From 847264fb7e73ade5b5e4b6eea3daa243a1f5217e Mon Sep 17 00:00:00 2001 From: Catalin Marinas Date: Wed, 23 Oct 2013 16:50:07 +0100 Subject: arm64: Use 42-bit address space with 64K pages This patch expands the VA_BITS to 42 when the 64K page configuration is enabled allowing 2TB kernel linear mapping. Linux still uses 2 levels of page tables in this configuration with pgd now being a full page. Signed-off-by: Catalin Marinas Acked-by: Will Deacon Acked-by: Marc Zyngier --- Documentation/arm64/memory.txt | 27 ++++++++++++++++++++++++++- 1 file changed, 26 insertions(+), 1 deletion(-) (limited to 'Documentation/arm64') diff --git a/Documentation/arm64/memory.txt b/Documentation/arm64/memory.txt index f28899d5c83..5e054bfe4dd 100644 --- a/Documentation/arm64/memory.txt +++ b/Documentation/arm64/memory.txt @@ -21,7 +21,7 @@ The swapper_pgd_dir address is written to TTBR1 and never written to TTBR0. -AArch64 Linux memory layout: +AArch64 Linux memory layout with 4KB pages: Start End Size Use ----------------------------------------------------------------------- @@ -46,6 +46,31 @@ ffffffbffc000000 ffffffbfffffffff 64MB modules ffffffc000000000 ffffffffffffffff 256GB kernel logical memory map +AArch64 Linux memory layout with 64KB pages: + +Start End Size Use +----------------------------------------------------------------------- +0000000000000000 000003ffffffffff 4TB user + +fffffc0000000000 fffffdfbfffeffff ~2TB vmalloc + +fffffdfbffff0000 fffffdfbffffffff 64KB [guard page] + +fffffdfc00000000 fffffdfdffffffff 8GB vmemmap + +fffffdfe00000000 fffffdfffbbfffff ~8GB [guard, future vmmemap] + +fffffdfffbc00000 fffffdfffbdfffff 2MB earlyprintk device + +fffffdfffbe00000 fffffdfffbe0ffff 64KB PCI I/O space + +fffffdfffbe10000 fffffdfffbffffff ~2MB [guard] + +fffffdfffc000000 fffffdffffffffff 64MB modules + +fffffe0000000000 ffffffffffffffff 2TB kernel logical memory map + + Translation table lookup with 4KB pages: +--------+--------+--------+--------+--------+--------+--------+--------+ -- cgit v1.2.3