xref: /linux/arch/x86/Kconfig (revision d5028ba8ee5a18c9d0bb926d883c28b370f89009)
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
8645471cd9SLinus Torvalds	select EDAC_ATOMIC_SCRUB
8745471cd9SLinus Torvalds	select EDAC_SUPPORT
886471b825SIngo Molnar	select GENERIC_CLOCKEVENTS
896471b825SIngo Molnar	select GENERIC_CLOCKEVENTS_BROADCAST	if X86_64 || (X86_32 && X86_LOCAL_APIC)
906471b825SIngo Molnar	select GENERIC_CLOCKEVENTS_MIN_ADJUST
916471b825SIngo Molnar	select GENERIC_CMOS_UPDATE
926471b825SIngo Molnar	select GENERIC_CPU_AUTOPROBE
9361dc0f55SThomas Gleixner	select GENERIC_CPU_VULNERABILITIES
946471b825SIngo Molnar	select GENERIC_EARLY_IOREMAP
956471b825SIngo Molnar	select GENERIC_FIND_FIRST_BIT
966471b825SIngo Molnar	select GENERIC_IOMAP
97c7d6c9ddSThomas Gleixner	select GENERIC_IRQ_EFFECTIVE_AFF_MASK	if SMP
980fa115daSThomas Gleixner	select GENERIC_IRQ_MATRIX_ALLOCATOR	if X86_LOCAL_APIC
99ad7a929fSThomas Gleixner	select GENERIC_IRQ_MIGRATION		if SMP
1006471b825SIngo Molnar	select GENERIC_IRQ_PROBE
101c201c917SThomas Gleixner	select GENERIC_IRQ_RESERVATION_MODE
1026471b825SIngo Molnar	select GENERIC_IRQ_SHOW
1036471b825SIngo Molnar	select GENERIC_PENDING_IRQ		if SMP
1046471b825SIngo Molnar	select GENERIC_SMP_IDLE_THREAD
1056471b825SIngo Molnar	select GENERIC_STRNCPY_FROM_USER
1066471b825SIngo Molnar	select GENERIC_STRNLEN_USER
1076471b825SIngo Molnar	select GENERIC_TIME_VSYSCALL
1087edaeb68SThomas Gleixner	select HARDLOCKUP_CHECK_TIMESTAMP	if X86_64
1096471b825SIngo Molnar	select HAVE_ACPI_APEI			if ACPI
1106471b825SIngo Molnar	select HAVE_ACPI_APEI_NMI		if ACPI
1116471b825SIngo Molnar	select HAVE_ALIGNED_STRUCT_PAGE		if SLUB
1126471b825SIngo Molnar	select HAVE_ARCH_AUDITSYSCALL
1136471b825SIngo Molnar	select HAVE_ARCH_HUGE_VMAP		if X86_64 || X86_PAE
1146471b825SIngo Molnar	select HAVE_ARCH_JUMP_LABEL
115d17a1d97SAndrey Ryabinin	select HAVE_ARCH_KASAN			if X86_64
1166471b825SIngo Molnar	select HAVE_ARCH_KGDB
1179e08f57dSDaniel Cashman	select HAVE_ARCH_MMAP_RND_BITS		if MMU
1189e08f57dSDaniel Cashman	select HAVE_ARCH_MMAP_RND_COMPAT_BITS	if MMU && COMPAT
1191b028f78SDmitry Safonov	select HAVE_ARCH_COMPAT_MMAP_BASES	if MMU && COMPAT
1206471b825SIngo Molnar	select HAVE_ARCH_SECCOMP_FILTER
121f7d83c1cSKees Cook	select HAVE_ARCH_THREAD_STRUCT_WHITELIST
1226471b825SIngo Molnar	select HAVE_ARCH_TRACEHOOK
1236471b825SIngo Molnar	select HAVE_ARCH_TRANSPARENT_HUGEPAGE
124a00cc7d9SMatthew Wilcox	select HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD if X86_64
125e37e43a4SAndy Lutomirski	select HAVE_ARCH_VMAP_STACK		if X86_64
126c763ea26SIngo Molnar	select HAVE_ARCH_WITHIN_STACK_FRAMES
1276471b825SIngo Molnar	select HAVE_CC_STACKPROTECTOR
1286471b825SIngo Molnar	select HAVE_CMPXCHG_DOUBLE
1296471b825SIngo Molnar	select HAVE_CMPXCHG_LOCAL
1306471b825SIngo Molnar	select HAVE_CONTEXT_TRACKING		if X86_64
131c1bd55f9SJosh Triplett	select HAVE_COPY_THREAD_TLS
1326471b825SIngo Molnar	select HAVE_C_RECORDMCOUNT
1336471b825SIngo Molnar	select HAVE_DEBUG_KMEMLEAK
1346471b825SIngo Molnar	select HAVE_DEBUG_STACKOVERFLOW
1356471b825SIngo Molnar	select HAVE_DMA_API_DEBUG
1369c5a3621SAkinobu Mita	select HAVE_DMA_CONTIGUOUS
137677aa9f7SSteven Rostedt	select HAVE_DYNAMIC_FTRACE
13806aeaaeaSMasami Hiramatsu	select HAVE_DYNAMIC_FTRACE_WITH_REGS
139c763ea26SIngo Molnar	select HAVE_EBPF_JIT			if X86_64
14058340a07SJohannes Berg	select HAVE_EFFICIENT_UNALIGNED_ACCESS
1415f56a5dfSJiri Slaby	select HAVE_EXIT_THREAD
142644e0e8dSSteven Rostedt (VMware)	select HAVE_FENTRY			if X86_64 || DYNAMIC_FTRACE
1436471b825SIngo Molnar	select HAVE_FTRACE_MCOUNT_RECORD
1446471b825SIngo Molnar	select HAVE_FUNCTION_GRAPH_TRACER
1456471b825SIngo Molnar	select HAVE_FUNCTION_TRACER
1466b90bd4bSEmese Revfy	select HAVE_GCC_PLUGINS
1470067f129SK.Prasad	select HAVE_HW_BREAKPOINT
1486471b825SIngo Molnar	select HAVE_IDE
1496471b825SIngo Molnar	select HAVE_IOREMAP_PROT
1506471b825SIngo Molnar	select HAVE_IRQ_EXIT_ON_IRQ_STACK	if X86_64
1516471b825SIngo Molnar	select HAVE_IRQ_TIME_ACCOUNTING
1526471b825SIngo Molnar	select HAVE_KERNEL_BZIP2
1536471b825SIngo Molnar	select HAVE_KERNEL_GZIP
1546471b825SIngo Molnar	select HAVE_KERNEL_LZ4
1556471b825SIngo Molnar	select HAVE_KERNEL_LZMA
1566471b825SIngo Molnar	select HAVE_KERNEL_LZO
1576471b825SIngo Molnar	select HAVE_KERNEL_XZ
1586471b825SIngo Molnar	select HAVE_KPROBES
1596471b825SIngo Molnar	select HAVE_KPROBES_ON_FTRACE
160540adea3SMasami Hiramatsu	select HAVE_FUNCTION_ERROR_INJECTION
1616471b825SIngo Molnar	select HAVE_KRETPROBES
1626471b825SIngo Molnar	select HAVE_KVM
1636471b825SIngo Molnar	select HAVE_LIVEPATCH			if X86_64
1646471b825SIngo Molnar	select HAVE_MEMBLOCK
1656471b825SIngo Molnar	select HAVE_MEMBLOCK_NODE_MAP
1660102752eSFrederic Weisbecker	select HAVE_MIXED_BREAKPOINTS_REGS
167ee9f8fceSJosh Poimboeuf	select HAVE_MOD_ARCH_SPECIFIC
16842a0bb3fSPetr Mladek	select HAVE_NMI
1696471b825SIngo Molnar	select HAVE_OPROFILE
1706471b825SIngo Molnar	select HAVE_OPTPROBES
1716471b825SIngo Molnar	select HAVE_PCSPKR_PLATFORM
1726471b825SIngo Molnar	select HAVE_PERF_EVENTS
173c01d4323SFrederic Weisbecker	select HAVE_PERF_EVENTS_NMI
17492e5aae4SNicholas Piggin	select HAVE_HARDLOCKUP_DETECTOR_PERF	if PERF_EVENTS && HAVE_PERF_EVENTS_NMI
175c5e63197SJiri Olsa	select HAVE_PERF_REGS
176c5ebcedbSJiri Olsa	select HAVE_PERF_USER_STACK_DUMP
1779e52fc2bSVitaly Kuznetsov	select HAVE_RCU_TABLE_FREE
1786471b825SIngo Molnar	select HAVE_REGS_AND_STACK_ACCESS_API
17911af8474SJosh Poimboeuf	select HAVE_RELIABLE_STACKTRACE		if X86_64 && UNWINDER_FRAME_POINTER && STACK_VALIDATION
180c763ea26SIngo Molnar	select HAVE_STACK_VALIDATION		if X86_64
1816471b825SIngo Molnar	select HAVE_SYSCALL_TRACEPOINTS
1826471b825SIngo Molnar	select HAVE_UNSTABLE_SCHED_CLOCK
1837c68af6eSAvi Kivity	select HAVE_USER_RETURN_NOTIFIER
184c0185808SThomas Gleixner	select IRQ_FORCED_THREADING
185df65c1bcSThomas Gleixner	select PCI_LOCKLESS_CONFIG
1866471b825SIngo Molnar	select PERF_EVENTS
1873195ef59SPrarit Bhargava	select RTC_LIB
188d6faca40SArnd Bergmann	select RTC_MC146818_LIB
1896471b825SIngo Molnar	select SPARSE_IRQ
19083fe27eaSPranith Kumar	select SRCU
1916471b825SIngo Molnar	select SYSCTL_EXCEPTION_TRACE
19215f4eae7SAndy Lutomirski	select THREAD_INFO_IN_TASK
1936471b825SIngo Molnar	select USER_STACKTRACE_SUPPORT
1946471b825SIngo Molnar	select VIRT_TO_BUS
1956471b825SIngo Molnar	select X86_FEATURE_NAMES		if PROC_FS
1967d8330a5SBalbir Singh
197ba7e4d13SIngo Molnarconfig INSTRUCTION_DECODER
1983120e25eSJan Beulich	def_bool y
1993120e25eSJan Beulich	depends on KPROBES || PERF_EVENTS || UPROBES
200ba7e4d13SIngo Molnar
20151b26adaSLinus Torvaldsconfig OUTPUT_FORMAT
20251b26adaSLinus Torvalds	string
20351b26adaSLinus Torvalds	default "elf32-i386" if X86_32
20451b26adaSLinus Torvalds	default "elf64-x86-64" if X86_64
20551b26adaSLinus Torvalds
20673531905SSam Ravnborgconfig ARCH_DEFCONFIG
207b9b39bfbSSam Ravnborg	string
20873531905SSam Ravnborg	default "arch/x86/configs/i386_defconfig" if X86_32
20973531905SSam Ravnborg	default "arch/x86/configs/x86_64_defconfig" if X86_64
210b9b39bfbSSam Ravnborg
2118d5fffb9SSam Ravnborgconfig LOCKDEP_SUPPORT
2123c2362e6SHarvey Harrison	def_bool y
2138d5fffb9SSam Ravnborg
2148d5fffb9SSam Ravnborgconfig STACKTRACE_SUPPORT
2153c2362e6SHarvey Harrison	def_bool y
2168d5fffb9SSam Ravnborg
2178d5fffb9SSam Ravnborgconfig MMU
2183c2362e6SHarvey Harrison	def_bool y
2198d5fffb9SSam Ravnborg
2209e08f57dSDaniel Cashmanconfig ARCH_MMAP_RND_BITS_MIN
2219e08f57dSDaniel Cashman	default 28 if 64BIT
2229e08f57dSDaniel Cashman	default 8
2239e08f57dSDaniel Cashman
2249e08f57dSDaniel Cashmanconfig ARCH_MMAP_RND_BITS_MAX
2259e08f57dSDaniel Cashman	default 32 if 64BIT
2269e08f57dSDaniel Cashman	default 16
2279e08f57dSDaniel Cashman
2289e08f57dSDaniel Cashmanconfig ARCH_MMAP_RND_COMPAT_BITS_MIN
2299e08f57dSDaniel Cashman	default 8
2309e08f57dSDaniel Cashman
2319e08f57dSDaniel Cashmanconfig ARCH_MMAP_RND_COMPAT_BITS_MAX
2329e08f57dSDaniel Cashman	default 16
2339e08f57dSDaniel Cashman
2348d5fffb9SSam Ravnborgconfig SBUS
2358d5fffb9SSam Ravnborg	bool
2368d5fffb9SSam Ravnborg
2373bc4e459SFUJITA Tomonoriconfig NEED_DMA_MAP_STATE
2383120e25eSJan Beulich	def_bool y
239a6dfa128SKonrad Rzeszutek Wilk	depends on X86_64 || INTEL_IOMMU || DMA_API_DEBUG || SWIOTLB
2403bc4e459SFUJITA Tomonori
24118e98307SFUJITA Tomonoriconfig NEED_SG_DMA_LENGTH
2424a14d84eSAndrew Morton	def_bool y
24318e98307SFUJITA Tomonori
2448d5fffb9SSam Ravnborgconfig GENERIC_ISA_DMA
2453120e25eSJan Beulich	def_bool y
2463120e25eSJan Beulich	depends on ISA_DMA_API
2478d5fffb9SSam Ravnborg
2488d5fffb9SSam Ravnborgconfig GENERIC_BUG
2493c2362e6SHarvey Harrison	def_bool y
2508d5fffb9SSam Ravnborg	depends on BUG
251b93a531eSJan Beulich	select GENERIC_BUG_RELATIVE_POINTERS if X86_64
252b93a531eSJan Beulich
253b93a531eSJan Beulichconfig GENERIC_BUG_RELATIVE_POINTERS
254b93a531eSJan Beulich	bool
2558d5fffb9SSam Ravnborg
2568d5fffb9SSam Ravnborgconfig GENERIC_HWEIGHT
2573c2362e6SHarvey Harrison	def_bool y
2588d5fffb9SSam Ravnborg
2598d5fffb9SSam Ravnborgconfig ARCH_MAY_HAVE_PC_FDC
2603120e25eSJan Beulich	def_bool y
2613120e25eSJan Beulich	depends on ISA_DMA_API
2628d5fffb9SSam Ravnborg
2631032c0baSSam Ravnborgconfig RWSEM_XCHGADD_ALGORITHM
2643120e25eSJan Beulich	def_bool y
2651032c0baSSam Ravnborg
2661032c0baSSam Ravnborgconfig GENERIC_CALIBRATE_DELAY
2671032c0baSSam Ravnborg	def_bool y
2681032c0baSSam Ravnborg
2699a0b8415Svenkatesh.pallipadi@intel.comconfig ARCH_HAS_CPU_RELAX
2709a0b8415Svenkatesh.pallipadi@intel.com	def_bool y
2718d5fffb9SSam Ravnborg
2721b27d05bSPekka Enbergconfig ARCH_HAS_CACHE_LINE_SIZE
2731b27d05bSPekka Enberg	def_bool y
2741b27d05bSPekka Enberg
275dd5af90aSMike Travisconfig HAVE_SETUP_PER_CPU_AREA
27689c9c4c5SBrian Gerst	def_bool y
277b32ef636Stravis@sgi.com
27808fc4580STejun Heoconfig NEED_PER_CPU_EMBED_FIRST_CHUNK
27908fc4580STejun Heo	def_bool y
28008fc4580STejun Heo
28108fc4580STejun Heoconfig NEED_PER_CPU_PAGE_FIRST_CHUNK
28211124411STejun Heo	def_bool y
28311124411STejun Heo
284801e4062SJohannes Bergconfig ARCH_HIBERNATION_POSSIBLE
285801e4062SJohannes Berg	def_bool y
286801e4062SJohannes Berg
287f4cb5700SJohannes Bergconfig ARCH_SUSPEND_POSSIBLE
288f4cb5700SJohannes Berg	def_bool y
289f4cb5700SJohannes Berg
290cfe28c5dSSteve Capperconfig ARCH_WANT_HUGE_PMD_SHARE
291cfe28c5dSSteve Capper	def_bool y
292cfe28c5dSSteve Capper
29353313b2cSSteve Capperconfig ARCH_WANT_GENERAL_HUGETLB
29453313b2cSSteve Capper	def_bool y
29553313b2cSSteve Capper
2968d5fffb9SSam Ravnborgconfig ZONE_DMA32
297e0fd24a3SJan Beulich	def_bool y if X86_64
2988d5fffb9SSam Ravnborg
2998d5fffb9SSam Ravnborgconfig AUDIT_ARCH
300e0fd24a3SJan Beulich	def_bool y if X86_64
3018d5fffb9SSam Ravnborg
302765c68bdSIngo Molnarconfig ARCH_SUPPORTS_OPTIMIZED_INLINING
303765c68bdSIngo Molnar	def_bool y
304765c68bdSIngo Molnar
3056a11f75bSAkinobu Mitaconfig ARCH_SUPPORTS_DEBUG_PAGEALLOC
3066a11f75bSAkinobu Mita	def_bool y
3076a11f75bSAkinobu Mita
308d6f2d75aSAndrey Ryabininconfig KASAN_SHADOW_OFFSET
309d6f2d75aSAndrey Ryabinin	hex
310d6f2d75aSAndrey Ryabinin	depends on KASAN
311d6f2d75aSAndrey Ryabinin	default 0xdffffc0000000000
312d6f2d75aSAndrey Ryabinin
31369575d38SShane Wangconfig HAVE_INTEL_TXT
31469575d38SShane Wang	def_bool y
3156ea30386SKees Cook	depends on INTEL_IOMMU && ACPI
31669575d38SShane Wang
3176b0c3d44SSam Ravnborgconfig X86_32_SMP
3186b0c3d44SSam Ravnborg	def_bool y
3196b0c3d44SSam Ravnborg	depends on X86_32 && SMP
3206b0c3d44SSam Ravnborg
3216b0c3d44SSam Ravnborgconfig X86_64_SMP
3226b0c3d44SSam Ravnborg	def_bool y
3236b0c3d44SSam Ravnborg	depends on X86_64 && SMP
3246b0c3d44SSam Ravnborg
325ccbeed3aSTejun Heoconfig X86_32_LAZY_GS
326ccbeed3aSTejun Heo	def_bool y
3272bc2f688SKees Cook	depends on X86_32 && CC_STACKPROTECTOR_NONE
328ccbeed3aSTejun Heo
3292b144498SSrikar Dronamrajuconfig ARCH_SUPPORTS_UPROBES
3302b144498SSrikar Dronamraju	def_bool y
3312b144498SSrikar Dronamraju
332d20642f0SRob Herringconfig FIX_EARLYCON_MEM
333d20642f0SRob Herring	def_bool y
334d20642f0SRob Herring
33598233368SKirill A. Shutemovconfig PGTABLE_LEVELS
33698233368SKirill A. Shutemov	int
33777ef56e4SKirill A. Shutemov	default 5 if X86_5LEVEL
33898233368SKirill A. Shutemov	default 4 if X86_64
33998233368SKirill A. Shutemov	default 3 if X86_PAE
34098233368SKirill A. Shutemov	default 2
34198233368SKirill A. Shutemov
342506f1d07SSam Ravnborgsource "init/Kconfig"
343dc52ddc0SMatt Helsleysource "kernel/Kconfig.freezer"
3448d5fffb9SSam Ravnborg
345506f1d07SSam Ravnborgmenu "Processor type and features"
346506f1d07SSam Ravnborg
3475ee71535SRandy Dunlapconfig ZONE_DMA
3485ee71535SRandy Dunlap	bool "DMA memory allocation support" if EXPERT
3495ee71535SRandy Dunlap	default y
3505ee71535SRandy Dunlap	help
3515ee71535SRandy Dunlap	  DMA memory allocation support allows devices with less than 32-bit
3525ee71535SRandy Dunlap	  addressing to allocate within the first 16MB of address space.
3535ee71535SRandy Dunlap	  Disable if no such devices will be used.
3545ee71535SRandy Dunlap
3555ee71535SRandy Dunlap	  If unsure, say Y.
3565ee71535SRandy Dunlap
357506f1d07SSam Ravnborgconfig SMP
358506f1d07SSam Ravnborg	bool "Symmetric multi-processing support"
359506f1d07SSam Ravnborg	---help---
360506f1d07SSam Ravnborg	  This enables support for systems with more than one CPU. If you have
3614a474157SRobert Graffham	  a system with only one CPU, say N. If you have a system with more
3624a474157SRobert Graffham	  than one CPU, say Y.
363506f1d07SSam Ravnborg
3644a474157SRobert Graffham	  If you say N here, the kernel will run on uni- and multiprocessor
365506f1d07SSam Ravnborg	  machines, but will use only one CPU of a multiprocessor machine. If
366506f1d07SSam Ravnborg	  you say Y here, the kernel will run on many, but not all,
3674a474157SRobert Graffham	  uniprocessor machines. On a uniprocessor machine, the kernel
368506f1d07SSam Ravnborg	  will run faster if you say N here.
369506f1d07SSam Ravnborg
370506f1d07SSam Ravnborg	  Note that if you say Y here and choose architecture "586" or
371506f1d07SSam Ravnborg	  "Pentium" under "Processor family", the kernel will not work on 486
372506f1d07SSam Ravnborg	  architectures. Similarly, multiprocessor kernels for the "PPro"
373506f1d07SSam Ravnborg	  architecture may not work on all Pentium based boards.
374506f1d07SSam Ravnborg
375506f1d07SSam Ravnborg	  People using multiprocessor machines who say Y here should also say
376506f1d07SSam Ravnborg	  Y to "Enhanced Real Time Clock Support", below. The "Advanced Power
377506f1d07SSam Ravnborg	  Management" code will be disabled if you say Y here.
378506f1d07SSam Ravnborg
379395cf969SPaul Bolle	  See also <file:Documentation/x86/i386/IO-APIC.txt>,
380c9525a3fSBenjamin Peterson	  <file:Documentation/lockup-watchdogs.txt> and the SMP-HOWTO available at
381506f1d07SSam Ravnborg	  <http://www.tldp.org/docs.html#howto>.
382506f1d07SSam Ravnborg
383506f1d07SSam Ravnborg	  If you don't know what to do here, say N.
384506f1d07SSam Ravnborg
3859def39beSJosh Triplettconfig X86_FEATURE_NAMES
3869def39beSJosh Triplett	bool "Processor feature human-readable names" if EMBEDDED
3879def39beSJosh Triplett	default y
3889def39beSJosh Triplett	---help---
3899def39beSJosh Triplett	  This option compiles in a table of x86 feature bits and corresponding
3909def39beSJosh Triplett	  names.  This is required to support /proc/cpuinfo and a few kernel
3919def39beSJosh Triplett	  messages.  You can disable this to save space, at the expense of
3929def39beSJosh Triplett	  making those few kernel messages show numeric feature bits instead.
3939def39beSJosh Triplett
3949def39beSJosh Triplett	  If in doubt, say Y.
3959def39beSJosh Triplett
3966e1315feSBorislav Petkovconfig X86_FAST_FEATURE_TESTS
3976e1315feSBorislav Petkov	bool "Fast CPU feature tests" if EMBEDDED
3986e1315feSBorislav Petkov	default y
3996e1315feSBorislav Petkov	---help---
4006e1315feSBorislav Petkov	  Some fast-paths in the kernel depend on the capabilities of the CPU.
4016e1315feSBorislav Petkov	  Say Y here for the kernel to patch in the appropriate code at runtime
4026e1315feSBorislav Petkov	  based on the capabilities of the CPU. The infrastructure for patching
4036e1315feSBorislav Petkov	  code at runtime takes up some additional space; space-constrained
4046e1315feSBorislav Petkov	  embedded systems may wish to say N here to produce smaller, slightly
4056e1315feSBorislav Petkov	  slower code.
4066e1315feSBorislav Petkov
40706cd9a7dSYinghai Luconfig X86_X2APIC
40806cd9a7dSYinghai Lu	bool "Support x2apic"
40919e3d60dSJan Kiszka	depends on X86_LOCAL_APIC && X86_64 && (IRQ_REMAP || HYPERVISOR_GUEST)
41006cd9a7dSYinghai Lu	---help---
41106cd9a7dSYinghai Lu	  This enables x2apic support on CPUs that have this feature.
41206cd9a7dSYinghai Lu
41306cd9a7dSYinghai Lu	  This allows 32-bit apic IDs (so it can support very large systems),
41406cd9a7dSYinghai Lu	  and accesses the local apic via MSRs not via mmio.
41506cd9a7dSYinghai Lu
41606cd9a7dSYinghai Lu	  If you don't know what to do here, say N.
41706cd9a7dSYinghai Lu
4186695c85bSYinghai Luconfig X86_MPPARSE
4196e87f9b7SBin Gao	bool "Enable MPS table" if ACPI || SFI
4207a527688SJan Beulich	default y
4215ab74722SIngo Molnar	depends on X86_LOCAL_APIC
4228f9ca475SIngo Molnar	---help---
4236695c85bSYinghai Lu	  For old smp systems that do not have proper acpi support. Newer systems
4246695c85bSYinghai Lu	  (esp with 64bit cpus) with acpi support, MADT and DSDT will override it
4256695c85bSYinghai Lu
42626f7ef14SYinghai Luconfig X86_BIGSMP
42726f7ef14SYinghai Lu	bool "Support for big SMP systems with more than 8 CPUs"
42826f7ef14SYinghai Lu	depends on X86_32 && SMP
4298f9ca475SIngo Molnar	---help---
43026f7ef14SYinghai Lu	  This option is needed for the systems that have more than 8 CPUs
431506f1d07SSam Ravnborg
432ddd70cf9SJun Nakajimaconfig GOLDFISH
433ddd70cf9SJun Nakajima       def_bool y
434ddd70cf9SJun Nakajima       depends on X86_GOLDFISH
435ddd70cf9SJun Nakajima
43676b04384SDavid Woodhouseconfig RETPOLINE
43776b04384SDavid Woodhouse	bool "Avoid speculative indirect branches in kernel"
43876b04384SDavid Woodhouse	default y
439*d5028ba8SPeter Zijlstra	select STACK_VALIDATION if HAVE_STACK_VALIDATION
44076b04384SDavid Woodhouse	help
44176b04384SDavid Woodhouse	  Compile kernel with the retpoline compiler options to guard against
44276b04384SDavid Woodhouse	  kernel-to-user data leaks by avoiding speculative indirect
44376b04384SDavid Woodhouse	  branches. Requires a compiler with -mindirect-branch=thunk-extern
44476b04384SDavid Woodhouse	  support for full protection. The kernel may run slower.
44576b04384SDavid Woodhouse
44676b04384SDavid Woodhouse	  Without compiler support, at least indirect branches in assembler
44776b04384SDavid Woodhouse	  code are eliminated. Since this includes the syscall entry path,
44876b04384SDavid Woodhouse	  it is not entirely pointless.
44976b04384SDavid Woodhouse
450f01d7d51SVikas Shivappaconfig INTEL_RDT
451f01d7d51SVikas Shivappa	bool "Intel Resource Director Technology support"
45278e99b4aSFenghua Yu	default n
45378e99b4aSFenghua Yu	depends on X86 && CPU_SUP_INTEL
45459fe5a77SThomas Gleixner	select KERNFS
45578e99b4aSFenghua Yu	help
456f01d7d51SVikas Shivappa	  Select to enable resource allocation and monitoring which are
457f01d7d51SVikas Shivappa	  sub-features of Intel Resource Director Technology(RDT). More
458f01d7d51SVikas Shivappa	  information about RDT can be found in the Intel x86
459f01d7d51SVikas Shivappa	  Architecture Software Developer Manual.
46078e99b4aSFenghua Yu
46178e99b4aSFenghua Yu	  Say N if unsure.
46278e99b4aSFenghua Yu
4638425091fSRavikiran G Thirumalaiif X86_32
464c5c606d9SRavikiran G Thirumalaiconfig X86_EXTENDED_PLATFORM
465c5c606d9SRavikiran G Thirumalai	bool "Support for extended (non-PC) x86 platforms"
466c5c606d9SRavikiran G Thirumalai	default y
4678f9ca475SIngo Molnar	---help---
46806ac8346SIngo Molnar	  If you disable this option then the kernel will only support
46906ac8346SIngo Molnar	  standard PC platforms. (which covers the vast majority of
47006ac8346SIngo Molnar	  systems out there.)
47106ac8346SIngo Molnar
4728425091fSRavikiran G Thirumalai	  If you enable this option then you'll be able to select support
4738425091fSRavikiran G Thirumalai	  for the following (non-PC) 32 bit x86 platforms:
474cb7b8023SBen Hutchings		Goldfish (Android emulator)
4758425091fSRavikiran G Thirumalai		AMD Elan
4768425091fSRavikiran G Thirumalai		RDC R-321x SoC
4778425091fSRavikiran G Thirumalai		SGI 320/540 (Visual Workstation)
47883125a3aSAlessandro Rubini		STA2X11-based (e.g. Northville)
4793f4110a4SThomas Gleixner		Moorestown MID devices
48006ac8346SIngo Molnar
48106ac8346SIngo Molnar	  If you have one of these systems, or if you want to build a
48206ac8346SIngo Molnar	  generic distribution kernel, say Y here - otherwise say N.
4838425091fSRavikiran G Thirumalaiendif
48406ac8346SIngo Molnar
4858425091fSRavikiran G Thirumalaiif X86_64
4868425091fSRavikiran G Thirumalaiconfig X86_EXTENDED_PLATFORM
4878425091fSRavikiran G Thirumalai	bool "Support for extended (non-PC) x86 platforms"
4888425091fSRavikiran G Thirumalai	default y
4898425091fSRavikiran G Thirumalai	---help---
4908425091fSRavikiran G Thirumalai	  If you disable this option then the kernel will only support
4918425091fSRavikiran G Thirumalai	  standard PC platforms. (which covers the vast majority of
4928425091fSRavikiran G Thirumalai	  systems out there.)
4938425091fSRavikiran G Thirumalai
4948425091fSRavikiran G Thirumalai	  If you enable this option then you'll be able to select support
4958425091fSRavikiran G Thirumalai	  for the following (non-PC) 64 bit x86 platforms:
49644b111b5SSteffen Persvold		Numascale NumaChip
4978425091fSRavikiran G Thirumalai		ScaleMP vSMP
4988425091fSRavikiran G Thirumalai		SGI Ultraviolet
4998425091fSRavikiran G Thirumalai
5008425091fSRavikiran G Thirumalai	  If you have one of these systems, or if you want to build a
5018425091fSRavikiran G Thirumalai	  generic distribution kernel, say Y here - otherwise say N.
5028425091fSRavikiran G Thirumalaiendif
503c5c606d9SRavikiran G Thirumalai# This is an alphabetically sorted list of 64 bit extended platforms
504c5c606d9SRavikiran G Thirumalai# Please maintain the alphabetic order if and when there are additions
50544b111b5SSteffen Persvoldconfig X86_NUMACHIP
50644b111b5SSteffen Persvold	bool "Numascale NumaChip"
50744b111b5SSteffen Persvold	depends on X86_64
50844b111b5SSteffen Persvold	depends on X86_EXTENDED_PLATFORM
50944b111b5SSteffen Persvold	depends on NUMA
51044b111b5SSteffen Persvold	depends on SMP
51144b111b5SSteffen Persvold	depends on X86_X2APIC
512f9726bfdSDaniel J Blueman	depends on PCI_MMCONFIG
51344b111b5SSteffen Persvold	---help---
51444b111b5SSteffen Persvold	  Adds support for Numascale NumaChip large-SMP systems. Needed to
51544b111b5SSteffen Persvold	  enable more than ~168 cores.
51644b111b5SSteffen Persvold	  If you don't have one of these, you should say N here.
51703b48632SNick Piggin
5186a48565eSIngo Molnarconfig X86_VSMP
519c5c606d9SRavikiran G Thirumalai	bool "ScaleMP vSMP"
5206276a074SBorislav Petkov	select HYPERVISOR_GUEST
5216a48565eSIngo Molnar	select PARAVIRT
5226a48565eSIngo Molnar	depends on X86_64 && PCI
523c5c606d9SRavikiran G Thirumalai	depends on X86_EXTENDED_PLATFORM
524ead91d4bSShai Fultheim	depends on SMP
5258f9ca475SIngo Molnar	---help---
5266a48565eSIngo Molnar	  Support for ScaleMP vSMP systems.  Say 'Y' here if this kernel is
5276a48565eSIngo Molnar	  supposed to run on these EM64T-based machines.  Only choose this option
5286a48565eSIngo Molnar	  if you have one of these machines.
5296a48565eSIngo Molnar
530c5c606d9SRavikiran G Thirumalaiconfig X86_UV
531c5c606d9SRavikiran G Thirumalai	bool "SGI Ultraviolet"
532c5c606d9SRavikiran G Thirumalai	depends on X86_64
533c5c606d9SRavikiran G Thirumalai	depends on X86_EXTENDED_PLATFORM
53454c28d29SJack Steiner	depends on NUMA
5351ecb4ae5SAndrew Morton	depends on EFI
5369d6c26e7SSuresh Siddha	depends on X86_X2APIC
5371222e564SIngo Molnar	depends on PCI
538c5c606d9SRavikiran G Thirumalai	---help---
539c5c606d9SRavikiran G Thirumalai	  This option is needed in order to support SGI Ultraviolet systems.
540c5c606d9SRavikiran G Thirumalai	  If you don't have one of these, you should say N here.
541c5c606d9SRavikiran G Thirumalai
542c5c606d9SRavikiran G Thirumalai# Following is an alphabetically sorted list of 32 bit extended platforms
543c5c606d9SRavikiran G Thirumalai# Please maintain the alphabetic order if and when there are additions
544506f1d07SSam Ravnborg
545ddd70cf9SJun Nakajimaconfig X86_GOLDFISH
546ddd70cf9SJun Nakajima       bool "Goldfish (Virtual Platform)"
547cb7b8023SBen Hutchings       depends on X86_EXTENDED_PLATFORM
548ddd70cf9SJun Nakajima       ---help---
549ddd70cf9SJun Nakajima	 Enable support for the Goldfish virtual platform used primarily
550ddd70cf9SJun Nakajima	 for Android development. Unless you are building for the Android
551ddd70cf9SJun Nakajima	 Goldfish emulator say N here.
552ddd70cf9SJun Nakajima
553c751e17bSThomas Gleixnerconfig X86_INTEL_CE
554c751e17bSThomas Gleixner	bool "CE4100 TV platform"
555c751e17bSThomas Gleixner	depends on PCI
556c751e17bSThomas Gleixner	depends on PCI_GODIRECT
5576084a6e2SJiang Liu	depends on X86_IO_APIC
558c751e17bSThomas Gleixner	depends on X86_32
559c751e17bSThomas Gleixner	depends on X86_EXTENDED_PLATFORM
56037bc9f50SDirk Brandewie	select X86_REBOOTFIXUPS
561da6b737bSSebastian Andrzej Siewior	select OF
562da6b737bSSebastian Andrzej Siewior	select OF_EARLY_FLATTREE
563c751e17bSThomas Gleixner	---help---
564c751e17bSThomas Gleixner	  Select for the Intel CE media processor (CE4100) SOC.
565c751e17bSThomas Gleixner	  This option compiles in support for the CE4100 SOC for settop
566c751e17bSThomas Gleixner	  boxes and media devices.
567c751e17bSThomas Gleixner
5684cb9b00fSDavid Cohenconfig X86_INTEL_MID
56943605ef1SAlan Cox	bool "Intel MID platform support"
57043605ef1SAlan Cox	depends on X86_EXTENDED_PLATFORM
571edc6bc78SDavid Cohen	depends on X86_PLATFORM_DEVICES
5721ea7c673SAlan Cox	depends on PCI
5733fda5bb4SAndy Shevchenko	depends on X86_64 || (PCI_GOANY && X86_32)
5741ea7c673SAlan Cox	depends on X86_IO_APIC
5757c9c3a1eSAlan Cox	select SFI
5764cb9b00fSDavid Cohen	select I2C
5777c9c3a1eSAlan Cox	select DW_APB_TIMER
5781ea7c673SAlan Cox	select APB_TIMER
5791ea7c673SAlan Cox	select INTEL_SCU_IPC
58015a713dfSMika Westerberg	select MFD_INTEL_MSIC
5811ea7c673SAlan Cox	---help---
5824cb9b00fSDavid Cohen	  Select to build a kernel capable of supporting Intel MID (Mobile
5834cb9b00fSDavid Cohen	  Internet Device) platform systems which do not have the PCI legacy
5844cb9b00fSDavid Cohen	  interfaces. If you are building for a PC class system say N here.
5851ea7c673SAlan Cox
5864cb9b00fSDavid Cohen	  Intel MID platforms are based on an Intel processor and chipset which
5874cb9b00fSDavid Cohen	  consume less power than most of the x86 derivatives.
58843605ef1SAlan Cox
5898bbc2a13SBryan O'Donoghueconfig X86_INTEL_QUARK
5908bbc2a13SBryan O'Donoghue	bool "Intel Quark platform support"
5918bbc2a13SBryan O'Donoghue	depends on X86_32
5928bbc2a13SBryan O'Donoghue	depends on X86_EXTENDED_PLATFORM
5938bbc2a13SBryan O'Donoghue	depends on X86_PLATFORM_DEVICES
5948bbc2a13SBryan O'Donoghue	depends on X86_TSC
5958bbc2a13SBryan O'Donoghue	depends on PCI
5968bbc2a13SBryan O'Donoghue	depends on PCI_GOANY
5978bbc2a13SBryan O'Donoghue	depends on X86_IO_APIC
5988bbc2a13SBryan O'Donoghue	select IOSF_MBI
5998bbc2a13SBryan O'Donoghue	select INTEL_IMR
6009ab6eb51SAndy Shevchenko	select COMMON_CLK
6018bbc2a13SBryan O'Donoghue	---help---
6028bbc2a13SBryan O'Donoghue	  Select to include support for Quark X1000 SoC.
6038bbc2a13SBryan O'Donoghue	  Say Y here if you have a Quark based system such as the Arduino
6048bbc2a13SBryan O'Donoghue	  compatible Intel Galileo.
6058bbc2a13SBryan O'Donoghue
6063d48aab1SMika Westerbergconfig X86_INTEL_LPSS
6073d48aab1SMika Westerberg	bool "Intel Low Power Subsystem Support"
608eebb3e8dSAndy Shevchenko	depends on X86 && ACPI
6093d48aab1SMika Westerberg	select COMMON_CLK
6100f531431SMathias Nyman	select PINCTRL
611eebb3e8dSAndy Shevchenko	select IOSF_MBI
6123d48aab1SMika Westerberg	---help---
6133d48aab1SMika Westerberg	  Select to build support for Intel Low Power Subsystem such as
6143d48aab1SMika Westerberg	  found on Intel Lynxpoint PCH. Selecting this option enables
6150f531431SMathias Nyman	  things like clock tree (common clock framework) and pincontrol
6160f531431SMathias Nyman	  which are needed by the LPSS peripheral drivers.
6173d48aab1SMika Westerberg
61892082a88SKen Xueconfig X86_AMD_PLATFORM_DEVICE
61992082a88SKen Xue	bool "AMD ACPI2Platform devices support"
62092082a88SKen Xue	depends on ACPI
62192082a88SKen Xue	select COMMON_CLK
62292082a88SKen Xue	select PINCTRL
62392082a88SKen Xue	---help---
62492082a88SKen Xue	  Select to interpret AMD specific ACPI device to platform device
62592082a88SKen Xue	  such as I2C, UART, GPIO found on AMD Carrizo and later chipsets.
62692082a88SKen Xue	  I2C and UART depend on COMMON_CLK to set clock. GPIO driver is
62792082a88SKen Xue	  implemented under PINCTRL subsystem.
62892082a88SKen Xue
629ced3ce76SDavid E. Boxconfig IOSF_MBI
630ced3ce76SDavid E. Box	tristate "Intel SoC IOSF Sideband support for SoC platforms"
631ced3ce76SDavid E. Box	depends on PCI
632ced3ce76SDavid E. Box	---help---
633ced3ce76SDavid E. Box	  This option enables sideband register access support for Intel SoC
634ced3ce76SDavid E. Box	  platforms. On these platforms the IOSF sideband is used in lieu of
635ced3ce76SDavid E. Box	  MSR's for some register accesses, mostly but not limited to thermal
636ced3ce76SDavid E. Box	  and power. Drivers may query the availability of this device to
637ced3ce76SDavid E. Box	  determine if they need the sideband in order to work on these
638ced3ce76SDavid E. Box	  platforms. The sideband is available on the following SoC products.
639ced3ce76SDavid E. Box	  This list is not meant to be exclusive.
640ced3ce76SDavid E. Box	   - BayTrail
641ced3ce76SDavid E. Box	   - Braswell
642ced3ce76SDavid E. Box	   - Quark
643ced3ce76SDavid E. Box
644ced3ce76SDavid E. Box	  You should say Y if you are running a kernel on one of these SoC's.
645ced3ce76SDavid E. Box
646ed2226bdSDavid E. Boxconfig IOSF_MBI_DEBUG
647ed2226bdSDavid E. Box	bool "Enable IOSF sideband access through debugfs"
648ed2226bdSDavid E. Box	depends on IOSF_MBI && DEBUG_FS
649ed2226bdSDavid E. Box	---help---
650ed2226bdSDavid E. Box	  Select this option to expose the IOSF sideband access registers (MCR,
651ed2226bdSDavid E. Box	  MDR, MCRX) through debugfs to write and read register information from
652ed2226bdSDavid E. Box	  different units on the SoC. This is most useful for obtaining device
653ed2226bdSDavid E. Box	  state information for debug and analysis. As this is a general access
654ed2226bdSDavid E. Box	  mechanism, users of this option would have specific knowledge of the
655ed2226bdSDavid E. Box	  device they want to access.
656ed2226bdSDavid E. Box
657ed2226bdSDavid E. Box	  If you don't require the option or are in doubt, say N.
658ed2226bdSDavid E. Box
659c5c606d9SRavikiran G Thirumalaiconfig X86_RDC321X
660c5c606d9SRavikiran G Thirumalai	bool "RDC R-321x SoC"
661506f1d07SSam Ravnborg	depends on X86_32
662c5c606d9SRavikiran G Thirumalai	depends on X86_EXTENDED_PLATFORM
663c5c606d9SRavikiran G Thirumalai	select M486
664c5c606d9SRavikiran G Thirumalai	select X86_REBOOTFIXUPS
665c5c606d9SRavikiran G Thirumalai	---help---
666c5c606d9SRavikiran G Thirumalai	  This option is needed for RDC R-321x system-on-chip, also known
667c5c606d9SRavikiran G Thirumalai	  as R-8610-(G).
668c5c606d9SRavikiran G Thirumalai	  If you don't have one of these chips, you should say N here.
669c5c606d9SRavikiran G Thirumalai
670e0c7ae37SIngo Molnarconfig X86_32_NON_STANDARD
6719c398017SIngo Molnar	bool "Support non-standard 32-bit SMP architectures"
6729c398017SIngo Molnar	depends on X86_32 && SMP
673c5c606d9SRavikiran G Thirumalai	depends on X86_EXTENDED_PLATFORM
6748f9ca475SIngo Molnar	---help---
675b5660ba7SH. Peter Anvin	  This option compiles in the bigsmp and STA2X11 default
676b5660ba7SH. Peter Anvin	  subarchitectures.  It is intended for a generic binary
677b5660ba7SH. Peter Anvin	  kernel. If you select them all, kernel will probe it one by
678b5660ba7SH. Peter Anvin	  one and will fallback to default.
679d49c4288SYinghai Lu
680c5c606d9SRavikiran G Thirumalai# Alphabetically sorted list of Non standard 32 bit platforms
681d49c4288SYinghai Lu
682d949f36fSLinus Torvaldsconfig X86_SUPPORTS_MEMORY_FAILURE
6836fc108a0SJan Beulich	def_bool y
684d949f36fSLinus Torvalds	# MCE code calls memory_failure():
685d949f36fSLinus Torvalds	depends on X86_MCE
686d949f36fSLinus Torvalds	# On 32-bit this adds too big of NODES_SHIFT and we run out of page flags:
687d949f36fSLinus Torvalds	# On 32-bit SPARSEMEM adds too big of SECTIONS_WIDTH:
688d949f36fSLinus Torvalds	depends on X86_64 || !SPARSEMEM
689d949f36fSLinus Torvalds	select ARCH_SUPPORTS_MEMORY_FAILURE
690d949f36fSLinus Torvalds
69183125a3aSAlessandro Rubiniconfig STA2X11
69283125a3aSAlessandro Rubini	bool "STA2X11 Companion Chip Support"
69383125a3aSAlessandro Rubini	depends on X86_32_NON_STANDARD && PCI
69483125a3aSAlessandro Rubini	select X86_DEV_DMA_OPS
69583125a3aSAlessandro Rubini	select X86_DMA_REMAP
69683125a3aSAlessandro Rubini	select SWIOTLB
69783125a3aSAlessandro Rubini	select MFD_STA2X11
6980145071bSLinus Walleij	select GPIOLIB
69983125a3aSAlessandro Rubini	default n
70083125a3aSAlessandro Rubini	---help---
70183125a3aSAlessandro Rubini	  This adds support for boards based on the STA2X11 IO-Hub,
70283125a3aSAlessandro Rubini	  a.k.a. "ConneXt". The chip is used in place of the standard
70383125a3aSAlessandro Rubini	  PC chipset, so all "standard" peripherals are missing. If this
70483125a3aSAlessandro Rubini	  option is selected the kernel will still be able to boot on
70583125a3aSAlessandro Rubini	  standard PC machines.
70683125a3aSAlessandro Rubini
70782148d1dSShérabconfig X86_32_IRIS
70882148d1dSShérab	tristate "Eurobraille/Iris poweroff module"
70982148d1dSShérab	depends on X86_32
71082148d1dSShérab	---help---
71182148d1dSShérab	  The Iris machines from EuroBraille do not have APM or ACPI support
71282148d1dSShérab	  to shut themselves down properly.  A special I/O sequence is
71382148d1dSShérab	  needed to do so, which is what this module does at
71482148d1dSShérab	  kernel shutdown.
71582148d1dSShérab
71682148d1dSShérab	  This is only for Iris machines from EuroBraille.
71782148d1dSShérab
71882148d1dSShérab	  If unused, say N.
71982148d1dSShérab
720ae1e9130SIngo Molnarconfig SCHED_OMIT_FRAME_POINTER
7213c2362e6SHarvey Harrison	def_bool y
7223c2362e6SHarvey Harrison	prompt "Single-depth WCHAN output"
723a87d0914SKen Chen	depends on X86
7248f9ca475SIngo Molnar	---help---
725506f1d07SSam Ravnborg	  Calculate simpler /proc/<PID>/wchan values. If this option
726506f1d07SSam Ravnborg	  is disabled then wchan values will recurse back to the
727506f1d07SSam Ravnborg	  caller function. This provides more accurate wchan values,
728506f1d07SSam Ravnborg	  at the expense of slightly more scheduling overhead.
729506f1d07SSam Ravnborg
730506f1d07SSam Ravnborg	  If in doubt, say "Y".
731506f1d07SSam Ravnborg
7326276a074SBorislav Petkovmenuconfig HYPERVISOR_GUEST
7336276a074SBorislav Petkov	bool "Linux guest support"
7348f9ca475SIngo Molnar	---help---
7356276a074SBorislav Petkov	  Say Y here to enable options for running Linux under various hyper-
7366276a074SBorislav Petkov	  visors. This option enables basic hypervisor detection and platform
7376276a074SBorislav Petkov	  setup.
738506f1d07SSam Ravnborg
7396276a074SBorislav Petkov	  If you say N, all options in this submenu will be skipped and
7406276a074SBorislav Petkov	  disabled, and Linux guest support won't be built in.
741506f1d07SSam Ravnborg
7426276a074SBorislav Petkovif HYPERVISOR_GUEST
743506f1d07SSam Ravnborg
744e61bd94aSEduardo Pereira Habkostconfig PARAVIRT
745e61bd94aSEduardo Pereira Habkost	bool "Enable paravirtualization code"
7468f9ca475SIngo Molnar	---help---
747e61bd94aSEduardo Pereira Habkost	  This changes the kernel so it can modify itself when it is run
748e61bd94aSEduardo Pereira Habkost	  under a hypervisor, potentially improving performance significantly
749e61bd94aSEduardo Pereira Habkost	  over full virtualization.  However, when run without a hypervisor
750e61bd94aSEduardo Pereira Habkost	  the kernel is theoretically slower and slightly larger.
751e61bd94aSEduardo Pereira Habkost
7526276a074SBorislav Petkovconfig PARAVIRT_DEBUG
7536276a074SBorislav Petkov	bool "paravirt-ops debugging"
7546276a074SBorislav Petkov	depends on PARAVIRT && DEBUG_KERNEL
7556276a074SBorislav Petkov	---help---
7566276a074SBorislav Petkov	  Enable to debug paravirt_ops internals.  Specifically, BUG if
7576276a074SBorislav Petkov	  a paravirt_op is missing when it is called.
7586276a074SBorislav Petkov
759b4ecc126SJeremy Fitzhardingeconfig PARAVIRT_SPINLOCKS
760b4ecc126SJeremy Fitzhardinge	bool "Paravirtualization layer for spinlocks"
7616ea30386SKees Cook	depends on PARAVIRT && SMP
762b4ecc126SJeremy Fitzhardinge	---help---
763b4ecc126SJeremy Fitzhardinge	  Paravirtualized spinlocks allow a pvops backend to replace the
764b4ecc126SJeremy Fitzhardinge	  spinlock implementation with something virtualization-friendly
765b4ecc126SJeremy Fitzhardinge	  (for example, block the virtual CPU rather than spinning).
766b4ecc126SJeremy Fitzhardinge
7674c4e4f61SRaghavendra K T	  It has a minimal impact on native kernels and gives a nice performance
7684c4e4f61SRaghavendra K T	  benefit on paravirtualized KVM / Xen kernels.
769b4ecc126SJeremy Fitzhardinge
7704c4e4f61SRaghavendra K T	  If you are unsure how to answer this question, answer Y.
771b4ecc126SJeremy Fitzhardinge
77245e898b7SWaiman Longconfig QUEUED_LOCK_STAT
77345e898b7SWaiman Long	bool "Paravirt queued spinlock statistics"
774cfd8983fSPeter Zijlstra	depends on PARAVIRT_SPINLOCKS && DEBUG_FS
77545e898b7SWaiman Long	---help---
77645e898b7SWaiman Long	  Enable the collection of statistical data on the slowpath
77745e898b7SWaiman Long	  behavior of paravirtualized queued spinlocks and report
77845e898b7SWaiman Long	  them on debugfs.
77945e898b7SWaiman Long
7806276a074SBorislav Petkovsource "arch/x86/xen/Kconfig"
7816276a074SBorislav Petkov
7826276a074SBorislav Petkovconfig KVM_GUEST
7836276a074SBorislav Petkov	bool "KVM Guest support (including kvmclock)"
7846276a074SBorislav Petkov	depends on PARAVIRT
7856276a074SBorislav Petkov	select PARAVIRT_CLOCK
7866276a074SBorislav Petkov	default y
7876276a074SBorislav Petkov	---help---
7886276a074SBorislav Petkov	  This option enables various optimizations for running under the KVM
7896276a074SBorislav Petkov	  hypervisor. It includes a paravirtualized clock, so that instead
7906276a074SBorislav Petkov	  of relying on a PIT (or probably other) emulation by the
7916276a074SBorislav Petkov	  underlying device model, the host provides the guest with
7926276a074SBorislav Petkov	  timing infrastructure such as time of day, and system time
7936276a074SBorislav Petkov
7941e20eb85SSrivatsa Vaddagiriconfig KVM_DEBUG_FS
7951e20eb85SSrivatsa Vaddagiri	bool "Enable debug information for KVM Guests in debugfs"
7961e20eb85SSrivatsa Vaddagiri	depends on KVM_GUEST && DEBUG_FS
7971e20eb85SSrivatsa Vaddagiri	default n
7981e20eb85SSrivatsa Vaddagiri	---help---
7991e20eb85SSrivatsa Vaddagiri	  This option enables collection of various statistics for KVM guest.
8001e20eb85SSrivatsa Vaddagiri	  Statistics are displayed in debugfs filesystem. Enabling this option
8011e20eb85SSrivatsa Vaddagiri	  may incur significant overhead.
8021e20eb85SSrivatsa Vaddagiri
8036276a074SBorislav Petkovconfig PARAVIRT_TIME_ACCOUNTING
8046276a074SBorislav Petkov	bool "Paravirtual steal time accounting"
8056276a074SBorislav Petkov	depends on PARAVIRT
8066276a074SBorislav Petkov	default n
8076276a074SBorislav Petkov	---help---
8086276a074SBorislav Petkov	  Select this option to enable fine granularity task steal time
8096276a074SBorislav Petkov	  accounting. Time spent executing other tasks in parallel with
8106276a074SBorislav Petkov	  the current vCPU is discounted from the vCPU power. To account for
8116276a074SBorislav Petkov	  that, there can be a small performance impact.
8126276a074SBorislav Petkov
8136276a074SBorislav Petkov	  If in doubt, say N here.
8146276a074SBorislav Petkov
8157af192c9SGerd Hoffmannconfig PARAVIRT_CLOCK
8167af192c9SGerd Hoffmann	bool
8177af192c9SGerd Hoffmann
8184a362601SJan Kiszkaconfig JAILHOUSE_GUEST
8194a362601SJan Kiszka	bool "Jailhouse non-root cell support"
820abde587bSArnd Bergmann	depends on X86_64 && PCI
82187e65d05SJan Kiszka	select X86_PM_TIMER
8224a362601SJan Kiszka	---help---
8234a362601SJan Kiszka	  This option allows to run Linux as guest in a Jailhouse non-root
8244a362601SJan Kiszka	  cell. You can leave this option disabled if you only want to start
8254a362601SJan Kiszka	  Jailhouse and run Linux afterwards in the root cell.
8264a362601SJan Kiszka
8276276a074SBorislav Petkovendif #HYPERVISOR_GUEST
82897349135SJeremy Fitzhardinge
82908677214SYinghai Luconfig NO_BOOTMEM
830774ea0bcSYinghai Lu	def_bool y
83108677214SYinghai Lu
832506f1d07SSam Ravnborgsource "arch/x86/Kconfig.cpu"
833506f1d07SSam Ravnborg
834506f1d07SSam Ravnborgconfig HPET_TIMER
8353c2362e6SHarvey Harrison	def_bool X86_64
836506f1d07SSam Ravnborg	prompt "HPET Timer Support" if X86_32
8378f9ca475SIngo Molnar	---help---
838506f1d07SSam Ravnborg	  Use the IA-PC HPET (High Precision Event Timer) to manage
839506f1d07SSam Ravnborg	  time in preference to the PIT and RTC, if a HPET is
840506f1d07SSam Ravnborg	  present.
841506f1d07SSam Ravnborg	  HPET is the next generation timer replacing legacy 8254s.
842506f1d07SSam Ravnborg	  The HPET provides a stable time base on SMP
843506f1d07SSam Ravnborg	  systems, unlike the TSC, but it is more expensive to access,
8444e7f9df2SMichael S. Tsirkin	  as it is off-chip.  The interface used is documented
8454e7f9df2SMichael S. Tsirkin	  in the HPET spec, revision 1.
846506f1d07SSam Ravnborg
847506f1d07SSam Ravnborg	  You can safely choose Y here.  However, HPET will only be
848506f1d07SSam Ravnborg	  activated if the platform and the BIOS support this feature.
849506f1d07SSam Ravnborg	  Otherwise the 8254 will be used for timing services.
850506f1d07SSam Ravnborg
851506f1d07SSam Ravnborg	  Choose N to continue using the legacy 8254 timer.
852506f1d07SSam Ravnborg
853506f1d07SSam Ravnborgconfig HPET_EMULATE_RTC
8543c2362e6SHarvey Harrison	def_bool y
8559d8af78bSBernhard Walle	depends on HPET_TIMER && (RTC=y || RTC=m || RTC_DRV_CMOS=m || RTC_DRV_CMOS=y)
856506f1d07SSam Ravnborg
857bb24c471SJacob Panconfig APB_TIMER
858933b9463SAlan Cox       def_bool y if X86_INTEL_MID
859933b9463SAlan Cox       prompt "Intel MID APB Timer Support" if X86_INTEL_MID
86006c3df49SJamie Iles       select DW_APB_TIMER
861a0c3832aSAlan Cox       depends on X86_INTEL_MID && SFI
862bb24c471SJacob Pan       help
863bb24c471SJacob Pan         APB timer is the replacement for 8254, HPET on X86 MID platforms.
864bb24c471SJacob Pan         The APBT provides a stable time base on SMP
865bb24c471SJacob Pan         systems, unlike the TSC, but it is more expensive to access,
866bb24c471SJacob Pan         as it is off-chip. APB timers are always running regardless of CPU
867bb24c471SJacob Pan         C states, they are used as per CPU clockevent device when possible.
868bb24c471SJacob Pan
8696a108a14SDavid Rientjes# Mark as expert because too many people got it wrong.
870506f1d07SSam Ravnborg# The code disables itself when not needed.
8717ae9392cSThomas Petazzoniconfig DMI
8727ae9392cSThomas Petazzoni	default y
873cf074402SArd Biesheuvel	select DMI_SCAN_MACHINE_NON_EFI_FALLBACK
8746a108a14SDavid Rientjes	bool "Enable DMI scanning" if EXPERT
8758f9ca475SIngo Molnar	---help---
8767ae9392cSThomas Petazzoni	  Enabled scanning of DMI to identify machine quirks. Say Y
8777ae9392cSThomas Petazzoni	  here unless you have verified that your setup is not
8787ae9392cSThomas Petazzoni	  affected by entries in the DMI blacklist. Required by PNP
8797ae9392cSThomas Petazzoni	  BIOS code.
8807ae9392cSThomas Petazzoni
881506f1d07SSam Ravnborgconfig GART_IOMMU
88238901f1cSAndi Kleen	bool "Old AMD GART IOMMU support"
883506f1d07SSam Ravnborg	select SWIOTLB
88423ac4ae8SAndreas Herrmann	depends on X86_64 && PCI && AMD_NB
8858f9ca475SIngo Molnar	---help---
886ced3c42cSIngo Molnar	  Provides a driver for older AMD Athlon64/Opteron/Turion/Sempron
887ced3c42cSIngo Molnar	  GART based hardware IOMMUs.
888ced3c42cSIngo Molnar
889ced3c42cSIngo Molnar	  The GART supports full DMA access for devices with 32-bit access
890ced3c42cSIngo Molnar	  limitations, on systems with more than 3 GB. This is usually needed
891ced3c42cSIngo Molnar	  for USB, sound, many IDE/SATA chipsets and some other devices.
892ced3c42cSIngo Molnar
893ced3c42cSIngo Molnar	  Newer systems typically have a modern AMD IOMMU, supported via
894ced3c42cSIngo Molnar	  the CONFIG_AMD_IOMMU=y config option.
895ced3c42cSIngo Molnar
896ced3c42cSIngo Molnar	  In normal configurations this driver is only active when needed:
897ced3c42cSIngo Molnar	  there's more than 3 GB of memory and the system contains a
898ced3c42cSIngo Molnar	  32-bit limited device.
899ced3c42cSIngo Molnar
900ced3c42cSIngo Molnar	  If unsure, say Y.
901506f1d07SSam Ravnborg
902506f1d07SSam Ravnborgconfig CALGARY_IOMMU
903506f1d07SSam Ravnborg	bool "IBM Calgary IOMMU support"
904506f1d07SSam Ravnborg	select SWIOTLB
9056ea30386SKees Cook	depends on X86_64 && PCI
9068f9ca475SIngo Molnar	---help---
907506f1d07SSam Ravnborg	  Support for hardware IOMMUs in IBM's xSeries x366 and x460
908506f1d07SSam Ravnborg	  systems. Needed to run systems with more than 3GB of memory
909506f1d07SSam Ravnborg	  properly with 32-bit PCI devices that do not support DAC
910506f1d07SSam Ravnborg	  (Double Address Cycle). Calgary also supports bus level
911506f1d07SSam Ravnborg	  isolation, where all DMAs pass through the IOMMU.  This
912506f1d07SSam Ravnborg	  prevents them from going anywhere except their intended
913506f1d07SSam Ravnborg	  destination. This catches hard-to-find kernel bugs and
914506f1d07SSam Ravnborg	  mis-behaving drivers and devices that do not use the DMA-API
915506f1d07SSam Ravnborg	  properly to set up their DMA buffers.  The IOMMU can be
916506f1d07SSam Ravnborg	  turned off at boot time with the iommu=off parameter.
917506f1d07SSam Ravnborg	  Normally the kernel will make the right choice by itself.
918506f1d07SSam Ravnborg	  If unsure, say Y.
919506f1d07SSam Ravnborg
920506f1d07SSam Ravnborgconfig CALGARY_IOMMU_ENABLED_BY_DEFAULT
9213c2362e6SHarvey Harrison	def_bool y
9223c2362e6SHarvey Harrison	prompt "Should Calgary be enabled by default?"
923506f1d07SSam Ravnborg	depends on CALGARY_IOMMU
9248f9ca475SIngo Molnar	---help---
925506f1d07SSam Ravnborg	  Should Calgary be enabled by default? if you choose 'y', Calgary
926506f1d07SSam Ravnborg	  will be used (if it exists). If you choose 'n', Calgary will not be
927506f1d07SSam Ravnborg	  used even if it exists. If you choose 'n' and would like to use
928506f1d07SSam Ravnborg	  Calgary anyway, pass 'iommu=calgary' on the kernel command line.
929506f1d07SSam Ravnborg	  If unsure, say Y.
930506f1d07SSam Ravnborg
931506f1d07SSam Ravnborg# need this always selected by IOMMU for the VIA workaround
932506f1d07SSam Ravnborgconfig SWIOTLB
933a1afd01cSJoerg Roedel	def_bool y if X86_64
9348f9ca475SIngo Molnar	---help---
935506f1d07SSam Ravnborg	  Support for software bounce buffers used on x86-64 systems
9364454d327SJoe Millenbach	  which don't have a hardware IOMMU. Using this PCI devices
9374454d327SJoe Millenbach	  which can only access 32-bits of memory can be used on systems
9384454d327SJoe Millenbach	  with more than 3 GB of memory.
9394454d327SJoe Millenbach	  If unsure, say Y.
940506f1d07SSam Ravnborg
941a8522509SFUJITA Tomonoriconfig IOMMU_HELPER
9423120e25eSJan Beulich	def_bool y
9433120e25eSJan Beulich	depends on CALGARY_IOMMU || GART_IOMMU || SWIOTLB || AMD_IOMMU
944d25e26b6SLinus Torvalds
9451184dc2fSMike Travisconfig MAXSMP
946ddb0c5a6SSamuel Thibault	bool "Enable Maximum number of SMP Processors and NUMA Nodes"
9476ea30386SKees Cook	depends on X86_64 && SMP && DEBUG_KERNEL
94836f5101aSMike Travis	select CPUMASK_OFFSTACK
9498f9ca475SIngo Molnar	---help---
950ddb0c5a6SSamuel Thibault	  Enable maximum number of CPUS and NUMA Nodes for this architecture.
9511184dc2fSMike Travis	  If unsure, say N.
952506f1d07SSam Ravnborg
953506f1d07SSam Ravnborgconfig NR_CPUS
95436f5101aSMike Travis	int "Maximum number of CPUs" if SMP && !MAXSMP
9552a3313f4SMichael K. Johnson	range 2 8 if SMP && X86_32 && !X86_BIGSMP
9567bbcbd3dSThomas Gleixner	range 2 64 if SMP && X86_32 && X86_BIGSMP
9577bbcbd3dSThomas Gleixner	range 2 512 if SMP && !MAXSMP && !CPUMASK_OFFSTACK && X86_64
958b53b5edaSJosh Boyer	range 2 8192 if SMP && !MAXSMP && CPUMASK_OFFSTACK && X86_64
95978637a97SMike Travis	default "1" if !SMP
960b53b5edaSJosh Boyer	default "8192" if MAXSMP
961b5660ba7SH. Peter Anvin	default "32" if SMP && X86_BIGSMP
962c5c19941SKirill A. Shutemov	default "8" if SMP && X86_32
963c5c19941SKirill A. Shutemov	default "64" if SMP
9648f9ca475SIngo Molnar	---help---
965506f1d07SSam Ravnborg	  This allows you to specify the maximum number of CPUs which this
966bb61ccc7SJosh Boyer	  kernel will support.  If CPUMASK_OFFSTACK is enabled, the maximum
967cad14bb9SKirill A. Shutemov	  supported value is 8192, otherwise the maximum value is 512.  The
968506f1d07SSam Ravnborg	  minimum value which makes sense is 2.
969506f1d07SSam Ravnborg
970506f1d07SSam Ravnborg	  This is purely to save memory - each supported CPU adds
971506f1d07SSam Ravnborg	  approximately eight kilobytes to the kernel image.
972506f1d07SSam Ravnborg
973506f1d07SSam Ravnborgconfig SCHED_SMT
974506f1d07SSam Ravnborg	bool "SMT (Hyperthreading) scheduler support"
975c8e56d20SBorislav Petkov	depends on SMP
9768f9ca475SIngo Molnar	---help---
977506f1d07SSam Ravnborg	  SMT scheduler support improves the CPU scheduler's decision making
978506f1d07SSam Ravnborg	  when dealing with Intel Pentium 4 chips with HyperThreading at a
979506f1d07SSam Ravnborg	  cost of slightly increased overhead in some places. If unsure say
980506f1d07SSam Ravnborg	  N here.
981506f1d07SSam Ravnborg
982506f1d07SSam Ravnborgconfig SCHED_MC
9833c2362e6SHarvey Harrison	def_bool y
9843c2362e6SHarvey Harrison	prompt "Multi-core scheduler support"
985c8e56d20SBorislav Petkov	depends on SMP
9868f9ca475SIngo Molnar	---help---
987506f1d07SSam Ravnborg	  Multi-core scheduler support improves the CPU scheduler's decision
988506f1d07SSam Ravnborg	  making when dealing with multi-core CPU chips at a cost of slightly
989506f1d07SSam Ravnborg	  increased overhead in some places. If unsure say N here.
990506f1d07SSam Ravnborg
991de966cf4STim Chenconfig SCHED_MC_PRIO
992de966cf4STim Chen	bool "CPU core priorities scheduler support"
9930a21fc12SIngo Molnar	depends on SCHED_MC && CPU_SUP_INTEL
9940a21fc12SIngo Molnar	select X86_INTEL_PSTATE
9950a21fc12SIngo Molnar	select CPU_FREQ
996de966cf4STim Chen	default y
9975e76b2abSTim Chen	---help---
998de966cf4STim Chen	  Intel Turbo Boost Max Technology 3.0 enabled CPUs have a
999de966cf4STim Chen	  core ordering determined at manufacturing time, which allows
1000de966cf4STim Chen	  certain cores to reach higher turbo frequencies (when running
1001de966cf4STim Chen	  single threaded workloads) than others.
1002de966cf4STim Chen
1003de966cf4STim Chen	  Enabling this kernel feature teaches the scheduler about
1004de966cf4STim Chen	  the TBM3 (aka ITMT) priority order of the CPU cores and adjusts the
1005de966cf4STim Chen	  scheduler's CPU selection logic accordingly, so that higher
1006de966cf4STim Chen	  overall system performance can be achieved.
1007de966cf4STim Chen
1008de966cf4STim Chen	  This feature will have no effect on CPUs without this feature.
1009de966cf4STim Chen
1010de966cf4STim Chen	  If unsure say Y here.
10115e76b2abSTim Chen
1012506f1d07SSam Ravnborgsource "kernel/Kconfig.preempt"
1013506f1d07SSam Ravnborg
101430b8b006SThomas Gleixnerconfig UP_LATE_INIT
101530b8b006SThomas Gleixner       def_bool y
1016ba360f88SThomas Gleixner       depends on !SMP && X86_LOCAL_APIC
101730b8b006SThomas Gleixner
1018506f1d07SSam Ravnborgconfig X86_UP_APIC
101950849eefSJan Beulich	bool "Local APIC support on uniprocessors" if !PCI_MSI
102050849eefSJan Beulich	default PCI_MSI
102138a1dfdaSBryan O'Donoghue	depends on X86_32 && !SMP && !X86_32_NON_STANDARD
10228f9ca475SIngo Molnar	---help---
1023506f1d07SSam Ravnborg	  A local APIC (Advanced Programmable Interrupt Controller) is an
1024506f1d07SSam Ravnborg	  integrated interrupt controller in the CPU. If you have a single-CPU
1025506f1d07SSam Ravnborg	  system which has a processor with a local APIC, you can say Y here to
1026506f1d07SSam Ravnborg	  enable and use it. If you say Y here even though your machine doesn't
1027506f1d07SSam Ravnborg	  have a local APIC, then the kernel will still run with no slowdown at
1028506f1d07SSam Ravnborg	  all. The local APIC supports CPU-generated self-interrupts (timer,
1029506f1d07SSam Ravnborg	  performance counters), and the NMI watchdog which detects hard
1030506f1d07SSam Ravnborg	  lockups.
1031506f1d07SSam Ravnborg
1032506f1d07SSam Ravnborgconfig X86_UP_IOAPIC
1033506f1d07SSam Ravnborg	bool "IO-APIC support on uniprocessors"
1034506f1d07SSam Ravnborg	depends on X86_UP_APIC
10358f9ca475SIngo Molnar	---help---
1036506f1d07SSam Ravnborg	  An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an
1037506f1d07SSam Ravnborg	  SMP-capable replacement for PC-style interrupt controllers. Most
1038506f1d07SSam Ravnborg	  SMP systems and many recent uniprocessor systems have one.
1039506f1d07SSam Ravnborg
1040506f1d07SSam Ravnborg	  If you have a single-CPU system with an IO-APIC, you can say Y here
1041506f1d07SSam Ravnborg	  to use it. If you say Y here even though your machine doesn't have
1042506f1d07SSam Ravnborg	  an IO-APIC, then the kernel will still run with no slowdown at all.
1043506f1d07SSam Ravnborg
1044506f1d07SSam Ravnborgconfig X86_LOCAL_APIC
10453c2362e6SHarvey Harrison	def_bool y
10460dbc6078SThomas Petazzoni	depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC || PCI_MSI
1047b5dc8e6cSJiang Liu	select IRQ_DOMAIN_HIERARCHY
104852f518a3SJiang Liu	select PCI_MSI_IRQ_DOMAIN if PCI_MSI
1049506f1d07SSam Ravnborg
1050506f1d07SSam Ravnborgconfig X86_IO_APIC
1051b1da1e71SJan Beulich	def_bool y
1052b1da1e71SJan Beulich	depends on X86_LOCAL_APIC || X86_UP_IOAPIC
1053506f1d07SSam Ravnborg
105441b9eb26SStefan Assmannconfig X86_REROUTE_FOR_BROKEN_BOOT_IRQS
105541b9eb26SStefan Assmann	bool "Reroute for broken boot IRQs"
105641b9eb26SStefan Assmann	depends on X86_IO_APIC
10578f9ca475SIngo Molnar	---help---
105841b9eb26SStefan Assmann	  This option enables a workaround that fixes a source of
105941b9eb26SStefan Assmann	  spurious interrupts. This is recommended when threaded
106041b9eb26SStefan Assmann	  interrupt handling is used on systems where the generation of
106141b9eb26SStefan Assmann	  superfluous "boot interrupts" cannot be disabled.
106241b9eb26SStefan Assmann
106341b9eb26SStefan Assmann	  Some chipsets generate a legacy INTx "boot IRQ" when the IRQ
106441b9eb26SStefan Assmann	  entry in the chipset's IO-APIC is masked (as, e.g. the RT
106541b9eb26SStefan Assmann	  kernel does during interrupt handling). On chipsets where this
106641b9eb26SStefan Assmann	  boot IRQ generation cannot be disabled, this workaround keeps
106741b9eb26SStefan Assmann	  the original IRQ line masked so that only the equivalent "boot
106841b9eb26SStefan Assmann	  IRQ" is delivered to the CPUs. The workaround also tells the
106941b9eb26SStefan Assmann	  kernel to set up the IRQ handler on the boot IRQ line. In this
107041b9eb26SStefan Assmann	  way only one interrupt is delivered to the kernel. Otherwise
107141b9eb26SStefan Assmann	  the spurious second interrupt may cause the kernel to bring
107241b9eb26SStefan Assmann	  down (vital) interrupt lines.
107341b9eb26SStefan Assmann
107441b9eb26SStefan Assmann	  Only affects "broken" chipsets. Interrupt sharing may be
107541b9eb26SStefan Assmann	  increased on these systems.
107641b9eb26SStefan Assmann
1077506f1d07SSam Ravnborgconfig X86_MCE
1078bab9bc65SAndi Kleen	bool "Machine Check / overheating reporting"
1079648ed940SChen, Gong	select GENERIC_ALLOCATOR
1080e57dbaf7SBorislav Petkov	default y
1081506f1d07SSam Ravnborg	---help---
1082bab9bc65SAndi Kleen	  Machine Check support allows the processor to notify the
1083bab9bc65SAndi Kleen	  kernel if it detects a problem (e.g. overheating, data corruption).
1084506f1d07SSam Ravnborg	  The action the kernel takes depends on the severity of the problem,
1085bab9bc65SAndi Kleen	  ranging from warning messages to halting the machine.
10864efc0670SAndi Kleen
10875de97c9fSTony Luckconfig X86_MCELOG_LEGACY
10885de97c9fSTony Luck	bool "Support for deprecated /dev/mcelog character device"
10895de97c9fSTony Luck	depends on X86_MCE
10905de97c9fSTony Luck	---help---
10915de97c9fSTony Luck	  Enable support for /dev/mcelog which is needed by the old mcelog
10925de97c9fSTony Luck	  userspace logging daemon. Consider switching to the new generation
10935de97c9fSTony Luck	  rasdaemon solution.
10945de97c9fSTony Luck
1095506f1d07SSam Ravnborgconfig X86_MCE_INTEL
10963c2362e6SHarvey Harrison	def_bool y
10973c2362e6SHarvey Harrison	prompt "Intel MCE features"
1098c1ebf835SAndi Kleen	depends on X86_MCE && X86_LOCAL_APIC
10998f9ca475SIngo Molnar	---help---
1100506f1d07SSam Ravnborg	   Additional support for intel specific MCE features such as
1101506f1d07SSam Ravnborg	   the thermal monitor.
1102506f1d07SSam Ravnborg
1103506f1d07SSam Ravnborgconfig X86_MCE_AMD
11043c2362e6SHarvey Harrison	def_bool y
11053c2362e6SHarvey Harrison	prompt "AMD MCE features"
1106f5382de9SYazen Ghannam	depends on X86_MCE && X86_LOCAL_APIC && AMD_NB
11078f9ca475SIngo Molnar	---help---
1108506f1d07SSam Ravnborg	   Additional support for AMD specific MCE features such as
1109506f1d07SSam Ravnborg	   the DRAM Error Threshold.
1110506f1d07SSam Ravnborg
11114efc0670SAndi Kleenconfig X86_ANCIENT_MCE
11126fc108a0SJan Beulich	bool "Support for old Pentium 5 / WinChip machine checks"
1113c31d9633SAndi Kleen	depends on X86_32 && X86_MCE
11144efc0670SAndi Kleen	---help---
11154efc0670SAndi Kleen	  Include support for machine check handling on old Pentium 5 or WinChip
11165065a706SMasanari Iida	  systems. These typically need to be enabled explicitly on the command
11174efc0670SAndi Kleen	  line.
11184efc0670SAndi Kleen
1119b2762686SAndi Kleenconfig X86_MCE_THRESHOLD
1120b2762686SAndi Kleen	depends on X86_MCE_AMD || X86_MCE_INTEL
11216fc108a0SJan Beulich	def_bool y
1122b2762686SAndi Kleen
1123ea149b36SAndi Kleenconfig X86_MCE_INJECT
1124bc8e80d5SBorislav Petkov	depends on X86_MCE && X86_LOCAL_APIC && DEBUG_FS
1125ea149b36SAndi Kleen	tristate "Machine check injector support"
1126ea149b36SAndi Kleen	---help---
1127ea149b36SAndi Kleen	  Provide support for injecting machine checks for testing purposes.
1128ea149b36SAndi Kleen	  If you don't know what a machine check is and you don't do kernel
1129ea149b36SAndi Kleen	  QA it is safe to say n.
1130ea149b36SAndi Kleen
11314efc0670SAndi Kleenconfig X86_THERMAL_VECTOR
11324efc0670SAndi Kleen	def_bool y
11335bb38adcSAndi Kleen	depends on X86_MCE_INTEL
11344efc0670SAndi Kleen
113507dc900eSPeter Zijlstrasource "arch/x86/events/Kconfig"
1136e633c65aSKan Liang
11375aef51c3SAndy Lutomirskiconfig X86_LEGACY_VM86
11381e642812SIngo Molnar	bool "Legacy VM86 support"
11395aef51c3SAndy Lutomirski	default n
1140506f1d07SSam Ravnborg	depends on X86_32
11418f9ca475SIngo Molnar	---help---
11425aef51c3SAndy Lutomirski	  This option allows user programs to put the CPU into V8086
11435aef51c3SAndy Lutomirski	  mode, which is an 80286-era approximation of 16-bit real mode.
11445aef51c3SAndy Lutomirski
11455aef51c3SAndy Lutomirski	  Some very old versions of X and/or vbetool require this option
11465aef51c3SAndy Lutomirski	  for user mode setting.  Similarly, DOSEMU will use it if
11475aef51c3SAndy Lutomirski	  available to accelerate real mode DOS programs.  However, any
11485aef51c3SAndy Lutomirski	  recent version of DOSEMU, X, or vbetool should be fully
11495aef51c3SAndy Lutomirski	  functional even without kernel VM86 support, as they will all
11501e642812SIngo Molnar	  fall back to software emulation. Nevertheless, if you are using
11511e642812SIngo Molnar	  a 16-bit DOS program where 16-bit performance matters, vm86
11521e642812SIngo Molnar	  mode might be faster than emulation and you might want to
11531e642812SIngo Molnar	  enable this option.
11545aef51c3SAndy Lutomirski
11551e642812SIngo Molnar	  Note that any app that works on a 64-bit kernel is unlikely to
11561e642812SIngo Molnar	  need this option, as 64-bit kernels don't, and can't, support
11571e642812SIngo Molnar	  V8086 mode. This option is also unrelated to 16-bit protected
11581e642812SIngo Molnar	  mode and is not needed to run most 16-bit programs under Wine.
11595aef51c3SAndy Lutomirski
11601e642812SIngo Molnar	  Enabling this option increases the complexity of the kernel
11611e642812SIngo Molnar	  and slows down exception handling a tiny bit.
11625aef51c3SAndy Lutomirski
11631e642812SIngo Molnar	  If unsure, say N here.
11645aef51c3SAndy Lutomirski
11655aef51c3SAndy Lutomirskiconfig VM86
11665aef51c3SAndy Lutomirski       bool
11675aef51c3SAndy Lutomirski       default X86_LEGACY_VM86
116834273f41SH. Peter Anvin
116934273f41SH. Peter Anvinconfig X86_16BIT
117034273f41SH. Peter Anvin	bool "Enable support for 16-bit segments" if EXPERT
117134273f41SH. Peter Anvin	default y
1172a5b9e5a2SAndy Lutomirski	depends on MODIFY_LDT_SYSCALL
117334273f41SH. Peter Anvin	---help---
117434273f41SH. Peter Anvin	  This option is required by programs like Wine to run 16-bit
117534273f41SH. Peter Anvin	  protected mode legacy code on x86 processors.  Disabling
117634273f41SH. Peter Anvin	  this option saves about 300 bytes on i386, or around 6K text
117734273f41SH. Peter Anvin	  plus 16K runtime memory on x86-64,
117834273f41SH. Peter Anvin
117934273f41SH. Peter Anvinconfig X86_ESPFIX32
118034273f41SH. Peter Anvin	def_bool y
118134273f41SH. Peter Anvin	depends on X86_16BIT && X86_32
1182506f1d07SSam Ravnborg
1183197725deSH. Peter Anvinconfig X86_ESPFIX64
1184197725deSH. Peter Anvin	def_bool y
118534273f41SH. Peter Anvin	depends on X86_16BIT && X86_64
1186506f1d07SSam Ravnborg
11871ad83c85SAndy Lutomirskiconfig X86_VSYSCALL_EMULATION
11881ad83c85SAndy Lutomirski       bool "Enable vsyscall emulation" if EXPERT
11891ad83c85SAndy Lutomirski       default y
11901ad83c85SAndy Lutomirski       depends on X86_64
11911ad83c85SAndy Lutomirski       ---help---
11921ad83c85SAndy Lutomirski	 This enables emulation of the legacy vsyscall page.  Disabling
11931ad83c85SAndy Lutomirski	 it is roughly equivalent to booting with vsyscall=none, except
11941ad83c85SAndy Lutomirski	 that it will also disable the helpful warning if a program
11951ad83c85SAndy Lutomirski	 tries to use a vsyscall.  With this option set to N, offending
11961ad83c85SAndy Lutomirski	 programs will just segfault, citing addresses of the form
11971ad83c85SAndy Lutomirski	 0xffffffffff600?00.
11981ad83c85SAndy Lutomirski
11991ad83c85SAndy Lutomirski	 This option is required by many programs built before 2013, and
12001ad83c85SAndy Lutomirski	 care should be used even with newer programs if set to N.
12011ad83c85SAndy Lutomirski
12021ad83c85SAndy Lutomirski	 Disabling this option saves about 7K of kernel size and
12031ad83c85SAndy Lutomirski	 possibly 4K of additional runtime pagetable memory.
12041ad83c85SAndy Lutomirski
1205506f1d07SSam Ravnborgconfig TOSHIBA
1206506f1d07SSam Ravnborg	tristate "Toshiba Laptop support"
1207506f1d07SSam Ravnborg	depends on X86_32
1208506f1d07SSam Ravnborg	---help---
1209506f1d07SSam Ravnborg	  This adds a driver to safely access the System Management Mode of
1210506f1d07SSam Ravnborg	  the CPU on Toshiba portables with a genuine Toshiba BIOS. It does
1211506f1d07SSam Ravnborg	  not work on models with a Phoenix BIOS. The System Management Mode
1212506f1d07SSam Ravnborg	  is used to set the BIOS and power saving options on Toshiba portables.
1213506f1d07SSam Ravnborg
1214506f1d07SSam Ravnborg	  For information on utilities to make use of this driver see the
1215506f1d07SSam Ravnborg	  Toshiba Linux utilities web site at:
1216506f1d07SSam Ravnborg	  <http://www.buzzard.org.uk/toshiba/>.
1217506f1d07SSam Ravnborg
1218506f1d07SSam Ravnborg	  Say Y if you intend to run this kernel on a Toshiba portable.
1219506f1d07SSam Ravnborg	  Say N otherwise.
1220506f1d07SSam Ravnborg
1221506f1d07SSam Ravnborgconfig I8K
1222039ae585SPali Rohár	tristate "Dell i8k legacy laptop support"
1223949a9d70SJean Delvare	select HWMON
1224039ae585SPali Rohár	select SENSORS_DELL_SMM
1225506f1d07SSam Ravnborg	---help---
1226039ae585SPali Rohár	  This option enables legacy /proc/i8k userspace interface in hwmon
1227039ae585SPali Rohár	  dell-smm-hwmon driver. Character file /proc/i8k reports bios version,
1228039ae585SPali Rohár	  temperature and allows controlling fan speeds of Dell laptops via
1229039ae585SPali Rohár	  System Management Mode. For old Dell laptops (like Dell Inspiron 8000)
1230039ae585SPali Rohár	  it reports also power and hotkey status. For fan speed control is
1231039ae585SPali Rohár	  needed userspace package i8kutils.
1232506f1d07SSam Ravnborg
1233039ae585SPali Rohár	  Say Y if you intend to run this kernel on old Dell laptops or want to
1234039ae585SPali Rohár	  use userspace package i8kutils.
1235506f1d07SSam Ravnborg	  Say N otherwise.
1236506f1d07SSam Ravnborg
1237506f1d07SSam Ravnborgconfig X86_REBOOTFIXUPS
12389ba16087SJan Beulich	bool "Enable X86 board specific fixups for reboot"
12399ba16087SJan Beulich	depends on X86_32
1240506f1d07SSam Ravnborg	---help---
1241506f1d07SSam Ravnborg	  This enables chipset and/or board specific fixups to be done
1242506f1d07SSam Ravnborg	  in order to get reboot to work correctly. This is only needed on
1243506f1d07SSam Ravnborg	  some combinations of hardware and BIOS. The symptom, for which
1244506f1d07SSam Ravnborg	  this config is intended, is when reboot ends with a stalled/hung
1245506f1d07SSam Ravnborg	  system.
1246506f1d07SSam Ravnborg
1247506f1d07SSam Ravnborg	  Currently, the only fixup is for the Geode machines using
12485e3a77e9SFlorian Fainelli	  CS5530A and CS5536 chipsets and the RDC R-321x SoC.
1249506f1d07SSam Ravnborg
1250506f1d07SSam Ravnborg	  Say Y if you want to enable the fixup. Currently, it's safe to
1251506f1d07SSam Ravnborg	  enable this option even if you don't need it.
1252506f1d07SSam Ravnborg	  Say N otherwise.
1253506f1d07SSam Ravnborg
1254506f1d07SSam Ravnborgconfig MICROCODE
12559a2bc335SBorislav Petkov	bool "CPU microcode loading support"
12569a2bc335SBorislav Petkov	default y
125780030e3dSBorislav Petkov	depends on CPU_SUP_AMD || CPU_SUP_INTEL
1258506f1d07SSam Ravnborg	select FW_LOADER
1259506f1d07SSam Ravnborg	---help---
1260506f1d07SSam Ravnborg	  If you say Y here, you will be able to update the microcode on
12615f9c01aaSBorislav Petkov	  Intel and AMD processors. The Intel support is for the IA32 family,
12625f9c01aaSBorislav Petkov	  e.g. Pentium Pro, Pentium II, Pentium III, Pentium 4, Xeon etc. The
12635f9c01aaSBorislav Petkov	  AMD support is for families 0x10 and later. You will obviously need
12645f9c01aaSBorislav Petkov	  the actual microcode binary data itself which is not shipped with
12655f9c01aaSBorislav Petkov	  the Linux kernel.
1266506f1d07SSam Ravnborg
12675f9c01aaSBorislav Petkov	  The preferred method to load microcode from a detached initrd is described
12685f9c01aaSBorislav Petkov	  in Documentation/x86/early-microcode.txt. For that you need to enable
12695f9c01aaSBorislav Petkov	  CONFIG_BLK_DEV_INITRD in order for the loader to be able to scan the
12705f9c01aaSBorislav Petkov	  initrd for microcode blobs.
1271506f1d07SSam Ravnborg
1272c508c46eSBenjamin Gilbert	  In addition, you can build the microcode into the kernel. For that you
1273c508c46eSBenjamin Gilbert	  need to add the vendor-supplied microcode to the CONFIG_EXTRA_FIRMWARE
1274c508c46eSBenjamin Gilbert	  config option.
1275506f1d07SSam Ravnborg
12768d86f390SPeter Orubaconfig MICROCODE_INTEL
1277e43f6e67SBorislav Petkov	bool "Intel microcode loading support"
12788d86f390SPeter Oruba	depends on MICROCODE
12798d86f390SPeter Oruba	default MICROCODE
12808d86f390SPeter Oruba	select FW_LOADER
12818f9ca475SIngo Molnar	---help---
12828d86f390SPeter Oruba	  This options enables microcode patch loading support for Intel
12838d86f390SPeter Oruba	  processors.
12848d86f390SPeter Oruba
1285b8989db9SAlan	  For the current Intel microcode data package go to
1286b8989db9SAlan	  <https://downloadcenter.intel.com> and search for
1287b8989db9SAlan	  'Linux Processor Microcode Data File'.
12888d86f390SPeter Oruba
128980cc9f10SPeter Orubaconfig MICROCODE_AMD
1290e43f6e67SBorislav Petkov	bool "AMD microcode loading support"
129180cc9f10SPeter Oruba	depends on MICROCODE
129280cc9f10SPeter Oruba	select FW_LOADER
12938f9ca475SIngo Molnar	---help---
129480cc9f10SPeter Oruba	  If you select this option, microcode patch loading support for AMD
129580cc9f10SPeter Oruba	  processors will be enabled.
129680cc9f10SPeter Oruba
1297506f1d07SSam Ravnborgconfig MICROCODE_OLD_INTERFACE
12983c2362e6SHarvey Harrison	def_bool y
1299506f1d07SSam Ravnborg	depends on MICROCODE
1300506f1d07SSam Ravnborg
1301506f1d07SSam Ravnborgconfig X86_MSR
1302506f1d07SSam Ravnborg	tristate "/dev/cpu/*/msr - Model-specific register support"
13038f9ca475SIngo Molnar	---help---
1304506f1d07SSam Ravnborg	  This device gives privileged processes access to the x86
1305506f1d07SSam Ravnborg	  Model-Specific Registers (MSRs).  It is a character device with
1306506f1d07SSam Ravnborg	  major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr.
1307506f1d07SSam Ravnborg	  MSR accesses are directed to a specific CPU on multi-processor
1308506f1d07SSam Ravnborg	  systems.
1309506f1d07SSam Ravnborg
1310506f1d07SSam Ravnborgconfig X86_CPUID
1311506f1d07SSam Ravnborg	tristate "/dev/cpu/*/cpuid - CPU information support"
13128f9ca475SIngo Molnar	---help---
1313506f1d07SSam Ravnborg	  This device gives processes access to the x86 CPUID instruction to
1314506f1d07SSam Ravnborg	  be executed on a specific processor.  It is a character device
1315506f1d07SSam Ravnborg	  with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to
1316506f1d07SSam Ravnborg	  /dev/cpu/31/cpuid.
1317506f1d07SSam Ravnborg
1318506f1d07SSam Ravnborgchoice
1319506f1d07SSam Ravnborg	prompt "High Memory Support"
13206fc108a0SJan Beulich	default HIGHMEM4G
1321506f1d07SSam Ravnborg	depends on X86_32
1322506f1d07SSam Ravnborg
1323506f1d07SSam Ravnborgconfig NOHIGHMEM
1324506f1d07SSam Ravnborg	bool "off"
1325506f1d07SSam Ravnborg	---help---
1326506f1d07SSam Ravnborg	  Linux can use up to 64 Gigabytes of physical memory on x86 systems.
1327506f1d07SSam Ravnborg	  However, the address space of 32-bit x86 processors is only 4
1328506f1d07SSam Ravnborg	  Gigabytes large. That means that, if you have a large amount of
1329506f1d07SSam Ravnborg	  physical memory, not all of it can be "permanently mapped" by the
1330506f1d07SSam Ravnborg	  kernel. The physical memory that's not permanently mapped is called
1331506f1d07SSam Ravnborg	  "high memory".
1332506f1d07SSam Ravnborg
1333506f1d07SSam Ravnborg	  If you are compiling a kernel which will never run on a machine with
1334506f1d07SSam Ravnborg	  more than 1 Gigabyte total physical RAM, answer "off" here (default
1335506f1d07SSam Ravnborg	  choice and suitable for most users). This will result in a "3GB/1GB"
1336506f1d07SSam Ravnborg	  split: 3GB are mapped so that each process sees a 3GB virtual memory
1337506f1d07SSam Ravnborg	  space and the remaining part of the 4GB virtual memory space is used
1338506f1d07SSam Ravnborg	  by the kernel to permanently map as much physical memory as
1339506f1d07SSam Ravnborg	  possible.
1340506f1d07SSam Ravnborg
1341506f1d07SSam Ravnborg	  If the machine has between 1 and 4 Gigabytes physical RAM, then
1342506f1d07SSam Ravnborg	  answer "4GB" here.
1343506f1d07SSam Ravnborg
1344506f1d07SSam Ravnborg	  If more than 4 Gigabytes is used then answer "64GB" here. This
1345506f1d07SSam Ravnborg	  selection turns Intel PAE (Physical Address Extension) mode on.
1346506f1d07SSam Ravnborg	  PAE implements 3-level paging on IA32 processors. PAE is fully
1347506f1d07SSam Ravnborg	  supported by Linux, PAE mode is implemented on all recent Intel
1348506f1d07SSam Ravnborg	  processors (Pentium Pro and better). NOTE: If you say "64GB" here,
1349506f1d07SSam Ravnborg	  then the kernel will not boot on CPUs that don't support PAE!
1350506f1d07SSam Ravnborg
1351506f1d07SSam Ravnborg	  The actual amount of total physical memory will either be
1352506f1d07SSam Ravnborg	  auto detected or can be forced by using a kernel command line option
1353506f1d07SSam Ravnborg	  such as "mem=256M". (Try "man bootparam" or see the documentation of
1354506f1d07SSam Ravnborg	  your boot loader (lilo or loadlin) about how to pass options to the
1355506f1d07SSam Ravnborg	  kernel at boot time.)
1356506f1d07SSam Ravnborg
1357506f1d07SSam Ravnborg	  If unsure, say "off".
1358506f1d07SSam Ravnborg
1359506f1d07SSam Ravnborgconfig HIGHMEM4G
1360506f1d07SSam Ravnborg	bool "4GB"
13618f9ca475SIngo Molnar	---help---
1362506f1d07SSam Ravnborg	  Select this if you have a 32-bit processor and between 1 and 4
1363506f1d07SSam Ravnborg	  gigabytes of physical RAM.
1364506f1d07SSam Ravnborg
1365506f1d07SSam Ravnborgconfig HIGHMEM64G
1366506f1d07SSam Ravnborg	bool "64GB"
1367eb068e78SH. Peter Anvin	depends on !M486
1368506f1d07SSam Ravnborg	select X86_PAE
13698f9ca475SIngo Molnar	---help---
1370506f1d07SSam Ravnborg	  Select this if you have a 32-bit processor and more than 4
1371506f1d07SSam Ravnborg	  gigabytes of physical RAM.
1372506f1d07SSam Ravnborg
1373506f1d07SSam Ravnborgendchoice
1374506f1d07SSam Ravnborg
1375506f1d07SSam Ravnborgchoice
13766a108a14SDavid Rientjes	prompt "Memory split" if EXPERT
1377506f1d07SSam Ravnborg	default VMSPLIT_3G
1378506f1d07SSam Ravnborg	depends on X86_32
13798f9ca475SIngo Molnar	---help---
1380506f1d07SSam Ravnborg	  Select the desired split between kernel and user memory.
1381506f1d07SSam Ravnborg
1382506f1d07SSam Ravnborg	  If the address range available to the kernel is less than the
1383506f1d07SSam Ravnborg	  physical memory installed, the remaining memory will be available
1384506f1d07SSam Ravnborg	  as "high memory". Accessing high memory is a little more costly
1385506f1d07SSam Ravnborg	  than low memory, as it needs to be mapped into the kernel first.
1386506f1d07SSam Ravnborg	  Note that increasing the kernel address space limits the range
1387506f1d07SSam Ravnborg	  available to user programs, making the address space there
1388506f1d07SSam Ravnborg	  tighter.  Selecting anything other than the default 3G/1G split
1389506f1d07SSam Ravnborg	  will also likely make your kernel incompatible with binary-only
1390506f1d07SSam Ravnborg	  kernel modules.
1391506f1d07SSam Ravnborg
1392506f1d07SSam Ravnborg	  If you are not absolutely sure what you are doing, leave this
1393506f1d07SSam Ravnborg	  option alone!
1394506f1d07SSam Ravnborg
1395506f1d07SSam Ravnborg	config VMSPLIT_3G
1396506f1d07SSam Ravnborg		bool "3G/1G user/kernel split"
1397506f1d07SSam Ravnborg	config VMSPLIT_3G_OPT
1398506f1d07SSam Ravnborg		depends on !X86_PAE
1399506f1d07SSam Ravnborg		bool "3G/1G user/kernel split (for full 1G low memory)"
1400506f1d07SSam Ravnborg	config VMSPLIT_2G
1401506f1d07SSam Ravnborg		bool "2G/2G user/kernel split"
1402506f1d07SSam Ravnborg	config VMSPLIT_2G_OPT
1403506f1d07SSam Ravnborg		depends on !X86_PAE
1404506f1d07SSam Ravnborg		bool "2G/2G user/kernel split (for full 2G low memory)"
1405506f1d07SSam Ravnborg	config VMSPLIT_1G
1406506f1d07SSam Ravnborg		bool "1G/3G user/kernel split"
1407506f1d07SSam Ravnborgendchoice
1408506f1d07SSam Ravnborg
1409506f1d07SSam Ravnborgconfig PAGE_OFFSET
1410506f1d07SSam Ravnborg	hex
1411506f1d07SSam Ravnborg	default 0xB0000000 if VMSPLIT_3G_OPT
1412506f1d07SSam Ravnborg	default 0x80000000 if VMSPLIT_2G
1413506f1d07SSam Ravnborg	default 0x78000000 if VMSPLIT_2G_OPT
1414506f1d07SSam Ravnborg	default 0x40000000 if VMSPLIT_1G
1415506f1d07SSam Ravnborg	default 0xC0000000
1416506f1d07SSam Ravnborg	depends on X86_32
1417506f1d07SSam Ravnborg
1418506f1d07SSam Ravnborgconfig HIGHMEM
14193c2362e6SHarvey Harrison	def_bool y
1420506f1d07SSam Ravnborg	depends on X86_32 && (HIGHMEM64G || HIGHMEM4G)
1421506f1d07SSam Ravnborg
1422506f1d07SSam Ravnborgconfig X86_PAE
14239ba16087SJan Beulich	bool "PAE (Physical Address Extension) Support"
1424506f1d07SSam Ravnborg	depends on X86_32 && !HIGHMEM4G
14259d99c712SChristian Melki	select SWIOTLB
14268f9ca475SIngo Molnar	---help---
1427506f1d07SSam Ravnborg	  PAE is required for NX support, and furthermore enables
1428506f1d07SSam Ravnborg	  larger swapspace support for non-overcommit purposes. It
1429506f1d07SSam Ravnborg	  has the cost of more pagetable lookup overhead, and also
1430506f1d07SSam Ravnborg	  consumes more pagetable space per process.
1431506f1d07SSam Ravnborg
143277ef56e4SKirill A. Shutemovconfig X86_5LEVEL
143377ef56e4SKirill A. Shutemov	bool "Enable 5-level page tables support"
143477ef56e4SKirill A. Shutemov	depends on X86_64
143577ef56e4SKirill A. Shutemov	---help---
143677ef56e4SKirill A. Shutemov	  5-level paging enables access to larger address space:
143777ef56e4SKirill A. Shutemov	  upto 128 PiB of virtual address space and 4 PiB of
143877ef56e4SKirill A. Shutemov	  physical address space.
143977ef56e4SKirill A. Shutemov
144077ef56e4SKirill A. Shutemov	  It will be supported by future Intel CPUs.
144177ef56e4SKirill A. Shutemov
144277ef56e4SKirill A. Shutemov	  Note: a kernel with this option enabled can only be booted
144377ef56e4SKirill A. Shutemov	  on machines that support the feature.
144477ef56e4SKirill A. Shutemov
144577ef56e4SKirill A. Shutemov	  See Documentation/x86/x86_64/5level-paging.txt for more
144677ef56e4SKirill A. Shutemov	  information.
144777ef56e4SKirill A. Shutemov
144877ef56e4SKirill A. Shutemov	  Say N if unsure.
144977ef56e4SKirill A. Shutemov
1450600715dcSJeremy Fitzhardingeconfig ARCH_PHYS_ADDR_T_64BIT
14513120e25eSJan Beulich	def_bool y
14523120e25eSJan Beulich	depends on X86_64 || X86_PAE
1453600715dcSJeremy Fitzhardinge
145466f2b061SFUJITA Tomonoriconfig ARCH_DMA_ADDR_T_64BIT
14553120e25eSJan Beulich	def_bool y
14563120e25eSJan Beulich	depends on X86_64 || HIGHMEM64G
145766f2b061SFUJITA Tomonori
145810971ab2SIngo Molnarconfig X86_DIRECT_GBPAGES
1459e5008abeSLuis R. Rodriguez	def_bool y
14604675ff05SLevin, Alexander (Sasha Levin)	depends on X86_64 && !DEBUG_PAGEALLOC
14618f9ca475SIngo Molnar	---help---
146210971ab2SIngo Molnar	  Certain kernel features effectively disable kernel
146310971ab2SIngo Molnar	  linear 1 GB mappings (even if the CPU otherwise
146410971ab2SIngo Molnar	  supports them), so don't confuse the user by printing
146510971ab2SIngo Molnar	  that we have them enabled.
14669e899816SNick Piggin
14677744ccdbSTom Lendackyconfig ARCH_HAS_MEM_ENCRYPT
14687744ccdbSTom Lendacky	def_bool y
14697744ccdbSTom Lendacky
14707744ccdbSTom Lendackyconfig AMD_MEM_ENCRYPT
14717744ccdbSTom Lendacky	bool "AMD Secure Memory Encryption (SME) support"
14727744ccdbSTom Lendacky	depends on X86_64 && CPU_SUP_AMD
14737744ccdbSTom Lendacky	---help---
14747744ccdbSTom Lendacky	  Say yes to enable support for the encryption of system memory.
14757744ccdbSTom Lendacky	  This requires an AMD processor that supports Secure Memory
14767744ccdbSTom Lendacky	  Encryption (SME).
14777744ccdbSTom Lendacky
14787744ccdbSTom Lendackyconfig AMD_MEM_ENCRYPT_ACTIVE_BY_DEFAULT
14797744ccdbSTom Lendacky	bool "Activate AMD Secure Memory Encryption (SME) by default"
14807744ccdbSTom Lendacky	default y
14817744ccdbSTom Lendacky	depends on AMD_MEM_ENCRYPT
14827744ccdbSTom Lendacky	---help---
14837744ccdbSTom Lendacky	  Say yes to have system memory encrypted by default if running on
14847744ccdbSTom Lendacky	  an AMD processor that supports Secure Memory Encryption (SME).
14857744ccdbSTom Lendacky
14867744ccdbSTom Lendacky	  If set to Y, then the encryption of system memory can be
14877744ccdbSTom Lendacky	  deactivated with the mem_encrypt=off command line option.
14887744ccdbSTom Lendacky
14897744ccdbSTom Lendacky	  If set to N, then the encryption of system memory can be
14907744ccdbSTom Lendacky	  activated with the mem_encrypt=on command line option.
14917744ccdbSTom Lendacky
1492f88a68faSTom Lendackyconfig ARCH_USE_MEMREMAP_PROT
1493f88a68faSTom Lendacky	def_bool y
1494f88a68faSTom Lendacky	depends on AMD_MEM_ENCRYPT
1495f88a68faSTom Lendacky
1496506f1d07SSam Ravnborg# Common NUMA Features
1497506f1d07SSam Ravnborgconfig NUMA
1498fd51b2d7SKOSAKI Motohiro	bool "Numa Memory Allocation and Scheduler Support"
1499506f1d07SSam Ravnborg	depends on SMP
1500b5660ba7SH. Peter Anvin	depends on X86_64 || (X86_32 && HIGHMEM64G && X86_BIGSMP)
1501b5660ba7SH. Peter Anvin	default y if X86_BIGSMP
15028f9ca475SIngo Molnar	---help---
1503506f1d07SSam Ravnborg	  Enable NUMA (Non Uniform Memory Access) support.
1504fd51b2d7SKOSAKI Motohiro
1505506f1d07SSam Ravnborg	  The kernel will try to allocate memory used by a CPU on the
1506506f1d07SSam Ravnborg	  local memory controller of the CPU and add some more
1507506f1d07SSam Ravnborg	  NUMA awareness to the kernel.
1508506f1d07SSam Ravnborg
1509c280ea5eSIngo Molnar	  For 64-bit this is recommended if the system is Intel Core i7
1510fd51b2d7SKOSAKI Motohiro	  (or later), AMD Opteron, or EM64T NUMA.
1511fd51b2d7SKOSAKI Motohiro
1512b5660ba7SH. Peter Anvin	  For 32-bit this is only needed if you boot a 32-bit
15137cf6c945SDavid Rientjes	  kernel on a 64-bit NUMA platform.
1514fd51b2d7SKOSAKI Motohiro
1515fd51b2d7SKOSAKI Motohiro	  Otherwise, you should say N.
1516506f1d07SSam Ravnborg
1517eec1d4faSHans Rosenfeldconfig AMD_NUMA
15183c2362e6SHarvey Harrison	def_bool y
15193c2362e6SHarvey Harrison	prompt "Old style AMD Opteron NUMA detection"
15205da0ef9aSTejun Heo	depends on X86_64 && NUMA && PCI
15218f9ca475SIngo Molnar	---help---
1522eec1d4faSHans Rosenfeld	  Enable AMD NUMA node topology detection.  You should say Y here if
1523eec1d4faSHans Rosenfeld	  you have a multi processor AMD system. This uses an old method to
1524eec1d4faSHans Rosenfeld	  read the NUMA configuration directly from the builtin Northbridge
1525eec1d4faSHans Rosenfeld	  of Opteron. It is recommended to use X86_64_ACPI_NUMA instead,
1526eec1d4faSHans Rosenfeld	  which also takes priority if both are compiled in.
1527506f1d07SSam Ravnborg
1528506f1d07SSam Ravnborgconfig X86_64_ACPI_NUMA
15293c2362e6SHarvey Harrison	def_bool y
15303c2362e6SHarvey Harrison	prompt "ACPI NUMA detection"
1531506f1d07SSam Ravnborg	depends on X86_64 && NUMA && ACPI && PCI
1532506f1d07SSam Ravnborg	select ACPI_NUMA
15338f9ca475SIngo Molnar	---help---
1534506f1d07SSam Ravnborg	  Enable ACPI SRAT based node topology detection.
1535506f1d07SSam Ravnborg
15366ec6e0d9SSuresh Siddha# Some NUMA nodes have memory ranges that span
15376ec6e0d9SSuresh Siddha# other nodes.  Even though a pfn is valid and
15386ec6e0d9SSuresh Siddha# between a node's start and end pfns, it may not
15396ec6e0d9SSuresh Siddha# reside on that node.  See memmap_init_zone()
15406ec6e0d9SSuresh Siddha# for details.
15416ec6e0d9SSuresh Siddhaconfig NODES_SPAN_OTHER_NODES
15426ec6e0d9SSuresh Siddha	def_bool y
15436ec6e0d9SSuresh Siddha	depends on X86_64_ACPI_NUMA
15446ec6e0d9SSuresh Siddha
1545506f1d07SSam Ravnborgconfig NUMA_EMU
1546506f1d07SSam Ravnborg	bool "NUMA emulation"
15471b7e03efSTejun Heo	depends on NUMA
15488f9ca475SIngo Molnar	---help---
1549506f1d07SSam Ravnborg	  Enable NUMA emulation. A flat machine will be split
1550506f1d07SSam Ravnborg	  into virtual nodes when booted with "numa=fake=N", where N is the
1551506f1d07SSam Ravnborg	  number of nodes. This is only useful for debugging.
1552506f1d07SSam Ravnborg
1553506f1d07SSam Ravnborgconfig NODES_SHIFT
1554d25e26b6SLinus Torvalds	int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP
155551591e31SDavid Rientjes	range 1 10
155651591e31SDavid Rientjes	default "10" if MAXSMP
1557506f1d07SSam Ravnborg	default "6" if X86_64
1558506f1d07SSam Ravnborg	default "3"
1559506f1d07SSam Ravnborg	depends on NEED_MULTIPLE_NODES
15608f9ca475SIngo Molnar	---help---
15611184dc2fSMike Travis	  Specify the maximum number of NUMA Nodes available on the target
1562692105b8SMatt LaPlante	  system.  Increases memory reserved to accommodate various tables.
1563506f1d07SSam Ravnborg
1564506f1d07SSam Ravnborgconfig ARCH_HAVE_MEMORY_PRESENT
15653c2362e6SHarvey Harrison	def_bool y
1566506f1d07SSam Ravnborg	depends on X86_32 && DISCONTIGMEM
1567506f1d07SSam Ravnborg
1568506f1d07SSam Ravnborgconfig NEED_NODE_MEMMAP_SIZE
15693c2362e6SHarvey Harrison	def_bool y
1570506f1d07SSam Ravnborg	depends on X86_32 && (DISCONTIGMEM || SPARSEMEM)
1571506f1d07SSam Ravnborg
1572506f1d07SSam Ravnborgconfig ARCH_FLATMEM_ENABLE
1573506f1d07SSam Ravnborg	def_bool y
15743b16651fSTejun Heo	depends on X86_32 && !NUMA
1575506f1d07SSam Ravnborg
1576506f1d07SSam Ravnborgconfig ARCH_DISCONTIGMEM_ENABLE
1577506f1d07SSam Ravnborg	def_bool y
1578b263295dSChristoph Lameter	depends on NUMA && X86_32
1579506f1d07SSam Ravnborg
1580506f1d07SSam Ravnborgconfig ARCH_DISCONTIGMEM_DEFAULT
1581506f1d07SSam Ravnborg	def_bool y
1582b263295dSChristoph Lameter	depends on NUMA && X86_32
1583b263295dSChristoph Lameter
1584506f1d07SSam Ravnborgconfig ARCH_SPARSEMEM_ENABLE
1585506f1d07SSam Ravnborg	def_bool y
15866ea30386SKees Cook	depends on X86_64 || NUMA || X86_32 || X86_32_NON_STANDARD
1587506f1d07SSam Ravnborg	select SPARSEMEM_STATIC if X86_32
1588506f1d07SSam Ravnborg	select SPARSEMEM_VMEMMAP_ENABLE if X86_64
1589506f1d07SSam Ravnborg
15903b16651fSTejun Heoconfig ARCH_SPARSEMEM_DEFAULT
15913b16651fSTejun Heo	def_bool y
15923b16651fSTejun Heo	depends on X86_64
15933b16651fSTejun Heo
1594506f1d07SSam Ravnborgconfig ARCH_SELECT_MEMORY_MODEL
1595506f1d07SSam Ravnborg	def_bool y
1596b263295dSChristoph Lameter	depends on ARCH_SPARSEMEM_ENABLE
1597506f1d07SSam Ravnborg
1598506f1d07SSam Ravnborgconfig ARCH_MEMORY_PROBE
1599a0842b70SToshi Kani	bool "Enable sysfs memory/probe interface"
16003120e25eSJan Beulich	depends on X86_64 && MEMORY_HOTPLUG
1601a0842b70SToshi Kani	help
1602a0842b70SToshi Kani	  This option enables a sysfs memory/probe interface for testing.
1603a0842b70SToshi Kani	  See Documentation/memory-hotplug.txt for more information.
1604a0842b70SToshi Kani	  If you are unsure how to answer this question, answer N.
1605506f1d07SSam Ravnborg
16063b16651fSTejun Heoconfig ARCH_PROC_KCORE_TEXT
16073b16651fSTejun Heo	def_bool y
16083b16651fSTejun Heo	depends on X86_64 && PROC_KCORE
16093b16651fSTejun Heo
1610a29815a3SAvi Kivityconfig ILLEGAL_POINTER_VALUE
1611a29815a3SAvi Kivity       hex
1612a29815a3SAvi Kivity       default 0 if X86_32
1613a29815a3SAvi Kivity       default 0xdead000000000000 if X86_64
1614a29815a3SAvi Kivity
1615506f1d07SSam Ravnborgsource "mm/Kconfig"
1616506f1d07SSam Ravnborg
16177a67832cSDan Williamsconfig X86_PMEM_LEGACY_DEVICE
16187a67832cSDan Williams	bool
16197a67832cSDan Williams
1620ec776ef6SChristoph Hellwigconfig X86_PMEM_LEGACY
16217a67832cSDan Williams	tristate "Support non-standard NVDIMMs and ADR protected memory"
16229f53f9faSDan Williams	depends on PHYS_ADDR_T_64BIT
16239f53f9faSDan Williams	depends on BLK_DEV
16247a67832cSDan Williams	select X86_PMEM_LEGACY_DEVICE
16259f53f9faSDan Williams	select LIBNVDIMM
1626ec776ef6SChristoph Hellwig	help
1627ec776ef6SChristoph Hellwig	  Treat memory marked using the non-standard e820 type of 12 as used
1628ec776ef6SChristoph Hellwig	  by the Intel Sandy Bridge-EP reference BIOS as protected memory.
1629ec776ef6SChristoph Hellwig	  The kernel will offer these regions to the 'pmem' driver so
1630ec776ef6SChristoph Hellwig	  they can be used for persistent storage.
1631ec776ef6SChristoph Hellwig
1632ec776ef6SChristoph Hellwig	  Say Y if unsure.
1633ec776ef6SChristoph Hellwig
1634506f1d07SSam Ravnborgconfig HIGHPTE
1635506f1d07SSam Ravnborg	bool "Allocate 3rd-level pagetables from highmem"
16366fc108a0SJan Beulich	depends on HIGHMEM
16378f9ca475SIngo Molnar	---help---
1638506f1d07SSam Ravnborg	  The VM uses one page table entry for each page of physical memory.
1639506f1d07SSam Ravnborg	  For systems with a lot of RAM, this can be wasteful of precious
1640506f1d07SSam Ravnborg	  low memory.  Setting this option will put user-space page table
1641506f1d07SSam Ravnborg	  entries in high memory.
1642506f1d07SSam Ravnborg
16439f077871SJeremy Fitzhardingeconfig X86_CHECK_BIOS_CORRUPTION
16449f077871SJeremy Fitzhardinge	bool "Check for low memory corruption"
16458f9ca475SIngo Molnar	---help---
16469f077871SJeremy Fitzhardinge	  Periodically check for memory corruption in low memory, which
16479f077871SJeremy Fitzhardinge	  is suspected to be caused by BIOS.  Even when enabled in the
16489f077871SJeremy Fitzhardinge	  configuration, it is disabled at runtime.  Enable it by
16499f077871SJeremy Fitzhardinge	  setting "memory_corruption_check=1" on the kernel command
16509f077871SJeremy Fitzhardinge	  line.  By default it scans the low 64k of memory every 60
16519f077871SJeremy Fitzhardinge	  seconds; see the memory_corruption_check_size and
16529f077871SJeremy Fitzhardinge	  memory_corruption_check_period parameters in
16538c27ceffSMauro Carvalho Chehab	  Documentation/admin-guide/kernel-parameters.rst to adjust this.
16549f077871SJeremy Fitzhardinge
16559f077871SJeremy Fitzhardinge	  When enabled with the default parameters, this option has
16569f077871SJeremy Fitzhardinge	  almost no overhead, as it reserves a relatively small amount
16579f077871SJeremy Fitzhardinge	  of memory and scans it infrequently.  It both detects corruption
16589f077871SJeremy Fitzhardinge	  and prevents it from affecting the running system.
16599f077871SJeremy Fitzhardinge
16609f077871SJeremy Fitzhardinge	  It is, however, intended as a diagnostic tool; if repeatable
16619f077871SJeremy Fitzhardinge	  BIOS-originated corruption always affects the same memory,
16629f077871SJeremy Fitzhardinge	  you can use memmap= to prevent the kernel from using that
16639f077871SJeremy Fitzhardinge	  memory.
16649f077871SJeremy Fitzhardinge
1665c885df50SJeremy Fitzhardingeconfig X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK
1666c885df50SJeremy Fitzhardinge	bool "Set the default setting of memory_corruption_check"
1667c885df50SJeremy Fitzhardinge	depends on X86_CHECK_BIOS_CORRUPTION
1668c885df50SJeremy Fitzhardinge	default y
16698f9ca475SIngo Molnar	---help---
1670c885df50SJeremy Fitzhardinge	  Set whether the default state of memory_corruption_check is
1671c885df50SJeremy Fitzhardinge	  on or off.
1672c885df50SJeremy Fitzhardinge
16739ea77bdbSH. Peter Anvinconfig X86_RESERVE_LOW
1674d0cd7425SH. Peter Anvin	int "Amount of low memory, in kilobytes, to reserve for the BIOS"
1675d0cd7425SH. Peter Anvin	default 64
1676d0cd7425SH. Peter Anvin	range 4 640
16778f9ca475SIngo Molnar	---help---
1678d0cd7425SH. Peter Anvin	  Specify the amount of low memory to reserve for the BIOS.
1679fc381519SIngo Molnar
1680d0cd7425SH. Peter Anvin	  The first page contains BIOS data structures that the kernel
1681d0cd7425SH. Peter Anvin	  must not use, so that page must always be reserved.
1682fc381519SIngo Molnar
1683d0cd7425SH. Peter Anvin	  By default we reserve the first 64K of physical RAM, as a
1684d0cd7425SH. Peter Anvin	  number of BIOSes are known to corrupt that memory range
1685d0cd7425SH. Peter Anvin	  during events such as suspend/resume or monitor cable
1686d0cd7425SH. Peter Anvin	  insertion, so it must not be used by the kernel.
1687fc381519SIngo Molnar
1688d0cd7425SH. Peter Anvin	  You can set this to 4 if you are absolutely sure that you
1689d0cd7425SH. Peter Anvin	  trust the BIOS to get all its memory reservations and usages
1690d0cd7425SH. Peter Anvin	  right.  If you know your BIOS have problems beyond the
1691d0cd7425SH. Peter Anvin	  default 64K area, you can set this to 640 to avoid using the
1692d0cd7425SH. Peter Anvin	  entire low memory range.
1693d0cd7425SH. Peter Anvin
1694d0cd7425SH. Peter Anvin	  If you have doubts about the BIOS (e.g. suspend/resume does
1695d0cd7425SH. Peter Anvin	  not work or there's kernel crashes after certain hardware
1696d0cd7425SH. Peter Anvin	  hotplug events) then you might want to enable
1697d0cd7425SH. Peter Anvin	  X86_CHECK_BIOS_CORRUPTION=y to allow the kernel to check
1698d0cd7425SH. Peter Anvin	  typical corruption patterns.
1699d0cd7425SH. Peter Anvin
1700d0cd7425SH. Peter Anvin	  Leave this to the default value of 64 if you are unsure.
1701fc381519SIngo Molnar
1702506f1d07SSam Ravnborgconfig MATH_EMULATION
1703506f1d07SSam Ravnborg	bool
1704a5b9e5a2SAndy Lutomirski	depends on MODIFY_LDT_SYSCALL
1705506f1d07SSam Ravnborg	prompt "Math emulation" if X86_32
1706506f1d07SSam Ravnborg	---help---
1707506f1d07SSam Ravnborg	  Linux can emulate a math coprocessor (used for floating point
1708506f1d07SSam Ravnborg	  operations) if you don't have one. 486DX and Pentium processors have
1709506f1d07SSam Ravnborg	  a math coprocessor built in, 486SX and 386 do not, unless you added
1710506f1d07SSam Ravnborg	  a 487DX or 387, respectively. (The messages during boot time can
1711506f1d07SSam Ravnborg	  give you some hints here ["man dmesg"].) Everyone needs either a
1712506f1d07SSam Ravnborg	  coprocessor or this emulation.
1713506f1d07SSam Ravnborg
1714506f1d07SSam Ravnborg	  If you don't have a math coprocessor, you need to say Y here; if you
1715506f1d07SSam Ravnborg	  say Y here even though you have a coprocessor, the coprocessor will
1716506f1d07SSam Ravnborg	  be used nevertheless. (This behavior can be changed with the kernel
1717506f1d07SSam Ravnborg	  command line option "no387", which comes handy if your coprocessor
1718506f1d07SSam Ravnborg	  is broken. Try "man bootparam" or see the documentation of your boot
1719506f1d07SSam Ravnborg	  loader (lilo or loadlin) about how to pass options to the kernel at
1720506f1d07SSam Ravnborg	  boot time.) This means that it is a good idea to say Y here if you
1721506f1d07SSam Ravnborg	  intend to use this kernel on different machines.
1722506f1d07SSam Ravnborg
1723506f1d07SSam Ravnborg	  More information about the internals of the Linux math coprocessor
1724506f1d07SSam Ravnborg	  emulation can be found in <file:arch/x86/math-emu/README>.
1725506f1d07SSam Ravnborg
1726506f1d07SSam Ravnborg	  If you are not sure, say Y; apart from resulting in a 66 KB bigger
1727506f1d07SSam Ravnborg	  kernel, it won't hurt.
1728506f1d07SSam Ravnborg
1729506f1d07SSam Ravnborgconfig MTRR
17306fc108a0SJan Beulich	def_bool y
17316a108a14SDavid Rientjes	prompt "MTRR (Memory Type Range Register) support" if EXPERT
1732506f1d07SSam Ravnborg	---help---
1733506f1d07SSam Ravnborg	  On Intel P6 family processors (Pentium Pro, Pentium II and later)
1734506f1d07SSam Ravnborg	  the Memory Type Range Registers (MTRRs) may be used to control
1735506f1d07SSam Ravnborg	  processor access to memory ranges. This is most useful if you have
1736506f1d07SSam Ravnborg	  a video (VGA) card on a PCI or AGP bus. Enabling write-combining
1737506f1d07SSam Ravnborg	  allows bus write transfers to be combined into a larger transfer
1738506f1d07SSam Ravnborg	  before bursting over the PCI/AGP bus. This can increase performance
1739506f1d07SSam Ravnborg	  of image write operations 2.5 times or more. Saying Y here creates a
1740506f1d07SSam Ravnborg	  /proc/mtrr file which may be used to manipulate your processor's
1741506f1d07SSam Ravnborg	  MTRRs. Typically the X server should use this.
1742506f1d07SSam Ravnborg
1743506f1d07SSam Ravnborg	  This code has a reasonably generic interface so that similar
1744506f1d07SSam Ravnborg	  control registers on other processors can be easily supported
1745506f1d07SSam Ravnborg	  as well:
1746506f1d07SSam Ravnborg
1747506f1d07SSam Ravnborg	  The Cyrix 6x86, 6x86MX and M II processors have Address Range
1748506f1d07SSam Ravnborg	  Registers (ARRs) which provide a similar functionality to MTRRs. For
1749506f1d07SSam Ravnborg	  these, the ARRs are used to emulate the MTRRs.
1750506f1d07SSam Ravnborg	  The AMD K6-2 (stepping 8 and above) and K6-3 processors have two
1751506f1d07SSam Ravnborg	  MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing
1752506f1d07SSam Ravnborg	  write-combining. All of these processors are supported by this code
1753506f1d07SSam Ravnborg	  and it makes sense to say Y here if you have one of them.
1754506f1d07SSam Ravnborg
1755506f1d07SSam Ravnborg	  Saying Y here also fixes a problem with buggy SMP BIOSes which only
1756506f1d07SSam Ravnborg	  set the MTRRs for the boot CPU and not for the secondary CPUs. This
1757506f1d07SSam Ravnborg	  can lead to all sorts of problems, so it's good to say Y here.
1758506f1d07SSam Ravnborg
1759506f1d07SSam Ravnborg	  You can safely say Y even if your machine doesn't have MTRRs, you'll
1760506f1d07SSam Ravnborg	  just add about 9 KB to your kernel.
1761506f1d07SSam Ravnborg
17627225e751SRandy Dunlap	  See <file:Documentation/x86/mtrr.txt> for more information.
1763506f1d07SSam Ravnborg
176495ffa243SYinghai Luconfig MTRR_SANITIZER
17652ffb3501SYinghai Lu	def_bool y
176695ffa243SYinghai Lu	prompt "MTRR cleanup support"
176795ffa243SYinghai Lu	depends on MTRR
17688f9ca475SIngo Molnar	---help---
1769aba3728cSThomas Gleixner	  Convert MTRR layout from continuous to discrete, so X drivers can
1770aba3728cSThomas Gleixner	  add writeback entries.
177195ffa243SYinghai Lu
1772aba3728cSThomas Gleixner	  Can be disabled with disable_mtrr_cleanup on the kernel command line.
1773692105b8SMatt LaPlante	  The largest mtrr entry size for a continuous block can be set with
1774aba3728cSThomas Gleixner	  mtrr_chunk_size.
177595ffa243SYinghai Lu
17762ffb3501SYinghai Lu	  If unsure, say Y.
177795ffa243SYinghai Lu
177895ffa243SYinghai Luconfig MTRR_SANITIZER_ENABLE_DEFAULT
1779f5098d62SYinghai Lu	int "MTRR cleanup enable value (0-1)"
1780f5098d62SYinghai Lu	range 0 1
1781f5098d62SYinghai Lu	default "0"
178295ffa243SYinghai Lu	depends on MTRR_SANITIZER
17838f9ca475SIngo Molnar	---help---
1784f5098d62SYinghai Lu	  Enable mtrr cleanup default value
178595ffa243SYinghai Lu
178612031a62SYinghai Luconfig MTRR_SANITIZER_SPARE_REG_NR_DEFAULT
178712031a62SYinghai Lu	int "MTRR cleanup spare reg num (0-7)"
178812031a62SYinghai Lu	range 0 7
178912031a62SYinghai Lu	default "1"
179012031a62SYinghai Lu	depends on MTRR_SANITIZER
17918f9ca475SIngo Molnar	---help---
179212031a62SYinghai Lu	  mtrr cleanup spare entries default, it can be changed via
1793aba3728cSThomas Gleixner	  mtrr_spare_reg_nr=N on the kernel command line.
179412031a62SYinghai Lu
17952e5d9c85Svenkatesh.pallipadi@intel.comconfig X86_PAT
17966fc108a0SJan Beulich	def_bool y
17976a108a14SDavid Rientjes	prompt "x86 PAT support" if EXPERT
17982a8a2719SIngo Molnar	depends on MTRR
17998f9ca475SIngo Molnar	---help---
18002e5d9c85Svenkatesh.pallipadi@intel.com	  Use PAT attributes to setup page level cache control.
1801042b78e4SVenki Pallipadi
18022e5d9c85Svenkatesh.pallipadi@intel.com	  PATs are the modern equivalents of MTRRs and are much more
18032e5d9c85Svenkatesh.pallipadi@intel.com	  flexible than MTRRs.
18042e5d9c85Svenkatesh.pallipadi@intel.com
18052e5d9c85Svenkatesh.pallipadi@intel.com	  Say N here if you see bootup problems (boot crash, boot hang,
1806042b78e4SVenki Pallipadi	  spontaneous reboots) or a non-working video driver.
18072e5d9c85Svenkatesh.pallipadi@intel.com
18082e5d9c85Svenkatesh.pallipadi@intel.com	  If unsure, say Y.
18092e5d9c85Svenkatesh.pallipadi@intel.com
181046cf98cdSVenkatesh Pallipadiconfig ARCH_USES_PG_UNCACHED
181146cf98cdSVenkatesh Pallipadi	def_bool y
181246cf98cdSVenkatesh Pallipadi	depends on X86_PAT
181346cf98cdSVenkatesh Pallipadi
1814628c6246SH. Peter Anvinconfig ARCH_RANDOM
1815628c6246SH. Peter Anvin	def_bool y
1816628c6246SH. Peter Anvin	prompt "x86 architectural random number generator" if EXPERT
1817628c6246SH. Peter Anvin	---help---
1818628c6246SH. Peter Anvin	  Enable the x86 architectural RDRAND instruction
1819628c6246SH. Peter Anvin	  (Intel Bull Mountain technology) to generate random numbers.
1820628c6246SH. Peter Anvin	  If supported, this is a high bandwidth, cryptographically
1821628c6246SH. Peter Anvin	  secure hardware random number generator.
1822628c6246SH. Peter Anvin
182351ae4a2dSH. Peter Anvinconfig X86_SMAP
182451ae4a2dSH. Peter Anvin	def_bool y
182551ae4a2dSH. Peter Anvin	prompt "Supervisor Mode Access Prevention" if EXPERT
182651ae4a2dSH. Peter Anvin	---help---
182751ae4a2dSH. Peter Anvin	  Supervisor Mode Access Prevention (SMAP) is a security
182851ae4a2dSH. Peter Anvin	  feature in newer Intel processors.  There is a small
182951ae4a2dSH. Peter Anvin	  performance cost if this enabled and turned on; there is
183051ae4a2dSH. Peter Anvin	  also a small increase in the kernel size if this is enabled.
183151ae4a2dSH. Peter Anvin
183251ae4a2dSH. Peter Anvin	  If unsure, say Y.
183351ae4a2dSH. Peter Anvin
1834aa35f896SRicardo Nericonfig X86_INTEL_UMIP
1835796ebc81SRicardo Neri	def_bool y
1836aa35f896SRicardo Neri	depends on CPU_SUP_INTEL
1837aa35f896SRicardo Neri	prompt "Intel User Mode Instruction Prevention" if EXPERT
1838aa35f896SRicardo Neri	---help---
1839aa35f896SRicardo Neri	  The User Mode Instruction Prevention (UMIP) is a security
1840aa35f896SRicardo Neri	  feature in newer Intel processors. If enabled, a general
1841796ebc81SRicardo Neri	  protection fault is issued if the SGDT, SLDT, SIDT, SMSW
1842796ebc81SRicardo Neri	  or STR instructions are executed in user mode. These instructions
1843796ebc81SRicardo Neri	  unnecessarily expose information about the hardware state.
1844796ebc81SRicardo Neri
1845796ebc81SRicardo Neri	  The vast majority of applications do not use these instructions.
1846796ebc81SRicardo Neri	  For the very few that do, software emulation is provided in
1847796ebc81SRicardo Neri	  specific cases in protected and virtual-8086 modes. Emulated
1848796ebc81SRicardo Neri	  results are dummy.
1849aa35f896SRicardo Neri
185072e9b5feSDave Hansenconfig X86_INTEL_MPX
185172e9b5feSDave Hansen	prompt "Intel MPX (Memory Protection Extensions)"
185272e9b5feSDave Hansen	def_bool n
1853df3735c5SRik van Riel	# Note: only available in 64-bit mode due to VMA flags shortage
1854df3735c5SRik van Riel	depends on CPU_SUP_INTEL && X86_64
1855df3735c5SRik van Riel	select ARCH_USES_HIGH_VMA_FLAGS
185672e9b5feSDave Hansen	---help---
185772e9b5feSDave Hansen	  MPX provides hardware features that can be used in
185872e9b5feSDave Hansen	  conjunction with compiler-instrumented code to check
185972e9b5feSDave Hansen	  memory references.  It is designed to detect buffer
186072e9b5feSDave Hansen	  overflow or underflow bugs.
186172e9b5feSDave Hansen
186272e9b5feSDave Hansen	  This option enables running applications which are
186372e9b5feSDave Hansen	  instrumented or otherwise use MPX.  It does not use MPX
186472e9b5feSDave Hansen	  itself inside the kernel or to protect the kernel
186572e9b5feSDave Hansen	  against bad memory references.
186672e9b5feSDave Hansen
186772e9b5feSDave Hansen	  Enabling this option will make the kernel larger:
186872e9b5feSDave Hansen	  ~8k of kernel text and 36 bytes of data on a 64-bit
186972e9b5feSDave Hansen	  defconfig.  It adds a long to the 'mm_struct' which
187072e9b5feSDave Hansen	  will increase the kernel memory overhead of each
187172e9b5feSDave Hansen	  process and adds some branches to paths used during
187272e9b5feSDave Hansen	  exec() and munmap().
187372e9b5feSDave Hansen
187472e9b5feSDave Hansen	  For details, see Documentation/x86/intel_mpx.txt
187572e9b5feSDave Hansen
187672e9b5feSDave Hansen	  If unsure, say N.
187772e9b5feSDave Hansen
187835e97790SDave Hansenconfig X86_INTEL_MEMORY_PROTECTION_KEYS
1879284244a9SDave Hansen	prompt "Intel Memory Protection Keys"
188035e97790SDave Hansen	def_bool y
1881284244a9SDave Hansen	# Note: only available in 64-bit mode
188235e97790SDave Hansen	depends on CPU_SUP_INTEL && X86_64
188352c8e601SIngo Molnar	select ARCH_USES_HIGH_VMA_FLAGS
188452c8e601SIngo Molnar	select ARCH_HAS_PKEYS
1885284244a9SDave Hansen	---help---
1886284244a9SDave Hansen	  Memory Protection Keys provides a mechanism for enforcing
1887284244a9SDave Hansen	  page-based protections, but without requiring modification of the
1888284244a9SDave Hansen	  page tables when an application changes protection domains.
1889284244a9SDave Hansen
1890284244a9SDave Hansen	  For details, see Documentation/x86/protection-keys.txt
1891284244a9SDave Hansen
1892284244a9SDave Hansen	  If unsure, say y.
189335e97790SDave Hansen
1894506f1d07SSam Ravnborgconfig EFI
18959ba16087SJan Beulich	bool "EFI runtime service support"
18965b83683fSHuang, Ying	depends on ACPI
1897f6ce5002SSergey Vlasov	select UCS2_STRING
1898022ee6c5SArd Biesheuvel	select EFI_RUNTIME_WRAPPERS
1899506f1d07SSam Ravnborg	---help---
19008b2cb7a8SHuang, Ying	  This enables the kernel to use EFI runtime services that are
1901506f1d07SSam Ravnborg	  available (such as the EFI variable services).
1902506f1d07SSam Ravnborg
19038b2cb7a8SHuang, Ying	  This option is only useful on systems that have EFI firmware.
19048b2cb7a8SHuang, Ying	  In addition, you should use the latest ELILO loader available
19058b2cb7a8SHuang, Ying	  at <http://elilo.sourceforge.net> in order to take advantage
19068b2cb7a8SHuang, Ying	  of EFI runtime services. However, even with this option, the
19078b2cb7a8SHuang, Ying	  resultant kernel should continue to boot on existing non-EFI
19088b2cb7a8SHuang, Ying	  platforms.
1909506f1d07SSam Ravnborg
1910291f3632SMatt Flemingconfig EFI_STUB
1911291f3632SMatt Fleming       bool "EFI stub support"
1912b16d8c23SMatt Fleming       depends on EFI && !X86_USE_3DNOW
19137b2a583aSMatt Fleming       select RELOCATABLE
1914291f3632SMatt Fleming       ---help---
1915291f3632SMatt Fleming          This kernel feature allows a bzImage to be loaded directly
1916291f3632SMatt Fleming	  by EFI firmware without the use of a bootloader.
1917291f3632SMatt Fleming
19184172fe2fSRoy Franz	  See Documentation/efi-stub.txt for more information.
19190c759662SMatt Fleming
19207d453eeeSMatt Flemingconfig EFI_MIXED
19217d453eeeSMatt Fleming	bool "EFI mixed-mode support"
19227d453eeeSMatt Fleming	depends on EFI_STUB && X86_64
19237d453eeeSMatt Fleming	---help---
19247d453eeeSMatt Fleming	   Enabling this feature allows a 64-bit kernel to be booted
19257d453eeeSMatt Fleming	   on a 32-bit firmware, provided that your CPU supports 64-bit
19267d453eeeSMatt Fleming	   mode.
19277d453eeeSMatt Fleming
19287d453eeeSMatt Fleming	   Note that it is not possible to boot a mixed-mode enabled
19297d453eeeSMatt Fleming	   kernel via the EFI boot stub - a bootloader that supports
19307d453eeeSMatt Fleming	   the EFI handover protocol must be used.
19317d453eeeSMatt Fleming
19327d453eeeSMatt Fleming	   If unsure, say N.
19337d453eeeSMatt Fleming
1934506f1d07SSam Ravnborgconfig SECCOMP
19353c2362e6SHarvey Harrison	def_bool y
19363c2362e6SHarvey Harrison	prompt "Enable seccomp to safely compute untrusted bytecode"
19378f9ca475SIngo Molnar	---help---
1938506f1d07SSam Ravnborg	  This kernel feature is useful for number crunching applications
1939506f1d07SSam Ravnborg	  that may need to compute untrusted bytecode during their
1940506f1d07SSam Ravnborg	  execution. By using pipes or other transports made available to
1941506f1d07SSam Ravnborg	  the process as file descriptors supporting the read/write
1942506f1d07SSam Ravnborg	  syscalls, it's possible to isolate those applications in
1943506f1d07SSam Ravnborg	  their own address space using seccomp. Once seccomp is
19449c0bbee8SAlexey Dobriyan	  enabled via prctl(PR_SET_SECCOMP), it cannot be disabled
1945506f1d07SSam Ravnborg	  and the task is only allowed to execute a few safe syscalls
1946506f1d07SSam Ravnborg	  defined by each seccomp mode.
1947506f1d07SSam Ravnborg
1948506f1d07SSam Ravnborg	  If unsure, say Y. Only embedded should say N here.
1949506f1d07SSam Ravnborg
1950506f1d07SSam Ravnborgsource kernel/Kconfig.hz
1951506f1d07SSam Ravnborg
1952506f1d07SSam Ravnborgconfig KEXEC
1953506f1d07SSam Ravnborg	bool "kexec system call"
19542965faa5SDave Young	select KEXEC_CORE
19558f9ca475SIngo Molnar	---help---
1956506f1d07SSam Ravnborg	  kexec is a system call that implements the ability to shutdown your
1957506f1d07SSam Ravnborg	  current kernel, and to start another kernel.  It is like a reboot
1958506f1d07SSam Ravnborg	  but it is independent of the system firmware.   And like a reboot
1959506f1d07SSam Ravnborg	  you can start any kernel with it, not just Linux.
1960506f1d07SSam Ravnborg
1961506f1d07SSam Ravnborg	  The name comes from the similarity to the exec system call.
1962506f1d07SSam Ravnborg
1963506f1d07SSam Ravnborg	  It is an ongoing process to be certain the hardware in a machine
1964506f1d07SSam Ravnborg	  is properly shutdown, so do not be surprised if this code does not
1965bf220695SGeert Uytterhoeven	  initially work for you.  As of this writing the exact hardware
1966bf220695SGeert Uytterhoeven	  interface is strongly in flux, so no good recommendation can be
1967bf220695SGeert Uytterhoeven	  made.
1968506f1d07SSam Ravnborg
196974ca317cSVivek Goyalconfig KEXEC_FILE
197074ca317cSVivek Goyal	bool "kexec file based system call"
19712965faa5SDave Young	select KEXEC_CORE
197274ca317cSVivek Goyal	select BUILD_BIN2C
197374ca317cSVivek Goyal	depends on X86_64
197474ca317cSVivek Goyal	depends on CRYPTO=y
197574ca317cSVivek Goyal	depends on CRYPTO_SHA256=y
197674ca317cSVivek Goyal	---help---
197774ca317cSVivek Goyal	  This is new version of kexec system call. This system call is
197874ca317cSVivek Goyal	  file based and takes file descriptors as system call argument
197974ca317cSVivek Goyal	  for kernel and initramfs as opposed to list of segments as
198074ca317cSVivek Goyal	  accepted by previous system call.
198174ca317cSVivek Goyal
19828e7d8381SVivek Goyalconfig KEXEC_VERIFY_SIG
19838e7d8381SVivek Goyal	bool "Verify kernel signature during kexec_file_load() syscall"
198474ca317cSVivek Goyal	depends on KEXEC_FILE
19858e7d8381SVivek Goyal	---help---
19868e7d8381SVivek Goyal	  This option makes kernel signature verification mandatory for
1987d8eb8940SBorislav Petkov	  the kexec_file_load() syscall.
19888e7d8381SVivek Goyal
1989d8eb8940SBorislav Petkov	  In addition to that option, you need to enable signature
1990d8eb8940SBorislav Petkov	  verification for the corresponding kernel image type being
1991d8eb8940SBorislav Petkov	  loaded in order for this to work.
19928e7d8381SVivek Goyal
19938e7d8381SVivek Goyalconfig KEXEC_BZIMAGE_VERIFY_SIG
19948e7d8381SVivek Goyal	bool "Enable bzImage signature verification support"
19958e7d8381SVivek Goyal	depends on KEXEC_VERIFY_SIG
19968e7d8381SVivek Goyal	depends on SIGNED_PE_FILE_VERIFICATION
19978e7d8381SVivek Goyal	select SYSTEM_TRUSTED_KEYRING
19988e7d8381SVivek Goyal	---help---
19998e7d8381SVivek Goyal	  Enable bzImage signature verification support.
20008e7d8381SVivek Goyal
2001506f1d07SSam Ravnborgconfig CRASH_DUMP
200204b69447SPavel Machek	bool "kernel crash dumps"
2003506f1d07SSam Ravnborg	depends on X86_64 || (X86_32 && HIGHMEM)
20048f9ca475SIngo Molnar	---help---
2005506f1d07SSam Ravnborg	  Generate crash dump after being started by kexec.
2006506f1d07SSam Ravnborg	  This should be normally only set in special crash dump kernels
2007506f1d07SSam Ravnborg	  which are loaded in the main kernel with kexec-tools into
2008506f1d07SSam Ravnborg	  a specially reserved region and then later executed after
2009506f1d07SSam Ravnborg	  a crash by kdump/kexec. The crash dump kernel must be compiled
2010506f1d07SSam Ravnborg	  to a memory address not used by the main kernel or BIOS using
2011506f1d07SSam Ravnborg	  PHYSICAL_START, or it must be built as a relocatable image
2012506f1d07SSam Ravnborg	  (CONFIG_RELOCATABLE=y).
2013506f1d07SSam Ravnborg	  For more details see Documentation/kdump/kdump.txt
2014506f1d07SSam Ravnborg
20153ab83521SHuang Yingconfig KEXEC_JUMP
20166ea30386SKees Cook	bool "kexec jump"
2017fee7b0d8SHuang Ying	depends on KEXEC && HIBERNATION
20188f9ca475SIngo Molnar	---help---
201989081d17SHuang Ying	  Jump between original kernel and kexeced kernel and invoke
202089081d17SHuang Ying	  code in physical address mode via KEXEC
20213ab83521SHuang Ying
2022506f1d07SSam Ravnborgconfig PHYSICAL_START
20236a108a14SDavid Rientjes	hex "Physical address where the kernel is loaded" if (EXPERT || CRASH_DUMP)
2024ceefccc9SH. Peter Anvin	default "0x1000000"
20258f9ca475SIngo Molnar	---help---
2026506f1d07SSam Ravnborg	  This gives the physical address where the kernel is loaded.
2027506f1d07SSam Ravnborg
2028506f1d07SSam Ravnborg	  If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then
2029506f1d07SSam Ravnborg	  bzImage will decompress itself to above physical address and
2030506f1d07SSam Ravnborg	  run from there. Otherwise, bzImage will run from the address where
2031506f1d07SSam Ravnborg	  it has been loaded by the boot loader and will ignore above physical
2032506f1d07SSam Ravnborg	  address.
2033506f1d07SSam Ravnborg
2034506f1d07SSam Ravnborg	  In normal kdump cases one does not have to set/change this option
2035506f1d07SSam Ravnborg	  as now bzImage can be compiled as a completely relocatable image
2036506f1d07SSam Ravnborg	  (CONFIG_RELOCATABLE=y) and be used to load and run from a different
2037506f1d07SSam Ravnborg	  address. This option is mainly useful for the folks who don't want
2038506f1d07SSam Ravnborg	  to use a bzImage for capturing the crash dump and want to use a
2039506f1d07SSam Ravnborg	  vmlinux instead. vmlinux is not relocatable hence a kernel needs
2040506f1d07SSam Ravnborg	  to be specifically compiled to run from a specific memory area
2041506f1d07SSam Ravnborg	  (normally a reserved region) and this option comes handy.
2042506f1d07SSam Ravnborg
2043ceefccc9SH. Peter Anvin	  So if you are using bzImage for capturing the crash dump,
2044ceefccc9SH. Peter Anvin	  leave the value here unchanged to 0x1000000 and set
2045ceefccc9SH. Peter Anvin	  CONFIG_RELOCATABLE=y.  Otherwise if you plan to use vmlinux
2046ceefccc9SH. Peter Anvin	  for capturing the crash dump change this value to start of
2047ceefccc9SH. Peter Anvin	  the reserved region.  In other words, it can be set based on
2048ceefccc9SH. Peter Anvin	  the "X" value as specified in the "crashkernel=YM@XM"
2049ceefccc9SH. Peter Anvin	  command line boot parameter passed to the panic-ed
2050ceefccc9SH. Peter Anvin	  kernel. Please take a look at Documentation/kdump/kdump.txt
2051ceefccc9SH. Peter Anvin	  for more details about crash dumps.
2052506f1d07SSam Ravnborg
2053506f1d07SSam Ravnborg	  Usage of bzImage for capturing the crash dump is recommended as
2054506f1d07SSam Ravnborg	  one does not have to build two kernels. Same kernel can be used
2055506f1d07SSam Ravnborg	  as production kernel and capture kernel. Above option should have
2056506f1d07SSam Ravnborg	  gone away after relocatable bzImage support is introduced. But it
2057506f1d07SSam Ravnborg	  is present because there are users out there who continue to use
2058506f1d07SSam Ravnborg	  vmlinux for dump capture. This option should go away down the
2059506f1d07SSam Ravnborg	  line.
2060506f1d07SSam Ravnborg
2061506f1d07SSam Ravnborg	  Don't change this unless you know what you are doing.
2062506f1d07SSam Ravnborg
2063506f1d07SSam Ravnborgconfig RELOCATABLE
206426717808SH. Peter Anvin	bool "Build a relocatable kernel"
206526717808SH. Peter Anvin	default y
20668f9ca475SIngo Molnar	---help---
2067506f1d07SSam Ravnborg	  This builds a kernel image that retains relocation information
2068506f1d07SSam Ravnborg	  so it can be loaded someplace besides the default 1MB.
2069506f1d07SSam Ravnborg	  The relocations tend to make the kernel binary about 10% larger,
2070506f1d07SSam Ravnborg	  but are discarded at runtime.
2071506f1d07SSam Ravnborg
2072506f1d07SSam Ravnborg	  One use is for the kexec on panic case where the recovery kernel
2073506f1d07SSam Ravnborg	  must live at a different physical address than the primary
2074506f1d07SSam Ravnborg	  kernel.
2075506f1d07SSam Ravnborg
2076506f1d07SSam Ravnborg	  Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address
2077506f1d07SSam Ravnborg	  it has been loaded at and the compile time physical address
20788ab3820fSKees Cook	  (CONFIG_PHYSICAL_START) is used as the minimum location.
2079506f1d07SSam Ravnborg
20808ab3820fSKees Cookconfig RANDOMIZE_BASE
2081e8581e3dSBaoquan He	bool "Randomize the address of the kernel image (KASLR)"
20828ab3820fSKees Cook	depends on RELOCATABLE
20836807c846SIngo Molnar	default y
20848ab3820fSKees Cook	---help---
2085e8581e3dSBaoquan He	  In support of Kernel Address Space Layout Randomization (KASLR),
2086e8581e3dSBaoquan He	  this randomizes the physical address at which the kernel image
2087e8581e3dSBaoquan He	  is decompressed and the virtual address where the kernel
2088e8581e3dSBaoquan He	  image is mapped, as a security feature that deters exploit
2089e8581e3dSBaoquan He	  attempts relying on knowledge of the location of kernel
2090e8581e3dSBaoquan He	  code internals.
2091e8581e3dSBaoquan He
2092ed9f007eSKees Cook	  On 64-bit, the kernel physical and virtual addresses are
2093ed9f007eSKees Cook	  randomized separately. The physical address will be anywhere
2094ed9f007eSKees Cook	  between 16MB and the top of physical memory (up to 64TB). The
2095ed9f007eSKees Cook	  virtual address will be randomized from 16MB up to 1GB (9 bits
2096ed9f007eSKees Cook	  of entropy). Note that this also reduces the memory space
2097ed9f007eSKees Cook	  available to kernel modules from 1.5GB to 1GB.
2098ed9f007eSKees Cook
2099ed9f007eSKees Cook	  On 32-bit, the kernel physical and virtual addresses are
2100ed9f007eSKees Cook	  randomized together. They will be randomized from 16MB up to
2101ed9f007eSKees Cook	  512MB (8 bits of entropy).
21028ab3820fSKees Cook
2103a653f356SKees Cook	  Entropy is generated using the RDRAND instruction if it is
2104e8581e3dSBaoquan He	  supported. If RDTSC is supported, its value is mixed into
2105e8581e3dSBaoquan He	  the entropy pool as well. If neither RDRAND nor RDTSC are
2106ed9f007eSKees Cook	  supported, then entropy is read from the i8254 timer. The
2107ed9f007eSKees Cook	  usable entropy is limited by the kernel being built using
2108ed9f007eSKees Cook	  2GB addressing, and that PHYSICAL_ALIGN must be at a
2109ed9f007eSKees Cook	  minimum of 2MB. As a result, only 10 bits of entropy are
2110ed9f007eSKees Cook	  theoretically possible, but the implementations are further
2111ed9f007eSKees Cook	  limited due to memory layouts.
2112e8581e3dSBaoquan He
21136807c846SIngo Molnar	  If unsure, say Y.
2114da2b6fb9SKees Cook
21158ab3820fSKees Cook# Relocation on x86 needs some additional build support
2116845adf72SH. Peter Anvinconfig X86_NEED_RELOCS
2117845adf72SH. Peter Anvin	def_bool y
21188ab3820fSKees Cook	depends on RANDOMIZE_BASE || (X86_32 && RELOCATABLE)
2119845adf72SH. Peter Anvin
2120506f1d07SSam Ravnborgconfig PHYSICAL_ALIGN
2121a0215061SKees Cook	hex "Alignment value to which kernel should be aligned"
21228ab3820fSKees Cook	default "0x200000"
2123a0215061SKees Cook	range 0x2000 0x1000000 if X86_32
2124a0215061SKees Cook	range 0x200000 0x1000000 if X86_64
21258f9ca475SIngo Molnar	---help---
2126506f1d07SSam Ravnborg	  This value puts the alignment restrictions on physical address
2127506f1d07SSam Ravnborg	  where kernel is loaded and run from. Kernel is compiled for an
2128506f1d07SSam Ravnborg	  address which meets above alignment restriction.
2129506f1d07SSam Ravnborg
2130506f1d07SSam Ravnborg	  If bootloader loads the kernel at a non-aligned address and
2131506f1d07SSam Ravnborg	  CONFIG_RELOCATABLE is set, kernel will move itself to nearest
2132506f1d07SSam Ravnborg	  address aligned to above value and run from there.
2133506f1d07SSam Ravnborg
2134506f1d07SSam Ravnborg	  If bootloader loads the kernel at a non-aligned address and
2135506f1d07SSam Ravnborg	  CONFIG_RELOCATABLE is not set, kernel will ignore the run time
2136506f1d07SSam Ravnborg	  load address and decompress itself to the address it has been
2137506f1d07SSam Ravnborg	  compiled for and run from there. The address for which kernel is
2138506f1d07SSam Ravnborg	  compiled already meets above alignment restrictions. Hence the
2139506f1d07SSam Ravnborg	  end result is that kernel runs from a physical address meeting
2140506f1d07SSam Ravnborg	  above alignment restrictions.
2141506f1d07SSam Ravnborg
2142a0215061SKees Cook	  On 32-bit this value must be a multiple of 0x2000. On 64-bit
2143a0215061SKees Cook	  this value must be a multiple of 0x200000.
2144a0215061SKees Cook
2145506f1d07SSam Ravnborg	  Don't change this unless you know what you are doing.
2146506f1d07SSam Ravnborg
21470483e1faSThomas Garnierconfig RANDOMIZE_MEMORY
21480483e1faSThomas Garnier	bool "Randomize the kernel memory sections"
21490483e1faSThomas Garnier	depends on X86_64
21500483e1faSThomas Garnier	depends on RANDOMIZE_BASE
21510483e1faSThomas Garnier	default RANDOMIZE_BASE
21520483e1faSThomas Garnier	---help---
21530483e1faSThomas Garnier	   Randomizes the base virtual address of kernel memory sections
21540483e1faSThomas Garnier	   (physical memory mapping, vmalloc & vmemmap). This security feature
21550483e1faSThomas Garnier	   makes exploits relying on predictable memory locations less reliable.
21560483e1faSThomas Garnier
21570483e1faSThomas Garnier	   The order of allocations remains unchanged. Entropy is generated in
21580483e1faSThomas Garnier	   the same way as RANDOMIZE_BASE. Current implementation in the optimal
21590483e1faSThomas Garnier	   configuration have in average 30,000 different possible virtual
21600483e1faSThomas Garnier	   addresses for each memory section.
21610483e1faSThomas Garnier
21626807c846SIngo Molnar	   If unsure, say Y.
21630483e1faSThomas Garnier
216490397a41SThomas Garnierconfig RANDOMIZE_MEMORY_PHYSICAL_PADDING
216590397a41SThomas Garnier	hex "Physical memory mapping padding" if EXPERT
216690397a41SThomas Garnier	depends on RANDOMIZE_MEMORY
216790397a41SThomas Garnier	default "0xa" if MEMORY_HOTPLUG
216890397a41SThomas Garnier	default "0x0"
216990397a41SThomas Garnier	range 0x1 0x40 if MEMORY_HOTPLUG
217090397a41SThomas Garnier	range 0x0 0x40
217190397a41SThomas Garnier	---help---
217290397a41SThomas Garnier	   Define the padding in terabytes added to the existing physical
217390397a41SThomas Garnier	   memory size during kernel memory randomization. It is useful
217490397a41SThomas Garnier	   for memory hotplug support but reduces the entropy available for
217590397a41SThomas Garnier	   address randomization.
217690397a41SThomas Garnier
217790397a41SThomas Garnier	   If unsure, leave at the default value.
217890397a41SThomas Garnier
2179506f1d07SSam Ravnborgconfig HOTPLUG_CPU
21807c13e6a3SDimitri Sivanich	bool "Support for hot-pluggable CPUs"
218140b31360SStephen Rothwell	depends on SMP
2182506f1d07SSam Ravnborg	---help---
21837c13e6a3SDimitri Sivanich	  Say Y here to allow turning CPUs off and on. CPUs can be
21847c13e6a3SDimitri Sivanich	  controlled through /sys/devices/system/cpu.
21857c13e6a3SDimitri Sivanich	  ( Note: power management support will enable this option
21867c13e6a3SDimitri Sivanich	    automatically on SMP systems. )
21877c13e6a3SDimitri Sivanich	  Say N if you want to disable CPU hotplug.
2188506f1d07SSam Ravnborg
218980aa1dffSFenghua Yuconfig BOOTPARAM_HOTPLUG_CPU0
219080aa1dffSFenghua Yu	bool "Set default setting of cpu0_hotpluggable"
219180aa1dffSFenghua Yu	default n
21922c922cd0SKees Cook	depends on HOTPLUG_CPU
219380aa1dffSFenghua Yu	---help---
219480aa1dffSFenghua Yu	  Set whether default state of cpu0_hotpluggable is on or off.
219580aa1dffSFenghua Yu
219680aa1dffSFenghua Yu	  Say Y here to enable CPU0 hotplug by default. If this switch
219780aa1dffSFenghua Yu	  is turned on, there is no need to give cpu0_hotplug kernel
219880aa1dffSFenghua Yu	  parameter and the CPU0 hotplug feature is enabled by default.
219980aa1dffSFenghua Yu
220080aa1dffSFenghua Yu	  Please note: there are two known CPU0 dependencies if you want
220180aa1dffSFenghua Yu	  to enable the CPU0 hotplug feature either by this switch or by
220280aa1dffSFenghua Yu	  cpu0_hotplug kernel parameter.
220380aa1dffSFenghua Yu
220480aa1dffSFenghua Yu	  First, resume from hibernate or suspend always starts from CPU0.
220580aa1dffSFenghua Yu	  So hibernate and suspend are prevented if CPU0 is offline.
220680aa1dffSFenghua Yu
220780aa1dffSFenghua Yu	  Second dependency is PIC interrupts always go to CPU0. CPU0 can not
220880aa1dffSFenghua Yu	  offline if any interrupt can not migrate out of CPU0. There may
220980aa1dffSFenghua Yu	  be other CPU0 dependencies.
221080aa1dffSFenghua Yu
221180aa1dffSFenghua Yu	  Please make sure the dependencies are under your control before
221280aa1dffSFenghua Yu	  you enable this feature.
221380aa1dffSFenghua Yu
221480aa1dffSFenghua Yu	  Say N if you don't want to enable CPU0 hotplug feature by default.
221580aa1dffSFenghua Yu	  You still can enable the CPU0 hotplug feature at boot by kernel
221680aa1dffSFenghua Yu	  parameter cpu0_hotplug.
221780aa1dffSFenghua Yu
2218a71c8bc5SFenghua Yuconfig DEBUG_HOTPLUG_CPU0
2219a71c8bc5SFenghua Yu	def_bool n
2220a71c8bc5SFenghua Yu	prompt "Debug CPU0 hotplug"
22212c922cd0SKees Cook	depends on HOTPLUG_CPU
2222a71c8bc5SFenghua Yu	---help---
2223a71c8bc5SFenghua Yu	  Enabling this option offlines CPU0 (if CPU0 can be offlined) as
2224a71c8bc5SFenghua Yu	  soon as possible and boots up userspace with CPU0 offlined. User
2225a71c8bc5SFenghua Yu	  can online CPU0 back after boot time.
2226a71c8bc5SFenghua Yu
2227a71c8bc5SFenghua Yu	  To debug CPU0 hotplug, you need to enable CPU0 offline/online
2228a71c8bc5SFenghua Yu	  feature by either turning on CONFIG_BOOTPARAM_HOTPLUG_CPU0 during
2229a71c8bc5SFenghua Yu	  compilation or giving cpu0_hotplug kernel parameter at boot.
2230a71c8bc5SFenghua Yu
2231a71c8bc5SFenghua Yu	  If unsure, say N.
2232a71c8bc5SFenghua Yu
2233506f1d07SSam Ravnborgconfig COMPAT_VDSO
2234b0b49f26SAndy Lutomirski	def_bool n
2235b0b49f26SAndy Lutomirski	prompt "Disable the 32-bit vDSO (needed for glibc 2.3.3)"
2236953fee1dSIngo Molnar	depends on COMPAT_32
22378f9ca475SIngo Molnar	---help---
2238b0b49f26SAndy Lutomirski	  Certain buggy versions of glibc will crash if they are
2239b0b49f26SAndy Lutomirski	  presented with a 32-bit vDSO that is not mapped at the address
2240b0b49f26SAndy Lutomirski	  indicated in its segment table.
2241e84446deSRandy Dunlap
2242b0b49f26SAndy Lutomirski	  The bug was introduced by f866314b89d56845f55e6f365e18b31ec978ec3a
2243b0b49f26SAndy Lutomirski	  and fixed by 3b3ddb4f7db98ec9e912ccdf54d35df4aa30e04a and
2244b0b49f26SAndy Lutomirski	  49ad572a70b8aeb91e57483a11dd1b77e31c4468.  Glibc 2.3.3 is
2245b0b49f26SAndy Lutomirski	  the only released version with the bug, but OpenSUSE 9
2246b0b49f26SAndy Lutomirski	  contains a buggy "glibc 2.3.2".
2247506f1d07SSam Ravnborg
2248b0b49f26SAndy Lutomirski	  The symptom of the bug is that everything crashes on startup, saying:
2249b0b49f26SAndy Lutomirski	  dl_main: Assertion `(void *) ph->p_vaddr == _rtld_local._dl_sysinfo_dso' failed!
2250b0b49f26SAndy Lutomirski
2251b0b49f26SAndy Lutomirski	  Saying Y here changes the default value of the vdso32 boot
2252b0b49f26SAndy Lutomirski	  option from 1 to 0, which turns off the 32-bit vDSO entirely.
2253b0b49f26SAndy Lutomirski	  This works around the glibc bug but hurts performance.
2254b0b49f26SAndy Lutomirski
2255b0b49f26SAndy Lutomirski	  If unsure, say N: if you are compiling your own kernel, you
2256b0b49f26SAndy Lutomirski	  are unlikely to be using a buggy version of glibc.
2257506f1d07SSam Ravnborg
22583dc33bd3SKees Cookchoice
22593dc33bd3SKees Cook	prompt "vsyscall table for legacy applications"
22603dc33bd3SKees Cook	depends on X86_64
22613dc33bd3SKees Cook	default LEGACY_VSYSCALL_EMULATE
22623dc33bd3SKees Cook	help
22633dc33bd3SKees Cook	  Legacy user code that does not know how to find the vDSO expects
22643dc33bd3SKees Cook	  to be able to issue three syscalls by calling fixed addresses in
22653dc33bd3SKees Cook	  kernel space. Since this location is not randomized with ASLR,
22663dc33bd3SKees Cook	  it can be used to assist security vulnerability exploitation.
22673dc33bd3SKees Cook
22683dc33bd3SKees Cook	  This setting can be changed at boot time via the kernel command
22693dc33bd3SKees Cook	  line parameter vsyscall=[native|emulate|none].
22703dc33bd3SKees Cook
22713dc33bd3SKees Cook	  On a system with recent enough glibc (2.14 or newer) and no
22723dc33bd3SKees Cook	  static binaries, you can say None without a performance penalty
22733dc33bd3SKees Cook	  to improve security.
22743dc33bd3SKees Cook
22753dc33bd3SKees Cook	  If unsure, select "Emulate".
22763dc33bd3SKees Cook
22773dc33bd3SKees Cook	config LEGACY_VSYSCALL_NATIVE
22783dc33bd3SKees Cook		bool "Native"
22793dc33bd3SKees Cook		help
22803dc33bd3SKees Cook		  Actual executable code is located in the fixed vsyscall
22813dc33bd3SKees Cook		  address mapping, implementing time() efficiently. Since
22823dc33bd3SKees Cook		  this makes the mapping executable, it can be used during
22833dc33bd3SKees Cook		  security vulnerability exploitation (traditionally as
22843dc33bd3SKees Cook		  ROP gadgets). This configuration is not recommended.
22853dc33bd3SKees Cook
22863dc33bd3SKees Cook	config LEGACY_VSYSCALL_EMULATE
22873dc33bd3SKees Cook		bool "Emulate"
22883dc33bd3SKees Cook		help
22893dc33bd3SKees Cook		  The kernel traps and emulates calls into the fixed
22903dc33bd3SKees Cook		  vsyscall address mapping. This makes the mapping
22913dc33bd3SKees Cook		  non-executable, but it still contains known contents,
22923dc33bd3SKees Cook		  which could be used in certain rare security vulnerability
22933dc33bd3SKees Cook		  exploits. This configuration is recommended when userspace
22943dc33bd3SKees Cook		  still uses the vsyscall area.
22953dc33bd3SKees Cook
22963dc33bd3SKees Cook	config LEGACY_VSYSCALL_NONE
22973dc33bd3SKees Cook		bool "None"
22983dc33bd3SKees Cook		help
22993dc33bd3SKees Cook		  There will be no vsyscall mapping at all. This will
23003dc33bd3SKees Cook		  eliminate any risk of ASLR bypass due to the vsyscall
23013dc33bd3SKees Cook		  fixed address mapping. Attempts to use the vsyscalls
23023dc33bd3SKees Cook		  will be reported to dmesg, so that either old or
23033dc33bd3SKees Cook		  malicious userspace programs can be identified.
23043dc33bd3SKees Cook
23053dc33bd3SKees Cookendchoice
23063dc33bd3SKees Cook
2307516cbf37STim Birdconfig CMDLINE_BOOL
2308516cbf37STim Bird	bool "Built-in kernel command line"
23098f9ca475SIngo Molnar	---help---
2310516cbf37STim Bird	  Allow for specifying boot arguments to the kernel at
2311516cbf37STim Bird	  build time.  On some systems (e.g. embedded ones), it is
2312516cbf37STim Bird	  necessary or convenient to provide some or all of the
2313516cbf37STim Bird	  kernel boot arguments with the kernel itself (that is,
2314516cbf37STim Bird	  to not rely on the boot loader to provide them.)
2315516cbf37STim Bird
2316516cbf37STim Bird	  To compile command line arguments into the kernel,
2317516cbf37STim Bird	  set this option to 'Y', then fill in the
231869711ca1SSébastien Hinderer	  boot arguments in CONFIG_CMDLINE.
2319516cbf37STim Bird
2320516cbf37STim Bird	  Systems with fully functional boot loaders (i.e. non-embedded)
2321516cbf37STim Bird	  should leave this option set to 'N'.
2322516cbf37STim Bird
2323516cbf37STim Birdconfig CMDLINE
2324516cbf37STim Bird	string "Built-in kernel command string"
2325516cbf37STim Bird	depends on CMDLINE_BOOL
2326516cbf37STim Bird	default ""
23278f9ca475SIngo Molnar	---help---
2328516cbf37STim Bird	  Enter arguments here that should be compiled into the kernel
2329516cbf37STim Bird	  image and used at boot time.  If the boot loader provides a
2330516cbf37STim Bird	  command line at boot time, it is appended to this string to
2331516cbf37STim Bird	  form the full kernel command line, when the system boots.
2332516cbf37STim Bird
2333516cbf37STim Bird	  However, you can use the CONFIG_CMDLINE_OVERRIDE option to
2334516cbf37STim Bird	  change this behavior.
2335516cbf37STim Bird
2336516cbf37STim Bird	  In most cases, the command line (whether built-in or provided
2337516cbf37STim Bird	  by the boot loader) should specify the device for the root
2338516cbf37STim Bird	  file system.
2339516cbf37STim Bird
2340516cbf37STim Birdconfig CMDLINE_OVERRIDE
2341516cbf37STim Bird	bool "Built-in command line overrides boot loader arguments"
2342516cbf37STim Bird	depends on CMDLINE_BOOL
23438f9ca475SIngo Molnar	---help---
2344516cbf37STim Bird	  Set this option to 'Y' to have the kernel ignore the boot loader
2345516cbf37STim Bird	  command line, and use ONLY the built-in command line.
2346516cbf37STim Bird
2347516cbf37STim Bird	  This is used to work around broken boot loaders.  This should
2348516cbf37STim Bird	  be set to 'N' under normal conditions.
2349516cbf37STim Bird
2350a5b9e5a2SAndy Lutomirskiconfig MODIFY_LDT_SYSCALL
2351a5b9e5a2SAndy Lutomirski	bool "Enable the LDT (local descriptor table)" if EXPERT
2352a5b9e5a2SAndy Lutomirski	default y
2353a5b9e5a2SAndy Lutomirski	---help---
2354a5b9e5a2SAndy Lutomirski	  Linux can allow user programs to install a per-process x86
2355a5b9e5a2SAndy Lutomirski	  Local Descriptor Table (LDT) using the modify_ldt(2) system
2356a5b9e5a2SAndy Lutomirski	  call.  This is required to run 16-bit or segmented code such as
2357a5b9e5a2SAndy Lutomirski	  DOSEMU or some Wine programs.  It is also used by some very old
2358a5b9e5a2SAndy Lutomirski	  threading libraries.
2359a5b9e5a2SAndy Lutomirski
2360a5b9e5a2SAndy Lutomirski	  Enabling this feature adds a small amount of overhead to
2361a5b9e5a2SAndy Lutomirski	  context switches and increases the low-level kernel attack
2362a5b9e5a2SAndy Lutomirski	  surface.  Disabling it removes the modify_ldt(2) system call.
2363a5b9e5a2SAndy Lutomirski
2364a5b9e5a2SAndy Lutomirski	  Saying 'N' here may make sense for embedded or server kernels.
2365a5b9e5a2SAndy Lutomirski
2366b700e7f0SSeth Jenningssource "kernel/livepatch/Kconfig"
2367b700e7f0SSeth Jennings
2368506f1d07SSam Ravnborgendmenu
2369506f1d07SSam Ravnborg
23703072e413SMichal Hockoconfig ARCH_HAS_ADD_PAGES
23713072e413SMichal Hocko	def_bool y
23723072e413SMichal Hocko	depends on X86_64 && ARCH_ENABLE_MEMORY_HOTPLUG
23733072e413SMichal Hocko
2374506f1d07SSam Ravnborgconfig ARCH_ENABLE_MEMORY_HOTPLUG
2375506f1d07SSam Ravnborg	def_bool y
2376506f1d07SSam Ravnborg	depends on X86_64 || (X86_32 && HIGHMEM)
2377506f1d07SSam Ravnborg
237835551053SGary Hadeconfig ARCH_ENABLE_MEMORY_HOTREMOVE
237935551053SGary Hade	def_bool y
238035551053SGary Hade	depends on MEMORY_HOTPLUG
238135551053SGary Hade
2382e534c7c5SLee Schermerhornconfig USE_PERCPU_NUMA_NODE_ID
2383645a7919STejun Heo	def_bool y
2384e534c7c5SLee Schermerhorn	depends on NUMA
2385e534c7c5SLee Schermerhorn
23869491846fSKirill A. Shutemovconfig ARCH_ENABLE_SPLIT_PMD_PTLOCK
23879491846fSKirill A. Shutemov	def_bool y
23889491846fSKirill A. Shutemov	depends on X86_64 || X86_PAE
23899491846fSKirill A. Shutemov
2390c177c81eSNaoya Horiguchiconfig ARCH_ENABLE_HUGEPAGE_MIGRATION
2391c177c81eSNaoya Horiguchi	def_bool y
2392c177c81eSNaoya Horiguchi	depends on X86_64 && HUGETLB_PAGE && MIGRATION
2393c177c81eSNaoya Horiguchi
23949c670ea3SNaoya Horiguchiconfig ARCH_ENABLE_THP_MIGRATION
23959c670ea3SNaoya Horiguchi	def_bool y
23969c670ea3SNaoya Horiguchi	depends on X86_64 && TRANSPARENT_HUGEPAGE
23979c670ea3SNaoya Horiguchi
2398da85f865SBjorn Helgaasmenu "Power management and ACPI options"
2399e279b6c1SSam Ravnborg
2400e279b6c1SSam Ravnborgconfig ARCH_HIBERNATION_HEADER
24013c2362e6SHarvey Harrison	def_bool y
2402e279b6c1SSam Ravnborg	depends on X86_64 && HIBERNATION
2403e279b6c1SSam Ravnborg
2404e279b6c1SSam Ravnborgsource "kernel/power/Kconfig"
2405e279b6c1SSam Ravnborg
2406e279b6c1SSam Ravnborgsource "drivers/acpi/Kconfig"
2407e279b6c1SSam Ravnborg
2408efafc8b2SFeng Tangsource "drivers/sfi/Kconfig"
2409efafc8b2SFeng Tang
2410a6b68076SAndi Kleenconfig X86_APM_BOOT
24116fc108a0SJan Beulich	def_bool y
2412282e5aabSPaul Bolle	depends on APM
2413a6b68076SAndi Kleen
2414e279b6c1SSam Ravnborgmenuconfig APM
2415e279b6c1SSam Ravnborg	tristate "APM (Advanced Power Management) BIOS support"
2416efefa6f6SIngo Molnar	depends on X86_32 && PM_SLEEP
2417e279b6c1SSam Ravnborg	---help---
2418e279b6c1SSam Ravnborg	  APM is a BIOS specification for saving power using several different
2419e279b6c1SSam Ravnborg	  techniques. This is mostly useful for battery powered laptops with
2420e279b6c1SSam Ravnborg	  APM compliant BIOSes. If you say Y here, the system time will be
2421e279b6c1SSam Ravnborg	  reset after a RESUME operation, the /proc/apm device will provide
2422e279b6c1SSam Ravnborg	  battery status information, and user-space programs will receive
2423e279b6c1SSam Ravnborg	  notification of APM "events" (e.g. battery status change).
2424e279b6c1SSam Ravnborg
2425e279b6c1SSam Ravnborg	  If you select "Y" here, you can disable actual use of the APM
2426e279b6c1SSam Ravnborg	  BIOS by passing the "apm=off" option to the kernel at boot time.
2427e279b6c1SSam Ravnborg
2428e279b6c1SSam Ravnborg	  Note that the APM support is almost completely disabled for
2429e279b6c1SSam Ravnborg	  machines with more than one CPU.
2430e279b6c1SSam Ravnborg
2431e279b6c1SSam Ravnborg	  In order to use APM, you will need supporting software. For location
24322dc98fd3SMichael Witten	  and more information, read <file:Documentation/power/apm-acpi.txt>
24332dc98fd3SMichael Witten	  and the Battery Powered Linux mini-HOWTO, available from
2434e279b6c1SSam Ravnborg	  <http://www.tldp.org/docs.html#howto>.
2435e279b6c1SSam Ravnborg
2436e279b6c1SSam Ravnborg	  This driver does not spin down disk drives (see the hdparm(8)
2437e279b6c1SSam Ravnborg	  manpage ("man 8 hdparm") for that), and it doesn't turn off
2438e279b6c1SSam Ravnborg	  VESA-compliant "green" monitors.
2439e279b6c1SSam Ravnborg
2440e279b6c1SSam Ravnborg	  This driver does not support the TI 4000M TravelMate and the ACER
2441e279b6c1SSam Ravnborg	  486/DX4/75 because they don't have compliant BIOSes. Many "green"
2442e279b6c1SSam Ravnborg	  desktop machines also don't have compliant BIOSes, and this driver
2443e279b6c1SSam Ravnborg	  may cause those machines to panic during the boot phase.
2444e279b6c1SSam Ravnborg
2445e279b6c1SSam Ravnborg	  Generally, if you don't have a battery in your machine, there isn't
2446e279b6c1SSam Ravnborg	  much point in using this driver and you should say N. If you get
2447e279b6c1SSam Ravnborg	  random kernel OOPSes or reboots that don't seem to be related to
2448e279b6c1SSam Ravnborg	  anything, try disabling/enabling this option (or disabling/enabling
2449e279b6c1SSam Ravnborg	  APM in your BIOS).
2450e279b6c1SSam Ravnborg
2451e279b6c1SSam Ravnborg	  Some other things you should try when experiencing seemingly random,
2452e279b6c1SSam Ravnborg	  "weird" problems:
2453e279b6c1SSam Ravnborg
2454e279b6c1SSam Ravnborg	  1) make sure that you have enough swap space and that it is
2455e279b6c1SSam Ravnborg	  enabled.
2456e279b6c1SSam Ravnborg	  2) pass the "no-hlt" option to the kernel
2457e279b6c1SSam Ravnborg	  3) switch on floating point emulation in the kernel and pass
2458e279b6c1SSam Ravnborg	  the "no387" option to the kernel
2459e279b6c1SSam Ravnborg	  4) pass the "floppy=nodma" option to the kernel
2460e279b6c1SSam Ravnborg	  5) pass the "mem=4M" option to the kernel (thereby disabling
2461e279b6c1SSam Ravnborg	  all but the first 4 MB of RAM)
2462e279b6c1SSam Ravnborg	  6) make sure that the CPU is not over clocked.
2463e279b6c1SSam Ravnborg	  7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/>
2464e279b6c1SSam Ravnborg	  8) disable the cache from your BIOS settings
2465e279b6c1SSam Ravnborg	  9) install a fan for the video card or exchange video RAM
2466e279b6c1SSam Ravnborg	  10) install a better fan for the CPU
2467e279b6c1SSam Ravnborg	  11) exchange RAM chips
2468e279b6c1SSam Ravnborg	  12) exchange the motherboard.
2469e279b6c1SSam Ravnborg
2470e279b6c1SSam Ravnborg	  To compile this driver as a module, choose M here: the
2471e279b6c1SSam Ravnborg	  module will be called apm.
2472e279b6c1SSam Ravnborg
2473e279b6c1SSam Ravnborgif APM
2474e279b6c1SSam Ravnborg
2475e279b6c1SSam Ravnborgconfig APM_IGNORE_USER_SUSPEND
2476e279b6c1SSam Ravnborg	bool "Ignore USER SUSPEND"
24778f9ca475SIngo Molnar	---help---
2478e279b6c1SSam Ravnborg	  This option will ignore USER SUSPEND requests. On machines with a
2479e279b6c1SSam Ravnborg	  compliant APM BIOS, you want to say N. However, on the NEC Versa M
2480e279b6c1SSam Ravnborg	  series notebooks, it is necessary to say Y because of a BIOS bug.
2481e279b6c1SSam Ravnborg
2482e279b6c1SSam Ravnborgconfig APM_DO_ENABLE
2483e279b6c1SSam Ravnborg	bool "Enable PM at boot time"
2484e279b6c1SSam Ravnborg	---help---
2485e279b6c1SSam Ravnborg	  Enable APM features at boot time. From page 36 of the APM BIOS
2486e279b6c1SSam Ravnborg	  specification: "When disabled, the APM BIOS does not automatically
2487e279b6c1SSam Ravnborg	  power manage devices, enter the Standby State, enter the Suspend
2488e279b6c1SSam Ravnborg	  State, or take power saving steps in response to CPU Idle calls."
2489e279b6c1SSam Ravnborg	  This driver will make CPU Idle calls when Linux is idle (unless this
2490e279b6c1SSam Ravnborg	  feature is turned off -- see "Do CPU IDLE calls", below). This
2491e279b6c1SSam Ravnborg	  should always save battery power, but more complicated APM features
2492e279b6c1SSam Ravnborg	  will be dependent on your BIOS implementation. You may need to turn
2493e279b6c1SSam Ravnborg	  this option off if your computer hangs at boot time when using APM
2494e279b6c1SSam Ravnborg	  support, or if it beeps continuously instead of suspending. Turn
2495e279b6c1SSam Ravnborg	  this off if you have a NEC UltraLite Versa 33/C or a Toshiba
2496e279b6c1SSam Ravnborg	  T400CDT. This is off by default since most machines do fine without
2497e279b6c1SSam Ravnborg	  this feature.
2498e279b6c1SSam Ravnborg
2499e279b6c1SSam Ravnborgconfig APM_CPU_IDLE
2500dd8af076SLen Brown	depends on CPU_IDLE
2501e279b6c1SSam Ravnborg	bool "Make CPU Idle calls when idle"
25028f9ca475SIngo Molnar	---help---
2503e279b6c1SSam Ravnborg	  Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop.
2504e279b6c1SSam Ravnborg	  On some machines, this can activate improved power savings, such as
2505e279b6c1SSam Ravnborg	  a slowed CPU clock rate, when the machine is idle. These idle calls
2506e279b6c1SSam Ravnborg	  are made after the idle loop has run for some length of time (e.g.,
2507e279b6c1SSam Ravnborg	  333 mS). On some machines, this will cause a hang at boot time or
2508e279b6c1SSam Ravnborg	  whenever the CPU becomes idle. (On machines with more than one CPU,
2509e279b6c1SSam Ravnborg	  this option does nothing.)
2510e279b6c1SSam Ravnborg
2511e279b6c1SSam Ravnborgconfig APM_DISPLAY_BLANK
2512e279b6c1SSam Ravnborg	bool "Enable console blanking using APM"
25138f9ca475SIngo Molnar	---help---
2514e279b6c1SSam Ravnborg	  Enable console blanking using the APM. Some laptops can use this to
2515e279b6c1SSam Ravnborg	  turn off the LCD backlight when the screen blanker of the Linux
2516e279b6c1SSam Ravnborg	  virtual console blanks the screen. Note that this is only used by
2517e279b6c1SSam Ravnborg	  the virtual console screen blanker, and won't turn off the backlight
2518e279b6c1SSam Ravnborg	  when using the X Window system. This also doesn't have anything to
2519e279b6c1SSam Ravnborg	  do with your VESA-compliant power-saving monitor. Further, this
2520e279b6c1SSam Ravnborg	  option doesn't work for all laptops -- it might not turn off your
2521e279b6c1SSam Ravnborg	  backlight at all, or it might print a lot of errors to the console,
2522e279b6c1SSam Ravnborg	  especially if you are using gpm.
2523e279b6c1SSam Ravnborg
2524e279b6c1SSam Ravnborgconfig APM_ALLOW_INTS
2525e279b6c1SSam Ravnborg	bool "Allow interrupts during APM BIOS calls"
25268f9ca475SIngo Molnar	---help---
2527e279b6c1SSam Ravnborg	  Normally we disable external interrupts while we are making calls to
2528e279b6c1SSam Ravnborg	  the APM BIOS as a measure to lessen the effects of a badly behaving
2529e279b6c1SSam Ravnborg	  BIOS implementation.  The BIOS should reenable interrupts if it
2530e279b6c1SSam Ravnborg	  needs to.  Unfortunately, some BIOSes do not -- especially those in
2531e279b6c1SSam Ravnborg	  many of the newer IBM Thinkpads.  If you experience hangs when you
2532e279b6c1SSam Ravnborg	  suspend, try setting this to Y.  Otherwise, say N.
2533e279b6c1SSam Ravnborg
2534e279b6c1SSam Ravnborgendif # APM
2535e279b6c1SSam Ravnborg
2536bb0a56ecSDave Jonessource "drivers/cpufreq/Kconfig"
2537e279b6c1SSam Ravnborg
2538e279b6c1SSam Ravnborgsource "drivers/cpuidle/Kconfig"
2539e279b6c1SSam Ravnborg
254027471fdbSAndy Henroidsource "drivers/idle/Kconfig"
254127471fdbSAndy Henroid
2542e279b6c1SSam Ravnborgendmenu
2543e279b6c1SSam Ravnborg
2544e279b6c1SSam Ravnborg
2545e279b6c1SSam Ravnborgmenu "Bus options (PCI etc.)"
2546e279b6c1SSam Ravnborg
2547e279b6c1SSam Ravnborgconfig PCI
25481ac97018SIngo Molnar	bool "PCI support"
25491c858087SAdrian Bunk	default y
25508f9ca475SIngo Molnar	---help---
2551e279b6c1SSam Ravnborg	  Find out whether you have a PCI motherboard. PCI is the name of a
2552e279b6c1SSam Ravnborg	  bus system, i.e. the way the CPU talks to the other stuff inside
2553e279b6c1SSam Ravnborg	  your box. Other bus systems are ISA, EISA, MicroChannel (MCA) or
2554e279b6c1SSam Ravnborg	  VESA. If you have PCI, say Y, otherwise N.
2555e279b6c1SSam Ravnborg
2556e279b6c1SSam Ravnborgchoice
2557e279b6c1SSam Ravnborg	prompt "PCI access mode"
2558efefa6f6SIngo Molnar	depends on X86_32 && PCI
2559e279b6c1SSam Ravnborg	default PCI_GOANY
2560e279b6c1SSam Ravnborg	---help---
2561e279b6c1SSam Ravnborg	  On PCI systems, the BIOS can be used to detect the PCI devices and
2562e279b6c1SSam Ravnborg	  determine their configuration. However, some old PCI motherboards
2563e279b6c1SSam Ravnborg	  have BIOS bugs and may crash if this is done. Also, some embedded
2564e279b6c1SSam Ravnborg	  PCI-based systems don't have any BIOS at all. Linux can also try to
2565e279b6c1SSam Ravnborg	  detect the PCI hardware directly without using the BIOS.
2566e279b6c1SSam Ravnborg
2567e279b6c1SSam Ravnborg	  With this option, you can specify how Linux should detect the
2568e279b6c1SSam Ravnborg	  PCI devices. If you choose "BIOS", the BIOS will be used,
2569e279b6c1SSam Ravnborg	  if you choose "Direct", the BIOS won't be used, and if you
2570e279b6c1SSam Ravnborg	  choose "MMConfig", then PCI Express MMCONFIG will be used.
2571e279b6c1SSam Ravnborg	  If you choose "Any", the kernel will try MMCONFIG, then the
2572e279b6c1SSam Ravnborg	  direct access method and falls back to the BIOS if that doesn't
2573e279b6c1SSam Ravnborg	  work. If unsure, go with the default, which is "Any".
2574e279b6c1SSam Ravnborg
2575e279b6c1SSam Ravnborgconfig PCI_GOBIOS
2576e279b6c1SSam Ravnborg	bool "BIOS"
2577e279b6c1SSam Ravnborg
2578e279b6c1SSam Ravnborgconfig PCI_GOMMCONFIG
2579e279b6c1SSam Ravnborg	bool "MMConfig"
2580e279b6c1SSam Ravnborg
2581e279b6c1SSam Ravnborgconfig PCI_GODIRECT
2582e279b6c1SSam Ravnborg	bool "Direct"
2583e279b6c1SSam Ravnborg
25843ef0e1f8SAndres Salomonconfig PCI_GOOLPC
258576fb6570SDaniel Drake	bool "OLPC XO-1"
25863ef0e1f8SAndres Salomon	depends on OLPC
25873ef0e1f8SAndres Salomon
25882bdd1b03SAndres Salomonconfig PCI_GOANY
25892bdd1b03SAndres Salomon	bool "Any"
25902bdd1b03SAndres Salomon
2591e279b6c1SSam Ravnborgendchoice
2592e279b6c1SSam Ravnborg
2593e279b6c1SSam Ravnborgconfig PCI_BIOS
25943c2362e6SHarvey Harrison	def_bool y
2595efefa6f6SIngo Molnar	depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY)
2596e279b6c1SSam Ravnborg
2597e279b6c1SSam Ravnborg# x86-64 doesn't support PCI BIOS access from long mode so always go direct.
2598e279b6c1SSam Ravnborgconfig PCI_DIRECT
25993c2362e6SHarvey Harrison	def_bool y
26000aba496fSShaohua Li	depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC || PCI_GOMMCONFIG))
2601e279b6c1SSam Ravnborg
2602e279b6c1SSam Ravnborgconfig PCI_MMCONFIG
26033c2362e6SHarvey Harrison	def_bool y
26045f0db7a2SFeng Tang	depends on X86_32 && PCI && (ACPI || SFI) && (PCI_GOMMCONFIG || PCI_GOANY)
2605e279b6c1SSam Ravnborg
26063ef0e1f8SAndres Salomonconfig PCI_OLPC
26072bdd1b03SAndres Salomon	def_bool y
26082bdd1b03SAndres Salomon	depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY)
26093ef0e1f8SAndres Salomon
2610b5401a96SAlex Nixonconfig PCI_XEN
2611b5401a96SAlex Nixon	def_bool y
2612b5401a96SAlex Nixon	depends on PCI && XEN
2613b5401a96SAlex Nixon	select SWIOTLB_XEN
2614b5401a96SAlex Nixon
2615e279b6c1SSam Ravnborgconfig PCI_DOMAINS
26163c2362e6SHarvey Harrison	def_bool y
2617e279b6c1SSam Ravnborg	depends on PCI
2618e279b6c1SSam Ravnborg
2619e279b6c1SSam Ravnborgconfig PCI_MMCONFIG
2620e279b6c1SSam Ravnborg	bool "Support mmconfig PCI config space access"
2621e279b6c1SSam Ravnborg	depends on X86_64 && PCI && ACPI
2622e279b6c1SSam Ravnborg
26233f6ea84aSIra W. Snyderconfig PCI_CNB20LE_QUIRK
26246a108a14SDavid Rientjes	bool "Read CNB20LE Host Bridge Windows" if EXPERT
26256ea30386SKees Cook	depends on PCI
26263f6ea84aSIra W. Snyder	help
26273f6ea84aSIra W. Snyder	  Read the PCI windows out of the CNB20LE host bridge. This allows
26283f6ea84aSIra W. Snyder	  PCI hotplug to work on systems with the CNB20LE chipset which do
26293f6ea84aSIra W. Snyder	  not have ACPI.
26303f6ea84aSIra W. Snyder
263164a5fed6SBjorn Helgaas	  There's no public spec for this chipset, and this functionality
263264a5fed6SBjorn Helgaas	  is known to be incomplete.
263364a5fed6SBjorn Helgaas
263464a5fed6SBjorn Helgaas	  You should say N unless you know you need this.
263564a5fed6SBjorn Helgaas
2636e279b6c1SSam Ravnborgsource "drivers/pci/Kconfig"
2637e279b6c1SSam Ravnborg
26383a495511SWilliam Breathitt Grayconfig ISA_BUS
26393a495511SWilliam Breathitt Gray	bool "ISA-style bus support on modern systems" if EXPERT
26403a495511SWilliam Breathitt Gray	select ISA_BUS_API
26413a495511SWilliam Breathitt Gray	help
26423a495511SWilliam Breathitt Gray	  Enables ISA-style drivers on modern systems. This is necessary to
26433a495511SWilliam Breathitt Gray	  support PC/104 devices on X86_64 platforms.
26443a495511SWilliam Breathitt Gray
26453a495511SWilliam Breathitt Gray	  If unsure, say N.
26463a495511SWilliam Breathitt Gray
26471c00f016SDavid Rientjes# x86_64 have no ISA slots, but can have ISA-style DMA.
2648e279b6c1SSam Ravnborgconfig ISA_DMA_API
26491c00f016SDavid Rientjes	bool "ISA-style DMA support" if (X86_64 && EXPERT)
26501c00f016SDavid Rientjes	default y
26511c00f016SDavid Rientjes	help
26521c00f016SDavid Rientjes	  Enables ISA-style DMA support for devices requiring such controllers.
26531c00f016SDavid Rientjes	  If unsure, say Y.
2654e279b6c1SSam Ravnborg
265551e68d05SLinus Torvaldsif X86_32
265651e68d05SLinus Torvalds
2657e279b6c1SSam Ravnborgconfig ISA
2658e279b6c1SSam Ravnborg	bool "ISA support"
26598f9ca475SIngo Molnar	---help---
2660e279b6c1SSam Ravnborg	  Find out whether you have ISA slots on your motherboard.  ISA is the
2661e279b6c1SSam Ravnborg	  name of a bus system, i.e. the way the CPU talks to the other stuff
2662e279b6c1SSam Ravnborg	  inside your box.  Other bus systems are PCI, EISA, MicroChannel
2663e279b6c1SSam Ravnborg	  (MCA) or VESA.  ISA is an older system, now being displaced by PCI;
2664e279b6c1SSam Ravnborg	  newer boards don't support it.  If you have ISA, say Y, otherwise N.
2665e279b6c1SSam Ravnborg
2666e279b6c1SSam Ravnborgconfig EISA
2667e279b6c1SSam Ravnborg	bool "EISA support"
2668e279b6c1SSam Ravnborg	depends on ISA
2669e279b6c1SSam Ravnborg	---help---
2670e279b6c1SSam Ravnborg	  The Extended Industry Standard Architecture (EISA) bus was
2671e279b6c1SSam Ravnborg	  developed as an open alternative to the IBM MicroChannel bus.
2672e279b6c1SSam Ravnborg
2673e279b6c1SSam Ravnborg	  The EISA bus provided some of the features of the IBM MicroChannel
2674e279b6c1SSam Ravnborg	  bus while maintaining backward compatibility with cards made for
2675e279b6c1SSam Ravnborg	  the older ISA bus.  The EISA bus saw limited use between 1988 and
2676e279b6c1SSam Ravnborg	  1995 when it was made obsolete by the PCI bus.
2677e279b6c1SSam Ravnborg
2678e279b6c1SSam Ravnborg	  Say Y here if you are building a kernel for an EISA-based machine.
2679e279b6c1SSam Ravnborg
2680e279b6c1SSam Ravnborg	  Otherwise, say N.
2681e279b6c1SSam Ravnborg
2682e279b6c1SSam Ravnborgsource "drivers/eisa/Kconfig"
2683e279b6c1SSam Ravnborg
2684e279b6c1SSam Ravnborgconfig SCx200
2685e279b6c1SSam Ravnborg	tristate "NatSemi SCx200 support"
26868f9ca475SIngo Molnar	---help---
2687e279b6c1SSam Ravnborg	  This provides basic support for National Semiconductor's
2688e279b6c1SSam Ravnborg	  (now AMD's) Geode processors.  The driver probes for the
2689e279b6c1SSam Ravnborg	  PCI-IDs of several on-chip devices, so its a good dependency
2690e279b6c1SSam Ravnborg	  for other scx200_* drivers.
2691e279b6c1SSam Ravnborg
2692e279b6c1SSam Ravnborg	  If compiled as a module, the driver is named scx200.
2693e279b6c1SSam Ravnborg
2694e279b6c1SSam Ravnborgconfig SCx200HR_TIMER
2695e279b6c1SSam Ravnborg	tristate "NatSemi SCx200 27MHz High-Resolution Timer Support"
2696592913ecSJohn Stultz	depends on SCx200
2697e279b6c1SSam Ravnborg	default y
26988f9ca475SIngo Molnar	---help---
2699e279b6c1SSam Ravnborg	  This driver provides a clocksource built upon the on-chip
2700e279b6c1SSam Ravnborg	  27MHz high-resolution timer.  Its also a workaround for
2701e279b6c1SSam Ravnborg	  NSC Geode SC-1100's buggy TSC, which loses time when the
2702e279b6c1SSam Ravnborg	  processor goes idle (as is done by the scheduler).  The
2703e279b6c1SSam Ravnborg	  other workaround is idle=poll boot option.
2704e279b6c1SSam Ravnborg
27053ef0e1f8SAndres Salomonconfig OLPC
27063ef0e1f8SAndres Salomon	bool "One Laptop Per Child support"
270754008979SThomas Gleixner	depends on !X86_PAE
27083c554946SAndres Salomon	select GPIOLIB
2709dc3119e7SThomas Gleixner	select OF
271045bb1674SDaniel Drake	select OF_PROMTREE
2711b4e51854SGrant Likely	select IRQ_DOMAIN
27128f9ca475SIngo Molnar	---help---
27133ef0e1f8SAndres Salomon	  Add support for detecting the unique features of the OLPC
27143ef0e1f8SAndres Salomon	  XO hardware.
27153ef0e1f8SAndres Salomon
2716a3128588SDaniel Drakeconfig OLPC_XO1_PM
2717a3128588SDaniel Drake	bool "OLPC XO-1 Power Management"
271897c4cb71SDaniel Drake	depends on OLPC && MFD_CS5535 && PM_SLEEP
2719a3128588SDaniel Drake	select MFD_CORE
2720bf1ebf00SDaniel Drake	---help---
272197c4cb71SDaniel Drake	  Add support for poweroff and suspend of the OLPC XO-1 laptop.
2722bf1ebf00SDaniel Drake
2723cfee9597SDaniel Drakeconfig OLPC_XO1_RTC
2724cfee9597SDaniel Drake	bool "OLPC XO-1 Real Time Clock"
2725cfee9597SDaniel Drake	depends on OLPC_XO1_PM && RTC_DRV_CMOS
2726cfee9597SDaniel Drake	---help---
2727cfee9597SDaniel Drake	  Add support for the XO-1 real time clock, which can be used as a
2728cfee9597SDaniel Drake	  programmable wakeup source.
2729cfee9597SDaniel Drake
27307feda8e9SDaniel Drakeconfig OLPC_XO1_SCI
27317feda8e9SDaniel Drake	bool "OLPC XO-1 SCI extras"
2732d8d01a63SDaniel Drake	depends on OLPC && OLPC_XO1_PM
2733ed8e47feSRandy Dunlap	depends on INPUT=y
2734d8d01a63SDaniel Drake	select POWER_SUPPLY
27357feda8e9SDaniel Drake	select GPIO_CS5535
27367feda8e9SDaniel Drake	select MFD_CORE
27377feda8e9SDaniel Drake	---help---
27387feda8e9SDaniel Drake	  Add support for SCI-based features of the OLPC XO-1 laptop:
27397bc74b3dSDaniel Drake	   - EC-driven system wakeups
27407feda8e9SDaniel Drake	   - Power button
27417bc74b3dSDaniel Drake	   - Ebook switch
27422cf2baeaSDaniel Drake	   - Lid switch
2743e1040ac6SDaniel Drake	   - AC adapter status updates
2744e1040ac6SDaniel Drake	   - Battery status updates
27457feda8e9SDaniel Drake
2746a0f30f59SDaniel Drakeconfig OLPC_XO15_SCI
2747a0f30f59SDaniel Drake	bool "OLPC XO-1.5 SCI extras"
2748d8d01a63SDaniel Drake	depends on OLPC && ACPI
2749d8d01a63SDaniel Drake	select POWER_SUPPLY
2750a0f30f59SDaniel Drake	---help---
2751a0f30f59SDaniel Drake	  Add support for SCI-based features of the OLPC XO-1.5 laptop:
2752a0f30f59SDaniel Drake	   - EC-driven system wakeups
2753a0f30f59SDaniel Drake	   - AC adapter status updates
2754a0f30f59SDaniel Drake	   - Battery status updates
2755e279b6c1SSam Ravnborg
2756d4f3e350SEd Wildgooseconfig ALIX
2757d4f3e350SEd Wildgoose	bool "PCEngines ALIX System Support (LED setup)"
2758d4f3e350SEd Wildgoose	select GPIOLIB
2759d4f3e350SEd Wildgoose	---help---
2760d4f3e350SEd Wildgoose	  This option enables system support for the PCEngines ALIX.
2761d4f3e350SEd Wildgoose	  At present this just sets up LEDs for GPIO control on
2762d4f3e350SEd Wildgoose	  ALIX2/3/6 boards.  However, other system specific setup should
2763d4f3e350SEd Wildgoose	  get added here.
2764d4f3e350SEd Wildgoose
2765d4f3e350SEd Wildgoose	  Note: You must still enable the drivers for GPIO and LED support
2766d4f3e350SEd Wildgoose	  (GPIO_CS5535 & LEDS_GPIO) to actually use the LEDs
2767d4f3e350SEd Wildgoose
2768d4f3e350SEd Wildgoose	  Note: You have to set alix.force=1 for boards with Award BIOS.
2769d4f3e350SEd Wildgoose
2770da4e3302SPhilip Prindevilleconfig NET5501
2771da4e3302SPhilip Prindeville	bool "Soekris Engineering net5501 System Support (LEDS, GPIO, etc)"
2772da4e3302SPhilip Prindeville	select GPIOLIB
2773da4e3302SPhilip Prindeville	---help---
2774da4e3302SPhilip Prindeville	  This option enables system support for the Soekris Engineering net5501.
2775da4e3302SPhilip Prindeville
27763197059aSPhilip A. Prindevilleconfig GEOS
27773197059aSPhilip A. Prindeville	bool "Traverse Technologies GEOS System Support (LEDS, GPIO, etc)"
27783197059aSPhilip A. Prindeville	select GPIOLIB
27793197059aSPhilip A. Prindeville	depends on DMI
27803197059aSPhilip A. Prindeville	---help---
27813197059aSPhilip A. Prindeville	  This option enables system support for the Traverse Technologies GEOS.
27823197059aSPhilip A. Prindeville
27837d029125SVivien Didelotconfig TS5500
27847d029125SVivien Didelot	bool "Technologic Systems TS-5500 platform support"
27857d029125SVivien Didelot	depends on MELAN
27867d029125SVivien Didelot	select CHECK_SIGNATURE
27877d029125SVivien Didelot	select NEW_LEDS
27887d029125SVivien Didelot	select LEDS_CLASS
27897d029125SVivien Didelot	---help---
27907d029125SVivien Didelot	  This option enables system support for the Technologic Systems TS-5500.
27917d029125SVivien Didelot
2792e279b6c1SSam Ravnborgendif # X86_32
2793e279b6c1SSam Ravnborg
279423ac4ae8SAndreas Herrmannconfig AMD_NB
2795e279b6c1SSam Ravnborg	def_bool y
27960e152cd7SBorislav Petkov	depends on CPU_SUP_AMD && PCI
2797e279b6c1SSam Ravnborg
2798e279b6c1SSam Ravnborgsource "drivers/pcmcia/Kconfig"
2799e279b6c1SSam Ravnborg
2800388b78adSAlexandre Bounineconfig RAPIDIO
2801fdf90abcSAlexandre Bounine	tristate "RapidIO support"
2802388b78adSAlexandre Bounine	depends on PCI
2803388b78adSAlexandre Bounine	default n
2804388b78adSAlexandre Bounine	help
2805fdf90abcSAlexandre Bounine	  If enabled this option will include drivers and the core
2806388b78adSAlexandre Bounine	  infrastructure code to support RapidIO interconnect devices.
2807388b78adSAlexandre Bounine
2808388b78adSAlexandre Bouninesource "drivers/rapidio/Kconfig"
2809388b78adSAlexandre Bounine
2810e3263ab3SDavid Herrmannconfig X86_SYSFB
2811e3263ab3SDavid Herrmann	bool "Mark VGA/VBE/EFI FB as generic system framebuffer"
2812e3263ab3SDavid Herrmann	help
2813e3263ab3SDavid Herrmann	  Firmwares often provide initial graphics framebuffers so the BIOS,
2814e3263ab3SDavid Herrmann	  bootloader or kernel can show basic video-output during boot for
2815e3263ab3SDavid Herrmann	  user-guidance and debugging. Historically, x86 used the VESA BIOS
2816e3263ab3SDavid Herrmann	  Extensions and EFI-framebuffers for this, which are mostly limited
2817e3263ab3SDavid Herrmann	  to x86.
2818e3263ab3SDavid Herrmann	  This option, if enabled, marks VGA/VBE/EFI framebuffers as generic
2819e3263ab3SDavid Herrmann	  framebuffers so the new generic system-framebuffer drivers can be
2820e3263ab3SDavid Herrmann	  used on x86. If the framebuffer is not compatible with the generic
2821e3263ab3SDavid Herrmann	  modes, it is adverticed as fallback platform framebuffer so legacy
2822e3263ab3SDavid Herrmann	  drivers like efifb, vesafb and uvesafb can pick it up.
2823e3263ab3SDavid Herrmann	  If this option is not selected, all system framebuffers are always
2824e3263ab3SDavid Herrmann	  marked as fallback platform framebuffers as usual.
2825e3263ab3SDavid Herrmann
2826e3263ab3SDavid Herrmann	  Note: Legacy fbdev drivers, including vesafb, efifb, uvesafb, will
2827e3263ab3SDavid Herrmann	  not be able to pick up generic system framebuffers if this option
2828e3263ab3SDavid Herrmann	  is selected. You are highly encouraged to enable simplefb as
2829e3263ab3SDavid Herrmann	  replacement if you select this option. simplefb can correctly deal
2830e3263ab3SDavid Herrmann	  with generic system framebuffers. But you should still keep vesafb
2831e3263ab3SDavid Herrmann	  and others enabled as fallback if a system framebuffer is
2832e3263ab3SDavid Herrmann	  incompatible with simplefb.
2833e3263ab3SDavid Herrmann
2834e3263ab3SDavid Herrmann	  If unsure, say Y.
2835e3263ab3SDavid Herrmann
2836e279b6c1SSam Ravnborgendmenu
2837e279b6c1SSam Ravnborg
2838e279b6c1SSam Ravnborg
2839e279b6c1SSam Ravnborgmenu "Executable file formats / Emulations"
2840e279b6c1SSam Ravnborg
2841e279b6c1SSam Ravnborgsource "fs/Kconfig.binfmt"
2842e279b6c1SSam Ravnborg
2843e279b6c1SSam Ravnborgconfig IA32_EMULATION
2844e279b6c1SSam Ravnborg	bool "IA32 Emulation"
2845e279b6c1SSam Ravnborg	depends on X86_64
284639f88911SIngo Molnar	select ARCH_WANT_OLD_COMPAT_IPC
2847d1603990SRandy Dunlap	select BINFMT_ELF
2848a97f52e6SRoland McGrath	select COMPAT_BINFMT_ELF
284939f88911SIngo Molnar	select COMPAT_OLD_SIGACTION
28508f9ca475SIngo Molnar	---help---
28515fd92e65SH. J. Lu	  Include code to run legacy 32-bit programs under a
28525fd92e65SH. J. Lu	  64-bit kernel. You should likely turn this on, unless you're
28535fd92e65SH. J. Lu	  100% sure that you don't have any 32-bit programs left.
2854e279b6c1SSam Ravnborg
2855e279b6c1SSam Ravnborgconfig IA32_AOUT
2856e279b6c1SSam Ravnborg	tristate "IA32 a.out support"
28576b213e1bSDavid Woodhouse	depends on IA32_EMULATION
28588f9ca475SIngo Molnar	---help---
2859e279b6c1SSam Ravnborg	  Support old a.out binaries in the 32bit emulation.
2860e279b6c1SSam Ravnborg
28610bf62763SH. Peter Anvinconfig X86_X32
28626ea30386SKees Cook	bool "x32 ABI for 64-bit mode"
28639b54050bSBrian Gerst	depends on X86_64
28645fd92e65SH. J. Lu	---help---
28655fd92e65SH. J. Lu	  Include code to run binaries for the x32 native 32-bit ABI
28665fd92e65SH. J. Lu	  for 64-bit processors.  An x32 process gets access to the
28675fd92e65SH. J. Lu	  full 64-bit register file and wide data path while leaving
28685fd92e65SH. J. Lu	  pointers at 32 bits for smaller memory footprint.
28695fd92e65SH. J. Lu
28705fd92e65SH. J. Lu	  You will need a recent binutils (2.22 or later) with
28715fd92e65SH. J. Lu	  elf32_x86_64 support enabled to compile a kernel with this
28725fd92e65SH. J. Lu	  option set.
28735fd92e65SH. J. Lu
2874953fee1dSIngo Molnarconfig COMPAT_32
2875953fee1dSIngo Molnar	def_bool y
2876953fee1dSIngo Molnar	depends on IA32_EMULATION || X86_32
2877953fee1dSIngo Molnar	select HAVE_UID16
2878953fee1dSIngo Molnar	select OLD_SIGSUSPEND3
2879953fee1dSIngo Molnar
2880e279b6c1SSam Ravnborgconfig COMPAT
28813c2362e6SHarvey Harrison	def_bool y
28820bf62763SH. Peter Anvin	depends on IA32_EMULATION || X86_X32
2883e279b6c1SSam Ravnborg
28843120e25eSJan Beulichif COMPAT
2885e279b6c1SSam Ravnborgconfig COMPAT_FOR_U64_ALIGNMENT
28863120e25eSJan Beulich	def_bool y
2887e279b6c1SSam Ravnborg
2888e279b6c1SSam Ravnborgconfig SYSVIPC_COMPAT
28893c2362e6SHarvey Harrison	def_bool y
28903120e25eSJan Beulich	depends on SYSVIPC
28913120e25eSJan Beulichendif
2892ee009e4aSDavid Howells
2893e279b6c1SSam Ravnborgendmenu
2894e279b6c1SSam Ravnborg
2895e279b6c1SSam Ravnborg
2896e5beae16SKeith Packardconfig HAVE_ATOMIC_IOMAP
2897e5beae16SKeith Packard	def_bool y
2898e5beae16SKeith Packard	depends on X86_32
2899e5beae16SKeith Packard
29004692d77fSAlessandro Rubiniconfig X86_DEV_DMA_OPS
29014692d77fSAlessandro Rubini	bool
290283125a3aSAlessandro Rubini	depends on X86_64 || STA2X11
29034692d77fSAlessandro Rubini
2904f7219a53SAlessandro Rubiniconfig X86_DMA_REMAP
2905f7219a53SAlessandro Rubini	bool
290683125a3aSAlessandro Rubini	depends on STA2X11
2907f7219a53SAlessandro Rubini
2908e585513bSKirill A. Shutemovconfig HAVE_GENERIC_GUP
2909e585513bSKirill A. Shutemov	def_bool y
2910e585513bSKirill A. Shutemov
2911e279b6c1SSam Ravnborgsource "net/Kconfig"
2912e279b6c1SSam Ravnborg
2913e279b6c1SSam Ravnborgsource "drivers/Kconfig"
2914e279b6c1SSam Ravnborg
2915e279b6c1SSam Ravnborgsource "drivers/firmware/Kconfig"
2916e279b6c1SSam Ravnborg
2917e279b6c1SSam Ravnborgsource "fs/Kconfig"
2918e279b6c1SSam Ravnborg
2919e279b6c1SSam Ravnborgsource "arch/x86/Kconfig.debug"
2920e279b6c1SSam Ravnborg
2921e279b6c1SSam Ravnborgsource "security/Kconfig"
2922e279b6c1SSam Ravnborg
2923e279b6c1SSam Ravnborgsource "crypto/Kconfig"
2924e279b6c1SSam Ravnborg
2925edf88417SAvi Kivitysource "arch/x86/kvm/Kconfig"
2926edf88417SAvi Kivity
2927e279b6c1SSam Ravnborgsource "lib/Kconfig"
2928