[RFC PATCH v2 06/11] ARM64: mm: Restore memblock limit when map_mem finished.
From: Steve Capper <hidden>
Date: 2013-05-08 09:53:18
Also in:
linux-arch, linux-mm
Subsystem:
arm64 port (aarch64 architecture), the rest · Maintainers:
Catalin Marinas, Will Deacon, Linus Torvalds
In paging_init the memblock limit is set to restrict any addresses returned by early_alloc to fit within the initial direct kernel mapping in swapper_pg_dir. This allows map_mem to allocate puds, pmds and ptes from the initial direct kernel mapping. The limit stays low after paging_init() though, meaning any bootmem allocations will be from a restricted subset of memory. Gigabyte huge pages, for instance, are normally allocated from bootmem as their order (18) is too large for the default buddy allocator (MAX_ORDER = 11). This patch restores the memblock limit when map_mem has finished, allowing gigabyte huge pages (and other objects) to be allocated from all of bootmem. Signed-off-by: Steve Capper <redacted> --- arch/arm64/mm/mmu.c | 19 +++++++++++++------ 1 file changed, 13 insertions(+), 6 deletions(-)
diff --git a/arch/arm64/mm/mmu.c b/arch/arm64/mm/mmu.c
index 70b8cd4..d23188c 100644
--- a/arch/arm64/mm/mmu.c
+++ b/arch/arm64/mm/mmu.c@@ -297,6 +297,16 @@ static void __init map_mem(void) { struct memblock_region *reg; + /* + * 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 (aligned). + */ + memblock_set_current_limit((PHYS_OFFSET & PGDIR_MASK) + PGDIR_SIZE); + /* map all the memory banks */ for_each_memblock(memory, reg) { phys_addr_t start = reg->base;
@@ -307,6 +317,9 @@ static void __init map_mem(void) create_mapping(start, __phys_to_virt(start), end - start); } + + /* Limit no longer required. */ + memblock_set_current_limit(MEMBLOCK_ALLOC_ANYWHERE); } /*
@@ -317,12 +330,6 @@ void __init paging_init(void) { void *zero_page; - /* - * Maximum PGDIR_SIZE addressable via the initial direct kernel - * mapping in swapper_pg_dir. - */ - memblock_set_current_limit((PHYS_OFFSET & PGDIR_MASK) + PGDIR_SIZE); - init_mem_pgprot(); map_mem();
--
1.8.1.4