1 files changed, 49 insertions, 27 deletions

diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
index b717680377a9..aacf575c15cf 100644
--- a/drivers/pci/pci.c
+++ b/drivers/pci/pci.c
@@ -1900,11 +1900,21 @@ static int pci_enable_device_flags(struct pci_dev *dev, unsigned long flags)
 	int err;
 	int i, bars = 0;
 
-	if (atomic_inc_return(&dev->enable_cnt) > 1) {
-		pci_update_current_state(dev, dev->current_state);
-		return 0;		/* already enabled */
+	/*
+	 * Power state could be unknown at this point, either due to a fresh
+	 * boot or a device removal call.  So get the current power state
+	 * so that things like MSI message writing will behave as expected
+	 * (e.g. if the device really is in D0 at enable time).
+	 */
+	if (dev->pm_cap) {
+		u16 pmcsr;
+		pci_read_config_word(dev, dev->pm_cap + PCI_PM_CTRL, &pmcsr);
+		dev->current_state = (pmcsr & PCI_PM_CTRL_STATE_MASK);
 	}
 
+	if (atomic_inc_return(&dev->enable_cnt) > 1)
+		return 0;		/* already enabled */
+
 	bridge = pci_upstream_bridge(dev);
 	if (bridge)
 		pci_enable_bridge(bridge);
@@ -5020,6 +5030,16 @@ static int pci_dev_reset_slot_function(struct pci_dev *dev, int probe)
 	return pci_reset_hotplug_slot(dev->slot->hotplug, probe);
 }
 
+static int pci_reset_bus_function(struct pci_dev *dev, int probe)
+{
+	int rc;
+
+	rc = pci_dev_reset_slot_function(dev, probe);
+	if (rc != -ENOTTY)
+		return rc;
+	return pci_parent_bus_reset(dev, probe);
+}
+
 static void pci_dev_lock(struct pci_dev *dev)
 {
 	pci_cfg_access_lock(dev);
@@ -5028,7 +5048,7 @@ static void pci_dev_lock(struct pci_dev *dev)
 }
 
 /* Return 1 on successful lock, 0 on contention */
-static int pci_dev_trylock(struct pci_dev *dev)
+int pci_dev_trylock(struct pci_dev *dev)
 {
 	if (pci_cfg_access_trylock(dev)) {
 		if (device_trylock(&dev->dev))
@@ -5038,12 +5058,14 @@ static int pci_dev_trylock(struct pci_dev *dev)
 
 	return 0;
 }
+EXPORT_SYMBOL_GPL(pci_dev_trylock);
 
-static void pci_dev_unlock(struct pci_dev *dev)
+void pci_dev_unlock(struct pci_dev *dev)
 {
 	device_unlock(&dev->dev);
 	pci_cfg_access_unlock(dev);
 }
+EXPORT_SYMBOL_GPL(pci_dev_unlock);
 
 static void pci_dev_save_and_disable(struct pci_dev *dev)
 {
@@ -5140,10 +5162,7 @@ int __pci_reset_function_locked(struct pci_dev *dev)
 	rc = pci_pm_reset(dev, 0);
 	if (rc != -ENOTTY)
 		return rc;
-	rc = pci_dev_reset_slot_function(dev, 0);
-	if (rc != -ENOTTY)
-		return rc;
-	return pci_parent_bus_reset(dev, 0);
+	return pci_reset_bus_function(dev, 0);
 }
 EXPORT_SYMBOL_GPL(__pci_reset_function_locked);
 
@@ -5175,11 +5194,8 @@ int pci_probe_reset_function(struct pci_dev *dev)
 	rc = pci_pm_reset(dev, 1);
 	if (rc != -ENOTTY)
 		return rc;
-	rc = pci_dev_reset_slot_function(dev, 1);
-	if (rc != -ENOTTY)
-		return rc;
 
-	return pci_parent_bus_reset(dev, 1);
+	return pci_reset_bus_function(dev, 1);
 }
 
 /**
@@ -6439,34 +6455,40 @@ static ssize_t resource_alignment_show(struct bus_type *bus, char *buf)
 
 	spin_lock(&resource_alignment_lock);
 	if (resource_alignment_param)
-		count = scnprintf(buf, PAGE_SIZE, "%s", resource_alignment_param);
+		count = sysfs_emit(buf, "%s\n", resource_alignment_param);
 	spin_unlock(&resource_alignment_lock);
 
-	/*
-	 * When set by the command line, resource_alignment_param will not
-	 * have a trailing line feed, which is ugly. So conditionally add
-	 * it here.
-	 */
-	if (count >= 2 && buf[count - 2] != '\n' && count < PAGE_SIZE - 1) {
-		buf[count - 1] = '\n';
-		buf[count++] = 0;
-	}
-
 	return count;
 }
 
 static ssize_t resource_alignment_store(struct bus_type *bus,
 					const char *buf, size_t count)
 {
-	char *param = kstrndup(buf, count, GFP_KERNEL);
+	char *param, *old, *end;
 
+	if (count >= (PAGE_SIZE - 1))
+		return -EINVAL;
+
+	param = kstrndup(buf, count, GFP_KERNEL);
 	if (!param)
 		return -ENOMEM;
 
+	end = strchr(param, '\n');
+	if (end)
+		*end = '\0';
+
 	spin_lock(&resource_alignment_lock);
-	kfree(resource_alignment_param);
-	resource_alignment_param = param;
+	old = resource_alignment_param;
+	if (strlen(param)) {
+		resource_alignment_param = param;
+	} else {
+		kfree(param);
+		resource_alignment_param = NULL;
+	}
 	spin_unlock(&resource_alignment_lock);
+
+	kfree(old);
+
 	return count;
 }