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path: root/drivers/virtio/virtio.c
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Diffstat (limited to 'drivers/virtio/virtio.c')
-rw-r--r--drivers/virtio/virtio.c103
1 files changed, 103 insertions, 0 deletions
diff --git a/drivers/virtio/virtio.c b/drivers/virtio/virtio.c
index fed0ce198ae3..df598dd8c5c8 100644
--- 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)

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