xref: /linux/arch/x86/Kconfig (revision abde587b61a3ddb2918385f95ef2b3ca37d5a017)
1b2441318SGreg Kroah-Hartman# SPDX-License-Identifier: GPL-2.0
2daa93fabSSam Ravnborg# Select 32 or 64 bit
3daa93fabSSam Ravnborgconfig 64BIT
46840999bSSam Ravnborg	bool "64-bit kernel" if ARCH = "x86"
5ffee0de4SDavid Woodhouse	default ARCH != "i386"
68f9ca475SIngo Molnar	---help---
7daa93fabSSam Ravnborg	  Say yes to build a 64-bit kernel - formerly known as x86_64
8daa93fabSSam Ravnborg	  Say no to build a 32-bit kernel - formerly known as i386
9daa93fabSSam Ravnborg
10daa93fabSSam Ravnborgconfig X86_32
113120e25eSJan Beulich	def_bool y
123120e25eSJan Beulich	depends on !64BIT
13341c787eSIngo Molnar	# Options that are inherently 32-bit kernel only:
14341c787eSIngo Molnar	select ARCH_WANT_IPC_PARSE_VERSION
15341c787eSIngo Molnar	select CLKSRC_I8253
16341c787eSIngo Molnar	select CLONE_BACKWARDS
17341c787eSIngo Molnar	select HAVE_AOUT
18341c787eSIngo Molnar	select HAVE_GENERIC_DMA_COHERENT
19341c787eSIngo Molnar	select MODULES_USE_ELF_REL
20341c787eSIngo Molnar	select OLD_SIGACTION
21daa93fabSSam Ravnborg
22daa93fabSSam Ravnborgconfig X86_64
233120e25eSJan Beulich	def_bool y
243120e25eSJan Beulich	depends on 64BIT
25d94e0685SIngo Molnar	# Options that are inherently 64-bit kernel only:
26e1073d1eSAneesh Kumar K.V	select ARCH_HAS_GIGANTIC_PAGE if (MEMORY_ISOLATION && COMPACTION) || CMA
27d94e0685SIngo Molnar	select ARCH_SUPPORTS_INT128
28d94e0685SIngo Molnar	select ARCH_USE_CMPXCHG_LOCKREF
29d94e0685SIngo Molnar	select HAVE_ARCH_SOFT_DIRTY
30d94e0685SIngo Molnar	select MODULES_USE_ELF_RELA
31d94e0685SIngo Molnar	select X86_DEV_DMA_OPS
321032c0baSSam Ravnborg
33d94e0685SIngo Molnar#
34d94e0685SIngo Molnar# Arch settings
35d94e0685SIngo Molnar#
36d94e0685SIngo Molnar# ( Note that options that are marked 'if X86_64' could in principle be
37d94e0685SIngo Molnar#   ported to 32-bit as well. )
38d94e0685SIngo Molnar#
398d5fffb9SSam Ravnborgconfig X86
403c2362e6SHarvey Harrison	def_bool y
41c763ea26SIngo Molnar	#
42c763ea26SIngo Molnar	# Note: keep this list sorted alphabetically
43c763ea26SIngo Molnar	#
446471b825SIngo Molnar	select ACPI_LEGACY_TABLES_LOOKUP	if ACPI
456e0a0ea1SGraeme Gregory	select ACPI_SYSTEM_POWER_STATES_SUPPORT	if ACPI
466471b825SIngo Molnar	select ANON_INODES
476471b825SIngo Molnar	select ARCH_CLOCKSOURCE_DATA
486471b825SIngo Molnar	select ARCH_DISCARD_MEMBLOCK
4991dda51aSAleksey Makarov	select ARCH_HAS_ACPI_TABLE_UPGRADE	if ACPI
50fa5b6ec9SLaura Abbott	select ARCH_HAS_DEBUG_VIRTUAL
5121266be9SDan Williams	select ARCH_HAS_DEVMEM_IS_ALLOWED
526471b825SIngo Molnar	select ARCH_HAS_ELF_RANDOMIZE
5372d93104SLinus Torvalds	select ARCH_HAS_FAST_MULTIPLIER
546974f0c4SDaniel Micay	select ARCH_HAS_FORTIFY_SOURCE
55957e3facSRiku Voipio	select ARCH_HAS_GCOV_PROFILE_ALL
565c9a8750SDmitry Vyukov	select ARCH_HAS_KCOV			if X86_64
57c763ea26SIngo Molnar	select ARCH_HAS_PMEM_API		if X86_64
5839208aa7SKees Cook	select ARCH_HAS_REFCOUNT
590aed55afSDan Williams	select ARCH_HAS_UACCESS_FLUSHCACHE	if X86_64
60d2852a22SDaniel Borkmann	select ARCH_HAS_SET_MEMORY
616471b825SIngo Molnar	select ARCH_HAS_SG_CHAIN
62ad21fc4fSLaura Abbott	select ARCH_HAS_STRICT_KERNEL_RWX
63ad21fc4fSLaura Abbott	select ARCH_HAS_STRICT_MODULE_RWX
64c6d30853SAndrey Ryabinin	select ARCH_HAS_UBSAN_SANITIZE_ALL
6565f7d049SOliver O'Halloran	select ARCH_HAS_ZONE_DEVICE		if X86_64
666471b825SIngo Molnar	select ARCH_HAVE_NMI_SAFE_CMPXCHG
676471b825SIngo Molnar	select ARCH_MIGHT_HAVE_ACPI_PDC		if ACPI
6877fbbc81SMark Salter	select ARCH_MIGHT_HAVE_PC_PARPORT
695e2c18c0SMark Salter	select ARCH_MIGHT_HAVE_PC_SERIO
706471b825SIngo Molnar	select ARCH_SUPPORTS_ATOMIC_RMW
713b242c66SMel Gorman	select ARCH_SUPPORTS_DEFERRED_STRUCT_PAGE_INIT
726471b825SIngo Molnar	select ARCH_SUPPORTS_NUMA_BALANCING	if X86_64
736471b825SIngo Molnar	select ARCH_USE_BUILTIN_BSWAP
746471b825SIngo Molnar	select ARCH_USE_QUEUED_RWLOCKS
756471b825SIngo Molnar	select ARCH_USE_QUEUED_SPINLOCKS
76ce4a4e56SAndy Lutomirski	select ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH
77c763ea26SIngo Molnar	select ARCH_WANTS_DYNAMIC_TASK_STRUCT
7838d8b4e6SHuang Ying	select ARCH_WANTS_THP_SWAP		if X86_64
796471b825SIngo Molnar	select BUILDTIME_EXTABLE_SORT
806471b825SIngo Molnar	select CLKEVT_I8253
816471b825SIngo Molnar	select CLOCKSOURCE_VALIDATE_LAST_CYCLE
826471b825SIngo Molnar	select CLOCKSOURCE_WATCHDOG
836471b825SIngo Molnar	select DCACHE_WORD_ACCESS
8445471cd9SLinus Torvalds	select EDAC_ATOMIC_SCRUB
8545471cd9SLinus Torvalds	select EDAC_SUPPORT
866471b825SIngo Molnar	select GENERIC_CLOCKEVENTS
876471b825SIngo Molnar	select GENERIC_CLOCKEVENTS_BROADCAST	if X86_64 || (X86_32 && X86_LOCAL_APIC)
886471b825SIngo Molnar	select GENERIC_CLOCKEVENTS_MIN_ADJUST
896471b825SIngo Molnar	select GENERIC_CMOS_UPDATE
906471b825SIngo Molnar	select GENERIC_CPU_AUTOPROBE
916471b825SIngo Molnar	select GENERIC_EARLY_IOREMAP
926471b825SIngo Molnar	select GENERIC_FIND_FIRST_BIT
936471b825SIngo Molnar	select GENERIC_IOMAP
94c7d6c9ddSThomas Gleixner	select GENERIC_IRQ_EFFECTIVE_AFF_MASK	if SMP
950fa115daSThomas Gleixner	select GENERIC_IRQ_MATRIX_ALLOCATOR	if X86_LOCAL_APIC
96ad7a929fSThomas Gleixner	select GENERIC_IRQ_MIGRATION		if SMP
976471b825SIngo Molnar	select GENERIC_IRQ_PROBE
98c201c917SThomas Gleixner	select GENERIC_IRQ_RESERVATION_MODE
996471b825SIngo Molnar	select GENERIC_IRQ_SHOW
1006471b825SIngo Molnar	select GENERIC_PENDING_IRQ		if SMP
1016471b825SIngo Molnar	select GENERIC_SMP_IDLE_THREAD
1026471b825SIngo Molnar	select GENERIC_STRNCPY_FROM_USER
1036471b825SIngo Molnar	select GENERIC_STRNLEN_USER
1046471b825SIngo Molnar	select GENERIC_TIME_VSYSCALL
1057edaeb68SThomas Gleixner	select HARDLOCKUP_CHECK_TIMESTAMP	if X86_64
1066471b825SIngo Molnar	select HAVE_ACPI_APEI			if ACPI
1076471b825SIngo Molnar	select HAVE_ACPI_APEI_NMI		if ACPI
1086471b825SIngo Molnar	select HAVE_ALIGNED_STRUCT_PAGE		if SLUB
1096471b825SIngo Molnar	select HAVE_ARCH_AUDITSYSCALL
1106471b825SIngo Molnar	select HAVE_ARCH_HUGE_VMAP		if X86_64 || X86_PAE
1116471b825SIngo Molnar	select HAVE_ARCH_JUMP_LABEL
112d17a1d97SAndrey Ryabinin	select HAVE_ARCH_KASAN			if X86_64
1136471b825SIngo Molnar	select HAVE_ARCH_KGDB
1149e08f57dSDaniel Cashman	select HAVE_ARCH_MMAP_RND_BITS		if MMU
1159e08f57dSDaniel Cashman	select HAVE_ARCH_MMAP_RND_COMPAT_BITS	if MMU && COMPAT
1161b028f78SDmitry Safonov	select HAVE_ARCH_COMPAT_MMAP_BASES	if MMU && COMPAT
1176471b825SIngo Molnar	select HAVE_ARCH_SECCOMP_FILTER
1186471b825SIngo Molnar	select HAVE_ARCH_TRACEHOOK
1196471b825SIngo Molnar	select HAVE_ARCH_TRANSPARENT_HUGEPAGE
120a00cc7d9SMatthew Wilcox	select HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD if X86_64
121e37e43a4SAndy Lutomirski	select HAVE_ARCH_VMAP_STACK		if X86_64
122c763ea26SIngo Molnar	select HAVE_ARCH_WITHIN_STACK_FRAMES
1236471b825SIngo Molnar	select HAVE_CC_STACKPROTECTOR
1246471b825SIngo Molnar	select HAVE_CMPXCHG_DOUBLE
1256471b825SIngo Molnar	select HAVE_CMPXCHG_LOCAL
1266471b825SIngo Molnar	select HAVE_CONTEXT_TRACKING		if X86_64
127c1bd55f9SJosh Triplett	select HAVE_COPY_THREAD_TLS
1286471b825SIngo Molnar	select HAVE_C_RECORDMCOUNT
1296471b825SIngo Molnar	select HAVE_DEBUG_KMEMLEAK
1306471b825SIngo Molnar	select HAVE_DEBUG_STACKOVERFLOW
1316471b825SIngo Molnar	select HAVE_DMA_API_DEBUG
1329c5a3621SAkinobu Mita	select HAVE_DMA_CONTIGUOUS
133677aa9f7SSteven Rostedt	select HAVE_DYNAMIC_FTRACE
13406aeaaeaSMasami Hiramatsu	select HAVE_DYNAMIC_FTRACE_WITH_REGS
135c763ea26SIngo Molnar	select HAVE_EBPF_JIT			if X86_64
13658340a07SJohannes Berg	select HAVE_EFFICIENT_UNALIGNED_ACCESS
1375f56a5dfSJiri Slaby	select HAVE_EXIT_THREAD
138644e0e8dSSteven Rostedt (VMware)	select HAVE_FENTRY			if X86_64 || DYNAMIC_FTRACE
1396471b825SIngo Molnar	select HAVE_FTRACE_MCOUNT_RECORD
1406471b825SIngo Molnar	select HAVE_FUNCTION_GRAPH_TRACER
1416471b825SIngo Molnar	select HAVE_FUNCTION_TRACER
1426b90bd4bSEmese Revfy	select HAVE_GCC_PLUGINS
1430067f129SK.Prasad	select HAVE_HW_BREAKPOINT
1446471b825SIngo Molnar	select HAVE_IDE
1456471b825SIngo Molnar	select HAVE_IOREMAP_PROT
1466471b825SIngo Molnar	select HAVE_IRQ_EXIT_ON_IRQ_STACK	if X86_64
1476471b825SIngo Molnar	select HAVE_IRQ_TIME_ACCOUNTING
1486471b825SIngo Molnar	select HAVE_KERNEL_BZIP2
1496471b825SIngo Molnar	select HAVE_KERNEL_GZIP
1506471b825SIngo Molnar	select HAVE_KERNEL_LZ4
1516471b825SIngo Molnar	select HAVE_KERNEL_LZMA
1526471b825SIngo Molnar	select HAVE_KERNEL_LZO
1536471b825SIngo Molnar	select HAVE_KERNEL_XZ
1546471b825SIngo Molnar	select HAVE_KPROBES
1556471b825SIngo Molnar	select HAVE_KPROBES_ON_FTRACE
1566471b825SIngo Molnar	select HAVE_KRETPROBES
1576471b825SIngo Molnar	select HAVE_KVM
1586471b825SIngo Molnar	select HAVE_LIVEPATCH			if X86_64
1596471b825SIngo Molnar	select HAVE_MEMBLOCK
1606471b825SIngo Molnar	select HAVE_MEMBLOCK_NODE_MAP
1610102752eSFrederic Weisbecker	select HAVE_MIXED_BREAKPOINTS_REGS
162ee9f8fceSJosh Poimboeuf	select HAVE_MOD_ARCH_SPECIFIC
16342a0bb3fSPetr Mladek	select HAVE_NMI
1646471b825SIngo Molnar	select HAVE_OPROFILE
1656471b825SIngo Molnar	select HAVE_OPTPROBES
1666471b825SIngo Molnar	select HAVE_PCSPKR_PLATFORM
1676471b825SIngo Molnar	select HAVE_PERF_EVENTS
168c01d4323SFrederic Weisbecker	select HAVE_PERF_EVENTS_NMI
16992e5aae4SNicholas Piggin	select HAVE_HARDLOCKUP_DETECTOR_PERF	if PERF_EVENTS && HAVE_PERF_EVENTS_NMI
170c5e63197SJiri Olsa	select HAVE_PERF_REGS
171c5ebcedbSJiri Olsa	select HAVE_PERF_USER_STACK_DUMP
1729e52fc2bSVitaly Kuznetsov	select HAVE_RCU_TABLE_FREE
1736471b825SIngo Molnar	select HAVE_REGS_AND_STACK_ACCESS_API
17411af8474SJosh Poimboeuf	select HAVE_RELIABLE_STACKTRACE		if X86_64 && UNWINDER_FRAME_POINTER && STACK_VALIDATION
175c763ea26SIngo Molnar	select HAVE_STACK_VALIDATION		if X86_64
1766471b825SIngo Molnar	select HAVE_SYSCALL_TRACEPOINTS
1776471b825SIngo Molnar	select HAVE_UNSTABLE_SCHED_CLOCK
1787c68af6eSAvi Kivity	select HAVE_USER_RETURN_NOTIFIER
179c0185808SThomas Gleixner	select IRQ_FORCED_THREADING
180df65c1bcSThomas Gleixner	select PCI_LOCKLESS_CONFIG
1816471b825SIngo Molnar	select PERF_EVENTS
1823195ef59SPrarit Bhargava	select RTC_LIB
183d6faca40SArnd Bergmann	select RTC_MC146818_LIB
1846471b825SIngo Molnar	select SPARSE_IRQ
18583fe27eaSPranith Kumar	select SRCU
1866471b825SIngo Molnar	select SYSCTL_EXCEPTION_TRACE
18715f4eae7SAndy Lutomirski	select THREAD_INFO_IN_TASK
1886471b825SIngo Molnar	select USER_STACKTRACE_SUPPORT
1896471b825SIngo Molnar	select VIRT_TO_BUS
1906471b825SIngo Molnar	select X86_FEATURE_NAMES		if PROC_FS
1917d8330a5SBalbir Singh
192ba7e4d13SIngo Molnarconfig INSTRUCTION_DECODER
1933120e25eSJan Beulich	def_bool y
1943120e25eSJan Beulich	depends on KPROBES || PERF_EVENTS || UPROBES
195ba7e4d13SIngo Molnar
19651b26adaSLinus Torvaldsconfig OUTPUT_FORMAT
19751b26adaSLinus Torvalds	string
19851b26adaSLinus Torvalds	default "elf32-i386" if X86_32
19951b26adaSLinus Torvalds	default "elf64-x86-64" if X86_64
20051b26adaSLinus Torvalds
20173531905SSam Ravnborgconfig ARCH_DEFCONFIG
202b9b39bfbSSam Ravnborg	string
20373531905SSam Ravnborg	default "arch/x86/configs/i386_defconfig" if X86_32
20473531905SSam Ravnborg	default "arch/x86/configs/x86_64_defconfig" if X86_64
205b9b39bfbSSam Ravnborg
2068d5fffb9SSam Ravnborgconfig LOCKDEP_SUPPORT
2073c2362e6SHarvey Harrison	def_bool y
2088d5fffb9SSam Ravnborg
2098d5fffb9SSam Ravnborgconfig STACKTRACE_SUPPORT
2103c2362e6SHarvey Harrison	def_bool y
2118d5fffb9SSam Ravnborg
2128d5fffb9SSam Ravnborgconfig MMU
2133c2362e6SHarvey Harrison	def_bool y
2148d5fffb9SSam Ravnborg
2159e08f57dSDaniel Cashmanconfig ARCH_MMAP_RND_BITS_MIN
2169e08f57dSDaniel Cashman	default 28 if 64BIT
2179e08f57dSDaniel Cashman	default 8
2189e08f57dSDaniel Cashman
2199e08f57dSDaniel Cashmanconfig ARCH_MMAP_RND_BITS_MAX
2209e08f57dSDaniel Cashman	default 32 if 64BIT
2219e08f57dSDaniel Cashman	default 16
2229e08f57dSDaniel Cashman
2239e08f57dSDaniel Cashmanconfig ARCH_MMAP_RND_COMPAT_BITS_MIN
2249e08f57dSDaniel Cashman	default 8
2259e08f57dSDaniel Cashman
2269e08f57dSDaniel Cashmanconfig ARCH_MMAP_RND_COMPAT_BITS_MAX
2279e08f57dSDaniel Cashman	default 16
2289e08f57dSDaniel Cashman
2298d5fffb9SSam Ravnborgconfig SBUS
2308d5fffb9SSam Ravnborg	bool
2318d5fffb9SSam Ravnborg
2323bc4e459SFUJITA Tomonoriconfig NEED_DMA_MAP_STATE
2333120e25eSJan Beulich	def_bool y
234a6dfa128SKonrad Rzeszutek Wilk	depends on X86_64 || INTEL_IOMMU || DMA_API_DEBUG || SWIOTLB
2353bc4e459SFUJITA Tomonori
23618e98307SFUJITA Tomonoriconfig NEED_SG_DMA_LENGTH
2374a14d84eSAndrew Morton	def_bool y
23818e98307SFUJITA Tomonori
2398d5fffb9SSam Ravnborgconfig GENERIC_ISA_DMA
2403120e25eSJan Beulich	def_bool y
2413120e25eSJan Beulich	depends on ISA_DMA_API
2428d5fffb9SSam Ravnborg
2438d5fffb9SSam Ravnborgconfig GENERIC_BUG
2443c2362e6SHarvey Harrison	def_bool y
2458d5fffb9SSam Ravnborg	depends on BUG
246b93a531eSJan Beulich	select GENERIC_BUG_RELATIVE_POINTERS if X86_64
247b93a531eSJan Beulich
248b93a531eSJan Beulichconfig GENERIC_BUG_RELATIVE_POINTERS
249b93a531eSJan Beulich	bool
2508d5fffb9SSam Ravnborg
2518d5fffb9SSam Ravnborgconfig GENERIC_HWEIGHT
2523c2362e6SHarvey Harrison	def_bool y
2538d5fffb9SSam Ravnborg
2548d5fffb9SSam Ravnborgconfig ARCH_MAY_HAVE_PC_FDC
2553120e25eSJan Beulich	def_bool y
2563120e25eSJan Beulich	depends on ISA_DMA_API
2578d5fffb9SSam Ravnborg
2581032c0baSSam Ravnborgconfig RWSEM_XCHGADD_ALGORITHM
2593120e25eSJan Beulich	def_bool y
2601032c0baSSam Ravnborg
2611032c0baSSam Ravnborgconfig GENERIC_CALIBRATE_DELAY
2621032c0baSSam Ravnborg	def_bool y
2631032c0baSSam Ravnborg
2649a0b8415Svenkatesh.pallipadi@intel.comconfig ARCH_HAS_CPU_RELAX
2659a0b8415Svenkatesh.pallipadi@intel.com	def_bool y
2668d5fffb9SSam Ravnborg
2671b27d05bSPekka Enbergconfig ARCH_HAS_CACHE_LINE_SIZE
2681b27d05bSPekka Enberg	def_bool y
2691b27d05bSPekka Enberg
270dd5af90aSMike Travisconfig HAVE_SETUP_PER_CPU_AREA
27189c9c4c5SBrian Gerst	def_bool y
272b32ef636Stravis@sgi.com
27308fc4580STejun Heoconfig NEED_PER_CPU_EMBED_FIRST_CHUNK
27408fc4580STejun Heo	def_bool y
27508fc4580STejun Heo
27608fc4580STejun Heoconfig NEED_PER_CPU_PAGE_FIRST_CHUNK
27711124411STejun Heo	def_bool y
27811124411STejun Heo
279801e4062SJohannes Bergconfig ARCH_HIBERNATION_POSSIBLE
280801e4062SJohannes Berg	def_bool y
281801e4062SJohannes Berg
282f4cb5700SJohannes Bergconfig ARCH_SUSPEND_POSSIBLE
283f4cb5700SJohannes Berg	def_bool y
284f4cb5700SJohannes Berg
285cfe28c5dSSteve Capperconfig ARCH_WANT_HUGE_PMD_SHARE
286cfe28c5dSSteve Capper	def_bool y
287cfe28c5dSSteve Capper
28853313b2cSSteve Capperconfig ARCH_WANT_GENERAL_HUGETLB
28953313b2cSSteve Capper	def_bool y
29053313b2cSSteve Capper
2918d5fffb9SSam Ravnborgconfig ZONE_DMA32
292e0fd24a3SJan Beulich	def_bool y if X86_64
2938d5fffb9SSam Ravnborg
2948d5fffb9SSam Ravnborgconfig AUDIT_ARCH
295e0fd24a3SJan Beulich	def_bool y if X86_64
2968d5fffb9SSam Ravnborg
297765c68bdSIngo Molnarconfig ARCH_SUPPORTS_OPTIMIZED_INLINING
298765c68bdSIngo Molnar	def_bool y
299765c68bdSIngo Molnar
3006a11f75bSAkinobu Mitaconfig ARCH_SUPPORTS_DEBUG_PAGEALLOC
3016a11f75bSAkinobu Mita	def_bool y
3026a11f75bSAkinobu Mita
303d6f2d75aSAndrey Ryabininconfig KASAN_SHADOW_OFFSET
304d6f2d75aSAndrey Ryabinin	hex
305d6f2d75aSAndrey Ryabinin	depends on KASAN
306d6f2d75aSAndrey Ryabinin	default 0xdffffc0000000000
307d6f2d75aSAndrey Ryabinin
30869575d38SShane Wangconfig HAVE_INTEL_TXT
30969575d38SShane Wang	def_bool y
3106ea30386SKees Cook	depends on INTEL_IOMMU && ACPI
31169575d38SShane Wang
3126b0c3d44SSam Ravnborgconfig X86_32_SMP
3136b0c3d44SSam Ravnborg	def_bool y
3146b0c3d44SSam Ravnborg	depends on X86_32 && SMP
3156b0c3d44SSam Ravnborg
3166b0c3d44SSam Ravnborgconfig X86_64_SMP
3176b0c3d44SSam Ravnborg	def_bool y
3186b0c3d44SSam Ravnborg	depends on X86_64 && SMP
3196b0c3d44SSam Ravnborg
320ccbeed3aSTejun Heoconfig X86_32_LAZY_GS
321ccbeed3aSTejun Heo	def_bool y
32260a5317fSTejun Heo	depends on X86_32 && !CC_STACKPROTECTOR
323ccbeed3aSTejun Heo
3242b144498SSrikar Dronamrajuconfig ARCH_SUPPORTS_UPROBES
3252b144498SSrikar Dronamraju	def_bool y
3262b144498SSrikar Dronamraju
327d20642f0SRob Herringconfig FIX_EARLYCON_MEM
328d20642f0SRob Herring	def_bool y
329d20642f0SRob Herring
33098233368SKirill A. Shutemovconfig PGTABLE_LEVELS
33198233368SKirill A. Shutemov	int
33277ef56e4SKirill A. Shutemov	default 5 if X86_5LEVEL
33398233368SKirill A. Shutemov	default 4 if X86_64
33498233368SKirill A. Shutemov	default 3 if X86_PAE
33598233368SKirill A. Shutemov	default 2
33698233368SKirill A. Shutemov
337506f1d07SSam Ravnborgsource "init/Kconfig"
338dc52ddc0SMatt Helsleysource "kernel/Kconfig.freezer"
3398d5fffb9SSam Ravnborg
340506f1d07SSam Ravnborgmenu "Processor type and features"
341506f1d07SSam Ravnborg
3425ee71535SRandy Dunlapconfig ZONE_DMA
3435ee71535SRandy Dunlap	bool "DMA memory allocation support" if EXPERT
3445ee71535SRandy Dunlap	default y
3455ee71535SRandy Dunlap	help
3465ee71535SRandy Dunlap	  DMA memory allocation support allows devices with less than 32-bit
3475ee71535SRandy Dunlap	  addressing to allocate within the first 16MB of address space.
3485ee71535SRandy Dunlap	  Disable if no such devices will be used.
3495ee71535SRandy Dunlap
3505ee71535SRandy Dunlap	  If unsure, say Y.
3515ee71535SRandy Dunlap
352506f1d07SSam Ravnborgconfig SMP
353506f1d07SSam Ravnborg	bool "Symmetric multi-processing support"
354506f1d07SSam Ravnborg	---help---
355506f1d07SSam Ravnborg	  This enables support for systems with more than one CPU. If you have
3564a474157SRobert Graffham	  a system with only one CPU, say N. If you have a system with more
3574a474157SRobert Graffham	  than one CPU, say Y.
358506f1d07SSam Ravnborg
3594a474157SRobert Graffham	  If you say N here, the kernel will run on uni- and multiprocessor
360506f1d07SSam Ravnborg	  machines, but will use only one CPU of a multiprocessor machine. If
361506f1d07SSam Ravnborg	  you say Y here, the kernel will run on many, but not all,
3624a474157SRobert Graffham	  uniprocessor machines. On a uniprocessor machine, the kernel
363506f1d07SSam Ravnborg	  will run faster if you say N here.
364506f1d07SSam Ravnborg
365506f1d07SSam Ravnborg	  Note that if you say Y here and choose architecture "586" or
366506f1d07SSam Ravnborg	  "Pentium" under "Processor family", the kernel will not work on 486
367506f1d07SSam Ravnborg	  architectures. Similarly, multiprocessor kernels for the "PPro"
368506f1d07SSam Ravnborg	  architecture may not work on all Pentium based boards.
369506f1d07SSam Ravnborg
370506f1d07SSam Ravnborg	  People using multiprocessor machines who say Y here should also say
371506f1d07SSam Ravnborg	  Y to "Enhanced Real Time Clock Support", below. The "Advanced Power
372506f1d07SSam Ravnborg	  Management" code will be disabled if you say Y here.
373506f1d07SSam Ravnborg
374395cf969SPaul Bolle	  See also <file:Documentation/x86/i386/IO-APIC.txt>,
375c9525a3fSBenjamin Peterson	  <file:Documentation/lockup-watchdogs.txt> and the SMP-HOWTO available at
376506f1d07SSam Ravnborg	  <http://www.tldp.org/docs.html#howto>.
377506f1d07SSam Ravnborg
378506f1d07SSam Ravnborg	  If you don't know what to do here, say N.
379506f1d07SSam Ravnborg
3809def39beSJosh Triplettconfig X86_FEATURE_NAMES
3819def39beSJosh Triplett	bool "Processor feature human-readable names" if EMBEDDED
3829def39beSJosh Triplett	default y
3839def39beSJosh Triplett	---help---
3849def39beSJosh Triplett	  This option compiles in a table of x86 feature bits and corresponding
3859def39beSJosh Triplett	  names.  This is required to support /proc/cpuinfo and a few kernel
3869def39beSJosh Triplett	  messages.  You can disable this to save space, at the expense of
3879def39beSJosh Triplett	  making those few kernel messages show numeric feature bits instead.
3889def39beSJosh Triplett
3899def39beSJosh Triplett	  If in doubt, say Y.
3909def39beSJosh Triplett
3916e1315feSBorislav Petkovconfig X86_FAST_FEATURE_TESTS
3926e1315feSBorislav Petkov	bool "Fast CPU feature tests" if EMBEDDED
3936e1315feSBorislav Petkov	default y
3946e1315feSBorislav Petkov	---help---
3956e1315feSBorislav Petkov	  Some fast-paths in the kernel depend on the capabilities of the CPU.
3966e1315feSBorislav Petkov	  Say Y here for the kernel to patch in the appropriate code at runtime
3976e1315feSBorislav Petkov	  based on the capabilities of the CPU. The infrastructure for patching
3986e1315feSBorislav Petkov	  code at runtime takes up some additional space; space-constrained
3996e1315feSBorislav Petkov	  embedded systems may wish to say N here to produce smaller, slightly
4006e1315feSBorislav Petkov	  slower code.
4016e1315feSBorislav Petkov
40206cd9a7dSYinghai Luconfig X86_X2APIC
40306cd9a7dSYinghai Lu	bool "Support x2apic"
40419e3d60dSJan Kiszka	depends on X86_LOCAL_APIC && X86_64 && (IRQ_REMAP || HYPERVISOR_GUEST)
40506cd9a7dSYinghai Lu	---help---
40606cd9a7dSYinghai Lu	  This enables x2apic support on CPUs that have this feature.
40706cd9a7dSYinghai Lu
40806cd9a7dSYinghai Lu	  This allows 32-bit apic IDs (so it can support very large systems),
40906cd9a7dSYinghai Lu	  and accesses the local apic via MSRs not via mmio.
41006cd9a7dSYinghai Lu
41106cd9a7dSYinghai Lu	  If you don't know what to do here, say N.
41206cd9a7dSYinghai Lu
4136695c85bSYinghai Luconfig X86_MPPARSE
4146e87f9b7SBin Gao	bool "Enable MPS table" if ACPI || SFI
4157a527688SJan Beulich	default y
4165ab74722SIngo Molnar	depends on X86_LOCAL_APIC
4178f9ca475SIngo Molnar	---help---
4186695c85bSYinghai Lu	  For old smp systems that do not have proper acpi support. Newer systems
4196695c85bSYinghai Lu	  (esp with 64bit cpus) with acpi support, MADT and DSDT will override it
4206695c85bSYinghai Lu
42126f7ef14SYinghai Luconfig X86_BIGSMP
42226f7ef14SYinghai Lu	bool "Support for big SMP systems with more than 8 CPUs"
42326f7ef14SYinghai Lu	depends on X86_32 && SMP
4248f9ca475SIngo Molnar	---help---
42526f7ef14SYinghai Lu	  This option is needed for the systems that have more than 8 CPUs
426506f1d07SSam Ravnborg
427ddd70cf9SJun Nakajimaconfig GOLDFISH
428ddd70cf9SJun Nakajima       def_bool y
429ddd70cf9SJun Nakajima       depends on X86_GOLDFISH
430ddd70cf9SJun Nakajima
431f01d7d51SVikas Shivappaconfig INTEL_RDT
432f01d7d51SVikas Shivappa	bool "Intel Resource Director Technology support"
43378e99b4aSFenghua Yu	default n
43478e99b4aSFenghua Yu	depends on X86 && CPU_SUP_INTEL
43559fe5a77SThomas Gleixner	select KERNFS
43678e99b4aSFenghua Yu	help
437f01d7d51SVikas Shivappa	  Select to enable resource allocation and monitoring which are
438f01d7d51SVikas Shivappa	  sub-features of Intel Resource Director Technology(RDT). More
439f01d7d51SVikas Shivappa	  information about RDT can be found in the Intel x86
440f01d7d51SVikas Shivappa	  Architecture Software Developer Manual.
44178e99b4aSFenghua Yu
44278e99b4aSFenghua Yu	  Say N if unsure.
44378e99b4aSFenghua Yu
4448425091fSRavikiran G Thirumalaiif X86_32
445c5c606d9SRavikiran G Thirumalaiconfig X86_EXTENDED_PLATFORM
446c5c606d9SRavikiran G Thirumalai	bool "Support for extended (non-PC) x86 platforms"
447c5c606d9SRavikiran G Thirumalai	default y
4488f9ca475SIngo Molnar	---help---
44906ac8346SIngo Molnar	  If you disable this option then the kernel will only support
45006ac8346SIngo Molnar	  standard PC platforms. (which covers the vast majority of
45106ac8346SIngo Molnar	  systems out there.)
45206ac8346SIngo Molnar
4538425091fSRavikiran G Thirumalai	  If you enable this option then you'll be able to select support
4548425091fSRavikiran G Thirumalai	  for the following (non-PC) 32 bit x86 platforms:
455cb7b8023SBen Hutchings		Goldfish (Android emulator)
4568425091fSRavikiran G Thirumalai		AMD Elan
4578425091fSRavikiran G Thirumalai		RDC R-321x SoC
4588425091fSRavikiran G Thirumalai		SGI 320/540 (Visual Workstation)
45983125a3aSAlessandro Rubini		STA2X11-based (e.g. Northville)
4603f4110a4SThomas Gleixner		Moorestown MID devices
46106ac8346SIngo Molnar
46206ac8346SIngo Molnar	  If you have one of these systems, or if you want to build a
46306ac8346SIngo Molnar	  generic distribution kernel, say Y here - otherwise say N.
4648425091fSRavikiran G Thirumalaiendif
46506ac8346SIngo Molnar
4668425091fSRavikiran G Thirumalaiif X86_64
4678425091fSRavikiran G Thirumalaiconfig X86_EXTENDED_PLATFORM
4688425091fSRavikiran G Thirumalai	bool "Support for extended (non-PC) x86 platforms"
4698425091fSRavikiran G Thirumalai	default y
4708425091fSRavikiran G Thirumalai	---help---
4718425091fSRavikiran G Thirumalai	  If you disable this option then the kernel will only support
4728425091fSRavikiran G Thirumalai	  standard PC platforms. (which covers the vast majority of
4738425091fSRavikiran G Thirumalai	  systems out there.)
4748425091fSRavikiran G Thirumalai
4758425091fSRavikiran G Thirumalai	  If you enable this option then you'll be able to select support
4768425091fSRavikiran G Thirumalai	  for the following (non-PC) 64 bit x86 platforms:
47744b111b5SSteffen Persvold		Numascale NumaChip
4788425091fSRavikiran G Thirumalai		ScaleMP vSMP
4798425091fSRavikiran G Thirumalai		SGI Ultraviolet
4808425091fSRavikiran G Thirumalai
4818425091fSRavikiran G Thirumalai	  If you have one of these systems, or if you want to build a
4828425091fSRavikiran G Thirumalai	  generic distribution kernel, say Y here - otherwise say N.
4838425091fSRavikiran G Thirumalaiendif
484c5c606d9SRavikiran G Thirumalai# This is an alphabetically sorted list of 64 bit extended platforms
485c5c606d9SRavikiran G Thirumalai# Please maintain the alphabetic order if and when there are additions
48644b111b5SSteffen Persvoldconfig X86_NUMACHIP
48744b111b5SSteffen Persvold	bool "Numascale NumaChip"
48844b111b5SSteffen Persvold	depends on X86_64
48944b111b5SSteffen Persvold	depends on X86_EXTENDED_PLATFORM
49044b111b5SSteffen Persvold	depends on NUMA
49144b111b5SSteffen Persvold	depends on SMP
49244b111b5SSteffen Persvold	depends on X86_X2APIC
493f9726bfdSDaniel J Blueman	depends on PCI_MMCONFIG
49444b111b5SSteffen Persvold	---help---
49544b111b5SSteffen Persvold	  Adds support for Numascale NumaChip large-SMP systems. Needed to
49644b111b5SSteffen Persvold	  enable more than ~168 cores.
49744b111b5SSteffen Persvold	  If you don't have one of these, you should say N here.
49803b48632SNick Piggin
4996a48565eSIngo Molnarconfig X86_VSMP
500c5c606d9SRavikiran G Thirumalai	bool "ScaleMP vSMP"
5016276a074SBorislav Petkov	select HYPERVISOR_GUEST
5026a48565eSIngo Molnar	select PARAVIRT
5036a48565eSIngo Molnar	depends on X86_64 && PCI
504c5c606d9SRavikiran G Thirumalai	depends on X86_EXTENDED_PLATFORM
505ead91d4bSShai Fultheim	depends on SMP
5068f9ca475SIngo Molnar	---help---
5076a48565eSIngo Molnar	  Support for ScaleMP vSMP systems.  Say 'Y' here if this kernel is
5086a48565eSIngo Molnar	  supposed to run on these EM64T-based machines.  Only choose this option
5096a48565eSIngo Molnar	  if you have one of these machines.
5106a48565eSIngo Molnar
511c5c606d9SRavikiran G Thirumalaiconfig X86_UV
512c5c606d9SRavikiran G Thirumalai	bool "SGI Ultraviolet"
513c5c606d9SRavikiran G Thirumalai	depends on X86_64
514c5c606d9SRavikiran G Thirumalai	depends on X86_EXTENDED_PLATFORM
51554c28d29SJack Steiner	depends on NUMA
5161ecb4ae5SAndrew Morton	depends on EFI
5179d6c26e7SSuresh Siddha	depends on X86_X2APIC
5181222e564SIngo Molnar	depends on PCI
519c5c606d9SRavikiran G Thirumalai	---help---
520c5c606d9SRavikiran G Thirumalai	  This option is needed in order to support SGI Ultraviolet systems.
521c5c606d9SRavikiran G Thirumalai	  If you don't have one of these, you should say N here.
522c5c606d9SRavikiran G Thirumalai
523c5c606d9SRavikiran G Thirumalai# Following is an alphabetically sorted list of 32 bit extended platforms
524c5c606d9SRavikiran G Thirumalai# Please maintain the alphabetic order if and when there are additions
525506f1d07SSam Ravnborg
526ddd70cf9SJun Nakajimaconfig X86_GOLDFISH
527ddd70cf9SJun Nakajima       bool "Goldfish (Virtual Platform)"
528cb7b8023SBen Hutchings       depends on X86_EXTENDED_PLATFORM
529ddd70cf9SJun Nakajima       ---help---
530ddd70cf9SJun Nakajima	 Enable support for the Goldfish virtual platform used primarily
531ddd70cf9SJun Nakajima	 for Android development. Unless you are building for the Android
532ddd70cf9SJun Nakajima	 Goldfish emulator say N here.
533ddd70cf9SJun Nakajima
534c751e17bSThomas Gleixnerconfig X86_INTEL_CE
535c751e17bSThomas Gleixner	bool "CE4100 TV platform"
536c751e17bSThomas Gleixner	depends on PCI
537c751e17bSThomas Gleixner	depends on PCI_GODIRECT
5386084a6e2SJiang Liu	depends on X86_IO_APIC
539c751e17bSThomas Gleixner	depends on X86_32
540c751e17bSThomas Gleixner	depends on X86_EXTENDED_PLATFORM
54137bc9f50SDirk Brandewie	select X86_REBOOTFIXUPS
542da6b737bSSebastian Andrzej Siewior	select OF
543da6b737bSSebastian Andrzej Siewior	select OF_EARLY_FLATTREE
544c751e17bSThomas Gleixner	---help---
545c751e17bSThomas Gleixner	  Select for the Intel CE media processor (CE4100) SOC.
546c751e17bSThomas Gleixner	  This option compiles in support for the CE4100 SOC for settop
547c751e17bSThomas Gleixner	  boxes and media devices.
548c751e17bSThomas Gleixner
5494cb9b00fSDavid Cohenconfig X86_INTEL_MID
55043605ef1SAlan Cox	bool "Intel MID platform support"
55143605ef1SAlan Cox	depends on X86_EXTENDED_PLATFORM
552edc6bc78SDavid Cohen	depends on X86_PLATFORM_DEVICES
5531ea7c673SAlan Cox	depends on PCI
5543fda5bb4SAndy Shevchenko	depends on X86_64 || (PCI_GOANY && X86_32)
5551ea7c673SAlan Cox	depends on X86_IO_APIC
5567c9c3a1eSAlan Cox	select SFI
5574cb9b00fSDavid Cohen	select I2C
5587c9c3a1eSAlan Cox	select DW_APB_TIMER
5591ea7c673SAlan Cox	select APB_TIMER
5601ea7c673SAlan Cox	select INTEL_SCU_IPC
56115a713dfSMika Westerberg	select MFD_INTEL_MSIC
5621ea7c673SAlan Cox	---help---
5634cb9b00fSDavid Cohen	  Select to build a kernel capable of supporting Intel MID (Mobile
5644cb9b00fSDavid Cohen	  Internet Device) platform systems which do not have the PCI legacy
5654cb9b00fSDavid Cohen	  interfaces. If you are building for a PC class system say N here.
5661ea7c673SAlan Cox
5674cb9b00fSDavid Cohen	  Intel MID platforms are based on an Intel processor and chipset which
5684cb9b00fSDavid Cohen	  consume less power than most of the x86 derivatives.
56943605ef1SAlan Cox
5708bbc2a13SBryan O'Donoghueconfig X86_INTEL_QUARK
5718bbc2a13SBryan O'Donoghue	bool "Intel Quark platform support"
5728bbc2a13SBryan O'Donoghue	depends on X86_32
5738bbc2a13SBryan O'Donoghue	depends on X86_EXTENDED_PLATFORM
5748bbc2a13SBryan O'Donoghue	depends on X86_PLATFORM_DEVICES
5758bbc2a13SBryan O'Donoghue	depends on X86_TSC
5768bbc2a13SBryan O'Donoghue	depends on PCI
5778bbc2a13SBryan O'Donoghue	depends on PCI_GOANY
5788bbc2a13SBryan O'Donoghue	depends on X86_IO_APIC
5798bbc2a13SBryan O'Donoghue	select IOSF_MBI
5808bbc2a13SBryan O'Donoghue	select INTEL_IMR
5819ab6eb51SAndy Shevchenko	select COMMON_CLK
5828bbc2a13SBryan O'Donoghue	---help---
5838bbc2a13SBryan O'Donoghue	  Select to include support for Quark X1000 SoC.
5848bbc2a13SBryan O'Donoghue	  Say Y here if you have a Quark based system such as the Arduino
5858bbc2a13SBryan O'Donoghue	  compatible Intel Galileo.
5868bbc2a13SBryan O'Donoghue
5873d48aab1SMika Westerbergconfig X86_INTEL_LPSS
5883d48aab1SMika Westerberg	bool "Intel Low Power Subsystem Support"
589eebb3e8dSAndy Shevchenko	depends on X86 && ACPI
5903d48aab1SMika Westerberg	select COMMON_CLK
5910f531431SMathias Nyman	select PINCTRL
592eebb3e8dSAndy Shevchenko	select IOSF_MBI
5933d48aab1SMika Westerberg	---help---
5943d48aab1SMika Westerberg	  Select to build support for Intel Low Power Subsystem such as
5953d48aab1SMika Westerberg	  found on Intel Lynxpoint PCH. Selecting this option enables
5960f531431SMathias Nyman	  things like clock tree (common clock framework) and pincontrol
5970f531431SMathias Nyman	  which are needed by the LPSS peripheral drivers.
5983d48aab1SMika Westerberg
59992082a88SKen Xueconfig X86_AMD_PLATFORM_DEVICE
60092082a88SKen Xue	bool "AMD ACPI2Platform devices support"
60192082a88SKen Xue	depends on ACPI
60292082a88SKen Xue	select COMMON_CLK
60392082a88SKen Xue	select PINCTRL
60492082a88SKen Xue	---help---
60592082a88SKen Xue	  Select to interpret AMD specific ACPI device to platform device
60692082a88SKen Xue	  such as I2C, UART, GPIO found on AMD Carrizo and later chipsets.
60792082a88SKen Xue	  I2C and UART depend on COMMON_CLK to set clock. GPIO driver is
60892082a88SKen Xue	  implemented under PINCTRL subsystem.
60992082a88SKen Xue
610ced3ce76SDavid E. Boxconfig IOSF_MBI
611ced3ce76SDavid E. Box	tristate "Intel SoC IOSF Sideband support for SoC platforms"
612ced3ce76SDavid E. Box	depends on PCI
613ced3ce76SDavid E. Box	---help---
614ced3ce76SDavid E. Box	  This option enables sideband register access support for Intel SoC
615ced3ce76SDavid E. Box	  platforms. On these platforms the IOSF sideband is used in lieu of
616ced3ce76SDavid E. Box	  MSR's for some register accesses, mostly but not limited to thermal
617ced3ce76SDavid E. Box	  and power. Drivers may query the availability of this device to
618ced3ce76SDavid E. Box	  determine if they need the sideband in order to work on these
619ced3ce76SDavid E. Box	  platforms. The sideband is available on the following SoC products.
620ced3ce76SDavid E. Box	  This list is not meant to be exclusive.
621ced3ce76SDavid E. Box	   - BayTrail
622ced3ce76SDavid E. Box	   - Braswell
623ced3ce76SDavid E. Box	   - Quark
624ced3ce76SDavid E. Box
625ced3ce76SDavid E. Box	  You should say Y if you are running a kernel on one of these SoC's.
626ced3ce76SDavid E. Box
627ed2226bdSDavid E. Boxconfig IOSF_MBI_DEBUG
628ed2226bdSDavid E. Box	bool "Enable IOSF sideband access through debugfs"
629ed2226bdSDavid E. Box	depends on IOSF_MBI && DEBUG_FS
630ed2226bdSDavid E. Box	---help---
631ed2226bdSDavid E. Box	  Select this option to expose the IOSF sideband access registers (MCR,
632ed2226bdSDavid E. Box	  MDR, MCRX) through debugfs to write and read register information from
633ed2226bdSDavid E. Box	  different units on the SoC. This is most useful for obtaining device
634ed2226bdSDavid E. Box	  state information for debug and analysis. As this is a general access
635ed2226bdSDavid E. Box	  mechanism, users of this option would have specific knowledge of the
636ed2226bdSDavid E. Box	  device they want to access.
637ed2226bdSDavid E. Box
638ed2226bdSDavid E. Box	  If you don't require the option or are in doubt, say N.
639ed2226bdSDavid E. Box
640c5c606d9SRavikiran G Thirumalaiconfig X86_RDC321X
641c5c606d9SRavikiran G Thirumalai	bool "RDC R-321x SoC"
642506f1d07SSam Ravnborg	depends on X86_32
643c5c606d9SRavikiran G Thirumalai	depends on X86_EXTENDED_PLATFORM
644c5c606d9SRavikiran G Thirumalai	select M486
645c5c606d9SRavikiran G Thirumalai	select X86_REBOOTFIXUPS
646c5c606d9SRavikiran G Thirumalai	---help---
647c5c606d9SRavikiran G Thirumalai	  This option is needed for RDC R-321x system-on-chip, also known
648c5c606d9SRavikiran G Thirumalai	  as R-8610-(G).
649c5c606d9SRavikiran G Thirumalai	  If you don't have one of these chips, you should say N here.
650c5c606d9SRavikiran G Thirumalai
651e0c7ae37SIngo Molnarconfig X86_32_NON_STANDARD
6529c398017SIngo Molnar	bool "Support non-standard 32-bit SMP architectures"
6539c398017SIngo Molnar	depends on X86_32 && SMP
654c5c606d9SRavikiran G Thirumalai	depends on X86_EXTENDED_PLATFORM
6558f9ca475SIngo Molnar	---help---
656b5660ba7SH. Peter Anvin	  This option compiles in the bigsmp and STA2X11 default
657b5660ba7SH. Peter Anvin	  subarchitectures.  It is intended for a generic binary
658b5660ba7SH. Peter Anvin	  kernel. If you select them all, kernel will probe it one by
659b5660ba7SH. Peter Anvin	  one and will fallback to default.
660d49c4288SYinghai Lu
661c5c606d9SRavikiran G Thirumalai# Alphabetically sorted list of Non standard 32 bit platforms
662d49c4288SYinghai Lu
663d949f36fSLinus Torvaldsconfig X86_SUPPORTS_MEMORY_FAILURE
6646fc108a0SJan Beulich	def_bool y
665d949f36fSLinus Torvalds	# MCE code calls memory_failure():
666d949f36fSLinus Torvalds	depends on X86_MCE
667d949f36fSLinus Torvalds	# On 32-bit this adds too big of NODES_SHIFT and we run out of page flags:
668d949f36fSLinus Torvalds	# On 32-bit SPARSEMEM adds too big of SECTIONS_WIDTH:
669d949f36fSLinus Torvalds	depends on X86_64 || !SPARSEMEM
670d949f36fSLinus Torvalds	select ARCH_SUPPORTS_MEMORY_FAILURE
671d949f36fSLinus Torvalds
67283125a3aSAlessandro Rubiniconfig STA2X11
67383125a3aSAlessandro Rubini	bool "STA2X11 Companion Chip Support"
67483125a3aSAlessandro Rubini	depends on X86_32_NON_STANDARD && PCI
67583125a3aSAlessandro Rubini	select X86_DEV_DMA_OPS
67683125a3aSAlessandro Rubini	select X86_DMA_REMAP
67783125a3aSAlessandro Rubini	select SWIOTLB
67883125a3aSAlessandro Rubini	select MFD_STA2X11
6790145071bSLinus Walleij	select GPIOLIB
68083125a3aSAlessandro Rubini	default n
68183125a3aSAlessandro Rubini	---help---
68283125a3aSAlessandro Rubini	  This adds support for boards based on the STA2X11 IO-Hub,
68383125a3aSAlessandro Rubini	  a.k.a. "ConneXt". The chip is used in place of the standard
68483125a3aSAlessandro Rubini	  PC chipset, so all "standard" peripherals are missing. If this
68583125a3aSAlessandro Rubini	  option is selected the kernel will still be able to boot on
68683125a3aSAlessandro Rubini	  standard PC machines.
68783125a3aSAlessandro Rubini
68882148d1dSShérabconfig X86_32_IRIS
68982148d1dSShérab	tristate "Eurobraille/Iris poweroff module"
69082148d1dSShérab	depends on X86_32
69182148d1dSShérab	---help---
69282148d1dSShérab	  The Iris machines from EuroBraille do not have APM or ACPI support
69382148d1dSShérab	  to shut themselves down properly.  A special I/O sequence is
69482148d1dSShérab	  needed to do so, which is what this module does at
69582148d1dSShérab	  kernel shutdown.
69682148d1dSShérab
69782148d1dSShérab	  This is only for Iris machines from EuroBraille.
69882148d1dSShérab
69982148d1dSShérab	  If unused, say N.
70082148d1dSShérab
701ae1e9130SIngo Molnarconfig SCHED_OMIT_FRAME_POINTER
7023c2362e6SHarvey Harrison	def_bool y
7033c2362e6SHarvey Harrison	prompt "Single-depth WCHAN output"
704a87d0914SKen Chen	depends on X86
7058f9ca475SIngo Molnar	---help---
706506f1d07SSam Ravnborg	  Calculate simpler /proc/<PID>/wchan values. If this option
707506f1d07SSam Ravnborg	  is disabled then wchan values will recurse back to the
708506f1d07SSam Ravnborg	  caller function. This provides more accurate wchan values,
709506f1d07SSam Ravnborg	  at the expense of slightly more scheduling overhead.
710506f1d07SSam Ravnborg
711506f1d07SSam Ravnborg	  If in doubt, say "Y".
712506f1d07SSam Ravnborg
7136276a074SBorislav Petkovmenuconfig HYPERVISOR_GUEST
7146276a074SBorislav Petkov	bool "Linux guest support"
7158f9ca475SIngo Molnar	---help---
7166276a074SBorislav Petkov	  Say Y here to enable options for running Linux under various hyper-
7176276a074SBorislav Petkov	  visors. This option enables basic hypervisor detection and platform
7186276a074SBorislav Petkov	  setup.
719506f1d07SSam Ravnborg
7206276a074SBorislav Petkov	  If you say N, all options in this submenu will be skipped and
7216276a074SBorislav Petkov	  disabled, and Linux guest support won't be built in.
722506f1d07SSam Ravnborg
7236276a074SBorislav Petkovif HYPERVISOR_GUEST
724506f1d07SSam Ravnborg
725e61bd94aSEduardo Pereira Habkostconfig PARAVIRT
726e61bd94aSEduardo Pereira Habkost	bool "Enable paravirtualization code"
7278f9ca475SIngo Molnar	---help---
728e61bd94aSEduardo Pereira Habkost	  This changes the kernel so it can modify itself when it is run
729e61bd94aSEduardo Pereira Habkost	  under a hypervisor, potentially improving performance significantly
730e61bd94aSEduardo Pereira Habkost	  over full virtualization.  However, when run without a hypervisor
731e61bd94aSEduardo Pereira Habkost	  the kernel is theoretically slower and slightly larger.
732e61bd94aSEduardo Pereira Habkost
7336276a074SBorislav Petkovconfig PARAVIRT_DEBUG
7346276a074SBorislav Petkov	bool "paravirt-ops debugging"
7356276a074SBorislav Petkov	depends on PARAVIRT && DEBUG_KERNEL
7366276a074SBorislav Petkov	---help---
7376276a074SBorislav Petkov	  Enable to debug paravirt_ops internals.  Specifically, BUG if
7386276a074SBorislav Petkov	  a paravirt_op is missing when it is called.
7396276a074SBorislav Petkov
740b4ecc126SJeremy Fitzhardingeconfig PARAVIRT_SPINLOCKS
741b4ecc126SJeremy Fitzhardinge	bool "Paravirtualization layer for spinlocks"
7426ea30386SKees Cook	depends on PARAVIRT && SMP
743b4ecc126SJeremy Fitzhardinge	---help---
744b4ecc126SJeremy Fitzhardinge	  Paravirtualized spinlocks allow a pvops backend to replace the
745b4ecc126SJeremy Fitzhardinge	  spinlock implementation with something virtualization-friendly
746b4ecc126SJeremy Fitzhardinge	  (for example, block the virtual CPU rather than spinning).
747b4ecc126SJeremy Fitzhardinge
7484c4e4f61SRaghavendra K T	  It has a minimal impact on native kernels and gives a nice performance
7494c4e4f61SRaghavendra K T	  benefit on paravirtualized KVM / Xen kernels.
750b4ecc126SJeremy Fitzhardinge
7514c4e4f61SRaghavendra K T	  If you are unsure how to answer this question, answer Y.
752b4ecc126SJeremy Fitzhardinge
75345e898b7SWaiman Longconfig QUEUED_LOCK_STAT
75445e898b7SWaiman Long	bool "Paravirt queued spinlock statistics"
755cfd8983fSPeter Zijlstra	depends on PARAVIRT_SPINLOCKS && DEBUG_FS
75645e898b7SWaiman Long	---help---
75745e898b7SWaiman Long	  Enable the collection of statistical data on the slowpath
75845e898b7SWaiman Long	  behavior of paravirtualized queued spinlocks and report
75945e898b7SWaiman Long	  them on debugfs.
76045e898b7SWaiman Long
7616276a074SBorislav Petkovsource "arch/x86/xen/Kconfig"
7626276a074SBorislav Petkov
7636276a074SBorislav Petkovconfig KVM_GUEST
7646276a074SBorislav Petkov	bool "KVM Guest support (including kvmclock)"
7656276a074SBorislav Petkov	depends on PARAVIRT
7666276a074SBorislav Petkov	select PARAVIRT_CLOCK
7676276a074SBorislav Petkov	default y
7686276a074SBorislav Petkov	---help---
7696276a074SBorislav Petkov	  This option enables various optimizations for running under the KVM
7706276a074SBorislav Petkov	  hypervisor. It includes a paravirtualized clock, so that instead
7716276a074SBorislav Petkov	  of relying on a PIT (or probably other) emulation by the
7726276a074SBorislav Petkov	  underlying device model, the host provides the guest with
7736276a074SBorislav Petkov	  timing infrastructure such as time of day, and system time
7746276a074SBorislav Petkov
7751e20eb85SSrivatsa Vaddagiriconfig KVM_DEBUG_FS
7761e20eb85SSrivatsa Vaddagiri	bool "Enable debug information for KVM Guests in debugfs"
7771e20eb85SSrivatsa Vaddagiri	depends on KVM_GUEST && DEBUG_FS
7781e20eb85SSrivatsa Vaddagiri	default n
7791e20eb85SSrivatsa Vaddagiri	---help---
7801e20eb85SSrivatsa Vaddagiri	  This option enables collection of various statistics for KVM guest.
7811e20eb85SSrivatsa Vaddagiri	  Statistics are displayed in debugfs filesystem. Enabling this option
7821e20eb85SSrivatsa Vaddagiri	  may incur significant overhead.
7831e20eb85SSrivatsa Vaddagiri
7846276a074SBorislav Petkovconfig PARAVIRT_TIME_ACCOUNTING
7856276a074SBorislav Petkov	bool "Paravirtual steal time accounting"
7866276a074SBorislav Petkov	depends on PARAVIRT
7876276a074SBorislav Petkov	default n
7886276a074SBorislav Petkov	---help---
7896276a074SBorislav Petkov	  Select this option to enable fine granularity task steal time
7906276a074SBorislav Petkov	  accounting. Time spent executing other tasks in parallel with
7916276a074SBorislav Petkov	  the current vCPU is discounted from the vCPU power. To account for
7926276a074SBorislav Petkov	  that, there can be a small performance impact.
7936276a074SBorislav Petkov
7946276a074SBorislav Petkov	  If in doubt, say N here.
7956276a074SBorislav Petkov
7967af192c9SGerd Hoffmannconfig PARAVIRT_CLOCK
7977af192c9SGerd Hoffmann	bool
7987af192c9SGerd Hoffmann
7994a362601SJan Kiszkaconfig JAILHOUSE_GUEST
8004a362601SJan Kiszka	bool "Jailhouse non-root cell support"
801*abde587bSArnd Bergmann	depends on X86_64 && PCI
80287e65d05SJan Kiszka	select X86_PM_TIMER
8034a362601SJan Kiszka	---help---
8044a362601SJan Kiszka	  This option allows to run Linux as guest in a Jailhouse non-root
8054a362601SJan Kiszka	  cell. You can leave this option disabled if you only want to start
8064a362601SJan Kiszka	  Jailhouse and run Linux afterwards in the root cell.
8074a362601SJan Kiszka
8086276a074SBorislav Petkovendif #HYPERVISOR_GUEST
80997349135SJeremy Fitzhardinge
81008677214SYinghai Luconfig NO_BOOTMEM
811774ea0bcSYinghai Lu	def_bool y
81208677214SYinghai Lu
813506f1d07SSam Ravnborgsource "arch/x86/Kconfig.cpu"
814506f1d07SSam Ravnborg
815506f1d07SSam Ravnborgconfig HPET_TIMER
8163c2362e6SHarvey Harrison	def_bool X86_64
817506f1d07SSam Ravnborg	prompt "HPET Timer Support" if X86_32
8188f9ca475SIngo Molnar	---help---
819506f1d07SSam Ravnborg	  Use the IA-PC HPET (High Precision Event Timer) to manage
820506f1d07SSam Ravnborg	  time in preference to the PIT and RTC, if a HPET is
821506f1d07SSam Ravnborg	  present.
822506f1d07SSam Ravnborg	  HPET is the next generation timer replacing legacy 8254s.
823506f1d07SSam Ravnborg	  The HPET provides a stable time base on SMP
824506f1d07SSam Ravnborg	  systems, unlike the TSC, but it is more expensive to access,
8254e7f9df2SMichael S. Tsirkin	  as it is off-chip.  The interface used is documented
8264e7f9df2SMichael S. Tsirkin	  in the HPET spec, revision 1.
827506f1d07SSam Ravnborg
828506f1d07SSam Ravnborg	  You can safely choose Y here.  However, HPET will only be
829506f1d07SSam Ravnborg	  activated if the platform and the BIOS support this feature.
830506f1d07SSam Ravnborg	  Otherwise the 8254 will be used for timing services.
831506f1d07SSam Ravnborg
832506f1d07SSam Ravnborg	  Choose N to continue using the legacy 8254 timer.
833506f1d07SSam Ravnborg
834506f1d07SSam Ravnborgconfig HPET_EMULATE_RTC
8353c2362e6SHarvey Harrison	def_bool y
8369d8af78bSBernhard Walle	depends on HPET_TIMER && (RTC=y || RTC=m || RTC_DRV_CMOS=m || RTC_DRV_CMOS=y)
837506f1d07SSam Ravnborg
838bb24c471SJacob Panconfig APB_TIMER
839933b9463SAlan Cox       def_bool y if X86_INTEL_MID
840933b9463SAlan Cox       prompt "Intel MID APB Timer Support" if X86_INTEL_MID
84106c3df49SJamie Iles       select DW_APB_TIMER
842a0c3832aSAlan Cox       depends on X86_INTEL_MID && SFI
843bb24c471SJacob Pan       help
844bb24c471SJacob Pan         APB timer is the replacement for 8254, HPET on X86 MID platforms.
845bb24c471SJacob Pan         The APBT provides a stable time base on SMP
846bb24c471SJacob Pan         systems, unlike the TSC, but it is more expensive to access,
847bb24c471SJacob Pan         as it is off-chip. APB timers are always running regardless of CPU
848bb24c471SJacob Pan         C states, they are used as per CPU clockevent device when possible.
849bb24c471SJacob Pan
8506a108a14SDavid Rientjes# Mark as expert because too many people got it wrong.
851506f1d07SSam Ravnborg# The code disables itself when not needed.
8527ae9392cSThomas Petazzoniconfig DMI
8537ae9392cSThomas Petazzoni	default y
854cf074402SArd Biesheuvel	select DMI_SCAN_MACHINE_NON_EFI_FALLBACK
8556a108a14SDavid Rientjes	bool "Enable DMI scanning" if EXPERT
8568f9ca475SIngo Molnar	---help---
8577ae9392cSThomas Petazzoni	  Enabled scanning of DMI to identify machine quirks. Say Y
8587ae9392cSThomas Petazzoni	  here unless you have verified that your setup is not
8597ae9392cSThomas Petazzoni	  affected by entries in the DMI blacklist. Required by PNP
8607ae9392cSThomas Petazzoni	  BIOS code.
8617ae9392cSThomas Petazzoni
862506f1d07SSam Ravnborgconfig GART_IOMMU
86338901f1cSAndi Kleen	bool "Old AMD GART IOMMU support"
864506f1d07SSam Ravnborg	select SWIOTLB
86523ac4ae8SAndreas Herrmann	depends on X86_64 && PCI && AMD_NB
8668f9ca475SIngo Molnar	---help---
867ced3c42cSIngo Molnar	  Provides a driver for older AMD Athlon64/Opteron/Turion/Sempron
868ced3c42cSIngo Molnar	  GART based hardware IOMMUs.
869ced3c42cSIngo Molnar
870ced3c42cSIngo Molnar	  The GART supports full DMA access for devices with 32-bit access
871ced3c42cSIngo Molnar	  limitations, on systems with more than 3 GB. This is usually needed
872ced3c42cSIngo Molnar	  for USB, sound, many IDE/SATA chipsets and some other devices.
873ced3c42cSIngo Molnar
874ced3c42cSIngo Molnar	  Newer systems typically have a modern AMD IOMMU, supported via
875ced3c42cSIngo Molnar	  the CONFIG_AMD_IOMMU=y config option.
876ced3c42cSIngo Molnar
877ced3c42cSIngo Molnar	  In normal configurations this driver is only active when needed:
878ced3c42cSIngo Molnar	  there's more than 3 GB of memory and the system contains a
879ced3c42cSIngo Molnar	  32-bit limited device.
880ced3c42cSIngo Molnar
881ced3c42cSIngo Molnar	  If unsure, say Y.
882506f1d07SSam Ravnborg
883506f1d07SSam Ravnborgconfig CALGARY_IOMMU
884506f1d07SSam Ravnborg	bool "IBM Calgary IOMMU support"
885506f1d07SSam Ravnborg	select SWIOTLB
8866ea30386SKees Cook	depends on X86_64 && PCI
8878f9ca475SIngo Molnar	---help---
888506f1d07SSam Ravnborg	  Support for hardware IOMMUs in IBM's xSeries x366 and x460
889506f1d07SSam Ravnborg	  systems. Needed to run systems with more than 3GB of memory
890506f1d07SSam Ravnborg	  properly with 32-bit PCI devices that do not support DAC
891506f1d07SSam Ravnborg	  (Double Address Cycle). Calgary also supports bus level
892506f1d07SSam Ravnborg	  isolation, where all DMAs pass through the IOMMU.  This
893506f1d07SSam Ravnborg	  prevents them from going anywhere except their intended
894506f1d07SSam Ravnborg	  destination. This catches hard-to-find kernel bugs and
895506f1d07SSam Ravnborg	  mis-behaving drivers and devices that do not use the DMA-API
896506f1d07SSam Ravnborg	  properly to set up their DMA buffers.  The IOMMU can be
897506f1d07SSam Ravnborg	  turned off at boot time with the iommu=off parameter.
898506f1d07SSam Ravnborg	  Normally the kernel will make the right choice by itself.
899506f1d07SSam Ravnborg	  If unsure, say Y.
900506f1d07SSam Ravnborg
901506f1d07SSam Ravnborgconfig CALGARY_IOMMU_ENABLED_BY_DEFAULT
9023c2362e6SHarvey Harrison	def_bool y
9033c2362e6SHarvey Harrison	prompt "Should Calgary be enabled by default?"
904506f1d07SSam Ravnborg	depends on CALGARY_IOMMU
9058f9ca475SIngo Molnar	---help---
906506f1d07SSam Ravnborg	  Should Calgary be enabled by default? if you choose 'y', Calgary
907506f1d07SSam Ravnborg	  will be used (if it exists). If you choose 'n', Calgary will not be
908506f1d07SSam Ravnborg	  used even if it exists. If you choose 'n' and would like to use
909506f1d07SSam Ravnborg	  Calgary anyway, pass 'iommu=calgary' on the kernel command line.
910506f1d07SSam Ravnborg	  If unsure, say Y.
911506f1d07SSam Ravnborg
912506f1d07SSam Ravnborg# need this always selected by IOMMU for the VIA workaround
913506f1d07SSam Ravnborgconfig SWIOTLB
914a1afd01cSJoerg Roedel	def_bool y if X86_64
9158f9ca475SIngo Molnar	---help---
916506f1d07SSam Ravnborg	  Support for software bounce buffers used on x86-64 systems
9174454d327SJoe Millenbach	  which don't have a hardware IOMMU. Using this PCI devices
9184454d327SJoe Millenbach	  which can only access 32-bits of memory can be used on systems
9194454d327SJoe Millenbach	  with more than 3 GB of memory.
9204454d327SJoe Millenbach	  If unsure, say Y.
921506f1d07SSam Ravnborg
922a8522509SFUJITA Tomonoriconfig IOMMU_HELPER
9233120e25eSJan Beulich	def_bool y
9243120e25eSJan Beulich	depends on CALGARY_IOMMU || GART_IOMMU || SWIOTLB || AMD_IOMMU
925d25e26b6SLinus Torvalds
9261184dc2fSMike Travisconfig MAXSMP
927ddb0c5a6SSamuel Thibault	bool "Enable Maximum number of SMP Processors and NUMA Nodes"
9286ea30386SKees Cook	depends on X86_64 && SMP && DEBUG_KERNEL
92936f5101aSMike Travis	select CPUMASK_OFFSTACK
9308f9ca475SIngo Molnar	---help---
931ddb0c5a6SSamuel Thibault	  Enable maximum number of CPUS and NUMA Nodes for this architecture.
9321184dc2fSMike Travis	  If unsure, say N.
933506f1d07SSam Ravnborg
934506f1d07SSam Ravnborgconfig NR_CPUS
93536f5101aSMike Travis	int "Maximum number of CPUs" if SMP && !MAXSMP
9362a3313f4SMichael K. Johnson	range 2 8 if SMP && X86_32 && !X86_BIGSMP
9377bbcbd3dSThomas Gleixner	range 2 64 if SMP && X86_32 && X86_BIGSMP
9387bbcbd3dSThomas Gleixner	range 2 512 if SMP && !MAXSMP && !CPUMASK_OFFSTACK && X86_64
939b53b5edaSJosh Boyer	range 2 8192 if SMP && !MAXSMP && CPUMASK_OFFSTACK && X86_64
94078637a97SMike Travis	default "1" if !SMP
941b53b5edaSJosh Boyer	default "8192" if MAXSMP
942b5660ba7SH. Peter Anvin	default "32" if SMP && X86_BIGSMP
943c5c19941SKirill A. Shutemov	default "8" if SMP && X86_32
944c5c19941SKirill A. Shutemov	default "64" if SMP
9458f9ca475SIngo Molnar	---help---
946506f1d07SSam Ravnborg	  This allows you to specify the maximum number of CPUs which this
947bb61ccc7SJosh Boyer	  kernel will support.  If CPUMASK_OFFSTACK is enabled, the maximum
948cad14bb9SKirill A. Shutemov	  supported value is 8192, otherwise the maximum value is 512.  The
949506f1d07SSam Ravnborg	  minimum value which makes sense is 2.
950506f1d07SSam Ravnborg
951506f1d07SSam Ravnborg	  This is purely to save memory - each supported CPU adds
952506f1d07SSam Ravnborg	  approximately eight kilobytes to the kernel image.
953506f1d07SSam Ravnborg
954506f1d07SSam Ravnborgconfig SCHED_SMT
955506f1d07SSam Ravnborg	bool "SMT (Hyperthreading) scheduler support"
956c8e56d20SBorislav Petkov	depends on SMP
9578f9ca475SIngo Molnar	---help---
958506f1d07SSam Ravnborg	  SMT scheduler support improves the CPU scheduler's decision making
959506f1d07SSam Ravnborg	  when dealing with Intel Pentium 4 chips with HyperThreading at a
960506f1d07SSam Ravnborg	  cost of slightly increased overhead in some places. If unsure say
961506f1d07SSam Ravnborg	  N here.
962506f1d07SSam Ravnborg
963506f1d07SSam Ravnborgconfig SCHED_MC
9643c2362e6SHarvey Harrison	def_bool y
9653c2362e6SHarvey Harrison	prompt "Multi-core scheduler support"
966c8e56d20SBorislav Petkov	depends on SMP
9678f9ca475SIngo Molnar	---help---
968506f1d07SSam Ravnborg	  Multi-core scheduler support improves the CPU scheduler's decision
969506f1d07SSam Ravnborg	  making when dealing with multi-core CPU chips at a cost of slightly
970506f1d07SSam Ravnborg	  increased overhead in some places. If unsure say N here.
971506f1d07SSam Ravnborg
972de966cf4STim Chenconfig SCHED_MC_PRIO
973de966cf4STim Chen	bool "CPU core priorities scheduler support"
9740a21fc12SIngo Molnar	depends on SCHED_MC && CPU_SUP_INTEL
9750a21fc12SIngo Molnar	select X86_INTEL_PSTATE
9760a21fc12SIngo Molnar	select CPU_FREQ
977de966cf4STim Chen	default y
9785e76b2abSTim Chen	---help---
979de966cf4STim Chen	  Intel Turbo Boost Max Technology 3.0 enabled CPUs have a
980de966cf4STim Chen	  core ordering determined at manufacturing time, which allows
981de966cf4STim Chen	  certain cores to reach higher turbo frequencies (when running
982de966cf4STim Chen	  single threaded workloads) than others.
983de966cf4STim Chen
984de966cf4STim Chen	  Enabling this kernel feature teaches the scheduler about
985de966cf4STim Chen	  the TBM3 (aka ITMT) priority order of the CPU cores and adjusts the
986de966cf4STim Chen	  scheduler's CPU selection logic accordingly, so that higher
987de966cf4STim Chen	  overall system performance can be achieved.
988de966cf4STim Chen
989de966cf4STim Chen	  This feature will have no effect on CPUs without this feature.
990de966cf4STim Chen
991de966cf4STim Chen	  If unsure say Y here.
9925e76b2abSTim Chen
993506f1d07SSam Ravnborgsource "kernel/Kconfig.preempt"
994506f1d07SSam Ravnborg
99530b8b006SThomas Gleixnerconfig UP_LATE_INIT
99630b8b006SThomas Gleixner       def_bool y
997ba360f88SThomas Gleixner       depends on !SMP && X86_LOCAL_APIC
99830b8b006SThomas Gleixner
999506f1d07SSam Ravnborgconfig X86_UP_APIC
100050849eefSJan Beulich	bool "Local APIC support on uniprocessors" if !PCI_MSI
100150849eefSJan Beulich	default PCI_MSI
100238a1dfdaSBryan O'Donoghue	depends on X86_32 && !SMP && !X86_32_NON_STANDARD
10038f9ca475SIngo Molnar	---help---
1004506f1d07SSam Ravnborg	  A local APIC (Advanced Programmable Interrupt Controller) is an
1005506f1d07SSam Ravnborg	  integrated interrupt controller in the CPU. If you have a single-CPU
1006506f1d07SSam Ravnborg	  system which has a processor with a local APIC, you can say Y here to
1007506f1d07SSam Ravnborg	  enable and use it. If you say Y here even though your machine doesn't
1008506f1d07SSam Ravnborg	  have a local APIC, then the kernel will still run with no slowdown at
1009506f1d07SSam Ravnborg	  all. The local APIC supports CPU-generated self-interrupts (timer,
1010506f1d07SSam Ravnborg	  performance counters), and the NMI watchdog which detects hard
1011506f1d07SSam Ravnborg	  lockups.
1012506f1d07SSam Ravnborg
1013506f1d07SSam Ravnborgconfig X86_UP_IOAPIC
1014506f1d07SSam Ravnborg	bool "IO-APIC support on uniprocessors"
1015506f1d07SSam Ravnborg	depends on X86_UP_APIC
10168f9ca475SIngo Molnar	---help---
1017506f1d07SSam Ravnborg	  An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an
1018506f1d07SSam Ravnborg	  SMP-capable replacement for PC-style interrupt controllers. Most
1019506f1d07SSam Ravnborg	  SMP systems and many recent uniprocessor systems have one.
1020506f1d07SSam Ravnborg
1021506f1d07SSam Ravnborg	  If you have a single-CPU system with an IO-APIC, you can say Y here
1022506f1d07SSam Ravnborg	  to use it. If you say Y here even though your machine doesn't have
1023506f1d07SSam Ravnborg	  an IO-APIC, then the kernel will still run with no slowdown at all.
1024506f1d07SSam Ravnborg
1025506f1d07SSam Ravnborgconfig X86_LOCAL_APIC
10263c2362e6SHarvey Harrison	def_bool y
10270dbc6078SThomas Petazzoni	depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC || PCI_MSI
1028b5dc8e6cSJiang Liu	select IRQ_DOMAIN_HIERARCHY
102952f518a3SJiang Liu	select PCI_MSI_IRQ_DOMAIN if PCI_MSI
1030506f1d07SSam Ravnborg
1031506f1d07SSam Ravnborgconfig X86_IO_APIC
1032b1da1e71SJan Beulich	def_bool y
1033b1da1e71SJan Beulich	depends on X86_LOCAL_APIC || X86_UP_IOAPIC
1034506f1d07SSam Ravnborg
103541b9eb26SStefan Assmannconfig X86_REROUTE_FOR_BROKEN_BOOT_IRQS
103641b9eb26SStefan Assmann	bool "Reroute for broken boot IRQs"
103741b9eb26SStefan Assmann	depends on X86_IO_APIC
10388f9ca475SIngo Molnar	---help---
103941b9eb26SStefan Assmann	  This option enables a workaround that fixes a source of
104041b9eb26SStefan Assmann	  spurious interrupts. This is recommended when threaded
104141b9eb26SStefan Assmann	  interrupt handling is used on systems where the generation of
104241b9eb26SStefan Assmann	  superfluous "boot interrupts" cannot be disabled.
104341b9eb26SStefan Assmann
104441b9eb26SStefan Assmann	  Some chipsets generate a legacy INTx "boot IRQ" when the IRQ
104541b9eb26SStefan Assmann	  entry in the chipset's IO-APIC is masked (as, e.g. the RT
104641b9eb26SStefan Assmann	  kernel does during interrupt handling). On chipsets where this
104741b9eb26SStefan Assmann	  boot IRQ generation cannot be disabled, this workaround keeps
104841b9eb26SStefan Assmann	  the original IRQ line masked so that only the equivalent "boot
104941b9eb26SStefan Assmann	  IRQ" is delivered to the CPUs. The workaround also tells the
105041b9eb26SStefan Assmann	  kernel to set up the IRQ handler on the boot IRQ line. In this
105141b9eb26SStefan Assmann	  way only one interrupt is delivered to the kernel. Otherwise
105241b9eb26SStefan Assmann	  the spurious second interrupt may cause the kernel to bring
105341b9eb26SStefan Assmann	  down (vital) interrupt lines.
105441b9eb26SStefan Assmann
105541b9eb26SStefan Assmann	  Only affects "broken" chipsets. Interrupt sharing may be
105641b9eb26SStefan Assmann	  increased on these systems.
105741b9eb26SStefan Assmann
1058506f1d07SSam Ravnborgconfig X86_MCE
1059bab9bc65SAndi Kleen	bool "Machine Check / overheating reporting"
1060648ed940SChen, Gong	select GENERIC_ALLOCATOR
1061e57dbaf7SBorislav Petkov	default y
1062506f1d07SSam Ravnborg	---help---
1063bab9bc65SAndi Kleen	  Machine Check support allows the processor to notify the
1064bab9bc65SAndi Kleen	  kernel if it detects a problem (e.g. overheating, data corruption).
1065506f1d07SSam Ravnborg	  The action the kernel takes depends on the severity of the problem,
1066bab9bc65SAndi Kleen	  ranging from warning messages to halting the machine.
10674efc0670SAndi Kleen
10685de97c9fSTony Luckconfig X86_MCELOG_LEGACY
10695de97c9fSTony Luck	bool "Support for deprecated /dev/mcelog character device"
10705de97c9fSTony Luck	depends on X86_MCE
10715de97c9fSTony Luck	---help---
10725de97c9fSTony Luck	  Enable support for /dev/mcelog which is needed by the old mcelog
10735de97c9fSTony Luck	  userspace logging daemon. Consider switching to the new generation
10745de97c9fSTony Luck	  rasdaemon solution.
10755de97c9fSTony Luck
1076506f1d07SSam Ravnborgconfig X86_MCE_INTEL
10773c2362e6SHarvey Harrison	def_bool y
10783c2362e6SHarvey Harrison	prompt "Intel MCE features"
1079c1ebf835SAndi Kleen	depends on X86_MCE && X86_LOCAL_APIC
10808f9ca475SIngo Molnar	---help---
1081506f1d07SSam Ravnborg	   Additional support for intel specific MCE features such as
1082506f1d07SSam Ravnborg	   the thermal monitor.
1083506f1d07SSam Ravnborg
1084506f1d07SSam Ravnborgconfig X86_MCE_AMD
10853c2362e6SHarvey Harrison	def_bool y
10863c2362e6SHarvey Harrison	prompt "AMD MCE features"
1087f5382de9SYazen Ghannam	depends on X86_MCE && X86_LOCAL_APIC && AMD_NB
10888f9ca475SIngo Molnar	---help---
1089506f1d07SSam Ravnborg	   Additional support for AMD specific MCE features such as
1090506f1d07SSam Ravnborg	   the DRAM Error Threshold.
1091506f1d07SSam Ravnborg
10924efc0670SAndi Kleenconfig X86_ANCIENT_MCE
10936fc108a0SJan Beulich	bool "Support for old Pentium 5 / WinChip machine checks"
1094c31d9633SAndi Kleen	depends on X86_32 && X86_MCE
10954efc0670SAndi Kleen	---help---
10964efc0670SAndi Kleen	  Include support for machine check handling on old Pentium 5 or WinChip
10975065a706SMasanari Iida	  systems. These typically need to be enabled explicitly on the command
10984efc0670SAndi Kleen	  line.
10994efc0670SAndi Kleen
1100b2762686SAndi Kleenconfig X86_MCE_THRESHOLD
1101b2762686SAndi Kleen	depends on X86_MCE_AMD || X86_MCE_INTEL
11026fc108a0SJan Beulich	def_bool y
1103b2762686SAndi Kleen
1104ea149b36SAndi Kleenconfig X86_MCE_INJECT
1105bc8e80d5SBorislav Petkov	depends on X86_MCE && X86_LOCAL_APIC && DEBUG_FS
1106ea149b36SAndi Kleen	tristate "Machine check injector support"
1107ea149b36SAndi Kleen	---help---
1108ea149b36SAndi Kleen	  Provide support for injecting machine checks for testing purposes.
1109ea149b36SAndi Kleen	  If you don't know what a machine check is and you don't do kernel
1110ea149b36SAndi Kleen	  QA it is safe to say n.
1111ea149b36SAndi Kleen
11124efc0670SAndi Kleenconfig X86_THERMAL_VECTOR
11134efc0670SAndi Kleen	def_bool y
11145bb38adcSAndi Kleen	depends on X86_MCE_INTEL
11154efc0670SAndi Kleen
111607dc900eSPeter Zijlstrasource "arch/x86/events/Kconfig"
1117e633c65aSKan Liang
11185aef51c3SAndy Lutomirskiconfig X86_LEGACY_VM86
11191e642812SIngo Molnar	bool "Legacy VM86 support"
11205aef51c3SAndy Lutomirski	default n
1121506f1d07SSam Ravnborg	depends on X86_32
11228f9ca475SIngo Molnar	---help---
11235aef51c3SAndy Lutomirski	  This option allows user programs to put the CPU into V8086
11245aef51c3SAndy Lutomirski	  mode, which is an 80286-era approximation of 16-bit real mode.
11255aef51c3SAndy Lutomirski
11265aef51c3SAndy Lutomirski	  Some very old versions of X and/or vbetool require this option
11275aef51c3SAndy Lutomirski	  for user mode setting.  Similarly, DOSEMU will use it if
11285aef51c3SAndy Lutomirski	  available to accelerate real mode DOS programs.  However, any
11295aef51c3SAndy Lutomirski	  recent version of DOSEMU, X, or vbetool should be fully
11305aef51c3SAndy Lutomirski	  functional even without kernel VM86 support, as they will all
11311e642812SIngo Molnar	  fall back to software emulation. Nevertheless, if you are using
11321e642812SIngo Molnar	  a 16-bit DOS program where 16-bit performance matters, vm86
11331e642812SIngo Molnar	  mode might be faster than emulation and you might want to
11341e642812SIngo Molnar	  enable this option.
11355aef51c3SAndy Lutomirski
11361e642812SIngo Molnar	  Note that any app that works on a 64-bit kernel is unlikely to
11371e642812SIngo Molnar	  need this option, as 64-bit kernels don't, and can't, support
11381e642812SIngo Molnar	  V8086 mode. This option is also unrelated to 16-bit protected
11391e642812SIngo Molnar	  mode and is not needed to run most 16-bit programs under Wine.
11405aef51c3SAndy Lutomirski
11411e642812SIngo Molnar	  Enabling this option increases the complexity of the kernel
11421e642812SIngo Molnar	  and slows down exception handling a tiny bit.
11435aef51c3SAndy Lutomirski
11441e642812SIngo Molnar	  If unsure, say N here.
11455aef51c3SAndy Lutomirski
11465aef51c3SAndy Lutomirskiconfig VM86
11475aef51c3SAndy Lutomirski       bool
11485aef51c3SAndy Lutomirski       default X86_LEGACY_VM86
114934273f41SH. Peter Anvin
115034273f41SH. Peter Anvinconfig X86_16BIT
115134273f41SH. Peter Anvin	bool "Enable support for 16-bit segments" if EXPERT
115234273f41SH. Peter Anvin	default y
1153a5b9e5a2SAndy Lutomirski	depends on MODIFY_LDT_SYSCALL
115434273f41SH. Peter Anvin	---help---
115534273f41SH. Peter Anvin	  This option is required by programs like Wine to run 16-bit
115634273f41SH. Peter Anvin	  protected mode legacy code on x86 processors.  Disabling
115734273f41SH. Peter Anvin	  this option saves about 300 bytes on i386, or around 6K text
115834273f41SH. Peter Anvin	  plus 16K runtime memory on x86-64,
115934273f41SH. Peter Anvin
116034273f41SH. Peter Anvinconfig X86_ESPFIX32
116134273f41SH. Peter Anvin	def_bool y
116234273f41SH. Peter Anvin	depends on X86_16BIT && X86_32
1163506f1d07SSam Ravnborg
1164197725deSH. Peter Anvinconfig X86_ESPFIX64
1165197725deSH. Peter Anvin	def_bool y
116634273f41SH. Peter Anvin	depends on X86_16BIT && X86_64
1167506f1d07SSam Ravnborg
11681ad83c85SAndy Lutomirskiconfig X86_VSYSCALL_EMULATION
11691ad83c85SAndy Lutomirski       bool "Enable vsyscall emulation" if EXPERT
11701ad83c85SAndy Lutomirski       default y
11711ad83c85SAndy Lutomirski       depends on X86_64
11721ad83c85SAndy Lutomirski       ---help---
11731ad83c85SAndy Lutomirski	 This enables emulation of the legacy vsyscall page.  Disabling
11741ad83c85SAndy Lutomirski	 it is roughly equivalent to booting with vsyscall=none, except
11751ad83c85SAndy Lutomirski	 that it will also disable the helpful warning if a program
11761ad83c85SAndy Lutomirski	 tries to use a vsyscall.  With this option set to N, offending
11771ad83c85SAndy Lutomirski	 programs will just segfault, citing addresses of the form
11781ad83c85SAndy Lutomirski	 0xffffffffff600?00.
11791ad83c85SAndy Lutomirski
11801ad83c85SAndy Lutomirski	 This option is required by many programs built before 2013, and
11811ad83c85SAndy Lutomirski	 care should be used even with newer programs if set to N.
11821ad83c85SAndy Lutomirski
11831ad83c85SAndy Lutomirski	 Disabling this option saves about 7K of kernel size and
11841ad83c85SAndy Lutomirski	 possibly 4K of additional runtime pagetable memory.
11851ad83c85SAndy Lutomirski
1186506f1d07SSam Ravnborgconfig TOSHIBA
1187506f1d07SSam Ravnborg	tristate "Toshiba Laptop support"
1188506f1d07SSam Ravnborg	depends on X86_32
1189506f1d07SSam Ravnborg	---help---
1190506f1d07SSam Ravnborg	  This adds a driver to safely access the System Management Mode of
1191506f1d07SSam Ravnborg	  the CPU on Toshiba portables with a genuine Toshiba BIOS. It does
1192506f1d07SSam Ravnborg	  not work on models with a Phoenix BIOS. The System Management Mode
1193506f1d07SSam Ravnborg	  is used to set the BIOS and power saving options on Toshiba portables.
1194506f1d07SSam Ravnborg
1195506f1d07SSam Ravnborg	  For information on utilities to make use of this driver see the
1196506f1d07SSam Ravnborg	  Toshiba Linux utilities web site at:
1197506f1d07SSam Ravnborg	  <http://www.buzzard.org.uk/toshiba/>.
1198506f1d07SSam Ravnborg
1199506f1d07SSam Ravnborg	  Say Y if you intend to run this kernel on a Toshiba portable.
1200506f1d07SSam Ravnborg	  Say N otherwise.
1201506f1d07SSam Ravnborg
1202506f1d07SSam Ravnborgconfig I8K
1203039ae585SPali Rohár	tristate "Dell i8k legacy laptop support"
1204949a9d70SJean Delvare	select HWMON
1205039ae585SPali Rohár	select SENSORS_DELL_SMM
1206506f1d07SSam Ravnborg	---help---
1207039ae585SPali Rohár	  This option enables legacy /proc/i8k userspace interface in hwmon
1208039ae585SPali Rohár	  dell-smm-hwmon driver. Character file /proc/i8k reports bios version,
1209039ae585SPali Rohár	  temperature and allows controlling fan speeds of Dell laptops via
1210039ae585SPali Rohár	  System Management Mode. For old Dell laptops (like Dell Inspiron 8000)
1211039ae585SPali Rohár	  it reports also power and hotkey status. For fan speed control is
1212039ae585SPali Rohár	  needed userspace package i8kutils.
1213506f1d07SSam Ravnborg
1214039ae585SPali Rohár	  Say Y if you intend to run this kernel on old Dell laptops or want to
1215039ae585SPali Rohár	  use userspace package i8kutils.
1216506f1d07SSam Ravnborg	  Say N otherwise.
1217506f1d07SSam Ravnborg
1218506f1d07SSam Ravnborgconfig X86_REBOOTFIXUPS
12199ba16087SJan Beulich	bool "Enable X86 board specific fixups for reboot"
12209ba16087SJan Beulich	depends on X86_32
1221506f1d07SSam Ravnborg	---help---
1222506f1d07SSam Ravnborg	  This enables chipset and/or board specific fixups to be done
1223506f1d07SSam Ravnborg	  in order to get reboot to work correctly. This is only needed on
1224506f1d07SSam Ravnborg	  some combinations of hardware and BIOS. The symptom, for which
1225506f1d07SSam Ravnborg	  this config is intended, is when reboot ends with a stalled/hung
1226506f1d07SSam Ravnborg	  system.
1227506f1d07SSam Ravnborg
1228506f1d07SSam Ravnborg	  Currently, the only fixup is for the Geode machines using
12295e3a77e9SFlorian Fainelli	  CS5530A and CS5536 chipsets and the RDC R-321x SoC.
1230506f1d07SSam Ravnborg
1231506f1d07SSam Ravnborg	  Say Y if you want to enable the fixup. Currently, it's safe to
1232506f1d07SSam Ravnborg	  enable this option even if you don't need it.
1233506f1d07SSam Ravnborg	  Say N otherwise.
1234506f1d07SSam Ravnborg
1235506f1d07SSam Ravnborgconfig MICROCODE
12369a2bc335SBorislav Petkov	bool "CPU microcode loading support"
12379a2bc335SBorislav Petkov	default y
123880030e3dSBorislav Petkov	depends on CPU_SUP_AMD || CPU_SUP_INTEL
1239506f1d07SSam Ravnborg	select FW_LOADER
1240506f1d07SSam Ravnborg	---help---
1241506f1d07SSam Ravnborg	  If you say Y here, you will be able to update the microcode on
12425f9c01aaSBorislav Petkov	  Intel and AMD processors. The Intel support is for the IA32 family,
12435f9c01aaSBorislav Petkov	  e.g. Pentium Pro, Pentium II, Pentium III, Pentium 4, Xeon etc. The
12445f9c01aaSBorislav Petkov	  AMD support is for families 0x10 and later. You will obviously need
12455f9c01aaSBorislav Petkov	  the actual microcode binary data itself which is not shipped with
12465f9c01aaSBorislav Petkov	  the Linux kernel.
1247506f1d07SSam Ravnborg
12485f9c01aaSBorislav Petkov	  The preferred method to load microcode from a detached initrd is described
12495f9c01aaSBorislav Petkov	  in Documentation/x86/early-microcode.txt. For that you need to enable
12505f9c01aaSBorislav Petkov	  CONFIG_BLK_DEV_INITRD in order for the loader to be able to scan the
12515f9c01aaSBorislav Petkov	  initrd for microcode blobs.
1252506f1d07SSam Ravnborg
12535f9c01aaSBorislav Petkov	  In addition, you can build-in the microcode into the kernel. For that you
12545f9c01aaSBorislav Petkov	  need to enable FIRMWARE_IN_KERNEL and add the vendor-supplied microcode
12555f9c01aaSBorislav Petkov	  to the CONFIG_EXTRA_FIRMWARE config option.
1256506f1d07SSam Ravnborg
12578d86f390SPeter Orubaconfig MICROCODE_INTEL
1258e43f6e67SBorislav Petkov	bool "Intel microcode loading support"
12598d86f390SPeter Oruba	depends on MICROCODE
12608d86f390SPeter Oruba	default MICROCODE
12618d86f390SPeter Oruba	select FW_LOADER
12628f9ca475SIngo Molnar	---help---
12638d86f390SPeter Oruba	  This options enables microcode patch loading support for Intel
12648d86f390SPeter Oruba	  processors.
12658d86f390SPeter Oruba
1266b8989db9SAlan	  For the current Intel microcode data package go to
1267b8989db9SAlan	  <https://downloadcenter.intel.com> and search for
1268b8989db9SAlan	  'Linux Processor Microcode Data File'.
12698d86f390SPeter Oruba
127080cc9f10SPeter Orubaconfig MICROCODE_AMD
1271e43f6e67SBorislav Petkov	bool "AMD microcode loading support"
127280cc9f10SPeter Oruba	depends on MICROCODE
127380cc9f10SPeter Oruba	select FW_LOADER
12748f9ca475SIngo Molnar	---help---
127580cc9f10SPeter Oruba	  If you select this option, microcode patch loading support for AMD
127680cc9f10SPeter Oruba	  processors will be enabled.
127780cc9f10SPeter Oruba
1278506f1d07SSam Ravnborgconfig MICROCODE_OLD_INTERFACE
12793c2362e6SHarvey Harrison	def_bool y
1280506f1d07SSam Ravnborg	depends on MICROCODE
1281506f1d07SSam Ravnborg
1282506f1d07SSam Ravnborgconfig X86_MSR
1283506f1d07SSam Ravnborg	tristate "/dev/cpu/*/msr - Model-specific register support"
12848f9ca475SIngo Molnar	---help---
1285506f1d07SSam Ravnborg	  This device gives privileged processes access to the x86
1286506f1d07SSam Ravnborg	  Model-Specific Registers (MSRs).  It is a character device with
1287506f1d07SSam Ravnborg	  major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr.
1288506f1d07SSam Ravnborg	  MSR accesses are directed to a specific CPU on multi-processor
1289506f1d07SSam Ravnborg	  systems.
1290506f1d07SSam Ravnborg
1291506f1d07SSam Ravnborgconfig X86_CPUID
1292506f1d07SSam Ravnborg	tristate "/dev/cpu/*/cpuid - CPU information support"
12938f9ca475SIngo Molnar	---help---
1294506f1d07SSam Ravnborg	  This device gives processes access to the x86 CPUID instruction to
1295506f1d07SSam Ravnborg	  be executed on a specific processor.  It is a character device
1296506f1d07SSam Ravnborg	  with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to
1297506f1d07SSam Ravnborg	  /dev/cpu/31/cpuid.
1298506f1d07SSam Ravnborg
1299506f1d07SSam Ravnborgchoice
1300506f1d07SSam Ravnborg	prompt "High Memory Support"
13016fc108a0SJan Beulich	default HIGHMEM4G
1302506f1d07SSam Ravnborg	depends on X86_32
1303506f1d07SSam Ravnborg
1304506f1d07SSam Ravnborgconfig NOHIGHMEM
1305506f1d07SSam Ravnborg	bool "off"
1306506f1d07SSam Ravnborg	---help---
1307506f1d07SSam Ravnborg	  Linux can use up to 64 Gigabytes of physical memory on x86 systems.
1308506f1d07SSam Ravnborg	  However, the address space of 32-bit x86 processors is only 4
1309506f1d07SSam Ravnborg	  Gigabytes large. That means that, if you have a large amount of
1310506f1d07SSam Ravnborg	  physical memory, not all of it can be "permanently mapped" by the
1311506f1d07SSam Ravnborg	  kernel. The physical memory that's not permanently mapped is called
1312506f1d07SSam Ravnborg	  "high memory".
1313506f1d07SSam Ravnborg
1314506f1d07SSam Ravnborg	  If you are compiling a kernel which will never run on a machine with
1315506f1d07SSam Ravnborg	  more than 1 Gigabyte total physical RAM, answer "off" here (default
1316506f1d07SSam Ravnborg	  choice and suitable for most users). This will result in a "3GB/1GB"
1317506f1d07SSam Ravnborg	  split: 3GB are mapped so that each process sees a 3GB virtual memory
1318506f1d07SSam Ravnborg	  space and the remaining part of the 4GB virtual memory space is used
1319506f1d07SSam Ravnborg	  by the kernel to permanently map as much physical memory as
1320506f1d07SSam Ravnborg	  possible.
1321506f1d07SSam Ravnborg
1322506f1d07SSam Ravnborg	  If the machine has between 1 and 4 Gigabytes physical RAM, then
1323506f1d07SSam Ravnborg	  answer "4GB" here.
1324506f1d07SSam Ravnborg
1325506f1d07SSam Ravnborg	  If more than 4 Gigabytes is used then answer "64GB" here. This
1326506f1d07SSam Ravnborg	  selection turns Intel PAE (Physical Address Extension) mode on.
1327506f1d07SSam Ravnborg	  PAE implements 3-level paging on IA32 processors. PAE is fully
1328506f1d07SSam Ravnborg	  supported by Linux, PAE mode is implemented on all recent Intel
1329506f1d07SSam Ravnborg	  processors (Pentium Pro and better). NOTE: If you say "64GB" here,
1330506f1d07SSam Ravnborg	  then the kernel will not boot on CPUs that don't support PAE!
1331506f1d07SSam Ravnborg
1332506f1d07SSam Ravnborg	  The actual amount of total physical memory will either be
1333506f1d07SSam Ravnborg	  auto detected or can be forced by using a kernel command line option
1334506f1d07SSam Ravnborg	  such as "mem=256M". (Try "man bootparam" or see the documentation of
1335506f1d07SSam Ravnborg	  your boot loader (lilo or loadlin) about how to pass options to the
1336506f1d07SSam Ravnborg	  kernel at boot time.)
1337506f1d07SSam Ravnborg
1338506f1d07SSam Ravnborg	  If unsure, say "off".
1339506f1d07SSam Ravnborg
1340506f1d07SSam Ravnborgconfig HIGHMEM4G
1341506f1d07SSam Ravnborg	bool "4GB"
13428f9ca475SIngo Molnar	---help---
1343506f1d07SSam Ravnborg	  Select this if you have a 32-bit processor and between 1 and 4
1344506f1d07SSam Ravnborg	  gigabytes of physical RAM.
1345506f1d07SSam Ravnborg
1346506f1d07SSam Ravnborgconfig HIGHMEM64G
1347506f1d07SSam Ravnborg	bool "64GB"
1348eb068e78SH. Peter Anvin	depends on !M486
1349506f1d07SSam Ravnborg	select X86_PAE
13508f9ca475SIngo Molnar	---help---
1351506f1d07SSam Ravnborg	  Select this if you have a 32-bit processor and more than 4
1352506f1d07SSam Ravnborg	  gigabytes of physical RAM.
1353506f1d07SSam Ravnborg
1354506f1d07SSam Ravnborgendchoice
1355506f1d07SSam Ravnborg
1356506f1d07SSam Ravnborgchoice
13576a108a14SDavid Rientjes	prompt "Memory split" if EXPERT
1358506f1d07SSam Ravnborg	default VMSPLIT_3G
1359506f1d07SSam Ravnborg	depends on X86_32
13608f9ca475SIngo Molnar	---help---
1361506f1d07SSam Ravnborg	  Select the desired split between kernel and user memory.
1362506f1d07SSam Ravnborg
1363506f1d07SSam Ravnborg	  If the address range available to the kernel is less than the
1364506f1d07SSam Ravnborg	  physical memory installed, the remaining memory will be available
1365506f1d07SSam Ravnborg	  as "high memory". Accessing high memory is a little more costly
1366506f1d07SSam Ravnborg	  than low memory, as it needs to be mapped into the kernel first.
1367506f1d07SSam Ravnborg	  Note that increasing the kernel address space limits the range
1368506f1d07SSam Ravnborg	  available to user programs, making the address space there
1369506f1d07SSam Ravnborg	  tighter.  Selecting anything other than the default 3G/1G split
1370506f1d07SSam Ravnborg	  will also likely make your kernel incompatible with binary-only
1371506f1d07SSam Ravnborg	  kernel modules.
1372506f1d07SSam Ravnborg
1373506f1d07SSam Ravnborg	  If you are not absolutely sure what you are doing, leave this
1374506f1d07SSam Ravnborg	  option alone!
1375506f1d07SSam Ravnborg
1376506f1d07SSam Ravnborg	config VMSPLIT_3G
1377506f1d07SSam Ravnborg		bool "3G/1G user/kernel split"
1378506f1d07SSam Ravnborg	config VMSPLIT_3G_OPT
1379506f1d07SSam Ravnborg		depends on !X86_PAE
1380506f1d07SSam Ravnborg		bool "3G/1G user/kernel split (for full 1G low memory)"
1381506f1d07SSam Ravnborg	config VMSPLIT_2G
1382506f1d07SSam Ravnborg		bool "2G/2G user/kernel split"
1383506f1d07SSam Ravnborg	config VMSPLIT_2G_OPT
1384506f1d07SSam Ravnborg		depends on !X86_PAE
1385506f1d07SSam Ravnborg		bool "2G/2G user/kernel split (for full 2G low memory)"
1386506f1d07SSam Ravnborg	config VMSPLIT_1G
1387506f1d07SSam Ravnborg		bool "1G/3G user/kernel split"
1388506f1d07SSam Ravnborgendchoice
1389506f1d07SSam Ravnborg
1390506f1d07SSam Ravnborgconfig PAGE_OFFSET
1391506f1d07SSam Ravnborg	hex
1392506f1d07SSam Ravnborg	default 0xB0000000 if VMSPLIT_3G_OPT
1393506f1d07SSam Ravnborg	default 0x80000000 if VMSPLIT_2G
1394506f1d07SSam Ravnborg	default 0x78000000 if VMSPLIT_2G_OPT
1395506f1d07SSam Ravnborg	default 0x40000000 if VMSPLIT_1G
1396506f1d07SSam Ravnborg	default 0xC0000000
1397506f1d07SSam Ravnborg	depends on X86_32
1398506f1d07SSam Ravnborg
1399506f1d07SSam Ravnborgconfig HIGHMEM
14003c2362e6SHarvey Harrison	def_bool y
1401506f1d07SSam Ravnborg	depends on X86_32 && (HIGHMEM64G || HIGHMEM4G)
1402506f1d07SSam Ravnborg
1403506f1d07SSam Ravnborgconfig X86_PAE
14049ba16087SJan Beulich	bool "PAE (Physical Address Extension) Support"
1405506f1d07SSam Ravnborg	depends on X86_32 && !HIGHMEM4G
14069d99c712SChristian Melki	select SWIOTLB
14078f9ca475SIngo Molnar	---help---
1408506f1d07SSam Ravnborg	  PAE is required for NX support, and furthermore enables
1409506f1d07SSam Ravnborg	  larger swapspace support for non-overcommit purposes. It
1410506f1d07SSam Ravnborg	  has the cost of more pagetable lookup overhead, and also
1411506f1d07SSam Ravnborg	  consumes more pagetable space per process.
1412506f1d07SSam Ravnborg
141377ef56e4SKirill A. Shutemovconfig X86_5LEVEL
141477ef56e4SKirill A. Shutemov	bool "Enable 5-level page tables support"
141577ef56e4SKirill A. Shutemov	depends on X86_64
141677ef56e4SKirill A. Shutemov	---help---
141777ef56e4SKirill A. Shutemov	  5-level paging enables access to larger address space:
141877ef56e4SKirill A. Shutemov	  upto 128 PiB of virtual address space and 4 PiB of
141977ef56e4SKirill A. Shutemov	  physical address space.
142077ef56e4SKirill A. Shutemov
142177ef56e4SKirill A. Shutemov	  It will be supported by future Intel CPUs.
142277ef56e4SKirill A. Shutemov
142377ef56e4SKirill A. Shutemov	  Note: a kernel with this option enabled can only be booted
142477ef56e4SKirill A. Shutemov	  on machines that support the feature.
142577ef56e4SKirill A. Shutemov
142677ef56e4SKirill A. Shutemov	  See Documentation/x86/x86_64/5level-paging.txt for more
142777ef56e4SKirill A. Shutemov	  information.
142877ef56e4SKirill A. Shutemov
142977ef56e4SKirill A. Shutemov	  Say N if unsure.
143077ef56e4SKirill A. Shutemov
1431600715dcSJeremy Fitzhardingeconfig ARCH_PHYS_ADDR_T_64BIT
14323120e25eSJan Beulich	def_bool y
14333120e25eSJan Beulich	depends on X86_64 || X86_PAE
1434600715dcSJeremy Fitzhardinge
143566f2b061SFUJITA Tomonoriconfig ARCH_DMA_ADDR_T_64BIT
14363120e25eSJan Beulich	def_bool y
14373120e25eSJan Beulich	depends on X86_64 || HIGHMEM64G
143866f2b061SFUJITA Tomonori
143910971ab2SIngo Molnarconfig X86_DIRECT_GBPAGES
1440e5008abeSLuis R. Rodriguez	def_bool y
14414675ff05SLevin, Alexander (Sasha Levin)	depends on X86_64 && !DEBUG_PAGEALLOC
14428f9ca475SIngo Molnar	---help---
144310971ab2SIngo Molnar	  Certain kernel features effectively disable kernel
144410971ab2SIngo Molnar	  linear 1 GB mappings (even if the CPU otherwise
144510971ab2SIngo Molnar	  supports them), so don't confuse the user by printing
144610971ab2SIngo Molnar	  that we have them enabled.
14479e899816SNick Piggin
14487744ccdbSTom Lendackyconfig ARCH_HAS_MEM_ENCRYPT
14497744ccdbSTom Lendacky	def_bool y
14507744ccdbSTom Lendacky
14517744ccdbSTom Lendackyconfig AMD_MEM_ENCRYPT
14527744ccdbSTom Lendacky	bool "AMD Secure Memory Encryption (SME) support"
14537744ccdbSTom Lendacky	depends on X86_64 && CPU_SUP_AMD
14547744ccdbSTom Lendacky	---help---
14557744ccdbSTom Lendacky	  Say yes to enable support for the encryption of system memory.
14567744ccdbSTom Lendacky	  This requires an AMD processor that supports Secure Memory
14577744ccdbSTom Lendacky	  Encryption (SME).
14587744ccdbSTom Lendacky
14597744ccdbSTom Lendackyconfig AMD_MEM_ENCRYPT_ACTIVE_BY_DEFAULT
14607744ccdbSTom Lendacky	bool "Activate AMD Secure Memory Encryption (SME) by default"
14617744ccdbSTom Lendacky	default y
14627744ccdbSTom Lendacky	depends on AMD_MEM_ENCRYPT
14637744ccdbSTom Lendacky	---help---
14647744ccdbSTom Lendacky	  Say yes to have system memory encrypted by default if running on
14657744ccdbSTom Lendacky	  an AMD processor that supports Secure Memory Encryption (SME).
14667744ccdbSTom Lendacky
14677744ccdbSTom Lendacky	  If set to Y, then the encryption of system memory can be
14687744ccdbSTom Lendacky	  deactivated with the mem_encrypt=off command line option.
14697744ccdbSTom Lendacky
14707744ccdbSTom Lendacky	  If set to N, then the encryption of system memory can be
14717744ccdbSTom Lendacky	  activated with the mem_encrypt=on command line option.
14727744ccdbSTom Lendacky
1473f88a68faSTom Lendackyconfig ARCH_USE_MEMREMAP_PROT
1474f88a68faSTom Lendacky	def_bool y
1475f88a68faSTom Lendacky	depends on AMD_MEM_ENCRYPT
1476f88a68faSTom Lendacky
1477506f1d07SSam Ravnborg# Common NUMA Features
1478506f1d07SSam Ravnborgconfig NUMA
1479fd51b2d7SKOSAKI Motohiro	bool "Numa Memory Allocation and Scheduler Support"
1480506f1d07SSam Ravnborg	depends on SMP
1481b5660ba7SH. Peter Anvin	depends on X86_64 || (X86_32 && HIGHMEM64G && X86_BIGSMP)
1482b5660ba7SH. Peter Anvin	default y if X86_BIGSMP
14838f9ca475SIngo Molnar	---help---
1484506f1d07SSam Ravnborg	  Enable NUMA (Non Uniform Memory Access) support.
1485fd51b2d7SKOSAKI Motohiro
1486506f1d07SSam Ravnborg	  The kernel will try to allocate memory used by a CPU on the
1487506f1d07SSam Ravnborg	  local memory controller of the CPU and add some more
1488506f1d07SSam Ravnborg	  NUMA awareness to the kernel.
1489506f1d07SSam Ravnborg
1490c280ea5eSIngo Molnar	  For 64-bit this is recommended if the system is Intel Core i7
1491fd51b2d7SKOSAKI Motohiro	  (or later), AMD Opteron, or EM64T NUMA.
1492fd51b2d7SKOSAKI Motohiro
1493b5660ba7SH. Peter Anvin	  For 32-bit this is only needed if you boot a 32-bit
14947cf6c945SDavid Rientjes	  kernel on a 64-bit NUMA platform.
1495fd51b2d7SKOSAKI Motohiro
1496fd51b2d7SKOSAKI Motohiro	  Otherwise, you should say N.
1497506f1d07SSam Ravnborg
1498eec1d4faSHans Rosenfeldconfig AMD_NUMA
14993c2362e6SHarvey Harrison	def_bool y
15003c2362e6SHarvey Harrison	prompt "Old style AMD Opteron NUMA detection"
15015da0ef9aSTejun Heo	depends on X86_64 && NUMA && PCI
15028f9ca475SIngo Molnar	---help---
1503eec1d4faSHans Rosenfeld	  Enable AMD NUMA node topology detection.  You should say Y here if
1504eec1d4faSHans Rosenfeld	  you have a multi processor AMD system. This uses an old method to
1505eec1d4faSHans Rosenfeld	  read the NUMA configuration directly from the builtin Northbridge
1506eec1d4faSHans Rosenfeld	  of Opteron. It is recommended to use X86_64_ACPI_NUMA instead,
1507eec1d4faSHans Rosenfeld	  which also takes priority if both are compiled in.
1508506f1d07SSam Ravnborg
1509506f1d07SSam Ravnborgconfig X86_64_ACPI_NUMA
15103c2362e6SHarvey Harrison	def_bool y
15113c2362e6SHarvey Harrison	prompt "ACPI NUMA detection"
1512506f1d07SSam Ravnborg	depends on X86_64 && NUMA && ACPI && PCI
1513506f1d07SSam Ravnborg	select ACPI_NUMA
15148f9ca475SIngo Molnar	---help---
1515506f1d07SSam Ravnborg	  Enable ACPI SRAT based node topology detection.
1516506f1d07SSam Ravnborg
15176ec6e0d9SSuresh Siddha# Some NUMA nodes have memory ranges that span
15186ec6e0d9SSuresh Siddha# other nodes.  Even though a pfn is valid and
15196ec6e0d9SSuresh Siddha# between a node's start and end pfns, it may not
15206ec6e0d9SSuresh Siddha# reside on that node.  See memmap_init_zone()
15216ec6e0d9SSuresh Siddha# for details.
15226ec6e0d9SSuresh Siddhaconfig NODES_SPAN_OTHER_NODES
15236ec6e0d9SSuresh Siddha	def_bool y
15246ec6e0d9SSuresh Siddha	depends on X86_64_ACPI_NUMA
15256ec6e0d9SSuresh Siddha
1526506f1d07SSam Ravnborgconfig NUMA_EMU
1527506f1d07SSam Ravnborg	bool "NUMA emulation"
15281b7e03efSTejun Heo	depends on NUMA
15298f9ca475SIngo Molnar	---help---
1530506f1d07SSam Ravnborg	  Enable NUMA emulation. A flat machine will be split
1531506f1d07SSam Ravnborg	  into virtual nodes when booted with "numa=fake=N", where N is the
1532506f1d07SSam Ravnborg	  number of nodes. This is only useful for debugging.
1533506f1d07SSam Ravnborg
1534506f1d07SSam Ravnborgconfig NODES_SHIFT
1535d25e26b6SLinus Torvalds	int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP
153651591e31SDavid Rientjes	range 1 10
153751591e31SDavid Rientjes	default "10" if MAXSMP
1538506f1d07SSam Ravnborg	default "6" if X86_64
1539506f1d07SSam Ravnborg	default "3"
1540506f1d07SSam Ravnborg	depends on NEED_MULTIPLE_NODES
15418f9ca475SIngo Molnar	---help---
15421184dc2fSMike Travis	  Specify the maximum number of NUMA Nodes available on the target
1543692105b8SMatt LaPlante	  system.  Increases memory reserved to accommodate various tables.
1544506f1d07SSam Ravnborg
1545506f1d07SSam Ravnborgconfig ARCH_HAVE_MEMORY_PRESENT
15463c2362e6SHarvey Harrison	def_bool y
1547506f1d07SSam Ravnborg	depends on X86_32 && DISCONTIGMEM
1548506f1d07SSam Ravnborg
1549506f1d07SSam Ravnborgconfig NEED_NODE_MEMMAP_SIZE
15503c2362e6SHarvey Harrison	def_bool y
1551506f1d07SSam Ravnborg	depends on X86_32 && (DISCONTIGMEM || SPARSEMEM)
1552506f1d07SSam Ravnborg
1553506f1d07SSam Ravnborgconfig ARCH_FLATMEM_ENABLE
1554506f1d07SSam Ravnborg	def_bool y
15553b16651fSTejun Heo	depends on X86_32 && !NUMA
1556506f1d07SSam Ravnborg
1557506f1d07SSam Ravnborgconfig ARCH_DISCONTIGMEM_ENABLE
1558506f1d07SSam Ravnborg	def_bool y
1559b263295dSChristoph Lameter	depends on NUMA && X86_32
1560506f1d07SSam Ravnborg
1561506f1d07SSam Ravnborgconfig ARCH_DISCONTIGMEM_DEFAULT
1562506f1d07SSam Ravnborg	def_bool y
1563b263295dSChristoph Lameter	depends on NUMA && X86_32
1564b263295dSChristoph Lameter
1565506f1d07SSam Ravnborgconfig ARCH_SPARSEMEM_ENABLE
1566506f1d07SSam Ravnborg	def_bool y
15676ea30386SKees Cook	depends on X86_64 || NUMA || X86_32 || X86_32_NON_STANDARD
1568506f1d07SSam Ravnborg	select SPARSEMEM_STATIC if X86_32
1569506f1d07SSam Ravnborg	select SPARSEMEM_VMEMMAP_ENABLE if X86_64
1570506f1d07SSam Ravnborg
15713b16651fSTejun Heoconfig ARCH_SPARSEMEM_DEFAULT
15723b16651fSTejun Heo	def_bool y
15733b16651fSTejun Heo	depends on X86_64
15743b16651fSTejun Heo
1575506f1d07SSam Ravnborgconfig ARCH_SELECT_MEMORY_MODEL
1576506f1d07SSam Ravnborg	def_bool y
1577b263295dSChristoph Lameter	depends on ARCH_SPARSEMEM_ENABLE
1578506f1d07SSam Ravnborg
1579506f1d07SSam Ravnborgconfig ARCH_MEMORY_PROBE
1580a0842b70SToshi Kani	bool "Enable sysfs memory/probe interface"
15813120e25eSJan Beulich	depends on X86_64 && MEMORY_HOTPLUG
1582a0842b70SToshi Kani	help
1583a0842b70SToshi Kani	  This option enables a sysfs memory/probe interface for testing.
1584a0842b70SToshi Kani	  See Documentation/memory-hotplug.txt for more information.
1585a0842b70SToshi Kani	  If you are unsure how to answer this question, answer N.
1586506f1d07SSam Ravnborg
15873b16651fSTejun Heoconfig ARCH_PROC_KCORE_TEXT
15883b16651fSTejun Heo	def_bool y
15893b16651fSTejun Heo	depends on X86_64 && PROC_KCORE
15903b16651fSTejun Heo
1591a29815a3SAvi Kivityconfig ILLEGAL_POINTER_VALUE
1592a29815a3SAvi Kivity       hex
1593a29815a3SAvi Kivity       default 0 if X86_32
1594a29815a3SAvi Kivity       default 0xdead000000000000 if X86_64
1595a29815a3SAvi Kivity
1596506f1d07SSam Ravnborgsource "mm/Kconfig"
1597506f1d07SSam Ravnborg
15987a67832cSDan Williamsconfig X86_PMEM_LEGACY_DEVICE
15997a67832cSDan Williams	bool
16007a67832cSDan Williams
1601ec776ef6SChristoph Hellwigconfig X86_PMEM_LEGACY
16027a67832cSDan Williams	tristate "Support non-standard NVDIMMs and ADR protected memory"
16039f53f9faSDan Williams	depends on PHYS_ADDR_T_64BIT
16049f53f9faSDan Williams	depends on BLK_DEV
16057a67832cSDan Williams	select X86_PMEM_LEGACY_DEVICE
16069f53f9faSDan Williams	select LIBNVDIMM
1607ec776ef6SChristoph Hellwig	help
1608ec776ef6SChristoph Hellwig	  Treat memory marked using the non-standard e820 type of 12 as used
1609ec776ef6SChristoph Hellwig	  by the Intel Sandy Bridge-EP reference BIOS as protected memory.
1610ec776ef6SChristoph Hellwig	  The kernel will offer these regions to the 'pmem' driver so
1611ec776ef6SChristoph Hellwig	  they can be used for persistent storage.
1612ec776ef6SChristoph Hellwig
1613ec776ef6SChristoph Hellwig	  Say Y if unsure.
1614ec776ef6SChristoph Hellwig
1615506f1d07SSam Ravnborgconfig HIGHPTE
1616506f1d07SSam Ravnborg	bool "Allocate 3rd-level pagetables from highmem"
16176fc108a0SJan Beulich	depends on HIGHMEM
16188f9ca475SIngo Molnar	---help---
1619506f1d07SSam Ravnborg	  The VM uses one page table entry for each page of physical memory.
1620506f1d07SSam Ravnborg	  For systems with a lot of RAM, this can be wasteful of precious
1621506f1d07SSam Ravnborg	  low memory.  Setting this option will put user-space page table
1622506f1d07SSam Ravnborg	  entries in high memory.
1623506f1d07SSam Ravnborg
16249f077871SJeremy Fitzhardingeconfig X86_CHECK_BIOS_CORRUPTION
16259f077871SJeremy Fitzhardinge	bool "Check for low memory corruption"
16268f9ca475SIngo Molnar	---help---
16279f077871SJeremy Fitzhardinge	  Periodically check for memory corruption in low memory, which
16289f077871SJeremy Fitzhardinge	  is suspected to be caused by BIOS.  Even when enabled in the
16299f077871SJeremy Fitzhardinge	  configuration, it is disabled at runtime.  Enable it by
16309f077871SJeremy Fitzhardinge	  setting "memory_corruption_check=1" on the kernel command
16319f077871SJeremy Fitzhardinge	  line.  By default it scans the low 64k of memory every 60
16329f077871SJeremy Fitzhardinge	  seconds; see the memory_corruption_check_size and
16339f077871SJeremy Fitzhardinge	  memory_corruption_check_period parameters in
16348c27ceffSMauro Carvalho Chehab	  Documentation/admin-guide/kernel-parameters.rst to adjust this.
16359f077871SJeremy Fitzhardinge
16369f077871SJeremy Fitzhardinge	  When enabled with the default parameters, this option has
16379f077871SJeremy Fitzhardinge	  almost no overhead, as it reserves a relatively small amount
16389f077871SJeremy Fitzhardinge	  of memory and scans it infrequently.  It both detects corruption
16399f077871SJeremy Fitzhardinge	  and prevents it from affecting the running system.
16409f077871SJeremy Fitzhardinge
16419f077871SJeremy Fitzhardinge	  It is, however, intended as a diagnostic tool; if repeatable
16429f077871SJeremy Fitzhardinge	  BIOS-originated corruption always affects the same memory,
16439f077871SJeremy Fitzhardinge	  you can use memmap= to prevent the kernel from using that
16449f077871SJeremy Fitzhardinge	  memory.
16459f077871SJeremy Fitzhardinge
1646c885df50SJeremy Fitzhardingeconfig X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK
1647c885df50SJeremy Fitzhardinge	bool "Set the default setting of memory_corruption_check"
1648c885df50SJeremy Fitzhardinge	depends on X86_CHECK_BIOS_CORRUPTION
1649c885df50SJeremy Fitzhardinge	default y
16508f9ca475SIngo Molnar	---help---
1651c885df50SJeremy Fitzhardinge	  Set whether the default state of memory_corruption_check is
1652c885df50SJeremy Fitzhardinge	  on or off.
1653c885df50SJeremy Fitzhardinge
16549ea77bdbSH. Peter Anvinconfig X86_RESERVE_LOW
1655d0cd7425SH. Peter Anvin	int "Amount of low memory, in kilobytes, to reserve for the BIOS"
1656d0cd7425SH. Peter Anvin	default 64
1657d0cd7425SH. Peter Anvin	range 4 640
16588f9ca475SIngo Molnar	---help---
1659d0cd7425SH. Peter Anvin	  Specify the amount of low memory to reserve for the BIOS.
1660fc381519SIngo Molnar
1661d0cd7425SH. Peter Anvin	  The first page contains BIOS data structures that the kernel
1662d0cd7425SH. Peter Anvin	  must not use, so that page must always be reserved.
1663fc381519SIngo Molnar
1664d0cd7425SH. Peter Anvin	  By default we reserve the first 64K of physical RAM, as a
1665d0cd7425SH. Peter Anvin	  number of BIOSes are known to corrupt that memory range
1666d0cd7425SH. Peter Anvin	  during events such as suspend/resume or monitor cable
1667d0cd7425SH. Peter Anvin	  insertion, so it must not be used by the kernel.
1668fc381519SIngo Molnar
1669d0cd7425SH. Peter Anvin	  You can set this to 4 if you are absolutely sure that you
1670d0cd7425SH. Peter Anvin	  trust the BIOS to get all its memory reservations and usages
1671d0cd7425SH. Peter Anvin	  right.  If you know your BIOS have problems beyond the
1672d0cd7425SH. Peter Anvin	  default 64K area, you can set this to 640 to avoid using the
1673d0cd7425SH. Peter Anvin	  entire low memory range.
1674d0cd7425SH. Peter Anvin
1675d0cd7425SH. Peter Anvin	  If you have doubts about the BIOS (e.g. suspend/resume does
1676d0cd7425SH. Peter Anvin	  not work or there's kernel crashes after certain hardware
1677d0cd7425SH. Peter Anvin	  hotplug events) then you might want to enable
1678d0cd7425SH. Peter Anvin	  X86_CHECK_BIOS_CORRUPTION=y to allow the kernel to check
1679d0cd7425SH. Peter Anvin	  typical corruption patterns.
1680d0cd7425SH. Peter Anvin
1681d0cd7425SH. Peter Anvin	  Leave this to the default value of 64 if you are unsure.
1682fc381519SIngo Molnar
1683506f1d07SSam Ravnborgconfig MATH_EMULATION
1684506f1d07SSam Ravnborg	bool
1685a5b9e5a2SAndy Lutomirski	depends on MODIFY_LDT_SYSCALL
1686506f1d07SSam Ravnborg	prompt "Math emulation" if X86_32
1687506f1d07SSam Ravnborg	---help---
1688506f1d07SSam Ravnborg	  Linux can emulate a math coprocessor (used for floating point
1689506f1d07SSam Ravnborg	  operations) if you don't have one. 486DX and Pentium processors have
1690506f1d07SSam Ravnborg	  a math coprocessor built in, 486SX and 386 do not, unless you added
1691506f1d07SSam Ravnborg	  a 487DX or 387, respectively. (The messages during boot time can
1692506f1d07SSam Ravnborg	  give you some hints here ["man dmesg"].) Everyone needs either a
1693506f1d07SSam Ravnborg	  coprocessor or this emulation.
1694506f1d07SSam Ravnborg
1695506f1d07SSam Ravnborg	  If you don't have a math coprocessor, you need to say Y here; if you
1696506f1d07SSam Ravnborg	  say Y here even though you have a coprocessor, the coprocessor will
1697506f1d07SSam Ravnborg	  be used nevertheless. (This behavior can be changed with the kernel
1698506f1d07SSam Ravnborg	  command line option "no387", which comes handy if your coprocessor
1699506f1d07SSam Ravnborg	  is broken. Try "man bootparam" or see the documentation of your boot
1700506f1d07SSam Ravnborg	  loader (lilo or loadlin) about how to pass options to the kernel at
1701506f1d07SSam Ravnborg	  boot time.) This means that it is a good idea to say Y here if you
1702506f1d07SSam Ravnborg	  intend to use this kernel on different machines.
1703506f1d07SSam Ravnborg
1704506f1d07SSam Ravnborg	  More information about the internals of the Linux math coprocessor
1705506f1d07SSam Ravnborg	  emulation can be found in <file:arch/x86/math-emu/README>.
1706506f1d07SSam Ravnborg
1707506f1d07SSam Ravnborg	  If you are not sure, say Y; apart from resulting in a 66 KB bigger
1708506f1d07SSam Ravnborg	  kernel, it won't hurt.
1709506f1d07SSam Ravnborg
1710506f1d07SSam Ravnborgconfig MTRR
17116fc108a0SJan Beulich	def_bool y
17126a108a14SDavid Rientjes	prompt "MTRR (Memory Type Range Register) support" if EXPERT
1713506f1d07SSam Ravnborg	---help---
1714506f1d07SSam Ravnborg	  On Intel P6 family processors (Pentium Pro, Pentium II and later)
1715506f1d07SSam Ravnborg	  the Memory Type Range Registers (MTRRs) may be used to control
1716506f1d07SSam Ravnborg	  processor access to memory ranges. This is most useful if you have
1717506f1d07SSam Ravnborg	  a video (VGA) card on a PCI or AGP bus. Enabling write-combining
1718506f1d07SSam Ravnborg	  allows bus write transfers to be combined into a larger transfer
1719506f1d07SSam Ravnborg	  before bursting over the PCI/AGP bus. This can increase performance
1720506f1d07SSam Ravnborg	  of image write operations 2.5 times or more. Saying Y here creates a
1721506f1d07SSam Ravnborg	  /proc/mtrr file which may be used to manipulate your processor's
1722506f1d07SSam Ravnborg	  MTRRs. Typically the X server should use this.
1723506f1d07SSam Ravnborg
1724506f1d07SSam Ravnborg	  This code has a reasonably generic interface so that similar
1725506f1d07SSam Ravnborg	  control registers on other processors can be easily supported
1726506f1d07SSam Ravnborg	  as well:
1727506f1d07SSam Ravnborg
1728506f1d07SSam Ravnborg	  The Cyrix 6x86, 6x86MX and M II processors have Address Range
1729506f1d07SSam Ravnborg	  Registers (ARRs) which provide a similar functionality to MTRRs. For
1730506f1d07SSam Ravnborg	  these, the ARRs are used to emulate the MTRRs.
1731506f1d07SSam Ravnborg	  The AMD K6-2 (stepping 8 and above) and K6-3 processors have two
1732506f1d07SSam Ravnborg	  MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing
1733506f1d07SSam Ravnborg	  write-combining. All of these processors are supported by this code
1734506f1d07SSam Ravnborg	  and it makes sense to say Y here if you have one of them.
1735506f1d07SSam Ravnborg
1736506f1d07SSam Ravnborg	  Saying Y here also fixes a problem with buggy SMP BIOSes which only
1737506f1d07SSam Ravnborg	  set the MTRRs for the boot CPU and not for the secondary CPUs. This
1738506f1d07SSam Ravnborg	  can lead to all sorts of problems, so it's good to say Y here.
1739506f1d07SSam Ravnborg
1740506f1d07SSam Ravnborg	  You can safely say Y even if your machine doesn't have MTRRs, you'll
1741506f1d07SSam Ravnborg	  just add about 9 KB to your kernel.
1742506f1d07SSam Ravnborg
17437225e751SRandy Dunlap	  See <file:Documentation/x86/mtrr.txt> for more information.
1744506f1d07SSam Ravnborg
174595ffa243SYinghai Luconfig MTRR_SANITIZER
17462ffb3501SYinghai Lu	def_bool y
174795ffa243SYinghai Lu	prompt "MTRR cleanup support"
174895ffa243SYinghai Lu	depends on MTRR
17498f9ca475SIngo Molnar	---help---
1750aba3728cSThomas Gleixner	  Convert MTRR layout from continuous to discrete, so X drivers can
1751aba3728cSThomas Gleixner	  add writeback entries.
175295ffa243SYinghai Lu
1753aba3728cSThomas Gleixner	  Can be disabled with disable_mtrr_cleanup on the kernel command line.
1754692105b8SMatt LaPlante	  The largest mtrr entry size for a continuous block can be set with
1755aba3728cSThomas Gleixner	  mtrr_chunk_size.
175695ffa243SYinghai Lu
17572ffb3501SYinghai Lu	  If unsure, say Y.
175895ffa243SYinghai Lu
175995ffa243SYinghai Luconfig MTRR_SANITIZER_ENABLE_DEFAULT
1760f5098d62SYinghai Lu	int "MTRR cleanup enable value (0-1)"
1761f5098d62SYinghai Lu	range 0 1
1762f5098d62SYinghai Lu	default "0"
176395ffa243SYinghai Lu	depends on MTRR_SANITIZER
17648f9ca475SIngo Molnar	---help---
1765f5098d62SYinghai Lu	  Enable mtrr cleanup default value
176695ffa243SYinghai Lu
176712031a62SYinghai Luconfig MTRR_SANITIZER_SPARE_REG_NR_DEFAULT
176812031a62SYinghai Lu	int "MTRR cleanup spare reg num (0-7)"
176912031a62SYinghai Lu	range 0 7
177012031a62SYinghai Lu	default "1"
177112031a62SYinghai Lu	depends on MTRR_SANITIZER
17728f9ca475SIngo Molnar	---help---
177312031a62SYinghai Lu	  mtrr cleanup spare entries default, it can be changed via
1774aba3728cSThomas Gleixner	  mtrr_spare_reg_nr=N on the kernel command line.
177512031a62SYinghai Lu
17762e5d9c85Svenkatesh.pallipadi@intel.comconfig X86_PAT
17776fc108a0SJan Beulich	def_bool y
17786a108a14SDavid Rientjes	prompt "x86 PAT support" if EXPERT
17792a8a2719SIngo Molnar	depends on MTRR
17808f9ca475SIngo Molnar	---help---
17812e5d9c85Svenkatesh.pallipadi@intel.com	  Use PAT attributes to setup page level cache control.
1782042b78e4SVenki Pallipadi
17832e5d9c85Svenkatesh.pallipadi@intel.com	  PATs are the modern equivalents of MTRRs and are much more
17842e5d9c85Svenkatesh.pallipadi@intel.com	  flexible than MTRRs.
17852e5d9c85Svenkatesh.pallipadi@intel.com
17862e5d9c85Svenkatesh.pallipadi@intel.com	  Say N here if you see bootup problems (boot crash, boot hang,
1787042b78e4SVenki Pallipadi	  spontaneous reboots) or a non-working video driver.
17882e5d9c85Svenkatesh.pallipadi@intel.com
17892e5d9c85Svenkatesh.pallipadi@intel.com	  If unsure, say Y.
17902e5d9c85Svenkatesh.pallipadi@intel.com
179146cf98cdSVenkatesh Pallipadiconfig ARCH_USES_PG_UNCACHED
179246cf98cdSVenkatesh Pallipadi	def_bool y
179346cf98cdSVenkatesh Pallipadi	depends on X86_PAT
179446cf98cdSVenkatesh Pallipadi
1795628c6246SH. Peter Anvinconfig ARCH_RANDOM
1796628c6246SH. Peter Anvin	def_bool y
1797628c6246SH. Peter Anvin	prompt "x86 architectural random number generator" if EXPERT
1798628c6246SH. Peter Anvin	---help---
1799628c6246SH. Peter Anvin	  Enable the x86 architectural RDRAND instruction
1800628c6246SH. Peter Anvin	  (Intel Bull Mountain technology) to generate random numbers.
1801628c6246SH. Peter Anvin	  If supported, this is a high bandwidth, cryptographically
1802628c6246SH. Peter Anvin	  secure hardware random number generator.
1803628c6246SH. Peter Anvin
180451ae4a2dSH. Peter Anvinconfig X86_SMAP
180551ae4a2dSH. Peter Anvin	def_bool y
180651ae4a2dSH. Peter Anvin	prompt "Supervisor Mode Access Prevention" if EXPERT
180751ae4a2dSH. Peter Anvin	---help---
180851ae4a2dSH. Peter Anvin	  Supervisor Mode Access Prevention (SMAP) is a security
180951ae4a2dSH. Peter Anvin	  feature in newer Intel processors.  There is a small
181051ae4a2dSH. Peter Anvin	  performance cost if this enabled and turned on; there is
181151ae4a2dSH. Peter Anvin	  also a small increase in the kernel size if this is enabled.
181251ae4a2dSH. Peter Anvin
181351ae4a2dSH. Peter Anvin	  If unsure, say Y.
181451ae4a2dSH. Peter Anvin
1815aa35f896SRicardo Nericonfig X86_INTEL_UMIP
1816796ebc81SRicardo Neri	def_bool y
1817aa35f896SRicardo Neri	depends on CPU_SUP_INTEL
1818aa35f896SRicardo Neri	prompt "Intel User Mode Instruction Prevention" if EXPERT
1819aa35f896SRicardo Neri	---help---
1820aa35f896SRicardo Neri	  The User Mode Instruction Prevention (UMIP) is a security
1821aa35f896SRicardo Neri	  feature in newer Intel processors. If enabled, a general
1822796ebc81SRicardo Neri	  protection fault is issued if the SGDT, SLDT, SIDT, SMSW
1823796ebc81SRicardo Neri	  or STR instructions are executed in user mode. These instructions
1824796ebc81SRicardo Neri	  unnecessarily expose information about the hardware state.
1825796ebc81SRicardo Neri
1826796ebc81SRicardo Neri	  The vast majority of applications do not use these instructions.
1827796ebc81SRicardo Neri	  For the very few that do, software emulation is provided in
1828796ebc81SRicardo Neri	  specific cases in protected and virtual-8086 modes. Emulated
1829796ebc81SRicardo Neri	  results are dummy.
1830aa35f896SRicardo Neri
183172e9b5feSDave Hansenconfig X86_INTEL_MPX
183272e9b5feSDave Hansen	prompt "Intel MPX (Memory Protection Extensions)"
183372e9b5feSDave Hansen	def_bool n
1834df3735c5SRik van Riel	# Note: only available in 64-bit mode due to VMA flags shortage
1835df3735c5SRik van Riel	depends on CPU_SUP_INTEL && X86_64
1836df3735c5SRik van Riel	select ARCH_USES_HIGH_VMA_FLAGS
183772e9b5feSDave Hansen	---help---
183872e9b5feSDave Hansen	  MPX provides hardware features that can be used in
183972e9b5feSDave Hansen	  conjunction with compiler-instrumented code to check
184072e9b5feSDave Hansen	  memory references.  It is designed to detect buffer
184172e9b5feSDave Hansen	  overflow or underflow bugs.
184272e9b5feSDave Hansen
184372e9b5feSDave Hansen	  This option enables running applications which are
184472e9b5feSDave Hansen	  instrumented or otherwise use MPX.  It does not use MPX
184572e9b5feSDave Hansen	  itself inside the kernel or to protect the kernel
184672e9b5feSDave Hansen	  against bad memory references.
184772e9b5feSDave Hansen
184872e9b5feSDave Hansen	  Enabling this option will make the kernel larger:
184972e9b5feSDave Hansen	  ~8k of kernel text and 36 bytes of data on a 64-bit
185072e9b5feSDave Hansen	  defconfig.  It adds a long to the 'mm_struct' which
185172e9b5feSDave Hansen	  will increase the kernel memory overhead of each
185272e9b5feSDave Hansen	  process and adds some branches to paths used during
185372e9b5feSDave Hansen	  exec() and munmap().
185472e9b5feSDave Hansen
185572e9b5feSDave Hansen	  For details, see Documentation/x86/intel_mpx.txt
185672e9b5feSDave Hansen
185772e9b5feSDave Hansen	  If unsure, say N.
185872e9b5feSDave Hansen
185935e97790SDave Hansenconfig X86_INTEL_MEMORY_PROTECTION_KEYS
1860284244a9SDave Hansen	prompt "Intel Memory Protection Keys"
186135e97790SDave Hansen	def_bool y
1862284244a9SDave Hansen	# Note: only available in 64-bit mode
186335e97790SDave Hansen	depends on CPU_SUP_INTEL && X86_64
186452c8e601SIngo Molnar	select ARCH_USES_HIGH_VMA_FLAGS
186552c8e601SIngo Molnar	select ARCH_HAS_PKEYS
1866284244a9SDave Hansen	---help---
1867284244a9SDave Hansen	  Memory Protection Keys provides a mechanism for enforcing
1868284244a9SDave Hansen	  page-based protections, but without requiring modification of the
1869284244a9SDave Hansen	  page tables when an application changes protection domains.
1870284244a9SDave Hansen
1871284244a9SDave Hansen	  For details, see Documentation/x86/protection-keys.txt
1872284244a9SDave Hansen
1873284244a9SDave Hansen	  If unsure, say y.
187435e97790SDave Hansen
1875506f1d07SSam Ravnborgconfig EFI
18769ba16087SJan Beulich	bool "EFI runtime service support"
18775b83683fSHuang, Ying	depends on ACPI
1878f6ce5002SSergey Vlasov	select UCS2_STRING
1879022ee6c5SArd Biesheuvel	select EFI_RUNTIME_WRAPPERS
1880506f1d07SSam Ravnborg	---help---
18818b2cb7a8SHuang, Ying	  This enables the kernel to use EFI runtime services that are
1882506f1d07SSam Ravnborg	  available (such as the EFI variable services).
1883506f1d07SSam Ravnborg
18848b2cb7a8SHuang, Ying	  This option is only useful on systems that have EFI firmware.
18858b2cb7a8SHuang, Ying	  In addition, you should use the latest ELILO loader available
18868b2cb7a8SHuang, Ying	  at <http://elilo.sourceforge.net> in order to take advantage
18878b2cb7a8SHuang, Ying	  of EFI runtime services. However, even with this option, the
18888b2cb7a8SHuang, Ying	  resultant kernel should continue to boot on existing non-EFI
18898b2cb7a8SHuang, Ying	  platforms.
1890506f1d07SSam Ravnborg
1891291f3632SMatt Flemingconfig EFI_STUB
1892291f3632SMatt Fleming       bool "EFI stub support"
1893b16d8c23SMatt Fleming       depends on EFI && !X86_USE_3DNOW
18947b2a583aSMatt Fleming       select RELOCATABLE
1895291f3632SMatt Fleming       ---help---
1896291f3632SMatt Fleming          This kernel feature allows a bzImage to be loaded directly
1897291f3632SMatt Fleming	  by EFI firmware without the use of a bootloader.
1898291f3632SMatt Fleming
18994172fe2fSRoy Franz	  See Documentation/efi-stub.txt for more information.
19000c759662SMatt Fleming
19017d453eeeSMatt Flemingconfig EFI_MIXED
19027d453eeeSMatt Fleming	bool "EFI mixed-mode support"
19037d453eeeSMatt Fleming	depends on EFI_STUB && X86_64
19047d453eeeSMatt Fleming	---help---
19057d453eeeSMatt Fleming	   Enabling this feature allows a 64-bit kernel to be booted
19067d453eeeSMatt Fleming	   on a 32-bit firmware, provided that your CPU supports 64-bit
19077d453eeeSMatt Fleming	   mode.
19087d453eeeSMatt Fleming
19097d453eeeSMatt Fleming	   Note that it is not possible to boot a mixed-mode enabled
19107d453eeeSMatt Fleming	   kernel via the EFI boot stub - a bootloader that supports
19117d453eeeSMatt Fleming	   the EFI handover protocol must be used.
19127d453eeeSMatt Fleming
19137d453eeeSMatt Fleming	   If unsure, say N.
19147d453eeeSMatt Fleming
1915506f1d07SSam Ravnborgconfig SECCOMP
19163c2362e6SHarvey Harrison	def_bool y
19173c2362e6SHarvey Harrison	prompt "Enable seccomp to safely compute untrusted bytecode"
19188f9ca475SIngo Molnar	---help---
1919506f1d07SSam Ravnborg	  This kernel feature is useful for number crunching applications
1920506f1d07SSam Ravnborg	  that may need to compute untrusted bytecode during their
1921506f1d07SSam Ravnborg	  execution. By using pipes or other transports made available to
1922506f1d07SSam Ravnborg	  the process as file descriptors supporting the read/write
1923506f1d07SSam Ravnborg	  syscalls, it's possible to isolate those applications in
1924506f1d07SSam Ravnborg	  their own address space using seccomp. Once seccomp is
19259c0bbee8SAlexey Dobriyan	  enabled via prctl(PR_SET_SECCOMP), it cannot be disabled
1926506f1d07SSam Ravnborg	  and the task is only allowed to execute a few safe syscalls
1927506f1d07SSam Ravnborg	  defined by each seccomp mode.
1928506f1d07SSam Ravnborg
1929506f1d07SSam Ravnborg	  If unsure, say Y. Only embedded should say N here.
1930506f1d07SSam Ravnborg
1931506f1d07SSam Ravnborgsource kernel/Kconfig.hz
1932506f1d07SSam Ravnborg
1933506f1d07SSam Ravnborgconfig KEXEC
1934506f1d07SSam Ravnborg	bool "kexec system call"
19352965faa5SDave Young	select KEXEC_CORE
19368f9ca475SIngo Molnar	---help---
1937506f1d07SSam Ravnborg	  kexec is a system call that implements the ability to shutdown your
1938506f1d07SSam Ravnborg	  current kernel, and to start another kernel.  It is like a reboot
1939506f1d07SSam Ravnborg	  but it is independent of the system firmware.   And like a reboot
1940506f1d07SSam Ravnborg	  you can start any kernel with it, not just Linux.
1941506f1d07SSam Ravnborg
1942506f1d07SSam Ravnborg	  The name comes from the similarity to the exec system call.
1943506f1d07SSam Ravnborg
1944506f1d07SSam Ravnborg	  It is an ongoing process to be certain the hardware in a machine
1945506f1d07SSam Ravnborg	  is properly shutdown, so do not be surprised if this code does not
1946bf220695SGeert Uytterhoeven	  initially work for you.  As of this writing the exact hardware
1947bf220695SGeert Uytterhoeven	  interface is strongly in flux, so no good recommendation can be
1948bf220695SGeert Uytterhoeven	  made.
1949506f1d07SSam Ravnborg
195074ca317cSVivek Goyalconfig KEXEC_FILE
195174ca317cSVivek Goyal	bool "kexec file based system call"
19522965faa5SDave Young	select KEXEC_CORE
195374ca317cSVivek Goyal	select BUILD_BIN2C
195474ca317cSVivek Goyal	depends on X86_64
195574ca317cSVivek Goyal	depends on CRYPTO=y
195674ca317cSVivek Goyal	depends on CRYPTO_SHA256=y
195774ca317cSVivek Goyal	---help---
195874ca317cSVivek Goyal	  This is new version of kexec system call. This system call is
195974ca317cSVivek Goyal	  file based and takes file descriptors as system call argument
196074ca317cSVivek Goyal	  for kernel and initramfs as opposed to list of segments as
196174ca317cSVivek Goyal	  accepted by previous system call.
196274ca317cSVivek Goyal
19638e7d8381SVivek Goyalconfig KEXEC_VERIFY_SIG
19648e7d8381SVivek Goyal	bool "Verify kernel signature during kexec_file_load() syscall"
196574ca317cSVivek Goyal	depends on KEXEC_FILE
19668e7d8381SVivek Goyal	---help---
19678e7d8381SVivek Goyal	  This option makes kernel signature verification mandatory for
1968d8eb8940SBorislav Petkov	  the kexec_file_load() syscall.
19698e7d8381SVivek Goyal
1970d8eb8940SBorislav Petkov	  In addition to that option, you need to enable signature
1971d8eb8940SBorislav Petkov	  verification for the corresponding kernel image type being
1972d8eb8940SBorislav Petkov	  loaded in order for this to work.
19738e7d8381SVivek Goyal
19748e7d8381SVivek Goyalconfig KEXEC_BZIMAGE_VERIFY_SIG
19758e7d8381SVivek Goyal	bool "Enable bzImage signature verification support"
19768e7d8381SVivek Goyal	depends on KEXEC_VERIFY_SIG
19778e7d8381SVivek Goyal	depends on SIGNED_PE_FILE_VERIFICATION
19788e7d8381SVivek Goyal	select SYSTEM_TRUSTED_KEYRING
19798e7d8381SVivek Goyal	---help---
19808e7d8381SVivek Goyal	  Enable bzImage signature verification support.
19818e7d8381SVivek Goyal
1982506f1d07SSam Ravnborgconfig CRASH_DUMP
198304b69447SPavel Machek	bool "kernel crash dumps"
1984506f1d07SSam Ravnborg	depends on X86_64 || (X86_32 && HIGHMEM)
19858f9ca475SIngo Molnar	---help---
1986506f1d07SSam Ravnborg	  Generate crash dump after being started by kexec.
1987506f1d07SSam Ravnborg	  This should be normally only set in special crash dump kernels
1988506f1d07SSam Ravnborg	  which are loaded in the main kernel with kexec-tools into
1989506f1d07SSam Ravnborg	  a specially reserved region and then later executed after
1990506f1d07SSam Ravnborg	  a crash by kdump/kexec. The crash dump kernel must be compiled
1991506f1d07SSam Ravnborg	  to a memory address not used by the main kernel or BIOS using
1992506f1d07SSam Ravnborg	  PHYSICAL_START, or it must be built as a relocatable image
1993506f1d07SSam Ravnborg	  (CONFIG_RELOCATABLE=y).
1994506f1d07SSam Ravnborg	  For more details see Documentation/kdump/kdump.txt
1995506f1d07SSam Ravnborg
19963ab83521SHuang Yingconfig KEXEC_JUMP
19976ea30386SKees Cook	bool "kexec jump"
1998fee7b0d8SHuang Ying	depends on KEXEC && HIBERNATION
19998f9ca475SIngo Molnar	---help---
200089081d17SHuang Ying	  Jump between original kernel and kexeced kernel and invoke
200189081d17SHuang Ying	  code in physical address mode via KEXEC
20023ab83521SHuang Ying
2003506f1d07SSam Ravnborgconfig PHYSICAL_START
20046a108a14SDavid Rientjes	hex "Physical address where the kernel is loaded" if (EXPERT || CRASH_DUMP)
2005ceefccc9SH. Peter Anvin	default "0x1000000"
20068f9ca475SIngo Molnar	---help---
2007506f1d07SSam Ravnborg	  This gives the physical address where the kernel is loaded.
2008506f1d07SSam Ravnborg
2009506f1d07SSam Ravnborg	  If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then
2010506f1d07SSam Ravnborg	  bzImage will decompress itself to above physical address and
2011506f1d07SSam Ravnborg	  run from there. Otherwise, bzImage will run from the address where
2012506f1d07SSam Ravnborg	  it has been loaded by the boot loader and will ignore above physical
2013506f1d07SSam Ravnborg	  address.
2014506f1d07SSam Ravnborg
2015506f1d07SSam Ravnborg	  In normal kdump cases one does not have to set/change this option
2016506f1d07SSam Ravnborg	  as now bzImage can be compiled as a completely relocatable image
2017506f1d07SSam Ravnborg	  (CONFIG_RELOCATABLE=y) and be used to load and run from a different
2018506f1d07SSam Ravnborg	  address. This option is mainly useful for the folks who don't want
2019506f1d07SSam Ravnborg	  to use a bzImage for capturing the crash dump and want to use a
2020506f1d07SSam Ravnborg	  vmlinux instead. vmlinux is not relocatable hence a kernel needs
2021506f1d07SSam Ravnborg	  to be specifically compiled to run from a specific memory area
2022506f1d07SSam Ravnborg	  (normally a reserved region) and this option comes handy.
2023506f1d07SSam Ravnborg
2024ceefccc9SH. Peter Anvin	  So if you are using bzImage for capturing the crash dump,
2025ceefccc9SH. Peter Anvin	  leave the value here unchanged to 0x1000000 and set
2026ceefccc9SH. Peter Anvin	  CONFIG_RELOCATABLE=y.  Otherwise if you plan to use vmlinux
2027ceefccc9SH. Peter Anvin	  for capturing the crash dump change this value to start of
2028ceefccc9SH. Peter Anvin	  the reserved region.  In other words, it can be set based on
2029ceefccc9SH. Peter Anvin	  the "X" value as specified in the "crashkernel=YM@XM"
2030ceefccc9SH. Peter Anvin	  command line boot parameter passed to the panic-ed
2031ceefccc9SH. Peter Anvin	  kernel. Please take a look at Documentation/kdump/kdump.txt
2032ceefccc9SH. Peter Anvin	  for more details about crash dumps.
2033506f1d07SSam Ravnborg
2034506f1d07SSam Ravnborg	  Usage of bzImage for capturing the crash dump is recommended as
2035506f1d07SSam Ravnborg	  one does not have to build two kernels. Same kernel can be used
2036506f1d07SSam Ravnborg	  as production kernel and capture kernel. Above option should have
2037506f1d07SSam Ravnborg	  gone away after relocatable bzImage support is introduced. But it
2038506f1d07SSam Ravnborg	  is present because there are users out there who continue to use
2039506f1d07SSam Ravnborg	  vmlinux for dump capture. This option should go away down the
2040506f1d07SSam Ravnborg	  line.
2041506f1d07SSam Ravnborg
2042506f1d07SSam Ravnborg	  Don't change this unless you know what you are doing.
2043506f1d07SSam Ravnborg
2044506f1d07SSam Ravnborgconfig RELOCATABLE
204526717808SH. Peter Anvin	bool "Build a relocatable kernel"
204626717808SH. Peter Anvin	default y
20478f9ca475SIngo Molnar	---help---
2048506f1d07SSam Ravnborg	  This builds a kernel image that retains relocation information
2049506f1d07SSam Ravnborg	  so it can be loaded someplace besides the default 1MB.
2050506f1d07SSam Ravnborg	  The relocations tend to make the kernel binary about 10% larger,
2051506f1d07SSam Ravnborg	  but are discarded at runtime.
2052506f1d07SSam Ravnborg
2053506f1d07SSam Ravnborg	  One use is for the kexec on panic case where the recovery kernel
2054506f1d07SSam Ravnborg	  must live at a different physical address than the primary
2055506f1d07SSam Ravnborg	  kernel.
2056506f1d07SSam Ravnborg
2057506f1d07SSam Ravnborg	  Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address
2058506f1d07SSam Ravnborg	  it has been loaded at and the compile time physical address
20598ab3820fSKees Cook	  (CONFIG_PHYSICAL_START) is used as the minimum location.
2060506f1d07SSam Ravnborg
20618ab3820fSKees Cookconfig RANDOMIZE_BASE
2062e8581e3dSBaoquan He	bool "Randomize the address of the kernel image (KASLR)"
20638ab3820fSKees Cook	depends on RELOCATABLE
20646807c846SIngo Molnar	default y
20658ab3820fSKees Cook	---help---
2066e8581e3dSBaoquan He	  In support of Kernel Address Space Layout Randomization (KASLR),
2067e8581e3dSBaoquan He	  this randomizes the physical address at which the kernel image
2068e8581e3dSBaoquan He	  is decompressed and the virtual address where the kernel
2069e8581e3dSBaoquan He	  image is mapped, as a security feature that deters exploit
2070e8581e3dSBaoquan He	  attempts relying on knowledge of the location of kernel
2071e8581e3dSBaoquan He	  code internals.
2072e8581e3dSBaoquan He
2073ed9f007eSKees Cook	  On 64-bit, the kernel physical and virtual addresses are
2074ed9f007eSKees Cook	  randomized separately. The physical address will be anywhere
2075ed9f007eSKees Cook	  between 16MB and the top of physical memory (up to 64TB). The
2076ed9f007eSKees Cook	  virtual address will be randomized from 16MB up to 1GB (9 bits
2077ed9f007eSKees Cook	  of entropy). Note that this also reduces the memory space
2078ed9f007eSKees Cook	  available to kernel modules from 1.5GB to 1GB.
2079ed9f007eSKees Cook
2080ed9f007eSKees Cook	  On 32-bit, the kernel physical and virtual addresses are
2081ed9f007eSKees Cook	  randomized together. They will be randomized from 16MB up to
2082ed9f007eSKees Cook	  512MB (8 bits of entropy).
20838ab3820fSKees Cook
2084a653f356SKees Cook	  Entropy is generated using the RDRAND instruction if it is
2085e8581e3dSBaoquan He	  supported. If RDTSC is supported, its value is mixed into
2086e8581e3dSBaoquan He	  the entropy pool as well. If neither RDRAND nor RDTSC are
2087ed9f007eSKees Cook	  supported, then entropy is read from the i8254 timer. The
2088ed9f007eSKees Cook	  usable entropy is limited by the kernel being built using
2089ed9f007eSKees Cook	  2GB addressing, and that PHYSICAL_ALIGN must be at a
2090ed9f007eSKees Cook	  minimum of 2MB. As a result, only 10 bits of entropy are
2091ed9f007eSKees Cook	  theoretically possible, but the implementations are further
2092ed9f007eSKees Cook	  limited due to memory layouts.
2093e8581e3dSBaoquan He
20946807c846SIngo Molnar	  If unsure, say Y.
2095da2b6fb9SKees Cook
20968ab3820fSKees Cook# Relocation on x86 needs some additional build support
2097845adf72SH. Peter Anvinconfig X86_NEED_RELOCS
2098845adf72SH. Peter Anvin	def_bool y
20998ab3820fSKees Cook	depends on RANDOMIZE_BASE || (X86_32 && RELOCATABLE)
2100845adf72SH. Peter Anvin
2101506f1d07SSam Ravnborgconfig PHYSICAL_ALIGN
2102a0215061SKees Cook	hex "Alignment value to which kernel should be aligned"
21038ab3820fSKees Cook	default "0x200000"
2104a0215061SKees Cook	range 0x2000 0x1000000 if X86_32
2105a0215061SKees Cook	range 0x200000 0x1000000 if X86_64
21068f9ca475SIngo Molnar	---help---
2107506f1d07SSam Ravnborg	  This value puts the alignment restrictions on physical address
2108506f1d07SSam Ravnborg	  where kernel is loaded and run from. Kernel is compiled for an
2109506f1d07SSam Ravnborg	  address which meets above alignment restriction.
2110506f1d07SSam Ravnborg
2111506f1d07SSam Ravnborg	  If bootloader loads the kernel at a non-aligned address and
2112506f1d07SSam Ravnborg	  CONFIG_RELOCATABLE is set, kernel will move itself to nearest
2113506f1d07SSam Ravnborg	  address aligned to above value and run from there.
2114506f1d07SSam Ravnborg
2115506f1d07SSam Ravnborg	  If bootloader loads the kernel at a non-aligned address and
2116506f1d07SSam Ravnborg	  CONFIG_RELOCATABLE is not set, kernel will ignore the run time
2117506f1d07SSam Ravnborg	  load address and decompress itself to the address it has been
2118506f1d07SSam Ravnborg	  compiled for and run from there. The address for which kernel is
2119506f1d07SSam Ravnborg	  compiled already meets above alignment restrictions. Hence the
2120506f1d07SSam Ravnborg	  end result is that kernel runs from a physical address meeting
2121506f1d07SSam Ravnborg	  above alignment restrictions.
2122506f1d07SSam Ravnborg
2123a0215061SKees Cook	  On 32-bit this value must be a multiple of 0x2000. On 64-bit
2124a0215061SKees Cook	  this value must be a multiple of 0x200000.
2125a0215061SKees Cook
2126506f1d07SSam Ravnborg	  Don't change this unless you know what you are doing.
2127506f1d07SSam Ravnborg
21280483e1faSThomas Garnierconfig RANDOMIZE_MEMORY
21290483e1faSThomas Garnier	bool "Randomize the kernel memory sections"
21300483e1faSThomas Garnier	depends on X86_64
21310483e1faSThomas Garnier	depends on RANDOMIZE_BASE
21320483e1faSThomas Garnier	default RANDOMIZE_BASE
21330483e1faSThomas Garnier	---help---
21340483e1faSThomas Garnier	   Randomizes the base virtual address of kernel memory sections
21350483e1faSThomas Garnier	   (physical memory mapping, vmalloc & vmemmap). This security feature
21360483e1faSThomas Garnier	   makes exploits relying on predictable memory locations less reliable.
21370483e1faSThomas Garnier
21380483e1faSThomas Garnier	   The order of allocations remains unchanged. Entropy is generated in
21390483e1faSThomas Garnier	   the same way as RANDOMIZE_BASE. Current implementation in the optimal
21400483e1faSThomas Garnier	   configuration have in average 30,000 different possible virtual
21410483e1faSThomas Garnier	   addresses for each memory section.
21420483e1faSThomas Garnier
21436807c846SIngo Molnar	   If unsure, say Y.
21440483e1faSThomas Garnier
214590397a41SThomas Garnierconfig RANDOMIZE_MEMORY_PHYSICAL_PADDING
214690397a41SThomas Garnier	hex "Physical memory mapping padding" if EXPERT
214790397a41SThomas Garnier	depends on RANDOMIZE_MEMORY
214890397a41SThomas Garnier	default "0xa" if MEMORY_HOTPLUG
214990397a41SThomas Garnier	default "0x0"
215090397a41SThomas Garnier	range 0x1 0x40 if MEMORY_HOTPLUG
215190397a41SThomas Garnier	range 0x0 0x40
215290397a41SThomas Garnier	---help---
215390397a41SThomas Garnier	   Define the padding in terabytes added to the existing physical
215490397a41SThomas Garnier	   memory size during kernel memory randomization. It is useful
215590397a41SThomas Garnier	   for memory hotplug support but reduces the entropy available for
215690397a41SThomas Garnier	   address randomization.
215790397a41SThomas Garnier
215890397a41SThomas Garnier	   If unsure, leave at the default value.
215990397a41SThomas Garnier
2160506f1d07SSam Ravnborgconfig HOTPLUG_CPU
21617c13e6a3SDimitri Sivanich	bool "Support for hot-pluggable CPUs"
216240b31360SStephen Rothwell	depends on SMP
2163506f1d07SSam Ravnborg	---help---
21647c13e6a3SDimitri Sivanich	  Say Y here to allow turning CPUs off and on. CPUs can be
21657c13e6a3SDimitri Sivanich	  controlled through /sys/devices/system/cpu.
21667c13e6a3SDimitri Sivanich	  ( Note: power management support will enable this option
21677c13e6a3SDimitri Sivanich	    automatically on SMP systems. )
21687c13e6a3SDimitri Sivanich	  Say N if you want to disable CPU hotplug.
2169506f1d07SSam Ravnborg
217080aa1dffSFenghua Yuconfig BOOTPARAM_HOTPLUG_CPU0
217180aa1dffSFenghua Yu	bool "Set default setting of cpu0_hotpluggable"
217280aa1dffSFenghua Yu	default n
21732c922cd0SKees Cook	depends on HOTPLUG_CPU
217480aa1dffSFenghua Yu	---help---
217580aa1dffSFenghua Yu	  Set whether default state of cpu0_hotpluggable is on or off.
217680aa1dffSFenghua Yu
217780aa1dffSFenghua Yu	  Say Y here to enable CPU0 hotplug by default. If this switch
217880aa1dffSFenghua Yu	  is turned on, there is no need to give cpu0_hotplug kernel
217980aa1dffSFenghua Yu	  parameter and the CPU0 hotplug feature is enabled by default.
218080aa1dffSFenghua Yu
218180aa1dffSFenghua Yu	  Please note: there are two known CPU0 dependencies if you want
218280aa1dffSFenghua Yu	  to enable the CPU0 hotplug feature either by this switch or by
218380aa1dffSFenghua Yu	  cpu0_hotplug kernel parameter.
218480aa1dffSFenghua Yu
218580aa1dffSFenghua Yu	  First, resume from hibernate or suspend always starts from CPU0.
218680aa1dffSFenghua Yu	  So hibernate and suspend are prevented if CPU0 is offline.
218780aa1dffSFenghua Yu
218880aa1dffSFenghua Yu	  Second dependency is PIC interrupts always go to CPU0. CPU0 can not
218980aa1dffSFenghua Yu	  offline if any interrupt can not migrate out of CPU0. There may
219080aa1dffSFenghua Yu	  be other CPU0 dependencies.
219180aa1dffSFenghua Yu
219280aa1dffSFenghua Yu	  Please make sure the dependencies are under your control before
219380aa1dffSFenghua Yu	  you enable this feature.
219480aa1dffSFenghua Yu
219580aa1dffSFenghua Yu	  Say N if you don't want to enable CPU0 hotplug feature by default.
219680aa1dffSFenghua Yu	  You still can enable the CPU0 hotplug feature at boot by kernel
219780aa1dffSFenghua Yu	  parameter cpu0_hotplug.
219880aa1dffSFenghua Yu
2199a71c8bc5SFenghua Yuconfig DEBUG_HOTPLUG_CPU0
2200a71c8bc5SFenghua Yu	def_bool n
2201a71c8bc5SFenghua Yu	prompt "Debug CPU0 hotplug"
22022c922cd0SKees Cook	depends on HOTPLUG_CPU
2203a71c8bc5SFenghua Yu	---help---
2204a71c8bc5SFenghua Yu	  Enabling this option offlines CPU0 (if CPU0 can be offlined) as
2205a71c8bc5SFenghua Yu	  soon as possible and boots up userspace with CPU0 offlined. User
2206a71c8bc5SFenghua Yu	  can online CPU0 back after boot time.
2207a71c8bc5SFenghua Yu
2208a71c8bc5SFenghua Yu	  To debug CPU0 hotplug, you need to enable CPU0 offline/online
2209a71c8bc5SFenghua Yu	  feature by either turning on CONFIG_BOOTPARAM_HOTPLUG_CPU0 during
2210a71c8bc5SFenghua Yu	  compilation or giving cpu0_hotplug kernel parameter at boot.
2211a71c8bc5SFenghua Yu
2212a71c8bc5SFenghua Yu	  If unsure, say N.
2213a71c8bc5SFenghua Yu
2214506f1d07SSam Ravnborgconfig COMPAT_VDSO
2215b0b49f26SAndy Lutomirski	def_bool n
2216b0b49f26SAndy Lutomirski	prompt "Disable the 32-bit vDSO (needed for glibc 2.3.3)"
2217953fee1dSIngo Molnar	depends on COMPAT_32
22188f9ca475SIngo Molnar	---help---
2219b0b49f26SAndy Lutomirski	  Certain buggy versions of glibc will crash if they are
2220b0b49f26SAndy Lutomirski	  presented with a 32-bit vDSO that is not mapped at the address
2221b0b49f26SAndy Lutomirski	  indicated in its segment table.
2222e84446deSRandy Dunlap
2223b0b49f26SAndy Lutomirski	  The bug was introduced by f866314b89d56845f55e6f365e18b31ec978ec3a
2224b0b49f26SAndy Lutomirski	  and fixed by 3b3ddb4f7db98ec9e912ccdf54d35df4aa30e04a and
2225b0b49f26SAndy Lutomirski	  49ad572a70b8aeb91e57483a11dd1b77e31c4468.  Glibc 2.3.3 is
2226b0b49f26SAndy Lutomirski	  the only released version with the bug, but OpenSUSE 9
2227b0b49f26SAndy Lutomirski	  contains a buggy "glibc 2.3.2".
2228506f1d07SSam Ravnborg
2229b0b49f26SAndy Lutomirski	  The symptom of the bug is that everything crashes on startup, saying:
2230b0b49f26SAndy Lutomirski	  dl_main: Assertion `(void *) ph->p_vaddr == _rtld_local._dl_sysinfo_dso' failed!
2231b0b49f26SAndy Lutomirski
2232b0b49f26SAndy Lutomirski	  Saying Y here changes the default value of the vdso32 boot
2233b0b49f26SAndy Lutomirski	  option from 1 to 0, which turns off the 32-bit vDSO entirely.
2234b0b49f26SAndy Lutomirski	  This works around the glibc bug but hurts performance.
2235b0b49f26SAndy Lutomirski
2236b0b49f26SAndy Lutomirski	  If unsure, say N: if you are compiling your own kernel, you
2237b0b49f26SAndy Lutomirski	  are unlikely to be using a buggy version of glibc.
2238506f1d07SSam Ravnborg
22393dc33bd3SKees Cookchoice
22403dc33bd3SKees Cook	prompt "vsyscall table for legacy applications"
22413dc33bd3SKees Cook	depends on X86_64
22423dc33bd3SKees Cook	default LEGACY_VSYSCALL_EMULATE
22433dc33bd3SKees Cook	help
22443dc33bd3SKees Cook	  Legacy user code that does not know how to find the vDSO expects
22453dc33bd3SKees Cook	  to be able to issue three syscalls by calling fixed addresses in
22463dc33bd3SKees Cook	  kernel space. Since this location is not randomized with ASLR,
22473dc33bd3SKees Cook	  it can be used to assist security vulnerability exploitation.
22483dc33bd3SKees Cook
22493dc33bd3SKees Cook	  This setting can be changed at boot time via the kernel command
22503dc33bd3SKees Cook	  line parameter vsyscall=[native|emulate|none].
22513dc33bd3SKees Cook
22523dc33bd3SKees Cook	  On a system with recent enough glibc (2.14 or newer) and no
22533dc33bd3SKees Cook	  static binaries, you can say None without a performance penalty
22543dc33bd3SKees Cook	  to improve security.
22553dc33bd3SKees Cook
22563dc33bd3SKees Cook	  If unsure, select "Emulate".
22573dc33bd3SKees Cook
22583dc33bd3SKees Cook	config LEGACY_VSYSCALL_NATIVE
22593dc33bd3SKees Cook		bool "Native"
22603dc33bd3SKees Cook		help
22613dc33bd3SKees Cook		  Actual executable code is located in the fixed vsyscall
22623dc33bd3SKees Cook		  address mapping, implementing time() efficiently. Since
22633dc33bd3SKees Cook		  this makes the mapping executable, it can be used during
22643dc33bd3SKees Cook		  security vulnerability exploitation (traditionally as
22653dc33bd3SKees Cook		  ROP gadgets). This configuration is not recommended.
22663dc33bd3SKees Cook
22673dc33bd3SKees Cook	config LEGACY_VSYSCALL_EMULATE
22683dc33bd3SKees Cook		bool "Emulate"
22693dc33bd3SKees Cook		help
22703dc33bd3SKees Cook		  The kernel traps and emulates calls into the fixed
22713dc33bd3SKees Cook		  vsyscall address mapping. This makes the mapping
22723dc33bd3SKees Cook		  non-executable, but it still contains known contents,
22733dc33bd3SKees Cook		  which could be used in certain rare security vulnerability
22743dc33bd3SKees Cook		  exploits. This configuration is recommended when userspace
22753dc33bd3SKees Cook		  still uses the vsyscall area.
22763dc33bd3SKees Cook
22773dc33bd3SKees Cook	config LEGACY_VSYSCALL_NONE
22783dc33bd3SKees Cook		bool "None"
22793dc33bd3SKees Cook		help
22803dc33bd3SKees Cook		  There will be no vsyscall mapping at all. This will
22813dc33bd3SKees Cook		  eliminate any risk of ASLR bypass due to the vsyscall
22823dc33bd3SKees Cook		  fixed address mapping. Attempts to use the vsyscalls
22833dc33bd3SKees Cook		  will be reported to dmesg, so that either old or
22843dc33bd3SKees Cook		  malicious userspace programs can be identified.
22853dc33bd3SKees Cook
22863dc33bd3SKees Cookendchoice
22873dc33bd3SKees Cook
2288516cbf37STim Birdconfig CMDLINE_BOOL
2289516cbf37STim Bird	bool "Built-in kernel command line"
22908f9ca475SIngo Molnar	---help---
2291516cbf37STim Bird	  Allow for specifying boot arguments to the kernel at
2292516cbf37STim Bird	  build time.  On some systems (e.g. embedded ones), it is
2293516cbf37STim Bird	  necessary or convenient to provide some or all of the
2294516cbf37STim Bird	  kernel boot arguments with the kernel itself (that is,
2295516cbf37STim Bird	  to not rely on the boot loader to provide them.)
2296516cbf37STim Bird
2297516cbf37STim Bird	  To compile command line arguments into the kernel,
2298516cbf37STim Bird	  set this option to 'Y', then fill in the
229969711ca1SSébastien Hinderer	  boot arguments in CONFIG_CMDLINE.
2300516cbf37STim Bird
2301516cbf37STim Bird	  Systems with fully functional boot loaders (i.e. non-embedded)
2302516cbf37STim Bird	  should leave this option set to 'N'.
2303516cbf37STim Bird
2304516cbf37STim Birdconfig CMDLINE
2305516cbf37STim Bird	string "Built-in kernel command string"
2306516cbf37STim Bird	depends on CMDLINE_BOOL
2307516cbf37STim Bird	default ""
23088f9ca475SIngo Molnar	---help---
2309516cbf37STim Bird	  Enter arguments here that should be compiled into the kernel
2310516cbf37STim Bird	  image and used at boot time.  If the boot loader provides a
2311516cbf37STim Bird	  command line at boot time, it is appended to this string to
2312516cbf37STim Bird	  form the full kernel command line, when the system boots.
2313516cbf37STim Bird
2314516cbf37STim Bird	  However, you can use the CONFIG_CMDLINE_OVERRIDE option to
2315516cbf37STim Bird	  change this behavior.
2316516cbf37STim Bird
2317516cbf37STim Bird	  In most cases, the command line (whether built-in or provided
2318516cbf37STim Bird	  by the boot loader) should specify the device for the root
2319516cbf37STim Bird	  file system.
2320516cbf37STim Bird
2321516cbf37STim Birdconfig CMDLINE_OVERRIDE
2322516cbf37STim Bird	bool "Built-in command line overrides boot loader arguments"
2323516cbf37STim Bird	depends on CMDLINE_BOOL
23248f9ca475SIngo Molnar	---help---
2325516cbf37STim Bird	  Set this option to 'Y' to have the kernel ignore the boot loader
2326516cbf37STim Bird	  command line, and use ONLY the built-in command line.
2327516cbf37STim Bird
2328516cbf37STim Bird	  This is used to work around broken boot loaders.  This should
2329516cbf37STim Bird	  be set to 'N' under normal conditions.
2330516cbf37STim Bird
2331a5b9e5a2SAndy Lutomirskiconfig MODIFY_LDT_SYSCALL
2332a5b9e5a2SAndy Lutomirski	bool "Enable the LDT (local descriptor table)" if EXPERT
2333a5b9e5a2SAndy Lutomirski	default y
2334a5b9e5a2SAndy Lutomirski	---help---
2335a5b9e5a2SAndy Lutomirski	  Linux can allow user programs to install a per-process x86
2336a5b9e5a2SAndy Lutomirski	  Local Descriptor Table (LDT) using the modify_ldt(2) system
2337a5b9e5a2SAndy Lutomirski	  call.  This is required to run 16-bit or segmented code such as
2338a5b9e5a2SAndy Lutomirski	  DOSEMU or some Wine programs.  It is also used by some very old
2339a5b9e5a2SAndy Lutomirski	  threading libraries.
2340a5b9e5a2SAndy Lutomirski
2341a5b9e5a2SAndy Lutomirski	  Enabling this feature adds a small amount of overhead to
2342a5b9e5a2SAndy Lutomirski	  context switches and increases the low-level kernel attack
2343a5b9e5a2SAndy Lutomirski	  surface.  Disabling it removes the modify_ldt(2) system call.
2344a5b9e5a2SAndy Lutomirski
2345a5b9e5a2SAndy Lutomirski	  Saying 'N' here may make sense for embedded or server kernels.
2346a5b9e5a2SAndy Lutomirski
2347b700e7f0SSeth Jenningssource "kernel/livepatch/Kconfig"
2348b700e7f0SSeth Jennings
2349506f1d07SSam Ravnborgendmenu
2350506f1d07SSam Ravnborg
23513072e413SMichal Hockoconfig ARCH_HAS_ADD_PAGES
23523072e413SMichal Hocko	def_bool y
23533072e413SMichal Hocko	depends on X86_64 && ARCH_ENABLE_MEMORY_HOTPLUG
23543072e413SMichal Hocko
2355506f1d07SSam Ravnborgconfig ARCH_ENABLE_MEMORY_HOTPLUG
2356506f1d07SSam Ravnborg	def_bool y
2357506f1d07SSam Ravnborg	depends on X86_64 || (X86_32 && HIGHMEM)
2358506f1d07SSam Ravnborg
235935551053SGary Hadeconfig ARCH_ENABLE_MEMORY_HOTREMOVE
236035551053SGary Hade	def_bool y
236135551053SGary Hade	depends on MEMORY_HOTPLUG
236235551053SGary Hade
2363e534c7c5SLee Schermerhornconfig USE_PERCPU_NUMA_NODE_ID
2364645a7919STejun Heo	def_bool y
2365e534c7c5SLee Schermerhorn	depends on NUMA
2366e534c7c5SLee Schermerhorn
23679491846fSKirill A. Shutemovconfig ARCH_ENABLE_SPLIT_PMD_PTLOCK
23689491846fSKirill A. Shutemov	def_bool y
23699491846fSKirill A. Shutemov	depends on X86_64 || X86_PAE
23709491846fSKirill A. Shutemov
2371c177c81eSNaoya Horiguchiconfig ARCH_ENABLE_HUGEPAGE_MIGRATION
2372c177c81eSNaoya Horiguchi	def_bool y
2373c177c81eSNaoya Horiguchi	depends on X86_64 && HUGETLB_PAGE && MIGRATION
2374c177c81eSNaoya Horiguchi
23759c670ea3SNaoya Horiguchiconfig ARCH_ENABLE_THP_MIGRATION
23769c670ea3SNaoya Horiguchi	def_bool y
23779c670ea3SNaoya Horiguchi	depends on X86_64 && TRANSPARENT_HUGEPAGE
23789c670ea3SNaoya Horiguchi
2379da85f865SBjorn Helgaasmenu "Power management and ACPI options"
2380e279b6c1SSam Ravnborg
2381e279b6c1SSam Ravnborgconfig ARCH_HIBERNATION_HEADER
23823c2362e6SHarvey Harrison	def_bool y
2383e279b6c1SSam Ravnborg	depends on X86_64 && HIBERNATION
2384e279b6c1SSam Ravnborg
2385e279b6c1SSam Ravnborgsource "kernel/power/Kconfig"
2386e279b6c1SSam Ravnborg
2387e279b6c1SSam Ravnborgsource "drivers/acpi/Kconfig"
2388e279b6c1SSam Ravnborg
2389efafc8b2SFeng Tangsource "drivers/sfi/Kconfig"
2390efafc8b2SFeng Tang
2391a6b68076SAndi Kleenconfig X86_APM_BOOT
23926fc108a0SJan Beulich	def_bool y
2393282e5aabSPaul Bolle	depends on APM
2394a6b68076SAndi Kleen
2395e279b6c1SSam Ravnborgmenuconfig APM
2396e279b6c1SSam Ravnborg	tristate "APM (Advanced Power Management) BIOS support"
2397efefa6f6SIngo Molnar	depends on X86_32 && PM_SLEEP
2398e279b6c1SSam Ravnborg	---help---
2399e279b6c1SSam Ravnborg	  APM is a BIOS specification for saving power using several different
2400e279b6c1SSam Ravnborg	  techniques. This is mostly useful for battery powered laptops with
2401e279b6c1SSam Ravnborg	  APM compliant BIOSes. If you say Y here, the system time will be
2402e279b6c1SSam Ravnborg	  reset after a RESUME operation, the /proc/apm device will provide
2403e279b6c1SSam Ravnborg	  battery status information, and user-space programs will receive
2404e279b6c1SSam Ravnborg	  notification of APM "events" (e.g. battery status change).
2405e279b6c1SSam Ravnborg
2406e279b6c1SSam Ravnborg	  If you select "Y" here, you can disable actual use of the APM
2407e279b6c1SSam Ravnborg	  BIOS by passing the "apm=off" option to the kernel at boot time.
2408e279b6c1SSam Ravnborg
2409e279b6c1SSam Ravnborg	  Note that the APM support is almost completely disabled for
2410e279b6c1SSam Ravnborg	  machines with more than one CPU.
2411e279b6c1SSam Ravnborg
2412e279b6c1SSam Ravnborg	  In order to use APM, you will need supporting software. For location
24132dc98fd3SMichael Witten	  and more information, read <file:Documentation/power/apm-acpi.txt>
24142dc98fd3SMichael Witten	  and the Battery Powered Linux mini-HOWTO, available from
2415e279b6c1SSam Ravnborg	  <http://www.tldp.org/docs.html#howto>.
2416e279b6c1SSam Ravnborg
2417e279b6c1SSam Ravnborg	  This driver does not spin down disk drives (see the hdparm(8)
2418e279b6c1SSam Ravnborg	  manpage ("man 8 hdparm") for that), and it doesn't turn off
2419e279b6c1SSam Ravnborg	  VESA-compliant "green" monitors.
2420e279b6c1SSam Ravnborg
2421e279b6c1SSam Ravnborg	  This driver does not support the TI 4000M TravelMate and the ACER
2422e279b6c1SSam Ravnborg	  486/DX4/75 because they don't have compliant BIOSes. Many "green"
2423e279b6c1SSam Ravnborg	  desktop machines also don't have compliant BIOSes, and this driver
2424e279b6c1SSam Ravnborg	  may cause those machines to panic during the boot phase.
2425e279b6c1SSam Ravnborg
2426e279b6c1SSam Ravnborg	  Generally, if you don't have a battery in your machine, there isn't
2427e279b6c1SSam Ravnborg	  much point in using this driver and you should say N. If you get
2428e279b6c1SSam Ravnborg	  random kernel OOPSes or reboots that don't seem to be related to
2429e279b6c1SSam Ravnborg	  anything, try disabling/enabling this option (or disabling/enabling
2430e279b6c1SSam Ravnborg	  APM in your BIOS).
2431e279b6c1SSam Ravnborg
2432e279b6c1SSam Ravnborg	  Some other things you should try when experiencing seemingly random,
2433e279b6c1SSam Ravnborg	  "weird" problems:
2434e279b6c1SSam Ravnborg
2435e279b6c1SSam Ravnborg	  1) make sure that you have enough swap space and that it is
2436e279b6c1SSam Ravnborg	  enabled.
2437e279b6c1SSam Ravnborg	  2) pass the "no-hlt" option to the kernel
2438e279b6c1SSam Ravnborg	  3) switch on floating point emulation in the kernel and pass
2439e279b6c1SSam Ravnborg	  the "no387" option to the kernel
2440e279b6c1SSam Ravnborg	  4) pass the "floppy=nodma" option to the kernel
2441e279b6c1SSam Ravnborg	  5) pass the "mem=4M" option to the kernel (thereby disabling
2442e279b6c1SSam Ravnborg	  all but the first 4 MB of RAM)
2443e279b6c1SSam Ravnborg	  6) make sure that the CPU is not over clocked.
2444e279b6c1SSam Ravnborg	  7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/>
2445e279b6c1SSam Ravnborg	  8) disable the cache from your BIOS settings
2446e279b6c1SSam Ravnborg	  9) install a fan for the video card or exchange video RAM
2447e279b6c1SSam Ravnborg	  10) install a better fan for the CPU
2448e279b6c1SSam Ravnborg	  11) exchange RAM chips
2449e279b6c1SSam Ravnborg	  12) exchange the motherboard.
2450e279b6c1SSam Ravnborg
2451e279b6c1SSam Ravnborg	  To compile this driver as a module, choose M here: the
2452e279b6c1SSam Ravnborg	  module will be called apm.
2453e279b6c1SSam Ravnborg
2454e279b6c1SSam Ravnborgif APM
2455e279b6c1SSam Ravnborg
2456e279b6c1SSam Ravnborgconfig APM_IGNORE_USER_SUSPEND
2457e279b6c1SSam Ravnborg	bool "Ignore USER SUSPEND"
24588f9ca475SIngo Molnar	---help---
2459e279b6c1SSam Ravnborg	  This option will ignore USER SUSPEND requests. On machines with a
2460e279b6c1SSam Ravnborg	  compliant APM BIOS, you want to say N. However, on the NEC Versa M
2461e279b6c1SSam Ravnborg	  series notebooks, it is necessary to say Y because of a BIOS bug.
2462e279b6c1SSam Ravnborg
2463e279b6c1SSam Ravnborgconfig APM_DO_ENABLE
2464e279b6c1SSam Ravnborg	bool "Enable PM at boot time"
2465e279b6c1SSam Ravnborg	---help---
2466e279b6c1SSam Ravnborg	  Enable APM features at boot time. From page 36 of the APM BIOS
2467e279b6c1SSam Ravnborg	  specification: "When disabled, the APM BIOS does not automatically
2468e279b6c1SSam Ravnborg	  power manage devices, enter the Standby State, enter the Suspend
2469e279b6c1SSam Ravnborg	  State, or take power saving steps in response to CPU Idle calls."
2470e279b6c1SSam Ravnborg	  This driver will make CPU Idle calls when Linux is idle (unless this
2471e279b6c1SSam Ravnborg	  feature is turned off -- see "Do CPU IDLE calls", below). This
2472e279b6c1SSam Ravnborg	  should always save battery power, but more complicated APM features
2473e279b6c1SSam Ravnborg	  will be dependent on your BIOS implementation. You may need to turn
2474e279b6c1SSam Ravnborg	  this option off if your computer hangs at boot time when using APM
2475e279b6c1SSam Ravnborg	  support, or if it beeps continuously instead of suspending. Turn
2476e279b6c1SSam Ravnborg	  this off if you have a NEC UltraLite Versa 33/C or a Toshiba
2477e279b6c1SSam Ravnborg	  T400CDT. This is off by default since most machines do fine without
2478e279b6c1SSam Ravnborg	  this feature.
2479e279b6c1SSam Ravnborg
2480e279b6c1SSam Ravnborgconfig APM_CPU_IDLE
2481dd8af076SLen Brown	depends on CPU_IDLE
2482e279b6c1SSam Ravnborg	bool "Make CPU Idle calls when idle"
24838f9ca475SIngo Molnar	---help---
2484e279b6c1SSam Ravnborg	  Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop.
2485e279b6c1SSam Ravnborg	  On some machines, this can activate improved power savings, such as
2486e279b6c1SSam Ravnborg	  a slowed CPU clock rate, when the machine is idle. These idle calls
2487e279b6c1SSam Ravnborg	  are made after the idle loop has run for some length of time (e.g.,
2488e279b6c1SSam Ravnborg	  333 mS). On some machines, this will cause a hang at boot time or
2489e279b6c1SSam Ravnborg	  whenever the CPU becomes idle. (On machines with more than one CPU,
2490e279b6c1SSam Ravnborg	  this option does nothing.)
2491e279b6c1SSam Ravnborg
2492e279b6c1SSam Ravnborgconfig APM_DISPLAY_BLANK
2493e279b6c1SSam Ravnborg	bool "Enable console blanking using APM"
24948f9ca475SIngo Molnar	---help---
2495e279b6c1SSam Ravnborg	  Enable console blanking using the APM. Some laptops can use this to
2496e279b6c1SSam Ravnborg	  turn off the LCD backlight when the screen blanker of the Linux
2497e279b6c1SSam Ravnborg	  virtual console blanks the screen. Note that this is only used by
2498e279b6c1SSam Ravnborg	  the virtual console screen blanker, and won't turn off the backlight
2499e279b6c1SSam Ravnborg	  when using the X Window system. This also doesn't have anything to
2500e279b6c1SSam Ravnborg	  do with your VESA-compliant power-saving monitor. Further, this
2501e279b6c1SSam Ravnborg	  option doesn't work for all laptops -- it might not turn off your
2502e279b6c1SSam Ravnborg	  backlight at all, or it might print a lot of errors to the console,
2503e279b6c1SSam Ravnborg	  especially if you are using gpm.
2504e279b6c1SSam Ravnborg
2505e279b6c1SSam Ravnborgconfig APM_ALLOW_INTS
2506e279b6c1SSam Ravnborg	bool "Allow interrupts during APM BIOS calls"
25078f9ca475SIngo Molnar	---help---
2508e279b6c1SSam Ravnborg	  Normally we disable external interrupts while we are making calls to
2509e279b6c1SSam Ravnborg	  the APM BIOS as a measure to lessen the effects of a badly behaving
2510e279b6c1SSam Ravnborg	  BIOS implementation.  The BIOS should reenable interrupts if it
2511e279b6c1SSam Ravnborg	  needs to.  Unfortunately, some BIOSes do not -- especially those in
2512e279b6c1SSam Ravnborg	  many of the newer IBM Thinkpads.  If you experience hangs when you
2513e279b6c1SSam Ravnborg	  suspend, try setting this to Y.  Otherwise, say N.
2514e279b6c1SSam Ravnborg
2515e279b6c1SSam Ravnborgendif # APM
2516e279b6c1SSam Ravnborg
2517bb0a56ecSDave Jonessource "drivers/cpufreq/Kconfig"
2518e279b6c1SSam Ravnborg
2519e279b6c1SSam Ravnborgsource "drivers/cpuidle/Kconfig"
2520e279b6c1SSam Ravnborg
252127471fdbSAndy Henroidsource "drivers/idle/Kconfig"
252227471fdbSAndy Henroid
2523e279b6c1SSam Ravnborgendmenu
2524e279b6c1SSam Ravnborg
2525e279b6c1SSam Ravnborg
2526e279b6c1SSam Ravnborgmenu "Bus options (PCI etc.)"
2527e279b6c1SSam Ravnborg
2528e279b6c1SSam Ravnborgconfig PCI
25291ac97018SIngo Molnar	bool "PCI support"
25301c858087SAdrian Bunk	default y
25318f9ca475SIngo Molnar	---help---
2532e279b6c1SSam Ravnborg	  Find out whether you have a PCI motherboard. PCI is the name of a
2533e279b6c1SSam Ravnborg	  bus system, i.e. the way the CPU talks to the other stuff inside
2534e279b6c1SSam Ravnborg	  your box. Other bus systems are ISA, EISA, MicroChannel (MCA) or
2535e279b6c1SSam Ravnborg	  VESA. If you have PCI, say Y, otherwise N.
2536e279b6c1SSam Ravnborg
2537e279b6c1SSam Ravnborgchoice
2538e279b6c1SSam Ravnborg	prompt "PCI access mode"
2539efefa6f6SIngo Molnar	depends on X86_32 && PCI
2540e279b6c1SSam Ravnborg	default PCI_GOANY
2541e279b6c1SSam Ravnborg	---help---
2542e279b6c1SSam Ravnborg	  On PCI systems, the BIOS can be used to detect the PCI devices and
2543e279b6c1SSam Ravnborg	  determine their configuration. However, some old PCI motherboards
2544e279b6c1SSam Ravnborg	  have BIOS bugs and may crash if this is done. Also, some embedded
2545e279b6c1SSam Ravnborg	  PCI-based systems don't have any BIOS at all. Linux can also try to
2546e279b6c1SSam Ravnborg	  detect the PCI hardware directly without using the BIOS.
2547e279b6c1SSam Ravnborg
2548e279b6c1SSam Ravnborg	  With this option, you can specify how Linux should detect the
2549e279b6c1SSam Ravnborg	  PCI devices. If you choose "BIOS", the BIOS will be used,
2550e279b6c1SSam Ravnborg	  if you choose "Direct", the BIOS won't be used, and if you
2551e279b6c1SSam Ravnborg	  choose "MMConfig", then PCI Express MMCONFIG will be used.
2552e279b6c1SSam Ravnborg	  If you choose "Any", the kernel will try MMCONFIG, then the
2553e279b6c1SSam Ravnborg	  direct access method and falls back to the BIOS if that doesn't
2554e279b6c1SSam Ravnborg	  work. If unsure, go with the default, which is "Any".
2555e279b6c1SSam Ravnborg
2556e279b6c1SSam Ravnborgconfig PCI_GOBIOS
2557e279b6c1SSam Ravnborg	bool "BIOS"
2558e279b6c1SSam Ravnborg
2559e279b6c1SSam Ravnborgconfig PCI_GOMMCONFIG
2560e279b6c1SSam Ravnborg	bool "MMConfig"
2561e279b6c1SSam Ravnborg
2562e279b6c1SSam Ravnborgconfig PCI_GODIRECT
2563e279b6c1SSam Ravnborg	bool "Direct"
2564e279b6c1SSam Ravnborg
25653ef0e1f8SAndres Salomonconfig PCI_GOOLPC
256676fb6570SDaniel Drake	bool "OLPC XO-1"
25673ef0e1f8SAndres Salomon	depends on OLPC
25683ef0e1f8SAndres Salomon
25692bdd1b03SAndres Salomonconfig PCI_GOANY
25702bdd1b03SAndres Salomon	bool "Any"
25712bdd1b03SAndres Salomon
2572e279b6c1SSam Ravnborgendchoice
2573e279b6c1SSam Ravnborg
2574e279b6c1SSam Ravnborgconfig PCI_BIOS
25753c2362e6SHarvey Harrison	def_bool y
2576efefa6f6SIngo Molnar	depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY)
2577e279b6c1SSam Ravnborg
2578e279b6c1SSam Ravnborg# x86-64 doesn't support PCI BIOS access from long mode so always go direct.
2579e279b6c1SSam Ravnborgconfig PCI_DIRECT
25803c2362e6SHarvey Harrison	def_bool y
25810aba496fSShaohua Li	depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC || PCI_GOMMCONFIG))
2582e279b6c1SSam Ravnborg
2583e279b6c1SSam Ravnborgconfig PCI_MMCONFIG
25843c2362e6SHarvey Harrison	def_bool y
25855f0db7a2SFeng Tang	depends on X86_32 && PCI && (ACPI || SFI) && (PCI_GOMMCONFIG || PCI_GOANY)
2586e279b6c1SSam Ravnborg
25873ef0e1f8SAndres Salomonconfig PCI_OLPC
25882bdd1b03SAndres Salomon	def_bool y
25892bdd1b03SAndres Salomon	depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY)
25903ef0e1f8SAndres Salomon
2591b5401a96SAlex Nixonconfig PCI_XEN
2592b5401a96SAlex Nixon	def_bool y
2593b5401a96SAlex Nixon	depends on PCI && XEN
2594b5401a96SAlex Nixon	select SWIOTLB_XEN
2595b5401a96SAlex Nixon
2596e279b6c1SSam Ravnborgconfig PCI_DOMAINS
25973c2362e6SHarvey Harrison	def_bool y
2598e279b6c1SSam Ravnborg	depends on PCI
2599e279b6c1SSam Ravnborg
2600e279b6c1SSam Ravnborgconfig PCI_MMCONFIG
2601e279b6c1SSam Ravnborg	bool "Support mmconfig PCI config space access"
2602e279b6c1SSam Ravnborg	depends on X86_64 && PCI && ACPI
2603e279b6c1SSam Ravnborg
26043f6ea84aSIra W. Snyderconfig PCI_CNB20LE_QUIRK
26056a108a14SDavid Rientjes	bool "Read CNB20LE Host Bridge Windows" if EXPERT
26066ea30386SKees Cook	depends on PCI
26073f6ea84aSIra W. Snyder	help
26083f6ea84aSIra W. Snyder	  Read the PCI windows out of the CNB20LE host bridge. This allows
26093f6ea84aSIra W. Snyder	  PCI hotplug to work on systems with the CNB20LE chipset which do
26103f6ea84aSIra W. Snyder	  not have ACPI.
26113f6ea84aSIra W. Snyder
261264a5fed6SBjorn Helgaas	  There's no public spec for this chipset, and this functionality
261364a5fed6SBjorn Helgaas	  is known to be incomplete.
261464a5fed6SBjorn Helgaas
261564a5fed6SBjorn Helgaas	  You should say N unless you know you need this.
261664a5fed6SBjorn Helgaas
2617e279b6c1SSam Ravnborgsource "drivers/pci/Kconfig"
2618e279b6c1SSam Ravnborg
26193a495511SWilliam Breathitt Grayconfig ISA_BUS
26203a495511SWilliam Breathitt Gray	bool "ISA-style bus support on modern systems" if EXPERT
26213a495511SWilliam Breathitt Gray	select ISA_BUS_API
26223a495511SWilliam Breathitt Gray	help
26233a495511SWilliam Breathitt Gray	  Enables ISA-style drivers on modern systems. This is necessary to
26243a495511SWilliam Breathitt Gray	  support PC/104 devices on X86_64 platforms.
26253a495511SWilliam Breathitt Gray
26263a495511SWilliam Breathitt Gray	  If unsure, say N.
26273a495511SWilliam Breathitt Gray
26281c00f016SDavid Rientjes# x86_64 have no ISA slots, but can have ISA-style DMA.
2629e279b6c1SSam Ravnborgconfig ISA_DMA_API
26301c00f016SDavid Rientjes	bool "ISA-style DMA support" if (X86_64 && EXPERT)
26311c00f016SDavid Rientjes	default y
26321c00f016SDavid Rientjes	help
26331c00f016SDavid Rientjes	  Enables ISA-style DMA support for devices requiring such controllers.
26341c00f016SDavid Rientjes	  If unsure, say Y.
2635e279b6c1SSam Ravnborg
263651e68d05SLinus Torvaldsif X86_32
263751e68d05SLinus Torvalds
2638e279b6c1SSam Ravnborgconfig ISA
2639e279b6c1SSam Ravnborg	bool "ISA support"
26408f9ca475SIngo Molnar	---help---
2641e279b6c1SSam Ravnborg	  Find out whether you have ISA slots on your motherboard.  ISA is the
2642e279b6c1SSam Ravnborg	  name of a bus system, i.e. the way the CPU talks to the other stuff
2643e279b6c1SSam Ravnborg	  inside your box.  Other bus systems are PCI, EISA, MicroChannel
2644e279b6c1SSam Ravnborg	  (MCA) or VESA.  ISA is an older system, now being displaced by PCI;
2645e279b6c1SSam Ravnborg	  newer boards don't support it.  If you have ISA, say Y, otherwise N.
2646e279b6c1SSam Ravnborg
2647e279b6c1SSam Ravnborgconfig EISA
2648e279b6c1SSam Ravnborg	bool "EISA support"
2649e279b6c1SSam Ravnborg	depends on ISA
2650e279b6c1SSam Ravnborg	---help---
2651e279b6c1SSam Ravnborg	  The Extended Industry Standard Architecture (EISA) bus was
2652e279b6c1SSam Ravnborg	  developed as an open alternative to the IBM MicroChannel bus.
2653e279b6c1SSam Ravnborg
2654e279b6c1SSam Ravnborg	  The EISA bus provided some of the features of the IBM MicroChannel
2655e279b6c1SSam Ravnborg	  bus while maintaining backward compatibility with cards made for
2656e279b6c1SSam Ravnborg	  the older ISA bus.  The EISA bus saw limited use between 1988 and
2657e279b6c1SSam Ravnborg	  1995 when it was made obsolete by the PCI bus.
2658e279b6c1SSam Ravnborg
2659e279b6c1SSam Ravnborg	  Say Y here if you are building a kernel for an EISA-based machine.
2660e279b6c1SSam Ravnborg
2661e279b6c1SSam Ravnborg	  Otherwise, say N.
2662e279b6c1SSam Ravnborg
2663e279b6c1SSam Ravnborgsource "drivers/eisa/Kconfig"
2664e279b6c1SSam Ravnborg
2665e279b6c1SSam Ravnborgconfig SCx200
2666e279b6c1SSam Ravnborg	tristate "NatSemi SCx200 support"
26678f9ca475SIngo Molnar	---help---
2668e279b6c1SSam Ravnborg	  This provides basic support for National Semiconductor's
2669e279b6c1SSam Ravnborg	  (now AMD's) Geode processors.  The driver probes for the
2670e279b6c1SSam Ravnborg	  PCI-IDs of several on-chip devices, so its a good dependency
2671e279b6c1SSam Ravnborg	  for other scx200_* drivers.
2672e279b6c1SSam Ravnborg
2673e279b6c1SSam Ravnborg	  If compiled as a module, the driver is named scx200.
2674e279b6c1SSam Ravnborg
2675e279b6c1SSam Ravnborgconfig SCx200HR_TIMER
2676e279b6c1SSam Ravnborg	tristate "NatSemi SCx200 27MHz High-Resolution Timer Support"
2677592913ecSJohn Stultz	depends on SCx200
2678e279b6c1SSam Ravnborg	default y
26798f9ca475SIngo Molnar	---help---
2680e279b6c1SSam Ravnborg	  This driver provides a clocksource built upon the on-chip
2681e279b6c1SSam Ravnborg	  27MHz high-resolution timer.  Its also a workaround for
2682e279b6c1SSam Ravnborg	  NSC Geode SC-1100's buggy TSC, which loses time when the
2683e279b6c1SSam Ravnborg	  processor goes idle (as is done by the scheduler).  The
2684e279b6c1SSam Ravnborg	  other workaround is idle=poll boot option.
2685e279b6c1SSam Ravnborg
26863ef0e1f8SAndres Salomonconfig OLPC
26873ef0e1f8SAndres Salomon	bool "One Laptop Per Child support"
268854008979SThomas Gleixner	depends on !X86_PAE
26893c554946SAndres Salomon	select GPIOLIB
2690dc3119e7SThomas Gleixner	select OF
269145bb1674SDaniel Drake	select OF_PROMTREE
2692b4e51854SGrant Likely	select IRQ_DOMAIN
26938f9ca475SIngo Molnar	---help---
26943ef0e1f8SAndres Salomon	  Add support for detecting the unique features of the OLPC
26953ef0e1f8SAndres Salomon	  XO hardware.
26963ef0e1f8SAndres Salomon
2697a3128588SDaniel Drakeconfig OLPC_XO1_PM
2698a3128588SDaniel Drake	bool "OLPC XO-1 Power Management"
269997c4cb71SDaniel Drake	depends on OLPC && MFD_CS5535 && PM_SLEEP
2700a3128588SDaniel Drake	select MFD_CORE
2701bf1ebf00SDaniel Drake	---help---
270297c4cb71SDaniel Drake	  Add support for poweroff and suspend of the OLPC XO-1 laptop.
2703bf1ebf00SDaniel Drake
2704cfee9597SDaniel Drakeconfig OLPC_XO1_RTC
2705cfee9597SDaniel Drake	bool "OLPC XO-1 Real Time Clock"
2706cfee9597SDaniel Drake	depends on OLPC_XO1_PM && RTC_DRV_CMOS
2707cfee9597SDaniel Drake	---help---
2708cfee9597SDaniel Drake	  Add support for the XO-1 real time clock, which can be used as a
2709cfee9597SDaniel Drake	  programmable wakeup source.
2710cfee9597SDaniel Drake
27117feda8e9SDaniel Drakeconfig OLPC_XO1_SCI
27127feda8e9SDaniel Drake	bool "OLPC XO-1 SCI extras"
2713d8d01a63SDaniel Drake	depends on OLPC && OLPC_XO1_PM
2714ed8e47feSRandy Dunlap	depends on INPUT=y
2715d8d01a63SDaniel Drake	select POWER_SUPPLY
27167feda8e9SDaniel Drake	select GPIO_CS5535
27177feda8e9SDaniel Drake	select MFD_CORE
27187feda8e9SDaniel Drake	---help---
27197feda8e9SDaniel Drake	  Add support for SCI-based features of the OLPC XO-1 laptop:
27207bc74b3dSDaniel Drake	   - EC-driven system wakeups
27217feda8e9SDaniel Drake	   - Power button
27227bc74b3dSDaniel Drake	   - Ebook switch
27232cf2baeaSDaniel Drake	   - Lid switch
2724e1040ac6SDaniel Drake	   - AC adapter status updates
2725e1040ac6SDaniel Drake	   - Battery status updates
27267feda8e9SDaniel Drake
2727a0f30f59SDaniel Drakeconfig OLPC_XO15_SCI
2728a0f30f59SDaniel Drake	bool "OLPC XO-1.5 SCI extras"
2729d8d01a63SDaniel Drake	depends on OLPC && ACPI
2730d8d01a63SDaniel Drake	select POWER_SUPPLY
2731a0f30f59SDaniel Drake	---help---
2732a0f30f59SDaniel Drake	  Add support for SCI-based features of the OLPC XO-1.5 laptop:
2733a0f30f59SDaniel Drake	   - EC-driven system wakeups
2734a0f30f59SDaniel Drake	   - AC adapter status updates
2735a0f30f59SDaniel Drake	   - Battery status updates
2736e279b6c1SSam Ravnborg
2737d4f3e350SEd Wildgooseconfig ALIX
2738d4f3e350SEd Wildgoose	bool "PCEngines ALIX System Support (LED setup)"
2739d4f3e350SEd Wildgoose	select GPIOLIB
2740d4f3e350SEd Wildgoose	---help---
2741d4f3e350SEd Wildgoose	  This option enables system support for the PCEngines ALIX.
2742d4f3e350SEd Wildgoose	  At present this just sets up LEDs for GPIO control on
2743d4f3e350SEd Wildgoose	  ALIX2/3/6 boards.  However, other system specific setup should
2744d4f3e350SEd Wildgoose	  get added here.
2745d4f3e350SEd Wildgoose
2746d4f3e350SEd Wildgoose	  Note: You must still enable the drivers for GPIO and LED support
2747d4f3e350SEd Wildgoose	  (GPIO_CS5535 & LEDS_GPIO) to actually use the LEDs
2748d4f3e350SEd Wildgoose
2749d4f3e350SEd Wildgoose	  Note: You have to set alix.force=1 for boards with Award BIOS.
2750d4f3e350SEd Wildgoose
2751da4e3302SPhilip Prindevilleconfig NET5501
2752da4e3302SPhilip Prindeville	bool "Soekris Engineering net5501 System Support (LEDS, GPIO, etc)"
2753da4e3302SPhilip Prindeville	select GPIOLIB
2754da4e3302SPhilip Prindeville	---help---
2755da4e3302SPhilip Prindeville	  This option enables system support for the Soekris Engineering net5501.
2756da4e3302SPhilip Prindeville
27573197059aSPhilip A. Prindevilleconfig GEOS
27583197059aSPhilip A. Prindeville	bool "Traverse Technologies GEOS System Support (LEDS, GPIO, etc)"
27593197059aSPhilip A. Prindeville	select GPIOLIB
27603197059aSPhilip A. Prindeville	depends on DMI
27613197059aSPhilip A. Prindeville	---help---
27623197059aSPhilip A. Prindeville	  This option enables system support for the Traverse Technologies GEOS.
27633197059aSPhilip A. Prindeville
27647d029125SVivien Didelotconfig TS5500
27657d029125SVivien Didelot	bool "Technologic Systems TS-5500 platform support"
27667d029125SVivien Didelot	depends on MELAN
27677d029125SVivien Didelot	select CHECK_SIGNATURE
27687d029125SVivien Didelot	select NEW_LEDS
27697d029125SVivien Didelot	select LEDS_CLASS
27707d029125SVivien Didelot	---help---
27717d029125SVivien Didelot	  This option enables system support for the Technologic Systems TS-5500.
27727d029125SVivien Didelot
2773e279b6c1SSam Ravnborgendif # X86_32
2774e279b6c1SSam Ravnborg
277523ac4ae8SAndreas Herrmannconfig AMD_NB
2776e279b6c1SSam Ravnborg	def_bool y
27770e152cd7SBorislav Petkov	depends on CPU_SUP_AMD && PCI
2778e279b6c1SSam Ravnborg
2779e279b6c1SSam Ravnborgsource "drivers/pcmcia/Kconfig"
2780e279b6c1SSam Ravnborg
2781388b78adSAlexandre Bounineconfig RAPIDIO
2782fdf90abcSAlexandre Bounine	tristate "RapidIO support"
2783388b78adSAlexandre Bounine	depends on PCI
2784388b78adSAlexandre Bounine	default n
2785388b78adSAlexandre Bounine	help
2786fdf90abcSAlexandre Bounine	  If enabled this option will include drivers and the core
2787388b78adSAlexandre Bounine	  infrastructure code to support RapidIO interconnect devices.
2788388b78adSAlexandre Bounine
2789388b78adSAlexandre Bouninesource "drivers/rapidio/Kconfig"
2790388b78adSAlexandre Bounine
2791e3263ab3SDavid Herrmannconfig X86_SYSFB
2792e3263ab3SDavid Herrmann	bool "Mark VGA/VBE/EFI FB as generic system framebuffer"
2793e3263ab3SDavid Herrmann	help
2794e3263ab3SDavid Herrmann	  Firmwares often provide initial graphics framebuffers so the BIOS,
2795e3263ab3SDavid Herrmann	  bootloader or kernel can show basic video-output during boot for
2796e3263ab3SDavid Herrmann	  user-guidance and debugging. Historically, x86 used the VESA BIOS
2797e3263ab3SDavid Herrmann	  Extensions and EFI-framebuffers for this, which are mostly limited
2798e3263ab3SDavid Herrmann	  to x86.
2799e3263ab3SDavid Herrmann	  This option, if enabled, marks VGA/VBE/EFI framebuffers as generic
2800e3263ab3SDavid Herrmann	  framebuffers so the new generic system-framebuffer drivers can be
2801e3263ab3SDavid Herrmann	  used on x86. If the framebuffer is not compatible with the generic
2802e3263ab3SDavid Herrmann	  modes, it is adverticed as fallback platform framebuffer so legacy
2803e3263ab3SDavid Herrmann	  drivers like efifb, vesafb and uvesafb can pick it up.
2804e3263ab3SDavid Herrmann	  If this option is not selected, all system framebuffers are always
2805e3263ab3SDavid Herrmann	  marked as fallback platform framebuffers as usual.
2806e3263ab3SDavid Herrmann
2807e3263ab3SDavid Herrmann	  Note: Legacy fbdev drivers, including vesafb, efifb, uvesafb, will
2808e3263ab3SDavid Herrmann	  not be able to pick up generic system framebuffers if this option
2809e3263ab3SDavid Herrmann	  is selected. You are highly encouraged to enable simplefb as
2810e3263ab3SDavid Herrmann	  replacement if you select this option. simplefb can correctly deal
2811e3263ab3SDavid Herrmann	  with generic system framebuffers. But you should still keep vesafb
2812e3263ab3SDavid Herrmann	  and others enabled as fallback if a system framebuffer is
2813e3263ab3SDavid Herrmann	  incompatible with simplefb.
2814e3263ab3SDavid Herrmann
2815e3263ab3SDavid Herrmann	  If unsure, say Y.
2816e3263ab3SDavid Herrmann
2817e279b6c1SSam Ravnborgendmenu
2818e279b6c1SSam Ravnborg
2819e279b6c1SSam Ravnborg
2820e279b6c1SSam Ravnborgmenu "Executable file formats / Emulations"
2821e279b6c1SSam Ravnborg
2822e279b6c1SSam Ravnborgsource "fs/Kconfig.binfmt"
2823e279b6c1SSam Ravnborg
2824e279b6c1SSam Ravnborgconfig IA32_EMULATION
2825e279b6c1SSam Ravnborg	bool "IA32 Emulation"
2826e279b6c1SSam Ravnborg	depends on X86_64
282739f88911SIngo Molnar	select ARCH_WANT_OLD_COMPAT_IPC
2828d1603990SRandy Dunlap	select BINFMT_ELF
2829a97f52e6SRoland McGrath	select COMPAT_BINFMT_ELF
283039f88911SIngo Molnar	select COMPAT_OLD_SIGACTION
28318f9ca475SIngo Molnar	---help---
28325fd92e65SH. J. Lu	  Include code to run legacy 32-bit programs under a
28335fd92e65SH. J. Lu	  64-bit kernel. You should likely turn this on, unless you're
28345fd92e65SH. J. Lu	  100% sure that you don't have any 32-bit programs left.
2835e279b6c1SSam Ravnborg
2836e279b6c1SSam Ravnborgconfig IA32_AOUT
2837e279b6c1SSam Ravnborg	tristate "IA32 a.out support"
28386b213e1bSDavid Woodhouse	depends on IA32_EMULATION
28398f9ca475SIngo Molnar	---help---
2840e279b6c1SSam Ravnborg	  Support old a.out binaries in the 32bit emulation.
2841e279b6c1SSam Ravnborg
28420bf62763SH. Peter Anvinconfig X86_X32
28436ea30386SKees Cook	bool "x32 ABI for 64-bit mode"
28449b54050bSBrian Gerst	depends on X86_64
28455fd92e65SH. J. Lu	---help---
28465fd92e65SH. J. Lu	  Include code to run binaries for the x32 native 32-bit ABI
28475fd92e65SH. J. Lu	  for 64-bit processors.  An x32 process gets access to the
28485fd92e65SH. J. Lu	  full 64-bit register file and wide data path while leaving
28495fd92e65SH. J. Lu	  pointers at 32 bits for smaller memory footprint.
28505fd92e65SH. J. Lu
28515fd92e65SH. J. Lu	  You will need a recent binutils (2.22 or later) with
28525fd92e65SH. J. Lu	  elf32_x86_64 support enabled to compile a kernel with this
28535fd92e65SH. J. Lu	  option set.
28545fd92e65SH. J. Lu
2855953fee1dSIngo Molnarconfig COMPAT_32
2856953fee1dSIngo Molnar	def_bool y
2857953fee1dSIngo Molnar	depends on IA32_EMULATION || X86_32
2858953fee1dSIngo Molnar	select HAVE_UID16
2859953fee1dSIngo Molnar	select OLD_SIGSUSPEND3
2860953fee1dSIngo Molnar
2861e279b6c1SSam Ravnborgconfig COMPAT
28623c2362e6SHarvey Harrison	def_bool y
28630bf62763SH. Peter Anvin	depends on IA32_EMULATION || X86_X32
2864e279b6c1SSam Ravnborg
28653120e25eSJan Beulichif COMPAT
2866e279b6c1SSam Ravnborgconfig COMPAT_FOR_U64_ALIGNMENT
28673120e25eSJan Beulich	def_bool y
2868e279b6c1SSam Ravnborg
2869e279b6c1SSam Ravnborgconfig SYSVIPC_COMPAT
28703c2362e6SHarvey Harrison	def_bool y
28713120e25eSJan Beulich	depends on SYSVIPC
28723120e25eSJan Beulichendif
2873ee009e4aSDavid Howells
2874e279b6c1SSam Ravnborgendmenu
2875e279b6c1SSam Ravnborg
2876e279b6c1SSam Ravnborg
2877e5beae16SKeith Packardconfig HAVE_ATOMIC_IOMAP
2878e5beae16SKeith Packard	def_bool y
2879e5beae16SKeith Packard	depends on X86_32
2880e5beae16SKeith Packard
28814692d77fSAlessandro Rubiniconfig X86_DEV_DMA_OPS
28824692d77fSAlessandro Rubini	bool
288383125a3aSAlessandro Rubini	depends on X86_64 || STA2X11
28844692d77fSAlessandro Rubini
2885f7219a53SAlessandro Rubiniconfig X86_DMA_REMAP
2886f7219a53SAlessandro Rubini	bool
288783125a3aSAlessandro Rubini	depends on STA2X11
2888f7219a53SAlessandro Rubini
2889e585513bSKirill A. Shutemovconfig HAVE_GENERIC_GUP
2890e585513bSKirill A. Shutemov	def_bool y
2891e585513bSKirill A. Shutemov
2892e279b6c1SSam Ravnborgsource "net/Kconfig"
2893e279b6c1SSam Ravnborg
2894e279b6c1SSam Ravnborgsource "drivers/Kconfig"
2895e279b6c1SSam Ravnborg
2896e279b6c1SSam Ravnborgsource "drivers/firmware/Kconfig"
2897e279b6c1SSam Ravnborg
2898e279b6c1SSam Ravnborgsource "fs/Kconfig"
2899e279b6c1SSam Ravnborg
2900e279b6c1SSam Ravnborgsource "arch/x86/Kconfig.debug"
2901e279b6c1SSam Ravnborg
2902e279b6c1SSam Ravnborgsource "security/Kconfig"
2903e279b6c1SSam Ravnborg
2904e279b6c1SSam Ravnborgsource "crypto/Kconfig"
2905e279b6c1SSam Ravnborg
2906edf88417SAvi Kivitysource "arch/x86/kvm/Kconfig"
2907edf88417SAvi Kivity
2908e279b6c1SSam Ravnborgsource "lib/Kconfig"
2909