net/mlx5e: Support HTB offload

This commit adds support for HTB offload in the mlx5e driver.

Performance:

  NIC: Mellanox ConnectX-6 Dx
  CPU: Intel(R) Xeon(R) CPU E5-2680 v3 @ 2.50GHz (24 cores with HT)

  100 Gbit/s line rate, 500 UDP streams @ ~200 Mbit/s each
  48 traffic classes, flower used for steering
  No shaping (rate limits set to 4 Gbit/s per TC) - checking for max
  throughput.

  Baseline: 98.7 Gbps, 8.25 Mpps
  HTB: 6.7 Gbps, 0.56 Mpps
  HTB offload: 95.6 Gbps, 8.00 Mpps

Limitations:

1. 256 leaf nodes, 3 levels of depth.

2. Granularity for ceil is 1 Mbit/s. Rates are converted to weights, and
the bandwidth is split among the siblings according to these weights.
Other parameters for classes are not supported.

Ethtool statistics support for QoS SQs are also added. The counters are
called qos_txN_*, where N is the QoS queue number (starting from 0, the
numeration is separate from the normal SQs), and * is the counter name
(the counters are the same as for the normal SQs).

Signed-off-by: Maxim Mikityanskiy <maximmi@mellanox.com>
Reviewed-by: Tariq Toukan <tariqt@nvidia.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

1 files changed, 85 insertions, 0 deletions

diff --git a/drivers/net/ethernet/mellanox/mlx5/core/qos.c b/drivers/net/ethernet/mellanox/mlx5/core/qos.c
new file mode 100644
index 000000000000..0777be24a307
--- /dev/null
+++ b/drivers/net/ethernet/mellanox/mlx5/core/qos.c
@@ -0,0 +1,85 @@
+// SPDX-License-Identifier: GPL-2.0 OR Linux-OpenIB
+/* Copyright (c) 2020, Mellanox Technologies inc. All rights reserved. */
+
+#include "qos.h"
+
+#define MLX5_QOS_DEFAULT_DWRR_UID 0
+
+bool mlx5_qos_is_supported(struct mlx5_core_dev *mdev)
+{
+	if (!MLX5_CAP_GEN(mdev, qos))
+		return false;
+	if (!MLX5_CAP_QOS(mdev, nic_sq_scheduling))
+		return false;
+	if (!MLX5_CAP_QOS(mdev, nic_bw_share))
+		return false;
+	if (!MLX5_CAP_QOS(mdev, nic_rate_limit))
+		return false;
+	return true;
+}
+
+int mlx5_qos_max_leaf_nodes(struct mlx5_core_dev *mdev)
+{
+	return 1 << MLX5_CAP_QOS(mdev, log_max_qos_nic_queue_group);
+}
+
+int mlx5_qos_create_leaf_node(struct mlx5_core_dev *mdev, u32 parent_id,
+			      u32 bw_share, u32 max_avg_bw, u32 *id)
+{
+	u32 sched_ctx[MLX5_ST_SZ_DW(scheduling_context)] = {0};
+
+	MLX5_SET(scheduling_context, sched_ctx, parent_element_id, parent_id);
+	MLX5_SET(scheduling_context, sched_ctx, element_type,
+		 SCHEDULING_CONTEXT_ELEMENT_TYPE_QUEUE_GROUP);
+	MLX5_SET(scheduling_context, sched_ctx, bw_share, bw_share);
+	MLX5_SET(scheduling_context, sched_ctx, max_average_bw, max_avg_bw);
+
+	return mlx5_create_scheduling_element_cmd(mdev, SCHEDULING_HIERARCHY_NIC,
+						  sched_ctx, id);
+}
+
+int mlx5_qos_create_inner_node(struct mlx5_core_dev *mdev, u32 parent_id,
+			       u32 bw_share, u32 max_avg_bw, u32 *id)
+{
+	u32 sched_ctx[MLX5_ST_SZ_DW(scheduling_context)] = {0};
+	void *attr;
+
+	MLX5_SET(scheduling_context, sched_ctx, parent_element_id, parent_id);
+	MLX5_SET(scheduling_context, sched_ctx, element_type,
+		 SCHEDULING_CONTEXT_ELEMENT_TYPE_TSAR);
+	MLX5_SET(scheduling_context, sched_ctx, bw_share, bw_share);
+	MLX5_SET(scheduling_context, sched_ctx, max_average_bw, max_avg_bw);
+
+	attr = MLX5_ADDR_OF(scheduling_context, sched_ctx, element_attributes);
+	MLX5_SET(tsar_element, attr, tsar_type, TSAR_ELEMENT_TSAR_TYPE_DWRR);
+
+	return mlx5_create_scheduling_element_cmd(mdev, SCHEDULING_HIERARCHY_NIC,
+						  sched_ctx, id);
+}
+
+int mlx5_qos_create_root_node(struct mlx5_core_dev *mdev, u32 *id)
+{
+	return mlx5_qos_create_inner_node(mdev, MLX5_QOS_DEFAULT_DWRR_UID, 0, 0, id);
+}
+
+int mlx5_qos_update_node(struct mlx5_core_dev *mdev, u32 parent_id,
+			 u32 bw_share, u32 max_avg_bw, u32 id)
+{
+	u32 sched_ctx[MLX5_ST_SZ_DW(scheduling_context)] = {0};
+	u32 bitmask = 0;
+
+	MLX5_SET(scheduling_context, sched_ctx, parent_element_id, parent_id);
+	MLX5_SET(scheduling_context, sched_ctx, bw_share, bw_share);
+	MLX5_SET(scheduling_context, sched_ctx, max_average_bw, max_avg_bw);
+
+	bitmask |= MODIFY_SCHEDULING_ELEMENT_IN_MODIFY_BITMASK_BW_SHARE;
+	bitmask |= MODIFY_SCHEDULING_ELEMENT_IN_MODIFY_BITMASK_MAX_AVERAGE_BW;
+
+	return mlx5_modify_scheduling_element_cmd(mdev, SCHEDULING_HIERARCHY_NIC,
+						  sched_ctx, id, bitmask);
+}
+
+int mlx5_qos_destroy_node(struct mlx5_core_dev *mdev, u32 id)
+{
+	return mlx5_destroy_scheduling_element_cmd(mdev, SCHEDULING_HIERARCHY_NIC, id);
+}