mlxsw: spectrum_buffers: Get max_buff defaults into limits exposed to user

Although the device supports max_buff magic values 0 and 0xff, these are
not exposed to the user via devlink.
Therefore, adjust the default values to be within configurable range.
Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Reviewed-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/mellanox/mlxsw/reg.h

@@ -3566,6 +3566,10 @@ MLXSW_ITEM32(reg, sbcm, dir, 0x00, 0, 2);
  */
 MLXSW_ITEM32(reg, sbcm, min_buff, 0x18, 0, 24);
 
+/* shared max_buff limits for dynamic threshold for SBCM, SBPM */
+#define MLXSW_REG_SBXX_DYN_MAX_BUFF_MIN 1
+#define MLXSW_REG_SBXX_DYN_MAX_BUFF_MAX 14
+
 /* reg_sbcm_max_buff
  * When the pool associated to the port-pg/tclass is configured to
  * static, Maximum buffer size for the limiter configured in cells.

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

@@ -255,13 +255,13 @@ static int mlxsw_sp_sb_prs_init(struct mlxsw_sp *mlxsw_sp)
 
 static const struct mlxsw_sp_sb_cm mlxsw_sp_sb_cms_ingress[] = {
 	MLXSW_SP_SB_CM(MLXSW_SP_BYTES_TO_CELLS(10000), 8, 0),
-	MLXSW_SP_SB_CM(0, 0, 0),
-	MLXSW_SP_SB_CM(0, 0, 0),
-	MLXSW_SP_SB_CM(0, 0, 0),
-	MLXSW_SP_SB_CM(0, 0, 0),
-	MLXSW_SP_SB_CM(0, 0, 0),
-	MLXSW_SP_SB_CM(0, 0, 0),
-	MLXSW_SP_SB_CM(0, 0, 0),
+	MLXSW_SP_SB_CM(0, MLXSW_REG_SBXX_DYN_MAX_BUFF_MIN, 0),
+	MLXSW_SP_SB_CM(0, MLXSW_REG_SBXX_DYN_MAX_BUFF_MIN, 0),
+	MLXSW_SP_SB_CM(0, MLXSW_REG_SBXX_DYN_MAX_BUFF_MIN, 0),
+	MLXSW_SP_SB_CM(0, MLXSW_REG_SBXX_DYN_MAX_BUFF_MIN, 0),
+	MLXSW_SP_SB_CM(0, MLXSW_REG_SBXX_DYN_MAX_BUFF_MIN, 0),
+	MLXSW_SP_SB_CM(0, MLXSW_REG_SBXX_DYN_MAX_BUFF_MIN, 0),
+	MLXSW_SP_SB_CM(0, MLXSW_REG_SBXX_DYN_MAX_BUFF_MIN, 0),
 	MLXSW_SP_SB_CM(0, 0, 0), /* dummy, this PG does not exist */
 	MLXSW_SP_SB_CM(MLXSW_SP_BYTES_TO_CELLS(20000), 1, 3),
 };
@@ -385,19 +385,19 @@ static int mlxsw_sp_cpu_port_sb_cms_init(struct mlxsw_sp *mlxsw_sp)
 	}
 
 static const struct mlxsw_sp_sb_pm mlxsw_sp_sb_pms_ingress[] = {
-	MLXSW_SP_SB_PM(0, 0xff),
-	MLXSW_SP_SB_PM(0, 0),
-	MLXSW_SP_SB_PM(0, 0),
-	MLXSW_SP_SB_PM(0, 0xff),
+	MLXSW_SP_SB_PM(0, MLXSW_REG_SBXX_DYN_MAX_BUFF_MAX),
+	MLXSW_SP_SB_PM(0, MLXSW_REG_SBXX_DYN_MAX_BUFF_MIN),
+	MLXSW_SP_SB_PM(0, MLXSW_REG_SBXX_DYN_MAX_BUFF_MIN),
+	MLXSW_SP_SB_PM(0, MLXSW_REG_SBXX_DYN_MAX_BUFF_MAX),
 };
 
 #define MLXSW_SP_SB_PMS_INGRESS_LEN ARRAY_SIZE(mlxsw_sp_sb_pms_ingress)
 
 static const struct mlxsw_sp_sb_pm mlxsw_sp_sb_pms_egress[] = {
 	MLXSW_SP_SB_PM(0, 7),
-	MLXSW_SP_SB_PM(0, 0),
-	MLXSW_SP_SB_PM(0, 0),
-	MLXSW_SP_SB_PM(0, 0),
+	MLXSW_SP_SB_PM(0, MLXSW_REG_SBXX_DYN_MAX_BUFF_MIN),
+	MLXSW_SP_SB_PM(0, MLXSW_REG_SBXX_DYN_MAX_BUFF_MIN),
+	MLXSW_SP_SB_PM(0, MLXSW_REG_SBXX_DYN_MAX_BUFF_MIN),
 };
 
 #define MLXSW_SP_SB_PMS_EGRESS_LEN ARRAY_SIZE(mlxsw_sp_sb_pms_egress)