Kconfig 92.7 KB
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# SPDX-License-Identifier: GPL-2.0
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# Select 32 or 64 bit
config 64BIT
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	bool "64-bit kernel" if ARCH = "x86"
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	default ARCH != "i386"
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	---help---
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	  Say yes to build a 64-bit kernel - formerly known as x86_64
	  Say no to build a 32-bit kernel - formerly known as i386

config X86_32
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	def_bool y
	depends on !64BIT
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	# Options that are inherently 32-bit kernel only:
	select ARCH_WANT_IPC_PARSE_VERSION
	select CLKSRC_I8253
	select CLONE_BACKWARDS
	select HAVE_AOUT
	select HAVE_GENERIC_DMA_COHERENT
	select MODULES_USE_ELF_REL
	select OLD_SIGACTION
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config X86_64
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	def_bool y
	depends on 64BIT
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	# Options that are inherently 64-bit kernel only:
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	select ARCH_HAS_GIGANTIC_PAGE if (MEMORY_ISOLATION && COMPACTION) || CMA
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	select ARCH_SUPPORTS_INT128
	select ARCH_USE_CMPXCHG_LOCKREF
	select HAVE_ARCH_SOFT_DIRTY
	select MODULES_USE_ELF_RELA
	select X86_DEV_DMA_OPS
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#
# Arch settings
#
# ( Note that options that are marked 'if X86_64' could in principle be
#   ported to 32-bit as well. )
#
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config X86
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	def_bool y
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	#
	# Note: keep this list sorted alphabetically
	#
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	select ACPI_LEGACY_TABLES_LOOKUP	if ACPI
	select ACPI_SYSTEM_POWER_STATES_SUPPORT	if ACPI
	select ANON_INODES
	select ARCH_CLOCKSOURCE_DATA
	select ARCH_DISCARD_MEMBLOCK
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	select ARCH_HAS_ACPI_TABLE_UPGRADE	if ACPI
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	select ARCH_HAS_DEBUG_VIRTUAL
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	select ARCH_HAS_DEVMEM_IS_ALLOWED
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	select ARCH_HAS_ELF_RANDOMIZE
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	select ARCH_HAS_FAST_MULTIPLIER
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	select ARCH_HAS_FORTIFY_SOURCE
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	select ARCH_HAS_GCOV_PROFILE_ALL
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	select ARCH_HAS_KCOV			if X86_64
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	select ARCH_HAS_PMEM_API		if X86_64
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	# Causing hangs/crashes, see the commit that added this change for details.
	select ARCH_HAS_REFCOUNT		if BROKEN
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	select ARCH_HAS_UACCESS_FLUSHCACHE	if X86_64
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	select ARCH_HAS_SET_MEMORY
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	select ARCH_HAS_SG_CHAIN
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	select ARCH_HAS_STRICT_KERNEL_RWX
	select ARCH_HAS_STRICT_MODULE_RWX
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	select ARCH_HAS_UBSAN_SANITIZE_ALL
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	select ARCH_HAS_ZONE_DEVICE		if X86_64
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	select ARCH_HAVE_NMI_SAFE_CMPXCHG
	select ARCH_MIGHT_HAVE_ACPI_PDC		if ACPI
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	select ARCH_MIGHT_HAVE_PC_PARPORT
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	select ARCH_MIGHT_HAVE_PC_SERIO
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	select ARCH_SUPPORTS_ATOMIC_RMW
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	select ARCH_SUPPORTS_DEFERRED_STRUCT_PAGE_INIT
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	select ARCH_SUPPORTS_NUMA_BALANCING	if X86_64
	select ARCH_USE_BUILTIN_BSWAP
	select ARCH_USE_QUEUED_RWLOCKS
	select ARCH_USE_QUEUED_SPINLOCKS
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	select ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH
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	select ARCH_WANTS_DYNAMIC_TASK_STRUCT
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	select ARCH_WANTS_THP_SWAP		if X86_64
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	select BUILDTIME_EXTABLE_SORT
	select CLKEVT_I8253
	select CLOCKSOURCE_VALIDATE_LAST_CYCLE
	select CLOCKSOURCE_WATCHDOG
	select DCACHE_WORD_ACCESS
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	select EDAC_ATOMIC_SCRUB
	select EDAC_SUPPORT
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	select GENERIC_CLOCKEVENTS
	select GENERIC_CLOCKEVENTS_BROADCAST	if X86_64 || (X86_32 && X86_LOCAL_APIC)
	select GENERIC_CLOCKEVENTS_MIN_ADJUST
	select GENERIC_CMOS_UPDATE
	select GENERIC_CPU_AUTOPROBE
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	select GENERIC_CPU_VULNERABILITIES
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	select GENERIC_EARLY_IOREMAP
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	select GENERIC_FIND_FIRST_BIT
	select GENERIC_IOMAP
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	select GENERIC_IRQ_EFFECTIVE_AFF_MASK	if SMP
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	select GENERIC_IRQ_MIGRATION		if SMP
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	select GENERIC_IRQ_PROBE
	select GENERIC_IRQ_SHOW
	select GENERIC_PENDING_IRQ		if SMP
	select GENERIC_SMP_IDLE_THREAD
	select GENERIC_STRNCPY_FROM_USER
	select GENERIC_STRNLEN_USER
	select GENERIC_TIME_VSYSCALL
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	select HARDLOCKUP_CHECK_TIMESTAMP	if X86_64
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	select HAVE_ACPI_APEI			if ACPI
	select HAVE_ACPI_APEI_NMI		if ACPI
	select HAVE_ALIGNED_STRUCT_PAGE		if SLUB
	select HAVE_ARCH_AUDITSYSCALL
	select HAVE_ARCH_HUGE_VMAP		if X86_64 || X86_PAE
	select HAVE_ARCH_JUMP_LABEL
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	select HAVE_ARCH_KASAN			if X86_64
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	select HAVE_ARCH_KGDB
	select HAVE_ARCH_KMEMCHECK
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	select HAVE_ARCH_MMAP_RND_BITS		if MMU
	select HAVE_ARCH_MMAP_RND_COMPAT_BITS	if MMU && COMPAT
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	select HAVE_ARCH_COMPAT_MMAP_BASES	if MMU && COMPAT
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	select HAVE_ARCH_SECCOMP_FILTER
	select HAVE_ARCH_TRACEHOOK
	select HAVE_ARCH_TRANSPARENT_HUGEPAGE
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	select HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD if X86_64
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	select HAVE_ARCH_VMAP_STACK		if X86_64
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	select HAVE_ARCH_WITHIN_STACK_FRAMES
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	select HAVE_CC_STACKPROTECTOR
	select HAVE_CMPXCHG_DOUBLE
	select HAVE_CMPXCHG_LOCAL
	select HAVE_CONTEXT_TRACKING		if X86_64
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	select HAVE_COPY_THREAD_TLS
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	select HAVE_C_RECORDMCOUNT
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	select HAVE_DEBUG_KMEMLEAK
	select HAVE_DEBUG_STACKOVERFLOW
	select HAVE_DMA_API_DEBUG
	select HAVE_DMA_CONTIGUOUS
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	select HAVE_DYNAMIC_FTRACE
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	select HAVE_DYNAMIC_FTRACE_WITH_REGS
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	select HAVE_EBPF_JIT			if X86_64
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	select HAVE_EFFICIENT_UNALIGNED_ACCESS
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	select HAVE_EXIT_THREAD
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	select HAVE_FENTRY			if X86_64 || DYNAMIC_FTRACE
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	select HAVE_FTRACE_MCOUNT_RECORD
	select HAVE_FUNCTION_GRAPH_TRACER
	select HAVE_FUNCTION_TRACER
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	select HAVE_GCC_PLUGINS
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	select HAVE_HW_BREAKPOINT
	select HAVE_IDE
	select HAVE_IOREMAP_PROT
	select HAVE_IRQ_EXIT_ON_IRQ_STACK	if X86_64
	select HAVE_IRQ_TIME_ACCOUNTING
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	select HAVE_KERNEL_BZIP2
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	select HAVE_KERNEL_GZIP
	select HAVE_KERNEL_LZ4
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	select HAVE_KERNEL_LZMA
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	select HAVE_KERNEL_LZO
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	select HAVE_KERNEL_XZ
	select HAVE_KPROBES
	select HAVE_KPROBES_ON_FTRACE
	select HAVE_KRETPROBES
	select HAVE_KVM
	select HAVE_LIVEPATCH			if X86_64
	select HAVE_MEMBLOCK
	select HAVE_MEMBLOCK_NODE_MAP
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	select HAVE_MIXED_BREAKPOINTS_REGS
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	select HAVE_MOD_ARCH_SPECIFIC
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	select HAVE_NMI
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	select HAVE_OPROFILE
	select HAVE_OPTPROBES
	select HAVE_PCSPKR_PLATFORM
	select HAVE_PERF_EVENTS
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	select HAVE_PERF_EVENTS_NMI
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	select HAVE_HARDLOCKUP_DETECTOR_PERF	if PERF_EVENTS && HAVE_PERF_EVENTS_NMI
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	select HAVE_PERF_REGS
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	select HAVE_PERF_USER_STACK_DUMP
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	select HAVE_RCU_TABLE_FREE
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	select HAVE_REGS_AND_STACK_ACCESS_API
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	select HAVE_RELIABLE_STACKTRACE		if X86_64 && UNWINDER_FRAME_POINTER && STACK_VALIDATION
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	select HAVE_STACK_VALIDATION		if X86_64
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	select HAVE_SYSCALL_TRACEPOINTS
	select HAVE_UNSTABLE_SCHED_CLOCK
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	select HAVE_USER_RETURN_NOTIFIER
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	select IRQ_FORCED_THREADING
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	select PCI_LOCKLESS_CONFIG
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	select PERF_EVENTS
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	select RTC_LIB
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	select RTC_MC146818_LIB
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	select SPARSE_IRQ
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	select SRCU
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	select SYSCTL_EXCEPTION_TRACE
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	select THREAD_INFO_IN_TASK
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	select USER_STACKTRACE_SUPPORT
	select VIRT_TO_BUS
	select X86_FEATURE_NAMES		if PROC_FS
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config INSTRUCTION_DECODER
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	def_bool y
	depends on KPROBES || PERF_EVENTS || UPROBES
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config OUTPUT_FORMAT
	string
	default "elf32-i386" if X86_32
	default "elf64-x86-64" if X86_64

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config ARCH_DEFCONFIG
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	string
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	default "arch/x86/configs/i386_defconfig" if X86_32
	default "arch/x86/configs/x86_64_defconfig" if X86_64
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config LOCKDEP_SUPPORT
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	def_bool y
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config STACKTRACE_SUPPORT
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	def_bool y
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config MMU
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	def_bool y
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config ARCH_MMAP_RND_BITS_MIN
	default 28 if 64BIT
	default 8

config ARCH_MMAP_RND_BITS_MAX
	default 32 if 64BIT
	default 16

config ARCH_MMAP_RND_COMPAT_BITS_MIN
	default 8

config ARCH_MMAP_RND_COMPAT_BITS_MAX
	default 16

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config SBUS
	bool

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config NEED_DMA_MAP_STATE
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	def_bool y
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	depends on X86_64 || INTEL_IOMMU || DMA_API_DEBUG || SWIOTLB
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config NEED_SG_DMA_LENGTH
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	def_bool y
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config GENERIC_ISA_DMA
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	def_bool y
	depends on ISA_DMA_API
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config GENERIC_BUG
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	def_bool y
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	depends on BUG
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	select GENERIC_BUG_RELATIVE_POINTERS if X86_64

config GENERIC_BUG_RELATIVE_POINTERS
	bool
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config GENERIC_HWEIGHT
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	def_bool y
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config ARCH_MAY_HAVE_PC_FDC
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	def_bool y
	depends on ISA_DMA_API
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config RWSEM_XCHGADD_ALGORITHM
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	def_bool y
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config GENERIC_CALIBRATE_DELAY
	def_bool y

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config ARCH_HAS_CPU_RELAX
	def_bool y

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config ARCH_HAS_CACHE_LINE_SIZE
	def_bool y

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config HAVE_SETUP_PER_CPU_AREA
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	def_bool y
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config NEED_PER_CPU_EMBED_FIRST_CHUNK
	def_bool y

config NEED_PER_CPU_PAGE_FIRST_CHUNK
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	def_bool y

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config ARCH_HIBERNATION_POSSIBLE
	def_bool y

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config ARCH_SUSPEND_POSSIBLE
	def_bool y

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config ARCH_WANT_HUGE_PMD_SHARE
	def_bool y

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config ARCH_WANT_GENERAL_HUGETLB
	def_bool y

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config ZONE_DMA32
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	def_bool y if X86_64
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config AUDIT_ARCH
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	def_bool y if X86_64
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config ARCH_SUPPORTS_OPTIMIZED_INLINING
	def_bool y

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config ARCH_SUPPORTS_DEBUG_PAGEALLOC
	def_bool y

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config KASAN_SHADOW_OFFSET
	hex
	depends on KASAN
	default 0xdffffc0000000000

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config HAVE_INTEL_TXT
	def_bool y
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	depends on INTEL_IOMMU && ACPI
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config X86_32_SMP
	def_bool y
	depends on X86_32 && SMP

config X86_64_SMP
	def_bool y
	depends on X86_64 && SMP

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config X86_32_LAZY_GS
	def_bool y
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	depends on X86_32 && !CC_STACKPROTECTOR
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config ARCH_SUPPORTS_UPROBES
	def_bool y

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config FIX_EARLYCON_MEM
	def_bool y

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config PGTABLE_LEVELS
	int
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	default 5 if X86_5LEVEL
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	default 4 if X86_64
	default 3 if X86_PAE
	default 2

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source "init/Kconfig"
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source "kernel/Kconfig.freezer"
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menu "Processor type and features"

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config ZONE_DMA
	bool "DMA memory allocation support" if EXPERT
	default y
	help
	  DMA memory allocation support allows devices with less than 32-bit
	  addressing to allocate within the first 16MB of address space.
	  Disable if no such devices will be used.

	  If unsure, say Y.

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config SMP
	bool "Symmetric multi-processing support"
	---help---
	  This enables support for systems with more than one CPU. If you have
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	  a system with only one CPU, say N. If you have a system with more
	  than one CPU, say Y.
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	  If you say N here, the kernel will run on uni- and multiprocessor
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	  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,
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	  uniprocessor machines. On a uniprocessor machine, the kernel
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	  will run faster if you say N here.

	  Note that if you say Y here and choose architecture "586" or
	  "Pentium" under "Processor family", the kernel will not work on 486
	  architectures. Similarly, multiprocessor kernels for the "PPro"
	  architecture may not work on all Pentium based boards.

	  People using multiprocessor machines who say Y here should also say
	  Y to "Enhanced Real Time Clock Support", below. The "Advanced Power
	  Management" code will be disabled if you say Y here.

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	  See also <file:Documentation/x86/i386/IO-APIC.txt>,
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	  <file:Documentation/lockup-watchdogs.txt> and the SMP-HOWTO available at
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	  <http://www.tldp.org/docs.html#howto>.

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

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config X86_FEATURE_NAMES
	bool "Processor feature human-readable names" if EMBEDDED
	default y
	---help---
	  This option compiles in a table of x86 feature bits and corresponding
	  names.  This is required to support /proc/cpuinfo and a few kernel
	  messages.  You can disable this to save space, at the expense of
	  making those few kernel messages show numeric feature bits instead.

	  If in doubt, say Y.

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config X86_FAST_FEATURE_TESTS
	bool "Fast CPU feature tests" if EMBEDDED
	default y
	---help---
	  Some fast-paths in the kernel depend on the capabilities of the CPU.
	  Say Y here for the kernel to patch in the appropriate code at runtime
	  based on the capabilities of the CPU. The infrastructure for patching
	  code at runtime takes up some additional space; space-constrained
	  embedded systems may wish to say N here to produce smaller, slightly
	  slower code.

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config X86_X2APIC
	bool "Support x2apic"
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	depends on X86_LOCAL_APIC && X86_64 && (IRQ_REMAP || HYPERVISOR_GUEST)
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	---help---
	  This enables x2apic support on CPUs that have this feature.

	  This allows 32-bit apic IDs (so it can support very large systems),
	  and accesses the local apic via MSRs not via mmio.

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

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config X86_MPPARSE
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	bool "Enable MPS table" if ACPI || SFI
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	default y
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	depends on X86_LOCAL_APIC
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	---help---
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	  For old smp systems that do not have proper acpi support. Newer systems
	  (esp with 64bit cpus) with acpi support, MADT and DSDT will override it

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config X86_BIGSMP
	bool "Support for big SMP systems with more than 8 CPUs"
	depends on X86_32 && SMP
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	---help---
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	  This option is needed for the systems that have more than 8 CPUs
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config GOLDFISH
       def_bool y
       depends on X86_GOLDFISH

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config INTEL_RDT
	bool "Intel Resource Director Technology support"
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	default n
	depends on X86 && CPU_SUP_INTEL
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	select KERNFS
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	help
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	  Select to enable resource allocation and monitoring which are
	  sub-features of Intel Resource Director Technology(RDT). More
	  information about RDT can be found in the Intel x86
	  Architecture Software Developer Manual.
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	  Say N if unsure.

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if X86_32
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config X86_EXTENDED_PLATFORM
	bool "Support for extended (non-PC) x86 platforms"
	default y
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	---help---
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	  If you disable this option then the kernel will only support
	  standard PC platforms. (which covers the vast majority of
	  systems out there.)

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	  If you enable this option then you'll be able to select support
	  for the following (non-PC) 32 bit x86 platforms:
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		Goldfish (Android emulator)
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		AMD Elan
		RDC R-321x SoC
		SGI 320/540 (Visual Workstation)
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		STA2X11-based (e.g. Northville)
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		Moorestown MID devices
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	  If you have one of these systems, or if you want to build a
	  generic distribution kernel, say Y here - otherwise say N.
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endif
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if X86_64
config X86_EXTENDED_PLATFORM
	bool "Support for extended (non-PC) x86 platforms"
	default y
	---help---
	  If you disable this option then the kernel will only support
	  standard PC platforms. (which covers the vast majority of
	  systems out there.)

	  If you enable this option then you'll be able to select support
	  for the following (non-PC) 64 bit x86 platforms:
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		Numascale NumaChip
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		ScaleMP vSMP
		SGI Ultraviolet

	  If you have one of these systems, or if you want to build a
	  generic distribution kernel, say Y here - otherwise say N.
endif
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# This is an alphabetically sorted list of 64 bit extended platforms
# Please maintain the alphabetic order if and when there are additions
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config X86_NUMACHIP
	bool "Numascale NumaChip"
	depends on X86_64
	depends on X86_EXTENDED_PLATFORM
	depends on NUMA
	depends on SMP
	depends on X86_X2APIC
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	depends on PCI_MMCONFIG
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	---help---
	  Adds support for Numascale NumaChip large-SMP systems. Needed to
	  enable more than ~168 cores.
	  If you don't have one of these, you should say N here.
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config X86_VSMP
	bool "ScaleMP vSMP"
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	select HYPERVISOR_GUEST
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	select PARAVIRT
	depends on X86_64 && PCI
	depends on X86_EXTENDED_PLATFORM
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	depends on SMP
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	---help---
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	  Support for ScaleMP vSMP systems.  Say 'Y' here if this kernel is
	  supposed to run on these EM64T-based machines.  Only choose this option
	  if you have one of these machines.
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config X86_UV
	bool "SGI Ultraviolet"
	depends on X86_64
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	depends on X86_EXTENDED_PLATFORM
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	depends on NUMA
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	depends on EFI
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	depends on X86_X2APIC
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	depends on PCI
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	---help---
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	  This option is needed in order to support SGI Ultraviolet systems.
	  If you don't have one of these, you should say N here.

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# Following is an alphabetically sorted list of 32 bit extended platforms
# Please maintain the alphabetic order if and when there are additions
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config X86_GOLDFISH
       bool "Goldfish (Virtual Platform)"
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       depends on X86_EXTENDED_PLATFORM
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       ---help---
	 Enable support for the Goldfish virtual platform used primarily
	 for Android development. Unless you are building for the Android
	 Goldfish emulator say N here.

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config X86_INTEL_CE
	bool "CE4100 TV platform"
	depends on PCI
	depends on PCI_GODIRECT
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	depends on X86_IO_APIC
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	depends on X86_32
	depends on X86_EXTENDED_PLATFORM
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	select X86_REBOOTFIXUPS
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	select OF
	select OF_EARLY_FLATTREE
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	---help---
	  Select for the Intel CE media processor (CE4100) SOC.
	  This option compiles in support for the CE4100 SOC for settop
	  boxes and media devices.

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config X86_INTEL_MID
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	bool "Intel MID platform support"
	depends on X86_EXTENDED_PLATFORM
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	depends on X86_PLATFORM_DEVICES
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	depends on PCI
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	depends on X86_64 || (PCI_GOANY && X86_32)
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	depends on X86_IO_APIC
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	select SFI
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	select I2C
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	select DW_APB_TIMER
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	select APB_TIMER
	select INTEL_SCU_IPC
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	select MFD_INTEL_MSIC
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	---help---
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	  Select to build a kernel capable of supporting Intel MID (Mobile
	  Internet Device) platform systems which do not have the PCI legacy
	  interfaces. If you are building for a PC class system say N here.
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	  Intel MID platforms are based on an Intel processor and chipset which
	  consume less power than most of the x86 derivatives.
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config X86_INTEL_QUARK
	bool "Intel Quark platform support"
	depends on X86_32
	depends on X86_EXTENDED_PLATFORM
	depends on X86_PLATFORM_DEVICES
	depends on X86_TSC
	depends on PCI
	depends on PCI_GOANY
	depends on X86_IO_APIC
	select IOSF_MBI
	select INTEL_IMR
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	select COMMON_CLK
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	---help---
	  Select to include support for Quark X1000 SoC.
	  Say Y here if you have a Quark based system such as the Arduino
	  compatible Intel Galileo.

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config X86_INTEL_LPSS
	bool "Intel Low Power Subsystem Support"
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	depends on X86 && ACPI
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	select COMMON_CLK
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	select PINCTRL
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	select IOSF_MBI
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	---help---
	  Select to build support for Intel Low Power Subsystem such as
	  found on Intel Lynxpoint PCH. Selecting this option enables
597 598
	  things like clock tree (common clock framework) and pincontrol
	  which are needed by the LPSS peripheral drivers.
599

600 601 602 603 604 605 606 607 608 609 610
config X86_AMD_PLATFORM_DEVICE
	bool "AMD ACPI2Platform devices support"
	depends on ACPI
	select COMMON_CLK
	select PINCTRL
	---help---
	  Select to interpret AMD specific ACPI device to platform device
	  such as I2C, UART, GPIO found on AMD Carrizo and later chipsets.
	  I2C and UART depend on COMMON_CLK to set clock. GPIO driver is
	  implemented under PINCTRL subsystem.

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config IOSF_MBI
	tristate "Intel SoC IOSF Sideband support for SoC platforms"
	depends on PCI
	---help---
	  This option enables sideband register access support for Intel SoC
	  platforms. On these platforms the IOSF sideband is used in lieu of
	  MSR's for some register accesses, mostly but not limited to thermal
	  and power. Drivers may query the availability of this device to
	  determine if they need the sideband in order to work on these
	  platforms. The sideband is available on the following SoC products.
	  This list is not meant to be exclusive.
	   - BayTrail
	   - Braswell
	   - Quark

	  You should say Y if you are running a kernel on one of these SoC's.

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config IOSF_MBI_DEBUG
	bool "Enable IOSF sideband access through debugfs"
	depends on IOSF_MBI && DEBUG_FS
	---help---
	  Select this option to expose the IOSF sideband access registers (MCR,
	  MDR, MCRX) through debugfs to write and read register information from
	  different units on the SoC. This is most useful for obtaining device
	  state information for debug and analysis. As this is a general access
	  mechanism, users of this option would have specific knowledge of the
	  device they want to access.

	  If you don't require the option or are in doubt, say N.

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config X86_RDC321X
	bool "RDC R-321x SoC"
643
	depends on X86_32
644 645 646 647 648 649 650 651
	depends on X86_EXTENDED_PLATFORM
	select M486
	select X86_REBOOTFIXUPS
	---help---
	  This option is needed for RDC R-321x system-on-chip, also known
	  as R-8610-(G).
	  If you don't have one of these chips, you should say N here.

652
config X86_32_NON_STANDARD
653 654
	bool "Support non-standard 32-bit SMP architectures"
	depends on X86_32 && SMP
655
	depends on X86_EXTENDED_PLATFORM
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	---help---
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	  This option compiles in the bigsmp and STA2X11 default
	  subarchitectures.  It is intended for a generic binary
	  kernel. If you select them all, kernel will probe it one by
	  one and will fallback to default.
661

662
# Alphabetically sorted list of Non standard 32 bit platforms
663

664
config X86_SUPPORTS_MEMORY_FAILURE
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	def_bool y
666 667 668 669 670 671 672
	# MCE code calls memory_failure():
	depends on X86_MCE
	# On 32-bit this adds too big of NODES_SHIFT and we run out of page flags:
	# On 32-bit SPARSEMEM adds too big of SECTIONS_WIDTH:
	depends on X86_64 || !SPARSEMEM
	select ARCH_SUPPORTS_MEMORY_FAILURE

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config STA2X11
	bool "STA2X11 Companion Chip Support"
	depends on X86_32_NON_STANDARD && PCI
	select X86_DEV_DMA_OPS
	select X86_DMA_REMAP
	select SWIOTLB
	select MFD_STA2X11
680
	select GPIOLIB
681 682 683 684 685 686 687 688
	default n
	---help---
	  This adds support for boards based on the STA2X11 IO-Hub,
	  a.k.a. "ConneXt". The chip is used in place of the standard
	  PC chipset, so all "standard" peripherals are missing. If this
	  option is selected the kernel will still be able to boot on
	  standard PC machines.

689 690 691 692 693 694 695 696 697 698 699 700 701
config X86_32_IRIS
	tristate "Eurobraille/Iris poweroff module"
	depends on X86_32
	---help---
	  The Iris machines from EuroBraille do not have APM or ACPI support
	  to shut themselves down properly.  A special I/O sequence is
	  needed to do so, which is what this module does at
	  kernel shutdown.

	  This is only for Iris machines from EuroBraille.

	  If unused, say N.

702
config SCHED_OMIT_FRAME_POINTER
703 704
	def_bool y
	prompt "Single-depth WCHAN output"
705
	depends on X86
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	---help---
707 708 709 710 711 712 713
	  Calculate simpler /proc/<PID>/wchan values. If this option
	  is disabled then wchan values will recurse back to the
	  caller function. This provides more accurate wchan values,
	  at the expense of slightly more scheduling overhead.

	  If in doubt, say "Y".

714 715
menuconfig HYPERVISOR_GUEST
	bool "Linux guest support"
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	---help---
717 718 719
	  Say Y here to enable options for running Linux under various hyper-
	  visors. This option enables basic hypervisor detection and platform
	  setup.
720

721 722
	  If you say N, all options in this submenu will be skipped and
	  disabled, and Linux guest support won't be built in.
723

724
if HYPERVISOR_GUEST
725

726 727
config PARAVIRT
	bool "Enable paravirtualization code"
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	---help---
729 730 731 732 733
	  This changes the kernel so it can modify itself when it is run
	  under a hypervisor, potentially improving performance significantly
	  over full virtualization.  However, when run without a hypervisor
	  the kernel is theoretically slower and slightly larger.

734 735 736 737 738 739 740
config PARAVIRT_DEBUG
	bool "paravirt-ops debugging"
	depends on PARAVIRT && DEBUG_KERNEL
	---help---
	  Enable to debug paravirt_ops internals.  Specifically, BUG if
	  a paravirt_op is missing when it is called.

741 742
config PARAVIRT_SPINLOCKS
	bool "Paravirtualization layer for spinlocks"
743
	depends on PARAVIRT && SMP
744 745 746 747 748
	---help---
	  Paravirtualized spinlocks allow a pvops backend to replace the
	  spinlock implementation with something virtualization-friendly
	  (for example, block the virtual CPU rather than spinning).

749 750
	  It has a minimal impact on native kernels and gives a nice performance
	  benefit on paravirtualized KVM / Xen kernels.
751

752
	  If you are unsure how to answer this question, answer Y.
753

754 755
config QUEUED_LOCK_STAT
	bool "Paravirt queued spinlock statistics"
756
	depends on PARAVIRT_SPINLOCKS && DEBUG_FS
757 758 759 760 761
	---help---
	  Enable the collection of statistical data on the slowpath
	  behavior of paravirtualized queued spinlocks and report
	  them on debugfs.

762
source "arch/x86/xen/Kconfig"
763

764 765 766 767 768
config KVM_GUEST
	bool "KVM Guest support (including kvmclock)"
	depends on PARAVIRT
	select PARAVIRT_CLOCK
	default y
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	---help---
770 771 772 773 774
	  This option enables various optimizations for running under the KVM
	  hypervisor. It includes a paravirtualized clock, so that instead
	  of relying on a PIT (or probably other) emulation by the
	  underlying device model, the host provides the guest with
	  timing infrastructure such as time of day, and system time
775

776 777 778 779 780 781 782 783 784
config KVM_DEBUG_FS
	bool "Enable debug information for KVM Guests in debugfs"
	depends on KVM_GUEST && DEBUG_FS
	default n
	---help---
	  This option enables collection of various statistics for KVM guest.
	  Statistics are displayed in debugfs filesystem. Enabling this option
	  may incur significant overhead.

785 786 787 788
config PARAVIRT_TIME_ACCOUNTING
	bool "Paravirtual steal time accounting"
	depends on PARAVIRT
	default n
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	---help---
790 791 792 793 794 795 796 797 798
	  Select this option to enable fine granularity task steal time
	  accounting. Time spent executing other tasks in parallel with
	  the current vCPU is discounted from the vCPU power. To account for
	  that, there can be a small performance impact.

	  If in doubt, say N here.

config PARAVIRT_CLOCK
	bool
799

800
endif #HYPERVISOR_GUEST
801

802
config NO_BOOTMEM
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	def_bool y
804

805 806 807
source "arch/x86/Kconfig.cpu"

config HPET_TIMER
808
	def_bool X86_64
809
	prompt "HPET Timer Support" if X86_32
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	---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.
	  HPET is the next generation timer replacing legacy 8254s.
	  The HPET provides a stable time base on SMP
	  systems, unlike the TSC, but it is more expensive to access,
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	  as it is off-chip.  The interface used is documented
	  in the HPET spec, revision 1.
819

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	  You can safely choose Y here.  However, HPET will only be
	  activated if the platform and the BIOS support this feature.
	  Otherwise the 8254 will be used for timing services.
823

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	  Choose N to continue using the legacy 8254 timer.
825 826

config HPET_EMULATE_RTC
827
	def_bool y
828
	depends on HPET_TIMER && (RTC=y || RTC=m || RTC_DRV_CMOS=m || RTC_DRV_CMOS=y)
829

830
config APB_TIMER
831 832
       def_bool y if X86_INTEL_MID
       prompt "Intel MID APB Timer Support" if X86_INTEL_MID
833
       select DW_APB_TIMER
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       depends on X86_INTEL_MID && SFI
835 836 837 838 839 840 841
       help
         APB timer is the replacement for 8254, HPET on X86 MID platforms.
         The APBT provides a stable time base on SMP
         systems, unlike the TSC, but it is more expensive to access,
         as it is off-chip. APB timers are always running regardless of CPU
         C states, they are used as per CPU clockevent device when possible.

842
# Mark as expert because too many people got it wrong.
843
# The code disables itself when not needed.
844 845
config DMI
	default y
846
	select DMI_SCAN_MACHINE_NON_EFI_FALLBACK
847
	bool "Enable DMI scanning" if EXPERT
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	---help---
849 850 851 852 853
	  Enabled scanning of DMI to identify machine quirks. Say Y
	  here unless you have verified that your setup is not
	  affected by entries in the DMI blacklist. Required by PNP
	  BIOS code.

854
config GART_IOMMU
855
	bool "Old AMD GART IOMMU support"
856
	select SWIOTLB
857
	depends on X86_64 && PCI && AMD_NB
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	---help---
859 860 861 862 863 864 865 866 867 868 869 870 871 872 873
	  Provides a driver for older AMD Athlon64/Opteron/Turion/Sempron
	  GART based hardware IOMMUs.

	  The GART supports full DMA access for devices with 32-bit access
	  limitations, on systems with more than 3 GB. This is usually needed
	  for USB, sound, many IDE/SATA chipsets and some other devices.

	  Newer systems typically have a modern AMD IOMMU, supported via
	  the CONFIG_AMD_IOMMU=y config option.

	  In normal configurations this driver is only active when needed:
	  there's more than 3 GB of memory and the system contains a
	  32-bit limited device.

	  If unsure, say Y.
874 875 876 877

config CALGARY_IOMMU
	bool "IBM Calgary IOMMU support"
	select SWIOTLB
878
	depends on X86_64 && PCI
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	---help---
880 881 882 883 884 885 886 887 888 889 890 891 892 893
	  Support for hardware IOMMUs in IBM's xSeries x366 and x460
	  systems. Needed to run systems with more than 3GB of memory
	  properly with 32-bit PCI devices that do not support DAC
	  (Double Address Cycle). Calgary also supports bus level
	  isolation, where all DMAs pass through the IOMMU.  This
	  prevents them from going anywhere except their intended
	  destination. This catches hard-to-find kernel bugs and
	  mis-behaving drivers and devices that do not use the DMA-API
	  properly to set up their DMA buffers.  The IOMMU can be
	  turned off at boot time with the iommu=off parameter.
	  Normally the kernel will make the right choice by itself.
	  If unsure, say Y.

config CALGARY_IOMMU_ENABLED_BY_DEFAULT
894 895
	def_bool y
	prompt "Should Calgary be enabled by default?"
896
	depends on CALGARY_IOMMU
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	---help---
898 899 900 901 902 903 904 905
	  Should Calgary be enabled by default? if you choose 'y', Calgary
	  will be used (if it exists). If you choose 'n', Calgary will not be
	  used even if it exists. If you choose 'n' and would like to use
	  Calgary anyway, pass 'iommu=calgary' on the kernel command line.
	  If unsure, say Y.

# need this always selected by IOMMU for the VIA workaround
config SWIOTLB
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	def_bool y if X86_64
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	---help---
908
	  Support for software bounce buffers used on x86-64 systems
909 910 911 912
	  which don't have a hardware IOMMU. Using this PCI devices
	  which can only access 32-bits of memory can be used on systems
	  with more than 3 GB of memory.
	  If unsure, say Y.
913

914
config IOMMU_HELPER
915 916
	def_bool y
	depends on CALGARY_IOMMU || GART_IOMMU || SWIOTLB || AMD_IOMMU
917

918
config MAXSMP
919
	bool "Enable Maximum number of SMP Processors and NUMA Nodes"
920
	depends on X86_64 && SMP && DEBUG_KERNEL
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	select CPUMASK_OFFSTACK
I
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922
	---help---
923
	  Enable maximum number of CPUS and NUMA Nodes for this architecture.
924
	  If unsure, say N.
925 926

config NR_CPUS
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	int "Maximum number of CPUs" if SMP && !MAXSMP
928
	range 2 8 if SMP && X86_32 && !X86_BIGSMP
929 930
	range 2 64 if SMP && X86_32 && X86_BIGSMP
	range 2 512 if SMP && !MAXSMP && !CPUMASK_OFFSTACK && X86_64
931
	range 2 8192 if SMP && !MAXSMP && CPUMASK_OFFSTACK && X86_64
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	default "1" if !SMP
933
	default "8192" if MAXSMP
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934
	default "32" if SMP && X86_BIGSMP
935 936
	default "8" if SMP && X86_32
	default "64" if SMP
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	---help---
938
	  This allows you to specify the maximum number of CPUs which this
J
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939
	  kernel will support.  If CPUMASK_OFFSTACK is enabled, the maximum
940
	  supported value is 8192, otherwise the maximum value is 512.  The
941 942 943 944 945 946 947
	  minimum value which makes sense is 2.

	  This is purely to save memory - each supported CPU adds
	  approximately eight kilobytes to the kernel image.

config SCHED_SMT
	bool "SMT (Hyperthreading) scheduler support"
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948
	depends on SMP
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949
	---help---
950 951 952 953 954 955
	  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 SCHED_MC
956 957
	def_bool y
	prompt "Multi-core scheduler support"
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	depends on SMP
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	---help---
960 961 962 963
	  Multi-core scheduler support improves the CPU scheduler's decision
	  making when dealing with multi-core CPU chips at a cost of slightly
	  increased overhead in some places. If unsure say N here.

964 965
config SCHED_MC_PRIO
	bool "CPU core priorities scheduler support"
966 967 968
	depends on SCHED_MC && CPU_SUP_INTEL
	select X86_INTEL_PSTATE
	select CPU_FREQ
969
	default y
970
	---help---
971 972 973 974
	  Intel Turbo Boost Max Technology 3.0 enabled CPUs have a
	  core ordering determined at manufacturing time, which allows
	  certain cores to reach higher turbo frequencies (when running
	  single threaded workloads) than others.
975

976 977 978 979
	  Enabling this kernel feature teaches the scheduler about
	  the TBM3 (aka ITMT) priority order of the CPU cores and adjusts the
	  scheduler's CPU selection logic accordingly, so that higher
	  overall system performance can be achieved.
980

981
	  This feature will have no effect on CPUs without this feature.
982

983
	  If unsure say Y here.
984

985 986
source "kernel/Kconfig.preempt"

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config UP_LATE_INIT
       def_bool y
989
       depends on !SMP && X86_LOCAL_APIC
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991
config X86_UP_APIC
992 993
	bool "Local APIC support on uniprocessors" if !PCI_MSI
	default PCI_MSI
994
	depends on X86_32 && !SMP && !X86_32_NON_STANDARD
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	---help---
996 997 998 999 1000 1001 1002 1003 1004 1005 1006 1007
	  A local APIC (Advanced Programmable Interrupt Controller) is an
	  integrated interrupt controller in the CPU. If you have a single-CPU
	  system which has a processor with a local APIC, you can say Y here to
	  enable and use it. If you say Y here even though your machine doesn't
	  have a local APIC, then the kernel will still run with no slowdown at
	  all. The local APIC supports CPU-generated self-interrupts (timer,
	  performance counters), and the NMI watchdog which detects hard
	  lockups.

config X86_UP_IOAPIC
	bool "IO-APIC support on uniprocessors"
	depends on X86_UP_APIC
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	---help---
1009 1010 1011 1012 1013 1014 1015 1016 1017
	  An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an
	  SMP-capable replacement for PC-style interrupt controllers. Most
	  SMP systems and many recent uniprocessor systems have one.

	  If you have a single-CPU system with an IO-APIC, you can say Y here
	  to use it. If you say Y here even though your machine doesn't have
	  an IO-APIC, then the kernel will still run with no slowdown at all.

config X86_LOCAL_APIC
1018
	def_bool y
1019
	depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC || PCI_MSI
1020
	select IRQ_DOMAIN_HIERARCHY
1021
	select PCI_MSI_IRQ_DOMAIN if PCI_MSI
1022 1023

config X86_IO_APIC
1024 1025
	def_bool y
	depends on X86_LOCAL_APIC || X86_UP_IOAPIC
1026

1027 1028 1029
config X86_REROUTE_FOR_BROKEN_BOOT_IRQS
	bool "Reroute for broken boot IRQs"
	depends on X86_IO_APIC
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	---help---
1031 1032 1033 1034 1035 1036 1037 1038 1039 1040 1041 1042 1043 1044 1045 1046 1047 1048 1049
	  This option enables a workaround that fixes a source of
	  spurious interrupts. This is recommended when threaded
	  interrupt handling is used on systems where the generation of
	  superfluous "boot interrupts" cannot be disabled.

	  Some chipsets generate a legacy INTx "boot IRQ" when the IRQ
	  entry in the chipset's IO-APIC is masked (as, e.g. the RT
	  kernel does during interrupt handling). On chipsets where this
	  boot IRQ generation cannot be disabled, this workaround keeps
	  the original IRQ line masked so that only the equivalent "boot
	  IRQ" is delivered to the CPUs. The workaround also tells the
	  kernel to set up the IRQ handler on the boot IRQ line. In this
	  way only one interrupt is delivered to the kernel. Otherwise
	  the spurious second interrupt may cause the kernel to bring
	  down (vital) interrupt lines.

	  Only affects "broken" chipsets. Interrupt sharing may be
	  increased on these systems.

1050
config X86_MCE
1051
	bool "Machine Check / overheating reporting"
1052
	select GENERIC_ALLOCATOR
1053
	default y
1054
	---help---
1055 1056
	  Machine Check support allows the processor to notify the
	  kernel if it detects a problem (e.g. overheating, data corruption).
1057
	  The action the kernel takes depends on the severity of the problem,
1058
	  ranging from warning messages to halting the machine.
1059

1060 1061 1062 1063 1064 1065 1066 1067
config X86_MCELOG_LEGACY
	bool "Support for deprecated /dev/mcelog character device"
	depends on X86_MCE
	---help---
	  Enable support for /dev/mcelog which is needed by the old mcelog
	  userspace logging daemon. Consider switching to the new generation
	  rasdaemon solution.

1068
config X86_MCE_INTEL
1069 1070
	def_bool y
	prompt "Intel MCE features"
1071
	depends on X86_MCE && X86_LOCAL_APIC
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1072
	---help---
1073 1074 1075 1076
	   Additional support for intel specific MCE features such as
	   the thermal monitor.

config X86_MCE_AMD
1077 1078
	def_bool y
	prompt "AMD MCE features"
1079
	depends on X86_MCE && X86_LOCAL_APIC && AMD_NB
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	---help---
1081 1082 1083
	   Additional support for AMD specific MCE features such as
	   the DRAM Error Threshold.

1084
config X86_ANCIENT_MCE
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1085
	bool "Support for old Pentium 5 / WinChip machine checks"
1086
	depends on X86_32 && X86_MCE
1087 1088
	---help---
	  Include support for machine check handling on old Pentium 5 or WinChip
M
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1089
	  systems. These typically need to be enabled explicitly on the command
1090
	  line.
1091

1092 1093
config X86_MCE_THRESHOLD
	depends on X86_MCE_AMD || X86_MCE_INTEL
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1094
	def_bool y
1095

1096
config X86_MCE_INJECT
1097
	depends on X86_MCE && X86_LOCAL_APIC && DEBUG_FS
1098 1099 1100 1101 1102 1103
	tristate "Machine check injector support"
	---help---
	  Provide support for injecting machine checks for testing purposes.
	  If you don't know what a machine check is and you don't do kernel
	  QA it is safe to say n.

1104 1105
config X86_THERMAL_VECTOR
	def_bool y
1106
	depends on X86_MCE_INTEL
1107

1108
source "arch/x86/events/Kconfig"
1109

1110
config X86_LEGACY_VM86
1111
	bool "Legacy VM86 support"
1112
	default n
1113
	depends on X86_32
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1114
	---help---
1115 1116 1117 1118 1119 1120 1121 1122
	  This option allows user programs to put the CPU into V8086
	  mode, which is an 80286-era approximation of 16-bit real mode.

	  Some very old versions of X and/or vbetool require this option
	  for user mode setting.  Similarly, DOSEMU will use it if
	  available to accelerate real mode DOS programs.  However, any
	  recent version of DOSEMU, X, or vbetool should be fully
	  functional even without kernel VM86 support, as they will all
1123 1124 1125 1126
	  fall back to software emulation. Nevertheless, if you are using
	  a 16-bit DOS program where 16-bit performance matters, vm86
	  mode might be faster than emulation and you might want to
	  enable this option.
1127

1128 1129 1130 1131
	  Note that any app that works on a 64-bit kernel is unlikely to
	  need this option, as 64-bit kernels don't, and can't, support
	  V8086 mode. This option is also unrelated to 16-bit protected
	  mode and is not needed to run most 16-bit programs under Wine.
1132

1133 1134
	  Enabling this option increases the complexity of the kernel
	  and slows down exception handling a tiny bit.
1135

1136
	  If unsure, say N here.
1137 1138 1139 1140

config VM86
       bool
       default X86_LEGACY_VM86
1141 1142 1143 1144

config X86_16BIT
	bool "Enable support for 16-bit segments" if EXPERT
	default y
1145
	depends on MODIFY_LDT_SYSCALL
1146 1147 1148 1149 1150 1151 1152 1153 1154
	---help---
	  This option is required by programs like Wine to run 16-bit
	  protected mode legacy code on x86 processors.  Disabling
	  this option saves about 300 bytes on i386, or around 6K text
	  plus 16K runtime memory on x86-64,

config X86_ESPFIX32
	def_bool y
	depends on X86_16BIT && X86_32
1155

1156 1157
config X86_ESPFIX64
	def_bool y
1158
	depends on X86_16BIT && X86_64
1159

1160 1161 1162 1163 1164 1165 1166 1167 1168 1169 1170 1171 1172 1173 1174 1175 1176 1177
config X86_VSYSCALL_EMULATION
       bool "Enable vsyscall emulation" if EXPERT
       default y
       depends on X86_64
       ---help---
	 This enables emulation of the legacy vsyscall page.  Disabling
	 it is roughly equivalent to booting with vsyscall=none, except
	 that it will also disable the helpful warning if a program
	 tries to use a vsyscall.  With this option set to N, offending
	 programs will just segfault, citing addresses of the form
	 0xffffffffff600?00.

	 This option is required by many programs built before 2013, and
	 care should be used even with newer programs if set to N.

	 Disabling this option saves about 7K of kernel size and
	 possibly 4K of additional runtime pagetable memory.

1178 1179 1180 1181 1182 1183 1184 1185 1186 1187 1188 1189 1190 1191 1192 1193 1194
config TOSHIBA
	tristate "Toshiba Laptop support"
	depends on X86_32
	---help---
	  This adds a driver to safely access the System Management Mode of
	  the CPU on Toshiba portables with a genuine Toshiba BIOS. It does
	  not work on models with a Phoenix BIOS. The System Management Mode
	  is used to set the BIOS and power saving options on Toshiba portables.

	  For information on utilities to make use of this driver see the
	  Toshiba Linux utilities web site at:
	  <http://www.buzzard.org.uk/toshiba/>.

	  Say Y if you intend to run this kernel on a Toshiba portable.
	  Say N otherwise.

config I8K
1195
	tristate "Dell i8k legacy laptop support"
1196
	select HWMON
1197
	select SENSORS_DELL_SMM
1198
	---help---
1199 1200 1201 1202 1203 1204 1205 1206 1207
	  This option enables legacy /proc/i8k userspace interface in hwmon
	  dell-smm-hwmon driver. Character file /proc/i8k reports bios version,
	  temperature and allows controlling fan speeds of Dell laptops via
	  System Management Mode. For old Dell laptops (like Dell Inspiron 8000)
	  it reports also power and hotkey status. For fan speed control is
	  needed userspace package i8kutils.

	  Say Y if you intend to run this kernel on old Dell laptops or want to
	  use userspace package i8kutils.
1208 1209 1210
	  Say N otherwise.

config X86_REBOOTFIXUPS
1211 1212
	bool "Enable X86 board specific fixups for reboot"
	depends on X86_32
1213 1214 1215 1216 1217 1218 1219 1220
	---help---
	  This enables chipset and/or board specific fixups to be done
	  in order to get reboot to work correctly. This is only needed on
	  some combinations of hardware and BIOS. The symptom, for which
	  this config is intended, is when reboot ends with a stalled/hung
	  system.

	  Currently, the only fixup is for the Geode machines using
1221
	  CS5530A and CS5536 chipsets and the RDC R-321x SoC.
1222 1223 1224 1225 1226 1227

	  Say Y if you want to enable the fixup. Currently, it's safe to
	  enable this option even if you don't need it.
	  Say N otherwise.

config MICROCODE
1228 1229
	bool "CPU microcode loading support"
	default y
1230
	depends on CPU_SUP_AMD || CPU_SUP_INTEL
1231 1232 1233
	select FW_LOADER
	---help---
	  If you say Y here, you will be able to update the microcode on
1234 1235 1236 1237 1238 1239 1240 1241 1242 1243 1244 1245 1246 1247
	  Intel and AMD processors. The Intel support is for the IA32 family,
	  e.g. Pentium Pro, Pentium II, Pentium III, Pentium 4, Xeon etc. The
	  AMD support is for families 0x10 and later. You will obviously need
	  the actual microcode binary data itself which is not shipped with
	  the Linux kernel.

	  The preferred method to load microcode from a detached initrd is described
	  in Documentation/x86/early-microcode.txt. For that you need to enable
	  CONFIG_BLK_DEV_INITRD in order for the loader to be able to scan the
	  initrd for microcode blobs.

	  In addition, you can build-in the microcode into the kernel. For that you
	  need to enable FIRMWARE_IN_KERNEL and add the vendor-supplied microcode
	  to the CONFIG_EXTRA_FIRMWARE config option.
1248

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config MICROCODE_INTEL
1250
	bool "Intel microcode loading support"
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	depends on MICROCODE
	default MICROCODE
	select FW_LOADER
	---help---
	  This options enables microcode patch loading support for Intel
	  processors.

1258 1259 1260
	  For the current Intel microcode data package go to
	  <https://downloadcenter.intel.com> and search for
	  'Linux Processor Microcode Data File'.
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1262
config MICROCODE_AMD
1263
	bool "AMD microcode loading support"
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	depends on MICROCODE
	select FW_LOADER
	---help---
	  If you select this option, microcode patch loading support for AMD
	  processors will be enabled.
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config MICROCODE_OLD_INTERFACE
1271
	def_bool y
1272 1273 1274 1275
	depends on MICROCODE

config X86_MSR
	tristate "/dev/cpu/*/msr - Model-specific register support"
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	---help---
1277 1278 1279 1280 1281 1282 1283 1284
	  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"
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	---help---
1286 1287 1288 1289 1290 1291 1292
	  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.

choice
	prompt "High Memory Support"
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	default HIGHMEM4G
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	depends on X86_32

config NOHIGHMEM
	bool "off"
	---help---
	  Linux can use up to 64 Gigabytes of physical memory on x86 systems.
	  However, the address space of 32-bit x86 processors is only 4
	  Gigabytes large. That means that, if you have a large amount of
	  physical memory, not all of it can be "permanently mapped" by the
	  kernel. The physical memory that's not permanently mapped is called
	  "high memory".

	  If you are compiling a kernel which will never run on a machine with
	  more than 1 Gigabyte total physical RAM, answer "off" here (default
	  choice and suitable for most users). This will result in a "3GB/1GB"
	  split: 3GB are mapped so that each process sees a 3GB virtual memory
	  space and the remaining part of the 4GB virtual memory space is used
	  by the kernel to permanently map as much physical memory as
	  possible.

	  If the machine has between 1 and 4 Gigabytes physical RAM, then
	  answer "4GB" here.

	  If more than 4 Gigabytes is used then answer "64GB" here. This
	  selection turns Intel PAE (Physical Address Extension) mode on.
	  PAE implements 3-level paging on IA32 processors. PAE is fully
	  supported by Linux, PAE mode is implemented on all recent Intel
	  processors (Pentium Pro and better). NOTE: If you say "64GB" here,
	  then the kernel will not boot on CPUs that don't support PAE!

	  The actual amount of total physical memory will either be
	  auto detected or can be forced by using a kernel command line option
	  such as "mem=256M". (Try "man bootparam" or see the documentation of
	  your boot loader (lilo or loadlin) about how to pass options to the
	  kernel at boot time.)

	  If unsure, say "off".

config HIGHMEM4G
	bool "4GB"
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	---help---
1335 1336 1337 1338 1339
	  Select this if you have a 32-bit processor and between 1 and 4
	  gigabytes of physical RAM.

config HIGHMEM64G
	bool "64GB"
1340
	depends on !M486
1341
	select X86_PAE
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	---help---
1343 1344 1345 1346 1347 1348
	  Select this if you have a 32-bit processor and more than 4
	  gigabytes of physical RAM.

endchoice

choice
1349
	prompt "Memory split" if EXPERT
1350 1351
	default VMSPLIT_3G
	depends on X86_32
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	---help---
1353 1354 1355 1356 1357 1358 1359 1360 1361 1362 1363 1364 1365 1366 1367 1368 1369 1370 1371 1372 1373 1374 1375 1376 1377 1378 1379 1380 1381 1382 1383 1384 1385 1386 1387 1388 1389 1390 1391
	  Select the desired split between kernel and user memory.

	  If the address range available to the kernel is less than the
	  physical memory installed, the remaining memory will be available
	  as "high memory". Accessing high memory is a little more costly
	  than low memory, as it needs to be mapped into the kernel first.
	  Note that increasing the kernel address space limits the range
	  available to user programs, making the address space there
	  tighter.  Selecting anything other than the default 3G/1G split
	  will also likely make your kernel incompatible with binary-only
	  kernel modules.

	  If you are not absolutely sure what you are doing, leave this
	  option alone!

	config VMSPLIT_3G
		bool "3G/1G user/kernel split"
	config VMSPLIT_3G_OPT
		depends on !X86_PAE
		bool "3G/1G user/kernel split (for full 1G low memory)"
	config VMSPLIT_2G
		bool "2G/2G user/kernel split"
	config VMSPLIT_2G_OPT
		depends on !X86_PAE
		bool "2G/2G user/kernel split (for full 2G low memory)"
	config VMSPLIT_1G
		bool "1G/3G user/kernel split"
endchoice

config PAGE_OFFSET
	hex
	default 0xB0000000 if VMSPLIT_3G_OPT
	default 0x80000000 if VMSPLIT_2G
	default 0x78000000 if VMSPLIT_2G_OPT
	default 0x40000000 if VMSPLIT_1G
	default 0xC0000000
	depends on X86_32

config HIGHMEM
1392
	def_bool y
1393 1394 1395
	depends on X86_32 && (HIGHMEM64G || HIGHMEM4G)

config X86_PAE
1396
	bool "PAE (Physical Address Extension) Support"
1397
	depends on X86_32 && !HIGHMEM4G
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	select SWIOTLB
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	---help---
1400 1401 1402 1403 1404
	  PAE is required for NX support, and furthermore enables
	  larger swapspace support for non-overcommit purposes. It
	  has the cost of more pagetable lookup overhead, and also
	  consumes more pagetable space per process.

1405 1406 1407 1408 1409 1410 1411 1412 1413 1414 1415 1416 1417 1418 1419 1420 1421 1422
config X86_5LEVEL
	bool "Enable 5-level page tables support"
	depends on X86_64
	---help---
	  5-level paging enables access to larger address space:
	  upto 128 PiB of virtual address space and 4 PiB of
	  physical address space.

	  It will be supported by future Intel CPUs.

	  Note: a kernel with this option enabled can only be booted
	  on machines that support the feature.

	  See Documentation/x86/x86_64/5level-paging.txt for more
	  information.

	  Say N if unsure.

1423
config ARCH_PHYS_ADDR_T_64BIT
1424 1425
	def_bool y
	depends on X86_64 || X86_PAE
1426

1427
config ARCH_DMA_ADDR_T_64BIT
1428 1429
	def_bool y
	depends on X86_64 || HIGHMEM64G
1430

1431
config X86_DIRECT_GBPAGES
1432 1433
	def_bool y
	depends on X86_64 && !DEBUG_PAGEALLOC && !KMEMCHECK
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	---help---
1435 1436 1437 1438
	  Certain kernel features effectively disable kernel
	  linear 1 GB mappings (even if the CPU otherwise
	  supports them), so don't confuse the user by printing
	  that we have them enabled.
1439

1440 1441 1442 1443 1444 1445 1446 1447 1448 1449 1450 1451 1452 1453 1454 1455 1456 1457 1458 1459 1460 1461 1462 1463 1464
config ARCH_HAS_MEM_ENCRYPT
	def_bool y

config AMD_MEM_ENCRYPT
	bool "AMD Secure Memory Encryption (SME) support"
	depends on X86_64 && CPU_SUP_AMD
	---help---
	  Say yes to enable support for the encryption of system memory.
	  This requires an AMD processor that supports Secure Memory
	  Encryption (SME).

config AMD_MEM_ENCRYPT_ACTIVE_BY_DEFAULT
	bool "Activate AMD Secure Memory Encryption (SME) by default"
	default y
	depends on AMD_MEM_ENCRYPT
	---help---
	  Say yes to have system memory encrypted by default if running on
	  an AMD processor that supports Secure Memory Encryption (SME).

	  If set to Y, then the encryption of system memory can be
	  deactivated with the mem_encrypt=off command line option.

	  If set to N, then the encryption of system memory can be
	  activated with the mem_encrypt=on command line option.

1465 1466 1467 1468
config ARCH_USE_MEMREMAP_PROT
	def_bool y
	depends on AMD_MEM_ENCRYPT

1469 1470
# Common NUMA Features
config NUMA
1471
	bool "Numa Memory Allocation and Scheduler Support"
1472
	depends on SMP
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	depends on X86_64 || (X86_32 && HIGHMEM64G && X86_BIGSMP)
	default y if X86_BIGSMP
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	---help---
1476
	  Enable NUMA (Non Uniform Memory Access) support.
1477

1478 1479 1480 1481
	  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.

1482
	  For 64-bit this is recommended if the system is Intel Core i7
1483 1484
	  (or later), AMD Opteron, or EM64T NUMA.

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	  For 32-bit this is only needed if you boot a 32-bit
1486
	  kernel on a 64-bit NUMA platform.
1487 1488

	  Otherwise, you should say N.
1489

1490
config AMD_NUMA
1491 1492
	def_bool y
	prompt "Old style AMD Opteron NUMA detection"
1493
	depends on X86_64 && NUMA && PCI
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	---help---
1495 1496 1497 1498 1499
	  Enable AMD NUMA node topology detection.  You should say Y here if
	  you have a multi processor AMD system. This uses an old method to
	  read the NUMA configuration directly from the builtin Northbridge
	  of Opteron. It is recommended to use X86_64_ACPI_NUMA instead,
	  which also takes priority if both are compiled in.
1500 1501

config X86_64_ACPI_NUMA
1502 1503
	def_bool y
	prompt "ACPI NUMA detection"
1504 1505
	depends on X86_64 && NUMA && ACPI && PCI
	select ACPI_NUMA
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	---help---
1507 1508
	  Enable ACPI SRAT based node topology detection.

1509 1510 1511 1512 1513 1514 1515 1516 1517
# Some NUMA nodes have memory ranges that span
# other nodes.  Even though a pfn is valid and
# between a node's start and end pfns, it may not
# reside on that node.  See memmap_init_zone()
# for details.
config NODES_SPAN_OTHER_NODES
	def_bool y
	depends on X86_64_ACPI_NUMA

1518 1519
config NUMA_EMU
	bool "NUMA emulation"
1520
	depends on NUMA
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	---help---
1522 1523 1524 1525 1526
	  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 NODES_SHIFT
1527
	int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP
1528 1529
	range 1 10
	default "10" if MAXSMP
1530 1531 1532
	default "6" if X86_64
	default "3"
	depends on NEED_MULTIPLE_NODES
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	---help---
1534
	  Specify the maximum number of NUMA Nodes available on the target
1535
	  system.  Increases memory reserved to accommodate various tables.
1536 1537

config ARCH_HAVE_MEMORY_PRESENT
1538
	def_bool y
1539 1540 1541
	depends on X86_32 && DISCONTIGMEM

config NEED_NODE_MEMMAP_SIZE
1542
	def_bool y
1543 1544 1545 1546
	depends on X86_32 && (DISCONTIGMEM || SPARSEMEM)

config ARCH_FLATMEM_ENABLE
	def_bool y
1547
	depends on X86_32 && !NUMA
1548 1549 1550

config ARCH_DISCONTIGMEM_ENABLE
	def_bool y
1551
	depends on NUMA && X86_32
1552 1553 1554

config ARCH_DISCONTIGMEM_DEFAULT
	def_bool y
1555 1556
	depends on NUMA && X86_32

1557 1558
config ARCH_SPARSEMEM_ENABLE
	def_bool y
1559
	depends on X86_64 || NUMA || X86_32 || X86_32_NON_STANDARD
1560 1561 1562
	select SPARSEMEM_STATIC if X86_32
	select SPARSEMEM_VMEMMAP_ENABLE if X86_64

1563 1564 1565 1566
config ARCH_SPARSEMEM_DEFAULT
	def_bool y
	depends on X86_64

1567 1568
config ARCH_SELECT_MEMORY_MODEL
	def_bool y
1569
	depends on ARCH_SPARSEMEM_ENABLE
1570 1571

config ARCH_MEMORY_PROBE
1572
	bool "Enable sysfs memory/probe interface"
1573
	depends on X86_64 && MEMORY_HOTPLUG
1574 1575 1576 1577
	help
	  This option enables a sysfs memory/probe interface for testing.
	  See Documentation/memory-hotplug.txt for more information.
	  If you are unsure how to answer this question, answer N.
1578

1579 1580 1581 1582
config ARCH_PROC_KCORE_TEXT
	def_bool y
	depends on X86_64 && PROC_KCORE

1583 1584 1585 1586 1587
config ILLEGAL_POINTER_VALUE
       hex
       default 0 if X86_32
       default 0xdead000000000000 if X86_64

1588 1589
source "mm/Kconfig"

1590 1591 1592
config X86_PMEM_LEGACY_DEVICE
	bool

1593
config X86_PMEM_LEGACY
1594
	tristate "Support non-standard NVDIMMs and ADR protected memory"
1595 1596
	depends on PHYS_ADDR_T_64BIT
	depends on BLK_DEV
1597
	select X86_PMEM_LEGACY_DEVICE
1598
	select LIBNVDIMM
1599 1600 1601 1602 1603 1604 1605 1606
	help
	  Treat memory marked using the non-standard e820 type of 12 as used
	  by the Intel Sandy Bridge-EP reference BIOS as protected memory.
	  The kernel will offer these regions to the 'pmem' driver so
	  they can be used for persistent storage.

	  Say Y if unsure.

1607 1608
config HIGHPTE
	bool "Allocate 3rd-level pagetables from highmem"
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	depends on HIGHMEM
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	---help---
1611 1612 1613 1614 1615
	  The VM uses one page table entry for each page of physical memory.
	  For systems with a lot of RAM, this can be wasteful of precious
	  low memory.  Setting this option will put user-space page table
	  entries in high memory.

1616
config X86_CHECK_BIOS_CORRUPTION
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	bool "Check for low memory corruption"
	---help---
	  Periodically check for memory corruption in low memory, which
	  is suspected to be caused by BIOS.  Even when enabled in the
	  configuration, it is disabled at runtime.  Enable it by
	  setting "memory_corruption_check=1" on the kernel command
	  line.  By default it scans the low 64k of memory every 60
	  seconds; see the memory_corruption_check_size and
	  memory_corruption_check_period parameters in
1626
	  Documentation/admin-guide/kernel-parameters.rst to adjust this.
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	  When enabled with the default parameters, this option has
	  almost no overhead, as it reserves a relatively small amount
	  of memory and scans it infrequently.  It both detects corruption
	  and prevents it from affecting the running system.

	  It is, however, intended as a diagnostic tool; if repeatable
	  BIOS-originated corruption always affects the same memory,
	  you can use memmap= to prevent the kernel from using that
	  memory.
1637

1638
config X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK
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	bool "Set the default setting of memory_corruption_check"
1640 1641
	depends on X86_CHECK_BIOS_CORRUPTION
	default y
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1642 1643 1644
	---help---
	  Set whether the default state of memory_corruption_check is
	  on or off.
1645

1646
config X86_RESERVE_LOW
1647 1648 1649
	int "Amount of low memory, in kilobytes, to reserve for the BIOS"
	default 64
	range 4 640
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	---help---
1651 1652 1653 1654 1655 1656 1657 1658 1659
	  Specify the amount of low memory to reserve for the BIOS.

	  The first page contains BIOS data structures that the kernel
	  must not use, so that page must always be reserved.

	  By default we reserve the first 64K of physical RAM, as a
	  number of BIOSes are known to corrupt that memory range
	  during events such as suspend/resume or monitor cable
	  insertion, so it must not be used by the kernel.
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1661 1662 1663 1664 1665
	  You can set this to 4 if you are absolutely sure that you
	  trust the BIOS to get all its memory reservations and usages
	  right.  If you know your BIOS have problems beyond the
	  default 64K area, you can set this to 640 to avoid using the
	  entire low memory range.
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1667 1668 1669 1670 1671
	  If you have doubts about the BIOS (e.g. suspend/resume does
	  not work or there's kernel crashes after certain hardware
	  hotplug events) then you might want to enable
	  X86_CHECK_BIOS_CORRUPTION=y to allow the kernel to check
	  typical corruption patterns.
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1673
	  Leave this to the default value of 64 if you are unsure.
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1675 1676
config MATH_EMULATION
	bool
1677
	depends on MODIFY_LDT_SYSCALL
1678 1679 1680 1681 1682 1683 1684 1685 1686 1687 1688 1689 1690 1691 1692 1693 1694 1695 1696 1697 1698 1699 1700 1701 1702
	prompt "Math emulation" if X86_32
	---help---
	  Linux can emulate a math coprocessor (used for floating point
	  operations) if you don't have one. 486DX and Pentium processors have
	  a math coprocessor built in, 486SX and 386 do not, unless you added
	  a 487DX or 387, respectively. (The messages during boot time can
	  give you some hints here ["man dmesg"].) Everyone needs either a
	  coprocessor or this emulation.

	  If you don't have a math coprocessor, you need to say Y here; if you
	  say Y here even though you have a coprocessor, the coprocessor will
	  be used nevertheless. (This behavior can be changed with the kernel
	  command line option "no387", which comes handy if your coprocessor
	  is broken. Try "man bootparam" or see the documentation of your boot
	  loader (lilo or loadlin) about how to pass options to the kernel at
	  boot time.) This means that it is a good idea to say Y here if you
	  intend to use this kernel on different machines.

	  More information about the internals of the Linux math coprocessor
	  emulation can be found in <file:arch/x86/math-emu/README>.

	  If you are not sure, say Y; apart from resulting in a 66 KB bigger
	  kernel, it won't hurt.

config MTRR
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	def_bool y
1704
	prompt "MTRR (Memory Type Range Register) support" if EXPERT
1705 1706 1707 1708 1709 1710 1711 1712 1713 1714 1715 1716 1717 1718 1719 1720 1721 1722 1723 1724 1725 1726 1727 1728 1729 1730 1731 1732 1733 1734
	---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:

	  The Cyrix 6x86, 6x86MX and M II processors have Address Range
	  Registers (ARRs) which provide a similar functionality to MTRRs. For
	  these, the ARRs are used to emulate the MTRRs.
	  The AMD K6-2 (stepping 8 and above) and K6-3 processors have two
	  MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing
	  write-combining. All of these processors are supported by this code
	  and it makes sense to say Y here if you have one of them.

	  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.

	  You can safely say Y even if your machine doesn't have MTRRs, you'll
	  just add about 9 KB to your kernel.

1735
	  See <file:Documentation/x86/mtrr.txt> for more information.
1736

1737
config MTRR_SANITIZER
1738
	def_bool y
1739 1740
	prompt "MTRR cleanup support"
	depends on MTRR
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	---help---
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	  Convert MTRR layout from continuous to discrete, so X drivers can
	  add writeback entries.
1744

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	  Can be disabled with disable_mtrr_cleanup on the kernel command line.
1746
	  The largest mtrr entry size for a continuous block can be set with
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	  mtrr_chunk_size.
1748

1749
	  If unsure, say Y.
1750 1751

config MTRR_SANITIZER_ENABLE_DEFAULT
1752 1753 1754
	int "MTRR cleanup enable value (0-1)"
	range 0 1
	default "0"
1755
	depends on MTRR_SANITIZER
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	---help---
1757
	  Enable mtrr cleanup default value
1758

1759 1760 1761 1762 1763
config MTRR_SANITIZER_SPARE_REG_NR_DEFAULT
	int "MTRR cleanup spare reg num (0-7)"
	range 0 7
	default "1"
	depends on MTRR_SANITIZER
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	---help---
1765
	  mtrr cleanup spare entries default, it can be changed via
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	  mtrr_spare_reg_nr=N on the kernel command line.
1767

1768
config X86_PAT
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	def_bool y
1770
	prompt "x86 PAT support" if EXPERT
1771
	depends on MTRR
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	---help---
1773
	  Use PAT attributes to setup page level cache control.
1774

1775 1776 1777 1778
	  PATs are the modern equivalents of MTRRs and are much more
	  flexible than MTRRs.

	  Say N here if you see bootup problems (boot crash, boot hang,
1779
	  spontaneous reboots) or a non-working video driver.
1780 1781 1782

	  If unsure, say Y.

1783 1784 1785 1786
config ARCH_USES_PG_UNCACHED
	def_bool y
	depends on X86_PAT

1787 1788 1789 1790 1791 1792 1793 1794 1795
config ARCH_RANDOM
	def_bool y
	prompt "x86 architectural random number generator" if EXPERT
	---help---
	  Enable the x86 architectural RDRAND instruction
	  (Intel Bull Mountain technology) to generate random numbers.
	  If supported, this is a high bandwidth, cryptographically
	  secure hardware random number generator.

1796 1797 1798 1799 1800 1801 1802 1803 1804 1805 1806
config X86_SMAP
	def_bool y
	prompt "Supervisor Mode Access Prevention" if EXPERT
	---help---
	  Supervisor Mode Access Prevention (SMAP) is a security
	  feature in newer Intel processors.  There is a small
	  performance cost if this enabled and turned on; there is
	  also a small increase in the kernel size if this is enabled.

	  If unsure, say Y.

1807 1808 1809
config X86_INTEL_MPX
	prompt "Intel MPX (Memory Protection Extensions)"
	def_bool n
1810 1811 1812
	# Note: only available in 64-bit mode due to VMA flags shortage
	depends on CPU_SUP_INTEL && X86_64
	select ARCH_USES_HIGH_VMA_FLAGS
1813 1814 1815 1816 1817 1818 1819 1820 1821 1822 1823 1824 1825 1826 1827 1828 1829 1830 1831 1832 1833 1834
	---help---
	  MPX provides hardware features that can be used in
	  conjunction with compiler-instrumented code to check
	  memory references.  It is designed to detect buffer
	  overflow or underflow bugs.

	  This option enables running applications which are
	  instrumented or otherwise use MPX.  It does not use MPX
	  itself inside the kernel or to protect the kernel
	  against bad memory references.

	  Enabling this option will make the kernel larger:
	  ~8k of kernel text and 36 bytes of data on a 64-bit
	  defconfig.  It adds a long to the 'mm_struct' which
	  will increase the kernel memory overhead of each
	  process and adds some branches to paths used during
	  exec() and munmap().

	  For details, see Documentation/x86/intel_mpx.txt

	  If unsure, say N.

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config X86_INTEL_MEMORY_PROTECTION_KEYS
1836
	prompt "Intel Memory Protection Keys"
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	def_bool y
1838
	# Note: only available in 64-bit mode
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	depends on CPU_SUP_INTEL && X86_64
1840 1841
	select ARCH_USES_HIGH_VMA_FLAGS
	select ARCH_HAS_PKEYS
1842 1843 1844 1845 1846 1847 1848 1849
	---help---
	  Memory Protection Keys provides a mechanism for enforcing
	  page-based protections, but without requiring modification of the
	  page tables when an application changes protection domains.

	  For details, see Documentation/x86/protection-keys.txt

	  If unsure, say y.
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1851
config EFI
1852
	bool "EFI runtime service support"
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	depends on ACPI
1854
	select UCS2_STRING
1855
	select EFI_RUNTIME_WRAPPERS
1856
	---help---
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	  This enables the kernel to use EFI runtime services that are
	  available (such as the EFI variable services).
1859

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	  This option is only useful on systems that have EFI firmware.
	  In addition, you should use the latest ELILO loader available
	  at <http://elilo.sourceforge.net> in order to take advantage
	  of EFI runtime services. However, even with this option, the
	  resultant kernel should continue to boot on existing non-EFI
	  platforms.
1866

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config EFI_STUB
       bool "EFI stub support"
1869
       depends on EFI && !X86_USE_3DNOW
1870
       select RELOCATABLE
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       ---help---
          This kernel feature allows a bzImage to be loaded directly
	  by EFI firmware without the use of a bootloader.

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	  See Documentation/efi-stub.txt for more information.
1876

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config EFI_MIXED
	bool "EFI mixed-mode support"
	depends on EFI_STUB && X86_64
	---help---
	   Enabling this feature allows a 64-bit kernel to be booted
	   on a 32-bit firmware, provided that your CPU supports 64-bit
	   mode.

	   Note that it is not possible to boot a mixed-mode enabled
	   kernel via the EFI boot stub - a bootloader that supports
	   the EFI handover protocol must be used.

	   If unsure, say N.

1891
config SECCOMP
1892 1893
	def_bool y
	prompt "Enable seccomp to safely compute untrusted bytecode"
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	---help---
1895 1896 1897 1898 1899 1900
	  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
1901
	  enabled via prctl(PR_SET_SECCOMP), it cannot be disabled
1902 1903 1904 1905 1906 1907 1908 1909 1910
	  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.

source kernel/Kconfig.hz

config KEXEC
	bool "kexec system call"
1911
	select KEXEC_CORE
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	---help---
1913 1914 1915 1916 1917 1918 1919 1920 1921
	  kexec is a system call that implements the ability to shutdown your
	  current kernel, and to start another kernel.  It is like a reboot
	  but it is independent of the system firmware.   And like a reboot
	  you can start any kernel with it, not just Linux.

	  The name comes from the similarity to the exec system call.

	  It is an ongoing process to be certain the hardware in a machine
	  is properly shutdown, so do not be surprised if this code does not
1922 1923 1924
	  initially work for you.  As of this writing the exact hardware
	  interface is strongly in flux, so no good recommendation can be
	  made.
1925

1926 1927
config KEXEC_FILE
	bool "kexec file based system call"
1928
	select KEXEC_CORE
1929 1930 1931 1932 1933 1934 1935 1936 1937 1938
	select BUILD_BIN2C
	depends on X86_64
	depends on CRYPTO=y
	depends on CRYPTO_SHA256=y
	---help---
	  This is new version of kexec system call. This system call is
	  file based and takes file descriptors as system call argument
	  for kernel and initramfs as opposed to list of segments as
	  accepted by previous system call.

1939 1940
config KEXEC_VERIFY_SIG
	bool "Verify kernel signature during kexec_file_load() syscall"
1941
	depends on KEXEC_FILE
1942 1943
	---help---
	  This option makes kernel signature verification mandatory for
1944 1945 1946 1947 1948
	  the kexec_file_load() syscall.

	  In addition to that option, you need to enable signature
	  verification for the corresponding kernel image type being
	  loaded in order for this to work.
1949 1950 1951 1952 1953 1954 1955 1956 1957

config KEXEC_BZIMAGE_VERIFY_SIG
	bool "Enable bzImage signature verification support"
	depends on KEXEC_VERIFY_SIG
	depends on SIGNED_PE_FILE_VERIFICATION
	select SYSTEM_TRUSTED_KEYRING
	---help---
	  Enable bzImage signature verification support.

1958
config CRASH_DUMP
1959
	bool "kernel crash dumps"
1960
	depends on X86_64 || (X86_32 && HIGHMEM)
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	---help---
1962 1963 1964 1965 1966 1967 1968 1969 1970 1971
	  Generate crash dump after being started by kexec.
	  This should be normally only set in special crash dump kernels
	  which are loaded in the main kernel with kexec-tools into
	  a specially reserved region and then later executed after
	  a crash by kdump/kexec. The crash dump kernel must be compiled
	  to a memory address not used by the main kernel or BIOS using
	  PHYSICAL_START, or it must be built as a relocatable image
	  (CONFIG_RELOCATABLE=y).
	  For more details see Documentation/kdump/kdump.txt

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config KEXEC_JUMP
1973
	bool "kexec jump"
1974
	depends on KEXEC && HIBERNATION
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	---help---
1976 1977
	  Jump between original kernel and kexeced kernel and invoke
	  code in physical address mode via KEXEC
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1979
config PHYSICAL_START
1980
	hex "Physical address where the kernel is loaded" if (EXPERT || CRASH_DUMP)
1981
	default "0x1000000"
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	---help---
1983 1984 1985 1986 1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999
	  This gives the physical address where the kernel is loaded.

	  If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then
	  bzImage will decompress itself to above physical address and
	  run from there. Otherwise, bzImage will run from the address where
	  it has been loaded by the boot loader and will ignore above physical
	  address.

	  In normal kdump cases one does not have to set/change this option
	  as now bzImage can be compiled as a completely relocatable image
	  (CONFIG_RELOCATABLE=y) and be used to load and run from a different
	  address. This option is mainly useful for the folks who don't want
	  to use a bzImage for capturing the crash dump and want to use a
	  vmlinux instead. vmlinux is not relocatable hence a kernel needs
	  to be specifically compiled to run from a specific memory area
	  (normally a reserved region) and this option comes handy.

2000 2001 2002 2003 2004 2005 2006 2007 2008
	  So if you are using bzImage for capturing the crash dump,
	  leave the value here unchanged to 0x1000000 and set
	  CONFIG_RELOCATABLE=y.  Otherwise if you plan to use vmlinux
	  for capturing the crash dump change this value to start of
	  the reserved region.  In other words, it can be set based on
	  the "X" value as specified in the "crashkernel=YM@XM"
	  command line boot parameter passed to the panic-ed
	  kernel. Please take a look at Documentation/kdump/kdump.txt
	  for more details about crash dumps.
2009 2010 2011 2012 2013 2014 2015 2016 2017 2018 2019 2020

	  Usage of bzImage for capturing the crash dump is recommended as
	  one does not have to build two kernels. Same kernel can be used
	  as production kernel and capture kernel. Above option should have
	  gone away after relocatable bzImage support is introduced. But it
	  is present because there are users out there who continue to use
	  vmlinux for dump capture. This option should go away down the
	  line.

	  Don't change this unless you know what you are doing.

config RELOCATABLE
2021 2022
	bool "Build a relocatable kernel"
	default y
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	---help---
2024 2025 2026 2027 2028 2029 2030 2031 2032 2033 2034
	  This builds a kernel image that retains relocation information
	  so it can be loaded someplace besides the default 1MB.
	  The relocations tend to make the kernel binary about 10% larger,
	  but are discarded at runtime.

	  One use is for the kexec on panic case where the recovery kernel
	  must live at a different physical address than the primary
	  kernel.

	  Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address
	  it has been loaded at and the compile time physical address
2035
	  (CONFIG_PHYSICAL_START) is used as the minimum location.
2036

2037
config RANDOMIZE_BASE
2038
	bool "Randomize the address of the kernel image (KASLR)"
2039
	depends on RELOCATABLE
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	default y
2041
	---help---
2042 2043 2044 2045 2046 2047 2048
	  In support of Kernel Address Space Layout Randomization (KASLR),
	  this randomizes the physical address at which the kernel image
	  is decompressed and the virtual address where the kernel
	  image is mapped, as a security feature that deters exploit
	  attempts relying on knowledge of the location of kernel
	  code internals.

2049 2050 2051 2052 2053 2054 2055 2056 2057 2058
	  On 64-bit, the kernel physical and virtual addresses are
	  randomized separately. The physical address will be anywhere
	  between 16MB and the top of physical memory (up to 64TB). The
	  virtual address will be randomized from 16MB up to 1GB (9 bits
	  of entropy). Note that this also reduces the memory space
	  available to kernel modules from 1.5GB to 1GB.

	  On 32-bit, the kernel physical and virtual addresses are
	  randomized together. They will be randomized from 16MB up to
	  512MB (8 bits of entropy).
2059 2060 2061 2062

	  Entropy is generated using the RDRAND instruction if it is
	  supported. If RDTSC is supported, its value is mixed into
	  the entropy pool as well. If neither RDRAND nor RDTSC are
2063 2064 2065 2066 2067 2068
	  supported, then entropy is read from the i8254 timer. The
	  usable entropy is limited by the kernel being built using
	  2GB addressing, and that PHYSICAL_ALIGN must be at a
	  minimum of 2MB. As a result, only 10 bits of entropy are
	  theoretically possible, but the implementations are further
	  limited due to memory layouts.
2069

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	  If unsure, say Y.
2071 2072

# Relocation on x86 needs some additional build support
2073 2074
config X86_NEED_RELOCS
	def_bool y
2075
	depends on RANDOMIZE_BASE || (X86_32 && RELOCATABLE)
2076

2077
config PHYSICAL_ALIGN
2078
	hex "Alignment value to which kernel should be aligned"
2079
	default "0x200000"
2080 2081
	range 0x2000 0x1000000 if X86_32
	range 0x200000 0x1000000 if X86_64
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	---help---
2083 2084 2085 2086 2087 2088 2089 2090 2091 2092 2093 2094 2095 2096 2097 2098
	  This value puts the alignment restrictions on physical address
	  where kernel is loaded and run from. Kernel is compiled for an
	  address which meets above alignment restriction.

	  If bootloader loads the kernel at a non-aligned address and
	  CONFIG_RELOCATABLE is set, kernel will move itself to nearest
	  address aligned to above value and run from there.

	  If bootloader loads the kernel at a non-aligned address and
	  CONFIG_RELOCATABLE is not set, kernel will ignore the run time
	  load address and decompress itself to the address it has been
	  compiled for and run from there. The address for which kernel is
	  compiled already meets above alignment restrictions. Hence the
	  end result is that kernel runs from a physical address meeting
	  above alignment restrictions.

2099 2100 2101
	  On 32-bit this value must be a multiple of 0x2000. On 64-bit
	  this value must be a multiple of 0x200000.

2102 2103
	  Don't change this unless you know what you are doing.

2104 2105 2106 2107 2108 2109 2110 2111 2112 2113 2114 2115 2116 2117 2118
config RANDOMIZE_MEMORY
	bool "Randomize the kernel memory sections"
	depends on X86_64
	depends on RANDOMIZE_BASE
	default RANDOMIZE_BASE
	---help---
	   Randomizes the base virtual address of kernel memory sections
	   (physical memory mapping, vmalloc & vmemmap). This security feature
	   makes exploits relying on predictable memory locations less reliable.

	   The order of allocations remains unchanged. Entropy is generated in
	   the same way as RANDOMIZE_BASE. Current implementation in the optimal
	   configuration have in average 30,000 different possible virtual
	   addresses for each memory section.

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	   If unsure, say Y.
2120

2121 2122 2123 2124 2125 2126 2127 2128 2129 2130 2131 2132 2133 2134 2135
config RANDOMIZE_MEMORY_PHYSICAL_PADDING
	hex "Physical memory mapping padding" if EXPERT
	depends on RANDOMIZE_MEMORY
	default "0xa" if MEMORY_HOTPLUG
	default "0x0"
	range 0x1 0x40 if MEMORY_HOTPLUG
	range 0x0 0x40
	---help---
	   Define the padding in terabytes added to the existing physical
	   memory size during kernel memory randomization. It is useful
	   for memory hotplug support but reduces the entropy available for
	   address randomization.

	   If unsure, leave at the default value.

2136
config HOTPLUG_CPU
2137
	bool "Support for hot-pluggable CPUs"
2138
	depends on SMP
2139
	---help---
2140 2141 2142 2143 2144
	  Say Y here to allow turning CPUs off and on. CPUs can be
	  controlled through /sys/devices/system/cpu.
	  ( Note: power management support will enable this option
	    automatically on SMP systems. )
	  Say N if you want to disable CPU hotplug.
2145

2146 2147 2148
config BOOTPARAM_HOTPLUG_CPU0
	bool "Set default setting of cpu0_hotpluggable"
	default n
2149
	depends on HOTPLUG_CPU
2150 2151 2152 2153 2154 2155 2156 2157 2158 2159 2160 2161 2162 2163 2164 2165 2166 2167 2168 2169 2170 2171 2172 2173 2174
	---help---
	  Set whether default state of cpu0_hotpluggable is on or off.

	  Say Y here to enable CPU0 hotplug by default. If this switch
	  is turned on, there is no need to give cpu0_hotplug kernel
	  parameter and the CPU0 hotplug feature is enabled by default.

	  Please note: there are two known CPU0 dependencies if you want
	  to enable the CPU0 hotplug feature either by this switch or by
	  cpu0_hotplug kernel parameter.

	  First, resume from hibernate or suspend always starts from CPU0.
	  So hibernate and suspend are prevented if CPU0 is offline.

	  Second dependency is PIC interrupts always go to CPU0. CPU0 can not
	  offline if any interrupt can not migrate out of CPU0. There may
	  be other CPU0 dependencies.

	  Please make sure the dependencies are under your control before
	  you enable this feature.

	  Say N if you don't want to enable CPU0 hotplug feature by default.
	  You still can enable the CPU0 hotplug feature at boot by kernel
	  parameter cpu0_hotplug.

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config DEBUG_HOTPLUG_CPU0
	def_bool n
	prompt "Debug CPU0 hotplug"
2178
	depends on HOTPLUG_CPU
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	---help---
	  Enabling this option offlines CPU0 (if CPU0 can be offlined) as
	  soon as possible and boots up userspace with CPU0 offlined. User
	  can online CPU0 back after boot time.

	  To debug CPU0 hotplug, you need to enable CPU0 offline/online
	  feature by either turning on CONFIG_BOOTPARAM_HOTPLUG_CPU0 during
	  compilation or giving cpu0_hotplug kernel parameter at boot.

	  If unsure, say N.

2190
config COMPAT_VDSO
2191 2192
	def_bool n
	prompt "Disable the 32-bit vDSO (needed for glibc 2.3.3)"
2193
	depends on COMPAT_32
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	---help---
2195 2196 2197
	  Certain buggy versions of glibc will crash if they are
	  presented with a 32-bit vDSO that is not mapped at the address
	  indicated in its segment table.
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2199 2200 2201 2202 2203
	  The bug was introduced by f866314b89d56845f55e6f365e18b31ec978ec3a
	  and fixed by 3b3ddb4f7db98ec9e912ccdf54d35df4aa30e04a and
	  49ad572a70b8aeb91e57483a11dd1b77e31c4468.  Glibc 2.3.3 is
	  the only released version with the bug, but OpenSUSE 9
	  contains a buggy "glibc 2.3.2".
2204

2205 2206 2207 2208 2209 2210 2211 2212 2213
	  The symptom of the bug is that everything crashes on startup, saying:
	  dl_main: Assertion `(void *) ph->p_vaddr == _rtld_local._dl_sysinfo_dso' failed!

	  Saying Y here changes the default value of the vdso32 boot
	  option from 1 to 0, which turns off the 32-bit vDSO entirely.
	  This works around the glibc bug but hurts performance.

	  If unsure, say N: if you are compiling your own kernel, you
	  are unlikely to be using a buggy version of glibc.
2214

2215 2216 2217 2218 2219 2220 2221 2222 2223 2224 2225 2226 2227 2228 2229 2230 2231 2232 2233 2234 2235 2236 2237 2238 2239 2240 2241 2242 2243 2244 2245 2246 2247 2248 2249 2250 2251 2252 2253 2254 2255 2256 2257 2258 2259 2260 2261 2262 2263
choice
	prompt "vsyscall table for legacy applications"
	depends on X86_64
	default LEGACY_VSYSCALL_EMULATE
	help
	  Legacy user code that does not know how to find the vDSO expects
	  to be able to issue three syscalls by calling fixed addresses in
	  kernel space. Since this location is not randomized with ASLR,
	  it can be used to assist security vulnerability exploitation.

	  This setting can be changed at boot time via the kernel command
	  line parameter vsyscall=[native|emulate|none].

	  On a system with recent enough glibc (2.14 or newer) and no
	  static binaries, you can say None without a performance penalty
	  to improve security.

	  If unsure, select "Emulate".

	config LEGACY_VSYSCALL_NATIVE
		bool "Native"
		help
		  Actual executable code is located in the fixed vsyscall
		  address mapping, implementing time() efficiently. Since
		  this makes the mapping executable, it can be used during
		  security vulnerability exploitation (traditionally as
		  ROP gadgets). This configuration is not recommended.

	config LEGACY_VSYSCALL_EMULATE
		bool "Emulate"
		help
		  The kernel traps and emulates calls into the fixed
		  vsyscall address mapping. This makes the mapping
		  non-executable, but it still contains known contents,
		  which could be used in certain rare security vulnerability
		  exploits. This configuration is recommended when userspace
		  still uses the vsyscall area.

	config LEGACY_VSYSCALL_NONE
		bool "None"
		help
		  There will be no vsyscall mapping at all. This will
		  eliminate any risk of ASLR bypass due to the vsyscall
		  fixed address mapping. Attempts to use the vsyscalls
		  will be reported to dmesg, so that either old or
		  malicious userspace programs can be identified.

endchoice

2264 2265
config CMDLINE_BOOL
	bool "Built-in kernel command line"
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	---help---
2267 2268 2269 2270 2271 2272 2273 2274
	  Allow for specifying boot arguments to the kernel at
	  build time.  On some systems (e.g. embedded ones), it is
	  necessary or convenient to provide some or all of the
	  kernel boot arguments with the kernel itself (that is,
	  to not rely on the boot loader to provide them.)

	  To compile command line arguments into the kernel,
	  set this option to 'Y', then fill in the
2275
	  boot arguments in CONFIG_CMDLINE.
2276 2277 2278 2279 2280 2281 2282 2283

	  Systems with fully functional boot loaders (i.e. non-embedded)
	  should leave this option set to 'N'.

config CMDLINE
	string "Built-in kernel command string"
	depends on CMDLINE_BOOL
	default ""
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	---help---
2285 2286 2287 2288 2289 2290 2291 2292 2293 2294 2295 2296 2297 2298 2299
	  Enter arguments here that should be compiled into the kernel
	  image and used at boot time.  If the boot loader provides a
	  command line at boot time, it is appended to this string to
	  form the full kernel command line, when the system boots.

	  However, you can use the CONFIG_CMDLINE_OVERRIDE option to
	  change this behavior.

	  In most cases, the command line (whether built-in or provided
	  by the boot loader) should specify the device for the root
	  file system.

config CMDLINE_OVERRIDE
	bool "Built-in command line overrides boot loader arguments"
	depends on CMDLINE_BOOL
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	---help---
2301 2302 2303 2304 2305 2306
	  Set this option to 'Y' to have the kernel ignore the boot loader
	  command line, and use ONLY the built-in command line.

	  This is used to work around broken boot loaders.  This should
	  be set to 'N' under normal conditions.

2307 2308 2309 2310 2311 2312 2313 2314 2315 2316 2317 2318 2319 2320 2321 2322
config MODIFY_LDT_SYSCALL
	bool "Enable the LDT (local descriptor table)" if EXPERT
	default y
	---help---
	  Linux can allow user programs to install a per-process x86
	  Local Descriptor Table (LDT) using the modify_ldt(2) system
	  call.  This is required to run 16-bit or segmented code such as
	  DOSEMU or some Wine programs.  It is also used by some very old
	  threading libraries.

	  Enabling this feature adds a small amount of overhead to
	  context switches and increases the low-level kernel attack
	  surface.  Disabling it removes the modify_ldt(2) system call.

	  Saying 'N' here may make sense for embedded or server kernels.

2323 2324
source "kernel/livepatch/Kconfig"

2325 2326
endmenu

2327 2328 2329 2330
config ARCH_HAS_ADD_PAGES
	def_bool y
	depends on X86_64 && ARCH_ENABLE_MEMORY_HOTPLUG

2331 2332 2333 2334
config ARCH_ENABLE_MEMORY_HOTPLUG
	def_bool y
	depends on X86_64 || (X86_32 && HIGHMEM)

2335 2336 2337 2338
config ARCH_ENABLE_MEMORY_HOTREMOVE
	def_bool y
	depends on MEMORY_HOTPLUG

2339
config USE_PERCPU_NUMA_NODE_ID
2340
	def_bool y
2341 2342
	depends on NUMA

2343 2344 2345 2346
config ARCH_ENABLE_SPLIT_PMD_PTLOCK
	def_bool y
	depends on X86_64 || X86_PAE

2347 2348 2349 2350
config ARCH_ENABLE_HUGEPAGE_MIGRATION
	def_bool y
	depends on X86_64 && HUGETLB_PAGE && MIGRATION

2351 2352 2353 2354
config ARCH_ENABLE_THP_MIGRATION
	def_bool y
	depends on X86_64 && TRANSPARENT_HUGEPAGE

2355
menu "Power management and ACPI options"
2356 2357

config ARCH_HIBERNATION_HEADER
2358
	def_bool y
2359 2360 2361 2362 2363 2364
	depends on X86_64 && HIBERNATION

source "kernel/power/Kconfig"

source "drivers/acpi/Kconfig"

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2365 2366
source "drivers/sfi/Kconfig"

2367
config X86_APM_BOOT
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	def_bool y
2369
	depends on APM
2370

2371 2372
menuconfig APM
	tristate "APM (Advanced Power Management) BIOS support"
2373
	depends on X86_32 && PM_SLEEP
2374 2375 2376 2377 2378 2379 2380 2381 2382 2383 2384 2385 2386 2387 2388
	---help---
	  APM is a BIOS specification for saving power using several different
	  techniques. This is mostly useful for battery powered laptops with
	  APM compliant BIOSes. If you say Y here, the system time will be
	  reset after a RESUME operation, the /proc/apm device will provide
	  battery status information, and user-space programs will receive
	  notification of APM "events" (e.g. battery status change).

	  If you select "Y" here, you can disable actual use of the APM
	  BIOS by passing the "apm=off" option to the kernel at boot time.

	  Note that the APM support is almost completely disabled for
	  machines with more than one CPU.

	  In order to use APM, you will need supporting software. For location
2389 2390
	  and more information, read <file:Documentation/power/apm-acpi.txt>
	  and the Battery Powered Linux mini-HOWTO, available from
2391 2392 2393 2394 2395 2396 2397 2398 2399 2400 2401 2402 2403 2404 2405 2406 2407 2408 2409 2410 2411 2412 2413 2414 2415 2416 2417 2418 2419 2420 2421 2422 2423 2424 2425 2426 2427 2428 2429 2430 2431 2432 2433
	  <http://www.tldp.org/docs.html#howto>.

	  This driver does not spin down disk drives (see the hdparm(8)
	  manpage ("man 8 hdparm") for that), and it doesn't turn off
	  VESA-compliant "green" monitors.

	  This driver does not support the TI 4000M TravelMate and the ACER
	  486/DX4/75 because they don't have compliant BIOSes. Many "green"
	  desktop machines also don't have compliant BIOSes, and this driver
	  may cause those machines to panic during the boot phase.

	  Generally, if you don't have a battery in your machine, there isn't
	  much point in using this driver and you should say N. If you get
	  random kernel OOPSes or reboots that don't seem to be related to
	  anything, try disabling/enabling this option (or disabling/enabling
	  APM in your BIOS).

	  Some other things you should try when experiencing seemingly random,
	  "weird" problems:

	  1) make sure that you have enough swap space and that it is
	  enabled.
	  2) pass the "no-hlt" option to the kernel
	  3) switch on floating point emulation in the kernel and pass
	  the "no387" option to the kernel
	  4) pass the "floppy=nodma" option to the kernel
	  5) pass the "mem=4M" option to the kernel (thereby disabling
	  all but the first 4 MB of RAM)
	  6) make sure that the CPU is not over clocked.
	  7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/>
	  8) disable the cache from your BIOS settings
	  9) install a fan for the video card or exchange video RAM
	  10) install a better fan for the CPU
	  11) exchange RAM chips
	  12) exchange the motherboard.

	  To compile this driver as a module, choose M here: the
	  module will be called apm.

if APM

config APM_IGNORE_USER_SUSPEND
	bool "Ignore USER SUSPEND"
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	---help---
2435 2436 2437 2438 2439 2440 2441 2442 2443 2444 2445 2446 2447 2448 2449 2450 2451 2452 2453 2454 2455 2456
	  This option will ignore USER SUSPEND requests. On machines with a
	  compliant APM BIOS, you want to say N. However, on the NEC Versa M
	  series notebooks, it is necessary to say Y because of a BIOS bug.

config APM_DO_ENABLE
	bool "Enable PM at boot time"
	---help---
	  Enable APM features at boot time. From page 36 of the APM BIOS
	  specification: "When disabled, the APM BIOS does not automatically
	  power manage devices, enter the Standby State, enter the Suspend
	  State, or take power saving steps in response to CPU Idle calls."
	  This driver will make CPU Idle calls when Linux is idle (unless this
	  feature is turned off -- see "Do CPU IDLE calls", below). This
	  should always save battery power, but more complicated APM features
	  will be dependent on your BIOS implementation. You may need to turn
	  this option off if your computer hangs at boot time when using APM
	  support, or if it beeps continuously instead of suspending. Turn
	  this off if you have a NEC UltraLite Versa 33/C or a Toshiba
	  T400CDT. This is off by default since most machines do fine without
	  this feature.

config APM_CPU_IDLE
2457
	depends on CPU_IDLE
2458
	bool "Make CPU Idle calls when idle"
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2459
	---help---
2460 2461 2462 2463 2464 2465 2466 2467 2468 2469
	  Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop.
	  On some machines, this can activate improved power savings, such as
	  a slowed CPU clock rate, when the machine is idle. These idle calls
	  are made after the idle loop has run for some length of time (e.g.,
	  333 mS). On some machines, this will cause a hang at boot time or
	  whenever the CPU becomes idle. (On machines with more than one CPU,
	  this option does nothing.)

config APM_DISPLAY_BLANK
	bool "Enable console blanking using APM"
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2470
	---help---
2471 2472 2473 2474 2475 2476 2477 2478 2479 2480 2481 2482
	  Enable console blanking using the APM. Some laptops can use this to
	  turn off the LCD backlight when the screen blanker of the Linux
	  virtual console blanks the screen. Note that this is only used by
	  the virtual console screen blanker, and won't turn off the backlight
	  when using the X Window system. This also doesn't have anything to
	  do with your VESA-compliant power-saving monitor. Further, this
	  option doesn't work for all laptops -- it might not turn off your
	  backlight at all, or it might print a lot of errors to the console,
	  especially if you are using gpm.

config APM_ALLOW_INTS
	bool "Allow interrupts during APM BIOS calls"
I
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2483
	---help---
2484 2485 2486 2487 2488 2489 2490 2491 2492
	  Normally we disable external interrupts while we are making calls to
	  the APM BIOS as a measure to lessen the effects of a badly behaving
	  BIOS implementation.  The BIOS should reenable interrupts if it
	  needs to.  Unfortunately, some BIOSes do not -- especially those in
	  many of the newer IBM Thinkpads.  If you experience hangs when you
	  suspend, try setting this to Y.  Otherwise, say N.

endif # APM

2493
source "drivers/cpufreq/Kconfig"
2494 2495 2496

source "drivers/cpuidle/Kconfig"

A
Andy Henroid 已提交
2497 2498
source "drivers/idle/Kconfig"

2499 2500 2501 2502 2503 2504
endmenu


menu "Bus options (PCI etc.)"

config PCI
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2505
	bool "PCI support"
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2506
	default y
I
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2507
	---help---
2508 2509 2510 2511 2512 2513 2514
	  Find out whether you have a PCI motherboard. PCI is the name of a
	  bus system, i.e. the way the CPU talks to the other stuff inside
	  your box. Other bus systems are ISA, EISA, MicroChannel (MCA) or
	  VESA. If you have PCI, say Y, otherwise N.

choice
	prompt "PCI access mode"
2515
	depends on X86_32 && PCI
2516 2517 2518 2519 2520 2521 2522 2523 2524 2525 2526 2527 2528 2529 2530 2531 2532 2533 2534 2535 2536 2537 2538 2539 2540
	default PCI_GOANY
	---help---
	  On PCI systems, the BIOS can be used to detect the PCI devices and
	  determine their configuration. However, some old PCI motherboards
	  have BIOS bugs and may crash if this is done. Also, some embedded
	  PCI-based systems don't have any BIOS at all. Linux can also try to
	  detect the PCI hardware directly without using the BIOS.

	  With this option, you can specify how Linux should detect the
	  PCI devices. If you choose "BIOS", the BIOS will be used,
	  if you choose "Direct", the BIOS won't be used, and if you
	  choose "MMConfig", then PCI Express MMCONFIG will be used.
	  If you choose "Any", the kernel will try MMCONFIG, then the
	  direct access method and falls back to the BIOS if that doesn't
	  work. If unsure, go with the default, which is "Any".

config PCI_GOBIOS
	bool "BIOS"

config PCI_GOMMCONFIG
	bool "MMConfig"

config PCI_GODIRECT
	bool "Direct"

2541
config PCI_GOOLPC
2542
	bool "OLPC XO-1"
2543 2544
	depends on OLPC

2545 2546 2547
config PCI_GOANY
	bool "Any"

2548 2549 2550
endchoice

config PCI_BIOS
2551
	def_bool y
2552
	depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY)
2553 2554 2555

# x86-64 doesn't support PCI BIOS access from long mode so always go direct.
config PCI_DIRECT
2556
	def_bool y
2557
	depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC || PCI_GOMMCONFIG))
2558 2559

config PCI_MMCONFIG
2560
	def_bool y
F
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2561
	depends on X86_32 && PCI && (ACPI || SFI) && (PCI_GOMMCONFIG || PCI_GOANY)
2562

2563
config PCI_OLPC
2564 2565
	def_bool y
	depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY)
2566

2567 2568 2569 2570 2571
config PCI_XEN
	def_bool y
	depends on PCI && XEN
	select SWIOTLB_XEN

2572
config PCI_DOMAINS
2573
	def_bool y
2574 2575 2576 2577 2578 2579
	depends on PCI

config PCI_MMCONFIG
	bool "Support mmconfig PCI config space access"
	depends on X86_64 && PCI && ACPI

2580
config PCI_CNB20LE_QUIRK
2581
	bool "Read CNB20LE Host Bridge Windows" if EXPERT
2582
	depends on PCI
2583 2584 2585 2586 2587
	help
	  Read the PCI windows out of the CNB20LE host bridge. This allows
	  PCI hotplug to work on systems with the CNB20LE chipset which do
	  not have ACPI.

2588 2589 2590 2591 2592
	  There's no public spec for this chipset, and this functionality
	  is known to be incomplete.

	  You should say N unless you know you need this.

2593 2594
source "drivers/pci/Kconfig"

2595 2596 2597 2598 2599 2600 2601 2602 2603
config ISA_BUS
	bool "ISA-style bus support on modern systems" if EXPERT
	select ISA_BUS_API
	help
	  Enables ISA-style drivers on modern systems. This is necessary to
	  support PC/104 devices on X86_64 platforms.

	  If unsure, say N.

2604
# x86_64 have no ISA slots, but can have ISA-style DMA.
2605
config ISA_DMA_API
2606 2607 2608 2609 2610
	bool "ISA-style DMA support" if (X86_64 && EXPERT)
	default y
	help
	  Enables ISA-style DMA support for devices requiring such controllers.
	  If unsure, say Y.
2611

2612 2613
if X86_32

2614 2615
config ISA
	bool "ISA support"
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2616
	---help---
2617 2618 2619 2620 2621 2622 2623 2624 2625 2626 2627 2628 2629 2630 2631 2632 2633 2634 2635 2636 2637 2638 2639 2640 2641 2642
	  Find out whether you have ISA slots on your motherboard.  ISA is the
	  name of a bus system, i.e. the way the CPU talks to the other stuff
	  inside your box.  Other bus systems are PCI, EISA, MicroChannel
	  (MCA) or VESA.  ISA is an older system, now being displaced by PCI;
	  newer boards don't support it.  If you have ISA, say Y, otherwise N.

config EISA
	bool "EISA support"
	depends on ISA
	---help---
	  The Extended Industry Standard Architecture (EISA) bus was
	  developed as an open alternative to the IBM MicroChannel bus.

	  The EISA bus provided some of the features of the IBM MicroChannel
	  bus while maintaining backward compatibility with cards made for
	  the older ISA bus.  The EISA bus saw limited use between 1988 and
	  1995 when it was made obsolete by the PCI bus.

	  Say Y here if you are building a kernel for an EISA-based machine.

	  Otherwise, say N.

source "drivers/eisa/Kconfig"

config SCx200
	tristate "NatSemi SCx200 support"
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2643
	---help---
2644 2645 2646 2647 2648 2649 2650 2651 2652
	  This provides basic support for National Semiconductor's
	  (now AMD's) Geode processors.  The driver probes for the
	  PCI-IDs of several on-chip devices, so its a good dependency
	  for other scx200_* drivers.

	  If compiled as a module, the driver is named scx200.

config SCx200HR_TIMER
	tristate "NatSemi SCx200 27MHz High-Resolution Timer Support"
J
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2653
	depends on SCx200
2654
	default y
I
Ingo Molnar 已提交
2655
	---help---
2656 2657 2658 2659 2660 2661
	  This driver provides a clocksource built upon the on-chip
	  27MHz high-resolution timer.  Its also a workaround for
	  NSC Geode SC-1100's buggy TSC, which loses time when the
	  processor goes idle (as is done by the scheduler).  The
	  other workaround is idle=poll boot option.

2662 2663
config OLPC
	bool "One Laptop Per Child support"
2664
	depends on !X86_PAE
2665
	select GPIOLIB
2666
	select OF
2667
	select OF_PROMTREE
2668
	select IRQ_DOMAIN
I
Ingo Molnar 已提交
2669
	---help---
2670 2671 2672
	  Add support for detecting the unique features of the OLPC
	  XO hardware.

2673 2674
config OLPC_XO1_PM
	bool "OLPC XO-1 Power Management"
2675
	depends on OLPC && MFD_CS5535 && PM_SLEEP
2676
	select MFD_CORE
2677
	---help---
2678
	  Add support for poweroff and suspend of the OLPC XO-1 laptop.
2679

D
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2680 2681 2682 2683 2684 2685 2686
config OLPC_XO1_RTC
	bool "OLPC XO-1 Real Time Clock"
	depends on OLPC_XO1_PM && RTC_DRV_CMOS
	---help---
	  Add support for the XO-1 real time clock, which can be used as a
	  programmable wakeup source.

2687 2688
config OLPC_XO1_SCI
	bool "OLPC XO-1 SCI extras"
2689
	depends on OLPC && OLPC_XO1_PM
2690
	depends on INPUT=y
2691
	select POWER_SUPPLY
2692 2693 2694 2695
	select GPIO_CS5535
	select MFD_CORE
	---help---
	  Add support for SCI-based features of the OLPC XO-1 laptop:
2696
	   - EC-driven system wakeups
2697
	   - Power button
2698
	   - Ebook switch
2699
	   - Lid switch
2700 2701
	   - AC adapter status updates
	   - Battery status updates
2702

D
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2703 2704
config OLPC_XO15_SCI
	bool "OLPC XO-1.5 SCI extras"
2705 2706
	depends on OLPC && ACPI
	select POWER_SUPPLY
D
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2707 2708 2709 2710 2711
	---help---
	  Add support for SCI-based features of the OLPC XO-1.5 laptop:
	   - EC-driven system wakeups
	   - AC adapter status updates
	   - Battery status updates
2712

2713 2714 2715 2716 2717 2718 2719 2720 2721 2722 2723 2724 2725 2726
config ALIX
	bool "PCEngines ALIX System Support (LED setup)"
	select GPIOLIB
	---help---
	  This option enables system support for the PCEngines ALIX.
	  At present this just sets up LEDs for GPIO control on
	  ALIX2/3/6 boards.  However, other system specific setup should
	  get added here.

	  Note: You must still enable the drivers for GPIO and LED support
	  (GPIO_CS5535 & LEDS_GPIO) to actually use the LEDs

	  Note: You have to set alix.force=1 for boards with Award BIOS.

2727 2728 2729 2730 2731 2732
config NET5501
	bool "Soekris Engineering net5501 System Support (LEDS, GPIO, etc)"
	select GPIOLIB
	---help---
	  This option enables system support for the Soekris Engineering net5501.

2733 2734 2735 2736 2737 2738 2739
config GEOS
	bool "Traverse Technologies GEOS System Support (LEDS, GPIO, etc)"
	select GPIOLIB
	depends on DMI
	---help---
	  This option enables system support for the Traverse Technologies GEOS.

2740 2741 2742 2743 2744 2745 2746 2747 2748
config TS5500
	bool "Technologic Systems TS-5500 platform support"
	depends on MELAN
	select CHECK_SIGNATURE
	select NEW_LEDS
	select LEDS_CLASS
	---help---
	  This option enables system support for the Technologic Systems TS-5500.

2749 2750
endif # X86_32

2751
config AMD_NB
2752
	def_bool y
2753
	depends on CPU_SUP_AMD && PCI
2754 2755 2756

source "drivers/pcmcia/Kconfig"

2757
config RAPIDIO
2758
	tristate "RapidIO support"
2759 2760 2761
	depends on PCI
	default n
	help
2762
	  If enabled this option will include drivers and the core
2763 2764 2765 2766
	  infrastructure code to support RapidIO interconnect devices.

source "drivers/rapidio/Kconfig"

2767 2768 2769 2770 2771 2772 2773 2774 2775 2776 2777 2778 2779 2780 2781 2782 2783 2784 2785 2786 2787 2788 2789 2790 2791 2792
config X86_SYSFB
	bool "Mark VGA/VBE/EFI FB as generic system framebuffer"
	help
	  Firmwares often provide initial graphics framebuffers so the BIOS,
	  bootloader or kernel can show basic video-output during boot for
	  user-guidance and debugging. Historically, x86 used the VESA BIOS
	  Extensions and EFI-framebuffers for this, which are mostly limited
	  to x86.
	  This option, if enabled, marks VGA/VBE/EFI framebuffers as generic
	  framebuffers so the new generic system-framebuffer drivers can be
	  used on x86. If the framebuffer is not compatible with the generic
	  modes, it is adverticed as fallback platform framebuffer so legacy
	  drivers like efifb, vesafb and uvesafb can pick it up.
	  If this option is not selected, all system framebuffers are always
	  marked as fallback platform framebuffers as usual.

	  Note: Legacy fbdev drivers, including vesafb, efifb, uvesafb, will
	  not be able to pick up generic system framebuffers if this option
	  is selected. You are highly encouraged to enable simplefb as
	  replacement if you select this option. simplefb can correctly deal
	  with generic system framebuffers. But you should still keep vesafb
	  and others enabled as fallback if a system framebuffer is
	  incompatible with simplefb.

	  If unsure, say Y.

2793 2794 2795 2796 2797 2798 2799 2800 2801 2802
endmenu


menu "Executable file formats / Emulations"

source "fs/Kconfig.binfmt"

config IA32_EMULATION
	bool "IA32 Emulation"
	depends on X86_64
2803
	select ARCH_WANT_OLD_COMPAT_IPC
2804
	select BINFMT_ELF
R
Roland McGrath 已提交
2805
	select COMPAT_BINFMT_ELF
2806
	select COMPAT_OLD_SIGACTION
I
Ingo Molnar 已提交
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	---help---
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H. J. Lu 已提交
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	  Include code to run legacy 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.
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config IA32_AOUT
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	tristate "IA32 a.out support"
	depends on IA32_EMULATION
	---help---
	  Support old a.out binaries in the 32bit emulation.
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config X86_X32
2819
	bool "x32 ABI for 64-bit mode"
2820
	depends on X86_64
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H. J. Lu 已提交
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	---help---
	  Include code to run binaries for the x32 native 32-bit ABI
	  for 64-bit processors.  An x32 process gets access to the
	  full 64-bit register file and wide data path while leaving
	  pointers at 32 bits for smaller memory footprint.

	  You will need a recent binutils (2.22 or later) with
	  elf32_x86_64 support enabled to compile a kernel with this
	  option set.

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config COMPAT_32
	def_bool y
	depends on IA32_EMULATION || X86_32
	select HAVE_UID16
	select OLD_SIGSUSPEND3

2837
config COMPAT
2838
	def_bool y
2839
	depends on IA32_EMULATION || X86_X32
2840

2841
if COMPAT
2842
config COMPAT_FOR_U64_ALIGNMENT
2843
	def_bool y
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config SYSVIPC_COMPAT
2846
	def_bool y
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	depends on SYSVIPC
endif
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endmenu


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config HAVE_ATOMIC_IOMAP
	def_bool y
	depends on X86_32

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config X86_DEV_DMA_OPS
	bool
2859
	depends on X86_64 || STA2X11
2860

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config X86_DMA_REMAP
	bool
2863
	depends on STA2X11
2864

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config HAVE_GENERIC_GUP
	def_bool y

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source "net/Kconfig"

source "drivers/Kconfig"

source "drivers/firmware/Kconfig"

source "fs/Kconfig"

source "arch/x86/Kconfig.debug"

source "security/Kconfig"

source "crypto/Kconfig"

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source "arch/x86/kvm/Kconfig"

2884
source "lib/Kconfig"