diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
index 9a28cbe..adbb8ea 100644
--- a/arch/arm64/Kconfig
+++ b/arch/arm64/Kconfig
@@ -182,12 +182,17 @@ config ARM64_VA_BITS_42
 	bool "42-bit"
 	depends on ARM64_64K_PAGES
 
+config ARM64_VA_BITS_48
+	bool "48-bit"
+	depends on ARM64_4K_PAGES
+
 endchoice
 
 config ARM64_VA_BITS
 	int
 	default 39 if ARM64_VA_BITS_39
 	default 42 if ARM64_VA_BITS_42
+	default 48 if ARM64_VA_BITS_48
 
 config ARM64_2_LEVELS
 	def_bool y if ARM64_64K_PAGES && ARM64_VA_BITS_42
@@ -195,6 +200,9 @@ config ARM64_2_LEVELS
 config ARM64_3_LEVELS
 	def_bool y if ARM64_4K_PAGES && ARM64_VA_BITS_39
 
+config ARM64_4_LEVELS
+	def_bool y if ARM64_4K_PAGES && ARM64_VA_BITS_48
+
 config CPU_BIG_ENDIAN
        bool "Build big-endian kernel"
        help
diff --git a/arch/arm64/include/asm/memblock.h b/arch/arm64/include/asm/memblock.h
index 6afeed2..e4ac8bf 100644
--- a/arch/arm64/include/asm/memblock.h
+++ b/arch/arm64/include/asm/memblock.h
@@ -16,6 +16,12 @@
 #ifndef __ASM_MEMBLOCK_H
 #define __ASM_MEMBLOCK_H
 
+#ifndef CONFIG_ARM64_4_LEVELS
+#define MEMBLOCK_INITIAL_LIMIT	PGDIR_SIZE
+#else
+#define MEMBLOCK_INITIAL_LIMIT	PUD_SIZE
+#endif
+
 extern void arm64_memblock_init(void);
 
 #endif
diff --git a/arch/arm64/include/asm/page.h b/arch/arm64/include/asm/page.h
index 268e53d..83b5289 100644
--- a/arch/arm64/include/asm/page.h
+++ b/arch/arm64/include/asm/page.h
@@ -35,8 +35,10 @@
 
 #ifdef CONFIG_ARM64_2_LEVELS
 #include <asm/pgtable-2level-types.h>
-#else
+#elif defined(CONFIG_ARM64_3_LEVELS)
 #include <asm/pgtable-3level-types.h>
+#else
+#include <asm/pgtable-4level-types.h>
 #endif
 
 extern void __cpu_clear_user_page(void *p, unsigned long user);
diff --git a/arch/arm64/include/asm/pgalloc.h b/arch/arm64/include/asm/pgalloc.h
index 4829837..8d745fa 100644
--- a/arch/arm64/include/asm/pgalloc.h
+++ b/arch/arm64/include/asm/pgalloc.h
@@ -26,6 +26,26 @@
 
 #define check_pgt_cache()		do { } while (0)
 
+#ifdef CONFIG_ARM64_4_LEVELS
+
+static inline pud_t *pud_alloc_one(struct mm_struct *mm, unsigned long addr)
+{
+	return (pud_t *)get_zeroed_page(GFP_KERNEL | __GFP_REPEAT);
+}
+
+static inline void pud_free(struct mm_struct *mm, pud_t *pud)
+{
+	BUG_ON((unsigned long)pud & (PAGE_SIZE-1));
+	free_page((unsigned long)pud);
+}
+
+static inline void pgd_populate(struct mm_struct *mm, pgd_t *pgd, pud_t *pud)
+{
+	set_pgd(pgd, __pgd(__pa(pud) | PUD_TYPE_TABLE));
+}
+
+#endif  /* CONFIG_ARM64_4_LEVELS */
+
 #ifndef CONFIG_ARM64_2_LEVELS
 
 static inline pmd_t *pmd_alloc_one(struct mm_struct *mm, unsigned long addr)
diff --git a/arch/arm64/include/asm/pgtable-hwdef.h b/arch/arm64/include/asm/pgtable-hwdef.h
index c7c603b..fddcc3e 100644
--- a/arch/arm64/include/asm/pgtable-hwdef.h
+++ b/arch/arm64/include/asm/pgtable-hwdef.h
@@ -18,8 +18,10 @@
 
 #ifdef CONFIG_ARM64_2_LEVELS
 #include <asm/pgtable-2level-hwdef.h>
-#else
+#elif defined(CONFIG_ARM64_3_LEVELS)
 #include <asm/pgtable-3level-hwdef.h>
+#else
+#include <asm/pgtable-4level-hwdef.h>
 #endif
 
 /*
@@ -27,7 +29,7 @@
  *
  * Level 1 descriptor (PUD).
  */
-
+#define PUD_TYPE_TABLE		(_AT(pudval_t, 3) << 0)
 #define PUD_TABLE_BIT		(_AT(pgdval_t, 1) << 1)
 #define PUD_TYPE_MASK		(_AT(pgdval_t, 3) << 0)
 #define PUD_TYPE_SECT		(_AT(pgdval_t, 1) << 0)
diff --git a/arch/arm64/include/asm/pgtable.h b/arch/arm64/include/asm/pgtable.h
index 4a350af..4dafa5c 100644
--- a/arch/arm64/include/asm/pgtable.h
+++ b/arch/arm64/include/asm/pgtable.h
@@ -35,7 +35,11 @@
  * VMALLOC and SPARSEMEM_VMEMMAP ranges.
  */
 #define VMALLOC_START		(UL(0xffffffffffffffff) << VA_BITS)
+#ifndef CONFIG_ARM64_4_LEVELS
 #define VMALLOC_END		(PAGE_OFFSET - UL(0x400000000) - SZ_64K)
+#else
+#define VMALLOC_END		(PAGE_OFFSET - UL(0x40000000000) - SZ_64K)
+#endif
 
 #define vmemmap			((struct page *)(VMALLOC_END + SZ_64K))
 
@@ -44,12 +48,16 @@
 #ifndef __ASSEMBLY__
 extern void __pte_error(const char *file, int line, unsigned long val);
 extern void __pmd_error(const char *file, int line, unsigned long val);
+extern void __pud_error(const char *file, int line, unsigned long val);
 extern void __pgd_error(const char *file, int line, unsigned long val);
 
 #define pte_ERROR(pte)		__pte_error(__FILE__, __LINE__, pte_val(pte))
 #ifndef CONFIG_ARM64_2_LEVELS
 #define pmd_ERROR(pmd)		__pmd_error(__FILE__, __LINE__, pmd_val(pmd))
 #endif
+#ifdef CONFIG_ARM64_4_LEVELS
+#define pud_ERROR(pud)		__pud_error(__FILE__, __LINE__, pud_val(pud))
+#endif
 #define pgd_ERROR(pgd)		__pgd_error(__FILE__, __LINE__, pgd_val(pgd))
 
 #ifdef CONFIG_SMP
@@ -348,6 +356,30 @@ static inline pmd_t *pud_page_vaddr(pud_t pud)
 
 #endif	/* CONFIG_ARM64_2_LEVELS */
 
+#ifdef CONFIG_ARM64_4_LEVELS
+
+#define pgd_none(pgd)		(!pgd_val(pgd))
+#define pgd_bad(pgd)		(!(pgd_val(pgd) & 2))
+#define pgd_present(pgd)	(pgd_val(pgd))
+
+static inline void set_pgd(pgd_t *pgdp, pgd_t pgd)
+{
+	*pgdp = pgd;
+	dsb(ishst);
+}
+
+static inline void pgd_clear(pgd_t *pgdp)
+{
+	set_pgd(pgdp, __pgd(0));
+}
+
+static inline pud_t *pgd_page_vaddr(pgd_t pgd)
+{
+	return __va(pgd_val(pgd) & PHYS_MASK & (s32)PAGE_MASK);
+}
+
+#endif  /* CONFIG_ARM64_4_LEVELS */
+
 /* to find an entry in a page-table-directory */
 #define pgd_index(addr)		(((addr) >> PGDIR_SHIFT) & (PTRS_PER_PGD - 1))
 
@@ -356,6 +388,14 @@ static inline pmd_t *pud_page_vaddr(pud_t pud)
 /* to find an entry in a kernel page-table-directory */
 #define pgd_offset_k(addr)	pgd_offset(&init_mm, addr)
 
+#ifdef CONFIG_ARM64_4_LEVELS
+#define pud_index(addr)		(((addr) >> PUD_SHIFT) & (PTRS_PER_PUD - 1))
+static inline pud_t *pud_offset(pgd_t *pgd, unsigned long addr)
+{
+	return (pud_t *)pgd_page_vaddr(*pgd) + pud_index(addr);
+}
+#endif
+
 /* Find an entry in the second-level page table.. */
 #ifndef CONFIG_ARM64_2_LEVELS
 #define pmd_index(addr)		(((addr) >> PMD_SHIFT) & (PTRS_PER_PMD - 1))
@@ -384,8 +424,13 @@ static inline pmd_t pmd_modify(pmd_t pmd, pgprot_t newprot)
 extern pgd_t swapper_pg_dir[PTRS_PER_PGD];
 extern pgd_t idmap_pg_dir[PTRS_PER_PGD];
 
+#ifdef CONFIG_ARM64_4_LEVELS
+#define SWAPPER_DIR_SIZE	(4 * PAGE_SIZE)
+#define IDMAP_DIR_SIZE		(3 * PAGE_SIZE)
+#else
 #define SWAPPER_DIR_SIZE	(3 * PAGE_SIZE)
 #define IDMAP_DIR_SIZE		(2 * PAGE_SIZE)
+#endif
 
 /*
  * Encode and decode a swap entry:
diff --git a/arch/arm64/include/asm/tlb.h b/arch/arm64/include/asm/tlb.h
index bc19101..49dc8f0 100644
--- a/arch/arm64/include/asm/tlb.h
+++ b/arch/arm64/include/asm/tlb.h
@@ -100,6 +100,15 @@ static inline void __pmd_free_tlb(struct mmu_gather *tlb, pmd_t *pmdp,
 }
 #endif
 
+#ifdef CONFIG_ARM64_4_LEVELS
+static inline void __pud_free_tlb(struct mmu_gather *tlb, pud_t *pudp,
+				  unsigned long addr)
+{
+	tlb_add_flush(tlb, addr);
+	tlb_remove_page(tlb, virt_to_page(pudp));
+}
+#endif
+
 static inline void __tlb_remove_pmd_tlb_entry(struct mmu_gather *tlb, pmd_t *pmdp,
 						unsigned long address)
 {
diff --git a/arch/arm64/kernel/head.S b/arch/arm64/kernel/head.S
index b96a732..8464087 100644
--- a/arch/arm64/kernel/head.S
+++ b/arch/arm64/kernel/head.S
@@ -37,8 +37,9 @@
 
 /*
  * swapper_pg_dir is the virtual address of the initial page table. We place
- * the page tables 3 * PAGE_SIZE below KERNEL_RAM_VADDR. The idmap_pg_dir has
- * 2 pages and is placed below swapper_pg_dir.
+ * the page tables 3 * PAGE_SIZE (2 or 3 levels) or 4 * PAGE_SIZE (4 levels)
+ * below KERNEL_RAM_VADDR. The idmap_pg_dir has 2 pages (2 or 3 levels) or
+ * 3 pages (4 levels) and is placed below swapper_pg_dir.
  */
 #define KERNEL_RAM_VADDR	(PAGE_OFFSET + TEXT_OFFSET)
 
@@ -46,8 +47,13 @@
 #error KERNEL_RAM_VADDR must start at 0xXXX80000
 #endif
 
+#ifdef CONFIG_ARM64_4_LEVELS
+#define SWAPPER_DIR_SIZE	(4 * PAGE_SIZE)
+#define IDMAP_DIR_SIZE		(3 * PAGE_SIZE)
+#else
 #define SWAPPER_DIR_SIZE	(3 * PAGE_SIZE)
 #define IDMAP_DIR_SIZE		(2 * PAGE_SIZE)
+#endif
 
 	.globl	swapper_pg_dir
 	.equ	swapper_pg_dir, KERNEL_RAM_VADDR - SWAPPER_DIR_SIZE
@@ -368,16 +374,42 @@ ENDPROC(__calc_phys_offset)
 	.quad	PAGE_OFFSET
 
 /*
- * Macro to populate the PGD for the corresponding block entry in the next
- * level (tbl) for the given virtual address.
+ * Macro to populate the PUD for the corresponding block entry in the next
+ * level (tbl) for the given virtual address in case of 4 levels.
+ *
+ * Preserves:	pgd, virt
+ * Corrupts:	tbl, tmp1, tmp2
+ * Returns:	pud
+ */
+	.macro	create_pud_entry, pgd, tbl, virt, pud, tmp1, tmp2
+#ifdef CONFIG_ARM64_4_LEVELS
+	add	\tbl, \tbl, #PAGE_SIZE		// bump tbl 1 page up.
+						// to make room for pud
+	add	\pud, \pgd, #PAGE_SIZE		// pgd points to pud which
+						// follows pgd
+	lsr	\tmp1, \virt, #PUD_SHIFT
+	and	\tmp1, \tmp1, #PTRS_PER_PUD - 1	// PUD index
+	orr	\tmp2, \tbl, #3			// PUD entry table type
+	str	\tmp2, [\pud, \tmp1, lsl #3]
+#else
+	mov	\pud, \tbl
+#endif
+	.endm
+
+/*
+ * Macro to populate the PGD (and possibily PUD) for the corresponding
+ * block entry in the next level (tbl) for the given virtual address.
  *
- * Preserves:	pgd, tbl, virt
- * Corrupts:	tmp1, tmp2
+ * Preserves:	pgd, virt
+ * Corrupts:	tmp1, tmp2, tmp3
+ * Returns:	tbl -> page where block mappings can be placed
+ *	(changed to make room for pud with 4 levels, preserved otherwise)
  */
-	.macro	create_pgd_entry, pgd, tbl, virt, tmp1, tmp2
+	.macro	create_pgd_entry, pgd, tbl, virt, tmp1, tmp2, tmp3
+	create_pud_entry \pgd, \tbl, \virt, \tmp3, \tmp1, \tmp2
 	lsr	\tmp1, \virt, #PGDIR_SHIFT
 	and	\tmp1, \tmp1, #PTRS_PER_PGD - 1	// PGD index
-	orr	\tmp2, \tbl, #3			// PGD entry table type
+	orr	\tmp2, \tmp3, #3		// PGD entry table type
 	str	\tmp2, [\pgd, \tmp1, lsl #3]
 	.endm
 
@@ -442,7 +474,7 @@ __create_page_tables:
 	add	x0, x25, #PAGE_SIZE		// section table address
 	ldr	x3, =KERNEL_START
 	add	x3, x3, x28			// __pa(KERNEL_START)
-	create_pgd_entry x25, x0, x3, x5, x6
+	create_pgd_entry x25, x0, x3, x1, x5, x6
 	ldr	x6, =KERNEL_END
 	mov	x5, x3				// __pa(KERNEL_START)
 	add	x6, x6, x28			// __pa(KERNEL_END)
@@ -453,7 +485,7 @@ __create_page_tables:
 	 */
 	add	x0, x26, #PAGE_SIZE		// section table address
 	mov	x5, #PAGE_OFFSET
-	create_pgd_entry x26, x0, x5, x3, x6
+	create_pgd_entry x26, x0, x5, x1, x3, x6
 	ldr	x6, =KERNEL_END
 	mov	x3, x24				// phys offset
 	create_block_map x0, x7, x3, x5, x6
@@ -479,7 +511,7 @@ __create_page_tables:
 	 */
 	ldr	x5, =FIXADDR_TOP		// Fixed mapping virtual address
 	add	x0, x26, #2 * PAGE_SIZE		// section table address
-	create_pgd_entry x26, x0, x5, x6, x7
+	create_pgd_entry x26, x0, x5, x1, x6, x7
 
 	/*
 	 * Since the page tables have been populated with non-cacheable
diff --git a/arch/arm64/kernel/traps.c b/arch/arm64/kernel/traps.c
index 506f781..02cd3f0 100644
--- a/arch/arm64/kernel/traps.c
+++ b/arch/arm64/kernel/traps.c
@@ -339,6 +339,11 @@ void __pmd_error(const char *file, int line, unsigned long val)
 	pr_crit("%s:%d: bad pmd %016lx.\n", file, line, val);
 }
 
+void __pud_error(const char *file, int line, unsigned long val)
+{
+	pr_crit("%s:%d: bad pud %016lx.\n", file, line, val);
+}
+
 void __pgd_error(const char *file, int line, unsigned long val)
 {
 	pr_crit("%s:%d: bad pgd %016lx.\n", file, line, val);
diff --git a/arch/arm64/mm/fault.c b/arch/arm64/mm/fault.c
index 89c6763..663397b 100644
--- a/arch/arm64/mm/fault.c
+++ b/arch/arm64/mm/fault.c
@@ -62,6 +62,7 @@ void show_pte(struct mm_struct *mm, unsigned long addr)
 			break;
 
 		pud = pud_offset(pgd, addr);
+		printk(", *pud=%016llx", pud_val(*pud));
 		if (pud_none(*pud) || pud_bad(*pud))
 			break;
 
diff --git a/arch/arm64/mm/mmu.c b/arch/arm64/mm/mmu.c
index 3a729de..ce09ed3 100644
--- a/arch/arm64/mm/mmu.c
+++ b/arch/arm64/mm/mmu.c
@@ -32,6 +32,7 @@
 #include <asm/setup.h>
 #include <asm/sizes.h>
 #include <asm/tlb.h>
+#include <asm/memblock.h>
 #include <asm/mmu_context.h>
 
 #include "mm.h"
@@ -190,9 +191,15 @@ static void __init alloc_init_pmd(pud_t *pud, unsigned long addr,
 static void __init alloc_init_pud(pgd_t *pgd, unsigned long addr,
 				  unsigned long end, unsigned long phys)
 {
-	pud_t *pud = pud_offset(pgd, addr);
+	pud_t *pud;
 	unsigned long next;
 
+	if (pgd_none(*pgd) || pgd_bad(*pgd)) {
+		pud = early_alloc(PTRS_PER_PUD * sizeof(pud_t));
+		pgd_populate(&init_mm, pgd, pud);
+	}
+
+	pud = pud_offset(pgd, addr);
 	do {
 		next = pud_addr_end(addr, end);
 
@@ -262,10 +269,11 @@ static void __init map_mem(void)
 	 * memory addressable from the initial direct kernel mapping.
 	 *
 	 * The initial direct kernel mapping, located at swapper_pg_dir,
-	 * gives us PGDIR_SIZE memory starting from PHYS_OFFSET (which must be
-	 * aligned to 2MB as per Documentation/arm64/booting.txt).
+	 * gives us PGDIR_SIZE (2 and 3 levels) or PUD_SIZE (4 levels) memory
+	 * starting from PHYS_OFFSET (which must be aligned to 2MB as per
+	 * Documentation/arm64/booting.txt).
 	 */
-	limit = PHYS_OFFSET + PGDIR_SIZE;
+	limit = PHYS_OFFSET + MEMBLOCK_INITIAL_LIMIT;
 	memblock_set_current_limit(limit);
 
 	/* map all the memory banks */
