Merge branch 'pci/vpd'

- Ensure device is accessible before VPD access via sysfs (Alex Williamson)

- Ensure device doesn't go to a low-power state while we're polling for PME
  (Alex Williamson)

* pci/vpd:
  PCI: Fix runtime PM race with PME polling
  PCI/VPD: Add runtime power management to sysfs interface

Author: bjorn-helgaas

drivers/pci/pci.c

@@ -2420,25 +2420,34 @@ static void pci_pme_list_scan(struct work_struct *work)
 
 	mutex_lock(&pci_pme_list_mutex);
 	list_for_each_entry_safe(pme_dev, n, &pci_pme_list, list) {
-		if (pme_dev->dev->pme_poll) {
-			struct pci_dev *bridge;
+		struct pci_dev *pdev = pme_dev->dev;
+
+		if (pdev->pme_poll) {
+			struct pci_dev *bridge = pdev->bus->self;
+			struct device *dev = &pdev->dev;
+			int pm_status;
 
-			bridge = pme_dev->dev->bus->self;
 			/*
 			 * If bridge is in low power state, the
 			 * configuration space of subordinate devices
 			 * may be not accessible
 			 */
 			if (bridge && bridge->current_state != PCI_D0)
 				continue;
+
 			/*
-			 * If the device is in D3cold it should not be
-			 * polled either.
+			 * If the device is in a low power state it
+			 * should not be polled either.
 			 */
-			if (pme_dev->dev->current_state == PCI_D3cold)
+			pm_status = pm_runtime_get_if_active(dev, true);
+			if (!pm_status)
 				continue;
 
-			pci_pme_wakeup(pme_dev->dev, NULL);
+			if (pdev->current_state != PCI_D3cold)
+				pci_pme_wakeup(pdev, NULL);
+
+			if (pm_status > 0)
+				pm_runtime_put(dev);
 		} else {
 			list_del(&pme_dev->list);
 			kfree(pme_dev);

drivers/pci/vpd.c

@@ -275,17 +275,47 @@ 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->dev_flags & PCI_DEV_FLAGS_VPD_REF_F0)
+		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,
 			 struct bin_attribute *bin_attr, char *buf, loff_t off,
 			 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->dev_flags & PCI_DEV_FLAGS_VPD_REF_F0)
+		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);