arch/i386/Kconfig.cpu

# Put here option for CPU selection and depending optimization
if !X86_ELAN

choice
	prompt "Processor family"
	default M686

config M386
	bool "386"
	depends on !UML
	---help---
	  This is the processor type of your CPU. This information is used for
	  optimizing purposes. In order to compile a kernel that can run on
	  all x86 CPU types (albeit not optimally fast), you can specify
	  "386" here.

	  The kernel will not necessarily run on earlier architectures than
	  the one you have chosen, e.g. a Pentium optimized kernel will run on
	  a PPro, but not necessarily on a i486.

	  Here are the settings recommended for greatest speed:
	  - "386" for the AMD/Cyrix/Intel 386DX/DXL/SL/SLC/SX, Cyrix/TI
	  486DLC/DLC2, UMC 486SX-S and NexGen Nx586.  Only "386" kernels
	  will run on a 386 class machine.
	  - "486" for the AMD/Cyrix/IBM/Intel 486DX/DX2/DX4 or
	  SL/SLC/SLC2/SLC3/SX/SX2 and UMC U5D or U5S.
	  - "586" for generic Pentium CPUs lacking the TSC
	  (time stamp counter) register.
	  - "Pentium-Classic" for the Intel Pentium.
	  - "Pentium-MMX" for the Intel Pentium MMX.
	  - "Pentium-Pro" for the Intel Pentium Pro.
	  - "Pentium-II" for the Intel Pentium II or pre-Coppermine Celeron.
	  - "Pentium-III" for the Intel Pentium III or Coppermine Celeron.
	  - "Pentium-4" for the Intel Pentium 4 or P4-based Celeron.
	  - "K6" for the AMD K6, K6-II and K6-III (aka K6-3D).
	  - "Athlon" for the AMD K7 family (Athlon/Duron/Thunderbird).
	  - "Crusoe" for the Transmeta Crusoe series.
	  - "Efficeon" for the Transmeta Efficeon series.
	  - "Winchip-C6" for original IDT Winchip.
	  - "Winchip-2" for IDT Winchip 2.
	  - "Winchip-2A" for IDT Winchips with 3dNow! capabilities.
	  - "GeodeGX1" for Geode GX1 (Cyrix MediaGX).
	  - "Geode GX/LX" For AMD Geode GX and LX processors.
	  - "CyrixIII/VIA C3" for VIA Cyrix III or VIA C3.
	  - "VIA C3-2" for VIA C3-2 "Nehemiah" (model 9 and above).
	  - "VIA C7" for VIA C7.

	  If you don't know what to do, choose "386".

config M486
	bool "486"
	help
	  Select this for a 486 series processor, either Intel or one of the
	  compatible processors from AMD, Cyrix, IBM, or Intel.  Includes DX,
	  DX2, and DX4 variants; also SL/SLC/SLC2/SLC3/SX/SX2 and UMC U5D or
	  U5S.

config M586
	bool "586/K5/5x86/6x86/6x86MX"
	help
	  Select this for an 586 or 686 series processor such as the AMD K5,
	  the Cyrix 5x86, 6x86 and 6x86MX.  This choice does not
	  assume the RDTSC (Read Time Stamp Counter) instruction.

config M586TSC
	bool "Pentium-Classic"
	help
	  Select this for a Pentium Classic processor with the RDTSC (Read
	  Time Stamp Counter) instruction for benchmarking.

config M586MMX
	bool "Pentium-MMX"
	help
	  Select this for a Pentium with the MMX graphics/multimedia
	  extended instructions.

config M686
	bool "Pentium-Pro"
	help
	  Select this for Intel Pentium Pro chips.  This enables the use of
	  Pentium Pro extended instructions, and disables the init-time guard
	  against the f00f bug found in earlier Pentiums.

config MPENTIUMII
	bool "Pentium-II/Celeron(pre-Coppermine)"
	help
	  Select this for Intel chips based on the Pentium-II and
	  pre-Coppermine Celeron core.  This option enables an unaligned
	  copy optimization, compiles the kernel with optimization flags
	  tailored for the chip, and applies any applicable Pentium Pro
	  optimizations.

config MPENTIUMIII
	bool "Pentium-III/Celeron(Coppermine)/Pentium-III Xeon"
	help
	  Select this for Intel chips based on the Pentium-III and
	  Celeron-Coppermine core.  This option enables use of some
	  extended prefetch instructions in addition to the Pentium II
	  extensions.

config MPENTIUMM
	bool "Pentium M"
	help
	  Select this for Intel Pentium M (not Pentium-4 M)
	  notebook chips.

config MCORE2
	bool "Core 2/newer Xeon"
	help
	  Select this for Intel Core 2 and newer Core 2 Xeons (Xeon 51xx and 53xx)
	  CPUs. You can distinguish newer from older Xeons by the CPU family
	  in /proc/cpuinfo. Newer ones have 6.

config MPENTIUM4
	bool "Pentium-4/Celeron(P4-based)/Pentium-4 M/older Xeon"
	help
	  Select this for Intel Pentium 4 chips.  This includes the
	  Pentium 4, P4-based Celeron and Xeon, and Pentium-4 M
	  (not Pentium M) chips.  This option enables compile flags
	  optimized for the chip, uses the correct cache shift, and
	  applies any applicable Pentium III optimizations.

config MK6
	bool "K6/K6-II/K6-III"
	help
	  Select this for an AMD K6-family processor.  Enables use of
	  some extended instructions, and passes appropriate optimization
	  flags to GCC.

config MK7
	bool "Athlon/Duron/K7"
	help
	  Select this for an AMD Athlon K7-family processor.  Enables use of
	  some extended instructions, and passes appropriate optimization
	  flags to GCC.

config MK8
	bool "Opteron/Athlon64/Hammer/K8"
	help
	  Select this for an AMD Opteron or Athlon64 Hammer-family processor.  Enables
	  use of some extended instructions, and passes appropriate optimization
	  flags to GCC.

config MCRUSOE
	bool "Crusoe"
	help
	  Select this for a Transmeta Crusoe processor.  Treats the processor
	  like a 586 with TSC, and sets some GCC optimization flags (like a
	  Pentium Pro with no alignment requirements).

config MEFFICEON
	bool "Efficeon"
	help
	  Select this for a Transmeta Efficeon processor.

config MWINCHIPC6
	bool "Winchip-C6"
	help
	  Select this for an IDT Winchip C6 chip.  Linux and GCC
	  treat this chip as a 586TSC with some extended instructions
	  and alignment requirements.

config MWINCHIP2
	bool "Winchip-2"
	help
	  Select this for an IDT Winchip-2.  Linux and GCC
	  treat this chip as a 586TSC with some extended instructions
	  and alignment requirements.

config MWINCHIP3D
	bool "Winchip-2A/Winchip-3"
	help
	  Select this for an IDT Winchip-2A or 3.  Linux and GCC
	  treat this chip as a 586TSC with some extended instructions
	  and alignment requirements.  Also enable out of order memory
	  stores for this CPU, which can increase performance of some
	  operations.

config MGEODEGX1
	bool "GeodeGX1"
	help
	  Select this for a Geode GX1 (Cyrix MediaGX) chip.

config MGEODE_LX
       bool "Geode GX/LX"
       help
         Select this for AMD Geode GX and LX processors.

config MCYRIXIII
	bool "CyrixIII/VIA-C3"
	help
	  Select this for a Cyrix III or C3 chip.  Presently Linux and GCC
	  treat this chip as a generic 586. Whilst the CPU is 686 class,
	  it lacks the cmov extension which gcc assumes is present when
	  generating 686 code.
	  Note that Nehemiah (Model 9) and above will not boot with this
	  kernel due to them lacking the 3DNow! instructions used in earlier
	  incarnations of the CPU.

config MVIAC3_2
	bool "VIA C3-2 (Nehemiah)"
	help
	  Select this for a VIA C3 "Nehemiah". Selecting this enables usage
	  of SSE and tells gcc to treat the CPU as a 686.
	  Note, this kernel will not boot on older (pre model 9) C3s.

config MVIAC7
	bool "VIA C7"
	help
	  Select this for a VIA C7.  Selecting this uses the correct cache
	  shift and tells gcc to treat the CPU as a 686.

endchoice

config X86_GENERIC
       bool "Generic x86 support"
       help
	  Instead of just including optimizations for the selected
	  x86 variant (e.g. PII, Crusoe or Athlon), include some more
	  generic optimizations as well. This will make the kernel
	  perform better on x86 CPUs other than that selected.

	  This is really intended for distributors who need more
	  generic optimizations.

endif

#
# Define implied options from the CPU selection here
#
config X86_CMPXCHG
	bool
	depends on !M386
	default y

config X86_L1_CACHE_SHIFT
	int
	default "7" if MPENTIUM4 || X86_GENERIC
	default "4" if X86_ELAN || M486 || M386 || MGEODEGX1
	default "5" if MWINCHIP3D || MWINCHIP2 || MWINCHIPC6 || MCRUSOE || MEFFICEON || MCYRIXIII || MK6 || MPENTIUMIII || MPENTIUMII || M686 || M586MMX || M586TSC || M586 || MVIAC3_2 || MGEODE_LX
	default "6" if MK7 || MK8 || MPENTIUMM || MCORE2 || MVIAC7

config X86_XADD
	bool
	depends on !M386
	default y

config RWSEM_GENERIC_SPINLOCK
	bool
	depends on !X86_XADD
	default y

config RWSEM_XCHGADD_ALGORITHM
	bool
	depends on X86_XADD
	default y

config ARCH_HAS_ILOG2_U32
	bool
	default n

config ARCH_HAS_ILOG2_U64
	bool
	default n

config GENERIC_CALIBRATE_DELAY
	bool
	default y

config X86_PPRO_FENCE
	bool
	depends on M686 || M586MMX || M586TSC || M586 || M486 || M386 || MGEODEGX1
	default y

config X86_F00F_BUG
	bool
	depends on M586MMX || M586TSC || M586 || M486 || M386
	default y

config X86_WP_WORKS_OK
	bool
	depends on !M386
	default y

config X86_INVLPG
	bool
	depends on !M386
	default y

config X86_BSWAP
	bool
	depends on !M386
	default y

config X86_POPAD_OK
	bool
	depends on !M386
	default y

config X86_ALIGNMENT_16
	bool
	depends on MWINCHIP3D || MWINCHIP2 || MWINCHIPC6 || MCYRIXIII || X86_ELAN || MK6 || M586MMX || M586TSC || M586 || M486 || MVIAC3_2 || MGEODEGX1
	default y

config X86_GOOD_APIC
	bool
	depends on MK7 || MPENTIUM4 || MPENTIUMM || MPENTIUMIII || MPENTIUMII || M686 || M586MMX || MK8 || MEFFICEON || MCORE2 || MVIAC7
	default y

config X86_INTEL_USERCOPY
	bool
	depends on MPENTIUM4 || MPENTIUMM || MPENTIUMIII || MPENTIUMII || M586MMX || X86_GENERIC || MK8 || MK7 || MEFFICEON || MCORE2
	default y

config X86_USE_PPRO_CHECKSUM
	bool
	depends on MWINCHIP3D || MWINCHIP2 || MWINCHIPC6 || MCYRIXIII || MK7 || MK6 || MPENTIUM4 || MPENTIUMM || MPENTIUMIII || MPENTIUMII || M686 || MK8 || MVIAC3_2 || MEFFICEON || MGEODE_LX || MCORE2
	default y

config X86_USE_3DNOW
	bool
	depends on (MCYRIXIII || MK7 || MGEODE_LX) && !UML
	default y

config X86_OOSTORE
	bool
	depends on (MWINCHIP3D || MWINCHIP2 || MWINCHIPC6) && MTRR
	default y

config X86_TSC
	bool
	depends on (MWINCHIP3D || MWINCHIP2 || MCRUSOE || MEFFICEON || MCYRIXIII || MK7 || MK6 || MPENTIUM4 || MPENTIUMM || MPENTIUMIII || MPENTIUMII || M686 || M586MMX || M586TSC || MK8 || MVIAC3_2 || MVIAC7 || MGEODEGX1 || MGEODE_LX || MCORE2) && !X86_NUMAQ
	default y

# this should be set for all -march=.. options where the compiler
# generates cmov.
config X86_CMOV
	bool
	depends on (MK7 || MPENTIUM4 || MPENTIUMM || MPENTIUMIII || MPENTIUMII || M686 || MVIAC3_2 || MVIAC7)
	default y

config X86_MINIMUM_CPU_FAMILY
	int
	default "4" if X86_XADD || X86_CMPXCHG || X86_BSWAP || X86_WP_WORKS_OK
	default "3"