iwlagn: add an API to free the TX context

Tx free functions move to the transport layer. Unify the functions that deal with tx queues and cmd queue.

Since the CMD queue is not fully allocated, but uses the q->n_bd / q->window trick, the release flow of TX queue and CMD queue was different.
iwlagn_txq_free_tfd receives now the index of the TFD to be freed, which allows to unify the release flow for all the queues.
Signed-off-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com>
Signed-off-by: Wey-Yi Guy <wey-yi.w.guy@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

drivers/net/wireless/iwlwifi/iwl-agn-tx.c

@@ -851,31 +851,6 @@ static inline void iwlagn_free_dma_ptr(struct iwl_priv *priv,
 	memset(ptr, 0, sizeof(*ptr));
 }
 
-/**
- * iwlagn_hw_txq_ctx_free - Free TXQ Context
- *
- * Destroy all TX DMA queues and structures
- */
-void iwlagn_hw_txq_ctx_free(struct iwl_priv *priv)
-{
-	int txq_id;
-
-	/* Tx queues */
-	if (priv->txq) {
-		for (txq_id = 0; txq_id < priv->hw_params.max_txq_num; txq_id++)
-			if (txq_id == priv->cmd_queue)
-				iwl_cmd_queue_free(priv);
-			else
-				iwl_tx_queue_free(priv, txq_id);
-	}
-	iwlagn_free_dma_ptr(priv, &priv->kw);
-
-	iwlagn_free_dma_ptr(priv, &priv->scd_bc_tbls);
-
-	/* free tx queue structure */
-	iwl_free_txq_mem(priv);
-}
-
 /**
  * iwlagn_txq_ctx_stop - Stop all Tx DMA channels
  */
@@ -906,10 +881,7 @@ void iwlagn_txq_ctx_stop(struct iwl_priv *priv)
 
 	/* Unmap DMA from host system and free skb's */
 	for (txq_id = 0; txq_id < priv->hw_params.max_txq_num; txq_id++)
-		if (txq_id == priv->cmd_queue)
-			iwl_cmd_queue_unmap(priv);
-		else
-			iwl_tx_queue_unmap(priv, txq_id);
+		iwl_tx_queue_unmap(priv, txq_id);
 }
 
 /*
@@ -1170,7 +1142,7 @@ int iwlagn_tx_queue_reclaim(struct iwl_priv *priv, int txq_id, int index)
 
 		iwlagn_txq_inval_byte_cnt_tbl(priv, txq);
 
-		iwlagn_txq_free_tfd(priv, txq);
+		iwlagn_txq_free_tfd(priv, txq, txq->q.read_ptr);
 	}
 	return nfreed;
 }

drivers/net/wireless/iwlwifi/iwl-agn.c

@@ -3710,7 +3710,7 @@ void __devexit iwl_remove(struct iwl_priv * priv)
 	iwl_dealloc_ucode(priv);
 
 	priv->trans.ops->rx_free(priv);
-	iwlagn_hw_txq_ctx_free(priv);
+	priv->trans.ops->tx_free(priv);
 
 	iwl_eeprom_free(priv);
 

drivers/net/wireless/iwlwifi/iwl-agn.h

@@ -198,7 +198,8 @@ int iwlagn_hwrate_to_mac80211_idx(u32 rate_n_flags, enum ieee80211_band band);
 void iwl_setup_rx_handlers(struct iwl_priv *priv);
 
 /* tx */
-void iwlagn_txq_free_tfd(struct iwl_priv *priv, struct iwl_tx_queue *txq);
+void iwlagn_txq_free_tfd(struct iwl_priv *priv, struct iwl_tx_queue *txq,
+				int index);
 int iwlagn_txq_attach_buf_to_tfd(struct iwl_priv *priv,
 				 struct iwl_tx_queue *txq,
 				 dma_addr_t addr, u16 len, u8 reset);
@@ -217,7 +218,6 @@ int iwlagn_txq_check_empty(struct iwl_priv *priv,
 void iwlagn_rx_reply_compressed_ba(struct iwl_priv *priv,
 				struct iwl_rx_mem_buffer *rxb);
 int iwlagn_tx_queue_reclaim(struct iwl_priv *priv, int txq_id, int index);
-void iwlagn_hw_txq_ctx_free(struct iwl_priv *priv);
 void iwlagn_txq_ctx_stop(struct iwl_priv *priv);
 
 static inline u32 iwl_tx_status_to_mac80211(u32 status)

drivers/net/wireless/iwlwifi/iwl-core.c

@@ -1370,12 +1370,6 @@ void iwl_mac_remove_interface(struct ieee80211_hw *hw,
 
 }
 
-void iwl_free_txq_mem(struct iwl_priv *priv)
-{
-	kfree(priv->txq);
-	priv->txq = NULL;
-}
-
 #ifdef CONFIG_IWLWIFI_DEBUGFS
 
 #define IWL_TRAFFIC_DUMP_SIZE	(IWL_TRAFFIC_ENTRY_SIZE * IWL_TRAFFIC_ENTRIES)

drivers/net/wireless/iwlwifi/iwl-core.h

@@ -328,8 +328,6 @@ void iwl_mac_remove_interface(struct ieee80211_hw *hw,
 int iwl_mac_change_interface(struct ieee80211_hw *hw,
 			     struct ieee80211_vif *vif,
 			     enum nl80211_iftype newtype, bool newp2p);
-void iwl_free_txq_mem(struct iwl_priv *priv);
-
 #ifdef CONFIG_IWLWIFI_DEBUGFS
 int iwl_alloc_traffic_mem(struct iwl_priv *priv);
 void iwl_free_traffic_mem(struct iwl_priv *priv);
@@ -371,8 +369,6 @@ static inline void iwl_update_stats(struct iwl_priv *priv, bool is_tx,
 /*****************************************************
 * RX
 ******************************************************/
-void iwl_cmd_queue_free(struct iwl_priv *priv);
-void iwl_cmd_queue_unmap(struct iwl_priv *priv);
 void iwl_rx_queue_update_write_ptr(struct iwl_priv *priv,
 				  struct iwl_rx_queue *q);
 int iwl_rx_queue_space(const struct iwl_rx_queue *q);
@@ -386,7 +382,6 @@ void iwl_chswitch_done(struct iwl_priv *priv, bool is_success);
 * TX
 ******************************************************/
 void iwl_txq_update_write_ptr(struct iwl_priv *priv, struct iwl_tx_queue *txq);
-void iwl_tx_queue_free(struct iwl_priv *priv, int txq_id);
 int iwl_queue_init(struct iwl_priv *priv, struct iwl_queue *q,
 			  int count, int slots_num, u32 id);
 void iwl_tx_queue_unmap(struct iwl_priv *priv, int txq_id);

drivers/net/wireless/iwlwifi/iwl-dev.h

@@ -1233,11 +1233,14 @@ struct iwl_trans;
  * @rx_init: inits the rx memory, allocate it if needed
  * @rx_free: frees the rx memory
  * @tx_init:inits the tx memory, allocate if needed
+ * @tx_free: frees the tx memory
  */
 struct iwl_trans_ops {
 	int (*rx_init)(struct iwl_priv *priv);
 	void (*rx_free)(struct iwl_priv *priv);
+
 	int (*tx_init)(struct iwl_priv *priv);
+	void (*tx_free)(struct iwl_priv *priv);
 };
 
 struct iwl_trans {

drivers/net/wireless/iwlwifi/iwl-trans.c

@@ -203,6 +203,16 @@ static inline int iwlagn_alloc_dma_ptr(struct iwl_priv *priv,
 	return 0;
 }
 
+static inline void iwlagn_free_dma_ptr(struct iwl_priv *priv,
+				    struct iwl_dma_ptr *ptr)
+{
+	if (unlikely(!ptr->addr))
+		return;
+
+	dma_free_coherent(priv->bus.dev, ptr->size, ptr->addr, ptr->dma);
+	memset(ptr, 0, sizeof(*ptr));
+}
+
 static int iwl_trans_txq_alloc(struct iwl_priv *priv, struct iwl_tx_queue *txq,
 		      int slots_num, u32 txq_id)
 {
@@ -212,6 +222,8 @@ static int iwl_trans_txq_alloc(struct iwl_priv *priv, struct iwl_tx_queue *txq,
 	if (WARN_ON(txq->meta || txq->cmd || txq->txb || txq->tfds))
 		return -EINVAL;
 
+	txq->q.n_window = slots_num;
+
 	txq->meta = kzalloc(sizeof(txq->meta[0]) * slots_num,
 			    GFP_KERNEL);
 	txq->cmd = kzalloc(sizeof(txq->cmd[0]) * slots_num,
@@ -306,6 +318,72 @@ static int iwl_trans_txq_init(struct iwl_priv *priv, struct iwl_tx_queue *txq,
 	return 0;
 }
 
+/**
+ * iwl_tx_queue_free - Deallocate DMA queue.
+ * @txq: Transmit queue to deallocate.
+ *
+ * Empty queue by removing and destroying all BD's.
+ * Free all buffers.
+ * 0-fill, but do not free "txq" descriptor structure.
+ */
+static void iwl_tx_queue_free(struct iwl_priv *priv, int txq_id)
+{
+	struct iwl_tx_queue *txq = &priv->txq[txq_id];
+	struct device *dev = priv->bus.dev;
+	int i;
+	if (WARN_ON(!txq))
+		return;
+
+	iwl_tx_queue_unmap(priv, txq_id);
+
+	/* De-alloc array of command/tx buffers */
+	for (i = 0; i < txq->q.n_window; i++)
+		kfree(txq->cmd[i]);
+
+	/* De-alloc circular buffer of TFDs */
+	if (txq->q.n_bd) {
+		dma_free_coherent(dev, priv->hw_params.tfd_size *
+				  txq->q.n_bd, txq->tfds, txq->q.dma_addr);
+		memset(&txq->q.dma_addr, 0, sizeof(txq->q.dma_addr));
+	}
+
+	/* De-alloc array of per-TFD driver data */
+	kfree(txq->txb);
+	txq->txb = NULL;
+
+	/* deallocate arrays */
+	kfree(txq->cmd);
+	kfree(txq->meta);
+	txq->cmd = NULL;
+	txq->meta = NULL;
+
+	/* 0-fill queue descriptor structure */
+	memset(txq, 0, sizeof(*txq));
+}
+
+/**
+ * iwl_trans_tx_free - Free TXQ Context
+ *
+ * Destroy all TX DMA queues and structures
+ */
+static void iwl_trans_tx_free(struct iwl_priv *priv)
+{
+	int txq_id;
+
+	/* Tx queues */
+	if (priv->txq) {
+		for (txq_id = 0; txq_id < priv->hw_params.max_txq_num; txq_id++)
+			iwl_tx_queue_free(priv, txq_id);
+	}
+
+	kfree(priv->txq);
+	priv->txq = NULL;
+
+	iwlagn_free_dma_ptr(priv, &priv->kw);
+
+	iwlagn_free_dma_ptr(priv, &priv->scd_bc_tbls);
+}
+
 /**
  * iwl_trans_tx_alloc - allocate TX context
  * Allocate all Tx DMA structures and initialize them
@@ -362,7 +440,7 @@ static int iwl_trans_tx_alloc(struct iwl_priv *priv)
 	return 0;
 
 error:
-	iwlagn_hw_txq_ctx_free(priv);
+	priv->trans.ops->tx_free(priv);
 
 	return ret;
 }
@@ -406,7 +484,7 @@ static int iwl_trans_tx_init(struct iwl_priv *priv)
 error:
 	/*Upon error, free only if we allocated something */
 	if (alloc)
-		iwlagn_hw_txq_ctx_free(priv);
+		priv->trans.ops->tx_free(priv);
 	return ret;
 }
 
@@ -415,6 +493,7 @@ static const struct iwl_trans_ops trans_ops = {
 	.rx_free = iwl_trans_rx_free,
 
 	.tx_init = iwl_trans_tx_init,
+	.tx_free = iwl_trans_tx_free,
 };
 
 void iwl_trans_register(struct iwl_trans *trans)

drivers/net/wireless/iwlwifi/iwl-tx.c

@@ -157,14 +157,15 @@ static void iwlagn_unmap_tfd(struct iwl_priv *priv, struct iwl_cmd_meta *meta,
  * iwlagn_txq_free_tfd - Free all chunks referenced by TFD [txq->q.read_ptr]
  * @priv - driver private data
  * @txq - tx queue
+ * @index - the index of the TFD to be freed
  *
  * Does NOT advance any TFD circular buffer read/write indexes
  * Does NOT free the TFD itself (which is within circular buffer)
  */
-void iwlagn_txq_free_tfd(struct iwl_priv *priv, struct iwl_tx_queue *txq)
+void iwlagn_txq_free_tfd(struct iwl_priv *priv, struct iwl_tx_queue *txq,
+	int index)
 {
 	struct iwl_tfd *tfd_tmp = txq->tfds;
-	int index = txq->q.read_ptr;
 
 	iwlagn_unmap_tfd(priv, &txq->meta[index], &tfd_tmp[index],
 			 DMA_TO_DEVICE);
@@ -173,12 +174,12 @@ void iwlagn_txq_free_tfd(struct iwl_priv *priv, struct iwl_tx_queue *txq)
 	if (txq->txb) {
 		struct sk_buff *skb;
 
-		skb = txq->txb[txq->q.read_ptr].skb;
+		skb = txq->txb[index].skb;
 
 		/* can be called from irqs-disabled context */
 		if (skb) {
 			dev_kfree_skb_any(skb);
-			txq->txb[txq->q.read_ptr].skb = NULL;
+			txq->txb[index].skb = NULL;
 		}
 	}
 }
@@ -232,108 +233,11 @@ void iwl_tx_queue_unmap(struct iwl_priv *priv, int txq_id)
 		return;
 
 	 while (q->write_ptr != q->read_ptr) {
-		iwlagn_txq_free_tfd(priv, txq);
+		iwlagn_txq_free_tfd(priv, txq, get_cmd_index(q, q->read_ptr));
 		q->read_ptr = iwl_queue_inc_wrap(q->read_ptr, q->n_bd);
 	}
 }
 
-/**
- * iwl_tx_queue_free - Deallocate DMA queue.
- * @txq: Transmit queue to deallocate.
- *
- * Empty queue by removing and destroying all BD's.
- * Free all buffers.
- * 0-fill, but do not free "txq" descriptor structure.
- */
-void iwl_tx_queue_free(struct iwl_priv *priv, int txq_id)
-{
-	struct iwl_tx_queue *txq = &priv->txq[txq_id];
-	struct device *dev = priv->bus.dev;
-	int i;
-
-	iwl_tx_queue_unmap(priv, txq_id);
-
-	/* De-alloc array of command/tx buffers */
-	for (i = 0; i < TFD_TX_CMD_SLOTS; i++)
-		kfree(txq->cmd[i]);
-
-	/* De-alloc circular buffer of TFDs */
-	if (txq->q.n_bd)
-		dma_free_coherent(dev, priv->hw_params.tfd_size *
-				  txq->q.n_bd, txq->tfds, txq->q.dma_addr);
-
-	/* De-alloc array of per-TFD driver data */
-	kfree(txq->txb);
-	txq->txb = NULL;
-
-	/* deallocate arrays */
-	kfree(txq->cmd);
-	kfree(txq->meta);
-	txq->cmd = NULL;
-	txq->meta = NULL;
-
-	/* 0-fill queue descriptor structure */
-	memset(txq, 0, sizeof(*txq));
-}
-
-/**
- * iwl_cmd_queue_unmap - Unmap any remaining DMA mappings from command queue
- */
-void iwl_cmd_queue_unmap(struct iwl_priv *priv)
-{
-	struct iwl_tx_queue *txq = &priv->txq[priv->cmd_queue];
-	struct iwl_queue *q = &txq->q;
-	int i;
-
-	if (q->n_bd == 0)
-		return;
-
-	while (q->read_ptr != q->write_ptr) {
-		i = get_cmd_index(q, q->read_ptr);
-
-		iwlagn_unmap_tfd(priv, &txq->meta[i], &txq->tfds[i],
-				 DMA_BIDIRECTIONAL);
-		txq->meta[i].flags = 0;
-
-		q->read_ptr = iwl_queue_inc_wrap(q->read_ptr, q->n_bd);
-	}
-}
-
-/**
- * iwl_cmd_queue_free - Deallocate DMA queue.
- * @txq: Transmit queue to deallocate.
- *
- * Empty queue by removing and destroying all BD's.
- * Free all buffers.
- * 0-fill, but do not free "txq" descriptor structure.
- */
-void iwl_cmd_queue_free(struct iwl_priv *priv)
-{
-	struct iwl_tx_queue *txq = &priv->txq[priv->cmd_queue];
-	struct device *dev = priv->bus.dev;
-	int i;
-
-	iwl_cmd_queue_unmap(priv);
-
-	/* De-alloc array of command/tx buffers */
-	for (i = 0; i < TFD_CMD_SLOTS; i++)
-		kfree(txq->cmd[i]);
-
-	/* De-alloc circular buffer of TFDs */
-	if (txq->q.n_bd)
-		dma_free_coherent(dev, priv->hw_params.tfd_size * txq->q.n_bd,
-				  txq->tfds, txq->q.dma_addr);
-
-	/* deallocate arrays */
-	kfree(txq->cmd);
-	kfree(txq->meta);
-	txq->cmd = NULL;
-	txq->meta = NULL;
-
-	/* 0-fill queue descriptor structure */
-	memset(txq, 0, sizeof(*txq));
-}
-
 /*************** DMA-QUEUE-GENERAL-FUNCTIONS  *****
  * DMA services
  *