[v3,08/34] net/sfc: add MCDI wrappers for BCAM tables

  From: Denis Pryazhennikov <denis.pryazhennikov@arknetworks.am>

A "table" is structure used for lookups, consisting of a set of
entries which can be matched against an N-bit "request", to
return either a "hit" with an M-bit "response", or a "miss" if
there is no match. There are a number of HW tables of various
types that could be used in MAE.

In some types of table the entry may also be associated with an
N-bit "mask", allowing some bits of the request to be treated as
don't-care, and an integer "priority" to determine which entry is
used if more than one matches.

BCAM tables don't support "mask" and "priority", so the
corresponding fields must be zeroed.

Signed-off-by: Denis Pryazhennikov <denis.pryazhennikov@arknetworks.am>
Reviewed-by: Ivan Malov <ivan.malov@arknetworks.am>
Reviewed-by: Andy Moreton <amoreton@xilinx.com>
---
 drivers/net/sfc/sfc_tbls.h | 69 ++++++++++++++++++++++++++++++++++++++
 1 file changed, 69 insertions(+)
 create mode 100644 drivers/net/sfc/sfc_tbls.h
  

On 6/5/23 02:24, Ivan Malov wrote:
> From: Denis Pryazhennikov <denis.pryazhennikov@arknetworks.am>
> 
> A "table" is structure used for lookups, consisting of a set of
> entries which can be matched against an N-bit "request", to
> return either a "hit" with an M-bit "response", or a "miss" if
> there is no match. There are a number of HW tables of various
> types that could be used in MAE.
> 
> In some types of table the entry may also be associated with an
> N-bit "mask", allowing some bits of the request to be treated as
> don't-care, and an integer "priority" to determine which entry is
> used if more than one matches.
> 
> BCAM tables don't support "mask" and "priority", so the
> corresponding fields must be zeroed.
> 
> Signed-off-by: Denis Pryazhennikov <denis.pryazhennikov@arknetworks.am>
> Reviewed-by: Ivan Malov <ivan.malov@arknetworks.am>
> Reviewed-by: Andy Moreton <amoreton@xilinx.com>
> ---
>   drivers/net/sfc/sfc_tbls.h | 69 ++++++++++++++++++++++++++++++++++++++
>   1 file changed, 69 insertions(+)
>   create mode 100644 drivers/net/sfc/sfc_tbls.h
> 
> diff --git a/drivers/net/sfc/sfc_tbls.h b/drivers/net/sfc/sfc_tbls.h
> new file mode 100644
> index 0000000000..2a5c87b82c
> --- /dev/null
> +++ b/drivers/net/sfc/sfc_tbls.h
> @@ -0,0 +1,69 @@
> +/* SPDX-License-Identifier: BSD-3-Clause
> + *
> + * Copyright (c) 2023 Advanced Micro Devices, Inc.
> + */
> +
> +#ifndef _SFC_TBLS_H
> +#define _SFC_TBLS_H
> +
> +#include "efx.h"
> +
> +#ifdef __cplusplus
> +extern "C" {
> +#endif
> +
> +/**

Why is it Doxygen-style comment?

> + * Table types:
> + *   CAM - Content addressable memory
> + *  BCAM - Binary CAM
> + *  TCAM - Ternary CAM
> + * STCAM - Semi-ternary CAM
> + *
> + * Short description:
> + * TCAM:  Each entry has a key, mask, response and priority. An entry matches
> + *        when (key & mask) == (request & mask). In the case of multiple
> + *        matches, the entry with the highest priority wins; Each entry may
> + *        have its own mask, but TCAM table definitions may place constraints
> + *        on the possible masks allowed for each of the individual fields.
> + * STCAM: A limited form of TCAM in which only a limited number of masks and
> + *        associated priorities), up to some maximum fixed by the definition
> + *        of the table, may be in use at any one time.
> + * BCAM:  Each entry has only a key and response, with the whole request
> + *        matched against the key (like a typical hash table or "map").
> + * Direct (sometimes "DCAM", although it's not really content-addressable):
> + *        Essentially just an array, where the key bits are used simply as an
> + *        index.
> + */
> +
> +/* Priority is used only for TCAM or STCAM, use 0 in case of BCAM */
> +#define SFC_TBLS_BCAM_PRIORITY		0
> +
> +/* Mask ID is used only for STCAM with ALLOC_MASKS flag, use 0 for BCAM */
> +#define SFC_TBLS_BCAM_MASK_ID		0
> +
> +/* Mask is used only for STCAM */
> +#define SFC_TBLS_BCAM_MASK_WIDTH	0
> +
> +static inline int
> +sfc_tbls_bcam_entry_insert(efx_nic_t *enp, efx_table_id_t table_id, uint16_t key_width,
> +			   uint16_t resp_width, uint8_t *data, unsigned int data_size)
> +{
> +	return efx_table_entry_insert(enp, table_id, SFC_TBLS_BCAM_PRIORITY,
> +				      SFC_TBLS_BCAM_MASK_ID, key_width,
> +				      SFC_TBLS_BCAM_MASK_WIDTH, resp_width,
> +				      data, data_size);
> +}
> +
> +static inline int
> +sfc_tbls_bcam_entry_delete(efx_nic_t *enp, efx_table_id_t table_id, uint16_t key_width,
> +			   uint8_t *data, unsigned int data_size)
> +{
> +	return efx_table_entry_delete(enp, table_id, SFC_TBLS_BCAM_MASK_ID,
> +				      key_width, SFC_TBLS_BCAM_MASK_WIDTH,
> +				      data, data_size);
> +}
> +
> +#ifdef __cplusplus
> +}
> +#endif
> +#endif /* _SFC_TBLS_H */