net_dma: convert to dma_find_channel
Use the general-purpose channel allocation provided by dmaengine.
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h
index 41e1224..bac2c45 100644
--- a/include/linux/netdevice.h
+++ b/include/linux/netdevice.h
@@ -1113,9 +1113,6 @@
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 cbe2737..8ba8ce2 100644
--- a/include/net/netdma.h
+++ b/include/net/netdma.h
@@ -24,17 +24,6 @@
#include <linux/dmaengine.h>
#include <linux/skbuff.h>
-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 e40b0d5..bbb07db 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -4828,44 +4828,6 @@
#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
* @chan: DMA channel for the event
@@ -4894,7 +4856,6 @@
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 @@
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 75e0e0a..9b275ab 100644
--- a/net/ipv4/tcp.c
+++ b/net/ipv4/tcp.c
@@ -1317,7 +1317,7 @@
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 @@
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 99b7ecb..a6961d7 100644
--- a/net/ipv4/tcp_input.c
+++ b/net/ipv4/tcp_input.c
@@ -5005,7 +5005,7 @@
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 9d839fa..19d7b42 100644
--- a/net/ipv4/tcp_ipv4.c
+++ b/net/ipv4/tcp_ipv4.c
@@ -1594,7 +1594,7 @@
#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 e8b8337..71cd709 100644
--- a/net/ipv6/tcp_ipv6.c
+++ b/net/ipv6/tcp_ipv6.c
@@ -1640,7 +1640,7 @@
#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