virtio: blk: Add freeze, restore handlers to support S4
Delete the vq and flush any pending requests from the block queue on the
freeze callback to prepare for hibernation.
Re-create the vq in the restore callback to resume normal function.
Signed-off-by: Amit Shah <amit.shah@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
diff --git a/drivers/block/virtio_blk.c b/drivers/block/virtio_blk.c
index e8af523..ffd5ca9 100644
--- a/drivers/block/virtio_blk.c
+++ b/drivers/block/virtio_blk.c
@@ -588,6 +588,46 @@
ida_simple_remove(&vd_index_ida, index);
}
+#ifdef CONFIG_PM
+static int virtblk_freeze(struct virtio_device *vdev)
+{
+ struct virtio_blk *vblk = vdev->priv;
+
+ /* Ensure we don't receive any more interrupts */
+ vdev->config->reset(vdev);
+
+ /* Prevent config work handler from accessing the device. */
+ mutex_lock(&vblk->config_lock);
+ vblk->config_enable = false;
+ mutex_unlock(&vblk->config_lock);
+
+ flush_work(&vblk->config_work);
+
+ spin_lock_irq(vblk->disk->queue->queue_lock);
+ blk_stop_queue(vblk->disk->queue);
+ spin_unlock_irq(vblk->disk->queue->queue_lock);
+ blk_sync_queue(vblk->disk->queue);
+
+ vdev->config->del_vqs(vdev);
+ return 0;
+}
+
+static int virtblk_restore(struct virtio_device *vdev)
+{
+ struct virtio_blk *vblk = vdev->priv;
+ int ret;
+
+ vblk->config_enable = true;
+ ret = init_vq(vdev->priv);
+ if (!ret) {
+ spin_lock_irq(vblk->disk->queue->queue_lock);
+ blk_start_queue(vblk->disk->queue);
+ spin_unlock_irq(vblk->disk->queue->queue_lock);
+ }
+ return ret;
+}
+#endif
+
static const struct virtio_device_id id_table[] = {
{ VIRTIO_ID_BLOCK, VIRTIO_DEV_ANY_ID },
{ 0 },
@@ -613,6 +653,10 @@
.probe = virtblk_probe,
.remove = __devexit_p(virtblk_remove),
.config_changed = virtblk_config_changed,
+#ifdef CONFIG_PM
+ .freeze = virtblk_freeze,
+ .restore = virtblk_restore,
+#endif
};
static int __init init(void)