From 6f49a57aa5a0c6d4e4e27c85f7af6c83325a12d1 Mon Sep 17 00:00:00 2001 From: Dan Williams Date: Tue, 6 Jan 2009 11:38:14 -0700 Subject: dmaengine: up-level reference counting to the module level Simply, if a client wants any dmaengine channel then prevent all dmaengine modules from being removed. Once the clients are done re-enable module removal. Why?, beyond reducing complication: 1/ Tracking reference counts per-transaction in an efficient manner, as is currently done, requires a complicated scheme to avoid cache-line bouncing effects. 2/ Per-transaction ref-counting gives the false impression that a dma-driver can be gracefully removed ahead of its user (net, md, or dma-slave) 3/ None of the in-tree dma-drivers talk to hot pluggable hardware, but if such an engine were built one day we still would not need to notify clients of remove events. The driver can simply return NULL to a ->prep() request, something that is much easier for a client to handle. Reviewed-by: Andrew Morton Acked-by: Maciej Sosnowski Signed-off-by: Dan Williams --- net/ipv4/tcp.c | 1 - 1 file changed, 1 deletion(-) (limited to 'net/ipv4/tcp.c') diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c index f28acf11fc6..75e0e0a2d8d 100644 --- a/net/ipv4/tcp.c +++ b/net/ipv4/tcp.c @@ -1632,7 +1632,6 @@ skip_copy: /* 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) { -- cgit v1.2.3-70-g09d2 From f67b45999205164958de4ec0658d51fa4bee066d Mon Sep 17 00:00:00 2001 From: Dan Williams Date: Tue, 6 Jan 2009 11:38:15 -0700 Subject: net_dma: convert to dma_find_channel Use the general-purpose channel allocation provided by dmaengine. Reviewed-by: Andrew Morton Signed-off-by: Dan Williams --- include/linux/netdevice.h | 3 --- include/net/netdma.h | 11 ----------- net/core/dev.c | 40 ---------------------------------------- net/ipv4/tcp.c | 4 ++-- net/ipv4/tcp_input.c | 2 +- net/ipv4/tcp_ipv4.c | 2 +- net/ipv6/tcp_ipv6.c | 2 +- 7 files changed, 5 insertions(+), 59 deletions(-) (limited to 'net/ipv4/tcp.c') diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h index 41e1224651c..bac2c458d9b 100644 --- a/include/linux/netdevice.h +++ b/include/linux/netdevice.h @@ -1113,9 +1113,6 @@ struct softnet_data struct sk_buff *completion_queue; struct napi_struct backlog; -#ifdef CONFIG_NET_DMA - struct dma_chan *net_dma; -#endif }; DECLARE_PER_CPU(struct softnet_data,softnet_data); diff --git a/include/net/netdma.h b/include/net/netdma.h index cbe2737f4a6..8ba8ce284ee 100644 --- a/include/net/netdma.h +++ b/include/net/netdma.h @@ -24,17 +24,6 @@ #include #include -static inline struct dma_chan *get_softnet_dma(void) -{ - struct dma_chan *chan; - - rcu_read_lock(); - chan = rcu_dereference(__get_cpu_var(softnet_data).net_dma); - rcu_read_unlock(); - - return chan; -} - int dma_skb_copy_datagram_iovec(struct dma_chan* chan, struct sk_buff *skb, int offset, struct iovec *to, size_t len, struct dma_pinned_list *pinned_list); diff --git a/net/core/dev.c b/net/core/dev.c index e40b0d57f8f..bbb07dbe174 100644 --- a/net/core/dev.c +++ b/net/core/dev.c @@ -4827,44 +4827,6 @@ static int dev_cpu_callback(struct notifier_block *nfb, } #ifdef CONFIG_NET_DMA -/** - * net_dma_rebalance - try to maintain one DMA channel per CPU - * @net_dma: DMA client and associated data (lock, channels, channel_mask) - * - * 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(struct net_dma *net_dma) -{ - unsigned int cpu, i, n, chan_idx; - struct dma_chan *chan; - - if (cpus_empty(net_dma->channel_mask)) { - for_each_online_cpu(cpu) - rcu_assign_pointer(per_cpu(softnet_data, cpu).net_dma, NULL); - return; - } - - i = 0; - cpu = first_cpu(cpu_online_map); - - for_each_cpu_mask_nr(chan_idx, net_dma->channel_mask) { - chan = net_dma->channels[chan_idx]; - - n = ((num_online_cpus() / cpus_weight(net_dma->channel_mask)) - + (i < (num_online_cpus() % - cpus_weight(net_dma->channel_mask)) ? 1 : 0)); - - while(n) { - per_cpu(softnet_data, cpu).net_dma = chan; - cpu = next_cpu(cpu, cpu_online_map); - n--; - } - i++; - } -} - /** * netdev_dma_event - event callback for the net_dma_client * @client: should always be net_dma_client @@ -4894,7 +4856,6 @@ netdev_dma_event(struct dma_client *client, struct dma_chan *chan, ack = DMA_ACK; net_dma->channels[pos] = chan; cpu_set(pos, net_dma->channel_mask); - net_dma_rebalance(net_dma); } break; case DMA_RESOURCE_REMOVED: @@ -4909,7 +4870,6 @@ netdev_dma_event(struct dma_client *client, struct dma_chan *chan, ack = DMA_ACK; cpu_clear(pos, net_dma->channel_mask); net_dma->channels[i] = NULL; - net_dma_rebalance(net_dma); } break; default: diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c index 75e0e0a2d8d..9b275abc8eb 100644 --- a/net/ipv4/tcp.c +++ b/net/ipv4/tcp.c @@ -1317,7 +1317,7 @@ int tcp_recvmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg, if ((available < target) && (len > sysctl_tcp_dma_copybreak) && !(flags & MSG_PEEK) && !sysctl_tcp_low_latency && - __get_cpu_var(softnet_data).net_dma) { + dma_find_channel(DMA_MEMCPY)) { preempt_enable_no_resched(); tp->ucopy.pinned_list = dma_pin_iovec_pages(msg->msg_iov, len); @@ -1527,7 +1527,7 @@ do_prequeue: if (!(flags & MSG_TRUNC)) { #ifdef CONFIG_NET_DMA if (!tp->ucopy.dma_chan && tp->ucopy.pinned_list) - tp->ucopy.dma_chan = get_softnet_dma(); + tp->ucopy.dma_chan = dma_find_channel(DMA_MEMCPY); if (tp->ucopy.dma_chan) { tp->ucopy.dma_cookie = dma_skb_copy_datagram_iovec( diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c index 99b7ecbe889..a6961d75c7e 100644 --- a/net/ipv4/tcp_input.c +++ b/net/ipv4/tcp_input.c @@ -5005,7 +5005,7 @@ static int tcp_dma_try_early_copy(struct sock *sk, struct sk_buff *skb, return 0; if (!tp->ucopy.dma_chan && tp->ucopy.pinned_list) - tp->ucopy.dma_chan = get_softnet_dma(); + tp->ucopy.dma_chan = dma_find_channel(DMA_MEMCPY); if (tp->ucopy.dma_chan && skb_csum_unnecessary(skb)) { diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c index 9d839fa9331..19d7b429a26 100644 --- a/net/ipv4/tcp_ipv4.c +++ b/net/ipv4/tcp_ipv4.c @@ -1594,7 +1594,7 @@ process: #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(); + tp->ucopy.dma_chan = dma_find_channel(DMA_MEMCPY); if (tp->ucopy.dma_chan) ret = tcp_v4_do_rcv(sk, skb); else diff --git a/net/ipv6/tcp_ipv6.c b/net/ipv6/tcp_ipv6.c index e8b8337a831..71cd70951d7 100644 --- a/net/ipv6/tcp_ipv6.c +++ b/net/ipv6/tcp_ipv6.c @@ -1640,7 +1640,7 @@ process: #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(); + tp->ucopy.dma_chan = dma_find_channel(DMA_MEMCPY); if (tp->ucopy.dma_chan) ret = tcp_v6_do_rcv(sk, skb); else -- cgit v1.2.3-70-g09d2 From 684f2176015b313ab59cecf574117969cf638f28 Mon Sep 17 00:00:00 2001 From: Herbert Xu Date: Thu, 8 Jan 2009 10:41:23 -0800 Subject: tcp6: Add GRO support This patch adds GRO support for TCP over IPv6. The code is exactly the same as the IPv4 version except for the pseudo-header checksum computation. Note that I've removed the unused tcphdr argument from tcp_v6_check rather than invent a bogus value for GRO. Signed-off-by: Herbert Xu Signed-off-by: David S. Miller --- net/ipv4/tcp.c | 2 ++ net/ipv6/tcp_ipv6.c | 45 +++++++++++++++++++++++++++++++++++++++++---- 2 files changed, 43 insertions(+), 4 deletions(-) (limited to 'net/ipv4/tcp.c') diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c index 35bcddf8a93..bd6ff907d9e 100644 --- a/net/ipv4/tcp.c +++ b/net/ipv4/tcp.c @@ -2542,6 +2542,7 @@ out: return pp; } +EXPORT_SYMBOL(tcp_gro_receive); int tcp_gro_complete(struct sk_buff *skb) { @@ -2558,6 +2559,7 @@ int tcp_gro_complete(struct sk_buff *skb) return 0; } +EXPORT_SYMBOL(tcp_gro_complete); #ifdef CONFIG_TCP_MD5SIG static unsigned long tcp_md5sig_users; diff --git a/net/ipv6/tcp_ipv6.c b/net/ipv6/tcp_ipv6.c index e8b8337a831..1297306d729 100644 --- a/net/ipv6/tcp_ipv6.c +++ b/net/ipv6/tcp_ipv6.c @@ -101,7 +101,7 @@ static void tcp_v6_hash(struct sock *sk) } } -static __inline__ __sum16 tcp_v6_check(struct tcphdr *th, int len, +static __inline__ __sum16 tcp_v6_check(int len, struct in6_addr *saddr, struct in6_addr *daddr, __wsum base) @@ -501,7 +501,7 @@ static int tcp_v6_send_synack(struct sock *sk, struct request_sock *req) if (skb) { struct tcphdr *th = tcp_hdr(skb); - th->check = tcp_v6_check(th, skb->len, + th->check = tcp_v6_check(skb->len, &treq->loc_addr, &treq->rmt_addr, csum_partial(th, skb->len, skb->csum)); @@ -942,6 +942,41 @@ static int tcp_v6_gso_send_check(struct sk_buff *skb) return 0; } +struct sk_buff **tcp6_gro_receive(struct sk_buff **head, struct sk_buff *skb) +{ + struct ipv6hdr *iph = ipv6_hdr(skb); + + switch (skb->ip_summed) { + case CHECKSUM_COMPLETE: + if (!tcp_v6_check(skb->len, &iph->saddr, &iph->daddr, + skb->csum)) { + skb->ip_summed = CHECKSUM_UNNECESSARY; + break; + } + + /* fall through */ + case CHECKSUM_NONE: + NAPI_GRO_CB(skb)->flush = 1; + return NULL; + } + + return tcp_gro_receive(head, skb); +} +EXPORT_SYMBOL(tcp6_gro_receive); + +int tcp6_gro_complete(struct sk_buff *skb) +{ + struct ipv6hdr *iph = ipv6_hdr(skb); + struct tcphdr *th = tcp_hdr(skb); + + th->check = ~tcp_v6_check(skb->len - skb_transport_offset(skb), + &iph->saddr, &iph->daddr, 0); + skb_shinfo(skb)->gso_type = SKB_GSO_TCPV6; + + return tcp_gro_complete(skb); +} +EXPORT_SYMBOL(tcp6_gro_complete); + static void tcp_v6_send_response(struct sk_buff *skb, u32 seq, u32 ack, u32 win, u32 ts, struct tcp_md5sig_key *key, int rst) { @@ -1429,14 +1464,14 @@ out: static __sum16 tcp_v6_checksum_init(struct sk_buff *skb) { if (skb->ip_summed == CHECKSUM_COMPLETE) { - if (!tcp_v6_check(tcp_hdr(skb), skb->len, &ipv6_hdr(skb)->saddr, + if (!tcp_v6_check(skb->len, &ipv6_hdr(skb)->saddr, &ipv6_hdr(skb)->daddr, skb->csum)) { skb->ip_summed = CHECKSUM_UNNECESSARY; return 0; } } - skb->csum = ~csum_unfold(tcp_v6_check(tcp_hdr(skb), skb->len, + skb->csum = ~csum_unfold(tcp_v6_check(skb->len, &ipv6_hdr(skb)->saddr, &ipv6_hdr(skb)->daddr, 0)); @@ -2062,6 +2097,8 @@ static struct inet6_protocol tcpv6_protocol = { .err_handler = tcp_v6_err, .gso_send_check = tcp_v6_gso_send_check, .gso_segment = tcp_tso_segment, + .gro_receive = tcp6_gro_receive, + .gro_complete = tcp6_gro_complete, .flags = INET6_PROTO_NOPOLICY|INET6_PROTO_FINAL, }; -- cgit v1.2.3-70-g09d2