As that function is in code only there to provide compile coverage
something like this should fix the problem:
diff --git a/arch/sparc/include/asm/pgtable_64.h b/arch/sparc/include/asm/pgtable_64.h
index 547ff96fb228..1599de730532 100644
--- a/arch/sparc/include/asm/pgtable_64.h
+++ b/arch/sparc/include/asm/pgtable_64.h
@@ -861,10 +861,12 @@ static inline unsigned long pud_page_vaddr(pud_t pud)
#define pud_clear(pudp) (pud_val(*(pudp)) = 0UL)
#define pgd_page_vaddr(pgd) \
((unsigned long) __va(pgd_val(pgd)))
-#define pgd_page(pgd) pfn_to_page(pgd_pfn(pgd))
#define pgd_present(pgd) (pgd_val(pgd) != 0U)
#define pgd_clear(pgdp) (pgd_val(*(pgdp)) = 0UL)
+/* only used by the stubbed out hugetlb gup code, should never be called */
+#define pgd_page(pgd) NULL
+
static inline unsigned long pud_large(pud_t pud)
{
pte_t pte = __pte(pud_val(pud));
