diff options
Diffstat (limited to 'arch/arm64/Kconfig')
| -rw-r--r-- | arch/arm64/Kconfig | 90 |
1 files changed, 47 insertions, 43 deletions
diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig index e82b98dfc028..371a987b3c11 100644 --- a/arch/arm64/Kconfig +++ b/arch/arm64/Kconfig @@ -481,23 +481,6 @@ config ARM64_VA_BITS default 42 if ARM64_VA_BITS_42 default 48 if ARM64_VA_BITS_48 -config ARM64_HW_AFDBM - bool "Support for hardware updates of the Access and Dirty page flags" - default y - help - The ARMv8.1 architecture extensions introduce support for - hardware updates of the access and dirty information in page - table entries. When enabled in TCR_EL1 (HA and HD bits) on - capable processors, accesses to pages with PTE_AF cleared will - set this bit instead of raising an access flag fault. - Similarly, writes to read-only pages with the DBM bit set will - clear the read-only bit (AP[2]) instead of raising a - permission fault. - - Kernels built with this configuration option enabled continue - to work on pre-ARMv8.1 hardware and the performance impact is - minimal. If unsure, say Y. - config CPU_BIG_ENDIAN bool "Build big-endian kernel" help @@ -605,32 +588,6 @@ config FORCE_MAX_ZONEORDER default "14" if (ARM64_64K_PAGES && TRANSPARENT_HUGEPAGE) default "11" -config ARM64_PAN - bool "Enable support for Privileged Access Never (PAN)" - default y - help - Privileged Access Never (PAN; part of the ARMv8.1 Extensions) - prevents the kernel or hypervisor from accessing user-space (EL0) - memory directly. - - Choosing this option will cause any unprotected (not using - copy_to_user et al) memory access to fail with a permission fault. - - The feature is detected at runtime, and will remain as a 'nop' - instruction if the cpu does not implement the feature. - -config ARM64_LSE_ATOMICS - bool "ARMv8.1 atomic instructions" - help - As part of the Large System Extensions, ARMv8.1 introduces new - atomic instructions that are designed specifically to scale in - very large systems. - - Say Y here to make use of these instructions for the in-kernel - atomic routines. This incurs a small overhead on CPUs that do - not support these instructions and requires the kernel to be - built with binutils >= 2.25. - menuconfig ARMV8_DEPRECATED bool "Emulate deprecated/obsolete ARMv8 instructions" depends on COMPAT @@ -698,6 +655,53 @@ config SETEND_EMULATION If unsure, say Y endif +menu "ARMv8.1 architectural features" + +config ARM64_HW_AFDBM + bool "Support for hardware updates of the Access and Dirty page flags" + default y + help + The ARMv8.1 architecture extensions introduce support for + hardware updates of the access and dirty information in page + table entries. When enabled in TCR_EL1 (HA and HD bits) on + capable processors, accesses to pages with PTE_AF cleared will + set this bit instead of raising an access flag fault. + Similarly, writes to read-only pages with the DBM bit set will + clear the read-only bit (AP[2]) instead of raising a + permission fault. + + Kernels built with this configuration option enabled continue + to work on pre-ARMv8.1 hardware and the performance impact is + minimal. If unsure, say Y. + +config ARM64_PAN + bool "Enable support for Privileged Access Never (PAN)" + default y + help + Privileged Access Never (PAN; part of the ARMv8.1 Extensions) + prevents the kernel or hypervisor from accessing user-space (EL0) + memory directly. + + Choosing this option will cause any unprotected (not using + copy_to_user et al) memory access to fail with a permission fault. + + The feature is detected at runtime, and will remain as a 'nop' + instruction if the cpu does not implement the feature. + +config ARM64_LSE_ATOMICS + bool "Atomic instructions" + help + As part of the Large System Extensions, ARMv8.1 introduces new + atomic instructions that are designed specifically to scale in + very large systems. + + Say Y here to make use of these instructions for the in-kernel + atomic routines. This incurs a small overhead on CPUs that do + not support these instructions and requires the kernel to be + built with binutils >= 2.25. + +endmenu + endmenu menu "Boot options" |