IB/mlx4: Add support for blocking multicast loopback packets

Add support for handling the IB_QP_CREATE_MULTICAST_BLOCK_LOOPBACK
flag by using the per-multicast group loopback blocking feature of
mlx4 hardware.

Signed-off-by: Ron Livne <ronli@voltaire.com>
Signed-off-by: Roland Dreier <rolandd@cisco.com>

1 files changed, 13 insertions, 4 deletions

diff --git a/drivers/net/mlx4/mcg.c b/drivers/net/mlx4/mcg.c
index 57f7f1f0d4ec..b4b57870ddfd 100644
--- a/drivers/net/mlx4/mcg.c
+++ b/drivers/net/mlx4/mcg.c
@@ -38,6 +38,9 @@
 
 #include "mlx4.h"
 
+#define MGM_QPN_MASK       0x00FFFFFF
+#define MGM_BLCK_LB_BIT    30
+
 struct mlx4_mgm {
         __be32                  next_gid_index;
         __be32                  members_count;
@@ -153,7 +156,8 @@ static int find_mgm(struct mlx4_dev *dev,
         return err;
 }
 
-int mlx4_multicast_attach(struct mlx4_dev *dev, struct mlx4_qp *qp, u8 gid[16])
+int mlx4_multicast_attach(struct mlx4_dev *dev, struct mlx4_qp *qp, u8 gid[16],
+                          int block_mcast_loopback)
 {
         struct mlx4_priv *priv = mlx4_priv(dev);
         struct mlx4_cmd_mailbox *mailbox;
@@ -202,13 +206,18 @@ int mlx4_multicast_attach(struct mlx4_dev *dev, struct mlx4_qp *qp, u8 gid[16])
         }
 
         for (i = 0; i < members_count; ++i)
-                if (mgm->qp[i] == cpu_to_be32(qp->qpn)) {
+                if ((be32_to_cpu(mgm->qp[i]) & MGM_QPN_MASK) == qp->qpn) {
                         mlx4_dbg(dev, "QP %06x already a member of MGM\n", qp->qpn);
                         err = 0;
                         goto out;
                 }
 
-        mgm->qp[members_count++] = cpu_to_be32(qp->qpn);
+        if (block_mcast_loopback)
+                mgm->qp[members_count++] = cpu_to_be32((qp->qpn & MGM_QPN_MASK) |
+                                                       (1 << MGM_BLCK_LB_BIT));
+        else
+                mgm->qp[members_count++] = cpu_to_be32(qp->qpn & MGM_QPN_MASK);
+
         mgm->members_count       = cpu_to_be32(members_count);
 
         err = mlx4_WRITE_MCG(dev, index, mailbox);
@@ -283,7 +292,7 @@ int mlx4_multicast_detach(struct mlx4_dev *dev, struct mlx4_qp *qp, u8 gid[16])
 
         members_count = be32_to_cpu(mgm->members_count);
         for (loc = -1, i = 0; i < members_count; ++i)
-                if (mgm->qp[i] == cpu_to_be32(qp->qpn))
+                if ((be32_to_cpu(mgm->qp[i]) & MGM_QPN_MASK) == qp->qpn)
                         loc = i;
 
         if (loc == -1) {