1 files changed, 113 insertions, 72 deletions

diff --git a/net/core/dev.c b/net/core/dev.c
index 4fba549caf29..ab39fe17cb58 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -115,6 +115,7 @@
 #include <net/iw_handler.h>
 #include <asm/current.h>
 #include <linux/audit.h>
+#include <linux/dmaengine.h>
 
 /*
  *      The list of packet types we will receive (as opposed to discard)
@@ -148,6 +149,12 @@ static DEFINE_SPINLOCK(ptype_lock);
 static struct list_head ptype_base[16]; /* 16 way hashed list */
 static struct list_head ptype_all;              /* Taps */
 
+#ifdef CONFIG_NET_DMA
+static struct dma_client *net_dma_client;
+static unsigned int net_dma_count;
+static spinlock_t net_dma_event_lock;
+#endif
+
 /*
  * The @dev_base list is protected by @dev_base_lock and the rtnl
  * semaphore.
@@ -1215,75 +1222,15 @@ static inline int illegal_highdma(struct net_device *dev, struct sk_buff *skb)
 #define illegal_highdma(dev, skb)       (0)
 #endif
 
-/* Keep head the same: replace data */
-int __skb_linearize(struct sk_buff *skb, gfp_t gfp_mask)
-{
-        unsigned int size;
-        u8 *data;
-        long offset;
-        struct skb_shared_info *ninfo;
-        int headerlen = skb->data - skb->head;
-        int expand = (skb->tail + skb->data_len) - skb->end;
-
-        if (skb_shared(skb))
-                BUG();
-
-        if (expand <= 0)
-                expand = 0;
-
-        size = skb->end - skb->head + expand;
-        size = SKB_DATA_ALIGN(size);
-        data = kmalloc(size + sizeof(struct skb_shared_info), gfp_mask);
-        if (!data)
-                return -ENOMEM;
-
-        /* Copy entire thing */
-        if (skb_copy_bits(skb, -headerlen, data, headerlen + skb->len))
-                BUG();
-
-        /* Set up shinfo */
-        ninfo = (struct skb_shared_info*)(data + size);
-        atomic_set(&ninfo->dataref, 1);
-        ninfo->tso_size = skb_shinfo(skb)->tso_size;
-        ninfo->tso_segs = skb_shinfo(skb)->tso_segs;
-        ninfo->nr_frags = 0;
-        ninfo->frag_list = NULL;
-
-        /* Offset between the two in bytes */
-        offset = data - skb->head;
-
-        /* Free old data. */
-        skb_release_data(skb);
-
-        skb->head = data;
-        skb->end  = data + size;
-
-        /* Set up new pointers */
-        skb->h.raw   += offset;
-        skb->nh.raw  += offset;
-        skb->mac.raw += offset;
-        skb->tail    += offset;
-        skb->data    += offset;
-
-        /* We are no longer a clone, even if we were. */
-        skb->cloned    = 0;
-
-        skb->tail     += skb->data_len;
-        skb->data_len  = 0;
-        return 0;
-}
-
 #define HARD_TX_LOCK(dev, cpu) {                        \
         if ((dev->features & NETIF_F_LLTX) == 0) {      \
-                spin_lock(&dev->xmit_lock);             \
-                dev->xmit_lock_owner = cpu;             \
+                netif_tx_lock(dev);                     \
         }                                               \
 }
 
 #define HARD_TX_UNLOCK(dev) {                           \
         if ((dev->features & NETIF_F_LLTX) == 0) {      \
-                dev->xmit_lock_owner = -1;              \
-                spin_unlock(&dev->xmit_lock);           \
+                netif_tx_unlock(dev);                   \
         }                                               \
 }
 
@@ -1321,7 +1268,7 @@ int dev_queue_xmit(struct sk_buff *skb)
 
         if (skb_shinfo(skb)->frag_list &&
             !(dev->features & NETIF_F_FRAGLIST) &&
-            __skb_linearize(skb, GFP_ATOMIC))
+            __skb_linearize(skb))
                 goto out_kfree_skb;
 
         /* Fragmented skb is linearized if device does not support SG,
@@ -1330,14 +1277,14 @@ int dev_queue_xmit(struct sk_buff *skb)
          */
         if (skb_shinfo(skb)->nr_frags &&
             (!(dev->features & NETIF_F_SG) || illegal_highdma(dev, skb)) &&
-            __skb_linearize(skb, GFP_ATOMIC))
+            __skb_linearize(skb))
                 goto out_kfree_skb;
 
         /* If packet is not checksummed and device does not support
          * checksumming for this protocol, complete checksumming here.
          */
         if (skb->ip_summed == CHECKSUM_HW &&
-            (!(dev->features & (NETIF_F_HW_CSUM | NETIF_F_NO_CSUM)) &&
+            (!(dev->features & NETIF_F_GEN_CSUM) &&
              (!(dev->features & NETIF_F_IP_CSUM) ||
               skb->protocol != htons(ETH_P_IP))))
                 if (skb_checksum_help(skb, 0))
@@ -1382,8 +1329,8 @@ int dev_queue_xmit(struct sk_buff *skb)
         /* The device has no queue. Common case for software devices:
            loopback, all the sorts of tunnels...
 
-           Really, it is unlikely that xmit_lock protection is necessary here.
-           (f.e. loopback and IP tunnels are clean ignoring statistics
+           Really, it is unlikely that netif_tx_lock protection is necessary
+           here.  (f.e. loopback and IP tunnels are clean ignoring statistics
            counters.)
            However, it is possible, that they rely on protection
            made by us here.
@@ -1846,6 +1793,19 @@ static void net_rx_action(struct softirq_action *h)
                 }
         }
 out:
+#ifdef CONFIG_NET_DMA
+        /*
+         * There may not be any more sk_buffs coming right now, so push
+         * any pending DMA copies to hardware
+         */
+        if (net_dma_client) {
+                struct dma_chan *chan;
+                rcu_read_lock();
+                list_for_each_entry_rcu(chan, &net_dma_client->channels, client_node)
+                        dma_async_memcpy_issue_pending(chan);
+                rcu_read_unlock();
+        }
+#endif
         local_irq_enable();
         return;
 
@@ -2785,7 +2745,7 @@ int register_netdevice(struct net_device *dev)
         BUG_ON(dev->reg_state != NETREG_UNINITIALIZED);
 
         spin_lock_init(&dev->queue_lock);
-        spin_lock_init(&dev->xmit_lock);
+        spin_lock_init(&dev->_xmit_lock);
         dev->xmit_lock_owner = -1;
 #ifdef CONFIG_NET_CLS_ACT
         spin_lock_init(&dev->ingress_lock);
@@ -2829,9 +2789,7 @@ int register_netdevice(struct net_device *dev)
 
         /* Fix illegal SG+CSUM combinations. */
         if ((dev->features & NETIF_F_SG) &&
-            !(dev->features & (NETIF_F_IP_CSUM |
-                               NETIF_F_NO_CSUM |
-                               NETIF_F_HW_CSUM))) {
+            !(dev->features & NETIF_F_ALL_CSUM)) {
                 printk("%s: Dropping NETIF_F_SG since no checksum feature.\n",
                        dev->name);
                 dev->features &= ~NETIF_F_SG;
@@ -3300,6 +3258,88 @@ static int dev_cpu_callback(struct notifier_block *nfb,
 }
 #endif /* CONFIG_HOTPLUG_CPU */
 
+#ifdef CONFIG_NET_DMA
+/**
+ * net_dma_rebalance -
+ * This is called when the number of channels allocated to the net_dma_client
+ * changes.  The net_dma_client tries to have one DMA channel per CPU.
+ */
+static void net_dma_rebalance(void)
+{
+        unsigned int cpu, i, n;
+        struct dma_chan *chan;
+
+        lock_cpu_hotplug();
+
+        if (net_dma_count == 0) {
+                for_each_online_cpu(cpu)
+                        rcu_assign_pointer(per_cpu(softnet_data.net_dma, cpu), NULL);
+                unlock_cpu_hotplug();
+                return;
+        }
+
+        i = 0;
+        cpu = first_cpu(cpu_online_map);
+
+        rcu_read_lock();
+        list_for_each_entry(chan, &net_dma_client->channels, client_node) {
+                n = ((num_online_cpus() / net_dma_count)
+                   + (i < (num_online_cpus() % net_dma_count) ? 1 : 0));
+
+                while(n) {
+                        per_cpu(softnet_data.net_dma, cpu) = chan;
+                        cpu = next_cpu(cpu, cpu_online_map);
+                        n--;
+                }
+                i++;
+        }
+        rcu_read_unlock();
+
+        unlock_cpu_hotplug();
+}
+
+/**
+ * netdev_dma_event - event callback for the net_dma_client
+ * @client: should always be net_dma_client
+ * @chan:
+ * @event:
+ */
+static void netdev_dma_event(struct dma_client *client, struct dma_chan *chan,
+        enum dma_event event)
+{
+        spin_lock(&net_dma_event_lock);
+        switch (event) {
+        case DMA_RESOURCE_ADDED:
+                net_dma_count++;
+                net_dma_rebalance();
+                break;
+        case DMA_RESOURCE_REMOVED:
+                net_dma_count--;
+                net_dma_rebalance();
+                break;
+        default:
+                break;
+        }
+        spin_unlock(&net_dma_event_lock);
+}
+
+/**
+ * netdev_dma_regiser - register the networking subsystem as a DMA client
+ */
+static int __init netdev_dma_register(void)
+{
+        spin_lock_init(&net_dma_event_lock);
+        net_dma_client = dma_async_client_register(netdev_dma_event);
+        if (net_dma_client == NULL)
+                return -ENOMEM;
+
+        dma_async_client_chan_request(net_dma_client, num_online_cpus());
+        return 0;
+}
+
+#else
+static int __init netdev_dma_register(void) { return -ENODEV; }
+#endif /* CONFIG_NET_DMA */
 
 /*
  *      Initialize the DEV module. At boot time this walks the device list and
@@ -3353,6 +3393,8 @@ static int __init net_dev_init(void)
                 atomic_set(&queue->backlog_dev.refcnt, 1);
         }
 
+        netdev_dma_register();
+
         dev_boot_phase = 0;
 
         open_softirq(NET_TX_SOFTIRQ, net_tx_action, NULL);
@@ -3371,7 +3413,6 @@ subsys_initcall(net_dev_init);
 EXPORT_SYMBOL(__dev_get_by_index);
 EXPORT_SYMBOL(__dev_get_by_name);
 EXPORT_SYMBOL(__dev_remove_pack);
-EXPORT_SYMBOL(__skb_linearize);
 EXPORT_SYMBOL(dev_valid_name);
 EXPORT_SYMBOL(dev_add_pack);
 EXPORT_SYMBOL(dev_alloc_name);