path: root/arch/x86_64/Kconfig

#
# For a description of the syntax of this configuration file,
# see Documentation/kbuild/kconfig-language.txt.
#
# Note: ISA is disabled and will hopefully never be enabled.
# If you managed to buy an ISA x86-64 box you'll have to fix all the
# ISA drivers you need yourself.
#

mainmenu "Linux Kernel Configuration"

config X86_64
	bool
	default y
	help
	  Port to the x86-64 architecture. x86-64 is a 64-bit extension to the
	  classical 32-bit x86 architecture. For details see
	  <http://www.x86-64.org/>.

config 64BIT
	def_bool y

config X86
	bool
	default y

config MMU
	bool
	default y

config ISA
	bool

config SBUS
	bool

config RWSEM_GENERIC_SPINLOCK
	bool
	default y

config RWSEM_XCHGADD_ALGORITHM
	bool

config GENERIC_CALIBRATE_DELAY
	bool
	default y

config X86_CMPXCHG
	bool
	default y

config EARLY_PRINTK
	bool
	default y

config GENERIC_ISA_DMA
	bool
	default y

config GENERIC_IOMAP
	bool
	default y

source "init/Kconfig"


menu "Processor type and features"

choice
	prompt "Processor family"
	default MK8

config MK8
	bool "AMD-Opteron/Athlon64"
	help
	  Optimize for AMD Opteron/Athlon64/Hammer/K8 CPUs.

config MPSC
       bool "Intel EM64T"
       help
	  Optimize for Intel Pentium 4 and Xeon CPUs with Intel
	  Extended Memory 64 Technology(EM64T). For details see
	  <http://www.intel.com/technology/64bitextensions/>.

config GENERIC_CPU
	bool "Generic-x86-64"
	help
	  Generic x86-64 CPU.

endchoice

#
# Define implied options from the CPU selection here
#
config X86_L1_CACHE_BYTES
	int
	default "128" if GENERIC_CPU || MPSC
	default "64" if MK8

config X86_L1_CACHE_SHIFT
	int
	default "7" if GENERIC_CPU || MPSC
	default "6" if MK8

config X86_TSC
	bool
	default y

config X86_GOOD_APIC
	bool
	default y

config MICROCODE
	tristate "/dev/cpu/microcode - Intel CPU microcode support"
	---help---
	  If you say Y here the 'File systems' section, you will be
	  able to update the microcode on Intel processors. You will
	  obviously need the actual microcode binary data itself which is
	  not shipped with the Linux kernel.

	  For latest news and information on obtaining all the required
	  ingredients for this driver, check:
	  <http://www.urbanmyth.org/microcode/>.

	  To compile this driver as a module, choose M here: the
	  module will be called microcode.
	  If you use modprobe or kmod you may also want to add the line
	  'alias char-major-10-184 microcode' to your /etc/modules.conf file.

config X86_MSR
	tristate "/dev/cpu/*/msr - Model-specific register support"
	help
	  This device gives privileged processes access to the x86
	  Model-Specific Registers (MSRs).  It is a character device with
	  major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr.
	  MSR accesses are directed to a specific CPU on multi-processor
	  systems.

config X86_CPUID
	tristate "/dev/cpu/*/cpuid - CPU information support"
	help
	  This device gives processes access to the x86 CPUID instruction to
	  be executed on a specific processor.  It is a character device
	  with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to
	  /dev/cpu/31/cpuid.

# disable it for opteron optimized builds because it pulls in ACPI_BOOT
config X86_HT
	bool
	depends on SMP && !MK8
	default y

config MATH_EMULATION
	bool

config MCA
	bool

config EISA
	bool

config X86_IO_APIC
	bool
	default y

config X86_LOCAL_APIC
	bool
	default y

config MTRR
	bool "MTRR (Memory Type Range Register) support"
	---help---
	  On Intel P6 family processors (Pentium Pro, Pentium II and later)
	  the Memory Type Range Registers (MTRRs) may be used to control
	  processor access to memory ranges. This is most useful if you have
	  a video (VGA) card on a PCI or AGP bus. Enabling write-combining
	  allows bus write transfers to be combined into a larger transfer
	  before bursting over the PCI/AGP bus. This can increase performance
	  of image write operations 2.5 times or more. Saying Y here creates a
	  /proc/mtrr file which may be used to manipulate your processor's
	  MTRRs. Typically the X server should use this.

	  This code has a reasonably generic interface so that similar
	  control registers on other processors can be easily supported
	  as well.

	  Saying Y here also fixes a problem with buggy SMP BIOSes which only
	  set the MTRRs for the boot CPU and not for the secondary CPUs. This
	  can lead to all sorts of problems, so it's good to say Y here.

	  Just say Y here, all x86-64 machines support MTRRs.

	  See <file:Documentation/mtrr.txt> for more information.

config SMP
	bool "Symmetric multi-processing support"
	---help---
	  This enables support for systems with more than one CPU. If you have
	  a system with only one CPU, like most personal computers, say N. If
	  you have a system with more than one CPU, say Y.

	  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,
	  singleprocessor machines. On a singleprocessor machine, the kernel
	  will run faster if you say N here.

	  If you don't know what to do here, say N.

config PREEMPT
	bool "Preemptible Kernel"
	---help---
	  This option reduces the latency of the kernel when reacting to
	  real-time or interactive events by allowing a low priority process to
	  be preempted even if it is in kernel mode executing a system call.
	  This allows applications to run more reliably even when the system is
	  under load. On contrary it may also break your drivers and add
	  priority inheritance problems to your system. Don't select it if
	  you rely on a stable system or have slightly obscure hardware.
	  It's also not very well tested on x86-64 currently.
	  You have been warned.

	  Say Y here if you are feeling brave and building a kernel for a
	  desktop, embedded or real-time system.  Say N if you are unsure.

config PREEMPT_BKL
	bool "Preempt The Big Kernel Lock"
	depends on PREEMPT
	default y
	help
	  This option reduces the latency of the kernel by making the
	  big kernel lock preemptible.

	  Say Y here if you are building a kernel for a desktop system.
	  Say N if you are unsure.

config SCHED_SMT
	bool "SMT (Hyperthreading) scheduler support"
	depends on SMP
	default n
	help
	  SMT scheduler support improves the CPU scheduler's decision making
	  when dealing with Intel Pentium 4 chips with HyperThreading at a
	  cost of slightly increased overhead in some places. If unsure say
	  N here.

config K8_NUMA
       bool "K8 NUMA support"
       select NUMA
       depends on SMP
       help
	  Enable NUMA (Non Unified Memory Architecture) support for
	  AMD Opteron Multiprocessor systems. The kernel will try to allocate
	  memory used by a CPU on the local memory controller of the CPU
	  and add some more NUMA awareness to the kernel.
	  This code is recommended on all multiprocessor Opteron systems
	  and normally doesn't hurt on others.

config NUMA_EMU
	bool "NUMA emulation support"
	select NUMA
	depends on SMP
	help
	  Enable NUMA emulation. A flat machine will be split
	  into virtual nodes when booted with "numa=fake=N", where N is the
	  number of nodes. This is only useful for debugging.

config DISCONTIGMEM
       bool
       depends on NUMA
       default y

config NUMA
       bool
       default n

config HAVE_DEC_LOCK
	bool
	depends on SMP
	default y

config NR_CPUS
	int "Maximum number of CPUs (2-256)"
	range 2 256
	depends on SMP
	default "8"
	help
	  This allows you to specify the maximum number of CPUs which this
	  kernel will support. Current maximum is 256 CPUs due to
	  APIC addressing limits. Less depending on the hardware.

	  This is purely to save memory - each supported CPU requires
	  memory in the static kernel configuration.

config HPET_TIMER
	bool
	default y
	help
	  Use the IA-PC HPET (High Precision Event Timer) to manage
	  time in preference to the PIT and RTC, if a HPET is
	  present.  The HPET provides a stable time base on SMP
	  systems, unlike the TSC, but it is more expensive to access,
	  as it is off-chip.  You can find the HPET spec at
	  <http://www.intel.com/labs/platcomp/hpet/hpetspec.htm>.

config X86_PM_TIMER
	bool "PM timer"
	depends on ACPI
	default y
	help
	  Support the ACPI PM timer for time keeping. This is slow,
	  but is useful on some chipsets without HPET on systems with more
	  than one CPU. On a single processor or single socket multi core
	  system it is normally not required.
	  When the PM timer is active 64bit vsyscalls are disabled
	  and should not be enabled (/proc/sys/kernel/vsyscall64 should
	  not be changed).
	  The kernel selects the PM timer only as a last resort, so it is
	  useful to enable just in case.

config HPET_EMULATE_RTC
	bool "Provide RTC interrupt"
	depends on HPET_TIMER && RTC=y

config GART_IOMMU
	bool "IOMMU support"
	depends on PCI
	help
	  Support the K8 IOMMU. Needed to run systems with more than 4GB of memory
	  properly with 32-bit PCI devices that do not support DAC (Double Address
	  Cycle). The IOMMU can be turned off at runtime with the iommu=off parameter.
	  Normally the kernel will take the right choice by itself.
	  If unsure, say Y.

# need this always enabled with GART_IOMMU for the VIA workaround
config SWIOTLB
       bool
       depends on GART_IOMMU
       default y

config DUMMY_IOMMU
	bool
	depends on !GART_IOMMU && !SWIOTLB
	default y
	help
	  Don't use IOMMU code. This will cause problems when you have more than 4GB
	  of memory and any 32-bit devices. Don't turn on unless you know what you
	  are doing.

config X86_MCE
	bool "Machine check support" if EMBEDDED
	default y
	help
	   Include a machine check error handler to report hardware errors.
	   This version will require the mcelog utility to decode some
	   machine check error logs. See
	   ftp://ftp.x86-64.org/pub/linux/tools/mcelog

config X86_MCE_INTEL
	bool "Intel MCE features"
	depends on X86_MCE && X86_LOCAL_APIC
	default y
	help
	   Additional support for intel specific MCE features such as
	   the thermal monitor.

config SECCOMP
	bool "Enable seccomp to safely compute untrusted bytecode"
	depends on PROC_FS
	default y
	help
	  This kernel feature is useful for number crunching applications
	  that may need to compute untrusted bytecode during their
	  execution. By using pipes or other transports made available to
	  the process as file descriptors supporting the read/write
	  syscalls, it's possible to isolate those applications in
	  their own address space using seccomp. Once seccomp is
	  enabled via /proc/<pid>/seccomp, it cannot be disabled
	  and the task is only allowed to execute a few safe syscalls
	  defined by each seccomp mode.

	  If unsure, say Y. Only embedded should say N here.

endmenu

#
# Use the generic interrupt handling code in kernel/irq/:
#
config GENERIC_HARDIRQS
	bool
	default y

config GENERIC_IRQ_PROBE
	bool
	default y

# we have no ISA slots, but we do have ISA-style DMA.
config ISA_DMA_API
	bool
	default y

menu "Power management options"

source kernel/power/Kconfig

source "drivers/acpi/Kconfig"

source "arch/x86_64/kernel/cpufreq/Kconfig"

endmenu

menu "Bus options (PCI etc.)"

config PCI
	bool "PCI support"

# x86-64 doesn't support PCI BIOS access from long mode so always go direct.
config PCI_DIRECT
	bool
	depends on PCI
	default y

config PCI_MMCONFIG
	bool "Support mmconfig PCI config space access"
	depends on PCI && ACPI
	select ACPI_BOOT

config UNORDERED_IO
       bool "Unordered IO mapping access"
       depends on EXPERIMENTAL
       help
         Use unordered stores to access IO memory mappings in device drivers.
	 Still very experimental. When a driver works on IA64/ppc64/pa-risc it should
	 work with this option, but it makes the drivers behave differently
	 from i386. Requires that the driver writer used memory barriers
	 properly.

source "drivers/pci/pcie/Kconfig"

source "drivers/pci/Kconfig"

source "drivers/pcmcia/Kconfig"

source "drivers/pci/hotplug/Kconfig"

endmenu


menu "Executable file formats / Emulations"

source "fs/Kconfig.binfmt"

config IA32_EMULATION
	bool "IA32 Emulation"
	help
	  Include code to run 32-bit programs under a 64-bit kernel. You should likely
	  turn this on, unless you're 100% sure that you don't have any 32-bit programs
	  left.

config IA32_AOUT
       bool "IA32 a.out support"
       depends on IA32_EMULATION
       help
         Support old a.out binaries in the 32bit emulation.

config COMPAT
	bool
	depends on IA32_EMULATION
	default y

config SYSVIPC_COMPAT
	bool
	depends on COMPAT && SYSVIPC
	default y

config UID16
	bool
	depends on IA32_EMULATION
	default y

endmenu

source drivers/Kconfig

source "drivers/firmware/Kconfig"

source fs/Kconfig

source "arch/x86_64/oprofile/Kconfig"

source "arch/x86_64/Kconfig.debug"

source "security/Kconfig"

source "crypto/Kconfig"

source "lib/Kconfig"