mei: implement fasync for event notification

A process can be informed about client notification also via
SIGIO with POLL_PRI event.

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

drivers/misc/mei/client.c

@@ -1350,6 +1350,33 @@ out:
 	return rets;
 }
 
+/**
+ * mei_cl_notify - raise notification
+ *
+ * @cl: host client
+ *
+ * Locking: called under "dev->device_lock" lock
+ */
+void mei_cl_notify(struct mei_cl *cl)
+{
+	struct mei_device *dev;
+
+	if (!cl || !cl->dev)
+		return;
+
+	dev = cl->dev;
+
+	if (!cl->notify_en)
+		return;
+
+	cl_dbg(dev, cl, "notify event");
+	cl->notify_ev = true;
+	wake_up_interruptible_all(&cl->ev_wait);
+
+	if (cl->ev_async)
+		kill_fasync(&cl->ev_async, SIGIO, POLL_PRI);
+}
+
 /**
  * mei_cl_notify_get - get or wait for notification event
  *

drivers/misc/mei/client.h

@@ -225,6 +225,7 @@ int mei_cl_notify_request(struct mei_cl *cl, struct file *file, u8 request);
 int mei_cl_irq_notify(struct mei_cl *cl, struct mei_cl_cb *cb,
 		      struct mei_cl_cb *cmpl_list);
 int mei_cl_notify_get(struct mei_cl *cl, bool block, bool *notify_ev);
+void mei_cl_notify(struct mei_cl *cl);
 
 void mei_cl_all_disconnect(struct mei_device *dev);
 void mei_cl_all_wakeup(struct mei_device *dev);

drivers/misc/mei/hbm.c

@@ -514,10 +514,8 @@ static void mei_hbm_cl_notify(struct mei_device *dev,
 	struct mei_cl *cl;
 
 	cl = mei_hbm_cl_find_by_cmd(dev, cmd);
-	if (cl && cl->notify_en) {
-		cl->notify_ev = true;
-		wake_up_interruptible(&cl->ev_wait);
-	}
+	if (cl)
+		mei_cl_notify(cl);
 }
 
 /**

drivers/misc/mei/main.c

@@ -650,6 +650,26 @@ out:
 	return mask;
 }
 
+/**
+ * mei_fasync - asynchronous io support
+ *
+ * @fd: file descriptor
+ * @file: pointer to file structure
+ * @band: band bitmap
+ *
+ * Return: poll mask
+ */
+static int mei_fasync(int fd, struct file *file, int band)
+{
+
+	struct mei_cl *cl = file->private_data;
+
+	if (!mei_cl_is_connected(cl))
+		return POLLERR;
+
+	return fasync_helper(fd, file, band, &cl->ev_async);
+}
+
 /**
  * fw_status_show - mei device attribute show method
  *
@@ -702,6 +722,7 @@ static const struct file_operations mei_fops = {
 	.release = mei_release,
 	.write = mei_write,
 	.poll = mei_poll,
+	.fasync = mei_fasync,
 	.llseek = no_llseek
 };
 

drivers/misc/mei/mei_dev.h

@@ -236,6 +236,7 @@ struct mei_cl_cb {
  * @rx_wait: wait queue for rx completion
  * @wait:  wait queue for management operation
  * @ev_wait: notification wait queue
+ * @ev_async: event async notification
  * @status: connection status
  * @me_cl: fw client connected
  * @host_client_id: host id
@@ -258,6 +259,7 @@ struct mei_cl {
 	wait_queue_head_t rx_wait;
 	wait_queue_head_t wait;
 	wait_queue_head_t ev_wait;
+	struct fasync_struct *ev_async;
 	int status;
 	struct mei_me_client *me_cl;
 	u8 host_client_id;