Re: [Qemu-devel] [PATCHv2 5/5] sunhme: switch sunhme_receive() over to use net_crc32_le()

[Philippe Mathieu-Daudé]

Hi Mark,

On 12/05/2017 05:17 AM, Mark Cave-Ayland wrote:
> Signed-off-by: Mark Cave-Ayland <address@hidden>
> ---
>  hw/net/sunhme.c | 25 +------------------------
>  1 file changed, 1 insertion(+), 24 deletions(-)
> 
> diff --git a/hw/net/sunhme.c b/hw/net/sunhme.c
> index b1efa1b88d..df66e2630c 100644
> --- a/hw/net/sunhme.c
> +++ b/hw/net/sunhme.c
> @@ -698,29 +698,6 @@ static inline void sunhme_set_rx_ring_nr(SunHMEState *s, 
> int i)
>      s->erxregs[HME_ERXI_RING >> 2] = ring;
>  }
>  
> -#define POLYNOMIAL_LE 0xedb88320
> -static uint32_t sunhme_crc32_le(const uint8_t *p, int len)
> -{
> -    uint32_t crc;
> -    int carry, i, j;
> -    uint8_t b;
> -
> -    crc = 0xffffffff;
> -    for (i = 0; i < len; i++) {
> -        b = *p++;
> -        for (j = 0; j < 8; j++) {
> -            carry = (crc & 0x1) ^ (b & 0x01);
> -            crc >>= 1;
> -            b >>= 1;
> -            if (carry) {
> -                crc = crc ^ POLYNOMIAL_LE;
> -            }
> -        }
> -    }
> -
> -    return crc;
> -}
> -
>  #define MIN_BUF_SIZE 60
>  
>  static ssize_t sunhme_receive(NetClientState *nc, const uint8_t *buf,
> @@ -761,7 +738,7 @@ static ssize_t sunhme_receive(NetClientState *nc, const 
> uint8_t *buf,
>              trace_sunhme_rx_filter_bcast_match();
>          } else if (s->macregs[HME_MACI_RXCFG >> 2] & HME_MAC_RXCFG_HENABLE) {
>              /* Didn't match local address, check hash filter */
> -            int mcast_idx = sunhme_crc32_le(buf, 6) >> 26;

This could be:

               int mcast_idx = compute_mcast_idx_le(buf);

With:

unsigned compute_mcast_idx_le(const uint8_t *ep)
{
    return net_crc32(ep, ETH_ALEN) >> 26;
}

Anyway:
Reviewed-by: Philippe Mathieu-Daudé <address@hidden>

> +            int mcast_idx = net_crc32_le(buf, 6) >> 26;
>              if (!(s->macregs[(HME_MACI_HASHTAB0 >> 2) - (mcast_idx >> 4)] &
>                      (1 << (mcast_idx & 0xf)))) {
>                  /* Didn't match hash filter */
>