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

[Gedare Bloom]

thanks, go ahead

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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