6 files changed, 20 insertions, 5 deletions

diff --git a/drivers/dma/dmaengine.c b/drivers/dma/dmaengine.c
index a6c6051ec858..0f1ca74fe0bb 100644
--- a/drivers/dma/dmaengine.c
+++ b/drivers/dma/dmaengine.c
@@ -332,6 +332,20 @@ struct dma_chan *dma_find_channel(enum dma_transaction_type tx_type)
 }
 EXPORT_SYMBOL(dma_find_channel);
 
+/*
+ * net_dma_find_channel - find a channel for net_dma
+ * net_dma has alignment requirements
+ */
+struct dma_chan *net_dma_find_channel(void)
+{
+        struct dma_chan *chan = dma_find_channel(DMA_MEMCPY);
+        if (chan && !is_dma_copy_aligned(chan->device, 1, 1, 1))
+                return NULL;
+
+        return chan;
+}
+EXPORT_SYMBOL(net_dma_find_channel);
+
 /**
  * dma_issue_pending_all - flush all pending operations across all channels
  */
diff --git a/include/linux/dmaengine.h b/include/linux/dmaengine.h
index 679b349d9b66..a5bb3ad5c7a5 100644
--- a/include/linux/dmaengine.h
+++ b/include/linux/dmaengine.h
@@ -948,6 +948,7 @@ int dma_async_device_register(struct dma_device *device);
 void dma_async_device_unregister(struct dma_device *device);
 void dma_run_dependencies(struct dma_async_tx_descriptor *tx);
 struct dma_chan *dma_find_channel(enum dma_transaction_type tx_type);
+struct dma_chan *net_dma_find_channel(void);
 #define dma_request_channel(mask, x, y) __dma_request_channel(&(mask), x, y)
 
 /* --- Helper iov-locking functions --- */
diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c
index 22ef5f9fd2ff..8712c5d4f91d 100644
--- a/net/ipv4/tcp.c
+++ b/net/ipv4/tcp.c
@@ -1450,7 +1450,7 @@ 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 &&
-                    dma_find_channel(DMA_MEMCPY)) {
+                    net_dma_find_channel()) {
                         preempt_enable_no_resched();
                         tp->ucopy.pinned_list =
                                         dma_pin_iovec_pages(msg->msg_iov, len);
@@ -1665,7 +1665,7 @@ do_prequeue:
                 if (!(flags & MSG_TRUNC)) {
 #ifdef CONFIG_NET_DMA
                         if (!tp->ucopy.dma_chan && tp->ucopy.pinned_list)
-                                tp->ucopy.dma_chan = dma_find_channel(DMA_MEMCPY);
+                                tp->ucopy.dma_chan = net_dma_find_channel();
 
                         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 b5e315f13641..27c676dfea33 100644
--- a/net/ipv4/tcp_input.c
+++ b/net/ipv4/tcp_input.c
@@ -5190,7 +5190,7 @@ 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 = dma_find_channel(DMA_MEMCPY);
+                tp->ucopy.dma_chan = net_dma_find_channel();
 
         if (tp->ucopy.dma_chan && skb_csum_unnecessary(skb)) {
 
diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c
index fd54c5f8a255..3810b6fe0a1e 100644
--- a/net/ipv4/tcp_ipv4.c
+++ b/net/ipv4/tcp_ipv4.c
@@ -1727,7 +1727,7 @@ 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 = dma_find_channel(DMA_MEMCPY);
+                        tp->ucopy.dma_chan = net_dma_find_channel();
                 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 3edd05ae4388..fcb3e4f0010e 100644
--- a/net/ipv6/tcp_ipv6.c
+++ b/net/ipv6/tcp_ipv6.c
@@ -1755,7 +1755,7 @@ 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 = dma_find_channel(DMA_MEMCPY);
+                        tp->ucopy.dma_chan = net_dma_find_channel();
                 if (tp->ucopy.dma_chan)
                         ret = tcp_v6_do_rcv(sk, skb);
                 else