[PATCH rtems-net-legacy] leon, greth: added support for variable sized descriptor table sizes

[Vijay Kumar Banerjee]

On Tue, Mar 30, 2021 at 10:22 AM Gedare Bloom <gedare at rtems.org> wrote:
>
> thanks, go ahead
>
Pushed. Thanks

> On Tue, Mar 30, 2021 at 9:52 AM Vijay Kumar Banerjee <vijay at rtems.org> wrote:
> >
> > From: Daniel Hellstrom <daniel at gaisler.com>
> >
> >     The descriptor table size is equal to its alignment and set when
> >     configuring the HW IP through VHDL generics. This SW patch simply
> >     probes the HW how large the RX/TX descriptor tables are and adjusts
> >     accordingly.
> >
> >     The number of descriptors actual used are controlled by other
> >     settings (rxDescs and txDescs) controlled by the user.
> > ---
> >  bsps/shared/grlib/net/greth.c | 22 +++++++++++++++-------
> >  1 file changed, 15 insertions(+), 7 deletions(-)
> >
> > diff --git a/bsps/shared/grlib/net/greth.c b/bsps/shared/grlib/net/greth.c
> > index 8b19b48..84efcd7 100644
> > --- a/bsps/shared/grlib/net/greth.c
> > +++ b/bsps/shared/grlib/net/greth.c
> > @@ -187,6 +187,7 @@ struct greth_softc
> >     unsigned int advmodes; /* advertise ethernet speed modes. 0 = all modes. */
> >     struct timespec auto_neg_time;
> >     int mc_available;
> > +   int num_descs;
> >
> >     /*
> >      * Statistics
> > @@ -423,7 +424,7 @@ greth_initialize_hardware (struct greth_softc *sc)
> >      int tmp2;
> >      struct timespec tstart, tnow;
> >      greth_regs *regs;
> > -    unsigned int advmodes, speed;
> > +    unsigned int advmodes, speed, tabsize;
> >
> >      regs = sc->regs;
> >
> > @@ -617,8 +618,9 @@ auto_neg_done:
> >      /* Initialize rx/tx descriptor table pointers. Due to alignment we
> >       * always allocate maximum table size.
> >       */
> > -    sc->txdesc = (greth_rxtxdesc *) almalloc(0x800, 0x400);
> > -    sc->rxdesc = (greth_rxtxdesc *) &sc->txdesc[128];
> > +    tabsize = sc->num_descs * 8;
> > +    sc->txdesc = (greth_rxtxdesc *) almalloc(tabsize * 2, tabsize);
> > +    sc->rxdesc = (greth_rxtxdesc *) (tabsize + (void *)sc->txdesc);
> >      sc->tx_ptr = 0;
> >      sc->tx_dptr = 0;
> >      sc->tx_cnt = 0;
> > @@ -632,8 +634,8 @@ auto_neg_done:
> >          CPUMEM_TO_DMA,
> >          (void *)sc->txdesc,
> >          (void **)&sc->txdesc_remote,
> > -        0x800);
> > -    sc->rxdesc_remote = sc->txdesc_remote + 0x400;
> > +        tabsize * 2);
> > +    sc->rxdesc_remote = sc->txdesc_remote + tabsize;
> >      regs->txdesc = (int) sc->txdesc_remote;
> >      regs->rxdesc = (int) sc->rxdesc_remote;
> >
> > @@ -1555,6 +1557,7 @@ int greth_device_init(struct greth_softc *sc)
> >      struct ambapp_core *pnpinfo;
> >      union drvmgr_key_value *value;
> >      unsigned int speed;
> > +    int i, nrd;
> >
> >      /* Get device information from AMBA PnP information */
> >      ambadev = (struct amba_dev_info *)sc->dev->businfo;
> > @@ -1608,12 +1611,17 @@ int greth_device_init(struct greth_softc *sc)
> >      sc->rxbufs = 32;
> >      sc->phyaddr = -1;
> >
> > +    /* Probe the number of descriptors available the */
> > +    nrd = (sc->regs->status & GRETH_STATUS_NRD) >> 24;
> > +    for (sc->num_descs = 128, i = 0; i < nrd; i++)
> > +        sc->num_descs = sc->num_descs * 2;
> > +
> >      value = drvmgr_dev_key_get(sc->dev, "txDescs", DRVMGR_KT_INT);
> > -    if ( value && (value->i <= 128) )
> > +    if ( value && (value->i <= sc->num_descs) )
> >          sc->txbufs = value->i;
> >
> >      value = drvmgr_dev_key_get(sc->dev, "rxDescs", DRVMGR_KT_INT);
> > -    if ( value && (value->i <= 128) )
> > +    if ( value && (value->i <= sc->num_descs) )
> >          sc->rxbufs = value->i;
> >
> >      value = drvmgr_dev_key_get(sc->dev, "phyAdr", DRVMGR_KT_INT);
> > --
> > 2.26.2
> >
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