wifi: iwlwifi: mei: implement PLDR flow

If the FW needs to do OTP re-read, the driver must notify CSME before
loading the FW so CSME will not try to access the NIC during the
re-read. Once the alive notification is received, CSME is notified
that NIC access is allowed again.

Signed-off-by: Avraham Stern <avraham.stern@intel.com>
Signed-off-by: Gregory Greenman <gregory.greenman@intel.com>
Link: https://lore.kernel.org/r/20221102165239.49eb8c6d455f.I7f0a5debb2d3d662a4151199bbec24613f324c13@changeid

1 files changed, 100 insertions, 0 deletions

diff --git a/drivers/net/wireless/intel/iwlwifi/mei/main.c b/drivers/net/wireless/intel/iwlwifi/mei/main.c
index c0142093c768..a467da8b2aed 100644
--- a/drivers/net/wireless/intel/iwlwifi/mei/main.c
+++ b/drivers/net/wireless/intel/iwlwifi/mei/main.c
@@ -150,6 +150,8 @@ struct iwl_mei_filters {
  * @device_down: true if the device is down. Used to remember to send
  *	CSME_OWNERSHIP_CONFIRMED when the driver is already down.
  * @csa_throttle_end_wk: used when &csa_throttled is true
+ * @pldr_wq: the wait queue for PLDR flow
+ * @pldr_active: PLDR flow is in progress
  * @data_q_lock: protects the access to the data queues which are
  *	accessed without the mutex.
  * @netdev_work: used to defer registering and unregistering of the netdev to
@@ -173,6 +175,8 @@ struct iwl_mei {
 	bool link_prot_state;
 	bool device_down;
 	struct delayed_work csa_throttle_end_wk;
+	wait_queue_head_t pldr_wq;
+	bool pldr_active;
 	spinlock_t data_q_lock;
 	struct work_struct netdev_work;
 
@@ -881,6 +885,15 @@ static void iwl_mei_handle_rx_host_own_req(struct mei_cl_device *cldev,
 		iwl_mei_cache.ops->rfkill(iwl_mei_cache.priv, false);
 }
 
+static void iwl_mei_handle_pldr_ack(struct mei_cl_device *cldev,
+				    const struct iwl_sap_pldr_ack_data *ack)
+{
+	struct iwl_mei *mei = mei_cldev_get_drvdata(cldev);
+
+	mei->pldr_active = le32_to_cpu(ack->status) == SAP_PLDR_STATUS_SUCCESS;
+	wake_up_all(&mei->pldr_wq);
+}
+
 static void iwl_mei_handle_ping(struct mei_cl_device *cldev,
 				const struct iwl_sap_hdr *hdr)
 {
@@ -961,6 +974,8 @@ static void iwl_mei_handle_sap_msg(struct mei_cl_device *cldev,
 			iwl_mei_handle_can_release_ownership, 0);
 	SAP_MSG_HANDLER(CSME_TAKING_OWNERSHIP,
 			iwl_mei_handle_csme_taking_ownership, 0);
+	SAP_MSG_HANDLER(PLDR_ACK, iwl_mei_handle_pldr_ack,
+			sizeof(struct iwl_sap_pldr_ack_data));
 	default:
 	/*
 	 * This is not really an error, there are message that we decided
@@ -1337,6 +1352,62 @@ out:
 }
 EXPORT_SYMBOL_GPL(iwl_mei_get_nvm);
 
+#define IWL_MEI_PLDR_NUM_RETRIES	3
+
+int iwl_mei_pldr_req(void)
+{
+	struct iwl_mei *mei;
+	int ret;
+	struct iwl_sap_pldr_data msg = {
+		.hdr.type = cpu_to_le16(SAP_MSG_NOTIF_PLDR),
+		.hdr.len = cpu_to_le16(sizeof(msg) - sizeof(msg.hdr)),
+	};
+	int i;
+
+	mutex_lock(&iwl_mei_mutex);
+
+	/* In case we didn't have a bind */
+	if (!iwl_mei_is_connected()) {
+		ret = 0;
+		goto out;
+	}
+
+	mei = mei_cldev_get_drvdata(iwl_mei_global_cldev);
+
+	if (!mei) {
+		ret = -ENODEV;
+		goto out;
+	}
+
+	if (!mei->amt_enabled) {
+		ret = 0;
+		goto out;
+	}
+
+	for (i = 0; i < IWL_MEI_PLDR_NUM_RETRIES; i++) {
+		ret = iwl_mei_send_sap_msg_payload(mei->cldev, &msg.hdr);
+		mutex_unlock(&iwl_mei_mutex);
+		if (ret)
+			return ret;
+
+		ret = wait_event_timeout(mei->pldr_wq, mei->pldr_active, HZ / 2);
+		if (ret)
+			break;
+
+		/* Take the mutex for the next iteration */
+		mutex_lock(&iwl_mei_mutex);
+	}
+
+	if (ret)
+		return 0;
+
+	ret = -ETIMEDOUT;
+out:
+	mutex_unlock(&iwl_mei_mutex);
+	return ret;
+}
+EXPORT_SYMBOL_GPL(iwl_mei_pldr_req);
+
 int iwl_mei_get_ownership(void)
 {
 	struct iwl_mei *mei;
@@ -1402,6 +1473,33 @@ out:
 }
 EXPORT_SYMBOL_GPL(iwl_mei_get_ownership);
 
+void iwl_mei_alive_notif(bool success)
+{
+	struct iwl_mei *mei;
+	struct iwl_sap_pldr_end_data msg = {
+		.hdr.type = cpu_to_le16(SAP_MSG_NOTIF_PLDR_END),
+		.hdr.len = cpu_to_le16(sizeof(msg) - sizeof(msg.hdr)),
+		.status = success ? cpu_to_le32(SAP_PLDR_STATUS_SUCCESS) :
+			cpu_to_le32(SAP_PLDR_STATUS_FAILURE),
+	};
+
+	mutex_lock(&iwl_mei_mutex);
+
+	if (!iwl_mei_is_connected())
+		goto out;
+
+	mei = mei_cldev_get_drvdata(iwl_mei_global_cldev);
+	if (!mei || !mei->pldr_active)
+		goto out;
+
+	mei->pldr_active = false;
+
+	iwl_mei_send_sap_msg_payload(mei->cldev, &msg.hdr);
+out:
+	mutex_unlock(&iwl_mei_mutex);
+}
+EXPORT_SYMBOL_GPL(iwl_mei_alive_notif);
+
 void iwl_mei_host_associated(const struct iwl_mei_conn_info *conn_info,
 			     const struct iwl_mei_colloc_info *colloc_info)
 {
@@ -1841,6 +1939,7 @@ static int iwl_mei_probe(struct mei_cl_device *cldev,
 	INIT_DELAYED_WORK(&mei->csa_throttle_end_wk,
 			  iwl_mei_csa_throttle_end_wk);
 	init_waitqueue_head(&mei->get_ownership_wq);
+	init_waitqueue_head(&mei->pldr_wq);
 	spin_lock_init(&mei->data_q_lock);
 	INIT_WORK(&mei->netdev_work, iwl_mei_netdev_work);
 
@@ -2013,6 +2112,7 @@ static void iwl_mei_remove(struct mei_cl_device *cldev)
 	 * the device.
 	 */
 	wake_up_all(&mei->get_ownership_wq);
+	wake_up_all(&mei->pldr_wq);
 
 	mutex_lock(&iwl_mei_mutex);