diff options
Diffstat (limited to 'arch/arm/mm/Kconfig')
| -rw-r--r-- | arch/arm/mm/Kconfig | 35 |
1 files changed, 35 insertions, 0 deletions
diff --git a/arch/arm/mm/Kconfig b/arch/arm/mm/Kconfig index a099efed0e63..49db8b3e4a49 100644 --- a/arch/arm/mm/Kconfig +++ b/arch/arm/mm/Kconfig @@ -605,6 +605,14 @@ config CPU_CP15_MPU help Processor has the CP15 register, which has MPU related registers. +config CPU_USE_DOMAINS + bool + depends on MMU + default y if !CPU_32v6K + help + This option enables or disables the use of domain switching + via the set_fs() function. + # # CPU supports 36-bit I/O # @@ -634,6 +642,33 @@ config ARM_THUMBEE Say Y here if you have a CPU with the ThumbEE extension and code to make use of it. Say N for code that can run on CPUs without ThumbEE. +config SWP_EMULATE + bool "Emulate SWP/SWPB instructions" + depends on CPU_V7 + select HAVE_PROC_CPU if PROC_FS + default y if SMP + help + ARMv6 architecture deprecates use of the SWP/SWPB instructions. + ARMv7 multiprocessing extensions introduce the ability to disable + these instructions, triggering an undefined instruction exception + when executed. Say Y here to enable software emulation of these + instructions for userspace (not kernel) using LDREX/STREX. + Also creates /proc/cpu/swp_emulation for statistics. + + In some older versions of glibc [<=2.8] SWP is used during futex + trylock() operations with the assumption that the code will not + be preempted. This invalid assumption may be more likely to fail + with SWP emulation enabled, leading to deadlock of the user + application. + + NOTE: when accessing uncached shared regions, LDREX/STREX rely + on an external transaction monitoring block called a global + monitor to maintain update atomicity. If your system does not + implement a global monitor, this option can cause programs that + perform SWP operations to uncached memory to deadlock. + + If unsure, say Y. + config CPU_BIG_ENDIAN bool "Build big-endian kernel" depends on ARCH_SUPPORTS_BIG_ENDIAN |