The 11/24/2021 18:59, Andrew Lunn wrote:
Hi Andrew,
>
> > +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.
If I undestood you correctly I have tried to do the following:
struct lan966x_ifh {
__be32 timestamp;
__be32 bypass : 1;
__be32 port : 3;
...
};
But then I start to get errors from sparse:
error: invalid bitfield specifier for type restricted __be32.
On thing that I can do is to use packing() instead of
lan966x_ifh_inject() and declare ifh as __be32.
I think this will also work and simplify a little bit the code.
>
> > +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.
Yes, I will do that, I will also add sime timeout also for injection.
>
--
/Horatiu
