xref: /linux/arch/x86/Kconfig (revision ec6347bb43395cb92126788a1a5b25302543f815)
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"
6a7f7f624SMasahiro Yamada	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
62399145f9SAnshuman Khandual	select ARCH_HAS_DEBUG_VM_PGTABLE	if !X86_PAE
6321266be9SDan Williams	select ARCH_HAS_DEVMEM_IS_ALLOWED
64b1a57bbfSDouglas Anderson	select ARCH_HAS_EARLY_DEBUG		if KGDB
656471b825SIngo Molnar	select ARCH_HAS_ELF_RANDOMIZE
6672d93104SLinus Torvalds	select ARCH_HAS_FAST_MULTIPLIER
67316d097cSDave Hansen	select ARCH_HAS_FILTER_PGPROT
686974f0c4SDaniel Micay	select ARCH_HAS_FORTIFY_SOURCE
69957e3facSRiku Voipio	select ARCH_HAS_GCOV_PROFILE_ALL
700f1441b4SPeter Zijlstra	select ARCH_HAS_KCOV			if X86_64 && STACK_VALIDATION
710c9c1d56SThiago Jung Bauermann	select ARCH_HAS_MEM_ENCRYPT
7210bcc80eSMathieu Desnoyers	select ARCH_HAS_MEMBARRIER_SYNC_CORE
730ebeea8cSDaniel Borkmann	select ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE
74c763ea26SIngo Molnar	select ARCH_HAS_PMEM_API		if X86_64
7517596731SRobin Murphy	select ARCH_HAS_PTE_DEVMAP		if X86_64
763010a5eaSLaurent Dufour	select ARCH_HAS_PTE_SPECIAL
770aed55afSDan Williams	select ARCH_HAS_UACCESS_FLUSHCACHE	if X86_64
78*ec6347bbSDan Williams	select ARCH_HAS_COPY_MC			if X86_64
79d2852a22SDaniel Borkmann	select ARCH_HAS_SET_MEMORY
80d253ca0cSRick Edgecombe	select ARCH_HAS_SET_DIRECT_MAP
81ad21fc4fSLaura Abbott	select ARCH_HAS_STRICT_KERNEL_RWX
82ad21fc4fSLaura Abbott	select ARCH_HAS_STRICT_MODULE_RWX
83ac1ab12aSMathieu Desnoyers	select ARCH_HAS_SYNC_CORE_BEFORE_USERMODE
8425c619e5SBrian Gerst	select ARCH_HAS_SYSCALL_WRAPPER
85c6d30853SAndrey Ryabinin	select ARCH_HAS_UBSAN_SANITIZE_ALL
867e01ccb4SZong Li	select ARCH_HAS_DEBUG_WX
876471b825SIngo Molnar	select ARCH_HAVE_NMI_SAFE_CMPXCHG
886471b825SIngo Molnar	select ARCH_MIGHT_HAVE_ACPI_PDC		if ACPI
8977fbbc81SMark Salter	select ARCH_MIGHT_HAVE_PC_PARPORT
905e2c18c0SMark Salter	select ARCH_MIGHT_HAVE_PC_SERIO
913599fe12SThomas Gleixner	select ARCH_STACKWALK
922c870e61SArnd Bergmann	select ARCH_SUPPORTS_ACPI
936471b825SIngo Molnar	select ARCH_SUPPORTS_ATOMIC_RMW
946471b825SIngo Molnar	select ARCH_SUPPORTS_NUMA_BALANCING	if X86_64
956471b825SIngo Molnar	select ARCH_USE_BUILTIN_BSWAP
966471b825SIngo Molnar	select ARCH_USE_QUEUED_RWLOCKS
976471b825SIngo Molnar	select ARCH_USE_QUEUED_SPINLOCKS
982ce0d7f9SMark Brown	select ARCH_USE_SYM_ANNOTATIONS
99ce4a4e56SAndy Lutomirski	select ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH
10081c22041SDaniel Borkmann	select ARCH_WANT_DEFAULT_BPF_JIT	if X86_64
101c763ea26SIngo Molnar	select ARCH_WANTS_DYNAMIC_TASK_STRUCT
1023876d4a3SAlexandre Ghiti	select ARCH_WANT_HUGE_PMD_SHARE
10338d8b4e6SHuang Ying	select ARCH_WANTS_THP_SWAP		if X86_64
10410916706SShile Zhang	select BUILDTIME_TABLE_SORT
1056471b825SIngo Molnar	select CLKEVT_I8253
1066471b825SIngo Molnar	select CLOCKSOURCE_VALIDATE_LAST_CYCLE
1076471b825SIngo Molnar	select CLOCKSOURCE_WATCHDOG
1086471b825SIngo Molnar	select DCACHE_WORD_ACCESS
10945471cd9SLinus Torvalds	select EDAC_ATOMIC_SCRUB
11045471cd9SLinus Torvalds	select EDAC_SUPPORT
1116471b825SIngo Molnar	select GENERIC_CLOCKEVENTS
1126471b825SIngo Molnar	select GENERIC_CLOCKEVENTS_BROADCAST	if X86_64 || (X86_32 && X86_LOCAL_APIC)
1136471b825SIngo Molnar	select GENERIC_CLOCKEVENTS_MIN_ADJUST
1146471b825SIngo Molnar	select GENERIC_CMOS_UPDATE
1156471b825SIngo Molnar	select GENERIC_CPU_AUTOPROBE
11661dc0f55SThomas Gleixner	select GENERIC_CPU_VULNERABILITIES
1176471b825SIngo Molnar	select GENERIC_EARLY_IOREMAP
11827d6b4d1SThomas Gleixner	select GENERIC_ENTRY
1196471b825SIngo Molnar	select GENERIC_FIND_FIRST_BIT
1206471b825SIngo Molnar	select GENERIC_IOMAP
121c7d6c9ddSThomas Gleixner	select GENERIC_IRQ_EFFECTIVE_AFF_MASK	if SMP
1220fa115daSThomas Gleixner	select GENERIC_IRQ_MATRIX_ALLOCATOR	if X86_LOCAL_APIC
123ad7a929fSThomas Gleixner	select GENERIC_IRQ_MIGRATION		if SMP
1246471b825SIngo Molnar	select GENERIC_IRQ_PROBE
125c201c917SThomas Gleixner	select GENERIC_IRQ_RESERVATION_MODE
1266471b825SIngo Molnar	select GENERIC_IRQ_SHOW
1276471b825SIngo Molnar	select GENERIC_PENDING_IRQ		if SMP
1282ae27137SSteven Price	select GENERIC_PTDUMP
1296471b825SIngo Molnar	select GENERIC_SMP_IDLE_THREAD
1306471b825SIngo Molnar	select GENERIC_STRNCPY_FROM_USER
1316471b825SIngo Molnar	select GENERIC_STRNLEN_USER
1326471b825SIngo Molnar	select GENERIC_TIME_VSYSCALL
1337ac87074SVincenzo Frascino	select GENERIC_GETTIMEOFDAY
134550a77a7SDmitry Safonov	select GENERIC_VDSO_TIME_NS
13539656e83SChristoph Hellwig	select GUP_GET_PTE_LOW_HIGH		if X86_PAE
13617e5888eSHans de Goede	select HARDIRQS_SW_RESEND
1377edaeb68SThomas Gleixner	select HARDLOCKUP_CHECK_TIMESTAMP	if X86_64
1386471b825SIngo Molnar	select HAVE_ACPI_APEI			if ACPI
1396471b825SIngo Molnar	select HAVE_ACPI_APEI_NMI		if ACPI
1406471b825SIngo Molnar	select HAVE_ALIGNED_STRUCT_PAGE		if SLUB
1416471b825SIngo Molnar	select HAVE_ARCH_AUDITSYSCALL
1426471b825SIngo Molnar	select HAVE_ARCH_HUGE_VMAP		if X86_64 || X86_PAE
1436471b825SIngo Molnar	select HAVE_ARCH_JUMP_LABEL
144b34006c4SArd Biesheuvel	select HAVE_ARCH_JUMP_LABEL_RELATIVE
145d17a1d97SAndrey Ryabinin	select HAVE_ARCH_KASAN			if X86_64
1460609ae01SDaniel Axtens	select HAVE_ARCH_KASAN_VMALLOC		if X86_64
1476471b825SIngo Molnar	select HAVE_ARCH_KGDB
1489e08f57dSDaniel Cashman	select HAVE_ARCH_MMAP_RND_BITS		if MMU
1499e08f57dSDaniel Cashman	select HAVE_ARCH_MMAP_RND_COMPAT_BITS	if MMU && COMPAT
1501b028f78SDmitry Safonov	select HAVE_ARCH_COMPAT_MMAP_BASES	if MMU && COMPAT
151271ca788SArd Biesheuvel	select HAVE_ARCH_PREL32_RELOCATIONS
1526471b825SIngo Molnar	select HAVE_ARCH_SECCOMP_FILTER
153f7d83c1cSKees Cook	select HAVE_ARCH_THREAD_STRUCT_WHITELIST
154afaef01cSAlexander Popov	select HAVE_ARCH_STACKLEAK
1556471b825SIngo Molnar	select HAVE_ARCH_TRACEHOOK
1566471b825SIngo Molnar	select HAVE_ARCH_TRANSPARENT_HUGEPAGE
157a00cc7d9SMatthew Wilcox	select HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD if X86_64
158b64d8d1eSPeter Xu	select HAVE_ARCH_USERFAULTFD_WP         if X86_64 && USERFAULTFD
159e37e43a4SAndy Lutomirski	select HAVE_ARCH_VMAP_STACK		if X86_64
160c763ea26SIngo Molnar	select HAVE_ARCH_WITHIN_STACK_FRAMES
1612ff2b7ecSMasahiro Yamada	select HAVE_ASM_MODVERSIONS
1626471b825SIngo Molnar	select HAVE_CMPXCHG_DOUBLE
1636471b825SIngo Molnar	select HAVE_CMPXCHG_LOCAL
1646471b825SIngo Molnar	select HAVE_CONTEXT_TRACKING		if X86_64
1656471b825SIngo Molnar	select HAVE_C_RECORDMCOUNT
1666471b825SIngo Molnar	select HAVE_DEBUG_KMEMLEAK
1679c5a3621SAkinobu Mita	select HAVE_DMA_CONTIGUOUS
168677aa9f7SSteven Rostedt	select HAVE_DYNAMIC_FTRACE
16906aeaaeaSMasami Hiramatsu	select HAVE_DYNAMIC_FTRACE_WITH_REGS
170562955feSSteven Rostedt (VMware)	select HAVE_DYNAMIC_FTRACE_WITH_DIRECT_CALLS
17103f5781bSWang YanQing	select HAVE_EBPF_JIT
17258340a07SJohannes Berg	select HAVE_EFFICIENT_UNALIGNED_ACCESS
1736630a8e5SChristoph Hellwig	select HAVE_EISA
1745f56a5dfSJiri Slaby	select HAVE_EXIT_THREAD
17567a929e0SChristoph Hellwig	select HAVE_FAST_GUP
176644e0e8dSSteven Rostedt (VMware)	select HAVE_FENTRY			if X86_64 || DYNAMIC_FTRACE
1776471b825SIngo Molnar	select HAVE_FTRACE_MCOUNT_RECORD
1786471b825SIngo Molnar	select HAVE_FUNCTION_GRAPH_TRACER
1796471b825SIngo Molnar	select HAVE_FUNCTION_TRACER
1806b90bd4bSEmese Revfy	select HAVE_GCC_PLUGINS
1810067f129SK.Prasad	select HAVE_HW_BREAKPOINT
1826471b825SIngo Molnar	select HAVE_IDE
1836471b825SIngo Molnar	select HAVE_IOREMAP_PROT
1846471b825SIngo Molnar	select HAVE_IRQ_TIME_ACCOUNTING
1856471b825SIngo Molnar	select HAVE_KERNEL_BZIP2
1866471b825SIngo Molnar	select HAVE_KERNEL_GZIP
1876471b825SIngo Molnar	select HAVE_KERNEL_LZ4
1886471b825SIngo Molnar	select HAVE_KERNEL_LZMA
1896471b825SIngo Molnar	select HAVE_KERNEL_LZO
1906471b825SIngo Molnar	select HAVE_KERNEL_XZ
191fb46d057SNick Terrell	select HAVE_KERNEL_ZSTD
1926471b825SIngo Molnar	select HAVE_KPROBES
1936471b825SIngo Molnar	select HAVE_KPROBES_ON_FTRACE
194540adea3SMasami Hiramatsu	select HAVE_FUNCTION_ERROR_INJECTION
1956471b825SIngo Molnar	select HAVE_KRETPROBES
1966471b825SIngo Molnar	select HAVE_KVM
1976471b825SIngo Molnar	select HAVE_LIVEPATCH			if X86_64
1980102752eSFrederic Weisbecker	select HAVE_MIXED_BREAKPOINTS_REGS
199ee9f8fceSJosh Poimboeuf	select HAVE_MOD_ARCH_SPECIFIC
2009f132f7eSJoel Fernandes (Google)	select HAVE_MOVE_PMD
20142a0bb3fSPetr Mladek	select HAVE_NMI
2026471b825SIngo Molnar	select HAVE_OPROFILE
2036471b825SIngo Molnar	select HAVE_OPTPROBES
2046471b825SIngo Molnar	select HAVE_PCSPKR_PLATFORM
2056471b825SIngo Molnar	select HAVE_PERF_EVENTS
206c01d4323SFrederic Weisbecker	select HAVE_PERF_EVENTS_NMI
20792e5aae4SNicholas Piggin	select HAVE_HARDLOCKUP_DETECTOR_PERF	if PERF_EVENTS && HAVE_PERF_EVENTS_NMI
208eb01d42aSChristoph Hellwig	select HAVE_PCI
209c5e63197SJiri Olsa	select HAVE_PERF_REGS
210c5ebcedbSJiri Olsa	select HAVE_PERF_USER_STACK_DUMP
211ff2e6d72SPeter Zijlstra	select MMU_GATHER_RCU_TABLE_FREE		if PARAVIRT
21200998085SThomas Gleixner	select HAVE_POSIX_CPU_TIMERS_TASK_WORK
2136471b825SIngo Molnar	select HAVE_REGS_AND_STACK_ACCESS_API
2146415b38bSJiri Slaby	select HAVE_RELIABLE_STACKTRACE		if X86_64 && (UNWINDER_FRAME_POINTER || UNWINDER_ORC) && STACK_VALIDATION
2153c88ee19SMasami Hiramatsu	select HAVE_FUNCTION_ARG_ACCESS_API
216d148eac0SMasahiro Yamada	select HAVE_STACKPROTECTOR		if CC_HAS_SANE_STACKPROTECTOR
217c763ea26SIngo Molnar	select HAVE_STACK_VALIDATION		if X86_64
218d6761b8fSMathieu Desnoyers	select HAVE_RSEQ
2196471b825SIngo Molnar	select HAVE_SYSCALL_TRACEPOINTS
2206471b825SIngo Molnar	select HAVE_UNSTABLE_SCHED_CLOCK
2217c68af6eSAvi Kivity	select HAVE_USER_RETURN_NOTIFIER
2227ac87074SVincenzo Frascino	select HAVE_GENERIC_VDSO
22305736e4aSThomas Gleixner	select HOTPLUG_SMT			if SMP
224c0185808SThomas Gleixner	select IRQ_FORCED_THREADING
22586596f0aSChristoph Hellwig	select NEED_SG_DMA_LENGTH
2262eac9c2dSChristoph Hellwig	select PCI_DOMAINS			if PCI
227625210cfSSinan Kaya	select PCI_LOCKLESS_CONFIG		if PCI
2286471b825SIngo Molnar	select PERF_EVENTS
2293195ef59SPrarit Bhargava	select RTC_LIB
230d6faca40SArnd Bergmann	select RTC_MC146818_LIB
2316471b825SIngo Molnar	select SPARSE_IRQ
23283fe27eaSPranith Kumar	select SRCU
2336471b825SIngo Molnar	select SYSCTL_EXCEPTION_TRACE
23415f4eae7SAndy Lutomirski	select THREAD_INFO_IN_TASK
2356471b825SIngo Molnar	select USER_STACKTRACE_SUPPORT
2366471b825SIngo Molnar	select VIRT_TO_BUS
2373b02a051SIngo Molnar	select HAVE_ARCH_KCSAN			if X86_64
2386471b825SIngo Molnar	select X86_FEATURE_NAMES		if PROC_FS
2390c608dadSAubrey Li	select PROC_PID_ARCH_STATUS		if PROC_FS
2409e2b4be3SNayna Jain	imply IMA_SECURE_AND_OR_TRUSTED_BOOT    if EFI
2417d8330a5SBalbir Singh
242ba7e4d13SIngo Molnarconfig INSTRUCTION_DECODER
2433120e25eSJan Beulich	def_bool y
2443120e25eSJan Beulich	depends on KPROBES || PERF_EVENTS || UPROBES
245ba7e4d13SIngo Molnar
24651b26adaSLinus Torvaldsconfig OUTPUT_FORMAT
24751b26adaSLinus Torvalds	string
24851b26adaSLinus Torvalds	default "elf32-i386" if X86_32
24951b26adaSLinus Torvalds	default "elf64-x86-64" if X86_64
25051b26adaSLinus Torvalds
2518d5fffb9SSam Ravnborgconfig LOCKDEP_SUPPORT
2523c2362e6SHarvey Harrison	def_bool y
2538d5fffb9SSam Ravnborg
2548d5fffb9SSam Ravnborgconfig STACKTRACE_SUPPORT
2553c2362e6SHarvey Harrison	def_bool y
2568d5fffb9SSam Ravnborg
2578d5fffb9SSam Ravnborgconfig MMU
2583c2362e6SHarvey Harrison	def_bool y
2598d5fffb9SSam Ravnborg
2609e08f57dSDaniel Cashmanconfig ARCH_MMAP_RND_BITS_MIN
2619e08f57dSDaniel Cashman	default 28 if 64BIT
2629e08f57dSDaniel Cashman	default 8
2639e08f57dSDaniel Cashman
2649e08f57dSDaniel Cashmanconfig ARCH_MMAP_RND_BITS_MAX
2659e08f57dSDaniel Cashman	default 32 if 64BIT
2669e08f57dSDaniel Cashman	default 16
2679e08f57dSDaniel Cashman
2689e08f57dSDaniel Cashmanconfig ARCH_MMAP_RND_COMPAT_BITS_MIN
2699e08f57dSDaniel Cashman	default 8
2709e08f57dSDaniel Cashman
2719e08f57dSDaniel Cashmanconfig ARCH_MMAP_RND_COMPAT_BITS_MAX
2729e08f57dSDaniel Cashman	default 16
2739e08f57dSDaniel Cashman
2748d5fffb9SSam Ravnborgconfig SBUS
2758d5fffb9SSam Ravnborg	bool
2768d5fffb9SSam Ravnborg
2778d5fffb9SSam Ravnborgconfig GENERIC_ISA_DMA
2783120e25eSJan Beulich	def_bool y
2793120e25eSJan Beulich	depends on ISA_DMA_API
2808d5fffb9SSam Ravnborg
2818d5fffb9SSam Ravnborgconfig GENERIC_BUG
2823c2362e6SHarvey Harrison	def_bool y
2838d5fffb9SSam Ravnborg	depends on BUG
284b93a531eSJan Beulich	select GENERIC_BUG_RELATIVE_POINTERS if X86_64
285b93a531eSJan Beulich
286b93a531eSJan Beulichconfig GENERIC_BUG_RELATIVE_POINTERS
287b93a531eSJan Beulich	bool
2888d5fffb9SSam Ravnborg
2898d5fffb9SSam Ravnborgconfig ARCH_MAY_HAVE_PC_FDC
2903120e25eSJan Beulich	def_bool y
2913120e25eSJan Beulich	depends on ISA_DMA_API
2928d5fffb9SSam Ravnborg
2931032c0baSSam Ravnborgconfig GENERIC_CALIBRATE_DELAY
2941032c0baSSam Ravnborg	def_bool y
2951032c0baSSam Ravnborg
2969a0b8415Svenkatesh.pallipadi@intel.comconfig ARCH_HAS_CPU_RELAX
2979a0b8415Svenkatesh.pallipadi@intel.com	def_bool y
2988d5fffb9SSam Ravnborg
2991b27d05bSPekka Enbergconfig ARCH_HAS_CACHE_LINE_SIZE
3001b27d05bSPekka Enberg	def_bool y
3011b27d05bSPekka Enberg
302316d097cSDave Hansenconfig ARCH_HAS_FILTER_PGPROT
303316d097cSDave Hansen	def_bool y
304316d097cSDave Hansen
305dd5af90aSMike Travisconfig HAVE_SETUP_PER_CPU_AREA
30689c9c4c5SBrian Gerst	def_bool y
307b32ef636Stravis@sgi.com
30808fc4580STejun Heoconfig NEED_PER_CPU_EMBED_FIRST_CHUNK
30908fc4580STejun Heo	def_bool y
31008fc4580STejun Heo
31108fc4580STejun Heoconfig NEED_PER_CPU_PAGE_FIRST_CHUNK
31211124411STejun Heo	def_bool y
31311124411STejun Heo
314801e4062SJohannes Bergconfig ARCH_HIBERNATION_POSSIBLE
315801e4062SJohannes Berg	def_bool y
316801e4062SJohannes Berg
317f4cb5700SJohannes Bergconfig ARCH_SUSPEND_POSSIBLE
318f4cb5700SJohannes Berg	def_bool y
319f4cb5700SJohannes Berg
32053313b2cSSteve Capperconfig ARCH_WANT_GENERAL_HUGETLB
32153313b2cSSteve Capper	def_bool y
32253313b2cSSteve Capper
3238d5fffb9SSam Ravnborgconfig ZONE_DMA32
324e0fd24a3SJan Beulich	def_bool y if X86_64
3258d5fffb9SSam Ravnborg
3268d5fffb9SSam Ravnborgconfig AUDIT_ARCH
327e0fd24a3SJan Beulich	def_bool y if X86_64
3288d5fffb9SSam Ravnborg
3296a11f75bSAkinobu Mitaconfig ARCH_SUPPORTS_DEBUG_PAGEALLOC
3306a11f75bSAkinobu Mita	def_bool y
3316a11f75bSAkinobu Mita
332d6f2d75aSAndrey Ryabininconfig KASAN_SHADOW_OFFSET
333d6f2d75aSAndrey Ryabinin	hex
334d6f2d75aSAndrey Ryabinin	depends on KASAN
335d6f2d75aSAndrey Ryabinin	default 0xdffffc0000000000
336d6f2d75aSAndrey Ryabinin
33769575d38SShane Wangconfig HAVE_INTEL_TXT
33869575d38SShane Wang	def_bool y
3396ea30386SKees Cook	depends on INTEL_IOMMU && ACPI
34069575d38SShane Wang
3416b0c3d44SSam Ravnborgconfig X86_32_SMP
3426b0c3d44SSam Ravnborg	def_bool y
3436b0c3d44SSam Ravnborg	depends on X86_32 && SMP
3446b0c3d44SSam Ravnborg
3456b0c3d44SSam Ravnborgconfig X86_64_SMP
3466b0c3d44SSam Ravnborg	def_bool y
3476b0c3d44SSam Ravnborg	depends on X86_64 && SMP
3486b0c3d44SSam Ravnborg
349ccbeed3aSTejun Heoconfig X86_32_LAZY_GS
350ccbeed3aSTejun Heo	def_bool y
3518458f8c2SMasahiro Yamada	depends on X86_32 && !STACKPROTECTOR
352ccbeed3aSTejun Heo
3532b144498SSrikar Dronamrajuconfig ARCH_SUPPORTS_UPROBES
3542b144498SSrikar Dronamraju	def_bool y
3552b144498SSrikar Dronamraju
356d20642f0SRob Herringconfig FIX_EARLYCON_MEM
357d20642f0SRob Herring	def_bool y
358d20642f0SRob Herring
35994d49eb3SKirill A. Shutemovconfig DYNAMIC_PHYSICAL_MASK
36094d49eb3SKirill A. Shutemov	bool
36194d49eb3SKirill A. Shutemov
36298233368SKirill A. Shutemovconfig PGTABLE_LEVELS
36398233368SKirill A. Shutemov	int
36477ef56e4SKirill A. Shutemov	default 5 if X86_5LEVEL
36598233368SKirill A. Shutemov	default 4 if X86_64
36698233368SKirill A. Shutemov	default 3 if X86_PAE
36798233368SKirill A. Shutemov	default 2
36898233368SKirill A. Shutemov
3692a61f474SMasahiro Yamadaconfig CC_HAS_SANE_STACKPROTECTOR
3702a61f474SMasahiro Yamada	bool
3712a61f474SMasahiro Yamada	default $(success,$(srctree)/scripts/gcc-x86_64-has-stack-protector.sh $(CC)) if 64BIT
3722a61f474SMasahiro Yamada	default $(success,$(srctree)/scripts/gcc-x86_32-has-stack-protector.sh $(CC))
3732a61f474SMasahiro Yamada	help
3742a61f474SMasahiro Yamada	   We have to make sure stack protector is unconditionally disabled if
3752a61f474SMasahiro Yamada	   the compiler produces broken code.
3762a61f474SMasahiro Yamada
377506f1d07SSam Ravnborgmenu "Processor type and features"
378506f1d07SSam Ravnborg
3795ee71535SRandy Dunlapconfig ZONE_DMA
3805ee71535SRandy Dunlap	bool "DMA memory allocation support" if EXPERT
3815ee71535SRandy Dunlap	default y
3825ee71535SRandy Dunlap	help
3835ee71535SRandy Dunlap	  DMA memory allocation support allows devices with less than 32-bit
3845ee71535SRandy Dunlap	  addressing to allocate within the first 16MB of address space.
3855ee71535SRandy Dunlap	  Disable if no such devices will be used.
3865ee71535SRandy Dunlap
3875ee71535SRandy Dunlap	  If unsure, say Y.
3885ee71535SRandy Dunlap
389506f1d07SSam Ravnborgconfig SMP
390506f1d07SSam Ravnborg	bool "Symmetric multi-processing support"
391a7f7f624SMasahiro Yamada	help
392506f1d07SSam Ravnborg	  This enables support for systems with more than one CPU. If you have
3934a474157SRobert Graffham	  a system with only one CPU, say N. If you have a system with more
3944a474157SRobert Graffham	  than one CPU, say Y.
395506f1d07SSam Ravnborg
3964a474157SRobert Graffham	  If you say N here, the kernel will run on uni- and multiprocessor
397506f1d07SSam Ravnborg	  machines, but will use only one CPU of a multiprocessor machine. If
398506f1d07SSam Ravnborg	  you say Y here, the kernel will run on many, but not all,
3994a474157SRobert Graffham	  uniprocessor machines. On a uniprocessor machine, the kernel
400506f1d07SSam Ravnborg	  will run faster if you say N here.
401506f1d07SSam Ravnborg
402506f1d07SSam Ravnborg	  Note that if you say Y here and choose architecture "586" or
403506f1d07SSam Ravnborg	  "Pentium" under "Processor family", the kernel will not work on 486
404506f1d07SSam Ravnborg	  architectures. Similarly, multiprocessor kernels for the "PPro"
405506f1d07SSam Ravnborg	  architecture may not work on all Pentium based boards.
406506f1d07SSam Ravnborg
407506f1d07SSam Ravnborg	  People using multiprocessor machines who say Y here should also say
408506f1d07SSam Ravnborg	  Y to "Enhanced Real Time Clock Support", below. The "Advanced Power
409506f1d07SSam Ravnborg	  Management" code will be disabled if you say Y here.
410506f1d07SSam Ravnborg
411cb1aaebeSMauro Carvalho Chehab	  See also <file:Documentation/x86/i386/IO-APIC.rst>,
4124f4cfa6cSMauro Carvalho Chehab	  <file:Documentation/admin-guide/lockup-watchdogs.rst> and the SMP-HOWTO available at
413506f1d07SSam Ravnborg	  <http://www.tldp.org/docs.html#howto>.
414506f1d07SSam Ravnborg
415506f1d07SSam Ravnborg	  If you don't know what to do here, say N.
416506f1d07SSam Ravnborg
4179def39beSJosh Triplettconfig X86_FEATURE_NAMES
4189def39beSJosh Triplett	bool "Processor feature human-readable names" if EMBEDDED
4199def39beSJosh Triplett	default y
420a7f7f624SMasahiro Yamada	help
4219def39beSJosh Triplett	  This option compiles in a table of x86 feature bits and corresponding
4229def39beSJosh Triplett	  names.  This is required to support /proc/cpuinfo and a few kernel
4239def39beSJosh Triplett	  messages.  You can disable this to save space, at the expense of
4249def39beSJosh Triplett	  making those few kernel messages show numeric feature bits instead.
4259def39beSJosh Triplett
4269def39beSJosh Triplett	  If in doubt, say Y.
4279def39beSJosh Triplett
42806cd9a7dSYinghai Luconfig X86_X2APIC
42906cd9a7dSYinghai Lu	bool "Support x2apic"
43019e3d60dSJan Kiszka	depends on X86_LOCAL_APIC && X86_64 && (IRQ_REMAP || HYPERVISOR_GUEST)
431a7f7f624SMasahiro Yamada	help
43206cd9a7dSYinghai Lu	  This enables x2apic support on CPUs that have this feature.
43306cd9a7dSYinghai Lu
43406cd9a7dSYinghai Lu	  This allows 32-bit apic IDs (so it can support very large systems),
43506cd9a7dSYinghai Lu	  and accesses the local apic via MSRs not via mmio.
43606cd9a7dSYinghai Lu
43706cd9a7dSYinghai Lu	  If you don't know what to do here, say N.
43806cd9a7dSYinghai Lu
4396695c85bSYinghai Luconfig X86_MPPARSE
4406e87f9b7SBin Gao	bool "Enable MPS table" if ACPI || SFI
4417a527688SJan Beulich	default y
4425ab74722SIngo Molnar	depends on X86_LOCAL_APIC
443a7f7f624SMasahiro Yamada	help
4446695c85bSYinghai Lu	  For old smp systems that do not have proper acpi support. Newer systems
4456695c85bSYinghai Lu	  (esp with 64bit cpus) with acpi support, MADT and DSDT will override it
4466695c85bSYinghai Lu
447ddd70cf9SJun Nakajimaconfig GOLDFISH
448ddd70cf9SJun Nakajima	def_bool y
449ddd70cf9SJun Nakajima	depends on X86_GOLDFISH
450ddd70cf9SJun Nakajima
45176b04384SDavid Woodhouseconfig RETPOLINE
45276b04384SDavid Woodhouse	bool "Avoid speculative indirect branches in kernel"
45376b04384SDavid Woodhouse	default y
454d5028ba8SPeter Zijlstra	select STACK_VALIDATION if HAVE_STACK_VALIDATION
45576b04384SDavid Woodhouse	help
45676b04384SDavid Woodhouse	  Compile kernel with the retpoline compiler options to guard against
45776b04384SDavid Woodhouse	  kernel-to-user data leaks by avoiding speculative indirect
45876b04384SDavid Woodhouse	  branches. Requires a compiler with -mindirect-branch=thunk-extern
45976b04384SDavid Woodhouse	  support for full protection. The kernel may run slower.
46076b04384SDavid Woodhouse
461e6d42931SJohannes Weinerconfig X86_CPU_RESCTRL
462e6d42931SJohannes Weiner	bool "x86 CPU resource control support"
4636fe07ce3SBabu Moger	depends on X86 && (CPU_SUP_INTEL || CPU_SUP_AMD)
46459fe5a77SThomas Gleixner	select KERNFS
465e79f15a4SChen Yu	select PROC_CPU_RESCTRL		if PROC_FS
46678e99b4aSFenghua Yu	help
467e6d42931SJohannes Weiner	  Enable x86 CPU resource control support.
4686fe07ce3SBabu Moger
4696fe07ce3SBabu Moger	  Provide support for the allocation and monitoring of system resources
4706fe07ce3SBabu Moger	  usage by the CPU.
4716fe07ce3SBabu Moger
4726fe07ce3SBabu Moger	  Intel calls this Intel Resource Director Technology
4736fe07ce3SBabu Moger	  (Intel(R) RDT). More information about RDT can be found in the
4746fe07ce3SBabu Moger	  Intel x86 Architecture Software Developer Manual.
4756fe07ce3SBabu Moger
4766fe07ce3SBabu Moger	  AMD calls this AMD Platform Quality of Service (AMD QoS).
4776fe07ce3SBabu Moger	  More information about AMD QoS can be found in the AMD64 Technology
4786fe07ce3SBabu Moger	  Platform Quality of Service Extensions manual.
47978e99b4aSFenghua Yu
48078e99b4aSFenghua Yu	  Say N if unsure.
48178e99b4aSFenghua Yu
4828425091fSRavikiran G Thirumalaiif X86_32
483a0d0bb4dSRandy Dunlapconfig X86_BIGSMP
484a0d0bb4dSRandy Dunlap	bool "Support for big SMP systems with more than 8 CPUs"
485a0d0bb4dSRandy Dunlap	depends on SMP
486a7f7f624SMasahiro Yamada	help
487e133f6eaSRandy Dunlap	  This option is needed for the systems that have more than 8 CPUs.
488a0d0bb4dSRandy Dunlap
489c5c606d9SRavikiran G Thirumalaiconfig X86_EXTENDED_PLATFORM
490c5c606d9SRavikiran G Thirumalai	bool "Support for extended (non-PC) x86 platforms"
491c5c606d9SRavikiran G Thirumalai	default y
492a7f7f624SMasahiro Yamada	help
49306ac8346SIngo Molnar	  If you disable this option then the kernel will only support
49406ac8346SIngo Molnar	  standard PC platforms. (which covers the vast majority of
49506ac8346SIngo Molnar	  systems out there.)
49606ac8346SIngo Molnar
4978425091fSRavikiran G Thirumalai	  If you enable this option then you'll be able to select support
4988425091fSRavikiran G Thirumalai	  for the following (non-PC) 32 bit x86 platforms:
499cb7b8023SBen Hutchings		Goldfish (Android emulator)
5008425091fSRavikiran G Thirumalai		AMD Elan
5018425091fSRavikiran G Thirumalai		RDC R-321x SoC
5028425091fSRavikiran G Thirumalai		SGI 320/540 (Visual Workstation)
50383125a3aSAlessandro Rubini		STA2X11-based (e.g. Northville)
5043f4110a4SThomas Gleixner		Moorestown MID devices
50506ac8346SIngo Molnar
50606ac8346SIngo Molnar	  If you have one of these systems, or if you want to build a
50706ac8346SIngo Molnar	  generic distribution kernel, say Y here - otherwise say N.
5088425091fSRavikiran G Thirumalaiendif
50906ac8346SIngo Molnar
5108425091fSRavikiran G Thirumalaiif X86_64
5118425091fSRavikiran G Thirumalaiconfig X86_EXTENDED_PLATFORM
5128425091fSRavikiran G Thirumalai	bool "Support for extended (non-PC) x86 platforms"
5138425091fSRavikiran G Thirumalai	default y
514a7f7f624SMasahiro Yamada	help
5158425091fSRavikiran G Thirumalai	  If you disable this option then the kernel will only support
5168425091fSRavikiran G Thirumalai	  standard PC platforms. (which covers the vast majority of
5178425091fSRavikiran G Thirumalai	  systems out there.)
5188425091fSRavikiran G Thirumalai
5198425091fSRavikiran G Thirumalai	  If you enable this option then you'll be able to select support
5208425091fSRavikiran G Thirumalai	  for the following (non-PC) 64 bit x86 platforms:
52144b111b5SSteffen Persvold		Numascale NumaChip
5228425091fSRavikiran G Thirumalai		ScaleMP vSMP
5238425091fSRavikiran G Thirumalai		SGI Ultraviolet
5248425091fSRavikiran G Thirumalai
5258425091fSRavikiran G Thirumalai	  If you have one of these systems, or if you want to build a
5268425091fSRavikiran G Thirumalai	  generic distribution kernel, say Y here - otherwise say N.
5278425091fSRavikiran G Thirumalaiendif
528c5c606d9SRavikiran G Thirumalai# This is an alphabetically sorted list of 64 bit extended platforms
529c5c606d9SRavikiran G Thirumalai# Please maintain the alphabetic order if and when there are additions
53044b111b5SSteffen Persvoldconfig X86_NUMACHIP
53144b111b5SSteffen Persvold	bool "Numascale NumaChip"
53244b111b5SSteffen Persvold	depends on X86_64
53344b111b5SSteffen Persvold	depends on X86_EXTENDED_PLATFORM
53444b111b5SSteffen Persvold	depends on NUMA
53544b111b5SSteffen Persvold	depends on SMP
53644b111b5SSteffen Persvold	depends on X86_X2APIC
537f9726bfdSDaniel J Blueman	depends on PCI_MMCONFIG
538a7f7f624SMasahiro Yamada	help
53944b111b5SSteffen Persvold	  Adds support for Numascale NumaChip large-SMP systems. Needed to
54044b111b5SSteffen Persvold	  enable more than ~168 cores.
54144b111b5SSteffen Persvold	  If you don't have one of these, you should say N here.
54203b48632SNick Piggin
5436a48565eSIngo Molnarconfig X86_VSMP
544c5c606d9SRavikiran G Thirumalai	bool "ScaleMP vSMP"
5456276a074SBorislav Petkov	select HYPERVISOR_GUEST
5466a48565eSIngo Molnar	select PARAVIRT
5476a48565eSIngo Molnar	depends on X86_64 && PCI
548c5c606d9SRavikiran G Thirumalai	depends on X86_EXTENDED_PLATFORM
549ead91d4bSShai Fultheim	depends on SMP
550a7f7f624SMasahiro Yamada	help
5516a48565eSIngo Molnar	  Support for ScaleMP vSMP systems.  Say 'Y' here if this kernel is
5526a48565eSIngo Molnar	  supposed to run on these EM64T-based machines.  Only choose this option
5536a48565eSIngo Molnar	  if you have one of these machines.
5546a48565eSIngo Molnar
555c5c606d9SRavikiran G Thirumalaiconfig X86_UV
556c5c606d9SRavikiran G Thirumalai	bool "SGI Ultraviolet"
557c5c606d9SRavikiran G Thirumalai	depends on X86_64
558c5c606d9SRavikiran G Thirumalai	depends on X86_EXTENDED_PLATFORM
55954c28d29SJack Steiner	depends on NUMA
5601ecb4ae5SAndrew Morton	depends on EFI
5619d6c26e7SSuresh Siddha	depends on X86_X2APIC
5621222e564SIngo Molnar	depends on PCI
563a7f7f624SMasahiro Yamada	help
564c5c606d9SRavikiran G Thirumalai	  This option is needed in order to support SGI Ultraviolet systems.
565c5c606d9SRavikiran G Thirumalai	  If you don't have one of these, you should say N here.
566c5c606d9SRavikiran G Thirumalai
567c5c606d9SRavikiran G Thirumalai# Following is an alphabetically sorted list of 32 bit extended platforms
568c5c606d9SRavikiran G Thirumalai# Please maintain the alphabetic order if and when there are additions
569506f1d07SSam Ravnborg
570ddd70cf9SJun Nakajimaconfig X86_GOLDFISH
571ddd70cf9SJun Nakajima	bool "Goldfish (Virtual Platform)"
572cb7b8023SBen Hutchings	depends on X86_EXTENDED_PLATFORM
573a7f7f624SMasahiro Yamada	help
574ddd70cf9SJun Nakajima	 Enable support for the Goldfish virtual platform used primarily
575ddd70cf9SJun Nakajima	 for Android development. Unless you are building for the Android
576ddd70cf9SJun Nakajima	 Goldfish emulator say N here.
577ddd70cf9SJun Nakajima
578c751e17bSThomas Gleixnerconfig X86_INTEL_CE
579c751e17bSThomas Gleixner	bool "CE4100 TV platform"
580c751e17bSThomas Gleixner	depends on PCI
581c751e17bSThomas Gleixner	depends on PCI_GODIRECT
5826084a6e2SJiang Liu	depends on X86_IO_APIC
583c751e17bSThomas Gleixner	depends on X86_32
584c751e17bSThomas Gleixner	depends on X86_EXTENDED_PLATFORM
58537bc9f50SDirk Brandewie	select X86_REBOOTFIXUPS
586da6b737bSSebastian Andrzej Siewior	select OF
587da6b737bSSebastian Andrzej Siewior	select OF_EARLY_FLATTREE
588a7f7f624SMasahiro Yamada	help
589c751e17bSThomas Gleixner	  Select for the Intel CE media processor (CE4100) SOC.
590c751e17bSThomas Gleixner	  This option compiles in support for the CE4100 SOC for settop
591c751e17bSThomas Gleixner	  boxes and media devices.
592c751e17bSThomas Gleixner
5934cb9b00fSDavid Cohenconfig X86_INTEL_MID
59443605ef1SAlan Cox	bool "Intel MID platform support"
59543605ef1SAlan Cox	depends on X86_EXTENDED_PLATFORM
596edc6bc78SDavid Cohen	depends on X86_PLATFORM_DEVICES
5971ea7c673SAlan Cox	depends on PCI
5983fda5bb4SAndy Shevchenko	depends on X86_64 || (PCI_GOANY && X86_32)
5991ea7c673SAlan Cox	depends on X86_IO_APIC
6007c9c3a1eSAlan Cox	select SFI
6014cb9b00fSDavid Cohen	select I2C
6027c9c3a1eSAlan Cox	select DW_APB_TIMER
6031ea7c673SAlan Cox	select APB_TIMER
60454b34aa0SMika Westerberg	select INTEL_SCU_PCI
60515a713dfSMika Westerberg	select MFD_INTEL_MSIC
606a7f7f624SMasahiro Yamada	help
6074cb9b00fSDavid Cohen	  Select to build a kernel capable of supporting Intel MID (Mobile
6084cb9b00fSDavid Cohen	  Internet Device) platform systems which do not have the PCI legacy
6094cb9b00fSDavid Cohen	  interfaces. If you are building for a PC class system say N here.
6101ea7c673SAlan Cox
6114cb9b00fSDavid Cohen	  Intel MID platforms are based on an Intel processor and chipset which
6124cb9b00fSDavid Cohen	  consume less power than most of the x86 derivatives.
61343605ef1SAlan Cox
6148bbc2a13SBryan O'Donoghueconfig X86_INTEL_QUARK
6158bbc2a13SBryan O'Donoghue	bool "Intel Quark platform support"
6168bbc2a13SBryan O'Donoghue	depends on X86_32
6178bbc2a13SBryan O'Donoghue	depends on X86_EXTENDED_PLATFORM
6188bbc2a13SBryan O'Donoghue	depends on X86_PLATFORM_DEVICES
6198bbc2a13SBryan O'Donoghue	depends on X86_TSC
6208bbc2a13SBryan O'Donoghue	depends on PCI
6218bbc2a13SBryan O'Donoghue	depends on PCI_GOANY
6228bbc2a13SBryan O'Donoghue	depends on X86_IO_APIC
6238bbc2a13SBryan O'Donoghue	select IOSF_MBI
6248bbc2a13SBryan O'Donoghue	select INTEL_IMR
6259ab6eb51SAndy Shevchenko	select COMMON_CLK
626a7f7f624SMasahiro Yamada	help
6278bbc2a13SBryan O'Donoghue	  Select to include support for Quark X1000 SoC.
6288bbc2a13SBryan O'Donoghue	  Say Y here if you have a Quark based system such as the Arduino
6298bbc2a13SBryan O'Donoghue	  compatible Intel Galileo.
6308bbc2a13SBryan O'Donoghue
6313d48aab1SMika Westerbergconfig X86_INTEL_LPSS
6323d48aab1SMika Westerberg	bool "Intel Low Power Subsystem Support"
6335962dd22SSinan Kaya	depends on X86 && ACPI && PCI
6343d48aab1SMika Westerberg	select COMMON_CLK
6350f531431SMathias Nyman	select PINCTRL
636eebb3e8dSAndy Shevchenko	select IOSF_MBI
637a7f7f624SMasahiro Yamada	help
6383d48aab1SMika Westerberg	  Select to build support for Intel Low Power Subsystem such as
6393d48aab1SMika Westerberg	  found on Intel Lynxpoint PCH. Selecting this option enables
6400f531431SMathias Nyman	  things like clock tree (common clock framework) and pincontrol
6410f531431SMathias Nyman	  which are needed by the LPSS peripheral drivers.
6423d48aab1SMika Westerberg
64392082a88SKen Xueconfig X86_AMD_PLATFORM_DEVICE
64492082a88SKen Xue	bool "AMD ACPI2Platform devices support"
64592082a88SKen Xue	depends on ACPI
64692082a88SKen Xue	select COMMON_CLK
64792082a88SKen Xue	select PINCTRL
648a7f7f624SMasahiro Yamada	help
64992082a88SKen Xue	  Select to interpret AMD specific ACPI device to platform device
65092082a88SKen Xue	  such as I2C, UART, GPIO found on AMD Carrizo and later chipsets.
65192082a88SKen Xue	  I2C and UART depend on COMMON_CLK to set clock. GPIO driver is
65292082a88SKen Xue	  implemented under PINCTRL subsystem.
65392082a88SKen Xue
654ced3ce76SDavid E. Boxconfig IOSF_MBI
655ced3ce76SDavid E. Box	tristate "Intel SoC IOSF Sideband support for SoC platforms"
656ced3ce76SDavid E. Box	depends on PCI
657a7f7f624SMasahiro Yamada	help
658ced3ce76SDavid E. Box	  This option enables sideband register access support for Intel SoC
659ced3ce76SDavid E. Box	  platforms. On these platforms the IOSF sideband is used in lieu of
660ced3ce76SDavid E. Box	  MSR's for some register accesses, mostly but not limited to thermal
661ced3ce76SDavid E. Box	  and power. Drivers may query the availability of this device to
662ced3ce76SDavid E. Box	  determine if they need the sideband in order to work on these
663ced3ce76SDavid E. Box	  platforms. The sideband is available on the following SoC products.
664ced3ce76SDavid E. Box	  This list is not meant to be exclusive.
665ced3ce76SDavid E. Box	   - BayTrail
666ced3ce76SDavid E. Box	   - Braswell
667ced3ce76SDavid E. Box	   - Quark
668ced3ce76SDavid E. Box
669ced3ce76SDavid E. Box	  You should say Y if you are running a kernel on one of these SoC's.
670ced3ce76SDavid E. Box
671ed2226bdSDavid E. Boxconfig IOSF_MBI_DEBUG
672ed2226bdSDavid E. Box	bool "Enable IOSF sideband access through debugfs"
673ed2226bdSDavid E. Box	depends on IOSF_MBI && DEBUG_FS
674a7f7f624SMasahiro Yamada	help
675ed2226bdSDavid E. Box	  Select this option to expose the IOSF sideband access registers (MCR,
676ed2226bdSDavid E. Box	  MDR, MCRX) through debugfs to write and read register information from
677ed2226bdSDavid E. Box	  different units on the SoC. This is most useful for obtaining device
678ed2226bdSDavid E. Box	  state information for debug and analysis. As this is a general access
679ed2226bdSDavid E. Box	  mechanism, users of this option would have specific knowledge of the
680ed2226bdSDavid E. Box	  device they want to access.
681ed2226bdSDavid E. Box
682ed2226bdSDavid E. Box	  If you don't require the option or are in doubt, say N.
683ed2226bdSDavid E. Box
684c5c606d9SRavikiran G Thirumalaiconfig X86_RDC321X
685c5c606d9SRavikiran G Thirumalai	bool "RDC R-321x SoC"
686506f1d07SSam Ravnborg	depends on X86_32
687c5c606d9SRavikiran G Thirumalai	depends on X86_EXTENDED_PLATFORM
688c5c606d9SRavikiran G Thirumalai	select M486
689c5c606d9SRavikiran G Thirumalai	select X86_REBOOTFIXUPS
690a7f7f624SMasahiro Yamada	help
691c5c606d9SRavikiran G Thirumalai	  This option is needed for RDC R-321x system-on-chip, also known
692c5c606d9SRavikiran G Thirumalai	  as R-8610-(G).
693c5c606d9SRavikiran G Thirumalai	  If you don't have one of these chips, you should say N here.
694c5c606d9SRavikiran G Thirumalai
695e0c7ae37SIngo Molnarconfig X86_32_NON_STANDARD
6969c398017SIngo Molnar	bool "Support non-standard 32-bit SMP architectures"
6979c398017SIngo Molnar	depends on X86_32 && SMP
698c5c606d9SRavikiran G Thirumalai	depends on X86_EXTENDED_PLATFORM
699a7f7f624SMasahiro Yamada	help
700b5660ba7SH. Peter Anvin	  This option compiles in the bigsmp and STA2X11 default
701b5660ba7SH. Peter Anvin	  subarchitectures.  It is intended for a generic binary
702b5660ba7SH. Peter Anvin	  kernel. If you select them all, kernel will probe it one by
703b5660ba7SH. Peter Anvin	  one and will fallback to default.
704d49c4288SYinghai Lu
705c5c606d9SRavikiran G Thirumalai# Alphabetically sorted list of Non standard 32 bit platforms
706d49c4288SYinghai Lu
707d949f36fSLinus Torvaldsconfig X86_SUPPORTS_MEMORY_FAILURE
7086fc108a0SJan Beulich	def_bool y
709d949f36fSLinus Torvalds	# MCE code calls memory_failure():
710d949f36fSLinus Torvalds	depends on X86_MCE
711d949f36fSLinus Torvalds	# On 32-bit this adds too big of NODES_SHIFT and we run out of page flags:
712d949f36fSLinus Torvalds	# On 32-bit SPARSEMEM adds too big of SECTIONS_WIDTH:
713d949f36fSLinus Torvalds	depends on X86_64 || !SPARSEMEM
714d949f36fSLinus Torvalds	select ARCH_SUPPORTS_MEMORY_FAILURE
715d949f36fSLinus Torvalds
71683125a3aSAlessandro Rubiniconfig STA2X11
71783125a3aSAlessandro Rubini	bool "STA2X11 Companion Chip Support"
71883125a3aSAlessandro Rubini	depends on X86_32_NON_STANDARD && PCI
71983125a3aSAlessandro Rubini	select SWIOTLB
72083125a3aSAlessandro Rubini	select MFD_STA2X11
7210145071bSLinus Walleij	select GPIOLIB
722a7f7f624SMasahiro Yamada	help
72383125a3aSAlessandro Rubini	  This adds support for boards based on the STA2X11 IO-Hub,
72483125a3aSAlessandro Rubini	  a.k.a. "ConneXt". The chip is used in place of the standard
72583125a3aSAlessandro Rubini	  PC chipset, so all "standard" peripherals are missing. If this
72683125a3aSAlessandro Rubini	  option is selected the kernel will still be able to boot on
72783125a3aSAlessandro Rubini	  standard PC machines.
72883125a3aSAlessandro Rubini
72982148d1dSShérabconfig X86_32_IRIS
73082148d1dSShérab	tristate "Eurobraille/Iris poweroff module"
73182148d1dSShérab	depends on X86_32
732a7f7f624SMasahiro Yamada	help
73382148d1dSShérab	  The Iris machines from EuroBraille do not have APM or ACPI support
73482148d1dSShérab	  to shut themselves down properly.  A special I/O sequence is
73582148d1dSShérab	  needed to do so, which is what this module does at
73682148d1dSShérab	  kernel shutdown.
73782148d1dSShérab
73882148d1dSShérab	  This is only for Iris machines from EuroBraille.
73982148d1dSShérab
74082148d1dSShérab	  If unused, say N.
74182148d1dSShérab
742ae1e9130SIngo Molnarconfig SCHED_OMIT_FRAME_POINTER
7433c2362e6SHarvey Harrison	def_bool y
7443c2362e6SHarvey Harrison	prompt "Single-depth WCHAN output"
745a87d0914SKen Chen	depends on X86
746a7f7f624SMasahiro Yamada	help
747506f1d07SSam Ravnborg	  Calculate simpler /proc/<PID>/wchan values. If this option
748506f1d07SSam Ravnborg	  is disabled then wchan values will recurse back to the
749506f1d07SSam Ravnborg	  caller function. This provides more accurate wchan values,
750506f1d07SSam Ravnborg	  at the expense of slightly more scheduling overhead.
751506f1d07SSam Ravnborg
752506f1d07SSam Ravnborg	  If in doubt, say "Y".
753506f1d07SSam Ravnborg
7546276a074SBorislav Petkovmenuconfig HYPERVISOR_GUEST
7556276a074SBorislav Petkov	bool "Linux guest support"
756a7f7f624SMasahiro Yamada	help
7576276a074SBorislav Petkov	  Say Y here to enable options for running Linux under various hyper-
7586276a074SBorislav Petkov	  visors. This option enables basic hypervisor detection and platform
7596276a074SBorislav Petkov	  setup.
760506f1d07SSam Ravnborg
7616276a074SBorislav Petkov	  If you say N, all options in this submenu will be skipped and
7626276a074SBorislav Petkov	  disabled, and Linux guest support won't be built in.
763506f1d07SSam Ravnborg
7646276a074SBorislav Petkovif HYPERVISOR_GUEST
765506f1d07SSam Ravnborg
766e61bd94aSEduardo Pereira Habkostconfig PARAVIRT
767e61bd94aSEduardo Pereira Habkost	bool "Enable paravirtualization code"
768a7f7f624SMasahiro Yamada	help
769e61bd94aSEduardo Pereira Habkost	  This changes the kernel so it can modify itself when it is run
770e61bd94aSEduardo Pereira Habkost	  under a hypervisor, potentially improving performance significantly
771e61bd94aSEduardo Pereira Habkost	  over full virtualization.  However, when run without a hypervisor
772e61bd94aSEduardo Pereira Habkost	  the kernel is theoretically slower and slightly larger.
773e61bd94aSEduardo Pereira Habkost
774c00a280aSJuergen Grossconfig PARAVIRT_XXL
775c00a280aSJuergen Gross	bool
776c00a280aSJuergen Gross
7776276a074SBorislav Petkovconfig PARAVIRT_DEBUG
7786276a074SBorislav Petkov	bool "paravirt-ops debugging"
7796276a074SBorislav Petkov	depends on PARAVIRT && DEBUG_KERNEL
780a7f7f624SMasahiro Yamada	help
7816276a074SBorislav Petkov	  Enable to debug paravirt_ops internals.  Specifically, BUG if
7826276a074SBorislav Petkov	  a paravirt_op is missing when it is called.
7836276a074SBorislav Petkov
784b4ecc126SJeremy Fitzhardingeconfig PARAVIRT_SPINLOCKS
785b4ecc126SJeremy Fitzhardinge	bool "Paravirtualization layer for spinlocks"
7866ea30386SKees Cook	depends on PARAVIRT && SMP
787a7f7f624SMasahiro Yamada	help
788b4ecc126SJeremy Fitzhardinge	  Paravirtualized spinlocks allow a pvops backend to replace the
789b4ecc126SJeremy Fitzhardinge	  spinlock implementation with something virtualization-friendly
790b4ecc126SJeremy Fitzhardinge	  (for example, block the virtual CPU rather than spinning).
791b4ecc126SJeremy Fitzhardinge
7924c4e4f61SRaghavendra K T	  It has a minimal impact on native kernels and gives a nice performance
7934c4e4f61SRaghavendra K T	  benefit on paravirtualized KVM / Xen kernels.
794b4ecc126SJeremy Fitzhardinge
7954c4e4f61SRaghavendra K T	  If you are unsure how to answer this question, answer Y.
796b4ecc126SJeremy Fitzhardinge
797ecca2502SZhao Yakuiconfig X86_HV_CALLBACK_VECTOR
798ecca2502SZhao Yakui	def_bool n
799ecca2502SZhao Yakui
8006276a074SBorislav Petkovsource "arch/x86/xen/Kconfig"
8016276a074SBorislav Petkov
8026276a074SBorislav Petkovconfig KVM_GUEST
8036276a074SBorislav Petkov	bool "KVM Guest support (including kvmclock)"
8046276a074SBorislav Petkov	depends on PARAVIRT
8056276a074SBorislav Petkov	select PARAVIRT_CLOCK
806a1c4423bSMarcelo Tosatti	select ARCH_CPUIDLE_HALTPOLL
807b1d40575SVitaly Kuznetsov	select X86_HV_CALLBACK_VECTOR
8086276a074SBorislav Petkov	default y
809a7f7f624SMasahiro Yamada	help
8106276a074SBorislav Petkov	  This option enables various optimizations for running under the KVM
8116276a074SBorislav Petkov	  hypervisor. It includes a paravirtualized clock, so that instead
8126276a074SBorislav Petkov	  of relying on a PIT (or probably other) emulation by the
8136276a074SBorislav Petkov	  underlying device model, the host provides the guest with
8146276a074SBorislav Petkov	  timing infrastructure such as time of day, and system time
8156276a074SBorislav Petkov
816a1c4423bSMarcelo Tosatticonfig ARCH_CPUIDLE_HALTPOLL
817a1c4423bSMarcelo Tosatti	def_bool n
818a1c4423bSMarcelo Tosatti	prompt "Disable host haltpoll when loading haltpoll driver"
819a1c4423bSMarcelo Tosatti	help
820a1c4423bSMarcelo Tosatti	  If virtualized under KVM, disable host haltpoll.
821a1c4423bSMarcelo Tosatti
8227733607fSMaran Wilsonconfig PVH
8237733607fSMaran Wilson	bool "Support for running PVH guests"
824a7f7f624SMasahiro Yamada	help
8257733607fSMaran Wilson	  This option enables the PVH entry point for guest virtual machines
8267733607fSMaran Wilson	  as specified in the x86/HVM direct boot ABI.
8277733607fSMaran Wilson
8286276a074SBorislav Petkovconfig PARAVIRT_TIME_ACCOUNTING
8296276a074SBorislav Petkov	bool "Paravirtual steal time accounting"
8306276a074SBorislav Petkov	depends on PARAVIRT
831a7f7f624SMasahiro Yamada	help
8326276a074SBorislav Petkov	  Select this option to enable fine granularity task steal time
8336276a074SBorislav Petkov	  accounting. Time spent executing other tasks in parallel with
8346276a074SBorislav Petkov	  the current vCPU is discounted from the vCPU power. To account for
8356276a074SBorislav Petkov	  that, there can be a small performance impact.
8366276a074SBorislav Petkov
8376276a074SBorislav Petkov	  If in doubt, say N here.
8386276a074SBorislav Petkov
8397af192c9SGerd Hoffmannconfig PARAVIRT_CLOCK
8407af192c9SGerd Hoffmann	bool
8417af192c9SGerd Hoffmann
8424a362601SJan Kiszkaconfig JAILHOUSE_GUEST
8434a362601SJan Kiszka	bool "Jailhouse non-root cell support"
844abde587bSArnd Bergmann	depends on X86_64 && PCI
84587e65d05SJan Kiszka	select X86_PM_TIMER
846a7f7f624SMasahiro Yamada	help
8474a362601SJan Kiszka	  This option allows to run Linux as guest in a Jailhouse non-root
8484a362601SJan Kiszka	  cell. You can leave this option disabled if you only want to start
8494a362601SJan Kiszka	  Jailhouse and run Linux afterwards in the root cell.
8504a362601SJan Kiszka
851ec7972c9SZhao Yakuiconfig ACRN_GUEST
852ec7972c9SZhao Yakui	bool "ACRN Guest support"
853ec7972c9SZhao Yakui	depends on X86_64
854498ad393SZhao Yakui	select X86_HV_CALLBACK_VECTOR
855ec7972c9SZhao Yakui	help
856ec7972c9SZhao Yakui	  This option allows to run Linux as guest in the ACRN hypervisor. ACRN is
857ec7972c9SZhao Yakui	  a flexible, lightweight reference open-source hypervisor, built with
858ec7972c9SZhao Yakui	  real-time and safety-criticality in mind. It is built for embedded
859ec7972c9SZhao Yakui	  IOT with small footprint and real-time features. More details can be
860ec7972c9SZhao Yakui	  found in https://projectacrn.org/.
861ec7972c9SZhao Yakui
8626276a074SBorislav Petkovendif #HYPERVISOR_GUEST
86397349135SJeremy Fitzhardinge
864506f1d07SSam Ravnborgsource "arch/x86/Kconfig.cpu"
865506f1d07SSam Ravnborg
866506f1d07SSam Ravnborgconfig HPET_TIMER
8673c2362e6SHarvey Harrison	def_bool X86_64
868506f1d07SSam Ravnborg	prompt "HPET Timer Support" if X86_32
869a7f7f624SMasahiro Yamada	help
870506f1d07SSam Ravnborg	  Use the IA-PC HPET (High Precision Event Timer) to manage
871506f1d07SSam Ravnborg	  time in preference to the PIT and RTC, if a HPET is
872506f1d07SSam Ravnborg	  present.
873506f1d07SSam Ravnborg	  HPET is the next generation timer replacing legacy 8254s.
874506f1d07SSam Ravnborg	  The HPET provides a stable time base on SMP
875506f1d07SSam Ravnborg	  systems, unlike the TSC, but it is more expensive to access,
8764e7f9df2SMichael S. Tsirkin	  as it is off-chip.  The interface used is documented
8774e7f9df2SMichael S. Tsirkin	  in the HPET spec, revision 1.
878506f1d07SSam Ravnborg
879506f1d07SSam Ravnborg	  You can safely choose Y here.  However, HPET will only be
880506f1d07SSam Ravnborg	  activated if the platform and the BIOS support this feature.
881506f1d07SSam Ravnborg	  Otherwise the 8254 will be used for timing services.
882506f1d07SSam Ravnborg
883506f1d07SSam Ravnborg	  Choose N to continue using the legacy 8254 timer.
884506f1d07SSam Ravnborg
885506f1d07SSam Ravnborgconfig HPET_EMULATE_RTC
8863c2362e6SHarvey Harrison	def_bool y
8879d8af78bSBernhard Walle	depends on HPET_TIMER && (RTC=y || RTC=m || RTC_DRV_CMOS=m || RTC_DRV_CMOS=y)
888506f1d07SSam Ravnborg
889bb24c471SJacob Panconfig APB_TIMER
890933b9463SAlan Cox	def_bool y if X86_INTEL_MID
891933b9463SAlan Cox	prompt "Intel MID APB Timer Support" if X86_INTEL_MID
89206c3df49SJamie Iles	select DW_APB_TIMER
893a0c3832aSAlan Cox	depends on X86_INTEL_MID && SFI
894bb24c471SJacob Pan	help
895bb24c471SJacob Pan	 APB timer is the replacement for 8254, HPET on X86 MID platforms.
896bb24c471SJacob Pan	 The APBT provides a stable time base on SMP
897bb24c471SJacob Pan	 systems, unlike the TSC, but it is more expensive to access,
898bb24c471SJacob Pan	 as it is off-chip. APB timers are always running regardless of CPU
899bb24c471SJacob Pan	 C states, they are used as per CPU clockevent device when possible.
900bb24c471SJacob Pan
9016a108a14SDavid Rientjes# Mark as expert because too many people got it wrong.
902506f1d07SSam Ravnborg# The code disables itself when not needed.
9037ae9392cSThomas Petazzoniconfig DMI
9047ae9392cSThomas Petazzoni	default y
905cf074402SArd Biesheuvel	select DMI_SCAN_MACHINE_NON_EFI_FALLBACK
9066a108a14SDavid Rientjes	bool "Enable DMI scanning" if EXPERT
907a7f7f624SMasahiro Yamada	help
9087ae9392cSThomas Petazzoni	  Enabled scanning of DMI to identify machine quirks. Say Y
9097ae9392cSThomas Petazzoni	  here unless you have verified that your setup is not
9107ae9392cSThomas Petazzoni	  affected by entries in the DMI blacklist. Required by PNP
9117ae9392cSThomas Petazzoni	  BIOS code.
9127ae9392cSThomas Petazzoni
913506f1d07SSam Ravnborgconfig GART_IOMMU
91438901f1cSAndi Kleen	bool "Old AMD GART IOMMU support"
9152f9237d4SChristoph Hellwig	select DMA_OPS
916a4ce5a48SChristoph Hellwig	select IOMMU_HELPER
917506f1d07SSam Ravnborg	select SWIOTLB
91823ac4ae8SAndreas Herrmann	depends on X86_64 && PCI && AMD_NB
919a7f7f624SMasahiro Yamada	help
920ced3c42cSIngo Molnar	  Provides a driver for older AMD Athlon64/Opteron/Turion/Sempron
921ced3c42cSIngo Molnar	  GART based hardware IOMMUs.
922ced3c42cSIngo Molnar
923ced3c42cSIngo Molnar	  The GART supports full DMA access for devices with 32-bit access
924ced3c42cSIngo Molnar	  limitations, on systems with more than 3 GB. This is usually needed
925ced3c42cSIngo Molnar	  for USB, sound, many IDE/SATA chipsets and some other devices.
926ced3c42cSIngo Molnar
927ced3c42cSIngo Molnar	  Newer systems typically have a modern AMD IOMMU, supported via
928ced3c42cSIngo Molnar	  the CONFIG_AMD_IOMMU=y config option.
929ced3c42cSIngo Molnar
930ced3c42cSIngo Molnar	  In normal configurations this driver is only active when needed:
931ced3c42cSIngo Molnar	  there's more than 3 GB of memory and the system contains a
932ced3c42cSIngo Molnar	  32-bit limited device.
933ced3c42cSIngo Molnar
934ced3c42cSIngo Molnar	  If unsure, say Y.
935506f1d07SSam Ravnborg
9361184dc2fSMike Travisconfig MAXSMP
937ddb0c5a6SSamuel Thibault	bool "Enable Maximum number of SMP Processors and NUMA Nodes"
9386ea30386SKees Cook	depends on X86_64 && SMP && DEBUG_KERNEL
93936f5101aSMike Travis	select CPUMASK_OFFSTACK
940a7f7f624SMasahiro Yamada	help
941ddb0c5a6SSamuel Thibault	  Enable maximum number of CPUS and NUMA Nodes for this architecture.
9421184dc2fSMike Travis	  If unsure, say N.
943506f1d07SSam Ravnborg
944aec6487eSIngo Molnar#
945aec6487eSIngo Molnar# The maximum number of CPUs supported:
946aec6487eSIngo Molnar#
947aec6487eSIngo Molnar# The main config value is NR_CPUS, which defaults to NR_CPUS_DEFAULT,
948aec6487eSIngo Molnar# and which can be configured interactively in the
949aec6487eSIngo Molnar# [NR_CPUS_RANGE_BEGIN ... NR_CPUS_RANGE_END] range.
950aec6487eSIngo Molnar#
951aec6487eSIngo Molnar# The ranges are different on 32-bit and 64-bit kernels, depending on
952aec6487eSIngo Molnar# hardware capabilities and scalability features of the kernel.
953aec6487eSIngo Molnar#
954aec6487eSIngo Molnar# ( If MAXSMP is enabled we just use the highest possible value and disable
955aec6487eSIngo Molnar#   interactive configuration. )
956aec6487eSIngo Molnar#
957a0d0bb4dSRandy Dunlap
958aec6487eSIngo Molnarconfig NR_CPUS_RANGE_BEGIN
959a0d0bb4dSRandy Dunlap	int
960aec6487eSIngo Molnar	default NR_CPUS_RANGE_END if MAXSMP
961a0d0bb4dSRandy Dunlap	default    1 if !SMP
962a0d0bb4dSRandy Dunlap	default    2
963a0d0bb4dSRandy Dunlap
964aec6487eSIngo Molnarconfig NR_CPUS_RANGE_END
965a0d0bb4dSRandy Dunlap	int
966a0d0bb4dSRandy Dunlap	depends on X86_32
967aec6487eSIngo Molnar	default   64 if  SMP &&  X86_BIGSMP
968aec6487eSIngo Molnar	default    8 if  SMP && !X86_BIGSMP
969a0d0bb4dSRandy Dunlap	default    1 if !SMP
970a0d0bb4dSRandy Dunlap
971aec6487eSIngo Molnarconfig NR_CPUS_RANGE_END
972a0d0bb4dSRandy Dunlap	int
973a0d0bb4dSRandy Dunlap	depends on X86_64
9741edae1aeSScott Wood	default 8192 if  SMP && CPUMASK_OFFSTACK
9751edae1aeSScott Wood	default  512 if  SMP && !CPUMASK_OFFSTACK
976a0d0bb4dSRandy Dunlap	default    1 if !SMP
977aec6487eSIngo Molnar
978aec6487eSIngo Molnarconfig NR_CPUS_DEFAULT
979aec6487eSIngo Molnar	int
980aec6487eSIngo Molnar	depends on X86_32
981aec6487eSIngo Molnar	default   32 if  X86_BIGSMP
982aec6487eSIngo Molnar	default    8 if  SMP
983aec6487eSIngo Molnar	default    1 if !SMP
984aec6487eSIngo Molnar
985aec6487eSIngo Molnarconfig NR_CPUS_DEFAULT
986aec6487eSIngo Molnar	int
987aec6487eSIngo Molnar	depends on X86_64
988a0d0bb4dSRandy Dunlap	default 8192 if  MAXSMP
989a0d0bb4dSRandy Dunlap	default   64 if  SMP
990aec6487eSIngo Molnar	default    1 if !SMP
991a0d0bb4dSRandy Dunlap
992506f1d07SSam Ravnborgconfig NR_CPUS
99336f5101aSMike Travis	int "Maximum number of CPUs" if SMP && !MAXSMP
994aec6487eSIngo Molnar	range NR_CPUS_RANGE_BEGIN NR_CPUS_RANGE_END
995aec6487eSIngo Molnar	default NR_CPUS_DEFAULT
996a7f7f624SMasahiro Yamada	help
997506f1d07SSam Ravnborg	  This allows you to specify the maximum number of CPUs which this
998bb61ccc7SJosh Boyer	  kernel will support.  If CPUMASK_OFFSTACK is enabled, the maximum
999cad14bb9SKirill A. Shutemov	  supported value is 8192, otherwise the maximum value is 512.  The
1000506f1d07SSam Ravnborg	  minimum value which makes sense is 2.
1001506f1d07SSam Ravnborg
1002aec6487eSIngo Molnar	  This is purely to save memory: each supported CPU adds about 8KB
1003aec6487eSIngo Molnar	  to the kernel image.
1004506f1d07SSam Ravnborg
1005506f1d07SSam Ravnborgconfig SCHED_SMT
1006dbe73364SThomas Gleixner	def_bool y if SMP
1007506f1d07SSam Ravnborg
1008506f1d07SSam Ravnborgconfig SCHED_MC
10093c2362e6SHarvey Harrison	def_bool y
10103c2362e6SHarvey Harrison	prompt "Multi-core scheduler support"
1011c8e56d20SBorislav Petkov	depends on SMP
1012a7f7f624SMasahiro Yamada	help
1013506f1d07SSam Ravnborg	  Multi-core scheduler support improves the CPU scheduler's decision
1014506f1d07SSam Ravnborg	  making when dealing with multi-core CPU chips at a cost of slightly
1015506f1d07SSam Ravnborg	  increased overhead in some places. If unsure say N here.
1016506f1d07SSam Ravnborg
1017de966cf4STim Chenconfig SCHED_MC_PRIO
1018de966cf4STim Chen	bool "CPU core priorities scheduler support"
10190a21fc12SIngo Molnar	depends on SCHED_MC && CPU_SUP_INTEL
10200a21fc12SIngo Molnar	select X86_INTEL_PSTATE
10210a21fc12SIngo Molnar	select CPU_FREQ
1022de966cf4STim Chen	default y
1023a7f7f624SMasahiro Yamada	help
1024de966cf4STim Chen	  Intel Turbo Boost Max Technology 3.0 enabled CPUs have a
1025de966cf4STim Chen	  core ordering determined at manufacturing time, which allows
1026de966cf4STim Chen	  certain cores to reach higher turbo frequencies (when running
1027de966cf4STim Chen	  single threaded workloads) than others.
1028de966cf4STim Chen
1029de966cf4STim Chen	  Enabling this kernel feature teaches the scheduler about
1030de966cf4STim Chen	  the TBM3 (aka ITMT) priority order of the CPU cores and adjusts the
1031de966cf4STim Chen	  scheduler's CPU selection logic accordingly, so that higher
1032de966cf4STim Chen	  overall system performance can be achieved.
1033de966cf4STim Chen
1034de966cf4STim Chen	  This feature will have no effect on CPUs without this feature.
1035de966cf4STim Chen
1036de966cf4STim Chen	  If unsure say Y here.
10375e76b2abSTim Chen
103830b8b006SThomas Gleixnerconfig UP_LATE_INIT
103930b8b006SThomas Gleixner	def_bool y
1040ba360f88SThomas Gleixner	depends on !SMP && X86_LOCAL_APIC
104130b8b006SThomas Gleixner
1042506f1d07SSam Ravnborgconfig X86_UP_APIC
104350849eefSJan Beulich	bool "Local APIC support on uniprocessors" if !PCI_MSI
104450849eefSJan Beulich	default PCI_MSI
104538a1dfdaSBryan O'Donoghue	depends on X86_32 && !SMP && !X86_32_NON_STANDARD
1046a7f7f624SMasahiro Yamada	help
1047506f1d07SSam Ravnborg	  A local APIC (Advanced Programmable Interrupt Controller) is an
1048506f1d07SSam Ravnborg	  integrated interrupt controller in the CPU. If you have a single-CPU
1049506f1d07SSam Ravnborg	  system which has a processor with a local APIC, you can say Y here to
1050506f1d07SSam Ravnborg	  enable and use it. If you say Y here even though your machine doesn't
1051506f1d07SSam Ravnborg	  have a local APIC, then the kernel will still run with no slowdown at
1052506f1d07SSam Ravnborg	  all. The local APIC supports CPU-generated self-interrupts (timer,
1053506f1d07SSam Ravnborg	  performance counters), and the NMI watchdog which detects hard
1054506f1d07SSam Ravnborg	  lockups.
1055506f1d07SSam Ravnborg
1056506f1d07SSam Ravnborgconfig X86_UP_IOAPIC
1057506f1d07SSam Ravnborg	bool "IO-APIC support on uniprocessors"
1058506f1d07SSam Ravnborg	depends on X86_UP_APIC
1059a7f7f624SMasahiro Yamada	help
1060506f1d07SSam Ravnborg	  An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an
1061506f1d07SSam Ravnborg	  SMP-capable replacement for PC-style interrupt controllers. Most
1062506f1d07SSam Ravnborg	  SMP systems and many recent uniprocessor systems have one.
1063506f1d07SSam Ravnborg
1064506f1d07SSam Ravnborg	  If you have a single-CPU system with an IO-APIC, you can say Y here
1065506f1d07SSam Ravnborg	  to use it. If you say Y here even though your machine doesn't have
1066506f1d07SSam Ravnborg	  an IO-APIC, then the kernel will still run with no slowdown at all.
1067506f1d07SSam Ravnborg
1068506f1d07SSam Ravnborgconfig X86_LOCAL_APIC
10693c2362e6SHarvey Harrison	def_bool y
10700dbc6078SThomas Petazzoni	depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC || PCI_MSI
1071b5dc8e6cSJiang Liu	select IRQ_DOMAIN_HIERARCHY
107252f518a3SJiang Liu	select PCI_MSI_IRQ_DOMAIN if PCI_MSI
1073506f1d07SSam Ravnborg
1074506f1d07SSam Ravnborgconfig X86_IO_APIC
1075b1da1e71SJan Beulich	def_bool y
1076b1da1e71SJan Beulich	depends on X86_LOCAL_APIC || X86_UP_IOAPIC
1077506f1d07SSam Ravnborg
107841b9eb26SStefan Assmannconfig X86_REROUTE_FOR_BROKEN_BOOT_IRQS
107941b9eb26SStefan Assmann	bool "Reroute for broken boot IRQs"
108041b9eb26SStefan Assmann	depends on X86_IO_APIC
1081a7f7f624SMasahiro Yamada	help
108241b9eb26SStefan Assmann	  This option enables a workaround that fixes a source of
108341b9eb26SStefan Assmann	  spurious interrupts. This is recommended when threaded
108441b9eb26SStefan Assmann	  interrupt handling is used on systems where the generation of
108541b9eb26SStefan Assmann	  superfluous "boot interrupts" cannot be disabled.
108641b9eb26SStefan Assmann
108741b9eb26SStefan Assmann	  Some chipsets generate a legacy INTx "boot IRQ" when the IRQ
108841b9eb26SStefan Assmann	  entry in the chipset's IO-APIC is masked (as, e.g. the RT
108941b9eb26SStefan Assmann	  kernel does during interrupt handling). On chipsets where this
109041b9eb26SStefan Assmann	  boot IRQ generation cannot be disabled, this workaround keeps
109141b9eb26SStefan Assmann	  the original IRQ line masked so that only the equivalent "boot
109241b9eb26SStefan Assmann	  IRQ" is delivered to the CPUs. The workaround also tells the
109341b9eb26SStefan Assmann	  kernel to set up the IRQ handler on the boot IRQ line. In this
109441b9eb26SStefan Assmann	  way only one interrupt is delivered to the kernel. Otherwise
109541b9eb26SStefan Assmann	  the spurious second interrupt may cause the kernel to bring
109641b9eb26SStefan Assmann	  down (vital) interrupt lines.
109741b9eb26SStefan Assmann
109841b9eb26SStefan Assmann	  Only affects "broken" chipsets. Interrupt sharing may be
109941b9eb26SStefan Assmann	  increased on these systems.
110041b9eb26SStefan Assmann
1101506f1d07SSam Ravnborgconfig X86_MCE
1102bab9bc65SAndi Kleen	bool "Machine Check / overheating reporting"
1103648ed940SChen, Gong	select GENERIC_ALLOCATOR
1104e57dbaf7SBorislav Petkov	default y
1105a7f7f624SMasahiro Yamada	help
1106bab9bc65SAndi Kleen	  Machine Check support allows the processor to notify the
1107bab9bc65SAndi Kleen	  kernel if it detects a problem (e.g. overheating, data corruption).
1108506f1d07SSam Ravnborg	  The action the kernel takes depends on the severity of the problem,
1109bab9bc65SAndi Kleen	  ranging from warning messages to halting the machine.
11104efc0670SAndi Kleen
11115de97c9fSTony Luckconfig X86_MCELOG_LEGACY
11125de97c9fSTony Luck	bool "Support for deprecated /dev/mcelog character device"
11135de97c9fSTony Luck	depends on X86_MCE
1114a7f7f624SMasahiro Yamada	help
11155de97c9fSTony Luck	  Enable support for /dev/mcelog which is needed by the old mcelog
11165de97c9fSTony Luck	  userspace logging daemon. Consider switching to the new generation
11175de97c9fSTony Luck	  rasdaemon solution.
11185de97c9fSTony Luck
1119506f1d07SSam Ravnborgconfig X86_MCE_INTEL
11203c2362e6SHarvey Harrison	def_bool y
11213c2362e6SHarvey Harrison	prompt "Intel MCE features"
1122c1ebf835SAndi Kleen	depends on X86_MCE && X86_LOCAL_APIC
1123a7f7f624SMasahiro Yamada	help
1124506f1d07SSam Ravnborg	   Additional support for intel specific MCE features such as
1125506f1d07SSam Ravnborg	   the thermal monitor.
1126506f1d07SSam Ravnborg
1127506f1d07SSam Ravnborgconfig X86_MCE_AMD
11283c2362e6SHarvey Harrison	def_bool y
11293c2362e6SHarvey Harrison	prompt "AMD MCE features"
1130f5382de9SYazen Ghannam	depends on X86_MCE && X86_LOCAL_APIC && AMD_NB
1131a7f7f624SMasahiro Yamada	help
1132506f1d07SSam Ravnborg	   Additional support for AMD specific MCE features such as
1133506f1d07SSam Ravnborg	   the DRAM Error Threshold.
1134506f1d07SSam Ravnborg
11354efc0670SAndi Kleenconfig X86_ANCIENT_MCE
11366fc108a0SJan Beulich	bool "Support for old Pentium 5 / WinChip machine checks"
1137c31d9633SAndi Kleen	depends on X86_32 && X86_MCE
1138a7f7f624SMasahiro Yamada	help
11394efc0670SAndi Kleen	  Include support for machine check handling on old Pentium 5 or WinChip
11405065a706SMasanari Iida	  systems. These typically need to be enabled explicitly on the command
11414efc0670SAndi Kleen	  line.
11424efc0670SAndi Kleen
1143b2762686SAndi Kleenconfig X86_MCE_THRESHOLD
1144b2762686SAndi Kleen	depends on X86_MCE_AMD || X86_MCE_INTEL
11456fc108a0SJan Beulich	def_bool y
1146b2762686SAndi Kleen
1147ea149b36SAndi Kleenconfig X86_MCE_INJECT
1148bc8e80d5SBorislav Petkov	depends on X86_MCE && X86_LOCAL_APIC && DEBUG_FS
1149ea149b36SAndi Kleen	tristate "Machine check injector support"
1150a7f7f624SMasahiro Yamada	help
1151ea149b36SAndi Kleen	  Provide support for injecting machine checks for testing purposes.
1152ea149b36SAndi Kleen	  If you don't know what a machine check is and you don't do kernel
1153ea149b36SAndi Kleen	  QA it is safe to say n.
1154ea149b36SAndi Kleen
11554efc0670SAndi Kleenconfig X86_THERMAL_VECTOR
11564efc0670SAndi Kleen	def_bool y
11575bb38adcSAndi Kleen	depends on X86_MCE_INTEL
11584efc0670SAndi Kleen
115907dc900eSPeter Zijlstrasource "arch/x86/events/Kconfig"
1160e633c65aSKan Liang
11615aef51c3SAndy Lutomirskiconfig X86_LEGACY_VM86
11621e642812SIngo Molnar	bool "Legacy VM86 support"
1163506f1d07SSam Ravnborg	depends on X86_32
1164a7f7f624SMasahiro Yamada	help
11655aef51c3SAndy Lutomirski	  This option allows user programs to put the CPU into V8086
11665aef51c3SAndy Lutomirski	  mode, which is an 80286-era approximation of 16-bit real mode.
11675aef51c3SAndy Lutomirski
11685aef51c3SAndy Lutomirski	  Some very old versions of X and/or vbetool require this option
11695aef51c3SAndy Lutomirski	  for user mode setting.  Similarly, DOSEMU will use it if
11705aef51c3SAndy Lutomirski	  available to accelerate real mode DOS programs.  However, any
11715aef51c3SAndy Lutomirski	  recent version of DOSEMU, X, or vbetool should be fully
11725aef51c3SAndy Lutomirski	  functional even without kernel VM86 support, as they will all
11731e642812SIngo Molnar	  fall back to software emulation. Nevertheless, if you are using
11741e642812SIngo Molnar	  a 16-bit DOS program where 16-bit performance matters, vm86
11751e642812SIngo Molnar	  mode might be faster than emulation and you might want to
11761e642812SIngo Molnar	  enable this option.
11775aef51c3SAndy Lutomirski
11781e642812SIngo Molnar	  Note that any app that works on a 64-bit kernel is unlikely to
11791e642812SIngo Molnar	  need this option, as 64-bit kernels don't, and can't, support
11801e642812SIngo Molnar	  V8086 mode. This option is also unrelated to 16-bit protected
11811e642812SIngo Molnar	  mode and is not needed to run most 16-bit programs under Wine.
11825aef51c3SAndy Lutomirski
11831e642812SIngo Molnar	  Enabling this option increases the complexity of the kernel
11841e642812SIngo Molnar	  and slows down exception handling a tiny bit.
11855aef51c3SAndy Lutomirski
11861e642812SIngo Molnar	  If unsure, say N here.
11875aef51c3SAndy Lutomirski
11885aef51c3SAndy Lutomirskiconfig VM86
11895aef51c3SAndy Lutomirski	bool
11905aef51c3SAndy Lutomirski	default X86_LEGACY_VM86
119134273f41SH. Peter Anvin
119234273f41SH. Peter Anvinconfig X86_16BIT
119334273f41SH. Peter Anvin	bool "Enable support for 16-bit segments" if EXPERT
119434273f41SH. Peter Anvin	default y
1195a5b9e5a2SAndy Lutomirski	depends on MODIFY_LDT_SYSCALL
1196a7f7f624SMasahiro Yamada	help
119734273f41SH. Peter Anvin	  This option is required by programs like Wine to run 16-bit
119834273f41SH. Peter Anvin	  protected mode legacy code on x86 processors.  Disabling
119934273f41SH. Peter Anvin	  this option saves about 300 bytes on i386, or around 6K text
120034273f41SH. Peter Anvin	  plus 16K runtime memory on x86-64,
120134273f41SH. Peter Anvin
120234273f41SH. Peter Anvinconfig X86_ESPFIX32
120334273f41SH. Peter Anvin	def_bool y
120434273f41SH. Peter Anvin	depends on X86_16BIT && X86_32
1205506f1d07SSam Ravnborg
1206197725deSH. Peter Anvinconfig X86_ESPFIX64
1207197725deSH. Peter Anvin	def_bool y
120834273f41SH. Peter Anvin	depends on X86_16BIT && X86_64
1209506f1d07SSam Ravnborg
12101ad83c85SAndy Lutomirskiconfig X86_VSYSCALL_EMULATION
12111ad83c85SAndy Lutomirski	bool "Enable vsyscall emulation" if EXPERT
12121ad83c85SAndy Lutomirski	default y
12131ad83c85SAndy Lutomirski	depends on X86_64
1214a7f7f624SMasahiro Yamada	help
12151ad83c85SAndy Lutomirski	 This enables emulation of the legacy vsyscall page.  Disabling
12161ad83c85SAndy Lutomirski	 it is roughly equivalent to booting with vsyscall=none, except
12171ad83c85SAndy Lutomirski	 that it will also disable the helpful warning if a program
12181ad83c85SAndy Lutomirski	 tries to use a vsyscall.  With this option set to N, offending
12191ad83c85SAndy Lutomirski	 programs will just segfault, citing addresses of the form
12201ad83c85SAndy Lutomirski	 0xffffffffff600?00.
12211ad83c85SAndy Lutomirski
12221ad83c85SAndy Lutomirski	 This option is required by many programs built before 2013, and
12231ad83c85SAndy Lutomirski	 care should be used even with newer programs if set to N.
12241ad83c85SAndy Lutomirski
12251ad83c85SAndy Lutomirski	 Disabling this option saves about 7K of kernel size and
12261ad83c85SAndy Lutomirski	 possibly 4K of additional runtime pagetable memory.
12271ad83c85SAndy Lutomirski
1228111e7b15SThomas Gleixnerconfig X86_IOPL_IOPERM
1229111e7b15SThomas Gleixner	bool "IOPERM and IOPL Emulation"
1230a24ca997SThomas Gleixner	default y
1231a7f7f624SMasahiro Yamada	help
1232111e7b15SThomas Gleixner	  This enables the ioperm() and iopl() syscalls which are necessary
1233111e7b15SThomas Gleixner	  for legacy applications.
1234111e7b15SThomas Gleixner
1235c8137aceSThomas Gleixner	  Legacy IOPL support is an overbroad mechanism which allows user
1236c8137aceSThomas Gleixner	  space aside of accessing all 65536 I/O ports also to disable
1237c8137aceSThomas Gleixner	  interrupts. To gain this access the caller needs CAP_SYS_RAWIO
1238c8137aceSThomas Gleixner	  capabilities and permission from potentially active security
1239c8137aceSThomas Gleixner	  modules.
1240c8137aceSThomas Gleixner
1241c8137aceSThomas Gleixner	  The emulation restricts the functionality of the syscall to
1242c8137aceSThomas Gleixner	  only allowing the full range I/O port access, but prevents the
1243a24ca997SThomas Gleixner	  ability to disable interrupts from user space which would be
1244a24ca997SThomas Gleixner	  granted if the hardware IOPL mechanism would be used.
1245c8137aceSThomas Gleixner
1246506f1d07SSam Ravnborgconfig TOSHIBA
1247506f1d07SSam Ravnborg	tristate "Toshiba Laptop support"
1248506f1d07SSam Ravnborg	depends on X86_32
1249a7f7f624SMasahiro Yamada	help
1250506f1d07SSam Ravnborg	  This adds a driver to safely access the System Management Mode of
1251506f1d07SSam Ravnborg	  the CPU on Toshiba portables with a genuine Toshiba BIOS. It does
1252506f1d07SSam Ravnborg	  not work on models with a Phoenix BIOS. The System Management Mode
1253506f1d07SSam Ravnborg	  is used to set the BIOS and power saving options on Toshiba portables.
1254506f1d07SSam Ravnborg
1255506f1d07SSam Ravnborg	  For information on utilities to make use of this driver see the
1256506f1d07SSam Ravnborg	  Toshiba Linux utilities web site at:
1257506f1d07SSam Ravnborg	  <http://www.buzzard.org.uk/toshiba/>.
1258506f1d07SSam Ravnborg
1259506f1d07SSam Ravnborg	  Say Y if you intend to run this kernel on a Toshiba portable.
1260506f1d07SSam Ravnborg	  Say N otherwise.
1261506f1d07SSam Ravnborg
1262506f1d07SSam Ravnborgconfig I8K
1263039ae585SPali Rohár	tristate "Dell i8k legacy laptop support"
1264949a9d70SJean Delvare	select HWMON
1265039ae585SPali Rohár	select SENSORS_DELL_SMM
1266a7f7f624SMasahiro Yamada	help
1267039ae585SPali Rohár	  This option enables legacy /proc/i8k userspace interface in hwmon
1268039ae585SPali Rohár	  dell-smm-hwmon driver. Character file /proc/i8k reports bios version,
1269039ae585SPali Rohár	  temperature and allows controlling fan speeds of Dell laptops via
1270039ae585SPali Rohár	  System Management Mode. For old Dell laptops (like Dell Inspiron 8000)
1271039ae585SPali Rohár	  it reports also power and hotkey status. For fan speed control is
1272039ae585SPali Rohár	  needed userspace package i8kutils.
1273506f1d07SSam Ravnborg
1274039ae585SPali Rohár	  Say Y if you intend to run this kernel on old Dell laptops or want to
1275039ae585SPali Rohár	  use userspace package i8kutils.
1276506f1d07SSam Ravnborg	  Say N otherwise.
1277506f1d07SSam Ravnborg
1278506f1d07SSam Ravnborgconfig X86_REBOOTFIXUPS
12799ba16087SJan Beulich	bool "Enable X86 board specific fixups for reboot"
12809ba16087SJan Beulich	depends on X86_32
1281a7f7f624SMasahiro Yamada	help
1282506f1d07SSam Ravnborg	  This enables chipset and/or board specific fixups to be done
1283506f1d07SSam Ravnborg	  in order to get reboot to work correctly. This is only needed on
1284506f1d07SSam Ravnborg	  some combinations of hardware and BIOS. The symptom, for which
1285506f1d07SSam Ravnborg	  this config is intended, is when reboot ends with a stalled/hung
1286506f1d07SSam Ravnborg	  system.
1287506f1d07SSam Ravnborg
1288506f1d07SSam Ravnborg	  Currently, the only fixup is for the Geode machines using
12895e3a77e9SFlorian Fainelli	  CS5530A and CS5536 chipsets and the RDC R-321x SoC.
1290506f1d07SSam Ravnborg
1291506f1d07SSam Ravnborg	  Say Y if you want to enable the fixup. Currently, it's safe to
1292506f1d07SSam Ravnborg	  enable this option even if you don't need it.
1293506f1d07SSam Ravnborg	  Say N otherwise.
1294506f1d07SSam Ravnborg
1295506f1d07SSam Ravnborgconfig MICROCODE
12969a2bc335SBorislav Petkov	bool "CPU microcode loading support"
12979a2bc335SBorislav Petkov	default y
129880030e3dSBorislav Petkov	depends on CPU_SUP_AMD || CPU_SUP_INTEL
1299a7f7f624SMasahiro Yamada	help
1300506f1d07SSam Ravnborg	  If you say Y here, you will be able to update the microcode on
13015f9c01aaSBorislav Petkov	  Intel and AMD processors. The Intel support is for the IA32 family,
13025f9c01aaSBorislav Petkov	  e.g. Pentium Pro, Pentium II, Pentium III, Pentium 4, Xeon etc. The
13035f9c01aaSBorislav Petkov	  AMD support is for families 0x10 and later. You will obviously need
13045f9c01aaSBorislav Petkov	  the actual microcode binary data itself which is not shipped with
13055f9c01aaSBorislav Petkov	  the Linux kernel.
1306506f1d07SSam Ravnborg
13075f9c01aaSBorislav Petkov	  The preferred method to load microcode from a detached initrd is described
1308cb1aaebeSMauro Carvalho Chehab	  in Documentation/x86/microcode.rst. For that you need to enable
13095f9c01aaSBorislav Petkov	  CONFIG_BLK_DEV_INITRD in order for the loader to be able to scan the
13105f9c01aaSBorislav Petkov	  initrd for microcode blobs.
1311506f1d07SSam Ravnborg
1312c508c46eSBenjamin Gilbert	  In addition, you can build the microcode into the kernel. For that you
1313c508c46eSBenjamin Gilbert	  need to add the vendor-supplied microcode to the CONFIG_EXTRA_FIRMWARE
1314c508c46eSBenjamin Gilbert	  config option.
1315506f1d07SSam Ravnborg
13168d86f390SPeter Orubaconfig MICROCODE_INTEL
1317e43f6e67SBorislav Petkov	bool "Intel microcode loading support"
13188d86f390SPeter Oruba	depends on MICROCODE
13198d86f390SPeter Oruba	default MICROCODE
1320a7f7f624SMasahiro Yamada	help
13218d86f390SPeter Oruba	  This options enables microcode patch loading support for Intel
13228d86f390SPeter Oruba	  processors.
13238d86f390SPeter Oruba
1324b8989db9SAlan	  For the current Intel microcode data package go to
1325b8989db9SAlan	  <https://downloadcenter.intel.com> and search for
1326b8989db9SAlan	  'Linux Processor Microcode Data File'.
13278d86f390SPeter Oruba
132880cc9f10SPeter Orubaconfig MICROCODE_AMD
1329e43f6e67SBorislav Petkov	bool "AMD microcode loading support"
133080cc9f10SPeter Oruba	depends on MICROCODE
1331a7f7f624SMasahiro Yamada	help
133280cc9f10SPeter Oruba	  If you select this option, microcode patch loading support for AMD
133380cc9f10SPeter Oruba	  processors will be enabled.
133480cc9f10SPeter Oruba
1335506f1d07SSam Ravnborgconfig MICROCODE_OLD_INTERFACE
1336c02f48e0SBorislav Petkov	bool "Ancient loading interface (DEPRECATED)"
1337c02f48e0SBorislav Petkov	default n
1338506f1d07SSam Ravnborg	depends on MICROCODE
1339a7f7f624SMasahiro Yamada	help
1340c02f48e0SBorislav Petkov	  DO NOT USE THIS! This is the ancient /dev/cpu/microcode interface
1341c02f48e0SBorislav Petkov	  which was used by userspace tools like iucode_tool and microcode.ctl.
1342c02f48e0SBorislav Petkov	  It is inadequate because it runs too late to be able to properly
1343c02f48e0SBorislav Petkov	  load microcode on a machine and it needs special tools. Instead, you
1344c02f48e0SBorislav Petkov	  should've switched to the early loading method with the initrd or
1345cb1aaebeSMauro Carvalho Chehab	  builtin microcode by now: Documentation/x86/microcode.rst
1346506f1d07SSam Ravnborg
1347506f1d07SSam Ravnborgconfig X86_MSR
1348506f1d07SSam Ravnborg	tristate "/dev/cpu/*/msr - Model-specific register support"
1349a7f7f624SMasahiro Yamada	help
1350506f1d07SSam Ravnborg	  This device gives privileged processes access to the x86
1351506f1d07SSam Ravnborg	  Model-Specific Registers (MSRs).  It is a character device with
1352506f1d07SSam Ravnborg	  major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr.
1353506f1d07SSam Ravnborg	  MSR accesses are directed to a specific CPU on multi-processor
1354506f1d07SSam Ravnborg	  systems.
1355506f1d07SSam Ravnborg
1356506f1d07SSam Ravnborgconfig X86_CPUID
1357506f1d07SSam Ravnborg	tristate "/dev/cpu/*/cpuid - CPU information support"
1358a7f7f624SMasahiro Yamada	help
1359506f1d07SSam Ravnborg	  This device gives processes access to the x86 CPUID instruction to
1360506f1d07SSam Ravnborg	  be executed on a specific processor.  It is a character device
1361506f1d07SSam Ravnborg	  with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to
1362506f1d07SSam Ravnborg	  /dev/cpu/31/cpuid.
1363506f1d07SSam Ravnborg
1364506f1d07SSam Ravnborgchoice
1365506f1d07SSam Ravnborg	prompt "High Memory Support"
13666fc108a0SJan Beulich	default HIGHMEM4G
1367506f1d07SSam Ravnborg	depends on X86_32
1368506f1d07SSam Ravnborg
1369506f1d07SSam Ravnborgconfig NOHIGHMEM
1370506f1d07SSam Ravnborg	bool "off"
1371a7f7f624SMasahiro Yamada	help
1372506f1d07SSam Ravnborg	  Linux can use up to 64 Gigabytes of physical memory on x86 systems.
1373506f1d07SSam Ravnborg	  However, the address space of 32-bit x86 processors is only 4
1374506f1d07SSam Ravnborg	  Gigabytes large. That means that, if you have a large amount of
1375506f1d07SSam Ravnborg	  physical memory, not all of it can be "permanently mapped" by the
1376506f1d07SSam Ravnborg	  kernel. The physical memory that's not permanently mapped is called
1377506f1d07SSam Ravnborg	  "high memory".
1378506f1d07SSam Ravnborg
1379506f1d07SSam Ravnborg	  If you are compiling a kernel which will never run on a machine with
1380506f1d07SSam Ravnborg	  more than 1 Gigabyte total physical RAM, answer "off" here (default
1381506f1d07SSam Ravnborg	  choice and suitable for most users). This will result in a "3GB/1GB"
1382506f1d07SSam Ravnborg	  split: 3GB are mapped so that each process sees a 3GB virtual memory
1383506f1d07SSam Ravnborg	  space and the remaining part of the 4GB virtual memory space is used
1384506f1d07SSam Ravnborg	  by the kernel to permanently map as much physical memory as
1385506f1d07SSam Ravnborg	  possible.
1386506f1d07SSam Ravnborg
1387506f1d07SSam Ravnborg	  If the machine has between 1 and 4 Gigabytes physical RAM, then
1388506f1d07SSam Ravnborg	  answer "4GB" here.
1389506f1d07SSam Ravnborg
1390506f1d07SSam Ravnborg	  If more than 4 Gigabytes is used then answer "64GB" here. This
1391506f1d07SSam Ravnborg	  selection turns Intel PAE (Physical Address Extension) mode on.
1392506f1d07SSam Ravnborg	  PAE implements 3-level paging on IA32 processors. PAE is fully
1393506f1d07SSam Ravnborg	  supported by Linux, PAE mode is implemented on all recent Intel
1394506f1d07SSam Ravnborg	  processors (Pentium Pro and better). NOTE: If you say "64GB" here,
1395506f1d07SSam Ravnborg	  then the kernel will not boot on CPUs that don't support PAE!
1396506f1d07SSam Ravnborg
1397506f1d07SSam Ravnborg	  The actual amount of total physical memory will either be
1398506f1d07SSam Ravnborg	  auto detected or can be forced by using a kernel command line option
1399506f1d07SSam Ravnborg	  such as "mem=256M". (Try "man bootparam" or see the documentation of
1400506f1d07SSam Ravnborg	  your boot loader (lilo or loadlin) about how to pass options to the
1401506f1d07SSam Ravnborg	  kernel at boot time.)
1402506f1d07SSam Ravnborg
1403506f1d07SSam Ravnborg	  If unsure, say "off".
1404506f1d07SSam Ravnborg
1405506f1d07SSam Ravnborgconfig HIGHMEM4G
1406506f1d07SSam Ravnborg	bool "4GB"
1407a7f7f624SMasahiro Yamada	help
1408506f1d07SSam Ravnborg	  Select this if you have a 32-bit processor and between 1 and 4
1409506f1d07SSam Ravnborg	  gigabytes of physical RAM.
1410506f1d07SSam Ravnborg
1411506f1d07SSam Ravnborgconfig HIGHMEM64G
1412506f1d07SSam Ravnborg	bool "64GB"
141369b8d3fcSMatthew Whitehead	depends on !M486 && !M586 && !M586TSC && !M586MMX && !MGEODE_LX && !MGEODEGX1 && !MCYRIXIII && !MELAN && !MWINCHIPC6 && !WINCHIP3D && !MK6
1414506f1d07SSam Ravnborg	select X86_PAE
1415a7f7f624SMasahiro Yamada	help
1416506f1d07SSam Ravnborg	  Select this if you have a 32-bit processor and more than 4
1417506f1d07SSam Ravnborg	  gigabytes of physical RAM.
1418506f1d07SSam Ravnborg
1419506f1d07SSam Ravnborgendchoice
1420506f1d07SSam Ravnborg
1421506f1d07SSam Ravnborgchoice
14226a108a14SDavid Rientjes	prompt "Memory split" if EXPERT
1423506f1d07SSam Ravnborg	default VMSPLIT_3G
1424506f1d07SSam Ravnborg	depends on X86_32
1425a7f7f624SMasahiro Yamada	help
1426506f1d07SSam Ravnborg	  Select the desired split between kernel and user memory.
1427506f1d07SSam Ravnborg
1428506f1d07SSam Ravnborg	  If the address range available to the kernel is less than the
1429506f1d07SSam Ravnborg	  physical memory installed, the remaining memory will be available
1430506f1d07SSam Ravnborg	  as "high memory". Accessing high memory is a little more costly
1431506f1d07SSam Ravnborg	  than low memory, as it needs to be mapped into the kernel first.
1432506f1d07SSam Ravnborg	  Note that increasing the kernel address space limits the range
1433506f1d07SSam Ravnborg	  available to user programs, making the address space there
1434506f1d07SSam Ravnborg	  tighter.  Selecting anything other than the default 3G/1G split
1435506f1d07SSam Ravnborg	  will also likely make your kernel incompatible with binary-only
1436506f1d07SSam Ravnborg	  kernel modules.
1437506f1d07SSam Ravnborg
1438506f1d07SSam Ravnborg	  If you are not absolutely sure what you are doing, leave this
1439506f1d07SSam Ravnborg	  option alone!
1440506f1d07SSam Ravnborg
1441506f1d07SSam Ravnborg	config VMSPLIT_3G
1442506f1d07SSam Ravnborg		bool "3G/1G user/kernel split"
1443506f1d07SSam Ravnborg	config VMSPLIT_3G_OPT
1444506f1d07SSam Ravnborg		depends on !X86_PAE
1445506f1d07SSam Ravnborg		bool "3G/1G user/kernel split (for full 1G low memory)"
1446506f1d07SSam Ravnborg	config VMSPLIT_2G
1447506f1d07SSam Ravnborg		bool "2G/2G user/kernel split"
1448506f1d07SSam Ravnborg	config VMSPLIT_2G_OPT
1449506f1d07SSam Ravnborg		depends on !X86_PAE
1450506f1d07SSam Ravnborg		bool "2G/2G user/kernel split (for full 2G low memory)"
1451506f1d07SSam Ravnborg	config VMSPLIT_1G
1452506f1d07SSam Ravnborg		bool "1G/3G user/kernel split"
1453506f1d07SSam Ravnborgendchoice
1454506f1d07SSam Ravnborg
1455506f1d07SSam Ravnborgconfig PAGE_OFFSET
1456506f1d07SSam Ravnborg	hex
1457506f1d07SSam Ravnborg	default 0xB0000000 if VMSPLIT_3G_OPT
1458506f1d07SSam Ravnborg	default 0x80000000 if VMSPLIT_2G
1459506f1d07SSam Ravnborg	default 0x78000000 if VMSPLIT_2G_OPT
1460506f1d07SSam Ravnborg	default 0x40000000 if VMSPLIT_1G
1461506f1d07SSam Ravnborg	default 0xC0000000
1462506f1d07SSam Ravnborg	depends on X86_32
1463506f1d07SSam Ravnborg
1464506f1d07SSam Ravnborgconfig HIGHMEM
14653c2362e6SHarvey Harrison	def_bool y
1466506f1d07SSam Ravnborg	depends on X86_32 && (HIGHMEM64G || HIGHMEM4G)
1467506f1d07SSam Ravnborg
1468506f1d07SSam Ravnborgconfig X86_PAE
14699ba16087SJan Beulich	bool "PAE (Physical Address Extension) Support"
1470506f1d07SSam Ravnborg	depends on X86_32 && !HIGHMEM4G
1471d4a451d5SChristoph Hellwig	select PHYS_ADDR_T_64BIT
14729d99c712SChristian Melki	select SWIOTLB
1473a7f7f624SMasahiro Yamada	help
1474506f1d07SSam Ravnborg	  PAE is required for NX support, and furthermore enables
1475506f1d07SSam Ravnborg	  larger swapspace support for non-overcommit purposes. It
1476506f1d07SSam Ravnborg	  has the cost of more pagetable lookup overhead, and also
1477506f1d07SSam Ravnborg	  consumes more pagetable space per process.
1478506f1d07SSam Ravnborg
147977ef56e4SKirill A. Shutemovconfig X86_5LEVEL
148077ef56e4SKirill A. Shutemov	bool "Enable 5-level page tables support"
148118ec1eafSKirill A. Shutemov	default y
1482eedb92abSKirill A. Shutemov	select DYNAMIC_MEMORY_LAYOUT
1483162434e7SKirill A. Shutemov	select SPARSEMEM_VMEMMAP
148477ef56e4SKirill A. Shutemov	depends on X86_64
1485a7f7f624SMasahiro Yamada	help
148677ef56e4SKirill A. Shutemov	  5-level paging enables access to larger address space:
148777ef56e4SKirill A. Shutemov	  upto 128 PiB of virtual address space and 4 PiB of
148877ef56e4SKirill A. Shutemov	  physical address space.
148977ef56e4SKirill A. Shutemov
149077ef56e4SKirill A. Shutemov	  It will be supported by future Intel CPUs.
149177ef56e4SKirill A. Shutemov
14926657fca0SKirill A. Shutemov	  A kernel with the option enabled can be booted on machines that
14936657fca0SKirill A. Shutemov	  support 4- or 5-level paging.
149477ef56e4SKirill A. Shutemov
1495cb1aaebeSMauro Carvalho Chehab	  See Documentation/x86/x86_64/5level-paging.rst for more
149677ef56e4SKirill A. Shutemov	  information.
149777ef56e4SKirill A. Shutemov
149877ef56e4SKirill A. Shutemov	  Say N if unsure.
149977ef56e4SKirill A. Shutemov
150010971ab2SIngo Molnarconfig X86_DIRECT_GBPAGES
1501e5008abeSLuis R. Rodriguez	def_bool y
15022e1da13fSVlastimil Babka	depends on X86_64
1503a7f7f624SMasahiro Yamada	help
150410971ab2SIngo Molnar	  Certain kernel features effectively disable kernel
150510971ab2SIngo Molnar	  linear 1 GB mappings (even if the CPU otherwise
150610971ab2SIngo Molnar	  supports them), so don't confuse the user by printing
150710971ab2SIngo Molnar	  that we have them enabled.
15089e899816SNick Piggin
15095c280cf6SThomas Gleixnerconfig X86_CPA_STATISTICS
15105c280cf6SThomas Gleixner	bool "Enable statistic for Change Page Attribute"
15115c280cf6SThomas Gleixner	depends on DEBUG_FS
1512a7f7f624SMasahiro Yamada	help
1513b75baaf3SIngo Molnar	  Expose statistics about the Change Page Attribute mechanism, which
1514a943245aSColin Ian King	  helps to determine the effectiveness of preserving large and huge
15155c280cf6SThomas Gleixner	  page mappings when mapping protections are changed.
15165c280cf6SThomas Gleixner
15177744ccdbSTom Lendackyconfig AMD_MEM_ENCRYPT
15187744ccdbSTom Lendacky	bool "AMD Secure Memory Encryption (SME) support"
15197744ccdbSTom Lendacky	depends on X86_64 && CPU_SUP_AMD
152082fef0adSDavid Rientjes	select DMA_COHERENT_POOL
152194d49eb3SKirill A. Shutemov	select DYNAMIC_PHYSICAL_MASK
1522ce9084baSArd Biesheuvel	select ARCH_USE_MEMREMAP_PROT
15239087c375STom Lendacky	select ARCH_HAS_FORCE_DMA_UNENCRYPTED
1524a7f7f624SMasahiro Yamada	help
15257744ccdbSTom Lendacky	  Say yes to enable support for the encryption of system memory.
15267744ccdbSTom Lendacky	  This requires an AMD processor that supports Secure Memory
15277744ccdbSTom Lendacky	  Encryption (SME).
15287744ccdbSTom Lendacky
15297744ccdbSTom Lendackyconfig AMD_MEM_ENCRYPT_ACTIVE_BY_DEFAULT
15307744ccdbSTom Lendacky	bool "Activate AMD Secure Memory Encryption (SME) by default"
15317744ccdbSTom Lendacky	default y
15327744ccdbSTom Lendacky	depends on AMD_MEM_ENCRYPT
1533a7f7f624SMasahiro Yamada	help
15347744ccdbSTom Lendacky	  Say yes to have system memory encrypted by default if running on
15357744ccdbSTom Lendacky	  an AMD processor that supports Secure Memory Encryption (SME).
15367744ccdbSTom Lendacky
15377744ccdbSTom Lendacky	  If set to Y, then the encryption of system memory can be
15387744ccdbSTom Lendacky	  deactivated with the mem_encrypt=off command line option.
15397744ccdbSTom Lendacky
15407744ccdbSTom Lendacky	  If set to N, then the encryption of system memory can be
15417744ccdbSTom Lendacky	  activated with the mem_encrypt=on command line option.
15427744ccdbSTom Lendacky
1543506f1d07SSam Ravnborg# Common NUMA Features
1544506f1d07SSam Ravnborgconfig NUMA
1545e133f6eaSRandy Dunlap	bool "NUMA Memory Allocation and Scheduler Support"
1546506f1d07SSam Ravnborg	depends on SMP
1547b5660ba7SH. Peter Anvin	depends on X86_64 || (X86_32 && HIGHMEM64G && X86_BIGSMP)
1548b5660ba7SH. Peter Anvin	default y if X86_BIGSMP
1549a7f7f624SMasahiro Yamada	help
1550e133f6eaSRandy Dunlap	  Enable NUMA (Non-Uniform Memory Access) support.
1551fd51b2d7SKOSAKI Motohiro
1552506f1d07SSam Ravnborg	  The kernel will try to allocate memory used by a CPU on the
1553506f1d07SSam Ravnborg	  local memory controller of the CPU and add some more
1554506f1d07SSam Ravnborg	  NUMA awareness to the kernel.
1555506f1d07SSam Ravnborg
1556c280ea5eSIngo Molnar	  For 64-bit this is recommended if the system is Intel Core i7
1557fd51b2d7SKOSAKI Motohiro	  (or later), AMD Opteron, or EM64T NUMA.
1558fd51b2d7SKOSAKI Motohiro
1559b5660ba7SH. Peter Anvin	  For 32-bit this is only needed if you boot a 32-bit
15607cf6c945SDavid Rientjes	  kernel on a 64-bit NUMA platform.
1561fd51b2d7SKOSAKI Motohiro
1562fd51b2d7SKOSAKI Motohiro	  Otherwise, you should say N.
1563506f1d07SSam Ravnborg
1564eec1d4faSHans Rosenfeldconfig AMD_NUMA
15653c2362e6SHarvey Harrison	def_bool y
15663c2362e6SHarvey Harrison	prompt "Old style AMD Opteron NUMA detection"
15675da0ef9aSTejun Heo	depends on X86_64 && NUMA && PCI
1568a7f7f624SMasahiro Yamada	help
1569eec1d4faSHans Rosenfeld	  Enable AMD NUMA node topology detection.  You should say Y here if
1570eec1d4faSHans Rosenfeld	  you have a multi processor AMD system. This uses an old method to
1571eec1d4faSHans Rosenfeld	  read the NUMA configuration directly from the builtin Northbridge
1572eec1d4faSHans Rosenfeld	  of Opteron. It is recommended to use X86_64_ACPI_NUMA instead,
1573eec1d4faSHans Rosenfeld	  which also takes priority if both are compiled in.
1574506f1d07SSam Ravnborg
1575506f1d07SSam Ravnborgconfig X86_64_ACPI_NUMA
15763c2362e6SHarvey Harrison	def_bool y
15773c2362e6SHarvey Harrison	prompt "ACPI NUMA detection"
1578506f1d07SSam Ravnborg	depends on X86_64 && NUMA && ACPI && PCI
1579506f1d07SSam Ravnborg	select ACPI_NUMA
1580a7f7f624SMasahiro Yamada	help
1581506f1d07SSam Ravnborg	  Enable ACPI SRAT based node topology detection.
1582506f1d07SSam Ravnborg
1583506f1d07SSam Ravnborgconfig NUMA_EMU
1584506f1d07SSam Ravnborg	bool "NUMA emulation"
15851b7e03efSTejun Heo	depends on NUMA
1586a7f7f624SMasahiro Yamada	help
1587506f1d07SSam Ravnborg	  Enable NUMA emulation. A flat machine will be split
1588506f1d07SSam Ravnborg	  into virtual nodes when booted with "numa=fake=N", where N is the
1589506f1d07SSam Ravnborg	  number of nodes. This is only useful for debugging.
1590506f1d07SSam Ravnborg
1591506f1d07SSam Ravnborgconfig NODES_SHIFT
1592d25e26b6SLinus Torvalds	int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP
159351591e31SDavid Rientjes	range 1 10
159451591e31SDavid Rientjes	default "10" if MAXSMP
1595506f1d07SSam Ravnborg	default "6" if X86_64
1596506f1d07SSam Ravnborg	default "3"
1597506f1d07SSam Ravnborg	depends on NEED_MULTIPLE_NODES
1598a7f7f624SMasahiro Yamada	help
15991184dc2fSMike Travis	  Specify the maximum number of NUMA Nodes available on the target
1600692105b8SMatt LaPlante	  system.  Increases memory reserved to accommodate various tables.
1601506f1d07SSam Ravnborg
1602506f1d07SSam Ravnborgconfig ARCH_FLATMEM_ENABLE
1603506f1d07SSam Ravnborg	def_bool y
16043b16651fSTejun Heo	depends on X86_32 && !NUMA
1605506f1d07SSam Ravnborg
1606506f1d07SSam Ravnborgconfig ARCH_SPARSEMEM_ENABLE
1607506f1d07SSam Ravnborg	def_bool y
16086ea30386SKees Cook	depends on X86_64 || NUMA || X86_32 || X86_32_NON_STANDARD
1609506f1d07SSam Ravnborg	select SPARSEMEM_STATIC if X86_32
1610506f1d07SSam Ravnborg	select SPARSEMEM_VMEMMAP_ENABLE if X86_64
1611506f1d07SSam Ravnborg
16123b16651fSTejun Heoconfig ARCH_SPARSEMEM_DEFAULT
16136ad57f7fSMike Rapoport	def_bool X86_64 || (NUMA && X86_32)
16143b16651fSTejun Heo
1615506f1d07SSam Ravnborgconfig ARCH_SELECT_MEMORY_MODEL
1616506f1d07SSam Ravnborg	def_bool y
1617b263295dSChristoph Lameter	depends on ARCH_SPARSEMEM_ENABLE
1618506f1d07SSam Ravnborg
1619506f1d07SSam Ravnborgconfig ARCH_MEMORY_PROBE
1620a0842b70SToshi Kani	bool "Enable sysfs memory/probe interface"
16213120e25eSJan Beulich	depends on X86_64 && MEMORY_HOTPLUG
1622a0842b70SToshi Kani	help
1623a0842b70SToshi Kani	  This option enables a sysfs memory/probe interface for testing.
1624cb1aaebeSMauro Carvalho Chehab	  See Documentation/admin-guide/mm/memory-hotplug.rst for more information.
1625a0842b70SToshi Kani	  If you are unsure how to answer this question, answer N.
1626506f1d07SSam Ravnborg
16273b16651fSTejun Heoconfig ARCH_PROC_KCORE_TEXT
16283b16651fSTejun Heo	def_bool y
16293b16651fSTejun Heo	depends on X86_64 && PROC_KCORE
16303b16651fSTejun Heo
1631a29815a3SAvi Kivityconfig ILLEGAL_POINTER_VALUE
1632a29815a3SAvi Kivity	hex
1633a29815a3SAvi Kivity	default 0 if X86_32
1634a29815a3SAvi Kivity	default 0xdead000000000000 if X86_64
1635a29815a3SAvi Kivity
16367a67832cSDan Williamsconfig X86_PMEM_LEGACY_DEVICE
16377a67832cSDan Williams	bool
16387a67832cSDan Williams
1639ec776ef6SChristoph Hellwigconfig X86_PMEM_LEGACY
16407a67832cSDan Williams	tristate "Support non-standard NVDIMMs and ADR protected memory"
16419f53f9faSDan Williams	depends on PHYS_ADDR_T_64BIT
16429f53f9faSDan Williams	depends on BLK_DEV
16437a67832cSDan Williams	select X86_PMEM_LEGACY_DEVICE
16447b27a862SDan Williams	select NUMA_KEEP_MEMINFO if NUMA
16459f53f9faSDan Williams	select LIBNVDIMM
1646ec776ef6SChristoph Hellwig	help
1647ec776ef6SChristoph Hellwig	  Treat memory marked using the non-standard e820 type of 12 as used
1648ec776ef6SChristoph Hellwig	  by the Intel Sandy Bridge-EP reference BIOS as protected memory.
1649ec776ef6SChristoph Hellwig	  The kernel will offer these regions to the 'pmem' driver so
1650ec776ef6SChristoph Hellwig	  they can be used for persistent storage.
1651ec776ef6SChristoph Hellwig
1652ec776ef6SChristoph Hellwig	  Say Y if unsure.
1653ec776ef6SChristoph Hellwig
1654506f1d07SSam Ravnborgconfig HIGHPTE
1655506f1d07SSam Ravnborg	bool "Allocate 3rd-level pagetables from highmem"
16566fc108a0SJan Beulich	depends on HIGHMEM
1657a7f7f624SMasahiro Yamada	help
1658506f1d07SSam Ravnborg	  The VM uses one page table entry for each page of physical memory.
1659506f1d07SSam Ravnborg	  For systems with a lot of RAM, this can be wasteful of precious
1660506f1d07SSam Ravnborg	  low memory.  Setting this option will put user-space page table
1661506f1d07SSam Ravnborg	  entries in high memory.
1662506f1d07SSam Ravnborg
16639f077871SJeremy Fitzhardingeconfig X86_CHECK_BIOS_CORRUPTION
16649f077871SJeremy Fitzhardinge	bool "Check for low memory corruption"
1665a7f7f624SMasahiro Yamada	help
16669f077871SJeremy Fitzhardinge	  Periodically check for memory corruption in low memory, which
16679f077871SJeremy Fitzhardinge	  is suspected to be caused by BIOS.  Even when enabled in the
16689f077871SJeremy Fitzhardinge	  configuration, it is disabled at runtime.  Enable it by
16699f077871SJeremy Fitzhardinge	  setting "memory_corruption_check=1" on the kernel command
16709f077871SJeremy Fitzhardinge	  line.  By default it scans the low 64k of memory every 60
16719f077871SJeremy Fitzhardinge	  seconds; see the memory_corruption_check_size and
16729f077871SJeremy Fitzhardinge	  memory_corruption_check_period parameters in
16738c27ceffSMauro Carvalho Chehab	  Documentation/admin-guide/kernel-parameters.rst to adjust this.
16749f077871SJeremy Fitzhardinge
16759f077871SJeremy Fitzhardinge	  When enabled with the default parameters, this option has
16769f077871SJeremy Fitzhardinge	  almost no overhead, as it reserves a relatively small amount
16779f077871SJeremy Fitzhardinge	  of memory and scans it infrequently.  It both detects corruption
16789f077871SJeremy Fitzhardinge	  and prevents it from affecting the running system.
16799f077871SJeremy Fitzhardinge
16809f077871SJeremy Fitzhardinge	  It is, however, intended as a diagnostic tool; if repeatable
16819f077871SJeremy Fitzhardinge	  BIOS-originated corruption always affects the same memory,
16829f077871SJeremy Fitzhardinge	  you can use memmap= to prevent the kernel from using that
16839f077871SJeremy Fitzhardinge	  memory.
16849f077871SJeremy Fitzhardinge
1685c885df50SJeremy Fitzhardingeconfig X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK
1686c885df50SJeremy Fitzhardinge	bool "Set the default setting of memory_corruption_check"
1687c885df50SJeremy Fitzhardinge	depends on X86_CHECK_BIOS_CORRUPTION
1688c885df50SJeremy Fitzhardinge	default y
1689a7f7f624SMasahiro Yamada	help
1690c885df50SJeremy Fitzhardinge	  Set whether the default state of memory_corruption_check is
1691c885df50SJeremy Fitzhardinge	  on or off.
1692c885df50SJeremy Fitzhardinge
16939ea77bdbSH. Peter Anvinconfig X86_RESERVE_LOW
1694d0cd7425SH. Peter Anvin	int "Amount of low memory, in kilobytes, to reserve for the BIOS"
1695d0cd7425SH. Peter Anvin	default 64
1696d0cd7425SH. Peter Anvin	range 4 640
1697a7f7f624SMasahiro Yamada	help
1698d0cd7425SH. Peter Anvin	  Specify the amount of low memory to reserve for the BIOS.
1699fc381519SIngo Molnar
1700d0cd7425SH. Peter Anvin	  The first page contains BIOS data structures that the kernel
1701d0cd7425SH. Peter Anvin	  must not use, so that page must always be reserved.
1702fc381519SIngo Molnar
1703d0cd7425SH. Peter Anvin	  By default we reserve the first 64K of physical RAM, as a
1704d0cd7425SH. Peter Anvin	  number of BIOSes are known to corrupt that memory range
1705d0cd7425SH. Peter Anvin	  during events such as suspend/resume or monitor cable
1706d0cd7425SH. Peter Anvin	  insertion, so it must not be used by the kernel.
1707fc381519SIngo Molnar
1708d0cd7425SH. Peter Anvin	  You can set this to 4 if you are absolutely sure that you
1709d0cd7425SH. Peter Anvin	  trust the BIOS to get all its memory reservations and usages
1710d0cd7425SH. Peter Anvin	  right.  If you know your BIOS have problems beyond the
1711d0cd7425SH. Peter Anvin	  default 64K area, you can set this to 640 to avoid using the
1712d0cd7425SH. Peter Anvin	  entire low memory range.
1713d0cd7425SH. Peter Anvin
1714d0cd7425SH. Peter Anvin	  If you have doubts about the BIOS (e.g. suspend/resume does
1715d0cd7425SH. Peter Anvin	  not work or there's kernel crashes after certain hardware
1716d0cd7425SH. Peter Anvin	  hotplug events) then you might want to enable
1717d0cd7425SH. Peter Anvin	  X86_CHECK_BIOS_CORRUPTION=y to allow the kernel to check
1718d0cd7425SH. Peter Anvin	  typical corruption patterns.
1719d0cd7425SH. Peter Anvin
1720d0cd7425SH. Peter Anvin	  Leave this to the default value of 64 if you are unsure.
1721fc381519SIngo Molnar
1722506f1d07SSam Ravnborgconfig MATH_EMULATION
1723506f1d07SSam Ravnborg	bool
1724a5b9e5a2SAndy Lutomirski	depends on MODIFY_LDT_SYSCALL
172587d6021bSArnd Bergmann	prompt "Math emulation" if X86_32 && (M486SX || MELAN)
1726a7f7f624SMasahiro Yamada	help
1727506f1d07SSam Ravnborg	  Linux can emulate a math coprocessor (used for floating point
1728506f1d07SSam Ravnborg	  operations) if you don't have one. 486DX and Pentium processors have
1729506f1d07SSam Ravnborg	  a math coprocessor built in, 486SX and 386 do not, unless you added
1730506f1d07SSam Ravnborg	  a 487DX or 387, respectively. (The messages during boot time can
1731506f1d07SSam Ravnborg	  give you some hints here ["man dmesg"].) Everyone needs either a
1732506f1d07SSam Ravnborg	  coprocessor or this emulation.
1733506f1d07SSam Ravnborg
1734506f1d07SSam Ravnborg	  If you don't have a math coprocessor, you need to say Y here; if you
1735506f1d07SSam Ravnborg	  say Y here even though you have a coprocessor, the coprocessor will
1736506f1d07SSam Ravnborg	  be used nevertheless. (This behavior can be changed with the kernel
1737506f1d07SSam Ravnborg	  command line option "no387", which comes handy if your coprocessor
1738506f1d07SSam Ravnborg	  is broken. Try "man bootparam" or see the documentation of your boot
1739506f1d07SSam Ravnborg	  loader (lilo or loadlin) about how to pass options to the kernel at
1740506f1d07SSam Ravnborg	  boot time.) This means that it is a good idea to say Y here if you
1741506f1d07SSam Ravnborg	  intend to use this kernel on different machines.
1742506f1d07SSam Ravnborg
1743506f1d07SSam Ravnborg	  More information about the internals of the Linux math coprocessor
1744506f1d07SSam Ravnborg	  emulation can be found in <file:arch/x86/math-emu/README>.
1745506f1d07SSam Ravnborg
1746506f1d07SSam Ravnborg	  If you are not sure, say Y; apart from resulting in a 66 KB bigger
1747506f1d07SSam Ravnborg	  kernel, it won't hurt.
1748506f1d07SSam Ravnborg
1749506f1d07SSam Ravnborgconfig MTRR
17506fc108a0SJan Beulich	def_bool y
17516a108a14SDavid Rientjes	prompt "MTRR (Memory Type Range Register) support" if EXPERT
1752a7f7f624SMasahiro Yamada	help
1753506f1d07SSam Ravnborg	  On Intel P6 family processors (Pentium Pro, Pentium II and later)
1754506f1d07SSam Ravnborg	  the Memory Type Range Registers (MTRRs) may be used to control
1755506f1d07SSam Ravnborg	  processor access to memory ranges. This is most useful if you have
1756506f1d07SSam Ravnborg	  a video (VGA) card on a PCI or AGP bus. Enabling write-combining
1757506f1d07SSam Ravnborg	  allows bus write transfers to be combined into a larger transfer
1758506f1d07SSam Ravnborg	  before bursting over the PCI/AGP bus. This can increase performance
1759506f1d07SSam Ravnborg	  of image write operations 2.5 times or more. Saying Y here creates a
1760506f1d07SSam Ravnborg	  /proc/mtrr file which may be used to manipulate your processor's
1761506f1d07SSam Ravnborg	  MTRRs. Typically the X server should use this.
1762506f1d07SSam Ravnborg
1763506f1d07SSam Ravnborg	  This code has a reasonably generic interface so that similar
1764506f1d07SSam Ravnborg	  control registers on other processors can be easily supported
1765506f1d07SSam Ravnborg	  as well:
1766506f1d07SSam Ravnborg
1767506f1d07SSam Ravnborg	  The Cyrix 6x86, 6x86MX and M II processors have Address Range
1768506f1d07SSam Ravnborg	  Registers (ARRs) which provide a similar functionality to MTRRs. For
1769506f1d07SSam Ravnborg	  these, the ARRs are used to emulate the MTRRs.
1770506f1d07SSam Ravnborg	  The AMD K6-2 (stepping 8 and above) and K6-3 processors have two
1771506f1d07SSam Ravnborg	  MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing
1772506f1d07SSam Ravnborg	  write-combining. All of these processors are supported by this code
1773506f1d07SSam Ravnborg	  and it makes sense to say Y here if you have one of them.
1774506f1d07SSam Ravnborg
1775506f1d07SSam Ravnborg	  Saying Y here also fixes a problem with buggy SMP BIOSes which only
1776506f1d07SSam Ravnborg	  set the MTRRs for the boot CPU and not for the secondary CPUs. This
1777506f1d07SSam Ravnborg	  can lead to all sorts of problems, so it's good to say Y here.
1778506f1d07SSam Ravnborg
1779506f1d07SSam Ravnborg	  You can safely say Y even if your machine doesn't have MTRRs, you'll
1780506f1d07SSam Ravnborg	  just add about 9 KB to your kernel.
1781506f1d07SSam Ravnborg
1782cb1aaebeSMauro Carvalho Chehab	  See <file:Documentation/x86/mtrr.rst> for more information.
1783506f1d07SSam Ravnborg
178495ffa243SYinghai Luconfig MTRR_SANITIZER
17852ffb3501SYinghai Lu	def_bool y
178695ffa243SYinghai Lu	prompt "MTRR cleanup support"
178795ffa243SYinghai Lu	depends on MTRR
1788a7f7f624SMasahiro Yamada	help
1789aba3728cSThomas Gleixner	  Convert MTRR layout from continuous to discrete, so X drivers can
1790aba3728cSThomas Gleixner	  add writeback entries.
179195ffa243SYinghai Lu
1792aba3728cSThomas Gleixner	  Can be disabled with disable_mtrr_cleanup on the kernel command line.
1793692105b8SMatt LaPlante	  The largest mtrr entry size for a continuous block can be set with
1794aba3728cSThomas Gleixner	  mtrr_chunk_size.
179595ffa243SYinghai Lu
17962ffb3501SYinghai Lu	  If unsure, say Y.
179795ffa243SYinghai Lu
179895ffa243SYinghai Luconfig MTRR_SANITIZER_ENABLE_DEFAULT
1799f5098d62SYinghai Lu	int "MTRR cleanup enable value (0-1)"
1800f5098d62SYinghai Lu	range 0 1
1801f5098d62SYinghai Lu	default "0"
180295ffa243SYinghai Lu	depends on MTRR_SANITIZER
1803a7f7f624SMasahiro Yamada	help
1804f5098d62SYinghai Lu	  Enable mtrr cleanup default value
180595ffa243SYinghai Lu
180612031a62SYinghai Luconfig MTRR_SANITIZER_SPARE_REG_NR_DEFAULT
180712031a62SYinghai Lu	int "MTRR cleanup spare reg num (0-7)"
180812031a62SYinghai Lu	range 0 7
180912031a62SYinghai Lu	default "1"
181012031a62SYinghai Lu	depends on MTRR_SANITIZER
1811a7f7f624SMasahiro Yamada	help
181212031a62SYinghai Lu	  mtrr cleanup spare entries default, it can be changed via
1813aba3728cSThomas Gleixner	  mtrr_spare_reg_nr=N on the kernel command line.
181412031a62SYinghai Lu
18152e5d9c85Svenkatesh.pallipadi@intel.comconfig X86_PAT
18166fc108a0SJan Beulich	def_bool y
18176a108a14SDavid Rientjes	prompt "x86 PAT support" if EXPERT
18182a8a2719SIngo Molnar	depends on MTRR
1819a7f7f624SMasahiro Yamada	help
18202e5d9c85Svenkatesh.pallipadi@intel.com	  Use PAT attributes to setup page level cache control.
1821042b78e4SVenki Pallipadi
18222e5d9c85Svenkatesh.pallipadi@intel.com	  PATs are the modern equivalents of MTRRs and are much more
18232e5d9c85Svenkatesh.pallipadi@intel.com	  flexible than MTRRs.
18242e5d9c85Svenkatesh.pallipadi@intel.com
18252e5d9c85Svenkatesh.pallipadi@intel.com	  Say N here if you see bootup problems (boot crash, boot hang,
1826042b78e4SVenki Pallipadi	  spontaneous reboots) or a non-working video driver.
18272e5d9c85Svenkatesh.pallipadi@intel.com
18282e5d9c85Svenkatesh.pallipadi@intel.com	  If unsure, say Y.
18292e5d9c85Svenkatesh.pallipadi@intel.com
183046cf98cdSVenkatesh Pallipadiconfig ARCH_USES_PG_UNCACHED
183146cf98cdSVenkatesh Pallipadi	def_bool y
183246cf98cdSVenkatesh Pallipadi	depends on X86_PAT
183346cf98cdSVenkatesh Pallipadi
1834628c6246SH. Peter Anvinconfig ARCH_RANDOM
1835628c6246SH. Peter Anvin	def_bool y
1836628c6246SH. Peter Anvin	prompt "x86 architectural random number generator" if EXPERT
1837a7f7f624SMasahiro Yamada	help
1838628c6246SH. Peter Anvin	  Enable the x86 architectural RDRAND instruction
1839628c6246SH. Peter Anvin	  (Intel Bull Mountain technology) to generate random numbers.
1840628c6246SH. Peter Anvin	  If supported, this is a high bandwidth, cryptographically
1841628c6246SH. Peter Anvin	  secure hardware random number generator.
1842628c6246SH. Peter Anvin
184351ae4a2dSH. Peter Anvinconfig X86_SMAP
184451ae4a2dSH. Peter Anvin	def_bool y
184551ae4a2dSH. Peter Anvin	prompt "Supervisor Mode Access Prevention" if EXPERT
1846a7f7f624SMasahiro Yamada	help
184751ae4a2dSH. Peter Anvin	  Supervisor Mode Access Prevention (SMAP) is a security
184851ae4a2dSH. Peter Anvin	  feature in newer Intel processors.  There is a small
184951ae4a2dSH. Peter Anvin	  performance cost if this enabled and turned on; there is
185051ae4a2dSH. Peter Anvin	  also a small increase in the kernel size if this is enabled.
185151ae4a2dSH. Peter Anvin
185251ae4a2dSH. Peter Anvin	  If unsure, say Y.
185351ae4a2dSH. Peter Anvin
1854b971880fSBabu Mogerconfig X86_UMIP
1855796ebc81SRicardo Neri	def_bool y
1856b971880fSBabu Moger	prompt "User Mode Instruction Prevention" if EXPERT
1857a7f7f624SMasahiro Yamada	help
1858b971880fSBabu Moger	  User Mode Instruction Prevention (UMIP) is a security feature in
1859b971880fSBabu Moger	  some x86 processors. If enabled, a general protection fault is
1860b971880fSBabu Moger	  issued if the SGDT, SLDT, SIDT, SMSW or STR instructions are
1861b971880fSBabu Moger	  executed in user mode. These instructions unnecessarily expose
1862b971880fSBabu Moger	  information about the hardware state.
1863796ebc81SRicardo Neri
1864796ebc81SRicardo Neri	  The vast majority of applications do not use these instructions.
1865796ebc81SRicardo Neri	  For the very few that do, software emulation is provided in
1866796ebc81SRicardo Neri	  specific cases in protected and virtual-8086 modes. Emulated
1867796ebc81SRicardo Neri	  results are dummy.
1868aa35f896SRicardo Neri
186935e97790SDave Hansenconfig X86_INTEL_MEMORY_PROTECTION_KEYS
187038f3e775SBabu Moger	prompt "Memory Protection Keys"
187135e97790SDave Hansen	def_bool y
1872284244a9SDave Hansen	# Note: only available in 64-bit mode
187338f3e775SBabu Moger	depends on X86_64 && (CPU_SUP_INTEL || CPU_SUP_AMD)
187452c8e601SIngo Molnar	select ARCH_USES_HIGH_VMA_FLAGS
187552c8e601SIngo Molnar	select ARCH_HAS_PKEYS
1876a7f7f624SMasahiro Yamada	help
1877284244a9SDave Hansen	  Memory Protection Keys provides a mechanism for enforcing
1878284244a9SDave Hansen	  page-based protections, but without requiring modification of the
1879284244a9SDave Hansen	  page tables when an application changes protection domains.
1880284244a9SDave Hansen
18811eecbcdcSMauro Carvalho Chehab	  For details, see Documentation/core-api/protection-keys.rst
1882284244a9SDave Hansen
1883284244a9SDave Hansen	  If unsure, say y.
188435e97790SDave Hansen
1885db616173SMichal Hockochoice
1886db616173SMichal Hocko	prompt "TSX enable mode"
1887db616173SMichal Hocko	depends on CPU_SUP_INTEL
1888db616173SMichal Hocko	default X86_INTEL_TSX_MODE_OFF
1889db616173SMichal Hocko	help
1890db616173SMichal Hocko	  Intel's TSX (Transactional Synchronization Extensions) feature
1891db616173SMichal Hocko	  allows to optimize locking protocols through lock elision which
1892db616173SMichal Hocko	  can lead to a noticeable performance boost.
1893db616173SMichal Hocko
1894db616173SMichal Hocko	  On the other hand it has been shown that TSX can be exploited
1895db616173SMichal Hocko	  to form side channel attacks (e.g. TAA) and chances are there
1896db616173SMichal Hocko	  will be more of those attacks discovered in the future.
1897db616173SMichal Hocko
1898db616173SMichal Hocko	  Therefore TSX is not enabled by default (aka tsx=off). An admin
1899db616173SMichal Hocko	  might override this decision by tsx=on the command line parameter.
1900db616173SMichal Hocko	  Even with TSX enabled, the kernel will attempt to enable the best
1901db616173SMichal Hocko	  possible TAA mitigation setting depending on the microcode available
1902db616173SMichal Hocko	  for the particular machine.
1903db616173SMichal Hocko
1904db616173SMichal Hocko	  This option allows to set the default tsx mode between tsx=on, =off
1905db616173SMichal Hocko	  and =auto. See Documentation/admin-guide/kernel-parameters.txt for more
1906db616173SMichal Hocko	  details.
1907db616173SMichal Hocko
1908db616173SMichal Hocko	  Say off if not sure, auto if TSX is in use but it should be used on safe
1909db616173SMichal Hocko	  platforms or on if TSX is in use and the security aspect of tsx is not
1910db616173SMichal Hocko	  relevant.
1911db616173SMichal Hocko
1912db616173SMichal Hockoconfig X86_INTEL_TSX_MODE_OFF
1913db616173SMichal Hocko	bool "off"
1914db616173SMichal Hocko	help
1915db616173SMichal Hocko	  TSX is disabled if possible - equals to tsx=off command line parameter.
1916db616173SMichal Hocko
1917db616173SMichal Hockoconfig X86_INTEL_TSX_MODE_ON
1918db616173SMichal Hocko	bool "on"
1919db616173SMichal Hocko	help
1920db616173SMichal Hocko	  TSX is always enabled on TSX capable HW - equals the tsx=on command
1921db616173SMichal Hocko	  line parameter.
1922db616173SMichal Hocko
1923db616173SMichal Hockoconfig X86_INTEL_TSX_MODE_AUTO
1924db616173SMichal Hocko	bool "auto"
1925db616173SMichal Hocko	help
1926db616173SMichal Hocko	  TSX is enabled on TSX capable HW that is believed to be safe against
1927db616173SMichal Hocko	  side channel attacks- equals the tsx=auto command line parameter.
1928db616173SMichal Hockoendchoice
1929db616173SMichal Hocko
1930506f1d07SSam Ravnborgconfig EFI
19319ba16087SJan Beulich	bool "EFI runtime service support"
19325b83683fSHuang, Ying	depends on ACPI
1933f6ce5002SSergey Vlasov	select UCS2_STRING
1934022ee6c5SArd Biesheuvel	select EFI_RUNTIME_WRAPPERS
1935a7f7f624SMasahiro Yamada	help
19368b2cb7a8SHuang, Ying	  This enables the kernel to use EFI runtime services that are
1937506f1d07SSam Ravnborg	  available (such as the EFI variable services).
1938506f1d07SSam Ravnborg
19398b2cb7a8SHuang, Ying	  This option is only useful on systems that have EFI firmware.
19408b2cb7a8SHuang, Ying	  In addition, you should use the latest ELILO loader available
19418b2cb7a8SHuang, Ying	  at <http://elilo.sourceforge.net> in order to take advantage
19428b2cb7a8SHuang, Ying	  of EFI runtime services. However, even with this option, the
19438b2cb7a8SHuang, Ying	  resultant kernel should continue to boot on existing non-EFI
19448b2cb7a8SHuang, Ying	  platforms.
1945506f1d07SSam Ravnborg
1946291f3632SMatt Flemingconfig EFI_STUB
1947291f3632SMatt Fleming	bool "EFI stub support"
1948b16d8c23SMatt Fleming	depends on EFI && !X86_USE_3DNOW
19498f24f8c2SArd Biesheuvel	depends on $(cc-option,-mabi=ms) || X86_32
19507b2a583aSMatt Fleming	select RELOCATABLE
1951a7f7f624SMasahiro Yamada	help
1952291f3632SMatt Fleming	  This kernel feature allows a bzImage to be loaded directly
1953291f3632SMatt Fleming	  by EFI firmware without the use of a bootloader.
1954291f3632SMatt Fleming
19554f4cfa6cSMauro Carvalho Chehab	  See Documentation/admin-guide/efi-stub.rst for more information.
19560c759662SMatt Fleming
19577d453eeeSMatt Flemingconfig EFI_MIXED
19587d453eeeSMatt Fleming	bool "EFI mixed-mode support"
19597d453eeeSMatt Fleming	depends on EFI_STUB && X86_64
1960a7f7f624SMasahiro Yamada	help
19617d453eeeSMatt Fleming	   Enabling this feature allows a 64-bit kernel to be booted
19627d453eeeSMatt Fleming	   on a 32-bit firmware, provided that your CPU supports 64-bit
19637d453eeeSMatt Fleming	   mode.
19647d453eeeSMatt Fleming
19657d453eeeSMatt Fleming	   Note that it is not possible to boot a mixed-mode enabled
19667d453eeeSMatt Fleming	   kernel via the EFI boot stub - a bootloader that supports
19677d453eeeSMatt Fleming	   the EFI handover protocol must be used.
19687d453eeeSMatt Fleming
19697d453eeeSMatt Fleming	   If unsure, say N.
19707d453eeeSMatt Fleming
1971506f1d07SSam Ravnborgconfig SECCOMP
19723c2362e6SHarvey Harrison	def_bool y
19733c2362e6SHarvey Harrison	prompt "Enable seccomp to safely compute untrusted bytecode"
1974a7f7f624SMasahiro Yamada	help
1975506f1d07SSam Ravnborg	  This kernel feature is useful for number crunching applications
1976506f1d07SSam Ravnborg	  that may need to compute untrusted bytecode during their
1977506f1d07SSam Ravnborg	  execution. By using pipes or other transports made available to
1978506f1d07SSam Ravnborg	  the process as file descriptors supporting the read/write
1979506f1d07SSam Ravnborg	  syscalls, it's possible to isolate those applications in
1980506f1d07SSam Ravnborg	  their own address space using seccomp. Once seccomp is
19819c0bbee8SAlexey Dobriyan	  enabled via prctl(PR_SET_SECCOMP), it cannot be disabled
1982506f1d07SSam Ravnborg	  and the task is only allowed to execute a few safe syscalls
1983506f1d07SSam Ravnborg	  defined by each seccomp mode.
1984506f1d07SSam Ravnborg
1985506f1d07SSam Ravnborg	  If unsure, say Y. Only embedded should say N here.
1986506f1d07SSam Ravnborg
19878636a1f9SMasahiro Yamadasource "kernel/Kconfig.hz"
1988506f1d07SSam Ravnborg
1989506f1d07SSam Ravnborgconfig KEXEC
1990506f1d07SSam Ravnborg	bool "kexec system call"
19912965faa5SDave Young	select KEXEC_CORE
1992a7f7f624SMasahiro Yamada	help
1993506f1d07SSam Ravnborg	  kexec is a system call that implements the ability to shutdown your
1994506f1d07SSam Ravnborg	  current kernel, and to start another kernel.  It is like a reboot
1995506f1d07SSam Ravnborg	  but it is independent of the system firmware.   And like a reboot
1996506f1d07SSam Ravnborg	  you can start any kernel with it, not just Linux.
1997506f1d07SSam Ravnborg
1998506f1d07SSam Ravnborg	  The name comes from the similarity to the exec system call.
1999506f1d07SSam Ravnborg
2000506f1d07SSam Ravnborg	  It is an ongoing process to be certain the hardware in a machine
2001506f1d07SSam Ravnborg	  is properly shutdown, so do not be surprised if this code does not
2002bf220695SGeert Uytterhoeven	  initially work for you.  As of this writing the exact hardware
2003bf220695SGeert Uytterhoeven	  interface is strongly in flux, so no good recommendation can be
2004bf220695SGeert Uytterhoeven	  made.
2005506f1d07SSam Ravnborg
200674ca317cSVivek Goyalconfig KEXEC_FILE
200774ca317cSVivek Goyal	bool "kexec file based system call"
20082965faa5SDave Young	select KEXEC_CORE
200974ca317cSVivek Goyal	select BUILD_BIN2C
201074ca317cSVivek Goyal	depends on X86_64
201174ca317cSVivek Goyal	depends on CRYPTO=y
201274ca317cSVivek Goyal	depends on CRYPTO_SHA256=y
2013a7f7f624SMasahiro Yamada	help
201474ca317cSVivek Goyal	  This is new version of kexec system call. This system call is
201574ca317cSVivek Goyal	  file based and takes file descriptors as system call argument
201674ca317cSVivek Goyal	  for kernel and initramfs as opposed to list of segments as
201774ca317cSVivek Goyal	  accepted by previous system call.
201874ca317cSVivek Goyal
2019b799a09fSAKASHI Takahiroconfig ARCH_HAS_KEXEC_PURGATORY
2020b799a09fSAKASHI Takahiro	def_bool KEXEC_FILE
2021b799a09fSAKASHI Takahiro
202299d5cadfSJiri Bohacconfig KEXEC_SIG
20238e7d8381SVivek Goyal	bool "Verify kernel signature during kexec_file_load() syscall"
202474ca317cSVivek Goyal	depends on KEXEC_FILE
2025a7f7f624SMasahiro Yamada	help
202699d5cadfSJiri Bohac
202799d5cadfSJiri Bohac	  This option makes the kexec_file_load() syscall check for a valid
202899d5cadfSJiri Bohac	  signature of the kernel image.  The image can still be loaded without
202999d5cadfSJiri Bohac	  a valid signature unless you also enable KEXEC_SIG_FORCE, though if
203099d5cadfSJiri Bohac	  there's a signature that we can check, then it must be valid.
203199d5cadfSJiri Bohac
203299d5cadfSJiri Bohac	  In addition to this option, you need to enable signature
203399d5cadfSJiri Bohac	  verification for the corresponding kernel image type being
203499d5cadfSJiri Bohac	  loaded in order for this to work.
203599d5cadfSJiri Bohac
203699d5cadfSJiri Bohacconfig KEXEC_SIG_FORCE
203799d5cadfSJiri Bohac	bool "Require a valid signature in kexec_file_load() syscall"
203899d5cadfSJiri Bohac	depends on KEXEC_SIG
2039a7f7f624SMasahiro Yamada	help
20408e7d8381SVivek Goyal	  This option makes kernel signature verification mandatory for
2041d8eb8940SBorislav Petkov	  the kexec_file_load() syscall.
20428e7d8381SVivek Goyal
20438e7d8381SVivek Goyalconfig KEXEC_BZIMAGE_VERIFY_SIG
20448e7d8381SVivek Goyal	bool "Enable bzImage signature verification support"
204599d5cadfSJiri Bohac	depends on KEXEC_SIG
20468e7d8381SVivek Goyal	depends on SIGNED_PE_FILE_VERIFICATION
20478e7d8381SVivek Goyal	select SYSTEM_TRUSTED_KEYRING
2048a7f7f624SMasahiro Yamada	help
20498e7d8381SVivek Goyal	  Enable bzImage signature verification support.
20508e7d8381SVivek Goyal
2051506f1d07SSam Ravnborgconfig CRASH_DUMP
205204b69447SPavel Machek	bool "kernel crash dumps"
2053506f1d07SSam Ravnborg	depends on X86_64 || (X86_32 && HIGHMEM)
2054a7f7f624SMasahiro Yamada	help
2055506f1d07SSam Ravnborg	  Generate crash dump after being started by kexec.
2056506f1d07SSam Ravnborg	  This should be normally only set in special crash dump kernels
2057506f1d07SSam Ravnborg	  which are loaded in the main kernel with kexec-tools into
2058506f1d07SSam Ravnborg	  a specially reserved region and then later executed after
2059506f1d07SSam Ravnborg	  a crash by kdump/kexec. The crash dump kernel must be compiled
2060506f1d07SSam Ravnborg	  to a memory address not used by the main kernel or BIOS using
2061506f1d07SSam Ravnborg	  PHYSICAL_START, or it must be built as a relocatable image
2062506f1d07SSam Ravnborg	  (CONFIG_RELOCATABLE=y).
2063330d4810SMauro Carvalho Chehab	  For more details see Documentation/admin-guide/kdump/kdump.rst
2064506f1d07SSam Ravnborg
20653ab83521SHuang Yingconfig KEXEC_JUMP
20666ea30386SKees Cook	bool "kexec jump"
2067fee7b0d8SHuang Ying	depends on KEXEC && HIBERNATION
2068a7f7f624SMasahiro Yamada	help
206989081d17SHuang Ying	  Jump between original kernel and kexeced kernel and invoke
207089081d17SHuang Ying	  code in physical address mode via KEXEC
20713ab83521SHuang Ying
2072506f1d07SSam Ravnborgconfig PHYSICAL_START
20736a108a14SDavid Rientjes	hex "Physical address where the kernel is loaded" if (EXPERT || CRASH_DUMP)
2074ceefccc9SH. Peter Anvin	default "0x1000000"
2075a7f7f624SMasahiro Yamada	help
2076506f1d07SSam Ravnborg	  This gives the physical address where the kernel is loaded.
2077506f1d07SSam Ravnborg
2078506f1d07SSam Ravnborg	  If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then
2079506f1d07SSam Ravnborg	  bzImage will decompress itself to above physical address and
2080506f1d07SSam Ravnborg	  run from there. Otherwise, bzImage will run from the address where
2081506f1d07SSam Ravnborg	  it has been loaded by the boot loader and will ignore above physical
2082506f1d07SSam Ravnborg	  address.
2083506f1d07SSam Ravnborg
2084506f1d07SSam Ravnborg	  In normal kdump cases one does not have to set/change this option
2085506f1d07SSam Ravnborg	  as now bzImage can be compiled as a completely relocatable image
2086506f1d07SSam Ravnborg	  (CONFIG_RELOCATABLE=y) and be used to load and run from a different
2087506f1d07SSam Ravnborg	  address. This option is mainly useful for the folks who don't want
2088506f1d07SSam Ravnborg	  to use a bzImage for capturing the crash dump and want to use a
2089506f1d07SSam Ravnborg	  vmlinux instead. vmlinux is not relocatable hence a kernel needs
2090506f1d07SSam Ravnborg	  to be specifically compiled to run from a specific memory area
2091506f1d07SSam Ravnborg	  (normally a reserved region) and this option comes handy.
2092506f1d07SSam Ravnborg
2093ceefccc9SH. Peter Anvin	  So if you are using bzImage for capturing the crash dump,
2094ceefccc9SH. Peter Anvin	  leave the value here unchanged to 0x1000000 and set
2095ceefccc9SH. Peter Anvin	  CONFIG_RELOCATABLE=y.  Otherwise if you plan to use vmlinux
2096ceefccc9SH. Peter Anvin	  for capturing the crash dump change this value to start of
2097ceefccc9SH. Peter Anvin	  the reserved region.  In other words, it can be set based on
2098ceefccc9SH. Peter Anvin	  the "X" value as specified in the "crashkernel=YM@XM"
2099ceefccc9SH. Peter Anvin	  command line boot parameter passed to the panic-ed
2100330d4810SMauro Carvalho Chehab	  kernel. Please take a look at Documentation/admin-guide/kdump/kdump.rst
2101ceefccc9SH. Peter Anvin	  for more details about crash dumps.
2102506f1d07SSam Ravnborg
2103506f1d07SSam Ravnborg	  Usage of bzImage for capturing the crash dump is recommended as
2104506f1d07SSam Ravnborg	  one does not have to build two kernels. Same kernel can be used
2105506f1d07SSam Ravnborg	  as production kernel and capture kernel. Above option should have
2106506f1d07SSam Ravnborg	  gone away after relocatable bzImage support is introduced. But it
2107506f1d07SSam Ravnborg	  is present because there are users out there who continue to use
2108506f1d07SSam Ravnborg	  vmlinux for dump capture. This option should go away down the
2109506f1d07SSam Ravnborg	  line.
2110506f1d07SSam Ravnborg
2111506f1d07SSam Ravnborg	  Don't change this unless you know what you are doing.
2112506f1d07SSam Ravnborg
2113506f1d07SSam Ravnborgconfig RELOCATABLE
211426717808SH. Peter Anvin	bool "Build a relocatable kernel"
211526717808SH. Peter Anvin	default y
2116a7f7f624SMasahiro Yamada	help
2117506f1d07SSam Ravnborg	  This builds a kernel image that retains relocation information
2118506f1d07SSam Ravnborg	  so it can be loaded someplace besides the default 1MB.
2119506f1d07SSam Ravnborg	  The relocations tend to make the kernel binary about 10% larger,
2120506f1d07SSam Ravnborg	  but are discarded at runtime.
2121506f1d07SSam Ravnborg
2122506f1d07SSam Ravnborg	  One use is for the kexec on panic case where the recovery kernel
2123506f1d07SSam Ravnborg	  must live at a different physical address than the primary
2124506f1d07SSam Ravnborg	  kernel.
2125506f1d07SSam Ravnborg
2126506f1d07SSam Ravnborg	  Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address
2127506f1d07SSam Ravnborg	  it has been loaded at and the compile time physical address
21288ab3820fSKees Cook	  (CONFIG_PHYSICAL_START) is used as the minimum location.
2129506f1d07SSam Ravnborg
21308ab3820fSKees Cookconfig RANDOMIZE_BASE
2131e8581e3dSBaoquan He	bool "Randomize the address of the kernel image (KASLR)"
21328ab3820fSKees Cook	depends on RELOCATABLE
21336807c846SIngo Molnar	default y
2134a7f7f624SMasahiro Yamada	help
2135e8581e3dSBaoquan He	  In support of Kernel Address Space Layout Randomization (KASLR),
2136e8581e3dSBaoquan He	  this randomizes the physical address at which the kernel image
2137e8581e3dSBaoquan He	  is decompressed and the virtual address where the kernel
2138e8581e3dSBaoquan He	  image is mapped, as a security feature that deters exploit
2139e8581e3dSBaoquan He	  attempts relying on knowledge of the location of kernel
2140e8581e3dSBaoquan He	  code internals.
2141e8581e3dSBaoquan He
2142ed9f007eSKees Cook	  On 64-bit, the kernel physical and virtual addresses are
2143ed9f007eSKees Cook	  randomized separately. The physical address will be anywhere
2144ed9f007eSKees Cook	  between 16MB and the top of physical memory (up to 64TB). The
2145ed9f007eSKees Cook	  virtual address will be randomized from 16MB up to 1GB (9 bits
2146ed9f007eSKees Cook	  of entropy). Note that this also reduces the memory space
2147ed9f007eSKees Cook	  available to kernel modules from 1.5GB to 1GB.
2148ed9f007eSKees Cook
2149ed9f007eSKees Cook	  On 32-bit, the kernel physical and virtual addresses are
2150ed9f007eSKees Cook	  randomized together. They will be randomized from 16MB up to
2151ed9f007eSKees Cook	  512MB (8 bits of entropy).
21528ab3820fSKees Cook
2153a653f356SKees Cook	  Entropy is generated using the RDRAND instruction if it is
2154e8581e3dSBaoquan He	  supported. If RDTSC is supported, its value is mixed into
2155e8581e3dSBaoquan He	  the entropy pool as well. If neither RDRAND nor RDTSC are
2156ed9f007eSKees Cook	  supported, then entropy is read from the i8254 timer. The
2157ed9f007eSKees Cook	  usable entropy is limited by the kernel being built using
2158ed9f007eSKees Cook	  2GB addressing, and that PHYSICAL_ALIGN must be at a
2159ed9f007eSKees Cook	  minimum of 2MB. As a result, only 10 bits of entropy are
2160ed9f007eSKees Cook	  theoretically possible, but the implementations are further
2161ed9f007eSKees Cook	  limited due to memory layouts.
2162e8581e3dSBaoquan He
21636807c846SIngo Molnar	  If unsure, say Y.
2164da2b6fb9SKees Cook
21658ab3820fSKees Cook# Relocation on x86 needs some additional build support
2166845adf72SH. Peter Anvinconfig X86_NEED_RELOCS
2167845adf72SH. Peter Anvin	def_bool y
21688ab3820fSKees Cook	depends on RANDOMIZE_BASE || (X86_32 && RELOCATABLE)
2169845adf72SH. Peter Anvin
2170506f1d07SSam Ravnborgconfig PHYSICAL_ALIGN
2171a0215061SKees Cook	hex "Alignment value to which kernel should be aligned"
21728ab3820fSKees Cook	default "0x200000"
2173a0215061SKees Cook	range 0x2000 0x1000000 if X86_32
2174a0215061SKees Cook	range 0x200000 0x1000000 if X86_64
2175a7f7f624SMasahiro Yamada	help
2176506f1d07SSam Ravnborg	  This value puts the alignment restrictions on physical address
2177506f1d07SSam Ravnborg	  where kernel is loaded and run from. Kernel is compiled for an
2178506f1d07SSam Ravnborg	  address which meets above alignment restriction.
2179506f1d07SSam Ravnborg
2180506f1d07SSam Ravnborg	  If bootloader loads the kernel at a non-aligned address and
2181506f1d07SSam Ravnborg	  CONFIG_RELOCATABLE is set, kernel will move itself to nearest
2182506f1d07SSam Ravnborg	  address aligned to above value and run from there.
2183506f1d07SSam Ravnborg
2184506f1d07SSam Ravnborg	  If bootloader loads the kernel at a non-aligned address and
2185506f1d07SSam Ravnborg	  CONFIG_RELOCATABLE is not set, kernel will ignore the run time
2186506f1d07SSam Ravnborg	  load address and decompress itself to the address it has been
2187506f1d07SSam Ravnborg	  compiled for and run from there. The address for which kernel is
2188506f1d07SSam Ravnborg	  compiled already meets above alignment restrictions. Hence the
2189506f1d07SSam Ravnborg	  end result is that kernel runs from a physical address meeting
2190506f1d07SSam Ravnborg	  above alignment restrictions.
2191506f1d07SSam Ravnborg
2192a0215061SKees Cook	  On 32-bit this value must be a multiple of 0x2000. On 64-bit
2193a0215061SKees Cook	  this value must be a multiple of 0x200000.
2194a0215061SKees Cook
2195506f1d07SSam Ravnborg	  Don't change this unless you know what you are doing.
2196506f1d07SSam Ravnborg
2197eedb92abSKirill A. Shutemovconfig DYNAMIC_MEMORY_LAYOUT
2198eedb92abSKirill A. Shutemov	bool
2199a7f7f624SMasahiro Yamada	help
2200eedb92abSKirill A. Shutemov	  This option makes base addresses of vmalloc and vmemmap as well as
2201eedb92abSKirill A. Shutemov	  __PAGE_OFFSET movable during boot.
2202eedb92abSKirill A. Shutemov
22030483e1faSThomas Garnierconfig RANDOMIZE_MEMORY
22040483e1faSThomas Garnier	bool "Randomize the kernel memory sections"
22050483e1faSThomas Garnier	depends on X86_64
22060483e1faSThomas Garnier	depends on RANDOMIZE_BASE
2207eedb92abSKirill A. Shutemov	select DYNAMIC_MEMORY_LAYOUT
22080483e1faSThomas Garnier	default RANDOMIZE_BASE
2209a7f7f624SMasahiro Yamada	help
22100483e1faSThomas Garnier	   Randomizes the base virtual address of kernel memory sections
22110483e1faSThomas Garnier	   (physical memory mapping, vmalloc & vmemmap). This security feature
22120483e1faSThomas Garnier	   makes exploits relying on predictable memory locations less reliable.
22130483e1faSThomas Garnier
22140483e1faSThomas Garnier	   The order of allocations remains unchanged. Entropy is generated in
22150483e1faSThomas Garnier	   the same way as RANDOMIZE_BASE. Current implementation in the optimal
22160483e1faSThomas Garnier	   configuration have in average 30,000 different possible virtual
22170483e1faSThomas Garnier	   addresses for each memory section.
22180483e1faSThomas Garnier
22196807c846SIngo Molnar	   If unsure, say Y.
22200483e1faSThomas Garnier
222190397a41SThomas Garnierconfig RANDOMIZE_MEMORY_PHYSICAL_PADDING
222290397a41SThomas Garnier	hex "Physical memory mapping padding" if EXPERT
222390397a41SThomas Garnier	depends on RANDOMIZE_MEMORY
222490397a41SThomas Garnier	default "0xa" if MEMORY_HOTPLUG
222590397a41SThomas Garnier	default "0x0"
222690397a41SThomas Garnier	range 0x1 0x40 if MEMORY_HOTPLUG
222790397a41SThomas Garnier	range 0x0 0x40
2228a7f7f624SMasahiro Yamada	help
222990397a41SThomas Garnier	   Define the padding in terabytes added to the existing physical
223090397a41SThomas Garnier	   memory size during kernel memory randomization. It is useful
223190397a41SThomas Garnier	   for memory hotplug support but reduces the entropy available for
223290397a41SThomas Garnier	   address randomization.
223390397a41SThomas Garnier
223490397a41SThomas Garnier	   If unsure, leave at the default value.
223590397a41SThomas Garnier
2236506f1d07SSam Ravnborgconfig HOTPLUG_CPU
2237bebd024eSThomas Gleixner	def_bool y
223840b31360SStephen Rothwell	depends on SMP
2239506f1d07SSam Ravnborg
224080aa1dffSFenghua Yuconfig BOOTPARAM_HOTPLUG_CPU0
224180aa1dffSFenghua Yu	bool "Set default setting of cpu0_hotpluggable"
22422c922cd0SKees Cook	depends on HOTPLUG_CPU
2243a7f7f624SMasahiro Yamada	help
224480aa1dffSFenghua Yu	  Set whether default state of cpu0_hotpluggable is on or off.
224580aa1dffSFenghua Yu
224680aa1dffSFenghua Yu	  Say Y here to enable CPU0 hotplug by default. If this switch
224780aa1dffSFenghua Yu	  is turned on, there is no need to give cpu0_hotplug kernel
224880aa1dffSFenghua Yu	  parameter and the CPU0 hotplug feature is enabled by default.
224980aa1dffSFenghua Yu
225080aa1dffSFenghua Yu	  Please note: there are two known CPU0 dependencies if you want
225180aa1dffSFenghua Yu	  to enable the CPU0 hotplug feature either by this switch or by
225280aa1dffSFenghua Yu	  cpu0_hotplug kernel parameter.
225380aa1dffSFenghua Yu
225480aa1dffSFenghua Yu	  First, resume from hibernate or suspend always starts from CPU0.
225580aa1dffSFenghua Yu	  So hibernate and suspend are prevented if CPU0 is offline.
225680aa1dffSFenghua Yu
225780aa1dffSFenghua Yu	  Second dependency is PIC interrupts always go to CPU0. CPU0 can not
225880aa1dffSFenghua Yu	  offline if any interrupt can not migrate out of CPU0. There may
225980aa1dffSFenghua Yu	  be other CPU0 dependencies.
226080aa1dffSFenghua Yu
226180aa1dffSFenghua Yu	  Please make sure the dependencies are under your control before
226280aa1dffSFenghua Yu	  you enable this feature.
226380aa1dffSFenghua Yu
226480aa1dffSFenghua Yu	  Say N if you don't want to enable CPU0 hotplug feature by default.
226580aa1dffSFenghua Yu	  You still can enable the CPU0 hotplug feature at boot by kernel
226680aa1dffSFenghua Yu	  parameter cpu0_hotplug.
226780aa1dffSFenghua Yu
2268a71c8bc5SFenghua Yuconfig DEBUG_HOTPLUG_CPU0
2269a71c8bc5SFenghua Yu	def_bool n
2270a71c8bc5SFenghua Yu	prompt "Debug CPU0 hotplug"
22712c922cd0SKees Cook	depends on HOTPLUG_CPU
2272a7f7f624SMasahiro Yamada	help
2273a71c8bc5SFenghua Yu	  Enabling this option offlines CPU0 (if CPU0 can be offlined) as
2274a71c8bc5SFenghua Yu	  soon as possible and boots up userspace with CPU0 offlined. User
2275a71c8bc5SFenghua Yu	  can online CPU0 back after boot time.
2276a71c8bc5SFenghua Yu
2277a71c8bc5SFenghua Yu	  To debug CPU0 hotplug, you need to enable CPU0 offline/online
2278a71c8bc5SFenghua Yu	  feature by either turning on CONFIG_BOOTPARAM_HOTPLUG_CPU0 during
2279a71c8bc5SFenghua Yu	  compilation or giving cpu0_hotplug kernel parameter at boot.
2280a71c8bc5SFenghua Yu
2281a71c8bc5SFenghua Yu	  If unsure, say N.
2282a71c8bc5SFenghua Yu
2283506f1d07SSam Ravnborgconfig COMPAT_VDSO
2284b0b49f26SAndy Lutomirski	def_bool n
2285b0b49f26SAndy Lutomirski	prompt "Disable the 32-bit vDSO (needed for glibc 2.3.3)"
2286953fee1dSIngo Molnar	depends on COMPAT_32
2287a7f7f624SMasahiro Yamada	help
2288b0b49f26SAndy Lutomirski	  Certain buggy versions of glibc will crash if they are
2289b0b49f26SAndy Lutomirski	  presented with a 32-bit vDSO that is not mapped at the address
2290b0b49f26SAndy Lutomirski	  indicated in its segment table.
2291e84446deSRandy Dunlap
2292b0b49f26SAndy Lutomirski	  The bug was introduced by f866314b89d56845f55e6f365e18b31ec978ec3a
2293b0b49f26SAndy Lutomirski	  and fixed by 3b3ddb4f7db98ec9e912ccdf54d35df4aa30e04a and
2294b0b49f26SAndy Lutomirski	  49ad572a70b8aeb91e57483a11dd1b77e31c4468.  Glibc 2.3.3 is
2295b0b49f26SAndy Lutomirski	  the only released version with the bug, but OpenSUSE 9
2296b0b49f26SAndy Lutomirski	  contains a buggy "glibc 2.3.2".
2297506f1d07SSam Ravnborg
2298b0b49f26SAndy Lutomirski	  The symptom of the bug is that everything crashes on startup, saying:
2299b0b49f26SAndy Lutomirski	  dl_main: Assertion `(void *) ph->p_vaddr == _rtld_local._dl_sysinfo_dso' failed!
2300b0b49f26SAndy Lutomirski
2301b0b49f26SAndy Lutomirski	  Saying Y here changes the default value of the vdso32 boot
2302b0b49f26SAndy Lutomirski	  option from 1 to 0, which turns off the 32-bit vDSO entirely.
2303b0b49f26SAndy Lutomirski	  This works around the glibc bug but hurts performance.
2304b0b49f26SAndy Lutomirski
2305b0b49f26SAndy Lutomirski	  If unsure, say N: if you are compiling your own kernel, you
2306b0b49f26SAndy Lutomirski	  are unlikely to be using a buggy version of glibc.
2307506f1d07SSam Ravnborg
23083dc33bd3SKees Cookchoice
23093dc33bd3SKees Cook	prompt "vsyscall table for legacy applications"
23103dc33bd3SKees Cook	depends on X86_64
2311625b7b7fSAndy Lutomirski	default LEGACY_VSYSCALL_XONLY
23123dc33bd3SKees Cook	help
23133dc33bd3SKees Cook	  Legacy user code that does not know how to find the vDSO expects
23143dc33bd3SKees Cook	  to be able to issue three syscalls by calling fixed addresses in
23153dc33bd3SKees Cook	  kernel space. Since this location is not randomized with ASLR,
23163dc33bd3SKees Cook	  it can be used to assist security vulnerability exploitation.
23173dc33bd3SKees Cook
23183dc33bd3SKees Cook	  This setting can be changed at boot time via the kernel command
2319bd49e16eSAndy Lutomirski	  line parameter vsyscall=[emulate|xonly|none].
23203dc33bd3SKees Cook
23213dc33bd3SKees Cook	  On a system with recent enough glibc (2.14 or newer) and no
23223dc33bd3SKees Cook	  static binaries, you can say None without a performance penalty
23233dc33bd3SKees Cook	  to improve security.
23243dc33bd3SKees Cook
2325bd49e16eSAndy Lutomirski	  If unsure, select "Emulate execution only".
23263dc33bd3SKees Cook
23273dc33bd3SKees Cook	config LEGACY_VSYSCALL_EMULATE
2328bd49e16eSAndy Lutomirski		bool "Full emulation"
23293dc33bd3SKees Cook		help
2330bd49e16eSAndy Lutomirski		  The kernel traps and emulates calls into the fixed vsyscall
2331bd49e16eSAndy Lutomirski		  address mapping. This makes the mapping non-executable, but
2332bd49e16eSAndy Lutomirski		  it still contains readable known contents, which could be
2333bd49e16eSAndy Lutomirski		  used in certain rare security vulnerability exploits. This
2334bd49e16eSAndy Lutomirski		  configuration is recommended when using legacy userspace
2335bd49e16eSAndy Lutomirski		  that still uses vsyscalls along with legacy binary
2336bd49e16eSAndy Lutomirski		  instrumentation tools that require code to be readable.
2337bd49e16eSAndy Lutomirski
2338bd49e16eSAndy Lutomirski		  An example of this type of legacy userspace is running
2339bd49e16eSAndy Lutomirski		  Pin on an old binary that still uses vsyscalls.
2340bd49e16eSAndy Lutomirski
2341bd49e16eSAndy Lutomirski	config LEGACY_VSYSCALL_XONLY
2342bd49e16eSAndy Lutomirski		bool "Emulate execution only"
2343bd49e16eSAndy Lutomirski		help
2344bd49e16eSAndy Lutomirski		  The kernel traps and emulates calls into the fixed vsyscall
2345bd49e16eSAndy Lutomirski		  address mapping and does not allow reads.  This
2346bd49e16eSAndy Lutomirski		  configuration is recommended when userspace might use the
2347bd49e16eSAndy Lutomirski		  legacy vsyscall area but support for legacy binary
2348bd49e16eSAndy Lutomirski		  instrumentation of legacy code is not needed.  It mitigates
2349bd49e16eSAndy Lutomirski		  certain uses of the vsyscall area as an ASLR-bypassing
2350bd49e16eSAndy Lutomirski		  buffer.
23513dc33bd3SKees Cook
23523dc33bd3SKees Cook	config LEGACY_VSYSCALL_NONE
23533dc33bd3SKees Cook		bool "None"
23543dc33bd3SKees Cook		help
23553dc33bd3SKees Cook		  There will be no vsyscall mapping at all. This will
23563dc33bd3SKees Cook		  eliminate any risk of ASLR bypass due to the vsyscall
23573dc33bd3SKees Cook		  fixed address mapping. Attempts to use the vsyscalls
23583dc33bd3SKees Cook		  will be reported to dmesg, so that either old or
23593dc33bd3SKees Cook		  malicious userspace programs can be identified.
23603dc33bd3SKees Cook
23613dc33bd3SKees Cookendchoice
23623dc33bd3SKees Cook
2363516cbf37STim Birdconfig CMDLINE_BOOL
2364516cbf37STim Bird	bool "Built-in kernel command line"
2365a7f7f624SMasahiro Yamada	help
2366516cbf37STim Bird	  Allow for specifying boot arguments to the kernel at
2367516cbf37STim Bird	  build time.  On some systems (e.g. embedded ones), it is
2368516cbf37STim Bird	  necessary or convenient to provide some or all of the
2369516cbf37STim Bird	  kernel boot arguments with the kernel itself (that is,
2370516cbf37STim Bird	  to not rely on the boot loader to provide them.)
2371516cbf37STim Bird
2372516cbf37STim Bird	  To compile command line arguments into the kernel,
2373516cbf37STim Bird	  set this option to 'Y', then fill in the
237469711ca1SSébastien Hinderer	  boot arguments in CONFIG_CMDLINE.
2375516cbf37STim Bird
2376516cbf37STim Bird	  Systems with fully functional boot loaders (i.e. non-embedded)
2377516cbf37STim Bird	  should leave this option set to 'N'.
2378516cbf37STim Bird
2379516cbf37STim Birdconfig CMDLINE
2380516cbf37STim Bird	string "Built-in kernel command string"
2381516cbf37STim Bird	depends on CMDLINE_BOOL
2382516cbf37STim Bird	default ""
2383a7f7f624SMasahiro Yamada	help
2384516cbf37STim Bird	  Enter arguments here that should be compiled into the kernel
2385516cbf37STim Bird	  image and used at boot time.  If the boot loader provides a
2386516cbf37STim Bird	  command line at boot time, it is appended to this string to
2387516cbf37STim Bird	  form the full kernel command line, when the system boots.
2388516cbf37STim Bird
2389516cbf37STim Bird	  However, you can use the CONFIG_CMDLINE_OVERRIDE option to
2390516cbf37STim Bird	  change this behavior.
2391516cbf37STim Bird
2392516cbf37STim Bird	  In most cases, the command line (whether built-in or provided
2393516cbf37STim Bird	  by the boot loader) should specify the device for the root
2394516cbf37STim Bird	  file system.
2395516cbf37STim Bird
2396516cbf37STim Birdconfig CMDLINE_OVERRIDE
2397516cbf37STim Bird	bool "Built-in command line overrides boot loader arguments"
2398645e6466SAnders Roxell	depends on CMDLINE_BOOL && CMDLINE != ""
2399a7f7f624SMasahiro Yamada	help
2400516cbf37STim Bird	  Set this option to 'Y' to have the kernel ignore the boot loader
2401516cbf37STim Bird	  command line, and use ONLY the built-in command line.
2402516cbf37STim Bird
2403516cbf37STim Bird	  This is used to work around broken boot loaders.  This should
2404516cbf37STim Bird	  be set to 'N' under normal conditions.
2405516cbf37STim Bird
2406a5b9e5a2SAndy Lutomirskiconfig MODIFY_LDT_SYSCALL
2407a5b9e5a2SAndy Lutomirski	bool "Enable the LDT (local descriptor table)" if EXPERT
2408a5b9e5a2SAndy Lutomirski	default y
2409a7f7f624SMasahiro Yamada	help
2410a5b9e5a2SAndy Lutomirski	  Linux can allow user programs to install a per-process x86
2411a5b9e5a2SAndy Lutomirski	  Local Descriptor Table (LDT) using the modify_ldt(2) system
2412a5b9e5a2SAndy Lutomirski	  call.  This is required to run 16-bit or segmented code such as
2413a5b9e5a2SAndy Lutomirski	  DOSEMU or some Wine programs.  It is also used by some very old
2414a5b9e5a2SAndy Lutomirski	  threading libraries.
2415a5b9e5a2SAndy Lutomirski
2416a5b9e5a2SAndy Lutomirski	  Enabling this feature adds a small amount of overhead to
2417a5b9e5a2SAndy Lutomirski	  context switches and increases the low-level kernel attack
2418a5b9e5a2SAndy Lutomirski	  surface.  Disabling it removes the modify_ldt(2) system call.
2419a5b9e5a2SAndy Lutomirski
2420a5b9e5a2SAndy Lutomirski	  Saying 'N' here may make sense for embedded or server kernels.
2421a5b9e5a2SAndy Lutomirski
2422b700e7f0SSeth Jenningssource "kernel/livepatch/Kconfig"
2423b700e7f0SSeth Jennings
2424506f1d07SSam Ravnborgendmenu
2425506f1d07SSam Ravnborg
24263072e413SMichal Hockoconfig ARCH_HAS_ADD_PAGES
24273072e413SMichal Hocko	def_bool y
24283072e413SMichal Hocko	depends on X86_64 && ARCH_ENABLE_MEMORY_HOTPLUG
24293072e413SMichal Hocko
2430506f1d07SSam Ravnborgconfig ARCH_ENABLE_MEMORY_HOTPLUG
2431506f1d07SSam Ravnborg	def_bool y
2432506f1d07SSam Ravnborg	depends on X86_64 || (X86_32 && HIGHMEM)
2433506f1d07SSam Ravnborg
243435551053SGary Hadeconfig ARCH_ENABLE_MEMORY_HOTREMOVE
243535551053SGary Hade	def_bool y
243635551053SGary Hade	depends on MEMORY_HOTPLUG
243735551053SGary Hade
2438e534c7c5SLee Schermerhornconfig USE_PERCPU_NUMA_NODE_ID
2439645a7919STejun Heo	def_bool y
2440e534c7c5SLee Schermerhorn	depends on NUMA
2441e534c7c5SLee Schermerhorn
24429491846fSKirill A. Shutemovconfig ARCH_ENABLE_SPLIT_PMD_PTLOCK
24439491846fSKirill A. Shutemov	def_bool y
24449491846fSKirill A. Shutemov	depends on X86_64 || X86_PAE
24459491846fSKirill A. Shutemov
2446c177c81eSNaoya Horiguchiconfig ARCH_ENABLE_HUGEPAGE_MIGRATION
2447c177c81eSNaoya Horiguchi	def_bool y
2448c177c81eSNaoya Horiguchi	depends on X86_64 && HUGETLB_PAGE && MIGRATION
2449c177c81eSNaoya Horiguchi
24509c670ea3SNaoya Horiguchiconfig ARCH_ENABLE_THP_MIGRATION
24519c670ea3SNaoya Horiguchi	def_bool y
24529c670ea3SNaoya Horiguchi	depends on X86_64 && TRANSPARENT_HUGEPAGE
24539c670ea3SNaoya Horiguchi
2454da85f865SBjorn Helgaasmenu "Power management and ACPI options"
2455e279b6c1SSam Ravnborg
2456e279b6c1SSam Ravnborgconfig ARCH_HIBERNATION_HEADER
24573c2362e6SHarvey Harrison	def_bool y
245844556530SZhimin Gu	depends on HIBERNATION
2459e279b6c1SSam Ravnborg
2460e279b6c1SSam Ravnborgsource "kernel/power/Kconfig"
2461e279b6c1SSam Ravnborg
2462e279b6c1SSam Ravnborgsource "drivers/acpi/Kconfig"
2463e279b6c1SSam Ravnborg
2464efafc8b2SFeng Tangsource "drivers/sfi/Kconfig"
2465efafc8b2SFeng Tang
2466a6b68076SAndi Kleenconfig X86_APM_BOOT
24676fc108a0SJan Beulich	def_bool y
2468282e5aabSPaul Bolle	depends on APM
2469a6b68076SAndi Kleen
2470e279b6c1SSam Ravnborgmenuconfig APM
2471e279b6c1SSam Ravnborg	tristate "APM (Advanced Power Management) BIOS support"
2472efefa6f6SIngo Molnar	depends on X86_32 && PM_SLEEP
2473a7f7f624SMasahiro Yamada	help
2474e279b6c1SSam Ravnborg	  APM is a BIOS specification for saving power using several different
2475e279b6c1SSam Ravnborg	  techniques. This is mostly useful for battery powered laptops with
2476e279b6c1SSam Ravnborg	  APM compliant BIOSes. If you say Y here, the system time will be
2477e279b6c1SSam Ravnborg	  reset after a RESUME operation, the /proc/apm device will provide
2478e279b6c1SSam Ravnborg	  battery status information, and user-space programs will receive
2479e279b6c1SSam Ravnborg	  notification of APM "events" (e.g. battery status change).
2480e279b6c1SSam Ravnborg
2481e279b6c1SSam Ravnborg	  If you select "Y" here, you can disable actual use of the APM
2482e279b6c1SSam Ravnborg	  BIOS by passing the "apm=off" option to the kernel at boot time.
2483e279b6c1SSam Ravnborg
2484e279b6c1SSam Ravnborg	  Note that the APM support is almost completely disabled for
2485e279b6c1SSam Ravnborg	  machines with more than one CPU.
2486e279b6c1SSam Ravnborg
2487e279b6c1SSam Ravnborg	  In order to use APM, you will need supporting software. For location
2488151f4e2bSMauro Carvalho Chehab	  and more information, read <file:Documentation/power/apm-acpi.rst>
24892dc98fd3SMichael Witten	  and the Battery Powered Linux mini-HOWTO, available from
2490e279b6c1SSam Ravnborg	  <http://www.tldp.org/docs.html#howto>.
2491e279b6c1SSam Ravnborg
2492e279b6c1SSam Ravnborg	  This driver does not spin down disk drives (see the hdparm(8)
2493e279b6c1SSam Ravnborg	  manpage ("man 8 hdparm") for that), and it doesn't turn off
2494e279b6c1SSam Ravnborg	  VESA-compliant "green" monitors.
2495e279b6c1SSam Ravnborg
2496e279b6c1SSam Ravnborg	  This driver does not support the TI 4000M TravelMate and the ACER
2497e279b6c1SSam Ravnborg	  486/DX4/75 because they don't have compliant BIOSes. Many "green"
2498e279b6c1SSam Ravnborg	  desktop machines also don't have compliant BIOSes, and this driver
2499e279b6c1SSam Ravnborg	  may cause those machines to panic during the boot phase.
2500e279b6c1SSam Ravnborg
2501e279b6c1SSam Ravnborg	  Generally, if you don't have a battery in your machine, there isn't
2502e279b6c1SSam Ravnborg	  much point in using this driver and you should say N. If you get
2503e279b6c1SSam Ravnborg	  random kernel OOPSes or reboots that don't seem to be related to
2504e279b6c1SSam Ravnborg	  anything, try disabling/enabling this option (or disabling/enabling
2505e279b6c1SSam Ravnborg	  APM in your BIOS).
2506e279b6c1SSam Ravnborg
2507e279b6c1SSam Ravnborg	  Some other things you should try when experiencing seemingly random,
2508e279b6c1SSam Ravnborg	  "weird" problems:
2509e279b6c1SSam Ravnborg
2510e279b6c1SSam Ravnborg	  1) make sure that you have enough swap space and that it is
2511e279b6c1SSam Ravnborg	  enabled.
2512e279b6c1SSam Ravnborg	  2) pass the "no-hlt" option to the kernel
2513e279b6c1SSam Ravnborg	  3) switch on floating point emulation in the kernel and pass
2514e279b6c1SSam Ravnborg	  the "no387" option to the kernel
2515e279b6c1SSam Ravnborg	  4) pass the "floppy=nodma" option to the kernel
2516e279b6c1SSam Ravnborg	  5) pass the "mem=4M" option to the kernel (thereby disabling
2517e279b6c1SSam Ravnborg	  all but the first 4 MB of RAM)
2518e279b6c1SSam Ravnborg	  6) make sure that the CPU is not over clocked.
2519e279b6c1SSam Ravnborg	  7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/>
2520e279b6c1SSam Ravnborg	  8) disable the cache from your BIOS settings
2521e279b6c1SSam Ravnborg	  9) install a fan for the video card or exchange video RAM
2522e279b6c1SSam Ravnborg	  10) install a better fan for the CPU
2523e279b6c1SSam Ravnborg	  11) exchange RAM chips
2524e279b6c1SSam Ravnborg	  12) exchange the motherboard.
2525e279b6c1SSam Ravnborg
2526e279b6c1SSam Ravnborg	  To compile this driver as a module, choose M here: the
2527e279b6c1SSam Ravnborg	  module will be called apm.
2528e279b6c1SSam Ravnborg
2529e279b6c1SSam Ravnborgif APM
2530e279b6c1SSam Ravnborg
2531e279b6c1SSam Ravnborgconfig APM_IGNORE_USER_SUSPEND
2532e279b6c1SSam Ravnborg	bool "Ignore USER SUSPEND"
2533a7f7f624SMasahiro Yamada	help
2534e279b6c1SSam Ravnborg	  This option will ignore USER SUSPEND requests. On machines with a
2535e279b6c1SSam Ravnborg	  compliant APM BIOS, you want to say N. However, on the NEC Versa M
2536e279b6c1SSam Ravnborg	  series notebooks, it is necessary to say Y because of a BIOS bug.
2537e279b6c1SSam Ravnborg
2538e279b6c1SSam Ravnborgconfig APM_DO_ENABLE
2539e279b6c1SSam Ravnborg	bool "Enable PM at boot time"
2540a7f7f624SMasahiro Yamada	help
2541e279b6c1SSam Ravnborg	  Enable APM features at boot time. From page 36 of the APM BIOS
2542e279b6c1SSam Ravnborg	  specification: "When disabled, the APM BIOS does not automatically
2543e279b6c1SSam Ravnborg	  power manage devices, enter the Standby State, enter the Suspend
2544e279b6c1SSam Ravnborg	  State, or take power saving steps in response to CPU Idle calls."
2545e279b6c1SSam Ravnborg	  This driver will make CPU Idle calls when Linux is idle (unless this
2546e279b6c1SSam Ravnborg	  feature is turned off -- see "Do CPU IDLE calls", below). This
2547e279b6c1SSam Ravnborg	  should always save battery power, but more complicated APM features
2548e279b6c1SSam Ravnborg	  will be dependent on your BIOS implementation. You may need to turn
2549e279b6c1SSam Ravnborg	  this option off if your computer hangs at boot time when using APM
2550e279b6c1SSam Ravnborg	  support, or if it beeps continuously instead of suspending. Turn
2551e279b6c1SSam Ravnborg	  this off if you have a NEC UltraLite Versa 33/C or a Toshiba
2552e279b6c1SSam Ravnborg	  T400CDT. This is off by default since most machines do fine without
2553e279b6c1SSam Ravnborg	  this feature.
2554e279b6c1SSam Ravnborg
2555e279b6c1SSam Ravnborgconfig APM_CPU_IDLE
2556dd8af076SLen Brown	depends on CPU_IDLE
2557e279b6c1SSam Ravnborg	bool "Make CPU Idle calls when idle"
2558a7f7f624SMasahiro Yamada	help
2559e279b6c1SSam Ravnborg	  Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop.
2560e279b6c1SSam Ravnborg	  On some machines, this can activate improved power savings, such as
2561e279b6c1SSam Ravnborg	  a slowed CPU clock rate, when the machine is idle. These idle calls
2562e279b6c1SSam Ravnborg	  are made after the idle loop has run for some length of time (e.g.,
2563e279b6c1SSam Ravnborg	  333 mS). On some machines, this will cause a hang at boot time or
2564e279b6c1SSam Ravnborg	  whenever the CPU becomes idle. (On machines with more than one CPU,
2565e279b6c1SSam Ravnborg	  this option does nothing.)
2566e279b6c1SSam Ravnborg
2567e279b6c1SSam Ravnborgconfig APM_DISPLAY_BLANK
2568e279b6c1SSam Ravnborg	bool "Enable console blanking using APM"
2569a7f7f624SMasahiro Yamada	help
2570e279b6c1SSam Ravnborg	  Enable console blanking using the APM. Some laptops can use this to
2571e279b6c1SSam Ravnborg	  turn off the LCD backlight when the screen blanker of the Linux
2572e279b6c1SSam Ravnborg	  virtual console blanks the screen. Note that this is only used by
2573e279b6c1SSam Ravnborg	  the virtual console screen blanker, and won't turn off the backlight
2574e279b6c1SSam Ravnborg	  when using the X Window system. This also doesn't have anything to
2575e279b6c1SSam Ravnborg	  do with your VESA-compliant power-saving monitor. Further, this
2576e279b6c1SSam Ravnborg	  option doesn't work for all laptops -- it might not turn off your
2577e279b6c1SSam Ravnborg	  backlight at all, or it might print a lot of errors to the console,
2578e279b6c1SSam Ravnborg	  especially if you are using gpm.
2579e279b6c1SSam Ravnborg
2580e279b6c1SSam Ravnborgconfig APM_ALLOW_INTS
2581e279b6c1SSam Ravnborg	bool "Allow interrupts during APM BIOS calls"
2582a7f7f624SMasahiro Yamada	help
2583e279b6c1SSam Ravnborg	  Normally we disable external interrupts while we are making calls to
2584e279b6c1SSam Ravnborg	  the APM BIOS as a measure to lessen the effects of a badly behaving
2585e279b6c1SSam Ravnborg	  BIOS implementation.  The BIOS should reenable interrupts if it
2586e279b6c1SSam Ravnborg	  needs to.  Unfortunately, some BIOSes do not -- especially those in
2587e279b6c1SSam Ravnborg	  many of the newer IBM Thinkpads.  If you experience hangs when you
2588e279b6c1SSam Ravnborg	  suspend, try setting this to Y.  Otherwise, say N.
2589e279b6c1SSam Ravnborg
2590e279b6c1SSam Ravnborgendif # APM
2591e279b6c1SSam Ravnborg
2592bb0a56ecSDave Jonessource "drivers/cpufreq/Kconfig"
2593e279b6c1SSam Ravnborg
2594e279b6c1SSam Ravnborgsource "drivers/cpuidle/Kconfig"
2595e279b6c1SSam Ravnborg
259627471fdbSAndy Henroidsource "drivers/idle/Kconfig"
259727471fdbSAndy Henroid
2598e279b6c1SSam Ravnborgendmenu
2599e279b6c1SSam Ravnborg
2600e279b6c1SSam Ravnborg
2601e279b6c1SSam Ravnborgmenu "Bus options (PCI etc.)"
2602e279b6c1SSam Ravnborg
2603e279b6c1SSam Ravnborgchoice
2604e279b6c1SSam Ravnborg	prompt "PCI access mode"
2605efefa6f6SIngo Molnar	depends on X86_32 && PCI
2606e279b6c1SSam Ravnborg	default PCI_GOANY
2607a7f7f624SMasahiro Yamada	help
2608e279b6c1SSam Ravnborg	  On PCI systems, the BIOS can be used to detect the PCI devices and
2609e279b6c1SSam Ravnborg	  determine their configuration. However, some old PCI motherboards
2610e279b6c1SSam Ravnborg	  have BIOS bugs and may crash if this is done. Also, some embedded
2611e279b6c1SSam Ravnborg	  PCI-based systems don't have any BIOS at all. Linux can also try to
2612e279b6c1SSam Ravnborg	  detect the PCI hardware directly without using the BIOS.
2613e279b6c1SSam Ravnborg
2614e279b6c1SSam Ravnborg	  With this option, you can specify how Linux should detect the
2615e279b6c1SSam Ravnborg	  PCI devices. If you choose "BIOS", the BIOS will be used,
2616e279b6c1SSam Ravnborg	  if you choose "Direct", the BIOS won't be used, and if you
2617e279b6c1SSam Ravnborg	  choose "MMConfig", then PCI Express MMCONFIG will be used.
2618e279b6c1SSam Ravnborg	  If you choose "Any", the kernel will try MMCONFIG, then the
2619e279b6c1SSam Ravnborg	  direct access method and falls back to the BIOS if that doesn't
2620e279b6c1SSam Ravnborg	  work. If unsure, go with the default, which is "Any".
2621e279b6c1SSam Ravnborg
2622e279b6c1SSam Ravnborgconfig PCI_GOBIOS
2623e279b6c1SSam Ravnborg	bool "BIOS"
2624e279b6c1SSam Ravnborg
2625e279b6c1SSam Ravnborgconfig PCI_GOMMCONFIG
2626e279b6c1SSam Ravnborg	bool "MMConfig"
2627e279b6c1SSam Ravnborg
2628e279b6c1SSam Ravnborgconfig PCI_GODIRECT
2629e279b6c1SSam Ravnborg	bool "Direct"
2630e279b6c1SSam Ravnborg
26313ef0e1f8SAndres Salomonconfig PCI_GOOLPC
263276fb6570SDaniel Drake	bool "OLPC XO-1"
26333ef0e1f8SAndres Salomon	depends on OLPC
26343ef0e1f8SAndres Salomon
26352bdd1b03SAndres Salomonconfig PCI_GOANY
26362bdd1b03SAndres Salomon	bool "Any"
26372bdd1b03SAndres Salomon
2638e279b6c1SSam Ravnborgendchoice
2639e279b6c1SSam Ravnborg
2640e279b6c1SSam Ravnborgconfig PCI_BIOS
26413c2362e6SHarvey Harrison	def_bool y
2642efefa6f6SIngo Molnar	depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY)
2643e279b6c1SSam Ravnborg
2644e279b6c1SSam Ravnborg# x86-64 doesn't support PCI BIOS access from long mode so always go direct.
2645e279b6c1SSam Ravnborgconfig PCI_DIRECT
26463c2362e6SHarvey Harrison	def_bool y
26470aba496fSShaohua Li	depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC || PCI_GOMMCONFIG))
2648e279b6c1SSam Ravnborg
2649e279b6c1SSam Ravnborgconfig PCI_MMCONFIG
2650b45c9f36SJan Kiszka	bool "Support mmconfig PCI config space access" if X86_64
2651b45c9f36SJan Kiszka	default y
26528364e1f8SJan Kiszka	depends on PCI && (ACPI || SFI || JAILHOUSE_GUEST)
2653b45c9f36SJan Kiszka	depends on X86_64 || (PCI_GOANY || PCI_GOMMCONFIG)
2654e279b6c1SSam Ravnborg
26553ef0e1f8SAndres Salomonconfig PCI_OLPC
26562bdd1b03SAndres Salomon	def_bool y
26572bdd1b03SAndres Salomon	depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY)
26583ef0e1f8SAndres Salomon
2659b5401a96SAlex Nixonconfig PCI_XEN
2660b5401a96SAlex Nixon	def_bool y
2661b5401a96SAlex Nixon	depends on PCI && XEN
2662b5401a96SAlex Nixon	select SWIOTLB_XEN
2663b5401a96SAlex Nixon
26648364e1f8SJan Kiszkaconfig MMCONF_FAM10H
26658364e1f8SJan Kiszka	def_bool y
26668364e1f8SJan Kiszka	depends on X86_64 && PCI_MMCONFIG && ACPI
2667e279b6c1SSam Ravnborg
26683f6ea84aSIra W. Snyderconfig PCI_CNB20LE_QUIRK
26696a108a14SDavid Rientjes	bool "Read CNB20LE Host Bridge Windows" if EXPERT
26706ea30386SKees Cook	depends on PCI
26713f6ea84aSIra W. Snyder	help
26723f6ea84aSIra W. Snyder	  Read the PCI windows out of the CNB20LE host bridge. This allows
26733f6ea84aSIra W. Snyder	  PCI hotplug to work on systems with the CNB20LE chipset which do
26743f6ea84aSIra W. Snyder	  not have ACPI.
26753f6ea84aSIra W. Snyder
267664a5fed6SBjorn Helgaas	  There's no public spec for this chipset, and this functionality
267764a5fed6SBjorn Helgaas	  is known to be incomplete.
267864a5fed6SBjorn Helgaas
267964a5fed6SBjorn Helgaas	  You should say N unless you know you need this.
268064a5fed6SBjorn Helgaas
26813a495511SWilliam Breathitt Grayconfig ISA_BUS
268217a2a129SWilliam Breathitt Gray	bool "ISA bus support on modern systems" if EXPERT
26833a495511SWilliam Breathitt Gray	help
268417a2a129SWilliam Breathitt Gray	  Expose ISA bus device drivers and options available for selection and
268517a2a129SWilliam Breathitt Gray	  configuration. Enable this option if your target machine has an ISA
268617a2a129SWilliam Breathitt Gray	  bus. ISA is an older system, displaced by PCI and newer bus
268717a2a129SWilliam Breathitt Gray	  architectures -- if your target machine is modern, it probably does
268817a2a129SWilliam Breathitt Gray	  not have an ISA bus.
26893a495511SWilliam Breathitt Gray
26903a495511SWilliam Breathitt Gray	  If unsure, say N.
26913a495511SWilliam Breathitt Gray
26921c00f016SDavid Rientjes# x86_64 have no ISA slots, but can have ISA-style DMA.
2693e279b6c1SSam Ravnborgconfig ISA_DMA_API
26941c00f016SDavid Rientjes	bool "ISA-style DMA support" if (X86_64 && EXPERT)
26951c00f016SDavid Rientjes	default y
26961c00f016SDavid Rientjes	help
26971c00f016SDavid Rientjes	  Enables ISA-style DMA support for devices requiring such controllers.
26981c00f016SDavid Rientjes	  If unsure, say Y.
2699e279b6c1SSam Ravnborg
270051e68d05SLinus Torvaldsif X86_32
270151e68d05SLinus Torvalds
2702e279b6c1SSam Ravnborgconfig ISA
2703e279b6c1SSam Ravnborg	bool "ISA support"
2704a7f7f624SMasahiro Yamada	help
2705e279b6c1SSam Ravnborg	  Find out whether you have ISA slots on your motherboard.  ISA is the
2706e279b6c1SSam Ravnborg	  name of a bus system, i.e. the way the CPU talks to the other stuff
2707e279b6c1SSam Ravnborg	  inside your box.  Other bus systems are PCI, EISA, MicroChannel
2708e279b6c1SSam Ravnborg	  (MCA) or VESA.  ISA is an older system, now being displaced by PCI;
2709e279b6c1SSam Ravnborg	  newer boards don't support it.  If you have ISA, say Y, otherwise N.
2710e279b6c1SSam Ravnborg
2711e279b6c1SSam Ravnborgconfig SCx200
2712e279b6c1SSam Ravnborg	tristate "NatSemi SCx200 support"
2713a7f7f624SMasahiro Yamada	help
2714e279b6c1SSam Ravnborg	  This provides basic support for National Semiconductor's
2715e279b6c1SSam Ravnborg	  (now AMD's) Geode processors.  The driver probes for the
2716e279b6c1SSam Ravnborg	  PCI-IDs of several on-chip devices, so its a good dependency
2717e279b6c1SSam Ravnborg	  for other scx200_* drivers.
2718e279b6c1SSam Ravnborg
2719e279b6c1SSam Ravnborg	  If compiled as a module, the driver is named scx200.
2720e279b6c1SSam Ravnborg
2721e279b6c1SSam Ravnborgconfig SCx200HR_TIMER
2722e279b6c1SSam Ravnborg	tristate "NatSemi SCx200 27MHz High-Resolution Timer Support"
2723592913ecSJohn Stultz	depends on SCx200
2724e279b6c1SSam Ravnborg	default y
2725a7f7f624SMasahiro Yamada	help
2726e279b6c1SSam Ravnborg	  This driver provides a clocksource built upon the on-chip
2727e279b6c1SSam Ravnborg	  27MHz high-resolution timer.  Its also a workaround for
2728e279b6c1SSam Ravnborg	  NSC Geode SC-1100's buggy TSC, which loses time when the
2729e279b6c1SSam Ravnborg	  processor goes idle (as is done by the scheduler).  The
2730e279b6c1SSam Ravnborg	  other workaround is idle=poll boot option.
2731e279b6c1SSam Ravnborg
27323ef0e1f8SAndres Salomonconfig OLPC
27333ef0e1f8SAndres Salomon	bool "One Laptop Per Child support"
273454008979SThomas Gleixner	depends on !X86_PAE
27353c554946SAndres Salomon	select GPIOLIB
2736dc3119e7SThomas Gleixner	select OF
273745bb1674SDaniel Drake	select OF_PROMTREE
2738b4e51854SGrant Likely	select IRQ_DOMAIN
27390c3d931bSLubomir Rintel	select OLPC_EC
2740a7f7f624SMasahiro Yamada	help
27413ef0e1f8SAndres Salomon	  Add support for detecting the unique features of the OLPC
27423ef0e1f8SAndres Salomon	  XO hardware.
27433ef0e1f8SAndres Salomon
2744a3128588SDaniel Drakeconfig OLPC_XO1_PM
2745a3128588SDaniel Drake	bool "OLPC XO-1 Power Management"
2746fa112cf1SBorislav Petkov	depends on OLPC && MFD_CS5535=y && PM_SLEEP
2747a7f7f624SMasahiro Yamada	help
274897c4cb71SDaniel Drake	  Add support for poweroff and suspend of the OLPC XO-1 laptop.
2749bf1ebf00SDaniel Drake
2750cfee9597SDaniel Drakeconfig OLPC_XO1_RTC
2751cfee9597SDaniel Drake	bool "OLPC XO-1 Real Time Clock"
2752cfee9597SDaniel Drake	depends on OLPC_XO1_PM && RTC_DRV_CMOS
2753a7f7f624SMasahiro Yamada	help
2754cfee9597SDaniel Drake	  Add support for the XO-1 real time clock, which can be used as a
2755cfee9597SDaniel Drake	  programmable wakeup source.
2756cfee9597SDaniel Drake
27577feda8e9SDaniel Drakeconfig OLPC_XO1_SCI
27587feda8e9SDaniel Drake	bool "OLPC XO-1 SCI extras"
275992e830f2SArnd Bergmann	depends on OLPC && OLPC_XO1_PM && GPIO_CS5535=y
2760ed8e47feSRandy Dunlap	depends on INPUT=y
2761d8d01a63SDaniel Drake	select POWER_SUPPLY
2762a7f7f624SMasahiro Yamada	help
27637feda8e9SDaniel Drake	  Add support for SCI-based features of the OLPC XO-1 laptop:
27647bc74b3dSDaniel Drake	   - EC-driven system wakeups
27657feda8e9SDaniel Drake	   - Power button
27667bc74b3dSDaniel Drake	   - Ebook switch
27672cf2baeaSDaniel Drake	   - Lid switch
2768e1040ac6SDaniel Drake	   - AC adapter status updates
2769e1040ac6SDaniel Drake	   - Battery status updates
27707feda8e9SDaniel Drake
2771a0f30f59SDaniel Drakeconfig OLPC_XO15_SCI
2772a0f30f59SDaniel Drake	bool "OLPC XO-1.5 SCI extras"
2773d8d01a63SDaniel Drake	depends on OLPC && ACPI
2774d8d01a63SDaniel Drake	select POWER_SUPPLY
2775a7f7f624SMasahiro Yamada	help
2776a0f30f59SDaniel Drake	  Add support for SCI-based features of the OLPC XO-1.5 laptop:
2777a0f30f59SDaniel Drake	   - EC-driven system wakeups
2778a0f30f59SDaniel Drake	   - AC adapter status updates
2779a0f30f59SDaniel Drake	   - Battery status updates
2780e279b6c1SSam Ravnborg
2781d4f3e350SEd Wildgooseconfig ALIX
2782d4f3e350SEd Wildgoose	bool "PCEngines ALIX System Support (LED setup)"
2783d4f3e350SEd Wildgoose	select GPIOLIB
2784a7f7f624SMasahiro Yamada	help
2785d4f3e350SEd Wildgoose	  This option enables system support for the PCEngines ALIX.
2786d4f3e350SEd Wildgoose	  At present this just sets up LEDs for GPIO control on
2787d4f3e350SEd Wildgoose	  ALIX2/3/6 boards.  However, other system specific setup should
2788d4f3e350SEd Wildgoose	  get added here.
2789d4f3e350SEd Wildgoose
2790d4f3e350SEd Wildgoose	  Note: You must still enable the drivers for GPIO and LED support
2791d4f3e350SEd Wildgoose	  (GPIO_CS5535 & LEDS_GPIO) to actually use the LEDs
2792d4f3e350SEd Wildgoose
2793d4f3e350SEd Wildgoose	  Note: You have to set alix.force=1 for boards with Award BIOS.
2794d4f3e350SEd Wildgoose
2795da4e3302SPhilip Prindevilleconfig NET5501
2796da4e3302SPhilip Prindeville	bool "Soekris Engineering net5501 System Support (LEDS, GPIO, etc)"
2797da4e3302SPhilip Prindeville	select GPIOLIB
2798a7f7f624SMasahiro Yamada	help
2799da4e3302SPhilip Prindeville	  This option enables system support for the Soekris Engineering net5501.
2800da4e3302SPhilip Prindeville
28013197059aSPhilip A. Prindevilleconfig GEOS
28023197059aSPhilip A. Prindeville	bool "Traverse Technologies GEOS System Support (LEDS, GPIO, etc)"
28033197059aSPhilip A. Prindeville	select GPIOLIB
28043197059aSPhilip A. Prindeville	depends on DMI
2805a7f7f624SMasahiro Yamada	help
28063197059aSPhilip A. Prindeville	  This option enables system support for the Traverse Technologies GEOS.
28073197059aSPhilip A. Prindeville
28087d029125SVivien Didelotconfig TS5500
28097d029125SVivien Didelot	bool "Technologic Systems TS-5500 platform support"
28107d029125SVivien Didelot	depends on MELAN
28117d029125SVivien Didelot	select CHECK_SIGNATURE
28127d029125SVivien Didelot	select NEW_LEDS
28137d029125SVivien Didelot	select LEDS_CLASS
2814a7f7f624SMasahiro Yamada	help
28157d029125SVivien Didelot	  This option enables system support for the Technologic Systems TS-5500.
28167d029125SVivien Didelot
2817e279b6c1SSam Ravnborgendif # X86_32
2818e279b6c1SSam Ravnborg
281923ac4ae8SAndreas Herrmannconfig AMD_NB
2820e279b6c1SSam Ravnborg	def_bool y
28210e152cd7SBorislav Petkov	depends on CPU_SUP_AMD && PCI
2822e279b6c1SSam Ravnborg
2823e3263ab3SDavid Herrmannconfig X86_SYSFB
2824e3263ab3SDavid Herrmann	bool "Mark VGA/VBE/EFI FB as generic system framebuffer"
2825e3263ab3SDavid Herrmann	help
2826e3263ab3SDavid Herrmann	  Firmwares often provide initial graphics framebuffers so the BIOS,
2827e3263ab3SDavid Herrmann	  bootloader or kernel can show basic video-output during boot for
2828e3263ab3SDavid Herrmann	  user-guidance and debugging. Historically, x86 used the VESA BIOS
2829e3263ab3SDavid Herrmann	  Extensions and EFI-framebuffers for this, which are mostly limited
2830e3263ab3SDavid Herrmann	  to x86.
2831e3263ab3SDavid Herrmann	  This option, if enabled, marks VGA/VBE/EFI framebuffers as generic
2832e3263ab3SDavid Herrmann	  framebuffers so the new generic system-framebuffer drivers can be
2833e3263ab3SDavid Herrmann	  used on x86. If the framebuffer is not compatible with the generic
2834e3a5dc08SNikolas Nyby	  modes, it is advertised as fallback platform framebuffer so legacy
2835e3263ab3SDavid Herrmann	  drivers like efifb, vesafb and uvesafb can pick it up.
2836e3263ab3SDavid Herrmann	  If this option is not selected, all system framebuffers are always
2837e3263ab3SDavid Herrmann	  marked as fallback platform framebuffers as usual.
2838e3263ab3SDavid Herrmann
2839e3263ab3SDavid Herrmann	  Note: Legacy fbdev drivers, including vesafb, efifb, uvesafb, will
2840e3263ab3SDavid Herrmann	  not be able to pick up generic system framebuffers if this option
2841e3263ab3SDavid Herrmann	  is selected. You are highly encouraged to enable simplefb as
2842e3263ab3SDavid Herrmann	  replacement if you select this option. simplefb can correctly deal
2843e3263ab3SDavid Herrmann	  with generic system framebuffers. But you should still keep vesafb
2844e3263ab3SDavid Herrmann	  and others enabled as fallback if a system framebuffer is
2845e3263ab3SDavid Herrmann	  incompatible with simplefb.
2846e3263ab3SDavid Herrmann
2847e3263ab3SDavid Herrmann	  If unsure, say Y.
2848e3263ab3SDavid Herrmann
2849e279b6c1SSam Ravnborgendmenu
2850e279b6c1SSam Ravnborg
2851e279b6c1SSam Ravnborg
28521572497cSChristoph Hellwigmenu "Binary Emulations"
2853e279b6c1SSam Ravnborg
2854e279b6c1SSam Ravnborgconfig IA32_EMULATION
2855e279b6c1SSam Ravnborg	bool "IA32 Emulation"
2856e279b6c1SSam Ravnborg	depends on X86_64
285739f88911SIngo Molnar	select ARCH_WANT_OLD_COMPAT_IPC
2858d1603990SRandy Dunlap	select BINFMT_ELF
2859a97f52e6SRoland McGrath	select COMPAT_BINFMT_ELF
286039f88911SIngo Molnar	select COMPAT_OLD_SIGACTION
2861a7f7f624SMasahiro Yamada	help
28625fd92e65SH. J. Lu	  Include code to run legacy 32-bit programs under a
28635fd92e65SH. J. Lu	  64-bit kernel. You should likely turn this on, unless you're
28645fd92e65SH. J. Lu	  100% sure that you don't have any 32-bit programs left.
2865e279b6c1SSam Ravnborg
2866e279b6c1SSam Ravnborgconfig IA32_AOUT
2867e279b6c1SSam Ravnborg	tristate "IA32 a.out support"
28686b213e1bSDavid Woodhouse	depends on IA32_EMULATION
2869eac61655SBorislav Petkov	depends on BROKEN
2870a7f7f624SMasahiro Yamada	help
2871e279b6c1SSam Ravnborg	  Support old a.out binaries in the 32bit emulation.
2872e279b6c1SSam Ravnborg
28730bf62763SH. Peter Anvinconfig X86_X32
28746ea30386SKees Cook	bool "x32 ABI for 64-bit mode"
28759b54050bSBrian Gerst	depends on X86_64
2876a7f7f624SMasahiro Yamada	help
28775fd92e65SH. J. Lu	  Include code to run binaries for the x32 native 32-bit ABI
28785fd92e65SH. J. Lu	  for 64-bit processors.  An x32 process gets access to the
28795fd92e65SH. J. Lu	  full 64-bit register file and wide data path while leaving
28805fd92e65SH. J. Lu	  pointers at 32 bits for smaller memory footprint.
28815fd92e65SH. J. Lu
28825fd92e65SH. J. Lu	  You will need a recent binutils (2.22 or later) with
28835fd92e65SH. J. Lu	  elf32_x86_64 support enabled to compile a kernel with this
28845fd92e65SH. J. Lu	  option set.
28855fd92e65SH. J. Lu
2886953fee1dSIngo Molnarconfig COMPAT_32
2887953fee1dSIngo Molnar	def_bool y
2888953fee1dSIngo Molnar	depends on IA32_EMULATION || X86_32
2889953fee1dSIngo Molnar	select HAVE_UID16
2890953fee1dSIngo Molnar	select OLD_SIGSUSPEND3
2891953fee1dSIngo Molnar
2892e279b6c1SSam Ravnborgconfig COMPAT
28933c2362e6SHarvey Harrison	def_bool y
28940bf62763SH. Peter Anvin	depends on IA32_EMULATION || X86_X32
2895e279b6c1SSam Ravnborg
28963120e25eSJan Beulichif COMPAT
2897e279b6c1SSam Ravnborgconfig COMPAT_FOR_U64_ALIGNMENT
28983120e25eSJan Beulich	def_bool y
2899e279b6c1SSam Ravnborg
2900e279b6c1SSam Ravnborgconfig SYSVIPC_COMPAT
29013c2362e6SHarvey Harrison	def_bool y
29023120e25eSJan Beulich	depends on SYSVIPC
29033120e25eSJan Beulichendif
2904ee009e4aSDavid Howells
2905e279b6c1SSam Ravnborgendmenu
2906e279b6c1SSam Ravnborg
2907e279b6c1SSam Ravnborg
2908e5beae16SKeith Packardconfig HAVE_ATOMIC_IOMAP
2909e5beae16SKeith Packard	def_bool y
2910e5beae16SKeith Packard	depends on X86_32
2911e5beae16SKeith Packard
2912e279b6c1SSam Ravnborgsource "drivers/firmware/Kconfig"
2913e279b6c1SSam Ravnborg
2914edf88417SAvi Kivitysource "arch/x86/kvm/Kconfig"
29155e8ebd84SJason A. Donenfeld
29165e8ebd84SJason A. Donenfeldsource "arch/x86/Kconfig.assembler"
2917