greybus: hd: move CPort allocation to host-device code

Move host-device CPort allocation to the host-device code.

Proper CPort allocation requires knowledge of the hardware and must be
handled by the host-device driver. This is an intermediate step that
moves the generic CPort-allocation code to the host-device code.
Signed-off-by: Johan Hovold <johan@hovoldconsulting.com>
Reviewed-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>

drivers/staging/greybus/connection.c

@@ -142,21 +142,8 @@ _gb_connection_create(struct gb_host_device *hd, int hd_cport_id,
 				unsigned long flags)
 {
 	struct gb_connection *connection;
-	struct ida *id_map = &hd->cport_id_map;
-	int ida_start, ida_end;
 	int ret;
 
-	if (hd_cport_id < 0) {
-		ida_start = 0;
-		ida_end = hd->num_cports;
-	} else if (hd_cport_id < hd->num_cports) {
-		ida_start = hd_cport_id;
-		ida_end = hd_cport_id + 1;
-	} else {
-		dev_err(&hd->dev, "cport %d not available\n", hd_cport_id);
-		return ERR_PTR(-EINVAL);
-	}
-
 	mutex_lock(&gb_connection_mutex);
 
 	if (intf && gb_connection_intf_find(intf, cport_id)) {
@@ -165,15 +152,17 @@ _gb_connection_create(struct gb_host_device *hd, int hd_cport_id,
 		goto err_unlock;
 	}
 
-	ret = ida_simple_get(id_map, ida_start, ida_end, GFP_KERNEL);
-	if (ret < 0)
+	ret = gb_hd_cport_allocate(hd, hd_cport_id);
+	if (ret < 0) {
+		dev_err(&hd->dev, "failed to allocate cport: %d\n", ret);
 		goto err_unlock;
+	}
 	hd_cport_id = ret;
 
 	connection = kzalloc(sizeof(*connection), GFP_KERNEL);
 	if (!connection) {
 		ret = -ENOMEM;
-		goto err_remove_ida;
+		goto err_hd_cport_release;
 	}
 
 	connection->hd_cport_id = hd_cport_id;
@@ -219,8 +208,8 @@ _gb_connection_create(struct gb_host_device *hd, int hd_cport_id,
 
 err_free_connection:
 	kfree(connection);
-err_remove_ida:
-	ida_simple_remove(id_map, hd_cport_id);
+err_hd_cport_release:
+	gb_hd_cport_release(hd, hd_cport_id);
 err_unlock:
 	mutex_unlock(&gb_connection_mutex);
 
@@ -658,8 +647,6 @@ EXPORT_SYMBOL_GPL(gb_connection_disable);
 /* Caller must have disabled the connection before destroying it. */
 void gb_connection_destroy(struct gb_connection *connection)
 {
-	struct ida *id_map;
-
 	if (!connection)
 		return;
 
@@ -672,8 +659,7 @@ void gb_connection_destroy(struct gb_connection *connection)
 
 	destroy_workqueue(connection->wq);
 
-	id_map = &connection->hd->cport_id_map;
-	ida_simple_remove(id_map, connection->hd_cport_id);
+	gb_hd_cport_release(connection->hd, connection->hd_cport_id);
 	connection->hd_cport_id = CPORT_ID_BAD;
 
 	mutex_unlock(&gb_connection_mutex);

drivers/staging/greybus/hd.c

@@ -39,6 +39,32 @@ static struct attribute *bus_attrs[] = {
 };
 ATTRIBUTE_GROUPS(bus);
 
+/* Locking: Caller guarantees serialisation */
+int gb_hd_cport_allocate(struct gb_host_device *hd, int cport_id)
+{
+	struct ida *id_map = &hd->cport_id_map;
+	int ida_start, ida_end;
+
+	if (cport_id < 0) {
+		ida_start = 0;
+		ida_end = hd->num_cports;
+	} else if (cport_id < hd->num_cports) {
+		ida_start = cport_id;
+		ida_end = cport_id + 1;
+	} else {
+		dev_err(&hd->dev, "cport %d not available\n", cport_id);
+		return -EINVAL;
+	}
+
+	return ida_simple_get(id_map, ida_start, ida_end, GFP_KERNEL);
+}
+
+/* Locking: Caller guarantees serialisation */
+void gb_hd_cport_release(struct gb_host_device *hd, u16 cport_id)
+{
+	ida_simple_remove(&hd->cport_id_map, cport_id);
+}
+
 static void gb_hd_release(struct device *dev)
 {
 	struct gb_host_device *hd = to_gb_host_device(dev);

drivers/staging/greybus/hd.h

@@ -50,6 +50,9 @@ struct gb_host_device {
 };
 #define to_gb_host_device(d) container_of(d, struct gb_host_device, dev)
 
+int gb_hd_cport_allocate(struct gb_host_device *hd, int cport_id);
+void gb_hd_cport_release(struct gb_host_device *hd, u16 cport_id);
+
 struct gb_host_device *gb_hd_create(struct gb_hd_driver *driver,
 					struct device *parent,
 					size_t buffer_size_max,