diff --git a/drivers/infiniband/hw/mlx5/qp.c b/drivers/infiniband/hw/mlx5/qp.c
index 368728e6f980..6841c0f9237f 100644
--- a/drivers/infiniband/hw/mlx5/qp.c
+++ b/drivers/infiniband/hw/mlx5/qp.c
@@ -1733,6 +1733,53 @@ static void configure_requester_scat_cqe(struct mlx5_ib_dev *dev,
 		MLX5_SET(qpc, qpc, cs_req, MLX5_REQ_SCAT_DATA32_CQE);
 }
 
+static int atomic_size_to_mode(int size_mask)
+{
+	/* driver does not support atomic_size > 256B
+	 * and does not know how to translate bigger sizes
+	 */
+	int supported_size_mask = size_mask & 0x1ff;
+	int log_max_size;
+
+	if (!supported_size_mask)
+		return -EOPNOTSUPP;
+
+	log_max_size = __fls(supported_size_mask);
+
+	if (log_max_size > 3)
+		return log_max_size;
+
+	return MLX5_ATOMIC_MODE_8B;
+}
+
+static int get_atomic_mode(struct mlx5_ib_dev *dev,
+			   enum ib_qp_type qp_type)
+{
+	u8 atomic_operations = MLX5_CAP_ATOMIC(dev->mdev, atomic_operations);
+	u8 atomic = MLX5_CAP_GEN(dev->mdev, atomic);
+	int atomic_mode = -EOPNOTSUPP;
+	int atomic_size_mask;
+
+	if (!atomic)
+		return -EOPNOTSUPP;
+
+	if (qp_type == MLX5_IB_QPT_DCT)
+		atomic_size_mask = MLX5_CAP_ATOMIC(dev->mdev, atomic_size_dc);
+	else
+		atomic_size_mask = MLX5_CAP_ATOMIC(dev->mdev, atomic_size_qp);
+
+	if ((atomic_operations & MLX5_ATOMIC_OPS_EXTENDED_CMP_SWAP) ||
+	    (atomic_operations & MLX5_ATOMIC_OPS_EXTENDED_FETCH_ADD))
+		atomic_mode = atomic_size_to_mode(atomic_size_mask);
+
+	if (atomic_mode <= 0 &&
+	    (atomic_operations & MLX5_ATOMIC_OPS_CMP_SWAP &&
+	     atomic_operations & MLX5_ATOMIC_OPS_FETCH_ADD))
+		atomic_mode = MLX5_ATOMIC_MODE_IB_COMP;
+
+	return atomic_mode;
+}
+
 static inline bool check_flags_mask(uint64_t input, uint64_t supported)
 {
 	return (input & ~supported) == 0;
@@ -2562,13 +2609,15 @@ int mlx5_ib_destroy_qp(struct ib_qp *qp)
 	return 0;
 }
 
-static __be32 to_mlx5_access_flags(struct mlx5_ib_qp *qp, const struct ib_qp_attr *attr,
-				   int attr_mask)
+static int to_mlx5_access_flags(struct mlx5_ib_qp *qp,
+				const struct ib_qp_attr *attr,
+				int attr_mask, __be32 *hw_access_flags)
 {
-	u32 hw_access_flags = 0;
 	u8 dest_rd_atomic;
 	u32 access_flags;
 
+	struct mlx5_ib_dev *dev = to_mdev(qp->ibqp.device);
+
 	if (attr_mask & IB_QP_MAX_DEST_RD_ATOMIC)
 		dest_rd_atomic = attr->max_dest_rd_atomic;
 	else
@@ -2583,13 +2632,25 @@ static __be32 to_mlx5_access_flags(struct mlx5_ib_qp *qp, const struct ib_qp_att
 		access_flags &= IB_ACCESS_REMOTE_WRITE;
 
 	if (access_flags & IB_ACCESS_REMOTE_READ)
-		hw_access_flags |= MLX5_QP_BIT_RRE;
-	if (access_flags & IB_ACCESS_REMOTE_ATOMIC)
-		hw_access_flags |= (MLX5_QP_BIT_RAE | MLX5_ATOMIC_MODE_CX);
-	if (access_flags & IB_ACCESS_REMOTE_WRITE)
-		hw_access_flags |= MLX5_QP_BIT_RWE;
+		*hw_access_flags |= MLX5_QP_BIT_RRE;
+	if ((access_flags & IB_ACCESS_REMOTE_ATOMIC) &&
+	    qp->ibqp.qp_type == IB_QPT_RC) {
+		int atomic_mode;
 
-	return cpu_to_be32(hw_access_flags);
+		atomic_mode = get_atomic_mode(dev, qp->ibqp.qp_type);
+		if (atomic_mode < 0)
+			return -EOPNOTSUPP;
+
+		*hw_access_flags |= MLX5_QP_BIT_RAE;
+		*hw_access_flags |= atomic_mode << MLX5_ATOMIC_MODE_OFFSET;
+	}
+
+	if (access_flags & IB_ACCESS_REMOTE_WRITE)
+		*hw_access_flags |= MLX5_QP_BIT_RWE;
+
+	*hw_access_flags = cpu_to_be32(*hw_access_flags);
+
+	return 0;
 }
 
 enum {
@@ -3287,8 +3348,15 @@ static int __mlx5_ib_modify_qp(struct ib_qp *ibqp,
 				cpu_to_be32(fls(attr->max_dest_rd_atomic - 1) << 21);
 	}
 
-	if (attr_mask & (IB_QP_ACCESS_FLAGS | IB_QP_MAX_DEST_RD_ATOMIC))
-		context->params2 |= to_mlx5_access_flags(qp, attr, attr_mask);
+	if (attr_mask & (IB_QP_ACCESS_FLAGS | IB_QP_MAX_DEST_RD_ATOMIC)) {
+		__be32 access_flags = 0;
+
+		err = to_mlx5_access_flags(qp, attr, attr_mask, &access_flags);
+		if (err)
+			goto out;
+
+		context->params2 |= access_flags;
+	}
 
 	if (attr_mask & IB_QP_MIN_RNR_TIMER)
 		context->rnr_nextrecvpsn |= cpu_to_be32(attr->min_rnr_timer << 24);
@@ -3504,10 +3572,14 @@ static int mlx5_ib_modify_dct(struct ib_qp *ibqp, struct ib_qp_attr *attr,
 		if (attr->qp_access_flags & IB_ACCESS_REMOTE_WRITE)
 			MLX5_SET(dctc, dctc, rwe, 1);
 		if (attr->qp_access_flags & IB_ACCESS_REMOTE_ATOMIC) {
-			if (!mlx5_ib_dc_atomic_is_supported(dev))
+			int atomic_mode;
+
+			atomic_mode = get_atomic_mode(dev, MLX5_IB_QPT_DCT);
+			if (atomic_mode < 0)
 				return -EOPNOTSUPP;
+
+			MLX5_SET(dctc, dctc, atomic_mode, atomic_mode);
 			MLX5_SET(dctc, dctc, rae, 1);
-			MLX5_SET(dctc, dctc, atomic_mode, MLX5_ATOMIC_MODE_DCT_CX);
 		}
 		MLX5_SET(dctc, dctc, pkey_index, attr->pkey_index);
 		MLX5_SET(dctc, dctc, port, attr->port_num);
diff --git a/include/linux/mlx5/driver.h b/include/linux/mlx5/driver.h
index 8fb072aa8671..a73c701edd16 100644
--- a/include/linux/mlx5/driver.h
+++ b/include/linux/mlx5/driver.h
@@ -97,14 +97,15 @@ enum {
 };
 
 enum {
-	MLX5_ATOMIC_MODE_IB_COMP	= 1 << 16,
-	MLX5_ATOMIC_MODE_CX		= 2 << 16,
-	MLX5_ATOMIC_MODE_8B		= 3 << 16,
-	MLX5_ATOMIC_MODE_16B		= 4 << 16,
-	MLX5_ATOMIC_MODE_32B		= 5 << 16,
-	MLX5_ATOMIC_MODE_64B		= 6 << 16,
-	MLX5_ATOMIC_MODE_128B		= 7 << 16,
-	MLX5_ATOMIC_MODE_256B		= 8 << 16,
+	MLX5_ATOMIC_MODE_OFFSET = 16,
+	MLX5_ATOMIC_MODE_IB_COMP = 1,
+	MLX5_ATOMIC_MODE_CX = 2,
+	MLX5_ATOMIC_MODE_8B = 3,
+	MLX5_ATOMIC_MODE_16B = 4,
+	MLX5_ATOMIC_MODE_32B = 5,
+	MLX5_ATOMIC_MODE_64B = 6,
+	MLX5_ATOMIC_MODE_128B = 7,
+	MLX5_ATOMIC_MODE_256B = 8,
 };
 
 enum {
@@ -162,13 +163,11 @@ enum mlx5_dcbx_oper_mode {
 	MLX5E_DCBX_PARAM_VER_OPER_AUTO  = 0x3,
 };
 
-enum mlx5_dct_atomic_mode {
-	MLX5_ATOMIC_MODE_DCT_CX         = 2,
-};
-
 enum {
 	MLX5_ATOMIC_OPS_CMP_SWAP	= 1 << 0,
 	MLX5_ATOMIC_OPS_FETCH_ADD	= 1 << 1,
+	MLX5_ATOMIC_OPS_EXTENDED_CMP_SWAP = 1 << 2,
+	MLX5_ATOMIC_OPS_EXTENDED_FETCH_ADD = 1 << 3,
 };
 
 enum mlx5_page_fault_resume_flags {