select BUILDTIME_EXTABLE_SORT
select CLONE_BACKWARDS
select COMMON_CLK
- select EDAC_SUPPORT
select CPU_PM if (SUSPEND || CPU_IDLE)
select DCACHE_WORD_ACCESS
+ select EDAC_SUPPORT
select GENERIC_ALLOCATOR
select GENERIC_CLOCKEVENTS
- select GENERIC_CLOCKEVENTS_BROADCAST if SMP
+ select GENERIC_CLOCKEVENTS_BROADCAST
select GENERIC_CPU_AUTOPROBE
select GENERIC_EARLY_IOREMAP
select GENERIC_IRQ_PROBE
config NEED_SG_DMA_LENGTH
def_bool y
+config SMP
+ def_bool y
+
config SWIOTLB
def_bool y
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
Say Y if you plan on running a kernel in big-endian mode.
-config SMP
- bool "Symmetric Multi-Processing"
- help
- This enables support for systems with more than one CPU. If
- you say N here, the kernel will run on single and
- multiprocessor machines, but will use only one CPU of a
- multiprocessor machine. If you say Y here, the kernel will run
- on many, but not all, single processor machines. On a single
- processor machine, the kernel will run faster if you say N
- here.
-
- If you don't know what to do here, say N.
-
config SCHED_MC
bool "Multi-core scheduler support"
- depends on SMP
help
Multi-core scheduler support improves the CPU scheduler's decision
making when dealing with multi-core CPU chips at a cost of slightly
config SCHED_SMT
bool "SMT scheduler support"
- depends on SMP
help
Improves the CPU scheduler's decision making when dealing with
MultiThreading at a cost of slightly increased overhead in some
config NR_CPUS
int "Maximum number of CPUs (2-4096)"
range 2 4096
- depends on SMP
# These have to remain sorted largest to smallest
default "64"
config HOTPLUG_CPU
bool "Support for hot-pluggable CPUs"
- depends on SMP
help
Say Y here to experiment with turning CPUs off and on. CPUs
can be controlled through /sys/devices/system/cpu.
source kernel/Kconfig.preempt
-config UP_LATE_INIT
- def_bool y
- depends on !SMP
-
config HZ
int
default 100
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.
+
menuconfig ARMV8_DEPRECATED
bool "Emulate deprecated/obsolete ARMv8 instructions"
depends on COMPAT