RDMA/mlx5: Support OOO RX WQE consumption

Support QP with out-of-order (OOO) capabilities enabled.
This allows WRs on the receiver side of the QP to be consumed OOO,
permitting the sender side to transmit messages without guaranteeing
arrival order on the receiver side.

When enabled, the completion ordering of WRs remains in-order,
regardless of the Receive WRs consumption order.
RDMA Read and RDMA Atomic operations on the responder side continue to
be executed in-order, while the ordering of data placement for RDMA
Write and Send operations is not guaranteed.

Atomic operations larger than 8 bytes are currently not supported.
Therefore, when this feature is enabled, the created QP restricts its
atomic support to 8 bytes at most.

In addition, when querying the device, a new flag is returned in
response to indicate that the Kernel supports OOO QP.

Signed-off-by: Edward Srouji <edwards@nvidia.com>
Reviewed-by: Yishai Hadas <yishaih@nvidia.com>
Link: https://patch.msgid.link/06ac609a5f358c8fb0a090d22c61a2f9329d82e6.1725362773.git.leon@kernel.org
Signed-off-by: Leon Romanovsky <leon@kernel.org>

3 files changed, 55 insertions, 5 deletions

diff --git a/drivers/infiniband/hw/mlx5/main.c b/drivers/infiniband/hw/mlx5/main.c
index 4999239c8f41..b4476df96ed5 100644
--- a/drivers/infiniband/hw/mlx5/main.c
+++ b/drivers/infiniband/hw/mlx5/main.c
@@ -1182,6 +1182,14 @@ static int mlx5_ib_query_device(struct ib_device *ibdev,
 				MLX5_IB_QUERY_DEV_RESP_PACKET_BASED_CREDIT_MODE;
 
 		resp.flags |= MLX5_IB_QUERY_DEV_RESP_FLAGS_SCAT2CQE_DCT;
+
+		if (MLX5_CAP_GEN_2(mdev, dp_ordering_force) &&
+		    (MLX5_CAP_GEN(mdev, dp_ordering_ooo_all_xrc) ||
+		    MLX5_CAP_GEN(mdev, dp_ordering_ooo_all_dc) ||
+		    MLX5_CAP_GEN(mdev, dp_ordering_ooo_all_rc) ||
+		    MLX5_CAP_GEN(mdev, dp_ordering_ooo_all_ud) ||
+		    MLX5_CAP_GEN(mdev, dp_ordering_ooo_all_uc)))
+			resp.flags |= MLX5_IB_QUERY_DEV_RESP_FLAGS_OOO_DP;
 	}
 
 	if (offsetofend(typeof(resp), sw_parsing_caps) <= uhw_outlen) {
diff --git a/drivers/infiniband/hw/mlx5/mlx5_ib.h b/drivers/infiniband/hw/mlx5/mlx5_ib.h
index 23fd72f7f63d..ed4eaaa7ac71 100644
--- a/drivers/infiniband/hw/mlx5/mlx5_ib.h
+++ b/drivers/infiniband/hw/mlx5/mlx5_ib.h
@@ -521,6 +521,7 @@ struct mlx5_ib_qp {
 	struct mlx5_bf	        bf;
 	u8			has_rq:1;
 	u8			is_rss:1;
+	u8			is_ooo_rq:1;
 
 	/* only for user space QPs. For kernel
 	 * we have it from the bf object
diff --git a/drivers/infiniband/hw/mlx5/qp.c b/drivers/infiniband/hw/mlx5/qp.c
index e39b1a101e97..837b662b41de 100644
--- a/drivers/infiniband/hw/mlx5/qp.c
+++ b/drivers/infiniband/hw/mlx5/qp.c
@@ -1960,7 +1960,7 @@ static int atomic_size_to_mode(int size_mask)
 }
 
 static int get_atomic_mode(struct mlx5_ib_dev *dev,
-			   enum ib_qp_type qp_type)
+			   struct mlx5_ib_qp *qp)
 {
 	u8 atomic_operations = MLX5_CAP_ATOMIC(dev->mdev, atomic_operations);
 	u8 atomic = MLX5_CAP_GEN(dev->mdev, atomic);
@@ -1970,7 +1970,7 @@ static int get_atomic_mode(struct mlx5_ib_dev *dev,
 	if (!atomic)
 		return -EOPNOTSUPP;
 
-	if (qp_type == MLX5_IB_QPT_DCT)
+	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);
@@ -1984,6 +1984,10 @@ static int get_atomic_mode(struct mlx5_ib_dev *dev,
 	     atomic_operations & MLX5_ATOMIC_OPS_FETCH_ADD))
 		atomic_mode = MLX5_ATOMIC_MODE_IB_COMP;
 
+	/* OOO DP QPs do not support larger than 8-Bytes atomic operations */
+	if (atomic_mode > MLX5_ATOMIC_MODE_8B && qp->is_ooo_rq)
+		atomic_mode = MLX5_ATOMIC_MODE_8B;
+
 	return atomic_mode;
 }
 
@@ -2839,6 +2843,29 @@ static int check_valid_flow(struct mlx5_ib_dev *dev, struct ib_pd *pd,
 	return 0;
 }
 
+static bool get_dp_ooo_cap(struct mlx5_core_dev *mdev, enum ib_qp_type qp_type)
+{
+	if (!MLX5_CAP_GEN_2(mdev, dp_ordering_force))
+		return false;
+
+	switch (qp_type) {
+	case IB_QPT_RC:
+		return MLX5_CAP_GEN(mdev, dp_ordering_ooo_all_rc);
+	case IB_QPT_XRC_INI:
+	case IB_QPT_XRC_TGT:
+		return MLX5_CAP_GEN(mdev, dp_ordering_ooo_all_xrc);
+	case IB_QPT_UC:
+		return MLX5_CAP_GEN(mdev, dp_ordering_ooo_all_uc);
+	case IB_QPT_UD:
+		return MLX5_CAP_GEN(mdev, dp_ordering_ooo_all_ud);
+	case MLX5_IB_QPT_DCI:
+	case MLX5_IB_QPT_DCT:
+		return MLX5_CAP_GEN(mdev, dp_ordering_ooo_all_dc);
+	default:
+		return false;
+	}
+}
+
 static void process_vendor_flag(struct mlx5_ib_dev *dev, int *flags, int flag,
 				bool cond, struct mlx5_ib_qp *qp)
 {
@@ -3365,7 +3392,7 @@ static int set_qpc_atomic_flags(struct mlx5_ib_qp *qp,
 	if (access_flags & IB_ACCESS_REMOTE_ATOMIC) {
 		int atomic_mode;
 
-		atomic_mode = get_atomic_mode(dev, qp->type);
+		atomic_mode = get_atomic_mode(dev, qp);
 		if (atomic_mode < 0)
 			return -EOPNOTSUPP;
 
@@ -4316,6 +4343,11 @@ static int __mlx5_ib_modify_qp(struct ib_qp *ibqp,
 	if (qp->flags & MLX5_IB_QP_CREATE_SQPN_QP1)
 		MLX5_SET(qpc, qpc, deth_sqpn, 1);
 
+	if (qp->is_ooo_rq && cur_state == IB_QPS_INIT && new_state == IB_QPS_RTR) {
+		MLX5_SET(qpc, qpc, dp_ordering_1, 1);
+		MLX5_SET(qpc, qpc, dp_ordering_force, 1);
+	}
+
 	mlx5_cur = to_mlx5_state(cur_state);
 	mlx5_new = to_mlx5_state(new_state);
 
@@ -4531,7 +4563,7 @@ static int mlx5_ib_modify_dct(struct ib_qp *ibqp, struct ib_qp_attr *attr,
 		if (attr->qp_access_flags & IB_ACCESS_REMOTE_ATOMIC) {
 			int atomic_mode;
 
-			atomic_mode = get_atomic_mode(dev, MLX5_IB_QPT_DCT);
+			atomic_mode = get_atomic_mode(dev, qp);
 			if (atomic_mode < 0)
 				return -EOPNOTSUPP;
 
@@ -4573,6 +4605,10 @@ static int mlx5_ib_modify_dct(struct ib_qp *ibqp, struct ib_qp_attr *attr,
 		MLX5_SET(dctc, dctc, hop_limit, attr->ah_attr.grh.hop_limit);
 		if (attr->ah_attr.type == RDMA_AH_ATTR_TYPE_ROCE)
 			MLX5_SET(dctc, dctc, eth_prio, attr->ah_attr.sl & 0x7);
+		if (qp->is_ooo_rq) {
+			MLX5_SET(dctc, dctc, dp_ordering_1, 1);
+			MLX5_SET(dctc, dctc, dp_ordering_force, 1);
+		}
 
 		err = mlx5_core_create_dct(dev, &qp->dct.mdct, qp->dct.in,
 					   MLX5_ST_SZ_BYTES(create_dct_in), out,
@@ -4676,11 +4712,16 @@ int mlx5_ib_modify_qp(struct ib_qp *ibqp, struct ib_qp_attr *attr,
 				       min(udata->inlen, sizeof(ucmd))))
 			return -EFAULT;
 
-		if (ucmd.comp_mask ||
+		if (ucmd.comp_mask & ~MLX5_IB_MODIFY_QP_OOO_DP ||
 		    memchr_inv(&ucmd.burst_info.reserved, 0,
 			       sizeof(ucmd.burst_info.reserved)))
 			return -EOPNOTSUPP;
 
+		if (ucmd.comp_mask & MLX5_IB_MODIFY_QP_OOO_DP) {
+			if (!get_dp_ooo_cap(dev->mdev, qp->type))
+				return -EOPNOTSUPP;
+			qp->is_ooo_rq = 1;
+		}
 	}
 
 	if (qp->type == IB_QPT_GSI)