Re: [Qemu-devel] [PATCHv2 4/5] eepro100: switch e100_compute_mcast_idx() over to use net_crc32()

[Mark Cave-Ayland]

On 05/12/17 15:13, Stefan Weil wrote:

> Am 05.12.2017 um 09:17 schrieb Mark Cave-Ayland:
> > Signed-off-by: Mark Cave-Ayland <address@hidden>
> > ---
> >   hw/net/eepro100.c | 19 +------------------
> >   1 file changed, 1 insertion(+), 18 deletions(-)
> >
> > diff --git a/hw/net/eepro100.c b/hw/net/eepro100.c
> > index 1c0def555b..4fe94b7471 100644
> > --- a/hw/net/eepro100.c
> > +++ b/hw/net/eepro100.c
> > @@ -327,26 +327,9 @@ static const uint16_t eepro100_mdi_mask[] = {
> >   
> >   static E100PCIDeviceInfo *eepro100_get_class(EEPRO100State *s);
> >   
> > -/* From FreeBSD (locally modified). */
> >   static unsigned e100_compute_mcast_idx(const uint8_t *ep)
> >   {
> > -    uint32_t crc;
> > -    int carry, i, j;
> > -    uint8_t b;
> > -
> > -    crc = 0xffffffff;
> > -    for (i = 0; i < 6; i++) {
> > -        b = *ep++;
> > -        for (j = 0; j < 8; j++) {
> > -            carry = ((crc & 0x80000000L) ? 1 : 0) ^ (b & 0x01);
> > -            crc <<= 1;
> > -            b >>= 1;
> > -            if (carry) {
> > -                crc = ((crc ^ POLYNOMIAL) | carry);
> > -            }
> > -        }
> > -    }
> > -    return (crc & BITS(7, 2)) >> 2;
> > +    return (net_crc32(ep, 6) & BITS(7, 2)) >> 2;
> >   }
> >   
> >   /* Read a 16 bit control/status (CSR) register. */
>
>
> What about eliminating the intermediate function e100_compute_mcast_idx (and 
> function lnc_mchash, too)?
> You did that for lnc_mchash, and I think that is cleaner and saves some lines 
> of code.

Yes, I can do if you like. The reason I've left these as they are for 
the moment is that I don't have something readily available to test 
multicast for eepro100 post-conversion (my SPARC/PPC images cover 
pcnet/sunhme) but if you are happy the functionality is the same during 
review then I can go ahead and do it.

I don't really mind exactly how we do the conversion as long as we aim 
for consistency.

> With or without that minor change:
>
> Reviewed-by: Stefan Weil <address@hidden>
>
> Regards
> Stefan

ATB,

Mark.