From 1a2449a87bb7606113b1aa1a9d3c3e78ef189a1c Mon Sep 17 00:00:00 2001 From: Chris Leech Date: Tue, 23 May 2006 18:05:53 -0700 Subject: [I/OAT]: TCP recv offload to I/OAT Locks down user pages and sets up for DMA in tcp_recvmsg, then calls dma_async_try_early_copy in tcp_v4_do_rcv Signed-off-by: Chris Leech Signed-off-by: David S. Miller --- net/ipv4/tcp.c | 103 ++++++++++++++++++++++++++++++++++++++++++++++++++------- 1 file changed, 91 insertions(+), 12 deletions(-) (limited to 'net/ipv4/tcp.c') diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c index 4e067d25a63..ff6ccda9ff4 100644 --- a/net/ipv4/tcp.c +++ b/net/ipv4/tcp.c @@ -263,7 +263,7 @@ #include #include #include - +#include #include #include @@ -1110,6 +1110,7 @@ int tcp_recvmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg, int target; /* Read at least this many bytes */ long timeo; struct task_struct *user_recv = NULL; + int copied_early = 0; lock_sock(sk); @@ -1133,6 +1134,17 @@ int tcp_recvmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg, target = sock_rcvlowat(sk, flags & MSG_WAITALL, len); +#ifdef CONFIG_NET_DMA + tp->ucopy.dma_chan = NULL; + preempt_disable(); + if ((len > sysctl_tcp_dma_copybreak) && !(flags & MSG_PEEK) && + !sysctl_tcp_low_latency && __get_cpu_var(softnet_data.net_dma)) { + preempt_enable_no_resched(); + tp->ucopy.pinned_list = dma_pin_iovec_pages(msg->msg_iov, len); + } else + preempt_enable_no_resched(); +#endif + do { struct sk_buff *skb; u32 offset; @@ -1274,6 +1286,10 @@ int tcp_recvmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg, } else sk_wait_data(sk, &timeo); +#ifdef CONFIG_NET_DMA + tp->ucopy.wakeup = 0; +#endif + if (user_recv) { int chunk; @@ -1329,13 +1345,39 @@ do_prequeue: } if (!(flags & MSG_TRUNC)) { - err = skb_copy_datagram_iovec(skb, offset, - msg->msg_iov, used); - if (err) { - /* Exception. Bailout! */ - if (!copied) - copied = -EFAULT; - break; +#ifdef CONFIG_NET_DMA + if (!tp->ucopy.dma_chan && tp->ucopy.pinned_list) + tp->ucopy.dma_chan = get_softnet_dma(); + + if (tp->ucopy.dma_chan) { + tp->ucopy.dma_cookie = dma_skb_copy_datagram_iovec( + tp->ucopy.dma_chan, skb, offset, + msg->msg_iov, used, + tp->ucopy.pinned_list); + + if (tp->ucopy.dma_cookie < 0) { + + printk(KERN_ALERT "dma_cookie < 0\n"); + + /* Exception. Bailout! */ + if (!copied) + copied = -EFAULT; + break; + } + if ((offset + used) == skb->len) + copied_early = 1; + + } else +#endif + { + err = skb_copy_datagram_iovec(skb, offset, + msg->msg_iov, used); + if (err) { + /* Exception. Bailout! */ + if (!copied) + copied = -EFAULT; + break; + } } } @@ -1355,15 +1397,19 @@ skip_copy: if (skb->h.th->fin) goto found_fin_ok; - if (!(flags & MSG_PEEK)) - sk_eat_skb(sk, skb, 0); + if (!(flags & MSG_PEEK)) { + sk_eat_skb(sk, skb, copied_early); + copied_early = 0; + } continue; found_fin_ok: /* Process the FIN. */ ++*seq; - if (!(flags & MSG_PEEK)) - sk_eat_skb(sk, skb, 0); + if (!(flags & MSG_PEEK)) { + sk_eat_skb(sk, skb, copied_early); + copied_early = 0; + } break; } while (len > 0); @@ -1386,6 +1432,36 @@ skip_copy: tp->ucopy.len = 0; } +#ifdef CONFIG_NET_DMA + if (tp->ucopy.dma_chan) { + struct sk_buff *skb; + dma_cookie_t done, used; + + dma_async_memcpy_issue_pending(tp->ucopy.dma_chan); + + while (dma_async_memcpy_complete(tp->ucopy.dma_chan, + tp->ucopy.dma_cookie, &done, + &used) == DMA_IN_PROGRESS) { + /* do partial cleanup of sk_async_wait_queue */ + while ((skb = skb_peek(&sk->sk_async_wait_queue)) && + (dma_async_is_complete(skb->dma_cookie, done, + used) == DMA_SUCCESS)) { + __skb_dequeue(&sk->sk_async_wait_queue); + kfree_skb(skb); + } + } + + /* Safe to free early-copied skbs now */ + __skb_queue_purge(&sk->sk_async_wait_queue); + dma_chan_put(tp->ucopy.dma_chan); + tp->ucopy.dma_chan = NULL; + } + if (tp->ucopy.pinned_list) { + dma_unpin_iovec_pages(tp->ucopy.pinned_list); + tp->ucopy.pinned_list = NULL; + } +#endif + /* According to UNIX98, msg_name/msg_namelen are ignored * on connected socket. I was just happy when found this 8) --ANK */ @@ -1658,6 +1734,9 @@ int tcp_disconnect(struct sock *sk, int flags) __skb_queue_purge(&sk->sk_receive_queue); sk_stream_writequeue_purge(sk); __skb_queue_purge(&tp->out_of_order_queue); +#ifdef CONFIG_NET_DMA + __skb_queue_purge(&sk->sk_async_wait_queue); +#endif inet->dport = 0; -- cgit v1.2.3