[PATCH 4.14 059/118] iwlwifi: pcie: fix DMA memory mapping / unmapping

[Greg Kroah-Hartman]

4.14-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Emmanuel Grumbach <emmanuel.grumbach@xxxxxxxxx>

commit 943309d4aad6732b905f3f500e6e17e33c211494 upstream.

22000 devices (previously referenced as A000) can support
short transmit queues. This means that we have less DMA
descriptors (TFD) for those shorter queues.
Previous devices must still have 256 TFDs for each queue
even if those 256 TFDs point to fewer buffers.

When I introduced support for the short queues for 22000
I broke older devices by assuming that they can also have
less TFDs in their queues. This led to several problems:

1) the payload of the commands weren't unmapped properly
   which caused the SWIOTLB to complain at some point.
2) the hardware could get confused and we get hardware
   crashes.

The corresponding bugzilla entries are:

https://bugzilla.kernel.org/show_bug.cgi?id=198201
https://bugzilla.kernel.org/show_bug.cgi?id=198265

Fixes: 4ecab5616023 ("iwlwifi: pcie: support short Tx queues for A000 device family")
Reviewed-by: Sharon, Sara <sara.sharon@xxxxxxxxx>
Signed-off-by: Emmanuel Grumbach <emmanuel.grumbach@xxxxxxxxx>
Signed-off-by: Kalle Valo <kvalo@xxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
 drivers/net/wireless/intel/iwlwifi/pcie/internal.h |   10 +++++++---
 drivers/net/wireless/intel/iwlwifi/pcie/tx-gen2.c  |   11 +++--------
 drivers/net/wireless/intel/iwlwifi/pcie/tx.c       |    8 ++++----
 3 files changed, 14 insertions(+), 15 deletions(-)

--- a/drivers/net/wireless/intel/iwlwifi/pcie/internal.h
+++ b/drivers/net/wireless/intel/iwlwifi/pcie/internal.h
@@ -666,11 +666,15 @@ static inline u8 iwl_pcie_get_cmd_index(
 	return index & (q->n_window - 1);
 }
 
-static inline void *iwl_pcie_get_tfd(struct iwl_trans_pcie *trans_pcie,
+static inline void *iwl_pcie_get_tfd(struct iwl_trans *trans,
 				     struct iwl_txq *txq, int idx)
 {
-	return txq->tfds + trans_pcie->tfd_size * iwl_pcie_get_cmd_index(txq,
-									 idx);
+	struct iwl_trans_pcie *trans_pcie = IWL_TRANS_GET_PCIE_TRANS(trans);
+
+	if (trans->cfg->use_tfh)
+		idx = iwl_pcie_get_cmd_index(txq, idx);
+
+	return txq->tfds + trans_pcie->tfd_size * idx;
 }
 
 static inline void iwl_enable_rfkill_int(struct iwl_trans *trans)
--- a/drivers/net/wireless/intel/iwlwifi/pcie/tx-gen2.c
+++ b/drivers/net/wireless/intel/iwlwifi/pcie/tx-gen2.c
@@ -171,8 +171,6 @@ static void iwl_pcie_gen2_tfd_unmap(stru
 
 static void iwl_pcie_gen2_free_tfd(struct iwl_trans *trans, struct iwl_txq *txq)
 {
-	struct iwl_trans_pcie *trans_pcie = IWL_TRANS_GET_PCIE_TRANS(trans);
-
 	/* rd_ptr is bounded by TFD_QUEUE_SIZE_MAX and
 	 * idx is bounded by n_window
 	 */
@@ -181,7 +179,7 @@ static void iwl_pcie_gen2_free_tfd(struc
 	lockdep_assert_held(&txq->lock);
 
 	iwl_pcie_gen2_tfd_unmap(trans, &txq->entries[idx].meta,
-				iwl_pcie_get_tfd(trans_pcie, txq, idx));
+				iwl_pcie_get_tfd(trans, txq, idx));
 
 	/* free SKB */
 	if (txq->entries) {
@@ -367,11 +365,9 @@ struct iwl_tfh_tfd *iwl_pcie_gen2_build_
 					    struct sk_buff *skb,
 					    struct iwl_cmd_meta *out_meta)
 {
-	struct iwl_trans_pcie *trans_pcie = IWL_TRANS_GET_PCIE_TRANS(trans);
 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
 	int idx = iwl_pcie_get_cmd_index(txq, txq->write_ptr);
-	struct iwl_tfh_tfd *tfd =
-		iwl_pcie_get_tfd(trans_pcie, txq, idx);
+	struct iwl_tfh_tfd *tfd = iwl_pcie_get_tfd(trans, txq, idx);
 	dma_addr_t tb_phys;
 	bool amsdu;
 	int i, len, tb1_len, tb2_len, hdr_len;
@@ -568,8 +564,7 @@ static int iwl_pcie_gen2_enqueue_hcmd(st
 	u8 group_id = iwl_cmd_groupid(cmd->id);
 	const u8 *cmddata[IWL_MAX_CMD_TBS_PER_TFD];
 	u16 cmdlen[IWL_MAX_CMD_TBS_PER_TFD];
-	struct iwl_tfh_tfd *tfd =
-		iwl_pcie_get_tfd(trans_pcie, txq, txq->write_ptr);
+	struct iwl_tfh_tfd *tfd = iwl_pcie_get_tfd(trans, txq, txq->write_ptr);
 
 	memset(tfd, 0, sizeof(*tfd));
 
--- a/drivers/net/wireless/intel/iwlwifi/pcie/tx.c
+++ b/drivers/net/wireless/intel/iwlwifi/pcie/tx.c
@@ -373,7 +373,7 @@ static void iwl_pcie_tfd_unmap(struct iw
 {
 	struct iwl_trans_pcie *trans_pcie = IWL_TRANS_GET_PCIE_TRANS(trans);
 	int i, num_tbs;
-	void *tfd = iwl_pcie_get_tfd(trans_pcie, txq, index);
+	void *tfd = iwl_pcie_get_tfd(trans, txq, index);
 
 	/* Sanity check on number of chunks */
 	num_tbs = iwl_pcie_tfd_get_num_tbs(trans, tfd);
@@ -1999,7 +1999,7 @@ static int iwl_fill_data_tbs(struct iwl_
 	}
 
 	trace_iwlwifi_dev_tx(trans->dev, skb,
-			     iwl_pcie_get_tfd(trans_pcie, txq, txq->write_ptr),
+			     iwl_pcie_get_tfd(trans, txq, txq->write_ptr),
 			     trans_pcie->tfd_size,
 			     &dev_cmd->hdr, IWL_FIRST_TB_SIZE + tb1_len,
 			     hdr_len);
@@ -2073,7 +2073,7 @@ static int iwl_fill_data_tbs_amsdu(struc
 		IEEE80211_CCMP_HDR_LEN : 0;
 
 	trace_iwlwifi_dev_tx(trans->dev, skb,
-			     iwl_pcie_get_tfd(trans_pcie, txq, txq->write_ptr),
+			     iwl_pcie_get_tfd(trans, txq, txq->write_ptr),
 			     trans_pcie->tfd_size,
 			     &dev_cmd->hdr, IWL_FIRST_TB_SIZE + tb1_len, 0);
 
@@ -2406,7 +2406,7 @@ int iwl_trans_pcie_tx(struct iwl_trans *
 	memcpy(&txq->first_tb_bufs[txq->write_ptr], &dev_cmd->hdr,
 	       IWL_FIRST_TB_SIZE);
 
-	tfd = iwl_pcie_get_tfd(trans_pcie, txq, txq->write_ptr);
+	tfd = iwl_pcie_get_tfd(trans, txq, txq->write_ptr);
 	/* Set up entry for this TFD in Tx byte-count array */
 	iwl_pcie_txq_update_byte_cnt_tbl(trans, txq, le16_to_cpu(tx_cmd->len),
 					 iwl_pcie_tfd_get_num_tbs(trans, tfd));