Kconfig 94.3 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
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	select NEED_DMA_MAP_STATE
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	select SWIOTLB
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	select X86_DEV_DMA_OPS
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	select ARCH_HAS_SYSCALL_WRAPPER
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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_FILTER_PGPROT
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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_MEMBARRIER_SYNC_CORE
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	select ARCH_HAS_PMEM_API		if X86_64
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	select ARCH_HAS_REFCOUNT
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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_SYNC_CORE_BEFORE_USERMODE
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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
	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 DMA_DIRECT_OPS
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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_MATRIX_ALLOCATOR	if X86_LOCAL_APIC
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	select GENERIC_IRQ_MIGRATION		if SMP
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	select GENERIC_IRQ_PROBE
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	select GENERIC_IRQ_RESERVATION_MODE
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	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
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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
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	select HAVE_ARCH_THREAD_STRUCT_WHITELIST
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	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_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
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	select HAVE_FUNCTION_ERROR_INJECTION
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	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 NEED_SG_DMA_LENGTH
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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

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 ARCH_HAS_FILTER_PGPROT
	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_NONE
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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_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 GOLDFISH
       def_bool y
       depends on X86_GOLDFISH

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config RETPOLINE
	bool "Avoid speculative indirect branches in kernel"
	default y
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	select STACK_VALIDATION if HAVE_STACK_VALIDATION
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	help
	  Compile kernel with the retpoline compiler options to guard against
	  kernel-to-user data leaks by avoiding speculative indirect
	  branches. Requires a compiler with -mindirect-branch=thunk-extern
	  support for full protection. The kernel may run slower.

	  Without compiler support, at least indirect branches in assembler
	  code are eliminated. Since this includes the syscall entry path,
	  it is not entirely pointless.

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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_BIGSMP
	bool "Support for big SMP systems with more than 8 CPUs"
	depends on SMP
	---help---
	  This option is needed for the systems that have more than 8 CPUs

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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
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	  things like clock tree (common clock framework) and pincontrol
	  which are needed by the LPSS peripheral drivers.
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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.

635 636 637 638 639 640 641 642 643 644 645 646 647
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.

648 649
config X86_RDC321X
	bool "RDC R-321x SoC"
650
	depends on X86_32
651 652 653 654 655 656 657 658
	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.

659
config X86_32_NON_STANDARD
660 661
	bool "Support non-standard 32-bit SMP architectures"
	depends on X86_32 && SMP
662
	depends on X86_EXTENDED_PLATFORM
663
	---help---
664 665 666 667
	  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.
668

669
# Alphabetically sorted list of Non standard 32 bit platforms
670

671
config X86_SUPPORTS_MEMORY_FAILURE
672
	def_bool y
673 674 675 676 677 678 679
	# 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

680 681 682
config STA2X11
	bool "STA2X11 Companion Chip Support"
	depends on X86_32_NON_STANDARD && PCI
683
	select ARCH_HAS_PHYS_TO_DMA
684 685 686 687
	select X86_DEV_DMA_OPS
	select X86_DMA_REMAP
	select SWIOTLB
	select MFD_STA2X11
688
	select GPIOLIB
689 690 691 692 693 694 695 696
	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.

697 698 699 700 701 702 703 704 705 706 707 708 709
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.

710
config SCHED_OMIT_FRAME_POINTER
711 712
	def_bool y
	prompt "Single-depth WCHAN output"
713
	depends on X86
714
	---help---
715 716 717 718 719 720 721
	  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".

722 723
menuconfig HYPERVISOR_GUEST
	bool "Linux guest support"
724
	---help---
725 726 727
	  Say Y here to enable options for running Linux under various hyper-
	  visors. This option enables basic hypervisor detection and platform
	  setup.
728

729 730
	  If you say N, all options in this submenu will be skipped and
	  disabled, and Linux guest support won't be built in.
731

732
if HYPERVISOR_GUEST
733

734 735
config PARAVIRT
	bool "Enable paravirtualization code"
736
	---help---
737 738 739 740 741
	  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.

742 743 744 745 746 747 748
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.

749 750
config PARAVIRT_SPINLOCKS
	bool "Paravirtualization layer for spinlocks"
751
	depends on PARAVIRT && SMP
752 753 754 755 756
	---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).

757 758
	  It has a minimal impact on native kernels and gives a nice performance
	  benefit on paravirtualized KVM / Xen kernels.
759

760
	  If you are unsure how to answer this question, answer Y.
761

762 763
config QUEUED_LOCK_STAT
	bool "Paravirt queued spinlock statistics"
764
	depends on PARAVIRT_SPINLOCKS && DEBUG_FS
765 766 767 768 769
	---help---
	  Enable the collection of statistical data on the slowpath
	  behavior of paravirtualized queued spinlocks and report
	  them on debugfs.

770
source "arch/x86/xen/Kconfig"
771

772 773 774 775 776
config KVM_GUEST
	bool "KVM Guest support (including kvmclock)"
	depends on PARAVIRT
	select PARAVIRT_CLOCK
	default y
777
	---help---
778 779 780 781 782
	  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
783

784 785 786 787 788 789 790 791 792
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.

793 794 795 796
config PARAVIRT_TIME_ACCOUNTING
	bool "Paravirtual steal time accounting"
	depends on PARAVIRT
	default n
797
	---help---
798 799 800 801 802 803 804 805 806
	  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
807

808 809
config JAILHOUSE_GUEST
	bool "Jailhouse non-root cell support"
810
	depends on X86_64 && PCI
811
	select X86_PM_TIMER
812 813 814 815 816
	---help---
	  This option allows to run Linux as guest in a Jailhouse non-root
	  cell. You can leave this option disabled if you only want to start
	  Jailhouse and run Linux afterwards in the root cell.

817
endif #HYPERVISOR_GUEST
818

819
config NO_BOOTMEM
Y
Yinghai Lu 已提交
820
	def_bool y
821

822 823 824
source "arch/x86/Kconfig.cpu"

config HPET_TIMER
825
	def_bool X86_64
826
	prompt "HPET Timer Support" if X86_32
827 828 829 830 831 832 833
	---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,
834 835
	  as it is off-chip.  The interface used is documented
	  in the HPET spec, revision 1.
836

837 838 839
	  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.
840

841
	  Choose N to continue using the legacy 8254 timer.
842 843

config HPET_EMULATE_RTC
844
	def_bool y
845
	depends on HPET_TIMER && (RTC=y || RTC=m || RTC_DRV_CMOS=m || RTC_DRV_CMOS=y)
846

847
config APB_TIMER
848 849
       def_bool y if X86_INTEL_MID
       prompt "Intel MID APB Timer Support" if X86_INTEL_MID
850
       select DW_APB_TIMER
851
       depends on X86_INTEL_MID && SFI
852 853 854 855 856 857 858
       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.

859
# Mark as expert because too many people got it wrong.
860
# The code disables itself when not needed.
861 862
config DMI
	default y
863
	select DMI_SCAN_MACHINE_NON_EFI_FALLBACK
864
	bool "Enable DMI scanning" if EXPERT
865
	---help---
866 867 868 869 870
	  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.

871
config GART_IOMMU
872
	bool "Old AMD GART IOMMU support"
873
	select IOMMU_HELPER
874
	select SWIOTLB
875
	depends on X86_64 && PCI && AMD_NB
876
	---help---
877 878 879 880 881 882 883 884 885 886 887 888 889 890 891
	  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.
892 893 894

config CALGARY_IOMMU
	bool "IBM Calgary IOMMU support"
895
	select IOMMU_HELPER
896
	select SWIOTLB
897
	depends on X86_64 && PCI
898
	---help---
899 900 901 902 903 904 905 906 907 908 909 910 911 912
	  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
913 914
	def_bool y
	prompt "Should Calgary be enabled by default?"
915
	depends on CALGARY_IOMMU
916
	---help---
917 918 919 920 921 922
	  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.

923
config MAXSMP
924
	bool "Enable Maximum number of SMP Processors and NUMA Nodes"
925
	depends on X86_64 && SMP && DEBUG_KERNEL
M
Mike Travis 已提交
926
	select CPUMASK_OFFSTACK
927
	---help---
928
	  Enable maximum number of CPUS and NUMA Nodes for this architecture.
929
	  If unsure, say N.
930

931 932 933 934 935 936 937 938 939 940 941 942 943 944 945
#
# The maximum number of CPUs supported:
#
# The main config value is NR_CPUS, which defaults to NR_CPUS_DEFAULT,
# and which can be configured interactively in the
# [NR_CPUS_RANGE_BEGIN ... NR_CPUS_RANGE_END] range.
#
# The ranges are different on 32-bit and 64-bit kernels, depending on
# hardware capabilities and scalability features of the kernel.
#
# ( If MAXSMP is enabled we just use the highest possible value and disable
#   interactive configuration. )
#

config NR_CPUS_RANGE_BEGIN
946
	int
947 948 949
	default NR_CPUS_RANGE_END if MAXSMP
	default    1 if !SMP
	default    2
950

951
config NR_CPUS_RANGE_END
952
	int
953 954 955 956
	depends on X86_32
	default   64 if  SMP &&  X86_BIGSMP
	default    8 if  SMP && !X86_BIGSMP
	default    1 if !SMP
957

958
config NR_CPUS_RANGE_END
959
	int
960 961 962 963
	depends on X86_64
	default 8192 if  SMP && ( MAXSMP ||  CPUMASK_OFFSTACK)
	default  512 if  SMP && (!MAXSMP && !CPUMASK_OFFSTACK)
	default    1 if !SMP
964

965
config NR_CPUS_DEFAULT
966 967
	int
	depends on X86_32
968 969 970
	default   32 if  X86_BIGSMP
	default    8 if  SMP
	default    1 if !SMP
971

972
config NR_CPUS_DEFAULT
973 974
	int
	depends on X86_64
975 976 977
	default 8192 if  MAXSMP
	default   64 if  SMP
	default    1 if !SMP
978

979
config NR_CPUS
M
Mike Travis 已提交
980
	int "Maximum number of CPUs" if SMP && !MAXSMP
981 982
	range NR_CPUS_RANGE_BEGIN NR_CPUS_RANGE_END
	default NR_CPUS_DEFAULT
983
	---help---
984
	  This allows you to specify the maximum number of CPUs which this
985
	  kernel will support.  If CPUMASK_OFFSTACK is enabled, the maximum
986
	  supported value is 8192, otherwise the maximum value is 512.  The
987 988
	  minimum value which makes sense is 2.

989 990
	  This is purely to save memory: each supported CPU adds about 8KB
	  to the kernel image.
991 992 993

config SCHED_SMT
	bool "SMT (Hyperthreading) scheduler support"
994
	depends on SMP
995
	---help---
996 997 998 999 1000 1001
	  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
1002 1003
	def_bool y
	prompt "Multi-core scheduler support"
1004
	depends on SMP
1005
	---help---
1006 1007 1008 1009
	  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.

1010 1011
config SCHED_MC_PRIO
	bool "CPU core priorities scheduler support"
1012 1013 1014
	depends on SCHED_MC && CPU_SUP_INTEL
	select X86_INTEL_PSTATE
	select CPU_FREQ
1015
	default y
1016
	---help---
1017 1018 1019 1020
	  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.
1021

1022 1023 1024 1025
	  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.
1026

1027
	  This feature will have no effect on CPUs without this feature.
1028

1029
	  If unsure say Y here.
1030

1031 1032
source "kernel/Kconfig.preempt"

1033 1034
config UP_LATE_INIT
       def_bool y
1035
       depends on !SMP && X86_LOCAL_APIC
1036

1037
config X86_UP_APIC
1038 1039
	bool "Local APIC support on uniprocessors" if !PCI_MSI
	default PCI_MSI
1040
	depends on X86_32 && !SMP && !X86_32_NON_STANDARD
1041
	---help---
1042 1043 1044 1045 1046 1047 1048 1049 1050 1051 1052 1053
	  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
1054
	---help---
1055 1056 1057 1058 1059 1060 1061 1062 1063
	  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
1064
	def_bool y
1065
	depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC || PCI_MSI
1066
	select IRQ_DOMAIN_HIERARCHY
1067
	select PCI_MSI_IRQ_DOMAIN if PCI_MSI
1068 1069

config X86_IO_APIC
1070 1071
	def_bool y
	depends on X86_LOCAL_APIC || X86_UP_IOAPIC
1072

1073 1074 1075
config X86_REROUTE_FOR_BROKEN_BOOT_IRQS
	bool "Reroute for broken boot IRQs"
	depends on X86_IO_APIC
1076
	---help---
1077 1078 1079 1080 1081 1082 1083 1084 1085 1086 1087 1088 1089 1090 1091 1092 1093 1094 1095
	  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.

1096
config X86_MCE
1097
	bool "Machine Check / overheating reporting"
1098
	select GENERIC_ALLOCATOR
1099
	default y
1100
	---help---
1101 1102
	  Machine Check support allows the processor to notify the
	  kernel if it detects a problem (e.g. overheating, data corruption).
1103
	  The action the kernel takes depends on the severity of the problem,
1104
	  ranging from warning messages to halting the machine.
1105

1106 1107 1108 1109 1110 1111 1112 1113
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.

1114
config X86_MCE_INTEL
1115 1116
	def_bool y
	prompt "Intel MCE features"
1117
	depends on X86_MCE && X86_LOCAL_APIC
1118
	---help---
1119 1120 1121 1122
	   Additional support for intel specific MCE features such as
	   the thermal monitor.

config X86_MCE_AMD
1123 1124
	def_bool y
	prompt "AMD MCE features"
1125
	depends on X86_MCE && X86_LOCAL_APIC && AMD_NB
1126
	---help---
1127 1128 1129
	   Additional support for AMD specific MCE features such as
	   the DRAM Error Threshold.

1130
config X86_ANCIENT_MCE
1131
	bool "Support for old Pentium 5 / WinChip machine checks"
1132
	depends on X86_32 && X86_MCE
1133 1134
	---help---
	  Include support for machine check handling on old Pentium 5 or WinChip
1135
	  systems. These typically need to be enabled explicitly on the command
1136
	  line.
1137

1138 1139
config X86_MCE_THRESHOLD
	depends on X86_MCE_AMD || X86_MCE_INTEL
1140
	def_bool y
1141

1142
config X86_MCE_INJECT
1143
	depends on X86_MCE && X86_LOCAL_APIC && DEBUG_FS
1144 1145 1146 1147 1148 1149
	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.

1150 1151
config X86_THERMAL_VECTOR
	def_bool y
1152
	depends on X86_MCE_INTEL
1153

1154
source "arch/x86/events/Kconfig"
1155

1156
config X86_LEGACY_VM86
1157
	bool "Legacy VM86 support"
1158
	default n
1159
	depends on X86_32
1160
	---help---
1161 1162 1163 1164 1165 1166 1167 1168
	  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
1169 1170 1171 1172
	  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.
1173

1174 1175 1176 1177
	  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.
1178

1179 1180
	  Enabling this option increases the complexity of the kernel
	  and slows down exception handling a tiny bit.
1181

1182
	  If unsure, say N here.
1183 1184 1185 1186

config VM86
       bool
       default X86_LEGACY_VM86
1187 1188 1189 1190

config X86_16BIT
	bool "Enable support for 16-bit segments" if EXPERT
	default y
1191
	depends on MODIFY_LDT_SYSCALL
1192 1193 1194 1195 1196 1197 1198 1199 1200
	---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
1201

1202 1203
config X86_ESPFIX64
	def_bool y
1204
	depends on X86_16BIT && X86_64
1205

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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.

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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
1241
	tristate "Dell i8k legacy laptop support"
1242
	select HWMON
1243
	select SENSORS_DELL_SMM
1244
	---help---
1245 1246 1247 1248 1249 1250 1251 1252 1253
	  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.
1254 1255 1256
	  Say N otherwise.

config X86_REBOOTFIXUPS
1257 1258
	bool "Enable X86 board specific fixups for reboot"
	depends on X86_32
1259 1260 1261 1262 1263 1264 1265 1266
	---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
1267
	  CS5530A and CS5536 chipsets and the RDC R-321x SoC.
1268 1269 1270 1271 1272 1273

	  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
1274 1275
	bool "CPU microcode loading support"
	default y
1276
	depends on CPU_SUP_AMD || CPU_SUP_INTEL
1277 1278 1279
	select FW_LOADER
	---help---
	  If you say Y here, you will be able to update the microcode on
1280 1281 1282 1283 1284 1285 1286
	  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
1287
	  in Documentation/x86/microcode.txt. For that you need to enable
1288 1289 1290
	  CONFIG_BLK_DEV_INITRD in order for the loader to be able to scan the
	  initrd for microcode blobs.

1291 1292 1293
	  In addition, you can build the microcode into the kernel. For that you
	  need to add the vendor-supplied microcode to the CONFIG_EXTRA_FIRMWARE
	  config option.
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Peter Oruba 已提交
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config MICROCODE_INTEL
1296
	bool "Intel microcode loading support"
1297 1298 1299 1300 1301 1302 1303
	depends on MICROCODE
	default MICROCODE
	select FW_LOADER
	---help---
	  This options enables microcode patch loading support for Intel
	  processors.

1304 1305 1306
	  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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1308
config MICROCODE_AMD
1309
	bool "AMD microcode loading support"
1310 1311 1312 1313 1314
	depends on MICROCODE
	select FW_LOADER
	---help---
	  If you select this option, microcode patch loading support for AMD
	  processors will be enabled.
1315

1316
config MICROCODE_OLD_INTERFACE
1317
	def_bool y
1318 1319 1320 1321
	depends on MICROCODE

config X86_MSR
	tristate "/dev/cpu/*/msr - Model-specific register support"
1322
	---help---
1323 1324 1325 1326 1327 1328 1329 1330
	  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"
1331
	---help---
1332 1333 1334 1335 1336 1337 1338
	  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"
1339
	default HIGHMEM4G
1340 1341 1342 1343 1344 1345 1346 1347 1348 1349 1350 1351 1352 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
	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"
1380
	---help---
1381 1382 1383 1384 1385
	  Select this if you have a 32-bit processor and between 1 and 4
	  gigabytes of physical RAM.

config HIGHMEM64G
	bool "64GB"
1386
	depends on !M486 && !M586 && !M586TSC && !M586MMX && !MGEODE_LX && !MGEODEGX1 && !MCYRIXIII && !MELAN && !MWINCHIPC6 && !WINCHIP3D && !MK6
1387
	select X86_PAE
1388
	---help---
1389 1390 1391 1392 1393 1394
	  Select this if you have a 32-bit processor and more than 4
	  gigabytes of physical RAM.

endchoice

choice
1395
	prompt "Memory split" if EXPERT
1396 1397
	default VMSPLIT_3G
	depends on X86_32
1398
	---help---
1399 1400 1401 1402 1403 1404 1405 1406 1407 1408 1409 1410 1411 1412 1413 1414 1415 1416 1417 1418 1419 1420 1421 1422 1423 1424 1425 1426 1427 1428 1429 1430 1431 1432 1433 1434 1435 1436 1437
	  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
1438
	def_bool y
1439 1440 1441
	depends on X86_32 && (HIGHMEM64G || HIGHMEM4G)

config X86_PAE
1442
	bool "PAE (Physical Address Extension) Support"
1443
	depends on X86_32 && !HIGHMEM4G
1444
	select PHYS_ADDR_T_64BIT
1445
	select SWIOTLB
1446
	---help---
1447 1448 1449 1450 1451
	  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.

1452 1453
config X86_5LEVEL
	bool "Enable 5-level page tables support"
1454
	select DYNAMIC_MEMORY_LAYOUT
1455
	select SPARSEMEM_VMEMMAP
1456 1457 1458 1459 1460 1461 1462 1463
	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.

1464 1465
	  A kernel with the option enabled can be booted on machines that
	  support 4- or 5-level paging.
1466 1467 1468 1469 1470 1471

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

	  Say N if unsure.

1472
config X86_DIRECT_GBPAGES
1473
	def_bool y
1474
	depends on X86_64 && !DEBUG_PAGEALLOC
1475
	---help---
1476 1477 1478 1479
	  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.
1480

1481 1482 1483 1484 1485 1486 1487 1488 1489 1490 1491 1492 1493 1494 1495 1496 1497 1498 1499 1500 1501 1502 1503 1504 1505
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.

1506 1507 1508 1509
config ARCH_USE_MEMREMAP_PROT
	def_bool y
	depends on AMD_MEM_ENCRYPT

1510 1511
# Common NUMA Features
config NUMA
1512
	bool "Numa Memory Allocation and Scheduler Support"
1513
	depends on SMP
1514 1515
	depends on X86_64 || (X86_32 && HIGHMEM64G && X86_BIGSMP)
	default y if X86_BIGSMP
1516
	---help---
1517
	  Enable NUMA (Non Uniform Memory Access) support.
1518

1519 1520 1521 1522
	  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.

1523
	  For 64-bit this is recommended if the system is Intel Core i7
1524 1525
	  (or later), AMD Opteron, or EM64T NUMA.

1526
	  For 32-bit this is only needed if you boot a 32-bit
1527
	  kernel on a 64-bit NUMA platform.
1528 1529

	  Otherwise, you should say N.
1530

1531
config AMD_NUMA
1532 1533
	def_bool y
	prompt "Old style AMD Opteron NUMA detection"
1534
	depends on X86_64 && NUMA && PCI
1535
	---help---
1536 1537 1538 1539 1540
	  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.
1541 1542

config X86_64_ACPI_NUMA
1543 1544
	def_bool y
	prompt "ACPI NUMA detection"
1545 1546
	depends on X86_64 && NUMA && ACPI && PCI
	select ACPI_NUMA
1547
	---help---
1548 1549
	  Enable ACPI SRAT based node topology detection.

1550 1551 1552 1553 1554 1555 1556 1557 1558
# 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

1559 1560
config NUMA_EMU
	bool "NUMA emulation"
1561
	depends on NUMA
1562
	---help---
1563 1564 1565 1566 1567
	  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
1568
	int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP
1569 1570
	range 1 10
	default "10" if MAXSMP
1571 1572 1573
	default "6" if X86_64
	default "3"
	depends on NEED_MULTIPLE_NODES
1574
	---help---
1575
	  Specify the maximum number of NUMA Nodes available on the target
1576
	  system.  Increases memory reserved to accommodate various tables.
1577 1578

config ARCH_HAVE_MEMORY_PRESENT
1579
	def_bool y
1580 1581 1582 1583
	depends on X86_32 && DISCONTIGMEM

config ARCH_FLATMEM_ENABLE
	def_bool y
1584
	depends on X86_32 && !NUMA
1585 1586 1587

config ARCH_DISCONTIGMEM_ENABLE
	def_bool y
1588
	depends on NUMA && X86_32
1589 1590 1591

config ARCH_DISCONTIGMEM_DEFAULT
	def_bool y
1592 1593
	depends on NUMA && X86_32

1594 1595
config ARCH_SPARSEMEM_ENABLE
	def_bool y
1596
	depends on X86_64 || NUMA || X86_32 || X86_32_NON_STANDARD
1597 1598 1599
	select SPARSEMEM_STATIC if X86_32
	select SPARSEMEM_VMEMMAP_ENABLE if X86_64

1600 1601 1602 1603
config ARCH_SPARSEMEM_DEFAULT
	def_bool y
	depends on X86_64

1604 1605
config ARCH_SELECT_MEMORY_MODEL
	def_bool y
1606
	depends on ARCH_SPARSEMEM_ENABLE
1607 1608

config ARCH_MEMORY_PROBE
1609
	bool "Enable sysfs memory/probe interface"
1610
	depends on X86_64 && MEMORY_HOTPLUG
1611 1612 1613 1614
	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.
1615

1616 1617 1618 1619
config ARCH_PROC_KCORE_TEXT
	def_bool y
	depends on X86_64 && PROC_KCORE

1620 1621 1622 1623 1624
config ILLEGAL_POINTER_VALUE
       hex
       default 0 if X86_32
       default 0xdead000000000000 if X86_64

1625 1626
source "mm/Kconfig"

1627 1628 1629
config X86_PMEM_LEGACY_DEVICE
	bool

1630
config X86_PMEM_LEGACY
1631
	tristate "Support non-standard NVDIMMs and ADR protected memory"
1632 1633
	depends on PHYS_ADDR_T_64BIT
	depends on BLK_DEV
1634
	select X86_PMEM_LEGACY_DEVICE
1635
	select LIBNVDIMM
1636 1637 1638 1639 1640 1641 1642 1643
	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.

1644 1645
config HIGHPTE
	bool "Allocate 3rd-level pagetables from highmem"
1646
	depends on HIGHMEM
1647
	---help---
1648 1649 1650 1651 1652
	  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.

1653
config X86_CHECK_BIOS_CORRUPTION
1654 1655 1656 1657 1658 1659 1660 1661 1662
	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
1663
	  Documentation/admin-guide/kernel-parameters.rst to adjust this.
1664 1665 1666 1667 1668 1669 1670 1671 1672 1673

	  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.
1674

1675
config X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK
1676
	bool "Set the default setting of memory_corruption_check"
1677 1678
	depends on X86_CHECK_BIOS_CORRUPTION
	default y
1679 1680 1681
	---help---
	  Set whether the default state of memory_corruption_check is
	  on or off.
1682

1683
config X86_RESERVE_LOW
1684 1685 1686
	int "Amount of low memory, in kilobytes, to reserve for the BIOS"
	default 64
	range 4 640
1687
	---help---
1688 1689 1690 1691 1692 1693 1694 1695 1696
	  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.
1697

1698 1699 1700 1701 1702
	  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.
1703

1704 1705 1706 1707 1708
	  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.
1709

1710
	  Leave this to the default value of 64 if you are unsure.
1711

1712 1713
config MATH_EMULATION
	bool
1714
	depends on MODIFY_LDT_SYSCALL
1715 1716 1717 1718 1719 1720 1721 1722 1723 1724 1725 1726 1727 1728 1729 1730 1731 1732 1733 1734 1735 1736 1737 1738 1739
	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
1740
	def_bool y
1741
	prompt "MTRR (Memory Type Range Register) support" if EXPERT
1742 1743 1744 1745 1746 1747 1748 1749 1750 1751 1752 1753 1754 1755 1756 1757 1758 1759 1760 1761 1762 1763 1764 1765 1766 1767 1768 1769 1770 1771
	---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.

1772
	  See <file:Documentation/x86/mtrr.txt> for more information.
1773

1774
config MTRR_SANITIZER
1775
	def_bool y
1776 1777
	prompt "MTRR cleanup support"
	depends on MTRR
1778
	---help---
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	  Convert MTRR layout from continuous to discrete, so X drivers can
	  add writeback entries.
1781

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	  Can be disabled with disable_mtrr_cleanup on the kernel command line.
1783
	  The largest mtrr entry size for a continuous block can be set with
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	  mtrr_chunk_size.
1785

1786
	  If unsure, say Y.
1787 1788

config MTRR_SANITIZER_ENABLE_DEFAULT
1789 1790 1791
	int "MTRR cleanup enable value (0-1)"
	range 0 1
	default "0"
1792
	depends on MTRR_SANITIZER
1793
	---help---
1794
	  Enable mtrr cleanup default value
1795

1796 1797 1798 1799 1800
config MTRR_SANITIZER_SPARE_REG_NR_DEFAULT
	int "MTRR cleanup spare reg num (0-7)"
	range 0 7
	default "1"
	depends on MTRR_SANITIZER
1801
	---help---
1802
	  mtrr cleanup spare entries default, it can be changed via
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1803
	  mtrr_spare_reg_nr=N on the kernel command line.
1804

1805
config X86_PAT
1806
	def_bool y
1807
	prompt "x86 PAT support" if EXPERT
1808
	depends on MTRR
1809
	---help---
1810
	  Use PAT attributes to setup page level cache control.
1811

1812 1813 1814 1815
	  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,
1816
	  spontaneous reboots) or a non-working video driver.
1817 1818 1819

	  If unsure, say Y.

1820 1821 1822 1823
config ARCH_USES_PG_UNCACHED
	def_bool y
	depends on X86_PAT

1824 1825 1826 1827 1828 1829 1830 1831 1832
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.

1833 1834 1835 1836 1837 1838 1839 1840 1841 1842 1843
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.

1844
config X86_INTEL_UMIP
1845
	def_bool y
1846 1847 1848 1849 1850
	depends on CPU_SUP_INTEL
	prompt "Intel User Mode Instruction Prevention" if EXPERT
	---help---
	  The User Mode Instruction Prevention (UMIP) is a security
	  feature in newer Intel processors. If enabled, a general
1851 1852 1853 1854 1855 1856 1857 1858
	  protection fault is issued if the SGDT, SLDT, SIDT, SMSW
	  or STR instructions are executed in user mode. These instructions
	  unnecessarily expose information about the hardware state.

	  The vast majority of applications do not use these instructions.
	  For the very few that do, software emulation is provided in
	  specific cases in protected and virtual-8086 modes. Emulated
	  results are dummy.
1859

1860 1861 1862
config X86_INTEL_MPX
	prompt "Intel MPX (Memory Protection Extensions)"
	def_bool n
1863 1864 1865
	# 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
1866 1867 1868 1869 1870 1871 1872 1873 1874 1875 1876 1877 1878 1879 1880 1881 1882 1883 1884 1885 1886 1887
	---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.

1888
config X86_INTEL_MEMORY_PROTECTION_KEYS
1889
	prompt "Intel Memory Protection Keys"
1890
	def_bool y
1891
	# Note: only available in 64-bit mode
1892
	depends on CPU_SUP_INTEL && X86_64
1893 1894
	select ARCH_USES_HIGH_VMA_FLAGS
	select ARCH_HAS_PKEYS
1895 1896 1897 1898 1899 1900 1901 1902
	---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.
1903

1904
config EFI
1905
	bool "EFI runtime service support"
1906
	depends on ACPI
1907
	select UCS2_STRING
1908
	select EFI_RUNTIME_WRAPPERS
1909
	---help---
1910 1911
	  This enables the kernel to use EFI runtime services that are
	  available (such as the EFI variable services).
1912

1913 1914 1915 1916 1917 1918
	  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.
1919

1920 1921
config EFI_STUB
       bool "EFI stub support"
1922
       depends on EFI && !X86_USE_3DNOW
1923
       select RELOCATABLE
1924 1925 1926 1927
       ---help---
          This kernel feature allows a bzImage to be loaded directly
	  by EFI firmware without the use of a bootloader.

1928
	  See Documentation/efi-stub.txt for more information.
1929

1930 1931 1932 1933 1934 1935 1936 1937 1938 1939 1940 1941 1942 1943
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.

1944
config SECCOMP
1945 1946
	def_bool y
	prompt "Enable seccomp to safely compute untrusted bytecode"
1947
	---help---
1948 1949 1950 1951 1952 1953
	  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
1954
	  enabled via prctl(PR_SET_SECCOMP), it cannot be disabled
1955 1956 1957 1958 1959 1960 1961 1962 1963
	  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"
1964
	select KEXEC_CORE
1965
	---help---
1966 1967 1968 1969 1970 1971 1972 1973 1974
	  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
1975 1976 1977
	  initially work for you.  As of this writing the exact hardware
	  interface is strongly in flux, so no good recommendation can be
	  made.
1978

1979 1980
config KEXEC_FILE
	bool "kexec file based system call"
1981
	select KEXEC_CORE
1982 1983 1984 1985 1986 1987 1988 1989 1990 1991
	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.

1992 1993 1994
config ARCH_HAS_KEXEC_PURGATORY
	def_bool KEXEC_FILE

1995 1996
config KEXEC_VERIFY_SIG
	bool "Verify kernel signature during kexec_file_load() syscall"
1997
	depends on KEXEC_FILE
1998 1999
	---help---
	  This option makes kernel signature verification mandatory for
2000 2001 2002 2003 2004
	  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.
2005 2006 2007 2008 2009 2010 2011 2012 2013

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.

2014
config CRASH_DUMP
2015
	bool "kernel crash dumps"
2016
	depends on X86_64 || (X86_32 && HIGHMEM)
2017
	---help---
2018 2019 2020 2021 2022 2023 2024 2025 2026 2027
	  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
2029
	bool "kexec jump"
2030
	depends on KEXEC && HIBERNATION
2031
	---help---
2032 2033
	  Jump between original kernel and kexeced kernel and invoke
	  code in physical address mode via KEXEC
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2034

2035
config PHYSICAL_START
2036
	hex "Physical address where the kernel is loaded" if (EXPERT || CRASH_DUMP)
2037
	default "0x1000000"
2038
	---help---
2039 2040 2041 2042 2043 2044 2045 2046 2047 2048 2049 2050 2051 2052 2053 2054 2055
	  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.

2056 2057 2058 2059 2060 2061 2062 2063 2064
	  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.
2065 2066 2067 2068 2069 2070 2071 2072 2073 2074 2075 2076

	  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
2077 2078
	bool "Build a relocatable kernel"
	default y
2079
	---help---
2080 2081 2082 2083 2084 2085 2086 2087 2088 2089 2090
	  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
2091
	  (CONFIG_PHYSICAL_START) is used as the minimum location.
2092

2093
config RANDOMIZE_BASE
2094
	bool "Randomize the address of the kernel image (KASLR)"
2095
	depends on RELOCATABLE
2096
	default y
2097
	---help---
2098 2099 2100 2101 2102 2103 2104
	  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.

2105 2106 2107 2108 2109 2110 2111 2112 2113 2114
	  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).
2115 2116 2117 2118

	  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
2119 2120 2121 2122 2123 2124
	  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.
2125

2126
	  If unsure, say Y.
2127 2128

# Relocation on x86 needs some additional build support
2129 2130
config X86_NEED_RELOCS
	def_bool y
2131
	depends on RANDOMIZE_BASE || (X86_32 && RELOCATABLE)
2132

2133
config PHYSICAL_ALIGN
2134
	hex "Alignment value to which kernel should be aligned"
2135
	default "0x200000"
2136 2137
	range 0x2000 0x1000000 if X86_32
	range 0x200000 0x1000000 if X86_64
2138
	---help---
2139 2140 2141 2142 2143 2144 2145 2146 2147 2148 2149 2150 2151 2152 2153 2154
	  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.

2155 2156 2157
	  On 32-bit this value must be a multiple of 0x2000. On 64-bit
	  this value must be a multiple of 0x200000.

2158 2159
	  Don't change this unless you know what you are doing.

2160 2161 2162 2163 2164 2165
config DYNAMIC_MEMORY_LAYOUT
	bool
	---help---
	  This option makes base addresses of vmalloc and vmemmap as well as
	  __PAGE_OFFSET movable during boot.

2166 2167 2168 2169
config RANDOMIZE_MEMORY
	bool "Randomize the kernel memory sections"
	depends on X86_64
	depends on RANDOMIZE_BASE
2170
	select DYNAMIC_MEMORY_LAYOUT
2171 2172 2173 2174 2175 2176 2177 2178 2179 2180 2181
	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.

2182
	   If unsure, say Y.
2183

2184 2185 2186 2187 2188 2189 2190 2191 2192 2193 2194 2195 2196 2197 2198
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.

2199
config HOTPLUG_CPU
2200
	bool "Support for hot-pluggable CPUs"
2201
	depends on SMP
2202
	---help---
2203 2204 2205 2206 2207
	  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.
2208

2209 2210 2211
config BOOTPARAM_HOTPLUG_CPU0
	bool "Set default setting of cpu0_hotpluggable"
	default n
2212
	depends on HOTPLUG_CPU
2213 2214 2215 2216 2217 2218 2219 2220 2221 2222 2223 2224 2225 2226 2227 2228 2229 2230 2231 2232 2233 2234 2235 2236 2237
	---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.

2238 2239 2240
config DEBUG_HOTPLUG_CPU0
	def_bool n
	prompt "Debug CPU0 hotplug"
2241
	depends on HOTPLUG_CPU
2242 2243 2244 2245 2246 2247 2248 2249 2250 2251 2252
	---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.

2253
config COMPAT_VDSO
2254 2255
	def_bool n
	prompt "Disable the 32-bit vDSO (needed for glibc 2.3.3)"
2256
	depends on COMPAT_32
2257
	---help---
2258 2259 2260
	  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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Randy Dunlap 已提交
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2262 2263 2264 2265 2266
	  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".
2267

2268 2269 2270 2271 2272 2273 2274 2275 2276
	  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.
2277

2278 2279 2280 2281 2282 2283 2284 2285 2286 2287 2288
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
2289
	  line parameter vsyscall=[emulate|none].
2290 2291 2292 2293 2294 2295 2296 2297 2298 2299 2300 2301 2302 2303 2304 2305 2306 2307 2308 2309 2310 2311 2312 2313 2314 2315 2316 2317

	  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_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

2318 2319
config CMDLINE_BOOL
	bool "Built-in kernel command line"
2320
	---help---
2321 2322 2323 2324 2325 2326 2327 2328
	  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
2329
	  boot arguments in CONFIG_CMDLINE.
2330 2331 2332 2333 2334 2335 2336 2337

	  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 ""
2338
	---help---
2339 2340 2341 2342 2343 2344 2345 2346 2347 2348 2349 2350 2351 2352 2353
	  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
2354
	---help---
2355 2356 2357 2358 2359 2360
	  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.

2361 2362 2363 2364 2365 2366 2367 2368 2369 2370 2371 2372 2373 2374 2375 2376
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.

2377 2378
source "kernel/livepatch/Kconfig"

2379 2380
endmenu

2381 2382 2383 2384
config ARCH_HAS_ADD_PAGES
	def_bool y
	depends on X86_64 && ARCH_ENABLE_MEMORY_HOTPLUG

2385 2386 2387 2388
config ARCH_ENABLE_MEMORY_HOTPLUG
	def_bool y
	depends on X86_64 || (X86_32 && HIGHMEM)

2389 2390 2391 2392
config ARCH_ENABLE_MEMORY_HOTREMOVE
	def_bool y
	depends on MEMORY_HOTPLUG

2393
config USE_PERCPU_NUMA_NODE_ID
2394
	def_bool y
2395 2396
	depends on NUMA

2397 2398 2399 2400
config ARCH_ENABLE_SPLIT_PMD_PTLOCK
	def_bool y
	depends on X86_64 || X86_PAE

2401 2402 2403 2404
config ARCH_ENABLE_HUGEPAGE_MIGRATION
	def_bool y
	depends on X86_64 && HUGETLB_PAGE && MIGRATION

2405 2406 2407 2408
config ARCH_ENABLE_THP_MIGRATION
	def_bool y
	depends on X86_64 && TRANSPARENT_HUGEPAGE

2409
menu "Power management and ACPI options"
2410 2411

config ARCH_HIBERNATION_HEADER
2412
	def_bool y
2413 2414 2415 2416 2417 2418
	depends on X86_64 && HIBERNATION

source "kernel/power/Kconfig"

source "drivers/acpi/Kconfig"

2419 2420
source "drivers/sfi/Kconfig"

2421
config X86_APM_BOOT
2422
	def_bool y
2423
	depends on APM
2424

2425 2426
menuconfig APM
	tristate "APM (Advanced Power Management) BIOS support"
2427
	depends on X86_32 && PM_SLEEP
2428 2429 2430 2431 2432 2433 2434 2435 2436 2437 2438 2439 2440 2441 2442
	---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
2443 2444
	  and more information, read <file:Documentation/power/apm-acpi.txt>
	  and the Battery Powered Linux mini-HOWTO, available from
2445 2446 2447 2448 2449 2450 2451 2452 2453 2454 2455 2456 2457 2458 2459 2460 2461 2462 2463 2464 2465 2466 2467 2468 2469 2470 2471 2472 2473 2474 2475 2476 2477 2478 2479 2480 2481 2482 2483 2484 2485 2486 2487
	  <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"
2488
	---help---
2489 2490 2491 2492 2493 2494 2495 2496 2497 2498 2499 2500 2501 2502 2503 2504 2505 2506 2507 2508 2509 2510
	  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
2511
	depends on CPU_IDLE
2512
	bool "Make CPU Idle calls when idle"
2513
	---help---
2514 2515 2516 2517 2518 2519 2520 2521 2522 2523
	  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"
2524
	---help---
2525 2526 2527 2528 2529 2530 2531 2532 2533 2534 2535 2536
	  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"
2537
	---help---
2538 2539 2540 2541 2542 2543 2544 2545 2546
	  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

2547
source "drivers/cpufreq/Kconfig"
2548 2549 2550

source "drivers/cpuidle/Kconfig"

A
Andy Henroid 已提交
2551 2552
source "drivers/idle/Kconfig"

2553 2554 2555 2556 2557 2558
endmenu


menu "Bus options (PCI etc.)"

config PCI
2559
	bool "PCI support"
A
Adrian Bunk 已提交
2560
	default y
2561
	---help---
2562 2563 2564 2565 2566 2567 2568
	  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"
2569
	depends on X86_32 && PCI
2570 2571 2572 2573 2574 2575 2576 2577 2578 2579 2580 2581 2582 2583 2584 2585 2586 2587 2588 2589 2590 2591 2592 2593 2594
	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"

2595
config PCI_GOOLPC
2596
	bool "OLPC XO-1"
2597 2598
	depends on OLPC

2599 2600 2601
config PCI_GOANY
	bool "Any"

2602 2603 2604
endchoice

config PCI_BIOS
2605
	def_bool y
2606
	depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY)
2607 2608 2609

# x86-64 doesn't support PCI BIOS access from long mode so always go direct.
config PCI_DIRECT
2610
	def_bool y
2611
	depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC || PCI_GOMMCONFIG))
2612 2613

config PCI_MMCONFIG
2614 2615
	bool "Support mmconfig PCI config space access" if X86_64
	default y
2616
	depends on PCI && (ACPI || SFI || JAILHOUSE_GUEST)
2617
	depends on X86_64 || (PCI_GOANY || PCI_GOMMCONFIG)
2618

2619
config PCI_OLPC
2620 2621
	def_bool y
	depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY)
2622

2623 2624 2625 2626 2627
config PCI_XEN
	def_bool y
	depends on PCI && XEN
	select SWIOTLB_XEN

2628
config PCI_DOMAINS
2629
	def_bool y
2630 2631
	depends on PCI

2632 2633 2634
config MMCONF_FAM10H
	def_bool y
	depends on X86_64 && PCI_MMCONFIG && ACPI
2635

2636
config PCI_CNB20LE_QUIRK
2637
	bool "Read CNB20LE Host Bridge Windows" if EXPERT
2638
	depends on PCI
2639 2640 2641 2642 2643
	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.

2644 2645 2646 2647 2648
	  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.

2649 2650
source "drivers/pci/Kconfig"

2651
config ISA_BUS
2652
	bool "ISA bus support on modern systems" if EXPERT
2653
	help
2654 2655 2656 2657 2658
	  Expose ISA bus device drivers and options available for selection and
	  configuration. Enable this option if your target machine has an ISA
	  bus. ISA is an older system, displaced by PCI and newer bus
	  architectures -- if your target machine is modern, it probably does
	  not have an ISA bus.
2659 2660 2661

	  If unsure, say N.

2662
# x86_64 have no ISA slots, but can have ISA-style DMA.
2663
config ISA_DMA_API
2664 2665 2666 2667 2668
	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.
2669

2670 2671
if X86_32

2672 2673
config ISA
	bool "ISA support"
2674
	---help---
2675 2676 2677 2678 2679 2680 2681 2682 2683 2684 2685 2686 2687 2688 2689 2690 2691 2692 2693 2694 2695 2696 2697 2698 2699 2700
	  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"
2701
	---help---
2702 2703 2704 2705 2706 2707 2708 2709 2710
	  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"
2711
	depends on SCx200
2712
	default y
2713
	---help---
2714 2715 2716 2717 2718 2719
	  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.

2720 2721
config OLPC
	bool "One Laptop Per Child support"
2722
	depends on !X86_PAE
2723
	select GPIOLIB
2724
	select OF
2725
	select OF_PROMTREE
2726
	select IRQ_DOMAIN
2727
	---help---
2728 2729 2730
	  Add support for detecting the unique features of the OLPC
	  XO hardware.

2731 2732
config OLPC_XO1_PM
	bool "OLPC XO-1 Power Management"
2733
	depends on OLPC && MFD_CS5535 && PM_SLEEP
2734
	select MFD_CORE
2735
	---help---
2736
	  Add support for poweroff and suspend of the OLPC XO-1 laptop.
2737

2738 2739 2740 2741 2742 2743 2744
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.

2745 2746
config OLPC_XO1_SCI
	bool "OLPC XO-1 SCI extras"
2747
	depends on OLPC && OLPC_XO1_PM && GPIO_CS5535=y
2748
	depends on INPUT=y
2749
	select POWER_SUPPLY
2750 2751
	---help---
	  Add support for SCI-based features of the OLPC XO-1 laptop:
2752
	   - EC-driven system wakeups
2753
	   - Power button
2754
	   - Ebook switch
2755
	   - Lid switch
2756 2757
	   - AC adapter status updates
	   - Battery status updates
2758

2759 2760
config OLPC_XO15_SCI
	bool "OLPC XO-1.5 SCI extras"
2761 2762
	depends on OLPC && ACPI
	select POWER_SUPPLY
2763 2764 2765 2766 2767
	---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
2768

2769 2770 2771 2772 2773 2774 2775 2776 2777 2778 2779 2780 2781 2782
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.

2783 2784 2785 2786 2787 2788
config NET5501
	bool "Soekris Engineering net5501 System Support (LEDS, GPIO, etc)"
	select GPIOLIB
	---help---
	  This option enables system support for the Soekris Engineering net5501.

2789 2790 2791 2792 2793 2794 2795
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.

2796 2797 2798 2799 2800 2801 2802 2803 2804
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.

2805 2806
endif # X86_32

2807
config AMD_NB
2808
	def_bool y
2809
	depends on CPU_SUP_AMD && PCI
2810 2811 2812

source "drivers/pcmcia/Kconfig"

2813
config RAPIDIO
2814
	tristate "RapidIO support"
2815 2816 2817
	depends on PCI
	default n
	help
2818
	  If enabled this option will include drivers and the core
2819 2820 2821 2822
	  infrastructure code to support RapidIO interconnect devices.

source "drivers/rapidio/Kconfig"

2823 2824 2825 2826 2827 2828 2829 2830 2831 2832 2833 2834 2835 2836 2837 2838 2839 2840 2841 2842 2843 2844 2845 2846 2847 2848
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.

2849 2850 2851 2852 2853 2854 2855 2856 2857 2858
endmenu


menu "Executable file formats / Emulations"

source "fs/Kconfig.binfmt"

config IA32_EMULATION
	bool "IA32 Emulation"
	depends on X86_64
2859
	select ARCH_WANT_OLD_COMPAT_IPC
2860
	select BINFMT_ELF
R
Roland McGrath 已提交
2861
	select COMPAT_BINFMT_ELF
2862
	select COMPAT_OLD_SIGACTION
2863
	---help---
2864 2865 2866
	  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.
2867 2868

config IA32_AOUT
2869 2870 2871 2872
	tristate "IA32 a.out support"
	depends on IA32_EMULATION
	---help---
	  Support old a.out binaries in the 32bit emulation.
2873

2874
config X86_X32
2875
	bool "x32 ABI for 64-bit mode"
2876
	depends on X86_64
2877 2878 2879 2880 2881 2882 2883 2884 2885 2886
	---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.

2887 2888 2889 2890 2891 2892
config COMPAT_32
	def_bool y
	depends on IA32_EMULATION || X86_32
	select HAVE_UID16
	select OLD_SIGSUSPEND3

2893
config COMPAT
2894
	def_bool y
2895
	depends on IA32_EMULATION || X86_X32
2896

2897
if COMPAT
2898
config COMPAT_FOR_U64_ALIGNMENT
2899
	def_bool y
2900 2901

config SYSVIPC_COMPAT
2902
	def_bool y
2903 2904
	depends on SYSVIPC
endif
2905

2906 2907 2908
endmenu


2909 2910 2911 2912
config HAVE_ATOMIC_IOMAP
	def_bool y
	depends on X86_32

2913 2914
config X86_DEV_DMA_OPS
	bool
2915
	depends on X86_64 || STA2X11
2916

2917 2918
config X86_DMA_REMAP
	bool
2919
	depends on STA2X11
2920

2921 2922 2923
config HAVE_GENERIC_GUP
	def_bool y

2924 2925 2926 2927 2928 2929 2930 2931 2932 2933 2934 2935 2936 2937
source "net/Kconfig"

source "drivers/Kconfig"

source "drivers/firmware/Kconfig"

source "fs/Kconfig"

source "arch/x86/Kconfig.debug"

source "security/Kconfig"

source "crypto/Kconfig"

2938 2939
source "arch/x86/kvm/Kconfig"

2940
source "lib/Kconfig"
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