Subject: [PATCH v4 14/14] mm: remove __ARCH_HAS_5LEVEL_HACK and include/asm-generic/5level-fixup.h

From: Mike Rapoport <[email-masked]>
Date: Tue, 14 Apr 2020 18:34:55 +0300

From: Mike Rapoport <[email-masked]>

There are no architectures that use include/asm-generic/5level-fixup.h
therefore it can be removed along with __ARCH_HAS_5LEVEL_HACK define and
the code it surrounds

Signed-off-by: Mike Rapoport <[email-masked]>
---
 include/asm-generic/5level-fixup.h | 58 ------------------------------
 include/linux/mm.h                 |  6 ----
 mm/kasan/init.c                    | 11 ------
 mm/memory.c                        |  8 -----
 4 files changed, 83 deletions(-)
 delete mode 100644 include/asm-generic/5level-fixup.h

diff --git a/include/asm-generic/5level-fixup.h b/include/asm-generic/5level-fixup.h
deleted file mode 100644
index 4c74b1c1d13b..000000000000
--- a/include/asm-generic/5level-fixup.h
+++ /dev/null
@@ -1,58 +0,0 @@
-/* SPDX-License-Identifier: GPL-2.0 */
-#ifndef _5LEVEL_FIXUP_H
-#define _5LEVEL_FIXUP_H
-
-#define __ARCH_HAS_5LEVEL_HACK
-#define __PAGETABLE_P4D_FOLDED 1
-
-#define P4D_SHIFT			PGDIR_SHIFT
-#define P4D_SIZE			PGDIR_SIZE
-#define P4D_MASK			PGDIR_MASK
-#define MAX_PTRS_PER_P4D		1
-#define PTRS_PER_P4D			1
-
-#define p4d_t				pgd_t
-
-#define pud_alloc(mm, p4d, address) \
-	((unlikely(pgd_none(*(p4d))) && __pud_alloc(mm, p4d, address)) ? \
-		NULL : pud_offset(p4d, address))
-
-#define p4d_alloc(mm, pgd, address)	(pgd)
-#define p4d_offset(pgd, start)		(pgd)
-
-#ifndef __ASSEMBLY__
-static inline int p4d_none(p4d_t p4d)
-{
-	return 0;
-}
-
-static inline int p4d_bad(p4d_t p4d)
-{
-	return 0;
-}
-
-static inline int p4d_present(p4d_t p4d)
-{
-	return 1;
-}
-#endif
-
-#define p4d_ERROR(p4d)			do { } while (0)
-#define p4d_clear(p4d)			pgd_clear(p4d)
-#define p4d_val(p4d)			pgd_val(p4d)
-#define p4d_populate(mm, p4d, pud)	pgd_populate(mm, p4d, pud)
-#define p4d_populate_safe(mm, p4d, pud)	pgd_populate(mm, p4d, pud)
-#define p4d_page(p4d)			pgd_page(p4d)
-#define p4d_page_vaddr(p4d)		pgd_page_vaddr(p4d)
-
-#define __p4d(x)			__pgd(x)
-#define set_p4d(p4dp, p4d)		set_pgd(p4dp, p4d)
-
-#undef p4d_free_tlb
-#define p4d_free_tlb(tlb, x, addr)	do { } while (0)
-#define p4d_free(mm, x)			do { } while (0)
-
-#undef  p4d_addr_end
-#define p4d_addr_end(addr, end)		(end)
-
-#endif
diff --git a/include/linux/mm.h b/include/linux/mm.h
index 5a323422d783..f794b77df1ca 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -2060,11 +2060,6 @@ int __pte_alloc_kernel(pmd_t *pmd);
 
 #if defined(CONFIG_MMU)
 
-/*
- * The following ifdef needed to get the 5level-fixup.h header to work.
- * Remove it when 5level-fixup.h has been removed.
- */
-#ifndef __ARCH_HAS_5LEVEL_HACK
 static inline p4d_t *p4d_alloc(struct mm_struct *mm, pgd_t *pgd,
 		unsigned long address)
 {
@@ -2078,7 +2073,6 @@ static inline pud_t *pud_alloc(struct mm_struct *mm, p4d_t *p4d,
 	return (unlikely(p4d_none(*p4d)) && __pud_alloc(mm, p4d, address)) ?
 		NULL : pud_offset(p4d, address);
 }
-#endif /* !__ARCH_HAS_5LEVEL_HACK */
 
 static inline pmd_t *pmd_alloc(struct mm_struct *mm, pud_t *pud, unsigned long address)
 {
diff --git a/mm/kasan/init.c b/mm/kasan/init.c
index ce45c491ebcd..fe6be0be1f76 100644
--- a/mm/kasan/init.c
+++ b/mm/kasan/init.c
@@ -250,20 +250,9 @@ int __ref kasan_populate_early_shadow(const void *shadow_start,
 			 * 3,2 - level page tables where we don't have
 			 * puds,pmds, so pgd_populate(), pud_populate()
 			 * is noops.
-			 *
-			 * The ifndef is required to avoid build breakage.
-			 *
-			 * With 5level-fixup.h, pgd_populate() is not nop and
-			 * we reference kasan_early_shadow_p4d. It's not defined
-			 * unless 5-level paging enabled.
-			 *
-			 * The ifndef can be dropped once all KASAN-enabled
-			 * architectures will switch to pgtable-nop4d.h.
 			 */
-#ifndef __ARCH_HAS_5LEVEL_HACK
 			pgd_populate(&init_mm, pgd,
 					lm_alias(kasan_early_shadow_p4d));
-#endif
 			p4d = p4d_offset(pgd, addr);
 			p4d_populate(&init_mm, p4d,
 					lm_alias(kasan_early_shadow_pud));
diff --git a/mm/memory.c b/mm/memory.c
index f703fe8c8346..379277c631b4 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -4434,19 +4434,11 @@ int __pud_alloc(struct mm_struct *mm, p4d_t *p4d, unsigned long address)
 	smp_wmb(); /* See comment in __pte_alloc */
 
 	spin_lock(&mm->page_table_lock);
-#ifndef __ARCH_HAS_5LEVEL_HACK
 	if (!p4d_present(*p4d)) {
 		mm_inc_nr_puds(mm);
 		p4d_populate(mm, p4d, new);
 	} else	/* Another has populated it */
 		pud_free(mm, new);
-#else
-	if (!pgd_present(*p4d)) {
-		mm_inc_nr_puds(mm);
-		pgd_populate(mm, p4d, new);
-	} else	/* Another has populated it */
-		pud_free(mm, new);
-#endif /* __ARCH_HAS_5LEVEL_HACK */
 	spin_unlock(&mm->page_table_lock);
 	return 0;
 }
-- 
2.25.1