[PATCH v3 05/36] net/intel: create separate header for Tx scalar fns

[Loftus, Ciara]

> Subject: [PATCH v3 05/36] net/intel: create separate header for Tx scalar fns
> 
> Rather than having all Tx code in the one file, which could start
> getting rather long, move the scalar datapath functions to a new header
> file.
> 
> Signed-off-by: Bruce Richardson <bruce.richardson at intel.com>
> ---
>  drivers/net/intel/common/tx.h            | 58 ++------------------
>  drivers/net/intel/common/tx_scalar_fns.h | 67
> ++++++++++++++++++++++++
>  2 files changed, 72 insertions(+), 53 deletions(-)
>  create mode 100644 drivers/net/intel/common/tx_scalar_fns.h

Why not create the file when ci_tx_xmit_cleanup was first introduced?
I prefer the naming tx_scalar.h but keep tx_scalar_fns.h if you feel it's better.

> 
> diff --git a/drivers/net/intel/common/tx.h b/drivers/net/intel/common/tx.h
> index 03245d4fba..01e42303b4 100644
> --- a/drivers/net/intel/common/tx.h
> +++ b/drivers/net/intel/common/tx.h
> @@ -319,59 +319,6 @@ ci_tx_free_bufs_vec(struct ci_tx_queue *txq,
> ci_desc_done_fn desc_done, bool ctx
>  	return txq->tx_rs_thresh;
>  }
> 
> -/*
> - * Common transmit descriptor cleanup function for Intel drivers.
> - * Used by ice, i40e, iavf, and idpf drivers.
> - *
> - * Returns:
> - *   0 on success
> - *  -1 if cleanup cannot proceed (descriptors not yet processed by HW)
> - */
> -static __rte_always_inline int
> -ci_tx_xmit_cleanup(struct ci_tx_queue *txq)
> -{
> -	struct ci_tx_entry *sw_ring = txq->sw_ring;
> -	volatile struct ci_tx_desc *txd = txq->ci_tx_ring;
> -	uint16_t last_desc_cleaned = txq->last_desc_cleaned;
> -	uint16_t nb_tx_desc = txq->nb_tx_desc;
> -	uint16_t desc_to_clean_to;
> -	uint16_t nb_tx_to_clean;
> -
> -	/* Determine the last descriptor needing to be cleaned */
> -	desc_to_clean_to = (uint16_t)(last_desc_cleaned + txq->tx_rs_thresh);
> -	if (desc_to_clean_to >= nb_tx_desc)
> -		desc_to_clean_to = (uint16_t)(desc_to_clean_to -
> nb_tx_desc);
> -
> -	/* Check to make sure the last descriptor to clean is done */
> -	desc_to_clean_to = sw_ring[desc_to_clean_to].last_id;
> -
> -	/* Check if descriptor is done - all drivers use 0xF as done value in bits
> 3:0 */
> -	if ((txd[desc_to_clean_to].cmd_type_offset_bsz &
> rte_cpu_to_le_64(CI_TXD_QW1_DTYPE_M)) !=
> -			rte_cpu_to_le_64(CI_TX_DESC_DTYPE_DESC_DONE))
> {
> -		/* Descriptor not yet processed by hardware */
> -		return -1;
> -	}
> -
> -	/* Figure out how many descriptors will be cleaned */
> -	if (last_desc_cleaned > desc_to_clean_to)
> -		nb_tx_to_clean = (uint16_t)((nb_tx_desc - last_desc_cleaned)
> + desc_to_clean_to);
> -	else
> -		nb_tx_to_clean = (uint16_t)(desc_to_clean_to -
> last_desc_cleaned);
> -
> -	/* The last descriptor to clean is done, so that means all the
> -	 * descriptors from the last descriptor that was cleaned
> -	 * up to the last descriptor with the RS bit set
> -	 * are done. Only reset the threshold descriptor.
> -	 */
> -	txd[desc_to_clean_to].cmd_type_offset_bsz = 0;
> -
> -	/* Update the txq to reflect the last descriptor that was cleaned */
> -	txq->last_desc_cleaned = desc_to_clean_to;
> -	txq->nb_tx_free = (uint16_t)(txq->nb_tx_free + nb_tx_to_clean);
> -
> -	return 0;
> -}
> -
>  static inline void
>  ci_txq_release_all_mbufs(struct ci_tx_queue *txq, bool use_ctx)
>  {
> @@ -490,4 +437,9 @@ ci_tx_path_select(const struct ci_tx_path_features
> *req_features,
>  	return idx;
>  }
> 
> +/* include the scalar functions at the end, so they can use the common
> definitions.
> + * This is done so drivers can use all functions just by including tx.h
> + */
> +#include "tx_scalar_fns.h"
> +
>  #endif /* _COMMON_INTEL_TX_H_ */
> diff --git a/drivers/net/intel/common/tx_scalar_fns.h
> b/drivers/net/intel/common/tx_scalar_fns.h
> new file mode 100644
> index 0000000000..c79210d084
> --- /dev/null
> +++ b/drivers/net/intel/common/tx_scalar_fns.h
> @@ -0,0 +1,67 @@
> +/* SPDX-License-Identifier: BSD-3-Clause
> + * Copyright(c) 2025 Intel Corporation

Should this be 2026?

> + */
> +
> +#ifndef _COMMON_INTEL_TX_SCALAR_FNS_H_
> +#define _COMMON_INTEL_TX_SCALAR_FNS_H_
> +
> +#include <stdint.h>
> +#include <rte_byteorder.h>
> +
> +/* depends on common Tx definitions. */
> +#include "tx.h"
> +
> +/*
> + * Common transmit descriptor cleanup function for Intel drivers.
> + * Used by ice, i40e, iavf, and idpf drivers.

Do we need to call out the driver names in the comment? If a new driver
were to adopt this function they would need to patch this file too to
update the comment.

> + *
> + * Returns:
> + *   0 on success
> + *  -1 if cleanup cannot proceed (descriptors not yet processed by HW)
> + */
> +static __rte_always_inline int
> +ci_tx_xmit_cleanup(struct ci_tx_queue *txq)
> +{
> +	struct ci_tx_entry *sw_ring = txq->sw_ring;
> +	volatile struct ci_tx_desc *txd = txq->ci_tx_ring;
> +	uint16_t last_desc_cleaned = txq->last_desc_cleaned;
> +	uint16_t nb_tx_desc = txq->nb_tx_desc;
> +	uint16_t desc_to_clean_to;
> +	uint16_t nb_tx_to_clean;
> +
> +	/* Determine the last descriptor needing to be cleaned */
> +	desc_to_clean_to = (uint16_t)(last_desc_cleaned + txq->tx_rs_thresh);
> +	if (desc_to_clean_to >= nb_tx_desc)
> +		desc_to_clean_to = (uint16_t)(desc_to_clean_to -
> nb_tx_desc);
> +
> +	/* Check to make sure the last descriptor to clean is done */
> +	desc_to_clean_to = sw_ring[desc_to_clean_to].last_id;
> +
> +	/* Check if descriptor is done - all drivers use 0xF as done value in bits
> 3:0 */
> +	if ((txd[desc_to_clean_to].cmd_type_offset_bsz &
> rte_cpu_to_le_64(CI_TXD_QW1_DTYPE_M)) !=
> +			rte_cpu_to_le_64(CI_TX_DESC_DTYPE_DESC_DONE))
> {
> +		/* Descriptor not yet processed by hardware */
> +		return -1;
> +	}
> +
> +	/* Figure out how many descriptors will be cleaned */
> +	if (last_desc_cleaned > desc_to_clean_to)
> +		nb_tx_to_clean = (uint16_t)((nb_tx_desc - last_desc_cleaned)
> + desc_to_clean_to);
> +	else
> +		nb_tx_to_clean = (uint16_t)(desc_to_clean_to -
> last_desc_cleaned);
> +
> +	/* The last descriptor to clean is done, so that means all the
> +	 * descriptors from the last descriptor that was cleaned
> +	 * up to the last descriptor with the RS bit set
> +	 * are done. Only reset the threshold descriptor.
> +	 */
> +	txd[desc_to_clean_to].cmd_type_offset_bsz = 0;
> +
> +	/* Update the txq to reflect the last descriptor that was cleaned */
> +	txq->last_desc_cleaned = desc_to_clean_to;
> +	txq->nb_tx_free = (uint16_t)(txq->nb_tx_free + nb_tx_to_clean);
> +
> +	return 0;
> +}
> +
> +#endif /* _COMMON_INTEL_TX_SCALAR_FNS_H_ */
> --
> 2.51.0