Re: [PATCH net-next v5 10/14] net: ethernet: qualcomm: Initialize PPE RSS hash settings

[Konrad Dybcio <konrad.dybcio@oss.qualcomm.com>]

On 6/26/25 4:31 PM, Luo Jie wrote:
> The PPE RSS hash is generated during PPE receive, based on the packet
> content (3 tuples or 5 tuples) and as per the configured RSS seed. The
> hash is then used to select the queue to transmit the packet to the
> ARM CPU.
> 
> This patch initializes the RSS hash settings that are used to generate
> the hash for the packet during PPE packet receive.
> 
> Signed-off-by: Luo Jie <quic_luoj@quicinc.com>
> ---
>  drivers/net/ethernet/qualcomm/ppe/ppe_config.c | 194 ++++++++++++++++++++++++-
>  drivers/net/ethernet/qualcomm/ppe/ppe_config.h |  39 +++++
>  drivers/net/ethernet/qualcomm/ppe/ppe_regs.h   |  40 +++++
>  3 files changed, 272 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/net/ethernet/qualcomm/ppe/ppe_config.c b/drivers/net/ethernet/qualcomm/ppe/ppe_config.c
> index dd7a4949f049..3b290eda7633 100644
> --- a/drivers/net/ethernet/qualcomm/ppe/ppe_config.c
> +++ b/drivers/net/ethernet/qualcomm/ppe/ppe_config.c
> @@ -1216,6 +1216,143 @@ int ppe_counter_enable_set(struct ppe_device *ppe_dev, int port)
>  	return regmap_set_bits(ppe_dev->regmap, reg, PPE_PORT_EG_VLAN_TBL_TX_COUNTING_EN);
>  }
>  
> +static int ppe_rss_hash_ipv4_config(struct ppe_device *ppe_dev, int index,
> +				    struct ppe_rss_hash_cfg cfg)
> +{
> +	u32 reg, val;
> +
> +	switch (index) {
> +	case 0:
> +		val = FIELD_PREP(PPE_RSS_HASH_MIX_IPV4_VAL, cfg.hash_sip_mix[0]);
> +		break;
> +	case 1:
> +		val = FIELD_PREP(PPE_RSS_HASH_MIX_IPV4_VAL, cfg.hash_dip_mix[0]);
> +		break;
> +	case 2:
> +		val = FIELD_PREP(PPE_RSS_HASH_MIX_IPV4_VAL, cfg.hash_protocol_mix);
> +		break;
> +	case 3:
> +		val = FIELD_PREP(PPE_RSS_HASH_MIX_IPV4_VAL, cfg.hash_dport_mix);
> +		break;
> +	case 4:
> +		val = FIELD_PREP(PPE_RSS_HASH_MIX_IPV4_VAL, cfg.hash_sport_mix);
> +		break;
> +	default:
> +		return -EINVAL;
> +	}
> +
> +	reg = PPE_RSS_HASH_MIX_IPV4_ADDR + index * PPE_RSS_HASH_MIX_IPV4_INC;
> +
> +	return regmap_write(ppe_dev->regmap, reg, val);

FWIW you can assign the value in the switch statement and only FIELD_PREP
it in the regmap_write, since the bitfield is the same

Konrad