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Diffstat (limited to 'net/core/dev.c')
-rw-r--r--net/core/dev.c185
1 files changed, 113 insertions, 72 deletions
diff --git a/net/core/dev.c b/net/core/dev.c
index 4fba549caf2..ab39fe17cb5 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);