iwlwifi: introduce per-queue locks

Instead of (ab)using the sta_lock, make the
transport layer lock its own TX queue data
structures with a lock per queue. This also
unifies with the cmd queue lock.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Wey-Yi Guy <wey-yi.w.guy@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

1 files changed, 19 insertions, 12 deletions

diff --git a/drivers/net/wireless/iwlwifi/iwl-trans-pcie.c b/drivers/net/wireless/iwlwifi/iwl-trans-pcie.c
index 9f8b23909404..f47426a5ef4d 100644
--- a/drivers/net/wireless/iwlwifi/iwl-trans-pcie.c
+++ b/drivers/net/wireless/iwlwifi/iwl-trans-pcie.c
@@ -390,6 +390,8 @@ static int iwl_trans_txq_init(struct iwl_trans *trans, struct iwl_tx_queue *txq,
 	if (ret)
 		return ret;
 
+	spin_lock_init(&txq->lock);
+
 	/*
 	 * Tell nic where to find circular buffer of Tx Frame Descriptors for
 	 * given Tx queue, and enable the DMA channel used for that queue.
@@ -409,8 +411,6 @@ static void iwl_tx_queue_unmap(struct iwl_trans *trans, int txq_id)
 	struct iwl_tx_queue *txq = &trans_pcie->txq[txq_id];
 	struct iwl_queue *q = &txq->q;
 	enum dma_data_direction dma_dir;
-	unsigned long flags;
-	spinlock_t *lock;
 
 	if (!q->n_bd)
 		return;
@@ -418,22 +418,19 @@ static void iwl_tx_queue_unmap(struct iwl_trans *trans, int txq_id)
 	/* In the command queue, all the TBs are mapped as BIDI
 	 * so unmap them as such.
 	 */
-	if (txq_id == trans->shrd->cmd_queue) {
+	if (txq_id == trans->shrd->cmd_queue)
 		dma_dir = DMA_BIDIRECTIONAL;
-		lock = &trans->hcmd_lock;
-	} else {
+	else
 		dma_dir = DMA_TO_DEVICE;
-		lock = &trans->shrd->sta_lock;
-	}
 
-	spin_lock_irqsave(lock, flags);
+	spin_lock_bh(&txq->lock);
 	while (q->write_ptr != q->read_ptr) {
 		/* The read_ptr needs to bound by q->n_window */
 		iwlagn_txq_free_tfd(trans, txq, get_cmd_index(q, q->read_ptr),
 				    dma_dir);
 		q->read_ptr = iwl_queue_inc_wrap(q->read_ptr, q->n_bd);
 	}
-	spin_unlock_irqrestore(lock, flags);
+	spin_unlock_bh(&txq->lock);
 }
 
 /**
@@ -1358,6 +1355,8 @@ static int iwl_trans_pcie_tx(struct iwl_trans *trans, struct sk_buff *skb,
 	txq = &trans_pcie->txq[txq_id];
 	q = &txq->q;
 
+	spin_lock(&txq->lock);
+
 	/* In AGG mode, the index in the ring must correspond to the WiFi
 	 * sequence number. This is a HW requirements to help the SCD to parse
 	 * the BA.
@@ -1404,7 +1403,7 @@ static int iwl_trans_pcie_tx(struct iwl_trans *trans, struct sk_buff *skb,
 				    &dev_cmd->hdr, firstlen,
 				    DMA_BIDIRECTIONAL);
 	if (unlikely(dma_mapping_error(trans->dev, txcmd_phys)))
-		return -1;
+		goto out_err;
 	dma_unmap_addr_set(out_meta, mapping, txcmd_phys);
 	dma_unmap_len_set(out_meta, len, firstlen);
 
@@ -1426,7 +1425,7 @@ static int iwl_trans_pcie_tx(struct iwl_trans *trans, struct sk_buff *skb,
 					 dma_unmap_addr(out_meta, mapping),
 					 dma_unmap_len(out_meta, len),
 					 DMA_BIDIRECTIONAL);
-			return -1;
+			goto out_err;
 		}
 	}
 
@@ -1481,7 +1480,11 @@ static int iwl_trans_pcie_tx(struct iwl_trans *trans, struct sk_buff *skb,
 			iwl_stop_queue(trans, txq, "Queue is full");
 		}
 	}
+	spin_unlock(&txq->lock);
 	return 0;
+ out_err:
+	spin_unlock(&txq->lock);
+	return -1;
 }
 
 static int iwl_trans_pcie_start_hw(struct iwl_trans *trans)
@@ -1560,6 +1563,8 @@ static int iwl_trans_pcie_reclaim(struct iwl_trans *trans, int sta_id, int tid,
 	int tfd_num = ssn & (txq->q.n_bd - 1);
 	int freed = 0;
 
+	spin_lock(&txq->lock);
+
 	txq->time_stamp = jiffies;
 
 	if (unlikely(txq_id >= IWLAGN_FIRST_AMPDU_QUEUE &&
@@ -1574,6 +1579,7 @@ static int iwl_trans_pcie_reclaim(struct iwl_trans *trans, int sta_id, int tid,
 		IWL_DEBUG_TX_QUEUES(trans, "Bad queue mapping txq_id %d, "
 			"agg_txq[sta_id[tid] %d", txq_id,
 			trans_pcie->agg_txq[sta_id][tid]);
+		spin_unlock(&txq->lock);
 		return 1;
 	}
 
@@ -1587,6 +1593,8 @@ static int iwl_trans_pcie_reclaim(struct iwl_trans *trans, int sta_id, int tid,
 		   status != TX_STATUS_FAIL_PASSIVE_NO_RX))
 			iwl_wake_queue(trans, txq, "Packets reclaimed");
 	}
+
+	spin_unlock(&txq->lock);
 	return 0;
 }
 
@@ -2267,7 +2275,6 @@ struct iwl_trans *iwl_trans_pcie_alloc(struct iwl_shared *shrd,
 	trans->ops = &trans_ops_pcie;
 	trans->shrd = shrd;
 	trans_pcie->trans = trans;
-	spin_lock_init(&trans->hcmd_lock);
 	spin_lock_init(&trans_pcie->irq_lock);
 
 	/* W/A - seems to solve weird behavior. We need to remove this if we