mlxsw: spectrum_dcb: Implement dcbnl_setbuffer / getbuffer

Add dcbnl_setbuffer, which bounces requests if a headroom is in DCB mode.
Implement dcbnl_getbuffer such that it can always be used to determine
port-buffer configuration, regardless of headroom mode.

Signed-off-by: Petr Machata <petrm@nvidia.com>
Reviewed-by: Jiri Pirko <jiri@nvidia.com>
Signed-off-by: Ido Schimmel <idosch@nvidia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/mellanox/mlxsw/spectrum_dcb.c

@@ -592,6 +592,62 @@ err_port_pfc_set:
 	return err;
 }
 
+static int mlxsw_sp_dcbnl_getbuffer(struct net_device *dev, struct dcbnl_buffer *buf)
+{
+	struct mlxsw_sp_port *mlxsw_sp_port = netdev_priv(dev);
+	struct mlxsw_sp_hdroom *hdroom = mlxsw_sp_port->hdroom;
+	struct mlxsw_sp *mlxsw_sp = mlxsw_sp_port->mlxsw_sp;
+	int prio;
+	int i;
+
+	buf->total_size = 0;
+
+	BUILD_BUG_ON(DCBX_MAX_BUFFERS > MLXSW_SP_PB_COUNT);
+	for (i = 0; i < MLXSW_SP_PB_COUNT; i++) {
+		u32 bytes = mlxsw_sp_cells_bytes(mlxsw_sp, hdroom->bufs.buf[i].size_cells);
+
+		if (i < DCBX_MAX_BUFFERS)
+			buf->buffer_size[i] = bytes;
+		buf->total_size += bytes;
+	}
+
+	buf->total_size += mlxsw_sp_cells_bytes(mlxsw_sp, hdroom->int_buf.size_cells);
+
+	for (prio = 0; prio < IEEE_8021Q_MAX_PRIORITIES; prio++)
+		buf->prio2buffer[prio] = hdroom->prios.prio[prio].buf_idx;
+
+	return 0;
+}
+
+static int mlxsw_sp_dcbnl_setbuffer(struct net_device *dev, struct dcbnl_buffer *buf)
+{
+	struct mlxsw_sp_port *mlxsw_sp_port = netdev_priv(dev);
+	struct mlxsw_sp *mlxsw_sp = mlxsw_sp_port->mlxsw_sp;
+	struct mlxsw_sp_hdroom hdroom;
+	int prio;
+	int i;
+
+	hdroom = *mlxsw_sp_port->hdroom;
+
+	if (hdroom.mode != MLXSW_SP_HDROOM_MODE_TC) {
+		netdev_err(dev, "The use of dcbnl_setbuffer is only allowed if egress is configured using TC\n");
+		return -EINVAL;
+	}
+
+	for (prio = 0; prio < IEEE_8021Q_MAX_PRIORITIES; prio++)
+		hdroom.prios.prio[prio].set_buf_idx = buf->prio2buffer[prio];
+
+	BUILD_BUG_ON(DCBX_MAX_BUFFERS > MLXSW_SP_PB_COUNT);
+	for (i = 0; i < DCBX_MAX_BUFFERS; i++)
+		hdroom.bufs.buf[i].set_size_cells = mlxsw_sp_bytes_cells(mlxsw_sp,
+									 buf->buffer_size[i]);
+
+	mlxsw_sp_hdroom_prios_reset_buf_idx(&hdroom);
+	mlxsw_sp_hdroom_bufs_reset_lossiness(&hdroom);
+	mlxsw_sp_hdroom_bufs_reset_sizes(mlxsw_sp_port, &hdroom);
+	return mlxsw_sp_hdroom_configure(mlxsw_sp_port, &hdroom);
+}
+
 static const struct dcbnl_rtnl_ops mlxsw_sp_dcbnl_ops = {
 	.ieee_getets		= mlxsw_sp_dcbnl_ieee_getets,
 	.ieee_setets		= mlxsw_sp_dcbnl_ieee_setets,
@@ -604,6 +660,9 @@ static const struct dcbnl_rtnl_ops mlxsw_sp_dcbnl_ops = {
 
 	.getdcbx		= mlxsw_sp_dcbnl_getdcbx,
 	.setdcbx		= mlxsw_sp_dcbnl_setdcbx,
+
+	.dcbnl_getbuffer	= mlxsw_sp_dcbnl_getbuffer,
+	.dcbnl_setbuffer	= mlxsw_sp_dcbnl_setbuffer,
 };
 
 static int mlxsw_sp_port_ets_init(struct mlxsw_sp_port *mlxsw_sp_port)