Subject: Re: [PATCH net-next v2 6/7] net: ethernet: ti: cpsw_ale: add helper to setup classifier defaults

From: Simon Horman <[email-masked]>
Date: Mon, 1 Jul 2024 08:35:05 +0100

On Fri, Jun 28, 2024 at 03:01:55PM +0300, Roger Quadros wrote:
> Default behaviour is to have 8 classifiers to map 8 DSCP/PCP
> priorities to N receive threads (flows). N depends on number of
> RX channels enabled for the port.
> 
> Signed-off-by: Roger Quadros <[email-masked]>
> ---
>  drivers/net/ethernet/ti/cpsw_ale.c | 57 ++++++++++++++++++++++++++++++++++++++
>  drivers/net/ethernet/ti/cpsw_ale.h |  1 +
>  2 files changed, 58 insertions(+)
> 
> diff --git a/drivers/net/ethernet/ti/cpsw_ale.c b/drivers/net/ethernet/ti/cpsw_ale.c
> index 75a17184d34c..51da527388df 100644
> --- a/drivers/net/ethernet/ti/cpsw_ale.c
> +++ b/drivers/net/ethernet/ti/cpsw_ale.c
> @@ -1650,3 +1650,60 @@ static void cpsw_ale_policer_thread_idx_enable(struct cpsw_ale *ale, u32 idx,
>  	regmap_field_write(ale->fields[ALE_THREAD_VALUE], thread_id);
>  	regmap_field_write(ale->fields[ALE_THREAD_ENABLE], enable ? 1 : 0);
>  }
> +
> +/* Disable all policer entries and thread mappings */
> +static void cpsw_ale_policer_reset(struct cpsw_ale *ale)
> +{
> +	int i;
> +
> +	for (i = 0; i < ale->params.num_policers ; i++) {
> +		cpsw_ale_policer_read_idx(ale, i);
> +		regmap_field_write(ale->fields[POL_PORT_MEN], 0);
> +		regmap_field_write(ale->fields[POL_PRI_MEN], 0);
> +		regmap_field_write(ale->fields[POL_OUI_MEN], 0);
> +		regmap_field_write(ale->fields[POL_DST_MEN], 0);
> +		regmap_field_write(ale->fields[POL_SRC_MEN], 0);
> +		regmap_field_write(ale->fields[POL_OVLAN_MEN], 0);
> +		regmap_field_write(ale->fields[POL_IVLAN_MEN], 0);
> +		regmap_field_write(ale->fields[POL_ETHERTYPE_MEN], 0);
> +		regmap_field_write(ale->fields[POL_IPSRC_MEN], 0);
> +		regmap_field_write(ale->fields[POL_IPDST_MEN], 0);
> +		regmap_field_write(ale->fields[POL_EN], 0);
> +		regmap_field_write(ale->fields[POL_RED_DROP_EN], 0);
> +		regmap_field_write(ale->fields[POL_YELLOW_DROP_EN], 0);
> +		regmap_field_write(ale->fields[POL_PRIORITY_THREAD_EN], 0);
> +
> +		cpsw_ale_policer_thread_idx_enable(ale, i, 0, 0);
> +	}
> +}
> +
> +/* Default classifer is to map 8 user priorities to N receive channels */
> +void cpsw_ale_classifier_setup_default(struct cpsw_ale *ale, int num_rx_ch)
> +{
> +	int pri, idx;
> +	int pri_thread_map[8][9] = {	{ 0, 0, 0, 0, 0, 0, 0, 0, },
> +					{ 0, 0, 0, 0, 1, 1, 1, 1, },
> +					{ 0, 0, 0, 0, 1, 1, 2, 2, },
> +					{ 1, 0, 0, 1, 2, 2, 3, 3, },
> +					{ 1, 0, 0, 1, 2, 3, 4, 4, },
> +					{ 1, 0, 0, 2, 3, 4, 5, 5, },
> +					{ 1, 0, 0, 2, 3, 4, 5, 6, },
> +					{ 2, 0, 1, 3, 4, 5, 6, 7, } };

Hi Roger,

Perhaps it is obvious, but I'm wondering if it is appropriate
to add a comment explaining the layout of the table, especially
the latter rows where the mapping of priority to receive channel
seems somewhat non-trivial.

> +
> +	cpsw_ale_policer_reset(ale);
> +
> +	/* use first 8 classifiers to map 8 (DSCP/PCP) priorities to channels */
> +	for (pri = 0; pri < 8; pri++) {
> +		idx = pri;
> +
> +		/* Classifier 'idx' match on priority 'pri' */
> +		cpsw_ale_policer_read_idx(ale, idx);
> +		regmap_field_write(ale->fields[POL_PRI_VAL], pri);
> +		regmap_field_write(ale->fields[POL_PRI_MEN], 1);
> +		cpsw_ale_policer_write_idx(ale, idx);
> +
> +		/* Map Classifier 'idx' to thread provided by the map */
> +		cpsw_ale_policer_thread_idx_enable(ale, idx,
> +						   pri_thread_map[num_rx_ch - 1][pri], 1);
> +	}
> +}
> diff --git a/drivers/net/ethernet/ti/cpsw_ale.h b/drivers/net/ethernet/ti/cpsw_ale.h
> index 2cb76acc6d16..1e4e9a3dd234 100644
> --- a/drivers/net/ethernet/ti/cpsw_ale.h
> +++ b/drivers/net/ethernet/ti/cpsw_ale.h
> @@ -193,5 +193,6 @@ int cpsw_ale_vlan_add_modify(struct cpsw_ale *ale, u16 vid, int port_mask,
>  int cpsw_ale_vlan_del_modify(struct cpsw_ale *ale, u16 vid, int port_mask);
>  void cpsw_ale_set_unreg_mcast(struct cpsw_ale *ale, int unreg_mcast_mask,
>  			      bool add);
> +void cpsw_ale_classifier_setup_default(struct cpsw_ale *ale, int num_rx_ch);
>  
>  #endif
> 
> -- 
> 2.34.1
> 
>