diff options
Diffstat (limited to 'arch/arm64/mm/mmu.c')
| -rw-r--r-- | arch/arm64/mm/mmu.c | 29 |
1 files changed, 29 insertions, 0 deletions
diff --git a/arch/arm64/mm/mmu.c b/arch/arm64/mm/mmu.c index b5dc5f9c77f6..7f04dc4f0d8d 100644 --- a/arch/arm64/mm/mmu.c +++ b/arch/arm64/mm/mmu.c @@ -349,6 +349,19 @@ static void __init map_mem(void) { struct memblock_region *reg; struct map_desc md; + phys_addr_t limit; + + /* + * Temporarily limit the memblock range. We need to do this as + * create_mapping requires puds, pmds and ptes to be allocated from + * 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). + */ + limit = PHYS_OFFSET + PGDIR_SIZE; + memblock_set_current_limit(limit); /* map all the memory banks */ for_each_memblock(memory, reg) { @@ -363,6 +376,22 @@ 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(&md); } } |