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[I/OAT]: TCP recv offload to I/OAT

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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 <christopher.leech@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Chris Leech 2006-05-23 18:05:53 -07:00 • committed by David S. Miller
parent 9593782585
commit 1a2449a87b
4 changed files with 185 additions and 22 deletions
Download patch file Download diff file Expand all files Collapse all files

74
net/ipv4/tcp_input.c
View file

@ -71,6 +71,7 @@
#include <net/inet_common.h>
#include <linux/ipsec.h>
#include <asm/unaligned.h>
#include <net/netdma.h>
int sysctl_tcp_timestamps = 1;
int sysctl_tcp_window_scaling = 1;
@ -3785,6 +3786,50 @@ static inline int tcp_checksum_complete_user(struct sock *sk, struct sk_buff *sk
__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, struct sk_buff *skb,
}
} 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, struct sk_buff *skb,
__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, struct sk_buff *skb,
__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