From 7f5d810dac70214d00b2440787535b6c7a73b6b7 Mon Sep 17 00:00:00 2001 From: Amit Shah Date: Mon, 21 Dec 2009 22:22:08 +0530 Subject: virtio: console: Handle port hot-plug 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 Signed-off-by: Rusty Russell --- drivers/char/virtio_console.c | 78 +++++++++++++++++++++++++++++++++++++++---- 1 file changed, 72 insertions(+), 6 deletions(-) (limited to 'drivers/char/virtio_console.c') diff --git a/drivers/char/virtio_console.c b/drivers/char/virtio_console.c index 5506ff8bdf03..7c53f58c87ba 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; @@ -675,11 +676,6 @@ 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) { @@ -928,6 +924,24 @@ 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; @@ -1040,6 +1054,57 @@ 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; @@ -1230,6 +1295,7 @@ 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); fill_queue(portdev->c_ivq, &portdev->cvq_lock); } @@ -1266,7 +1332,7 @@ 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) -- cgit v1.2.2