mm: remove __ARCH_HAS_4LEVEL_HACK and include/asm-generic/4level-fixup.h

There are no architectures that use include/asm-generic/4level-fixup.h
therefore it can be removed along with __ARCH_HAS_4LEVEL_HACK define.

Link: http://lkml.kernel.org/r/1572938135-31886-14-git-send-email-rppt@kernel.orgSigned-off-by: NMike 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: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

include/asm-generic/4level-fixup.h

-/* SPDX-License-Identifier: GPL-2.0 */
-#ifndef _4LEVEL_FIXUP_H
-#define _4LEVEL_FIXUP_H
-
-#define __ARCH_HAS_4LEVEL_HACK
-#define __PAGETABLE_PUD_FOLDED 1
-
-#define PUD_SHIFT			PGDIR_SHIFT
-#define PUD_SIZE			PGDIR_SIZE
-#define PUD_MASK			PGDIR_MASK
-#define PTRS_PER_PUD			1
-
-#define pud_t				pgd_t
-
-#define pmd_alloc(mm, pud, address) \
-	((unlikely(pgd_none(*(pud))) && __pmd_alloc(mm, pud, address))? \
- 		NULL: pmd_offset(pud, address))
-
-#define pud_offset(pgd, start)		(pgd)
-#define pud_none(pud)			0
-#define pud_bad(pud)			0
-#define pud_present(pud)		1
-#define pud_ERROR(pud)			do { } while (0)
-#define pud_clear(pud)			pgd_clear(pud)
-#define pud_val(pud)			pgd_val(pud)
-#define pud_populate(mm, pud, pmd)	pgd_populate(mm, pud, pmd)
-#define pud_page(pud)			pgd_page(pud)
-#define pud_page_vaddr(pud)		pgd_page_vaddr(pud)
-
-#undef pud_free_tlb
-#define pud_free_tlb(tlb, x, addr)	do { } while (0)
-#define pud_free(mm, x)			do { } while (0)
-
-#undef  pud_addr_end
-#define pud_addr_end(addr, end)		(end)
-
-#include <asm-generic/5level-fixup.h>
-
-#endif

include/linux/mm.h

@@ -1838,12 +1838,12 @@ static inline void mm_dec_nr_ptes(struct mm_struct *mm) {}
 int __pte_alloc(struct mm_struct *mm, pmd_t *pmd);
 int __pte_alloc_kernel(pmd_t *pmd);
 
+#if defined(CONFIG_MMU)
+
 /*
- * The following ifdef needed to get the 4level-fixup.h header to work.
- * Remove it when 4level-fixup.h has been removed.
+ * The following ifdef needed to get the 5level-fixup.h header to work.
+ * Remove it when 5level-fixup.h has been removed.
  */
-#if defined(CONFIG_MMU) && !defined(__ARCH_HAS_4LEVEL_HACK)
-
 #ifndef __ARCH_HAS_5LEVEL_HACK
 static inline p4d_t *p4d_alloc(struct mm_struct *mm, pgd_t *pgd,
 		unsigned long address)
@@ -1865,7 +1865,7 @@ static inline pmd_t *pmd_alloc(struct mm_struct *mm, pud_t *pud, unsigned long a
 	return (unlikely(pud_none(*pud)) && __pmd_alloc(mm, pud, address))?
 		NULL: pmd_offset(pud, address);
 }
-#endif /* CONFIG_MMU && !__ARCH_HAS_4LEVEL_HACK */
+#endif /* CONFIG_MMU */
 
 #if USE_SPLIT_PTE_PTLOCKS
 #if ALLOC_SPLIT_PTLOCKS

mm/memory.c

@@ -4197,19 +4197,11 @@ int __pmd_alloc(struct mm_struct *mm, pud_t *pud, unsigned long address)
 	smp_wmb(); /* See comment in __pte_alloc */
 
 	ptl = pud_lock(mm, pud);
-#ifndef __ARCH_HAS_4LEVEL_HACK
 	if (!pud_present(*pud)) {
 		mm_inc_nr_pmds(mm);
 		pud_populate(mm, pud, new);
 	} else	/* Another has populated it */
 		pmd_free(mm, new);
-#else
-	if (!pgd_present(*pud)) {
-		mm_inc_nr_pmds(mm);
-		pgd_populate(mm, pud, new);
-	} else /* Another has populated it */
-		pmd_free(mm, new);
-#endif /* __ARCH_HAS_4LEVEL_HACK */
 	spin_unlock(ptl);
 	return 0;
 }