mm: rename p4d_page_vaddr to p4d_pgtable and make it return pud_t *

[ Upstream commit dc4875f0e7 ]

No functional change in this patch.

[aneesh.kumar@linux.ibm.com: m68k build error reported by kernel robot]
  Link: https://lkml.kernel.org/r/87tulxnb2v.fsf@linux.ibm.com

Link: https://lkml.kernel.org/r/20210615110859.320299-2-aneesh.kumar@linux.ibm.com
Link: https://lore.kernel.org/linuxppc-dev/CAHk-=wi+J+iodze9FtjM3Zi4j4OeS+qqbKxME9QN4roxPEXH9Q@mail.gmail.com/
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Cc: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: Hugh Dickins <hughd@google.com>
Cc: Joel Fernandes <joel@joelfernandes.org>
Cc: Kalesh Singh <kaleshsingh@google.com>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Stable-dep-of: 0da90af431 ("powerpc/book3s64/mm: Fix DirectMap stats in /proc/meminfo")
Signed-off-by: Sasha Levin <sashal@kernel.org>

arch/x86/mm/init_64.c

@@ -193,8 +193,8 @@ static void sync_global_pgds_l4(unsigned long start, unsigned long end)
 			spin_lock(pgt_lock);
 
 			if (!p4d_none(*p4d_ref) && !p4d_none(*p4d))
-				BUG_ON(p4d_page_vaddr(*p4d)
-				       != p4d_page_vaddr(*p4d_ref));
+				BUG_ON(p4d_pgtable(*p4d)
+				       != p4d_pgtable(*p4d_ref));
 
 			if (p4d_none(*p4d))
 				set_p4d(p4d, *p4d_ref);