mei: implement async notification hbm messages

Implement sending and reception handlers for the
async event notification hbm commands.
Add client notification book keeping data required for the messages
    notify_en to indicate whether notification is enabled
    notify_ev to indicate whether an event is pending

Signed-off-by: Tomas Winkler <tomas.winkler@intel.com>
Signed-off-by: Alexander Usyskin <alexander.usyskin@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/misc/mei/hbm.c

@@ -402,6 +402,125 @@ static int mei_hbm_fw_add_cl_req(struct mei_device *dev,
 	return mei_hbm_add_cl_resp(dev, req->me_addr, status);
 }
 
+/**
+ * mei_hbm_cl_notify_req - send notification request
+ *
+ * @dev: the device structure
+ * @cl: a client to disconnect from
+ * @start: true for start false for stop
+ *
+ * Return: 0 on success and -EIO on write failure
+ */
+int mei_hbm_cl_notify_req(struct mei_device *dev,
+			  struct mei_cl *cl, u8 start)
+{
+
+	struct mei_msg_hdr *mei_hdr = &dev->wr_msg.hdr;
+	struct hbm_notification_request *req;
+	const size_t len = sizeof(struct hbm_notification_request);
+	int ret;
+
+	mei_hbm_hdr(mei_hdr, len);
+	mei_hbm_cl_hdr(cl, MEI_HBM_NOTIFY_REQ_CMD, dev->wr_msg.data, len);
+
+	req = (struct hbm_notification_request *)dev->wr_msg.data;
+	req->start = start;
+
+	ret = mei_write_message(dev, mei_hdr, dev->wr_msg.data);
+	if (ret)
+		dev_err(dev->dev, "notify request failed: ret = %d\n", ret);
+
+	return ret;
+}
+
+/**
+ *  notify_res_to_fop - convert notification response to the proper
+ *      notification FOP
+ *
+ * @cmd: client notification start response command
+ *
+ * Return:  MEI_FOP_NOTIFY_START or MEI_FOP_NOTIFY_STOP;
+ */
+static inline enum mei_cb_file_ops notify_res_to_fop(struct mei_hbm_cl_cmd *cmd)
+{
+	struct hbm_notification_response *rs =
+		(struct hbm_notification_response *)cmd;
+
+	if (rs->start == MEI_HBM_NOTIFICATION_START)
+		return MEI_FOP_NOTIFY_START;
+	else
+		return MEI_FOP_NOTIFY_STOP;
+}
+
+/**
+ * mei_hbm_cl_notify_start_res - update the client state according
+ *       notify start response
+ *
+ * @dev: the device structure
+ * @cl: mei host client
+ * @cmd: client notification start response command
+ */
+static void mei_hbm_cl_notify_start_res(struct mei_device *dev,
+					struct mei_cl *cl,
+					struct mei_hbm_cl_cmd *cmd)
+{
+	struct hbm_notification_response *rs =
+		(struct hbm_notification_response *)cmd;
+
+	cl_dbg(dev, cl, "hbm: notify start response status=%d\n", rs->status);
+
+	if (rs->status == MEI_HBMS_SUCCESS ||
+	    rs->status == MEI_HBMS_ALREADY_STARTED) {
+		cl->notify_en = true;
+		cl->status = 0;
+	} else {
+		cl->status = -EINVAL;
+	}
+}
+
+/**
+ * mei_hbm_cl_notify_stop_res - update the client state according
+ *       notify stop response
+ *
+ * @dev: the device structure
+ * @cl: mei host client
+ * @cmd: client notification stop response command
+ */
+static void mei_hbm_cl_notify_stop_res(struct mei_device *dev,
+				       struct mei_cl *cl,
+				       struct mei_hbm_cl_cmd *cmd)
+{
+	struct hbm_notification_response *rs =
+		(struct hbm_notification_response *)cmd;
+
+	cl_dbg(dev, cl, "hbm: notify stop response status=%d\n", rs->status);
+
+	if (rs->status == MEI_HBMS_SUCCESS ||
+	    rs->status == MEI_HBMS_NOT_STARTED) {
+		cl->notify_en = false;
+		cl->status = 0;
+	} else {
+		/* TODO: spec is not clear yet about other possible issues */
+		cl->status = -EINVAL;
+	}
+}
+
+/**
+ * mei_hbm_cl_notify - signal notification event
+ *
+ * @dev: the device structure
+ * @cmd: notification client message
+ */
+static void mei_hbm_cl_notify(struct mei_device *dev,
+			      struct mei_hbm_cl_cmd *cmd)
+{
+	struct mei_cl *cl;
+
+	cl = mei_hbm_cl_find_by_cmd(dev, cmd);
+	if (cl && cl->notify_en)
+		cl->notify_ev = true;
+}
+
 /**
  * mei_hbm_prop_req - request property for a single client
  *
@@ -716,6 +835,12 @@ static void mei_hbm_cl_res(struct mei_device *dev,
 	case MEI_FOP_DISCONNECT:
 		mei_hbm_cl_disconnect_res(dev, cl, rs);
 		break;
+	case MEI_FOP_NOTIFY_START:
+		mei_hbm_cl_notify_start_res(dev, cl, rs);
+		break;
+	case MEI_FOP_NOTIFY_STOP:
+		mei_hbm_cl_notify_stop_res(dev, cl, rs);
+		break;
 	default:
 		return;
 	}
@@ -1031,6 +1156,16 @@ int mei_hbm_dispatch(struct mei_device *dev, struct mei_msg_hdr *hdr)
 		dev_dbg(dev->dev, "hbm: add client request processed\n");
 		break;
 
+	case MEI_HBM_NOTIFY_RES_CMD:
+		dev_dbg(dev->dev, "hbm: notify response received\n");
+		mei_hbm_cl_res(dev, cl_cmd, notify_res_to_fop(cl_cmd));
+		break;
+
+	case MEI_HBM_NOTIFICATION_CMD:
+		dev_dbg(dev->dev, "hbm: notification\n");
+		mei_hbm_cl_notify(dev, cl_cmd);
+		break;
+
 	default:
 		BUG();
 		break;

drivers/misc/mei/hbm.h

@@ -54,6 +54,8 @@ int mei_hbm_cl_disconnect_rsp(struct mei_device *dev, struct mei_cl *cl);
 int mei_hbm_cl_connect_req(struct mei_device *dev, struct mei_cl *cl);
 bool mei_hbm_version_is_supported(struct mei_device *dev);
 int mei_hbm_pg(struct mei_device *dev, u8 pg_cmd);
+int mei_hbm_cl_notify_req(struct mei_device *dev,
+			  struct mei_cl *cl, u8 request);
 
 #endif /* _MEI_HBM_H_ */
 

drivers/misc/mei/mei_dev.h

@@ -136,6 +136,8 @@ enum mei_wd_states {
  * @MEI_FOP_CONNECT:    connect
  * @MEI_FOP_DISCONNECT: disconnect
  * @MEI_FOP_DISCONNECT_RSP: disconnect response
+ * @MEI_FOP_NOTIFY_START:   start notification
+ * @MEI_FOP_NOTIFY_STOP:    stop notification
  */
 enum mei_cb_file_ops {
 	MEI_FOP_READ = 0,
@@ -143,6 +145,8 @@ enum mei_cb_file_ops {
 	MEI_FOP_CONNECT,
 	MEI_FOP_DISCONNECT,
 	MEI_FOP_DISCONNECT_RSP,
+	MEI_FOP_NOTIFY_START,
+	MEI_FOP_NOTIFY_STOP,
 };
 
 /*
@@ -237,6 +241,8 @@ struct mei_cl_cb {
  * @mei_flow_ctrl_creds: transmit flow credentials
  * @timer_count:  watchdog timer for operation completion
  * @reserved: reserved for alignment
+ * @notify_en: notification - enabled/disabled
+ * @notify_ev: pending notification event
  * @writing_state: state of the tx
  * @rd_pending: pending read credits
  * @rd_completed: completed read
@@ -256,6 +262,8 @@ struct mei_cl {
 	u8 mei_flow_ctrl_creds;
 	u8 timer_count;
 	u8 reserved;
+	u8 notify_en;
+	u8 notify_ev;
 	enum mei_file_transaction_states writing_state;
 	struct list_head rd_pending;
 	struct list_head rd_completed;