xref: /linux/arch/x86/Kconfig (revision 9087c37584fb7d8315877bb55f85e4268cc0b4f4)
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
17117ed454SThomas Gleixner	select HAVE_DEBUG_STACKOVERFLOW
18341c787eSIngo Molnar	select MODULES_USE_ELF_REL
19341c787eSIngo Molnar	select OLD_SIGACTION
207ac87074SVincenzo Frascino	select GENERIC_VDSO_32
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:
264eb0716eSAlexandre Ghiti	select ARCH_HAS_GIGANTIC_PAGE
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
33f8781c4aSDominik Brodowski	select ARCH_HAS_SYSCALL_WRAPPER
341032c0baSSam Ravnborg
35518049d9SSteven Rostedt (VMware)config FORCE_DYNAMIC_FTRACE
36518049d9SSteven Rostedt (VMware)	def_bool y
37518049d9SSteven Rostedt (VMware)	depends on X86_32
38518049d9SSteven Rostedt (VMware)	depends on FUNCTION_TRACER
39518049d9SSteven Rostedt (VMware)	select DYNAMIC_FTRACE
40518049d9SSteven Rostedt (VMware)	help
41518049d9SSteven Rostedt (VMware)	 We keep the static function tracing (!DYNAMIC_FTRACE) around
42518049d9SSteven Rostedt (VMware)	 in order to test the non static function tracing in the
43518049d9SSteven Rostedt (VMware)	 generic code, as other architectures still use it. But we
44518049d9SSteven Rostedt (VMware)	 only need to keep it around for x86_64. No need to keep it
45518049d9SSteven Rostedt (VMware)	 for x86_32. For x86_32, force DYNAMIC_FTRACE.
46d94e0685SIngo Molnar#
47d94e0685SIngo Molnar# Arch settings
48d94e0685SIngo Molnar#
49d94e0685SIngo Molnar# ( Note that options that are marked 'if X86_64' could in principle be
50d94e0685SIngo Molnar#   ported to 32-bit as well. )
51d94e0685SIngo Molnar#
528d5fffb9SSam Ravnborgconfig X86
533c2362e6SHarvey Harrison	def_bool y
54c763ea26SIngo Molnar	#
55c763ea26SIngo Molnar	# Note: keep this list sorted alphabetically
56c763ea26SIngo Molnar	#
576471b825SIngo Molnar	select ACPI_LEGACY_TABLES_LOOKUP	if ACPI
586e0a0ea1SGraeme Gregory	select ACPI_SYSTEM_POWER_STATES_SUPPORT	if ACPI
59942fa985SYury Norov	select ARCH_32BIT_OFF_T			if X86_32
606471b825SIngo Molnar	select ARCH_CLOCKSOURCE_DATA
612a21ad57SThomas Gleixner	select ARCH_CLOCKSOURCE_INIT
6291dda51aSAleksey Makarov	select ARCH_HAS_ACPI_TABLE_UPGRADE	if ACPI
63fa5b6ec9SLaura Abbott	select ARCH_HAS_DEBUG_VIRTUAL
6421266be9SDan Williams	select ARCH_HAS_DEVMEM_IS_ALLOWED
656471b825SIngo Molnar	select ARCH_HAS_ELF_RANDOMIZE
6672d93104SLinus Torvalds	select ARCH_HAS_FAST_MULTIPLIER
67316d097cSDave Hansen	select ARCH_HAS_FILTER_PGPROT
686974f0c4SDaniel Micay	select ARCH_HAS_FORTIFY_SOURCE
69957e3facSRiku Voipio	select ARCH_HAS_GCOV_PROFILE_ALL
705c9a8750SDmitry Vyukov	select ARCH_HAS_KCOV			if X86_64
7110bcc80eSMathieu Desnoyers	select ARCH_HAS_MEMBARRIER_SYNC_CORE
72c763ea26SIngo Molnar	select ARCH_HAS_PMEM_API		if X86_64
733010a5eaSLaurent Dufour	select ARCH_HAS_PTE_SPECIAL
7439208aa7SKees Cook	select ARCH_HAS_REFCOUNT
750aed55afSDan Williams	select ARCH_HAS_UACCESS_FLUSHCACHE	if X86_64
76092b31aaSDan Williams	select ARCH_HAS_UACCESS_MCSAFE		if X86_64 && X86_MCE
77d2852a22SDaniel Borkmann	select ARCH_HAS_SET_MEMORY
78d253ca0cSRick Edgecombe	select ARCH_HAS_SET_DIRECT_MAP
79ad21fc4fSLaura Abbott	select ARCH_HAS_STRICT_KERNEL_RWX
80ad21fc4fSLaura Abbott	select ARCH_HAS_STRICT_MODULE_RWX
81ac1ab12aSMathieu Desnoyers	select ARCH_HAS_SYNC_CORE_BEFORE_USERMODE
82c6d30853SAndrey Ryabinin	select ARCH_HAS_UBSAN_SANITIZE_ALL
8365f7d049SOliver O'Halloran	select ARCH_HAS_ZONE_DEVICE		if X86_64
846471b825SIngo Molnar	select ARCH_HAVE_NMI_SAFE_CMPXCHG
856471b825SIngo Molnar	select ARCH_MIGHT_HAVE_ACPI_PDC		if ACPI
8677fbbc81SMark Salter	select ARCH_MIGHT_HAVE_PC_PARPORT
875e2c18c0SMark Salter	select ARCH_MIGHT_HAVE_PC_SERIO
883599fe12SThomas Gleixner	select ARCH_STACKWALK
892c870e61SArnd Bergmann	select ARCH_SUPPORTS_ACPI
906471b825SIngo Molnar	select ARCH_SUPPORTS_ATOMIC_RMW
916471b825SIngo Molnar	select ARCH_SUPPORTS_NUMA_BALANCING	if X86_64
926471b825SIngo Molnar	select ARCH_USE_BUILTIN_BSWAP
936471b825SIngo Molnar	select ARCH_USE_QUEUED_RWLOCKS
946471b825SIngo Molnar	select ARCH_USE_QUEUED_SPINLOCKS
95ce4a4e56SAndy Lutomirski	select ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH
96c763ea26SIngo Molnar	select ARCH_WANTS_DYNAMIC_TASK_STRUCT
9738d8b4e6SHuang Ying	select ARCH_WANTS_THP_SWAP		if X86_64
986471b825SIngo Molnar	select BUILDTIME_EXTABLE_SORT
996471b825SIngo Molnar	select CLKEVT_I8253
1006471b825SIngo Molnar	select CLOCKSOURCE_VALIDATE_LAST_CYCLE
1016471b825SIngo Molnar	select CLOCKSOURCE_WATCHDOG
1026471b825SIngo Molnar	select DCACHE_WORD_ACCESS
10345471cd9SLinus Torvalds	select EDAC_ATOMIC_SCRUB
10445471cd9SLinus Torvalds	select EDAC_SUPPORT
1056471b825SIngo Molnar	select GENERIC_CLOCKEVENTS
1066471b825SIngo Molnar	select GENERIC_CLOCKEVENTS_BROADCAST	if X86_64 || (X86_32 && X86_LOCAL_APIC)
1076471b825SIngo Molnar	select GENERIC_CLOCKEVENTS_MIN_ADJUST
1086471b825SIngo Molnar	select GENERIC_CMOS_UPDATE
1096471b825SIngo Molnar	select GENERIC_CPU_AUTOPROBE
11061dc0f55SThomas Gleixner	select GENERIC_CPU_VULNERABILITIES
1116471b825SIngo Molnar	select GENERIC_EARLY_IOREMAP
1126471b825SIngo Molnar	select GENERIC_FIND_FIRST_BIT
1136471b825SIngo Molnar	select GENERIC_IOMAP
114c7d6c9ddSThomas Gleixner	select GENERIC_IRQ_EFFECTIVE_AFF_MASK	if SMP
1150fa115daSThomas Gleixner	select GENERIC_IRQ_MATRIX_ALLOCATOR	if X86_LOCAL_APIC
116ad7a929fSThomas Gleixner	select GENERIC_IRQ_MIGRATION		if SMP
1176471b825SIngo Molnar	select GENERIC_IRQ_PROBE
118c201c917SThomas Gleixner	select GENERIC_IRQ_RESERVATION_MODE
1196471b825SIngo Molnar	select GENERIC_IRQ_SHOW
1206471b825SIngo Molnar	select GENERIC_PENDING_IRQ		if SMP
1216471b825SIngo Molnar	select GENERIC_SMP_IDLE_THREAD
1226471b825SIngo Molnar	select GENERIC_STRNCPY_FROM_USER
1236471b825SIngo Molnar	select GENERIC_STRNLEN_USER
1246471b825SIngo Molnar	select GENERIC_TIME_VSYSCALL
1257ac87074SVincenzo Frascino	select GENERIC_GETTIMEOFDAY
12639656e83SChristoph Hellwig	select GUP_GET_PTE_LOW_HIGH		if X86_PAE
1277edaeb68SThomas Gleixner	select HARDLOCKUP_CHECK_TIMESTAMP	if X86_64
1286471b825SIngo Molnar	select HAVE_ACPI_APEI			if ACPI
1296471b825SIngo Molnar	select HAVE_ACPI_APEI_NMI		if ACPI
1306471b825SIngo Molnar	select HAVE_ALIGNED_STRUCT_PAGE		if SLUB
1316471b825SIngo Molnar	select HAVE_ARCH_AUDITSYSCALL
1326471b825SIngo Molnar	select HAVE_ARCH_HUGE_VMAP		if X86_64 || X86_PAE
1336471b825SIngo Molnar	select HAVE_ARCH_JUMP_LABEL
134b34006c4SArd Biesheuvel	select HAVE_ARCH_JUMP_LABEL_RELATIVE
135d17a1d97SAndrey Ryabinin	select HAVE_ARCH_KASAN			if X86_64
1366471b825SIngo Molnar	select HAVE_ARCH_KGDB
1379e08f57dSDaniel Cashman	select HAVE_ARCH_MMAP_RND_BITS		if MMU
1389e08f57dSDaniel Cashman	select HAVE_ARCH_MMAP_RND_COMPAT_BITS	if MMU && COMPAT
1391b028f78SDmitry Safonov	select HAVE_ARCH_COMPAT_MMAP_BASES	if MMU && COMPAT
140271ca788SArd Biesheuvel	select HAVE_ARCH_PREL32_RELOCATIONS
1416471b825SIngo Molnar	select HAVE_ARCH_SECCOMP_FILTER
142f7d83c1cSKees Cook	select HAVE_ARCH_THREAD_STRUCT_WHITELIST
143afaef01cSAlexander Popov	select HAVE_ARCH_STACKLEAK
1446471b825SIngo Molnar	select HAVE_ARCH_TRACEHOOK
1456471b825SIngo Molnar	select HAVE_ARCH_TRANSPARENT_HUGEPAGE
146a00cc7d9SMatthew Wilcox	select HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD if X86_64
147e37e43a4SAndy Lutomirski	select HAVE_ARCH_VMAP_STACK		if X86_64
148c763ea26SIngo Molnar	select HAVE_ARCH_WITHIN_STACK_FRAMES
1496471b825SIngo Molnar	select HAVE_CMPXCHG_DOUBLE
1506471b825SIngo Molnar	select HAVE_CMPXCHG_LOCAL
1516471b825SIngo Molnar	select HAVE_CONTEXT_TRACKING		if X86_64
152c1bd55f9SJosh Triplett	select HAVE_COPY_THREAD_TLS
1536471b825SIngo Molnar	select HAVE_C_RECORDMCOUNT
1546471b825SIngo Molnar	select HAVE_DEBUG_KMEMLEAK
1559c5a3621SAkinobu Mita	select HAVE_DMA_CONTIGUOUS
156677aa9f7SSteven Rostedt	select HAVE_DYNAMIC_FTRACE
15706aeaaeaSMasami Hiramatsu	select HAVE_DYNAMIC_FTRACE_WITH_REGS
15803f5781bSWang YanQing	select HAVE_EBPF_JIT
15958340a07SJohannes Berg	select HAVE_EFFICIENT_UNALIGNED_ACCESS
1606630a8e5SChristoph Hellwig	select HAVE_EISA
1615f56a5dfSJiri Slaby	select HAVE_EXIT_THREAD
16267a929e0SChristoph Hellwig	select HAVE_FAST_GUP
163644e0e8dSSteven Rostedt (VMware)	select HAVE_FENTRY			if X86_64 || DYNAMIC_FTRACE
1646471b825SIngo Molnar	select HAVE_FTRACE_MCOUNT_RECORD
1656471b825SIngo Molnar	select HAVE_FUNCTION_GRAPH_TRACER
1666471b825SIngo Molnar	select HAVE_FUNCTION_TRACER
1676b90bd4bSEmese Revfy	select HAVE_GCC_PLUGINS
1680067f129SK.Prasad	select HAVE_HW_BREAKPOINT
1696471b825SIngo Molnar	select HAVE_IDE
1706471b825SIngo Molnar	select HAVE_IOREMAP_PROT
1716471b825SIngo Molnar	select HAVE_IRQ_EXIT_ON_IRQ_STACK	if X86_64
1726471b825SIngo Molnar	select HAVE_IRQ_TIME_ACCOUNTING
1736471b825SIngo Molnar	select HAVE_KERNEL_BZIP2
1746471b825SIngo Molnar	select HAVE_KERNEL_GZIP
1756471b825SIngo Molnar	select HAVE_KERNEL_LZ4
1766471b825SIngo Molnar	select HAVE_KERNEL_LZMA
1776471b825SIngo Molnar	select HAVE_KERNEL_LZO
1786471b825SIngo Molnar	select HAVE_KERNEL_XZ
1796471b825SIngo Molnar	select HAVE_KPROBES
1806471b825SIngo Molnar	select HAVE_KPROBES_ON_FTRACE
181540adea3SMasami Hiramatsu	select HAVE_FUNCTION_ERROR_INJECTION
1826471b825SIngo Molnar	select HAVE_KRETPROBES
1836471b825SIngo Molnar	select HAVE_KVM
1846471b825SIngo Molnar	select HAVE_LIVEPATCH			if X86_64
1856471b825SIngo Molnar	select HAVE_MEMBLOCK_NODE_MAP
1860102752eSFrederic Weisbecker	select HAVE_MIXED_BREAKPOINTS_REGS
187ee9f8fceSJosh Poimboeuf	select HAVE_MOD_ARCH_SPECIFIC
1889f132f7eSJoel Fernandes (Google)	select HAVE_MOVE_PMD
18942a0bb3fSPetr Mladek	select HAVE_NMI
1906471b825SIngo Molnar	select HAVE_OPROFILE
1916471b825SIngo Molnar	select HAVE_OPTPROBES
1926471b825SIngo Molnar	select HAVE_PCSPKR_PLATFORM
1936471b825SIngo Molnar	select HAVE_PERF_EVENTS
194c01d4323SFrederic Weisbecker	select HAVE_PERF_EVENTS_NMI
19592e5aae4SNicholas Piggin	select HAVE_HARDLOCKUP_DETECTOR_PERF	if PERF_EVENTS && HAVE_PERF_EVENTS_NMI
196eb01d42aSChristoph Hellwig	select HAVE_PCI
197c5e63197SJiri Olsa	select HAVE_PERF_REGS
198c5ebcedbSJiri Olsa	select HAVE_PERF_USER_STACK_DUMP
19948a8b97cSPeter Zijlstra	select HAVE_RCU_TABLE_FREE		if PARAVIRT
2006471b825SIngo Molnar	select HAVE_REGS_AND_STACK_ACCESS_API
2016415b38bSJiri Slaby	select HAVE_RELIABLE_STACKTRACE		if X86_64 && (UNWINDER_FRAME_POINTER || UNWINDER_ORC) && STACK_VALIDATION
2023c88ee19SMasami Hiramatsu	select HAVE_FUNCTION_ARG_ACCESS_API
203d148eac0SMasahiro Yamada	select HAVE_STACKPROTECTOR		if CC_HAS_SANE_STACKPROTECTOR
204c763ea26SIngo Molnar	select HAVE_STACK_VALIDATION		if X86_64
205d6761b8fSMathieu Desnoyers	select HAVE_RSEQ
2066471b825SIngo Molnar	select HAVE_SYSCALL_TRACEPOINTS
2076471b825SIngo Molnar	select HAVE_UNSTABLE_SCHED_CLOCK
2087c68af6eSAvi Kivity	select HAVE_USER_RETURN_NOTIFIER
2097ac87074SVincenzo Frascino	select HAVE_GENERIC_VDSO
21005736e4aSThomas Gleixner	select HOTPLUG_SMT			if SMP
211c0185808SThomas Gleixner	select IRQ_FORCED_THREADING
21286596f0aSChristoph Hellwig	select NEED_SG_DMA_LENGTH
2132eac9c2dSChristoph Hellwig	select PCI_DOMAINS			if PCI
214625210cfSSinan Kaya	select PCI_LOCKLESS_CONFIG		if PCI
2156471b825SIngo Molnar	select PERF_EVENTS
2163195ef59SPrarit Bhargava	select RTC_LIB
217d6faca40SArnd Bergmann	select RTC_MC146818_LIB
2186471b825SIngo Molnar	select SPARSE_IRQ
21983fe27eaSPranith Kumar	select SRCU
2206471b825SIngo Molnar	select SYSCTL_EXCEPTION_TRACE
22115f4eae7SAndy Lutomirski	select THREAD_INFO_IN_TASK
2226471b825SIngo Molnar	select USER_STACKTRACE_SUPPORT
2236471b825SIngo Molnar	select VIRT_TO_BUS
2246471b825SIngo Molnar	select X86_FEATURE_NAMES		if PROC_FS
2250c608dadSAubrey Li	select PROC_PID_ARCH_STATUS		if PROC_FS
2267d8330a5SBalbir Singh
227ba7e4d13SIngo Molnarconfig INSTRUCTION_DECODER
2283120e25eSJan Beulich	def_bool y
2293120e25eSJan Beulich	depends on KPROBES || PERF_EVENTS || UPROBES
230ba7e4d13SIngo Molnar
23151b26adaSLinus Torvaldsconfig OUTPUT_FORMAT
23251b26adaSLinus Torvalds	string
23351b26adaSLinus Torvalds	default "elf32-i386" if X86_32
23451b26adaSLinus Torvalds	default "elf64-x86-64" if X86_64
23551b26adaSLinus Torvalds
23673531905SSam Ravnborgconfig ARCH_DEFCONFIG
237b9b39bfbSSam Ravnborg	string
23873531905SSam Ravnborg	default "arch/x86/configs/i386_defconfig" if X86_32
23973531905SSam Ravnborg	default "arch/x86/configs/x86_64_defconfig" if X86_64
240b9b39bfbSSam Ravnborg
2418d5fffb9SSam Ravnborgconfig LOCKDEP_SUPPORT
2423c2362e6SHarvey Harrison	def_bool y
2438d5fffb9SSam Ravnborg
2448d5fffb9SSam Ravnborgconfig STACKTRACE_SUPPORT
2453c2362e6SHarvey Harrison	def_bool y
2468d5fffb9SSam Ravnborg
2478d5fffb9SSam Ravnborgconfig MMU
2483c2362e6SHarvey Harrison	def_bool y
2498d5fffb9SSam Ravnborg
2509e08f57dSDaniel Cashmanconfig ARCH_MMAP_RND_BITS_MIN
2519e08f57dSDaniel Cashman	default 28 if 64BIT
2529e08f57dSDaniel Cashman	default 8
2539e08f57dSDaniel Cashman
2549e08f57dSDaniel Cashmanconfig ARCH_MMAP_RND_BITS_MAX
2559e08f57dSDaniel Cashman	default 32 if 64BIT
2569e08f57dSDaniel Cashman	default 16
2579e08f57dSDaniel Cashman
2589e08f57dSDaniel Cashmanconfig ARCH_MMAP_RND_COMPAT_BITS_MIN
2599e08f57dSDaniel Cashman	default 8
2609e08f57dSDaniel Cashman
2619e08f57dSDaniel Cashmanconfig ARCH_MMAP_RND_COMPAT_BITS_MAX
2629e08f57dSDaniel Cashman	default 16
2639e08f57dSDaniel Cashman
2648d5fffb9SSam Ravnborgconfig SBUS
2658d5fffb9SSam Ravnborg	bool
2668d5fffb9SSam Ravnborg
2678d5fffb9SSam Ravnborgconfig GENERIC_ISA_DMA
2683120e25eSJan Beulich	def_bool y
2693120e25eSJan Beulich	depends on ISA_DMA_API
2708d5fffb9SSam Ravnborg
2718d5fffb9SSam Ravnborgconfig GENERIC_BUG
2723c2362e6SHarvey Harrison	def_bool y
2738d5fffb9SSam Ravnborg	depends on BUG
274b93a531eSJan Beulich	select GENERIC_BUG_RELATIVE_POINTERS if X86_64
275b93a531eSJan Beulich
276b93a531eSJan Beulichconfig GENERIC_BUG_RELATIVE_POINTERS
277b93a531eSJan Beulich	bool
2788d5fffb9SSam Ravnborg
2798d5fffb9SSam Ravnborgconfig ARCH_MAY_HAVE_PC_FDC
2803120e25eSJan Beulich	def_bool y
2813120e25eSJan Beulich	depends on ISA_DMA_API
2828d5fffb9SSam Ravnborg
2831032c0baSSam Ravnborgconfig GENERIC_CALIBRATE_DELAY
2841032c0baSSam Ravnborg	def_bool y
2851032c0baSSam Ravnborg
2869a0b8415Svenkatesh.pallipadi@intel.comconfig ARCH_HAS_CPU_RELAX
2879a0b8415Svenkatesh.pallipadi@intel.com	def_bool y
2888d5fffb9SSam Ravnborg
2891b27d05bSPekka Enbergconfig ARCH_HAS_CACHE_LINE_SIZE
2901b27d05bSPekka Enberg	def_bool y
2911b27d05bSPekka Enberg
292316d097cSDave Hansenconfig ARCH_HAS_FILTER_PGPROT
293316d097cSDave Hansen	def_bool y
294316d097cSDave Hansen
295dd5af90aSMike Travisconfig HAVE_SETUP_PER_CPU_AREA
29689c9c4c5SBrian Gerst	def_bool y
297b32ef636Stravis@sgi.com
29808fc4580STejun Heoconfig NEED_PER_CPU_EMBED_FIRST_CHUNK
29908fc4580STejun Heo	def_bool y
30008fc4580STejun Heo
30108fc4580STejun Heoconfig NEED_PER_CPU_PAGE_FIRST_CHUNK
30211124411STejun Heo	def_bool y
30311124411STejun Heo
304801e4062SJohannes Bergconfig ARCH_HIBERNATION_POSSIBLE
305801e4062SJohannes Berg	def_bool y
306801e4062SJohannes Berg
307f4cb5700SJohannes Bergconfig ARCH_SUSPEND_POSSIBLE
308f4cb5700SJohannes Berg	def_bool y
309f4cb5700SJohannes Berg
310cfe28c5dSSteve Capperconfig ARCH_WANT_HUGE_PMD_SHARE
311cfe28c5dSSteve Capper	def_bool y
312cfe28c5dSSteve Capper
31353313b2cSSteve Capperconfig ARCH_WANT_GENERAL_HUGETLB
31453313b2cSSteve Capper	def_bool y
31553313b2cSSteve Capper
3168d5fffb9SSam Ravnborgconfig ZONE_DMA32
317e0fd24a3SJan Beulich	def_bool y if X86_64
3188d5fffb9SSam Ravnborg
3198d5fffb9SSam Ravnborgconfig AUDIT_ARCH
320e0fd24a3SJan Beulich	def_bool y if X86_64
3218d5fffb9SSam Ravnborg
3226a11f75bSAkinobu Mitaconfig ARCH_SUPPORTS_DEBUG_PAGEALLOC
3236a11f75bSAkinobu Mita	def_bool y
3246a11f75bSAkinobu Mita
325d6f2d75aSAndrey Ryabininconfig KASAN_SHADOW_OFFSET
326d6f2d75aSAndrey Ryabinin	hex
327d6f2d75aSAndrey Ryabinin	depends on KASAN
328d6f2d75aSAndrey Ryabinin	default 0xdffffc0000000000
329d6f2d75aSAndrey Ryabinin
33069575d38SShane Wangconfig HAVE_INTEL_TXT
33169575d38SShane Wang	def_bool y
3326ea30386SKees Cook	depends on INTEL_IOMMU && ACPI
33369575d38SShane Wang
3346b0c3d44SSam Ravnborgconfig X86_32_SMP
3356b0c3d44SSam Ravnborg	def_bool y
3366b0c3d44SSam Ravnborg	depends on X86_32 && SMP
3376b0c3d44SSam Ravnborg
3386b0c3d44SSam Ravnborgconfig X86_64_SMP
3396b0c3d44SSam Ravnborg	def_bool y
3406b0c3d44SSam Ravnborg	depends on X86_64 && SMP
3416b0c3d44SSam Ravnborg
342ccbeed3aSTejun Heoconfig X86_32_LAZY_GS
343ccbeed3aSTejun Heo	def_bool y
3448458f8c2SMasahiro Yamada	depends on X86_32 && !STACKPROTECTOR
345ccbeed3aSTejun Heo
3462b144498SSrikar Dronamrajuconfig ARCH_SUPPORTS_UPROBES
3472b144498SSrikar Dronamraju	def_bool y
3482b144498SSrikar Dronamraju
349d20642f0SRob Herringconfig FIX_EARLYCON_MEM
350d20642f0SRob Herring	def_bool y
351d20642f0SRob Herring
35294d49eb3SKirill A. Shutemovconfig DYNAMIC_PHYSICAL_MASK
35394d49eb3SKirill A. Shutemov	bool
35494d49eb3SKirill A. Shutemov
35598233368SKirill A. Shutemovconfig PGTABLE_LEVELS
35698233368SKirill A. Shutemov	int
35777ef56e4SKirill A. Shutemov	default 5 if X86_5LEVEL
35898233368SKirill A. Shutemov	default 4 if X86_64
35998233368SKirill A. Shutemov	default 3 if X86_PAE
36098233368SKirill A. Shutemov	default 2
36198233368SKirill A. Shutemov
3622a61f474SMasahiro Yamadaconfig CC_HAS_SANE_STACKPROTECTOR
3632a61f474SMasahiro Yamada	bool
3642a61f474SMasahiro Yamada	default $(success,$(srctree)/scripts/gcc-x86_64-has-stack-protector.sh $(CC)) if 64BIT
3652a61f474SMasahiro Yamada	default $(success,$(srctree)/scripts/gcc-x86_32-has-stack-protector.sh $(CC))
3662a61f474SMasahiro Yamada	help
3672a61f474SMasahiro Yamada	   We have to make sure stack protector is unconditionally disabled if
3682a61f474SMasahiro Yamada	   the compiler produces broken code.
3692a61f474SMasahiro Yamada
370506f1d07SSam Ravnborgmenu "Processor type and features"
371506f1d07SSam Ravnborg
3725ee71535SRandy Dunlapconfig ZONE_DMA
3735ee71535SRandy Dunlap	bool "DMA memory allocation support" if EXPERT
3745ee71535SRandy Dunlap	default y
3755ee71535SRandy Dunlap	help
3765ee71535SRandy Dunlap	  DMA memory allocation support allows devices with less than 32-bit
3775ee71535SRandy Dunlap	  addressing to allocate within the first 16MB of address space.
3785ee71535SRandy Dunlap	  Disable if no such devices will be used.
3795ee71535SRandy Dunlap
3805ee71535SRandy Dunlap	  If unsure, say Y.
3815ee71535SRandy Dunlap
382506f1d07SSam Ravnborgconfig SMP
383506f1d07SSam Ravnborg	bool "Symmetric multi-processing support"
384506f1d07SSam Ravnborg	---help---
385506f1d07SSam Ravnborg	  This enables support for systems with more than one CPU. If you have
3864a474157SRobert Graffham	  a system with only one CPU, say N. If you have a system with more
3874a474157SRobert Graffham	  than one CPU, say Y.
388506f1d07SSam Ravnborg
3894a474157SRobert Graffham	  If you say N here, the kernel will run on uni- and multiprocessor
390506f1d07SSam Ravnborg	  machines, but will use only one CPU of a multiprocessor machine. If
391506f1d07SSam Ravnborg	  you say Y here, the kernel will run on many, but not all,
3924a474157SRobert Graffham	  uniprocessor machines. On a uniprocessor machine, the kernel
393506f1d07SSam Ravnborg	  will run faster if you say N here.
394506f1d07SSam Ravnborg
395506f1d07SSam Ravnborg	  Note that if you say Y here and choose architecture "586" or
396506f1d07SSam Ravnborg	  "Pentium" under "Processor family", the kernel will not work on 486
397506f1d07SSam Ravnborg	  architectures. Similarly, multiprocessor kernels for the "PPro"
398506f1d07SSam Ravnborg	  architecture may not work on all Pentium based boards.
399506f1d07SSam Ravnborg
400506f1d07SSam Ravnborg	  People using multiprocessor machines who say Y here should also say
401506f1d07SSam Ravnborg	  Y to "Enhanced Real Time Clock Support", below. The "Advanced Power
402506f1d07SSam Ravnborg	  Management" code will be disabled if you say Y here.
403506f1d07SSam Ravnborg
404cb1aaebeSMauro Carvalho Chehab	  See also <file:Documentation/x86/i386/IO-APIC.rst>,
405c9525a3fSBenjamin Peterson	  <file:Documentation/lockup-watchdogs.txt> and the SMP-HOWTO available at
406506f1d07SSam Ravnborg	  <http://www.tldp.org/docs.html#howto>.
407506f1d07SSam Ravnborg
408506f1d07SSam Ravnborg	  If you don't know what to do here, say N.
409506f1d07SSam Ravnborg
4109def39beSJosh Triplettconfig X86_FEATURE_NAMES
4119def39beSJosh Triplett	bool "Processor feature human-readable names" if EMBEDDED
4129def39beSJosh Triplett	default y
4139def39beSJosh Triplett	---help---
4149def39beSJosh Triplett	  This option compiles in a table of x86 feature bits and corresponding
4159def39beSJosh Triplett	  names.  This is required to support /proc/cpuinfo and a few kernel
4169def39beSJosh Triplett	  messages.  You can disable this to save space, at the expense of
4179def39beSJosh Triplett	  making those few kernel messages show numeric feature bits instead.
4189def39beSJosh Triplett
4199def39beSJosh Triplett	  If in doubt, say Y.
4209def39beSJosh Triplett
42106cd9a7dSYinghai Luconfig X86_X2APIC
42206cd9a7dSYinghai Lu	bool "Support x2apic"
42319e3d60dSJan Kiszka	depends on X86_LOCAL_APIC && X86_64 && (IRQ_REMAP || HYPERVISOR_GUEST)
42406cd9a7dSYinghai Lu	---help---
42506cd9a7dSYinghai Lu	  This enables x2apic support on CPUs that have this feature.
42606cd9a7dSYinghai Lu
42706cd9a7dSYinghai Lu	  This allows 32-bit apic IDs (so it can support very large systems),
42806cd9a7dSYinghai Lu	  and accesses the local apic via MSRs not via mmio.
42906cd9a7dSYinghai Lu
43006cd9a7dSYinghai Lu	  If you don't know what to do here, say N.
43106cd9a7dSYinghai Lu
4326695c85bSYinghai Luconfig X86_MPPARSE
4336e87f9b7SBin Gao	bool "Enable MPS table" if ACPI || SFI
4347a527688SJan Beulich	default y
4355ab74722SIngo Molnar	depends on X86_LOCAL_APIC
4368f9ca475SIngo Molnar	---help---
4376695c85bSYinghai Lu	  For old smp systems that do not have proper acpi support. Newer systems
4386695c85bSYinghai Lu	  (esp with 64bit cpus) with acpi support, MADT and DSDT will override it
4396695c85bSYinghai Lu
440ddd70cf9SJun Nakajimaconfig GOLDFISH
441ddd70cf9SJun Nakajima       def_bool y
442ddd70cf9SJun Nakajima       depends on X86_GOLDFISH
443ddd70cf9SJun Nakajima
44476b04384SDavid Woodhouseconfig RETPOLINE
44576b04384SDavid Woodhouse	bool "Avoid speculative indirect branches in kernel"
44676b04384SDavid Woodhouse	default y
447d5028ba8SPeter Zijlstra	select STACK_VALIDATION if HAVE_STACK_VALIDATION
44876b04384SDavid Woodhouse	help
44976b04384SDavid Woodhouse	  Compile kernel with the retpoline compiler options to guard against
45076b04384SDavid Woodhouse	  kernel-to-user data leaks by avoiding speculative indirect
45176b04384SDavid Woodhouse	  branches. Requires a compiler with -mindirect-branch=thunk-extern
45276b04384SDavid Woodhouse	  support for full protection. The kernel may run slower.
45376b04384SDavid Woodhouse
454e6d42931SJohannes Weinerconfig X86_CPU_RESCTRL
455e6d42931SJohannes Weiner	bool "x86 CPU resource control support"
4566fe07ce3SBabu Moger	depends on X86 && (CPU_SUP_INTEL || CPU_SUP_AMD)
45759fe5a77SThomas Gleixner	select KERNFS
45878e99b4aSFenghua Yu	help
459e6d42931SJohannes Weiner	  Enable x86 CPU resource control support.
4606fe07ce3SBabu Moger
4616fe07ce3SBabu Moger	  Provide support for the allocation and monitoring of system resources
4626fe07ce3SBabu Moger	  usage by the CPU.
4636fe07ce3SBabu Moger
4646fe07ce3SBabu Moger	  Intel calls this Intel Resource Director Technology
4656fe07ce3SBabu Moger	  (Intel(R) RDT). More information about RDT can be found in the
4666fe07ce3SBabu Moger	  Intel x86 Architecture Software Developer Manual.
4676fe07ce3SBabu Moger
4686fe07ce3SBabu Moger	  AMD calls this AMD Platform Quality of Service (AMD QoS).
4696fe07ce3SBabu Moger	  More information about AMD QoS can be found in the AMD64 Technology
4706fe07ce3SBabu Moger	  Platform Quality of Service Extensions manual.
47178e99b4aSFenghua Yu
47278e99b4aSFenghua Yu	  Say N if unsure.
47378e99b4aSFenghua Yu
4748425091fSRavikiran G Thirumalaiif X86_32
475a0d0bb4dSRandy Dunlapconfig X86_BIGSMP
476a0d0bb4dSRandy Dunlap	bool "Support for big SMP systems with more than 8 CPUs"
477a0d0bb4dSRandy Dunlap	depends on SMP
478a0d0bb4dSRandy Dunlap	---help---
479a0d0bb4dSRandy Dunlap	  This option is needed for the systems that have more than 8 CPUs
480a0d0bb4dSRandy Dunlap
481c5c606d9SRavikiran G Thirumalaiconfig X86_EXTENDED_PLATFORM
482c5c606d9SRavikiran G Thirumalai	bool "Support for extended (non-PC) x86 platforms"
483c5c606d9SRavikiran G Thirumalai	default y
4848f9ca475SIngo Molnar	---help---
48506ac8346SIngo Molnar	  If you disable this option then the kernel will only support
48606ac8346SIngo Molnar	  standard PC platforms. (which covers the vast majority of
48706ac8346SIngo Molnar	  systems out there.)
48806ac8346SIngo Molnar
4898425091fSRavikiran G Thirumalai	  If you enable this option then you'll be able to select support
4908425091fSRavikiran G Thirumalai	  for the following (non-PC) 32 bit x86 platforms:
491cb7b8023SBen Hutchings		Goldfish (Android emulator)
4928425091fSRavikiran G Thirumalai		AMD Elan
4938425091fSRavikiran G Thirumalai		RDC R-321x SoC
4948425091fSRavikiran G Thirumalai		SGI 320/540 (Visual Workstation)
49583125a3aSAlessandro Rubini		STA2X11-based (e.g. Northville)
4963f4110a4SThomas Gleixner		Moorestown MID devices
49706ac8346SIngo Molnar
49806ac8346SIngo Molnar	  If you have one of these systems, or if you want to build a
49906ac8346SIngo Molnar	  generic distribution kernel, say Y here - otherwise say N.
5008425091fSRavikiran G Thirumalaiendif
50106ac8346SIngo Molnar
5028425091fSRavikiran G Thirumalaiif X86_64
5038425091fSRavikiran G Thirumalaiconfig X86_EXTENDED_PLATFORM
5048425091fSRavikiran G Thirumalai	bool "Support for extended (non-PC) x86 platforms"
5058425091fSRavikiran G Thirumalai	default y
5068425091fSRavikiran G Thirumalai	---help---
5078425091fSRavikiran G Thirumalai	  If you disable this option then the kernel will only support
5088425091fSRavikiran G Thirumalai	  standard PC platforms. (which covers the vast majority of
5098425091fSRavikiran G Thirumalai	  systems out there.)
5108425091fSRavikiran G Thirumalai
5118425091fSRavikiran G Thirumalai	  If you enable this option then you'll be able to select support
5128425091fSRavikiran G Thirumalai	  for the following (non-PC) 64 bit x86 platforms:
51344b111b5SSteffen Persvold		Numascale NumaChip
5148425091fSRavikiran G Thirumalai		ScaleMP vSMP
5158425091fSRavikiran G Thirumalai		SGI Ultraviolet
5168425091fSRavikiran G Thirumalai
5178425091fSRavikiran G Thirumalai	  If you have one of these systems, or if you want to build a
5188425091fSRavikiran G Thirumalai	  generic distribution kernel, say Y here - otherwise say N.
5198425091fSRavikiran G Thirumalaiendif
520c5c606d9SRavikiran G Thirumalai# This is an alphabetically sorted list of 64 bit extended platforms
521c5c606d9SRavikiran G Thirumalai# Please maintain the alphabetic order if and when there are additions
52244b111b5SSteffen Persvoldconfig X86_NUMACHIP
52344b111b5SSteffen Persvold	bool "Numascale NumaChip"
52444b111b5SSteffen Persvold	depends on X86_64
52544b111b5SSteffen Persvold	depends on X86_EXTENDED_PLATFORM
52644b111b5SSteffen Persvold	depends on NUMA
52744b111b5SSteffen Persvold	depends on SMP
52844b111b5SSteffen Persvold	depends on X86_X2APIC
529f9726bfdSDaniel J Blueman	depends on PCI_MMCONFIG
53044b111b5SSteffen Persvold	---help---
53144b111b5SSteffen Persvold	  Adds support for Numascale NumaChip large-SMP systems. Needed to
53244b111b5SSteffen Persvold	  enable more than ~168 cores.
53344b111b5SSteffen Persvold	  If you don't have one of these, you should say N here.
53403b48632SNick Piggin
5356a48565eSIngo Molnarconfig X86_VSMP
536c5c606d9SRavikiran G Thirumalai	bool "ScaleMP vSMP"
5376276a074SBorislav Petkov	select HYPERVISOR_GUEST
5386a48565eSIngo Molnar	select PARAVIRT
5396a48565eSIngo Molnar	depends on X86_64 && PCI
540c5c606d9SRavikiran G Thirumalai	depends on X86_EXTENDED_PLATFORM
541ead91d4bSShai Fultheim	depends on SMP
5428f9ca475SIngo Molnar	---help---
5436a48565eSIngo Molnar	  Support for ScaleMP vSMP systems.  Say 'Y' here if this kernel is
5446a48565eSIngo Molnar	  supposed to run on these EM64T-based machines.  Only choose this option
5456a48565eSIngo Molnar	  if you have one of these machines.
5466a48565eSIngo Molnar
547c5c606d9SRavikiran G Thirumalaiconfig X86_UV
548c5c606d9SRavikiran G Thirumalai	bool "SGI Ultraviolet"
549c5c606d9SRavikiran G Thirumalai	depends on X86_64
550c5c606d9SRavikiran G Thirumalai	depends on X86_EXTENDED_PLATFORM
55154c28d29SJack Steiner	depends on NUMA
5521ecb4ae5SAndrew Morton	depends on EFI
5539d6c26e7SSuresh Siddha	depends on X86_X2APIC
5541222e564SIngo Molnar	depends on PCI
555c5c606d9SRavikiran G Thirumalai	---help---
556c5c606d9SRavikiran G Thirumalai	  This option is needed in order to support SGI Ultraviolet systems.
557c5c606d9SRavikiran G Thirumalai	  If you don't have one of these, you should say N here.
558c5c606d9SRavikiran G Thirumalai
559c5c606d9SRavikiran G Thirumalai# Following is an alphabetically sorted list of 32 bit extended platforms
560c5c606d9SRavikiran G Thirumalai# Please maintain the alphabetic order if and when there are additions
561506f1d07SSam Ravnborg
562ddd70cf9SJun Nakajimaconfig X86_GOLDFISH
563ddd70cf9SJun Nakajima       bool "Goldfish (Virtual Platform)"
564cb7b8023SBen Hutchings       depends on X86_EXTENDED_PLATFORM
565ddd70cf9SJun Nakajima       ---help---
566ddd70cf9SJun Nakajima	 Enable support for the Goldfish virtual platform used primarily
567ddd70cf9SJun Nakajima	 for Android development. Unless you are building for the Android
568ddd70cf9SJun Nakajima	 Goldfish emulator say N here.
569ddd70cf9SJun Nakajima
570c751e17bSThomas Gleixnerconfig X86_INTEL_CE
571c751e17bSThomas Gleixner	bool "CE4100 TV platform"
572c751e17bSThomas Gleixner	depends on PCI
573c751e17bSThomas Gleixner	depends on PCI_GODIRECT
5746084a6e2SJiang Liu	depends on X86_IO_APIC
575c751e17bSThomas Gleixner	depends on X86_32
576c751e17bSThomas Gleixner	depends on X86_EXTENDED_PLATFORM
57737bc9f50SDirk Brandewie	select X86_REBOOTFIXUPS
578da6b737bSSebastian Andrzej Siewior	select OF
579da6b737bSSebastian Andrzej Siewior	select OF_EARLY_FLATTREE
580c751e17bSThomas Gleixner	---help---
581c751e17bSThomas Gleixner	  Select for the Intel CE media processor (CE4100) SOC.
582c751e17bSThomas Gleixner	  This option compiles in support for the CE4100 SOC for settop
583c751e17bSThomas Gleixner	  boxes and media devices.
584c751e17bSThomas Gleixner
5854cb9b00fSDavid Cohenconfig X86_INTEL_MID
58643605ef1SAlan Cox	bool "Intel MID platform support"
58743605ef1SAlan Cox	depends on X86_EXTENDED_PLATFORM
588edc6bc78SDavid Cohen	depends on X86_PLATFORM_DEVICES
5891ea7c673SAlan Cox	depends on PCI
5903fda5bb4SAndy Shevchenko	depends on X86_64 || (PCI_GOANY && X86_32)
5911ea7c673SAlan Cox	depends on X86_IO_APIC
5927c9c3a1eSAlan Cox	select SFI
5934cb9b00fSDavid Cohen	select I2C
5947c9c3a1eSAlan Cox	select DW_APB_TIMER
5951ea7c673SAlan Cox	select APB_TIMER
5961ea7c673SAlan Cox	select INTEL_SCU_IPC
59715a713dfSMika Westerberg	select MFD_INTEL_MSIC
5981ea7c673SAlan Cox	---help---
5994cb9b00fSDavid Cohen	  Select to build a kernel capable of supporting Intel MID (Mobile
6004cb9b00fSDavid Cohen	  Internet Device) platform systems which do not have the PCI legacy
6014cb9b00fSDavid Cohen	  interfaces. If you are building for a PC class system say N here.
6021ea7c673SAlan Cox
6034cb9b00fSDavid Cohen	  Intel MID platforms are based on an Intel processor and chipset which
6044cb9b00fSDavid Cohen	  consume less power than most of the x86 derivatives.
60543605ef1SAlan Cox
6068bbc2a13SBryan O'Donoghueconfig X86_INTEL_QUARK
6078bbc2a13SBryan O'Donoghue	bool "Intel Quark platform support"
6088bbc2a13SBryan O'Donoghue	depends on X86_32
6098bbc2a13SBryan O'Donoghue	depends on X86_EXTENDED_PLATFORM
6108bbc2a13SBryan O'Donoghue	depends on X86_PLATFORM_DEVICES
6118bbc2a13SBryan O'Donoghue	depends on X86_TSC
6128bbc2a13SBryan O'Donoghue	depends on PCI
6138bbc2a13SBryan O'Donoghue	depends on PCI_GOANY
6148bbc2a13SBryan O'Donoghue	depends on X86_IO_APIC
6158bbc2a13SBryan O'Donoghue	select IOSF_MBI
6168bbc2a13SBryan O'Donoghue	select INTEL_IMR
6179ab6eb51SAndy Shevchenko	select COMMON_CLK
6188bbc2a13SBryan O'Donoghue	---help---
6198bbc2a13SBryan O'Donoghue	  Select to include support for Quark X1000 SoC.
6208bbc2a13SBryan O'Donoghue	  Say Y here if you have a Quark based system such as the Arduino
6218bbc2a13SBryan O'Donoghue	  compatible Intel Galileo.
6228bbc2a13SBryan O'Donoghue
6233d48aab1SMika Westerbergconfig X86_INTEL_LPSS
6243d48aab1SMika Westerberg	bool "Intel Low Power Subsystem Support"
6255962dd22SSinan Kaya	depends on X86 && ACPI && PCI
6263d48aab1SMika Westerberg	select COMMON_CLK
6270f531431SMathias Nyman	select PINCTRL
628eebb3e8dSAndy Shevchenko	select IOSF_MBI
6293d48aab1SMika Westerberg	---help---
6303d48aab1SMika Westerberg	  Select to build support for Intel Low Power Subsystem such as
6313d48aab1SMika Westerberg	  found on Intel Lynxpoint PCH. Selecting this option enables
6320f531431SMathias Nyman	  things like clock tree (common clock framework) and pincontrol
6330f531431SMathias Nyman	  which are needed by the LPSS peripheral drivers.
6343d48aab1SMika Westerberg
63592082a88SKen Xueconfig X86_AMD_PLATFORM_DEVICE
63692082a88SKen Xue	bool "AMD ACPI2Platform devices support"
63792082a88SKen Xue	depends on ACPI
63892082a88SKen Xue	select COMMON_CLK
63992082a88SKen Xue	select PINCTRL
64092082a88SKen Xue	---help---
64192082a88SKen Xue	  Select to interpret AMD specific ACPI device to platform device
64292082a88SKen Xue	  such as I2C, UART, GPIO found on AMD Carrizo and later chipsets.
64392082a88SKen Xue	  I2C and UART depend on COMMON_CLK to set clock. GPIO driver is
64492082a88SKen Xue	  implemented under PINCTRL subsystem.
64592082a88SKen Xue
646ced3ce76SDavid E. Boxconfig IOSF_MBI
647ced3ce76SDavid E. Box	tristate "Intel SoC IOSF Sideband support for SoC platforms"
648ced3ce76SDavid E. Box	depends on PCI
649ced3ce76SDavid E. Box	---help---
650ced3ce76SDavid E. Box	  This option enables sideband register access support for Intel SoC
651ced3ce76SDavid E. Box	  platforms. On these platforms the IOSF sideband is used in lieu of
652ced3ce76SDavid E. Box	  MSR's for some register accesses, mostly but not limited to thermal
653ced3ce76SDavid E. Box	  and power. Drivers may query the availability of this device to
654ced3ce76SDavid E. Box	  determine if they need the sideband in order to work on these
655ced3ce76SDavid E. Box	  platforms. The sideband is available on the following SoC products.
656ced3ce76SDavid E. Box	  This list is not meant to be exclusive.
657ced3ce76SDavid E. Box	   - BayTrail
658ced3ce76SDavid E. Box	   - Braswell
659ced3ce76SDavid E. Box	   - Quark
660ced3ce76SDavid E. Box
661ced3ce76SDavid E. Box	  You should say Y if you are running a kernel on one of these SoC's.
662ced3ce76SDavid E. Box
663ed2226bdSDavid E. Boxconfig IOSF_MBI_DEBUG
664ed2226bdSDavid E. Box	bool "Enable IOSF sideband access through debugfs"
665ed2226bdSDavid E. Box	depends on IOSF_MBI && DEBUG_FS
666ed2226bdSDavid E. Box	---help---
667ed2226bdSDavid E. Box	  Select this option to expose the IOSF sideband access registers (MCR,
668ed2226bdSDavid E. Box	  MDR, MCRX) through debugfs to write and read register information from
669ed2226bdSDavid E. Box	  different units on the SoC. This is most useful for obtaining device
670ed2226bdSDavid E. Box	  state information for debug and analysis. As this is a general access
671ed2226bdSDavid E. Box	  mechanism, users of this option would have specific knowledge of the
672ed2226bdSDavid E. Box	  device they want to access.
673ed2226bdSDavid E. Box
674ed2226bdSDavid E. Box	  If you don't require the option or are in doubt, say N.
675ed2226bdSDavid E. Box
676c5c606d9SRavikiran G Thirumalaiconfig X86_RDC321X
677c5c606d9SRavikiran G Thirumalai	bool "RDC R-321x SoC"
678506f1d07SSam Ravnborg	depends on X86_32
679c5c606d9SRavikiran G Thirumalai	depends on X86_EXTENDED_PLATFORM
680c5c606d9SRavikiran G Thirumalai	select M486
681c5c606d9SRavikiran G Thirumalai	select X86_REBOOTFIXUPS
682c5c606d9SRavikiran G Thirumalai	---help---
683c5c606d9SRavikiran G Thirumalai	  This option is needed for RDC R-321x system-on-chip, also known
684c5c606d9SRavikiran G Thirumalai	  as R-8610-(G).
685c5c606d9SRavikiran G Thirumalai	  If you don't have one of these chips, you should say N here.
686c5c606d9SRavikiran G Thirumalai
687e0c7ae37SIngo Molnarconfig X86_32_NON_STANDARD
6889c398017SIngo Molnar	bool "Support non-standard 32-bit SMP architectures"
6899c398017SIngo Molnar	depends on X86_32 && SMP
690c5c606d9SRavikiran G Thirumalai	depends on X86_EXTENDED_PLATFORM
6918f9ca475SIngo Molnar	---help---
692b5660ba7SH. Peter Anvin	  This option compiles in the bigsmp and STA2X11 default
693b5660ba7SH. Peter Anvin	  subarchitectures.  It is intended for a generic binary
694b5660ba7SH. Peter Anvin	  kernel. If you select them all, kernel will probe it one by
695b5660ba7SH. Peter Anvin	  one and will fallback to default.
696d49c4288SYinghai Lu
697c5c606d9SRavikiran G Thirumalai# Alphabetically sorted list of Non standard 32 bit platforms
698d49c4288SYinghai Lu
699d949f36fSLinus Torvaldsconfig X86_SUPPORTS_MEMORY_FAILURE
7006fc108a0SJan Beulich	def_bool y
701d949f36fSLinus Torvalds	# MCE code calls memory_failure():
702d949f36fSLinus Torvalds	depends on X86_MCE
703d949f36fSLinus Torvalds	# On 32-bit this adds too big of NODES_SHIFT and we run out of page flags:
704d949f36fSLinus Torvalds	# On 32-bit SPARSEMEM adds too big of SECTIONS_WIDTH:
705d949f36fSLinus Torvalds	depends on X86_64 || !SPARSEMEM
706d949f36fSLinus Torvalds	select ARCH_SUPPORTS_MEMORY_FAILURE
707d949f36fSLinus Torvalds
70883125a3aSAlessandro Rubiniconfig STA2X11
70983125a3aSAlessandro Rubini	bool "STA2X11 Companion Chip Support"
71083125a3aSAlessandro Rubini	depends on X86_32_NON_STANDARD && PCI
711b6e05477SChristoph Hellwig	select ARCH_HAS_PHYS_TO_DMA
71283125a3aSAlessandro Rubini	select SWIOTLB
71383125a3aSAlessandro Rubini	select MFD_STA2X11
7140145071bSLinus Walleij	select GPIOLIB
71583125a3aSAlessandro Rubini	---help---
71683125a3aSAlessandro Rubini	  This adds support for boards based on the STA2X11 IO-Hub,
71783125a3aSAlessandro Rubini	  a.k.a. "ConneXt". The chip is used in place of the standard
71883125a3aSAlessandro Rubini	  PC chipset, so all "standard" peripherals are missing. If this
71983125a3aSAlessandro Rubini	  option is selected the kernel will still be able to boot on
72083125a3aSAlessandro Rubini	  standard PC machines.
72183125a3aSAlessandro Rubini
72282148d1dSShérabconfig X86_32_IRIS
72382148d1dSShérab	tristate "Eurobraille/Iris poweroff module"
72482148d1dSShérab	depends on X86_32
72582148d1dSShérab	---help---
72682148d1dSShérab	  The Iris machines from EuroBraille do not have APM or ACPI support
72782148d1dSShérab	  to shut themselves down properly.  A special I/O sequence is
72882148d1dSShérab	  needed to do so, which is what this module does at
72982148d1dSShérab	  kernel shutdown.
73082148d1dSShérab
73182148d1dSShérab	  This is only for Iris machines from EuroBraille.
73282148d1dSShérab
73382148d1dSShérab	  If unused, say N.
73482148d1dSShérab
735ae1e9130SIngo Molnarconfig SCHED_OMIT_FRAME_POINTER
7363c2362e6SHarvey Harrison	def_bool y
7373c2362e6SHarvey Harrison	prompt "Single-depth WCHAN output"
738a87d0914SKen Chen	depends on X86
7398f9ca475SIngo Molnar	---help---
740506f1d07SSam Ravnborg	  Calculate simpler /proc/<PID>/wchan values. If this option
741506f1d07SSam Ravnborg	  is disabled then wchan values will recurse back to the
742506f1d07SSam Ravnborg	  caller function. This provides more accurate wchan values,
743506f1d07SSam Ravnborg	  at the expense of slightly more scheduling overhead.
744506f1d07SSam Ravnborg
745506f1d07SSam Ravnborg	  If in doubt, say "Y".
746506f1d07SSam Ravnborg
7476276a074SBorislav Petkovmenuconfig HYPERVISOR_GUEST
7486276a074SBorislav Petkov	bool "Linux guest support"
7498f9ca475SIngo Molnar	---help---
7506276a074SBorislav Petkov	  Say Y here to enable options for running Linux under various hyper-
7516276a074SBorislav Petkov	  visors. This option enables basic hypervisor detection and platform
7526276a074SBorislav Petkov	  setup.
753506f1d07SSam Ravnborg
7546276a074SBorislav Petkov	  If you say N, all options in this submenu will be skipped and
7556276a074SBorislav Petkov	  disabled, and Linux guest support won't be built in.
756506f1d07SSam Ravnborg
7576276a074SBorislav Petkovif HYPERVISOR_GUEST
758506f1d07SSam Ravnborg
759e61bd94aSEduardo Pereira Habkostconfig PARAVIRT
760e61bd94aSEduardo Pereira Habkost	bool "Enable paravirtualization code"
7618f9ca475SIngo Molnar	---help---
762e61bd94aSEduardo Pereira Habkost	  This changes the kernel so it can modify itself when it is run
763e61bd94aSEduardo Pereira Habkost	  under a hypervisor, potentially improving performance significantly
764e61bd94aSEduardo Pereira Habkost	  over full virtualization.  However, when run without a hypervisor
765e61bd94aSEduardo Pereira Habkost	  the kernel is theoretically slower and slightly larger.
766e61bd94aSEduardo Pereira Habkost
767c00a280aSJuergen Grossconfig PARAVIRT_XXL
768c00a280aSJuergen Gross	bool
769c00a280aSJuergen Gross
7706276a074SBorislav Petkovconfig PARAVIRT_DEBUG
7716276a074SBorislav Petkov	bool "paravirt-ops debugging"
7726276a074SBorislav Petkov	depends on PARAVIRT && DEBUG_KERNEL
7736276a074SBorislav Petkov	---help---
7746276a074SBorislav Petkov	  Enable to debug paravirt_ops internals.  Specifically, BUG if
7756276a074SBorislav Petkov	  a paravirt_op is missing when it is called.
7766276a074SBorislav Petkov
777b4ecc126SJeremy Fitzhardingeconfig PARAVIRT_SPINLOCKS
778b4ecc126SJeremy Fitzhardinge	bool "Paravirtualization layer for spinlocks"
7796ea30386SKees Cook	depends on PARAVIRT && SMP
780b4ecc126SJeremy Fitzhardinge	---help---
781b4ecc126SJeremy Fitzhardinge	  Paravirtualized spinlocks allow a pvops backend to replace the
782b4ecc126SJeremy Fitzhardinge	  spinlock implementation with something virtualization-friendly
783b4ecc126SJeremy Fitzhardinge	  (for example, block the virtual CPU rather than spinning).
784b4ecc126SJeremy Fitzhardinge
7854c4e4f61SRaghavendra K T	  It has a minimal impact on native kernels and gives a nice performance
7864c4e4f61SRaghavendra K T	  benefit on paravirtualized KVM / Xen kernels.
787b4ecc126SJeremy Fitzhardinge
7884c4e4f61SRaghavendra K T	  If you are unsure how to answer this question, answer Y.
789b4ecc126SJeremy Fitzhardinge
790ecca2502SZhao Yakuiconfig X86_HV_CALLBACK_VECTOR
791ecca2502SZhao Yakui	def_bool n
792ecca2502SZhao Yakui
7936276a074SBorislav Petkovsource "arch/x86/xen/Kconfig"
7946276a074SBorislav Petkov
7956276a074SBorislav Petkovconfig KVM_GUEST
7966276a074SBorislav Petkov	bool "KVM Guest support (including kvmclock)"
7976276a074SBorislav Petkov	depends on PARAVIRT
7986276a074SBorislav Petkov	select PARAVIRT_CLOCK
7996276a074SBorislav Petkov	default y
8006276a074SBorislav Petkov	---help---
8016276a074SBorislav Petkov	  This option enables various optimizations for running under the KVM
8026276a074SBorislav Petkov	  hypervisor. It includes a paravirtualized clock, so that instead
8036276a074SBorislav Petkov	  of relying on a PIT (or probably other) emulation by the
8046276a074SBorislav Petkov	  underlying device model, the host provides the guest with
8056276a074SBorislav Petkov	  timing infrastructure such as time of day, and system time
8066276a074SBorislav Petkov
8077733607fSMaran Wilsonconfig PVH
8087733607fSMaran Wilson	bool "Support for running PVH guests"
8097733607fSMaran Wilson	---help---
8107733607fSMaran Wilson	  This option enables the PVH entry point for guest virtual machines
8117733607fSMaran Wilson	  as specified in the x86/HVM direct boot ABI.
8127733607fSMaran Wilson
8131e20eb85SSrivatsa Vaddagiriconfig KVM_DEBUG_FS
8141e20eb85SSrivatsa Vaddagiri	bool "Enable debug information for KVM Guests in debugfs"
8151e20eb85SSrivatsa Vaddagiri	depends on KVM_GUEST && DEBUG_FS
8161e20eb85SSrivatsa Vaddagiri	---help---
8171e20eb85SSrivatsa Vaddagiri	  This option enables collection of various statistics for KVM guest.
8181e20eb85SSrivatsa Vaddagiri	  Statistics are displayed in debugfs filesystem. Enabling this option
8191e20eb85SSrivatsa Vaddagiri	  may incur significant overhead.
8201e20eb85SSrivatsa Vaddagiri
8216276a074SBorislav Petkovconfig PARAVIRT_TIME_ACCOUNTING
8226276a074SBorislav Petkov	bool "Paravirtual steal time accounting"
8236276a074SBorislav Petkov	depends on PARAVIRT
8246276a074SBorislav Petkov	---help---
8256276a074SBorislav Petkov	  Select this option to enable fine granularity task steal time
8266276a074SBorislav Petkov	  accounting. Time spent executing other tasks in parallel with
8276276a074SBorislav Petkov	  the current vCPU is discounted from the vCPU power. To account for
8286276a074SBorislav Petkov	  that, there can be a small performance impact.
8296276a074SBorislav Petkov
8306276a074SBorislav Petkov	  If in doubt, say N here.
8316276a074SBorislav Petkov
8327af192c9SGerd Hoffmannconfig PARAVIRT_CLOCK
8337af192c9SGerd Hoffmann	bool
8347af192c9SGerd Hoffmann
8354a362601SJan Kiszkaconfig JAILHOUSE_GUEST
8364a362601SJan Kiszka	bool "Jailhouse non-root cell support"
837abde587bSArnd Bergmann	depends on X86_64 && PCI
83887e65d05SJan Kiszka	select X86_PM_TIMER
8394a362601SJan Kiszka	---help---
8404a362601SJan Kiszka	  This option allows to run Linux as guest in a Jailhouse non-root
8414a362601SJan Kiszka	  cell. You can leave this option disabled if you only want to start
8424a362601SJan Kiszka	  Jailhouse and run Linux afterwards in the root cell.
8434a362601SJan Kiszka
844ec7972c9SZhao Yakuiconfig ACRN_GUEST
845ec7972c9SZhao Yakui	bool "ACRN Guest support"
846ec7972c9SZhao Yakui	depends on X86_64
847498ad393SZhao Yakui	select X86_HV_CALLBACK_VECTOR
848ec7972c9SZhao Yakui	help
849ec7972c9SZhao Yakui	  This option allows to run Linux as guest in the ACRN hypervisor. ACRN is
850ec7972c9SZhao Yakui	  a flexible, lightweight reference open-source hypervisor, built with
851ec7972c9SZhao Yakui	  real-time and safety-criticality in mind. It is built for embedded
852ec7972c9SZhao Yakui	  IOT with small footprint and real-time features. More details can be
853ec7972c9SZhao Yakui	  found in https://projectacrn.org/.
854ec7972c9SZhao Yakui
8556276a074SBorislav Petkovendif #HYPERVISOR_GUEST
85697349135SJeremy Fitzhardinge
857506f1d07SSam Ravnborgsource "arch/x86/Kconfig.cpu"
858506f1d07SSam Ravnborg
859506f1d07SSam Ravnborgconfig HPET_TIMER
8603c2362e6SHarvey Harrison	def_bool X86_64
861506f1d07SSam Ravnborg	prompt "HPET Timer Support" if X86_32
8628f9ca475SIngo Molnar	---help---
863506f1d07SSam Ravnborg	  Use the IA-PC HPET (High Precision Event Timer) to manage
864506f1d07SSam Ravnborg	  time in preference to the PIT and RTC, if a HPET is
865506f1d07SSam Ravnborg	  present.
866506f1d07SSam Ravnborg	  HPET is the next generation timer replacing legacy 8254s.
867506f1d07SSam Ravnborg	  The HPET provides a stable time base on SMP
868506f1d07SSam Ravnborg	  systems, unlike the TSC, but it is more expensive to access,
8694e7f9df2SMichael S. Tsirkin	  as it is off-chip.  The interface used is documented
8704e7f9df2SMichael S. Tsirkin	  in the HPET spec, revision 1.
871506f1d07SSam Ravnborg
872506f1d07SSam Ravnborg	  You can safely choose Y here.  However, HPET will only be
873506f1d07SSam Ravnborg	  activated if the platform and the BIOS support this feature.
874506f1d07SSam Ravnborg	  Otherwise the 8254 will be used for timing services.
875506f1d07SSam Ravnborg
876506f1d07SSam Ravnborg	  Choose N to continue using the legacy 8254 timer.
877506f1d07SSam Ravnborg
878506f1d07SSam Ravnborgconfig HPET_EMULATE_RTC
8793c2362e6SHarvey Harrison	def_bool y
8809d8af78bSBernhard Walle	depends on HPET_TIMER && (RTC=y || RTC=m || RTC_DRV_CMOS=m || RTC_DRV_CMOS=y)
881506f1d07SSam Ravnborg
882bb24c471SJacob Panconfig APB_TIMER
883933b9463SAlan Cox       def_bool y if X86_INTEL_MID
884933b9463SAlan Cox       prompt "Intel MID APB Timer Support" if X86_INTEL_MID
88506c3df49SJamie Iles       select DW_APB_TIMER
886a0c3832aSAlan Cox       depends on X86_INTEL_MID && SFI
887bb24c471SJacob Pan       help
888bb24c471SJacob Pan         APB timer is the replacement for 8254, HPET on X86 MID platforms.
889bb24c471SJacob Pan         The APBT provides a stable time base on SMP
890bb24c471SJacob Pan         systems, unlike the TSC, but it is more expensive to access,
891bb24c471SJacob Pan         as it is off-chip. APB timers are always running regardless of CPU
892bb24c471SJacob Pan         C states, they are used as per CPU clockevent device when possible.
893bb24c471SJacob Pan
8946a108a14SDavid Rientjes# Mark as expert because too many people got it wrong.
895506f1d07SSam Ravnborg# The code disables itself when not needed.
8967ae9392cSThomas Petazzoniconfig DMI
8977ae9392cSThomas Petazzoni	default y
898cf074402SArd Biesheuvel	select DMI_SCAN_MACHINE_NON_EFI_FALLBACK
8996a108a14SDavid Rientjes	bool "Enable DMI scanning" if EXPERT
9008f9ca475SIngo Molnar	---help---
9017ae9392cSThomas Petazzoni	  Enabled scanning of DMI to identify machine quirks. Say Y
9027ae9392cSThomas Petazzoni	  here unless you have verified that your setup is not
9037ae9392cSThomas Petazzoni	  affected by entries in the DMI blacklist. Required by PNP
9047ae9392cSThomas Petazzoni	  BIOS code.
9057ae9392cSThomas Petazzoni
906506f1d07SSam Ravnborgconfig GART_IOMMU
90738901f1cSAndi Kleen	bool "Old AMD GART IOMMU support"
908a4ce5a48SChristoph Hellwig	select IOMMU_HELPER
909506f1d07SSam Ravnborg	select SWIOTLB
91023ac4ae8SAndreas Herrmann	depends on X86_64 && PCI && AMD_NB
9118f9ca475SIngo Molnar	---help---
912ced3c42cSIngo Molnar	  Provides a driver for older AMD Athlon64/Opteron/Turion/Sempron
913ced3c42cSIngo Molnar	  GART based hardware IOMMUs.
914ced3c42cSIngo Molnar
915ced3c42cSIngo Molnar	  The GART supports full DMA access for devices with 32-bit access
916ced3c42cSIngo Molnar	  limitations, on systems with more than 3 GB. This is usually needed
917ced3c42cSIngo Molnar	  for USB, sound, many IDE/SATA chipsets and some other devices.
918ced3c42cSIngo Molnar
919ced3c42cSIngo Molnar	  Newer systems typically have a modern AMD IOMMU, supported via
920ced3c42cSIngo Molnar	  the CONFIG_AMD_IOMMU=y config option.
921ced3c42cSIngo Molnar
922ced3c42cSIngo Molnar	  In normal configurations this driver is only active when needed:
923ced3c42cSIngo Molnar	  there's more than 3 GB of memory and the system contains a
924ced3c42cSIngo Molnar	  32-bit limited device.
925ced3c42cSIngo Molnar
926ced3c42cSIngo Molnar	  If unsure, say Y.
927506f1d07SSam Ravnborg
928506f1d07SSam Ravnborgconfig CALGARY_IOMMU
929506f1d07SSam Ravnborg	bool "IBM Calgary IOMMU support"
930a4ce5a48SChristoph Hellwig	select IOMMU_HELPER
931506f1d07SSam Ravnborg	select SWIOTLB
9326ea30386SKees Cook	depends on X86_64 && PCI
9338f9ca475SIngo Molnar	---help---
934506f1d07SSam Ravnborg	  Support for hardware IOMMUs in IBM's xSeries x366 and x460
935506f1d07SSam Ravnborg	  systems. Needed to run systems with more than 3GB of memory
936506f1d07SSam Ravnborg	  properly with 32-bit PCI devices that do not support DAC
937506f1d07SSam Ravnborg	  (Double Address Cycle). Calgary also supports bus level
938506f1d07SSam Ravnborg	  isolation, where all DMAs pass through the IOMMU.  This
939506f1d07SSam Ravnborg	  prevents them from going anywhere except their intended
940506f1d07SSam Ravnborg	  destination. This catches hard-to-find kernel bugs and
941506f1d07SSam Ravnborg	  mis-behaving drivers and devices that do not use the DMA-API
942506f1d07SSam Ravnborg	  properly to set up their DMA buffers.  The IOMMU can be
943506f1d07SSam Ravnborg	  turned off at boot time with the iommu=off parameter.
944506f1d07SSam Ravnborg	  Normally the kernel will make the right choice by itself.
945506f1d07SSam Ravnborg	  If unsure, say Y.
946506f1d07SSam Ravnborg
947506f1d07SSam Ravnborgconfig CALGARY_IOMMU_ENABLED_BY_DEFAULT
9483c2362e6SHarvey Harrison	def_bool y
9493c2362e6SHarvey Harrison	prompt "Should Calgary be enabled by default?"
950506f1d07SSam Ravnborg	depends on CALGARY_IOMMU
9518f9ca475SIngo Molnar	---help---
952506f1d07SSam Ravnborg	  Should Calgary be enabled by default? if you choose 'y', Calgary
953506f1d07SSam Ravnborg	  will be used (if it exists). If you choose 'n', Calgary will not be
954506f1d07SSam Ravnborg	  used even if it exists. If you choose 'n' and would like to use
955506f1d07SSam Ravnborg	  Calgary anyway, pass 'iommu=calgary' on the kernel command line.
956506f1d07SSam Ravnborg	  If unsure, say Y.
957506f1d07SSam Ravnborg
9581184dc2fSMike Travisconfig MAXSMP
959ddb0c5a6SSamuel Thibault	bool "Enable Maximum number of SMP Processors and NUMA Nodes"
9606ea30386SKees Cook	depends on X86_64 && SMP && DEBUG_KERNEL
96136f5101aSMike Travis	select CPUMASK_OFFSTACK
9628f9ca475SIngo Molnar	---help---
963ddb0c5a6SSamuel Thibault	  Enable maximum number of CPUS and NUMA Nodes for this architecture.
9641184dc2fSMike Travis	  If unsure, say N.
965506f1d07SSam Ravnborg
966aec6487eSIngo Molnar#
967aec6487eSIngo Molnar# The maximum number of CPUs supported:
968aec6487eSIngo Molnar#
969aec6487eSIngo Molnar# The main config value is NR_CPUS, which defaults to NR_CPUS_DEFAULT,
970aec6487eSIngo Molnar# and which can be configured interactively in the
971aec6487eSIngo Molnar# [NR_CPUS_RANGE_BEGIN ... NR_CPUS_RANGE_END] range.
972aec6487eSIngo Molnar#
973aec6487eSIngo Molnar# The ranges are different on 32-bit and 64-bit kernels, depending on
974aec6487eSIngo Molnar# hardware capabilities and scalability features of the kernel.
975aec6487eSIngo Molnar#
976aec6487eSIngo Molnar# ( If MAXSMP is enabled we just use the highest possible value and disable
977aec6487eSIngo Molnar#   interactive configuration. )
978aec6487eSIngo Molnar#
979a0d0bb4dSRandy Dunlap
980aec6487eSIngo Molnarconfig NR_CPUS_RANGE_BEGIN
981a0d0bb4dSRandy Dunlap	int
982aec6487eSIngo Molnar	default NR_CPUS_RANGE_END if MAXSMP
983a0d0bb4dSRandy Dunlap	default    1 if !SMP
984a0d0bb4dSRandy Dunlap	default    2
985a0d0bb4dSRandy Dunlap
986aec6487eSIngo Molnarconfig NR_CPUS_RANGE_END
987a0d0bb4dSRandy Dunlap	int
988a0d0bb4dSRandy Dunlap	depends on X86_32
989aec6487eSIngo Molnar	default   64 if  SMP &&  X86_BIGSMP
990aec6487eSIngo Molnar	default    8 if  SMP && !X86_BIGSMP
991a0d0bb4dSRandy Dunlap	default    1 if !SMP
992a0d0bb4dSRandy Dunlap
993aec6487eSIngo Molnarconfig NR_CPUS_RANGE_END
994a0d0bb4dSRandy Dunlap	int
995a0d0bb4dSRandy Dunlap	depends on X86_64
996aec6487eSIngo Molnar	default 8192 if  SMP && ( MAXSMP ||  CPUMASK_OFFSTACK)
997aec6487eSIngo Molnar	default  512 if  SMP && (!MAXSMP && !CPUMASK_OFFSTACK)
998a0d0bb4dSRandy Dunlap	default    1 if !SMP
999aec6487eSIngo Molnar
1000aec6487eSIngo Molnarconfig NR_CPUS_DEFAULT
1001aec6487eSIngo Molnar	int
1002aec6487eSIngo Molnar	depends on X86_32
1003aec6487eSIngo Molnar	default   32 if  X86_BIGSMP
1004aec6487eSIngo Molnar	default    8 if  SMP
1005aec6487eSIngo Molnar	default    1 if !SMP
1006aec6487eSIngo Molnar
1007aec6487eSIngo Molnarconfig NR_CPUS_DEFAULT
1008aec6487eSIngo Molnar	int
1009aec6487eSIngo Molnar	depends on X86_64
1010a0d0bb4dSRandy Dunlap	default 8192 if  MAXSMP
1011a0d0bb4dSRandy Dunlap	default   64 if  SMP
1012aec6487eSIngo Molnar	default    1 if !SMP
1013a0d0bb4dSRandy Dunlap
1014506f1d07SSam Ravnborgconfig NR_CPUS
101536f5101aSMike Travis	int "Maximum number of CPUs" if SMP && !MAXSMP
1016aec6487eSIngo Molnar	range NR_CPUS_RANGE_BEGIN NR_CPUS_RANGE_END
1017aec6487eSIngo Molnar	default NR_CPUS_DEFAULT
10188f9ca475SIngo Molnar	---help---
1019506f1d07SSam Ravnborg	  This allows you to specify the maximum number of CPUs which this
1020bb61ccc7SJosh Boyer	  kernel will support.  If CPUMASK_OFFSTACK is enabled, the maximum
1021cad14bb9SKirill A. Shutemov	  supported value is 8192, otherwise the maximum value is 512.  The
1022506f1d07SSam Ravnborg	  minimum value which makes sense is 2.
1023506f1d07SSam Ravnborg
1024aec6487eSIngo Molnar	  This is purely to save memory: each supported CPU adds about 8KB
1025aec6487eSIngo Molnar	  to the kernel image.
1026506f1d07SSam Ravnborg
1027506f1d07SSam Ravnborgconfig SCHED_SMT
1028dbe73364SThomas Gleixner	def_bool y if SMP
1029506f1d07SSam Ravnborg
1030506f1d07SSam Ravnborgconfig SCHED_MC
10313c2362e6SHarvey Harrison	def_bool y
10323c2362e6SHarvey Harrison	prompt "Multi-core scheduler support"
1033c8e56d20SBorislav Petkov	depends on SMP
10348f9ca475SIngo Molnar	---help---
1035506f1d07SSam Ravnborg	  Multi-core scheduler support improves the CPU scheduler's decision
1036506f1d07SSam Ravnborg	  making when dealing with multi-core CPU chips at a cost of slightly
1037506f1d07SSam Ravnborg	  increased overhead in some places. If unsure say N here.
1038506f1d07SSam Ravnborg
1039de966cf4STim Chenconfig SCHED_MC_PRIO
1040de966cf4STim Chen	bool "CPU core priorities scheduler support"
10410a21fc12SIngo Molnar	depends on SCHED_MC && CPU_SUP_INTEL
10420a21fc12SIngo Molnar	select X86_INTEL_PSTATE
10430a21fc12SIngo Molnar	select CPU_FREQ
1044de966cf4STim Chen	default y
10455e76b2abSTim Chen	---help---
1046de966cf4STim Chen	  Intel Turbo Boost Max Technology 3.0 enabled CPUs have a
1047de966cf4STim Chen	  core ordering determined at manufacturing time, which allows
1048de966cf4STim Chen	  certain cores to reach higher turbo frequencies (when running
1049de966cf4STim Chen	  single threaded workloads) than others.
1050de966cf4STim Chen
1051de966cf4STim Chen	  Enabling this kernel feature teaches the scheduler about
1052de966cf4STim Chen	  the TBM3 (aka ITMT) priority order of the CPU cores and adjusts the
1053de966cf4STim Chen	  scheduler's CPU selection logic accordingly, so that higher
1054de966cf4STim Chen	  overall system performance can be achieved.
1055de966cf4STim Chen
1056de966cf4STim Chen	  This feature will have no effect on CPUs without this feature.
1057de966cf4STim Chen
1058de966cf4STim Chen	  If unsure say Y here.
10595e76b2abSTim Chen
106030b8b006SThomas Gleixnerconfig UP_LATE_INIT
106130b8b006SThomas Gleixner       def_bool y
1062ba360f88SThomas Gleixner       depends on !SMP && X86_LOCAL_APIC
106330b8b006SThomas Gleixner
1064506f1d07SSam Ravnborgconfig X86_UP_APIC
106550849eefSJan Beulich	bool "Local APIC support on uniprocessors" if !PCI_MSI
106650849eefSJan Beulich	default PCI_MSI
106738a1dfdaSBryan O'Donoghue	depends on X86_32 && !SMP && !X86_32_NON_STANDARD
10688f9ca475SIngo Molnar	---help---
1069506f1d07SSam Ravnborg	  A local APIC (Advanced Programmable Interrupt Controller) is an
1070506f1d07SSam Ravnborg	  integrated interrupt controller in the CPU. If you have a single-CPU
1071506f1d07SSam Ravnborg	  system which has a processor with a local APIC, you can say Y here to
1072506f1d07SSam Ravnborg	  enable and use it. If you say Y here even though your machine doesn't
1073506f1d07SSam Ravnborg	  have a local APIC, then the kernel will still run with no slowdown at
1074506f1d07SSam Ravnborg	  all. The local APIC supports CPU-generated self-interrupts (timer,
1075506f1d07SSam Ravnborg	  performance counters), and the NMI watchdog which detects hard
1076506f1d07SSam Ravnborg	  lockups.
1077506f1d07SSam Ravnborg
1078506f1d07SSam Ravnborgconfig X86_UP_IOAPIC
1079506f1d07SSam Ravnborg	bool "IO-APIC support on uniprocessors"
1080506f1d07SSam Ravnborg	depends on X86_UP_APIC
10818f9ca475SIngo Molnar	---help---
1082506f1d07SSam Ravnborg	  An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an
1083506f1d07SSam Ravnborg	  SMP-capable replacement for PC-style interrupt controllers. Most
1084506f1d07SSam Ravnborg	  SMP systems and many recent uniprocessor systems have one.
1085506f1d07SSam Ravnborg
1086506f1d07SSam Ravnborg	  If you have a single-CPU system with an IO-APIC, you can say Y here
1087506f1d07SSam Ravnborg	  to use it. If you say Y here even though your machine doesn't have
1088506f1d07SSam Ravnborg	  an IO-APIC, then the kernel will still run with no slowdown at all.
1089506f1d07SSam Ravnborg
1090506f1d07SSam Ravnborgconfig X86_LOCAL_APIC
10913c2362e6SHarvey Harrison	def_bool y
10920dbc6078SThomas Petazzoni	depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC || PCI_MSI
1093b5dc8e6cSJiang Liu	select IRQ_DOMAIN_HIERARCHY
109452f518a3SJiang Liu	select PCI_MSI_IRQ_DOMAIN if PCI_MSI
1095506f1d07SSam Ravnborg
1096506f1d07SSam Ravnborgconfig X86_IO_APIC
1097b1da1e71SJan Beulich	def_bool y
1098b1da1e71SJan Beulich	depends on X86_LOCAL_APIC || X86_UP_IOAPIC
1099506f1d07SSam Ravnborg
110041b9eb26SStefan Assmannconfig X86_REROUTE_FOR_BROKEN_BOOT_IRQS
110141b9eb26SStefan Assmann	bool "Reroute for broken boot IRQs"
110241b9eb26SStefan Assmann	depends on X86_IO_APIC
11038f9ca475SIngo Molnar	---help---
110441b9eb26SStefan Assmann	  This option enables a workaround that fixes a source of
110541b9eb26SStefan Assmann	  spurious interrupts. This is recommended when threaded
110641b9eb26SStefan Assmann	  interrupt handling is used on systems where the generation of
110741b9eb26SStefan Assmann	  superfluous "boot interrupts" cannot be disabled.
110841b9eb26SStefan Assmann
110941b9eb26SStefan Assmann	  Some chipsets generate a legacy INTx "boot IRQ" when the IRQ
111041b9eb26SStefan Assmann	  entry in the chipset's IO-APIC is masked (as, e.g. the RT
111141b9eb26SStefan Assmann	  kernel does during interrupt handling). On chipsets where this
111241b9eb26SStefan Assmann	  boot IRQ generation cannot be disabled, this workaround keeps
111341b9eb26SStefan Assmann	  the original IRQ line masked so that only the equivalent "boot
111441b9eb26SStefan Assmann	  IRQ" is delivered to the CPUs. The workaround also tells the
111541b9eb26SStefan Assmann	  kernel to set up the IRQ handler on the boot IRQ line. In this
111641b9eb26SStefan Assmann	  way only one interrupt is delivered to the kernel. Otherwise
111741b9eb26SStefan Assmann	  the spurious second interrupt may cause the kernel to bring
111841b9eb26SStefan Assmann	  down (vital) interrupt lines.
111941b9eb26SStefan Assmann
112041b9eb26SStefan Assmann	  Only affects "broken" chipsets. Interrupt sharing may be
112141b9eb26SStefan Assmann	  increased on these systems.
112241b9eb26SStefan Assmann
1123506f1d07SSam Ravnborgconfig X86_MCE
1124bab9bc65SAndi Kleen	bool "Machine Check / overheating reporting"
1125648ed940SChen, Gong	select GENERIC_ALLOCATOR
1126e57dbaf7SBorislav Petkov	default y
1127506f1d07SSam Ravnborg	---help---
1128bab9bc65SAndi Kleen	  Machine Check support allows the processor to notify the
1129bab9bc65SAndi Kleen	  kernel if it detects a problem (e.g. overheating, data corruption).
1130506f1d07SSam Ravnborg	  The action the kernel takes depends on the severity of the problem,
1131bab9bc65SAndi Kleen	  ranging from warning messages to halting the machine.
11324efc0670SAndi Kleen
11335de97c9fSTony Luckconfig X86_MCELOG_LEGACY
11345de97c9fSTony Luck	bool "Support for deprecated /dev/mcelog character device"
11355de97c9fSTony Luck	depends on X86_MCE
11365de97c9fSTony Luck	---help---
11375de97c9fSTony Luck	  Enable support for /dev/mcelog which is needed by the old mcelog
11385de97c9fSTony Luck	  userspace logging daemon. Consider switching to the new generation
11395de97c9fSTony Luck	  rasdaemon solution.
11405de97c9fSTony Luck
1141506f1d07SSam Ravnborgconfig X86_MCE_INTEL
11423c2362e6SHarvey Harrison	def_bool y
11433c2362e6SHarvey Harrison	prompt "Intel MCE features"
1144c1ebf835SAndi Kleen	depends on X86_MCE && X86_LOCAL_APIC
11458f9ca475SIngo Molnar	---help---
1146506f1d07SSam Ravnborg	   Additional support for intel specific MCE features such as
1147506f1d07SSam Ravnborg	   the thermal monitor.
1148506f1d07SSam Ravnborg
1149506f1d07SSam Ravnborgconfig X86_MCE_AMD
11503c2362e6SHarvey Harrison	def_bool y
11513c2362e6SHarvey Harrison	prompt "AMD MCE features"
1152f5382de9SYazen Ghannam	depends on X86_MCE && X86_LOCAL_APIC && AMD_NB
11538f9ca475SIngo Molnar	---help---
1154506f1d07SSam Ravnborg	   Additional support for AMD specific MCE features such as
1155506f1d07SSam Ravnborg	   the DRAM Error Threshold.
1156506f1d07SSam Ravnborg
11574efc0670SAndi Kleenconfig X86_ANCIENT_MCE
11586fc108a0SJan Beulich	bool "Support for old Pentium 5 / WinChip machine checks"
1159c31d9633SAndi Kleen	depends on X86_32 && X86_MCE
11604efc0670SAndi Kleen	---help---
11614efc0670SAndi Kleen	  Include support for machine check handling on old Pentium 5 or WinChip
11625065a706SMasanari Iida	  systems. These typically need to be enabled explicitly on the command
11634efc0670SAndi Kleen	  line.
11644efc0670SAndi Kleen
1165b2762686SAndi Kleenconfig X86_MCE_THRESHOLD
1166b2762686SAndi Kleen	depends on X86_MCE_AMD || X86_MCE_INTEL
11676fc108a0SJan Beulich	def_bool y
1168b2762686SAndi Kleen
1169ea149b36SAndi Kleenconfig X86_MCE_INJECT
1170bc8e80d5SBorislav Petkov	depends on X86_MCE && X86_LOCAL_APIC && DEBUG_FS
1171ea149b36SAndi Kleen	tristate "Machine check injector support"
1172ea149b36SAndi Kleen	---help---
1173ea149b36SAndi Kleen	  Provide support for injecting machine checks for testing purposes.
1174ea149b36SAndi Kleen	  If you don't know what a machine check is and you don't do kernel
1175ea149b36SAndi Kleen	  QA it is safe to say n.
1176ea149b36SAndi Kleen
11774efc0670SAndi Kleenconfig X86_THERMAL_VECTOR
11784efc0670SAndi Kleen	def_bool y
11795bb38adcSAndi Kleen	depends on X86_MCE_INTEL
11804efc0670SAndi Kleen
118107dc900eSPeter Zijlstrasource "arch/x86/events/Kconfig"
1182e633c65aSKan Liang
11835aef51c3SAndy Lutomirskiconfig X86_LEGACY_VM86
11841e642812SIngo Molnar	bool "Legacy VM86 support"
1185506f1d07SSam Ravnborg	depends on X86_32
11868f9ca475SIngo Molnar	---help---
11875aef51c3SAndy Lutomirski	  This option allows user programs to put the CPU into V8086
11885aef51c3SAndy Lutomirski	  mode, which is an 80286-era approximation of 16-bit real mode.
11895aef51c3SAndy Lutomirski
11905aef51c3SAndy Lutomirski	  Some very old versions of X and/or vbetool require this option
11915aef51c3SAndy Lutomirski	  for user mode setting.  Similarly, DOSEMU will use it if
11925aef51c3SAndy Lutomirski	  available to accelerate real mode DOS programs.  However, any
11935aef51c3SAndy Lutomirski	  recent version of DOSEMU, X, or vbetool should be fully
11945aef51c3SAndy Lutomirski	  functional even without kernel VM86 support, as they will all
11951e642812SIngo Molnar	  fall back to software emulation. Nevertheless, if you are using
11961e642812SIngo Molnar	  a 16-bit DOS program where 16-bit performance matters, vm86
11971e642812SIngo Molnar	  mode might be faster than emulation and you might want to
11981e642812SIngo Molnar	  enable this option.
11995aef51c3SAndy Lutomirski
12001e642812SIngo Molnar	  Note that any app that works on a 64-bit kernel is unlikely to
12011e642812SIngo Molnar	  need this option, as 64-bit kernels don't, and can't, support
12021e642812SIngo Molnar	  V8086 mode. This option is also unrelated to 16-bit protected
12031e642812SIngo Molnar	  mode and is not needed to run most 16-bit programs under Wine.
12045aef51c3SAndy Lutomirski
12051e642812SIngo Molnar	  Enabling this option increases the complexity of the kernel
12061e642812SIngo Molnar	  and slows down exception handling a tiny bit.
12075aef51c3SAndy Lutomirski
12081e642812SIngo Molnar	  If unsure, say N here.
12095aef51c3SAndy Lutomirski
12105aef51c3SAndy Lutomirskiconfig VM86
12115aef51c3SAndy Lutomirski       bool
12125aef51c3SAndy Lutomirski       default X86_LEGACY_VM86
121334273f41SH. Peter Anvin
121434273f41SH. Peter Anvinconfig X86_16BIT
121534273f41SH. Peter Anvin	bool "Enable support for 16-bit segments" if EXPERT
121634273f41SH. Peter Anvin	default y
1217a5b9e5a2SAndy Lutomirski	depends on MODIFY_LDT_SYSCALL
121834273f41SH. Peter Anvin	---help---
121934273f41SH. Peter Anvin	  This option is required by programs like Wine to run 16-bit
122034273f41SH. Peter Anvin	  protected mode legacy code on x86 processors.  Disabling
122134273f41SH. Peter Anvin	  this option saves about 300 bytes on i386, or around 6K text
122234273f41SH. Peter Anvin	  plus 16K runtime memory on x86-64,
122334273f41SH. Peter Anvin
122434273f41SH. Peter Anvinconfig X86_ESPFIX32
122534273f41SH. Peter Anvin	def_bool y
122634273f41SH. Peter Anvin	depends on X86_16BIT && X86_32
1227506f1d07SSam Ravnborg
1228197725deSH. Peter Anvinconfig X86_ESPFIX64
1229197725deSH. Peter Anvin	def_bool y
123034273f41SH. Peter Anvin	depends on X86_16BIT && X86_64
1231506f1d07SSam Ravnborg
12321ad83c85SAndy Lutomirskiconfig X86_VSYSCALL_EMULATION
12331ad83c85SAndy Lutomirski       bool "Enable vsyscall emulation" if EXPERT
12341ad83c85SAndy Lutomirski       default y
12351ad83c85SAndy Lutomirski       depends on X86_64
12361ad83c85SAndy Lutomirski       ---help---
12371ad83c85SAndy Lutomirski	 This enables emulation of the legacy vsyscall page.  Disabling
12381ad83c85SAndy Lutomirski	 it is roughly equivalent to booting with vsyscall=none, except
12391ad83c85SAndy Lutomirski	 that it will also disable the helpful warning if a program
12401ad83c85SAndy Lutomirski	 tries to use a vsyscall.  With this option set to N, offending
12411ad83c85SAndy Lutomirski	 programs will just segfault, citing addresses of the form
12421ad83c85SAndy Lutomirski	 0xffffffffff600?00.
12431ad83c85SAndy Lutomirski
12441ad83c85SAndy Lutomirski	 This option is required by many programs built before 2013, and
12451ad83c85SAndy Lutomirski	 care should be used even with newer programs if set to N.
12461ad83c85SAndy Lutomirski
12471ad83c85SAndy Lutomirski	 Disabling this option saves about 7K of kernel size and
12481ad83c85SAndy Lutomirski	 possibly 4K of additional runtime pagetable memory.
12491ad83c85SAndy Lutomirski
1250506f1d07SSam Ravnborgconfig TOSHIBA
1251506f1d07SSam Ravnborg	tristate "Toshiba Laptop support"
1252506f1d07SSam Ravnborg	depends on X86_32
1253506f1d07SSam Ravnborg	---help---
1254506f1d07SSam Ravnborg	  This adds a driver to safely access the System Management Mode of
1255506f1d07SSam Ravnborg	  the CPU on Toshiba portables with a genuine Toshiba BIOS. It does
1256506f1d07SSam Ravnborg	  not work on models with a Phoenix BIOS. The System Management Mode
1257506f1d07SSam Ravnborg	  is used to set the BIOS and power saving options on Toshiba portables.
1258506f1d07SSam Ravnborg
1259506f1d07SSam Ravnborg	  For information on utilities to make use of this driver see the
1260506f1d07SSam Ravnborg	  Toshiba Linux utilities web site at:
1261506f1d07SSam Ravnborg	  <http://www.buzzard.org.uk/toshiba/>.
1262506f1d07SSam Ravnborg
1263506f1d07SSam Ravnborg	  Say Y if you intend to run this kernel on a Toshiba portable.
1264506f1d07SSam Ravnborg	  Say N otherwise.
1265506f1d07SSam Ravnborg
1266506f1d07SSam Ravnborgconfig I8K
1267039ae585SPali Rohár	tristate "Dell i8k legacy laptop support"
1268949a9d70SJean Delvare	select HWMON
1269039ae585SPali Rohár	select SENSORS_DELL_SMM
1270506f1d07SSam Ravnborg	---help---
1271039ae585SPali Rohár	  This option enables legacy /proc/i8k userspace interface in hwmon
1272039ae585SPali Rohár	  dell-smm-hwmon driver. Character file /proc/i8k reports bios version,
1273039ae585SPali Rohár	  temperature and allows controlling fan speeds of Dell laptops via
1274039ae585SPali Rohár	  System Management Mode. For old Dell laptops (like Dell Inspiron 8000)
1275039ae585SPali Rohár	  it reports also power and hotkey status. For fan speed control is
1276039ae585SPali Rohár	  needed userspace package i8kutils.
1277506f1d07SSam Ravnborg
1278039ae585SPali Rohár	  Say Y if you intend to run this kernel on old Dell laptops or want to
1279039ae585SPali Rohár	  use userspace package i8kutils.
1280506f1d07SSam Ravnborg	  Say N otherwise.
1281506f1d07SSam Ravnborg
1282506f1d07SSam Ravnborgconfig X86_REBOOTFIXUPS
12839ba16087SJan Beulich	bool "Enable X86 board specific fixups for reboot"
12849ba16087SJan Beulich	depends on X86_32
1285506f1d07SSam Ravnborg	---help---
1286506f1d07SSam Ravnborg	  This enables chipset and/or board specific fixups to be done
1287506f1d07SSam Ravnborg	  in order to get reboot to work correctly. This is only needed on
1288506f1d07SSam Ravnborg	  some combinations of hardware and BIOS. The symptom, for which
1289506f1d07SSam Ravnborg	  this config is intended, is when reboot ends with a stalled/hung
1290506f1d07SSam Ravnborg	  system.
1291506f1d07SSam Ravnborg
1292506f1d07SSam Ravnborg	  Currently, the only fixup is for the Geode machines using
12935e3a77e9SFlorian Fainelli	  CS5530A and CS5536 chipsets and the RDC R-321x SoC.
1294506f1d07SSam Ravnborg
1295506f1d07SSam Ravnborg	  Say Y if you want to enable the fixup. Currently, it's safe to
1296506f1d07SSam Ravnborg	  enable this option even if you don't need it.
1297506f1d07SSam Ravnborg	  Say N otherwise.
1298506f1d07SSam Ravnborg
1299506f1d07SSam Ravnborgconfig MICROCODE
13009a2bc335SBorislav Petkov	bool "CPU microcode loading support"
13019a2bc335SBorislav Petkov	default y
130280030e3dSBorislav Petkov	depends on CPU_SUP_AMD || CPU_SUP_INTEL
1303506f1d07SSam Ravnborg	select FW_LOADER
1304506f1d07SSam Ravnborg	---help---
1305506f1d07SSam Ravnborg	  If you say Y here, you will be able to update the microcode on
13065f9c01aaSBorislav Petkov	  Intel and AMD processors. The Intel support is for the IA32 family,
13075f9c01aaSBorislav Petkov	  e.g. Pentium Pro, Pentium II, Pentium III, Pentium 4, Xeon etc. The
13085f9c01aaSBorislav Petkov	  AMD support is for families 0x10 and later. You will obviously need
13095f9c01aaSBorislav Petkov	  the actual microcode binary data itself which is not shipped with
13105f9c01aaSBorislav Petkov	  the Linux kernel.
1311506f1d07SSam Ravnborg
13125f9c01aaSBorislav Petkov	  The preferred method to load microcode from a detached initrd is described
1313cb1aaebeSMauro Carvalho Chehab	  in Documentation/x86/microcode.rst. For that you need to enable
13145f9c01aaSBorislav Petkov	  CONFIG_BLK_DEV_INITRD in order for the loader to be able to scan the
13155f9c01aaSBorislav Petkov	  initrd for microcode blobs.
1316506f1d07SSam Ravnborg
1317c508c46eSBenjamin Gilbert	  In addition, you can build the microcode into the kernel. For that you
1318c508c46eSBenjamin Gilbert	  need to add the vendor-supplied microcode to the CONFIG_EXTRA_FIRMWARE
1319c508c46eSBenjamin Gilbert	  config option.
1320506f1d07SSam Ravnborg
13218d86f390SPeter Orubaconfig MICROCODE_INTEL
1322e43f6e67SBorislav Petkov	bool "Intel microcode loading support"
13238d86f390SPeter Oruba	depends on MICROCODE
13248d86f390SPeter Oruba	default MICROCODE
13258d86f390SPeter Oruba	select FW_LOADER
13268f9ca475SIngo Molnar	---help---
13278d86f390SPeter Oruba	  This options enables microcode patch loading support for Intel
13288d86f390SPeter Oruba	  processors.
13298d86f390SPeter Oruba
1330b8989db9SAlan	  For the current Intel microcode data package go to
1331b8989db9SAlan	  <https://downloadcenter.intel.com> and search for
1332b8989db9SAlan	  'Linux Processor Microcode Data File'.
13338d86f390SPeter Oruba
133480cc9f10SPeter Orubaconfig MICROCODE_AMD
1335e43f6e67SBorislav Petkov	bool "AMD microcode loading support"
133680cc9f10SPeter Oruba	depends on MICROCODE
133780cc9f10SPeter Oruba	select FW_LOADER
13388f9ca475SIngo Molnar	---help---
133980cc9f10SPeter Oruba	  If you select this option, microcode patch loading support for AMD
134080cc9f10SPeter Oruba	  processors will be enabled.
134180cc9f10SPeter Oruba
1342506f1d07SSam Ravnborgconfig MICROCODE_OLD_INTERFACE
1343c02f48e0SBorislav Petkov	bool "Ancient loading interface (DEPRECATED)"
1344c02f48e0SBorislav Petkov	default n
1345506f1d07SSam Ravnborg	depends on MICROCODE
1346c02f48e0SBorislav Petkov	---help---
1347c02f48e0SBorislav Petkov	  DO NOT USE THIS! This is the ancient /dev/cpu/microcode interface
1348c02f48e0SBorislav Petkov	  which was used by userspace tools like iucode_tool and microcode.ctl.
1349c02f48e0SBorislav Petkov	  It is inadequate because it runs too late to be able to properly
1350c02f48e0SBorislav Petkov	  load microcode on a machine and it needs special tools. Instead, you
1351c02f48e0SBorislav Petkov	  should've switched to the early loading method with the initrd or
1352cb1aaebeSMauro Carvalho Chehab	  builtin microcode by now: Documentation/x86/microcode.rst
1353506f1d07SSam Ravnborg
1354506f1d07SSam Ravnborgconfig X86_MSR
1355506f1d07SSam Ravnborg	tristate "/dev/cpu/*/msr - Model-specific register support"
13568f9ca475SIngo Molnar	---help---
1357506f1d07SSam Ravnborg	  This device gives privileged processes access to the x86
1358506f1d07SSam Ravnborg	  Model-Specific Registers (MSRs).  It is a character device with
1359506f1d07SSam Ravnborg	  major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr.
1360506f1d07SSam Ravnborg	  MSR accesses are directed to a specific CPU on multi-processor
1361506f1d07SSam Ravnborg	  systems.
1362506f1d07SSam Ravnborg
1363506f1d07SSam Ravnborgconfig X86_CPUID
1364506f1d07SSam Ravnborg	tristate "/dev/cpu/*/cpuid - CPU information support"
13658f9ca475SIngo Molnar	---help---
1366506f1d07SSam Ravnborg	  This device gives processes access to the x86 CPUID instruction to
1367506f1d07SSam Ravnborg	  be executed on a specific processor.  It is a character device
1368506f1d07SSam Ravnborg	  with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to
1369506f1d07SSam Ravnborg	  /dev/cpu/31/cpuid.
1370506f1d07SSam Ravnborg
1371506f1d07SSam Ravnborgchoice
1372506f1d07SSam Ravnborg	prompt "High Memory Support"
13736fc108a0SJan Beulich	default HIGHMEM4G
1374506f1d07SSam Ravnborg	depends on X86_32
1375506f1d07SSam Ravnborg
1376506f1d07SSam Ravnborgconfig NOHIGHMEM
1377506f1d07SSam Ravnborg	bool "off"
1378506f1d07SSam Ravnborg	---help---
1379506f1d07SSam Ravnborg	  Linux can use up to 64 Gigabytes of physical memory on x86 systems.
1380506f1d07SSam Ravnborg	  However, the address space of 32-bit x86 processors is only 4
1381506f1d07SSam Ravnborg	  Gigabytes large. That means that, if you have a large amount of
1382506f1d07SSam Ravnborg	  physical memory, not all of it can be "permanently mapped" by the
1383506f1d07SSam Ravnborg	  kernel. The physical memory that's not permanently mapped is called
1384506f1d07SSam Ravnborg	  "high memory".
1385506f1d07SSam Ravnborg
1386506f1d07SSam Ravnborg	  If you are compiling a kernel which will never run on a machine with
1387506f1d07SSam Ravnborg	  more than 1 Gigabyte total physical RAM, answer "off" here (default
1388506f1d07SSam Ravnborg	  choice and suitable for most users). This will result in a "3GB/1GB"
1389506f1d07SSam Ravnborg	  split: 3GB are mapped so that each process sees a 3GB virtual memory
1390506f1d07SSam Ravnborg	  space and the remaining part of the 4GB virtual memory space is used
1391506f1d07SSam Ravnborg	  by the kernel to permanently map as much physical memory as
1392506f1d07SSam Ravnborg	  possible.
1393506f1d07SSam Ravnborg
1394506f1d07SSam Ravnborg	  If the machine has between 1 and 4 Gigabytes physical RAM, then
1395506f1d07SSam Ravnborg	  answer "4GB" here.
1396506f1d07SSam Ravnborg
1397506f1d07SSam Ravnborg	  If more than 4 Gigabytes is used then answer "64GB" here. This
1398506f1d07SSam Ravnborg	  selection turns Intel PAE (Physical Address Extension) mode on.
1399506f1d07SSam Ravnborg	  PAE implements 3-level paging on IA32 processors. PAE is fully
1400506f1d07SSam Ravnborg	  supported by Linux, PAE mode is implemented on all recent Intel
1401506f1d07SSam Ravnborg	  processors (Pentium Pro and better). NOTE: If you say "64GB" here,
1402506f1d07SSam Ravnborg	  then the kernel will not boot on CPUs that don't support PAE!
1403506f1d07SSam Ravnborg
1404506f1d07SSam Ravnborg	  The actual amount of total physical memory will either be
1405506f1d07SSam Ravnborg	  auto detected or can be forced by using a kernel command line option
1406506f1d07SSam Ravnborg	  such as "mem=256M". (Try "man bootparam" or see the documentation of
1407506f1d07SSam Ravnborg	  your boot loader (lilo or loadlin) about how to pass options to the
1408506f1d07SSam Ravnborg	  kernel at boot time.)
1409506f1d07SSam Ravnborg
1410506f1d07SSam Ravnborg	  If unsure, say "off".
1411506f1d07SSam Ravnborg
1412506f1d07SSam Ravnborgconfig HIGHMEM4G
1413506f1d07SSam Ravnborg	bool "4GB"
14148f9ca475SIngo Molnar	---help---
1415506f1d07SSam Ravnborg	  Select this if you have a 32-bit processor and between 1 and 4
1416506f1d07SSam Ravnborg	  gigabytes of physical RAM.
1417506f1d07SSam Ravnborg
1418506f1d07SSam Ravnborgconfig HIGHMEM64G
1419506f1d07SSam Ravnborg	bool "64GB"
142069b8d3fcSMatthew Whitehead	depends on !M486 && !M586 && !M586TSC && !M586MMX && !MGEODE_LX && !MGEODEGX1 && !MCYRIXIII && !MELAN && !MWINCHIPC6 && !WINCHIP3D && !MK6
1421506f1d07SSam Ravnborg	select X86_PAE
14228f9ca475SIngo Molnar	---help---
1423506f1d07SSam Ravnborg	  Select this if you have a 32-bit processor and more than 4
1424506f1d07SSam Ravnborg	  gigabytes of physical RAM.
1425506f1d07SSam Ravnborg
1426506f1d07SSam Ravnborgendchoice
1427506f1d07SSam Ravnborg
1428506f1d07SSam Ravnborgchoice
14296a108a14SDavid Rientjes	prompt "Memory split" if EXPERT
1430506f1d07SSam Ravnborg	default VMSPLIT_3G
1431506f1d07SSam Ravnborg	depends on X86_32
14328f9ca475SIngo Molnar	---help---
1433506f1d07SSam Ravnborg	  Select the desired split between kernel and user memory.
1434506f1d07SSam Ravnborg
1435506f1d07SSam Ravnborg	  If the address range available to the kernel is less than the
1436506f1d07SSam Ravnborg	  physical memory installed, the remaining memory will be available
1437506f1d07SSam Ravnborg	  as "high memory". Accessing high memory is a little more costly
1438506f1d07SSam Ravnborg	  than low memory, as it needs to be mapped into the kernel first.
1439506f1d07SSam Ravnborg	  Note that increasing the kernel address space limits the range
1440506f1d07SSam Ravnborg	  available to user programs, making the address space there
1441506f1d07SSam Ravnborg	  tighter.  Selecting anything other than the default 3G/1G split
1442506f1d07SSam Ravnborg	  will also likely make your kernel incompatible with binary-only
1443506f1d07SSam Ravnborg	  kernel modules.
1444506f1d07SSam Ravnborg
1445506f1d07SSam Ravnborg	  If you are not absolutely sure what you are doing, leave this
1446506f1d07SSam Ravnborg	  option alone!
1447506f1d07SSam Ravnborg
1448506f1d07SSam Ravnborg	config VMSPLIT_3G
1449506f1d07SSam Ravnborg		bool "3G/1G user/kernel split"
1450506f1d07SSam Ravnborg	config VMSPLIT_3G_OPT
1451506f1d07SSam Ravnborg		depends on !X86_PAE
1452506f1d07SSam Ravnborg		bool "3G/1G user/kernel split (for full 1G low memory)"
1453506f1d07SSam Ravnborg	config VMSPLIT_2G
1454506f1d07SSam Ravnborg		bool "2G/2G user/kernel split"
1455506f1d07SSam Ravnborg	config VMSPLIT_2G_OPT
1456506f1d07SSam Ravnborg		depends on !X86_PAE
1457506f1d07SSam Ravnborg		bool "2G/2G user/kernel split (for full 2G low memory)"
1458506f1d07SSam Ravnborg	config VMSPLIT_1G
1459506f1d07SSam Ravnborg		bool "1G/3G user/kernel split"
1460506f1d07SSam Ravnborgendchoice
1461506f1d07SSam Ravnborg
1462506f1d07SSam Ravnborgconfig PAGE_OFFSET
1463506f1d07SSam Ravnborg	hex
1464506f1d07SSam Ravnborg	default 0xB0000000 if VMSPLIT_3G_OPT
1465506f1d07SSam Ravnborg	default 0x80000000 if VMSPLIT_2G
1466506f1d07SSam Ravnborg	default 0x78000000 if VMSPLIT_2G_OPT
1467506f1d07SSam Ravnborg	default 0x40000000 if VMSPLIT_1G
1468506f1d07SSam Ravnborg	default 0xC0000000
1469506f1d07SSam Ravnborg	depends on X86_32
1470506f1d07SSam Ravnborg
1471506f1d07SSam Ravnborgconfig HIGHMEM
14723c2362e6SHarvey Harrison	def_bool y
1473506f1d07SSam Ravnborg	depends on X86_32 && (HIGHMEM64G || HIGHMEM4G)
1474506f1d07SSam Ravnborg
1475506f1d07SSam Ravnborgconfig X86_PAE
14769ba16087SJan Beulich	bool "PAE (Physical Address Extension) Support"
1477506f1d07SSam Ravnborg	depends on X86_32 && !HIGHMEM4G
1478d4a451d5SChristoph Hellwig	select PHYS_ADDR_T_64BIT
14799d99c712SChristian Melki	select SWIOTLB
14808f9ca475SIngo Molnar	---help---
1481506f1d07SSam Ravnborg	  PAE is required for NX support, and furthermore enables
1482506f1d07SSam Ravnborg	  larger swapspace support for non-overcommit purposes. It
1483506f1d07SSam Ravnborg	  has the cost of more pagetable lookup overhead, and also
1484506f1d07SSam Ravnborg	  consumes more pagetable space per process.
1485506f1d07SSam Ravnborg
148677ef56e4SKirill A. Shutemovconfig X86_5LEVEL
148777ef56e4SKirill A. Shutemov	bool "Enable 5-level page tables support"
1488eedb92abSKirill A. Shutemov	select DYNAMIC_MEMORY_LAYOUT
1489162434e7SKirill A. Shutemov	select SPARSEMEM_VMEMMAP
149077ef56e4SKirill A. Shutemov	depends on X86_64
149177ef56e4SKirill A. Shutemov	---help---
149277ef56e4SKirill A. Shutemov	  5-level paging enables access to larger address space:
149377ef56e4SKirill A. Shutemov	  upto 128 PiB of virtual address space and 4 PiB of
149477ef56e4SKirill A. Shutemov	  physical address space.
149577ef56e4SKirill A. Shutemov
149677ef56e4SKirill A. Shutemov	  It will be supported by future Intel CPUs.
149777ef56e4SKirill A. Shutemov
14986657fca0SKirill A. Shutemov	  A kernel with the option enabled can be booted on machines that
14996657fca0SKirill A. Shutemov	  support 4- or 5-level paging.
150077ef56e4SKirill A. Shutemov
1501cb1aaebeSMauro Carvalho Chehab	  See Documentation/x86/x86_64/5level-paging.rst for more
150277ef56e4SKirill A. Shutemov	  information.
150377ef56e4SKirill A. Shutemov
150477ef56e4SKirill A. Shutemov	  Say N if unsure.
150577ef56e4SKirill A. Shutemov
150610971ab2SIngo Molnarconfig X86_DIRECT_GBPAGES
1507e5008abeSLuis R. Rodriguez	def_bool y
15084675ff05SLevin, Alexander (Sasha Levin)	depends on X86_64 && !DEBUG_PAGEALLOC
15098f9ca475SIngo Molnar	---help---
151010971ab2SIngo Molnar	  Certain kernel features effectively disable kernel
151110971ab2SIngo Molnar	  linear 1 GB mappings (even if the CPU otherwise
151210971ab2SIngo Molnar	  supports them), so don't confuse the user by printing
151310971ab2SIngo Molnar	  that we have them enabled.
15149e899816SNick Piggin
15155c280cf6SThomas Gleixnerconfig X86_CPA_STATISTICS
15165c280cf6SThomas Gleixner	bool "Enable statistic for Change Page Attribute"
15175c280cf6SThomas Gleixner	depends on DEBUG_FS
15185c280cf6SThomas Gleixner	---help---
15195c280cf6SThomas Gleixner	  Expose statistics about the Change Page Attribute mechanims, which
1520a943245aSColin Ian King	  helps to determine the effectiveness of preserving large and huge
15215c280cf6SThomas Gleixner	  page mappings when mapping protections are changed.
15225c280cf6SThomas Gleixner
15237744ccdbSTom Lendackyconfig ARCH_HAS_MEM_ENCRYPT
15247744ccdbSTom Lendacky	def_bool y
15257744ccdbSTom Lendacky
15267744ccdbSTom Lendackyconfig AMD_MEM_ENCRYPT
15277744ccdbSTom Lendacky	bool "AMD Secure Memory Encryption (SME) support"
15287744ccdbSTom Lendacky	depends on X86_64 && CPU_SUP_AMD
152994d49eb3SKirill A. Shutemov	select DYNAMIC_PHYSICAL_MASK
1530ce9084baSArd Biesheuvel	select ARCH_USE_MEMREMAP_PROT
1531*9087c375STom Lendacky	select ARCH_HAS_FORCE_DMA_UNENCRYPTED
15327744ccdbSTom Lendacky	---help---
15337744ccdbSTom Lendacky	  Say yes to enable support for the encryption of system memory.
15347744ccdbSTom Lendacky	  This requires an AMD processor that supports Secure Memory
15357744ccdbSTom Lendacky	  Encryption (SME).
15367744ccdbSTom Lendacky
15377744ccdbSTom Lendackyconfig AMD_MEM_ENCRYPT_ACTIVE_BY_DEFAULT
15387744ccdbSTom Lendacky	bool "Activate AMD Secure Memory Encryption (SME) by default"
15397744ccdbSTom Lendacky	default y
15407744ccdbSTom Lendacky	depends on AMD_MEM_ENCRYPT
15417744ccdbSTom Lendacky	---help---
15427744ccdbSTom Lendacky	  Say yes to have system memory encrypted by default if running on
15437744ccdbSTom Lendacky	  an AMD processor that supports Secure Memory Encryption (SME).
15447744ccdbSTom Lendacky
15457744ccdbSTom Lendacky	  If set to Y, then the encryption of system memory can be
15467744ccdbSTom Lendacky	  deactivated with the mem_encrypt=off command line option.
15477744ccdbSTom Lendacky
15487744ccdbSTom Lendacky	  If set to N, then the encryption of system memory can be
15497744ccdbSTom Lendacky	  activated with the mem_encrypt=on command line option.
15507744ccdbSTom Lendacky
1551506f1d07SSam Ravnborg# Common NUMA Features
1552506f1d07SSam Ravnborgconfig NUMA
1553fd51b2d7SKOSAKI Motohiro	bool "Numa Memory Allocation and Scheduler Support"
1554506f1d07SSam Ravnborg	depends on SMP
1555b5660ba7SH. Peter Anvin	depends on X86_64 || (X86_32 && HIGHMEM64G && X86_BIGSMP)
1556b5660ba7SH. Peter Anvin	default y if X86_BIGSMP
15578f9ca475SIngo Molnar	---help---
1558506f1d07SSam Ravnborg	  Enable NUMA (Non Uniform Memory Access) support.
1559fd51b2d7SKOSAKI Motohiro
1560506f1d07SSam Ravnborg	  The kernel will try to allocate memory used by a CPU on the
1561506f1d07SSam Ravnborg	  local memory controller of the CPU and add some more
1562506f1d07SSam Ravnborg	  NUMA awareness to the kernel.
1563506f1d07SSam Ravnborg
1564c280ea5eSIngo Molnar	  For 64-bit this is recommended if the system is Intel Core i7
1565fd51b2d7SKOSAKI Motohiro	  (or later), AMD Opteron, or EM64T NUMA.
1566fd51b2d7SKOSAKI Motohiro
1567b5660ba7SH. Peter Anvin	  For 32-bit this is only needed if you boot a 32-bit
15687cf6c945SDavid Rientjes	  kernel on a 64-bit NUMA platform.
1569fd51b2d7SKOSAKI Motohiro
1570fd51b2d7SKOSAKI Motohiro	  Otherwise, you should say N.
1571506f1d07SSam Ravnborg
1572eec1d4faSHans Rosenfeldconfig AMD_NUMA
15733c2362e6SHarvey Harrison	def_bool y
15743c2362e6SHarvey Harrison	prompt "Old style AMD Opteron NUMA detection"
15755da0ef9aSTejun Heo	depends on X86_64 && NUMA && PCI
15768f9ca475SIngo Molnar	---help---
1577eec1d4faSHans Rosenfeld	  Enable AMD NUMA node topology detection.  You should say Y here if
1578eec1d4faSHans Rosenfeld	  you have a multi processor AMD system. This uses an old method to
1579eec1d4faSHans Rosenfeld	  read the NUMA configuration directly from the builtin Northbridge
1580eec1d4faSHans Rosenfeld	  of Opteron. It is recommended to use X86_64_ACPI_NUMA instead,
1581eec1d4faSHans Rosenfeld	  which also takes priority if both are compiled in.
1582506f1d07SSam Ravnborg
1583506f1d07SSam Ravnborgconfig X86_64_ACPI_NUMA
15843c2362e6SHarvey Harrison	def_bool y
15853c2362e6SHarvey Harrison	prompt "ACPI NUMA detection"
1586506f1d07SSam Ravnborg	depends on X86_64 && NUMA && ACPI && PCI
1587506f1d07SSam Ravnborg	select ACPI_NUMA
15888f9ca475SIngo Molnar	---help---
1589506f1d07SSam Ravnborg	  Enable ACPI SRAT based node topology detection.
1590506f1d07SSam Ravnborg
15916ec6e0d9SSuresh Siddha# Some NUMA nodes have memory ranges that span
15926ec6e0d9SSuresh Siddha# other nodes.  Even though a pfn is valid and
15936ec6e0d9SSuresh Siddha# between a node's start and end pfns, it may not
15946ec6e0d9SSuresh Siddha# reside on that node.  See memmap_init_zone()
15956ec6e0d9SSuresh Siddha# for details.
15966ec6e0d9SSuresh Siddhaconfig NODES_SPAN_OTHER_NODES
15976ec6e0d9SSuresh Siddha	def_bool y
15986ec6e0d9SSuresh Siddha	depends on X86_64_ACPI_NUMA
15996ec6e0d9SSuresh Siddha
1600506f1d07SSam Ravnborgconfig NUMA_EMU
1601506f1d07SSam Ravnborg	bool "NUMA emulation"
16021b7e03efSTejun Heo	depends on NUMA
16038f9ca475SIngo Molnar	---help---
1604506f1d07SSam Ravnborg	  Enable NUMA emulation. A flat machine will be split
1605506f1d07SSam Ravnborg	  into virtual nodes when booted with "numa=fake=N", where N is the
1606506f1d07SSam Ravnborg	  number of nodes. This is only useful for debugging.
1607506f1d07SSam Ravnborg
1608506f1d07SSam Ravnborgconfig NODES_SHIFT
1609d25e26b6SLinus Torvalds	int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP
161051591e31SDavid Rientjes	range 1 10
161151591e31SDavid Rientjes	default "10" if MAXSMP
1612506f1d07SSam Ravnborg	default "6" if X86_64
1613506f1d07SSam Ravnborg	default "3"
1614506f1d07SSam Ravnborg	depends on NEED_MULTIPLE_NODES
16158f9ca475SIngo Molnar	---help---
16161184dc2fSMike Travis	  Specify the maximum number of NUMA Nodes available on the target
1617692105b8SMatt LaPlante	  system.  Increases memory reserved to accommodate various tables.
1618506f1d07SSam Ravnborg
1619506f1d07SSam Ravnborgconfig ARCH_HAVE_MEMORY_PRESENT
16203c2362e6SHarvey Harrison	def_bool y
1621506f1d07SSam Ravnborg	depends on X86_32 && DISCONTIGMEM
1622506f1d07SSam Ravnborg
1623506f1d07SSam Ravnborgconfig ARCH_FLATMEM_ENABLE
1624506f1d07SSam Ravnborg	def_bool y
16253b16651fSTejun Heo	depends on X86_32 && !NUMA
1626506f1d07SSam Ravnborg
1627506f1d07SSam Ravnborgconfig ARCH_DISCONTIGMEM_ENABLE
16282792107dSMike Rapoport	def_bool n
1629b263295dSChristoph Lameter	depends on NUMA && X86_32
16302792107dSMike Rapoport	depends on BROKEN
1631b263295dSChristoph Lameter
1632506f1d07SSam Ravnborgconfig ARCH_SPARSEMEM_ENABLE
1633506f1d07SSam Ravnborg	def_bool y
16346ea30386SKees Cook	depends on X86_64 || NUMA || X86_32 || X86_32_NON_STANDARD
1635506f1d07SSam Ravnborg	select SPARSEMEM_STATIC if X86_32
1636506f1d07SSam Ravnborg	select SPARSEMEM_VMEMMAP_ENABLE if X86_64
1637506f1d07SSam Ravnborg
16383b16651fSTejun Heoconfig ARCH_SPARSEMEM_DEFAULT
16396ad57f7fSMike Rapoport	def_bool X86_64 || (NUMA && X86_32)
16403b16651fSTejun Heo
1641506f1d07SSam Ravnborgconfig ARCH_SELECT_MEMORY_MODEL
1642506f1d07SSam Ravnborg	def_bool y
1643b263295dSChristoph Lameter	depends on ARCH_SPARSEMEM_ENABLE
1644506f1d07SSam Ravnborg
1645506f1d07SSam Ravnborgconfig ARCH_MEMORY_PROBE
1646a0842b70SToshi Kani	bool "Enable sysfs memory/probe interface"
16473120e25eSJan Beulich	depends on X86_64 && MEMORY_HOTPLUG
1648a0842b70SToshi Kani	help
1649a0842b70SToshi Kani	  This option enables a sysfs memory/probe interface for testing.
1650cb1aaebeSMauro Carvalho Chehab	  See Documentation/admin-guide/mm/memory-hotplug.rst for more information.
1651a0842b70SToshi Kani	  If you are unsure how to answer this question, answer N.
1652506f1d07SSam Ravnborg
16533b16651fSTejun Heoconfig ARCH_PROC_KCORE_TEXT
16543b16651fSTejun Heo	def_bool y
16553b16651fSTejun Heo	depends on X86_64 && PROC_KCORE
16563b16651fSTejun Heo
1657a29815a3SAvi Kivityconfig ILLEGAL_POINTER_VALUE
1658a29815a3SAvi Kivity       hex
1659a29815a3SAvi Kivity       default 0 if X86_32
1660a29815a3SAvi Kivity       default 0xdead000000000000 if X86_64
1661a29815a3SAvi Kivity
16627a67832cSDan Williamsconfig X86_PMEM_LEGACY_DEVICE
16637a67832cSDan Williams	bool
16647a67832cSDan Williams
1665ec776ef6SChristoph Hellwigconfig X86_PMEM_LEGACY
16667a67832cSDan Williams	tristate "Support non-standard NVDIMMs and ADR protected memory"
16679f53f9faSDan Williams	depends on PHYS_ADDR_T_64BIT
16689f53f9faSDan Williams	depends on BLK_DEV
16697a67832cSDan Williams	select X86_PMEM_LEGACY_DEVICE
16709f53f9faSDan Williams	select LIBNVDIMM
1671ec776ef6SChristoph Hellwig	help
1672ec776ef6SChristoph Hellwig	  Treat memory marked using the non-standard e820 type of 12 as used
1673ec776ef6SChristoph Hellwig	  by the Intel Sandy Bridge-EP reference BIOS as protected memory.
1674ec776ef6SChristoph Hellwig	  The kernel will offer these regions to the 'pmem' driver so
1675ec776ef6SChristoph Hellwig	  they can be used for persistent storage.
1676ec776ef6SChristoph Hellwig
1677ec776ef6SChristoph Hellwig	  Say Y if unsure.
1678ec776ef6SChristoph Hellwig
1679506f1d07SSam Ravnborgconfig HIGHPTE
1680506f1d07SSam Ravnborg	bool "Allocate 3rd-level pagetables from highmem"
16816fc108a0SJan Beulich	depends on HIGHMEM
16828f9ca475SIngo Molnar	---help---
1683506f1d07SSam Ravnborg	  The VM uses one page table entry for each page of physical memory.
1684506f1d07SSam Ravnborg	  For systems with a lot of RAM, this can be wasteful of precious
1685506f1d07SSam Ravnborg	  low memory.  Setting this option will put user-space page table
1686506f1d07SSam Ravnborg	  entries in high memory.
1687506f1d07SSam Ravnborg
16889f077871SJeremy Fitzhardingeconfig X86_CHECK_BIOS_CORRUPTION
16899f077871SJeremy Fitzhardinge	bool "Check for low memory corruption"
16908f9ca475SIngo Molnar	---help---
16919f077871SJeremy Fitzhardinge	  Periodically check for memory corruption in low memory, which
16929f077871SJeremy Fitzhardinge	  is suspected to be caused by BIOS.  Even when enabled in the
16939f077871SJeremy Fitzhardinge	  configuration, it is disabled at runtime.  Enable it by
16949f077871SJeremy Fitzhardinge	  setting "memory_corruption_check=1" on the kernel command
16959f077871SJeremy Fitzhardinge	  line.  By default it scans the low 64k of memory every 60
16969f077871SJeremy Fitzhardinge	  seconds; see the memory_corruption_check_size and
16979f077871SJeremy Fitzhardinge	  memory_corruption_check_period parameters in
16988c27ceffSMauro Carvalho Chehab	  Documentation/admin-guide/kernel-parameters.rst to adjust this.
16999f077871SJeremy Fitzhardinge
17009f077871SJeremy Fitzhardinge	  When enabled with the default parameters, this option has
17019f077871SJeremy Fitzhardinge	  almost no overhead, as it reserves a relatively small amount
17029f077871SJeremy Fitzhardinge	  of memory and scans it infrequently.  It both detects corruption
17039f077871SJeremy Fitzhardinge	  and prevents it from affecting the running system.
17049f077871SJeremy Fitzhardinge
17059f077871SJeremy Fitzhardinge	  It is, however, intended as a diagnostic tool; if repeatable
17069f077871SJeremy Fitzhardinge	  BIOS-originated corruption always affects the same memory,
17079f077871SJeremy Fitzhardinge	  you can use memmap= to prevent the kernel from using that
17089f077871SJeremy Fitzhardinge	  memory.
17099f077871SJeremy Fitzhardinge
1710c885df50SJeremy Fitzhardingeconfig X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK
1711c885df50SJeremy Fitzhardinge	bool "Set the default setting of memory_corruption_check"
1712c885df50SJeremy Fitzhardinge	depends on X86_CHECK_BIOS_CORRUPTION
1713c885df50SJeremy Fitzhardinge	default y
17148f9ca475SIngo Molnar	---help---
1715c885df50SJeremy Fitzhardinge	  Set whether the default state of memory_corruption_check is
1716c885df50SJeremy Fitzhardinge	  on or off.
1717c885df50SJeremy Fitzhardinge
17189ea77bdbSH. Peter Anvinconfig X86_RESERVE_LOW
1719d0cd7425SH. Peter Anvin	int "Amount of low memory, in kilobytes, to reserve for the BIOS"
1720d0cd7425SH. Peter Anvin	default 64
1721d0cd7425SH. Peter Anvin	range 4 640
17228f9ca475SIngo Molnar	---help---
1723d0cd7425SH. Peter Anvin	  Specify the amount of low memory to reserve for the BIOS.
1724fc381519SIngo Molnar
1725d0cd7425SH. Peter Anvin	  The first page contains BIOS data structures that the kernel
1726d0cd7425SH. Peter Anvin	  must not use, so that page must always be reserved.
1727fc381519SIngo Molnar
1728d0cd7425SH. Peter Anvin	  By default we reserve the first 64K of physical RAM, as a
1729d0cd7425SH. Peter Anvin	  number of BIOSes are known to corrupt that memory range
1730d0cd7425SH. Peter Anvin	  during events such as suspend/resume or monitor cable
1731d0cd7425SH. Peter Anvin	  insertion, so it must not be used by the kernel.
1732fc381519SIngo Molnar
1733d0cd7425SH. Peter Anvin	  You can set this to 4 if you are absolutely sure that you
1734d0cd7425SH. Peter Anvin	  trust the BIOS to get all its memory reservations and usages
1735d0cd7425SH. Peter Anvin	  right.  If you know your BIOS have problems beyond the
1736d0cd7425SH. Peter Anvin	  default 64K area, you can set this to 640 to avoid using the
1737d0cd7425SH. Peter Anvin	  entire low memory range.
1738d0cd7425SH. Peter Anvin
1739d0cd7425SH. Peter Anvin	  If you have doubts about the BIOS (e.g. suspend/resume does
1740d0cd7425SH. Peter Anvin	  not work or there's kernel crashes after certain hardware
1741d0cd7425SH. Peter Anvin	  hotplug events) then you might want to enable
1742d0cd7425SH. Peter Anvin	  X86_CHECK_BIOS_CORRUPTION=y to allow the kernel to check
1743d0cd7425SH. Peter Anvin	  typical corruption patterns.
1744d0cd7425SH. Peter Anvin
1745d0cd7425SH. Peter Anvin	  Leave this to the default value of 64 if you are unsure.
1746fc381519SIngo Molnar
1747506f1d07SSam Ravnborgconfig MATH_EMULATION
1748506f1d07SSam Ravnborg	bool
1749a5b9e5a2SAndy Lutomirski	depends on MODIFY_LDT_SYSCALL
1750506f1d07SSam Ravnborg	prompt "Math emulation" if X86_32
1751506f1d07SSam Ravnborg	---help---
1752506f1d07SSam Ravnborg	  Linux can emulate a math coprocessor (used for floating point
1753506f1d07SSam Ravnborg	  operations) if you don't have one. 486DX and Pentium processors have
1754506f1d07SSam Ravnborg	  a math coprocessor built in, 486SX and 386 do not, unless you added
1755506f1d07SSam Ravnborg	  a 487DX or 387, respectively. (The messages during boot time can
1756506f1d07SSam Ravnborg	  give you some hints here ["man dmesg"].) Everyone needs either a
1757506f1d07SSam Ravnborg	  coprocessor or this emulation.
1758506f1d07SSam Ravnborg
1759506f1d07SSam Ravnborg	  If you don't have a math coprocessor, you need to say Y here; if you
1760506f1d07SSam Ravnborg	  say Y here even though you have a coprocessor, the coprocessor will
1761506f1d07SSam Ravnborg	  be used nevertheless. (This behavior can be changed with the kernel
1762506f1d07SSam Ravnborg	  command line option "no387", which comes handy if your coprocessor
1763506f1d07SSam Ravnborg	  is broken. Try "man bootparam" or see the documentation of your boot
1764506f1d07SSam Ravnborg	  loader (lilo or loadlin) about how to pass options to the kernel at
1765506f1d07SSam Ravnborg	  boot time.) This means that it is a good idea to say Y here if you
1766506f1d07SSam Ravnborg	  intend to use this kernel on different machines.
1767506f1d07SSam Ravnborg
1768506f1d07SSam Ravnborg	  More information about the internals of the Linux math coprocessor
1769506f1d07SSam Ravnborg	  emulation can be found in <file:arch/x86/math-emu/README>.
1770506f1d07SSam Ravnborg
1771506f1d07SSam Ravnborg	  If you are not sure, say Y; apart from resulting in a 66 KB bigger
1772506f1d07SSam Ravnborg	  kernel, it won't hurt.
1773506f1d07SSam Ravnborg
1774506f1d07SSam Ravnborgconfig MTRR
17756fc108a0SJan Beulich	def_bool y
17766a108a14SDavid Rientjes	prompt "MTRR (Memory Type Range Register) support" if EXPERT
1777506f1d07SSam Ravnborg	---help---
1778506f1d07SSam Ravnborg	  On Intel P6 family processors (Pentium Pro, Pentium II and later)
1779506f1d07SSam Ravnborg	  the Memory Type Range Registers (MTRRs) may be used to control
1780506f1d07SSam Ravnborg	  processor access to memory ranges. This is most useful if you have
1781506f1d07SSam Ravnborg	  a video (VGA) card on a PCI or AGP bus. Enabling write-combining
1782506f1d07SSam Ravnborg	  allows bus write transfers to be combined into a larger transfer
1783506f1d07SSam Ravnborg	  before bursting over the PCI/AGP bus. This can increase performance
1784506f1d07SSam Ravnborg	  of image write operations 2.5 times or more. Saying Y here creates a
1785506f1d07SSam Ravnborg	  /proc/mtrr file which may be used to manipulate your processor's
1786506f1d07SSam Ravnborg	  MTRRs. Typically the X server should use this.
1787506f1d07SSam Ravnborg
1788506f1d07SSam Ravnborg	  This code has a reasonably generic interface so that similar
1789506f1d07SSam Ravnborg	  control registers on other processors can be easily supported
1790506f1d07SSam Ravnborg	  as well:
1791506f1d07SSam Ravnborg
1792506f1d07SSam Ravnborg	  The Cyrix 6x86, 6x86MX and M II processors have Address Range
1793506f1d07SSam Ravnborg	  Registers (ARRs) which provide a similar functionality to MTRRs. For
1794506f1d07SSam Ravnborg	  these, the ARRs are used to emulate the MTRRs.
1795506f1d07SSam Ravnborg	  The AMD K6-2 (stepping 8 and above) and K6-3 processors have two
1796506f1d07SSam Ravnborg	  MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing
1797506f1d07SSam Ravnborg	  write-combining. All of these processors are supported by this code
1798506f1d07SSam Ravnborg	  and it makes sense to say Y here if you have one of them.
1799506f1d07SSam Ravnborg
1800506f1d07SSam Ravnborg	  Saying Y here also fixes a problem with buggy SMP BIOSes which only
1801506f1d07SSam Ravnborg	  set the MTRRs for the boot CPU and not for the secondary CPUs. This
1802506f1d07SSam Ravnborg	  can lead to all sorts of problems, so it's good to say Y here.
1803506f1d07SSam Ravnborg
1804506f1d07SSam Ravnborg	  You can safely say Y even if your machine doesn't have MTRRs, you'll
1805506f1d07SSam Ravnborg	  just add about 9 KB to your kernel.
1806506f1d07SSam Ravnborg
1807cb1aaebeSMauro Carvalho Chehab	  See <file:Documentation/x86/mtrr.rst> for more information.
1808506f1d07SSam Ravnborg
180995ffa243SYinghai Luconfig MTRR_SANITIZER
18102ffb3501SYinghai Lu	def_bool y
181195ffa243SYinghai Lu	prompt "MTRR cleanup support"
181295ffa243SYinghai Lu	depends on MTRR
18138f9ca475SIngo Molnar	---help---
1814aba3728cSThomas Gleixner	  Convert MTRR layout from continuous to discrete, so X drivers can
1815aba3728cSThomas Gleixner	  add writeback entries.
181695ffa243SYinghai Lu
1817aba3728cSThomas Gleixner	  Can be disabled with disable_mtrr_cleanup on the kernel command line.
1818692105b8SMatt LaPlante	  The largest mtrr entry size for a continuous block can be set with
1819aba3728cSThomas Gleixner	  mtrr_chunk_size.
182095ffa243SYinghai Lu
18212ffb3501SYinghai Lu	  If unsure, say Y.
182295ffa243SYinghai Lu
182395ffa243SYinghai Luconfig MTRR_SANITIZER_ENABLE_DEFAULT
1824f5098d62SYinghai Lu	int "MTRR cleanup enable value (0-1)"
1825f5098d62SYinghai Lu	range 0 1
1826f5098d62SYinghai Lu	default "0"
182795ffa243SYinghai Lu	depends on MTRR_SANITIZER
18288f9ca475SIngo Molnar	---help---
1829f5098d62SYinghai Lu	  Enable mtrr cleanup default value
183095ffa243SYinghai Lu
183112031a62SYinghai Luconfig MTRR_SANITIZER_SPARE_REG_NR_DEFAULT
183212031a62SYinghai Lu	int "MTRR cleanup spare reg num (0-7)"
183312031a62SYinghai Lu	range 0 7
183412031a62SYinghai Lu	default "1"
183512031a62SYinghai Lu	depends on MTRR_SANITIZER
18368f9ca475SIngo Molnar	---help---
183712031a62SYinghai Lu	  mtrr cleanup spare entries default, it can be changed via
1838aba3728cSThomas Gleixner	  mtrr_spare_reg_nr=N on the kernel command line.
183912031a62SYinghai Lu
18402e5d9c85Svenkatesh.pallipadi@intel.comconfig X86_PAT
18416fc108a0SJan Beulich	def_bool y
18426a108a14SDavid Rientjes	prompt "x86 PAT support" if EXPERT
18432a8a2719SIngo Molnar	depends on MTRR
18448f9ca475SIngo Molnar	---help---
18452e5d9c85Svenkatesh.pallipadi@intel.com	  Use PAT attributes to setup page level cache control.
1846042b78e4SVenki Pallipadi
18472e5d9c85Svenkatesh.pallipadi@intel.com	  PATs are the modern equivalents of MTRRs and are much more
18482e5d9c85Svenkatesh.pallipadi@intel.com	  flexible than MTRRs.
18492e5d9c85Svenkatesh.pallipadi@intel.com
18502e5d9c85Svenkatesh.pallipadi@intel.com	  Say N here if you see bootup problems (boot crash, boot hang,
1851042b78e4SVenki Pallipadi	  spontaneous reboots) or a non-working video driver.
18522e5d9c85Svenkatesh.pallipadi@intel.com
18532e5d9c85Svenkatesh.pallipadi@intel.com	  If unsure, say Y.
18542e5d9c85Svenkatesh.pallipadi@intel.com
185546cf98cdSVenkatesh Pallipadiconfig ARCH_USES_PG_UNCACHED
185646cf98cdSVenkatesh Pallipadi	def_bool y
185746cf98cdSVenkatesh Pallipadi	depends on X86_PAT
185846cf98cdSVenkatesh Pallipadi
1859628c6246SH. Peter Anvinconfig ARCH_RANDOM
1860628c6246SH. Peter Anvin	def_bool y
1861628c6246SH. Peter Anvin	prompt "x86 architectural random number generator" if EXPERT
1862628c6246SH. Peter Anvin	---help---
1863628c6246SH. Peter Anvin	  Enable the x86 architectural RDRAND instruction
1864628c6246SH. Peter Anvin	  (Intel Bull Mountain technology) to generate random numbers.
1865628c6246SH. Peter Anvin	  If supported, this is a high bandwidth, cryptographically
1866628c6246SH. Peter Anvin	  secure hardware random number generator.
1867628c6246SH. Peter Anvin
186851ae4a2dSH. Peter Anvinconfig X86_SMAP
186951ae4a2dSH. Peter Anvin	def_bool y
187051ae4a2dSH. Peter Anvin	prompt "Supervisor Mode Access Prevention" if EXPERT
187151ae4a2dSH. Peter Anvin	---help---
187251ae4a2dSH. Peter Anvin	  Supervisor Mode Access Prevention (SMAP) is a security
187351ae4a2dSH. Peter Anvin	  feature in newer Intel processors.  There is a small
187451ae4a2dSH. Peter Anvin	  performance cost if this enabled and turned on; there is
187551ae4a2dSH. Peter Anvin	  also a small increase in the kernel size if this is enabled.
187651ae4a2dSH. Peter Anvin
187751ae4a2dSH. Peter Anvin	  If unsure, say Y.
187851ae4a2dSH. Peter Anvin
1879aa35f896SRicardo Nericonfig X86_INTEL_UMIP
1880796ebc81SRicardo Neri	def_bool y
1881aa35f896SRicardo Neri	depends on CPU_SUP_INTEL
1882aa35f896SRicardo Neri	prompt "Intel User Mode Instruction Prevention" if EXPERT
1883aa35f896SRicardo Neri	---help---
1884aa35f896SRicardo Neri	  The User Mode Instruction Prevention (UMIP) is a security
1885aa35f896SRicardo Neri	  feature in newer Intel processors. If enabled, a general
1886796ebc81SRicardo Neri	  protection fault is issued if the SGDT, SLDT, SIDT, SMSW
1887796ebc81SRicardo Neri	  or STR instructions are executed in user mode. These instructions
1888796ebc81SRicardo Neri	  unnecessarily expose information about the hardware state.
1889796ebc81SRicardo Neri
1890796ebc81SRicardo Neri	  The vast majority of applications do not use these instructions.
1891796ebc81SRicardo Neri	  For the very few that do, software emulation is provided in
1892796ebc81SRicardo Neri	  specific cases in protected and virtual-8086 modes. Emulated
1893796ebc81SRicardo Neri	  results are dummy.
1894aa35f896SRicardo Neri
189572e9b5feSDave Hansenconfig X86_INTEL_MPX
189672e9b5feSDave Hansen	prompt "Intel MPX (Memory Protection Extensions)"
189772e9b5feSDave Hansen	def_bool n
1898df3735c5SRik van Riel	# Note: only available in 64-bit mode due to VMA flags shortage
1899df3735c5SRik van Riel	depends on CPU_SUP_INTEL && X86_64
1900df3735c5SRik van Riel	select ARCH_USES_HIGH_VMA_FLAGS
190172e9b5feSDave Hansen	---help---
190272e9b5feSDave Hansen	  MPX provides hardware features that can be used in
190372e9b5feSDave Hansen	  conjunction with compiler-instrumented code to check
190472e9b5feSDave Hansen	  memory references.  It is designed to detect buffer
190572e9b5feSDave Hansen	  overflow or underflow bugs.
190672e9b5feSDave Hansen
190772e9b5feSDave Hansen	  This option enables running applications which are
190872e9b5feSDave Hansen	  instrumented or otherwise use MPX.  It does not use MPX
190972e9b5feSDave Hansen	  itself inside the kernel or to protect the kernel
191072e9b5feSDave Hansen	  against bad memory references.
191172e9b5feSDave Hansen
191272e9b5feSDave Hansen	  Enabling this option will make the kernel larger:
191372e9b5feSDave Hansen	  ~8k of kernel text and 36 bytes of data on a 64-bit
191472e9b5feSDave Hansen	  defconfig.  It adds a long to the 'mm_struct' which
191572e9b5feSDave Hansen	  will increase the kernel memory overhead of each
191672e9b5feSDave Hansen	  process and adds some branches to paths used during
191772e9b5feSDave Hansen	  exec() and munmap().
191872e9b5feSDave Hansen
1919cb1aaebeSMauro Carvalho Chehab	  For details, see Documentation/x86/intel_mpx.rst
192072e9b5feSDave Hansen
192172e9b5feSDave Hansen	  If unsure, say N.
192272e9b5feSDave Hansen
192335e97790SDave Hansenconfig X86_INTEL_MEMORY_PROTECTION_KEYS
1924284244a9SDave Hansen	prompt "Intel Memory Protection Keys"
192535e97790SDave Hansen	def_bool y
1926284244a9SDave Hansen	# Note: only available in 64-bit mode
192735e97790SDave Hansen	depends on CPU_SUP_INTEL && X86_64
192852c8e601SIngo Molnar	select ARCH_USES_HIGH_VMA_FLAGS
192952c8e601SIngo Molnar	select ARCH_HAS_PKEYS
1930284244a9SDave Hansen	---help---
1931284244a9SDave Hansen	  Memory Protection Keys provides a mechanism for enforcing
1932284244a9SDave Hansen	  page-based protections, but without requiring modification of the
1933284244a9SDave Hansen	  page tables when an application changes protection domains.
1934284244a9SDave Hansen
19351eecbcdcSMauro Carvalho Chehab	  For details, see Documentation/core-api/protection-keys.rst
1936284244a9SDave Hansen
1937284244a9SDave Hansen	  If unsure, say y.
193835e97790SDave Hansen
1939506f1d07SSam Ravnborgconfig EFI
19409ba16087SJan Beulich	bool "EFI runtime service support"
19415b83683fSHuang, Ying	depends on ACPI
1942f6ce5002SSergey Vlasov	select UCS2_STRING
1943022ee6c5SArd Biesheuvel	select EFI_RUNTIME_WRAPPERS
1944506f1d07SSam Ravnborg	---help---
19458b2cb7a8SHuang, Ying	  This enables the kernel to use EFI runtime services that are
1946506f1d07SSam Ravnborg	  available (such as the EFI variable services).
1947506f1d07SSam Ravnborg
19488b2cb7a8SHuang, Ying	  This option is only useful on systems that have EFI firmware.
19498b2cb7a8SHuang, Ying	  In addition, you should use the latest ELILO loader available
19508b2cb7a8SHuang, Ying	  at <http://elilo.sourceforge.net> in order to take advantage
19518b2cb7a8SHuang, Ying	  of EFI runtime services. However, even with this option, the
19528b2cb7a8SHuang, Ying	  resultant kernel should continue to boot on existing non-EFI
19538b2cb7a8SHuang, Ying	  platforms.
1954506f1d07SSam Ravnborg
1955291f3632SMatt Flemingconfig EFI_STUB
1956291f3632SMatt Fleming       bool "EFI stub support"
1957b16d8c23SMatt Fleming       depends on EFI && !X86_USE_3DNOW
19587b2a583aSMatt Fleming       select RELOCATABLE
1959291f3632SMatt Fleming       ---help---
1960291f3632SMatt Fleming          This kernel feature allows a bzImage to be loaded directly
1961291f3632SMatt Fleming	  by EFI firmware without the use of a bootloader.
1962291f3632SMatt Fleming
19634172fe2fSRoy Franz	  See Documentation/efi-stub.txt for more information.
19640c759662SMatt Fleming
19657d453eeeSMatt Flemingconfig EFI_MIXED
19667d453eeeSMatt Fleming	bool "EFI mixed-mode support"
19677d453eeeSMatt Fleming	depends on EFI_STUB && X86_64
19687d453eeeSMatt Fleming	---help---
19697d453eeeSMatt Fleming	   Enabling this feature allows a 64-bit kernel to be booted
19707d453eeeSMatt Fleming	   on a 32-bit firmware, provided that your CPU supports 64-bit
19717d453eeeSMatt Fleming	   mode.
19727d453eeeSMatt Fleming
19737d453eeeSMatt Fleming	   Note that it is not possible to boot a mixed-mode enabled
19747d453eeeSMatt Fleming	   kernel via the EFI boot stub - a bootloader that supports
19757d453eeeSMatt Fleming	   the EFI handover protocol must be used.
19767d453eeeSMatt Fleming
19777d453eeeSMatt Fleming	   If unsure, say N.
19787d453eeeSMatt Fleming
1979506f1d07SSam Ravnborgconfig SECCOMP
19803c2362e6SHarvey Harrison	def_bool y
19813c2362e6SHarvey Harrison	prompt "Enable seccomp to safely compute untrusted bytecode"
19828f9ca475SIngo Molnar	---help---
1983506f1d07SSam Ravnborg	  This kernel feature is useful for number crunching applications
1984506f1d07SSam Ravnborg	  that may need to compute untrusted bytecode during their
1985506f1d07SSam Ravnborg	  execution. By using pipes or other transports made available to
1986506f1d07SSam Ravnborg	  the process as file descriptors supporting the read/write
1987506f1d07SSam Ravnborg	  syscalls, it's possible to isolate those applications in
1988506f1d07SSam Ravnborg	  their own address space using seccomp. Once seccomp is
19899c0bbee8SAlexey Dobriyan	  enabled via prctl(PR_SET_SECCOMP), it cannot be disabled
1990506f1d07SSam Ravnborg	  and the task is only allowed to execute a few safe syscalls
1991506f1d07SSam Ravnborg	  defined by each seccomp mode.
1992506f1d07SSam Ravnborg
1993506f1d07SSam Ravnborg	  If unsure, say Y. Only embedded should say N here.
1994506f1d07SSam Ravnborg
19958636a1f9SMasahiro Yamadasource "kernel/Kconfig.hz"
1996506f1d07SSam Ravnborg
1997506f1d07SSam Ravnborgconfig KEXEC
1998506f1d07SSam Ravnborg	bool "kexec system call"
19992965faa5SDave Young	select KEXEC_CORE
20008f9ca475SIngo Molnar	---help---
2001506f1d07SSam Ravnborg	  kexec is a system call that implements the ability to shutdown your
2002506f1d07SSam Ravnborg	  current kernel, and to start another kernel.  It is like a reboot
2003506f1d07SSam Ravnborg	  but it is independent of the system firmware.   And like a reboot
2004506f1d07SSam Ravnborg	  you can start any kernel with it, not just Linux.
2005506f1d07SSam Ravnborg
2006506f1d07SSam Ravnborg	  The name comes from the similarity to the exec system call.
2007506f1d07SSam Ravnborg
2008506f1d07SSam Ravnborg	  It is an ongoing process to be certain the hardware in a machine
2009506f1d07SSam Ravnborg	  is properly shutdown, so do not be surprised if this code does not
2010bf220695SGeert Uytterhoeven	  initially work for you.  As of this writing the exact hardware
2011bf220695SGeert Uytterhoeven	  interface is strongly in flux, so no good recommendation can be
2012bf220695SGeert Uytterhoeven	  made.
2013506f1d07SSam Ravnborg
201474ca317cSVivek Goyalconfig KEXEC_FILE
201574ca317cSVivek Goyal	bool "kexec file based system call"
20162965faa5SDave Young	select KEXEC_CORE
201774ca317cSVivek Goyal	select BUILD_BIN2C
201874ca317cSVivek Goyal	depends on X86_64
201974ca317cSVivek Goyal	depends on CRYPTO=y
202074ca317cSVivek Goyal	depends on CRYPTO_SHA256=y
202174ca317cSVivek Goyal	---help---
202274ca317cSVivek Goyal	  This is new version of kexec system call. This system call is
202374ca317cSVivek Goyal	  file based and takes file descriptors as system call argument
202474ca317cSVivek Goyal	  for kernel and initramfs as opposed to list of segments as
202574ca317cSVivek Goyal	  accepted by previous system call.
202674ca317cSVivek Goyal
2027b799a09fSAKASHI Takahiroconfig ARCH_HAS_KEXEC_PURGATORY
2028b799a09fSAKASHI Takahiro	def_bool KEXEC_FILE
2029b799a09fSAKASHI Takahiro
20308e7d8381SVivek Goyalconfig KEXEC_VERIFY_SIG
20318e7d8381SVivek Goyal	bool "Verify kernel signature during kexec_file_load() syscall"
203274ca317cSVivek Goyal	depends on KEXEC_FILE
20338e7d8381SVivek Goyal	---help---
20348e7d8381SVivek Goyal	  This option makes kernel signature verification mandatory for
2035d8eb8940SBorislav Petkov	  the kexec_file_load() syscall.
20368e7d8381SVivek Goyal
2037d8eb8940SBorislav Petkov	  In addition to that option, you need to enable signature
2038d8eb8940SBorislav Petkov	  verification for the corresponding kernel image type being
2039d8eb8940SBorislav Petkov	  loaded in order for this to work.
20408e7d8381SVivek Goyal
20418e7d8381SVivek Goyalconfig KEXEC_BZIMAGE_VERIFY_SIG
20428e7d8381SVivek Goyal	bool "Enable bzImage signature verification support"
20438e7d8381SVivek Goyal	depends on KEXEC_VERIFY_SIG
20448e7d8381SVivek Goyal	depends on SIGNED_PE_FILE_VERIFICATION
20458e7d8381SVivek Goyal	select SYSTEM_TRUSTED_KEYRING
20468e7d8381SVivek Goyal	---help---
20478e7d8381SVivek Goyal	  Enable bzImage signature verification support.
20488e7d8381SVivek Goyal
2049506f1d07SSam Ravnborgconfig CRASH_DUMP
205004b69447SPavel Machek	bool "kernel crash dumps"
2051506f1d07SSam Ravnborg	depends on X86_64 || (X86_32 && HIGHMEM)
20528f9ca475SIngo Molnar	---help---
2053506f1d07SSam Ravnborg	  Generate crash dump after being started by kexec.
2054506f1d07SSam Ravnborg	  This should be normally only set in special crash dump kernels
2055506f1d07SSam Ravnborg	  which are loaded in the main kernel with kexec-tools into
2056506f1d07SSam Ravnborg	  a specially reserved region and then later executed after
2057506f1d07SSam Ravnborg	  a crash by kdump/kexec. The crash dump kernel must be compiled
2058506f1d07SSam Ravnborg	  to a memory address not used by the main kernel or BIOS using
2059506f1d07SSam Ravnborg	  PHYSICAL_START, or it must be built as a relocatable image
2060506f1d07SSam Ravnborg	  (CONFIG_RELOCATABLE=y).
2061d67297adSMauro Carvalho Chehab	  For more details see Documentation/kdump/kdump.rst
2062506f1d07SSam Ravnborg
20633ab83521SHuang Yingconfig KEXEC_JUMP
20646ea30386SKees Cook	bool "kexec jump"
2065fee7b0d8SHuang Ying	depends on KEXEC && HIBERNATION
20668f9ca475SIngo Molnar	---help---
206789081d17SHuang Ying	  Jump between original kernel and kexeced kernel and invoke
206889081d17SHuang Ying	  code in physical address mode via KEXEC
20693ab83521SHuang Ying
2070506f1d07SSam Ravnborgconfig PHYSICAL_START
20716a108a14SDavid Rientjes	hex "Physical address where the kernel is loaded" if (EXPERT || CRASH_DUMP)
2072ceefccc9SH. Peter Anvin	default "0x1000000"
20738f9ca475SIngo Molnar	---help---
2074506f1d07SSam Ravnborg	  This gives the physical address where the kernel is loaded.
2075506f1d07SSam Ravnborg
2076506f1d07SSam Ravnborg	  If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then
2077506f1d07SSam Ravnborg	  bzImage will decompress itself to above physical address and
2078506f1d07SSam Ravnborg	  run from there. Otherwise, bzImage will run from the address where
2079506f1d07SSam Ravnborg	  it has been loaded by the boot loader and will ignore above physical
2080506f1d07SSam Ravnborg	  address.
2081506f1d07SSam Ravnborg
2082506f1d07SSam Ravnborg	  In normal kdump cases one does not have to set/change this option
2083506f1d07SSam Ravnborg	  as now bzImage can be compiled as a completely relocatable image
2084506f1d07SSam Ravnborg	  (CONFIG_RELOCATABLE=y) and be used to load and run from a different
2085506f1d07SSam Ravnborg	  address. This option is mainly useful for the folks who don't want
2086506f1d07SSam Ravnborg	  to use a bzImage for capturing the crash dump and want to use a
2087506f1d07SSam Ravnborg	  vmlinux instead. vmlinux is not relocatable hence a kernel needs
2088506f1d07SSam Ravnborg	  to be specifically compiled to run from a specific memory area
2089506f1d07SSam Ravnborg	  (normally a reserved region) and this option comes handy.
2090506f1d07SSam Ravnborg
2091ceefccc9SH. Peter Anvin	  So if you are using bzImage for capturing the crash dump,
2092ceefccc9SH. Peter Anvin	  leave the value here unchanged to 0x1000000 and set
2093ceefccc9SH. Peter Anvin	  CONFIG_RELOCATABLE=y.  Otherwise if you plan to use vmlinux
2094ceefccc9SH. Peter Anvin	  for capturing the crash dump change this value to start of
2095ceefccc9SH. Peter Anvin	  the reserved region.  In other words, it can be set based on
2096ceefccc9SH. Peter Anvin	  the "X" value as specified in the "crashkernel=YM@XM"
2097ceefccc9SH. Peter Anvin	  command line boot parameter passed to the panic-ed
2098d67297adSMauro Carvalho Chehab	  kernel. Please take a look at Documentation/kdump/kdump.rst
2099ceefccc9SH. Peter Anvin	  for more details about crash dumps.
2100506f1d07SSam Ravnborg
2101506f1d07SSam Ravnborg	  Usage of bzImage for capturing the crash dump is recommended as
2102506f1d07SSam Ravnborg	  one does not have to build two kernels. Same kernel can be used
2103506f1d07SSam Ravnborg	  as production kernel and capture kernel. Above option should have
2104506f1d07SSam Ravnborg	  gone away after relocatable bzImage support is introduced. But it
2105506f1d07SSam Ravnborg	  is present because there are users out there who continue to use
2106506f1d07SSam Ravnborg	  vmlinux for dump capture. This option should go away down the
2107506f1d07SSam Ravnborg	  line.
2108506f1d07SSam Ravnborg
2109506f1d07SSam Ravnborg	  Don't change this unless you know what you are doing.
2110506f1d07SSam Ravnborg
2111506f1d07SSam Ravnborgconfig RELOCATABLE
211226717808SH. Peter Anvin	bool "Build a relocatable kernel"
211326717808SH. Peter Anvin	default y
21148f9ca475SIngo Molnar	---help---
2115506f1d07SSam Ravnborg	  This builds a kernel image that retains relocation information
2116506f1d07SSam Ravnborg	  so it can be loaded someplace besides the default 1MB.
2117506f1d07SSam Ravnborg	  The relocations tend to make the kernel binary about 10% larger,
2118506f1d07SSam Ravnborg	  but are discarded at runtime.
2119506f1d07SSam Ravnborg
2120506f1d07SSam Ravnborg	  One use is for the kexec on panic case where the recovery kernel
2121506f1d07SSam Ravnborg	  must live at a different physical address than the primary
2122506f1d07SSam Ravnborg	  kernel.
2123506f1d07SSam Ravnborg
2124506f1d07SSam Ravnborg	  Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address
2125506f1d07SSam Ravnborg	  it has been loaded at and the compile time physical address
21268ab3820fSKees Cook	  (CONFIG_PHYSICAL_START) is used as the minimum location.
2127506f1d07SSam Ravnborg
21288ab3820fSKees Cookconfig RANDOMIZE_BASE
2129e8581e3dSBaoquan He	bool "Randomize the address of the kernel image (KASLR)"
21308ab3820fSKees Cook	depends on RELOCATABLE
21316807c846SIngo Molnar	default y
21328ab3820fSKees Cook	---help---
2133e8581e3dSBaoquan He	  In support of Kernel Address Space Layout Randomization (KASLR),
2134e8581e3dSBaoquan He	  this randomizes the physical address at which the kernel image
2135e8581e3dSBaoquan He	  is decompressed and the virtual address where the kernel
2136e8581e3dSBaoquan He	  image is mapped, as a security feature that deters exploit
2137e8581e3dSBaoquan He	  attempts relying on knowledge of the location of kernel
2138e8581e3dSBaoquan He	  code internals.
2139e8581e3dSBaoquan He
2140ed9f007eSKees Cook	  On 64-bit, the kernel physical and virtual addresses are
2141ed9f007eSKees Cook	  randomized separately. The physical address will be anywhere
2142ed9f007eSKees Cook	  between 16MB and the top of physical memory (up to 64TB). The
2143ed9f007eSKees Cook	  virtual address will be randomized from 16MB up to 1GB (9 bits
2144ed9f007eSKees Cook	  of entropy). Note that this also reduces the memory space
2145ed9f007eSKees Cook	  available to kernel modules from 1.5GB to 1GB.
2146ed9f007eSKees Cook
2147ed9f007eSKees Cook	  On 32-bit, the kernel physical and virtual addresses are
2148ed9f007eSKees Cook	  randomized together. They will be randomized from 16MB up to
2149ed9f007eSKees Cook	  512MB (8 bits of entropy).
21508ab3820fSKees Cook
2151a653f356SKees Cook	  Entropy is generated using the RDRAND instruction if it is
2152e8581e3dSBaoquan He	  supported. If RDTSC is supported, its value is mixed into
2153e8581e3dSBaoquan He	  the entropy pool as well. If neither RDRAND nor RDTSC are
2154ed9f007eSKees Cook	  supported, then entropy is read from the i8254 timer. The
2155ed9f007eSKees Cook	  usable entropy is limited by the kernel being built using
2156ed9f007eSKees Cook	  2GB addressing, and that PHYSICAL_ALIGN must be at a
2157ed9f007eSKees Cook	  minimum of 2MB. As a result, only 10 bits of entropy are
2158ed9f007eSKees Cook	  theoretically possible, but the implementations are further
2159ed9f007eSKees Cook	  limited due to memory layouts.
2160e8581e3dSBaoquan He
21616807c846SIngo Molnar	  If unsure, say Y.
2162da2b6fb9SKees Cook
21638ab3820fSKees Cook# Relocation on x86 needs some additional build support
2164845adf72SH. Peter Anvinconfig X86_NEED_RELOCS
2165845adf72SH. Peter Anvin	def_bool y
21668ab3820fSKees Cook	depends on RANDOMIZE_BASE || (X86_32 && RELOCATABLE)
2167845adf72SH. Peter Anvin
2168506f1d07SSam Ravnborgconfig PHYSICAL_ALIGN
2169a0215061SKees Cook	hex "Alignment value to which kernel should be aligned"
21708ab3820fSKees Cook	default "0x200000"
2171a0215061SKees Cook	range 0x2000 0x1000000 if X86_32
2172a0215061SKees Cook	range 0x200000 0x1000000 if X86_64
21738f9ca475SIngo Molnar	---help---
2174506f1d07SSam Ravnborg	  This value puts the alignment restrictions on physical address
2175506f1d07SSam Ravnborg	  where kernel is loaded and run from. Kernel is compiled for an
2176506f1d07SSam Ravnborg	  address which meets above alignment restriction.
2177506f1d07SSam Ravnborg
2178506f1d07SSam Ravnborg	  If bootloader loads the kernel at a non-aligned address and
2179506f1d07SSam Ravnborg	  CONFIG_RELOCATABLE is set, kernel will move itself to nearest
2180506f1d07SSam Ravnborg	  address aligned to above value and run from there.
2181506f1d07SSam Ravnborg
2182506f1d07SSam Ravnborg	  If bootloader loads the kernel at a non-aligned address and
2183506f1d07SSam Ravnborg	  CONFIG_RELOCATABLE is not set, kernel will ignore the run time
2184506f1d07SSam Ravnborg	  load address and decompress itself to the address it has been
2185506f1d07SSam Ravnborg	  compiled for and run from there. The address for which kernel is
2186506f1d07SSam Ravnborg	  compiled already meets above alignment restrictions. Hence the
2187506f1d07SSam Ravnborg	  end result is that kernel runs from a physical address meeting
2188506f1d07SSam Ravnborg	  above alignment restrictions.
2189506f1d07SSam Ravnborg
2190a0215061SKees Cook	  On 32-bit this value must be a multiple of 0x2000. On 64-bit
2191a0215061SKees Cook	  this value must be a multiple of 0x200000.
2192a0215061SKees Cook
2193506f1d07SSam Ravnborg	  Don't change this unless you know what you are doing.
2194506f1d07SSam Ravnborg
2195eedb92abSKirill A. Shutemovconfig DYNAMIC_MEMORY_LAYOUT
2196eedb92abSKirill A. Shutemov	bool
2197eedb92abSKirill A. Shutemov	---help---
2198eedb92abSKirill A. Shutemov	  This option makes base addresses of vmalloc and vmemmap as well as
2199eedb92abSKirill A. Shutemov	  __PAGE_OFFSET movable during boot.
2200eedb92abSKirill A. Shutemov
22010483e1faSThomas Garnierconfig RANDOMIZE_MEMORY
22020483e1faSThomas Garnier	bool "Randomize the kernel memory sections"
22030483e1faSThomas Garnier	depends on X86_64
22040483e1faSThomas Garnier	depends on RANDOMIZE_BASE
2205eedb92abSKirill A. Shutemov	select DYNAMIC_MEMORY_LAYOUT
22060483e1faSThomas Garnier	default RANDOMIZE_BASE
22070483e1faSThomas Garnier	---help---
22080483e1faSThomas Garnier	   Randomizes the base virtual address of kernel memory sections
22090483e1faSThomas Garnier	   (physical memory mapping, vmalloc & vmemmap). This security feature
22100483e1faSThomas Garnier	   makes exploits relying on predictable memory locations less reliable.
22110483e1faSThomas Garnier
22120483e1faSThomas Garnier	   The order of allocations remains unchanged. Entropy is generated in
22130483e1faSThomas Garnier	   the same way as RANDOMIZE_BASE. Current implementation in the optimal
22140483e1faSThomas Garnier	   configuration have in average 30,000 different possible virtual
22150483e1faSThomas Garnier	   addresses for each memory section.
22160483e1faSThomas Garnier
22176807c846SIngo Molnar	   If unsure, say Y.
22180483e1faSThomas Garnier
221990397a41SThomas Garnierconfig RANDOMIZE_MEMORY_PHYSICAL_PADDING
222090397a41SThomas Garnier	hex "Physical memory mapping padding" if EXPERT
222190397a41SThomas Garnier	depends on RANDOMIZE_MEMORY
222290397a41SThomas Garnier	default "0xa" if MEMORY_HOTPLUG
222390397a41SThomas Garnier	default "0x0"
222490397a41SThomas Garnier	range 0x1 0x40 if MEMORY_HOTPLUG
222590397a41SThomas Garnier	range 0x0 0x40
222690397a41SThomas Garnier	---help---
222790397a41SThomas Garnier	   Define the padding in terabytes added to the existing physical
222890397a41SThomas Garnier	   memory size during kernel memory randomization. It is useful
222990397a41SThomas Garnier	   for memory hotplug support but reduces the entropy available for
223090397a41SThomas Garnier	   address randomization.
223190397a41SThomas Garnier
223290397a41SThomas Garnier	   If unsure, leave at the default value.
223390397a41SThomas Garnier
2234506f1d07SSam Ravnborgconfig HOTPLUG_CPU
2235bebd024eSThomas Gleixner	def_bool y
223640b31360SStephen Rothwell	depends on SMP
2237506f1d07SSam Ravnborg
223880aa1dffSFenghua Yuconfig BOOTPARAM_HOTPLUG_CPU0
223980aa1dffSFenghua Yu	bool "Set default setting of cpu0_hotpluggable"
22402c922cd0SKees Cook	depends on HOTPLUG_CPU
224180aa1dffSFenghua Yu	---help---
224280aa1dffSFenghua Yu	  Set whether default state of cpu0_hotpluggable is on or off.
224380aa1dffSFenghua Yu
224480aa1dffSFenghua Yu	  Say Y here to enable CPU0 hotplug by default. If this switch
224580aa1dffSFenghua Yu	  is turned on, there is no need to give cpu0_hotplug kernel
224680aa1dffSFenghua Yu	  parameter and the CPU0 hotplug feature is enabled by default.
224780aa1dffSFenghua Yu
224880aa1dffSFenghua Yu	  Please note: there are two known CPU0 dependencies if you want
224980aa1dffSFenghua Yu	  to enable the CPU0 hotplug feature either by this switch or by
225080aa1dffSFenghua Yu	  cpu0_hotplug kernel parameter.
225180aa1dffSFenghua Yu
225280aa1dffSFenghua Yu	  First, resume from hibernate or suspend always starts from CPU0.
225380aa1dffSFenghua Yu	  So hibernate and suspend are prevented if CPU0 is offline.
225480aa1dffSFenghua Yu
225580aa1dffSFenghua Yu	  Second dependency is PIC interrupts always go to CPU0. CPU0 can not
225680aa1dffSFenghua Yu	  offline if any interrupt can not migrate out of CPU0. There may
225780aa1dffSFenghua Yu	  be other CPU0 dependencies.
225880aa1dffSFenghua Yu
225980aa1dffSFenghua Yu	  Please make sure the dependencies are under your control before
226080aa1dffSFenghua Yu	  you enable this feature.
226180aa1dffSFenghua Yu
226280aa1dffSFenghua Yu	  Say N if you don't want to enable CPU0 hotplug feature by default.
226380aa1dffSFenghua Yu	  You still can enable the CPU0 hotplug feature at boot by kernel
226480aa1dffSFenghua Yu	  parameter cpu0_hotplug.
226580aa1dffSFenghua Yu
2266a71c8bc5SFenghua Yuconfig DEBUG_HOTPLUG_CPU0
2267a71c8bc5SFenghua Yu	def_bool n
2268a71c8bc5SFenghua Yu	prompt "Debug CPU0 hotplug"
22692c922cd0SKees Cook	depends on HOTPLUG_CPU
2270a71c8bc5SFenghua Yu	---help---
2271a71c8bc5SFenghua Yu	  Enabling this option offlines CPU0 (if CPU0 can be offlined) as
2272a71c8bc5SFenghua Yu	  soon as possible and boots up userspace with CPU0 offlined. User
2273a71c8bc5SFenghua Yu	  can online CPU0 back after boot time.
2274a71c8bc5SFenghua Yu
2275a71c8bc5SFenghua Yu	  To debug CPU0 hotplug, you need to enable CPU0 offline/online
2276a71c8bc5SFenghua Yu	  feature by either turning on CONFIG_BOOTPARAM_HOTPLUG_CPU0 during
2277a71c8bc5SFenghua Yu	  compilation or giving cpu0_hotplug kernel parameter at boot.
2278a71c8bc5SFenghua Yu
2279a71c8bc5SFenghua Yu	  If unsure, say N.
2280a71c8bc5SFenghua Yu
2281506f1d07SSam Ravnborgconfig COMPAT_VDSO
2282b0b49f26SAndy Lutomirski	def_bool n
2283b0b49f26SAndy Lutomirski	prompt "Disable the 32-bit vDSO (needed for glibc 2.3.3)"
2284953fee1dSIngo Molnar	depends on COMPAT_32
22858f9ca475SIngo Molnar	---help---
2286b0b49f26SAndy Lutomirski	  Certain buggy versions of glibc will crash if they are
2287b0b49f26SAndy Lutomirski	  presented with a 32-bit vDSO that is not mapped at the address
2288b0b49f26SAndy Lutomirski	  indicated in its segment table.
2289e84446deSRandy Dunlap
2290b0b49f26SAndy Lutomirski	  The bug was introduced by f866314b89d56845f55e6f365e18b31ec978ec3a
2291b0b49f26SAndy Lutomirski	  and fixed by 3b3ddb4f7db98ec9e912ccdf54d35df4aa30e04a and
2292b0b49f26SAndy Lutomirski	  49ad572a70b8aeb91e57483a11dd1b77e31c4468.  Glibc 2.3.3 is
2293b0b49f26SAndy Lutomirski	  the only released version with the bug, but OpenSUSE 9
2294b0b49f26SAndy Lutomirski	  contains a buggy "glibc 2.3.2".
2295506f1d07SSam Ravnborg
2296b0b49f26SAndy Lutomirski	  The symptom of the bug is that everything crashes on startup, saying:
2297b0b49f26SAndy Lutomirski	  dl_main: Assertion `(void *) ph->p_vaddr == _rtld_local._dl_sysinfo_dso' failed!
2298b0b49f26SAndy Lutomirski
2299b0b49f26SAndy Lutomirski	  Saying Y here changes the default value of the vdso32 boot
2300b0b49f26SAndy Lutomirski	  option from 1 to 0, which turns off the 32-bit vDSO entirely.
2301b0b49f26SAndy Lutomirski	  This works around the glibc bug but hurts performance.
2302b0b49f26SAndy Lutomirski
2303b0b49f26SAndy Lutomirski	  If unsure, say N: if you are compiling your own kernel, you
2304b0b49f26SAndy Lutomirski	  are unlikely to be using a buggy version of glibc.
2305506f1d07SSam Ravnborg
23063dc33bd3SKees Cookchoice
23073dc33bd3SKees Cook	prompt "vsyscall table for legacy applications"
23083dc33bd3SKees Cook	depends on X86_64
2309625b7b7fSAndy Lutomirski	default LEGACY_VSYSCALL_XONLY
23103dc33bd3SKees Cook	help
23113dc33bd3SKees Cook	  Legacy user code that does not know how to find the vDSO expects
23123dc33bd3SKees Cook	  to be able to issue three syscalls by calling fixed addresses in
23133dc33bd3SKees Cook	  kernel space. Since this location is not randomized with ASLR,
23143dc33bd3SKees Cook	  it can be used to assist security vulnerability exploitation.
23153dc33bd3SKees Cook
23163dc33bd3SKees Cook	  This setting can be changed at boot time via the kernel command
2317bd49e16eSAndy Lutomirski	  line parameter vsyscall=[emulate|xonly|none].
23183dc33bd3SKees Cook
23193dc33bd3SKees Cook	  On a system with recent enough glibc (2.14 or newer) and no
23203dc33bd3SKees Cook	  static binaries, you can say None without a performance penalty
23213dc33bd3SKees Cook	  to improve security.
23223dc33bd3SKees Cook
2323bd49e16eSAndy Lutomirski	  If unsure, select "Emulate execution only".
23243dc33bd3SKees Cook
23253dc33bd3SKees Cook	config LEGACY_VSYSCALL_EMULATE
2326bd49e16eSAndy Lutomirski		bool "Full emulation"
23273dc33bd3SKees Cook		help
2328bd49e16eSAndy Lutomirski		  The kernel traps and emulates calls into the fixed vsyscall
2329bd49e16eSAndy Lutomirski		  address mapping. This makes the mapping non-executable, but
2330bd49e16eSAndy Lutomirski		  it still contains readable known contents, which could be
2331bd49e16eSAndy Lutomirski		  used in certain rare security vulnerability exploits. This
2332bd49e16eSAndy Lutomirski		  configuration is recommended when using legacy userspace
2333bd49e16eSAndy Lutomirski		  that still uses vsyscalls along with legacy binary
2334bd49e16eSAndy Lutomirski		  instrumentation tools that require code to be readable.
2335bd49e16eSAndy Lutomirski
2336bd49e16eSAndy Lutomirski		  An example of this type of legacy userspace is running
2337bd49e16eSAndy Lutomirski		  Pin on an old binary that still uses vsyscalls.
2338bd49e16eSAndy Lutomirski
2339bd49e16eSAndy Lutomirski	config LEGACY_VSYSCALL_XONLY
2340bd49e16eSAndy Lutomirski		bool "Emulate execution only"
2341bd49e16eSAndy Lutomirski		help
2342bd49e16eSAndy Lutomirski		  The kernel traps and emulates calls into the fixed vsyscall
2343bd49e16eSAndy Lutomirski		  address mapping and does not allow reads.  This
2344bd49e16eSAndy Lutomirski		  configuration is recommended when userspace might use the
2345bd49e16eSAndy Lutomirski		  legacy vsyscall area but support for legacy binary
2346bd49e16eSAndy Lutomirski		  instrumentation of legacy code is not needed.  It mitigates
2347bd49e16eSAndy Lutomirski		  certain uses of the vsyscall area as an ASLR-bypassing
2348bd49e16eSAndy Lutomirski		  buffer.
23493dc33bd3SKees Cook
23503dc33bd3SKees Cook	config LEGACY_VSYSCALL_NONE
23513dc33bd3SKees Cook		bool "None"
23523dc33bd3SKees Cook		help
23533dc33bd3SKees Cook		  There will be no vsyscall mapping at all. This will
23543dc33bd3SKees Cook		  eliminate any risk of ASLR bypass due to the vsyscall
23553dc33bd3SKees Cook		  fixed address mapping. Attempts to use the vsyscalls
23563dc33bd3SKees Cook		  will be reported to dmesg, so that either old or
23573dc33bd3SKees Cook		  malicious userspace programs can be identified.
23583dc33bd3SKees Cook
23593dc33bd3SKees Cookendchoice
23603dc33bd3SKees Cook
2361516cbf37STim Birdconfig CMDLINE_BOOL
2362516cbf37STim Bird	bool "Built-in kernel command line"
23638f9ca475SIngo Molnar	---help---
2364516cbf37STim Bird	  Allow for specifying boot arguments to the kernel at
2365516cbf37STim Bird	  build time.  On some systems (e.g. embedded ones), it is
2366516cbf37STim Bird	  necessary or convenient to provide some or all of the
2367516cbf37STim Bird	  kernel boot arguments with the kernel itself (that is,
2368516cbf37STim Bird	  to not rely on the boot loader to provide them.)
2369516cbf37STim Bird
2370516cbf37STim Bird	  To compile command line arguments into the kernel,
2371516cbf37STim Bird	  set this option to 'Y', then fill in the
237269711ca1SSébastien Hinderer	  boot arguments in CONFIG_CMDLINE.
2373516cbf37STim Bird
2374516cbf37STim Bird	  Systems with fully functional boot loaders (i.e. non-embedded)
2375516cbf37STim Bird	  should leave this option set to 'N'.
2376516cbf37STim Bird
2377516cbf37STim Birdconfig CMDLINE
2378516cbf37STim Bird	string "Built-in kernel command string"
2379516cbf37STim Bird	depends on CMDLINE_BOOL
2380516cbf37STim Bird	default ""
23818f9ca475SIngo Molnar	---help---
2382516cbf37STim Bird	  Enter arguments here that should be compiled into the kernel
2383516cbf37STim Bird	  image and used at boot time.  If the boot loader provides a
2384516cbf37STim Bird	  command line at boot time, it is appended to this string to
2385516cbf37STim Bird	  form the full kernel command line, when the system boots.
2386516cbf37STim Bird
2387516cbf37STim Bird	  However, you can use the CONFIG_CMDLINE_OVERRIDE option to
2388516cbf37STim Bird	  change this behavior.
2389516cbf37STim Bird
2390516cbf37STim Bird	  In most cases, the command line (whether built-in or provided
2391516cbf37STim Bird	  by the boot loader) should specify the device for the root
2392516cbf37STim Bird	  file system.
2393516cbf37STim Bird
2394516cbf37STim Birdconfig CMDLINE_OVERRIDE
2395516cbf37STim Bird	bool "Built-in command line overrides boot loader arguments"
2396516cbf37STim Bird	depends on CMDLINE_BOOL
23978f9ca475SIngo Molnar	---help---
2398516cbf37STim Bird	  Set this option to 'Y' to have the kernel ignore the boot loader
2399516cbf37STim Bird	  command line, and use ONLY the built-in command line.
2400516cbf37STim Bird
2401516cbf37STim Bird	  This is used to work around broken boot loaders.  This should
2402516cbf37STim Bird	  be set to 'N' under normal conditions.
2403516cbf37STim Bird
2404a5b9e5a2SAndy Lutomirskiconfig MODIFY_LDT_SYSCALL
2405a5b9e5a2SAndy Lutomirski	bool "Enable the LDT (local descriptor table)" if EXPERT
2406a5b9e5a2SAndy Lutomirski	default y
2407a5b9e5a2SAndy Lutomirski	---help---
2408a5b9e5a2SAndy Lutomirski	  Linux can allow user programs to install a per-process x86
2409a5b9e5a2SAndy Lutomirski	  Local Descriptor Table (LDT) using the modify_ldt(2) system
2410a5b9e5a2SAndy Lutomirski	  call.  This is required to run 16-bit or segmented code such as
2411a5b9e5a2SAndy Lutomirski	  DOSEMU or some Wine programs.  It is also used by some very old
2412a5b9e5a2SAndy Lutomirski	  threading libraries.
2413a5b9e5a2SAndy Lutomirski
2414a5b9e5a2SAndy Lutomirski	  Enabling this feature adds a small amount of overhead to
2415a5b9e5a2SAndy Lutomirski	  context switches and increases the low-level kernel attack
2416a5b9e5a2SAndy Lutomirski	  surface.  Disabling it removes the modify_ldt(2) system call.
2417a5b9e5a2SAndy Lutomirski
2418a5b9e5a2SAndy Lutomirski	  Saying 'N' here may make sense for embedded or server kernels.
2419a5b9e5a2SAndy Lutomirski
2420b700e7f0SSeth Jenningssource "kernel/livepatch/Kconfig"
2421b700e7f0SSeth Jennings
2422506f1d07SSam Ravnborgendmenu
2423506f1d07SSam Ravnborg
24243072e413SMichal Hockoconfig ARCH_HAS_ADD_PAGES
24253072e413SMichal Hocko	def_bool y
24263072e413SMichal Hocko	depends on X86_64 && ARCH_ENABLE_MEMORY_HOTPLUG
24273072e413SMichal Hocko
2428506f1d07SSam Ravnborgconfig ARCH_ENABLE_MEMORY_HOTPLUG
2429506f1d07SSam Ravnborg	def_bool y
2430506f1d07SSam Ravnborg	depends on X86_64 || (X86_32 && HIGHMEM)
2431506f1d07SSam Ravnborg
243235551053SGary Hadeconfig ARCH_ENABLE_MEMORY_HOTREMOVE
243335551053SGary Hade	def_bool y
243435551053SGary Hade	depends on MEMORY_HOTPLUG
243535551053SGary Hade
2436e534c7c5SLee Schermerhornconfig USE_PERCPU_NUMA_NODE_ID
2437645a7919STejun Heo	def_bool y
2438e534c7c5SLee Schermerhorn	depends on NUMA
2439e534c7c5SLee Schermerhorn
24409491846fSKirill A. Shutemovconfig ARCH_ENABLE_SPLIT_PMD_PTLOCK
24419491846fSKirill A. Shutemov	def_bool y
24429491846fSKirill A. Shutemov	depends on X86_64 || X86_PAE
24439491846fSKirill A. Shutemov
2444c177c81eSNaoya Horiguchiconfig ARCH_ENABLE_HUGEPAGE_MIGRATION
2445c177c81eSNaoya Horiguchi	def_bool y
2446c177c81eSNaoya Horiguchi	depends on X86_64 && HUGETLB_PAGE && MIGRATION
2447c177c81eSNaoya Horiguchi
24489c670ea3SNaoya Horiguchiconfig ARCH_ENABLE_THP_MIGRATION
24499c670ea3SNaoya Horiguchi	def_bool y
24509c670ea3SNaoya Horiguchi	depends on X86_64 && TRANSPARENT_HUGEPAGE
24519c670ea3SNaoya Horiguchi
2452da85f865SBjorn Helgaasmenu "Power management and ACPI options"
2453e279b6c1SSam Ravnborg
2454e279b6c1SSam Ravnborgconfig ARCH_HIBERNATION_HEADER
24553c2362e6SHarvey Harrison	def_bool y
245644556530SZhimin Gu	depends on HIBERNATION
2457e279b6c1SSam Ravnborg
2458e279b6c1SSam Ravnborgsource "kernel/power/Kconfig"
2459e279b6c1SSam Ravnborg
2460e279b6c1SSam Ravnborgsource "drivers/acpi/Kconfig"
2461e279b6c1SSam Ravnborg
2462efafc8b2SFeng Tangsource "drivers/sfi/Kconfig"
2463efafc8b2SFeng Tang
2464a6b68076SAndi Kleenconfig X86_APM_BOOT
24656fc108a0SJan Beulich	def_bool y
2466282e5aabSPaul Bolle	depends on APM
2467a6b68076SAndi Kleen
2468e279b6c1SSam Ravnborgmenuconfig APM
2469e279b6c1SSam Ravnborg	tristate "APM (Advanced Power Management) BIOS support"
2470efefa6f6SIngo Molnar	depends on X86_32 && PM_SLEEP
2471e279b6c1SSam Ravnborg	---help---
2472e279b6c1SSam Ravnborg	  APM is a BIOS specification for saving power using several different
2473e279b6c1SSam Ravnborg	  techniques. This is mostly useful for battery powered laptops with
2474e279b6c1SSam Ravnborg	  APM compliant BIOSes. If you say Y here, the system time will be
2475e279b6c1SSam Ravnborg	  reset after a RESUME operation, the /proc/apm device will provide
2476e279b6c1SSam Ravnborg	  battery status information, and user-space programs will receive
2477e279b6c1SSam Ravnborg	  notification of APM "events" (e.g. battery status change).
2478e279b6c1SSam Ravnborg
2479e279b6c1SSam Ravnborg	  If you select "Y" here, you can disable actual use of the APM
2480e279b6c1SSam Ravnborg	  BIOS by passing the "apm=off" option to the kernel at boot time.
2481e279b6c1SSam Ravnborg
2482e279b6c1SSam Ravnborg	  Note that the APM support is almost completely disabled for
2483e279b6c1SSam Ravnborg	  machines with more than one CPU.
2484e279b6c1SSam Ravnborg
2485e279b6c1SSam Ravnborg	  In order to use APM, you will need supporting software. For location
2486151f4e2bSMauro Carvalho Chehab	  and more information, read <file:Documentation/power/apm-acpi.rst>
24872dc98fd3SMichael Witten	  and the Battery Powered Linux mini-HOWTO, available from
2488e279b6c1SSam Ravnborg	  <http://www.tldp.org/docs.html#howto>.
2489e279b6c1SSam Ravnborg
2490e279b6c1SSam Ravnborg	  This driver does not spin down disk drives (see the hdparm(8)
2491e279b6c1SSam Ravnborg	  manpage ("man 8 hdparm") for that), and it doesn't turn off
2492e279b6c1SSam Ravnborg	  VESA-compliant "green" monitors.
2493e279b6c1SSam Ravnborg
2494e279b6c1SSam Ravnborg	  This driver does not support the TI 4000M TravelMate and the ACER
2495e279b6c1SSam Ravnborg	  486/DX4/75 because they don't have compliant BIOSes. Many "green"
2496e279b6c1SSam Ravnborg	  desktop machines also don't have compliant BIOSes, and this driver
2497e279b6c1SSam Ravnborg	  may cause those machines to panic during the boot phase.
2498e279b6c1SSam Ravnborg
2499e279b6c1SSam Ravnborg	  Generally, if you don't have a battery in your machine, there isn't
2500e279b6c1SSam Ravnborg	  much point in using this driver and you should say N. If you get
2501e279b6c1SSam Ravnborg	  random kernel OOPSes or reboots that don't seem to be related to
2502e279b6c1SSam Ravnborg	  anything, try disabling/enabling this option (or disabling/enabling
2503e279b6c1SSam Ravnborg	  APM in your BIOS).
2504e279b6c1SSam Ravnborg
2505e279b6c1SSam Ravnborg	  Some other things you should try when experiencing seemingly random,
2506e279b6c1SSam Ravnborg	  "weird" problems:
2507e279b6c1SSam Ravnborg
2508e279b6c1SSam Ravnborg	  1) make sure that you have enough swap space and that it is
2509e279b6c1SSam Ravnborg	  enabled.
2510e279b6c1SSam Ravnborg	  2) pass the "no-hlt" option to the kernel
2511e279b6c1SSam Ravnborg	  3) switch on floating point emulation in the kernel and pass
2512e279b6c1SSam Ravnborg	  the "no387" option to the kernel
2513e279b6c1SSam Ravnborg	  4) pass the "floppy=nodma" option to the kernel
2514e279b6c1SSam Ravnborg	  5) pass the "mem=4M" option to the kernel (thereby disabling
2515e279b6c1SSam Ravnborg	  all but the first 4 MB of RAM)
2516e279b6c1SSam Ravnborg	  6) make sure that the CPU is not over clocked.
2517e279b6c1SSam Ravnborg	  7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/>
2518e279b6c1SSam Ravnborg	  8) disable the cache from your BIOS settings
2519e279b6c1SSam Ravnborg	  9) install a fan for the video card or exchange video RAM
2520e279b6c1SSam Ravnborg	  10) install a better fan for the CPU
2521e279b6c1SSam Ravnborg	  11) exchange RAM chips
2522e279b6c1SSam Ravnborg	  12) exchange the motherboard.
2523e279b6c1SSam Ravnborg
2524e279b6c1SSam Ravnborg	  To compile this driver as a module, choose M here: the
2525e279b6c1SSam Ravnborg	  module will be called apm.
2526e279b6c1SSam Ravnborg
2527e279b6c1SSam Ravnborgif APM
2528e279b6c1SSam Ravnborg
2529e279b6c1SSam Ravnborgconfig APM_IGNORE_USER_SUSPEND
2530e279b6c1SSam Ravnborg	bool "Ignore USER SUSPEND"
25318f9ca475SIngo Molnar	---help---
2532e279b6c1SSam Ravnborg	  This option will ignore USER SUSPEND requests. On machines with a
2533e279b6c1SSam Ravnborg	  compliant APM BIOS, you want to say N. However, on the NEC Versa M
2534e279b6c1SSam Ravnborg	  series notebooks, it is necessary to say Y because of a BIOS bug.
2535e279b6c1SSam Ravnborg
2536e279b6c1SSam Ravnborgconfig APM_DO_ENABLE
2537e279b6c1SSam Ravnborg	bool "Enable PM at boot time"
2538e279b6c1SSam Ravnborg	---help---
2539e279b6c1SSam Ravnborg	  Enable APM features at boot time. From page 36 of the APM BIOS
2540e279b6c1SSam Ravnborg	  specification: "When disabled, the APM BIOS does not automatically
2541e279b6c1SSam Ravnborg	  power manage devices, enter the Standby State, enter the Suspend
2542e279b6c1SSam Ravnborg	  State, or take power saving steps in response to CPU Idle calls."
2543e279b6c1SSam Ravnborg	  This driver will make CPU Idle calls when Linux is idle (unless this
2544e279b6c1SSam Ravnborg	  feature is turned off -- see "Do CPU IDLE calls", below). This
2545e279b6c1SSam Ravnborg	  should always save battery power, but more complicated APM features
2546e279b6c1SSam Ravnborg	  will be dependent on your BIOS implementation. You may need to turn
2547e279b6c1SSam Ravnborg	  this option off if your computer hangs at boot time when using APM
2548e279b6c1SSam Ravnborg	  support, or if it beeps continuously instead of suspending. Turn
2549e279b6c1SSam Ravnborg	  this off if you have a NEC UltraLite Versa 33/C or a Toshiba
2550e279b6c1SSam Ravnborg	  T400CDT. This is off by default since most machines do fine without
2551e279b6c1SSam Ravnborg	  this feature.
2552e279b6c1SSam Ravnborg
2553e279b6c1SSam Ravnborgconfig APM_CPU_IDLE
2554dd8af076SLen Brown	depends on CPU_IDLE
2555e279b6c1SSam Ravnborg	bool "Make CPU Idle calls when idle"
25568f9ca475SIngo Molnar	---help---
2557e279b6c1SSam Ravnborg	  Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop.
2558e279b6c1SSam Ravnborg	  On some machines, this can activate improved power savings, such as
2559e279b6c1SSam Ravnborg	  a slowed CPU clock rate, when the machine is idle. These idle calls
2560e279b6c1SSam Ravnborg	  are made after the idle loop has run for some length of time (e.g.,
2561e279b6c1SSam Ravnborg	  333 mS). On some machines, this will cause a hang at boot time or
2562e279b6c1SSam Ravnborg	  whenever the CPU becomes idle. (On machines with more than one CPU,
2563e279b6c1SSam Ravnborg	  this option does nothing.)
2564e279b6c1SSam Ravnborg
2565e279b6c1SSam Ravnborgconfig APM_DISPLAY_BLANK
2566e279b6c1SSam Ravnborg	bool "Enable console blanking using APM"
25678f9ca475SIngo Molnar	---help---
2568e279b6c1SSam Ravnborg	  Enable console blanking using the APM. Some laptops can use this to
2569e279b6c1SSam Ravnborg	  turn off the LCD backlight when the screen blanker of the Linux
2570e279b6c1SSam Ravnborg	  virtual console blanks the screen. Note that this is only used by
2571e279b6c1SSam Ravnborg	  the virtual console screen blanker, and won't turn off the backlight
2572e279b6c1SSam Ravnborg	  when using the X Window system. This also doesn't have anything to
2573e279b6c1SSam Ravnborg	  do with your VESA-compliant power-saving monitor. Further, this
2574e279b6c1SSam Ravnborg	  option doesn't work for all laptops -- it might not turn off your
2575e279b6c1SSam Ravnborg	  backlight at all, or it might print a lot of errors to the console,
2576e279b6c1SSam Ravnborg	  especially if you are using gpm.
2577e279b6c1SSam Ravnborg
2578e279b6c1SSam Ravnborgconfig APM_ALLOW_INTS
2579e279b6c1SSam Ravnborg	bool "Allow interrupts during APM BIOS calls"
25808f9ca475SIngo Molnar	---help---
2581e279b6c1SSam Ravnborg	  Normally we disable external interrupts while we are making calls to
2582e279b6c1SSam Ravnborg	  the APM BIOS as a measure to lessen the effects of a badly behaving
2583e279b6c1SSam Ravnborg	  BIOS implementation.  The BIOS should reenable interrupts if it
2584e279b6c1SSam Ravnborg	  needs to.  Unfortunately, some BIOSes do not -- especially those in
2585e279b6c1SSam Ravnborg	  many of the newer IBM Thinkpads.  If you experience hangs when you
2586e279b6c1SSam Ravnborg	  suspend, try setting this to Y.  Otherwise, say N.
2587e279b6c1SSam Ravnborg
2588e279b6c1SSam Ravnborgendif # APM
2589e279b6c1SSam Ravnborg
2590bb0a56ecSDave Jonessource "drivers/cpufreq/Kconfig"
2591e279b6c1SSam Ravnborg
2592e279b6c1SSam Ravnborgsource "drivers/cpuidle/Kconfig"
2593e279b6c1SSam Ravnborg
259427471fdbSAndy Henroidsource "drivers/idle/Kconfig"
259527471fdbSAndy Henroid
2596e279b6c1SSam Ravnborgendmenu
2597e279b6c1SSam Ravnborg
2598e279b6c1SSam Ravnborg
2599e279b6c1SSam Ravnborgmenu "Bus options (PCI etc.)"
2600e279b6c1SSam Ravnborg
2601e279b6c1SSam Ravnborgchoice
2602e279b6c1SSam Ravnborg	prompt "PCI access mode"
2603efefa6f6SIngo Molnar	depends on X86_32 && PCI
2604e279b6c1SSam Ravnborg	default PCI_GOANY
2605e279b6c1SSam Ravnborg	---help---
2606e279b6c1SSam Ravnborg	  On PCI systems, the BIOS can be used to detect the PCI devices and
2607e279b6c1SSam Ravnborg	  determine their configuration. However, some old PCI motherboards
2608e279b6c1SSam Ravnborg	  have BIOS bugs and may crash if this is done. Also, some embedded
2609e279b6c1SSam Ravnborg	  PCI-based systems don't have any BIOS at all. Linux can also try to
2610e279b6c1SSam Ravnborg	  detect the PCI hardware directly without using the BIOS.
2611e279b6c1SSam Ravnborg
2612e279b6c1SSam Ravnborg	  With this option, you can specify how Linux should detect the
2613e279b6c1SSam Ravnborg	  PCI devices. If you choose "BIOS", the BIOS will be used,
2614e279b6c1SSam Ravnborg	  if you choose "Direct", the BIOS won't be used, and if you
2615e279b6c1SSam Ravnborg	  choose "MMConfig", then PCI Express MMCONFIG will be used.
2616e279b6c1SSam Ravnborg	  If you choose "Any", the kernel will try MMCONFIG, then the
2617e279b6c1SSam Ravnborg	  direct access method and falls back to the BIOS if that doesn't
2618e279b6c1SSam Ravnborg	  work. If unsure, go with the default, which is "Any".
2619e279b6c1SSam Ravnborg
2620e279b6c1SSam Ravnborgconfig PCI_GOBIOS
2621e279b6c1SSam Ravnborg	bool "BIOS"
2622e279b6c1SSam Ravnborg
2623e279b6c1SSam Ravnborgconfig PCI_GOMMCONFIG
2624e279b6c1SSam Ravnborg	bool "MMConfig"
2625e279b6c1SSam Ravnborg
2626e279b6c1SSam Ravnborgconfig PCI_GODIRECT
2627e279b6c1SSam Ravnborg	bool "Direct"
2628e279b6c1SSam Ravnborg
26293ef0e1f8SAndres Salomonconfig PCI_GOOLPC
263076fb6570SDaniel Drake	bool "OLPC XO-1"
26313ef0e1f8SAndres Salomon	depends on OLPC
26323ef0e1f8SAndres Salomon
26332bdd1b03SAndres Salomonconfig PCI_GOANY
26342bdd1b03SAndres Salomon	bool "Any"
26352bdd1b03SAndres Salomon
2636e279b6c1SSam Ravnborgendchoice
2637e279b6c1SSam Ravnborg
2638e279b6c1SSam Ravnborgconfig PCI_BIOS
26393c2362e6SHarvey Harrison	def_bool y
2640efefa6f6SIngo Molnar	depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY)
2641e279b6c1SSam Ravnborg
2642e279b6c1SSam Ravnborg# x86-64 doesn't support PCI BIOS access from long mode so always go direct.
2643e279b6c1SSam Ravnborgconfig PCI_DIRECT
26443c2362e6SHarvey Harrison	def_bool y
26450aba496fSShaohua Li	depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC || PCI_GOMMCONFIG))
2646e279b6c1SSam Ravnborg
2647e279b6c1SSam Ravnborgconfig PCI_MMCONFIG
2648b45c9f36SJan Kiszka	bool "Support mmconfig PCI config space access" if X86_64
2649b45c9f36SJan Kiszka	default y
26508364e1f8SJan Kiszka	depends on PCI && (ACPI || SFI || JAILHOUSE_GUEST)
2651b45c9f36SJan Kiszka	depends on X86_64 || (PCI_GOANY || PCI_GOMMCONFIG)
2652e279b6c1SSam Ravnborg
26533ef0e1f8SAndres Salomonconfig PCI_OLPC
26542bdd1b03SAndres Salomon	def_bool y
26552bdd1b03SAndres Salomon	depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY)
26563ef0e1f8SAndres Salomon
2657b5401a96SAlex Nixonconfig PCI_XEN
2658b5401a96SAlex Nixon	def_bool y
2659b5401a96SAlex Nixon	depends on PCI && XEN
2660b5401a96SAlex Nixon	select SWIOTLB_XEN
2661b5401a96SAlex Nixon
26628364e1f8SJan Kiszkaconfig MMCONF_FAM10H
26638364e1f8SJan Kiszka	def_bool y
26648364e1f8SJan Kiszka	depends on X86_64 && PCI_MMCONFIG && ACPI
2665e279b6c1SSam Ravnborg
26663f6ea84aSIra W. Snyderconfig PCI_CNB20LE_QUIRK
26676a108a14SDavid Rientjes	bool "Read CNB20LE Host Bridge Windows" if EXPERT
26686ea30386SKees Cook	depends on PCI
26693f6ea84aSIra W. Snyder	help
26703f6ea84aSIra W. Snyder	  Read the PCI windows out of the CNB20LE host bridge. This allows
26713f6ea84aSIra W. Snyder	  PCI hotplug to work on systems with the CNB20LE chipset which do
26723f6ea84aSIra W. Snyder	  not have ACPI.
26733f6ea84aSIra W. Snyder
267464a5fed6SBjorn Helgaas	  There's no public spec for this chipset, and this functionality
267564a5fed6SBjorn Helgaas	  is known to be incomplete.
267664a5fed6SBjorn Helgaas
267764a5fed6SBjorn Helgaas	  You should say N unless you know you need this.
267864a5fed6SBjorn Helgaas
26793a495511SWilliam Breathitt Grayconfig ISA_BUS
268017a2a129SWilliam Breathitt Gray	bool "ISA bus support on modern systems" if EXPERT
26813a495511SWilliam Breathitt Gray	help
268217a2a129SWilliam Breathitt Gray	  Expose ISA bus device drivers and options available for selection and
268317a2a129SWilliam Breathitt Gray	  configuration. Enable this option if your target machine has an ISA
268417a2a129SWilliam Breathitt Gray	  bus. ISA is an older system, displaced by PCI and newer bus
268517a2a129SWilliam Breathitt Gray	  architectures -- if your target machine is modern, it probably does
268617a2a129SWilliam Breathitt Gray	  not have an ISA bus.
26873a495511SWilliam Breathitt Gray
26883a495511SWilliam Breathitt Gray	  If unsure, say N.
26893a495511SWilliam Breathitt Gray
26901c00f016SDavid Rientjes# x86_64 have no ISA slots, but can have ISA-style DMA.
2691e279b6c1SSam Ravnborgconfig ISA_DMA_API
26921c00f016SDavid Rientjes	bool "ISA-style DMA support" if (X86_64 && EXPERT)
26931c00f016SDavid Rientjes	default y
26941c00f016SDavid Rientjes	help
26951c00f016SDavid Rientjes	  Enables ISA-style DMA support for devices requiring such controllers.
26961c00f016SDavid Rientjes	  If unsure, say Y.
2697e279b6c1SSam Ravnborg
269851e68d05SLinus Torvaldsif X86_32
269951e68d05SLinus Torvalds
2700e279b6c1SSam Ravnborgconfig ISA
2701e279b6c1SSam Ravnborg	bool "ISA support"
27028f9ca475SIngo Molnar	---help---
2703e279b6c1SSam Ravnborg	  Find out whether you have ISA slots on your motherboard.  ISA is the
2704e279b6c1SSam Ravnborg	  name of a bus system, i.e. the way the CPU talks to the other stuff
2705e279b6c1SSam Ravnborg	  inside your box.  Other bus systems are PCI, EISA, MicroChannel
2706e279b6c1SSam Ravnborg	  (MCA) or VESA.  ISA is an older system, now being displaced by PCI;
2707e279b6c1SSam Ravnborg	  newer boards don't support it.  If you have ISA, say Y, otherwise N.
2708e279b6c1SSam Ravnborg
2709e279b6c1SSam Ravnborgconfig SCx200
2710e279b6c1SSam Ravnborg	tristate "NatSemi SCx200 support"
27118f9ca475SIngo Molnar	---help---
2712e279b6c1SSam Ravnborg	  This provides basic support for National Semiconductor's
2713e279b6c1SSam Ravnborg	  (now AMD's) Geode processors.  The driver probes for the
2714e279b6c1SSam Ravnborg	  PCI-IDs of several on-chip devices, so its a good dependency
2715e279b6c1SSam Ravnborg	  for other scx200_* drivers.
2716e279b6c1SSam Ravnborg
2717e279b6c1SSam Ravnborg	  If compiled as a module, the driver is named scx200.
2718e279b6c1SSam Ravnborg
2719e279b6c1SSam Ravnborgconfig SCx200HR_TIMER
2720e279b6c1SSam Ravnborg	tristate "NatSemi SCx200 27MHz High-Resolution Timer Support"
2721592913ecSJohn Stultz	depends on SCx200
2722e279b6c1SSam Ravnborg	default y
27238f9ca475SIngo Molnar	---help---
2724e279b6c1SSam Ravnborg	  This driver provides a clocksource built upon the on-chip
2725e279b6c1SSam Ravnborg	  27MHz high-resolution timer.  Its also a workaround for
2726e279b6c1SSam Ravnborg	  NSC Geode SC-1100's buggy TSC, which loses time when the
2727e279b6c1SSam Ravnborg	  processor goes idle (as is done by the scheduler).  The
2728e279b6c1SSam Ravnborg	  other workaround is idle=poll boot option.
2729e279b6c1SSam Ravnborg
27303ef0e1f8SAndres Salomonconfig OLPC
27313ef0e1f8SAndres Salomon	bool "One Laptop Per Child support"
273254008979SThomas Gleixner	depends on !X86_PAE
27333c554946SAndres Salomon	select GPIOLIB
2734dc3119e7SThomas Gleixner	select OF
273545bb1674SDaniel Drake	select OF_PROMTREE
2736b4e51854SGrant Likely	select IRQ_DOMAIN
27370c3d931bSLubomir Rintel	select OLPC_EC
27388f9ca475SIngo Molnar	---help---
27393ef0e1f8SAndres Salomon	  Add support for detecting the unique features of the OLPC
27403ef0e1f8SAndres Salomon	  XO hardware.
27413ef0e1f8SAndres Salomon
2742a3128588SDaniel Drakeconfig OLPC_XO1_PM
2743a3128588SDaniel Drake	bool "OLPC XO-1 Power Management"
2744fa112cf1SBorislav Petkov	depends on OLPC && MFD_CS5535=y && PM_SLEEP
2745bf1ebf00SDaniel Drake	---help---
274697c4cb71SDaniel Drake	  Add support for poweroff and suspend of the OLPC XO-1 laptop.
2747bf1ebf00SDaniel Drake
2748cfee9597SDaniel Drakeconfig OLPC_XO1_RTC
2749cfee9597SDaniel Drake	bool "OLPC XO-1 Real Time Clock"
2750cfee9597SDaniel Drake	depends on OLPC_XO1_PM && RTC_DRV_CMOS
2751cfee9597SDaniel Drake	---help---
2752cfee9597SDaniel Drake	  Add support for the XO-1 real time clock, which can be used as a
2753cfee9597SDaniel Drake	  programmable wakeup source.
2754cfee9597SDaniel Drake
27557feda8e9SDaniel Drakeconfig OLPC_XO1_SCI
27567feda8e9SDaniel Drake	bool "OLPC XO-1 SCI extras"
275792e830f2SArnd Bergmann	depends on OLPC && OLPC_XO1_PM && GPIO_CS5535=y
2758ed8e47feSRandy Dunlap	depends on INPUT=y
2759d8d01a63SDaniel Drake	select POWER_SUPPLY
27607feda8e9SDaniel Drake	---help---
27617feda8e9SDaniel Drake	  Add support for SCI-based features of the OLPC XO-1 laptop:
27627bc74b3dSDaniel Drake	   - EC-driven system wakeups
27637feda8e9SDaniel Drake	   - Power button
27647bc74b3dSDaniel Drake	   - Ebook switch
27652cf2baeaSDaniel Drake	   - Lid switch
2766e1040ac6SDaniel Drake	   - AC adapter status updates
2767e1040ac6SDaniel Drake	   - Battery status updates
27687feda8e9SDaniel Drake
2769a0f30f59SDaniel Drakeconfig OLPC_XO15_SCI
2770a0f30f59SDaniel Drake	bool "OLPC XO-1.5 SCI extras"
2771d8d01a63SDaniel Drake	depends on OLPC && ACPI
2772d8d01a63SDaniel Drake	select POWER_SUPPLY
2773a0f30f59SDaniel Drake	---help---
2774a0f30f59SDaniel Drake	  Add support for SCI-based features of the OLPC XO-1.5 laptop:
2775a0f30f59SDaniel Drake	   - EC-driven system wakeups
2776a0f30f59SDaniel Drake	   - AC adapter status updates
2777a0f30f59SDaniel Drake	   - Battery status updates
2778e279b6c1SSam Ravnborg
2779d4f3e350SEd Wildgooseconfig ALIX
2780d4f3e350SEd Wildgoose	bool "PCEngines ALIX System Support (LED setup)"
2781d4f3e350SEd Wildgoose	select GPIOLIB
2782d4f3e350SEd Wildgoose	---help---
2783d4f3e350SEd Wildgoose	  This option enables system support for the PCEngines ALIX.
2784d4f3e350SEd Wildgoose	  At present this just sets up LEDs for GPIO control on
2785d4f3e350SEd Wildgoose	  ALIX2/3/6 boards.  However, other system specific setup should
2786d4f3e350SEd Wildgoose	  get added here.
2787d4f3e350SEd Wildgoose
2788d4f3e350SEd Wildgoose	  Note: You must still enable the drivers for GPIO and LED support
2789d4f3e350SEd Wildgoose	  (GPIO_CS5535 & LEDS_GPIO) to actually use the LEDs
2790d4f3e350SEd Wildgoose
2791d4f3e350SEd Wildgoose	  Note: You have to set alix.force=1 for boards with Award BIOS.
2792d4f3e350SEd Wildgoose
2793da4e3302SPhilip Prindevilleconfig NET5501
2794da4e3302SPhilip Prindeville	bool "Soekris Engineering net5501 System Support (LEDS, GPIO, etc)"
2795da4e3302SPhilip Prindeville	select GPIOLIB
2796da4e3302SPhilip Prindeville	---help---
2797da4e3302SPhilip Prindeville	  This option enables system support for the Soekris Engineering net5501.
2798da4e3302SPhilip Prindeville
27993197059aSPhilip A. Prindevilleconfig GEOS
28003197059aSPhilip A. Prindeville	bool "Traverse Technologies GEOS System Support (LEDS, GPIO, etc)"
28013197059aSPhilip A. Prindeville	select GPIOLIB
28023197059aSPhilip A. Prindeville	depends on DMI
28033197059aSPhilip A. Prindeville	---help---
28043197059aSPhilip A. Prindeville	  This option enables system support for the Traverse Technologies GEOS.
28053197059aSPhilip A. Prindeville
28067d029125SVivien Didelotconfig TS5500
28077d029125SVivien Didelot	bool "Technologic Systems TS-5500 platform support"
28087d029125SVivien Didelot	depends on MELAN
28097d029125SVivien Didelot	select CHECK_SIGNATURE
28107d029125SVivien Didelot	select NEW_LEDS
28117d029125SVivien Didelot	select LEDS_CLASS
28127d029125SVivien Didelot	---help---
28137d029125SVivien Didelot	  This option enables system support for the Technologic Systems TS-5500.
28147d029125SVivien Didelot
2815e279b6c1SSam Ravnborgendif # X86_32
2816e279b6c1SSam Ravnborg
281723ac4ae8SAndreas Herrmannconfig AMD_NB
2818e279b6c1SSam Ravnborg	def_bool y
28190e152cd7SBorislav Petkov	depends on CPU_SUP_AMD && PCI
2820e279b6c1SSam Ravnborg
2821e3263ab3SDavid Herrmannconfig X86_SYSFB
2822e3263ab3SDavid Herrmann	bool "Mark VGA/VBE/EFI FB as generic system framebuffer"
2823e3263ab3SDavid Herrmann	help
2824e3263ab3SDavid Herrmann	  Firmwares often provide initial graphics framebuffers so the BIOS,
2825e3263ab3SDavid Herrmann	  bootloader or kernel can show basic video-output during boot for
2826e3263ab3SDavid Herrmann	  user-guidance and debugging. Historically, x86 used the VESA BIOS
2827e3263ab3SDavid Herrmann	  Extensions and EFI-framebuffers for this, which are mostly limited
2828e3263ab3SDavid Herrmann	  to x86.
2829e3263ab3SDavid Herrmann	  This option, if enabled, marks VGA/VBE/EFI framebuffers as generic
2830e3263ab3SDavid Herrmann	  framebuffers so the new generic system-framebuffer drivers can be
2831e3263ab3SDavid Herrmann	  used on x86. If the framebuffer is not compatible with the generic
2832e3a5dc08SNikolas Nyby	  modes, it is advertised as fallback platform framebuffer so legacy
2833e3263ab3SDavid Herrmann	  drivers like efifb, vesafb and uvesafb can pick it up.
2834e3263ab3SDavid Herrmann	  If this option is not selected, all system framebuffers are always
2835e3263ab3SDavid Herrmann	  marked as fallback platform framebuffers as usual.
2836e3263ab3SDavid Herrmann
2837e3263ab3SDavid Herrmann	  Note: Legacy fbdev drivers, including vesafb, efifb, uvesafb, will
2838e3263ab3SDavid Herrmann	  not be able to pick up generic system framebuffers if this option
2839e3263ab3SDavid Herrmann	  is selected. You are highly encouraged to enable simplefb as
2840e3263ab3SDavid Herrmann	  replacement if you select this option. simplefb can correctly deal
2841e3263ab3SDavid Herrmann	  with generic system framebuffers. But you should still keep vesafb
2842e3263ab3SDavid Herrmann	  and others enabled as fallback if a system framebuffer is
2843e3263ab3SDavid Herrmann	  incompatible with simplefb.
2844e3263ab3SDavid Herrmann
2845e3263ab3SDavid Herrmann	  If unsure, say Y.
2846e3263ab3SDavid Herrmann
2847e279b6c1SSam Ravnborgendmenu
2848e279b6c1SSam Ravnborg
2849e279b6c1SSam Ravnborg
28501572497cSChristoph Hellwigmenu "Binary Emulations"
2851e279b6c1SSam Ravnborg
2852e279b6c1SSam Ravnborgconfig IA32_EMULATION
2853e279b6c1SSam Ravnborg	bool "IA32 Emulation"
2854e279b6c1SSam Ravnborg	depends on X86_64
285539f88911SIngo Molnar	select ARCH_WANT_OLD_COMPAT_IPC
2856d1603990SRandy Dunlap	select BINFMT_ELF
2857a97f52e6SRoland McGrath	select COMPAT_BINFMT_ELF
285839f88911SIngo Molnar	select COMPAT_OLD_SIGACTION
28598f9ca475SIngo Molnar	---help---
28605fd92e65SH. J. Lu	  Include code to run legacy 32-bit programs under a
28615fd92e65SH. J. Lu	  64-bit kernel. You should likely turn this on, unless you're
28625fd92e65SH. J. Lu	  100% sure that you don't have any 32-bit programs left.
2863e279b6c1SSam Ravnborg
2864e279b6c1SSam Ravnborgconfig IA32_AOUT
2865e279b6c1SSam Ravnborg	tristate "IA32 a.out support"
28666b213e1bSDavid Woodhouse	depends on IA32_EMULATION
2867eac61655SBorislav Petkov	depends on BROKEN
28688f9ca475SIngo Molnar	---help---
2869e279b6c1SSam Ravnborg	  Support old a.out binaries in the 32bit emulation.
2870e279b6c1SSam Ravnborg
28710bf62763SH. Peter Anvinconfig X86_X32
28726ea30386SKees Cook	bool "x32 ABI for 64-bit mode"
28739b54050bSBrian Gerst	depends on X86_64
28745fd92e65SH. J. Lu	---help---
28755fd92e65SH. J. Lu	  Include code to run binaries for the x32 native 32-bit ABI
28765fd92e65SH. J. Lu	  for 64-bit processors.  An x32 process gets access to the
28775fd92e65SH. J. Lu	  full 64-bit register file and wide data path while leaving
28785fd92e65SH. J. Lu	  pointers at 32 bits for smaller memory footprint.
28795fd92e65SH. J. Lu
28805fd92e65SH. J. Lu	  You will need a recent binutils (2.22 or later) with
28815fd92e65SH. J. Lu	  elf32_x86_64 support enabled to compile a kernel with this
28825fd92e65SH. J. Lu	  option set.
28835fd92e65SH. J. Lu
2884953fee1dSIngo Molnarconfig COMPAT_32
2885953fee1dSIngo Molnar	def_bool y
2886953fee1dSIngo Molnar	depends on IA32_EMULATION || X86_32
2887953fee1dSIngo Molnar	select HAVE_UID16
2888953fee1dSIngo Molnar	select OLD_SIGSUSPEND3
2889953fee1dSIngo Molnar
2890e279b6c1SSam Ravnborgconfig COMPAT
28913c2362e6SHarvey Harrison	def_bool y
28920bf62763SH. Peter Anvin	depends on IA32_EMULATION || X86_X32
2893e279b6c1SSam Ravnborg
28943120e25eSJan Beulichif COMPAT
2895e279b6c1SSam Ravnborgconfig COMPAT_FOR_U64_ALIGNMENT
28963120e25eSJan Beulich	def_bool y
2897e279b6c1SSam Ravnborg
2898e279b6c1SSam Ravnborgconfig SYSVIPC_COMPAT
28993c2362e6SHarvey Harrison	def_bool y
29003120e25eSJan Beulich	depends on SYSVIPC
29013120e25eSJan Beulichendif
2902ee009e4aSDavid Howells
2903e279b6c1SSam Ravnborgendmenu
2904e279b6c1SSam Ravnborg
2905e279b6c1SSam Ravnborg
2906e5beae16SKeith Packardconfig HAVE_ATOMIC_IOMAP
2907e5beae16SKeith Packard	def_bool y
2908e5beae16SKeith Packard	depends on X86_32
2909e5beae16SKeith Packard
29104692d77fSAlessandro Rubiniconfig X86_DEV_DMA_OPS
29114692d77fSAlessandro Rubini	bool
2912f7219a53SAlessandro Rubini
2913e279b6c1SSam Ravnborgsource "drivers/firmware/Kconfig"
2914e279b6c1SSam Ravnborg
2915edf88417SAvi Kivitysource "arch/x86/kvm/Kconfig"
2916