IB/mlx5: Add support for DC target QP

A DC Target (DCT) QP is represented in the hardware as a unique object.
This object is created by CREATE_DCT command and destroyed by DESTROY_DCT
command. However, in the driver we describe it as a QP.

The hardware command that creates a DCT needs parameters that the verb
create_qp() does not provide. Those remaining parameters are provided
with the call to the verb modify_qp(). Therefore we delay the actual
creation of a DCT in the hardware until the stage of modify_qp() to RTR.

A support for query_qp() was added as well. It uses QUERY_DCT command to
retrieve the applicable fields.

Signed-off-by: Moni Shoua <monis@mellanox.com>
Reviewed-by: Yishai Hadas <yishaih@mellanox.com>
Signed-off-by: Leon Romanovsky <leon@kernel.org>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
diff --git a/drivers/infiniband/hw/mlx5/main.c b/drivers/infiniband/hw/mlx5/main.c
index b9e195d..675144a 100644
--- a/drivers/infiniband/hw/mlx5/main.c
+++ b/drivers/infiniband/hw/mlx5/main.c
@@ -436,11 +436,11 @@ static int mlx5_get_vport_access_method(struct ib_device *ibdev)
 }
 
 static void get_atomic_caps(struct mlx5_ib_dev *dev,
+			    u8 atomic_size_qp,
 			    struct ib_device_attr *props)
 {
 	u8 tmp;
 	u8 atomic_operations = MLX5_CAP_ATOMIC(dev->mdev, atomic_operations);
-	u8 atomic_size_qp = MLX5_CAP_ATOMIC(dev->mdev, atomic_size_qp);
 	u8 atomic_req_8B_endianness_mode =
 		MLX5_CAP_ATOMIC(dev->mdev, atomic_req_8B_endianness_mode);
 
@@ -457,6 +457,29 @@ static void get_atomic_caps(struct mlx5_ib_dev *dev,
 	}
 }
 
+static void get_atomic_caps_qp(struct mlx5_ib_dev *dev,
+			       struct ib_device_attr *props)
+{
+	u8 atomic_size_qp = MLX5_CAP_ATOMIC(dev->mdev, atomic_size_qp);
+
+	get_atomic_caps(dev, atomic_size_qp, props);
+}
+
+static void get_atomic_caps_dc(struct mlx5_ib_dev *dev,
+			       struct ib_device_attr *props)
+{
+	u8 atomic_size_qp = MLX5_CAP_ATOMIC(dev->mdev, atomic_size_dc);
+
+	get_atomic_caps(dev, atomic_size_qp, props);
+}
+
+bool mlx5_ib_dc_atomic_is_supported(struct mlx5_ib_dev *dev)
+{
+	struct ib_device_attr props = {};
+
+	get_atomic_caps_dc(dev, &props);
+	return (props.atomic_cap == IB_ATOMIC_HCA) ? true : false;
+}
 static int mlx5_query_system_image_guid(struct ib_device *ibdev,
 					__be64 *sys_image_guid)
 {
@@ -745,7 +768,7 @@ static int mlx5_ib_query_device(struct ib_device *ibdev,
 	props->max_srq_sge	   = max_rq_sg - 1;
 	props->max_fast_reg_page_list_len =
 		1 << MLX5_CAP_GEN(mdev, log_max_klm_list_size);
-	get_atomic_caps(dev, props);
+	get_atomic_caps_qp(dev, props);
 	props->masked_atomic_cap   = IB_ATOMIC_NONE;
 	props->max_mcast_grp	   = 1 << MLX5_CAP_GEN(mdev, log_max_mcg);
 	props->max_mcast_qp_attach = MLX5_CAP_GEN(mdev, max_qp_mcg);