Re: [PATCH iwl-next v10 02/14] ice: support Rx timestamp on flex descriptor

[Alexander Lobakin <aleksander.lobakin@intel.com>]

From: Wojciech Drewek <wojciech.drewek@intel.com>
Date: Wed, 21 Aug 2024 14:15:27 +0200

> From: Simei Su <simei.su@intel.com>
> 
> To support Rx timestamp offload, VIRTCHNL_OP_1588_PTP_CAPS is sent by
> the VF to request PTP capability and responded by the PF what capability
> is enabled for that VF.
> 
> Hardware captures timestamps which contain only 32 bits of nominal
> nanoseconds, as opposed to the 64bit timestamps that the stack expects.
> To convert 32b to 64b, we need a current PHC time.
> VIRTCHNL_OP_1588_PTP_GET_TIME is sent by the VF and responded by the
> PF with the current PHC time.

[...]

> diff --git a/drivers/net/ethernet/intel/ice/ice_vf_lib.h b/drivers/net/ethernet/intel/ice/ice_vf_lib.h
> index be4266899690..b7c340bb7aa7 100644
> --- a/drivers/net/ethernet/intel/ice/ice_vf_lib.h
> +++ b/drivers/net/ethernet/intel/ice/ice_vf_lib.h
> @@ -136,6 +136,8 @@ struct ice_vf {
>  	const struct ice_virtchnl_ops *virtchnl_ops;
>  	const struct ice_vf_ops *vf_ops;
>  
> +	u32 ptp_caps;

Hmm, there'll be a 4-byte hole here now.
If you put this new field either after ::mbx_info or after ::link_up,
the struct size won't change at all.

> +
>  	/* devlink port data */
>  	struct devlink_port devlink_port;
>  

[...]

> diff --git a/include/linux/avf/virtchnl.h b/include/linux/avf/virtchnl.h
> index 252fad21b04a..012ed2f5f9d0 100644
> --- a/include/linux/avf/virtchnl.h
> +++ b/include/linux/avf/virtchnl.h
> @@ -304,6 +304,18 @@ struct virtchnl_txq_info {
>  
>  VIRTCHNL_CHECK_STRUCT_LEN(24, virtchnl_txq_info);
>  
> +/* virtchnl_rxq_info_flags - definition of bits in the flags field of the
> + *			     virtchnl_rxq_info structure.
> + *
> + * @VIRTCHNL_PTP_RX_TSTAMP: request to enable Rx timestamping
> + *
> + * Other flag bits are currently * reserved and they may be extended in the

                                    ^

Just curious, what is this?

> + * future.
> + */
> +enum virtchnl_rxq_info_flags {
> +	VIRTCHNL_PTP_RX_TSTAMP = BIT(0),
> +};
> +
>  /* VIRTCHNL_OP_CONFIG_RX_QUEUE
>   * VF sends this message to set up parameters for one RX queue.
>   * External data buffer contains one instance of virtchnl_rxq_info.
> @@ -327,7 +339,8 @@ struct virtchnl_rxq_info {
>  	u32 max_pkt_size;
>  	u8 crc_disable;
>  	u8 rxdid;
> -	u8 pad1[2];
> +	enum virtchnl_rxq_info_flags flags:8; /* see virtchnl_rxq_info_flags */
> +	u8 pad1;
>  	u64 dma_ring_addr;
>  
>  	/* see enum virtchnl_rx_hsplit; deprecated with AVF 1.0 */

Thanks,
Olek