> +static void lan966x_ifh_inject(u32 *ifh, size_t val, size_t pos, size_t length)
> +{
> + int i;
> +
> + for (i = pos; i < pos + length; ++i) {
> + if (val & BIT(i - pos))
> + ifh[IFH_LEN - i / 32 - 1] |= BIT(i % 32);
> + else
> + ifh[IFH_LEN - i / 32 - 1] &= ~(BIT(i % 32));
> + }
> +}
> +
> +static void lan966x_gen_ifh(u32 *ifh, struct lan966x_frame_info *info,
> + struct lan966x *lan966x)
> +{
> + lan966x_ifh_inject(ifh, 1, IFH_POS_BYPASS, 1);
> + lan966x_ifh_inject(ifh, info->port, IFH_POS_DSTS, IFH_WID_DSTS);
> + lan966x_ifh_inject(ifh, info->qos_class, IFH_POS_QOS_CLASS,
> + IFH_WID_QOS_CLASS);
> + lan966x_ifh_inject(ifh, info->ipv, IFH_POS_IPV, IFH_WID_IPV);
> +}
> +
> + /* Write IFH header */
> + for (i = 0; i < IFH_LEN; ++i) {
> + /* Wait until the fifo is ready */
> + while (!(QS_INJ_STATUS_FIFO_RDY_GET(lan_rd(lan966x, QS_INJ_STATUS)) &
> + BIT(grp)))
> + ;
> +
> + lan_wr((__force u32)cpu_to_be32(ifh[i]), lan966x,
> + QS_INJ_WR(grp));
There is a lot of magic going on here constructing the IFH. Is it
possible to define the structure using bit fields and __be32. You
should then be able to skip this cpu_to_be32 and the ugly cast. And
the actual structure should be a lot clearer.
> +static int lan966x_rx_frame_word(struct lan966x *lan966x, u8 grp, bool ifh,
> + u32 *rval)
> +{
> + u32 bytes_valid;
> + u32 val;
> +
> + val = lan_rd(lan966x, QS_XTR_RD(grp));
> + if (val == XTR_NOT_READY) {
> + if (ifh)
> + return -EIO;
> +
> + do {
> + val = lan_rd(lan966x, QS_XTR_RD(grp));
> + } while (val == XTR_NOT_READY);
I would add some sort of timeout here, just in case the hardware
breaks. You have quite a few such loops, it would be better to make
use of the helpers in linux/iopoll.h.
