[RFC] wifi: ath10k: Implement duplicate detection for non-offloaded PCIe

[Zhi-Jun You]

Chips like QCA9984, IPQ4019 doesn't do duplicate detection in firmware.
Implement it in driver so it can skip a check in mac80211.

Check only the first skb since all the skbs in amsdu share the same
header.

Tested-on: QCA9984 10.4-3.9.0.2-00159
Signed-off-by: Zhi-Jun You <hujy652 at gmail.com>
---

I am not sure what's the formal name for chips like QCA9984 so I will
call it non-offloaded PCIe for now.
---
 drivers/net/wireless/ath/ath10k/core.h   |  1 +
 drivers/net/wireless/ath/ath10k/htt_rx.c | 51 ++++++++++++++++++++++++
 drivers/net/wireless/ath/ath10k/txrx.c   |  3 ++
 3 files changed, 55 insertions(+)

diff --git a/drivers/net/wireless/ath/ath10k/core.h b/drivers/net/wireless/ath/ath10k/core.h
index f5de8ce8fb45..6b4f5208f32f 100644
--- a/drivers/net/wireless/ath/ath10k/core.h
+++ b/drivers/net/wireless/ath/ath10k/core.h
@@ -436,6 +436,7 @@ struct ath10k_peer {
 		enum htt_security_types sec_type;
 		int pn_len;
 	} rx_pn[ATH10K_HTT_TXRX_PEER_SECURITY_MAX];
+	u16 last_rx_seq_ctrl[IEEE80211_NUM_TIDS + 1];
 };
 
 struct ath10k_txq {
diff --git a/drivers/net/wireless/ath/ath10k/htt_rx.c b/drivers/net/wireless/ath/ath10k/htt_rx.c
index 438b0caaceb7..e241eab4cce1 100644
--- a/drivers/net/wireless/ath/ath10k/htt_rx.c
+++ b/drivers/net/wireless/ath/ath10k/htt_rx.c
@@ -1344,6 +1344,56 @@ static char *ath10k_get_tid(struct ieee80211_hdr *hdr, char *out, size_t size)
 	return out;
 }
 
+static void ath10k_htt_rx_h_check_dup(struct ath10k *ar,
+				      struct sk_buff_head *amsdu,
+				      struct ieee80211_rx_status *status)
+{
+	struct ath10k_hw_params *hw = &ar->hw_params;
+	struct sk_buff *first;
+	struct ath10k_peer *peer;
+	struct ieee80211_hdr *hdr;
+	struct htt_rx_desc *rxd;
+	struct rx_mpdu_start *rxd_mpdu_start;
+	u16 peer_id;
+	u8 tid;
+
+	if (skb_queue_empty(amsdu))
+		return;
+
+	first = skb_peek(amsdu);
+	rxd = HTT_RX_BUF_TO_RX_DESC(hw,
+				    (void *)first->data - hw->rx_desc_ops->rx_desc_size);
+
+	rxd_mpdu_start = ath10k_htt_rx_desc_get_mpdu_start(hw, rxd);
+	peer_id = MS(__le32_to_cpu(rxd_mpdu_start->info0),
+		     RX_MPDU_START_INFO0_PEER_IDX);
+
+	spin_lock_bh(&ar->data_lock);
+
+	peer = ath10k_peer_find_by_id(ar, peer_id);
+	if (!peer)
+		goto out;
+
+	hdr = (void *)ath10k_htt_rx_desc_get_rx_hdr_status(hw, rxd);
+	if (ieee80211_is_data_qos(hdr->frame_control))
+		tid = ieee80211_get_tid(hdr);
+	else
+		tid = ATH10K_TXRX_NON_QOS_TID;
+
+	if (ieee80211_has_retry(hdr->frame_control) &&
+	    peer->last_rx_seq_ctrl[tid] == __le16_to_cpu(hdr->seq_ctrl)) {
+		__skb_queue_purge(amsdu);
+		goto out;
+	}
+
+	peer->last_rx_seq_ctrl[tid] = __le16_to_cpu(hdr->seq_ctrl);
+
+	status->flag |= RX_FLAG_DUP_VALIDATED;
+
+out:
+	spin_unlock_bh(&ar->data_lock);
+}
+
 static void ath10k_htt_rx_h_queue_msdu(struct ath10k *ar,
 				       struct ieee80211_rx_status *rx_status,
 				       struct sk_buff *skb)
@@ -2356,6 +2406,7 @@ static int ath10k_htt_rx_handle_amsdu(struct ath10k_htt *htt)
 		ath10k_htt_rx_h_unchain(ar, &amsdu, &drop_cnt, &unchain_cnt);
 
 	ath10k_htt_rx_h_filter(ar, &amsdu, rx_status, &drop_cnt_filter);
+	ath10k_htt_rx_h_check_dup(ar, &amsdu, rx_status);
 	ath10k_htt_rx_h_mpdu(ar, &amsdu, rx_status, true, first_hdr, &err, 0,
 			     false);
 	msdus_to_queue = skb_queue_len(&amsdu);
diff --git a/drivers/net/wireless/ath/ath10k/txrx.c b/drivers/net/wireless/ath/ath10k/txrx.c
index da3bc35e41aa..a8b8186537f4 100644
--- a/drivers/net/wireless/ath/ath10k/txrx.c
+++ b/drivers/net/wireless/ath/ath10k/txrx.c
@@ -219,6 +219,7 @@ void ath10k_peer_map_event(struct ath10k_htt *htt,
 {
 	struct ath10k *ar = htt->ar;
 	struct ath10k_peer *peer;
+	int i;
 
 	if (ev->peer_id >= ATH10K_MAX_NUM_PEER_IDS) {
 		ath10k_warn(ar,
@@ -237,6 +238,8 @@ void ath10k_peer_map_event(struct ath10k_htt *htt,
 		peer->vdev_id = ev->vdev_id;
 		ether_addr_copy(peer->addr, ev->addr);
 		list_add(&peer->list, &ar->peers);
+		for (i = 0; i <= IEEE80211_NUM_TIDS; i++)
+			peer->last_rx_sec_ctrl[i] = USHRT_MAX;
 		wake_up(&ar->peer_mapping_wq);
 	}
 
-- 
2.34.1