qcacmn: Memory stats for SKB usage and Tx desc cnt in datapath

Add sysfs node for DP level memory stats:
/sys/kernel/wifi/wlan/wlan_dp_mem_stats
These include Tx, Rx SKB memory allocated, Tx/Rx
buffer count, outstanding Tx desc count.

Change-Id: I839a5f2ec4e763ca11cdea2093368ca6dc52d8cf
CRs-Fixed: 2724460

dp/wifi3.0/dp_tx.c

@@ -74,6 +74,34 @@ static const uint8_t sec_type_map[MAX_CDP_SEC_TYPE] = {
 					HAL_TX_ENCRYPT_TYPE_AES_GCMP_256,
 					HAL_TX_ENCRYPT_TYPE_WAPI_GCM_SM4};
 
+#ifdef CONFIG_WLAN_SYSFS_MEM_STATS
+/**
+ * dp_update_tx_desc_stats - Update the increase or decrease in
+ * outstanding tx desc count
+ * values on pdev and soc
+ * @vdev: DP pdev handle
+ *
+ * Return: void
+ */
+static inline void
+dp_update_tx_desc_stats(struct dp_pdev *pdev)
+{
+	int32_t tx_descs_cnt =
+		qdf_atomic_read(&pdev->num_tx_outstanding);
+	if (pdev->tx_descs_max < tx_descs_cnt)
+		pdev->tx_descs_max = tx_descs_cnt;
+	qdf_mem_tx_desc_cnt_update(pdev->num_tx_outstanding,
+				   pdev->tx_descs_max);
+}
+
+#else /* CONFIG_WLAN_SYSFS_MEM_STATS */
+
+static inline void
+dp_update_tx_desc_stats(struct dp_pdev *pdev)
+{
+}
+#endif /* CONFIG_WLAN_SYSFS_MEM_STATS */
+
 #ifdef QCA_TX_LIMIT_CHECK
 /**
  * dp_tx_limit_check - Check if allocated tx descriptors reached
@@ -146,6 +174,7 @@ dp_tx_outstanding_inc(struct dp_pdev *pdev)
 
 	qdf_atomic_inc(&pdev->num_tx_outstanding);
 	qdf_atomic_inc(&soc->num_tx_outstanding);
+	dp_update_tx_desc_stats(pdev);
 }
 
 /**
@@ -161,6 +190,7 @@ dp_tx_outstanding_dec(struct dp_pdev *pdev)
 
 	qdf_atomic_dec(&pdev->num_tx_outstanding);
 	qdf_atomic_dec(&soc->num_tx_outstanding);
+	dp_update_tx_desc_stats(pdev);
 }
 
 #else //QCA_TX_LIMIT_CHECK
@@ -180,12 +210,14 @@ static inline void
 dp_tx_outstanding_inc(struct dp_pdev *pdev)
 {
 	qdf_atomic_inc(&pdev->num_tx_outstanding);
+	dp_update_tx_desc_stats(pdev);
 }
 
 static inline void
 dp_tx_outstanding_dec(struct dp_pdev *pdev)
 {
 	qdf_atomic_dec(&pdev->num_tx_outstanding);
+	dp_update_tx_desc_stats(pdev);
 }
 #endif //QCA_TX_LIMIT_CHECK
 
@@ -5034,7 +5066,7 @@ QDF_STATUS dp_tx_pdev_init(struct dp_pdev *pdev)
 
 	/* Initialize Flow control counters */
 	qdf_atomic_init(&pdev->num_tx_outstanding);
-
+	pdev->tx_descs_max = 0;
 	if (wlan_cfg_per_pdev_tx_ring(soc->wlan_cfg_ctx)) {
 		/* Initialize descriptors in TCL Ring */
 		hal_tx_init_data_ring(soc->hal_soc,