1 files changed, 11 insertions, 15 deletions

diff --git a/drivers/char/virtio_console.c b/drivers/char/virtio_console.c
index 9fa3c76a267f..6a821118d553 100644
--- a/drivers/char/virtio_console.c
+++ b/drivers/char/virtio_console.c
@@ -13,6 +13,7 @@
 #include <linux/fs.h>
 #include <linux/splice.h>
 #include <linux/pagemap.h>
+#include <linux/idr.h>
 #include <linux/init.h>
 #include <linux/list.h>
 #include <linux/poll.h>
@@ -48,22 +49,11 @@ struct ports_driver_data {
 	/* List of all the devices we're handling */
 	struct list_head portdevs;
 
-	/*
-	 * This is used to keep track of the number of hvc consoles
-	 * spawned by this driver.  This number is given as the first
-	 * argument to hvc_alloc().  To correctly map an initial
-	 * console spawned via hvc_instantiate to the console being
-	 * hooked up via hvc_alloc, we need to pass the same vtermno.
-	 *
-	 * We also just assume the first console being initialised was
-	 * the first one that got used as the initial console.
-	 */
-	unsigned int next_vtermno;
-
 	/* All the console devices handled by this driver */
 	struct list_head consoles;
 };
-static struct ports_driver_data pdrvdata = { .next_vtermno = 1};
+
+static struct ports_driver_data pdrvdata;
 
 static DEFINE_SPINLOCK(pdrvdata_lock);
 static DECLARE_COMPLETION(early_console_added);
@@ -89,6 +79,8 @@ struct console {
 	u32 vtermno;
 };
 
+static DEFINE_IDA(vtermno_ida);
+
 struct port_buffer {
 	char *buf;
 
@@ -1244,18 +1236,21 @@ static int init_port_console(struct port *port)
 	 * pointers.  The final argument is the output buffer size: we
 	 * can do any size, so we put PAGE_SIZE here.
 	 */
-	port->cons.vtermno = pdrvdata.next_vtermno;
+	ret = ida_alloc_min(&vtermno_ida, 1, GFP_KERNEL);
+	if (ret < 0)
+		return ret;
 
+	port->cons.vtermno = ret;
 	port->cons.hvc = hvc_alloc(port->cons.vtermno, 0, &hv_ops, PAGE_SIZE);
 	if (IS_ERR(port->cons.hvc)) {
 		ret = PTR_ERR(port->cons.hvc);
 		dev_err(port->dev,
 			"error %d allocating hvc for port\n", ret);
 		port->cons.hvc = NULL;
+		ida_free(&vtermno_ida, port->cons.vtermno);
 		return ret;
 	}
 	spin_lock_irq(&pdrvdata_lock);
-	pdrvdata.next_vtermno++;
 	list_add_tail(&port->cons.list, &pdrvdata.consoles);
 	spin_unlock_irq(&pdrvdata_lock);
 	port->guest_connected = true;
@@ -1532,6 +1527,7 @@ static void unplug_port(struct port *port)
 		list_del(&port->cons.list);
 		spin_unlock_irq(&pdrvdata_lock);
 		hvc_remove(port->cons.hvc);
+		ida_free(&vtermno_ida, port->cons.vtermno);
 	}
 
 	remove_port_data(port);