microblaze: use pgtable-nopmd instead of 4level-fixup

microblaze has only two-level page tables and can use pgtable-nopmd and
folding of the upper layers.

Replace usage of include/asm-generic/4level-fixup.h and explicit
definition of __PAGETABLE_PMD_FOLDED in microblaze with
include/asm-generic/pgtable-nopmd.h and adjust page table manipulation
macros and functions accordingly.

Link: http://lkml.kernel.org/r/1572938135-31886-7-git-send-email-rppt@kernel.org
Signed-off-by: Mike Rapoport <rppt@linux.ibm.com>
Cc: Anatoly Pugachev <matorola@gmail.com>
Cc: Anton Ivanov <anton.ivanov@cambridgegreys.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Greentime Hu <green.hu@gmail.com>
Cc: Greg Ungerer <gerg@linux-m68k.org>
Cc: Helge Deller <deller@gmx.de>
Cc: "James E.J. Bottomley" <James.Bottomley@HansenPartnership.com>
Cc: Jeff Dike <jdike@addtoit.com>
Cc: "Kirill A. Shutemov" <kirill@shutemov.name>
Cc: Mark Salter <msalter@redhat.com>
Cc: Matt Turner <mattst88@gmail.com>
Cc: Michal Simek <monstr@monstr.eu>
Cc: Peter Rosin <peda@axentia.se>
Cc: Richard Weinberger <richard@nod.at>
Cc: Rolf Eike Beer <eike-kernel@sf-tec.de>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Russell King <rmk+kernel@armlinux.org.uk>
Cc: Sam Creasey <sammy@sammy.net>
Cc: Vincent Chen <deanbo422@gmail.com>
Cc: Vineet Gupta <Vineet.Gupta1@synopsys.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

arch/microblaze/include/asm/pgtable.h

@@ -59,9 +59,7 @@ extern int mem_init_done;
 
 #else /* CONFIG_MMU */
 
-#include <asm-generic/4level-fixup.h>
-
-#define __PAGETABLE_PMD_FOLDED 1
+#include <asm-generic/pgtable-nopmd.h>
 
 #ifdef __KERNEL__
 #ifndef __ASSEMBLY__
@@ -138,13 +136,8 @@ static inline pte_t pte_mkspecial(pte_t pte)	{ return pte; }
  *
  */
 
-/* PMD_SHIFT determines the size of the area mapped by the PTE pages */
-#define PMD_SHIFT	(PAGE_SHIFT + PTE_SHIFT)
-#define PMD_SIZE	(1UL << PMD_SHIFT)
-#define PMD_MASK	(~(PMD_SIZE-1))
-
 /* PGDIR_SHIFT determines what a top-level page table entry can map */
-#define PGDIR_SHIFT	PMD_SHIFT
+#define PGDIR_SHIFT	(PAGE_SHIFT + PTE_SHIFT)
 #define PGDIR_SIZE	(1UL << PGDIR_SHIFT)
 #define PGDIR_MASK	(~(PGDIR_SIZE-1))
 
@@ -165,9 +158,6 @@ static inline pte_t pte_mkspecial(pte_t pte)	{ return pte; }
 #define pte_ERROR(e) \
 	printk(KERN_ERR "%s:%d: bad pte "PTE_FMT".\n", \
 		__FILE__, __LINE__, pte_val(e))
-#define pmd_ERROR(e) \
-	printk(KERN_ERR "%s:%d: bad pmd %08lx.\n", \
-		__FILE__, __LINE__, pmd_val(e))
 #define pgd_ERROR(e) \
 	printk(KERN_ERR "%s:%d: bad pgd %08lx.\n", \
 		__FILE__, __LINE__, pgd_val(e))
@@ -313,18 +303,6 @@ extern unsigned long empty_zero_page[1024];
 	__pte(((pte_basic_t)(pfn) << PFN_SHIFT_OFFSET) | pgprot_val(prot))
 
 #ifndef __ASSEMBLY__
-/*
- * The "pgd_xxx()" functions here are trivial for a folded two-level
- * setup: the pgd is never bad, and a pmd always exists (as it's folded
- * into the pgd entry)
- */
-static inline int pgd_none(pgd_t pgd)		{ return 0; }
-static inline int pgd_bad(pgd_t pgd)		{ return 0; }
-static inline int pgd_present(pgd_t pgd)	{ return 1; }
-#define pgd_clear(xp)				do { } while (0)
-#define pgd_page(pgd) \
-	((unsigned long) __va(pgd_val(pgd) & PAGE_MASK))
-
 /*
  * The following only work if pte_present() is true.
  * Undefined behaviour if not..
@@ -479,12 +457,6 @@ static inline void ptep_mkdirty(struct mm_struct *mm,
 #define pgd_index(address)	 ((address) >> PGDIR_SHIFT)
 #define pgd_offset(mm, address)	 ((mm)->pgd + pgd_index(address))
 
-/* Find an entry in the second-level page table.. */
-static inline pmd_t *pmd_offset(pgd_t *dir, unsigned long address)
-{
-	return (pmd_t *) dir;
-}
-
 /* Find an entry in the third-level page table.. */
 #define pte_index(address)		\
 	(((address) >> PAGE_SHIFT) & (PTRS_PER_PTE - 1))