mlxsw: spectrum_buffers: Allow configuration of static pools

Some pools configured through the sb_pm entries may have by default
static size. The MC pool is now not explicitly configured, however it
gets configured as static implicitly by 0-initializing sb->prs, and a
follow-up patch adds an explicit configuration to the same effect.

To support this, pass max_buff taken from sb_pm and sb_cm entries
through cell conversion before handing it to mlxsw_sp_sb_pm_write(), if
the pool that the sb_pm entry configures is statically-sized.

To keep current behavior, update mlxsw_sp_sb_cms_egress[] to denote
buffer sizes in bytes (assuming Spectrum 1 cell sizes, which the
original code assumed as well) instead of cells. Note that a follow-up
patch changes this to infinite size.

Also tweak a comment at SBMM configuration to remain true now that
statically-sized pools exist.
Signed-off-by: Petr Machata <petrm@mellanox.com>
Reviewed-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

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

@@ -380,14 +380,14 @@ static const struct mlxsw_sp_sb_cm mlxsw_sp_sb_cms_egress[] = {
 	MLXSW_SP_SB_CM(1500, 9, 4),
 	MLXSW_SP_SB_CM(1500, 9, 4),
 	MLXSW_SP_SB_CM(1500, 9, 4),
-	MLXSW_SP_SB_CM(0, 140000, 8),
-	MLXSW_SP_SB_CM(0, 140000, 8),
-	MLXSW_SP_SB_CM(0, 140000, 8),
-	MLXSW_SP_SB_CM(0, 140000, 8),
-	MLXSW_SP_SB_CM(0, 140000, 8),
-	MLXSW_SP_SB_CM(0, 140000, 8),
-	MLXSW_SP_SB_CM(0, 140000, 8),
-	MLXSW_SP_SB_CM(0, 140000, 8),
+	MLXSW_SP_SB_CM(0, 13440000, 8),
+	MLXSW_SP_SB_CM(0, 13440000, 8),
+	MLXSW_SP_SB_CM(0, 13440000, 8),
+	MLXSW_SP_SB_CM(0, 13440000, 8),
+	MLXSW_SP_SB_CM(0, 13440000, 8),
+	MLXSW_SP_SB_CM(0, 13440000, 8),
+	MLXSW_SP_SB_CM(0, 13440000, 8),
+	MLXSW_SP_SB_CM(0, 13440000, 8),
 	MLXSW_SP_SB_CM(1, 0xff, 4),
 };
 
@@ -433,6 +433,14 @@ static const struct mlxsw_sp_sb_cm mlxsw_sp_cpu_port_sb_cms[] = {
 #define MLXSW_SP_CPU_PORT_SB_MCS_LEN \
 	ARRAY_SIZE(mlxsw_sp_cpu_port_sb_cms)
 
+static bool
+mlxsw_sp_sb_pool_is_static(struct mlxsw_sp *mlxsw_sp, u16 pool_index)
+{
+	struct mlxsw_sp_sb_pr *pr = mlxsw_sp_sb_pr_get(mlxsw_sp, pool_index);
+
+	return pr->mode == MLXSW_REG_SBPR_MODE_STATIC;
+}
+
 static int __mlxsw_sp_sb_cms_init(struct mlxsw_sp *mlxsw_sp, u8 local_port,
 				  enum mlxsw_reg_sbxx_dir dir,
 				  const struct mlxsw_sp_sb_cm *cms,
@@ -444,6 +452,7 @@ static int __mlxsw_sp_sb_cms_init(struct mlxsw_sp *mlxsw_sp, u8 local_port,
 	for (i = 0; i < cms_len; i++) {
 		const struct mlxsw_sp_sb_cm *cm;
 		u32 min_buff;
+		u32 max_buff;
 
 		if (i == 8 && dir == MLXSW_REG_SBXX_DIR_INGRESS)
 			continue; /* PG number 8 does not exist, skip it */
@@ -451,18 +460,21 @@ static int __mlxsw_sp_sb_cms_init(struct mlxsw_sp *mlxsw_sp, u8 local_port,
 		if (WARN_ON(mlxsw_sp_sb_pool_dess[cm->pool_index].dir != dir))
 			continue;
 
-		/* All pools are initialized using dynamic thresholds,
-		 * therefore 'max_buff' isn't specified in cells.
-		 */
 		min_buff = mlxsw_sp_bytes_cells(mlxsw_sp, cm->min_buff);
-		if (cm->max_buff == MLXSW_SP_SB_INFI)
+		max_buff = cm->max_buff;
+		if (max_buff == MLXSW_SP_SB_INFI) {
 			err = mlxsw_sp_sb_cm_write(mlxsw_sp, local_port, i,
 						   min_buff, 0,
 						   true, cm->pool_index);
-		else
+		} else {
+			if (mlxsw_sp_sb_pool_is_static(mlxsw_sp,
+						       cm->pool_index))
+				max_buff = mlxsw_sp_bytes_cells(mlxsw_sp,
+								max_buff);
 			err = mlxsw_sp_sb_cm_write(mlxsw_sp, local_port, i,
-						   min_buff, cm->max_buff,
+						   min_buff, max_buff,
 						   false, cm->pool_index);
+		}
 		if (err)
 			return err;
 	}
@@ -523,11 +535,15 @@ static int mlxsw_sp_port_sb_pms_init(struct mlxsw_sp_port *mlxsw_sp_port)
 
 	for (i = 0; i < MLXSW_SP_SB_PMS_LEN; i++) {
 		const struct mlxsw_sp_sb_pm *pm = &mlxsw_sp_sb_pms[i];
+		u32 max_buff;
 		u32 min_buff;
 
 		min_buff = mlxsw_sp_bytes_cells(mlxsw_sp, pm->min_buff);
+		max_buff = pm->max_buff;
+		if (mlxsw_sp_sb_pool_is_static(mlxsw_sp, i))
+			max_buff = mlxsw_sp_bytes_cells(mlxsw_sp, max_buff);
 		err = mlxsw_sp_sb_pm_write(mlxsw_sp, mlxsw_sp_port->local_port,
-					   i, min_buff, pm->max_buff);
+					   i, min_buff, max_buff);
 		if (err)
 			return err;
 	}
@@ -580,8 +596,8 @@ static int mlxsw_sp_sb_mms_init(struct mlxsw_sp *mlxsw_sp)
 
 		mc = &mlxsw_sp_sb_mms[i];
 		des = &mlxsw_sp_sb_pool_dess[mc->pool_index];
-		/* All pools are initialized using dynamic thresholds,
-		 * therefore 'max_buff' isn't specified in cells.
+		/* All pools used by sb_mm's are initialized using dynamic
+		 * thresholds, therefore 'max_buff' isn't specified in cells.
 		 */
 		min_buff = mlxsw_sp_bytes_cells(mlxsw_sp, mc->min_buff);
 		mlxsw_reg_sbmm_pack(sbmm_pl, i, min_buff, mc->max_buff,