From: Jacob Keller Date: Wed, 5 Oct 2016 16:30:40 +0000 (-0700) Subject: i40e: avoid looping to check whether we're in VLAN mode X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=cbebb85f306f6023ebaa26ca66380571b4b680bf;p=linux-beck.git i40e: avoid looping to check whether we're in VLAN mode We determine that a VSI is in vlan_mode whenever it has any filters with a VLAN other than -1 (I40E_VLAN_ALL). The previous method of doing so was to perform a loop whenever we needed the check. However, we can notice that only place where filters are added (i40e_add_filter) can change the condition from false to true, and the only place we can return to false is in i40e_vsi_sync_filters_subtask. Thus, we can remove the loop and use a boolean directly. Doing this avoids looping over filters repeatedly especially while we're already inside a loop over all the filters. This should reduce the latency of filter operations throughout the driver. Change-ID: Iafde08df588da2a2ea666997d05e11fad8edc338 Signed-off-by: Jacob Keller Tested-by: Andrew Bowers Signed-off-by: Jeff Kirsher --- diff --git a/drivers/net/ethernet/intel/i40e/i40e.h b/drivers/net/ethernet/intel/i40e/i40e.h index 6545550f5891..60dbb5b90e1a 100644 --- a/drivers/net/ethernet/intel/i40e/i40e.h +++ b/drivers/net/ethernet/intel/i40e/i40e.h @@ -517,6 +517,7 @@ struct i40e_vsi { spinlock_t mac_filter_hash_lock; /* Fixed size hash table with 2^8 buckets for MAC filters */ DECLARE_HASHTABLE(mac_filter_hash, 8); + bool has_vlan_filter; /* VSI stats */ struct rtnl_link_stats64 net_stats; diff --git a/drivers/net/ethernet/intel/i40e/i40e_main.c b/drivers/net/ethernet/intel/i40e/i40e_main.c index 6cf908953185..b4529b5a6af6 100644 --- a/drivers/net/ethernet/intel/i40e/i40e_main.c +++ b/drivers/net/ethernet/intel/i40e/i40e_main.c @@ -1198,19 +1198,31 @@ struct i40e_mac_filter *i40e_find_mac(struct i40e_vsi *vsi, const u8 *macaddr) **/ bool i40e_is_vsi_in_vlan(struct i40e_vsi *vsi) { - struct i40e_mac_filter *f; - struct hlist_node *h; - int bkt; + /* If we have a PVID, always operate in VLAN mode */ + if (vsi->info.pvid) + return true; - /* Only -1 for all the filters denotes not in vlan mode - * so we have to go through all the list in order to make sure + /* We need to operate in VLAN mode whenever we have any filters with + * a VLAN other than I40E_VLAN_ALL. We could check the table each + * time, incurring search cost repeatedly. However, we can notice two + * things: + * + * 1) the only place where we can gain a VLAN filter is in + * i40e_add_filter. + * + * 2) the only place where filters are actually removed is in + * i40e_vsi_sync_filters_subtask. + * + * Thus, we can simply use a boolean value, has_vlan_filters which we + * will set to true when we add a VLAN filter in i40e_add_filter. Then + * we have to perform the full search after deleting filters in + * i40e_vsi_sync_filters_subtask, but we already have to search + * filters here and can perform the check at the same time. This + * results in avoiding embedding a loop for VLAN mode inside another + * loop over all the filters, and should maintain correctness as noted + * above. */ - hash_for_each_safe(vsi->mac_filter_hash, bkt, h, f, hlist) { - if (f->vlan >= 0 || vsi->info.pvid) - return true; - } - - return false; + return vsi->has_vlan_filter; } /** @@ -1246,6 +1258,12 @@ struct i40e_mac_filter *i40e_add_filter(struct i40e_vsi *vsi, if (!f) return NULL; + /* Update the boolean indicating if we need to function in + * VLAN mode. + */ + if (vlan >= 0) + vsi->has_vlan_filter = true; + ether_addr_copy(f->macaddr, macaddr); f->vlan = vlan; /* If we're in overflow promisc mode, set the state directly @@ -1979,6 +1997,14 @@ int i40e_sync_vsi_filters(struct i40e_vsi *vsi) del_list = NULL; } + /* After finishing notifying firmware of the deleted filters, update + * the cached value of vsi->has_vlan_filter. Note that we are safe to + * use just !!vlan_filters here because if we only have VLAN=0 (that + * is, non_vlan_filters) these will all be converted to VLAN=-1 in the + * logic above already so this value would still be correct. + */ + vsi->has_vlan_filter = !!vlan_filters; + if (!hlist_empty(&tmp_add_list)) { /* Do all the adds now. */ filter_list_len = hw->aq.asq_buf_size /