iwlegacy: fix dma mappings and skbs leak

Fix possible dma mappings and skbs introduced by commit
470058e0ad82fcfaaffd57307d8bf8c094e8e9d7 "iwlwifi: avoid Tx queue
memory allocation in interface down".

Signed-off-by: Stanislaw Gruszka <sgruszka@redhat.com>
Acked-by: Wey-Yi Guy <wey-yi.w.guy@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

3 files changed, 62 insertions, 27 deletions

diff --git a/drivers/net/wireless/iwlegacy/iwl-4965-tx.c b/drivers/net/wireless/iwlegacy/iwl-4965-tx.c
index 829db91896b0..5c40502f869a 100644
--- a/drivers/net/wireless/iwlegacy/iwl-4965-tx.c
+++ b/drivers/net/wireless/iwlegacy/iwl-4965-tx.c
@@ -698,7 +698,7 @@ void iwl4965_txq_ctx_reset(struct iwl_priv *priv)
  */
 void iwl4965_txq_ctx_stop(struct iwl_priv *priv)
 {
-        int ch;
+        int ch, txq_id;
         unsigned long flags;
 
         /* Turn off all Tx DMA fifos */
@@ -719,6 +719,16 @@ void iwl4965_txq_ctx_stop(struct iwl_priv *priv)
                                         FH_TSSR_TX_STATUS_REG));
         }
         spin_unlock_irqrestore(&priv->lock, flags);
+
+        if (!priv->txq)
+                return;
+
+        /* 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_legacy_cmd_queue_unmap(priv);
+                else
+                        iwl_legacy_tx_queue_unmap(priv, txq_id);
 }
 
 /*
diff --git a/drivers/net/wireless/iwlegacy/iwl-core.h b/drivers/net/wireless/iwlegacy/iwl-core.h
index c6d12d7e96b6..f03b463e4378 100644
--- a/drivers/net/wireless/iwlegacy/iwl-core.h
+++ b/drivers/net/wireless/iwlegacy/iwl-core.h
@@ -388,6 +388,7 @@ void iwl_legacy_rx_reply_error(struct iwl_priv *priv,
 /*****************************************************
 * RX
 ******************************************************/
+void iwl_legacy_cmd_queue_unmap(struct iwl_priv *priv);
 void iwl_legacy_cmd_queue_free(struct iwl_priv *priv);
 int iwl_legacy_rx_queue_alloc(struct iwl_priv *priv);
 void iwl_legacy_rx_queue_update_write_ptr(struct iwl_priv *priv,
@@ -415,6 +416,7 @@ int iwl_legacy_tx_queue_init(struct iwl_priv *priv, struct iwl_tx_queue *txq,
 void iwl_legacy_tx_queue_reset(struct iwl_priv *priv,
                         struct iwl_tx_queue *txq,
                         int slots_num, u32 txq_id);
+void iwl_legacy_tx_queue_unmap(struct iwl_priv *priv, int txq_id);
 void iwl_legacy_tx_queue_free(struct iwl_priv *priv, int txq_id);
 void iwl_legacy_setup_watchdog(struct iwl_priv *priv);
 /*****************************************************
diff --git a/drivers/net/wireless/iwlegacy/iwl-tx.c b/drivers/net/wireless/iwlegacy/iwl-tx.c
index 7db8340d1c07..a227773cb384 100644
--- a/drivers/net/wireless/iwlegacy/iwl-tx.c
+++ b/drivers/net/wireless/iwlegacy/iwl-tx.c
@@ -82,6 +82,24 @@ iwl_legacy_txq_update_write_ptr(struct iwl_priv *priv, struct iwl_tx_queue *txq)
 EXPORT_SYMBOL(iwl_legacy_txq_update_write_ptr);
 
 /**
+ * iwl_legacy_tx_queue_unmap -  Unmap any remaining DMA mappings and free skb's
+ */
+void iwl_legacy_tx_queue_unmap(struct iwl_priv *priv, int txq_id)
+{
+        struct iwl_tx_queue *txq = &priv->txq[txq_id];
+        struct iwl_queue *q = &txq->q;
+
+        if (q->n_bd == 0)
+                return;
+
+        while (q->write_ptr != q->read_ptr) {
+                priv->cfg->ops->lib->txq_free_tfd(priv, txq);
+                q->read_ptr = iwl_legacy_queue_inc_wrap(q->read_ptr, q->n_bd);
+        }
+}
+EXPORT_SYMBOL(iwl_legacy_tx_queue_unmap);
+
+/**
  * iwl_legacy_tx_queue_free - Deallocate DMA queue.
  * @txq: Transmit queue to deallocate.
  *
@@ -92,17 +110,10 @@ EXPORT_SYMBOL(iwl_legacy_txq_update_write_ptr);
 void iwl_legacy_tx_queue_free(struct iwl_priv *priv, int txq_id)
 {
         struct iwl_tx_queue *txq = &priv->txq[txq_id];
-        struct iwl_queue *q = &txq->q;
         struct device *dev = &priv->pci_dev->dev;
         int i;
 
-        if (q->n_bd == 0)
-                return;
-
-        /* first, empty all BD's */
-        for (; q->write_ptr != q->read_ptr;
-             q->read_ptr = iwl_legacy_queue_inc_wrap(q->read_ptr, q->n_bd))
-                priv->cfg->ops->lib->txq_free_tfd(priv, txq);
+        iwl_legacy_tx_queue_unmap(priv, txq_id);
 
         /* De-alloc array of command/tx buffers */
         for (i = 0; i < TFD_TX_CMD_SLOTS; i++)
@@ -129,39 +140,33 @@ void iwl_legacy_tx_queue_free(struct iwl_priv *priv, int txq_id)
 EXPORT_SYMBOL(iwl_legacy_tx_queue_free);
 
 /**
- * iwl_legacy_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.
+ * iwl_cmd_queue_unmap - Unmap any remaining DMA mappings from command queue
  */
-void iwl_legacy_cmd_queue_free(struct iwl_priv *priv)
+void iwl_legacy_cmd_queue_unmap(struct iwl_priv *priv)
 {
         struct iwl_tx_queue *txq = &priv->txq[priv->cmd_queue];
         struct iwl_queue *q = &txq->q;
-        struct device *dev = &priv->pci_dev->dev;
-        int i;
         bool huge = false;
+        int i;
 
         if (q->n_bd == 0)
                 return;
 
-        for (; q->read_ptr != q->write_ptr;
-             q->read_ptr = iwl_legacy_queue_inc_wrap(q->read_ptr, q->n_bd)) {
+        while (q->read_ptr != q->write_ptr) {
                 /* we have no way to tell if it is a huge cmd ATM */
                 i = iwl_legacy_get_cmd_index(q, q->read_ptr, 0);
 
-                if (txq->meta[i].flags & CMD_SIZE_HUGE) {
+                if (txq->meta[i].flags & CMD_SIZE_HUGE)
                         huge = true;
-                        continue;
-                }
+                else
+                        pci_unmap_single(priv->pci_dev,
+                                         dma_unmap_addr(&txq->meta[i], mapping),
+                                         dma_unmap_len(&txq->meta[i], len),
+                                         PCI_DMA_BIDIRECTIONAL);
 
-                pci_unmap_single(priv->pci_dev,
-                                 dma_unmap_addr(&txq->meta[i], mapping),
-                                 dma_unmap_len(&txq->meta[i], len),
-                                 PCI_DMA_BIDIRECTIONAL);
+                q->read_ptr = iwl_legacy_queue_inc_wrap(q->read_ptr, q->n_bd);
         }
+
         if (huge) {
                 i = q->n_window;
                 pci_unmap_single(priv->pci_dev,
@@ -169,6 +174,24 @@ void iwl_legacy_cmd_queue_free(struct iwl_priv *priv)
                                  dma_unmap_len(&txq->meta[i], len),
                                  PCI_DMA_BIDIRECTIONAL);
         }
+}
+EXPORT_SYMBOL(iwl_legacy_cmd_queue_unmap);
+
+/**
+ * iwl_legacy_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_legacy_cmd_queue_free(struct iwl_priv *priv)
+{
+        struct iwl_tx_queue *txq = &priv->txq[priv->cmd_queue];
+        struct device *dev = &priv->pci_dev->dev;
+        int i;
+
+        iwl_legacy_cmd_queue_unmap(priv);
 
         /* De-alloc array of command/tx buffers */
         for (i = 0; i <= TFD_CMD_SLOTS; i++)