+#ifdef CONFIG_PCI_IOV
+static ssize_t sriov_totalvfs_show(struct device *dev,
+ struct device_attribute *attr,
+ char *buf)
+{
+ struct pci_dev *pdev = to_pci_dev(dev);
+
+ return sprintf(buf, "%u\n", pci_sriov_get_totalvfs(pdev));
+}
+
+
+static ssize_t sriov_numvfs_show(struct device *dev,
+ struct device_attribute *attr,
+ char *buf)
+{
+ struct pci_dev *pdev = to_pci_dev(dev);
+
+ return sprintf(buf, "%u\n", pdev->sriov->num_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.
+ */
+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;
+
+ 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 = 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;
+ }
+ }
+
+ 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 */
+