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 | 78 +++++++++++++++++++++++++++++++++++++---
1 files changed, 72 insertions(+), 6 deletions(-)
diff --git a/drivers/char/virtio_console.c b/drivers/char/virtio_console.c
index 0be5562..36cd7d4 100644
--- a/drivers/char/virtio_console.c
+++ b/drivers/char/virtio_console.c
@@ -105,6 +105,7 @@ struct ports_device {
* notification
*/
struct work_struct control_work;
+ struct work_struct config_work;
struct list_head ports;
@@ -695,11 +696,6 @@ 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)
{
@@ -960,6 +956,24 @@ static void control_intr(struct virtqueue *vq)
schedule_work(&portdev->control_work);
}
+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 void fill_queue(struct virtqueue *vq, spinlock_t *lock)
{
struct port_buffer *buf;
@@ -1080,6 +1094,57 @@ fail:
return err;
}
+/*
+ * The workhandler for config-space updates.
+ *
+ * This is called when ports are hot-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 tell the Host
+ * that the port is ready.
+ */
+ struct port *port;
+
+ port = find_port_by_id(portdev, 0);
+ send_control_msg(port, VIRTIO_CONSOLE_PORT_READY, 1);
+ return;
+ }
+ if (virtconconf.nr_ports > portdev->config.max_nr_ports) {
+ dev_warn(&vdev->dev,
+ "More ports specified (%u) than allowed (%u)",
+ portdev->config.nr_ports + 1,
+ portdev->config.max_nr_ports);
+ 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++;
+ }
+}
+
static int init_vqs(struct ports_device *portdev)
{
vq_callback_t **io_callbacks;
@@ -1270,6 +1335,7 @@ static int __devinit virtcons_probe(struct virtio_device *vdev)
if (multiport) {
spin_lock_init(&portdev->cvq_lock);
INIT_WORK(&portdev->control_work, &control_work_handler);
+ INIT_WORK(&portdev->config_work, &config_work_handler);
portdev->outbuf = alloc_buf(PAGE_SIZE);
if (!portdev->outbuf) {
@@ -1316,7 +1382,7 @@ 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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