Commit 72bc934c authored by Johannes Berg's avatar Johannes Berg Committed by Luca Coelho
Browse files

iwlwifi: pcie: avoid unnecessarily taking spinlock 



Most devices don't set the apmg_wake_up_wa flag, so we don't do
anything for them. Avoid taking the spinlock for every command
unless the device needs this workaround.

Signed-off-by: default avatarJohannes Berg <johannes.berg@intel.com>
Signed-off-by: default avatarLuca Coelho <luciano.coelho@intel.com>
Link: https://lore.kernel.org/r/iwlwifi.20210330162204.1ab60af3f318.I51cc202f68a2a953223e70c3e8610343412961b6@changeid


Signed-off-by: default avatarLuca Coelho <luciano.coelho@intel.com>
parent 7686fd52

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

+24 −30
Original line number Diff line number Diff line
@@ -181,16 +181,20 @@ static void iwl_pcie_clear_cmd_in_flight(struct iwl_trans *trans) 
{

	struct iwl_trans_pcie *trans_pcie = IWL_TRANS_GET_PCIE_TRANS(trans);



	lockdep_assert_held(&trans_pcie->reg_lock);



	if (!trans->trans_cfg->base_params->apmg_wake_up_wa)

		return;

	if (WARN_ON(!trans_pcie->cmd_hold_nic_awake))



	spin_lock(&trans_pcie->reg_lock);



	if (WARN_ON(!trans_pcie->cmd_hold_nic_awake)) {

		spin_unlock(&trans_pcie->reg_lock);

		return;

	}



	trans_pcie->cmd_hold_nic_awake = false;

	__iwl_trans_pcie_clear_bit(trans, CSR_GP_CNTRL,

				   CSR_GP_CNTRL_REG_FLAG_MAC_ACCESS_REQ);

	spin_unlock(&trans_pcie->reg_lock);

}



/*
@@ -198,7 +202,6 @@ static void iwl_pcie_clear_cmd_in_flight(struct iwl_trans *trans) 
 */

static void iwl_pcie_txq_unmap(struct iwl_trans *trans, int txq_id)

{

	struct iwl_trans_pcie *trans_pcie = IWL_TRANS_GET_PCIE_TRANS(trans);

	struct iwl_txq *txq = trans->txqs.txq[txq_id];



	if (!txq) {
@@ -222,12 +225,9 @@ static void iwl_pcie_txq_unmap(struct iwl_trans *trans, int txq_id) 
		iwl_txq_free_tfd(trans, txq);

		txq->read_ptr = iwl_txq_inc_wrap(trans, txq->read_ptr);



		if (txq->read_ptr == txq->write_ptr) {

			spin_lock(&trans_pcie->reg_lock);

			if (txq_id == trans->txqs.cmd.q_id)

		if (txq->read_ptr == txq->write_ptr &&

		    txq_id == trans->txqs.cmd.q_id)

			iwl_pcie_clear_cmd_in_flight(trans);

			spin_unlock(&trans_pcie->reg_lock);

		}

	}



	while (!skb_queue_empty(&txq->overflow_q)) {
@@ -629,22 +629,23 @@ static int iwl_pcie_set_cmd_in_flight(struct iwl_trans *trans, 
				      const struct iwl_host_cmd *cmd)

{

	struct iwl_trans_pcie *trans_pcie = IWL_TRANS_GET_PCIE_TRANS(trans);

	int ret;



	lockdep_assert_held(&trans_pcie->reg_lock);

	int ret = 0;



	/* Make sure the NIC is still alive in the bus */

	if (test_bit(STATUS_TRANS_DEAD, &trans->status))

		return -ENODEV;



	if (!trans->trans_cfg->base_params->apmg_wake_up_wa)

		return 0;



	spin_lock(&trans_pcie->reg_lock);

	/*

	 * wake up the NIC to make sure that the firmware will see the host

	 * command - we will let the NIC sleep once all the host commands

	 * returned. This needs to be done only on NICs that have

	 * apmg_wake_up_wa set.

	 * apmg_wake_up_wa set (see above.)

	 */

	if (trans->trans_cfg->base_params->apmg_wake_up_wa &&

	    !trans_pcie->cmd_hold_nic_awake) {

	if (!trans_pcie->cmd_hold_nic_awake) {

		__iwl_trans_pcie_set_bit(trans, CSR_GP_CNTRL,

					 CSR_GP_CNTRL_REG_FLAG_MAC_ACCESS_REQ);
@@ -657,12 +658,14 @@ static int iwl_pcie_set_cmd_in_flight(struct iwl_trans *trans, 
			__iwl_trans_pcie_clear_bit(trans, CSR_GP_CNTRL,

					CSR_GP_CNTRL_REG_FLAG_MAC_ACCESS_REQ);

			IWL_ERR(trans, "Failed to wake NIC for hcmd\n");

			return -EIO;

		}

			ret = -EIO;

		} else {

			trans_pcie->cmd_hold_nic_awake = true;

		}

	}

	spin_unlock(&trans_pcie->reg_lock);



	return 0;

	return ret;

}



/*
@@ -674,7 +677,6 @@ static int iwl_pcie_set_cmd_in_flight(struct iwl_trans *trans, 
 */

static void iwl_pcie_cmdq_reclaim(struct iwl_trans *trans, int txq_id, int idx)

{

	struct iwl_trans_pcie *trans_pcie = IWL_TRANS_GET_PCIE_TRANS(trans);

	struct iwl_txq *txq = trans->txqs.txq[txq_id];

	int nfreed = 0;

	u16 r;
@@ -705,12 +707,8 @@ static void iwl_pcie_cmdq_reclaim(struct iwl_trans *trans, int txq_id, int idx) 
		}

	}



	if (txq->read_ptr == txq->write_ptr) {

		/* BHs are also disabled due to txq->lock */

		spin_lock(&trans_pcie->reg_lock);

	if (txq->read_ptr == txq->write_ptr)

		iwl_pcie_clear_cmd_in_flight(trans);

		spin_unlock(&trans_pcie->reg_lock);

	}



	iwl_txq_progress(txq);

}
@@ -914,7 +912,6 @@ void iwl_trans_pcie_txq_disable(struct iwl_trans *trans, int txq_id, 
int iwl_pcie_enqueue_hcmd(struct iwl_trans *trans,

			  struct iwl_host_cmd *cmd)

{

	struct iwl_trans_pcie *trans_pcie = IWL_TRANS_GET_PCIE_TRANS(trans);

	struct iwl_txq *txq = trans->txqs.txq[trans->txqs.cmd.q_id];

	struct iwl_device_cmd *out_cmd;

	struct iwl_cmd_meta *out_meta;
@@ -1161,19 +1158,16 @@ int iwl_pcie_enqueue_hcmd(struct iwl_trans *trans, 
	if (txq->read_ptr == txq->write_ptr && txq->wd_timeout)

		mod_timer(&txq->stuck_timer, jiffies + txq->wd_timeout);



	spin_lock(&trans_pcie->reg_lock);

	ret = iwl_pcie_set_cmd_in_flight(trans, cmd);

	if (ret < 0) {

		idx = ret;

		goto unlock_reg;

		goto out;

	}



	/* Increment and update queue's write index */

	txq->write_ptr = iwl_txq_inc_wrap(trans, txq->write_ptr);

	iwl_pcie_txq_inc_wr_ptr(trans, txq);



 unlock_reg:

	spin_unlock(&trans_pcie->reg_lock);

 out:

	spin_unlock_irqrestore(&txq->lock, flags);

 free_dup_buf: