nvethernet: delete old skb for tx TS

Remove SKB for which HW timestamps are not present

Bug 3647934

Change-Id: Ib3a5ca6275f74425f4fe43a87ea6696823aedd96
Signed-off-by: Rakesh Goyal <rgoyal@nvidia.com>
Reviewed-on: https://git-master.nvidia.com/r/c/linux-nvidia/+/2716400
Reviewed-by: Bharat Nihalani <bnihalani@nvidia.com>
Reviewed-by: svc_kernel_abi <svc_kernel_abi@nvidia.com>
GVS: Gerrit_Virtual_Submit

drivers/net/ethernet/nvidia/nvethernet/ether_linux.h

@@ -130,6 +130,11 @@
  */
 #define TS_MISS_THRESHOLD		200U
 
+/**
+ * @brief SEC to MSEC converter
+ */
+#define ETHER_SECTOMSEC			1000U
+
 /**
  * @brief Ethernet clk rates
  */
@@ -388,6 +393,8 @@ struct ether_tx_ts_skb_list {
 	struct sk_buff *skb;
 	/** packet id to identify timestamp */
 	unsigned int pktid;
+	/** SKB jiffies to find time */
+	unsigned long pkt_jiffies;
 };
 
 /**

drivers/net/ethernet/nvidia/nvethernet/osd.c

@@ -16,6 +16,84 @@
 
 #include "ether_linux.h"
 
+/**
+ * @brief ether_get_free_tx_ts_node - get free node for pending SKB
+ *
+ * Algorithm:
+ *  - Find index of statically allocayted free memory for pending SKB
+ *
+ * @param[in] pdata: OSD private data structure.
+ *
+ * @retval index number
+ */
+static inline unsigned int ether_get_free_tx_ts_node(struct ether_priv_data *pdata)
+{
+	unsigned int i;
+
+	for (i = 0; i < ETHER_MAX_PENDING_SKB_CNT; i++) {
+		if (pdata->tx_ts_skb[i].in_use == OSI_NONE) {
+			break;
+		}
+	}
+
+	return i;
+}
+
+static inline void add_skb_node(struct ether_priv_data *pdata, struct sk_buff *skb,
+				unsigned int pktid) {
+	struct list_head *head_node, *temp_head_node;
+	struct ether_tx_ts_skb_list *pnode = NULL;
+	unsigned int idx;
+	unsigned long flags;
+	unsigned long now_jiffies = jiffies;
+
+	if (list_empty(&pdata->tx_ts_skb_head)) {
+		goto empty;
+	}
+
+	raw_spin_lock_irqsave(&pdata->txts_lock, flags);
+	list_for_each_safe(head_node, temp_head_node,
+			   &pdata->tx_ts_skb_head) {
+		pnode = list_entry(head_node,
+				   struct ether_tx_ts_skb_list,
+				   list_head);
+
+		if ((jiffies_to_msecs(now_jiffies) - jiffies_to_msecs(pnode->pkt_jiffies))
+		     >= ETHER_SECTOMSEC) {
+			dev_dbg(pdata->dev, "%s() skb %p deleting for pktid = %x time=%lu\n",
+				__func__, pnode->skb, pnode->pktid, pnode->pkt_jiffies);
+			if (pnode->skb != NULL) {
+				dev_consume_skb_any(pnode->skb);
+			}
+			list_del(head_node);
+			pnode->in_use = OSI_DISABLE;
+		}
+	}
+	raw_spin_unlock_irqrestore(&pdata->txts_lock, flags);
+empty:
+	raw_spin_lock_irqsave(&pdata->txts_lock, flags);
+	idx = ether_get_free_tx_ts_node(pdata);
+	if (idx == ETHER_MAX_PENDING_SKB_CNT) {
+		dev_dbg(pdata->dev,
+			"No free node to store pending SKB\n");
+		dev_consume_skb_any(skb);
+		raw_spin_unlock_irqrestore(&pdata->txts_lock, flags);
+		return;
+	}
+
+	pdata->tx_ts_skb[idx].in_use = OSI_ENABLE;
+	pnode = &pdata->tx_ts_skb[idx];
+	pnode->skb = skb;
+	pnode->pktid = pktid;
+	pnode->pkt_jiffies = now_jiffies;
+
+	dev_dbg(pdata->dev, "%s() SKB %p added for pktid = %x time=%lu\n",
+		__func__, skb, pktid, pnode->pkt_jiffies);
+	list_add_tail(&pnode->list_head,
+		      &pdata->tx_ts_skb_head);
+	raw_spin_unlock_irqrestore(&pdata->txts_lock, flags);
+}
+
 /**
  * @brief Adds delay in micro seconds.
  *
@@ -650,29 +728,6 @@ done:
 		ether_realloc_rx_skb(pdata, rx_ring, chan);
 }
 
-/**
- * @brief ether_get_free_tx_ts_node - get free node for pending SKB
- *
- * Algorithm:
- *  - Find index of statically allocayted free memory for pending SKB
- *
- * @param[in] pdata: OSD private data structure.
- *
- * @retval index number
- */
-static inline unsigned int ether_get_free_tx_ts_node(struct ether_priv_data *pdata)
-{
-	unsigned int i;
-
-	for (i = 0; i < ETHER_MAX_PENDING_SKB_CNT; i++) {
-		if (pdata->tx_ts_skb[i].in_use == OSI_NONE) {
-			break;
-		}
-	}
-
-	return i;
-}
-
 /**
  * @brief osd_transmit_complete - Transmit completion routine.
  *
@@ -702,9 +757,7 @@ static void osd_transmit_complete(void *priv, const struct osi_tx_swcx *swcx,
 	struct osi_tx_ring *tx_ring;
 	struct netdev_queue *txq;
 	unsigned int chan, qinx;
-	unsigned int idx;
 	unsigned int len = swcx->len;
-	unsigned long flags;
 
 	ndev->stats.tx_bytes += len;
 
@@ -745,28 +798,7 @@ static void osd_transmit_complete(void *priv, const struct osi_tx_swcx *swcx,
 		ndev->stats.tx_packets++;
 		if ((txdone_pkt_cx->flags & OSI_TXDONE_CX_TS_DELAYED) ==
 		    OSI_TXDONE_CX_TS_DELAYED) {
-			struct ether_tx_ts_skb_list *pnode = NULL;
+			add_skb_node(pdata, skb, txdone_pkt_cx->pktid);
-
-			raw_spin_lock_irqsave(&pdata->txts_lock, flags);
-			idx = ether_get_free_tx_ts_node(pdata);
-			if (idx == ETHER_MAX_PENDING_SKB_CNT) {
-				dev_dbg(pdata->dev,
-					"No free node to store pending SKB\n");
-				dev_consume_skb_any(skb);
-				raw_spin_unlock_irqrestore(&pdata->txts_lock, flags);
-				return;
-			}
-
-			pdata->tx_ts_skb[idx].in_use = OSI_ENABLE;
-			pnode = &pdata->tx_ts_skb[idx];
-			pnode->skb = skb;
-			pnode->pktid = txdone_pkt_cx->pktid;
-
-			dev_dbg(pdata->dev, "SKB %p added for pktid = %d\n",
-				skb, txdone_pkt_cx->pktid);
-			list_add_tail(&pnode->list_head,
-				      &pdata->tx_ts_skb_head);
-			raw_spin_unlock_irqrestore(&pdata->txts_lock, flags);
 			schedule_delayed_work(&pdata->tx_ts_work,
 					      msecs_to_jiffies(ETHER_TS_MS_TIMER));
 		} else {