+static inline bool pfn_in_hpage(struct page *hpage, unsigned long pfn)
+{
+ unsigned long hpage_pfn = page_to_pfn(hpage);
+
+ /* THP can be referenced by any subpage */
+ return pfn >= hpage_pfn && pfn - hpage_pfn < hpage_nr_pages(hpage);
+}
+
+/**
+ * check_pte - check if @pvmw->page is mapped at the @pvmw->pte
+ *
+ * page_vma_mapped_walk() found a place where @pvmw->page is *potentially*
+ * mapped. check_pte() has to validate this.
+ *
+ * @pvmw->pte may point to empty PTE, swap PTE or PTE pointing to arbitrary
+ * page.
+ *
+ * If PVMW_MIGRATION flag is set, returns true if @pvmw->pte contains migration
+ * entry that points to @pvmw->page or any subpage in case of THP.
+ *
+ * If PVMW_MIGRATION flag is not set, returns true if @pvmw->pte points to
+ * @pvmw->page or any subpage in case of THP.
+ *
+ * Otherwise, return false.
+ *
+ */