IB/mlx5: Handle type IB_QPT_DRIVER when creating a QP

The QP type IB_QPT_DRIVER doesn't describe the transport or the service
that the QP provides but those are known only to the hardware driver.
The actual type of the QP is stored in the hardware driver context (i.e.
mlx5_qp) under the field qp_sub_type.

Take the real QP type and any extra data that is required to create the QP
from the driver channel and modify the QP initial attributes before continuing
with create_qp().

Downstream patches from this series will add support for both DCI and
DCT driver QPs.

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>

drivers/infiniband/hw/mlx5/mlx5_ib.h

@@ -206,6 +206,8 @@ struct mlx5_ib_flow_db {
  * creates the actual hardware QP.
  */
 #define MLX5_IB_QPT_HW_GSI	IB_QPT_RESERVED2
+#define MLX5_IB_QPT_DCI		IB_QPT_RESERVED3
+#define MLX5_IB_QPT_DCT		IB_QPT_RESERVED4
 #define MLX5_IB_WR_UMR		IB_WR_RESERVED1
 
 #define MLX5_IB_UMR_OCTOWORD	       16
@@ -366,12 +368,18 @@ struct mlx5_bf {
 	struct mlx5_sq_bfreg   *bfreg;
 };
 
+struct mlx5_ib_dct {
+	struct mlx5_core_dct    mdct;
+	u32                     *in;
+};
+
 struct mlx5_ib_qp {
 	struct ib_qp		ibqp;
 	union {
 		struct mlx5_ib_qp_trans trans_qp;
 		struct mlx5_ib_raw_packet_qp raw_packet_qp;
 		struct mlx5_ib_rss_qp rss_qp;
+		struct mlx5_ib_dct dct;
 	};
 	struct mlx5_buf		buf;
 
@@ -410,6 +418,8 @@ struct mlx5_ib_qp {
 	u32			rate_limit;
 	u32                     underlay_qpn;
 	bool			tunnel_offload_en;
+	/* storage for qp sub type when core qp type is IB_QPT_DRIVER */
+	enum ib_qp_type		qp_sub_type;
 };
 
 struct mlx5_ib_cq_buf {

drivers/infiniband/hw/mlx5/qp.c

@@ -2115,20 +2115,108 @@ static const char *ib_qp_type_str(enum ib_qp_type type)
 		return "IB_QPT_RAW_PACKET";
 	case MLX5_IB_QPT_REG_UMR:
 		return "MLX5_IB_QPT_REG_UMR";
+	case IB_QPT_DRIVER:
+		return "IB_QPT_DRIVER";
 	case IB_QPT_MAX:
 	default:
 		return "Invalid QP type";
 	}
 }
 
+static struct ib_qp *mlx5_ib_create_dct(struct ib_pd *pd,
+					struct ib_qp_init_attr *attr,
+					struct mlx5_ib_create_qp *ucmd)
+{
+	struct mlx5_ib_dev *dev;
+	struct mlx5_ib_qp *qp;
+	int err = 0;
+	u32 uidx = MLX5_IB_DEFAULT_UIDX;
+	void *dctc;
+
+	if (!attr->srq || !attr->recv_cq)
+		return ERR_PTR(-EINVAL);
+
+	dev = to_mdev(pd->device);
+
+	err = get_qp_user_index(to_mucontext(pd->uobject->context),
+				ucmd, sizeof(*ucmd), &uidx);
+	if (err)
+		return ERR_PTR(err);
+
+	qp = kzalloc(sizeof(*qp), GFP_KERNEL);
+	if (!qp)
+		return ERR_PTR(-ENOMEM);
+
+	qp->dct.in = kzalloc(MLX5_ST_SZ_BYTES(create_dct_in), GFP_KERNEL);
+	if (!qp->dct.in) {
+		err = -ENOMEM;
+		goto err_free;
+	}
+
+	dctc = MLX5_ADDR_OF(create_dct_in, qp->dct.in, dct_context_entry);
+	qp->driver_qp_type = MLX5_IB_QPT_DCT;
+	MLX5_SET(dctc, dctc, pd, to_mpd(pd)->pdn);
+	MLX5_SET(dctc, dctc, srqn_xrqn, to_msrq(attr->srq)->msrq.srqn);
+	MLX5_SET(dctc, dctc, cqn, to_mcq(attr->recv_cq)->mcq.cqn);
+	MLX5_SET64(dctc, dctc, dc_access_key, ucmd->access_key);
+	MLX5_SET(dctc, dctc, user_index, uidx);
+
+	qp->state = IB_QPS_RESET;
+
+	return &qp->ibqp;
+err_free:
+	kfree(qp);
+	return ERR_PTR(err);
+}
+
+static int set_mlx_qp_type(struct mlx5_ib_dev *dev,
+			   struct ib_qp_init_attr *init_attr,
+			   struct mlx5_ib_create_qp *ucmd,
+			   struct ib_udata *udata)
+{
+	enum { MLX_QP_FLAGS = MLX5_QP_FLAG_TYPE_DCT | MLX5_QP_FLAG_TYPE_DCI };
+	int err;
+
+	if (!udata)
+		return -EINVAL;
+
+	if (udata->inlen < sizeof(*ucmd)) {
+		mlx5_ib_dbg(dev, "create_qp user command is smaller than expected\n");
+		return -EINVAL;
+	}
+	err = ib_copy_from_udata(ucmd, udata, sizeof(*ucmd));
+	if (err)
+		return err;
+
+	if ((ucmd->flags & MLX_QP_FLAGS) == MLX5_QP_FLAG_TYPE_DCI) {
+		init_attr->qp_type = MLX5_IB_QPT_DCI;
+	} else {
+		if ((ucmd->flags & MLX_QP_FLAGS) == MLX5_QP_FLAG_TYPE_DCT) {
+			init_attr->qp_type = MLX5_IB_QPT_DCT;
+		} else {
+			mlx5_ib_dbg(dev, "Invalid QP flags\n");
+			return -EINVAL;
+		}
+	}
+
+	if (!MLX5_CAP_GEN(dev->mdev, dct)) {
+		mlx5_ib_dbg(dev, "DC transport is not supported\n");
+		return -EOPNOTSUPP;
+	}
+
+	return 0;
+}
+
 struct ib_qp *mlx5_ib_create_qp(struct ib_pd *pd,
-				struct ib_qp_init_attr *init_attr,
+				struct ib_qp_init_attr *verbs_init_attr,
 				struct ib_udata *udata)
 {
 	struct mlx5_ib_dev *dev;
 	struct mlx5_ib_qp *qp;
 	u16 xrcdn = 0;
 	int err;
+	struct ib_qp_init_attr mlx_init_attr;
+	struct ib_qp_init_attr *init_attr = verbs_init_attr;
 
 	if (pd) {
 		dev = to_mdev(pd->device);
@@ -2153,6 +2241,16 @@ struct ib_qp *mlx5_ib_create_qp(struct ib_pd *pd,
 		dev = to_mdev(to_mxrcd(init_attr->xrcd)->ibxrcd.device);
 	}
 
+	if (init_attr->qp_type == IB_QPT_DRIVER) {
+		struct mlx5_ib_create_qp ucmd;
+
+		init_attr = &mlx_init_attr;
+		memcpy(init_attr, verbs_init_attr, sizeof(*verbs_init_attr));
+		err = set_mlx_qp_type(dev, init_attr, &ucmd, udata);
+		if (err)
+			return ERR_PTR(err);
+	}
+
 	switch (init_attr->qp_type) {
 	case IB_QPT_XRC_TGT:
 	case IB_QPT_XRC_INI:
@@ -2214,6 +2312,9 @@ struct ib_qp *mlx5_ib_create_qp(struct ib_pd *pd,
 		return ERR_PTR(-EINVAL);
 	}
 
+	if (verbs_init_attr->qp_type == IB_QPT_DRIVER)
+		qp->qp_sub_type = init_attr->qp_type;
+
 	return &qp->ibqp;
 }
 

include/uapi/rdma/mlx5-abi.h

@@ -42,6 +42,8 @@ enum {
 	MLX5_QP_FLAG_SCATTER_CQE	= 1 << 1,
 	MLX5_QP_FLAG_TUNNEL_OFFLOADS	= 1 << 2,
 	MLX5_QP_FLAG_BFREG_INDEX	= 1 << 3,
+	MLX5_QP_FLAG_TYPE_DCT		= 1 << 4,
+	MLX5_QP_FLAG_TYPE_DCI		= 1 << 5,
 };
 
 enum {
@@ -284,7 +286,10 @@ struct mlx5_ib_create_qp {
 	__u32	flags;
 	__u32	uidx;
 	__u32	bfreg_index;
-	__u64	sq_buf_addr;
+	union {
+		__u64	sq_buf_addr;
+		__u64	access_key;
+	};
 };
 
 /* RX Hash function flags */