netdma: adding alignment check for NETDMA ops

This is the fallout from adding memcpy alignment workaround for certain
IOATDMA hardware. NetDMA will only use DMA engine that can handle byte align
ops.

Acked-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Dave Jiang <dave.jiang@intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>

diff --git a/drivers/dma/dmaengine.c b/drivers/dma/dmaengine.c
index a6c6051ec85811041277c64d675810f14d9da851..0f1ca74fe0bb9edc21b54119dbb1b82754e9b703 100644 (file)
--- 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 679b349d9b66695f65bb3597b2a530e3e9709600..a5bb3ad5c7a5a6a89d16d529c564f6e2e3274642 100644 (file)
--- 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 22ef5f9fd2ff2e92dc4955dc9a2ac450d8a435fa..8712c5d4f91de3064a27b12999ac6b4927185fd7 100644 (file)
--- 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 b5e315f13641d683c2ab9031c0d52969c6c0873a..27c676dfea336017faf91d69028c9a10eead4296 100644 (file)
--- 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 fd54c5f8a255e81f490846e13fa827da9aaf77ac..3810b6fe0a1e801ed7820072b6776bc94a6fa0c5 100644 (file)
--- 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 3edd05ae4388741176949e9c72f3543fa8d52c87..fcb3e4f0010ee3bf25b07fdfdbd61cc68c291b8d 100644 (file)
--- 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