Merge branch 'for-5.1/nfit/ars' into libnvdimm-for-next

Merge several updates to the ARS implementation. Highlights include:

* Support retrieval of short-ARS results if the ARS state is "requires
  continuation", and even if the "no_init_ars" module parameter is
  specified.
* Allow busy-polling of the kernel ARS state by allowing root to reset
  the exponential back-off timer.
* Filter potentially stale ARS results by tracking query-ARS relative to
  the previous start-ARS.

include/uapi/linux/virtio_config.h

@@ -78,6 +78,12 @@
 /* This feature indicates support for the packed virtqueue layout. */
 #define VIRTIO_F_RING_PACKED		34
 
+/*
+ * This feature indicates that memory accesses by the driver and the
+ * device are ordered in a way described by the platform.
+ */
+#define VIRTIO_F_ORDER_PLATFORM		36
+
 /*
  * Does the device support Single Root I/O Virtualization?
  */

include/uapi/linux/virtio_ring.h

@@ -213,14 +213,4 @@ struct vring_packed_desc {
 	__le16 flags;
 };
 
-struct vring_packed {
-	unsigned int num;
-
-	struct vring_packed_desc *desc;
-
-	struct vring_packed_desc_event *driver;
-
-	struct vring_packed_desc_event *device;
-};
-
 #endif /* _UAPI_LINUX_VIRTIO_RING_H */