xref: /linux/arch/x86/Kconfig (revision fec777c385b6376048fc4b08f039366545b335cd)
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
57ea8c64acSChristoph Hellwig	select ARCH_HAS_PHYS_TO_DMA
5810bcc80eSMathieu Desnoyers	select ARCH_HAS_MEMBARRIER_SYNC_CORE
59c763ea26SIngo Molnar	select ARCH_HAS_PMEM_API		if X86_64
6039208aa7SKees Cook	select ARCH_HAS_REFCOUNT
610aed55afSDan Williams	select ARCH_HAS_UACCESS_FLUSHCACHE	if X86_64
62d2852a22SDaniel Borkmann	select ARCH_HAS_SET_MEMORY
636471b825SIngo Molnar	select ARCH_HAS_SG_CHAIN
64ad21fc4fSLaura Abbott	select ARCH_HAS_STRICT_KERNEL_RWX
65ad21fc4fSLaura Abbott	select ARCH_HAS_STRICT_MODULE_RWX
66ac1ab12aSMathieu Desnoyers	select ARCH_HAS_SYNC_CORE_BEFORE_USERMODE
67c6d30853SAndrey Ryabinin	select ARCH_HAS_UBSAN_SANITIZE_ALL
6865f7d049SOliver O'Halloran	select ARCH_HAS_ZONE_DEVICE		if X86_64
696471b825SIngo Molnar	select ARCH_HAVE_NMI_SAFE_CMPXCHG
706471b825SIngo Molnar	select ARCH_MIGHT_HAVE_ACPI_PDC		if ACPI
7177fbbc81SMark Salter	select ARCH_MIGHT_HAVE_PC_PARPORT
725e2c18c0SMark Salter	select ARCH_MIGHT_HAVE_PC_SERIO
736471b825SIngo Molnar	select ARCH_SUPPORTS_ATOMIC_RMW
746471b825SIngo Molnar	select ARCH_SUPPORTS_NUMA_BALANCING	if X86_64
756471b825SIngo Molnar	select ARCH_USE_BUILTIN_BSWAP
766471b825SIngo Molnar	select ARCH_USE_QUEUED_RWLOCKS
776471b825SIngo Molnar	select ARCH_USE_QUEUED_SPINLOCKS
78ce4a4e56SAndy Lutomirski	select ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH
79c763ea26SIngo Molnar	select ARCH_WANTS_DYNAMIC_TASK_STRUCT
8038d8b4e6SHuang Ying	select ARCH_WANTS_THP_SWAP		if X86_64
816471b825SIngo Molnar	select BUILDTIME_EXTABLE_SORT
826471b825SIngo Molnar	select CLKEVT_I8253
836471b825SIngo Molnar	select CLOCKSOURCE_VALIDATE_LAST_CYCLE
846471b825SIngo Molnar	select CLOCKSOURCE_WATCHDOG
856471b825SIngo Molnar	select DCACHE_WORD_ACCESS
86*fec777c3SChristoph Hellwig	select DMA_DIRECT_OPS
8745471cd9SLinus Torvalds	select EDAC_ATOMIC_SCRUB
8845471cd9SLinus Torvalds	select EDAC_SUPPORT
896471b825SIngo Molnar	select GENERIC_CLOCKEVENTS
906471b825SIngo Molnar	select GENERIC_CLOCKEVENTS_BROADCAST	if X86_64 || (X86_32 && X86_LOCAL_APIC)
916471b825SIngo Molnar	select GENERIC_CLOCKEVENTS_MIN_ADJUST
926471b825SIngo Molnar	select GENERIC_CMOS_UPDATE
936471b825SIngo Molnar	select GENERIC_CPU_AUTOPROBE
9461dc0f55SThomas Gleixner	select GENERIC_CPU_VULNERABILITIES
956471b825SIngo Molnar	select GENERIC_EARLY_IOREMAP
966471b825SIngo Molnar	select GENERIC_FIND_FIRST_BIT
976471b825SIngo Molnar	select GENERIC_IOMAP
98c7d6c9ddSThomas Gleixner	select GENERIC_IRQ_EFFECTIVE_AFF_MASK	if SMP
990fa115daSThomas Gleixner	select GENERIC_IRQ_MATRIX_ALLOCATOR	if X86_LOCAL_APIC
100ad7a929fSThomas Gleixner	select GENERIC_IRQ_MIGRATION		if SMP
1016471b825SIngo Molnar	select GENERIC_IRQ_PROBE
102c201c917SThomas Gleixner	select GENERIC_IRQ_RESERVATION_MODE
1036471b825SIngo Molnar	select GENERIC_IRQ_SHOW
1046471b825SIngo Molnar	select GENERIC_PENDING_IRQ		if SMP
1056471b825SIngo Molnar	select GENERIC_SMP_IDLE_THREAD
1066471b825SIngo Molnar	select GENERIC_STRNCPY_FROM_USER
1076471b825SIngo Molnar	select GENERIC_STRNLEN_USER
1086471b825SIngo Molnar	select GENERIC_TIME_VSYSCALL
1097edaeb68SThomas Gleixner	select HARDLOCKUP_CHECK_TIMESTAMP	if X86_64
1106471b825SIngo Molnar	select HAVE_ACPI_APEI			if ACPI
1116471b825SIngo Molnar	select HAVE_ACPI_APEI_NMI		if ACPI
1126471b825SIngo Molnar	select HAVE_ALIGNED_STRUCT_PAGE		if SLUB
1136471b825SIngo Molnar	select HAVE_ARCH_AUDITSYSCALL
1146471b825SIngo Molnar	select HAVE_ARCH_HUGE_VMAP		if X86_64 || X86_PAE
1156471b825SIngo Molnar	select HAVE_ARCH_JUMP_LABEL
116d17a1d97SAndrey Ryabinin	select HAVE_ARCH_KASAN			if X86_64
1176471b825SIngo Molnar	select HAVE_ARCH_KGDB
1189e08f57dSDaniel Cashman	select HAVE_ARCH_MMAP_RND_BITS		if MMU
1199e08f57dSDaniel Cashman	select HAVE_ARCH_MMAP_RND_COMPAT_BITS	if MMU && COMPAT
1201b028f78SDmitry Safonov	select HAVE_ARCH_COMPAT_MMAP_BASES	if MMU && COMPAT
1216471b825SIngo Molnar	select HAVE_ARCH_SECCOMP_FILTER
122f7d83c1cSKees Cook	select HAVE_ARCH_THREAD_STRUCT_WHITELIST
1236471b825SIngo Molnar	select HAVE_ARCH_TRACEHOOK
1246471b825SIngo Molnar	select HAVE_ARCH_TRANSPARENT_HUGEPAGE
125a00cc7d9SMatthew Wilcox	select HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD if X86_64
126e37e43a4SAndy Lutomirski	select HAVE_ARCH_VMAP_STACK		if X86_64
127c763ea26SIngo Molnar	select HAVE_ARCH_WITHIN_STACK_FRAMES
1286471b825SIngo Molnar	select HAVE_CC_STACKPROTECTOR
1296471b825SIngo Molnar	select HAVE_CMPXCHG_DOUBLE
1306471b825SIngo Molnar	select HAVE_CMPXCHG_LOCAL
1316471b825SIngo Molnar	select HAVE_CONTEXT_TRACKING		if X86_64
132c1bd55f9SJosh Triplett	select HAVE_COPY_THREAD_TLS
1336471b825SIngo Molnar	select HAVE_C_RECORDMCOUNT
1346471b825SIngo Molnar	select HAVE_DEBUG_KMEMLEAK
1356471b825SIngo Molnar	select HAVE_DEBUG_STACKOVERFLOW
1366471b825SIngo Molnar	select HAVE_DMA_API_DEBUG
1379c5a3621SAkinobu Mita	select HAVE_DMA_CONTIGUOUS
138677aa9f7SSteven Rostedt	select HAVE_DYNAMIC_FTRACE
13906aeaaeaSMasami Hiramatsu	select HAVE_DYNAMIC_FTRACE_WITH_REGS
140c763ea26SIngo Molnar	select HAVE_EBPF_JIT			if X86_64
14158340a07SJohannes Berg	select HAVE_EFFICIENT_UNALIGNED_ACCESS
1425f56a5dfSJiri Slaby	select HAVE_EXIT_THREAD
143644e0e8dSSteven Rostedt (VMware)	select HAVE_FENTRY			if X86_64 || DYNAMIC_FTRACE
1446471b825SIngo Molnar	select HAVE_FTRACE_MCOUNT_RECORD
1456471b825SIngo Molnar	select HAVE_FUNCTION_GRAPH_TRACER
1466471b825SIngo Molnar	select HAVE_FUNCTION_TRACER
1476b90bd4bSEmese Revfy	select HAVE_GCC_PLUGINS
1480067f129SK.Prasad	select HAVE_HW_BREAKPOINT
1496471b825SIngo Molnar	select HAVE_IDE
1506471b825SIngo Molnar	select HAVE_IOREMAP_PROT
1516471b825SIngo Molnar	select HAVE_IRQ_EXIT_ON_IRQ_STACK	if X86_64
1526471b825SIngo Molnar	select HAVE_IRQ_TIME_ACCOUNTING
1536471b825SIngo Molnar	select HAVE_KERNEL_BZIP2
1546471b825SIngo Molnar	select HAVE_KERNEL_GZIP
1556471b825SIngo Molnar	select HAVE_KERNEL_LZ4
1566471b825SIngo Molnar	select HAVE_KERNEL_LZMA
1576471b825SIngo Molnar	select HAVE_KERNEL_LZO
1586471b825SIngo Molnar	select HAVE_KERNEL_XZ
1596471b825SIngo Molnar	select HAVE_KPROBES
1606471b825SIngo Molnar	select HAVE_KPROBES_ON_FTRACE
161540adea3SMasami Hiramatsu	select HAVE_FUNCTION_ERROR_INJECTION
1626471b825SIngo Molnar	select HAVE_KRETPROBES
1636471b825SIngo Molnar	select HAVE_KVM
1646471b825SIngo Molnar	select HAVE_LIVEPATCH			if X86_64
1656471b825SIngo Molnar	select HAVE_MEMBLOCK
1666471b825SIngo Molnar	select HAVE_MEMBLOCK_NODE_MAP
1670102752eSFrederic Weisbecker	select HAVE_MIXED_BREAKPOINTS_REGS
168ee9f8fceSJosh Poimboeuf	select HAVE_MOD_ARCH_SPECIFIC
16942a0bb3fSPetr Mladek	select HAVE_NMI
1706471b825SIngo Molnar	select HAVE_OPROFILE
1716471b825SIngo Molnar	select HAVE_OPTPROBES
1726471b825SIngo Molnar	select HAVE_PCSPKR_PLATFORM
1736471b825SIngo Molnar	select HAVE_PERF_EVENTS
174c01d4323SFrederic Weisbecker	select HAVE_PERF_EVENTS_NMI
17592e5aae4SNicholas Piggin	select HAVE_HARDLOCKUP_DETECTOR_PERF	if PERF_EVENTS && HAVE_PERF_EVENTS_NMI
176c5e63197SJiri Olsa	select HAVE_PERF_REGS
177c5ebcedbSJiri Olsa	select HAVE_PERF_USER_STACK_DUMP
1789e52fc2bSVitaly Kuznetsov	select HAVE_RCU_TABLE_FREE
1796471b825SIngo Molnar	select HAVE_REGS_AND_STACK_ACCESS_API
18011af8474SJosh Poimboeuf	select HAVE_RELIABLE_STACKTRACE		if X86_64 && UNWINDER_FRAME_POINTER && STACK_VALIDATION
181c763ea26SIngo Molnar	select HAVE_STACK_VALIDATION		if X86_64
1826471b825SIngo Molnar	select HAVE_SYSCALL_TRACEPOINTS
1836471b825SIngo Molnar	select HAVE_UNSTABLE_SCHED_CLOCK
1847c68af6eSAvi Kivity	select HAVE_USER_RETURN_NOTIFIER
185c0185808SThomas Gleixner	select IRQ_FORCED_THREADING
186df65c1bcSThomas Gleixner	select PCI_LOCKLESS_CONFIG
1876471b825SIngo Molnar	select PERF_EVENTS
1883195ef59SPrarit Bhargava	select RTC_LIB
189d6faca40SArnd Bergmann	select RTC_MC146818_LIB
1906471b825SIngo Molnar	select SPARSE_IRQ
19183fe27eaSPranith Kumar	select SRCU
1926471b825SIngo Molnar	select SYSCTL_EXCEPTION_TRACE
19315f4eae7SAndy Lutomirski	select THREAD_INFO_IN_TASK
1946471b825SIngo Molnar	select USER_STACKTRACE_SUPPORT
1956471b825SIngo Molnar	select VIRT_TO_BUS
1966471b825SIngo Molnar	select X86_FEATURE_NAMES		if PROC_FS
1977d8330a5SBalbir Singh
198ba7e4d13SIngo Molnarconfig INSTRUCTION_DECODER
1993120e25eSJan Beulich	def_bool y
2003120e25eSJan Beulich	depends on KPROBES || PERF_EVENTS || UPROBES
201ba7e4d13SIngo Molnar
20251b26adaSLinus Torvaldsconfig OUTPUT_FORMAT
20351b26adaSLinus Torvalds	string
20451b26adaSLinus Torvalds	default "elf32-i386" if X86_32
20551b26adaSLinus Torvalds	default "elf64-x86-64" if X86_64
20651b26adaSLinus Torvalds
20773531905SSam Ravnborgconfig ARCH_DEFCONFIG
208b9b39bfbSSam Ravnborg	string
20973531905SSam Ravnborg	default "arch/x86/configs/i386_defconfig" if X86_32
21073531905SSam Ravnborg	default "arch/x86/configs/x86_64_defconfig" if X86_64
211b9b39bfbSSam Ravnborg
2128d5fffb9SSam Ravnborgconfig LOCKDEP_SUPPORT
2133c2362e6SHarvey Harrison	def_bool y
2148d5fffb9SSam Ravnborg
2158d5fffb9SSam Ravnborgconfig STACKTRACE_SUPPORT
2163c2362e6SHarvey Harrison	def_bool y
2178d5fffb9SSam Ravnborg
2188d5fffb9SSam Ravnborgconfig MMU
2193c2362e6SHarvey Harrison	def_bool y
2208d5fffb9SSam Ravnborg
2219e08f57dSDaniel Cashmanconfig ARCH_MMAP_RND_BITS_MIN
2229e08f57dSDaniel Cashman	default 28 if 64BIT
2239e08f57dSDaniel Cashman	default 8
2249e08f57dSDaniel Cashman
2259e08f57dSDaniel Cashmanconfig ARCH_MMAP_RND_BITS_MAX
2269e08f57dSDaniel Cashman	default 32 if 64BIT
2279e08f57dSDaniel Cashman	default 16
2289e08f57dSDaniel Cashman
2299e08f57dSDaniel Cashmanconfig ARCH_MMAP_RND_COMPAT_BITS_MIN
2309e08f57dSDaniel Cashman	default 8
2319e08f57dSDaniel Cashman
2329e08f57dSDaniel Cashmanconfig ARCH_MMAP_RND_COMPAT_BITS_MAX
2339e08f57dSDaniel Cashman	default 16
2349e08f57dSDaniel Cashman
2358d5fffb9SSam Ravnborgconfig SBUS
2368d5fffb9SSam Ravnborg	bool
2378d5fffb9SSam Ravnborg
2383bc4e459SFUJITA Tomonoriconfig NEED_DMA_MAP_STATE
2393120e25eSJan Beulich	def_bool y
240a6dfa128SKonrad Rzeszutek Wilk	depends on X86_64 || INTEL_IOMMU || DMA_API_DEBUG || SWIOTLB
2413bc4e459SFUJITA Tomonori
24218e98307SFUJITA Tomonoriconfig NEED_SG_DMA_LENGTH
2434a14d84eSAndrew Morton	def_bool y
24418e98307SFUJITA Tomonori
2458d5fffb9SSam Ravnborgconfig GENERIC_ISA_DMA
2463120e25eSJan Beulich	def_bool y
2473120e25eSJan Beulich	depends on ISA_DMA_API
2488d5fffb9SSam Ravnborg
2498d5fffb9SSam Ravnborgconfig GENERIC_BUG
2503c2362e6SHarvey Harrison	def_bool y
2518d5fffb9SSam Ravnborg	depends on BUG
252b93a531eSJan Beulich	select GENERIC_BUG_RELATIVE_POINTERS if X86_64
253b93a531eSJan Beulich
254b93a531eSJan Beulichconfig GENERIC_BUG_RELATIVE_POINTERS
255b93a531eSJan Beulich	bool
2568d5fffb9SSam Ravnborg
2578d5fffb9SSam Ravnborgconfig GENERIC_HWEIGHT
2583c2362e6SHarvey Harrison	def_bool y
2598d5fffb9SSam Ravnborg
2608d5fffb9SSam Ravnborgconfig ARCH_MAY_HAVE_PC_FDC
2613120e25eSJan Beulich	def_bool y
2623120e25eSJan Beulich	depends on ISA_DMA_API
2638d5fffb9SSam Ravnborg
2641032c0baSSam Ravnborgconfig RWSEM_XCHGADD_ALGORITHM
2653120e25eSJan Beulich	def_bool y
2661032c0baSSam Ravnborg
2671032c0baSSam Ravnborgconfig GENERIC_CALIBRATE_DELAY
2681032c0baSSam Ravnborg	def_bool y
2691032c0baSSam Ravnborg
2709a0b8415Svenkatesh.pallipadi@intel.comconfig ARCH_HAS_CPU_RELAX
2719a0b8415Svenkatesh.pallipadi@intel.com	def_bool y
2728d5fffb9SSam Ravnborg
2731b27d05bSPekka Enbergconfig ARCH_HAS_CACHE_LINE_SIZE
2741b27d05bSPekka Enberg	def_bool y
2751b27d05bSPekka Enberg
276dd5af90aSMike Travisconfig HAVE_SETUP_PER_CPU_AREA
27789c9c4c5SBrian Gerst	def_bool y
278b32ef636Stravis@sgi.com
27908fc4580STejun Heoconfig NEED_PER_CPU_EMBED_FIRST_CHUNK
28008fc4580STejun Heo	def_bool y
28108fc4580STejun Heo
28208fc4580STejun Heoconfig NEED_PER_CPU_PAGE_FIRST_CHUNK
28311124411STejun Heo	def_bool y
28411124411STejun Heo
285801e4062SJohannes Bergconfig ARCH_HIBERNATION_POSSIBLE
286801e4062SJohannes Berg	def_bool y
287801e4062SJohannes Berg
288f4cb5700SJohannes Bergconfig ARCH_SUSPEND_POSSIBLE
289f4cb5700SJohannes Berg	def_bool y
290f4cb5700SJohannes Berg
291cfe28c5dSSteve Capperconfig ARCH_WANT_HUGE_PMD_SHARE
292cfe28c5dSSteve Capper	def_bool y
293cfe28c5dSSteve Capper
29453313b2cSSteve Capperconfig ARCH_WANT_GENERAL_HUGETLB
29553313b2cSSteve Capper	def_bool y
29653313b2cSSteve Capper
2978d5fffb9SSam Ravnborgconfig ZONE_DMA32
298e0fd24a3SJan Beulich	def_bool y if X86_64
2998d5fffb9SSam Ravnborg
3008d5fffb9SSam Ravnborgconfig AUDIT_ARCH
301e0fd24a3SJan Beulich	def_bool y if X86_64
3028d5fffb9SSam Ravnborg
303765c68bdSIngo Molnarconfig ARCH_SUPPORTS_OPTIMIZED_INLINING
304765c68bdSIngo Molnar	def_bool y
305765c68bdSIngo Molnar
3066a11f75bSAkinobu Mitaconfig ARCH_SUPPORTS_DEBUG_PAGEALLOC
3076a11f75bSAkinobu Mita	def_bool y
3086a11f75bSAkinobu Mita
309d6f2d75aSAndrey Ryabininconfig KASAN_SHADOW_OFFSET
310d6f2d75aSAndrey Ryabinin	hex
311d6f2d75aSAndrey Ryabinin	depends on KASAN
312d6f2d75aSAndrey Ryabinin	default 0xdffffc0000000000
313d6f2d75aSAndrey Ryabinin
31469575d38SShane Wangconfig HAVE_INTEL_TXT
31569575d38SShane Wang	def_bool y
3166ea30386SKees Cook	depends on INTEL_IOMMU && ACPI
31769575d38SShane Wang
3186b0c3d44SSam Ravnborgconfig X86_32_SMP
3196b0c3d44SSam Ravnborg	def_bool y
3206b0c3d44SSam Ravnborg	depends on X86_32 && SMP
3216b0c3d44SSam Ravnborg
3226b0c3d44SSam Ravnborgconfig X86_64_SMP
3236b0c3d44SSam Ravnborg	def_bool y
3246b0c3d44SSam Ravnborg	depends on X86_64 && SMP
3256b0c3d44SSam Ravnborg
326ccbeed3aSTejun Heoconfig X86_32_LAZY_GS
327ccbeed3aSTejun Heo	def_bool y
3282bc2f688SKees Cook	depends on X86_32 && CC_STACKPROTECTOR_NONE
329ccbeed3aSTejun Heo
3302b144498SSrikar Dronamrajuconfig ARCH_SUPPORTS_UPROBES
3312b144498SSrikar Dronamraju	def_bool y
3322b144498SSrikar Dronamraju
333d20642f0SRob Herringconfig FIX_EARLYCON_MEM
334d20642f0SRob Herring	def_bool y
335d20642f0SRob Herring
33698233368SKirill A. Shutemovconfig PGTABLE_LEVELS
33798233368SKirill A. Shutemov	int
33877ef56e4SKirill A. Shutemov	default 5 if X86_5LEVEL
33998233368SKirill A. Shutemov	default 4 if X86_64
34098233368SKirill A. Shutemov	default 3 if X86_PAE
34198233368SKirill A. Shutemov	default 2
34298233368SKirill A. Shutemov
343506f1d07SSam Ravnborgsource "init/Kconfig"
344dc52ddc0SMatt Helsleysource "kernel/Kconfig.freezer"
3458d5fffb9SSam Ravnborg
346506f1d07SSam Ravnborgmenu "Processor type and features"
347506f1d07SSam Ravnborg
3485ee71535SRandy Dunlapconfig ZONE_DMA
3495ee71535SRandy Dunlap	bool "DMA memory allocation support" if EXPERT
3505ee71535SRandy Dunlap	default y
3515ee71535SRandy Dunlap	help
3525ee71535SRandy Dunlap	  DMA memory allocation support allows devices with less than 32-bit
3535ee71535SRandy Dunlap	  addressing to allocate within the first 16MB of address space.
3545ee71535SRandy Dunlap	  Disable if no such devices will be used.
3555ee71535SRandy Dunlap
3565ee71535SRandy Dunlap	  If unsure, say Y.
3575ee71535SRandy Dunlap
358506f1d07SSam Ravnborgconfig SMP
359506f1d07SSam Ravnborg	bool "Symmetric multi-processing support"
360506f1d07SSam Ravnborg	---help---
361506f1d07SSam Ravnborg	  This enables support for systems with more than one CPU. If you have
3624a474157SRobert Graffham	  a system with only one CPU, say N. If you have a system with more
3634a474157SRobert Graffham	  than one CPU, say Y.
364506f1d07SSam Ravnborg
3654a474157SRobert Graffham	  If you say N here, the kernel will run on uni- and multiprocessor
366506f1d07SSam Ravnborg	  machines, but will use only one CPU of a multiprocessor machine. If
367506f1d07SSam Ravnborg	  you say Y here, the kernel will run on many, but not all,
3684a474157SRobert Graffham	  uniprocessor machines. On a uniprocessor machine, the kernel
369506f1d07SSam Ravnborg	  will run faster if you say N here.
370506f1d07SSam Ravnborg
371506f1d07SSam Ravnborg	  Note that if you say Y here and choose architecture "586" or
372506f1d07SSam Ravnborg	  "Pentium" under "Processor family", the kernel will not work on 486
373506f1d07SSam Ravnborg	  architectures. Similarly, multiprocessor kernels for the "PPro"
374506f1d07SSam Ravnborg	  architecture may not work on all Pentium based boards.
375506f1d07SSam Ravnborg
376506f1d07SSam Ravnborg	  People using multiprocessor machines who say Y here should also say
377506f1d07SSam Ravnborg	  Y to "Enhanced Real Time Clock Support", below. The "Advanced Power
378506f1d07SSam Ravnborg	  Management" code will be disabled if you say Y here.
379506f1d07SSam Ravnborg
380395cf969SPaul Bolle	  See also <file:Documentation/x86/i386/IO-APIC.txt>,
381c9525a3fSBenjamin Peterson	  <file:Documentation/lockup-watchdogs.txt> and the SMP-HOWTO available at
382506f1d07SSam Ravnborg	  <http://www.tldp.org/docs.html#howto>.
383506f1d07SSam Ravnborg
384506f1d07SSam Ravnborg	  If you don't know what to do here, say N.
385506f1d07SSam Ravnborg
3869def39beSJosh Triplettconfig X86_FEATURE_NAMES
3879def39beSJosh Triplett	bool "Processor feature human-readable names" if EMBEDDED
3889def39beSJosh Triplett	default y
3899def39beSJosh Triplett	---help---
3909def39beSJosh Triplett	  This option compiles in a table of x86 feature bits and corresponding
3919def39beSJosh Triplett	  names.  This is required to support /proc/cpuinfo and a few kernel
3929def39beSJosh Triplett	  messages.  You can disable this to save space, at the expense of
3939def39beSJosh Triplett	  making those few kernel messages show numeric feature bits instead.
3949def39beSJosh Triplett
3959def39beSJosh Triplett	  If in doubt, say Y.
3969def39beSJosh Triplett
3976e1315feSBorislav Petkovconfig X86_FAST_FEATURE_TESTS
3986e1315feSBorislav Petkov	bool "Fast CPU feature tests" if EMBEDDED
3996e1315feSBorislav Petkov	default y
4006e1315feSBorislav Petkov	---help---
4016e1315feSBorislav Petkov	  Some fast-paths in the kernel depend on the capabilities of the CPU.
4026e1315feSBorislav Petkov	  Say Y here for the kernel to patch in the appropriate code at runtime
4036e1315feSBorislav Petkov	  based on the capabilities of the CPU. The infrastructure for patching
4046e1315feSBorislav Petkov	  code at runtime takes up some additional space; space-constrained
4056e1315feSBorislav Petkov	  embedded systems may wish to say N here to produce smaller, slightly
4066e1315feSBorislav Petkov	  slower code.
4076e1315feSBorislav Petkov
40806cd9a7dSYinghai Luconfig X86_X2APIC
40906cd9a7dSYinghai Lu	bool "Support x2apic"
41019e3d60dSJan Kiszka	depends on X86_LOCAL_APIC && X86_64 && (IRQ_REMAP || HYPERVISOR_GUEST)
41106cd9a7dSYinghai Lu	---help---
41206cd9a7dSYinghai Lu	  This enables x2apic support on CPUs that have this feature.
41306cd9a7dSYinghai Lu
41406cd9a7dSYinghai Lu	  This allows 32-bit apic IDs (so it can support very large systems),
41506cd9a7dSYinghai Lu	  and accesses the local apic via MSRs not via mmio.
41606cd9a7dSYinghai Lu
41706cd9a7dSYinghai Lu	  If you don't know what to do here, say N.
41806cd9a7dSYinghai Lu
4196695c85bSYinghai Luconfig X86_MPPARSE
4206e87f9b7SBin Gao	bool "Enable MPS table" if ACPI || SFI
4217a527688SJan Beulich	default y
4225ab74722SIngo Molnar	depends on X86_LOCAL_APIC
4238f9ca475SIngo Molnar	---help---
4246695c85bSYinghai Lu	  For old smp systems that do not have proper acpi support. Newer systems
4256695c85bSYinghai Lu	  (esp with 64bit cpus) with acpi support, MADT and DSDT will override it
4266695c85bSYinghai Lu
427ddd70cf9SJun Nakajimaconfig GOLDFISH
428ddd70cf9SJun Nakajima       def_bool y
429ddd70cf9SJun Nakajima       depends on X86_GOLDFISH
430ddd70cf9SJun Nakajima
43176b04384SDavid Woodhouseconfig RETPOLINE
43276b04384SDavid Woodhouse	bool "Avoid speculative indirect branches in kernel"
43376b04384SDavid Woodhouse	default y
434d5028ba8SPeter Zijlstra	select STACK_VALIDATION if HAVE_STACK_VALIDATION
43576b04384SDavid Woodhouse	help
43676b04384SDavid Woodhouse	  Compile kernel with the retpoline compiler options to guard against
43776b04384SDavid Woodhouse	  kernel-to-user data leaks by avoiding speculative indirect
43876b04384SDavid Woodhouse	  branches. Requires a compiler with -mindirect-branch=thunk-extern
43976b04384SDavid Woodhouse	  support for full protection. The kernel may run slower.
44076b04384SDavid Woodhouse
44176b04384SDavid Woodhouse	  Without compiler support, at least indirect branches in assembler
44276b04384SDavid Woodhouse	  code are eliminated. Since this includes the syscall entry path,
44376b04384SDavid Woodhouse	  it is not entirely pointless.
44476b04384SDavid Woodhouse
445f01d7d51SVikas Shivappaconfig INTEL_RDT
446f01d7d51SVikas Shivappa	bool "Intel Resource Director Technology support"
44778e99b4aSFenghua Yu	default n
44878e99b4aSFenghua Yu	depends on X86 && CPU_SUP_INTEL
44959fe5a77SThomas Gleixner	select KERNFS
45078e99b4aSFenghua Yu	help
451f01d7d51SVikas Shivappa	  Select to enable resource allocation and monitoring which are
452f01d7d51SVikas Shivappa	  sub-features of Intel Resource Director Technology(RDT). More
453f01d7d51SVikas Shivappa	  information about RDT can be found in the Intel x86
454f01d7d51SVikas Shivappa	  Architecture Software Developer Manual.
45578e99b4aSFenghua Yu
45678e99b4aSFenghua Yu	  Say N if unsure.
45778e99b4aSFenghua Yu
4588425091fSRavikiran G Thirumalaiif X86_32
459a0d0bb4dSRandy Dunlapconfig X86_BIGSMP
460a0d0bb4dSRandy Dunlap	bool "Support for big SMP systems with more than 8 CPUs"
461a0d0bb4dSRandy Dunlap	depends on SMP
462a0d0bb4dSRandy Dunlap	---help---
463a0d0bb4dSRandy Dunlap	  This option is needed for the systems that have more than 8 CPUs
464a0d0bb4dSRandy Dunlap
465c5c606d9SRavikiran G Thirumalaiconfig X86_EXTENDED_PLATFORM
466c5c606d9SRavikiran G Thirumalai	bool "Support for extended (non-PC) x86 platforms"
467c5c606d9SRavikiran G Thirumalai	default y
4688f9ca475SIngo Molnar	---help---
46906ac8346SIngo Molnar	  If you disable this option then the kernel will only support
47006ac8346SIngo Molnar	  standard PC platforms. (which covers the vast majority of
47106ac8346SIngo Molnar	  systems out there.)
47206ac8346SIngo Molnar
4738425091fSRavikiran G Thirumalai	  If you enable this option then you'll be able to select support
4748425091fSRavikiran G Thirumalai	  for the following (non-PC) 32 bit x86 platforms:
475cb7b8023SBen Hutchings		Goldfish (Android emulator)
4768425091fSRavikiran G Thirumalai		AMD Elan
4778425091fSRavikiran G Thirumalai		RDC R-321x SoC
4788425091fSRavikiran G Thirumalai		SGI 320/540 (Visual Workstation)
47983125a3aSAlessandro Rubini		STA2X11-based (e.g. Northville)
4803f4110a4SThomas Gleixner		Moorestown MID devices
48106ac8346SIngo Molnar
48206ac8346SIngo Molnar	  If you have one of these systems, or if you want to build a
48306ac8346SIngo Molnar	  generic distribution kernel, say Y here - otherwise say N.
4848425091fSRavikiran G Thirumalaiendif
48506ac8346SIngo Molnar
4868425091fSRavikiran G Thirumalaiif X86_64
4878425091fSRavikiran G Thirumalaiconfig X86_EXTENDED_PLATFORM
4888425091fSRavikiran G Thirumalai	bool "Support for extended (non-PC) x86 platforms"
4898425091fSRavikiran G Thirumalai	default y
4908425091fSRavikiran G Thirumalai	---help---
4918425091fSRavikiran G Thirumalai	  If you disable this option then the kernel will only support
4928425091fSRavikiran G Thirumalai	  standard PC platforms. (which covers the vast majority of
4938425091fSRavikiran G Thirumalai	  systems out there.)
4948425091fSRavikiran G Thirumalai
4958425091fSRavikiran G Thirumalai	  If you enable this option then you'll be able to select support
4968425091fSRavikiran G Thirumalai	  for the following (non-PC) 64 bit x86 platforms:
49744b111b5SSteffen Persvold		Numascale NumaChip
4988425091fSRavikiran G Thirumalai		ScaleMP vSMP
4998425091fSRavikiran G Thirumalai		SGI Ultraviolet
5008425091fSRavikiran G Thirumalai
5018425091fSRavikiran G Thirumalai	  If you have one of these systems, or if you want to build a
5028425091fSRavikiran G Thirumalai	  generic distribution kernel, say Y here - otherwise say N.
5038425091fSRavikiran G Thirumalaiendif
504c5c606d9SRavikiran G Thirumalai# This is an alphabetically sorted list of 64 bit extended platforms
505c5c606d9SRavikiran G Thirumalai# Please maintain the alphabetic order if and when there are additions
50644b111b5SSteffen Persvoldconfig X86_NUMACHIP
50744b111b5SSteffen Persvold	bool "Numascale NumaChip"
50844b111b5SSteffen Persvold	depends on X86_64
50944b111b5SSteffen Persvold	depends on X86_EXTENDED_PLATFORM
51044b111b5SSteffen Persvold	depends on NUMA
51144b111b5SSteffen Persvold	depends on SMP
51244b111b5SSteffen Persvold	depends on X86_X2APIC
513f9726bfdSDaniel J Blueman	depends on PCI_MMCONFIG
51444b111b5SSteffen Persvold	---help---
51544b111b5SSteffen Persvold	  Adds support for Numascale NumaChip large-SMP systems. Needed to
51644b111b5SSteffen Persvold	  enable more than ~168 cores.
51744b111b5SSteffen Persvold	  If you don't have one of these, you should say N here.
51803b48632SNick Piggin
5196a48565eSIngo Molnarconfig X86_VSMP
520c5c606d9SRavikiran G Thirumalai	bool "ScaleMP vSMP"
5216276a074SBorislav Petkov	select HYPERVISOR_GUEST
5226a48565eSIngo Molnar	select PARAVIRT
5236a48565eSIngo Molnar	depends on X86_64 && PCI
524c5c606d9SRavikiran G Thirumalai	depends on X86_EXTENDED_PLATFORM
525ead91d4bSShai Fultheim	depends on SMP
5268f9ca475SIngo Molnar	---help---
5276a48565eSIngo Molnar	  Support for ScaleMP vSMP systems.  Say 'Y' here if this kernel is
5286a48565eSIngo Molnar	  supposed to run on these EM64T-based machines.  Only choose this option
5296a48565eSIngo Molnar	  if you have one of these machines.
5306a48565eSIngo Molnar
531c5c606d9SRavikiran G Thirumalaiconfig X86_UV
532c5c606d9SRavikiran G Thirumalai	bool "SGI Ultraviolet"
533c5c606d9SRavikiran G Thirumalai	depends on X86_64
534c5c606d9SRavikiran G Thirumalai	depends on X86_EXTENDED_PLATFORM
53554c28d29SJack Steiner	depends on NUMA
5361ecb4ae5SAndrew Morton	depends on EFI
5379d6c26e7SSuresh Siddha	depends on X86_X2APIC
5381222e564SIngo Molnar	depends on PCI
539c5c606d9SRavikiran G Thirumalai	---help---
540c5c606d9SRavikiran G Thirumalai	  This option is needed in order to support SGI Ultraviolet systems.
541c5c606d9SRavikiran G Thirumalai	  If you don't have one of these, you should say N here.
542c5c606d9SRavikiran G Thirumalai
543c5c606d9SRavikiran G Thirumalai# Following is an alphabetically sorted list of 32 bit extended platforms
544c5c606d9SRavikiran G Thirumalai# Please maintain the alphabetic order if and when there are additions
545506f1d07SSam Ravnborg
546ddd70cf9SJun Nakajimaconfig X86_GOLDFISH
547ddd70cf9SJun Nakajima       bool "Goldfish (Virtual Platform)"
548cb7b8023SBen Hutchings       depends on X86_EXTENDED_PLATFORM
549ddd70cf9SJun Nakajima       ---help---
550ddd70cf9SJun Nakajima	 Enable support for the Goldfish virtual platform used primarily
551ddd70cf9SJun Nakajima	 for Android development. Unless you are building for the Android
552ddd70cf9SJun Nakajima	 Goldfish emulator say N here.
553ddd70cf9SJun Nakajima
554c751e17bSThomas Gleixnerconfig X86_INTEL_CE
555c751e17bSThomas Gleixner	bool "CE4100 TV platform"
556c751e17bSThomas Gleixner	depends on PCI
557c751e17bSThomas Gleixner	depends on PCI_GODIRECT
5586084a6e2SJiang Liu	depends on X86_IO_APIC
559c751e17bSThomas Gleixner	depends on X86_32
560c751e17bSThomas Gleixner	depends on X86_EXTENDED_PLATFORM
56137bc9f50SDirk Brandewie	select X86_REBOOTFIXUPS
562da6b737bSSebastian Andrzej Siewior	select OF
563da6b737bSSebastian Andrzej Siewior	select OF_EARLY_FLATTREE
564c751e17bSThomas Gleixner	---help---
565c751e17bSThomas Gleixner	  Select for the Intel CE media processor (CE4100) SOC.
566c751e17bSThomas Gleixner	  This option compiles in support for the CE4100 SOC for settop
567c751e17bSThomas Gleixner	  boxes and media devices.
568c751e17bSThomas Gleixner
5694cb9b00fSDavid Cohenconfig X86_INTEL_MID
57043605ef1SAlan Cox	bool "Intel MID platform support"
57143605ef1SAlan Cox	depends on X86_EXTENDED_PLATFORM
572edc6bc78SDavid Cohen	depends on X86_PLATFORM_DEVICES
5731ea7c673SAlan Cox	depends on PCI
5743fda5bb4SAndy Shevchenko	depends on X86_64 || (PCI_GOANY && X86_32)
5751ea7c673SAlan Cox	depends on X86_IO_APIC
5767c9c3a1eSAlan Cox	select SFI
5774cb9b00fSDavid Cohen	select I2C
5787c9c3a1eSAlan Cox	select DW_APB_TIMER
5791ea7c673SAlan Cox	select APB_TIMER
5801ea7c673SAlan Cox	select INTEL_SCU_IPC
58115a713dfSMika Westerberg	select MFD_INTEL_MSIC
5821ea7c673SAlan Cox	---help---
5834cb9b00fSDavid Cohen	  Select to build a kernel capable of supporting Intel MID (Mobile
5844cb9b00fSDavid Cohen	  Internet Device) platform systems which do not have the PCI legacy
5854cb9b00fSDavid Cohen	  interfaces. If you are building for a PC class system say N here.
5861ea7c673SAlan Cox
5874cb9b00fSDavid Cohen	  Intel MID platforms are based on an Intel processor and chipset which
5884cb9b00fSDavid Cohen	  consume less power than most of the x86 derivatives.
58943605ef1SAlan Cox
5908bbc2a13SBryan O'Donoghueconfig X86_INTEL_QUARK
5918bbc2a13SBryan O'Donoghue	bool "Intel Quark platform support"
5928bbc2a13SBryan O'Donoghue	depends on X86_32
5938bbc2a13SBryan O'Donoghue	depends on X86_EXTENDED_PLATFORM
5948bbc2a13SBryan O'Donoghue	depends on X86_PLATFORM_DEVICES
5958bbc2a13SBryan O'Donoghue	depends on X86_TSC
5968bbc2a13SBryan O'Donoghue	depends on PCI
5978bbc2a13SBryan O'Donoghue	depends on PCI_GOANY
5988bbc2a13SBryan O'Donoghue	depends on X86_IO_APIC
5998bbc2a13SBryan O'Donoghue	select IOSF_MBI
6008bbc2a13SBryan O'Donoghue	select INTEL_IMR
6019ab6eb51SAndy Shevchenko	select COMMON_CLK
6028bbc2a13SBryan O'Donoghue	---help---
6038bbc2a13SBryan O'Donoghue	  Select to include support for Quark X1000 SoC.
6048bbc2a13SBryan O'Donoghue	  Say Y here if you have a Quark based system such as the Arduino
6058bbc2a13SBryan O'Donoghue	  compatible Intel Galileo.
6068bbc2a13SBryan O'Donoghue
6073d48aab1SMika Westerbergconfig X86_INTEL_LPSS
6083d48aab1SMika Westerberg	bool "Intel Low Power Subsystem Support"
609eebb3e8dSAndy Shevchenko	depends on X86 && ACPI
6103d48aab1SMika Westerberg	select COMMON_CLK
6110f531431SMathias Nyman	select PINCTRL
612eebb3e8dSAndy Shevchenko	select IOSF_MBI
6133d48aab1SMika Westerberg	---help---
6143d48aab1SMika Westerberg	  Select to build support for Intel Low Power Subsystem such as
6153d48aab1SMika Westerberg	  found on Intel Lynxpoint PCH. Selecting this option enables
6160f531431SMathias Nyman	  things like clock tree (common clock framework) and pincontrol
6170f531431SMathias Nyman	  which are needed by the LPSS peripheral drivers.
6183d48aab1SMika Westerberg
61992082a88SKen Xueconfig X86_AMD_PLATFORM_DEVICE
62092082a88SKen Xue	bool "AMD ACPI2Platform devices support"
62192082a88SKen Xue	depends on ACPI
62292082a88SKen Xue	select COMMON_CLK
62392082a88SKen Xue	select PINCTRL
62492082a88SKen Xue	---help---
62592082a88SKen Xue	  Select to interpret AMD specific ACPI device to platform device
62692082a88SKen Xue	  such as I2C, UART, GPIO found on AMD Carrizo and later chipsets.
62792082a88SKen Xue	  I2C and UART depend on COMMON_CLK to set clock. GPIO driver is
62892082a88SKen Xue	  implemented under PINCTRL subsystem.
62992082a88SKen Xue
630ced3ce76SDavid E. Boxconfig IOSF_MBI
631ced3ce76SDavid E. Box	tristate "Intel SoC IOSF Sideband support for SoC platforms"
632ced3ce76SDavid E. Box	depends on PCI
633ced3ce76SDavid E. Box	---help---
634ced3ce76SDavid E. Box	  This option enables sideband register access support for Intel SoC
635ced3ce76SDavid E. Box	  platforms. On these platforms the IOSF sideband is used in lieu of
636ced3ce76SDavid E. Box	  MSR's for some register accesses, mostly but not limited to thermal
637ced3ce76SDavid E. Box	  and power. Drivers may query the availability of this device to
638ced3ce76SDavid E. Box	  determine if they need the sideband in order to work on these
639ced3ce76SDavid E. Box	  platforms. The sideband is available on the following SoC products.
640ced3ce76SDavid E. Box	  This list is not meant to be exclusive.
641ced3ce76SDavid E. Box	   - BayTrail
642ced3ce76SDavid E. Box	   - Braswell
643ced3ce76SDavid E. Box	   - Quark
644ced3ce76SDavid E. Box
645ced3ce76SDavid E. Box	  You should say Y if you are running a kernel on one of these SoC's.
646ced3ce76SDavid E. Box
647ed2226bdSDavid E. Boxconfig IOSF_MBI_DEBUG
648ed2226bdSDavid E. Box	bool "Enable IOSF sideband access through debugfs"
649ed2226bdSDavid E. Box	depends on IOSF_MBI && DEBUG_FS
650ed2226bdSDavid E. Box	---help---
651ed2226bdSDavid E. Box	  Select this option to expose the IOSF sideband access registers (MCR,
652ed2226bdSDavid E. Box	  MDR, MCRX) through debugfs to write and read register information from
653ed2226bdSDavid E. Box	  different units on the SoC. This is most useful for obtaining device
654ed2226bdSDavid E. Box	  state information for debug and analysis. As this is a general access
655ed2226bdSDavid E. Box	  mechanism, users of this option would have specific knowledge of the
656ed2226bdSDavid E. Box	  device they want to access.
657ed2226bdSDavid E. Box
658ed2226bdSDavid E. Box	  If you don't require the option or are in doubt, say N.
659ed2226bdSDavid E. Box
660c5c606d9SRavikiran G Thirumalaiconfig X86_RDC321X
661c5c606d9SRavikiran G Thirumalai	bool "RDC R-321x SoC"
662506f1d07SSam Ravnborg	depends on X86_32
663c5c606d9SRavikiran G Thirumalai	depends on X86_EXTENDED_PLATFORM
664c5c606d9SRavikiran G Thirumalai	select M486
665c5c606d9SRavikiran G Thirumalai	select X86_REBOOTFIXUPS
666c5c606d9SRavikiran G Thirumalai	---help---
667c5c606d9SRavikiran G Thirumalai	  This option is needed for RDC R-321x system-on-chip, also known
668c5c606d9SRavikiran G Thirumalai	  as R-8610-(G).
669c5c606d9SRavikiran G Thirumalai	  If you don't have one of these chips, you should say N here.
670c5c606d9SRavikiran G Thirumalai
671e0c7ae37SIngo Molnarconfig X86_32_NON_STANDARD
6729c398017SIngo Molnar	bool "Support non-standard 32-bit SMP architectures"
6739c398017SIngo Molnar	depends on X86_32 && SMP
674c5c606d9SRavikiran G Thirumalai	depends on X86_EXTENDED_PLATFORM
6758f9ca475SIngo Molnar	---help---
676b5660ba7SH. Peter Anvin	  This option compiles in the bigsmp and STA2X11 default
677b5660ba7SH. Peter Anvin	  subarchitectures.  It is intended for a generic binary
678b5660ba7SH. Peter Anvin	  kernel. If you select them all, kernel will probe it one by
679b5660ba7SH. Peter Anvin	  one and will fallback to default.
680d49c4288SYinghai Lu
681c5c606d9SRavikiran G Thirumalai# Alphabetically sorted list of Non standard 32 bit platforms
682d49c4288SYinghai Lu
683d949f36fSLinus Torvaldsconfig X86_SUPPORTS_MEMORY_FAILURE
6846fc108a0SJan Beulich	def_bool y
685d949f36fSLinus Torvalds	# MCE code calls memory_failure():
686d949f36fSLinus Torvalds	depends on X86_MCE
687d949f36fSLinus Torvalds	# On 32-bit this adds too big of NODES_SHIFT and we run out of page flags:
688d949f36fSLinus Torvalds	# On 32-bit SPARSEMEM adds too big of SECTIONS_WIDTH:
689d949f36fSLinus Torvalds	depends on X86_64 || !SPARSEMEM
690d949f36fSLinus Torvalds	select ARCH_SUPPORTS_MEMORY_FAILURE
691d949f36fSLinus Torvalds
69283125a3aSAlessandro Rubiniconfig STA2X11
69383125a3aSAlessandro Rubini	bool "STA2X11 Companion Chip Support"
69483125a3aSAlessandro Rubini	depends on X86_32_NON_STANDARD && PCI
69583125a3aSAlessandro Rubini	select X86_DEV_DMA_OPS
69683125a3aSAlessandro Rubini	select X86_DMA_REMAP
69783125a3aSAlessandro Rubini	select SWIOTLB
69883125a3aSAlessandro Rubini	select MFD_STA2X11
6990145071bSLinus Walleij	select GPIOLIB
70083125a3aSAlessandro Rubini	default n
70183125a3aSAlessandro Rubini	---help---
70283125a3aSAlessandro Rubini	  This adds support for boards based on the STA2X11 IO-Hub,
70383125a3aSAlessandro Rubini	  a.k.a. "ConneXt". The chip is used in place of the standard
70483125a3aSAlessandro Rubini	  PC chipset, so all "standard" peripherals are missing. If this
70583125a3aSAlessandro Rubini	  option is selected the kernel will still be able to boot on
70683125a3aSAlessandro Rubini	  standard PC machines.
70783125a3aSAlessandro Rubini
70882148d1dSShérabconfig X86_32_IRIS
70982148d1dSShérab	tristate "Eurobraille/Iris poweroff module"
71082148d1dSShérab	depends on X86_32
71182148d1dSShérab	---help---
71282148d1dSShérab	  The Iris machines from EuroBraille do not have APM or ACPI support
71382148d1dSShérab	  to shut themselves down properly.  A special I/O sequence is
71482148d1dSShérab	  needed to do so, which is what this module does at
71582148d1dSShérab	  kernel shutdown.
71682148d1dSShérab
71782148d1dSShérab	  This is only for Iris machines from EuroBraille.
71882148d1dSShérab
71982148d1dSShérab	  If unused, say N.
72082148d1dSShérab
721ae1e9130SIngo Molnarconfig SCHED_OMIT_FRAME_POINTER
7223c2362e6SHarvey Harrison	def_bool y
7233c2362e6SHarvey Harrison	prompt "Single-depth WCHAN output"
724a87d0914SKen Chen	depends on X86
7258f9ca475SIngo Molnar	---help---
726506f1d07SSam Ravnborg	  Calculate simpler /proc/<PID>/wchan values. If this option
727506f1d07SSam Ravnborg	  is disabled then wchan values will recurse back to the
728506f1d07SSam Ravnborg	  caller function. This provides more accurate wchan values,
729506f1d07SSam Ravnborg	  at the expense of slightly more scheduling overhead.
730506f1d07SSam Ravnborg
731506f1d07SSam Ravnborg	  If in doubt, say "Y".
732506f1d07SSam Ravnborg
7336276a074SBorislav Petkovmenuconfig HYPERVISOR_GUEST
7346276a074SBorislav Petkov	bool "Linux guest support"
7358f9ca475SIngo Molnar	---help---
7366276a074SBorislav Petkov	  Say Y here to enable options for running Linux under various hyper-
7376276a074SBorislav Petkov	  visors. This option enables basic hypervisor detection and platform
7386276a074SBorislav Petkov	  setup.
739506f1d07SSam Ravnborg
7406276a074SBorislav Petkov	  If you say N, all options in this submenu will be skipped and
7416276a074SBorislav Petkov	  disabled, and Linux guest support won't be built in.
742506f1d07SSam Ravnborg
7436276a074SBorislav Petkovif HYPERVISOR_GUEST
744506f1d07SSam Ravnborg
745e61bd94aSEduardo Pereira Habkostconfig PARAVIRT
746e61bd94aSEduardo Pereira Habkost	bool "Enable paravirtualization code"
7478f9ca475SIngo Molnar	---help---
748e61bd94aSEduardo Pereira Habkost	  This changes the kernel so it can modify itself when it is run
749e61bd94aSEduardo Pereira Habkost	  under a hypervisor, potentially improving performance significantly
750e61bd94aSEduardo Pereira Habkost	  over full virtualization.  However, when run without a hypervisor
751e61bd94aSEduardo Pereira Habkost	  the kernel is theoretically slower and slightly larger.
752e61bd94aSEduardo Pereira Habkost
7536276a074SBorislav Petkovconfig PARAVIRT_DEBUG
7546276a074SBorislav Petkov	bool "paravirt-ops debugging"
7556276a074SBorislav Petkov	depends on PARAVIRT && DEBUG_KERNEL
7566276a074SBorislav Petkov	---help---
7576276a074SBorislav Petkov	  Enable to debug paravirt_ops internals.  Specifically, BUG if
7586276a074SBorislav Petkov	  a paravirt_op is missing when it is called.
7596276a074SBorislav Petkov
760b4ecc126SJeremy Fitzhardingeconfig PARAVIRT_SPINLOCKS
761b4ecc126SJeremy Fitzhardinge	bool "Paravirtualization layer for spinlocks"
7626ea30386SKees Cook	depends on PARAVIRT && SMP
763b4ecc126SJeremy Fitzhardinge	---help---
764b4ecc126SJeremy Fitzhardinge	  Paravirtualized spinlocks allow a pvops backend to replace the
765b4ecc126SJeremy Fitzhardinge	  spinlock implementation with something virtualization-friendly
766b4ecc126SJeremy Fitzhardinge	  (for example, block the virtual CPU rather than spinning).
767b4ecc126SJeremy Fitzhardinge
7684c4e4f61SRaghavendra K T	  It has a minimal impact on native kernels and gives a nice performance
7694c4e4f61SRaghavendra K T	  benefit on paravirtualized KVM / Xen kernels.
770b4ecc126SJeremy Fitzhardinge
7714c4e4f61SRaghavendra K T	  If you are unsure how to answer this question, answer Y.
772b4ecc126SJeremy Fitzhardinge
77345e898b7SWaiman Longconfig QUEUED_LOCK_STAT
77445e898b7SWaiman Long	bool "Paravirt queued spinlock statistics"
775cfd8983fSPeter Zijlstra	depends on PARAVIRT_SPINLOCKS && DEBUG_FS
77645e898b7SWaiman Long	---help---
77745e898b7SWaiman Long	  Enable the collection of statistical data on the slowpath
77845e898b7SWaiman Long	  behavior of paravirtualized queued spinlocks and report
77945e898b7SWaiman Long	  them on debugfs.
78045e898b7SWaiman Long
7816276a074SBorislav Petkovsource "arch/x86/xen/Kconfig"
7826276a074SBorislav Petkov
7836276a074SBorislav Petkovconfig KVM_GUEST
7846276a074SBorislav Petkov	bool "KVM Guest support (including kvmclock)"
7856276a074SBorislav Petkov	depends on PARAVIRT
7866276a074SBorislav Petkov	select PARAVIRT_CLOCK
7876276a074SBorislav Petkov	default y
7886276a074SBorislav Petkov	---help---
7896276a074SBorislav Petkov	  This option enables various optimizations for running under the KVM
7906276a074SBorislav Petkov	  hypervisor. It includes a paravirtualized clock, so that instead
7916276a074SBorislav Petkov	  of relying on a PIT (or probably other) emulation by the
7926276a074SBorislav Petkov	  underlying device model, the host provides the guest with
7936276a074SBorislav Petkov	  timing infrastructure such as time of day, and system time
7946276a074SBorislav Petkov
7951e20eb85SSrivatsa Vaddagiriconfig KVM_DEBUG_FS
7961e20eb85SSrivatsa Vaddagiri	bool "Enable debug information for KVM Guests in debugfs"
7971e20eb85SSrivatsa Vaddagiri	depends on KVM_GUEST && DEBUG_FS
7981e20eb85SSrivatsa Vaddagiri	default n
7991e20eb85SSrivatsa Vaddagiri	---help---
8001e20eb85SSrivatsa Vaddagiri	  This option enables collection of various statistics for KVM guest.
8011e20eb85SSrivatsa Vaddagiri	  Statistics are displayed in debugfs filesystem. Enabling this option
8021e20eb85SSrivatsa Vaddagiri	  may incur significant overhead.
8031e20eb85SSrivatsa Vaddagiri
8046276a074SBorislav Petkovconfig PARAVIRT_TIME_ACCOUNTING
8056276a074SBorislav Petkov	bool "Paravirtual steal time accounting"
8066276a074SBorislav Petkov	depends on PARAVIRT
8076276a074SBorislav Petkov	default n
8086276a074SBorislav Petkov	---help---
8096276a074SBorislav Petkov	  Select this option to enable fine granularity task steal time
8106276a074SBorislav Petkov	  accounting. Time spent executing other tasks in parallel with
8116276a074SBorislav Petkov	  the current vCPU is discounted from the vCPU power. To account for
8126276a074SBorislav Petkov	  that, there can be a small performance impact.
8136276a074SBorislav Petkov
8146276a074SBorislav Petkov	  If in doubt, say N here.
8156276a074SBorislav Petkov
8167af192c9SGerd Hoffmannconfig PARAVIRT_CLOCK
8177af192c9SGerd Hoffmann	bool
8187af192c9SGerd Hoffmann
8194a362601SJan Kiszkaconfig JAILHOUSE_GUEST
8204a362601SJan Kiszka	bool "Jailhouse non-root cell support"
821abde587bSArnd Bergmann	depends on X86_64 && PCI
82287e65d05SJan Kiszka	select X86_PM_TIMER
8234a362601SJan Kiszka	---help---
8244a362601SJan Kiszka	  This option allows to run Linux as guest in a Jailhouse non-root
8254a362601SJan Kiszka	  cell. You can leave this option disabled if you only want to start
8264a362601SJan Kiszka	  Jailhouse and run Linux afterwards in the root cell.
8274a362601SJan Kiszka
8286276a074SBorislav Petkovendif #HYPERVISOR_GUEST
82997349135SJeremy Fitzhardinge
83008677214SYinghai Luconfig NO_BOOTMEM
831774ea0bcSYinghai Lu	def_bool y
83208677214SYinghai Lu
833506f1d07SSam Ravnborgsource "arch/x86/Kconfig.cpu"
834506f1d07SSam Ravnborg
835506f1d07SSam Ravnborgconfig HPET_TIMER
8363c2362e6SHarvey Harrison	def_bool X86_64
837506f1d07SSam Ravnborg	prompt "HPET Timer Support" if X86_32
8388f9ca475SIngo Molnar	---help---
839506f1d07SSam Ravnborg	  Use the IA-PC HPET (High Precision Event Timer) to manage
840506f1d07SSam Ravnborg	  time in preference to the PIT and RTC, if a HPET is
841506f1d07SSam Ravnborg	  present.
842506f1d07SSam Ravnborg	  HPET is the next generation timer replacing legacy 8254s.
843506f1d07SSam Ravnborg	  The HPET provides a stable time base on SMP
844506f1d07SSam Ravnborg	  systems, unlike the TSC, but it is more expensive to access,
8454e7f9df2SMichael S. Tsirkin	  as it is off-chip.  The interface used is documented
8464e7f9df2SMichael S. Tsirkin	  in the HPET spec, revision 1.
847506f1d07SSam Ravnborg
848506f1d07SSam Ravnborg	  You can safely choose Y here.  However, HPET will only be
849506f1d07SSam Ravnborg	  activated if the platform and the BIOS support this feature.
850506f1d07SSam Ravnborg	  Otherwise the 8254 will be used for timing services.
851506f1d07SSam Ravnborg
852506f1d07SSam Ravnborg	  Choose N to continue using the legacy 8254 timer.
853506f1d07SSam Ravnborg
854506f1d07SSam Ravnborgconfig HPET_EMULATE_RTC
8553c2362e6SHarvey Harrison	def_bool y
8569d8af78bSBernhard Walle	depends on HPET_TIMER && (RTC=y || RTC=m || RTC_DRV_CMOS=m || RTC_DRV_CMOS=y)
857506f1d07SSam Ravnborg
858bb24c471SJacob Panconfig APB_TIMER
859933b9463SAlan Cox       def_bool y if X86_INTEL_MID
860933b9463SAlan Cox       prompt "Intel MID APB Timer Support" if X86_INTEL_MID
86106c3df49SJamie Iles       select DW_APB_TIMER
862a0c3832aSAlan Cox       depends on X86_INTEL_MID && SFI
863bb24c471SJacob Pan       help
864bb24c471SJacob Pan         APB timer is the replacement for 8254, HPET on X86 MID platforms.
865bb24c471SJacob Pan         The APBT provides a stable time base on SMP
866bb24c471SJacob Pan         systems, unlike the TSC, but it is more expensive to access,
867bb24c471SJacob Pan         as it is off-chip. APB timers are always running regardless of CPU
868bb24c471SJacob Pan         C states, they are used as per CPU clockevent device when possible.
869bb24c471SJacob Pan
8706a108a14SDavid Rientjes# Mark as expert because too many people got it wrong.
871506f1d07SSam Ravnborg# The code disables itself when not needed.
8727ae9392cSThomas Petazzoniconfig DMI
8737ae9392cSThomas Petazzoni	default y
874cf074402SArd Biesheuvel	select DMI_SCAN_MACHINE_NON_EFI_FALLBACK
8756a108a14SDavid Rientjes	bool "Enable DMI scanning" if EXPERT
8768f9ca475SIngo Molnar	---help---
8777ae9392cSThomas Petazzoni	  Enabled scanning of DMI to identify machine quirks. Say Y
8787ae9392cSThomas Petazzoni	  here unless you have verified that your setup is not
8797ae9392cSThomas Petazzoni	  affected by entries in the DMI blacklist. Required by PNP
8807ae9392cSThomas Petazzoni	  BIOS code.
8817ae9392cSThomas Petazzoni
882506f1d07SSam Ravnborgconfig GART_IOMMU
88338901f1cSAndi Kleen	bool "Old AMD GART IOMMU support"
884506f1d07SSam Ravnborg	select SWIOTLB
88523ac4ae8SAndreas Herrmann	depends on X86_64 && PCI && AMD_NB
8868f9ca475SIngo Molnar	---help---
887ced3c42cSIngo Molnar	  Provides a driver for older AMD Athlon64/Opteron/Turion/Sempron
888ced3c42cSIngo Molnar	  GART based hardware IOMMUs.
889ced3c42cSIngo Molnar
890ced3c42cSIngo Molnar	  The GART supports full DMA access for devices with 32-bit access
891ced3c42cSIngo Molnar	  limitations, on systems with more than 3 GB. This is usually needed
892ced3c42cSIngo Molnar	  for USB, sound, many IDE/SATA chipsets and some other devices.
893ced3c42cSIngo Molnar
894ced3c42cSIngo Molnar	  Newer systems typically have a modern AMD IOMMU, supported via
895ced3c42cSIngo Molnar	  the CONFIG_AMD_IOMMU=y config option.
896ced3c42cSIngo Molnar
897ced3c42cSIngo Molnar	  In normal configurations this driver is only active when needed:
898ced3c42cSIngo Molnar	  there's more than 3 GB of memory and the system contains a
899ced3c42cSIngo Molnar	  32-bit limited device.
900ced3c42cSIngo Molnar
901ced3c42cSIngo Molnar	  If unsure, say Y.
902506f1d07SSam Ravnborg
903506f1d07SSam Ravnborgconfig CALGARY_IOMMU
904506f1d07SSam Ravnborg	bool "IBM Calgary IOMMU support"
905506f1d07SSam Ravnborg	select SWIOTLB
9066ea30386SKees Cook	depends on X86_64 && PCI
9078f9ca475SIngo Molnar	---help---
908506f1d07SSam Ravnborg	  Support for hardware IOMMUs in IBM's xSeries x366 and x460
909506f1d07SSam Ravnborg	  systems. Needed to run systems with more than 3GB of memory
910506f1d07SSam Ravnborg	  properly with 32-bit PCI devices that do not support DAC
911506f1d07SSam Ravnborg	  (Double Address Cycle). Calgary also supports bus level
912506f1d07SSam Ravnborg	  isolation, where all DMAs pass through the IOMMU.  This
913506f1d07SSam Ravnborg	  prevents them from going anywhere except their intended
914506f1d07SSam Ravnborg	  destination. This catches hard-to-find kernel bugs and
915506f1d07SSam Ravnborg	  mis-behaving drivers and devices that do not use the DMA-API
916506f1d07SSam Ravnborg	  properly to set up their DMA buffers.  The IOMMU can be
917506f1d07SSam Ravnborg	  turned off at boot time with the iommu=off parameter.
918506f1d07SSam Ravnborg	  Normally the kernel will make the right choice by itself.
919506f1d07SSam Ravnborg	  If unsure, say Y.
920506f1d07SSam Ravnborg
921506f1d07SSam Ravnborgconfig CALGARY_IOMMU_ENABLED_BY_DEFAULT
9223c2362e6SHarvey Harrison	def_bool y
9233c2362e6SHarvey Harrison	prompt "Should Calgary be enabled by default?"
924506f1d07SSam Ravnborg	depends on CALGARY_IOMMU
9258f9ca475SIngo Molnar	---help---
926506f1d07SSam Ravnborg	  Should Calgary be enabled by default? if you choose 'y', Calgary
927506f1d07SSam Ravnborg	  will be used (if it exists). If you choose 'n', Calgary will not be
928506f1d07SSam Ravnborg	  used even if it exists. If you choose 'n' and would like to use
929506f1d07SSam Ravnborg	  Calgary anyway, pass 'iommu=calgary' on the kernel command line.
930506f1d07SSam Ravnborg	  If unsure, say Y.
931506f1d07SSam Ravnborg
932506f1d07SSam Ravnborg# need this always selected by IOMMU for the VIA workaround
933506f1d07SSam Ravnborgconfig SWIOTLB
934a1afd01cSJoerg Roedel	def_bool y if X86_64
9358f9ca475SIngo Molnar	---help---
936506f1d07SSam Ravnborg	  Support for software bounce buffers used on x86-64 systems
9374454d327SJoe Millenbach	  which don't have a hardware IOMMU. Using this PCI devices
9384454d327SJoe Millenbach	  which can only access 32-bits of memory can be used on systems
9394454d327SJoe Millenbach	  with more than 3 GB of memory.
9404454d327SJoe Millenbach	  If unsure, say Y.
941506f1d07SSam Ravnborg
942a8522509SFUJITA Tomonoriconfig IOMMU_HELPER
9433120e25eSJan Beulich	def_bool y
9443120e25eSJan Beulich	depends on CALGARY_IOMMU || GART_IOMMU || SWIOTLB || AMD_IOMMU
945d25e26b6SLinus Torvalds
9461184dc2fSMike Travisconfig MAXSMP
947ddb0c5a6SSamuel Thibault	bool "Enable Maximum number of SMP Processors and NUMA Nodes"
9486ea30386SKees Cook	depends on X86_64 && SMP && DEBUG_KERNEL
94936f5101aSMike Travis	select CPUMASK_OFFSTACK
9508f9ca475SIngo Molnar	---help---
951ddb0c5a6SSamuel Thibault	  Enable maximum number of CPUS and NUMA Nodes for this architecture.
9521184dc2fSMike Travis	  If unsure, say N.
953506f1d07SSam Ravnborg
954aec6487eSIngo Molnar#
955aec6487eSIngo Molnar# The maximum number of CPUs supported:
956aec6487eSIngo Molnar#
957aec6487eSIngo Molnar# The main config value is NR_CPUS, which defaults to NR_CPUS_DEFAULT,
958aec6487eSIngo Molnar# and which can be configured interactively in the
959aec6487eSIngo Molnar# [NR_CPUS_RANGE_BEGIN ... NR_CPUS_RANGE_END] range.
960aec6487eSIngo Molnar#
961aec6487eSIngo Molnar# The ranges are different on 32-bit and 64-bit kernels, depending on
962aec6487eSIngo Molnar# hardware capabilities and scalability features of the kernel.
963aec6487eSIngo Molnar#
964aec6487eSIngo Molnar# ( If MAXSMP is enabled we just use the highest possible value and disable
965aec6487eSIngo Molnar#   interactive configuration. )
966aec6487eSIngo Molnar#
967a0d0bb4dSRandy Dunlap
968aec6487eSIngo Molnarconfig NR_CPUS_RANGE_BEGIN
969a0d0bb4dSRandy Dunlap	int
970aec6487eSIngo Molnar	default NR_CPUS_RANGE_END if MAXSMP
971a0d0bb4dSRandy Dunlap	default    1 if !SMP
972a0d0bb4dSRandy Dunlap	default    2
973a0d0bb4dSRandy Dunlap
974aec6487eSIngo Molnarconfig NR_CPUS_RANGE_END
975a0d0bb4dSRandy Dunlap	int
976a0d0bb4dSRandy Dunlap	depends on X86_32
977aec6487eSIngo Molnar	default   64 if  SMP &&  X86_BIGSMP
978aec6487eSIngo Molnar	default    8 if  SMP && !X86_BIGSMP
979a0d0bb4dSRandy Dunlap	default    1 if !SMP
980a0d0bb4dSRandy Dunlap
981aec6487eSIngo Molnarconfig NR_CPUS_RANGE_END
982a0d0bb4dSRandy Dunlap	int
983a0d0bb4dSRandy Dunlap	depends on X86_64
984aec6487eSIngo Molnar	default 8192 if  SMP && ( MAXSMP ||  CPUMASK_OFFSTACK)
985aec6487eSIngo Molnar	default  512 if  SMP && (!MAXSMP && !CPUMASK_OFFSTACK)
986a0d0bb4dSRandy Dunlap	default    1 if !SMP
987aec6487eSIngo Molnar
988aec6487eSIngo Molnarconfig NR_CPUS_DEFAULT
989aec6487eSIngo Molnar	int
990aec6487eSIngo Molnar	depends on X86_32
991aec6487eSIngo Molnar	default   32 if  X86_BIGSMP
992aec6487eSIngo Molnar	default    8 if  SMP
993aec6487eSIngo Molnar	default    1 if !SMP
994aec6487eSIngo Molnar
995aec6487eSIngo Molnarconfig NR_CPUS_DEFAULT
996aec6487eSIngo Molnar	int
997aec6487eSIngo Molnar	depends on X86_64
998a0d0bb4dSRandy Dunlap	default 8192 if  MAXSMP
999a0d0bb4dSRandy Dunlap	default   64 if  SMP
1000aec6487eSIngo Molnar	default    1 if !SMP
1001a0d0bb4dSRandy Dunlap
1002506f1d07SSam Ravnborgconfig NR_CPUS
100336f5101aSMike Travis	int "Maximum number of CPUs" if SMP && !MAXSMP
1004aec6487eSIngo Molnar	range NR_CPUS_RANGE_BEGIN NR_CPUS_RANGE_END
1005aec6487eSIngo Molnar	default NR_CPUS_DEFAULT
10068f9ca475SIngo Molnar	---help---
1007506f1d07SSam Ravnborg	  This allows you to specify the maximum number of CPUs which this
1008bb61ccc7SJosh Boyer	  kernel will support.  If CPUMASK_OFFSTACK is enabled, the maximum
1009cad14bb9SKirill A. Shutemov	  supported value is 8192, otherwise the maximum value is 512.  The
1010506f1d07SSam Ravnborg	  minimum value which makes sense is 2.
1011506f1d07SSam Ravnborg
1012aec6487eSIngo Molnar	  This is purely to save memory: each supported CPU adds about 8KB
1013aec6487eSIngo Molnar	  to the kernel image.
1014506f1d07SSam Ravnborg
1015506f1d07SSam Ravnborgconfig SCHED_SMT
1016506f1d07SSam Ravnborg	bool "SMT (Hyperthreading) scheduler support"
1017c8e56d20SBorislav Petkov	depends on SMP
10188f9ca475SIngo Molnar	---help---
1019506f1d07SSam Ravnborg	  SMT scheduler support improves the CPU scheduler's decision making
1020506f1d07SSam Ravnborg	  when dealing with Intel Pentium 4 chips with HyperThreading at a
1021506f1d07SSam Ravnborg	  cost of slightly increased overhead in some places. If unsure say
1022506f1d07SSam Ravnborg	  N here.
1023506f1d07SSam Ravnborg
1024506f1d07SSam Ravnborgconfig SCHED_MC
10253c2362e6SHarvey Harrison	def_bool y
10263c2362e6SHarvey Harrison	prompt "Multi-core scheduler support"
1027c8e56d20SBorislav Petkov	depends on SMP
10288f9ca475SIngo Molnar	---help---
1029506f1d07SSam Ravnborg	  Multi-core scheduler support improves the CPU scheduler's decision
1030506f1d07SSam Ravnborg	  making when dealing with multi-core CPU chips at a cost of slightly
1031506f1d07SSam Ravnborg	  increased overhead in some places. If unsure say N here.
1032506f1d07SSam Ravnborg
1033de966cf4STim Chenconfig SCHED_MC_PRIO
1034de966cf4STim Chen	bool "CPU core priorities scheduler support"
10350a21fc12SIngo Molnar	depends on SCHED_MC && CPU_SUP_INTEL
10360a21fc12SIngo Molnar	select X86_INTEL_PSTATE
10370a21fc12SIngo Molnar	select CPU_FREQ
1038de966cf4STim Chen	default y
10395e76b2abSTim Chen	---help---
1040de966cf4STim Chen	  Intel Turbo Boost Max Technology 3.0 enabled CPUs have a
1041de966cf4STim Chen	  core ordering determined at manufacturing time, which allows
1042de966cf4STim Chen	  certain cores to reach higher turbo frequencies (when running
1043de966cf4STim Chen	  single threaded workloads) than others.
1044de966cf4STim Chen
1045de966cf4STim Chen	  Enabling this kernel feature teaches the scheduler about
1046de966cf4STim Chen	  the TBM3 (aka ITMT) priority order of the CPU cores and adjusts the
1047de966cf4STim Chen	  scheduler's CPU selection logic accordingly, so that higher
1048de966cf4STim Chen	  overall system performance can be achieved.
1049de966cf4STim Chen
1050de966cf4STim Chen	  This feature will have no effect on CPUs without this feature.
1051de966cf4STim Chen
1052de966cf4STim Chen	  If unsure say Y here.
10535e76b2abSTim Chen
1054506f1d07SSam Ravnborgsource "kernel/Kconfig.preempt"
1055506f1d07SSam Ravnborg
105630b8b006SThomas Gleixnerconfig UP_LATE_INIT
105730b8b006SThomas Gleixner       def_bool y
1058ba360f88SThomas Gleixner       depends on !SMP && X86_LOCAL_APIC
105930b8b006SThomas Gleixner
1060506f1d07SSam Ravnborgconfig X86_UP_APIC
106150849eefSJan Beulich	bool "Local APIC support on uniprocessors" if !PCI_MSI
106250849eefSJan Beulich	default PCI_MSI
106338a1dfdaSBryan O'Donoghue	depends on X86_32 && !SMP && !X86_32_NON_STANDARD
10648f9ca475SIngo Molnar	---help---
1065506f1d07SSam Ravnborg	  A local APIC (Advanced Programmable Interrupt Controller) is an
1066506f1d07SSam Ravnborg	  integrated interrupt controller in the CPU. If you have a single-CPU
1067506f1d07SSam Ravnborg	  system which has a processor with a local APIC, you can say Y here to
1068506f1d07SSam Ravnborg	  enable and use it. If you say Y here even though your machine doesn't
1069506f1d07SSam Ravnborg	  have a local APIC, then the kernel will still run with no slowdown at
1070506f1d07SSam Ravnborg	  all. The local APIC supports CPU-generated self-interrupts (timer,
1071506f1d07SSam Ravnborg	  performance counters), and the NMI watchdog which detects hard
1072506f1d07SSam Ravnborg	  lockups.
1073506f1d07SSam Ravnborg
1074506f1d07SSam Ravnborgconfig X86_UP_IOAPIC
1075506f1d07SSam Ravnborg	bool "IO-APIC support on uniprocessors"
1076506f1d07SSam Ravnborg	depends on X86_UP_APIC
10778f9ca475SIngo Molnar	---help---
1078506f1d07SSam Ravnborg	  An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an
1079506f1d07SSam Ravnborg	  SMP-capable replacement for PC-style interrupt controllers. Most
1080506f1d07SSam Ravnborg	  SMP systems and many recent uniprocessor systems have one.
1081506f1d07SSam Ravnborg
1082506f1d07SSam Ravnborg	  If you have a single-CPU system with an IO-APIC, you can say Y here
1083506f1d07SSam Ravnborg	  to use it. If you say Y here even though your machine doesn't have
1084506f1d07SSam Ravnborg	  an IO-APIC, then the kernel will still run with no slowdown at all.
1085506f1d07SSam Ravnborg
1086506f1d07SSam Ravnborgconfig X86_LOCAL_APIC
10873c2362e6SHarvey Harrison	def_bool y
10880dbc6078SThomas Petazzoni	depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC || PCI_MSI
1089b5dc8e6cSJiang Liu	select IRQ_DOMAIN_HIERARCHY
109052f518a3SJiang Liu	select PCI_MSI_IRQ_DOMAIN if PCI_MSI
1091506f1d07SSam Ravnborg
1092506f1d07SSam Ravnborgconfig X86_IO_APIC
1093b1da1e71SJan Beulich	def_bool y
1094b1da1e71SJan Beulich	depends on X86_LOCAL_APIC || X86_UP_IOAPIC
1095506f1d07SSam Ravnborg
109641b9eb26SStefan Assmannconfig X86_REROUTE_FOR_BROKEN_BOOT_IRQS
109741b9eb26SStefan Assmann	bool "Reroute for broken boot IRQs"
109841b9eb26SStefan Assmann	depends on X86_IO_APIC
10998f9ca475SIngo Molnar	---help---
110041b9eb26SStefan Assmann	  This option enables a workaround that fixes a source of
110141b9eb26SStefan Assmann	  spurious interrupts. This is recommended when threaded
110241b9eb26SStefan Assmann	  interrupt handling is used on systems where the generation of
110341b9eb26SStefan Assmann	  superfluous "boot interrupts" cannot be disabled.
110441b9eb26SStefan Assmann
110541b9eb26SStefan Assmann	  Some chipsets generate a legacy INTx "boot IRQ" when the IRQ
110641b9eb26SStefan Assmann	  entry in the chipset's IO-APIC is masked (as, e.g. the RT
110741b9eb26SStefan Assmann	  kernel does during interrupt handling). On chipsets where this
110841b9eb26SStefan Assmann	  boot IRQ generation cannot be disabled, this workaround keeps
110941b9eb26SStefan Assmann	  the original IRQ line masked so that only the equivalent "boot
111041b9eb26SStefan Assmann	  IRQ" is delivered to the CPUs. The workaround also tells the
111141b9eb26SStefan Assmann	  kernel to set up the IRQ handler on the boot IRQ line. In this
111241b9eb26SStefan Assmann	  way only one interrupt is delivered to the kernel. Otherwise
111341b9eb26SStefan Assmann	  the spurious second interrupt may cause the kernel to bring
111441b9eb26SStefan Assmann	  down (vital) interrupt lines.
111541b9eb26SStefan Assmann
111641b9eb26SStefan Assmann	  Only affects "broken" chipsets. Interrupt sharing may be
111741b9eb26SStefan Assmann	  increased on these systems.
111841b9eb26SStefan Assmann
1119506f1d07SSam Ravnborgconfig X86_MCE
1120bab9bc65SAndi Kleen	bool "Machine Check / overheating reporting"
1121648ed940SChen, Gong	select GENERIC_ALLOCATOR
1122e57dbaf7SBorislav Petkov	default y
1123506f1d07SSam Ravnborg	---help---
1124bab9bc65SAndi Kleen	  Machine Check support allows the processor to notify the
1125bab9bc65SAndi Kleen	  kernel if it detects a problem (e.g. overheating, data corruption).
1126506f1d07SSam Ravnborg	  The action the kernel takes depends on the severity of the problem,
1127bab9bc65SAndi Kleen	  ranging from warning messages to halting the machine.
11284efc0670SAndi Kleen
11295de97c9fSTony Luckconfig X86_MCELOG_LEGACY
11305de97c9fSTony Luck	bool "Support for deprecated /dev/mcelog character device"
11315de97c9fSTony Luck	depends on X86_MCE
11325de97c9fSTony Luck	---help---
11335de97c9fSTony Luck	  Enable support for /dev/mcelog which is needed by the old mcelog
11345de97c9fSTony Luck	  userspace logging daemon. Consider switching to the new generation
11355de97c9fSTony Luck	  rasdaemon solution.
11365de97c9fSTony Luck
1137506f1d07SSam Ravnborgconfig X86_MCE_INTEL
11383c2362e6SHarvey Harrison	def_bool y
11393c2362e6SHarvey Harrison	prompt "Intel MCE features"
1140c1ebf835SAndi Kleen	depends on X86_MCE && X86_LOCAL_APIC
11418f9ca475SIngo Molnar	---help---
1142506f1d07SSam Ravnborg	   Additional support for intel specific MCE features such as
1143506f1d07SSam Ravnborg	   the thermal monitor.
1144506f1d07SSam Ravnborg
1145506f1d07SSam Ravnborgconfig X86_MCE_AMD
11463c2362e6SHarvey Harrison	def_bool y
11473c2362e6SHarvey Harrison	prompt "AMD MCE features"
1148f5382de9SYazen Ghannam	depends on X86_MCE && X86_LOCAL_APIC && AMD_NB
11498f9ca475SIngo Molnar	---help---
1150506f1d07SSam Ravnborg	   Additional support for AMD specific MCE features such as
1151506f1d07SSam Ravnborg	   the DRAM Error Threshold.
1152506f1d07SSam Ravnborg
11534efc0670SAndi Kleenconfig X86_ANCIENT_MCE
11546fc108a0SJan Beulich	bool "Support for old Pentium 5 / WinChip machine checks"
1155c31d9633SAndi Kleen	depends on X86_32 && X86_MCE
11564efc0670SAndi Kleen	---help---
11574efc0670SAndi Kleen	  Include support for machine check handling on old Pentium 5 or WinChip
11585065a706SMasanari Iida	  systems. These typically need to be enabled explicitly on the command
11594efc0670SAndi Kleen	  line.
11604efc0670SAndi Kleen
1161b2762686SAndi Kleenconfig X86_MCE_THRESHOLD
1162b2762686SAndi Kleen	depends on X86_MCE_AMD || X86_MCE_INTEL
11636fc108a0SJan Beulich	def_bool y
1164b2762686SAndi Kleen
1165ea149b36SAndi Kleenconfig X86_MCE_INJECT
1166bc8e80d5SBorislav Petkov	depends on X86_MCE && X86_LOCAL_APIC && DEBUG_FS
1167ea149b36SAndi Kleen	tristate "Machine check injector support"
1168ea149b36SAndi Kleen	---help---
1169ea149b36SAndi Kleen	  Provide support for injecting machine checks for testing purposes.
1170ea149b36SAndi Kleen	  If you don't know what a machine check is and you don't do kernel
1171ea149b36SAndi Kleen	  QA it is safe to say n.
1172ea149b36SAndi Kleen
11734efc0670SAndi Kleenconfig X86_THERMAL_VECTOR
11744efc0670SAndi Kleen	def_bool y
11755bb38adcSAndi Kleen	depends on X86_MCE_INTEL
11764efc0670SAndi Kleen
117707dc900eSPeter Zijlstrasource "arch/x86/events/Kconfig"
1178e633c65aSKan Liang
11795aef51c3SAndy Lutomirskiconfig X86_LEGACY_VM86
11801e642812SIngo Molnar	bool "Legacy VM86 support"
11815aef51c3SAndy Lutomirski	default n
1182506f1d07SSam Ravnborg	depends on X86_32
11838f9ca475SIngo Molnar	---help---
11845aef51c3SAndy Lutomirski	  This option allows user programs to put the CPU into V8086
11855aef51c3SAndy Lutomirski	  mode, which is an 80286-era approximation of 16-bit real mode.
11865aef51c3SAndy Lutomirski
11875aef51c3SAndy Lutomirski	  Some very old versions of X and/or vbetool require this option
11885aef51c3SAndy Lutomirski	  for user mode setting.  Similarly, DOSEMU will use it if
11895aef51c3SAndy Lutomirski	  available to accelerate real mode DOS programs.  However, any
11905aef51c3SAndy Lutomirski	  recent version of DOSEMU, X, or vbetool should be fully
11915aef51c3SAndy Lutomirski	  functional even without kernel VM86 support, as they will all
11921e642812SIngo Molnar	  fall back to software emulation. Nevertheless, if you are using
11931e642812SIngo Molnar	  a 16-bit DOS program where 16-bit performance matters, vm86
11941e642812SIngo Molnar	  mode might be faster than emulation and you might want to
11951e642812SIngo Molnar	  enable this option.
11965aef51c3SAndy Lutomirski
11971e642812SIngo Molnar	  Note that any app that works on a 64-bit kernel is unlikely to
11981e642812SIngo Molnar	  need this option, as 64-bit kernels don't, and can't, support
11991e642812SIngo Molnar	  V8086 mode. This option is also unrelated to 16-bit protected
12001e642812SIngo Molnar	  mode and is not needed to run most 16-bit programs under Wine.
12015aef51c3SAndy Lutomirski
12021e642812SIngo Molnar	  Enabling this option increases the complexity of the kernel
12031e642812SIngo Molnar	  and slows down exception handling a tiny bit.
12045aef51c3SAndy Lutomirski
12051e642812SIngo Molnar	  If unsure, say N here.
12065aef51c3SAndy Lutomirski
12075aef51c3SAndy Lutomirskiconfig VM86
12085aef51c3SAndy Lutomirski       bool
12095aef51c3SAndy Lutomirski       default X86_LEGACY_VM86
121034273f41SH. Peter Anvin
121134273f41SH. Peter Anvinconfig X86_16BIT
121234273f41SH. Peter Anvin	bool "Enable support for 16-bit segments" if EXPERT
121334273f41SH. Peter Anvin	default y
1214a5b9e5a2SAndy Lutomirski	depends on MODIFY_LDT_SYSCALL
121534273f41SH. Peter Anvin	---help---
121634273f41SH. Peter Anvin	  This option is required by programs like Wine to run 16-bit
121734273f41SH. Peter Anvin	  protected mode legacy code on x86 processors.  Disabling
121834273f41SH. Peter Anvin	  this option saves about 300 bytes on i386, or around 6K text
121934273f41SH. Peter Anvin	  plus 16K runtime memory on x86-64,
122034273f41SH. Peter Anvin
122134273f41SH. Peter Anvinconfig X86_ESPFIX32
122234273f41SH. Peter Anvin	def_bool y
122334273f41SH. Peter Anvin	depends on X86_16BIT && X86_32
1224506f1d07SSam Ravnborg
1225197725deSH. Peter Anvinconfig X86_ESPFIX64
1226197725deSH. Peter Anvin	def_bool y
122734273f41SH. Peter Anvin	depends on X86_16BIT && X86_64
1228506f1d07SSam Ravnborg
12291ad83c85SAndy Lutomirskiconfig X86_VSYSCALL_EMULATION
12301ad83c85SAndy Lutomirski       bool "Enable vsyscall emulation" if EXPERT
12311ad83c85SAndy Lutomirski       default y
12321ad83c85SAndy Lutomirski       depends on X86_64
12331ad83c85SAndy Lutomirski       ---help---
12341ad83c85SAndy Lutomirski	 This enables emulation of the legacy vsyscall page.  Disabling
12351ad83c85SAndy Lutomirski	 it is roughly equivalent to booting with vsyscall=none, except
12361ad83c85SAndy Lutomirski	 that it will also disable the helpful warning if a program
12371ad83c85SAndy Lutomirski	 tries to use a vsyscall.  With this option set to N, offending
12381ad83c85SAndy Lutomirski	 programs will just segfault, citing addresses of the form
12391ad83c85SAndy Lutomirski	 0xffffffffff600?00.
12401ad83c85SAndy Lutomirski
12411ad83c85SAndy Lutomirski	 This option is required by many programs built before 2013, and
12421ad83c85SAndy Lutomirski	 care should be used even with newer programs if set to N.
12431ad83c85SAndy Lutomirski
12441ad83c85SAndy Lutomirski	 Disabling this option saves about 7K of kernel size and
12451ad83c85SAndy Lutomirski	 possibly 4K of additional runtime pagetable memory.
12461ad83c85SAndy Lutomirski
1247506f1d07SSam Ravnborgconfig TOSHIBA
1248506f1d07SSam Ravnborg	tristate "Toshiba Laptop support"
1249506f1d07SSam Ravnborg	depends on X86_32
1250506f1d07SSam Ravnborg	---help---
1251506f1d07SSam Ravnborg	  This adds a driver to safely access the System Management Mode of
1252506f1d07SSam Ravnborg	  the CPU on Toshiba portables with a genuine Toshiba BIOS. It does
1253506f1d07SSam Ravnborg	  not work on models with a Phoenix BIOS. The System Management Mode
1254506f1d07SSam Ravnborg	  is used to set the BIOS and power saving options on Toshiba portables.
1255506f1d07SSam Ravnborg
1256506f1d07SSam Ravnborg	  For information on utilities to make use of this driver see the
1257506f1d07SSam Ravnborg	  Toshiba Linux utilities web site at:
1258506f1d07SSam Ravnborg	  <http://www.buzzard.org.uk/toshiba/>.
1259506f1d07SSam Ravnborg
1260506f1d07SSam Ravnborg	  Say Y if you intend to run this kernel on a Toshiba portable.
1261506f1d07SSam Ravnborg	  Say N otherwise.
1262506f1d07SSam Ravnborg
1263506f1d07SSam Ravnborgconfig I8K
1264039ae585SPali Rohár	tristate "Dell i8k legacy laptop support"
1265949a9d70SJean Delvare	select HWMON
1266039ae585SPali Rohár	select SENSORS_DELL_SMM
1267506f1d07SSam Ravnborg	---help---
1268039ae585SPali Rohár	  This option enables legacy /proc/i8k userspace interface in hwmon
1269039ae585SPali Rohár	  dell-smm-hwmon driver. Character file /proc/i8k reports bios version,
1270039ae585SPali Rohár	  temperature and allows controlling fan speeds of Dell laptops via
1271039ae585SPali Rohár	  System Management Mode. For old Dell laptops (like Dell Inspiron 8000)
1272039ae585SPali Rohár	  it reports also power and hotkey status. For fan speed control is
1273039ae585SPali Rohár	  needed userspace package i8kutils.
1274506f1d07SSam Ravnborg
1275039ae585SPali Rohár	  Say Y if you intend to run this kernel on old Dell laptops or want to
1276039ae585SPali Rohár	  use userspace package i8kutils.
1277506f1d07SSam Ravnborg	  Say N otherwise.
1278506f1d07SSam Ravnborg
1279506f1d07SSam Ravnborgconfig X86_REBOOTFIXUPS
12809ba16087SJan Beulich	bool "Enable X86 board specific fixups for reboot"
12819ba16087SJan Beulich	depends on X86_32
1282506f1d07SSam Ravnborg	---help---
1283506f1d07SSam Ravnborg	  This enables chipset and/or board specific fixups to be done
1284506f1d07SSam Ravnborg	  in order to get reboot to work correctly. This is only needed on
1285506f1d07SSam Ravnborg	  some combinations of hardware and BIOS. The symptom, for which
1286506f1d07SSam Ravnborg	  this config is intended, is when reboot ends with a stalled/hung
1287506f1d07SSam Ravnborg	  system.
1288506f1d07SSam Ravnborg
1289506f1d07SSam Ravnborg	  Currently, the only fixup is for the Geode machines using
12905e3a77e9SFlorian Fainelli	  CS5530A and CS5536 chipsets and the RDC R-321x SoC.
1291506f1d07SSam Ravnborg
1292506f1d07SSam Ravnborg	  Say Y if you want to enable the fixup. Currently, it's safe to
1293506f1d07SSam Ravnborg	  enable this option even if you don't need it.
1294506f1d07SSam Ravnborg	  Say N otherwise.
1295506f1d07SSam Ravnborg
1296506f1d07SSam Ravnborgconfig MICROCODE
12979a2bc335SBorislav Petkov	bool "CPU microcode loading support"
12989a2bc335SBorislav Petkov	default y
129980030e3dSBorislav Petkov	depends on CPU_SUP_AMD || CPU_SUP_INTEL
1300506f1d07SSam Ravnborg	select FW_LOADER
1301506f1d07SSam Ravnborg	---help---
1302506f1d07SSam Ravnborg	  If you say Y here, you will be able to update the microcode on
13035f9c01aaSBorislav Petkov	  Intel and AMD processors. The Intel support is for the IA32 family,
13045f9c01aaSBorislav Petkov	  e.g. Pentium Pro, Pentium II, Pentium III, Pentium 4, Xeon etc. The
13055f9c01aaSBorislav Petkov	  AMD support is for families 0x10 and later. You will obviously need
13065f9c01aaSBorislav Petkov	  the actual microcode binary data itself which is not shipped with
13075f9c01aaSBorislav Petkov	  the Linux kernel.
1308506f1d07SSam Ravnborg
13095f9c01aaSBorislav Petkov	  The preferred method to load microcode from a detached initrd is described
13105f9c01aaSBorislav Petkov	  in Documentation/x86/early-microcode.txt. For that you need to enable
13115f9c01aaSBorislav Petkov	  CONFIG_BLK_DEV_INITRD in order for the loader to be able to scan the
13125f9c01aaSBorislav Petkov	  initrd for microcode blobs.
1313506f1d07SSam Ravnborg
1314c508c46eSBenjamin Gilbert	  In addition, you can build the microcode into the kernel. For that you
1315c508c46eSBenjamin Gilbert	  need to add the vendor-supplied microcode to the CONFIG_EXTRA_FIRMWARE
1316c508c46eSBenjamin Gilbert	  config option.
1317506f1d07SSam Ravnborg
13188d86f390SPeter Orubaconfig MICROCODE_INTEL
1319e43f6e67SBorislav Petkov	bool "Intel microcode loading support"
13208d86f390SPeter Oruba	depends on MICROCODE
13218d86f390SPeter Oruba	default MICROCODE
13228d86f390SPeter Oruba	select FW_LOADER
13238f9ca475SIngo Molnar	---help---
13248d86f390SPeter Oruba	  This options enables microcode patch loading support for Intel
13258d86f390SPeter Oruba	  processors.
13268d86f390SPeter Oruba
1327b8989db9SAlan	  For the current Intel microcode data package go to
1328b8989db9SAlan	  <https://downloadcenter.intel.com> and search for
1329b8989db9SAlan	  'Linux Processor Microcode Data File'.
13308d86f390SPeter Oruba
133180cc9f10SPeter Orubaconfig MICROCODE_AMD
1332e43f6e67SBorislav Petkov	bool "AMD microcode loading support"
133380cc9f10SPeter Oruba	depends on MICROCODE
133480cc9f10SPeter Oruba	select FW_LOADER
13358f9ca475SIngo Molnar	---help---
133680cc9f10SPeter Oruba	  If you select this option, microcode patch loading support for AMD
133780cc9f10SPeter Oruba	  processors will be enabled.
133880cc9f10SPeter Oruba
1339506f1d07SSam Ravnborgconfig MICROCODE_OLD_INTERFACE
13403c2362e6SHarvey Harrison	def_bool y
1341506f1d07SSam Ravnborg	depends on MICROCODE
1342506f1d07SSam Ravnborg
1343506f1d07SSam Ravnborgconfig X86_MSR
1344506f1d07SSam Ravnborg	tristate "/dev/cpu/*/msr - Model-specific register support"
13458f9ca475SIngo Molnar	---help---
1346506f1d07SSam Ravnborg	  This device gives privileged processes access to the x86
1347506f1d07SSam Ravnborg	  Model-Specific Registers (MSRs).  It is a character device with
1348506f1d07SSam Ravnborg	  major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr.
1349506f1d07SSam Ravnborg	  MSR accesses are directed to a specific CPU on multi-processor
1350506f1d07SSam Ravnborg	  systems.
1351506f1d07SSam Ravnborg
1352506f1d07SSam Ravnborgconfig X86_CPUID
1353506f1d07SSam Ravnborg	tristate "/dev/cpu/*/cpuid - CPU information support"
13548f9ca475SIngo Molnar	---help---
1355506f1d07SSam Ravnborg	  This device gives processes access to the x86 CPUID instruction to
1356506f1d07SSam Ravnborg	  be executed on a specific processor.  It is a character device
1357506f1d07SSam Ravnborg	  with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to
1358506f1d07SSam Ravnborg	  /dev/cpu/31/cpuid.
1359506f1d07SSam Ravnborg
1360506f1d07SSam Ravnborgchoice
1361506f1d07SSam Ravnborg	prompt "High Memory Support"
13626fc108a0SJan Beulich	default HIGHMEM4G
1363506f1d07SSam Ravnborg	depends on X86_32
1364506f1d07SSam Ravnborg
1365506f1d07SSam Ravnborgconfig NOHIGHMEM
1366506f1d07SSam Ravnborg	bool "off"
1367506f1d07SSam Ravnborg	---help---
1368506f1d07SSam Ravnborg	  Linux can use up to 64 Gigabytes of physical memory on x86 systems.
1369506f1d07SSam Ravnborg	  However, the address space of 32-bit x86 processors is only 4
1370506f1d07SSam Ravnborg	  Gigabytes large. That means that, if you have a large amount of
1371506f1d07SSam Ravnborg	  physical memory, not all of it can be "permanently mapped" by the
1372506f1d07SSam Ravnborg	  kernel. The physical memory that's not permanently mapped is called
1373506f1d07SSam Ravnborg	  "high memory".
1374506f1d07SSam Ravnborg
1375506f1d07SSam Ravnborg	  If you are compiling a kernel which will never run on a machine with
1376506f1d07SSam Ravnborg	  more than 1 Gigabyte total physical RAM, answer "off" here (default
1377506f1d07SSam Ravnborg	  choice and suitable for most users). This will result in a "3GB/1GB"
1378506f1d07SSam Ravnborg	  split: 3GB are mapped so that each process sees a 3GB virtual memory
1379506f1d07SSam Ravnborg	  space and the remaining part of the 4GB virtual memory space is used
1380506f1d07SSam Ravnborg	  by the kernel to permanently map as much physical memory as
1381506f1d07SSam Ravnborg	  possible.
1382506f1d07SSam Ravnborg
1383506f1d07SSam Ravnborg	  If the machine has between 1 and 4 Gigabytes physical RAM, then
1384506f1d07SSam Ravnborg	  answer "4GB" here.
1385506f1d07SSam Ravnborg
1386506f1d07SSam Ravnborg	  If more than 4 Gigabytes is used then answer "64GB" here. This
1387506f1d07SSam Ravnborg	  selection turns Intel PAE (Physical Address Extension) mode on.
1388506f1d07SSam Ravnborg	  PAE implements 3-level paging on IA32 processors. PAE is fully
1389506f1d07SSam Ravnborg	  supported by Linux, PAE mode is implemented on all recent Intel
1390506f1d07SSam Ravnborg	  processors (Pentium Pro and better). NOTE: If you say "64GB" here,
1391506f1d07SSam Ravnborg	  then the kernel will not boot on CPUs that don't support PAE!
1392506f1d07SSam Ravnborg
1393506f1d07SSam Ravnborg	  The actual amount of total physical memory will either be
1394506f1d07SSam Ravnborg	  auto detected or can be forced by using a kernel command line option
1395506f1d07SSam Ravnborg	  such as "mem=256M". (Try "man bootparam" or see the documentation of
1396506f1d07SSam Ravnborg	  your boot loader (lilo or loadlin) about how to pass options to the
1397506f1d07SSam Ravnborg	  kernel at boot time.)
1398506f1d07SSam Ravnborg
1399506f1d07SSam Ravnborg	  If unsure, say "off".
1400506f1d07SSam Ravnborg
1401506f1d07SSam Ravnborgconfig HIGHMEM4G
1402506f1d07SSam Ravnborg	bool "4GB"
14038f9ca475SIngo Molnar	---help---
1404506f1d07SSam Ravnborg	  Select this if you have a 32-bit processor and between 1 and 4
1405506f1d07SSam Ravnborg	  gigabytes of physical RAM.
1406506f1d07SSam Ravnborg
1407506f1d07SSam Ravnborgconfig HIGHMEM64G
1408506f1d07SSam Ravnborg	bool "64GB"
140969b8d3fcSMatthew Whitehead	depends on !M486 && !M586 && !M586TSC && !M586MMX && !MGEODE_LX && !MGEODEGX1 && !MCYRIXIII && !MELAN && !MWINCHIPC6 && !WINCHIP3D && !MK6
1410506f1d07SSam Ravnborg	select X86_PAE
14118f9ca475SIngo Molnar	---help---
1412506f1d07SSam Ravnborg	  Select this if you have a 32-bit processor and more than 4
1413506f1d07SSam Ravnborg	  gigabytes of physical RAM.
1414506f1d07SSam Ravnborg
1415506f1d07SSam Ravnborgendchoice
1416506f1d07SSam Ravnborg
1417506f1d07SSam Ravnborgchoice
14186a108a14SDavid Rientjes	prompt "Memory split" if EXPERT
1419506f1d07SSam Ravnborg	default VMSPLIT_3G
1420506f1d07SSam Ravnborg	depends on X86_32
14218f9ca475SIngo Molnar	---help---
1422506f1d07SSam Ravnborg	  Select the desired split between kernel and user memory.
1423506f1d07SSam Ravnborg
1424506f1d07SSam Ravnborg	  If the address range available to the kernel is less than the
1425506f1d07SSam Ravnborg	  physical memory installed, the remaining memory will be available
1426506f1d07SSam Ravnborg	  as "high memory". Accessing high memory is a little more costly
1427506f1d07SSam Ravnborg	  than low memory, as it needs to be mapped into the kernel first.
1428506f1d07SSam Ravnborg	  Note that increasing the kernel address space limits the range
1429506f1d07SSam Ravnborg	  available to user programs, making the address space there
1430506f1d07SSam Ravnborg	  tighter.  Selecting anything other than the default 3G/1G split
1431506f1d07SSam Ravnborg	  will also likely make your kernel incompatible with binary-only
1432506f1d07SSam Ravnborg	  kernel modules.
1433506f1d07SSam Ravnborg
1434506f1d07SSam Ravnborg	  If you are not absolutely sure what you are doing, leave this
1435506f1d07SSam Ravnborg	  option alone!
1436506f1d07SSam Ravnborg
1437506f1d07SSam Ravnborg	config VMSPLIT_3G
1438506f1d07SSam Ravnborg		bool "3G/1G user/kernel split"
1439506f1d07SSam Ravnborg	config VMSPLIT_3G_OPT
1440506f1d07SSam Ravnborg		depends on !X86_PAE
1441506f1d07SSam Ravnborg		bool "3G/1G user/kernel split (for full 1G low memory)"
1442506f1d07SSam Ravnborg	config VMSPLIT_2G
1443506f1d07SSam Ravnborg		bool "2G/2G user/kernel split"
1444506f1d07SSam Ravnborg	config VMSPLIT_2G_OPT
1445506f1d07SSam Ravnborg		depends on !X86_PAE
1446506f1d07SSam Ravnborg		bool "2G/2G user/kernel split (for full 2G low memory)"
1447506f1d07SSam Ravnborg	config VMSPLIT_1G
1448506f1d07SSam Ravnborg		bool "1G/3G user/kernel split"
1449506f1d07SSam Ravnborgendchoice
1450506f1d07SSam Ravnborg
1451506f1d07SSam Ravnborgconfig PAGE_OFFSET
1452506f1d07SSam Ravnborg	hex
1453506f1d07SSam Ravnborg	default 0xB0000000 if VMSPLIT_3G_OPT
1454506f1d07SSam Ravnborg	default 0x80000000 if VMSPLIT_2G
1455506f1d07SSam Ravnborg	default 0x78000000 if VMSPLIT_2G_OPT
1456506f1d07SSam Ravnborg	default 0x40000000 if VMSPLIT_1G
1457506f1d07SSam Ravnborg	default 0xC0000000
1458506f1d07SSam Ravnborg	depends on X86_32
1459506f1d07SSam Ravnborg
1460506f1d07SSam Ravnborgconfig HIGHMEM
14613c2362e6SHarvey Harrison	def_bool y
1462506f1d07SSam Ravnborg	depends on X86_32 && (HIGHMEM64G || HIGHMEM4G)
1463506f1d07SSam Ravnborg
1464506f1d07SSam Ravnborgconfig X86_PAE
14659ba16087SJan Beulich	bool "PAE (Physical Address Extension) Support"
1466506f1d07SSam Ravnborg	depends on X86_32 && !HIGHMEM4G
14679d99c712SChristian Melki	select SWIOTLB
14688f9ca475SIngo Molnar	---help---
1469506f1d07SSam Ravnborg	  PAE is required for NX support, and furthermore enables
1470506f1d07SSam Ravnborg	  larger swapspace support for non-overcommit purposes. It
1471506f1d07SSam Ravnborg	  has the cost of more pagetable lookup overhead, and also
1472506f1d07SSam Ravnborg	  consumes more pagetable space per process.
1473506f1d07SSam Ravnborg
147477ef56e4SKirill A. Shutemovconfig X86_5LEVEL
147577ef56e4SKirill A. Shutemov	bool "Enable 5-level page tables support"
1476eedb92abSKirill A. Shutemov	select DYNAMIC_MEMORY_LAYOUT
1477162434e7SKirill A. Shutemov	select SPARSEMEM_VMEMMAP
147877ef56e4SKirill A. Shutemov	depends on X86_64
147977ef56e4SKirill A. Shutemov	---help---
148077ef56e4SKirill A. Shutemov	  5-level paging enables access to larger address space:
148177ef56e4SKirill A. Shutemov	  upto 128 PiB of virtual address space and 4 PiB of
148277ef56e4SKirill A. Shutemov	  physical address space.
148377ef56e4SKirill A. Shutemov
148477ef56e4SKirill A. Shutemov	  It will be supported by future Intel CPUs.
148577ef56e4SKirill A. Shutemov
14866657fca0SKirill A. Shutemov	  A kernel with the option enabled can be booted on machines that
14876657fca0SKirill A. Shutemov	  support 4- or 5-level paging.
148877ef56e4SKirill A. Shutemov
148977ef56e4SKirill A. Shutemov	  See Documentation/x86/x86_64/5level-paging.txt for more
149077ef56e4SKirill A. Shutemov	  information.
149177ef56e4SKirill A. Shutemov
149277ef56e4SKirill A. Shutemov	  Say N if unsure.
149377ef56e4SKirill A. Shutemov
1494600715dcSJeremy Fitzhardingeconfig ARCH_PHYS_ADDR_T_64BIT
14953120e25eSJan Beulich	def_bool y
14963120e25eSJan Beulich	depends on X86_64 || X86_PAE
1497600715dcSJeremy Fitzhardinge
149866f2b061SFUJITA Tomonoriconfig ARCH_DMA_ADDR_T_64BIT
14993120e25eSJan Beulich	def_bool y
15003120e25eSJan Beulich	depends on X86_64 || HIGHMEM64G
150166f2b061SFUJITA Tomonori
150210971ab2SIngo Molnarconfig X86_DIRECT_GBPAGES
1503e5008abeSLuis R. Rodriguez	def_bool y
15044675ff05SLevin, Alexander (Sasha Levin)	depends on X86_64 && !DEBUG_PAGEALLOC
15058f9ca475SIngo Molnar	---help---
150610971ab2SIngo Molnar	  Certain kernel features effectively disable kernel
150710971ab2SIngo Molnar	  linear 1 GB mappings (even if the CPU otherwise
150810971ab2SIngo Molnar	  supports them), so don't confuse the user by printing
150910971ab2SIngo Molnar	  that we have them enabled.
15109e899816SNick Piggin
15117744ccdbSTom Lendackyconfig ARCH_HAS_MEM_ENCRYPT
15127744ccdbSTom Lendacky	def_bool y
15137744ccdbSTom Lendacky
15147744ccdbSTom Lendackyconfig AMD_MEM_ENCRYPT
15157744ccdbSTom Lendacky	bool "AMD Secure Memory Encryption (SME) support"
15167744ccdbSTom Lendacky	depends on X86_64 && CPU_SUP_AMD
15177744ccdbSTom Lendacky	---help---
15187744ccdbSTom Lendacky	  Say yes to enable support for the encryption of system memory.
15197744ccdbSTom Lendacky	  This requires an AMD processor that supports Secure Memory
15207744ccdbSTom Lendacky	  Encryption (SME).
15217744ccdbSTom Lendacky
15227744ccdbSTom Lendackyconfig AMD_MEM_ENCRYPT_ACTIVE_BY_DEFAULT
15237744ccdbSTom Lendacky	bool "Activate AMD Secure Memory Encryption (SME) by default"
15247744ccdbSTom Lendacky	default y
15257744ccdbSTom Lendacky	depends on AMD_MEM_ENCRYPT
15267744ccdbSTom Lendacky	---help---
15277744ccdbSTom Lendacky	  Say yes to have system memory encrypted by default if running on
15287744ccdbSTom Lendacky	  an AMD processor that supports Secure Memory Encryption (SME).
15297744ccdbSTom Lendacky
15307744ccdbSTom Lendacky	  If set to Y, then the encryption of system memory can be
15317744ccdbSTom Lendacky	  deactivated with the mem_encrypt=off command line option.
15327744ccdbSTom Lendacky
15337744ccdbSTom Lendacky	  If set to N, then the encryption of system memory can be
15347744ccdbSTom Lendacky	  activated with the mem_encrypt=on command line option.
15357744ccdbSTom Lendacky
1536f88a68faSTom Lendackyconfig ARCH_USE_MEMREMAP_PROT
1537f88a68faSTom Lendacky	def_bool y
1538f88a68faSTom Lendacky	depends on AMD_MEM_ENCRYPT
1539f88a68faSTom Lendacky
1540506f1d07SSam Ravnborg# Common NUMA Features
1541506f1d07SSam Ravnborgconfig NUMA
1542fd51b2d7SKOSAKI Motohiro	bool "Numa Memory Allocation and Scheduler Support"
1543506f1d07SSam Ravnborg	depends on SMP
1544b5660ba7SH. Peter Anvin	depends on X86_64 || (X86_32 && HIGHMEM64G && X86_BIGSMP)
1545b5660ba7SH. Peter Anvin	default y if X86_BIGSMP
15468f9ca475SIngo Molnar	---help---
1547506f1d07SSam Ravnborg	  Enable NUMA (Non Uniform Memory Access) support.
1548fd51b2d7SKOSAKI Motohiro
1549506f1d07SSam Ravnborg	  The kernel will try to allocate memory used by a CPU on the
1550506f1d07SSam Ravnborg	  local memory controller of the CPU and add some more
1551506f1d07SSam Ravnborg	  NUMA awareness to the kernel.
1552506f1d07SSam Ravnborg
1553c280ea5eSIngo Molnar	  For 64-bit this is recommended if the system is Intel Core i7
1554fd51b2d7SKOSAKI Motohiro	  (or later), AMD Opteron, or EM64T NUMA.
1555fd51b2d7SKOSAKI Motohiro
1556b5660ba7SH. Peter Anvin	  For 32-bit this is only needed if you boot a 32-bit
15577cf6c945SDavid Rientjes	  kernel on a 64-bit NUMA platform.
1558fd51b2d7SKOSAKI Motohiro
1559fd51b2d7SKOSAKI Motohiro	  Otherwise, you should say N.
1560506f1d07SSam Ravnborg
1561eec1d4faSHans Rosenfeldconfig AMD_NUMA
15623c2362e6SHarvey Harrison	def_bool y
15633c2362e6SHarvey Harrison	prompt "Old style AMD Opteron NUMA detection"
15645da0ef9aSTejun Heo	depends on X86_64 && NUMA && PCI
15658f9ca475SIngo Molnar	---help---
1566eec1d4faSHans Rosenfeld	  Enable AMD NUMA node topology detection.  You should say Y here if
1567eec1d4faSHans Rosenfeld	  you have a multi processor AMD system. This uses an old method to
1568eec1d4faSHans Rosenfeld	  read the NUMA configuration directly from the builtin Northbridge
1569eec1d4faSHans Rosenfeld	  of Opteron. It is recommended to use X86_64_ACPI_NUMA instead,
1570eec1d4faSHans Rosenfeld	  which also takes priority if both are compiled in.
1571506f1d07SSam Ravnborg
1572506f1d07SSam Ravnborgconfig X86_64_ACPI_NUMA
15733c2362e6SHarvey Harrison	def_bool y
15743c2362e6SHarvey Harrison	prompt "ACPI NUMA detection"
1575506f1d07SSam Ravnborg	depends on X86_64 && NUMA && ACPI && PCI
1576506f1d07SSam Ravnborg	select ACPI_NUMA
15778f9ca475SIngo Molnar	---help---
1578506f1d07SSam Ravnborg	  Enable ACPI SRAT based node topology detection.
1579506f1d07SSam Ravnborg
15806ec6e0d9SSuresh Siddha# Some NUMA nodes have memory ranges that span
15816ec6e0d9SSuresh Siddha# other nodes.  Even though a pfn is valid and
15826ec6e0d9SSuresh Siddha# between a node's start and end pfns, it may not
15836ec6e0d9SSuresh Siddha# reside on that node.  See memmap_init_zone()
15846ec6e0d9SSuresh Siddha# for details.
15856ec6e0d9SSuresh Siddhaconfig NODES_SPAN_OTHER_NODES
15866ec6e0d9SSuresh Siddha	def_bool y
15876ec6e0d9SSuresh Siddha	depends on X86_64_ACPI_NUMA
15886ec6e0d9SSuresh Siddha
1589506f1d07SSam Ravnborgconfig NUMA_EMU
1590506f1d07SSam Ravnborg	bool "NUMA emulation"
15911b7e03efSTejun Heo	depends on NUMA
15928f9ca475SIngo Molnar	---help---
1593506f1d07SSam Ravnborg	  Enable NUMA emulation. A flat machine will be split
1594506f1d07SSam Ravnborg	  into virtual nodes when booted with "numa=fake=N", where N is the
1595506f1d07SSam Ravnborg	  number of nodes. This is only useful for debugging.
1596506f1d07SSam Ravnborg
1597506f1d07SSam Ravnborgconfig NODES_SHIFT
1598d25e26b6SLinus Torvalds	int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP
159951591e31SDavid Rientjes	range 1 10
160051591e31SDavid Rientjes	default "10" if MAXSMP
1601506f1d07SSam Ravnborg	default "6" if X86_64
1602506f1d07SSam Ravnborg	default "3"
1603506f1d07SSam Ravnborg	depends on NEED_MULTIPLE_NODES
16048f9ca475SIngo Molnar	---help---
16051184dc2fSMike Travis	  Specify the maximum number of NUMA Nodes available on the target
1606692105b8SMatt LaPlante	  system.  Increases memory reserved to accommodate various tables.
1607506f1d07SSam Ravnborg
1608506f1d07SSam Ravnborgconfig ARCH_HAVE_MEMORY_PRESENT
16093c2362e6SHarvey Harrison	def_bool y
1610506f1d07SSam Ravnborg	depends on X86_32 && DISCONTIGMEM
1611506f1d07SSam Ravnborg
1612506f1d07SSam Ravnborgconfig NEED_NODE_MEMMAP_SIZE
16133c2362e6SHarvey Harrison	def_bool y
1614506f1d07SSam Ravnborg	depends on X86_32 && (DISCONTIGMEM || SPARSEMEM)
1615506f1d07SSam Ravnborg
1616506f1d07SSam Ravnborgconfig ARCH_FLATMEM_ENABLE
1617506f1d07SSam Ravnborg	def_bool y
16183b16651fSTejun Heo	depends on X86_32 && !NUMA
1619506f1d07SSam Ravnborg
1620506f1d07SSam Ravnborgconfig ARCH_DISCONTIGMEM_ENABLE
1621506f1d07SSam Ravnborg	def_bool y
1622b263295dSChristoph Lameter	depends on NUMA && X86_32
1623506f1d07SSam Ravnborg
1624506f1d07SSam Ravnborgconfig ARCH_DISCONTIGMEM_DEFAULT
1625506f1d07SSam Ravnborg	def_bool y
1626b263295dSChristoph Lameter	depends on NUMA && X86_32
1627b263295dSChristoph Lameter
1628506f1d07SSam Ravnborgconfig ARCH_SPARSEMEM_ENABLE
1629506f1d07SSam Ravnborg	def_bool y
16306ea30386SKees Cook	depends on X86_64 || NUMA || X86_32 || X86_32_NON_STANDARD
1631506f1d07SSam Ravnborg	select SPARSEMEM_STATIC if X86_32
1632506f1d07SSam Ravnborg	select SPARSEMEM_VMEMMAP_ENABLE if X86_64
1633506f1d07SSam Ravnborg
16343b16651fSTejun Heoconfig ARCH_SPARSEMEM_DEFAULT
16353b16651fSTejun Heo	def_bool y
16363b16651fSTejun Heo	depends on X86_64
16373b16651fSTejun Heo
1638506f1d07SSam Ravnborgconfig ARCH_SELECT_MEMORY_MODEL
1639506f1d07SSam Ravnborg	def_bool y
1640b263295dSChristoph Lameter	depends on ARCH_SPARSEMEM_ENABLE
1641506f1d07SSam Ravnborg
1642506f1d07SSam Ravnborgconfig ARCH_MEMORY_PROBE
1643a0842b70SToshi Kani	bool "Enable sysfs memory/probe interface"
16443120e25eSJan Beulich	depends on X86_64 && MEMORY_HOTPLUG
1645a0842b70SToshi Kani	help
1646a0842b70SToshi Kani	  This option enables a sysfs memory/probe interface for testing.
1647a0842b70SToshi Kani	  See Documentation/memory-hotplug.txt for more information.
1648a0842b70SToshi Kani	  If you are unsure how to answer this question, answer N.
1649506f1d07SSam Ravnborg
16503b16651fSTejun Heoconfig ARCH_PROC_KCORE_TEXT
16513b16651fSTejun Heo	def_bool y
16523b16651fSTejun Heo	depends on X86_64 && PROC_KCORE
16533b16651fSTejun Heo
1654a29815a3SAvi Kivityconfig ILLEGAL_POINTER_VALUE
1655a29815a3SAvi Kivity       hex
1656a29815a3SAvi Kivity       default 0 if X86_32
1657a29815a3SAvi Kivity       default 0xdead000000000000 if X86_64
1658a29815a3SAvi Kivity
1659506f1d07SSam Ravnborgsource "mm/Kconfig"
1660506f1d07SSam Ravnborg
16617a67832cSDan Williamsconfig X86_PMEM_LEGACY_DEVICE
16627a67832cSDan Williams	bool
16637a67832cSDan Williams
1664ec776ef6SChristoph Hellwigconfig X86_PMEM_LEGACY
16657a67832cSDan Williams	tristate "Support non-standard NVDIMMs and ADR protected memory"
16669f53f9faSDan Williams	depends on PHYS_ADDR_T_64BIT
16679f53f9faSDan Williams	depends on BLK_DEV
16687a67832cSDan Williams	select X86_PMEM_LEGACY_DEVICE
16699f53f9faSDan Williams	select LIBNVDIMM
1670ec776ef6SChristoph Hellwig	help
1671ec776ef6SChristoph Hellwig	  Treat memory marked using the non-standard e820 type of 12 as used
1672ec776ef6SChristoph Hellwig	  by the Intel Sandy Bridge-EP reference BIOS as protected memory.
1673ec776ef6SChristoph Hellwig	  The kernel will offer these regions to the 'pmem' driver so
1674ec776ef6SChristoph Hellwig	  they can be used for persistent storage.
1675ec776ef6SChristoph Hellwig
1676ec776ef6SChristoph Hellwig	  Say Y if unsure.
1677ec776ef6SChristoph Hellwig
1678506f1d07SSam Ravnborgconfig HIGHPTE
1679506f1d07SSam Ravnborg	bool "Allocate 3rd-level pagetables from highmem"
16806fc108a0SJan Beulich	depends on HIGHMEM
16818f9ca475SIngo Molnar	---help---
1682506f1d07SSam Ravnborg	  The VM uses one page table entry for each page of physical memory.
1683506f1d07SSam Ravnborg	  For systems with a lot of RAM, this can be wasteful of precious
1684506f1d07SSam Ravnborg	  low memory.  Setting this option will put user-space page table
1685506f1d07SSam Ravnborg	  entries in high memory.
1686506f1d07SSam Ravnborg
16879f077871SJeremy Fitzhardingeconfig X86_CHECK_BIOS_CORRUPTION
16889f077871SJeremy Fitzhardinge	bool "Check for low memory corruption"
16898f9ca475SIngo Molnar	---help---
16909f077871SJeremy Fitzhardinge	  Periodically check for memory corruption in low memory, which
16919f077871SJeremy Fitzhardinge	  is suspected to be caused by BIOS.  Even when enabled in the
16929f077871SJeremy Fitzhardinge	  configuration, it is disabled at runtime.  Enable it by
16939f077871SJeremy Fitzhardinge	  setting "memory_corruption_check=1" on the kernel command
16949f077871SJeremy Fitzhardinge	  line.  By default it scans the low 64k of memory every 60
16959f077871SJeremy Fitzhardinge	  seconds; see the memory_corruption_check_size and
16969f077871SJeremy Fitzhardinge	  memory_corruption_check_period parameters in
16978c27ceffSMauro Carvalho Chehab	  Documentation/admin-guide/kernel-parameters.rst to adjust this.
16989f077871SJeremy Fitzhardinge
16999f077871SJeremy Fitzhardinge	  When enabled with the default parameters, this option has
17009f077871SJeremy Fitzhardinge	  almost no overhead, as it reserves a relatively small amount
17019f077871SJeremy Fitzhardinge	  of memory and scans it infrequently.  It both detects corruption
17029f077871SJeremy Fitzhardinge	  and prevents it from affecting the running system.
17039f077871SJeremy Fitzhardinge
17049f077871SJeremy Fitzhardinge	  It is, however, intended as a diagnostic tool; if repeatable
17059f077871SJeremy Fitzhardinge	  BIOS-originated corruption always affects the same memory,
17069f077871SJeremy Fitzhardinge	  you can use memmap= to prevent the kernel from using that
17079f077871SJeremy Fitzhardinge	  memory.
17089f077871SJeremy Fitzhardinge
1709c885df50SJeremy Fitzhardingeconfig X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK
1710c885df50SJeremy Fitzhardinge	bool "Set the default setting of memory_corruption_check"
1711c885df50SJeremy Fitzhardinge	depends on X86_CHECK_BIOS_CORRUPTION
1712c885df50SJeremy Fitzhardinge	default y
17138f9ca475SIngo Molnar	---help---
1714c885df50SJeremy Fitzhardinge	  Set whether the default state of memory_corruption_check is
1715c885df50SJeremy Fitzhardinge	  on or off.
1716c885df50SJeremy Fitzhardinge
17179ea77bdbSH. Peter Anvinconfig X86_RESERVE_LOW
1718d0cd7425SH. Peter Anvin	int "Amount of low memory, in kilobytes, to reserve for the BIOS"
1719d0cd7425SH. Peter Anvin	default 64
1720d0cd7425SH. Peter Anvin	range 4 640
17218f9ca475SIngo Molnar	---help---
1722d0cd7425SH. Peter Anvin	  Specify the amount of low memory to reserve for the BIOS.
1723fc381519SIngo Molnar
1724d0cd7425SH. Peter Anvin	  The first page contains BIOS data structures that the kernel
1725d0cd7425SH. Peter Anvin	  must not use, so that page must always be reserved.
1726fc381519SIngo Molnar
1727d0cd7425SH. Peter Anvin	  By default we reserve the first 64K of physical RAM, as a
1728d0cd7425SH. Peter Anvin	  number of BIOSes are known to corrupt that memory range
1729d0cd7425SH. Peter Anvin	  during events such as suspend/resume or monitor cable
1730d0cd7425SH. Peter Anvin	  insertion, so it must not be used by the kernel.
1731fc381519SIngo Molnar
1732d0cd7425SH. Peter Anvin	  You can set this to 4 if you are absolutely sure that you
1733d0cd7425SH. Peter Anvin	  trust the BIOS to get all its memory reservations and usages
1734d0cd7425SH. Peter Anvin	  right.  If you know your BIOS have problems beyond the
1735d0cd7425SH. Peter Anvin	  default 64K area, you can set this to 640 to avoid using the
1736d0cd7425SH. Peter Anvin	  entire low memory range.
1737d0cd7425SH. Peter Anvin
1738d0cd7425SH. Peter Anvin	  If you have doubts about the BIOS (e.g. suspend/resume does
1739d0cd7425SH. Peter Anvin	  not work or there's kernel crashes after certain hardware
1740d0cd7425SH. Peter Anvin	  hotplug events) then you might want to enable
1741d0cd7425SH. Peter Anvin	  X86_CHECK_BIOS_CORRUPTION=y to allow the kernel to check
1742d0cd7425SH. Peter Anvin	  typical corruption patterns.
1743d0cd7425SH. Peter Anvin
1744d0cd7425SH. Peter Anvin	  Leave this to the default value of 64 if you are unsure.
1745fc381519SIngo Molnar
1746506f1d07SSam Ravnborgconfig MATH_EMULATION
1747506f1d07SSam Ravnborg	bool
1748a5b9e5a2SAndy Lutomirski	depends on MODIFY_LDT_SYSCALL
1749506f1d07SSam Ravnborg	prompt "Math emulation" if X86_32
1750506f1d07SSam Ravnborg	---help---
1751506f1d07SSam Ravnborg	  Linux can emulate a math coprocessor (used for floating point
1752506f1d07SSam Ravnborg	  operations) if you don't have one. 486DX and Pentium processors have
1753506f1d07SSam Ravnborg	  a math coprocessor built in, 486SX and 386 do not, unless you added
1754506f1d07SSam Ravnborg	  a 487DX or 387, respectively. (The messages during boot time can
1755506f1d07SSam Ravnborg	  give you some hints here ["man dmesg"].) Everyone needs either a
1756506f1d07SSam Ravnborg	  coprocessor or this emulation.
1757506f1d07SSam Ravnborg
1758506f1d07SSam Ravnborg	  If you don't have a math coprocessor, you need to say Y here; if you
1759506f1d07SSam Ravnborg	  say Y here even though you have a coprocessor, the coprocessor will
1760506f1d07SSam Ravnborg	  be used nevertheless. (This behavior can be changed with the kernel
1761506f1d07SSam Ravnborg	  command line option "no387", which comes handy if your coprocessor
1762506f1d07SSam Ravnborg	  is broken. Try "man bootparam" or see the documentation of your boot
1763506f1d07SSam Ravnborg	  loader (lilo or loadlin) about how to pass options to the kernel at
1764506f1d07SSam Ravnborg	  boot time.) This means that it is a good idea to say Y here if you
1765506f1d07SSam Ravnborg	  intend to use this kernel on different machines.
1766506f1d07SSam Ravnborg
1767506f1d07SSam Ravnborg	  More information about the internals of the Linux math coprocessor
1768506f1d07SSam Ravnborg	  emulation can be found in <file:arch/x86/math-emu/README>.
1769506f1d07SSam Ravnborg
1770506f1d07SSam Ravnborg	  If you are not sure, say Y; apart from resulting in a 66 KB bigger
1771506f1d07SSam Ravnborg	  kernel, it won't hurt.
1772506f1d07SSam Ravnborg
1773506f1d07SSam Ravnborgconfig MTRR
17746fc108a0SJan Beulich	def_bool y
17756a108a14SDavid Rientjes	prompt "MTRR (Memory Type Range Register) support" if EXPERT
1776506f1d07SSam Ravnborg	---help---
1777506f1d07SSam Ravnborg	  On Intel P6 family processors (Pentium Pro, Pentium II and later)
1778506f1d07SSam Ravnborg	  the Memory Type Range Registers (MTRRs) may be used to control
1779506f1d07SSam Ravnborg	  processor access to memory ranges. This is most useful if you have
1780506f1d07SSam Ravnborg	  a video (VGA) card on a PCI or AGP bus. Enabling write-combining
1781506f1d07SSam Ravnborg	  allows bus write transfers to be combined into a larger transfer
1782506f1d07SSam Ravnborg	  before bursting over the PCI/AGP bus. This can increase performance
1783506f1d07SSam Ravnborg	  of image write operations 2.5 times or more. Saying Y here creates a
1784506f1d07SSam Ravnborg	  /proc/mtrr file which may be used to manipulate your processor's
1785506f1d07SSam Ravnborg	  MTRRs. Typically the X server should use this.
1786506f1d07SSam Ravnborg
1787506f1d07SSam Ravnborg	  This code has a reasonably generic interface so that similar
1788506f1d07SSam Ravnborg	  control registers on other processors can be easily supported
1789506f1d07SSam Ravnborg	  as well:
1790506f1d07SSam Ravnborg
1791506f1d07SSam Ravnborg	  The Cyrix 6x86, 6x86MX and M II processors have Address Range
1792506f1d07SSam Ravnborg	  Registers (ARRs) which provide a similar functionality to MTRRs. For
1793506f1d07SSam Ravnborg	  these, the ARRs are used to emulate the MTRRs.
1794506f1d07SSam Ravnborg	  The AMD K6-2 (stepping 8 and above) and K6-3 processors have two
1795506f1d07SSam Ravnborg	  MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing
1796506f1d07SSam Ravnborg	  write-combining. All of these processors are supported by this code
1797506f1d07SSam Ravnborg	  and it makes sense to say Y here if you have one of them.
1798506f1d07SSam Ravnborg
1799506f1d07SSam Ravnborg	  Saying Y here also fixes a problem with buggy SMP BIOSes which only
1800506f1d07SSam Ravnborg	  set the MTRRs for the boot CPU and not for the secondary CPUs. This
1801506f1d07SSam Ravnborg	  can lead to all sorts of problems, so it's good to say Y here.
1802506f1d07SSam Ravnborg
1803506f1d07SSam Ravnborg	  You can safely say Y even if your machine doesn't have MTRRs, you'll
1804506f1d07SSam Ravnborg	  just add about 9 KB to your kernel.
1805506f1d07SSam Ravnborg
18067225e751SRandy Dunlap	  See <file:Documentation/x86/mtrr.txt> for more information.
1807506f1d07SSam Ravnborg
180895ffa243SYinghai Luconfig MTRR_SANITIZER
18092ffb3501SYinghai Lu	def_bool y
181095ffa243SYinghai Lu	prompt "MTRR cleanup support"
181195ffa243SYinghai Lu	depends on MTRR
18128f9ca475SIngo Molnar	---help---
1813aba3728cSThomas Gleixner	  Convert MTRR layout from continuous to discrete, so X drivers can
1814aba3728cSThomas Gleixner	  add writeback entries.
181595ffa243SYinghai Lu
1816aba3728cSThomas Gleixner	  Can be disabled with disable_mtrr_cleanup on the kernel command line.
1817692105b8SMatt LaPlante	  The largest mtrr entry size for a continuous block can be set with
1818aba3728cSThomas Gleixner	  mtrr_chunk_size.
181995ffa243SYinghai Lu
18202ffb3501SYinghai Lu	  If unsure, say Y.
182195ffa243SYinghai Lu
182295ffa243SYinghai Luconfig MTRR_SANITIZER_ENABLE_DEFAULT
1823f5098d62SYinghai Lu	int "MTRR cleanup enable value (0-1)"
1824f5098d62SYinghai Lu	range 0 1
1825f5098d62SYinghai Lu	default "0"
182695ffa243SYinghai Lu	depends on MTRR_SANITIZER
18278f9ca475SIngo Molnar	---help---
1828f5098d62SYinghai Lu	  Enable mtrr cleanup default value
182995ffa243SYinghai Lu
183012031a62SYinghai Luconfig MTRR_SANITIZER_SPARE_REG_NR_DEFAULT
183112031a62SYinghai Lu	int "MTRR cleanup spare reg num (0-7)"
183212031a62SYinghai Lu	range 0 7
183312031a62SYinghai Lu	default "1"
183412031a62SYinghai Lu	depends on MTRR_SANITIZER
18358f9ca475SIngo Molnar	---help---
183612031a62SYinghai Lu	  mtrr cleanup spare entries default, it can be changed via
1837aba3728cSThomas Gleixner	  mtrr_spare_reg_nr=N on the kernel command line.
183812031a62SYinghai Lu
18392e5d9c85Svenkatesh.pallipadi@intel.comconfig X86_PAT
18406fc108a0SJan Beulich	def_bool y
18416a108a14SDavid Rientjes	prompt "x86 PAT support" if EXPERT
18422a8a2719SIngo Molnar	depends on MTRR
18438f9ca475SIngo Molnar	---help---
18442e5d9c85Svenkatesh.pallipadi@intel.com	  Use PAT attributes to setup page level cache control.
1845042b78e4SVenki Pallipadi
18462e5d9c85Svenkatesh.pallipadi@intel.com	  PATs are the modern equivalents of MTRRs and are much more
18472e5d9c85Svenkatesh.pallipadi@intel.com	  flexible than MTRRs.
18482e5d9c85Svenkatesh.pallipadi@intel.com
18492e5d9c85Svenkatesh.pallipadi@intel.com	  Say N here if you see bootup problems (boot crash, boot hang,
1850042b78e4SVenki Pallipadi	  spontaneous reboots) or a non-working video driver.
18512e5d9c85Svenkatesh.pallipadi@intel.com
18522e5d9c85Svenkatesh.pallipadi@intel.com	  If unsure, say Y.
18532e5d9c85Svenkatesh.pallipadi@intel.com
185446cf98cdSVenkatesh Pallipadiconfig ARCH_USES_PG_UNCACHED
185546cf98cdSVenkatesh Pallipadi	def_bool y
185646cf98cdSVenkatesh Pallipadi	depends on X86_PAT
185746cf98cdSVenkatesh Pallipadi
1858628c6246SH. Peter Anvinconfig ARCH_RANDOM
1859628c6246SH. Peter Anvin	def_bool y
1860628c6246SH. Peter Anvin	prompt "x86 architectural random number generator" if EXPERT
1861628c6246SH. Peter Anvin	---help---
1862628c6246SH. Peter Anvin	  Enable the x86 architectural RDRAND instruction
1863628c6246SH. Peter Anvin	  (Intel Bull Mountain technology) to generate random numbers.
1864628c6246SH. Peter Anvin	  If supported, this is a high bandwidth, cryptographically
1865628c6246SH. Peter Anvin	  secure hardware random number generator.
1866628c6246SH. Peter Anvin
186751ae4a2dSH. Peter Anvinconfig X86_SMAP
186851ae4a2dSH. Peter Anvin	def_bool y
186951ae4a2dSH. Peter Anvin	prompt "Supervisor Mode Access Prevention" if EXPERT
187051ae4a2dSH. Peter Anvin	---help---
187151ae4a2dSH. Peter Anvin	  Supervisor Mode Access Prevention (SMAP) is a security
187251ae4a2dSH. Peter Anvin	  feature in newer Intel processors.  There is a small
187351ae4a2dSH. Peter Anvin	  performance cost if this enabled and turned on; there is
187451ae4a2dSH. Peter Anvin	  also a small increase in the kernel size if this is enabled.
187551ae4a2dSH. Peter Anvin
187651ae4a2dSH. Peter Anvin	  If unsure, say Y.
187751ae4a2dSH. Peter Anvin
1878aa35f896SRicardo Nericonfig X86_INTEL_UMIP
1879796ebc81SRicardo Neri	def_bool y
1880aa35f896SRicardo Neri	depends on CPU_SUP_INTEL
1881aa35f896SRicardo Neri	prompt "Intel User Mode Instruction Prevention" if EXPERT
1882aa35f896SRicardo Neri	---help---
1883aa35f896SRicardo Neri	  The User Mode Instruction Prevention (UMIP) is a security
1884aa35f896SRicardo Neri	  feature in newer Intel processors. If enabled, a general
1885796ebc81SRicardo Neri	  protection fault is issued if the SGDT, SLDT, SIDT, SMSW
1886796ebc81SRicardo Neri	  or STR instructions are executed in user mode. These instructions
1887796ebc81SRicardo Neri	  unnecessarily expose information about the hardware state.
1888796ebc81SRicardo Neri
1889796ebc81SRicardo Neri	  The vast majority of applications do not use these instructions.
1890796ebc81SRicardo Neri	  For the very few that do, software emulation is provided in
1891796ebc81SRicardo Neri	  specific cases in protected and virtual-8086 modes. Emulated
1892796ebc81SRicardo Neri	  results are dummy.
1893aa35f896SRicardo Neri
189472e9b5feSDave Hansenconfig X86_INTEL_MPX
189572e9b5feSDave Hansen	prompt "Intel MPX (Memory Protection Extensions)"
189672e9b5feSDave Hansen	def_bool n
1897df3735c5SRik van Riel	# Note: only available in 64-bit mode due to VMA flags shortage
1898df3735c5SRik van Riel	depends on CPU_SUP_INTEL && X86_64
1899df3735c5SRik van Riel	select ARCH_USES_HIGH_VMA_FLAGS
190072e9b5feSDave Hansen	---help---
190172e9b5feSDave Hansen	  MPX provides hardware features that can be used in
190272e9b5feSDave Hansen	  conjunction with compiler-instrumented code to check
190372e9b5feSDave Hansen	  memory references.  It is designed to detect buffer
190472e9b5feSDave Hansen	  overflow or underflow bugs.
190572e9b5feSDave Hansen
190672e9b5feSDave Hansen	  This option enables running applications which are
190772e9b5feSDave Hansen	  instrumented or otherwise use MPX.  It does not use MPX
190872e9b5feSDave Hansen	  itself inside the kernel or to protect the kernel
190972e9b5feSDave Hansen	  against bad memory references.
191072e9b5feSDave Hansen
191172e9b5feSDave Hansen	  Enabling this option will make the kernel larger:
191272e9b5feSDave Hansen	  ~8k of kernel text and 36 bytes of data on a 64-bit
191372e9b5feSDave Hansen	  defconfig.  It adds a long to the 'mm_struct' which
191472e9b5feSDave Hansen	  will increase the kernel memory overhead of each
191572e9b5feSDave Hansen	  process and adds some branches to paths used during
191672e9b5feSDave Hansen	  exec() and munmap().
191772e9b5feSDave Hansen
191872e9b5feSDave Hansen	  For details, see Documentation/x86/intel_mpx.txt
191972e9b5feSDave Hansen
192072e9b5feSDave Hansen	  If unsure, say N.
192172e9b5feSDave Hansen
192235e97790SDave Hansenconfig X86_INTEL_MEMORY_PROTECTION_KEYS
1923284244a9SDave Hansen	prompt "Intel Memory Protection Keys"
192435e97790SDave Hansen	def_bool y
1925284244a9SDave Hansen	# Note: only available in 64-bit mode
192635e97790SDave Hansen	depends on CPU_SUP_INTEL && X86_64
192752c8e601SIngo Molnar	select ARCH_USES_HIGH_VMA_FLAGS
192852c8e601SIngo Molnar	select ARCH_HAS_PKEYS
1929284244a9SDave Hansen	---help---
1930284244a9SDave Hansen	  Memory Protection Keys provides a mechanism for enforcing
1931284244a9SDave Hansen	  page-based protections, but without requiring modification of the
1932284244a9SDave Hansen	  page tables when an application changes protection domains.
1933284244a9SDave Hansen
1934284244a9SDave Hansen	  For details, see Documentation/x86/protection-keys.txt
1935284244a9SDave Hansen
1936284244a9SDave Hansen	  If unsure, say y.
193735e97790SDave Hansen
1938506f1d07SSam Ravnborgconfig EFI
19399ba16087SJan Beulich	bool "EFI runtime service support"
19405b83683fSHuang, Ying	depends on ACPI
1941f6ce5002SSergey Vlasov	select UCS2_STRING
1942022ee6c5SArd Biesheuvel	select EFI_RUNTIME_WRAPPERS
1943506f1d07SSam Ravnborg	---help---
19448b2cb7a8SHuang, Ying	  This enables the kernel to use EFI runtime services that are
1945506f1d07SSam Ravnborg	  available (such as the EFI variable services).
1946506f1d07SSam Ravnborg
19478b2cb7a8SHuang, Ying	  This option is only useful on systems that have EFI firmware.
19488b2cb7a8SHuang, Ying	  In addition, you should use the latest ELILO loader available
19498b2cb7a8SHuang, Ying	  at <http://elilo.sourceforge.net> in order to take advantage
19508b2cb7a8SHuang, Ying	  of EFI runtime services. However, even with this option, the
19518b2cb7a8SHuang, Ying	  resultant kernel should continue to boot on existing non-EFI
19528b2cb7a8SHuang, Ying	  platforms.
1953506f1d07SSam Ravnborg
1954291f3632SMatt Flemingconfig EFI_STUB
1955291f3632SMatt Fleming       bool "EFI stub support"
1956b16d8c23SMatt Fleming       depends on EFI && !X86_USE_3DNOW
19577b2a583aSMatt Fleming       select RELOCATABLE
1958291f3632SMatt Fleming       ---help---
1959291f3632SMatt Fleming          This kernel feature allows a bzImage to be loaded directly
1960291f3632SMatt Fleming	  by EFI firmware without the use of a bootloader.
1961291f3632SMatt Fleming
19624172fe2fSRoy Franz	  See Documentation/efi-stub.txt for more information.
19630c759662SMatt Fleming
19647d453eeeSMatt Flemingconfig EFI_MIXED
19657d453eeeSMatt Fleming	bool "EFI mixed-mode support"
19667d453eeeSMatt Fleming	depends on EFI_STUB && X86_64
19677d453eeeSMatt Fleming	---help---
19687d453eeeSMatt Fleming	   Enabling this feature allows a 64-bit kernel to be booted
19697d453eeeSMatt Fleming	   on a 32-bit firmware, provided that your CPU supports 64-bit
19707d453eeeSMatt Fleming	   mode.
19717d453eeeSMatt Fleming
19727d453eeeSMatt Fleming	   Note that it is not possible to boot a mixed-mode enabled
19737d453eeeSMatt Fleming	   kernel via the EFI boot stub - a bootloader that supports
19747d453eeeSMatt Fleming	   the EFI handover protocol must be used.
19757d453eeeSMatt Fleming
19767d453eeeSMatt Fleming	   If unsure, say N.
19777d453eeeSMatt Fleming
1978506f1d07SSam Ravnborgconfig SECCOMP
19793c2362e6SHarvey Harrison	def_bool y
19803c2362e6SHarvey Harrison	prompt "Enable seccomp to safely compute untrusted bytecode"
19818f9ca475SIngo Molnar	---help---
1982506f1d07SSam Ravnborg	  This kernel feature is useful for number crunching applications
1983506f1d07SSam Ravnborg	  that may need to compute untrusted bytecode during their
1984506f1d07SSam Ravnborg	  execution. By using pipes or other transports made available to
1985506f1d07SSam Ravnborg	  the process as file descriptors supporting the read/write
1986506f1d07SSam Ravnborg	  syscalls, it's possible to isolate those applications in
1987506f1d07SSam Ravnborg	  their own address space using seccomp. Once seccomp is
19889c0bbee8SAlexey Dobriyan	  enabled via prctl(PR_SET_SECCOMP), it cannot be disabled
1989506f1d07SSam Ravnborg	  and the task is only allowed to execute a few safe syscalls
1990506f1d07SSam Ravnborg	  defined by each seccomp mode.
1991506f1d07SSam Ravnborg
1992506f1d07SSam Ravnborg	  If unsure, say Y. Only embedded should say N here.
1993506f1d07SSam Ravnborg
1994506f1d07SSam Ravnborgsource kernel/Kconfig.hz
1995506f1d07SSam Ravnborg
1996506f1d07SSam Ravnborgconfig KEXEC
1997506f1d07SSam Ravnborg	bool "kexec system call"
19982965faa5SDave Young	select KEXEC_CORE
19998f9ca475SIngo Molnar	---help---
2000506f1d07SSam Ravnborg	  kexec is a system call that implements the ability to shutdown your
2001506f1d07SSam Ravnborg	  current kernel, and to start another kernel.  It is like a reboot
2002506f1d07SSam Ravnborg	  but it is independent of the system firmware.   And like a reboot
2003506f1d07SSam Ravnborg	  you can start any kernel with it, not just Linux.
2004506f1d07SSam Ravnborg
2005506f1d07SSam Ravnborg	  The name comes from the similarity to the exec system call.
2006506f1d07SSam Ravnborg
2007506f1d07SSam Ravnborg	  It is an ongoing process to be certain the hardware in a machine
2008506f1d07SSam Ravnborg	  is properly shutdown, so do not be surprised if this code does not
2009bf220695SGeert Uytterhoeven	  initially work for you.  As of this writing the exact hardware
2010bf220695SGeert Uytterhoeven	  interface is strongly in flux, so no good recommendation can be
2011bf220695SGeert Uytterhoeven	  made.
2012506f1d07SSam Ravnborg
201374ca317cSVivek Goyalconfig KEXEC_FILE
201474ca317cSVivek Goyal	bool "kexec file based system call"
20152965faa5SDave Young	select KEXEC_CORE
201674ca317cSVivek Goyal	select BUILD_BIN2C
201774ca317cSVivek Goyal	depends on X86_64
201874ca317cSVivek Goyal	depends on CRYPTO=y
201974ca317cSVivek Goyal	depends on CRYPTO_SHA256=y
202074ca317cSVivek Goyal	---help---
202174ca317cSVivek Goyal	  This is new version of kexec system call. This system call is
202274ca317cSVivek Goyal	  file based and takes file descriptors as system call argument
202374ca317cSVivek Goyal	  for kernel and initramfs as opposed to list of segments as
202474ca317cSVivek Goyal	  accepted by previous system call.
202574ca317cSVivek Goyal
20268e7d8381SVivek Goyalconfig KEXEC_VERIFY_SIG
20278e7d8381SVivek Goyal	bool "Verify kernel signature during kexec_file_load() syscall"
202874ca317cSVivek Goyal	depends on KEXEC_FILE
20298e7d8381SVivek Goyal	---help---
20308e7d8381SVivek Goyal	  This option makes kernel signature verification mandatory for
2031d8eb8940SBorislav Petkov	  the kexec_file_load() syscall.
20328e7d8381SVivek Goyal
2033d8eb8940SBorislav Petkov	  In addition to that option, you need to enable signature
2034d8eb8940SBorislav Petkov	  verification for the corresponding kernel image type being
2035d8eb8940SBorislav Petkov	  loaded in order for this to work.
20368e7d8381SVivek Goyal
20378e7d8381SVivek Goyalconfig KEXEC_BZIMAGE_VERIFY_SIG
20388e7d8381SVivek Goyal	bool "Enable bzImage signature verification support"
20398e7d8381SVivek Goyal	depends on KEXEC_VERIFY_SIG
20408e7d8381SVivek Goyal	depends on SIGNED_PE_FILE_VERIFICATION
20418e7d8381SVivek Goyal	select SYSTEM_TRUSTED_KEYRING
20428e7d8381SVivek Goyal	---help---
20438e7d8381SVivek Goyal	  Enable bzImage signature verification support.
20448e7d8381SVivek Goyal
2045506f1d07SSam Ravnborgconfig CRASH_DUMP
204604b69447SPavel Machek	bool "kernel crash dumps"
2047506f1d07SSam Ravnborg	depends on X86_64 || (X86_32 && HIGHMEM)
20488f9ca475SIngo Molnar	---help---
2049506f1d07SSam Ravnborg	  Generate crash dump after being started by kexec.
2050506f1d07SSam Ravnborg	  This should be normally only set in special crash dump kernels
2051506f1d07SSam Ravnborg	  which are loaded in the main kernel with kexec-tools into
2052506f1d07SSam Ravnborg	  a specially reserved region and then later executed after
2053506f1d07SSam Ravnborg	  a crash by kdump/kexec. The crash dump kernel must be compiled
2054506f1d07SSam Ravnborg	  to a memory address not used by the main kernel or BIOS using
2055506f1d07SSam Ravnborg	  PHYSICAL_START, or it must be built as a relocatable image
2056506f1d07SSam Ravnborg	  (CONFIG_RELOCATABLE=y).
2057506f1d07SSam Ravnborg	  For more details see Documentation/kdump/kdump.txt
2058506f1d07SSam Ravnborg
20593ab83521SHuang Yingconfig KEXEC_JUMP
20606ea30386SKees Cook	bool "kexec jump"
2061fee7b0d8SHuang Ying	depends on KEXEC && HIBERNATION
20628f9ca475SIngo Molnar	---help---
206389081d17SHuang Ying	  Jump between original kernel and kexeced kernel and invoke
206489081d17SHuang Ying	  code in physical address mode via KEXEC
20653ab83521SHuang Ying
2066506f1d07SSam Ravnborgconfig PHYSICAL_START
20676a108a14SDavid Rientjes	hex "Physical address where the kernel is loaded" if (EXPERT || CRASH_DUMP)
2068ceefccc9SH. Peter Anvin	default "0x1000000"
20698f9ca475SIngo Molnar	---help---
2070506f1d07SSam Ravnborg	  This gives the physical address where the kernel is loaded.
2071506f1d07SSam Ravnborg
2072506f1d07SSam Ravnborg	  If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then
2073506f1d07SSam Ravnborg	  bzImage will decompress itself to above physical address and
2074506f1d07SSam Ravnborg	  run from there. Otherwise, bzImage will run from the address where
2075506f1d07SSam Ravnborg	  it has been loaded by the boot loader and will ignore above physical
2076506f1d07SSam Ravnborg	  address.
2077506f1d07SSam Ravnborg
2078506f1d07SSam Ravnborg	  In normal kdump cases one does not have to set/change this option
2079506f1d07SSam Ravnborg	  as now bzImage can be compiled as a completely relocatable image
2080506f1d07SSam Ravnborg	  (CONFIG_RELOCATABLE=y) and be used to load and run from a different
2081506f1d07SSam Ravnborg	  address. This option is mainly useful for the folks who don't want
2082506f1d07SSam Ravnborg	  to use a bzImage for capturing the crash dump and want to use a
2083506f1d07SSam Ravnborg	  vmlinux instead. vmlinux is not relocatable hence a kernel needs
2084506f1d07SSam Ravnborg	  to be specifically compiled to run from a specific memory area
2085506f1d07SSam Ravnborg	  (normally a reserved region) and this option comes handy.
2086506f1d07SSam Ravnborg
2087ceefccc9SH. Peter Anvin	  So if you are using bzImage for capturing the crash dump,
2088ceefccc9SH. Peter Anvin	  leave the value here unchanged to 0x1000000 and set
2089ceefccc9SH. Peter Anvin	  CONFIG_RELOCATABLE=y.  Otherwise if you plan to use vmlinux
2090ceefccc9SH. Peter Anvin	  for capturing the crash dump change this value to start of
2091ceefccc9SH. Peter Anvin	  the reserved region.  In other words, it can be set based on
2092ceefccc9SH. Peter Anvin	  the "X" value as specified in the "crashkernel=YM@XM"
2093ceefccc9SH. Peter Anvin	  command line boot parameter passed to the panic-ed
2094ceefccc9SH. Peter Anvin	  kernel. Please take a look at Documentation/kdump/kdump.txt
2095ceefccc9SH. Peter Anvin	  for more details about crash dumps.
2096506f1d07SSam Ravnborg
2097506f1d07SSam Ravnborg	  Usage of bzImage for capturing the crash dump is recommended as
2098506f1d07SSam Ravnborg	  one does not have to build two kernels. Same kernel can be used
2099506f1d07SSam Ravnborg	  as production kernel and capture kernel. Above option should have
2100506f1d07SSam Ravnborg	  gone away after relocatable bzImage support is introduced. But it
2101506f1d07SSam Ravnborg	  is present because there are users out there who continue to use
2102506f1d07SSam Ravnborg	  vmlinux for dump capture. This option should go away down the
2103506f1d07SSam Ravnborg	  line.
2104506f1d07SSam Ravnborg
2105506f1d07SSam Ravnborg	  Don't change this unless you know what you are doing.
2106506f1d07SSam Ravnborg
2107506f1d07SSam Ravnborgconfig RELOCATABLE
210826717808SH. Peter Anvin	bool "Build a relocatable kernel"
210926717808SH. Peter Anvin	default y
21108f9ca475SIngo Molnar	---help---
2111506f1d07SSam Ravnborg	  This builds a kernel image that retains relocation information
2112506f1d07SSam Ravnborg	  so it can be loaded someplace besides the default 1MB.
2113506f1d07SSam Ravnborg	  The relocations tend to make the kernel binary about 10% larger,
2114506f1d07SSam Ravnborg	  but are discarded at runtime.
2115506f1d07SSam Ravnborg
2116506f1d07SSam Ravnborg	  One use is for the kexec on panic case where the recovery kernel
2117506f1d07SSam Ravnborg	  must live at a different physical address than the primary
2118506f1d07SSam Ravnborg	  kernel.
2119506f1d07SSam Ravnborg
2120506f1d07SSam Ravnborg	  Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address
2121506f1d07SSam Ravnborg	  it has been loaded at and the compile time physical address
21228ab3820fSKees Cook	  (CONFIG_PHYSICAL_START) is used as the minimum location.
2123506f1d07SSam Ravnborg
21248ab3820fSKees Cookconfig RANDOMIZE_BASE
2125e8581e3dSBaoquan He	bool "Randomize the address of the kernel image (KASLR)"
21268ab3820fSKees Cook	depends on RELOCATABLE
21276807c846SIngo Molnar	default y
21288ab3820fSKees Cook	---help---
2129e8581e3dSBaoquan He	  In support of Kernel Address Space Layout Randomization (KASLR),
2130e8581e3dSBaoquan He	  this randomizes the physical address at which the kernel image
2131e8581e3dSBaoquan He	  is decompressed and the virtual address where the kernel
2132e8581e3dSBaoquan He	  image is mapped, as a security feature that deters exploit
2133e8581e3dSBaoquan He	  attempts relying on knowledge of the location of kernel
2134e8581e3dSBaoquan He	  code internals.
2135e8581e3dSBaoquan He
2136ed9f007eSKees Cook	  On 64-bit, the kernel physical and virtual addresses are
2137ed9f007eSKees Cook	  randomized separately. The physical address will be anywhere
2138ed9f007eSKees Cook	  between 16MB and the top of physical memory (up to 64TB). The
2139ed9f007eSKees Cook	  virtual address will be randomized from 16MB up to 1GB (9 bits
2140ed9f007eSKees Cook	  of entropy). Note that this also reduces the memory space
2141ed9f007eSKees Cook	  available to kernel modules from 1.5GB to 1GB.
2142ed9f007eSKees Cook
2143ed9f007eSKees Cook	  On 32-bit, the kernel physical and virtual addresses are
2144ed9f007eSKees Cook	  randomized together. They will be randomized from 16MB up to
2145ed9f007eSKees Cook	  512MB (8 bits of entropy).
21468ab3820fSKees Cook
2147a653f356SKees Cook	  Entropy is generated using the RDRAND instruction if it is
2148e8581e3dSBaoquan He	  supported. If RDTSC is supported, its value is mixed into
2149e8581e3dSBaoquan He	  the entropy pool as well. If neither RDRAND nor RDTSC are
2150ed9f007eSKees Cook	  supported, then entropy is read from the i8254 timer. The
2151ed9f007eSKees Cook	  usable entropy is limited by the kernel being built using
2152ed9f007eSKees Cook	  2GB addressing, and that PHYSICAL_ALIGN must be at a
2153ed9f007eSKees Cook	  minimum of 2MB. As a result, only 10 bits of entropy are
2154ed9f007eSKees Cook	  theoretically possible, but the implementations are further
2155ed9f007eSKees Cook	  limited due to memory layouts.
2156e8581e3dSBaoquan He
21576807c846SIngo Molnar	  If unsure, say Y.
2158da2b6fb9SKees Cook
21598ab3820fSKees Cook# Relocation on x86 needs some additional build support
2160845adf72SH. Peter Anvinconfig X86_NEED_RELOCS
2161845adf72SH. Peter Anvin	def_bool y
21628ab3820fSKees Cook	depends on RANDOMIZE_BASE || (X86_32 && RELOCATABLE)
2163845adf72SH. Peter Anvin
2164506f1d07SSam Ravnborgconfig PHYSICAL_ALIGN
2165a0215061SKees Cook	hex "Alignment value to which kernel should be aligned"
21668ab3820fSKees Cook	default "0x200000"
2167a0215061SKees Cook	range 0x2000 0x1000000 if X86_32
2168a0215061SKees Cook	range 0x200000 0x1000000 if X86_64
21698f9ca475SIngo Molnar	---help---
2170506f1d07SSam Ravnborg	  This value puts the alignment restrictions on physical address
2171506f1d07SSam Ravnborg	  where kernel is loaded and run from. Kernel is compiled for an
2172506f1d07SSam Ravnborg	  address which meets above alignment restriction.
2173506f1d07SSam Ravnborg
2174506f1d07SSam Ravnborg	  If bootloader loads the kernel at a non-aligned address and
2175506f1d07SSam Ravnborg	  CONFIG_RELOCATABLE is set, kernel will move itself to nearest
2176506f1d07SSam Ravnborg	  address aligned to above value and run from there.
2177506f1d07SSam Ravnborg
2178506f1d07SSam Ravnborg	  If bootloader loads the kernel at a non-aligned address and
2179506f1d07SSam Ravnborg	  CONFIG_RELOCATABLE is not set, kernel will ignore the run time
2180506f1d07SSam Ravnborg	  load address and decompress itself to the address it has been
2181506f1d07SSam Ravnborg	  compiled for and run from there. The address for which kernel is
2182506f1d07SSam Ravnborg	  compiled already meets above alignment restrictions. Hence the
2183506f1d07SSam Ravnborg	  end result is that kernel runs from a physical address meeting
2184506f1d07SSam Ravnborg	  above alignment restrictions.
2185506f1d07SSam Ravnborg
2186a0215061SKees Cook	  On 32-bit this value must be a multiple of 0x2000. On 64-bit
2187a0215061SKees Cook	  this value must be a multiple of 0x200000.
2188a0215061SKees Cook
2189506f1d07SSam Ravnborg	  Don't change this unless you know what you are doing.
2190506f1d07SSam Ravnborg
2191eedb92abSKirill A. Shutemovconfig DYNAMIC_MEMORY_LAYOUT
2192eedb92abSKirill A. Shutemov	bool
2193eedb92abSKirill A. Shutemov	---help---
2194eedb92abSKirill A. Shutemov	  This option makes base addresses of vmalloc and vmemmap as well as
2195eedb92abSKirill A. Shutemov	  __PAGE_OFFSET movable during boot.
2196eedb92abSKirill A. Shutemov
21970483e1faSThomas Garnierconfig RANDOMIZE_MEMORY
21980483e1faSThomas Garnier	bool "Randomize the kernel memory sections"
21990483e1faSThomas Garnier	depends on X86_64
22000483e1faSThomas Garnier	depends on RANDOMIZE_BASE
2201eedb92abSKirill A. Shutemov	select DYNAMIC_MEMORY_LAYOUT
22020483e1faSThomas Garnier	default RANDOMIZE_BASE
22030483e1faSThomas Garnier	---help---
22040483e1faSThomas Garnier	   Randomizes the base virtual address of kernel memory sections
22050483e1faSThomas Garnier	   (physical memory mapping, vmalloc & vmemmap). This security feature
22060483e1faSThomas Garnier	   makes exploits relying on predictable memory locations less reliable.
22070483e1faSThomas Garnier
22080483e1faSThomas Garnier	   The order of allocations remains unchanged. Entropy is generated in
22090483e1faSThomas Garnier	   the same way as RANDOMIZE_BASE. Current implementation in the optimal
22100483e1faSThomas Garnier	   configuration have in average 30,000 different possible virtual
22110483e1faSThomas Garnier	   addresses for each memory section.
22120483e1faSThomas Garnier
22136807c846SIngo Molnar	   If unsure, say Y.
22140483e1faSThomas Garnier
221590397a41SThomas Garnierconfig RANDOMIZE_MEMORY_PHYSICAL_PADDING
221690397a41SThomas Garnier	hex "Physical memory mapping padding" if EXPERT
221790397a41SThomas Garnier	depends on RANDOMIZE_MEMORY
221890397a41SThomas Garnier	default "0xa" if MEMORY_HOTPLUG
221990397a41SThomas Garnier	default "0x0"
222090397a41SThomas Garnier	range 0x1 0x40 if MEMORY_HOTPLUG
222190397a41SThomas Garnier	range 0x0 0x40
222290397a41SThomas Garnier	---help---
222390397a41SThomas Garnier	   Define the padding in terabytes added to the existing physical
222490397a41SThomas Garnier	   memory size during kernel memory randomization. It is useful
222590397a41SThomas Garnier	   for memory hotplug support but reduces the entropy available for
222690397a41SThomas Garnier	   address randomization.
222790397a41SThomas Garnier
222890397a41SThomas Garnier	   If unsure, leave at the default value.
222990397a41SThomas Garnier
2230506f1d07SSam Ravnborgconfig HOTPLUG_CPU
22317c13e6a3SDimitri Sivanich	bool "Support for hot-pluggable CPUs"
223240b31360SStephen Rothwell	depends on SMP
2233506f1d07SSam Ravnborg	---help---
22347c13e6a3SDimitri Sivanich	  Say Y here to allow turning CPUs off and on. CPUs can be
22357c13e6a3SDimitri Sivanich	  controlled through /sys/devices/system/cpu.
22367c13e6a3SDimitri Sivanich	  ( Note: power management support will enable this option
22377c13e6a3SDimitri Sivanich	    automatically on SMP systems. )
22387c13e6a3SDimitri Sivanich	  Say N if you want to disable CPU hotplug.
2239506f1d07SSam Ravnborg
224080aa1dffSFenghua Yuconfig BOOTPARAM_HOTPLUG_CPU0
224180aa1dffSFenghua Yu	bool "Set default setting of cpu0_hotpluggable"
224280aa1dffSFenghua Yu	default n
22432c922cd0SKees Cook	depends on HOTPLUG_CPU
224480aa1dffSFenghua Yu	---help---
224580aa1dffSFenghua Yu	  Set whether default state of cpu0_hotpluggable is on or off.
224680aa1dffSFenghua Yu
224780aa1dffSFenghua Yu	  Say Y here to enable CPU0 hotplug by default. If this switch
224880aa1dffSFenghua Yu	  is turned on, there is no need to give cpu0_hotplug kernel
224980aa1dffSFenghua Yu	  parameter and the CPU0 hotplug feature is enabled by default.
225080aa1dffSFenghua Yu
225180aa1dffSFenghua Yu	  Please note: there are two known CPU0 dependencies if you want
225280aa1dffSFenghua Yu	  to enable the CPU0 hotplug feature either by this switch or by
225380aa1dffSFenghua Yu	  cpu0_hotplug kernel parameter.
225480aa1dffSFenghua Yu
225580aa1dffSFenghua Yu	  First, resume from hibernate or suspend always starts from CPU0.
225680aa1dffSFenghua Yu	  So hibernate and suspend are prevented if CPU0 is offline.
225780aa1dffSFenghua Yu
225880aa1dffSFenghua Yu	  Second dependency is PIC interrupts always go to CPU0. CPU0 can not
225980aa1dffSFenghua Yu	  offline if any interrupt can not migrate out of CPU0. There may
226080aa1dffSFenghua Yu	  be other CPU0 dependencies.
226180aa1dffSFenghua Yu
226280aa1dffSFenghua Yu	  Please make sure the dependencies are under your control before
226380aa1dffSFenghua Yu	  you enable this feature.
226480aa1dffSFenghua Yu
226580aa1dffSFenghua Yu	  Say N if you don't want to enable CPU0 hotplug feature by default.
226680aa1dffSFenghua Yu	  You still can enable the CPU0 hotplug feature at boot by kernel
226780aa1dffSFenghua Yu	  parameter cpu0_hotplug.
226880aa1dffSFenghua Yu
2269a71c8bc5SFenghua Yuconfig DEBUG_HOTPLUG_CPU0
2270a71c8bc5SFenghua Yu	def_bool n
2271a71c8bc5SFenghua Yu	prompt "Debug CPU0 hotplug"
22722c922cd0SKees Cook	depends on HOTPLUG_CPU
2273a71c8bc5SFenghua Yu	---help---
2274a71c8bc5SFenghua Yu	  Enabling this option offlines CPU0 (if CPU0 can be offlined) as
2275a71c8bc5SFenghua Yu	  soon as possible and boots up userspace with CPU0 offlined. User
2276a71c8bc5SFenghua Yu	  can online CPU0 back after boot time.
2277a71c8bc5SFenghua Yu
2278a71c8bc5SFenghua Yu	  To debug CPU0 hotplug, you need to enable CPU0 offline/online
2279a71c8bc5SFenghua Yu	  feature by either turning on CONFIG_BOOTPARAM_HOTPLUG_CPU0 during
2280a71c8bc5SFenghua Yu	  compilation or giving cpu0_hotplug kernel parameter at boot.
2281a71c8bc5SFenghua Yu
2282a71c8bc5SFenghua Yu	  If unsure, say N.
2283a71c8bc5SFenghua Yu
2284506f1d07SSam Ravnborgconfig COMPAT_VDSO
2285b0b49f26SAndy Lutomirski	def_bool n
2286b0b49f26SAndy Lutomirski	prompt "Disable the 32-bit vDSO (needed for glibc 2.3.3)"
2287953fee1dSIngo Molnar	depends on COMPAT_32
22888f9ca475SIngo Molnar	---help---
2289b0b49f26SAndy Lutomirski	  Certain buggy versions of glibc will crash if they are
2290b0b49f26SAndy Lutomirski	  presented with a 32-bit vDSO that is not mapped at the address
2291b0b49f26SAndy Lutomirski	  indicated in its segment table.
2292e84446deSRandy Dunlap
2293b0b49f26SAndy Lutomirski	  The bug was introduced by f866314b89d56845f55e6f365e18b31ec978ec3a
2294b0b49f26SAndy Lutomirski	  and fixed by 3b3ddb4f7db98ec9e912ccdf54d35df4aa30e04a and
2295b0b49f26SAndy Lutomirski	  49ad572a70b8aeb91e57483a11dd1b77e31c4468.  Glibc 2.3.3 is
2296b0b49f26SAndy Lutomirski	  the only released version with the bug, but OpenSUSE 9
2297b0b49f26SAndy Lutomirski	  contains a buggy "glibc 2.3.2".
2298506f1d07SSam Ravnborg
2299b0b49f26SAndy Lutomirski	  The symptom of the bug is that everything crashes on startup, saying:
2300b0b49f26SAndy Lutomirski	  dl_main: Assertion `(void *) ph->p_vaddr == _rtld_local._dl_sysinfo_dso' failed!
2301b0b49f26SAndy Lutomirski
2302b0b49f26SAndy Lutomirski	  Saying Y here changes the default value of the vdso32 boot
2303b0b49f26SAndy Lutomirski	  option from 1 to 0, which turns off the 32-bit vDSO entirely.
2304b0b49f26SAndy Lutomirski	  This works around the glibc bug but hurts performance.
2305b0b49f26SAndy Lutomirski
2306b0b49f26SAndy Lutomirski	  If unsure, say N: if you are compiling your own kernel, you
2307b0b49f26SAndy Lutomirski	  are unlikely to be using a buggy version of glibc.
2308506f1d07SSam Ravnborg
23093dc33bd3SKees Cookchoice
23103dc33bd3SKees Cook	prompt "vsyscall table for legacy applications"
23113dc33bd3SKees Cook	depends on X86_64
23123dc33bd3SKees Cook	default LEGACY_VSYSCALL_EMULATE
23133dc33bd3SKees Cook	help
23143dc33bd3SKees Cook	  Legacy user code that does not know how to find the vDSO expects
23153dc33bd3SKees Cook	  to be able to issue three syscalls by calling fixed addresses in
23163dc33bd3SKees Cook	  kernel space. Since this location is not randomized with ASLR,
23173dc33bd3SKees Cook	  it can be used to assist security vulnerability exploitation.
23183dc33bd3SKees Cook
23193dc33bd3SKees Cook	  This setting can be changed at boot time via the kernel command
2320076ca272SAndy Lutomirski	  line parameter vsyscall=[emulate|none].
23213dc33bd3SKees Cook
23223dc33bd3SKees Cook	  On a system with recent enough glibc (2.14 or newer) and no
23233dc33bd3SKees Cook	  static binaries, you can say None without a performance penalty
23243dc33bd3SKees Cook	  to improve security.
23253dc33bd3SKees Cook
23263dc33bd3SKees Cook	  If unsure, select "Emulate".
23273dc33bd3SKees Cook
23283dc33bd3SKees Cook	config LEGACY_VSYSCALL_EMULATE
23293dc33bd3SKees Cook		bool "Emulate"
23303dc33bd3SKees Cook		help
23313dc33bd3SKees Cook		  The kernel traps and emulates calls into the fixed
23323dc33bd3SKees Cook		  vsyscall address mapping. This makes the mapping
23333dc33bd3SKees Cook		  non-executable, but it still contains known contents,
23343dc33bd3SKees Cook		  which could be used in certain rare security vulnerability
23353dc33bd3SKees Cook		  exploits. This configuration is recommended when userspace
23363dc33bd3SKees Cook		  still uses the vsyscall area.
23373dc33bd3SKees Cook
23383dc33bd3SKees Cook	config LEGACY_VSYSCALL_NONE
23393dc33bd3SKees Cook		bool "None"
23403dc33bd3SKees Cook		help
23413dc33bd3SKees Cook		  There will be no vsyscall mapping at all. This will
23423dc33bd3SKees Cook		  eliminate any risk of ASLR bypass due to the vsyscall
23433dc33bd3SKees Cook		  fixed address mapping. Attempts to use the vsyscalls
23443dc33bd3SKees Cook		  will be reported to dmesg, so that either old or
23453dc33bd3SKees Cook		  malicious userspace programs can be identified.
23463dc33bd3SKees Cook
23473dc33bd3SKees Cookendchoice
23483dc33bd3SKees Cook
2349516cbf37STim Birdconfig CMDLINE_BOOL
2350516cbf37STim Bird	bool "Built-in kernel command line"
23518f9ca475SIngo Molnar	---help---
2352516cbf37STim Bird	  Allow for specifying boot arguments to the kernel at
2353516cbf37STim Bird	  build time.  On some systems (e.g. embedded ones), it is
2354516cbf37STim Bird	  necessary or convenient to provide some or all of the
2355516cbf37STim Bird	  kernel boot arguments with the kernel itself (that is,
2356516cbf37STim Bird	  to not rely on the boot loader to provide them.)
2357516cbf37STim Bird
2358516cbf37STim Bird	  To compile command line arguments into the kernel,
2359516cbf37STim Bird	  set this option to 'Y', then fill in the
236069711ca1SSébastien Hinderer	  boot arguments in CONFIG_CMDLINE.
2361516cbf37STim Bird
2362516cbf37STim Bird	  Systems with fully functional boot loaders (i.e. non-embedded)
2363516cbf37STim Bird	  should leave this option set to 'N'.
2364516cbf37STim Bird
2365516cbf37STim Birdconfig CMDLINE
2366516cbf37STim Bird	string "Built-in kernel command string"
2367516cbf37STim Bird	depends on CMDLINE_BOOL
2368516cbf37STim Bird	default ""
23698f9ca475SIngo Molnar	---help---
2370516cbf37STim Bird	  Enter arguments here that should be compiled into the kernel
2371516cbf37STim Bird	  image and used at boot time.  If the boot loader provides a
2372516cbf37STim Bird	  command line at boot time, it is appended to this string to
2373516cbf37STim Bird	  form the full kernel command line, when the system boots.
2374516cbf37STim Bird
2375516cbf37STim Bird	  However, you can use the CONFIG_CMDLINE_OVERRIDE option to
2376516cbf37STim Bird	  change this behavior.
2377516cbf37STim Bird
2378516cbf37STim Bird	  In most cases, the command line (whether built-in or provided
2379516cbf37STim Bird	  by the boot loader) should specify the device for the root
2380516cbf37STim Bird	  file system.
2381516cbf37STim Bird
2382516cbf37STim Birdconfig CMDLINE_OVERRIDE
2383516cbf37STim Bird	bool "Built-in command line overrides boot loader arguments"
2384516cbf37STim Bird	depends on CMDLINE_BOOL
23858f9ca475SIngo Molnar	---help---
2386516cbf37STim Bird	  Set this option to 'Y' to have the kernel ignore the boot loader
2387516cbf37STim Bird	  command line, and use ONLY the built-in command line.
2388516cbf37STim Bird
2389516cbf37STim Bird	  This is used to work around broken boot loaders.  This should
2390516cbf37STim Bird	  be set to 'N' under normal conditions.
2391516cbf37STim Bird
2392a5b9e5a2SAndy Lutomirskiconfig MODIFY_LDT_SYSCALL
2393a5b9e5a2SAndy Lutomirski	bool "Enable the LDT (local descriptor table)" if EXPERT
2394a5b9e5a2SAndy Lutomirski	default y
2395a5b9e5a2SAndy Lutomirski	---help---
2396a5b9e5a2SAndy Lutomirski	  Linux can allow user programs to install a per-process x86
2397a5b9e5a2SAndy Lutomirski	  Local Descriptor Table (LDT) using the modify_ldt(2) system
2398a5b9e5a2SAndy Lutomirski	  call.  This is required to run 16-bit or segmented code such as
2399a5b9e5a2SAndy Lutomirski	  DOSEMU or some Wine programs.  It is also used by some very old
2400a5b9e5a2SAndy Lutomirski	  threading libraries.
2401a5b9e5a2SAndy Lutomirski
2402a5b9e5a2SAndy Lutomirski	  Enabling this feature adds a small amount of overhead to
2403a5b9e5a2SAndy Lutomirski	  context switches and increases the low-level kernel attack
2404a5b9e5a2SAndy Lutomirski	  surface.  Disabling it removes the modify_ldt(2) system call.
2405a5b9e5a2SAndy Lutomirski
2406a5b9e5a2SAndy Lutomirski	  Saying 'N' here may make sense for embedded or server kernels.
2407a5b9e5a2SAndy Lutomirski
2408b700e7f0SSeth Jenningssource "kernel/livepatch/Kconfig"
2409b700e7f0SSeth Jennings
2410506f1d07SSam Ravnborgendmenu
2411506f1d07SSam Ravnborg
24123072e413SMichal Hockoconfig ARCH_HAS_ADD_PAGES
24133072e413SMichal Hocko	def_bool y
24143072e413SMichal Hocko	depends on X86_64 && ARCH_ENABLE_MEMORY_HOTPLUG
24153072e413SMichal Hocko
2416506f1d07SSam Ravnborgconfig ARCH_ENABLE_MEMORY_HOTPLUG
2417506f1d07SSam Ravnborg	def_bool y
2418506f1d07SSam Ravnborg	depends on X86_64 || (X86_32 && HIGHMEM)
2419506f1d07SSam Ravnborg
242035551053SGary Hadeconfig ARCH_ENABLE_MEMORY_HOTREMOVE
242135551053SGary Hade	def_bool y
242235551053SGary Hade	depends on MEMORY_HOTPLUG
242335551053SGary Hade
2424e534c7c5SLee Schermerhornconfig USE_PERCPU_NUMA_NODE_ID
2425645a7919STejun Heo	def_bool y
2426e534c7c5SLee Schermerhorn	depends on NUMA
2427e534c7c5SLee Schermerhorn
24289491846fSKirill A. Shutemovconfig ARCH_ENABLE_SPLIT_PMD_PTLOCK
24299491846fSKirill A. Shutemov	def_bool y
24309491846fSKirill A. Shutemov	depends on X86_64 || X86_PAE
24319491846fSKirill A. Shutemov
2432c177c81eSNaoya Horiguchiconfig ARCH_ENABLE_HUGEPAGE_MIGRATION
2433c177c81eSNaoya Horiguchi	def_bool y
2434c177c81eSNaoya Horiguchi	depends on X86_64 && HUGETLB_PAGE && MIGRATION
2435c177c81eSNaoya Horiguchi
24369c670ea3SNaoya Horiguchiconfig ARCH_ENABLE_THP_MIGRATION
24379c670ea3SNaoya Horiguchi	def_bool y
24389c670ea3SNaoya Horiguchi	depends on X86_64 && TRANSPARENT_HUGEPAGE
24399c670ea3SNaoya Horiguchi
2440da85f865SBjorn Helgaasmenu "Power management and ACPI options"
2441e279b6c1SSam Ravnborg
2442e279b6c1SSam Ravnborgconfig ARCH_HIBERNATION_HEADER
24433c2362e6SHarvey Harrison	def_bool y
2444e279b6c1SSam Ravnborg	depends on X86_64 && HIBERNATION
2445e279b6c1SSam Ravnborg
2446e279b6c1SSam Ravnborgsource "kernel/power/Kconfig"
2447e279b6c1SSam Ravnborg
2448e279b6c1SSam Ravnborgsource "drivers/acpi/Kconfig"
2449e279b6c1SSam Ravnborg
2450efafc8b2SFeng Tangsource "drivers/sfi/Kconfig"
2451efafc8b2SFeng Tang
2452a6b68076SAndi Kleenconfig X86_APM_BOOT
24536fc108a0SJan Beulich	def_bool y
2454282e5aabSPaul Bolle	depends on APM
2455a6b68076SAndi Kleen
2456e279b6c1SSam Ravnborgmenuconfig APM
2457e279b6c1SSam Ravnborg	tristate "APM (Advanced Power Management) BIOS support"
2458efefa6f6SIngo Molnar	depends on X86_32 && PM_SLEEP
2459e279b6c1SSam Ravnborg	---help---
2460e279b6c1SSam Ravnborg	  APM is a BIOS specification for saving power using several different
2461e279b6c1SSam Ravnborg	  techniques. This is mostly useful for battery powered laptops with
2462e279b6c1SSam Ravnborg	  APM compliant BIOSes. If you say Y here, the system time will be
2463e279b6c1SSam Ravnborg	  reset after a RESUME operation, the /proc/apm device will provide
2464e279b6c1SSam Ravnborg	  battery status information, and user-space programs will receive
2465e279b6c1SSam Ravnborg	  notification of APM "events" (e.g. battery status change).
2466e279b6c1SSam Ravnborg
2467e279b6c1SSam Ravnborg	  If you select "Y" here, you can disable actual use of the APM
2468e279b6c1SSam Ravnborg	  BIOS by passing the "apm=off" option to the kernel at boot time.
2469e279b6c1SSam Ravnborg
2470e279b6c1SSam Ravnborg	  Note that the APM support is almost completely disabled for
2471e279b6c1SSam Ravnborg	  machines with more than one CPU.
2472e279b6c1SSam Ravnborg
2473e279b6c1SSam Ravnborg	  In order to use APM, you will need supporting software. For location
24742dc98fd3SMichael Witten	  and more information, read <file:Documentation/power/apm-acpi.txt>
24752dc98fd3SMichael Witten	  and the Battery Powered Linux mini-HOWTO, available from
2476e279b6c1SSam Ravnborg	  <http://www.tldp.org/docs.html#howto>.
2477e279b6c1SSam Ravnborg
2478e279b6c1SSam Ravnborg	  This driver does not spin down disk drives (see the hdparm(8)
2479e279b6c1SSam Ravnborg	  manpage ("man 8 hdparm") for that), and it doesn't turn off
2480e279b6c1SSam Ravnborg	  VESA-compliant "green" monitors.
2481e279b6c1SSam Ravnborg
2482e279b6c1SSam Ravnborg	  This driver does not support the TI 4000M TravelMate and the ACER
2483e279b6c1SSam Ravnborg	  486/DX4/75 because they don't have compliant BIOSes. Many "green"
2484e279b6c1SSam Ravnborg	  desktop machines also don't have compliant BIOSes, and this driver
2485e279b6c1SSam Ravnborg	  may cause those machines to panic during the boot phase.
2486e279b6c1SSam Ravnborg
2487e279b6c1SSam Ravnborg	  Generally, if you don't have a battery in your machine, there isn't
2488e279b6c1SSam Ravnborg	  much point in using this driver and you should say N. If you get
2489e279b6c1SSam Ravnborg	  random kernel OOPSes or reboots that don't seem to be related to
2490e279b6c1SSam Ravnborg	  anything, try disabling/enabling this option (or disabling/enabling
2491e279b6c1SSam Ravnborg	  APM in your BIOS).
2492e279b6c1SSam Ravnborg
2493e279b6c1SSam Ravnborg	  Some other things you should try when experiencing seemingly random,
2494e279b6c1SSam Ravnborg	  "weird" problems:
2495e279b6c1SSam Ravnborg
2496e279b6c1SSam Ravnborg	  1) make sure that you have enough swap space and that it is
2497e279b6c1SSam Ravnborg	  enabled.
2498e279b6c1SSam Ravnborg	  2) pass the "no-hlt" option to the kernel
2499e279b6c1SSam Ravnborg	  3) switch on floating point emulation in the kernel and pass
2500e279b6c1SSam Ravnborg	  the "no387" option to the kernel
2501e279b6c1SSam Ravnborg	  4) pass the "floppy=nodma" option to the kernel
2502e279b6c1SSam Ravnborg	  5) pass the "mem=4M" option to the kernel (thereby disabling
2503e279b6c1SSam Ravnborg	  all but the first 4 MB of RAM)
2504e279b6c1SSam Ravnborg	  6) make sure that the CPU is not over clocked.
2505e279b6c1SSam Ravnborg	  7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/>
2506e279b6c1SSam Ravnborg	  8) disable the cache from your BIOS settings
2507e279b6c1SSam Ravnborg	  9) install a fan for the video card or exchange video RAM
2508e279b6c1SSam Ravnborg	  10) install a better fan for the CPU
2509e279b6c1SSam Ravnborg	  11) exchange RAM chips
2510e279b6c1SSam Ravnborg	  12) exchange the motherboard.
2511e279b6c1SSam Ravnborg
2512e279b6c1SSam Ravnborg	  To compile this driver as a module, choose M here: the
2513e279b6c1SSam Ravnborg	  module will be called apm.
2514e279b6c1SSam Ravnborg
2515e279b6c1SSam Ravnborgif APM
2516e279b6c1SSam Ravnborg
2517e279b6c1SSam Ravnborgconfig APM_IGNORE_USER_SUSPEND
2518e279b6c1SSam Ravnborg	bool "Ignore USER SUSPEND"
25198f9ca475SIngo Molnar	---help---
2520e279b6c1SSam Ravnborg	  This option will ignore USER SUSPEND requests. On machines with a
2521e279b6c1SSam Ravnborg	  compliant APM BIOS, you want to say N. However, on the NEC Versa M
2522e279b6c1SSam Ravnborg	  series notebooks, it is necessary to say Y because of a BIOS bug.
2523e279b6c1SSam Ravnborg
2524e279b6c1SSam Ravnborgconfig APM_DO_ENABLE
2525e279b6c1SSam Ravnborg	bool "Enable PM at boot time"
2526e279b6c1SSam Ravnborg	---help---
2527e279b6c1SSam Ravnborg	  Enable APM features at boot time. From page 36 of the APM BIOS
2528e279b6c1SSam Ravnborg	  specification: "When disabled, the APM BIOS does not automatically
2529e279b6c1SSam Ravnborg	  power manage devices, enter the Standby State, enter the Suspend
2530e279b6c1SSam Ravnborg	  State, or take power saving steps in response to CPU Idle calls."
2531e279b6c1SSam Ravnborg	  This driver will make CPU Idle calls when Linux is idle (unless this
2532e279b6c1SSam Ravnborg	  feature is turned off -- see "Do CPU IDLE calls", below). This
2533e279b6c1SSam Ravnborg	  should always save battery power, but more complicated APM features
2534e279b6c1SSam Ravnborg	  will be dependent on your BIOS implementation. You may need to turn
2535e279b6c1SSam Ravnborg	  this option off if your computer hangs at boot time when using APM
2536e279b6c1SSam Ravnborg	  support, or if it beeps continuously instead of suspending. Turn
2537e279b6c1SSam Ravnborg	  this off if you have a NEC UltraLite Versa 33/C or a Toshiba
2538e279b6c1SSam Ravnborg	  T400CDT. This is off by default since most machines do fine without
2539e279b6c1SSam Ravnborg	  this feature.
2540e279b6c1SSam Ravnborg
2541e279b6c1SSam Ravnborgconfig APM_CPU_IDLE
2542dd8af076SLen Brown	depends on CPU_IDLE
2543e279b6c1SSam Ravnborg	bool "Make CPU Idle calls when idle"
25448f9ca475SIngo Molnar	---help---
2545e279b6c1SSam Ravnborg	  Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop.
2546e279b6c1SSam Ravnborg	  On some machines, this can activate improved power savings, such as
2547e279b6c1SSam Ravnborg	  a slowed CPU clock rate, when the machine is idle. These idle calls
2548e279b6c1SSam Ravnborg	  are made after the idle loop has run for some length of time (e.g.,
2549e279b6c1SSam Ravnborg	  333 mS). On some machines, this will cause a hang at boot time or
2550e279b6c1SSam Ravnborg	  whenever the CPU becomes idle. (On machines with more than one CPU,
2551e279b6c1SSam Ravnborg	  this option does nothing.)
2552e279b6c1SSam Ravnborg
2553e279b6c1SSam Ravnborgconfig APM_DISPLAY_BLANK
2554e279b6c1SSam Ravnborg	bool "Enable console blanking using APM"
25558f9ca475SIngo Molnar	---help---
2556e279b6c1SSam Ravnborg	  Enable console blanking using the APM. Some laptops can use this to
2557e279b6c1SSam Ravnborg	  turn off the LCD backlight when the screen blanker of the Linux
2558e279b6c1SSam Ravnborg	  virtual console blanks the screen. Note that this is only used by
2559e279b6c1SSam Ravnborg	  the virtual console screen blanker, and won't turn off the backlight
2560e279b6c1SSam Ravnborg	  when using the X Window system. This also doesn't have anything to
2561e279b6c1SSam Ravnborg	  do with your VESA-compliant power-saving monitor. Further, this
2562e279b6c1SSam Ravnborg	  option doesn't work for all laptops -- it might not turn off your
2563e279b6c1SSam Ravnborg	  backlight at all, or it might print a lot of errors to the console,
2564e279b6c1SSam Ravnborg	  especially if you are using gpm.
2565e279b6c1SSam Ravnborg
2566e279b6c1SSam Ravnborgconfig APM_ALLOW_INTS
2567e279b6c1SSam Ravnborg	bool "Allow interrupts during APM BIOS calls"
25688f9ca475SIngo Molnar	---help---
2569e279b6c1SSam Ravnborg	  Normally we disable external interrupts while we are making calls to
2570e279b6c1SSam Ravnborg	  the APM BIOS as a measure to lessen the effects of a badly behaving
2571e279b6c1SSam Ravnborg	  BIOS implementation.  The BIOS should reenable interrupts if it
2572e279b6c1SSam Ravnborg	  needs to.  Unfortunately, some BIOSes do not -- especially those in
2573e279b6c1SSam Ravnborg	  many of the newer IBM Thinkpads.  If you experience hangs when you
2574e279b6c1SSam Ravnborg	  suspend, try setting this to Y.  Otherwise, say N.
2575e279b6c1SSam Ravnborg
2576e279b6c1SSam Ravnborgendif # APM
2577e279b6c1SSam Ravnborg
2578bb0a56ecSDave Jonessource "drivers/cpufreq/Kconfig"
2579e279b6c1SSam Ravnborg
2580e279b6c1SSam Ravnborgsource "drivers/cpuidle/Kconfig"
2581e279b6c1SSam Ravnborg
258227471fdbSAndy Henroidsource "drivers/idle/Kconfig"
258327471fdbSAndy Henroid
2584e279b6c1SSam Ravnborgendmenu
2585e279b6c1SSam Ravnborg
2586e279b6c1SSam Ravnborg
2587e279b6c1SSam Ravnborgmenu "Bus options (PCI etc.)"
2588e279b6c1SSam Ravnborg
2589e279b6c1SSam Ravnborgconfig PCI
25901ac97018SIngo Molnar	bool "PCI support"
25911c858087SAdrian Bunk	default y
25928f9ca475SIngo Molnar	---help---
2593e279b6c1SSam Ravnborg	  Find out whether you have a PCI motherboard. PCI is the name of a
2594e279b6c1SSam Ravnborg	  bus system, i.e. the way the CPU talks to the other stuff inside
2595e279b6c1SSam Ravnborg	  your box. Other bus systems are ISA, EISA, MicroChannel (MCA) or
2596e279b6c1SSam Ravnborg	  VESA. If you have PCI, say Y, otherwise N.
2597e279b6c1SSam Ravnborg
2598e279b6c1SSam Ravnborgchoice
2599e279b6c1SSam Ravnborg	prompt "PCI access mode"
2600efefa6f6SIngo Molnar	depends on X86_32 && PCI
2601e279b6c1SSam Ravnborg	default PCI_GOANY
2602e279b6c1SSam Ravnborg	---help---
2603e279b6c1SSam Ravnborg	  On PCI systems, the BIOS can be used to detect the PCI devices and
2604e279b6c1SSam Ravnborg	  determine their configuration. However, some old PCI motherboards
2605e279b6c1SSam Ravnborg	  have BIOS bugs and may crash if this is done. Also, some embedded
2606e279b6c1SSam Ravnborg	  PCI-based systems don't have any BIOS at all. Linux can also try to
2607e279b6c1SSam Ravnborg	  detect the PCI hardware directly without using the BIOS.
2608e279b6c1SSam Ravnborg
2609e279b6c1SSam Ravnborg	  With this option, you can specify how Linux should detect the
2610e279b6c1SSam Ravnborg	  PCI devices. If you choose "BIOS", the BIOS will be used,
2611e279b6c1SSam Ravnborg	  if you choose "Direct", the BIOS won't be used, and if you
2612e279b6c1SSam Ravnborg	  choose "MMConfig", then PCI Express MMCONFIG will be used.
2613e279b6c1SSam Ravnborg	  If you choose "Any", the kernel will try MMCONFIG, then the
2614e279b6c1SSam Ravnborg	  direct access method and falls back to the BIOS if that doesn't
2615e279b6c1SSam Ravnborg	  work. If unsure, go with the default, which is "Any".
2616e279b6c1SSam Ravnborg
2617e279b6c1SSam Ravnborgconfig PCI_GOBIOS
2618e279b6c1SSam Ravnborg	bool "BIOS"
2619e279b6c1SSam Ravnborg
2620e279b6c1SSam Ravnborgconfig PCI_GOMMCONFIG
2621e279b6c1SSam Ravnborg	bool "MMConfig"
2622e279b6c1SSam Ravnborg
2623e279b6c1SSam Ravnborgconfig PCI_GODIRECT
2624e279b6c1SSam Ravnborg	bool "Direct"
2625e279b6c1SSam Ravnborg
26263ef0e1f8SAndres Salomonconfig PCI_GOOLPC
262776fb6570SDaniel Drake	bool "OLPC XO-1"
26283ef0e1f8SAndres Salomon	depends on OLPC
26293ef0e1f8SAndres Salomon
26302bdd1b03SAndres Salomonconfig PCI_GOANY
26312bdd1b03SAndres Salomon	bool "Any"
26322bdd1b03SAndres Salomon
2633e279b6c1SSam Ravnborgendchoice
2634e279b6c1SSam Ravnborg
2635e279b6c1SSam Ravnborgconfig PCI_BIOS
26363c2362e6SHarvey Harrison	def_bool y
2637efefa6f6SIngo Molnar	depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY)
2638e279b6c1SSam Ravnborg
2639e279b6c1SSam Ravnborg# x86-64 doesn't support PCI BIOS access from long mode so always go direct.
2640e279b6c1SSam Ravnborgconfig PCI_DIRECT
26413c2362e6SHarvey Harrison	def_bool y
26420aba496fSShaohua Li	depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC || PCI_GOMMCONFIG))
2643e279b6c1SSam Ravnborg
2644e279b6c1SSam Ravnborgconfig PCI_MMCONFIG
26453c2362e6SHarvey Harrison	def_bool y
26465f0db7a2SFeng Tang	depends on X86_32 && PCI && (ACPI || SFI) && (PCI_GOMMCONFIG || PCI_GOANY)
2647e279b6c1SSam Ravnborg
26483ef0e1f8SAndres Salomonconfig PCI_OLPC
26492bdd1b03SAndres Salomon	def_bool y
26502bdd1b03SAndres Salomon	depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY)
26513ef0e1f8SAndres Salomon
2652b5401a96SAlex Nixonconfig PCI_XEN
2653b5401a96SAlex Nixon	def_bool y
2654b5401a96SAlex Nixon	depends on PCI && XEN
2655b5401a96SAlex Nixon	select SWIOTLB_XEN
2656b5401a96SAlex Nixon
2657e279b6c1SSam Ravnborgconfig PCI_DOMAINS
26583c2362e6SHarvey Harrison	def_bool y
2659e279b6c1SSam Ravnborg	depends on PCI
2660e279b6c1SSam Ravnborg
2661e279b6c1SSam Ravnborgconfig PCI_MMCONFIG
2662e279b6c1SSam Ravnborg	bool "Support mmconfig PCI config space access"
2663e279b6c1SSam Ravnborg	depends on X86_64 && PCI && ACPI
2664e279b6c1SSam Ravnborg
26653f6ea84aSIra W. Snyderconfig PCI_CNB20LE_QUIRK
26666a108a14SDavid Rientjes	bool "Read CNB20LE Host Bridge Windows" if EXPERT
26676ea30386SKees Cook	depends on PCI
26683f6ea84aSIra W. Snyder	help
26693f6ea84aSIra W. Snyder	  Read the PCI windows out of the CNB20LE host bridge. This allows
26703f6ea84aSIra W. Snyder	  PCI hotplug to work on systems with the CNB20LE chipset which do
26713f6ea84aSIra W. Snyder	  not have ACPI.
26723f6ea84aSIra W. Snyder
267364a5fed6SBjorn Helgaas	  There's no public spec for this chipset, and this functionality
267464a5fed6SBjorn Helgaas	  is known to be incomplete.
267564a5fed6SBjorn Helgaas
267664a5fed6SBjorn Helgaas	  You should say N unless you know you need this.
267764a5fed6SBjorn Helgaas
2678e279b6c1SSam Ravnborgsource "drivers/pci/Kconfig"
2679e279b6c1SSam Ravnborg
26803a495511SWilliam Breathitt Grayconfig ISA_BUS
26813a495511SWilliam Breathitt Gray	bool "ISA-style bus support on modern systems" if EXPERT
26823a495511SWilliam Breathitt Gray	select ISA_BUS_API
26833a495511SWilliam Breathitt Gray	help
26843a495511SWilliam Breathitt Gray	  Enables ISA-style drivers on modern systems. This is necessary to
26853a495511SWilliam Breathitt Gray	  support PC/104 devices on X86_64 platforms.
26863a495511SWilliam Breathitt Gray
26873a495511SWilliam Breathitt Gray	  If unsure, say N.
26883a495511SWilliam Breathitt Gray
26891c00f016SDavid Rientjes# x86_64 have no ISA slots, but can have ISA-style DMA.
2690e279b6c1SSam Ravnborgconfig ISA_DMA_API
26911c00f016SDavid Rientjes	bool "ISA-style DMA support" if (X86_64 && EXPERT)
26921c00f016SDavid Rientjes	default y
26931c00f016SDavid Rientjes	help
26941c00f016SDavid Rientjes	  Enables ISA-style DMA support for devices requiring such controllers.
26951c00f016SDavid Rientjes	  If unsure, say Y.
2696e279b6c1SSam Ravnborg
269751e68d05SLinus Torvaldsif X86_32
269851e68d05SLinus Torvalds
2699e279b6c1SSam Ravnborgconfig ISA
2700e279b6c1SSam Ravnborg	bool "ISA support"
27018f9ca475SIngo Molnar	---help---
2702e279b6c1SSam Ravnborg	  Find out whether you have ISA slots on your motherboard.  ISA is the
2703e279b6c1SSam Ravnborg	  name of a bus system, i.e. the way the CPU talks to the other stuff
2704e279b6c1SSam Ravnborg	  inside your box.  Other bus systems are PCI, EISA, MicroChannel
2705e279b6c1SSam Ravnborg	  (MCA) or VESA.  ISA is an older system, now being displaced by PCI;
2706e279b6c1SSam Ravnborg	  newer boards don't support it.  If you have ISA, say Y, otherwise N.
2707e279b6c1SSam Ravnborg
2708e279b6c1SSam Ravnborgconfig EISA
2709e279b6c1SSam Ravnborg	bool "EISA support"
2710e279b6c1SSam Ravnborg	depends on ISA
2711e279b6c1SSam Ravnborg	---help---
2712e279b6c1SSam Ravnborg	  The Extended Industry Standard Architecture (EISA) bus was
2713e279b6c1SSam Ravnborg	  developed as an open alternative to the IBM MicroChannel bus.
2714e279b6c1SSam Ravnborg
2715e279b6c1SSam Ravnborg	  The EISA bus provided some of the features of the IBM MicroChannel
2716e279b6c1SSam Ravnborg	  bus while maintaining backward compatibility with cards made for
2717e279b6c1SSam Ravnborg	  the older ISA bus.  The EISA bus saw limited use between 1988 and
2718e279b6c1SSam Ravnborg	  1995 when it was made obsolete by the PCI bus.
2719e279b6c1SSam Ravnborg
2720e279b6c1SSam Ravnborg	  Say Y here if you are building a kernel for an EISA-based machine.
2721e279b6c1SSam Ravnborg
2722e279b6c1SSam Ravnborg	  Otherwise, say N.
2723e279b6c1SSam Ravnborg
2724e279b6c1SSam Ravnborgsource "drivers/eisa/Kconfig"
2725e279b6c1SSam Ravnborg
2726e279b6c1SSam Ravnborgconfig SCx200
2727e279b6c1SSam Ravnborg	tristate "NatSemi SCx200 support"
27288f9ca475SIngo Molnar	---help---
2729e279b6c1SSam Ravnborg	  This provides basic support for National Semiconductor's
2730e279b6c1SSam Ravnborg	  (now AMD's) Geode processors.  The driver probes for the
2731e279b6c1SSam Ravnborg	  PCI-IDs of several on-chip devices, so its a good dependency
2732e279b6c1SSam Ravnborg	  for other scx200_* drivers.
2733e279b6c1SSam Ravnborg
2734e279b6c1SSam Ravnborg	  If compiled as a module, the driver is named scx200.
2735e279b6c1SSam Ravnborg
2736e279b6c1SSam Ravnborgconfig SCx200HR_TIMER
2737e279b6c1SSam Ravnborg	tristate "NatSemi SCx200 27MHz High-Resolution Timer Support"
2738592913ecSJohn Stultz	depends on SCx200
2739e279b6c1SSam Ravnborg	default y
27408f9ca475SIngo Molnar	---help---
2741e279b6c1SSam Ravnborg	  This driver provides a clocksource built upon the on-chip
2742e279b6c1SSam Ravnborg	  27MHz high-resolution timer.  Its also a workaround for
2743e279b6c1SSam Ravnborg	  NSC Geode SC-1100's buggy TSC, which loses time when the
2744e279b6c1SSam Ravnborg	  processor goes idle (as is done by the scheduler).  The
2745e279b6c1SSam Ravnborg	  other workaround is idle=poll boot option.
2746e279b6c1SSam Ravnborg
27473ef0e1f8SAndres Salomonconfig OLPC
27483ef0e1f8SAndres Salomon	bool "One Laptop Per Child support"
274954008979SThomas Gleixner	depends on !X86_PAE
27503c554946SAndres Salomon	select GPIOLIB
2751dc3119e7SThomas Gleixner	select OF
275245bb1674SDaniel Drake	select OF_PROMTREE
2753b4e51854SGrant Likely	select IRQ_DOMAIN
27548f9ca475SIngo Molnar	---help---
27553ef0e1f8SAndres Salomon	  Add support for detecting the unique features of the OLPC
27563ef0e1f8SAndres Salomon	  XO hardware.
27573ef0e1f8SAndres Salomon
2758a3128588SDaniel Drakeconfig OLPC_XO1_PM
2759a3128588SDaniel Drake	bool "OLPC XO-1 Power Management"
276097c4cb71SDaniel Drake	depends on OLPC && MFD_CS5535 && PM_SLEEP
2761a3128588SDaniel Drake	select MFD_CORE
2762bf1ebf00SDaniel Drake	---help---
276397c4cb71SDaniel Drake	  Add support for poweroff and suspend of the OLPC XO-1 laptop.
2764bf1ebf00SDaniel Drake
2765cfee9597SDaniel Drakeconfig OLPC_XO1_RTC
2766cfee9597SDaniel Drake	bool "OLPC XO-1 Real Time Clock"
2767cfee9597SDaniel Drake	depends on OLPC_XO1_PM && RTC_DRV_CMOS
2768cfee9597SDaniel Drake	---help---
2769cfee9597SDaniel Drake	  Add support for the XO-1 real time clock, which can be used as a
2770cfee9597SDaniel Drake	  programmable wakeup source.
2771cfee9597SDaniel Drake
27727feda8e9SDaniel Drakeconfig OLPC_XO1_SCI
27737feda8e9SDaniel Drake	bool "OLPC XO-1 SCI extras"
2774d8d01a63SDaniel Drake	depends on OLPC && OLPC_XO1_PM
2775ed8e47feSRandy Dunlap	depends on INPUT=y
2776d8d01a63SDaniel Drake	select POWER_SUPPLY
27777feda8e9SDaniel Drake	select GPIO_CS5535
27787feda8e9SDaniel Drake	select MFD_CORE
27797feda8e9SDaniel Drake	---help---
27807feda8e9SDaniel Drake	  Add support for SCI-based features of the OLPC XO-1 laptop:
27817bc74b3dSDaniel Drake	   - EC-driven system wakeups
27827feda8e9SDaniel Drake	   - Power button
27837bc74b3dSDaniel Drake	   - Ebook switch
27842cf2baeaSDaniel Drake	   - Lid switch
2785e1040ac6SDaniel Drake	   - AC adapter status updates
2786e1040ac6SDaniel Drake	   - Battery status updates
27877feda8e9SDaniel Drake
2788a0f30f59SDaniel Drakeconfig OLPC_XO15_SCI
2789a0f30f59SDaniel Drake	bool "OLPC XO-1.5 SCI extras"
2790d8d01a63SDaniel Drake	depends on OLPC && ACPI
2791d8d01a63SDaniel Drake	select POWER_SUPPLY
2792a0f30f59SDaniel Drake	---help---
2793a0f30f59SDaniel Drake	  Add support for SCI-based features of the OLPC XO-1.5 laptop:
2794a0f30f59SDaniel Drake	   - EC-driven system wakeups
2795a0f30f59SDaniel Drake	   - AC adapter status updates
2796a0f30f59SDaniel Drake	   - Battery status updates
2797e279b6c1SSam Ravnborg
2798d4f3e350SEd Wildgooseconfig ALIX
2799d4f3e350SEd Wildgoose	bool "PCEngines ALIX System Support (LED setup)"
2800d4f3e350SEd Wildgoose	select GPIOLIB
2801d4f3e350SEd Wildgoose	---help---
2802d4f3e350SEd Wildgoose	  This option enables system support for the PCEngines ALIX.
2803d4f3e350SEd Wildgoose	  At present this just sets up LEDs for GPIO control on
2804d4f3e350SEd Wildgoose	  ALIX2/3/6 boards.  However, other system specific setup should
2805d4f3e350SEd Wildgoose	  get added here.
2806d4f3e350SEd Wildgoose
2807d4f3e350SEd Wildgoose	  Note: You must still enable the drivers for GPIO and LED support
2808d4f3e350SEd Wildgoose	  (GPIO_CS5535 & LEDS_GPIO) to actually use the LEDs
2809d4f3e350SEd Wildgoose
2810d4f3e350SEd Wildgoose	  Note: You have to set alix.force=1 for boards with Award BIOS.
2811d4f3e350SEd Wildgoose
2812da4e3302SPhilip Prindevilleconfig NET5501
2813da4e3302SPhilip Prindeville	bool "Soekris Engineering net5501 System Support (LEDS, GPIO, etc)"
2814da4e3302SPhilip Prindeville	select GPIOLIB
2815da4e3302SPhilip Prindeville	---help---
2816da4e3302SPhilip Prindeville	  This option enables system support for the Soekris Engineering net5501.
2817da4e3302SPhilip Prindeville
28183197059aSPhilip A. Prindevilleconfig GEOS
28193197059aSPhilip A. Prindeville	bool "Traverse Technologies GEOS System Support (LEDS, GPIO, etc)"
28203197059aSPhilip A. Prindeville	select GPIOLIB
28213197059aSPhilip A. Prindeville	depends on DMI
28223197059aSPhilip A. Prindeville	---help---
28233197059aSPhilip A. Prindeville	  This option enables system support for the Traverse Technologies GEOS.
28243197059aSPhilip A. Prindeville
28257d029125SVivien Didelotconfig TS5500
28267d029125SVivien Didelot	bool "Technologic Systems TS-5500 platform support"
28277d029125SVivien Didelot	depends on MELAN
28287d029125SVivien Didelot	select CHECK_SIGNATURE
28297d029125SVivien Didelot	select NEW_LEDS
28307d029125SVivien Didelot	select LEDS_CLASS
28317d029125SVivien Didelot	---help---
28327d029125SVivien Didelot	  This option enables system support for the Technologic Systems TS-5500.
28337d029125SVivien Didelot
2834e279b6c1SSam Ravnborgendif # X86_32
2835e279b6c1SSam Ravnborg
283623ac4ae8SAndreas Herrmannconfig AMD_NB
2837e279b6c1SSam Ravnborg	def_bool y
28380e152cd7SBorislav Petkov	depends on CPU_SUP_AMD && PCI
2839e279b6c1SSam Ravnborg
2840e279b6c1SSam Ravnborgsource "drivers/pcmcia/Kconfig"
2841e279b6c1SSam Ravnborg
2842388b78adSAlexandre Bounineconfig RAPIDIO
2843fdf90abcSAlexandre Bounine	tristate "RapidIO support"
2844388b78adSAlexandre Bounine	depends on PCI
2845388b78adSAlexandre Bounine	default n
2846388b78adSAlexandre Bounine	help
2847fdf90abcSAlexandre Bounine	  If enabled this option will include drivers and the core
2848388b78adSAlexandre Bounine	  infrastructure code to support RapidIO interconnect devices.
2849388b78adSAlexandre Bounine
2850388b78adSAlexandre Bouninesource "drivers/rapidio/Kconfig"
2851388b78adSAlexandre Bounine
2852e3263ab3SDavid Herrmannconfig X86_SYSFB
2853e3263ab3SDavid Herrmann	bool "Mark VGA/VBE/EFI FB as generic system framebuffer"
2854e3263ab3SDavid Herrmann	help
2855e3263ab3SDavid Herrmann	  Firmwares often provide initial graphics framebuffers so the BIOS,
2856e3263ab3SDavid Herrmann	  bootloader or kernel can show basic video-output during boot for
2857e3263ab3SDavid Herrmann	  user-guidance and debugging. Historically, x86 used the VESA BIOS
2858e3263ab3SDavid Herrmann	  Extensions and EFI-framebuffers for this, which are mostly limited
2859e3263ab3SDavid Herrmann	  to x86.
2860e3263ab3SDavid Herrmann	  This option, if enabled, marks VGA/VBE/EFI framebuffers as generic
2861e3263ab3SDavid Herrmann	  framebuffers so the new generic system-framebuffer drivers can be
2862e3263ab3SDavid Herrmann	  used on x86. If the framebuffer is not compatible with the generic
2863e3263ab3SDavid Herrmann	  modes, it is adverticed as fallback platform framebuffer so legacy
2864e3263ab3SDavid Herrmann	  drivers like efifb, vesafb and uvesafb can pick it up.
2865e3263ab3SDavid Herrmann	  If this option is not selected, all system framebuffers are always
2866e3263ab3SDavid Herrmann	  marked as fallback platform framebuffers as usual.
2867e3263ab3SDavid Herrmann
2868e3263ab3SDavid Herrmann	  Note: Legacy fbdev drivers, including vesafb, efifb, uvesafb, will
2869e3263ab3SDavid Herrmann	  not be able to pick up generic system framebuffers if this option
2870e3263ab3SDavid Herrmann	  is selected. You are highly encouraged to enable simplefb as
2871e3263ab3SDavid Herrmann	  replacement if you select this option. simplefb can correctly deal
2872e3263ab3SDavid Herrmann	  with generic system framebuffers. But you should still keep vesafb
2873e3263ab3SDavid Herrmann	  and others enabled as fallback if a system framebuffer is
2874e3263ab3SDavid Herrmann	  incompatible with simplefb.
2875e3263ab3SDavid Herrmann
2876e3263ab3SDavid Herrmann	  If unsure, say Y.
2877e3263ab3SDavid Herrmann
2878e279b6c1SSam Ravnborgendmenu
2879e279b6c1SSam Ravnborg
2880e279b6c1SSam Ravnborg
2881e279b6c1SSam Ravnborgmenu "Executable file formats / Emulations"
2882e279b6c1SSam Ravnborg
2883e279b6c1SSam Ravnborgsource "fs/Kconfig.binfmt"
2884e279b6c1SSam Ravnborg
2885e279b6c1SSam Ravnborgconfig IA32_EMULATION
2886e279b6c1SSam Ravnborg	bool "IA32 Emulation"
2887e279b6c1SSam Ravnborg	depends on X86_64
288839f88911SIngo Molnar	select ARCH_WANT_OLD_COMPAT_IPC
2889d1603990SRandy Dunlap	select BINFMT_ELF
2890a97f52e6SRoland McGrath	select COMPAT_BINFMT_ELF
289139f88911SIngo Molnar	select COMPAT_OLD_SIGACTION
28928f9ca475SIngo Molnar	---help---
28935fd92e65SH. J. Lu	  Include code to run legacy 32-bit programs under a
28945fd92e65SH. J. Lu	  64-bit kernel. You should likely turn this on, unless you're
28955fd92e65SH. J. Lu	  100% sure that you don't have any 32-bit programs left.
2896e279b6c1SSam Ravnborg
2897e279b6c1SSam Ravnborgconfig IA32_AOUT
2898e279b6c1SSam Ravnborg	tristate "IA32 a.out support"
28996b213e1bSDavid Woodhouse	depends on IA32_EMULATION
29008f9ca475SIngo Molnar	---help---
2901e279b6c1SSam Ravnborg	  Support old a.out binaries in the 32bit emulation.
2902e279b6c1SSam Ravnborg
29030bf62763SH. Peter Anvinconfig X86_X32
29046ea30386SKees Cook	bool "x32 ABI for 64-bit mode"
29059b54050bSBrian Gerst	depends on X86_64
29065fd92e65SH. J. Lu	---help---
29075fd92e65SH. J. Lu	  Include code to run binaries for the x32 native 32-bit ABI
29085fd92e65SH. J. Lu	  for 64-bit processors.  An x32 process gets access to the
29095fd92e65SH. J. Lu	  full 64-bit register file and wide data path while leaving
29105fd92e65SH. J. Lu	  pointers at 32 bits for smaller memory footprint.
29115fd92e65SH. J. Lu
29125fd92e65SH. J. Lu	  You will need a recent binutils (2.22 or later) with
29135fd92e65SH. J. Lu	  elf32_x86_64 support enabled to compile a kernel with this
29145fd92e65SH. J. Lu	  option set.
29155fd92e65SH. J. Lu
2916953fee1dSIngo Molnarconfig COMPAT_32
2917953fee1dSIngo Molnar	def_bool y
2918953fee1dSIngo Molnar	depends on IA32_EMULATION || X86_32
2919953fee1dSIngo Molnar	select HAVE_UID16
2920953fee1dSIngo Molnar	select OLD_SIGSUSPEND3
2921953fee1dSIngo Molnar
2922e279b6c1SSam Ravnborgconfig COMPAT
29233c2362e6SHarvey Harrison	def_bool y
29240bf62763SH. Peter Anvin	depends on IA32_EMULATION || X86_X32
2925e279b6c1SSam Ravnborg
29263120e25eSJan Beulichif COMPAT
2927e279b6c1SSam Ravnborgconfig COMPAT_FOR_U64_ALIGNMENT
29283120e25eSJan Beulich	def_bool y
2929e279b6c1SSam Ravnborg
2930e279b6c1SSam Ravnborgconfig SYSVIPC_COMPAT
29313c2362e6SHarvey Harrison	def_bool y
29323120e25eSJan Beulich	depends on SYSVIPC
29333120e25eSJan Beulichendif
2934ee009e4aSDavid Howells
2935e279b6c1SSam Ravnborgendmenu
2936e279b6c1SSam Ravnborg
2937e279b6c1SSam Ravnborg
2938e5beae16SKeith Packardconfig HAVE_ATOMIC_IOMAP
2939e5beae16SKeith Packard	def_bool y
2940e5beae16SKeith Packard	depends on X86_32
2941e5beae16SKeith Packard
29424692d77fSAlessandro Rubiniconfig X86_DEV_DMA_OPS
29434692d77fSAlessandro Rubini	bool
294483125a3aSAlessandro Rubini	depends on X86_64 || STA2X11
29454692d77fSAlessandro Rubini
2946f7219a53SAlessandro Rubiniconfig X86_DMA_REMAP
2947f7219a53SAlessandro Rubini	bool
294883125a3aSAlessandro Rubini	depends on STA2X11
2949f7219a53SAlessandro Rubini
2950e585513bSKirill A. Shutemovconfig HAVE_GENERIC_GUP
2951e585513bSKirill A. Shutemov	def_bool y
2952e585513bSKirill A. Shutemov
2953e279b6c1SSam Ravnborgsource "net/Kconfig"
2954e279b6c1SSam Ravnborg
2955e279b6c1SSam Ravnborgsource "drivers/Kconfig"
2956e279b6c1SSam Ravnborg
2957e279b6c1SSam Ravnborgsource "drivers/firmware/Kconfig"
2958e279b6c1SSam Ravnborg
2959e279b6c1SSam Ravnborgsource "fs/Kconfig"
2960e279b6c1SSam Ravnborg
2961e279b6c1SSam Ravnborgsource "arch/x86/Kconfig.debug"
2962e279b6c1SSam Ravnborg
2963e279b6c1SSam Ravnborgsource "security/Kconfig"
2964e279b6c1SSam Ravnborg
2965e279b6c1SSam Ravnborgsource "crypto/Kconfig"
2966e279b6c1SSam Ravnborg
2967edf88417SAvi Kivitysource "arch/x86/kvm/Kconfig"
2968edf88417SAvi Kivity
2969e279b6c1SSam Ravnborgsource "lib/Kconfig"
2970