xref: /linux/arch/x86/Kconfig (revision 942fa985e9f161ac018ce2230d3e6f7668cca6ac)
1b2441318SGreg Kroah-Hartman# SPDX-License-Identifier: GPL-2.0
2daa93fabSSam Ravnborg# Select 32 or 64 bit
3daa93fabSSam Ravnborgconfig 64BIT
4104daea1SMasahiro Yamada	bool "64-bit kernel" if "$(ARCH)" = "x86"
5104daea1SMasahiro Yamada	default "$(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
31f616ab59SChristoph Hellwig	select NEED_DMA_MAP_STATE
3209230cbcSChristoph Hellwig	select SWIOTLB
33d94e0685SIngo Molnar	select X86_DEV_DMA_OPS
34f8781c4aSDominik Brodowski	select ARCH_HAS_SYSCALL_WRAPPER
351032c0baSSam Ravnborg
36d94e0685SIngo Molnar#
37d94e0685SIngo Molnar# Arch settings
38d94e0685SIngo Molnar#
39d94e0685SIngo Molnar# ( Note that options that are marked 'if X86_64' could in principle be
40d94e0685SIngo Molnar#   ported to 32-bit as well. )
41d94e0685SIngo Molnar#
428d5fffb9SSam Ravnborgconfig X86
433c2362e6SHarvey Harrison	def_bool y
44c763ea26SIngo Molnar	#
45c763ea26SIngo Molnar	# Note: keep this list sorted alphabetically
46c763ea26SIngo Molnar	#
476471b825SIngo Molnar	select ACPI_LEGACY_TABLES_LOOKUP	if ACPI
486e0a0ea1SGraeme Gregory	select ACPI_SYSTEM_POWER_STATES_SUPPORT	if ACPI
496471b825SIngo Molnar	select ANON_INODES
50*942fa985SYury Norov	select ARCH_32BIT_OFF_T			if X86_32
516471b825SIngo Molnar	select ARCH_CLOCKSOURCE_DATA
522a21ad57SThomas Gleixner	select ARCH_CLOCKSOURCE_INIT
536471b825SIngo Molnar	select ARCH_DISCARD_MEMBLOCK
5491dda51aSAleksey Makarov	select ARCH_HAS_ACPI_TABLE_UPGRADE	if ACPI
55fa5b6ec9SLaura Abbott	select ARCH_HAS_DEBUG_VIRTUAL
5621266be9SDan Williams	select ARCH_HAS_DEVMEM_IS_ALLOWED
576471b825SIngo Molnar	select ARCH_HAS_ELF_RANDOMIZE
5872d93104SLinus Torvalds	select ARCH_HAS_FAST_MULTIPLIER
59316d097cSDave Hansen	select ARCH_HAS_FILTER_PGPROT
606974f0c4SDaniel Micay	select ARCH_HAS_FORTIFY_SOURCE
61957e3facSRiku Voipio	select ARCH_HAS_GCOV_PROFILE_ALL
625c9a8750SDmitry Vyukov	select ARCH_HAS_KCOV			if X86_64
6310bcc80eSMathieu Desnoyers	select ARCH_HAS_MEMBARRIER_SYNC_CORE
64c763ea26SIngo Molnar	select ARCH_HAS_PMEM_API		if X86_64
653010a5eaSLaurent Dufour	select ARCH_HAS_PTE_SPECIAL
6639208aa7SKees Cook	select ARCH_HAS_REFCOUNT
670aed55afSDan Williams	select ARCH_HAS_UACCESS_FLUSHCACHE	if X86_64
68092b31aaSDan Williams	select ARCH_HAS_UACCESS_MCSAFE		if X86_64 && X86_MCE
69d2852a22SDaniel Borkmann	select ARCH_HAS_SET_MEMORY
70ad21fc4fSLaura Abbott	select ARCH_HAS_STRICT_KERNEL_RWX
71ad21fc4fSLaura Abbott	select ARCH_HAS_STRICT_MODULE_RWX
72ac1ab12aSMathieu Desnoyers	select ARCH_HAS_SYNC_CORE_BEFORE_USERMODE
73c6d30853SAndrey Ryabinin	select ARCH_HAS_UBSAN_SANITIZE_ALL
7465f7d049SOliver O'Halloran	select ARCH_HAS_ZONE_DEVICE		if X86_64
756471b825SIngo Molnar	select ARCH_HAVE_NMI_SAFE_CMPXCHG
766471b825SIngo Molnar	select ARCH_MIGHT_HAVE_ACPI_PDC		if ACPI
7777fbbc81SMark Salter	select ARCH_MIGHT_HAVE_PC_PARPORT
785e2c18c0SMark Salter	select ARCH_MIGHT_HAVE_PC_SERIO
792c870e61SArnd Bergmann	select ARCH_SUPPORTS_ACPI
806471b825SIngo Molnar	select ARCH_SUPPORTS_ATOMIC_RMW
816471b825SIngo Molnar	select ARCH_SUPPORTS_NUMA_BALANCING	if X86_64
826471b825SIngo Molnar	select ARCH_USE_BUILTIN_BSWAP
836471b825SIngo Molnar	select ARCH_USE_QUEUED_RWLOCKS
846471b825SIngo Molnar	select ARCH_USE_QUEUED_SPINLOCKS
85ce4a4e56SAndy Lutomirski	select ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH
86c763ea26SIngo Molnar	select ARCH_WANTS_DYNAMIC_TASK_STRUCT
8738d8b4e6SHuang Ying	select ARCH_WANTS_THP_SWAP		if X86_64
886471b825SIngo Molnar	select BUILDTIME_EXTABLE_SORT
896471b825SIngo Molnar	select CLKEVT_I8253
906471b825SIngo Molnar	select CLOCKSOURCE_VALIDATE_LAST_CYCLE
916471b825SIngo Molnar	select CLOCKSOURCE_WATCHDOG
926471b825SIngo Molnar	select DCACHE_WORD_ACCESS
9345471cd9SLinus Torvalds	select EDAC_ATOMIC_SCRUB
9445471cd9SLinus Torvalds	select EDAC_SUPPORT
956471b825SIngo Molnar	select GENERIC_CLOCKEVENTS
966471b825SIngo Molnar	select GENERIC_CLOCKEVENTS_BROADCAST	if X86_64 || (X86_32 && X86_LOCAL_APIC)
976471b825SIngo Molnar	select GENERIC_CLOCKEVENTS_MIN_ADJUST
986471b825SIngo Molnar	select GENERIC_CMOS_UPDATE
996471b825SIngo Molnar	select GENERIC_CPU_AUTOPROBE
10061dc0f55SThomas Gleixner	select GENERIC_CPU_VULNERABILITIES
1016471b825SIngo Molnar	select GENERIC_EARLY_IOREMAP
1026471b825SIngo Molnar	select GENERIC_FIND_FIRST_BIT
1036471b825SIngo Molnar	select GENERIC_IOMAP
104c7d6c9ddSThomas Gleixner	select GENERIC_IRQ_EFFECTIVE_AFF_MASK	if SMP
1050fa115daSThomas Gleixner	select GENERIC_IRQ_MATRIX_ALLOCATOR	if X86_LOCAL_APIC
106ad7a929fSThomas Gleixner	select GENERIC_IRQ_MIGRATION		if SMP
1076471b825SIngo Molnar	select GENERIC_IRQ_PROBE
108c201c917SThomas Gleixner	select GENERIC_IRQ_RESERVATION_MODE
1096471b825SIngo Molnar	select GENERIC_IRQ_SHOW
1106471b825SIngo Molnar	select GENERIC_PENDING_IRQ		if SMP
1116471b825SIngo Molnar	select GENERIC_SMP_IDLE_THREAD
1126471b825SIngo Molnar	select GENERIC_STRNCPY_FROM_USER
1136471b825SIngo Molnar	select GENERIC_STRNLEN_USER
1146471b825SIngo Molnar	select GENERIC_TIME_VSYSCALL
1157edaeb68SThomas Gleixner	select HARDLOCKUP_CHECK_TIMESTAMP	if X86_64
1166471b825SIngo Molnar	select HAVE_ACPI_APEI			if ACPI
1176471b825SIngo Molnar	select HAVE_ACPI_APEI_NMI		if ACPI
1186471b825SIngo Molnar	select HAVE_ALIGNED_STRUCT_PAGE		if SLUB
1196471b825SIngo Molnar	select HAVE_ARCH_AUDITSYSCALL
1206471b825SIngo Molnar	select HAVE_ARCH_HUGE_VMAP		if X86_64 || X86_PAE
1216471b825SIngo Molnar	select HAVE_ARCH_JUMP_LABEL
122b34006c4SArd Biesheuvel	select HAVE_ARCH_JUMP_LABEL_RELATIVE
123d17a1d97SAndrey Ryabinin	select HAVE_ARCH_KASAN			if X86_64
1246471b825SIngo Molnar	select HAVE_ARCH_KGDB
1259e08f57dSDaniel Cashman	select HAVE_ARCH_MMAP_RND_BITS		if MMU
1269e08f57dSDaniel Cashman	select HAVE_ARCH_MMAP_RND_COMPAT_BITS	if MMU && COMPAT
1271b028f78SDmitry Safonov	select HAVE_ARCH_COMPAT_MMAP_BASES	if MMU && COMPAT
128271ca788SArd Biesheuvel	select HAVE_ARCH_PREL32_RELOCATIONS
1296471b825SIngo Molnar	select HAVE_ARCH_SECCOMP_FILTER
130f7d83c1cSKees Cook	select HAVE_ARCH_THREAD_STRUCT_WHITELIST
131afaef01cSAlexander Popov	select HAVE_ARCH_STACKLEAK
1326471b825SIngo Molnar	select HAVE_ARCH_TRACEHOOK
1336471b825SIngo Molnar	select HAVE_ARCH_TRANSPARENT_HUGEPAGE
134a00cc7d9SMatthew Wilcox	select HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD if X86_64
135e37e43a4SAndy Lutomirski	select HAVE_ARCH_VMAP_STACK		if X86_64
136c763ea26SIngo Molnar	select HAVE_ARCH_WITHIN_STACK_FRAMES
1376471b825SIngo Molnar	select HAVE_CMPXCHG_DOUBLE
1386471b825SIngo Molnar	select HAVE_CMPXCHG_LOCAL
1396471b825SIngo Molnar	select HAVE_CONTEXT_TRACKING		if X86_64
140c1bd55f9SJosh Triplett	select HAVE_COPY_THREAD_TLS
1416471b825SIngo Molnar	select HAVE_C_RECORDMCOUNT
1426471b825SIngo Molnar	select HAVE_DEBUG_KMEMLEAK
1436471b825SIngo Molnar	select HAVE_DEBUG_STACKOVERFLOW
1449c5a3621SAkinobu Mita	select HAVE_DMA_CONTIGUOUS
145677aa9f7SSteven Rostedt	select HAVE_DYNAMIC_FTRACE
14606aeaaeaSMasami Hiramatsu	select HAVE_DYNAMIC_FTRACE_WITH_REGS
14703f5781bSWang YanQing	select HAVE_EBPF_JIT
14858340a07SJohannes Berg	select HAVE_EFFICIENT_UNALIGNED_ACCESS
1496630a8e5SChristoph Hellwig	select HAVE_EISA
1505f56a5dfSJiri Slaby	select HAVE_EXIT_THREAD
151644e0e8dSSteven Rostedt (VMware)	select HAVE_FENTRY			if X86_64 || DYNAMIC_FTRACE
1526471b825SIngo Molnar	select HAVE_FTRACE_MCOUNT_RECORD
1536471b825SIngo Molnar	select HAVE_FUNCTION_GRAPH_TRACER
1546471b825SIngo Molnar	select HAVE_FUNCTION_TRACER
1556b90bd4bSEmese Revfy	select HAVE_GCC_PLUGINS
1560067f129SK.Prasad	select HAVE_HW_BREAKPOINT
1576471b825SIngo Molnar	select HAVE_IDE
1586471b825SIngo Molnar	select HAVE_IOREMAP_PROT
1596471b825SIngo Molnar	select HAVE_IRQ_EXIT_ON_IRQ_STACK	if X86_64
1606471b825SIngo Molnar	select HAVE_IRQ_TIME_ACCOUNTING
1616471b825SIngo Molnar	select HAVE_KERNEL_BZIP2
1626471b825SIngo Molnar	select HAVE_KERNEL_GZIP
1636471b825SIngo Molnar	select HAVE_KERNEL_LZ4
1646471b825SIngo Molnar	select HAVE_KERNEL_LZMA
1656471b825SIngo Molnar	select HAVE_KERNEL_LZO
1666471b825SIngo Molnar	select HAVE_KERNEL_XZ
1676471b825SIngo Molnar	select HAVE_KPROBES
1686471b825SIngo Molnar	select HAVE_KPROBES_ON_FTRACE
169540adea3SMasami Hiramatsu	select HAVE_FUNCTION_ERROR_INJECTION
1706471b825SIngo Molnar	select HAVE_KRETPROBES
1716471b825SIngo Molnar	select HAVE_KVM
1726471b825SIngo Molnar	select HAVE_LIVEPATCH			if X86_64
1736471b825SIngo Molnar	select HAVE_MEMBLOCK_NODE_MAP
1740102752eSFrederic Weisbecker	select HAVE_MIXED_BREAKPOINTS_REGS
175ee9f8fceSJosh Poimboeuf	select HAVE_MOD_ARCH_SPECIFIC
1769f132f7eSJoel Fernandes (Google)	select HAVE_MOVE_PMD
17742a0bb3fSPetr Mladek	select HAVE_NMI
1786471b825SIngo Molnar	select HAVE_OPROFILE
1796471b825SIngo Molnar	select HAVE_OPTPROBES
1806471b825SIngo Molnar	select HAVE_PCSPKR_PLATFORM
1816471b825SIngo Molnar	select HAVE_PERF_EVENTS
182c01d4323SFrederic Weisbecker	select HAVE_PERF_EVENTS_NMI
18392e5aae4SNicholas Piggin	select HAVE_HARDLOCKUP_DETECTOR_PERF	if PERF_EVENTS && HAVE_PERF_EVENTS_NMI
184eb01d42aSChristoph Hellwig	select HAVE_PCI
185c5e63197SJiri Olsa	select HAVE_PERF_REGS
186c5ebcedbSJiri Olsa	select HAVE_PERF_USER_STACK_DUMP
18748a8b97cSPeter Zijlstra	select HAVE_RCU_TABLE_FREE		if PARAVIRT
188d86564a2SPeter Zijlstra	select HAVE_RCU_TABLE_INVALIDATE	if HAVE_RCU_TABLE_FREE
1896471b825SIngo Molnar	select HAVE_REGS_AND_STACK_ACCESS_API
1906415b38bSJiri Slaby	select HAVE_RELIABLE_STACKTRACE		if X86_64 && (UNWINDER_FRAME_POINTER || UNWINDER_ORC) && STACK_VALIDATION
1913c88ee19SMasami Hiramatsu	select HAVE_FUNCTION_ARG_ACCESS_API
192d148eac0SMasahiro Yamada	select HAVE_STACKPROTECTOR		if CC_HAS_SANE_STACKPROTECTOR
193c763ea26SIngo Molnar	select HAVE_STACK_VALIDATION		if X86_64
194d6761b8fSMathieu Desnoyers	select HAVE_RSEQ
1956471b825SIngo Molnar	select HAVE_SYSCALL_TRACEPOINTS
1966471b825SIngo Molnar	select HAVE_UNSTABLE_SCHED_CLOCK
1977c68af6eSAvi Kivity	select HAVE_USER_RETURN_NOTIFIER
19805736e4aSThomas Gleixner	select HOTPLUG_SMT			if SMP
199c0185808SThomas Gleixner	select IRQ_FORCED_THREADING
20086596f0aSChristoph Hellwig	select NEED_SG_DMA_LENGTH
2012eac9c2dSChristoph Hellwig	select PCI_DOMAINS			if PCI
202df65c1bcSThomas Gleixner	select PCI_LOCKLESS_CONFIG
2036471b825SIngo Molnar	select PERF_EVENTS
2043195ef59SPrarit Bhargava	select RTC_LIB
205d6faca40SArnd Bergmann	select RTC_MC146818_LIB
2066471b825SIngo Molnar	select SPARSE_IRQ
20783fe27eaSPranith Kumar	select SRCU
2086471b825SIngo Molnar	select SYSCTL_EXCEPTION_TRACE
20915f4eae7SAndy Lutomirski	select THREAD_INFO_IN_TASK
2106471b825SIngo Molnar	select USER_STACKTRACE_SUPPORT
2116471b825SIngo Molnar	select VIRT_TO_BUS
2126471b825SIngo Molnar	select X86_FEATURE_NAMES		if PROC_FS
2137d8330a5SBalbir Singh
214ba7e4d13SIngo Molnarconfig INSTRUCTION_DECODER
2153120e25eSJan Beulich	def_bool y
2163120e25eSJan Beulich	depends on KPROBES || PERF_EVENTS || UPROBES
217ba7e4d13SIngo Molnar
21851b26adaSLinus Torvaldsconfig OUTPUT_FORMAT
21951b26adaSLinus Torvalds	string
22051b26adaSLinus Torvalds	default "elf32-i386" if X86_32
22151b26adaSLinus Torvalds	default "elf64-x86-64" if X86_64
22251b26adaSLinus Torvalds
22373531905SSam Ravnborgconfig ARCH_DEFCONFIG
224b9b39bfbSSam Ravnborg	string
22573531905SSam Ravnborg	default "arch/x86/configs/i386_defconfig" if X86_32
22673531905SSam Ravnborg	default "arch/x86/configs/x86_64_defconfig" if X86_64
227b9b39bfbSSam Ravnborg
2288d5fffb9SSam Ravnborgconfig LOCKDEP_SUPPORT
2293c2362e6SHarvey Harrison	def_bool y
2308d5fffb9SSam Ravnborg
2318d5fffb9SSam Ravnborgconfig STACKTRACE_SUPPORT
2323c2362e6SHarvey Harrison	def_bool y
2338d5fffb9SSam Ravnborg
2348d5fffb9SSam Ravnborgconfig MMU
2353c2362e6SHarvey Harrison	def_bool y
2368d5fffb9SSam Ravnborg
2379e08f57dSDaniel Cashmanconfig ARCH_MMAP_RND_BITS_MIN
2389e08f57dSDaniel Cashman	default 28 if 64BIT
2399e08f57dSDaniel Cashman	default 8
2409e08f57dSDaniel Cashman
2419e08f57dSDaniel Cashmanconfig ARCH_MMAP_RND_BITS_MAX
2429e08f57dSDaniel Cashman	default 32 if 64BIT
2439e08f57dSDaniel Cashman	default 16
2449e08f57dSDaniel Cashman
2459e08f57dSDaniel Cashmanconfig ARCH_MMAP_RND_COMPAT_BITS_MIN
2469e08f57dSDaniel Cashman	default 8
2479e08f57dSDaniel Cashman
2489e08f57dSDaniel Cashmanconfig ARCH_MMAP_RND_COMPAT_BITS_MAX
2499e08f57dSDaniel Cashman	default 16
2509e08f57dSDaniel Cashman
2518d5fffb9SSam Ravnborgconfig SBUS
2528d5fffb9SSam Ravnborg	bool
2538d5fffb9SSam Ravnborg
2548d5fffb9SSam Ravnborgconfig GENERIC_ISA_DMA
2553120e25eSJan Beulich	def_bool y
2563120e25eSJan Beulich	depends on ISA_DMA_API
2578d5fffb9SSam Ravnborg
2588d5fffb9SSam Ravnborgconfig GENERIC_BUG
2593c2362e6SHarvey Harrison	def_bool y
2608d5fffb9SSam Ravnborg	depends on BUG
261b93a531eSJan Beulich	select GENERIC_BUG_RELATIVE_POINTERS if X86_64
262b93a531eSJan Beulich
263b93a531eSJan Beulichconfig GENERIC_BUG_RELATIVE_POINTERS
264b93a531eSJan Beulich	bool
2658d5fffb9SSam Ravnborg
2668d5fffb9SSam Ravnborgconfig GENERIC_HWEIGHT
2673c2362e6SHarvey Harrison	def_bool y
2688d5fffb9SSam Ravnborg
2698d5fffb9SSam Ravnborgconfig ARCH_MAY_HAVE_PC_FDC
2703120e25eSJan Beulich	def_bool y
2713120e25eSJan Beulich	depends on ISA_DMA_API
2728d5fffb9SSam Ravnborg
2731032c0baSSam Ravnborgconfig RWSEM_XCHGADD_ALGORITHM
2743120e25eSJan Beulich	def_bool y
2751032c0baSSam Ravnborg
2761032c0baSSam Ravnborgconfig GENERIC_CALIBRATE_DELAY
2771032c0baSSam Ravnborg	def_bool y
2781032c0baSSam Ravnborg
2799a0b8415Svenkatesh.pallipadi@intel.comconfig ARCH_HAS_CPU_RELAX
2809a0b8415Svenkatesh.pallipadi@intel.com	def_bool y
2818d5fffb9SSam Ravnborg
2821b27d05bSPekka Enbergconfig ARCH_HAS_CACHE_LINE_SIZE
2831b27d05bSPekka Enberg	def_bool y
2841b27d05bSPekka Enberg
285316d097cSDave Hansenconfig ARCH_HAS_FILTER_PGPROT
286316d097cSDave Hansen	def_bool y
287316d097cSDave Hansen
288dd5af90aSMike Travisconfig HAVE_SETUP_PER_CPU_AREA
28989c9c4c5SBrian Gerst	def_bool y
290b32ef636Stravis@sgi.com
29108fc4580STejun Heoconfig NEED_PER_CPU_EMBED_FIRST_CHUNK
29208fc4580STejun Heo	def_bool y
29308fc4580STejun Heo
29408fc4580STejun Heoconfig NEED_PER_CPU_PAGE_FIRST_CHUNK
29511124411STejun Heo	def_bool y
29611124411STejun Heo
297801e4062SJohannes Bergconfig ARCH_HIBERNATION_POSSIBLE
298801e4062SJohannes Berg	def_bool y
299801e4062SJohannes Berg
300f4cb5700SJohannes Bergconfig ARCH_SUSPEND_POSSIBLE
301f4cb5700SJohannes Berg	def_bool y
302f4cb5700SJohannes Berg
303cfe28c5dSSteve Capperconfig ARCH_WANT_HUGE_PMD_SHARE
304cfe28c5dSSteve Capper	def_bool y
305cfe28c5dSSteve Capper
30653313b2cSSteve Capperconfig ARCH_WANT_GENERAL_HUGETLB
30753313b2cSSteve Capper	def_bool y
30853313b2cSSteve Capper
3098d5fffb9SSam Ravnborgconfig ZONE_DMA32
310e0fd24a3SJan Beulich	def_bool y if X86_64
3118d5fffb9SSam Ravnborg
3128d5fffb9SSam Ravnborgconfig AUDIT_ARCH
313e0fd24a3SJan Beulich	def_bool y if X86_64
3148d5fffb9SSam Ravnborg
315765c68bdSIngo Molnarconfig ARCH_SUPPORTS_OPTIMIZED_INLINING
316765c68bdSIngo Molnar	def_bool y
317765c68bdSIngo Molnar
3186a11f75bSAkinobu Mitaconfig ARCH_SUPPORTS_DEBUG_PAGEALLOC
3196a11f75bSAkinobu Mita	def_bool y
3206a11f75bSAkinobu Mita
321d6f2d75aSAndrey Ryabininconfig KASAN_SHADOW_OFFSET
322d6f2d75aSAndrey Ryabinin	hex
323d6f2d75aSAndrey Ryabinin	depends on KASAN
324d6f2d75aSAndrey Ryabinin	default 0xdffffc0000000000
325d6f2d75aSAndrey Ryabinin
32669575d38SShane Wangconfig HAVE_INTEL_TXT
32769575d38SShane Wang	def_bool y
3286ea30386SKees Cook	depends on INTEL_IOMMU && ACPI
32969575d38SShane Wang
3306b0c3d44SSam Ravnborgconfig X86_32_SMP
3316b0c3d44SSam Ravnborg	def_bool y
3326b0c3d44SSam Ravnborg	depends on X86_32 && SMP
3336b0c3d44SSam Ravnborg
3346b0c3d44SSam Ravnborgconfig X86_64_SMP
3356b0c3d44SSam Ravnborg	def_bool y
3366b0c3d44SSam Ravnborg	depends on X86_64 && SMP
3376b0c3d44SSam Ravnborg
338ccbeed3aSTejun Heoconfig X86_32_LAZY_GS
339ccbeed3aSTejun Heo	def_bool y
3408458f8c2SMasahiro Yamada	depends on X86_32 && !STACKPROTECTOR
341ccbeed3aSTejun Heo
3422b144498SSrikar Dronamrajuconfig ARCH_SUPPORTS_UPROBES
3432b144498SSrikar Dronamraju	def_bool y
3442b144498SSrikar Dronamraju
345d20642f0SRob Herringconfig FIX_EARLYCON_MEM
346d20642f0SRob Herring	def_bool y
347d20642f0SRob Herring
34894d49eb3SKirill A. Shutemovconfig DYNAMIC_PHYSICAL_MASK
34994d49eb3SKirill A. Shutemov	bool
35094d49eb3SKirill A. Shutemov
35198233368SKirill A. Shutemovconfig PGTABLE_LEVELS
35298233368SKirill A. Shutemov	int
35377ef56e4SKirill A. Shutemov	default 5 if X86_5LEVEL
35498233368SKirill A. Shutemov	default 4 if X86_64
35598233368SKirill A. Shutemov	default 3 if X86_PAE
35698233368SKirill A. Shutemov	default 2
35798233368SKirill A. Shutemov
3582a61f474SMasahiro Yamadaconfig CC_HAS_SANE_STACKPROTECTOR
3592a61f474SMasahiro Yamada	bool
3602a61f474SMasahiro Yamada	default $(success,$(srctree)/scripts/gcc-x86_64-has-stack-protector.sh $(CC)) if 64BIT
3612a61f474SMasahiro Yamada	default $(success,$(srctree)/scripts/gcc-x86_32-has-stack-protector.sh $(CC))
3622a61f474SMasahiro Yamada	help
3632a61f474SMasahiro Yamada	   We have to make sure stack protector is unconditionally disabled if
3642a61f474SMasahiro Yamada	   the compiler produces broken code.
3652a61f474SMasahiro Yamada
366506f1d07SSam Ravnborgmenu "Processor type and features"
367506f1d07SSam Ravnborg
3685ee71535SRandy Dunlapconfig ZONE_DMA
3695ee71535SRandy Dunlap	bool "DMA memory allocation support" if EXPERT
3705ee71535SRandy Dunlap	default y
3715ee71535SRandy Dunlap	help
3725ee71535SRandy Dunlap	  DMA memory allocation support allows devices with less than 32-bit
3735ee71535SRandy Dunlap	  addressing to allocate within the first 16MB of address space.
3745ee71535SRandy Dunlap	  Disable if no such devices will be used.
3755ee71535SRandy Dunlap
3765ee71535SRandy Dunlap	  If unsure, say Y.
3775ee71535SRandy Dunlap
378506f1d07SSam Ravnborgconfig SMP
379506f1d07SSam Ravnborg	bool "Symmetric multi-processing support"
380506f1d07SSam Ravnborg	---help---
381506f1d07SSam Ravnborg	  This enables support for systems with more than one CPU. If you have
3824a474157SRobert Graffham	  a system with only one CPU, say N. If you have a system with more
3834a474157SRobert Graffham	  than one CPU, say Y.
384506f1d07SSam Ravnborg
3854a474157SRobert Graffham	  If you say N here, the kernel will run on uni- and multiprocessor
386506f1d07SSam Ravnborg	  machines, but will use only one CPU of a multiprocessor machine. If
387506f1d07SSam Ravnborg	  you say Y here, the kernel will run on many, but not all,
3884a474157SRobert Graffham	  uniprocessor machines. On a uniprocessor machine, the kernel
389506f1d07SSam Ravnborg	  will run faster if you say N here.
390506f1d07SSam Ravnborg
391506f1d07SSam Ravnborg	  Note that if you say Y here and choose architecture "586" or
392506f1d07SSam Ravnborg	  "Pentium" under "Processor family", the kernel will not work on 486
393506f1d07SSam Ravnborg	  architectures. Similarly, multiprocessor kernels for the "PPro"
394506f1d07SSam Ravnborg	  architecture may not work on all Pentium based boards.
395506f1d07SSam Ravnborg
396506f1d07SSam Ravnborg	  People using multiprocessor machines who say Y here should also say
397506f1d07SSam Ravnborg	  Y to "Enhanced Real Time Clock Support", below. The "Advanced Power
398506f1d07SSam Ravnborg	  Management" code will be disabled if you say Y here.
399506f1d07SSam Ravnborg
400395cf969SPaul Bolle	  See also <file:Documentation/x86/i386/IO-APIC.txt>,
401c9525a3fSBenjamin Peterson	  <file:Documentation/lockup-watchdogs.txt> and the SMP-HOWTO available at
402506f1d07SSam Ravnborg	  <http://www.tldp.org/docs.html#howto>.
403506f1d07SSam Ravnborg
404506f1d07SSam Ravnborg	  If you don't know what to do here, say N.
405506f1d07SSam Ravnborg
4069def39beSJosh Triplettconfig X86_FEATURE_NAMES
4079def39beSJosh Triplett	bool "Processor feature human-readable names" if EMBEDDED
4089def39beSJosh Triplett	default y
4099def39beSJosh Triplett	---help---
4109def39beSJosh Triplett	  This option compiles in a table of x86 feature bits and corresponding
4119def39beSJosh Triplett	  names.  This is required to support /proc/cpuinfo and a few kernel
4129def39beSJosh Triplett	  messages.  You can disable this to save space, at the expense of
4139def39beSJosh Triplett	  making those few kernel messages show numeric feature bits instead.
4149def39beSJosh Triplett
4159def39beSJosh Triplett	  If in doubt, say Y.
4169def39beSJosh Triplett
41706cd9a7dSYinghai Luconfig X86_X2APIC
41806cd9a7dSYinghai Lu	bool "Support x2apic"
41919e3d60dSJan Kiszka	depends on X86_LOCAL_APIC && X86_64 && (IRQ_REMAP || HYPERVISOR_GUEST)
42006cd9a7dSYinghai Lu	---help---
42106cd9a7dSYinghai Lu	  This enables x2apic support on CPUs that have this feature.
42206cd9a7dSYinghai Lu
42306cd9a7dSYinghai Lu	  This allows 32-bit apic IDs (so it can support very large systems),
42406cd9a7dSYinghai Lu	  and accesses the local apic via MSRs not via mmio.
42506cd9a7dSYinghai Lu
42606cd9a7dSYinghai Lu	  If you don't know what to do here, say N.
42706cd9a7dSYinghai Lu
4286695c85bSYinghai Luconfig X86_MPPARSE
4296e87f9b7SBin Gao	bool "Enable MPS table" if ACPI || SFI
4307a527688SJan Beulich	default y
4315ab74722SIngo Molnar	depends on X86_LOCAL_APIC
4328f9ca475SIngo Molnar	---help---
4336695c85bSYinghai Lu	  For old smp systems that do not have proper acpi support. Newer systems
4346695c85bSYinghai Lu	  (esp with 64bit cpus) with acpi support, MADT and DSDT will override it
4356695c85bSYinghai Lu
436ddd70cf9SJun Nakajimaconfig GOLDFISH
437ddd70cf9SJun Nakajima       def_bool y
438ddd70cf9SJun Nakajima       depends on X86_GOLDFISH
439ddd70cf9SJun Nakajima
44076b04384SDavid Woodhouseconfig RETPOLINE
44176b04384SDavid Woodhouse	bool "Avoid speculative indirect branches in kernel"
44276b04384SDavid Woodhouse	default y
443d5028ba8SPeter Zijlstra	select STACK_VALIDATION if HAVE_STACK_VALIDATION
44476b04384SDavid Woodhouse	help
44576b04384SDavid Woodhouse	  Compile kernel with the retpoline compiler options to guard against
44676b04384SDavid Woodhouse	  kernel-to-user data leaks by avoiding speculative indirect
44776b04384SDavid Woodhouse	  branches. Requires a compiler with -mindirect-branch=thunk-extern
44876b04384SDavid Woodhouse	  support for full protection. The kernel may run slower.
44976b04384SDavid Woodhouse
45090802938SBorislav Petkovconfig X86_RESCTRL
4516fe07ce3SBabu Moger	bool "Resource Control support"
4526fe07ce3SBabu Moger	depends on X86 && (CPU_SUP_INTEL || CPU_SUP_AMD)
45359fe5a77SThomas Gleixner	select KERNFS
45478e99b4aSFenghua Yu	help
4556fe07ce3SBabu Moger	  Enable Resource Control support.
4566fe07ce3SBabu Moger
4576fe07ce3SBabu Moger	  Provide support for the allocation and monitoring of system resources
4586fe07ce3SBabu Moger	  usage by the CPU.
4596fe07ce3SBabu Moger
4606fe07ce3SBabu Moger	  Intel calls this Intel Resource Director Technology
4616fe07ce3SBabu Moger	  (Intel(R) RDT). More information about RDT can be found in the
4626fe07ce3SBabu Moger	  Intel x86 Architecture Software Developer Manual.
4636fe07ce3SBabu Moger
4646fe07ce3SBabu Moger	  AMD calls this AMD Platform Quality of Service (AMD QoS).
4656fe07ce3SBabu Moger	  More information about AMD QoS can be found in the AMD64 Technology
4666fe07ce3SBabu Moger	  Platform Quality of Service Extensions manual.
46778e99b4aSFenghua Yu
46878e99b4aSFenghua Yu	  Say N if unsure.
46978e99b4aSFenghua Yu
4708425091fSRavikiran G Thirumalaiif X86_32
471a0d0bb4dSRandy Dunlapconfig X86_BIGSMP
472a0d0bb4dSRandy Dunlap	bool "Support for big SMP systems with more than 8 CPUs"
473a0d0bb4dSRandy Dunlap	depends on SMP
474a0d0bb4dSRandy Dunlap	---help---
475a0d0bb4dSRandy Dunlap	  This option is needed for the systems that have more than 8 CPUs
476a0d0bb4dSRandy Dunlap
477c5c606d9SRavikiran G Thirumalaiconfig X86_EXTENDED_PLATFORM
478c5c606d9SRavikiran G Thirumalai	bool "Support for extended (non-PC) x86 platforms"
479c5c606d9SRavikiran G Thirumalai	default y
4808f9ca475SIngo Molnar	---help---
48106ac8346SIngo Molnar	  If you disable this option then the kernel will only support
48206ac8346SIngo Molnar	  standard PC platforms. (which covers the vast majority of
48306ac8346SIngo Molnar	  systems out there.)
48406ac8346SIngo Molnar
4858425091fSRavikiran G Thirumalai	  If you enable this option then you'll be able to select support
4868425091fSRavikiran G Thirumalai	  for the following (non-PC) 32 bit x86 platforms:
487cb7b8023SBen Hutchings		Goldfish (Android emulator)
4888425091fSRavikiran G Thirumalai		AMD Elan
4898425091fSRavikiran G Thirumalai		RDC R-321x SoC
4908425091fSRavikiran G Thirumalai		SGI 320/540 (Visual Workstation)
49183125a3aSAlessandro Rubini		STA2X11-based (e.g. Northville)
4923f4110a4SThomas Gleixner		Moorestown MID devices
49306ac8346SIngo Molnar
49406ac8346SIngo Molnar	  If you have one of these systems, or if you want to build a
49506ac8346SIngo Molnar	  generic distribution kernel, say Y here - otherwise say N.
4968425091fSRavikiran G Thirumalaiendif
49706ac8346SIngo Molnar
4988425091fSRavikiran G Thirumalaiif X86_64
4998425091fSRavikiran G Thirumalaiconfig X86_EXTENDED_PLATFORM
5008425091fSRavikiran G Thirumalai	bool "Support for extended (non-PC) x86 platforms"
5018425091fSRavikiran G Thirumalai	default y
5028425091fSRavikiran G Thirumalai	---help---
5038425091fSRavikiran G Thirumalai	  If you disable this option then the kernel will only support
5048425091fSRavikiran G Thirumalai	  standard PC platforms. (which covers the vast majority of
5058425091fSRavikiran G Thirumalai	  systems out there.)
5068425091fSRavikiran G Thirumalai
5078425091fSRavikiran G Thirumalai	  If you enable this option then you'll be able to select support
5088425091fSRavikiran G Thirumalai	  for the following (non-PC) 64 bit x86 platforms:
50944b111b5SSteffen Persvold		Numascale NumaChip
5108425091fSRavikiran G Thirumalai		ScaleMP vSMP
5118425091fSRavikiran G Thirumalai		SGI Ultraviolet
5128425091fSRavikiran G Thirumalai
5138425091fSRavikiran G Thirumalai	  If you have one of these systems, or if you want to build a
5148425091fSRavikiran G Thirumalai	  generic distribution kernel, say Y here - otherwise say N.
5158425091fSRavikiran G Thirumalaiendif
516c5c606d9SRavikiran G Thirumalai# This is an alphabetically sorted list of 64 bit extended platforms
517c5c606d9SRavikiran G Thirumalai# Please maintain the alphabetic order if and when there are additions
51844b111b5SSteffen Persvoldconfig X86_NUMACHIP
51944b111b5SSteffen Persvold	bool "Numascale NumaChip"
52044b111b5SSteffen Persvold	depends on X86_64
52144b111b5SSteffen Persvold	depends on X86_EXTENDED_PLATFORM
52244b111b5SSteffen Persvold	depends on NUMA
52344b111b5SSteffen Persvold	depends on SMP
52444b111b5SSteffen Persvold	depends on X86_X2APIC
525f9726bfdSDaniel J Blueman	depends on PCI_MMCONFIG
52644b111b5SSteffen Persvold	---help---
52744b111b5SSteffen Persvold	  Adds support for Numascale NumaChip large-SMP systems. Needed to
52844b111b5SSteffen Persvold	  enable more than ~168 cores.
52944b111b5SSteffen Persvold	  If you don't have one of these, you should say N here.
53003b48632SNick Piggin
5316a48565eSIngo Molnarconfig X86_VSMP
532c5c606d9SRavikiran G Thirumalai	bool "ScaleMP vSMP"
5336276a074SBorislav Petkov	select HYPERVISOR_GUEST
5346a48565eSIngo Molnar	select PARAVIRT
5356a48565eSIngo Molnar	depends on X86_64 && PCI
536c5c606d9SRavikiran G Thirumalai	depends on X86_EXTENDED_PLATFORM
537ead91d4bSShai Fultheim	depends on SMP
5388f9ca475SIngo Molnar	---help---
5396a48565eSIngo Molnar	  Support for ScaleMP vSMP systems.  Say 'Y' here if this kernel is
5406a48565eSIngo Molnar	  supposed to run on these EM64T-based machines.  Only choose this option
5416a48565eSIngo Molnar	  if you have one of these machines.
5426a48565eSIngo Molnar
543c5c606d9SRavikiran G Thirumalaiconfig X86_UV
544c5c606d9SRavikiran G Thirumalai	bool "SGI Ultraviolet"
545c5c606d9SRavikiran G Thirumalai	depends on X86_64
546c5c606d9SRavikiran G Thirumalai	depends on X86_EXTENDED_PLATFORM
54754c28d29SJack Steiner	depends on NUMA
5481ecb4ae5SAndrew Morton	depends on EFI
5499d6c26e7SSuresh Siddha	depends on X86_X2APIC
5501222e564SIngo Molnar	depends on PCI
551c5c606d9SRavikiran G Thirumalai	---help---
552c5c606d9SRavikiran G Thirumalai	  This option is needed in order to support SGI Ultraviolet systems.
553c5c606d9SRavikiran G Thirumalai	  If you don't have one of these, you should say N here.
554c5c606d9SRavikiran G Thirumalai
555c5c606d9SRavikiran G Thirumalai# Following is an alphabetically sorted list of 32 bit extended platforms
556c5c606d9SRavikiran G Thirumalai# Please maintain the alphabetic order if and when there are additions
557506f1d07SSam Ravnborg
558ddd70cf9SJun Nakajimaconfig X86_GOLDFISH
559ddd70cf9SJun Nakajima       bool "Goldfish (Virtual Platform)"
560cb7b8023SBen Hutchings       depends on X86_EXTENDED_PLATFORM
561ddd70cf9SJun Nakajima       ---help---
562ddd70cf9SJun Nakajima	 Enable support for the Goldfish virtual platform used primarily
563ddd70cf9SJun Nakajima	 for Android development. Unless you are building for the Android
564ddd70cf9SJun Nakajima	 Goldfish emulator say N here.
565ddd70cf9SJun Nakajima
566c751e17bSThomas Gleixnerconfig X86_INTEL_CE
567c751e17bSThomas Gleixner	bool "CE4100 TV platform"
568c751e17bSThomas Gleixner	depends on PCI
569c751e17bSThomas Gleixner	depends on PCI_GODIRECT
5706084a6e2SJiang Liu	depends on X86_IO_APIC
571c751e17bSThomas Gleixner	depends on X86_32
572c751e17bSThomas Gleixner	depends on X86_EXTENDED_PLATFORM
57337bc9f50SDirk Brandewie	select X86_REBOOTFIXUPS
574da6b737bSSebastian Andrzej Siewior	select OF
575da6b737bSSebastian Andrzej Siewior	select OF_EARLY_FLATTREE
576c751e17bSThomas Gleixner	---help---
577c751e17bSThomas Gleixner	  Select for the Intel CE media processor (CE4100) SOC.
578c751e17bSThomas Gleixner	  This option compiles in support for the CE4100 SOC for settop
579c751e17bSThomas Gleixner	  boxes and media devices.
580c751e17bSThomas Gleixner
5814cb9b00fSDavid Cohenconfig X86_INTEL_MID
58243605ef1SAlan Cox	bool "Intel MID platform support"
58343605ef1SAlan Cox	depends on X86_EXTENDED_PLATFORM
584edc6bc78SDavid Cohen	depends on X86_PLATFORM_DEVICES
5851ea7c673SAlan Cox	depends on PCI
5863fda5bb4SAndy Shevchenko	depends on X86_64 || (PCI_GOANY && X86_32)
5871ea7c673SAlan Cox	depends on X86_IO_APIC
5887c9c3a1eSAlan Cox	select SFI
5894cb9b00fSDavid Cohen	select I2C
5907c9c3a1eSAlan Cox	select DW_APB_TIMER
5911ea7c673SAlan Cox	select APB_TIMER
5921ea7c673SAlan Cox	select INTEL_SCU_IPC
59315a713dfSMika Westerberg	select MFD_INTEL_MSIC
5941ea7c673SAlan Cox	---help---
5954cb9b00fSDavid Cohen	  Select to build a kernel capable of supporting Intel MID (Mobile
5964cb9b00fSDavid Cohen	  Internet Device) platform systems which do not have the PCI legacy
5974cb9b00fSDavid Cohen	  interfaces. If you are building for a PC class system say N here.
5981ea7c673SAlan Cox
5994cb9b00fSDavid Cohen	  Intel MID platforms are based on an Intel processor and chipset which
6004cb9b00fSDavid Cohen	  consume less power than most of the x86 derivatives.
60143605ef1SAlan Cox
6028bbc2a13SBryan O'Donoghueconfig X86_INTEL_QUARK
6038bbc2a13SBryan O'Donoghue	bool "Intel Quark platform support"
6048bbc2a13SBryan O'Donoghue	depends on X86_32
6058bbc2a13SBryan O'Donoghue	depends on X86_EXTENDED_PLATFORM
6068bbc2a13SBryan O'Donoghue	depends on X86_PLATFORM_DEVICES
6078bbc2a13SBryan O'Donoghue	depends on X86_TSC
6088bbc2a13SBryan O'Donoghue	depends on PCI
6098bbc2a13SBryan O'Donoghue	depends on PCI_GOANY
6108bbc2a13SBryan O'Donoghue	depends on X86_IO_APIC
6118bbc2a13SBryan O'Donoghue	select IOSF_MBI
6128bbc2a13SBryan O'Donoghue	select INTEL_IMR
6139ab6eb51SAndy Shevchenko	select COMMON_CLK
6148bbc2a13SBryan O'Donoghue	---help---
6158bbc2a13SBryan O'Donoghue	  Select to include support for Quark X1000 SoC.
6168bbc2a13SBryan O'Donoghue	  Say Y here if you have a Quark based system such as the Arduino
6178bbc2a13SBryan O'Donoghue	  compatible Intel Galileo.
6188bbc2a13SBryan O'Donoghue
6193d48aab1SMika Westerbergconfig X86_INTEL_LPSS
6203d48aab1SMika Westerberg	bool "Intel Low Power Subsystem Support"
621eebb3e8dSAndy Shevchenko	depends on X86 && ACPI
6223d48aab1SMika Westerberg	select COMMON_CLK
6230f531431SMathias Nyman	select PINCTRL
624eebb3e8dSAndy Shevchenko	select IOSF_MBI
6253d48aab1SMika Westerberg	---help---
6263d48aab1SMika Westerberg	  Select to build support for Intel Low Power Subsystem such as
6273d48aab1SMika Westerberg	  found on Intel Lynxpoint PCH. Selecting this option enables
6280f531431SMathias Nyman	  things like clock tree (common clock framework) and pincontrol
6290f531431SMathias Nyman	  which are needed by the LPSS peripheral drivers.
6303d48aab1SMika Westerberg
63192082a88SKen Xueconfig X86_AMD_PLATFORM_DEVICE
63292082a88SKen Xue	bool "AMD ACPI2Platform devices support"
63392082a88SKen Xue	depends on ACPI
63492082a88SKen Xue	select COMMON_CLK
63592082a88SKen Xue	select PINCTRL
63692082a88SKen Xue	---help---
63792082a88SKen Xue	  Select to interpret AMD specific ACPI device to platform device
63892082a88SKen Xue	  such as I2C, UART, GPIO found on AMD Carrizo and later chipsets.
63992082a88SKen Xue	  I2C and UART depend on COMMON_CLK to set clock. GPIO driver is
64092082a88SKen Xue	  implemented under PINCTRL subsystem.
64192082a88SKen Xue
642ced3ce76SDavid E. Boxconfig IOSF_MBI
643ced3ce76SDavid E. Box	tristate "Intel SoC IOSF Sideband support for SoC platforms"
644ced3ce76SDavid E. Box	depends on PCI
645ced3ce76SDavid E. Box	---help---
646ced3ce76SDavid E. Box	  This option enables sideband register access support for Intel SoC
647ced3ce76SDavid E. Box	  platforms. On these platforms the IOSF sideband is used in lieu of
648ced3ce76SDavid E. Box	  MSR's for some register accesses, mostly but not limited to thermal
649ced3ce76SDavid E. Box	  and power. Drivers may query the availability of this device to
650ced3ce76SDavid E. Box	  determine if they need the sideband in order to work on these
651ced3ce76SDavid E. Box	  platforms. The sideband is available on the following SoC products.
652ced3ce76SDavid E. Box	  This list is not meant to be exclusive.
653ced3ce76SDavid E. Box	   - BayTrail
654ced3ce76SDavid E. Box	   - Braswell
655ced3ce76SDavid E. Box	   - Quark
656ced3ce76SDavid E. Box
657ced3ce76SDavid E. Box	  You should say Y if you are running a kernel on one of these SoC's.
658ced3ce76SDavid E. Box
659ed2226bdSDavid E. Boxconfig IOSF_MBI_DEBUG
660ed2226bdSDavid E. Box	bool "Enable IOSF sideband access through debugfs"
661ed2226bdSDavid E. Box	depends on IOSF_MBI && DEBUG_FS
662ed2226bdSDavid E. Box	---help---
663ed2226bdSDavid E. Box	  Select this option to expose the IOSF sideband access registers (MCR,
664ed2226bdSDavid E. Box	  MDR, MCRX) through debugfs to write and read register information from
665ed2226bdSDavid E. Box	  different units on the SoC. This is most useful for obtaining device
666ed2226bdSDavid E. Box	  state information for debug and analysis. As this is a general access
667ed2226bdSDavid E. Box	  mechanism, users of this option would have specific knowledge of the
668ed2226bdSDavid E. Box	  device they want to access.
669ed2226bdSDavid E. Box
670ed2226bdSDavid E. Box	  If you don't require the option or are in doubt, say N.
671ed2226bdSDavid E. Box
672c5c606d9SRavikiran G Thirumalaiconfig X86_RDC321X
673c5c606d9SRavikiran G Thirumalai	bool "RDC R-321x SoC"
674506f1d07SSam Ravnborg	depends on X86_32
675c5c606d9SRavikiran G Thirumalai	depends on X86_EXTENDED_PLATFORM
676c5c606d9SRavikiran G Thirumalai	select M486
677c5c606d9SRavikiran G Thirumalai	select X86_REBOOTFIXUPS
678c5c606d9SRavikiran G Thirumalai	---help---
679c5c606d9SRavikiran G Thirumalai	  This option is needed for RDC R-321x system-on-chip, also known
680c5c606d9SRavikiran G Thirumalai	  as R-8610-(G).
681c5c606d9SRavikiran G Thirumalai	  If you don't have one of these chips, you should say N here.
682c5c606d9SRavikiran G Thirumalai
683e0c7ae37SIngo Molnarconfig X86_32_NON_STANDARD
6849c398017SIngo Molnar	bool "Support non-standard 32-bit SMP architectures"
6859c398017SIngo Molnar	depends on X86_32 && SMP
686c5c606d9SRavikiran G Thirumalai	depends on X86_EXTENDED_PLATFORM
6878f9ca475SIngo Molnar	---help---
688b5660ba7SH. Peter Anvin	  This option compiles in the bigsmp and STA2X11 default
689b5660ba7SH. Peter Anvin	  subarchitectures.  It is intended for a generic binary
690b5660ba7SH. Peter Anvin	  kernel. If you select them all, kernel will probe it one by
691b5660ba7SH. Peter Anvin	  one and will fallback to default.
692d49c4288SYinghai Lu
693c5c606d9SRavikiran G Thirumalai# Alphabetically sorted list of Non standard 32 bit platforms
694d49c4288SYinghai Lu
695d949f36fSLinus Torvaldsconfig X86_SUPPORTS_MEMORY_FAILURE
6966fc108a0SJan Beulich	def_bool y
697d949f36fSLinus Torvalds	# MCE code calls memory_failure():
698d949f36fSLinus Torvalds	depends on X86_MCE
699d949f36fSLinus Torvalds	# On 32-bit this adds too big of NODES_SHIFT and we run out of page flags:
700d949f36fSLinus Torvalds	# On 32-bit SPARSEMEM adds too big of SECTIONS_WIDTH:
701d949f36fSLinus Torvalds	depends on X86_64 || !SPARSEMEM
702d949f36fSLinus Torvalds	select ARCH_SUPPORTS_MEMORY_FAILURE
703d949f36fSLinus Torvalds
70483125a3aSAlessandro Rubiniconfig STA2X11
70583125a3aSAlessandro Rubini	bool "STA2X11 Companion Chip Support"
70683125a3aSAlessandro Rubini	depends on X86_32_NON_STANDARD && PCI
707b6e05477SChristoph Hellwig	select ARCH_HAS_PHYS_TO_DMA
70883125a3aSAlessandro Rubini	select X86_DEV_DMA_OPS
70983125a3aSAlessandro Rubini	select X86_DMA_REMAP
71083125a3aSAlessandro Rubini	select SWIOTLB
71183125a3aSAlessandro Rubini	select MFD_STA2X11
7120145071bSLinus Walleij	select GPIOLIB
71383125a3aSAlessandro Rubini	---help---
71483125a3aSAlessandro Rubini	  This adds support for boards based on the STA2X11 IO-Hub,
71583125a3aSAlessandro Rubini	  a.k.a. "ConneXt". The chip is used in place of the standard
71683125a3aSAlessandro Rubini	  PC chipset, so all "standard" peripherals are missing. If this
71783125a3aSAlessandro Rubini	  option is selected the kernel will still be able to boot on
71883125a3aSAlessandro Rubini	  standard PC machines.
71983125a3aSAlessandro Rubini
72082148d1dSShérabconfig X86_32_IRIS
72182148d1dSShérab	tristate "Eurobraille/Iris poweroff module"
72282148d1dSShérab	depends on X86_32
72382148d1dSShérab	---help---
72482148d1dSShérab	  The Iris machines from EuroBraille do not have APM or ACPI support
72582148d1dSShérab	  to shut themselves down properly.  A special I/O sequence is
72682148d1dSShérab	  needed to do so, which is what this module does at
72782148d1dSShérab	  kernel shutdown.
72882148d1dSShérab
72982148d1dSShérab	  This is only for Iris machines from EuroBraille.
73082148d1dSShérab
73182148d1dSShérab	  If unused, say N.
73282148d1dSShérab
733ae1e9130SIngo Molnarconfig SCHED_OMIT_FRAME_POINTER
7343c2362e6SHarvey Harrison	def_bool y
7353c2362e6SHarvey Harrison	prompt "Single-depth WCHAN output"
736a87d0914SKen Chen	depends on X86
7378f9ca475SIngo Molnar	---help---
738506f1d07SSam Ravnborg	  Calculate simpler /proc/<PID>/wchan values. If this option
739506f1d07SSam Ravnborg	  is disabled then wchan values will recurse back to the
740506f1d07SSam Ravnborg	  caller function. This provides more accurate wchan values,
741506f1d07SSam Ravnborg	  at the expense of slightly more scheduling overhead.
742506f1d07SSam Ravnborg
743506f1d07SSam Ravnborg	  If in doubt, say "Y".
744506f1d07SSam Ravnborg
7456276a074SBorislav Petkovmenuconfig HYPERVISOR_GUEST
7466276a074SBorislav Petkov	bool "Linux guest support"
7478f9ca475SIngo Molnar	---help---
7486276a074SBorislav Petkov	  Say Y here to enable options for running Linux under various hyper-
7496276a074SBorislav Petkov	  visors. This option enables basic hypervisor detection and platform
7506276a074SBorislav Petkov	  setup.
751506f1d07SSam Ravnborg
7526276a074SBorislav Petkov	  If you say N, all options in this submenu will be skipped and
7536276a074SBorislav Petkov	  disabled, and Linux guest support won't be built in.
754506f1d07SSam Ravnborg
7556276a074SBorislav Petkovif HYPERVISOR_GUEST
756506f1d07SSam Ravnborg
757e61bd94aSEduardo Pereira Habkostconfig PARAVIRT
758e61bd94aSEduardo Pereira Habkost	bool "Enable paravirtualization code"
7598f9ca475SIngo Molnar	---help---
760e61bd94aSEduardo Pereira Habkost	  This changes the kernel so it can modify itself when it is run
761e61bd94aSEduardo Pereira Habkost	  under a hypervisor, potentially improving performance significantly
762e61bd94aSEduardo Pereira Habkost	  over full virtualization.  However, when run without a hypervisor
763e61bd94aSEduardo Pereira Habkost	  the kernel is theoretically slower and slightly larger.
764e61bd94aSEduardo Pereira Habkost
765c00a280aSJuergen Grossconfig PARAVIRT_XXL
766c00a280aSJuergen Gross	bool
767c00a280aSJuergen Gross
7686276a074SBorislav Petkovconfig PARAVIRT_DEBUG
7696276a074SBorislav Petkov	bool "paravirt-ops debugging"
7706276a074SBorislav Petkov	depends on PARAVIRT && DEBUG_KERNEL
7716276a074SBorislav Petkov	---help---
7726276a074SBorislav Petkov	  Enable to debug paravirt_ops internals.  Specifically, BUG if
7736276a074SBorislav Petkov	  a paravirt_op is missing when it is called.
7746276a074SBorislav Petkov
775b4ecc126SJeremy Fitzhardingeconfig PARAVIRT_SPINLOCKS
776b4ecc126SJeremy Fitzhardinge	bool "Paravirtualization layer for spinlocks"
7776ea30386SKees Cook	depends on PARAVIRT && SMP
778b4ecc126SJeremy Fitzhardinge	---help---
779b4ecc126SJeremy Fitzhardinge	  Paravirtualized spinlocks allow a pvops backend to replace the
780b4ecc126SJeremy Fitzhardinge	  spinlock implementation with something virtualization-friendly
781b4ecc126SJeremy Fitzhardinge	  (for example, block the virtual CPU rather than spinning).
782b4ecc126SJeremy Fitzhardinge
7834c4e4f61SRaghavendra K T	  It has a minimal impact on native kernels and gives a nice performance
7844c4e4f61SRaghavendra K T	  benefit on paravirtualized KVM / Xen kernels.
785b4ecc126SJeremy Fitzhardinge
7864c4e4f61SRaghavendra K T	  If you are unsure how to answer this question, answer Y.
787b4ecc126SJeremy Fitzhardinge
78845e898b7SWaiman Longconfig QUEUED_LOCK_STAT
78945e898b7SWaiman Long	bool "Paravirt queued spinlock statistics"
790cfd8983fSPeter Zijlstra	depends on PARAVIRT_SPINLOCKS && DEBUG_FS
79145e898b7SWaiman Long	---help---
79245e898b7SWaiman Long	  Enable the collection of statistical data on the slowpath
79345e898b7SWaiman Long	  behavior of paravirtualized queued spinlocks and report
79445e898b7SWaiman Long	  them on debugfs.
79545e898b7SWaiman Long
7966276a074SBorislav Petkovsource "arch/x86/xen/Kconfig"
7976276a074SBorislav Petkov
7986276a074SBorislav Petkovconfig KVM_GUEST
7996276a074SBorislav Petkov	bool "KVM Guest support (including kvmclock)"
8006276a074SBorislav Petkov	depends on PARAVIRT
8016276a074SBorislav Petkov	select PARAVIRT_CLOCK
8026276a074SBorislav Petkov	default y
8036276a074SBorislav Petkov	---help---
8046276a074SBorislav Petkov	  This option enables various optimizations for running under the KVM
8056276a074SBorislav Petkov	  hypervisor. It includes a paravirtualized clock, so that instead
8066276a074SBorislav Petkov	  of relying on a PIT (or probably other) emulation by the
8076276a074SBorislav Petkov	  underlying device model, the host provides the guest with
8086276a074SBorislav Petkov	  timing infrastructure such as time of day, and system time
8096276a074SBorislav Petkov
8107733607fSMaran Wilsonconfig PVH
8117733607fSMaran Wilson	bool "Support for running PVH guests"
8127733607fSMaran Wilson	---help---
8137733607fSMaran Wilson	  This option enables the PVH entry point for guest virtual machines
8147733607fSMaran Wilson	  as specified in the x86/HVM direct boot ABI.
8157733607fSMaran Wilson
8161e20eb85SSrivatsa Vaddagiriconfig KVM_DEBUG_FS
8171e20eb85SSrivatsa Vaddagiri	bool "Enable debug information for KVM Guests in debugfs"
8181e20eb85SSrivatsa Vaddagiri	depends on KVM_GUEST && DEBUG_FS
8191e20eb85SSrivatsa Vaddagiri	---help---
8201e20eb85SSrivatsa Vaddagiri	  This option enables collection of various statistics for KVM guest.
8211e20eb85SSrivatsa Vaddagiri	  Statistics are displayed in debugfs filesystem. Enabling this option
8221e20eb85SSrivatsa Vaddagiri	  may incur significant overhead.
8231e20eb85SSrivatsa Vaddagiri
8246276a074SBorislav Petkovconfig PARAVIRT_TIME_ACCOUNTING
8256276a074SBorislav Petkov	bool "Paravirtual steal time accounting"
8266276a074SBorislav Petkov	depends on PARAVIRT
8276276a074SBorislav Petkov	---help---
8286276a074SBorislav Petkov	  Select this option to enable fine granularity task steal time
8296276a074SBorislav Petkov	  accounting. Time spent executing other tasks in parallel with
8306276a074SBorislav Petkov	  the current vCPU is discounted from the vCPU power. To account for
8316276a074SBorislav Petkov	  that, there can be a small performance impact.
8326276a074SBorislav Petkov
8336276a074SBorislav Petkov	  If in doubt, say N here.
8346276a074SBorislav Petkov
8357af192c9SGerd Hoffmannconfig PARAVIRT_CLOCK
8367af192c9SGerd Hoffmann	bool
8377af192c9SGerd Hoffmann
8384a362601SJan Kiszkaconfig JAILHOUSE_GUEST
8394a362601SJan Kiszka	bool "Jailhouse non-root cell support"
840abde587bSArnd Bergmann	depends on X86_64 && PCI
84187e65d05SJan Kiszka	select X86_PM_TIMER
8424a362601SJan Kiszka	---help---
8434a362601SJan Kiszka	  This option allows to run Linux as guest in a Jailhouse non-root
8444a362601SJan Kiszka	  cell. You can leave this option disabled if you only want to start
8454a362601SJan Kiszka	  Jailhouse and run Linux afterwards in the root cell.
8464a362601SJan Kiszka
8476276a074SBorislav Petkovendif #HYPERVISOR_GUEST
84897349135SJeremy Fitzhardinge
849506f1d07SSam Ravnborgsource "arch/x86/Kconfig.cpu"
850506f1d07SSam Ravnborg
851506f1d07SSam Ravnborgconfig HPET_TIMER
8523c2362e6SHarvey Harrison	def_bool X86_64
853506f1d07SSam Ravnborg	prompt "HPET Timer Support" if X86_32
8548f9ca475SIngo Molnar	---help---
855506f1d07SSam Ravnborg	  Use the IA-PC HPET (High Precision Event Timer) to manage
856506f1d07SSam Ravnborg	  time in preference to the PIT and RTC, if a HPET is
857506f1d07SSam Ravnborg	  present.
858506f1d07SSam Ravnborg	  HPET is the next generation timer replacing legacy 8254s.
859506f1d07SSam Ravnborg	  The HPET provides a stable time base on SMP
860506f1d07SSam Ravnborg	  systems, unlike the TSC, but it is more expensive to access,
8614e7f9df2SMichael S. Tsirkin	  as it is off-chip.  The interface used is documented
8624e7f9df2SMichael S. Tsirkin	  in the HPET spec, revision 1.
863506f1d07SSam Ravnborg
864506f1d07SSam Ravnborg	  You can safely choose Y here.  However, HPET will only be
865506f1d07SSam Ravnborg	  activated if the platform and the BIOS support this feature.
866506f1d07SSam Ravnborg	  Otherwise the 8254 will be used for timing services.
867506f1d07SSam Ravnborg
868506f1d07SSam Ravnborg	  Choose N to continue using the legacy 8254 timer.
869506f1d07SSam Ravnborg
870506f1d07SSam Ravnborgconfig HPET_EMULATE_RTC
8713c2362e6SHarvey Harrison	def_bool y
8729d8af78bSBernhard Walle	depends on HPET_TIMER && (RTC=y || RTC=m || RTC_DRV_CMOS=m || RTC_DRV_CMOS=y)
873506f1d07SSam Ravnborg
874bb24c471SJacob Panconfig APB_TIMER
875933b9463SAlan Cox       def_bool y if X86_INTEL_MID
876933b9463SAlan Cox       prompt "Intel MID APB Timer Support" if X86_INTEL_MID
87706c3df49SJamie Iles       select DW_APB_TIMER
878a0c3832aSAlan Cox       depends on X86_INTEL_MID && SFI
879bb24c471SJacob Pan       help
880bb24c471SJacob Pan         APB timer is the replacement for 8254, HPET on X86 MID platforms.
881bb24c471SJacob Pan         The APBT provides a stable time base on SMP
882bb24c471SJacob Pan         systems, unlike the TSC, but it is more expensive to access,
883bb24c471SJacob Pan         as it is off-chip. APB timers are always running regardless of CPU
884bb24c471SJacob Pan         C states, they are used as per CPU clockevent device when possible.
885bb24c471SJacob Pan
8866a108a14SDavid Rientjes# Mark as expert because too many people got it wrong.
887506f1d07SSam Ravnborg# The code disables itself when not needed.
8887ae9392cSThomas Petazzoniconfig DMI
8897ae9392cSThomas Petazzoni	default y
890cf074402SArd Biesheuvel	select DMI_SCAN_MACHINE_NON_EFI_FALLBACK
8916a108a14SDavid Rientjes	bool "Enable DMI scanning" if EXPERT
8928f9ca475SIngo Molnar	---help---
8937ae9392cSThomas Petazzoni	  Enabled scanning of DMI to identify machine quirks. Say Y
8947ae9392cSThomas Petazzoni	  here unless you have verified that your setup is not
8957ae9392cSThomas Petazzoni	  affected by entries in the DMI blacklist. Required by PNP
8967ae9392cSThomas Petazzoni	  BIOS code.
8977ae9392cSThomas Petazzoni
898506f1d07SSam Ravnborgconfig GART_IOMMU
89938901f1cSAndi Kleen	bool "Old AMD GART IOMMU support"
900a4ce5a48SChristoph Hellwig	select IOMMU_HELPER
901506f1d07SSam Ravnborg	select SWIOTLB
90223ac4ae8SAndreas Herrmann	depends on X86_64 && PCI && AMD_NB
9038f9ca475SIngo Molnar	---help---
904ced3c42cSIngo Molnar	  Provides a driver for older AMD Athlon64/Opteron/Turion/Sempron
905ced3c42cSIngo Molnar	  GART based hardware IOMMUs.
906ced3c42cSIngo Molnar
907ced3c42cSIngo Molnar	  The GART supports full DMA access for devices with 32-bit access
908ced3c42cSIngo Molnar	  limitations, on systems with more than 3 GB. This is usually needed
909ced3c42cSIngo Molnar	  for USB, sound, many IDE/SATA chipsets and some other devices.
910ced3c42cSIngo Molnar
911ced3c42cSIngo Molnar	  Newer systems typically have a modern AMD IOMMU, supported via
912ced3c42cSIngo Molnar	  the CONFIG_AMD_IOMMU=y config option.
913ced3c42cSIngo Molnar
914ced3c42cSIngo Molnar	  In normal configurations this driver is only active when needed:
915ced3c42cSIngo Molnar	  there's more than 3 GB of memory and the system contains a
916ced3c42cSIngo Molnar	  32-bit limited device.
917ced3c42cSIngo Molnar
918ced3c42cSIngo Molnar	  If unsure, say Y.
919506f1d07SSam Ravnborg
920506f1d07SSam Ravnborgconfig CALGARY_IOMMU
921506f1d07SSam Ravnborg	bool "IBM Calgary IOMMU support"
922a4ce5a48SChristoph Hellwig	select IOMMU_HELPER
923506f1d07SSam Ravnborg	select SWIOTLB
9246ea30386SKees Cook	depends on X86_64 && PCI
9258f9ca475SIngo Molnar	---help---
926506f1d07SSam Ravnborg	  Support for hardware IOMMUs in IBM's xSeries x366 and x460
927506f1d07SSam Ravnborg	  systems. Needed to run systems with more than 3GB of memory
928506f1d07SSam Ravnborg	  properly with 32-bit PCI devices that do not support DAC
929506f1d07SSam Ravnborg	  (Double Address Cycle). Calgary also supports bus level
930506f1d07SSam Ravnborg	  isolation, where all DMAs pass through the IOMMU.  This
931506f1d07SSam Ravnborg	  prevents them from going anywhere except their intended
932506f1d07SSam Ravnborg	  destination. This catches hard-to-find kernel bugs and
933506f1d07SSam Ravnborg	  mis-behaving drivers and devices that do not use the DMA-API
934506f1d07SSam Ravnborg	  properly to set up their DMA buffers.  The IOMMU can be
935506f1d07SSam Ravnborg	  turned off at boot time with the iommu=off parameter.
936506f1d07SSam Ravnborg	  Normally the kernel will make the right choice by itself.
937506f1d07SSam Ravnborg	  If unsure, say Y.
938506f1d07SSam Ravnborg
939506f1d07SSam Ravnborgconfig CALGARY_IOMMU_ENABLED_BY_DEFAULT
9403c2362e6SHarvey Harrison	def_bool y
9413c2362e6SHarvey Harrison	prompt "Should Calgary be enabled by default?"
942506f1d07SSam Ravnborg	depends on CALGARY_IOMMU
9438f9ca475SIngo Molnar	---help---
944506f1d07SSam Ravnborg	  Should Calgary be enabled by default? if you choose 'y', Calgary
945506f1d07SSam Ravnborg	  will be used (if it exists). If you choose 'n', Calgary will not be
946506f1d07SSam Ravnborg	  used even if it exists. If you choose 'n' and would like to use
947506f1d07SSam Ravnborg	  Calgary anyway, pass 'iommu=calgary' on the kernel command line.
948506f1d07SSam Ravnborg	  If unsure, say Y.
949506f1d07SSam Ravnborg
9501184dc2fSMike Travisconfig MAXSMP
951ddb0c5a6SSamuel Thibault	bool "Enable Maximum number of SMP Processors and NUMA Nodes"
9526ea30386SKees Cook	depends on X86_64 && SMP && DEBUG_KERNEL
95336f5101aSMike Travis	select CPUMASK_OFFSTACK
9548f9ca475SIngo Molnar	---help---
955ddb0c5a6SSamuel Thibault	  Enable maximum number of CPUS and NUMA Nodes for this architecture.
9561184dc2fSMike Travis	  If unsure, say N.
957506f1d07SSam Ravnborg
958aec6487eSIngo Molnar#
959aec6487eSIngo Molnar# The maximum number of CPUs supported:
960aec6487eSIngo Molnar#
961aec6487eSIngo Molnar# The main config value is NR_CPUS, which defaults to NR_CPUS_DEFAULT,
962aec6487eSIngo Molnar# and which can be configured interactively in the
963aec6487eSIngo Molnar# [NR_CPUS_RANGE_BEGIN ... NR_CPUS_RANGE_END] range.
964aec6487eSIngo Molnar#
965aec6487eSIngo Molnar# The ranges are different on 32-bit and 64-bit kernels, depending on
966aec6487eSIngo Molnar# hardware capabilities and scalability features of the kernel.
967aec6487eSIngo Molnar#
968aec6487eSIngo Molnar# ( If MAXSMP is enabled we just use the highest possible value and disable
969aec6487eSIngo Molnar#   interactive configuration. )
970aec6487eSIngo Molnar#
971a0d0bb4dSRandy Dunlap
972aec6487eSIngo Molnarconfig NR_CPUS_RANGE_BEGIN
973a0d0bb4dSRandy Dunlap	int
974aec6487eSIngo Molnar	default NR_CPUS_RANGE_END if MAXSMP
975a0d0bb4dSRandy Dunlap	default    1 if !SMP
976a0d0bb4dSRandy Dunlap	default    2
977a0d0bb4dSRandy Dunlap
978aec6487eSIngo Molnarconfig NR_CPUS_RANGE_END
979a0d0bb4dSRandy Dunlap	int
980a0d0bb4dSRandy Dunlap	depends on X86_32
981aec6487eSIngo Molnar	default   64 if  SMP &&  X86_BIGSMP
982aec6487eSIngo Molnar	default    8 if  SMP && !X86_BIGSMP
983a0d0bb4dSRandy Dunlap	default    1 if !SMP
984a0d0bb4dSRandy Dunlap
985aec6487eSIngo Molnarconfig NR_CPUS_RANGE_END
986a0d0bb4dSRandy Dunlap	int
987a0d0bb4dSRandy Dunlap	depends on X86_64
988aec6487eSIngo Molnar	default 8192 if  SMP && ( MAXSMP ||  CPUMASK_OFFSTACK)
989aec6487eSIngo Molnar	default  512 if  SMP && (!MAXSMP && !CPUMASK_OFFSTACK)
990a0d0bb4dSRandy Dunlap	default    1 if !SMP
991aec6487eSIngo Molnar
992aec6487eSIngo Molnarconfig NR_CPUS_DEFAULT
993aec6487eSIngo Molnar	int
994aec6487eSIngo Molnar	depends on X86_32
995aec6487eSIngo Molnar	default   32 if  X86_BIGSMP
996aec6487eSIngo Molnar	default    8 if  SMP
997aec6487eSIngo Molnar	default    1 if !SMP
998aec6487eSIngo Molnar
999aec6487eSIngo Molnarconfig NR_CPUS_DEFAULT
1000aec6487eSIngo Molnar	int
1001aec6487eSIngo Molnar	depends on X86_64
1002a0d0bb4dSRandy Dunlap	default 8192 if  MAXSMP
1003a0d0bb4dSRandy Dunlap	default   64 if  SMP
1004aec6487eSIngo Molnar	default    1 if !SMP
1005a0d0bb4dSRandy Dunlap
1006506f1d07SSam Ravnborgconfig NR_CPUS
100736f5101aSMike Travis	int "Maximum number of CPUs" if SMP && !MAXSMP
1008aec6487eSIngo Molnar	range NR_CPUS_RANGE_BEGIN NR_CPUS_RANGE_END
1009aec6487eSIngo Molnar	default NR_CPUS_DEFAULT
10108f9ca475SIngo Molnar	---help---
1011506f1d07SSam Ravnborg	  This allows you to specify the maximum number of CPUs which this
1012bb61ccc7SJosh Boyer	  kernel will support.  If CPUMASK_OFFSTACK is enabled, the maximum
1013cad14bb9SKirill A. Shutemov	  supported value is 8192, otherwise the maximum value is 512.  The
1014506f1d07SSam Ravnborg	  minimum value which makes sense is 2.
1015506f1d07SSam Ravnborg
1016aec6487eSIngo Molnar	  This is purely to save memory: each supported CPU adds about 8KB
1017aec6487eSIngo Molnar	  to the kernel image.
1018506f1d07SSam Ravnborg
1019506f1d07SSam Ravnborgconfig SCHED_SMT
1020dbe73364SThomas Gleixner	def_bool y if SMP
1021506f1d07SSam Ravnborg
1022506f1d07SSam Ravnborgconfig SCHED_MC
10233c2362e6SHarvey Harrison	def_bool y
10243c2362e6SHarvey Harrison	prompt "Multi-core scheduler support"
1025c8e56d20SBorislav Petkov	depends on SMP
10268f9ca475SIngo Molnar	---help---
1027506f1d07SSam Ravnborg	  Multi-core scheduler support improves the CPU scheduler's decision
1028506f1d07SSam Ravnborg	  making when dealing with multi-core CPU chips at a cost of slightly
1029506f1d07SSam Ravnborg	  increased overhead in some places. If unsure say N here.
1030506f1d07SSam Ravnborg
1031de966cf4STim Chenconfig SCHED_MC_PRIO
1032de966cf4STim Chen	bool "CPU core priorities scheduler support"
10330a21fc12SIngo Molnar	depends on SCHED_MC && CPU_SUP_INTEL
10340a21fc12SIngo Molnar	select X86_INTEL_PSTATE
10350a21fc12SIngo Molnar	select CPU_FREQ
1036de966cf4STim Chen	default y
10375e76b2abSTim Chen	---help---
1038de966cf4STim Chen	  Intel Turbo Boost Max Technology 3.0 enabled CPUs have a
1039de966cf4STim Chen	  core ordering determined at manufacturing time, which allows
1040de966cf4STim Chen	  certain cores to reach higher turbo frequencies (when running
1041de966cf4STim Chen	  single threaded workloads) than others.
1042de966cf4STim Chen
1043de966cf4STim Chen	  Enabling this kernel feature teaches the scheduler about
1044de966cf4STim Chen	  the TBM3 (aka ITMT) priority order of the CPU cores and adjusts the
1045de966cf4STim Chen	  scheduler's CPU selection logic accordingly, so that higher
1046de966cf4STim Chen	  overall system performance can be achieved.
1047de966cf4STim Chen
1048de966cf4STim Chen	  This feature will have no effect on CPUs without this feature.
1049de966cf4STim Chen
1050de966cf4STim Chen	  If unsure say Y here.
10515e76b2abSTim Chen
105230b8b006SThomas Gleixnerconfig UP_LATE_INIT
105330b8b006SThomas Gleixner       def_bool y
1054ba360f88SThomas Gleixner       depends on !SMP && X86_LOCAL_APIC
105530b8b006SThomas Gleixner
1056506f1d07SSam Ravnborgconfig X86_UP_APIC
105750849eefSJan Beulich	bool "Local APIC support on uniprocessors" if !PCI_MSI
105850849eefSJan Beulich	default PCI_MSI
105938a1dfdaSBryan O'Donoghue	depends on X86_32 && !SMP && !X86_32_NON_STANDARD
10608f9ca475SIngo Molnar	---help---
1061506f1d07SSam Ravnborg	  A local APIC (Advanced Programmable Interrupt Controller) is an
1062506f1d07SSam Ravnborg	  integrated interrupt controller in the CPU. If you have a single-CPU
1063506f1d07SSam Ravnborg	  system which has a processor with a local APIC, you can say Y here to
1064506f1d07SSam Ravnborg	  enable and use it. If you say Y here even though your machine doesn't
1065506f1d07SSam Ravnborg	  have a local APIC, then the kernel will still run with no slowdown at
1066506f1d07SSam Ravnborg	  all. The local APIC supports CPU-generated self-interrupts (timer,
1067506f1d07SSam Ravnborg	  performance counters), and the NMI watchdog which detects hard
1068506f1d07SSam Ravnborg	  lockups.
1069506f1d07SSam Ravnborg
1070506f1d07SSam Ravnborgconfig X86_UP_IOAPIC
1071506f1d07SSam Ravnborg	bool "IO-APIC support on uniprocessors"
1072506f1d07SSam Ravnborg	depends on X86_UP_APIC
10738f9ca475SIngo Molnar	---help---
1074506f1d07SSam Ravnborg	  An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an
1075506f1d07SSam Ravnborg	  SMP-capable replacement for PC-style interrupt controllers. Most
1076506f1d07SSam Ravnborg	  SMP systems and many recent uniprocessor systems have one.
1077506f1d07SSam Ravnborg
1078506f1d07SSam Ravnborg	  If you have a single-CPU system with an IO-APIC, you can say Y here
1079506f1d07SSam Ravnborg	  to use it. If you say Y here even though your machine doesn't have
1080506f1d07SSam Ravnborg	  an IO-APIC, then the kernel will still run with no slowdown at all.
1081506f1d07SSam Ravnborg
1082506f1d07SSam Ravnborgconfig X86_LOCAL_APIC
10833c2362e6SHarvey Harrison	def_bool y
10840dbc6078SThomas Petazzoni	depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC || PCI_MSI
1085b5dc8e6cSJiang Liu	select IRQ_DOMAIN_HIERARCHY
108652f518a3SJiang Liu	select PCI_MSI_IRQ_DOMAIN if PCI_MSI
1087506f1d07SSam Ravnborg
1088506f1d07SSam Ravnborgconfig X86_IO_APIC
1089b1da1e71SJan Beulich	def_bool y
1090b1da1e71SJan Beulich	depends on X86_LOCAL_APIC || X86_UP_IOAPIC
1091506f1d07SSam Ravnborg
109241b9eb26SStefan Assmannconfig X86_REROUTE_FOR_BROKEN_BOOT_IRQS
109341b9eb26SStefan Assmann	bool "Reroute for broken boot IRQs"
109441b9eb26SStefan Assmann	depends on X86_IO_APIC
10958f9ca475SIngo Molnar	---help---
109641b9eb26SStefan Assmann	  This option enables a workaround that fixes a source of
109741b9eb26SStefan Assmann	  spurious interrupts. This is recommended when threaded
109841b9eb26SStefan Assmann	  interrupt handling is used on systems where the generation of
109941b9eb26SStefan Assmann	  superfluous "boot interrupts" cannot be disabled.
110041b9eb26SStefan Assmann
110141b9eb26SStefan Assmann	  Some chipsets generate a legacy INTx "boot IRQ" when the IRQ
110241b9eb26SStefan Assmann	  entry in the chipset's IO-APIC is masked (as, e.g. the RT
110341b9eb26SStefan Assmann	  kernel does during interrupt handling). On chipsets where this
110441b9eb26SStefan Assmann	  boot IRQ generation cannot be disabled, this workaround keeps
110541b9eb26SStefan Assmann	  the original IRQ line masked so that only the equivalent "boot
110641b9eb26SStefan Assmann	  IRQ" is delivered to the CPUs. The workaround also tells the
110741b9eb26SStefan Assmann	  kernel to set up the IRQ handler on the boot IRQ line. In this
110841b9eb26SStefan Assmann	  way only one interrupt is delivered to the kernel. Otherwise
110941b9eb26SStefan Assmann	  the spurious second interrupt may cause the kernel to bring
111041b9eb26SStefan Assmann	  down (vital) interrupt lines.
111141b9eb26SStefan Assmann
111241b9eb26SStefan Assmann	  Only affects "broken" chipsets. Interrupt sharing may be
111341b9eb26SStefan Assmann	  increased on these systems.
111441b9eb26SStefan Assmann
1115506f1d07SSam Ravnborgconfig X86_MCE
1116bab9bc65SAndi Kleen	bool "Machine Check / overheating reporting"
1117648ed940SChen, Gong	select GENERIC_ALLOCATOR
1118e57dbaf7SBorislav Petkov	default y
1119506f1d07SSam Ravnborg	---help---
1120bab9bc65SAndi Kleen	  Machine Check support allows the processor to notify the
1121bab9bc65SAndi Kleen	  kernel if it detects a problem (e.g. overheating, data corruption).
1122506f1d07SSam Ravnborg	  The action the kernel takes depends on the severity of the problem,
1123bab9bc65SAndi Kleen	  ranging from warning messages to halting the machine.
11244efc0670SAndi Kleen
11255de97c9fSTony Luckconfig X86_MCELOG_LEGACY
11265de97c9fSTony Luck	bool "Support for deprecated /dev/mcelog character device"
11275de97c9fSTony Luck	depends on X86_MCE
11285de97c9fSTony Luck	---help---
11295de97c9fSTony Luck	  Enable support for /dev/mcelog which is needed by the old mcelog
11305de97c9fSTony Luck	  userspace logging daemon. Consider switching to the new generation
11315de97c9fSTony Luck	  rasdaemon solution.
11325de97c9fSTony Luck
1133506f1d07SSam Ravnborgconfig X86_MCE_INTEL
11343c2362e6SHarvey Harrison	def_bool y
11353c2362e6SHarvey Harrison	prompt "Intel MCE features"
1136c1ebf835SAndi Kleen	depends on X86_MCE && X86_LOCAL_APIC
11378f9ca475SIngo Molnar	---help---
1138506f1d07SSam Ravnborg	   Additional support for intel specific MCE features such as
1139506f1d07SSam Ravnborg	   the thermal monitor.
1140506f1d07SSam Ravnborg
1141506f1d07SSam Ravnborgconfig X86_MCE_AMD
11423c2362e6SHarvey Harrison	def_bool y
11433c2362e6SHarvey Harrison	prompt "AMD MCE features"
1144f5382de9SYazen Ghannam	depends on X86_MCE && X86_LOCAL_APIC && AMD_NB
11458f9ca475SIngo Molnar	---help---
1146506f1d07SSam Ravnborg	   Additional support for AMD specific MCE features such as
1147506f1d07SSam Ravnborg	   the DRAM Error Threshold.
1148506f1d07SSam Ravnborg
11494efc0670SAndi Kleenconfig X86_ANCIENT_MCE
11506fc108a0SJan Beulich	bool "Support for old Pentium 5 / WinChip machine checks"
1151c31d9633SAndi Kleen	depends on X86_32 && X86_MCE
11524efc0670SAndi Kleen	---help---
11534efc0670SAndi Kleen	  Include support for machine check handling on old Pentium 5 or WinChip
11545065a706SMasanari Iida	  systems. These typically need to be enabled explicitly on the command
11554efc0670SAndi Kleen	  line.
11564efc0670SAndi Kleen
1157b2762686SAndi Kleenconfig X86_MCE_THRESHOLD
1158b2762686SAndi Kleen	depends on X86_MCE_AMD || X86_MCE_INTEL
11596fc108a0SJan Beulich	def_bool y
1160b2762686SAndi Kleen
1161ea149b36SAndi Kleenconfig X86_MCE_INJECT
1162bc8e80d5SBorislav Petkov	depends on X86_MCE && X86_LOCAL_APIC && DEBUG_FS
1163ea149b36SAndi Kleen	tristate "Machine check injector support"
1164ea149b36SAndi Kleen	---help---
1165ea149b36SAndi Kleen	  Provide support for injecting machine checks for testing purposes.
1166ea149b36SAndi Kleen	  If you don't know what a machine check is and you don't do kernel
1167ea149b36SAndi Kleen	  QA it is safe to say n.
1168ea149b36SAndi Kleen
11694efc0670SAndi Kleenconfig X86_THERMAL_VECTOR
11704efc0670SAndi Kleen	def_bool y
11715bb38adcSAndi Kleen	depends on X86_MCE_INTEL
11724efc0670SAndi Kleen
117307dc900eSPeter Zijlstrasource "arch/x86/events/Kconfig"
1174e633c65aSKan Liang
11755aef51c3SAndy Lutomirskiconfig X86_LEGACY_VM86
11761e642812SIngo Molnar	bool "Legacy VM86 support"
1177506f1d07SSam Ravnborg	depends on X86_32
11788f9ca475SIngo Molnar	---help---
11795aef51c3SAndy Lutomirski	  This option allows user programs to put the CPU into V8086
11805aef51c3SAndy Lutomirski	  mode, which is an 80286-era approximation of 16-bit real mode.
11815aef51c3SAndy Lutomirski
11825aef51c3SAndy Lutomirski	  Some very old versions of X and/or vbetool require this option
11835aef51c3SAndy Lutomirski	  for user mode setting.  Similarly, DOSEMU will use it if
11845aef51c3SAndy Lutomirski	  available to accelerate real mode DOS programs.  However, any
11855aef51c3SAndy Lutomirski	  recent version of DOSEMU, X, or vbetool should be fully
11865aef51c3SAndy Lutomirski	  functional even without kernel VM86 support, as they will all
11871e642812SIngo Molnar	  fall back to software emulation. Nevertheless, if you are using
11881e642812SIngo Molnar	  a 16-bit DOS program where 16-bit performance matters, vm86
11891e642812SIngo Molnar	  mode might be faster than emulation and you might want to
11901e642812SIngo Molnar	  enable this option.
11915aef51c3SAndy Lutomirski
11921e642812SIngo Molnar	  Note that any app that works on a 64-bit kernel is unlikely to
11931e642812SIngo Molnar	  need this option, as 64-bit kernels don't, and can't, support
11941e642812SIngo Molnar	  V8086 mode. This option is also unrelated to 16-bit protected
11951e642812SIngo Molnar	  mode and is not needed to run most 16-bit programs under Wine.
11965aef51c3SAndy Lutomirski
11971e642812SIngo Molnar	  Enabling this option increases the complexity of the kernel
11981e642812SIngo Molnar	  and slows down exception handling a tiny bit.
11995aef51c3SAndy Lutomirski
12001e642812SIngo Molnar	  If unsure, say N here.
12015aef51c3SAndy Lutomirski
12025aef51c3SAndy Lutomirskiconfig VM86
12035aef51c3SAndy Lutomirski       bool
12045aef51c3SAndy Lutomirski       default X86_LEGACY_VM86
120534273f41SH. Peter Anvin
120634273f41SH. Peter Anvinconfig X86_16BIT
120734273f41SH. Peter Anvin	bool "Enable support for 16-bit segments" if EXPERT
120834273f41SH. Peter Anvin	default y
1209a5b9e5a2SAndy Lutomirski	depends on MODIFY_LDT_SYSCALL
121034273f41SH. Peter Anvin	---help---
121134273f41SH. Peter Anvin	  This option is required by programs like Wine to run 16-bit
121234273f41SH. Peter Anvin	  protected mode legacy code on x86 processors.  Disabling
121334273f41SH. Peter Anvin	  this option saves about 300 bytes on i386, or around 6K text
121434273f41SH. Peter Anvin	  plus 16K runtime memory on x86-64,
121534273f41SH. Peter Anvin
121634273f41SH. Peter Anvinconfig X86_ESPFIX32
121734273f41SH. Peter Anvin	def_bool y
121834273f41SH. Peter Anvin	depends on X86_16BIT && X86_32
1219506f1d07SSam Ravnborg
1220197725deSH. Peter Anvinconfig X86_ESPFIX64
1221197725deSH. Peter Anvin	def_bool y
122234273f41SH. Peter Anvin	depends on X86_16BIT && X86_64
1223506f1d07SSam Ravnborg
12241ad83c85SAndy Lutomirskiconfig X86_VSYSCALL_EMULATION
12251ad83c85SAndy Lutomirski       bool "Enable vsyscall emulation" if EXPERT
12261ad83c85SAndy Lutomirski       default y
12271ad83c85SAndy Lutomirski       depends on X86_64
12281ad83c85SAndy Lutomirski       ---help---
12291ad83c85SAndy Lutomirski	 This enables emulation of the legacy vsyscall page.  Disabling
12301ad83c85SAndy Lutomirski	 it is roughly equivalent to booting with vsyscall=none, except
12311ad83c85SAndy Lutomirski	 that it will also disable the helpful warning if a program
12321ad83c85SAndy Lutomirski	 tries to use a vsyscall.  With this option set to N, offending
12331ad83c85SAndy Lutomirski	 programs will just segfault, citing addresses of the form
12341ad83c85SAndy Lutomirski	 0xffffffffff600?00.
12351ad83c85SAndy Lutomirski
12361ad83c85SAndy Lutomirski	 This option is required by many programs built before 2013, and
12371ad83c85SAndy Lutomirski	 care should be used even with newer programs if set to N.
12381ad83c85SAndy Lutomirski
12391ad83c85SAndy Lutomirski	 Disabling this option saves about 7K of kernel size and
12401ad83c85SAndy Lutomirski	 possibly 4K of additional runtime pagetable memory.
12411ad83c85SAndy Lutomirski
1242506f1d07SSam Ravnborgconfig TOSHIBA
1243506f1d07SSam Ravnborg	tristate "Toshiba Laptop support"
1244506f1d07SSam Ravnborg	depends on X86_32
1245506f1d07SSam Ravnborg	---help---
1246506f1d07SSam Ravnborg	  This adds a driver to safely access the System Management Mode of
1247506f1d07SSam Ravnborg	  the CPU on Toshiba portables with a genuine Toshiba BIOS. It does
1248506f1d07SSam Ravnborg	  not work on models with a Phoenix BIOS. The System Management Mode
1249506f1d07SSam Ravnborg	  is used to set the BIOS and power saving options on Toshiba portables.
1250506f1d07SSam Ravnborg
1251506f1d07SSam Ravnborg	  For information on utilities to make use of this driver see the
1252506f1d07SSam Ravnborg	  Toshiba Linux utilities web site at:
1253506f1d07SSam Ravnborg	  <http://www.buzzard.org.uk/toshiba/>.
1254506f1d07SSam Ravnborg
1255506f1d07SSam Ravnborg	  Say Y if you intend to run this kernel on a Toshiba portable.
1256506f1d07SSam Ravnborg	  Say N otherwise.
1257506f1d07SSam Ravnborg
1258506f1d07SSam Ravnborgconfig I8K
1259039ae585SPali Rohár	tristate "Dell i8k legacy laptop support"
1260949a9d70SJean Delvare	select HWMON
1261039ae585SPali Rohár	select SENSORS_DELL_SMM
1262506f1d07SSam Ravnborg	---help---
1263039ae585SPali Rohár	  This option enables legacy /proc/i8k userspace interface in hwmon
1264039ae585SPali Rohár	  dell-smm-hwmon driver. Character file /proc/i8k reports bios version,
1265039ae585SPali Rohár	  temperature and allows controlling fan speeds of Dell laptops via
1266039ae585SPali Rohár	  System Management Mode. For old Dell laptops (like Dell Inspiron 8000)
1267039ae585SPali Rohár	  it reports also power and hotkey status. For fan speed control is
1268039ae585SPali Rohár	  needed userspace package i8kutils.
1269506f1d07SSam Ravnborg
1270039ae585SPali Rohár	  Say Y if you intend to run this kernel on old Dell laptops or want to
1271039ae585SPali Rohár	  use userspace package i8kutils.
1272506f1d07SSam Ravnborg	  Say N otherwise.
1273506f1d07SSam Ravnborg
1274506f1d07SSam Ravnborgconfig X86_REBOOTFIXUPS
12759ba16087SJan Beulich	bool "Enable X86 board specific fixups for reboot"
12769ba16087SJan Beulich	depends on X86_32
1277506f1d07SSam Ravnborg	---help---
1278506f1d07SSam Ravnborg	  This enables chipset and/or board specific fixups to be done
1279506f1d07SSam Ravnborg	  in order to get reboot to work correctly. This is only needed on
1280506f1d07SSam Ravnborg	  some combinations of hardware and BIOS. The symptom, for which
1281506f1d07SSam Ravnborg	  this config is intended, is when reboot ends with a stalled/hung
1282506f1d07SSam Ravnborg	  system.
1283506f1d07SSam Ravnborg
1284506f1d07SSam Ravnborg	  Currently, the only fixup is for the Geode machines using
12855e3a77e9SFlorian Fainelli	  CS5530A and CS5536 chipsets and the RDC R-321x SoC.
1286506f1d07SSam Ravnborg
1287506f1d07SSam Ravnborg	  Say Y if you want to enable the fixup. Currently, it's safe to
1288506f1d07SSam Ravnborg	  enable this option even if you don't need it.
1289506f1d07SSam Ravnborg	  Say N otherwise.
1290506f1d07SSam Ravnborg
1291506f1d07SSam Ravnborgconfig MICROCODE
12929a2bc335SBorislav Petkov	bool "CPU microcode loading support"
12939a2bc335SBorislav Petkov	default y
129480030e3dSBorislav Petkov	depends on CPU_SUP_AMD || CPU_SUP_INTEL
1295506f1d07SSam Ravnborg	select FW_LOADER
1296506f1d07SSam Ravnborg	---help---
1297506f1d07SSam Ravnborg	  If you say Y here, you will be able to update the microcode on
12985f9c01aaSBorislav Petkov	  Intel and AMD processors. The Intel support is for the IA32 family,
12995f9c01aaSBorislav Petkov	  e.g. Pentium Pro, Pentium II, Pentium III, Pentium 4, Xeon etc. The
13005f9c01aaSBorislav Petkov	  AMD support is for families 0x10 and later. You will obviously need
13015f9c01aaSBorislav Petkov	  the actual microcode binary data itself which is not shipped with
13025f9c01aaSBorislav Petkov	  the Linux kernel.
1303506f1d07SSam Ravnborg
13045f9c01aaSBorislav Petkov	  The preferred method to load microcode from a detached initrd is described
13051897a969SJaak Ristioja	  in Documentation/x86/microcode.txt. For that you need to enable
13065f9c01aaSBorislav Petkov	  CONFIG_BLK_DEV_INITRD in order for the loader to be able to scan the
13075f9c01aaSBorislav Petkov	  initrd for microcode blobs.
1308506f1d07SSam Ravnborg
1309c508c46eSBenjamin Gilbert	  In addition, you can build the microcode into the kernel. For that you
1310c508c46eSBenjamin Gilbert	  need to add the vendor-supplied microcode to the CONFIG_EXTRA_FIRMWARE
1311c508c46eSBenjamin Gilbert	  config option.
1312506f1d07SSam Ravnborg
13138d86f390SPeter Orubaconfig MICROCODE_INTEL
1314e43f6e67SBorislav Petkov	bool "Intel microcode loading support"
13158d86f390SPeter Oruba	depends on MICROCODE
13168d86f390SPeter Oruba	default MICROCODE
13178d86f390SPeter Oruba	select FW_LOADER
13188f9ca475SIngo Molnar	---help---
13198d86f390SPeter Oruba	  This options enables microcode patch loading support for Intel
13208d86f390SPeter Oruba	  processors.
13218d86f390SPeter Oruba
1322b8989db9SAlan	  For the current Intel microcode data package go to
1323b8989db9SAlan	  <https://downloadcenter.intel.com> and search for
1324b8989db9SAlan	  'Linux Processor Microcode Data File'.
13258d86f390SPeter Oruba
132680cc9f10SPeter Orubaconfig MICROCODE_AMD
1327e43f6e67SBorislav Petkov	bool "AMD microcode loading support"
132880cc9f10SPeter Oruba	depends on MICROCODE
132980cc9f10SPeter Oruba	select FW_LOADER
13308f9ca475SIngo Molnar	---help---
133180cc9f10SPeter Oruba	  If you select this option, microcode patch loading support for AMD
133280cc9f10SPeter Oruba	  processors will be enabled.
133380cc9f10SPeter Oruba
1334506f1d07SSam Ravnborgconfig MICROCODE_OLD_INTERFACE
13353c2362e6SHarvey Harrison	def_bool y
1336506f1d07SSam Ravnborg	depends on MICROCODE
1337506f1d07SSam Ravnborg
1338506f1d07SSam Ravnborgconfig X86_MSR
1339506f1d07SSam Ravnborg	tristate "/dev/cpu/*/msr - Model-specific register support"
13408f9ca475SIngo Molnar	---help---
1341506f1d07SSam Ravnborg	  This device gives privileged processes access to the x86
1342506f1d07SSam Ravnborg	  Model-Specific Registers (MSRs).  It is a character device with
1343506f1d07SSam Ravnborg	  major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr.
1344506f1d07SSam Ravnborg	  MSR accesses are directed to a specific CPU on multi-processor
1345506f1d07SSam Ravnborg	  systems.
1346506f1d07SSam Ravnborg
1347506f1d07SSam Ravnborgconfig X86_CPUID
1348506f1d07SSam Ravnborg	tristate "/dev/cpu/*/cpuid - CPU information support"
13498f9ca475SIngo Molnar	---help---
1350506f1d07SSam Ravnborg	  This device gives processes access to the x86 CPUID instruction to
1351506f1d07SSam Ravnborg	  be executed on a specific processor.  It is a character device
1352506f1d07SSam Ravnborg	  with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to
1353506f1d07SSam Ravnborg	  /dev/cpu/31/cpuid.
1354506f1d07SSam Ravnborg
1355506f1d07SSam Ravnborgchoice
1356506f1d07SSam Ravnborg	prompt "High Memory Support"
13576fc108a0SJan Beulich	default HIGHMEM4G
1358506f1d07SSam Ravnborg	depends on X86_32
1359506f1d07SSam Ravnborg
1360506f1d07SSam Ravnborgconfig NOHIGHMEM
1361506f1d07SSam Ravnborg	bool "off"
1362506f1d07SSam Ravnborg	---help---
1363506f1d07SSam Ravnborg	  Linux can use up to 64 Gigabytes of physical memory on x86 systems.
1364506f1d07SSam Ravnborg	  However, the address space of 32-bit x86 processors is only 4
1365506f1d07SSam Ravnborg	  Gigabytes large. That means that, if you have a large amount of
1366506f1d07SSam Ravnborg	  physical memory, not all of it can be "permanently mapped" by the
1367506f1d07SSam Ravnborg	  kernel. The physical memory that's not permanently mapped is called
1368506f1d07SSam Ravnborg	  "high memory".
1369506f1d07SSam Ravnborg
1370506f1d07SSam Ravnborg	  If you are compiling a kernel which will never run on a machine with
1371506f1d07SSam Ravnborg	  more than 1 Gigabyte total physical RAM, answer "off" here (default
1372506f1d07SSam Ravnborg	  choice and suitable for most users). This will result in a "3GB/1GB"
1373506f1d07SSam Ravnborg	  split: 3GB are mapped so that each process sees a 3GB virtual memory
1374506f1d07SSam Ravnborg	  space and the remaining part of the 4GB virtual memory space is used
1375506f1d07SSam Ravnborg	  by the kernel to permanently map as much physical memory as
1376506f1d07SSam Ravnborg	  possible.
1377506f1d07SSam Ravnborg
1378506f1d07SSam Ravnborg	  If the machine has between 1 and 4 Gigabytes physical RAM, then
1379506f1d07SSam Ravnborg	  answer "4GB" here.
1380506f1d07SSam Ravnborg
1381506f1d07SSam Ravnborg	  If more than 4 Gigabytes is used then answer "64GB" here. This
1382506f1d07SSam Ravnborg	  selection turns Intel PAE (Physical Address Extension) mode on.
1383506f1d07SSam Ravnborg	  PAE implements 3-level paging on IA32 processors. PAE is fully
1384506f1d07SSam Ravnborg	  supported by Linux, PAE mode is implemented on all recent Intel
1385506f1d07SSam Ravnborg	  processors (Pentium Pro and better). NOTE: If you say "64GB" here,
1386506f1d07SSam Ravnborg	  then the kernel will not boot on CPUs that don't support PAE!
1387506f1d07SSam Ravnborg
1388506f1d07SSam Ravnborg	  The actual amount of total physical memory will either be
1389506f1d07SSam Ravnborg	  auto detected or can be forced by using a kernel command line option
1390506f1d07SSam Ravnborg	  such as "mem=256M". (Try "man bootparam" or see the documentation of
1391506f1d07SSam Ravnborg	  your boot loader (lilo or loadlin) about how to pass options to the
1392506f1d07SSam Ravnborg	  kernel at boot time.)
1393506f1d07SSam Ravnborg
1394506f1d07SSam Ravnborg	  If unsure, say "off".
1395506f1d07SSam Ravnborg
1396506f1d07SSam Ravnborgconfig HIGHMEM4G
1397506f1d07SSam Ravnborg	bool "4GB"
13988f9ca475SIngo Molnar	---help---
1399506f1d07SSam Ravnborg	  Select this if you have a 32-bit processor and between 1 and 4
1400506f1d07SSam Ravnborg	  gigabytes of physical RAM.
1401506f1d07SSam Ravnborg
1402506f1d07SSam Ravnborgconfig HIGHMEM64G
1403506f1d07SSam Ravnborg	bool "64GB"
140469b8d3fcSMatthew Whitehead	depends on !M486 && !M586 && !M586TSC && !M586MMX && !MGEODE_LX && !MGEODEGX1 && !MCYRIXIII && !MELAN && !MWINCHIPC6 && !WINCHIP3D && !MK6
1405506f1d07SSam Ravnborg	select X86_PAE
14068f9ca475SIngo Molnar	---help---
1407506f1d07SSam Ravnborg	  Select this if you have a 32-bit processor and more than 4
1408506f1d07SSam Ravnborg	  gigabytes of physical RAM.
1409506f1d07SSam Ravnborg
1410506f1d07SSam Ravnborgendchoice
1411506f1d07SSam Ravnborg
1412506f1d07SSam Ravnborgchoice
14136a108a14SDavid Rientjes	prompt "Memory split" if EXPERT
1414506f1d07SSam Ravnborg	default VMSPLIT_3G
1415506f1d07SSam Ravnborg	depends on X86_32
14168f9ca475SIngo Molnar	---help---
1417506f1d07SSam Ravnborg	  Select the desired split between kernel and user memory.
1418506f1d07SSam Ravnborg
1419506f1d07SSam Ravnborg	  If the address range available to the kernel is less than the
1420506f1d07SSam Ravnborg	  physical memory installed, the remaining memory will be available
1421506f1d07SSam Ravnborg	  as "high memory". Accessing high memory is a little more costly
1422506f1d07SSam Ravnborg	  than low memory, as it needs to be mapped into the kernel first.
1423506f1d07SSam Ravnborg	  Note that increasing the kernel address space limits the range
1424506f1d07SSam Ravnborg	  available to user programs, making the address space there
1425506f1d07SSam Ravnborg	  tighter.  Selecting anything other than the default 3G/1G split
1426506f1d07SSam Ravnborg	  will also likely make your kernel incompatible with binary-only
1427506f1d07SSam Ravnborg	  kernel modules.
1428506f1d07SSam Ravnborg
1429506f1d07SSam Ravnborg	  If you are not absolutely sure what you are doing, leave this
1430506f1d07SSam Ravnborg	  option alone!
1431506f1d07SSam Ravnborg
1432506f1d07SSam Ravnborg	config VMSPLIT_3G
1433506f1d07SSam Ravnborg		bool "3G/1G user/kernel split"
1434506f1d07SSam Ravnborg	config VMSPLIT_3G_OPT
1435506f1d07SSam Ravnborg		depends on !X86_PAE
1436506f1d07SSam Ravnborg		bool "3G/1G user/kernel split (for full 1G low memory)"
1437506f1d07SSam Ravnborg	config VMSPLIT_2G
1438506f1d07SSam Ravnborg		bool "2G/2G user/kernel split"
1439506f1d07SSam Ravnborg	config VMSPLIT_2G_OPT
1440506f1d07SSam Ravnborg		depends on !X86_PAE
1441506f1d07SSam Ravnborg		bool "2G/2G user/kernel split (for full 2G low memory)"
1442506f1d07SSam Ravnborg	config VMSPLIT_1G
1443506f1d07SSam Ravnborg		bool "1G/3G user/kernel split"
1444506f1d07SSam Ravnborgendchoice
1445506f1d07SSam Ravnborg
1446506f1d07SSam Ravnborgconfig PAGE_OFFSET
1447506f1d07SSam Ravnborg	hex
1448506f1d07SSam Ravnborg	default 0xB0000000 if VMSPLIT_3G_OPT
1449506f1d07SSam Ravnborg	default 0x80000000 if VMSPLIT_2G
1450506f1d07SSam Ravnborg	default 0x78000000 if VMSPLIT_2G_OPT
1451506f1d07SSam Ravnborg	default 0x40000000 if VMSPLIT_1G
1452506f1d07SSam Ravnborg	default 0xC0000000
1453506f1d07SSam Ravnborg	depends on X86_32
1454506f1d07SSam Ravnborg
1455506f1d07SSam Ravnborgconfig HIGHMEM
14563c2362e6SHarvey Harrison	def_bool y
1457506f1d07SSam Ravnborg	depends on X86_32 && (HIGHMEM64G || HIGHMEM4G)
1458506f1d07SSam Ravnborg
1459506f1d07SSam Ravnborgconfig X86_PAE
14609ba16087SJan Beulich	bool "PAE (Physical Address Extension) Support"
1461506f1d07SSam Ravnborg	depends on X86_32 && !HIGHMEM4G
1462d4a451d5SChristoph Hellwig	select PHYS_ADDR_T_64BIT
14639d99c712SChristian Melki	select SWIOTLB
14648f9ca475SIngo Molnar	---help---
1465506f1d07SSam Ravnborg	  PAE is required for NX support, and furthermore enables
1466506f1d07SSam Ravnborg	  larger swapspace support for non-overcommit purposes. It
1467506f1d07SSam Ravnborg	  has the cost of more pagetable lookup overhead, and also
1468506f1d07SSam Ravnborg	  consumes more pagetable space per process.
1469506f1d07SSam Ravnborg
147077ef56e4SKirill A. Shutemovconfig X86_5LEVEL
147177ef56e4SKirill A. Shutemov	bool "Enable 5-level page tables support"
1472eedb92abSKirill A. Shutemov	select DYNAMIC_MEMORY_LAYOUT
1473162434e7SKirill A. Shutemov	select SPARSEMEM_VMEMMAP
147477ef56e4SKirill A. Shutemov	depends on X86_64
147577ef56e4SKirill A. Shutemov	---help---
147677ef56e4SKirill A. Shutemov	  5-level paging enables access to larger address space:
147777ef56e4SKirill A. Shutemov	  upto 128 PiB of virtual address space and 4 PiB of
147877ef56e4SKirill A. Shutemov	  physical address space.
147977ef56e4SKirill A. Shutemov
148077ef56e4SKirill A. Shutemov	  It will be supported by future Intel CPUs.
148177ef56e4SKirill A. Shutemov
14826657fca0SKirill A. Shutemov	  A kernel with the option enabled can be booted on machines that
14836657fca0SKirill A. Shutemov	  support 4- or 5-level paging.
148477ef56e4SKirill A. Shutemov
148577ef56e4SKirill A. Shutemov	  See Documentation/x86/x86_64/5level-paging.txt for more
148677ef56e4SKirill A. Shutemov	  information.
148777ef56e4SKirill A. Shutemov
148877ef56e4SKirill A. Shutemov	  Say N if unsure.
148977ef56e4SKirill A. Shutemov
149010971ab2SIngo Molnarconfig X86_DIRECT_GBPAGES
1491e5008abeSLuis R. Rodriguez	def_bool y
14924675ff05SLevin, Alexander (Sasha Levin)	depends on X86_64 && !DEBUG_PAGEALLOC
14938f9ca475SIngo Molnar	---help---
149410971ab2SIngo Molnar	  Certain kernel features effectively disable kernel
149510971ab2SIngo Molnar	  linear 1 GB mappings (even if the CPU otherwise
149610971ab2SIngo Molnar	  supports them), so don't confuse the user by printing
149710971ab2SIngo Molnar	  that we have them enabled.
14989e899816SNick Piggin
14995c280cf6SThomas Gleixnerconfig X86_CPA_STATISTICS
15005c280cf6SThomas Gleixner	bool "Enable statistic for Change Page Attribute"
15015c280cf6SThomas Gleixner	depends on DEBUG_FS
15025c280cf6SThomas Gleixner	---help---
15035c280cf6SThomas Gleixner	  Expose statistics about the Change Page Attribute mechanims, which
15045c280cf6SThomas Gleixner	  helps to determine the effectivness of preserving large and huge
15055c280cf6SThomas Gleixner	  page mappings when mapping protections are changed.
15065c280cf6SThomas Gleixner
15077744ccdbSTom Lendackyconfig ARCH_HAS_MEM_ENCRYPT
15087744ccdbSTom Lendacky	def_bool y
15097744ccdbSTom Lendacky
15107744ccdbSTom Lendackyconfig AMD_MEM_ENCRYPT
15117744ccdbSTom Lendacky	bool "AMD Secure Memory Encryption (SME) support"
15127744ccdbSTom Lendacky	depends on X86_64 && CPU_SUP_AMD
151394d49eb3SKirill A. Shutemov	select DYNAMIC_PHYSICAL_MASK
15147744ccdbSTom Lendacky	---help---
15157744ccdbSTom Lendacky	  Say yes to enable support for the encryption of system memory.
15167744ccdbSTom Lendacky	  This requires an AMD processor that supports Secure Memory
15177744ccdbSTom Lendacky	  Encryption (SME).
15187744ccdbSTom Lendacky
15197744ccdbSTom Lendackyconfig AMD_MEM_ENCRYPT_ACTIVE_BY_DEFAULT
15207744ccdbSTom Lendacky	bool "Activate AMD Secure Memory Encryption (SME) by default"
15217744ccdbSTom Lendacky	default y
15227744ccdbSTom Lendacky	depends on AMD_MEM_ENCRYPT
15237744ccdbSTom Lendacky	---help---
15247744ccdbSTom Lendacky	  Say yes to have system memory encrypted by default if running on
15257744ccdbSTom Lendacky	  an AMD processor that supports Secure Memory Encryption (SME).
15267744ccdbSTom Lendacky
15277744ccdbSTom Lendacky	  If set to Y, then the encryption of system memory can be
15287744ccdbSTom Lendacky	  deactivated with the mem_encrypt=off command line option.
15297744ccdbSTom Lendacky
15307744ccdbSTom Lendacky	  If set to N, then the encryption of system memory can be
15317744ccdbSTom Lendacky	  activated with the mem_encrypt=on command line option.
15327744ccdbSTom Lendacky
1533f88a68faSTom Lendackyconfig ARCH_USE_MEMREMAP_PROT
1534f88a68faSTom Lendacky	def_bool y
1535f88a68faSTom Lendacky	depends on AMD_MEM_ENCRYPT
1536f88a68faSTom Lendacky
1537506f1d07SSam Ravnborg# Common NUMA Features
1538506f1d07SSam Ravnborgconfig NUMA
1539fd51b2d7SKOSAKI Motohiro	bool "Numa Memory Allocation and Scheduler Support"
1540506f1d07SSam Ravnborg	depends on SMP
1541b5660ba7SH. Peter Anvin	depends on X86_64 || (X86_32 && HIGHMEM64G && X86_BIGSMP)
1542b5660ba7SH. Peter Anvin	default y if X86_BIGSMP
15438f9ca475SIngo Molnar	---help---
1544506f1d07SSam Ravnborg	  Enable NUMA (Non Uniform Memory Access) support.
1545fd51b2d7SKOSAKI Motohiro
1546506f1d07SSam Ravnborg	  The kernel will try to allocate memory used by a CPU on the
1547506f1d07SSam Ravnborg	  local memory controller of the CPU and add some more
1548506f1d07SSam Ravnborg	  NUMA awareness to the kernel.
1549506f1d07SSam Ravnborg
1550c280ea5eSIngo Molnar	  For 64-bit this is recommended if the system is Intel Core i7
1551fd51b2d7SKOSAKI Motohiro	  (or later), AMD Opteron, or EM64T NUMA.
1552fd51b2d7SKOSAKI Motohiro
1553b5660ba7SH. Peter Anvin	  For 32-bit this is only needed if you boot a 32-bit
15547cf6c945SDavid Rientjes	  kernel on a 64-bit NUMA platform.
1555fd51b2d7SKOSAKI Motohiro
1556fd51b2d7SKOSAKI Motohiro	  Otherwise, you should say N.
1557506f1d07SSam Ravnborg
1558eec1d4faSHans Rosenfeldconfig AMD_NUMA
15593c2362e6SHarvey Harrison	def_bool y
15603c2362e6SHarvey Harrison	prompt "Old style AMD Opteron NUMA detection"
15615da0ef9aSTejun Heo	depends on X86_64 && NUMA && PCI
15628f9ca475SIngo Molnar	---help---
1563eec1d4faSHans Rosenfeld	  Enable AMD NUMA node topology detection.  You should say Y here if
1564eec1d4faSHans Rosenfeld	  you have a multi processor AMD system. This uses an old method to
1565eec1d4faSHans Rosenfeld	  read the NUMA configuration directly from the builtin Northbridge
1566eec1d4faSHans Rosenfeld	  of Opteron. It is recommended to use X86_64_ACPI_NUMA instead,
1567eec1d4faSHans Rosenfeld	  which also takes priority if both are compiled in.
1568506f1d07SSam Ravnborg
1569506f1d07SSam Ravnborgconfig X86_64_ACPI_NUMA
15703c2362e6SHarvey Harrison	def_bool y
15713c2362e6SHarvey Harrison	prompt "ACPI NUMA detection"
1572506f1d07SSam Ravnborg	depends on X86_64 && NUMA && ACPI && PCI
1573506f1d07SSam Ravnborg	select ACPI_NUMA
15748f9ca475SIngo Molnar	---help---
1575506f1d07SSam Ravnborg	  Enable ACPI SRAT based node topology detection.
1576506f1d07SSam Ravnborg
15776ec6e0d9SSuresh Siddha# Some NUMA nodes have memory ranges that span
15786ec6e0d9SSuresh Siddha# other nodes.  Even though a pfn is valid and
15796ec6e0d9SSuresh Siddha# between a node's start and end pfns, it may not
15806ec6e0d9SSuresh Siddha# reside on that node.  See memmap_init_zone()
15816ec6e0d9SSuresh Siddha# for details.
15826ec6e0d9SSuresh Siddhaconfig NODES_SPAN_OTHER_NODES
15836ec6e0d9SSuresh Siddha	def_bool y
15846ec6e0d9SSuresh Siddha	depends on X86_64_ACPI_NUMA
15856ec6e0d9SSuresh Siddha
1586506f1d07SSam Ravnborgconfig NUMA_EMU
1587506f1d07SSam Ravnborg	bool "NUMA emulation"
15881b7e03efSTejun Heo	depends on NUMA
15898f9ca475SIngo Molnar	---help---
1590506f1d07SSam Ravnborg	  Enable NUMA emulation. A flat machine will be split
1591506f1d07SSam Ravnborg	  into virtual nodes when booted with "numa=fake=N", where N is the
1592506f1d07SSam Ravnborg	  number of nodes. This is only useful for debugging.
1593506f1d07SSam Ravnborg
1594506f1d07SSam Ravnborgconfig NODES_SHIFT
1595d25e26b6SLinus Torvalds	int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP
159651591e31SDavid Rientjes	range 1 10
159751591e31SDavid Rientjes	default "10" if MAXSMP
1598506f1d07SSam Ravnborg	default "6" if X86_64
1599506f1d07SSam Ravnborg	default "3"
1600506f1d07SSam Ravnborg	depends on NEED_MULTIPLE_NODES
16018f9ca475SIngo Molnar	---help---
16021184dc2fSMike Travis	  Specify the maximum number of NUMA Nodes available on the target
1603692105b8SMatt LaPlante	  system.  Increases memory reserved to accommodate various tables.
1604506f1d07SSam Ravnborg
1605506f1d07SSam Ravnborgconfig ARCH_HAVE_MEMORY_PRESENT
16063c2362e6SHarvey Harrison	def_bool y
1607506f1d07SSam Ravnborg	depends on X86_32 && DISCONTIGMEM
1608506f1d07SSam Ravnborg
1609506f1d07SSam Ravnborgconfig ARCH_FLATMEM_ENABLE
1610506f1d07SSam Ravnborg	def_bool y
16113b16651fSTejun Heo	depends on X86_32 && !NUMA
1612506f1d07SSam Ravnborg
1613506f1d07SSam Ravnborgconfig ARCH_DISCONTIGMEM_ENABLE
1614506f1d07SSam Ravnborg	def_bool y
1615b263295dSChristoph Lameter	depends on NUMA && X86_32
1616506f1d07SSam Ravnborg
1617506f1d07SSam Ravnborgconfig ARCH_DISCONTIGMEM_DEFAULT
1618506f1d07SSam Ravnborg	def_bool y
1619b263295dSChristoph Lameter	depends on NUMA && X86_32
1620b263295dSChristoph Lameter
1621506f1d07SSam Ravnborgconfig ARCH_SPARSEMEM_ENABLE
1622506f1d07SSam Ravnborg	def_bool y
16236ea30386SKees Cook	depends on X86_64 || NUMA || X86_32 || X86_32_NON_STANDARD
1624506f1d07SSam Ravnborg	select SPARSEMEM_STATIC if X86_32
1625506f1d07SSam Ravnborg	select SPARSEMEM_VMEMMAP_ENABLE if X86_64
1626506f1d07SSam Ravnborg
16273b16651fSTejun Heoconfig ARCH_SPARSEMEM_DEFAULT
16283b16651fSTejun Heo	def_bool y
16293b16651fSTejun Heo	depends on X86_64
16303b16651fSTejun Heo
1631506f1d07SSam Ravnborgconfig ARCH_SELECT_MEMORY_MODEL
1632506f1d07SSam Ravnborg	def_bool y
1633b263295dSChristoph Lameter	depends on ARCH_SPARSEMEM_ENABLE
1634506f1d07SSam Ravnborg
1635506f1d07SSam Ravnborgconfig ARCH_MEMORY_PROBE
1636a0842b70SToshi Kani	bool "Enable sysfs memory/probe interface"
16373120e25eSJan Beulich	depends on X86_64 && MEMORY_HOTPLUG
1638a0842b70SToshi Kani	help
1639a0842b70SToshi Kani	  This option enables a sysfs memory/probe interface for testing.
1640a0842b70SToshi Kani	  See Documentation/memory-hotplug.txt for more information.
1641a0842b70SToshi Kani	  If you are unsure how to answer this question, answer N.
1642506f1d07SSam Ravnborg
16433b16651fSTejun Heoconfig ARCH_PROC_KCORE_TEXT
16443b16651fSTejun Heo	def_bool y
16453b16651fSTejun Heo	depends on X86_64 && PROC_KCORE
16463b16651fSTejun Heo
1647a29815a3SAvi Kivityconfig ILLEGAL_POINTER_VALUE
1648a29815a3SAvi Kivity       hex
1649a29815a3SAvi Kivity       default 0 if X86_32
1650a29815a3SAvi Kivity       default 0xdead000000000000 if X86_64
1651a29815a3SAvi Kivity
16527a67832cSDan Williamsconfig X86_PMEM_LEGACY_DEVICE
16537a67832cSDan Williams	bool
16547a67832cSDan Williams
1655ec776ef6SChristoph Hellwigconfig X86_PMEM_LEGACY
16567a67832cSDan Williams	tristate "Support non-standard NVDIMMs and ADR protected memory"
16579f53f9faSDan Williams	depends on PHYS_ADDR_T_64BIT
16589f53f9faSDan Williams	depends on BLK_DEV
16597a67832cSDan Williams	select X86_PMEM_LEGACY_DEVICE
16609f53f9faSDan Williams	select LIBNVDIMM
1661ec776ef6SChristoph Hellwig	help
1662ec776ef6SChristoph Hellwig	  Treat memory marked using the non-standard e820 type of 12 as used
1663ec776ef6SChristoph Hellwig	  by the Intel Sandy Bridge-EP reference BIOS as protected memory.
1664ec776ef6SChristoph Hellwig	  The kernel will offer these regions to the 'pmem' driver so
1665ec776ef6SChristoph Hellwig	  they can be used for persistent storage.
1666ec776ef6SChristoph Hellwig
1667ec776ef6SChristoph Hellwig	  Say Y if unsure.
1668ec776ef6SChristoph Hellwig
1669506f1d07SSam Ravnborgconfig HIGHPTE
1670506f1d07SSam Ravnborg	bool "Allocate 3rd-level pagetables from highmem"
16716fc108a0SJan Beulich	depends on HIGHMEM
16728f9ca475SIngo Molnar	---help---
1673506f1d07SSam Ravnborg	  The VM uses one page table entry for each page of physical memory.
1674506f1d07SSam Ravnborg	  For systems with a lot of RAM, this can be wasteful of precious
1675506f1d07SSam Ravnborg	  low memory.  Setting this option will put user-space page table
1676506f1d07SSam Ravnborg	  entries in high memory.
1677506f1d07SSam Ravnborg
16789f077871SJeremy Fitzhardingeconfig X86_CHECK_BIOS_CORRUPTION
16799f077871SJeremy Fitzhardinge	bool "Check for low memory corruption"
16808f9ca475SIngo Molnar	---help---
16819f077871SJeremy Fitzhardinge	  Periodically check for memory corruption in low memory, which
16829f077871SJeremy Fitzhardinge	  is suspected to be caused by BIOS.  Even when enabled in the
16839f077871SJeremy Fitzhardinge	  configuration, it is disabled at runtime.  Enable it by
16849f077871SJeremy Fitzhardinge	  setting "memory_corruption_check=1" on the kernel command
16859f077871SJeremy Fitzhardinge	  line.  By default it scans the low 64k of memory every 60
16869f077871SJeremy Fitzhardinge	  seconds; see the memory_corruption_check_size and
16879f077871SJeremy Fitzhardinge	  memory_corruption_check_period parameters in
16888c27ceffSMauro Carvalho Chehab	  Documentation/admin-guide/kernel-parameters.rst to adjust this.
16899f077871SJeremy Fitzhardinge
16909f077871SJeremy Fitzhardinge	  When enabled with the default parameters, this option has
16919f077871SJeremy Fitzhardinge	  almost no overhead, as it reserves a relatively small amount
16929f077871SJeremy Fitzhardinge	  of memory and scans it infrequently.  It both detects corruption
16939f077871SJeremy Fitzhardinge	  and prevents it from affecting the running system.
16949f077871SJeremy Fitzhardinge
16959f077871SJeremy Fitzhardinge	  It is, however, intended as a diagnostic tool; if repeatable
16969f077871SJeremy Fitzhardinge	  BIOS-originated corruption always affects the same memory,
16979f077871SJeremy Fitzhardinge	  you can use memmap= to prevent the kernel from using that
16989f077871SJeremy Fitzhardinge	  memory.
16999f077871SJeremy Fitzhardinge
1700c885df50SJeremy Fitzhardingeconfig X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK
1701c885df50SJeremy Fitzhardinge	bool "Set the default setting of memory_corruption_check"
1702c885df50SJeremy Fitzhardinge	depends on X86_CHECK_BIOS_CORRUPTION
1703c885df50SJeremy Fitzhardinge	default y
17048f9ca475SIngo Molnar	---help---
1705c885df50SJeremy Fitzhardinge	  Set whether the default state of memory_corruption_check is
1706c885df50SJeremy Fitzhardinge	  on or off.
1707c885df50SJeremy Fitzhardinge
17089ea77bdbSH. Peter Anvinconfig X86_RESERVE_LOW
1709d0cd7425SH. Peter Anvin	int "Amount of low memory, in kilobytes, to reserve for the BIOS"
1710d0cd7425SH. Peter Anvin	default 64
1711d0cd7425SH. Peter Anvin	range 4 640
17128f9ca475SIngo Molnar	---help---
1713d0cd7425SH. Peter Anvin	  Specify the amount of low memory to reserve for the BIOS.
1714fc381519SIngo Molnar
1715d0cd7425SH. Peter Anvin	  The first page contains BIOS data structures that the kernel
1716d0cd7425SH. Peter Anvin	  must not use, so that page must always be reserved.
1717fc381519SIngo Molnar
1718d0cd7425SH. Peter Anvin	  By default we reserve the first 64K of physical RAM, as a
1719d0cd7425SH. Peter Anvin	  number of BIOSes are known to corrupt that memory range
1720d0cd7425SH. Peter Anvin	  during events such as suspend/resume or monitor cable
1721d0cd7425SH. Peter Anvin	  insertion, so it must not be used by the kernel.
1722fc381519SIngo Molnar
1723d0cd7425SH. Peter Anvin	  You can set this to 4 if you are absolutely sure that you
1724d0cd7425SH. Peter Anvin	  trust the BIOS to get all its memory reservations and usages
1725d0cd7425SH. Peter Anvin	  right.  If you know your BIOS have problems beyond the
1726d0cd7425SH. Peter Anvin	  default 64K area, you can set this to 640 to avoid using the
1727d0cd7425SH. Peter Anvin	  entire low memory range.
1728d0cd7425SH. Peter Anvin
1729d0cd7425SH. Peter Anvin	  If you have doubts about the BIOS (e.g. suspend/resume does
1730d0cd7425SH. Peter Anvin	  not work or there's kernel crashes after certain hardware
1731d0cd7425SH. Peter Anvin	  hotplug events) then you might want to enable
1732d0cd7425SH. Peter Anvin	  X86_CHECK_BIOS_CORRUPTION=y to allow the kernel to check
1733d0cd7425SH. Peter Anvin	  typical corruption patterns.
1734d0cd7425SH. Peter Anvin
1735d0cd7425SH. Peter Anvin	  Leave this to the default value of 64 if you are unsure.
1736fc381519SIngo Molnar
1737506f1d07SSam Ravnborgconfig MATH_EMULATION
1738506f1d07SSam Ravnborg	bool
1739a5b9e5a2SAndy Lutomirski	depends on MODIFY_LDT_SYSCALL
1740506f1d07SSam Ravnborg	prompt "Math emulation" if X86_32
1741506f1d07SSam Ravnborg	---help---
1742506f1d07SSam Ravnborg	  Linux can emulate a math coprocessor (used for floating point
1743506f1d07SSam Ravnborg	  operations) if you don't have one. 486DX and Pentium processors have
1744506f1d07SSam Ravnborg	  a math coprocessor built in, 486SX and 386 do not, unless you added
1745506f1d07SSam Ravnborg	  a 487DX or 387, respectively. (The messages during boot time can
1746506f1d07SSam Ravnborg	  give you some hints here ["man dmesg"].) Everyone needs either a
1747506f1d07SSam Ravnborg	  coprocessor or this emulation.
1748506f1d07SSam Ravnborg
1749506f1d07SSam Ravnborg	  If you don't have a math coprocessor, you need to say Y here; if you
1750506f1d07SSam Ravnborg	  say Y here even though you have a coprocessor, the coprocessor will
1751506f1d07SSam Ravnborg	  be used nevertheless. (This behavior can be changed with the kernel
1752506f1d07SSam Ravnborg	  command line option "no387", which comes handy if your coprocessor
1753506f1d07SSam Ravnborg	  is broken. Try "man bootparam" or see the documentation of your boot
1754506f1d07SSam Ravnborg	  loader (lilo or loadlin) about how to pass options to the kernel at
1755506f1d07SSam Ravnborg	  boot time.) This means that it is a good idea to say Y here if you
1756506f1d07SSam Ravnborg	  intend to use this kernel on different machines.
1757506f1d07SSam Ravnborg
1758506f1d07SSam Ravnborg	  More information about the internals of the Linux math coprocessor
1759506f1d07SSam Ravnborg	  emulation can be found in <file:arch/x86/math-emu/README>.
1760506f1d07SSam Ravnborg
1761506f1d07SSam Ravnborg	  If you are not sure, say Y; apart from resulting in a 66 KB bigger
1762506f1d07SSam Ravnborg	  kernel, it won't hurt.
1763506f1d07SSam Ravnborg
1764506f1d07SSam Ravnborgconfig MTRR
17656fc108a0SJan Beulich	def_bool y
17666a108a14SDavid Rientjes	prompt "MTRR (Memory Type Range Register) support" if EXPERT
1767506f1d07SSam Ravnborg	---help---
1768506f1d07SSam Ravnborg	  On Intel P6 family processors (Pentium Pro, Pentium II and later)
1769506f1d07SSam Ravnborg	  the Memory Type Range Registers (MTRRs) may be used to control
1770506f1d07SSam Ravnborg	  processor access to memory ranges. This is most useful if you have
1771506f1d07SSam Ravnborg	  a video (VGA) card on a PCI or AGP bus. Enabling write-combining
1772506f1d07SSam Ravnborg	  allows bus write transfers to be combined into a larger transfer
1773506f1d07SSam Ravnborg	  before bursting over the PCI/AGP bus. This can increase performance
1774506f1d07SSam Ravnborg	  of image write operations 2.5 times or more. Saying Y here creates a
1775506f1d07SSam Ravnborg	  /proc/mtrr file which may be used to manipulate your processor's
1776506f1d07SSam Ravnborg	  MTRRs. Typically the X server should use this.
1777506f1d07SSam Ravnborg
1778506f1d07SSam Ravnborg	  This code has a reasonably generic interface so that similar
1779506f1d07SSam Ravnborg	  control registers on other processors can be easily supported
1780506f1d07SSam Ravnborg	  as well:
1781506f1d07SSam Ravnborg
1782506f1d07SSam Ravnborg	  The Cyrix 6x86, 6x86MX and M II processors have Address Range
1783506f1d07SSam Ravnborg	  Registers (ARRs) which provide a similar functionality to MTRRs. For
1784506f1d07SSam Ravnborg	  these, the ARRs are used to emulate the MTRRs.
1785506f1d07SSam Ravnborg	  The AMD K6-2 (stepping 8 and above) and K6-3 processors have two
1786506f1d07SSam Ravnborg	  MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing
1787506f1d07SSam Ravnborg	  write-combining. All of these processors are supported by this code
1788506f1d07SSam Ravnborg	  and it makes sense to say Y here if you have one of them.
1789506f1d07SSam Ravnborg
1790506f1d07SSam Ravnborg	  Saying Y here also fixes a problem with buggy SMP BIOSes which only
1791506f1d07SSam Ravnborg	  set the MTRRs for the boot CPU and not for the secondary CPUs. This
1792506f1d07SSam Ravnborg	  can lead to all sorts of problems, so it's good to say Y here.
1793506f1d07SSam Ravnborg
1794506f1d07SSam Ravnborg	  You can safely say Y even if your machine doesn't have MTRRs, you'll
1795506f1d07SSam Ravnborg	  just add about 9 KB to your kernel.
1796506f1d07SSam Ravnborg
17977225e751SRandy Dunlap	  See <file:Documentation/x86/mtrr.txt> for more information.
1798506f1d07SSam Ravnborg
179995ffa243SYinghai Luconfig MTRR_SANITIZER
18002ffb3501SYinghai Lu	def_bool y
180195ffa243SYinghai Lu	prompt "MTRR cleanup support"
180295ffa243SYinghai Lu	depends on MTRR
18038f9ca475SIngo Molnar	---help---
1804aba3728cSThomas Gleixner	  Convert MTRR layout from continuous to discrete, so X drivers can
1805aba3728cSThomas Gleixner	  add writeback entries.
180695ffa243SYinghai Lu
1807aba3728cSThomas Gleixner	  Can be disabled with disable_mtrr_cleanup on the kernel command line.
1808692105b8SMatt LaPlante	  The largest mtrr entry size for a continuous block can be set with
1809aba3728cSThomas Gleixner	  mtrr_chunk_size.
181095ffa243SYinghai Lu
18112ffb3501SYinghai Lu	  If unsure, say Y.
181295ffa243SYinghai Lu
181395ffa243SYinghai Luconfig MTRR_SANITIZER_ENABLE_DEFAULT
1814f5098d62SYinghai Lu	int "MTRR cleanup enable value (0-1)"
1815f5098d62SYinghai Lu	range 0 1
1816f5098d62SYinghai Lu	default "0"
181795ffa243SYinghai Lu	depends on MTRR_SANITIZER
18188f9ca475SIngo Molnar	---help---
1819f5098d62SYinghai Lu	  Enable mtrr cleanup default value
182095ffa243SYinghai Lu
182112031a62SYinghai Luconfig MTRR_SANITIZER_SPARE_REG_NR_DEFAULT
182212031a62SYinghai Lu	int "MTRR cleanup spare reg num (0-7)"
182312031a62SYinghai Lu	range 0 7
182412031a62SYinghai Lu	default "1"
182512031a62SYinghai Lu	depends on MTRR_SANITIZER
18268f9ca475SIngo Molnar	---help---
182712031a62SYinghai Lu	  mtrr cleanup spare entries default, it can be changed via
1828aba3728cSThomas Gleixner	  mtrr_spare_reg_nr=N on the kernel command line.
182912031a62SYinghai Lu
18302e5d9c85Svenkatesh.pallipadi@intel.comconfig X86_PAT
18316fc108a0SJan Beulich	def_bool y
18326a108a14SDavid Rientjes	prompt "x86 PAT support" if EXPERT
18332a8a2719SIngo Molnar	depends on MTRR
18348f9ca475SIngo Molnar	---help---
18352e5d9c85Svenkatesh.pallipadi@intel.com	  Use PAT attributes to setup page level cache control.
1836042b78e4SVenki Pallipadi
18372e5d9c85Svenkatesh.pallipadi@intel.com	  PATs are the modern equivalents of MTRRs and are much more
18382e5d9c85Svenkatesh.pallipadi@intel.com	  flexible than MTRRs.
18392e5d9c85Svenkatesh.pallipadi@intel.com
18402e5d9c85Svenkatesh.pallipadi@intel.com	  Say N here if you see bootup problems (boot crash, boot hang,
1841042b78e4SVenki Pallipadi	  spontaneous reboots) or a non-working video driver.
18422e5d9c85Svenkatesh.pallipadi@intel.com
18432e5d9c85Svenkatesh.pallipadi@intel.com	  If unsure, say Y.
18442e5d9c85Svenkatesh.pallipadi@intel.com
184546cf98cdSVenkatesh Pallipadiconfig ARCH_USES_PG_UNCACHED
184646cf98cdSVenkatesh Pallipadi	def_bool y
184746cf98cdSVenkatesh Pallipadi	depends on X86_PAT
184846cf98cdSVenkatesh Pallipadi
1849628c6246SH. Peter Anvinconfig ARCH_RANDOM
1850628c6246SH. Peter Anvin	def_bool y
1851628c6246SH. Peter Anvin	prompt "x86 architectural random number generator" if EXPERT
1852628c6246SH. Peter Anvin	---help---
1853628c6246SH. Peter Anvin	  Enable the x86 architectural RDRAND instruction
1854628c6246SH. Peter Anvin	  (Intel Bull Mountain technology) to generate random numbers.
1855628c6246SH. Peter Anvin	  If supported, this is a high bandwidth, cryptographically
1856628c6246SH. Peter Anvin	  secure hardware random number generator.
1857628c6246SH. Peter Anvin
185851ae4a2dSH. Peter Anvinconfig X86_SMAP
185951ae4a2dSH. Peter Anvin	def_bool y
186051ae4a2dSH. Peter Anvin	prompt "Supervisor Mode Access Prevention" if EXPERT
186151ae4a2dSH. Peter Anvin	---help---
186251ae4a2dSH. Peter Anvin	  Supervisor Mode Access Prevention (SMAP) is a security
186351ae4a2dSH. Peter Anvin	  feature in newer Intel processors.  There is a small
186451ae4a2dSH. Peter Anvin	  performance cost if this enabled and turned on; there is
186551ae4a2dSH. Peter Anvin	  also a small increase in the kernel size if this is enabled.
186651ae4a2dSH. Peter Anvin
186751ae4a2dSH. Peter Anvin	  If unsure, say Y.
186851ae4a2dSH. Peter Anvin
1869aa35f896SRicardo Nericonfig X86_INTEL_UMIP
1870796ebc81SRicardo Neri	def_bool y
1871aa35f896SRicardo Neri	depends on CPU_SUP_INTEL
1872aa35f896SRicardo Neri	prompt "Intel User Mode Instruction Prevention" if EXPERT
1873aa35f896SRicardo Neri	---help---
1874aa35f896SRicardo Neri	  The User Mode Instruction Prevention (UMIP) is a security
1875aa35f896SRicardo Neri	  feature in newer Intel processors. If enabled, a general
1876796ebc81SRicardo Neri	  protection fault is issued if the SGDT, SLDT, SIDT, SMSW
1877796ebc81SRicardo Neri	  or STR instructions are executed in user mode. These instructions
1878796ebc81SRicardo Neri	  unnecessarily expose information about the hardware state.
1879796ebc81SRicardo Neri
1880796ebc81SRicardo Neri	  The vast majority of applications do not use these instructions.
1881796ebc81SRicardo Neri	  For the very few that do, software emulation is provided in
1882796ebc81SRicardo Neri	  specific cases in protected and virtual-8086 modes. Emulated
1883796ebc81SRicardo Neri	  results are dummy.
1884aa35f896SRicardo Neri
188572e9b5feSDave Hansenconfig X86_INTEL_MPX
188672e9b5feSDave Hansen	prompt "Intel MPX (Memory Protection Extensions)"
188772e9b5feSDave Hansen	def_bool n
1888df3735c5SRik van Riel	# Note: only available in 64-bit mode due to VMA flags shortage
1889df3735c5SRik van Riel	depends on CPU_SUP_INTEL && X86_64
1890df3735c5SRik van Riel	select ARCH_USES_HIGH_VMA_FLAGS
189172e9b5feSDave Hansen	---help---
189272e9b5feSDave Hansen	  MPX provides hardware features that can be used in
189372e9b5feSDave Hansen	  conjunction with compiler-instrumented code to check
189472e9b5feSDave Hansen	  memory references.  It is designed to detect buffer
189572e9b5feSDave Hansen	  overflow or underflow bugs.
189672e9b5feSDave Hansen
189772e9b5feSDave Hansen	  This option enables running applications which are
189872e9b5feSDave Hansen	  instrumented or otherwise use MPX.  It does not use MPX
189972e9b5feSDave Hansen	  itself inside the kernel or to protect the kernel
190072e9b5feSDave Hansen	  against bad memory references.
190172e9b5feSDave Hansen
190272e9b5feSDave Hansen	  Enabling this option will make the kernel larger:
190372e9b5feSDave Hansen	  ~8k of kernel text and 36 bytes of data on a 64-bit
190472e9b5feSDave Hansen	  defconfig.  It adds a long to the 'mm_struct' which
190572e9b5feSDave Hansen	  will increase the kernel memory overhead of each
190672e9b5feSDave Hansen	  process and adds some branches to paths used during
190772e9b5feSDave Hansen	  exec() and munmap().
190872e9b5feSDave Hansen
190972e9b5feSDave Hansen	  For details, see Documentation/x86/intel_mpx.txt
191072e9b5feSDave Hansen
191172e9b5feSDave Hansen	  If unsure, say N.
191272e9b5feSDave Hansen
191335e97790SDave Hansenconfig X86_INTEL_MEMORY_PROTECTION_KEYS
1914284244a9SDave Hansen	prompt "Intel Memory Protection Keys"
191535e97790SDave Hansen	def_bool y
1916284244a9SDave Hansen	# Note: only available in 64-bit mode
191735e97790SDave Hansen	depends on CPU_SUP_INTEL && X86_64
191852c8e601SIngo Molnar	select ARCH_USES_HIGH_VMA_FLAGS
191952c8e601SIngo Molnar	select ARCH_HAS_PKEYS
1920284244a9SDave Hansen	---help---
1921284244a9SDave Hansen	  Memory Protection Keys provides a mechanism for enforcing
1922284244a9SDave Hansen	  page-based protections, but without requiring modification of the
1923284244a9SDave Hansen	  page tables when an application changes protection domains.
1924284244a9SDave Hansen
1925284244a9SDave Hansen	  For details, see Documentation/x86/protection-keys.txt
1926284244a9SDave Hansen
1927284244a9SDave Hansen	  If unsure, say y.
192835e97790SDave Hansen
1929506f1d07SSam Ravnborgconfig EFI
19309ba16087SJan Beulich	bool "EFI runtime service support"
19315b83683fSHuang, Ying	depends on ACPI
1932f6ce5002SSergey Vlasov	select UCS2_STRING
1933022ee6c5SArd Biesheuvel	select EFI_RUNTIME_WRAPPERS
1934506f1d07SSam Ravnborg	---help---
19358b2cb7a8SHuang, Ying	  This enables the kernel to use EFI runtime services that are
1936506f1d07SSam Ravnborg	  available (such as the EFI variable services).
1937506f1d07SSam Ravnborg
19388b2cb7a8SHuang, Ying	  This option is only useful on systems that have EFI firmware.
19398b2cb7a8SHuang, Ying	  In addition, you should use the latest ELILO loader available
19408b2cb7a8SHuang, Ying	  at <http://elilo.sourceforge.net> in order to take advantage
19418b2cb7a8SHuang, Ying	  of EFI runtime services. However, even with this option, the
19428b2cb7a8SHuang, Ying	  resultant kernel should continue to boot on existing non-EFI
19438b2cb7a8SHuang, Ying	  platforms.
1944506f1d07SSam Ravnborg
1945291f3632SMatt Flemingconfig EFI_STUB
1946291f3632SMatt Fleming       bool "EFI stub support"
1947b16d8c23SMatt Fleming       depends on EFI && !X86_USE_3DNOW
19487b2a583aSMatt Fleming       select RELOCATABLE
1949291f3632SMatt Fleming       ---help---
1950291f3632SMatt Fleming          This kernel feature allows a bzImage to be loaded directly
1951291f3632SMatt Fleming	  by EFI firmware without the use of a bootloader.
1952291f3632SMatt Fleming
19534172fe2fSRoy Franz	  See Documentation/efi-stub.txt for more information.
19540c759662SMatt Fleming
19557d453eeeSMatt Flemingconfig EFI_MIXED
19567d453eeeSMatt Fleming	bool "EFI mixed-mode support"
19577d453eeeSMatt Fleming	depends on EFI_STUB && X86_64
19587d453eeeSMatt Fleming	---help---
19597d453eeeSMatt Fleming	   Enabling this feature allows a 64-bit kernel to be booted
19607d453eeeSMatt Fleming	   on a 32-bit firmware, provided that your CPU supports 64-bit
19617d453eeeSMatt Fleming	   mode.
19627d453eeeSMatt Fleming
19637d453eeeSMatt Fleming	   Note that it is not possible to boot a mixed-mode enabled
19647d453eeeSMatt Fleming	   kernel via the EFI boot stub - a bootloader that supports
19657d453eeeSMatt Fleming	   the EFI handover protocol must be used.
19667d453eeeSMatt Fleming
19677d453eeeSMatt Fleming	   If unsure, say N.
19687d453eeeSMatt Fleming
1969506f1d07SSam Ravnborgconfig SECCOMP
19703c2362e6SHarvey Harrison	def_bool y
19713c2362e6SHarvey Harrison	prompt "Enable seccomp to safely compute untrusted bytecode"
19728f9ca475SIngo Molnar	---help---
1973506f1d07SSam Ravnborg	  This kernel feature is useful for number crunching applications
1974506f1d07SSam Ravnborg	  that may need to compute untrusted bytecode during their
1975506f1d07SSam Ravnborg	  execution. By using pipes or other transports made available to
1976506f1d07SSam Ravnborg	  the process as file descriptors supporting the read/write
1977506f1d07SSam Ravnborg	  syscalls, it's possible to isolate those applications in
1978506f1d07SSam Ravnborg	  their own address space using seccomp. Once seccomp is
19799c0bbee8SAlexey Dobriyan	  enabled via prctl(PR_SET_SECCOMP), it cannot be disabled
1980506f1d07SSam Ravnborg	  and the task is only allowed to execute a few safe syscalls
1981506f1d07SSam Ravnborg	  defined by each seccomp mode.
1982506f1d07SSam Ravnborg
1983506f1d07SSam Ravnborg	  If unsure, say Y. Only embedded should say N here.
1984506f1d07SSam Ravnborg
19858636a1f9SMasahiro Yamadasource "kernel/Kconfig.hz"
1986506f1d07SSam Ravnborg
1987506f1d07SSam Ravnborgconfig KEXEC
1988506f1d07SSam Ravnborg	bool "kexec system call"
19892965faa5SDave Young	select KEXEC_CORE
19908f9ca475SIngo Molnar	---help---
1991506f1d07SSam Ravnborg	  kexec is a system call that implements the ability to shutdown your
1992506f1d07SSam Ravnborg	  current kernel, and to start another kernel.  It is like a reboot
1993506f1d07SSam Ravnborg	  but it is independent of the system firmware.   And like a reboot
1994506f1d07SSam Ravnborg	  you can start any kernel with it, not just Linux.
1995506f1d07SSam Ravnborg
1996506f1d07SSam Ravnborg	  The name comes from the similarity to the exec system call.
1997506f1d07SSam Ravnborg
1998506f1d07SSam Ravnborg	  It is an ongoing process to be certain the hardware in a machine
1999506f1d07SSam Ravnborg	  is properly shutdown, so do not be surprised if this code does not
2000bf220695SGeert Uytterhoeven	  initially work for you.  As of this writing the exact hardware
2001bf220695SGeert Uytterhoeven	  interface is strongly in flux, so no good recommendation can be
2002bf220695SGeert Uytterhoeven	  made.
2003506f1d07SSam Ravnborg
200474ca317cSVivek Goyalconfig KEXEC_FILE
200574ca317cSVivek Goyal	bool "kexec file based system call"
20062965faa5SDave Young	select KEXEC_CORE
200774ca317cSVivek Goyal	select BUILD_BIN2C
200874ca317cSVivek Goyal	depends on X86_64
200974ca317cSVivek Goyal	depends on CRYPTO=y
201074ca317cSVivek Goyal	depends on CRYPTO_SHA256=y
201174ca317cSVivek Goyal	---help---
201274ca317cSVivek Goyal	  This is new version of kexec system call. This system call is
201374ca317cSVivek Goyal	  file based and takes file descriptors as system call argument
201474ca317cSVivek Goyal	  for kernel and initramfs as opposed to list of segments as
201574ca317cSVivek Goyal	  accepted by previous system call.
201674ca317cSVivek Goyal
2017b799a09fSAKASHI Takahiroconfig ARCH_HAS_KEXEC_PURGATORY
2018b799a09fSAKASHI Takahiro	def_bool KEXEC_FILE
2019b799a09fSAKASHI Takahiro
20208e7d8381SVivek Goyalconfig KEXEC_VERIFY_SIG
20218e7d8381SVivek Goyal	bool "Verify kernel signature during kexec_file_load() syscall"
202274ca317cSVivek Goyal	depends on KEXEC_FILE
20238e7d8381SVivek Goyal	---help---
20248e7d8381SVivek Goyal	  This option makes kernel signature verification mandatory for
2025d8eb8940SBorislav Petkov	  the kexec_file_load() syscall.
20268e7d8381SVivek Goyal
2027d8eb8940SBorislav Petkov	  In addition to that option, you need to enable signature
2028d8eb8940SBorislav Petkov	  verification for the corresponding kernel image type being
2029d8eb8940SBorislav Petkov	  loaded in order for this to work.
20308e7d8381SVivek Goyal
20318e7d8381SVivek Goyalconfig KEXEC_BZIMAGE_VERIFY_SIG
20328e7d8381SVivek Goyal	bool "Enable bzImage signature verification support"
20338e7d8381SVivek Goyal	depends on KEXEC_VERIFY_SIG
20348e7d8381SVivek Goyal	depends on SIGNED_PE_FILE_VERIFICATION
20358e7d8381SVivek Goyal	select SYSTEM_TRUSTED_KEYRING
20368e7d8381SVivek Goyal	---help---
20378e7d8381SVivek Goyal	  Enable bzImage signature verification support.
20388e7d8381SVivek Goyal
2039506f1d07SSam Ravnborgconfig CRASH_DUMP
204004b69447SPavel Machek	bool "kernel crash dumps"
2041506f1d07SSam Ravnborg	depends on X86_64 || (X86_32 && HIGHMEM)
20428f9ca475SIngo Molnar	---help---
2043506f1d07SSam Ravnborg	  Generate crash dump after being started by kexec.
2044506f1d07SSam Ravnborg	  This should be normally only set in special crash dump kernels
2045506f1d07SSam Ravnborg	  which are loaded in the main kernel with kexec-tools into
2046506f1d07SSam Ravnborg	  a specially reserved region and then later executed after
2047506f1d07SSam Ravnborg	  a crash by kdump/kexec. The crash dump kernel must be compiled
2048506f1d07SSam Ravnborg	  to a memory address not used by the main kernel or BIOS using
2049506f1d07SSam Ravnborg	  PHYSICAL_START, or it must be built as a relocatable image
2050506f1d07SSam Ravnborg	  (CONFIG_RELOCATABLE=y).
2051506f1d07SSam Ravnborg	  For more details see Documentation/kdump/kdump.txt
2052506f1d07SSam Ravnborg
20533ab83521SHuang Yingconfig KEXEC_JUMP
20546ea30386SKees Cook	bool "kexec jump"
2055fee7b0d8SHuang Ying	depends on KEXEC && HIBERNATION
20568f9ca475SIngo Molnar	---help---
205789081d17SHuang Ying	  Jump between original kernel and kexeced kernel and invoke
205889081d17SHuang Ying	  code in physical address mode via KEXEC
20593ab83521SHuang Ying
2060506f1d07SSam Ravnborgconfig PHYSICAL_START
20616a108a14SDavid Rientjes	hex "Physical address where the kernel is loaded" if (EXPERT || CRASH_DUMP)
2062ceefccc9SH. Peter Anvin	default "0x1000000"
20638f9ca475SIngo Molnar	---help---
2064506f1d07SSam Ravnborg	  This gives the physical address where the kernel is loaded.
2065506f1d07SSam Ravnborg
2066506f1d07SSam Ravnborg	  If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then
2067506f1d07SSam Ravnborg	  bzImage will decompress itself to above physical address and
2068506f1d07SSam Ravnborg	  run from there. Otherwise, bzImage will run from the address where
2069506f1d07SSam Ravnborg	  it has been loaded by the boot loader and will ignore above physical
2070506f1d07SSam Ravnborg	  address.
2071506f1d07SSam Ravnborg
2072506f1d07SSam Ravnborg	  In normal kdump cases one does not have to set/change this option
2073506f1d07SSam Ravnborg	  as now bzImage can be compiled as a completely relocatable image
2074506f1d07SSam Ravnborg	  (CONFIG_RELOCATABLE=y) and be used to load and run from a different
2075506f1d07SSam Ravnborg	  address. This option is mainly useful for the folks who don't want
2076506f1d07SSam Ravnborg	  to use a bzImage for capturing the crash dump and want to use a
2077506f1d07SSam Ravnborg	  vmlinux instead. vmlinux is not relocatable hence a kernel needs
2078506f1d07SSam Ravnborg	  to be specifically compiled to run from a specific memory area
2079506f1d07SSam Ravnborg	  (normally a reserved region) and this option comes handy.
2080506f1d07SSam Ravnborg
2081ceefccc9SH. Peter Anvin	  So if you are using bzImage for capturing the crash dump,
2082ceefccc9SH. Peter Anvin	  leave the value here unchanged to 0x1000000 and set
2083ceefccc9SH. Peter Anvin	  CONFIG_RELOCATABLE=y.  Otherwise if you plan to use vmlinux
2084ceefccc9SH. Peter Anvin	  for capturing the crash dump change this value to start of
2085ceefccc9SH. Peter Anvin	  the reserved region.  In other words, it can be set based on
2086ceefccc9SH. Peter Anvin	  the "X" value as specified in the "crashkernel=YM@XM"
2087ceefccc9SH. Peter Anvin	  command line boot parameter passed to the panic-ed
2088ceefccc9SH. Peter Anvin	  kernel. Please take a look at Documentation/kdump/kdump.txt
2089ceefccc9SH. Peter Anvin	  for more details about crash dumps.
2090506f1d07SSam Ravnborg
2091506f1d07SSam Ravnborg	  Usage of bzImage for capturing the crash dump is recommended as
2092506f1d07SSam Ravnborg	  one does not have to build two kernels. Same kernel can be used
2093506f1d07SSam Ravnborg	  as production kernel and capture kernel. Above option should have
2094506f1d07SSam Ravnborg	  gone away after relocatable bzImage support is introduced. But it
2095506f1d07SSam Ravnborg	  is present because there are users out there who continue to use
2096506f1d07SSam Ravnborg	  vmlinux for dump capture. This option should go away down the
2097506f1d07SSam Ravnborg	  line.
2098506f1d07SSam Ravnborg
2099506f1d07SSam Ravnborg	  Don't change this unless you know what you are doing.
2100506f1d07SSam Ravnborg
2101506f1d07SSam Ravnborgconfig RELOCATABLE
210226717808SH. Peter Anvin	bool "Build a relocatable kernel"
210326717808SH. Peter Anvin	default y
21048f9ca475SIngo Molnar	---help---
2105506f1d07SSam Ravnborg	  This builds a kernel image that retains relocation information
2106506f1d07SSam Ravnborg	  so it can be loaded someplace besides the default 1MB.
2107506f1d07SSam Ravnborg	  The relocations tend to make the kernel binary about 10% larger,
2108506f1d07SSam Ravnborg	  but are discarded at runtime.
2109506f1d07SSam Ravnborg
2110506f1d07SSam Ravnborg	  One use is for the kexec on panic case where the recovery kernel
2111506f1d07SSam Ravnborg	  must live at a different physical address than the primary
2112506f1d07SSam Ravnborg	  kernel.
2113506f1d07SSam Ravnborg
2114506f1d07SSam Ravnborg	  Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address
2115506f1d07SSam Ravnborg	  it has been loaded at and the compile time physical address
21168ab3820fSKees Cook	  (CONFIG_PHYSICAL_START) is used as the minimum location.
2117506f1d07SSam Ravnborg
21188ab3820fSKees Cookconfig RANDOMIZE_BASE
2119e8581e3dSBaoquan He	bool "Randomize the address of the kernel image (KASLR)"
21208ab3820fSKees Cook	depends on RELOCATABLE
21216807c846SIngo Molnar	default y
21228ab3820fSKees Cook	---help---
2123e8581e3dSBaoquan He	  In support of Kernel Address Space Layout Randomization (KASLR),
2124e8581e3dSBaoquan He	  this randomizes the physical address at which the kernel image
2125e8581e3dSBaoquan He	  is decompressed and the virtual address where the kernel
2126e8581e3dSBaoquan He	  image is mapped, as a security feature that deters exploit
2127e8581e3dSBaoquan He	  attempts relying on knowledge of the location of kernel
2128e8581e3dSBaoquan He	  code internals.
2129e8581e3dSBaoquan He
2130ed9f007eSKees Cook	  On 64-bit, the kernel physical and virtual addresses are
2131ed9f007eSKees Cook	  randomized separately. The physical address will be anywhere
2132ed9f007eSKees Cook	  between 16MB and the top of physical memory (up to 64TB). The
2133ed9f007eSKees Cook	  virtual address will be randomized from 16MB up to 1GB (9 bits
2134ed9f007eSKees Cook	  of entropy). Note that this also reduces the memory space
2135ed9f007eSKees Cook	  available to kernel modules from 1.5GB to 1GB.
2136ed9f007eSKees Cook
2137ed9f007eSKees Cook	  On 32-bit, the kernel physical and virtual addresses are
2138ed9f007eSKees Cook	  randomized together. They will be randomized from 16MB up to
2139ed9f007eSKees Cook	  512MB (8 bits of entropy).
21408ab3820fSKees Cook
2141a653f356SKees Cook	  Entropy is generated using the RDRAND instruction if it is
2142e8581e3dSBaoquan He	  supported. If RDTSC is supported, its value is mixed into
2143e8581e3dSBaoquan He	  the entropy pool as well. If neither RDRAND nor RDTSC are
2144ed9f007eSKees Cook	  supported, then entropy is read from the i8254 timer. The
2145ed9f007eSKees Cook	  usable entropy is limited by the kernel being built using
2146ed9f007eSKees Cook	  2GB addressing, and that PHYSICAL_ALIGN must be at a
2147ed9f007eSKees Cook	  minimum of 2MB. As a result, only 10 bits of entropy are
2148ed9f007eSKees Cook	  theoretically possible, but the implementations are further
2149ed9f007eSKees Cook	  limited due to memory layouts.
2150e8581e3dSBaoquan He
21516807c846SIngo Molnar	  If unsure, say Y.
2152da2b6fb9SKees Cook
21538ab3820fSKees Cook# Relocation on x86 needs some additional build support
2154845adf72SH. Peter Anvinconfig X86_NEED_RELOCS
2155845adf72SH. Peter Anvin	def_bool y
21568ab3820fSKees Cook	depends on RANDOMIZE_BASE || (X86_32 && RELOCATABLE)
2157845adf72SH. Peter Anvin
2158506f1d07SSam Ravnborgconfig PHYSICAL_ALIGN
2159a0215061SKees Cook	hex "Alignment value to which kernel should be aligned"
21608ab3820fSKees Cook	default "0x200000"
2161a0215061SKees Cook	range 0x2000 0x1000000 if X86_32
2162a0215061SKees Cook	range 0x200000 0x1000000 if X86_64
21638f9ca475SIngo Molnar	---help---
2164506f1d07SSam Ravnborg	  This value puts the alignment restrictions on physical address
2165506f1d07SSam Ravnborg	  where kernel is loaded and run from. Kernel is compiled for an
2166506f1d07SSam Ravnborg	  address which meets above alignment restriction.
2167506f1d07SSam Ravnborg
2168506f1d07SSam Ravnborg	  If bootloader loads the kernel at a non-aligned address and
2169506f1d07SSam Ravnborg	  CONFIG_RELOCATABLE is set, kernel will move itself to nearest
2170506f1d07SSam Ravnborg	  address aligned to above value and run from there.
2171506f1d07SSam Ravnborg
2172506f1d07SSam Ravnborg	  If bootloader loads the kernel at a non-aligned address and
2173506f1d07SSam Ravnborg	  CONFIG_RELOCATABLE is not set, kernel will ignore the run time
2174506f1d07SSam Ravnborg	  load address and decompress itself to the address it has been
2175506f1d07SSam Ravnborg	  compiled for and run from there. The address for which kernel is
2176506f1d07SSam Ravnborg	  compiled already meets above alignment restrictions. Hence the
2177506f1d07SSam Ravnborg	  end result is that kernel runs from a physical address meeting
2178506f1d07SSam Ravnborg	  above alignment restrictions.
2179506f1d07SSam Ravnborg
2180a0215061SKees Cook	  On 32-bit this value must be a multiple of 0x2000. On 64-bit
2181a0215061SKees Cook	  this value must be a multiple of 0x200000.
2182a0215061SKees Cook
2183506f1d07SSam Ravnborg	  Don't change this unless you know what you are doing.
2184506f1d07SSam Ravnborg
2185eedb92abSKirill A. Shutemovconfig DYNAMIC_MEMORY_LAYOUT
2186eedb92abSKirill A. Shutemov	bool
2187eedb92abSKirill A. Shutemov	---help---
2188eedb92abSKirill A. Shutemov	  This option makes base addresses of vmalloc and vmemmap as well as
2189eedb92abSKirill A. Shutemov	  __PAGE_OFFSET movable during boot.
2190eedb92abSKirill A. Shutemov
21910483e1faSThomas Garnierconfig RANDOMIZE_MEMORY
21920483e1faSThomas Garnier	bool "Randomize the kernel memory sections"
21930483e1faSThomas Garnier	depends on X86_64
21940483e1faSThomas Garnier	depends on RANDOMIZE_BASE
2195eedb92abSKirill A. Shutemov	select DYNAMIC_MEMORY_LAYOUT
21960483e1faSThomas Garnier	default RANDOMIZE_BASE
21970483e1faSThomas Garnier	---help---
21980483e1faSThomas Garnier	   Randomizes the base virtual address of kernel memory sections
21990483e1faSThomas Garnier	   (physical memory mapping, vmalloc & vmemmap). This security feature
22000483e1faSThomas Garnier	   makes exploits relying on predictable memory locations less reliable.
22010483e1faSThomas Garnier
22020483e1faSThomas Garnier	   The order of allocations remains unchanged. Entropy is generated in
22030483e1faSThomas Garnier	   the same way as RANDOMIZE_BASE. Current implementation in the optimal
22040483e1faSThomas Garnier	   configuration have in average 30,000 different possible virtual
22050483e1faSThomas Garnier	   addresses for each memory section.
22060483e1faSThomas Garnier
22076807c846SIngo Molnar	   If unsure, say Y.
22080483e1faSThomas Garnier
220990397a41SThomas Garnierconfig RANDOMIZE_MEMORY_PHYSICAL_PADDING
221090397a41SThomas Garnier	hex "Physical memory mapping padding" if EXPERT
221190397a41SThomas Garnier	depends on RANDOMIZE_MEMORY
221290397a41SThomas Garnier	default "0xa" if MEMORY_HOTPLUG
221390397a41SThomas Garnier	default "0x0"
221490397a41SThomas Garnier	range 0x1 0x40 if MEMORY_HOTPLUG
221590397a41SThomas Garnier	range 0x0 0x40
221690397a41SThomas Garnier	---help---
221790397a41SThomas Garnier	   Define the padding in terabytes added to the existing physical
221890397a41SThomas Garnier	   memory size during kernel memory randomization. It is useful
221990397a41SThomas Garnier	   for memory hotplug support but reduces the entropy available for
222090397a41SThomas Garnier	   address randomization.
222190397a41SThomas Garnier
222290397a41SThomas Garnier	   If unsure, leave at the default value.
222390397a41SThomas Garnier
2224506f1d07SSam Ravnborgconfig HOTPLUG_CPU
22257c13e6a3SDimitri Sivanich	bool "Support for hot-pluggable CPUs"
222640b31360SStephen Rothwell	depends on SMP
2227506f1d07SSam Ravnborg	---help---
22287c13e6a3SDimitri Sivanich	  Say Y here to allow turning CPUs off and on. CPUs can be
22297c13e6a3SDimitri Sivanich	  controlled through /sys/devices/system/cpu.
22307c13e6a3SDimitri Sivanich	  ( Note: power management support will enable this option
22317c13e6a3SDimitri Sivanich	    automatically on SMP systems. )
22327c13e6a3SDimitri Sivanich	  Say N if you want to disable CPU hotplug.
2233506f1d07SSam Ravnborg
223480aa1dffSFenghua Yuconfig BOOTPARAM_HOTPLUG_CPU0
223580aa1dffSFenghua Yu	bool "Set default setting of cpu0_hotpluggable"
22362c922cd0SKees Cook	depends on HOTPLUG_CPU
223780aa1dffSFenghua Yu	---help---
223880aa1dffSFenghua Yu	  Set whether default state of cpu0_hotpluggable is on or off.
223980aa1dffSFenghua Yu
224080aa1dffSFenghua Yu	  Say Y here to enable CPU0 hotplug by default. If this switch
224180aa1dffSFenghua Yu	  is turned on, there is no need to give cpu0_hotplug kernel
224280aa1dffSFenghua Yu	  parameter and the CPU0 hotplug feature is enabled by default.
224380aa1dffSFenghua Yu
224480aa1dffSFenghua Yu	  Please note: there are two known CPU0 dependencies if you want
224580aa1dffSFenghua Yu	  to enable the CPU0 hotplug feature either by this switch or by
224680aa1dffSFenghua Yu	  cpu0_hotplug kernel parameter.
224780aa1dffSFenghua Yu
224880aa1dffSFenghua Yu	  First, resume from hibernate or suspend always starts from CPU0.
224980aa1dffSFenghua Yu	  So hibernate and suspend are prevented if CPU0 is offline.
225080aa1dffSFenghua Yu
225180aa1dffSFenghua Yu	  Second dependency is PIC interrupts always go to CPU0. CPU0 can not
225280aa1dffSFenghua Yu	  offline if any interrupt can not migrate out of CPU0. There may
225380aa1dffSFenghua Yu	  be other CPU0 dependencies.
225480aa1dffSFenghua Yu
225580aa1dffSFenghua Yu	  Please make sure the dependencies are under your control before
225680aa1dffSFenghua Yu	  you enable this feature.
225780aa1dffSFenghua Yu
225880aa1dffSFenghua Yu	  Say N if you don't want to enable CPU0 hotplug feature by default.
225980aa1dffSFenghua Yu	  You still can enable the CPU0 hotplug feature at boot by kernel
226080aa1dffSFenghua Yu	  parameter cpu0_hotplug.
226180aa1dffSFenghua Yu
2262a71c8bc5SFenghua Yuconfig DEBUG_HOTPLUG_CPU0
2263a71c8bc5SFenghua Yu	def_bool n
2264a71c8bc5SFenghua Yu	prompt "Debug CPU0 hotplug"
22652c922cd0SKees Cook	depends on HOTPLUG_CPU
2266a71c8bc5SFenghua Yu	---help---
2267a71c8bc5SFenghua Yu	  Enabling this option offlines CPU0 (if CPU0 can be offlined) as
2268a71c8bc5SFenghua Yu	  soon as possible and boots up userspace with CPU0 offlined. User
2269a71c8bc5SFenghua Yu	  can online CPU0 back after boot time.
2270a71c8bc5SFenghua Yu
2271a71c8bc5SFenghua Yu	  To debug CPU0 hotplug, you need to enable CPU0 offline/online
2272a71c8bc5SFenghua Yu	  feature by either turning on CONFIG_BOOTPARAM_HOTPLUG_CPU0 during
2273a71c8bc5SFenghua Yu	  compilation or giving cpu0_hotplug kernel parameter at boot.
2274a71c8bc5SFenghua Yu
2275a71c8bc5SFenghua Yu	  If unsure, say N.
2276a71c8bc5SFenghua Yu
2277506f1d07SSam Ravnborgconfig COMPAT_VDSO
2278b0b49f26SAndy Lutomirski	def_bool n
2279b0b49f26SAndy Lutomirski	prompt "Disable the 32-bit vDSO (needed for glibc 2.3.3)"
2280953fee1dSIngo Molnar	depends on COMPAT_32
22818f9ca475SIngo Molnar	---help---
2282b0b49f26SAndy Lutomirski	  Certain buggy versions of glibc will crash if they are
2283b0b49f26SAndy Lutomirski	  presented with a 32-bit vDSO that is not mapped at the address
2284b0b49f26SAndy Lutomirski	  indicated in its segment table.
2285e84446deSRandy Dunlap
2286b0b49f26SAndy Lutomirski	  The bug was introduced by f866314b89d56845f55e6f365e18b31ec978ec3a
2287b0b49f26SAndy Lutomirski	  and fixed by 3b3ddb4f7db98ec9e912ccdf54d35df4aa30e04a and
2288b0b49f26SAndy Lutomirski	  49ad572a70b8aeb91e57483a11dd1b77e31c4468.  Glibc 2.3.3 is
2289b0b49f26SAndy Lutomirski	  the only released version with the bug, but OpenSUSE 9
2290b0b49f26SAndy Lutomirski	  contains a buggy "glibc 2.3.2".
2291506f1d07SSam Ravnborg
2292b0b49f26SAndy Lutomirski	  The symptom of the bug is that everything crashes on startup, saying:
2293b0b49f26SAndy Lutomirski	  dl_main: Assertion `(void *) ph->p_vaddr == _rtld_local._dl_sysinfo_dso' failed!
2294b0b49f26SAndy Lutomirski
2295b0b49f26SAndy Lutomirski	  Saying Y here changes the default value of the vdso32 boot
2296b0b49f26SAndy Lutomirski	  option from 1 to 0, which turns off the 32-bit vDSO entirely.
2297b0b49f26SAndy Lutomirski	  This works around the glibc bug but hurts performance.
2298b0b49f26SAndy Lutomirski
2299b0b49f26SAndy Lutomirski	  If unsure, say N: if you are compiling your own kernel, you
2300b0b49f26SAndy Lutomirski	  are unlikely to be using a buggy version of glibc.
2301506f1d07SSam Ravnborg
23023dc33bd3SKees Cookchoice
23033dc33bd3SKees Cook	prompt "vsyscall table for legacy applications"
23043dc33bd3SKees Cook	depends on X86_64
23053dc33bd3SKees Cook	default LEGACY_VSYSCALL_EMULATE
23063dc33bd3SKees Cook	help
23073dc33bd3SKees Cook	  Legacy user code that does not know how to find the vDSO expects
23083dc33bd3SKees Cook	  to be able to issue three syscalls by calling fixed addresses in
23093dc33bd3SKees Cook	  kernel space. Since this location is not randomized with ASLR,
23103dc33bd3SKees Cook	  it can be used to assist security vulnerability exploitation.
23113dc33bd3SKees Cook
23123dc33bd3SKees Cook	  This setting can be changed at boot time via the kernel command
2313076ca272SAndy Lutomirski	  line parameter vsyscall=[emulate|none].
23143dc33bd3SKees Cook
23153dc33bd3SKees Cook	  On a system with recent enough glibc (2.14 or newer) and no
23163dc33bd3SKees Cook	  static binaries, you can say None without a performance penalty
23173dc33bd3SKees Cook	  to improve security.
23183dc33bd3SKees Cook
23193dc33bd3SKees Cook	  If unsure, select "Emulate".
23203dc33bd3SKees Cook
23213dc33bd3SKees Cook	config LEGACY_VSYSCALL_EMULATE
23223dc33bd3SKees Cook		bool "Emulate"
23233dc33bd3SKees Cook		help
23243dc33bd3SKees Cook		  The kernel traps and emulates calls into the fixed
23253dc33bd3SKees Cook		  vsyscall address mapping. This makes the mapping
23263dc33bd3SKees Cook		  non-executable, but it still contains known contents,
23273dc33bd3SKees Cook		  which could be used in certain rare security vulnerability
23283dc33bd3SKees Cook		  exploits. This configuration is recommended when userspace
23293dc33bd3SKees Cook		  still uses the vsyscall area.
23303dc33bd3SKees Cook
23313dc33bd3SKees Cook	config LEGACY_VSYSCALL_NONE
23323dc33bd3SKees Cook		bool "None"
23333dc33bd3SKees Cook		help
23343dc33bd3SKees Cook		  There will be no vsyscall mapping at all. This will
23353dc33bd3SKees Cook		  eliminate any risk of ASLR bypass due to the vsyscall
23363dc33bd3SKees Cook		  fixed address mapping. Attempts to use the vsyscalls
23373dc33bd3SKees Cook		  will be reported to dmesg, so that either old or
23383dc33bd3SKees Cook		  malicious userspace programs can be identified.
23393dc33bd3SKees Cook
23403dc33bd3SKees Cookendchoice
23413dc33bd3SKees Cook
2342516cbf37STim Birdconfig CMDLINE_BOOL
2343516cbf37STim Bird	bool "Built-in kernel command line"
23448f9ca475SIngo Molnar	---help---
2345516cbf37STim Bird	  Allow for specifying boot arguments to the kernel at
2346516cbf37STim Bird	  build time.  On some systems (e.g. embedded ones), it is
2347516cbf37STim Bird	  necessary or convenient to provide some or all of the
2348516cbf37STim Bird	  kernel boot arguments with the kernel itself (that is,
2349516cbf37STim Bird	  to not rely on the boot loader to provide them.)
2350516cbf37STim Bird
2351516cbf37STim Bird	  To compile command line arguments into the kernel,
2352516cbf37STim Bird	  set this option to 'Y', then fill in the
235369711ca1SSébastien Hinderer	  boot arguments in CONFIG_CMDLINE.
2354516cbf37STim Bird
2355516cbf37STim Bird	  Systems with fully functional boot loaders (i.e. non-embedded)
2356516cbf37STim Bird	  should leave this option set to 'N'.
2357516cbf37STim Bird
2358516cbf37STim Birdconfig CMDLINE
2359516cbf37STim Bird	string "Built-in kernel command string"
2360516cbf37STim Bird	depends on CMDLINE_BOOL
2361516cbf37STim Bird	default ""
23628f9ca475SIngo Molnar	---help---
2363516cbf37STim Bird	  Enter arguments here that should be compiled into the kernel
2364516cbf37STim Bird	  image and used at boot time.  If the boot loader provides a
2365516cbf37STim Bird	  command line at boot time, it is appended to this string to
2366516cbf37STim Bird	  form the full kernel command line, when the system boots.
2367516cbf37STim Bird
2368516cbf37STim Bird	  However, you can use the CONFIG_CMDLINE_OVERRIDE option to
2369516cbf37STim Bird	  change this behavior.
2370516cbf37STim Bird
2371516cbf37STim Bird	  In most cases, the command line (whether built-in or provided
2372516cbf37STim Bird	  by the boot loader) should specify the device for the root
2373516cbf37STim Bird	  file system.
2374516cbf37STim Bird
2375516cbf37STim Birdconfig CMDLINE_OVERRIDE
2376516cbf37STim Bird	bool "Built-in command line overrides boot loader arguments"
2377516cbf37STim Bird	depends on CMDLINE_BOOL
23788f9ca475SIngo Molnar	---help---
2379516cbf37STim Bird	  Set this option to 'Y' to have the kernel ignore the boot loader
2380516cbf37STim Bird	  command line, and use ONLY the built-in command line.
2381516cbf37STim Bird
2382516cbf37STim Bird	  This is used to work around broken boot loaders.  This should
2383516cbf37STim Bird	  be set to 'N' under normal conditions.
2384516cbf37STim Bird
2385a5b9e5a2SAndy Lutomirskiconfig MODIFY_LDT_SYSCALL
2386a5b9e5a2SAndy Lutomirski	bool "Enable the LDT (local descriptor table)" if EXPERT
2387a5b9e5a2SAndy Lutomirski	default y
2388a5b9e5a2SAndy Lutomirski	---help---
2389a5b9e5a2SAndy Lutomirski	  Linux can allow user programs to install a per-process x86
2390a5b9e5a2SAndy Lutomirski	  Local Descriptor Table (LDT) using the modify_ldt(2) system
2391a5b9e5a2SAndy Lutomirski	  call.  This is required to run 16-bit or segmented code such as
2392a5b9e5a2SAndy Lutomirski	  DOSEMU or some Wine programs.  It is also used by some very old
2393a5b9e5a2SAndy Lutomirski	  threading libraries.
2394a5b9e5a2SAndy Lutomirski
2395a5b9e5a2SAndy Lutomirski	  Enabling this feature adds a small amount of overhead to
2396a5b9e5a2SAndy Lutomirski	  context switches and increases the low-level kernel attack
2397a5b9e5a2SAndy Lutomirski	  surface.  Disabling it removes the modify_ldt(2) system call.
2398a5b9e5a2SAndy Lutomirski
2399a5b9e5a2SAndy Lutomirski	  Saying 'N' here may make sense for embedded or server kernels.
2400a5b9e5a2SAndy Lutomirski
2401b700e7f0SSeth Jenningssource "kernel/livepatch/Kconfig"
2402b700e7f0SSeth Jennings
2403506f1d07SSam Ravnborgendmenu
2404506f1d07SSam Ravnborg
24053072e413SMichal Hockoconfig ARCH_HAS_ADD_PAGES
24063072e413SMichal Hocko	def_bool y
24073072e413SMichal Hocko	depends on X86_64 && ARCH_ENABLE_MEMORY_HOTPLUG
24083072e413SMichal Hocko
2409506f1d07SSam Ravnborgconfig ARCH_ENABLE_MEMORY_HOTPLUG
2410506f1d07SSam Ravnborg	def_bool y
2411506f1d07SSam Ravnborg	depends on X86_64 || (X86_32 && HIGHMEM)
2412506f1d07SSam Ravnborg
241335551053SGary Hadeconfig ARCH_ENABLE_MEMORY_HOTREMOVE
241435551053SGary Hade	def_bool y
241535551053SGary Hade	depends on MEMORY_HOTPLUG
241635551053SGary Hade
2417e534c7c5SLee Schermerhornconfig USE_PERCPU_NUMA_NODE_ID
2418645a7919STejun Heo	def_bool y
2419e534c7c5SLee Schermerhorn	depends on NUMA
2420e534c7c5SLee Schermerhorn
24219491846fSKirill A. Shutemovconfig ARCH_ENABLE_SPLIT_PMD_PTLOCK
24229491846fSKirill A. Shutemov	def_bool y
24239491846fSKirill A. Shutemov	depends on X86_64 || X86_PAE
24249491846fSKirill A. Shutemov
2425c177c81eSNaoya Horiguchiconfig ARCH_ENABLE_HUGEPAGE_MIGRATION
2426c177c81eSNaoya Horiguchi	def_bool y
2427c177c81eSNaoya Horiguchi	depends on X86_64 && HUGETLB_PAGE && MIGRATION
2428c177c81eSNaoya Horiguchi
24299c670ea3SNaoya Horiguchiconfig ARCH_ENABLE_THP_MIGRATION
24309c670ea3SNaoya Horiguchi	def_bool y
24319c670ea3SNaoya Horiguchi	depends on X86_64 && TRANSPARENT_HUGEPAGE
24329c670ea3SNaoya Horiguchi
2433da85f865SBjorn Helgaasmenu "Power management and ACPI options"
2434e279b6c1SSam Ravnborg
2435e279b6c1SSam Ravnborgconfig ARCH_HIBERNATION_HEADER
24363c2362e6SHarvey Harrison	def_bool y
243744556530SZhimin Gu	depends on HIBERNATION
2438e279b6c1SSam Ravnborg
2439e279b6c1SSam Ravnborgsource "kernel/power/Kconfig"
2440e279b6c1SSam Ravnborg
2441e279b6c1SSam Ravnborgsource "drivers/acpi/Kconfig"
2442e279b6c1SSam Ravnborg
2443efafc8b2SFeng Tangsource "drivers/sfi/Kconfig"
2444efafc8b2SFeng Tang
2445a6b68076SAndi Kleenconfig X86_APM_BOOT
24466fc108a0SJan Beulich	def_bool y
2447282e5aabSPaul Bolle	depends on APM
2448a6b68076SAndi Kleen
2449e279b6c1SSam Ravnborgmenuconfig APM
2450e279b6c1SSam Ravnborg	tristate "APM (Advanced Power Management) BIOS support"
2451efefa6f6SIngo Molnar	depends on X86_32 && PM_SLEEP
2452e279b6c1SSam Ravnborg	---help---
2453e279b6c1SSam Ravnborg	  APM is a BIOS specification for saving power using several different
2454e279b6c1SSam Ravnborg	  techniques. This is mostly useful for battery powered laptops with
2455e279b6c1SSam Ravnborg	  APM compliant BIOSes. If you say Y here, the system time will be
2456e279b6c1SSam Ravnborg	  reset after a RESUME operation, the /proc/apm device will provide
2457e279b6c1SSam Ravnborg	  battery status information, and user-space programs will receive
2458e279b6c1SSam Ravnborg	  notification of APM "events" (e.g. battery status change).
2459e279b6c1SSam Ravnborg
2460e279b6c1SSam Ravnborg	  If you select "Y" here, you can disable actual use of the APM
2461e279b6c1SSam Ravnborg	  BIOS by passing the "apm=off" option to the kernel at boot time.
2462e279b6c1SSam Ravnborg
2463e279b6c1SSam Ravnborg	  Note that the APM support is almost completely disabled for
2464e279b6c1SSam Ravnborg	  machines with more than one CPU.
2465e279b6c1SSam Ravnborg
2466e279b6c1SSam Ravnborg	  In order to use APM, you will need supporting software. For location
24672dc98fd3SMichael Witten	  and more information, read <file:Documentation/power/apm-acpi.txt>
24682dc98fd3SMichael Witten	  and the Battery Powered Linux mini-HOWTO, available from
2469e279b6c1SSam Ravnborg	  <http://www.tldp.org/docs.html#howto>.
2470e279b6c1SSam Ravnborg
2471e279b6c1SSam Ravnborg	  This driver does not spin down disk drives (see the hdparm(8)
2472e279b6c1SSam Ravnborg	  manpage ("man 8 hdparm") for that), and it doesn't turn off
2473e279b6c1SSam Ravnborg	  VESA-compliant "green" monitors.
2474e279b6c1SSam Ravnborg
2475e279b6c1SSam Ravnborg	  This driver does not support the TI 4000M TravelMate and the ACER
2476e279b6c1SSam Ravnborg	  486/DX4/75 because they don't have compliant BIOSes. Many "green"
2477e279b6c1SSam Ravnborg	  desktop machines also don't have compliant BIOSes, and this driver
2478e279b6c1SSam Ravnborg	  may cause those machines to panic during the boot phase.
2479e279b6c1SSam Ravnborg
2480e279b6c1SSam Ravnborg	  Generally, if you don't have a battery in your machine, there isn't
2481e279b6c1SSam Ravnborg	  much point in using this driver and you should say N. If you get
2482e279b6c1SSam Ravnborg	  random kernel OOPSes or reboots that don't seem to be related to
2483e279b6c1SSam Ravnborg	  anything, try disabling/enabling this option (or disabling/enabling
2484e279b6c1SSam Ravnborg	  APM in your BIOS).
2485e279b6c1SSam Ravnborg
2486e279b6c1SSam Ravnborg	  Some other things you should try when experiencing seemingly random,
2487e279b6c1SSam Ravnborg	  "weird" problems:
2488e279b6c1SSam Ravnborg
2489e279b6c1SSam Ravnborg	  1) make sure that you have enough swap space and that it is
2490e279b6c1SSam Ravnborg	  enabled.
2491e279b6c1SSam Ravnborg	  2) pass the "no-hlt" option to the kernel
2492e279b6c1SSam Ravnborg	  3) switch on floating point emulation in the kernel and pass
2493e279b6c1SSam Ravnborg	  the "no387" option to the kernel
2494e279b6c1SSam Ravnborg	  4) pass the "floppy=nodma" option to the kernel
2495e279b6c1SSam Ravnborg	  5) pass the "mem=4M" option to the kernel (thereby disabling
2496e279b6c1SSam Ravnborg	  all but the first 4 MB of RAM)
2497e279b6c1SSam Ravnborg	  6) make sure that the CPU is not over clocked.
2498e279b6c1SSam Ravnborg	  7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/>
2499e279b6c1SSam Ravnborg	  8) disable the cache from your BIOS settings
2500e279b6c1SSam Ravnborg	  9) install a fan for the video card or exchange video RAM
2501e279b6c1SSam Ravnborg	  10) install a better fan for the CPU
2502e279b6c1SSam Ravnborg	  11) exchange RAM chips
2503e279b6c1SSam Ravnborg	  12) exchange the motherboard.
2504e279b6c1SSam Ravnborg
2505e279b6c1SSam Ravnborg	  To compile this driver as a module, choose M here: the
2506e279b6c1SSam Ravnborg	  module will be called apm.
2507e279b6c1SSam Ravnborg
2508e279b6c1SSam Ravnborgif APM
2509e279b6c1SSam Ravnborg
2510e279b6c1SSam Ravnborgconfig APM_IGNORE_USER_SUSPEND
2511e279b6c1SSam Ravnborg	bool "Ignore USER SUSPEND"
25128f9ca475SIngo Molnar	---help---
2513e279b6c1SSam Ravnborg	  This option will ignore USER SUSPEND requests. On machines with a
2514e279b6c1SSam Ravnborg	  compliant APM BIOS, you want to say N. However, on the NEC Versa M
2515e279b6c1SSam Ravnborg	  series notebooks, it is necessary to say Y because of a BIOS bug.
2516e279b6c1SSam Ravnborg
2517e279b6c1SSam Ravnborgconfig APM_DO_ENABLE
2518e279b6c1SSam Ravnborg	bool "Enable PM at boot time"
2519e279b6c1SSam Ravnborg	---help---
2520e279b6c1SSam Ravnborg	  Enable APM features at boot time. From page 36 of the APM BIOS
2521e279b6c1SSam Ravnborg	  specification: "When disabled, the APM BIOS does not automatically
2522e279b6c1SSam Ravnborg	  power manage devices, enter the Standby State, enter the Suspend
2523e279b6c1SSam Ravnborg	  State, or take power saving steps in response to CPU Idle calls."
2524e279b6c1SSam Ravnborg	  This driver will make CPU Idle calls when Linux is idle (unless this
2525e279b6c1SSam Ravnborg	  feature is turned off -- see "Do CPU IDLE calls", below). This
2526e279b6c1SSam Ravnborg	  should always save battery power, but more complicated APM features
2527e279b6c1SSam Ravnborg	  will be dependent on your BIOS implementation. You may need to turn
2528e279b6c1SSam Ravnborg	  this option off if your computer hangs at boot time when using APM
2529e279b6c1SSam Ravnborg	  support, or if it beeps continuously instead of suspending. Turn
2530e279b6c1SSam Ravnborg	  this off if you have a NEC UltraLite Versa 33/C or a Toshiba
2531e279b6c1SSam Ravnborg	  T400CDT. This is off by default since most machines do fine without
2532e279b6c1SSam Ravnborg	  this feature.
2533e279b6c1SSam Ravnborg
2534e279b6c1SSam Ravnborgconfig APM_CPU_IDLE
2535dd8af076SLen Brown	depends on CPU_IDLE
2536e279b6c1SSam Ravnborg	bool "Make CPU Idle calls when idle"
25378f9ca475SIngo Molnar	---help---
2538e279b6c1SSam Ravnborg	  Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop.
2539e279b6c1SSam Ravnborg	  On some machines, this can activate improved power savings, such as
2540e279b6c1SSam Ravnborg	  a slowed CPU clock rate, when the machine is idle. These idle calls
2541e279b6c1SSam Ravnborg	  are made after the idle loop has run for some length of time (e.g.,
2542e279b6c1SSam Ravnborg	  333 mS). On some machines, this will cause a hang at boot time or
2543e279b6c1SSam Ravnborg	  whenever the CPU becomes idle. (On machines with more than one CPU,
2544e279b6c1SSam Ravnborg	  this option does nothing.)
2545e279b6c1SSam Ravnborg
2546e279b6c1SSam Ravnborgconfig APM_DISPLAY_BLANK
2547e279b6c1SSam Ravnborg	bool "Enable console blanking using APM"
25488f9ca475SIngo Molnar	---help---
2549e279b6c1SSam Ravnborg	  Enable console blanking using the APM. Some laptops can use this to
2550e279b6c1SSam Ravnborg	  turn off the LCD backlight when the screen blanker of the Linux
2551e279b6c1SSam Ravnborg	  virtual console blanks the screen. Note that this is only used by
2552e279b6c1SSam Ravnborg	  the virtual console screen blanker, and won't turn off the backlight
2553e279b6c1SSam Ravnborg	  when using the X Window system. This also doesn't have anything to
2554e279b6c1SSam Ravnborg	  do with your VESA-compliant power-saving monitor. Further, this
2555e279b6c1SSam Ravnborg	  option doesn't work for all laptops -- it might not turn off your
2556e279b6c1SSam Ravnborg	  backlight at all, or it might print a lot of errors to the console,
2557e279b6c1SSam Ravnborg	  especially if you are using gpm.
2558e279b6c1SSam Ravnborg
2559e279b6c1SSam Ravnborgconfig APM_ALLOW_INTS
2560e279b6c1SSam Ravnborg	bool "Allow interrupts during APM BIOS calls"
25618f9ca475SIngo Molnar	---help---
2562e279b6c1SSam Ravnborg	  Normally we disable external interrupts while we are making calls to
2563e279b6c1SSam Ravnborg	  the APM BIOS as a measure to lessen the effects of a badly behaving
2564e279b6c1SSam Ravnborg	  BIOS implementation.  The BIOS should reenable interrupts if it
2565e279b6c1SSam Ravnborg	  needs to.  Unfortunately, some BIOSes do not -- especially those in
2566e279b6c1SSam Ravnborg	  many of the newer IBM Thinkpads.  If you experience hangs when you
2567e279b6c1SSam Ravnborg	  suspend, try setting this to Y.  Otherwise, say N.
2568e279b6c1SSam Ravnborg
2569e279b6c1SSam Ravnborgendif # APM
2570e279b6c1SSam Ravnborg
2571bb0a56ecSDave Jonessource "drivers/cpufreq/Kconfig"
2572e279b6c1SSam Ravnborg
2573e279b6c1SSam Ravnborgsource "drivers/cpuidle/Kconfig"
2574e279b6c1SSam Ravnborg
257527471fdbSAndy Henroidsource "drivers/idle/Kconfig"
257627471fdbSAndy Henroid
2577e279b6c1SSam Ravnborgendmenu
2578e279b6c1SSam Ravnborg
2579e279b6c1SSam Ravnborg
2580e279b6c1SSam Ravnborgmenu "Bus options (PCI etc.)"
2581e279b6c1SSam Ravnborg
2582e279b6c1SSam Ravnborgchoice
2583e279b6c1SSam Ravnborg	prompt "PCI access mode"
2584efefa6f6SIngo Molnar	depends on X86_32 && PCI
2585e279b6c1SSam Ravnborg	default PCI_GOANY
2586e279b6c1SSam Ravnborg	---help---
2587e279b6c1SSam Ravnborg	  On PCI systems, the BIOS can be used to detect the PCI devices and
2588e279b6c1SSam Ravnborg	  determine their configuration. However, some old PCI motherboards
2589e279b6c1SSam Ravnborg	  have BIOS bugs and may crash if this is done. Also, some embedded
2590e279b6c1SSam Ravnborg	  PCI-based systems don't have any BIOS at all. Linux can also try to
2591e279b6c1SSam Ravnborg	  detect the PCI hardware directly without using the BIOS.
2592e279b6c1SSam Ravnborg
2593e279b6c1SSam Ravnborg	  With this option, you can specify how Linux should detect the
2594e279b6c1SSam Ravnborg	  PCI devices. If you choose "BIOS", the BIOS will be used,
2595e279b6c1SSam Ravnborg	  if you choose "Direct", the BIOS won't be used, and if you
2596e279b6c1SSam Ravnborg	  choose "MMConfig", then PCI Express MMCONFIG will be used.
2597e279b6c1SSam Ravnborg	  If you choose "Any", the kernel will try MMCONFIG, then the
2598e279b6c1SSam Ravnborg	  direct access method and falls back to the BIOS if that doesn't
2599e279b6c1SSam Ravnborg	  work. If unsure, go with the default, which is "Any".
2600e279b6c1SSam Ravnborg
2601e279b6c1SSam Ravnborgconfig PCI_GOBIOS
2602e279b6c1SSam Ravnborg	bool "BIOS"
2603e279b6c1SSam Ravnborg
2604e279b6c1SSam Ravnborgconfig PCI_GOMMCONFIG
2605e279b6c1SSam Ravnborg	bool "MMConfig"
2606e279b6c1SSam Ravnborg
2607e279b6c1SSam Ravnborgconfig PCI_GODIRECT
2608e279b6c1SSam Ravnborg	bool "Direct"
2609e279b6c1SSam Ravnborg
26103ef0e1f8SAndres Salomonconfig PCI_GOOLPC
261176fb6570SDaniel Drake	bool "OLPC XO-1"
26123ef0e1f8SAndres Salomon	depends on OLPC
26133ef0e1f8SAndres Salomon
26142bdd1b03SAndres Salomonconfig PCI_GOANY
26152bdd1b03SAndres Salomon	bool "Any"
26162bdd1b03SAndres Salomon
2617e279b6c1SSam Ravnborgendchoice
2618e279b6c1SSam Ravnborg
2619e279b6c1SSam Ravnborgconfig PCI_BIOS
26203c2362e6SHarvey Harrison	def_bool y
2621efefa6f6SIngo Molnar	depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY)
2622e279b6c1SSam Ravnborg
2623e279b6c1SSam Ravnborg# x86-64 doesn't support PCI BIOS access from long mode so always go direct.
2624e279b6c1SSam Ravnborgconfig PCI_DIRECT
26253c2362e6SHarvey Harrison	def_bool y
26260aba496fSShaohua Li	depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC || PCI_GOMMCONFIG))
2627e279b6c1SSam Ravnborg
2628e279b6c1SSam Ravnborgconfig PCI_MMCONFIG
2629b45c9f36SJan Kiszka	bool "Support mmconfig PCI config space access" if X86_64
2630b45c9f36SJan Kiszka	default y
26318364e1f8SJan Kiszka	depends on PCI && (ACPI || SFI || JAILHOUSE_GUEST)
2632b45c9f36SJan Kiszka	depends on X86_64 || (PCI_GOANY || PCI_GOMMCONFIG)
2633e279b6c1SSam Ravnborg
26343ef0e1f8SAndres Salomonconfig PCI_OLPC
26352bdd1b03SAndres Salomon	def_bool y
26362bdd1b03SAndres Salomon	depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY)
26373ef0e1f8SAndres Salomon
2638b5401a96SAlex Nixonconfig PCI_XEN
2639b5401a96SAlex Nixon	def_bool y
2640b5401a96SAlex Nixon	depends on PCI && XEN
2641b5401a96SAlex Nixon	select SWIOTLB_XEN
2642b5401a96SAlex Nixon
26438364e1f8SJan Kiszkaconfig MMCONF_FAM10H
26448364e1f8SJan Kiszka	def_bool y
26458364e1f8SJan Kiszka	depends on X86_64 && PCI_MMCONFIG && ACPI
2646e279b6c1SSam Ravnborg
26473f6ea84aSIra W. Snyderconfig PCI_CNB20LE_QUIRK
26486a108a14SDavid Rientjes	bool "Read CNB20LE Host Bridge Windows" if EXPERT
26496ea30386SKees Cook	depends on PCI
26503f6ea84aSIra W. Snyder	help
26513f6ea84aSIra W. Snyder	  Read the PCI windows out of the CNB20LE host bridge. This allows
26523f6ea84aSIra W. Snyder	  PCI hotplug to work on systems with the CNB20LE chipset which do
26533f6ea84aSIra W. Snyder	  not have ACPI.
26543f6ea84aSIra W. Snyder
265564a5fed6SBjorn Helgaas	  There's no public spec for this chipset, and this functionality
265664a5fed6SBjorn Helgaas	  is known to be incomplete.
265764a5fed6SBjorn Helgaas
265864a5fed6SBjorn Helgaas	  You should say N unless you know you need this.
265964a5fed6SBjorn Helgaas
26603a495511SWilliam Breathitt Grayconfig ISA_BUS
266117a2a129SWilliam Breathitt Gray	bool "ISA bus support on modern systems" if EXPERT
26623a495511SWilliam Breathitt Gray	help
266317a2a129SWilliam Breathitt Gray	  Expose ISA bus device drivers and options available for selection and
266417a2a129SWilliam Breathitt Gray	  configuration. Enable this option if your target machine has an ISA
266517a2a129SWilliam Breathitt Gray	  bus. ISA is an older system, displaced by PCI and newer bus
266617a2a129SWilliam Breathitt Gray	  architectures -- if your target machine is modern, it probably does
266717a2a129SWilliam Breathitt Gray	  not have an ISA bus.
26683a495511SWilliam Breathitt Gray
26693a495511SWilliam Breathitt Gray	  If unsure, say N.
26703a495511SWilliam Breathitt Gray
26711c00f016SDavid Rientjes# x86_64 have no ISA slots, but can have ISA-style DMA.
2672e279b6c1SSam Ravnborgconfig ISA_DMA_API
26731c00f016SDavid Rientjes	bool "ISA-style DMA support" if (X86_64 && EXPERT)
26741c00f016SDavid Rientjes	default y
26751c00f016SDavid Rientjes	help
26761c00f016SDavid Rientjes	  Enables ISA-style DMA support for devices requiring such controllers.
26771c00f016SDavid Rientjes	  If unsure, say Y.
2678e279b6c1SSam Ravnborg
267951e68d05SLinus Torvaldsif X86_32
268051e68d05SLinus Torvalds
2681e279b6c1SSam Ravnborgconfig ISA
2682e279b6c1SSam Ravnborg	bool "ISA support"
26838f9ca475SIngo Molnar	---help---
2684e279b6c1SSam Ravnborg	  Find out whether you have ISA slots on your motherboard.  ISA is the
2685e279b6c1SSam Ravnborg	  name of a bus system, i.e. the way the CPU talks to the other stuff
2686e279b6c1SSam Ravnborg	  inside your box.  Other bus systems are PCI, EISA, MicroChannel
2687e279b6c1SSam Ravnborg	  (MCA) or VESA.  ISA is an older system, now being displaced by PCI;
2688e279b6c1SSam Ravnborg	  newer boards don't support it.  If you have ISA, say Y, otherwise N.
2689e279b6c1SSam Ravnborg
2690e279b6c1SSam Ravnborgconfig SCx200
2691e279b6c1SSam Ravnborg	tristate "NatSemi SCx200 support"
26928f9ca475SIngo Molnar	---help---
2693e279b6c1SSam Ravnborg	  This provides basic support for National Semiconductor's
2694e279b6c1SSam Ravnborg	  (now AMD's) Geode processors.  The driver probes for the
2695e279b6c1SSam Ravnborg	  PCI-IDs of several on-chip devices, so its a good dependency
2696e279b6c1SSam Ravnborg	  for other scx200_* drivers.
2697e279b6c1SSam Ravnborg
2698e279b6c1SSam Ravnborg	  If compiled as a module, the driver is named scx200.
2699e279b6c1SSam Ravnborg
2700e279b6c1SSam Ravnborgconfig SCx200HR_TIMER
2701e279b6c1SSam Ravnborg	tristate "NatSemi SCx200 27MHz High-Resolution Timer Support"
2702592913ecSJohn Stultz	depends on SCx200
2703e279b6c1SSam Ravnborg	default y
27048f9ca475SIngo Molnar	---help---
2705e279b6c1SSam Ravnborg	  This driver provides a clocksource built upon the on-chip
2706e279b6c1SSam Ravnborg	  27MHz high-resolution timer.  Its also a workaround for
2707e279b6c1SSam Ravnborg	  NSC Geode SC-1100's buggy TSC, which loses time when the
2708e279b6c1SSam Ravnborg	  processor goes idle (as is done by the scheduler).  The
2709e279b6c1SSam Ravnborg	  other workaround is idle=poll boot option.
2710e279b6c1SSam Ravnborg
27113ef0e1f8SAndres Salomonconfig OLPC
27123ef0e1f8SAndres Salomon	bool "One Laptop Per Child support"
271354008979SThomas Gleixner	depends on !X86_PAE
27143c554946SAndres Salomon	select GPIOLIB
2715dc3119e7SThomas Gleixner	select OF
271645bb1674SDaniel Drake	select OF_PROMTREE
2717b4e51854SGrant Likely	select IRQ_DOMAIN
27188f9ca475SIngo Molnar	---help---
27193ef0e1f8SAndres Salomon	  Add support for detecting the unique features of the OLPC
27203ef0e1f8SAndres Salomon	  XO hardware.
27213ef0e1f8SAndres Salomon
2722a3128588SDaniel Drakeconfig OLPC_XO1_PM
2723a3128588SDaniel Drake	bool "OLPC XO-1 Power Management"
2724fa112cf1SBorislav Petkov	depends on OLPC && MFD_CS5535=y && PM_SLEEP
2725bf1ebf00SDaniel Drake	---help---
272697c4cb71SDaniel Drake	  Add support for poweroff and suspend of the OLPC XO-1 laptop.
2727bf1ebf00SDaniel Drake
2728cfee9597SDaniel Drakeconfig OLPC_XO1_RTC
2729cfee9597SDaniel Drake	bool "OLPC XO-1 Real Time Clock"
2730cfee9597SDaniel Drake	depends on OLPC_XO1_PM && RTC_DRV_CMOS
2731cfee9597SDaniel Drake	---help---
2732cfee9597SDaniel Drake	  Add support for the XO-1 real time clock, which can be used as a
2733cfee9597SDaniel Drake	  programmable wakeup source.
2734cfee9597SDaniel Drake
27357feda8e9SDaniel Drakeconfig OLPC_XO1_SCI
27367feda8e9SDaniel Drake	bool "OLPC XO-1 SCI extras"
273792e830f2SArnd Bergmann	depends on OLPC && OLPC_XO1_PM && GPIO_CS5535=y
2738ed8e47feSRandy Dunlap	depends on INPUT=y
2739d8d01a63SDaniel Drake	select POWER_SUPPLY
27407feda8e9SDaniel Drake	---help---
27417feda8e9SDaniel Drake	  Add support for SCI-based features of the OLPC XO-1 laptop:
27427bc74b3dSDaniel Drake	   - EC-driven system wakeups
27437feda8e9SDaniel Drake	   - Power button
27447bc74b3dSDaniel Drake	   - Ebook switch
27452cf2baeaSDaniel Drake	   - Lid switch
2746e1040ac6SDaniel Drake	   - AC adapter status updates
2747e1040ac6SDaniel Drake	   - Battery status updates
27487feda8e9SDaniel Drake
2749a0f30f59SDaniel Drakeconfig OLPC_XO15_SCI
2750a0f30f59SDaniel Drake	bool "OLPC XO-1.5 SCI extras"
2751d8d01a63SDaniel Drake	depends on OLPC && ACPI
2752d8d01a63SDaniel Drake	select POWER_SUPPLY
2753a0f30f59SDaniel Drake	---help---
2754a0f30f59SDaniel Drake	  Add support for SCI-based features of the OLPC XO-1.5 laptop:
2755a0f30f59SDaniel Drake	   - EC-driven system wakeups
2756a0f30f59SDaniel Drake	   - AC adapter status updates
2757a0f30f59SDaniel Drake	   - Battery status updates
2758e279b6c1SSam Ravnborg
2759d4f3e350SEd Wildgooseconfig ALIX
2760d4f3e350SEd Wildgoose	bool "PCEngines ALIX System Support (LED setup)"
2761d4f3e350SEd Wildgoose	select GPIOLIB
2762d4f3e350SEd Wildgoose	---help---
2763d4f3e350SEd Wildgoose	  This option enables system support for the PCEngines ALIX.
2764d4f3e350SEd Wildgoose	  At present this just sets up LEDs for GPIO control on
2765d4f3e350SEd Wildgoose	  ALIX2/3/6 boards.  However, other system specific setup should
2766d4f3e350SEd Wildgoose	  get added here.
2767d4f3e350SEd Wildgoose
2768d4f3e350SEd Wildgoose	  Note: You must still enable the drivers for GPIO and LED support
2769d4f3e350SEd Wildgoose	  (GPIO_CS5535 & LEDS_GPIO) to actually use the LEDs
2770d4f3e350SEd Wildgoose
2771d4f3e350SEd Wildgoose	  Note: You have to set alix.force=1 for boards with Award BIOS.
2772d4f3e350SEd Wildgoose
2773da4e3302SPhilip Prindevilleconfig NET5501
2774da4e3302SPhilip Prindeville	bool "Soekris Engineering net5501 System Support (LEDS, GPIO, etc)"
2775da4e3302SPhilip Prindeville	select GPIOLIB
2776da4e3302SPhilip Prindeville	---help---
2777da4e3302SPhilip Prindeville	  This option enables system support for the Soekris Engineering net5501.
2778da4e3302SPhilip Prindeville
27793197059aSPhilip A. Prindevilleconfig GEOS
27803197059aSPhilip A. Prindeville	bool "Traverse Technologies GEOS System Support (LEDS, GPIO, etc)"
27813197059aSPhilip A. Prindeville	select GPIOLIB
27823197059aSPhilip A. Prindeville	depends on DMI
27833197059aSPhilip A. Prindeville	---help---
27843197059aSPhilip A. Prindeville	  This option enables system support for the Traverse Technologies GEOS.
27853197059aSPhilip A. Prindeville
27867d029125SVivien Didelotconfig TS5500
27877d029125SVivien Didelot	bool "Technologic Systems TS-5500 platform support"
27887d029125SVivien Didelot	depends on MELAN
27897d029125SVivien Didelot	select CHECK_SIGNATURE
27907d029125SVivien Didelot	select NEW_LEDS
27917d029125SVivien Didelot	select LEDS_CLASS
27927d029125SVivien Didelot	---help---
27937d029125SVivien Didelot	  This option enables system support for the Technologic Systems TS-5500.
27947d029125SVivien Didelot
2795e279b6c1SSam Ravnborgendif # X86_32
2796e279b6c1SSam Ravnborg
279723ac4ae8SAndreas Herrmannconfig AMD_NB
2798e279b6c1SSam Ravnborg	def_bool y
27990e152cd7SBorislav Petkov	depends on CPU_SUP_AMD && PCI
2800e279b6c1SSam Ravnborg
2801e3263ab3SDavid Herrmannconfig X86_SYSFB
2802e3263ab3SDavid Herrmann	bool "Mark VGA/VBE/EFI FB as generic system framebuffer"
2803e3263ab3SDavid Herrmann	help
2804e3263ab3SDavid Herrmann	  Firmwares often provide initial graphics framebuffers so the BIOS,
2805e3263ab3SDavid Herrmann	  bootloader or kernel can show basic video-output during boot for
2806e3263ab3SDavid Herrmann	  user-guidance and debugging. Historically, x86 used the VESA BIOS
2807e3263ab3SDavid Herrmann	  Extensions and EFI-framebuffers for this, which are mostly limited
2808e3263ab3SDavid Herrmann	  to x86.
2809e3263ab3SDavid Herrmann	  This option, if enabled, marks VGA/VBE/EFI framebuffers as generic
2810e3263ab3SDavid Herrmann	  framebuffers so the new generic system-framebuffer drivers can be
2811e3263ab3SDavid Herrmann	  used on x86. If the framebuffer is not compatible with the generic
2812e3a5dc08SNikolas Nyby	  modes, it is advertised as fallback platform framebuffer so legacy
2813e3263ab3SDavid Herrmann	  drivers like efifb, vesafb and uvesafb can pick it up.
2814e3263ab3SDavid Herrmann	  If this option is not selected, all system framebuffers are always
2815e3263ab3SDavid Herrmann	  marked as fallback platform framebuffers as usual.
2816e3263ab3SDavid Herrmann
2817e3263ab3SDavid Herrmann	  Note: Legacy fbdev drivers, including vesafb, efifb, uvesafb, will
2818e3263ab3SDavid Herrmann	  not be able to pick up generic system framebuffers if this option
2819e3263ab3SDavid Herrmann	  is selected. You are highly encouraged to enable simplefb as
2820e3263ab3SDavid Herrmann	  replacement if you select this option. simplefb can correctly deal
2821e3263ab3SDavid Herrmann	  with generic system framebuffers. But you should still keep vesafb
2822e3263ab3SDavid Herrmann	  and others enabled as fallback if a system framebuffer is
2823e3263ab3SDavid Herrmann	  incompatible with simplefb.
2824e3263ab3SDavid Herrmann
2825e3263ab3SDavid Herrmann	  If unsure, say Y.
2826e3263ab3SDavid Herrmann
2827e279b6c1SSam Ravnborgendmenu
2828e279b6c1SSam Ravnborg
2829e279b6c1SSam Ravnborg
28301572497cSChristoph Hellwigmenu "Binary Emulations"
2831e279b6c1SSam Ravnborg
2832e279b6c1SSam Ravnborgconfig IA32_EMULATION
2833e279b6c1SSam Ravnborg	bool "IA32 Emulation"
2834e279b6c1SSam Ravnborg	depends on X86_64
283539f88911SIngo Molnar	select ARCH_WANT_OLD_COMPAT_IPC
2836d1603990SRandy Dunlap	select BINFMT_ELF
2837a97f52e6SRoland McGrath	select COMPAT_BINFMT_ELF
283839f88911SIngo Molnar	select COMPAT_OLD_SIGACTION
28398f9ca475SIngo Molnar	---help---
28405fd92e65SH. J. Lu	  Include code to run legacy 32-bit programs under a
28415fd92e65SH. J. Lu	  64-bit kernel. You should likely turn this on, unless you're
28425fd92e65SH. J. Lu	  100% sure that you don't have any 32-bit programs left.
2843e279b6c1SSam Ravnborg
2844e279b6c1SSam Ravnborgconfig IA32_AOUT
2845e279b6c1SSam Ravnborg	tristate "IA32 a.out support"
28466b213e1bSDavid Woodhouse	depends on IA32_EMULATION
28478f9ca475SIngo Molnar	---help---
2848e279b6c1SSam Ravnborg	  Support old a.out binaries in the 32bit emulation.
2849e279b6c1SSam Ravnborg
28500bf62763SH. Peter Anvinconfig X86_X32
28516ea30386SKees Cook	bool "x32 ABI for 64-bit mode"
28529b54050bSBrian Gerst	depends on X86_64
28535fd92e65SH. J. Lu	---help---
28545fd92e65SH. J. Lu	  Include code to run binaries for the x32 native 32-bit ABI
28555fd92e65SH. J. Lu	  for 64-bit processors.  An x32 process gets access to the
28565fd92e65SH. J. Lu	  full 64-bit register file and wide data path while leaving
28575fd92e65SH. J. Lu	  pointers at 32 bits for smaller memory footprint.
28585fd92e65SH. J. Lu
28595fd92e65SH. J. Lu	  You will need a recent binutils (2.22 or later) with
28605fd92e65SH. J. Lu	  elf32_x86_64 support enabled to compile a kernel with this
28615fd92e65SH. J. Lu	  option set.
28625fd92e65SH. J. Lu
2863953fee1dSIngo Molnarconfig COMPAT_32
2864953fee1dSIngo Molnar	def_bool y
2865953fee1dSIngo Molnar	depends on IA32_EMULATION || X86_32
2866953fee1dSIngo Molnar	select HAVE_UID16
2867953fee1dSIngo Molnar	select OLD_SIGSUSPEND3
2868953fee1dSIngo Molnar
2869e279b6c1SSam Ravnborgconfig COMPAT
28703c2362e6SHarvey Harrison	def_bool y
28710bf62763SH. Peter Anvin	depends on IA32_EMULATION || X86_X32
2872e279b6c1SSam Ravnborg
28733120e25eSJan Beulichif COMPAT
2874e279b6c1SSam Ravnborgconfig COMPAT_FOR_U64_ALIGNMENT
28753120e25eSJan Beulich	def_bool y
2876e279b6c1SSam Ravnborg
2877e279b6c1SSam Ravnborgconfig SYSVIPC_COMPAT
28783c2362e6SHarvey Harrison	def_bool y
28793120e25eSJan Beulich	depends on SYSVIPC
28803120e25eSJan Beulichendif
2881ee009e4aSDavid Howells
2882e279b6c1SSam Ravnborgendmenu
2883e279b6c1SSam Ravnborg
2884e279b6c1SSam Ravnborg
2885e5beae16SKeith Packardconfig HAVE_ATOMIC_IOMAP
2886e5beae16SKeith Packard	def_bool y
2887e5beae16SKeith Packard	depends on X86_32
2888e5beae16SKeith Packard
28894692d77fSAlessandro Rubiniconfig X86_DEV_DMA_OPS
28904692d77fSAlessandro Rubini	bool
289183125a3aSAlessandro Rubini	depends on X86_64 || STA2X11
28924692d77fSAlessandro Rubini
2893f7219a53SAlessandro Rubiniconfig X86_DMA_REMAP
2894f7219a53SAlessandro Rubini	bool
289583125a3aSAlessandro Rubini	depends on STA2X11
2896f7219a53SAlessandro Rubini
2897e585513bSKirill A. Shutemovconfig HAVE_GENERIC_GUP
2898e585513bSKirill A. Shutemov	def_bool y
2899e585513bSKirill A. Shutemov
2900e279b6c1SSam Ravnborgsource "drivers/firmware/Kconfig"
2901e279b6c1SSam Ravnborg
2902edf88417SAvi Kivitysource "arch/x86/kvm/Kconfig"
2903