xref: /linux/arch/x86/Kconfig (revision 14df32670291588036a498051a54cd8462d7f611)
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
22daa93fabSSam Ravnborg
23daa93fabSSam Ravnborgconfig X86_64
243120e25eSJan Beulich	def_bool y
253120e25eSJan Beulich	depends on 64BIT
26d94e0685SIngo Molnar	# Options that are inherently 64-bit kernel only:
274eb0716eSAlexandre Ghiti	select ARCH_HAS_GIGANTIC_PAGE
28c12d3362SArd Biesheuvel	select ARCH_SUPPORTS_INT128 if CC_HAS_INT128
29d94e0685SIngo Molnar	select ARCH_USE_CMPXCHG_LOCKREF
30d94e0685SIngo Molnar	select HAVE_ARCH_SOFT_DIRTY
31d94e0685SIngo Molnar	select MODULES_USE_ELF_RELA
32f616ab59SChristoph Hellwig	select NEED_DMA_MAP_STATE
3309230cbcSChristoph Hellwig	select SWIOTLB
341032c0baSSam Ravnborg
35518049d9SSteven Rostedt (VMware)config FORCE_DYNAMIC_FTRACE
36518049d9SSteven Rostedt (VMware)	def_bool y
37518049d9SSteven Rostedt (VMware)	depends on X86_32
38518049d9SSteven Rostedt (VMware)	depends on FUNCTION_TRACER
39518049d9SSteven Rostedt (VMware)	select DYNAMIC_FTRACE
40518049d9SSteven Rostedt (VMware)	help
41518049d9SSteven Rostedt (VMware)	 We keep the static function tracing (!DYNAMIC_FTRACE) around
42518049d9SSteven Rostedt (VMware)	 in order to test the non static function tracing in the
43518049d9SSteven Rostedt (VMware)	 generic code, as other architectures still use it. But we
44518049d9SSteven Rostedt (VMware)	 only need to keep it around for x86_64. No need to keep it
45518049d9SSteven Rostedt (VMware)	 for x86_32. For x86_32, force DYNAMIC_FTRACE.
46d94e0685SIngo Molnar#
47d94e0685SIngo Molnar# Arch settings
48d94e0685SIngo Molnar#
49d94e0685SIngo Molnar# ( Note that options that are marked 'if X86_64' could in principle be
50d94e0685SIngo Molnar#   ported to 32-bit as well. )
51d94e0685SIngo Molnar#
528d5fffb9SSam Ravnborgconfig X86
533c2362e6SHarvey Harrison	def_bool y
54c763ea26SIngo Molnar	#
55c763ea26SIngo Molnar	# Note: keep this list sorted alphabetically
56c763ea26SIngo Molnar	#
576471b825SIngo Molnar	select ACPI_LEGACY_TABLES_LOOKUP	if ACPI
586e0a0ea1SGraeme Gregory	select ACPI_SYSTEM_POWER_STATES_SUPPORT	if ACPI
59942fa985SYury Norov	select ARCH_32BIT_OFF_T			if X86_32
602a21ad57SThomas Gleixner	select ARCH_CLOCKSOURCE_INIT
6191dda51aSAleksey Makarov	select ARCH_HAS_ACPI_TABLE_UPGRADE	if ACPI
62fa5b6ec9SLaura Abbott	select ARCH_HAS_DEBUG_VIRTUAL
63399145f9SAnshuman Khandual	select ARCH_HAS_DEBUG_VM_PGTABLE	if !X86_PAE
6421266be9SDan Williams	select ARCH_HAS_DEVMEM_IS_ALLOWED
65b1a57bbfSDouglas Anderson	select ARCH_HAS_EARLY_DEBUG		if KGDB
666471b825SIngo Molnar	select ARCH_HAS_ELF_RANDOMIZE
6772d93104SLinus Torvalds	select ARCH_HAS_FAST_MULTIPLIER
68316d097cSDave Hansen	select ARCH_HAS_FILTER_PGPROT
696974f0c4SDaniel Micay	select ARCH_HAS_FORTIFY_SOURCE
70957e3facSRiku Voipio	select ARCH_HAS_GCOV_PROFILE_ALL
710f1441b4SPeter Zijlstra	select ARCH_HAS_KCOV			if X86_64 && STACK_VALIDATION
720c9c1d56SThiago Jung Bauermann	select ARCH_HAS_MEM_ENCRYPT
7310bcc80eSMathieu Desnoyers	select ARCH_HAS_MEMBARRIER_SYNC_CORE
740ebeea8cSDaniel Borkmann	select ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE
75c763ea26SIngo Molnar	select ARCH_HAS_PMEM_API		if X86_64
7617596731SRobin Murphy	select ARCH_HAS_PTE_DEVMAP		if X86_64
773010a5eaSLaurent Dufour	select ARCH_HAS_PTE_SPECIAL
780aed55afSDan Williams	select ARCH_HAS_UACCESS_FLUSHCACHE	if X86_64
79ec6347bbSDan Williams	select ARCH_HAS_COPY_MC			if X86_64
80d2852a22SDaniel Borkmann	select ARCH_HAS_SET_MEMORY
81d253ca0cSRick Edgecombe	select ARCH_HAS_SET_DIRECT_MAP
82ad21fc4fSLaura Abbott	select ARCH_HAS_STRICT_KERNEL_RWX
83ad21fc4fSLaura Abbott	select ARCH_HAS_STRICT_MODULE_RWX
84ac1ab12aSMathieu Desnoyers	select ARCH_HAS_SYNC_CORE_BEFORE_USERMODE
8525c619e5SBrian Gerst	select ARCH_HAS_SYSCALL_WRAPPER
86c6d30853SAndrey Ryabinin	select ARCH_HAS_UBSAN_SANITIZE_ALL
877e01ccb4SZong Li	select ARCH_HAS_DEBUG_WX
886471b825SIngo Molnar	select ARCH_HAVE_NMI_SAFE_CMPXCHG
896471b825SIngo Molnar	select ARCH_MIGHT_HAVE_ACPI_PDC		if ACPI
9077fbbc81SMark Salter	select ARCH_MIGHT_HAVE_PC_PARPORT
915e2c18c0SMark Salter	select ARCH_MIGHT_HAVE_PC_SERIO
923599fe12SThomas Gleixner	select ARCH_STACKWALK
932c870e61SArnd Bergmann	select ARCH_SUPPORTS_ACPI
946471b825SIngo Molnar	select ARCH_SUPPORTS_ATOMIC_RMW
956471b825SIngo Molnar	select ARCH_SUPPORTS_NUMA_BALANCING	if X86_64
96*14df3267SThomas Gleixner	select ARCH_SUPPORTS_KMAP_LOCAL_FORCE_MAP	if NR_CPUS <= 4096
976471b825SIngo Molnar	select ARCH_USE_BUILTIN_BSWAP
986471b825SIngo Molnar	select ARCH_USE_QUEUED_RWLOCKS
996471b825SIngo Molnar	select ARCH_USE_QUEUED_SPINLOCKS
1002ce0d7f9SMark Brown	select ARCH_USE_SYM_ANNOTATIONS
101ce4a4e56SAndy Lutomirski	select ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH
10281c22041SDaniel Borkmann	select ARCH_WANT_DEFAULT_BPF_JIT	if X86_64
103c763ea26SIngo Molnar	select ARCH_WANTS_DYNAMIC_TASK_STRUCT
1043876d4a3SAlexandre Ghiti	select ARCH_WANT_HUGE_PMD_SHARE
10538d8b4e6SHuang Ying	select ARCH_WANTS_THP_SWAP		if X86_64
10610916706SShile Zhang	select BUILDTIME_TABLE_SORT
1076471b825SIngo Molnar	select CLKEVT_I8253
1086471b825SIngo Molnar	select CLOCKSOURCE_VALIDATE_LAST_CYCLE
1096471b825SIngo Molnar	select CLOCKSOURCE_WATCHDOG
1106471b825SIngo Molnar	select DCACHE_WORD_ACCESS
11145471cd9SLinus Torvalds	select EDAC_ATOMIC_SCRUB
11245471cd9SLinus Torvalds	select EDAC_SUPPORT
1136471b825SIngo Molnar	select GENERIC_CLOCKEVENTS
1146471b825SIngo Molnar	select GENERIC_CLOCKEVENTS_BROADCAST	if X86_64 || (X86_32 && X86_LOCAL_APIC)
1156471b825SIngo Molnar	select GENERIC_CLOCKEVENTS_MIN_ADJUST
1166471b825SIngo Molnar	select GENERIC_CMOS_UPDATE
1176471b825SIngo Molnar	select GENERIC_CPU_AUTOPROBE
11861dc0f55SThomas Gleixner	select GENERIC_CPU_VULNERABILITIES
1196471b825SIngo Molnar	select GENERIC_EARLY_IOREMAP
12027d6b4d1SThomas Gleixner	select GENERIC_ENTRY
1216471b825SIngo Molnar	select GENERIC_FIND_FIRST_BIT
1226471b825SIngo Molnar	select GENERIC_IOMAP
123c7d6c9ddSThomas Gleixner	select GENERIC_IRQ_EFFECTIVE_AFF_MASK	if SMP
1240fa115daSThomas Gleixner	select GENERIC_IRQ_MATRIX_ALLOCATOR	if X86_LOCAL_APIC
125ad7a929fSThomas Gleixner	select GENERIC_IRQ_MIGRATION		if SMP
1266471b825SIngo Molnar	select GENERIC_IRQ_PROBE
127c201c917SThomas Gleixner	select GENERIC_IRQ_RESERVATION_MODE
1286471b825SIngo Molnar	select GENERIC_IRQ_SHOW
1296471b825SIngo Molnar	select GENERIC_PENDING_IRQ		if SMP
1302ae27137SSteven Price	select GENERIC_PTDUMP
1316471b825SIngo Molnar	select GENERIC_SMP_IDLE_THREAD
1326471b825SIngo Molnar	select GENERIC_STRNCPY_FROM_USER
1336471b825SIngo Molnar	select GENERIC_STRNLEN_USER
1346471b825SIngo Molnar	select GENERIC_TIME_VSYSCALL
1357ac87074SVincenzo Frascino	select GENERIC_GETTIMEOFDAY
136550a77a7SDmitry Safonov	select GENERIC_VDSO_TIME_NS
13739656e83SChristoph Hellwig	select GUP_GET_PTE_LOW_HIGH		if X86_PAE
13817e5888eSHans de Goede	select HARDIRQS_SW_RESEND
1397edaeb68SThomas Gleixner	select HARDLOCKUP_CHECK_TIMESTAMP	if X86_64
1406471b825SIngo Molnar	select HAVE_ACPI_APEI			if ACPI
1416471b825SIngo Molnar	select HAVE_ACPI_APEI_NMI		if ACPI
1426471b825SIngo Molnar	select HAVE_ALIGNED_STRUCT_PAGE		if SLUB
1436471b825SIngo Molnar	select HAVE_ARCH_AUDITSYSCALL
1446471b825SIngo Molnar	select HAVE_ARCH_HUGE_VMAP		if X86_64 || X86_PAE
1456471b825SIngo Molnar	select HAVE_ARCH_JUMP_LABEL
146b34006c4SArd Biesheuvel	select HAVE_ARCH_JUMP_LABEL_RELATIVE
147d17a1d97SAndrey Ryabinin	select HAVE_ARCH_KASAN			if X86_64
1480609ae01SDaniel Axtens	select HAVE_ARCH_KASAN_VMALLOC		if X86_64
1496471b825SIngo Molnar	select HAVE_ARCH_KGDB
1509e08f57dSDaniel Cashman	select HAVE_ARCH_MMAP_RND_BITS		if MMU
1519e08f57dSDaniel Cashman	select HAVE_ARCH_MMAP_RND_COMPAT_BITS	if MMU && COMPAT
1521b028f78SDmitry Safonov	select HAVE_ARCH_COMPAT_MMAP_BASES	if MMU && COMPAT
153271ca788SArd Biesheuvel	select HAVE_ARCH_PREL32_RELOCATIONS
1546471b825SIngo Molnar	select HAVE_ARCH_SECCOMP_FILTER
155f7d83c1cSKees Cook	select HAVE_ARCH_THREAD_STRUCT_WHITELIST
156afaef01cSAlexander Popov	select HAVE_ARCH_STACKLEAK
1576471b825SIngo Molnar	select HAVE_ARCH_TRACEHOOK
1586471b825SIngo Molnar	select HAVE_ARCH_TRANSPARENT_HUGEPAGE
159a00cc7d9SMatthew Wilcox	select HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD if X86_64
160b64d8d1eSPeter Xu	select HAVE_ARCH_USERFAULTFD_WP         if X86_64 && USERFAULTFD
161e37e43a4SAndy Lutomirski	select HAVE_ARCH_VMAP_STACK		if X86_64
162c763ea26SIngo Molnar	select HAVE_ARCH_WITHIN_STACK_FRAMES
1632ff2b7ecSMasahiro Yamada	select HAVE_ASM_MODVERSIONS
1646471b825SIngo Molnar	select HAVE_CMPXCHG_DOUBLE
1656471b825SIngo Molnar	select HAVE_CMPXCHG_LOCAL
1666471b825SIngo Molnar	select HAVE_CONTEXT_TRACKING		if X86_64
1676471b825SIngo Molnar	select HAVE_C_RECORDMCOUNT
1686471b825SIngo Molnar	select HAVE_DEBUG_KMEMLEAK
1699c5a3621SAkinobu Mita	select HAVE_DMA_CONTIGUOUS
170677aa9f7SSteven Rostedt	select HAVE_DYNAMIC_FTRACE
17106aeaaeaSMasami Hiramatsu	select HAVE_DYNAMIC_FTRACE_WITH_REGS
172562955feSSteven Rostedt (VMware)	select HAVE_DYNAMIC_FTRACE_WITH_DIRECT_CALLS
17303f5781bSWang YanQing	select HAVE_EBPF_JIT
17458340a07SJohannes Berg	select HAVE_EFFICIENT_UNALIGNED_ACCESS
1756630a8e5SChristoph Hellwig	select HAVE_EISA
1765f56a5dfSJiri Slaby	select HAVE_EXIT_THREAD
17767a929e0SChristoph Hellwig	select HAVE_FAST_GUP
178644e0e8dSSteven Rostedt (VMware)	select HAVE_FENTRY			if X86_64 || DYNAMIC_FTRACE
1796471b825SIngo Molnar	select HAVE_FTRACE_MCOUNT_RECORD
1806471b825SIngo Molnar	select HAVE_FUNCTION_GRAPH_TRACER
1816471b825SIngo Molnar	select HAVE_FUNCTION_TRACER
1826b90bd4bSEmese Revfy	select HAVE_GCC_PLUGINS
1830067f129SK.Prasad	select HAVE_HW_BREAKPOINT
1846471b825SIngo Molnar	select HAVE_IDE
1856471b825SIngo Molnar	select HAVE_IOREMAP_PROT
1866471b825SIngo Molnar	select HAVE_IRQ_TIME_ACCOUNTING
1876471b825SIngo Molnar	select HAVE_KERNEL_BZIP2
1886471b825SIngo Molnar	select HAVE_KERNEL_GZIP
1896471b825SIngo Molnar	select HAVE_KERNEL_LZ4
1906471b825SIngo Molnar	select HAVE_KERNEL_LZMA
1916471b825SIngo Molnar	select HAVE_KERNEL_LZO
1926471b825SIngo Molnar	select HAVE_KERNEL_XZ
193fb46d057SNick Terrell	select HAVE_KERNEL_ZSTD
1946471b825SIngo Molnar	select HAVE_KPROBES
1956471b825SIngo Molnar	select HAVE_KPROBES_ON_FTRACE
196540adea3SMasami Hiramatsu	select HAVE_FUNCTION_ERROR_INJECTION
1976471b825SIngo Molnar	select HAVE_KRETPROBES
1986471b825SIngo Molnar	select HAVE_KVM
1996471b825SIngo Molnar	select HAVE_LIVEPATCH			if X86_64
2000102752eSFrederic Weisbecker	select HAVE_MIXED_BREAKPOINTS_REGS
201ee9f8fceSJosh Poimboeuf	select HAVE_MOD_ARCH_SPECIFIC
2029f132f7eSJoel Fernandes (Google)	select HAVE_MOVE_PMD
20342a0bb3fSPetr Mladek	select HAVE_NMI
2046471b825SIngo Molnar	select HAVE_OPROFILE
2056471b825SIngo Molnar	select HAVE_OPTPROBES
2066471b825SIngo Molnar	select HAVE_PCSPKR_PLATFORM
2076471b825SIngo Molnar	select HAVE_PERF_EVENTS
208c01d4323SFrederic Weisbecker	select HAVE_PERF_EVENTS_NMI
20992e5aae4SNicholas Piggin	select HAVE_HARDLOCKUP_DETECTOR_PERF	if PERF_EVENTS && HAVE_PERF_EVENTS_NMI
210eb01d42aSChristoph Hellwig	select HAVE_PCI
211c5e63197SJiri Olsa	select HAVE_PERF_REGS
212c5ebcedbSJiri Olsa	select HAVE_PERF_USER_STACK_DUMP
213ff2e6d72SPeter Zijlstra	select MMU_GATHER_RCU_TABLE_FREE		if PARAVIRT
21400998085SThomas Gleixner	select HAVE_POSIX_CPU_TIMERS_TASK_WORK
2156471b825SIngo Molnar	select HAVE_REGS_AND_STACK_ACCESS_API
2166415b38bSJiri Slaby	select HAVE_RELIABLE_STACKTRACE		if X86_64 && (UNWINDER_FRAME_POINTER || UNWINDER_ORC) && STACK_VALIDATION
2173c88ee19SMasami Hiramatsu	select HAVE_FUNCTION_ARG_ACCESS_API
218d148eac0SMasahiro Yamada	select HAVE_STACKPROTECTOR		if CC_HAS_SANE_STACKPROTECTOR
219c763ea26SIngo Molnar	select HAVE_STACK_VALIDATION		if X86_64
220e6d6c071SJosh Poimboeuf	select HAVE_STATIC_CALL
2211e7e4788SJosh Poimboeuf	select HAVE_STATIC_CALL_INLINE		if HAVE_STACK_VALIDATION
222d6761b8fSMathieu Desnoyers	select HAVE_RSEQ
2236471b825SIngo Molnar	select HAVE_SYSCALL_TRACEPOINTS
2246471b825SIngo Molnar	select HAVE_UNSTABLE_SCHED_CLOCK
2257c68af6eSAvi Kivity	select HAVE_USER_RETURN_NOTIFIER
2267ac87074SVincenzo Frascino	select HAVE_GENERIC_VDSO
22705736e4aSThomas Gleixner	select HOTPLUG_SMT			if SMP
228c0185808SThomas Gleixner	select IRQ_FORCED_THREADING
22986596f0aSChristoph Hellwig	select NEED_SG_DMA_LENGTH
2302eac9c2dSChristoph Hellwig	select PCI_DOMAINS			if PCI
231625210cfSSinan Kaya	select PCI_LOCKLESS_CONFIG		if PCI
2326471b825SIngo Molnar	select PERF_EVENTS
2333195ef59SPrarit Bhargava	select RTC_LIB
234d6faca40SArnd Bergmann	select RTC_MC146818_LIB
2356471b825SIngo Molnar	select SPARSE_IRQ
23683fe27eaSPranith Kumar	select SRCU
2371e7e4788SJosh Poimboeuf	select STACK_VALIDATION			if HAVE_STACK_VALIDATION && (HAVE_STATIC_CALL_INLINE || RETPOLINE)
2386471b825SIngo Molnar	select SYSCTL_EXCEPTION_TRACE
23915f4eae7SAndy Lutomirski	select THREAD_INFO_IN_TASK
2406471b825SIngo Molnar	select USER_STACKTRACE_SUPPORT
2416471b825SIngo Molnar	select VIRT_TO_BUS
2423b02a051SIngo Molnar	select HAVE_ARCH_KCSAN			if X86_64
2436471b825SIngo Molnar	select X86_FEATURE_NAMES		if PROC_FS
2440c608dadSAubrey Li	select PROC_PID_ARCH_STATUS		if PROC_FS
2459e2b4be3SNayna Jain	imply IMA_SECURE_AND_OR_TRUSTED_BOOT    if EFI
2467d8330a5SBalbir Singh
247ba7e4d13SIngo Molnarconfig INSTRUCTION_DECODER
2483120e25eSJan Beulich	def_bool y
2493120e25eSJan Beulich	depends on KPROBES || PERF_EVENTS || UPROBES
250ba7e4d13SIngo Molnar
25151b26adaSLinus Torvaldsconfig OUTPUT_FORMAT
25251b26adaSLinus Torvalds	string
25351b26adaSLinus Torvalds	default "elf32-i386" if X86_32
25451b26adaSLinus Torvalds	default "elf64-x86-64" if X86_64
25551b26adaSLinus Torvalds
2568d5fffb9SSam Ravnborgconfig LOCKDEP_SUPPORT
2573c2362e6SHarvey Harrison	def_bool y
2588d5fffb9SSam Ravnborg
2598d5fffb9SSam Ravnborgconfig STACKTRACE_SUPPORT
2603c2362e6SHarvey Harrison	def_bool y
2618d5fffb9SSam Ravnborg
2628d5fffb9SSam Ravnborgconfig MMU
2633c2362e6SHarvey Harrison	def_bool y
2648d5fffb9SSam Ravnborg
2659e08f57dSDaniel Cashmanconfig ARCH_MMAP_RND_BITS_MIN
2669e08f57dSDaniel Cashman	default 28 if 64BIT
2679e08f57dSDaniel Cashman	default 8
2689e08f57dSDaniel Cashman
2699e08f57dSDaniel Cashmanconfig ARCH_MMAP_RND_BITS_MAX
2709e08f57dSDaniel Cashman	default 32 if 64BIT
2719e08f57dSDaniel Cashman	default 16
2729e08f57dSDaniel Cashman
2739e08f57dSDaniel Cashmanconfig ARCH_MMAP_RND_COMPAT_BITS_MIN
2749e08f57dSDaniel Cashman	default 8
2759e08f57dSDaniel Cashman
2769e08f57dSDaniel Cashmanconfig ARCH_MMAP_RND_COMPAT_BITS_MAX
2779e08f57dSDaniel Cashman	default 16
2789e08f57dSDaniel Cashman
2798d5fffb9SSam Ravnborgconfig SBUS
2808d5fffb9SSam Ravnborg	bool
2818d5fffb9SSam Ravnborg
2828d5fffb9SSam Ravnborgconfig GENERIC_ISA_DMA
2833120e25eSJan Beulich	def_bool y
2843120e25eSJan Beulich	depends on ISA_DMA_API
2858d5fffb9SSam Ravnborg
2868d5fffb9SSam Ravnborgconfig GENERIC_BUG
2873c2362e6SHarvey Harrison	def_bool y
2888d5fffb9SSam Ravnborg	depends on BUG
289b93a531eSJan Beulich	select GENERIC_BUG_RELATIVE_POINTERS if X86_64
290b93a531eSJan Beulich
291b93a531eSJan Beulichconfig GENERIC_BUG_RELATIVE_POINTERS
292b93a531eSJan Beulich	bool
2938d5fffb9SSam Ravnborg
2948d5fffb9SSam Ravnborgconfig ARCH_MAY_HAVE_PC_FDC
2953120e25eSJan Beulich	def_bool y
2963120e25eSJan Beulich	depends on ISA_DMA_API
2978d5fffb9SSam Ravnborg
2981032c0baSSam Ravnborgconfig GENERIC_CALIBRATE_DELAY
2991032c0baSSam Ravnborg	def_bool y
3001032c0baSSam Ravnborg
3019a0b8415Svenkatesh.pallipadi@intel.comconfig ARCH_HAS_CPU_RELAX
3029a0b8415Svenkatesh.pallipadi@intel.com	def_bool y
3038d5fffb9SSam Ravnborg
3041b27d05bSPekka Enbergconfig ARCH_HAS_CACHE_LINE_SIZE
3051b27d05bSPekka Enberg	def_bool y
3061b27d05bSPekka Enberg
307316d097cSDave Hansenconfig ARCH_HAS_FILTER_PGPROT
308316d097cSDave Hansen	def_bool y
309316d097cSDave Hansen
310dd5af90aSMike Travisconfig HAVE_SETUP_PER_CPU_AREA
31189c9c4c5SBrian Gerst	def_bool y
312b32ef636Stravis@sgi.com
31308fc4580STejun Heoconfig NEED_PER_CPU_EMBED_FIRST_CHUNK
31408fc4580STejun Heo	def_bool y
31508fc4580STejun Heo
31608fc4580STejun Heoconfig NEED_PER_CPU_PAGE_FIRST_CHUNK
31711124411STejun Heo	def_bool y
31811124411STejun Heo
319801e4062SJohannes Bergconfig ARCH_HIBERNATION_POSSIBLE
320801e4062SJohannes Berg	def_bool y
321801e4062SJohannes Berg
322f4cb5700SJohannes Bergconfig ARCH_SUSPEND_POSSIBLE
323f4cb5700SJohannes Berg	def_bool y
324f4cb5700SJohannes Berg
32553313b2cSSteve Capperconfig ARCH_WANT_GENERAL_HUGETLB
32653313b2cSSteve Capper	def_bool y
32753313b2cSSteve Capper
3288d5fffb9SSam Ravnborgconfig ZONE_DMA32
329e0fd24a3SJan Beulich	def_bool y if X86_64
3308d5fffb9SSam Ravnborg
3318d5fffb9SSam Ravnborgconfig AUDIT_ARCH
332e0fd24a3SJan Beulich	def_bool y if X86_64
3338d5fffb9SSam Ravnborg
3346a11f75bSAkinobu Mitaconfig ARCH_SUPPORTS_DEBUG_PAGEALLOC
3356a11f75bSAkinobu Mita	def_bool y
3366a11f75bSAkinobu Mita
337d6f2d75aSAndrey Ryabininconfig KASAN_SHADOW_OFFSET
338d6f2d75aSAndrey Ryabinin	hex
339d6f2d75aSAndrey Ryabinin	depends on KASAN
340d6f2d75aSAndrey Ryabinin	default 0xdffffc0000000000
341d6f2d75aSAndrey Ryabinin
34269575d38SShane Wangconfig HAVE_INTEL_TXT
34369575d38SShane Wang	def_bool y
3446ea30386SKees Cook	depends on INTEL_IOMMU && ACPI
34569575d38SShane Wang
3466b0c3d44SSam Ravnborgconfig X86_32_SMP
3476b0c3d44SSam Ravnborg	def_bool y
3486b0c3d44SSam Ravnborg	depends on X86_32 && SMP
3496b0c3d44SSam Ravnborg
3506b0c3d44SSam Ravnborgconfig X86_64_SMP
3516b0c3d44SSam Ravnborg	def_bool y
3526b0c3d44SSam Ravnborg	depends on X86_64 && SMP
3536b0c3d44SSam Ravnborg
354ccbeed3aSTejun Heoconfig X86_32_LAZY_GS
355ccbeed3aSTejun Heo	def_bool y
3568458f8c2SMasahiro Yamada	depends on X86_32 && !STACKPROTECTOR
357ccbeed3aSTejun Heo
3582b144498SSrikar Dronamrajuconfig ARCH_SUPPORTS_UPROBES
3592b144498SSrikar Dronamraju	def_bool y
3602b144498SSrikar Dronamraju
361d20642f0SRob Herringconfig FIX_EARLYCON_MEM
362d20642f0SRob Herring	def_bool y
363d20642f0SRob Herring
36494d49eb3SKirill A. Shutemovconfig DYNAMIC_PHYSICAL_MASK
36594d49eb3SKirill A. Shutemov	bool
36694d49eb3SKirill A. Shutemov
36798233368SKirill A. Shutemovconfig PGTABLE_LEVELS
36898233368SKirill A. Shutemov	int
36977ef56e4SKirill A. Shutemov	default 5 if X86_5LEVEL
37098233368SKirill A. Shutemov	default 4 if X86_64
37198233368SKirill A. Shutemov	default 3 if X86_PAE
37298233368SKirill A. Shutemov	default 2
37398233368SKirill A. Shutemov
3742a61f474SMasahiro Yamadaconfig CC_HAS_SANE_STACKPROTECTOR
3752a61f474SMasahiro Yamada	bool
3762a61f474SMasahiro Yamada	default $(success,$(srctree)/scripts/gcc-x86_64-has-stack-protector.sh $(CC)) if 64BIT
3772a61f474SMasahiro Yamada	default $(success,$(srctree)/scripts/gcc-x86_32-has-stack-protector.sh $(CC))
3782a61f474SMasahiro Yamada	help
3792a61f474SMasahiro Yamada	   We have to make sure stack protector is unconditionally disabled if
3802a61f474SMasahiro Yamada	   the compiler produces broken code.
3812a61f474SMasahiro Yamada
382506f1d07SSam Ravnborgmenu "Processor type and features"
383506f1d07SSam Ravnborg
3845ee71535SRandy Dunlapconfig ZONE_DMA
3855ee71535SRandy Dunlap	bool "DMA memory allocation support" if EXPERT
3865ee71535SRandy Dunlap	default y
3875ee71535SRandy Dunlap	help
3885ee71535SRandy Dunlap	  DMA memory allocation support allows devices with less than 32-bit
3895ee71535SRandy Dunlap	  addressing to allocate within the first 16MB of address space.
3905ee71535SRandy Dunlap	  Disable if no such devices will be used.
3915ee71535SRandy Dunlap
3925ee71535SRandy Dunlap	  If unsure, say Y.
3935ee71535SRandy Dunlap
394506f1d07SSam Ravnborgconfig SMP
395506f1d07SSam Ravnborg	bool "Symmetric multi-processing support"
396a7f7f624SMasahiro Yamada	help
397506f1d07SSam Ravnborg	  This enables support for systems with more than one CPU. If you have
3984a474157SRobert Graffham	  a system with only one CPU, say N. If you have a system with more
3994a474157SRobert Graffham	  than one CPU, say Y.
400506f1d07SSam Ravnborg
4014a474157SRobert Graffham	  If you say N here, the kernel will run on uni- and multiprocessor
402506f1d07SSam Ravnborg	  machines, but will use only one CPU of a multiprocessor machine. If
403506f1d07SSam Ravnborg	  you say Y here, the kernel will run on many, but not all,
4044a474157SRobert Graffham	  uniprocessor machines. On a uniprocessor machine, the kernel
405506f1d07SSam Ravnborg	  will run faster if you say N here.
406506f1d07SSam Ravnborg
407506f1d07SSam Ravnborg	  Note that if you say Y here and choose architecture "586" or
408506f1d07SSam Ravnborg	  "Pentium" under "Processor family", the kernel will not work on 486
409506f1d07SSam Ravnborg	  architectures. Similarly, multiprocessor kernels for the "PPro"
410506f1d07SSam Ravnborg	  architecture may not work on all Pentium based boards.
411506f1d07SSam Ravnborg
412506f1d07SSam Ravnborg	  People using multiprocessor machines who say Y here should also say
413506f1d07SSam Ravnborg	  Y to "Enhanced Real Time Clock Support", below. The "Advanced Power
414506f1d07SSam Ravnborg	  Management" code will be disabled if you say Y here.
415506f1d07SSam Ravnborg
416cb1aaebeSMauro Carvalho Chehab	  See also <file:Documentation/x86/i386/IO-APIC.rst>,
4174f4cfa6cSMauro Carvalho Chehab	  <file:Documentation/admin-guide/lockup-watchdogs.rst> and the SMP-HOWTO available at
418506f1d07SSam Ravnborg	  <http://www.tldp.org/docs.html#howto>.
419506f1d07SSam Ravnborg
420506f1d07SSam Ravnborg	  If you don't know what to do here, say N.
421506f1d07SSam Ravnborg
4229def39beSJosh Triplettconfig X86_FEATURE_NAMES
4239def39beSJosh Triplett	bool "Processor feature human-readable names" if EMBEDDED
4249def39beSJosh Triplett	default y
425a7f7f624SMasahiro Yamada	help
4269def39beSJosh Triplett	  This option compiles in a table of x86 feature bits and corresponding
4279def39beSJosh Triplett	  names.  This is required to support /proc/cpuinfo and a few kernel
4289def39beSJosh Triplett	  messages.  You can disable this to save space, at the expense of
4299def39beSJosh Triplett	  making those few kernel messages show numeric feature bits instead.
4309def39beSJosh Triplett
4319def39beSJosh Triplett	  If in doubt, say Y.
4329def39beSJosh Triplett
43306cd9a7dSYinghai Luconfig X86_X2APIC
43406cd9a7dSYinghai Lu	bool "Support x2apic"
43519e3d60dSJan Kiszka	depends on X86_LOCAL_APIC && X86_64 && (IRQ_REMAP || HYPERVISOR_GUEST)
436a7f7f624SMasahiro Yamada	help
43706cd9a7dSYinghai Lu	  This enables x2apic support on CPUs that have this feature.
43806cd9a7dSYinghai Lu
43906cd9a7dSYinghai Lu	  This allows 32-bit apic IDs (so it can support very large systems),
44006cd9a7dSYinghai Lu	  and accesses the local apic via MSRs not via mmio.
44106cd9a7dSYinghai Lu
44206cd9a7dSYinghai Lu	  If you don't know what to do here, say N.
44306cd9a7dSYinghai Lu
4446695c85bSYinghai Luconfig X86_MPPARSE
4456e87f9b7SBin Gao	bool "Enable MPS table" if ACPI || SFI
4467a527688SJan Beulich	default y
4475ab74722SIngo Molnar	depends on X86_LOCAL_APIC
448a7f7f624SMasahiro Yamada	help
4496695c85bSYinghai Lu	  For old smp systems that do not have proper acpi support. Newer systems
4506695c85bSYinghai Lu	  (esp with 64bit cpus) with acpi support, MADT and DSDT will override it
4516695c85bSYinghai Lu
452ddd70cf9SJun Nakajimaconfig GOLDFISH
453ddd70cf9SJun Nakajima	def_bool y
454ddd70cf9SJun Nakajima	depends on X86_GOLDFISH
455ddd70cf9SJun Nakajima
45676b04384SDavid Woodhouseconfig RETPOLINE
45776b04384SDavid Woodhouse	bool "Avoid speculative indirect branches in kernel"
45876b04384SDavid Woodhouse	default y
45976b04384SDavid Woodhouse	help
46076b04384SDavid Woodhouse	  Compile kernel with the retpoline compiler options to guard against
46176b04384SDavid Woodhouse	  kernel-to-user data leaks by avoiding speculative indirect
46276b04384SDavid Woodhouse	  branches. Requires a compiler with -mindirect-branch=thunk-extern
46376b04384SDavid Woodhouse	  support for full protection. The kernel may run slower.
46476b04384SDavid Woodhouse
465e6d42931SJohannes Weinerconfig X86_CPU_RESCTRL
466e6d42931SJohannes Weiner	bool "x86 CPU resource control support"
4676fe07ce3SBabu Moger	depends on X86 && (CPU_SUP_INTEL || CPU_SUP_AMD)
46859fe5a77SThomas Gleixner	select KERNFS
469e79f15a4SChen Yu	select PROC_CPU_RESCTRL		if PROC_FS
47078e99b4aSFenghua Yu	help
471e6d42931SJohannes Weiner	  Enable x86 CPU resource control support.
4726fe07ce3SBabu Moger
4736fe07ce3SBabu Moger	  Provide support for the allocation and monitoring of system resources
4746fe07ce3SBabu Moger	  usage by the CPU.
4756fe07ce3SBabu Moger
4766fe07ce3SBabu Moger	  Intel calls this Intel Resource Director Technology
4776fe07ce3SBabu Moger	  (Intel(R) RDT). More information about RDT can be found in the
4786fe07ce3SBabu Moger	  Intel x86 Architecture Software Developer Manual.
4796fe07ce3SBabu Moger
4806fe07ce3SBabu Moger	  AMD calls this AMD Platform Quality of Service (AMD QoS).
4816fe07ce3SBabu Moger	  More information about AMD QoS can be found in the AMD64 Technology
4826fe07ce3SBabu Moger	  Platform Quality of Service Extensions manual.
48378e99b4aSFenghua Yu
48478e99b4aSFenghua Yu	  Say N if unsure.
48578e99b4aSFenghua Yu
4868425091fSRavikiran G Thirumalaiif X86_32
487a0d0bb4dSRandy Dunlapconfig X86_BIGSMP
488a0d0bb4dSRandy Dunlap	bool "Support for big SMP systems with more than 8 CPUs"
489a0d0bb4dSRandy Dunlap	depends on SMP
490a7f7f624SMasahiro Yamada	help
491e133f6eaSRandy Dunlap	  This option is needed for the systems that have more than 8 CPUs.
492a0d0bb4dSRandy Dunlap
493c5c606d9SRavikiran G Thirumalaiconfig X86_EXTENDED_PLATFORM
494c5c606d9SRavikiran G Thirumalai	bool "Support for extended (non-PC) x86 platforms"
495c5c606d9SRavikiran G Thirumalai	default y
496a7f7f624SMasahiro Yamada	help
49706ac8346SIngo Molnar	  If you disable this option then the kernel will only support
49806ac8346SIngo Molnar	  standard PC platforms. (which covers the vast majority of
49906ac8346SIngo Molnar	  systems out there.)
50006ac8346SIngo Molnar
5018425091fSRavikiran G Thirumalai	  If you enable this option then you'll be able to select support
5028425091fSRavikiran G Thirumalai	  for the following (non-PC) 32 bit x86 platforms:
503cb7b8023SBen Hutchings		Goldfish (Android emulator)
5048425091fSRavikiran G Thirumalai		AMD Elan
5058425091fSRavikiran G Thirumalai		RDC R-321x SoC
5068425091fSRavikiran G Thirumalai		SGI 320/540 (Visual Workstation)
50783125a3aSAlessandro Rubini		STA2X11-based (e.g. Northville)
5083f4110a4SThomas Gleixner		Moorestown MID devices
50906ac8346SIngo Molnar
51006ac8346SIngo Molnar	  If you have one of these systems, or if you want to build a
51106ac8346SIngo Molnar	  generic distribution kernel, say Y here - otherwise say N.
5128425091fSRavikiran G Thirumalaiendif
51306ac8346SIngo Molnar
5148425091fSRavikiran G Thirumalaiif X86_64
5158425091fSRavikiran G Thirumalaiconfig X86_EXTENDED_PLATFORM
5168425091fSRavikiran G Thirumalai	bool "Support for extended (non-PC) x86 platforms"
5178425091fSRavikiran G Thirumalai	default y
518a7f7f624SMasahiro Yamada	help
5198425091fSRavikiran G Thirumalai	  If you disable this option then the kernel will only support
5208425091fSRavikiran G Thirumalai	  standard PC platforms. (which covers the vast majority of
5218425091fSRavikiran G Thirumalai	  systems out there.)
5228425091fSRavikiran G Thirumalai
5238425091fSRavikiran G Thirumalai	  If you enable this option then you'll be able to select support
5248425091fSRavikiran G Thirumalai	  for the following (non-PC) 64 bit x86 platforms:
52544b111b5SSteffen Persvold		Numascale NumaChip
5268425091fSRavikiran G Thirumalai		ScaleMP vSMP
5278425091fSRavikiran G Thirumalai		SGI Ultraviolet
5288425091fSRavikiran G Thirumalai
5298425091fSRavikiran G Thirumalai	  If you have one of these systems, or if you want to build a
5308425091fSRavikiran G Thirumalai	  generic distribution kernel, say Y here - otherwise say N.
5318425091fSRavikiran G Thirumalaiendif
532c5c606d9SRavikiran G Thirumalai# This is an alphabetically sorted list of 64 bit extended platforms
533c5c606d9SRavikiran G Thirumalai# Please maintain the alphabetic order if and when there are additions
53444b111b5SSteffen Persvoldconfig X86_NUMACHIP
53544b111b5SSteffen Persvold	bool "Numascale NumaChip"
53644b111b5SSteffen Persvold	depends on X86_64
53744b111b5SSteffen Persvold	depends on X86_EXTENDED_PLATFORM
53844b111b5SSteffen Persvold	depends on NUMA
53944b111b5SSteffen Persvold	depends on SMP
54044b111b5SSteffen Persvold	depends on X86_X2APIC
541f9726bfdSDaniel J Blueman	depends on PCI_MMCONFIG
542a7f7f624SMasahiro Yamada	help
54344b111b5SSteffen Persvold	  Adds support for Numascale NumaChip large-SMP systems. Needed to
54444b111b5SSteffen Persvold	  enable more than ~168 cores.
54544b111b5SSteffen Persvold	  If you don't have one of these, you should say N here.
54603b48632SNick Piggin
5476a48565eSIngo Molnarconfig X86_VSMP
548c5c606d9SRavikiran G Thirumalai	bool "ScaleMP vSMP"
5496276a074SBorislav Petkov	select HYPERVISOR_GUEST
5506a48565eSIngo Molnar	select PARAVIRT
5516a48565eSIngo Molnar	depends on X86_64 && PCI
552c5c606d9SRavikiran G Thirumalai	depends on X86_EXTENDED_PLATFORM
553ead91d4bSShai Fultheim	depends on SMP
554a7f7f624SMasahiro Yamada	help
5556a48565eSIngo Molnar	  Support for ScaleMP vSMP systems.  Say 'Y' here if this kernel is
5566a48565eSIngo Molnar	  supposed to run on these EM64T-based machines.  Only choose this option
5576a48565eSIngo Molnar	  if you have one of these machines.
5586a48565eSIngo Molnar
559c5c606d9SRavikiran G Thirumalaiconfig X86_UV
560c5c606d9SRavikiran G Thirumalai	bool "SGI Ultraviolet"
561c5c606d9SRavikiran G Thirumalai	depends on X86_64
562c5c606d9SRavikiran G Thirumalai	depends on X86_EXTENDED_PLATFORM
56354c28d29SJack Steiner	depends on NUMA
5641ecb4ae5SAndrew Morton	depends on EFI
5659d6c26e7SSuresh Siddha	depends on X86_X2APIC
5661222e564SIngo Molnar	depends on PCI
567a7f7f624SMasahiro Yamada	help
568c5c606d9SRavikiran G Thirumalai	  This option is needed in order to support SGI Ultraviolet systems.
569c5c606d9SRavikiran G Thirumalai	  If you don't have one of these, you should say N here.
570c5c606d9SRavikiran G Thirumalai
571c5c606d9SRavikiran G Thirumalai# Following is an alphabetically sorted list of 32 bit extended platforms
572c5c606d9SRavikiran G Thirumalai# Please maintain the alphabetic order if and when there are additions
573506f1d07SSam Ravnborg
574ddd70cf9SJun Nakajimaconfig X86_GOLDFISH
575ddd70cf9SJun Nakajima	bool "Goldfish (Virtual Platform)"
576cb7b8023SBen Hutchings	depends on X86_EXTENDED_PLATFORM
577a7f7f624SMasahiro Yamada	help
578ddd70cf9SJun Nakajima	 Enable support for the Goldfish virtual platform used primarily
579ddd70cf9SJun Nakajima	 for Android development. Unless you are building for the Android
580ddd70cf9SJun Nakajima	 Goldfish emulator say N here.
581ddd70cf9SJun Nakajima
582c751e17bSThomas Gleixnerconfig X86_INTEL_CE
583c751e17bSThomas Gleixner	bool "CE4100 TV platform"
584c751e17bSThomas Gleixner	depends on PCI
585c751e17bSThomas Gleixner	depends on PCI_GODIRECT
5866084a6e2SJiang Liu	depends on X86_IO_APIC
587c751e17bSThomas Gleixner	depends on X86_32
588c751e17bSThomas Gleixner	depends on X86_EXTENDED_PLATFORM
58937bc9f50SDirk Brandewie	select X86_REBOOTFIXUPS
590da6b737bSSebastian Andrzej Siewior	select OF
591da6b737bSSebastian Andrzej Siewior	select OF_EARLY_FLATTREE
592a7f7f624SMasahiro Yamada	help
593c751e17bSThomas Gleixner	  Select for the Intel CE media processor (CE4100) SOC.
594c751e17bSThomas Gleixner	  This option compiles in support for the CE4100 SOC for settop
595c751e17bSThomas Gleixner	  boxes and media devices.
596c751e17bSThomas Gleixner
5974cb9b00fSDavid Cohenconfig X86_INTEL_MID
59843605ef1SAlan Cox	bool "Intel MID platform support"
59943605ef1SAlan Cox	depends on X86_EXTENDED_PLATFORM
600edc6bc78SDavid Cohen	depends on X86_PLATFORM_DEVICES
6011ea7c673SAlan Cox	depends on PCI
6023fda5bb4SAndy Shevchenko	depends on X86_64 || (PCI_GOANY && X86_32)
6031ea7c673SAlan Cox	depends on X86_IO_APIC
6047c9c3a1eSAlan Cox	select SFI
6054cb9b00fSDavid Cohen	select I2C
6067c9c3a1eSAlan Cox	select DW_APB_TIMER
6071ea7c673SAlan Cox	select APB_TIMER
60854b34aa0SMika Westerberg	select INTEL_SCU_PCI
60915a713dfSMika Westerberg	select MFD_INTEL_MSIC
610a7f7f624SMasahiro Yamada	help
6114cb9b00fSDavid Cohen	  Select to build a kernel capable of supporting Intel MID (Mobile
6124cb9b00fSDavid Cohen	  Internet Device) platform systems which do not have the PCI legacy
6134cb9b00fSDavid Cohen	  interfaces. If you are building for a PC class system say N here.
6141ea7c673SAlan Cox
6154cb9b00fSDavid Cohen	  Intel MID platforms are based on an Intel processor and chipset which
6164cb9b00fSDavid Cohen	  consume less power than most of the x86 derivatives.
61743605ef1SAlan Cox
6188bbc2a13SBryan O'Donoghueconfig X86_INTEL_QUARK
6198bbc2a13SBryan O'Donoghue	bool "Intel Quark platform support"
6208bbc2a13SBryan O'Donoghue	depends on X86_32
6218bbc2a13SBryan O'Donoghue	depends on X86_EXTENDED_PLATFORM
6228bbc2a13SBryan O'Donoghue	depends on X86_PLATFORM_DEVICES
6238bbc2a13SBryan O'Donoghue	depends on X86_TSC
6248bbc2a13SBryan O'Donoghue	depends on PCI
6258bbc2a13SBryan O'Donoghue	depends on PCI_GOANY
6268bbc2a13SBryan O'Donoghue	depends on X86_IO_APIC
6278bbc2a13SBryan O'Donoghue	select IOSF_MBI
6288bbc2a13SBryan O'Donoghue	select INTEL_IMR
6299ab6eb51SAndy Shevchenko	select COMMON_CLK
630a7f7f624SMasahiro Yamada	help
6318bbc2a13SBryan O'Donoghue	  Select to include support for Quark X1000 SoC.
6328bbc2a13SBryan O'Donoghue	  Say Y here if you have a Quark based system such as the Arduino
6338bbc2a13SBryan O'Donoghue	  compatible Intel Galileo.
6348bbc2a13SBryan O'Donoghue
6353d48aab1SMika Westerbergconfig X86_INTEL_LPSS
6363d48aab1SMika Westerberg	bool "Intel Low Power Subsystem Support"
6375962dd22SSinan Kaya	depends on X86 && ACPI && PCI
6383d48aab1SMika Westerberg	select COMMON_CLK
6390f531431SMathias Nyman	select PINCTRL
640eebb3e8dSAndy Shevchenko	select IOSF_MBI
641a7f7f624SMasahiro Yamada	help
6423d48aab1SMika Westerberg	  Select to build support for Intel Low Power Subsystem such as
6433d48aab1SMika Westerberg	  found on Intel Lynxpoint PCH. Selecting this option enables
6440f531431SMathias Nyman	  things like clock tree (common clock framework) and pincontrol
6450f531431SMathias Nyman	  which are needed by the LPSS peripheral drivers.
6463d48aab1SMika Westerberg
64792082a88SKen Xueconfig X86_AMD_PLATFORM_DEVICE
64892082a88SKen Xue	bool "AMD ACPI2Platform devices support"
64992082a88SKen Xue	depends on ACPI
65092082a88SKen Xue	select COMMON_CLK
65192082a88SKen Xue	select PINCTRL
652a7f7f624SMasahiro Yamada	help
65392082a88SKen Xue	  Select to interpret AMD specific ACPI device to platform device
65492082a88SKen Xue	  such as I2C, UART, GPIO found on AMD Carrizo and later chipsets.
65592082a88SKen Xue	  I2C and UART depend on COMMON_CLK to set clock. GPIO driver is
65692082a88SKen Xue	  implemented under PINCTRL subsystem.
65792082a88SKen Xue
658ced3ce76SDavid E. Boxconfig IOSF_MBI
659ced3ce76SDavid E. Box	tristate "Intel SoC IOSF Sideband support for SoC platforms"
660ced3ce76SDavid E. Box	depends on PCI
661a7f7f624SMasahiro Yamada	help
662ced3ce76SDavid E. Box	  This option enables sideband register access support for Intel SoC
663ced3ce76SDavid E. Box	  platforms. On these platforms the IOSF sideband is used in lieu of
664ced3ce76SDavid E. Box	  MSR's for some register accesses, mostly but not limited to thermal
665ced3ce76SDavid E. Box	  and power. Drivers may query the availability of this device to
666ced3ce76SDavid E. Box	  determine if they need the sideband in order to work on these
667ced3ce76SDavid E. Box	  platforms. The sideband is available on the following SoC products.
668ced3ce76SDavid E. Box	  This list is not meant to be exclusive.
669ced3ce76SDavid E. Box	   - BayTrail
670ced3ce76SDavid E. Box	   - Braswell
671ced3ce76SDavid E. Box	   - Quark
672ced3ce76SDavid E. Box
673ced3ce76SDavid E. Box	  You should say Y if you are running a kernel on one of these SoC's.
674ced3ce76SDavid E. Box
675ed2226bdSDavid E. Boxconfig IOSF_MBI_DEBUG
676ed2226bdSDavid E. Box	bool "Enable IOSF sideband access through debugfs"
677ed2226bdSDavid E. Box	depends on IOSF_MBI && DEBUG_FS
678a7f7f624SMasahiro Yamada	help
679ed2226bdSDavid E. Box	  Select this option to expose the IOSF sideband access registers (MCR,
680ed2226bdSDavid E. Box	  MDR, MCRX) through debugfs to write and read register information from
681ed2226bdSDavid E. Box	  different units on the SoC. This is most useful for obtaining device
682ed2226bdSDavid E. Box	  state information for debug and analysis. As this is a general access
683ed2226bdSDavid E. Box	  mechanism, users of this option would have specific knowledge of the
684ed2226bdSDavid E. Box	  device they want to access.
685ed2226bdSDavid E. Box
686ed2226bdSDavid E. Box	  If you don't require the option or are in doubt, say N.
687ed2226bdSDavid E. Box
688c5c606d9SRavikiran G Thirumalaiconfig X86_RDC321X
689c5c606d9SRavikiran G Thirumalai	bool "RDC R-321x SoC"
690506f1d07SSam Ravnborg	depends on X86_32
691c5c606d9SRavikiran G Thirumalai	depends on X86_EXTENDED_PLATFORM
692c5c606d9SRavikiran G Thirumalai	select M486
693c5c606d9SRavikiran G Thirumalai	select X86_REBOOTFIXUPS
694a7f7f624SMasahiro Yamada	help
695c5c606d9SRavikiran G Thirumalai	  This option is needed for RDC R-321x system-on-chip, also known
696c5c606d9SRavikiran G Thirumalai	  as R-8610-(G).
697c5c606d9SRavikiran G Thirumalai	  If you don't have one of these chips, you should say N here.
698c5c606d9SRavikiran G Thirumalai
699e0c7ae37SIngo Molnarconfig X86_32_NON_STANDARD
7009c398017SIngo Molnar	bool "Support non-standard 32-bit SMP architectures"
7019c398017SIngo Molnar	depends on X86_32 && SMP
702c5c606d9SRavikiran G Thirumalai	depends on X86_EXTENDED_PLATFORM
703a7f7f624SMasahiro Yamada	help
704b5660ba7SH. Peter Anvin	  This option compiles in the bigsmp and STA2X11 default
705b5660ba7SH. Peter Anvin	  subarchitectures.  It is intended for a generic binary
706b5660ba7SH. Peter Anvin	  kernel. If you select them all, kernel will probe it one by
707b5660ba7SH. Peter Anvin	  one and will fallback to default.
708d49c4288SYinghai Lu
709c5c606d9SRavikiran G Thirumalai# Alphabetically sorted list of Non standard 32 bit platforms
710d49c4288SYinghai Lu
711d949f36fSLinus Torvaldsconfig X86_SUPPORTS_MEMORY_FAILURE
7126fc108a0SJan Beulich	def_bool y
713d949f36fSLinus Torvalds	# MCE code calls memory_failure():
714d949f36fSLinus Torvalds	depends on X86_MCE
715d949f36fSLinus Torvalds	# On 32-bit this adds too big of NODES_SHIFT and we run out of page flags:
716d949f36fSLinus Torvalds	# On 32-bit SPARSEMEM adds too big of SECTIONS_WIDTH:
717d949f36fSLinus Torvalds	depends on X86_64 || !SPARSEMEM
718d949f36fSLinus Torvalds	select ARCH_SUPPORTS_MEMORY_FAILURE
719d949f36fSLinus Torvalds
72083125a3aSAlessandro Rubiniconfig STA2X11
72183125a3aSAlessandro Rubini	bool "STA2X11 Companion Chip Support"
72283125a3aSAlessandro Rubini	depends on X86_32_NON_STANDARD && PCI
72383125a3aSAlessandro Rubini	select SWIOTLB
72483125a3aSAlessandro Rubini	select MFD_STA2X11
7250145071bSLinus Walleij	select GPIOLIB
726a7f7f624SMasahiro Yamada	help
72783125a3aSAlessandro Rubini	  This adds support for boards based on the STA2X11 IO-Hub,
72883125a3aSAlessandro Rubini	  a.k.a. "ConneXt". The chip is used in place of the standard
72983125a3aSAlessandro Rubini	  PC chipset, so all "standard" peripherals are missing. If this
73083125a3aSAlessandro Rubini	  option is selected the kernel will still be able to boot on
73183125a3aSAlessandro Rubini	  standard PC machines.
73283125a3aSAlessandro Rubini
73382148d1dSShérabconfig X86_32_IRIS
73482148d1dSShérab	tristate "Eurobraille/Iris poweroff module"
73582148d1dSShérab	depends on X86_32
736a7f7f624SMasahiro Yamada	help
73782148d1dSShérab	  The Iris machines from EuroBraille do not have APM or ACPI support
73882148d1dSShérab	  to shut themselves down properly.  A special I/O sequence is
73982148d1dSShérab	  needed to do so, which is what this module does at
74082148d1dSShérab	  kernel shutdown.
74182148d1dSShérab
74282148d1dSShérab	  This is only for Iris machines from EuroBraille.
74382148d1dSShérab
74482148d1dSShérab	  If unused, say N.
74582148d1dSShérab
746ae1e9130SIngo Molnarconfig SCHED_OMIT_FRAME_POINTER
7473c2362e6SHarvey Harrison	def_bool y
7483c2362e6SHarvey Harrison	prompt "Single-depth WCHAN output"
749a87d0914SKen Chen	depends on X86
750a7f7f624SMasahiro Yamada	help
751506f1d07SSam Ravnborg	  Calculate simpler /proc/<PID>/wchan values. If this option
752506f1d07SSam Ravnborg	  is disabled then wchan values will recurse back to the
753506f1d07SSam Ravnborg	  caller function. This provides more accurate wchan values,
754506f1d07SSam Ravnborg	  at the expense of slightly more scheduling overhead.
755506f1d07SSam Ravnborg
756506f1d07SSam Ravnborg	  If in doubt, say "Y".
757506f1d07SSam Ravnborg
7586276a074SBorislav Petkovmenuconfig HYPERVISOR_GUEST
7596276a074SBorislav Petkov	bool "Linux guest support"
760a7f7f624SMasahiro Yamada	help
7616276a074SBorislav Petkov	  Say Y here to enable options for running Linux under various hyper-
7626276a074SBorislav Petkov	  visors. This option enables basic hypervisor detection and platform
7636276a074SBorislav Petkov	  setup.
764506f1d07SSam Ravnborg
7656276a074SBorislav Petkov	  If you say N, all options in this submenu will be skipped and
7666276a074SBorislav Petkov	  disabled, and Linux guest support won't be built in.
767506f1d07SSam Ravnborg
7686276a074SBorislav Petkovif HYPERVISOR_GUEST
769506f1d07SSam Ravnborg
770e61bd94aSEduardo Pereira Habkostconfig PARAVIRT
771e61bd94aSEduardo Pereira Habkost	bool "Enable paravirtualization code"
772a7f7f624SMasahiro Yamada	help
773e61bd94aSEduardo Pereira Habkost	  This changes the kernel so it can modify itself when it is run
774e61bd94aSEduardo Pereira Habkost	  under a hypervisor, potentially improving performance significantly
775e61bd94aSEduardo Pereira Habkost	  over full virtualization.  However, when run without a hypervisor
776e61bd94aSEduardo Pereira Habkost	  the kernel is theoretically slower and slightly larger.
777e61bd94aSEduardo Pereira Habkost
778c00a280aSJuergen Grossconfig PARAVIRT_XXL
779c00a280aSJuergen Gross	bool
780c00a280aSJuergen Gross
7816276a074SBorislav Petkovconfig PARAVIRT_DEBUG
7826276a074SBorislav Petkov	bool "paravirt-ops debugging"
7836276a074SBorislav Petkov	depends on PARAVIRT && DEBUG_KERNEL
784a7f7f624SMasahiro Yamada	help
7856276a074SBorislav Petkov	  Enable to debug paravirt_ops internals.  Specifically, BUG if
7866276a074SBorislav Petkov	  a paravirt_op is missing when it is called.
7876276a074SBorislav Petkov
788b4ecc126SJeremy Fitzhardingeconfig PARAVIRT_SPINLOCKS
789b4ecc126SJeremy Fitzhardinge	bool "Paravirtualization layer for spinlocks"
7906ea30386SKees Cook	depends on PARAVIRT && SMP
791a7f7f624SMasahiro Yamada	help
792b4ecc126SJeremy Fitzhardinge	  Paravirtualized spinlocks allow a pvops backend to replace the
793b4ecc126SJeremy Fitzhardinge	  spinlock implementation with something virtualization-friendly
794b4ecc126SJeremy Fitzhardinge	  (for example, block the virtual CPU rather than spinning).
795b4ecc126SJeremy Fitzhardinge
7964c4e4f61SRaghavendra K T	  It has a minimal impact on native kernels and gives a nice performance
7974c4e4f61SRaghavendra K T	  benefit on paravirtualized KVM / Xen kernels.
798b4ecc126SJeremy Fitzhardinge
7994c4e4f61SRaghavendra K T	  If you are unsure how to answer this question, answer Y.
800b4ecc126SJeremy Fitzhardinge
801ecca2502SZhao Yakuiconfig X86_HV_CALLBACK_VECTOR
802ecca2502SZhao Yakui	def_bool n
803ecca2502SZhao Yakui
8046276a074SBorislav Petkovsource "arch/x86/xen/Kconfig"
8056276a074SBorislav Petkov
8066276a074SBorislav Petkovconfig KVM_GUEST
8076276a074SBorislav Petkov	bool "KVM Guest support (including kvmclock)"
8086276a074SBorislav Petkov	depends on PARAVIRT
8096276a074SBorislav Petkov	select PARAVIRT_CLOCK
810a1c4423bSMarcelo Tosatti	select ARCH_CPUIDLE_HALTPOLL
811b1d40575SVitaly Kuznetsov	select X86_HV_CALLBACK_VECTOR
8126276a074SBorislav Petkov	default y
813a7f7f624SMasahiro Yamada	help
8146276a074SBorislav Petkov	  This option enables various optimizations for running under the KVM
8156276a074SBorislav Petkov	  hypervisor. It includes a paravirtualized clock, so that instead
8166276a074SBorislav Petkov	  of relying on a PIT (or probably other) emulation by the
8176276a074SBorislav Petkov	  underlying device model, the host provides the guest with
8186276a074SBorislav Petkov	  timing infrastructure such as time of day, and system time
8196276a074SBorislav Petkov
820a1c4423bSMarcelo Tosatticonfig ARCH_CPUIDLE_HALTPOLL
821a1c4423bSMarcelo Tosatti	def_bool n
822a1c4423bSMarcelo Tosatti	prompt "Disable host haltpoll when loading haltpoll driver"
823a1c4423bSMarcelo Tosatti	help
824a1c4423bSMarcelo Tosatti	  If virtualized under KVM, disable host haltpoll.
825a1c4423bSMarcelo Tosatti
8267733607fSMaran Wilsonconfig PVH
8277733607fSMaran Wilson	bool "Support for running PVH guests"
828a7f7f624SMasahiro Yamada	help
8297733607fSMaran Wilson	  This option enables the PVH entry point for guest virtual machines
8307733607fSMaran Wilson	  as specified in the x86/HVM direct boot ABI.
8317733607fSMaran Wilson
8326276a074SBorislav Petkovconfig PARAVIRT_TIME_ACCOUNTING
8336276a074SBorislav Petkov	bool "Paravirtual steal time accounting"
8346276a074SBorislav Petkov	depends on PARAVIRT
835a7f7f624SMasahiro Yamada	help
8366276a074SBorislav Petkov	  Select this option to enable fine granularity task steal time
8376276a074SBorislav Petkov	  accounting. Time spent executing other tasks in parallel with
8386276a074SBorislav Petkov	  the current vCPU is discounted from the vCPU power. To account for
8396276a074SBorislav Petkov	  that, there can be a small performance impact.
8406276a074SBorislav Petkov
8416276a074SBorislav Petkov	  If in doubt, say N here.
8426276a074SBorislav Petkov
8437af192c9SGerd Hoffmannconfig PARAVIRT_CLOCK
8447af192c9SGerd Hoffmann	bool
8457af192c9SGerd Hoffmann
8464a362601SJan Kiszkaconfig JAILHOUSE_GUEST
8474a362601SJan Kiszka	bool "Jailhouse non-root cell support"
848abde587bSArnd Bergmann	depends on X86_64 && PCI
84987e65d05SJan Kiszka	select X86_PM_TIMER
850a7f7f624SMasahiro Yamada	help
8514a362601SJan Kiszka	  This option allows to run Linux as guest in a Jailhouse non-root
8524a362601SJan Kiszka	  cell. You can leave this option disabled if you only want to start
8534a362601SJan Kiszka	  Jailhouse and run Linux afterwards in the root cell.
8544a362601SJan Kiszka
855ec7972c9SZhao Yakuiconfig ACRN_GUEST
856ec7972c9SZhao Yakui	bool "ACRN Guest support"
857ec7972c9SZhao Yakui	depends on X86_64
858498ad393SZhao Yakui	select X86_HV_CALLBACK_VECTOR
859ec7972c9SZhao Yakui	help
860ec7972c9SZhao Yakui	  This option allows to run Linux as guest in the ACRN hypervisor. ACRN is
861ec7972c9SZhao Yakui	  a flexible, lightweight reference open-source hypervisor, built with
862ec7972c9SZhao Yakui	  real-time and safety-criticality in mind. It is built for embedded
863ec7972c9SZhao Yakui	  IOT with small footprint and real-time features. More details can be
864ec7972c9SZhao Yakui	  found in https://projectacrn.org/.
865ec7972c9SZhao Yakui
8666276a074SBorislav Petkovendif #HYPERVISOR_GUEST
86797349135SJeremy Fitzhardinge
868506f1d07SSam Ravnborgsource "arch/x86/Kconfig.cpu"
869506f1d07SSam Ravnborg
870506f1d07SSam Ravnborgconfig HPET_TIMER
8713c2362e6SHarvey Harrison	def_bool X86_64
872506f1d07SSam Ravnborg	prompt "HPET Timer Support" if X86_32
873a7f7f624SMasahiro Yamada	help
874506f1d07SSam Ravnborg	  Use the IA-PC HPET (High Precision Event Timer) to manage
875506f1d07SSam Ravnborg	  time in preference to the PIT and RTC, if a HPET is
876506f1d07SSam Ravnborg	  present.
877506f1d07SSam Ravnborg	  HPET is the next generation timer replacing legacy 8254s.
878506f1d07SSam Ravnborg	  The HPET provides a stable time base on SMP
879506f1d07SSam Ravnborg	  systems, unlike the TSC, but it is more expensive to access,
8804e7f9df2SMichael S. Tsirkin	  as it is off-chip.  The interface used is documented
8814e7f9df2SMichael S. Tsirkin	  in the HPET spec, revision 1.
882506f1d07SSam Ravnborg
883506f1d07SSam Ravnborg	  You can safely choose Y here.  However, HPET will only be
884506f1d07SSam Ravnborg	  activated if the platform and the BIOS support this feature.
885506f1d07SSam Ravnborg	  Otherwise the 8254 will be used for timing services.
886506f1d07SSam Ravnborg
887506f1d07SSam Ravnborg	  Choose N to continue using the legacy 8254 timer.
888506f1d07SSam Ravnborg
889506f1d07SSam Ravnborgconfig HPET_EMULATE_RTC
8903c2362e6SHarvey Harrison	def_bool y
8919d8af78bSBernhard Walle	depends on HPET_TIMER && (RTC=y || RTC=m || RTC_DRV_CMOS=m || RTC_DRV_CMOS=y)
892506f1d07SSam Ravnborg
893bb24c471SJacob Panconfig APB_TIMER
894933b9463SAlan Cox	def_bool y if X86_INTEL_MID
895933b9463SAlan Cox	prompt "Intel MID APB Timer Support" if X86_INTEL_MID
89606c3df49SJamie Iles	select DW_APB_TIMER
897a0c3832aSAlan Cox	depends on X86_INTEL_MID && SFI
898bb24c471SJacob Pan	help
899bb24c471SJacob Pan	 APB timer is the replacement for 8254, HPET on X86 MID platforms.
900bb24c471SJacob Pan	 The APBT provides a stable time base on SMP
901bb24c471SJacob Pan	 systems, unlike the TSC, but it is more expensive to access,
902bb24c471SJacob Pan	 as it is off-chip. APB timers are always running regardless of CPU
903bb24c471SJacob Pan	 C states, they are used as per CPU clockevent device when possible.
904bb24c471SJacob Pan
9056a108a14SDavid Rientjes# Mark as expert because too many people got it wrong.
906506f1d07SSam Ravnborg# The code disables itself when not needed.
9077ae9392cSThomas Petazzoniconfig DMI
9087ae9392cSThomas Petazzoni	default y
909cf074402SArd Biesheuvel	select DMI_SCAN_MACHINE_NON_EFI_FALLBACK
9106a108a14SDavid Rientjes	bool "Enable DMI scanning" if EXPERT
911a7f7f624SMasahiro Yamada	help
9127ae9392cSThomas Petazzoni	  Enabled scanning of DMI to identify machine quirks. Say Y
9137ae9392cSThomas Petazzoni	  here unless you have verified that your setup is not
9147ae9392cSThomas Petazzoni	  affected by entries in the DMI blacklist. Required by PNP
9157ae9392cSThomas Petazzoni	  BIOS code.
9167ae9392cSThomas Petazzoni
917506f1d07SSam Ravnborgconfig GART_IOMMU
91838901f1cSAndi Kleen	bool "Old AMD GART IOMMU support"
9192f9237d4SChristoph Hellwig	select DMA_OPS
920a4ce5a48SChristoph Hellwig	select IOMMU_HELPER
921506f1d07SSam Ravnborg	select SWIOTLB
92223ac4ae8SAndreas Herrmann	depends on X86_64 && PCI && AMD_NB
923a7f7f624SMasahiro Yamada	help
924ced3c42cSIngo Molnar	  Provides a driver for older AMD Athlon64/Opteron/Turion/Sempron
925ced3c42cSIngo Molnar	  GART based hardware IOMMUs.
926ced3c42cSIngo Molnar
927ced3c42cSIngo Molnar	  The GART supports full DMA access for devices with 32-bit access
928ced3c42cSIngo Molnar	  limitations, on systems with more than 3 GB. This is usually needed
929ced3c42cSIngo Molnar	  for USB, sound, many IDE/SATA chipsets and some other devices.
930ced3c42cSIngo Molnar
931ced3c42cSIngo Molnar	  Newer systems typically have a modern AMD IOMMU, supported via
932ced3c42cSIngo Molnar	  the CONFIG_AMD_IOMMU=y config option.
933ced3c42cSIngo Molnar
934ced3c42cSIngo Molnar	  In normal configurations this driver is only active when needed:
935ced3c42cSIngo Molnar	  there's more than 3 GB of memory and the system contains a
936ced3c42cSIngo Molnar	  32-bit limited device.
937ced3c42cSIngo Molnar
938ced3c42cSIngo Molnar	  If unsure, say Y.
939506f1d07SSam Ravnborg
9401184dc2fSMike Travisconfig MAXSMP
941ddb0c5a6SSamuel Thibault	bool "Enable Maximum number of SMP Processors and NUMA Nodes"
9426ea30386SKees Cook	depends on X86_64 && SMP && DEBUG_KERNEL
94336f5101aSMike Travis	select CPUMASK_OFFSTACK
944a7f7f624SMasahiro Yamada	help
945ddb0c5a6SSamuel Thibault	  Enable maximum number of CPUS and NUMA Nodes for this architecture.
9461184dc2fSMike Travis	  If unsure, say N.
947506f1d07SSam Ravnborg
948aec6487eSIngo Molnar#
949aec6487eSIngo Molnar# The maximum number of CPUs supported:
950aec6487eSIngo Molnar#
951aec6487eSIngo Molnar# The main config value is NR_CPUS, which defaults to NR_CPUS_DEFAULT,
952aec6487eSIngo Molnar# and which can be configured interactively in the
953aec6487eSIngo Molnar# [NR_CPUS_RANGE_BEGIN ... NR_CPUS_RANGE_END] range.
954aec6487eSIngo Molnar#
955aec6487eSIngo Molnar# The ranges are different on 32-bit and 64-bit kernels, depending on
956aec6487eSIngo Molnar# hardware capabilities and scalability features of the kernel.
957aec6487eSIngo Molnar#
958aec6487eSIngo Molnar# ( If MAXSMP is enabled we just use the highest possible value and disable
959aec6487eSIngo Molnar#   interactive configuration. )
960aec6487eSIngo Molnar#
961a0d0bb4dSRandy Dunlap
962aec6487eSIngo Molnarconfig NR_CPUS_RANGE_BEGIN
963a0d0bb4dSRandy Dunlap	int
964aec6487eSIngo Molnar	default NR_CPUS_RANGE_END if MAXSMP
965a0d0bb4dSRandy Dunlap	default    1 if !SMP
966a0d0bb4dSRandy Dunlap	default    2
967a0d0bb4dSRandy Dunlap
968aec6487eSIngo Molnarconfig NR_CPUS_RANGE_END
969a0d0bb4dSRandy Dunlap	int
970a0d0bb4dSRandy Dunlap	depends on X86_32
971aec6487eSIngo Molnar	default   64 if  SMP &&  X86_BIGSMP
972aec6487eSIngo Molnar	default    8 if  SMP && !X86_BIGSMP
973a0d0bb4dSRandy Dunlap	default    1 if !SMP
974a0d0bb4dSRandy Dunlap
975aec6487eSIngo Molnarconfig NR_CPUS_RANGE_END
976a0d0bb4dSRandy Dunlap	int
977a0d0bb4dSRandy Dunlap	depends on X86_64
9781edae1aeSScott Wood	default 8192 if  SMP && CPUMASK_OFFSTACK
9791edae1aeSScott Wood	default  512 if  SMP && !CPUMASK_OFFSTACK
980a0d0bb4dSRandy Dunlap	default    1 if !SMP
981aec6487eSIngo Molnar
982aec6487eSIngo Molnarconfig NR_CPUS_DEFAULT
983aec6487eSIngo Molnar	int
984aec6487eSIngo Molnar	depends on X86_32
985aec6487eSIngo Molnar	default   32 if  X86_BIGSMP
986aec6487eSIngo Molnar	default    8 if  SMP
987aec6487eSIngo Molnar	default    1 if !SMP
988aec6487eSIngo Molnar
989aec6487eSIngo Molnarconfig NR_CPUS_DEFAULT
990aec6487eSIngo Molnar	int
991aec6487eSIngo Molnar	depends on X86_64
992a0d0bb4dSRandy Dunlap	default 8192 if  MAXSMP
993a0d0bb4dSRandy Dunlap	default   64 if  SMP
994aec6487eSIngo Molnar	default    1 if !SMP
995a0d0bb4dSRandy Dunlap
996506f1d07SSam Ravnborgconfig NR_CPUS
99736f5101aSMike Travis	int "Maximum number of CPUs" if SMP && !MAXSMP
998aec6487eSIngo Molnar	range NR_CPUS_RANGE_BEGIN NR_CPUS_RANGE_END
999aec6487eSIngo Molnar	default NR_CPUS_DEFAULT
1000a7f7f624SMasahiro Yamada	help
1001506f1d07SSam Ravnborg	  This allows you to specify the maximum number of CPUs which this
1002bb61ccc7SJosh Boyer	  kernel will support.  If CPUMASK_OFFSTACK is enabled, the maximum
1003cad14bb9SKirill A. Shutemov	  supported value is 8192, otherwise the maximum value is 512.  The
1004506f1d07SSam Ravnborg	  minimum value which makes sense is 2.
1005506f1d07SSam Ravnborg
1006aec6487eSIngo Molnar	  This is purely to save memory: each supported CPU adds about 8KB
1007aec6487eSIngo Molnar	  to the kernel image.
1008506f1d07SSam Ravnborg
1009506f1d07SSam Ravnborgconfig SCHED_SMT
1010dbe73364SThomas Gleixner	def_bool y if SMP
1011506f1d07SSam Ravnborg
1012506f1d07SSam Ravnborgconfig SCHED_MC
10133c2362e6SHarvey Harrison	def_bool y
10143c2362e6SHarvey Harrison	prompt "Multi-core scheduler support"
1015c8e56d20SBorislav Petkov	depends on SMP
1016a7f7f624SMasahiro Yamada	help
1017506f1d07SSam Ravnborg	  Multi-core scheduler support improves the CPU scheduler's decision
1018506f1d07SSam Ravnborg	  making when dealing with multi-core CPU chips at a cost of slightly
1019506f1d07SSam Ravnborg	  increased overhead in some places. If unsure say N here.
1020506f1d07SSam Ravnborg
1021de966cf4STim Chenconfig SCHED_MC_PRIO
1022de966cf4STim Chen	bool "CPU core priorities scheduler support"
10230a21fc12SIngo Molnar	depends on SCHED_MC && CPU_SUP_INTEL
10240a21fc12SIngo Molnar	select X86_INTEL_PSTATE
10250a21fc12SIngo Molnar	select CPU_FREQ
1026de966cf4STim Chen	default y
1027a7f7f624SMasahiro Yamada	help
1028de966cf4STim Chen	  Intel Turbo Boost Max Technology 3.0 enabled CPUs have a
1029de966cf4STim Chen	  core ordering determined at manufacturing time, which allows
1030de966cf4STim Chen	  certain cores to reach higher turbo frequencies (when running
1031de966cf4STim Chen	  single threaded workloads) than others.
1032de966cf4STim Chen
1033de966cf4STim Chen	  Enabling this kernel feature teaches the scheduler about
1034de966cf4STim Chen	  the TBM3 (aka ITMT) priority order of the CPU cores and adjusts the
1035de966cf4STim Chen	  scheduler's CPU selection logic accordingly, so that higher
1036de966cf4STim Chen	  overall system performance can be achieved.
1037de966cf4STim Chen
1038de966cf4STim Chen	  This feature will have no effect on CPUs without this feature.
1039de966cf4STim Chen
1040de966cf4STim Chen	  If unsure say Y here.
10415e76b2abSTim Chen
104230b8b006SThomas Gleixnerconfig UP_LATE_INIT
104330b8b006SThomas Gleixner	def_bool y
1044ba360f88SThomas Gleixner	depends on !SMP && X86_LOCAL_APIC
104530b8b006SThomas Gleixner
1046506f1d07SSam Ravnborgconfig X86_UP_APIC
104750849eefSJan Beulich	bool "Local APIC support on uniprocessors" if !PCI_MSI
104850849eefSJan Beulich	default PCI_MSI
104938a1dfdaSBryan O'Donoghue	depends on X86_32 && !SMP && !X86_32_NON_STANDARD
1050a7f7f624SMasahiro Yamada	help
1051506f1d07SSam Ravnborg	  A local APIC (Advanced Programmable Interrupt Controller) is an
1052506f1d07SSam Ravnborg	  integrated interrupt controller in the CPU. If you have a single-CPU
1053506f1d07SSam Ravnborg	  system which has a processor with a local APIC, you can say Y here to
1054506f1d07SSam Ravnborg	  enable and use it. If you say Y here even though your machine doesn't
1055506f1d07SSam Ravnborg	  have a local APIC, then the kernel will still run with no slowdown at
1056506f1d07SSam Ravnborg	  all. The local APIC supports CPU-generated self-interrupts (timer,
1057506f1d07SSam Ravnborg	  performance counters), and the NMI watchdog which detects hard
1058506f1d07SSam Ravnborg	  lockups.
1059506f1d07SSam Ravnborg
1060506f1d07SSam Ravnborgconfig X86_UP_IOAPIC
1061506f1d07SSam Ravnborg	bool "IO-APIC support on uniprocessors"
1062506f1d07SSam Ravnborg	depends on X86_UP_APIC
1063a7f7f624SMasahiro Yamada	help
1064506f1d07SSam Ravnborg	  An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an
1065506f1d07SSam Ravnborg	  SMP-capable replacement for PC-style interrupt controllers. Most
1066506f1d07SSam Ravnborg	  SMP systems and many recent uniprocessor systems have one.
1067506f1d07SSam Ravnborg
1068506f1d07SSam Ravnborg	  If you have a single-CPU system with an IO-APIC, you can say Y here
1069506f1d07SSam Ravnborg	  to use it. If you say Y here even though your machine doesn't have
1070506f1d07SSam Ravnborg	  an IO-APIC, then the kernel will still run with no slowdown at all.
1071506f1d07SSam Ravnborg
1072506f1d07SSam Ravnborgconfig X86_LOCAL_APIC
10733c2362e6SHarvey Harrison	def_bool y
10740dbc6078SThomas Petazzoni	depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC || PCI_MSI
1075b5dc8e6cSJiang Liu	select IRQ_DOMAIN_HIERARCHY
107652f518a3SJiang Liu	select PCI_MSI_IRQ_DOMAIN if PCI_MSI
1077506f1d07SSam Ravnborg
1078506f1d07SSam Ravnborgconfig X86_IO_APIC
1079b1da1e71SJan Beulich	def_bool y
1080b1da1e71SJan Beulich	depends on X86_LOCAL_APIC || X86_UP_IOAPIC
1081506f1d07SSam Ravnborg
108241b9eb26SStefan Assmannconfig X86_REROUTE_FOR_BROKEN_BOOT_IRQS
108341b9eb26SStefan Assmann	bool "Reroute for broken boot IRQs"
108441b9eb26SStefan Assmann	depends on X86_IO_APIC
1085a7f7f624SMasahiro Yamada	help
108641b9eb26SStefan Assmann	  This option enables a workaround that fixes a source of
108741b9eb26SStefan Assmann	  spurious interrupts. This is recommended when threaded
108841b9eb26SStefan Assmann	  interrupt handling is used on systems where the generation of
108941b9eb26SStefan Assmann	  superfluous "boot interrupts" cannot be disabled.
109041b9eb26SStefan Assmann
109141b9eb26SStefan Assmann	  Some chipsets generate a legacy INTx "boot IRQ" when the IRQ
109241b9eb26SStefan Assmann	  entry in the chipset's IO-APIC is masked (as, e.g. the RT
109341b9eb26SStefan Assmann	  kernel does during interrupt handling). On chipsets where this
109441b9eb26SStefan Assmann	  boot IRQ generation cannot be disabled, this workaround keeps
109541b9eb26SStefan Assmann	  the original IRQ line masked so that only the equivalent "boot
109641b9eb26SStefan Assmann	  IRQ" is delivered to the CPUs. The workaround also tells the
109741b9eb26SStefan Assmann	  kernel to set up the IRQ handler on the boot IRQ line. In this
109841b9eb26SStefan Assmann	  way only one interrupt is delivered to the kernel. Otherwise
109941b9eb26SStefan Assmann	  the spurious second interrupt may cause the kernel to bring
110041b9eb26SStefan Assmann	  down (vital) interrupt lines.
110141b9eb26SStefan Assmann
110241b9eb26SStefan Assmann	  Only affects "broken" chipsets. Interrupt sharing may be
110341b9eb26SStefan Assmann	  increased on these systems.
110441b9eb26SStefan Assmann
1105506f1d07SSam Ravnborgconfig X86_MCE
1106bab9bc65SAndi Kleen	bool "Machine Check / overheating reporting"
1107648ed940SChen, Gong	select GENERIC_ALLOCATOR
1108e57dbaf7SBorislav Petkov	default y
1109a7f7f624SMasahiro Yamada	help
1110bab9bc65SAndi Kleen	  Machine Check support allows the processor to notify the
1111bab9bc65SAndi Kleen	  kernel if it detects a problem (e.g. overheating, data corruption).
1112506f1d07SSam Ravnborg	  The action the kernel takes depends on the severity of the problem,
1113bab9bc65SAndi Kleen	  ranging from warning messages to halting the machine.
11144efc0670SAndi Kleen
11155de97c9fSTony Luckconfig X86_MCELOG_LEGACY
11165de97c9fSTony Luck	bool "Support for deprecated /dev/mcelog character device"
11175de97c9fSTony Luck	depends on X86_MCE
1118a7f7f624SMasahiro Yamada	help
11195de97c9fSTony Luck	  Enable support for /dev/mcelog which is needed by the old mcelog
11205de97c9fSTony Luck	  userspace logging daemon. Consider switching to the new generation
11215de97c9fSTony Luck	  rasdaemon solution.
11225de97c9fSTony Luck
1123506f1d07SSam Ravnborgconfig X86_MCE_INTEL
11243c2362e6SHarvey Harrison	def_bool y
11253c2362e6SHarvey Harrison	prompt "Intel MCE features"
1126c1ebf835SAndi Kleen	depends on X86_MCE && X86_LOCAL_APIC
1127a7f7f624SMasahiro Yamada	help
1128506f1d07SSam Ravnborg	   Additional support for intel specific MCE features such as
1129506f1d07SSam Ravnborg	   the thermal monitor.
1130506f1d07SSam Ravnborg
1131506f1d07SSam Ravnborgconfig X86_MCE_AMD
11323c2362e6SHarvey Harrison	def_bool y
11333c2362e6SHarvey Harrison	prompt "AMD MCE features"
1134f5382de9SYazen Ghannam	depends on X86_MCE && X86_LOCAL_APIC && AMD_NB
1135a7f7f624SMasahiro Yamada	help
1136506f1d07SSam Ravnborg	   Additional support for AMD specific MCE features such as
1137506f1d07SSam Ravnborg	   the DRAM Error Threshold.
1138506f1d07SSam Ravnborg
11394efc0670SAndi Kleenconfig X86_ANCIENT_MCE
11406fc108a0SJan Beulich	bool "Support for old Pentium 5 / WinChip machine checks"
1141c31d9633SAndi Kleen	depends on X86_32 && X86_MCE
1142a7f7f624SMasahiro Yamada	help
11434efc0670SAndi Kleen	  Include support for machine check handling on old Pentium 5 or WinChip
11445065a706SMasanari Iida	  systems. These typically need to be enabled explicitly on the command
11454efc0670SAndi Kleen	  line.
11464efc0670SAndi Kleen
1147b2762686SAndi Kleenconfig X86_MCE_THRESHOLD
1148b2762686SAndi Kleen	depends on X86_MCE_AMD || X86_MCE_INTEL
11496fc108a0SJan Beulich	def_bool y
1150b2762686SAndi Kleen
1151ea149b36SAndi Kleenconfig X86_MCE_INJECT
1152bc8e80d5SBorislav Petkov	depends on X86_MCE && X86_LOCAL_APIC && DEBUG_FS
1153ea149b36SAndi Kleen	tristate "Machine check injector support"
1154a7f7f624SMasahiro Yamada	help
1155ea149b36SAndi Kleen	  Provide support for injecting machine checks for testing purposes.
1156ea149b36SAndi Kleen	  If you don't know what a machine check is and you don't do kernel
1157ea149b36SAndi Kleen	  QA it is safe to say n.
1158ea149b36SAndi Kleen
11594efc0670SAndi Kleenconfig X86_THERMAL_VECTOR
11604efc0670SAndi Kleen	def_bool y
11615bb38adcSAndi Kleen	depends on X86_MCE_INTEL
11624efc0670SAndi Kleen
116307dc900eSPeter Zijlstrasource "arch/x86/events/Kconfig"
1164e633c65aSKan Liang
11655aef51c3SAndy Lutomirskiconfig X86_LEGACY_VM86
11661e642812SIngo Molnar	bool "Legacy VM86 support"
1167506f1d07SSam Ravnborg	depends on X86_32
1168a7f7f624SMasahiro Yamada	help
11695aef51c3SAndy Lutomirski	  This option allows user programs to put the CPU into V8086
11705aef51c3SAndy Lutomirski	  mode, which is an 80286-era approximation of 16-bit real mode.
11715aef51c3SAndy Lutomirski
11725aef51c3SAndy Lutomirski	  Some very old versions of X and/or vbetool require this option
11735aef51c3SAndy Lutomirski	  for user mode setting.  Similarly, DOSEMU will use it if
11745aef51c3SAndy Lutomirski	  available to accelerate real mode DOS programs.  However, any
11755aef51c3SAndy Lutomirski	  recent version of DOSEMU, X, or vbetool should be fully
11765aef51c3SAndy Lutomirski	  functional even without kernel VM86 support, as they will all
11771e642812SIngo Molnar	  fall back to software emulation. Nevertheless, if you are using
11781e642812SIngo Molnar	  a 16-bit DOS program where 16-bit performance matters, vm86
11791e642812SIngo Molnar	  mode might be faster than emulation and you might want to
11801e642812SIngo Molnar	  enable this option.
11815aef51c3SAndy Lutomirski
11821e642812SIngo Molnar	  Note that any app that works on a 64-bit kernel is unlikely to
11831e642812SIngo Molnar	  need this option, as 64-bit kernels don't, and can't, support
11841e642812SIngo Molnar	  V8086 mode. This option is also unrelated to 16-bit protected
11851e642812SIngo Molnar	  mode and is not needed to run most 16-bit programs under Wine.
11865aef51c3SAndy Lutomirski
11871e642812SIngo Molnar	  Enabling this option increases the complexity of the kernel
11881e642812SIngo Molnar	  and slows down exception handling a tiny bit.
11895aef51c3SAndy Lutomirski
11901e642812SIngo Molnar	  If unsure, say N here.
11915aef51c3SAndy Lutomirski
11925aef51c3SAndy Lutomirskiconfig VM86
11935aef51c3SAndy Lutomirski	bool
11945aef51c3SAndy Lutomirski	default X86_LEGACY_VM86
119534273f41SH. Peter Anvin
119634273f41SH. Peter Anvinconfig X86_16BIT
119734273f41SH. Peter Anvin	bool "Enable support for 16-bit segments" if EXPERT
119834273f41SH. Peter Anvin	default y
1199a5b9e5a2SAndy Lutomirski	depends on MODIFY_LDT_SYSCALL
1200a7f7f624SMasahiro Yamada	help
120134273f41SH. Peter Anvin	  This option is required by programs like Wine to run 16-bit
120234273f41SH. Peter Anvin	  protected mode legacy code on x86 processors.  Disabling
120334273f41SH. Peter Anvin	  this option saves about 300 bytes on i386, or around 6K text
120434273f41SH. Peter Anvin	  plus 16K runtime memory on x86-64,
120534273f41SH. Peter Anvin
120634273f41SH. Peter Anvinconfig X86_ESPFIX32
120734273f41SH. Peter Anvin	def_bool y
120834273f41SH. Peter Anvin	depends on X86_16BIT && X86_32
1209506f1d07SSam Ravnborg
1210197725deSH. Peter Anvinconfig X86_ESPFIX64
1211197725deSH. Peter Anvin	def_bool y
121234273f41SH. Peter Anvin	depends on X86_16BIT && X86_64
1213506f1d07SSam Ravnborg
12141ad83c85SAndy Lutomirskiconfig X86_VSYSCALL_EMULATION
12151ad83c85SAndy Lutomirski	bool "Enable vsyscall emulation" if EXPERT
12161ad83c85SAndy Lutomirski	default y
12171ad83c85SAndy Lutomirski	depends on X86_64
1218a7f7f624SMasahiro Yamada	help
12191ad83c85SAndy Lutomirski	 This enables emulation of the legacy vsyscall page.  Disabling
12201ad83c85SAndy Lutomirski	 it is roughly equivalent to booting with vsyscall=none, except
12211ad83c85SAndy Lutomirski	 that it will also disable the helpful warning if a program
12221ad83c85SAndy Lutomirski	 tries to use a vsyscall.  With this option set to N, offending
12231ad83c85SAndy Lutomirski	 programs will just segfault, citing addresses of the form
12241ad83c85SAndy Lutomirski	 0xffffffffff600?00.
12251ad83c85SAndy Lutomirski
12261ad83c85SAndy Lutomirski	 This option is required by many programs built before 2013, and
12271ad83c85SAndy Lutomirski	 care should be used even with newer programs if set to N.
12281ad83c85SAndy Lutomirski
12291ad83c85SAndy Lutomirski	 Disabling this option saves about 7K of kernel size and
12301ad83c85SAndy Lutomirski	 possibly 4K of additional runtime pagetable memory.
12311ad83c85SAndy Lutomirski
1232111e7b15SThomas Gleixnerconfig X86_IOPL_IOPERM
1233111e7b15SThomas Gleixner	bool "IOPERM and IOPL Emulation"
1234a24ca997SThomas Gleixner	default y
1235a7f7f624SMasahiro Yamada	help
1236111e7b15SThomas Gleixner	  This enables the ioperm() and iopl() syscalls which are necessary
1237111e7b15SThomas Gleixner	  for legacy applications.
1238111e7b15SThomas Gleixner
1239c8137aceSThomas Gleixner	  Legacy IOPL support is an overbroad mechanism which allows user
1240c8137aceSThomas Gleixner	  space aside of accessing all 65536 I/O ports also to disable
1241c8137aceSThomas Gleixner	  interrupts. To gain this access the caller needs CAP_SYS_RAWIO
1242c8137aceSThomas Gleixner	  capabilities and permission from potentially active security
1243c8137aceSThomas Gleixner	  modules.
1244c8137aceSThomas Gleixner
1245c8137aceSThomas Gleixner	  The emulation restricts the functionality of the syscall to
1246c8137aceSThomas Gleixner	  only allowing the full range I/O port access, but prevents the
1247a24ca997SThomas Gleixner	  ability to disable interrupts from user space which would be
1248a24ca997SThomas Gleixner	  granted if the hardware IOPL mechanism would be used.
1249c8137aceSThomas Gleixner
1250506f1d07SSam Ravnborgconfig TOSHIBA
1251506f1d07SSam Ravnborg	tristate "Toshiba Laptop support"
1252506f1d07SSam Ravnborg	depends on X86_32
1253a7f7f624SMasahiro Yamada	help
1254506f1d07SSam Ravnborg	  This adds a driver to safely access the System Management Mode of
1255506f1d07SSam Ravnborg	  the CPU on Toshiba portables with a genuine Toshiba BIOS. It does
1256506f1d07SSam Ravnborg	  not work on models with a Phoenix BIOS. The System Management Mode
1257506f1d07SSam Ravnborg	  is used to set the BIOS and power saving options on Toshiba portables.
1258506f1d07SSam Ravnborg
1259506f1d07SSam Ravnborg	  For information on utilities to make use of this driver see the
1260506f1d07SSam Ravnborg	  Toshiba Linux utilities web site at:
1261506f1d07SSam Ravnborg	  <http://www.buzzard.org.uk/toshiba/>.
1262506f1d07SSam Ravnborg
1263506f1d07SSam Ravnborg	  Say Y if you intend to run this kernel on a Toshiba portable.
1264506f1d07SSam Ravnborg	  Say N otherwise.
1265506f1d07SSam Ravnborg
1266506f1d07SSam Ravnborgconfig I8K
1267039ae585SPali Rohár	tristate "Dell i8k legacy laptop support"
1268949a9d70SJean Delvare	select HWMON
1269039ae585SPali Rohár	select SENSORS_DELL_SMM
1270a7f7f624SMasahiro Yamada	help
1271039ae585SPali Rohár	  This option enables legacy /proc/i8k userspace interface in hwmon
1272039ae585SPali Rohár	  dell-smm-hwmon driver. Character file /proc/i8k reports bios version,
1273039ae585SPali Rohár	  temperature and allows controlling fan speeds of Dell laptops via
1274039ae585SPali Rohár	  System Management Mode. For old Dell laptops (like Dell Inspiron 8000)
1275039ae585SPali Rohár	  it reports also power and hotkey status. For fan speed control is
1276039ae585SPali Rohár	  needed userspace package i8kutils.
1277506f1d07SSam Ravnborg
1278039ae585SPali Rohár	  Say Y if you intend to run this kernel on old Dell laptops or want to
1279039ae585SPali Rohár	  use userspace package i8kutils.
1280506f1d07SSam Ravnborg	  Say N otherwise.
1281506f1d07SSam Ravnborg
1282506f1d07SSam Ravnborgconfig X86_REBOOTFIXUPS
12839ba16087SJan Beulich	bool "Enable X86 board specific fixups for reboot"
12849ba16087SJan Beulich	depends on X86_32
1285a7f7f624SMasahiro Yamada	help
1286506f1d07SSam Ravnborg	  This enables chipset and/or board specific fixups to be done
1287506f1d07SSam Ravnborg	  in order to get reboot to work correctly. This is only needed on
1288506f1d07SSam Ravnborg	  some combinations of hardware and BIOS. The symptom, for which
1289506f1d07SSam Ravnborg	  this config is intended, is when reboot ends with a stalled/hung
1290506f1d07SSam Ravnborg	  system.
1291506f1d07SSam Ravnborg
1292506f1d07SSam Ravnborg	  Currently, the only fixup is for the Geode machines using
12935e3a77e9SFlorian Fainelli	  CS5530A and CS5536 chipsets and the RDC R-321x SoC.
1294506f1d07SSam Ravnborg
1295506f1d07SSam Ravnborg	  Say Y if you want to enable the fixup. Currently, it's safe to
1296506f1d07SSam Ravnborg	  enable this option even if you don't need it.
1297506f1d07SSam Ravnborg	  Say N otherwise.
1298506f1d07SSam Ravnborg
1299506f1d07SSam Ravnborgconfig MICROCODE
13009a2bc335SBorislav Petkov	bool "CPU microcode loading support"
13019a2bc335SBorislav Petkov	default y
130280030e3dSBorislav Petkov	depends on CPU_SUP_AMD || CPU_SUP_INTEL
1303a7f7f624SMasahiro Yamada	help
1304506f1d07SSam Ravnborg	  If you say Y here, you will be able to update the microcode on
13055f9c01aaSBorislav Petkov	  Intel and AMD processors. The Intel support is for the IA32 family,
13065f9c01aaSBorislav Petkov	  e.g. Pentium Pro, Pentium II, Pentium III, Pentium 4, Xeon etc. The
13075f9c01aaSBorislav Petkov	  AMD support is for families 0x10 and later. You will obviously need
13085f9c01aaSBorislav Petkov	  the actual microcode binary data itself which is not shipped with
13095f9c01aaSBorislav Petkov	  the Linux kernel.
1310506f1d07SSam Ravnborg
13115f9c01aaSBorislav Petkov	  The preferred method to load microcode from a detached initrd is described
1312cb1aaebeSMauro Carvalho Chehab	  in Documentation/x86/microcode.rst. For that you need to enable
13135f9c01aaSBorislav Petkov	  CONFIG_BLK_DEV_INITRD in order for the loader to be able to scan the
13145f9c01aaSBorislav Petkov	  initrd for microcode blobs.
1315506f1d07SSam Ravnborg
1316c508c46eSBenjamin Gilbert	  In addition, you can build the microcode into the kernel. For that you
1317c508c46eSBenjamin Gilbert	  need to add the vendor-supplied microcode to the CONFIG_EXTRA_FIRMWARE
1318c508c46eSBenjamin Gilbert	  config option.
1319506f1d07SSam Ravnborg
13208d86f390SPeter Orubaconfig MICROCODE_INTEL
1321e43f6e67SBorislav Petkov	bool "Intel microcode loading support"
13228d86f390SPeter Oruba	depends on MICROCODE
13238d86f390SPeter Oruba	default MICROCODE
1324a7f7f624SMasahiro Yamada	help
13258d86f390SPeter Oruba	  This options enables microcode patch loading support for Intel
13268d86f390SPeter Oruba	  processors.
13278d86f390SPeter Oruba
1328b8989db9SAlan	  For the current Intel microcode data package go to
1329b8989db9SAlan	  <https://downloadcenter.intel.com> and search for
1330b8989db9SAlan	  'Linux Processor Microcode Data File'.
13318d86f390SPeter Oruba
133280cc9f10SPeter Orubaconfig MICROCODE_AMD
1333e43f6e67SBorislav Petkov	bool "AMD microcode loading support"
133480cc9f10SPeter Oruba	depends on MICROCODE
1335a7f7f624SMasahiro Yamada	help
133680cc9f10SPeter Oruba	  If you select this option, microcode patch loading support for AMD
133780cc9f10SPeter Oruba	  processors will be enabled.
133880cc9f10SPeter Oruba
1339506f1d07SSam Ravnborgconfig MICROCODE_OLD_INTERFACE
1340c02f48e0SBorislav Petkov	bool "Ancient loading interface (DEPRECATED)"
1341c02f48e0SBorislav Petkov	default n
1342506f1d07SSam Ravnborg	depends on MICROCODE
1343a7f7f624SMasahiro Yamada	help
1344c02f48e0SBorislav Petkov	  DO NOT USE THIS! This is the ancient /dev/cpu/microcode interface
1345c02f48e0SBorislav Petkov	  which was used by userspace tools like iucode_tool and microcode.ctl.
1346c02f48e0SBorislav Petkov	  It is inadequate because it runs too late to be able to properly
1347c02f48e0SBorislav Petkov	  load microcode on a machine and it needs special tools. Instead, you
1348c02f48e0SBorislav Petkov	  should've switched to the early loading method with the initrd or
1349cb1aaebeSMauro Carvalho Chehab	  builtin microcode by now: Documentation/x86/microcode.rst
1350506f1d07SSam Ravnborg
1351506f1d07SSam Ravnborgconfig X86_MSR
1352506f1d07SSam Ravnborg	tristate "/dev/cpu/*/msr - Model-specific register support"
1353a7f7f624SMasahiro Yamada	help
1354506f1d07SSam Ravnborg	  This device gives privileged processes access to the x86
1355506f1d07SSam Ravnborg	  Model-Specific Registers (MSRs).  It is a character device with
1356506f1d07SSam Ravnborg	  major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr.
1357506f1d07SSam Ravnborg	  MSR accesses are directed to a specific CPU on multi-processor
1358506f1d07SSam Ravnborg	  systems.
1359506f1d07SSam Ravnborg
1360506f1d07SSam Ravnborgconfig X86_CPUID
1361506f1d07SSam Ravnborg	tristate "/dev/cpu/*/cpuid - CPU information support"
1362a7f7f624SMasahiro Yamada	help
1363506f1d07SSam Ravnborg	  This device gives processes access to the x86 CPUID instruction to
1364506f1d07SSam Ravnborg	  be executed on a specific processor.  It is a character device
1365506f1d07SSam Ravnborg	  with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to
1366506f1d07SSam Ravnborg	  /dev/cpu/31/cpuid.
1367506f1d07SSam Ravnborg
1368506f1d07SSam Ravnborgchoice
1369506f1d07SSam Ravnborg	prompt "High Memory Support"
13706fc108a0SJan Beulich	default HIGHMEM4G
1371506f1d07SSam Ravnborg	depends on X86_32
1372506f1d07SSam Ravnborg
1373506f1d07SSam Ravnborgconfig NOHIGHMEM
1374506f1d07SSam Ravnborg	bool "off"
1375a7f7f624SMasahiro Yamada	help
1376506f1d07SSam Ravnborg	  Linux can use up to 64 Gigabytes of physical memory on x86 systems.
1377506f1d07SSam Ravnborg	  However, the address space of 32-bit x86 processors is only 4
1378506f1d07SSam Ravnborg	  Gigabytes large. That means that, if you have a large amount of
1379506f1d07SSam Ravnborg	  physical memory, not all of it can be "permanently mapped" by the
1380506f1d07SSam Ravnborg	  kernel. The physical memory that's not permanently mapped is called
1381506f1d07SSam Ravnborg	  "high memory".
1382506f1d07SSam Ravnborg
1383506f1d07SSam Ravnborg	  If you are compiling a kernel which will never run on a machine with
1384506f1d07SSam Ravnborg	  more than 1 Gigabyte total physical RAM, answer "off" here (default
1385506f1d07SSam Ravnborg	  choice and suitable for most users). This will result in a "3GB/1GB"
1386506f1d07SSam Ravnborg	  split: 3GB are mapped so that each process sees a 3GB virtual memory
1387506f1d07SSam Ravnborg	  space and the remaining part of the 4GB virtual memory space is used
1388506f1d07SSam Ravnborg	  by the kernel to permanently map as much physical memory as
1389506f1d07SSam Ravnborg	  possible.
1390506f1d07SSam Ravnborg
1391506f1d07SSam Ravnborg	  If the machine has between 1 and 4 Gigabytes physical RAM, then
1392506f1d07SSam Ravnborg	  answer "4GB" here.
1393506f1d07SSam Ravnborg
1394506f1d07SSam Ravnborg	  If more than 4 Gigabytes is used then answer "64GB" here. This
1395506f1d07SSam Ravnborg	  selection turns Intel PAE (Physical Address Extension) mode on.
1396506f1d07SSam Ravnborg	  PAE implements 3-level paging on IA32 processors. PAE is fully
1397506f1d07SSam Ravnborg	  supported by Linux, PAE mode is implemented on all recent Intel
1398506f1d07SSam Ravnborg	  processors (Pentium Pro and better). NOTE: If you say "64GB" here,
1399506f1d07SSam Ravnborg	  then the kernel will not boot on CPUs that don't support PAE!
1400506f1d07SSam Ravnborg
1401506f1d07SSam Ravnborg	  The actual amount of total physical memory will either be
1402506f1d07SSam Ravnborg	  auto detected or can be forced by using a kernel command line option
1403506f1d07SSam Ravnborg	  such as "mem=256M". (Try "man bootparam" or see the documentation of
1404506f1d07SSam Ravnborg	  your boot loader (lilo or loadlin) about how to pass options to the
1405506f1d07SSam Ravnborg	  kernel at boot time.)
1406506f1d07SSam Ravnborg
1407506f1d07SSam Ravnborg	  If unsure, say "off".
1408506f1d07SSam Ravnborg
1409506f1d07SSam Ravnborgconfig HIGHMEM4G
1410506f1d07SSam Ravnborg	bool "4GB"
1411a7f7f624SMasahiro Yamada	help
1412506f1d07SSam Ravnborg	  Select this if you have a 32-bit processor and between 1 and 4
1413506f1d07SSam Ravnborg	  gigabytes of physical RAM.
1414506f1d07SSam Ravnborg
1415506f1d07SSam Ravnborgconfig HIGHMEM64G
1416506f1d07SSam Ravnborg	bool "64GB"
141769b8d3fcSMatthew Whitehead	depends on !M486 && !M586 && !M586TSC && !M586MMX && !MGEODE_LX && !MGEODEGX1 && !MCYRIXIII && !MELAN && !MWINCHIPC6 && !WINCHIP3D && !MK6
1418506f1d07SSam Ravnborg	select X86_PAE
1419a7f7f624SMasahiro Yamada	help
1420506f1d07SSam Ravnborg	  Select this if you have a 32-bit processor and more than 4
1421506f1d07SSam Ravnborg	  gigabytes of physical RAM.
1422506f1d07SSam Ravnborg
1423506f1d07SSam Ravnborgendchoice
1424506f1d07SSam Ravnborg
1425506f1d07SSam Ravnborgchoice
14266a108a14SDavid Rientjes	prompt "Memory split" if EXPERT
1427506f1d07SSam Ravnborg	default VMSPLIT_3G
1428506f1d07SSam Ravnborg	depends on X86_32
1429a7f7f624SMasahiro Yamada	help
1430506f1d07SSam Ravnborg	  Select the desired split between kernel and user memory.
1431506f1d07SSam Ravnborg
1432506f1d07SSam Ravnborg	  If the address range available to the kernel is less than the
1433506f1d07SSam Ravnborg	  physical memory installed, the remaining memory will be available
1434506f1d07SSam Ravnborg	  as "high memory". Accessing high memory is a little more costly
1435506f1d07SSam Ravnborg	  than low memory, as it needs to be mapped into the kernel first.
1436506f1d07SSam Ravnborg	  Note that increasing the kernel address space limits the range
1437506f1d07SSam Ravnborg	  available to user programs, making the address space there
1438506f1d07SSam Ravnborg	  tighter.  Selecting anything other than the default 3G/1G split
1439506f1d07SSam Ravnborg	  will also likely make your kernel incompatible with binary-only
1440506f1d07SSam Ravnborg	  kernel modules.
1441506f1d07SSam Ravnborg
1442506f1d07SSam Ravnborg	  If you are not absolutely sure what you are doing, leave this
1443506f1d07SSam Ravnborg	  option alone!
1444506f1d07SSam Ravnborg
1445506f1d07SSam Ravnborg	config VMSPLIT_3G
1446506f1d07SSam Ravnborg		bool "3G/1G user/kernel split"
1447506f1d07SSam Ravnborg	config VMSPLIT_3G_OPT
1448506f1d07SSam Ravnborg		depends on !X86_PAE
1449506f1d07SSam Ravnborg		bool "3G/1G user/kernel split (for full 1G low memory)"
1450506f1d07SSam Ravnborg	config VMSPLIT_2G
1451506f1d07SSam Ravnborg		bool "2G/2G user/kernel split"
1452506f1d07SSam Ravnborg	config VMSPLIT_2G_OPT
1453506f1d07SSam Ravnborg		depends on !X86_PAE
1454506f1d07SSam Ravnborg		bool "2G/2G user/kernel split (for full 2G low memory)"
1455506f1d07SSam Ravnborg	config VMSPLIT_1G
1456506f1d07SSam Ravnborg		bool "1G/3G user/kernel split"
1457506f1d07SSam Ravnborgendchoice
1458506f1d07SSam Ravnborg
1459506f1d07SSam Ravnborgconfig PAGE_OFFSET
1460506f1d07SSam Ravnborg	hex
1461506f1d07SSam Ravnborg	default 0xB0000000 if VMSPLIT_3G_OPT
1462506f1d07SSam Ravnborg	default 0x80000000 if VMSPLIT_2G
1463506f1d07SSam Ravnborg	default 0x78000000 if VMSPLIT_2G_OPT
1464506f1d07SSam Ravnborg	default 0x40000000 if VMSPLIT_1G
1465506f1d07SSam Ravnborg	default 0xC0000000
1466506f1d07SSam Ravnborg	depends on X86_32
1467506f1d07SSam Ravnborg
1468506f1d07SSam Ravnborgconfig HIGHMEM
14693c2362e6SHarvey Harrison	def_bool y
1470506f1d07SSam Ravnborg	depends on X86_32 && (HIGHMEM64G || HIGHMEM4G)
1471506f1d07SSam Ravnborg
1472506f1d07SSam Ravnborgconfig X86_PAE
14739ba16087SJan Beulich	bool "PAE (Physical Address Extension) Support"
1474506f1d07SSam Ravnborg	depends on X86_32 && !HIGHMEM4G
1475d4a451d5SChristoph Hellwig	select PHYS_ADDR_T_64BIT
14769d99c712SChristian Melki	select SWIOTLB
1477a7f7f624SMasahiro Yamada	help
1478506f1d07SSam Ravnborg	  PAE is required for NX support, and furthermore enables
1479506f1d07SSam Ravnborg	  larger swapspace support for non-overcommit purposes. It
1480506f1d07SSam Ravnborg	  has the cost of more pagetable lookup overhead, and also
1481506f1d07SSam Ravnborg	  consumes more pagetable space per process.
1482506f1d07SSam Ravnborg
148377ef56e4SKirill A. Shutemovconfig X86_5LEVEL
148477ef56e4SKirill A. Shutemov	bool "Enable 5-level page tables support"
148518ec1eafSKirill A. Shutemov	default y
1486eedb92abSKirill A. Shutemov	select DYNAMIC_MEMORY_LAYOUT
1487162434e7SKirill A. Shutemov	select SPARSEMEM_VMEMMAP
148877ef56e4SKirill A. Shutemov	depends on X86_64
1489a7f7f624SMasahiro Yamada	help
149077ef56e4SKirill A. Shutemov	  5-level paging enables access to larger address space:
149177ef56e4SKirill A. Shutemov	  upto 128 PiB of virtual address space and 4 PiB of
149277ef56e4SKirill A. Shutemov	  physical address space.
149377ef56e4SKirill A. Shutemov
149477ef56e4SKirill A. Shutemov	  It will be supported by future Intel CPUs.
149577ef56e4SKirill A. Shutemov
14966657fca0SKirill A. Shutemov	  A kernel with the option enabled can be booted on machines that
14976657fca0SKirill A. Shutemov	  support 4- or 5-level paging.
149877ef56e4SKirill A. Shutemov
1499cb1aaebeSMauro Carvalho Chehab	  See Documentation/x86/x86_64/5level-paging.rst for more
150077ef56e4SKirill A. Shutemov	  information.
150177ef56e4SKirill A. Shutemov
150277ef56e4SKirill A. Shutemov	  Say N if unsure.
150377ef56e4SKirill A. Shutemov
150410971ab2SIngo Molnarconfig X86_DIRECT_GBPAGES
1505e5008abeSLuis R. Rodriguez	def_bool y
15062e1da13fSVlastimil Babka	depends on X86_64
1507a7f7f624SMasahiro Yamada	help
150810971ab2SIngo Molnar	  Certain kernel features effectively disable kernel
150910971ab2SIngo Molnar	  linear 1 GB mappings (even if the CPU otherwise
151010971ab2SIngo Molnar	  supports them), so don't confuse the user by printing
151110971ab2SIngo Molnar	  that we have them enabled.
15129e899816SNick Piggin
15135c280cf6SThomas Gleixnerconfig X86_CPA_STATISTICS
15145c280cf6SThomas Gleixner	bool "Enable statistic for Change Page Attribute"
15155c280cf6SThomas Gleixner	depends on DEBUG_FS
1516a7f7f624SMasahiro Yamada	help
1517b75baaf3SIngo Molnar	  Expose statistics about the Change Page Attribute mechanism, which
1518a943245aSColin Ian King	  helps to determine the effectiveness of preserving large and huge
15195c280cf6SThomas Gleixner	  page mappings when mapping protections are changed.
15205c280cf6SThomas Gleixner
15217744ccdbSTom Lendackyconfig AMD_MEM_ENCRYPT
15227744ccdbSTom Lendacky	bool "AMD Secure Memory Encryption (SME) support"
15237744ccdbSTom Lendacky	depends on X86_64 && CPU_SUP_AMD
152482fef0adSDavid Rientjes	select DMA_COHERENT_POOL
152594d49eb3SKirill A. Shutemov	select DYNAMIC_PHYSICAL_MASK
1526ce9084baSArd Biesheuvel	select ARCH_USE_MEMREMAP_PROT
15279087c375STom Lendacky	select ARCH_HAS_FORCE_DMA_UNENCRYPTED
1528597cfe48SJoerg Roedel	select INSTRUCTION_DECODER
1529a7f7f624SMasahiro Yamada	help
15307744ccdbSTom Lendacky	  Say yes to enable support for the encryption of system memory.
15317744ccdbSTom Lendacky	  This requires an AMD processor that supports Secure Memory
15327744ccdbSTom Lendacky	  Encryption (SME).
15337744ccdbSTom Lendacky
15347744ccdbSTom Lendackyconfig AMD_MEM_ENCRYPT_ACTIVE_BY_DEFAULT
15357744ccdbSTom Lendacky	bool "Activate AMD Secure Memory Encryption (SME) by default"
15367744ccdbSTom Lendacky	default y
15377744ccdbSTom Lendacky	depends on AMD_MEM_ENCRYPT
1538a7f7f624SMasahiro Yamada	help
15397744ccdbSTom Lendacky	  Say yes to have system memory encrypted by default if running on
15407744ccdbSTom Lendacky	  an AMD processor that supports Secure Memory Encryption (SME).
15417744ccdbSTom Lendacky
15427744ccdbSTom Lendacky	  If set to Y, then the encryption of system memory can be
15437744ccdbSTom Lendacky	  deactivated with the mem_encrypt=off command line option.
15447744ccdbSTom Lendacky
15457744ccdbSTom Lendacky	  If set to N, then the encryption of system memory can be
15467744ccdbSTom Lendacky	  activated with the mem_encrypt=on command line option.
15477744ccdbSTom Lendacky
1548506f1d07SSam Ravnborg# Common NUMA Features
1549506f1d07SSam Ravnborgconfig NUMA
1550e133f6eaSRandy Dunlap	bool "NUMA Memory Allocation and Scheduler Support"
1551506f1d07SSam Ravnborg	depends on SMP
1552b5660ba7SH. Peter Anvin	depends on X86_64 || (X86_32 && HIGHMEM64G && X86_BIGSMP)
1553b5660ba7SH. Peter Anvin	default y if X86_BIGSMP
1554a7f7f624SMasahiro Yamada	help
1555e133f6eaSRandy Dunlap	  Enable NUMA (Non-Uniform Memory Access) support.
1556fd51b2d7SKOSAKI Motohiro
1557506f1d07SSam Ravnborg	  The kernel will try to allocate memory used by a CPU on the
1558506f1d07SSam Ravnborg	  local memory controller of the CPU and add some more
1559506f1d07SSam Ravnborg	  NUMA awareness to the kernel.
1560506f1d07SSam Ravnborg
1561c280ea5eSIngo Molnar	  For 64-bit this is recommended if the system is Intel Core i7
1562fd51b2d7SKOSAKI Motohiro	  (or later), AMD Opteron, or EM64T NUMA.
1563fd51b2d7SKOSAKI Motohiro
1564b5660ba7SH. Peter Anvin	  For 32-bit this is only needed if you boot a 32-bit
15657cf6c945SDavid Rientjes	  kernel on a 64-bit NUMA platform.
1566fd51b2d7SKOSAKI Motohiro
1567fd51b2d7SKOSAKI Motohiro	  Otherwise, you should say N.
1568506f1d07SSam Ravnborg
1569eec1d4faSHans Rosenfeldconfig AMD_NUMA
15703c2362e6SHarvey Harrison	def_bool y
15713c2362e6SHarvey Harrison	prompt "Old style AMD Opteron NUMA detection"
15725da0ef9aSTejun Heo	depends on X86_64 && NUMA && PCI
1573a7f7f624SMasahiro Yamada	help
1574eec1d4faSHans Rosenfeld	  Enable AMD NUMA node topology detection.  You should say Y here if
1575eec1d4faSHans Rosenfeld	  you have a multi processor AMD system. This uses an old method to
1576eec1d4faSHans Rosenfeld	  read the NUMA configuration directly from the builtin Northbridge
1577eec1d4faSHans Rosenfeld	  of Opteron. It is recommended to use X86_64_ACPI_NUMA instead,
1578eec1d4faSHans Rosenfeld	  which also takes priority if both are compiled in.
1579506f1d07SSam Ravnborg
1580506f1d07SSam Ravnborgconfig X86_64_ACPI_NUMA
15813c2362e6SHarvey Harrison	def_bool y
15823c2362e6SHarvey Harrison	prompt "ACPI NUMA detection"
1583506f1d07SSam Ravnborg	depends on X86_64 && NUMA && ACPI && PCI
1584506f1d07SSam Ravnborg	select ACPI_NUMA
1585a7f7f624SMasahiro Yamada	help
1586506f1d07SSam Ravnborg	  Enable ACPI SRAT based node topology detection.
1587506f1d07SSam Ravnborg
1588506f1d07SSam Ravnborgconfig NUMA_EMU
1589506f1d07SSam Ravnborg	bool "NUMA emulation"
15901b7e03efSTejun Heo	depends on NUMA
1591a7f7f624SMasahiro Yamada	help
1592506f1d07SSam Ravnborg	  Enable NUMA emulation. A flat machine will be split
1593506f1d07SSam Ravnborg	  into virtual nodes when booted with "numa=fake=N", where N is the
1594506f1d07SSam Ravnborg	  number of nodes. This is only useful for debugging.
1595506f1d07SSam Ravnborg
1596506f1d07SSam Ravnborgconfig NODES_SHIFT
1597d25e26b6SLinus Torvalds	int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP
159851591e31SDavid Rientjes	range 1 10
159951591e31SDavid Rientjes	default "10" if MAXSMP
1600506f1d07SSam Ravnborg	default "6" if X86_64
1601506f1d07SSam Ravnborg	default "3"
1602506f1d07SSam Ravnborg	depends on NEED_MULTIPLE_NODES
1603a7f7f624SMasahiro Yamada	help
16041184dc2fSMike Travis	  Specify the maximum number of NUMA Nodes available on the target
1605692105b8SMatt LaPlante	  system.  Increases memory reserved to accommodate various tables.
1606506f1d07SSam Ravnborg
1607506f1d07SSam Ravnborgconfig ARCH_FLATMEM_ENABLE
1608506f1d07SSam Ravnborg	def_bool y
16093b16651fSTejun Heo	depends on X86_32 && !NUMA
1610506f1d07SSam Ravnborg
1611506f1d07SSam Ravnborgconfig ARCH_SPARSEMEM_ENABLE
1612506f1d07SSam Ravnborg	def_bool y
16136ea30386SKees Cook	depends on X86_64 || NUMA || X86_32 || X86_32_NON_STANDARD
1614506f1d07SSam Ravnborg	select SPARSEMEM_STATIC if X86_32
1615506f1d07SSam Ravnborg	select SPARSEMEM_VMEMMAP_ENABLE if X86_64
1616506f1d07SSam Ravnborg
16173b16651fSTejun Heoconfig ARCH_SPARSEMEM_DEFAULT
16186ad57f7fSMike Rapoport	def_bool X86_64 || (NUMA && X86_32)
16193b16651fSTejun Heo
1620506f1d07SSam Ravnborgconfig ARCH_SELECT_MEMORY_MODEL
1621506f1d07SSam Ravnborg	def_bool y
1622b263295dSChristoph Lameter	depends on ARCH_SPARSEMEM_ENABLE
1623506f1d07SSam Ravnborg
1624506f1d07SSam Ravnborgconfig ARCH_MEMORY_PROBE
1625a0842b70SToshi Kani	bool "Enable sysfs memory/probe interface"
16263120e25eSJan Beulich	depends on X86_64 && MEMORY_HOTPLUG
1627a0842b70SToshi Kani	help
1628a0842b70SToshi Kani	  This option enables a sysfs memory/probe interface for testing.
1629cb1aaebeSMauro Carvalho Chehab	  See Documentation/admin-guide/mm/memory-hotplug.rst for more information.
1630a0842b70SToshi Kani	  If you are unsure how to answer this question, answer N.
1631506f1d07SSam Ravnborg
16323b16651fSTejun Heoconfig ARCH_PROC_KCORE_TEXT
16333b16651fSTejun Heo	def_bool y
16343b16651fSTejun Heo	depends on X86_64 && PROC_KCORE
16353b16651fSTejun Heo
1636a29815a3SAvi Kivityconfig ILLEGAL_POINTER_VALUE
1637a29815a3SAvi Kivity	hex
1638a29815a3SAvi Kivity	default 0 if X86_32
1639a29815a3SAvi Kivity	default 0xdead000000000000 if X86_64
1640a29815a3SAvi Kivity
16417a67832cSDan Williamsconfig X86_PMEM_LEGACY_DEVICE
16427a67832cSDan Williams	bool
16437a67832cSDan Williams
1644ec776ef6SChristoph Hellwigconfig X86_PMEM_LEGACY
16457a67832cSDan Williams	tristate "Support non-standard NVDIMMs and ADR protected memory"
16469f53f9faSDan Williams	depends on PHYS_ADDR_T_64BIT
16479f53f9faSDan Williams	depends on BLK_DEV
16487a67832cSDan Williams	select X86_PMEM_LEGACY_DEVICE
16497b27a862SDan Williams	select NUMA_KEEP_MEMINFO if NUMA
16509f53f9faSDan Williams	select LIBNVDIMM
1651ec776ef6SChristoph Hellwig	help
1652ec776ef6SChristoph Hellwig	  Treat memory marked using the non-standard e820 type of 12 as used
1653ec776ef6SChristoph Hellwig	  by the Intel Sandy Bridge-EP reference BIOS as protected memory.
1654ec776ef6SChristoph Hellwig	  The kernel will offer these regions to the 'pmem' driver so
1655ec776ef6SChristoph Hellwig	  they can be used for persistent storage.
1656ec776ef6SChristoph Hellwig
1657ec776ef6SChristoph Hellwig	  Say Y if unsure.
1658ec776ef6SChristoph Hellwig
1659506f1d07SSam Ravnborgconfig HIGHPTE
1660506f1d07SSam Ravnborg	bool "Allocate 3rd-level pagetables from highmem"
16616fc108a0SJan Beulich	depends on HIGHMEM
1662a7f7f624SMasahiro Yamada	help
1663506f1d07SSam Ravnborg	  The VM uses one page table entry for each page of physical memory.
1664506f1d07SSam Ravnborg	  For systems with a lot of RAM, this can be wasteful of precious
1665506f1d07SSam Ravnborg	  low memory.  Setting this option will put user-space page table
1666506f1d07SSam Ravnborg	  entries in high memory.
1667506f1d07SSam Ravnborg
16689f077871SJeremy Fitzhardingeconfig X86_CHECK_BIOS_CORRUPTION
16699f077871SJeremy Fitzhardinge	bool "Check for low memory corruption"
1670a7f7f624SMasahiro Yamada	help
16719f077871SJeremy Fitzhardinge	  Periodically check for memory corruption in low memory, which
16729f077871SJeremy Fitzhardinge	  is suspected to be caused by BIOS.  Even when enabled in the
16739f077871SJeremy Fitzhardinge	  configuration, it is disabled at runtime.  Enable it by
16749f077871SJeremy Fitzhardinge	  setting "memory_corruption_check=1" on the kernel command
16759f077871SJeremy Fitzhardinge	  line.  By default it scans the low 64k of memory every 60
16769f077871SJeremy Fitzhardinge	  seconds; see the memory_corruption_check_size and
16779f077871SJeremy Fitzhardinge	  memory_corruption_check_period parameters in
16788c27ceffSMauro Carvalho Chehab	  Documentation/admin-guide/kernel-parameters.rst to adjust this.
16799f077871SJeremy Fitzhardinge
16809f077871SJeremy Fitzhardinge	  When enabled with the default parameters, this option has
16819f077871SJeremy Fitzhardinge	  almost no overhead, as it reserves a relatively small amount
16829f077871SJeremy Fitzhardinge	  of memory and scans it infrequently.  It both detects corruption
16839f077871SJeremy Fitzhardinge	  and prevents it from affecting the running system.
16849f077871SJeremy Fitzhardinge
16859f077871SJeremy Fitzhardinge	  It is, however, intended as a diagnostic tool; if repeatable
16869f077871SJeremy Fitzhardinge	  BIOS-originated corruption always affects the same memory,
16879f077871SJeremy Fitzhardinge	  you can use memmap= to prevent the kernel from using that
16889f077871SJeremy Fitzhardinge	  memory.
16899f077871SJeremy Fitzhardinge
1690c885df50SJeremy Fitzhardingeconfig X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK
1691c885df50SJeremy Fitzhardinge	bool "Set the default setting of memory_corruption_check"
1692c885df50SJeremy Fitzhardinge	depends on X86_CHECK_BIOS_CORRUPTION
1693c885df50SJeremy Fitzhardinge	default y
1694a7f7f624SMasahiro Yamada	help
1695c885df50SJeremy Fitzhardinge	  Set whether the default state of memory_corruption_check is
1696c885df50SJeremy Fitzhardinge	  on or off.
1697c885df50SJeremy Fitzhardinge
16989ea77bdbSH. Peter Anvinconfig X86_RESERVE_LOW
1699d0cd7425SH. Peter Anvin	int "Amount of low memory, in kilobytes, to reserve for the BIOS"
1700d0cd7425SH. Peter Anvin	default 64
1701d0cd7425SH. Peter Anvin	range 4 640
1702a7f7f624SMasahiro Yamada	help
1703d0cd7425SH. Peter Anvin	  Specify the amount of low memory to reserve for the BIOS.
1704fc381519SIngo Molnar
1705d0cd7425SH. Peter Anvin	  The first page contains BIOS data structures that the kernel
1706d0cd7425SH. Peter Anvin	  must not use, so that page must always be reserved.
1707fc381519SIngo Molnar
1708d0cd7425SH. Peter Anvin	  By default we reserve the first 64K of physical RAM, as a
1709d0cd7425SH. Peter Anvin	  number of BIOSes are known to corrupt that memory range
1710d0cd7425SH. Peter Anvin	  during events such as suspend/resume or monitor cable
1711d0cd7425SH. Peter Anvin	  insertion, so it must not be used by the kernel.
1712fc381519SIngo Molnar
1713d0cd7425SH. Peter Anvin	  You can set this to 4 if you are absolutely sure that you
1714d0cd7425SH. Peter Anvin	  trust the BIOS to get all its memory reservations and usages
1715d0cd7425SH. Peter Anvin	  right.  If you know your BIOS have problems beyond the
1716d0cd7425SH. Peter Anvin	  default 64K area, you can set this to 640 to avoid using the
1717d0cd7425SH. Peter Anvin	  entire low memory range.
1718d0cd7425SH. Peter Anvin
1719d0cd7425SH. Peter Anvin	  If you have doubts about the BIOS (e.g. suspend/resume does
1720d0cd7425SH. Peter Anvin	  not work or there's kernel crashes after certain hardware
1721d0cd7425SH. Peter Anvin	  hotplug events) then you might want to enable
1722d0cd7425SH. Peter Anvin	  X86_CHECK_BIOS_CORRUPTION=y to allow the kernel to check
1723d0cd7425SH. Peter Anvin	  typical corruption patterns.
1724d0cd7425SH. Peter Anvin
1725d0cd7425SH. Peter Anvin	  Leave this to the default value of 64 if you are unsure.
1726fc381519SIngo Molnar
1727506f1d07SSam Ravnborgconfig MATH_EMULATION
1728506f1d07SSam Ravnborg	bool
1729a5b9e5a2SAndy Lutomirski	depends on MODIFY_LDT_SYSCALL
173087d6021bSArnd Bergmann	prompt "Math emulation" if X86_32 && (M486SX || MELAN)
1731a7f7f624SMasahiro Yamada	help
1732506f1d07SSam Ravnborg	  Linux can emulate a math coprocessor (used for floating point
1733506f1d07SSam Ravnborg	  operations) if you don't have one. 486DX and Pentium processors have
1734506f1d07SSam Ravnborg	  a math coprocessor built in, 486SX and 386 do not, unless you added
1735506f1d07SSam Ravnborg	  a 487DX or 387, respectively. (The messages during boot time can
1736506f1d07SSam Ravnborg	  give you some hints here ["man dmesg"].) Everyone needs either a
1737506f1d07SSam Ravnborg	  coprocessor or this emulation.
1738506f1d07SSam Ravnborg
1739506f1d07SSam Ravnborg	  If you don't have a math coprocessor, you need to say Y here; if you
1740506f1d07SSam Ravnborg	  say Y here even though you have a coprocessor, the coprocessor will
1741506f1d07SSam Ravnborg	  be used nevertheless. (This behavior can be changed with the kernel
1742506f1d07SSam Ravnborg	  command line option "no387", which comes handy if your coprocessor
1743506f1d07SSam Ravnborg	  is broken. Try "man bootparam" or see the documentation of your boot
1744506f1d07SSam Ravnborg	  loader (lilo or loadlin) about how to pass options to the kernel at
1745506f1d07SSam Ravnborg	  boot time.) This means that it is a good idea to say Y here if you
1746506f1d07SSam Ravnborg	  intend to use this kernel on different machines.
1747506f1d07SSam Ravnborg
1748506f1d07SSam Ravnborg	  More information about the internals of the Linux math coprocessor
1749506f1d07SSam Ravnborg	  emulation can be found in <file:arch/x86/math-emu/README>.
1750506f1d07SSam Ravnborg
1751506f1d07SSam Ravnborg	  If you are not sure, say Y; apart from resulting in a 66 KB bigger
1752506f1d07SSam Ravnborg	  kernel, it won't hurt.
1753506f1d07SSam Ravnborg
1754506f1d07SSam Ravnborgconfig MTRR
17556fc108a0SJan Beulich	def_bool y
17566a108a14SDavid Rientjes	prompt "MTRR (Memory Type Range Register) support" if EXPERT
1757a7f7f624SMasahiro Yamada	help
1758506f1d07SSam Ravnborg	  On Intel P6 family processors (Pentium Pro, Pentium II and later)
1759506f1d07SSam Ravnborg	  the Memory Type Range Registers (MTRRs) may be used to control
1760506f1d07SSam Ravnborg	  processor access to memory ranges. This is most useful if you have
1761506f1d07SSam Ravnborg	  a video (VGA) card on a PCI or AGP bus. Enabling write-combining
1762506f1d07SSam Ravnborg	  allows bus write transfers to be combined into a larger transfer
1763506f1d07SSam Ravnborg	  before bursting over the PCI/AGP bus. This can increase performance
1764506f1d07SSam Ravnborg	  of image write operations 2.5 times or more. Saying Y here creates a
1765506f1d07SSam Ravnborg	  /proc/mtrr file which may be used to manipulate your processor's
1766506f1d07SSam Ravnborg	  MTRRs. Typically the X server should use this.
1767506f1d07SSam Ravnborg
1768506f1d07SSam Ravnborg	  This code has a reasonably generic interface so that similar
1769506f1d07SSam Ravnborg	  control registers on other processors can be easily supported
1770506f1d07SSam Ravnborg	  as well:
1771506f1d07SSam Ravnborg
1772506f1d07SSam Ravnborg	  The Cyrix 6x86, 6x86MX and M II processors have Address Range
1773506f1d07SSam Ravnborg	  Registers (ARRs) which provide a similar functionality to MTRRs. For
1774506f1d07SSam Ravnborg	  these, the ARRs are used to emulate the MTRRs.
1775506f1d07SSam Ravnborg	  The AMD K6-2 (stepping 8 and above) and K6-3 processors have two
1776506f1d07SSam Ravnborg	  MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing
1777506f1d07SSam Ravnborg	  write-combining. All of these processors are supported by this code
1778506f1d07SSam Ravnborg	  and it makes sense to say Y here if you have one of them.
1779506f1d07SSam Ravnborg
1780506f1d07SSam Ravnborg	  Saying Y here also fixes a problem with buggy SMP BIOSes which only
1781506f1d07SSam Ravnborg	  set the MTRRs for the boot CPU and not for the secondary CPUs. This
1782506f1d07SSam Ravnborg	  can lead to all sorts of problems, so it's good to say Y here.
1783506f1d07SSam Ravnborg
1784506f1d07SSam Ravnborg	  You can safely say Y even if your machine doesn't have MTRRs, you'll
1785506f1d07SSam Ravnborg	  just add about 9 KB to your kernel.
1786506f1d07SSam Ravnborg
1787cb1aaebeSMauro Carvalho Chehab	  See <file:Documentation/x86/mtrr.rst> for more information.
1788506f1d07SSam Ravnborg
178995ffa243SYinghai Luconfig MTRR_SANITIZER
17902ffb3501SYinghai Lu	def_bool y
179195ffa243SYinghai Lu	prompt "MTRR cleanup support"
179295ffa243SYinghai Lu	depends on MTRR
1793a7f7f624SMasahiro Yamada	help
1794aba3728cSThomas Gleixner	  Convert MTRR layout from continuous to discrete, so X drivers can
1795aba3728cSThomas Gleixner	  add writeback entries.
179695ffa243SYinghai Lu
1797aba3728cSThomas Gleixner	  Can be disabled with disable_mtrr_cleanup on the kernel command line.
1798692105b8SMatt LaPlante	  The largest mtrr entry size for a continuous block can be set with
1799aba3728cSThomas Gleixner	  mtrr_chunk_size.
180095ffa243SYinghai Lu
18012ffb3501SYinghai Lu	  If unsure, say Y.
180295ffa243SYinghai Lu
180395ffa243SYinghai Luconfig MTRR_SANITIZER_ENABLE_DEFAULT
1804f5098d62SYinghai Lu	int "MTRR cleanup enable value (0-1)"
1805f5098d62SYinghai Lu	range 0 1
1806f5098d62SYinghai Lu	default "0"
180795ffa243SYinghai Lu	depends on MTRR_SANITIZER
1808a7f7f624SMasahiro Yamada	help
1809f5098d62SYinghai Lu	  Enable mtrr cleanup default value
181095ffa243SYinghai Lu
181112031a62SYinghai Luconfig MTRR_SANITIZER_SPARE_REG_NR_DEFAULT
181212031a62SYinghai Lu	int "MTRR cleanup spare reg num (0-7)"
181312031a62SYinghai Lu	range 0 7
181412031a62SYinghai Lu	default "1"
181512031a62SYinghai Lu	depends on MTRR_SANITIZER
1816a7f7f624SMasahiro Yamada	help
181712031a62SYinghai Lu	  mtrr cleanup spare entries default, it can be changed via
1818aba3728cSThomas Gleixner	  mtrr_spare_reg_nr=N on the kernel command line.
181912031a62SYinghai Lu
18202e5d9c85Svenkatesh.pallipadi@intel.comconfig X86_PAT
18216fc108a0SJan Beulich	def_bool y
18226a108a14SDavid Rientjes	prompt "x86 PAT support" if EXPERT
18232a8a2719SIngo Molnar	depends on MTRR
1824a7f7f624SMasahiro Yamada	help
18252e5d9c85Svenkatesh.pallipadi@intel.com	  Use PAT attributes to setup page level cache control.
1826042b78e4SVenki Pallipadi
18272e5d9c85Svenkatesh.pallipadi@intel.com	  PATs are the modern equivalents of MTRRs and are much more
18282e5d9c85Svenkatesh.pallipadi@intel.com	  flexible than MTRRs.
18292e5d9c85Svenkatesh.pallipadi@intel.com
18302e5d9c85Svenkatesh.pallipadi@intel.com	  Say N here if you see bootup problems (boot crash, boot hang,
1831042b78e4SVenki Pallipadi	  spontaneous reboots) or a non-working video driver.
18322e5d9c85Svenkatesh.pallipadi@intel.com
18332e5d9c85Svenkatesh.pallipadi@intel.com	  If unsure, say Y.
18342e5d9c85Svenkatesh.pallipadi@intel.com
183546cf98cdSVenkatesh Pallipadiconfig ARCH_USES_PG_UNCACHED
183646cf98cdSVenkatesh Pallipadi	def_bool y
183746cf98cdSVenkatesh Pallipadi	depends on X86_PAT
183846cf98cdSVenkatesh Pallipadi
1839628c6246SH. Peter Anvinconfig ARCH_RANDOM
1840628c6246SH. Peter Anvin	def_bool y
1841628c6246SH. Peter Anvin	prompt "x86 architectural random number generator" if EXPERT
1842a7f7f624SMasahiro Yamada	help
1843628c6246SH. Peter Anvin	  Enable the x86 architectural RDRAND instruction
1844628c6246SH. Peter Anvin	  (Intel Bull Mountain technology) to generate random numbers.
1845628c6246SH. Peter Anvin	  If supported, this is a high bandwidth, cryptographically
1846628c6246SH. Peter Anvin	  secure hardware random number generator.
1847628c6246SH. Peter Anvin
184851ae4a2dSH. Peter Anvinconfig X86_SMAP
184951ae4a2dSH. Peter Anvin	def_bool y
185051ae4a2dSH. Peter Anvin	prompt "Supervisor Mode Access Prevention" if EXPERT
1851a7f7f624SMasahiro Yamada	help
185251ae4a2dSH. Peter Anvin	  Supervisor Mode Access Prevention (SMAP) is a security
185351ae4a2dSH. Peter Anvin	  feature in newer Intel processors.  There is a small
185451ae4a2dSH. Peter Anvin	  performance cost if this enabled and turned on; there is
185551ae4a2dSH. Peter Anvin	  also a small increase in the kernel size if this is enabled.
185651ae4a2dSH. Peter Anvin
185751ae4a2dSH. Peter Anvin	  If unsure, say Y.
185851ae4a2dSH. Peter Anvin
1859b971880fSBabu Mogerconfig X86_UMIP
1860796ebc81SRicardo Neri	def_bool y
1861b971880fSBabu Moger	prompt "User Mode Instruction Prevention" if EXPERT
1862a7f7f624SMasahiro Yamada	help
1863b971880fSBabu Moger	  User Mode Instruction Prevention (UMIP) is a security feature in
1864b971880fSBabu Moger	  some x86 processors. If enabled, a general protection fault is
1865b971880fSBabu Moger	  issued if the SGDT, SLDT, SIDT, SMSW or STR instructions are
1866b971880fSBabu Moger	  executed in user mode. These instructions unnecessarily expose
1867b971880fSBabu Moger	  information about the hardware state.
1868796ebc81SRicardo Neri
1869796ebc81SRicardo Neri	  The vast majority of applications do not use these instructions.
1870796ebc81SRicardo Neri	  For the very few that do, software emulation is provided in
1871796ebc81SRicardo Neri	  specific cases in protected and virtual-8086 modes. Emulated
1872796ebc81SRicardo Neri	  results are dummy.
1873aa35f896SRicardo Neri
187435e97790SDave Hansenconfig X86_INTEL_MEMORY_PROTECTION_KEYS
187538f3e775SBabu Moger	prompt "Memory Protection Keys"
187635e97790SDave Hansen	def_bool y
1877284244a9SDave Hansen	# Note: only available in 64-bit mode
187838f3e775SBabu Moger	depends on X86_64 && (CPU_SUP_INTEL || CPU_SUP_AMD)
187952c8e601SIngo Molnar	select ARCH_USES_HIGH_VMA_FLAGS
188052c8e601SIngo Molnar	select ARCH_HAS_PKEYS
1881a7f7f624SMasahiro Yamada	help
1882284244a9SDave Hansen	  Memory Protection Keys provides a mechanism for enforcing
1883284244a9SDave Hansen	  page-based protections, but without requiring modification of the
1884284244a9SDave Hansen	  page tables when an application changes protection domains.
1885284244a9SDave Hansen
18861eecbcdcSMauro Carvalho Chehab	  For details, see Documentation/core-api/protection-keys.rst
1887284244a9SDave Hansen
1888284244a9SDave Hansen	  If unsure, say y.
188935e97790SDave Hansen
1890db616173SMichal Hockochoice
1891db616173SMichal Hocko	prompt "TSX enable mode"
1892db616173SMichal Hocko	depends on CPU_SUP_INTEL
1893db616173SMichal Hocko	default X86_INTEL_TSX_MODE_OFF
1894db616173SMichal Hocko	help
1895db616173SMichal Hocko	  Intel's TSX (Transactional Synchronization Extensions) feature
1896db616173SMichal Hocko	  allows to optimize locking protocols through lock elision which
1897db616173SMichal Hocko	  can lead to a noticeable performance boost.
1898db616173SMichal Hocko
1899db616173SMichal Hocko	  On the other hand it has been shown that TSX can be exploited
1900db616173SMichal Hocko	  to form side channel attacks (e.g. TAA) and chances are there
1901db616173SMichal Hocko	  will be more of those attacks discovered in the future.
1902db616173SMichal Hocko
1903db616173SMichal Hocko	  Therefore TSX is not enabled by default (aka tsx=off). An admin
1904db616173SMichal Hocko	  might override this decision by tsx=on the command line parameter.
1905db616173SMichal Hocko	  Even with TSX enabled, the kernel will attempt to enable the best
1906db616173SMichal Hocko	  possible TAA mitigation setting depending on the microcode available
1907db616173SMichal Hocko	  for the particular machine.
1908db616173SMichal Hocko
1909db616173SMichal Hocko	  This option allows to set the default tsx mode between tsx=on, =off
1910db616173SMichal Hocko	  and =auto. See Documentation/admin-guide/kernel-parameters.txt for more
1911db616173SMichal Hocko	  details.
1912db616173SMichal Hocko
1913db616173SMichal Hocko	  Say off if not sure, auto if TSX is in use but it should be used on safe
1914db616173SMichal Hocko	  platforms or on if TSX is in use and the security aspect of tsx is not
1915db616173SMichal Hocko	  relevant.
1916db616173SMichal Hocko
1917db616173SMichal Hockoconfig X86_INTEL_TSX_MODE_OFF
1918db616173SMichal Hocko	bool "off"
1919db616173SMichal Hocko	help
1920db616173SMichal Hocko	  TSX is disabled if possible - equals to tsx=off command line parameter.
1921db616173SMichal Hocko
1922db616173SMichal Hockoconfig X86_INTEL_TSX_MODE_ON
1923db616173SMichal Hocko	bool "on"
1924db616173SMichal Hocko	help
1925db616173SMichal Hocko	  TSX is always enabled on TSX capable HW - equals the tsx=on command
1926db616173SMichal Hocko	  line parameter.
1927db616173SMichal Hocko
1928db616173SMichal Hockoconfig X86_INTEL_TSX_MODE_AUTO
1929db616173SMichal Hocko	bool "auto"
1930db616173SMichal Hocko	help
1931db616173SMichal Hocko	  TSX is enabled on TSX capable HW that is believed to be safe against
1932db616173SMichal Hocko	  side channel attacks- equals the tsx=auto command line parameter.
1933db616173SMichal Hockoendchoice
1934db616173SMichal Hocko
1935506f1d07SSam Ravnborgconfig EFI
19369ba16087SJan Beulich	bool "EFI runtime service support"
19375b83683fSHuang, Ying	depends on ACPI
1938f6ce5002SSergey Vlasov	select UCS2_STRING
1939022ee6c5SArd Biesheuvel	select EFI_RUNTIME_WRAPPERS
1940a7f7f624SMasahiro Yamada	help
19418b2cb7a8SHuang, Ying	  This enables the kernel to use EFI runtime services that are
1942506f1d07SSam Ravnborg	  available (such as the EFI variable services).
1943506f1d07SSam Ravnborg
19448b2cb7a8SHuang, Ying	  This option is only useful on systems that have EFI firmware.
19458b2cb7a8SHuang, Ying	  In addition, you should use the latest ELILO loader available
19468b2cb7a8SHuang, Ying	  at <http://elilo.sourceforge.net> in order to take advantage
19478b2cb7a8SHuang, Ying	  of EFI runtime services. However, even with this option, the
19488b2cb7a8SHuang, Ying	  resultant kernel should continue to boot on existing non-EFI
19498b2cb7a8SHuang, Ying	  platforms.
1950506f1d07SSam Ravnborg
1951291f3632SMatt Flemingconfig EFI_STUB
1952291f3632SMatt Fleming	bool "EFI stub support"
1953b16d8c23SMatt Fleming	depends on EFI && !X86_USE_3DNOW
19548f24f8c2SArd Biesheuvel	depends on $(cc-option,-mabi=ms) || X86_32
19557b2a583aSMatt Fleming	select RELOCATABLE
1956a7f7f624SMasahiro Yamada	help
1957291f3632SMatt Fleming	  This kernel feature allows a bzImage to be loaded directly
1958291f3632SMatt Fleming	  by EFI firmware without the use of a bootloader.
1959291f3632SMatt Fleming
19604f4cfa6cSMauro Carvalho Chehab	  See Documentation/admin-guide/efi-stub.rst for more information.
19610c759662SMatt Fleming
19627d453eeeSMatt Flemingconfig EFI_MIXED
19637d453eeeSMatt Fleming	bool "EFI mixed-mode support"
19647d453eeeSMatt Fleming	depends on EFI_STUB && X86_64
1965a7f7f624SMasahiro Yamada	help
19667d453eeeSMatt Fleming	   Enabling this feature allows a 64-bit kernel to be booted
19677d453eeeSMatt Fleming	   on a 32-bit firmware, provided that your CPU supports 64-bit
19687d453eeeSMatt Fleming	   mode.
19697d453eeeSMatt Fleming
19707d453eeeSMatt Fleming	   Note that it is not possible to boot a mixed-mode enabled
19717d453eeeSMatt Fleming	   kernel via the EFI boot stub - a bootloader that supports
19727d453eeeSMatt Fleming	   the EFI handover protocol must be used.
19737d453eeeSMatt Fleming
19747d453eeeSMatt Fleming	   If unsure, say N.
19757d453eeeSMatt Fleming
19768636a1f9SMasahiro Yamadasource "kernel/Kconfig.hz"
1977506f1d07SSam Ravnborg
1978506f1d07SSam Ravnborgconfig KEXEC
1979506f1d07SSam Ravnborg	bool "kexec system call"
19802965faa5SDave Young	select KEXEC_CORE
1981a7f7f624SMasahiro Yamada	help
1982506f1d07SSam Ravnborg	  kexec is a system call that implements the ability to shutdown your
1983506f1d07SSam Ravnborg	  current kernel, and to start another kernel.  It is like a reboot
1984506f1d07SSam Ravnborg	  but it is independent of the system firmware.   And like a reboot
1985506f1d07SSam Ravnborg	  you can start any kernel with it, not just Linux.
1986506f1d07SSam Ravnborg
1987506f1d07SSam Ravnborg	  The name comes from the similarity to the exec system call.
1988506f1d07SSam Ravnborg
1989506f1d07SSam Ravnborg	  It is an ongoing process to be certain the hardware in a machine
1990506f1d07SSam Ravnborg	  is properly shutdown, so do not be surprised if this code does not
1991bf220695SGeert Uytterhoeven	  initially work for you.  As of this writing the exact hardware
1992bf220695SGeert Uytterhoeven	  interface is strongly in flux, so no good recommendation can be
1993bf220695SGeert Uytterhoeven	  made.
1994506f1d07SSam Ravnborg
199574ca317cSVivek Goyalconfig KEXEC_FILE
199674ca317cSVivek Goyal	bool "kexec file based system call"
19972965faa5SDave Young	select KEXEC_CORE
199874ca317cSVivek Goyal	select BUILD_BIN2C
199974ca317cSVivek Goyal	depends on X86_64
200074ca317cSVivek Goyal	depends on CRYPTO=y
200174ca317cSVivek Goyal	depends on CRYPTO_SHA256=y
2002a7f7f624SMasahiro Yamada	help
200374ca317cSVivek Goyal	  This is new version of kexec system call. This system call is
200474ca317cSVivek Goyal	  file based and takes file descriptors as system call argument
200574ca317cSVivek Goyal	  for kernel and initramfs as opposed to list of segments as
200674ca317cSVivek Goyal	  accepted by previous system call.
200774ca317cSVivek Goyal
2008b799a09fSAKASHI Takahiroconfig ARCH_HAS_KEXEC_PURGATORY
2009b799a09fSAKASHI Takahiro	def_bool KEXEC_FILE
2010b799a09fSAKASHI Takahiro
201199d5cadfSJiri Bohacconfig KEXEC_SIG
20128e7d8381SVivek Goyal	bool "Verify kernel signature during kexec_file_load() syscall"
201374ca317cSVivek Goyal	depends on KEXEC_FILE
2014a7f7f624SMasahiro Yamada	help
201599d5cadfSJiri Bohac
201699d5cadfSJiri Bohac	  This option makes the kexec_file_load() syscall check for a valid
201799d5cadfSJiri Bohac	  signature of the kernel image.  The image can still be loaded without
201899d5cadfSJiri Bohac	  a valid signature unless you also enable KEXEC_SIG_FORCE, though if
201999d5cadfSJiri Bohac	  there's a signature that we can check, then it must be valid.
202099d5cadfSJiri Bohac
202199d5cadfSJiri Bohac	  In addition to this option, you need to enable signature
202299d5cadfSJiri Bohac	  verification for the corresponding kernel image type being
202399d5cadfSJiri Bohac	  loaded in order for this to work.
202499d5cadfSJiri Bohac
202599d5cadfSJiri Bohacconfig KEXEC_SIG_FORCE
202699d5cadfSJiri Bohac	bool "Require a valid signature in kexec_file_load() syscall"
202799d5cadfSJiri Bohac	depends on KEXEC_SIG
2028a7f7f624SMasahiro Yamada	help
20298e7d8381SVivek Goyal	  This option makes kernel signature verification mandatory for
2030d8eb8940SBorislav Petkov	  the kexec_file_load() syscall.
20318e7d8381SVivek Goyal
20328e7d8381SVivek Goyalconfig KEXEC_BZIMAGE_VERIFY_SIG
20338e7d8381SVivek Goyal	bool "Enable bzImage signature verification support"
203499d5cadfSJiri Bohac	depends on KEXEC_SIG
20358e7d8381SVivek Goyal	depends on SIGNED_PE_FILE_VERIFICATION
20368e7d8381SVivek Goyal	select SYSTEM_TRUSTED_KEYRING
2037a7f7f624SMasahiro Yamada	help
20388e7d8381SVivek Goyal	  Enable bzImage signature verification support.
20398e7d8381SVivek Goyal
2040506f1d07SSam Ravnborgconfig CRASH_DUMP
204104b69447SPavel Machek	bool "kernel crash dumps"
2042506f1d07SSam Ravnborg	depends on X86_64 || (X86_32 && HIGHMEM)
2043a7f7f624SMasahiro Yamada	help
2044506f1d07SSam Ravnborg	  Generate crash dump after being started by kexec.
2045506f1d07SSam Ravnborg	  This should be normally only set in special crash dump kernels
2046506f1d07SSam Ravnborg	  which are loaded in the main kernel with kexec-tools into
2047506f1d07SSam Ravnborg	  a specially reserved region and then later executed after
2048506f1d07SSam Ravnborg	  a crash by kdump/kexec. The crash dump kernel must be compiled
2049506f1d07SSam Ravnborg	  to a memory address not used by the main kernel or BIOS using
2050506f1d07SSam Ravnborg	  PHYSICAL_START, or it must be built as a relocatable image
2051506f1d07SSam Ravnborg	  (CONFIG_RELOCATABLE=y).
2052330d4810SMauro Carvalho Chehab	  For more details see Documentation/admin-guide/kdump/kdump.rst
2053506f1d07SSam Ravnborg
20543ab83521SHuang Yingconfig KEXEC_JUMP
20556ea30386SKees Cook	bool "kexec jump"
2056fee7b0d8SHuang Ying	depends on KEXEC && HIBERNATION
2057a7f7f624SMasahiro Yamada	help
205889081d17SHuang Ying	  Jump between original kernel and kexeced kernel and invoke
205989081d17SHuang Ying	  code in physical address mode via KEXEC
20603ab83521SHuang Ying
2061506f1d07SSam Ravnborgconfig PHYSICAL_START
20626a108a14SDavid Rientjes	hex "Physical address where the kernel is loaded" if (EXPERT || CRASH_DUMP)
2063ceefccc9SH. Peter Anvin	default "0x1000000"
2064a7f7f624SMasahiro Yamada	help
2065506f1d07SSam Ravnborg	  This gives the physical address where the kernel is loaded.
2066506f1d07SSam Ravnborg
2067506f1d07SSam Ravnborg	  If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then
2068506f1d07SSam Ravnborg	  bzImage will decompress itself to above physical address and
2069506f1d07SSam Ravnborg	  run from there. Otherwise, bzImage will run from the address where
2070506f1d07SSam Ravnborg	  it has been loaded by the boot loader and will ignore above physical
2071506f1d07SSam Ravnborg	  address.
2072506f1d07SSam Ravnborg
2073506f1d07SSam Ravnborg	  In normal kdump cases one does not have to set/change this option
2074506f1d07SSam Ravnborg	  as now bzImage can be compiled as a completely relocatable image
2075506f1d07SSam Ravnborg	  (CONFIG_RELOCATABLE=y) and be used to load and run from a different
2076506f1d07SSam Ravnborg	  address. This option is mainly useful for the folks who don't want
2077506f1d07SSam Ravnborg	  to use a bzImage for capturing the crash dump and want to use a
2078506f1d07SSam Ravnborg	  vmlinux instead. vmlinux is not relocatable hence a kernel needs
2079506f1d07SSam Ravnborg	  to be specifically compiled to run from a specific memory area
2080506f1d07SSam Ravnborg	  (normally a reserved region) and this option comes handy.
2081506f1d07SSam Ravnborg
2082ceefccc9SH. Peter Anvin	  So if you are using bzImage for capturing the crash dump,
2083ceefccc9SH. Peter Anvin	  leave the value here unchanged to 0x1000000 and set
2084ceefccc9SH. Peter Anvin	  CONFIG_RELOCATABLE=y.  Otherwise if you plan to use vmlinux
2085ceefccc9SH. Peter Anvin	  for capturing the crash dump change this value to start of
2086ceefccc9SH. Peter Anvin	  the reserved region.  In other words, it can be set based on
2087ceefccc9SH. Peter Anvin	  the "X" value as specified in the "crashkernel=YM@XM"
2088ceefccc9SH. Peter Anvin	  command line boot parameter passed to the panic-ed
2089330d4810SMauro Carvalho Chehab	  kernel. Please take a look at Documentation/admin-guide/kdump/kdump.rst
2090ceefccc9SH. Peter Anvin	  for more details about crash dumps.
2091506f1d07SSam Ravnborg
2092506f1d07SSam Ravnborg	  Usage of bzImage for capturing the crash dump is recommended as
2093506f1d07SSam Ravnborg	  one does not have to build two kernels. Same kernel can be used
2094506f1d07SSam Ravnborg	  as production kernel and capture kernel. Above option should have
2095506f1d07SSam Ravnborg	  gone away after relocatable bzImage support is introduced. But it
2096506f1d07SSam Ravnborg	  is present because there are users out there who continue to use
2097506f1d07SSam Ravnborg	  vmlinux for dump capture. This option should go away down the
2098506f1d07SSam Ravnborg	  line.
2099506f1d07SSam Ravnborg
2100506f1d07SSam Ravnborg	  Don't change this unless you know what you are doing.
2101506f1d07SSam Ravnborg
2102506f1d07SSam Ravnborgconfig RELOCATABLE
210326717808SH. Peter Anvin	bool "Build a relocatable kernel"
210426717808SH. Peter Anvin	default y
2105a7f7f624SMasahiro Yamada	help
2106506f1d07SSam Ravnborg	  This builds a kernel image that retains relocation information
2107506f1d07SSam Ravnborg	  so it can be loaded someplace besides the default 1MB.
2108506f1d07SSam Ravnborg	  The relocations tend to make the kernel binary about 10% larger,
2109506f1d07SSam Ravnborg	  but are discarded at runtime.
2110506f1d07SSam Ravnborg
2111506f1d07SSam Ravnborg	  One use is for the kexec on panic case where the recovery kernel
2112506f1d07SSam Ravnborg	  must live at a different physical address than the primary
2113506f1d07SSam Ravnborg	  kernel.
2114506f1d07SSam Ravnborg
2115506f1d07SSam Ravnborg	  Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address
2116506f1d07SSam Ravnborg	  it has been loaded at and the compile time physical address
21178ab3820fSKees Cook	  (CONFIG_PHYSICAL_START) is used as the minimum location.
2118506f1d07SSam Ravnborg
21198ab3820fSKees Cookconfig RANDOMIZE_BASE
2120e8581e3dSBaoquan He	bool "Randomize the address of the kernel image (KASLR)"
21218ab3820fSKees Cook	depends on RELOCATABLE
21226807c846SIngo Molnar	default y
2123a7f7f624SMasahiro Yamada	help
2124e8581e3dSBaoquan He	  In support of Kernel Address Space Layout Randomization (KASLR),
2125e8581e3dSBaoquan He	  this randomizes the physical address at which the kernel image
2126e8581e3dSBaoquan He	  is decompressed and the virtual address where the kernel
2127e8581e3dSBaoquan He	  image is mapped, as a security feature that deters exploit
2128e8581e3dSBaoquan He	  attempts relying on knowledge of the location of kernel
2129e8581e3dSBaoquan He	  code internals.
2130e8581e3dSBaoquan He
2131ed9f007eSKees Cook	  On 64-bit, the kernel physical and virtual addresses are
2132ed9f007eSKees Cook	  randomized separately. The physical address will be anywhere
2133ed9f007eSKees Cook	  between 16MB and the top of physical memory (up to 64TB). The
2134ed9f007eSKees Cook	  virtual address will be randomized from 16MB up to 1GB (9 bits
2135ed9f007eSKees Cook	  of entropy). Note that this also reduces the memory space
2136ed9f007eSKees Cook	  available to kernel modules from 1.5GB to 1GB.
2137ed9f007eSKees Cook
2138ed9f007eSKees Cook	  On 32-bit, the kernel physical and virtual addresses are
2139ed9f007eSKees Cook	  randomized together. They will be randomized from 16MB up to
2140ed9f007eSKees Cook	  512MB (8 bits of entropy).
21418ab3820fSKees Cook
2142a653f356SKees Cook	  Entropy is generated using the RDRAND instruction if it is
2143e8581e3dSBaoquan He	  supported. If RDTSC is supported, its value is mixed into
2144e8581e3dSBaoquan He	  the entropy pool as well. If neither RDRAND nor RDTSC are
2145ed9f007eSKees Cook	  supported, then entropy is read from the i8254 timer. The
2146ed9f007eSKees Cook	  usable entropy is limited by the kernel being built using
2147ed9f007eSKees Cook	  2GB addressing, and that PHYSICAL_ALIGN must be at a
2148ed9f007eSKees Cook	  minimum of 2MB. As a result, only 10 bits of entropy are
2149ed9f007eSKees Cook	  theoretically possible, but the implementations are further
2150ed9f007eSKees Cook	  limited due to memory layouts.
2151e8581e3dSBaoquan He
21526807c846SIngo Molnar	  If unsure, say Y.
2153da2b6fb9SKees Cook
21548ab3820fSKees Cook# Relocation on x86 needs some additional build support
2155845adf72SH. Peter Anvinconfig X86_NEED_RELOCS
2156845adf72SH. Peter Anvin	def_bool y
21578ab3820fSKees Cook	depends on RANDOMIZE_BASE || (X86_32 && RELOCATABLE)
2158845adf72SH. Peter Anvin
2159506f1d07SSam Ravnborgconfig PHYSICAL_ALIGN
2160a0215061SKees Cook	hex "Alignment value to which kernel should be aligned"
21618ab3820fSKees Cook	default "0x200000"
2162a0215061SKees Cook	range 0x2000 0x1000000 if X86_32
2163a0215061SKees Cook	range 0x200000 0x1000000 if X86_64
2164a7f7f624SMasahiro Yamada	help
2165506f1d07SSam Ravnborg	  This value puts the alignment restrictions on physical address
2166506f1d07SSam Ravnborg	  where kernel is loaded and run from. Kernel is compiled for an
2167506f1d07SSam Ravnborg	  address which meets above alignment restriction.
2168506f1d07SSam Ravnborg
2169506f1d07SSam Ravnborg	  If bootloader loads the kernel at a non-aligned address and
2170506f1d07SSam Ravnborg	  CONFIG_RELOCATABLE is set, kernel will move itself to nearest
2171506f1d07SSam Ravnborg	  address aligned to above value and run from there.
2172506f1d07SSam Ravnborg
2173506f1d07SSam Ravnborg	  If bootloader loads the kernel at a non-aligned address and
2174506f1d07SSam Ravnborg	  CONFIG_RELOCATABLE is not set, kernel will ignore the run time
2175506f1d07SSam Ravnborg	  load address and decompress itself to the address it has been
2176506f1d07SSam Ravnborg	  compiled for and run from there. The address for which kernel is
2177506f1d07SSam Ravnborg	  compiled already meets above alignment restrictions. Hence the
2178506f1d07SSam Ravnborg	  end result is that kernel runs from a physical address meeting
2179506f1d07SSam Ravnborg	  above alignment restrictions.
2180506f1d07SSam Ravnborg
2181a0215061SKees Cook	  On 32-bit this value must be a multiple of 0x2000. On 64-bit
2182a0215061SKees Cook	  this value must be a multiple of 0x200000.
2183a0215061SKees Cook
2184506f1d07SSam Ravnborg	  Don't change this unless you know what you are doing.
2185506f1d07SSam Ravnborg
2186eedb92abSKirill A. Shutemovconfig DYNAMIC_MEMORY_LAYOUT
2187eedb92abSKirill A. Shutemov	bool
2188a7f7f624SMasahiro Yamada	help
2189eedb92abSKirill A. Shutemov	  This option makes base addresses of vmalloc and vmemmap as well as
2190eedb92abSKirill A. Shutemov	  __PAGE_OFFSET movable during boot.
2191eedb92abSKirill A. Shutemov
21920483e1faSThomas Garnierconfig RANDOMIZE_MEMORY
21930483e1faSThomas Garnier	bool "Randomize the kernel memory sections"
21940483e1faSThomas Garnier	depends on X86_64
21950483e1faSThomas Garnier	depends on RANDOMIZE_BASE
2196eedb92abSKirill A. Shutemov	select DYNAMIC_MEMORY_LAYOUT
21970483e1faSThomas Garnier	default RANDOMIZE_BASE
2198a7f7f624SMasahiro Yamada	help
21990483e1faSThomas Garnier	   Randomizes the base virtual address of kernel memory sections
22000483e1faSThomas Garnier	   (physical memory mapping, vmalloc & vmemmap). This security feature
22010483e1faSThomas Garnier	   makes exploits relying on predictable memory locations less reliable.
22020483e1faSThomas Garnier
22030483e1faSThomas Garnier	   The order of allocations remains unchanged. Entropy is generated in
22040483e1faSThomas Garnier	   the same way as RANDOMIZE_BASE. Current implementation in the optimal
22050483e1faSThomas Garnier	   configuration have in average 30,000 different possible virtual
22060483e1faSThomas Garnier	   addresses for each memory section.
22070483e1faSThomas Garnier
22086807c846SIngo Molnar	   If unsure, say Y.
22090483e1faSThomas Garnier
221090397a41SThomas Garnierconfig RANDOMIZE_MEMORY_PHYSICAL_PADDING
221190397a41SThomas Garnier	hex "Physical memory mapping padding" if EXPERT
221290397a41SThomas Garnier	depends on RANDOMIZE_MEMORY
221390397a41SThomas Garnier	default "0xa" if MEMORY_HOTPLUG
221490397a41SThomas Garnier	default "0x0"
221590397a41SThomas Garnier	range 0x1 0x40 if MEMORY_HOTPLUG
221690397a41SThomas Garnier	range 0x0 0x40
2217a7f7f624SMasahiro Yamada	help
221890397a41SThomas Garnier	   Define the padding in terabytes added to the existing physical
221990397a41SThomas Garnier	   memory size during kernel memory randomization. It is useful
222090397a41SThomas Garnier	   for memory hotplug support but reduces the entropy available for
222190397a41SThomas Garnier	   address randomization.
222290397a41SThomas Garnier
222390397a41SThomas Garnier	   If unsure, leave at the default value.
222490397a41SThomas Garnier
2225506f1d07SSam Ravnborgconfig HOTPLUG_CPU
2226bebd024eSThomas Gleixner	def_bool y
222740b31360SStephen Rothwell	depends on SMP
2228506f1d07SSam Ravnborg
222980aa1dffSFenghua Yuconfig BOOTPARAM_HOTPLUG_CPU0
223080aa1dffSFenghua Yu	bool "Set default setting of cpu0_hotpluggable"
22312c922cd0SKees Cook	depends on HOTPLUG_CPU
2232a7f7f624SMasahiro Yamada	help
223380aa1dffSFenghua Yu	  Set whether default state of cpu0_hotpluggable is on or off.
223480aa1dffSFenghua Yu
223580aa1dffSFenghua Yu	  Say Y here to enable CPU0 hotplug by default. If this switch
223680aa1dffSFenghua Yu	  is turned on, there is no need to give cpu0_hotplug kernel
223780aa1dffSFenghua Yu	  parameter and the CPU0 hotplug feature is enabled by default.
223880aa1dffSFenghua Yu
223980aa1dffSFenghua Yu	  Please note: there are two known CPU0 dependencies if you want
224080aa1dffSFenghua Yu	  to enable the CPU0 hotplug feature either by this switch or by
224180aa1dffSFenghua Yu	  cpu0_hotplug kernel parameter.
224280aa1dffSFenghua Yu
224380aa1dffSFenghua Yu	  First, resume from hibernate or suspend always starts from CPU0.
224480aa1dffSFenghua Yu	  So hibernate and suspend are prevented if CPU0 is offline.
224580aa1dffSFenghua Yu
224680aa1dffSFenghua Yu	  Second dependency is PIC interrupts always go to CPU0. CPU0 can not
224780aa1dffSFenghua Yu	  offline if any interrupt can not migrate out of CPU0. There may
224880aa1dffSFenghua Yu	  be other CPU0 dependencies.
224980aa1dffSFenghua Yu
225080aa1dffSFenghua Yu	  Please make sure the dependencies are under your control before
225180aa1dffSFenghua Yu	  you enable this feature.
225280aa1dffSFenghua Yu
225380aa1dffSFenghua Yu	  Say N if you don't want to enable CPU0 hotplug feature by default.
225480aa1dffSFenghua Yu	  You still can enable the CPU0 hotplug feature at boot by kernel
225580aa1dffSFenghua Yu	  parameter cpu0_hotplug.
225680aa1dffSFenghua Yu
2257a71c8bc5SFenghua Yuconfig DEBUG_HOTPLUG_CPU0
2258a71c8bc5SFenghua Yu	def_bool n
2259a71c8bc5SFenghua Yu	prompt "Debug CPU0 hotplug"
22602c922cd0SKees Cook	depends on HOTPLUG_CPU
2261a7f7f624SMasahiro Yamada	help
2262a71c8bc5SFenghua Yu	  Enabling this option offlines CPU0 (if CPU0 can be offlined) as
2263a71c8bc5SFenghua Yu	  soon as possible and boots up userspace with CPU0 offlined. User
2264a71c8bc5SFenghua Yu	  can online CPU0 back after boot time.
2265a71c8bc5SFenghua Yu
2266a71c8bc5SFenghua Yu	  To debug CPU0 hotplug, you need to enable CPU0 offline/online
2267a71c8bc5SFenghua Yu	  feature by either turning on CONFIG_BOOTPARAM_HOTPLUG_CPU0 during
2268a71c8bc5SFenghua Yu	  compilation or giving cpu0_hotplug kernel parameter at boot.
2269a71c8bc5SFenghua Yu
2270a71c8bc5SFenghua Yu	  If unsure, say N.
2271a71c8bc5SFenghua Yu
2272506f1d07SSam Ravnborgconfig COMPAT_VDSO
2273b0b49f26SAndy Lutomirski	def_bool n
2274b0b49f26SAndy Lutomirski	prompt "Disable the 32-bit vDSO (needed for glibc 2.3.3)"
2275953fee1dSIngo Molnar	depends on COMPAT_32
2276a7f7f624SMasahiro Yamada	help
2277b0b49f26SAndy Lutomirski	  Certain buggy versions of glibc will crash if they are
2278b0b49f26SAndy Lutomirski	  presented with a 32-bit vDSO that is not mapped at the address
2279b0b49f26SAndy Lutomirski	  indicated in its segment table.
2280e84446deSRandy Dunlap
2281b0b49f26SAndy Lutomirski	  The bug was introduced by f866314b89d56845f55e6f365e18b31ec978ec3a
2282b0b49f26SAndy Lutomirski	  and fixed by 3b3ddb4f7db98ec9e912ccdf54d35df4aa30e04a and
2283b0b49f26SAndy Lutomirski	  49ad572a70b8aeb91e57483a11dd1b77e31c4468.  Glibc 2.3.3 is
2284b0b49f26SAndy Lutomirski	  the only released version with the bug, but OpenSUSE 9
2285b0b49f26SAndy Lutomirski	  contains a buggy "glibc 2.3.2".
2286506f1d07SSam Ravnborg
2287b0b49f26SAndy Lutomirski	  The symptom of the bug is that everything crashes on startup, saying:
2288b0b49f26SAndy Lutomirski	  dl_main: Assertion `(void *) ph->p_vaddr == _rtld_local._dl_sysinfo_dso' failed!
2289b0b49f26SAndy Lutomirski
2290b0b49f26SAndy Lutomirski	  Saying Y here changes the default value of the vdso32 boot
2291b0b49f26SAndy Lutomirski	  option from 1 to 0, which turns off the 32-bit vDSO entirely.
2292b0b49f26SAndy Lutomirski	  This works around the glibc bug but hurts performance.
2293b0b49f26SAndy Lutomirski
2294b0b49f26SAndy Lutomirski	  If unsure, say N: if you are compiling your own kernel, you
2295b0b49f26SAndy Lutomirski	  are unlikely to be using a buggy version of glibc.
2296506f1d07SSam Ravnborg
22973dc33bd3SKees Cookchoice
22983dc33bd3SKees Cook	prompt "vsyscall table for legacy applications"
22993dc33bd3SKees Cook	depends on X86_64
2300625b7b7fSAndy Lutomirski	default LEGACY_VSYSCALL_XONLY
23013dc33bd3SKees Cook	help
23023dc33bd3SKees Cook	  Legacy user code that does not know how to find the vDSO expects
23033dc33bd3SKees Cook	  to be able to issue three syscalls by calling fixed addresses in
23043dc33bd3SKees Cook	  kernel space. Since this location is not randomized with ASLR,
23053dc33bd3SKees Cook	  it can be used to assist security vulnerability exploitation.
23063dc33bd3SKees Cook
23073dc33bd3SKees Cook	  This setting can be changed at boot time via the kernel command
2308bd49e16eSAndy Lutomirski	  line parameter vsyscall=[emulate|xonly|none].
23093dc33bd3SKees Cook
23103dc33bd3SKees Cook	  On a system with recent enough glibc (2.14 or newer) and no
23113dc33bd3SKees Cook	  static binaries, you can say None without a performance penalty
23123dc33bd3SKees Cook	  to improve security.
23133dc33bd3SKees Cook
2314bd49e16eSAndy Lutomirski	  If unsure, select "Emulate execution only".
23153dc33bd3SKees Cook
23163dc33bd3SKees Cook	config LEGACY_VSYSCALL_EMULATE
2317bd49e16eSAndy Lutomirski		bool "Full emulation"
23183dc33bd3SKees Cook		help
2319bd49e16eSAndy Lutomirski		  The kernel traps and emulates calls into the fixed vsyscall
2320bd49e16eSAndy Lutomirski		  address mapping. This makes the mapping non-executable, but
2321bd49e16eSAndy Lutomirski		  it still contains readable known contents, which could be
2322bd49e16eSAndy Lutomirski		  used in certain rare security vulnerability exploits. This
2323bd49e16eSAndy Lutomirski		  configuration is recommended when using legacy userspace
2324bd49e16eSAndy Lutomirski		  that still uses vsyscalls along with legacy binary
2325bd49e16eSAndy Lutomirski		  instrumentation tools that require code to be readable.
2326bd49e16eSAndy Lutomirski
2327bd49e16eSAndy Lutomirski		  An example of this type of legacy userspace is running
2328bd49e16eSAndy Lutomirski		  Pin on an old binary that still uses vsyscalls.
2329bd49e16eSAndy Lutomirski
2330bd49e16eSAndy Lutomirski	config LEGACY_VSYSCALL_XONLY
2331bd49e16eSAndy Lutomirski		bool "Emulate execution only"
2332bd49e16eSAndy Lutomirski		help
2333bd49e16eSAndy Lutomirski		  The kernel traps and emulates calls into the fixed vsyscall
2334bd49e16eSAndy Lutomirski		  address mapping and does not allow reads.  This
2335bd49e16eSAndy Lutomirski		  configuration is recommended when userspace might use the
2336bd49e16eSAndy Lutomirski		  legacy vsyscall area but support for legacy binary
2337bd49e16eSAndy Lutomirski		  instrumentation of legacy code is not needed.  It mitigates
2338bd49e16eSAndy Lutomirski		  certain uses of the vsyscall area as an ASLR-bypassing
2339bd49e16eSAndy Lutomirski		  buffer.
23403dc33bd3SKees Cook
23413dc33bd3SKees Cook	config LEGACY_VSYSCALL_NONE
23423dc33bd3SKees Cook		bool "None"
23433dc33bd3SKees Cook		help
23443dc33bd3SKees Cook		  There will be no vsyscall mapping at all. This will
23453dc33bd3SKees Cook		  eliminate any risk of ASLR bypass due to the vsyscall
23463dc33bd3SKees Cook		  fixed address mapping. Attempts to use the vsyscalls
23473dc33bd3SKees Cook		  will be reported to dmesg, so that either old or
23483dc33bd3SKees Cook		  malicious userspace programs can be identified.
23493dc33bd3SKees Cook
23503dc33bd3SKees Cookendchoice
23513dc33bd3SKees Cook
2352516cbf37STim Birdconfig CMDLINE_BOOL
2353516cbf37STim Bird	bool "Built-in kernel command line"
2354a7f7f624SMasahiro Yamada	help
2355516cbf37STim Bird	  Allow for specifying boot arguments to the kernel at
2356516cbf37STim Bird	  build time.  On some systems (e.g. embedded ones), it is
2357516cbf37STim Bird	  necessary or convenient to provide some or all of the
2358516cbf37STim Bird	  kernel boot arguments with the kernel itself (that is,
2359516cbf37STim Bird	  to not rely on the boot loader to provide them.)
2360516cbf37STim Bird
2361516cbf37STim Bird	  To compile command line arguments into the kernel,
2362516cbf37STim Bird	  set this option to 'Y', then fill in the
236369711ca1SSébastien Hinderer	  boot arguments in CONFIG_CMDLINE.
2364516cbf37STim Bird
2365516cbf37STim Bird	  Systems with fully functional boot loaders (i.e. non-embedded)
2366516cbf37STim Bird	  should leave this option set to 'N'.
2367516cbf37STim Bird
2368516cbf37STim Birdconfig CMDLINE
2369516cbf37STim Bird	string "Built-in kernel command string"
2370516cbf37STim Bird	depends on CMDLINE_BOOL
2371516cbf37STim Bird	default ""
2372a7f7f624SMasahiro Yamada	help
2373516cbf37STim Bird	  Enter arguments here that should be compiled into the kernel
2374516cbf37STim Bird	  image and used at boot time.  If the boot loader provides a
2375516cbf37STim Bird	  command line at boot time, it is appended to this string to
2376516cbf37STim Bird	  form the full kernel command line, when the system boots.
2377516cbf37STim Bird
2378516cbf37STim Bird	  However, you can use the CONFIG_CMDLINE_OVERRIDE option to
2379516cbf37STim Bird	  change this behavior.
2380516cbf37STim Bird
2381516cbf37STim Bird	  In most cases, the command line (whether built-in or provided
2382516cbf37STim Bird	  by the boot loader) should specify the device for the root
2383516cbf37STim Bird	  file system.
2384516cbf37STim Bird
2385516cbf37STim Birdconfig CMDLINE_OVERRIDE
2386516cbf37STim Bird	bool "Built-in command line overrides boot loader arguments"
2387645e6466SAnders Roxell	depends on CMDLINE_BOOL && CMDLINE != ""
2388a7f7f624SMasahiro Yamada	help
2389516cbf37STim Bird	  Set this option to 'Y' to have the kernel ignore the boot loader
2390516cbf37STim Bird	  command line, and use ONLY the built-in command line.
2391516cbf37STim Bird
2392516cbf37STim Bird	  This is used to work around broken boot loaders.  This should
2393516cbf37STim Bird	  be set to 'N' under normal conditions.
2394516cbf37STim Bird
2395a5b9e5a2SAndy Lutomirskiconfig MODIFY_LDT_SYSCALL
2396a5b9e5a2SAndy Lutomirski	bool "Enable the LDT (local descriptor table)" if EXPERT
2397a5b9e5a2SAndy Lutomirski	default y
2398a7f7f624SMasahiro Yamada	help
2399a5b9e5a2SAndy Lutomirski	  Linux can allow user programs to install a per-process x86
2400a5b9e5a2SAndy Lutomirski	  Local Descriptor Table (LDT) using the modify_ldt(2) system
2401a5b9e5a2SAndy Lutomirski	  call.  This is required to run 16-bit or segmented code such as
2402a5b9e5a2SAndy Lutomirski	  DOSEMU or some Wine programs.  It is also used by some very old
2403a5b9e5a2SAndy Lutomirski	  threading libraries.
2404a5b9e5a2SAndy Lutomirski
2405a5b9e5a2SAndy Lutomirski	  Enabling this feature adds a small amount of overhead to
2406a5b9e5a2SAndy Lutomirski	  context switches and increases the low-level kernel attack
2407a5b9e5a2SAndy Lutomirski	  surface.  Disabling it removes the modify_ldt(2) system call.
2408a5b9e5a2SAndy Lutomirski
2409a5b9e5a2SAndy Lutomirski	  Saying 'N' here may make sense for embedded or server kernels.
2410a5b9e5a2SAndy Lutomirski
2411b700e7f0SSeth Jenningssource "kernel/livepatch/Kconfig"
2412b700e7f0SSeth Jennings
2413506f1d07SSam Ravnborgendmenu
2414506f1d07SSam Ravnborg
24153072e413SMichal Hockoconfig ARCH_HAS_ADD_PAGES
24163072e413SMichal Hocko	def_bool y
24173072e413SMichal Hocko	depends on X86_64 && ARCH_ENABLE_MEMORY_HOTPLUG
24183072e413SMichal Hocko
2419506f1d07SSam Ravnborgconfig ARCH_ENABLE_MEMORY_HOTPLUG
2420506f1d07SSam Ravnborg	def_bool y
2421506f1d07SSam Ravnborg	depends on X86_64 || (X86_32 && HIGHMEM)
2422506f1d07SSam Ravnborg
242335551053SGary Hadeconfig ARCH_ENABLE_MEMORY_HOTREMOVE
242435551053SGary Hade	def_bool y
242535551053SGary Hade	depends on MEMORY_HOTPLUG
242635551053SGary Hade
2427e534c7c5SLee Schermerhornconfig USE_PERCPU_NUMA_NODE_ID
2428645a7919STejun Heo	def_bool y
2429e534c7c5SLee Schermerhorn	depends on NUMA
2430e534c7c5SLee Schermerhorn
24319491846fSKirill A. Shutemovconfig ARCH_ENABLE_SPLIT_PMD_PTLOCK
24329491846fSKirill A. Shutemov	def_bool y
24339491846fSKirill A. Shutemov	depends on X86_64 || X86_PAE
24349491846fSKirill A. Shutemov
2435c177c81eSNaoya Horiguchiconfig ARCH_ENABLE_HUGEPAGE_MIGRATION
2436c177c81eSNaoya Horiguchi	def_bool y
2437c177c81eSNaoya Horiguchi	depends on X86_64 && HUGETLB_PAGE && MIGRATION
2438c177c81eSNaoya Horiguchi
24399c670ea3SNaoya Horiguchiconfig ARCH_ENABLE_THP_MIGRATION
24409c670ea3SNaoya Horiguchi	def_bool y
24419c670ea3SNaoya Horiguchi	depends on X86_64 && TRANSPARENT_HUGEPAGE
24429c670ea3SNaoya Horiguchi
2443da85f865SBjorn Helgaasmenu "Power management and ACPI options"
2444e279b6c1SSam Ravnborg
2445e279b6c1SSam Ravnborgconfig ARCH_HIBERNATION_HEADER
24463c2362e6SHarvey Harrison	def_bool y
244744556530SZhimin Gu	depends on HIBERNATION
2448e279b6c1SSam Ravnborg
2449e279b6c1SSam Ravnborgsource "kernel/power/Kconfig"
2450e279b6c1SSam Ravnborg
2451e279b6c1SSam Ravnborgsource "drivers/acpi/Kconfig"
2452e279b6c1SSam Ravnborg
2453efafc8b2SFeng Tangsource "drivers/sfi/Kconfig"
2454efafc8b2SFeng Tang
2455a6b68076SAndi Kleenconfig X86_APM_BOOT
24566fc108a0SJan Beulich	def_bool y
2457282e5aabSPaul Bolle	depends on APM
2458a6b68076SAndi Kleen
2459e279b6c1SSam Ravnborgmenuconfig APM
2460e279b6c1SSam Ravnborg	tristate "APM (Advanced Power Management) BIOS support"
2461efefa6f6SIngo Molnar	depends on X86_32 && PM_SLEEP
2462a7f7f624SMasahiro Yamada	help
2463e279b6c1SSam Ravnborg	  APM is a BIOS specification for saving power using several different
2464e279b6c1SSam Ravnborg	  techniques. This is mostly useful for battery powered laptops with
2465e279b6c1SSam Ravnborg	  APM compliant BIOSes. If you say Y here, the system time will be
2466e279b6c1SSam Ravnborg	  reset after a RESUME operation, the /proc/apm device will provide
2467e279b6c1SSam Ravnborg	  battery status information, and user-space programs will receive
2468e279b6c1SSam Ravnborg	  notification of APM "events" (e.g. battery status change).
2469e279b6c1SSam Ravnborg
2470e279b6c1SSam Ravnborg	  If you select "Y" here, you can disable actual use of the APM
2471e279b6c1SSam Ravnborg	  BIOS by passing the "apm=off" option to the kernel at boot time.
2472e279b6c1SSam Ravnborg
2473e279b6c1SSam Ravnborg	  Note that the APM support is almost completely disabled for
2474e279b6c1SSam Ravnborg	  machines with more than one CPU.
2475e279b6c1SSam Ravnborg
2476e279b6c1SSam Ravnborg	  In order to use APM, you will need supporting software. For location
2477151f4e2bSMauro Carvalho Chehab	  and more information, read <file:Documentation/power/apm-acpi.rst>
24782dc98fd3SMichael Witten	  and the Battery Powered Linux mini-HOWTO, available from
2479e279b6c1SSam Ravnborg	  <http://www.tldp.org/docs.html#howto>.
2480e279b6c1SSam Ravnborg
2481e279b6c1SSam Ravnborg	  This driver does not spin down disk drives (see the hdparm(8)
2482e279b6c1SSam Ravnborg	  manpage ("man 8 hdparm") for that), and it doesn't turn off
2483e279b6c1SSam Ravnborg	  VESA-compliant "green" monitors.
2484e279b6c1SSam Ravnborg
2485e279b6c1SSam Ravnborg	  This driver does not support the TI 4000M TravelMate and the ACER
2486e279b6c1SSam Ravnborg	  486/DX4/75 because they don't have compliant BIOSes. Many "green"
2487e279b6c1SSam Ravnborg	  desktop machines also don't have compliant BIOSes, and this driver
2488e279b6c1SSam Ravnborg	  may cause those machines to panic during the boot phase.
2489e279b6c1SSam Ravnborg
2490e279b6c1SSam Ravnborg	  Generally, if you don't have a battery in your machine, there isn't
2491e279b6c1SSam Ravnborg	  much point in using this driver and you should say N. If you get
2492e279b6c1SSam Ravnborg	  random kernel OOPSes or reboots that don't seem to be related to
2493e279b6c1SSam Ravnborg	  anything, try disabling/enabling this option (or disabling/enabling
2494e279b6c1SSam Ravnborg	  APM in your BIOS).
2495e279b6c1SSam Ravnborg
2496e279b6c1SSam Ravnborg	  Some other things you should try when experiencing seemingly random,
2497e279b6c1SSam Ravnborg	  "weird" problems:
2498e279b6c1SSam Ravnborg
2499e279b6c1SSam Ravnborg	  1) make sure that you have enough swap space and that it is
2500e279b6c1SSam Ravnborg	  enabled.
2501e279b6c1SSam Ravnborg	  2) pass the "no-hlt" option to the kernel
2502e279b6c1SSam Ravnborg	  3) switch on floating point emulation in the kernel and pass
2503e279b6c1SSam Ravnborg	  the "no387" option to the kernel
2504e279b6c1SSam Ravnborg	  4) pass the "floppy=nodma" option to the kernel
2505e279b6c1SSam Ravnborg	  5) pass the "mem=4M" option to the kernel (thereby disabling
2506e279b6c1SSam Ravnborg	  all but the first 4 MB of RAM)
2507e279b6c1SSam Ravnborg	  6) make sure that the CPU is not over clocked.
2508e279b6c1SSam Ravnborg	  7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/>
2509e279b6c1SSam Ravnborg	  8) disable the cache from your BIOS settings
2510e279b6c1SSam Ravnborg	  9) install a fan for the video card or exchange video RAM
2511e279b6c1SSam Ravnborg	  10) install a better fan for the CPU
2512e279b6c1SSam Ravnborg	  11) exchange RAM chips
2513e279b6c1SSam Ravnborg	  12) exchange the motherboard.
2514e279b6c1SSam Ravnborg
2515e279b6c1SSam Ravnborg	  To compile this driver as a module, choose M here: the
2516e279b6c1SSam Ravnborg	  module will be called apm.
2517e279b6c1SSam Ravnborg
2518e279b6c1SSam Ravnborgif APM
2519e279b6c1SSam Ravnborg
2520e279b6c1SSam Ravnborgconfig APM_IGNORE_USER_SUSPEND
2521e279b6c1SSam Ravnborg	bool "Ignore USER SUSPEND"
2522a7f7f624SMasahiro Yamada	help
2523e279b6c1SSam Ravnborg	  This option will ignore USER SUSPEND requests. On machines with a
2524e279b6c1SSam Ravnborg	  compliant APM BIOS, you want to say N. However, on the NEC Versa M
2525e279b6c1SSam Ravnborg	  series notebooks, it is necessary to say Y because of a BIOS bug.
2526e279b6c1SSam Ravnborg
2527e279b6c1SSam Ravnborgconfig APM_DO_ENABLE
2528e279b6c1SSam Ravnborg	bool "Enable PM at boot time"
2529a7f7f624SMasahiro Yamada	help
2530e279b6c1SSam Ravnborg	  Enable APM features at boot time. From page 36 of the APM BIOS
2531e279b6c1SSam Ravnborg	  specification: "When disabled, the APM BIOS does not automatically
2532e279b6c1SSam Ravnborg	  power manage devices, enter the Standby State, enter the Suspend
2533e279b6c1SSam Ravnborg	  State, or take power saving steps in response to CPU Idle calls."
2534e279b6c1SSam Ravnborg	  This driver will make CPU Idle calls when Linux is idle (unless this
2535e279b6c1SSam Ravnborg	  feature is turned off -- see "Do CPU IDLE calls", below). This
2536e279b6c1SSam Ravnborg	  should always save battery power, but more complicated APM features
2537e279b6c1SSam Ravnborg	  will be dependent on your BIOS implementation. You may need to turn
2538e279b6c1SSam Ravnborg	  this option off if your computer hangs at boot time when using APM
2539e279b6c1SSam Ravnborg	  support, or if it beeps continuously instead of suspending. Turn
2540e279b6c1SSam Ravnborg	  this off if you have a NEC UltraLite Versa 33/C or a Toshiba
2541e279b6c1SSam Ravnborg	  T400CDT. This is off by default since most machines do fine without
2542e279b6c1SSam Ravnborg	  this feature.
2543e279b6c1SSam Ravnborg
2544e279b6c1SSam Ravnborgconfig APM_CPU_IDLE
2545dd8af076SLen Brown	depends on CPU_IDLE
2546e279b6c1SSam Ravnborg	bool "Make CPU Idle calls when idle"
2547a7f7f624SMasahiro Yamada	help
2548e279b6c1SSam Ravnborg	  Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop.
2549e279b6c1SSam Ravnborg	  On some machines, this can activate improved power savings, such as
2550e279b6c1SSam Ravnborg	  a slowed CPU clock rate, when the machine is idle. These idle calls
2551e279b6c1SSam Ravnborg	  are made after the idle loop has run for some length of time (e.g.,
2552e279b6c1SSam Ravnborg	  333 mS). On some machines, this will cause a hang at boot time or
2553e279b6c1SSam Ravnborg	  whenever the CPU becomes idle. (On machines with more than one CPU,
2554e279b6c1SSam Ravnborg	  this option does nothing.)
2555e279b6c1SSam Ravnborg
2556e279b6c1SSam Ravnborgconfig APM_DISPLAY_BLANK
2557e279b6c1SSam Ravnborg	bool "Enable console blanking using APM"
2558a7f7f624SMasahiro Yamada	help
2559e279b6c1SSam Ravnborg	  Enable console blanking using the APM. Some laptops can use this to
2560e279b6c1SSam Ravnborg	  turn off the LCD backlight when the screen blanker of the Linux
2561e279b6c1SSam Ravnborg	  virtual console blanks the screen. Note that this is only used by
2562e279b6c1SSam Ravnborg	  the virtual console screen blanker, and won't turn off the backlight
2563e279b6c1SSam Ravnborg	  when using the X Window system. This also doesn't have anything to
2564e279b6c1SSam Ravnborg	  do with your VESA-compliant power-saving monitor. Further, this
2565e279b6c1SSam Ravnborg	  option doesn't work for all laptops -- it might not turn off your
2566e279b6c1SSam Ravnborg	  backlight at all, or it might print a lot of errors to the console,
2567e279b6c1SSam Ravnborg	  especially if you are using gpm.
2568e279b6c1SSam Ravnborg
2569e279b6c1SSam Ravnborgconfig APM_ALLOW_INTS
2570e279b6c1SSam Ravnborg	bool "Allow interrupts during APM BIOS calls"
2571a7f7f624SMasahiro Yamada	help
2572e279b6c1SSam Ravnborg	  Normally we disable external interrupts while we are making calls to
2573e279b6c1SSam Ravnborg	  the APM BIOS as a measure to lessen the effects of a badly behaving
2574e279b6c1SSam Ravnborg	  BIOS implementation.  The BIOS should reenable interrupts if it
2575e279b6c1SSam Ravnborg	  needs to.  Unfortunately, some BIOSes do not -- especially those in
2576e279b6c1SSam Ravnborg	  many of the newer IBM Thinkpads.  If you experience hangs when you
2577e279b6c1SSam Ravnborg	  suspend, try setting this to Y.  Otherwise, say N.
2578e279b6c1SSam Ravnborg
2579e279b6c1SSam Ravnborgendif # APM
2580e279b6c1SSam Ravnborg
2581bb0a56ecSDave Jonessource "drivers/cpufreq/Kconfig"
2582e279b6c1SSam Ravnborg
2583e279b6c1SSam Ravnborgsource "drivers/cpuidle/Kconfig"
2584e279b6c1SSam Ravnborg
258527471fdbSAndy Henroidsource "drivers/idle/Kconfig"
258627471fdbSAndy Henroid
2587e279b6c1SSam Ravnborgendmenu
2588e279b6c1SSam Ravnborg
2589e279b6c1SSam Ravnborg
2590e279b6c1SSam Ravnborgmenu "Bus options (PCI etc.)"
2591e279b6c1SSam Ravnborg
2592e279b6c1SSam Ravnborgchoice
2593e279b6c1SSam Ravnborg	prompt "PCI access mode"
2594efefa6f6SIngo Molnar	depends on X86_32 && PCI
2595e279b6c1SSam Ravnborg	default PCI_GOANY
2596a7f7f624SMasahiro Yamada	help
2597e279b6c1SSam Ravnborg	  On PCI systems, the BIOS can be used to detect the PCI devices and
2598e279b6c1SSam Ravnborg	  determine their configuration. However, some old PCI motherboards
2599e279b6c1SSam Ravnborg	  have BIOS bugs and may crash if this is done. Also, some embedded
2600e279b6c1SSam Ravnborg	  PCI-based systems don't have any BIOS at all. Linux can also try to
2601e279b6c1SSam Ravnborg	  detect the PCI hardware directly without using the BIOS.
2602e279b6c1SSam Ravnborg
2603e279b6c1SSam Ravnborg	  With this option, you can specify how Linux should detect the
2604e279b6c1SSam Ravnborg	  PCI devices. If you choose "BIOS", the BIOS will be used,
2605e279b6c1SSam Ravnborg	  if you choose "Direct", the BIOS won't be used, and if you
2606e279b6c1SSam Ravnborg	  choose "MMConfig", then PCI Express MMCONFIG will be used.
2607e279b6c1SSam Ravnborg	  If you choose "Any", the kernel will try MMCONFIG, then the
2608e279b6c1SSam Ravnborg	  direct access method and falls back to the BIOS if that doesn't
2609e279b6c1SSam Ravnborg	  work. If unsure, go with the default, which is "Any".
2610e279b6c1SSam Ravnborg
2611e279b6c1SSam Ravnborgconfig PCI_GOBIOS
2612e279b6c1SSam Ravnborg	bool "BIOS"
2613e279b6c1SSam Ravnborg
2614e279b6c1SSam Ravnborgconfig PCI_GOMMCONFIG
2615e279b6c1SSam Ravnborg	bool "MMConfig"
2616e279b6c1SSam Ravnborg
2617e279b6c1SSam Ravnborgconfig PCI_GODIRECT
2618e279b6c1SSam Ravnborg	bool "Direct"
2619e279b6c1SSam Ravnborg
26203ef0e1f8SAndres Salomonconfig PCI_GOOLPC
262176fb6570SDaniel Drake	bool "OLPC XO-1"
26223ef0e1f8SAndres Salomon	depends on OLPC
26233ef0e1f8SAndres Salomon
26242bdd1b03SAndres Salomonconfig PCI_GOANY
26252bdd1b03SAndres Salomon	bool "Any"
26262bdd1b03SAndres Salomon
2627e279b6c1SSam Ravnborgendchoice
2628e279b6c1SSam Ravnborg
2629e279b6c1SSam Ravnborgconfig PCI_BIOS
26303c2362e6SHarvey Harrison	def_bool y
2631efefa6f6SIngo Molnar	depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY)
2632e279b6c1SSam Ravnborg
2633e279b6c1SSam Ravnborg# x86-64 doesn't support PCI BIOS access from long mode so always go direct.
2634e279b6c1SSam Ravnborgconfig PCI_DIRECT
26353c2362e6SHarvey Harrison	def_bool y
26360aba496fSShaohua Li	depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC || PCI_GOMMCONFIG))
2637e279b6c1SSam Ravnborg
2638e279b6c1SSam Ravnborgconfig PCI_MMCONFIG
2639b45c9f36SJan Kiszka	bool "Support mmconfig PCI config space access" if X86_64
2640b45c9f36SJan Kiszka	default y
26418364e1f8SJan Kiszka	depends on PCI && (ACPI || SFI || JAILHOUSE_GUEST)
2642b45c9f36SJan Kiszka	depends on X86_64 || (PCI_GOANY || PCI_GOMMCONFIG)
2643e279b6c1SSam Ravnborg
26443ef0e1f8SAndres Salomonconfig PCI_OLPC
26452bdd1b03SAndres Salomon	def_bool y
26462bdd1b03SAndres Salomon	depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY)
26473ef0e1f8SAndres Salomon
2648b5401a96SAlex Nixonconfig PCI_XEN
2649b5401a96SAlex Nixon	def_bool y
2650b5401a96SAlex Nixon	depends on PCI && XEN
2651b5401a96SAlex Nixon	select SWIOTLB_XEN
2652b5401a96SAlex Nixon
26538364e1f8SJan Kiszkaconfig MMCONF_FAM10H
26548364e1f8SJan Kiszka	def_bool y
26558364e1f8SJan Kiszka	depends on X86_64 && PCI_MMCONFIG && ACPI
2656e279b6c1SSam Ravnborg
26573f6ea84aSIra W. Snyderconfig PCI_CNB20LE_QUIRK
26586a108a14SDavid Rientjes	bool "Read CNB20LE Host Bridge Windows" if EXPERT
26596ea30386SKees Cook	depends on PCI
26603f6ea84aSIra W. Snyder	help
26613f6ea84aSIra W. Snyder	  Read the PCI windows out of the CNB20LE host bridge. This allows
26623f6ea84aSIra W. Snyder	  PCI hotplug to work on systems with the CNB20LE chipset which do
26633f6ea84aSIra W. Snyder	  not have ACPI.
26643f6ea84aSIra W. Snyder
266564a5fed6SBjorn Helgaas	  There's no public spec for this chipset, and this functionality
266664a5fed6SBjorn Helgaas	  is known to be incomplete.
266764a5fed6SBjorn Helgaas
266864a5fed6SBjorn Helgaas	  You should say N unless you know you need this.
266964a5fed6SBjorn Helgaas
26703a495511SWilliam Breathitt Grayconfig ISA_BUS
267117a2a129SWilliam Breathitt Gray	bool "ISA bus support on modern systems" if EXPERT
26723a495511SWilliam Breathitt Gray	help
267317a2a129SWilliam Breathitt Gray	  Expose ISA bus device drivers and options available for selection and
267417a2a129SWilliam Breathitt Gray	  configuration. Enable this option if your target machine has an ISA
267517a2a129SWilliam Breathitt Gray	  bus. ISA is an older system, displaced by PCI and newer bus
267617a2a129SWilliam Breathitt Gray	  architectures -- if your target machine is modern, it probably does
267717a2a129SWilliam Breathitt Gray	  not have an ISA bus.
26783a495511SWilliam Breathitt Gray
26793a495511SWilliam Breathitt Gray	  If unsure, say N.
26803a495511SWilliam Breathitt Gray
26811c00f016SDavid Rientjes# x86_64 have no ISA slots, but can have ISA-style DMA.
2682e279b6c1SSam Ravnborgconfig ISA_DMA_API
26831c00f016SDavid Rientjes	bool "ISA-style DMA support" if (X86_64 && EXPERT)
26841c00f016SDavid Rientjes	default y
26851c00f016SDavid Rientjes	help
26861c00f016SDavid Rientjes	  Enables ISA-style DMA support for devices requiring such controllers.
26871c00f016SDavid Rientjes	  If unsure, say Y.
2688e279b6c1SSam Ravnborg
268951e68d05SLinus Torvaldsif X86_32
269051e68d05SLinus Torvalds
2691e279b6c1SSam Ravnborgconfig ISA
2692e279b6c1SSam Ravnborg	bool "ISA support"
2693a7f7f624SMasahiro Yamada	help
2694e279b6c1SSam Ravnborg	  Find out whether you have ISA slots on your motherboard.  ISA is the
2695e279b6c1SSam Ravnborg	  name of a bus system, i.e. the way the CPU talks to the other stuff
2696e279b6c1SSam Ravnborg	  inside your box.  Other bus systems are PCI, EISA, MicroChannel
2697e279b6c1SSam Ravnborg	  (MCA) or VESA.  ISA is an older system, now being displaced by PCI;
2698e279b6c1SSam Ravnborg	  newer boards don't support it.  If you have ISA, say Y, otherwise N.
2699e279b6c1SSam Ravnborg
2700e279b6c1SSam Ravnborgconfig SCx200
2701e279b6c1SSam Ravnborg	tristate "NatSemi SCx200 support"
2702a7f7f624SMasahiro Yamada	help
2703e279b6c1SSam Ravnborg	  This provides basic support for National Semiconductor's
2704e279b6c1SSam Ravnborg	  (now AMD's) Geode processors.  The driver probes for the
2705e279b6c1SSam Ravnborg	  PCI-IDs of several on-chip devices, so its a good dependency
2706e279b6c1SSam Ravnborg	  for other scx200_* drivers.
2707e279b6c1SSam Ravnborg
2708e279b6c1SSam Ravnborg	  If compiled as a module, the driver is named scx200.
2709e279b6c1SSam Ravnborg
2710e279b6c1SSam Ravnborgconfig SCx200HR_TIMER
2711e279b6c1SSam Ravnborg	tristate "NatSemi SCx200 27MHz High-Resolution Timer Support"
2712592913ecSJohn Stultz	depends on SCx200
2713e279b6c1SSam Ravnborg	default y
2714a7f7f624SMasahiro Yamada	help
2715e279b6c1SSam Ravnborg	  This driver provides a clocksource built upon the on-chip
2716e279b6c1SSam Ravnborg	  27MHz high-resolution timer.  Its also a workaround for
2717e279b6c1SSam Ravnborg	  NSC Geode SC-1100's buggy TSC, which loses time when the
2718e279b6c1SSam Ravnborg	  processor goes idle (as is done by the scheduler).  The
2719e279b6c1SSam Ravnborg	  other workaround is idle=poll boot option.
2720e279b6c1SSam Ravnborg
27213ef0e1f8SAndres Salomonconfig OLPC
27223ef0e1f8SAndres Salomon	bool "One Laptop Per Child support"
272354008979SThomas Gleixner	depends on !X86_PAE
27243c554946SAndres Salomon	select GPIOLIB
2725dc3119e7SThomas Gleixner	select OF
272645bb1674SDaniel Drake	select OF_PROMTREE
2727b4e51854SGrant Likely	select IRQ_DOMAIN
27280c3d931bSLubomir Rintel	select OLPC_EC
2729a7f7f624SMasahiro Yamada	help
27303ef0e1f8SAndres Salomon	  Add support for detecting the unique features of the OLPC
27313ef0e1f8SAndres Salomon	  XO hardware.
27323ef0e1f8SAndres Salomon
2733a3128588SDaniel Drakeconfig OLPC_XO1_PM
2734a3128588SDaniel Drake	bool "OLPC XO-1 Power Management"
2735fa112cf1SBorislav Petkov	depends on OLPC && MFD_CS5535=y && PM_SLEEP
2736a7f7f624SMasahiro Yamada	help
273797c4cb71SDaniel Drake	  Add support for poweroff and suspend of the OLPC XO-1 laptop.
2738bf1ebf00SDaniel Drake
2739cfee9597SDaniel Drakeconfig OLPC_XO1_RTC
2740cfee9597SDaniel Drake	bool "OLPC XO-1 Real Time Clock"
2741cfee9597SDaniel Drake	depends on OLPC_XO1_PM && RTC_DRV_CMOS
2742a7f7f624SMasahiro Yamada	help
2743cfee9597SDaniel Drake	  Add support for the XO-1 real time clock, which can be used as a
2744cfee9597SDaniel Drake	  programmable wakeup source.
2745cfee9597SDaniel Drake
27467feda8e9SDaniel Drakeconfig OLPC_XO1_SCI
27477feda8e9SDaniel Drake	bool "OLPC XO-1 SCI extras"
274892e830f2SArnd Bergmann	depends on OLPC && OLPC_XO1_PM && GPIO_CS5535=y
2749ed8e47feSRandy Dunlap	depends on INPUT=y
2750d8d01a63SDaniel Drake	select POWER_SUPPLY
2751a7f7f624SMasahiro Yamada	help
27527feda8e9SDaniel Drake	  Add support for SCI-based features of the OLPC XO-1 laptop:
27537bc74b3dSDaniel Drake	   - EC-driven system wakeups
27547feda8e9SDaniel Drake	   - Power button
27557bc74b3dSDaniel Drake	   - Ebook switch
27562cf2baeaSDaniel Drake	   - Lid switch
2757e1040ac6SDaniel Drake	   - AC adapter status updates
2758e1040ac6SDaniel Drake	   - Battery status updates
27597feda8e9SDaniel Drake
2760a0f30f59SDaniel Drakeconfig OLPC_XO15_SCI
2761a0f30f59SDaniel Drake	bool "OLPC XO-1.5 SCI extras"
2762d8d01a63SDaniel Drake	depends on OLPC && ACPI
2763d8d01a63SDaniel Drake	select POWER_SUPPLY
2764a7f7f624SMasahiro Yamada	help
2765a0f30f59SDaniel Drake	  Add support for SCI-based features of the OLPC XO-1.5 laptop:
2766a0f30f59SDaniel Drake	   - EC-driven system wakeups
2767a0f30f59SDaniel Drake	   - AC adapter status updates
2768a0f30f59SDaniel Drake	   - Battery status updates
2769e279b6c1SSam Ravnborg
2770d4f3e350SEd Wildgooseconfig ALIX
2771d4f3e350SEd Wildgoose	bool "PCEngines ALIX System Support (LED setup)"
2772d4f3e350SEd Wildgoose	select GPIOLIB
2773a7f7f624SMasahiro Yamada	help
2774d4f3e350SEd Wildgoose	  This option enables system support for the PCEngines ALIX.
2775d4f3e350SEd Wildgoose	  At present this just sets up LEDs for GPIO control on
2776d4f3e350SEd Wildgoose	  ALIX2/3/6 boards.  However, other system specific setup should
2777d4f3e350SEd Wildgoose	  get added here.
2778d4f3e350SEd Wildgoose
2779d4f3e350SEd Wildgoose	  Note: You must still enable the drivers for GPIO and LED support
2780d4f3e350SEd Wildgoose	  (GPIO_CS5535 & LEDS_GPIO) to actually use the LEDs
2781d4f3e350SEd Wildgoose
2782d4f3e350SEd Wildgoose	  Note: You have to set alix.force=1 for boards with Award BIOS.
2783d4f3e350SEd Wildgoose
2784da4e3302SPhilip Prindevilleconfig NET5501
2785da4e3302SPhilip Prindeville	bool "Soekris Engineering net5501 System Support (LEDS, GPIO, etc)"
2786da4e3302SPhilip Prindeville	select GPIOLIB
2787a7f7f624SMasahiro Yamada	help
2788da4e3302SPhilip Prindeville	  This option enables system support for the Soekris Engineering net5501.
2789da4e3302SPhilip Prindeville
27903197059aSPhilip A. Prindevilleconfig GEOS
27913197059aSPhilip A. Prindeville	bool "Traverse Technologies GEOS System Support (LEDS, GPIO, etc)"
27923197059aSPhilip A. Prindeville	select GPIOLIB
27933197059aSPhilip A. Prindeville	depends on DMI
2794a7f7f624SMasahiro Yamada	help
27953197059aSPhilip A. Prindeville	  This option enables system support for the Traverse Technologies GEOS.
27963197059aSPhilip A. Prindeville
27977d029125SVivien Didelotconfig TS5500
27987d029125SVivien Didelot	bool "Technologic Systems TS-5500 platform support"
27997d029125SVivien Didelot	depends on MELAN
28007d029125SVivien Didelot	select CHECK_SIGNATURE
28017d029125SVivien Didelot	select NEW_LEDS
28027d029125SVivien Didelot	select LEDS_CLASS
2803a7f7f624SMasahiro Yamada	help
28047d029125SVivien Didelot	  This option enables system support for the Technologic Systems TS-5500.
28057d029125SVivien Didelot
2806e279b6c1SSam Ravnborgendif # X86_32
2807e279b6c1SSam Ravnborg
280823ac4ae8SAndreas Herrmannconfig AMD_NB
2809e279b6c1SSam Ravnborg	def_bool y
28100e152cd7SBorislav Petkov	depends on CPU_SUP_AMD && PCI
2811e279b6c1SSam Ravnborg
2812e3263ab3SDavid Herrmannconfig X86_SYSFB
2813e3263ab3SDavid Herrmann	bool "Mark VGA/VBE/EFI FB as generic system framebuffer"
2814e3263ab3SDavid Herrmann	help
2815e3263ab3SDavid Herrmann	  Firmwares often provide initial graphics framebuffers so the BIOS,
2816e3263ab3SDavid Herrmann	  bootloader or kernel can show basic video-output during boot for
2817e3263ab3SDavid Herrmann	  user-guidance and debugging. Historically, x86 used the VESA BIOS
2818e3263ab3SDavid Herrmann	  Extensions and EFI-framebuffers for this, which are mostly limited
2819e3263ab3SDavid Herrmann	  to x86.
2820e3263ab3SDavid Herrmann	  This option, if enabled, marks VGA/VBE/EFI framebuffers as generic
2821e3263ab3SDavid Herrmann	  framebuffers so the new generic system-framebuffer drivers can be
2822e3263ab3SDavid Herrmann	  used on x86. If the framebuffer is not compatible with the generic
2823e3a5dc08SNikolas Nyby	  modes, it is advertised as fallback platform framebuffer so legacy
2824e3263ab3SDavid Herrmann	  drivers like efifb, vesafb and uvesafb can pick it up.
2825e3263ab3SDavid Herrmann	  If this option is not selected, all system framebuffers are always
2826e3263ab3SDavid Herrmann	  marked as fallback platform framebuffers as usual.
2827e3263ab3SDavid Herrmann
2828e3263ab3SDavid Herrmann	  Note: Legacy fbdev drivers, including vesafb, efifb, uvesafb, will
2829e3263ab3SDavid Herrmann	  not be able to pick up generic system framebuffers if this option
2830e3263ab3SDavid Herrmann	  is selected. You are highly encouraged to enable simplefb as
2831e3263ab3SDavid Herrmann	  replacement if you select this option. simplefb can correctly deal
2832e3263ab3SDavid Herrmann	  with generic system framebuffers. But you should still keep vesafb
2833e3263ab3SDavid Herrmann	  and others enabled as fallback if a system framebuffer is
2834e3263ab3SDavid Herrmann	  incompatible with simplefb.
2835e3263ab3SDavid Herrmann
2836e3263ab3SDavid Herrmann	  If unsure, say Y.
2837e3263ab3SDavid Herrmann
2838e279b6c1SSam Ravnborgendmenu
2839e279b6c1SSam Ravnborg
2840e279b6c1SSam Ravnborg
28411572497cSChristoph Hellwigmenu "Binary Emulations"
2842e279b6c1SSam Ravnborg
2843e279b6c1SSam Ravnborgconfig IA32_EMULATION
2844e279b6c1SSam Ravnborg	bool "IA32 Emulation"
2845e279b6c1SSam Ravnborg	depends on X86_64
284639f88911SIngo Molnar	select ARCH_WANT_OLD_COMPAT_IPC
2847d1603990SRandy Dunlap	select BINFMT_ELF
2848a97f52e6SRoland McGrath	select COMPAT_BINFMT_ELF
284939f88911SIngo Molnar	select COMPAT_OLD_SIGACTION
2850a7f7f624SMasahiro Yamada	help
28515fd92e65SH. J. Lu	  Include code to run legacy 32-bit programs under a
28525fd92e65SH. J. Lu	  64-bit kernel. You should likely turn this on, unless you're
28535fd92e65SH. J. Lu	  100% sure that you don't have any 32-bit programs left.
2854e279b6c1SSam Ravnborg
2855e279b6c1SSam Ravnborgconfig IA32_AOUT
2856e279b6c1SSam Ravnborg	tristate "IA32 a.out support"
28576b213e1bSDavid Woodhouse	depends on IA32_EMULATION
2858eac61655SBorislav Petkov	depends on BROKEN
2859a7f7f624SMasahiro Yamada	help
2860e279b6c1SSam Ravnborg	  Support old a.out binaries in the 32bit emulation.
2861e279b6c1SSam Ravnborg
28620bf62763SH. Peter Anvinconfig X86_X32
28636ea30386SKees Cook	bool "x32 ABI for 64-bit mode"
28649b54050bSBrian Gerst	depends on X86_64
2865a7f7f624SMasahiro Yamada	help
28665fd92e65SH. J. Lu	  Include code to run binaries for the x32 native 32-bit ABI
28675fd92e65SH. J. Lu	  for 64-bit processors.  An x32 process gets access to the
28685fd92e65SH. J. Lu	  full 64-bit register file and wide data path while leaving
28695fd92e65SH. J. Lu	  pointers at 32 bits for smaller memory footprint.
28705fd92e65SH. J. Lu
28715fd92e65SH. J. Lu	  You will need a recent binutils (2.22 or later) with
28725fd92e65SH. J. Lu	  elf32_x86_64 support enabled to compile a kernel with this
28735fd92e65SH. J. Lu	  option set.
28745fd92e65SH. J. Lu
2875953fee1dSIngo Molnarconfig COMPAT_32
2876953fee1dSIngo Molnar	def_bool y
2877953fee1dSIngo Molnar	depends on IA32_EMULATION || X86_32
2878953fee1dSIngo Molnar	select HAVE_UID16
2879953fee1dSIngo Molnar	select OLD_SIGSUSPEND3
2880953fee1dSIngo Molnar
2881e279b6c1SSam Ravnborgconfig COMPAT
28823c2362e6SHarvey Harrison	def_bool y
28830bf62763SH. Peter Anvin	depends on IA32_EMULATION || X86_X32
2884e279b6c1SSam Ravnborg
28853120e25eSJan Beulichif COMPAT
2886e279b6c1SSam Ravnborgconfig COMPAT_FOR_U64_ALIGNMENT
28873120e25eSJan Beulich	def_bool y
2888e279b6c1SSam Ravnborg
2889e279b6c1SSam Ravnborgconfig SYSVIPC_COMPAT
28903c2362e6SHarvey Harrison	def_bool y
28913120e25eSJan Beulich	depends on SYSVIPC
28923120e25eSJan Beulichendif
2893ee009e4aSDavid Howells
2894e279b6c1SSam Ravnborgendmenu
2895e279b6c1SSam Ravnborg
2896e279b6c1SSam Ravnborg
2897e5beae16SKeith Packardconfig HAVE_ATOMIC_IOMAP
2898e5beae16SKeith Packard	def_bool y
2899e5beae16SKeith Packard	depends on X86_32
2900e5beae16SKeith Packard
2901e279b6c1SSam Ravnborgsource "drivers/firmware/Kconfig"
2902e279b6c1SSam Ravnborg
2903edf88417SAvi Kivitysource "arch/x86/kvm/Kconfig"
29045e8ebd84SJason A. Donenfeld
29055e8ebd84SJason A. Donenfeldsource "arch/x86/Kconfig.assembler"
2906