wifi: ath11k: fix BUFFER_DONE read on monitor ring rx buffer

Perform dma_sync_single_for_cpu() on monitor ring rx buffer before
reading BUFFER_DONE tag and do dma_unmap_single() only after device
had set BUFFER_DONE tag to the buffer.

Also when BUFFER_DONE tag is not set, allow the buffer to get read
next time without freeing skb.

This helps to fix AP+Monitor VAP with flood traffic scenario to see
monitor ring rx buffer overrun missing BUFFER_DONE tag to be set.

Also remove redundant rx dma buf free performed on DP
rx_mon_status_refill_ring.

Tested-on: IPQ8074 hw2.0 AHB WLAN.HK.2.7.0.1-01744-QCAHKSWPL_SILICONZ-1

Signed-off-by: Sathishkumar Muruganandam <quic_murugana@quicinc.com>
Signed-off-by: Harshitha Prem <quic_hprem@quicinc.com>
Signed-off-by: Kalle Valo <quic_kvalo@quicinc.com>
Link: https://lore.kernel.org/r/20230309164434.32660-1-quic_hprem@quicinc.com

diff --git a/drivers/net/wireless/ath/ath11k/dp_rx.c b/drivers/net/wireless/ath/ath11k/dp_rx.c
index b65a84a..99859b5 100644 (file)
--- a/drivers/net/wireless/ath/ath11k/dp_rx.c
+++ b/drivers/net/wireless/ath/ath11k/dp_rx.c
@@ -435,7 +435,6 @@ fail_free_skb:
 static int ath11k_dp_rxdma_buf_ring_free(struct ath11k *ar,
                                         struct dp_rxdma_ring *rx_ring)
 {
-       struct ath11k_pdev_dp *dp = &ar->dp;
        struct sk_buff *skb;
        int buf_id;
 
@@ -453,28 +452,6 @@ static int ath11k_dp_rxdma_buf_ring_free(struct ath11k *ar,
        idr_destroy(&rx_ring->bufs_idr);
        spin_unlock_bh(&rx_ring->idr_lock);
 
-       /* if rxdma1_enable is false, mon_status_refill_ring
-        * isn't setup, so don't clean.
-        */
-       if (!ar->ab->hw_params.rxdma1_enable)
-               return 0;
-
-       rx_ring = &dp->rx_mon_status_refill_ring[0];
-
-       spin_lock_bh(&rx_ring->idr_lock);
-       idr_for_each_entry(&rx_ring->bufs_idr, skb, buf_id) {
-               idr_remove(&rx_ring->bufs_idr, buf_id);
-               /* XXX: Understand where internal driver does this dma_unmap
-                * of rxdma_buffer.
-                */
-               dma_unmap_single(ar->ab->dev, ATH11K_SKB_RXCB(skb)->paddr,
-                                skb->len + skb_tailroom(skb), DMA_BIDIRECTIONAL);
-               dev_kfree_skb_any(skb);
-       }
-
-       idr_destroy(&rx_ring->bufs_idr);
-       spin_unlock_bh(&rx_ring->idr_lock);
-
        return 0;
 }
 
@@ -3029,39 +3006,51 @@ static int ath11k_dp_rx_reap_mon_status_ring(struct ath11k_base *ab, int mac_id,
 
                        spin_lock_bh(&rx_ring->idr_lock);
                        skb = idr_find(&rx_ring->bufs_idr, buf_id);
+                       spin_unlock_bh(&rx_ring->idr_lock);
+
                        if (!skb) {
                                ath11k_warn(ab, "rx monitor status with invalid buf_id %d\n",
                                            buf_id);
-                               spin_unlock_bh(&rx_ring->idr_lock);
                                pmon->buf_state = DP_MON_STATUS_REPLINISH;
                                goto move_next;
                        }
 
-                       idr_remove(&rx_ring->bufs_idr, buf_id);
-                       spin_unlock_bh(&rx_ring->idr_lock);
-
                        rxcb = ATH11K_SKB_RXCB(skb);
 
-                       dma_unmap_single(ab->dev, rxcb->paddr,
-                                        skb->len + skb_tailroom(skb),
-                                        DMA_FROM_DEVICE);
+                       dma_sync_single_for_cpu(ab->dev, rxcb->paddr,
+                                               skb->len + skb_tailroom(skb),
+                                               DMA_FROM_DEVICE);
 
                        tlv = (struct hal_tlv_hdr *)skb->data;
                        if (FIELD_GET(HAL_TLV_HDR_TAG, tlv->tl) !=
                                        HAL_RX_STATUS_BUFFER_DONE) {
-                               ath11k_warn(ab, "mon status DONE not set %lx\n",
+                               ath11k_warn(ab, "mon status DONE not set %lx, buf_id %d\n",
                                            FIELD_GET(HAL_TLV_HDR_TAG,
-                                                     tlv->tl));
-                               dev_kfree_skb_any(skb);
+                                                     tlv->tl), buf_id);
+                               /* If done status is missing, hold onto status
+                                * ring until status is done for this status
+                                * ring buffer.
+                                * Keep HP in mon_status_ring unchanged,
+                                * and break from here.
+                                * Check status for same buffer for next time
+                                */
                                pmon->buf_state = DP_MON_STATUS_NO_DMA;
-                               goto move_next;
+                               break;
                        }
 
+                       spin_lock_bh(&rx_ring->idr_lock);
+                       idr_remove(&rx_ring->bufs_idr, buf_id);
+                       spin_unlock_bh(&rx_ring->idr_lock);
                        if (ab->hw_params.full_monitor_mode) {
                                ath11k_dp_rx_mon_update_status_buf_state(pmon, tlv);
                                if (paddr == pmon->mon_status_paddr)
                                        pmon->buf_state = DP_MON_STATUS_MATCH;
                        }
+
+                       dma_unmap_single(ab->dev, rxcb->paddr,
+                                        skb->len + skb_tailroom(skb),
+                                        DMA_FROM_DEVICE);
+
                        __skb_queue_tail(skb_list, skb);
                } else {
                        pmon->buf_state = DP_MON_STATUS_REPLINISH;