Merge branch 'next' (accumulated 3.16 merge window patches) into master

Now that 3.15 is released, this merges the 'next' branch into 'master',
bringing us to the normal situation where my 'master' branch is the
merge window.

* accumulated work in next: (6809 commits)
  ufs: sb mutex merge + mutex_destroy
  powerpc: update comments for generic idle conversion
  cris: update comments for generic idle conversion
  idle: remove cpu_idle() forward declarations
  nbd: zero from and len fields in NBD_CMD_DISCONNECT.
  mm: convert some level-less printks to pr_*
  MAINTAINERS: adi-buildroot-devel is moderated
  MAINTAINERS: add linux-api for review of API/ABI changes
  mm/kmemleak-test.c: use pr_fmt for logging
  fs/dlm/debug_fs.c: replace seq_printf by seq_puts
  fs/dlm/lockspace.c: convert simple_str to kstr
  fs/dlm/config.c: convert simple_str to kstr
  mm: mark remap_file_pages() syscall as deprecated
  mm: memcontrol: remove unnecessary memcg argument from soft limit functions
  mm: memcontrol: clean up memcg zoneinfo lookup
  mm/memblock.c: call kmemleak directly from memblock_(alloc|free)
  mm/mempool.c: update the kmemleak stack trace for mempool allocations
  lib/radix-tree.c: update the kmemleak stack trace for radix tree allocations
  mm: introduce kmemleak_update_trace()
  mm/kmemleak.c: use %u to print ->checksum
  ...

1 files changed, 268 insertions, 21 deletions

diff --git a/drivers/usb/core/port.c b/drivers/usb/core/port.c
index 51542f85239..62036faf56c 100644
--- a/drivers/usb/core/port.c
+++ b/drivers/usb/core/port.c
@@ -76,17 +76,29 @@ static int usb_port_runtime_resume(struct device *dev)
 	struct usb_device *hdev = to_usb_device(dev->parent->parent);
 	struct usb_interface *intf = to_usb_interface(dev->parent);
 	struct usb_hub *hub = usb_hub_to_struct_hub(hdev);
+	struct usb_device *udev = port_dev->child;
+	struct usb_port *peer = port_dev->peer;
 	int port1 = port_dev->portnum;
 	int retval;
 
 	if (!hub)
 		return -EINVAL;
+	if (hub->in_reset) {
+		set_bit(port1, hub->power_bits);
+		return 0;
+	}
 
-	usb_autopm_get_interface(intf);
-	set_bit(port1, hub->busy_bits);
+	/*
+	 * Power on our usb3 peer before this usb2 port to prevent a usb3
+	 * device from degrading to its usb2 connection
+	 */
+	if (!port_dev->is_superspeed && peer)
+		pm_runtime_get_sync(&peer->dev);
 
+	usb_autopm_get_interface(intf);
 	retval = usb_hub_set_port_power(hdev, hub, port1, true);
-	if (port_dev->child && !retval) {
+	msleep(hub_power_on_good_delay(hub));
+	if (udev && !retval) {
 		/*
 		 * Attempt to wait for usb hub port to be reconnected in order
 		 * to make the resume procedure successful.  The device may have
@@ -97,12 +109,17 @@ static int usb_port_runtime_resume(struct device *dev)
 		if (retval < 0)
 			dev_dbg(&port_dev->dev, "can't get reconnection after setting port  power on, status %d\n",
 					retval);
-		usb_clear_port_feature(hdev, port1, USB_PORT_FEAT_C_ENABLE);
 		retval = 0;
+
+		/* Force the child awake to revalidate after the power loss. */
+		if (!test_and_set_bit(port1, hub->child_usage_bits)) {
+			pm_runtime_get_noresume(&port_dev->dev);
+			pm_request_resume(&udev->dev);
+		}
 	}
 
-	clear_bit(port1, hub->busy_bits);
 	usb_autopm_put_interface(intf);
+
 	return retval;
 }
 
@@ -112,23 +129,34 @@ static int usb_port_runtime_suspend(struct device *dev)
 	struct usb_device *hdev = to_usb_device(dev->parent->parent);
 	struct usb_interface *intf = to_usb_interface(dev->parent);
 	struct usb_hub *hub = usb_hub_to_struct_hub(hdev);
+	struct usb_port *peer = port_dev->peer;
 	int port1 = port_dev->portnum;
 	int retval;
 
 	if (!hub)
 		return -EINVAL;
+	if (hub->in_reset)
+		return -EBUSY;
 
 	if (dev_pm_qos_flags(&port_dev->dev, PM_QOS_FLAG_NO_POWER_OFF)
 			== PM_QOS_FLAGS_ALL)
 		return -EAGAIN;
 
 	usb_autopm_get_interface(intf);
-	set_bit(port1, hub->busy_bits);
 	retval = usb_hub_set_port_power(hdev, hub, port1, false);
 	usb_clear_port_feature(hdev, port1, USB_PORT_FEAT_C_CONNECTION);
-	usb_clear_port_feature(hdev, port1,	USB_PORT_FEAT_C_ENABLE);
-	clear_bit(port1, hub->busy_bits);
+	if (!port_dev->is_superspeed)
+		usb_clear_port_feature(hdev, port1, USB_PORT_FEAT_C_ENABLE);
 	usb_autopm_put_interface(intf);
+
+	/*
+	 * Our peer usb3 port may now be able to suspend, so
+	 * asynchronously queue a suspend request to observe that this
+	 * usb2 port is now off.
+	 */
+	if (!port_dev->is_superspeed && peer)
+		pm_runtime_put(&peer->dev);
+
 	return retval;
 }
 #endif
@@ -146,9 +174,215 @@ struct device_type usb_port_device_type = {
 	.pm =		&usb_port_pm_ops,
 };
 
+static struct device_driver usb_port_driver = {
+	.name = "usb",
+	.owner = THIS_MODULE,
+};
+
+static int link_peers(struct usb_port *left, struct usb_port *right)
+{
+	struct usb_port *ss_port, *hs_port;
+	int rc;
+
+	if (left->peer == right && right->peer == left)
+		return 0;
+
+	if (left->peer || right->peer) {
+		struct usb_port *lpeer = left->peer;
+		struct usb_port *rpeer = right->peer;
+
+		WARN(1, "failed to peer %s and %s (%s -> %p) (%s -> %p)\n",
+			dev_name(&left->dev), dev_name(&right->dev),
+			dev_name(&left->dev), lpeer,
+			dev_name(&right->dev), rpeer);
+		return -EBUSY;
+	}
+
+	rc = sysfs_create_link(&left->dev.kobj, &right->dev.kobj, "peer");
+	if (rc)
+		return rc;
+	rc = sysfs_create_link(&right->dev.kobj, &left->dev.kobj, "peer");
+	if (rc) {
+		sysfs_remove_link(&left->dev.kobj, "peer");
+		return rc;
+	}
+
+	/*
+	 * We need to wake the HiSpeed port to make sure we don't race
+	 * setting ->peer with usb_port_runtime_suspend().  Otherwise we
+	 * may miss a suspend event for the SuperSpeed port.
+	 */
+	if (left->is_superspeed) {
+		ss_port = left;
+		WARN_ON(right->is_superspeed);
+		hs_port = right;
+	} else {
+		ss_port = right;
+		WARN_ON(!right->is_superspeed);
+		hs_port = left;
+	}
+	pm_runtime_get_sync(&hs_port->dev);
+
+	left->peer = right;
+	right->peer = left;
+
+	/*
+	 * The SuperSpeed reference is dropped when the HiSpeed port in
+	 * this relationship suspends, i.e. when it is safe to allow a
+	 * SuperSpeed connection to drop since there is no risk of a
+	 * device degrading to its powered-off HiSpeed connection.
+	 *
+	 * Also, drop the HiSpeed ref taken above.
+	 */
+	pm_runtime_get_sync(&ss_port->dev);
+	pm_runtime_put(&hs_port->dev);
+
+	return 0;
+}
+
+static void link_peers_report(struct usb_port *left, struct usb_port *right)
+{
+	int rc;
+
+	rc = link_peers(left, right);
+	if (rc == 0) {
+		dev_dbg(&left->dev, "peered to %s\n", dev_name(&right->dev));
+	} else {
+		dev_warn(&left->dev, "failed to peer to %s (%d)\n",
+				dev_name(&right->dev), rc);
+		pr_warn_once("usb: port power management may be unreliable\n");
+	}
+}
+
+static void unlink_peers(struct usb_port *left, struct usb_port *right)
+{
+	struct usb_port *ss_port, *hs_port;
+
+	WARN(right->peer != left || left->peer != right,
+			"%s and %s are not peers?\n",
+			dev_name(&left->dev), dev_name(&right->dev));
+
+	/*
+	 * We wake the HiSpeed port to make sure we don't race its
+	 * usb_port_runtime_resume() event which takes a SuperSpeed ref
+	 * when ->peer is !NULL.
+	 */
+	if (left->is_superspeed) {
+		ss_port = left;
+		hs_port = right;
+	} else {
+		ss_port = right;
+		hs_port = left;
+	}
+
+	pm_runtime_get_sync(&hs_port->dev);
+
+	sysfs_remove_link(&left->dev.kobj, "peer");
+	right->peer = NULL;
+	sysfs_remove_link(&right->dev.kobj, "peer");
+	left->peer = NULL;
+
+	/* Drop the SuperSpeed ref held on behalf of the active HiSpeed port */
+	pm_runtime_put(&ss_port->dev);
+
+	/* Drop the ref taken above */
+	pm_runtime_put(&hs_port->dev);
+}
+
+/*
+ * For each usb hub device in the system check to see if it is in the
+ * peer domain of the given port_dev, and if it is check to see if it
+ * has a port that matches the given port by location
+ */
+static int match_location(struct usb_device *peer_hdev, void *p)
+{
+	int port1;
+	struct usb_hcd *hcd, *peer_hcd;
+	struct usb_port *port_dev = p, *peer;
+	struct usb_hub *peer_hub = usb_hub_to_struct_hub(peer_hdev);
+	struct usb_device *hdev = to_usb_device(port_dev->dev.parent->parent);
+
+	if (!peer_hub)
+		return 0;
+
+	hcd = bus_to_hcd(hdev->bus);
+	peer_hcd = bus_to_hcd(peer_hdev->bus);
+	/* peer_hcd is provisional until we verify it against the known peer */
+	if (peer_hcd != hcd->shared_hcd)
+		return 0;
+
+	for (port1 = 1; port1 <= peer_hdev->maxchild; port1++) {
+		peer = peer_hub->ports[port1 - 1];
+		if (peer && peer->location == port_dev->location) {
+			link_peers_report(port_dev, peer);
+			return 1; /* done */
+		}
+	}
+
+	return 0;
+}
+
+/*
+ * Find the peer port either via explicit platform firmware "location"
+ * data, the peer hcd for root hubs, or the upstream peer relationship
+ * for all other hubs.
+ */
+static void find_and_link_peer(struct usb_hub *hub, int port1)
+{
+	struct usb_port *port_dev = hub->ports[port1 - 1], *peer;
+	struct usb_device *hdev = hub->hdev;
+	struct usb_device *peer_hdev;
+	struct usb_hub *peer_hub;
+
+	/*
+	 * If location data is available then we can only peer this port
+	 * by a location match, not the default peer (lest we create a
+	 * situation where we need to go back and undo a default peering
+	 * when the port is later peered by location data)
+	 */
+	if (port_dev->location) {
+		/* we link the peer in match_location() if found */
+		usb_for_each_dev(port_dev, match_location);
+		return;
+	} else if (!hdev->parent) {
+		struct usb_hcd *hcd = bus_to_hcd(hdev->bus);
+		struct usb_hcd *peer_hcd = hcd->shared_hcd;
+
+		if (!peer_hcd)
+			return;
+
+		peer_hdev = peer_hcd->self.root_hub;
+	} else {
+		struct usb_port *upstream;
+		struct usb_device *parent = hdev->parent;
+		struct usb_hub *parent_hub = usb_hub_to_struct_hub(parent);
+
+		if (!parent_hub)
+			return;
+
+		upstream = parent_hub->ports[hdev->portnum - 1];
+		if (!upstream || !upstream->peer)
+			return;
+
+		peer_hdev = upstream->peer->child;
+	}
+
+	peer_hub = usb_hub_to_struct_hub(peer_hdev);
+	if (!peer_hub || port1 > peer_hdev->maxchild)
+		return;
+
+	/*
+	 * we found a valid default peer, last check is to make sure it
+	 * does not have location data
+	 */
+	peer = peer_hub->ports[port1 - 1];
+	if (peer && peer->location == 0)
+		link_peers_report(port_dev, peer);
+}
+
 int usb_hub_create_port_device(struct usb_hub *hub, int port1)
 {
-	struct usb_port *port_dev = NULL;
+	struct usb_port *port_dev;
 	int retval;
 
 	port_dev = kzalloc(sizeof(*port_dev), GFP_KERNEL);
@@ -159,24 +393,33 @@ int usb_hub_create_port_device(struct usb_hub *hub, int port1)
 
 	hub->ports[port1 - 1] = port_dev;
 	port_dev->portnum = port1;
-	port_dev->power_is_on = true;
+	set_bit(port1, hub->power_bits);
 	port_dev->dev.parent = hub->intfdev;
 	port_dev->dev.groups = port_dev_group;
 	port_dev->dev.type = &usb_port_device_type;
-	dev_set_name(&port_dev->dev, "port%d", port1);
-
+	port_dev->dev.driver = &usb_port_driver;
+	if (hub_is_superspeed(hub->hdev))
+		port_dev->is_superspeed = 1;
+	dev_set_name(&port_dev->dev, "%s-port%d", dev_name(&hub->hdev->dev),
+			port1);
+	mutex_init(&port_dev->status_lock);
 	retval = device_register(&port_dev->dev);
 	if (retval)
 		goto error_register;
 
+	find_and_link_peer(hub, port1);
+
 	pm_runtime_set_active(&port_dev->dev);
 
-	/* It would be dangerous if user space couldn't
-	 * prevent usb device from being powered off. So don't
-	 * enable port runtime pm if failed to expose port's pm qos.
+	/*
+	 * Do not enable port runtime pm if the hub does not support
+	 * power switching.  Also, userspace must have final say of
+	 * whether a port is permitted to power-off.  Do not enable
+	 * runtime pm if we fail to expose pm_qos_no_power_off.
 	 */
-	if (!dev_pm_qos_expose_flags(&port_dev->dev,
-			PM_QOS_FLAG_NO_POWER_OFF))
+	if (hub_is_port_power_switchable(hub)
+			&& dev_pm_qos_expose_flags(&port_dev->dev,
+			PM_QOS_FLAG_NO_POWER_OFF) == 0)
 		pm_runtime_enable(&port_dev->dev);
 
 	device_enable_async_suspend(&port_dev->dev);
@@ -188,9 +431,13 @@ exit:
 	return retval;
 }
 
-void usb_hub_remove_port_device(struct usb_hub *hub,
-				       int port1)
+void usb_hub_remove_port_device(struct usb_hub *hub, int port1)
 {
-	device_unregister(&hub->ports[port1 - 1]->dev);
-}
+	struct usb_port *port_dev = hub->ports[port1 - 1];
+	struct usb_port *peer;
 
+	peer = port_dev->peer;
+	if (peer)
+		unlink_peers(port_dev, peer);
+	device_unregister(&port_dev->dev);
+}