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>

4 files changed, 33 insertions, 22 deletions

diff --git a/drivers/net/wireless/iwlwifi/iwl-trans-pcie-int.h b/drivers/net/wireless/iwlwifi/iwl-trans-pcie-int.h
index 5b26b71ae3d..b1029468ccb 100644
--- a/drivers/net/wireless/iwlwifi/iwl-trans-pcie-int.h
+++ b/drivers/net/wireless/iwlwifi/iwl-trans-pcie-int.h
@@ -169,6 +169,7 @@ struct iwl_queue {
  * @meta: array of meta data for each command/tx buffer
  * @dma_addr_cmd: physical address of cmd/tx buffer array
  * @txb: array of per-TFD driver data
+ * lock: queue lock
  * @time_stamp: time (in jiffies) of last read_ptr change
  * @need_update: indicates need to update read/write index
  * @sched_retry: indicates queue is high-throughput aggregation (HT AGG) enabled
@@ -187,6 +188,7 @@ struct iwl_tx_queue {
         struct iwl_device_cmd **cmd;
         struct iwl_cmd_meta *meta;
         struct sk_buff **skbs;
+        spinlock_t lock;
         unsigned long time_stamp;
         u8 need_update;
         u8 sched_retry;
diff --git a/drivers/net/wireless/iwlwifi/iwl-trans-pcie-tx.c b/drivers/net/wireless/iwlwifi/iwl-trans-pcie-tx.c
index 82e34484fa5..1cb1dd29b3f 100644
--- a/drivers/net/wireless/iwlwifi/iwl-trans-pcie-tx.c
+++ b/drivers/net/wireless/iwlwifi/iwl-trans-pcie-tx.c
@@ -217,6 +217,8 @@ void iwlagn_txq_free_tfd(struct iwl_trans *trans, struct iwl_tx_queue *txq,
 {
         struct iwl_tfd *tfd_tmp = txq->tfds;
 
+        lockdep_assert_held(&txq->lock);
+
         iwlagn_unmap_tfd(trans, &txq->meta[index], &tfd_tmp[index], dma_dir);
 
         /* free SKB */
@@ -621,7 +623,6 @@ static int iwl_enqueue_hcmd(struct iwl_trans *trans, struct iwl_host_cmd *cmd)
         struct iwl_device_cmd *out_cmd;
         struct iwl_cmd_meta *out_meta;
         dma_addr_t phys_addr;
-        unsigned long flags;
         u32 idx;
         u16 copy_size, cmd_size;
         bool is_ct_kill = false;
@@ -680,10 +681,10 @@ static int iwl_enqueue_hcmd(struct iwl_trans *trans, struct iwl_host_cmd *cmd)
                 return -EIO;
         }
 
-        spin_lock_irqsave(&trans->hcmd_lock, flags);
+        spin_lock_bh(&txq->lock);
 
         if (iwl_queue_space(q) < ((cmd->flags & CMD_ASYNC) ? 2 : 1)) {
-                spin_unlock_irqrestore(&trans->hcmd_lock, flags);
+                spin_unlock_bh(&txq->lock);
 
                 IWL_ERR(trans, "No space in command queue\n");
                 is_ct_kill = iwl_check_for_ct_kill(priv(trans));
@@ -790,7 +791,7 @@ static int iwl_enqueue_hcmd(struct iwl_trans *trans, struct iwl_host_cmd *cmd)
         iwl_txq_update_write_ptr(trans, txq);
 
  out:
-        spin_unlock_irqrestore(&trans->hcmd_lock, flags);
+        spin_unlock_bh(&txq->lock);
         return idx;
 }
 
@@ -809,6 +810,8 @@ static void iwl_hcmd_queue_reclaim(struct iwl_trans *trans, int txq_id,
         struct iwl_queue *q = &txq->q;
         int nfreed = 0;
 
+        lockdep_assert_held(&txq->lock);
+
         if ((idx >= q->n_bd) || (iwl_queue_used(q, idx) == 0)) {
                 IWL_ERR(trans, "%s: Read index for DMA queue txq id (%d), "
                           "index %d is out of range [0-%d] %d %d.\n", __func__,
@@ -850,7 +853,6 @@ void iwl_tx_cmd_complete(struct iwl_trans *trans, struct iwl_rx_mem_buffer *rxb,
         struct iwl_cmd_meta *meta;
         struct iwl_trans_pcie *trans_pcie = IWL_TRANS_GET_PCIE_TRANS(trans);
         struct iwl_tx_queue *txq = &trans_pcie->txq[trans->shrd->cmd_queue];
-        unsigned long flags;
 
         /* If a Tx command is being handled and it isn't in the actual
          * command queue then there a command routing bug has been introduced
@@ -864,6 +866,8 @@ void iwl_tx_cmd_complete(struct iwl_trans *trans, struct iwl_rx_mem_buffer *rxb,
                 return;
         }
 
+        spin_lock(&txq->lock);
+
         cmd_index = get_cmd_index(&txq->q, index);
         cmd = txq->cmd[cmd_index];
         meta = &txq->meta[cmd_index];
@@ -880,8 +884,6 @@ void iwl_tx_cmd_complete(struct iwl_trans *trans, struct iwl_rx_mem_buffer *rxb,
                 rxb->page = NULL;
         }
 
-        spin_lock_irqsave(&trans->hcmd_lock, flags);
-
         iwl_hcmd_queue_reclaim(trans, txq_id, index);
 
         if (!(meta->flags & CMD_ASYNC)) {
@@ -898,7 +900,7 @@ void iwl_tx_cmd_complete(struct iwl_trans *trans, struct iwl_rx_mem_buffer *rxb,
 
         meta->flags = 0;
 
-        spin_unlock_irqrestore(&trans->hcmd_lock, flags);
+        spin_unlock(&txq->lock);
 }
 
 #define HOST_COMPLETE_TIMEOUT (2 * HZ)
@@ -1041,6 +1043,8 @@ int iwl_tx_queue_reclaim(struct iwl_trans *trans, int txq_id, int index,
         if (WARN_ON(txq_id == trans->shrd->cmd_queue))
                 return 0;
 
+        lockdep_assert_held(&txq->lock);
+
         /*Since we free until index _not_ inclusive, the one before index is
          * the last we will free. This one must be used */
         last_to_free = iwl_queue_dec_wrap(index, q->n_bd);
diff --git a/drivers/net/wireless/iwlwifi/iwl-trans-pcie.c b/drivers/net/wireless/iwlwifi/iwl-trans-pcie.c
index 9f8b2390940..f47426a5ef4 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
diff --git a/drivers/net/wireless/iwlwifi/iwl-trans.h b/drivers/net/wireless/iwlwifi/iwl-trans.h
index 4e7e6c0eede..e2f21cfc2cd 100644
--- a/drivers/net/wireless/iwlwifi/iwl-trans.h
+++ b/drivers/net/wireless/iwlwifi/iwl-trans.h
@@ -309,7 +309,6 @@ enum iwl_trans_state {
  * @ops - pointer to iwl_trans_ops
  * @op_mode - pointer to the op_mode
  * @shrd - pointer to iwl_shared which holds shared data from the upper layer
- * @hcmd_lock: protects HCMD
  * @reg_lock - protect hw register access
  * @dev - pointer to struct device * that represents the device
  * @irq - the irq number for the device
@@ -326,7 +325,6 @@ struct iwl_trans {
         struct iwl_op_mode *op_mode;
         struct iwl_shared *shrd;
         enum iwl_trans_state state;
-        spinlock_t hcmd_lock;
         spinlock_t reg_lock;
 
         struct device *dev;