From b883d0bd4ae91059242fd2f8c2a70f308ef63dc1 Mon Sep 17 00:00:00 2001 From: Ben Hutchings Date: Tue, 15 Jan 2013 22:00:07 +0000 Subject: [PATCH] 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 --- drivers/net/ethernet/sfc/efx.h | 22 +++++++++++++++------- drivers/net/ethernet/sfc/rx.c | 34 ++++++++++++++++++++++++++++++++++ 2 files changed, 49 insertions(+), 7 deletions(-) diff --git a/drivers/net/ethernet/sfc/efx.h b/drivers/net/ethernet/sfc/efx.h index 3bbc047baea2..9de28f69c6aa 100644 --- a/drivers/net/ethernet/sfc/efx.h +++ b/drivers/net/ethernet/sfc/efx.h @@ -79,13 +79,20 @@ extern void efx_schedule_slow_fill(struct efx_rx_queue *rx_queue); * On success, return the filter ID. * On failure, return a negative error code. * - * If an existing filter has equal match values to the new filter - * spec, then the new filter might replace it, depending on the - * relative priorities. If the existing filter has lower priority, or - * if @replace_equal is set and it has equal priority, then it is - * replaced. Otherwise the function fails, returning -%EPERM if - * the existing filter has higher priority or -%EEXIST if it has - * equal priority. + * If existing filters have equal match values to the new filter spec, + * then the new filter might replace them or the function might fail, + * as follows. + * + * 1. If the existing filters have lower priority, or @replace_equal + * is set and they have equal priority, replace them. + * + * 2. If the existing filters have higher priority, return -%EPERM. + * + * 3. If !efx_filter_is_mc_recipient(@spec), or the NIC does not + * support delivery to multiple recipients, return -%EEXIST. + * + * This implies that filters for multiple multicast recipients must + * all be inserted with the same priority and @replace_equal = %false. */ static inline s32 efx_filter_insert_filter(struct efx_nic *efx, struct efx_filter_spec *spec, @@ -169,6 +176,7 @@ static inline void efx_filter_rfs_expire(struct efx_channel *channel) static inline void efx_filter_rfs_expire(struct efx_channel *channel) {} #define efx_filter_rfs_enabled() 0 #endif +extern bool efx_filter_is_mc_recipient(const struct efx_filter_spec *spec); /* Channels */ extern int efx_channel_dummy_op_int(struct efx_channel *channel); diff --git a/drivers/net/ethernet/sfc/rx.c b/drivers/net/ethernet/sfc/rx.c index 864b6ffc9cb2..81eab21effe9 100644 --- a/drivers/net/ethernet/sfc/rx.c +++ b/drivers/net/ethernet/sfc/rx.c @@ -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; +} -- 2.39.5