From nobody Mon Sep 17 00:00:00 2001 From: Chris Leech Date: Wed Mar 29 14:43:19 2006 -0800 Subject: [PATCH] [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 --- net/ipv4/tcp.c | 101 ++++++++++++++++++++++++++++++++++++++++++++------ net/ipv4/tcp_input.c | 74 +++++++++++++++++++++++++++++++++---- net/ipv4/tcp_ipv4.c | 18 ++++++++- net/ipv6/tcp_ipv6.c | 12 +++++- 4 files changed, 183 insertions(+), 22 deletions(-) bac37885ec8e35136526625b3fd432740e72b79c diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c index 2346539..8be8d69 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, stru 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 +1134,15 @@ int tcp_recvmsg(struct kiocb *iocb, stru 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)) + tp->ucopy.pinned_list = dma_pin_iovec_pages(msg->msg_iov, len); + preempt_enable_no_resched(); +#endif + do { struct sk_buff *skb; u32 offset; @@ -1274,6 +1284,10 @@ int tcp_recvmsg(struct kiocb *iocb, stru } else sk_wait_data(sk, &timeo); +#ifdef CONFIG_NET_DMA + tp->ucopy.wakeup = 0; +#endif + if (user_recv) { int chunk; @@ -1329,13 +1343,39 @@ 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 +1395,19 @@ 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 +1430,36 @@ 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 */ @@ -1653,6 +1727,9 @@ int tcp_disconnect(struct sock *sk, int __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; diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c index 195d835..c87f4eb 100644 --- a/net/ipv4/tcp_input.c +++ b/net/ipv4/tcp_input.c @@ -71,6 +71,7 @@ #include #include #include +#include int sysctl_tcp_timestamps = 1; int sysctl_tcp_window_scaling = 1; @@ -3785,6 +3786,50 @@ static inline int tcp_checksum_complete_ __tcp_checksum_complete_user(sk, skb); } +#ifdef CONFIG_NET_DMA +static int tcp_dma_try_early_copy(struct sock *sk, struct sk_buff *skb, int hlen) +{ + struct tcp_sock *tp = tcp_sk(sk); + int chunk = skb->len - hlen; + int dma_cookie; + int copied_early = 0; + + if (tp->ucopy.wakeup) + return 0; + + if (!tp->ucopy.dma_chan && tp->ucopy.pinned_list) + tp->ucopy.dma_chan = get_softnet_dma(); + + if (tp->ucopy.dma_chan && skb->ip_summed == CHECKSUM_UNNECESSARY) { + + dma_cookie = dma_skb_copy_datagram_iovec(tp->ucopy.dma_chan, + skb, hlen, tp->ucopy.iov, chunk, tp->ucopy.pinned_list); + + if (dma_cookie < 0) + goto out; + + tp->ucopy.dma_cookie = dma_cookie; + copied_early = 1; + + tp->ucopy.len -= chunk; + tp->copied_seq += chunk; + tcp_rcv_space_adjust(sk); + + if ((tp->ucopy.len == 0) || + (tcp_flag_word(skb->h.th) & TCP_FLAG_PSH) || + (atomic_read(&sk->sk_rmem_alloc) > (sk->sk_rcvbuf >> 1))) { + tp->ucopy.wakeup = 1; + sk->sk_data_ready(sk, 0); + } + } else if (chunk > 0) { + tp->ucopy.wakeup = 1; + sk->sk_data_ready(sk, 0); + } +out: + return copied_early; +} +#endif /* CONFIG_NET_DMA */ + /* * TCP receive function for the ESTABLISHED state. * @@ -3901,14 +3946,23 @@ int tcp_rcv_established(struct sock *sk, } } else { int eaten = 0; + int copied_early = 0; - if (tp->ucopy.task == current && - tp->copied_seq == tp->rcv_nxt && - len - tcp_header_len <= tp->ucopy.len && - sock_owned_by_user(sk)) { - __set_current_state(TASK_RUNNING); + if (tp->copied_seq == tp->rcv_nxt && + len - tcp_header_len <= tp->ucopy.len) { +#ifdef CONFIG_NET_DMA + if (tcp_dma_try_early_copy(sk, skb, tcp_header_len)) { + copied_early = 1; + eaten = 1; + } +#endif + if (tp->ucopy.task == current && sock_owned_by_user(sk) && !copied_early) { + __set_current_state(TASK_RUNNING); - if (!tcp_copy_to_iovec(sk, skb, tcp_header_len)) { + if (!tcp_copy_to_iovec(sk, skb, tcp_header_len)) + eaten = 1; + } + if (eaten) { /* Predicted packet is in window by definition. * seq == rcv_nxt and rcv_wup <= rcv_nxt. * Hence, check seq<=rcv_wup reduces to: @@ -3924,8 +3978,9 @@ int tcp_rcv_established(struct sock *sk, __skb_pull(skb, tcp_header_len); tp->rcv_nxt = TCP_SKB_CB(skb)->end_seq; NET_INC_STATS_BH(LINUX_MIB_TCPHPHITSTOUSER); - eaten = 1; } + if (copied_early) + tcp_cleanup_rbuf(sk, skb->len); } if (!eaten) { if (tcp_checksum_complete_user(sk, skb)) @@ -3966,6 +4021,11 @@ int tcp_rcv_established(struct sock *sk, __tcp_ack_snd_check(sk, 0); no_ack: +#ifdef CONFIG_NET_DMA + if (copied_early) + __skb_queue_tail(&sk->sk_async_wait_queue, skb); + else +#endif if (eaten) __kfree_skb(skb); else diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c index 9e85c04..5ed065f 100644 --- a/net/ipv4/tcp_ipv4.c +++ b/net/ipv4/tcp_ipv4.c @@ -71,6 +71,7 @@ #include #include #include +#include #include #include @@ -1091,8 +1092,18 @@ process: bh_lock_sock(sk); ret = 0; if (!sock_owned_by_user(sk)) { - if (!tcp_prequeue(sk, skb)) +#ifdef CONFIG_NET_DMA + struct tcp_sock *tp = tcp_sk(sk); + if (!tp->ucopy.dma_chan && tp->ucopy.pinned_list) + tp->ucopy.dma_chan = get_softnet_dma(); + if (tp->ucopy.dma_chan) ret = tcp_v4_do_rcv(sk, skb); + else +#endif + { + if (!tcp_prequeue(sk, skb)) + ret = tcp_v4_do_rcv(sk, skb); + } } else sk_add_backlog(sk, skb); bh_unlock_sock(sk); @@ -1296,6 +1307,11 @@ int tcp_v4_destroy_sock(struct sock *sk) /* Cleans up our, hopefully empty, out_of_order_queue. */ __skb_queue_purge(&tp->out_of_order_queue); +#ifdef CONFIG_NET_DMA + /* Cleans up our sk_async_wait_queue */ + __skb_queue_purge(&sk->sk_async_wait_queue); +#endif + /* Clean prequeue, it must be empty really */ __skb_queue_purge(&tp->ucopy.prequeue); diff --git a/net/ipv6/tcp_ipv6.c b/net/ipv6/tcp_ipv6.c index 301eee7..a50eb30 100644 --- a/net/ipv6/tcp_ipv6.c +++ b/net/ipv6/tcp_ipv6.c @@ -1218,8 +1218,16 @@ process: bh_lock_sock(sk); ret = 0; if (!sock_owned_by_user(sk)) { - if (!tcp_prequeue(sk, skb)) - ret = tcp_v6_do_rcv(sk, skb); +#ifdef CONFIG_NET_DMA + struct tcp_sock *tp = tcp_sk(sk); + if (tp->ucopy.dma_chan) + ret = tcp_v6_do_rcv(sk, skb); + else +#endif + { + if (!tcp_prequeue(sk, skb)) + ret = tcp_v6_do_rcv(sk, skb); + } } else sk_add_backlog(sk, skb); bh_unlock_sock(sk); -- 1.2.6