v4.19.13 snapshot.
diff --git a/drivers/xen/gntdev-common.h b/drivers/xen/gntdev-common.h
new file mode 100644
index 0000000..2f8b949
--- /dev/null
+++ b/drivers/xen/gntdev-common.h
@@ -0,0 +1,94 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+
+/*
+ * Common functionality of grant device.
+ *
+ * Copyright (c) 2006-2007, D G Murray.
+ * (c) 2009 Gerd Hoffmann <kraxel@redhat.com>
+ * (c) 2018 Oleksandr Andrushchenko, EPAM Systems Inc.
+ */
+
+#ifndef _GNTDEV_COMMON_H
+#define _GNTDEV_COMMON_H
+
+#include <linux/mm.h>
+#include <linux/mman.h>
+#include <linux/mmu_notifier.h>
+#include <linux/types.h>
+
+struct gntdev_dmabuf_priv;
+
+struct gntdev_priv {
+ /* Maps with visible offsets in the file descriptor. */
+ struct list_head maps;
+ /*
+ * Maps that are not visible; will be freed on munmap.
+ * Only populated if populate_freeable_maps == 1
+ */
+ struct list_head freeable_maps;
+ /* lock protects maps and freeable_maps. */
+ struct mutex lock;
+ struct mm_struct *mm;
+ struct mmu_notifier mn;
+
+#ifdef CONFIG_XEN_GRANT_DMA_ALLOC
+ /* Device for which DMA memory is allocated. */
+ struct device *dma_dev;
+#endif
+
+#ifdef CONFIG_XEN_GNTDEV_DMABUF
+ struct gntdev_dmabuf_priv *dmabuf_priv;
+#endif
+};
+
+struct gntdev_unmap_notify {
+ int flags;
+ /* Address relative to the start of the gntdev_grant_map. */
+ int addr;
+ int event;
+};
+
+struct gntdev_grant_map {
+ struct list_head next;
+ struct vm_area_struct *vma;
+ int index;
+ int count;
+ int flags;
+ refcount_t users;
+ struct gntdev_unmap_notify notify;
+ struct ioctl_gntdev_grant_ref *grants;
+ struct gnttab_map_grant_ref *map_ops;
+ struct gnttab_unmap_grant_ref *unmap_ops;
+ struct gnttab_map_grant_ref *kmap_ops;
+ struct gnttab_unmap_grant_ref *kunmap_ops;
+ struct page **pages;
+ unsigned long pages_vm_start;
+
+#ifdef CONFIG_XEN_GRANT_DMA_ALLOC
+ /*
+ * If dmabuf_vaddr is not NULL then this mapping is backed by DMA
+ * capable memory.
+ */
+
+ struct device *dma_dev;
+ /* Flags used to create this DMA buffer: GNTDEV_DMA_FLAG_XXX. */
+ int dma_flags;
+ void *dma_vaddr;
+ dma_addr_t dma_bus_addr;
+ /* Needed to avoid allocation in gnttab_dma_free_pages(). */
+ xen_pfn_t *frames;
+#endif
+};
+
+struct gntdev_grant_map *gntdev_alloc_map(struct gntdev_priv *priv, int count,
+ int dma_flags);
+
+void gntdev_add_map(struct gntdev_priv *priv, struct gntdev_grant_map *add);
+
+void gntdev_put_map(struct gntdev_priv *priv, struct gntdev_grant_map *map);
+
+bool gntdev_account_mapped_pages(int count);
+
+int gntdev_map_grant_pages(struct gntdev_grant_map *map);
+
+#endif