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Commit 3dec0fe4 authored by Catalin Marinas's avatar Catalin Marinas
Browse files

arm64: Fix memblock current_limit with 64K pages and 48-bit VA 



With 48-bit VA space, the 64K page configuration uses 3 levels instead
of 2 and PUD_SIZE != PMD_SIZE. Since with 64K pages we only cover
PMD_SIZE with the initial swapper_pg_dir populated in head.S, the
memblock current_limit needs to be set accordingly in map_mem() to avoid
allocating unmapped memory. The memblock current_limit is progressively
increased as more blocks are mapped.

Signed-off-by: default avatarCatalin Marinas <catalin.marinas@arm.com>
parent 92980405

arch/arm64/mm/mmu.c

+8 −4
Original line number Diff line number Diff line
@@ -297,10 +297,14 @@ static void __init map_mem(void) 
	 * 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 PUD_SIZE memory starting from PHYS_OFFSET (which must be

	 * aligned to 2MB as per Documentation/arm64/booting.txt).

	 * The initial direct kernel mapping, located at swapper_pg_dir, gives

	 * us PUD_SIZE (4K pages) or PMD_SIZE (64K pages) memory starting from

	 * PHYS_OFFSET (which must be aligned to 2MB as per

	 * Documentation/arm64/booting.txt).

	 */

	if (IS_ENABLED(CONFIG_ARM64_64K_PAGES))

		limit = PHYS_OFFSET + PMD_SIZE;

	else

		limit = PHYS_OFFSET + PUD_SIZE;

	memblock_set_current_limit(limit);