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>

4 files changed, 38 insertions, 10 deletions

diff --git a/drivers/infiniband/hw/mlx4/main.c b/drivers/infiniband/hw/mlx4/main.c
index 4d61e32866c6..bcf50648fa18 100644
--- a/drivers/infiniband/hw/mlx4/main.c
+++ b/drivers/infiniband/hw/mlx4/main.c
@@ -90,7 +90,8 @@ static int mlx4_ib_query_device(struct ib_device *ibdev,
         props->device_cap_flags    = IB_DEVICE_CHANGE_PHY_PORT |
                 IB_DEVICE_PORT_ACTIVE_EVENT             |
                 IB_DEVICE_SYS_IMAGE_GUID                |
-                IB_DEVICE_RC_RNR_NAK_GEN;
+                IB_DEVICE_RC_RNR_NAK_GEN                |
+                IB_DEVICE_BLOCK_MULTICAST_LOOPBACK;
         if (dev->dev->caps.flags & MLX4_DEV_CAP_FLAG_BAD_PKEY_CNTR)
                 props->device_cap_flags |= IB_DEVICE_BAD_PKEY_CNTR;
         if (dev->dev->caps.flags & MLX4_DEV_CAP_FLAG_BAD_QKEY_CNTR)
@@ -437,7 +438,9 @@ static int mlx4_ib_dealloc_pd(struct ib_pd *pd)
 static int mlx4_ib_mcg_attach(struct ib_qp *ibqp, union ib_gid *gid, u16 lid)
 {
         return mlx4_multicast_attach(to_mdev(ibqp->device)->dev,
-                                     &to_mqp(ibqp)->mqp, gid->raw);
+                                     &to_mqp(ibqp)->mqp, gid->raw,
+                                     !!(to_mqp(ibqp)->flags &
+                                        MLX4_IB_QP_BLOCK_MULTICAST_LOOPBACK));
 }
 
 static int mlx4_ib_mcg_detach(struct ib_qp *ibqp, union ib_gid *gid, u16 lid)
diff --git a/drivers/infiniband/hw/mlx4/mlx4_ib.h b/drivers/infiniband/hw/mlx4/mlx4_ib.h
index 5cf994794d25..c4cf5b69eefa 100644
--- a/drivers/infiniband/hw/mlx4/mlx4_ib.h
+++ b/drivers/infiniband/hw/mlx4/mlx4_ib.h
@@ -101,7 +101,8 @@ struct mlx4_ib_wq {
 };
 
 enum mlx4_ib_qp_flags {
-        MLX4_IB_QP_LSO          = 1 << 0
+        MLX4_IB_QP_LSO                          = 1 << 0,
+        MLX4_IB_QP_BLOCK_MULTICAST_LOOPBACK     = 1 << 1,
 };
 
 struct mlx4_ib_qp {
diff --git a/drivers/infiniband/hw/mlx4/qp.c b/drivers/infiniband/hw/mlx4/qp.c
index 44bbd6c2e315..91590e7fba0c 100644
--- a/drivers/infiniband/hw/mlx4/qp.c
+++ b/drivers/infiniband/hw/mlx4/qp.c
@@ -511,6 +511,9 @@ static int create_qp_common(struct mlx4_ib_dev *dev, struct ib_pd *pd,
         } else {
                 qp->sq_no_prefetch = 0;
 
+                if (init_attr->create_flags & IB_QP_CREATE_BLOCK_MULTICAST_LOOPBACK)
+                        qp->flags |= MLX4_IB_QP_BLOCK_MULTICAST_LOOPBACK;
+
                 if (init_attr->create_flags & IB_QP_CREATE_IPOIB_UD_LSO)
                         qp->flags |= MLX4_IB_QP_LSO;
 
@@ -684,10 +687,15 @@ struct ib_qp *mlx4_ib_create_qp(struct ib_pd *pd,
         struct mlx4_ib_qp *qp;
         int err;
 
-        /* We only support LSO, and only for kernel UD QPs. */
-        if (init_attr->create_flags & ~IB_QP_CREATE_IPOIB_UD_LSO)
+        /*
+         * We only support LSO and multicast loopback blocking, and
+         * only for kernel UD QPs.
+         */
+        if (init_attr->create_flags & ~(IB_QP_CREATE_IPOIB_UD_LSO |
+                                        IB_QP_CREATE_BLOCK_MULTICAST_LOOPBACK))
                 return ERR_PTR(-EINVAL);
-        if (init_attr->create_flags & IB_QP_CREATE_IPOIB_UD_LSO &&
+
+        if (init_attr->create_flags &&
             (pd->uobject || init_attr->qp_type != IB_QPT_UD))
                 return ERR_PTR(-EINVAL);
 
@@ -1844,6 +1852,13 @@ done:
 
         qp_init_attr->cap            = qp_attr->cap;
 
+        qp_init_attr->create_flags = 0;
+        if (qp->flags & MLX4_IB_QP_BLOCK_MULTICAST_LOOPBACK)
+                qp_init_attr->create_flags |= IB_QP_CREATE_BLOCK_MULTICAST_LOOPBACK;
+
+        if (qp->flags & MLX4_IB_QP_LSO)
+                qp_init_attr->create_flags |= IB_QP_CREATE_IPOIB_UD_LSO;
+
 out:
         mutex_unlock(&qp->mutex);
         return err;
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) {