usb: gadget: prevent change of Host MAC address of 'usb0' interface
[firefly-linux-kernel-4.4.55.git] / drivers / usb / gadget / u_ether.c
index 4b76124ce96b8dfaeab5ab0f0a89bf4f5abf15a6..6a5065966494a5d068e0a5d5a860dffae31c092a 100644 (file)
@@ -48,6 +48,8 @@
 
 #define UETH__VERSION  "29-May-2008"
 
+static struct workqueue_struct *uether_wq;
+
 struct eth_dev {
        /* lock is held while accessing port_usb
         */
@@ -64,12 +66,14 @@ struct eth_dev {
        struct sk_buff_head     rx_frames;
 
        unsigned                header_len;
+       unsigned                ul_max_pkts_per_xfer;
        struct sk_buff          *(*wrap)(struct gether *, struct sk_buff *skb);
        int                     (*unwrap)(struct gether *,
                                                struct sk_buff *skb,
                                                struct sk_buff_head *list);
 
        struct work_struct      work;
+       struct work_struct      rx_work;
 
        unsigned long           todo;
 #define        WORK_RX_MEMORY          0
@@ -226,9 +230,13 @@ rx_submit(struct eth_dev *dev, struct usb_request *req, gfp_t gfp_flags)
        size += out->maxpacket - 1;
        size -= size % out->maxpacket;
 
+       if (dev->ul_max_pkts_per_xfer)
+               size *= dev->ul_max_pkts_per_xfer;
+
        if (dev->port_usb->is_fixed)
                size = max_t(size_t, size, dev->port_usb->fixed_out_len);
 
+       DBG(dev, "%s: size: %d\n", __func__, size);
        skb = alloc_skb(size + NET_IP_ALIGN, gfp_flags);
        if (skb == NULL) {
                DBG(dev, "no rx skb\n");
@@ -254,18 +262,16 @@ enomem:
                DBG(dev, "rx submit --> %d\n", retval);
                if (skb)
                        dev_kfree_skb_any(skb);
-               spin_lock_irqsave(&dev->req_lock, flags);
-               list_add(&req->list, &dev->rx_reqs);
-               spin_unlock_irqrestore(&dev->req_lock, flags);
        }
        return retval;
 }
 
 static void rx_complete(struct usb_ep *ep, struct usb_request *req)
 {
-       struct sk_buff  *skb = req->context, *skb2;
+       struct sk_buff  *skb = req->context;
        struct eth_dev  *dev = ep->driver_data;
        int             status = req->status;
+       bool            queue = 0;
 
        switch (status) {
 
@@ -289,30 +295,9 @@ static void rx_complete(struct usb_ep *ep, struct usb_request *req)
                } else {
                        skb_queue_tail(&dev->rx_frames, skb);
                }
-               skb = NULL;
-
-               skb2 = skb_dequeue(&dev->rx_frames);
-               while (skb2) {
-                       if (status < 0
-                                       || ETH_HLEN > skb2->len
-                                       || skb2->len > VLAN_ETH_FRAME_LEN) {
-                               dev->net->stats.rx_errors++;
-                               dev->net->stats.rx_length_errors++;
-                               DBG(dev, "rx length %d\n", skb2->len);
-                               dev_kfree_skb_any(skb2);
-                               goto next_frame;
-                       }
-                       skb2->protocol = eth_type_trans(skb2, dev->net);
-                       dev->net->stats.rx_packets++;
-                       dev->net->stats.rx_bytes += skb2->len;
 
-                       /* no buffer copies needed, unless hardware can't
-                        * use skb buffers.
-                        */
-                       status = netif_rx(skb2);
-next_frame:
-                       skb2 = skb_dequeue(&dev->rx_frames);
-               }
+               if (!status)
+                       queue = 1;
                break;
 
        /* software-driven interface shutdown */
@@ -335,22 +320,20 @@ quiesce:
                /* FALLTHROUGH */
 
        default:
+               queue = 1;
+               dev_kfree_skb_any(skb);
                dev->net->stats.rx_errors++;
                DBG(dev, "rx status %d\n", status);
                break;
        }
 
-       if (skb)
-               dev_kfree_skb_any(skb);
-       if (!netif_running(dev->net)) {
 clean:
-               spin_lock(&dev->req_lock);
-               list_add(&req->list, &dev->rx_reqs);
-               spin_unlock(&dev->req_lock);
-               req = NULL;
-       }
-       if (req)
-               rx_submit(dev, req, GFP_ATOMIC);
+       spin_lock(&dev->req_lock);
+       list_add(&req->list, &dev->rx_reqs);
+       spin_unlock(&dev->req_lock);
+
+       if (queue)
+               queue_work(uether_wq, &dev->rx_work);
 }
 
 static int prealloc(struct list_head *list, struct usb_ep *ep, unsigned n)
@@ -415,16 +398,24 @@ static void rx_fill(struct eth_dev *dev, gfp_t gfp_flags)
 {
        struct usb_request      *req;
        unsigned long           flags;
+       int                     req_cnt = 0;
 
        /* fill unused rxq slots with some skb */
        spin_lock_irqsave(&dev->req_lock, flags);
        while (!list_empty(&dev->rx_reqs)) {
+               /* break the nexus of continuous completion and re-submission*/
+               if (++req_cnt > qlen(dev->gadget))
+                       break;
+
                req = container_of(dev->rx_reqs.next,
                                struct usb_request, list);
                list_del_init(&req->list);
                spin_unlock_irqrestore(&dev->req_lock, flags);
 
                if (rx_submit(dev, req, gfp_flags) < 0) {
+                       spin_lock_irqsave(&dev->req_lock, flags);
+                       list_add(&req->list, &dev->rx_reqs);
+                       spin_unlock_irqrestore(&dev->req_lock, flags);
                        defer_kevent(dev, WORK_RX_MEMORY);
                        return;
                }
@@ -434,6 +425,36 @@ static void rx_fill(struct eth_dev *dev, gfp_t gfp_flags)
        spin_unlock_irqrestore(&dev->req_lock, flags);
 }
 
+static void process_rx_w(struct work_struct *work)
+{
+       struct eth_dev  *dev = container_of(work, struct eth_dev, rx_work);
+       struct sk_buff  *skb;
+       int             status = 0;
+
+       if (!dev->port_usb)
+               return;
+
+       while ((skb = skb_dequeue(&dev->rx_frames))) {
+               if (status < 0
+                               || ETH_HLEN > skb->len
+                               || skb->len > ETH_FRAME_LEN) {
+                       dev->net->stats.rx_errors++;
+                       dev->net->stats.rx_length_errors++;
+                       DBG(dev, "rx length %d\n", skb->len);
+                       dev_kfree_skb_any(skb);
+                       continue;
+               }
+               skb->protocol = eth_type_trans(skb, dev->net);
+               dev->net->stats.rx_packets++;
+               dev->net->stats.rx_bytes += skb->len;
+
+               status = netif_rx_ni(skb);
+       }
+
+       if (netif_running(dev->net))
+               rx_fill(dev, GFP_KERNEL);
+}
+
 static void eth_work(struct work_struct *work)
 {
        struct eth_dev  *dev = container_of(work, struct eth_dev, work);
@@ -697,6 +718,8 @@ static int eth_stop(struct net_device *net)
 
 /*-------------------------------------------------------------------------*/
 
+static u8 host_ethaddr[ETH_ALEN];
+
 /* initial value, changed by "ifconfig usb0 hw ether xx:xx:xx:xx:xx:xx" */
 static char *dev_addr;
 module_param(dev_addr, charp, S_IRUGO);
@@ -728,6 +751,17 @@ static int get_ether_addr(const char *str, u8 *dev_addr)
        return 1;
 }
 
+static int get_host_ether_addr(u8 *str, u8 *dev_addr)
+{
+       memcpy(dev_addr, str, ETH_ALEN);
+       if (is_valid_ether_addr(dev_addr))
+               return 0;
+
+       random_ether_addr(dev_addr);
+       memcpy(str, dev_addr, ETH_ALEN);
+       return 1;
+}
+
 static const struct net_device_ops eth_netdev_ops = {
        .ndo_open               = eth_open,
        .ndo_stop               = eth_stop,
@@ -770,6 +804,7 @@ struct eth_dev *gether_setup_name(struct usb_gadget *g, u8 ethaddr[ETH_ALEN],
        spin_lock_init(&dev->lock);
        spin_lock_init(&dev->req_lock);
        INIT_WORK(&dev->work, eth_work);
+       INIT_WORK(&dev->rx_work, process_rx_w);
        INIT_LIST_HEAD(&dev->tx_reqs);
        INIT_LIST_HEAD(&dev->rx_reqs);
 
@@ -782,9 +817,11 @@ struct eth_dev *gether_setup_name(struct usb_gadget *g, u8 ethaddr[ETH_ALEN],
        if (get_ether_addr(dev_addr, net->dev_addr))
                dev_warn(&g->dev,
                        "using random %s ethernet address\n", "self");
-       if (get_ether_addr(host_addr, dev->host_mac))
-               dev_warn(&g->dev,
-                       "using random %s ethernet address\n", "host");
+
+       if (get_host_ether_addr(host_ethaddr, dev->host_mac))
+               dev_warn(&g->dev, "using random %s ethernet address\n", "host");
+       else
+               dev_warn(&g->dev, "using previous %s ethernet address\n", "host");
 
        if (ethaddr)
                memcpy(ethaddr, dev->host_mac, ETH_ALEN);
@@ -882,6 +919,7 @@ struct net_device *gether_connect(struct gether *link)
                dev->header_len = link->header_len;
                dev->unwrap = link->unwrap;
                dev->wrap = link->wrap;
+               dev->ul_max_pkts_per_xfer = link->ul_max_pkts_per_xfer;
 
                spin_lock(&dev->lock);
                dev->port_usb = link;
@@ -927,6 +965,7 @@ void gether_disconnect(struct gether *link)
 {
        struct eth_dev          *dev = link->ioport;
        struct usb_request      *req;
+       struct sk_buff          *skb;
 
        WARN_ON(!dev);
        if (!dev)
@@ -968,6 +1007,12 @@ void gether_disconnect(struct gether *link)
                spin_lock(&dev->req_lock);
        }
        spin_unlock(&dev->req_lock);
+
+       spin_lock(&dev->rx_frames.lock);
+       while ((skb = __skb_dequeue(&dev->rx_frames)))
+               dev_kfree_skb_any(skb);
+       spin_unlock(&dev->rx_frames.lock);
+
        link->out_ep->driver_data = NULL;
        link->out_ep->desc = NULL;
 
@@ -980,3 +1025,23 @@ void gether_disconnect(struct gether *link)
        dev->port_usb = NULL;
        spin_unlock(&dev->lock);
 }
+
+static int __init gether_init(void)
+{
+       uether_wq  = create_singlethread_workqueue("uether");
+       if (!uether_wq) {
+               pr_err("%s: Unable to create workqueue: uether\n", __func__);
+               return -ENOMEM;
+       }
+       return 0;
+}
+module_init(gether_init);
+
+static void __exit gether_exit(void)
+{
+       destroy_workqueue(uether_wq);
+
+}
+module_exit(gether_exit);
+MODULE_DESCRIPTION("ethernet over USB driver");
+MODULE_LICENSE("GPL v2");