diff --git a/arch/arm64/include/asm/pgalloc.h b/arch/arm64/include/asm/pgalloc.h
index 3c6a7f5988b1..555792921af0 100644
--- a/arch/arm64/include/asm/pgalloc.h
+++ b/arch/arm64/include/asm/pgalloc.h
@@ -83,4 +83,11 @@ pmd_populate(struct mm_struct *mm, pmd_t *pmdp, pgtable_t ptep)
 }
 #define pmd_pgtable(pmd) pmd_page(pmd)
 
+extern void __create_pgd_mapping_extend(pgd_t *pgdir,
+		unsigned int entries_cnt, phys_addr_t phys,
+		unsigned long virt, phys_addr_t size,
+		pgprot_t prot,
+		phys_addr_t (*pgtable_alloc)(int),
+		int flags);
+
 #endif
diff --git a/arch/arm64/kernel/head.S b/arch/arm64/kernel/head.S
index 840bda1869e9..e19649dbbafb 100644
--- a/arch/arm64/kernel/head.S
+++ b/arch/arm64/kernel/head.S
@@ -341,6 +341,9 @@ SYM_FUNC_START_LOCAL(__create_page_tables)
 #if VA_BITS != EXTRA_SHIFT
 #error "Mismatch between VA_BITS and page size/number of translation levels"
 #endif
+	adr_l	x4, idmap_extend_pgtable
+	mov	x5, #1
+	str	x5, [x4]                //require expanded pagetable
 
 	mov	x4, EXTRA_PTRS
 	create_table_entry x0, x3, EXTRA_SHIFT, x4, x5, x6
diff --git a/arch/arm64/mm/mmu.c b/arch/arm64/mm/mmu.c
index 56e4f25e8d6d..30afd6ed275f 100644
--- a/arch/arm64/mm/mmu.c
+++ b/arch/arm64/mm/mmu.c
@@ -145,6 +145,33 @@ static phys_addr_t pgd_pgtable_alloc(int shift)
 
 #include "./mmu_include.c"
 
+int idmap_extend_pgtable;
+
+/* 
+ * todo: tear down part of idmap
+ * todo: lock protection for concurrent population
+ */
+void create_idmap(pgd_t *pgdir, phys_addr_t phys,
+		phys_addr_t size,
+		pgprot_t prot,
+		phys_addr_t (*pgtable_alloc)(int),
+		int flags)
+{
+	u64 ptrs_per_pgd = idmap_ptrs_per_pgd;
+
+#if CONFIG_IDMAP_PGTABLE_EXPAND
+	if (idmap_extend_pgtable)
+		__create_pgd_mapping_extend(pgdir, ptrs_per_pgd,
+				phys, phys, size, prot, pgtable_alloc, flags);
+	else
+		__create_pgd_mapping(pgdir, ptrs_per_pgd,
+				phys, phys, size, prot, pgtable_alloc, flags);
+#else
+	__create_pgd_mapping(pgdir, ptrs_per_pgd,
+			phys, phys, size, prot, pgtable_alloc, flags);
+#endif
+}
+
 /*
  * This function can only be used to modify existing table entries,
  * without allocating new levels of table. Note that this permits the
@@ -158,7 +185,7 @@ static void __init create_mapping_noalloc(phys_addr_t phys, unsigned long virt,
 			&phys, virt);
 		return;
 	}
-	__create_pgd_mapping(init_mm.pgd, phys, virt, size, prot, NULL,
+	__create_pgd_mapping(init_mm.pgd, PTRS_PER_PGD, phys, virt, size, prot, NULL,
 			     NO_CONT_MAPPINGS);
 }
 
@@ -173,7 +200,7 @@ void __init create_pgd_mapping(struct mm_struct *mm, phys_addr_t phys,
 	if (page_mappings_only)
 		flags = NO_BLOCK_MAPPINGS | NO_CONT_MAPPINGS;
 
-	__create_pgd_mapping(mm->pgd, phys, virt, size, prot,
+	__create_pgd_mapping(mm->pgd, PTRS_PER_PGD, phys, virt, size, prot,
 			     pgd_pgtable_alloc, flags);
 }
 
@@ -186,7 +213,7 @@ static void update_mapping_prot(phys_addr_t phys, unsigned long virt,
 		return;
 	}
 
-	__create_pgd_mapping(init_mm.pgd, phys, virt, size, prot, NULL,
+	__create_pgd_mapping(init_mm.pgd, PTRS_PER_PGD, phys, virt, size, prot, NULL,
 			     NO_CONT_MAPPINGS);
 
 	/* flush the TLBs after updating live kernel mappings */
@@ -196,7 +223,7 @@ static void update_mapping_prot(phys_addr_t phys, unsigned long virt,
 static void __init __map_memblock(pgd_t *pgdp, phys_addr_t start,
 				  phys_addr_t end, pgprot_t prot, int flags)
 {
-	__create_pgd_mapping(pgdp, start, __phys_to_virt(start), end - start,
+	__create_pgd_mapping(pgdp, start, PTRS_PER_PGD, __phys_to_virt(start), end - start,
 			     prot, early_pgtable_alloc, flags);
 }
 
@@ -297,7 +324,7 @@ static void __init map_kernel_segment(pgd_t *pgdp, void *va_start, void *va_end,
 	BUG_ON(!PAGE_ALIGNED(pa_start));
 	BUG_ON(!PAGE_ALIGNED(size));
 
-	__create_pgd_mapping(pgdp, pa_start, (unsigned long)va_start, size, prot,
+	__create_pgd_mapping(pgdp, PTRS_PER_PGD, pa_start, (unsigned long)va_start, size, prot,
 			     early_pgtable_alloc, flags);
 
 	if (!(vm_flags & VM_NO_GUARD))
@@ -341,7 +368,7 @@ static int __init map_entry_trampoline(void)
 
 	/* Map only the text into the trampoline page table */
 	memset(tramp_pg_dir, 0, PGD_SIZE);
-	__create_pgd_mapping(tramp_pg_dir, pa_start, TRAMP_VALIAS, PAGE_SIZE,
+	__create_pgd_mapping(tramp_pg_dir, PTRS_PER_PGD, pa_start, TRAMP_VALIAS, PAGE_SIZE,
 			     prot, __pgd_pgtable_alloc, 0);
 
 	/* Map both the text and data into the kernel page table */
@@ -1233,7 +1260,7 @@ int arch_add_memory(int nid, u64 start, u64 size,
 	    IS_ENABLED(CONFIG_KFENCE))
 		flags = NO_BLOCK_MAPPINGS | NO_CONT_MAPPINGS;
 
-	__create_pgd_mapping(swapper_pg_dir, start, __phys_to_virt(start),
+	__create_pgd_mapping(swapper_pg_dir, PTRS_PER_PGD, start, __phys_to_virt(start),
 			     size, params->pgprot, __pgd_pgtable_alloc,
 			     flags);
 
diff --git a/arch/arm64/mm/mmu_include.c b/arch/arm64/mm/mmu_include.c
index e9ebdffe860b..1cf5af7e2aeb 100644
--- a/arch/arm64/mm/mmu_include.c
+++ b/arch/arm64/mm/mmu_include.c
@@ -233,14 +233,20 @@ static void alloc_init_pud(pgd_t *pgdp, unsigned long addr, unsigned long end,
 	pud_clear_fixmap();
 }
 
-static void __create_pgd_mapping(pgd_t *pgdir, phys_addr_t phys,
+static void __create_pgd_mapping(pgd_t *pgdir, unsigned int entries_cnt, phys_addr_t phys,
 				 unsigned long virt, phys_addr_t size,
 				 pgprot_t prot,
 				 phys_addr_t (*pgtable_alloc)(int),
 				 int flags)
 {
 	unsigned long addr, end, next;
-	pgd_t *pgdp = pgd_offset_pgd(pgdir, virt);
+	pgd_t *pgdp;
+
+	if (likely(entries_cnt == PTRS_PER_PGD))
+		pgdp = pgd_offset_pgd(pgdir, virt);
+	else {
+		pgdp = pgdir + ((virt >> PGDIR_SHIFT) & (entries_cnt - 1));
+	}
 
 	/*
 	 * If the virtual and physical address don't have the same offset
