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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 9C82BEB64D9 for ; Fri, 7 Jul 2023 15:12:28 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232693AbjGGPM0 (ORCPT ); Fri, 7 Jul 2023 11:12:26 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:51068 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229757AbjGGPMT (ORCPT ); Fri, 7 Jul 2023 11:12:19 -0400 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 8199A212C for ; Fri, 7 Jul 2023 08:11:29 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1688742688; 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; bh=/vpgghRxsUnXsE3t1IVpXcHF3Kir76KUPEpQodsytdc=; b=c+nLXn4OZLR9JopyYhq/kLKcu5hVDcMJgVZSqqvUmMU9sSkNL6kfZhp26EcF8NDrZIe0wi l0MWnOpFXfPNaOUuB2C1NUvJ3AZ1VW6xwfD6/Ztxvn7VL05I1e2pmxNXbXFZ9qB83+YAgF sD5KsFJ5eqPjy9XcVtxU7Ied6RcbTIU= Received: from mimecast-mx02.redhat.com (mx3-rdu2.redhat.com [66.187.233.73]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-425-huiRPxb7MyqWJbXufgI7Jw-1; Fri, 07 Jul 2023 11:11:27 -0400 X-MC-Unique: huiRPxb7MyqWJbXufgI7Jw-1 Received: from smtp.corp.redhat.com (int-mx08.intmail.prod.int.rdu2.redhat.com [10.11.54.8]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id D28691C060C9; Fri, 7 Jul 2023 15:11:26 +0000 (UTC) Received: from omen.home.shazbot.org (unknown [10.22.17.80]) by smtp.corp.redhat.com (Postfix) with ESMTP id 70FCAC09A09; Fri, 7 Jul 2023 15:11:26 +0000 (UTC) From: Alex Williamson To: bhelgaas@google.com Cc: Alex Williamson , linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org, eric.auger@redhat.com Subject: [PATCH] PCI/VPD: Add runtime power management to sysfs interface Date: Fri, 7 Jul 2023 09:10:44 -0600 Message-Id: <20230707151044.1311544-1-alex.williamson@redhat.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Scanned-By: MIMEDefang 3.1 on 10.11.54.8 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Unlike default access to config space through sysfs, the vpd read and write function don't actively manage the runtime power management state of the device during access. Since commit 7ab5e10eda02 ("vfio/pci: Move the unused device into low power state with runtime PM"), the vfio-pci driver will use runtime power management and release unused devices to make use of low power states. Attempting to access VPD information in this low power state can result in incorrect information or kernel crashes depending on the system behavior. Wrap the vpd read/write bin attribute handlers in runtime PM and take into account the potential quirk to select the correct device to wake. Signed-off-by: Alex Williamson --- drivers/pci/vpd.c | 34 ++++++++++++++++++++++++++++++++-- 1 file changed, 32 insertions(+), 2 deletions(-) diff --git a/drivers/pci/vpd.c b/drivers/pci/vpd.c index a4fc4d0690fe..81217dd4789f 100644 --- a/drivers/pci/vpd.c +++ b/drivers/pci/vpd.c @@ -275,8 +275,23 @@ static ssize_t vpd_read(struct file *filp, struct kobject *kobj, size_t count) { struct pci_dev *dev = to_pci_dev(kobj_to_dev(kobj)); + struct pci_dev *vpd_dev = dev; + ssize_t ret; + + if (dev->dev_flags & PCI_DEV_FLAGS_VPD_REF_F0) { + vpd_dev = pci_get_func0_dev(dev); + if (!vpd_dev) + return -ENODEV; + } + + pci_config_pm_runtime_get(vpd_dev); + ret = pci_read_vpd(vpd_dev, off, count, buf); + pci_config_pm_runtime_put(vpd_dev); + + if (dev != vpd_dev) + pci_dev_put(vpd_dev); - return pci_read_vpd(dev, off, count, buf); + return ret; } static ssize_t vpd_write(struct file *filp, struct kobject *kobj, @@ -284,8 +299,23 @@ static ssize_t vpd_write(struct file *filp, struct kobject *kobj, size_t count) { struct pci_dev *dev = to_pci_dev(kobj_to_dev(kobj)); + struct pci_dev *vpd_dev = dev; + ssize_t ret; + + if (dev->dev_flags & PCI_DEV_FLAGS_VPD_REF_F0) { + vpd_dev = pci_get_func0_dev(dev); + if (!vpd_dev) + return -ENODEV; + } + + pci_config_pm_runtime_get(vpd_dev); + ret = pci_write_vpd(vpd_dev, off, count, buf); + pci_config_pm_runtime_put(vpd_dev); + + if (dev != vpd_dev) + pci_dev_put(vpd_dev); - return pci_write_vpd(dev, off, count, buf); + return ret; } static BIN_ATTR(vpd, 0600, vpd_read, vpd_write, 0); -- 2.40.1