From faa48a507fd328013886426f9437fd7e2e7b820b Mon Sep 17 00:00:00 2001 From: Bjorn Helgaas Date: Wed, 26 Dec 2012 10:39:22 -0700 Subject: [PATCH] PCI: Remove spurious error for sriov_numvfs store and simplify flow If we request "num_vfs" and the driver's sriov_configure() method enables exactly that number ("num_vfs_enabled"), we complain "Invalid value for number of VFs to enable" and return an error. We should silently return success instead. Also, use kstrtou16() since numVFs is defined to be a 16-bit field and rework to simplify control flow. Reported-by: Greg Rose Reference: http://lkml.kernel.org/r/20121214101911.00002f59@unknown Signed-off-by: Bjorn Helgaas Tested-by: Donald Dutile --- drivers/pci/pci-sysfs.c | 87 +++++++++++++++++------------------------ 1 file changed, 35 insertions(+), 52 deletions(-) diff --git a/drivers/pci/pci-sysfs.c b/drivers/pci/pci-sysfs.c index 05b78b16d20b..9c6e9bb674ec 100644 --- a/drivers/pci/pci-sysfs.c +++ b/drivers/pci/pci-sysfs.c @@ -422,77 +422,60 @@ static ssize_t sriov_numvfs_show(struct device *dev, } /* - * num_vfs > 0; number of vfs to enable - * num_vfs = 0; disable all vfs + * 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. + * disable, so it's 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 = to_pci_dev(dev); - int num_vfs_enabled = 0; - int num_vfs; - int ret = 0; - u16 total; + int ret; + u16 num_vfs; - if (kstrtoint(buf, 0, &num_vfs) < 0) - return -EINVAL; + ret = kstrtou16(buf, 0, &num_vfs); + if (ret < 0) + return ret; + + if (num_vfs > pci_sriov_get_totalvfs(pdev)) + return -ERANGE; + + if (num_vfs == pdev->sriov->num_VFs) + return count; /* no change */ /* 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"); + dev_info(&pdev->dev, "Driver doesn't support SRIOV configuration via sysfs\n"); return -ENOSYS; } - /* if enabling vf's ... */ - total = pci_sriov_get_totalvfs(pdev); - /* Requested VFs to enable < totalvfs and none enabled already */ - if ((num_vfs > 0) && (num_vfs <= total)) { - if (pdev->sriov->num_VFs == 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->num_VFs) { - 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->num_VFs, num_vfs); - return -EINVAL; - } - } - - /* disable vfs */ if (num_vfs == 0) { - if (pdev->sriov->num_VFs != 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; - } + /* disable VFs */ + ret = pdev->driver->sriov_configure(pdev, 0); + if (ret < 0) + return ret; + return count; } - dev_err(&pdev->dev, - "Invalid value for number of VFs to enable: %d\n", num_vfs); + /* enable VFs */ + if (pdev->sriov->num_VFs) { + dev_warn(&pdev->dev, "%d VFs already enabled. Disable before enabling %d VFs\n", + pdev->sriov->num_VFs, num_vfs); + return -EBUSY; + } - return -EINVAL; + ret = pdev->driver->sriov_configure(pdev, num_vfs); + if (ret < 0) + return ret; + + if (ret != num_vfs) + dev_warn(&pdev->dev, "%d VFs requested; only %d enabled\n", + num_vfs, ret); + + return count; } static struct device_attribute sriov_totalvfs_attr = __ATTR_RO(sriov_totalvfs);