From: Felix Fietkau Date: Sat, 25 Jul 2020 20:53:23 +0200 Subject: [PATCH] mac80211: add a function for running rx without passing skbs to the stack This can be used to run mac80211 rx processing on a batch of frames in NAPI poll before passing them to the network stack in a large batch. This can improve icache footprint, or it can be used to pass frames via netif_receive_skb_list. Signed-off-by: Felix Fietkau --- --- a/include/net/mac80211.h +++ b/include/net/mac80211.h @@ -4358,6 +4358,31 @@ void ieee80211_free_hw(struct ieee80211_ void ieee80211_restart_hw(struct ieee80211_hw *hw); /** + * ieee80211_rx_list - receive frame and store processed skbs in a list + * + * Use this function to hand received frames to mac80211. The receive + * buffer in @skb must start with an IEEE 802.11 header. In case of a + * paged @skb is used, the driver is recommended to put the ieee80211 + * header of the frame on the linear part of the @skb to avoid memory + * allocation and/or memcpy by the stack. + * + * This function may not be called in IRQ context. Calls to this function + * for a single hardware must be synchronized against each other. Calls to + * this function, ieee80211_rx_ni() and ieee80211_rx_irqsafe() may not be + * mixed for a single hardware. Must not run concurrently with + * ieee80211_tx_status() or ieee80211_tx_status_ni(). + * + * This function must be called with BHs disabled and RCU read lock + * + * @hw: the hardware this frame came in on + * @sta: the station the frame was received from, or %NULL + * @skb: the buffer to receive, owned by mac80211 after this call + * @list: the destination list + */ +void ieee80211_rx_list(struct ieee80211_hw *hw, struct ieee80211_sta *sta, + struct sk_buff *skb, struct list_head *list); + +/** * ieee80211_rx_napi - receive frame from NAPI context * * Use this function to hand received frames to mac80211. The receive --- a/net/mac80211/ieee80211_i.h +++ b/net/mac80211/ieee80211_i.h @@ -218,7 +218,7 @@ enum ieee80211_rx_flags { }; struct ieee80211_rx_data { - struct napi_struct *napi; + struct list_head *list; struct sk_buff *skb; struct ieee80211_local *local; struct ieee80211_sub_if_data *sdata; --- a/net/mac80211/rx.c +++ b/net/mac80211/rx.c @@ -2578,8 +2578,8 @@ static void ieee80211_deliver_skb_to_loc memset(skb->cb, 0, sizeof(skb->cb)); /* deliver to local stack */ - if (rx->napi) - napi_gro_receive(rx->napi, skb); + if (rx->list) + list_add_tail(&skb->list, rx->list); else netif_receive_skb(skb); } @@ -3869,7 +3869,6 @@ void ieee80211_release_reorder_timeout(s /* This is OK -- must be QoS data frame */ .security_idx = tid, .seqno_idx = tid, - .napi = NULL, /* must be NULL to not have races */ }; struct tid_ampdu_rx *tid_agg_rx; @@ -4479,8 +4478,8 @@ static bool ieee80211_invoke_fast_rx(str /* deliver to local stack */ skb->protocol = eth_type_trans(skb, fast_rx->dev); memset(skb->cb, 0, sizeof(skb->cb)); - if (rx->napi) - napi_gro_receive(rx->napi, skb); + if (rx->list) + list_add_tail(&skb->list, rx->list); else netif_receive_skb(skb); @@ -4547,7 +4546,7 @@ static bool ieee80211_prepare_and_rx_han static void __ieee80211_rx_handle_packet(struct ieee80211_hw *hw, struct ieee80211_sta *pubsta, struct sk_buff *skb, - struct napi_struct *napi) + struct list_head *list) { struct ieee80211_local *local = hw_to_local(hw); struct ieee80211_sub_if_data *sdata; @@ -4562,7 +4561,7 @@ static void __ieee80211_rx_handle_packet memset(&rx, 0, sizeof(rx)); rx.skb = skb; rx.local = local; - rx.napi = napi; + rx.list = list; if (ieee80211_is_data(fc) || ieee80211_is_mgmt(fc)) I802_DEBUG_INC(local->dot11ReceivedFragmentCount); @@ -4670,8 +4669,8 @@ static void __ieee80211_rx_handle_packet * This is the receive path handler. It is called by a low level driver when an * 802.11 MPDU is received from the hardware. */ -void ieee80211_rx_napi(struct ieee80211_hw *hw, struct ieee80211_sta *pubsta, - struct sk_buff *skb, struct napi_struct *napi) +void ieee80211_rx_list(struct ieee80211_hw *hw, struct ieee80211_sta *pubsta, + struct sk_buff *skb, struct list_head *list) { struct ieee80211_local *local = hw_to_local(hw); struct ieee80211_rate *rate = NULL; @@ -4763,36 +4762,53 @@ void ieee80211_rx_napi(struct ieee80211_ status->rx_flags = 0; /* - * key references and virtual interfaces are protected using RCU - * and this requires that we are in a read-side RCU section during - * receive processing - */ - rcu_read_lock(); - - /* * Frames with failed FCS/PLCP checksum are not returned, * all other frames are returned without radiotap header * if it was previously present. * Also, frames with less than 16 bytes are dropped. */ skb = ieee80211_rx_monitor(local, skb, rate); - if (!skb) { - rcu_read_unlock(); + if (!skb) return; - } ieee80211_tpt_led_trig_rx(local, ((struct ieee80211_hdr *)skb->data)->frame_control, skb->len); - __ieee80211_rx_handle_packet(hw, pubsta, skb, napi); - - rcu_read_unlock(); + __ieee80211_rx_handle_packet(hw, pubsta, skb, list); return; drop: kfree_skb(skb); } +EXPORT_SYMBOL(ieee80211_rx_list); + +void ieee80211_rx_napi(struct ieee80211_hw *hw, struct ieee80211_sta *pubsta, + struct sk_buff *skb, struct napi_struct *napi) +{ + struct sk_buff *tmp; + LIST_HEAD(list); + + + /* + * key references and virtual interfaces are protected using RCU + * and this requires that we are in a read-side RCU section during + * receive processing + */ + rcu_read_lock(); + ieee80211_rx_list(hw, pubsta, skb, &list); + rcu_read_unlock(); + + if (!napi) { + netif_receive_skb_list(&list); + return; + } + + list_for_each_entry_safe(skb, tmp, &list, list) { + skb_list_del_init(skb); + napi_gro_receive(napi, skb); + } +} EXPORT_SYMBOL(ieee80211_rx_napi); /* This is a version of the rx handler that can be called from hard irq