1 files changed, 21 insertions, 2 deletions

diff --git a/arch/arm64/mm/mmu.c b/arch/arm64/mm/mmu.c
index a8d1059b91b2..f557ebbe7013 100644
--- a/arch/arm64/mm/mmu.c
+++ b/arch/arm64/mm/mmu.c
@@ -296,6 +296,7 @@ void __iomem * __init early_io_map(phys_addr_t phys, unsigned long virt)
 static void __init map_mem(void)
 {
         struct memblock_region *reg;
+        phys_addr_t limit;
 
         /*
          * Temporarily limit the memblock range. We need to do this as
@@ -303,9 +304,11 @@ 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 (aligned).
+         * gives us PGDIR_SIZE memory starting from PHYS_OFFSET (which must be
+         * aligned to 2MB as per Documentation/arm64/booting.txt).
          */
-        memblock_set_current_limit((PHYS_OFFSET & PGDIR_MASK) + PGDIR_SIZE);
+        limit = PHYS_OFFSET + PGDIR_SIZE;
+        memblock_set_current_limit(limit);
 
         /* map all the memory banks */
         for_each_memblock(memory, reg) {
@@ -315,6 +318,22 @@ static void __init map_mem(void)
                 if (start >= end)
                         break;
 
+#ifndef CONFIG_ARM64_64K_PAGES
+                /*
+                 * For the first memory bank align the start address and
+                 * current memblock limit to prevent create_mapping() from
+                 * allocating pte page tables from unmapped memory.
+                 * When 64K pages are enabled, the pte page table for the
+                 * first PGDIR_SIZE is already present in swapper_pg_dir.
+                 */
+                if (start < limit)
+                        start = ALIGN(start, PMD_SIZE);
+                if (end < limit) {
+                        limit = end & PMD_MASK;
+                        memblock_set_current_limit(limit);
+                }
+#endif
+
                 create_mapping(start, __phys_to_virt(start), end - start);
         }