RDMA/cma: Pass QP type into rdma_create_id()

The RDMA CM currently infers the QP type from the port space selected
by the user.  In the future (eg with RDMA_PS_IB or XRC), there may not
be a 1-1 correspondence between port space and QP type.  For netlink
export of RDMA CM state, we want to export the QP type to userspace,
so it is cleaner to explicitly associate a QP type to an ID.

Modify rdma_create_id() to allow the user to specify the QP type, and
use it to make our selections of datagram versus connected mode.

Signed-off-by: Sean Hefty <sean.hefty@intel.com>
Signed-off-by: Roland Dreier <roland@purestorage.com>
diff --git a/drivers/infiniband/core/ucma.c b/drivers/infiniband/core/ucma.c
index b3fa798..7109d5d 100644
--- a/drivers/infiniband/core/ucma.c
+++ b/drivers/infiniband/core/ucma.c
@@ -367,13 +367,28 @@
 	return ret;
 }
 
-static ssize_t ucma_create_id(struct ucma_file *file,
-				const char __user *inbuf,
-				int in_len, int out_len)
+static int ucma_get_qp_type(struct rdma_ucm_create_id *cmd, enum ib_qp_type *qp_type)
+{
+	switch (cmd->ps) {
+	case RDMA_PS_TCP:
+		*qp_type = IB_QPT_RC;
+		return 0;
+	case RDMA_PS_UDP:
+	case RDMA_PS_IPOIB:
+		*qp_type = IB_QPT_UD;
+		return 0;
+	default:
+		return -EINVAL;
+	}
+}
+
+static ssize_t ucma_create_id(struct ucma_file *file, const char __user *inbuf,
+			      int in_len, int out_len)
 {
 	struct rdma_ucm_create_id cmd;
 	struct rdma_ucm_create_id_resp resp;
 	struct ucma_context *ctx;
+	enum ib_qp_type qp_type;
 	int ret;
 
 	if (out_len < sizeof(resp))
@@ -382,6 +397,10 @@
 	if (copy_from_user(&cmd, inbuf, sizeof(cmd)))
 		return -EFAULT;
 
+	ret = ucma_get_qp_type(&cmd, &qp_type);
+	if (ret)
+		return ret;
+
 	mutex_lock(&file->mut);
 	ctx = ucma_alloc_ctx(file);
 	mutex_unlock(&file->mut);
@@ -389,7 +408,7 @@
 		return -ENOMEM;
 
 	ctx->uid = cmd.uid;
-	ctx->cm_id = rdma_create_id(ucma_event_handler, ctx, cmd.ps);
+	ctx->cm_id = rdma_create_id(ucma_event_handler, ctx, cmd.ps, qp_type);
 	if (IS_ERR(ctx->cm_id)) {
 		ret = PTR_ERR(ctx->cm_id);
 		goto err1;