arm64: 36 bit VA

36bit VA lets us use 2 level page tables while limiting the
available address space to 64GB.

Cc: Will Deacon <will.deacon@arm.com>
Cc: Steve Capper <steve.capper@linaro.org>
Signed-off-by: Suzuki K. Poulose <suzuki.poulose@arm.com>
Reviewed-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Tested-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
This commit is contained in:
Suzuki K. Poulose 2015-10-19 14:19:38 +01:00 committed by Catalin Marinas
parent 44eaacf1b8
commit 215399392f

View File

@ -170,6 +170,7 @@ config FIX_EARLYCON_MEM
config PGTABLE_LEVELS
int
default 2 if ARM64_16K_PAGES && ARM64_VA_BITS_36
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
@ -391,6 +392,10 @@ choice
space sizes. The level of translation table is determined by
a combination of page size and virtual address space size.
config ARM64_VA_BITS_36
bool "36-bit"
depends on ARM64_16K_PAGES
config ARM64_VA_BITS_39
bool "39-bit"
depends on ARM64_4K_PAGES
@ -410,6 +415,7 @@ endchoice
config ARM64_VA_BITS
int
default 36 if ARM64_VA_BITS_36
default 39 if ARM64_VA_BITS_39
default 42 if ARM64_VA_BITS_42
default 47 if ARM64_VA_BITS_47
@ -480,7 +486,7 @@ config ARCH_WANT_GENERAL_HUGETLB
def_bool y
config ARCH_WANT_HUGE_PMD_SHARE
def_bool y if ARM64_4K_PAGES || ARM64_16K_PAGES
def_bool y if ARM64_4K_PAGES || (ARM64_16K_PAGES && !ARM64_VA_BITS_36)
config HAVE_ARCH_TRANSPARENT_HUGEPAGE
def_bool y