IPoIB/cm: Reduce connected mode TX object size

Since IPoIB connected mode does not NETIF_F_SG, we only have one DMA
mapping per send, so we don't need a mapping[] array.  Define a new
struct with a single u64 mapping member and use it for the CM tx_ring.

Signed-off-by: Eli Cohen <eli@mellanox.co.il>
Signed-off-by: Roland Dreier <rolandd@cisco.com>

2 files changed, 12 insertions, 7 deletions

diff --git a/drivers/infiniband/ulp/ipoib/ipoib.h b/drivers/infiniband/ulp/ipoib/ipoib.h
index a89b9fbe1ef4..0281c8fecc90 100644
--- a/drivers/infiniband/ulp/ipoib/ipoib.h
+++ b/drivers/infiniband/ulp/ipoib/ipoib.h
@@ -157,6 +157,11 @@ struct ipoib_tx_buf {
         u64             mapping[MAX_SKB_FRAGS + 1];
 };
 
+struct ipoib_cm_tx_buf {
+        struct sk_buff *skb;
+        u64             mapping;
+};
+
 struct ib_cm_id;
 
 struct ipoib_cm_data {
@@ -215,7 +220,7 @@ struct ipoib_cm_tx {
         struct net_device   *dev;
         struct ipoib_neigh  *neigh;
         struct ipoib_path   *path;
-        struct ipoib_tx_buf *tx_ring;
+        struct ipoib_cm_tx_buf *tx_ring;
         unsigned             tx_head;
         unsigned             tx_tail;
         unsigned long        flags;
diff --git a/drivers/infiniband/ulp/ipoib/ipoib_cm.c b/drivers/infiniband/ulp/ipoib/ipoib_cm.c
index 87f9f3ef3b2d..0f2d3045061a 100644
--- a/drivers/infiniband/ulp/ipoib/ipoib_cm.c
+++ b/drivers/infiniband/ulp/ipoib/ipoib_cm.c
@@ -703,7 +703,7 @@ static inline int post_send(struct ipoib_dev_priv *priv,
 void ipoib_cm_send(struct net_device *dev, struct sk_buff *skb, struct ipoib_cm_tx *tx)
 {
         struct ipoib_dev_priv *priv = netdev_priv(dev);
-        struct ipoib_tx_buf *tx_req;
+        struct ipoib_cm_tx_buf *tx_req;
         u64 addr;
 
         if (unlikely(skb->len > tx->mtu)) {
@@ -734,7 +734,7 @@ void ipoib_cm_send(struct net_device *dev, struct sk_buff *skb, struct ipoib_cm_
                 return;
         }
 
-        tx_req->mapping[0] = addr;
+        tx_req->mapping = addr;
 
         if (unlikely(post_send(priv, tx, tx->tx_head & (ipoib_sendq_size - 1),
                                addr, skb->len))) {
@@ -759,7 +759,7 @@ void ipoib_cm_handle_tx_wc(struct net_device *dev, struct ib_wc *wc)
         struct ipoib_dev_priv *priv = netdev_priv(dev);
         struct ipoib_cm_tx *tx = wc->qp->qp_context;
         unsigned int wr_id = wc->wr_id & ~IPOIB_OP_CM;
-        struct ipoib_tx_buf *tx_req;
+        struct ipoib_cm_tx_buf *tx_req;
         unsigned long flags;
 
         ipoib_dbg_data(priv, "cm send completion: id %d, status: %d\n",
@@ -773,7 +773,7 @@ void ipoib_cm_handle_tx_wc(struct net_device *dev, struct ib_wc *wc)
 
         tx_req = &tx->tx_ring[wr_id];
 
-        ib_dma_unmap_single(priv->ca, tx_req->mapping[0], tx_req->skb->len, DMA_TO_DEVICE);
+        ib_dma_unmap_single(priv->ca, tx_req->mapping, tx_req->skb->len, DMA_TO_DEVICE);
 
         /* FIXME: is this right? Shouldn't we only increment on success? */
         ++dev->stats.tx_packets;
@@ -1143,7 +1143,7 @@ err_tx:
 static void ipoib_cm_tx_destroy(struct ipoib_cm_tx *p)
 {
         struct ipoib_dev_priv *priv = netdev_priv(p->dev);
-        struct ipoib_tx_buf *tx_req;
+        struct ipoib_cm_tx_buf *tx_req;
         unsigned long flags;
         unsigned long begin;
 
@@ -1171,7 +1171,7 @@ timeout:
 
         while ((int) p->tx_tail - (int) p->tx_head < 0) {
                 tx_req = &p->tx_ring[p->tx_tail & (ipoib_sendq_size - 1)];
-                ib_dma_unmap_single(priv->ca, tx_req->mapping[0], tx_req->skb->len,
+                ib_dma_unmap_single(priv->ca, tx_req->mapping, tx_req->skb->len,
                                     DMA_TO_DEVICE);
                 dev_kfree_skb_any(tx_req->skb);
                 ++p->tx_tail;