50 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Tejas Upadhyay X-Patchwork-Id: 12760372 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 1C107C433EF for ; Fri, 25 Feb 2022 14:29:25 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 9602A10E461; Fri, 25 Feb 2022 14:29:24 +0000 (UTC) Received: from mga05.intel.com (mga05.intel.com [192.55.52.43]) by gabe.freedesktop.org (Postfix) with ESMTPS id 6B39510E461 for ; Fri, 25 Feb 2022 14:29:23 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1645799363; x=1677335363; h=from:to:cc:subject:date:message-id:mime-version: content-transfer-encoding; bh=O6hER5E1XhrsunST4ZJLI4jCQ46zinexpzFLPxonyMY=; b=gjfmKR67Z7vUmQRr8EyqQm5pCPKqQErBJsiYA//RnKUj6omHp3ulVGSC x+oMCrVTtH0aebMSuB1BzANn9JtnPjOhuAyfZX66lNBOxfzMYzb8QjZdQ CNECQupR8ohnsaRbvU7R/pfVbZ+DRSuolrc+iSNunIuZTqNsvX9rm/sac 6ZdM9STj5jnkubNphBQBcj0iewHrjp4Tgx7gnMg5R5i1vX9FItmurecr1 MuRYhF9PuSSkCf7TSIOeANIRCxWalIgddjr2+jNSClQt+plX7H4A95A0k eja0K65Mxfalb9VfncNeehg66i1j/4KWMdt5h5dYt92wwcb9YHSfNiBnM g==; X-IronPort-AV: E=McAfee;i="6200,9189,10268"; a="338940157" X-IronPort-AV: E=Sophos;i="5.90,136,1643702400"; d="scan'208";a="338940157" Received: from fmsmga001.fm.intel.com ([10.253.24.23]) by fmsmga105.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 25 Feb 2022 06:29:22 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.90,136,1643702400"; d="scan'208";a="684664900" Received: from tejas-system-product-name.iind.intel.com ([10.145.162.130]) by fmsmga001.fm.intel.com with ESMTP; 25 Feb 2022 06:29:20 -0800 From: Tejas Upadhyay To: intel-gfx@lists.freedesktop.org Date: Fri, 25 Feb 2022 19:45:50 +0530 Message-Id: <20220225141550.162490-1-tejaskumarx.surendrakumar.upadhyay@intel.com> X-Mailer: git-send-email 2.34.1 MIME-Version: 1.0 Subject: [Intel-gfx] [PATCH topic/core-for-CI] PCI: vmd: Prevent recursive locking on interrupt allocation X-BeenThere: intel-gfx@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Intel graphics driver community testing & development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: linux-pci@vger.kernel.org, Thomas Gleixner , "Surendrakumar Upadhyay, TejaskumarX" Errors-To: intel-gfx-bounces@lists.freedesktop.org Sender: "Intel-gfx" From: Thomas Gleixner Tejas reported the following recursive locking issue: swapper/0/1 is trying to acquire lock: ffff8881074fd0a0 (&md->mutex){+.+.}-{3:3}, at: msi_get_virq+0x30/0xc0 but task is already holding lock: ffff8881017cd6a0 (&md->mutex){+.+.}-{3:3}, at: __pci_enable_msi_range+0xf2/0x290 stack backtrace: __mutex_lock+0x9d/0x920 msi_get_virq+0x30/0xc0 pci_irq_vector+0x26/0x30 vmd_msi_init+0xcc/0x210 msi_domain_alloc+0xbf/0x150 msi_domain_alloc_irqs_descs_locked+0x3e/0xb0 __pci_enable_msi_range+0x155/0x290 pci_alloc_irq_vectors_affinity+0xba/0x100 pcie_port_device_register+0x307/0x550 pcie_portdrv_probe+0x3c/0xd0 pci_device_probe+0x95/0x110 This is caused by the VMD MSI code which does a lookup of the Linux interrupt number for an VMD managed MSI[X] vector. The lookup function tries to acquire the already held mutex. Avoid that by caching the Linux interrupt number at initialization time instead of looking it up over and over. Fixes: 82ff8e6b78fc ("PCI/MSI: Use msi_get_virq() in pci_get_vector()") Reported-by: "Surendrakumar Upadhyay, TejaskumarX" Signed-off-by: Thomas Gleixner Tested-by: "Surendrakumar Upadhyay, TejaskumarX" Cc: linux-pci@vger.kernel.org Link: https://lore.kernel.org/r/87a6euub2a.ffs@tglx --- drivers/pci/controller/vmd.c | 14 +++++++------- 1 file changed, 7 insertions(+), 7 deletions(-) diff --git a/drivers/pci/controller/vmd.c b/drivers/pci/controller/vmd.c index cc166c683638..eb05cceab964 100644 --- a/drivers/pci/controller/vmd.c +++ b/drivers/pci/controller/vmd.c @@ -99,11 +99,13 @@ struct vmd_irq { * @srcu: SRCU struct for local synchronization. * @count: number of child IRQs assigned to this vector; used to track * sharing. + * @virq: The underlying VMD Linux interrupt number */ struct vmd_irq_list { struct list_head irq_list; struct srcu_struct srcu; unsigned int count; + unsigned int virq; }; struct vmd_dev { @@ -253,7 +255,6 @@ static int vmd_msi_init(struct irq_domain *domain, struct msi_domain_info *info, struct msi_desc *desc = arg->desc; struct vmd_dev *vmd = vmd_from_bus(msi_desc_to_pci_dev(desc)->bus); struct vmd_irq *vmdirq = kzalloc(sizeof(*vmdirq), GFP_KERNEL); - unsigned int index, vector; if (!vmdirq) return -ENOMEM; @@ -261,10 +262,8 @@ static int vmd_msi_init(struct irq_domain *domain, struct msi_domain_info *info, INIT_LIST_HEAD(&vmdirq->node); vmdirq->irq = vmd_next_irq(vmd, desc); vmdirq->virq = virq; - index = index_from_irqs(vmd, vmdirq->irq); - vector = pci_irq_vector(vmd->dev, index); - irq_domain_set_info(domain, virq, vector, info->chip, vmdirq, + irq_domain_set_info(domain, virq, vmdirq->irq->virq, info->chip, vmdirq, handle_untracked_irq, vmd, NULL); return 0; } @@ -685,7 +684,8 @@ static int vmd_alloc_irqs(struct vmd_dev *vmd) return err; INIT_LIST_HEAD(&vmd->irqs[i].irq_list); - err = devm_request_irq(&dev->dev, pci_irq_vector(dev, i), + vmd->irqs[i].virq = pci_irq_vector(dev, i); + err = devm_request_irq(&dev->dev, vmd->irqs[i].virq, vmd_irq, IRQF_NO_THREAD, vmd->name, &vmd->irqs[i]); if (err) @@ -969,7 +969,7 @@ static int vmd_suspend(struct device *dev) int i; for (i = 0; i < vmd->msix_count; i++) - devm_free_irq(dev, pci_irq_vector(pdev, i), &vmd->irqs[i]); + devm_free_irq(dev, vmd->irqs[i].virq, &vmd->irqs[i]); return 0; } @@ -981,7 +981,7 @@ static int vmd_resume(struct device *dev) int err, i; for (i = 0; i < vmd->msix_count; i++) { - err = devm_request_irq(dev, pci_irq_vector(pdev, i), + err = devm_request_irq(dev, vmd->irqs[i].virq, vmd_irq, IRQF_NO_THREAD, vmd->name, &vmd->irqs[i]); if (err)