ath11k: avoid unnecessary lock contention in tx_completion path

Avoid unnecessary idr_find calls before the idr_remove calls. Because
idr_remove gives the valid ptr if id is valid otherwise return NULL ptr.
So removed the idr_find before idr_remove in tx completion path. Also no
need to disable the bottom half preempt if it is already in the
bottom half context, so modify the spin_lock_bh to spin_lock in the
data tx completion path.

Tested-on: IPQ8074 hw2.0 AHB WLAN.HK.2.4.0.1-01734-QCAHKSWPL_SILICONZ-1 v2

Co-developed-by: Karthikeyan Periyasamy <periyasa@codeaurora.org>
Signed-off-by: Karthikeyan Periyasamy <periyasa@codeaurora.org>
Signed-off-by: Jouni Malinen <jouni@codeaurora.org>
Signed-off-by: P Praneesh <ppranees@codeaurora.org>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
Link: https://lore.kernel.org/r/1630560820-21905-13-git-send-email-ppranees@codeaurora.org

diff --git a/drivers/net/wireless/ath/ath11k/dp_tx.c b/drivers/net/wireless/ath/ath11k/dp_tx.c
index 28a7e2c..88abd64 100644 (file)
--- a/drivers/net/wireless/ath/ath11k/dp_tx.c
+++ b/drivers/net/wireless/ath/ath11k/dp_tx.c
@@ -293,20 +293,18 @@ static void ath11k_dp_tx_free_txbuf(struct ath11k_base *ab, u8 mac_id,
        struct sk_buff *msdu;
        struct ath11k_skb_cb *skb_cb;
 
-       spin_lock_bh(&tx_ring->tx_idr_lock);
-       msdu = idr_find(&tx_ring->txbuf_idr, msdu_id);
-       if (!msdu) {
+       spin_lock(&tx_ring->tx_idr_lock);
+       msdu = idr_remove(&tx_ring->txbuf_idr, msdu_id);
+       spin_unlock(&tx_ring->tx_idr_lock);
+
+       if (unlikely(!msdu)) {
                ath11k_warn(ab, "tx completion for unknown msdu_id %d\n",
                            msdu_id);
-               spin_unlock_bh(&tx_ring->tx_idr_lock);
                return;
        }
 
        skb_cb = ATH11K_SKB_CB(msdu);
 
-       idr_remove(&tx_ring->txbuf_idr, msdu_id);
-       spin_unlock_bh(&tx_ring->tx_idr_lock);
-
        dma_unmap_single(ab->dev, skb_cb->paddr, msdu->len, DMA_TO_DEVICE);
        dev_kfree_skb_any(msdu);
 
@@ -325,12 +323,13 @@ ath11k_dp_tx_htt_tx_complete_buf(struct ath11k_base *ab,
        struct ath11k_skb_cb *skb_cb;
        struct ath11k *ar;
 
-       spin_lock_bh(&tx_ring->tx_idr_lock);
-       msdu = idr_find(&tx_ring->txbuf_idr, ts->msdu_id);
+       spin_lock(&tx_ring->tx_idr_lock);
+       msdu = idr_remove(&tx_ring->txbuf_idr, ts->msdu_id);
+       spin_unlock(&tx_ring->tx_idr_lock);
+
        if (unlikely(!msdu)) {
                ath11k_warn(ab, "htt tx completion for unknown msdu_id %d\n",
                            ts->msdu_id);
-               spin_unlock_bh(&tx_ring->tx_idr_lock);
                return;
        }
 
@@ -339,9 +338,6 @@ ath11k_dp_tx_htt_tx_complete_buf(struct ath11k_base *ab,
 
        ar = skb_cb->ar;
 
-       idr_remove(&tx_ring->txbuf_idr, ts->msdu_id);
-       spin_unlock_bh(&tx_ring->tx_idr_lock);
-
        if (atomic_dec_and_test(&ar->dp.num_tx_pending))
                wake_up(&ar->dp.tx_empty_waitq);
 
@@ -584,16 +580,16 @@ void ath11k_dp_tx_completion_handler(struct ath11k_base *ab, int ring_id)
                        continue;
                }
 
-               spin_lock_bh(&tx_ring->tx_idr_lock);
-               msdu = idr_find(&tx_ring->txbuf_idr, msdu_id);
+               spin_lock(&tx_ring->tx_idr_lock);
+               msdu = idr_remove(&tx_ring->txbuf_idr, msdu_id);
                if (unlikely(!msdu)) {
                        ath11k_warn(ab, "tx completion for unknown msdu_id %d\n",
                                    msdu_id);
-                       spin_unlock_bh(&tx_ring->tx_idr_lock);
+                       spin_unlock(&tx_ring->tx_idr_lock);
                        continue;
                }
-               idr_remove(&tx_ring->txbuf_idr, msdu_id);
-               spin_unlock_bh(&tx_ring->tx_idr_lock);
+
+               spin_unlock(&tx_ring->tx_idr_lock);
 
                ar = ab->pdevs[mac_id].ar;