From 383c2799113b00a5f12c820ff0fd3dfca9e5be89 Mon Sep 17 00:00:00 2001 From: Catalin Marinas Date: Mon, 21 Jul 2014 15:54:50 +0100 Subject: [PATCH] arm64: Add support for 48-bit VA space with 64KB page configuration This patch allows support for 3 levels of page tables with 64KB page configuration allowing 48-bit VA space. The pgd is no longer a full PAGE_SIZE (PTRS_PER_PGD is 64) and (swapper|idmap)_pg_dir are not fully populated (pgd_alloc falls back to kzalloc). Signed-off-by: Catalin Marinas Tested-by: Jungseok Lee --- Documentation/arm64/memory.txt | 8 ++++++++ arch/arm64/Kconfig | 1 + arch/arm64/include/asm/page.h | 16 +++++++++------- arch/arm64/kernel/head.S | 6 ++++-- 4 files changed, 22 insertions(+), 9 deletions(-) diff --git a/Documentation/arm64/memory.txt b/Documentation/arm64/memory.txt index 8845d0847a66..344e85cc7323 100644 --- a/Documentation/arm64/memory.txt +++ b/Documentation/arm64/memory.txt @@ -45,6 +45,14 @@ Start End Size Use fffffc0000000000 ffffffffffffffff 4TB kernel +AArch64 Linux memory layout with 64KB pages + 3 levels: + +Start End Size Use +----------------------------------------------------------------------- +0000000000000000 0000ffffffffffff 256TB user +ffff000000000000 ffffffffffffffff 256TB kernel + + For details of the virtual kernel memory layout please see the kernel booting log. diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig index 8cdb7f36bfc8..f4615ba88a77 100644 --- a/arch/arm64/Kconfig +++ b/arch/arm64/Kconfig @@ -210,6 +210,7 @@ config ARM64_VA_BITS config ARM64_PGTABLE_LEVELS int default 2 if ARM64_64K_PAGES && ARM64_VA_BITS_42 + default 3 if ARM64_64K_PAGES && ARM64_VA_BITS_48 default 3 if ARM64_4K_PAGES && ARM64_VA_BITS_39 default 4 if ARM64_4K_PAGES && ARM64_VA_BITS_48 diff --git a/arch/arm64/include/asm/page.h b/arch/arm64/include/asm/page.h index 2502754d1921..7a3f462133b0 100644 --- a/arch/arm64/include/asm/page.h +++ b/arch/arm64/include/asm/page.h @@ -34,17 +34,19 @@ /* * The idmap and swapper page tables need some space reserved in the kernel * image. Both require pgd, pud (4 levels only) and pmd tables to (section) - * map the kernel. The swapper also maps the FDT (see __create_page_tables for - * more information). + * map the kernel. With the 64K page configuration, swapper and idmap need to + * map to pte level. The swapper also maps the FDT (see __create_page_tables + * for more information). */ -#if CONFIG_ARM64_PGTABLE_LEVELS == 4 -#define SWAPPER_DIR_SIZE (3 * PAGE_SIZE) -#define IDMAP_DIR_SIZE (3 * PAGE_SIZE) +#ifdef CONFIG_ARM64_64K_PAGES +#define SWAPPER_PGTABLE_LEVELS (CONFIG_ARM64_PGTABLE_LEVELS) #else -#define SWAPPER_DIR_SIZE (2 * PAGE_SIZE) -#define IDMAP_DIR_SIZE (2 * PAGE_SIZE) +#define SWAPPER_PGTABLE_LEVELS (CONFIG_ARM64_PGTABLE_LEVELS - 1) #endif +#define SWAPPER_DIR_SIZE (SWAPPER_PGTABLE_LEVELS * PAGE_SIZE) +#define IDMAP_DIR_SIZE (SWAPPER_DIR_SIZE) + #ifndef __ASSEMBLY__ #include diff --git a/arch/arm64/kernel/head.S b/arch/arm64/kernel/head.S index a6db505411bc..0bce493495e9 100644 --- a/arch/arm64/kernel/head.S +++ b/arch/arm64/kernel/head.S @@ -55,9 +55,11 @@ #ifdef CONFIG_ARM64_64K_PAGES #define BLOCK_SHIFT PAGE_SHIFT #define BLOCK_SIZE PAGE_SIZE +#define TABLE_SHIFT PMD_SHIFT #else #define BLOCK_SHIFT SECTION_SHIFT #define BLOCK_SIZE SECTION_SIZE +#define TABLE_SHIFT PUD_SHIFT #endif #define KERNEL_START KERNEL_RAM_VADDR @@ -505,8 +507,8 @@ ENDPROC(__calc_phys_offset) */ .macro create_pgd_entry, tbl, virt, tmp1, tmp2 create_table_entry \tbl, \virt, PGDIR_SHIFT, PTRS_PER_PGD, \tmp1, \tmp2 -#if CONFIG_ARM64_PGTABLE_LEVELS == 4 - create_table_entry \tbl, \virt, PUD_SHIFT, PTRS_PER_PUD, \tmp1, \tmp2 +#if SWAPPER_PGTABLE_LEVELS == 3 + create_table_entry \tbl, \virt, TABLE_SHIFT, PTRS_PER_PTE, \tmp1, \tmp2 #endif .endm