If the 'nr_ports' variable in the config space is updated to
a higher value, that means new ports have been hotplugged.
Introduce a new workqueue to handle such updates and create
new ports.
Signed-off-by: Amit Shah <amit.shah@xxxxxxxxxx>
---
drivers/char/virtio_console.c | 73 +++++++++++++++++++++++++++++++++++++----
1 files changed, 66 insertions(+), 7 deletions(-)
diff --git a/drivers/char/virtio_console.c b/drivers/char/virtio_console.c
index 8fac9eb..47d84d7 100644
--- a/drivers/char/virtio_console.c
+++ b/drivers/char/virtio_console.c
@@ -96,6 +96,7 @@ struct ports_device {
* interrupt
*/
struct work_struct rx_work;
+ struct work_struct config_work;
struct list_head ports_head;
struct list_head unused_read_head;
@@ -640,11 +641,6 @@ static void resize_console(struct port *port)
}
}
-static void virtcons_apply_config(struct virtio_device *vdev)
-{
- resize_console(find_port_by_vtermno(0));
-}
-
/* We set the configuration at this point, since we now have a tty */
static int notifier_add_vio(struct hvc_struct *hp, int data)
{
@@ -1045,6 +1041,24 @@ static void tx_intr(struct virtqueue *vq)
spin_unlock_irqrestore(&portdev->write_list_lock, flags);
}
+static void config_intr(struct virtio_device *vdev)
+{
+ struct ports_device *portdev;
+
+ portdev = vdev->priv;
+ if (use_multiport(portdev)) {
+ /* Handle port hot-add */
+ schedule_work(&portdev->config_work);
+ }
+ /*
+ * We'll use this way of resizing only for legacy support. For
+ * newer userspace (VIRTIO_CONSOLE_F_MULTPORT+), use control
+ * messages to indicate console size changes so that it can be
+ * done per-port
+ */
+ resize_console(find_port_by_id(portdev, 0));
+}
+
static ssize_t show_port_name(struct device *dev,
struct device_attribute *attr, char *buffer)
{
@@ -1067,7 +1081,7 @@ static struct attribute_group port_attribute_group = {
.attrs = port_sysfs_entries,
};
-static int __devinit add_port(struct ports_device *portdev, u32 id)
+static int add_port(struct ports_device *portdev, u32 id)
{
struct port *port;
dev_t devt;
@@ -1143,6 +1157,50 @@ static struct file_operations portdev_fops = {
};
/*
+ * The workhandler for config-space updates
+ *
+ * This is used when new ports are added
+ */
+static void config_work_handler(struct work_struct *work)
+{
+ struct virtio_console_config virtconconf;
+ struct ports_device *portdev;
+ struct virtio_device *vdev;
+ int err;
+
+ portdev = container_of(work, struct ports_device, config_work);
+
+ vdev = portdev->vdev;
+ vdev->config->get(vdev,
+ offsetof(struct virtio_console_config, nr_ports),
+ &virtconconf.nr_ports,
+ sizeof(virtconconf.nr_ports));
+
+ if (portdev->config.nr_ports == virtconconf.nr_ports) {
+ /*
+ * Port 0 got hot-added. Since we already did all the other
+ * initialisation for it, just ask the Host for the name
+ * if set
+ */
+ struct port *port;
+
+ port = find_port_by_id(portdev, 0);
+ send_control_msg(port, VIRTIO_CONSOLE_PORT_NAME, 1);
+ return;
+ }
+ if (virtconconf.nr_ports < portdev->config.nr_ports)
+ return;
+
+ /* Hot-add ports */
+ while(virtconconf.nr_ports - portdev->config.nr_ports) {
+ err = add_port(portdev, portdev->config.nr_ports);
+ if (err)
+ break;
+ portdev->config.nr_ports++;
+ }
+}
+
+/*
* Once we're further in boot, we get probed like any other virtio
* device.
*
@@ -1210,6 +1268,7 @@ static int __devinit virtcons_probe(struct virtio_device *vdev)
INIT_LIST_HEAD(&portdev->unused_write_head);
INIT_WORK(&portdev->rx_work, &rx_work_handler);
+ INIT_WORK(&portdev->config_work, &config_work_handler);
fill_receive_queue(portdev);
alloc_write_bufs(portdev);
@@ -1248,7 +1307,7 @@ static struct virtio_driver virtio_console = {
.driver.owner = THIS_MODULE,
.id_table = id_table,
.probe = virtcons_probe,
- .config_changed = virtcons_apply_config,
+ .config_changed = config_intr,
};
static int __init init(void)
--
1.6.2.5
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