From: "Suzuki K. Poulose" <suzuki.poul...@arm.com>
36bit VA lets us use 2 level page tables while limiting the
available address space to 64GB.
Cc: Mark Rutland <mark.rutl...@arm.com>
Cc: Catalin Marinas <catalin.mari...@arm.com>
Cc: Will Deacon <will.dea...@arm.com>
Signed-off-by: Suzuki K. Poulose <suzuki.poul...@arm.com>
---
arch/arm64/Kconfig | 8 +++++++-
1 file changed, 7 insertions(+), 1 deletion(-)
diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
index 8327edf..0407fd3 100644
--- a/arch/arm64/Kconfig
+++ b/arch/arm64/Kconfig
@@ -164,6 +164,7 @@ 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
@@ -472,6 +473,10 @@ 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
@@ -491,6 +496,7 @@ 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
@@ -564,7 +570,7 @@ 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
--
1.7.9.5
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