xref: /linux/arch/x86/Kconfig (revision 38f3e775e9c242f5430a9c08c11be7577f63a41c)
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
27c12d3362SArd Biesheuvel	select ARCH_SUPPORTS_INT128 if CC_HAS_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
331032c0baSSam Ravnborg
34518049d9SSteven Rostedt (VMware)config FORCE_DYNAMIC_FTRACE
35518049d9SSteven Rostedt (VMware)	def_bool y
36518049d9SSteven Rostedt (VMware)	depends on X86_32
37518049d9SSteven Rostedt (VMware)	depends on FUNCTION_TRACER
38518049d9SSteven Rostedt (VMware)	select DYNAMIC_FTRACE
39518049d9SSteven Rostedt (VMware)	help
40518049d9SSteven Rostedt (VMware)	 We keep the static function tracing (!DYNAMIC_FTRACE) around
41518049d9SSteven Rostedt (VMware)	 in order to test the non static function tracing in the
42518049d9SSteven Rostedt (VMware)	 generic code, as other architectures still use it. But we
43518049d9SSteven Rostedt (VMware)	 only need to keep it around for x86_64. No need to keep it
44518049d9SSteven Rostedt (VMware)	 for x86_32. For x86_32, force DYNAMIC_FTRACE.
45d94e0685SIngo Molnar#
46d94e0685SIngo Molnar# Arch settings
47d94e0685SIngo Molnar#
48d94e0685SIngo Molnar# ( Note that options that are marked 'if X86_64' could in principle be
49d94e0685SIngo Molnar#   ported to 32-bit as well. )
50d94e0685SIngo Molnar#
518d5fffb9SSam Ravnborgconfig X86
523c2362e6SHarvey Harrison	def_bool y
53c763ea26SIngo Molnar	#
54c763ea26SIngo Molnar	# Note: keep this list sorted alphabetically
55c763ea26SIngo Molnar	#
566471b825SIngo Molnar	select ACPI_LEGACY_TABLES_LOOKUP	if ACPI
576e0a0ea1SGraeme Gregory	select ACPI_SYSTEM_POWER_STATES_SUPPORT	if ACPI
58942fa985SYury Norov	select ARCH_32BIT_OFF_T			if X86_32
592a21ad57SThomas Gleixner	select ARCH_CLOCKSOURCE_INIT
6091dda51aSAleksey Makarov	select ARCH_HAS_ACPI_TABLE_UPGRADE	if ACPI
61fa5b6ec9SLaura Abbott	select ARCH_HAS_DEBUG_VIRTUAL
6221266be9SDan Williams	select ARCH_HAS_DEVMEM_IS_ALLOWED
636471b825SIngo Molnar	select ARCH_HAS_ELF_RANDOMIZE
6472d93104SLinus Torvalds	select ARCH_HAS_FAST_MULTIPLIER
65316d097cSDave Hansen	select ARCH_HAS_FILTER_PGPROT
666974f0c4SDaniel Micay	select ARCH_HAS_FORTIFY_SOURCE
67957e3facSRiku Voipio	select ARCH_HAS_GCOV_PROFILE_ALL
685c9a8750SDmitry Vyukov	select ARCH_HAS_KCOV			if X86_64
690c9c1d56SThiago Jung Bauermann	select ARCH_HAS_MEM_ENCRYPT
7010bcc80eSMathieu Desnoyers	select ARCH_HAS_MEMBARRIER_SYNC_CORE
71c763ea26SIngo Molnar	select ARCH_HAS_PMEM_API		if X86_64
7217596731SRobin Murphy	select ARCH_HAS_PTE_DEVMAP		if X86_64
733010a5eaSLaurent Dufour	select ARCH_HAS_PTE_SPECIAL
740aed55afSDan Williams	select ARCH_HAS_UACCESS_FLUSHCACHE	if X86_64
75092b31aaSDan Williams	select ARCH_HAS_UACCESS_MCSAFE		if X86_64 && X86_MCE
76d2852a22SDaniel Borkmann	select ARCH_HAS_SET_MEMORY
77d253ca0cSRick Edgecombe	select ARCH_HAS_SET_DIRECT_MAP
78ad21fc4fSLaura Abbott	select ARCH_HAS_STRICT_KERNEL_RWX
79ad21fc4fSLaura Abbott	select ARCH_HAS_STRICT_MODULE_RWX
80ac1ab12aSMathieu Desnoyers	select ARCH_HAS_SYNC_CORE_BEFORE_USERMODE
8125c619e5SBrian Gerst	select ARCH_HAS_SYSCALL_WRAPPER
82c6d30853SAndrey Ryabinin	select ARCH_HAS_UBSAN_SANITIZE_ALL
836471b825SIngo Molnar	select ARCH_HAVE_NMI_SAFE_CMPXCHG
846471b825SIngo Molnar	select ARCH_MIGHT_HAVE_ACPI_PDC		if ACPI
8577fbbc81SMark Salter	select ARCH_MIGHT_HAVE_PC_PARPORT
865e2c18c0SMark Salter	select ARCH_MIGHT_HAVE_PC_SERIO
873599fe12SThomas Gleixner	select ARCH_STACKWALK
882c870e61SArnd Bergmann	select ARCH_SUPPORTS_ACPI
896471b825SIngo Molnar	select ARCH_SUPPORTS_ATOMIC_RMW
906471b825SIngo Molnar	select ARCH_SUPPORTS_NUMA_BALANCING	if X86_64
916471b825SIngo Molnar	select ARCH_USE_BUILTIN_BSWAP
926471b825SIngo Molnar	select ARCH_USE_QUEUED_RWLOCKS
936471b825SIngo Molnar	select ARCH_USE_QUEUED_SPINLOCKS
94ce4a4e56SAndy Lutomirski	select ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH
9581c22041SDaniel Borkmann	select ARCH_WANT_DEFAULT_BPF_JIT	if X86_64
96c763ea26SIngo Molnar	select ARCH_WANTS_DYNAMIC_TASK_STRUCT
973876d4a3SAlexandre Ghiti	select ARCH_WANT_HUGE_PMD_SHARE
9838d8b4e6SHuang Ying	select ARCH_WANTS_THP_SWAP		if X86_64
9910916706SShile Zhang	select BUILDTIME_TABLE_SORT
1006471b825SIngo Molnar	select CLKEVT_I8253
1016471b825SIngo Molnar	select CLOCKSOURCE_VALIDATE_LAST_CYCLE
1026471b825SIngo Molnar	select CLOCKSOURCE_WATCHDOG
1036471b825SIngo Molnar	select DCACHE_WORD_ACCESS
10445471cd9SLinus Torvalds	select EDAC_ATOMIC_SCRUB
10545471cd9SLinus Torvalds	select EDAC_SUPPORT
1066471b825SIngo Molnar	select GENERIC_CLOCKEVENTS
1076471b825SIngo Molnar	select GENERIC_CLOCKEVENTS_BROADCAST	if X86_64 || (X86_32 && X86_LOCAL_APIC)
1086471b825SIngo Molnar	select GENERIC_CLOCKEVENTS_MIN_ADJUST
1096471b825SIngo Molnar	select GENERIC_CMOS_UPDATE
1106471b825SIngo Molnar	select GENERIC_CPU_AUTOPROBE
11161dc0f55SThomas Gleixner	select GENERIC_CPU_VULNERABILITIES
1126471b825SIngo Molnar	select GENERIC_EARLY_IOREMAP
1136471b825SIngo Molnar	select GENERIC_FIND_FIRST_BIT
1146471b825SIngo Molnar	select GENERIC_IOMAP
115c7d6c9ddSThomas Gleixner	select GENERIC_IRQ_EFFECTIVE_AFF_MASK	if SMP
1160fa115daSThomas Gleixner	select GENERIC_IRQ_MATRIX_ALLOCATOR	if X86_LOCAL_APIC
117ad7a929fSThomas Gleixner	select GENERIC_IRQ_MIGRATION		if SMP
1186471b825SIngo Molnar	select GENERIC_IRQ_PROBE
119c201c917SThomas Gleixner	select GENERIC_IRQ_RESERVATION_MODE
1206471b825SIngo Molnar	select GENERIC_IRQ_SHOW
1216471b825SIngo Molnar	select GENERIC_PENDING_IRQ		if SMP
1222ae27137SSteven Price	select GENERIC_PTDUMP
1236471b825SIngo Molnar	select GENERIC_SMP_IDLE_THREAD
1246471b825SIngo Molnar	select GENERIC_STRNCPY_FROM_USER
1256471b825SIngo Molnar	select GENERIC_STRNLEN_USER
1266471b825SIngo Molnar	select GENERIC_TIME_VSYSCALL
1277ac87074SVincenzo Frascino	select GENERIC_GETTIMEOFDAY
128550a77a7SDmitry Safonov	select GENERIC_VDSO_TIME_NS
12939656e83SChristoph Hellwig	select GUP_GET_PTE_LOW_HIGH		if X86_PAE
13017e5888eSHans de Goede	select HARDIRQS_SW_RESEND
1317edaeb68SThomas Gleixner	select HARDLOCKUP_CHECK_TIMESTAMP	if X86_64
1326471b825SIngo Molnar	select HAVE_ACPI_APEI			if ACPI
1336471b825SIngo Molnar	select HAVE_ACPI_APEI_NMI		if ACPI
1346471b825SIngo Molnar	select HAVE_ALIGNED_STRUCT_PAGE		if SLUB
1356471b825SIngo Molnar	select HAVE_ARCH_AUDITSYSCALL
1366471b825SIngo Molnar	select HAVE_ARCH_HUGE_VMAP		if X86_64 || X86_PAE
1376471b825SIngo Molnar	select HAVE_ARCH_JUMP_LABEL
138b34006c4SArd Biesheuvel	select HAVE_ARCH_JUMP_LABEL_RELATIVE
139d17a1d97SAndrey Ryabinin	select HAVE_ARCH_KASAN			if X86_64
1400609ae01SDaniel Axtens	select HAVE_ARCH_KASAN_VMALLOC		if X86_64
1416471b825SIngo Molnar	select HAVE_ARCH_KGDB
1429e08f57dSDaniel Cashman	select HAVE_ARCH_MMAP_RND_BITS		if MMU
1439e08f57dSDaniel Cashman	select HAVE_ARCH_MMAP_RND_COMPAT_BITS	if MMU && COMPAT
1441b028f78SDmitry Safonov	select HAVE_ARCH_COMPAT_MMAP_BASES	if MMU && COMPAT
145271ca788SArd Biesheuvel	select HAVE_ARCH_PREL32_RELOCATIONS
1466471b825SIngo Molnar	select HAVE_ARCH_SECCOMP_FILTER
147f7d83c1cSKees Cook	select HAVE_ARCH_THREAD_STRUCT_WHITELIST
148afaef01cSAlexander Popov	select HAVE_ARCH_STACKLEAK
1496471b825SIngo Molnar	select HAVE_ARCH_TRACEHOOK
1506471b825SIngo Molnar	select HAVE_ARCH_TRANSPARENT_HUGEPAGE
151a00cc7d9SMatthew Wilcox	select HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD if X86_64
1525a281062SAndrea Arcangeli	select HAVE_ARCH_USERFAULTFD_WP		if USERFAULTFD
153e37e43a4SAndy Lutomirski	select HAVE_ARCH_VMAP_STACK		if X86_64
154c763ea26SIngo Molnar	select HAVE_ARCH_WITHIN_STACK_FRAMES
1552ff2b7ecSMasahiro Yamada	select HAVE_ASM_MODVERSIONS
1566471b825SIngo Molnar	select HAVE_CMPXCHG_DOUBLE
1576471b825SIngo Molnar	select HAVE_CMPXCHG_LOCAL
1586471b825SIngo Molnar	select HAVE_CONTEXT_TRACKING		if X86_64
159c1bd55f9SJosh Triplett	select HAVE_COPY_THREAD_TLS
1606471b825SIngo Molnar	select HAVE_C_RECORDMCOUNT
1616471b825SIngo Molnar	select HAVE_DEBUG_KMEMLEAK
1629c5a3621SAkinobu Mita	select HAVE_DMA_CONTIGUOUS
163677aa9f7SSteven Rostedt	select HAVE_DYNAMIC_FTRACE
16406aeaaeaSMasami Hiramatsu	select HAVE_DYNAMIC_FTRACE_WITH_REGS
165562955feSSteven Rostedt (VMware)	select HAVE_DYNAMIC_FTRACE_WITH_DIRECT_CALLS
16603f5781bSWang YanQing	select HAVE_EBPF_JIT
16758340a07SJohannes Berg	select HAVE_EFFICIENT_UNALIGNED_ACCESS
1686630a8e5SChristoph Hellwig	select HAVE_EISA
1695f56a5dfSJiri Slaby	select HAVE_EXIT_THREAD
17067a929e0SChristoph Hellwig	select HAVE_FAST_GUP
171644e0e8dSSteven Rostedt (VMware)	select HAVE_FENTRY			if X86_64 || DYNAMIC_FTRACE
1726471b825SIngo Molnar	select HAVE_FTRACE_MCOUNT_RECORD
1736471b825SIngo Molnar	select HAVE_FUNCTION_GRAPH_TRACER
1746471b825SIngo Molnar	select HAVE_FUNCTION_TRACER
1756b90bd4bSEmese Revfy	select HAVE_GCC_PLUGINS
1760067f129SK.Prasad	select HAVE_HW_BREAKPOINT
1776471b825SIngo Molnar	select HAVE_IDE
1786471b825SIngo Molnar	select HAVE_IOREMAP_PROT
1796471b825SIngo Molnar	select HAVE_IRQ_EXIT_ON_IRQ_STACK	if X86_64
1806471b825SIngo Molnar	select HAVE_IRQ_TIME_ACCOUNTING
1816471b825SIngo Molnar	select HAVE_KERNEL_BZIP2
1826471b825SIngo Molnar	select HAVE_KERNEL_GZIP
1836471b825SIngo Molnar	select HAVE_KERNEL_LZ4
1846471b825SIngo Molnar	select HAVE_KERNEL_LZMA
1856471b825SIngo Molnar	select HAVE_KERNEL_LZO
1866471b825SIngo Molnar	select HAVE_KERNEL_XZ
1876471b825SIngo Molnar	select HAVE_KPROBES
1886471b825SIngo Molnar	select HAVE_KPROBES_ON_FTRACE
189540adea3SMasami Hiramatsu	select HAVE_FUNCTION_ERROR_INJECTION
1906471b825SIngo Molnar	select HAVE_KRETPROBES
1916471b825SIngo Molnar	select HAVE_KVM
1926471b825SIngo Molnar	select HAVE_LIVEPATCH			if X86_64
1936471b825SIngo Molnar	select HAVE_MEMBLOCK_NODE_MAP
1940102752eSFrederic Weisbecker	select HAVE_MIXED_BREAKPOINTS_REGS
195ee9f8fceSJosh Poimboeuf	select HAVE_MOD_ARCH_SPECIFIC
1969f132f7eSJoel Fernandes (Google)	select HAVE_MOVE_PMD
19742a0bb3fSPetr Mladek	select HAVE_NMI
1986471b825SIngo Molnar	select HAVE_OPROFILE
1996471b825SIngo Molnar	select HAVE_OPTPROBES
2006471b825SIngo Molnar	select HAVE_PCSPKR_PLATFORM
2016471b825SIngo Molnar	select HAVE_PERF_EVENTS
202c01d4323SFrederic Weisbecker	select HAVE_PERF_EVENTS_NMI
20392e5aae4SNicholas Piggin	select HAVE_HARDLOCKUP_DETECTOR_PERF	if PERF_EVENTS && HAVE_PERF_EVENTS_NMI
204eb01d42aSChristoph Hellwig	select HAVE_PCI
205c5e63197SJiri Olsa	select HAVE_PERF_REGS
206c5ebcedbSJiri Olsa	select HAVE_PERF_USER_STACK_DUMP
207ff2e6d72SPeter Zijlstra	select MMU_GATHER_RCU_TABLE_FREE		if PARAVIRT
2086471b825SIngo Molnar	select HAVE_REGS_AND_STACK_ACCESS_API
2096415b38bSJiri Slaby	select HAVE_RELIABLE_STACKTRACE		if X86_64 && (UNWINDER_FRAME_POINTER || UNWINDER_ORC) && STACK_VALIDATION
2103c88ee19SMasami Hiramatsu	select HAVE_FUNCTION_ARG_ACCESS_API
211d148eac0SMasahiro Yamada	select HAVE_STACKPROTECTOR		if CC_HAS_SANE_STACKPROTECTOR
212c763ea26SIngo Molnar	select HAVE_STACK_VALIDATION		if X86_64
213d6761b8fSMathieu Desnoyers	select HAVE_RSEQ
2146471b825SIngo Molnar	select HAVE_SYSCALL_TRACEPOINTS
2156471b825SIngo Molnar	select HAVE_UNSTABLE_SCHED_CLOCK
2167c68af6eSAvi Kivity	select HAVE_USER_RETURN_NOTIFIER
2177ac87074SVincenzo Frascino	select HAVE_GENERIC_VDSO
21805736e4aSThomas Gleixner	select HOTPLUG_SMT			if SMP
219c0185808SThomas Gleixner	select IRQ_FORCED_THREADING
22086596f0aSChristoph Hellwig	select NEED_SG_DMA_LENGTH
2212eac9c2dSChristoph Hellwig	select PCI_DOMAINS			if PCI
222625210cfSSinan Kaya	select PCI_LOCKLESS_CONFIG		if PCI
2236471b825SIngo Molnar	select PERF_EVENTS
2243195ef59SPrarit Bhargava	select RTC_LIB
225d6faca40SArnd Bergmann	select RTC_MC146818_LIB
2266471b825SIngo Molnar	select SPARSE_IRQ
22783fe27eaSPranith Kumar	select SRCU
2286471b825SIngo Molnar	select SYSCTL_EXCEPTION_TRACE
22915f4eae7SAndy Lutomirski	select THREAD_INFO_IN_TASK
2306471b825SIngo Molnar	select USER_STACKTRACE_SUPPORT
2316471b825SIngo Molnar	select VIRT_TO_BUS
2326471b825SIngo Molnar	select X86_FEATURE_NAMES		if PROC_FS
2330c608dadSAubrey Li	select PROC_PID_ARCH_STATUS		if PROC_FS
2349e2b4be3SNayna Jain	imply IMA_SECURE_AND_OR_TRUSTED_BOOT    if EFI
2357d8330a5SBalbir Singh
236ba7e4d13SIngo Molnarconfig INSTRUCTION_DECODER
2373120e25eSJan Beulich	def_bool y
2383120e25eSJan Beulich	depends on KPROBES || PERF_EVENTS || UPROBES
239ba7e4d13SIngo Molnar
24051b26adaSLinus Torvaldsconfig OUTPUT_FORMAT
24151b26adaSLinus Torvalds	string
24251b26adaSLinus Torvalds	default "elf32-i386" if X86_32
24351b26adaSLinus Torvalds	default "elf64-x86-64" if X86_64
24451b26adaSLinus Torvalds
2458d5fffb9SSam Ravnborgconfig LOCKDEP_SUPPORT
2463c2362e6SHarvey Harrison	def_bool y
2478d5fffb9SSam Ravnborg
2488d5fffb9SSam Ravnborgconfig STACKTRACE_SUPPORT
2493c2362e6SHarvey Harrison	def_bool y
2508d5fffb9SSam Ravnborg
2518d5fffb9SSam Ravnborgconfig MMU
2523c2362e6SHarvey Harrison	def_bool y
2538d5fffb9SSam Ravnborg
2549e08f57dSDaniel Cashmanconfig ARCH_MMAP_RND_BITS_MIN
2559e08f57dSDaniel Cashman	default 28 if 64BIT
2569e08f57dSDaniel Cashman	default 8
2579e08f57dSDaniel Cashman
2589e08f57dSDaniel Cashmanconfig ARCH_MMAP_RND_BITS_MAX
2599e08f57dSDaniel Cashman	default 32 if 64BIT
2609e08f57dSDaniel Cashman	default 16
2619e08f57dSDaniel Cashman
2629e08f57dSDaniel Cashmanconfig ARCH_MMAP_RND_COMPAT_BITS_MIN
2639e08f57dSDaniel Cashman	default 8
2649e08f57dSDaniel Cashman
2659e08f57dSDaniel Cashmanconfig ARCH_MMAP_RND_COMPAT_BITS_MAX
2669e08f57dSDaniel Cashman	default 16
2679e08f57dSDaniel Cashman
2688d5fffb9SSam Ravnborgconfig SBUS
2698d5fffb9SSam Ravnborg	bool
2708d5fffb9SSam Ravnborg
2718d5fffb9SSam Ravnborgconfig GENERIC_ISA_DMA
2723120e25eSJan Beulich	def_bool y
2733120e25eSJan Beulich	depends on ISA_DMA_API
2748d5fffb9SSam Ravnborg
2758d5fffb9SSam Ravnborgconfig GENERIC_BUG
2763c2362e6SHarvey Harrison	def_bool y
2778d5fffb9SSam Ravnborg	depends on BUG
278b93a531eSJan Beulich	select GENERIC_BUG_RELATIVE_POINTERS if X86_64
279b93a531eSJan Beulich
280b93a531eSJan Beulichconfig GENERIC_BUG_RELATIVE_POINTERS
281b93a531eSJan Beulich	bool
2828d5fffb9SSam Ravnborg
2838d5fffb9SSam Ravnborgconfig ARCH_MAY_HAVE_PC_FDC
2843120e25eSJan Beulich	def_bool y
2853120e25eSJan Beulich	depends on ISA_DMA_API
2868d5fffb9SSam Ravnborg
2871032c0baSSam Ravnborgconfig GENERIC_CALIBRATE_DELAY
2881032c0baSSam Ravnborg	def_bool y
2891032c0baSSam Ravnborg
2909a0b8415Svenkatesh.pallipadi@intel.comconfig ARCH_HAS_CPU_RELAX
2919a0b8415Svenkatesh.pallipadi@intel.com	def_bool y
2928d5fffb9SSam Ravnborg
2931b27d05bSPekka Enbergconfig ARCH_HAS_CACHE_LINE_SIZE
2941b27d05bSPekka Enberg	def_bool y
2951b27d05bSPekka Enberg
296316d097cSDave Hansenconfig ARCH_HAS_FILTER_PGPROT
297316d097cSDave Hansen	def_bool y
298316d097cSDave Hansen
299dd5af90aSMike Travisconfig HAVE_SETUP_PER_CPU_AREA
30089c9c4c5SBrian Gerst	def_bool y
301b32ef636Stravis@sgi.com
30208fc4580STejun Heoconfig NEED_PER_CPU_EMBED_FIRST_CHUNK
30308fc4580STejun Heo	def_bool y
30408fc4580STejun Heo
30508fc4580STejun Heoconfig NEED_PER_CPU_PAGE_FIRST_CHUNK
30611124411STejun Heo	def_bool y
30711124411STejun Heo
308801e4062SJohannes Bergconfig ARCH_HIBERNATION_POSSIBLE
309801e4062SJohannes Berg	def_bool y
310801e4062SJohannes Berg
311f4cb5700SJohannes Bergconfig ARCH_SUSPEND_POSSIBLE
312f4cb5700SJohannes Berg	def_bool y
313f4cb5700SJohannes Berg
31453313b2cSSteve Capperconfig ARCH_WANT_GENERAL_HUGETLB
31553313b2cSSteve Capper	def_bool y
31653313b2cSSteve Capper
3178d5fffb9SSam Ravnborgconfig ZONE_DMA32
318e0fd24a3SJan Beulich	def_bool y if X86_64
3198d5fffb9SSam Ravnborg
3208d5fffb9SSam Ravnborgconfig AUDIT_ARCH
321e0fd24a3SJan Beulich	def_bool y if X86_64
3228d5fffb9SSam Ravnborg
3236a11f75bSAkinobu Mitaconfig ARCH_SUPPORTS_DEBUG_PAGEALLOC
3246a11f75bSAkinobu Mita	def_bool y
3256a11f75bSAkinobu Mita
326d6f2d75aSAndrey Ryabininconfig KASAN_SHADOW_OFFSET
327d6f2d75aSAndrey Ryabinin	hex
328d6f2d75aSAndrey Ryabinin	depends on KASAN
329d6f2d75aSAndrey Ryabinin	default 0xdffffc0000000000
330d6f2d75aSAndrey Ryabinin
33169575d38SShane Wangconfig HAVE_INTEL_TXT
33269575d38SShane Wang	def_bool y
3336ea30386SKees Cook	depends on INTEL_IOMMU && ACPI
33469575d38SShane Wang
3356b0c3d44SSam Ravnborgconfig X86_32_SMP
3366b0c3d44SSam Ravnborg	def_bool y
3376b0c3d44SSam Ravnborg	depends on X86_32 && SMP
3386b0c3d44SSam Ravnborg
3396b0c3d44SSam Ravnborgconfig X86_64_SMP
3406b0c3d44SSam Ravnborg	def_bool y
3416b0c3d44SSam Ravnborg	depends on X86_64 && SMP
3426b0c3d44SSam Ravnborg
343ccbeed3aSTejun Heoconfig X86_32_LAZY_GS
344ccbeed3aSTejun Heo	def_bool y
3458458f8c2SMasahiro Yamada	depends on X86_32 && !STACKPROTECTOR
346ccbeed3aSTejun Heo
3472b144498SSrikar Dronamrajuconfig ARCH_SUPPORTS_UPROBES
3482b144498SSrikar Dronamraju	def_bool y
3492b144498SSrikar Dronamraju
350d20642f0SRob Herringconfig FIX_EARLYCON_MEM
351d20642f0SRob Herring	def_bool y
352d20642f0SRob Herring
35394d49eb3SKirill A. Shutemovconfig DYNAMIC_PHYSICAL_MASK
35494d49eb3SKirill A. Shutemov	bool
35594d49eb3SKirill A. Shutemov
35698233368SKirill A. Shutemovconfig PGTABLE_LEVELS
35798233368SKirill A. Shutemov	int
35877ef56e4SKirill A. Shutemov	default 5 if X86_5LEVEL
35998233368SKirill A. Shutemov	default 4 if X86_64
36098233368SKirill A. Shutemov	default 3 if X86_PAE
36198233368SKirill A. Shutemov	default 2
36298233368SKirill A. Shutemov
3632a61f474SMasahiro Yamadaconfig CC_HAS_SANE_STACKPROTECTOR
3642a61f474SMasahiro Yamada	bool
3652a61f474SMasahiro Yamada	default $(success,$(srctree)/scripts/gcc-x86_64-has-stack-protector.sh $(CC)) if 64BIT
3662a61f474SMasahiro Yamada	default $(success,$(srctree)/scripts/gcc-x86_32-has-stack-protector.sh $(CC))
3672a61f474SMasahiro Yamada	help
3682a61f474SMasahiro Yamada	   We have to make sure stack protector is unconditionally disabled if
3692a61f474SMasahiro Yamada	   the compiler produces broken code.
3702a61f474SMasahiro Yamada
371506f1d07SSam Ravnborgmenu "Processor type and features"
372506f1d07SSam Ravnborg
3735ee71535SRandy Dunlapconfig ZONE_DMA
3745ee71535SRandy Dunlap	bool "DMA memory allocation support" if EXPERT
3755ee71535SRandy Dunlap	default y
3765ee71535SRandy Dunlap	help
3775ee71535SRandy Dunlap	  DMA memory allocation support allows devices with less than 32-bit
3785ee71535SRandy Dunlap	  addressing to allocate within the first 16MB of address space.
3795ee71535SRandy Dunlap	  Disable if no such devices will be used.
3805ee71535SRandy Dunlap
3815ee71535SRandy Dunlap	  If unsure, say Y.
3825ee71535SRandy Dunlap
383506f1d07SSam Ravnborgconfig SMP
384506f1d07SSam Ravnborg	bool "Symmetric multi-processing support"
385506f1d07SSam Ravnborg	---help---
386506f1d07SSam Ravnborg	  This enables support for systems with more than one CPU. If you have
3874a474157SRobert Graffham	  a system with only one CPU, say N. If you have a system with more
3884a474157SRobert Graffham	  than one CPU, say Y.
389506f1d07SSam Ravnborg
3904a474157SRobert Graffham	  If you say N here, the kernel will run on uni- and multiprocessor
391506f1d07SSam Ravnborg	  machines, but will use only one CPU of a multiprocessor machine. If
392506f1d07SSam Ravnborg	  you say Y here, the kernel will run on many, but not all,
3934a474157SRobert Graffham	  uniprocessor machines. On a uniprocessor machine, the kernel
394506f1d07SSam Ravnborg	  will run faster if you say N here.
395506f1d07SSam Ravnborg
396506f1d07SSam Ravnborg	  Note that if you say Y here and choose architecture "586" or
397506f1d07SSam Ravnborg	  "Pentium" under "Processor family", the kernel will not work on 486
398506f1d07SSam Ravnborg	  architectures. Similarly, multiprocessor kernels for the "PPro"
399506f1d07SSam Ravnborg	  architecture may not work on all Pentium based boards.
400506f1d07SSam Ravnborg
401506f1d07SSam Ravnborg	  People using multiprocessor machines who say Y here should also say
402506f1d07SSam Ravnborg	  Y to "Enhanced Real Time Clock Support", below. The "Advanced Power
403506f1d07SSam Ravnborg	  Management" code will be disabled if you say Y here.
404506f1d07SSam Ravnborg
405cb1aaebeSMauro Carvalho Chehab	  See also <file:Documentation/x86/i386/IO-APIC.rst>,
4064f4cfa6cSMauro Carvalho Chehab	  <file:Documentation/admin-guide/lockup-watchdogs.rst> and the SMP-HOWTO available at
407506f1d07SSam Ravnborg	  <http://www.tldp.org/docs.html#howto>.
408506f1d07SSam Ravnborg
409506f1d07SSam Ravnborg	  If you don't know what to do here, say N.
410506f1d07SSam Ravnborg
4119def39beSJosh Triplettconfig X86_FEATURE_NAMES
4129def39beSJosh Triplett	bool "Processor feature human-readable names" if EMBEDDED
4139def39beSJosh Triplett	default y
4149def39beSJosh Triplett	---help---
4159def39beSJosh Triplett	  This option compiles in a table of x86 feature bits and corresponding
4169def39beSJosh Triplett	  names.  This is required to support /proc/cpuinfo and a few kernel
4179def39beSJosh Triplett	  messages.  You can disable this to save space, at the expense of
4189def39beSJosh Triplett	  making those few kernel messages show numeric feature bits instead.
4199def39beSJosh Triplett
4209def39beSJosh Triplett	  If in doubt, say Y.
4219def39beSJosh Triplett
42206cd9a7dSYinghai Luconfig X86_X2APIC
42306cd9a7dSYinghai Lu	bool "Support x2apic"
42419e3d60dSJan Kiszka	depends on X86_LOCAL_APIC && X86_64 && (IRQ_REMAP || HYPERVISOR_GUEST)
42506cd9a7dSYinghai Lu	---help---
42606cd9a7dSYinghai Lu	  This enables x2apic support on CPUs that have this feature.
42706cd9a7dSYinghai Lu
42806cd9a7dSYinghai Lu	  This allows 32-bit apic IDs (so it can support very large systems),
42906cd9a7dSYinghai Lu	  and accesses the local apic via MSRs not via mmio.
43006cd9a7dSYinghai Lu
43106cd9a7dSYinghai Lu	  If you don't know what to do here, say N.
43206cd9a7dSYinghai Lu
4336695c85bSYinghai Luconfig X86_MPPARSE
4346e87f9b7SBin Gao	bool "Enable MPS table" if ACPI || SFI
4357a527688SJan Beulich	default y
4365ab74722SIngo Molnar	depends on X86_LOCAL_APIC
4378f9ca475SIngo Molnar	---help---
4386695c85bSYinghai Lu	  For old smp systems that do not have proper acpi support. Newer systems
4396695c85bSYinghai Lu	  (esp with 64bit cpus) with acpi support, MADT and DSDT will override it
4406695c85bSYinghai Lu
441ddd70cf9SJun Nakajimaconfig GOLDFISH
442ddd70cf9SJun Nakajima	def_bool y
443ddd70cf9SJun Nakajima	depends on X86_GOLDFISH
444ddd70cf9SJun Nakajima
44576b04384SDavid Woodhouseconfig RETPOLINE
44676b04384SDavid Woodhouse	bool "Avoid speculative indirect branches in kernel"
44776b04384SDavid Woodhouse	default y
448d5028ba8SPeter Zijlstra	select STACK_VALIDATION if HAVE_STACK_VALIDATION
44976b04384SDavid Woodhouse	help
45076b04384SDavid Woodhouse	  Compile kernel with the retpoline compiler options to guard against
45176b04384SDavid Woodhouse	  kernel-to-user data leaks by avoiding speculative indirect
45276b04384SDavid Woodhouse	  branches. Requires a compiler with -mindirect-branch=thunk-extern
45376b04384SDavid Woodhouse	  support for full protection. The kernel may run slower.
45476b04384SDavid Woodhouse
455e6d42931SJohannes Weinerconfig X86_CPU_RESCTRL
456e6d42931SJohannes Weiner	bool "x86 CPU resource control support"
4576fe07ce3SBabu Moger	depends on X86 && (CPU_SUP_INTEL || CPU_SUP_AMD)
45859fe5a77SThomas Gleixner	select KERNFS
459e79f15a4SChen Yu	select PROC_CPU_RESCTRL		if PROC_FS
46078e99b4aSFenghua Yu	help
461e6d42931SJohannes Weiner	  Enable x86 CPU resource control support.
4626fe07ce3SBabu Moger
4636fe07ce3SBabu Moger	  Provide support for the allocation and monitoring of system resources
4646fe07ce3SBabu Moger	  usage by the CPU.
4656fe07ce3SBabu Moger
4666fe07ce3SBabu Moger	  Intel calls this Intel Resource Director Technology
4676fe07ce3SBabu Moger	  (Intel(R) RDT). More information about RDT can be found in the
4686fe07ce3SBabu Moger	  Intel x86 Architecture Software Developer Manual.
4696fe07ce3SBabu Moger
4706fe07ce3SBabu Moger	  AMD calls this AMD Platform Quality of Service (AMD QoS).
4716fe07ce3SBabu Moger	  More information about AMD QoS can be found in the AMD64 Technology
4726fe07ce3SBabu Moger	  Platform Quality of Service Extensions manual.
47378e99b4aSFenghua Yu
47478e99b4aSFenghua Yu	  Say N if unsure.
47578e99b4aSFenghua Yu
4768425091fSRavikiran G Thirumalaiif X86_32
477a0d0bb4dSRandy Dunlapconfig X86_BIGSMP
478a0d0bb4dSRandy Dunlap	bool "Support for big SMP systems with more than 8 CPUs"
479a0d0bb4dSRandy Dunlap	depends on SMP
480a0d0bb4dSRandy Dunlap	---help---
481e133f6eaSRandy Dunlap	  This option is needed for the systems that have more than 8 CPUs.
482a0d0bb4dSRandy Dunlap
483c5c606d9SRavikiran G Thirumalaiconfig X86_EXTENDED_PLATFORM
484c5c606d9SRavikiran G Thirumalai	bool "Support for extended (non-PC) x86 platforms"
485c5c606d9SRavikiran G Thirumalai	default y
4868f9ca475SIngo Molnar	---help---
48706ac8346SIngo Molnar	  If you disable this option then the kernel will only support
48806ac8346SIngo Molnar	  standard PC platforms. (which covers the vast majority of
48906ac8346SIngo Molnar	  systems out there.)
49006ac8346SIngo Molnar
4918425091fSRavikiran G Thirumalai	  If you enable this option then you'll be able to select support
4928425091fSRavikiran G Thirumalai	  for the following (non-PC) 32 bit x86 platforms:
493cb7b8023SBen Hutchings		Goldfish (Android emulator)
4948425091fSRavikiran G Thirumalai		AMD Elan
4958425091fSRavikiran G Thirumalai		RDC R-321x SoC
4968425091fSRavikiran G Thirumalai		SGI 320/540 (Visual Workstation)
49783125a3aSAlessandro Rubini		STA2X11-based (e.g. Northville)
4983f4110a4SThomas Gleixner		Moorestown MID devices
49906ac8346SIngo Molnar
50006ac8346SIngo Molnar	  If you have one of these systems, or if you want to build a
50106ac8346SIngo Molnar	  generic distribution kernel, say Y here - otherwise say N.
5028425091fSRavikiran G Thirumalaiendif
50306ac8346SIngo Molnar
5048425091fSRavikiran G Thirumalaiif X86_64
5058425091fSRavikiran G Thirumalaiconfig X86_EXTENDED_PLATFORM
5068425091fSRavikiran G Thirumalai	bool "Support for extended (non-PC) x86 platforms"
5078425091fSRavikiran G Thirumalai	default y
5088425091fSRavikiran G Thirumalai	---help---
5098425091fSRavikiran G Thirumalai	  If you disable this option then the kernel will only support
5108425091fSRavikiran G Thirumalai	  standard PC platforms. (which covers the vast majority of
5118425091fSRavikiran G Thirumalai	  systems out there.)
5128425091fSRavikiran G Thirumalai
5138425091fSRavikiran G Thirumalai	  If you enable this option then you'll be able to select support
5148425091fSRavikiran G Thirumalai	  for the following (non-PC) 64 bit x86 platforms:
51544b111b5SSteffen Persvold		Numascale NumaChip
5168425091fSRavikiran G Thirumalai		ScaleMP vSMP
5178425091fSRavikiran G Thirumalai		SGI Ultraviolet
5188425091fSRavikiran G Thirumalai
5198425091fSRavikiran G Thirumalai	  If you have one of these systems, or if you want to build a
5208425091fSRavikiran G Thirumalai	  generic distribution kernel, say Y here - otherwise say N.
5218425091fSRavikiran G Thirumalaiendif
522c5c606d9SRavikiran G Thirumalai# This is an alphabetically sorted list of 64 bit extended platforms
523c5c606d9SRavikiran G Thirumalai# Please maintain the alphabetic order if and when there are additions
52444b111b5SSteffen Persvoldconfig X86_NUMACHIP
52544b111b5SSteffen Persvold	bool "Numascale NumaChip"
52644b111b5SSteffen Persvold	depends on X86_64
52744b111b5SSteffen Persvold	depends on X86_EXTENDED_PLATFORM
52844b111b5SSteffen Persvold	depends on NUMA
52944b111b5SSteffen Persvold	depends on SMP
53044b111b5SSteffen Persvold	depends on X86_X2APIC
531f9726bfdSDaniel J Blueman	depends on PCI_MMCONFIG
53244b111b5SSteffen Persvold	---help---
53344b111b5SSteffen Persvold	  Adds support for Numascale NumaChip large-SMP systems. Needed to
53444b111b5SSteffen Persvold	  enable more than ~168 cores.
53544b111b5SSteffen Persvold	  If you don't have one of these, you should say N here.
53603b48632SNick Piggin
5376a48565eSIngo Molnarconfig X86_VSMP
538c5c606d9SRavikiran G Thirumalai	bool "ScaleMP vSMP"
5396276a074SBorislav Petkov	select HYPERVISOR_GUEST
5406a48565eSIngo Molnar	select PARAVIRT
5416a48565eSIngo Molnar	depends on X86_64 && PCI
542c5c606d9SRavikiran G Thirumalai	depends on X86_EXTENDED_PLATFORM
543ead91d4bSShai Fultheim	depends on SMP
5448f9ca475SIngo Molnar	---help---
5456a48565eSIngo Molnar	  Support for ScaleMP vSMP systems.  Say 'Y' here if this kernel is
5466a48565eSIngo Molnar	  supposed to run on these EM64T-based machines.  Only choose this option
5476a48565eSIngo Molnar	  if you have one of these machines.
5486a48565eSIngo Molnar
549c5c606d9SRavikiran G Thirumalaiconfig X86_UV
550c5c606d9SRavikiran G Thirumalai	bool "SGI Ultraviolet"
551c5c606d9SRavikiran G Thirumalai	depends on X86_64
552c5c606d9SRavikiran G Thirumalai	depends on X86_EXTENDED_PLATFORM
55354c28d29SJack Steiner	depends on NUMA
5541ecb4ae5SAndrew Morton	depends on EFI
5559d6c26e7SSuresh Siddha	depends on X86_X2APIC
5561222e564SIngo Molnar	depends on PCI
557c5c606d9SRavikiran G Thirumalai	---help---
558c5c606d9SRavikiran G Thirumalai	  This option is needed in order to support SGI Ultraviolet systems.
559c5c606d9SRavikiran G Thirumalai	  If you don't have one of these, you should say N here.
560c5c606d9SRavikiran G Thirumalai
561c5c606d9SRavikiran G Thirumalai# Following is an alphabetically sorted list of 32 bit extended platforms
562c5c606d9SRavikiran G Thirumalai# Please maintain the alphabetic order if and when there are additions
563506f1d07SSam Ravnborg
564ddd70cf9SJun Nakajimaconfig X86_GOLDFISH
565ddd70cf9SJun Nakajima	bool "Goldfish (Virtual Platform)"
566cb7b8023SBen Hutchings	depends on X86_EXTENDED_PLATFORM
567ddd70cf9SJun Nakajima	---help---
568ddd70cf9SJun Nakajima	 Enable support for the Goldfish virtual platform used primarily
569ddd70cf9SJun Nakajima	 for Android development. Unless you are building for the Android
570ddd70cf9SJun Nakajima	 Goldfish emulator say N here.
571ddd70cf9SJun Nakajima
572c751e17bSThomas Gleixnerconfig X86_INTEL_CE
573c751e17bSThomas Gleixner	bool "CE4100 TV platform"
574c751e17bSThomas Gleixner	depends on PCI
575c751e17bSThomas Gleixner	depends on PCI_GODIRECT
5766084a6e2SJiang Liu	depends on X86_IO_APIC
577c751e17bSThomas Gleixner	depends on X86_32
578c751e17bSThomas Gleixner	depends on X86_EXTENDED_PLATFORM
57937bc9f50SDirk Brandewie	select X86_REBOOTFIXUPS
580da6b737bSSebastian Andrzej Siewior	select OF
581da6b737bSSebastian Andrzej Siewior	select OF_EARLY_FLATTREE
582c751e17bSThomas Gleixner	---help---
583c751e17bSThomas Gleixner	  Select for the Intel CE media processor (CE4100) SOC.
584c751e17bSThomas Gleixner	  This option compiles in support for the CE4100 SOC for settop
585c751e17bSThomas Gleixner	  boxes and media devices.
586c751e17bSThomas Gleixner
5874cb9b00fSDavid Cohenconfig X86_INTEL_MID
58843605ef1SAlan Cox	bool "Intel MID platform support"
58943605ef1SAlan Cox	depends on X86_EXTENDED_PLATFORM
590edc6bc78SDavid Cohen	depends on X86_PLATFORM_DEVICES
5911ea7c673SAlan Cox	depends on PCI
5923fda5bb4SAndy Shevchenko	depends on X86_64 || (PCI_GOANY && X86_32)
5931ea7c673SAlan Cox	depends on X86_IO_APIC
5947c9c3a1eSAlan Cox	select SFI
5954cb9b00fSDavid Cohen	select I2C
5967c9c3a1eSAlan Cox	select DW_APB_TIMER
5971ea7c673SAlan Cox	select APB_TIMER
5981ea7c673SAlan Cox	select INTEL_SCU_IPC
59915a713dfSMika Westerberg	select MFD_INTEL_MSIC
6001ea7c673SAlan Cox	---help---
6014cb9b00fSDavid Cohen	  Select to build a kernel capable of supporting Intel MID (Mobile
6024cb9b00fSDavid Cohen	  Internet Device) platform systems which do not have the PCI legacy
6034cb9b00fSDavid Cohen	  interfaces. If you are building for a PC class system say N here.
6041ea7c673SAlan Cox
6054cb9b00fSDavid Cohen	  Intel MID platforms are based on an Intel processor and chipset which
6064cb9b00fSDavid Cohen	  consume less power than most of the x86 derivatives.
60743605ef1SAlan Cox
6088bbc2a13SBryan O'Donoghueconfig X86_INTEL_QUARK
6098bbc2a13SBryan O'Donoghue	bool "Intel Quark platform support"
6108bbc2a13SBryan O'Donoghue	depends on X86_32
6118bbc2a13SBryan O'Donoghue	depends on X86_EXTENDED_PLATFORM
6128bbc2a13SBryan O'Donoghue	depends on X86_PLATFORM_DEVICES
6138bbc2a13SBryan O'Donoghue	depends on X86_TSC
6148bbc2a13SBryan O'Donoghue	depends on PCI
6158bbc2a13SBryan O'Donoghue	depends on PCI_GOANY
6168bbc2a13SBryan O'Donoghue	depends on X86_IO_APIC
6178bbc2a13SBryan O'Donoghue	select IOSF_MBI
6188bbc2a13SBryan O'Donoghue	select INTEL_IMR
6199ab6eb51SAndy Shevchenko	select COMMON_CLK
6208bbc2a13SBryan O'Donoghue	---help---
6218bbc2a13SBryan O'Donoghue	  Select to include support for Quark X1000 SoC.
6228bbc2a13SBryan O'Donoghue	  Say Y here if you have a Quark based system such as the Arduino
6238bbc2a13SBryan O'Donoghue	  compatible Intel Galileo.
6248bbc2a13SBryan O'Donoghue
6253d48aab1SMika Westerbergconfig X86_INTEL_LPSS
6263d48aab1SMika Westerberg	bool "Intel Low Power Subsystem Support"
6275962dd22SSinan Kaya	depends on X86 && ACPI && PCI
6283d48aab1SMika Westerberg	select COMMON_CLK
6290f531431SMathias Nyman	select PINCTRL
630eebb3e8dSAndy Shevchenko	select IOSF_MBI
6313d48aab1SMika Westerberg	---help---
6323d48aab1SMika Westerberg	  Select to build support for Intel Low Power Subsystem such as
6333d48aab1SMika Westerberg	  found on Intel Lynxpoint PCH. Selecting this option enables
6340f531431SMathias Nyman	  things like clock tree (common clock framework) and pincontrol
6350f531431SMathias Nyman	  which are needed by the LPSS peripheral drivers.
6363d48aab1SMika Westerberg
63792082a88SKen Xueconfig X86_AMD_PLATFORM_DEVICE
63892082a88SKen Xue	bool "AMD ACPI2Platform devices support"
63992082a88SKen Xue	depends on ACPI
64092082a88SKen Xue	select COMMON_CLK
64192082a88SKen Xue	select PINCTRL
64292082a88SKen Xue	---help---
64392082a88SKen Xue	  Select to interpret AMD specific ACPI device to platform device
64492082a88SKen Xue	  such as I2C, UART, GPIO found on AMD Carrizo and later chipsets.
64592082a88SKen Xue	  I2C and UART depend on COMMON_CLK to set clock. GPIO driver is
64692082a88SKen Xue	  implemented under PINCTRL subsystem.
64792082a88SKen Xue
648ced3ce76SDavid E. Boxconfig IOSF_MBI
649ced3ce76SDavid E. Box	tristate "Intel SoC IOSF Sideband support for SoC platforms"
650ced3ce76SDavid E. Box	depends on PCI
651ced3ce76SDavid E. Box	---help---
652ced3ce76SDavid E. Box	  This option enables sideband register access support for Intel SoC
653ced3ce76SDavid E. Box	  platforms. On these platforms the IOSF sideband is used in lieu of
654ced3ce76SDavid E. Box	  MSR's for some register accesses, mostly but not limited to thermal
655ced3ce76SDavid E. Box	  and power. Drivers may query the availability of this device to
656ced3ce76SDavid E. Box	  determine if they need the sideband in order to work on these
657ced3ce76SDavid E. Box	  platforms. The sideband is available on the following SoC products.
658ced3ce76SDavid E. Box	  This list is not meant to be exclusive.
659ced3ce76SDavid E. Box	   - BayTrail
660ced3ce76SDavid E. Box	   - Braswell
661ced3ce76SDavid E. Box	   - Quark
662ced3ce76SDavid E. Box
663ced3ce76SDavid E. Box	  You should say Y if you are running a kernel on one of these SoC's.
664ced3ce76SDavid E. Box
665ed2226bdSDavid E. Boxconfig IOSF_MBI_DEBUG
666ed2226bdSDavid E. Box	bool "Enable IOSF sideband access through debugfs"
667ed2226bdSDavid E. Box	depends on IOSF_MBI && DEBUG_FS
668ed2226bdSDavid E. Box	---help---
669ed2226bdSDavid E. Box	  Select this option to expose the IOSF sideband access registers (MCR,
670ed2226bdSDavid E. Box	  MDR, MCRX) through debugfs to write and read register information from
671ed2226bdSDavid E. Box	  different units on the SoC. This is most useful for obtaining device
672ed2226bdSDavid E. Box	  state information for debug and analysis. As this is a general access
673ed2226bdSDavid E. Box	  mechanism, users of this option would have specific knowledge of the
674ed2226bdSDavid E. Box	  device they want to access.
675ed2226bdSDavid E. Box
676ed2226bdSDavid E. Box	  If you don't require the option or are in doubt, say N.
677ed2226bdSDavid E. Box
678c5c606d9SRavikiran G Thirumalaiconfig X86_RDC321X
679c5c606d9SRavikiran G Thirumalai	bool "RDC R-321x SoC"
680506f1d07SSam Ravnborg	depends on X86_32
681c5c606d9SRavikiran G Thirumalai	depends on X86_EXTENDED_PLATFORM
682c5c606d9SRavikiran G Thirumalai	select M486
683c5c606d9SRavikiran G Thirumalai	select X86_REBOOTFIXUPS
684c5c606d9SRavikiran G Thirumalai	---help---
685c5c606d9SRavikiran G Thirumalai	  This option is needed for RDC R-321x system-on-chip, also known
686c5c606d9SRavikiran G Thirumalai	  as R-8610-(G).
687c5c606d9SRavikiran G Thirumalai	  If you don't have one of these chips, you should say N here.
688c5c606d9SRavikiran G Thirumalai
689e0c7ae37SIngo Molnarconfig X86_32_NON_STANDARD
6909c398017SIngo Molnar	bool "Support non-standard 32-bit SMP architectures"
6919c398017SIngo Molnar	depends on X86_32 && SMP
692c5c606d9SRavikiran G Thirumalai	depends on X86_EXTENDED_PLATFORM
6938f9ca475SIngo Molnar	---help---
694b5660ba7SH. Peter Anvin	  This option compiles in the bigsmp and STA2X11 default
695b5660ba7SH. Peter Anvin	  subarchitectures.  It is intended for a generic binary
696b5660ba7SH. Peter Anvin	  kernel. If you select them all, kernel will probe it one by
697b5660ba7SH. Peter Anvin	  one and will fallback to default.
698d49c4288SYinghai Lu
699c5c606d9SRavikiran G Thirumalai# Alphabetically sorted list of Non standard 32 bit platforms
700d49c4288SYinghai Lu
701d949f36fSLinus Torvaldsconfig X86_SUPPORTS_MEMORY_FAILURE
7026fc108a0SJan Beulich	def_bool y
703d949f36fSLinus Torvalds	# MCE code calls memory_failure():
704d949f36fSLinus Torvalds	depends on X86_MCE
705d949f36fSLinus Torvalds	# On 32-bit this adds too big of NODES_SHIFT and we run out of page flags:
706d949f36fSLinus Torvalds	# On 32-bit SPARSEMEM adds too big of SECTIONS_WIDTH:
707d949f36fSLinus Torvalds	depends on X86_64 || !SPARSEMEM
708d949f36fSLinus Torvalds	select ARCH_SUPPORTS_MEMORY_FAILURE
709d949f36fSLinus Torvalds
71083125a3aSAlessandro Rubiniconfig STA2X11
71183125a3aSAlessandro Rubini	bool "STA2X11 Companion Chip Support"
71283125a3aSAlessandro Rubini	depends on X86_32_NON_STANDARD && PCI
71383125a3aSAlessandro Rubini	select SWIOTLB
71483125a3aSAlessandro Rubini	select MFD_STA2X11
7150145071bSLinus Walleij	select GPIOLIB
71683125a3aSAlessandro Rubini	---help---
71783125a3aSAlessandro Rubini	  This adds support for boards based on the STA2X11 IO-Hub,
71883125a3aSAlessandro Rubini	  a.k.a. "ConneXt". The chip is used in place of the standard
71983125a3aSAlessandro Rubini	  PC chipset, so all "standard" peripherals are missing. If this
72083125a3aSAlessandro Rubini	  option is selected the kernel will still be able to boot on
72183125a3aSAlessandro Rubini	  standard PC machines.
72283125a3aSAlessandro Rubini
72382148d1dSShérabconfig X86_32_IRIS
72482148d1dSShérab	tristate "Eurobraille/Iris poweroff module"
72582148d1dSShérab	depends on X86_32
72682148d1dSShérab	---help---
72782148d1dSShérab	  The Iris machines from EuroBraille do not have APM or ACPI support
72882148d1dSShérab	  to shut themselves down properly.  A special I/O sequence is
72982148d1dSShérab	  needed to do so, which is what this module does at
73082148d1dSShérab	  kernel shutdown.
73182148d1dSShérab
73282148d1dSShérab	  This is only for Iris machines from EuroBraille.
73382148d1dSShérab
73482148d1dSShérab	  If unused, say N.
73582148d1dSShérab
736ae1e9130SIngo Molnarconfig SCHED_OMIT_FRAME_POINTER
7373c2362e6SHarvey Harrison	def_bool y
7383c2362e6SHarvey Harrison	prompt "Single-depth WCHAN output"
739a87d0914SKen Chen	depends on X86
7408f9ca475SIngo Molnar	---help---
741506f1d07SSam Ravnborg	  Calculate simpler /proc/<PID>/wchan values. If this option
742506f1d07SSam Ravnborg	  is disabled then wchan values will recurse back to the
743506f1d07SSam Ravnborg	  caller function. This provides more accurate wchan values,
744506f1d07SSam Ravnborg	  at the expense of slightly more scheduling overhead.
745506f1d07SSam Ravnborg
746506f1d07SSam Ravnborg	  If in doubt, say "Y".
747506f1d07SSam Ravnborg
7486276a074SBorislav Petkovmenuconfig HYPERVISOR_GUEST
7496276a074SBorislav Petkov	bool "Linux guest support"
7508f9ca475SIngo Molnar	---help---
7516276a074SBorislav Petkov	  Say Y here to enable options for running Linux under various hyper-
7526276a074SBorislav Petkov	  visors. This option enables basic hypervisor detection and platform
7536276a074SBorislav Petkov	  setup.
754506f1d07SSam Ravnborg
7556276a074SBorislav Petkov	  If you say N, all options in this submenu will be skipped and
7566276a074SBorislav Petkov	  disabled, and Linux guest support won't be built in.
757506f1d07SSam Ravnborg
7586276a074SBorislav Petkovif HYPERVISOR_GUEST
759506f1d07SSam Ravnborg
760e61bd94aSEduardo Pereira Habkostconfig PARAVIRT
761e61bd94aSEduardo Pereira Habkost	bool "Enable paravirtualization code"
7628f9ca475SIngo Molnar	---help---
763e61bd94aSEduardo Pereira Habkost	  This changes the kernel so it can modify itself when it is run
764e61bd94aSEduardo Pereira Habkost	  under a hypervisor, potentially improving performance significantly
765e61bd94aSEduardo Pereira Habkost	  over full virtualization.  However, when run without a hypervisor
766e61bd94aSEduardo Pereira Habkost	  the kernel is theoretically slower and slightly larger.
767e61bd94aSEduardo Pereira Habkost
768c00a280aSJuergen Grossconfig PARAVIRT_XXL
769c00a280aSJuergen Gross	bool
770c00a280aSJuergen Gross
7716276a074SBorislav Petkovconfig PARAVIRT_DEBUG
7726276a074SBorislav Petkov	bool "paravirt-ops debugging"
7736276a074SBorislav Petkov	depends on PARAVIRT && DEBUG_KERNEL
7746276a074SBorislav Petkov	---help---
7756276a074SBorislav Petkov	  Enable to debug paravirt_ops internals.  Specifically, BUG if
7766276a074SBorislav Petkov	  a paravirt_op is missing when it is called.
7776276a074SBorislav Petkov
778b4ecc126SJeremy Fitzhardingeconfig PARAVIRT_SPINLOCKS
779b4ecc126SJeremy Fitzhardinge	bool "Paravirtualization layer for spinlocks"
7806ea30386SKees Cook	depends on PARAVIRT && SMP
781b4ecc126SJeremy Fitzhardinge	---help---
782b4ecc126SJeremy Fitzhardinge	  Paravirtualized spinlocks allow a pvops backend to replace the
783b4ecc126SJeremy Fitzhardinge	  spinlock implementation with something virtualization-friendly
784b4ecc126SJeremy Fitzhardinge	  (for example, block the virtual CPU rather than spinning).
785b4ecc126SJeremy Fitzhardinge
7864c4e4f61SRaghavendra K T	  It has a minimal impact on native kernels and gives a nice performance
7874c4e4f61SRaghavendra K T	  benefit on paravirtualized KVM / Xen kernels.
788b4ecc126SJeremy Fitzhardinge
7894c4e4f61SRaghavendra K T	  If you are unsure how to answer this question, answer Y.
790b4ecc126SJeremy Fitzhardinge
791ecca2502SZhao Yakuiconfig X86_HV_CALLBACK_VECTOR
792ecca2502SZhao Yakui	def_bool n
793ecca2502SZhao Yakui
7946276a074SBorislav Petkovsource "arch/x86/xen/Kconfig"
7956276a074SBorislav Petkov
7966276a074SBorislav Petkovconfig KVM_GUEST
7976276a074SBorislav Petkov	bool "KVM Guest support (including kvmclock)"
7986276a074SBorislav Petkov	depends on PARAVIRT
7996276a074SBorislav Petkov	select PARAVIRT_CLOCK
800a1c4423bSMarcelo Tosatti	select ARCH_CPUIDLE_HALTPOLL
8016276a074SBorislav Petkov	default y
8026276a074SBorislav Petkov	---help---
8036276a074SBorislav Petkov	  This option enables various optimizations for running under the KVM
8046276a074SBorislav Petkov	  hypervisor. It includes a paravirtualized clock, so that instead
8056276a074SBorislav Petkov	  of relying on a PIT (or probably other) emulation by the
8066276a074SBorislav Petkov	  underlying device model, the host provides the guest with
8076276a074SBorislav Petkov	  timing infrastructure such as time of day, and system time
8086276a074SBorislav Petkov
809a1c4423bSMarcelo Tosatticonfig ARCH_CPUIDLE_HALTPOLL
810a1c4423bSMarcelo Tosatti	def_bool n
811a1c4423bSMarcelo Tosatti	prompt "Disable host haltpoll when loading haltpoll driver"
812a1c4423bSMarcelo Tosatti	help
813a1c4423bSMarcelo Tosatti	  If virtualized under KVM, disable host haltpoll.
814a1c4423bSMarcelo Tosatti
8157733607fSMaran Wilsonconfig PVH
8167733607fSMaran Wilson	bool "Support for running PVH guests"
8177733607fSMaran Wilson	---help---
8187733607fSMaran Wilson	  This option enables the PVH entry point for guest virtual machines
8197733607fSMaran Wilson	  as specified in the x86/HVM direct boot ABI.
8207733607fSMaran Wilson
8211e20eb85SSrivatsa Vaddagiriconfig KVM_DEBUG_FS
8221e20eb85SSrivatsa Vaddagiri	bool "Enable debug information for KVM Guests in debugfs"
8231e20eb85SSrivatsa Vaddagiri	depends on KVM_GUEST && DEBUG_FS
8241e20eb85SSrivatsa Vaddagiri	---help---
8251e20eb85SSrivatsa Vaddagiri	  This option enables collection of various statistics for KVM guest.
8261e20eb85SSrivatsa Vaddagiri	  Statistics are displayed in debugfs filesystem. Enabling this option
8271e20eb85SSrivatsa Vaddagiri	  may incur significant overhead.
8281e20eb85SSrivatsa Vaddagiri
8296276a074SBorislav Petkovconfig PARAVIRT_TIME_ACCOUNTING
8306276a074SBorislav Petkov	bool "Paravirtual steal time accounting"
8316276a074SBorislav Petkov	depends on PARAVIRT
8326276a074SBorislav Petkov	---help---
8336276a074SBorislav Petkov	  Select this option to enable fine granularity task steal time
8346276a074SBorislav Petkov	  accounting. Time spent executing other tasks in parallel with
8356276a074SBorislav Petkov	  the current vCPU is discounted from the vCPU power. To account for
8366276a074SBorislav Petkov	  that, there can be a small performance impact.
8376276a074SBorislav Petkov
8386276a074SBorislav Petkov	  If in doubt, say N here.
8396276a074SBorislav Petkov
8407af192c9SGerd Hoffmannconfig PARAVIRT_CLOCK
8417af192c9SGerd Hoffmann	bool
8427af192c9SGerd Hoffmann
8434a362601SJan Kiszkaconfig JAILHOUSE_GUEST
8444a362601SJan Kiszka	bool "Jailhouse non-root cell support"
845abde587bSArnd Bergmann	depends on X86_64 && PCI
84687e65d05SJan Kiszka	select X86_PM_TIMER
8474a362601SJan Kiszka	---help---
8484a362601SJan Kiszka	  This option allows to run Linux as guest in a Jailhouse non-root
8494a362601SJan Kiszka	  cell. You can leave this option disabled if you only want to start
8504a362601SJan Kiszka	  Jailhouse and run Linux afterwards in the root cell.
8514a362601SJan Kiszka
852ec7972c9SZhao Yakuiconfig ACRN_GUEST
853ec7972c9SZhao Yakui	bool "ACRN Guest support"
854ec7972c9SZhao Yakui	depends on X86_64
855498ad393SZhao Yakui	select X86_HV_CALLBACK_VECTOR
856ec7972c9SZhao Yakui	help
857ec7972c9SZhao Yakui	  This option allows to run Linux as guest in the ACRN hypervisor. ACRN is
858ec7972c9SZhao Yakui	  a flexible, lightweight reference open-source hypervisor, built with
859ec7972c9SZhao Yakui	  real-time and safety-criticality in mind. It is built for embedded
860ec7972c9SZhao Yakui	  IOT with small footprint and real-time features. More details can be
861ec7972c9SZhao Yakui	  found in https://projectacrn.org/.
862ec7972c9SZhao Yakui
8636276a074SBorislav Petkovendif #HYPERVISOR_GUEST
86497349135SJeremy Fitzhardinge
865506f1d07SSam Ravnborgsource "arch/x86/Kconfig.cpu"
866506f1d07SSam Ravnborg
867506f1d07SSam Ravnborgconfig HPET_TIMER
8683c2362e6SHarvey Harrison	def_bool X86_64
869506f1d07SSam Ravnborg	prompt "HPET Timer Support" if X86_32
8708f9ca475SIngo Molnar	---help---
871506f1d07SSam Ravnborg	  Use the IA-PC HPET (High Precision Event Timer) to manage
872506f1d07SSam Ravnborg	  time in preference to the PIT and RTC, if a HPET is
873506f1d07SSam Ravnborg	  present.
874506f1d07SSam Ravnborg	  HPET is the next generation timer replacing legacy 8254s.
875506f1d07SSam Ravnborg	  The HPET provides a stable time base on SMP
876506f1d07SSam Ravnborg	  systems, unlike the TSC, but it is more expensive to access,
8774e7f9df2SMichael S. Tsirkin	  as it is off-chip.  The interface used is documented
8784e7f9df2SMichael S. Tsirkin	  in the HPET spec, revision 1.
879506f1d07SSam Ravnborg
880506f1d07SSam Ravnborg	  You can safely choose Y here.  However, HPET will only be
881506f1d07SSam Ravnborg	  activated if the platform and the BIOS support this feature.
882506f1d07SSam Ravnborg	  Otherwise the 8254 will be used for timing services.
883506f1d07SSam Ravnborg
884506f1d07SSam Ravnborg	  Choose N to continue using the legacy 8254 timer.
885506f1d07SSam Ravnborg
886506f1d07SSam Ravnborgconfig HPET_EMULATE_RTC
8873c2362e6SHarvey Harrison	def_bool y
8889d8af78bSBernhard Walle	depends on HPET_TIMER && (RTC=y || RTC=m || RTC_DRV_CMOS=m || RTC_DRV_CMOS=y)
889506f1d07SSam Ravnborg
890bb24c471SJacob Panconfig APB_TIMER
891933b9463SAlan Cox	def_bool y if X86_INTEL_MID
892933b9463SAlan Cox	prompt "Intel MID APB Timer Support" if X86_INTEL_MID
89306c3df49SJamie Iles	select DW_APB_TIMER
894a0c3832aSAlan Cox	depends on X86_INTEL_MID && SFI
895bb24c471SJacob Pan	help
896bb24c471SJacob Pan	 APB timer is the replacement for 8254, HPET on X86 MID platforms.
897bb24c471SJacob Pan	 The APBT provides a stable time base on SMP
898bb24c471SJacob Pan	 systems, unlike the TSC, but it is more expensive to access,
899bb24c471SJacob Pan	 as it is off-chip. APB timers are always running regardless of CPU
900bb24c471SJacob Pan	 C states, they are used as per CPU clockevent device when possible.
901bb24c471SJacob Pan
9026a108a14SDavid Rientjes# Mark as expert because too many people got it wrong.
903506f1d07SSam Ravnborg# The code disables itself when not needed.
9047ae9392cSThomas Petazzoniconfig DMI
9057ae9392cSThomas Petazzoni	default y
906cf074402SArd Biesheuvel	select DMI_SCAN_MACHINE_NON_EFI_FALLBACK
9076a108a14SDavid Rientjes	bool "Enable DMI scanning" if EXPERT
9088f9ca475SIngo Molnar	---help---
9097ae9392cSThomas Petazzoni	  Enabled scanning of DMI to identify machine quirks. Say Y
9107ae9392cSThomas Petazzoni	  here unless you have verified that your setup is not
9117ae9392cSThomas Petazzoni	  affected by entries in the DMI blacklist. Required by PNP
9127ae9392cSThomas Petazzoni	  BIOS code.
9137ae9392cSThomas Petazzoni
914506f1d07SSam Ravnborgconfig GART_IOMMU
91538901f1cSAndi Kleen	bool "Old AMD GART IOMMU support"
916a4ce5a48SChristoph Hellwig	select IOMMU_HELPER
917506f1d07SSam Ravnborg	select SWIOTLB
91823ac4ae8SAndreas Herrmann	depends on X86_64 && PCI && AMD_NB
9198f9ca475SIngo Molnar	---help---
920ced3c42cSIngo Molnar	  Provides a driver for older AMD Athlon64/Opteron/Turion/Sempron
921ced3c42cSIngo Molnar	  GART based hardware IOMMUs.
922ced3c42cSIngo Molnar
923ced3c42cSIngo Molnar	  The GART supports full DMA access for devices with 32-bit access
924ced3c42cSIngo Molnar	  limitations, on systems with more than 3 GB. This is usually needed
925ced3c42cSIngo Molnar	  for USB, sound, many IDE/SATA chipsets and some other devices.
926ced3c42cSIngo Molnar
927ced3c42cSIngo Molnar	  Newer systems typically have a modern AMD IOMMU, supported via
928ced3c42cSIngo Molnar	  the CONFIG_AMD_IOMMU=y config option.
929ced3c42cSIngo Molnar
930ced3c42cSIngo Molnar	  In normal configurations this driver is only active when needed:
931ced3c42cSIngo Molnar	  there's more than 3 GB of memory and the system contains a
932ced3c42cSIngo Molnar	  32-bit limited device.
933ced3c42cSIngo Molnar
934ced3c42cSIngo Molnar	  If unsure, say Y.
935506f1d07SSam Ravnborg
9361184dc2fSMike Travisconfig MAXSMP
937ddb0c5a6SSamuel Thibault	bool "Enable Maximum number of SMP Processors and NUMA Nodes"
9386ea30386SKees Cook	depends on X86_64 && SMP && DEBUG_KERNEL
93936f5101aSMike Travis	select CPUMASK_OFFSTACK
9408f9ca475SIngo Molnar	---help---
941ddb0c5a6SSamuel Thibault	  Enable maximum number of CPUS and NUMA Nodes for this architecture.
9421184dc2fSMike Travis	  If unsure, say N.
943506f1d07SSam Ravnborg
944aec6487eSIngo Molnar#
945aec6487eSIngo Molnar# The maximum number of CPUs supported:
946aec6487eSIngo Molnar#
947aec6487eSIngo Molnar# The main config value is NR_CPUS, which defaults to NR_CPUS_DEFAULT,
948aec6487eSIngo Molnar# and which can be configured interactively in the
949aec6487eSIngo Molnar# [NR_CPUS_RANGE_BEGIN ... NR_CPUS_RANGE_END] range.
950aec6487eSIngo Molnar#
951aec6487eSIngo Molnar# The ranges are different on 32-bit and 64-bit kernels, depending on
952aec6487eSIngo Molnar# hardware capabilities and scalability features of the kernel.
953aec6487eSIngo Molnar#
954aec6487eSIngo Molnar# ( If MAXSMP is enabled we just use the highest possible value and disable
955aec6487eSIngo Molnar#   interactive configuration. )
956aec6487eSIngo Molnar#
957a0d0bb4dSRandy Dunlap
958aec6487eSIngo Molnarconfig NR_CPUS_RANGE_BEGIN
959a0d0bb4dSRandy Dunlap	int
960aec6487eSIngo Molnar	default NR_CPUS_RANGE_END if MAXSMP
961a0d0bb4dSRandy Dunlap	default    1 if !SMP
962a0d0bb4dSRandy Dunlap	default    2
963a0d0bb4dSRandy Dunlap
964aec6487eSIngo Molnarconfig NR_CPUS_RANGE_END
965a0d0bb4dSRandy Dunlap	int
966a0d0bb4dSRandy Dunlap	depends on X86_32
967aec6487eSIngo Molnar	default   64 if  SMP &&  X86_BIGSMP
968aec6487eSIngo Molnar	default    8 if  SMP && !X86_BIGSMP
969a0d0bb4dSRandy Dunlap	default    1 if !SMP
970a0d0bb4dSRandy Dunlap
971aec6487eSIngo Molnarconfig NR_CPUS_RANGE_END
972a0d0bb4dSRandy Dunlap	int
973a0d0bb4dSRandy Dunlap	depends on X86_64
9741edae1aeSScott Wood	default 8192 if  SMP && CPUMASK_OFFSTACK
9751edae1aeSScott Wood	default  512 if  SMP && !CPUMASK_OFFSTACK
976a0d0bb4dSRandy Dunlap	default    1 if !SMP
977aec6487eSIngo Molnar
978aec6487eSIngo Molnarconfig NR_CPUS_DEFAULT
979aec6487eSIngo Molnar	int
980aec6487eSIngo Molnar	depends on X86_32
981aec6487eSIngo Molnar	default   32 if  X86_BIGSMP
982aec6487eSIngo Molnar	default    8 if  SMP
983aec6487eSIngo Molnar	default    1 if !SMP
984aec6487eSIngo Molnar
985aec6487eSIngo Molnarconfig NR_CPUS_DEFAULT
986aec6487eSIngo Molnar	int
987aec6487eSIngo Molnar	depends on X86_64
988a0d0bb4dSRandy Dunlap	default 8192 if  MAXSMP
989a0d0bb4dSRandy Dunlap	default   64 if  SMP
990aec6487eSIngo Molnar	default    1 if !SMP
991a0d0bb4dSRandy Dunlap
992506f1d07SSam Ravnborgconfig NR_CPUS
99336f5101aSMike Travis	int "Maximum number of CPUs" if SMP && !MAXSMP
994aec6487eSIngo Molnar	range NR_CPUS_RANGE_BEGIN NR_CPUS_RANGE_END
995aec6487eSIngo Molnar	default NR_CPUS_DEFAULT
9968f9ca475SIngo Molnar	---help---
997506f1d07SSam Ravnborg	  This allows you to specify the maximum number of CPUs which this
998bb61ccc7SJosh Boyer	  kernel will support.  If CPUMASK_OFFSTACK is enabled, the maximum
999cad14bb9SKirill A. Shutemov	  supported value is 8192, otherwise the maximum value is 512.  The
1000506f1d07SSam Ravnborg	  minimum value which makes sense is 2.
1001506f1d07SSam Ravnborg
1002aec6487eSIngo Molnar	  This is purely to save memory: each supported CPU adds about 8KB
1003aec6487eSIngo Molnar	  to the kernel image.
1004506f1d07SSam Ravnborg
1005506f1d07SSam Ravnborgconfig SCHED_SMT
1006dbe73364SThomas Gleixner	def_bool y if SMP
1007506f1d07SSam Ravnborg
1008506f1d07SSam Ravnborgconfig SCHED_MC
10093c2362e6SHarvey Harrison	def_bool y
10103c2362e6SHarvey Harrison	prompt "Multi-core scheduler support"
1011c8e56d20SBorislav Petkov	depends on SMP
10128f9ca475SIngo Molnar	---help---
1013506f1d07SSam Ravnborg	  Multi-core scheduler support improves the CPU scheduler's decision
1014506f1d07SSam Ravnborg	  making when dealing with multi-core CPU chips at a cost of slightly
1015506f1d07SSam Ravnborg	  increased overhead in some places. If unsure say N here.
1016506f1d07SSam Ravnborg
1017de966cf4STim Chenconfig SCHED_MC_PRIO
1018de966cf4STim Chen	bool "CPU core priorities scheduler support"
10190a21fc12SIngo Molnar	depends on SCHED_MC && CPU_SUP_INTEL
10200a21fc12SIngo Molnar	select X86_INTEL_PSTATE
10210a21fc12SIngo Molnar	select CPU_FREQ
1022de966cf4STim Chen	default y
10235e76b2abSTim Chen	---help---
1024de966cf4STim Chen	  Intel Turbo Boost Max Technology 3.0 enabled CPUs have a
1025de966cf4STim Chen	  core ordering determined at manufacturing time, which allows
1026de966cf4STim Chen	  certain cores to reach higher turbo frequencies (when running
1027de966cf4STim Chen	  single threaded workloads) than others.
1028de966cf4STim Chen
1029de966cf4STim Chen	  Enabling this kernel feature teaches the scheduler about
1030de966cf4STim Chen	  the TBM3 (aka ITMT) priority order of the CPU cores and adjusts the
1031de966cf4STim Chen	  scheduler's CPU selection logic accordingly, so that higher
1032de966cf4STim Chen	  overall system performance can be achieved.
1033de966cf4STim Chen
1034de966cf4STim Chen	  This feature will have no effect on CPUs without this feature.
1035de966cf4STim Chen
1036de966cf4STim Chen	  If unsure say Y here.
10375e76b2abSTim Chen
103830b8b006SThomas Gleixnerconfig UP_LATE_INIT
103930b8b006SThomas Gleixner	def_bool y
1040ba360f88SThomas Gleixner	depends on !SMP && X86_LOCAL_APIC
104130b8b006SThomas Gleixner
1042506f1d07SSam Ravnborgconfig X86_UP_APIC
104350849eefSJan Beulich	bool "Local APIC support on uniprocessors" if !PCI_MSI
104450849eefSJan Beulich	default PCI_MSI
104538a1dfdaSBryan O'Donoghue	depends on X86_32 && !SMP && !X86_32_NON_STANDARD
10468f9ca475SIngo Molnar	---help---
1047506f1d07SSam Ravnborg	  A local APIC (Advanced Programmable Interrupt Controller) is an
1048506f1d07SSam Ravnborg	  integrated interrupt controller in the CPU. If you have a single-CPU
1049506f1d07SSam Ravnborg	  system which has a processor with a local APIC, you can say Y here to
1050506f1d07SSam Ravnborg	  enable and use it. If you say Y here even though your machine doesn't
1051506f1d07SSam Ravnborg	  have a local APIC, then the kernel will still run with no slowdown at
1052506f1d07SSam Ravnborg	  all. The local APIC supports CPU-generated self-interrupts (timer,
1053506f1d07SSam Ravnborg	  performance counters), and the NMI watchdog which detects hard
1054506f1d07SSam Ravnborg	  lockups.
1055506f1d07SSam Ravnborg
1056506f1d07SSam Ravnborgconfig X86_UP_IOAPIC
1057506f1d07SSam Ravnborg	bool "IO-APIC support on uniprocessors"
1058506f1d07SSam Ravnborg	depends on X86_UP_APIC
10598f9ca475SIngo Molnar	---help---
1060506f1d07SSam Ravnborg	  An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an
1061506f1d07SSam Ravnborg	  SMP-capable replacement for PC-style interrupt controllers. Most
1062506f1d07SSam Ravnborg	  SMP systems and many recent uniprocessor systems have one.
1063506f1d07SSam Ravnborg
1064506f1d07SSam Ravnborg	  If you have a single-CPU system with an IO-APIC, you can say Y here
1065506f1d07SSam Ravnborg	  to use it. If you say Y here even though your machine doesn't have
1066506f1d07SSam Ravnborg	  an IO-APIC, then the kernel will still run with no slowdown at all.
1067506f1d07SSam Ravnborg
1068506f1d07SSam Ravnborgconfig X86_LOCAL_APIC
10693c2362e6SHarvey Harrison	def_bool y
10700dbc6078SThomas Petazzoni	depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC || PCI_MSI
1071b5dc8e6cSJiang Liu	select IRQ_DOMAIN_HIERARCHY
107252f518a3SJiang Liu	select PCI_MSI_IRQ_DOMAIN if PCI_MSI
1073506f1d07SSam Ravnborg
1074506f1d07SSam Ravnborgconfig X86_IO_APIC
1075b1da1e71SJan Beulich	def_bool y
1076b1da1e71SJan Beulich	depends on X86_LOCAL_APIC || X86_UP_IOAPIC
1077506f1d07SSam Ravnborg
107841b9eb26SStefan Assmannconfig X86_REROUTE_FOR_BROKEN_BOOT_IRQS
107941b9eb26SStefan Assmann	bool "Reroute for broken boot IRQs"
108041b9eb26SStefan Assmann	depends on X86_IO_APIC
10818f9ca475SIngo Molnar	---help---
108241b9eb26SStefan Assmann	  This option enables a workaround that fixes a source of
108341b9eb26SStefan Assmann	  spurious interrupts. This is recommended when threaded
108441b9eb26SStefan Assmann	  interrupt handling is used on systems where the generation of
108541b9eb26SStefan Assmann	  superfluous "boot interrupts" cannot be disabled.
108641b9eb26SStefan Assmann
108741b9eb26SStefan Assmann	  Some chipsets generate a legacy INTx "boot IRQ" when the IRQ
108841b9eb26SStefan Assmann	  entry in the chipset's IO-APIC is masked (as, e.g. the RT
108941b9eb26SStefan Assmann	  kernel does during interrupt handling). On chipsets where this
109041b9eb26SStefan Assmann	  boot IRQ generation cannot be disabled, this workaround keeps
109141b9eb26SStefan Assmann	  the original IRQ line masked so that only the equivalent "boot
109241b9eb26SStefan Assmann	  IRQ" is delivered to the CPUs. The workaround also tells the
109341b9eb26SStefan Assmann	  kernel to set up the IRQ handler on the boot IRQ line. In this
109441b9eb26SStefan Assmann	  way only one interrupt is delivered to the kernel. Otherwise
109541b9eb26SStefan Assmann	  the spurious second interrupt may cause the kernel to bring
109641b9eb26SStefan Assmann	  down (vital) interrupt lines.
109741b9eb26SStefan Assmann
109841b9eb26SStefan Assmann	  Only affects "broken" chipsets. Interrupt sharing may be
109941b9eb26SStefan Assmann	  increased on these systems.
110041b9eb26SStefan Assmann
1101506f1d07SSam Ravnborgconfig X86_MCE
1102bab9bc65SAndi Kleen	bool "Machine Check / overheating reporting"
1103648ed940SChen, Gong	select GENERIC_ALLOCATOR
1104e57dbaf7SBorislav Petkov	default y
1105506f1d07SSam Ravnborg	---help---
1106bab9bc65SAndi Kleen	  Machine Check support allows the processor to notify the
1107bab9bc65SAndi Kleen	  kernel if it detects a problem (e.g. overheating, data corruption).
1108506f1d07SSam Ravnborg	  The action the kernel takes depends on the severity of the problem,
1109bab9bc65SAndi Kleen	  ranging from warning messages to halting the machine.
11104efc0670SAndi Kleen
11115de97c9fSTony Luckconfig X86_MCELOG_LEGACY
11125de97c9fSTony Luck	bool "Support for deprecated /dev/mcelog character device"
11135de97c9fSTony Luck	depends on X86_MCE
11145de97c9fSTony Luck	---help---
11155de97c9fSTony Luck	  Enable support for /dev/mcelog which is needed by the old mcelog
11165de97c9fSTony Luck	  userspace logging daemon. Consider switching to the new generation
11175de97c9fSTony Luck	  rasdaemon solution.
11185de97c9fSTony Luck
1119506f1d07SSam Ravnborgconfig X86_MCE_INTEL
11203c2362e6SHarvey Harrison	def_bool y
11213c2362e6SHarvey Harrison	prompt "Intel MCE features"
1122c1ebf835SAndi Kleen	depends on X86_MCE && X86_LOCAL_APIC
11238f9ca475SIngo Molnar	---help---
1124506f1d07SSam Ravnborg	   Additional support for intel specific MCE features such as
1125506f1d07SSam Ravnborg	   the thermal monitor.
1126506f1d07SSam Ravnborg
1127506f1d07SSam Ravnborgconfig X86_MCE_AMD
11283c2362e6SHarvey Harrison	def_bool y
11293c2362e6SHarvey Harrison	prompt "AMD MCE features"
1130f5382de9SYazen Ghannam	depends on X86_MCE && X86_LOCAL_APIC && AMD_NB
11318f9ca475SIngo Molnar	---help---
1132506f1d07SSam Ravnborg	   Additional support for AMD specific MCE features such as
1133506f1d07SSam Ravnborg	   the DRAM Error Threshold.
1134506f1d07SSam Ravnborg
11354efc0670SAndi Kleenconfig X86_ANCIENT_MCE
11366fc108a0SJan Beulich	bool "Support for old Pentium 5 / WinChip machine checks"
1137c31d9633SAndi Kleen	depends on X86_32 && X86_MCE
11384efc0670SAndi Kleen	---help---
11394efc0670SAndi Kleen	  Include support for machine check handling on old Pentium 5 or WinChip
11405065a706SMasanari Iida	  systems. These typically need to be enabled explicitly on the command
11414efc0670SAndi Kleen	  line.
11424efc0670SAndi Kleen
1143b2762686SAndi Kleenconfig X86_MCE_THRESHOLD
1144b2762686SAndi Kleen	depends on X86_MCE_AMD || X86_MCE_INTEL
11456fc108a0SJan Beulich	def_bool y
1146b2762686SAndi Kleen
1147ea149b36SAndi Kleenconfig X86_MCE_INJECT
1148bc8e80d5SBorislav Petkov	depends on X86_MCE && X86_LOCAL_APIC && DEBUG_FS
1149ea149b36SAndi Kleen	tristate "Machine check injector support"
1150ea149b36SAndi Kleen	---help---
1151ea149b36SAndi Kleen	  Provide support for injecting machine checks for testing purposes.
1152ea149b36SAndi Kleen	  If you don't know what a machine check is and you don't do kernel
1153ea149b36SAndi Kleen	  QA it is safe to say n.
1154ea149b36SAndi Kleen
11554efc0670SAndi Kleenconfig X86_THERMAL_VECTOR
11564efc0670SAndi Kleen	def_bool y
11575bb38adcSAndi Kleen	depends on X86_MCE_INTEL
11584efc0670SAndi Kleen
115907dc900eSPeter Zijlstrasource "arch/x86/events/Kconfig"
1160e633c65aSKan Liang
11615aef51c3SAndy Lutomirskiconfig X86_LEGACY_VM86
11621e642812SIngo Molnar	bool "Legacy VM86 support"
1163506f1d07SSam Ravnborg	depends on X86_32
11648f9ca475SIngo Molnar	---help---
11655aef51c3SAndy Lutomirski	  This option allows user programs to put the CPU into V8086
11665aef51c3SAndy Lutomirski	  mode, which is an 80286-era approximation of 16-bit real mode.
11675aef51c3SAndy Lutomirski
11685aef51c3SAndy Lutomirski	  Some very old versions of X and/or vbetool require this option
11695aef51c3SAndy Lutomirski	  for user mode setting.  Similarly, DOSEMU will use it if
11705aef51c3SAndy Lutomirski	  available to accelerate real mode DOS programs.  However, any
11715aef51c3SAndy Lutomirski	  recent version of DOSEMU, X, or vbetool should be fully
11725aef51c3SAndy Lutomirski	  functional even without kernel VM86 support, as they will all
11731e642812SIngo Molnar	  fall back to software emulation. Nevertheless, if you are using
11741e642812SIngo Molnar	  a 16-bit DOS program where 16-bit performance matters, vm86
11751e642812SIngo Molnar	  mode might be faster than emulation and you might want to
11761e642812SIngo Molnar	  enable this option.
11775aef51c3SAndy Lutomirski
11781e642812SIngo Molnar	  Note that any app that works on a 64-bit kernel is unlikely to
11791e642812SIngo Molnar	  need this option, as 64-bit kernels don't, and can't, support
11801e642812SIngo Molnar	  V8086 mode. This option is also unrelated to 16-bit protected
11811e642812SIngo Molnar	  mode and is not needed to run most 16-bit programs under Wine.
11825aef51c3SAndy Lutomirski
11831e642812SIngo Molnar	  Enabling this option increases the complexity of the kernel
11841e642812SIngo Molnar	  and slows down exception handling a tiny bit.
11855aef51c3SAndy Lutomirski
11861e642812SIngo Molnar	  If unsure, say N here.
11875aef51c3SAndy Lutomirski
11885aef51c3SAndy Lutomirskiconfig VM86
11895aef51c3SAndy Lutomirski	bool
11905aef51c3SAndy Lutomirski	default X86_LEGACY_VM86
119134273f41SH. Peter Anvin
119234273f41SH. Peter Anvinconfig X86_16BIT
119334273f41SH. Peter Anvin	bool "Enable support for 16-bit segments" if EXPERT
119434273f41SH. Peter Anvin	default y
1195a5b9e5a2SAndy Lutomirski	depends on MODIFY_LDT_SYSCALL
119634273f41SH. Peter Anvin	---help---
119734273f41SH. Peter Anvin	  This option is required by programs like Wine to run 16-bit
119834273f41SH. Peter Anvin	  protected mode legacy code on x86 processors.  Disabling
119934273f41SH. Peter Anvin	  this option saves about 300 bytes on i386, or around 6K text
120034273f41SH. Peter Anvin	  plus 16K runtime memory on x86-64,
120134273f41SH. Peter Anvin
120234273f41SH. Peter Anvinconfig X86_ESPFIX32
120334273f41SH. Peter Anvin	def_bool y
120434273f41SH. Peter Anvin	depends on X86_16BIT && X86_32
1205506f1d07SSam Ravnborg
1206197725deSH. Peter Anvinconfig X86_ESPFIX64
1207197725deSH. Peter Anvin	def_bool y
120834273f41SH. Peter Anvin	depends on X86_16BIT && X86_64
1209506f1d07SSam Ravnborg
12101ad83c85SAndy Lutomirskiconfig X86_VSYSCALL_EMULATION
12111ad83c85SAndy Lutomirski	bool "Enable vsyscall emulation" if EXPERT
12121ad83c85SAndy Lutomirski	default y
12131ad83c85SAndy Lutomirski	depends on X86_64
12141ad83c85SAndy Lutomirski	---help---
12151ad83c85SAndy Lutomirski	 This enables emulation of the legacy vsyscall page.  Disabling
12161ad83c85SAndy Lutomirski	 it is roughly equivalent to booting with vsyscall=none, except
12171ad83c85SAndy Lutomirski	 that it will also disable the helpful warning if a program
12181ad83c85SAndy Lutomirski	 tries to use a vsyscall.  With this option set to N, offending
12191ad83c85SAndy Lutomirski	 programs will just segfault, citing addresses of the form
12201ad83c85SAndy Lutomirski	 0xffffffffff600?00.
12211ad83c85SAndy Lutomirski
12221ad83c85SAndy Lutomirski	 This option is required by many programs built before 2013, and
12231ad83c85SAndy Lutomirski	 care should be used even with newer programs if set to N.
12241ad83c85SAndy Lutomirski
12251ad83c85SAndy Lutomirski	 Disabling this option saves about 7K of kernel size and
12261ad83c85SAndy Lutomirski	 possibly 4K of additional runtime pagetable memory.
12271ad83c85SAndy Lutomirski
1228111e7b15SThomas Gleixnerconfig X86_IOPL_IOPERM
1229111e7b15SThomas Gleixner	bool "IOPERM and IOPL Emulation"
1230a24ca997SThomas Gleixner	default y
1231c8137aceSThomas Gleixner	---help---
1232111e7b15SThomas Gleixner	  This enables the ioperm() and iopl() syscalls which are necessary
1233111e7b15SThomas Gleixner	  for legacy applications.
1234111e7b15SThomas Gleixner
1235c8137aceSThomas Gleixner	  Legacy IOPL support is an overbroad mechanism which allows user
1236c8137aceSThomas Gleixner	  space aside of accessing all 65536 I/O ports also to disable
1237c8137aceSThomas Gleixner	  interrupts. To gain this access the caller needs CAP_SYS_RAWIO
1238c8137aceSThomas Gleixner	  capabilities and permission from potentially active security
1239c8137aceSThomas Gleixner	  modules.
1240c8137aceSThomas Gleixner
1241c8137aceSThomas Gleixner	  The emulation restricts the functionality of the syscall to
1242c8137aceSThomas Gleixner	  only allowing the full range I/O port access, but prevents the
1243a24ca997SThomas Gleixner	  ability to disable interrupts from user space which would be
1244a24ca997SThomas Gleixner	  granted if the hardware IOPL mechanism would be used.
1245c8137aceSThomas Gleixner
1246506f1d07SSam Ravnborgconfig TOSHIBA
1247506f1d07SSam Ravnborg	tristate "Toshiba Laptop support"
1248506f1d07SSam Ravnborg	depends on X86_32
1249506f1d07SSam Ravnborg	---help---
1250506f1d07SSam Ravnborg	  This adds a driver to safely access the System Management Mode of
1251506f1d07SSam Ravnborg	  the CPU on Toshiba portables with a genuine Toshiba BIOS. It does
1252506f1d07SSam Ravnborg	  not work on models with a Phoenix BIOS. The System Management Mode
1253506f1d07SSam Ravnborg	  is used to set the BIOS and power saving options on Toshiba portables.
1254506f1d07SSam Ravnborg
1255506f1d07SSam Ravnborg	  For information on utilities to make use of this driver see the
1256506f1d07SSam Ravnborg	  Toshiba Linux utilities web site at:
1257506f1d07SSam Ravnborg	  <http://www.buzzard.org.uk/toshiba/>.
1258506f1d07SSam Ravnborg
1259506f1d07SSam Ravnborg	  Say Y if you intend to run this kernel on a Toshiba portable.
1260506f1d07SSam Ravnborg	  Say N otherwise.
1261506f1d07SSam Ravnborg
1262506f1d07SSam Ravnborgconfig I8K
1263039ae585SPali Rohár	tristate "Dell i8k legacy laptop support"
1264949a9d70SJean Delvare	select HWMON
1265039ae585SPali Rohár	select SENSORS_DELL_SMM
1266506f1d07SSam Ravnborg	---help---
1267039ae585SPali Rohár	  This option enables legacy /proc/i8k userspace interface in hwmon
1268039ae585SPali Rohár	  dell-smm-hwmon driver. Character file /proc/i8k reports bios version,
1269039ae585SPali Rohár	  temperature and allows controlling fan speeds of Dell laptops via
1270039ae585SPali Rohár	  System Management Mode. For old Dell laptops (like Dell Inspiron 8000)
1271039ae585SPali Rohár	  it reports also power and hotkey status. For fan speed control is
1272039ae585SPali Rohár	  needed userspace package i8kutils.
1273506f1d07SSam Ravnborg
1274039ae585SPali Rohár	  Say Y if you intend to run this kernel on old Dell laptops or want to
1275039ae585SPali Rohár	  use userspace package i8kutils.
1276506f1d07SSam Ravnborg	  Say N otherwise.
1277506f1d07SSam Ravnborg
1278506f1d07SSam Ravnborgconfig X86_REBOOTFIXUPS
12799ba16087SJan Beulich	bool "Enable X86 board specific fixups for reboot"
12809ba16087SJan Beulich	depends on X86_32
1281506f1d07SSam Ravnborg	---help---
1282506f1d07SSam Ravnborg	  This enables chipset and/or board specific fixups to be done
1283506f1d07SSam Ravnborg	  in order to get reboot to work correctly. This is only needed on
1284506f1d07SSam Ravnborg	  some combinations of hardware and BIOS. The symptom, for which
1285506f1d07SSam Ravnborg	  this config is intended, is when reboot ends with a stalled/hung
1286506f1d07SSam Ravnborg	  system.
1287506f1d07SSam Ravnborg
1288506f1d07SSam Ravnborg	  Currently, the only fixup is for the Geode machines using
12895e3a77e9SFlorian Fainelli	  CS5530A and CS5536 chipsets and the RDC R-321x SoC.
1290506f1d07SSam Ravnborg
1291506f1d07SSam Ravnborg	  Say Y if you want to enable the fixup. Currently, it's safe to
1292506f1d07SSam Ravnborg	  enable this option even if you don't need it.
1293506f1d07SSam Ravnborg	  Say N otherwise.
1294506f1d07SSam Ravnborg
1295506f1d07SSam Ravnborgconfig MICROCODE
12969a2bc335SBorislav Petkov	bool "CPU microcode loading support"
12979a2bc335SBorislav Petkov	default y
129880030e3dSBorislav Petkov	depends on CPU_SUP_AMD || CPU_SUP_INTEL
1299506f1d07SSam Ravnborg	select FW_LOADER
1300506f1d07SSam Ravnborg	---help---
1301506f1d07SSam Ravnborg	  If you say Y here, you will be able to update the microcode on
13025f9c01aaSBorislav Petkov	  Intel and AMD processors. The Intel support is for the IA32 family,
13035f9c01aaSBorislav Petkov	  e.g. Pentium Pro, Pentium II, Pentium III, Pentium 4, Xeon etc. The
13045f9c01aaSBorislav Petkov	  AMD support is for families 0x10 and later. You will obviously need
13055f9c01aaSBorislav Petkov	  the actual microcode binary data itself which is not shipped with
13065f9c01aaSBorislav Petkov	  the Linux kernel.
1307506f1d07SSam Ravnborg
13085f9c01aaSBorislav Petkov	  The preferred method to load microcode from a detached initrd is described
1309cb1aaebeSMauro Carvalho Chehab	  in Documentation/x86/microcode.rst. For that you need to enable
13105f9c01aaSBorislav Petkov	  CONFIG_BLK_DEV_INITRD in order for the loader to be able to scan the
13115f9c01aaSBorislav Petkov	  initrd for microcode blobs.
1312506f1d07SSam Ravnborg
1313c508c46eSBenjamin Gilbert	  In addition, you can build the microcode into the kernel. For that you
1314c508c46eSBenjamin Gilbert	  need to add the vendor-supplied microcode to the CONFIG_EXTRA_FIRMWARE
1315c508c46eSBenjamin Gilbert	  config option.
1316506f1d07SSam Ravnborg
13178d86f390SPeter Orubaconfig MICROCODE_INTEL
1318e43f6e67SBorislav Petkov	bool "Intel microcode loading support"
13198d86f390SPeter Oruba	depends on MICROCODE
13208d86f390SPeter Oruba	default MICROCODE
13218d86f390SPeter Oruba	select FW_LOADER
13228f9ca475SIngo Molnar	---help---
13238d86f390SPeter Oruba	  This options enables microcode patch loading support for Intel
13248d86f390SPeter Oruba	  processors.
13258d86f390SPeter Oruba
1326b8989db9SAlan	  For the current Intel microcode data package go to
1327b8989db9SAlan	  <https://downloadcenter.intel.com> and search for
1328b8989db9SAlan	  'Linux Processor Microcode Data File'.
13298d86f390SPeter Oruba
133080cc9f10SPeter Orubaconfig MICROCODE_AMD
1331e43f6e67SBorislav Petkov	bool "AMD microcode loading support"
133280cc9f10SPeter Oruba	depends on MICROCODE
133380cc9f10SPeter Oruba	select FW_LOADER
13348f9ca475SIngo Molnar	---help---
133580cc9f10SPeter Oruba	  If you select this option, microcode patch loading support for AMD
133680cc9f10SPeter Oruba	  processors will be enabled.
133780cc9f10SPeter Oruba
1338506f1d07SSam Ravnborgconfig MICROCODE_OLD_INTERFACE
1339c02f48e0SBorislav Petkov	bool "Ancient loading interface (DEPRECATED)"
1340c02f48e0SBorislav Petkov	default n
1341506f1d07SSam Ravnborg	depends on MICROCODE
1342c02f48e0SBorislav Petkov	---help---
1343c02f48e0SBorislav Petkov	  DO NOT USE THIS! This is the ancient /dev/cpu/microcode interface
1344c02f48e0SBorislav Petkov	  which was used by userspace tools like iucode_tool and microcode.ctl.
1345c02f48e0SBorislav Petkov	  It is inadequate because it runs too late to be able to properly
1346c02f48e0SBorislav Petkov	  load microcode on a machine and it needs special tools. Instead, you
1347c02f48e0SBorislav Petkov	  should've switched to the early loading method with the initrd or
1348cb1aaebeSMauro Carvalho Chehab	  builtin microcode by now: Documentation/x86/microcode.rst
1349506f1d07SSam Ravnborg
1350506f1d07SSam Ravnborgconfig X86_MSR
1351506f1d07SSam Ravnborg	tristate "/dev/cpu/*/msr - Model-specific register support"
13528f9ca475SIngo Molnar	---help---
1353506f1d07SSam Ravnborg	  This device gives privileged processes access to the x86
1354506f1d07SSam Ravnborg	  Model-Specific Registers (MSRs).  It is a character device with
1355506f1d07SSam Ravnborg	  major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr.
1356506f1d07SSam Ravnborg	  MSR accesses are directed to a specific CPU on multi-processor
1357506f1d07SSam Ravnborg	  systems.
1358506f1d07SSam Ravnborg
1359506f1d07SSam Ravnborgconfig X86_CPUID
1360506f1d07SSam Ravnborg	tristate "/dev/cpu/*/cpuid - CPU information support"
13618f9ca475SIngo Molnar	---help---
1362506f1d07SSam Ravnborg	  This device gives processes access to the x86 CPUID instruction to
1363506f1d07SSam Ravnborg	  be executed on a specific processor.  It is a character device
1364506f1d07SSam Ravnborg	  with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to
1365506f1d07SSam Ravnborg	  /dev/cpu/31/cpuid.
1366506f1d07SSam Ravnborg
1367506f1d07SSam Ravnborgchoice
1368506f1d07SSam Ravnborg	prompt "High Memory Support"
13696fc108a0SJan Beulich	default HIGHMEM4G
1370506f1d07SSam Ravnborg	depends on X86_32
1371506f1d07SSam Ravnborg
1372506f1d07SSam Ravnborgconfig NOHIGHMEM
1373506f1d07SSam Ravnborg	bool "off"
1374506f1d07SSam Ravnborg	---help---
1375506f1d07SSam Ravnborg	  Linux can use up to 64 Gigabytes of physical memory on x86 systems.
1376506f1d07SSam Ravnborg	  However, the address space of 32-bit x86 processors is only 4
1377506f1d07SSam Ravnborg	  Gigabytes large. That means that, if you have a large amount of
1378506f1d07SSam Ravnborg	  physical memory, not all of it can be "permanently mapped" by the
1379506f1d07SSam Ravnborg	  kernel. The physical memory that's not permanently mapped is called
1380506f1d07SSam Ravnborg	  "high memory".
1381506f1d07SSam Ravnborg
1382506f1d07SSam Ravnborg	  If you are compiling a kernel which will never run on a machine with
1383506f1d07SSam Ravnborg	  more than 1 Gigabyte total physical RAM, answer "off" here (default
1384506f1d07SSam Ravnborg	  choice and suitable for most users). This will result in a "3GB/1GB"
1385506f1d07SSam Ravnborg	  split: 3GB are mapped so that each process sees a 3GB virtual memory
1386506f1d07SSam Ravnborg	  space and the remaining part of the 4GB virtual memory space is used
1387506f1d07SSam Ravnborg	  by the kernel to permanently map as much physical memory as
1388506f1d07SSam Ravnborg	  possible.
1389506f1d07SSam Ravnborg
1390506f1d07SSam Ravnborg	  If the machine has between 1 and 4 Gigabytes physical RAM, then
1391506f1d07SSam Ravnborg	  answer "4GB" here.
1392506f1d07SSam Ravnborg
1393506f1d07SSam Ravnborg	  If more than 4 Gigabytes is used then answer "64GB" here. This
1394506f1d07SSam Ravnborg	  selection turns Intel PAE (Physical Address Extension) mode on.
1395506f1d07SSam Ravnborg	  PAE implements 3-level paging on IA32 processors. PAE is fully
1396506f1d07SSam Ravnborg	  supported by Linux, PAE mode is implemented on all recent Intel
1397506f1d07SSam Ravnborg	  processors (Pentium Pro and better). NOTE: If you say "64GB" here,
1398506f1d07SSam Ravnborg	  then the kernel will not boot on CPUs that don't support PAE!
1399506f1d07SSam Ravnborg
1400506f1d07SSam Ravnborg	  The actual amount of total physical memory will either be
1401506f1d07SSam Ravnborg	  auto detected or can be forced by using a kernel command line option
1402506f1d07SSam Ravnborg	  such as "mem=256M". (Try "man bootparam" or see the documentation of
1403506f1d07SSam Ravnborg	  your boot loader (lilo or loadlin) about how to pass options to the
1404506f1d07SSam Ravnborg	  kernel at boot time.)
1405506f1d07SSam Ravnborg
1406506f1d07SSam Ravnborg	  If unsure, say "off".
1407506f1d07SSam Ravnborg
1408506f1d07SSam Ravnborgconfig HIGHMEM4G
1409506f1d07SSam Ravnborg	bool "4GB"
14108f9ca475SIngo Molnar	---help---
1411506f1d07SSam Ravnborg	  Select this if you have a 32-bit processor and between 1 and 4
1412506f1d07SSam Ravnborg	  gigabytes of physical RAM.
1413506f1d07SSam Ravnborg
1414506f1d07SSam Ravnborgconfig HIGHMEM64G
1415506f1d07SSam Ravnborg	bool "64GB"
141669b8d3fcSMatthew Whitehead	depends on !M486 && !M586 && !M586TSC && !M586MMX && !MGEODE_LX && !MGEODEGX1 && !MCYRIXIII && !MELAN && !MWINCHIPC6 && !WINCHIP3D && !MK6
1417506f1d07SSam Ravnborg	select X86_PAE
14188f9ca475SIngo Molnar	---help---
1419506f1d07SSam Ravnborg	  Select this if you have a 32-bit processor and more than 4
1420506f1d07SSam Ravnborg	  gigabytes of physical RAM.
1421506f1d07SSam Ravnborg
1422506f1d07SSam Ravnborgendchoice
1423506f1d07SSam Ravnborg
1424506f1d07SSam Ravnborgchoice
14256a108a14SDavid Rientjes	prompt "Memory split" if EXPERT
1426506f1d07SSam Ravnborg	default VMSPLIT_3G
1427506f1d07SSam Ravnborg	depends on X86_32
14288f9ca475SIngo Molnar	---help---
1429506f1d07SSam Ravnborg	  Select the desired split between kernel and user memory.
1430506f1d07SSam Ravnborg
1431506f1d07SSam Ravnborg	  If the address range available to the kernel is less than the
1432506f1d07SSam Ravnborg	  physical memory installed, the remaining memory will be available
1433506f1d07SSam Ravnborg	  as "high memory". Accessing high memory is a little more costly
1434506f1d07SSam Ravnborg	  than low memory, as it needs to be mapped into the kernel first.
1435506f1d07SSam Ravnborg	  Note that increasing the kernel address space limits the range
1436506f1d07SSam Ravnborg	  available to user programs, making the address space there
1437506f1d07SSam Ravnborg	  tighter.  Selecting anything other than the default 3G/1G split
1438506f1d07SSam Ravnborg	  will also likely make your kernel incompatible with binary-only
1439506f1d07SSam Ravnborg	  kernel modules.
1440506f1d07SSam Ravnborg
1441506f1d07SSam Ravnborg	  If you are not absolutely sure what you are doing, leave this
1442506f1d07SSam Ravnborg	  option alone!
1443506f1d07SSam Ravnborg
1444506f1d07SSam Ravnborg	config VMSPLIT_3G
1445506f1d07SSam Ravnborg		bool "3G/1G user/kernel split"
1446506f1d07SSam Ravnborg	config VMSPLIT_3G_OPT
1447506f1d07SSam Ravnborg		depends on !X86_PAE
1448506f1d07SSam Ravnborg		bool "3G/1G user/kernel split (for full 1G low memory)"
1449506f1d07SSam Ravnborg	config VMSPLIT_2G
1450506f1d07SSam Ravnborg		bool "2G/2G user/kernel split"
1451506f1d07SSam Ravnborg	config VMSPLIT_2G_OPT
1452506f1d07SSam Ravnborg		depends on !X86_PAE
1453506f1d07SSam Ravnborg		bool "2G/2G user/kernel split (for full 2G low memory)"
1454506f1d07SSam Ravnborg	config VMSPLIT_1G
1455506f1d07SSam Ravnborg		bool "1G/3G user/kernel split"
1456506f1d07SSam Ravnborgendchoice
1457506f1d07SSam Ravnborg
1458506f1d07SSam Ravnborgconfig PAGE_OFFSET
1459506f1d07SSam Ravnborg	hex
1460506f1d07SSam Ravnborg	default 0xB0000000 if VMSPLIT_3G_OPT
1461506f1d07SSam Ravnborg	default 0x80000000 if VMSPLIT_2G
1462506f1d07SSam Ravnborg	default 0x78000000 if VMSPLIT_2G_OPT
1463506f1d07SSam Ravnborg	default 0x40000000 if VMSPLIT_1G
1464506f1d07SSam Ravnborg	default 0xC0000000
1465506f1d07SSam Ravnborg	depends on X86_32
1466506f1d07SSam Ravnborg
1467506f1d07SSam Ravnborgconfig HIGHMEM
14683c2362e6SHarvey Harrison	def_bool y
1469506f1d07SSam Ravnborg	depends on X86_32 && (HIGHMEM64G || HIGHMEM4G)
1470506f1d07SSam Ravnborg
1471506f1d07SSam Ravnborgconfig X86_PAE
14729ba16087SJan Beulich	bool "PAE (Physical Address Extension) Support"
1473506f1d07SSam Ravnborg	depends on X86_32 && !HIGHMEM4G
1474d4a451d5SChristoph Hellwig	select PHYS_ADDR_T_64BIT
14759d99c712SChristian Melki	select SWIOTLB
14768f9ca475SIngo Molnar	---help---
1477506f1d07SSam Ravnborg	  PAE is required for NX support, and furthermore enables
1478506f1d07SSam Ravnborg	  larger swapspace support for non-overcommit purposes. It
1479506f1d07SSam Ravnborg	  has the cost of more pagetable lookup overhead, and also
1480506f1d07SSam Ravnborg	  consumes more pagetable space per process.
1481506f1d07SSam Ravnborg
148277ef56e4SKirill A. Shutemovconfig X86_5LEVEL
148377ef56e4SKirill A. Shutemov	bool "Enable 5-level page tables support"
148418ec1eafSKirill A. Shutemov	default y
1485eedb92abSKirill A. Shutemov	select DYNAMIC_MEMORY_LAYOUT
1486162434e7SKirill A. Shutemov	select SPARSEMEM_VMEMMAP
148777ef56e4SKirill A. Shutemov	depends on X86_64
148877ef56e4SKirill A. Shutemov	---help---
148977ef56e4SKirill A. Shutemov	  5-level paging enables access to larger address space:
149077ef56e4SKirill A. Shutemov	  upto 128 PiB of virtual address space and 4 PiB of
149177ef56e4SKirill A. Shutemov	  physical address space.
149277ef56e4SKirill A. Shutemov
149377ef56e4SKirill A. Shutemov	  It will be supported by future Intel CPUs.
149477ef56e4SKirill A. Shutemov
14956657fca0SKirill A. Shutemov	  A kernel with the option enabled can be booted on machines that
14966657fca0SKirill A. Shutemov	  support 4- or 5-level paging.
149777ef56e4SKirill A. Shutemov
1498cb1aaebeSMauro Carvalho Chehab	  See Documentation/x86/x86_64/5level-paging.rst for more
149977ef56e4SKirill A. Shutemov	  information.
150077ef56e4SKirill A. Shutemov
150177ef56e4SKirill A. Shutemov	  Say N if unsure.
150277ef56e4SKirill A. Shutemov
150310971ab2SIngo Molnarconfig X86_DIRECT_GBPAGES
1504e5008abeSLuis R. Rodriguez	def_bool y
15052e1da13fSVlastimil Babka	depends on X86_64
15068f9ca475SIngo Molnar	---help---
150710971ab2SIngo Molnar	  Certain kernel features effectively disable kernel
150810971ab2SIngo Molnar	  linear 1 GB mappings (even if the CPU otherwise
150910971ab2SIngo Molnar	  supports them), so don't confuse the user by printing
151010971ab2SIngo Molnar	  that we have them enabled.
15119e899816SNick Piggin
15125c280cf6SThomas Gleixnerconfig X86_CPA_STATISTICS
15135c280cf6SThomas Gleixner	bool "Enable statistic for Change Page Attribute"
15145c280cf6SThomas Gleixner	depends on DEBUG_FS
15155c280cf6SThomas Gleixner	---help---
1516b75baaf3SIngo Molnar	  Expose statistics about the Change Page Attribute mechanism, which
1517a943245aSColin Ian King	  helps to determine the effectiveness of preserving large and huge
15185c280cf6SThomas Gleixner	  page mappings when mapping protections are changed.
15195c280cf6SThomas Gleixner
15207744ccdbSTom Lendackyconfig AMD_MEM_ENCRYPT
15217744ccdbSTom Lendacky	bool "AMD Secure Memory Encryption (SME) support"
15227744ccdbSTom Lendacky	depends on X86_64 && CPU_SUP_AMD
152394d49eb3SKirill A. Shutemov	select DYNAMIC_PHYSICAL_MASK
1524ce9084baSArd Biesheuvel	select ARCH_USE_MEMREMAP_PROT
15259087c375STom Lendacky	select ARCH_HAS_FORCE_DMA_UNENCRYPTED
15267744ccdbSTom Lendacky	---help---
15277744ccdbSTom Lendacky	  Say yes to enable support for the encryption of system memory.
15287744ccdbSTom Lendacky	  This requires an AMD processor that supports Secure Memory
15297744ccdbSTom Lendacky	  Encryption (SME).
15307744ccdbSTom Lendacky
15317744ccdbSTom Lendackyconfig AMD_MEM_ENCRYPT_ACTIVE_BY_DEFAULT
15327744ccdbSTom Lendacky	bool "Activate AMD Secure Memory Encryption (SME) by default"
15337744ccdbSTom Lendacky	default y
15347744ccdbSTom Lendacky	depends on AMD_MEM_ENCRYPT
15357744ccdbSTom Lendacky	---help---
15367744ccdbSTom Lendacky	  Say yes to have system memory encrypted by default if running on
15377744ccdbSTom Lendacky	  an AMD processor that supports Secure Memory Encryption (SME).
15387744ccdbSTom Lendacky
15397744ccdbSTom Lendacky	  If set to Y, then the encryption of system memory can be
15407744ccdbSTom Lendacky	  deactivated with the mem_encrypt=off command line option.
15417744ccdbSTom Lendacky
15427744ccdbSTom Lendacky	  If set to N, then the encryption of system memory can be
15437744ccdbSTom Lendacky	  activated with the mem_encrypt=on command line option.
15447744ccdbSTom Lendacky
1545506f1d07SSam Ravnborg# Common NUMA Features
1546506f1d07SSam Ravnborgconfig NUMA
1547e133f6eaSRandy Dunlap	bool "NUMA Memory Allocation and Scheduler Support"
1548506f1d07SSam Ravnborg	depends on SMP
1549b5660ba7SH. Peter Anvin	depends on X86_64 || (X86_32 && HIGHMEM64G && X86_BIGSMP)
1550b5660ba7SH. Peter Anvin	default y if X86_BIGSMP
15518f9ca475SIngo Molnar	---help---
1552e133f6eaSRandy Dunlap	  Enable NUMA (Non-Uniform Memory Access) support.
1553fd51b2d7SKOSAKI Motohiro
1554506f1d07SSam Ravnborg	  The kernel will try to allocate memory used by a CPU on the
1555506f1d07SSam Ravnborg	  local memory controller of the CPU and add some more
1556506f1d07SSam Ravnborg	  NUMA awareness to the kernel.
1557506f1d07SSam Ravnborg
1558c280ea5eSIngo Molnar	  For 64-bit this is recommended if the system is Intel Core i7
1559fd51b2d7SKOSAKI Motohiro	  (or later), AMD Opteron, or EM64T NUMA.
1560fd51b2d7SKOSAKI Motohiro
1561b5660ba7SH. Peter Anvin	  For 32-bit this is only needed if you boot a 32-bit
15627cf6c945SDavid Rientjes	  kernel on a 64-bit NUMA platform.
1563fd51b2d7SKOSAKI Motohiro
1564fd51b2d7SKOSAKI Motohiro	  Otherwise, you should say N.
1565506f1d07SSam Ravnborg
1566eec1d4faSHans Rosenfeldconfig AMD_NUMA
15673c2362e6SHarvey Harrison	def_bool y
15683c2362e6SHarvey Harrison	prompt "Old style AMD Opteron NUMA detection"
15695da0ef9aSTejun Heo	depends on X86_64 && NUMA && PCI
15708f9ca475SIngo Molnar	---help---
1571eec1d4faSHans Rosenfeld	  Enable AMD NUMA node topology detection.  You should say Y here if
1572eec1d4faSHans Rosenfeld	  you have a multi processor AMD system. This uses an old method to
1573eec1d4faSHans Rosenfeld	  read the NUMA configuration directly from the builtin Northbridge
1574eec1d4faSHans Rosenfeld	  of Opteron. It is recommended to use X86_64_ACPI_NUMA instead,
1575eec1d4faSHans Rosenfeld	  which also takes priority if both are compiled in.
1576506f1d07SSam Ravnborg
1577506f1d07SSam Ravnborgconfig X86_64_ACPI_NUMA
15783c2362e6SHarvey Harrison	def_bool y
15793c2362e6SHarvey Harrison	prompt "ACPI NUMA detection"
1580506f1d07SSam Ravnborg	depends on X86_64 && NUMA && ACPI && PCI
1581506f1d07SSam Ravnborg	select ACPI_NUMA
15828f9ca475SIngo Molnar	---help---
1583506f1d07SSam Ravnborg	  Enable ACPI SRAT based node topology detection.
1584506f1d07SSam Ravnborg
15856ec6e0d9SSuresh Siddha# Some NUMA nodes have memory ranges that span
15866ec6e0d9SSuresh Siddha# other nodes.  Even though a pfn is valid and
15876ec6e0d9SSuresh Siddha# between a node's start and end pfns, it may not
15886ec6e0d9SSuresh Siddha# reside on that node.  See memmap_init_zone()
15896ec6e0d9SSuresh Siddha# for details.
15906ec6e0d9SSuresh Siddhaconfig NODES_SPAN_OTHER_NODES
15916ec6e0d9SSuresh Siddha	def_bool y
15926ec6e0d9SSuresh Siddha	depends on X86_64_ACPI_NUMA
15936ec6e0d9SSuresh Siddha
1594506f1d07SSam Ravnborgconfig NUMA_EMU
1595506f1d07SSam Ravnborg	bool "NUMA emulation"
15961b7e03efSTejun Heo	depends on NUMA
15978f9ca475SIngo Molnar	---help---
1598506f1d07SSam Ravnborg	  Enable NUMA emulation. A flat machine will be split
1599506f1d07SSam Ravnborg	  into virtual nodes when booted with "numa=fake=N", where N is the
1600506f1d07SSam Ravnborg	  number of nodes. This is only useful for debugging.
1601506f1d07SSam Ravnborg
1602506f1d07SSam Ravnborgconfig NODES_SHIFT
1603d25e26b6SLinus Torvalds	int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP
160451591e31SDavid Rientjes	range 1 10
160551591e31SDavid Rientjes	default "10" if MAXSMP
1606506f1d07SSam Ravnborg	default "6" if X86_64
1607506f1d07SSam Ravnborg	default "3"
1608506f1d07SSam Ravnborg	depends on NEED_MULTIPLE_NODES
16098f9ca475SIngo Molnar	---help---
16101184dc2fSMike Travis	  Specify the maximum number of NUMA Nodes available on the target
1611692105b8SMatt LaPlante	  system.  Increases memory reserved to accommodate various tables.
1612506f1d07SSam Ravnborg
1613506f1d07SSam Ravnborgconfig ARCH_HAVE_MEMORY_PRESENT
16143c2362e6SHarvey Harrison	def_bool y
1615506f1d07SSam Ravnborg	depends on X86_32 && DISCONTIGMEM
1616506f1d07SSam Ravnborg
1617506f1d07SSam Ravnborgconfig ARCH_FLATMEM_ENABLE
1618506f1d07SSam Ravnborg	def_bool y
16193b16651fSTejun Heo	depends on X86_32 && !NUMA
1620506f1d07SSam Ravnborg
1621506f1d07SSam Ravnborgconfig ARCH_DISCONTIGMEM_ENABLE
16222792107dSMike Rapoport	def_bool n
1623b263295dSChristoph Lameter	depends on NUMA && X86_32
16242792107dSMike Rapoport	depends on BROKEN
1625b263295dSChristoph Lameter
1626506f1d07SSam Ravnborgconfig ARCH_SPARSEMEM_ENABLE
1627506f1d07SSam Ravnborg	def_bool y
16286ea30386SKees Cook	depends on X86_64 || NUMA || X86_32 || X86_32_NON_STANDARD
1629506f1d07SSam Ravnborg	select SPARSEMEM_STATIC if X86_32
1630506f1d07SSam Ravnborg	select SPARSEMEM_VMEMMAP_ENABLE if X86_64
1631506f1d07SSam Ravnborg
16323b16651fSTejun Heoconfig ARCH_SPARSEMEM_DEFAULT
16336ad57f7fSMike Rapoport	def_bool X86_64 || (NUMA && X86_32)
16343b16651fSTejun Heo
1635506f1d07SSam Ravnborgconfig ARCH_SELECT_MEMORY_MODEL
1636506f1d07SSam Ravnborg	def_bool y
1637b263295dSChristoph Lameter	depends on ARCH_SPARSEMEM_ENABLE
1638506f1d07SSam Ravnborg
1639506f1d07SSam Ravnborgconfig ARCH_MEMORY_PROBE
1640a0842b70SToshi Kani	bool "Enable sysfs memory/probe interface"
16413120e25eSJan Beulich	depends on X86_64 && MEMORY_HOTPLUG
1642a0842b70SToshi Kani	help
1643a0842b70SToshi Kani	  This option enables a sysfs memory/probe interface for testing.
1644cb1aaebeSMauro Carvalho Chehab	  See Documentation/admin-guide/mm/memory-hotplug.rst for more information.
1645a0842b70SToshi Kani	  If you are unsure how to answer this question, answer N.
1646506f1d07SSam Ravnborg
16473b16651fSTejun Heoconfig ARCH_PROC_KCORE_TEXT
16483b16651fSTejun Heo	def_bool y
16493b16651fSTejun Heo	depends on X86_64 && PROC_KCORE
16503b16651fSTejun Heo
1651a29815a3SAvi Kivityconfig ILLEGAL_POINTER_VALUE
1652a29815a3SAvi Kivity	hex
1653a29815a3SAvi Kivity	default 0 if X86_32
1654a29815a3SAvi Kivity	default 0xdead000000000000 if X86_64
1655a29815a3SAvi Kivity
16567a67832cSDan Williamsconfig X86_PMEM_LEGACY_DEVICE
16577a67832cSDan Williams	bool
16587a67832cSDan Williams
1659ec776ef6SChristoph Hellwigconfig X86_PMEM_LEGACY
16607a67832cSDan Williams	tristate "Support non-standard NVDIMMs and ADR protected memory"
16619f53f9faSDan Williams	depends on PHYS_ADDR_T_64BIT
16629f53f9faSDan Williams	depends on BLK_DEV
16637a67832cSDan Williams	select X86_PMEM_LEGACY_DEVICE
16647b27a862SDan Williams	select NUMA_KEEP_MEMINFO if NUMA
16659f53f9faSDan Williams	select LIBNVDIMM
1666ec776ef6SChristoph Hellwig	help
1667ec776ef6SChristoph Hellwig	  Treat memory marked using the non-standard e820 type of 12 as used
1668ec776ef6SChristoph Hellwig	  by the Intel Sandy Bridge-EP reference BIOS as protected memory.
1669ec776ef6SChristoph Hellwig	  The kernel will offer these regions to the 'pmem' driver so
1670ec776ef6SChristoph Hellwig	  they can be used for persistent storage.
1671ec776ef6SChristoph Hellwig
1672ec776ef6SChristoph Hellwig	  Say Y if unsure.
1673ec776ef6SChristoph Hellwig
1674506f1d07SSam Ravnborgconfig HIGHPTE
1675506f1d07SSam Ravnborg	bool "Allocate 3rd-level pagetables from highmem"
16766fc108a0SJan Beulich	depends on HIGHMEM
16778f9ca475SIngo Molnar	---help---
1678506f1d07SSam Ravnborg	  The VM uses one page table entry for each page of physical memory.
1679506f1d07SSam Ravnborg	  For systems with a lot of RAM, this can be wasteful of precious
1680506f1d07SSam Ravnborg	  low memory.  Setting this option will put user-space page table
1681506f1d07SSam Ravnborg	  entries in high memory.
1682506f1d07SSam Ravnborg
16839f077871SJeremy Fitzhardingeconfig X86_CHECK_BIOS_CORRUPTION
16849f077871SJeremy Fitzhardinge	bool "Check for low memory corruption"
16858f9ca475SIngo Molnar	---help---
16869f077871SJeremy Fitzhardinge	  Periodically check for memory corruption in low memory, which
16879f077871SJeremy Fitzhardinge	  is suspected to be caused by BIOS.  Even when enabled in the
16889f077871SJeremy Fitzhardinge	  configuration, it is disabled at runtime.  Enable it by
16899f077871SJeremy Fitzhardinge	  setting "memory_corruption_check=1" on the kernel command
16909f077871SJeremy Fitzhardinge	  line.  By default it scans the low 64k of memory every 60
16919f077871SJeremy Fitzhardinge	  seconds; see the memory_corruption_check_size and
16929f077871SJeremy Fitzhardinge	  memory_corruption_check_period parameters in
16938c27ceffSMauro Carvalho Chehab	  Documentation/admin-guide/kernel-parameters.rst to adjust this.
16949f077871SJeremy Fitzhardinge
16959f077871SJeremy Fitzhardinge	  When enabled with the default parameters, this option has
16969f077871SJeremy Fitzhardinge	  almost no overhead, as it reserves a relatively small amount
16979f077871SJeremy Fitzhardinge	  of memory and scans it infrequently.  It both detects corruption
16989f077871SJeremy Fitzhardinge	  and prevents it from affecting the running system.
16999f077871SJeremy Fitzhardinge
17009f077871SJeremy Fitzhardinge	  It is, however, intended as a diagnostic tool; if repeatable
17019f077871SJeremy Fitzhardinge	  BIOS-originated corruption always affects the same memory,
17029f077871SJeremy Fitzhardinge	  you can use memmap= to prevent the kernel from using that
17039f077871SJeremy Fitzhardinge	  memory.
17049f077871SJeremy Fitzhardinge
1705c885df50SJeremy Fitzhardingeconfig X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK
1706c885df50SJeremy Fitzhardinge	bool "Set the default setting of memory_corruption_check"
1707c885df50SJeremy Fitzhardinge	depends on X86_CHECK_BIOS_CORRUPTION
1708c885df50SJeremy Fitzhardinge	default y
17098f9ca475SIngo Molnar	---help---
1710c885df50SJeremy Fitzhardinge	  Set whether the default state of memory_corruption_check is
1711c885df50SJeremy Fitzhardinge	  on or off.
1712c885df50SJeremy Fitzhardinge
17139ea77bdbSH. Peter Anvinconfig X86_RESERVE_LOW
1714d0cd7425SH. Peter Anvin	int "Amount of low memory, in kilobytes, to reserve for the BIOS"
1715d0cd7425SH. Peter Anvin	default 64
1716d0cd7425SH. Peter Anvin	range 4 640
17178f9ca475SIngo Molnar	---help---
1718d0cd7425SH. Peter Anvin	  Specify the amount of low memory to reserve for the BIOS.
1719fc381519SIngo Molnar
1720d0cd7425SH. Peter Anvin	  The first page contains BIOS data structures that the kernel
1721d0cd7425SH. Peter Anvin	  must not use, so that page must always be reserved.
1722fc381519SIngo Molnar
1723d0cd7425SH. Peter Anvin	  By default we reserve the first 64K of physical RAM, as a
1724d0cd7425SH. Peter Anvin	  number of BIOSes are known to corrupt that memory range
1725d0cd7425SH. Peter Anvin	  during events such as suspend/resume or monitor cable
1726d0cd7425SH. Peter Anvin	  insertion, so it must not be used by the kernel.
1727fc381519SIngo Molnar
1728d0cd7425SH. Peter Anvin	  You can set this to 4 if you are absolutely sure that you
1729d0cd7425SH. Peter Anvin	  trust the BIOS to get all its memory reservations and usages
1730d0cd7425SH. Peter Anvin	  right.  If you know your BIOS have problems beyond the
1731d0cd7425SH. Peter Anvin	  default 64K area, you can set this to 640 to avoid using the
1732d0cd7425SH. Peter Anvin	  entire low memory range.
1733d0cd7425SH. Peter Anvin
1734d0cd7425SH. Peter Anvin	  If you have doubts about the BIOS (e.g. suspend/resume does
1735d0cd7425SH. Peter Anvin	  not work or there's kernel crashes after certain hardware
1736d0cd7425SH. Peter Anvin	  hotplug events) then you might want to enable
1737d0cd7425SH. Peter Anvin	  X86_CHECK_BIOS_CORRUPTION=y to allow the kernel to check
1738d0cd7425SH. Peter Anvin	  typical corruption patterns.
1739d0cd7425SH. Peter Anvin
1740d0cd7425SH. Peter Anvin	  Leave this to the default value of 64 if you are unsure.
1741fc381519SIngo Molnar
1742506f1d07SSam Ravnborgconfig MATH_EMULATION
1743506f1d07SSam Ravnborg	bool
1744a5b9e5a2SAndy Lutomirski	depends on MODIFY_LDT_SYSCALL
174587d6021bSArnd Bergmann	prompt "Math emulation" if X86_32 && (M486SX || MELAN)
1746506f1d07SSam Ravnborg	---help---
1747506f1d07SSam Ravnborg	  Linux can emulate a math coprocessor (used for floating point
1748506f1d07SSam Ravnborg	  operations) if you don't have one. 486DX and Pentium processors have
1749506f1d07SSam Ravnborg	  a math coprocessor built in, 486SX and 386 do not, unless you added
1750506f1d07SSam Ravnborg	  a 487DX or 387, respectively. (The messages during boot time can
1751506f1d07SSam Ravnborg	  give you some hints here ["man dmesg"].) Everyone needs either a
1752506f1d07SSam Ravnborg	  coprocessor or this emulation.
1753506f1d07SSam Ravnborg
1754506f1d07SSam Ravnborg	  If you don't have a math coprocessor, you need to say Y here; if you
1755506f1d07SSam Ravnborg	  say Y here even though you have a coprocessor, the coprocessor will
1756506f1d07SSam Ravnborg	  be used nevertheless. (This behavior can be changed with the kernel
1757506f1d07SSam Ravnborg	  command line option "no387", which comes handy if your coprocessor
1758506f1d07SSam Ravnborg	  is broken. Try "man bootparam" or see the documentation of your boot
1759506f1d07SSam Ravnborg	  loader (lilo or loadlin) about how to pass options to the kernel at
1760506f1d07SSam Ravnborg	  boot time.) This means that it is a good idea to say Y here if you
1761506f1d07SSam Ravnborg	  intend to use this kernel on different machines.
1762506f1d07SSam Ravnborg
1763506f1d07SSam Ravnborg	  More information about the internals of the Linux math coprocessor
1764506f1d07SSam Ravnborg	  emulation can be found in <file:arch/x86/math-emu/README>.
1765506f1d07SSam Ravnborg
1766506f1d07SSam Ravnborg	  If you are not sure, say Y; apart from resulting in a 66 KB bigger
1767506f1d07SSam Ravnborg	  kernel, it won't hurt.
1768506f1d07SSam Ravnborg
1769506f1d07SSam Ravnborgconfig MTRR
17706fc108a0SJan Beulich	def_bool y
17716a108a14SDavid Rientjes	prompt "MTRR (Memory Type Range Register) support" if EXPERT
1772506f1d07SSam Ravnborg	---help---
1773506f1d07SSam Ravnborg	  On Intel P6 family processors (Pentium Pro, Pentium II and later)
1774506f1d07SSam Ravnborg	  the Memory Type Range Registers (MTRRs) may be used to control
1775506f1d07SSam Ravnborg	  processor access to memory ranges. This is most useful if you have
1776506f1d07SSam Ravnborg	  a video (VGA) card on a PCI or AGP bus. Enabling write-combining
1777506f1d07SSam Ravnborg	  allows bus write transfers to be combined into a larger transfer
1778506f1d07SSam Ravnborg	  before bursting over the PCI/AGP bus. This can increase performance
1779506f1d07SSam Ravnborg	  of image write operations 2.5 times or more. Saying Y here creates a
1780506f1d07SSam Ravnborg	  /proc/mtrr file which may be used to manipulate your processor's
1781506f1d07SSam Ravnborg	  MTRRs. Typically the X server should use this.
1782506f1d07SSam Ravnborg
1783506f1d07SSam Ravnborg	  This code has a reasonably generic interface so that similar
1784506f1d07SSam Ravnborg	  control registers on other processors can be easily supported
1785506f1d07SSam Ravnborg	  as well:
1786506f1d07SSam Ravnborg
1787506f1d07SSam Ravnborg	  The Cyrix 6x86, 6x86MX and M II processors have Address Range
1788506f1d07SSam Ravnborg	  Registers (ARRs) which provide a similar functionality to MTRRs. For
1789506f1d07SSam Ravnborg	  these, the ARRs are used to emulate the MTRRs.
1790506f1d07SSam Ravnborg	  The AMD K6-2 (stepping 8 and above) and K6-3 processors have two
1791506f1d07SSam Ravnborg	  MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing
1792506f1d07SSam Ravnborg	  write-combining. All of these processors are supported by this code
1793506f1d07SSam Ravnborg	  and it makes sense to say Y here if you have one of them.
1794506f1d07SSam Ravnborg
1795506f1d07SSam Ravnborg	  Saying Y here also fixes a problem with buggy SMP BIOSes which only
1796506f1d07SSam Ravnborg	  set the MTRRs for the boot CPU and not for the secondary CPUs. This
1797506f1d07SSam Ravnborg	  can lead to all sorts of problems, so it's good to say Y here.
1798506f1d07SSam Ravnborg
1799506f1d07SSam Ravnborg	  You can safely say Y even if your machine doesn't have MTRRs, you'll
1800506f1d07SSam Ravnborg	  just add about 9 KB to your kernel.
1801506f1d07SSam Ravnborg
1802cb1aaebeSMauro Carvalho Chehab	  See <file:Documentation/x86/mtrr.rst> for more information.
1803506f1d07SSam Ravnborg
180495ffa243SYinghai Luconfig MTRR_SANITIZER
18052ffb3501SYinghai Lu	def_bool y
180695ffa243SYinghai Lu	prompt "MTRR cleanup support"
180795ffa243SYinghai Lu	depends on MTRR
18088f9ca475SIngo Molnar	---help---
1809aba3728cSThomas Gleixner	  Convert MTRR layout from continuous to discrete, so X drivers can
1810aba3728cSThomas Gleixner	  add writeback entries.
181195ffa243SYinghai Lu
1812aba3728cSThomas Gleixner	  Can be disabled with disable_mtrr_cleanup on the kernel command line.
1813692105b8SMatt LaPlante	  The largest mtrr entry size for a continuous block can be set with
1814aba3728cSThomas Gleixner	  mtrr_chunk_size.
181595ffa243SYinghai Lu
18162ffb3501SYinghai Lu	  If unsure, say Y.
181795ffa243SYinghai Lu
181895ffa243SYinghai Luconfig MTRR_SANITIZER_ENABLE_DEFAULT
1819f5098d62SYinghai Lu	int "MTRR cleanup enable value (0-1)"
1820f5098d62SYinghai Lu	range 0 1
1821f5098d62SYinghai Lu	default "0"
182295ffa243SYinghai Lu	depends on MTRR_SANITIZER
18238f9ca475SIngo Molnar	---help---
1824f5098d62SYinghai Lu	  Enable mtrr cleanup default value
182595ffa243SYinghai Lu
182612031a62SYinghai Luconfig MTRR_SANITIZER_SPARE_REG_NR_DEFAULT
182712031a62SYinghai Lu	int "MTRR cleanup spare reg num (0-7)"
182812031a62SYinghai Lu	range 0 7
182912031a62SYinghai Lu	default "1"
183012031a62SYinghai Lu	depends on MTRR_SANITIZER
18318f9ca475SIngo Molnar	---help---
183212031a62SYinghai Lu	  mtrr cleanup spare entries default, it can be changed via
1833aba3728cSThomas Gleixner	  mtrr_spare_reg_nr=N on the kernel command line.
183412031a62SYinghai Lu
18352e5d9c85Svenkatesh.pallipadi@intel.comconfig X86_PAT
18366fc108a0SJan Beulich	def_bool y
18376a108a14SDavid Rientjes	prompt "x86 PAT support" if EXPERT
18382a8a2719SIngo Molnar	depends on MTRR
18398f9ca475SIngo Molnar	---help---
18402e5d9c85Svenkatesh.pallipadi@intel.com	  Use PAT attributes to setup page level cache control.
1841042b78e4SVenki Pallipadi
18422e5d9c85Svenkatesh.pallipadi@intel.com	  PATs are the modern equivalents of MTRRs and are much more
18432e5d9c85Svenkatesh.pallipadi@intel.com	  flexible than MTRRs.
18442e5d9c85Svenkatesh.pallipadi@intel.com
18452e5d9c85Svenkatesh.pallipadi@intel.com	  Say N here if you see bootup problems (boot crash, boot hang,
1846042b78e4SVenki Pallipadi	  spontaneous reboots) or a non-working video driver.
18472e5d9c85Svenkatesh.pallipadi@intel.com
18482e5d9c85Svenkatesh.pallipadi@intel.com	  If unsure, say Y.
18492e5d9c85Svenkatesh.pallipadi@intel.com
185046cf98cdSVenkatesh Pallipadiconfig ARCH_USES_PG_UNCACHED
185146cf98cdSVenkatesh Pallipadi	def_bool y
185246cf98cdSVenkatesh Pallipadi	depends on X86_PAT
185346cf98cdSVenkatesh Pallipadi
1854628c6246SH. Peter Anvinconfig ARCH_RANDOM
1855628c6246SH. Peter Anvin	def_bool y
1856628c6246SH. Peter Anvin	prompt "x86 architectural random number generator" if EXPERT
1857628c6246SH. Peter Anvin	---help---
1858628c6246SH. Peter Anvin	  Enable the x86 architectural RDRAND instruction
1859628c6246SH. Peter Anvin	  (Intel Bull Mountain technology) to generate random numbers.
1860628c6246SH. Peter Anvin	  If supported, this is a high bandwidth, cryptographically
1861628c6246SH. Peter Anvin	  secure hardware random number generator.
1862628c6246SH. Peter Anvin
186351ae4a2dSH. Peter Anvinconfig X86_SMAP
186451ae4a2dSH. Peter Anvin	def_bool y
186551ae4a2dSH. Peter Anvin	prompt "Supervisor Mode Access Prevention" if EXPERT
186651ae4a2dSH. Peter Anvin	---help---
186751ae4a2dSH. Peter Anvin	  Supervisor Mode Access Prevention (SMAP) is a security
186851ae4a2dSH. Peter Anvin	  feature in newer Intel processors.  There is a small
186951ae4a2dSH. Peter Anvin	  performance cost if this enabled and turned on; there is
187051ae4a2dSH. Peter Anvin	  also a small increase in the kernel size if this is enabled.
187151ae4a2dSH. Peter Anvin
187251ae4a2dSH. Peter Anvin	  If unsure, say Y.
187351ae4a2dSH. Peter Anvin
1874b971880fSBabu Mogerconfig X86_UMIP
1875796ebc81SRicardo Neri	def_bool y
1876b971880fSBabu Moger	prompt "User Mode Instruction Prevention" if EXPERT
1877aa35f896SRicardo Neri	---help---
1878b971880fSBabu Moger	  User Mode Instruction Prevention (UMIP) is a security feature in
1879b971880fSBabu Moger	  some x86 processors. If enabled, a general protection fault is
1880b971880fSBabu Moger	  issued if the SGDT, SLDT, SIDT, SMSW or STR instructions are
1881b971880fSBabu Moger	  executed in user mode. These instructions unnecessarily expose
1882b971880fSBabu Moger	  information about the hardware state.
1883796ebc81SRicardo Neri
1884796ebc81SRicardo Neri	  The vast majority of applications do not use these instructions.
1885796ebc81SRicardo Neri	  For the very few that do, software emulation is provided in
1886796ebc81SRicardo Neri	  specific cases in protected and virtual-8086 modes. Emulated
1887796ebc81SRicardo Neri	  results are dummy.
1888aa35f896SRicardo Neri
188935e97790SDave Hansenconfig X86_INTEL_MEMORY_PROTECTION_KEYS
1890*38f3e775SBabu Moger	prompt "Memory Protection Keys"
189135e97790SDave Hansen	def_bool y
1892284244a9SDave Hansen	# Note: only available in 64-bit mode
1893*38f3e775SBabu Moger	depends on X86_64 && (CPU_SUP_INTEL || CPU_SUP_AMD)
189452c8e601SIngo Molnar	select ARCH_USES_HIGH_VMA_FLAGS
189552c8e601SIngo Molnar	select ARCH_HAS_PKEYS
1896284244a9SDave Hansen	---help---
1897284244a9SDave Hansen	  Memory Protection Keys provides a mechanism for enforcing
1898284244a9SDave Hansen	  page-based protections, but without requiring modification of the
1899284244a9SDave Hansen	  page tables when an application changes protection domains.
1900284244a9SDave Hansen
19011eecbcdcSMauro Carvalho Chehab	  For details, see Documentation/core-api/protection-keys.rst
1902284244a9SDave Hansen
1903284244a9SDave Hansen	  If unsure, say y.
190435e97790SDave Hansen
1905db616173SMichal Hockochoice
1906db616173SMichal Hocko	prompt "TSX enable mode"
1907db616173SMichal Hocko	depends on CPU_SUP_INTEL
1908db616173SMichal Hocko	default X86_INTEL_TSX_MODE_OFF
1909db616173SMichal Hocko	help
1910db616173SMichal Hocko	  Intel's TSX (Transactional Synchronization Extensions) feature
1911db616173SMichal Hocko	  allows to optimize locking protocols through lock elision which
1912db616173SMichal Hocko	  can lead to a noticeable performance boost.
1913db616173SMichal Hocko
1914db616173SMichal Hocko	  On the other hand it has been shown that TSX can be exploited
1915db616173SMichal Hocko	  to form side channel attacks (e.g. TAA) and chances are there
1916db616173SMichal Hocko	  will be more of those attacks discovered in the future.
1917db616173SMichal Hocko
1918db616173SMichal Hocko	  Therefore TSX is not enabled by default (aka tsx=off). An admin
1919db616173SMichal Hocko	  might override this decision by tsx=on the command line parameter.
1920db616173SMichal Hocko	  Even with TSX enabled, the kernel will attempt to enable the best
1921db616173SMichal Hocko	  possible TAA mitigation setting depending on the microcode available
1922db616173SMichal Hocko	  for the particular machine.
1923db616173SMichal Hocko
1924db616173SMichal Hocko	  This option allows to set the default tsx mode between tsx=on, =off
1925db616173SMichal Hocko	  and =auto. See Documentation/admin-guide/kernel-parameters.txt for more
1926db616173SMichal Hocko	  details.
1927db616173SMichal Hocko
1928db616173SMichal Hocko	  Say off if not sure, auto if TSX is in use but it should be used on safe
1929db616173SMichal Hocko	  platforms or on if TSX is in use and the security aspect of tsx is not
1930db616173SMichal Hocko	  relevant.
1931db616173SMichal Hocko
1932db616173SMichal Hockoconfig X86_INTEL_TSX_MODE_OFF
1933db616173SMichal Hocko	bool "off"
1934db616173SMichal Hocko	help
1935db616173SMichal Hocko	  TSX is disabled if possible - equals to tsx=off command line parameter.
1936db616173SMichal Hocko
1937db616173SMichal Hockoconfig X86_INTEL_TSX_MODE_ON
1938db616173SMichal Hocko	bool "on"
1939db616173SMichal Hocko	help
1940db616173SMichal Hocko	  TSX is always enabled on TSX capable HW - equals the tsx=on command
1941db616173SMichal Hocko	  line parameter.
1942db616173SMichal Hocko
1943db616173SMichal Hockoconfig X86_INTEL_TSX_MODE_AUTO
1944db616173SMichal Hocko	bool "auto"
1945db616173SMichal Hocko	help
1946db616173SMichal Hocko	  TSX is enabled on TSX capable HW that is believed to be safe against
1947db616173SMichal Hocko	  side channel attacks- equals the tsx=auto command line parameter.
1948db616173SMichal Hockoendchoice
1949db616173SMichal Hocko
1950506f1d07SSam Ravnborgconfig EFI
19519ba16087SJan Beulich	bool "EFI runtime service support"
19525b83683fSHuang, Ying	depends on ACPI
1953f6ce5002SSergey Vlasov	select UCS2_STRING
1954022ee6c5SArd Biesheuvel	select EFI_RUNTIME_WRAPPERS
1955506f1d07SSam Ravnborg	---help---
19568b2cb7a8SHuang, Ying	  This enables the kernel to use EFI runtime services that are
1957506f1d07SSam Ravnborg	  available (such as the EFI variable services).
1958506f1d07SSam Ravnborg
19598b2cb7a8SHuang, Ying	  This option is only useful on systems that have EFI firmware.
19608b2cb7a8SHuang, Ying	  In addition, you should use the latest ELILO loader available
19618b2cb7a8SHuang, Ying	  at <http://elilo.sourceforge.net> in order to take advantage
19628b2cb7a8SHuang, Ying	  of EFI runtime services. However, even with this option, the
19638b2cb7a8SHuang, Ying	  resultant kernel should continue to boot on existing non-EFI
19648b2cb7a8SHuang, Ying	  platforms.
1965506f1d07SSam Ravnborg
1966291f3632SMatt Flemingconfig EFI_STUB
1967291f3632SMatt Fleming	bool "EFI stub support"
1968b16d8c23SMatt Fleming	depends on EFI && !X86_USE_3DNOW
19698f24f8c2SArd Biesheuvel	depends on $(cc-option,-mabi=ms) || X86_32
19707b2a583aSMatt Fleming	select RELOCATABLE
1971291f3632SMatt Fleming	---help---
1972291f3632SMatt Fleming	  This kernel feature allows a bzImage to be loaded directly
1973291f3632SMatt Fleming	  by EFI firmware without the use of a bootloader.
1974291f3632SMatt Fleming
19754f4cfa6cSMauro Carvalho Chehab	  See Documentation/admin-guide/efi-stub.rst for more information.
19760c759662SMatt Fleming
19777d453eeeSMatt Flemingconfig EFI_MIXED
19787d453eeeSMatt Fleming	bool "EFI mixed-mode support"
19797d453eeeSMatt Fleming	depends on EFI_STUB && X86_64
19807d453eeeSMatt Fleming	---help---
19817d453eeeSMatt Fleming	   Enabling this feature allows a 64-bit kernel to be booted
19827d453eeeSMatt Fleming	   on a 32-bit firmware, provided that your CPU supports 64-bit
19837d453eeeSMatt Fleming	   mode.
19847d453eeeSMatt Fleming
19857d453eeeSMatt Fleming	   Note that it is not possible to boot a mixed-mode enabled
19867d453eeeSMatt Fleming	   kernel via the EFI boot stub - a bootloader that supports
19877d453eeeSMatt Fleming	   the EFI handover protocol must be used.
19887d453eeeSMatt Fleming
19897d453eeeSMatt Fleming	   If unsure, say N.
19907d453eeeSMatt Fleming
1991506f1d07SSam Ravnborgconfig SECCOMP
19923c2362e6SHarvey Harrison	def_bool y
19933c2362e6SHarvey Harrison	prompt "Enable seccomp to safely compute untrusted bytecode"
19948f9ca475SIngo Molnar	---help---
1995506f1d07SSam Ravnborg	  This kernel feature is useful for number crunching applications
1996506f1d07SSam Ravnborg	  that may need to compute untrusted bytecode during their
1997506f1d07SSam Ravnborg	  execution. By using pipes or other transports made available to
1998506f1d07SSam Ravnborg	  the process as file descriptors supporting the read/write
1999506f1d07SSam Ravnborg	  syscalls, it's possible to isolate those applications in
2000506f1d07SSam Ravnborg	  their own address space using seccomp. Once seccomp is
20019c0bbee8SAlexey Dobriyan	  enabled via prctl(PR_SET_SECCOMP), it cannot be disabled
2002506f1d07SSam Ravnborg	  and the task is only allowed to execute a few safe syscalls
2003506f1d07SSam Ravnborg	  defined by each seccomp mode.
2004506f1d07SSam Ravnborg
2005506f1d07SSam Ravnborg	  If unsure, say Y. Only embedded should say N here.
2006506f1d07SSam Ravnborg
20078636a1f9SMasahiro Yamadasource "kernel/Kconfig.hz"
2008506f1d07SSam Ravnborg
2009506f1d07SSam Ravnborgconfig KEXEC
2010506f1d07SSam Ravnborg	bool "kexec system call"
20112965faa5SDave Young	select KEXEC_CORE
20128f9ca475SIngo Molnar	---help---
2013506f1d07SSam Ravnborg	  kexec is a system call that implements the ability to shutdown your
2014506f1d07SSam Ravnborg	  current kernel, and to start another kernel.  It is like a reboot
2015506f1d07SSam Ravnborg	  but it is independent of the system firmware.   And like a reboot
2016506f1d07SSam Ravnborg	  you can start any kernel with it, not just Linux.
2017506f1d07SSam Ravnborg
2018506f1d07SSam Ravnborg	  The name comes from the similarity to the exec system call.
2019506f1d07SSam Ravnborg
2020506f1d07SSam Ravnborg	  It is an ongoing process to be certain the hardware in a machine
2021506f1d07SSam Ravnborg	  is properly shutdown, so do not be surprised if this code does not
2022bf220695SGeert Uytterhoeven	  initially work for you.  As of this writing the exact hardware
2023bf220695SGeert Uytterhoeven	  interface is strongly in flux, so no good recommendation can be
2024bf220695SGeert Uytterhoeven	  made.
2025506f1d07SSam Ravnborg
202674ca317cSVivek Goyalconfig KEXEC_FILE
202774ca317cSVivek Goyal	bool "kexec file based system call"
20282965faa5SDave Young	select KEXEC_CORE
202974ca317cSVivek Goyal	select BUILD_BIN2C
203074ca317cSVivek Goyal	depends on X86_64
203174ca317cSVivek Goyal	depends on CRYPTO=y
203274ca317cSVivek Goyal	depends on CRYPTO_SHA256=y
203374ca317cSVivek Goyal	---help---
203474ca317cSVivek Goyal	  This is new version of kexec system call. This system call is
203574ca317cSVivek Goyal	  file based and takes file descriptors as system call argument
203674ca317cSVivek Goyal	  for kernel and initramfs as opposed to list of segments as
203774ca317cSVivek Goyal	  accepted by previous system call.
203874ca317cSVivek Goyal
2039b799a09fSAKASHI Takahiroconfig ARCH_HAS_KEXEC_PURGATORY
2040b799a09fSAKASHI Takahiro	def_bool KEXEC_FILE
2041b799a09fSAKASHI Takahiro
204299d5cadfSJiri Bohacconfig KEXEC_SIG
20438e7d8381SVivek Goyal	bool "Verify kernel signature during kexec_file_load() syscall"
204474ca317cSVivek Goyal	depends on KEXEC_FILE
20458e7d8381SVivek Goyal	---help---
204699d5cadfSJiri Bohac
204799d5cadfSJiri Bohac	  This option makes the kexec_file_load() syscall check for a valid
204899d5cadfSJiri Bohac	  signature of the kernel image.  The image can still be loaded without
204999d5cadfSJiri Bohac	  a valid signature unless you also enable KEXEC_SIG_FORCE, though if
205099d5cadfSJiri Bohac	  there's a signature that we can check, then it must be valid.
205199d5cadfSJiri Bohac
205299d5cadfSJiri Bohac	  In addition to this option, you need to enable signature
205399d5cadfSJiri Bohac	  verification for the corresponding kernel image type being
205499d5cadfSJiri Bohac	  loaded in order for this to work.
205599d5cadfSJiri Bohac
205699d5cadfSJiri Bohacconfig KEXEC_SIG_FORCE
205799d5cadfSJiri Bohac	bool "Require a valid signature in kexec_file_load() syscall"
205899d5cadfSJiri Bohac	depends on KEXEC_SIG
205999d5cadfSJiri Bohac	---help---
20608e7d8381SVivek Goyal	  This option makes kernel signature verification mandatory for
2061d8eb8940SBorislav Petkov	  the kexec_file_load() syscall.
20628e7d8381SVivek Goyal
20638e7d8381SVivek Goyalconfig KEXEC_BZIMAGE_VERIFY_SIG
20648e7d8381SVivek Goyal	bool "Enable bzImage signature verification support"
206599d5cadfSJiri Bohac	depends on KEXEC_SIG
20668e7d8381SVivek Goyal	depends on SIGNED_PE_FILE_VERIFICATION
20678e7d8381SVivek Goyal	select SYSTEM_TRUSTED_KEYRING
20688e7d8381SVivek Goyal	---help---
20698e7d8381SVivek Goyal	  Enable bzImage signature verification support.
20708e7d8381SVivek Goyal
2071506f1d07SSam Ravnborgconfig CRASH_DUMP
207204b69447SPavel Machek	bool "kernel crash dumps"
2073506f1d07SSam Ravnborg	depends on X86_64 || (X86_32 && HIGHMEM)
20748f9ca475SIngo Molnar	---help---
2075506f1d07SSam Ravnborg	  Generate crash dump after being started by kexec.
2076506f1d07SSam Ravnborg	  This should be normally only set in special crash dump kernels
2077506f1d07SSam Ravnborg	  which are loaded in the main kernel with kexec-tools into
2078506f1d07SSam Ravnborg	  a specially reserved region and then later executed after
2079506f1d07SSam Ravnborg	  a crash by kdump/kexec. The crash dump kernel must be compiled
2080506f1d07SSam Ravnborg	  to a memory address not used by the main kernel or BIOS using
2081506f1d07SSam Ravnborg	  PHYSICAL_START, or it must be built as a relocatable image
2082506f1d07SSam Ravnborg	  (CONFIG_RELOCATABLE=y).
2083330d4810SMauro Carvalho Chehab	  For more details see Documentation/admin-guide/kdump/kdump.rst
2084506f1d07SSam Ravnborg
20853ab83521SHuang Yingconfig KEXEC_JUMP
20866ea30386SKees Cook	bool "kexec jump"
2087fee7b0d8SHuang Ying	depends on KEXEC && HIBERNATION
20888f9ca475SIngo Molnar	---help---
208989081d17SHuang Ying	  Jump between original kernel and kexeced kernel and invoke
209089081d17SHuang Ying	  code in physical address mode via KEXEC
20913ab83521SHuang Ying
2092506f1d07SSam Ravnborgconfig PHYSICAL_START
20936a108a14SDavid Rientjes	hex "Physical address where the kernel is loaded" if (EXPERT || CRASH_DUMP)
2094ceefccc9SH. Peter Anvin	default "0x1000000"
20958f9ca475SIngo Molnar	---help---
2096506f1d07SSam Ravnborg	  This gives the physical address where the kernel is loaded.
2097506f1d07SSam Ravnborg
2098506f1d07SSam Ravnborg	  If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then
2099506f1d07SSam Ravnborg	  bzImage will decompress itself to above physical address and
2100506f1d07SSam Ravnborg	  run from there. Otherwise, bzImage will run from the address where
2101506f1d07SSam Ravnborg	  it has been loaded by the boot loader and will ignore above physical
2102506f1d07SSam Ravnborg	  address.
2103506f1d07SSam Ravnborg
2104506f1d07SSam Ravnborg	  In normal kdump cases one does not have to set/change this option
2105506f1d07SSam Ravnborg	  as now bzImage can be compiled as a completely relocatable image
2106506f1d07SSam Ravnborg	  (CONFIG_RELOCATABLE=y) and be used to load and run from a different
2107506f1d07SSam Ravnborg	  address. This option is mainly useful for the folks who don't want
2108506f1d07SSam Ravnborg	  to use a bzImage for capturing the crash dump and want to use a
2109506f1d07SSam Ravnborg	  vmlinux instead. vmlinux is not relocatable hence a kernel needs
2110506f1d07SSam Ravnborg	  to be specifically compiled to run from a specific memory area
2111506f1d07SSam Ravnborg	  (normally a reserved region) and this option comes handy.
2112506f1d07SSam Ravnborg
2113ceefccc9SH. Peter Anvin	  So if you are using bzImage for capturing the crash dump,
2114ceefccc9SH. Peter Anvin	  leave the value here unchanged to 0x1000000 and set
2115ceefccc9SH. Peter Anvin	  CONFIG_RELOCATABLE=y.  Otherwise if you plan to use vmlinux
2116ceefccc9SH. Peter Anvin	  for capturing the crash dump change this value to start of
2117ceefccc9SH. Peter Anvin	  the reserved region.  In other words, it can be set based on
2118ceefccc9SH. Peter Anvin	  the "X" value as specified in the "crashkernel=YM@XM"
2119ceefccc9SH. Peter Anvin	  command line boot parameter passed to the panic-ed
2120330d4810SMauro Carvalho Chehab	  kernel. Please take a look at Documentation/admin-guide/kdump/kdump.rst
2121ceefccc9SH. Peter Anvin	  for more details about crash dumps.
2122506f1d07SSam Ravnborg
2123506f1d07SSam Ravnborg	  Usage of bzImage for capturing the crash dump is recommended as
2124506f1d07SSam Ravnborg	  one does not have to build two kernels. Same kernel can be used
2125506f1d07SSam Ravnborg	  as production kernel and capture kernel. Above option should have
2126506f1d07SSam Ravnborg	  gone away after relocatable bzImage support is introduced. But it
2127506f1d07SSam Ravnborg	  is present because there are users out there who continue to use
2128506f1d07SSam Ravnborg	  vmlinux for dump capture. This option should go away down the
2129506f1d07SSam Ravnborg	  line.
2130506f1d07SSam Ravnborg
2131506f1d07SSam Ravnborg	  Don't change this unless you know what you are doing.
2132506f1d07SSam Ravnborg
2133506f1d07SSam Ravnborgconfig RELOCATABLE
213426717808SH. Peter Anvin	bool "Build a relocatable kernel"
213526717808SH. Peter Anvin	default y
21368f9ca475SIngo Molnar	---help---
2137506f1d07SSam Ravnborg	  This builds a kernel image that retains relocation information
2138506f1d07SSam Ravnborg	  so it can be loaded someplace besides the default 1MB.
2139506f1d07SSam Ravnborg	  The relocations tend to make the kernel binary about 10% larger,
2140506f1d07SSam Ravnborg	  but are discarded at runtime.
2141506f1d07SSam Ravnborg
2142506f1d07SSam Ravnborg	  One use is for the kexec on panic case where the recovery kernel
2143506f1d07SSam Ravnborg	  must live at a different physical address than the primary
2144506f1d07SSam Ravnborg	  kernel.
2145506f1d07SSam Ravnborg
2146506f1d07SSam Ravnborg	  Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address
2147506f1d07SSam Ravnborg	  it has been loaded at and the compile time physical address
21488ab3820fSKees Cook	  (CONFIG_PHYSICAL_START) is used as the minimum location.
2149506f1d07SSam Ravnborg
21508ab3820fSKees Cookconfig RANDOMIZE_BASE
2151e8581e3dSBaoquan He	bool "Randomize the address of the kernel image (KASLR)"
21528ab3820fSKees Cook	depends on RELOCATABLE
21536807c846SIngo Molnar	default y
21548ab3820fSKees Cook	---help---
2155e8581e3dSBaoquan He	  In support of Kernel Address Space Layout Randomization (KASLR),
2156e8581e3dSBaoquan He	  this randomizes the physical address at which the kernel image
2157e8581e3dSBaoquan He	  is decompressed and the virtual address where the kernel
2158e8581e3dSBaoquan He	  image is mapped, as a security feature that deters exploit
2159e8581e3dSBaoquan He	  attempts relying on knowledge of the location of kernel
2160e8581e3dSBaoquan He	  code internals.
2161e8581e3dSBaoquan He
2162ed9f007eSKees Cook	  On 64-bit, the kernel physical and virtual addresses are
2163ed9f007eSKees Cook	  randomized separately. The physical address will be anywhere
2164ed9f007eSKees Cook	  between 16MB and the top of physical memory (up to 64TB). The
2165ed9f007eSKees Cook	  virtual address will be randomized from 16MB up to 1GB (9 bits
2166ed9f007eSKees Cook	  of entropy). Note that this also reduces the memory space
2167ed9f007eSKees Cook	  available to kernel modules from 1.5GB to 1GB.
2168ed9f007eSKees Cook
2169ed9f007eSKees Cook	  On 32-bit, the kernel physical and virtual addresses are
2170ed9f007eSKees Cook	  randomized together. They will be randomized from 16MB up to
2171ed9f007eSKees Cook	  512MB (8 bits of entropy).
21728ab3820fSKees Cook
2173a653f356SKees Cook	  Entropy is generated using the RDRAND instruction if it is
2174e8581e3dSBaoquan He	  supported. If RDTSC is supported, its value is mixed into
2175e8581e3dSBaoquan He	  the entropy pool as well. If neither RDRAND nor RDTSC are
2176ed9f007eSKees Cook	  supported, then entropy is read from the i8254 timer. The
2177ed9f007eSKees Cook	  usable entropy is limited by the kernel being built using
2178ed9f007eSKees Cook	  2GB addressing, and that PHYSICAL_ALIGN must be at a
2179ed9f007eSKees Cook	  minimum of 2MB. As a result, only 10 bits of entropy are
2180ed9f007eSKees Cook	  theoretically possible, but the implementations are further
2181ed9f007eSKees Cook	  limited due to memory layouts.
2182e8581e3dSBaoquan He
21836807c846SIngo Molnar	  If unsure, say Y.
2184da2b6fb9SKees Cook
21858ab3820fSKees Cook# Relocation on x86 needs some additional build support
2186845adf72SH. Peter Anvinconfig X86_NEED_RELOCS
2187845adf72SH. Peter Anvin	def_bool y
21888ab3820fSKees Cook	depends on RANDOMIZE_BASE || (X86_32 && RELOCATABLE)
2189845adf72SH. Peter Anvin
2190506f1d07SSam Ravnborgconfig PHYSICAL_ALIGN
2191a0215061SKees Cook	hex "Alignment value to which kernel should be aligned"
21928ab3820fSKees Cook	default "0x200000"
2193a0215061SKees Cook	range 0x2000 0x1000000 if X86_32
2194a0215061SKees Cook	range 0x200000 0x1000000 if X86_64
21958f9ca475SIngo Molnar	---help---
2196506f1d07SSam Ravnborg	  This value puts the alignment restrictions on physical address
2197506f1d07SSam Ravnborg	  where kernel is loaded and run from. Kernel is compiled for an
2198506f1d07SSam Ravnborg	  address which meets above alignment restriction.
2199506f1d07SSam Ravnborg
2200506f1d07SSam Ravnborg	  If bootloader loads the kernel at a non-aligned address and
2201506f1d07SSam Ravnborg	  CONFIG_RELOCATABLE is set, kernel will move itself to nearest
2202506f1d07SSam Ravnborg	  address aligned to above value and run from there.
2203506f1d07SSam Ravnborg
2204506f1d07SSam Ravnborg	  If bootloader loads the kernel at a non-aligned address and
2205506f1d07SSam Ravnborg	  CONFIG_RELOCATABLE is not set, kernel will ignore the run time
2206506f1d07SSam Ravnborg	  load address and decompress itself to the address it has been
2207506f1d07SSam Ravnborg	  compiled for and run from there. The address for which kernel is
2208506f1d07SSam Ravnborg	  compiled already meets above alignment restrictions. Hence the
2209506f1d07SSam Ravnborg	  end result is that kernel runs from a physical address meeting
2210506f1d07SSam Ravnborg	  above alignment restrictions.
2211506f1d07SSam Ravnborg
2212a0215061SKees Cook	  On 32-bit this value must be a multiple of 0x2000. On 64-bit
2213a0215061SKees Cook	  this value must be a multiple of 0x200000.
2214a0215061SKees Cook
2215506f1d07SSam Ravnborg	  Don't change this unless you know what you are doing.
2216506f1d07SSam Ravnborg
2217eedb92abSKirill A. Shutemovconfig DYNAMIC_MEMORY_LAYOUT
2218eedb92abSKirill A. Shutemov	bool
2219eedb92abSKirill A. Shutemov	---help---
2220eedb92abSKirill A. Shutemov	  This option makes base addresses of vmalloc and vmemmap as well as
2221eedb92abSKirill A. Shutemov	  __PAGE_OFFSET movable during boot.
2222eedb92abSKirill A. Shutemov
22230483e1faSThomas Garnierconfig RANDOMIZE_MEMORY
22240483e1faSThomas Garnier	bool "Randomize the kernel memory sections"
22250483e1faSThomas Garnier	depends on X86_64
22260483e1faSThomas Garnier	depends on RANDOMIZE_BASE
2227eedb92abSKirill A. Shutemov	select DYNAMIC_MEMORY_LAYOUT
22280483e1faSThomas Garnier	default RANDOMIZE_BASE
22290483e1faSThomas Garnier	---help---
22300483e1faSThomas Garnier	   Randomizes the base virtual address of kernel memory sections
22310483e1faSThomas Garnier	   (physical memory mapping, vmalloc & vmemmap). This security feature
22320483e1faSThomas Garnier	   makes exploits relying on predictable memory locations less reliable.
22330483e1faSThomas Garnier
22340483e1faSThomas Garnier	   The order of allocations remains unchanged. Entropy is generated in
22350483e1faSThomas Garnier	   the same way as RANDOMIZE_BASE. Current implementation in the optimal
22360483e1faSThomas Garnier	   configuration have in average 30,000 different possible virtual
22370483e1faSThomas Garnier	   addresses for each memory section.
22380483e1faSThomas Garnier
22396807c846SIngo Molnar	   If unsure, say Y.
22400483e1faSThomas Garnier
224190397a41SThomas Garnierconfig RANDOMIZE_MEMORY_PHYSICAL_PADDING
224290397a41SThomas Garnier	hex "Physical memory mapping padding" if EXPERT
224390397a41SThomas Garnier	depends on RANDOMIZE_MEMORY
224490397a41SThomas Garnier	default "0xa" if MEMORY_HOTPLUG
224590397a41SThomas Garnier	default "0x0"
224690397a41SThomas Garnier	range 0x1 0x40 if MEMORY_HOTPLUG
224790397a41SThomas Garnier	range 0x0 0x40
224890397a41SThomas Garnier	---help---
224990397a41SThomas Garnier	   Define the padding in terabytes added to the existing physical
225090397a41SThomas Garnier	   memory size during kernel memory randomization. It is useful
225190397a41SThomas Garnier	   for memory hotplug support but reduces the entropy available for
225290397a41SThomas Garnier	   address randomization.
225390397a41SThomas Garnier
225490397a41SThomas Garnier	   If unsure, leave at the default value.
225590397a41SThomas Garnier
2256506f1d07SSam Ravnborgconfig HOTPLUG_CPU
2257bebd024eSThomas Gleixner	def_bool y
225840b31360SStephen Rothwell	depends on SMP
2259506f1d07SSam Ravnborg
226080aa1dffSFenghua Yuconfig BOOTPARAM_HOTPLUG_CPU0
226180aa1dffSFenghua Yu	bool "Set default setting of cpu0_hotpluggable"
22622c922cd0SKees Cook	depends on HOTPLUG_CPU
226380aa1dffSFenghua Yu	---help---
226480aa1dffSFenghua Yu	  Set whether default state of cpu0_hotpluggable is on or off.
226580aa1dffSFenghua Yu
226680aa1dffSFenghua Yu	  Say Y here to enable CPU0 hotplug by default. If this switch
226780aa1dffSFenghua Yu	  is turned on, there is no need to give cpu0_hotplug kernel
226880aa1dffSFenghua Yu	  parameter and the CPU0 hotplug feature is enabled by default.
226980aa1dffSFenghua Yu
227080aa1dffSFenghua Yu	  Please note: there are two known CPU0 dependencies if you want
227180aa1dffSFenghua Yu	  to enable the CPU0 hotplug feature either by this switch or by
227280aa1dffSFenghua Yu	  cpu0_hotplug kernel parameter.
227380aa1dffSFenghua Yu
227480aa1dffSFenghua Yu	  First, resume from hibernate or suspend always starts from CPU0.
227580aa1dffSFenghua Yu	  So hibernate and suspend are prevented if CPU0 is offline.
227680aa1dffSFenghua Yu
227780aa1dffSFenghua Yu	  Second dependency is PIC interrupts always go to CPU0. CPU0 can not
227880aa1dffSFenghua Yu	  offline if any interrupt can not migrate out of CPU0. There may
227980aa1dffSFenghua Yu	  be other CPU0 dependencies.
228080aa1dffSFenghua Yu
228180aa1dffSFenghua Yu	  Please make sure the dependencies are under your control before
228280aa1dffSFenghua Yu	  you enable this feature.
228380aa1dffSFenghua Yu
228480aa1dffSFenghua Yu	  Say N if you don't want to enable CPU0 hotplug feature by default.
228580aa1dffSFenghua Yu	  You still can enable the CPU0 hotplug feature at boot by kernel
228680aa1dffSFenghua Yu	  parameter cpu0_hotplug.
228780aa1dffSFenghua Yu
2288a71c8bc5SFenghua Yuconfig DEBUG_HOTPLUG_CPU0
2289a71c8bc5SFenghua Yu	def_bool n
2290a71c8bc5SFenghua Yu	prompt "Debug CPU0 hotplug"
22912c922cd0SKees Cook	depends on HOTPLUG_CPU
2292a71c8bc5SFenghua Yu	---help---
2293a71c8bc5SFenghua Yu	  Enabling this option offlines CPU0 (if CPU0 can be offlined) as
2294a71c8bc5SFenghua Yu	  soon as possible and boots up userspace with CPU0 offlined. User
2295a71c8bc5SFenghua Yu	  can online CPU0 back after boot time.
2296a71c8bc5SFenghua Yu
2297a71c8bc5SFenghua Yu	  To debug CPU0 hotplug, you need to enable CPU0 offline/online
2298a71c8bc5SFenghua Yu	  feature by either turning on CONFIG_BOOTPARAM_HOTPLUG_CPU0 during
2299a71c8bc5SFenghua Yu	  compilation or giving cpu0_hotplug kernel parameter at boot.
2300a71c8bc5SFenghua Yu
2301a71c8bc5SFenghua Yu	  If unsure, say N.
2302a71c8bc5SFenghua Yu
2303506f1d07SSam Ravnborgconfig COMPAT_VDSO
2304b0b49f26SAndy Lutomirski	def_bool n
2305b0b49f26SAndy Lutomirski	prompt "Disable the 32-bit vDSO (needed for glibc 2.3.3)"
2306953fee1dSIngo Molnar	depends on COMPAT_32
23078f9ca475SIngo Molnar	---help---
2308b0b49f26SAndy Lutomirski	  Certain buggy versions of glibc will crash if they are
2309b0b49f26SAndy Lutomirski	  presented with a 32-bit vDSO that is not mapped at the address
2310b0b49f26SAndy Lutomirski	  indicated in its segment table.
2311e84446deSRandy Dunlap
2312b0b49f26SAndy Lutomirski	  The bug was introduced by f866314b89d56845f55e6f365e18b31ec978ec3a
2313b0b49f26SAndy Lutomirski	  and fixed by 3b3ddb4f7db98ec9e912ccdf54d35df4aa30e04a and
2314b0b49f26SAndy Lutomirski	  49ad572a70b8aeb91e57483a11dd1b77e31c4468.  Glibc 2.3.3 is
2315b0b49f26SAndy Lutomirski	  the only released version with the bug, but OpenSUSE 9
2316b0b49f26SAndy Lutomirski	  contains a buggy "glibc 2.3.2".
2317506f1d07SSam Ravnborg
2318b0b49f26SAndy Lutomirski	  The symptom of the bug is that everything crashes on startup, saying:
2319b0b49f26SAndy Lutomirski	  dl_main: Assertion `(void *) ph->p_vaddr == _rtld_local._dl_sysinfo_dso' failed!
2320b0b49f26SAndy Lutomirski
2321b0b49f26SAndy Lutomirski	  Saying Y here changes the default value of the vdso32 boot
2322b0b49f26SAndy Lutomirski	  option from 1 to 0, which turns off the 32-bit vDSO entirely.
2323b0b49f26SAndy Lutomirski	  This works around the glibc bug but hurts performance.
2324b0b49f26SAndy Lutomirski
2325b0b49f26SAndy Lutomirski	  If unsure, say N: if you are compiling your own kernel, you
2326b0b49f26SAndy Lutomirski	  are unlikely to be using a buggy version of glibc.
2327506f1d07SSam Ravnborg
23283dc33bd3SKees Cookchoice
23293dc33bd3SKees Cook	prompt "vsyscall table for legacy applications"
23303dc33bd3SKees Cook	depends on X86_64
2331625b7b7fSAndy Lutomirski	default LEGACY_VSYSCALL_XONLY
23323dc33bd3SKees Cook	help
23333dc33bd3SKees Cook	  Legacy user code that does not know how to find the vDSO expects
23343dc33bd3SKees Cook	  to be able to issue three syscalls by calling fixed addresses in
23353dc33bd3SKees Cook	  kernel space. Since this location is not randomized with ASLR,
23363dc33bd3SKees Cook	  it can be used to assist security vulnerability exploitation.
23373dc33bd3SKees Cook
23383dc33bd3SKees Cook	  This setting can be changed at boot time via the kernel command
2339bd49e16eSAndy Lutomirski	  line parameter vsyscall=[emulate|xonly|none].
23403dc33bd3SKees Cook
23413dc33bd3SKees Cook	  On a system with recent enough glibc (2.14 or newer) and no
23423dc33bd3SKees Cook	  static binaries, you can say None without a performance penalty
23433dc33bd3SKees Cook	  to improve security.
23443dc33bd3SKees Cook
2345bd49e16eSAndy Lutomirski	  If unsure, select "Emulate execution only".
23463dc33bd3SKees Cook
23473dc33bd3SKees Cook	config LEGACY_VSYSCALL_EMULATE
2348bd49e16eSAndy Lutomirski		bool "Full emulation"
23493dc33bd3SKees Cook		help
2350bd49e16eSAndy Lutomirski		  The kernel traps and emulates calls into the fixed vsyscall
2351bd49e16eSAndy Lutomirski		  address mapping. This makes the mapping non-executable, but
2352bd49e16eSAndy Lutomirski		  it still contains readable known contents, which could be
2353bd49e16eSAndy Lutomirski		  used in certain rare security vulnerability exploits. This
2354bd49e16eSAndy Lutomirski		  configuration is recommended when using legacy userspace
2355bd49e16eSAndy Lutomirski		  that still uses vsyscalls along with legacy binary
2356bd49e16eSAndy Lutomirski		  instrumentation tools that require code to be readable.
2357bd49e16eSAndy Lutomirski
2358bd49e16eSAndy Lutomirski		  An example of this type of legacy userspace is running
2359bd49e16eSAndy Lutomirski		  Pin on an old binary that still uses vsyscalls.
2360bd49e16eSAndy Lutomirski
2361bd49e16eSAndy Lutomirski	config LEGACY_VSYSCALL_XONLY
2362bd49e16eSAndy Lutomirski		bool "Emulate execution only"
2363bd49e16eSAndy Lutomirski		help
2364bd49e16eSAndy Lutomirski		  The kernel traps and emulates calls into the fixed vsyscall
2365bd49e16eSAndy Lutomirski		  address mapping and does not allow reads.  This
2366bd49e16eSAndy Lutomirski		  configuration is recommended when userspace might use the
2367bd49e16eSAndy Lutomirski		  legacy vsyscall area but support for legacy binary
2368bd49e16eSAndy Lutomirski		  instrumentation of legacy code is not needed.  It mitigates
2369bd49e16eSAndy Lutomirski		  certain uses of the vsyscall area as an ASLR-bypassing
2370bd49e16eSAndy Lutomirski		  buffer.
23713dc33bd3SKees Cook
23723dc33bd3SKees Cook	config LEGACY_VSYSCALL_NONE
23733dc33bd3SKees Cook		bool "None"
23743dc33bd3SKees Cook		help
23753dc33bd3SKees Cook		  There will be no vsyscall mapping at all. This will
23763dc33bd3SKees Cook		  eliminate any risk of ASLR bypass due to the vsyscall
23773dc33bd3SKees Cook		  fixed address mapping. Attempts to use the vsyscalls
23783dc33bd3SKees Cook		  will be reported to dmesg, so that either old or
23793dc33bd3SKees Cook		  malicious userspace programs can be identified.
23803dc33bd3SKees Cook
23813dc33bd3SKees Cookendchoice
23823dc33bd3SKees Cook
2383516cbf37STim Birdconfig CMDLINE_BOOL
2384516cbf37STim Bird	bool "Built-in kernel command line"
23858f9ca475SIngo Molnar	---help---
2386516cbf37STim Bird	  Allow for specifying boot arguments to the kernel at
2387516cbf37STim Bird	  build time.  On some systems (e.g. embedded ones), it is
2388516cbf37STim Bird	  necessary or convenient to provide some or all of the
2389516cbf37STim Bird	  kernel boot arguments with the kernel itself (that is,
2390516cbf37STim Bird	  to not rely on the boot loader to provide them.)
2391516cbf37STim Bird
2392516cbf37STim Bird	  To compile command line arguments into the kernel,
2393516cbf37STim Bird	  set this option to 'Y', then fill in the
239469711ca1SSébastien Hinderer	  boot arguments in CONFIG_CMDLINE.
2395516cbf37STim Bird
2396516cbf37STim Bird	  Systems with fully functional boot loaders (i.e. non-embedded)
2397516cbf37STim Bird	  should leave this option set to 'N'.
2398516cbf37STim Bird
2399516cbf37STim Birdconfig CMDLINE
2400516cbf37STim Bird	string "Built-in kernel command string"
2401516cbf37STim Bird	depends on CMDLINE_BOOL
2402516cbf37STim Bird	default ""
24038f9ca475SIngo Molnar	---help---
2404516cbf37STim Bird	  Enter arguments here that should be compiled into the kernel
2405516cbf37STim Bird	  image and used at boot time.  If the boot loader provides a
2406516cbf37STim Bird	  command line at boot time, it is appended to this string to
2407516cbf37STim Bird	  form the full kernel command line, when the system boots.
2408516cbf37STim Bird
2409516cbf37STim Bird	  However, you can use the CONFIG_CMDLINE_OVERRIDE option to
2410516cbf37STim Bird	  change this behavior.
2411516cbf37STim Bird
2412516cbf37STim Bird	  In most cases, the command line (whether built-in or provided
2413516cbf37STim Bird	  by the boot loader) should specify the device for the root
2414516cbf37STim Bird	  file system.
2415516cbf37STim Bird
2416516cbf37STim Birdconfig CMDLINE_OVERRIDE
2417516cbf37STim Bird	bool "Built-in command line overrides boot loader arguments"
2418645e6466SAnders Roxell	depends on CMDLINE_BOOL && CMDLINE != ""
24198f9ca475SIngo Molnar	---help---
2420516cbf37STim Bird	  Set this option to 'Y' to have the kernel ignore the boot loader
2421516cbf37STim Bird	  command line, and use ONLY the built-in command line.
2422516cbf37STim Bird
2423516cbf37STim Bird	  This is used to work around broken boot loaders.  This should
2424516cbf37STim Bird	  be set to 'N' under normal conditions.
2425516cbf37STim Bird
2426a5b9e5a2SAndy Lutomirskiconfig MODIFY_LDT_SYSCALL
2427a5b9e5a2SAndy Lutomirski	bool "Enable the LDT (local descriptor table)" if EXPERT
2428a5b9e5a2SAndy Lutomirski	default y
2429a5b9e5a2SAndy Lutomirski	---help---
2430a5b9e5a2SAndy Lutomirski	  Linux can allow user programs to install a per-process x86
2431a5b9e5a2SAndy Lutomirski	  Local Descriptor Table (LDT) using the modify_ldt(2) system
2432a5b9e5a2SAndy Lutomirski	  call.  This is required to run 16-bit or segmented code such as
2433a5b9e5a2SAndy Lutomirski	  DOSEMU or some Wine programs.  It is also used by some very old
2434a5b9e5a2SAndy Lutomirski	  threading libraries.
2435a5b9e5a2SAndy Lutomirski
2436a5b9e5a2SAndy Lutomirski	  Enabling this feature adds a small amount of overhead to
2437a5b9e5a2SAndy Lutomirski	  context switches and increases the low-level kernel attack
2438a5b9e5a2SAndy Lutomirski	  surface.  Disabling it removes the modify_ldt(2) system call.
2439a5b9e5a2SAndy Lutomirski
2440a5b9e5a2SAndy Lutomirski	  Saying 'N' here may make sense for embedded or server kernels.
2441a5b9e5a2SAndy Lutomirski
2442b700e7f0SSeth Jenningssource "kernel/livepatch/Kconfig"
2443b700e7f0SSeth Jennings
2444506f1d07SSam Ravnborgendmenu
2445506f1d07SSam Ravnborg
24463072e413SMichal Hockoconfig ARCH_HAS_ADD_PAGES
24473072e413SMichal Hocko	def_bool y
24483072e413SMichal Hocko	depends on X86_64 && ARCH_ENABLE_MEMORY_HOTPLUG
24493072e413SMichal Hocko
2450506f1d07SSam Ravnborgconfig ARCH_ENABLE_MEMORY_HOTPLUG
2451506f1d07SSam Ravnborg	def_bool y
2452506f1d07SSam Ravnborg	depends on X86_64 || (X86_32 && HIGHMEM)
2453506f1d07SSam Ravnborg
245435551053SGary Hadeconfig ARCH_ENABLE_MEMORY_HOTREMOVE
245535551053SGary Hade	def_bool y
245635551053SGary Hade	depends on MEMORY_HOTPLUG
245735551053SGary Hade
2458e534c7c5SLee Schermerhornconfig USE_PERCPU_NUMA_NODE_ID
2459645a7919STejun Heo	def_bool y
2460e534c7c5SLee Schermerhorn	depends on NUMA
2461e534c7c5SLee Schermerhorn
24629491846fSKirill A. Shutemovconfig ARCH_ENABLE_SPLIT_PMD_PTLOCK
24639491846fSKirill A. Shutemov	def_bool y
24649491846fSKirill A. Shutemov	depends on X86_64 || X86_PAE
24659491846fSKirill A. Shutemov
2466c177c81eSNaoya Horiguchiconfig ARCH_ENABLE_HUGEPAGE_MIGRATION
2467c177c81eSNaoya Horiguchi	def_bool y
2468c177c81eSNaoya Horiguchi	depends on X86_64 && HUGETLB_PAGE && MIGRATION
2469c177c81eSNaoya Horiguchi
24709c670ea3SNaoya Horiguchiconfig ARCH_ENABLE_THP_MIGRATION
24719c670ea3SNaoya Horiguchi	def_bool y
24729c670ea3SNaoya Horiguchi	depends on X86_64 && TRANSPARENT_HUGEPAGE
24739c670ea3SNaoya Horiguchi
2474da85f865SBjorn Helgaasmenu "Power management and ACPI options"
2475e279b6c1SSam Ravnborg
2476e279b6c1SSam Ravnborgconfig ARCH_HIBERNATION_HEADER
24773c2362e6SHarvey Harrison	def_bool y
247844556530SZhimin Gu	depends on HIBERNATION
2479e279b6c1SSam Ravnborg
2480e279b6c1SSam Ravnborgsource "kernel/power/Kconfig"
2481e279b6c1SSam Ravnborg
2482e279b6c1SSam Ravnborgsource "drivers/acpi/Kconfig"
2483e279b6c1SSam Ravnborg
2484efafc8b2SFeng Tangsource "drivers/sfi/Kconfig"
2485efafc8b2SFeng Tang
2486a6b68076SAndi Kleenconfig X86_APM_BOOT
24876fc108a0SJan Beulich	def_bool y
2488282e5aabSPaul Bolle	depends on APM
2489a6b68076SAndi Kleen
2490e279b6c1SSam Ravnborgmenuconfig APM
2491e279b6c1SSam Ravnborg	tristate "APM (Advanced Power Management) BIOS support"
2492efefa6f6SIngo Molnar	depends on X86_32 && PM_SLEEP
2493e279b6c1SSam Ravnborg	---help---
2494e279b6c1SSam Ravnborg	  APM is a BIOS specification for saving power using several different
2495e279b6c1SSam Ravnborg	  techniques. This is mostly useful for battery powered laptops with
2496e279b6c1SSam Ravnborg	  APM compliant BIOSes. If you say Y here, the system time will be
2497e279b6c1SSam Ravnborg	  reset after a RESUME operation, the /proc/apm device will provide
2498e279b6c1SSam Ravnborg	  battery status information, and user-space programs will receive
2499e279b6c1SSam Ravnborg	  notification of APM "events" (e.g. battery status change).
2500e279b6c1SSam Ravnborg
2501e279b6c1SSam Ravnborg	  If you select "Y" here, you can disable actual use of the APM
2502e279b6c1SSam Ravnborg	  BIOS by passing the "apm=off" option to the kernel at boot time.
2503e279b6c1SSam Ravnborg
2504e279b6c1SSam Ravnborg	  Note that the APM support is almost completely disabled for
2505e279b6c1SSam Ravnborg	  machines with more than one CPU.
2506e279b6c1SSam Ravnborg
2507e279b6c1SSam Ravnborg	  In order to use APM, you will need supporting software. For location
2508151f4e2bSMauro Carvalho Chehab	  and more information, read <file:Documentation/power/apm-acpi.rst>
25092dc98fd3SMichael Witten	  and the Battery Powered Linux mini-HOWTO, available from
2510e279b6c1SSam Ravnborg	  <http://www.tldp.org/docs.html#howto>.
2511e279b6c1SSam Ravnborg
2512e279b6c1SSam Ravnborg	  This driver does not spin down disk drives (see the hdparm(8)
2513e279b6c1SSam Ravnborg	  manpage ("man 8 hdparm") for that), and it doesn't turn off
2514e279b6c1SSam Ravnborg	  VESA-compliant "green" monitors.
2515e279b6c1SSam Ravnborg
2516e279b6c1SSam Ravnborg	  This driver does not support the TI 4000M TravelMate and the ACER
2517e279b6c1SSam Ravnborg	  486/DX4/75 because they don't have compliant BIOSes. Many "green"
2518e279b6c1SSam Ravnborg	  desktop machines also don't have compliant BIOSes, and this driver
2519e279b6c1SSam Ravnborg	  may cause those machines to panic during the boot phase.
2520e279b6c1SSam Ravnborg
2521e279b6c1SSam Ravnborg	  Generally, if you don't have a battery in your machine, there isn't
2522e279b6c1SSam Ravnborg	  much point in using this driver and you should say N. If you get
2523e279b6c1SSam Ravnborg	  random kernel OOPSes or reboots that don't seem to be related to
2524e279b6c1SSam Ravnborg	  anything, try disabling/enabling this option (or disabling/enabling
2525e279b6c1SSam Ravnborg	  APM in your BIOS).
2526e279b6c1SSam Ravnborg
2527e279b6c1SSam Ravnborg	  Some other things you should try when experiencing seemingly random,
2528e279b6c1SSam Ravnborg	  "weird" problems:
2529e279b6c1SSam Ravnborg
2530e279b6c1SSam Ravnborg	  1) make sure that you have enough swap space and that it is
2531e279b6c1SSam Ravnborg	  enabled.
2532e279b6c1SSam Ravnborg	  2) pass the "no-hlt" option to the kernel
2533e279b6c1SSam Ravnborg	  3) switch on floating point emulation in the kernel and pass
2534e279b6c1SSam Ravnborg	  the "no387" option to the kernel
2535e279b6c1SSam Ravnborg	  4) pass the "floppy=nodma" option to the kernel
2536e279b6c1SSam Ravnborg	  5) pass the "mem=4M" option to the kernel (thereby disabling
2537e279b6c1SSam Ravnborg	  all but the first 4 MB of RAM)
2538e279b6c1SSam Ravnborg	  6) make sure that the CPU is not over clocked.
2539e279b6c1SSam Ravnborg	  7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/>
2540e279b6c1SSam Ravnborg	  8) disable the cache from your BIOS settings
2541e279b6c1SSam Ravnborg	  9) install a fan for the video card or exchange video RAM
2542e279b6c1SSam Ravnborg	  10) install a better fan for the CPU
2543e279b6c1SSam Ravnborg	  11) exchange RAM chips
2544e279b6c1SSam Ravnborg	  12) exchange the motherboard.
2545e279b6c1SSam Ravnborg
2546e279b6c1SSam Ravnborg	  To compile this driver as a module, choose M here: the
2547e279b6c1SSam Ravnborg	  module will be called apm.
2548e279b6c1SSam Ravnborg
2549e279b6c1SSam Ravnborgif APM
2550e279b6c1SSam Ravnborg
2551e279b6c1SSam Ravnborgconfig APM_IGNORE_USER_SUSPEND
2552e279b6c1SSam Ravnborg	bool "Ignore USER SUSPEND"
25538f9ca475SIngo Molnar	---help---
2554e279b6c1SSam Ravnborg	  This option will ignore USER SUSPEND requests. On machines with a
2555e279b6c1SSam Ravnborg	  compliant APM BIOS, you want to say N. However, on the NEC Versa M
2556e279b6c1SSam Ravnborg	  series notebooks, it is necessary to say Y because of a BIOS bug.
2557e279b6c1SSam Ravnborg
2558e279b6c1SSam Ravnborgconfig APM_DO_ENABLE
2559e279b6c1SSam Ravnborg	bool "Enable PM at boot time"
2560e279b6c1SSam Ravnborg	---help---
2561e279b6c1SSam Ravnborg	  Enable APM features at boot time. From page 36 of the APM BIOS
2562e279b6c1SSam Ravnborg	  specification: "When disabled, the APM BIOS does not automatically
2563e279b6c1SSam Ravnborg	  power manage devices, enter the Standby State, enter the Suspend
2564e279b6c1SSam Ravnborg	  State, or take power saving steps in response to CPU Idle calls."
2565e279b6c1SSam Ravnborg	  This driver will make CPU Idle calls when Linux is idle (unless this
2566e279b6c1SSam Ravnborg	  feature is turned off -- see "Do CPU IDLE calls", below). This
2567e279b6c1SSam Ravnborg	  should always save battery power, but more complicated APM features
2568e279b6c1SSam Ravnborg	  will be dependent on your BIOS implementation. You may need to turn
2569e279b6c1SSam Ravnborg	  this option off if your computer hangs at boot time when using APM
2570e279b6c1SSam Ravnborg	  support, or if it beeps continuously instead of suspending. Turn
2571e279b6c1SSam Ravnborg	  this off if you have a NEC UltraLite Versa 33/C or a Toshiba
2572e279b6c1SSam Ravnborg	  T400CDT. This is off by default since most machines do fine without
2573e279b6c1SSam Ravnborg	  this feature.
2574e279b6c1SSam Ravnborg
2575e279b6c1SSam Ravnborgconfig APM_CPU_IDLE
2576dd8af076SLen Brown	depends on CPU_IDLE
2577e279b6c1SSam Ravnborg	bool "Make CPU Idle calls when idle"
25788f9ca475SIngo Molnar	---help---
2579e279b6c1SSam Ravnborg	  Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop.
2580e279b6c1SSam Ravnborg	  On some machines, this can activate improved power savings, such as
2581e279b6c1SSam Ravnborg	  a slowed CPU clock rate, when the machine is idle. These idle calls
2582e279b6c1SSam Ravnborg	  are made after the idle loop has run for some length of time (e.g.,
2583e279b6c1SSam Ravnborg	  333 mS). On some machines, this will cause a hang at boot time or
2584e279b6c1SSam Ravnborg	  whenever the CPU becomes idle. (On machines with more than one CPU,
2585e279b6c1SSam Ravnborg	  this option does nothing.)
2586e279b6c1SSam Ravnborg
2587e279b6c1SSam Ravnborgconfig APM_DISPLAY_BLANK
2588e279b6c1SSam Ravnborg	bool "Enable console blanking using APM"
25898f9ca475SIngo Molnar	---help---
2590e279b6c1SSam Ravnborg	  Enable console blanking using the APM. Some laptops can use this to
2591e279b6c1SSam Ravnborg	  turn off the LCD backlight when the screen blanker of the Linux
2592e279b6c1SSam Ravnborg	  virtual console blanks the screen. Note that this is only used by
2593e279b6c1SSam Ravnborg	  the virtual console screen blanker, and won't turn off the backlight
2594e279b6c1SSam Ravnborg	  when using the X Window system. This also doesn't have anything to
2595e279b6c1SSam Ravnborg	  do with your VESA-compliant power-saving monitor. Further, this
2596e279b6c1SSam Ravnborg	  option doesn't work for all laptops -- it might not turn off your
2597e279b6c1SSam Ravnborg	  backlight at all, or it might print a lot of errors to the console,
2598e279b6c1SSam Ravnborg	  especially if you are using gpm.
2599e279b6c1SSam Ravnborg
2600e279b6c1SSam Ravnborgconfig APM_ALLOW_INTS
2601e279b6c1SSam Ravnborg	bool "Allow interrupts during APM BIOS calls"
26028f9ca475SIngo Molnar	---help---
2603e279b6c1SSam Ravnborg	  Normally we disable external interrupts while we are making calls to
2604e279b6c1SSam Ravnborg	  the APM BIOS as a measure to lessen the effects of a badly behaving
2605e279b6c1SSam Ravnborg	  BIOS implementation.  The BIOS should reenable interrupts if it
2606e279b6c1SSam Ravnborg	  needs to.  Unfortunately, some BIOSes do not -- especially those in
2607e279b6c1SSam Ravnborg	  many of the newer IBM Thinkpads.  If you experience hangs when you
2608e279b6c1SSam Ravnborg	  suspend, try setting this to Y.  Otherwise, say N.
2609e279b6c1SSam Ravnborg
2610e279b6c1SSam Ravnborgendif # APM
2611e279b6c1SSam Ravnborg
2612bb0a56ecSDave Jonessource "drivers/cpufreq/Kconfig"
2613e279b6c1SSam Ravnborg
2614e279b6c1SSam Ravnborgsource "drivers/cpuidle/Kconfig"
2615e279b6c1SSam Ravnborg
261627471fdbSAndy Henroidsource "drivers/idle/Kconfig"
261727471fdbSAndy Henroid
2618e279b6c1SSam Ravnborgendmenu
2619e279b6c1SSam Ravnborg
2620e279b6c1SSam Ravnborg
2621e279b6c1SSam Ravnborgmenu "Bus options (PCI etc.)"
2622e279b6c1SSam Ravnborg
2623e279b6c1SSam Ravnborgchoice
2624e279b6c1SSam Ravnborg	prompt "PCI access mode"
2625efefa6f6SIngo Molnar	depends on X86_32 && PCI
2626e279b6c1SSam Ravnborg	default PCI_GOANY
2627e279b6c1SSam Ravnborg	---help---
2628e279b6c1SSam Ravnborg	  On PCI systems, the BIOS can be used to detect the PCI devices and
2629e279b6c1SSam Ravnborg	  determine their configuration. However, some old PCI motherboards
2630e279b6c1SSam Ravnborg	  have BIOS bugs and may crash if this is done. Also, some embedded
2631e279b6c1SSam Ravnborg	  PCI-based systems don't have any BIOS at all. Linux can also try to
2632e279b6c1SSam Ravnborg	  detect the PCI hardware directly without using the BIOS.
2633e279b6c1SSam Ravnborg
2634e279b6c1SSam Ravnborg	  With this option, you can specify how Linux should detect the
2635e279b6c1SSam Ravnborg	  PCI devices. If you choose "BIOS", the BIOS will be used,
2636e279b6c1SSam Ravnborg	  if you choose "Direct", the BIOS won't be used, and if you
2637e279b6c1SSam Ravnborg	  choose "MMConfig", then PCI Express MMCONFIG will be used.
2638e279b6c1SSam Ravnborg	  If you choose "Any", the kernel will try MMCONFIG, then the
2639e279b6c1SSam Ravnborg	  direct access method and falls back to the BIOS if that doesn't
2640e279b6c1SSam Ravnborg	  work. If unsure, go with the default, which is "Any".
2641e279b6c1SSam Ravnborg
2642e279b6c1SSam Ravnborgconfig PCI_GOBIOS
2643e279b6c1SSam Ravnborg	bool "BIOS"
2644e279b6c1SSam Ravnborg
2645e279b6c1SSam Ravnborgconfig PCI_GOMMCONFIG
2646e279b6c1SSam Ravnborg	bool "MMConfig"
2647e279b6c1SSam Ravnborg
2648e279b6c1SSam Ravnborgconfig PCI_GODIRECT
2649e279b6c1SSam Ravnborg	bool "Direct"
2650e279b6c1SSam Ravnborg
26513ef0e1f8SAndres Salomonconfig PCI_GOOLPC
265276fb6570SDaniel Drake	bool "OLPC XO-1"
26533ef0e1f8SAndres Salomon	depends on OLPC
26543ef0e1f8SAndres Salomon
26552bdd1b03SAndres Salomonconfig PCI_GOANY
26562bdd1b03SAndres Salomon	bool "Any"
26572bdd1b03SAndres Salomon
2658e279b6c1SSam Ravnborgendchoice
2659e279b6c1SSam Ravnborg
2660e279b6c1SSam Ravnborgconfig PCI_BIOS
26613c2362e6SHarvey Harrison	def_bool y
2662efefa6f6SIngo Molnar	depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY)
2663e279b6c1SSam Ravnborg
2664e279b6c1SSam Ravnborg# x86-64 doesn't support PCI BIOS access from long mode so always go direct.
2665e279b6c1SSam Ravnborgconfig PCI_DIRECT
26663c2362e6SHarvey Harrison	def_bool y
26670aba496fSShaohua Li	depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC || PCI_GOMMCONFIG))
2668e279b6c1SSam Ravnborg
2669e279b6c1SSam Ravnborgconfig PCI_MMCONFIG
2670b45c9f36SJan Kiszka	bool "Support mmconfig PCI config space access" if X86_64
2671b45c9f36SJan Kiszka	default y
26728364e1f8SJan Kiszka	depends on PCI && (ACPI || SFI || JAILHOUSE_GUEST)
2673b45c9f36SJan Kiszka	depends on X86_64 || (PCI_GOANY || PCI_GOMMCONFIG)
2674e279b6c1SSam Ravnborg
26753ef0e1f8SAndres Salomonconfig PCI_OLPC
26762bdd1b03SAndres Salomon	def_bool y
26772bdd1b03SAndres Salomon	depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY)
26783ef0e1f8SAndres Salomon
2679b5401a96SAlex Nixonconfig PCI_XEN
2680b5401a96SAlex Nixon	def_bool y
2681b5401a96SAlex Nixon	depends on PCI && XEN
2682b5401a96SAlex Nixon	select SWIOTLB_XEN
2683b5401a96SAlex Nixon
26848364e1f8SJan Kiszkaconfig MMCONF_FAM10H
26858364e1f8SJan Kiszka	def_bool y
26868364e1f8SJan Kiszka	depends on X86_64 && PCI_MMCONFIG && ACPI
2687e279b6c1SSam Ravnborg
26883f6ea84aSIra W. Snyderconfig PCI_CNB20LE_QUIRK
26896a108a14SDavid Rientjes	bool "Read CNB20LE Host Bridge Windows" if EXPERT
26906ea30386SKees Cook	depends on PCI
26913f6ea84aSIra W. Snyder	help
26923f6ea84aSIra W. Snyder	  Read the PCI windows out of the CNB20LE host bridge. This allows
26933f6ea84aSIra W. Snyder	  PCI hotplug to work on systems with the CNB20LE chipset which do
26943f6ea84aSIra W. Snyder	  not have ACPI.
26953f6ea84aSIra W. Snyder
269664a5fed6SBjorn Helgaas	  There's no public spec for this chipset, and this functionality
269764a5fed6SBjorn Helgaas	  is known to be incomplete.
269864a5fed6SBjorn Helgaas
269964a5fed6SBjorn Helgaas	  You should say N unless you know you need this.
270064a5fed6SBjorn Helgaas
27013a495511SWilliam Breathitt Grayconfig ISA_BUS
270217a2a129SWilliam Breathitt Gray	bool "ISA bus support on modern systems" if EXPERT
27033a495511SWilliam Breathitt Gray	help
270417a2a129SWilliam Breathitt Gray	  Expose ISA bus device drivers and options available for selection and
270517a2a129SWilliam Breathitt Gray	  configuration. Enable this option if your target machine has an ISA
270617a2a129SWilliam Breathitt Gray	  bus. ISA is an older system, displaced by PCI and newer bus
270717a2a129SWilliam Breathitt Gray	  architectures -- if your target machine is modern, it probably does
270817a2a129SWilliam Breathitt Gray	  not have an ISA bus.
27093a495511SWilliam Breathitt Gray
27103a495511SWilliam Breathitt Gray	  If unsure, say N.
27113a495511SWilliam Breathitt Gray
27121c00f016SDavid Rientjes# x86_64 have no ISA slots, but can have ISA-style DMA.
2713e279b6c1SSam Ravnborgconfig ISA_DMA_API
27141c00f016SDavid Rientjes	bool "ISA-style DMA support" if (X86_64 && EXPERT)
27151c00f016SDavid Rientjes	default y
27161c00f016SDavid Rientjes	help
27171c00f016SDavid Rientjes	  Enables ISA-style DMA support for devices requiring such controllers.
27181c00f016SDavid Rientjes	  If unsure, say Y.
2719e279b6c1SSam Ravnborg
272051e68d05SLinus Torvaldsif X86_32
272151e68d05SLinus Torvalds
2722e279b6c1SSam Ravnborgconfig ISA
2723e279b6c1SSam Ravnborg	bool "ISA support"
27248f9ca475SIngo Molnar	---help---
2725e279b6c1SSam Ravnborg	  Find out whether you have ISA slots on your motherboard.  ISA is the
2726e279b6c1SSam Ravnborg	  name of a bus system, i.e. the way the CPU talks to the other stuff
2727e279b6c1SSam Ravnborg	  inside your box.  Other bus systems are PCI, EISA, MicroChannel
2728e279b6c1SSam Ravnborg	  (MCA) or VESA.  ISA is an older system, now being displaced by PCI;
2729e279b6c1SSam Ravnborg	  newer boards don't support it.  If you have ISA, say Y, otherwise N.
2730e279b6c1SSam Ravnborg
2731e279b6c1SSam Ravnborgconfig SCx200
2732e279b6c1SSam Ravnborg	tristate "NatSemi SCx200 support"
27338f9ca475SIngo Molnar	---help---
2734e279b6c1SSam Ravnborg	  This provides basic support for National Semiconductor's
2735e279b6c1SSam Ravnborg	  (now AMD's) Geode processors.  The driver probes for the
2736e279b6c1SSam Ravnborg	  PCI-IDs of several on-chip devices, so its a good dependency
2737e279b6c1SSam Ravnborg	  for other scx200_* drivers.
2738e279b6c1SSam Ravnborg
2739e279b6c1SSam Ravnborg	  If compiled as a module, the driver is named scx200.
2740e279b6c1SSam Ravnborg
2741e279b6c1SSam Ravnborgconfig SCx200HR_TIMER
2742e279b6c1SSam Ravnborg	tristate "NatSemi SCx200 27MHz High-Resolution Timer Support"
2743592913ecSJohn Stultz	depends on SCx200
2744e279b6c1SSam Ravnborg	default y
27458f9ca475SIngo Molnar	---help---
2746e279b6c1SSam Ravnborg	  This driver provides a clocksource built upon the on-chip
2747e279b6c1SSam Ravnborg	  27MHz high-resolution timer.  Its also a workaround for
2748e279b6c1SSam Ravnborg	  NSC Geode SC-1100's buggy TSC, which loses time when the
2749e279b6c1SSam Ravnborg	  processor goes idle (as is done by the scheduler).  The
2750e279b6c1SSam Ravnborg	  other workaround is idle=poll boot option.
2751e279b6c1SSam Ravnborg
27523ef0e1f8SAndres Salomonconfig OLPC
27533ef0e1f8SAndres Salomon	bool "One Laptop Per Child support"
275454008979SThomas Gleixner	depends on !X86_PAE
27553c554946SAndres Salomon	select GPIOLIB
2756dc3119e7SThomas Gleixner	select OF
275745bb1674SDaniel Drake	select OF_PROMTREE
2758b4e51854SGrant Likely	select IRQ_DOMAIN
27590c3d931bSLubomir Rintel	select OLPC_EC
27608f9ca475SIngo Molnar	---help---
27613ef0e1f8SAndres Salomon	  Add support for detecting the unique features of the OLPC
27623ef0e1f8SAndres Salomon	  XO hardware.
27633ef0e1f8SAndres Salomon
2764a3128588SDaniel Drakeconfig OLPC_XO1_PM
2765a3128588SDaniel Drake	bool "OLPC XO-1 Power Management"
2766fa112cf1SBorislav Petkov	depends on OLPC && MFD_CS5535=y && PM_SLEEP
2767bf1ebf00SDaniel Drake	---help---
276897c4cb71SDaniel Drake	  Add support for poweroff and suspend of the OLPC XO-1 laptop.
2769bf1ebf00SDaniel Drake
2770cfee9597SDaniel Drakeconfig OLPC_XO1_RTC
2771cfee9597SDaniel Drake	bool "OLPC XO-1 Real Time Clock"
2772cfee9597SDaniel Drake	depends on OLPC_XO1_PM && RTC_DRV_CMOS
2773cfee9597SDaniel Drake	---help---
2774cfee9597SDaniel Drake	  Add support for the XO-1 real time clock, which can be used as a
2775cfee9597SDaniel Drake	  programmable wakeup source.
2776cfee9597SDaniel Drake
27777feda8e9SDaniel Drakeconfig OLPC_XO1_SCI
27787feda8e9SDaniel Drake	bool "OLPC XO-1 SCI extras"
277992e830f2SArnd Bergmann	depends on OLPC && OLPC_XO1_PM && GPIO_CS5535=y
2780ed8e47feSRandy Dunlap	depends on INPUT=y
2781d8d01a63SDaniel Drake	select POWER_SUPPLY
27827feda8e9SDaniel Drake	---help---
27837feda8e9SDaniel Drake	  Add support for SCI-based features of the OLPC XO-1 laptop:
27847bc74b3dSDaniel Drake	   - EC-driven system wakeups
27857feda8e9SDaniel Drake	   - Power button
27867bc74b3dSDaniel Drake	   - Ebook switch
27872cf2baeaSDaniel Drake	   - Lid switch
2788e1040ac6SDaniel Drake	   - AC adapter status updates
2789e1040ac6SDaniel Drake	   - Battery status updates
27907feda8e9SDaniel Drake
2791a0f30f59SDaniel Drakeconfig OLPC_XO15_SCI
2792a0f30f59SDaniel Drake	bool "OLPC XO-1.5 SCI extras"
2793d8d01a63SDaniel Drake	depends on OLPC && ACPI
2794d8d01a63SDaniel Drake	select POWER_SUPPLY
2795a0f30f59SDaniel Drake	---help---
2796a0f30f59SDaniel Drake	  Add support for SCI-based features of the OLPC XO-1.5 laptop:
2797a0f30f59SDaniel Drake	   - EC-driven system wakeups
2798a0f30f59SDaniel Drake	   - AC adapter status updates
2799a0f30f59SDaniel Drake	   - Battery status updates
2800e279b6c1SSam Ravnborg
2801d4f3e350SEd Wildgooseconfig ALIX
2802d4f3e350SEd Wildgoose	bool "PCEngines ALIX System Support (LED setup)"
2803d4f3e350SEd Wildgoose	select GPIOLIB
2804d4f3e350SEd Wildgoose	---help---
2805d4f3e350SEd Wildgoose	  This option enables system support for the PCEngines ALIX.
2806d4f3e350SEd Wildgoose	  At present this just sets up LEDs for GPIO control on
2807d4f3e350SEd Wildgoose	  ALIX2/3/6 boards.  However, other system specific setup should
2808d4f3e350SEd Wildgoose	  get added here.
2809d4f3e350SEd Wildgoose
2810d4f3e350SEd Wildgoose	  Note: You must still enable the drivers for GPIO and LED support
2811d4f3e350SEd Wildgoose	  (GPIO_CS5535 & LEDS_GPIO) to actually use the LEDs
2812d4f3e350SEd Wildgoose
2813d4f3e350SEd Wildgoose	  Note: You have to set alix.force=1 for boards with Award BIOS.
2814d4f3e350SEd Wildgoose
2815da4e3302SPhilip Prindevilleconfig NET5501
2816da4e3302SPhilip Prindeville	bool "Soekris Engineering net5501 System Support (LEDS, GPIO, etc)"
2817da4e3302SPhilip Prindeville	select GPIOLIB
2818da4e3302SPhilip Prindeville	---help---
2819da4e3302SPhilip Prindeville	  This option enables system support for the Soekris Engineering net5501.
2820da4e3302SPhilip Prindeville
28213197059aSPhilip A. Prindevilleconfig GEOS
28223197059aSPhilip A. Prindeville	bool "Traverse Technologies GEOS System Support (LEDS, GPIO, etc)"
28233197059aSPhilip A. Prindeville	select GPIOLIB
28243197059aSPhilip A. Prindeville	depends on DMI
28253197059aSPhilip A. Prindeville	---help---
28263197059aSPhilip A. Prindeville	  This option enables system support for the Traverse Technologies GEOS.
28273197059aSPhilip A. Prindeville
28287d029125SVivien Didelotconfig TS5500
28297d029125SVivien Didelot	bool "Technologic Systems TS-5500 platform support"
28307d029125SVivien Didelot	depends on MELAN
28317d029125SVivien Didelot	select CHECK_SIGNATURE
28327d029125SVivien Didelot	select NEW_LEDS
28337d029125SVivien Didelot	select LEDS_CLASS
28347d029125SVivien Didelot	---help---
28357d029125SVivien Didelot	  This option enables system support for the Technologic Systems TS-5500.
28367d029125SVivien Didelot
2837e279b6c1SSam Ravnborgendif # X86_32
2838e279b6c1SSam Ravnborg
283923ac4ae8SAndreas Herrmannconfig AMD_NB
2840e279b6c1SSam Ravnborg	def_bool y
28410e152cd7SBorislav Petkov	depends on CPU_SUP_AMD && PCI
2842e279b6c1SSam Ravnborg
2843e3263ab3SDavid Herrmannconfig X86_SYSFB
2844e3263ab3SDavid Herrmann	bool "Mark VGA/VBE/EFI FB as generic system framebuffer"
2845e3263ab3SDavid Herrmann	help
2846e3263ab3SDavid Herrmann	  Firmwares often provide initial graphics framebuffers so the BIOS,
2847e3263ab3SDavid Herrmann	  bootloader or kernel can show basic video-output during boot for
2848e3263ab3SDavid Herrmann	  user-guidance and debugging. Historically, x86 used the VESA BIOS
2849e3263ab3SDavid Herrmann	  Extensions and EFI-framebuffers for this, which are mostly limited
2850e3263ab3SDavid Herrmann	  to x86.
2851e3263ab3SDavid Herrmann	  This option, if enabled, marks VGA/VBE/EFI framebuffers as generic
2852e3263ab3SDavid Herrmann	  framebuffers so the new generic system-framebuffer drivers can be
2853e3263ab3SDavid Herrmann	  used on x86. If the framebuffer is not compatible with the generic
2854e3a5dc08SNikolas Nyby	  modes, it is advertised as fallback platform framebuffer so legacy
2855e3263ab3SDavid Herrmann	  drivers like efifb, vesafb and uvesafb can pick it up.
2856e3263ab3SDavid Herrmann	  If this option is not selected, all system framebuffers are always
2857e3263ab3SDavid Herrmann	  marked as fallback platform framebuffers as usual.
2858e3263ab3SDavid Herrmann
2859e3263ab3SDavid Herrmann	  Note: Legacy fbdev drivers, including vesafb, efifb, uvesafb, will
2860e3263ab3SDavid Herrmann	  not be able to pick up generic system framebuffers if this option
2861e3263ab3SDavid Herrmann	  is selected. You are highly encouraged to enable simplefb as
2862e3263ab3SDavid Herrmann	  replacement if you select this option. simplefb can correctly deal
2863e3263ab3SDavid Herrmann	  with generic system framebuffers. But you should still keep vesafb
2864e3263ab3SDavid Herrmann	  and others enabled as fallback if a system framebuffer is
2865e3263ab3SDavid Herrmann	  incompatible with simplefb.
2866e3263ab3SDavid Herrmann
2867e3263ab3SDavid Herrmann	  If unsure, say Y.
2868e3263ab3SDavid Herrmann
2869e279b6c1SSam Ravnborgendmenu
2870e279b6c1SSam Ravnborg
2871e279b6c1SSam Ravnborg
28721572497cSChristoph Hellwigmenu "Binary Emulations"
2873e279b6c1SSam Ravnborg
2874e279b6c1SSam Ravnborgconfig IA32_EMULATION
2875e279b6c1SSam Ravnborg	bool "IA32 Emulation"
2876e279b6c1SSam Ravnborg	depends on X86_64
287739f88911SIngo Molnar	select ARCH_WANT_OLD_COMPAT_IPC
2878d1603990SRandy Dunlap	select BINFMT_ELF
2879a97f52e6SRoland McGrath	select COMPAT_BINFMT_ELF
288039f88911SIngo Molnar	select COMPAT_OLD_SIGACTION
28818f9ca475SIngo Molnar	---help---
28825fd92e65SH. J. Lu	  Include code to run legacy 32-bit programs under a
28835fd92e65SH. J. Lu	  64-bit kernel. You should likely turn this on, unless you're
28845fd92e65SH. J. Lu	  100% sure that you don't have any 32-bit programs left.
2885e279b6c1SSam Ravnborg
2886e279b6c1SSam Ravnborgconfig IA32_AOUT
2887e279b6c1SSam Ravnborg	tristate "IA32 a.out support"
28886b213e1bSDavid Woodhouse	depends on IA32_EMULATION
2889eac61655SBorislav Petkov	depends on BROKEN
28908f9ca475SIngo Molnar	---help---
2891e279b6c1SSam Ravnborg	  Support old a.out binaries in the 32bit emulation.
2892e279b6c1SSam Ravnborg
28930bf62763SH. Peter Anvinconfig X86_X32
28946ea30386SKees Cook	bool "x32 ABI for 64-bit mode"
28959b54050bSBrian Gerst	depends on X86_64
28965fd92e65SH. J. Lu	---help---
28975fd92e65SH. J. Lu	  Include code to run binaries for the x32 native 32-bit ABI
28985fd92e65SH. J. Lu	  for 64-bit processors.  An x32 process gets access to the
28995fd92e65SH. J. Lu	  full 64-bit register file and wide data path while leaving
29005fd92e65SH. J. Lu	  pointers at 32 bits for smaller memory footprint.
29015fd92e65SH. J. Lu
29025fd92e65SH. J. Lu	  You will need a recent binutils (2.22 or later) with
29035fd92e65SH. J. Lu	  elf32_x86_64 support enabled to compile a kernel with this
29045fd92e65SH. J. Lu	  option set.
29055fd92e65SH. J. Lu
2906953fee1dSIngo Molnarconfig COMPAT_32
2907953fee1dSIngo Molnar	def_bool y
2908953fee1dSIngo Molnar	depends on IA32_EMULATION || X86_32
2909953fee1dSIngo Molnar	select HAVE_UID16
2910953fee1dSIngo Molnar	select OLD_SIGSUSPEND3
2911953fee1dSIngo Molnar
2912e279b6c1SSam Ravnborgconfig COMPAT
29133c2362e6SHarvey Harrison	def_bool y
29140bf62763SH. Peter Anvin	depends on IA32_EMULATION || X86_X32
2915e279b6c1SSam Ravnborg
29163120e25eSJan Beulichif COMPAT
2917e279b6c1SSam Ravnborgconfig COMPAT_FOR_U64_ALIGNMENT
29183120e25eSJan Beulich	def_bool y
2919e279b6c1SSam Ravnborg
2920e279b6c1SSam Ravnborgconfig SYSVIPC_COMPAT
29213c2362e6SHarvey Harrison	def_bool y
29223120e25eSJan Beulich	depends on SYSVIPC
29233120e25eSJan Beulichendif
2924ee009e4aSDavid Howells
2925e279b6c1SSam Ravnborgendmenu
2926e279b6c1SSam Ravnborg
2927e279b6c1SSam Ravnborg
2928e5beae16SKeith Packardconfig HAVE_ATOMIC_IOMAP
2929e5beae16SKeith Packard	def_bool y
2930e5beae16SKeith Packard	depends on X86_32
2931e5beae16SKeith Packard
2932e279b6c1SSam Ravnborgsource "drivers/firmware/Kconfig"
2933e279b6c1SSam Ravnborg
2934edf88417SAvi Kivitysource "arch/x86/kvm/Kconfig"
29355e8ebd84SJason A. Donenfeld
29365e8ebd84SJason A. Donenfeldsource "arch/x86/Kconfig.assembler"
2937