From 2b8f41d846990c3c1c8addbaed2cf53c3ef91d25 Mon Sep 17 00:00:00 2001 From: Amit Shah Date: Thu, 22 Dec 2011 16:58:28 +0530 Subject: [PATCH] virtio: console: Add freeze and restore handlers to support S4 Remove all vqs and associated buffers in the freeze callback which prepares us to go into hibernation state. On restore, re-create all the vqs and populate the input vqs with buffers to get to the pre-hibernate state. Note: Any outstanding unconsumed buffers are discarded; which means there's a possibility of data loss in case the host or the guest didn't consume any data already present in the vqs. This can be addressed in a later patch series, perhaps in virtio common code. Signed-off-by: Amit Shah Signed-off-by: Rusty Russell --- drivers/char/virtio_console.c | 58 +++++++++++++++++++++++++++++++++++ 1 file changed, 58 insertions(+) diff --git a/drivers/char/virtio_console.c b/drivers/char/virtio_console.c index 9681ffd79904..614b84d38d7a 100644 --- a/drivers/char/virtio_console.c +++ b/drivers/char/virtio_console.c @@ -1844,6 +1844,60 @@ static unsigned int features[] = { VIRTIO_CONSOLE_F_MULTIPORT, }; +#ifdef CONFIG_PM +static int virtcons_freeze(struct virtio_device *vdev) +{ + struct ports_device *portdev; + struct port *port; + + portdev = vdev->priv; + + vdev->config->reset(vdev); + + cancel_work_sync(&portdev->control_work); + remove_controlq_data(portdev); + + list_for_each_entry(port, &portdev->ports, list) { + /* + * We'll ask the host later if the new invocation has + * the port opened or closed. + */ + port->host_connected = false; + remove_port_data(port); + } + remove_vqs(portdev); + + return 0; +} + +static int virtcons_restore(struct virtio_device *vdev) +{ + struct ports_device *portdev; + struct port *port; + int ret; + + portdev = vdev->priv; + + ret = init_vqs(portdev); + if (ret) + return ret; + + if (use_multiport(portdev)) + fill_queue(portdev->c_ivq, &portdev->cvq_lock); + + list_for_each_entry(port, &portdev->ports, list) { + port->in_vq = portdev->in_vqs[port->id]; + port->out_vq = portdev->out_vqs[port->id]; + + fill_queue(port->in_vq, &port->inbuf_lock); + + /* Get port open/close status on the host */ + send_control_msg(port, VIRTIO_CONSOLE_PORT_READY, 1); + } + return 0; +} +#endif + static struct virtio_driver virtio_console = { .feature_table = features, .feature_table_size = ARRAY_SIZE(features), @@ -1853,6 +1907,10 @@ static struct virtio_driver virtio_console = { .probe = virtcons_probe, .remove = virtcons_remove, .config_changed = config_intr, +#ifdef CONFIG_PM + .freeze = virtcons_freeze, + .restore = virtcons_restore, +#endif }; static int __init init(void) -- 2.20.1