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

[Hariprasad Kelam]

Hi Willem,

> -----Original Message-----
> From: Willem de Bruijn <willemdebruijn.kernel@xxxxxxxxx>
> Sent: Thursday, January 28, 2021 1:45 AM
> To: Hariprasad Kelam <hkelam@xxxxxxxxxxx>
> Cc: Network Development <netdev@xxxxxxxxxxxxxxx>; LKML <linux-
> kernel@xxxxxxxxxxxxxxx>; David Miller <davem@xxxxxxxxxxxxx>; Jakub
> Kicinski <kuba@xxxxxxxxxx>; Sunil Kovvuri Goutham
> <sgoutham@xxxxxxxxxxx>; Linu Cherian <lcherian@xxxxxxxxxxx>;
> Geethasowjanya Akula <gakula@xxxxxxxxxxx>; Jerin Jacob Kollanukkaran
> <jerinj@xxxxxxxxxxx>; Subbaraya Sundeep Bhatta <sbhatta@xxxxxxxxxxx>;
> Christina Jacob <cjacob@xxxxxxxxxxx>
> Subject: [EXT] Re: [Patch v2 net-next 1/7] octeontx2-af: forward error
> correction configuration
> 
> External Email
> 
> ----------------------------------------------------------------------
> On Wed, Jan 27, 2021 at 4:05 AM Hariprasad Kelam <hkelam@xxxxxxxxxxx>
> wrote:
> >
> > From: Christina Jacob <cjacob@xxxxxxxxxxx>
> >
> > 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@xxxxxxxxxxx>
> > Signed-off-by: Sunil Goutham <sgoutham@xxxxxxxxxxx>
> > Signed-off-by: Hariprasad Kelam <hkelam@xxxxxxxxxxx>
> > ---
> >  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.
> 
Agreed. Will fix in next version.

> > +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.
>
Agreed. Will fix this in next version.
 
> > +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
Agreed will fix this in next version.

Thanks,
Hariprasad k