diff options
| author | Jungseok Lee <jays.lee@samsung.com> | 2014-05-12 10:40:38 +0100 |
|---|---|---|
| committer | Catalin Marinas <catalin.marinas@arm.com> | 2014-07-23 15:27:21 +0100 |
| commit | e41ceed035966d593ae34c3de33924965a6b9fba (patch) | |
| tree | 505e26883b4914fa6b131902cd6a4b5f9dccc7b2 /arch/arm64/Kconfig | |
| parent | 7edd88ad7e59c2b7b49da0e00f251884fb785d4f (diff) | |
| download | lwn-e41ceed035966d593ae34c3de33924965a6b9fba.tar.gz lwn-e41ceed035966d593ae34c3de33924965a6b9fba.zip | |
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/Kconfig | 45 |
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 |