xref: /linux/arch/x86/Kconfig (revision cd1a41ceba8a4caef4d18a3a14d6d0f8c656efe4)
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
17157e118bSThomas Gleixner	select GENERIC_VDSO_32
18117ed454SThomas Gleixner	select HAVE_DEBUG_STACKOVERFLOW
19157e118bSThomas Gleixner	select KMAP_LOCAL
20341c787eSIngo Molnar	select MODULES_USE_ELF_REL
21341c787eSIngo Molnar	select OLD_SIGACTION
222ca408d9SBrian Gerst	select ARCH_SPLIT_ARG64
23daa93fabSSam Ravnborg
24daa93fabSSam Ravnborgconfig X86_64
253120e25eSJan Beulich	def_bool y
263120e25eSJan Beulich	depends on 64BIT
27d94e0685SIngo Molnar	# Options that are inherently 64-bit kernel only:
284eb0716eSAlexandre Ghiti	select ARCH_HAS_GIGANTIC_PAGE
29c12d3362SArd Biesheuvel	select ARCH_SUPPORTS_INT128 if CC_HAS_INT128
30d94e0685SIngo Molnar	select ARCH_USE_CMPXCHG_LOCKREF
31d94e0685SIngo Molnar	select HAVE_ARCH_SOFT_DIRTY
32d94e0685SIngo Molnar	select MODULES_USE_ELF_RELA
33f616ab59SChristoph Hellwig	select NEED_DMA_MAP_STATE
3409230cbcSChristoph Hellwig	select SWIOTLB
351032c0baSSam Ravnborg
36518049d9SSteven Rostedt (VMware)config FORCE_DYNAMIC_FTRACE
37518049d9SSteven Rostedt (VMware)	def_bool y
38518049d9SSteven Rostedt (VMware)	depends on X86_32
39518049d9SSteven Rostedt (VMware)	depends on FUNCTION_TRACER
40518049d9SSteven Rostedt (VMware)	select DYNAMIC_FTRACE
41518049d9SSteven Rostedt (VMware)	help
42518049d9SSteven Rostedt (VMware)	 We keep the static function tracing (!DYNAMIC_FTRACE) around
43518049d9SSteven Rostedt (VMware)	 in order to test the non static function tracing in the
44518049d9SSteven Rostedt (VMware)	 generic code, as other architectures still use it. But we
45518049d9SSteven Rostedt (VMware)	 only need to keep it around for x86_64. No need to keep it
46518049d9SSteven Rostedt (VMware)	 for x86_32. For x86_32, force DYNAMIC_FTRACE.
47d94e0685SIngo Molnar#
48d94e0685SIngo Molnar# Arch settings
49d94e0685SIngo Molnar#
50d94e0685SIngo Molnar# ( Note that options that are marked 'if X86_64' could in principle be
51d94e0685SIngo Molnar#   ported to 32-bit as well. )
52d94e0685SIngo Molnar#
538d5fffb9SSam Ravnborgconfig X86
543c2362e6SHarvey Harrison	def_bool y
55c763ea26SIngo Molnar	#
56c763ea26SIngo Molnar	# Note: keep this list sorted alphabetically
57c763ea26SIngo Molnar	#
586471b825SIngo Molnar	select ACPI_LEGACY_TABLES_LOOKUP	if ACPI
596e0a0ea1SGraeme Gregory	select ACPI_SYSTEM_POWER_STATES_SUPPORT	if ACPI
60942fa985SYury Norov	select ARCH_32BIT_OFF_T			if X86_32
612a21ad57SThomas Gleixner	select ARCH_CLOCKSOURCE_INIT
6291dda51aSAleksey Makarov	select ARCH_HAS_ACPI_TABLE_UPGRADE	if ACPI
63fa5b6ec9SLaura Abbott	select ARCH_HAS_DEBUG_VIRTUAL
64399145f9SAnshuman Khandual	select ARCH_HAS_DEBUG_VM_PGTABLE	if !X86_PAE
6521266be9SDan Williams	select ARCH_HAS_DEVMEM_IS_ALLOWED
66b1a57bbfSDouglas Anderson	select ARCH_HAS_EARLY_DEBUG		if KGDB
676471b825SIngo Molnar	select ARCH_HAS_ELF_RANDOMIZE
6872d93104SLinus Torvalds	select ARCH_HAS_FAST_MULTIPLIER
69316d097cSDave Hansen	select ARCH_HAS_FILTER_PGPROT
706974f0c4SDaniel Micay	select ARCH_HAS_FORTIFY_SOURCE
71957e3facSRiku Voipio	select ARCH_HAS_GCOV_PROFILE_ALL
720f1441b4SPeter Zijlstra	select ARCH_HAS_KCOV			if X86_64 && STACK_VALIDATION
730c9c1d56SThiago Jung Bauermann	select ARCH_HAS_MEM_ENCRYPT
7410bcc80eSMathieu Desnoyers	select ARCH_HAS_MEMBARRIER_SYNC_CORE
750ebeea8cSDaniel Borkmann	select ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE
76c763ea26SIngo Molnar	select ARCH_HAS_PMEM_API		if X86_64
7717596731SRobin Murphy	select ARCH_HAS_PTE_DEVMAP		if X86_64
783010a5eaSLaurent Dufour	select ARCH_HAS_PTE_SPECIAL
790aed55afSDan Williams	select ARCH_HAS_UACCESS_FLUSHCACHE	if X86_64
80ec6347bbSDan Williams	select ARCH_HAS_COPY_MC			if X86_64
81d2852a22SDaniel Borkmann	select ARCH_HAS_SET_MEMORY
82d253ca0cSRick Edgecombe	select ARCH_HAS_SET_DIRECT_MAP
83ad21fc4fSLaura Abbott	select ARCH_HAS_STRICT_KERNEL_RWX
84ad21fc4fSLaura Abbott	select ARCH_HAS_STRICT_MODULE_RWX
85ac1ab12aSMathieu Desnoyers	select ARCH_HAS_SYNC_CORE_BEFORE_USERMODE
8625c619e5SBrian Gerst	select ARCH_HAS_SYSCALL_WRAPPER
87c6d30853SAndrey Ryabinin	select ARCH_HAS_UBSAN_SANITIZE_ALL
887e01ccb4SZong Li	select ARCH_HAS_DEBUG_WX
896471b825SIngo Molnar	select ARCH_HAVE_NMI_SAFE_CMPXCHG
906471b825SIngo Molnar	select ARCH_MIGHT_HAVE_ACPI_PDC		if ACPI
9177fbbc81SMark Salter	select ARCH_MIGHT_HAVE_PC_PARPORT
925e2c18c0SMark Salter	select ARCH_MIGHT_HAVE_PC_SERIO
933599fe12SThomas Gleixner	select ARCH_STACKWALK
942c870e61SArnd Bergmann	select ARCH_SUPPORTS_ACPI
956471b825SIngo Molnar	select ARCH_SUPPORTS_ATOMIC_RMW
965d6ad668SMike Rapoport	select ARCH_SUPPORTS_DEBUG_PAGEALLOC
976471b825SIngo Molnar	select ARCH_SUPPORTS_NUMA_BALANCING	if X86_64
9814df3267SThomas Gleixner	select ARCH_SUPPORTS_KMAP_LOCAL_FORCE_MAP	if NR_CPUS <= 4096
996471b825SIngo Molnar	select ARCH_USE_BUILTIN_BSWAP
1006471b825SIngo Molnar	select ARCH_USE_QUEUED_RWLOCKS
1016471b825SIngo Molnar	select ARCH_USE_QUEUED_SPINLOCKS
1022ce0d7f9SMark Brown	select ARCH_USE_SYM_ANNOTATIONS
103ce4a4e56SAndy Lutomirski	select ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH
10481c22041SDaniel Borkmann	select ARCH_WANT_DEFAULT_BPF_JIT	if X86_64
105c763ea26SIngo Molnar	select ARCH_WANTS_DYNAMIC_TASK_STRUCT
1063876d4a3SAlexandre Ghiti	select ARCH_WANT_HUGE_PMD_SHARE
10759612b24SNathan Chancellor	select ARCH_WANT_LD_ORPHAN_WARN
10838d8b4e6SHuang Ying	select ARCH_WANTS_THP_SWAP		if X86_64
10910916706SShile Zhang	select BUILDTIME_TABLE_SORT
1106471b825SIngo Molnar	select CLKEVT_I8253
1116471b825SIngo Molnar	select CLOCKSOURCE_VALIDATE_LAST_CYCLE
1126471b825SIngo Molnar	select CLOCKSOURCE_WATCHDOG
1136471b825SIngo Molnar	select DCACHE_WORD_ACCESS
11445471cd9SLinus Torvalds	select EDAC_ATOMIC_SCRUB
11545471cd9SLinus Torvalds	select EDAC_SUPPORT
1166471b825SIngo Molnar	select GENERIC_CLOCKEVENTS_BROADCAST	if X86_64 || (X86_32 && X86_LOCAL_APIC)
1176471b825SIngo Molnar	select GENERIC_CLOCKEVENTS_MIN_ADJUST
1186471b825SIngo Molnar	select GENERIC_CMOS_UPDATE
1196471b825SIngo Molnar	select GENERIC_CPU_AUTOPROBE
12061dc0f55SThomas Gleixner	select GENERIC_CPU_VULNERABILITIES
1216471b825SIngo Molnar	select GENERIC_EARLY_IOREMAP
12227d6b4d1SThomas Gleixner	select GENERIC_ENTRY
1236471b825SIngo Molnar	select GENERIC_FIND_FIRST_BIT
1246471b825SIngo Molnar	select GENERIC_IOMAP
125c7d6c9ddSThomas Gleixner	select GENERIC_IRQ_EFFECTIVE_AFF_MASK	if SMP
1260fa115daSThomas Gleixner	select GENERIC_IRQ_MATRIX_ALLOCATOR	if X86_LOCAL_APIC
127ad7a929fSThomas Gleixner	select GENERIC_IRQ_MIGRATION		if SMP
1286471b825SIngo Molnar	select GENERIC_IRQ_PROBE
129c201c917SThomas Gleixner	select GENERIC_IRQ_RESERVATION_MODE
1306471b825SIngo Molnar	select GENERIC_IRQ_SHOW
1316471b825SIngo Molnar	select GENERIC_PENDING_IRQ		if SMP
1322ae27137SSteven Price	select GENERIC_PTDUMP
1336471b825SIngo Molnar	select GENERIC_SMP_IDLE_THREAD
1346471b825SIngo Molnar	select GENERIC_STRNCPY_FROM_USER
1356471b825SIngo Molnar	select GENERIC_STRNLEN_USER
1366471b825SIngo Molnar	select GENERIC_TIME_VSYSCALL
1377ac87074SVincenzo Frascino	select GENERIC_GETTIMEOFDAY
138550a77a7SDmitry Safonov	select GENERIC_VDSO_TIME_NS
13939656e83SChristoph Hellwig	select GUP_GET_PTE_LOW_HIGH		if X86_PAE
14017e5888eSHans de Goede	select HARDIRQS_SW_RESEND
1417edaeb68SThomas Gleixner	select HARDLOCKUP_CHECK_TIMESTAMP	if X86_64
1426471b825SIngo Molnar	select HAVE_ACPI_APEI			if ACPI
1436471b825SIngo Molnar	select HAVE_ACPI_APEI_NMI		if ACPI
1446471b825SIngo Molnar	select HAVE_ALIGNED_STRUCT_PAGE		if SLUB
1456471b825SIngo Molnar	select HAVE_ARCH_AUDITSYSCALL
1466471b825SIngo Molnar	select HAVE_ARCH_HUGE_VMAP		if X86_64 || X86_PAE
1476471b825SIngo Molnar	select HAVE_ARCH_JUMP_LABEL
148b34006c4SArd Biesheuvel	select HAVE_ARCH_JUMP_LABEL_RELATIVE
149d17a1d97SAndrey Ryabinin	select HAVE_ARCH_KASAN			if X86_64
1500609ae01SDaniel Axtens	select HAVE_ARCH_KASAN_VMALLOC		if X86_64
1516471b825SIngo Molnar	select HAVE_ARCH_KGDB
1529e08f57dSDaniel Cashman	select HAVE_ARCH_MMAP_RND_BITS		if MMU
1539e08f57dSDaniel Cashman	select HAVE_ARCH_MMAP_RND_COMPAT_BITS	if MMU && COMPAT
1541b028f78SDmitry Safonov	select HAVE_ARCH_COMPAT_MMAP_BASES	if MMU && COMPAT
155271ca788SArd Biesheuvel	select HAVE_ARCH_PREL32_RELOCATIONS
1566471b825SIngo Molnar	select HAVE_ARCH_SECCOMP_FILTER
157f7d83c1cSKees Cook	select HAVE_ARCH_THREAD_STRUCT_WHITELIST
158afaef01cSAlexander Popov	select HAVE_ARCH_STACKLEAK
1596471b825SIngo Molnar	select HAVE_ARCH_TRACEHOOK
1606471b825SIngo Molnar	select HAVE_ARCH_TRANSPARENT_HUGEPAGE
161a00cc7d9SMatthew Wilcox	select HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD if X86_64
162b64d8d1eSPeter Xu	select HAVE_ARCH_USERFAULTFD_WP         if X86_64 && USERFAULTFD
163e37e43a4SAndy Lutomirski	select HAVE_ARCH_VMAP_STACK		if X86_64
164c763ea26SIngo Molnar	select HAVE_ARCH_WITHIN_STACK_FRAMES
1652ff2b7ecSMasahiro Yamada	select HAVE_ASM_MODVERSIONS
1666471b825SIngo Molnar	select HAVE_CMPXCHG_DOUBLE
1676471b825SIngo Molnar	select HAVE_CMPXCHG_LOCAL
1686471b825SIngo Molnar	select HAVE_CONTEXT_TRACKING		if X86_64
169d1f250e2SFrederic Weisbecker	select HAVE_CONTEXT_TRACKING_OFFSTACK	if HAVE_CONTEXT_TRACKING
1706471b825SIngo Molnar	select HAVE_C_RECORDMCOUNT
1716471b825SIngo Molnar	select HAVE_DEBUG_KMEMLEAK
1729c5a3621SAkinobu Mita	select HAVE_DMA_CONTIGUOUS
173677aa9f7SSteven Rostedt	select HAVE_DYNAMIC_FTRACE
17406aeaaeaSMasami Hiramatsu	select HAVE_DYNAMIC_FTRACE_WITH_REGS
17502a474caSSteven Rostedt (VMware)	select HAVE_DYNAMIC_FTRACE_WITH_ARGS	if X86_64
176562955feSSteven Rostedt (VMware)	select HAVE_DYNAMIC_FTRACE_WITH_DIRECT_CALLS
17703f5781bSWang YanQing	select HAVE_EBPF_JIT
17858340a07SJohannes Berg	select HAVE_EFFICIENT_UNALIGNED_ACCESS
1796630a8e5SChristoph Hellwig	select HAVE_EISA
1805f56a5dfSJiri Slaby	select HAVE_EXIT_THREAD
18167a929e0SChristoph Hellwig	select HAVE_FAST_GUP
182644e0e8dSSteven Rostedt (VMware)	select HAVE_FENTRY			if X86_64 || DYNAMIC_FTRACE
1836471b825SIngo Molnar	select HAVE_FTRACE_MCOUNT_RECORD
1846471b825SIngo Molnar	select HAVE_FUNCTION_GRAPH_TRACER
1856471b825SIngo Molnar	select HAVE_FUNCTION_TRACER
1866b90bd4bSEmese Revfy	select HAVE_GCC_PLUGINS
1870067f129SK.Prasad	select HAVE_HW_BREAKPOINT
1886471b825SIngo Molnar	select HAVE_IDE
1896471b825SIngo Molnar	select HAVE_IOREMAP_PROT
190624db9eaSThomas Gleixner	select HAVE_IRQ_EXIT_ON_IRQ_STACK	if X86_64
1916471b825SIngo Molnar	select HAVE_IRQ_TIME_ACCOUNTING
1926471b825SIngo Molnar	select HAVE_KERNEL_BZIP2
1936471b825SIngo Molnar	select HAVE_KERNEL_GZIP
1946471b825SIngo Molnar	select HAVE_KERNEL_LZ4
1956471b825SIngo Molnar	select HAVE_KERNEL_LZMA
1966471b825SIngo Molnar	select HAVE_KERNEL_LZO
1976471b825SIngo Molnar	select HAVE_KERNEL_XZ
198fb46d057SNick Terrell	select HAVE_KERNEL_ZSTD
1996471b825SIngo Molnar	select HAVE_KPROBES
2006471b825SIngo Molnar	select HAVE_KPROBES_ON_FTRACE
201540adea3SMasami Hiramatsu	select HAVE_FUNCTION_ERROR_INJECTION
2026471b825SIngo Molnar	select HAVE_KRETPROBES
2036471b825SIngo Molnar	select HAVE_KVM
2046471b825SIngo Molnar	select HAVE_LIVEPATCH			if X86_64
2050102752eSFrederic Weisbecker	select HAVE_MIXED_BREAKPOINTS_REGS
206ee9f8fceSJosh Poimboeuf	select HAVE_MOD_ARCH_SPECIFIC
2079f132f7eSJoel Fernandes (Google)	select HAVE_MOVE_PMD
208be37c98dSKalesh Singh	select HAVE_MOVE_PUD
20942a0bb3fSPetr Mladek	select HAVE_NMI
2106471b825SIngo Molnar	select HAVE_OPROFILE
2116471b825SIngo Molnar	select HAVE_OPTPROBES
2126471b825SIngo Molnar	select HAVE_PCSPKR_PLATFORM
2136471b825SIngo Molnar	select HAVE_PERF_EVENTS
214c01d4323SFrederic Weisbecker	select HAVE_PERF_EVENTS_NMI
21592e5aae4SNicholas Piggin	select HAVE_HARDLOCKUP_DETECTOR_PERF	if PERF_EVENTS && HAVE_PERF_EVENTS_NMI
216eb01d42aSChristoph Hellwig	select HAVE_PCI
217c5e63197SJiri Olsa	select HAVE_PERF_REGS
218c5ebcedbSJiri Olsa	select HAVE_PERF_USER_STACK_DUMP
219ff2e6d72SPeter Zijlstra	select MMU_GATHER_RCU_TABLE_FREE		if PARAVIRT
22000998085SThomas Gleixner	select HAVE_POSIX_CPU_TIMERS_TASK_WORK
2216471b825SIngo Molnar	select HAVE_REGS_AND_STACK_ACCESS_API
2226415b38bSJiri Slaby	select HAVE_RELIABLE_STACKTRACE		if X86_64 && (UNWINDER_FRAME_POINTER || UNWINDER_ORC) && STACK_VALIDATION
2233c88ee19SMasami Hiramatsu	select HAVE_FUNCTION_ARG_ACCESS_API
224*cd1a41ceSThomas Gleixner	select HAVE_SOFTIRQ_ON_OWN_STACK
225d148eac0SMasahiro Yamada	select HAVE_STACKPROTECTOR		if CC_HAS_SANE_STACKPROTECTOR
226c763ea26SIngo Molnar	select HAVE_STACK_VALIDATION		if X86_64
227e6d6c071SJosh Poimboeuf	select HAVE_STATIC_CALL
2281e7e4788SJosh Poimboeuf	select HAVE_STATIC_CALL_INLINE		if HAVE_STACK_VALIDATION
229d6761b8fSMathieu Desnoyers	select HAVE_RSEQ
2306471b825SIngo Molnar	select HAVE_SYSCALL_TRACEPOINTS
2316471b825SIngo Molnar	select HAVE_UNSTABLE_SCHED_CLOCK
2327c68af6eSAvi Kivity	select HAVE_USER_RETURN_NOTIFIER
2337ac87074SVincenzo Frascino	select HAVE_GENERIC_VDSO
23405736e4aSThomas Gleixner	select HOTPLUG_SMT			if SMP
235c0185808SThomas Gleixner	select IRQ_FORCED_THREADING
23686596f0aSChristoph Hellwig	select NEED_SG_DMA_LENGTH
2372eac9c2dSChristoph Hellwig	select PCI_DOMAINS			if PCI
238625210cfSSinan Kaya	select PCI_LOCKLESS_CONFIG		if PCI
2396471b825SIngo Molnar	select PERF_EVENTS
2403195ef59SPrarit Bhargava	select RTC_LIB
241d6faca40SArnd Bergmann	select RTC_MC146818_LIB
2426471b825SIngo Molnar	select SPARSE_IRQ
24383fe27eaSPranith Kumar	select SRCU
2441e7e4788SJosh Poimboeuf	select STACK_VALIDATION			if HAVE_STACK_VALIDATION && (HAVE_STATIC_CALL_INLINE || RETPOLINE)
2456471b825SIngo Molnar	select SYSCTL_EXCEPTION_TRACE
24615f4eae7SAndy Lutomirski	select THREAD_INFO_IN_TASK
2476471b825SIngo Molnar	select USER_STACKTRACE_SUPPORT
2486471b825SIngo Molnar	select VIRT_TO_BUS
2493b02a051SIngo Molnar	select HAVE_ARCH_KCSAN			if X86_64
2506471b825SIngo Molnar	select X86_FEATURE_NAMES		if PROC_FS
2510c608dadSAubrey Li	select PROC_PID_ARCH_STATUS		if PROC_FS
2529e2b4be3SNayna Jain	imply IMA_SECURE_AND_OR_TRUSTED_BOOT    if EFI
2537d8330a5SBalbir Singh
254ba7e4d13SIngo Molnarconfig INSTRUCTION_DECODER
2553120e25eSJan Beulich	def_bool y
2563120e25eSJan Beulich	depends on KPROBES || PERF_EVENTS || UPROBES
257ba7e4d13SIngo Molnar
25851b26adaSLinus Torvaldsconfig OUTPUT_FORMAT
25951b26adaSLinus Torvalds	string
26051b26adaSLinus Torvalds	default "elf32-i386" if X86_32
26151b26adaSLinus Torvalds	default "elf64-x86-64" if X86_64
26251b26adaSLinus Torvalds
2638d5fffb9SSam Ravnborgconfig LOCKDEP_SUPPORT
2643c2362e6SHarvey Harrison	def_bool y
2658d5fffb9SSam Ravnborg
2668d5fffb9SSam Ravnborgconfig STACKTRACE_SUPPORT
2673c2362e6SHarvey Harrison	def_bool y
2688d5fffb9SSam Ravnborg
2698d5fffb9SSam Ravnborgconfig MMU
2703c2362e6SHarvey Harrison	def_bool y
2718d5fffb9SSam Ravnborg
2729e08f57dSDaniel Cashmanconfig ARCH_MMAP_RND_BITS_MIN
2739e08f57dSDaniel Cashman	default 28 if 64BIT
2749e08f57dSDaniel Cashman	default 8
2759e08f57dSDaniel Cashman
2769e08f57dSDaniel Cashmanconfig ARCH_MMAP_RND_BITS_MAX
2779e08f57dSDaniel Cashman	default 32 if 64BIT
2789e08f57dSDaniel Cashman	default 16
2799e08f57dSDaniel Cashman
2809e08f57dSDaniel Cashmanconfig ARCH_MMAP_RND_COMPAT_BITS_MIN
2819e08f57dSDaniel Cashman	default 8
2829e08f57dSDaniel Cashman
2839e08f57dSDaniel Cashmanconfig ARCH_MMAP_RND_COMPAT_BITS_MAX
2849e08f57dSDaniel Cashman	default 16
2859e08f57dSDaniel Cashman
2868d5fffb9SSam Ravnborgconfig SBUS
2878d5fffb9SSam Ravnborg	bool
2888d5fffb9SSam Ravnborg
2898d5fffb9SSam Ravnborgconfig GENERIC_ISA_DMA
2903120e25eSJan Beulich	def_bool y
2913120e25eSJan Beulich	depends on ISA_DMA_API
2928d5fffb9SSam Ravnborg
2938d5fffb9SSam Ravnborgconfig GENERIC_BUG
2943c2362e6SHarvey Harrison	def_bool y
2958d5fffb9SSam Ravnborg	depends on BUG
296b93a531eSJan Beulich	select GENERIC_BUG_RELATIVE_POINTERS if X86_64
297b93a531eSJan Beulich
298b93a531eSJan Beulichconfig GENERIC_BUG_RELATIVE_POINTERS
299b93a531eSJan Beulich	bool
3008d5fffb9SSam Ravnborg
3018d5fffb9SSam Ravnborgconfig ARCH_MAY_HAVE_PC_FDC
3023120e25eSJan Beulich	def_bool y
3033120e25eSJan Beulich	depends on ISA_DMA_API
3048d5fffb9SSam Ravnborg
3051032c0baSSam Ravnborgconfig GENERIC_CALIBRATE_DELAY
3061032c0baSSam Ravnborg	def_bool y
3071032c0baSSam Ravnborg
3089a0b8415Svenkatesh.pallipadi@intel.comconfig ARCH_HAS_CPU_RELAX
3099a0b8415Svenkatesh.pallipadi@intel.com	def_bool y
3108d5fffb9SSam Ravnborg
3111b27d05bSPekka Enbergconfig ARCH_HAS_CACHE_LINE_SIZE
3121b27d05bSPekka Enberg	def_bool y
3131b27d05bSPekka Enberg
314316d097cSDave Hansenconfig ARCH_HAS_FILTER_PGPROT
315316d097cSDave Hansen	def_bool y
316316d097cSDave Hansen
317dd5af90aSMike Travisconfig HAVE_SETUP_PER_CPU_AREA
31889c9c4c5SBrian Gerst	def_bool y
319b32ef636Stravis@sgi.com
32008fc4580STejun Heoconfig NEED_PER_CPU_EMBED_FIRST_CHUNK
32108fc4580STejun Heo	def_bool y
32208fc4580STejun Heo
32308fc4580STejun Heoconfig NEED_PER_CPU_PAGE_FIRST_CHUNK
32411124411STejun Heo	def_bool y
32511124411STejun Heo
326801e4062SJohannes Bergconfig ARCH_HIBERNATION_POSSIBLE
327801e4062SJohannes Berg	def_bool y
328801e4062SJohannes Berg
329f4cb5700SJohannes Bergconfig ARCH_SUSPEND_POSSIBLE
330f4cb5700SJohannes Berg	def_bool y
331f4cb5700SJohannes Berg
33253313b2cSSteve Capperconfig ARCH_WANT_GENERAL_HUGETLB
33353313b2cSSteve Capper	def_bool y
33453313b2cSSteve Capper
3358d5fffb9SSam Ravnborgconfig ZONE_DMA32
336e0fd24a3SJan Beulich	def_bool y if X86_64
3378d5fffb9SSam Ravnborg
3388d5fffb9SSam Ravnborgconfig AUDIT_ARCH
339e0fd24a3SJan Beulich	def_bool y if X86_64
3408d5fffb9SSam Ravnborg
341d6f2d75aSAndrey Ryabininconfig KASAN_SHADOW_OFFSET
342d6f2d75aSAndrey Ryabinin	hex
343d6f2d75aSAndrey Ryabinin	depends on KASAN
344d6f2d75aSAndrey Ryabinin	default 0xdffffc0000000000
345d6f2d75aSAndrey Ryabinin
34669575d38SShane Wangconfig HAVE_INTEL_TXT
34769575d38SShane Wang	def_bool y
3486ea30386SKees Cook	depends on INTEL_IOMMU && ACPI
34969575d38SShane Wang
3506b0c3d44SSam Ravnborgconfig X86_32_SMP
3516b0c3d44SSam Ravnborg	def_bool y
3526b0c3d44SSam Ravnborg	depends on X86_32 && SMP
3536b0c3d44SSam Ravnborg
3546b0c3d44SSam Ravnborgconfig X86_64_SMP
3556b0c3d44SSam Ravnborg	def_bool y
3566b0c3d44SSam Ravnborg	depends on X86_64 && SMP
3576b0c3d44SSam Ravnborg
358ccbeed3aSTejun Heoconfig X86_32_LAZY_GS
359ccbeed3aSTejun Heo	def_bool y
3608458f8c2SMasahiro Yamada	depends on X86_32 && !STACKPROTECTOR
361ccbeed3aSTejun Heo
3622b144498SSrikar Dronamrajuconfig ARCH_SUPPORTS_UPROBES
3632b144498SSrikar Dronamraju	def_bool y
3642b144498SSrikar Dronamraju
365d20642f0SRob Herringconfig FIX_EARLYCON_MEM
366d20642f0SRob Herring	def_bool y
367d20642f0SRob Herring
36894d49eb3SKirill A. Shutemovconfig DYNAMIC_PHYSICAL_MASK
36994d49eb3SKirill A. Shutemov	bool
37094d49eb3SKirill A. Shutemov
37198233368SKirill A. Shutemovconfig PGTABLE_LEVELS
37298233368SKirill A. Shutemov	int
37377ef56e4SKirill A. Shutemov	default 5 if X86_5LEVEL
37498233368SKirill A. Shutemov	default 4 if X86_64
37598233368SKirill A. Shutemov	default 3 if X86_PAE
37698233368SKirill A. Shutemov	default 2
37798233368SKirill A. Shutemov
3782a61f474SMasahiro Yamadaconfig CC_HAS_SANE_STACKPROTECTOR
3792a61f474SMasahiro Yamada	bool
3802a61f474SMasahiro Yamada	default $(success,$(srctree)/scripts/gcc-x86_64-has-stack-protector.sh $(CC)) if 64BIT
3812a61f474SMasahiro Yamada	default $(success,$(srctree)/scripts/gcc-x86_32-has-stack-protector.sh $(CC))
3822a61f474SMasahiro Yamada	help
3832a61f474SMasahiro Yamada	   We have to make sure stack protector is unconditionally disabled if
3842a61f474SMasahiro Yamada	   the compiler produces broken code.
3852a61f474SMasahiro Yamada
386506f1d07SSam Ravnborgmenu "Processor type and features"
387506f1d07SSam Ravnborg
3885ee71535SRandy Dunlapconfig ZONE_DMA
3895ee71535SRandy Dunlap	bool "DMA memory allocation support" if EXPERT
3905ee71535SRandy Dunlap	default y
3915ee71535SRandy Dunlap	help
3925ee71535SRandy Dunlap	  DMA memory allocation support allows devices with less than 32-bit
3935ee71535SRandy Dunlap	  addressing to allocate within the first 16MB of address space.
3945ee71535SRandy Dunlap	  Disable if no such devices will be used.
3955ee71535SRandy Dunlap
3965ee71535SRandy Dunlap	  If unsure, say Y.
3975ee71535SRandy Dunlap
398506f1d07SSam Ravnborgconfig SMP
399506f1d07SSam Ravnborg	bool "Symmetric multi-processing support"
400a7f7f624SMasahiro Yamada	help
401506f1d07SSam Ravnborg	  This enables support for systems with more than one CPU. If you have
4024a474157SRobert Graffham	  a system with only one CPU, say N. If you have a system with more
4034a474157SRobert Graffham	  than one CPU, say Y.
404506f1d07SSam Ravnborg
4054a474157SRobert Graffham	  If you say N here, the kernel will run on uni- and multiprocessor
406506f1d07SSam Ravnborg	  machines, but will use only one CPU of a multiprocessor machine. If
407506f1d07SSam Ravnborg	  you say Y here, the kernel will run on many, but not all,
4084a474157SRobert Graffham	  uniprocessor machines. On a uniprocessor machine, the kernel
409506f1d07SSam Ravnborg	  will run faster if you say N here.
410506f1d07SSam Ravnborg
411506f1d07SSam Ravnborg	  Note that if you say Y here and choose architecture "586" or
412506f1d07SSam Ravnborg	  "Pentium" under "Processor family", the kernel will not work on 486
413506f1d07SSam Ravnborg	  architectures. Similarly, multiprocessor kernels for the "PPro"
414506f1d07SSam Ravnborg	  architecture may not work on all Pentium based boards.
415506f1d07SSam Ravnborg
416506f1d07SSam Ravnborg	  People using multiprocessor machines who say Y here should also say
417506f1d07SSam Ravnborg	  Y to "Enhanced Real Time Clock Support", below. The "Advanced Power
418506f1d07SSam Ravnborg	  Management" code will be disabled if you say Y here.
419506f1d07SSam Ravnborg
420cb1aaebeSMauro Carvalho Chehab	  See also <file:Documentation/x86/i386/IO-APIC.rst>,
4214f4cfa6cSMauro Carvalho Chehab	  <file:Documentation/admin-guide/lockup-watchdogs.rst> and the SMP-HOWTO available at
422506f1d07SSam Ravnborg	  <http://www.tldp.org/docs.html#howto>.
423506f1d07SSam Ravnborg
424506f1d07SSam Ravnborg	  If you don't know what to do here, say N.
425506f1d07SSam Ravnborg
4269def39beSJosh Triplettconfig X86_FEATURE_NAMES
4279def39beSJosh Triplett	bool "Processor feature human-readable names" if EMBEDDED
4289def39beSJosh Triplett	default y
429a7f7f624SMasahiro Yamada	help
4309def39beSJosh Triplett	  This option compiles in a table of x86 feature bits and corresponding
4319def39beSJosh Triplett	  names.  This is required to support /proc/cpuinfo and a few kernel
4329def39beSJosh Triplett	  messages.  You can disable this to save space, at the expense of
4339def39beSJosh Triplett	  making those few kernel messages show numeric feature bits instead.
4349def39beSJosh Triplett
4359def39beSJosh Triplett	  If in doubt, say Y.
4369def39beSJosh Triplett
43706cd9a7dSYinghai Luconfig X86_X2APIC
43806cd9a7dSYinghai Lu	bool "Support x2apic"
43919e3d60dSJan Kiszka	depends on X86_LOCAL_APIC && X86_64 && (IRQ_REMAP || HYPERVISOR_GUEST)
440a7f7f624SMasahiro Yamada	help
44106cd9a7dSYinghai Lu	  This enables x2apic support on CPUs that have this feature.
44206cd9a7dSYinghai Lu
44306cd9a7dSYinghai Lu	  This allows 32-bit apic IDs (so it can support very large systems),
44406cd9a7dSYinghai Lu	  and accesses the local apic via MSRs not via mmio.
44506cd9a7dSYinghai Lu
44606cd9a7dSYinghai Lu	  If you don't know what to do here, say N.
44706cd9a7dSYinghai Lu
4486695c85bSYinghai Luconfig X86_MPPARSE
4496e87f9b7SBin Gao	bool "Enable MPS table" if ACPI || SFI
4507a527688SJan Beulich	default y
4515ab74722SIngo Molnar	depends on X86_LOCAL_APIC
452a7f7f624SMasahiro Yamada	help
4536695c85bSYinghai Lu	  For old smp systems that do not have proper acpi support. Newer systems
4546695c85bSYinghai Lu	  (esp with 64bit cpus) with acpi support, MADT and DSDT will override it
4556695c85bSYinghai Lu
456ddd70cf9SJun Nakajimaconfig GOLDFISH
457ddd70cf9SJun Nakajima	def_bool y
458ddd70cf9SJun Nakajima	depends on X86_GOLDFISH
459ddd70cf9SJun Nakajima
46076b04384SDavid Woodhouseconfig RETPOLINE
46176b04384SDavid Woodhouse	bool "Avoid speculative indirect branches in kernel"
46276b04384SDavid Woodhouse	default y
46376b04384SDavid Woodhouse	help
46476b04384SDavid Woodhouse	  Compile kernel with the retpoline compiler options to guard against
46576b04384SDavid Woodhouse	  kernel-to-user data leaks by avoiding speculative indirect
46676b04384SDavid Woodhouse	  branches. Requires a compiler with -mindirect-branch=thunk-extern
46776b04384SDavid Woodhouse	  support for full protection. The kernel may run slower.
46876b04384SDavid Woodhouse
469e6d42931SJohannes Weinerconfig X86_CPU_RESCTRL
470e6d42931SJohannes Weiner	bool "x86 CPU resource control support"
4716fe07ce3SBabu Moger	depends on X86 && (CPU_SUP_INTEL || CPU_SUP_AMD)
47259fe5a77SThomas Gleixner	select KERNFS
473e79f15a4SChen Yu	select PROC_CPU_RESCTRL		if PROC_FS
47478e99b4aSFenghua Yu	help
475e6d42931SJohannes Weiner	  Enable x86 CPU resource control support.
4766fe07ce3SBabu Moger
4776fe07ce3SBabu Moger	  Provide support for the allocation and monitoring of system resources
4786fe07ce3SBabu Moger	  usage by the CPU.
4796fe07ce3SBabu Moger
4806fe07ce3SBabu Moger	  Intel calls this Intel Resource Director Technology
4816fe07ce3SBabu Moger	  (Intel(R) RDT). More information about RDT can be found in the
4826fe07ce3SBabu Moger	  Intel x86 Architecture Software Developer Manual.
4836fe07ce3SBabu Moger
4846fe07ce3SBabu Moger	  AMD calls this AMD Platform Quality of Service (AMD QoS).
4856fe07ce3SBabu Moger	  More information about AMD QoS can be found in the AMD64 Technology
4866fe07ce3SBabu Moger	  Platform Quality of Service Extensions manual.
48778e99b4aSFenghua Yu
48878e99b4aSFenghua Yu	  Say N if unsure.
48978e99b4aSFenghua Yu
4908425091fSRavikiran G Thirumalaiif X86_32
491a0d0bb4dSRandy Dunlapconfig X86_BIGSMP
492a0d0bb4dSRandy Dunlap	bool "Support for big SMP systems with more than 8 CPUs"
493a0d0bb4dSRandy Dunlap	depends on SMP
494a7f7f624SMasahiro Yamada	help
495e133f6eaSRandy Dunlap	  This option is needed for the systems that have more than 8 CPUs.
496a0d0bb4dSRandy Dunlap
497c5c606d9SRavikiran G Thirumalaiconfig X86_EXTENDED_PLATFORM
498c5c606d9SRavikiran G Thirumalai	bool "Support for extended (non-PC) x86 platforms"
499c5c606d9SRavikiran G Thirumalai	default y
500a7f7f624SMasahiro Yamada	help
50106ac8346SIngo Molnar	  If you disable this option then the kernel will only support
50206ac8346SIngo Molnar	  standard PC platforms. (which covers the vast majority of
50306ac8346SIngo Molnar	  systems out there.)
50406ac8346SIngo Molnar
5058425091fSRavikiran G Thirumalai	  If you enable this option then you'll be able to select support
5068425091fSRavikiran G Thirumalai	  for the following (non-PC) 32 bit x86 platforms:
507cb7b8023SBen Hutchings		Goldfish (Android emulator)
5088425091fSRavikiran G Thirumalai		AMD Elan
5098425091fSRavikiran G Thirumalai		RDC R-321x SoC
5108425091fSRavikiran G Thirumalai		SGI 320/540 (Visual Workstation)
51183125a3aSAlessandro Rubini		STA2X11-based (e.g. Northville)
5123f4110a4SThomas Gleixner		Moorestown MID devices
51306ac8346SIngo Molnar
51406ac8346SIngo Molnar	  If you have one of these systems, or if you want to build a
51506ac8346SIngo Molnar	  generic distribution kernel, say Y here - otherwise say N.
5168425091fSRavikiran G Thirumalaiendif
51706ac8346SIngo Molnar
5188425091fSRavikiran G Thirumalaiif X86_64
5198425091fSRavikiran G Thirumalaiconfig X86_EXTENDED_PLATFORM
5208425091fSRavikiran G Thirumalai	bool "Support for extended (non-PC) x86 platforms"
5218425091fSRavikiran G Thirumalai	default y
522a7f7f624SMasahiro Yamada	help
5238425091fSRavikiran G Thirumalai	  If you disable this option then the kernel will only support
5248425091fSRavikiran G Thirumalai	  standard PC platforms. (which covers the vast majority of
5258425091fSRavikiran G Thirumalai	  systems out there.)
5268425091fSRavikiran G Thirumalai
5278425091fSRavikiran G Thirumalai	  If you enable this option then you'll be able to select support
5288425091fSRavikiran G Thirumalai	  for the following (non-PC) 64 bit x86 platforms:
52944b111b5SSteffen Persvold		Numascale NumaChip
5308425091fSRavikiran G Thirumalai		ScaleMP vSMP
5318425091fSRavikiran G Thirumalai		SGI Ultraviolet
5328425091fSRavikiran G Thirumalai
5338425091fSRavikiran G Thirumalai	  If you have one of these systems, or if you want to build a
5348425091fSRavikiran G Thirumalai	  generic distribution kernel, say Y here - otherwise say N.
5358425091fSRavikiran G Thirumalaiendif
536c5c606d9SRavikiran G Thirumalai# This is an alphabetically sorted list of 64 bit extended platforms
537c5c606d9SRavikiran G Thirumalai# Please maintain the alphabetic order if and when there are additions
53844b111b5SSteffen Persvoldconfig X86_NUMACHIP
53944b111b5SSteffen Persvold	bool "Numascale NumaChip"
54044b111b5SSteffen Persvold	depends on X86_64
54144b111b5SSteffen Persvold	depends on X86_EXTENDED_PLATFORM
54244b111b5SSteffen Persvold	depends on NUMA
54344b111b5SSteffen Persvold	depends on SMP
54444b111b5SSteffen Persvold	depends on X86_X2APIC
545f9726bfdSDaniel J Blueman	depends on PCI_MMCONFIG
546a7f7f624SMasahiro Yamada	help
54744b111b5SSteffen Persvold	  Adds support for Numascale NumaChip large-SMP systems. Needed to
54844b111b5SSteffen Persvold	  enable more than ~168 cores.
54944b111b5SSteffen Persvold	  If you don't have one of these, you should say N here.
55003b48632SNick Piggin
5516a48565eSIngo Molnarconfig X86_VSMP
552c5c606d9SRavikiran G Thirumalai	bool "ScaleMP vSMP"
5536276a074SBorislav Petkov	select HYPERVISOR_GUEST
5546a48565eSIngo Molnar	select PARAVIRT
5556a48565eSIngo Molnar	depends on X86_64 && PCI
556c5c606d9SRavikiran G Thirumalai	depends on X86_EXTENDED_PLATFORM
557ead91d4bSShai Fultheim	depends on SMP
558a7f7f624SMasahiro Yamada	help
5596a48565eSIngo Molnar	  Support for ScaleMP vSMP systems.  Say 'Y' here if this kernel is
5606a48565eSIngo Molnar	  supposed to run on these EM64T-based machines.  Only choose this option
5616a48565eSIngo Molnar	  if you have one of these machines.
5626a48565eSIngo Molnar
563c5c606d9SRavikiran G Thirumalaiconfig X86_UV
564c5c606d9SRavikiran G Thirumalai	bool "SGI Ultraviolet"
565c5c606d9SRavikiran G Thirumalai	depends on X86_64
566c5c606d9SRavikiran G Thirumalai	depends on X86_EXTENDED_PLATFORM
56754c28d29SJack Steiner	depends on NUMA
5681ecb4ae5SAndrew Morton	depends on EFI
5699d6c26e7SSuresh Siddha	depends on X86_X2APIC
5701222e564SIngo Molnar	depends on PCI
571a7f7f624SMasahiro Yamada	help
572c5c606d9SRavikiran G Thirumalai	  This option is needed in order to support SGI Ultraviolet systems.
573c5c606d9SRavikiran G Thirumalai	  If you don't have one of these, you should say N here.
574c5c606d9SRavikiran G Thirumalai
575c5c606d9SRavikiran G Thirumalai# Following is an alphabetically sorted list of 32 bit extended platforms
576c5c606d9SRavikiran G Thirumalai# Please maintain the alphabetic order if and when there are additions
577506f1d07SSam Ravnborg
578ddd70cf9SJun Nakajimaconfig X86_GOLDFISH
579ddd70cf9SJun Nakajima	bool "Goldfish (Virtual Platform)"
580cb7b8023SBen Hutchings	depends on X86_EXTENDED_PLATFORM
581a7f7f624SMasahiro Yamada	help
582ddd70cf9SJun Nakajima	 Enable support for the Goldfish virtual platform used primarily
583ddd70cf9SJun Nakajima	 for Android development. Unless you are building for the Android
584ddd70cf9SJun Nakajima	 Goldfish emulator say N here.
585ddd70cf9SJun Nakajima
586c751e17bSThomas Gleixnerconfig X86_INTEL_CE
587c751e17bSThomas Gleixner	bool "CE4100 TV platform"
588c751e17bSThomas Gleixner	depends on PCI
589c751e17bSThomas Gleixner	depends on PCI_GODIRECT
5906084a6e2SJiang Liu	depends on X86_IO_APIC
591c751e17bSThomas Gleixner	depends on X86_32
592c751e17bSThomas Gleixner	depends on X86_EXTENDED_PLATFORM
59337bc9f50SDirk Brandewie	select X86_REBOOTFIXUPS
594da6b737bSSebastian Andrzej Siewior	select OF
595da6b737bSSebastian Andrzej Siewior	select OF_EARLY_FLATTREE
596a7f7f624SMasahiro Yamada	help
597c751e17bSThomas Gleixner	  Select for the Intel CE media processor (CE4100) SOC.
598c751e17bSThomas Gleixner	  This option compiles in support for the CE4100 SOC for settop
599c751e17bSThomas Gleixner	  boxes and media devices.
600c751e17bSThomas Gleixner
6014cb9b00fSDavid Cohenconfig X86_INTEL_MID
60243605ef1SAlan Cox	bool "Intel MID platform support"
60343605ef1SAlan Cox	depends on X86_EXTENDED_PLATFORM
604edc6bc78SDavid Cohen	depends on X86_PLATFORM_DEVICES
6051ea7c673SAlan Cox	depends on PCI
6063fda5bb4SAndy Shevchenko	depends on X86_64 || (PCI_GOANY && X86_32)
6071ea7c673SAlan Cox	depends on X86_IO_APIC
6087c9c3a1eSAlan Cox	select SFI
6094cb9b00fSDavid Cohen	select I2C
6107c9c3a1eSAlan Cox	select DW_APB_TIMER
6111ea7c673SAlan Cox	select APB_TIMER
61254b34aa0SMika Westerberg	select INTEL_SCU_PCI
61315a713dfSMika Westerberg	select MFD_INTEL_MSIC
614a7f7f624SMasahiro Yamada	help
6154cb9b00fSDavid Cohen	  Select to build a kernel capable of supporting Intel MID (Mobile
6164cb9b00fSDavid Cohen	  Internet Device) platform systems which do not have the PCI legacy
6174cb9b00fSDavid Cohen	  interfaces. If you are building for a PC class system say N here.
6181ea7c673SAlan Cox
6194cb9b00fSDavid Cohen	  Intel MID platforms are based on an Intel processor and chipset which
6204cb9b00fSDavid Cohen	  consume less power than most of the x86 derivatives.
62143605ef1SAlan Cox
6228bbc2a13SBryan O'Donoghueconfig X86_INTEL_QUARK
6238bbc2a13SBryan O'Donoghue	bool "Intel Quark platform support"
6248bbc2a13SBryan O'Donoghue	depends on X86_32
6258bbc2a13SBryan O'Donoghue	depends on X86_EXTENDED_PLATFORM
6268bbc2a13SBryan O'Donoghue	depends on X86_PLATFORM_DEVICES
6278bbc2a13SBryan O'Donoghue	depends on X86_TSC
6288bbc2a13SBryan O'Donoghue	depends on PCI
6298bbc2a13SBryan O'Donoghue	depends on PCI_GOANY
6308bbc2a13SBryan O'Donoghue	depends on X86_IO_APIC
6318bbc2a13SBryan O'Donoghue	select IOSF_MBI
6328bbc2a13SBryan O'Donoghue	select INTEL_IMR
6339ab6eb51SAndy Shevchenko	select COMMON_CLK
634a7f7f624SMasahiro Yamada	help
6358bbc2a13SBryan O'Donoghue	  Select to include support for Quark X1000 SoC.
6368bbc2a13SBryan O'Donoghue	  Say Y here if you have a Quark based system such as the Arduino
6378bbc2a13SBryan O'Donoghue	  compatible Intel Galileo.
6388bbc2a13SBryan O'Donoghue
6393d48aab1SMika Westerbergconfig X86_INTEL_LPSS
6403d48aab1SMika Westerberg	bool "Intel Low Power Subsystem Support"
6415962dd22SSinan Kaya	depends on X86 && ACPI && PCI
6423d48aab1SMika Westerberg	select COMMON_CLK
6430f531431SMathias Nyman	select PINCTRL
644eebb3e8dSAndy Shevchenko	select IOSF_MBI
645a7f7f624SMasahiro Yamada	help
6463d48aab1SMika Westerberg	  Select to build support for Intel Low Power Subsystem such as
6473d48aab1SMika Westerberg	  found on Intel Lynxpoint PCH. Selecting this option enables
6480f531431SMathias Nyman	  things like clock tree (common clock framework) and pincontrol
6490f531431SMathias Nyman	  which are needed by the LPSS peripheral drivers.
6503d48aab1SMika Westerberg
65192082a88SKen Xueconfig X86_AMD_PLATFORM_DEVICE
65292082a88SKen Xue	bool "AMD ACPI2Platform devices support"
65392082a88SKen Xue	depends on ACPI
65492082a88SKen Xue	select COMMON_CLK
65592082a88SKen Xue	select PINCTRL
656a7f7f624SMasahiro Yamada	help
65792082a88SKen Xue	  Select to interpret AMD specific ACPI device to platform device
65892082a88SKen Xue	  such as I2C, UART, GPIO found on AMD Carrizo and later chipsets.
65992082a88SKen Xue	  I2C and UART depend on COMMON_CLK to set clock. GPIO driver is
66092082a88SKen Xue	  implemented under PINCTRL subsystem.
66192082a88SKen Xue
662ced3ce76SDavid E. Boxconfig IOSF_MBI
663ced3ce76SDavid E. Box	tristate "Intel SoC IOSF Sideband support for SoC platforms"
664ced3ce76SDavid E. Box	depends on PCI
665a7f7f624SMasahiro Yamada	help
666ced3ce76SDavid E. Box	  This option enables sideband register access support for Intel SoC
667ced3ce76SDavid E. Box	  platforms. On these platforms the IOSF sideband is used in lieu of
668ced3ce76SDavid E. Box	  MSR's for some register accesses, mostly but not limited to thermal
669ced3ce76SDavid E. Box	  and power. Drivers may query the availability of this device to
670ced3ce76SDavid E. Box	  determine if they need the sideband in order to work on these
671ced3ce76SDavid E. Box	  platforms. The sideband is available on the following SoC products.
672ced3ce76SDavid E. Box	  This list is not meant to be exclusive.
673ced3ce76SDavid E. Box	   - BayTrail
674ced3ce76SDavid E. Box	   - Braswell
675ced3ce76SDavid E. Box	   - Quark
676ced3ce76SDavid E. Box
677ced3ce76SDavid E. Box	  You should say Y if you are running a kernel on one of these SoC's.
678ced3ce76SDavid E. Box
679ed2226bdSDavid E. Boxconfig IOSF_MBI_DEBUG
680ed2226bdSDavid E. Box	bool "Enable IOSF sideband access through debugfs"
681ed2226bdSDavid E. Box	depends on IOSF_MBI && DEBUG_FS
682a7f7f624SMasahiro Yamada	help
683ed2226bdSDavid E. Box	  Select this option to expose the IOSF sideband access registers (MCR,
684ed2226bdSDavid E. Box	  MDR, MCRX) through debugfs to write and read register information from
685ed2226bdSDavid E. Box	  different units on the SoC. This is most useful for obtaining device
686ed2226bdSDavid E. Box	  state information for debug and analysis. As this is a general access
687ed2226bdSDavid E. Box	  mechanism, users of this option would have specific knowledge of the
688ed2226bdSDavid E. Box	  device they want to access.
689ed2226bdSDavid E. Box
690ed2226bdSDavid E. Box	  If you don't require the option or are in doubt, say N.
691ed2226bdSDavid E. Box
692c5c606d9SRavikiran G Thirumalaiconfig X86_RDC321X
693c5c606d9SRavikiran G Thirumalai	bool "RDC R-321x SoC"
694506f1d07SSam Ravnborg	depends on X86_32
695c5c606d9SRavikiran G Thirumalai	depends on X86_EXTENDED_PLATFORM
696c5c606d9SRavikiran G Thirumalai	select M486
697c5c606d9SRavikiran G Thirumalai	select X86_REBOOTFIXUPS
698a7f7f624SMasahiro Yamada	help
699c5c606d9SRavikiran G Thirumalai	  This option is needed for RDC R-321x system-on-chip, also known
700c5c606d9SRavikiran G Thirumalai	  as R-8610-(G).
701c5c606d9SRavikiran G Thirumalai	  If you don't have one of these chips, you should say N here.
702c5c606d9SRavikiran G Thirumalai
703e0c7ae37SIngo Molnarconfig X86_32_NON_STANDARD
7049c398017SIngo Molnar	bool "Support non-standard 32-bit SMP architectures"
7059c398017SIngo Molnar	depends on X86_32 && SMP
706c5c606d9SRavikiran G Thirumalai	depends on X86_EXTENDED_PLATFORM
707a7f7f624SMasahiro Yamada	help
708b5660ba7SH. Peter Anvin	  This option compiles in the bigsmp and STA2X11 default
709b5660ba7SH. Peter Anvin	  subarchitectures.  It is intended for a generic binary
710b5660ba7SH. Peter Anvin	  kernel. If you select them all, kernel will probe it one by
711b5660ba7SH. Peter Anvin	  one and will fallback to default.
712d49c4288SYinghai Lu
713c5c606d9SRavikiran G Thirumalai# Alphabetically sorted list of Non standard 32 bit platforms
714d49c4288SYinghai Lu
715d949f36fSLinus Torvaldsconfig X86_SUPPORTS_MEMORY_FAILURE
7166fc108a0SJan Beulich	def_bool y
717d949f36fSLinus Torvalds	# MCE code calls memory_failure():
718d949f36fSLinus Torvalds	depends on X86_MCE
719d949f36fSLinus Torvalds	# On 32-bit this adds too big of NODES_SHIFT and we run out of page flags:
720d949f36fSLinus Torvalds	# On 32-bit SPARSEMEM adds too big of SECTIONS_WIDTH:
721d949f36fSLinus Torvalds	depends on X86_64 || !SPARSEMEM
722d949f36fSLinus Torvalds	select ARCH_SUPPORTS_MEMORY_FAILURE
723d949f36fSLinus Torvalds
72483125a3aSAlessandro Rubiniconfig STA2X11
72583125a3aSAlessandro Rubini	bool "STA2X11 Companion Chip Support"
72683125a3aSAlessandro Rubini	depends on X86_32_NON_STANDARD && PCI
72783125a3aSAlessandro Rubini	select SWIOTLB
72883125a3aSAlessandro Rubini	select MFD_STA2X11
7290145071bSLinus Walleij	select GPIOLIB
730a7f7f624SMasahiro Yamada	help
73183125a3aSAlessandro Rubini	  This adds support for boards based on the STA2X11 IO-Hub,
73283125a3aSAlessandro Rubini	  a.k.a. "ConneXt". The chip is used in place of the standard
73383125a3aSAlessandro Rubini	  PC chipset, so all "standard" peripherals are missing. If this
73483125a3aSAlessandro Rubini	  option is selected the kernel will still be able to boot on
73583125a3aSAlessandro Rubini	  standard PC machines.
73683125a3aSAlessandro Rubini
73782148d1dSShérabconfig X86_32_IRIS
73882148d1dSShérab	tristate "Eurobraille/Iris poweroff module"
73982148d1dSShérab	depends on X86_32
740a7f7f624SMasahiro Yamada	help
74182148d1dSShérab	  The Iris machines from EuroBraille do not have APM or ACPI support
74282148d1dSShérab	  to shut themselves down properly.  A special I/O sequence is
74382148d1dSShérab	  needed to do so, which is what this module does at
74482148d1dSShérab	  kernel shutdown.
74582148d1dSShérab
74682148d1dSShérab	  This is only for Iris machines from EuroBraille.
74782148d1dSShérab
74882148d1dSShérab	  If unused, say N.
74982148d1dSShérab
750ae1e9130SIngo Molnarconfig SCHED_OMIT_FRAME_POINTER
7513c2362e6SHarvey Harrison	def_bool y
7523c2362e6SHarvey Harrison	prompt "Single-depth WCHAN output"
753a87d0914SKen Chen	depends on X86
754a7f7f624SMasahiro Yamada	help
755506f1d07SSam Ravnborg	  Calculate simpler /proc/<PID>/wchan values. If this option
756506f1d07SSam Ravnborg	  is disabled then wchan values will recurse back to the
757506f1d07SSam Ravnborg	  caller function. This provides more accurate wchan values,
758506f1d07SSam Ravnborg	  at the expense of slightly more scheduling overhead.
759506f1d07SSam Ravnborg
760506f1d07SSam Ravnborg	  If in doubt, say "Y".
761506f1d07SSam Ravnborg
7626276a074SBorislav Petkovmenuconfig HYPERVISOR_GUEST
7636276a074SBorislav Petkov	bool "Linux guest support"
764a7f7f624SMasahiro Yamada	help
7656276a074SBorislav Petkov	  Say Y here to enable options for running Linux under various hyper-
7666276a074SBorislav Petkov	  visors. This option enables basic hypervisor detection and platform
7676276a074SBorislav Petkov	  setup.
768506f1d07SSam Ravnborg
7696276a074SBorislav Petkov	  If you say N, all options in this submenu will be skipped and
7706276a074SBorislav Petkov	  disabled, and Linux guest support won't be built in.
771506f1d07SSam Ravnborg
7726276a074SBorislav Petkovif HYPERVISOR_GUEST
773506f1d07SSam Ravnborg
774e61bd94aSEduardo Pereira Habkostconfig PARAVIRT
775e61bd94aSEduardo Pereira Habkost	bool "Enable paravirtualization code"
776a7f7f624SMasahiro Yamada	help
777e61bd94aSEduardo Pereira Habkost	  This changes the kernel so it can modify itself when it is run
778e61bd94aSEduardo Pereira Habkost	  under a hypervisor, potentially improving performance significantly
779e61bd94aSEduardo Pereira Habkost	  over full virtualization.  However, when run without a hypervisor
780e61bd94aSEduardo Pereira Habkost	  the kernel is theoretically slower and slightly larger.
781e61bd94aSEduardo Pereira Habkost
782c00a280aSJuergen Grossconfig PARAVIRT_XXL
783c00a280aSJuergen Gross	bool
784c00a280aSJuergen Gross
7856276a074SBorislav Petkovconfig PARAVIRT_DEBUG
7866276a074SBorislav Petkov	bool "paravirt-ops debugging"
7876276a074SBorislav Petkov	depends on PARAVIRT && DEBUG_KERNEL
788a7f7f624SMasahiro Yamada	help
7896276a074SBorislav Petkov	  Enable to debug paravirt_ops internals.  Specifically, BUG if
7906276a074SBorislav Petkov	  a paravirt_op is missing when it is called.
7916276a074SBorislav Petkov
792b4ecc126SJeremy Fitzhardingeconfig PARAVIRT_SPINLOCKS
793b4ecc126SJeremy Fitzhardinge	bool "Paravirtualization layer for spinlocks"
7946ea30386SKees Cook	depends on PARAVIRT && SMP
795a7f7f624SMasahiro Yamada	help
796b4ecc126SJeremy Fitzhardinge	  Paravirtualized spinlocks allow a pvops backend to replace the
797b4ecc126SJeremy Fitzhardinge	  spinlock implementation with something virtualization-friendly
798b4ecc126SJeremy Fitzhardinge	  (for example, block the virtual CPU rather than spinning).
799b4ecc126SJeremy Fitzhardinge
8004c4e4f61SRaghavendra K T	  It has a minimal impact on native kernels and gives a nice performance
8014c4e4f61SRaghavendra K T	  benefit on paravirtualized KVM / Xen kernels.
802b4ecc126SJeremy Fitzhardinge
8034c4e4f61SRaghavendra K T	  If you are unsure how to answer this question, answer Y.
804b4ecc126SJeremy Fitzhardinge
805ecca2502SZhao Yakuiconfig X86_HV_CALLBACK_VECTOR
806ecca2502SZhao Yakui	def_bool n
807ecca2502SZhao Yakui
8086276a074SBorislav Petkovsource "arch/x86/xen/Kconfig"
8096276a074SBorislav Petkov
8106276a074SBorislav Petkovconfig KVM_GUEST
8116276a074SBorislav Petkov	bool "KVM Guest support (including kvmclock)"
8126276a074SBorislav Petkov	depends on PARAVIRT
8136276a074SBorislav Petkov	select PARAVIRT_CLOCK
814a1c4423bSMarcelo Tosatti	select ARCH_CPUIDLE_HALTPOLL
815b1d40575SVitaly Kuznetsov	select X86_HV_CALLBACK_VECTOR
8166276a074SBorislav Petkov	default y
817a7f7f624SMasahiro Yamada	help
8186276a074SBorislav Petkov	  This option enables various optimizations for running under the KVM
8196276a074SBorislav Petkov	  hypervisor. It includes a paravirtualized clock, so that instead
8206276a074SBorislav Petkov	  of relying on a PIT (or probably other) emulation by the
8216276a074SBorislav Petkov	  underlying device model, the host provides the guest with
8226276a074SBorislav Petkov	  timing infrastructure such as time of day, and system time
8236276a074SBorislav Petkov
824a1c4423bSMarcelo Tosatticonfig ARCH_CPUIDLE_HALTPOLL
825a1c4423bSMarcelo Tosatti	def_bool n
826a1c4423bSMarcelo Tosatti	prompt "Disable host haltpoll when loading haltpoll driver"
827a1c4423bSMarcelo Tosatti	help
828a1c4423bSMarcelo Tosatti	  If virtualized under KVM, disable host haltpoll.
829a1c4423bSMarcelo Tosatti
8307733607fSMaran Wilsonconfig PVH
8317733607fSMaran Wilson	bool "Support for running PVH guests"
832a7f7f624SMasahiro Yamada	help
8337733607fSMaran Wilson	  This option enables the PVH entry point for guest virtual machines
8347733607fSMaran Wilson	  as specified in the x86/HVM direct boot ABI.
8357733607fSMaran Wilson
8366276a074SBorislav Petkovconfig PARAVIRT_TIME_ACCOUNTING
8376276a074SBorislav Petkov	bool "Paravirtual steal time accounting"
8386276a074SBorislav Petkov	depends on PARAVIRT
839a7f7f624SMasahiro Yamada	help
8406276a074SBorislav Petkov	  Select this option to enable fine granularity task steal time
8416276a074SBorislav Petkov	  accounting. Time spent executing other tasks in parallel with
8426276a074SBorislav Petkov	  the current vCPU is discounted from the vCPU power. To account for
8436276a074SBorislav Petkov	  that, there can be a small performance impact.
8446276a074SBorislav Petkov
8456276a074SBorislav Petkov	  If in doubt, say N here.
8466276a074SBorislav Petkov
8477af192c9SGerd Hoffmannconfig PARAVIRT_CLOCK
8487af192c9SGerd Hoffmann	bool
8497af192c9SGerd Hoffmann
8504a362601SJan Kiszkaconfig JAILHOUSE_GUEST
8514a362601SJan Kiszka	bool "Jailhouse non-root cell support"
852abde587bSArnd Bergmann	depends on X86_64 && PCI
85387e65d05SJan Kiszka	select X86_PM_TIMER
854a7f7f624SMasahiro Yamada	help
8554a362601SJan Kiszka	  This option allows to run Linux as guest in a Jailhouse non-root
8564a362601SJan Kiszka	  cell. You can leave this option disabled if you only want to start
8574a362601SJan Kiszka	  Jailhouse and run Linux afterwards in the root cell.
8584a362601SJan Kiszka
859ec7972c9SZhao Yakuiconfig ACRN_GUEST
860ec7972c9SZhao Yakui	bool "ACRN Guest support"
861ec7972c9SZhao Yakui	depends on X86_64
862498ad393SZhao Yakui	select X86_HV_CALLBACK_VECTOR
863ec7972c9SZhao Yakui	help
864ec7972c9SZhao Yakui	  This option allows to run Linux as guest in the ACRN hypervisor. ACRN is
865ec7972c9SZhao Yakui	  a flexible, lightweight reference open-source hypervisor, built with
866ec7972c9SZhao Yakui	  real-time and safety-criticality in mind. It is built for embedded
867ec7972c9SZhao Yakui	  IOT with small footprint and real-time features. More details can be
868ec7972c9SZhao Yakui	  found in https://projectacrn.org/.
869ec7972c9SZhao Yakui
8706276a074SBorislav Petkovendif #HYPERVISOR_GUEST
87197349135SJeremy Fitzhardinge
872506f1d07SSam Ravnborgsource "arch/x86/Kconfig.cpu"
873506f1d07SSam Ravnborg
874506f1d07SSam Ravnborgconfig HPET_TIMER
8753c2362e6SHarvey Harrison	def_bool X86_64
876506f1d07SSam Ravnborg	prompt "HPET Timer Support" if X86_32
877a7f7f624SMasahiro Yamada	help
878506f1d07SSam Ravnborg	  Use the IA-PC HPET (High Precision Event Timer) to manage
879506f1d07SSam Ravnborg	  time in preference to the PIT and RTC, if a HPET is
880506f1d07SSam Ravnborg	  present.
881506f1d07SSam Ravnborg	  HPET is the next generation timer replacing legacy 8254s.
882506f1d07SSam Ravnborg	  The HPET provides a stable time base on SMP
883506f1d07SSam Ravnborg	  systems, unlike the TSC, but it is more expensive to access,
8844e7f9df2SMichael S. Tsirkin	  as it is off-chip.  The interface used is documented
8854e7f9df2SMichael S. Tsirkin	  in the HPET spec, revision 1.
886506f1d07SSam Ravnborg
887506f1d07SSam Ravnborg	  You can safely choose Y here.  However, HPET will only be
888506f1d07SSam Ravnborg	  activated if the platform and the BIOS support this feature.
889506f1d07SSam Ravnborg	  Otherwise the 8254 will be used for timing services.
890506f1d07SSam Ravnborg
891506f1d07SSam Ravnborg	  Choose N to continue using the legacy 8254 timer.
892506f1d07SSam Ravnborg
893506f1d07SSam Ravnborgconfig HPET_EMULATE_RTC
8943c2362e6SHarvey Harrison	def_bool y
8959d8af78bSBernhard Walle	depends on HPET_TIMER && (RTC=y || RTC=m || RTC_DRV_CMOS=m || RTC_DRV_CMOS=y)
896506f1d07SSam Ravnborg
897bb24c471SJacob Panconfig APB_TIMER
898933b9463SAlan Cox	def_bool y if X86_INTEL_MID
899933b9463SAlan Cox	prompt "Intel MID APB Timer Support" if X86_INTEL_MID
90006c3df49SJamie Iles	select DW_APB_TIMER
901a0c3832aSAlan Cox	depends on X86_INTEL_MID && SFI
902bb24c471SJacob Pan	help
903bb24c471SJacob Pan	 APB timer is the replacement for 8254, HPET on X86 MID platforms.
904bb24c471SJacob Pan	 The APBT provides a stable time base on SMP
905bb24c471SJacob Pan	 systems, unlike the TSC, but it is more expensive to access,
906bb24c471SJacob Pan	 as it is off-chip. APB timers are always running regardless of CPU
907bb24c471SJacob Pan	 C states, they are used as per CPU clockevent device when possible.
908bb24c471SJacob Pan
9096a108a14SDavid Rientjes# Mark as expert because too many people got it wrong.
910506f1d07SSam Ravnborg# The code disables itself when not needed.
9117ae9392cSThomas Petazzoniconfig DMI
9127ae9392cSThomas Petazzoni	default y
913cf074402SArd Biesheuvel	select DMI_SCAN_MACHINE_NON_EFI_FALLBACK
9146a108a14SDavid Rientjes	bool "Enable DMI scanning" if EXPERT
915a7f7f624SMasahiro Yamada	help
9167ae9392cSThomas Petazzoni	  Enabled scanning of DMI to identify machine quirks. Say Y
9177ae9392cSThomas Petazzoni	  here unless you have verified that your setup is not
9187ae9392cSThomas Petazzoni	  affected by entries in the DMI blacklist. Required by PNP
9197ae9392cSThomas Petazzoni	  BIOS code.
9207ae9392cSThomas Petazzoni
921506f1d07SSam Ravnborgconfig GART_IOMMU
92238901f1cSAndi Kleen	bool "Old AMD GART IOMMU support"
9232f9237d4SChristoph Hellwig	select DMA_OPS
924a4ce5a48SChristoph Hellwig	select IOMMU_HELPER
925506f1d07SSam Ravnborg	select SWIOTLB
92623ac4ae8SAndreas Herrmann	depends on X86_64 && PCI && AMD_NB
927a7f7f624SMasahiro Yamada	help
928ced3c42cSIngo Molnar	  Provides a driver for older AMD Athlon64/Opteron/Turion/Sempron
929ced3c42cSIngo Molnar	  GART based hardware IOMMUs.
930ced3c42cSIngo Molnar
931ced3c42cSIngo Molnar	  The GART supports full DMA access for devices with 32-bit access
932ced3c42cSIngo Molnar	  limitations, on systems with more than 3 GB. This is usually needed
933ced3c42cSIngo Molnar	  for USB, sound, many IDE/SATA chipsets and some other devices.
934ced3c42cSIngo Molnar
935ced3c42cSIngo Molnar	  Newer systems typically have a modern AMD IOMMU, supported via
936ced3c42cSIngo Molnar	  the CONFIG_AMD_IOMMU=y config option.
937ced3c42cSIngo Molnar
938ced3c42cSIngo Molnar	  In normal configurations this driver is only active when needed:
939ced3c42cSIngo Molnar	  there's more than 3 GB of memory and the system contains a
940ced3c42cSIngo Molnar	  32-bit limited device.
941ced3c42cSIngo Molnar
942ced3c42cSIngo Molnar	  If unsure, say Y.
943506f1d07SSam Ravnborg
9441184dc2fSMike Travisconfig MAXSMP
945ddb0c5a6SSamuel Thibault	bool "Enable Maximum number of SMP Processors and NUMA Nodes"
9466ea30386SKees Cook	depends on X86_64 && SMP && DEBUG_KERNEL
94736f5101aSMike Travis	select CPUMASK_OFFSTACK
948a7f7f624SMasahiro Yamada	help
949ddb0c5a6SSamuel Thibault	  Enable maximum number of CPUS and NUMA Nodes for this architecture.
9501184dc2fSMike Travis	  If unsure, say N.
951506f1d07SSam Ravnborg
952aec6487eSIngo Molnar#
953aec6487eSIngo Molnar# The maximum number of CPUs supported:
954aec6487eSIngo Molnar#
955aec6487eSIngo Molnar# The main config value is NR_CPUS, which defaults to NR_CPUS_DEFAULT,
956aec6487eSIngo Molnar# and which can be configured interactively in the
957aec6487eSIngo Molnar# [NR_CPUS_RANGE_BEGIN ... NR_CPUS_RANGE_END] range.
958aec6487eSIngo Molnar#
959aec6487eSIngo Molnar# The ranges are different on 32-bit and 64-bit kernels, depending on
960aec6487eSIngo Molnar# hardware capabilities and scalability features of the kernel.
961aec6487eSIngo Molnar#
962aec6487eSIngo Molnar# ( If MAXSMP is enabled we just use the highest possible value and disable
963aec6487eSIngo Molnar#   interactive configuration. )
964aec6487eSIngo Molnar#
965a0d0bb4dSRandy Dunlap
966aec6487eSIngo Molnarconfig NR_CPUS_RANGE_BEGIN
967a0d0bb4dSRandy Dunlap	int
968aec6487eSIngo Molnar	default NR_CPUS_RANGE_END if MAXSMP
969a0d0bb4dSRandy Dunlap	default    1 if !SMP
970a0d0bb4dSRandy Dunlap	default    2
971a0d0bb4dSRandy Dunlap
972aec6487eSIngo Molnarconfig NR_CPUS_RANGE_END
973a0d0bb4dSRandy Dunlap	int
974a0d0bb4dSRandy Dunlap	depends on X86_32
975aec6487eSIngo Molnar	default   64 if  SMP &&  X86_BIGSMP
976aec6487eSIngo Molnar	default    8 if  SMP && !X86_BIGSMP
977a0d0bb4dSRandy Dunlap	default    1 if !SMP
978a0d0bb4dSRandy Dunlap
979aec6487eSIngo Molnarconfig NR_CPUS_RANGE_END
980a0d0bb4dSRandy Dunlap	int
981a0d0bb4dSRandy Dunlap	depends on X86_64
9821edae1aeSScott Wood	default 8192 if  SMP && CPUMASK_OFFSTACK
9831edae1aeSScott Wood	default  512 if  SMP && !CPUMASK_OFFSTACK
984a0d0bb4dSRandy Dunlap	default    1 if !SMP
985aec6487eSIngo Molnar
986aec6487eSIngo Molnarconfig NR_CPUS_DEFAULT
987aec6487eSIngo Molnar	int
988aec6487eSIngo Molnar	depends on X86_32
989aec6487eSIngo Molnar	default   32 if  X86_BIGSMP
990aec6487eSIngo Molnar	default    8 if  SMP
991aec6487eSIngo Molnar	default    1 if !SMP
992aec6487eSIngo Molnar
993aec6487eSIngo Molnarconfig NR_CPUS_DEFAULT
994aec6487eSIngo Molnar	int
995aec6487eSIngo Molnar	depends on X86_64
996a0d0bb4dSRandy Dunlap	default 8192 if  MAXSMP
997a0d0bb4dSRandy Dunlap	default   64 if  SMP
998aec6487eSIngo Molnar	default    1 if !SMP
999a0d0bb4dSRandy Dunlap
1000506f1d07SSam Ravnborgconfig NR_CPUS
100136f5101aSMike Travis	int "Maximum number of CPUs" if SMP && !MAXSMP
1002aec6487eSIngo Molnar	range NR_CPUS_RANGE_BEGIN NR_CPUS_RANGE_END
1003aec6487eSIngo Molnar	default NR_CPUS_DEFAULT
1004a7f7f624SMasahiro Yamada	help
1005506f1d07SSam Ravnborg	  This allows you to specify the maximum number of CPUs which this
1006bb61ccc7SJosh Boyer	  kernel will support.  If CPUMASK_OFFSTACK is enabled, the maximum
1007cad14bb9SKirill A. Shutemov	  supported value is 8192, otherwise the maximum value is 512.  The
1008506f1d07SSam Ravnborg	  minimum value which makes sense is 2.
1009506f1d07SSam Ravnborg
1010aec6487eSIngo Molnar	  This is purely to save memory: each supported CPU adds about 8KB
1011aec6487eSIngo Molnar	  to the kernel image.
1012506f1d07SSam Ravnborg
1013506f1d07SSam Ravnborgconfig SCHED_SMT
1014dbe73364SThomas Gleixner	def_bool y if SMP
1015506f1d07SSam Ravnborg
1016506f1d07SSam Ravnborgconfig SCHED_MC
10173c2362e6SHarvey Harrison	def_bool y
10183c2362e6SHarvey Harrison	prompt "Multi-core scheduler support"
1019c8e56d20SBorislav Petkov	depends on SMP
1020a7f7f624SMasahiro Yamada	help
1021506f1d07SSam Ravnborg	  Multi-core scheduler support improves the CPU scheduler's decision
1022506f1d07SSam Ravnborg	  making when dealing with multi-core CPU chips at a cost of slightly
1023506f1d07SSam Ravnborg	  increased overhead in some places. If unsure say N here.
1024506f1d07SSam Ravnborg
1025de966cf4STim Chenconfig SCHED_MC_PRIO
1026de966cf4STim Chen	bool "CPU core priorities scheduler support"
10270a21fc12SIngo Molnar	depends on SCHED_MC && CPU_SUP_INTEL
10280a21fc12SIngo Molnar	select X86_INTEL_PSTATE
10290a21fc12SIngo Molnar	select CPU_FREQ
1030de966cf4STim Chen	default y
1031a7f7f624SMasahiro Yamada	help
1032de966cf4STim Chen	  Intel Turbo Boost Max Technology 3.0 enabled CPUs have a
1033de966cf4STim Chen	  core ordering determined at manufacturing time, which allows
1034de966cf4STim Chen	  certain cores to reach higher turbo frequencies (when running
1035de966cf4STim Chen	  single threaded workloads) than others.
1036de966cf4STim Chen
1037de966cf4STim Chen	  Enabling this kernel feature teaches the scheduler about
1038de966cf4STim Chen	  the TBM3 (aka ITMT) priority order of the CPU cores and adjusts the
1039de966cf4STim Chen	  scheduler's CPU selection logic accordingly, so that higher
1040de966cf4STim Chen	  overall system performance can be achieved.
1041de966cf4STim Chen
1042de966cf4STim Chen	  This feature will have no effect on CPUs without this feature.
1043de966cf4STim Chen
1044de966cf4STim Chen	  If unsure say Y here.
10455e76b2abSTim Chen
104630b8b006SThomas Gleixnerconfig UP_LATE_INIT
104730b8b006SThomas Gleixner	def_bool y
1048ba360f88SThomas Gleixner	depends on !SMP && X86_LOCAL_APIC
104930b8b006SThomas Gleixner
1050506f1d07SSam Ravnborgconfig X86_UP_APIC
105150849eefSJan Beulich	bool "Local APIC support on uniprocessors" if !PCI_MSI
105250849eefSJan Beulich	default PCI_MSI
105338a1dfdaSBryan O'Donoghue	depends on X86_32 && !SMP && !X86_32_NON_STANDARD
1054a7f7f624SMasahiro Yamada	help
1055506f1d07SSam Ravnborg	  A local APIC (Advanced Programmable Interrupt Controller) is an
1056506f1d07SSam Ravnborg	  integrated interrupt controller in the CPU. If you have a single-CPU
1057506f1d07SSam Ravnborg	  system which has a processor with a local APIC, you can say Y here to
1058506f1d07SSam Ravnborg	  enable and use it. If you say Y here even though your machine doesn't
1059506f1d07SSam Ravnborg	  have a local APIC, then the kernel will still run with no slowdown at
1060506f1d07SSam Ravnborg	  all. The local APIC supports CPU-generated self-interrupts (timer,
1061506f1d07SSam Ravnborg	  performance counters), and the NMI watchdog which detects hard
1062506f1d07SSam Ravnborg	  lockups.
1063506f1d07SSam Ravnborg
1064506f1d07SSam Ravnborgconfig X86_UP_IOAPIC
1065506f1d07SSam Ravnborg	bool "IO-APIC support on uniprocessors"
1066506f1d07SSam Ravnborg	depends on X86_UP_APIC
1067a7f7f624SMasahiro Yamada	help
1068506f1d07SSam Ravnborg	  An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an
1069506f1d07SSam Ravnborg	  SMP-capable replacement for PC-style interrupt controllers. Most
1070506f1d07SSam Ravnborg	  SMP systems and many recent uniprocessor systems have one.
1071506f1d07SSam Ravnborg
1072506f1d07SSam Ravnborg	  If you have a single-CPU system with an IO-APIC, you can say Y here
1073506f1d07SSam Ravnborg	  to use it. If you say Y here even though your machine doesn't have
1074506f1d07SSam Ravnborg	  an IO-APIC, then the kernel will still run with no slowdown at all.
1075506f1d07SSam Ravnborg
1076506f1d07SSam Ravnborgconfig X86_LOCAL_APIC
10773c2362e6SHarvey Harrison	def_bool y
10780dbc6078SThomas Petazzoni	depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC || PCI_MSI
1079b5dc8e6cSJiang Liu	select IRQ_DOMAIN_HIERARCHY
108052f518a3SJiang Liu	select PCI_MSI_IRQ_DOMAIN if PCI_MSI
1081506f1d07SSam Ravnborg
1082506f1d07SSam Ravnborgconfig X86_IO_APIC
1083b1da1e71SJan Beulich	def_bool y
1084b1da1e71SJan Beulich	depends on X86_LOCAL_APIC || X86_UP_IOAPIC
1085506f1d07SSam Ravnborg
108641b9eb26SStefan Assmannconfig X86_REROUTE_FOR_BROKEN_BOOT_IRQS
108741b9eb26SStefan Assmann	bool "Reroute for broken boot IRQs"
108841b9eb26SStefan Assmann	depends on X86_IO_APIC
1089a7f7f624SMasahiro Yamada	help
109041b9eb26SStefan Assmann	  This option enables a workaround that fixes a source of
109141b9eb26SStefan Assmann	  spurious interrupts. This is recommended when threaded
109241b9eb26SStefan Assmann	  interrupt handling is used on systems where the generation of
109341b9eb26SStefan Assmann	  superfluous "boot interrupts" cannot be disabled.
109441b9eb26SStefan Assmann
109541b9eb26SStefan Assmann	  Some chipsets generate a legacy INTx "boot IRQ" when the IRQ
109641b9eb26SStefan Assmann	  entry in the chipset's IO-APIC is masked (as, e.g. the RT
109741b9eb26SStefan Assmann	  kernel does during interrupt handling). On chipsets where this
109841b9eb26SStefan Assmann	  boot IRQ generation cannot be disabled, this workaround keeps
109941b9eb26SStefan Assmann	  the original IRQ line masked so that only the equivalent "boot
110041b9eb26SStefan Assmann	  IRQ" is delivered to the CPUs. The workaround also tells the
110141b9eb26SStefan Assmann	  kernel to set up the IRQ handler on the boot IRQ line. In this
110241b9eb26SStefan Assmann	  way only one interrupt is delivered to the kernel. Otherwise
110341b9eb26SStefan Assmann	  the spurious second interrupt may cause the kernel to bring
110441b9eb26SStefan Assmann	  down (vital) interrupt lines.
110541b9eb26SStefan Assmann
110641b9eb26SStefan Assmann	  Only affects "broken" chipsets. Interrupt sharing may be
110741b9eb26SStefan Assmann	  increased on these systems.
110841b9eb26SStefan Assmann
1109506f1d07SSam Ravnborgconfig X86_MCE
1110bab9bc65SAndi Kleen	bool "Machine Check / overheating reporting"
1111648ed940SChen, Gong	select GENERIC_ALLOCATOR
1112e57dbaf7SBorislav Petkov	default y
1113a7f7f624SMasahiro Yamada	help
1114bab9bc65SAndi Kleen	  Machine Check support allows the processor to notify the
1115bab9bc65SAndi Kleen	  kernel if it detects a problem (e.g. overheating, data corruption).
1116506f1d07SSam Ravnborg	  The action the kernel takes depends on the severity of the problem,
1117bab9bc65SAndi Kleen	  ranging from warning messages to halting the machine.
11184efc0670SAndi Kleen
11195de97c9fSTony Luckconfig X86_MCELOG_LEGACY
11205de97c9fSTony Luck	bool "Support for deprecated /dev/mcelog character device"
11215de97c9fSTony Luck	depends on X86_MCE
1122a7f7f624SMasahiro Yamada	help
11235de97c9fSTony Luck	  Enable support for /dev/mcelog which is needed by the old mcelog
11245de97c9fSTony Luck	  userspace logging daemon. Consider switching to the new generation
11255de97c9fSTony Luck	  rasdaemon solution.
11265de97c9fSTony Luck
1127506f1d07SSam Ravnborgconfig X86_MCE_INTEL
11283c2362e6SHarvey Harrison	def_bool y
11293c2362e6SHarvey Harrison	prompt "Intel MCE features"
1130c1ebf835SAndi Kleen	depends on X86_MCE && X86_LOCAL_APIC
1131a7f7f624SMasahiro Yamada	help
1132506f1d07SSam Ravnborg	   Additional support for intel specific MCE features such as
1133506f1d07SSam Ravnborg	   the thermal monitor.
1134506f1d07SSam Ravnborg
1135506f1d07SSam Ravnborgconfig X86_MCE_AMD
11363c2362e6SHarvey Harrison	def_bool y
11373c2362e6SHarvey Harrison	prompt "AMD MCE features"
1138f5382de9SYazen Ghannam	depends on X86_MCE && X86_LOCAL_APIC && AMD_NB
1139a7f7f624SMasahiro Yamada	help
1140506f1d07SSam Ravnborg	   Additional support for AMD specific MCE features such as
1141506f1d07SSam Ravnborg	   the DRAM Error Threshold.
1142506f1d07SSam Ravnborg
11434efc0670SAndi Kleenconfig X86_ANCIENT_MCE
11446fc108a0SJan Beulich	bool "Support for old Pentium 5 / WinChip machine checks"
1145c31d9633SAndi Kleen	depends on X86_32 && X86_MCE
1146a7f7f624SMasahiro Yamada	help
11474efc0670SAndi Kleen	  Include support for machine check handling on old Pentium 5 or WinChip
11485065a706SMasanari Iida	  systems. These typically need to be enabled explicitly on the command
11494efc0670SAndi Kleen	  line.
11504efc0670SAndi Kleen
1151b2762686SAndi Kleenconfig X86_MCE_THRESHOLD
1152b2762686SAndi Kleen	depends on X86_MCE_AMD || X86_MCE_INTEL
11536fc108a0SJan Beulich	def_bool y
1154b2762686SAndi Kleen
1155ea149b36SAndi Kleenconfig X86_MCE_INJECT
1156bc8e80d5SBorislav Petkov	depends on X86_MCE && X86_LOCAL_APIC && DEBUG_FS
1157ea149b36SAndi Kleen	tristate "Machine check injector support"
1158a7f7f624SMasahiro Yamada	help
1159ea149b36SAndi Kleen	  Provide support for injecting machine checks for testing purposes.
1160ea149b36SAndi Kleen	  If you don't know what a machine check is and you don't do kernel
1161ea149b36SAndi Kleen	  QA it is safe to say n.
1162ea149b36SAndi Kleen
11634efc0670SAndi Kleenconfig X86_THERMAL_VECTOR
11644efc0670SAndi Kleen	def_bool y
11655bb38adcSAndi Kleen	depends on X86_MCE_INTEL
11664efc0670SAndi Kleen
116707dc900eSPeter Zijlstrasource "arch/x86/events/Kconfig"
1168e633c65aSKan Liang
11695aef51c3SAndy Lutomirskiconfig X86_LEGACY_VM86
11701e642812SIngo Molnar	bool "Legacy VM86 support"
1171506f1d07SSam Ravnborg	depends on X86_32
1172a7f7f624SMasahiro Yamada	help
11735aef51c3SAndy Lutomirski	  This option allows user programs to put the CPU into V8086
11745aef51c3SAndy Lutomirski	  mode, which is an 80286-era approximation of 16-bit real mode.
11755aef51c3SAndy Lutomirski
11765aef51c3SAndy Lutomirski	  Some very old versions of X and/or vbetool require this option
11775aef51c3SAndy Lutomirski	  for user mode setting.  Similarly, DOSEMU will use it if
11785aef51c3SAndy Lutomirski	  available to accelerate real mode DOS programs.  However, any
11795aef51c3SAndy Lutomirski	  recent version of DOSEMU, X, or vbetool should be fully
11805aef51c3SAndy Lutomirski	  functional even without kernel VM86 support, as they will all
11811e642812SIngo Molnar	  fall back to software emulation. Nevertheless, if you are using
11821e642812SIngo Molnar	  a 16-bit DOS program where 16-bit performance matters, vm86
11831e642812SIngo Molnar	  mode might be faster than emulation and you might want to
11841e642812SIngo Molnar	  enable this option.
11855aef51c3SAndy Lutomirski
11861e642812SIngo Molnar	  Note that any app that works on a 64-bit kernel is unlikely to
11871e642812SIngo Molnar	  need this option, as 64-bit kernels don't, and can't, support
11881e642812SIngo Molnar	  V8086 mode. This option is also unrelated to 16-bit protected
11891e642812SIngo Molnar	  mode and is not needed to run most 16-bit programs under Wine.
11905aef51c3SAndy Lutomirski
11911e642812SIngo Molnar	  Enabling this option increases the complexity of the kernel
11921e642812SIngo Molnar	  and slows down exception handling a tiny bit.
11935aef51c3SAndy Lutomirski
11941e642812SIngo Molnar	  If unsure, say N here.
11955aef51c3SAndy Lutomirski
11965aef51c3SAndy Lutomirskiconfig VM86
11975aef51c3SAndy Lutomirski	bool
11985aef51c3SAndy Lutomirski	default X86_LEGACY_VM86
119934273f41SH. Peter Anvin
120034273f41SH. Peter Anvinconfig X86_16BIT
120134273f41SH. Peter Anvin	bool "Enable support for 16-bit segments" if EXPERT
120234273f41SH. Peter Anvin	default y
1203a5b9e5a2SAndy Lutomirski	depends on MODIFY_LDT_SYSCALL
1204a7f7f624SMasahiro Yamada	help
120534273f41SH. Peter Anvin	  This option is required by programs like Wine to run 16-bit
120634273f41SH. Peter Anvin	  protected mode legacy code on x86 processors.  Disabling
120734273f41SH. Peter Anvin	  this option saves about 300 bytes on i386, or around 6K text
120834273f41SH. Peter Anvin	  plus 16K runtime memory on x86-64,
120934273f41SH. Peter Anvin
121034273f41SH. Peter Anvinconfig X86_ESPFIX32
121134273f41SH. Peter Anvin	def_bool y
121234273f41SH. Peter Anvin	depends on X86_16BIT && X86_32
1213506f1d07SSam Ravnborg
1214197725deSH. Peter Anvinconfig X86_ESPFIX64
1215197725deSH. Peter Anvin	def_bool y
121634273f41SH. Peter Anvin	depends on X86_16BIT && X86_64
1217506f1d07SSam Ravnborg
12181ad83c85SAndy Lutomirskiconfig X86_VSYSCALL_EMULATION
12191ad83c85SAndy Lutomirski	bool "Enable vsyscall emulation" if EXPERT
12201ad83c85SAndy Lutomirski	default y
12211ad83c85SAndy Lutomirski	depends on X86_64
1222a7f7f624SMasahiro Yamada	help
12231ad83c85SAndy Lutomirski	 This enables emulation of the legacy vsyscall page.  Disabling
12241ad83c85SAndy Lutomirski	 it is roughly equivalent to booting with vsyscall=none, except
12251ad83c85SAndy Lutomirski	 that it will also disable the helpful warning if a program
12261ad83c85SAndy Lutomirski	 tries to use a vsyscall.  With this option set to N, offending
12271ad83c85SAndy Lutomirski	 programs will just segfault, citing addresses of the form
12281ad83c85SAndy Lutomirski	 0xffffffffff600?00.
12291ad83c85SAndy Lutomirski
12301ad83c85SAndy Lutomirski	 This option is required by many programs built before 2013, and
12311ad83c85SAndy Lutomirski	 care should be used even with newer programs if set to N.
12321ad83c85SAndy Lutomirski
12331ad83c85SAndy Lutomirski	 Disabling this option saves about 7K of kernel size and
12341ad83c85SAndy Lutomirski	 possibly 4K of additional runtime pagetable memory.
12351ad83c85SAndy Lutomirski
1236111e7b15SThomas Gleixnerconfig X86_IOPL_IOPERM
1237111e7b15SThomas Gleixner	bool "IOPERM and IOPL Emulation"
1238a24ca997SThomas Gleixner	default y
1239a7f7f624SMasahiro Yamada	help
1240111e7b15SThomas Gleixner	  This enables the ioperm() and iopl() syscalls which are necessary
1241111e7b15SThomas Gleixner	  for legacy applications.
1242111e7b15SThomas Gleixner
1243c8137aceSThomas Gleixner	  Legacy IOPL support is an overbroad mechanism which allows user
1244c8137aceSThomas Gleixner	  space aside of accessing all 65536 I/O ports also to disable
1245c8137aceSThomas Gleixner	  interrupts. To gain this access the caller needs CAP_SYS_RAWIO
1246c8137aceSThomas Gleixner	  capabilities and permission from potentially active security
1247c8137aceSThomas Gleixner	  modules.
1248c8137aceSThomas Gleixner
1249c8137aceSThomas Gleixner	  The emulation restricts the functionality of the syscall to
1250c8137aceSThomas Gleixner	  only allowing the full range I/O port access, but prevents the
1251a24ca997SThomas Gleixner	  ability to disable interrupts from user space which would be
1252a24ca997SThomas Gleixner	  granted if the hardware IOPL mechanism would be used.
1253c8137aceSThomas Gleixner
1254506f1d07SSam Ravnborgconfig TOSHIBA
1255506f1d07SSam Ravnborg	tristate "Toshiba Laptop support"
1256506f1d07SSam Ravnborg	depends on X86_32
1257a7f7f624SMasahiro Yamada	help
1258506f1d07SSam Ravnborg	  This adds a driver to safely access the System Management Mode of
1259506f1d07SSam Ravnborg	  the CPU on Toshiba portables with a genuine Toshiba BIOS. It does
1260506f1d07SSam Ravnborg	  not work on models with a Phoenix BIOS. The System Management Mode
1261506f1d07SSam Ravnborg	  is used to set the BIOS and power saving options on Toshiba portables.
1262506f1d07SSam Ravnborg
1263506f1d07SSam Ravnborg	  For information on utilities to make use of this driver see the
1264506f1d07SSam Ravnborg	  Toshiba Linux utilities web site at:
1265506f1d07SSam Ravnborg	  <http://www.buzzard.org.uk/toshiba/>.
1266506f1d07SSam Ravnborg
1267506f1d07SSam Ravnborg	  Say Y if you intend to run this kernel on a Toshiba portable.
1268506f1d07SSam Ravnborg	  Say N otherwise.
1269506f1d07SSam Ravnborg
1270506f1d07SSam Ravnborgconfig I8K
1271039ae585SPali Rohár	tristate "Dell i8k legacy laptop support"
1272949a9d70SJean Delvare	select HWMON
1273039ae585SPali Rohár	select SENSORS_DELL_SMM
1274a7f7f624SMasahiro Yamada	help
1275039ae585SPali Rohár	  This option enables legacy /proc/i8k userspace interface in hwmon
1276039ae585SPali Rohár	  dell-smm-hwmon driver. Character file /proc/i8k reports bios version,
1277039ae585SPali Rohár	  temperature and allows controlling fan speeds of Dell laptops via
1278039ae585SPali Rohár	  System Management Mode. For old Dell laptops (like Dell Inspiron 8000)
1279039ae585SPali Rohár	  it reports also power and hotkey status. For fan speed control is
1280039ae585SPali Rohár	  needed userspace package i8kutils.
1281506f1d07SSam Ravnborg
1282039ae585SPali Rohár	  Say Y if you intend to run this kernel on old Dell laptops or want to
1283039ae585SPali Rohár	  use userspace package i8kutils.
1284506f1d07SSam Ravnborg	  Say N otherwise.
1285506f1d07SSam Ravnborg
1286506f1d07SSam Ravnborgconfig X86_REBOOTFIXUPS
12879ba16087SJan Beulich	bool "Enable X86 board specific fixups for reboot"
12889ba16087SJan Beulich	depends on X86_32
1289a7f7f624SMasahiro Yamada	help
1290506f1d07SSam Ravnborg	  This enables chipset and/or board specific fixups to be done
1291506f1d07SSam Ravnborg	  in order to get reboot to work correctly. This is only needed on
1292506f1d07SSam Ravnborg	  some combinations of hardware and BIOS. The symptom, for which
1293506f1d07SSam Ravnborg	  this config is intended, is when reboot ends with a stalled/hung
1294506f1d07SSam Ravnborg	  system.
1295506f1d07SSam Ravnborg
1296506f1d07SSam Ravnborg	  Currently, the only fixup is for the Geode machines using
12975e3a77e9SFlorian Fainelli	  CS5530A and CS5536 chipsets and the RDC R-321x SoC.
1298506f1d07SSam Ravnborg
1299506f1d07SSam Ravnborg	  Say Y if you want to enable the fixup. Currently, it's safe to
1300506f1d07SSam Ravnborg	  enable this option even if you don't need it.
1301506f1d07SSam Ravnborg	  Say N otherwise.
1302506f1d07SSam Ravnborg
1303506f1d07SSam Ravnborgconfig MICROCODE
13049a2bc335SBorislav Petkov	bool "CPU microcode loading support"
13059a2bc335SBorislav Petkov	default y
130680030e3dSBorislav Petkov	depends on CPU_SUP_AMD || CPU_SUP_INTEL
1307a7f7f624SMasahiro Yamada	help
1308506f1d07SSam Ravnborg	  If you say Y here, you will be able to update the microcode on
13095f9c01aaSBorislav Petkov	  Intel and AMD processors. The Intel support is for the IA32 family,
13105f9c01aaSBorislav Petkov	  e.g. Pentium Pro, Pentium II, Pentium III, Pentium 4, Xeon etc. The
13115f9c01aaSBorislav Petkov	  AMD support is for families 0x10 and later. You will obviously need
13125f9c01aaSBorislav Petkov	  the actual microcode binary data itself which is not shipped with
13135f9c01aaSBorislav Petkov	  the Linux kernel.
1314506f1d07SSam Ravnborg
13155f9c01aaSBorislav Petkov	  The preferred method to load microcode from a detached initrd is described
1316cb1aaebeSMauro Carvalho Chehab	  in Documentation/x86/microcode.rst. For that you need to enable
13175f9c01aaSBorislav Petkov	  CONFIG_BLK_DEV_INITRD in order for the loader to be able to scan the
13185f9c01aaSBorislav Petkov	  initrd for microcode blobs.
1319506f1d07SSam Ravnborg
1320c508c46eSBenjamin Gilbert	  In addition, you can build the microcode into the kernel. For that you
1321c508c46eSBenjamin Gilbert	  need to add the vendor-supplied microcode to the CONFIG_EXTRA_FIRMWARE
1322c508c46eSBenjamin Gilbert	  config option.
1323506f1d07SSam Ravnborg
13248d86f390SPeter Orubaconfig MICROCODE_INTEL
1325e43f6e67SBorislav Petkov	bool "Intel microcode loading support"
13268d86f390SPeter Oruba	depends on MICROCODE
13278d86f390SPeter Oruba	default MICROCODE
1328a7f7f624SMasahiro Yamada	help
13298d86f390SPeter Oruba	  This options enables microcode patch loading support for Intel
13308d86f390SPeter Oruba	  processors.
13318d86f390SPeter Oruba
1332b8989db9SAlan	  For the current Intel microcode data package go to
1333b8989db9SAlan	  <https://downloadcenter.intel.com> and search for
1334b8989db9SAlan	  'Linux Processor Microcode Data File'.
13358d86f390SPeter Oruba
133680cc9f10SPeter Orubaconfig MICROCODE_AMD
1337e43f6e67SBorislav Petkov	bool "AMD microcode loading support"
133880cc9f10SPeter Oruba	depends on MICROCODE
1339a7f7f624SMasahiro Yamada	help
134080cc9f10SPeter Oruba	  If you select this option, microcode patch loading support for AMD
134180cc9f10SPeter Oruba	  processors will be enabled.
134280cc9f10SPeter Oruba
1343506f1d07SSam Ravnborgconfig MICROCODE_OLD_INTERFACE
1344c02f48e0SBorislav Petkov	bool "Ancient loading interface (DEPRECATED)"
1345c02f48e0SBorislav Petkov	default n
1346506f1d07SSam Ravnborg	depends on MICROCODE
1347a7f7f624SMasahiro Yamada	help
1348c02f48e0SBorislav Petkov	  DO NOT USE THIS! This is the ancient /dev/cpu/microcode interface
1349c02f48e0SBorislav Petkov	  which was used by userspace tools like iucode_tool and microcode.ctl.
1350c02f48e0SBorislav Petkov	  It is inadequate because it runs too late to be able to properly
1351c02f48e0SBorislav Petkov	  load microcode on a machine and it needs special tools. Instead, you
1352c02f48e0SBorislav Petkov	  should've switched to the early loading method with the initrd or
1353cb1aaebeSMauro Carvalho Chehab	  builtin microcode by now: Documentation/x86/microcode.rst
1354506f1d07SSam Ravnborg
1355506f1d07SSam Ravnborgconfig X86_MSR
1356506f1d07SSam Ravnborg	tristate "/dev/cpu/*/msr - Model-specific register support"
1357a7f7f624SMasahiro Yamada	help
1358506f1d07SSam Ravnborg	  This device gives privileged processes access to the x86
1359506f1d07SSam Ravnborg	  Model-Specific Registers (MSRs).  It is a character device with
1360506f1d07SSam Ravnborg	  major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr.
1361506f1d07SSam Ravnborg	  MSR accesses are directed to a specific CPU on multi-processor
1362506f1d07SSam Ravnborg	  systems.
1363506f1d07SSam Ravnborg
1364506f1d07SSam Ravnborgconfig X86_CPUID
1365506f1d07SSam Ravnborg	tristate "/dev/cpu/*/cpuid - CPU information support"
1366a7f7f624SMasahiro Yamada	help
1367506f1d07SSam Ravnborg	  This device gives processes access to the x86 CPUID instruction to
1368506f1d07SSam Ravnborg	  be executed on a specific processor.  It is a character device
1369506f1d07SSam Ravnborg	  with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to
1370506f1d07SSam Ravnborg	  /dev/cpu/31/cpuid.
1371506f1d07SSam Ravnborg
1372506f1d07SSam Ravnborgchoice
1373506f1d07SSam Ravnborg	prompt "High Memory Support"
13746fc108a0SJan Beulich	default HIGHMEM4G
1375506f1d07SSam Ravnborg	depends on X86_32
1376506f1d07SSam Ravnborg
1377506f1d07SSam Ravnborgconfig NOHIGHMEM
1378506f1d07SSam Ravnborg	bool "off"
1379a7f7f624SMasahiro Yamada	help
1380506f1d07SSam Ravnborg	  Linux can use up to 64 Gigabytes of physical memory on x86 systems.
1381506f1d07SSam Ravnborg	  However, the address space of 32-bit x86 processors is only 4
1382506f1d07SSam Ravnborg	  Gigabytes large. That means that, if you have a large amount of
1383506f1d07SSam Ravnborg	  physical memory, not all of it can be "permanently mapped" by the
1384506f1d07SSam Ravnborg	  kernel. The physical memory that's not permanently mapped is called
1385506f1d07SSam Ravnborg	  "high memory".
1386506f1d07SSam Ravnborg
1387506f1d07SSam Ravnborg	  If you are compiling a kernel which will never run on a machine with
1388506f1d07SSam Ravnborg	  more than 1 Gigabyte total physical RAM, answer "off" here (default
1389506f1d07SSam Ravnborg	  choice and suitable for most users). This will result in a "3GB/1GB"
1390506f1d07SSam Ravnborg	  split: 3GB are mapped so that each process sees a 3GB virtual memory
1391506f1d07SSam Ravnborg	  space and the remaining part of the 4GB virtual memory space is used
1392506f1d07SSam Ravnborg	  by the kernel to permanently map as much physical memory as
1393506f1d07SSam Ravnborg	  possible.
1394506f1d07SSam Ravnborg
1395506f1d07SSam Ravnborg	  If the machine has between 1 and 4 Gigabytes physical RAM, then
1396506f1d07SSam Ravnborg	  answer "4GB" here.
1397506f1d07SSam Ravnborg
1398506f1d07SSam Ravnborg	  If more than 4 Gigabytes is used then answer "64GB" here. This
1399506f1d07SSam Ravnborg	  selection turns Intel PAE (Physical Address Extension) mode on.
1400506f1d07SSam Ravnborg	  PAE implements 3-level paging on IA32 processors. PAE is fully
1401506f1d07SSam Ravnborg	  supported by Linux, PAE mode is implemented on all recent Intel
1402506f1d07SSam Ravnborg	  processors (Pentium Pro and better). NOTE: If you say "64GB" here,
1403506f1d07SSam Ravnborg	  then the kernel will not boot on CPUs that don't support PAE!
1404506f1d07SSam Ravnborg
1405506f1d07SSam Ravnborg	  The actual amount of total physical memory will either be
1406506f1d07SSam Ravnborg	  auto detected or can be forced by using a kernel command line option
1407506f1d07SSam Ravnborg	  such as "mem=256M". (Try "man bootparam" or see the documentation of
1408506f1d07SSam Ravnborg	  your boot loader (lilo or loadlin) about how to pass options to the
1409506f1d07SSam Ravnborg	  kernel at boot time.)
1410506f1d07SSam Ravnborg
1411506f1d07SSam Ravnborg	  If unsure, say "off".
1412506f1d07SSam Ravnborg
1413506f1d07SSam Ravnborgconfig HIGHMEM4G
1414506f1d07SSam Ravnborg	bool "4GB"
1415a7f7f624SMasahiro Yamada	help
1416506f1d07SSam Ravnborg	  Select this if you have a 32-bit processor and between 1 and 4
1417506f1d07SSam Ravnborg	  gigabytes of physical RAM.
1418506f1d07SSam Ravnborg
1419506f1d07SSam Ravnborgconfig HIGHMEM64G
1420506f1d07SSam Ravnborg	bool "64GB"
142169b8d3fcSMatthew Whitehead	depends on !M486 && !M586 && !M586TSC && !M586MMX && !MGEODE_LX && !MGEODEGX1 && !MCYRIXIII && !MELAN && !MWINCHIPC6 && !WINCHIP3D && !MK6
1422506f1d07SSam Ravnborg	select X86_PAE
1423a7f7f624SMasahiro Yamada	help
1424506f1d07SSam Ravnborg	  Select this if you have a 32-bit processor and more than 4
1425506f1d07SSam Ravnborg	  gigabytes of physical RAM.
1426506f1d07SSam Ravnborg
1427506f1d07SSam Ravnborgendchoice
1428506f1d07SSam Ravnborg
1429506f1d07SSam Ravnborgchoice
14306a108a14SDavid Rientjes	prompt "Memory split" if EXPERT
1431506f1d07SSam Ravnborg	default VMSPLIT_3G
1432506f1d07SSam Ravnborg	depends on X86_32
1433a7f7f624SMasahiro Yamada	help
1434506f1d07SSam Ravnborg	  Select the desired split between kernel and user memory.
1435506f1d07SSam Ravnborg
1436506f1d07SSam Ravnborg	  If the address range available to the kernel is less than the
1437506f1d07SSam Ravnborg	  physical memory installed, the remaining memory will be available
1438506f1d07SSam Ravnborg	  as "high memory". Accessing high memory is a little more costly
1439506f1d07SSam Ravnborg	  than low memory, as it needs to be mapped into the kernel first.
1440506f1d07SSam Ravnborg	  Note that increasing the kernel address space limits the range
1441506f1d07SSam Ravnborg	  available to user programs, making the address space there
1442506f1d07SSam Ravnborg	  tighter.  Selecting anything other than the default 3G/1G split
1443506f1d07SSam Ravnborg	  will also likely make your kernel incompatible with binary-only
1444506f1d07SSam Ravnborg	  kernel modules.
1445506f1d07SSam Ravnborg
1446506f1d07SSam Ravnborg	  If you are not absolutely sure what you are doing, leave this
1447506f1d07SSam Ravnborg	  option alone!
1448506f1d07SSam Ravnborg
1449506f1d07SSam Ravnborg	config VMSPLIT_3G
1450506f1d07SSam Ravnborg		bool "3G/1G user/kernel split"
1451506f1d07SSam Ravnborg	config VMSPLIT_3G_OPT
1452506f1d07SSam Ravnborg		depends on !X86_PAE
1453506f1d07SSam Ravnborg		bool "3G/1G user/kernel split (for full 1G low memory)"
1454506f1d07SSam Ravnborg	config VMSPLIT_2G
1455506f1d07SSam Ravnborg		bool "2G/2G user/kernel split"
1456506f1d07SSam Ravnborg	config VMSPLIT_2G_OPT
1457506f1d07SSam Ravnborg		depends on !X86_PAE
1458506f1d07SSam Ravnborg		bool "2G/2G user/kernel split (for full 2G low memory)"
1459506f1d07SSam Ravnborg	config VMSPLIT_1G
1460506f1d07SSam Ravnborg		bool "1G/3G user/kernel split"
1461506f1d07SSam Ravnborgendchoice
1462506f1d07SSam Ravnborg
1463506f1d07SSam Ravnborgconfig PAGE_OFFSET
1464506f1d07SSam Ravnborg	hex
1465506f1d07SSam Ravnborg	default 0xB0000000 if VMSPLIT_3G_OPT
1466506f1d07SSam Ravnborg	default 0x80000000 if VMSPLIT_2G
1467506f1d07SSam Ravnborg	default 0x78000000 if VMSPLIT_2G_OPT
1468506f1d07SSam Ravnborg	default 0x40000000 if VMSPLIT_1G
1469506f1d07SSam Ravnborg	default 0xC0000000
1470506f1d07SSam Ravnborg	depends on X86_32
1471506f1d07SSam Ravnborg
1472506f1d07SSam Ravnborgconfig HIGHMEM
14733c2362e6SHarvey Harrison	def_bool y
1474506f1d07SSam Ravnborg	depends on X86_32 && (HIGHMEM64G || HIGHMEM4G)
1475506f1d07SSam Ravnborg
1476506f1d07SSam Ravnborgconfig X86_PAE
14779ba16087SJan Beulich	bool "PAE (Physical Address Extension) Support"
1478506f1d07SSam Ravnborg	depends on X86_32 && !HIGHMEM4G
1479d4a451d5SChristoph Hellwig	select PHYS_ADDR_T_64BIT
14809d99c712SChristian Melki	select SWIOTLB
1481a7f7f624SMasahiro Yamada	help
1482506f1d07SSam Ravnborg	  PAE is required for NX support, and furthermore enables
1483506f1d07SSam Ravnborg	  larger swapspace support for non-overcommit purposes. It
1484506f1d07SSam Ravnborg	  has the cost of more pagetable lookup overhead, and also
1485506f1d07SSam Ravnborg	  consumes more pagetable space per process.
1486506f1d07SSam Ravnborg
148777ef56e4SKirill A. Shutemovconfig X86_5LEVEL
148877ef56e4SKirill A. Shutemov	bool "Enable 5-level page tables support"
148918ec1eafSKirill A. Shutemov	default y
1490eedb92abSKirill A. Shutemov	select DYNAMIC_MEMORY_LAYOUT
1491162434e7SKirill A. Shutemov	select SPARSEMEM_VMEMMAP
149277ef56e4SKirill A. Shutemov	depends on X86_64
1493a7f7f624SMasahiro Yamada	help
149477ef56e4SKirill A. Shutemov	  5-level paging enables access to larger address space:
149577ef56e4SKirill A. Shutemov	  upto 128 PiB of virtual address space and 4 PiB of
149677ef56e4SKirill A. Shutemov	  physical address space.
149777ef56e4SKirill A. Shutemov
149877ef56e4SKirill A. Shutemov	  It will be supported by future Intel CPUs.
149977ef56e4SKirill A. Shutemov
15006657fca0SKirill A. Shutemov	  A kernel with the option enabled can be booted on machines that
15016657fca0SKirill A. Shutemov	  support 4- or 5-level paging.
150277ef56e4SKirill A. Shutemov
1503cb1aaebeSMauro Carvalho Chehab	  See Documentation/x86/x86_64/5level-paging.rst for more
150477ef56e4SKirill A. Shutemov	  information.
150577ef56e4SKirill A. Shutemov
150677ef56e4SKirill A. Shutemov	  Say N if unsure.
150777ef56e4SKirill A. Shutemov
150810971ab2SIngo Molnarconfig X86_DIRECT_GBPAGES
1509e5008abeSLuis R. Rodriguez	def_bool y
15102e1da13fSVlastimil Babka	depends on X86_64
1511a7f7f624SMasahiro Yamada	help
151210971ab2SIngo Molnar	  Certain kernel features effectively disable kernel
151310971ab2SIngo Molnar	  linear 1 GB mappings (even if the CPU otherwise
151410971ab2SIngo Molnar	  supports them), so don't confuse the user by printing
151510971ab2SIngo Molnar	  that we have them enabled.
15169e899816SNick Piggin
15175c280cf6SThomas Gleixnerconfig X86_CPA_STATISTICS
15185c280cf6SThomas Gleixner	bool "Enable statistic for Change Page Attribute"
15195c280cf6SThomas Gleixner	depends on DEBUG_FS
1520a7f7f624SMasahiro Yamada	help
1521b75baaf3SIngo Molnar	  Expose statistics about the Change Page Attribute mechanism, which
1522a943245aSColin Ian King	  helps to determine the effectiveness of preserving large and huge
15235c280cf6SThomas Gleixner	  page mappings when mapping protections are changed.
15245c280cf6SThomas Gleixner
15257744ccdbSTom Lendackyconfig AMD_MEM_ENCRYPT
15267744ccdbSTom Lendacky	bool "AMD Secure Memory Encryption (SME) support"
15277744ccdbSTom Lendacky	depends on X86_64 && CPU_SUP_AMD
152882fef0adSDavid Rientjes	select DMA_COHERENT_POOL
152994d49eb3SKirill A. Shutemov	select DYNAMIC_PHYSICAL_MASK
1530ce9084baSArd Biesheuvel	select ARCH_USE_MEMREMAP_PROT
15319087c375STom Lendacky	select ARCH_HAS_FORCE_DMA_UNENCRYPTED
1532597cfe48SJoerg Roedel	select INSTRUCTION_DECODER
1533a7f7f624SMasahiro Yamada	help
15347744ccdbSTom Lendacky	  Say yes to enable support for the encryption of system memory.
15357744ccdbSTom Lendacky	  This requires an AMD processor that supports Secure Memory
15367744ccdbSTom Lendacky	  Encryption (SME).
15377744ccdbSTom Lendacky
15387744ccdbSTom Lendackyconfig AMD_MEM_ENCRYPT_ACTIVE_BY_DEFAULT
15397744ccdbSTom Lendacky	bool "Activate AMD Secure Memory Encryption (SME) by default"
15407744ccdbSTom Lendacky	default y
15417744ccdbSTom Lendacky	depends on AMD_MEM_ENCRYPT
1542a7f7f624SMasahiro Yamada	help
15437744ccdbSTom Lendacky	  Say yes to have system memory encrypted by default if running on
15447744ccdbSTom Lendacky	  an AMD processor that supports Secure Memory Encryption (SME).
15457744ccdbSTom Lendacky
15467744ccdbSTom Lendacky	  If set to Y, then the encryption of system memory can be
15477744ccdbSTom Lendacky	  deactivated with the mem_encrypt=off command line option.
15487744ccdbSTom Lendacky
15497744ccdbSTom Lendacky	  If set to N, then the encryption of system memory can be
15507744ccdbSTom Lendacky	  activated with the mem_encrypt=on command line option.
15517744ccdbSTom Lendacky
1552506f1d07SSam Ravnborg# Common NUMA Features
1553506f1d07SSam Ravnborgconfig NUMA
1554e133f6eaSRandy Dunlap	bool "NUMA Memory Allocation and Scheduler Support"
1555506f1d07SSam Ravnborg	depends on SMP
1556b5660ba7SH. Peter Anvin	depends on X86_64 || (X86_32 && HIGHMEM64G && X86_BIGSMP)
1557b5660ba7SH. Peter Anvin	default y if X86_BIGSMP
1558a7f7f624SMasahiro Yamada	help
1559e133f6eaSRandy Dunlap	  Enable NUMA (Non-Uniform Memory Access) support.
1560fd51b2d7SKOSAKI Motohiro
1561506f1d07SSam Ravnborg	  The kernel will try to allocate memory used by a CPU on the
1562506f1d07SSam Ravnborg	  local memory controller of the CPU and add some more
1563506f1d07SSam Ravnborg	  NUMA awareness to the kernel.
1564506f1d07SSam Ravnborg
1565c280ea5eSIngo Molnar	  For 64-bit this is recommended if the system is Intel Core i7
1566fd51b2d7SKOSAKI Motohiro	  (or later), AMD Opteron, or EM64T NUMA.
1567fd51b2d7SKOSAKI Motohiro
1568b5660ba7SH. Peter Anvin	  For 32-bit this is only needed if you boot a 32-bit
15697cf6c945SDavid Rientjes	  kernel on a 64-bit NUMA platform.
1570fd51b2d7SKOSAKI Motohiro
1571fd51b2d7SKOSAKI Motohiro	  Otherwise, you should say N.
1572506f1d07SSam Ravnborg
1573eec1d4faSHans Rosenfeldconfig AMD_NUMA
15743c2362e6SHarvey Harrison	def_bool y
15753c2362e6SHarvey Harrison	prompt "Old style AMD Opteron NUMA detection"
15765da0ef9aSTejun Heo	depends on X86_64 && NUMA && PCI
1577a7f7f624SMasahiro Yamada	help
1578eec1d4faSHans Rosenfeld	  Enable AMD NUMA node topology detection.  You should say Y here if
1579eec1d4faSHans Rosenfeld	  you have a multi processor AMD system. This uses an old method to
1580eec1d4faSHans Rosenfeld	  read the NUMA configuration directly from the builtin Northbridge
1581eec1d4faSHans Rosenfeld	  of Opteron. It is recommended to use X86_64_ACPI_NUMA instead,
1582eec1d4faSHans Rosenfeld	  which also takes priority if both are compiled in.
1583506f1d07SSam Ravnborg
1584506f1d07SSam Ravnborgconfig X86_64_ACPI_NUMA
15853c2362e6SHarvey Harrison	def_bool y
15863c2362e6SHarvey Harrison	prompt "ACPI NUMA detection"
1587506f1d07SSam Ravnborg	depends on X86_64 && NUMA && ACPI && PCI
1588506f1d07SSam Ravnborg	select ACPI_NUMA
1589a7f7f624SMasahiro Yamada	help
1590506f1d07SSam Ravnborg	  Enable ACPI SRAT based node topology detection.
1591506f1d07SSam Ravnborg
1592506f1d07SSam Ravnborgconfig NUMA_EMU
1593506f1d07SSam Ravnborg	bool "NUMA emulation"
15941b7e03efSTejun Heo	depends on NUMA
1595a7f7f624SMasahiro Yamada	help
1596506f1d07SSam Ravnborg	  Enable NUMA emulation. A flat machine will be split
1597506f1d07SSam Ravnborg	  into virtual nodes when booted with "numa=fake=N", where N is the
1598506f1d07SSam Ravnborg	  number of nodes. This is only useful for debugging.
1599506f1d07SSam Ravnborg
1600506f1d07SSam Ravnborgconfig NODES_SHIFT
1601d25e26b6SLinus Torvalds	int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP
160251591e31SDavid Rientjes	range 1 10
160351591e31SDavid Rientjes	default "10" if MAXSMP
1604506f1d07SSam Ravnborg	default "6" if X86_64
1605506f1d07SSam Ravnborg	default "3"
1606506f1d07SSam Ravnborg	depends on NEED_MULTIPLE_NODES
1607a7f7f624SMasahiro Yamada	help
16081184dc2fSMike Travis	  Specify the maximum number of NUMA Nodes available on the target
1609692105b8SMatt LaPlante	  system.  Increases memory reserved to accommodate various tables.
1610506f1d07SSam Ravnborg
1611506f1d07SSam Ravnborgconfig ARCH_FLATMEM_ENABLE
1612506f1d07SSam Ravnborg	def_bool y
16133b16651fSTejun Heo	depends on X86_32 && !NUMA
1614506f1d07SSam Ravnborg
1615506f1d07SSam Ravnborgconfig ARCH_SPARSEMEM_ENABLE
1616506f1d07SSam Ravnborg	def_bool y
16176ea30386SKees Cook	depends on X86_64 || NUMA || X86_32 || X86_32_NON_STANDARD
1618506f1d07SSam Ravnborg	select SPARSEMEM_STATIC if X86_32
1619506f1d07SSam Ravnborg	select SPARSEMEM_VMEMMAP_ENABLE if X86_64
1620506f1d07SSam Ravnborg
16213b16651fSTejun Heoconfig ARCH_SPARSEMEM_DEFAULT
16226ad57f7fSMike Rapoport	def_bool X86_64 || (NUMA && X86_32)
16233b16651fSTejun Heo
1624506f1d07SSam Ravnborgconfig ARCH_SELECT_MEMORY_MODEL
1625506f1d07SSam Ravnborg	def_bool y
1626b263295dSChristoph Lameter	depends on ARCH_SPARSEMEM_ENABLE
1627506f1d07SSam Ravnborg
1628506f1d07SSam Ravnborgconfig ARCH_MEMORY_PROBE
1629a0842b70SToshi Kani	bool "Enable sysfs memory/probe interface"
16303120e25eSJan Beulich	depends on X86_64 && MEMORY_HOTPLUG
1631a0842b70SToshi Kani	help
1632a0842b70SToshi Kani	  This option enables a sysfs memory/probe interface for testing.
1633cb1aaebeSMauro Carvalho Chehab	  See Documentation/admin-guide/mm/memory-hotplug.rst for more information.
1634a0842b70SToshi Kani	  If you are unsure how to answer this question, answer N.
1635506f1d07SSam Ravnborg
16363b16651fSTejun Heoconfig ARCH_PROC_KCORE_TEXT
16373b16651fSTejun Heo	def_bool y
16383b16651fSTejun Heo	depends on X86_64 && PROC_KCORE
16393b16651fSTejun Heo
1640a29815a3SAvi Kivityconfig ILLEGAL_POINTER_VALUE
1641a29815a3SAvi Kivity	hex
1642a29815a3SAvi Kivity	default 0 if X86_32
1643a29815a3SAvi Kivity	default 0xdead000000000000 if X86_64
1644a29815a3SAvi Kivity
16457a67832cSDan Williamsconfig X86_PMEM_LEGACY_DEVICE
16467a67832cSDan Williams	bool
16477a67832cSDan Williams
1648ec776ef6SChristoph Hellwigconfig X86_PMEM_LEGACY
16497a67832cSDan Williams	tristate "Support non-standard NVDIMMs and ADR protected memory"
16509f53f9faSDan Williams	depends on PHYS_ADDR_T_64BIT
16519f53f9faSDan Williams	depends on BLK_DEV
16527a67832cSDan Williams	select X86_PMEM_LEGACY_DEVICE
16537b27a862SDan Williams	select NUMA_KEEP_MEMINFO if NUMA
16549f53f9faSDan Williams	select LIBNVDIMM
1655ec776ef6SChristoph Hellwig	help
1656ec776ef6SChristoph Hellwig	  Treat memory marked using the non-standard e820 type of 12 as used
1657ec776ef6SChristoph Hellwig	  by the Intel Sandy Bridge-EP reference BIOS as protected memory.
1658ec776ef6SChristoph Hellwig	  The kernel will offer these regions to the 'pmem' driver so
1659ec776ef6SChristoph Hellwig	  they can be used for persistent storage.
1660ec776ef6SChristoph Hellwig
1661ec776ef6SChristoph Hellwig	  Say Y if unsure.
1662ec776ef6SChristoph Hellwig
1663506f1d07SSam Ravnborgconfig HIGHPTE
1664506f1d07SSam Ravnborg	bool "Allocate 3rd-level pagetables from highmem"
16656fc108a0SJan Beulich	depends on HIGHMEM
1666a7f7f624SMasahiro Yamada	help
1667506f1d07SSam Ravnborg	  The VM uses one page table entry for each page of physical memory.
1668506f1d07SSam Ravnborg	  For systems with a lot of RAM, this can be wasteful of precious
1669506f1d07SSam Ravnborg	  low memory.  Setting this option will put user-space page table
1670506f1d07SSam Ravnborg	  entries in high memory.
1671506f1d07SSam Ravnborg
16729f077871SJeremy Fitzhardingeconfig X86_CHECK_BIOS_CORRUPTION
16739f077871SJeremy Fitzhardinge	bool "Check for low memory corruption"
1674a7f7f624SMasahiro Yamada	help
16759f077871SJeremy Fitzhardinge	  Periodically check for memory corruption in low memory, which
16769f077871SJeremy Fitzhardinge	  is suspected to be caused by BIOS.  Even when enabled in the
16779f077871SJeremy Fitzhardinge	  configuration, it is disabled at runtime.  Enable it by
16789f077871SJeremy Fitzhardinge	  setting "memory_corruption_check=1" on the kernel command
16799f077871SJeremy Fitzhardinge	  line.  By default it scans the low 64k of memory every 60
16809f077871SJeremy Fitzhardinge	  seconds; see the memory_corruption_check_size and
16819f077871SJeremy Fitzhardinge	  memory_corruption_check_period parameters in
16828c27ceffSMauro Carvalho Chehab	  Documentation/admin-guide/kernel-parameters.rst to adjust this.
16839f077871SJeremy Fitzhardinge
16849f077871SJeremy Fitzhardinge	  When enabled with the default parameters, this option has
16859f077871SJeremy Fitzhardinge	  almost no overhead, as it reserves a relatively small amount
16869f077871SJeremy Fitzhardinge	  of memory and scans it infrequently.  It both detects corruption
16879f077871SJeremy Fitzhardinge	  and prevents it from affecting the running system.
16889f077871SJeremy Fitzhardinge
16899f077871SJeremy Fitzhardinge	  It is, however, intended as a diagnostic tool; if repeatable
16909f077871SJeremy Fitzhardinge	  BIOS-originated corruption always affects the same memory,
16919f077871SJeremy Fitzhardinge	  you can use memmap= to prevent the kernel from using that
16929f077871SJeremy Fitzhardinge	  memory.
16939f077871SJeremy Fitzhardinge
1694c885df50SJeremy Fitzhardingeconfig X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK
1695c885df50SJeremy Fitzhardinge	bool "Set the default setting of memory_corruption_check"
1696c885df50SJeremy Fitzhardinge	depends on X86_CHECK_BIOS_CORRUPTION
1697c885df50SJeremy Fitzhardinge	default y
1698a7f7f624SMasahiro Yamada	help
1699c885df50SJeremy Fitzhardinge	  Set whether the default state of memory_corruption_check is
1700c885df50SJeremy Fitzhardinge	  on or off.
1701c885df50SJeremy Fitzhardinge
17029ea77bdbSH. Peter Anvinconfig X86_RESERVE_LOW
1703d0cd7425SH. Peter Anvin	int "Amount of low memory, in kilobytes, to reserve for the BIOS"
1704d0cd7425SH. Peter Anvin	default 64
1705d0cd7425SH. Peter Anvin	range 4 640
1706a7f7f624SMasahiro Yamada	help
1707d0cd7425SH. Peter Anvin	  Specify the amount of low memory to reserve for the BIOS.
1708fc381519SIngo Molnar
1709d0cd7425SH. Peter Anvin	  The first page contains BIOS data structures that the kernel
1710d0cd7425SH. Peter Anvin	  must not use, so that page must always be reserved.
1711fc381519SIngo Molnar
1712d0cd7425SH. Peter Anvin	  By default we reserve the first 64K of physical RAM, as a
1713d0cd7425SH. Peter Anvin	  number of BIOSes are known to corrupt that memory range
1714d0cd7425SH. Peter Anvin	  during events such as suspend/resume or monitor cable
1715d0cd7425SH. Peter Anvin	  insertion, so it must not be used by the kernel.
1716fc381519SIngo Molnar
1717d0cd7425SH. Peter Anvin	  You can set this to 4 if you are absolutely sure that you
1718d0cd7425SH. Peter Anvin	  trust the BIOS to get all its memory reservations and usages
1719d0cd7425SH. Peter Anvin	  right.  If you know your BIOS have problems beyond the
1720d0cd7425SH. Peter Anvin	  default 64K area, you can set this to 640 to avoid using the
1721d0cd7425SH. Peter Anvin	  entire low memory range.
1722d0cd7425SH. Peter Anvin
1723d0cd7425SH. Peter Anvin	  If you have doubts about the BIOS (e.g. suspend/resume does
1724d0cd7425SH. Peter Anvin	  not work or there's kernel crashes after certain hardware
1725d0cd7425SH. Peter Anvin	  hotplug events) then you might want to enable
1726d0cd7425SH. Peter Anvin	  X86_CHECK_BIOS_CORRUPTION=y to allow the kernel to check
1727d0cd7425SH. Peter Anvin	  typical corruption patterns.
1728d0cd7425SH. Peter Anvin
1729d0cd7425SH. Peter Anvin	  Leave this to the default value of 64 if you are unsure.
1730fc381519SIngo Molnar
1731506f1d07SSam Ravnborgconfig MATH_EMULATION
1732506f1d07SSam Ravnborg	bool
1733a5b9e5a2SAndy Lutomirski	depends on MODIFY_LDT_SYSCALL
173487d6021bSArnd Bergmann	prompt "Math emulation" if X86_32 && (M486SX || MELAN)
1735a7f7f624SMasahiro Yamada	help
1736506f1d07SSam Ravnborg	  Linux can emulate a math coprocessor (used for floating point
1737506f1d07SSam Ravnborg	  operations) if you don't have one. 486DX and Pentium processors have
1738506f1d07SSam Ravnborg	  a math coprocessor built in, 486SX and 386 do not, unless you added
1739506f1d07SSam Ravnborg	  a 487DX or 387, respectively. (The messages during boot time can
1740506f1d07SSam Ravnborg	  give you some hints here ["man dmesg"].) Everyone needs either a
1741506f1d07SSam Ravnborg	  coprocessor or this emulation.
1742506f1d07SSam Ravnborg
1743506f1d07SSam Ravnborg	  If you don't have a math coprocessor, you need to say Y here; if you
1744506f1d07SSam Ravnborg	  say Y here even though you have a coprocessor, the coprocessor will
1745506f1d07SSam Ravnborg	  be used nevertheless. (This behavior can be changed with the kernel
1746506f1d07SSam Ravnborg	  command line option "no387", which comes handy if your coprocessor
1747506f1d07SSam Ravnborg	  is broken. Try "man bootparam" or see the documentation of your boot
1748506f1d07SSam Ravnborg	  loader (lilo or loadlin) about how to pass options to the kernel at
1749506f1d07SSam Ravnborg	  boot time.) This means that it is a good idea to say Y here if you
1750506f1d07SSam Ravnborg	  intend to use this kernel on different machines.
1751506f1d07SSam Ravnborg
1752506f1d07SSam Ravnborg	  More information about the internals of the Linux math coprocessor
1753506f1d07SSam Ravnborg	  emulation can be found in <file:arch/x86/math-emu/README>.
1754506f1d07SSam Ravnborg
1755506f1d07SSam Ravnborg	  If you are not sure, say Y; apart from resulting in a 66 KB bigger
1756506f1d07SSam Ravnborg	  kernel, it won't hurt.
1757506f1d07SSam Ravnborg
1758506f1d07SSam Ravnborgconfig MTRR
17596fc108a0SJan Beulich	def_bool y
17606a108a14SDavid Rientjes	prompt "MTRR (Memory Type Range Register) support" if EXPERT
1761a7f7f624SMasahiro Yamada	help
1762506f1d07SSam Ravnborg	  On Intel P6 family processors (Pentium Pro, Pentium II and later)
1763506f1d07SSam Ravnborg	  the Memory Type Range Registers (MTRRs) may be used to control
1764506f1d07SSam Ravnborg	  processor access to memory ranges. This is most useful if you have
1765506f1d07SSam Ravnborg	  a video (VGA) card on a PCI or AGP bus. Enabling write-combining
1766506f1d07SSam Ravnborg	  allows bus write transfers to be combined into a larger transfer
1767506f1d07SSam Ravnborg	  before bursting over the PCI/AGP bus. This can increase performance
1768506f1d07SSam Ravnborg	  of image write operations 2.5 times or more. Saying Y here creates a
1769506f1d07SSam Ravnborg	  /proc/mtrr file which may be used to manipulate your processor's
1770506f1d07SSam Ravnborg	  MTRRs. Typically the X server should use this.
1771506f1d07SSam Ravnborg
1772506f1d07SSam Ravnborg	  This code has a reasonably generic interface so that similar
1773506f1d07SSam Ravnborg	  control registers on other processors can be easily supported
1774506f1d07SSam Ravnborg	  as well:
1775506f1d07SSam Ravnborg
1776506f1d07SSam Ravnborg	  The Cyrix 6x86, 6x86MX and M II processors have Address Range
1777506f1d07SSam Ravnborg	  Registers (ARRs) which provide a similar functionality to MTRRs. For
1778506f1d07SSam Ravnborg	  these, the ARRs are used to emulate the MTRRs.
1779506f1d07SSam Ravnborg	  The AMD K6-2 (stepping 8 and above) and K6-3 processors have two
1780506f1d07SSam Ravnborg	  MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing
1781506f1d07SSam Ravnborg	  write-combining. All of these processors are supported by this code
1782506f1d07SSam Ravnborg	  and it makes sense to say Y here if you have one of them.
1783506f1d07SSam Ravnborg
1784506f1d07SSam Ravnborg	  Saying Y here also fixes a problem with buggy SMP BIOSes which only
1785506f1d07SSam Ravnborg	  set the MTRRs for the boot CPU and not for the secondary CPUs. This
1786506f1d07SSam Ravnborg	  can lead to all sorts of problems, so it's good to say Y here.
1787506f1d07SSam Ravnborg
1788506f1d07SSam Ravnborg	  You can safely say Y even if your machine doesn't have MTRRs, you'll
1789506f1d07SSam Ravnborg	  just add about 9 KB to your kernel.
1790506f1d07SSam Ravnborg
1791cb1aaebeSMauro Carvalho Chehab	  See <file:Documentation/x86/mtrr.rst> for more information.
1792506f1d07SSam Ravnborg
179395ffa243SYinghai Luconfig MTRR_SANITIZER
17942ffb3501SYinghai Lu	def_bool y
179595ffa243SYinghai Lu	prompt "MTRR cleanup support"
179695ffa243SYinghai Lu	depends on MTRR
1797a7f7f624SMasahiro Yamada	help
1798aba3728cSThomas Gleixner	  Convert MTRR layout from continuous to discrete, so X drivers can
1799aba3728cSThomas Gleixner	  add writeback entries.
180095ffa243SYinghai Lu
1801aba3728cSThomas Gleixner	  Can be disabled with disable_mtrr_cleanup on the kernel command line.
1802692105b8SMatt LaPlante	  The largest mtrr entry size for a continuous block can be set with
1803aba3728cSThomas Gleixner	  mtrr_chunk_size.
180495ffa243SYinghai Lu
18052ffb3501SYinghai Lu	  If unsure, say Y.
180695ffa243SYinghai Lu
180795ffa243SYinghai Luconfig MTRR_SANITIZER_ENABLE_DEFAULT
1808f5098d62SYinghai Lu	int "MTRR cleanup enable value (0-1)"
1809f5098d62SYinghai Lu	range 0 1
1810f5098d62SYinghai Lu	default "0"
181195ffa243SYinghai Lu	depends on MTRR_SANITIZER
1812a7f7f624SMasahiro Yamada	help
1813f5098d62SYinghai Lu	  Enable mtrr cleanup default value
181495ffa243SYinghai Lu
181512031a62SYinghai Luconfig MTRR_SANITIZER_SPARE_REG_NR_DEFAULT
181612031a62SYinghai Lu	int "MTRR cleanup spare reg num (0-7)"
181712031a62SYinghai Lu	range 0 7
181812031a62SYinghai Lu	default "1"
181912031a62SYinghai Lu	depends on MTRR_SANITIZER
1820a7f7f624SMasahiro Yamada	help
182112031a62SYinghai Lu	  mtrr cleanup spare entries default, it can be changed via
1822aba3728cSThomas Gleixner	  mtrr_spare_reg_nr=N on the kernel command line.
182312031a62SYinghai Lu
18242e5d9c85Svenkatesh.pallipadi@intel.comconfig X86_PAT
18256fc108a0SJan Beulich	def_bool y
18266a108a14SDavid Rientjes	prompt "x86 PAT support" if EXPERT
18272a8a2719SIngo Molnar	depends on MTRR
1828a7f7f624SMasahiro Yamada	help
18292e5d9c85Svenkatesh.pallipadi@intel.com	  Use PAT attributes to setup page level cache control.
1830042b78e4SVenki Pallipadi
18312e5d9c85Svenkatesh.pallipadi@intel.com	  PATs are the modern equivalents of MTRRs and are much more
18322e5d9c85Svenkatesh.pallipadi@intel.com	  flexible than MTRRs.
18332e5d9c85Svenkatesh.pallipadi@intel.com
18342e5d9c85Svenkatesh.pallipadi@intel.com	  Say N here if you see bootup problems (boot crash, boot hang,
1835042b78e4SVenki Pallipadi	  spontaneous reboots) or a non-working video driver.
18362e5d9c85Svenkatesh.pallipadi@intel.com
18372e5d9c85Svenkatesh.pallipadi@intel.com	  If unsure, say Y.
18382e5d9c85Svenkatesh.pallipadi@intel.com
183946cf98cdSVenkatesh Pallipadiconfig ARCH_USES_PG_UNCACHED
184046cf98cdSVenkatesh Pallipadi	def_bool y
184146cf98cdSVenkatesh Pallipadi	depends on X86_PAT
184246cf98cdSVenkatesh Pallipadi
1843628c6246SH. Peter Anvinconfig ARCH_RANDOM
1844628c6246SH. Peter Anvin	def_bool y
1845628c6246SH. Peter Anvin	prompt "x86 architectural random number generator" if EXPERT
1846a7f7f624SMasahiro Yamada	help
1847628c6246SH. Peter Anvin	  Enable the x86 architectural RDRAND instruction
1848628c6246SH. Peter Anvin	  (Intel Bull Mountain technology) to generate random numbers.
1849628c6246SH. Peter Anvin	  If supported, this is a high bandwidth, cryptographically
1850628c6246SH. Peter Anvin	  secure hardware random number generator.
1851628c6246SH. Peter Anvin
185251ae4a2dSH. Peter Anvinconfig X86_SMAP
185351ae4a2dSH. Peter Anvin	def_bool y
185451ae4a2dSH. Peter Anvin	prompt "Supervisor Mode Access Prevention" if EXPERT
1855a7f7f624SMasahiro Yamada	help
185651ae4a2dSH. Peter Anvin	  Supervisor Mode Access Prevention (SMAP) is a security
185751ae4a2dSH. Peter Anvin	  feature in newer Intel processors.  There is a small
185851ae4a2dSH. Peter Anvin	  performance cost if this enabled and turned on; there is
185951ae4a2dSH. Peter Anvin	  also a small increase in the kernel size if this is enabled.
186051ae4a2dSH. Peter Anvin
186151ae4a2dSH. Peter Anvin	  If unsure, say Y.
186251ae4a2dSH. Peter Anvin
1863b971880fSBabu Mogerconfig X86_UMIP
1864796ebc81SRicardo Neri	def_bool y
1865b971880fSBabu Moger	prompt "User Mode Instruction Prevention" if EXPERT
1866a7f7f624SMasahiro Yamada	help
1867b971880fSBabu Moger	  User Mode Instruction Prevention (UMIP) is a security feature in
1868b971880fSBabu Moger	  some x86 processors. If enabled, a general protection fault is
1869b971880fSBabu Moger	  issued if the SGDT, SLDT, SIDT, SMSW or STR instructions are
1870b971880fSBabu Moger	  executed in user mode. These instructions unnecessarily expose
1871b971880fSBabu Moger	  information about the hardware state.
1872796ebc81SRicardo Neri
1873796ebc81SRicardo Neri	  The vast majority of applications do not use these instructions.
1874796ebc81SRicardo Neri	  For the very few that do, software emulation is provided in
1875796ebc81SRicardo Neri	  specific cases in protected and virtual-8086 modes. Emulated
1876796ebc81SRicardo Neri	  results are dummy.
1877aa35f896SRicardo Neri
187835e97790SDave Hansenconfig X86_INTEL_MEMORY_PROTECTION_KEYS
187938f3e775SBabu Moger	prompt "Memory Protection Keys"
188035e97790SDave Hansen	def_bool y
1881284244a9SDave Hansen	# Note: only available in 64-bit mode
188238f3e775SBabu Moger	depends on X86_64 && (CPU_SUP_INTEL || CPU_SUP_AMD)
188352c8e601SIngo Molnar	select ARCH_USES_HIGH_VMA_FLAGS
188452c8e601SIngo Molnar	select ARCH_HAS_PKEYS
1885a7f7f624SMasahiro Yamada	help
1886284244a9SDave Hansen	  Memory Protection Keys provides a mechanism for enforcing
1887284244a9SDave Hansen	  page-based protections, but without requiring modification of the
1888284244a9SDave Hansen	  page tables when an application changes protection domains.
1889284244a9SDave Hansen
18901eecbcdcSMauro Carvalho Chehab	  For details, see Documentation/core-api/protection-keys.rst
1891284244a9SDave Hansen
1892284244a9SDave Hansen	  If unsure, say y.
189335e97790SDave Hansen
1894db616173SMichal Hockochoice
1895db616173SMichal Hocko	prompt "TSX enable mode"
1896db616173SMichal Hocko	depends on CPU_SUP_INTEL
1897db616173SMichal Hocko	default X86_INTEL_TSX_MODE_OFF
1898db616173SMichal Hocko	help
1899db616173SMichal Hocko	  Intel's TSX (Transactional Synchronization Extensions) feature
1900db616173SMichal Hocko	  allows to optimize locking protocols through lock elision which
1901db616173SMichal Hocko	  can lead to a noticeable performance boost.
1902db616173SMichal Hocko
1903db616173SMichal Hocko	  On the other hand it has been shown that TSX can be exploited
1904db616173SMichal Hocko	  to form side channel attacks (e.g. TAA) and chances are there
1905db616173SMichal Hocko	  will be more of those attacks discovered in the future.
1906db616173SMichal Hocko
1907db616173SMichal Hocko	  Therefore TSX is not enabled by default (aka tsx=off). An admin
1908db616173SMichal Hocko	  might override this decision by tsx=on the command line parameter.
1909db616173SMichal Hocko	  Even with TSX enabled, the kernel will attempt to enable the best
1910db616173SMichal Hocko	  possible TAA mitigation setting depending on the microcode available
1911db616173SMichal Hocko	  for the particular machine.
1912db616173SMichal Hocko
1913db616173SMichal Hocko	  This option allows to set the default tsx mode between tsx=on, =off
1914db616173SMichal Hocko	  and =auto. See Documentation/admin-guide/kernel-parameters.txt for more
1915db616173SMichal Hocko	  details.
1916db616173SMichal Hocko
1917db616173SMichal Hocko	  Say off if not sure, auto if TSX is in use but it should be used on safe
1918db616173SMichal Hocko	  platforms or on if TSX is in use and the security aspect of tsx is not
1919db616173SMichal Hocko	  relevant.
1920db616173SMichal Hocko
1921db616173SMichal Hockoconfig X86_INTEL_TSX_MODE_OFF
1922db616173SMichal Hocko	bool "off"
1923db616173SMichal Hocko	help
1924db616173SMichal Hocko	  TSX is disabled if possible - equals to tsx=off command line parameter.
1925db616173SMichal Hocko
1926db616173SMichal Hockoconfig X86_INTEL_TSX_MODE_ON
1927db616173SMichal Hocko	bool "on"
1928db616173SMichal Hocko	help
1929db616173SMichal Hocko	  TSX is always enabled on TSX capable HW - equals the tsx=on command
1930db616173SMichal Hocko	  line parameter.
1931db616173SMichal Hocko
1932db616173SMichal Hockoconfig X86_INTEL_TSX_MODE_AUTO
1933db616173SMichal Hocko	bool "auto"
1934db616173SMichal Hocko	help
1935db616173SMichal Hocko	  TSX is enabled on TSX capable HW that is believed to be safe against
1936db616173SMichal Hocko	  side channel attacks- equals the tsx=auto command line parameter.
1937db616173SMichal Hockoendchoice
1938db616173SMichal Hocko
1939e7e05452SSean Christophersonconfig X86_SGX
1940e7e05452SSean Christopherson	bool "Software Guard eXtensions (SGX)"
1941e7e05452SSean Christopherson	depends on X86_64 && CPU_SUP_INTEL
1942e7e05452SSean Christopherson	depends on CRYPTO=y
1943e7e05452SSean Christopherson	depends on CRYPTO_SHA256=y
1944e7e05452SSean Christopherson	select SRCU
1945e7e05452SSean Christopherson	select MMU_NOTIFIER
1946e7e05452SSean Christopherson	help
1947e7e05452SSean Christopherson	  Intel(R) Software Guard eXtensions (SGX) is a set of CPU instructions
1948e7e05452SSean Christopherson	  that can be used by applications to set aside private regions of code
1949e7e05452SSean Christopherson	  and data, referred to as enclaves. An enclave's private memory can
1950e7e05452SSean Christopherson	  only be accessed by code running within the enclave. Accesses from
1951e7e05452SSean Christopherson	  outside the enclave, including other enclaves, are disallowed by
1952e7e05452SSean Christopherson	  hardware.
1953e7e05452SSean Christopherson
1954e7e05452SSean Christopherson	  If unsure, say N.
1955e7e05452SSean Christopherson
1956506f1d07SSam Ravnborgconfig EFI
19579ba16087SJan Beulich	bool "EFI runtime service support"
19585b83683fSHuang, Ying	depends on ACPI
1959f6ce5002SSergey Vlasov	select UCS2_STRING
1960022ee6c5SArd Biesheuvel	select EFI_RUNTIME_WRAPPERS
1961a7f7f624SMasahiro Yamada	help
19628b2cb7a8SHuang, Ying	  This enables the kernel to use EFI runtime services that are
1963506f1d07SSam Ravnborg	  available (such as the EFI variable services).
1964506f1d07SSam Ravnborg
19658b2cb7a8SHuang, Ying	  This option is only useful on systems that have EFI firmware.
19668b2cb7a8SHuang, Ying	  In addition, you should use the latest ELILO loader available
19678b2cb7a8SHuang, Ying	  at <http://elilo.sourceforge.net> in order to take advantage
19688b2cb7a8SHuang, Ying	  of EFI runtime services. However, even with this option, the
19698b2cb7a8SHuang, Ying	  resultant kernel should continue to boot on existing non-EFI
19708b2cb7a8SHuang, Ying	  platforms.
1971506f1d07SSam Ravnborg
1972291f3632SMatt Flemingconfig EFI_STUB
1973291f3632SMatt Fleming	bool "EFI stub support"
1974b16d8c23SMatt Fleming	depends on EFI && !X86_USE_3DNOW
19758f24f8c2SArd Biesheuvel	depends on $(cc-option,-mabi=ms) || X86_32
19767b2a583aSMatt Fleming	select RELOCATABLE
1977a7f7f624SMasahiro Yamada	help
1978291f3632SMatt Fleming	  This kernel feature allows a bzImage to be loaded directly
1979291f3632SMatt Fleming	  by EFI firmware without the use of a bootloader.
1980291f3632SMatt Fleming
19814f4cfa6cSMauro Carvalho Chehab	  See Documentation/admin-guide/efi-stub.rst for more information.
19820c759662SMatt Fleming
19837d453eeeSMatt Flemingconfig EFI_MIXED
19847d453eeeSMatt Fleming	bool "EFI mixed-mode support"
19857d453eeeSMatt Fleming	depends on EFI_STUB && X86_64
1986a7f7f624SMasahiro Yamada	help
19877d453eeeSMatt Fleming	   Enabling this feature allows a 64-bit kernel to be booted
19887d453eeeSMatt Fleming	   on a 32-bit firmware, provided that your CPU supports 64-bit
19897d453eeeSMatt Fleming	   mode.
19907d453eeeSMatt Fleming
19917d453eeeSMatt Fleming	   Note that it is not possible to boot a mixed-mode enabled
19927d453eeeSMatt Fleming	   kernel via the EFI boot stub - a bootloader that supports
19937d453eeeSMatt Fleming	   the EFI handover protocol must be used.
19947d453eeeSMatt Fleming
19957d453eeeSMatt Fleming	   If unsure, say N.
19967d453eeeSMatt Fleming
19978636a1f9SMasahiro Yamadasource "kernel/Kconfig.hz"
1998506f1d07SSam Ravnborg
1999506f1d07SSam Ravnborgconfig KEXEC
2000506f1d07SSam Ravnborg	bool "kexec system call"
20012965faa5SDave Young	select KEXEC_CORE
2002a7f7f624SMasahiro Yamada	help
2003506f1d07SSam Ravnborg	  kexec is a system call that implements the ability to shutdown your
2004506f1d07SSam Ravnborg	  current kernel, and to start another kernel.  It is like a reboot
2005506f1d07SSam Ravnborg	  but it is independent of the system firmware.   And like a reboot
2006506f1d07SSam Ravnborg	  you can start any kernel with it, not just Linux.
2007506f1d07SSam Ravnborg
2008506f1d07SSam Ravnborg	  The name comes from the similarity to the exec system call.
2009506f1d07SSam Ravnborg
2010506f1d07SSam Ravnborg	  It is an ongoing process to be certain the hardware in a machine
2011506f1d07SSam Ravnborg	  is properly shutdown, so do not be surprised if this code does not
2012bf220695SGeert Uytterhoeven	  initially work for you.  As of this writing the exact hardware
2013bf220695SGeert Uytterhoeven	  interface is strongly in flux, so no good recommendation can be
2014bf220695SGeert Uytterhoeven	  made.
2015506f1d07SSam Ravnborg
201674ca317cSVivek Goyalconfig KEXEC_FILE
201774ca317cSVivek Goyal	bool "kexec file based system call"
20182965faa5SDave Young	select KEXEC_CORE
201974ca317cSVivek Goyal	select BUILD_BIN2C
202074ca317cSVivek Goyal	depends on X86_64
202174ca317cSVivek Goyal	depends on CRYPTO=y
202274ca317cSVivek Goyal	depends on CRYPTO_SHA256=y
2023a7f7f624SMasahiro Yamada	help
202474ca317cSVivek Goyal	  This is new version of kexec system call. This system call is
202574ca317cSVivek Goyal	  file based and takes file descriptors as system call argument
202674ca317cSVivek Goyal	  for kernel and initramfs as opposed to list of segments as
202774ca317cSVivek Goyal	  accepted by previous system call.
202874ca317cSVivek Goyal
2029b799a09fSAKASHI Takahiroconfig ARCH_HAS_KEXEC_PURGATORY
2030b799a09fSAKASHI Takahiro	def_bool KEXEC_FILE
2031b799a09fSAKASHI Takahiro
203299d5cadfSJiri Bohacconfig KEXEC_SIG
20338e7d8381SVivek Goyal	bool "Verify kernel signature during kexec_file_load() syscall"
203474ca317cSVivek Goyal	depends on KEXEC_FILE
2035a7f7f624SMasahiro Yamada	help
203699d5cadfSJiri Bohac
203799d5cadfSJiri Bohac	  This option makes the kexec_file_load() syscall check for a valid
203899d5cadfSJiri Bohac	  signature of the kernel image.  The image can still be loaded without
203999d5cadfSJiri Bohac	  a valid signature unless you also enable KEXEC_SIG_FORCE, though if
204099d5cadfSJiri Bohac	  there's a signature that we can check, then it must be valid.
204199d5cadfSJiri Bohac
204299d5cadfSJiri Bohac	  In addition to this option, you need to enable signature
204399d5cadfSJiri Bohac	  verification for the corresponding kernel image type being
204499d5cadfSJiri Bohac	  loaded in order for this to work.
204599d5cadfSJiri Bohac
204699d5cadfSJiri Bohacconfig KEXEC_SIG_FORCE
204799d5cadfSJiri Bohac	bool "Require a valid signature in kexec_file_load() syscall"
204899d5cadfSJiri Bohac	depends on KEXEC_SIG
2049a7f7f624SMasahiro Yamada	help
20508e7d8381SVivek Goyal	  This option makes kernel signature verification mandatory for
2051d8eb8940SBorislav Petkov	  the kexec_file_load() syscall.
20528e7d8381SVivek Goyal
20538e7d8381SVivek Goyalconfig KEXEC_BZIMAGE_VERIFY_SIG
20548e7d8381SVivek Goyal	bool "Enable bzImage signature verification support"
205599d5cadfSJiri Bohac	depends on KEXEC_SIG
20568e7d8381SVivek Goyal	depends on SIGNED_PE_FILE_VERIFICATION
20578e7d8381SVivek Goyal	select SYSTEM_TRUSTED_KEYRING
2058a7f7f624SMasahiro Yamada	help
20598e7d8381SVivek Goyal	  Enable bzImage signature verification support.
20608e7d8381SVivek Goyal
2061506f1d07SSam Ravnborgconfig CRASH_DUMP
206204b69447SPavel Machek	bool "kernel crash dumps"
2063506f1d07SSam Ravnborg	depends on X86_64 || (X86_32 && HIGHMEM)
2064a7f7f624SMasahiro Yamada	help
2065506f1d07SSam Ravnborg	  Generate crash dump after being started by kexec.
2066506f1d07SSam Ravnborg	  This should be normally only set in special crash dump kernels
2067506f1d07SSam Ravnborg	  which are loaded in the main kernel with kexec-tools into
2068506f1d07SSam Ravnborg	  a specially reserved region and then later executed after
2069506f1d07SSam Ravnborg	  a crash by kdump/kexec. The crash dump kernel must be compiled
2070506f1d07SSam Ravnborg	  to a memory address not used by the main kernel or BIOS using
2071506f1d07SSam Ravnborg	  PHYSICAL_START, or it must be built as a relocatable image
2072506f1d07SSam Ravnborg	  (CONFIG_RELOCATABLE=y).
2073330d4810SMauro Carvalho Chehab	  For more details see Documentation/admin-guide/kdump/kdump.rst
2074506f1d07SSam Ravnborg
20753ab83521SHuang Yingconfig KEXEC_JUMP
20766ea30386SKees Cook	bool "kexec jump"
2077fee7b0d8SHuang Ying	depends on KEXEC && HIBERNATION
2078a7f7f624SMasahiro Yamada	help
207989081d17SHuang Ying	  Jump between original kernel and kexeced kernel and invoke
208089081d17SHuang Ying	  code in physical address mode via KEXEC
20813ab83521SHuang Ying
2082506f1d07SSam Ravnborgconfig PHYSICAL_START
20836a108a14SDavid Rientjes	hex "Physical address where the kernel is loaded" if (EXPERT || CRASH_DUMP)
2084ceefccc9SH. Peter Anvin	default "0x1000000"
2085a7f7f624SMasahiro Yamada	help
2086506f1d07SSam Ravnborg	  This gives the physical address where the kernel is loaded.
2087506f1d07SSam Ravnborg
2088506f1d07SSam Ravnborg	  If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then
2089506f1d07SSam Ravnborg	  bzImage will decompress itself to above physical address and
2090506f1d07SSam Ravnborg	  run from there. Otherwise, bzImage will run from the address where
2091506f1d07SSam Ravnborg	  it has been loaded by the boot loader and will ignore above physical
2092506f1d07SSam Ravnborg	  address.
2093506f1d07SSam Ravnborg
2094506f1d07SSam Ravnborg	  In normal kdump cases one does not have to set/change this option
2095506f1d07SSam Ravnborg	  as now bzImage can be compiled as a completely relocatable image
2096506f1d07SSam Ravnborg	  (CONFIG_RELOCATABLE=y) and be used to load and run from a different
2097506f1d07SSam Ravnborg	  address. This option is mainly useful for the folks who don't want
2098506f1d07SSam Ravnborg	  to use a bzImage for capturing the crash dump and want to use a
2099506f1d07SSam Ravnborg	  vmlinux instead. vmlinux is not relocatable hence a kernel needs
2100506f1d07SSam Ravnborg	  to be specifically compiled to run from a specific memory area
2101506f1d07SSam Ravnborg	  (normally a reserved region) and this option comes handy.
2102506f1d07SSam Ravnborg
2103ceefccc9SH. Peter Anvin	  So if you are using bzImage for capturing the crash dump,
2104ceefccc9SH. Peter Anvin	  leave the value here unchanged to 0x1000000 and set
2105ceefccc9SH. Peter Anvin	  CONFIG_RELOCATABLE=y.  Otherwise if you plan to use vmlinux
2106ceefccc9SH. Peter Anvin	  for capturing the crash dump change this value to start of
2107ceefccc9SH. Peter Anvin	  the reserved region.  In other words, it can be set based on
2108ceefccc9SH. Peter Anvin	  the "X" value as specified in the "crashkernel=YM@XM"
2109ceefccc9SH. Peter Anvin	  command line boot parameter passed to the panic-ed
2110330d4810SMauro Carvalho Chehab	  kernel. Please take a look at Documentation/admin-guide/kdump/kdump.rst
2111ceefccc9SH. Peter Anvin	  for more details about crash dumps.
2112506f1d07SSam Ravnborg
2113506f1d07SSam Ravnborg	  Usage of bzImage for capturing the crash dump is recommended as
2114506f1d07SSam Ravnborg	  one does not have to build two kernels. Same kernel can be used
2115506f1d07SSam Ravnborg	  as production kernel and capture kernel. Above option should have
2116506f1d07SSam Ravnborg	  gone away after relocatable bzImage support is introduced. But it
2117506f1d07SSam Ravnborg	  is present because there are users out there who continue to use
2118506f1d07SSam Ravnborg	  vmlinux for dump capture. This option should go away down the
2119506f1d07SSam Ravnborg	  line.
2120506f1d07SSam Ravnborg
2121506f1d07SSam Ravnborg	  Don't change this unless you know what you are doing.
2122506f1d07SSam Ravnborg
2123506f1d07SSam Ravnborgconfig RELOCATABLE
212426717808SH. Peter Anvin	bool "Build a relocatable kernel"
212526717808SH. Peter Anvin	default y
2126a7f7f624SMasahiro Yamada	help
2127506f1d07SSam Ravnborg	  This builds a kernel image that retains relocation information
2128506f1d07SSam Ravnborg	  so it can be loaded someplace besides the default 1MB.
2129506f1d07SSam Ravnborg	  The relocations tend to make the kernel binary about 10% larger,
2130506f1d07SSam Ravnborg	  but are discarded at runtime.
2131506f1d07SSam Ravnborg
2132506f1d07SSam Ravnborg	  One use is for the kexec on panic case where the recovery kernel
2133506f1d07SSam Ravnborg	  must live at a different physical address than the primary
2134506f1d07SSam Ravnborg	  kernel.
2135506f1d07SSam Ravnborg
2136506f1d07SSam Ravnborg	  Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address
2137506f1d07SSam Ravnborg	  it has been loaded at and the compile time physical address
21388ab3820fSKees Cook	  (CONFIG_PHYSICAL_START) is used as the minimum location.
2139506f1d07SSam Ravnborg
21408ab3820fSKees Cookconfig RANDOMIZE_BASE
2141e8581e3dSBaoquan He	bool "Randomize the address of the kernel image (KASLR)"
21428ab3820fSKees Cook	depends on RELOCATABLE
21436807c846SIngo Molnar	default y
2144a7f7f624SMasahiro Yamada	help
2145e8581e3dSBaoquan He	  In support of Kernel Address Space Layout Randomization (KASLR),
2146e8581e3dSBaoquan He	  this randomizes the physical address at which the kernel image
2147e8581e3dSBaoquan He	  is decompressed and the virtual address where the kernel
2148e8581e3dSBaoquan He	  image is mapped, as a security feature that deters exploit
2149e8581e3dSBaoquan He	  attempts relying on knowledge of the location of kernel
2150e8581e3dSBaoquan He	  code internals.
2151e8581e3dSBaoquan He
2152ed9f007eSKees Cook	  On 64-bit, the kernel physical and virtual addresses are
2153ed9f007eSKees Cook	  randomized separately. The physical address will be anywhere
2154ed9f007eSKees Cook	  between 16MB and the top of physical memory (up to 64TB). The
2155ed9f007eSKees Cook	  virtual address will be randomized from 16MB up to 1GB (9 bits
2156ed9f007eSKees Cook	  of entropy). Note that this also reduces the memory space
2157ed9f007eSKees Cook	  available to kernel modules from 1.5GB to 1GB.
2158ed9f007eSKees Cook
2159ed9f007eSKees Cook	  On 32-bit, the kernel physical and virtual addresses are
2160ed9f007eSKees Cook	  randomized together. They will be randomized from 16MB up to
2161ed9f007eSKees Cook	  512MB (8 bits of entropy).
21628ab3820fSKees Cook
2163a653f356SKees Cook	  Entropy is generated using the RDRAND instruction if it is
2164e8581e3dSBaoquan He	  supported. If RDTSC is supported, its value is mixed into
2165e8581e3dSBaoquan He	  the entropy pool as well. If neither RDRAND nor RDTSC are
2166ed9f007eSKees Cook	  supported, then entropy is read from the i8254 timer. The
2167ed9f007eSKees Cook	  usable entropy is limited by the kernel being built using
2168ed9f007eSKees Cook	  2GB addressing, and that PHYSICAL_ALIGN must be at a
2169ed9f007eSKees Cook	  minimum of 2MB. As a result, only 10 bits of entropy are
2170ed9f007eSKees Cook	  theoretically possible, but the implementations are further
2171ed9f007eSKees Cook	  limited due to memory layouts.
2172e8581e3dSBaoquan He
21736807c846SIngo Molnar	  If unsure, say Y.
2174da2b6fb9SKees Cook
21758ab3820fSKees Cook# Relocation on x86 needs some additional build support
2176845adf72SH. Peter Anvinconfig X86_NEED_RELOCS
2177845adf72SH. Peter Anvin	def_bool y
21788ab3820fSKees Cook	depends on RANDOMIZE_BASE || (X86_32 && RELOCATABLE)
2179845adf72SH. Peter Anvin
2180506f1d07SSam Ravnborgconfig PHYSICAL_ALIGN
2181a0215061SKees Cook	hex "Alignment value to which kernel should be aligned"
21828ab3820fSKees Cook	default "0x200000"
2183a0215061SKees Cook	range 0x2000 0x1000000 if X86_32
2184a0215061SKees Cook	range 0x200000 0x1000000 if X86_64
2185a7f7f624SMasahiro Yamada	help
2186506f1d07SSam Ravnborg	  This value puts the alignment restrictions on physical address
2187506f1d07SSam Ravnborg	  where kernel is loaded and run from. Kernel is compiled for an
2188506f1d07SSam Ravnborg	  address which meets above alignment restriction.
2189506f1d07SSam Ravnborg
2190506f1d07SSam Ravnborg	  If bootloader loads the kernel at a non-aligned address and
2191506f1d07SSam Ravnborg	  CONFIG_RELOCATABLE is set, kernel will move itself to nearest
2192506f1d07SSam Ravnborg	  address aligned to above value and run from there.
2193506f1d07SSam Ravnborg
2194506f1d07SSam Ravnborg	  If bootloader loads the kernel at a non-aligned address and
2195506f1d07SSam Ravnborg	  CONFIG_RELOCATABLE is not set, kernel will ignore the run time
2196506f1d07SSam Ravnborg	  load address and decompress itself to the address it has been
2197506f1d07SSam Ravnborg	  compiled for and run from there. The address for which kernel is
2198506f1d07SSam Ravnborg	  compiled already meets above alignment restrictions. Hence the
2199506f1d07SSam Ravnborg	  end result is that kernel runs from a physical address meeting
2200506f1d07SSam Ravnborg	  above alignment restrictions.
2201506f1d07SSam Ravnborg
2202a0215061SKees Cook	  On 32-bit this value must be a multiple of 0x2000. On 64-bit
2203a0215061SKees Cook	  this value must be a multiple of 0x200000.
2204a0215061SKees Cook
2205506f1d07SSam Ravnborg	  Don't change this unless you know what you are doing.
2206506f1d07SSam Ravnborg
2207eedb92abSKirill A. Shutemovconfig DYNAMIC_MEMORY_LAYOUT
2208eedb92abSKirill A. Shutemov	bool
2209a7f7f624SMasahiro Yamada	help
2210eedb92abSKirill A. Shutemov	  This option makes base addresses of vmalloc and vmemmap as well as
2211eedb92abSKirill A. Shutemov	  __PAGE_OFFSET movable during boot.
2212eedb92abSKirill A. Shutemov
22130483e1faSThomas Garnierconfig RANDOMIZE_MEMORY
22140483e1faSThomas Garnier	bool "Randomize the kernel memory sections"
22150483e1faSThomas Garnier	depends on X86_64
22160483e1faSThomas Garnier	depends on RANDOMIZE_BASE
2217eedb92abSKirill A. Shutemov	select DYNAMIC_MEMORY_LAYOUT
22180483e1faSThomas Garnier	default RANDOMIZE_BASE
2219a7f7f624SMasahiro Yamada	help
22200483e1faSThomas Garnier	   Randomizes the base virtual address of kernel memory sections
22210483e1faSThomas Garnier	   (physical memory mapping, vmalloc & vmemmap). This security feature
22220483e1faSThomas Garnier	   makes exploits relying on predictable memory locations less reliable.
22230483e1faSThomas Garnier
22240483e1faSThomas Garnier	   The order of allocations remains unchanged. Entropy is generated in
22250483e1faSThomas Garnier	   the same way as RANDOMIZE_BASE. Current implementation in the optimal
22260483e1faSThomas Garnier	   configuration have in average 30,000 different possible virtual
22270483e1faSThomas Garnier	   addresses for each memory section.
22280483e1faSThomas Garnier
22296807c846SIngo Molnar	   If unsure, say Y.
22300483e1faSThomas Garnier
223190397a41SThomas Garnierconfig RANDOMIZE_MEMORY_PHYSICAL_PADDING
223290397a41SThomas Garnier	hex "Physical memory mapping padding" if EXPERT
223390397a41SThomas Garnier	depends on RANDOMIZE_MEMORY
223490397a41SThomas Garnier	default "0xa" if MEMORY_HOTPLUG
223590397a41SThomas Garnier	default "0x0"
223690397a41SThomas Garnier	range 0x1 0x40 if MEMORY_HOTPLUG
223790397a41SThomas Garnier	range 0x0 0x40
2238a7f7f624SMasahiro Yamada	help
223990397a41SThomas Garnier	   Define the padding in terabytes added to the existing physical
224090397a41SThomas Garnier	   memory size during kernel memory randomization. It is useful
224190397a41SThomas Garnier	   for memory hotplug support but reduces the entropy available for
224290397a41SThomas Garnier	   address randomization.
224390397a41SThomas Garnier
224490397a41SThomas Garnier	   If unsure, leave at the default value.
224590397a41SThomas Garnier
2246506f1d07SSam Ravnborgconfig HOTPLUG_CPU
2247bebd024eSThomas Gleixner	def_bool y
224840b31360SStephen Rothwell	depends on SMP
2249506f1d07SSam Ravnborg
225080aa1dffSFenghua Yuconfig BOOTPARAM_HOTPLUG_CPU0
225180aa1dffSFenghua Yu	bool "Set default setting of cpu0_hotpluggable"
22522c922cd0SKees Cook	depends on HOTPLUG_CPU
2253a7f7f624SMasahiro Yamada	help
225480aa1dffSFenghua Yu	  Set whether default state of cpu0_hotpluggable is on or off.
225580aa1dffSFenghua Yu
225680aa1dffSFenghua Yu	  Say Y here to enable CPU0 hotplug by default. If this switch
225780aa1dffSFenghua Yu	  is turned on, there is no need to give cpu0_hotplug kernel
225880aa1dffSFenghua Yu	  parameter and the CPU0 hotplug feature is enabled by default.
225980aa1dffSFenghua Yu
226080aa1dffSFenghua Yu	  Please note: there are two known CPU0 dependencies if you want
226180aa1dffSFenghua Yu	  to enable the CPU0 hotplug feature either by this switch or by
226280aa1dffSFenghua Yu	  cpu0_hotplug kernel parameter.
226380aa1dffSFenghua Yu
226480aa1dffSFenghua Yu	  First, resume from hibernate or suspend always starts from CPU0.
226580aa1dffSFenghua Yu	  So hibernate and suspend are prevented if CPU0 is offline.
226680aa1dffSFenghua Yu
226780aa1dffSFenghua Yu	  Second dependency is PIC interrupts always go to CPU0. CPU0 can not
226880aa1dffSFenghua Yu	  offline if any interrupt can not migrate out of CPU0. There may
226980aa1dffSFenghua Yu	  be other CPU0 dependencies.
227080aa1dffSFenghua Yu
227180aa1dffSFenghua Yu	  Please make sure the dependencies are under your control before
227280aa1dffSFenghua Yu	  you enable this feature.
227380aa1dffSFenghua Yu
227480aa1dffSFenghua Yu	  Say N if you don't want to enable CPU0 hotplug feature by default.
227580aa1dffSFenghua Yu	  You still can enable the CPU0 hotplug feature at boot by kernel
227680aa1dffSFenghua Yu	  parameter cpu0_hotplug.
227780aa1dffSFenghua Yu
2278a71c8bc5SFenghua Yuconfig DEBUG_HOTPLUG_CPU0
2279a71c8bc5SFenghua Yu	def_bool n
2280a71c8bc5SFenghua Yu	prompt "Debug CPU0 hotplug"
22812c922cd0SKees Cook	depends on HOTPLUG_CPU
2282a7f7f624SMasahiro Yamada	help
2283a71c8bc5SFenghua Yu	  Enabling this option offlines CPU0 (if CPU0 can be offlined) as
2284a71c8bc5SFenghua Yu	  soon as possible and boots up userspace with CPU0 offlined. User
2285a71c8bc5SFenghua Yu	  can online CPU0 back after boot time.
2286a71c8bc5SFenghua Yu
2287a71c8bc5SFenghua Yu	  To debug CPU0 hotplug, you need to enable CPU0 offline/online
2288a71c8bc5SFenghua Yu	  feature by either turning on CONFIG_BOOTPARAM_HOTPLUG_CPU0 during
2289a71c8bc5SFenghua Yu	  compilation or giving cpu0_hotplug kernel parameter at boot.
2290a71c8bc5SFenghua Yu
2291a71c8bc5SFenghua Yu	  If unsure, say N.
2292a71c8bc5SFenghua Yu
2293506f1d07SSam Ravnborgconfig COMPAT_VDSO
2294b0b49f26SAndy Lutomirski	def_bool n
2295b0b49f26SAndy Lutomirski	prompt "Disable the 32-bit vDSO (needed for glibc 2.3.3)"
2296953fee1dSIngo Molnar	depends on COMPAT_32
2297a7f7f624SMasahiro Yamada	help
2298b0b49f26SAndy Lutomirski	  Certain buggy versions of glibc will crash if they are
2299b0b49f26SAndy Lutomirski	  presented with a 32-bit vDSO that is not mapped at the address
2300b0b49f26SAndy Lutomirski	  indicated in its segment table.
2301e84446deSRandy Dunlap
2302b0b49f26SAndy Lutomirski	  The bug was introduced by f866314b89d56845f55e6f365e18b31ec978ec3a
2303b0b49f26SAndy Lutomirski	  and fixed by 3b3ddb4f7db98ec9e912ccdf54d35df4aa30e04a and
2304b0b49f26SAndy Lutomirski	  49ad572a70b8aeb91e57483a11dd1b77e31c4468.  Glibc 2.3.3 is
2305b0b49f26SAndy Lutomirski	  the only released version with the bug, but OpenSUSE 9
2306b0b49f26SAndy Lutomirski	  contains a buggy "glibc 2.3.2".
2307506f1d07SSam Ravnborg
2308b0b49f26SAndy Lutomirski	  The symptom of the bug is that everything crashes on startup, saying:
2309b0b49f26SAndy Lutomirski	  dl_main: Assertion `(void *) ph->p_vaddr == _rtld_local._dl_sysinfo_dso' failed!
2310b0b49f26SAndy Lutomirski
2311b0b49f26SAndy Lutomirski	  Saying Y here changes the default value of the vdso32 boot
2312b0b49f26SAndy Lutomirski	  option from 1 to 0, which turns off the 32-bit vDSO entirely.
2313b0b49f26SAndy Lutomirski	  This works around the glibc bug but hurts performance.
2314b0b49f26SAndy Lutomirski
2315b0b49f26SAndy Lutomirski	  If unsure, say N: if you are compiling your own kernel, you
2316b0b49f26SAndy Lutomirski	  are unlikely to be using a buggy version of glibc.
2317506f1d07SSam Ravnborg
23183dc33bd3SKees Cookchoice
23193dc33bd3SKees Cook	prompt "vsyscall table for legacy applications"
23203dc33bd3SKees Cook	depends on X86_64
2321625b7b7fSAndy Lutomirski	default LEGACY_VSYSCALL_XONLY
23223dc33bd3SKees Cook	help
23233dc33bd3SKees Cook	  Legacy user code that does not know how to find the vDSO expects
23243dc33bd3SKees Cook	  to be able to issue three syscalls by calling fixed addresses in
23253dc33bd3SKees Cook	  kernel space. Since this location is not randomized with ASLR,
23263dc33bd3SKees Cook	  it can be used to assist security vulnerability exploitation.
23273dc33bd3SKees Cook
23283dc33bd3SKees Cook	  This setting can be changed at boot time via the kernel command
2329bd49e16eSAndy Lutomirski	  line parameter vsyscall=[emulate|xonly|none].
23303dc33bd3SKees Cook
23313dc33bd3SKees Cook	  On a system with recent enough glibc (2.14 or newer) and no
23323dc33bd3SKees Cook	  static binaries, you can say None without a performance penalty
23333dc33bd3SKees Cook	  to improve security.
23343dc33bd3SKees Cook
2335bd49e16eSAndy Lutomirski	  If unsure, select "Emulate execution only".
23363dc33bd3SKees Cook
23373dc33bd3SKees Cook	config LEGACY_VSYSCALL_EMULATE
2338bd49e16eSAndy Lutomirski		bool "Full emulation"
23393dc33bd3SKees Cook		help
2340bd49e16eSAndy Lutomirski		  The kernel traps and emulates calls into the fixed vsyscall
2341bd49e16eSAndy Lutomirski		  address mapping. This makes the mapping non-executable, but
2342bd49e16eSAndy Lutomirski		  it still contains readable known contents, which could be
2343bd49e16eSAndy Lutomirski		  used in certain rare security vulnerability exploits. This
2344bd49e16eSAndy Lutomirski		  configuration is recommended when using legacy userspace
2345bd49e16eSAndy Lutomirski		  that still uses vsyscalls along with legacy binary
2346bd49e16eSAndy Lutomirski		  instrumentation tools that require code to be readable.
2347bd49e16eSAndy Lutomirski
2348bd49e16eSAndy Lutomirski		  An example of this type of legacy userspace is running
2349bd49e16eSAndy Lutomirski		  Pin on an old binary that still uses vsyscalls.
2350bd49e16eSAndy Lutomirski
2351bd49e16eSAndy Lutomirski	config LEGACY_VSYSCALL_XONLY
2352bd49e16eSAndy Lutomirski		bool "Emulate execution only"
2353bd49e16eSAndy Lutomirski		help
2354bd49e16eSAndy Lutomirski		  The kernel traps and emulates calls into the fixed vsyscall
2355bd49e16eSAndy Lutomirski		  address mapping and does not allow reads.  This
2356bd49e16eSAndy Lutomirski		  configuration is recommended when userspace might use the
2357bd49e16eSAndy Lutomirski		  legacy vsyscall area but support for legacy binary
2358bd49e16eSAndy Lutomirski		  instrumentation of legacy code is not needed.  It mitigates
2359bd49e16eSAndy Lutomirski		  certain uses of the vsyscall area as an ASLR-bypassing
2360bd49e16eSAndy Lutomirski		  buffer.
23613dc33bd3SKees Cook
23623dc33bd3SKees Cook	config LEGACY_VSYSCALL_NONE
23633dc33bd3SKees Cook		bool "None"
23643dc33bd3SKees Cook		help
23653dc33bd3SKees Cook		  There will be no vsyscall mapping at all. This will
23663dc33bd3SKees Cook		  eliminate any risk of ASLR bypass due to the vsyscall
23673dc33bd3SKees Cook		  fixed address mapping. Attempts to use the vsyscalls
23683dc33bd3SKees Cook		  will be reported to dmesg, so that either old or
23693dc33bd3SKees Cook		  malicious userspace programs can be identified.
23703dc33bd3SKees Cook
23713dc33bd3SKees Cookendchoice
23723dc33bd3SKees Cook
2373516cbf37STim Birdconfig CMDLINE_BOOL
2374516cbf37STim Bird	bool "Built-in kernel command line"
2375a7f7f624SMasahiro Yamada	help
2376516cbf37STim Bird	  Allow for specifying boot arguments to the kernel at
2377516cbf37STim Bird	  build time.  On some systems (e.g. embedded ones), it is
2378516cbf37STim Bird	  necessary or convenient to provide some or all of the
2379516cbf37STim Bird	  kernel boot arguments with the kernel itself (that is,
2380516cbf37STim Bird	  to not rely on the boot loader to provide them.)
2381516cbf37STim Bird
2382516cbf37STim Bird	  To compile command line arguments into the kernel,
2383516cbf37STim Bird	  set this option to 'Y', then fill in the
238469711ca1SSébastien Hinderer	  boot arguments in CONFIG_CMDLINE.
2385516cbf37STim Bird
2386516cbf37STim Bird	  Systems with fully functional boot loaders (i.e. non-embedded)
2387516cbf37STim Bird	  should leave this option set to 'N'.
2388516cbf37STim Bird
2389516cbf37STim Birdconfig CMDLINE
2390516cbf37STim Bird	string "Built-in kernel command string"
2391516cbf37STim Bird	depends on CMDLINE_BOOL
2392516cbf37STim Bird	default ""
2393a7f7f624SMasahiro Yamada	help
2394516cbf37STim Bird	  Enter arguments here that should be compiled into the kernel
2395516cbf37STim Bird	  image and used at boot time.  If the boot loader provides a
2396516cbf37STim Bird	  command line at boot time, it is appended to this string to
2397516cbf37STim Bird	  form the full kernel command line, when the system boots.
2398516cbf37STim Bird
2399516cbf37STim Bird	  However, you can use the CONFIG_CMDLINE_OVERRIDE option to
2400516cbf37STim Bird	  change this behavior.
2401516cbf37STim Bird
2402516cbf37STim Bird	  In most cases, the command line (whether built-in or provided
2403516cbf37STim Bird	  by the boot loader) should specify the device for the root
2404516cbf37STim Bird	  file system.
2405516cbf37STim Bird
2406516cbf37STim Birdconfig CMDLINE_OVERRIDE
2407516cbf37STim Bird	bool "Built-in command line overrides boot loader arguments"
2408645e6466SAnders Roxell	depends on CMDLINE_BOOL && CMDLINE != ""
2409a7f7f624SMasahiro Yamada	help
2410516cbf37STim Bird	  Set this option to 'Y' to have the kernel ignore the boot loader
2411516cbf37STim Bird	  command line, and use ONLY the built-in command line.
2412516cbf37STim Bird
2413516cbf37STim Bird	  This is used to work around broken boot loaders.  This should
2414516cbf37STim Bird	  be set to 'N' under normal conditions.
2415516cbf37STim Bird
2416a5b9e5a2SAndy Lutomirskiconfig MODIFY_LDT_SYSCALL
2417a5b9e5a2SAndy Lutomirski	bool "Enable the LDT (local descriptor table)" if EXPERT
2418a5b9e5a2SAndy Lutomirski	default y
2419a7f7f624SMasahiro Yamada	help
2420a5b9e5a2SAndy Lutomirski	  Linux can allow user programs to install a per-process x86
2421a5b9e5a2SAndy Lutomirski	  Local Descriptor Table (LDT) using the modify_ldt(2) system
2422a5b9e5a2SAndy Lutomirski	  call.  This is required to run 16-bit or segmented code such as
2423a5b9e5a2SAndy Lutomirski	  DOSEMU or some Wine programs.  It is also used by some very old
2424a5b9e5a2SAndy Lutomirski	  threading libraries.
2425a5b9e5a2SAndy Lutomirski
2426a5b9e5a2SAndy Lutomirski	  Enabling this feature adds a small amount of overhead to
2427a5b9e5a2SAndy Lutomirski	  context switches and increases the low-level kernel attack
2428a5b9e5a2SAndy Lutomirski	  surface.  Disabling it removes the modify_ldt(2) system call.
2429a5b9e5a2SAndy Lutomirski
2430a5b9e5a2SAndy Lutomirski	  Saying 'N' here may make sense for embedded or server kernels.
2431a5b9e5a2SAndy Lutomirski
2432b700e7f0SSeth Jenningssource "kernel/livepatch/Kconfig"
2433b700e7f0SSeth Jennings
2434506f1d07SSam Ravnborgendmenu
2435506f1d07SSam Ravnborg
24363072e413SMichal Hockoconfig ARCH_HAS_ADD_PAGES
24373072e413SMichal Hocko	def_bool y
24383072e413SMichal Hocko	depends on X86_64 && ARCH_ENABLE_MEMORY_HOTPLUG
24393072e413SMichal Hocko
2440506f1d07SSam Ravnborgconfig ARCH_ENABLE_MEMORY_HOTPLUG
2441506f1d07SSam Ravnborg	def_bool y
2442506f1d07SSam Ravnborg	depends on X86_64 || (X86_32 && HIGHMEM)
2443506f1d07SSam Ravnborg
244435551053SGary Hadeconfig ARCH_ENABLE_MEMORY_HOTREMOVE
244535551053SGary Hade	def_bool y
244635551053SGary Hade	depends on MEMORY_HOTPLUG
244735551053SGary Hade
2448e534c7c5SLee Schermerhornconfig USE_PERCPU_NUMA_NODE_ID
2449645a7919STejun Heo	def_bool y
2450e534c7c5SLee Schermerhorn	depends on NUMA
2451e534c7c5SLee Schermerhorn
24529491846fSKirill A. Shutemovconfig ARCH_ENABLE_SPLIT_PMD_PTLOCK
24539491846fSKirill A. Shutemov	def_bool y
24549491846fSKirill A. Shutemov	depends on X86_64 || X86_PAE
24559491846fSKirill A. Shutemov
2456c177c81eSNaoya Horiguchiconfig ARCH_ENABLE_HUGEPAGE_MIGRATION
2457c177c81eSNaoya Horiguchi	def_bool y
2458c177c81eSNaoya Horiguchi	depends on X86_64 && HUGETLB_PAGE && MIGRATION
2459c177c81eSNaoya Horiguchi
24609c670ea3SNaoya Horiguchiconfig ARCH_ENABLE_THP_MIGRATION
24619c670ea3SNaoya Horiguchi	def_bool y
24629c670ea3SNaoya Horiguchi	depends on X86_64 && TRANSPARENT_HUGEPAGE
24639c670ea3SNaoya Horiguchi
2464da85f865SBjorn Helgaasmenu "Power management and ACPI options"
2465e279b6c1SSam Ravnborg
2466e279b6c1SSam Ravnborgconfig ARCH_HIBERNATION_HEADER
24673c2362e6SHarvey Harrison	def_bool y
246844556530SZhimin Gu	depends on HIBERNATION
2469e279b6c1SSam Ravnborg
2470e279b6c1SSam Ravnborgsource "kernel/power/Kconfig"
2471e279b6c1SSam Ravnborg
2472e279b6c1SSam Ravnborgsource "drivers/acpi/Kconfig"
2473e279b6c1SSam Ravnborg
2474efafc8b2SFeng Tangsource "drivers/sfi/Kconfig"
2475efafc8b2SFeng Tang
2476a6b68076SAndi Kleenconfig X86_APM_BOOT
24776fc108a0SJan Beulich	def_bool y
2478282e5aabSPaul Bolle	depends on APM
2479a6b68076SAndi Kleen
2480e279b6c1SSam Ravnborgmenuconfig APM
2481e279b6c1SSam Ravnborg	tristate "APM (Advanced Power Management) BIOS support"
2482efefa6f6SIngo Molnar	depends on X86_32 && PM_SLEEP
2483a7f7f624SMasahiro Yamada	help
2484e279b6c1SSam Ravnborg	  APM is a BIOS specification for saving power using several different
2485e279b6c1SSam Ravnborg	  techniques. This is mostly useful for battery powered laptops with
2486e279b6c1SSam Ravnborg	  APM compliant BIOSes. If you say Y here, the system time will be
2487e279b6c1SSam Ravnborg	  reset after a RESUME operation, the /proc/apm device will provide
2488e279b6c1SSam Ravnborg	  battery status information, and user-space programs will receive
2489e279b6c1SSam Ravnborg	  notification of APM "events" (e.g. battery status change).
2490e279b6c1SSam Ravnborg
2491e279b6c1SSam Ravnborg	  If you select "Y" here, you can disable actual use of the APM
2492e279b6c1SSam Ravnborg	  BIOS by passing the "apm=off" option to the kernel at boot time.
2493e279b6c1SSam Ravnborg
2494e279b6c1SSam Ravnborg	  Note that the APM support is almost completely disabled for
2495e279b6c1SSam Ravnborg	  machines with more than one CPU.
2496e279b6c1SSam Ravnborg
2497e279b6c1SSam Ravnborg	  In order to use APM, you will need supporting software. For location
2498151f4e2bSMauro Carvalho Chehab	  and more information, read <file:Documentation/power/apm-acpi.rst>
24992dc98fd3SMichael Witten	  and the Battery Powered Linux mini-HOWTO, available from
2500e279b6c1SSam Ravnborg	  <http://www.tldp.org/docs.html#howto>.
2501e279b6c1SSam Ravnborg
2502e279b6c1SSam Ravnborg	  This driver does not spin down disk drives (see the hdparm(8)
2503e279b6c1SSam Ravnborg	  manpage ("man 8 hdparm") for that), and it doesn't turn off
2504e279b6c1SSam Ravnborg	  VESA-compliant "green" monitors.
2505e279b6c1SSam Ravnborg
2506e279b6c1SSam Ravnborg	  This driver does not support the TI 4000M TravelMate and the ACER
2507e279b6c1SSam Ravnborg	  486/DX4/75 because they don't have compliant BIOSes. Many "green"
2508e279b6c1SSam Ravnborg	  desktop machines also don't have compliant BIOSes, and this driver
2509e279b6c1SSam Ravnborg	  may cause those machines to panic during the boot phase.
2510e279b6c1SSam Ravnborg
2511e279b6c1SSam Ravnborg	  Generally, if you don't have a battery in your machine, there isn't
2512e279b6c1SSam Ravnborg	  much point in using this driver and you should say N. If you get
2513e279b6c1SSam Ravnborg	  random kernel OOPSes or reboots that don't seem to be related to
2514e279b6c1SSam Ravnborg	  anything, try disabling/enabling this option (or disabling/enabling
2515e279b6c1SSam Ravnborg	  APM in your BIOS).
2516e279b6c1SSam Ravnborg
2517e279b6c1SSam Ravnborg	  Some other things you should try when experiencing seemingly random,
2518e279b6c1SSam Ravnborg	  "weird" problems:
2519e279b6c1SSam Ravnborg
2520e279b6c1SSam Ravnborg	  1) make sure that you have enough swap space and that it is
2521e279b6c1SSam Ravnborg	  enabled.
2522e279b6c1SSam Ravnborg	  2) pass the "no-hlt" option to the kernel
2523e279b6c1SSam Ravnborg	  3) switch on floating point emulation in the kernel and pass
2524e279b6c1SSam Ravnborg	  the "no387" option to the kernel
2525e279b6c1SSam Ravnborg	  4) pass the "floppy=nodma" option to the kernel
2526e279b6c1SSam Ravnborg	  5) pass the "mem=4M" option to the kernel (thereby disabling
2527e279b6c1SSam Ravnborg	  all but the first 4 MB of RAM)
2528e279b6c1SSam Ravnborg	  6) make sure that the CPU is not over clocked.
2529e279b6c1SSam Ravnborg	  7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/>
2530e279b6c1SSam Ravnborg	  8) disable the cache from your BIOS settings
2531e279b6c1SSam Ravnborg	  9) install a fan for the video card or exchange video RAM
2532e279b6c1SSam Ravnborg	  10) install a better fan for the CPU
2533e279b6c1SSam Ravnborg	  11) exchange RAM chips
2534e279b6c1SSam Ravnborg	  12) exchange the motherboard.
2535e279b6c1SSam Ravnborg
2536e279b6c1SSam Ravnborg	  To compile this driver as a module, choose M here: the
2537e279b6c1SSam Ravnborg	  module will be called apm.
2538e279b6c1SSam Ravnborg
2539e279b6c1SSam Ravnborgif APM
2540e279b6c1SSam Ravnborg
2541e279b6c1SSam Ravnborgconfig APM_IGNORE_USER_SUSPEND
2542e279b6c1SSam Ravnborg	bool "Ignore USER SUSPEND"
2543a7f7f624SMasahiro Yamada	help
2544e279b6c1SSam Ravnborg	  This option will ignore USER SUSPEND requests. On machines with a
2545e279b6c1SSam Ravnborg	  compliant APM BIOS, you want to say N. However, on the NEC Versa M
2546e279b6c1SSam Ravnborg	  series notebooks, it is necessary to say Y because of a BIOS bug.
2547e279b6c1SSam Ravnborg
2548e279b6c1SSam Ravnborgconfig APM_DO_ENABLE
2549e279b6c1SSam Ravnborg	bool "Enable PM at boot time"
2550a7f7f624SMasahiro Yamada	help
2551e279b6c1SSam Ravnborg	  Enable APM features at boot time. From page 36 of the APM BIOS
2552e279b6c1SSam Ravnborg	  specification: "When disabled, the APM BIOS does not automatically
2553e279b6c1SSam Ravnborg	  power manage devices, enter the Standby State, enter the Suspend
2554e279b6c1SSam Ravnborg	  State, or take power saving steps in response to CPU Idle calls."
2555e279b6c1SSam Ravnborg	  This driver will make CPU Idle calls when Linux is idle (unless this
2556e279b6c1SSam Ravnborg	  feature is turned off -- see "Do CPU IDLE calls", below). This
2557e279b6c1SSam Ravnborg	  should always save battery power, but more complicated APM features
2558e279b6c1SSam Ravnborg	  will be dependent on your BIOS implementation. You may need to turn
2559e279b6c1SSam Ravnborg	  this option off if your computer hangs at boot time when using APM
2560e279b6c1SSam Ravnborg	  support, or if it beeps continuously instead of suspending. Turn
2561e279b6c1SSam Ravnborg	  this off if you have a NEC UltraLite Versa 33/C or a Toshiba
2562e279b6c1SSam Ravnborg	  T400CDT. This is off by default since most machines do fine without
2563e279b6c1SSam Ravnborg	  this feature.
2564e279b6c1SSam Ravnborg
2565e279b6c1SSam Ravnborgconfig APM_CPU_IDLE
2566dd8af076SLen Brown	depends on CPU_IDLE
2567e279b6c1SSam Ravnborg	bool "Make CPU Idle calls when idle"
2568a7f7f624SMasahiro Yamada	help
2569e279b6c1SSam Ravnborg	  Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop.
2570e279b6c1SSam Ravnborg	  On some machines, this can activate improved power savings, such as
2571e279b6c1SSam Ravnborg	  a slowed CPU clock rate, when the machine is idle. These idle calls
2572e279b6c1SSam Ravnborg	  are made after the idle loop has run for some length of time (e.g.,
2573e279b6c1SSam Ravnborg	  333 mS). On some machines, this will cause a hang at boot time or
2574e279b6c1SSam Ravnborg	  whenever the CPU becomes idle. (On machines with more than one CPU,
2575e279b6c1SSam Ravnborg	  this option does nothing.)
2576e279b6c1SSam Ravnborg
2577e279b6c1SSam Ravnborgconfig APM_DISPLAY_BLANK
2578e279b6c1SSam Ravnborg	bool "Enable console blanking using APM"
2579a7f7f624SMasahiro Yamada	help
2580e279b6c1SSam Ravnborg	  Enable console blanking using the APM. Some laptops can use this to
2581e279b6c1SSam Ravnborg	  turn off the LCD backlight when the screen blanker of the Linux
2582e279b6c1SSam Ravnborg	  virtual console blanks the screen. Note that this is only used by
2583e279b6c1SSam Ravnborg	  the virtual console screen blanker, and won't turn off the backlight
2584e279b6c1SSam Ravnborg	  when using the X Window system. This also doesn't have anything to
2585e279b6c1SSam Ravnborg	  do with your VESA-compliant power-saving monitor. Further, this
2586e279b6c1SSam Ravnborg	  option doesn't work for all laptops -- it might not turn off your
2587e279b6c1SSam Ravnborg	  backlight at all, or it might print a lot of errors to the console,
2588e279b6c1SSam Ravnborg	  especially if you are using gpm.
2589e279b6c1SSam Ravnborg
2590e279b6c1SSam Ravnborgconfig APM_ALLOW_INTS
2591e279b6c1SSam Ravnborg	bool "Allow interrupts during APM BIOS calls"
2592a7f7f624SMasahiro Yamada	help
2593e279b6c1SSam Ravnborg	  Normally we disable external interrupts while we are making calls to
2594e279b6c1SSam Ravnborg	  the APM BIOS as a measure to lessen the effects of a badly behaving
2595e279b6c1SSam Ravnborg	  BIOS implementation.  The BIOS should reenable interrupts if it
2596e279b6c1SSam Ravnborg	  needs to.  Unfortunately, some BIOSes do not -- especially those in
2597e279b6c1SSam Ravnborg	  many of the newer IBM Thinkpads.  If you experience hangs when you
2598e279b6c1SSam Ravnborg	  suspend, try setting this to Y.  Otherwise, say N.
2599e279b6c1SSam Ravnborg
2600e279b6c1SSam Ravnborgendif # APM
2601e279b6c1SSam Ravnborg
2602bb0a56ecSDave Jonessource "drivers/cpufreq/Kconfig"
2603e279b6c1SSam Ravnborg
2604e279b6c1SSam Ravnborgsource "drivers/cpuidle/Kconfig"
2605e279b6c1SSam Ravnborg
260627471fdbSAndy Henroidsource "drivers/idle/Kconfig"
260727471fdbSAndy Henroid
2608e279b6c1SSam Ravnborgendmenu
2609e279b6c1SSam Ravnborg
2610e279b6c1SSam Ravnborg
2611e279b6c1SSam Ravnborgmenu "Bus options (PCI etc.)"
2612e279b6c1SSam Ravnborg
2613e279b6c1SSam Ravnborgchoice
2614e279b6c1SSam Ravnborg	prompt "PCI access mode"
2615efefa6f6SIngo Molnar	depends on X86_32 && PCI
2616e279b6c1SSam Ravnborg	default PCI_GOANY
2617a7f7f624SMasahiro Yamada	help
2618e279b6c1SSam Ravnborg	  On PCI systems, the BIOS can be used to detect the PCI devices and
2619e279b6c1SSam Ravnborg	  determine their configuration. However, some old PCI motherboards
2620e279b6c1SSam Ravnborg	  have BIOS bugs and may crash if this is done. Also, some embedded
2621e279b6c1SSam Ravnborg	  PCI-based systems don't have any BIOS at all. Linux can also try to
2622e279b6c1SSam Ravnborg	  detect the PCI hardware directly without using the BIOS.
2623e279b6c1SSam Ravnborg
2624e279b6c1SSam Ravnborg	  With this option, you can specify how Linux should detect the
2625e279b6c1SSam Ravnborg	  PCI devices. If you choose "BIOS", the BIOS will be used,
2626e279b6c1SSam Ravnborg	  if you choose "Direct", the BIOS won't be used, and if you
2627e279b6c1SSam Ravnborg	  choose "MMConfig", then PCI Express MMCONFIG will be used.
2628e279b6c1SSam Ravnborg	  If you choose "Any", the kernel will try MMCONFIG, then the
2629e279b6c1SSam Ravnborg	  direct access method and falls back to the BIOS if that doesn't
2630e279b6c1SSam Ravnborg	  work. If unsure, go with the default, which is "Any".
2631e279b6c1SSam Ravnborg
2632e279b6c1SSam Ravnborgconfig PCI_GOBIOS
2633e279b6c1SSam Ravnborg	bool "BIOS"
2634e279b6c1SSam Ravnborg
2635e279b6c1SSam Ravnborgconfig PCI_GOMMCONFIG
2636e279b6c1SSam Ravnborg	bool "MMConfig"
2637e279b6c1SSam Ravnborg
2638e279b6c1SSam Ravnborgconfig PCI_GODIRECT
2639e279b6c1SSam Ravnborg	bool "Direct"
2640e279b6c1SSam Ravnborg
26413ef0e1f8SAndres Salomonconfig PCI_GOOLPC
264276fb6570SDaniel Drake	bool "OLPC XO-1"
26433ef0e1f8SAndres Salomon	depends on OLPC
26443ef0e1f8SAndres Salomon
26452bdd1b03SAndres Salomonconfig PCI_GOANY
26462bdd1b03SAndres Salomon	bool "Any"
26472bdd1b03SAndres Salomon
2648e279b6c1SSam Ravnborgendchoice
2649e279b6c1SSam Ravnborg
2650e279b6c1SSam Ravnborgconfig PCI_BIOS
26513c2362e6SHarvey Harrison	def_bool y
2652efefa6f6SIngo Molnar	depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY)
2653e279b6c1SSam Ravnborg
2654e279b6c1SSam Ravnborg# x86-64 doesn't support PCI BIOS access from long mode so always go direct.
2655e279b6c1SSam Ravnborgconfig PCI_DIRECT
26563c2362e6SHarvey Harrison	def_bool y
26570aba496fSShaohua Li	depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC || PCI_GOMMCONFIG))
2658e279b6c1SSam Ravnborg
2659e279b6c1SSam Ravnborgconfig PCI_MMCONFIG
2660b45c9f36SJan Kiszka	bool "Support mmconfig PCI config space access" if X86_64
2661b45c9f36SJan Kiszka	default y
26628364e1f8SJan Kiszka	depends on PCI && (ACPI || SFI || JAILHOUSE_GUEST)
2663b45c9f36SJan Kiszka	depends on X86_64 || (PCI_GOANY || PCI_GOMMCONFIG)
2664e279b6c1SSam Ravnborg
26653ef0e1f8SAndres Salomonconfig PCI_OLPC
26662bdd1b03SAndres Salomon	def_bool y
26672bdd1b03SAndres Salomon	depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY)
26683ef0e1f8SAndres Salomon
2669b5401a96SAlex Nixonconfig PCI_XEN
2670b5401a96SAlex Nixon	def_bool y
2671b5401a96SAlex Nixon	depends on PCI && XEN
2672b5401a96SAlex Nixon	select SWIOTLB_XEN
2673b5401a96SAlex Nixon
26748364e1f8SJan Kiszkaconfig MMCONF_FAM10H
26758364e1f8SJan Kiszka	def_bool y
26768364e1f8SJan Kiszka	depends on X86_64 && PCI_MMCONFIG && ACPI
2677e279b6c1SSam Ravnborg
26783f6ea84aSIra W. Snyderconfig PCI_CNB20LE_QUIRK
26796a108a14SDavid Rientjes	bool "Read CNB20LE Host Bridge Windows" if EXPERT
26806ea30386SKees Cook	depends on PCI
26813f6ea84aSIra W. Snyder	help
26823f6ea84aSIra W. Snyder	  Read the PCI windows out of the CNB20LE host bridge. This allows
26833f6ea84aSIra W. Snyder	  PCI hotplug to work on systems with the CNB20LE chipset which do
26843f6ea84aSIra W. Snyder	  not have ACPI.
26853f6ea84aSIra W. Snyder
268664a5fed6SBjorn Helgaas	  There's no public spec for this chipset, and this functionality
268764a5fed6SBjorn Helgaas	  is known to be incomplete.
268864a5fed6SBjorn Helgaas
268964a5fed6SBjorn Helgaas	  You should say N unless you know you need this.
269064a5fed6SBjorn Helgaas
26913a495511SWilliam Breathitt Grayconfig ISA_BUS
269217a2a129SWilliam Breathitt Gray	bool "ISA bus support on modern systems" if EXPERT
26933a495511SWilliam Breathitt Gray	help
269417a2a129SWilliam Breathitt Gray	  Expose ISA bus device drivers and options available for selection and
269517a2a129SWilliam Breathitt Gray	  configuration. Enable this option if your target machine has an ISA
269617a2a129SWilliam Breathitt Gray	  bus. ISA is an older system, displaced by PCI and newer bus
269717a2a129SWilliam Breathitt Gray	  architectures -- if your target machine is modern, it probably does
269817a2a129SWilliam Breathitt Gray	  not have an ISA bus.
26993a495511SWilliam Breathitt Gray
27003a495511SWilliam Breathitt Gray	  If unsure, say N.
27013a495511SWilliam Breathitt Gray
27021c00f016SDavid Rientjes# x86_64 have no ISA slots, but can have ISA-style DMA.
2703e279b6c1SSam Ravnborgconfig ISA_DMA_API
27041c00f016SDavid Rientjes	bool "ISA-style DMA support" if (X86_64 && EXPERT)
27051c00f016SDavid Rientjes	default y
27061c00f016SDavid Rientjes	help
27071c00f016SDavid Rientjes	  Enables ISA-style DMA support for devices requiring such controllers.
27081c00f016SDavid Rientjes	  If unsure, say Y.
2709e279b6c1SSam Ravnborg
271051e68d05SLinus Torvaldsif X86_32
271151e68d05SLinus Torvalds
2712e279b6c1SSam Ravnborgconfig ISA
2713e279b6c1SSam Ravnborg	bool "ISA support"
2714a7f7f624SMasahiro Yamada	help
2715e279b6c1SSam Ravnborg	  Find out whether you have ISA slots on your motherboard.  ISA is the
2716e279b6c1SSam Ravnborg	  name of a bus system, i.e. the way the CPU talks to the other stuff
2717e279b6c1SSam Ravnborg	  inside your box.  Other bus systems are PCI, EISA, MicroChannel
2718e279b6c1SSam Ravnborg	  (MCA) or VESA.  ISA is an older system, now being displaced by PCI;
2719e279b6c1SSam Ravnborg	  newer boards don't support it.  If you have ISA, say Y, otherwise N.
2720e279b6c1SSam Ravnborg
2721e279b6c1SSam Ravnborgconfig SCx200
2722e279b6c1SSam Ravnborg	tristate "NatSemi SCx200 support"
2723a7f7f624SMasahiro Yamada	help
2724e279b6c1SSam Ravnborg	  This provides basic support for National Semiconductor's
2725e279b6c1SSam Ravnborg	  (now AMD's) Geode processors.  The driver probes for the
2726e279b6c1SSam Ravnborg	  PCI-IDs of several on-chip devices, so its a good dependency
2727e279b6c1SSam Ravnborg	  for other scx200_* drivers.
2728e279b6c1SSam Ravnborg
2729e279b6c1SSam Ravnborg	  If compiled as a module, the driver is named scx200.
2730e279b6c1SSam Ravnborg
2731e279b6c1SSam Ravnborgconfig SCx200HR_TIMER
2732e279b6c1SSam Ravnborg	tristate "NatSemi SCx200 27MHz High-Resolution Timer Support"
2733592913ecSJohn Stultz	depends on SCx200
2734e279b6c1SSam Ravnborg	default y
2735a7f7f624SMasahiro Yamada	help
2736e279b6c1SSam Ravnborg	  This driver provides a clocksource built upon the on-chip
2737e279b6c1SSam Ravnborg	  27MHz high-resolution timer.  Its also a workaround for
2738e279b6c1SSam Ravnborg	  NSC Geode SC-1100's buggy TSC, which loses time when the
2739e279b6c1SSam Ravnborg	  processor goes idle (as is done by the scheduler).  The
2740e279b6c1SSam Ravnborg	  other workaround is idle=poll boot option.
2741e279b6c1SSam Ravnborg
27423ef0e1f8SAndres Salomonconfig OLPC
27433ef0e1f8SAndres Salomon	bool "One Laptop Per Child support"
274454008979SThomas Gleixner	depends on !X86_PAE
27453c554946SAndres Salomon	select GPIOLIB
2746dc3119e7SThomas Gleixner	select OF
274745bb1674SDaniel Drake	select OF_PROMTREE
2748b4e51854SGrant Likely	select IRQ_DOMAIN
27490c3d931bSLubomir Rintel	select OLPC_EC
2750a7f7f624SMasahiro Yamada	help
27513ef0e1f8SAndres Salomon	  Add support for detecting the unique features of the OLPC
27523ef0e1f8SAndres Salomon	  XO hardware.
27533ef0e1f8SAndres Salomon
2754a3128588SDaniel Drakeconfig OLPC_XO1_PM
2755a3128588SDaniel Drake	bool "OLPC XO-1 Power Management"
2756fa112cf1SBorislav Petkov	depends on OLPC && MFD_CS5535=y && PM_SLEEP
2757a7f7f624SMasahiro Yamada	help
275897c4cb71SDaniel Drake	  Add support for poweroff and suspend of the OLPC XO-1 laptop.
2759bf1ebf00SDaniel Drake
2760cfee9597SDaniel Drakeconfig OLPC_XO1_RTC
2761cfee9597SDaniel Drake	bool "OLPC XO-1 Real Time Clock"
2762cfee9597SDaniel Drake	depends on OLPC_XO1_PM && RTC_DRV_CMOS
2763a7f7f624SMasahiro Yamada	help
2764cfee9597SDaniel Drake	  Add support for the XO-1 real time clock, which can be used as a
2765cfee9597SDaniel Drake	  programmable wakeup source.
2766cfee9597SDaniel Drake
27677feda8e9SDaniel Drakeconfig OLPC_XO1_SCI
27687feda8e9SDaniel Drake	bool "OLPC XO-1 SCI extras"
276992e830f2SArnd Bergmann	depends on OLPC && OLPC_XO1_PM && GPIO_CS5535=y
2770ed8e47feSRandy Dunlap	depends on INPUT=y
2771d8d01a63SDaniel Drake	select POWER_SUPPLY
2772a7f7f624SMasahiro Yamada	help
27737feda8e9SDaniel Drake	  Add support for SCI-based features of the OLPC XO-1 laptop:
27747bc74b3dSDaniel Drake	   - EC-driven system wakeups
27757feda8e9SDaniel Drake	   - Power button
27767bc74b3dSDaniel Drake	   - Ebook switch
27772cf2baeaSDaniel Drake	   - Lid switch
2778e1040ac6SDaniel Drake	   - AC adapter status updates
2779e1040ac6SDaniel Drake	   - Battery status updates
27807feda8e9SDaniel Drake
2781a0f30f59SDaniel Drakeconfig OLPC_XO15_SCI
2782a0f30f59SDaniel Drake	bool "OLPC XO-1.5 SCI extras"
2783d8d01a63SDaniel Drake	depends on OLPC && ACPI
2784d8d01a63SDaniel Drake	select POWER_SUPPLY
2785a7f7f624SMasahiro Yamada	help
2786a0f30f59SDaniel Drake	  Add support for SCI-based features of the OLPC XO-1.5 laptop:
2787a0f30f59SDaniel Drake	   - EC-driven system wakeups
2788a0f30f59SDaniel Drake	   - AC adapter status updates
2789a0f30f59SDaniel Drake	   - Battery status updates
2790e279b6c1SSam Ravnborg
2791d4f3e350SEd Wildgooseconfig ALIX
2792d4f3e350SEd Wildgoose	bool "PCEngines ALIX System Support (LED setup)"
2793d4f3e350SEd Wildgoose	select GPIOLIB
2794a7f7f624SMasahiro Yamada	help
2795d4f3e350SEd Wildgoose	  This option enables system support for the PCEngines ALIX.
2796d4f3e350SEd Wildgoose	  At present this just sets up LEDs for GPIO control on
2797d4f3e350SEd Wildgoose	  ALIX2/3/6 boards.  However, other system specific setup should
2798d4f3e350SEd Wildgoose	  get added here.
2799d4f3e350SEd Wildgoose
2800d4f3e350SEd Wildgoose	  Note: You must still enable the drivers for GPIO and LED support
2801d4f3e350SEd Wildgoose	  (GPIO_CS5535 & LEDS_GPIO) to actually use the LEDs
2802d4f3e350SEd Wildgoose
2803d4f3e350SEd Wildgoose	  Note: You have to set alix.force=1 for boards with Award BIOS.
2804d4f3e350SEd Wildgoose
2805da4e3302SPhilip Prindevilleconfig NET5501
2806da4e3302SPhilip Prindeville	bool "Soekris Engineering net5501 System Support (LEDS, GPIO, etc)"
2807da4e3302SPhilip Prindeville	select GPIOLIB
2808a7f7f624SMasahiro Yamada	help
2809da4e3302SPhilip Prindeville	  This option enables system support for the Soekris Engineering net5501.
2810da4e3302SPhilip Prindeville
28113197059aSPhilip A. Prindevilleconfig GEOS
28123197059aSPhilip A. Prindeville	bool "Traverse Technologies GEOS System Support (LEDS, GPIO, etc)"
28133197059aSPhilip A. Prindeville	select GPIOLIB
28143197059aSPhilip A. Prindeville	depends on DMI
2815a7f7f624SMasahiro Yamada	help
28163197059aSPhilip A. Prindeville	  This option enables system support for the Traverse Technologies GEOS.
28173197059aSPhilip A. Prindeville
28187d029125SVivien Didelotconfig TS5500
28197d029125SVivien Didelot	bool "Technologic Systems TS-5500 platform support"
28207d029125SVivien Didelot	depends on MELAN
28217d029125SVivien Didelot	select CHECK_SIGNATURE
28227d029125SVivien Didelot	select NEW_LEDS
28237d029125SVivien Didelot	select LEDS_CLASS
2824a7f7f624SMasahiro Yamada	help
28257d029125SVivien Didelot	  This option enables system support for the Technologic Systems TS-5500.
28267d029125SVivien Didelot
2827e279b6c1SSam Ravnborgendif # X86_32
2828e279b6c1SSam Ravnborg
282923ac4ae8SAndreas Herrmannconfig AMD_NB
2830e279b6c1SSam Ravnborg	def_bool y
28310e152cd7SBorislav Petkov	depends on CPU_SUP_AMD && PCI
2832e279b6c1SSam Ravnborg
2833e3263ab3SDavid Herrmannconfig X86_SYSFB
2834e3263ab3SDavid Herrmann	bool "Mark VGA/VBE/EFI FB as generic system framebuffer"
2835e3263ab3SDavid Herrmann	help
2836e3263ab3SDavid Herrmann	  Firmwares often provide initial graphics framebuffers so the BIOS,
2837e3263ab3SDavid Herrmann	  bootloader or kernel can show basic video-output during boot for
2838e3263ab3SDavid Herrmann	  user-guidance and debugging. Historically, x86 used the VESA BIOS
2839e3263ab3SDavid Herrmann	  Extensions and EFI-framebuffers for this, which are mostly limited
2840e3263ab3SDavid Herrmann	  to x86.
2841e3263ab3SDavid Herrmann	  This option, if enabled, marks VGA/VBE/EFI framebuffers as generic
2842e3263ab3SDavid Herrmann	  framebuffers so the new generic system-framebuffer drivers can be
2843e3263ab3SDavid Herrmann	  used on x86. If the framebuffer is not compatible with the generic
2844e3a5dc08SNikolas Nyby	  modes, it is advertised as fallback platform framebuffer so legacy
2845e3263ab3SDavid Herrmann	  drivers like efifb, vesafb and uvesafb can pick it up.
2846e3263ab3SDavid Herrmann	  If this option is not selected, all system framebuffers are always
2847e3263ab3SDavid Herrmann	  marked as fallback platform framebuffers as usual.
2848e3263ab3SDavid Herrmann
2849e3263ab3SDavid Herrmann	  Note: Legacy fbdev drivers, including vesafb, efifb, uvesafb, will
2850e3263ab3SDavid Herrmann	  not be able to pick up generic system framebuffers if this option
2851e3263ab3SDavid Herrmann	  is selected. You are highly encouraged to enable simplefb as
2852e3263ab3SDavid Herrmann	  replacement if you select this option. simplefb can correctly deal
2853e3263ab3SDavid Herrmann	  with generic system framebuffers. But you should still keep vesafb
2854e3263ab3SDavid Herrmann	  and others enabled as fallback if a system framebuffer is
2855e3263ab3SDavid Herrmann	  incompatible with simplefb.
2856e3263ab3SDavid Herrmann
2857e3263ab3SDavid Herrmann	  If unsure, say Y.
2858e3263ab3SDavid Herrmann
2859e279b6c1SSam Ravnborgendmenu
2860e279b6c1SSam Ravnborg
2861e279b6c1SSam Ravnborg
28621572497cSChristoph Hellwigmenu "Binary Emulations"
2863e279b6c1SSam Ravnborg
2864e279b6c1SSam Ravnborgconfig IA32_EMULATION
2865e279b6c1SSam Ravnborg	bool "IA32 Emulation"
2866e279b6c1SSam Ravnborg	depends on X86_64
286739f88911SIngo Molnar	select ARCH_WANT_OLD_COMPAT_IPC
2868d1603990SRandy Dunlap	select BINFMT_ELF
2869a97f52e6SRoland McGrath	select COMPAT_BINFMT_ELF
287039f88911SIngo Molnar	select COMPAT_OLD_SIGACTION
2871a7f7f624SMasahiro Yamada	help
28725fd92e65SH. J. Lu	  Include code to run legacy 32-bit programs under a
28735fd92e65SH. J. Lu	  64-bit kernel. You should likely turn this on, unless you're
28745fd92e65SH. J. Lu	  100% sure that you don't have any 32-bit programs left.
2875e279b6c1SSam Ravnborg
2876e279b6c1SSam Ravnborgconfig IA32_AOUT
2877e279b6c1SSam Ravnborg	tristate "IA32 a.out support"
28786b213e1bSDavid Woodhouse	depends on IA32_EMULATION
2879eac61655SBorislav Petkov	depends on BROKEN
2880a7f7f624SMasahiro Yamada	help
2881e279b6c1SSam Ravnborg	  Support old a.out binaries in the 32bit emulation.
2882e279b6c1SSam Ravnborg
28830bf62763SH. Peter Anvinconfig X86_X32
28846ea30386SKees Cook	bool "x32 ABI for 64-bit mode"
28859b54050bSBrian Gerst	depends on X86_64
2886a7f7f624SMasahiro Yamada	help
28875fd92e65SH. J. Lu	  Include code to run binaries for the x32 native 32-bit ABI
28885fd92e65SH. J. Lu	  for 64-bit processors.  An x32 process gets access to the
28895fd92e65SH. J. Lu	  full 64-bit register file and wide data path while leaving
28905fd92e65SH. J. Lu	  pointers at 32 bits for smaller memory footprint.
28915fd92e65SH. J. Lu
28925fd92e65SH. J. Lu	  You will need a recent binutils (2.22 or later) with
28935fd92e65SH. J. Lu	  elf32_x86_64 support enabled to compile a kernel with this
28945fd92e65SH. J. Lu	  option set.
28955fd92e65SH. J. Lu
2896953fee1dSIngo Molnarconfig COMPAT_32
2897953fee1dSIngo Molnar	def_bool y
2898953fee1dSIngo Molnar	depends on IA32_EMULATION || X86_32
2899953fee1dSIngo Molnar	select HAVE_UID16
2900953fee1dSIngo Molnar	select OLD_SIGSUSPEND3
2901953fee1dSIngo Molnar
2902e279b6c1SSam Ravnborgconfig COMPAT
29033c2362e6SHarvey Harrison	def_bool y
29040bf62763SH. Peter Anvin	depends on IA32_EMULATION || X86_X32
2905e279b6c1SSam Ravnborg
29063120e25eSJan Beulichif COMPAT
2907e279b6c1SSam Ravnborgconfig COMPAT_FOR_U64_ALIGNMENT
29083120e25eSJan Beulich	def_bool y
2909e279b6c1SSam Ravnborg
2910e279b6c1SSam Ravnborgconfig SYSVIPC_COMPAT
29113c2362e6SHarvey Harrison	def_bool y
29123120e25eSJan Beulich	depends on SYSVIPC
29133120e25eSJan Beulichendif
2914ee009e4aSDavid Howells
2915e279b6c1SSam Ravnborgendmenu
2916e279b6c1SSam Ravnborg
2917e279b6c1SSam Ravnborg
2918e5beae16SKeith Packardconfig HAVE_ATOMIC_IOMAP
2919e5beae16SKeith Packard	def_bool y
2920e5beae16SKeith Packard	depends on X86_32
2921e5beae16SKeith Packard
2922e279b6c1SSam Ravnborgsource "drivers/firmware/Kconfig"
2923e279b6c1SSam Ravnborg
2924edf88417SAvi Kivitysource "arch/x86/kvm/Kconfig"
29255e8ebd84SJason A. Donenfeld
29265e8ebd84SJason A. Donenfeldsource "arch/x86/Kconfig.assembler"
2927