iwlwifi: queue: avoid memory leak in reset flow

In case the device is stopped any usage of hw queues needs to be
reallocated in fw due to fw reset after device stop, so all driver
internal queue should also be freed, and if we don't free the next usage
would leak the old memory and get in recover flows
"iwlwifi 0000:00:03.0: dma_pool_destroy iwlwifi:bc" warning.

Also warn about trying to reuse an internal allocated queue.

Signed-off-by: Mordechay Goodstein <mordechay.goodstein@intel.com>
Signed-off-by: Luca Coelho <luciano.coelho@intel.com>
Link: https://lore.kernel.org/r/iwlwifi.20210411124417.c72d2f0355c4.Ia3baff633b9b9109f88ab379ef0303aa152c16bf@changeid
Signed-off-by: Luca Coelho <luciano.coelho@intel.com>

drivers/net/wireless/intel/iwlwifi/pcie/trans-gen2.c

@@ -1,7 +1,7 @@
 // SPDX-License-Identifier: GPL-2.0 OR BSD-3-Clause
 /*
  * Copyright (C) 2017 Intel Deutschland GmbH
- * Copyright (C) 2018-2020 Intel Corporation
+ * Copyright (C) 2018-2021 Intel Corporation
  */
 #include "iwl-trans.h"
 #include "iwl-prph.h"
@@ -143,7 +143,7 @@ void _iwl_trans_pcie_gen2_stop_device(struct iwl_trans *trans)
 	if (test_and_clear_bit(STATUS_DEVICE_ENABLED, &trans->status)) {
 		IWL_DEBUG_INFO(trans,
 			       "DEVICE_ENABLED bit was set and is now cleared\n");
-		iwl_txq_gen2_tx_stop(trans);
+		iwl_txq_gen2_tx_free(trans);
 		iwl_pcie_rx_stop(trans);
 	}
 

drivers/net/wireless/intel/iwlwifi/queue/tx.c

@@ -13,30 +13,6 @@
 #include "iwl-scd.h"
 #include <linux/dmapool.h>
 
-/*
- * iwl_txq_gen2_tx_stop - Stop all Tx DMA channels
- */
-void iwl_txq_gen2_tx_stop(struct iwl_trans *trans)
-{
-	int txq_id;
-
-	/*
-	 * This function can be called before the op_mode disabled the
-	 * queues. This happens when we have an rfkill interrupt.
-	 * Since we stop Tx altogether - mark the queues as stopped.
-	 */
-	memset(trans->txqs.queue_stopped, 0,
-	       sizeof(trans->txqs.queue_stopped));
-	memset(trans->txqs.queue_used, 0, sizeof(trans->txqs.queue_used));
-
-	/* Unmap DMA from host system and free skb's */
-	for (txq_id = 0; txq_id < ARRAY_SIZE(trans->txqs.txq); txq_id++) {
-		if (!trans->txqs.txq[txq_id])
-			continue;
-		iwl_txq_gen2_unmap(trans, txq_id);
-	}
-}
-
 /*
  * iwl_txq_update_byte_tbl - Set up entry in Tx byte-count array
  */
@@ -1184,6 +1160,12 @@ static int iwl_txq_alloc_response(struct iwl_trans *trans, struct iwl_txq *txq,
 		goto error_free_resp;
 	}
 
+	if (WARN_ONCE(trans->txqs.txq[qid],
+		      "queue %d already allocated\n", qid)) {
+		ret = -EIO;
+		goto error_free_resp;
+	}
+
 	txq->id = qid;
 	trans->txqs.txq[qid] = txq;
 	wr_ptr &= (trans->trans_cfg->base_params->max_tfd_queue_size - 1);

drivers/net/wireless/intel/iwlwifi/queue/tx.h

@@ -1,6 +1,6 @@
 /* SPDX-License-Identifier: GPL-2.0 OR BSD-3-Clause */
 /*
- * Copyright (C) 2020 Intel Corporation
+ * Copyright (C) 2020-2021 Intel Corporation
  */
 #ifndef __iwl_trans_queue_tx_h__
 #define __iwl_trans_queue_tx_h__
@@ -123,7 +123,6 @@ int iwl_txq_gen2_tx(struct iwl_trans *trans, struct sk_buff *skb,
 void iwl_txq_dyn_free(struct iwl_trans *trans, int queue);
 void iwl_txq_gen2_free_tfd(struct iwl_trans *trans, struct iwl_txq *txq);
 void iwl_txq_inc_wr_ptr(struct iwl_trans *trans, struct iwl_txq *txq);
-void iwl_txq_gen2_tx_stop(struct iwl_trans *trans);
 void iwl_txq_gen2_tx_free(struct iwl_trans *trans);
 int iwl_txq_init(struct iwl_trans *trans, struct iwl_txq *txq, int slots_num,
 		 bool cmd_queue);