usb: move struct usb_device->children to struct usb_hub_port->child

Move child's pointer to the struct usb_hub_port since the child device
is directly associated with the port. Provide usb_get_hub_child_device()
to get child's pointer.

Signed-off-by: Lan Tianyu <tianyu.lan@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

5 files changed, 47 insertions, 33 deletions

diff --git a/drivers/staging/usbip/usbip_common.c b/drivers/staging/usbip/usbip_common.c
index 70f230269329..95beb76497d6 100644
--- a/drivers/staging/usbip/usbip_common.c
+++ b/drivers/staging/usbip/usbip_common.c
@@ -157,8 +157,7 @@ static void usbip_dump_usb_device(struct usb_device *udev)
         dev_dbg(dev, "have_langid %d, string_langid %d\n",
                 udev->have_langid, udev->string_langid);
 
-        dev_dbg(dev, "maxchild %d, children %p\n",
-                udev->maxchild, udev->children);
+        dev_dbg(dev, "maxchild %d\n", udev->maxchild);
 }
 
 static void usbip_dump_request_type(__u8 rt)
diff --git a/drivers/usb/core/devices.c b/drivers/usb/core/devices.c
index d95696584762..a83962b1ccee 100644
--- a/drivers/usb/core/devices.c
+++ b/drivers/usb/core/devices.c
@@ -590,7 +590,8 @@ static ssize_t usb_device_dump(char __user **buffer, size_t *nbytes,
 
         /* Now look at all of this device's children. */
         for (chix = 0; chix < usbdev->maxchild; chix++) {
-                struct usb_device *childdev = usbdev->children[chix];
+                struct usb_device *childdev =
+                        usb_get_hub_child_device(usbdev, chix + 1);
 
                 if (childdev) {
                         usb_lock_device(childdev);
diff --git a/drivers/usb/core/hub.c b/drivers/usb/core/hub.c
index 0c17d5a91d79..6bf7124fdf96 100644
--- a/drivers/usb/core/hub.c
+++ b/drivers/usb/core/hub.c
@@ -39,6 +39,7 @@
 
 struct usb_hub_port {
         void                    *port_owner;
+        struct usb_device       *child;
 };
 
 struct usb_hub {
@@ -93,7 +94,7 @@ static inline int hub_is_superspeed(struct usb_device *hdev)
         return (hdev->descriptor.bDeviceProtocol == USB_HUB_PR_SS);
 }
 
-/* Protect struct usb_device->state and ->children members
+/* Protect struct usb_device->state and struct usb_hub_port->child members
  * Note: Both are also protected by ->dev.sem, except that ->state can
  * change to USB_STATE_NOTATTACHED even when the semaphore isn't held. */
 static DEFINE_SPINLOCK(device_state_lock);
@@ -176,7 +177,7 @@ static inline char *portspeed(struct usb_hub *hub, int portstatus)
 /* Note that hdev or one of its children must be locked! */
 static struct usb_hub *hdev_to_hub(struct usb_device *hdev)
 {
-        if (!hdev || !hdev->actconfig)
+        if (!hdev || !hdev->actconfig || !hdev->maxchild)
                 return NULL;
         return usb_get_intfdata(hdev->actconfig->interface[0]);
 }
@@ -649,8 +650,8 @@ static int hub_port_disable(struct usb_hub *hub, int port1, int set_state)
         struct usb_device *hdev = hub->hdev;
         int ret = 0;
 
-        if (hdev->children[port1-1] && set_state)
-                usb_set_device_state(hdev->children[port1-1],
+        if (hub->port_data[port1-1].child && set_state)
+                usb_set_device_state(hub->port_data[port1-1].child,
                                 USB_STATE_NOTATTACHED);
         if (!hub->error && !hub_is_superspeed(hub->hdev))
                 ret = clear_port_feature(hdev, port1, USB_PORT_FEAT_ENABLE);
@@ -806,7 +807,7 @@ static void hub_activate(struct usb_hub *hub, enum hub_activation_type type)
          * which ports need attention.
          */
         for (port1 = 1; port1 <= hdev->maxchild; ++port1) {
-                struct usb_device *udev = hdev->children[port1-1];
+                struct usb_device *udev = hub->port_data[port1-1].child;
                 u16 portstatus, portchange;
 
                 portstatus = portchange = 0;
@@ -971,8 +972,8 @@ static void hub_quiesce(struct usb_hub *hub, enum hub_quiescing_type type)
         if (type != HUB_SUSPEND) {
                 /* Disconnect all the children */
                 for (i = 0; i < hdev->maxchild; ++i) {
-                        if (hdev->children[i])
-                                usb_disconnect(&hdev->children[i]);
+                        if (hub->port_data[i].child)
+                                usb_disconnect(&hub->port_data[i].child);
                 }
         }
 
@@ -1051,11 +1052,9 @@ static int hub_configure(struct usb_hub *hub,
         dev_info (hub_dev, "%d port%s detected\n", hdev->maxchild,
                 (hdev->maxchild == 1) ? "" : "s");
 
-        hdev->children = kzalloc(hdev->maxchild *
-                                sizeof(struct usb_device *), GFP_KERNEL);
         hub->port_data = kzalloc(hdev->maxchild * sizeof(struct usb_hub_port),
                         GFP_KERNEL);
-        if (!hub->port_data || !hdev->children) {
+        if (!hub->port_data) {
                 ret = -ENOMEM;
                 goto fail;
         }
@@ -1287,7 +1286,6 @@ static unsigned highspeed_hubs;
 static void hub_disconnect(struct usb_interface *intf)
 {
         struct usb_hub *hub = usb_get_intfdata(intf);
-        struct usb_device *hdev = interface_to_usbdev(intf);
 
         /* Take the hub off the event list and don't let it be added again */
         spin_lock_irq(&hub_event_lock);
@@ -1309,7 +1307,6 @@ static void hub_disconnect(struct usb_interface *intf)
                 highspeed_hubs--;
 
         usb_free_urb(hub->urb);
-        kfree(hdev->children);
         kfree(hub->port_data);
         kfree(hub->descriptor);
         kfree(hub->status);
@@ -1397,6 +1394,7 @@ static int
 hub_ioctl(struct usb_interface *intf, unsigned int code, void *user_data)
 {
         struct usb_device *hdev = interface_to_usbdev (intf);
+        struct usb_hub *hub = usb_get_intfdata(intf);
 
         /* assert ifno == 0 (part of hub spec) */
         switch (code) {
@@ -1410,11 +1408,11 @@ hub_ioctl(struct usb_interface *intf, unsigned int code, void *user_data)
                 else {
                         info->nports = hdev->maxchild;
                         for (i = 0; i < info->nports; i++) {
-                                if (hdev->children[i] == NULL)
+                                if (hub->port_data[i].child == NULL)
                                         info->port[i] = 0;
                                 else
                                         info->port[i] =
-                                                hdev->children[i]->devnum;
+                                                hub->port_data[i].child->devnum;
                         }
                 }
                 spin_unlock_irq(&device_state_lock);
@@ -1501,11 +1499,13 @@ bool usb_device_is_owned(struct usb_device *udev)
 
 static void recursively_mark_NOTATTACHED(struct usb_device *udev)
 {
+        struct usb_hub  *hub = hdev_to_hub(udev);
         int i;
 
         for (i = 0; i < udev->maxchild; ++i) {
-                if (udev->children[i])
-                        recursively_mark_NOTATTACHED(udev->children[i]);
+                if (hub->port_data[i].child)
+                        recursively_mark_NOTATTACHED(
+                                hub->port_data[i].child);
         }
         if (udev->state == USB_STATE_SUSPENDED)
                 udev->active_duration -= jiffies;
@@ -1669,6 +1669,7 @@ static void hub_free_dev(struct usb_device *udev)
 void usb_disconnect(struct usb_device **pdev)
 {
         struct usb_device       *udev = *pdev;
+        struct usb_hub  *hub = hdev_to_hub(udev);
         int                     i;
 
         /* mark the device as inactive, so any further urb submissions for
@@ -1683,8 +1684,8 @@ void usb_disconnect(struct usb_device **pdev)
 
         /* Free up all the children before we remove this device */
         for (i = 0; i < udev->maxchild; i++) {
-                if (udev->children[i])
-                        usb_disconnect(&udev->children[i]);
+                if (hub->port_data[i].child)
+                        usb_disconnect(&hub->port_data[i].child);
         }
 
         /* deallocate hcd/hardware state ... nuking all pending urbs and
@@ -2765,7 +2766,7 @@ static int hub_suspend(struct usb_interface *intf, pm_message_t msg)
         for (port1 = 1; port1 <= hdev->maxchild; port1++) {
                 struct usb_device       *udev;
 
-                udev = hdev->children [port1-1];
+                udev = hub->port_data[port1-1].child;
                 if (udev && udev->can_submit) {
                         dev_warn(&intf->dev, "port %d nyet suspended\n", port1);
                         if (PMSG_IS_AUTO(msg))
@@ -3266,7 +3267,7 @@ hub_power_remaining (struct usb_hub *hub)
 
         remaining = hdev->bus_mA - hub->descriptor->bHubContrCurrent;
         for (port1 = 1; port1 <= hdev->maxchild; ++port1) {
-                struct usb_device       *udev = hdev->children[port1 - 1];
+                struct usb_device       *udev = hub->port_data[port1 - 1].child;
                 int                     delta;
 
                 if (!udev)
@@ -3330,7 +3331,7 @@ static void hub_port_connect_change(struct usb_hub *hub, int port1,
 #endif
 
         /* Try to resuscitate an existing device */
-        udev = hdev->children[port1-1];
+        udev = hub->port_data[port1-1].child;
         if ((portstatus & USB_PORT_STAT_CONNECTION) && udev &&
                         udev->state != USB_STATE_NOTATTACHED) {
                 usb_lock_device(udev);
@@ -3359,7 +3360,7 @@ static void hub_port_connect_change(struct usb_hub *hub, int port1,
 
         /* Disconnect any existing devices under this port */
         if (udev)
-                usb_disconnect(&hdev->children[port1-1]);
+                usb_disconnect(&hub->port_data[port1-1].child);
         clear_bit(port1, hub->change_bits);
 
         /* We can forget about a "removed" device when there's a physical
@@ -3474,7 +3475,7 @@ static void hub_port_connect_change(struct usb_hub *hub, int port1,
                                 && highspeed_hubs != 0)
                         check_highspeed (hub, udev, port1);
 
-                /* Store the parent's children[] pointer.  At this point
+                /* Store the hub port's child pointer.  At this point
                  * udev becomes globally accessible, although presumably
                  * no one will look at it until hdev is unlocked.
                  */
@@ -3488,7 +3489,7 @@ static void hub_port_connect_change(struct usb_hub *hub, int port1,
                 if (hdev->state == USB_STATE_NOTATTACHED)
                         status = -ENOTCONN;
                 else
-                        hdev->children[port1-1] = udev;
+                        hub->port_data[port1-1].child = udev;
                 spin_unlock_irq(&device_state_lock);
 
                 /* Run it through the hoops (find a driver, etc) */
@@ -3496,7 +3497,7 @@ static void hub_port_connect_change(struct usb_hub *hub, int port1,
                         status = usb_new_device(udev);
                         if (status) {
                                 spin_lock_irq(&device_state_lock);
-                                hdev->children[port1-1] = NULL;
+                                hub->port_data[port1-1].child = NULL;
                                 spin_unlock_irq(&device_state_lock);
                         }
                 }
@@ -3542,7 +3543,7 @@ static int hub_handle_remote_wakeup(struct usb_hub *hub, unsigned int port,
         int ret;
 
         hdev = hub->hdev;
-        udev = hdev->children[port-1];
+        udev = hub->port_data[port - 1].child;
         if (!hub_is_superspeed(hdev)) {
                 if (!(portchange & USB_PORT_STAT_C_SUSPEND))
                         return 0;
@@ -3696,7 +3697,7 @@ static void hub_events(void)
                                  */
                                 if (!(portstatus & USB_PORT_STAT_ENABLE)
                                     && !connect_change
-                                    && hdev->children[i-1]) {
+                                    && hub->port_data[i-1].child) {
                                         dev_err (hub_dev,
                                             "port %i "
                                             "disabled by hub (EMI?), "
@@ -4234,3 +4235,15 @@ void usb_queue_reset_device(struct usb_interface *iface)
         schedule_work(&iface->reset_ws);
 }
 EXPORT_SYMBOL_GPL(usb_queue_reset_device);
+
+struct usb_device *usb_get_hub_child_device(struct usb_device *hdev,
+        int port1)
+{
+        struct usb_hub *hub = hdev_to_hub(hdev);
+
+        if (!hub || port1 > hdev->maxchild || port1 < 1)
+                return NULL;
+        return hub->port_data[port1 - 1].child;
+}
+EXPORT_SYMBOL_GPL(usb_get_hub_child_device);
+
diff --git a/drivers/usb/host/r8a66597-hcd.c b/drivers/usb/host/r8a66597-hcd.c
index c868be65e763..4c82fdf5494f 100644
--- a/drivers/usb/host/r8a66597-hcd.c
+++ b/drivers/usb/host/r8a66597-hcd.c
@@ -2040,7 +2040,8 @@ static void collect_usb_address_map(struct usb_device *udev, unsigned long *map)
                 map[udev->devnum/32] |= (1 << (udev->devnum % 32));
 
         for (chix = 0; chix < udev->maxchild; chix++) {
-                struct usb_device *childdev = udev->children[chix];
+                struct usb_device *childdev =
+                        usb_get_hub_child_device(udev, chix + 1);
 
                 if (childdev)
                         collect_usb_address_map(childdev, map);
diff --git a/include/linux/usb.h b/include/linux/usb.h
index 5483cd70390b..69163a0abe91 100644
--- a/include/linux/usb.h
+++ b/include/linux/usb.h
@@ -424,7 +424,6 @@ enum usb_device_removable {
  *      access from userspace
  * @usbfs_dentry: usbfs dentry entry for the device
  * @maxchild: number of ports if hub
- * @children: child devices - USB devices that are attached to this hub
  * @quirks: quirks of the whole device
  * @urbnum: number of URBs submitted for the whole device
  * @active_duration: total time device is not suspended
@@ -491,7 +490,6 @@ struct usb_device {
         struct list_head filelist;
 
         int maxchild;
-        struct usb_device **children;
 
         u32 quirks;
         atomic_t urbnum;
@@ -517,6 +515,8 @@ static inline struct usb_device *interface_to_usbdev(struct usb_interface *intf)
 
 extern struct usb_device *usb_get_dev(struct usb_device *dev);
 extern void usb_put_dev(struct usb_device *dev);
+extern struct usb_device *usb_get_hub_child_device(struct usb_device *hdev,
+        int port1);
 
 /* USB device locking */
 #define usb_lock_device(udev)           device_lock(&(udev)->dev)