Re: [Patch v2 net-next 1/7] octeontx2-af: forward error correction configuration

[Willem de Bruijn <willemdebruijn.kernel@gmail.com>]

On Wed, Jan 27, 2021 at 4:05 AM Hariprasad Kelam <hkelam@marvell.com> wrote:
>
> From: Christina Jacob <cjacob@marvell.com>
>
> CGX block supports forward error correction modes baseR
> and RS. This patch adds support to set encoding mode
> and to read corrected/uncorrected block counters
>
> Adds new mailbox handlers set_fec to configure encoding modes
> and fec_stats to read counters and also increase mbox timeout
> to accomdate firmware command response timeout.
>
> Along with new CGX_CMD_SET_FEC command add other commands to
> sync with kernel enum list with firmware.
>
> Signed-off-by: Christina Jacob <cjacob@marvell.com>
> Signed-off-by: Sunil Goutham <sgoutham@marvell.com>
> Signed-off-by: Hariprasad Kelam <hkelam@marvell.com>
> ---
>  drivers/net/ethernet/marvell/octeontx2/af/cgx.c    | 74 ++++++++++++++++++++++
>  drivers/net/ethernet/marvell/octeontx2/af/cgx.h    |  7 ++
>  .../net/ethernet/marvell/octeontx2/af/cgx_fw_if.h  | 17 ++++-
>  drivers/net/ethernet/marvell/octeontx2/af/mbox.h   | 22 ++++++-
>  .../net/ethernet/marvell/octeontx2/af/rvu_cgx.c    | 33 ++++++++++
>  5 files changed, 151 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/net/ethernet/marvell/octeontx2/af/cgx.c b/drivers/net/ethernet/marvell/octeontx2/af/cgx.c
> index 84a9123..5489dab 100644
> --- a/drivers/net/ethernet/marvell/octeontx2/af/cgx.c
> +++ b/drivers/net/ethernet/marvell/octeontx2/af/cgx.c
> @@ -340,6 +340,58 @@ int cgx_get_tx_stats(void *cgxd, int lmac_id, int idx, u64 *tx_stat)
>         return 0;
>  }
>
> +static int cgx_set_fec_stats_count(struct cgx_link_user_info *linfo)
> +{
> +       if (linfo->fec) {
> +               switch (linfo->lmac_type_id) {
> +               case LMAC_MODE_SGMII:
> +               case LMAC_MODE_XAUI:
> +               case LMAC_MODE_RXAUI:
> +               case LMAC_MODE_QSGMII:
> +                       return 0;
> +               case LMAC_MODE_10G_R:
> +               case LMAC_MODE_25G_R:
> +               case LMAC_MODE_100G_R:
> +               case LMAC_MODE_USXGMII:
> +                       return 1;
> +               case LMAC_MODE_40G_R:
> +                       return 4;
> +               case LMAC_MODE_50G_R:
> +                       if (linfo->fec == OTX2_FEC_BASER)
> +                               return 2;
> +                       else
> +                               return 1;
> +               }
> +       }
> +       return 0;

may consider inverting the condition, to remove one level of indentation.

> +int cgx_set_fec(u64 fec, int cgx_id, int lmac_id)
> +{
> +       u64 req = 0, resp;
> +       struct cgx *cgx;
> +       int err = 0;
> +
> +       cgx = cgx_get_pdata(cgx_id);
> +       if (!cgx)
> +               return -ENXIO;
> +
> +       req = FIELD_SET(CMDREG_ID, CGX_CMD_SET_FEC, req);
> +       req = FIELD_SET(CMDSETFEC, fec, req);
> +       err = cgx_fwi_cmd_generic(req, &resp, cgx, lmac_id);
> +       if (!err) {
> +               cgx->lmac_idmap[lmac_id]->link_info.fec =
> +                       FIELD_GET(RESP_LINKSTAT_FEC, resp);
> +               return cgx->lmac_idmap[lmac_id]->link_info.fec;
> +       }
> +       return err;

Prefer keeping the success path linear and return early if (err) in
explicit branch. This also aids branch prediction.

> +int rvu_mbox_handler_cgx_fec_stats(struct rvu *rvu,
> +                                  struct msg_req *req,
> +                                  struct cgx_fec_stats_rsp *rsp)
> +{
> +       int pf = rvu_get_pf(req->hdr.pcifunc);
> +       u8 cgx_idx, lmac;
> +       int err = 0;
> +       void *cgxd;
> +
> +       if (!is_cgx_config_permitted(rvu, req->hdr.pcifunc))
> +               return -EPERM;
> +       rvu_get_cgx_lmac_id(rvu->pf2cgxlmac_map[pf], &cgx_idx, &lmac);
> +
> +       cgxd = rvu_cgx_pdata(cgx_idx, rvu);
> +       err = cgx_get_fec_stats(cgxd, lmac, rsp);
> +       return err;

no need for variable err