xref: /linux/arch/x86/Kconfig (revision b1a57bbfcc17c87e5cc76695ebb0565380c7501a)
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
63*b1a57bbfSDouglas Anderson	select ARCH_HAS_EARLY_DEBUG		if KGDB
646471b825SIngo Molnar	select ARCH_HAS_ELF_RANDOMIZE
6572d93104SLinus Torvalds	select ARCH_HAS_FAST_MULTIPLIER
66316d097cSDave Hansen	select ARCH_HAS_FILTER_PGPROT
676974f0c4SDaniel Micay	select ARCH_HAS_FORTIFY_SOURCE
68957e3facSRiku Voipio	select ARCH_HAS_GCOV_PROFILE_ALL
695c9a8750SDmitry Vyukov	select ARCH_HAS_KCOV			if X86_64
700c9c1d56SThiago Jung Bauermann	select ARCH_HAS_MEM_ENCRYPT
7110bcc80eSMathieu Desnoyers	select ARCH_HAS_MEMBARRIER_SYNC_CORE
72c763ea26SIngo Molnar	select ARCH_HAS_PMEM_API		if X86_64
7317596731SRobin Murphy	select ARCH_HAS_PTE_DEVMAP		if X86_64
743010a5eaSLaurent Dufour	select ARCH_HAS_PTE_SPECIAL
750aed55afSDan Williams	select ARCH_HAS_UACCESS_FLUSHCACHE	if X86_64
76092b31aaSDan Williams	select ARCH_HAS_UACCESS_MCSAFE		if X86_64 && X86_MCE
77d2852a22SDaniel Borkmann	select ARCH_HAS_SET_MEMORY
78d253ca0cSRick Edgecombe	select ARCH_HAS_SET_DIRECT_MAP
79ad21fc4fSLaura Abbott	select ARCH_HAS_STRICT_KERNEL_RWX
80ad21fc4fSLaura Abbott	select ARCH_HAS_STRICT_MODULE_RWX
81ac1ab12aSMathieu Desnoyers	select ARCH_HAS_SYNC_CORE_BEFORE_USERMODE
8225c619e5SBrian Gerst	select ARCH_HAS_SYSCALL_WRAPPER
83c6d30853SAndrey Ryabinin	select ARCH_HAS_UBSAN_SANITIZE_ALL
846471b825SIngo Molnar	select ARCH_HAVE_NMI_SAFE_CMPXCHG
856471b825SIngo Molnar	select ARCH_MIGHT_HAVE_ACPI_PDC		if ACPI
8677fbbc81SMark Salter	select ARCH_MIGHT_HAVE_PC_PARPORT
875e2c18c0SMark Salter	select ARCH_MIGHT_HAVE_PC_SERIO
883599fe12SThomas Gleixner	select ARCH_STACKWALK
892c870e61SArnd Bergmann	select ARCH_SUPPORTS_ACPI
906471b825SIngo Molnar	select ARCH_SUPPORTS_ATOMIC_RMW
916471b825SIngo Molnar	select ARCH_SUPPORTS_NUMA_BALANCING	if X86_64
926471b825SIngo Molnar	select ARCH_USE_BUILTIN_BSWAP
936471b825SIngo Molnar	select ARCH_USE_QUEUED_RWLOCKS
946471b825SIngo Molnar	select ARCH_USE_QUEUED_SPINLOCKS
95ce4a4e56SAndy Lutomirski	select ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH
9681c22041SDaniel Borkmann	select ARCH_WANT_DEFAULT_BPF_JIT	if X86_64
97c763ea26SIngo Molnar	select ARCH_WANTS_DYNAMIC_TASK_STRUCT
983876d4a3SAlexandre Ghiti	select ARCH_WANT_HUGE_PMD_SHARE
9938d8b4e6SHuang Ying	select ARCH_WANTS_THP_SWAP		if X86_64
10010916706SShile Zhang	select BUILDTIME_TABLE_SORT
1016471b825SIngo Molnar	select CLKEVT_I8253
1026471b825SIngo Molnar	select CLOCKSOURCE_VALIDATE_LAST_CYCLE
1036471b825SIngo Molnar	select CLOCKSOURCE_WATCHDOG
1046471b825SIngo Molnar	select DCACHE_WORD_ACCESS
10545471cd9SLinus Torvalds	select EDAC_ATOMIC_SCRUB
10645471cd9SLinus Torvalds	select EDAC_SUPPORT
1076471b825SIngo Molnar	select GENERIC_CLOCKEVENTS
1086471b825SIngo Molnar	select GENERIC_CLOCKEVENTS_BROADCAST	if X86_64 || (X86_32 && X86_LOCAL_APIC)
1096471b825SIngo Molnar	select GENERIC_CLOCKEVENTS_MIN_ADJUST
1106471b825SIngo Molnar	select GENERIC_CMOS_UPDATE
1116471b825SIngo Molnar	select GENERIC_CPU_AUTOPROBE
11261dc0f55SThomas Gleixner	select GENERIC_CPU_VULNERABILITIES
1136471b825SIngo Molnar	select GENERIC_EARLY_IOREMAP
1146471b825SIngo Molnar	select GENERIC_FIND_FIRST_BIT
1156471b825SIngo Molnar	select GENERIC_IOMAP
116c7d6c9ddSThomas Gleixner	select GENERIC_IRQ_EFFECTIVE_AFF_MASK	if SMP
1170fa115daSThomas Gleixner	select GENERIC_IRQ_MATRIX_ALLOCATOR	if X86_LOCAL_APIC
118ad7a929fSThomas Gleixner	select GENERIC_IRQ_MIGRATION		if SMP
1196471b825SIngo Molnar	select GENERIC_IRQ_PROBE
120c201c917SThomas Gleixner	select GENERIC_IRQ_RESERVATION_MODE
1216471b825SIngo Molnar	select GENERIC_IRQ_SHOW
1226471b825SIngo Molnar	select GENERIC_PENDING_IRQ		if SMP
1232ae27137SSteven Price	select GENERIC_PTDUMP
1246471b825SIngo Molnar	select GENERIC_SMP_IDLE_THREAD
1256471b825SIngo Molnar	select GENERIC_STRNCPY_FROM_USER
1266471b825SIngo Molnar	select GENERIC_STRNLEN_USER
1276471b825SIngo Molnar	select GENERIC_TIME_VSYSCALL
1287ac87074SVincenzo Frascino	select GENERIC_GETTIMEOFDAY
129550a77a7SDmitry Safonov	select GENERIC_VDSO_TIME_NS
13039656e83SChristoph Hellwig	select GUP_GET_PTE_LOW_HIGH		if X86_PAE
13117e5888eSHans de Goede	select HARDIRQS_SW_RESEND
1327edaeb68SThomas Gleixner	select HARDLOCKUP_CHECK_TIMESTAMP	if X86_64
1336471b825SIngo Molnar	select HAVE_ACPI_APEI			if ACPI
1346471b825SIngo Molnar	select HAVE_ACPI_APEI_NMI		if ACPI
1356471b825SIngo Molnar	select HAVE_ALIGNED_STRUCT_PAGE		if SLUB
1366471b825SIngo Molnar	select HAVE_ARCH_AUDITSYSCALL
1376471b825SIngo Molnar	select HAVE_ARCH_HUGE_VMAP		if X86_64 || X86_PAE
1386471b825SIngo Molnar	select HAVE_ARCH_JUMP_LABEL
139b34006c4SArd Biesheuvel	select HAVE_ARCH_JUMP_LABEL_RELATIVE
140d17a1d97SAndrey Ryabinin	select HAVE_ARCH_KASAN			if X86_64
1410609ae01SDaniel Axtens	select HAVE_ARCH_KASAN_VMALLOC		if X86_64
1426471b825SIngo Molnar	select HAVE_ARCH_KGDB
1439e08f57dSDaniel Cashman	select HAVE_ARCH_MMAP_RND_BITS		if MMU
1449e08f57dSDaniel Cashman	select HAVE_ARCH_MMAP_RND_COMPAT_BITS	if MMU && COMPAT
1451b028f78SDmitry Safonov	select HAVE_ARCH_COMPAT_MMAP_BASES	if MMU && COMPAT
146271ca788SArd Biesheuvel	select HAVE_ARCH_PREL32_RELOCATIONS
1476471b825SIngo Molnar	select HAVE_ARCH_SECCOMP_FILTER
148f7d83c1cSKees Cook	select HAVE_ARCH_THREAD_STRUCT_WHITELIST
149afaef01cSAlexander Popov	select HAVE_ARCH_STACKLEAK
1506471b825SIngo Molnar	select HAVE_ARCH_TRACEHOOK
1516471b825SIngo Molnar	select HAVE_ARCH_TRANSPARENT_HUGEPAGE
152a00cc7d9SMatthew Wilcox	select HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD if X86_64
153b64d8d1eSPeter Xu	select HAVE_ARCH_USERFAULTFD_WP         if X86_64 && USERFAULTFD
154e37e43a4SAndy Lutomirski	select HAVE_ARCH_VMAP_STACK		if X86_64
155c763ea26SIngo Molnar	select HAVE_ARCH_WITHIN_STACK_FRAMES
1562ff2b7ecSMasahiro Yamada	select HAVE_ASM_MODVERSIONS
1576471b825SIngo Molnar	select HAVE_CMPXCHG_DOUBLE
1586471b825SIngo Molnar	select HAVE_CMPXCHG_LOCAL
1596471b825SIngo Molnar	select HAVE_CONTEXT_TRACKING		if X86_64
160c1bd55f9SJosh Triplett	select HAVE_COPY_THREAD_TLS
1616471b825SIngo Molnar	select HAVE_C_RECORDMCOUNT
1626471b825SIngo Molnar	select HAVE_DEBUG_KMEMLEAK
1639c5a3621SAkinobu Mita	select HAVE_DMA_CONTIGUOUS
164677aa9f7SSteven Rostedt	select HAVE_DYNAMIC_FTRACE
16506aeaaeaSMasami Hiramatsu	select HAVE_DYNAMIC_FTRACE_WITH_REGS
166562955feSSteven Rostedt (VMware)	select HAVE_DYNAMIC_FTRACE_WITH_DIRECT_CALLS
16703f5781bSWang YanQing	select HAVE_EBPF_JIT
16858340a07SJohannes Berg	select HAVE_EFFICIENT_UNALIGNED_ACCESS
1696630a8e5SChristoph Hellwig	select HAVE_EISA
1705f56a5dfSJiri Slaby	select HAVE_EXIT_THREAD
17167a929e0SChristoph Hellwig	select HAVE_FAST_GUP
172644e0e8dSSteven Rostedt (VMware)	select HAVE_FENTRY			if X86_64 || DYNAMIC_FTRACE
1736471b825SIngo Molnar	select HAVE_FTRACE_MCOUNT_RECORD
1746471b825SIngo Molnar	select HAVE_FUNCTION_GRAPH_TRACER
1756471b825SIngo Molnar	select HAVE_FUNCTION_TRACER
1766b90bd4bSEmese Revfy	select HAVE_GCC_PLUGINS
1770067f129SK.Prasad	select HAVE_HW_BREAKPOINT
1786471b825SIngo Molnar	select HAVE_IDE
1796471b825SIngo Molnar	select HAVE_IOREMAP_PROT
1806471b825SIngo Molnar	select HAVE_IRQ_EXIT_ON_IRQ_STACK	if X86_64
1816471b825SIngo Molnar	select HAVE_IRQ_TIME_ACCOUNTING
1826471b825SIngo Molnar	select HAVE_KERNEL_BZIP2
1836471b825SIngo Molnar	select HAVE_KERNEL_GZIP
1846471b825SIngo Molnar	select HAVE_KERNEL_LZ4
1856471b825SIngo Molnar	select HAVE_KERNEL_LZMA
1866471b825SIngo Molnar	select HAVE_KERNEL_LZO
1876471b825SIngo Molnar	select HAVE_KERNEL_XZ
1886471b825SIngo Molnar	select HAVE_KPROBES
1896471b825SIngo Molnar	select HAVE_KPROBES_ON_FTRACE
190540adea3SMasami Hiramatsu	select HAVE_FUNCTION_ERROR_INJECTION
1916471b825SIngo Molnar	select HAVE_KRETPROBES
1926471b825SIngo Molnar	select HAVE_KVM
1936471b825SIngo Molnar	select HAVE_LIVEPATCH			if X86_64
1946471b825SIngo Molnar	select HAVE_MEMBLOCK_NODE_MAP
1950102752eSFrederic Weisbecker	select HAVE_MIXED_BREAKPOINTS_REGS
196ee9f8fceSJosh Poimboeuf	select HAVE_MOD_ARCH_SPECIFIC
1979f132f7eSJoel Fernandes (Google)	select HAVE_MOVE_PMD
19842a0bb3fSPetr Mladek	select HAVE_NMI
1996471b825SIngo Molnar	select HAVE_OPROFILE
2006471b825SIngo Molnar	select HAVE_OPTPROBES
2016471b825SIngo Molnar	select HAVE_PCSPKR_PLATFORM
2026471b825SIngo Molnar	select HAVE_PERF_EVENTS
203c01d4323SFrederic Weisbecker	select HAVE_PERF_EVENTS_NMI
20492e5aae4SNicholas Piggin	select HAVE_HARDLOCKUP_DETECTOR_PERF	if PERF_EVENTS && HAVE_PERF_EVENTS_NMI
205eb01d42aSChristoph Hellwig	select HAVE_PCI
206c5e63197SJiri Olsa	select HAVE_PERF_REGS
207c5ebcedbSJiri Olsa	select HAVE_PERF_USER_STACK_DUMP
208ff2e6d72SPeter Zijlstra	select MMU_GATHER_RCU_TABLE_FREE		if PARAVIRT
2096471b825SIngo Molnar	select HAVE_REGS_AND_STACK_ACCESS_API
2106415b38bSJiri Slaby	select HAVE_RELIABLE_STACKTRACE		if X86_64 && (UNWINDER_FRAME_POINTER || UNWINDER_ORC) && STACK_VALIDATION
2113c88ee19SMasami Hiramatsu	select HAVE_FUNCTION_ARG_ACCESS_API
212d148eac0SMasahiro Yamada	select HAVE_STACKPROTECTOR		if CC_HAS_SANE_STACKPROTECTOR
213c763ea26SIngo Molnar	select HAVE_STACK_VALIDATION		if X86_64
214d6761b8fSMathieu Desnoyers	select HAVE_RSEQ
2156471b825SIngo Molnar	select HAVE_SYSCALL_TRACEPOINTS
2166471b825SIngo Molnar	select HAVE_UNSTABLE_SCHED_CLOCK
2177c68af6eSAvi Kivity	select HAVE_USER_RETURN_NOTIFIER
2187ac87074SVincenzo Frascino	select HAVE_GENERIC_VDSO
21905736e4aSThomas Gleixner	select HOTPLUG_SMT			if SMP
220c0185808SThomas Gleixner	select IRQ_FORCED_THREADING
22186596f0aSChristoph Hellwig	select NEED_SG_DMA_LENGTH
2222eac9c2dSChristoph Hellwig	select PCI_DOMAINS			if PCI
223625210cfSSinan Kaya	select PCI_LOCKLESS_CONFIG		if PCI
2246471b825SIngo Molnar	select PERF_EVENTS
2253195ef59SPrarit Bhargava	select RTC_LIB
226d6faca40SArnd Bergmann	select RTC_MC146818_LIB
2276471b825SIngo Molnar	select SPARSE_IRQ
22883fe27eaSPranith Kumar	select SRCU
2296471b825SIngo Molnar	select SYSCTL_EXCEPTION_TRACE
23015f4eae7SAndy Lutomirski	select THREAD_INFO_IN_TASK
2316471b825SIngo Molnar	select USER_STACKTRACE_SUPPORT
2326471b825SIngo Molnar	select VIRT_TO_BUS
2336471b825SIngo Molnar	select X86_FEATURE_NAMES		if PROC_FS
2340c608dadSAubrey Li	select PROC_PID_ARCH_STATUS		if PROC_FS
2359e2b4be3SNayna Jain	imply IMA_SECURE_AND_OR_TRUSTED_BOOT    if EFI
2367d8330a5SBalbir Singh
237ba7e4d13SIngo Molnarconfig INSTRUCTION_DECODER
2383120e25eSJan Beulich	def_bool y
2393120e25eSJan Beulich	depends on KPROBES || PERF_EVENTS || UPROBES
240ba7e4d13SIngo Molnar
24151b26adaSLinus Torvaldsconfig OUTPUT_FORMAT
24251b26adaSLinus Torvalds	string
24351b26adaSLinus Torvalds	default "elf32-i386" if X86_32
24451b26adaSLinus Torvalds	default "elf64-x86-64" if X86_64
24551b26adaSLinus Torvalds
2468d5fffb9SSam Ravnborgconfig LOCKDEP_SUPPORT
2473c2362e6SHarvey Harrison	def_bool y
2488d5fffb9SSam Ravnborg
2498d5fffb9SSam Ravnborgconfig STACKTRACE_SUPPORT
2503c2362e6SHarvey Harrison	def_bool y
2518d5fffb9SSam Ravnborg
2528d5fffb9SSam Ravnborgconfig MMU
2533c2362e6SHarvey Harrison	def_bool y
2548d5fffb9SSam Ravnborg
2559e08f57dSDaniel Cashmanconfig ARCH_MMAP_RND_BITS_MIN
2569e08f57dSDaniel Cashman	default 28 if 64BIT
2579e08f57dSDaniel Cashman	default 8
2589e08f57dSDaniel Cashman
2599e08f57dSDaniel Cashmanconfig ARCH_MMAP_RND_BITS_MAX
2609e08f57dSDaniel Cashman	default 32 if 64BIT
2619e08f57dSDaniel Cashman	default 16
2629e08f57dSDaniel Cashman
2639e08f57dSDaniel Cashmanconfig ARCH_MMAP_RND_COMPAT_BITS_MIN
2649e08f57dSDaniel Cashman	default 8
2659e08f57dSDaniel Cashman
2669e08f57dSDaniel Cashmanconfig ARCH_MMAP_RND_COMPAT_BITS_MAX
2679e08f57dSDaniel Cashman	default 16
2689e08f57dSDaniel Cashman
2698d5fffb9SSam Ravnborgconfig SBUS
2708d5fffb9SSam Ravnborg	bool
2718d5fffb9SSam Ravnborg
2728d5fffb9SSam Ravnborgconfig GENERIC_ISA_DMA
2733120e25eSJan Beulich	def_bool y
2743120e25eSJan Beulich	depends on ISA_DMA_API
2758d5fffb9SSam Ravnborg
2768d5fffb9SSam Ravnborgconfig GENERIC_BUG
2773c2362e6SHarvey Harrison	def_bool y
2788d5fffb9SSam Ravnborg	depends on BUG
279b93a531eSJan Beulich	select GENERIC_BUG_RELATIVE_POINTERS if X86_64
280b93a531eSJan Beulich
281b93a531eSJan Beulichconfig GENERIC_BUG_RELATIVE_POINTERS
282b93a531eSJan Beulich	bool
2838d5fffb9SSam Ravnborg
2848d5fffb9SSam Ravnborgconfig ARCH_MAY_HAVE_PC_FDC
2853120e25eSJan Beulich	def_bool y
2863120e25eSJan Beulich	depends on ISA_DMA_API
2878d5fffb9SSam Ravnborg
2881032c0baSSam Ravnborgconfig GENERIC_CALIBRATE_DELAY
2891032c0baSSam Ravnborg	def_bool y
2901032c0baSSam Ravnborg
2919a0b8415Svenkatesh.pallipadi@intel.comconfig ARCH_HAS_CPU_RELAX
2929a0b8415Svenkatesh.pallipadi@intel.com	def_bool y
2938d5fffb9SSam Ravnborg
2941b27d05bSPekka Enbergconfig ARCH_HAS_CACHE_LINE_SIZE
2951b27d05bSPekka Enberg	def_bool y
2961b27d05bSPekka Enberg
297316d097cSDave Hansenconfig ARCH_HAS_FILTER_PGPROT
298316d097cSDave Hansen	def_bool y
299316d097cSDave Hansen
300dd5af90aSMike Travisconfig HAVE_SETUP_PER_CPU_AREA
30189c9c4c5SBrian Gerst	def_bool y
302b32ef636Stravis@sgi.com
30308fc4580STejun Heoconfig NEED_PER_CPU_EMBED_FIRST_CHUNK
30408fc4580STejun Heo	def_bool y
30508fc4580STejun Heo
30608fc4580STejun Heoconfig NEED_PER_CPU_PAGE_FIRST_CHUNK
30711124411STejun Heo	def_bool y
30811124411STejun Heo
309801e4062SJohannes Bergconfig ARCH_HIBERNATION_POSSIBLE
310801e4062SJohannes Berg	def_bool y
311801e4062SJohannes Berg
312f4cb5700SJohannes Bergconfig ARCH_SUSPEND_POSSIBLE
313f4cb5700SJohannes Berg	def_bool y
314f4cb5700SJohannes Berg
31553313b2cSSteve Capperconfig ARCH_WANT_GENERAL_HUGETLB
31653313b2cSSteve Capper	def_bool y
31753313b2cSSteve Capper
3188d5fffb9SSam Ravnborgconfig ZONE_DMA32
319e0fd24a3SJan Beulich	def_bool y if X86_64
3208d5fffb9SSam Ravnborg
3218d5fffb9SSam Ravnborgconfig AUDIT_ARCH
322e0fd24a3SJan Beulich	def_bool y if X86_64
3238d5fffb9SSam Ravnborg
3246a11f75bSAkinobu Mitaconfig ARCH_SUPPORTS_DEBUG_PAGEALLOC
3256a11f75bSAkinobu Mita	def_bool y
3266a11f75bSAkinobu Mita
327d6f2d75aSAndrey Ryabininconfig KASAN_SHADOW_OFFSET
328d6f2d75aSAndrey Ryabinin	hex
329d6f2d75aSAndrey Ryabinin	depends on KASAN
330d6f2d75aSAndrey Ryabinin	default 0xdffffc0000000000
331d6f2d75aSAndrey Ryabinin
33269575d38SShane Wangconfig HAVE_INTEL_TXT
33369575d38SShane Wang	def_bool y
3346ea30386SKees Cook	depends on INTEL_IOMMU && ACPI
33569575d38SShane Wang
3366b0c3d44SSam Ravnborgconfig X86_32_SMP
3376b0c3d44SSam Ravnborg	def_bool y
3386b0c3d44SSam Ravnborg	depends on X86_32 && SMP
3396b0c3d44SSam Ravnborg
3406b0c3d44SSam Ravnborgconfig X86_64_SMP
3416b0c3d44SSam Ravnborg	def_bool y
3426b0c3d44SSam Ravnborg	depends on X86_64 && SMP
3436b0c3d44SSam Ravnborg
344ccbeed3aSTejun Heoconfig X86_32_LAZY_GS
345ccbeed3aSTejun Heo	def_bool y
3468458f8c2SMasahiro Yamada	depends on X86_32 && !STACKPROTECTOR
347ccbeed3aSTejun Heo
3482b144498SSrikar Dronamrajuconfig ARCH_SUPPORTS_UPROBES
3492b144498SSrikar Dronamraju	def_bool y
3502b144498SSrikar Dronamraju
351d20642f0SRob Herringconfig FIX_EARLYCON_MEM
352d20642f0SRob Herring	def_bool y
353d20642f0SRob Herring
35494d49eb3SKirill A. Shutemovconfig DYNAMIC_PHYSICAL_MASK
35594d49eb3SKirill A. Shutemov	bool
35694d49eb3SKirill A. Shutemov
35798233368SKirill A. Shutemovconfig PGTABLE_LEVELS
35898233368SKirill A. Shutemov	int
35977ef56e4SKirill A. Shutemov	default 5 if X86_5LEVEL
36098233368SKirill A. Shutemov	default 4 if X86_64
36198233368SKirill A. Shutemov	default 3 if X86_PAE
36298233368SKirill A. Shutemov	default 2
36398233368SKirill A. Shutemov
3642a61f474SMasahiro Yamadaconfig CC_HAS_SANE_STACKPROTECTOR
3652a61f474SMasahiro Yamada	bool
3662a61f474SMasahiro Yamada	default $(success,$(srctree)/scripts/gcc-x86_64-has-stack-protector.sh $(CC)) if 64BIT
3672a61f474SMasahiro Yamada	default $(success,$(srctree)/scripts/gcc-x86_32-has-stack-protector.sh $(CC))
3682a61f474SMasahiro Yamada	help
3692a61f474SMasahiro Yamada	   We have to make sure stack protector is unconditionally disabled if
3702a61f474SMasahiro Yamada	   the compiler produces broken code.
3712a61f474SMasahiro Yamada
372506f1d07SSam Ravnborgmenu "Processor type and features"
373506f1d07SSam Ravnborg
3745ee71535SRandy Dunlapconfig ZONE_DMA
3755ee71535SRandy Dunlap	bool "DMA memory allocation support" if EXPERT
3765ee71535SRandy Dunlap	default y
3775ee71535SRandy Dunlap	help
3785ee71535SRandy Dunlap	  DMA memory allocation support allows devices with less than 32-bit
3795ee71535SRandy Dunlap	  addressing to allocate within the first 16MB of address space.
3805ee71535SRandy Dunlap	  Disable if no such devices will be used.
3815ee71535SRandy Dunlap
3825ee71535SRandy Dunlap	  If unsure, say Y.
3835ee71535SRandy Dunlap
384506f1d07SSam Ravnborgconfig SMP
385506f1d07SSam Ravnborg	bool "Symmetric multi-processing support"
386506f1d07SSam Ravnborg	---help---
387506f1d07SSam Ravnborg	  This enables support for systems with more than one CPU. If you have
3884a474157SRobert Graffham	  a system with only one CPU, say N. If you have a system with more
3894a474157SRobert Graffham	  than one CPU, say Y.
390506f1d07SSam Ravnborg
3914a474157SRobert Graffham	  If you say N here, the kernel will run on uni- and multiprocessor
392506f1d07SSam Ravnborg	  machines, but will use only one CPU of a multiprocessor machine. If
393506f1d07SSam Ravnborg	  you say Y here, the kernel will run on many, but not all,
3944a474157SRobert Graffham	  uniprocessor machines. On a uniprocessor machine, the kernel
395506f1d07SSam Ravnborg	  will run faster if you say N here.
396506f1d07SSam Ravnborg
397506f1d07SSam Ravnborg	  Note that if you say Y here and choose architecture "586" or
398506f1d07SSam Ravnborg	  "Pentium" under "Processor family", the kernel will not work on 486
399506f1d07SSam Ravnborg	  architectures. Similarly, multiprocessor kernels for the "PPro"
400506f1d07SSam Ravnborg	  architecture may not work on all Pentium based boards.
401506f1d07SSam Ravnborg
402506f1d07SSam Ravnborg	  People using multiprocessor machines who say Y here should also say
403506f1d07SSam Ravnborg	  Y to "Enhanced Real Time Clock Support", below. The "Advanced Power
404506f1d07SSam Ravnborg	  Management" code will be disabled if you say Y here.
405506f1d07SSam Ravnborg
406cb1aaebeSMauro Carvalho Chehab	  See also <file:Documentation/x86/i386/IO-APIC.rst>,
4074f4cfa6cSMauro Carvalho Chehab	  <file:Documentation/admin-guide/lockup-watchdogs.rst> and the SMP-HOWTO available at
408506f1d07SSam Ravnborg	  <http://www.tldp.org/docs.html#howto>.
409506f1d07SSam Ravnborg
410506f1d07SSam Ravnborg	  If you don't know what to do here, say N.
411506f1d07SSam Ravnborg
4129def39beSJosh Triplettconfig X86_FEATURE_NAMES
4139def39beSJosh Triplett	bool "Processor feature human-readable names" if EMBEDDED
4149def39beSJosh Triplett	default y
4159def39beSJosh Triplett	---help---
4169def39beSJosh Triplett	  This option compiles in a table of x86 feature bits and corresponding
4179def39beSJosh Triplett	  names.  This is required to support /proc/cpuinfo and a few kernel
4189def39beSJosh Triplett	  messages.  You can disable this to save space, at the expense of
4199def39beSJosh Triplett	  making those few kernel messages show numeric feature bits instead.
4209def39beSJosh Triplett
4219def39beSJosh Triplett	  If in doubt, say Y.
4229def39beSJosh Triplett
42306cd9a7dSYinghai Luconfig X86_X2APIC
42406cd9a7dSYinghai Lu	bool "Support x2apic"
42519e3d60dSJan Kiszka	depends on X86_LOCAL_APIC && X86_64 && (IRQ_REMAP || HYPERVISOR_GUEST)
42606cd9a7dSYinghai Lu	---help---
42706cd9a7dSYinghai Lu	  This enables x2apic support on CPUs that have this feature.
42806cd9a7dSYinghai Lu
42906cd9a7dSYinghai Lu	  This allows 32-bit apic IDs (so it can support very large systems),
43006cd9a7dSYinghai Lu	  and accesses the local apic via MSRs not via mmio.
43106cd9a7dSYinghai Lu
43206cd9a7dSYinghai Lu	  If you don't know what to do here, say N.
43306cd9a7dSYinghai Lu
4346695c85bSYinghai Luconfig X86_MPPARSE
4356e87f9b7SBin Gao	bool "Enable MPS table" if ACPI || SFI
4367a527688SJan Beulich	default y
4375ab74722SIngo Molnar	depends on X86_LOCAL_APIC
4388f9ca475SIngo Molnar	---help---
4396695c85bSYinghai Lu	  For old smp systems that do not have proper acpi support. Newer systems
4406695c85bSYinghai Lu	  (esp with 64bit cpus) with acpi support, MADT and DSDT will override it
4416695c85bSYinghai Lu
442ddd70cf9SJun Nakajimaconfig GOLDFISH
443ddd70cf9SJun Nakajima	def_bool y
444ddd70cf9SJun Nakajima	depends on X86_GOLDFISH
445ddd70cf9SJun Nakajima
44676b04384SDavid Woodhouseconfig RETPOLINE
44776b04384SDavid Woodhouse	bool "Avoid speculative indirect branches in kernel"
44876b04384SDavid Woodhouse	default y
449d5028ba8SPeter Zijlstra	select STACK_VALIDATION if HAVE_STACK_VALIDATION
45076b04384SDavid Woodhouse	help
45176b04384SDavid Woodhouse	  Compile kernel with the retpoline compiler options to guard against
45276b04384SDavid Woodhouse	  kernel-to-user data leaks by avoiding speculative indirect
45376b04384SDavid Woodhouse	  branches. Requires a compiler with -mindirect-branch=thunk-extern
45476b04384SDavid Woodhouse	  support for full protection. The kernel may run slower.
45576b04384SDavid Woodhouse
456e6d42931SJohannes Weinerconfig X86_CPU_RESCTRL
457e6d42931SJohannes Weiner	bool "x86 CPU resource control support"
4586fe07ce3SBabu Moger	depends on X86 && (CPU_SUP_INTEL || CPU_SUP_AMD)
45959fe5a77SThomas Gleixner	select KERNFS
460e79f15a4SChen Yu	select PROC_CPU_RESCTRL		if PROC_FS
46178e99b4aSFenghua Yu	help
462e6d42931SJohannes Weiner	  Enable x86 CPU resource control support.
4636fe07ce3SBabu Moger
4646fe07ce3SBabu Moger	  Provide support for the allocation and monitoring of system resources
4656fe07ce3SBabu Moger	  usage by the CPU.
4666fe07ce3SBabu Moger
4676fe07ce3SBabu Moger	  Intel calls this Intel Resource Director Technology
4686fe07ce3SBabu Moger	  (Intel(R) RDT). More information about RDT can be found in the
4696fe07ce3SBabu Moger	  Intel x86 Architecture Software Developer Manual.
4706fe07ce3SBabu Moger
4716fe07ce3SBabu Moger	  AMD calls this AMD Platform Quality of Service (AMD QoS).
4726fe07ce3SBabu Moger	  More information about AMD QoS can be found in the AMD64 Technology
4736fe07ce3SBabu Moger	  Platform Quality of Service Extensions manual.
47478e99b4aSFenghua Yu
47578e99b4aSFenghua Yu	  Say N if unsure.
47678e99b4aSFenghua Yu
4778425091fSRavikiran G Thirumalaiif X86_32
478a0d0bb4dSRandy Dunlapconfig X86_BIGSMP
479a0d0bb4dSRandy Dunlap	bool "Support for big SMP systems with more than 8 CPUs"
480a0d0bb4dSRandy Dunlap	depends on SMP
481a0d0bb4dSRandy Dunlap	---help---
482e133f6eaSRandy Dunlap	  This option is needed for the systems that have more than 8 CPUs.
483a0d0bb4dSRandy Dunlap
484c5c606d9SRavikiran G Thirumalaiconfig X86_EXTENDED_PLATFORM
485c5c606d9SRavikiran G Thirumalai	bool "Support for extended (non-PC) x86 platforms"
486c5c606d9SRavikiran G Thirumalai	default y
4878f9ca475SIngo Molnar	---help---
48806ac8346SIngo Molnar	  If you disable this option then the kernel will only support
48906ac8346SIngo Molnar	  standard PC platforms. (which covers the vast majority of
49006ac8346SIngo Molnar	  systems out there.)
49106ac8346SIngo Molnar
4928425091fSRavikiran G Thirumalai	  If you enable this option then you'll be able to select support
4938425091fSRavikiran G Thirumalai	  for the following (non-PC) 32 bit x86 platforms:
494cb7b8023SBen Hutchings		Goldfish (Android emulator)
4958425091fSRavikiran G Thirumalai		AMD Elan
4968425091fSRavikiran G Thirumalai		RDC R-321x SoC
4978425091fSRavikiran G Thirumalai		SGI 320/540 (Visual Workstation)
49883125a3aSAlessandro Rubini		STA2X11-based (e.g. Northville)
4993f4110a4SThomas Gleixner		Moorestown MID devices
50006ac8346SIngo Molnar
50106ac8346SIngo Molnar	  If you have one of these systems, or if you want to build a
50206ac8346SIngo Molnar	  generic distribution kernel, say Y here - otherwise say N.
5038425091fSRavikiran G Thirumalaiendif
50406ac8346SIngo Molnar
5058425091fSRavikiran G Thirumalaiif X86_64
5068425091fSRavikiran G Thirumalaiconfig X86_EXTENDED_PLATFORM
5078425091fSRavikiran G Thirumalai	bool "Support for extended (non-PC) x86 platforms"
5088425091fSRavikiran G Thirumalai	default y
5098425091fSRavikiran G Thirumalai	---help---
5108425091fSRavikiran G Thirumalai	  If you disable this option then the kernel will only support
5118425091fSRavikiran G Thirumalai	  standard PC platforms. (which covers the vast majority of
5128425091fSRavikiran G Thirumalai	  systems out there.)
5138425091fSRavikiran G Thirumalai
5148425091fSRavikiran G Thirumalai	  If you enable this option then you'll be able to select support
5158425091fSRavikiran G Thirumalai	  for the following (non-PC) 64 bit x86 platforms:
51644b111b5SSteffen Persvold		Numascale NumaChip
5178425091fSRavikiran G Thirumalai		ScaleMP vSMP
5188425091fSRavikiran G Thirumalai		SGI Ultraviolet
5198425091fSRavikiran G Thirumalai
5208425091fSRavikiran G Thirumalai	  If you have one of these systems, or if you want to build a
5218425091fSRavikiran G Thirumalai	  generic distribution kernel, say Y here - otherwise say N.
5228425091fSRavikiran G Thirumalaiendif
523c5c606d9SRavikiran G Thirumalai# This is an alphabetically sorted list of 64 bit extended platforms
524c5c606d9SRavikiran G Thirumalai# Please maintain the alphabetic order if and when there are additions
52544b111b5SSteffen Persvoldconfig X86_NUMACHIP
52644b111b5SSteffen Persvold	bool "Numascale NumaChip"
52744b111b5SSteffen Persvold	depends on X86_64
52844b111b5SSteffen Persvold	depends on X86_EXTENDED_PLATFORM
52944b111b5SSteffen Persvold	depends on NUMA
53044b111b5SSteffen Persvold	depends on SMP
53144b111b5SSteffen Persvold	depends on X86_X2APIC
532f9726bfdSDaniel J Blueman	depends on PCI_MMCONFIG
53344b111b5SSteffen Persvold	---help---
53444b111b5SSteffen Persvold	  Adds support for Numascale NumaChip large-SMP systems. Needed to
53544b111b5SSteffen Persvold	  enable more than ~168 cores.
53644b111b5SSteffen Persvold	  If you don't have one of these, you should say N here.
53703b48632SNick Piggin
5386a48565eSIngo Molnarconfig X86_VSMP
539c5c606d9SRavikiran G Thirumalai	bool "ScaleMP vSMP"
5406276a074SBorislav Petkov	select HYPERVISOR_GUEST
5416a48565eSIngo Molnar	select PARAVIRT
5426a48565eSIngo Molnar	depends on X86_64 && PCI
543c5c606d9SRavikiran G Thirumalai	depends on X86_EXTENDED_PLATFORM
544ead91d4bSShai Fultheim	depends on SMP
5458f9ca475SIngo Molnar	---help---
5466a48565eSIngo Molnar	  Support for ScaleMP vSMP systems.  Say 'Y' here if this kernel is
5476a48565eSIngo Molnar	  supposed to run on these EM64T-based machines.  Only choose this option
5486a48565eSIngo Molnar	  if you have one of these machines.
5496a48565eSIngo Molnar
550c5c606d9SRavikiran G Thirumalaiconfig X86_UV
551c5c606d9SRavikiran G Thirumalai	bool "SGI Ultraviolet"
552c5c606d9SRavikiran G Thirumalai	depends on X86_64
553c5c606d9SRavikiran G Thirumalai	depends on X86_EXTENDED_PLATFORM
55454c28d29SJack Steiner	depends on NUMA
5551ecb4ae5SAndrew Morton	depends on EFI
5569d6c26e7SSuresh Siddha	depends on X86_X2APIC
5571222e564SIngo Molnar	depends on PCI
558c5c606d9SRavikiran G Thirumalai	---help---
559c5c606d9SRavikiran G Thirumalai	  This option is needed in order to support SGI Ultraviolet systems.
560c5c606d9SRavikiran G Thirumalai	  If you don't have one of these, you should say N here.
561c5c606d9SRavikiran G Thirumalai
562c5c606d9SRavikiran G Thirumalai# Following is an alphabetically sorted list of 32 bit extended platforms
563c5c606d9SRavikiran G Thirumalai# Please maintain the alphabetic order if and when there are additions
564506f1d07SSam Ravnborg
565ddd70cf9SJun Nakajimaconfig X86_GOLDFISH
566ddd70cf9SJun Nakajima	bool "Goldfish (Virtual Platform)"
567cb7b8023SBen Hutchings	depends on X86_EXTENDED_PLATFORM
568ddd70cf9SJun Nakajima	---help---
569ddd70cf9SJun Nakajima	 Enable support for the Goldfish virtual platform used primarily
570ddd70cf9SJun Nakajima	 for Android development. Unless you are building for the Android
571ddd70cf9SJun Nakajima	 Goldfish emulator say N here.
572ddd70cf9SJun Nakajima
573c751e17bSThomas Gleixnerconfig X86_INTEL_CE
574c751e17bSThomas Gleixner	bool "CE4100 TV platform"
575c751e17bSThomas Gleixner	depends on PCI
576c751e17bSThomas Gleixner	depends on PCI_GODIRECT
5776084a6e2SJiang Liu	depends on X86_IO_APIC
578c751e17bSThomas Gleixner	depends on X86_32
579c751e17bSThomas Gleixner	depends on X86_EXTENDED_PLATFORM
58037bc9f50SDirk Brandewie	select X86_REBOOTFIXUPS
581da6b737bSSebastian Andrzej Siewior	select OF
582da6b737bSSebastian Andrzej Siewior	select OF_EARLY_FLATTREE
583c751e17bSThomas Gleixner	---help---
584c751e17bSThomas Gleixner	  Select for the Intel CE media processor (CE4100) SOC.
585c751e17bSThomas Gleixner	  This option compiles in support for the CE4100 SOC for settop
586c751e17bSThomas Gleixner	  boxes and media devices.
587c751e17bSThomas Gleixner
5884cb9b00fSDavid Cohenconfig X86_INTEL_MID
58943605ef1SAlan Cox	bool "Intel MID platform support"
59043605ef1SAlan Cox	depends on X86_EXTENDED_PLATFORM
591edc6bc78SDavid Cohen	depends on X86_PLATFORM_DEVICES
5921ea7c673SAlan Cox	depends on PCI
5933fda5bb4SAndy Shevchenko	depends on X86_64 || (PCI_GOANY && X86_32)
5941ea7c673SAlan Cox	depends on X86_IO_APIC
5957c9c3a1eSAlan Cox	select SFI
5964cb9b00fSDavid Cohen	select I2C
5977c9c3a1eSAlan Cox	select DW_APB_TIMER
5981ea7c673SAlan Cox	select APB_TIMER
5991ea7c673SAlan Cox	select INTEL_SCU_IPC
60015a713dfSMika Westerberg	select MFD_INTEL_MSIC
6011ea7c673SAlan Cox	---help---
6024cb9b00fSDavid Cohen	  Select to build a kernel capable of supporting Intel MID (Mobile
6034cb9b00fSDavid Cohen	  Internet Device) platform systems which do not have the PCI legacy
6044cb9b00fSDavid Cohen	  interfaces. If you are building for a PC class system say N here.
6051ea7c673SAlan Cox
6064cb9b00fSDavid Cohen	  Intel MID platforms are based on an Intel processor and chipset which
6074cb9b00fSDavid Cohen	  consume less power than most of the x86 derivatives.
60843605ef1SAlan Cox
6098bbc2a13SBryan O'Donoghueconfig X86_INTEL_QUARK
6108bbc2a13SBryan O'Donoghue	bool "Intel Quark platform support"
6118bbc2a13SBryan O'Donoghue	depends on X86_32
6128bbc2a13SBryan O'Donoghue	depends on X86_EXTENDED_PLATFORM
6138bbc2a13SBryan O'Donoghue	depends on X86_PLATFORM_DEVICES
6148bbc2a13SBryan O'Donoghue	depends on X86_TSC
6158bbc2a13SBryan O'Donoghue	depends on PCI
6168bbc2a13SBryan O'Donoghue	depends on PCI_GOANY
6178bbc2a13SBryan O'Donoghue	depends on X86_IO_APIC
6188bbc2a13SBryan O'Donoghue	select IOSF_MBI
6198bbc2a13SBryan O'Donoghue	select INTEL_IMR
6209ab6eb51SAndy Shevchenko	select COMMON_CLK
6218bbc2a13SBryan O'Donoghue	---help---
6228bbc2a13SBryan O'Donoghue	  Select to include support for Quark X1000 SoC.
6238bbc2a13SBryan O'Donoghue	  Say Y here if you have a Quark based system such as the Arduino
6248bbc2a13SBryan O'Donoghue	  compatible Intel Galileo.
6258bbc2a13SBryan O'Donoghue
6263d48aab1SMika Westerbergconfig X86_INTEL_LPSS
6273d48aab1SMika Westerberg	bool "Intel Low Power Subsystem Support"
6285962dd22SSinan Kaya	depends on X86 && ACPI && PCI
6293d48aab1SMika Westerberg	select COMMON_CLK
6300f531431SMathias Nyman	select PINCTRL
631eebb3e8dSAndy Shevchenko	select IOSF_MBI
6323d48aab1SMika Westerberg	---help---
6333d48aab1SMika Westerberg	  Select to build support for Intel Low Power Subsystem such as
6343d48aab1SMika Westerberg	  found on Intel Lynxpoint PCH. Selecting this option enables
6350f531431SMathias Nyman	  things like clock tree (common clock framework) and pincontrol
6360f531431SMathias Nyman	  which are needed by the LPSS peripheral drivers.
6373d48aab1SMika Westerberg
63892082a88SKen Xueconfig X86_AMD_PLATFORM_DEVICE
63992082a88SKen Xue	bool "AMD ACPI2Platform devices support"
64092082a88SKen Xue	depends on ACPI
64192082a88SKen Xue	select COMMON_CLK
64292082a88SKen Xue	select PINCTRL
64392082a88SKen Xue	---help---
64492082a88SKen Xue	  Select to interpret AMD specific ACPI device to platform device
64592082a88SKen Xue	  such as I2C, UART, GPIO found on AMD Carrizo and later chipsets.
64692082a88SKen Xue	  I2C and UART depend on COMMON_CLK to set clock. GPIO driver is
64792082a88SKen Xue	  implemented under PINCTRL subsystem.
64892082a88SKen Xue
649ced3ce76SDavid E. Boxconfig IOSF_MBI
650ced3ce76SDavid E. Box	tristate "Intel SoC IOSF Sideband support for SoC platforms"
651ced3ce76SDavid E. Box	depends on PCI
652ced3ce76SDavid E. Box	---help---
653ced3ce76SDavid E. Box	  This option enables sideband register access support for Intel SoC
654ced3ce76SDavid E. Box	  platforms. On these platforms the IOSF sideband is used in lieu of
655ced3ce76SDavid E. Box	  MSR's for some register accesses, mostly but not limited to thermal
656ced3ce76SDavid E. Box	  and power. Drivers may query the availability of this device to
657ced3ce76SDavid E. Box	  determine if they need the sideband in order to work on these
658ced3ce76SDavid E. Box	  platforms. The sideband is available on the following SoC products.
659ced3ce76SDavid E. Box	  This list is not meant to be exclusive.
660ced3ce76SDavid E. Box	   - BayTrail
661ced3ce76SDavid E. Box	   - Braswell
662ced3ce76SDavid E. Box	   - Quark
663ced3ce76SDavid E. Box
664ced3ce76SDavid E. Box	  You should say Y if you are running a kernel on one of these SoC's.
665ced3ce76SDavid E. Box
666ed2226bdSDavid E. Boxconfig IOSF_MBI_DEBUG
667ed2226bdSDavid E. Box	bool "Enable IOSF sideband access through debugfs"
668ed2226bdSDavid E. Box	depends on IOSF_MBI && DEBUG_FS
669ed2226bdSDavid E. Box	---help---
670ed2226bdSDavid E. Box	  Select this option to expose the IOSF sideband access registers (MCR,
671ed2226bdSDavid E. Box	  MDR, MCRX) through debugfs to write and read register information from
672ed2226bdSDavid E. Box	  different units on the SoC. This is most useful for obtaining device
673ed2226bdSDavid E. Box	  state information for debug and analysis. As this is a general access
674ed2226bdSDavid E. Box	  mechanism, users of this option would have specific knowledge of the
675ed2226bdSDavid E. Box	  device they want to access.
676ed2226bdSDavid E. Box
677ed2226bdSDavid E. Box	  If you don't require the option or are in doubt, say N.
678ed2226bdSDavid E. Box
679c5c606d9SRavikiran G Thirumalaiconfig X86_RDC321X
680c5c606d9SRavikiran G Thirumalai	bool "RDC R-321x SoC"
681506f1d07SSam Ravnborg	depends on X86_32
682c5c606d9SRavikiran G Thirumalai	depends on X86_EXTENDED_PLATFORM
683c5c606d9SRavikiran G Thirumalai	select M486
684c5c606d9SRavikiran G Thirumalai	select X86_REBOOTFIXUPS
685c5c606d9SRavikiran G Thirumalai	---help---
686c5c606d9SRavikiran G Thirumalai	  This option is needed for RDC R-321x system-on-chip, also known
687c5c606d9SRavikiran G Thirumalai	  as R-8610-(G).
688c5c606d9SRavikiran G Thirumalai	  If you don't have one of these chips, you should say N here.
689c5c606d9SRavikiran G Thirumalai
690e0c7ae37SIngo Molnarconfig X86_32_NON_STANDARD
6919c398017SIngo Molnar	bool "Support non-standard 32-bit SMP architectures"
6929c398017SIngo Molnar	depends on X86_32 && SMP
693c5c606d9SRavikiran G Thirumalai	depends on X86_EXTENDED_PLATFORM
6948f9ca475SIngo Molnar	---help---
695b5660ba7SH. Peter Anvin	  This option compiles in the bigsmp and STA2X11 default
696b5660ba7SH. Peter Anvin	  subarchitectures.  It is intended for a generic binary
697b5660ba7SH. Peter Anvin	  kernel. If you select them all, kernel will probe it one by
698b5660ba7SH. Peter Anvin	  one and will fallback to default.
699d49c4288SYinghai Lu
700c5c606d9SRavikiran G Thirumalai# Alphabetically sorted list of Non standard 32 bit platforms
701d49c4288SYinghai Lu
702d949f36fSLinus Torvaldsconfig X86_SUPPORTS_MEMORY_FAILURE
7036fc108a0SJan Beulich	def_bool y
704d949f36fSLinus Torvalds	# MCE code calls memory_failure():
705d949f36fSLinus Torvalds	depends on X86_MCE
706d949f36fSLinus Torvalds	# On 32-bit this adds too big of NODES_SHIFT and we run out of page flags:
707d949f36fSLinus Torvalds	# On 32-bit SPARSEMEM adds too big of SECTIONS_WIDTH:
708d949f36fSLinus Torvalds	depends on X86_64 || !SPARSEMEM
709d949f36fSLinus Torvalds	select ARCH_SUPPORTS_MEMORY_FAILURE
710d949f36fSLinus Torvalds
71183125a3aSAlessandro Rubiniconfig STA2X11
71283125a3aSAlessandro Rubini	bool "STA2X11 Companion Chip Support"
71383125a3aSAlessandro Rubini	depends on X86_32_NON_STANDARD && PCI
71483125a3aSAlessandro Rubini	select SWIOTLB
71583125a3aSAlessandro Rubini	select MFD_STA2X11
7160145071bSLinus Walleij	select GPIOLIB
71783125a3aSAlessandro Rubini	---help---
71883125a3aSAlessandro Rubini	  This adds support for boards based on the STA2X11 IO-Hub,
71983125a3aSAlessandro Rubini	  a.k.a. "ConneXt". The chip is used in place of the standard
72083125a3aSAlessandro Rubini	  PC chipset, so all "standard" peripherals are missing. If this
72183125a3aSAlessandro Rubini	  option is selected the kernel will still be able to boot on
72283125a3aSAlessandro Rubini	  standard PC machines.
72383125a3aSAlessandro Rubini
72482148d1dSShérabconfig X86_32_IRIS
72582148d1dSShérab	tristate "Eurobraille/Iris poweroff module"
72682148d1dSShérab	depends on X86_32
72782148d1dSShérab	---help---
72882148d1dSShérab	  The Iris machines from EuroBraille do not have APM or ACPI support
72982148d1dSShérab	  to shut themselves down properly.  A special I/O sequence is
73082148d1dSShérab	  needed to do so, which is what this module does at
73182148d1dSShérab	  kernel shutdown.
73282148d1dSShérab
73382148d1dSShérab	  This is only for Iris machines from EuroBraille.
73482148d1dSShérab
73582148d1dSShérab	  If unused, say N.
73682148d1dSShérab
737ae1e9130SIngo Molnarconfig SCHED_OMIT_FRAME_POINTER
7383c2362e6SHarvey Harrison	def_bool y
7393c2362e6SHarvey Harrison	prompt "Single-depth WCHAN output"
740a87d0914SKen Chen	depends on X86
7418f9ca475SIngo Molnar	---help---
742506f1d07SSam Ravnborg	  Calculate simpler /proc/<PID>/wchan values. If this option
743506f1d07SSam Ravnborg	  is disabled then wchan values will recurse back to the
744506f1d07SSam Ravnborg	  caller function. This provides more accurate wchan values,
745506f1d07SSam Ravnborg	  at the expense of slightly more scheduling overhead.
746506f1d07SSam Ravnborg
747506f1d07SSam Ravnborg	  If in doubt, say "Y".
748506f1d07SSam Ravnborg
7496276a074SBorislav Petkovmenuconfig HYPERVISOR_GUEST
7506276a074SBorislav Petkov	bool "Linux guest support"
7518f9ca475SIngo Molnar	---help---
7526276a074SBorislav Petkov	  Say Y here to enable options for running Linux under various hyper-
7536276a074SBorislav Petkov	  visors. This option enables basic hypervisor detection and platform
7546276a074SBorislav Petkov	  setup.
755506f1d07SSam Ravnborg
7566276a074SBorislav Petkov	  If you say N, all options in this submenu will be skipped and
7576276a074SBorislav Petkov	  disabled, and Linux guest support won't be built in.
758506f1d07SSam Ravnborg
7596276a074SBorislav Petkovif HYPERVISOR_GUEST
760506f1d07SSam Ravnborg
761e61bd94aSEduardo Pereira Habkostconfig PARAVIRT
762e61bd94aSEduardo Pereira Habkost	bool "Enable paravirtualization code"
7638f9ca475SIngo Molnar	---help---
764e61bd94aSEduardo Pereira Habkost	  This changes the kernel so it can modify itself when it is run
765e61bd94aSEduardo Pereira Habkost	  under a hypervisor, potentially improving performance significantly
766e61bd94aSEduardo Pereira Habkost	  over full virtualization.  However, when run without a hypervisor
767e61bd94aSEduardo Pereira Habkost	  the kernel is theoretically slower and slightly larger.
768e61bd94aSEduardo Pereira Habkost
769c00a280aSJuergen Grossconfig PARAVIRT_XXL
770c00a280aSJuergen Gross	bool
771c00a280aSJuergen Gross
7726276a074SBorislav Petkovconfig PARAVIRT_DEBUG
7736276a074SBorislav Petkov	bool "paravirt-ops debugging"
7746276a074SBorislav Petkov	depends on PARAVIRT && DEBUG_KERNEL
7756276a074SBorislav Petkov	---help---
7766276a074SBorislav Petkov	  Enable to debug paravirt_ops internals.  Specifically, BUG if
7776276a074SBorislav Petkov	  a paravirt_op is missing when it is called.
7786276a074SBorislav Petkov
779b4ecc126SJeremy Fitzhardingeconfig PARAVIRT_SPINLOCKS
780b4ecc126SJeremy Fitzhardinge	bool "Paravirtualization layer for spinlocks"
7816ea30386SKees Cook	depends on PARAVIRT && SMP
782b4ecc126SJeremy Fitzhardinge	---help---
783b4ecc126SJeremy Fitzhardinge	  Paravirtualized spinlocks allow a pvops backend to replace the
784b4ecc126SJeremy Fitzhardinge	  spinlock implementation with something virtualization-friendly
785b4ecc126SJeremy Fitzhardinge	  (for example, block the virtual CPU rather than spinning).
786b4ecc126SJeremy Fitzhardinge
7874c4e4f61SRaghavendra K T	  It has a minimal impact on native kernels and gives a nice performance
7884c4e4f61SRaghavendra K T	  benefit on paravirtualized KVM / Xen kernels.
789b4ecc126SJeremy Fitzhardinge
7904c4e4f61SRaghavendra K T	  If you are unsure how to answer this question, answer Y.
791b4ecc126SJeremy Fitzhardinge
792ecca2502SZhao Yakuiconfig X86_HV_CALLBACK_VECTOR
793ecca2502SZhao Yakui	def_bool n
794ecca2502SZhao Yakui
7956276a074SBorislav Petkovsource "arch/x86/xen/Kconfig"
7966276a074SBorislav Petkov
7976276a074SBorislav Petkovconfig KVM_GUEST
7986276a074SBorislav Petkov	bool "KVM Guest support (including kvmclock)"
7996276a074SBorislav Petkov	depends on PARAVIRT
8006276a074SBorislav Petkov	select PARAVIRT_CLOCK
801a1c4423bSMarcelo Tosatti	select ARCH_CPUIDLE_HALTPOLL
8026276a074SBorislav Petkov	default y
8036276a074SBorislav Petkov	---help---
8046276a074SBorislav Petkov	  This option enables various optimizations for running under the KVM
8056276a074SBorislav Petkov	  hypervisor. It includes a paravirtualized clock, so that instead
8066276a074SBorislav Petkov	  of relying on a PIT (or probably other) emulation by the
8076276a074SBorislav Petkov	  underlying device model, the host provides the guest with
8086276a074SBorislav Petkov	  timing infrastructure such as time of day, and system time
8096276a074SBorislav Petkov
810a1c4423bSMarcelo Tosatticonfig ARCH_CPUIDLE_HALTPOLL
811a1c4423bSMarcelo Tosatti	def_bool n
812a1c4423bSMarcelo Tosatti	prompt "Disable host haltpoll when loading haltpoll driver"
813a1c4423bSMarcelo Tosatti	help
814a1c4423bSMarcelo Tosatti	  If virtualized under KVM, disable host haltpoll.
815a1c4423bSMarcelo Tosatti
8167733607fSMaran Wilsonconfig PVH
8177733607fSMaran Wilson	bool "Support for running PVH guests"
8187733607fSMaran Wilson	---help---
8197733607fSMaran Wilson	  This option enables the PVH entry point for guest virtual machines
8207733607fSMaran Wilson	  as specified in the x86/HVM direct boot ABI.
8217733607fSMaran Wilson
8221e20eb85SSrivatsa Vaddagiriconfig KVM_DEBUG_FS
8231e20eb85SSrivatsa Vaddagiri	bool "Enable debug information for KVM Guests in debugfs"
8241e20eb85SSrivatsa Vaddagiri	depends on KVM_GUEST && DEBUG_FS
8251e20eb85SSrivatsa Vaddagiri	---help---
8261e20eb85SSrivatsa Vaddagiri	  This option enables collection of various statistics for KVM guest.
8271e20eb85SSrivatsa Vaddagiri	  Statistics are displayed in debugfs filesystem. Enabling this option
8281e20eb85SSrivatsa Vaddagiri	  may incur significant overhead.
8291e20eb85SSrivatsa Vaddagiri
8306276a074SBorislav Petkovconfig PARAVIRT_TIME_ACCOUNTING
8316276a074SBorislav Petkov	bool "Paravirtual steal time accounting"
8326276a074SBorislav Petkov	depends on PARAVIRT
8336276a074SBorislav Petkov	---help---
8346276a074SBorislav Petkov	  Select this option to enable fine granularity task steal time
8356276a074SBorislav Petkov	  accounting. Time spent executing other tasks in parallel with
8366276a074SBorislav Petkov	  the current vCPU is discounted from the vCPU power. To account for
8376276a074SBorislav Petkov	  that, there can be a small performance impact.
8386276a074SBorislav Petkov
8396276a074SBorislav Petkov	  If in doubt, say N here.
8406276a074SBorislav Petkov
8417af192c9SGerd Hoffmannconfig PARAVIRT_CLOCK
8427af192c9SGerd Hoffmann	bool
8437af192c9SGerd Hoffmann
8444a362601SJan Kiszkaconfig JAILHOUSE_GUEST
8454a362601SJan Kiszka	bool "Jailhouse non-root cell support"
846abde587bSArnd Bergmann	depends on X86_64 && PCI
84787e65d05SJan Kiszka	select X86_PM_TIMER
8484a362601SJan Kiszka	---help---
8494a362601SJan Kiszka	  This option allows to run Linux as guest in a Jailhouse non-root
8504a362601SJan Kiszka	  cell. You can leave this option disabled if you only want to start
8514a362601SJan Kiszka	  Jailhouse and run Linux afterwards in the root cell.
8524a362601SJan Kiszka
853ec7972c9SZhao Yakuiconfig ACRN_GUEST
854ec7972c9SZhao Yakui	bool "ACRN Guest support"
855ec7972c9SZhao Yakui	depends on X86_64
856498ad393SZhao Yakui	select X86_HV_CALLBACK_VECTOR
857ec7972c9SZhao Yakui	help
858ec7972c9SZhao Yakui	  This option allows to run Linux as guest in the ACRN hypervisor. ACRN is
859ec7972c9SZhao Yakui	  a flexible, lightweight reference open-source hypervisor, built with
860ec7972c9SZhao Yakui	  real-time and safety-criticality in mind. It is built for embedded
861ec7972c9SZhao Yakui	  IOT with small footprint and real-time features. More details can be
862ec7972c9SZhao Yakui	  found in https://projectacrn.org/.
863ec7972c9SZhao Yakui
8646276a074SBorislav Petkovendif #HYPERVISOR_GUEST
86597349135SJeremy Fitzhardinge
866506f1d07SSam Ravnborgsource "arch/x86/Kconfig.cpu"
867506f1d07SSam Ravnborg
868506f1d07SSam Ravnborgconfig HPET_TIMER
8693c2362e6SHarvey Harrison	def_bool X86_64
870506f1d07SSam Ravnborg	prompt "HPET Timer Support" if X86_32
8718f9ca475SIngo Molnar	---help---
872506f1d07SSam Ravnborg	  Use the IA-PC HPET (High Precision Event Timer) to manage
873506f1d07SSam Ravnborg	  time in preference to the PIT and RTC, if a HPET is
874506f1d07SSam Ravnborg	  present.
875506f1d07SSam Ravnborg	  HPET is the next generation timer replacing legacy 8254s.
876506f1d07SSam Ravnborg	  The HPET provides a stable time base on SMP
877506f1d07SSam Ravnborg	  systems, unlike the TSC, but it is more expensive to access,
8784e7f9df2SMichael S. Tsirkin	  as it is off-chip.  The interface used is documented
8794e7f9df2SMichael S. Tsirkin	  in the HPET spec, revision 1.
880506f1d07SSam Ravnborg
881506f1d07SSam Ravnborg	  You can safely choose Y here.  However, HPET will only be
882506f1d07SSam Ravnborg	  activated if the platform and the BIOS support this feature.
883506f1d07SSam Ravnborg	  Otherwise the 8254 will be used for timing services.
884506f1d07SSam Ravnborg
885506f1d07SSam Ravnborg	  Choose N to continue using the legacy 8254 timer.
886506f1d07SSam Ravnborg
887506f1d07SSam Ravnborgconfig HPET_EMULATE_RTC
8883c2362e6SHarvey Harrison	def_bool y
8899d8af78bSBernhard Walle	depends on HPET_TIMER && (RTC=y || RTC=m || RTC_DRV_CMOS=m || RTC_DRV_CMOS=y)
890506f1d07SSam Ravnborg
891bb24c471SJacob Panconfig APB_TIMER
892933b9463SAlan Cox	def_bool y if X86_INTEL_MID
893933b9463SAlan Cox	prompt "Intel MID APB Timer Support" if X86_INTEL_MID
89406c3df49SJamie Iles	select DW_APB_TIMER
895a0c3832aSAlan Cox	depends on X86_INTEL_MID && SFI
896bb24c471SJacob Pan	help
897bb24c471SJacob Pan	 APB timer is the replacement for 8254, HPET on X86 MID platforms.
898bb24c471SJacob Pan	 The APBT provides a stable time base on SMP
899bb24c471SJacob Pan	 systems, unlike the TSC, but it is more expensive to access,
900bb24c471SJacob Pan	 as it is off-chip. APB timers are always running regardless of CPU
901bb24c471SJacob Pan	 C states, they are used as per CPU clockevent device when possible.
902bb24c471SJacob Pan
9036a108a14SDavid Rientjes# Mark as expert because too many people got it wrong.
904506f1d07SSam Ravnborg# The code disables itself when not needed.
9057ae9392cSThomas Petazzoniconfig DMI
9067ae9392cSThomas Petazzoni	default y
907cf074402SArd Biesheuvel	select DMI_SCAN_MACHINE_NON_EFI_FALLBACK
9086a108a14SDavid Rientjes	bool "Enable DMI scanning" if EXPERT
9098f9ca475SIngo Molnar	---help---
9107ae9392cSThomas Petazzoni	  Enabled scanning of DMI to identify machine quirks. Say Y
9117ae9392cSThomas Petazzoni	  here unless you have verified that your setup is not
9127ae9392cSThomas Petazzoni	  affected by entries in the DMI blacklist. Required by PNP
9137ae9392cSThomas Petazzoni	  BIOS code.
9147ae9392cSThomas Petazzoni
915506f1d07SSam Ravnborgconfig GART_IOMMU
91638901f1cSAndi Kleen	bool "Old AMD GART IOMMU support"
917a4ce5a48SChristoph Hellwig	select IOMMU_HELPER
918506f1d07SSam Ravnborg	select SWIOTLB
91923ac4ae8SAndreas Herrmann	depends on X86_64 && PCI && AMD_NB
9208f9ca475SIngo Molnar	---help---
921ced3c42cSIngo Molnar	  Provides a driver for older AMD Athlon64/Opteron/Turion/Sempron
922ced3c42cSIngo Molnar	  GART based hardware IOMMUs.
923ced3c42cSIngo Molnar
924ced3c42cSIngo Molnar	  The GART supports full DMA access for devices with 32-bit access
925ced3c42cSIngo Molnar	  limitations, on systems with more than 3 GB. This is usually needed
926ced3c42cSIngo Molnar	  for USB, sound, many IDE/SATA chipsets and some other devices.
927ced3c42cSIngo Molnar
928ced3c42cSIngo Molnar	  Newer systems typically have a modern AMD IOMMU, supported via
929ced3c42cSIngo Molnar	  the CONFIG_AMD_IOMMU=y config option.
930ced3c42cSIngo Molnar
931ced3c42cSIngo Molnar	  In normal configurations this driver is only active when needed:
932ced3c42cSIngo Molnar	  there's more than 3 GB of memory and the system contains a
933ced3c42cSIngo Molnar	  32-bit limited device.
934ced3c42cSIngo Molnar
935ced3c42cSIngo Molnar	  If unsure, say Y.
936506f1d07SSam Ravnborg
9371184dc2fSMike Travisconfig MAXSMP
938ddb0c5a6SSamuel Thibault	bool "Enable Maximum number of SMP Processors and NUMA Nodes"
9396ea30386SKees Cook	depends on X86_64 && SMP && DEBUG_KERNEL
94036f5101aSMike Travis	select CPUMASK_OFFSTACK
9418f9ca475SIngo Molnar	---help---
942ddb0c5a6SSamuel Thibault	  Enable maximum number of CPUS and NUMA Nodes for this architecture.
9431184dc2fSMike Travis	  If unsure, say N.
944506f1d07SSam Ravnborg
945aec6487eSIngo Molnar#
946aec6487eSIngo Molnar# The maximum number of CPUs supported:
947aec6487eSIngo Molnar#
948aec6487eSIngo Molnar# The main config value is NR_CPUS, which defaults to NR_CPUS_DEFAULT,
949aec6487eSIngo Molnar# and which can be configured interactively in the
950aec6487eSIngo Molnar# [NR_CPUS_RANGE_BEGIN ... NR_CPUS_RANGE_END] range.
951aec6487eSIngo Molnar#
952aec6487eSIngo Molnar# The ranges are different on 32-bit and 64-bit kernels, depending on
953aec6487eSIngo Molnar# hardware capabilities and scalability features of the kernel.
954aec6487eSIngo Molnar#
955aec6487eSIngo Molnar# ( If MAXSMP is enabled we just use the highest possible value and disable
956aec6487eSIngo Molnar#   interactive configuration. )
957aec6487eSIngo Molnar#
958a0d0bb4dSRandy Dunlap
959aec6487eSIngo Molnarconfig NR_CPUS_RANGE_BEGIN
960a0d0bb4dSRandy Dunlap	int
961aec6487eSIngo Molnar	default NR_CPUS_RANGE_END if MAXSMP
962a0d0bb4dSRandy Dunlap	default    1 if !SMP
963a0d0bb4dSRandy Dunlap	default    2
964a0d0bb4dSRandy Dunlap
965aec6487eSIngo Molnarconfig NR_CPUS_RANGE_END
966a0d0bb4dSRandy Dunlap	int
967a0d0bb4dSRandy Dunlap	depends on X86_32
968aec6487eSIngo Molnar	default   64 if  SMP &&  X86_BIGSMP
969aec6487eSIngo Molnar	default    8 if  SMP && !X86_BIGSMP
970a0d0bb4dSRandy Dunlap	default    1 if !SMP
971a0d0bb4dSRandy Dunlap
972aec6487eSIngo Molnarconfig NR_CPUS_RANGE_END
973a0d0bb4dSRandy Dunlap	int
974a0d0bb4dSRandy Dunlap	depends on X86_64
9751edae1aeSScott Wood	default 8192 if  SMP && CPUMASK_OFFSTACK
9761edae1aeSScott Wood	default  512 if  SMP && !CPUMASK_OFFSTACK
977a0d0bb4dSRandy Dunlap	default    1 if !SMP
978aec6487eSIngo Molnar
979aec6487eSIngo Molnarconfig NR_CPUS_DEFAULT
980aec6487eSIngo Molnar	int
981aec6487eSIngo Molnar	depends on X86_32
982aec6487eSIngo Molnar	default   32 if  X86_BIGSMP
983aec6487eSIngo Molnar	default    8 if  SMP
984aec6487eSIngo Molnar	default    1 if !SMP
985aec6487eSIngo Molnar
986aec6487eSIngo Molnarconfig NR_CPUS_DEFAULT
987aec6487eSIngo Molnar	int
988aec6487eSIngo Molnar	depends on X86_64
989a0d0bb4dSRandy Dunlap	default 8192 if  MAXSMP
990a0d0bb4dSRandy Dunlap	default   64 if  SMP
991aec6487eSIngo Molnar	default    1 if !SMP
992a0d0bb4dSRandy Dunlap
993506f1d07SSam Ravnborgconfig NR_CPUS
99436f5101aSMike Travis	int "Maximum number of CPUs" if SMP && !MAXSMP
995aec6487eSIngo Molnar	range NR_CPUS_RANGE_BEGIN NR_CPUS_RANGE_END
996aec6487eSIngo Molnar	default NR_CPUS_DEFAULT
9978f9ca475SIngo Molnar	---help---
998506f1d07SSam Ravnborg	  This allows you to specify the maximum number of CPUs which this
999bb61ccc7SJosh Boyer	  kernel will support.  If CPUMASK_OFFSTACK is enabled, the maximum
1000cad14bb9SKirill A. Shutemov	  supported value is 8192, otherwise the maximum value is 512.  The
1001506f1d07SSam Ravnborg	  minimum value which makes sense is 2.
1002506f1d07SSam Ravnborg
1003aec6487eSIngo Molnar	  This is purely to save memory: each supported CPU adds about 8KB
1004aec6487eSIngo Molnar	  to the kernel image.
1005506f1d07SSam Ravnborg
1006506f1d07SSam Ravnborgconfig SCHED_SMT
1007dbe73364SThomas Gleixner	def_bool y if SMP
1008506f1d07SSam Ravnborg
1009506f1d07SSam Ravnborgconfig SCHED_MC
10103c2362e6SHarvey Harrison	def_bool y
10113c2362e6SHarvey Harrison	prompt "Multi-core scheduler support"
1012c8e56d20SBorislav Petkov	depends on SMP
10138f9ca475SIngo Molnar	---help---
1014506f1d07SSam Ravnborg	  Multi-core scheduler support improves the CPU scheduler's decision
1015506f1d07SSam Ravnborg	  making when dealing with multi-core CPU chips at a cost of slightly
1016506f1d07SSam Ravnborg	  increased overhead in some places. If unsure say N here.
1017506f1d07SSam Ravnborg
1018de966cf4STim Chenconfig SCHED_MC_PRIO
1019de966cf4STim Chen	bool "CPU core priorities scheduler support"
10200a21fc12SIngo Molnar	depends on SCHED_MC && CPU_SUP_INTEL
10210a21fc12SIngo Molnar	select X86_INTEL_PSTATE
10220a21fc12SIngo Molnar	select CPU_FREQ
1023de966cf4STim Chen	default y
10245e76b2abSTim Chen	---help---
1025de966cf4STim Chen	  Intel Turbo Boost Max Technology 3.0 enabled CPUs have a
1026de966cf4STim Chen	  core ordering determined at manufacturing time, which allows
1027de966cf4STim Chen	  certain cores to reach higher turbo frequencies (when running
1028de966cf4STim Chen	  single threaded workloads) than others.
1029de966cf4STim Chen
1030de966cf4STim Chen	  Enabling this kernel feature teaches the scheduler about
1031de966cf4STim Chen	  the TBM3 (aka ITMT) priority order of the CPU cores and adjusts the
1032de966cf4STim Chen	  scheduler's CPU selection logic accordingly, so that higher
1033de966cf4STim Chen	  overall system performance can be achieved.
1034de966cf4STim Chen
1035de966cf4STim Chen	  This feature will have no effect on CPUs without this feature.
1036de966cf4STim Chen
1037de966cf4STim Chen	  If unsure say Y here.
10385e76b2abSTim Chen
103930b8b006SThomas Gleixnerconfig UP_LATE_INIT
104030b8b006SThomas Gleixner	def_bool y
1041ba360f88SThomas Gleixner	depends on !SMP && X86_LOCAL_APIC
104230b8b006SThomas Gleixner
1043506f1d07SSam Ravnborgconfig X86_UP_APIC
104450849eefSJan Beulich	bool "Local APIC support on uniprocessors" if !PCI_MSI
104550849eefSJan Beulich	default PCI_MSI
104638a1dfdaSBryan O'Donoghue	depends on X86_32 && !SMP && !X86_32_NON_STANDARD
10478f9ca475SIngo Molnar	---help---
1048506f1d07SSam Ravnborg	  A local APIC (Advanced Programmable Interrupt Controller) is an
1049506f1d07SSam Ravnborg	  integrated interrupt controller in the CPU. If you have a single-CPU
1050506f1d07SSam Ravnborg	  system which has a processor with a local APIC, you can say Y here to
1051506f1d07SSam Ravnborg	  enable and use it. If you say Y here even though your machine doesn't
1052506f1d07SSam Ravnborg	  have a local APIC, then the kernel will still run with no slowdown at
1053506f1d07SSam Ravnborg	  all. The local APIC supports CPU-generated self-interrupts (timer,
1054506f1d07SSam Ravnborg	  performance counters), and the NMI watchdog which detects hard
1055506f1d07SSam Ravnborg	  lockups.
1056506f1d07SSam Ravnborg
1057506f1d07SSam Ravnborgconfig X86_UP_IOAPIC
1058506f1d07SSam Ravnborg	bool "IO-APIC support on uniprocessors"
1059506f1d07SSam Ravnborg	depends on X86_UP_APIC
10608f9ca475SIngo Molnar	---help---
1061506f1d07SSam Ravnborg	  An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an
1062506f1d07SSam Ravnborg	  SMP-capable replacement for PC-style interrupt controllers. Most
1063506f1d07SSam Ravnborg	  SMP systems and many recent uniprocessor systems have one.
1064506f1d07SSam Ravnborg
1065506f1d07SSam Ravnborg	  If you have a single-CPU system with an IO-APIC, you can say Y here
1066506f1d07SSam Ravnborg	  to use it. If you say Y here even though your machine doesn't have
1067506f1d07SSam Ravnborg	  an IO-APIC, then the kernel will still run with no slowdown at all.
1068506f1d07SSam Ravnborg
1069506f1d07SSam Ravnborgconfig X86_LOCAL_APIC
10703c2362e6SHarvey Harrison	def_bool y
10710dbc6078SThomas Petazzoni	depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC || PCI_MSI
1072b5dc8e6cSJiang Liu	select IRQ_DOMAIN_HIERARCHY
107352f518a3SJiang Liu	select PCI_MSI_IRQ_DOMAIN if PCI_MSI
1074506f1d07SSam Ravnborg
1075506f1d07SSam Ravnborgconfig X86_IO_APIC
1076b1da1e71SJan Beulich	def_bool y
1077b1da1e71SJan Beulich	depends on X86_LOCAL_APIC || X86_UP_IOAPIC
1078506f1d07SSam Ravnborg
107941b9eb26SStefan Assmannconfig X86_REROUTE_FOR_BROKEN_BOOT_IRQS
108041b9eb26SStefan Assmann	bool "Reroute for broken boot IRQs"
108141b9eb26SStefan Assmann	depends on X86_IO_APIC
10828f9ca475SIngo Molnar	---help---
108341b9eb26SStefan Assmann	  This option enables a workaround that fixes a source of
108441b9eb26SStefan Assmann	  spurious interrupts. This is recommended when threaded
108541b9eb26SStefan Assmann	  interrupt handling is used on systems where the generation of
108641b9eb26SStefan Assmann	  superfluous "boot interrupts" cannot be disabled.
108741b9eb26SStefan Assmann
108841b9eb26SStefan Assmann	  Some chipsets generate a legacy INTx "boot IRQ" when the IRQ
108941b9eb26SStefan Assmann	  entry in the chipset's IO-APIC is masked (as, e.g. the RT
109041b9eb26SStefan Assmann	  kernel does during interrupt handling). On chipsets where this
109141b9eb26SStefan Assmann	  boot IRQ generation cannot be disabled, this workaround keeps
109241b9eb26SStefan Assmann	  the original IRQ line masked so that only the equivalent "boot
109341b9eb26SStefan Assmann	  IRQ" is delivered to the CPUs. The workaround also tells the
109441b9eb26SStefan Assmann	  kernel to set up the IRQ handler on the boot IRQ line. In this
109541b9eb26SStefan Assmann	  way only one interrupt is delivered to the kernel. Otherwise
109641b9eb26SStefan Assmann	  the spurious second interrupt may cause the kernel to bring
109741b9eb26SStefan Assmann	  down (vital) interrupt lines.
109841b9eb26SStefan Assmann
109941b9eb26SStefan Assmann	  Only affects "broken" chipsets. Interrupt sharing may be
110041b9eb26SStefan Assmann	  increased on these systems.
110141b9eb26SStefan Assmann
1102506f1d07SSam Ravnborgconfig X86_MCE
1103bab9bc65SAndi Kleen	bool "Machine Check / overheating reporting"
1104648ed940SChen, Gong	select GENERIC_ALLOCATOR
1105e57dbaf7SBorislav Petkov	default y
1106506f1d07SSam Ravnborg	---help---
1107bab9bc65SAndi Kleen	  Machine Check support allows the processor to notify the
1108bab9bc65SAndi Kleen	  kernel if it detects a problem (e.g. overheating, data corruption).
1109506f1d07SSam Ravnborg	  The action the kernel takes depends on the severity of the problem,
1110bab9bc65SAndi Kleen	  ranging from warning messages to halting the machine.
11114efc0670SAndi Kleen
11125de97c9fSTony Luckconfig X86_MCELOG_LEGACY
11135de97c9fSTony Luck	bool "Support for deprecated /dev/mcelog character device"
11145de97c9fSTony Luck	depends on X86_MCE
11155de97c9fSTony Luck	---help---
11165de97c9fSTony Luck	  Enable support for /dev/mcelog which is needed by the old mcelog
11175de97c9fSTony Luck	  userspace logging daemon. Consider switching to the new generation
11185de97c9fSTony Luck	  rasdaemon solution.
11195de97c9fSTony Luck
1120506f1d07SSam Ravnborgconfig X86_MCE_INTEL
11213c2362e6SHarvey Harrison	def_bool y
11223c2362e6SHarvey Harrison	prompt "Intel MCE features"
1123c1ebf835SAndi Kleen	depends on X86_MCE && X86_LOCAL_APIC
11248f9ca475SIngo Molnar	---help---
1125506f1d07SSam Ravnborg	   Additional support for intel specific MCE features such as
1126506f1d07SSam Ravnborg	   the thermal monitor.
1127506f1d07SSam Ravnborg
1128506f1d07SSam Ravnborgconfig X86_MCE_AMD
11293c2362e6SHarvey Harrison	def_bool y
11303c2362e6SHarvey Harrison	prompt "AMD MCE features"
1131f5382de9SYazen Ghannam	depends on X86_MCE && X86_LOCAL_APIC && AMD_NB
11328f9ca475SIngo Molnar	---help---
1133506f1d07SSam Ravnborg	   Additional support for AMD specific MCE features such as
1134506f1d07SSam Ravnborg	   the DRAM Error Threshold.
1135506f1d07SSam Ravnborg
11364efc0670SAndi Kleenconfig X86_ANCIENT_MCE
11376fc108a0SJan Beulich	bool "Support for old Pentium 5 / WinChip machine checks"
1138c31d9633SAndi Kleen	depends on X86_32 && X86_MCE
11394efc0670SAndi Kleen	---help---
11404efc0670SAndi Kleen	  Include support for machine check handling on old Pentium 5 or WinChip
11415065a706SMasanari Iida	  systems. These typically need to be enabled explicitly on the command
11424efc0670SAndi Kleen	  line.
11434efc0670SAndi Kleen
1144b2762686SAndi Kleenconfig X86_MCE_THRESHOLD
1145b2762686SAndi Kleen	depends on X86_MCE_AMD || X86_MCE_INTEL
11466fc108a0SJan Beulich	def_bool y
1147b2762686SAndi Kleen
1148ea149b36SAndi Kleenconfig X86_MCE_INJECT
1149bc8e80d5SBorislav Petkov	depends on X86_MCE && X86_LOCAL_APIC && DEBUG_FS
1150ea149b36SAndi Kleen	tristate "Machine check injector support"
1151ea149b36SAndi Kleen	---help---
1152ea149b36SAndi Kleen	  Provide support for injecting machine checks for testing purposes.
1153ea149b36SAndi Kleen	  If you don't know what a machine check is and you don't do kernel
1154ea149b36SAndi Kleen	  QA it is safe to say n.
1155ea149b36SAndi Kleen
11564efc0670SAndi Kleenconfig X86_THERMAL_VECTOR
11574efc0670SAndi Kleen	def_bool y
11585bb38adcSAndi Kleen	depends on X86_MCE_INTEL
11594efc0670SAndi Kleen
116007dc900eSPeter Zijlstrasource "arch/x86/events/Kconfig"
1161e633c65aSKan Liang
11625aef51c3SAndy Lutomirskiconfig X86_LEGACY_VM86
11631e642812SIngo Molnar	bool "Legacy VM86 support"
1164506f1d07SSam Ravnborg	depends on X86_32
11658f9ca475SIngo Molnar	---help---
11665aef51c3SAndy Lutomirski	  This option allows user programs to put the CPU into V8086
11675aef51c3SAndy Lutomirski	  mode, which is an 80286-era approximation of 16-bit real mode.
11685aef51c3SAndy Lutomirski
11695aef51c3SAndy Lutomirski	  Some very old versions of X and/or vbetool require this option
11705aef51c3SAndy Lutomirski	  for user mode setting.  Similarly, DOSEMU will use it if
11715aef51c3SAndy Lutomirski	  available to accelerate real mode DOS programs.  However, any
11725aef51c3SAndy Lutomirski	  recent version of DOSEMU, X, or vbetool should be fully
11735aef51c3SAndy Lutomirski	  functional even without kernel VM86 support, as they will all
11741e642812SIngo Molnar	  fall back to software emulation. Nevertheless, if you are using
11751e642812SIngo Molnar	  a 16-bit DOS program where 16-bit performance matters, vm86
11761e642812SIngo Molnar	  mode might be faster than emulation and you might want to
11771e642812SIngo Molnar	  enable this option.
11785aef51c3SAndy Lutomirski
11791e642812SIngo Molnar	  Note that any app that works on a 64-bit kernel is unlikely to
11801e642812SIngo Molnar	  need this option, as 64-bit kernels don't, and can't, support
11811e642812SIngo Molnar	  V8086 mode. This option is also unrelated to 16-bit protected
11821e642812SIngo Molnar	  mode and is not needed to run most 16-bit programs under Wine.
11835aef51c3SAndy Lutomirski
11841e642812SIngo Molnar	  Enabling this option increases the complexity of the kernel
11851e642812SIngo Molnar	  and slows down exception handling a tiny bit.
11865aef51c3SAndy Lutomirski
11871e642812SIngo Molnar	  If unsure, say N here.
11885aef51c3SAndy Lutomirski
11895aef51c3SAndy Lutomirskiconfig VM86
11905aef51c3SAndy Lutomirski	bool
11915aef51c3SAndy Lutomirski	default X86_LEGACY_VM86
119234273f41SH. Peter Anvin
119334273f41SH. Peter Anvinconfig X86_16BIT
119434273f41SH. Peter Anvin	bool "Enable support for 16-bit segments" if EXPERT
119534273f41SH. Peter Anvin	default y
1196a5b9e5a2SAndy Lutomirski	depends on MODIFY_LDT_SYSCALL
119734273f41SH. Peter Anvin	---help---
119834273f41SH. Peter Anvin	  This option is required by programs like Wine to run 16-bit
119934273f41SH. Peter Anvin	  protected mode legacy code on x86 processors.  Disabling
120034273f41SH. Peter Anvin	  this option saves about 300 bytes on i386, or around 6K text
120134273f41SH. Peter Anvin	  plus 16K runtime memory on x86-64,
120234273f41SH. Peter Anvin
120334273f41SH. Peter Anvinconfig X86_ESPFIX32
120434273f41SH. Peter Anvin	def_bool y
120534273f41SH. Peter Anvin	depends on X86_16BIT && X86_32
1206506f1d07SSam Ravnborg
1207197725deSH. Peter Anvinconfig X86_ESPFIX64
1208197725deSH. Peter Anvin	def_bool y
120934273f41SH. Peter Anvin	depends on X86_16BIT && X86_64
1210506f1d07SSam Ravnborg
12111ad83c85SAndy Lutomirskiconfig X86_VSYSCALL_EMULATION
12121ad83c85SAndy Lutomirski	bool "Enable vsyscall emulation" if EXPERT
12131ad83c85SAndy Lutomirski	default y
12141ad83c85SAndy Lutomirski	depends on X86_64
12151ad83c85SAndy Lutomirski	---help---
12161ad83c85SAndy Lutomirski	 This enables emulation of the legacy vsyscall page.  Disabling
12171ad83c85SAndy Lutomirski	 it is roughly equivalent to booting with vsyscall=none, except
12181ad83c85SAndy Lutomirski	 that it will also disable the helpful warning if a program
12191ad83c85SAndy Lutomirski	 tries to use a vsyscall.  With this option set to N, offending
12201ad83c85SAndy Lutomirski	 programs will just segfault, citing addresses of the form
12211ad83c85SAndy Lutomirski	 0xffffffffff600?00.
12221ad83c85SAndy Lutomirski
12231ad83c85SAndy Lutomirski	 This option is required by many programs built before 2013, and
12241ad83c85SAndy Lutomirski	 care should be used even with newer programs if set to N.
12251ad83c85SAndy Lutomirski
12261ad83c85SAndy Lutomirski	 Disabling this option saves about 7K of kernel size and
12271ad83c85SAndy Lutomirski	 possibly 4K of additional runtime pagetable memory.
12281ad83c85SAndy Lutomirski
1229111e7b15SThomas Gleixnerconfig X86_IOPL_IOPERM
1230111e7b15SThomas Gleixner	bool "IOPERM and IOPL Emulation"
1231a24ca997SThomas Gleixner	default y
1232c8137aceSThomas Gleixner	---help---
1233111e7b15SThomas Gleixner	  This enables the ioperm() and iopl() syscalls which are necessary
1234111e7b15SThomas Gleixner	  for legacy applications.
1235111e7b15SThomas Gleixner
1236c8137aceSThomas Gleixner	  Legacy IOPL support is an overbroad mechanism which allows user
1237c8137aceSThomas Gleixner	  space aside of accessing all 65536 I/O ports also to disable
1238c8137aceSThomas Gleixner	  interrupts. To gain this access the caller needs CAP_SYS_RAWIO
1239c8137aceSThomas Gleixner	  capabilities and permission from potentially active security
1240c8137aceSThomas Gleixner	  modules.
1241c8137aceSThomas Gleixner
1242c8137aceSThomas Gleixner	  The emulation restricts the functionality of the syscall to
1243c8137aceSThomas Gleixner	  only allowing the full range I/O port access, but prevents the
1244a24ca997SThomas Gleixner	  ability to disable interrupts from user space which would be
1245a24ca997SThomas Gleixner	  granted if the hardware IOPL mechanism would be used.
1246c8137aceSThomas Gleixner
1247506f1d07SSam Ravnborgconfig TOSHIBA
1248506f1d07SSam Ravnborg	tristate "Toshiba Laptop support"
1249506f1d07SSam Ravnborg	depends on X86_32
1250506f1d07SSam Ravnborg	---help---
1251506f1d07SSam Ravnborg	  This adds a driver to safely access the System Management Mode of
1252506f1d07SSam Ravnborg	  the CPU on Toshiba portables with a genuine Toshiba BIOS. It does
1253506f1d07SSam Ravnborg	  not work on models with a Phoenix BIOS. The System Management Mode
1254506f1d07SSam Ravnborg	  is used to set the BIOS and power saving options on Toshiba portables.
1255506f1d07SSam Ravnborg
1256506f1d07SSam Ravnborg	  For information on utilities to make use of this driver see the
1257506f1d07SSam Ravnborg	  Toshiba Linux utilities web site at:
1258506f1d07SSam Ravnborg	  <http://www.buzzard.org.uk/toshiba/>.
1259506f1d07SSam Ravnborg
1260506f1d07SSam Ravnborg	  Say Y if you intend to run this kernel on a Toshiba portable.
1261506f1d07SSam Ravnborg	  Say N otherwise.
1262506f1d07SSam Ravnborg
1263506f1d07SSam Ravnborgconfig I8K
1264039ae585SPali Rohár	tristate "Dell i8k legacy laptop support"
1265949a9d70SJean Delvare	select HWMON
1266039ae585SPali Rohár	select SENSORS_DELL_SMM
1267506f1d07SSam Ravnborg	---help---
1268039ae585SPali Rohár	  This option enables legacy /proc/i8k userspace interface in hwmon
1269039ae585SPali Rohár	  dell-smm-hwmon driver. Character file /proc/i8k reports bios version,
1270039ae585SPali Rohár	  temperature and allows controlling fan speeds of Dell laptops via
1271039ae585SPali Rohár	  System Management Mode. For old Dell laptops (like Dell Inspiron 8000)
1272039ae585SPali Rohár	  it reports also power and hotkey status. For fan speed control is
1273039ae585SPali Rohár	  needed userspace package i8kutils.
1274506f1d07SSam Ravnborg
1275039ae585SPali Rohár	  Say Y if you intend to run this kernel on old Dell laptops or want to
1276039ae585SPali Rohár	  use userspace package i8kutils.
1277506f1d07SSam Ravnborg	  Say N otherwise.
1278506f1d07SSam Ravnborg
1279506f1d07SSam Ravnborgconfig X86_REBOOTFIXUPS
12809ba16087SJan Beulich	bool "Enable X86 board specific fixups for reboot"
12819ba16087SJan Beulich	depends on X86_32
1282506f1d07SSam Ravnborg	---help---
1283506f1d07SSam Ravnborg	  This enables chipset and/or board specific fixups to be done
1284506f1d07SSam Ravnborg	  in order to get reboot to work correctly. This is only needed on
1285506f1d07SSam Ravnborg	  some combinations of hardware and BIOS. The symptom, for which
1286506f1d07SSam Ravnborg	  this config is intended, is when reboot ends with a stalled/hung
1287506f1d07SSam Ravnborg	  system.
1288506f1d07SSam Ravnborg
1289506f1d07SSam Ravnborg	  Currently, the only fixup is for the Geode machines using
12905e3a77e9SFlorian Fainelli	  CS5530A and CS5536 chipsets and the RDC R-321x SoC.
1291506f1d07SSam Ravnborg
1292506f1d07SSam Ravnborg	  Say Y if you want to enable the fixup. Currently, it's safe to
1293506f1d07SSam Ravnborg	  enable this option even if you don't need it.
1294506f1d07SSam Ravnborg	  Say N otherwise.
1295506f1d07SSam Ravnborg
1296506f1d07SSam Ravnborgconfig MICROCODE
12979a2bc335SBorislav Petkov	bool "CPU microcode loading support"
12989a2bc335SBorislav Petkov	default y
129980030e3dSBorislav Petkov	depends on CPU_SUP_AMD || CPU_SUP_INTEL
1300506f1d07SSam Ravnborg	select FW_LOADER
1301506f1d07SSam Ravnborg	---help---
1302506f1d07SSam Ravnborg	  If you say Y here, you will be able to update the microcode on
13035f9c01aaSBorislav Petkov	  Intel and AMD processors. The Intel support is for the IA32 family,
13045f9c01aaSBorislav Petkov	  e.g. Pentium Pro, Pentium II, Pentium III, Pentium 4, Xeon etc. The
13055f9c01aaSBorislav Petkov	  AMD support is for families 0x10 and later. You will obviously need
13065f9c01aaSBorislav Petkov	  the actual microcode binary data itself which is not shipped with
13075f9c01aaSBorislav Petkov	  the Linux kernel.
1308506f1d07SSam Ravnborg
13095f9c01aaSBorislav Petkov	  The preferred method to load microcode from a detached initrd is described
1310cb1aaebeSMauro Carvalho Chehab	  in Documentation/x86/microcode.rst. For that you need to enable
13115f9c01aaSBorislav Petkov	  CONFIG_BLK_DEV_INITRD in order for the loader to be able to scan the
13125f9c01aaSBorislav Petkov	  initrd for microcode blobs.
1313506f1d07SSam Ravnborg
1314c508c46eSBenjamin Gilbert	  In addition, you can build the microcode into the kernel. For that you
1315c508c46eSBenjamin Gilbert	  need to add the vendor-supplied microcode to the CONFIG_EXTRA_FIRMWARE
1316c508c46eSBenjamin Gilbert	  config option.
1317506f1d07SSam Ravnborg
13188d86f390SPeter Orubaconfig MICROCODE_INTEL
1319e43f6e67SBorislav Petkov	bool "Intel microcode loading support"
13208d86f390SPeter Oruba	depends on MICROCODE
13218d86f390SPeter Oruba	default MICROCODE
13228d86f390SPeter Oruba	select FW_LOADER
13238f9ca475SIngo Molnar	---help---
13248d86f390SPeter Oruba	  This options enables microcode patch loading support for Intel
13258d86f390SPeter Oruba	  processors.
13268d86f390SPeter Oruba
1327b8989db9SAlan	  For the current Intel microcode data package go to
1328b8989db9SAlan	  <https://downloadcenter.intel.com> and search for
1329b8989db9SAlan	  'Linux Processor Microcode Data File'.
13308d86f390SPeter Oruba
133180cc9f10SPeter Orubaconfig MICROCODE_AMD
1332e43f6e67SBorislav Petkov	bool "AMD microcode loading support"
133380cc9f10SPeter Oruba	depends on MICROCODE
133480cc9f10SPeter Oruba	select FW_LOADER
13358f9ca475SIngo Molnar	---help---
133680cc9f10SPeter Oruba	  If you select this option, microcode patch loading support for AMD
133780cc9f10SPeter Oruba	  processors will be enabled.
133880cc9f10SPeter Oruba
1339506f1d07SSam Ravnborgconfig MICROCODE_OLD_INTERFACE
1340c02f48e0SBorislav Petkov	bool "Ancient loading interface (DEPRECATED)"
1341c02f48e0SBorislav Petkov	default n
1342506f1d07SSam Ravnborg	depends on MICROCODE
1343c02f48e0SBorislav Petkov	---help---
1344c02f48e0SBorislav Petkov	  DO NOT USE THIS! This is the ancient /dev/cpu/microcode interface
1345c02f48e0SBorislav Petkov	  which was used by userspace tools like iucode_tool and microcode.ctl.
1346c02f48e0SBorislav Petkov	  It is inadequate because it runs too late to be able to properly
1347c02f48e0SBorislav Petkov	  load microcode on a machine and it needs special tools. Instead, you
1348c02f48e0SBorislav Petkov	  should've switched to the early loading method with the initrd or
1349cb1aaebeSMauro Carvalho Chehab	  builtin microcode by now: Documentation/x86/microcode.rst
1350506f1d07SSam Ravnborg
1351506f1d07SSam Ravnborgconfig X86_MSR
1352506f1d07SSam Ravnborg	tristate "/dev/cpu/*/msr - Model-specific register support"
13538f9ca475SIngo Molnar	---help---
1354506f1d07SSam Ravnborg	  This device gives privileged processes access to the x86
1355506f1d07SSam Ravnborg	  Model-Specific Registers (MSRs).  It is a character device with
1356506f1d07SSam Ravnborg	  major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr.
1357506f1d07SSam Ravnborg	  MSR accesses are directed to a specific CPU on multi-processor
1358506f1d07SSam Ravnborg	  systems.
1359506f1d07SSam Ravnborg
1360506f1d07SSam Ravnborgconfig X86_CPUID
1361506f1d07SSam Ravnborg	tristate "/dev/cpu/*/cpuid - CPU information support"
13628f9ca475SIngo Molnar	---help---
1363506f1d07SSam Ravnborg	  This device gives processes access to the x86 CPUID instruction to
1364506f1d07SSam Ravnborg	  be executed on a specific processor.  It is a character device
1365506f1d07SSam Ravnborg	  with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to
1366506f1d07SSam Ravnborg	  /dev/cpu/31/cpuid.
1367506f1d07SSam Ravnborg
1368506f1d07SSam Ravnborgchoice
1369506f1d07SSam Ravnborg	prompt "High Memory Support"
13706fc108a0SJan Beulich	default HIGHMEM4G
1371506f1d07SSam Ravnborg	depends on X86_32
1372506f1d07SSam Ravnborg
1373506f1d07SSam Ravnborgconfig NOHIGHMEM
1374506f1d07SSam Ravnborg	bool "off"
1375506f1d07SSam Ravnborg	---help---
1376506f1d07SSam Ravnborg	  Linux can use up to 64 Gigabytes of physical memory on x86 systems.
1377506f1d07SSam Ravnborg	  However, the address space of 32-bit x86 processors is only 4
1378506f1d07SSam Ravnborg	  Gigabytes large. That means that, if you have a large amount of
1379506f1d07SSam Ravnborg	  physical memory, not all of it can be "permanently mapped" by the
1380506f1d07SSam Ravnborg	  kernel. The physical memory that's not permanently mapped is called
1381506f1d07SSam Ravnborg	  "high memory".
1382506f1d07SSam Ravnborg
1383506f1d07SSam Ravnborg	  If you are compiling a kernel which will never run on a machine with
1384506f1d07SSam Ravnborg	  more than 1 Gigabyte total physical RAM, answer "off" here (default
1385506f1d07SSam Ravnborg	  choice and suitable for most users). This will result in a "3GB/1GB"
1386506f1d07SSam Ravnborg	  split: 3GB are mapped so that each process sees a 3GB virtual memory
1387506f1d07SSam Ravnborg	  space and the remaining part of the 4GB virtual memory space is used
1388506f1d07SSam Ravnborg	  by the kernel to permanently map as much physical memory as
1389506f1d07SSam Ravnborg	  possible.
1390506f1d07SSam Ravnborg
1391506f1d07SSam Ravnborg	  If the machine has between 1 and 4 Gigabytes physical RAM, then
1392506f1d07SSam Ravnborg	  answer "4GB" here.
1393506f1d07SSam Ravnborg
1394506f1d07SSam Ravnborg	  If more than 4 Gigabytes is used then answer "64GB" here. This
1395506f1d07SSam Ravnborg	  selection turns Intel PAE (Physical Address Extension) mode on.
1396506f1d07SSam Ravnborg	  PAE implements 3-level paging on IA32 processors. PAE is fully
1397506f1d07SSam Ravnborg	  supported by Linux, PAE mode is implemented on all recent Intel
1398506f1d07SSam Ravnborg	  processors (Pentium Pro and better). NOTE: If you say "64GB" here,
1399506f1d07SSam Ravnborg	  then the kernel will not boot on CPUs that don't support PAE!
1400506f1d07SSam Ravnborg
1401506f1d07SSam Ravnborg	  The actual amount of total physical memory will either be
1402506f1d07SSam Ravnborg	  auto detected or can be forced by using a kernel command line option
1403506f1d07SSam Ravnborg	  such as "mem=256M". (Try "man bootparam" or see the documentation of
1404506f1d07SSam Ravnborg	  your boot loader (lilo or loadlin) about how to pass options to the
1405506f1d07SSam Ravnborg	  kernel at boot time.)
1406506f1d07SSam Ravnborg
1407506f1d07SSam Ravnborg	  If unsure, say "off".
1408506f1d07SSam Ravnborg
1409506f1d07SSam Ravnborgconfig HIGHMEM4G
1410506f1d07SSam Ravnborg	bool "4GB"
14118f9ca475SIngo Molnar	---help---
1412506f1d07SSam Ravnborg	  Select this if you have a 32-bit processor and between 1 and 4
1413506f1d07SSam Ravnborg	  gigabytes of physical RAM.
1414506f1d07SSam Ravnborg
1415506f1d07SSam Ravnborgconfig HIGHMEM64G
1416506f1d07SSam Ravnborg	bool "64GB"
141769b8d3fcSMatthew Whitehead	depends on !M486 && !M586 && !M586TSC && !M586MMX && !MGEODE_LX && !MGEODEGX1 && !MCYRIXIII && !MELAN && !MWINCHIPC6 && !WINCHIP3D && !MK6
1418506f1d07SSam Ravnborg	select X86_PAE
14198f9ca475SIngo Molnar	---help---
1420506f1d07SSam Ravnborg	  Select this if you have a 32-bit processor and more than 4
1421506f1d07SSam Ravnborg	  gigabytes of physical RAM.
1422506f1d07SSam Ravnborg
1423506f1d07SSam Ravnborgendchoice
1424506f1d07SSam Ravnborg
1425506f1d07SSam Ravnborgchoice
14266a108a14SDavid Rientjes	prompt "Memory split" if EXPERT
1427506f1d07SSam Ravnborg	default VMSPLIT_3G
1428506f1d07SSam Ravnborg	depends on X86_32
14298f9ca475SIngo Molnar	---help---
1430506f1d07SSam Ravnborg	  Select the desired split between kernel and user memory.
1431506f1d07SSam Ravnborg
1432506f1d07SSam Ravnborg	  If the address range available to the kernel is less than the
1433506f1d07SSam Ravnborg	  physical memory installed, the remaining memory will be available
1434506f1d07SSam Ravnborg	  as "high memory". Accessing high memory is a little more costly
1435506f1d07SSam Ravnborg	  than low memory, as it needs to be mapped into the kernel first.
1436506f1d07SSam Ravnborg	  Note that increasing the kernel address space limits the range
1437506f1d07SSam Ravnborg	  available to user programs, making the address space there
1438506f1d07SSam Ravnborg	  tighter.  Selecting anything other than the default 3G/1G split
1439506f1d07SSam Ravnborg	  will also likely make your kernel incompatible with binary-only
1440506f1d07SSam Ravnborg	  kernel modules.
1441506f1d07SSam Ravnborg
1442506f1d07SSam Ravnborg	  If you are not absolutely sure what you are doing, leave this
1443506f1d07SSam Ravnborg	  option alone!
1444506f1d07SSam Ravnborg
1445506f1d07SSam Ravnborg	config VMSPLIT_3G
1446506f1d07SSam Ravnborg		bool "3G/1G user/kernel split"
1447506f1d07SSam Ravnborg	config VMSPLIT_3G_OPT
1448506f1d07SSam Ravnborg		depends on !X86_PAE
1449506f1d07SSam Ravnborg		bool "3G/1G user/kernel split (for full 1G low memory)"
1450506f1d07SSam Ravnborg	config VMSPLIT_2G
1451506f1d07SSam Ravnborg		bool "2G/2G user/kernel split"
1452506f1d07SSam Ravnborg	config VMSPLIT_2G_OPT
1453506f1d07SSam Ravnborg		depends on !X86_PAE
1454506f1d07SSam Ravnborg		bool "2G/2G user/kernel split (for full 2G low memory)"
1455506f1d07SSam Ravnborg	config VMSPLIT_1G
1456506f1d07SSam Ravnborg		bool "1G/3G user/kernel split"
1457506f1d07SSam Ravnborgendchoice
1458506f1d07SSam Ravnborg
1459506f1d07SSam Ravnborgconfig PAGE_OFFSET
1460506f1d07SSam Ravnborg	hex
1461506f1d07SSam Ravnborg	default 0xB0000000 if VMSPLIT_3G_OPT
1462506f1d07SSam Ravnborg	default 0x80000000 if VMSPLIT_2G
1463506f1d07SSam Ravnborg	default 0x78000000 if VMSPLIT_2G_OPT
1464506f1d07SSam Ravnborg	default 0x40000000 if VMSPLIT_1G
1465506f1d07SSam Ravnborg	default 0xC0000000
1466506f1d07SSam Ravnborg	depends on X86_32
1467506f1d07SSam Ravnborg
1468506f1d07SSam Ravnborgconfig HIGHMEM
14693c2362e6SHarvey Harrison	def_bool y
1470506f1d07SSam Ravnborg	depends on X86_32 && (HIGHMEM64G || HIGHMEM4G)
1471506f1d07SSam Ravnborg
1472506f1d07SSam Ravnborgconfig X86_PAE
14739ba16087SJan Beulich	bool "PAE (Physical Address Extension) Support"
1474506f1d07SSam Ravnborg	depends on X86_32 && !HIGHMEM4G
1475d4a451d5SChristoph Hellwig	select PHYS_ADDR_T_64BIT
14769d99c712SChristian Melki	select SWIOTLB
14778f9ca475SIngo Molnar	---help---
1478506f1d07SSam Ravnborg	  PAE is required for NX support, and furthermore enables
1479506f1d07SSam Ravnborg	  larger swapspace support for non-overcommit purposes. It
1480506f1d07SSam Ravnborg	  has the cost of more pagetable lookup overhead, and also
1481506f1d07SSam Ravnborg	  consumes more pagetable space per process.
1482506f1d07SSam Ravnborg
148377ef56e4SKirill A. Shutemovconfig X86_5LEVEL
148477ef56e4SKirill A. Shutemov	bool "Enable 5-level page tables support"
148518ec1eafSKirill A. Shutemov	default y
1486eedb92abSKirill A. Shutemov	select DYNAMIC_MEMORY_LAYOUT
1487162434e7SKirill A. Shutemov	select SPARSEMEM_VMEMMAP
148877ef56e4SKirill A. Shutemov	depends on X86_64
148977ef56e4SKirill A. Shutemov	---help---
149077ef56e4SKirill A. Shutemov	  5-level paging enables access to larger address space:
149177ef56e4SKirill A. Shutemov	  upto 128 PiB of virtual address space and 4 PiB of
149277ef56e4SKirill A. Shutemov	  physical address space.
149377ef56e4SKirill A. Shutemov
149477ef56e4SKirill A. Shutemov	  It will be supported by future Intel CPUs.
149577ef56e4SKirill A. Shutemov
14966657fca0SKirill A. Shutemov	  A kernel with the option enabled can be booted on machines that
14976657fca0SKirill A. Shutemov	  support 4- or 5-level paging.
149877ef56e4SKirill A. Shutemov
1499cb1aaebeSMauro Carvalho Chehab	  See Documentation/x86/x86_64/5level-paging.rst for more
150077ef56e4SKirill A. Shutemov	  information.
150177ef56e4SKirill A. Shutemov
150277ef56e4SKirill A. Shutemov	  Say N if unsure.
150377ef56e4SKirill A. Shutemov
150410971ab2SIngo Molnarconfig X86_DIRECT_GBPAGES
1505e5008abeSLuis R. Rodriguez	def_bool y
15062e1da13fSVlastimil Babka	depends on X86_64
15078f9ca475SIngo Molnar	---help---
150810971ab2SIngo Molnar	  Certain kernel features effectively disable kernel
150910971ab2SIngo Molnar	  linear 1 GB mappings (even if the CPU otherwise
151010971ab2SIngo Molnar	  supports them), so don't confuse the user by printing
151110971ab2SIngo Molnar	  that we have them enabled.
15129e899816SNick Piggin
15135c280cf6SThomas Gleixnerconfig X86_CPA_STATISTICS
15145c280cf6SThomas Gleixner	bool "Enable statistic for Change Page Attribute"
15155c280cf6SThomas Gleixner	depends on DEBUG_FS
15165c280cf6SThomas Gleixner	---help---
1517b75baaf3SIngo Molnar	  Expose statistics about the Change Page Attribute mechanism, which
1518a943245aSColin Ian King	  helps to determine the effectiveness of preserving large and huge
15195c280cf6SThomas Gleixner	  page mappings when mapping protections are changed.
15205c280cf6SThomas Gleixner
15217744ccdbSTom Lendackyconfig AMD_MEM_ENCRYPT
15227744ccdbSTom Lendacky	bool "AMD Secure Memory Encryption (SME) support"
15237744ccdbSTom Lendacky	depends on X86_64 && CPU_SUP_AMD
152494d49eb3SKirill A. Shutemov	select DYNAMIC_PHYSICAL_MASK
1525ce9084baSArd Biesheuvel	select ARCH_USE_MEMREMAP_PROT
15269087c375STom Lendacky	select ARCH_HAS_FORCE_DMA_UNENCRYPTED
15277744ccdbSTom Lendacky	---help---
15287744ccdbSTom Lendacky	  Say yes to enable support for the encryption of system memory.
15297744ccdbSTom Lendacky	  This requires an AMD processor that supports Secure Memory
15307744ccdbSTom Lendacky	  Encryption (SME).
15317744ccdbSTom Lendacky
15327744ccdbSTom Lendackyconfig AMD_MEM_ENCRYPT_ACTIVE_BY_DEFAULT
15337744ccdbSTom Lendacky	bool "Activate AMD Secure Memory Encryption (SME) by default"
15347744ccdbSTom Lendacky	default y
15357744ccdbSTom Lendacky	depends on AMD_MEM_ENCRYPT
15367744ccdbSTom Lendacky	---help---
15377744ccdbSTom Lendacky	  Say yes to have system memory encrypted by default if running on
15387744ccdbSTom Lendacky	  an AMD processor that supports Secure Memory Encryption (SME).
15397744ccdbSTom Lendacky
15407744ccdbSTom Lendacky	  If set to Y, then the encryption of system memory can be
15417744ccdbSTom Lendacky	  deactivated with the mem_encrypt=off command line option.
15427744ccdbSTom Lendacky
15437744ccdbSTom Lendacky	  If set to N, then the encryption of system memory can be
15447744ccdbSTom Lendacky	  activated with the mem_encrypt=on command line option.
15457744ccdbSTom Lendacky
1546506f1d07SSam Ravnborg# Common NUMA Features
1547506f1d07SSam Ravnborgconfig NUMA
1548e133f6eaSRandy Dunlap	bool "NUMA Memory Allocation and Scheduler Support"
1549506f1d07SSam Ravnborg	depends on SMP
1550b5660ba7SH. Peter Anvin	depends on X86_64 || (X86_32 && HIGHMEM64G && X86_BIGSMP)
1551b5660ba7SH. Peter Anvin	default y if X86_BIGSMP
15528f9ca475SIngo Molnar	---help---
1553e133f6eaSRandy Dunlap	  Enable NUMA (Non-Uniform Memory Access) support.
1554fd51b2d7SKOSAKI Motohiro
1555506f1d07SSam Ravnborg	  The kernel will try to allocate memory used by a CPU on the
1556506f1d07SSam Ravnborg	  local memory controller of the CPU and add some more
1557506f1d07SSam Ravnborg	  NUMA awareness to the kernel.
1558506f1d07SSam Ravnborg
1559c280ea5eSIngo Molnar	  For 64-bit this is recommended if the system is Intel Core i7
1560fd51b2d7SKOSAKI Motohiro	  (or later), AMD Opteron, or EM64T NUMA.
1561fd51b2d7SKOSAKI Motohiro
1562b5660ba7SH. Peter Anvin	  For 32-bit this is only needed if you boot a 32-bit
15637cf6c945SDavid Rientjes	  kernel on a 64-bit NUMA platform.
1564fd51b2d7SKOSAKI Motohiro
1565fd51b2d7SKOSAKI Motohiro	  Otherwise, you should say N.
1566506f1d07SSam Ravnborg
1567eec1d4faSHans Rosenfeldconfig AMD_NUMA
15683c2362e6SHarvey Harrison	def_bool y
15693c2362e6SHarvey Harrison	prompt "Old style AMD Opteron NUMA detection"
15705da0ef9aSTejun Heo	depends on X86_64 && NUMA && PCI
15718f9ca475SIngo Molnar	---help---
1572eec1d4faSHans Rosenfeld	  Enable AMD NUMA node topology detection.  You should say Y here if
1573eec1d4faSHans Rosenfeld	  you have a multi processor AMD system. This uses an old method to
1574eec1d4faSHans Rosenfeld	  read the NUMA configuration directly from the builtin Northbridge
1575eec1d4faSHans Rosenfeld	  of Opteron. It is recommended to use X86_64_ACPI_NUMA instead,
1576eec1d4faSHans Rosenfeld	  which also takes priority if both are compiled in.
1577506f1d07SSam Ravnborg
1578506f1d07SSam Ravnborgconfig X86_64_ACPI_NUMA
15793c2362e6SHarvey Harrison	def_bool y
15803c2362e6SHarvey Harrison	prompt "ACPI NUMA detection"
1581506f1d07SSam Ravnborg	depends on X86_64 && NUMA && ACPI && PCI
1582506f1d07SSam Ravnborg	select ACPI_NUMA
15838f9ca475SIngo Molnar	---help---
1584506f1d07SSam Ravnborg	  Enable ACPI SRAT based node topology detection.
1585506f1d07SSam Ravnborg
15866ec6e0d9SSuresh Siddha# Some NUMA nodes have memory ranges that span
15876ec6e0d9SSuresh Siddha# other nodes.  Even though a pfn is valid and
15886ec6e0d9SSuresh Siddha# between a node's start and end pfns, it may not
15896ec6e0d9SSuresh Siddha# reside on that node.  See memmap_init_zone()
15906ec6e0d9SSuresh Siddha# for details.
15916ec6e0d9SSuresh Siddhaconfig NODES_SPAN_OTHER_NODES
15926ec6e0d9SSuresh Siddha	def_bool y
15936ec6e0d9SSuresh Siddha	depends on X86_64_ACPI_NUMA
15946ec6e0d9SSuresh Siddha
1595506f1d07SSam Ravnborgconfig NUMA_EMU
1596506f1d07SSam Ravnborg	bool "NUMA emulation"
15971b7e03efSTejun Heo	depends on NUMA
15988f9ca475SIngo Molnar	---help---
1599506f1d07SSam Ravnborg	  Enable NUMA emulation. A flat machine will be split
1600506f1d07SSam Ravnborg	  into virtual nodes when booted with "numa=fake=N", where N is the
1601506f1d07SSam Ravnborg	  number of nodes. This is only useful for debugging.
1602506f1d07SSam Ravnborg
1603506f1d07SSam Ravnborgconfig NODES_SHIFT
1604d25e26b6SLinus Torvalds	int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP
160551591e31SDavid Rientjes	range 1 10
160651591e31SDavid Rientjes	default "10" if MAXSMP
1607506f1d07SSam Ravnborg	default "6" if X86_64
1608506f1d07SSam Ravnborg	default "3"
1609506f1d07SSam Ravnborg	depends on NEED_MULTIPLE_NODES
16108f9ca475SIngo Molnar	---help---
16111184dc2fSMike Travis	  Specify the maximum number of NUMA Nodes available on the target
1612692105b8SMatt LaPlante	  system.  Increases memory reserved to accommodate various tables.
1613506f1d07SSam Ravnborg
1614506f1d07SSam Ravnborgconfig ARCH_HAVE_MEMORY_PRESENT
16153c2362e6SHarvey Harrison	def_bool y
1616506f1d07SSam Ravnborg	depends on X86_32 && DISCONTIGMEM
1617506f1d07SSam Ravnborg
1618506f1d07SSam Ravnborgconfig ARCH_FLATMEM_ENABLE
1619506f1d07SSam Ravnborg	def_bool y
16203b16651fSTejun Heo	depends on X86_32 && !NUMA
1621506f1d07SSam Ravnborg
1622506f1d07SSam Ravnborgconfig ARCH_DISCONTIGMEM_ENABLE
16232792107dSMike Rapoport	def_bool n
1624b263295dSChristoph Lameter	depends on NUMA && X86_32
16252792107dSMike Rapoport	depends on BROKEN
1626b263295dSChristoph Lameter
1627506f1d07SSam Ravnborgconfig ARCH_SPARSEMEM_ENABLE
1628506f1d07SSam Ravnborg	def_bool y
16296ea30386SKees Cook	depends on X86_64 || NUMA || X86_32 || X86_32_NON_STANDARD
1630506f1d07SSam Ravnborg	select SPARSEMEM_STATIC if X86_32
1631506f1d07SSam Ravnborg	select SPARSEMEM_VMEMMAP_ENABLE if X86_64
1632506f1d07SSam Ravnborg
16333b16651fSTejun Heoconfig ARCH_SPARSEMEM_DEFAULT
16346ad57f7fSMike Rapoport	def_bool X86_64 || (NUMA && X86_32)
16353b16651fSTejun Heo
1636506f1d07SSam Ravnborgconfig ARCH_SELECT_MEMORY_MODEL
1637506f1d07SSam Ravnborg	def_bool y
1638b263295dSChristoph Lameter	depends on ARCH_SPARSEMEM_ENABLE
1639506f1d07SSam Ravnborg
1640506f1d07SSam Ravnborgconfig ARCH_MEMORY_PROBE
1641a0842b70SToshi Kani	bool "Enable sysfs memory/probe interface"
16423120e25eSJan Beulich	depends on X86_64 && MEMORY_HOTPLUG
1643a0842b70SToshi Kani	help
1644a0842b70SToshi Kani	  This option enables a sysfs memory/probe interface for testing.
1645cb1aaebeSMauro Carvalho Chehab	  See Documentation/admin-guide/mm/memory-hotplug.rst for more information.
1646a0842b70SToshi Kani	  If you are unsure how to answer this question, answer N.
1647506f1d07SSam Ravnborg
16483b16651fSTejun Heoconfig ARCH_PROC_KCORE_TEXT
16493b16651fSTejun Heo	def_bool y
16503b16651fSTejun Heo	depends on X86_64 && PROC_KCORE
16513b16651fSTejun Heo
1652a29815a3SAvi Kivityconfig ILLEGAL_POINTER_VALUE
1653a29815a3SAvi Kivity	hex
1654a29815a3SAvi Kivity	default 0 if X86_32
1655a29815a3SAvi Kivity	default 0xdead000000000000 if X86_64
1656a29815a3SAvi Kivity
16577a67832cSDan Williamsconfig X86_PMEM_LEGACY_DEVICE
16587a67832cSDan Williams	bool
16597a67832cSDan Williams
1660ec776ef6SChristoph Hellwigconfig X86_PMEM_LEGACY
16617a67832cSDan Williams	tristate "Support non-standard NVDIMMs and ADR protected memory"
16629f53f9faSDan Williams	depends on PHYS_ADDR_T_64BIT
16639f53f9faSDan Williams	depends on BLK_DEV
16647a67832cSDan Williams	select X86_PMEM_LEGACY_DEVICE
16657b27a862SDan Williams	select NUMA_KEEP_MEMINFO if NUMA
16669f53f9faSDan Williams	select LIBNVDIMM
1667ec776ef6SChristoph Hellwig	help
1668ec776ef6SChristoph Hellwig	  Treat memory marked using the non-standard e820 type of 12 as used
1669ec776ef6SChristoph Hellwig	  by the Intel Sandy Bridge-EP reference BIOS as protected memory.
1670ec776ef6SChristoph Hellwig	  The kernel will offer these regions to the 'pmem' driver so
1671ec776ef6SChristoph Hellwig	  they can be used for persistent storage.
1672ec776ef6SChristoph Hellwig
1673ec776ef6SChristoph Hellwig	  Say Y if unsure.
1674ec776ef6SChristoph Hellwig
1675506f1d07SSam Ravnborgconfig HIGHPTE
1676506f1d07SSam Ravnborg	bool "Allocate 3rd-level pagetables from highmem"
16776fc108a0SJan Beulich	depends on HIGHMEM
16788f9ca475SIngo Molnar	---help---
1679506f1d07SSam Ravnborg	  The VM uses one page table entry for each page of physical memory.
1680506f1d07SSam Ravnborg	  For systems with a lot of RAM, this can be wasteful of precious
1681506f1d07SSam Ravnborg	  low memory.  Setting this option will put user-space page table
1682506f1d07SSam Ravnborg	  entries in high memory.
1683506f1d07SSam Ravnborg
16849f077871SJeremy Fitzhardingeconfig X86_CHECK_BIOS_CORRUPTION
16859f077871SJeremy Fitzhardinge	bool "Check for low memory corruption"
16868f9ca475SIngo Molnar	---help---
16879f077871SJeremy Fitzhardinge	  Periodically check for memory corruption in low memory, which
16889f077871SJeremy Fitzhardinge	  is suspected to be caused by BIOS.  Even when enabled in the
16899f077871SJeremy Fitzhardinge	  configuration, it is disabled at runtime.  Enable it by
16909f077871SJeremy Fitzhardinge	  setting "memory_corruption_check=1" on the kernel command
16919f077871SJeremy Fitzhardinge	  line.  By default it scans the low 64k of memory every 60
16929f077871SJeremy Fitzhardinge	  seconds; see the memory_corruption_check_size and
16939f077871SJeremy Fitzhardinge	  memory_corruption_check_period parameters in
16948c27ceffSMauro Carvalho Chehab	  Documentation/admin-guide/kernel-parameters.rst to adjust this.
16959f077871SJeremy Fitzhardinge
16969f077871SJeremy Fitzhardinge	  When enabled with the default parameters, this option has
16979f077871SJeremy Fitzhardinge	  almost no overhead, as it reserves a relatively small amount
16989f077871SJeremy Fitzhardinge	  of memory and scans it infrequently.  It both detects corruption
16999f077871SJeremy Fitzhardinge	  and prevents it from affecting the running system.
17009f077871SJeremy Fitzhardinge
17019f077871SJeremy Fitzhardinge	  It is, however, intended as a diagnostic tool; if repeatable
17029f077871SJeremy Fitzhardinge	  BIOS-originated corruption always affects the same memory,
17039f077871SJeremy Fitzhardinge	  you can use memmap= to prevent the kernel from using that
17049f077871SJeremy Fitzhardinge	  memory.
17059f077871SJeremy Fitzhardinge
1706c885df50SJeremy Fitzhardingeconfig X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK
1707c885df50SJeremy Fitzhardinge	bool "Set the default setting of memory_corruption_check"
1708c885df50SJeremy Fitzhardinge	depends on X86_CHECK_BIOS_CORRUPTION
1709c885df50SJeremy Fitzhardinge	default y
17108f9ca475SIngo Molnar	---help---
1711c885df50SJeremy Fitzhardinge	  Set whether the default state of memory_corruption_check is
1712c885df50SJeremy Fitzhardinge	  on or off.
1713c885df50SJeremy Fitzhardinge
17149ea77bdbSH. Peter Anvinconfig X86_RESERVE_LOW
1715d0cd7425SH. Peter Anvin	int "Amount of low memory, in kilobytes, to reserve for the BIOS"
1716d0cd7425SH. Peter Anvin	default 64
1717d0cd7425SH. Peter Anvin	range 4 640
17188f9ca475SIngo Molnar	---help---
1719d0cd7425SH. Peter Anvin	  Specify the amount of low memory to reserve for the BIOS.
1720fc381519SIngo Molnar
1721d0cd7425SH. Peter Anvin	  The first page contains BIOS data structures that the kernel
1722d0cd7425SH. Peter Anvin	  must not use, so that page must always be reserved.
1723fc381519SIngo Molnar
1724d0cd7425SH. Peter Anvin	  By default we reserve the first 64K of physical RAM, as a
1725d0cd7425SH. Peter Anvin	  number of BIOSes are known to corrupt that memory range
1726d0cd7425SH. Peter Anvin	  during events such as suspend/resume or monitor cable
1727d0cd7425SH. Peter Anvin	  insertion, so it must not be used by the kernel.
1728fc381519SIngo Molnar
1729d0cd7425SH. Peter Anvin	  You can set this to 4 if you are absolutely sure that you
1730d0cd7425SH. Peter Anvin	  trust the BIOS to get all its memory reservations and usages
1731d0cd7425SH. Peter Anvin	  right.  If you know your BIOS have problems beyond the
1732d0cd7425SH. Peter Anvin	  default 64K area, you can set this to 640 to avoid using the
1733d0cd7425SH. Peter Anvin	  entire low memory range.
1734d0cd7425SH. Peter Anvin
1735d0cd7425SH. Peter Anvin	  If you have doubts about the BIOS (e.g. suspend/resume does
1736d0cd7425SH. Peter Anvin	  not work or there's kernel crashes after certain hardware
1737d0cd7425SH. Peter Anvin	  hotplug events) then you might want to enable
1738d0cd7425SH. Peter Anvin	  X86_CHECK_BIOS_CORRUPTION=y to allow the kernel to check
1739d0cd7425SH. Peter Anvin	  typical corruption patterns.
1740d0cd7425SH. Peter Anvin
1741d0cd7425SH. Peter Anvin	  Leave this to the default value of 64 if you are unsure.
1742fc381519SIngo Molnar
1743506f1d07SSam Ravnborgconfig MATH_EMULATION
1744506f1d07SSam Ravnborg	bool
1745a5b9e5a2SAndy Lutomirski	depends on MODIFY_LDT_SYSCALL
174687d6021bSArnd Bergmann	prompt "Math emulation" if X86_32 && (M486SX || MELAN)
1747506f1d07SSam Ravnborg	---help---
1748506f1d07SSam Ravnborg	  Linux can emulate a math coprocessor (used for floating point
1749506f1d07SSam Ravnborg	  operations) if you don't have one. 486DX and Pentium processors have
1750506f1d07SSam Ravnborg	  a math coprocessor built in, 486SX and 386 do not, unless you added
1751506f1d07SSam Ravnborg	  a 487DX or 387, respectively. (The messages during boot time can
1752506f1d07SSam Ravnborg	  give you some hints here ["man dmesg"].) Everyone needs either a
1753506f1d07SSam Ravnborg	  coprocessor or this emulation.
1754506f1d07SSam Ravnborg
1755506f1d07SSam Ravnborg	  If you don't have a math coprocessor, you need to say Y here; if you
1756506f1d07SSam Ravnborg	  say Y here even though you have a coprocessor, the coprocessor will
1757506f1d07SSam Ravnborg	  be used nevertheless. (This behavior can be changed with the kernel
1758506f1d07SSam Ravnborg	  command line option "no387", which comes handy if your coprocessor
1759506f1d07SSam Ravnborg	  is broken. Try "man bootparam" or see the documentation of your boot
1760506f1d07SSam Ravnborg	  loader (lilo or loadlin) about how to pass options to the kernel at
1761506f1d07SSam Ravnborg	  boot time.) This means that it is a good idea to say Y here if you
1762506f1d07SSam Ravnborg	  intend to use this kernel on different machines.
1763506f1d07SSam Ravnborg
1764506f1d07SSam Ravnborg	  More information about the internals of the Linux math coprocessor
1765506f1d07SSam Ravnborg	  emulation can be found in <file:arch/x86/math-emu/README>.
1766506f1d07SSam Ravnborg
1767506f1d07SSam Ravnborg	  If you are not sure, say Y; apart from resulting in a 66 KB bigger
1768506f1d07SSam Ravnborg	  kernel, it won't hurt.
1769506f1d07SSam Ravnborg
1770506f1d07SSam Ravnborgconfig MTRR
17716fc108a0SJan Beulich	def_bool y
17726a108a14SDavid Rientjes	prompt "MTRR (Memory Type Range Register) support" if EXPERT
1773506f1d07SSam Ravnborg	---help---
1774506f1d07SSam Ravnborg	  On Intel P6 family processors (Pentium Pro, Pentium II and later)
1775506f1d07SSam Ravnborg	  the Memory Type Range Registers (MTRRs) may be used to control
1776506f1d07SSam Ravnborg	  processor access to memory ranges. This is most useful if you have
1777506f1d07SSam Ravnborg	  a video (VGA) card on a PCI or AGP bus. Enabling write-combining
1778506f1d07SSam Ravnborg	  allows bus write transfers to be combined into a larger transfer
1779506f1d07SSam Ravnborg	  before bursting over the PCI/AGP bus. This can increase performance
1780506f1d07SSam Ravnborg	  of image write operations 2.5 times or more. Saying Y here creates a
1781506f1d07SSam Ravnborg	  /proc/mtrr file which may be used to manipulate your processor's
1782506f1d07SSam Ravnborg	  MTRRs. Typically the X server should use this.
1783506f1d07SSam Ravnborg
1784506f1d07SSam Ravnborg	  This code has a reasonably generic interface so that similar
1785506f1d07SSam Ravnborg	  control registers on other processors can be easily supported
1786506f1d07SSam Ravnborg	  as well:
1787506f1d07SSam Ravnborg
1788506f1d07SSam Ravnborg	  The Cyrix 6x86, 6x86MX and M II processors have Address Range
1789506f1d07SSam Ravnborg	  Registers (ARRs) which provide a similar functionality to MTRRs. For
1790506f1d07SSam Ravnborg	  these, the ARRs are used to emulate the MTRRs.
1791506f1d07SSam Ravnborg	  The AMD K6-2 (stepping 8 and above) and K6-3 processors have two
1792506f1d07SSam Ravnborg	  MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing
1793506f1d07SSam Ravnborg	  write-combining. All of these processors are supported by this code
1794506f1d07SSam Ravnborg	  and it makes sense to say Y here if you have one of them.
1795506f1d07SSam Ravnborg
1796506f1d07SSam Ravnborg	  Saying Y here also fixes a problem with buggy SMP BIOSes which only
1797506f1d07SSam Ravnborg	  set the MTRRs for the boot CPU and not for the secondary CPUs. This
1798506f1d07SSam Ravnborg	  can lead to all sorts of problems, so it's good to say Y here.
1799506f1d07SSam Ravnborg
1800506f1d07SSam Ravnborg	  You can safely say Y even if your machine doesn't have MTRRs, you'll
1801506f1d07SSam Ravnborg	  just add about 9 KB to your kernel.
1802506f1d07SSam Ravnborg
1803cb1aaebeSMauro Carvalho Chehab	  See <file:Documentation/x86/mtrr.rst> for more information.
1804506f1d07SSam Ravnborg
180595ffa243SYinghai Luconfig MTRR_SANITIZER
18062ffb3501SYinghai Lu	def_bool y
180795ffa243SYinghai Lu	prompt "MTRR cleanup support"
180895ffa243SYinghai Lu	depends on MTRR
18098f9ca475SIngo Molnar	---help---
1810aba3728cSThomas Gleixner	  Convert MTRR layout from continuous to discrete, so X drivers can
1811aba3728cSThomas Gleixner	  add writeback entries.
181295ffa243SYinghai Lu
1813aba3728cSThomas Gleixner	  Can be disabled with disable_mtrr_cleanup on the kernel command line.
1814692105b8SMatt LaPlante	  The largest mtrr entry size for a continuous block can be set with
1815aba3728cSThomas Gleixner	  mtrr_chunk_size.
181695ffa243SYinghai Lu
18172ffb3501SYinghai Lu	  If unsure, say Y.
181895ffa243SYinghai Lu
181995ffa243SYinghai Luconfig MTRR_SANITIZER_ENABLE_DEFAULT
1820f5098d62SYinghai Lu	int "MTRR cleanup enable value (0-1)"
1821f5098d62SYinghai Lu	range 0 1
1822f5098d62SYinghai Lu	default "0"
182395ffa243SYinghai Lu	depends on MTRR_SANITIZER
18248f9ca475SIngo Molnar	---help---
1825f5098d62SYinghai Lu	  Enable mtrr cleanup default value
182695ffa243SYinghai Lu
182712031a62SYinghai Luconfig MTRR_SANITIZER_SPARE_REG_NR_DEFAULT
182812031a62SYinghai Lu	int "MTRR cleanup spare reg num (0-7)"
182912031a62SYinghai Lu	range 0 7
183012031a62SYinghai Lu	default "1"
183112031a62SYinghai Lu	depends on MTRR_SANITIZER
18328f9ca475SIngo Molnar	---help---
183312031a62SYinghai Lu	  mtrr cleanup spare entries default, it can be changed via
1834aba3728cSThomas Gleixner	  mtrr_spare_reg_nr=N on the kernel command line.
183512031a62SYinghai Lu
18362e5d9c85Svenkatesh.pallipadi@intel.comconfig X86_PAT
18376fc108a0SJan Beulich	def_bool y
18386a108a14SDavid Rientjes	prompt "x86 PAT support" if EXPERT
18392a8a2719SIngo Molnar	depends on MTRR
18408f9ca475SIngo Molnar	---help---
18412e5d9c85Svenkatesh.pallipadi@intel.com	  Use PAT attributes to setup page level cache control.
1842042b78e4SVenki Pallipadi
18432e5d9c85Svenkatesh.pallipadi@intel.com	  PATs are the modern equivalents of MTRRs and are much more
18442e5d9c85Svenkatesh.pallipadi@intel.com	  flexible than MTRRs.
18452e5d9c85Svenkatesh.pallipadi@intel.com
18462e5d9c85Svenkatesh.pallipadi@intel.com	  Say N here if you see bootup problems (boot crash, boot hang,
1847042b78e4SVenki Pallipadi	  spontaneous reboots) or a non-working video driver.
18482e5d9c85Svenkatesh.pallipadi@intel.com
18492e5d9c85Svenkatesh.pallipadi@intel.com	  If unsure, say Y.
18502e5d9c85Svenkatesh.pallipadi@intel.com
185146cf98cdSVenkatesh Pallipadiconfig ARCH_USES_PG_UNCACHED
185246cf98cdSVenkatesh Pallipadi	def_bool y
185346cf98cdSVenkatesh Pallipadi	depends on X86_PAT
185446cf98cdSVenkatesh Pallipadi
1855628c6246SH. Peter Anvinconfig ARCH_RANDOM
1856628c6246SH. Peter Anvin	def_bool y
1857628c6246SH. Peter Anvin	prompt "x86 architectural random number generator" if EXPERT
1858628c6246SH. Peter Anvin	---help---
1859628c6246SH. Peter Anvin	  Enable the x86 architectural RDRAND instruction
1860628c6246SH. Peter Anvin	  (Intel Bull Mountain technology) to generate random numbers.
1861628c6246SH. Peter Anvin	  If supported, this is a high bandwidth, cryptographically
1862628c6246SH. Peter Anvin	  secure hardware random number generator.
1863628c6246SH. Peter Anvin
186451ae4a2dSH. Peter Anvinconfig X86_SMAP
186551ae4a2dSH. Peter Anvin	def_bool y
186651ae4a2dSH. Peter Anvin	prompt "Supervisor Mode Access Prevention" if EXPERT
186751ae4a2dSH. Peter Anvin	---help---
186851ae4a2dSH. Peter Anvin	  Supervisor Mode Access Prevention (SMAP) is a security
186951ae4a2dSH. Peter Anvin	  feature in newer Intel processors.  There is a small
187051ae4a2dSH. Peter Anvin	  performance cost if this enabled and turned on; there is
187151ae4a2dSH. Peter Anvin	  also a small increase in the kernel size if this is enabled.
187251ae4a2dSH. Peter Anvin
187351ae4a2dSH. Peter Anvin	  If unsure, say Y.
187451ae4a2dSH. Peter Anvin
1875b971880fSBabu Mogerconfig X86_UMIP
1876796ebc81SRicardo Neri	def_bool y
1877b971880fSBabu Moger	prompt "User Mode Instruction Prevention" if EXPERT
1878aa35f896SRicardo Neri	---help---
1879b971880fSBabu Moger	  User Mode Instruction Prevention (UMIP) is a security feature in
1880b971880fSBabu Moger	  some x86 processors. If enabled, a general protection fault is
1881b971880fSBabu Moger	  issued if the SGDT, SLDT, SIDT, SMSW or STR instructions are
1882b971880fSBabu Moger	  executed in user mode. These instructions unnecessarily expose
1883b971880fSBabu Moger	  information about the hardware state.
1884796ebc81SRicardo Neri
1885796ebc81SRicardo Neri	  The vast majority of applications do not use these instructions.
1886796ebc81SRicardo Neri	  For the very few that do, software emulation is provided in
1887796ebc81SRicardo Neri	  specific cases in protected and virtual-8086 modes. Emulated
1888796ebc81SRicardo Neri	  results are dummy.
1889aa35f896SRicardo Neri
189035e97790SDave Hansenconfig X86_INTEL_MEMORY_PROTECTION_KEYS
1891284244a9SDave Hansen	prompt "Intel Memory Protection Keys"
189235e97790SDave Hansen	def_bool y
1893284244a9SDave Hansen	# Note: only available in 64-bit mode
189435e97790SDave Hansen	depends on CPU_SUP_INTEL && X86_64
189552c8e601SIngo Molnar	select ARCH_USES_HIGH_VMA_FLAGS
189652c8e601SIngo Molnar	select ARCH_HAS_PKEYS
1897284244a9SDave Hansen	---help---
1898284244a9SDave Hansen	  Memory Protection Keys provides a mechanism for enforcing
1899284244a9SDave Hansen	  page-based protections, but without requiring modification of the
1900284244a9SDave Hansen	  page tables when an application changes protection domains.
1901284244a9SDave Hansen
19021eecbcdcSMauro Carvalho Chehab	  For details, see Documentation/core-api/protection-keys.rst
1903284244a9SDave Hansen
1904284244a9SDave Hansen	  If unsure, say y.
190535e97790SDave Hansen
1906db616173SMichal Hockochoice
1907db616173SMichal Hocko	prompt "TSX enable mode"
1908db616173SMichal Hocko	depends on CPU_SUP_INTEL
1909db616173SMichal Hocko	default X86_INTEL_TSX_MODE_OFF
1910db616173SMichal Hocko	help
1911db616173SMichal Hocko	  Intel's TSX (Transactional Synchronization Extensions) feature
1912db616173SMichal Hocko	  allows to optimize locking protocols through lock elision which
1913db616173SMichal Hocko	  can lead to a noticeable performance boost.
1914db616173SMichal Hocko
1915db616173SMichal Hocko	  On the other hand it has been shown that TSX can be exploited
1916db616173SMichal Hocko	  to form side channel attacks (e.g. TAA) and chances are there
1917db616173SMichal Hocko	  will be more of those attacks discovered in the future.
1918db616173SMichal Hocko
1919db616173SMichal Hocko	  Therefore TSX is not enabled by default (aka tsx=off). An admin
1920db616173SMichal Hocko	  might override this decision by tsx=on the command line parameter.
1921db616173SMichal Hocko	  Even with TSX enabled, the kernel will attempt to enable the best
1922db616173SMichal Hocko	  possible TAA mitigation setting depending on the microcode available
1923db616173SMichal Hocko	  for the particular machine.
1924db616173SMichal Hocko
1925db616173SMichal Hocko	  This option allows to set the default tsx mode between tsx=on, =off
1926db616173SMichal Hocko	  and =auto. See Documentation/admin-guide/kernel-parameters.txt for more
1927db616173SMichal Hocko	  details.
1928db616173SMichal Hocko
1929db616173SMichal Hocko	  Say off if not sure, auto if TSX is in use but it should be used on safe
1930db616173SMichal Hocko	  platforms or on if TSX is in use and the security aspect of tsx is not
1931db616173SMichal Hocko	  relevant.
1932db616173SMichal Hocko
1933db616173SMichal Hockoconfig X86_INTEL_TSX_MODE_OFF
1934db616173SMichal Hocko	bool "off"
1935db616173SMichal Hocko	help
1936db616173SMichal Hocko	  TSX is disabled if possible - equals to tsx=off command line parameter.
1937db616173SMichal Hocko
1938db616173SMichal Hockoconfig X86_INTEL_TSX_MODE_ON
1939db616173SMichal Hocko	bool "on"
1940db616173SMichal Hocko	help
1941db616173SMichal Hocko	  TSX is always enabled on TSX capable HW - equals the tsx=on command
1942db616173SMichal Hocko	  line parameter.
1943db616173SMichal Hocko
1944db616173SMichal Hockoconfig X86_INTEL_TSX_MODE_AUTO
1945db616173SMichal Hocko	bool "auto"
1946db616173SMichal Hocko	help
1947db616173SMichal Hocko	  TSX is enabled on TSX capable HW that is believed to be safe against
1948db616173SMichal Hocko	  side channel attacks- equals the tsx=auto command line parameter.
1949db616173SMichal Hockoendchoice
1950db616173SMichal Hocko
1951506f1d07SSam Ravnborgconfig EFI
19529ba16087SJan Beulich	bool "EFI runtime service support"
19535b83683fSHuang, Ying	depends on ACPI
1954f6ce5002SSergey Vlasov	select UCS2_STRING
1955022ee6c5SArd Biesheuvel	select EFI_RUNTIME_WRAPPERS
1956506f1d07SSam Ravnborg	---help---
19578b2cb7a8SHuang, Ying	  This enables the kernel to use EFI runtime services that are
1958506f1d07SSam Ravnborg	  available (such as the EFI variable services).
1959506f1d07SSam Ravnborg
19608b2cb7a8SHuang, Ying	  This option is only useful on systems that have EFI firmware.
19618b2cb7a8SHuang, Ying	  In addition, you should use the latest ELILO loader available
19628b2cb7a8SHuang, Ying	  at <http://elilo.sourceforge.net> in order to take advantage
19638b2cb7a8SHuang, Ying	  of EFI runtime services. However, even with this option, the
19648b2cb7a8SHuang, Ying	  resultant kernel should continue to boot on existing non-EFI
19658b2cb7a8SHuang, Ying	  platforms.
1966506f1d07SSam Ravnborg
1967291f3632SMatt Flemingconfig EFI_STUB
1968291f3632SMatt Fleming	bool "EFI stub support"
1969b16d8c23SMatt Fleming	depends on EFI && !X86_USE_3DNOW
19708f24f8c2SArd Biesheuvel	depends on $(cc-option,-mabi=ms) || X86_32
19717b2a583aSMatt Fleming	select RELOCATABLE
1972291f3632SMatt Fleming	---help---
1973291f3632SMatt Fleming	  This kernel feature allows a bzImage to be loaded directly
1974291f3632SMatt Fleming	  by EFI firmware without the use of a bootloader.
1975291f3632SMatt Fleming
19764f4cfa6cSMauro Carvalho Chehab	  See Documentation/admin-guide/efi-stub.rst for more information.
19770c759662SMatt Fleming
19787d453eeeSMatt Flemingconfig EFI_MIXED
19797d453eeeSMatt Fleming	bool "EFI mixed-mode support"
19807d453eeeSMatt Fleming	depends on EFI_STUB && X86_64
19817d453eeeSMatt Fleming	---help---
19827d453eeeSMatt Fleming	   Enabling this feature allows a 64-bit kernel to be booted
19837d453eeeSMatt Fleming	   on a 32-bit firmware, provided that your CPU supports 64-bit
19847d453eeeSMatt Fleming	   mode.
19857d453eeeSMatt Fleming
19867d453eeeSMatt Fleming	   Note that it is not possible to boot a mixed-mode enabled
19877d453eeeSMatt Fleming	   kernel via the EFI boot stub - a bootloader that supports
19887d453eeeSMatt Fleming	   the EFI handover protocol must be used.
19897d453eeeSMatt Fleming
19907d453eeeSMatt Fleming	   If unsure, say N.
19917d453eeeSMatt Fleming
1992506f1d07SSam Ravnborgconfig SECCOMP
19933c2362e6SHarvey Harrison	def_bool y
19943c2362e6SHarvey Harrison	prompt "Enable seccomp to safely compute untrusted bytecode"
19958f9ca475SIngo Molnar	---help---
1996506f1d07SSam Ravnborg	  This kernel feature is useful for number crunching applications
1997506f1d07SSam Ravnborg	  that may need to compute untrusted bytecode during their
1998506f1d07SSam Ravnborg	  execution. By using pipes or other transports made available to
1999506f1d07SSam Ravnborg	  the process as file descriptors supporting the read/write
2000506f1d07SSam Ravnborg	  syscalls, it's possible to isolate those applications in
2001506f1d07SSam Ravnborg	  their own address space using seccomp. Once seccomp is
20029c0bbee8SAlexey Dobriyan	  enabled via prctl(PR_SET_SECCOMP), it cannot be disabled
2003506f1d07SSam Ravnborg	  and the task is only allowed to execute a few safe syscalls
2004506f1d07SSam Ravnborg	  defined by each seccomp mode.
2005506f1d07SSam Ravnborg
2006506f1d07SSam Ravnborg	  If unsure, say Y. Only embedded should say N here.
2007506f1d07SSam Ravnborg
20088636a1f9SMasahiro Yamadasource "kernel/Kconfig.hz"
2009506f1d07SSam Ravnborg
2010506f1d07SSam Ravnborgconfig KEXEC
2011506f1d07SSam Ravnborg	bool "kexec system call"
20122965faa5SDave Young	select KEXEC_CORE
20138f9ca475SIngo Molnar	---help---
2014506f1d07SSam Ravnborg	  kexec is a system call that implements the ability to shutdown your
2015506f1d07SSam Ravnborg	  current kernel, and to start another kernel.  It is like a reboot
2016506f1d07SSam Ravnborg	  but it is independent of the system firmware.   And like a reboot
2017506f1d07SSam Ravnborg	  you can start any kernel with it, not just Linux.
2018506f1d07SSam Ravnborg
2019506f1d07SSam Ravnborg	  The name comes from the similarity to the exec system call.
2020506f1d07SSam Ravnborg
2021506f1d07SSam Ravnborg	  It is an ongoing process to be certain the hardware in a machine
2022506f1d07SSam Ravnborg	  is properly shutdown, so do not be surprised if this code does not
2023bf220695SGeert Uytterhoeven	  initially work for you.  As of this writing the exact hardware
2024bf220695SGeert Uytterhoeven	  interface is strongly in flux, so no good recommendation can be
2025bf220695SGeert Uytterhoeven	  made.
2026506f1d07SSam Ravnborg
202774ca317cSVivek Goyalconfig KEXEC_FILE
202874ca317cSVivek Goyal	bool "kexec file based system call"
20292965faa5SDave Young	select KEXEC_CORE
203074ca317cSVivek Goyal	select BUILD_BIN2C
203174ca317cSVivek Goyal	depends on X86_64
203274ca317cSVivek Goyal	depends on CRYPTO=y
203374ca317cSVivek Goyal	depends on CRYPTO_SHA256=y
203474ca317cSVivek Goyal	---help---
203574ca317cSVivek Goyal	  This is new version of kexec system call. This system call is
203674ca317cSVivek Goyal	  file based and takes file descriptors as system call argument
203774ca317cSVivek Goyal	  for kernel and initramfs as opposed to list of segments as
203874ca317cSVivek Goyal	  accepted by previous system call.
203974ca317cSVivek Goyal
2040b799a09fSAKASHI Takahiroconfig ARCH_HAS_KEXEC_PURGATORY
2041b799a09fSAKASHI Takahiro	def_bool KEXEC_FILE
2042b799a09fSAKASHI Takahiro
204399d5cadfSJiri Bohacconfig KEXEC_SIG
20448e7d8381SVivek Goyal	bool "Verify kernel signature during kexec_file_load() syscall"
204574ca317cSVivek Goyal	depends on KEXEC_FILE
20468e7d8381SVivek Goyal	---help---
204799d5cadfSJiri Bohac
204899d5cadfSJiri Bohac	  This option makes the kexec_file_load() syscall check for a valid
204999d5cadfSJiri Bohac	  signature of the kernel image.  The image can still be loaded without
205099d5cadfSJiri Bohac	  a valid signature unless you also enable KEXEC_SIG_FORCE, though if
205199d5cadfSJiri Bohac	  there's a signature that we can check, then it must be valid.
205299d5cadfSJiri Bohac
205399d5cadfSJiri Bohac	  In addition to this option, you need to enable signature
205499d5cadfSJiri Bohac	  verification for the corresponding kernel image type being
205599d5cadfSJiri Bohac	  loaded in order for this to work.
205699d5cadfSJiri Bohac
205799d5cadfSJiri Bohacconfig KEXEC_SIG_FORCE
205899d5cadfSJiri Bohac	bool "Require a valid signature in kexec_file_load() syscall"
205999d5cadfSJiri Bohac	depends on KEXEC_SIG
206099d5cadfSJiri Bohac	---help---
20618e7d8381SVivek Goyal	  This option makes kernel signature verification mandatory for
2062d8eb8940SBorislav Petkov	  the kexec_file_load() syscall.
20638e7d8381SVivek Goyal
20648e7d8381SVivek Goyalconfig KEXEC_BZIMAGE_VERIFY_SIG
20658e7d8381SVivek Goyal	bool "Enable bzImage signature verification support"
206699d5cadfSJiri Bohac	depends on KEXEC_SIG
20678e7d8381SVivek Goyal	depends on SIGNED_PE_FILE_VERIFICATION
20688e7d8381SVivek Goyal	select SYSTEM_TRUSTED_KEYRING
20698e7d8381SVivek Goyal	---help---
20708e7d8381SVivek Goyal	  Enable bzImage signature verification support.
20718e7d8381SVivek Goyal
2072506f1d07SSam Ravnborgconfig CRASH_DUMP
207304b69447SPavel Machek	bool "kernel crash dumps"
2074506f1d07SSam Ravnborg	depends on X86_64 || (X86_32 && HIGHMEM)
20758f9ca475SIngo Molnar	---help---
2076506f1d07SSam Ravnborg	  Generate crash dump after being started by kexec.
2077506f1d07SSam Ravnborg	  This should be normally only set in special crash dump kernels
2078506f1d07SSam Ravnborg	  which are loaded in the main kernel with kexec-tools into
2079506f1d07SSam Ravnborg	  a specially reserved region and then later executed after
2080506f1d07SSam Ravnborg	  a crash by kdump/kexec. The crash dump kernel must be compiled
2081506f1d07SSam Ravnborg	  to a memory address not used by the main kernel or BIOS using
2082506f1d07SSam Ravnborg	  PHYSICAL_START, or it must be built as a relocatable image
2083506f1d07SSam Ravnborg	  (CONFIG_RELOCATABLE=y).
2084330d4810SMauro Carvalho Chehab	  For more details see Documentation/admin-guide/kdump/kdump.rst
2085506f1d07SSam Ravnborg
20863ab83521SHuang Yingconfig KEXEC_JUMP
20876ea30386SKees Cook	bool "kexec jump"
2088fee7b0d8SHuang Ying	depends on KEXEC && HIBERNATION
20898f9ca475SIngo Molnar	---help---
209089081d17SHuang Ying	  Jump between original kernel and kexeced kernel and invoke
209189081d17SHuang Ying	  code in physical address mode via KEXEC
20923ab83521SHuang Ying
2093506f1d07SSam Ravnborgconfig PHYSICAL_START
20946a108a14SDavid Rientjes	hex "Physical address where the kernel is loaded" if (EXPERT || CRASH_DUMP)
2095ceefccc9SH. Peter Anvin	default "0x1000000"
20968f9ca475SIngo Molnar	---help---
2097506f1d07SSam Ravnborg	  This gives the physical address where the kernel is loaded.
2098506f1d07SSam Ravnborg
2099506f1d07SSam Ravnborg	  If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then
2100506f1d07SSam Ravnborg	  bzImage will decompress itself to above physical address and
2101506f1d07SSam Ravnborg	  run from there. Otherwise, bzImage will run from the address where
2102506f1d07SSam Ravnborg	  it has been loaded by the boot loader and will ignore above physical
2103506f1d07SSam Ravnborg	  address.
2104506f1d07SSam Ravnborg
2105506f1d07SSam Ravnborg	  In normal kdump cases one does not have to set/change this option
2106506f1d07SSam Ravnborg	  as now bzImage can be compiled as a completely relocatable image
2107506f1d07SSam Ravnborg	  (CONFIG_RELOCATABLE=y) and be used to load and run from a different
2108506f1d07SSam Ravnborg	  address. This option is mainly useful for the folks who don't want
2109506f1d07SSam Ravnborg	  to use a bzImage for capturing the crash dump and want to use a
2110506f1d07SSam Ravnborg	  vmlinux instead. vmlinux is not relocatable hence a kernel needs
2111506f1d07SSam Ravnborg	  to be specifically compiled to run from a specific memory area
2112506f1d07SSam Ravnborg	  (normally a reserved region) and this option comes handy.
2113506f1d07SSam Ravnborg
2114ceefccc9SH. Peter Anvin	  So if you are using bzImage for capturing the crash dump,
2115ceefccc9SH. Peter Anvin	  leave the value here unchanged to 0x1000000 and set
2116ceefccc9SH. Peter Anvin	  CONFIG_RELOCATABLE=y.  Otherwise if you plan to use vmlinux
2117ceefccc9SH. Peter Anvin	  for capturing the crash dump change this value to start of
2118ceefccc9SH. Peter Anvin	  the reserved region.  In other words, it can be set based on
2119ceefccc9SH. Peter Anvin	  the "X" value as specified in the "crashkernel=YM@XM"
2120ceefccc9SH. Peter Anvin	  command line boot parameter passed to the panic-ed
2121330d4810SMauro Carvalho Chehab	  kernel. Please take a look at Documentation/admin-guide/kdump/kdump.rst
2122ceefccc9SH. Peter Anvin	  for more details about crash dumps.
2123506f1d07SSam Ravnborg
2124506f1d07SSam Ravnborg	  Usage of bzImage for capturing the crash dump is recommended as
2125506f1d07SSam Ravnborg	  one does not have to build two kernels. Same kernel can be used
2126506f1d07SSam Ravnborg	  as production kernel and capture kernel. Above option should have
2127506f1d07SSam Ravnborg	  gone away after relocatable bzImage support is introduced. But it
2128506f1d07SSam Ravnborg	  is present because there are users out there who continue to use
2129506f1d07SSam Ravnborg	  vmlinux for dump capture. This option should go away down the
2130506f1d07SSam Ravnborg	  line.
2131506f1d07SSam Ravnborg
2132506f1d07SSam Ravnborg	  Don't change this unless you know what you are doing.
2133506f1d07SSam Ravnborg
2134506f1d07SSam Ravnborgconfig RELOCATABLE
213526717808SH. Peter Anvin	bool "Build a relocatable kernel"
213626717808SH. Peter Anvin	default y
21378f9ca475SIngo Molnar	---help---
2138506f1d07SSam Ravnborg	  This builds a kernel image that retains relocation information
2139506f1d07SSam Ravnborg	  so it can be loaded someplace besides the default 1MB.
2140506f1d07SSam Ravnborg	  The relocations tend to make the kernel binary about 10% larger,
2141506f1d07SSam Ravnborg	  but are discarded at runtime.
2142506f1d07SSam Ravnborg
2143506f1d07SSam Ravnborg	  One use is for the kexec on panic case where the recovery kernel
2144506f1d07SSam Ravnborg	  must live at a different physical address than the primary
2145506f1d07SSam Ravnborg	  kernel.
2146506f1d07SSam Ravnborg
2147506f1d07SSam Ravnborg	  Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address
2148506f1d07SSam Ravnborg	  it has been loaded at and the compile time physical address
21498ab3820fSKees Cook	  (CONFIG_PHYSICAL_START) is used as the minimum location.
2150506f1d07SSam Ravnborg
21518ab3820fSKees Cookconfig RANDOMIZE_BASE
2152e8581e3dSBaoquan He	bool "Randomize the address of the kernel image (KASLR)"
21538ab3820fSKees Cook	depends on RELOCATABLE
21546807c846SIngo Molnar	default y
21558ab3820fSKees Cook	---help---
2156e8581e3dSBaoquan He	  In support of Kernel Address Space Layout Randomization (KASLR),
2157e8581e3dSBaoquan He	  this randomizes the physical address at which the kernel image
2158e8581e3dSBaoquan He	  is decompressed and the virtual address where the kernel
2159e8581e3dSBaoquan He	  image is mapped, as a security feature that deters exploit
2160e8581e3dSBaoquan He	  attempts relying on knowledge of the location of kernel
2161e8581e3dSBaoquan He	  code internals.
2162e8581e3dSBaoquan He
2163ed9f007eSKees Cook	  On 64-bit, the kernel physical and virtual addresses are
2164ed9f007eSKees Cook	  randomized separately. The physical address will be anywhere
2165ed9f007eSKees Cook	  between 16MB and the top of physical memory (up to 64TB). The
2166ed9f007eSKees Cook	  virtual address will be randomized from 16MB up to 1GB (9 bits
2167ed9f007eSKees Cook	  of entropy). Note that this also reduces the memory space
2168ed9f007eSKees Cook	  available to kernel modules from 1.5GB to 1GB.
2169ed9f007eSKees Cook
2170ed9f007eSKees Cook	  On 32-bit, the kernel physical and virtual addresses are
2171ed9f007eSKees Cook	  randomized together. They will be randomized from 16MB up to
2172ed9f007eSKees Cook	  512MB (8 bits of entropy).
21738ab3820fSKees Cook
2174a653f356SKees Cook	  Entropy is generated using the RDRAND instruction if it is
2175e8581e3dSBaoquan He	  supported. If RDTSC is supported, its value is mixed into
2176e8581e3dSBaoquan He	  the entropy pool as well. If neither RDRAND nor RDTSC are
2177ed9f007eSKees Cook	  supported, then entropy is read from the i8254 timer. The
2178ed9f007eSKees Cook	  usable entropy is limited by the kernel being built using
2179ed9f007eSKees Cook	  2GB addressing, and that PHYSICAL_ALIGN must be at a
2180ed9f007eSKees Cook	  minimum of 2MB. As a result, only 10 bits of entropy are
2181ed9f007eSKees Cook	  theoretically possible, but the implementations are further
2182ed9f007eSKees Cook	  limited due to memory layouts.
2183e8581e3dSBaoquan He
21846807c846SIngo Molnar	  If unsure, say Y.
2185da2b6fb9SKees Cook
21868ab3820fSKees Cook# Relocation on x86 needs some additional build support
2187845adf72SH. Peter Anvinconfig X86_NEED_RELOCS
2188845adf72SH. Peter Anvin	def_bool y
21898ab3820fSKees Cook	depends on RANDOMIZE_BASE || (X86_32 && RELOCATABLE)
2190845adf72SH. Peter Anvin
2191506f1d07SSam Ravnborgconfig PHYSICAL_ALIGN
2192a0215061SKees Cook	hex "Alignment value to which kernel should be aligned"
21938ab3820fSKees Cook	default "0x200000"
2194a0215061SKees Cook	range 0x2000 0x1000000 if X86_32
2195a0215061SKees Cook	range 0x200000 0x1000000 if X86_64
21968f9ca475SIngo Molnar	---help---
2197506f1d07SSam Ravnborg	  This value puts the alignment restrictions on physical address
2198506f1d07SSam Ravnborg	  where kernel is loaded and run from. Kernel is compiled for an
2199506f1d07SSam Ravnborg	  address which meets above alignment restriction.
2200506f1d07SSam Ravnborg
2201506f1d07SSam Ravnborg	  If bootloader loads the kernel at a non-aligned address and
2202506f1d07SSam Ravnborg	  CONFIG_RELOCATABLE is set, kernel will move itself to nearest
2203506f1d07SSam Ravnborg	  address aligned to above value and run from there.
2204506f1d07SSam Ravnborg
2205506f1d07SSam Ravnborg	  If bootloader loads the kernel at a non-aligned address and
2206506f1d07SSam Ravnborg	  CONFIG_RELOCATABLE is not set, kernel will ignore the run time
2207506f1d07SSam Ravnborg	  load address and decompress itself to the address it has been
2208506f1d07SSam Ravnborg	  compiled for and run from there. The address for which kernel is
2209506f1d07SSam Ravnborg	  compiled already meets above alignment restrictions. Hence the
2210506f1d07SSam Ravnborg	  end result is that kernel runs from a physical address meeting
2211506f1d07SSam Ravnborg	  above alignment restrictions.
2212506f1d07SSam Ravnborg
2213a0215061SKees Cook	  On 32-bit this value must be a multiple of 0x2000. On 64-bit
2214a0215061SKees Cook	  this value must be a multiple of 0x200000.
2215a0215061SKees Cook
2216506f1d07SSam Ravnborg	  Don't change this unless you know what you are doing.
2217506f1d07SSam Ravnborg
2218eedb92abSKirill A. Shutemovconfig DYNAMIC_MEMORY_LAYOUT
2219eedb92abSKirill A. Shutemov	bool
2220eedb92abSKirill A. Shutemov	---help---
2221eedb92abSKirill A. Shutemov	  This option makes base addresses of vmalloc and vmemmap as well as
2222eedb92abSKirill A. Shutemov	  __PAGE_OFFSET movable during boot.
2223eedb92abSKirill A. Shutemov
22240483e1faSThomas Garnierconfig RANDOMIZE_MEMORY
22250483e1faSThomas Garnier	bool "Randomize the kernel memory sections"
22260483e1faSThomas Garnier	depends on X86_64
22270483e1faSThomas Garnier	depends on RANDOMIZE_BASE
2228eedb92abSKirill A. Shutemov	select DYNAMIC_MEMORY_LAYOUT
22290483e1faSThomas Garnier	default RANDOMIZE_BASE
22300483e1faSThomas Garnier	---help---
22310483e1faSThomas Garnier	   Randomizes the base virtual address of kernel memory sections
22320483e1faSThomas Garnier	   (physical memory mapping, vmalloc & vmemmap). This security feature
22330483e1faSThomas Garnier	   makes exploits relying on predictable memory locations less reliable.
22340483e1faSThomas Garnier
22350483e1faSThomas Garnier	   The order of allocations remains unchanged. Entropy is generated in
22360483e1faSThomas Garnier	   the same way as RANDOMIZE_BASE. Current implementation in the optimal
22370483e1faSThomas Garnier	   configuration have in average 30,000 different possible virtual
22380483e1faSThomas Garnier	   addresses for each memory section.
22390483e1faSThomas Garnier
22406807c846SIngo Molnar	   If unsure, say Y.
22410483e1faSThomas Garnier
224290397a41SThomas Garnierconfig RANDOMIZE_MEMORY_PHYSICAL_PADDING
224390397a41SThomas Garnier	hex "Physical memory mapping padding" if EXPERT
224490397a41SThomas Garnier	depends on RANDOMIZE_MEMORY
224590397a41SThomas Garnier	default "0xa" if MEMORY_HOTPLUG
224690397a41SThomas Garnier	default "0x0"
224790397a41SThomas Garnier	range 0x1 0x40 if MEMORY_HOTPLUG
224890397a41SThomas Garnier	range 0x0 0x40
224990397a41SThomas Garnier	---help---
225090397a41SThomas Garnier	   Define the padding in terabytes added to the existing physical
225190397a41SThomas Garnier	   memory size during kernel memory randomization. It is useful
225290397a41SThomas Garnier	   for memory hotplug support but reduces the entropy available for
225390397a41SThomas Garnier	   address randomization.
225490397a41SThomas Garnier
225590397a41SThomas Garnier	   If unsure, leave at the default value.
225690397a41SThomas Garnier
2257506f1d07SSam Ravnborgconfig HOTPLUG_CPU
2258bebd024eSThomas Gleixner	def_bool y
225940b31360SStephen Rothwell	depends on SMP
2260506f1d07SSam Ravnborg
226180aa1dffSFenghua Yuconfig BOOTPARAM_HOTPLUG_CPU0
226280aa1dffSFenghua Yu	bool "Set default setting of cpu0_hotpluggable"
22632c922cd0SKees Cook	depends on HOTPLUG_CPU
226480aa1dffSFenghua Yu	---help---
226580aa1dffSFenghua Yu	  Set whether default state of cpu0_hotpluggable is on or off.
226680aa1dffSFenghua Yu
226780aa1dffSFenghua Yu	  Say Y here to enable CPU0 hotplug by default. If this switch
226880aa1dffSFenghua Yu	  is turned on, there is no need to give cpu0_hotplug kernel
226980aa1dffSFenghua Yu	  parameter and the CPU0 hotplug feature is enabled by default.
227080aa1dffSFenghua Yu
227180aa1dffSFenghua Yu	  Please note: there are two known CPU0 dependencies if you want
227280aa1dffSFenghua Yu	  to enable the CPU0 hotplug feature either by this switch or by
227380aa1dffSFenghua Yu	  cpu0_hotplug kernel parameter.
227480aa1dffSFenghua Yu
227580aa1dffSFenghua Yu	  First, resume from hibernate or suspend always starts from CPU0.
227680aa1dffSFenghua Yu	  So hibernate and suspend are prevented if CPU0 is offline.
227780aa1dffSFenghua Yu
227880aa1dffSFenghua Yu	  Second dependency is PIC interrupts always go to CPU0. CPU0 can not
227980aa1dffSFenghua Yu	  offline if any interrupt can not migrate out of CPU0. There may
228080aa1dffSFenghua Yu	  be other CPU0 dependencies.
228180aa1dffSFenghua Yu
228280aa1dffSFenghua Yu	  Please make sure the dependencies are under your control before
228380aa1dffSFenghua Yu	  you enable this feature.
228480aa1dffSFenghua Yu
228580aa1dffSFenghua Yu	  Say N if you don't want to enable CPU0 hotplug feature by default.
228680aa1dffSFenghua Yu	  You still can enable the CPU0 hotplug feature at boot by kernel
228780aa1dffSFenghua Yu	  parameter cpu0_hotplug.
228880aa1dffSFenghua Yu
2289a71c8bc5SFenghua Yuconfig DEBUG_HOTPLUG_CPU0
2290a71c8bc5SFenghua Yu	def_bool n
2291a71c8bc5SFenghua Yu	prompt "Debug CPU0 hotplug"
22922c922cd0SKees Cook	depends on HOTPLUG_CPU
2293a71c8bc5SFenghua Yu	---help---
2294a71c8bc5SFenghua Yu	  Enabling this option offlines CPU0 (if CPU0 can be offlined) as
2295a71c8bc5SFenghua Yu	  soon as possible and boots up userspace with CPU0 offlined. User
2296a71c8bc5SFenghua Yu	  can online CPU0 back after boot time.
2297a71c8bc5SFenghua Yu
2298a71c8bc5SFenghua Yu	  To debug CPU0 hotplug, you need to enable CPU0 offline/online
2299a71c8bc5SFenghua Yu	  feature by either turning on CONFIG_BOOTPARAM_HOTPLUG_CPU0 during
2300a71c8bc5SFenghua Yu	  compilation or giving cpu0_hotplug kernel parameter at boot.
2301a71c8bc5SFenghua Yu
2302a71c8bc5SFenghua Yu	  If unsure, say N.
2303a71c8bc5SFenghua Yu
2304506f1d07SSam Ravnborgconfig COMPAT_VDSO
2305b0b49f26SAndy Lutomirski	def_bool n
2306b0b49f26SAndy Lutomirski	prompt "Disable the 32-bit vDSO (needed for glibc 2.3.3)"
2307953fee1dSIngo Molnar	depends on COMPAT_32
23088f9ca475SIngo Molnar	---help---
2309b0b49f26SAndy Lutomirski	  Certain buggy versions of glibc will crash if they are
2310b0b49f26SAndy Lutomirski	  presented with a 32-bit vDSO that is not mapped at the address
2311b0b49f26SAndy Lutomirski	  indicated in its segment table.
2312e84446deSRandy Dunlap
2313b0b49f26SAndy Lutomirski	  The bug was introduced by f866314b89d56845f55e6f365e18b31ec978ec3a
2314b0b49f26SAndy Lutomirski	  and fixed by 3b3ddb4f7db98ec9e912ccdf54d35df4aa30e04a and
2315b0b49f26SAndy Lutomirski	  49ad572a70b8aeb91e57483a11dd1b77e31c4468.  Glibc 2.3.3 is
2316b0b49f26SAndy Lutomirski	  the only released version with the bug, but OpenSUSE 9
2317b0b49f26SAndy Lutomirski	  contains a buggy "glibc 2.3.2".
2318506f1d07SSam Ravnborg
2319b0b49f26SAndy Lutomirski	  The symptom of the bug is that everything crashes on startup, saying:
2320b0b49f26SAndy Lutomirski	  dl_main: Assertion `(void *) ph->p_vaddr == _rtld_local._dl_sysinfo_dso' failed!
2321b0b49f26SAndy Lutomirski
2322b0b49f26SAndy Lutomirski	  Saying Y here changes the default value of the vdso32 boot
2323b0b49f26SAndy Lutomirski	  option from 1 to 0, which turns off the 32-bit vDSO entirely.
2324b0b49f26SAndy Lutomirski	  This works around the glibc bug but hurts performance.
2325b0b49f26SAndy Lutomirski
2326b0b49f26SAndy Lutomirski	  If unsure, say N: if you are compiling your own kernel, you
2327b0b49f26SAndy Lutomirski	  are unlikely to be using a buggy version of glibc.
2328506f1d07SSam Ravnborg
23293dc33bd3SKees Cookchoice
23303dc33bd3SKees Cook	prompt "vsyscall table for legacy applications"
23313dc33bd3SKees Cook	depends on X86_64
2332625b7b7fSAndy Lutomirski	default LEGACY_VSYSCALL_XONLY
23333dc33bd3SKees Cook	help
23343dc33bd3SKees Cook	  Legacy user code that does not know how to find the vDSO expects
23353dc33bd3SKees Cook	  to be able to issue three syscalls by calling fixed addresses in
23363dc33bd3SKees Cook	  kernel space. Since this location is not randomized with ASLR,
23373dc33bd3SKees Cook	  it can be used to assist security vulnerability exploitation.
23383dc33bd3SKees Cook
23393dc33bd3SKees Cook	  This setting can be changed at boot time via the kernel command
2340bd49e16eSAndy Lutomirski	  line parameter vsyscall=[emulate|xonly|none].
23413dc33bd3SKees Cook
23423dc33bd3SKees Cook	  On a system with recent enough glibc (2.14 or newer) and no
23433dc33bd3SKees Cook	  static binaries, you can say None without a performance penalty
23443dc33bd3SKees Cook	  to improve security.
23453dc33bd3SKees Cook
2346bd49e16eSAndy Lutomirski	  If unsure, select "Emulate execution only".
23473dc33bd3SKees Cook
23483dc33bd3SKees Cook	config LEGACY_VSYSCALL_EMULATE
2349bd49e16eSAndy Lutomirski		bool "Full emulation"
23503dc33bd3SKees Cook		help
2351bd49e16eSAndy Lutomirski		  The kernel traps and emulates calls into the fixed vsyscall
2352bd49e16eSAndy Lutomirski		  address mapping. This makes the mapping non-executable, but
2353bd49e16eSAndy Lutomirski		  it still contains readable known contents, which could be
2354bd49e16eSAndy Lutomirski		  used in certain rare security vulnerability exploits. This
2355bd49e16eSAndy Lutomirski		  configuration is recommended when using legacy userspace
2356bd49e16eSAndy Lutomirski		  that still uses vsyscalls along with legacy binary
2357bd49e16eSAndy Lutomirski		  instrumentation tools that require code to be readable.
2358bd49e16eSAndy Lutomirski
2359bd49e16eSAndy Lutomirski		  An example of this type of legacy userspace is running
2360bd49e16eSAndy Lutomirski		  Pin on an old binary that still uses vsyscalls.
2361bd49e16eSAndy Lutomirski
2362bd49e16eSAndy Lutomirski	config LEGACY_VSYSCALL_XONLY
2363bd49e16eSAndy Lutomirski		bool "Emulate execution only"
2364bd49e16eSAndy Lutomirski		help
2365bd49e16eSAndy Lutomirski		  The kernel traps and emulates calls into the fixed vsyscall
2366bd49e16eSAndy Lutomirski		  address mapping and does not allow reads.  This
2367bd49e16eSAndy Lutomirski		  configuration is recommended when userspace might use the
2368bd49e16eSAndy Lutomirski		  legacy vsyscall area but support for legacy binary
2369bd49e16eSAndy Lutomirski		  instrumentation of legacy code is not needed.  It mitigates
2370bd49e16eSAndy Lutomirski		  certain uses of the vsyscall area as an ASLR-bypassing
2371bd49e16eSAndy Lutomirski		  buffer.
23723dc33bd3SKees Cook
23733dc33bd3SKees Cook	config LEGACY_VSYSCALL_NONE
23743dc33bd3SKees Cook		bool "None"
23753dc33bd3SKees Cook		help
23763dc33bd3SKees Cook		  There will be no vsyscall mapping at all. This will
23773dc33bd3SKees Cook		  eliminate any risk of ASLR bypass due to the vsyscall
23783dc33bd3SKees Cook		  fixed address mapping. Attempts to use the vsyscalls
23793dc33bd3SKees Cook		  will be reported to dmesg, so that either old or
23803dc33bd3SKees Cook		  malicious userspace programs can be identified.
23813dc33bd3SKees Cook
23823dc33bd3SKees Cookendchoice
23833dc33bd3SKees Cook
2384516cbf37STim Birdconfig CMDLINE_BOOL
2385516cbf37STim Bird	bool "Built-in kernel command line"
23868f9ca475SIngo Molnar	---help---
2387516cbf37STim Bird	  Allow for specifying boot arguments to the kernel at
2388516cbf37STim Bird	  build time.  On some systems (e.g. embedded ones), it is
2389516cbf37STim Bird	  necessary or convenient to provide some or all of the
2390516cbf37STim Bird	  kernel boot arguments with the kernel itself (that is,
2391516cbf37STim Bird	  to not rely on the boot loader to provide them.)
2392516cbf37STim Bird
2393516cbf37STim Bird	  To compile command line arguments into the kernel,
2394516cbf37STim Bird	  set this option to 'Y', then fill in the
239569711ca1SSébastien Hinderer	  boot arguments in CONFIG_CMDLINE.
2396516cbf37STim Bird
2397516cbf37STim Bird	  Systems with fully functional boot loaders (i.e. non-embedded)
2398516cbf37STim Bird	  should leave this option set to 'N'.
2399516cbf37STim Bird
2400516cbf37STim Birdconfig CMDLINE
2401516cbf37STim Bird	string "Built-in kernel command string"
2402516cbf37STim Bird	depends on CMDLINE_BOOL
2403516cbf37STim Bird	default ""
24048f9ca475SIngo Molnar	---help---
2405516cbf37STim Bird	  Enter arguments here that should be compiled into the kernel
2406516cbf37STim Bird	  image and used at boot time.  If the boot loader provides a
2407516cbf37STim Bird	  command line at boot time, it is appended to this string to
2408516cbf37STim Bird	  form the full kernel command line, when the system boots.
2409516cbf37STim Bird
2410516cbf37STim Bird	  However, you can use the CONFIG_CMDLINE_OVERRIDE option to
2411516cbf37STim Bird	  change this behavior.
2412516cbf37STim Bird
2413516cbf37STim Bird	  In most cases, the command line (whether built-in or provided
2414516cbf37STim Bird	  by the boot loader) should specify the device for the root
2415516cbf37STim Bird	  file system.
2416516cbf37STim Bird
2417516cbf37STim Birdconfig CMDLINE_OVERRIDE
2418516cbf37STim Bird	bool "Built-in command line overrides boot loader arguments"
2419645e6466SAnders Roxell	depends on CMDLINE_BOOL && CMDLINE != ""
24208f9ca475SIngo Molnar	---help---
2421516cbf37STim Bird	  Set this option to 'Y' to have the kernel ignore the boot loader
2422516cbf37STim Bird	  command line, and use ONLY the built-in command line.
2423516cbf37STim Bird
2424516cbf37STim Bird	  This is used to work around broken boot loaders.  This should
2425516cbf37STim Bird	  be set to 'N' under normal conditions.
2426516cbf37STim Bird
2427a5b9e5a2SAndy Lutomirskiconfig MODIFY_LDT_SYSCALL
2428a5b9e5a2SAndy Lutomirski	bool "Enable the LDT (local descriptor table)" if EXPERT
2429a5b9e5a2SAndy Lutomirski	default y
2430a5b9e5a2SAndy Lutomirski	---help---
2431a5b9e5a2SAndy Lutomirski	  Linux can allow user programs to install a per-process x86
2432a5b9e5a2SAndy Lutomirski	  Local Descriptor Table (LDT) using the modify_ldt(2) system
2433a5b9e5a2SAndy Lutomirski	  call.  This is required to run 16-bit or segmented code such as
2434a5b9e5a2SAndy Lutomirski	  DOSEMU or some Wine programs.  It is also used by some very old
2435a5b9e5a2SAndy Lutomirski	  threading libraries.
2436a5b9e5a2SAndy Lutomirski
2437a5b9e5a2SAndy Lutomirski	  Enabling this feature adds a small amount of overhead to
2438a5b9e5a2SAndy Lutomirski	  context switches and increases the low-level kernel attack
2439a5b9e5a2SAndy Lutomirski	  surface.  Disabling it removes the modify_ldt(2) system call.
2440a5b9e5a2SAndy Lutomirski
2441a5b9e5a2SAndy Lutomirski	  Saying 'N' here may make sense for embedded or server kernels.
2442a5b9e5a2SAndy Lutomirski
2443b700e7f0SSeth Jenningssource "kernel/livepatch/Kconfig"
2444b700e7f0SSeth Jennings
2445506f1d07SSam Ravnborgendmenu
2446506f1d07SSam Ravnborg
24473072e413SMichal Hockoconfig ARCH_HAS_ADD_PAGES
24483072e413SMichal Hocko	def_bool y
24493072e413SMichal Hocko	depends on X86_64 && ARCH_ENABLE_MEMORY_HOTPLUG
24503072e413SMichal Hocko
2451506f1d07SSam Ravnborgconfig ARCH_ENABLE_MEMORY_HOTPLUG
2452506f1d07SSam Ravnborg	def_bool y
2453506f1d07SSam Ravnborg	depends on X86_64 || (X86_32 && HIGHMEM)
2454506f1d07SSam Ravnborg
245535551053SGary Hadeconfig ARCH_ENABLE_MEMORY_HOTREMOVE
245635551053SGary Hade	def_bool y
245735551053SGary Hade	depends on MEMORY_HOTPLUG
245835551053SGary Hade
2459e534c7c5SLee Schermerhornconfig USE_PERCPU_NUMA_NODE_ID
2460645a7919STejun Heo	def_bool y
2461e534c7c5SLee Schermerhorn	depends on NUMA
2462e534c7c5SLee Schermerhorn
24639491846fSKirill A. Shutemovconfig ARCH_ENABLE_SPLIT_PMD_PTLOCK
24649491846fSKirill A. Shutemov	def_bool y
24659491846fSKirill A. Shutemov	depends on X86_64 || X86_PAE
24669491846fSKirill A. Shutemov
2467c177c81eSNaoya Horiguchiconfig ARCH_ENABLE_HUGEPAGE_MIGRATION
2468c177c81eSNaoya Horiguchi	def_bool y
2469c177c81eSNaoya Horiguchi	depends on X86_64 && HUGETLB_PAGE && MIGRATION
2470c177c81eSNaoya Horiguchi
24719c670ea3SNaoya Horiguchiconfig ARCH_ENABLE_THP_MIGRATION
24729c670ea3SNaoya Horiguchi	def_bool y
24739c670ea3SNaoya Horiguchi	depends on X86_64 && TRANSPARENT_HUGEPAGE
24749c670ea3SNaoya Horiguchi
2475da85f865SBjorn Helgaasmenu "Power management and ACPI options"
2476e279b6c1SSam Ravnborg
2477e279b6c1SSam Ravnborgconfig ARCH_HIBERNATION_HEADER
24783c2362e6SHarvey Harrison	def_bool y
247944556530SZhimin Gu	depends on HIBERNATION
2480e279b6c1SSam Ravnborg
2481e279b6c1SSam Ravnborgsource "kernel/power/Kconfig"
2482e279b6c1SSam Ravnborg
2483e279b6c1SSam Ravnborgsource "drivers/acpi/Kconfig"
2484e279b6c1SSam Ravnborg
2485efafc8b2SFeng Tangsource "drivers/sfi/Kconfig"
2486efafc8b2SFeng Tang
2487a6b68076SAndi Kleenconfig X86_APM_BOOT
24886fc108a0SJan Beulich	def_bool y
2489282e5aabSPaul Bolle	depends on APM
2490a6b68076SAndi Kleen
2491e279b6c1SSam Ravnborgmenuconfig APM
2492e279b6c1SSam Ravnborg	tristate "APM (Advanced Power Management) BIOS support"
2493efefa6f6SIngo Molnar	depends on X86_32 && PM_SLEEP
2494e279b6c1SSam Ravnborg	---help---
2495e279b6c1SSam Ravnborg	  APM is a BIOS specification for saving power using several different
2496e279b6c1SSam Ravnborg	  techniques. This is mostly useful for battery powered laptops with
2497e279b6c1SSam Ravnborg	  APM compliant BIOSes. If you say Y here, the system time will be
2498e279b6c1SSam Ravnborg	  reset after a RESUME operation, the /proc/apm device will provide
2499e279b6c1SSam Ravnborg	  battery status information, and user-space programs will receive
2500e279b6c1SSam Ravnborg	  notification of APM "events" (e.g. battery status change).
2501e279b6c1SSam Ravnborg
2502e279b6c1SSam Ravnborg	  If you select "Y" here, you can disable actual use of the APM
2503e279b6c1SSam Ravnborg	  BIOS by passing the "apm=off" option to the kernel at boot time.
2504e279b6c1SSam Ravnborg
2505e279b6c1SSam Ravnborg	  Note that the APM support is almost completely disabled for
2506e279b6c1SSam Ravnborg	  machines with more than one CPU.
2507e279b6c1SSam Ravnborg
2508e279b6c1SSam Ravnborg	  In order to use APM, you will need supporting software. For location
2509151f4e2bSMauro Carvalho Chehab	  and more information, read <file:Documentation/power/apm-acpi.rst>
25102dc98fd3SMichael Witten	  and the Battery Powered Linux mini-HOWTO, available from
2511e279b6c1SSam Ravnborg	  <http://www.tldp.org/docs.html#howto>.
2512e279b6c1SSam Ravnborg
2513e279b6c1SSam Ravnborg	  This driver does not spin down disk drives (see the hdparm(8)
2514e279b6c1SSam Ravnborg	  manpage ("man 8 hdparm") for that), and it doesn't turn off
2515e279b6c1SSam Ravnborg	  VESA-compliant "green" monitors.
2516e279b6c1SSam Ravnborg
2517e279b6c1SSam Ravnborg	  This driver does not support the TI 4000M TravelMate and the ACER
2518e279b6c1SSam Ravnborg	  486/DX4/75 because they don't have compliant BIOSes. Many "green"
2519e279b6c1SSam Ravnborg	  desktop machines also don't have compliant BIOSes, and this driver
2520e279b6c1SSam Ravnborg	  may cause those machines to panic during the boot phase.
2521e279b6c1SSam Ravnborg
2522e279b6c1SSam Ravnborg	  Generally, if you don't have a battery in your machine, there isn't
2523e279b6c1SSam Ravnborg	  much point in using this driver and you should say N. If you get
2524e279b6c1SSam Ravnborg	  random kernel OOPSes or reboots that don't seem to be related to
2525e279b6c1SSam Ravnborg	  anything, try disabling/enabling this option (or disabling/enabling
2526e279b6c1SSam Ravnborg	  APM in your BIOS).
2527e279b6c1SSam Ravnborg
2528e279b6c1SSam Ravnborg	  Some other things you should try when experiencing seemingly random,
2529e279b6c1SSam Ravnborg	  "weird" problems:
2530e279b6c1SSam Ravnborg
2531e279b6c1SSam Ravnborg	  1) make sure that you have enough swap space and that it is
2532e279b6c1SSam Ravnborg	  enabled.
2533e279b6c1SSam Ravnborg	  2) pass the "no-hlt" option to the kernel
2534e279b6c1SSam Ravnborg	  3) switch on floating point emulation in the kernel and pass
2535e279b6c1SSam Ravnborg	  the "no387" option to the kernel
2536e279b6c1SSam Ravnborg	  4) pass the "floppy=nodma" option to the kernel
2537e279b6c1SSam Ravnborg	  5) pass the "mem=4M" option to the kernel (thereby disabling
2538e279b6c1SSam Ravnborg	  all but the first 4 MB of RAM)
2539e279b6c1SSam Ravnborg	  6) make sure that the CPU is not over clocked.
2540e279b6c1SSam Ravnborg	  7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/>
2541e279b6c1SSam Ravnborg	  8) disable the cache from your BIOS settings
2542e279b6c1SSam Ravnborg	  9) install a fan for the video card or exchange video RAM
2543e279b6c1SSam Ravnborg	  10) install a better fan for the CPU
2544e279b6c1SSam Ravnborg	  11) exchange RAM chips
2545e279b6c1SSam Ravnborg	  12) exchange the motherboard.
2546e279b6c1SSam Ravnborg
2547e279b6c1SSam Ravnborg	  To compile this driver as a module, choose M here: the
2548e279b6c1SSam Ravnborg	  module will be called apm.
2549e279b6c1SSam Ravnborg
2550e279b6c1SSam Ravnborgif APM
2551e279b6c1SSam Ravnborg
2552e279b6c1SSam Ravnborgconfig APM_IGNORE_USER_SUSPEND
2553e279b6c1SSam Ravnborg	bool "Ignore USER SUSPEND"
25548f9ca475SIngo Molnar	---help---
2555e279b6c1SSam Ravnborg	  This option will ignore USER SUSPEND requests. On machines with a
2556e279b6c1SSam Ravnborg	  compliant APM BIOS, you want to say N. However, on the NEC Versa M
2557e279b6c1SSam Ravnborg	  series notebooks, it is necessary to say Y because of a BIOS bug.
2558e279b6c1SSam Ravnborg
2559e279b6c1SSam Ravnborgconfig APM_DO_ENABLE
2560e279b6c1SSam Ravnborg	bool "Enable PM at boot time"
2561e279b6c1SSam Ravnborg	---help---
2562e279b6c1SSam Ravnborg	  Enable APM features at boot time. From page 36 of the APM BIOS
2563e279b6c1SSam Ravnborg	  specification: "When disabled, the APM BIOS does not automatically
2564e279b6c1SSam Ravnborg	  power manage devices, enter the Standby State, enter the Suspend
2565e279b6c1SSam Ravnborg	  State, or take power saving steps in response to CPU Idle calls."
2566e279b6c1SSam Ravnborg	  This driver will make CPU Idle calls when Linux is idle (unless this
2567e279b6c1SSam Ravnborg	  feature is turned off -- see "Do CPU IDLE calls", below). This
2568e279b6c1SSam Ravnborg	  should always save battery power, but more complicated APM features
2569e279b6c1SSam Ravnborg	  will be dependent on your BIOS implementation. You may need to turn
2570e279b6c1SSam Ravnborg	  this option off if your computer hangs at boot time when using APM
2571e279b6c1SSam Ravnborg	  support, or if it beeps continuously instead of suspending. Turn
2572e279b6c1SSam Ravnborg	  this off if you have a NEC UltraLite Versa 33/C or a Toshiba
2573e279b6c1SSam Ravnborg	  T400CDT. This is off by default since most machines do fine without
2574e279b6c1SSam Ravnborg	  this feature.
2575e279b6c1SSam Ravnborg
2576e279b6c1SSam Ravnborgconfig APM_CPU_IDLE
2577dd8af076SLen Brown	depends on CPU_IDLE
2578e279b6c1SSam Ravnborg	bool "Make CPU Idle calls when idle"
25798f9ca475SIngo Molnar	---help---
2580e279b6c1SSam Ravnborg	  Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop.
2581e279b6c1SSam Ravnborg	  On some machines, this can activate improved power savings, such as
2582e279b6c1SSam Ravnborg	  a slowed CPU clock rate, when the machine is idle. These idle calls
2583e279b6c1SSam Ravnborg	  are made after the idle loop has run for some length of time (e.g.,
2584e279b6c1SSam Ravnborg	  333 mS). On some machines, this will cause a hang at boot time or
2585e279b6c1SSam Ravnborg	  whenever the CPU becomes idle. (On machines with more than one CPU,
2586e279b6c1SSam Ravnborg	  this option does nothing.)
2587e279b6c1SSam Ravnborg
2588e279b6c1SSam Ravnborgconfig APM_DISPLAY_BLANK
2589e279b6c1SSam Ravnborg	bool "Enable console blanking using APM"
25908f9ca475SIngo Molnar	---help---
2591e279b6c1SSam Ravnborg	  Enable console blanking using the APM. Some laptops can use this to
2592e279b6c1SSam Ravnborg	  turn off the LCD backlight when the screen blanker of the Linux
2593e279b6c1SSam Ravnborg	  virtual console blanks the screen. Note that this is only used by
2594e279b6c1SSam Ravnborg	  the virtual console screen blanker, and won't turn off the backlight
2595e279b6c1SSam Ravnborg	  when using the X Window system. This also doesn't have anything to
2596e279b6c1SSam Ravnborg	  do with your VESA-compliant power-saving monitor. Further, this
2597e279b6c1SSam Ravnborg	  option doesn't work for all laptops -- it might not turn off your
2598e279b6c1SSam Ravnborg	  backlight at all, or it might print a lot of errors to the console,
2599e279b6c1SSam Ravnborg	  especially if you are using gpm.
2600e279b6c1SSam Ravnborg
2601e279b6c1SSam Ravnborgconfig APM_ALLOW_INTS
2602e279b6c1SSam Ravnborg	bool "Allow interrupts during APM BIOS calls"
26038f9ca475SIngo Molnar	---help---
2604e279b6c1SSam Ravnborg	  Normally we disable external interrupts while we are making calls to
2605e279b6c1SSam Ravnborg	  the APM BIOS as a measure to lessen the effects of a badly behaving
2606e279b6c1SSam Ravnborg	  BIOS implementation.  The BIOS should reenable interrupts if it
2607e279b6c1SSam Ravnborg	  needs to.  Unfortunately, some BIOSes do not -- especially those in
2608e279b6c1SSam Ravnborg	  many of the newer IBM Thinkpads.  If you experience hangs when you
2609e279b6c1SSam Ravnborg	  suspend, try setting this to Y.  Otherwise, say N.
2610e279b6c1SSam Ravnborg
2611e279b6c1SSam Ravnborgendif # APM
2612e279b6c1SSam Ravnborg
2613bb0a56ecSDave Jonessource "drivers/cpufreq/Kconfig"
2614e279b6c1SSam Ravnborg
2615e279b6c1SSam Ravnborgsource "drivers/cpuidle/Kconfig"
2616e279b6c1SSam Ravnborg
261727471fdbSAndy Henroidsource "drivers/idle/Kconfig"
261827471fdbSAndy Henroid
2619e279b6c1SSam Ravnborgendmenu
2620e279b6c1SSam Ravnborg
2621e279b6c1SSam Ravnborg
2622e279b6c1SSam Ravnborgmenu "Bus options (PCI etc.)"
2623e279b6c1SSam Ravnborg
2624e279b6c1SSam Ravnborgchoice
2625e279b6c1SSam Ravnborg	prompt "PCI access mode"
2626efefa6f6SIngo Molnar	depends on X86_32 && PCI
2627e279b6c1SSam Ravnborg	default PCI_GOANY
2628e279b6c1SSam Ravnborg	---help---
2629e279b6c1SSam Ravnborg	  On PCI systems, the BIOS can be used to detect the PCI devices and
2630e279b6c1SSam Ravnborg	  determine their configuration. However, some old PCI motherboards
2631e279b6c1SSam Ravnborg	  have BIOS bugs and may crash if this is done. Also, some embedded
2632e279b6c1SSam Ravnborg	  PCI-based systems don't have any BIOS at all. Linux can also try to
2633e279b6c1SSam Ravnborg	  detect the PCI hardware directly without using the BIOS.
2634e279b6c1SSam Ravnborg
2635e279b6c1SSam Ravnborg	  With this option, you can specify how Linux should detect the
2636e279b6c1SSam Ravnborg	  PCI devices. If you choose "BIOS", the BIOS will be used,
2637e279b6c1SSam Ravnborg	  if you choose "Direct", the BIOS won't be used, and if you
2638e279b6c1SSam Ravnborg	  choose "MMConfig", then PCI Express MMCONFIG will be used.
2639e279b6c1SSam Ravnborg	  If you choose "Any", the kernel will try MMCONFIG, then the
2640e279b6c1SSam Ravnborg	  direct access method and falls back to the BIOS if that doesn't
2641e279b6c1SSam Ravnborg	  work. If unsure, go with the default, which is "Any".
2642e279b6c1SSam Ravnborg
2643e279b6c1SSam Ravnborgconfig PCI_GOBIOS
2644e279b6c1SSam Ravnborg	bool "BIOS"
2645e279b6c1SSam Ravnborg
2646e279b6c1SSam Ravnborgconfig PCI_GOMMCONFIG
2647e279b6c1SSam Ravnborg	bool "MMConfig"
2648e279b6c1SSam Ravnborg
2649e279b6c1SSam Ravnborgconfig PCI_GODIRECT
2650e279b6c1SSam Ravnborg	bool "Direct"
2651e279b6c1SSam Ravnborg
26523ef0e1f8SAndres Salomonconfig PCI_GOOLPC
265376fb6570SDaniel Drake	bool "OLPC XO-1"
26543ef0e1f8SAndres Salomon	depends on OLPC
26553ef0e1f8SAndres Salomon
26562bdd1b03SAndres Salomonconfig PCI_GOANY
26572bdd1b03SAndres Salomon	bool "Any"
26582bdd1b03SAndres Salomon
2659e279b6c1SSam Ravnborgendchoice
2660e279b6c1SSam Ravnborg
2661e279b6c1SSam Ravnborgconfig PCI_BIOS
26623c2362e6SHarvey Harrison	def_bool y
2663efefa6f6SIngo Molnar	depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY)
2664e279b6c1SSam Ravnborg
2665e279b6c1SSam Ravnborg# x86-64 doesn't support PCI BIOS access from long mode so always go direct.
2666e279b6c1SSam Ravnborgconfig PCI_DIRECT
26673c2362e6SHarvey Harrison	def_bool y
26680aba496fSShaohua Li	depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC || PCI_GOMMCONFIG))
2669e279b6c1SSam Ravnborg
2670e279b6c1SSam Ravnborgconfig PCI_MMCONFIG
2671b45c9f36SJan Kiszka	bool "Support mmconfig PCI config space access" if X86_64
2672b45c9f36SJan Kiszka	default y
26738364e1f8SJan Kiszka	depends on PCI && (ACPI || SFI || JAILHOUSE_GUEST)
2674b45c9f36SJan Kiszka	depends on X86_64 || (PCI_GOANY || PCI_GOMMCONFIG)
2675e279b6c1SSam Ravnborg
26763ef0e1f8SAndres Salomonconfig PCI_OLPC
26772bdd1b03SAndres Salomon	def_bool y
26782bdd1b03SAndres Salomon	depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY)
26793ef0e1f8SAndres Salomon
2680b5401a96SAlex Nixonconfig PCI_XEN
2681b5401a96SAlex Nixon	def_bool y
2682b5401a96SAlex Nixon	depends on PCI && XEN
2683b5401a96SAlex Nixon	select SWIOTLB_XEN
2684b5401a96SAlex Nixon
26858364e1f8SJan Kiszkaconfig MMCONF_FAM10H
26868364e1f8SJan Kiszka	def_bool y
26878364e1f8SJan Kiszka	depends on X86_64 && PCI_MMCONFIG && ACPI
2688e279b6c1SSam Ravnborg
26893f6ea84aSIra W. Snyderconfig PCI_CNB20LE_QUIRK
26906a108a14SDavid Rientjes	bool "Read CNB20LE Host Bridge Windows" if EXPERT
26916ea30386SKees Cook	depends on PCI
26923f6ea84aSIra W. Snyder	help
26933f6ea84aSIra W. Snyder	  Read the PCI windows out of the CNB20LE host bridge. This allows
26943f6ea84aSIra W. Snyder	  PCI hotplug to work on systems with the CNB20LE chipset which do
26953f6ea84aSIra W. Snyder	  not have ACPI.
26963f6ea84aSIra W. Snyder
269764a5fed6SBjorn Helgaas	  There's no public spec for this chipset, and this functionality
269864a5fed6SBjorn Helgaas	  is known to be incomplete.
269964a5fed6SBjorn Helgaas
270064a5fed6SBjorn Helgaas	  You should say N unless you know you need this.
270164a5fed6SBjorn Helgaas
27023a495511SWilliam Breathitt Grayconfig ISA_BUS
270317a2a129SWilliam Breathitt Gray	bool "ISA bus support on modern systems" if EXPERT
27043a495511SWilliam Breathitt Gray	help
270517a2a129SWilliam Breathitt Gray	  Expose ISA bus device drivers and options available for selection and
270617a2a129SWilliam Breathitt Gray	  configuration. Enable this option if your target machine has an ISA
270717a2a129SWilliam Breathitt Gray	  bus. ISA is an older system, displaced by PCI and newer bus
270817a2a129SWilliam Breathitt Gray	  architectures -- if your target machine is modern, it probably does
270917a2a129SWilliam Breathitt Gray	  not have an ISA bus.
27103a495511SWilliam Breathitt Gray
27113a495511SWilliam Breathitt Gray	  If unsure, say N.
27123a495511SWilliam Breathitt Gray
27131c00f016SDavid Rientjes# x86_64 have no ISA slots, but can have ISA-style DMA.
2714e279b6c1SSam Ravnborgconfig ISA_DMA_API
27151c00f016SDavid Rientjes	bool "ISA-style DMA support" if (X86_64 && EXPERT)
27161c00f016SDavid Rientjes	default y
27171c00f016SDavid Rientjes	help
27181c00f016SDavid Rientjes	  Enables ISA-style DMA support for devices requiring such controllers.
27191c00f016SDavid Rientjes	  If unsure, say Y.
2720e279b6c1SSam Ravnborg
272151e68d05SLinus Torvaldsif X86_32
272251e68d05SLinus Torvalds
2723e279b6c1SSam Ravnborgconfig ISA
2724e279b6c1SSam Ravnborg	bool "ISA support"
27258f9ca475SIngo Molnar	---help---
2726e279b6c1SSam Ravnborg	  Find out whether you have ISA slots on your motherboard.  ISA is the
2727e279b6c1SSam Ravnborg	  name of a bus system, i.e. the way the CPU talks to the other stuff
2728e279b6c1SSam Ravnborg	  inside your box.  Other bus systems are PCI, EISA, MicroChannel
2729e279b6c1SSam Ravnborg	  (MCA) or VESA.  ISA is an older system, now being displaced by PCI;
2730e279b6c1SSam Ravnborg	  newer boards don't support it.  If you have ISA, say Y, otherwise N.
2731e279b6c1SSam Ravnborg
2732e279b6c1SSam Ravnborgconfig SCx200
2733e279b6c1SSam Ravnborg	tristate "NatSemi SCx200 support"
27348f9ca475SIngo Molnar	---help---
2735e279b6c1SSam Ravnborg	  This provides basic support for National Semiconductor's
2736e279b6c1SSam Ravnborg	  (now AMD's) Geode processors.  The driver probes for the
2737e279b6c1SSam Ravnborg	  PCI-IDs of several on-chip devices, so its a good dependency
2738e279b6c1SSam Ravnborg	  for other scx200_* drivers.
2739e279b6c1SSam Ravnborg
2740e279b6c1SSam Ravnborg	  If compiled as a module, the driver is named scx200.
2741e279b6c1SSam Ravnborg
2742e279b6c1SSam Ravnborgconfig SCx200HR_TIMER
2743e279b6c1SSam Ravnborg	tristate "NatSemi SCx200 27MHz High-Resolution Timer Support"
2744592913ecSJohn Stultz	depends on SCx200
2745e279b6c1SSam Ravnborg	default y
27468f9ca475SIngo Molnar	---help---
2747e279b6c1SSam Ravnborg	  This driver provides a clocksource built upon the on-chip
2748e279b6c1SSam Ravnborg	  27MHz high-resolution timer.  Its also a workaround for
2749e279b6c1SSam Ravnborg	  NSC Geode SC-1100's buggy TSC, which loses time when the
2750e279b6c1SSam Ravnborg	  processor goes idle (as is done by the scheduler).  The
2751e279b6c1SSam Ravnborg	  other workaround is idle=poll boot option.
2752e279b6c1SSam Ravnborg
27533ef0e1f8SAndres Salomonconfig OLPC
27543ef0e1f8SAndres Salomon	bool "One Laptop Per Child support"
275554008979SThomas Gleixner	depends on !X86_PAE
27563c554946SAndres Salomon	select GPIOLIB
2757dc3119e7SThomas Gleixner	select OF
275845bb1674SDaniel Drake	select OF_PROMTREE
2759b4e51854SGrant Likely	select IRQ_DOMAIN
27600c3d931bSLubomir Rintel	select OLPC_EC
27618f9ca475SIngo Molnar	---help---
27623ef0e1f8SAndres Salomon	  Add support for detecting the unique features of the OLPC
27633ef0e1f8SAndres Salomon	  XO hardware.
27643ef0e1f8SAndres Salomon
2765a3128588SDaniel Drakeconfig OLPC_XO1_PM
2766a3128588SDaniel Drake	bool "OLPC XO-1 Power Management"
2767fa112cf1SBorislav Petkov	depends on OLPC && MFD_CS5535=y && PM_SLEEP
2768bf1ebf00SDaniel Drake	---help---
276997c4cb71SDaniel Drake	  Add support for poweroff and suspend of the OLPC XO-1 laptop.
2770bf1ebf00SDaniel Drake
2771cfee9597SDaniel Drakeconfig OLPC_XO1_RTC
2772cfee9597SDaniel Drake	bool "OLPC XO-1 Real Time Clock"
2773cfee9597SDaniel Drake	depends on OLPC_XO1_PM && RTC_DRV_CMOS
2774cfee9597SDaniel Drake	---help---
2775cfee9597SDaniel Drake	  Add support for the XO-1 real time clock, which can be used as a
2776cfee9597SDaniel Drake	  programmable wakeup source.
2777cfee9597SDaniel Drake
27787feda8e9SDaniel Drakeconfig OLPC_XO1_SCI
27797feda8e9SDaniel Drake	bool "OLPC XO-1 SCI extras"
278092e830f2SArnd Bergmann	depends on OLPC && OLPC_XO1_PM && GPIO_CS5535=y
2781ed8e47feSRandy Dunlap	depends on INPUT=y
2782d8d01a63SDaniel Drake	select POWER_SUPPLY
27837feda8e9SDaniel Drake	---help---
27847feda8e9SDaniel Drake	  Add support for SCI-based features of the OLPC XO-1 laptop:
27857bc74b3dSDaniel Drake	   - EC-driven system wakeups
27867feda8e9SDaniel Drake	   - Power button
27877bc74b3dSDaniel Drake	   - Ebook switch
27882cf2baeaSDaniel Drake	   - Lid switch
2789e1040ac6SDaniel Drake	   - AC adapter status updates
2790e1040ac6SDaniel Drake	   - Battery status updates
27917feda8e9SDaniel Drake
2792a0f30f59SDaniel Drakeconfig OLPC_XO15_SCI
2793a0f30f59SDaniel Drake	bool "OLPC XO-1.5 SCI extras"
2794d8d01a63SDaniel Drake	depends on OLPC && ACPI
2795d8d01a63SDaniel Drake	select POWER_SUPPLY
2796a0f30f59SDaniel Drake	---help---
2797a0f30f59SDaniel Drake	  Add support for SCI-based features of the OLPC XO-1.5 laptop:
2798a0f30f59SDaniel Drake	   - EC-driven system wakeups
2799a0f30f59SDaniel Drake	   - AC adapter status updates
2800a0f30f59SDaniel Drake	   - Battery status updates
2801e279b6c1SSam Ravnborg
2802d4f3e350SEd Wildgooseconfig ALIX
2803d4f3e350SEd Wildgoose	bool "PCEngines ALIX System Support (LED setup)"
2804d4f3e350SEd Wildgoose	select GPIOLIB
2805d4f3e350SEd Wildgoose	---help---
2806d4f3e350SEd Wildgoose	  This option enables system support for the PCEngines ALIX.
2807d4f3e350SEd Wildgoose	  At present this just sets up LEDs for GPIO control on
2808d4f3e350SEd Wildgoose	  ALIX2/3/6 boards.  However, other system specific setup should
2809d4f3e350SEd Wildgoose	  get added here.
2810d4f3e350SEd Wildgoose
2811d4f3e350SEd Wildgoose	  Note: You must still enable the drivers for GPIO and LED support
2812d4f3e350SEd Wildgoose	  (GPIO_CS5535 & LEDS_GPIO) to actually use the LEDs
2813d4f3e350SEd Wildgoose
2814d4f3e350SEd Wildgoose	  Note: You have to set alix.force=1 for boards with Award BIOS.
2815d4f3e350SEd Wildgoose
2816da4e3302SPhilip Prindevilleconfig NET5501
2817da4e3302SPhilip Prindeville	bool "Soekris Engineering net5501 System Support (LEDS, GPIO, etc)"
2818da4e3302SPhilip Prindeville	select GPIOLIB
2819da4e3302SPhilip Prindeville	---help---
2820da4e3302SPhilip Prindeville	  This option enables system support for the Soekris Engineering net5501.
2821da4e3302SPhilip Prindeville
28223197059aSPhilip A. Prindevilleconfig GEOS
28233197059aSPhilip A. Prindeville	bool "Traverse Technologies GEOS System Support (LEDS, GPIO, etc)"
28243197059aSPhilip A. Prindeville	select GPIOLIB
28253197059aSPhilip A. Prindeville	depends on DMI
28263197059aSPhilip A. Prindeville	---help---
28273197059aSPhilip A. Prindeville	  This option enables system support for the Traverse Technologies GEOS.
28283197059aSPhilip A. Prindeville
28297d029125SVivien Didelotconfig TS5500
28307d029125SVivien Didelot	bool "Technologic Systems TS-5500 platform support"
28317d029125SVivien Didelot	depends on MELAN
28327d029125SVivien Didelot	select CHECK_SIGNATURE
28337d029125SVivien Didelot	select NEW_LEDS
28347d029125SVivien Didelot	select LEDS_CLASS
28357d029125SVivien Didelot	---help---
28367d029125SVivien Didelot	  This option enables system support for the Technologic Systems TS-5500.
28377d029125SVivien Didelot
2838e279b6c1SSam Ravnborgendif # X86_32
2839e279b6c1SSam Ravnborg
284023ac4ae8SAndreas Herrmannconfig AMD_NB
2841e279b6c1SSam Ravnborg	def_bool y
28420e152cd7SBorislav Petkov	depends on CPU_SUP_AMD && PCI
2843e279b6c1SSam Ravnborg
2844e3263ab3SDavid Herrmannconfig X86_SYSFB
2845e3263ab3SDavid Herrmann	bool "Mark VGA/VBE/EFI FB as generic system framebuffer"
2846e3263ab3SDavid Herrmann	help
2847e3263ab3SDavid Herrmann	  Firmwares often provide initial graphics framebuffers so the BIOS,
2848e3263ab3SDavid Herrmann	  bootloader or kernel can show basic video-output during boot for
2849e3263ab3SDavid Herrmann	  user-guidance and debugging. Historically, x86 used the VESA BIOS
2850e3263ab3SDavid Herrmann	  Extensions and EFI-framebuffers for this, which are mostly limited
2851e3263ab3SDavid Herrmann	  to x86.
2852e3263ab3SDavid Herrmann	  This option, if enabled, marks VGA/VBE/EFI framebuffers as generic
2853e3263ab3SDavid Herrmann	  framebuffers so the new generic system-framebuffer drivers can be
2854e3263ab3SDavid Herrmann	  used on x86. If the framebuffer is not compatible with the generic
2855e3a5dc08SNikolas Nyby	  modes, it is advertised as fallback platform framebuffer so legacy
2856e3263ab3SDavid Herrmann	  drivers like efifb, vesafb and uvesafb can pick it up.
2857e3263ab3SDavid Herrmann	  If this option is not selected, all system framebuffers are always
2858e3263ab3SDavid Herrmann	  marked as fallback platform framebuffers as usual.
2859e3263ab3SDavid Herrmann
2860e3263ab3SDavid Herrmann	  Note: Legacy fbdev drivers, including vesafb, efifb, uvesafb, will
2861e3263ab3SDavid Herrmann	  not be able to pick up generic system framebuffers if this option
2862e3263ab3SDavid Herrmann	  is selected. You are highly encouraged to enable simplefb as
2863e3263ab3SDavid Herrmann	  replacement if you select this option. simplefb can correctly deal
2864e3263ab3SDavid Herrmann	  with generic system framebuffers. But you should still keep vesafb
2865e3263ab3SDavid Herrmann	  and others enabled as fallback if a system framebuffer is
2866e3263ab3SDavid Herrmann	  incompatible with simplefb.
2867e3263ab3SDavid Herrmann
2868e3263ab3SDavid Herrmann	  If unsure, say Y.
2869e3263ab3SDavid Herrmann
2870e279b6c1SSam Ravnborgendmenu
2871e279b6c1SSam Ravnborg
2872e279b6c1SSam Ravnborg
28731572497cSChristoph Hellwigmenu "Binary Emulations"
2874e279b6c1SSam Ravnborg
2875e279b6c1SSam Ravnborgconfig IA32_EMULATION
2876e279b6c1SSam Ravnborg	bool "IA32 Emulation"
2877e279b6c1SSam Ravnborg	depends on X86_64
287839f88911SIngo Molnar	select ARCH_WANT_OLD_COMPAT_IPC
2879d1603990SRandy Dunlap	select BINFMT_ELF
2880a97f52e6SRoland McGrath	select COMPAT_BINFMT_ELF
288139f88911SIngo Molnar	select COMPAT_OLD_SIGACTION
28828f9ca475SIngo Molnar	---help---
28835fd92e65SH. J. Lu	  Include code to run legacy 32-bit programs under a
28845fd92e65SH. J. Lu	  64-bit kernel. You should likely turn this on, unless you're
28855fd92e65SH. J. Lu	  100% sure that you don't have any 32-bit programs left.
2886e279b6c1SSam Ravnborg
2887e279b6c1SSam Ravnborgconfig IA32_AOUT
2888e279b6c1SSam Ravnborg	tristate "IA32 a.out support"
28896b213e1bSDavid Woodhouse	depends on IA32_EMULATION
2890eac61655SBorislav Petkov	depends on BROKEN
28918f9ca475SIngo Molnar	---help---
2892e279b6c1SSam Ravnborg	  Support old a.out binaries in the 32bit emulation.
2893e279b6c1SSam Ravnborg
28940bf62763SH. Peter Anvinconfig X86_X32
28956ea30386SKees Cook	bool "x32 ABI for 64-bit mode"
28969b54050bSBrian Gerst	depends on X86_64
28975fd92e65SH. J. Lu	---help---
28985fd92e65SH. J. Lu	  Include code to run binaries for the x32 native 32-bit ABI
28995fd92e65SH. J. Lu	  for 64-bit processors.  An x32 process gets access to the
29005fd92e65SH. J. Lu	  full 64-bit register file and wide data path while leaving
29015fd92e65SH. J. Lu	  pointers at 32 bits for smaller memory footprint.
29025fd92e65SH. J. Lu
29035fd92e65SH. J. Lu	  You will need a recent binutils (2.22 or later) with
29045fd92e65SH. J. Lu	  elf32_x86_64 support enabled to compile a kernel with this
29055fd92e65SH. J. Lu	  option set.
29065fd92e65SH. J. Lu
2907953fee1dSIngo Molnarconfig COMPAT_32
2908953fee1dSIngo Molnar	def_bool y
2909953fee1dSIngo Molnar	depends on IA32_EMULATION || X86_32
2910953fee1dSIngo Molnar	select HAVE_UID16
2911953fee1dSIngo Molnar	select OLD_SIGSUSPEND3
2912953fee1dSIngo Molnar
2913e279b6c1SSam Ravnborgconfig COMPAT
29143c2362e6SHarvey Harrison	def_bool y
29150bf62763SH. Peter Anvin	depends on IA32_EMULATION || X86_X32
2916e279b6c1SSam Ravnborg
29173120e25eSJan Beulichif COMPAT
2918e279b6c1SSam Ravnborgconfig COMPAT_FOR_U64_ALIGNMENT
29193120e25eSJan Beulich	def_bool y
2920e279b6c1SSam Ravnborg
2921e279b6c1SSam Ravnborgconfig SYSVIPC_COMPAT
29223c2362e6SHarvey Harrison	def_bool y
29233120e25eSJan Beulich	depends on SYSVIPC
29243120e25eSJan Beulichendif
2925ee009e4aSDavid Howells
2926e279b6c1SSam Ravnborgendmenu
2927e279b6c1SSam Ravnborg
2928e279b6c1SSam Ravnborg
2929e5beae16SKeith Packardconfig HAVE_ATOMIC_IOMAP
2930e5beae16SKeith Packard	def_bool y
2931e5beae16SKeith Packard	depends on X86_32
2932e5beae16SKeith Packard
2933e279b6c1SSam Ravnborgsource "drivers/firmware/Kconfig"
2934e279b6c1SSam Ravnborg
2935edf88417SAvi Kivitysource "arch/x86/kvm/Kconfig"
29365e8ebd84SJason A. Donenfeld
29375e8ebd84SJason A. Donenfeldsource "arch/x86/Kconfig.assembler"
2938