net/mlx5: SD, Introduce SD lib

Add Socket-Direct API with empty/minimal implementation.
We fill-in the implementation gradually in downstream patches.
Signed-off-by: Tariq Toukan <tariqt@nvidia.com>
Reviewed-by: Gal Pressman <gal@nvidia.com>
Signed-off-by: Saeed Mahameed <saeedm@nvidia.com>

drivers/net/ethernet/mellanox/mlx5/core/Makefile

@@ -29,7 +29,7 @@ mlx5_core-$(CONFIG_MLX5_CORE_EN) += en/rqt.o en/tir.o en/rss.o en/rx_res.o \
 		en/reporter_tx.o en/reporter_rx.o en/params.o en/xsk/pool.o \
 		en/xsk/setup.o en/xsk/rx.o en/xsk/tx.o en/devlink.o en/ptp.o \
 		en/qos.o en/htb.o en/trap.o en/fs_tt_redirect.o en/selq.o \
-		lib/crypto.o
+		lib/crypto.o lib/sd.o
 
 #
 # Netdev extra

drivers/net/ethernet/mellanox/mlx5/core/lib/mlx5.h

@@ -54,4 +54,15 @@ static inline struct net_device *mlx5_uplink_netdev_get(struct mlx5_core_dev *md
 {
 	return mdev->mlx5e_res.uplink_netdev;
 }
+
+struct mlx5_sd;
+
+static inline struct mlx5_sd *mlx5_get_sd(struct mlx5_core_dev *dev)
+{
+	return NULL;
+}
+
+static inline void mlx5_set_sd(struct mlx5_core_dev *dev, struct mlx5_sd *sd)
+{
+}
 #endif

drivers/net/ethernet/mellanox/mlx5/core/lib/sd.c

+// SPDX-License-Identifier: GPL-2.0 OR Linux-OpenIB
+/* Copyright (c) 2023, NVIDIA CORPORATION & AFFILIATES. All rights reserved. */
+
+#include "lib/sd.h"
+#include "mlx5_core.h"
+
+#define sd_info(__dev, format, ...) \
+	dev_info((__dev)->device, "Socket-Direct: " format, ##__VA_ARGS__)
+#define sd_warn(__dev, format, ...) \
+	dev_warn((__dev)->device, "Socket-Direct: " format, ##__VA_ARGS__)
+
+struct mlx5_sd {
+};
+
+static int mlx5_sd_get_host_buses(struct mlx5_core_dev *dev)
+{
+	return 1;
+}
+
+struct mlx5_core_dev *
+mlx5_sd_primary_get_peer(struct mlx5_core_dev *primary, int idx)
+{
+	if (idx == 0)
+		return primary;
+
+	return NULL;
+}
+
+int mlx5_sd_ch_ix_get_dev_ix(struct mlx5_core_dev *dev, int ch_ix)
+{
+	return ch_ix % mlx5_sd_get_host_buses(dev);
+}
+
+int mlx5_sd_ch_ix_get_vec_ix(struct mlx5_core_dev *dev, int ch_ix)
+{
+	return ch_ix / mlx5_sd_get_host_buses(dev);
+}
+
+struct mlx5_core_dev *mlx5_sd_ch_ix_get_dev(struct mlx5_core_dev *primary, int ch_ix)
+{
+	int mdev_idx = mlx5_sd_ch_ix_get_dev_ix(primary, ch_ix);
+
+	return mlx5_sd_primary_get_peer(primary, mdev_idx);
+}
+
+int mlx5_sd_init(struct mlx5_core_dev *dev)
+{
+	return 0;
+}
+
+void mlx5_sd_cleanup(struct mlx5_core_dev *dev)
+{
+}
+
+struct auxiliary_device *mlx5_sd_get_adev(struct mlx5_core_dev *dev,
+					  struct auxiliary_device *adev,
+					  int idx)
+{
+	return adev;
+}

drivers/net/ethernet/mellanox/mlx5/core/lib/sd.h

+/* SPDX-License-Identifier: GPL-2.0 OR Linux-OpenIB */
+/* Copyright (c) 2023, NVIDIA CORPORATION & AFFILIATES. All rights reserved. */
+
+#ifndef __MLX5_LIB_SD_H__
+#define __MLX5_LIB_SD_H__
+
+#define MLX5_SD_MAX_GROUP_SZ 2
+
+struct mlx5_sd;
+
+struct mlx5_core_dev *mlx5_sd_primary_get_peer(struct mlx5_core_dev *primary, int idx);
+int mlx5_sd_ch_ix_get_dev_ix(struct mlx5_core_dev *dev, int ch_ix);
+int mlx5_sd_ch_ix_get_vec_ix(struct mlx5_core_dev *dev, int ch_ix);
+struct mlx5_core_dev *mlx5_sd_ch_ix_get_dev(struct mlx5_core_dev *primary, int ch_ix);
+struct auxiliary_device *mlx5_sd_get_adev(struct mlx5_core_dev *dev,
+					  struct auxiliary_device *adev,
+					  int idx);
+
+int mlx5_sd_init(struct mlx5_core_dev *dev);
+void mlx5_sd_cleanup(struct mlx5_core_dev *dev);
+
+#define mlx5_sd_for_each_dev_from_to(i, primary, ix_from, to, pos)	\
+	for (i = ix_from;							\
+	     (pos = mlx5_sd_primary_get_peer(primary, i)) && pos != (to); i++)
+
+#define mlx5_sd_for_each_dev(i, primary, pos)				\
+	mlx5_sd_for_each_dev_from_to(i, primary, 0, NULL, pos)
+
+#define mlx5_sd_for_each_dev_to(i, primary, to, pos)			\
+	mlx5_sd_for_each_dev_from_to(i, primary, 0, to, pos)
+
+#define mlx5_sd_for_each_secondary(i, primary, pos)			\
+	mlx5_sd_for_each_dev_from_to(i, primary, 1, NULL, pos)
+
+#define mlx5_sd_for_each_secondary_to(i, primary, to, pos)		\
+	mlx5_sd_for_each_dev_from_to(i, primary, 1, to, pos)
+
+#endif /* __MLX5_LIB_SD_H__ */