qcacld-3.0: Add ref_cnt implementation for flow pool

Add ref_cnt implementation for flow pool to synchronize
usage and deletion of flow pool.

Change-Id: Idb52c74df6a771b776e3df6bf4aea5c150b5fc7a
CRs-Fixed: 2025757

3 files changed, 192 insertions, 96 deletions

diff --git a/core/dp/ol/inc/ol_txrx_ctrl_api.h b/core/dp/ol/inc/ol_txrx_ctrl_api.h
index a9fdf25b097c..ab55ac39dc22 100644
--- a/core/dp/ol/inc/ol_txrx_ctrl_api.h
+++ b/core/dp/ol/inc/ol_txrx_ctrl_api.h
@@ -642,7 +642,33 @@ void ol_tx_flow_pool_unmap_handler(uint8_t flow_id, uint8_t flow_type,
 				   uint8_t flow_pool_id);
 struct ol_tx_flow_pool_t *ol_tx_create_flow_pool(uint8_t flow_pool_id,
 						 uint16_t flow_pool_size);
-int ol_tx_delete_flow_pool(struct ol_tx_flow_pool_t *pool, bool force);
+
+/**
+ * ol_tx_inc_pool_ref() - increment pool ref count
+ * @pool: flow pool pointer
+ *
+ * Increments pool's ref count, used to make sure that no one is using
+ * pool when it is being deleted.
+ * As this function is taking pool->flow_pool_lock inside it, it should
+ * always be called outside this spinlock.
+ *
+ * Return: QDF_STATUS_SUCCESS - in case of success
+ */
+QDF_STATUS ol_tx_inc_pool_ref(struct ol_tx_flow_pool_t *pool);
+
+/**
+ * ol_tx_dec_pool_ref() - decrement pool ref count
+ * @pool: flow pool pointer
+ * @force: free pool forcefully
+ *
+ * Decrements pool's ref count and deletes the pool if ref count gets 0.
+ * As this function is taking pdev->tx_desc.flow_pool_list_lock and
+ * pool->flow_pool_lock inside it, it should always be called outside
+ * these two spinlocks.
+ *
+ * Return: QDF_STATUS_SUCCESS - in case of success
+ */
+QDF_STATUS ol_tx_dec_pool_ref(struct ol_tx_flow_pool_t *pool, bool force);
 #else
 
 static inline void ol_tx_register_flow_control(struct ol_txrx_pdev_t *pdev)
@@ -676,10 +702,15 @@ static inline struct ol_tx_flow_pool_t *ol_tx_create_flow_pool(
 {
 	return NULL;
 }
-static inline int ol_tx_delete_flow_pool(struct ol_tx_flow_pool_t *pool,
-		bool force)
+static inline QDF_STATUS
+ol_tx_inc_pool_ref(struct ol_tx_flow_pool_t *pool)
+{
+	return QDF_STATUS_SUCCESS;
+}
+static inline QDF_STATUS
+ol_tx_dec_pool_ref(struct ol_tx_flow_pool_t *pool, bool force)
 {
-	return 0;
+	return QDF_STATUS_SUCCESS;
 }
 #endif
 
diff --git a/core/dp/txrx/ol_txrx_flow_control.c b/core/dp/txrx/ol_txrx_flow_control.c
index 7ce33d6e558e..826697cfbab7 100644
--- a/core/dp/txrx/ol_txrx_flow_control.c
+++ b/core/dp/txrx/ol_txrx_flow_control.c
@@ -81,7 +81,7 @@ ol_tx_register_global_mgmt_pool(struct ol_txrx_pdev_t *pdev)
 static void
 ol_tx_deregister_global_mgmt_pool(struct ol_txrx_pdev_t *pdev)
 {
-	ol_tx_delete_flow_pool(pdev->mgmt_pool, false);
+	ol_tx_dec_pool_ref(pdev->mgmt_pool, false);
 	return;
 }
 #else
@@ -135,7 +135,7 @@ void ol_tx_deregister_flow_control(struct ol_txrx_pdev_t *pdev)
 		ol_txrx_info("flow pool list is not empty %d!!!\n", i++);
 		if (i == 1)
 			ol_tx_dump_flow_pool_info();
-		ol_tx_delete_flow_pool(pool, true);
+		ol_tx_dec_pool_ref(pool, true);
 		qdf_spin_lock_bh(&pdev->tx_desc.flow_pool_list_lock);
 	}
 	qdf_spin_unlock_bh(&pdev->tx_desc.flow_pool_list_lock);
@@ -143,6 +143,138 @@ void ol_tx_deregister_flow_control(struct ol_txrx_pdev_t *pdev)
 }
 
 /**
+ * ol_tx_delete_flow_pool() - delete flow pool
+ * @pool: flow pool pointer
+ * @force: free pool forcefully
+ *
+ * Delete flow_pool if all tx descriptors are available.
+ * Otherwise put it in FLOW_POOL_INVALID state.
+ * If force is set then pull all available descriptors to
+ * global pool.
+ *
+ * Return: 0 for success or error
+ */
+static int ol_tx_delete_flow_pool(struct ol_tx_flow_pool_t *pool, bool force)
+{
+	struct ol_txrx_pdev_t *pdev = cds_get_context(QDF_MODULE_ID_TXRX);
+	uint16_t i, size;
+	union ol_tx_desc_list_elem_t *temp_list = NULL;
+	struct ol_tx_desc_t *tx_desc = NULL;
+
+	if (!pool) {
+		ol_txrx_err(
+		   "%s: pool is NULL\n", __func__);
+		QDF_ASSERT(0);
+		return -ENOMEM;
+	}
+	if (!pdev) {
+		ol_txrx_err(
+		   "%s: pdev is NULL\n", __func__);
+		QDF_ASSERT(0);
+		return -ENOMEM;
+	}
+
+	qdf_spin_lock_bh(&pool->flow_pool_lock);
+	if (pool->avail_desc == pool->flow_pool_size || force == true)
+		pool->status = FLOW_POOL_INACTIVE;
+	else
+		pool->status = FLOW_POOL_INVALID;
+
+	/* Take all free descriptors and put it in temp_list */
+	temp_list = pool->freelist;
+	size = pool->avail_desc;
+	pool->freelist = NULL;
+	pool->avail_desc = 0;
+
+	if (pool->status == FLOW_POOL_INACTIVE) {
+		qdf_spin_unlock_bh(&pool->flow_pool_lock);
+		/* Free flow_pool */
+		qdf_spinlock_destroy(&pool->flow_pool_lock);
+		qdf_mem_free(pool);
+	} else { /* FLOW_POOL_INVALID case*/
+		pool->flow_pool_size -= size;
+		pool->flow_pool_id = INVALID_FLOW_ID;
+		qdf_spin_unlock_bh(&pool->flow_pool_lock);
+		ol_tx_inc_pool_ref(pool);
+
+		pdev->tx_desc.num_invalid_bin++;
+		ol_txrx_info(
+			"%s: invalid pool created %d\n",
+			 __func__, pdev->tx_desc.num_invalid_bin);
+		if (pdev->tx_desc.num_invalid_bin > MAX_INVALID_BIN)
+			ASSERT(0);
+
+		qdf_spin_lock_bh(&pdev->tx_desc.flow_pool_list_lock);
+		TAILQ_INSERT_TAIL(&pdev->tx_desc.flow_pool_list, pool,
+				 flow_pool_list_elem);
+		qdf_spin_unlock_bh(&pdev->tx_desc.flow_pool_list_lock);
+	}
+
+	/* put free descriptors to global pool */
+	qdf_spin_lock_bh(&pdev->tx_mutex);
+	for (i = 0; i < size; i++) {
+		tx_desc = &temp_list->tx_desc;
+		temp_list = temp_list->next;
+
+		ol_tx_put_desc_global_pool(pdev, tx_desc);
+	}
+	qdf_spin_unlock_bh(&pdev->tx_mutex);
+
+	return 0;
+}
+
+QDF_STATUS ol_tx_inc_pool_ref(struct ol_tx_flow_pool_t *pool)
+{
+	if (!pool) {
+		ol_txrx_err("flow pool is NULL");
+		return QDF_STATUS_E_INVAL;
+	}
+
+	qdf_spin_lock_bh(&pool->flow_pool_lock);
+	qdf_atomic_inc(&pool->ref_cnt);
+	qdf_spin_unlock_bh(&pool->flow_pool_lock);
+	ol_txrx_dbg("pool %p, ref_cnt %x",
+		    pool, qdf_atomic_read(&pool->ref_cnt));
+
+	return  QDF_STATUS_SUCCESS;
+}
+
+QDF_STATUS ol_tx_dec_pool_ref(struct ol_tx_flow_pool_t *pool, bool force)
+{
+	struct ol_txrx_pdev_t *pdev = cds_get_context(QDF_MODULE_ID_TXRX);
+
+	if (!pool) {
+		ol_txrx_err("flow pool is NULL");
+		QDF_ASSERT(0);
+		return QDF_STATUS_E_INVAL;
+	}
+
+	if (!pdev) {
+		ol_txrx_err("pdev is NULL");
+		QDF_ASSERT(0);
+		return QDF_STATUS_E_INVAL;
+	}
+
+	qdf_spin_lock_bh(&pdev->tx_desc.flow_pool_list_lock);
+	qdf_spin_lock_bh(&pool->flow_pool_lock);
+	if (qdf_atomic_dec_and_test(&pool->ref_cnt)) {
+		qdf_spin_unlock_bh(&pool->flow_pool_lock);
+		TAILQ_REMOVE(&pdev->tx_desc.flow_pool_list, pool,
+			     flow_pool_list_elem);
+		qdf_spin_unlock_bh(&pdev->tx_desc.flow_pool_list_lock);
+		ol_txrx_dbg("Deleting pool %p", pool);
+		ol_tx_delete_flow_pool(pool, force);
+	} else {
+		qdf_spin_unlock_bh(&pool->flow_pool_lock);
+		qdf_spin_unlock_bh(&pdev->tx_desc.flow_pool_list_lock);
+		ol_txrx_dbg("pool %p, ref_cnt %x",
+			    pool, qdf_atomic_read(&pool->ref_cnt));
+	}
+
+	return  QDF_STATUS_SUCCESS;
+}
+
+/**
  * ol_tx_dump_flow_pool_info() - dump global_pool and flow_pool info
  *
  * Return: none
@@ -150,7 +282,7 @@ void ol_tx_deregister_flow_control(struct ol_txrx_pdev_t *pdev)
 void ol_tx_dump_flow_pool_info(void)
 {
 	struct ol_txrx_pdev_t *pdev = cds_get_context(QDF_MODULE_ID_TXRX);
-	struct ol_tx_flow_pool_t *pool = NULL;
+	struct ol_tx_flow_pool_t *pool = NULL, *pool_prev = NULL;
 	struct ol_tx_flow_pool_t tmp_pool;
 
 
@@ -180,10 +312,15 @@ void ol_tx_dump_flow_pool_info(void)
 	qdf_spin_lock_bh(&pdev->tx_desc.flow_pool_list_lock);
 	TAILQ_FOREACH(pool, &pdev->tx_desc.flow_pool_list,
 					 flow_pool_list_elem) {
+		ol_tx_inc_pool_ref(pool);
 		qdf_spin_lock_bh(&pool->flow_pool_lock);
 		qdf_mem_copy(&tmp_pool, pool, sizeof(tmp_pool));
 		qdf_spin_unlock_bh(&pool->flow_pool_lock);
 		qdf_spin_unlock_bh(&pdev->tx_desc.flow_pool_list_lock);
+
+		if (pool_prev)
+			ol_tx_dec_pool_ref(pool_prev, false);
+
 		ol_txrx_info("\n");
 		ol_txrx_info(
 			"Flow_pool_id %d :: status %d",
@@ -201,10 +338,16 @@ void ol_tx_dump_flow_pool_info(void)
 		ol_txrx_info(
 			"Pkt dropped due to unavailablity of descriptors %d",
 			tmp_pool.pkt_drop_no_desc);
+
+		pool_prev = pool;
 		qdf_spin_lock_bh(&pdev->tx_desc.flow_pool_list_lock);
 	}
 	qdf_spin_unlock_bh(&pdev->tx_desc.flow_pool_list_lock);
 
+	/* decrement ref count for last pool in list */
+	if (pool_prev)
+		ol_tx_dec_pool_ref(pool_prev, false);
+
 	return;
 }
 
@@ -373,6 +516,8 @@ struct ol_tx_flow_pool_t *ol_tx_create_flow_pool(uint8_t flow_pool_id,
 	pool->start_th = (start_threshold * flow_pool_size)/100;
 	pool->stop_th = (stop_threshold * flow_pool_size)/100;
 	qdf_spinlock_create(&pool->flow_pool_lock);
+	qdf_atomic_init(&pool->ref_cnt);
+	ol_tx_inc_pool_ref(pool);
 
 	/* Take TX descriptor from global_pool and put it in temp_list*/
 	qdf_spin_lock_bh(&pdev->tx_mutex);
@@ -405,91 +550,6 @@ struct ol_tx_flow_pool_t *ol_tx_create_flow_pool(uint8_t flow_pool_id,
 }
 
 /**
- * ol_tx_delete_flow_pool() - delete flow pool
- * @pool: flow pool pointer
- * @force: free pool forcefully
- *
- * Delete flow_pool if all tx descriptors are available.
- * Otherwise put it in FLOW_POOL_INVALID state.
- * If force is set then pull all available descriptors to
- * global pool.
- *
- * Return: 0 for success or error
- */
-int ol_tx_delete_flow_pool(struct ol_tx_flow_pool_t *pool, bool force)
-{
-	struct ol_txrx_pdev_t *pdev = cds_get_context(QDF_MODULE_ID_TXRX);
-	uint16_t i, size;
-	union ol_tx_desc_list_elem_t *temp_list = NULL;
-	struct ol_tx_desc_t *tx_desc = NULL;
-
-	if (!pool) {
-		ol_txrx_err(
-		   "%s: pool is NULL\n", __func__);
-		QDF_ASSERT(0);
-		return -ENOMEM;
-	}
-	if (!pdev) {
-		ol_txrx_err(
-		   "%s: pdev is NULL\n", __func__);
-		QDF_ASSERT(0);
-		return -ENOMEM;
-	}
-
-	qdf_spin_lock_bh(&pdev->tx_desc.flow_pool_list_lock);
-	TAILQ_REMOVE(&pdev->tx_desc.flow_pool_list, pool, flow_pool_list_elem);
-	qdf_spin_unlock_bh(&pdev->tx_desc.flow_pool_list_lock);
-
-	qdf_spin_lock_bh(&pool->flow_pool_lock);
-	if (pool->avail_desc == pool->flow_pool_size || force == true)
-		pool->status = FLOW_POOL_INACTIVE;
-	else
-		pool->status = FLOW_POOL_INVALID;
-
-	/* Take all free descriptors and put it in temp_list */
-	temp_list = pool->freelist;
-	size = pool->avail_desc;
-	pool->freelist = NULL;
-	pool->avail_desc = 0;
-
-	if (pool->status == FLOW_POOL_INACTIVE) {
-		qdf_spin_unlock_bh(&pool->flow_pool_lock);
-		/* Free flow_pool */
-		qdf_spinlock_destroy(&pool->flow_pool_lock);
-		qdf_mem_free(pool);
-	} else { /* FLOW_POOL_INVALID case*/
-		pool->flow_pool_size -= size;
-		pool->flow_pool_id = INVALID_FLOW_ID;
-		qdf_spin_unlock_bh(&pool->flow_pool_lock);
-
-		pdev->tx_desc.num_invalid_bin++;
-		ol_txrx_info(
-			"%s: invalid pool created %d\n",
-			 __func__, pdev->tx_desc.num_invalid_bin);
-		if (pdev->tx_desc.num_invalid_bin > MAX_INVALID_BIN)
-			ASSERT(0);
-
-		qdf_spin_lock_bh(&pdev->tx_desc.flow_pool_list_lock);
-		TAILQ_INSERT_TAIL(&pdev->tx_desc.flow_pool_list, pool,
-				 flow_pool_list_elem);
-		qdf_spin_unlock_bh(&pdev->tx_desc.flow_pool_list_lock);
-	}
-
-	/* put free descriptors to global pool */
-	qdf_spin_lock_bh(&pdev->tx_mutex);
-	for (i = 0; i < size; i++) {
-		tx_desc = &temp_list->tx_desc;
-		temp_list = temp_list->next;
-
-		ol_tx_put_desc_global_pool(pdev, tx_desc);
-	}
-	qdf_spin_unlock_bh(&pdev->tx_mutex);
-
-	return 0;
-}
-
-
-/**
  * ol_tx_free_invalid_flow_pool() - free invalid pool
  * @pool: pool
  *
@@ -517,7 +577,7 @@ int ol_tx_free_invalid_flow_pool(struct ol_tx_flow_pool_t *pool)
 		"%s: invalid pool deleted %d\n",
 		 __func__, pdev->tx_desc.num_invalid_bin);
 
-	return ol_tx_delete_flow_pool(pool, false);
+	return ol_tx_dec_pool_ref(pool, false);
 }
 
 /**
@@ -670,7 +730,7 @@ void ol_tx_flow_pool_map_handler(uint8_t flow_id, uint8_t flow_type,
 		break;
 	default:
 		if (pool_create)
-			ol_tx_delete_flow_pool(pool, false);
+			ol_tx_dec_pool_ref(pool, false);
 		ol_txrx_err(
 		   "%s: flow type %d not supported !!!\n",
 		   __func__, type);
@@ -729,8 +789,11 @@ void ol_tx_flow_pool_unmap_handler(uint8_t flow_id, uint8_t flow_type,
 		return;
 	}
 
-	/* only delete if all descriptors are available */
-	ol_tx_delete_flow_pool(pool, false);
+	/*
+	 * only delete if all descriptors are available
+	 * and pool ref count becomes 0
+	 */
+	ol_tx_dec_pool_ref(pool, false);
 
 	return;
 }
diff --git a/core/dp/txrx/ol_txrx_types.h b/core/dp/txrx/ol_txrx_types.h
index 2668d898c4fa..c7c21073d00c 100644
--- a/core/dp/txrx/ol_txrx_types.h
+++ b/core/dp/txrx/ol_txrx_types.h
@@ -475,6 +475,7 @@ struct ol_txrx_pool_stats {
  * @start_th: start threshold
  * @freelist: tx descriptor freelist
  * @pkt_drop_no_desc: drop due to no descriptors
+ * @ref_cnt: pool's ref count
  */
 struct ol_tx_flow_pool_t {
 	TAILQ_ENTRY(ol_tx_flow_pool_t) flow_pool_list_elem;
@@ -490,6 +491,7 @@ struct ol_tx_flow_pool_t {
 	uint16_t start_th;
 	union ol_tx_desc_list_elem_t *freelist;
 	uint16_t pkt_drop_no_desc;
+	qdf_atomic_t ref_cnt;
 };
 
 #endif