Merge tag 'mac80211-next-for-john-2014-11-04' of git://git.kernel.org/pub/scm/linux...

[cascardo/linux.git] / drivers / virtio / virtio.c

diff --git a/drivers/virtio/virtio.c b/drivers/virtio/virtio.c
index fed0ce1..df598dd 100644 (file)
--- a/drivers/virtio/virtio.c
+++ b/drivers/virtio/virtio.c
@@ -117,6 +117,43 @@ void virtio_check_driver_offered_feature(const struct virtio_device *vdev,
 }
 EXPORT_SYMBOL_GPL(virtio_check_driver_offered_feature);
 
+static void __virtio_config_changed(struct virtio_device *dev)
+{
+       struct virtio_driver *drv = drv_to_virtio(dev->dev.driver);
+
+       if (!dev->config_enabled)
+               dev->config_change_pending = true;
+       else if (drv && drv->config_changed)
+               drv->config_changed(dev);
+}
+
+void virtio_config_changed(struct virtio_device *dev)
+{
+       unsigned long flags;
+
+       spin_lock_irqsave(&dev->config_lock, flags);
+       __virtio_config_changed(dev);
+       spin_unlock_irqrestore(&dev->config_lock, flags);
+}
+EXPORT_SYMBOL_GPL(virtio_config_changed);
+
+static void virtio_config_disable(struct virtio_device *dev)
+{
+       spin_lock_irq(&dev->config_lock);
+       dev->config_enabled = false;
+       spin_unlock_irq(&dev->config_lock);
+}
+
+static void virtio_config_enable(struct virtio_device *dev)
+{
+       spin_lock_irq(&dev->config_lock);
+       dev->config_enabled = true;
+       if (dev->config_change_pending)
+               __virtio_config_changed(dev);
+       dev->config_change_pending = false;
+       spin_unlock_irq(&dev->config_lock);
+}
+
 static int virtio_dev_probe(struct device *_d)
 {
        int err, i;
@@ -153,6 +190,8 @@ static int virtio_dev_probe(struct device *_d)
                add_status(dev, VIRTIO_CONFIG_S_DRIVER_OK);
                if (drv->scan)
                        drv->scan(dev);
+
+               virtio_config_enable(dev);
        }
 
        return err;
@@ -163,6 +202,8 @@ static int virtio_dev_remove(struct device *_d)
        struct virtio_device *dev = dev_to_virtio(_d);
        struct virtio_driver *drv = drv_to_virtio(dev->dev.driver);
 
+       virtio_config_disable(dev);
+
        drv->remove(dev);
 
        /* Driver should have reset device. */
@@ -211,6 +252,10 @@ int register_virtio_device(struct virtio_device *dev)
        dev->index = err;
        dev_set_name(&dev->dev, "virtio%u", dev->index);
 
+       spin_lock_init(&dev->config_lock);
+       dev->config_enabled = false;
+       dev->config_change_pending = false;
+
        /* We always start by resetting the device, in case a previous
         * driver messed it up.  This also tests that code path a little. */
        dev->config->reset(dev);
@@ -239,6 +284,64 @@ void unregister_virtio_device(struct virtio_device *dev)
 }
 EXPORT_SYMBOL_GPL(unregister_virtio_device);
 
+#ifdef CONFIG_PM_SLEEP
+int virtio_device_freeze(struct virtio_device *dev)
+{
+       struct virtio_driver *drv = drv_to_virtio(dev->dev.driver);
+
+       virtio_config_disable(dev);
+
+       dev->failed = dev->config->get_status(dev) & VIRTIO_CONFIG_S_FAILED;
+
+       if (drv && drv->freeze)
+               return drv->freeze(dev);
+
+       return 0;
+}
+EXPORT_SYMBOL_GPL(virtio_device_freeze);
+
+int virtio_device_restore(struct virtio_device *dev)
+{
+       struct virtio_driver *drv = drv_to_virtio(dev->dev.driver);
+
+       /* We always start by resetting the device, in case a previous
+        * driver messed it up. */
+       dev->config->reset(dev);
+
+       /* Acknowledge that we've seen the device. */
+       add_status(dev, VIRTIO_CONFIG_S_ACKNOWLEDGE);
+
+       /* Maybe driver failed before freeze.
+        * Restore the failed status, for debugging. */
+       if (dev->failed)
+               add_status(dev, VIRTIO_CONFIG_S_FAILED);
+
+       if (!drv)
+               return 0;
+
+       /* We have a driver! */
+       add_status(dev, VIRTIO_CONFIG_S_DRIVER);
+
+       dev->config->finalize_features(dev);
+
+       if (drv->restore) {
+               int ret = drv->restore(dev);
+               if (ret) {
+                       add_status(dev, VIRTIO_CONFIG_S_FAILED);
+                       return ret;
+               }
+       }
+
+       /* Finally, tell the device we're all set */
+       add_status(dev, VIRTIO_CONFIG_S_DRIVER_OK);
+
+       virtio_config_enable(dev);
+
+       return 0;
+}
+EXPORT_SYMBOL_GPL(virtio_device_restore);
+#endif
+
 static int virtio_init(void)
 {
        if (bus_register(&virtio_bus) != 0)