iwlwifi: pcie: dynamic Tx command queue size

Devices in the A000 family can use a different size for the command queue.
To allow this, make the command queue size configurable and set the size
for A000 devices to 32.
Signed-off-by: NShahar S Matityahu <shahar.s.matityahu@intel.com>
Signed-off-by: NLuca Coelho <luciano.coelho@intel.com>

drivers/net/wireless/intel/iwlwifi/cfg/a000.c

@@ -134,7 +134,8 @@ static const struct iwl_ht_params iwl_a000_ht_params = {
 	.rf_id = true,							\
 	.gen2 = true,							\
 	.ext_nvm = true,						\
-	.dbgc_supported = true
+	.dbgc_supported = true,						\
+	.tx_cmd_queue_size = 32
 
 const struct iwl_cfg iwla000_2ac_cfg_hr = {
 		.name = "Intel(R) Dual Band Wireless AC a000",

drivers/net/wireless/intel/iwlwifi/iwl-config.h

@@ -321,6 +321,8 @@ struct iwl_pwr_tx_backoff {
  * @gen2: a000 and on transport operation
  * @cdb: CDB support
  * @ext_nvm: extended NVM format
+ * @tx_cmd_queue_size: size of the cmd queue. If zero, use the same value as
+ *	the regular queues
  *
  * We enable the driver to be backward compatible wrt. hardware features.
  * API differences in uCode shouldn't be handled here but through TLVs
@@ -371,6 +373,7 @@ struct iwl_cfg {
 	    cdb:1,
 	    ext_nvm:1,
 	    dbgc_supported:1;
+	u16 tx_cmd_queue_size;
 	u8 valid_tx_ant;
 	u8 valid_rx_ant;
 	u8 non_shared_ant;

drivers/net/wireless/intel/iwlwifi/pcie/ctxt-info.c

@@ -244,7 +244,7 @@ int iwl_pcie_ctxt_info_init(struct iwl_trans *trans,
 	ctxt_info->hcmd_cfg.cmd_queue_addr =
 		cpu_to_le64(trans_pcie->txq[trans_pcie->cmd_queue]->dma_addr);
 	ctxt_info->hcmd_cfg.cmd_queue_size =
-		TFD_QUEUE_CB_SIZE(TFD_CMD_SLOTS);
+		TFD_QUEUE_CB_SIZE(trans_pcie->tx_cmd_queue_size);
 
 	/* allocate ucode sections in dram and set addresses */
 	ret = iwl_pcie_ctxt_info_init_fw_sec(trans, fw, ctxt_info);

drivers/net/wireless/intel/iwlwifi/pcie/internal.h

@@ -383,6 +383,7 @@ struct iwl_self_init_dram {
  * @hw_init_mask: initial unmasked hw causes
  * @fh_mask: current unmasked fh causes
  * @hw_mask: current unmasked hw causes
+ * @tx_cmd_queue_size: the size of the tx command queue
  */
 struct iwl_trans_pcie {
 	struct iwl_rxq *rxq;
@@ -463,6 +464,7 @@ struct iwl_trans_pcie {
 	u32 fh_mask;
 	u32 hw_mask;
 	cpumask_t affinity_mask[IWL_MAX_RX_HW_QUEUES];
+	u16 tx_cmd_queue_size;
 };
 
 static inline struct iwl_trans_pcie *
@@ -534,6 +536,7 @@ void iwl_pcie_hcmd_complete(struct iwl_trans *trans,
 void iwl_trans_pcie_reclaim(struct iwl_trans *trans, int txq_id, int ssn,
 			    struct sk_buff_head *skbs);
 void iwl_trans_pcie_tx_reset(struct iwl_trans *trans);
+void iwl_pcie_set_tx_cmd_queue_size(struct iwl_trans *trans);
 
 static inline u16 iwl_pcie_tfd_tb_get_len(struct iwl_trans *trans, void *_tfd,
 					  u8 idx)

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

@@ -1160,6 +1160,8 @@ int iwl_pcie_gen2_tx_init(struct iwl_trans *trans)
 	struct iwl_txq *cmd_queue;
 	int txq_id = trans_pcie->cmd_queue, ret;
 
+	iwl_pcie_set_tx_cmd_queue_size(trans);
+
 	/* alloc and init the command queue */
 	if (!trans_pcie->txq[txq_id]) {
 		cmd_queue = kzalloc(sizeof(*cmd_queue), GFP_KERNEL);
@@ -1168,7 +1170,8 @@ int iwl_pcie_gen2_tx_init(struct iwl_trans *trans)
 			return -ENOMEM;
 		}
 		trans_pcie->txq[txq_id] = cmd_queue;
-		ret = iwl_pcie_txq_alloc(trans, cmd_queue, TFD_CMD_SLOTS, true);
+		ret = iwl_pcie_txq_alloc(trans, cmd_queue,
+					 trans_pcie->tx_cmd_queue_size, true);
 		if (ret) {
 			IWL_ERR(trans, "Tx %d queue init failed\n", txq_id);
 			goto error;
@@ -1177,7 +1180,8 @@ int iwl_pcie_gen2_tx_init(struct iwl_trans *trans)
 		cmd_queue = trans_pcie->txq[txq_id];
 	}
 
-	ret = iwl_pcie_txq_init(trans, cmd_queue, TFD_CMD_SLOTS, true);
+	ret = iwl_pcie_txq_init(trans, cmd_queue,
+				trans_pcie->tx_cmd_queue_size, true);
 	if (ret) {
 		IWL_ERR(trans, "Tx %d queue alloc failed\n", txq_id);
 		goto error;

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

@@ -951,7 +951,8 @@ static int iwl_pcie_tx_alloc(struct iwl_trans *trans)
 	     txq_id++) {
 		bool cmd_queue = (txq_id == trans_pcie->cmd_queue);
 
-		slots_num = cmd_queue ? TFD_CMD_SLOTS : TFD_TX_CMD_SLOTS;
+		slots_num = cmd_queue ? trans_pcie->tx_cmd_queue_size :
+			TFD_TX_CMD_SLOTS;
 		trans_pcie->txq[txq_id] = &trans_pcie->txq_memory[txq_id];
 		ret = iwl_pcie_txq_alloc(trans, trans_pcie->txq[txq_id],
 					 slots_num, cmd_queue);
@@ -970,6 +971,21 @@ static int iwl_pcie_tx_alloc(struct iwl_trans *trans)
 	return ret;
 }
 
+void iwl_pcie_set_tx_cmd_queue_size(struct iwl_trans *trans)
+{
+	struct iwl_trans_pcie *trans_pcie = IWL_TRANS_GET_PCIE_TRANS(trans);
+	int queue_size = TFD_CMD_SLOTS;
+
+	if (trans->cfg->tx_cmd_queue_size)
+		queue_size = trans->cfg->tx_cmd_queue_size;
+
+	if (WARN_ON(!(is_power_of_2(queue_size) &&
+		      TFD_QUEUE_CB_SIZE(queue_size) > 0)))
+		trans_pcie->tx_cmd_queue_size = TFD_CMD_SLOTS;
+	else
+		trans_pcie->tx_cmd_queue_size = queue_size;
+}
+
 int iwl_pcie_tx_init(struct iwl_trans *trans)
 {
 	struct iwl_trans_pcie *trans_pcie = IWL_TRANS_GET_PCIE_TRANS(trans);
@@ -977,6 +993,8 @@ int iwl_pcie_tx_init(struct iwl_trans *trans)
 	int txq_id, slots_num;
 	bool alloc = false;
 
+	iwl_pcie_set_tx_cmd_queue_size(trans);
+
 	if (!trans_pcie->txq_memory) {
 		ret = iwl_pcie_tx_alloc(trans);
 		if (ret)
@@ -1000,7 +1018,8 @@ int iwl_pcie_tx_init(struct iwl_trans *trans)
 	     txq_id++) {
 		bool cmd_queue = (txq_id == trans_pcie->cmd_queue);
 
-		slots_num = cmd_queue ? TFD_CMD_SLOTS : TFD_TX_CMD_SLOTS;
+		slots_num = cmd_queue ? trans_pcie->tx_cmd_queue_size :
+			TFD_TX_CMD_SLOTS;
 		ret = iwl_pcie_txq_init(trans, trans_pcie->txq[txq_id],
 					slots_num, cmd_queue);
 		if (ret) {