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authorJungseok Lee <jays.lee@samsung.com>2014-05-12 10:40:38 +0100
committerCatalin Marinas <catalin.marinas@arm.com>2014-07-23 15:27:21 +0100
commite41ceed035966d593ae34c3de33924965a6b9fba (patch)
tree505e26883b4914fa6b131902cd6a4b5f9dccc7b2 /arch/arm64/Kconfig
parent7edd88ad7e59c2b7b49da0e00f251884fb785d4f (diff)
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arm64: Introduce VA_BITS and translation level options
This patch adds virtual address space size and a level of translation tables to kernel configuration. It facilicates introduction of different MMU options, such as 4KB + 4 levels, 16KB + 4 levels and 64KB + 3 levels, easily. The idea is based on the discussion with Catalin Marinas: http://www.spinics.net/linux/lists/arm-kernel/msg319552.html Signed-off-by: Jungseok Lee <jays.lee@samsung.com> Reviewed-by: Sungjinn Chung <sungjinn.chung@samsung.com> Acked-by: Kukjin Kim <kgene.kim@samsung.com> Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> Tested-by: Jungseok Lee <jungseoklee85@gmail.com>
Diffstat (limited to 'arch/arm64/Kconfig')
-rw-r--r--arch/arm64/Kconfig45
1 files changed, 44 insertions, 1 deletions
diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
index 95cda2be0695..94ba45b198ff 100644
--- a/arch/arm64/Kconfig
+++ b/arch/arm64/Kconfig
@@ -157,14 +157,57 @@ endmenu
menu "Kernel Features"
+choice
+ prompt "Page size"
+ default ARM64_4K_PAGES
+ help
+ Page size (translation granule) configuration.
+
+config ARM64_4K_PAGES
+ bool "4KB"
+ help
+ This feature enables 4KB pages support.
+
config ARM64_64K_PAGES
- bool "Enable 64KB pages support"
+ bool "64KB"
help
This feature enables 64KB pages support (4KB by default)
allowing only two levels of page tables and faster TLB
look-up. AArch32 emulation is not available when this feature
is enabled.
+endchoice
+
+choice
+ prompt "Virtual address space size"
+ default ARM64_VA_BITS_39 if ARM64_4K_PAGES
+ default ARM64_VA_BITS_42 if ARM64_64K_PAGES
+ help
+ Allows choosing one of multiple possible virtual address
+ space sizes. The level of translation table is determined by
+ a combination of page size and virtual address space size.
+
+config ARM64_VA_BITS_39
+ bool "39-bit"
+ depends on ARM64_4K_PAGES
+
+config ARM64_VA_BITS_42
+ bool "42-bit"
+ depends on ARM64_64K_PAGES
+
+endchoice
+
+config ARM64_VA_BITS
+ int
+ default 39 if ARM64_VA_BITS_39
+ default 42 if ARM64_VA_BITS_42
+
+config ARM64_2_LEVELS
+ def_bool y if ARM64_64K_PAGES && ARM64_VA_BITS_42
+
+config ARM64_3_LEVELS
+ def_bool y if ARM64_4K_PAGES && ARM64_VA_BITS_39
+
config CPU_BIG_ENDIAN
bool "Build big-endian kernel"
help