[net-next 06/10] net/mlx5: Add MPEGC register configuration functionality

[Saeed Mahameed <saeedm@mellanox.com>]

From: Eran Ben Elisha <eranbe@mellanox.com>

MPEGC register is used to configure and access the PCIe general
configuration.

Expose set/get for TX lossy overflow and TX overflow sense which use the
MPEGC register. These will be used in a downstream patch via devlink
params.

Signed-off-by: Eran Ben Elisha <eranbe@mellanox.com>
Reviewed-by: Moshe Shemesh <moshe@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>
---
 .../net/ethernet/mellanox/mlx5/core/devlink.c | 123 ++++++++++++++++++
 .../net/ethernet/mellanox/mlx5/core/devlink.h |   1 +
 2 files changed, 124 insertions(+)

diff --git a/drivers/net/ethernet/mellanox/mlx5/core/devlink.c b/drivers/net/ethernet/mellanox/mlx5/core/devlink.c
index 2daf686bcc98..e3a5de6b4ee7 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/devlink.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/devlink.c
@@ -3,6 +3,129 @@
 
 #include <devlink.h>
 
+enum {
+	MLX5_DEVLINK_MPEGC_FIELD_SELECT_TX_OVERFLOW_DROP_EN = BIT(0),
+	MLX5_DEVLINK_MPEGC_FIELD_SELECT_TX_OVERFLOW_SENSE = BIT(3),
+	MLX5_DEVLINK_MPEGC_FIELD_SELECT_MARK_TX_ACTION_CQE = BIT(4),
+	MLX5_DEVLINK_MPEGC_FIELD_SELECT_MARK_TX_ACTION_CNP = BIT(5),
+};
+
+enum {
+	MLX5_DEVLINK_CONGESTION_ACTION_DISABLED,
+	MLX5_DEVLINK_CONGESTION_ACTION_DROP,
+	MLX5_DEVLINK_CONGESTION_ACTION_MARK,
+	__MLX5_DEVLINK_CONGESTION_ACTION_MAX,
+	MLX5_DEVLINK_CONGESTION_ACTION_MAX = __MLX5_DEVLINK_CONGESTION_ACTION_MAX - 1,
+};
+
+enum {
+	MLX5_DEVLINK_CONGESTION_MODE_AGGRESSIVE,
+	MLX5_DEVLINK_CONGESTION_MODE_DYNAMIC_ADJUSTMENT,
+	__MLX5_DEVLINK_CONGESTION_MODE_MAX,
+	MLX5_DEVLINK_CONGESTION_MODE_MAX = __MLX5_DEVLINK_CONGESTION_MODE_MAX - 1,
+};
+
+static int mlx5_devlink_set_mpegc(struct mlx5_core_dev *mdev, u32 *in,
+				  int size_in)
+{
+	u32 out[MLX5_ST_SZ_DW(mpegc_reg)] = {0};
+
+	if (!MLX5_CAP_MCAM_REG(mdev, mpegc))
+		return -EOPNOTSUPP;
+
+	return mlx5_core_access_reg(mdev, in, size_in, out,
+				    sizeof(out), MLX5_REG_MPEGC, 0, 1);
+}
+
+static int mlx5_devlink_set_tx_lossy_overflow(struct mlx5_core_dev *mdev,
+					      u8 tx_lossy_overflow)
+{
+	u32 in[MLX5_ST_SZ_DW(mpegc_reg)] = {0};
+	u8 field_select = 0;
+
+	if (tx_lossy_overflow == MLX5_DEVLINK_CONGESTION_ACTION_MARK) {
+		if (MLX5_CAP_MCAM_FEATURE(mdev, mark_tx_action_cqe))
+			field_select |=
+				MLX5_DEVLINK_MPEGC_FIELD_SELECT_MARK_TX_ACTION_CQE;
+
+		if (MLX5_CAP_MCAM_FEATURE(mdev, mark_tx_action_cnp))
+			field_select |=
+				MLX5_DEVLINK_MPEGC_FIELD_SELECT_MARK_TX_ACTION_CNP;
+
+		if (!field_select)
+			return -EOPNOTSUPP;
+	}
+
+	MLX5_SET(mpegc_reg, in, field_select,
+		 field_select |
+		 MLX5_DEVLINK_MPEGC_FIELD_SELECT_TX_OVERFLOW_DROP_EN);
+	MLX5_SET(mpegc_reg, in, tx_lossy_overflow_oper, tx_lossy_overflow);
+	MLX5_SET(mpegc_reg, in, mark_cqe, 0x1);
+	MLX5_SET(mpegc_reg, in, mark_cnp, 0x1);
+
+	return mlx5_devlink_set_mpegc(mdev, in, sizeof(in));
+}
+
+static int mlx5_devlink_set_tx_overflow_sense(struct mlx5_core_dev *mdev,
+					      u8 tx_overflow_sense)
+{
+	u32 in[MLX5_ST_SZ_DW(mpegc_reg)] = {0};
+
+	if (!MLX5_CAP_MCAM_FEATURE(mdev, dynamic_tx_overflow))
+		return -EOPNOTSUPP;
+
+	MLX5_SET(mpegc_reg, in, field_select,
+		 MLX5_DEVLINK_MPEGC_FIELD_SELECT_TX_OVERFLOW_SENSE);
+	MLX5_SET(mpegc_reg, in, tx_overflow_sense, tx_overflow_sense);
+
+	return mlx5_devlink_set_mpegc(mdev, in, sizeof(in));
+}
+
+static int mlx5_devlink_query_mpegc(struct mlx5_core_dev *mdev, u32 *out,
+				    int size_out)
+{
+	u32 in[MLX5_ST_SZ_DW(mpegc_reg)] = {0};
+
+	if (!MLX5_CAP_MCAM_REG(mdev, mpegc))
+		return -EOPNOTSUPP;
+
+	return mlx5_core_access_reg(mdev, in, sizeof(in), out,
+				    size_out, MLX5_REG_MPEGC, 0, 0);
+}
+
+static int mlx5_devlink_query_tx_lossy_overflow(struct mlx5_core_dev *mdev,
+						u8 *tx_lossy_overflow)
+{
+	u32 out[MLX5_ST_SZ_DW(mpegc_reg)] = {0};
+	int err;
+
+	err = mlx5_devlink_query_mpegc(mdev, out, sizeof(out));
+	if (err)
+		return err;
+
+	*tx_lossy_overflow = MLX5_GET(mpegc_reg, out, tx_lossy_overflow_oper);
+
+	return 0;
+}
+
+static int mlx5_devlink_query_tx_overflow_sense(struct mlx5_core_dev *mdev,
+						u8 *tx_overflow_sense)
+{
+	u32 out[MLX5_ST_SZ_DW(mpegc_reg)] = {0};
+	int err;
+
+	if (!MLX5_CAP_MCAM_FEATURE(mdev, dynamic_tx_overflow))
+		return -EOPNOTSUPP;
+
+	err = mlx5_devlink_query_mpegc(mdev, out, sizeof(out));
+	if (err)
+		return err;
+
+	*tx_overflow_sense = MLX5_GET(mpegc_reg, out, tx_overflow_sense);
+
+	return 0;
+}
+
 int mlx5_devlink_register(struct devlink *devlink, struct device *dev)
 {
 	return devlink_register(devlink, dev);
diff --git a/drivers/net/ethernet/mellanox/mlx5/core/devlink.h b/drivers/net/ethernet/mellanox/mlx5/core/devlink.h
index 455bfa4e89c0..cdf09df8293f 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/devlink.h
+++ b/drivers/net/ethernet/mellanox/mlx5/core/devlink.h
@@ -5,6 +5,7 @@
 #define __MLX5_DEVLINK_H__
 
 #include <net/devlink.h>
+#include <linux/mlx5/driver.h>
 
 int mlx5_devlink_register(struct devlink *devlink, struct device *dev);
 void mlx5_devlink_unregister(struct devlink *devlink);
-- 
2.17.0