sfc: Document conditions for multicast replication vs filter replacement

Add the efx_filter_is_mc_recip() function to decide whether a filter
is for a multicast recipient and can coexist with other filters with
the same match values.  Update efx_filter_insert_filter() kernel-doc
to explain the conditions for this.

Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>
This commit is contained in:
Ben Hutchings 2013-01-15 22:00:07 +00:00
parent cade715ff1
commit b883d0bd4a
2 changed files with 49 additions and 7 deletions

View file

@ -903,3 +903,37 @@ bool __efx_filter_rfs_expire(struct efx_nic *efx, unsigned int quota)
}
#endif /* CONFIG_RFS_ACCEL */
/**
* efx_filter_is_mc_recipient - test whether spec is a multicast recipient
* @spec: Specification to test
*
* Return: %true if the specification is a non-drop RX filter that
* matches a local MAC address I/G bit value of 1 or matches a local
* IPv4 or IPv6 address value in the respective multicast address
* range. Otherwise %false.
*/
bool efx_filter_is_mc_recipient(const struct efx_filter_spec *spec)
{
if (!(spec->flags & EFX_FILTER_FLAG_RX) ||
spec->dmaq_id == EFX_FILTER_RX_DMAQ_ID_DROP)
return false;
if (spec->match_flags &
(EFX_FILTER_MATCH_LOC_MAC | EFX_FILTER_MATCH_LOC_MAC_IG) &&
is_multicast_ether_addr(spec->loc_mac))
return true;
if ((spec->match_flags &
(EFX_FILTER_MATCH_ETHER_TYPE | EFX_FILTER_MATCH_LOC_HOST)) ==
(EFX_FILTER_MATCH_ETHER_TYPE | EFX_FILTER_MATCH_LOC_HOST)) {
if (spec->ether_type == htons(ETH_P_IP) &&
ipv4_is_multicast(spec->loc_host[0]))
return true;
if (spec->ether_type == htons(ETH_P_IPV6) &&
((const u8 *)spec->loc_host)[0] == 0xff)
return true;
}
return false;
}