1 files changed, 41 insertions, 7 deletions

diff --git a/arch/arm64/include/asm/pgtable.h b/arch/arm64/include/asm/pgtable.h
index 1bdeca8918a6..50b1ef8584c0 100644
--- a/arch/arm64/include/asm/pgtable.h
+++ b/arch/arm64/include/asm/pgtable.h
@@ -360,6 +360,7 @@ static inline int pmd_protnone(pmd_t pmd)
 #define pmd_present(pmd)	pte_present(pmd_pte(pmd))
 #define pmd_dirty(pmd)		pte_dirty(pmd_pte(pmd))
 #define pmd_young(pmd)		pte_young(pmd_pte(pmd))
+#define pmd_valid(pmd)		pte_valid(pmd_pte(pmd))
 #define pmd_wrprotect(pmd)	pte_pmd(pte_wrprotect(pmd_pte(pmd)))
 #define pmd_mkold(pmd)		pte_pmd(pte_mkold(pmd_pte(pmd)))
 #define pmd_mkwrite(pmd)	pte_pmd(pte_mkwrite(pmd_pte(pmd)))
@@ -428,10 +429,33 @@ extern pgprot_t phys_mem_access_prot(struct file *file, unsigned long pfn,
 				 PUD_TYPE_TABLE)
 #endif
 
+extern pgd_t init_pg_dir[PTRS_PER_PGD];
+extern pgd_t init_pg_end[];
+extern pgd_t swapper_pg_dir[PTRS_PER_PGD];
+extern pgd_t idmap_pg_dir[PTRS_PER_PGD];
+extern pgd_t tramp_pg_dir[PTRS_PER_PGD];
+
+extern void set_swapper_pgd(pgd_t *pgdp, pgd_t pgd);
+
+static inline bool in_swapper_pgdir(void *addr)
+{
+	return ((unsigned long)addr & PAGE_MASK) ==
+	        ((unsigned long)swapper_pg_dir & PAGE_MASK);
+}
+
 static inline void set_pmd(pmd_t *pmdp, pmd_t pmd)
 {
+#ifdef __PAGETABLE_PMD_FOLDED
+	if (in_swapper_pgdir(pmdp)) {
+		set_swapper_pgd((pgd_t *)pmdp, __pgd(pmd_val(pmd)));
+		return;
+	}
+#endif /* __PAGETABLE_PMD_FOLDED */
+
 	WRITE_ONCE(*pmdp, pmd);
-	dsb(ishst);
+
+	if (pmd_valid(pmd))
+		dsb(ishst);
 }
 
 static inline void pmd_clear(pmd_t *pmdp)
@@ -477,11 +501,21 @@ static inline phys_addr_t pmd_page_paddr(pmd_t pmd)
 #define pud_none(pud)		(!pud_val(pud))
 #define pud_bad(pud)		(!(pud_val(pud) & PUD_TABLE_BIT))
 #define pud_present(pud)	pte_present(pud_pte(pud))
+#define pud_valid(pud)		pte_valid(pud_pte(pud))
 
 static inline void set_pud(pud_t *pudp, pud_t pud)
 {
+#ifdef __PAGETABLE_PUD_FOLDED
+	if (in_swapper_pgdir(pudp)) {
+		set_swapper_pgd((pgd_t *)pudp, __pgd(pud_val(pud)));
+		return;
+	}
+#endif /* __PAGETABLE_PUD_FOLDED */
+
 	WRITE_ONCE(*pudp, pud);
-	dsb(ishst);
+
+	if (pud_valid(pud))
+		dsb(ishst);
 }
 
 static inline void pud_clear(pud_t *pudp)
@@ -532,6 +566,11 @@ static inline phys_addr_t pud_page_paddr(pud_t pud)
 
 static inline void set_pgd(pgd_t *pgdp, pgd_t pgd)
 {
+	if (in_swapper_pgdir(pgdp)) {
+		set_swapper_pgd(pgdp, pgd);
+		return;
+	}
+
 	WRITE_ONCE(*pgdp, pgd);
 	dsb(ishst);
 }
@@ -712,11 +751,6 @@ static inline pmd_t pmdp_establish(struct vm_area_struct *vma,
 }
 #endif
 
-extern pgd_t swapper_pg_dir[PTRS_PER_PGD];
-extern pgd_t swapper_pg_end[];
-extern pgd_t idmap_pg_dir[PTRS_PER_PGD];
-extern pgd_t tramp_pg_dir[PTRS_PER_PGD];
-
 /*
  * Encode and decode a swap entry:
  *	bits 0-1:	present (must be zero)