RDMA/cma: Remove dead code for kernel rdmacm multicast

There is no kernel user of RDMA CM multicast so this code managing the
multicast subscription of the kernel-only internal QP is dead. Remove it.

This makes the bug fixes in the next patches much simpler.

Link: https://lore.kernel.org/r/20200902081122.745412-7-leon@kernel.org
Signed-off-by: Leon Romanovsky <leonro@nvidia.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>

diff --git a/drivers/infiniband/core/cma.c b/drivers/infiniband/core/cma.c
index df0a5bc..79d14fb 100644 (file)
--- a/drivers/infiniband/core/cma.c
+++ b/drivers/infiniband/core/cma.c
@@ -4337,16 +4337,6 @@ static int cma_ib_mc_handler(int status, struct ib_sa_multicast *multicast)
        else
                pr_debug_ratelimited("RDMA CM: MULTICAST_ERROR: failed to join multicast. status %d\n",
                                     status);
-       mutex_lock(&id_priv->qp_mutex);
-       if (!status && id_priv->id.qp) {
-               status = ib_attach_mcast(id_priv->id.qp, &multicast->rec.mgid,
-                                        be16_to_cpu(multicast->rec.mlid));
-               if (status)
-                       pr_debug_ratelimited("RDMA CM: MULTICAST_ERROR: failed to attach QP. status %d\n",
-                                            status);
-       }
-       mutex_unlock(&id_priv->qp_mutex);
-
        event.status = status;
        event.param.ud.private_data = mc->context;
        if (!status) {
@@ -4600,6 +4590,10 @@ int rdma_join_multicast(struct rdma_cm_id *id, struct sockaddr *addr,
        struct cma_multicast *mc;
        int ret;
 
+       /* Not supported for kernel QPs */
+       if (WARN_ON(id->qp))
+               return -EINVAL;
+
        /* ULP is calling this wrong. */
        if (!id->device || (READ_ONCE(id_priv->state) != RDMA_CM_ADDR_BOUND &&
                            READ_ONCE(id_priv->state) != RDMA_CM_ADDR_RESOLVED))
@@ -4651,11 +4645,6 @@ void rdma_leave_multicast(struct rdma_cm_id *id, struct sockaddr *addr)
                        list_del(&mc->list);
                        spin_unlock_irq(&id_priv->lock);
 
-                       if (id->qp)
-                               ib_detach_mcast(id->qp,
-                                               &mc->multicast.ib->rec.mgid,
-                                               be16_to_cpu(mc->multicast.ib->rec.mlid));
-
                        BUG_ON(id_priv->cma_dev->device != id->device);
 
                        if (rdma_cap_ib_mcast(id->device, id->port_num)) {