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

[Stefan Weil]

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.

With or without that minor change:

Reviewed-by: Stefan Weil <address@hidden>

Regards
Stefan