From patchwork Mon Nov 5 20:20:36 2012 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Donald Dutile X-Patchwork-Id: 1700291 X-Patchwork-Delegate: bhelgaas@google.com Return-Path: X-Original-To: patchwork-linux-pci@patchwork.kernel.org Delivered-To: patchwork-process-083081@patchwork2.kernel.org Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by patchwork2.kernel.org (Postfix) with ESMTP id 3ED31DF2AB for ; Mon, 5 Nov 2012 20:20:58 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753893Ab2KEUU5 (ORCPT ); Mon, 5 Nov 2012 15:20:57 -0500 Received: from mx1.redhat.com ([209.132.183.28]:12075 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753889Ab2KEUU4 (ORCPT ); Mon, 5 Nov 2012 15:20:56 -0500 Received: from int-mx10.intmail.prod.int.phx2.redhat.com (int-mx10.intmail.prod.int.phx2.redhat.com [10.5.11.23]) by mx1.redhat.com (8.14.4/8.14.4) with ESMTP id qA5KKofr017068 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=OK); Mon, 5 Nov 2012 15:20:50 -0500 Received: from dddsys0.bos.redhat.com (dddsys0.bos.redhat.com [10.16.184.11]) by int-mx10.intmail.prod.int.phx2.redhat.com (8.14.4/8.14.4) with ESMTP id qA5KKjMS019862; Mon, 5 Nov 2012 15:20:49 -0500 From: Donald Dutile To: linux-pci@vger.kernel.org Cc: bhelgaas@google.com, yuvalmin@broadcom.com, bhutchings@solarflare.com, gregory.v.rose@intel.com, yinghai@kernel.org, davem@davemloft.net, ddutile@redhat.com Subject: [PATCH 3/4] PCI,sys: SRIOV control and status via sysfs Date: Mon, 5 Nov 2012 15:20:36 -0500 Message-Id: <1352146841-64458-4-git-send-email-ddutile@redhat.com> In-Reply-To: <1352146841-64458-1-git-send-email-ddutile@redhat.com> References: <1352146841-64458-1-git-send-email-ddutile@redhat.com> X-Scanned-By: MIMEDefang 2.68 on 10.5.11.23 Sender: linux-pci-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org Provide files under sysfs to determine the max number of vfs an SRIOV-capable PCIe device supports, and methods to enable and disable the vfs on a per device basis. Currently, VF enablement by SRIOV-capable PCIe devices is done in driver-specific module parameters. If not setup in modprobe files, it requires admin to unload & reload PF drivers with number of desired VFs to enable. Additionally, the enablement is system wide: all devices controlled by the same driver have the same number of VFs enabled. Although the latter is probably desired, there are PCI configurations setup by system BIOS that may not enable that to occur. Three files are created if a PCIe device has SRIOV support: sriov_totalvfs -- cat-ing this file returns the maximum number of VFs a PCIe device supports as reported by the TotalVFs in the SRIOV ext cap structure. sriov_numvfs -- echo'ing a positive number to this file enables this number of VFs for this given PCIe device. -- echo'ing a 0 to this file disables any previously enabled VFs for this PCIe device. -- cat-ing this file will return the number of VFs currently enabled on this PCIe device, i.e., the NumVFs field in SRIOV ext. cap structure. VF enable and disablement is invoked much like other PCIe configuration functions -- via registered callbacks in the driver, i.e., probe, release, etc. Signed-off-by: Donald Dutile --- drivers/pci/pci-sysfs.c | 134 ++++++++++++++++++++++++++++++++++++++++++++++++ include/linux/pci.h | 1 + 2 files changed, 135 insertions(+) diff --git a/drivers/pci/pci-sysfs.c b/drivers/pci/pci-sysfs.c index fbbb97f..cbcdd8d 100644 --- a/drivers/pci/pci-sysfs.c +++ b/drivers/pci/pci-sysfs.c @@ -404,6 +404,113 @@ static ssize_t d3cold_allowed_show(struct device *dev, } #endif +#ifdef CONFIG_PCI_IOV +static ssize_t sriov_totalvfs_show(struct device *dev, + struct device_attribute *attr, + char *buf) +{ + struct pci_dev *pdev; + u16 total; + + pdev = to_pci_dev(dev); + total = pdev->sriov->total; + return sprintf(buf, "%u\n", total); +} + + +static ssize_t sriov_numvfs_show(struct device *dev, + struct device_attribute *attr, + char *buf) +{ + struct pci_dev *pdev; + + pdev = to_pci_dev(dev); + + return sprintf(buf, "%u\n", pdev->sriov->nr_virtfn); +} + +/* + * num_vfs > 0; number of vfs to enable + * num_vfs = 0; disable all vfs + * + * Note: SRIOV spec doesn't allow partial VF + * disable, so its all or none. + */ +static ssize_t sriov_numvfs_store(struct device *dev, + struct device_attribute *attr, + const char *buf, size_t count) +{ + struct pci_dev *pdev; + int num_vfs_enabled = 0; + int num_vfs; + int ret = 0; + u16 total; + + pdev = to_pci_dev(dev); + + if (kstrtoint(buf, 0, &num_vfs) < 0) + return -EINVAL; + + /* is PF driver loaded w/callback */ + if (!pdev->driver || !pdev->driver->sriov_configure) { + dev_info(&pdev->dev, + "Driver doesn't support SRIOV configuration via sysfs\n"); + return -ENOSYS; + } + + /* if enabling vf's ... */ + total = pdev->sriov->total; + /* Requested VFs to enable < totalvfs and none enabled already */ + if ((num_vfs > 0) && (num_vfs <= total)) { + if (pdev->sriov->nr_virtfn == 0) { + num_vfs_enabled = + pdev->driver->sriov_configure(pdev, num_vfs); + if ((num_vfs_enabled >= 0) && + (num_vfs_enabled != num_vfs)) { + dev_warn(&pdev->dev, + "Only %d VFs enabled\n", + num_vfs_enabled); + return count; + } else if (num_vfs_enabled < 0) + /* error code from driver callback */ + return num_vfs_enabled; + } else if (num_vfs == pdev->sriov->nr_virtfn) { + dev_warn(&pdev->dev, + "%d VFs already enabled; no enable action taken\n", + num_vfs); + return count; + } else { + dev_warn(&pdev->dev, + "%d VFs already enabled. Disable before enabling %d VFs\n", + pdev->sriov->nr_virtfn, num_vfs); + return -EINVAL; + } + } + + /* disable vfs */ + if (num_vfs == 0) { + if (pdev->sriov->nr_virtfn != 0) { + ret = pdev->driver->sriov_configure(pdev, 0); + return ret ? ret : count; + } else { + dev_warn(&pdev->dev, + "All VFs disabled; no disable action taken\n"); + return count; + } + } + + dev_err(&pdev->dev, + "Invalid value for number of VFs to enable: %d\n", num_vfs); + + return -EINVAL; +} + +static struct device_attribute sriov_totalvfs_attr = __ATTR_RO(sriov_totalvfs); +static struct device_attribute sriov_numvfs_attr = + __ATTR(sriov_numvfs, (S_IRUGO|S_IWUSR|S_IWGRP), + sriov_numvfs_show, sriov_numvfs_store); +#endif /* CONFIG_PCI_IOV */ + struct device_attribute pci_dev_attrs[] = { __ATTR_RO(resource), __ATTR_RO(vendor), @@ -1421,6 +1528,30 @@ static umode_t pci_dev_attrs_are_visible(struct kobject *kobj, return a->mode; } +#ifdef CONFIG_PCI_IOV +static struct attribute *sriov_dev_attrs[] = { + &sriov_totalvfs_attr.attr, + &sriov_numvfs_attr.attr, + NULL, +}; + +static umode_t sriov_attrs_are_visible(struct kobject *kobj, + struct attribute *a, int n) +{ + struct device *dev = container_of(kobj, struct device, kobj); + + if (!dev_is_pf(dev)) + return 0; + + return a->mode; +} + +static struct attribute_group sriov_dev_attr_group = { + .attrs = sriov_dev_attrs, + .is_visible = sriov_attrs_are_visible, +}; +#endif /* CONFIG_PCI_IOV */ + static struct attribute_group pci_dev_attr_group = { .attrs = pci_dev_dev_attrs, .is_visible = pci_dev_attrs_are_visible, @@ -1428,6 +1559,9 @@ static struct attribute_group pci_dev_attr_group = { static const struct attribute_group *pci_dev_attr_groups[] = { &pci_dev_attr_group, +#ifdef CONFIG_PCI_IOV + &sriov_dev_attr_group, +#endif NULL, }; diff --git a/include/linux/pci.h b/include/linux/pci.h index ee21795..7ef8fba 100644 --- a/include/linux/pci.h +++ b/include/linux/pci.h @@ -573,6 +573,7 @@ struct pci_driver { int (*resume_early) (struct pci_dev *dev); int (*resume) (struct pci_dev *dev); /* Device woken up */ void (*shutdown) (struct pci_dev *dev); + int (*sriov_configure) (struct pci_dev *dev, int num_vfs); /* PF pdev */ const struct pci_error_handlers *err_handler; struct device_driver driver; struct pci_dynids dynids;