Merge master.kernel.org:/pub/scm/linux/kernel/git/davem/net-2.6
[linux-2.6-microblaze.git] / net / core / dev.c
index 195a5e9..ea24693 100644 (file)
 #include <asm/current.h>
 #include <linux/audit.h>
 #include <linux/dmaengine.h>
+#include <linux/err.h>
 
 /*
  *     The list of packet types we will receive (as opposed to discard)
@@ -1048,7 +1049,7 @@ static inline void net_timestamp(struct sk_buff *skb)
  *     taps currently in use.
  */
 
-void dev_queue_xmit_nit(struct sk_buff *skb, struct net_device *dev)
+static void dev_queue_xmit_nit(struct sk_buff *skb, struct net_device *dev)
 {
        struct packet_type *ptype;
 
@@ -1186,6 +1187,40 @@ out:
        return ret;
 }
 
+/**
+ *     skb_gso_segment - Perform segmentation on skb.
+ *     @skb: buffer to segment
+ *     @sg: whether scatter-gather is supported on the target.
+ *
+ *     This function segments the given skb and returns a list of segments.
+ */
+struct sk_buff *skb_gso_segment(struct sk_buff *skb, int sg)
+{
+       struct sk_buff *segs = ERR_PTR(-EPROTONOSUPPORT);
+       struct packet_type *ptype;
+       int type = skb->protocol;
+
+       BUG_ON(skb_shinfo(skb)->frag_list);
+       BUG_ON(skb->ip_summed != CHECKSUM_HW);
+
+       skb->mac.raw = skb->data;
+       skb->mac_len = skb->nh.raw - skb->data;
+       __skb_pull(skb, skb->mac_len);
+
+       rcu_read_lock();
+       list_for_each_entry_rcu(ptype, &ptype_base[ntohs(type) & 15], list) {
+               if (ptype->type == type && !ptype->dev && ptype->gso_segment) {
+                       segs = ptype->gso_segment(skb, sg);
+                       break;
+               }
+       }
+       rcu_read_unlock();
+
+       return segs;
+}
+
+EXPORT_SYMBOL(skb_gso_segment);
+
 /* Take action when hardware reception checksum errors are detected. */
 #ifdef CONFIG_BUG
 void netdev_rx_csum_fault(struct net_device *dev)
@@ -1222,6 +1257,86 @@ static inline int illegal_highdma(struct net_device *dev, struct sk_buff *skb)
 #define illegal_highdma(dev, skb)      (0)
 #endif
 
+struct dev_gso_cb {
+       void (*destructor)(struct sk_buff *skb);
+};
+
+#define DEV_GSO_CB(skb) ((struct dev_gso_cb *)(skb)->cb)
+
+static void dev_gso_skb_destructor(struct sk_buff *skb)
+{
+       struct dev_gso_cb *cb;
+
+       do {
+               struct sk_buff *nskb = skb->next;
+
+               skb->next = nskb->next;
+               nskb->next = NULL;
+               kfree_skb(nskb);
+       } while (skb->next);
+
+       cb = DEV_GSO_CB(skb);
+       if (cb->destructor)
+               cb->destructor(skb);
+}
+
+/**
+ *     dev_gso_segment - Perform emulated hardware segmentation on skb.
+ *     @skb: buffer to segment
+ *
+ *     This function segments the given skb and stores the list of segments
+ *     in skb->next.
+ */
+static int dev_gso_segment(struct sk_buff *skb)
+{
+       struct net_device *dev = skb->dev;
+       struct sk_buff *segs;
+
+       segs = skb_gso_segment(skb, dev->features & NETIF_F_SG &&
+                                   !illegal_highdma(dev, skb));
+       if (unlikely(IS_ERR(segs)))
+               return PTR_ERR(segs);
+
+       skb->next = segs;
+       DEV_GSO_CB(skb)->destructor = skb->destructor;
+       skb->destructor = dev_gso_skb_destructor;
+
+       return 0;
+}
+
+int dev_hard_start_xmit(struct sk_buff *skb, struct net_device *dev)
+{
+       if (likely(!skb->next)) {
+               if (netdev_nit)
+                       dev_queue_xmit_nit(skb, dev);
+
+               if (!netif_needs_gso(dev, skb))
+                       return dev->hard_start_xmit(skb, dev);
+
+               if (unlikely(dev_gso_segment(skb)))
+                       goto out_kfree_skb;
+       }
+
+       do {
+               struct sk_buff *nskb = skb->next;
+               int rc;
+
+               skb->next = nskb->next;
+               nskb->next = NULL;
+               rc = dev->hard_start_xmit(nskb, dev);
+               if (unlikely(rc)) {
+                       skb->next = nskb;
+                       return rc;
+               }
+       } while (skb->next);
+       
+       skb->destructor = DEV_GSO_CB(skb)->destructor;
+
+out_kfree_skb:
+       kfree_skb(skb);
+       return 0;
+}
+
 #define HARD_TX_LOCK(dev, cpu) {                       \
        if ((dev->features & NETIF_F_LLTX) == 0) {      \
                netif_tx_lock(dev);                     \
@@ -1266,6 +1381,10 @@ int dev_queue_xmit(struct sk_buff *skb)
        struct Qdisc *q;
        int rc = -ENOMEM;
 
+       /* GSO will handle the following emulations directly. */
+       if (netif_needs_gso(dev, skb))
+               goto gso;
+
        if (skb_shinfo(skb)->frag_list &&
            !(dev->features & NETIF_F_FRAGLIST) &&
            __skb_linearize(skb))
@@ -1290,12 +1409,13 @@ int dev_queue_xmit(struct sk_buff *skb)
                if (skb_checksum_help(skb, 0))
                        goto out_kfree_skb;
 
+gso:
        spin_lock_prefetch(&dev->queue_lock);
 
        /* Disable soft irqs for various locks below. Also 
         * stops preemption for RCU. 
         */
-       local_bh_disable(); 
+       rcu_read_lock_bh(); 
 
        /* Updates of qdisc are serialized by queue_lock. 
         * The struct Qdisc which is pointed to by qdisc is now a 
@@ -1346,11 +1466,8 @@ int dev_queue_xmit(struct sk_buff *skb)
                        HARD_TX_LOCK(dev, cpu);
 
                        if (!netif_queue_stopped(dev)) {
-                               if (netdev_nit)
-                                       dev_queue_xmit_nit(skb, dev);
-
                                rc = 0;
-                               if (!dev->hard_start_xmit(skb, dev)) {
+                               if (!dev_hard_start_xmit(skb, dev)) {
                                        HARD_TX_UNLOCK(dev);
                                        goto out;
                                }
@@ -1369,13 +1486,13 @@ int dev_queue_xmit(struct sk_buff *skb)
        }
 
        rc = -ENETDOWN;
-       local_bh_enable();
+       rcu_read_unlock_bh();
 
 out_kfree_skb:
        kfree_skb(skb);
        return rc;
 out:
-       local_bh_enable();
+       rcu_read_unlock_bh();
        return rc;
 }
 
@@ -3301,8 +3418,8 @@ static void net_dma_rebalance(void)
 /**
  * netdev_dma_event - event callback for the net_dma_client
  * @client: should always be net_dma_client
- * @chan:
- * @event:
+ * @chan: DMA channel for the event
+ * @event: event type
  */
 static void netdev_dma_event(struct dma_client *client, struct dma_chan *chan,
        enum dma_event event)