iwlwifi: pcie: add basic reference accounting

Implement the ref/unref trans ops and track both tx and
host command queues (and hold references while they
are not empty).

Signed-off-by: Eliad Peller <eliadx.peller@intel.com>
Reviewed-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com>
diff --git a/drivers/net/wireless/iwlwifi/pcie/trans.c b/drivers/net/wireless/iwlwifi/pcie/trans.c
index 4b42de3..fbdbec8 100644
--- a/drivers/net/wireless/iwlwifi/pcie/trans.c
+++ b/drivers/net/wireless/iwlwifi/pcie/trans.c
@@ -931,6 +931,7 @@
 static int iwl_trans_pcie_start_fw(struct iwl_trans *trans,
 				   const struct fw_img *fw, bool run_in_rfkill)
 {
+	struct iwl_trans_pcie *trans_pcie = IWL_TRANS_GET_PCIE_TRANS(trans);
 	int ret;
 	bool hw_rfkill;
 
@@ -960,6 +961,9 @@
 		return ret;
 	}
 
+	/* init ref_count to 1 (should be cleared when ucode is loaded) */
+	trans_pcie->ref_count = 1;
+
 	/* make sure rfkill handshake bits are cleared */
 	iwl_write32(trans, CSR_UCODE_DRV_GP1_CLR, CSR_UCODE_SW_BIT_RFKILL);
 	iwl_write32(trans, CSR_UCODE_DRV_GP1_CLR,
@@ -1550,6 +1554,38 @@
 	spin_unlock_irqrestore(&trans_pcie->reg_lock, flags);
 }
 
+void iwl_trans_pcie_ref(struct iwl_trans *trans)
+{
+	struct iwl_trans_pcie *trans_pcie = IWL_TRANS_GET_PCIE_TRANS(trans);
+	unsigned long flags;
+
+	if (iwlwifi_mod_params.d0i3_disable)
+		return;
+
+	spin_lock_irqsave(&trans_pcie->ref_lock, flags);
+	IWL_DEBUG_RPM(trans, "ref_counter: %d\n", trans_pcie->ref_count);
+	trans_pcie->ref_count++;
+	spin_unlock_irqrestore(&trans_pcie->ref_lock, flags);
+}
+
+void iwl_trans_pcie_unref(struct iwl_trans *trans)
+{
+	struct iwl_trans_pcie *trans_pcie = IWL_TRANS_GET_PCIE_TRANS(trans);
+	unsigned long flags;
+
+	if (iwlwifi_mod_params.d0i3_disable)
+		return;
+
+	spin_lock_irqsave(&trans_pcie->ref_lock, flags);
+	IWL_DEBUG_RPM(trans, "ref_counter: %d\n", trans_pcie->ref_count);
+	if (WARN_ON_ONCE(trans_pcie->ref_count == 0)) {
+		spin_unlock_irqrestore(&trans_pcie->ref_lock, flags);
+		return;
+	}
+	trans_pcie->ref_count--;
+	spin_unlock_irqrestore(&trans_pcie->ref_lock, flags);
+}
+
 static const char *get_csr_string(int cmd)
 {
 #define IWL_CMD(x) case x: return #x
@@ -2274,6 +2310,9 @@
 	.release_nic_access = iwl_trans_pcie_release_nic_access,
 	.set_bits_mask = iwl_trans_pcie_set_bits_mask,
 
+	.ref = iwl_trans_pcie_ref,
+	.unref = iwl_trans_pcie_unref,
+
 	.dump_data = iwl_trans_pcie_dump_data,
 };