diff options
Diffstat (limited to 'net/core/dev.c')
| -rw-r--r-- | net/core/dev.c | 137 |
1 files changed, 127 insertions, 10 deletions
diff --git a/net/core/dev.c b/net/core/dev.c index 195a5e9..ea24693 100644 --- a/net/core/dev.c +++ b/net/core/dev.c @@ -116,6 +116,7 @@ #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) |
