+From: Felix Fietkau <nbd@nbd.name>
+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 <nbd@nbd.name>
+---
+
+--- 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
+@@ -2552,8 +2552,8 @@ 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);
+ }
+@@ -3843,7 +3843,6 @@ 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;
+
+@@ -4453,8 +4452,8 @@ 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);
+
+@@ -4521,7 +4520,7 @@ 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;
+@@ -4536,7 +4535,7 @@ 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);
+@@ -4644,8 +4643,8 @@ 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;
+@@ -4737,36 +4736,53 @@ 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
projects / openwrt / staging / chunkeey.git / commitdiff