5 files changed, 68 insertions, 35 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..f4ead1296820 100644
--- a/drivers/usb/core/devices.c
+++ b/drivers/usb/core/devices.c
@@ -496,6 +496,7 @@ static ssize_t usb_device_dump(char __user **buffer, size_t *nbytes,
         char *pages_start, *data_end, *speed;
         unsigned int length;
         ssize_t total_written = 0;
+        struct usb_device *childdev = NULL;
 
         /* don't bother with anything else if we're not writing any data */
         if (*nbytes <= 0)
@@ -589,14 +590,12 @@ static ssize_t usb_device_dump(char __user **buffer, size_t *nbytes,
         free_pages((unsigned long)pages_start, 1);
 
         /* Now look at all of this device's children. */
-        for (chix = 0; chix < usbdev->maxchild; chix++) {
-                struct usb_device *childdev = usbdev->children[chix];
-
+        usb_hub_for_each_child(usbdev, chix, childdev) {
                 if (childdev) {
                         usb_lock_device(childdev);
                         ret = usb_device_dump(buffer, nbytes, skip_bytes,
                                               file_offset, childdev, bus,
-                                              level + 1, chix, ++cnt);
+                                              level + 1, chix - 1, ++cnt);
                         usb_unlock_device(childdev);
                         if (ret == -EFAULT)
                                 return total_written;
diff --git a/drivers/usb/core/hub.c b/drivers/usb/core/hub.c
index 87df22eef491..cdbade148995 100644
--- a/drivers/usb/core/hub.c
+++ b/drivers/usb/core/hub.c
@@ -40,6 +40,7 @@
 #endif
 
 struct usb_port {
+        struct usb_device *child;
         struct device dev;
         struct dev_state *port_owner;
 };
@@ -181,7 +182,7 @@ 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]);
 }
@@ -876,8 +877,8 @@ 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->ports[port1 - 1]->child && set_state)
+                usb_set_device_state(hub->ports[port1 - 1]->child,
                                 USB_STATE_NOTATTACHED);
         if (!hub->error && !hub_is_superspeed(hub->hdev))
                 ret = clear_port_feature(hdev, port1, USB_PORT_FEAT_ENABLE);
@@ -1033,7 +1034,7 @@ 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->ports[port1 - 1]->child;
                 u16 portstatus, portchange;
 
                 portstatus = portchange = 0;
@@ -1198,8 +1199,8 @@ 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->ports[i]->child)
+                                usb_disconnect(&hub->ports[i]->child);
                 }
         }
 
@@ -1324,11 +1325,9 @@ 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->ports = kzalloc(hdev->maxchild * sizeof(struct usb_port *),
                              GFP_KERNEL);
-        if (!hdev->children || !hub->ports) {
+        if (!hub->ports) {
                 ret = -ENOMEM;
                 goto fail;
         }
@@ -1591,7 +1590,6 @@ static void hub_disconnect(struct usb_interface *intf)
                 highspeed_hubs--;
 
         usb_free_urb(hub->urb);
-        kfree(hdev->children);
         kfree(hub->ports);
         kfree(hub->descriptor);
         kfree(hub->status);
@@ -1679,6 +1677,7 @@ 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 = hdev_to_hub(hdev);
 
         /* assert ifno == 0 (part of hub spec) */
         switch (code) {
@@ -1692,11 +1691,11 @@ 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->ports[i]->child == NULL)
                                         info->port[i] = 0;
                                 else
                                         info->port[i] =
-                                                hdev->children[i]->devnum;
+                                                hub->ports[i]->child->devnum;
                         }
                 }
                 spin_unlock_irq(&device_state_lock);
@@ -1784,11 +1783,12 @@ 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->ports[i]->child)
+                        recursively_mark_NOTATTACHED(hub->ports[i]->child);
         }
         if (udev->state == USB_STATE_SUSPENDED)
                 udev->active_duration -= jiffies;
@@ -1952,6 +1952,7 @@ 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
@@ -1966,8 +1967,8 @@ 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->ports[i]->child)
+                        usb_disconnect(&hub->ports[i]->child);
         }
 
         /* deallocate hcd/hardware state ... nuking all pending urbs and
@@ -3131,7 +3132,7 @@ 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->ports[port1 - 1]->child;
                 if (udev && udev->can_submit) {
                         dev_warn(&intf->dev, "port %d nyet suspended\n", port1);
                         if (PMSG_IS_AUTO(msg))
@@ -4058,7 +4059,7 @@ 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->ports[port1 - 1]->child;
                 int                     delta;
 
                 if (!udev)
@@ -4122,7 +4123,7 @@ 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->ports[port1 - 1]->child;
         if ((portstatus & USB_PORT_STAT_CONNECTION) && udev &&
                         udev->state != USB_STATE_NOTATTACHED) {
                 usb_lock_device(udev);
@@ -4151,7 +4152,7 @@ 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->ports[port1 - 1]->child);
         clear_bit(port1, hub->change_bits);
 
         /* We can forget about a "removed" device when there's a physical
@@ -4287,7 +4288,7 @@ 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->ports[port1 - 1]->child = udev;
                 spin_unlock_irq(&device_state_lock);
 
                 /* Run it through the hoops (find a driver, etc) */
@@ -4295,7 +4296,7 @@ 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->ports[port1 - 1]->child = NULL;
                                 spin_unlock_irq(&device_state_lock);
                         }
                 }
@@ -4341,7 +4342,7 @@ 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->ports[port - 1]->child;
         if (!hub_is_superspeed(hdev)) {
                 if (!(portchange & USB_PORT_STAT_C_SUSPEND))
                         return 0;
@@ -4495,7 +4496,7 @@ static void hub_events(void)
                                  */
                                 if (!(portstatus & USB_PORT_STAT_ENABLE)
                                     && !connect_change
-                                    && hdev->children[i-1]) {
+                                    && hub->ports[i - 1]->child) {
                                         dev_err (hub_dev,
                                             "port %i "
                                             "disabled by hub (EMI?), "
@@ -5052,3 +5053,27 @@ void usb_queue_reset_device(struct usb_interface *iface)
         schedule_work(&iface->reset_ws);
 }
 EXPORT_SYMBOL_GPL(usb_queue_reset_device);
+
+/**
+ * usb_hub_find_child - Get the pointer of child device
+ * attached to the port which is specified by @port1.
+ * @hdev: USB device belonging to the usb hub
+ * @port1: port num to indicate which port the child device
+ *      is attached to.
+ *
+ * USB drivers call this function to get hub's child device
+ * pointer.
+ *
+ * Return NULL if input param is invalid and
+ * child's usb_device pointer if non-NULL.
+ */
+struct usb_device *usb_hub_find_child(struct usb_device *hdev,
+                int port1)
+{
+        struct usb_hub *hub = hdev_to_hub(hdev);
+
+        if (port1 < 1 || port1 > hdev->maxchild)
+                return NULL;
+        return hub->ports[port1 - 1]->child;
+}
+EXPORT_SYMBOL_GPL(usb_hub_find_child);
diff --git a/drivers/usb/host/r8a66597-hcd.c b/drivers/usb/host/r8a66597-hcd.c
index 4c634eb56358..fcc09e5ec0ad 100644
--- a/drivers/usb/host/r8a66597-hcd.c
+++ b/drivers/usb/host/r8a66597-hcd.c
@@ -2029,15 +2029,14 @@ static int r8a66597_get_frame(struct usb_hcd *hcd)
 static void collect_usb_address_map(struct usb_device *udev, unsigned long *map)
 {
         int chix;
+        struct usb_device *childdev;
 
         if (udev->state == USB_STATE_CONFIGURED &&
             udev->parent && udev->parent->devnum > 1 &&
             udev->parent->descriptor.bDeviceClass == USB_CLASS_HUB)
                 map[udev->devnum/32] |= (1 << (udev->devnum % 32));
 
-        for (chix = 0; chix < udev->maxchild; chix++) {
-                struct usb_device *childdev = udev->children[chix];
-
+        usb_hub_for_each_child(udev, chix, childdev) {
                 if (childdev)
                         collect_usb_address_map(childdev, map);
         }
diff --git a/include/linux/usb.h b/include/linux/usb.h
index 30d1ae38eab1..ff8ef2d28589 100644
--- a/include/linux/usb.h
+++ b/include/linux/usb.h
@@ -469,7 +469,6 @@ struct usb3_lpm_parameters {
  *      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
@@ -543,7 +542,6 @@ struct usb_device {
         struct list_head filelist;
 
         int maxchild;
-        struct usb_device **children;
 
         u32 quirks;
         atomic_t urbnum;
@@ -572,6 +570,19 @@ 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_hub_find_child(struct usb_device *hdev,
+        int port1);
+
+/**
+ * usb_hub_for_each_child - iterate over all child devices on the hub
+ * @hdev:  USB device belonging to the usb hub
+ * @port1: portnum associated with child device
+ * @child: child device pointer
+ */
+#define usb_hub_for_each_child(hdev, port1, child) \
+        for (port1 = 1, child = usb_hub_find_child(hdev, port1); \
+                port1 <= hdev->maxchild; \
+                child = usb_hub_find_child(hdev, ++port1))
 
 /* USB device locking */
 #define usb_lock_device(udev)           device_lock(&(udev)->dev)