xref: /linux/arch/x86/Kconfig (revision 4eb0716e868eed963967adb0b1b11d9bd8ca1d01)
1b2441318SGreg Kroah-Hartman# SPDX-License-Identifier: GPL-2.0
2daa93fabSSam Ravnborg# Select 32 or 64 bit
3daa93fabSSam Ravnborgconfig 64BIT
4104daea1SMasahiro Yamada	bool "64-bit kernel" if "$(ARCH)" = "x86"
5104daea1SMasahiro Yamada	default "$(ARCH)" != "i386"
68f9ca475SIngo Molnar	---help---
7daa93fabSSam Ravnborg	  Say yes to build a 64-bit kernel - formerly known as x86_64
8daa93fabSSam Ravnborg	  Say no to build a 32-bit kernel - formerly known as i386
9daa93fabSSam Ravnborg
10daa93fabSSam Ravnborgconfig X86_32
113120e25eSJan Beulich	def_bool y
123120e25eSJan Beulich	depends on !64BIT
13341c787eSIngo Molnar	# Options that are inherently 32-bit kernel only:
14341c787eSIngo Molnar	select ARCH_WANT_IPC_PARSE_VERSION
15341c787eSIngo Molnar	select CLKSRC_I8253
16341c787eSIngo Molnar	select CLONE_BACKWARDS
17117ed454SThomas Gleixner	select HAVE_DEBUG_STACKOVERFLOW
18341c787eSIngo Molnar	select MODULES_USE_ELF_REL
19341c787eSIngo Molnar	select OLD_SIGACTION
20daa93fabSSam Ravnborg
21daa93fabSSam Ravnborgconfig X86_64
223120e25eSJan Beulich	def_bool y
233120e25eSJan Beulich	depends on 64BIT
24d94e0685SIngo Molnar	# Options that are inherently 64-bit kernel only:
25*4eb0716eSAlexandre Ghiti	select ARCH_HAS_GIGANTIC_PAGE
26d94e0685SIngo Molnar	select ARCH_SUPPORTS_INT128
27d94e0685SIngo Molnar	select ARCH_USE_CMPXCHG_LOCKREF
28d94e0685SIngo Molnar	select HAVE_ARCH_SOFT_DIRTY
29d94e0685SIngo Molnar	select MODULES_USE_ELF_RELA
30f616ab59SChristoph Hellwig	select NEED_DMA_MAP_STATE
3109230cbcSChristoph Hellwig	select SWIOTLB
32f8781c4aSDominik Brodowski	select ARCH_HAS_SYSCALL_WRAPPER
331032c0baSSam Ravnborg
34d94e0685SIngo Molnar#
35d94e0685SIngo Molnar# Arch settings
36d94e0685SIngo Molnar#
37d94e0685SIngo Molnar# ( Note that options that are marked 'if X86_64' could in principle be
38d94e0685SIngo Molnar#   ported to 32-bit as well. )
39d94e0685SIngo Molnar#
408d5fffb9SSam Ravnborgconfig X86
413c2362e6SHarvey Harrison	def_bool y
42c763ea26SIngo Molnar	#
43c763ea26SIngo Molnar	# Note: keep this list sorted alphabetically
44c763ea26SIngo Molnar	#
456471b825SIngo Molnar	select ACPI_LEGACY_TABLES_LOOKUP	if ACPI
466e0a0ea1SGraeme Gregory	select ACPI_SYSTEM_POWER_STATES_SUPPORT	if ACPI
47942fa985SYury Norov	select ARCH_32BIT_OFF_T			if X86_32
486471b825SIngo Molnar	select ARCH_CLOCKSOURCE_DATA
492a21ad57SThomas Gleixner	select ARCH_CLOCKSOURCE_INIT
506471b825SIngo Molnar	select ARCH_DISCARD_MEMBLOCK
5191dda51aSAleksey Makarov	select ARCH_HAS_ACPI_TABLE_UPGRADE	if ACPI
52fa5b6ec9SLaura Abbott	select ARCH_HAS_DEBUG_VIRTUAL
5321266be9SDan Williams	select ARCH_HAS_DEVMEM_IS_ALLOWED
546471b825SIngo Molnar	select ARCH_HAS_ELF_RANDOMIZE
5572d93104SLinus Torvalds	select ARCH_HAS_FAST_MULTIPLIER
56316d097cSDave Hansen	select ARCH_HAS_FILTER_PGPROT
576974f0c4SDaniel Micay	select ARCH_HAS_FORTIFY_SOURCE
58957e3facSRiku Voipio	select ARCH_HAS_GCOV_PROFILE_ALL
595c9a8750SDmitry Vyukov	select ARCH_HAS_KCOV			if X86_64
6010bcc80eSMathieu Desnoyers	select ARCH_HAS_MEMBARRIER_SYNC_CORE
61c763ea26SIngo Molnar	select ARCH_HAS_PMEM_API		if X86_64
623010a5eaSLaurent Dufour	select ARCH_HAS_PTE_SPECIAL
6339208aa7SKees Cook	select ARCH_HAS_REFCOUNT
640aed55afSDan Williams	select ARCH_HAS_UACCESS_FLUSHCACHE	if X86_64
65092b31aaSDan Williams	select ARCH_HAS_UACCESS_MCSAFE		if X86_64 && X86_MCE
66d2852a22SDaniel Borkmann	select ARCH_HAS_SET_MEMORY
67d253ca0cSRick Edgecombe	select ARCH_HAS_SET_DIRECT_MAP
68ad21fc4fSLaura Abbott	select ARCH_HAS_STRICT_KERNEL_RWX
69ad21fc4fSLaura Abbott	select ARCH_HAS_STRICT_MODULE_RWX
70ac1ab12aSMathieu Desnoyers	select ARCH_HAS_SYNC_CORE_BEFORE_USERMODE
71c6d30853SAndrey Ryabinin	select ARCH_HAS_UBSAN_SANITIZE_ALL
7265f7d049SOliver O'Halloran	select ARCH_HAS_ZONE_DEVICE		if X86_64
736471b825SIngo Molnar	select ARCH_HAVE_NMI_SAFE_CMPXCHG
746471b825SIngo Molnar	select ARCH_MIGHT_HAVE_ACPI_PDC		if ACPI
7577fbbc81SMark Salter	select ARCH_MIGHT_HAVE_PC_PARPORT
765e2c18c0SMark Salter	select ARCH_MIGHT_HAVE_PC_SERIO
773599fe12SThomas Gleixner	select ARCH_STACKWALK
782c870e61SArnd Bergmann	select ARCH_SUPPORTS_ACPI
796471b825SIngo Molnar	select ARCH_SUPPORTS_ATOMIC_RMW
806471b825SIngo Molnar	select ARCH_SUPPORTS_NUMA_BALANCING	if X86_64
816471b825SIngo Molnar	select ARCH_USE_BUILTIN_BSWAP
826471b825SIngo Molnar	select ARCH_USE_QUEUED_RWLOCKS
836471b825SIngo Molnar	select ARCH_USE_QUEUED_SPINLOCKS
84ce4a4e56SAndy Lutomirski	select ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH
85c763ea26SIngo Molnar	select ARCH_WANTS_DYNAMIC_TASK_STRUCT
8638d8b4e6SHuang Ying	select ARCH_WANTS_THP_SWAP		if X86_64
876471b825SIngo Molnar	select BUILDTIME_EXTABLE_SORT
886471b825SIngo Molnar	select CLKEVT_I8253
896471b825SIngo Molnar	select CLOCKSOURCE_VALIDATE_LAST_CYCLE
906471b825SIngo Molnar	select CLOCKSOURCE_WATCHDOG
916471b825SIngo Molnar	select DCACHE_WORD_ACCESS
9245471cd9SLinus Torvalds	select EDAC_ATOMIC_SCRUB
9345471cd9SLinus Torvalds	select EDAC_SUPPORT
946471b825SIngo Molnar	select GENERIC_CLOCKEVENTS
956471b825SIngo Molnar	select GENERIC_CLOCKEVENTS_BROADCAST	if X86_64 || (X86_32 && X86_LOCAL_APIC)
966471b825SIngo Molnar	select GENERIC_CLOCKEVENTS_MIN_ADJUST
976471b825SIngo Molnar	select GENERIC_CMOS_UPDATE
986471b825SIngo Molnar	select GENERIC_CPU_AUTOPROBE
9961dc0f55SThomas Gleixner	select GENERIC_CPU_VULNERABILITIES
1006471b825SIngo Molnar	select GENERIC_EARLY_IOREMAP
1016471b825SIngo Molnar	select GENERIC_FIND_FIRST_BIT
1026471b825SIngo Molnar	select GENERIC_IOMAP
103c7d6c9ddSThomas Gleixner	select GENERIC_IRQ_EFFECTIVE_AFF_MASK	if SMP
1040fa115daSThomas Gleixner	select GENERIC_IRQ_MATRIX_ALLOCATOR	if X86_LOCAL_APIC
105ad7a929fSThomas Gleixner	select GENERIC_IRQ_MIGRATION		if SMP
1066471b825SIngo Molnar	select GENERIC_IRQ_PROBE
107c201c917SThomas Gleixner	select GENERIC_IRQ_RESERVATION_MODE
1086471b825SIngo Molnar	select GENERIC_IRQ_SHOW
1096471b825SIngo Molnar	select GENERIC_PENDING_IRQ		if SMP
1106471b825SIngo Molnar	select GENERIC_SMP_IDLE_THREAD
1116471b825SIngo Molnar	select GENERIC_STRNCPY_FROM_USER
1126471b825SIngo Molnar	select GENERIC_STRNLEN_USER
1136471b825SIngo Molnar	select GENERIC_TIME_VSYSCALL
1147edaeb68SThomas Gleixner	select HARDLOCKUP_CHECK_TIMESTAMP	if X86_64
1156471b825SIngo Molnar	select HAVE_ACPI_APEI			if ACPI
1166471b825SIngo Molnar	select HAVE_ACPI_APEI_NMI		if ACPI
1176471b825SIngo Molnar	select HAVE_ALIGNED_STRUCT_PAGE		if SLUB
1186471b825SIngo Molnar	select HAVE_ARCH_AUDITSYSCALL
1196471b825SIngo Molnar	select HAVE_ARCH_HUGE_VMAP		if X86_64 || X86_PAE
1206471b825SIngo Molnar	select HAVE_ARCH_JUMP_LABEL
121b34006c4SArd Biesheuvel	select HAVE_ARCH_JUMP_LABEL_RELATIVE
122d17a1d97SAndrey Ryabinin	select HAVE_ARCH_KASAN			if X86_64
1236471b825SIngo Molnar	select HAVE_ARCH_KGDB
1249e08f57dSDaniel Cashman	select HAVE_ARCH_MMAP_RND_BITS		if MMU
1259e08f57dSDaniel Cashman	select HAVE_ARCH_MMAP_RND_COMPAT_BITS	if MMU && COMPAT
1261b028f78SDmitry Safonov	select HAVE_ARCH_COMPAT_MMAP_BASES	if MMU && COMPAT
127271ca788SArd Biesheuvel	select HAVE_ARCH_PREL32_RELOCATIONS
1286471b825SIngo Molnar	select HAVE_ARCH_SECCOMP_FILTER
129f7d83c1cSKees Cook	select HAVE_ARCH_THREAD_STRUCT_WHITELIST
130afaef01cSAlexander Popov	select HAVE_ARCH_STACKLEAK
1316471b825SIngo Molnar	select HAVE_ARCH_TRACEHOOK
1326471b825SIngo Molnar	select HAVE_ARCH_TRANSPARENT_HUGEPAGE
133a00cc7d9SMatthew Wilcox	select HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD if X86_64
134e37e43a4SAndy Lutomirski	select HAVE_ARCH_VMAP_STACK		if X86_64
135c763ea26SIngo Molnar	select HAVE_ARCH_WITHIN_STACK_FRAMES
1366471b825SIngo Molnar	select HAVE_CMPXCHG_DOUBLE
1376471b825SIngo Molnar	select HAVE_CMPXCHG_LOCAL
1386471b825SIngo Molnar	select HAVE_CONTEXT_TRACKING		if X86_64
139c1bd55f9SJosh Triplett	select HAVE_COPY_THREAD_TLS
1406471b825SIngo Molnar	select HAVE_C_RECORDMCOUNT
1416471b825SIngo Molnar	select HAVE_DEBUG_KMEMLEAK
1429c5a3621SAkinobu Mita	select HAVE_DMA_CONTIGUOUS
143677aa9f7SSteven Rostedt	select HAVE_DYNAMIC_FTRACE
14406aeaaeaSMasami Hiramatsu	select HAVE_DYNAMIC_FTRACE_WITH_REGS
14503f5781bSWang YanQing	select HAVE_EBPF_JIT
14658340a07SJohannes Berg	select HAVE_EFFICIENT_UNALIGNED_ACCESS
1476630a8e5SChristoph Hellwig	select HAVE_EISA
1485f56a5dfSJiri Slaby	select HAVE_EXIT_THREAD
149644e0e8dSSteven Rostedt (VMware)	select HAVE_FENTRY			if X86_64 || DYNAMIC_FTRACE
1506471b825SIngo Molnar	select HAVE_FTRACE_MCOUNT_RECORD
1516471b825SIngo Molnar	select HAVE_FUNCTION_GRAPH_TRACER
1526471b825SIngo Molnar	select HAVE_FUNCTION_TRACER
1536b90bd4bSEmese Revfy	select HAVE_GCC_PLUGINS
1540067f129SK.Prasad	select HAVE_HW_BREAKPOINT
1556471b825SIngo Molnar	select HAVE_IDE
1566471b825SIngo Molnar	select HAVE_IOREMAP_PROT
1576471b825SIngo Molnar	select HAVE_IRQ_EXIT_ON_IRQ_STACK	if X86_64
1586471b825SIngo Molnar	select HAVE_IRQ_TIME_ACCOUNTING
1596471b825SIngo Molnar	select HAVE_KERNEL_BZIP2
1606471b825SIngo Molnar	select HAVE_KERNEL_GZIP
1616471b825SIngo Molnar	select HAVE_KERNEL_LZ4
1626471b825SIngo Molnar	select HAVE_KERNEL_LZMA
1636471b825SIngo Molnar	select HAVE_KERNEL_LZO
1646471b825SIngo Molnar	select HAVE_KERNEL_XZ
1656471b825SIngo Molnar	select HAVE_KPROBES
1666471b825SIngo Molnar	select HAVE_KPROBES_ON_FTRACE
167540adea3SMasami Hiramatsu	select HAVE_FUNCTION_ERROR_INJECTION
1686471b825SIngo Molnar	select HAVE_KRETPROBES
1696471b825SIngo Molnar	select HAVE_KVM
1706471b825SIngo Molnar	select HAVE_LIVEPATCH			if X86_64
1716471b825SIngo Molnar	select HAVE_MEMBLOCK_NODE_MAP
1720102752eSFrederic Weisbecker	select HAVE_MIXED_BREAKPOINTS_REGS
173ee9f8fceSJosh Poimboeuf	select HAVE_MOD_ARCH_SPECIFIC
1749f132f7eSJoel Fernandes (Google)	select HAVE_MOVE_PMD
17542a0bb3fSPetr Mladek	select HAVE_NMI
1766471b825SIngo Molnar	select HAVE_OPROFILE
1776471b825SIngo Molnar	select HAVE_OPTPROBES
1786471b825SIngo Molnar	select HAVE_PCSPKR_PLATFORM
1796471b825SIngo Molnar	select HAVE_PERF_EVENTS
180c01d4323SFrederic Weisbecker	select HAVE_PERF_EVENTS_NMI
18192e5aae4SNicholas Piggin	select HAVE_HARDLOCKUP_DETECTOR_PERF	if PERF_EVENTS && HAVE_PERF_EVENTS_NMI
182eb01d42aSChristoph Hellwig	select HAVE_PCI
183c5e63197SJiri Olsa	select HAVE_PERF_REGS
184c5ebcedbSJiri Olsa	select HAVE_PERF_USER_STACK_DUMP
18548a8b97cSPeter Zijlstra	select HAVE_RCU_TABLE_FREE		if PARAVIRT
1866471b825SIngo Molnar	select HAVE_REGS_AND_STACK_ACCESS_API
1876415b38bSJiri Slaby	select HAVE_RELIABLE_STACKTRACE		if X86_64 && (UNWINDER_FRAME_POINTER || UNWINDER_ORC) && STACK_VALIDATION
1883c88ee19SMasami Hiramatsu	select HAVE_FUNCTION_ARG_ACCESS_API
189d148eac0SMasahiro Yamada	select HAVE_STACKPROTECTOR		if CC_HAS_SANE_STACKPROTECTOR
190c763ea26SIngo Molnar	select HAVE_STACK_VALIDATION		if X86_64
191d6761b8fSMathieu Desnoyers	select HAVE_RSEQ
1926471b825SIngo Molnar	select HAVE_SYSCALL_TRACEPOINTS
1936471b825SIngo Molnar	select HAVE_UNSTABLE_SCHED_CLOCK
1947c68af6eSAvi Kivity	select HAVE_USER_RETURN_NOTIFIER
19505736e4aSThomas Gleixner	select HOTPLUG_SMT			if SMP
196c0185808SThomas Gleixner	select IRQ_FORCED_THREADING
19786596f0aSChristoph Hellwig	select NEED_SG_DMA_LENGTH
1982eac9c2dSChristoph Hellwig	select PCI_DOMAINS			if PCI
199625210cfSSinan Kaya	select PCI_LOCKLESS_CONFIG		if PCI
2006471b825SIngo Molnar	select PERF_EVENTS
2013195ef59SPrarit Bhargava	select RTC_LIB
202d6faca40SArnd Bergmann	select RTC_MC146818_LIB
2036471b825SIngo Molnar	select SPARSE_IRQ
20483fe27eaSPranith Kumar	select SRCU
2056471b825SIngo Molnar	select SYSCTL_EXCEPTION_TRACE
20615f4eae7SAndy Lutomirski	select THREAD_INFO_IN_TASK
2076471b825SIngo Molnar	select USER_STACKTRACE_SUPPORT
2086471b825SIngo Molnar	select VIRT_TO_BUS
2096471b825SIngo Molnar	select X86_FEATURE_NAMES		if PROC_FS
2107d8330a5SBalbir Singh
211ba7e4d13SIngo Molnarconfig INSTRUCTION_DECODER
2123120e25eSJan Beulich	def_bool y
2133120e25eSJan Beulich	depends on KPROBES || PERF_EVENTS || UPROBES
214ba7e4d13SIngo Molnar
21551b26adaSLinus Torvaldsconfig OUTPUT_FORMAT
21651b26adaSLinus Torvalds	string
21751b26adaSLinus Torvalds	default "elf32-i386" if X86_32
21851b26adaSLinus Torvalds	default "elf64-x86-64" if X86_64
21951b26adaSLinus Torvalds
22073531905SSam Ravnborgconfig ARCH_DEFCONFIG
221b9b39bfbSSam Ravnborg	string
22273531905SSam Ravnborg	default "arch/x86/configs/i386_defconfig" if X86_32
22373531905SSam Ravnborg	default "arch/x86/configs/x86_64_defconfig" if X86_64
224b9b39bfbSSam Ravnborg
2258d5fffb9SSam Ravnborgconfig LOCKDEP_SUPPORT
2263c2362e6SHarvey Harrison	def_bool y
2278d5fffb9SSam Ravnborg
2288d5fffb9SSam Ravnborgconfig STACKTRACE_SUPPORT
2293c2362e6SHarvey Harrison	def_bool y
2308d5fffb9SSam Ravnborg
2318d5fffb9SSam Ravnborgconfig MMU
2323c2362e6SHarvey Harrison	def_bool y
2338d5fffb9SSam Ravnborg
2349e08f57dSDaniel Cashmanconfig ARCH_MMAP_RND_BITS_MIN
2359e08f57dSDaniel Cashman	default 28 if 64BIT
2369e08f57dSDaniel Cashman	default 8
2379e08f57dSDaniel Cashman
2389e08f57dSDaniel Cashmanconfig ARCH_MMAP_RND_BITS_MAX
2399e08f57dSDaniel Cashman	default 32 if 64BIT
2409e08f57dSDaniel Cashman	default 16
2419e08f57dSDaniel Cashman
2429e08f57dSDaniel Cashmanconfig ARCH_MMAP_RND_COMPAT_BITS_MIN
2439e08f57dSDaniel Cashman	default 8
2449e08f57dSDaniel Cashman
2459e08f57dSDaniel Cashmanconfig ARCH_MMAP_RND_COMPAT_BITS_MAX
2469e08f57dSDaniel Cashman	default 16
2479e08f57dSDaniel Cashman
2488d5fffb9SSam Ravnborgconfig SBUS
2498d5fffb9SSam Ravnborg	bool
2508d5fffb9SSam Ravnborg
2518d5fffb9SSam Ravnborgconfig GENERIC_ISA_DMA
2523120e25eSJan Beulich	def_bool y
2533120e25eSJan Beulich	depends on ISA_DMA_API
2548d5fffb9SSam Ravnborg
2558d5fffb9SSam Ravnborgconfig GENERIC_BUG
2563c2362e6SHarvey Harrison	def_bool y
2578d5fffb9SSam Ravnborg	depends on BUG
258b93a531eSJan Beulich	select GENERIC_BUG_RELATIVE_POINTERS if X86_64
259b93a531eSJan Beulich
260b93a531eSJan Beulichconfig GENERIC_BUG_RELATIVE_POINTERS
261b93a531eSJan Beulich	bool
2628d5fffb9SSam Ravnborg
2638d5fffb9SSam Ravnborgconfig GENERIC_HWEIGHT
2643c2362e6SHarvey Harrison	def_bool y
2658d5fffb9SSam Ravnborg
2668d5fffb9SSam Ravnborgconfig ARCH_MAY_HAVE_PC_FDC
2673120e25eSJan Beulich	def_bool y
2683120e25eSJan Beulich	depends on ISA_DMA_API
2698d5fffb9SSam Ravnborg
2701032c0baSSam Ravnborgconfig GENERIC_CALIBRATE_DELAY
2711032c0baSSam Ravnborg	def_bool y
2721032c0baSSam Ravnborg
2739a0b8415Svenkatesh.pallipadi@intel.comconfig ARCH_HAS_CPU_RELAX
2749a0b8415Svenkatesh.pallipadi@intel.com	def_bool y
2758d5fffb9SSam Ravnborg
2761b27d05bSPekka Enbergconfig ARCH_HAS_CACHE_LINE_SIZE
2771b27d05bSPekka Enberg	def_bool y
2781b27d05bSPekka Enberg
279316d097cSDave Hansenconfig ARCH_HAS_FILTER_PGPROT
280316d097cSDave Hansen	def_bool y
281316d097cSDave Hansen
282dd5af90aSMike Travisconfig HAVE_SETUP_PER_CPU_AREA
28389c9c4c5SBrian Gerst	def_bool y
284b32ef636Stravis@sgi.com
28508fc4580STejun Heoconfig NEED_PER_CPU_EMBED_FIRST_CHUNK
28608fc4580STejun Heo	def_bool y
28708fc4580STejun Heo
28808fc4580STejun Heoconfig NEED_PER_CPU_PAGE_FIRST_CHUNK
28911124411STejun Heo	def_bool y
29011124411STejun Heo
291801e4062SJohannes Bergconfig ARCH_HIBERNATION_POSSIBLE
292801e4062SJohannes Berg	def_bool y
293801e4062SJohannes Berg
294f4cb5700SJohannes Bergconfig ARCH_SUSPEND_POSSIBLE
295f4cb5700SJohannes Berg	def_bool y
296f4cb5700SJohannes Berg
297cfe28c5dSSteve Capperconfig ARCH_WANT_HUGE_PMD_SHARE
298cfe28c5dSSteve Capper	def_bool y
299cfe28c5dSSteve Capper
30053313b2cSSteve Capperconfig ARCH_WANT_GENERAL_HUGETLB
30153313b2cSSteve Capper	def_bool y
30253313b2cSSteve Capper
3038d5fffb9SSam Ravnborgconfig ZONE_DMA32
304e0fd24a3SJan Beulich	def_bool y if X86_64
3058d5fffb9SSam Ravnborg
3068d5fffb9SSam Ravnborgconfig AUDIT_ARCH
307e0fd24a3SJan Beulich	def_bool y if X86_64
3088d5fffb9SSam Ravnborg
309765c68bdSIngo Molnarconfig ARCH_SUPPORTS_OPTIMIZED_INLINING
310765c68bdSIngo Molnar	def_bool y
311765c68bdSIngo Molnar
3126a11f75bSAkinobu Mitaconfig ARCH_SUPPORTS_DEBUG_PAGEALLOC
3136a11f75bSAkinobu Mita	def_bool y
3146a11f75bSAkinobu Mita
315d6f2d75aSAndrey Ryabininconfig KASAN_SHADOW_OFFSET
316d6f2d75aSAndrey Ryabinin	hex
317d6f2d75aSAndrey Ryabinin	depends on KASAN
318d6f2d75aSAndrey Ryabinin	default 0xdffffc0000000000
319d6f2d75aSAndrey Ryabinin
32069575d38SShane Wangconfig HAVE_INTEL_TXT
32169575d38SShane Wang	def_bool y
3226ea30386SKees Cook	depends on INTEL_IOMMU && ACPI
32369575d38SShane Wang
3246b0c3d44SSam Ravnborgconfig X86_32_SMP
3256b0c3d44SSam Ravnborg	def_bool y
3266b0c3d44SSam Ravnborg	depends on X86_32 && SMP
3276b0c3d44SSam Ravnborg
3286b0c3d44SSam Ravnborgconfig X86_64_SMP
3296b0c3d44SSam Ravnborg	def_bool y
3306b0c3d44SSam Ravnborg	depends on X86_64 && SMP
3316b0c3d44SSam Ravnborg
332ccbeed3aSTejun Heoconfig X86_32_LAZY_GS
333ccbeed3aSTejun Heo	def_bool y
3348458f8c2SMasahiro Yamada	depends on X86_32 && !STACKPROTECTOR
335ccbeed3aSTejun Heo
3362b144498SSrikar Dronamrajuconfig ARCH_SUPPORTS_UPROBES
3372b144498SSrikar Dronamraju	def_bool y
3382b144498SSrikar Dronamraju
339d20642f0SRob Herringconfig FIX_EARLYCON_MEM
340d20642f0SRob Herring	def_bool y
341d20642f0SRob Herring
34294d49eb3SKirill A. Shutemovconfig DYNAMIC_PHYSICAL_MASK
34394d49eb3SKirill A. Shutemov	bool
34494d49eb3SKirill A. Shutemov
34598233368SKirill A. Shutemovconfig PGTABLE_LEVELS
34698233368SKirill A. Shutemov	int
34777ef56e4SKirill A. Shutemov	default 5 if X86_5LEVEL
34898233368SKirill A. Shutemov	default 4 if X86_64
34998233368SKirill A. Shutemov	default 3 if X86_PAE
35098233368SKirill A. Shutemov	default 2
35198233368SKirill A. Shutemov
3522a61f474SMasahiro Yamadaconfig CC_HAS_SANE_STACKPROTECTOR
3532a61f474SMasahiro Yamada	bool
3542a61f474SMasahiro Yamada	default $(success,$(srctree)/scripts/gcc-x86_64-has-stack-protector.sh $(CC)) if 64BIT
3552a61f474SMasahiro Yamada	default $(success,$(srctree)/scripts/gcc-x86_32-has-stack-protector.sh $(CC))
3562a61f474SMasahiro Yamada	help
3572a61f474SMasahiro Yamada	   We have to make sure stack protector is unconditionally disabled if
3582a61f474SMasahiro Yamada	   the compiler produces broken code.
3592a61f474SMasahiro Yamada
360506f1d07SSam Ravnborgmenu "Processor type and features"
361506f1d07SSam Ravnborg
3625ee71535SRandy Dunlapconfig ZONE_DMA
3635ee71535SRandy Dunlap	bool "DMA memory allocation support" if EXPERT
3645ee71535SRandy Dunlap	default y
3655ee71535SRandy Dunlap	help
3665ee71535SRandy Dunlap	  DMA memory allocation support allows devices with less than 32-bit
3675ee71535SRandy Dunlap	  addressing to allocate within the first 16MB of address space.
3685ee71535SRandy Dunlap	  Disable if no such devices will be used.
3695ee71535SRandy Dunlap
3705ee71535SRandy Dunlap	  If unsure, say Y.
3715ee71535SRandy Dunlap
372506f1d07SSam Ravnborgconfig SMP
373506f1d07SSam Ravnborg	bool "Symmetric multi-processing support"
374506f1d07SSam Ravnborg	---help---
375506f1d07SSam Ravnborg	  This enables support for systems with more than one CPU. If you have
3764a474157SRobert Graffham	  a system with only one CPU, say N. If you have a system with more
3774a474157SRobert Graffham	  than one CPU, say Y.
378506f1d07SSam Ravnborg
3794a474157SRobert Graffham	  If you say N here, the kernel will run on uni- and multiprocessor
380506f1d07SSam Ravnborg	  machines, but will use only one CPU of a multiprocessor machine. If
381506f1d07SSam Ravnborg	  you say Y here, the kernel will run on many, but not all,
3824a474157SRobert Graffham	  uniprocessor machines. On a uniprocessor machine, the kernel
383506f1d07SSam Ravnborg	  will run faster if you say N here.
384506f1d07SSam Ravnborg
385506f1d07SSam Ravnborg	  Note that if you say Y here and choose architecture "586" or
386506f1d07SSam Ravnborg	  "Pentium" under "Processor family", the kernel will not work on 486
387506f1d07SSam Ravnborg	  architectures. Similarly, multiprocessor kernels for the "PPro"
388506f1d07SSam Ravnborg	  architecture may not work on all Pentium based boards.
389506f1d07SSam Ravnborg
390506f1d07SSam Ravnborg	  People using multiprocessor machines who say Y here should also say
391506f1d07SSam Ravnborg	  Y to "Enhanced Real Time Clock Support", below. The "Advanced Power
392506f1d07SSam Ravnborg	  Management" code will be disabled if you say Y here.
393506f1d07SSam Ravnborg
394395cf969SPaul Bolle	  See also <file:Documentation/x86/i386/IO-APIC.txt>,
395c9525a3fSBenjamin Peterson	  <file:Documentation/lockup-watchdogs.txt> and the SMP-HOWTO available at
396506f1d07SSam Ravnborg	  <http://www.tldp.org/docs.html#howto>.
397506f1d07SSam Ravnborg
398506f1d07SSam Ravnborg	  If you don't know what to do here, say N.
399506f1d07SSam Ravnborg
4009def39beSJosh Triplettconfig X86_FEATURE_NAMES
4019def39beSJosh Triplett	bool "Processor feature human-readable names" if EMBEDDED
4029def39beSJosh Triplett	default y
4039def39beSJosh Triplett	---help---
4049def39beSJosh Triplett	  This option compiles in a table of x86 feature bits and corresponding
4059def39beSJosh Triplett	  names.  This is required to support /proc/cpuinfo and a few kernel
4069def39beSJosh Triplett	  messages.  You can disable this to save space, at the expense of
4079def39beSJosh Triplett	  making those few kernel messages show numeric feature bits instead.
4089def39beSJosh Triplett
4099def39beSJosh Triplett	  If in doubt, say Y.
4109def39beSJosh Triplett
41106cd9a7dSYinghai Luconfig X86_X2APIC
41206cd9a7dSYinghai Lu	bool "Support x2apic"
41319e3d60dSJan Kiszka	depends on X86_LOCAL_APIC && X86_64 && (IRQ_REMAP || HYPERVISOR_GUEST)
41406cd9a7dSYinghai Lu	---help---
41506cd9a7dSYinghai Lu	  This enables x2apic support on CPUs that have this feature.
41606cd9a7dSYinghai Lu
41706cd9a7dSYinghai Lu	  This allows 32-bit apic IDs (so it can support very large systems),
41806cd9a7dSYinghai Lu	  and accesses the local apic via MSRs not via mmio.
41906cd9a7dSYinghai Lu
42006cd9a7dSYinghai Lu	  If you don't know what to do here, say N.
42106cd9a7dSYinghai Lu
4226695c85bSYinghai Luconfig X86_MPPARSE
4236e87f9b7SBin Gao	bool "Enable MPS table" if ACPI || SFI
4247a527688SJan Beulich	default y
4255ab74722SIngo Molnar	depends on X86_LOCAL_APIC
4268f9ca475SIngo Molnar	---help---
4276695c85bSYinghai Lu	  For old smp systems that do not have proper acpi support. Newer systems
4286695c85bSYinghai Lu	  (esp with 64bit cpus) with acpi support, MADT and DSDT will override it
4296695c85bSYinghai Lu
430ddd70cf9SJun Nakajimaconfig GOLDFISH
431ddd70cf9SJun Nakajima       def_bool y
432ddd70cf9SJun Nakajima       depends on X86_GOLDFISH
433ddd70cf9SJun Nakajima
43476b04384SDavid Woodhouseconfig RETPOLINE
43576b04384SDavid Woodhouse	bool "Avoid speculative indirect branches in kernel"
43676b04384SDavid Woodhouse	default y
437d5028ba8SPeter Zijlstra	select STACK_VALIDATION if HAVE_STACK_VALIDATION
43876b04384SDavid Woodhouse	help
43976b04384SDavid Woodhouse	  Compile kernel with the retpoline compiler options to guard against
44076b04384SDavid Woodhouse	  kernel-to-user data leaks by avoiding speculative indirect
44176b04384SDavid Woodhouse	  branches. Requires a compiler with -mindirect-branch=thunk-extern
44276b04384SDavid Woodhouse	  support for full protection. The kernel may run slower.
44376b04384SDavid Woodhouse
444e6d42931SJohannes Weinerconfig X86_CPU_RESCTRL
445e6d42931SJohannes Weiner	bool "x86 CPU resource control support"
4466fe07ce3SBabu Moger	depends on X86 && (CPU_SUP_INTEL || CPU_SUP_AMD)
44759fe5a77SThomas Gleixner	select KERNFS
44878e99b4aSFenghua Yu	help
449e6d42931SJohannes Weiner	  Enable x86 CPU resource control support.
4506fe07ce3SBabu Moger
4516fe07ce3SBabu Moger	  Provide support for the allocation and monitoring of system resources
4526fe07ce3SBabu Moger	  usage by the CPU.
4536fe07ce3SBabu Moger
4546fe07ce3SBabu Moger	  Intel calls this Intel Resource Director Technology
4556fe07ce3SBabu Moger	  (Intel(R) RDT). More information about RDT can be found in the
4566fe07ce3SBabu Moger	  Intel x86 Architecture Software Developer Manual.
4576fe07ce3SBabu Moger
4586fe07ce3SBabu Moger	  AMD calls this AMD Platform Quality of Service (AMD QoS).
4596fe07ce3SBabu Moger	  More information about AMD QoS can be found in the AMD64 Technology
4606fe07ce3SBabu Moger	  Platform Quality of Service Extensions manual.
46178e99b4aSFenghua Yu
46278e99b4aSFenghua Yu	  Say N if unsure.
46378e99b4aSFenghua Yu
4648425091fSRavikiran G Thirumalaiif X86_32
465a0d0bb4dSRandy Dunlapconfig X86_BIGSMP
466a0d0bb4dSRandy Dunlap	bool "Support for big SMP systems with more than 8 CPUs"
467a0d0bb4dSRandy Dunlap	depends on SMP
468a0d0bb4dSRandy Dunlap	---help---
469a0d0bb4dSRandy Dunlap	  This option is needed for the systems that have more than 8 CPUs
470a0d0bb4dSRandy Dunlap
471c5c606d9SRavikiran G Thirumalaiconfig X86_EXTENDED_PLATFORM
472c5c606d9SRavikiran G Thirumalai	bool "Support for extended (non-PC) x86 platforms"
473c5c606d9SRavikiran G Thirumalai	default y
4748f9ca475SIngo Molnar	---help---
47506ac8346SIngo Molnar	  If you disable this option then the kernel will only support
47606ac8346SIngo Molnar	  standard PC platforms. (which covers the vast majority of
47706ac8346SIngo Molnar	  systems out there.)
47806ac8346SIngo Molnar
4798425091fSRavikiran G Thirumalai	  If you enable this option then you'll be able to select support
4808425091fSRavikiran G Thirumalai	  for the following (non-PC) 32 bit x86 platforms:
481cb7b8023SBen Hutchings		Goldfish (Android emulator)
4828425091fSRavikiran G Thirumalai		AMD Elan
4838425091fSRavikiran G Thirumalai		RDC R-321x SoC
4848425091fSRavikiran G Thirumalai		SGI 320/540 (Visual Workstation)
48583125a3aSAlessandro Rubini		STA2X11-based (e.g. Northville)
4863f4110a4SThomas Gleixner		Moorestown MID devices
48706ac8346SIngo Molnar
48806ac8346SIngo Molnar	  If you have one of these systems, or if you want to build a
48906ac8346SIngo Molnar	  generic distribution kernel, say Y here - otherwise say N.
4908425091fSRavikiran G Thirumalaiendif
49106ac8346SIngo Molnar
4928425091fSRavikiran G Thirumalaiif X86_64
4938425091fSRavikiran G Thirumalaiconfig X86_EXTENDED_PLATFORM
4948425091fSRavikiran G Thirumalai	bool "Support for extended (non-PC) x86 platforms"
4958425091fSRavikiran G Thirumalai	default y
4968425091fSRavikiran G Thirumalai	---help---
4978425091fSRavikiran G Thirumalai	  If you disable this option then the kernel will only support
4988425091fSRavikiran G Thirumalai	  standard PC platforms. (which covers the vast majority of
4998425091fSRavikiran G Thirumalai	  systems out there.)
5008425091fSRavikiran G Thirumalai
5018425091fSRavikiran G Thirumalai	  If you enable this option then you'll be able to select support
5028425091fSRavikiran G Thirumalai	  for the following (non-PC) 64 bit x86 platforms:
50344b111b5SSteffen Persvold		Numascale NumaChip
5048425091fSRavikiran G Thirumalai		ScaleMP vSMP
5058425091fSRavikiran G Thirumalai		SGI Ultraviolet
5068425091fSRavikiran G Thirumalai
5078425091fSRavikiran G Thirumalai	  If you have one of these systems, or if you want to build a
5088425091fSRavikiran G Thirumalai	  generic distribution kernel, say Y here - otherwise say N.
5098425091fSRavikiran G Thirumalaiendif
510c5c606d9SRavikiran G Thirumalai# This is an alphabetically sorted list of 64 bit extended platforms
511c5c606d9SRavikiran G Thirumalai# Please maintain the alphabetic order if and when there are additions
51244b111b5SSteffen Persvoldconfig X86_NUMACHIP
51344b111b5SSteffen Persvold	bool "Numascale NumaChip"
51444b111b5SSteffen Persvold	depends on X86_64
51544b111b5SSteffen Persvold	depends on X86_EXTENDED_PLATFORM
51644b111b5SSteffen Persvold	depends on NUMA
51744b111b5SSteffen Persvold	depends on SMP
51844b111b5SSteffen Persvold	depends on X86_X2APIC
519f9726bfdSDaniel J Blueman	depends on PCI_MMCONFIG
52044b111b5SSteffen Persvold	---help---
52144b111b5SSteffen Persvold	  Adds support for Numascale NumaChip large-SMP systems. Needed to
52244b111b5SSteffen Persvold	  enable more than ~168 cores.
52344b111b5SSteffen Persvold	  If you don't have one of these, you should say N here.
52403b48632SNick Piggin
5256a48565eSIngo Molnarconfig X86_VSMP
526c5c606d9SRavikiran G Thirumalai	bool "ScaleMP vSMP"
5276276a074SBorislav Petkov	select HYPERVISOR_GUEST
5286a48565eSIngo Molnar	select PARAVIRT
5296a48565eSIngo Molnar	depends on X86_64 && PCI
530c5c606d9SRavikiran G Thirumalai	depends on X86_EXTENDED_PLATFORM
531ead91d4bSShai Fultheim	depends on SMP
5328f9ca475SIngo Molnar	---help---
5336a48565eSIngo Molnar	  Support for ScaleMP vSMP systems.  Say 'Y' here if this kernel is
5346a48565eSIngo Molnar	  supposed to run on these EM64T-based machines.  Only choose this option
5356a48565eSIngo Molnar	  if you have one of these machines.
5366a48565eSIngo Molnar
537c5c606d9SRavikiran G Thirumalaiconfig X86_UV
538c5c606d9SRavikiran G Thirumalai	bool "SGI Ultraviolet"
539c5c606d9SRavikiran G Thirumalai	depends on X86_64
540c5c606d9SRavikiran G Thirumalai	depends on X86_EXTENDED_PLATFORM
54154c28d29SJack Steiner	depends on NUMA
5421ecb4ae5SAndrew Morton	depends on EFI
5439d6c26e7SSuresh Siddha	depends on X86_X2APIC
5441222e564SIngo Molnar	depends on PCI
545c5c606d9SRavikiran G Thirumalai	---help---
546c5c606d9SRavikiran G Thirumalai	  This option is needed in order to support SGI Ultraviolet systems.
547c5c606d9SRavikiran G Thirumalai	  If you don't have one of these, you should say N here.
548c5c606d9SRavikiran G Thirumalai
549c5c606d9SRavikiran G Thirumalai# Following is an alphabetically sorted list of 32 bit extended platforms
550c5c606d9SRavikiran G Thirumalai# Please maintain the alphabetic order if and when there are additions
551506f1d07SSam Ravnborg
552ddd70cf9SJun Nakajimaconfig X86_GOLDFISH
553ddd70cf9SJun Nakajima       bool "Goldfish (Virtual Platform)"
554cb7b8023SBen Hutchings       depends on X86_EXTENDED_PLATFORM
555ddd70cf9SJun Nakajima       ---help---
556ddd70cf9SJun Nakajima	 Enable support for the Goldfish virtual platform used primarily
557ddd70cf9SJun Nakajima	 for Android development. Unless you are building for the Android
558ddd70cf9SJun Nakajima	 Goldfish emulator say N here.
559ddd70cf9SJun Nakajima
560c751e17bSThomas Gleixnerconfig X86_INTEL_CE
561c751e17bSThomas Gleixner	bool "CE4100 TV platform"
562c751e17bSThomas Gleixner	depends on PCI
563c751e17bSThomas Gleixner	depends on PCI_GODIRECT
5646084a6e2SJiang Liu	depends on X86_IO_APIC
565c751e17bSThomas Gleixner	depends on X86_32
566c751e17bSThomas Gleixner	depends on X86_EXTENDED_PLATFORM
56737bc9f50SDirk Brandewie	select X86_REBOOTFIXUPS
568da6b737bSSebastian Andrzej Siewior	select OF
569da6b737bSSebastian Andrzej Siewior	select OF_EARLY_FLATTREE
570c751e17bSThomas Gleixner	---help---
571c751e17bSThomas Gleixner	  Select for the Intel CE media processor (CE4100) SOC.
572c751e17bSThomas Gleixner	  This option compiles in support for the CE4100 SOC for settop
573c751e17bSThomas Gleixner	  boxes and media devices.
574c751e17bSThomas Gleixner
5754cb9b00fSDavid Cohenconfig X86_INTEL_MID
57643605ef1SAlan Cox	bool "Intel MID platform support"
57743605ef1SAlan Cox	depends on X86_EXTENDED_PLATFORM
578edc6bc78SDavid Cohen	depends on X86_PLATFORM_DEVICES
5791ea7c673SAlan Cox	depends on PCI
5803fda5bb4SAndy Shevchenko	depends on X86_64 || (PCI_GOANY && X86_32)
5811ea7c673SAlan Cox	depends on X86_IO_APIC
5827c9c3a1eSAlan Cox	select SFI
5834cb9b00fSDavid Cohen	select I2C
5847c9c3a1eSAlan Cox	select DW_APB_TIMER
5851ea7c673SAlan Cox	select APB_TIMER
5861ea7c673SAlan Cox	select INTEL_SCU_IPC
58715a713dfSMika Westerberg	select MFD_INTEL_MSIC
5881ea7c673SAlan Cox	---help---
5894cb9b00fSDavid Cohen	  Select to build a kernel capable of supporting Intel MID (Mobile
5904cb9b00fSDavid Cohen	  Internet Device) platform systems which do not have the PCI legacy
5914cb9b00fSDavid Cohen	  interfaces. If you are building for a PC class system say N here.
5921ea7c673SAlan Cox
5934cb9b00fSDavid Cohen	  Intel MID platforms are based on an Intel processor and chipset which
5944cb9b00fSDavid Cohen	  consume less power than most of the x86 derivatives.
59543605ef1SAlan Cox
5968bbc2a13SBryan O'Donoghueconfig X86_INTEL_QUARK
5978bbc2a13SBryan O'Donoghue	bool "Intel Quark platform support"
5988bbc2a13SBryan O'Donoghue	depends on X86_32
5998bbc2a13SBryan O'Donoghue	depends on X86_EXTENDED_PLATFORM
6008bbc2a13SBryan O'Donoghue	depends on X86_PLATFORM_DEVICES
6018bbc2a13SBryan O'Donoghue	depends on X86_TSC
6028bbc2a13SBryan O'Donoghue	depends on PCI
6038bbc2a13SBryan O'Donoghue	depends on PCI_GOANY
6048bbc2a13SBryan O'Donoghue	depends on X86_IO_APIC
6058bbc2a13SBryan O'Donoghue	select IOSF_MBI
6068bbc2a13SBryan O'Donoghue	select INTEL_IMR
6079ab6eb51SAndy Shevchenko	select COMMON_CLK
6088bbc2a13SBryan O'Donoghue	---help---
6098bbc2a13SBryan O'Donoghue	  Select to include support for Quark X1000 SoC.
6108bbc2a13SBryan O'Donoghue	  Say Y here if you have a Quark based system such as the Arduino
6118bbc2a13SBryan O'Donoghue	  compatible Intel Galileo.
6128bbc2a13SBryan O'Donoghue
6133d48aab1SMika Westerbergconfig X86_INTEL_LPSS
6143d48aab1SMika Westerberg	bool "Intel Low Power Subsystem Support"
6155962dd22SSinan Kaya	depends on X86 && ACPI && PCI
6163d48aab1SMika Westerberg	select COMMON_CLK
6170f531431SMathias Nyman	select PINCTRL
618eebb3e8dSAndy Shevchenko	select IOSF_MBI
6193d48aab1SMika Westerberg	---help---
6203d48aab1SMika Westerberg	  Select to build support for Intel Low Power Subsystem such as
6213d48aab1SMika Westerberg	  found on Intel Lynxpoint PCH. Selecting this option enables
6220f531431SMathias Nyman	  things like clock tree (common clock framework) and pincontrol
6230f531431SMathias Nyman	  which are needed by the LPSS peripheral drivers.
6243d48aab1SMika Westerberg
62592082a88SKen Xueconfig X86_AMD_PLATFORM_DEVICE
62692082a88SKen Xue	bool "AMD ACPI2Platform devices support"
62792082a88SKen Xue	depends on ACPI
62892082a88SKen Xue	select COMMON_CLK
62992082a88SKen Xue	select PINCTRL
63092082a88SKen Xue	---help---
63192082a88SKen Xue	  Select to interpret AMD specific ACPI device to platform device
63292082a88SKen Xue	  such as I2C, UART, GPIO found on AMD Carrizo and later chipsets.
63392082a88SKen Xue	  I2C and UART depend on COMMON_CLK to set clock. GPIO driver is
63492082a88SKen Xue	  implemented under PINCTRL subsystem.
63592082a88SKen Xue
636ced3ce76SDavid E. Boxconfig IOSF_MBI
637ced3ce76SDavid E. Box	tristate "Intel SoC IOSF Sideband support for SoC platforms"
638ced3ce76SDavid E. Box	depends on PCI
639ced3ce76SDavid E. Box	---help---
640ced3ce76SDavid E. Box	  This option enables sideband register access support for Intel SoC
641ced3ce76SDavid E. Box	  platforms. On these platforms the IOSF sideband is used in lieu of
642ced3ce76SDavid E. Box	  MSR's for some register accesses, mostly but not limited to thermal
643ced3ce76SDavid E. Box	  and power. Drivers may query the availability of this device to
644ced3ce76SDavid E. Box	  determine if they need the sideband in order to work on these
645ced3ce76SDavid E. Box	  platforms. The sideband is available on the following SoC products.
646ced3ce76SDavid E. Box	  This list is not meant to be exclusive.
647ced3ce76SDavid E. Box	   - BayTrail
648ced3ce76SDavid E. Box	   - Braswell
649ced3ce76SDavid E. Box	   - Quark
650ced3ce76SDavid E. Box
651ced3ce76SDavid E. Box	  You should say Y if you are running a kernel on one of these SoC's.
652ced3ce76SDavid E. Box
653ed2226bdSDavid E. Boxconfig IOSF_MBI_DEBUG
654ed2226bdSDavid E. Box	bool "Enable IOSF sideband access through debugfs"
655ed2226bdSDavid E. Box	depends on IOSF_MBI && DEBUG_FS
656ed2226bdSDavid E. Box	---help---
657ed2226bdSDavid E. Box	  Select this option to expose the IOSF sideband access registers (MCR,
658ed2226bdSDavid E. Box	  MDR, MCRX) through debugfs to write and read register information from
659ed2226bdSDavid E. Box	  different units on the SoC. This is most useful for obtaining device
660ed2226bdSDavid E. Box	  state information for debug and analysis. As this is a general access
661ed2226bdSDavid E. Box	  mechanism, users of this option would have specific knowledge of the
662ed2226bdSDavid E. Box	  device they want to access.
663ed2226bdSDavid E. Box
664ed2226bdSDavid E. Box	  If you don't require the option or are in doubt, say N.
665ed2226bdSDavid E. Box
666c5c606d9SRavikiran G Thirumalaiconfig X86_RDC321X
667c5c606d9SRavikiran G Thirumalai	bool "RDC R-321x SoC"
668506f1d07SSam Ravnborg	depends on X86_32
669c5c606d9SRavikiran G Thirumalai	depends on X86_EXTENDED_PLATFORM
670c5c606d9SRavikiran G Thirumalai	select M486
671c5c606d9SRavikiran G Thirumalai	select X86_REBOOTFIXUPS
672c5c606d9SRavikiran G Thirumalai	---help---
673c5c606d9SRavikiran G Thirumalai	  This option is needed for RDC R-321x system-on-chip, also known
674c5c606d9SRavikiran G Thirumalai	  as R-8610-(G).
675c5c606d9SRavikiran G Thirumalai	  If you don't have one of these chips, you should say N here.
676c5c606d9SRavikiran G Thirumalai
677e0c7ae37SIngo Molnarconfig X86_32_NON_STANDARD
6789c398017SIngo Molnar	bool "Support non-standard 32-bit SMP architectures"
6799c398017SIngo Molnar	depends on X86_32 && SMP
680c5c606d9SRavikiran G Thirumalai	depends on X86_EXTENDED_PLATFORM
6818f9ca475SIngo Molnar	---help---
682b5660ba7SH. Peter Anvin	  This option compiles in the bigsmp and STA2X11 default
683b5660ba7SH. Peter Anvin	  subarchitectures.  It is intended for a generic binary
684b5660ba7SH. Peter Anvin	  kernel. If you select them all, kernel will probe it one by
685b5660ba7SH. Peter Anvin	  one and will fallback to default.
686d49c4288SYinghai Lu
687c5c606d9SRavikiran G Thirumalai# Alphabetically sorted list of Non standard 32 bit platforms
688d49c4288SYinghai Lu
689d949f36fSLinus Torvaldsconfig X86_SUPPORTS_MEMORY_FAILURE
6906fc108a0SJan Beulich	def_bool y
691d949f36fSLinus Torvalds	# MCE code calls memory_failure():
692d949f36fSLinus Torvalds	depends on X86_MCE
693d949f36fSLinus Torvalds	# On 32-bit this adds too big of NODES_SHIFT and we run out of page flags:
694d949f36fSLinus Torvalds	# On 32-bit SPARSEMEM adds too big of SECTIONS_WIDTH:
695d949f36fSLinus Torvalds	depends on X86_64 || !SPARSEMEM
696d949f36fSLinus Torvalds	select ARCH_SUPPORTS_MEMORY_FAILURE
697d949f36fSLinus Torvalds
69883125a3aSAlessandro Rubiniconfig STA2X11
69983125a3aSAlessandro Rubini	bool "STA2X11 Companion Chip Support"
70083125a3aSAlessandro Rubini	depends on X86_32_NON_STANDARD && PCI
701b6e05477SChristoph Hellwig	select ARCH_HAS_PHYS_TO_DMA
70283125a3aSAlessandro Rubini	select SWIOTLB
70383125a3aSAlessandro Rubini	select MFD_STA2X11
7040145071bSLinus Walleij	select GPIOLIB
70583125a3aSAlessandro Rubini	---help---
70683125a3aSAlessandro Rubini	  This adds support for boards based on the STA2X11 IO-Hub,
70783125a3aSAlessandro Rubini	  a.k.a. "ConneXt". The chip is used in place of the standard
70883125a3aSAlessandro Rubini	  PC chipset, so all "standard" peripherals are missing. If this
70983125a3aSAlessandro Rubini	  option is selected the kernel will still be able to boot on
71083125a3aSAlessandro Rubini	  standard PC machines.
71183125a3aSAlessandro Rubini
71282148d1dSShérabconfig X86_32_IRIS
71382148d1dSShérab	tristate "Eurobraille/Iris poweroff module"
71482148d1dSShérab	depends on X86_32
71582148d1dSShérab	---help---
71682148d1dSShérab	  The Iris machines from EuroBraille do not have APM or ACPI support
71782148d1dSShérab	  to shut themselves down properly.  A special I/O sequence is
71882148d1dSShérab	  needed to do so, which is what this module does at
71982148d1dSShérab	  kernel shutdown.
72082148d1dSShérab
72182148d1dSShérab	  This is only for Iris machines from EuroBraille.
72282148d1dSShérab
72382148d1dSShérab	  If unused, say N.
72482148d1dSShérab
725ae1e9130SIngo Molnarconfig SCHED_OMIT_FRAME_POINTER
7263c2362e6SHarvey Harrison	def_bool y
7273c2362e6SHarvey Harrison	prompt "Single-depth WCHAN output"
728a87d0914SKen Chen	depends on X86
7298f9ca475SIngo Molnar	---help---
730506f1d07SSam Ravnborg	  Calculate simpler /proc/<PID>/wchan values. If this option
731506f1d07SSam Ravnborg	  is disabled then wchan values will recurse back to the
732506f1d07SSam Ravnborg	  caller function. This provides more accurate wchan values,
733506f1d07SSam Ravnborg	  at the expense of slightly more scheduling overhead.
734506f1d07SSam Ravnborg
735506f1d07SSam Ravnborg	  If in doubt, say "Y".
736506f1d07SSam Ravnborg
7376276a074SBorislav Petkovmenuconfig HYPERVISOR_GUEST
7386276a074SBorislav Petkov	bool "Linux guest support"
7398f9ca475SIngo Molnar	---help---
7406276a074SBorislav Petkov	  Say Y here to enable options for running Linux under various hyper-
7416276a074SBorislav Petkov	  visors. This option enables basic hypervisor detection and platform
7426276a074SBorislav Petkov	  setup.
743506f1d07SSam Ravnborg
7446276a074SBorislav Petkov	  If you say N, all options in this submenu will be skipped and
7456276a074SBorislav Petkov	  disabled, and Linux guest support won't be built in.
746506f1d07SSam Ravnborg
7476276a074SBorislav Petkovif HYPERVISOR_GUEST
748506f1d07SSam Ravnborg
749e61bd94aSEduardo Pereira Habkostconfig PARAVIRT
750e61bd94aSEduardo Pereira Habkost	bool "Enable paravirtualization code"
7518f9ca475SIngo Molnar	---help---
752e61bd94aSEduardo Pereira Habkost	  This changes the kernel so it can modify itself when it is run
753e61bd94aSEduardo Pereira Habkost	  under a hypervisor, potentially improving performance significantly
754e61bd94aSEduardo Pereira Habkost	  over full virtualization.  However, when run without a hypervisor
755e61bd94aSEduardo Pereira Habkost	  the kernel is theoretically slower and slightly larger.
756e61bd94aSEduardo Pereira Habkost
757c00a280aSJuergen Grossconfig PARAVIRT_XXL
758c00a280aSJuergen Gross	bool
759c00a280aSJuergen Gross
7606276a074SBorislav Petkovconfig PARAVIRT_DEBUG
7616276a074SBorislav Petkov	bool "paravirt-ops debugging"
7626276a074SBorislav Petkov	depends on PARAVIRT && DEBUG_KERNEL
7636276a074SBorislav Petkov	---help---
7646276a074SBorislav Petkov	  Enable to debug paravirt_ops internals.  Specifically, BUG if
7656276a074SBorislav Petkov	  a paravirt_op is missing when it is called.
7666276a074SBorislav Petkov
767b4ecc126SJeremy Fitzhardingeconfig PARAVIRT_SPINLOCKS
768b4ecc126SJeremy Fitzhardinge	bool "Paravirtualization layer for spinlocks"
7696ea30386SKees Cook	depends on PARAVIRT && SMP
770b4ecc126SJeremy Fitzhardinge	---help---
771b4ecc126SJeremy Fitzhardinge	  Paravirtualized spinlocks allow a pvops backend to replace the
772b4ecc126SJeremy Fitzhardinge	  spinlock implementation with something virtualization-friendly
773b4ecc126SJeremy Fitzhardinge	  (for example, block the virtual CPU rather than spinning).
774b4ecc126SJeremy Fitzhardinge
7754c4e4f61SRaghavendra K T	  It has a minimal impact on native kernels and gives a nice performance
7764c4e4f61SRaghavendra K T	  benefit on paravirtualized KVM / Xen kernels.
777b4ecc126SJeremy Fitzhardinge
7784c4e4f61SRaghavendra K T	  If you are unsure how to answer this question, answer Y.
779b4ecc126SJeremy Fitzhardinge
7806276a074SBorislav Petkovsource "arch/x86/xen/Kconfig"
7816276a074SBorislav Petkov
7826276a074SBorislav Petkovconfig KVM_GUEST
7836276a074SBorislav Petkov	bool "KVM Guest support (including kvmclock)"
7846276a074SBorislav Petkov	depends on PARAVIRT
7856276a074SBorislav Petkov	select PARAVIRT_CLOCK
7866276a074SBorislav Petkov	default y
7876276a074SBorislav Petkov	---help---
7886276a074SBorislav Petkov	  This option enables various optimizations for running under the KVM
7896276a074SBorislav Petkov	  hypervisor. It includes a paravirtualized clock, so that instead
7906276a074SBorislav Petkov	  of relying on a PIT (or probably other) emulation by the
7916276a074SBorislav Petkov	  underlying device model, the host provides the guest with
7926276a074SBorislav Petkov	  timing infrastructure such as time of day, and system time
7936276a074SBorislav Petkov
7947733607fSMaran Wilsonconfig PVH
7957733607fSMaran Wilson	bool "Support for running PVH guests"
7967733607fSMaran Wilson	---help---
7977733607fSMaran Wilson	  This option enables the PVH entry point for guest virtual machines
7987733607fSMaran Wilson	  as specified in the x86/HVM direct boot ABI.
7997733607fSMaran Wilson
8001e20eb85SSrivatsa Vaddagiriconfig KVM_DEBUG_FS
8011e20eb85SSrivatsa Vaddagiri	bool "Enable debug information for KVM Guests in debugfs"
8021e20eb85SSrivatsa Vaddagiri	depends on KVM_GUEST && DEBUG_FS
8031e20eb85SSrivatsa Vaddagiri	---help---
8041e20eb85SSrivatsa Vaddagiri	  This option enables collection of various statistics for KVM guest.
8051e20eb85SSrivatsa Vaddagiri	  Statistics are displayed in debugfs filesystem. Enabling this option
8061e20eb85SSrivatsa Vaddagiri	  may incur significant overhead.
8071e20eb85SSrivatsa Vaddagiri
8086276a074SBorislav Petkovconfig PARAVIRT_TIME_ACCOUNTING
8096276a074SBorislav Petkov	bool "Paravirtual steal time accounting"
8106276a074SBorislav Petkov	depends on PARAVIRT
8116276a074SBorislav Petkov	---help---
8126276a074SBorislav Petkov	  Select this option to enable fine granularity task steal time
8136276a074SBorislav Petkov	  accounting. Time spent executing other tasks in parallel with
8146276a074SBorislav Petkov	  the current vCPU is discounted from the vCPU power. To account for
8156276a074SBorislav Petkov	  that, there can be a small performance impact.
8166276a074SBorislav Petkov
8176276a074SBorislav Petkov	  If in doubt, say N here.
8186276a074SBorislav Petkov
8197af192c9SGerd Hoffmannconfig PARAVIRT_CLOCK
8207af192c9SGerd Hoffmann	bool
8217af192c9SGerd Hoffmann
8224a362601SJan Kiszkaconfig JAILHOUSE_GUEST
8234a362601SJan Kiszka	bool "Jailhouse non-root cell support"
824abde587bSArnd Bergmann	depends on X86_64 && PCI
82587e65d05SJan Kiszka	select X86_PM_TIMER
8264a362601SJan Kiszka	---help---
8274a362601SJan Kiszka	  This option allows to run Linux as guest in a Jailhouse non-root
8284a362601SJan Kiszka	  cell. You can leave this option disabled if you only want to start
8294a362601SJan Kiszka	  Jailhouse and run Linux afterwards in the root cell.
8304a362601SJan Kiszka
8316276a074SBorislav Petkovendif #HYPERVISOR_GUEST
83297349135SJeremy Fitzhardinge
833506f1d07SSam Ravnborgsource "arch/x86/Kconfig.cpu"
834506f1d07SSam Ravnborg
835506f1d07SSam Ravnborgconfig HPET_TIMER
8363c2362e6SHarvey Harrison	def_bool X86_64
837506f1d07SSam Ravnborg	prompt "HPET Timer Support" if X86_32
8388f9ca475SIngo Molnar	---help---
839506f1d07SSam Ravnborg	  Use the IA-PC HPET (High Precision Event Timer) to manage
840506f1d07SSam Ravnborg	  time in preference to the PIT and RTC, if a HPET is
841506f1d07SSam Ravnborg	  present.
842506f1d07SSam Ravnborg	  HPET is the next generation timer replacing legacy 8254s.
843506f1d07SSam Ravnborg	  The HPET provides a stable time base on SMP
844506f1d07SSam Ravnborg	  systems, unlike the TSC, but it is more expensive to access,
8454e7f9df2SMichael S. Tsirkin	  as it is off-chip.  The interface used is documented
8464e7f9df2SMichael S. Tsirkin	  in the HPET spec, revision 1.
847506f1d07SSam Ravnborg
848506f1d07SSam Ravnborg	  You can safely choose Y here.  However, HPET will only be
849506f1d07SSam Ravnborg	  activated if the platform and the BIOS support this feature.
850506f1d07SSam Ravnborg	  Otherwise the 8254 will be used for timing services.
851506f1d07SSam Ravnborg
852506f1d07SSam Ravnborg	  Choose N to continue using the legacy 8254 timer.
853506f1d07SSam Ravnborg
854506f1d07SSam Ravnborgconfig HPET_EMULATE_RTC
8553c2362e6SHarvey Harrison	def_bool y
8569d8af78bSBernhard Walle	depends on HPET_TIMER && (RTC=y || RTC=m || RTC_DRV_CMOS=m || RTC_DRV_CMOS=y)
857506f1d07SSam Ravnborg
858bb24c471SJacob Panconfig APB_TIMER
859933b9463SAlan Cox       def_bool y if X86_INTEL_MID
860933b9463SAlan Cox       prompt "Intel MID APB Timer Support" if X86_INTEL_MID
86106c3df49SJamie Iles       select DW_APB_TIMER
862a0c3832aSAlan Cox       depends on X86_INTEL_MID && SFI
863bb24c471SJacob Pan       help
864bb24c471SJacob Pan         APB timer is the replacement for 8254, HPET on X86 MID platforms.
865bb24c471SJacob Pan         The APBT provides a stable time base on SMP
866bb24c471SJacob Pan         systems, unlike the TSC, but it is more expensive to access,
867bb24c471SJacob Pan         as it is off-chip. APB timers are always running regardless of CPU
868bb24c471SJacob Pan         C states, they are used as per CPU clockevent device when possible.
869bb24c471SJacob Pan
8706a108a14SDavid Rientjes# Mark as expert because too many people got it wrong.
871506f1d07SSam Ravnborg# The code disables itself when not needed.
8727ae9392cSThomas Petazzoniconfig DMI
8737ae9392cSThomas Petazzoni	default y
874cf074402SArd Biesheuvel	select DMI_SCAN_MACHINE_NON_EFI_FALLBACK
8756a108a14SDavid Rientjes	bool "Enable DMI scanning" if EXPERT
8768f9ca475SIngo Molnar	---help---
8777ae9392cSThomas Petazzoni	  Enabled scanning of DMI to identify machine quirks. Say Y
8787ae9392cSThomas Petazzoni	  here unless you have verified that your setup is not
8797ae9392cSThomas Petazzoni	  affected by entries in the DMI blacklist. Required by PNP
8807ae9392cSThomas Petazzoni	  BIOS code.
8817ae9392cSThomas Petazzoni
882506f1d07SSam Ravnborgconfig GART_IOMMU
88338901f1cSAndi Kleen	bool "Old AMD GART IOMMU support"
884a4ce5a48SChristoph Hellwig	select IOMMU_HELPER
885506f1d07SSam Ravnborg	select SWIOTLB
88623ac4ae8SAndreas Herrmann	depends on X86_64 && PCI && AMD_NB
8878f9ca475SIngo Molnar	---help---
888ced3c42cSIngo Molnar	  Provides a driver for older AMD Athlon64/Opteron/Turion/Sempron
889ced3c42cSIngo Molnar	  GART based hardware IOMMUs.
890ced3c42cSIngo Molnar
891ced3c42cSIngo Molnar	  The GART supports full DMA access for devices with 32-bit access
892ced3c42cSIngo Molnar	  limitations, on systems with more than 3 GB. This is usually needed
893ced3c42cSIngo Molnar	  for USB, sound, many IDE/SATA chipsets and some other devices.
894ced3c42cSIngo Molnar
895ced3c42cSIngo Molnar	  Newer systems typically have a modern AMD IOMMU, supported via
896ced3c42cSIngo Molnar	  the CONFIG_AMD_IOMMU=y config option.
897ced3c42cSIngo Molnar
898ced3c42cSIngo Molnar	  In normal configurations this driver is only active when needed:
899ced3c42cSIngo Molnar	  there's more than 3 GB of memory and the system contains a
900ced3c42cSIngo Molnar	  32-bit limited device.
901ced3c42cSIngo Molnar
902ced3c42cSIngo Molnar	  If unsure, say Y.
903506f1d07SSam Ravnborg
904506f1d07SSam Ravnborgconfig CALGARY_IOMMU
905506f1d07SSam Ravnborg	bool "IBM Calgary IOMMU support"
906a4ce5a48SChristoph Hellwig	select IOMMU_HELPER
907506f1d07SSam Ravnborg	select SWIOTLB
9086ea30386SKees Cook	depends on X86_64 && PCI
9098f9ca475SIngo Molnar	---help---
910506f1d07SSam Ravnborg	  Support for hardware IOMMUs in IBM's xSeries x366 and x460
911506f1d07SSam Ravnborg	  systems. Needed to run systems with more than 3GB of memory
912506f1d07SSam Ravnborg	  properly with 32-bit PCI devices that do not support DAC
913506f1d07SSam Ravnborg	  (Double Address Cycle). Calgary also supports bus level
914506f1d07SSam Ravnborg	  isolation, where all DMAs pass through the IOMMU.  This
915506f1d07SSam Ravnborg	  prevents them from going anywhere except their intended
916506f1d07SSam Ravnborg	  destination. This catches hard-to-find kernel bugs and
917506f1d07SSam Ravnborg	  mis-behaving drivers and devices that do not use the DMA-API
918506f1d07SSam Ravnborg	  properly to set up their DMA buffers.  The IOMMU can be
919506f1d07SSam Ravnborg	  turned off at boot time with the iommu=off parameter.
920506f1d07SSam Ravnborg	  Normally the kernel will make the right choice by itself.
921506f1d07SSam Ravnborg	  If unsure, say Y.
922506f1d07SSam Ravnborg
923506f1d07SSam Ravnborgconfig CALGARY_IOMMU_ENABLED_BY_DEFAULT
9243c2362e6SHarvey Harrison	def_bool y
9253c2362e6SHarvey Harrison	prompt "Should Calgary be enabled by default?"
926506f1d07SSam Ravnborg	depends on CALGARY_IOMMU
9278f9ca475SIngo Molnar	---help---
928506f1d07SSam Ravnborg	  Should Calgary be enabled by default? if you choose 'y', Calgary
929506f1d07SSam Ravnborg	  will be used (if it exists). If you choose 'n', Calgary will not be
930506f1d07SSam Ravnborg	  used even if it exists. If you choose 'n' and would like to use
931506f1d07SSam Ravnborg	  Calgary anyway, pass 'iommu=calgary' on the kernel command line.
932506f1d07SSam Ravnborg	  If unsure, say Y.
933506f1d07SSam Ravnborg
9341184dc2fSMike Travisconfig MAXSMP
935ddb0c5a6SSamuel Thibault	bool "Enable Maximum number of SMP Processors and NUMA Nodes"
9366ea30386SKees Cook	depends on X86_64 && SMP && DEBUG_KERNEL
93736f5101aSMike Travis	select CPUMASK_OFFSTACK
9388f9ca475SIngo Molnar	---help---
939ddb0c5a6SSamuel Thibault	  Enable maximum number of CPUS and NUMA Nodes for this architecture.
9401184dc2fSMike Travis	  If unsure, say N.
941506f1d07SSam Ravnborg
942aec6487eSIngo Molnar#
943aec6487eSIngo Molnar# The maximum number of CPUs supported:
944aec6487eSIngo Molnar#
945aec6487eSIngo Molnar# The main config value is NR_CPUS, which defaults to NR_CPUS_DEFAULT,
946aec6487eSIngo Molnar# and which can be configured interactively in the
947aec6487eSIngo Molnar# [NR_CPUS_RANGE_BEGIN ... NR_CPUS_RANGE_END] range.
948aec6487eSIngo Molnar#
949aec6487eSIngo Molnar# The ranges are different on 32-bit and 64-bit kernels, depending on
950aec6487eSIngo Molnar# hardware capabilities and scalability features of the kernel.
951aec6487eSIngo Molnar#
952aec6487eSIngo Molnar# ( If MAXSMP is enabled we just use the highest possible value and disable
953aec6487eSIngo Molnar#   interactive configuration. )
954aec6487eSIngo Molnar#
955a0d0bb4dSRandy Dunlap
956aec6487eSIngo Molnarconfig NR_CPUS_RANGE_BEGIN
957a0d0bb4dSRandy Dunlap	int
958aec6487eSIngo Molnar	default NR_CPUS_RANGE_END if MAXSMP
959a0d0bb4dSRandy Dunlap	default    1 if !SMP
960a0d0bb4dSRandy Dunlap	default    2
961a0d0bb4dSRandy Dunlap
962aec6487eSIngo Molnarconfig NR_CPUS_RANGE_END
963a0d0bb4dSRandy Dunlap	int
964a0d0bb4dSRandy Dunlap	depends on X86_32
965aec6487eSIngo Molnar	default   64 if  SMP &&  X86_BIGSMP
966aec6487eSIngo Molnar	default    8 if  SMP && !X86_BIGSMP
967a0d0bb4dSRandy Dunlap	default    1 if !SMP
968a0d0bb4dSRandy Dunlap
969aec6487eSIngo Molnarconfig NR_CPUS_RANGE_END
970a0d0bb4dSRandy Dunlap	int
971a0d0bb4dSRandy Dunlap	depends on X86_64
972aec6487eSIngo Molnar	default 8192 if  SMP && ( MAXSMP ||  CPUMASK_OFFSTACK)
973aec6487eSIngo Molnar	default  512 if  SMP && (!MAXSMP && !CPUMASK_OFFSTACK)
974a0d0bb4dSRandy Dunlap	default    1 if !SMP
975aec6487eSIngo Molnar
976aec6487eSIngo Molnarconfig NR_CPUS_DEFAULT
977aec6487eSIngo Molnar	int
978aec6487eSIngo Molnar	depends on X86_32
979aec6487eSIngo Molnar	default   32 if  X86_BIGSMP
980aec6487eSIngo Molnar	default    8 if  SMP
981aec6487eSIngo Molnar	default    1 if !SMP
982aec6487eSIngo Molnar
983aec6487eSIngo Molnarconfig NR_CPUS_DEFAULT
984aec6487eSIngo Molnar	int
985aec6487eSIngo Molnar	depends on X86_64
986a0d0bb4dSRandy Dunlap	default 8192 if  MAXSMP
987a0d0bb4dSRandy Dunlap	default   64 if  SMP
988aec6487eSIngo Molnar	default    1 if !SMP
989a0d0bb4dSRandy Dunlap
990506f1d07SSam Ravnborgconfig NR_CPUS
99136f5101aSMike Travis	int "Maximum number of CPUs" if SMP && !MAXSMP
992aec6487eSIngo Molnar	range NR_CPUS_RANGE_BEGIN NR_CPUS_RANGE_END
993aec6487eSIngo Molnar	default NR_CPUS_DEFAULT
9948f9ca475SIngo Molnar	---help---
995506f1d07SSam Ravnborg	  This allows you to specify the maximum number of CPUs which this
996bb61ccc7SJosh Boyer	  kernel will support.  If CPUMASK_OFFSTACK is enabled, the maximum
997cad14bb9SKirill A. Shutemov	  supported value is 8192, otherwise the maximum value is 512.  The
998506f1d07SSam Ravnborg	  minimum value which makes sense is 2.
999506f1d07SSam Ravnborg
1000aec6487eSIngo Molnar	  This is purely to save memory: each supported CPU adds about 8KB
1001aec6487eSIngo Molnar	  to the kernel image.
1002506f1d07SSam Ravnborg
1003506f1d07SSam Ravnborgconfig SCHED_SMT
1004dbe73364SThomas Gleixner	def_bool y if SMP
1005506f1d07SSam Ravnborg
1006506f1d07SSam Ravnborgconfig SCHED_MC
10073c2362e6SHarvey Harrison	def_bool y
10083c2362e6SHarvey Harrison	prompt "Multi-core scheduler support"
1009c8e56d20SBorislav Petkov	depends on SMP
10108f9ca475SIngo Molnar	---help---
1011506f1d07SSam Ravnborg	  Multi-core scheduler support improves the CPU scheduler's decision
1012506f1d07SSam Ravnborg	  making when dealing with multi-core CPU chips at a cost of slightly
1013506f1d07SSam Ravnborg	  increased overhead in some places. If unsure say N here.
1014506f1d07SSam Ravnborg
1015de966cf4STim Chenconfig SCHED_MC_PRIO
1016de966cf4STim Chen	bool "CPU core priorities scheduler support"
10170a21fc12SIngo Molnar	depends on SCHED_MC && CPU_SUP_INTEL
10180a21fc12SIngo Molnar	select X86_INTEL_PSTATE
10190a21fc12SIngo Molnar	select CPU_FREQ
1020de966cf4STim Chen	default y
10215e76b2abSTim Chen	---help---
1022de966cf4STim Chen	  Intel Turbo Boost Max Technology 3.0 enabled CPUs have a
1023de966cf4STim Chen	  core ordering determined at manufacturing time, which allows
1024de966cf4STim Chen	  certain cores to reach higher turbo frequencies (when running
1025de966cf4STim Chen	  single threaded workloads) than others.
1026de966cf4STim Chen
1027de966cf4STim Chen	  Enabling this kernel feature teaches the scheduler about
1028de966cf4STim Chen	  the TBM3 (aka ITMT) priority order of the CPU cores and adjusts the
1029de966cf4STim Chen	  scheduler's CPU selection logic accordingly, so that higher
1030de966cf4STim Chen	  overall system performance can be achieved.
1031de966cf4STim Chen
1032de966cf4STim Chen	  This feature will have no effect on CPUs without this feature.
1033de966cf4STim Chen
1034de966cf4STim Chen	  If unsure say Y here.
10355e76b2abSTim Chen
103630b8b006SThomas Gleixnerconfig UP_LATE_INIT
103730b8b006SThomas Gleixner       def_bool y
1038ba360f88SThomas Gleixner       depends on !SMP && X86_LOCAL_APIC
103930b8b006SThomas Gleixner
1040506f1d07SSam Ravnborgconfig X86_UP_APIC
104150849eefSJan Beulich	bool "Local APIC support on uniprocessors" if !PCI_MSI
104250849eefSJan Beulich	default PCI_MSI
104338a1dfdaSBryan O'Donoghue	depends on X86_32 && !SMP && !X86_32_NON_STANDARD
10448f9ca475SIngo Molnar	---help---
1045506f1d07SSam Ravnborg	  A local APIC (Advanced Programmable Interrupt Controller) is an
1046506f1d07SSam Ravnborg	  integrated interrupt controller in the CPU. If you have a single-CPU
1047506f1d07SSam Ravnborg	  system which has a processor with a local APIC, you can say Y here to
1048506f1d07SSam Ravnborg	  enable and use it. If you say Y here even though your machine doesn't
1049506f1d07SSam Ravnborg	  have a local APIC, then the kernel will still run with no slowdown at
1050506f1d07SSam Ravnborg	  all. The local APIC supports CPU-generated self-interrupts (timer,
1051506f1d07SSam Ravnborg	  performance counters), and the NMI watchdog which detects hard
1052506f1d07SSam Ravnborg	  lockups.
1053506f1d07SSam Ravnborg
1054506f1d07SSam Ravnborgconfig X86_UP_IOAPIC
1055506f1d07SSam Ravnborg	bool "IO-APIC support on uniprocessors"
1056506f1d07SSam Ravnborg	depends on X86_UP_APIC
10578f9ca475SIngo Molnar	---help---
1058506f1d07SSam Ravnborg	  An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an
1059506f1d07SSam Ravnborg	  SMP-capable replacement for PC-style interrupt controllers. Most
1060506f1d07SSam Ravnborg	  SMP systems and many recent uniprocessor systems have one.
1061506f1d07SSam Ravnborg
1062506f1d07SSam Ravnborg	  If you have a single-CPU system with an IO-APIC, you can say Y here
1063506f1d07SSam Ravnborg	  to use it. If you say Y here even though your machine doesn't have
1064506f1d07SSam Ravnborg	  an IO-APIC, then the kernel will still run with no slowdown at all.
1065506f1d07SSam Ravnborg
1066506f1d07SSam Ravnborgconfig X86_LOCAL_APIC
10673c2362e6SHarvey Harrison	def_bool y
10680dbc6078SThomas Petazzoni	depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC || PCI_MSI
1069b5dc8e6cSJiang Liu	select IRQ_DOMAIN_HIERARCHY
107052f518a3SJiang Liu	select PCI_MSI_IRQ_DOMAIN if PCI_MSI
1071506f1d07SSam Ravnborg
1072506f1d07SSam Ravnborgconfig X86_IO_APIC
1073b1da1e71SJan Beulich	def_bool y
1074b1da1e71SJan Beulich	depends on X86_LOCAL_APIC || X86_UP_IOAPIC
1075506f1d07SSam Ravnborg
107641b9eb26SStefan Assmannconfig X86_REROUTE_FOR_BROKEN_BOOT_IRQS
107741b9eb26SStefan Assmann	bool "Reroute for broken boot IRQs"
107841b9eb26SStefan Assmann	depends on X86_IO_APIC
10798f9ca475SIngo Molnar	---help---
108041b9eb26SStefan Assmann	  This option enables a workaround that fixes a source of
108141b9eb26SStefan Assmann	  spurious interrupts. This is recommended when threaded
108241b9eb26SStefan Assmann	  interrupt handling is used on systems where the generation of
108341b9eb26SStefan Assmann	  superfluous "boot interrupts" cannot be disabled.
108441b9eb26SStefan Assmann
108541b9eb26SStefan Assmann	  Some chipsets generate a legacy INTx "boot IRQ" when the IRQ
108641b9eb26SStefan Assmann	  entry in the chipset's IO-APIC is masked (as, e.g. the RT
108741b9eb26SStefan Assmann	  kernel does during interrupt handling). On chipsets where this
108841b9eb26SStefan Assmann	  boot IRQ generation cannot be disabled, this workaround keeps
108941b9eb26SStefan Assmann	  the original IRQ line masked so that only the equivalent "boot
109041b9eb26SStefan Assmann	  IRQ" is delivered to the CPUs. The workaround also tells the
109141b9eb26SStefan Assmann	  kernel to set up the IRQ handler on the boot IRQ line. In this
109241b9eb26SStefan Assmann	  way only one interrupt is delivered to the kernel. Otherwise
109341b9eb26SStefan Assmann	  the spurious second interrupt may cause the kernel to bring
109441b9eb26SStefan Assmann	  down (vital) interrupt lines.
109541b9eb26SStefan Assmann
109641b9eb26SStefan Assmann	  Only affects "broken" chipsets. Interrupt sharing may be
109741b9eb26SStefan Assmann	  increased on these systems.
109841b9eb26SStefan Assmann
1099506f1d07SSam Ravnborgconfig X86_MCE
1100bab9bc65SAndi Kleen	bool "Machine Check / overheating reporting"
1101648ed940SChen, Gong	select GENERIC_ALLOCATOR
1102e57dbaf7SBorislav Petkov	default y
1103506f1d07SSam Ravnborg	---help---
1104bab9bc65SAndi Kleen	  Machine Check support allows the processor to notify the
1105bab9bc65SAndi Kleen	  kernel if it detects a problem (e.g. overheating, data corruption).
1106506f1d07SSam Ravnborg	  The action the kernel takes depends on the severity of the problem,
1107bab9bc65SAndi Kleen	  ranging from warning messages to halting the machine.
11084efc0670SAndi Kleen
11095de97c9fSTony Luckconfig X86_MCELOG_LEGACY
11105de97c9fSTony Luck	bool "Support for deprecated /dev/mcelog character device"
11115de97c9fSTony Luck	depends on X86_MCE
11125de97c9fSTony Luck	---help---
11135de97c9fSTony Luck	  Enable support for /dev/mcelog which is needed by the old mcelog
11145de97c9fSTony Luck	  userspace logging daemon. Consider switching to the new generation
11155de97c9fSTony Luck	  rasdaemon solution.
11165de97c9fSTony Luck
1117506f1d07SSam Ravnborgconfig X86_MCE_INTEL
11183c2362e6SHarvey Harrison	def_bool y
11193c2362e6SHarvey Harrison	prompt "Intel MCE features"
1120c1ebf835SAndi Kleen	depends on X86_MCE && X86_LOCAL_APIC
11218f9ca475SIngo Molnar	---help---
1122506f1d07SSam Ravnborg	   Additional support for intel specific MCE features such as
1123506f1d07SSam Ravnborg	   the thermal monitor.
1124506f1d07SSam Ravnborg
1125506f1d07SSam Ravnborgconfig X86_MCE_AMD
11263c2362e6SHarvey Harrison	def_bool y
11273c2362e6SHarvey Harrison	prompt "AMD MCE features"
1128f5382de9SYazen Ghannam	depends on X86_MCE && X86_LOCAL_APIC && AMD_NB
11298f9ca475SIngo Molnar	---help---
1130506f1d07SSam Ravnborg	   Additional support for AMD specific MCE features such as
1131506f1d07SSam Ravnborg	   the DRAM Error Threshold.
1132506f1d07SSam Ravnborg
11334efc0670SAndi Kleenconfig X86_ANCIENT_MCE
11346fc108a0SJan Beulich	bool "Support for old Pentium 5 / WinChip machine checks"
1135c31d9633SAndi Kleen	depends on X86_32 && X86_MCE
11364efc0670SAndi Kleen	---help---
11374efc0670SAndi Kleen	  Include support for machine check handling on old Pentium 5 or WinChip
11385065a706SMasanari Iida	  systems. These typically need to be enabled explicitly on the command
11394efc0670SAndi Kleen	  line.
11404efc0670SAndi Kleen
1141b2762686SAndi Kleenconfig X86_MCE_THRESHOLD
1142b2762686SAndi Kleen	depends on X86_MCE_AMD || X86_MCE_INTEL
11436fc108a0SJan Beulich	def_bool y
1144b2762686SAndi Kleen
1145ea149b36SAndi Kleenconfig X86_MCE_INJECT
1146bc8e80d5SBorislav Petkov	depends on X86_MCE && X86_LOCAL_APIC && DEBUG_FS
1147ea149b36SAndi Kleen	tristate "Machine check injector support"
1148ea149b36SAndi Kleen	---help---
1149ea149b36SAndi Kleen	  Provide support for injecting machine checks for testing purposes.
1150ea149b36SAndi Kleen	  If you don't know what a machine check is and you don't do kernel
1151ea149b36SAndi Kleen	  QA it is safe to say n.
1152ea149b36SAndi Kleen
11534efc0670SAndi Kleenconfig X86_THERMAL_VECTOR
11544efc0670SAndi Kleen	def_bool y
11555bb38adcSAndi Kleen	depends on X86_MCE_INTEL
11564efc0670SAndi Kleen
115707dc900eSPeter Zijlstrasource "arch/x86/events/Kconfig"
1158e633c65aSKan Liang
11595aef51c3SAndy Lutomirskiconfig X86_LEGACY_VM86
11601e642812SIngo Molnar	bool "Legacy VM86 support"
1161506f1d07SSam Ravnborg	depends on X86_32
11628f9ca475SIngo Molnar	---help---
11635aef51c3SAndy Lutomirski	  This option allows user programs to put the CPU into V8086
11645aef51c3SAndy Lutomirski	  mode, which is an 80286-era approximation of 16-bit real mode.
11655aef51c3SAndy Lutomirski
11665aef51c3SAndy Lutomirski	  Some very old versions of X and/or vbetool require this option
11675aef51c3SAndy Lutomirski	  for user mode setting.  Similarly, DOSEMU will use it if
11685aef51c3SAndy Lutomirski	  available to accelerate real mode DOS programs.  However, any
11695aef51c3SAndy Lutomirski	  recent version of DOSEMU, X, or vbetool should be fully
11705aef51c3SAndy Lutomirski	  functional even without kernel VM86 support, as they will all
11711e642812SIngo Molnar	  fall back to software emulation. Nevertheless, if you are using
11721e642812SIngo Molnar	  a 16-bit DOS program where 16-bit performance matters, vm86
11731e642812SIngo Molnar	  mode might be faster than emulation and you might want to
11741e642812SIngo Molnar	  enable this option.
11755aef51c3SAndy Lutomirski
11761e642812SIngo Molnar	  Note that any app that works on a 64-bit kernel is unlikely to
11771e642812SIngo Molnar	  need this option, as 64-bit kernels don't, and can't, support
11781e642812SIngo Molnar	  V8086 mode. This option is also unrelated to 16-bit protected
11791e642812SIngo Molnar	  mode and is not needed to run most 16-bit programs under Wine.
11805aef51c3SAndy Lutomirski
11811e642812SIngo Molnar	  Enabling this option increases the complexity of the kernel
11821e642812SIngo Molnar	  and slows down exception handling a tiny bit.
11835aef51c3SAndy Lutomirski
11841e642812SIngo Molnar	  If unsure, say N here.
11855aef51c3SAndy Lutomirski
11865aef51c3SAndy Lutomirskiconfig VM86
11875aef51c3SAndy Lutomirski       bool
11885aef51c3SAndy Lutomirski       default X86_LEGACY_VM86
118934273f41SH. Peter Anvin
119034273f41SH. Peter Anvinconfig X86_16BIT
119134273f41SH. Peter Anvin	bool "Enable support for 16-bit segments" if EXPERT
119234273f41SH. Peter Anvin	default y
1193a5b9e5a2SAndy Lutomirski	depends on MODIFY_LDT_SYSCALL
119434273f41SH. Peter Anvin	---help---
119534273f41SH. Peter Anvin	  This option is required by programs like Wine to run 16-bit
119634273f41SH. Peter Anvin	  protected mode legacy code on x86 processors.  Disabling
119734273f41SH. Peter Anvin	  this option saves about 300 bytes on i386, or around 6K text
119834273f41SH. Peter Anvin	  plus 16K runtime memory on x86-64,
119934273f41SH. Peter Anvin
120034273f41SH. Peter Anvinconfig X86_ESPFIX32
120134273f41SH. Peter Anvin	def_bool y
120234273f41SH. Peter Anvin	depends on X86_16BIT && X86_32
1203506f1d07SSam Ravnborg
1204197725deSH. Peter Anvinconfig X86_ESPFIX64
1205197725deSH. Peter Anvin	def_bool y
120634273f41SH. Peter Anvin	depends on X86_16BIT && X86_64
1207506f1d07SSam Ravnborg
12081ad83c85SAndy Lutomirskiconfig X86_VSYSCALL_EMULATION
12091ad83c85SAndy Lutomirski       bool "Enable vsyscall emulation" if EXPERT
12101ad83c85SAndy Lutomirski       default y
12111ad83c85SAndy Lutomirski       depends on X86_64
12121ad83c85SAndy Lutomirski       ---help---
12131ad83c85SAndy Lutomirski	 This enables emulation of the legacy vsyscall page.  Disabling
12141ad83c85SAndy Lutomirski	 it is roughly equivalent to booting with vsyscall=none, except
12151ad83c85SAndy Lutomirski	 that it will also disable the helpful warning if a program
12161ad83c85SAndy Lutomirski	 tries to use a vsyscall.  With this option set to N, offending
12171ad83c85SAndy Lutomirski	 programs will just segfault, citing addresses of the form
12181ad83c85SAndy Lutomirski	 0xffffffffff600?00.
12191ad83c85SAndy Lutomirski
12201ad83c85SAndy Lutomirski	 This option is required by many programs built before 2013, and
12211ad83c85SAndy Lutomirski	 care should be used even with newer programs if set to N.
12221ad83c85SAndy Lutomirski
12231ad83c85SAndy Lutomirski	 Disabling this option saves about 7K of kernel size and
12241ad83c85SAndy Lutomirski	 possibly 4K of additional runtime pagetable memory.
12251ad83c85SAndy Lutomirski
1226506f1d07SSam Ravnborgconfig TOSHIBA
1227506f1d07SSam Ravnborg	tristate "Toshiba Laptop support"
1228506f1d07SSam Ravnborg	depends on X86_32
1229506f1d07SSam Ravnborg	---help---
1230506f1d07SSam Ravnborg	  This adds a driver to safely access the System Management Mode of
1231506f1d07SSam Ravnborg	  the CPU on Toshiba portables with a genuine Toshiba BIOS. It does
1232506f1d07SSam Ravnborg	  not work on models with a Phoenix BIOS. The System Management Mode
1233506f1d07SSam Ravnborg	  is used to set the BIOS and power saving options on Toshiba portables.
1234506f1d07SSam Ravnborg
1235506f1d07SSam Ravnborg	  For information on utilities to make use of this driver see the
1236506f1d07SSam Ravnborg	  Toshiba Linux utilities web site at:
1237506f1d07SSam Ravnborg	  <http://www.buzzard.org.uk/toshiba/>.
1238506f1d07SSam Ravnborg
1239506f1d07SSam Ravnborg	  Say Y if you intend to run this kernel on a Toshiba portable.
1240506f1d07SSam Ravnborg	  Say N otherwise.
1241506f1d07SSam Ravnborg
1242506f1d07SSam Ravnborgconfig I8K
1243039ae585SPali Rohár	tristate "Dell i8k legacy laptop support"
1244949a9d70SJean Delvare	select HWMON
1245039ae585SPali Rohár	select SENSORS_DELL_SMM
1246506f1d07SSam Ravnborg	---help---
1247039ae585SPali Rohár	  This option enables legacy /proc/i8k userspace interface in hwmon
1248039ae585SPali Rohár	  dell-smm-hwmon driver. Character file /proc/i8k reports bios version,
1249039ae585SPali Rohár	  temperature and allows controlling fan speeds of Dell laptops via
1250039ae585SPali Rohár	  System Management Mode. For old Dell laptops (like Dell Inspiron 8000)
1251039ae585SPali Rohár	  it reports also power and hotkey status. For fan speed control is
1252039ae585SPali Rohár	  needed userspace package i8kutils.
1253506f1d07SSam Ravnborg
1254039ae585SPali Rohár	  Say Y if you intend to run this kernel on old Dell laptops or want to
1255039ae585SPali Rohár	  use userspace package i8kutils.
1256506f1d07SSam Ravnborg	  Say N otherwise.
1257506f1d07SSam Ravnborg
1258506f1d07SSam Ravnborgconfig X86_REBOOTFIXUPS
12599ba16087SJan Beulich	bool "Enable X86 board specific fixups for reboot"
12609ba16087SJan Beulich	depends on X86_32
1261506f1d07SSam Ravnborg	---help---
1262506f1d07SSam Ravnborg	  This enables chipset and/or board specific fixups to be done
1263506f1d07SSam Ravnborg	  in order to get reboot to work correctly. This is only needed on
1264506f1d07SSam Ravnborg	  some combinations of hardware and BIOS. The symptom, for which
1265506f1d07SSam Ravnborg	  this config is intended, is when reboot ends with a stalled/hung
1266506f1d07SSam Ravnborg	  system.
1267506f1d07SSam Ravnborg
1268506f1d07SSam Ravnborg	  Currently, the only fixup is for the Geode machines using
12695e3a77e9SFlorian Fainelli	  CS5530A and CS5536 chipsets and the RDC R-321x SoC.
1270506f1d07SSam Ravnborg
1271506f1d07SSam Ravnborg	  Say Y if you want to enable the fixup. Currently, it's safe to
1272506f1d07SSam Ravnborg	  enable this option even if you don't need it.
1273506f1d07SSam Ravnborg	  Say N otherwise.
1274506f1d07SSam Ravnborg
1275506f1d07SSam Ravnborgconfig MICROCODE
12769a2bc335SBorislav Petkov	bool "CPU microcode loading support"
12779a2bc335SBorislav Petkov	default y
127880030e3dSBorislav Petkov	depends on CPU_SUP_AMD || CPU_SUP_INTEL
1279506f1d07SSam Ravnborg	select FW_LOADER
1280506f1d07SSam Ravnborg	---help---
1281506f1d07SSam Ravnborg	  If you say Y here, you will be able to update the microcode on
12825f9c01aaSBorislav Petkov	  Intel and AMD processors. The Intel support is for the IA32 family,
12835f9c01aaSBorislav Petkov	  e.g. Pentium Pro, Pentium II, Pentium III, Pentium 4, Xeon etc. The
12845f9c01aaSBorislav Petkov	  AMD support is for families 0x10 and later. You will obviously need
12855f9c01aaSBorislav Petkov	  the actual microcode binary data itself which is not shipped with
12865f9c01aaSBorislav Petkov	  the Linux kernel.
1287506f1d07SSam Ravnborg
12885f9c01aaSBorislav Petkov	  The preferred method to load microcode from a detached initrd is described
12891897a969SJaak Ristioja	  in Documentation/x86/microcode.txt. For that you need to enable
12905f9c01aaSBorislav Petkov	  CONFIG_BLK_DEV_INITRD in order for the loader to be able to scan the
12915f9c01aaSBorislav Petkov	  initrd for microcode blobs.
1292506f1d07SSam Ravnborg
1293c508c46eSBenjamin Gilbert	  In addition, you can build the microcode into the kernel. For that you
1294c508c46eSBenjamin Gilbert	  need to add the vendor-supplied microcode to the CONFIG_EXTRA_FIRMWARE
1295c508c46eSBenjamin Gilbert	  config option.
1296506f1d07SSam Ravnborg
12978d86f390SPeter Orubaconfig MICROCODE_INTEL
1298e43f6e67SBorislav Petkov	bool "Intel microcode loading support"
12998d86f390SPeter Oruba	depends on MICROCODE
13008d86f390SPeter Oruba	default MICROCODE
13018d86f390SPeter Oruba	select FW_LOADER
13028f9ca475SIngo Molnar	---help---
13038d86f390SPeter Oruba	  This options enables microcode patch loading support for Intel
13048d86f390SPeter Oruba	  processors.
13058d86f390SPeter Oruba
1306b8989db9SAlan	  For the current Intel microcode data package go to
1307b8989db9SAlan	  <https://downloadcenter.intel.com> and search for
1308b8989db9SAlan	  'Linux Processor Microcode Data File'.
13098d86f390SPeter Oruba
131080cc9f10SPeter Orubaconfig MICROCODE_AMD
1311e43f6e67SBorislav Petkov	bool "AMD microcode loading support"
131280cc9f10SPeter Oruba	depends on MICROCODE
131380cc9f10SPeter Oruba	select FW_LOADER
13148f9ca475SIngo Molnar	---help---
131580cc9f10SPeter Oruba	  If you select this option, microcode patch loading support for AMD
131680cc9f10SPeter Oruba	  processors will be enabled.
131780cc9f10SPeter Oruba
1318506f1d07SSam Ravnborgconfig MICROCODE_OLD_INTERFACE
1319c02f48e0SBorislav Petkov	bool "Ancient loading interface (DEPRECATED)"
1320c02f48e0SBorislav Petkov	default n
1321506f1d07SSam Ravnborg	depends on MICROCODE
1322c02f48e0SBorislav Petkov	---help---
1323c02f48e0SBorislav Petkov	  DO NOT USE THIS! This is the ancient /dev/cpu/microcode interface
1324c02f48e0SBorislav Petkov	  which was used by userspace tools like iucode_tool and microcode.ctl.
1325c02f48e0SBorislav Petkov	  It is inadequate because it runs too late to be able to properly
1326c02f48e0SBorislav Petkov	  load microcode on a machine and it needs special tools. Instead, you
1327c02f48e0SBorislav Petkov	  should've switched to the early loading method with the initrd or
1328c02f48e0SBorislav Petkov	  builtin microcode by now: Documentation/x86/microcode.txt
1329506f1d07SSam Ravnborg
1330506f1d07SSam Ravnborgconfig X86_MSR
1331506f1d07SSam Ravnborg	tristate "/dev/cpu/*/msr - Model-specific register support"
13328f9ca475SIngo Molnar	---help---
1333506f1d07SSam Ravnborg	  This device gives privileged processes access to the x86
1334506f1d07SSam Ravnborg	  Model-Specific Registers (MSRs).  It is a character device with
1335506f1d07SSam Ravnborg	  major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr.
1336506f1d07SSam Ravnborg	  MSR accesses are directed to a specific CPU on multi-processor
1337506f1d07SSam Ravnborg	  systems.
1338506f1d07SSam Ravnborg
1339506f1d07SSam Ravnborgconfig X86_CPUID
1340506f1d07SSam Ravnborg	tristate "/dev/cpu/*/cpuid - CPU information support"
13418f9ca475SIngo Molnar	---help---
1342506f1d07SSam Ravnborg	  This device gives processes access to the x86 CPUID instruction to
1343506f1d07SSam Ravnborg	  be executed on a specific processor.  It is a character device
1344506f1d07SSam Ravnborg	  with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to
1345506f1d07SSam Ravnborg	  /dev/cpu/31/cpuid.
1346506f1d07SSam Ravnborg
1347506f1d07SSam Ravnborgchoice
1348506f1d07SSam Ravnborg	prompt "High Memory Support"
13496fc108a0SJan Beulich	default HIGHMEM4G
1350506f1d07SSam Ravnborg	depends on X86_32
1351506f1d07SSam Ravnborg
1352506f1d07SSam Ravnborgconfig NOHIGHMEM
1353506f1d07SSam Ravnborg	bool "off"
1354506f1d07SSam Ravnborg	---help---
1355506f1d07SSam Ravnborg	  Linux can use up to 64 Gigabytes of physical memory on x86 systems.
1356506f1d07SSam Ravnborg	  However, the address space of 32-bit x86 processors is only 4
1357506f1d07SSam Ravnborg	  Gigabytes large. That means that, if you have a large amount of
1358506f1d07SSam Ravnborg	  physical memory, not all of it can be "permanently mapped" by the
1359506f1d07SSam Ravnborg	  kernel. The physical memory that's not permanently mapped is called
1360506f1d07SSam Ravnborg	  "high memory".
1361506f1d07SSam Ravnborg
1362506f1d07SSam Ravnborg	  If you are compiling a kernel which will never run on a machine with
1363506f1d07SSam Ravnborg	  more than 1 Gigabyte total physical RAM, answer "off" here (default
1364506f1d07SSam Ravnborg	  choice and suitable for most users). This will result in a "3GB/1GB"
1365506f1d07SSam Ravnborg	  split: 3GB are mapped so that each process sees a 3GB virtual memory
1366506f1d07SSam Ravnborg	  space and the remaining part of the 4GB virtual memory space is used
1367506f1d07SSam Ravnborg	  by the kernel to permanently map as much physical memory as
1368506f1d07SSam Ravnborg	  possible.
1369506f1d07SSam Ravnborg
1370506f1d07SSam Ravnborg	  If the machine has between 1 and 4 Gigabytes physical RAM, then
1371506f1d07SSam Ravnborg	  answer "4GB" here.
1372506f1d07SSam Ravnborg
1373506f1d07SSam Ravnborg	  If more than 4 Gigabytes is used then answer "64GB" here. This
1374506f1d07SSam Ravnborg	  selection turns Intel PAE (Physical Address Extension) mode on.
1375506f1d07SSam Ravnborg	  PAE implements 3-level paging on IA32 processors. PAE is fully
1376506f1d07SSam Ravnborg	  supported by Linux, PAE mode is implemented on all recent Intel
1377506f1d07SSam Ravnborg	  processors (Pentium Pro and better). NOTE: If you say "64GB" here,
1378506f1d07SSam Ravnborg	  then the kernel will not boot on CPUs that don't support PAE!
1379506f1d07SSam Ravnborg
1380506f1d07SSam Ravnborg	  The actual amount of total physical memory will either be
1381506f1d07SSam Ravnborg	  auto detected or can be forced by using a kernel command line option
1382506f1d07SSam Ravnborg	  such as "mem=256M". (Try "man bootparam" or see the documentation of
1383506f1d07SSam Ravnborg	  your boot loader (lilo or loadlin) about how to pass options to the
1384506f1d07SSam Ravnborg	  kernel at boot time.)
1385506f1d07SSam Ravnborg
1386506f1d07SSam Ravnborg	  If unsure, say "off".
1387506f1d07SSam Ravnborg
1388506f1d07SSam Ravnborgconfig HIGHMEM4G
1389506f1d07SSam Ravnborg	bool "4GB"
13908f9ca475SIngo Molnar	---help---
1391506f1d07SSam Ravnborg	  Select this if you have a 32-bit processor and between 1 and 4
1392506f1d07SSam Ravnborg	  gigabytes of physical RAM.
1393506f1d07SSam Ravnborg
1394506f1d07SSam Ravnborgconfig HIGHMEM64G
1395506f1d07SSam Ravnborg	bool "64GB"
139669b8d3fcSMatthew Whitehead	depends on !M486 && !M586 && !M586TSC && !M586MMX && !MGEODE_LX && !MGEODEGX1 && !MCYRIXIII && !MELAN && !MWINCHIPC6 && !WINCHIP3D && !MK6
1397506f1d07SSam Ravnborg	select X86_PAE
13988f9ca475SIngo Molnar	---help---
1399506f1d07SSam Ravnborg	  Select this if you have a 32-bit processor and more than 4
1400506f1d07SSam Ravnborg	  gigabytes of physical RAM.
1401506f1d07SSam Ravnborg
1402506f1d07SSam Ravnborgendchoice
1403506f1d07SSam Ravnborg
1404506f1d07SSam Ravnborgchoice
14056a108a14SDavid Rientjes	prompt "Memory split" if EXPERT
1406506f1d07SSam Ravnborg	default VMSPLIT_3G
1407506f1d07SSam Ravnborg	depends on X86_32
14088f9ca475SIngo Molnar	---help---
1409506f1d07SSam Ravnborg	  Select the desired split between kernel and user memory.
1410506f1d07SSam Ravnborg
1411506f1d07SSam Ravnborg	  If the address range available to the kernel is less than the
1412506f1d07SSam Ravnborg	  physical memory installed, the remaining memory will be available
1413506f1d07SSam Ravnborg	  as "high memory". Accessing high memory is a little more costly
1414506f1d07SSam Ravnborg	  than low memory, as it needs to be mapped into the kernel first.
1415506f1d07SSam Ravnborg	  Note that increasing the kernel address space limits the range
1416506f1d07SSam Ravnborg	  available to user programs, making the address space there
1417506f1d07SSam Ravnborg	  tighter.  Selecting anything other than the default 3G/1G split
1418506f1d07SSam Ravnborg	  will also likely make your kernel incompatible with binary-only
1419506f1d07SSam Ravnborg	  kernel modules.
1420506f1d07SSam Ravnborg
1421506f1d07SSam Ravnborg	  If you are not absolutely sure what you are doing, leave this
1422506f1d07SSam Ravnborg	  option alone!
1423506f1d07SSam Ravnborg
1424506f1d07SSam Ravnborg	config VMSPLIT_3G
1425506f1d07SSam Ravnborg		bool "3G/1G user/kernel split"
1426506f1d07SSam Ravnborg	config VMSPLIT_3G_OPT
1427506f1d07SSam Ravnborg		depends on !X86_PAE
1428506f1d07SSam Ravnborg		bool "3G/1G user/kernel split (for full 1G low memory)"
1429506f1d07SSam Ravnborg	config VMSPLIT_2G
1430506f1d07SSam Ravnborg		bool "2G/2G user/kernel split"
1431506f1d07SSam Ravnborg	config VMSPLIT_2G_OPT
1432506f1d07SSam Ravnborg		depends on !X86_PAE
1433506f1d07SSam Ravnborg		bool "2G/2G user/kernel split (for full 2G low memory)"
1434506f1d07SSam Ravnborg	config VMSPLIT_1G
1435506f1d07SSam Ravnborg		bool "1G/3G user/kernel split"
1436506f1d07SSam Ravnborgendchoice
1437506f1d07SSam Ravnborg
1438506f1d07SSam Ravnborgconfig PAGE_OFFSET
1439506f1d07SSam Ravnborg	hex
1440506f1d07SSam Ravnborg	default 0xB0000000 if VMSPLIT_3G_OPT
1441506f1d07SSam Ravnborg	default 0x80000000 if VMSPLIT_2G
1442506f1d07SSam Ravnborg	default 0x78000000 if VMSPLIT_2G_OPT
1443506f1d07SSam Ravnborg	default 0x40000000 if VMSPLIT_1G
1444506f1d07SSam Ravnborg	default 0xC0000000
1445506f1d07SSam Ravnborg	depends on X86_32
1446506f1d07SSam Ravnborg
1447506f1d07SSam Ravnborgconfig HIGHMEM
14483c2362e6SHarvey Harrison	def_bool y
1449506f1d07SSam Ravnborg	depends on X86_32 && (HIGHMEM64G || HIGHMEM4G)
1450506f1d07SSam Ravnborg
1451506f1d07SSam Ravnborgconfig X86_PAE
14529ba16087SJan Beulich	bool "PAE (Physical Address Extension) Support"
1453506f1d07SSam Ravnborg	depends on X86_32 && !HIGHMEM4G
1454d4a451d5SChristoph Hellwig	select PHYS_ADDR_T_64BIT
14559d99c712SChristian Melki	select SWIOTLB
14568f9ca475SIngo Molnar	---help---
1457506f1d07SSam Ravnborg	  PAE is required for NX support, and furthermore enables
1458506f1d07SSam Ravnborg	  larger swapspace support for non-overcommit purposes. It
1459506f1d07SSam Ravnborg	  has the cost of more pagetable lookup overhead, and also
1460506f1d07SSam Ravnborg	  consumes more pagetable space per process.
1461506f1d07SSam Ravnborg
146277ef56e4SKirill A. Shutemovconfig X86_5LEVEL
146377ef56e4SKirill A. Shutemov	bool "Enable 5-level page tables support"
1464eedb92abSKirill A. Shutemov	select DYNAMIC_MEMORY_LAYOUT
1465162434e7SKirill A. Shutemov	select SPARSEMEM_VMEMMAP
146677ef56e4SKirill A. Shutemov	depends on X86_64
146777ef56e4SKirill A. Shutemov	---help---
146877ef56e4SKirill A. Shutemov	  5-level paging enables access to larger address space:
146977ef56e4SKirill A. Shutemov	  upto 128 PiB of virtual address space and 4 PiB of
147077ef56e4SKirill A. Shutemov	  physical address space.
147177ef56e4SKirill A. Shutemov
147277ef56e4SKirill A. Shutemov	  It will be supported by future Intel CPUs.
147377ef56e4SKirill A. Shutemov
14746657fca0SKirill A. Shutemov	  A kernel with the option enabled can be booted on machines that
14756657fca0SKirill A. Shutemov	  support 4- or 5-level paging.
147677ef56e4SKirill A. Shutemov
147777ef56e4SKirill A. Shutemov	  See Documentation/x86/x86_64/5level-paging.txt for more
147877ef56e4SKirill A. Shutemov	  information.
147977ef56e4SKirill A. Shutemov
148077ef56e4SKirill A. Shutemov	  Say N if unsure.
148177ef56e4SKirill A. Shutemov
148210971ab2SIngo Molnarconfig X86_DIRECT_GBPAGES
1483e5008abeSLuis R. Rodriguez	def_bool y
14844675ff05SLevin, Alexander (Sasha Levin)	depends on X86_64 && !DEBUG_PAGEALLOC
14858f9ca475SIngo Molnar	---help---
148610971ab2SIngo Molnar	  Certain kernel features effectively disable kernel
148710971ab2SIngo Molnar	  linear 1 GB mappings (even if the CPU otherwise
148810971ab2SIngo Molnar	  supports them), so don't confuse the user by printing
148910971ab2SIngo Molnar	  that we have them enabled.
14909e899816SNick Piggin
14915c280cf6SThomas Gleixnerconfig X86_CPA_STATISTICS
14925c280cf6SThomas Gleixner	bool "Enable statistic for Change Page Attribute"
14935c280cf6SThomas Gleixner	depends on DEBUG_FS
14945c280cf6SThomas Gleixner	---help---
14955c280cf6SThomas Gleixner	  Expose statistics about the Change Page Attribute mechanims, which
1496a943245aSColin Ian King	  helps to determine the effectiveness of preserving large and huge
14975c280cf6SThomas Gleixner	  page mappings when mapping protections are changed.
14985c280cf6SThomas Gleixner
14997744ccdbSTom Lendackyconfig ARCH_HAS_MEM_ENCRYPT
15007744ccdbSTom Lendacky	def_bool y
15017744ccdbSTom Lendacky
15027744ccdbSTom Lendackyconfig AMD_MEM_ENCRYPT
15037744ccdbSTom Lendacky	bool "AMD Secure Memory Encryption (SME) support"
15047744ccdbSTom Lendacky	depends on X86_64 && CPU_SUP_AMD
150594d49eb3SKirill A. Shutemov	select DYNAMIC_PHYSICAL_MASK
1506ce9084baSArd Biesheuvel	select ARCH_USE_MEMREMAP_PROT
15077744ccdbSTom Lendacky	---help---
15087744ccdbSTom Lendacky	  Say yes to enable support for the encryption of system memory.
15097744ccdbSTom Lendacky	  This requires an AMD processor that supports Secure Memory
15107744ccdbSTom Lendacky	  Encryption (SME).
15117744ccdbSTom Lendacky
15127744ccdbSTom Lendackyconfig AMD_MEM_ENCRYPT_ACTIVE_BY_DEFAULT
15137744ccdbSTom Lendacky	bool "Activate AMD Secure Memory Encryption (SME) by default"
15147744ccdbSTom Lendacky	default y
15157744ccdbSTom Lendacky	depends on AMD_MEM_ENCRYPT
15167744ccdbSTom Lendacky	---help---
15177744ccdbSTom Lendacky	  Say yes to have system memory encrypted by default if running on
15187744ccdbSTom Lendacky	  an AMD processor that supports Secure Memory Encryption (SME).
15197744ccdbSTom Lendacky
15207744ccdbSTom Lendacky	  If set to Y, then the encryption of system memory can be
15217744ccdbSTom Lendacky	  deactivated with the mem_encrypt=off command line option.
15227744ccdbSTom Lendacky
15237744ccdbSTom Lendacky	  If set to N, then the encryption of system memory can be
15247744ccdbSTom Lendacky	  activated with the mem_encrypt=on command line option.
15257744ccdbSTom Lendacky
1526506f1d07SSam Ravnborg# Common NUMA Features
1527506f1d07SSam Ravnborgconfig NUMA
1528fd51b2d7SKOSAKI Motohiro	bool "Numa Memory Allocation and Scheduler Support"
1529506f1d07SSam Ravnborg	depends on SMP
1530b5660ba7SH. Peter Anvin	depends on X86_64 || (X86_32 && HIGHMEM64G && X86_BIGSMP)
1531b5660ba7SH. Peter Anvin	default y if X86_BIGSMP
15328f9ca475SIngo Molnar	---help---
1533506f1d07SSam Ravnborg	  Enable NUMA (Non Uniform Memory Access) support.
1534fd51b2d7SKOSAKI Motohiro
1535506f1d07SSam Ravnborg	  The kernel will try to allocate memory used by a CPU on the
1536506f1d07SSam Ravnborg	  local memory controller of the CPU and add some more
1537506f1d07SSam Ravnborg	  NUMA awareness to the kernel.
1538506f1d07SSam Ravnborg
1539c280ea5eSIngo Molnar	  For 64-bit this is recommended if the system is Intel Core i7
1540fd51b2d7SKOSAKI Motohiro	  (or later), AMD Opteron, or EM64T NUMA.
1541fd51b2d7SKOSAKI Motohiro
1542b5660ba7SH. Peter Anvin	  For 32-bit this is only needed if you boot a 32-bit
15437cf6c945SDavid Rientjes	  kernel on a 64-bit NUMA platform.
1544fd51b2d7SKOSAKI Motohiro
1545fd51b2d7SKOSAKI Motohiro	  Otherwise, you should say N.
1546506f1d07SSam Ravnborg
1547eec1d4faSHans Rosenfeldconfig AMD_NUMA
15483c2362e6SHarvey Harrison	def_bool y
15493c2362e6SHarvey Harrison	prompt "Old style AMD Opteron NUMA detection"
15505da0ef9aSTejun Heo	depends on X86_64 && NUMA && PCI
15518f9ca475SIngo Molnar	---help---
1552eec1d4faSHans Rosenfeld	  Enable AMD NUMA node topology detection.  You should say Y here if
1553eec1d4faSHans Rosenfeld	  you have a multi processor AMD system. This uses an old method to
1554eec1d4faSHans Rosenfeld	  read the NUMA configuration directly from the builtin Northbridge
1555eec1d4faSHans Rosenfeld	  of Opteron. It is recommended to use X86_64_ACPI_NUMA instead,
1556eec1d4faSHans Rosenfeld	  which also takes priority if both are compiled in.
1557506f1d07SSam Ravnborg
1558506f1d07SSam Ravnborgconfig X86_64_ACPI_NUMA
15593c2362e6SHarvey Harrison	def_bool y
15603c2362e6SHarvey Harrison	prompt "ACPI NUMA detection"
1561506f1d07SSam Ravnborg	depends on X86_64 && NUMA && ACPI && PCI
1562506f1d07SSam Ravnborg	select ACPI_NUMA
15638f9ca475SIngo Molnar	---help---
1564506f1d07SSam Ravnborg	  Enable ACPI SRAT based node topology detection.
1565506f1d07SSam Ravnborg
15666ec6e0d9SSuresh Siddha# Some NUMA nodes have memory ranges that span
15676ec6e0d9SSuresh Siddha# other nodes.  Even though a pfn is valid and
15686ec6e0d9SSuresh Siddha# between a node's start and end pfns, it may not
15696ec6e0d9SSuresh Siddha# reside on that node.  See memmap_init_zone()
15706ec6e0d9SSuresh Siddha# for details.
15716ec6e0d9SSuresh Siddhaconfig NODES_SPAN_OTHER_NODES
15726ec6e0d9SSuresh Siddha	def_bool y
15736ec6e0d9SSuresh Siddha	depends on X86_64_ACPI_NUMA
15746ec6e0d9SSuresh Siddha
1575506f1d07SSam Ravnborgconfig NUMA_EMU
1576506f1d07SSam Ravnborg	bool "NUMA emulation"
15771b7e03efSTejun Heo	depends on NUMA
15788f9ca475SIngo Molnar	---help---
1579506f1d07SSam Ravnborg	  Enable NUMA emulation. A flat machine will be split
1580506f1d07SSam Ravnborg	  into virtual nodes when booted with "numa=fake=N", where N is the
1581506f1d07SSam Ravnborg	  number of nodes. This is only useful for debugging.
1582506f1d07SSam Ravnborg
1583506f1d07SSam Ravnborgconfig NODES_SHIFT
1584d25e26b6SLinus Torvalds	int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP
158551591e31SDavid Rientjes	range 1 10
158651591e31SDavid Rientjes	default "10" if MAXSMP
1587506f1d07SSam Ravnborg	default "6" if X86_64
1588506f1d07SSam Ravnborg	default "3"
1589506f1d07SSam Ravnborg	depends on NEED_MULTIPLE_NODES
15908f9ca475SIngo Molnar	---help---
15911184dc2fSMike Travis	  Specify the maximum number of NUMA Nodes available on the target
1592692105b8SMatt LaPlante	  system.  Increases memory reserved to accommodate various tables.
1593506f1d07SSam Ravnborg
1594506f1d07SSam Ravnborgconfig ARCH_HAVE_MEMORY_PRESENT
15953c2362e6SHarvey Harrison	def_bool y
1596506f1d07SSam Ravnborg	depends on X86_32 && DISCONTIGMEM
1597506f1d07SSam Ravnborg
1598506f1d07SSam Ravnborgconfig ARCH_FLATMEM_ENABLE
1599506f1d07SSam Ravnborg	def_bool y
16003b16651fSTejun Heo	depends on X86_32 && !NUMA
1601506f1d07SSam Ravnborg
1602506f1d07SSam Ravnborgconfig ARCH_DISCONTIGMEM_ENABLE
16032792107dSMike Rapoport	def_bool n
1604b263295dSChristoph Lameter	depends on NUMA && X86_32
16052792107dSMike Rapoport	depends on BROKEN
1606b263295dSChristoph Lameter
1607506f1d07SSam Ravnborgconfig ARCH_SPARSEMEM_ENABLE
1608506f1d07SSam Ravnborg	def_bool y
16096ea30386SKees Cook	depends on X86_64 || NUMA || X86_32 || X86_32_NON_STANDARD
1610506f1d07SSam Ravnborg	select SPARSEMEM_STATIC if X86_32
1611506f1d07SSam Ravnborg	select SPARSEMEM_VMEMMAP_ENABLE if X86_64
1612506f1d07SSam Ravnborg
16133b16651fSTejun Heoconfig ARCH_SPARSEMEM_DEFAULT
16146ad57f7fSMike Rapoport	def_bool X86_64 || (NUMA && X86_32)
16153b16651fSTejun Heo
1616506f1d07SSam Ravnborgconfig ARCH_SELECT_MEMORY_MODEL
1617506f1d07SSam Ravnborg	def_bool y
1618b263295dSChristoph Lameter	depends on ARCH_SPARSEMEM_ENABLE
1619506f1d07SSam Ravnborg
1620506f1d07SSam Ravnborgconfig ARCH_MEMORY_PROBE
1621a0842b70SToshi Kani	bool "Enable sysfs memory/probe interface"
16223120e25eSJan Beulich	depends on X86_64 && MEMORY_HOTPLUG
1623a0842b70SToshi Kani	help
1624a0842b70SToshi Kani	  This option enables a sysfs memory/probe interface for testing.
1625a0842b70SToshi Kani	  See Documentation/memory-hotplug.txt for more information.
1626a0842b70SToshi Kani	  If you are unsure how to answer this question, answer N.
1627506f1d07SSam Ravnborg
16283b16651fSTejun Heoconfig ARCH_PROC_KCORE_TEXT
16293b16651fSTejun Heo	def_bool y
16303b16651fSTejun Heo	depends on X86_64 && PROC_KCORE
16313b16651fSTejun Heo
1632a29815a3SAvi Kivityconfig ILLEGAL_POINTER_VALUE
1633a29815a3SAvi Kivity       hex
1634a29815a3SAvi Kivity       default 0 if X86_32
1635a29815a3SAvi Kivity       default 0xdead000000000000 if X86_64
1636a29815a3SAvi Kivity
16377a67832cSDan Williamsconfig X86_PMEM_LEGACY_DEVICE
16387a67832cSDan Williams	bool
16397a67832cSDan Williams
1640ec776ef6SChristoph Hellwigconfig X86_PMEM_LEGACY
16417a67832cSDan Williams	tristate "Support non-standard NVDIMMs and ADR protected memory"
16429f53f9faSDan Williams	depends on PHYS_ADDR_T_64BIT
16439f53f9faSDan Williams	depends on BLK_DEV
16447a67832cSDan Williams	select X86_PMEM_LEGACY_DEVICE
16459f53f9faSDan Williams	select LIBNVDIMM
1646ec776ef6SChristoph Hellwig	help
1647ec776ef6SChristoph Hellwig	  Treat memory marked using the non-standard e820 type of 12 as used
1648ec776ef6SChristoph Hellwig	  by the Intel Sandy Bridge-EP reference BIOS as protected memory.
1649ec776ef6SChristoph Hellwig	  The kernel will offer these regions to the 'pmem' driver so
1650ec776ef6SChristoph Hellwig	  they can be used for persistent storage.
1651ec776ef6SChristoph Hellwig
1652ec776ef6SChristoph Hellwig	  Say Y if unsure.
1653ec776ef6SChristoph Hellwig
1654506f1d07SSam Ravnborgconfig HIGHPTE
1655506f1d07SSam Ravnborg	bool "Allocate 3rd-level pagetables from highmem"
16566fc108a0SJan Beulich	depends on HIGHMEM
16578f9ca475SIngo Molnar	---help---
1658506f1d07SSam Ravnborg	  The VM uses one page table entry for each page of physical memory.
1659506f1d07SSam Ravnborg	  For systems with a lot of RAM, this can be wasteful of precious
1660506f1d07SSam Ravnborg	  low memory.  Setting this option will put user-space page table
1661506f1d07SSam Ravnborg	  entries in high memory.
1662506f1d07SSam Ravnborg
16639f077871SJeremy Fitzhardingeconfig X86_CHECK_BIOS_CORRUPTION
16649f077871SJeremy Fitzhardinge	bool "Check for low memory corruption"
16658f9ca475SIngo Molnar	---help---
16669f077871SJeremy Fitzhardinge	  Periodically check for memory corruption in low memory, which
16679f077871SJeremy Fitzhardinge	  is suspected to be caused by BIOS.  Even when enabled in the
16689f077871SJeremy Fitzhardinge	  configuration, it is disabled at runtime.  Enable it by
16699f077871SJeremy Fitzhardinge	  setting "memory_corruption_check=1" on the kernel command
16709f077871SJeremy Fitzhardinge	  line.  By default it scans the low 64k of memory every 60
16719f077871SJeremy Fitzhardinge	  seconds; see the memory_corruption_check_size and
16729f077871SJeremy Fitzhardinge	  memory_corruption_check_period parameters in
16738c27ceffSMauro Carvalho Chehab	  Documentation/admin-guide/kernel-parameters.rst to adjust this.
16749f077871SJeremy Fitzhardinge
16759f077871SJeremy Fitzhardinge	  When enabled with the default parameters, this option has
16769f077871SJeremy Fitzhardinge	  almost no overhead, as it reserves a relatively small amount
16779f077871SJeremy Fitzhardinge	  of memory and scans it infrequently.  It both detects corruption
16789f077871SJeremy Fitzhardinge	  and prevents it from affecting the running system.
16799f077871SJeremy Fitzhardinge
16809f077871SJeremy Fitzhardinge	  It is, however, intended as a diagnostic tool; if repeatable
16819f077871SJeremy Fitzhardinge	  BIOS-originated corruption always affects the same memory,
16829f077871SJeremy Fitzhardinge	  you can use memmap= to prevent the kernel from using that
16839f077871SJeremy Fitzhardinge	  memory.
16849f077871SJeremy Fitzhardinge
1685c885df50SJeremy Fitzhardingeconfig X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK
1686c885df50SJeremy Fitzhardinge	bool "Set the default setting of memory_corruption_check"
1687c885df50SJeremy Fitzhardinge	depends on X86_CHECK_BIOS_CORRUPTION
1688c885df50SJeremy Fitzhardinge	default y
16898f9ca475SIngo Molnar	---help---
1690c885df50SJeremy Fitzhardinge	  Set whether the default state of memory_corruption_check is
1691c885df50SJeremy Fitzhardinge	  on or off.
1692c885df50SJeremy Fitzhardinge
16939ea77bdbSH. Peter Anvinconfig X86_RESERVE_LOW
1694d0cd7425SH. Peter Anvin	int "Amount of low memory, in kilobytes, to reserve for the BIOS"
1695d0cd7425SH. Peter Anvin	default 64
1696d0cd7425SH. Peter Anvin	range 4 640
16978f9ca475SIngo Molnar	---help---
1698d0cd7425SH. Peter Anvin	  Specify the amount of low memory to reserve for the BIOS.
1699fc381519SIngo Molnar
1700d0cd7425SH. Peter Anvin	  The first page contains BIOS data structures that the kernel
1701d0cd7425SH. Peter Anvin	  must not use, so that page must always be reserved.
1702fc381519SIngo Molnar
1703d0cd7425SH. Peter Anvin	  By default we reserve the first 64K of physical RAM, as a
1704d0cd7425SH. Peter Anvin	  number of BIOSes are known to corrupt that memory range
1705d0cd7425SH. Peter Anvin	  during events such as suspend/resume or monitor cable
1706d0cd7425SH. Peter Anvin	  insertion, so it must not be used by the kernel.
1707fc381519SIngo Molnar
1708d0cd7425SH. Peter Anvin	  You can set this to 4 if you are absolutely sure that you
1709d0cd7425SH. Peter Anvin	  trust the BIOS to get all its memory reservations and usages
1710d0cd7425SH. Peter Anvin	  right.  If you know your BIOS have problems beyond the
1711d0cd7425SH. Peter Anvin	  default 64K area, you can set this to 640 to avoid using the
1712d0cd7425SH. Peter Anvin	  entire low memory range.
1713d0cd7425SH. Peter Anvin
1714d0cd7425SH. Peter Anvin	  If you have doubts about the BIOS (e.g. suspend/resume does
1715d0cd7425SH. Peter Anvin	  not work or there's kernel crashes after certain hardware
1716d0cd7425SH. Peter Anvin	  hotplug events) then you might want to enable
1717d0cd7425SH. Peter Anvin	  X86_CHECK_BIOS_CORRUPTION=y to allow the kernel to check
1718d0cd7425SH. Peter Anvin	  typical corruption patterns.
1719d0cd7425SH. Peter Anvin
1720d0cd7425SH. Peter Anvin	  Leave this to the default value of 64 if you are unsure.
1721fc381519SIngo Molnar
1722506f1d07SSam Ravnborgconfig MATH_EMULATION
1723506f1d07SSam Ravnborg	bool
1724a5b9e5a2SAndy Lutomirski	depends on MODIFY_LDT_SYSCALL
1725506f1d07SSam Ravnborg	prompt "Math emulation" if X86_32
1726506f1d07SSam Ravnborg	---help---
1727506f1d07SSam Ravnborg	  Linux can emulate a math coprocessor (used for floating point
1728506f1d07SSam Ravnborg	  operations) if you don't have one. 486DX and Pentium processors have
1729506f1d07SSam Ravnborg	  a math coprocessor built in, 486SX and 386 do not, unless you added
1730506f1d07SSam Ravnborg	  a 487DX or 387, respectively. (The messages during boot time can
1731506f1d07SSam Ravnborg	  give you some hints here ["man dmesg"].) Everyone needs either a
1732506f1d07SSam Ravnborg	  coprocessor or this emulation.
1733506f1d07SSam Ravnborg
1734506f1d07SSam Ravnborg	  If you don't have a math coprocessor, you need to say Y here; if you
1735506f1d07SSam Ravnborg	  say Y here even though you have a coprocessor, the coprocessor will
1736506f1d07SSam Ravnborg	  be used nevertheless. (This behavior can be changed with the kernel
1737506f1d07SSam Ravnborg	  command line option "no387", which comes handy if your coprocessor
1738506f1d07SSam Ravnborg	  is broken. Try "man bootparam" or see the documentation of your boot
1739506f1d07SSam Ravnborg	  loader (lilo or loadlin) about how to pass options to the kernel at
1740506f1d07SSam Ravnborg	  boot time.) This means that it is a good idea to say Y here if you
1741506f1d07SSam Ravnborg	  intend to use this kernel on different machines.
1742506f1d07SSam Ravnborg
1743506f1d07SSam Ravnborg	  More information about the internals of the Linux math coprocessor
1744506f1d07SSam Ravnborg	  emulation can be found in <file:arch/x86/math-emu/README>.
1745506f1d07SSam Ravnborg
1746506f1d07SSam Ravnborg	  If you are not sure, say Y; apart from resulting in a 66 KB bigger
1747506f1d07SSam Ravnborg	  kernel, it won't hurt.
1748506f1d07SSam Ravnborg
1749506f1d07SSam Ravnborgconfig MTRR
17506fc108a0SJan Beulich	def_bool y
17516a108a14SDavid Rientjes	prompt "MTRR (Memory Type Range Register) support" if EXPERT
1752506f1d07SSam Ravnborg	---help---
1753506f1d07SSam Ravnborg	  On Intel P6 family processors (Pentium Pro, Pentium II and later)
1754506f1d07SSam Ravnborg	  the Memory Type Range Registers (MTRRs) may be used to control
1755506f1d07SSam Ravnborg	  processor access to memory ranges. This is most useful if you have
1756506f1d07SSam Ravnborg	  a video (VGA) card on a PCI or AGP bus. Enabling write-combining
1757506f1d07SSam Ravnborg	  allows bus write transfers to be combined into a larger transfer
1758506f1d07SSam Ravnborg	  before bursting over the PCI/AGP bus. This can increase performance
1759506f1d07SSam Ravnborg	  of image write operations 2.5 times or more. Saying Y here creates a
1760506f1d07SSam Ravnborg	  /proc/mtrr file which may be used to manipulate your processor's
1761506f1d07SSam Ravnborg	  MTRRs. Typically the X server should use this.
1762506f1d07SSam Ravnborg
1763506f1d07SSam Ravnborg	  This code has a reasonably generic interface so that similar
1764506f1d07SSam Ravnborg	  control registers on other processors can be easily supported
1765506f1d07SSam Ravnborg	  as well:
1766506f1d07SSam Ravnborg
1767506f1d07SSam Ravnborg	  The Cyrix 6x86, 6x86MX and M II processors have Address Range
1768506f1d07SSam Ravnborg	  Registers (ARRs) which provide a similar functionality to MTRRs. For
1769506f1d07SSam Ravnborg	  these, the ARRs are used to emulate the MTRRs.
1770506f1d07SSam Ravnborg	  The AMD K6-2 (stepping 8 and above) and K6-3 processors have two
1771506f1d07SSam Ravnborg	  MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing
1772506f1d07SSam Ravnborg	  write-combining. All of these processors are supported by this code
1773506f1d07SSam Ravnborg	  and it makes sense to say Y here if you have one of them.
1774506f1d07SSam Ravnborg
1775506f1d07SSam Ravnborg	  Saying Y here also fixes a problem with buggy SMP BIOSes which only
1776506f1d07SSam Ravnborg	  set the MTRRs for the boot CPU and not for the secondary CPUs. This
1777506f1d07SSam Ravnborg	  can lead to all sorts of problems, so it's good to say Y here.
1778506f1d07SSam Ravnborg
1779506f1d07SSam Ravnborg	  You can safely say Y even if your machine doesn't have MTRRs, you'll
1780506f1d07SSam Ravnborg	  just add about 9 KB to your kernel.
1781506f1d07SSam Ravnborg
17827225e751SRandy Dunlap	  See <file:Documentation/x86/mtrr.txt> for more information.
1783506f1d07SSam Ravnborg
178495ffa243SYinghai Luconfig MTRR_SANITIZER
17852ffb3501SYinghai Lu	def_bool y
178695ffa243SYinghai Lu	prompt "MTRR cleanup support"
178795ffa243SYinghai Lu	depends on MTRR
17888f9ca475SIngo Molnar	---help---
1789aba3728cSThomas Gleixner	  Convert MTRR layout from continuous to discrete, so X drivers can
1790aba3728cSThomas Gleixner	  add writeback entries.
179195ffa243SYinghai Lu
1792aba3728cSThomas Gleixner	  Can be disabled with disable_mtrr_cleanup on the kernel command line.
1793692105b8SMatt LaPlante	  The largest mtrr entry size for a continuous block can be set with
1794aba3728cSThomas Gleixner	  mtrr_chunk_size.
179595ffa243SYinghai Lu
17962ffb3501SYinghai Lu	  If unsure, say Y.
179795ffa243SYinghai Lu
179895ffa243SYinghai Luconfig MTRR_SANITIZER_ENABLE_DEFAULT
1799f5098d62SYinghai Lu	int "MTRR cleanup enable value (0-1)"
1800f5098d62SYinghai Lu	range 0 1
1801f5098d62SYinghai Lu	default "0"
180295ffa243SYinghai Lu	depends on MTRR_SANITIZER
18038f9ca475SIngo Molnar	---help---
1804f5098d62SYinghai Lu	  Enable mtrr cleanup default value
180595ffa243SYinghai Lu
180612031a62SYinghai Luconfig MTRR_SANITIZER_SPARE_REG_NR_DEFAULT
180712031a62SYinghai Lu	int "MTRR cleanup spare reg num (0-7)"
180812031a62SYinghai Lu	range 0 7
180912031a62SYinghai Lu	default "1"
181012031a62SYinghai Lu	depends on MTRR_SANITIZER
18118f9ca475SIngo Molnar	---help---
181212031a62SYinghai Lu	  mtrr cleanup spare entries default, it can be changed via
1813aba3728cSThomas Gleixner	  mtrr_spare_reg_nr=N on the kernel command line.
181412031a62SYinghai Lu
18152e5d9c85Svenkatesh.pallipadi@intel.comconfig X86_PAT
18166fc108a0SJan Beulich	def_bool y
18176a108a14SDavid Rientjes	prompt "x86 PAT support" if EXPERT
18182a8a2719SIngo Molnar	depends on MTRR
18198f9ca475SIngo Molnar	---help---
18202e5d9c85Svenkatesh.pallipadi@intel.com	  Use PAT attributes to setup page level cache control.
1821042b78e4SVenki Pallipadi
18222e5d9c85Svenkatesh.pallipadi@intel.com	  PATs are the modern equivalents of MTRRs and are much more
18232e5d9c85Svenkatesh.pallipadi@intel.com	  flexible than MTRRs.
18242e5d9c85Svenkatesh.pallipadi@intel.com
18252e5d9c85Svenkatesh.pallipadi@intel.com	  Say N here if you see bootup problems (boot crash, boot hang,
1826042b78e4SVenki Pallipadi	  spontaneous reboots) or a non-working video driver.
18272e5d9c85Svenkatesh.pallipadi@intel.com
18282e5d9c85Svenkatesh.pallipadi@intel.com	  If unsure, say Y.
18292e5d9c85Svenkatesh.pallipadi@intel.com
183046cf98cdSVenkatesh Pallipadiconfig ARCH_USES_PG_UNCACHED
183146cf98cdSVenkatesh Pallipadi	def_bool y
183246cf98cdSVenkatesh Pallipadi	depends on X86_PAT
183346cf98cdSVenkatesh Pallipadi
1834628c6246SH. Peter Anvinconfig ARCH_RANDOM
1835628c6246SH. Peter Anvin	def_bool y
1836628c6246SH. Peter Anvin	prompt "x86 architectural random number generator" if EXPERT
1837628c6246SH. Peter Anvin	---help---
1838628c6246SH. Peter Anvin	  Enable the x86 architectural RDRAND instruction
1839628c6246SH. Peter Anvin	  (Intel Bull Mountain technology) to generate random numbers.
1840628c6246SH. Peter Anvin	  If supported, this is a high bandwidth, cryptographically
1841628c6246SH. Peter Anvin	  secure hardware random number generator.
1842628c6246SH. Peter Anvin
184351ae4a2dSH. Peter Anvinconfig X86_SMAP
184451ae4a2dSH. Peter Anvin	def_bool y
184551ae4a2dSH. Peter Anvin	prompt "Supervisor Mode Access Prevention" if EXPERT
184651ae4a2dSH. Peter Anvin	---help---
184751ae4a2dSH. Peter Anvin	  Supervisor Mode Access Prevention (SMAP) is a security
184851ae4a2dSH. Peter Anvin	  feature in newer Intel processors.  There is a small
184951ae4a2dSH. Peter Anvin	  performance cost if this enabled and turned on; there is
185051ae4a2dSH. Peter Anvin	  also a small increase in the kernel size if this is enabled.
185151ae4a2dSH. Peter Anvin
185251ae4a2dSH. Peter Anvin	  If unsure, say Y.
185351ae4a2dSH. Peter Anvin
1854aa35f896SRicardo Nericonfig X86_INTEL_UMIP
1855796ebc81SRicardo Neri	def_bool y
1856aa35f896SRicardo Neri	depends on CPU_SUP_INTEL
1857aa35f896SRicardo Neri	prompt "Intel User Mode Instruction Prevention" if EXPERT
1858aa35f896SRicardo Neri	---help---
1859aa35f896SRicardo Neri	  The User Mode Instruction Prevention (UMIP) is a security
1860aa35f896SRicardo Neri	  feature in newer Intel processors. If enabled, a general
1861796ebc81SRicardo Neri	  protection fault is issued if the SGDT, SLDT, SIDT, SMSW
1862796ebc81SRicardo Neri	  or STR instructions are executed in user mode. These instructions
1863796ebc81SRicardo Neri	  unnecessarily expose information about the hardware state.
1864796ebc81SRicardo Neri
1865796ebc81SRicardo Neri	  The vast majority of applications do not use these instructions.
1866796ebc81SRicardo Neri	  For the very few that do, software emulation is provided in
1867796ebc81SRicardo Neri	  specific cases in protected and virtual-8086 modes. Emulated
1868796ebc81SRicardo Neri	  results are dummy.
1869aa35f896SRicardo Neri
187072e9b5feSDave Hansenconfig X86_INTEL_MPX
187172e9b5feSDave Hansen	prompt "Intel MPX (Memory Protection Extensions)"
187272e9b5feSDave Hansen	def_bool n
1873df3735c5SRik van Riel	# Note: only available in 64-bit mode due to VMA flags shortage
1874df3735c5SRik van Riel	depends on CPU_SUP_INTEL && X86_64
1875df3735c5SRik van Riel	select ARCH_USES_HIGH_VMA_FLAGS
187672e9b5feSDave Hansen	---help---
187772e9b5feSDave Hansen	  MPX provides hardware features that can be used in
187872e9b5feSDave Hansen	  conjunction with compiler-instrumented code to check
187972e9b5feSDave Hansen	  memory references.  It is designed to detect buffer
188072e9b5feSDave Hansen	  overflow or underflow bugs.
188172e9b5feSDave Hansen
188272e9b5feSDave Hansen	  This option enables running applications which are
188372e9b5feSDave Hansen	  instrumented or otherwise use MPX.  It does not use MPX
188472e9b5feSDave Hansen	  itself inside the kernel or to protect the kernel
188572e9b5feSDave Hansen	  against bad memory references.
188672e9b5feSDave Hansen
188772e9b5feSDave Hansen	  Enabling this option will make the kernel larger:
188872e9b5feSDave Hansen	  ~8k of kernel text and 36 bytes of data on a 64-bit
188972e9b5feSDave Hansen	  defconfig.  It adds a long to the 'mm_struct' which
189072e9b5feSDave Hansen	  will increase the kernel memory overhead of each
189172e9b5feSDave Hansen	  process and adds some branches to paths used during
189272e9b5feSDave Hansen	  exec() and munmap().
189372e9b5feSDave Hansen
189472e9b5feSDave Hansen	  For details, see Documentation/x86/intel_mpx.txt
189572e9b5feSDave Hansen
189672e9b5feSDave Hansen	  If unsure, say N.
189772e9b5feSDave Hansen
189835e97790SDave Hansenconfig X86_INTEL_MEMORY_PROTECTION_KEYS
1899284244a9SDave Hansen	prompt "Intel Memory Protection Keys"
190035e97790SDave Hansen	def_bool y
1901284244a9SDave Hansen	# Note: only available in 64-bit mode
190235e97790SDave Hansen	depends on CPU_SUP_INTEL && X86_64
190352c8e601SIngo Molnar	select ARCH_USES_HIGH_VMA_FLAGS
190452c8e601SIngo Molnar	select ARCH_HAS_PKEYS
1905284244a9SDave Hansen	---help---
1906284244a9SDave Hansen	  Memory Protection Keys provides a mechanism for enforcing
1907284244a9SDave Hansen	  page-based protections, but without requiring modification of the
1908284244a9SDave Hansen	  page tables when an application changes protection domains.
1909284244a9SDave Hansen
1910284244a9SDave Hansen	  For details, see Documentation/x86/protection-keys.txt
1911284244a9SDave Hansen
1912284244a9SDave Hansen	  If unsure, say y.
191335e97790SDave Hansen
1914506f1d07SSam Ravnborgconfig EFI
19159ba16087SJan Beulich	bool "EFI runtime service support"
19165b83683fSHuang, Ying	depends on ACPI
1917f6ce5002SSergey Vlasov	select UCS2_STRING
1918022ee6c5SArd Biesheuvel	select EFI_RUNTIME_WRAPPERS
1919506f1d07SSam Ravnborg	---help---
19208b2cb7a8SHuang, Ying	  This enables the kernel to use EFI runtime services that are
1921506f1d07SSam Ravnborg	  available (such as the EFI variable services).
1922506f1d07SSam Ravnborg
19238b2cb7a8SHuang, Ying	  This option is only useful on systems that have EFI firmware.
19248b2cb7a8SHuang, Ying	  In addition, you should use the latest ELILO loader available
19258b2cb7a8SHuang, Ying	  at <http://elilo.sourceforge.net> in order to take advantage
19268b2cb7a8SHuang, Ying	  of EFI runtime services. However, even with this option, the
19278b2cb7a8SHuang, Ying	  resultant kernel should continue to boot on existing non-EFI
19288b2cb7a8SHuang, Ying	  platforms.
1929506f1d07SSam Ravnborg
1930291f3632SMatt Flemingconfig EFI_STUB
1931291f3632SMatt Fleming       bool "EFI stub support"
1932b16d8c23SMatt Fleming       depends on EFI && !X86_USE_3DNOW
19337b2a583aSMatt Fleming       select RELOCATABLE
1934291f3632SMatt Fleming       ---help---
1935291f3632SMatt Fleming          This kernel feature allows a bzImage to be loaded directly
1936291f3632SMatt Fleming	  by EFI firmware without the use of a bootloader.
1937291f3632SMatt Fleming
19384172fe2fSRoy Franz	  See Documentation/efi-stub.txt for more information.
19390c759662SMatt Fleming
19407d453eeeSMatt Flemingconfig EFI_MIXED
19417d453eeeSMatt Fleming	bool "EFI mixed-mode support"
19427d453eeeSMatt Fleming	depends on EFI_STUB && X86_64
19437d453eeeSMatt Fleming	---help---
19447d453eeeSMatt Fleming	   Enabling this feature allows a 64-bit kernel to be booted
19457d453eeeSMatt Fleming	   on a 32-bit firmware, provided that your CPU supports 64-bit
19467d453eeeSMatt Fleming	   mode.
19477d453eeeSMatt Fleming
19487d453eeeSMatt Fleming	   Note that it is not possible to boot a mixed-mode enabled
19497d453eeeSMatt Fleming	   kernel via the EFI boot stub - a bootloader that supports
19507d453eeeSMatt Fleming	   the EFI handover protocol must be used.
19517d453eeeSMatt Fleming
19527d453eeeSMatt Fleming	   If unsure, say N.
19537d453eeeSMatt Fleming
1954506f1d07SSam Ravnborgconfig SECCOMP
19553c2362e6SHarvey Harrison	def_bool y
19563c2362e6SHarvey Harrison	prompt "Enable seccomp to safely compute untrusted bytecode"
19578f9ca475SIngo Molnar	---help---
1958506f1d07SSam Ravnborg	  This kernel feature is useful for number crunching applications
1959506f1d07SSam Ravnborg	  that may need to compute untrusted bytecode during their
1960506f1d07SSam Ravnborg	  execution. By using pipes or other transports made available to
1961506f1d07SSam Ravnborg	  the process as file descriptors supporting the read/write
1962506f1d07SSam Ravnborg	  syscalls, it's possible to isolate those applications in
1963506f1d07SSam Ravnborg	  their own address space using seccomp. Once seccomp is
19649c0bbee8SAlexey Dobriyan	  enabled via prctl(PR_SET_SECCOMP), it cannot be disabled
1965506f1d07SSam Ravnborg	  and the task is only allowed to execute a few safe syscalls
1966506f1d07SSam Ravnborg	  defined by each seccomp mode.
1967506f1d07SSam Ravnborg
1968506f1d07SSam Ravnborg	  If unsure, say Y. Only embedded should say N here.
1969506f1d07SSam Ravnborg
19708636a1f9SMasahiro Yamadasource "kernel/Kconfig.hz"
1971506f1d07SSam Ravnborg
1972506f1d07SSam Ravnborgconfig KEXEC
1973506f1d07SSam Ravnborg	bool "kexec system call"
19742965faa5SDave Young	select KEXEC_CORE
19758f9ca475SIngo Molnar	---help---
1976506f1d07SSam Ravnborg	  kexec is a system call that implements the ability to shutdown your
1977506f1d07SSam Ravnborg	  current kernel, and to start another kernel.  It is like a reboot
1978506f1d07SSam Ravnborg	  but it is independent of the system firmware.   And like a reboot
1979506f1d07SSam Ravnborg	  you can start any kernel with it, not just Linux.
1980506f1d07SSam Ravnborg
1981506f1d07SSam Ravnborg	  The name comes from the similarity to the exec system call.
1982506f1d07SSam Ravnborg
1983506f1d07SSam Ravnborg	  It is an ongoing process to be certain the hardware in a machine
1984506f1d07SSam Ravnborg	  is properly shutdown, so do not be surprised if this code does not
1985bf220695SGeert Uytterhoeven	  initially work for you.  As of this writing the exact hardware
1986bf220695SGeert Uytterhoeven	  interface is strongly in flux, so no good recommendation can be
1987bf220695SGeert Uytterhoeven	  made.
1988506f1d07SSam Ravnborg
198974ca317cSVivek Goyalconfig KEXEC_FILE
199074ca317cSVivek Goyal	bool "kexec file based system call"
19912965faa5SDave Young	select KEXEC_CORE
199274ca317cSVivek Goyal	select BUILD_BIN2C
199374ca317cSVivek Goyal	depends on X86_64
199474ca317cSVivek Goyal	depends on CRYPTO=y
199574ca317cSVivek Goyal	depends on CRYPTO_SHA256=y
199674ca317cSVivek Goyal	---help---
199774ca317cSVivek Goyal	  This is new version of kexec system call. This system call is
199874ca317cSVivek Goyal	  file based and takes file descriptors as system call argument
199974ca317cSVivek Goyal	  for kernel and initramfs as opposed to list of segments as
200074ca317cSVivek Goyal	  accepted by previous system call.
200174ca317cSVivek Goyal
2002b799a09fSAKASHI Takahiroconfig ARCH_HAS_KEXEC_PURGATORY
2003b799a09fSAKASHI Takahiro	def_bool KEXEC_FILE
2004b799a09fSAKASHI Takahiro
20058e7d8381SVivek Goyalconfig KEXEC_VERIFY_SIG
20068e7d8381SVivek Goyal	bool "Verify kernel signature during kexec_file_load() syscall"
200774ca317cSVivek Goyal	depends on KEXEC_FILE
20088e7d8381SVivek Goyal	---help---
20098e7d8381SVivek Goyal	  This option makes kernel signature verification mandatory for
2010d8eb8940SBorislav Petkov	  the kexec_file_load() syscall.
20118e7d8381SVivek Goyal
2012d8eb8940SBorislav Petkov	  In addition to that option, you need to enable signature
2013d8eb8940SBorislav Petkov	  verification for the corresponding kernel image type being
2014d8eb8940SBorislav Petkov	  loaded in order for this to work.
20158e7d8381SVivek Goyal
20168e7d8381SVivek Goyalconfig KEXEC_BZIMAGE_VERIFY_SIG
20178e7d8381SVivek Goyal	bool "Enable bzImage signature verification support"
20188e7d8381SVivek Goyal	depends on KEXEC_VERIFY_SIG
20198e7d8381SVivek Goyal	depends on SIGNED_PE_FILE_VERIFICATION
20208e7d8381SVivek Goyal	select SYSTEM_TRUSTED_KEYRING
20218e7d8381SVivek Goyal	---help---
20228e7d8381SVivek Goyal	  Enable bzImage signature verification support.
20238e7d8381SVivek Goyal
2024506f1d07SSam Ravnborgconfig CRASH_DUMP
202504b69447SPavel Machek	bool "kernel crash dumps"
2026506f1d07SSam Ravnborg	depends on X86_64 || (X86_32 && HIGHMEM)
20278f9ca475SIngo Molnar	---help---
2028506f1d07SSam Ravnborg	  Generate crash dump after being started by kexec.
2029506f1d07SSam Ravnborg	  This should be normally only set in special crash dump kernels
2030506f1d07SSam Ravnborg	  which are loaded in the main kernel with kexec-tools into
2031506f1d07SSam Ravnborg	  a specially reserved region and then later executed after
2032506f1d07SSam Ravnborg	  a crash by kdump/kexec. The crash dump kernel must be compiled
2033506f1d07SSam Ravnborg	  to a memory address not used by the main kernel or BIOS using
2034506f1d07SSam Ravnborg	  PHYSICAL_START, or it must be built as a relocatable image
2035506f1d07SSam Ravnborg	  (CONFIG_RELOCATABLE=y).
2036506f1d07SSam Ravnborg	  For more details see Documentation/kdump/kdump.txt
2037506f1d07SSam Ravnborg
20383ab83521SHuang Yingconfig KEXEC_JUMP
20396ea30386SKees Cook	bool "kexec jump"
2040fee7b0d8SHuang Ying	depends on KEXEC && HIBERNATION
20418f9ca475SIngo Molnar	---help---
204289081d17SHuang Ying	  Jump between original kernel and kexeced kernel and invoke
204389081d17SHuang Ying	  code in physical address mode via KEXEC
20443ab83521SHuang Ying
2045506f1d07SSam Ravnborgconfig PHYSICAL_START
20466a108a14SDavid Rientjes	hex "Physical address where the kernel is loaded" if (EXPERT || CRASH_DUMP)
2047ceefccc9SH. Peter Anvin	default "0x1000000"
20488f9ca475SIngo Molnar	---help---
2049506f1d07SSam Ravnborg	  This gives the physical address where the kernel is loaded.
2050506f1d07SSam Ravnborg
2051506f1d07SSam Ravnborg	  If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then
2052506f1d07SSam Ravnborg	  bzImage will decompress itself to above physical address and
2053506f1d07SSam Ravnborg	  run from there. Otherwise, bzImage will run from the address where
2054506f1d07SSam Ravnborg	  it has been loaded by the boot loader and will ignore above physical
2055506f1d07SSam Ravnborg	  address.
2056506f1d07SSam Ravnborg
2057506f1d07SSam Ravnborg	  In normal kdump cases one does not have to set/change this option
2058506f1d07SSam Ravnborg	  as now bzImage can be compiled as a completely relocatable image
2059506f1d07SSam Ravnborg	  (CONFIG_RELOCATABLE=y) and be used to load and run from a different
2060506f1d07SSam Ravnborg	  address. This option is mainly useful for the folks who don't want
2061506f1d07SSam Ravnborg	  to use a bzImage for capturing the crash dump and want to use a
2062506f1d07SSam Ravnborg	  vmlinux instead. vmlinux is not relocatable hence a kernel needs
2063506f1d07SSam Ravnborg	  to be specifically compiled to run from a specific memory area
2064506f1d07SSam Ravnborg	  (normally a reserved region) and this option comes handy.
2065506f1d07SSam Ravnborg
2066ceefccc9SH. Peter Anvin	  So if you are using bzImage for capturing the crash dump,
2067ceefccc9SH. Peter Anvin	  leave the value here unchanged to 0x1000000 and set
2068ceefccc9SH. Peter Anvin	  CONFIG_RELOCATABLE=y.  Otherwise if you plan to use vmlinux
2069ceefccc9SH. Peter Anvin	  for capturing the crash dump change this value to start of
2070ceefccc9SH. Peter Anvin	  the reserved region.  In other words, it can be set based on
2071ceefccc9SH. Peter Anvin	  the "X" value as specified in the "crashkernel=YM@XM"
2072ceefccc9SH. Peter Anvin	  command line boot parameter passed to the panic-ed
2073ceefccc9SH. Peter Anvin	  kernel. Please take a look at Documentation/kdump/kdump.txt
2074ceefccc9SH. Peter Anvin	  for more details about crash dumps.
2075506f1d07SSam Ravnborg
2076506f1d07SSam Ravnborg	  Usage of bzImage for capturing the crash dump is recommended as
2077506f1d07SSam Ravnborg	  one does not have to build two kernels. Same kernel can be used
2078506f1d07SSam Ravnborg	  as production kernel and capture kernel. Above option should have
2079506f1d07SSam Ravnborg	  gone away after relocatable bzImage support is introduced. But it
2080506f1d07SSam Ravnborg	  is present because there are users out there who continue to use
2081506f1d07SSam Ravnborg	  vmlinux for dump capture. This option should go away down the
2082506f1d07SSam Ravnborg	  line.
2083506f1d07SSam Ravnborg
2084506f1d07SSam Ravnborg	  Don't change this unless you know what you are doing.
2085506f1d07SSam Ravnborg
2086506f1d07SSam Ravnborgconfig RELOCATABLE
208726717808SH. Peter Anvin	bool "Build a relocatable kernel"
208826717808SH. Peter Anvin	default y
20898f9ca475SIngo Molnar	---help---
2090506f1d07SSam Ravnborg	  This builds a kernel image that retains relocation information
2091506f1d07SSam Ravnborg	  so it can be loaded someplace besides the default 1MB.
2092506f1d07SSam Ravnborg	  The relocations tend to make the kernel binary about 10% larger,
2093506f1d07SSam Ravnborg	  but are discarded at runtime.
2094506f1d07SSam Ravnborg
2095506f1d07SSam Ravnborg	  One use is for the kexec on panic case where the recovery kernel
2096506f1d07SSam Ravnborg	  must live at a different physical address than the primary
2097506f1d07SSam Ravnborg	  kernel.
2098506f1d07SSam Ravnborg
2099506f1d07SSam Ravnborg	  Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address
2100506f1d07SSam Ravnborg	  it has been loaded at and the compile time physical address
21018ab3820fSKees Cook	  (CONFIG_PHYSICAL_START) is used as the minimum location.
2102506f1d07SSam Ravnborg
21038ab3820fSKees Cookconfig RANDOMIZE_BASE
2104e8581e3dSBaoquan He	bool "Randomize the address of the kernel image (KASLR)"
21058ab3820fSKees Cook	depends on RELOCATABLE
21066807c846SIngo Molnar	default y
21078ab3820fSKees Cook	---help---
2108e8581e3dSBaoquan He	  In support of Kernel Address Space Layout Randomization (KASLR),
2109e8581e3dSBaoquan He	  this randomizes the physical address at which the kernel image
2110e8581e3dSBaoquan He	  is decompressed and the virtual address where the kernel
2111e8581e3dSBaoquan He	  image is mapped, as a security feature that deters exploit
2112e8581e3dSBaoquan He	  attempts relying on knowledge of the location of kernel
2113e8581e3dSBaoquan He	  code internals.
2114e8581e3dSBaoquan He
2115ed9f007eSKees Cook	  On 64-bit, the kernel physical and virtual addresses are
2116ed9f007eSKees Cook	  randomized separately. The physical address will be anywhere
2117ed9f007eSKees Cook	  between 16MB and the top of physical memory (up to 64TB). The
2118ed9f007eSKees Cook	  virtual address will be randomized from 16MB up to 1GB (9 bits
2119ed9f007eSKees Cook	  of entropy). Note that this also reduces the memory space
2120ed9f007eSKees Cook	  available to kernel modules from 1.5GB to 1GB.
2121ed9f007eSKees Cook
2122ed9f007eSKees Cook	  On 32-bit, the kernel physical and virtual addresses are
2123ed9f007eSKees Cook	  randomized together. They will be randomized from 16MB up to
2124ed9f007eSKees Cook	  512MB (8 bits of entropy).
21258ab3820fSKees Cook
2126a653f356SKees Cook	  Entropy is generated using the RDRAND instruction if it is
2127e8581e3dSBaoquan He	  supported. If RDTSC is supported, its value is mixed into
2128e8581e3dSBaoquan He	  the entropy pool as well. If neither RDRAND nor RDTSC are
2129ed9f007eSKees Cook	  supported, then entropy is read from the i8254 timer. The
2130ed9f007eSKees Cook	  usable entropy is limited by the kernel being built using
2131ed9f007eSKees Cook	  2GB addressing, and that PHYSICAL_ALIGN must be at a
2132ed9f007eSKees Cook	  minimum of 2MB. As a result, only 10 bits of entropy are
2133ed9f007eSKees Cook	  theoretically possible, but the implementations are further
2134ed9f007eSKees Cook	  limited due to memory layouts.
2135e8581e3dSBaoquan He
21366807c846SIngo Molnar	  If unsure, say Y.
2137da2b6fb9SKees Cook
21388ab3820fSKees Cook# Relocation on x86 needs some additional build support
2139845adf72SH. Peter Anvinconfig X86_NEED_RELOCS
2140845adf72SH. Peter Anvin	def_bool y
21418ab3820fSKees Cook	depends on RANDOMIZE_BASE || (X86_32 && RELOCATABLE)
2142845adf72SH. Peter Anvin
2143506f1d07SSam Ravnborgconfig PHYSICAL_ALIGN
2144a0215061SKees Cook	hex "Alignment value to which kernel should be aligned"
21458ab3820fSKees Cook	default "0x200000"
2146a0215061SKees Cook	range 0x2000 0x1000000 if X86_32
2147a0215061SKees Cook	range 0x200000 0x1000000 if X86_64
21488f9ca475SIngo Molnar	---help---
2149506f1d07SSam Ravnborg	  This value puts the alignment restrictions on physical address
2150506f1d07SSam Ravnborg	  where kernel is loaded and run from. Kernel is compiled for an
2151506f1d07SSam Ravnborg	  address which meets above alignment restriction.
2152506f1d07SSam Ravnborg
2153506f1d07SSam Ravnborg	  If bootloader loads the kernel at a non-aligned address and
2154506f1d07SSam Ravnborg	  CONFIG_RELOCATABLE is set, kernel will move itself to nearest
2155506f1d07SSam Ravnborg	  address aligned to above value and run from there.
2156506f1d07SSam Ravnborg
2157506f1d07SSam Ravnborg	  If bootloader loads the kernel at a non-aligned address and
2158506f1d07SSam Ravnborg	  CONFIG_RELOCATABLE is not set, kernel will ignore the run time
2159506f1d07SSam Ravnborg	  load address and decompress itself to the address it has been
2160506f1d07SSam Ravnborg	  compiled for and run from there. The address for which kernel is
2161506f1d07SSam Ravnborg	  compiled already meets above alignment restrictions. Hence the
2162506f1d07SSam Ravnborg	  end result is that kernel runs from a physical address meeting
2163506f1d07SSam Ravnborg	  above alignment restrictions.
2164506f1d07SSam Ravnborg
2165a0215061SKees Cook	  On 32-bit this value must be a multiple of 0x2000. On 64-bit
2166a0215061SKees Cook	  this value must be a multiple of 0x200000.
2167a0215061SKees Cook
2168506f1d07SSam Ravnborg	  Don't change this unless you know what you are doing.
2169506f1d07SSam Ravnborg
2170eedb92abSKirill A. Shutemovconfig DYNAMIC_MEMORY_LAYOUT
2171eedb92abSKirill A. Shutemov	bool
2172eedb92abSKirill A. Shutemov	---help---
2173eedb92abSKirill A. Shutemov	  This option makes base addresses of vmalloc and vmemmap as well as
2174eedb92abSKirill A. Shutemov	  __PAGE_OFFSET movable during boot.
2175eedb92abSKirill A. Shutemov
21760483e1faSThomas Garnierconfig RANDOMIZE_MEMORY
21770483e1faSThomas Garnier	bool "Randomize the kernel memory sections"
21780483e1faSThomas Garnier	depends on X86_64
21790483e1faSThomas Garnier	depends on RANDOMIZE_BASE
2180eedb92abSKirill A. Shutemov	select DYNAMIC_MEMORY_LAYOUT
21810483e1faSThomas Garnier	default RANDOMIZE_BASE
21820483e1faSThomas Garnier	---help---
21830483e1faSThomas Garnier	   Randomizes the base virtual address of kernel memory sections
21840483e1faSThomas Garnier	   (physical memory mapping, vmalloc & vmemmap). This security feature
21850483e1faSThomas Garnier	   makes exploits relying on predictable memory locations less reliable.
21860483e1faSThomas Garnier
21870483e1faSThomas Garnier	   The order of allocations remains unchanged. Entropy is generated in
21880483e1faSThomas Garnier	   the same way as RANDOMIZE_BASE. Current implementation in the optimal
21890483e1faSThomas Garnier	   configuration have in average 30,000 different possible virtual
21900483e1faSThomas Garnier	   addresses for each memory section.
21910483e1faSThomas Garnier
21926807c846SIngo Molnar	   If unsure, say Y.
21930483e1faSThomas Garnier
219490397a41SThomas Garnierconfig RANDOMIZE_MEMORY_PHYSICAL_PADDING
219590397a41SThomas Garnier	hex "Physical memory mapping padding" if EXPERT
219690397a41SThomas Garnier	depends on RANDOMIZE_MEMORY
219790397a41SThomas Garnier	default "0xa" if MEMORY_HOTPLUG
219890397a41SThomas Garnier	default "0x0"
219990397a41SThomas Garnier	range 0x1 0x40 if MEMORY_HOTPLUG
220090397a41SThomas Garnier	range 0x0 0x40
220190397a41SThomas Garnier	---help---
220290397a41SThomas Garnier	   Define the padding in terabytes added to the existing physical
220390397a41SThomas Garnier	   memory size during kernel memory randomization. It is useful
220490397a41SThomas Garnier	   for memory hotplug support but reduces the entropy available for
220590397a41SThomas Garnier	   address randomization.
220690397a41SThomas Garnier
220790397a41SThomas Garnier	   If unsure, leave at the default value.
220890397a41SThomas Garnier
2209506f1d07SSam Ravnborgconfig HOTPLUG_CPU
2210bebd024eSThomas Gleixner	def_bool y
221140b31360SStephen Rothwell	depends on SMP
2212506f1d07SSam Ravnborg
221380aa1dffSFenghua Yuconfig BOOTPARAM_HOTPLUG_CPU0
221480aa1dffSFenghua Yu	bool "Set default setting of cpu0_hotpluggable"
22152c922cd0SKees Cook	depends on HOTPLUG_CPU
221680aa1dffSFenghua Yu	---help---
221780aa1dffSFenghua Yu	  Set whether default state of cpu0_hotpluggable is on or off.
221880aa1dffSFenghua Yu
221980aa1dffSFenghua Yu	  Say Y here to enable CPU0 hotplug by default. If this switch
222080aa1dffSFenghua Yu	  is turned on, there is no need to give cpu0_hotplug kernel
222180aa1dffSFenghua Yu	  parameter and the CPU0 hotplug feature is enabled by default.
222280aa1dffSFenghua Yu
222380aa1dffSFenghua Yu	  Please note: there are two known CPU0 dependencies if you want
222480aa1dffSFenghua Yu	  to enable the CPU0 hotplug feature either by this switch or by
222580aa1dffSFenghua Yu	  cpu0_hotplug kernel parameter.
222680aa1dffSFenghua Yu
222780aa1dffSFenghua Yu	  First, resume from hibernate or suspend always starts from CPU0.
222880aa1dffSFenghua Yu	  So hibernate and suspend are prevented if CPU0 is offline.
222980aa1dffSFenghua Yu
223080aa1dffSFenghua Yu	  Second dependency is PIC interrupts always go to CPU0. CPU0 can not
223180aa1dffSFenghua Yu	  offline if any interrupt can not migrate out of CPU0. There may
223280aa1dffSFenghua Yu	  be other CPU0 dependencies.
223380aa1dffSFenghua Yu
223480aa1dffSFenghua Yu	  Please make sure the dependencies are under your control before
223580aa1dffSFenghua Yu	  you enable this feature.
223680aa1dffSFenghua Yu
223780aa1dffSFenghua Yu	  Say N if you don't want to enable CPU0 hotplug feature by default.
223880aa1dffSFenghua Yu	  You still can enable the CPU0 hotplug feature at boot by kernel
223980aa1dffSFenghua Yu	  parameter cpu0_hotplug.
224080aa1dffSFenghua Yu
2241a71c8bc5SFenghua Yuconfig DEBUG_HOTPLUG_CPU0
2242a71c8bc5SFenghua Yu	def_bool n
2243a71c8bc5SFenghua Yu	prompt "Debug CPU0 hotplug"
22442c922cd0SKees Cook	depends on HOTPLUG_CPU
2245a71c8bc5SFenghua Yu	---help---
2246a71c8bc5SFenghua Yu	  Enabling this option offlines CPU0 (if CPU0 can be offlined) as
2247a71c8bc5SFenghua Yu	  soon as possible and boots up userspace with CPU0 offlined. User
2248a71c8bc5SFenghua Yu	  can online CPU0 back after boot time.
2249a71c8bc5SFenghua Yu
2250a71c8bc5SFenghua Yu	  To debug CPU0 hotplug, you need to enable CPU0 offline/online
2251a71c8bc5SFenghua Yu	  feature by either turning on CONFIG_BOOTPARAM_HOTPLUG_CPU0 during
2252a71c8bc5SFenghua Yu	  compilation or giving cpu0_hotplug kernel parameter at boot.
2253a71c8bc5SFenghua Yu
2254a71c8bc5SFenghua Yu	  If unsure, say N.
2255a71c8bc5SFenghua Yu
2256506f1d07SSam Ravnborgconfig COMPAT_VDSO
2257b0b49f26SAndy Lutomirski	def_bool n
2258b0b49f26SAndy Lutomirski	prompt "Disable the 32-bit vDSO (needed for glibc 2.3.3)"
2259953fee1dSIngo Molnar	depends on COMPAT_32
22608f9ca475SIngo Molnar	---help---
2261b0b49f26SAndy Lutomirski	  Certain buggy versions of glibc will crash if they are
2262b0b49f26SAndy Lutomirski	  presented with a 32-bit vDSO that is not mapped at the address
2263b0b49f26SAndy Lutomirski	  indicated in its segment table.
2264e84446deSRandy Dunlap
2265b0b49f26SAndy Lutomirski	  The bug was introduced by f866314b89d56845f55e6f365e18b31ec978ec3a
2266b0b49f26SAndy Lutomirski	  and fixed by 3b3ddb4f7db98ec9e912ccdf54d35df4aa30e04a and
2267b0b49f26SAndy Lutomirski	  49ad572a70b8aeb91e57483a11dd1b77e31c4468.  Glibc 2.3.3 is
2268b0b49f26SAndy Lutomirski	  the only released version with the bug, but OpenSUSE 9
2269b0b49f26SAndy Lutomirski	  contains a buggy "glibc 2.3.2".
2270506f1d07SSam Ravnborg
2271b0b49f26SAndy Lutomirski	  The symptom of the bug is that everything crashes on startup, saying:
2272b0b49f26SAndy Lutomirski	  dl_main: Assertion `(void *) ph->p_vaddr == _rtld_local._dl_sysinfo_dso' failed!
2273b0b49f26SAndy Lutomirski
2274b0b49f26SAndy Lutomirski	  Saying Y here changes the default value of the vdso32 boot
2275b0b49f26SAndy Lutomirski	  option from 1 to 0, which turns off the 32-bit vDSO entirely.
2276b0b49f26SAndy Lutomirski	  This works around the glibc bug but hurts performance.
2277b0b49f26SAndy Lutomirski
2278b0b49f26SAndy Lutomirski	  If unsure, say N: if you are compiling your own kernel, you
2279b0b49f26SAndy Lutomirski	  are unlikely to be using a buggy version of glibc.
2280506f1d07SSam Ravnborg
22813dc33bd3SKees Cookchoice
22823dc33bd3SKees Cook	prompt "vsyscall table for legacy applications"
22833dc33bd3SKees Cook	depends on X86_64
22843dc33bd3SKees Cook	default LEGACY_VSYSCALL_EMULATE
22853dc33bd3SKees Cook	help
22863dc33bd3SKees Cook	  Legacy user code that does not know how to find the vDSO expects
22873dc33bd3SKees Cook	  to be able to issue three syscalls by calling fixed addresses in
22883dc33bd3SKees Cook	  kernel space. Since this location is not randomized with ASLR,
22893dc33bd3SKees Cook	  it can be used to assist security vulnerability exploitation.
22903dc33bd3SKees Cook
22913dc33bd3SKees Cook	  This setting can be changed at boot time via the kernel command
2292076ca272SAndy Lutomirski	  line parameter vsyscall=[emulate|none].
22933dc33bd3SKees Cook
22943dc33bd3SKees Cook	  On a system with recent enough glibc (2.14 or newer) and no
22953dc33bd3SKees Cook	  static binaries, you can say None without a performance penalty
22963dc33bd3SKees Cook	  to improve security.
22973dc33bd3SKees Cook
22983dc33bd3SKees Cook	  If unsure, select "Emulate".
22993dc33bd3SKees Cook
23003dc33bd3SKees Cook	config LEGACY_VSYSCALL_EMULATE
23013dc33bd3SKees Cook		bool "Emulate"
23023dc33bd3SKees Cook		help
23033dc33bd3SKees Cook		  The kernel traps and emulates calls into the fixed
23043dc33bd3SKees Cook		  vsyscall address mapping. This makes the mapping
23053dc33bd3SKees Cook		  non-executable, but it still contains known contents,
23063dc33bd3SKees Cook		  which could be used in certain rare security vulnerability
23073dc33bd3SKees Cook		  exploits. This configuration is recommended when userspace
23083dc33bd3SKees Cook		  still uses the vsyscall area.
23093dc33bd3SKees Cook
23103dc33bd3SKees Cook	config LEGACY_VSYSCALL_NONE
23113dc33bd3SKees Cook		bool "None"
23123dc33bd3SKees Cook		help
23133dc33bd3SKees Cook		  There will be no vsyscall mapping at all. This will
23143dc33bd3SKees Cook		  eliminate any risk of ASLR bypass due to the vsyscall
23153dc33bd3SKees Cook		  fixed address mapping. Attempts to use the vsyscalls
23163dc33bd3SKees Cook		  will be reported to dmesg, so that either old or
23173dc33bd3SKees Cook		  malicious userspace programs can be identified.
23183dc33bd3SKees Cook
23193dc33bd3SKees Cookendchoice
23203dc33bd3SKees Cook
2321516cbf37STim Birdconfig CMDLINE_BOOL
2322516cbf37STim Bird	bool "Built-in kernel command line"
23238f9ca475SIngo Molnar	---help---
2324516cbf37STim Bird	  Allow for specifying boot arguments to the kernel at
2325516cbf37STim Bird	  build time.  On some systems (e.g. embedded ones), it is
2326516cbf37STim Bird	  necessary or convenient to provide some or all of the
2327516cbf37STim Bird	  kernel boot arguments with the kernel itself (that is,
2328516cbf37STim Bird	  to not rely on the boot loader to provide them.)
2329516cbf37STim Bird
2330516cbf37STim Bird	  To compile command line arguments into the kernel,
2331516cbf37STim Bird	  set this option to 'Y', then fill in the
233269711ca1SSébastien Hinderer	  boot arguments in CONFIG_CMDLINE.
2333516cbf37STim Bird
2334516cbf37STim Bird	  Systems with fully functional boot loaders (i.e. non-embedded)
2335516cbf37STim Bird	  should leave this option set to 'N'.
2336516cbf37STim Bird
2337516cbf37STim Birdconfig CMDLINE
2338516cbf37STim Bird	string "Built-in kernel command string"
2339516cbf37STim Bird	depends on CMDLINE_BOOL
2340516cbf37STim Bird	default ""
23418f9ca475SIngo Molnar	---help---
2342516cbf37STim Bird	  Enter arguments here that should be compiled into the kernel
2343516cbf37STim Bird	  image and used at boot time.  If the boot loader provides a
2344516cbf37STim Bird	  command line at boot time, it is appended to this string to
2345516cbf37STim Bird	  form the full kernel command line, when the system boots.
2346516cbf37STim Bird
2347516cbf37STim Bird	  However, you can use the CONFIG_CMDLINE_OVERRIDE option to
2348516cbf37STim Bird	  change this behavior.
2349516cbf37STim Bird
2350516cbf37STim Bird	  In most cases, the command line (whether built-in or provided
2351516cbf37STim Bird	  by the boot loader) should specify the device for the root
2352516cbf37STim Bird	  file system.
2353516cbf37STim Bird
2354516cbf37STim Birdconfig CMDLINE_OVERRIDE
2355516cbf37STim Bird	bool "Built-in command line overrides boot loader arguments"
2356516cbf37STim Bird	depends on CMDLINE_BOOL
23578f9ca475SIngo Molnar	---help---
2358516cbf37STim Bird	  Set this option to 'Y' to have the kernel ignore the boot loader
2359516cbf37STim Bird	  command line, and use ONLY the built-in command line.
2360516cbf37STim Bird
2361516cbf37STim Bird	  This is used to work around broken boot loaders.  This should
2362516cbf37STim Bird	  be set to 'N' under normal conditions.
2363516cbf37STim Bird
2364a5b9e5a2SAndy Lutomirskiconfig MODIFY_LDT_SYSCALL
2365a5b9e5a2SAndy Lutomirski	bool "Enable the LDT (local descriptor table)" if EXPERT
2366a5b9e5a2SAndy Lutomirski	default y
2367a5b9e5a2SAndy Lutomirski	---help---
2368a5b9e5a2SAndy Lutomirski	  Linux can allow user programs to install a per-process x86
2369a5b9e5a2SAndy Lutomirski	  Local Descriptor Table (LDT) using the modify_ldt(2) system
2370a5b9e5a2SAndy Lutomirski	  call.  This is required to run 16-bit or segmented code such as
2371a5b9e5a2SAndy Lutomirski	  DOSEMU or some Wine programs.  It is also used by some very old
2372a5b9e5a2SAndy Lutomirski	  threading libraries.
2373a5b9e5a2SAndy Lutomirski
2374a5b9e5a2SAndy Lutomirski	  Enabling this feature adds a small amount of overhead to
2375a5b9e5a2SAndy Lutomirski	  context switches and increases the low-level kernel attack
2376a5b9e5a2SAndy Lutomirski	  surface.  Disabling it removes the modify_ldt(2) system call.
2377a5b9e5a2SAndy Lutomirski
2378a5b9e5a2SAndy Lutomirski	  Saying 'N' here may make sense for embedded or server kernels.
2379a5b9e5a2SAndy Lutomirski
2380b700e7f0SSeth Jenningssource "kernel/livepatch/Kconfig"
2381b700e7f0SSeth Jennings
2382506f1d07SSam Ravnborgendmenu
2383506f1d07SSam Ravnborg
23843072e413SMichal Hockoconfig ARCH_HAS_ADD_PAGES
23853072e413SMichal Hocko	def_bool y
23863072e413SMichal Hocko	depends on X86_64 && ARCH_ENABLE_MEMORY_HOTPLUG
23873072e413SMichal Hocko
2388506f1d07SSam Ravnborgconfig ARCH_ENABLE_MEMORY_HOTPLUG
2389506f1d07SSam Ravnborg	def_bool y
2390506f1d07SSam Ravnborg	depends on X86_64 || (X86_32 && HIGHMEM)
2391506f1d07SSam Ravnborg
239235551053SGary Hadeconfig ARCH_ENABLE_MEMORY_HOTREMOVE
239335551053SGary Hade	def_bool y
239435551053SGary Hade	depends on MEMORY_HOTPLUG
239535551053SGary Hade
2396e534c7c5SLee Schermerhornconfig USE_PERCPU_NUMA_NODE_ID
2397645a7919STejun Heo	def_bool y
2398e534c7c5SLee Schermerhorn	depends on NUMA
2399e534c7c5SLee Schermerhorn
24009491846fSKirill A. Shutemovconfig ARCH_ENABLE_SPLIT_PMD_PTLOCK
24019491846fSKirill A. Shutemov	def_bool y
24029491846fSKirill A. Shutemov	depends on X86_64 || X86_PAE
24039491846fSKirill A. Shutemov
2404c177c81eSNaoya Horiguchiconfig ARCH_ENABLE_HUGEPAGE_MIGRATION
2405c177c81eSNaoya Horiguchi	def_bool y
2406c177c81eSNaoya Horiguchi	depends on X86_64 && HUGETLB_PAGE && MIGRATION
2407c177c81eSNaoya Horiguchi
24089c670ea3SNaoya Horiguchiconfig ARCH_ENABLE_THP_MIGRATION
24099c670ea3SNaoya Horiguchi	def_bool y
24109c670ea3SNaoya Horiguchi	depends on X86_64 && TRANSPARENT_HUGEPAGE
24119c670ea3SNaoya Horiguchi
2412da85f865SBjorn Helgaasmenu "Power management and ACPI options"
2413e279b6c1SSam Ravnborg
2414e279b6c1SSam Ravnborgconfig ARCH_HIBERNATION_HEADER
24153c2362e6SHarvey Harrison	def_bool y
241644556530SZhimin Gu	depends on HIBERNATION
2417e279b6c1SSam Ravnborg
2418e279b6c1SSam Ravnborgsource "kernel/power/Kconfig"
2419e279b6c1SSam Ravnborg
2420e279b6c1SSam Ravnborgsource "drivers/acpi/Kconfig"
2421e279b6c1SSam Ravnborg
2422efafc8b2SFeng Tangsource "drivers/sfi/Kconfig"
2423efafc8b2SFeng Tang
2424a6b68076SAndi Kleenconfig X86_APM_BOOT
24256fc108a0SJan Beulich	def_bool y
2426282e5aabSPaul Bolle	depends on APM
2427a6b68076SAndi Kleen
2428e279b6c1SSam Ravnborgmenuconfig APM
2429e279b6c1SSam Ravnborg	tristate "APM (Advanced Power Management) BIOS support"
2430efefa6f6SIngo Molnar	depends on X86_32 && PM_SLEEP
2431e279b6c1SSam Ravnborg	---help---
2432e279b6c1SSam Ravnborg	  APM is a BIOS specification for saving power using several different
2433e279b6c1SSam Ravnborg	  techniques. This is mostly useful for battery powered laptops with
2434e279b6c1SSam Ravnborg	  APM compliant BIOSes. If you say Y here, the system time will be
2435e279b6c1SSam Ravnborg	  reset after a RESUME operation, the /proc/apm device will provide
2436e279b6c1SSam Ravnborg	  battery status information, and user-space programs will receive
2437e279b6c1SSam Ravnborg	  notification of APM "events" (e.g. battery status change).
2438e279b6c1SSam Ravnborg
2439e279b6c1SSam Ravnborg	  If you select "Y" here, you can disable actual use of the APM
2440e279b6c1SSam Ravnborg	  BIOS by passing the "apm=off" option to the kernel at boot time.
2441e279b6c1SSam Ravnborg
2442e279b6c1SSam Ravnborg	  Note that the APM support is almost completely disabled for
2443e279b6c1SSam Ravnborg	  machines with more than one CPU.
2444e279b6c1SSam Ravnborg
2445e279b6c1SSam Ravnborg	  In order to use APM, you will need supporting software. For location
24462dc98fd3SMichael Witten	  and more information, read <file:Documentation/power/apm-acpi.txt>
24472dc98fd3SMichael Witten	  and the Battery Powered Linux mini-HOWTO, available from
2448e279b6c1SSam Ravnborg	  <http://www.tldp.org/docs.html#howto>.
2449e279b6c1SSam Ravnborg
2450e279b6c1SSam Ravnborg	  This driver does not spin down disk drives (see the hdparm(8)
2451e279b6c1SSam Ravnborg	  manpage ("man 8 hdparm") for that), and it doesn't turn off
2452e279b6c1SSam Ravnborg	  VESA-compliant "green" monitors.
2453e279b6c1SSam Ravnborg
2454e279b6c1SSam Ravnborg	  This driver does not support the TI 4000M TravelMate and the ACER
2455e279b6c1SSam Ravnborg	  486/DX4/75 because they don't have compliant BIOSes. Many "green"
2456e279b6c1SSam Ravnborg	  desktop machines also don't have compliant BIOSes, and this driver
2457e279b6c1SSam Ravnborg	  may cause those machines to panic during the boot phase.
2458e279b6c1SSam Ravnborg
2459e279b6c1SSam Ravnborg	  Generally, if you don't have a battery in your machine, there isn't
2460e279b6c1SSam Ravnborg	  much point in using this driver and you should say N. If you get
2461e279b6c1SSam Ravnborg	  random kernel OOPSes or reboots that don't seem to be related to
2462e279b6c1SSam Ravnborg	  anything, try disabling/enabling this option (or disabling/enabling
2463e279b6c1SSam Ravnborg	  APM in your BIOS).
2464e279b6c1SSam Ravnborg
2465e279b6c1SSam Ravnborg	  Some other things you should try when experiencing seemingly random,
2466e279b6c1SSam Ravnborg	  "weird" problems:
2467e279b6c1SSam Ravnborg
2468e279b6c1SSam Ravnborg	  1) make sure that you have enough swap space and that it is
2469e279b6c1SSam Ravnborg	  enabled.
2470e279b6c1SSam Ravnborg	  2) pass the "no-hlt" option to the kernel
2471e279b6c1SSam Ravnborg	  3) switch on floating point emulation in the kernel and pass
2472e279b6c1SSam Ravnborg	  the "no387" option to the kernel
2473e279b6c1SSam Ravnborg	  4) pass the "floppy=nodma" option to the kernel
2474e279b6c1SSam Ravnborg	  5) pass the "mem=4M" option to the kernel (thereby disabling
2475e279b6c1SSam Ravnborg	  all but the first 4 MB of RAM)
2476e279b6c1SSam Ravnborg	  6) make sure that the CPU is not over clocked.
2477e279b6c1SSam Ravnborg	  7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/>
2478e279b6c1SSam Ravnborg	  8) disable the cache from your BIOS settings
2479e279b6c1SSam Ravnborg	  9) install a fan for the video card or exchange video RAM
2480e279b6c1SSam Ravnborg	  10) install a better fan for the CPU
2481e279b6c1SSam Ravnborg	  11) exchange RAM chips
2482e279b6c1SSam Ravnborg	  12) exchange the motherboard.
2483e279b6c1SSam Ravnborg
2484e279b6c1SSam Ravnborg	  To compile this driver as a module, choose M here: the
2485e279b6c1SSam Ravnborg	  module will be called apm.
2486e279b6c1SSam Ravnborg
2487e279b6c1SSam Ravnborgif APM
2488e279b6c1SSam Ravnborg
2489e279b6c1SSam Ravnborgconfig APM_IGNORE_USER_SUSPEND
2490e279b6c1SSam Ravnborg	bool "Ignore USER SUSPEND"
24918f9ca475SIngo Molnar	---help---
2492e279b6c1SSam Ravnborg	  This option will ignore USER SUSPEND requests. On machines with a
2493e279b6c1SSam Ravnborg	  compliant APM BIOS, you want to say N. However, on the NEC Versa M
2494e279b6c1SSam Ravnborg	  series notebooks, it is necessary to say Y because of a BIOS bug.
2495e279b6c1SSam Ravnborg
2496e279b6c1SSam Ravnborgconfig APM_DO_ENABLE
2497e279b6c1SSam Ravnborg	bool "Enable PM at boot time"
2498e279b6c1SSam Ravnborg	---help---
2499e279b6c1SSam Ravnborg	  Enable APM features at boot time. From page 36 of the APM BIOS
2500e279b6c1SSam Ravnborg	  specification: "When disabled, the APM BIOS does not automatically
2501e279b6c1SSam Ravnborg	  power manage devices, enter the Standby State, enter the Suspend
2502e279b6c1SSam Ravnborg	  State, or take power saving steps in response to CPU Idle calls."
2503e279b6c1SSam Ravnborg	  This driver will make CPU Idle calls when Linux is idle (unless this
2504e279b6c1SSam Ravnborg	  feature is turned off -- see "Do CPU IDLE calls", below). This
2505e279b6c1SSam Ravnborg	  should always save battery power, but more complicated APM features
2506e279b6c1SSam Ravnborg	  will be dependent on your BIOS implementation. You may need to turn
2507e279b6c1SSam Ravnborg	  this option off if your computer hangs at boot time when using APM
2508e279b6c1SSam Ravnborg	  support, or if it beeps continuously instead of suspending. Turn
2509e279b6c1SSam Ravnborg	  this off if you have a NEC UltraLite Versa 33/C or a Toshiba
2510e279b6c1SSam Ravnborg	  T400CDT. This is off by default since most machines do fine without
2511e279b6c1SSam Ravnborg	  this feature.
2512e279b6c1SSam Ravnborg
2513e279b6c1SSam Ravnborgconfig APM_CPU_IDLE
2514dd8af076SLen Brown	depends on CPU_IDLE
2515e279b6c1SSam Ravnborg	bool "Make CPU Idle calls when idle"
25168f9ca475SIngo Molnar	---help---
2517e279b6c1SSam Ravnborg	  Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop.
2518e279b6c1SSam Ravnborg	  On some machines, this can activate improved power savings, such as
2519e279b6c1SSam Ravnborg	  a slowed CPU clock rate, when the machine is idle. These idle calls
2520e279b6c1SSam Ravnborg	  are made after the idle loop has run for some length of time (e.g.,
2521e279b6c1SSam Ravnborg	  333 mS). On some machines, this will cause a hang at boot time or
2522e279b6c1SSam Ravnborg	  whenever the CPU becomes idle. (On machines with more than one CPU,
2523e279b6c1SSam Ravnborg	  this option does nothing.)
2524e279b6c1SSam Ravnborg
2525e279b6c1SSam Ravnborgconfig APM_DISPLAY_BLANK
2526e279b6c1SSam Ravnborg	bool "Enable console blanking using APM"
25278f9ca475SIngo Molnar	---help---
2528e279b6c1SSam Ravnborg	  Enable console blanking using the APM. Some laptops can use this to
2529e279b6c1SSam Ravnborg	  turn off the LCD backlight when the screen blanker of the Linux
2530e279b6c1SSam Ravnborg	  virtual console blanks the screen. Note that this is only used by
2531e279b6c1SSam Ravnborg	  the virtual console screen blanker, and won't turn off the backlight
2532e279b6c1SSam Ravnborg	  when using the X Window system. This also doesn't have anything to
2533e279b6c1SSam Ravnborg	  do with your VESA-compliant power-saving monitor. Further, this
2534e279b6c1SSam Ravnborg	  option doesn't work for all laptops -- it might not turn off your
2535e279b6c1SSam Ravnborg	  backlight at all, or it might print a lot of errors to the console,
2536e279b6c1SSam Ravnborg	  especially if you are using gpm.
2537e279b6c1SSam Ravnborg
2538e279b6c1SSam Ravnborgconfig APM_ALLOW_INTS
2539e279b6c1SSam Ravnborg	bool "Allow interrupts during APM BIOS calls"
25408f9ca475SIngo Molnar	---help---
2541e279b6c1SSam Ravnborg	  Normally we disable external interrupts while we are making calls to
2542e279b6c1SSam Ravnborg	  the APM BIOS as a measure to lessen the effects of a badly behaving
2543e279b6c1SSam Ravnborg	  BIOS implementation.  The BIOS should reenable interrupts if it
2544e279b6c1SSam Ravnborg	  needs to.  Unfortunately, some BIOSes do not -- especially those in
2545e279b6c1SSam Ravnborg	  many of the newer IBM Thinkpads.  If you experience hangs when you
2546e279b6c1SSam Ravnborg	  suspend, try setting this to Y.  Otherwise, say N.
2547e279b6c1SSam Ravnborg
2548e279b6c1SSam Ravnborgendif # APM
2549e279b6c1SSam Ravnborg
2550bb0a56ecSDave Jonessource "drivers/cpufreq/Kconfig"
2551e279b6c1SSam Ravnborg
2552e279b6c1SSam Ravnborgsource "drivers/cpuidle/Kconfig"
2553e279b6c1SSam Ravnborg
255427471fdbSAndy Henroidsource "drivers/idle/Kconfig"
255527471fdbSAndy Henroid
2556e279b6c1SSam Ravnborgendmenu
2557e279b6c1SSam Ravnborg
2558e279b6c1SSam Ravnborg
2559e279b6c1SSam Ravnborgmenu "Bus options (PCI etc.)"
2560e279b6c1SSam Ravnborg
2561e279b6c1SSam Ravnborgchoice
2562e279b6c1SSam Ravnborg	prompt "PCI access mode"
2563efefa6f6SIngo Molnar	depends on X86_32 && PCI
2564e279b6c1SSam Ravnborg	default PCI_GOANY
2565e279b6c1SSam Ravnborg	---help---
2566e279b6c1SSam Ravnborg	  On PCI systems, the BIOS can be used to detect the PCI devices and
2567e279b6c1SSam Ravnborg	  determine their configuration. However, some old PCI motherboards
2568e279b6c1SSam Ravnborg	  have BIOS bugs and may crash if this is done. Also, some embedded
2569e279b6c1SSam Ravnborg	  PCI-based systems don't have any BIOS at all. Linux can also try to
2570e279b6c1SSam Ravnborg	  detect the PCI hardware directly without using the BIOS.
2571e279b6c1SSam Ravnborg
2572e279b6c1SSam Ravnborg	  With this option, you can specify how Linux should detect the
2573e279b6c1SSam Ravnborg	  PCI devices. If you choose "BIOS", the BIOS will be used,
2574e279b6c1SSam Ravnborg	  if you choose "Direct", the BIOS won't be used, and if you
2575e279b6c1SSam Ravnborg	  choose "MMConfig", then PCI Express MMCONFIG will be used.
2576e279b6c1SSam Ravnborg	  If you choose "Any", the kernel will try MMCONFIG, then the
2577e279b6c1SSam Ravnborg	  direct access method and falls back to the BIOS if that doesn't
2578e279b6c1SSam Ravnborg	  work. If unsure, go with the default, which is "Any".
2579e279b6c1SSam Ravnborg
2580e279b6c1SSam Ravnborgconfig PCI_GOBIOS
2581e279b6c1SSam Ravnborg	bool "BIOS"
2582e279b6c1SSam Ravnborg
2583e279b6c1SSam Ravnborgconfig PCI_GOMMCONFIG
2584e279b6c1SSam Ravnborg	bool "MMConfig"
2585e279b6c1SSam Ravnborg
2586e279b6c1SSam Ravnborgconfig PCI_GODIRECT
2587e279b6c1SSam Ravnborg	bool "Direct"
2588e279b6c1SSam Ravnborg
25893ef0e1f8SAndres Salomonconfig PCI_GOOLPC
259076fb6570SDaniel Drake	bool "OLPC XO-1"
25913ef0e1f8SAndres Salomon	depends on OLPC
25923ef0e1f8SAndres Salomon
25932bdd1b03SAndres Salomonconfig PCI_GOANY
25942bdd1b03SAndres Salomon	bool "Any"
25952bdd1b03SAndres Salomon
2596e279b6c1SSam Ravnborgendchoice
2597e279b6c1SSam Ravnborg
2598e279b6c1SSam Ravnborgconfig PCI_BIOS
25993c2362e6SHarvey Harrison	def_bool y
2600efefa6f6SIngo Molnar	depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY)
2601e279b6c1SSam Ravnborg
2602e279b6c1SSam Ravnborg# x86-64 doesn't support PCI BIOS access from long mode so always go direct.
2603e279b6c1SSam Ravnborgconfig PCI_DIRECT
26043c2362e6SHarvey Harrison	def_bool y
26050aba496fSShaohua Li	depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC || PCI_GOMMCONFIG))
2606e279b6c1SSam Ravnborg
2607e279b6c1SSam Ravnborgconfig PCI_MMCONFIG
2608b45c9f36SJan Kiszka	bool "Support mmconfig PCI config space access" if X86_64
2609b45c9f36SJan Kiszka	default y
26108364e1f8SJan Kiszka	depends on PCI && (ACPI || SFI || JAILHOUSE_GUEST)
2611b45c9f36SJan Kiszka	depends on X86_64 || (PCI_GOANY || PCI_GOMMCONFIG)
2612e279b6c1SSam Ravnborg
26133ef0e1f8SAndres Salomonconfig PCI_OLPC
26142bdd1b03SAndres Salomon	def_bool y
26152bdd1b03SAndres Salomon	depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY)
26163ef0e1f8SAndres Salomon
2617b5401a96SAlex Nixonconfig PCI_XEN
2618b5401a96SAlex Nixon	def_bool y
2619b5401a96SAlex Nixon	depends on PCI && XEN
2620b5401a96SAlex Nixon	select SWIOTLB_XEN
2621b5401a96SAlex Nixon
26228364e1f8SJan Kiszkaconfig MMCONF_FAM10H
26238364e1f8SJan Kiszka	def_bool y
26248364e1f8SJan Kiszka	depends on X86_64 && PCI_MMCONFIG && ACPI
2625e279b6c1SSam Ravnborg
26263f6ea84aSIra W. Snyderconfig PCI_CNB20LE_QUIRK
26276a108a14SDavid Rientjes	bool "Read CNB20LE Host Bridge Windows" if EXPERT
26286ea30386SKees Cook	depends on PCI
26293f6ea84aSIra W. Snyder	help
26303f6ea84aSIra W. Snyder	  Read the PCI windows out of the CNB20LE host bridge. This allows
26313f6ea84aSIra W. Snyder	  PCI hotplug to work on systems with the CNB20LE chipset which do
26323f6ea84aSIra W. Snyder	  not have ACPI.
26333f6ea84aSIra W. Snyder
263464a5fed6SBjorn Helgaas	  There's no public spec for this chipset, and this functionality
263564a5fed6SBjorn Helgaas	  is known to be incomplete.
263664a5fed6SBjorn Helgaas
263764a5fed6SBjorn Helgaas	  You should say N unless you know you need this.
263864a5fed6SBjorn Helgaas
26393a495511SWilliam Breathitt Grayconfig ISA_BUS
264017a2a129SWilliam Breathitt Gray	bool "ISA bus support on modern systems" if EXPERT
26413a495511SWilliam Breathitt Gray	help
264217a2a129SWilliam Breathitt Gray	  Expose ISA bus device drivers and options available for selection and
264317a2a129SWilliam Breathitt Gray	  configuration. Enable this option if your target machine has an ISA
264417a2a129SWilliam Breathitt Gray	  bus. ISA is an older system, displaced by PCI and newer bus
264517a2a129SWilliam Breathitt Gray	  architectures -- if your target machine is modern, it probably does
264617a2a129SWilliam Breathitt Gray	  not have an ISA bus.
26473a495511SWilliam Breathitt Gray
26483a495511SWilliam Breathitt Gray	  If unsure, say N.
26493a495511SWilliam Breathitt Gray
26501c00f016SDavid Rientjes# x86_64 have no ISA slots, but can have ISA-style DMA.
2651e279b6c1SSam Ravnborgconfig ISA_DMA_API
26521c00f016SDavid Rientjes	bool "ISA-style DMA support" if (X86_64 && EXPERT)
26531c00f016SDavid Rientjes	default y
26541c00f016SDavid Rientjes	help
26551c00f016SDavid Rientjes	  Enables ISA-style DMA support for devices requiring such controllers.
26561c00f016SDavid Rientjes	  If unsure, say Y.
2657e279b6c1SSam Ravnborg
265851e68d05SLinus Torvaldsif X86_32
265951e68d05SLinus Torvalds
2660e279b6c1SSam Ravnborgconfig ISA
2661e279b6c1SSam Ravnborg	bool "ISA support"
26628f9ca475SIngo Molnar	---help---
2663e279b6c1SSam Ravnborg	  Find out whether you have ISA slots on your motherboard.  ISA is the
2664e279b6c1SSam Ravnborg	  name of a bus system, i.e. the way the CPU talks to the other stuff
2665e279b6c1SSam Ravnborg	  inside your box.  Other bus systems are PCI, EISA, MicroChannel
2666e279b6c1SSam Ravnborg	  (MCA) or VESA.  ISA is an older system, now being displaced by PCI;
2667e279b6c1SSam Ravnborg	  newer boards don't support it.  If you have ISA, say Y, otherwise N.
2668e279b6c1SSam Ravnborg
2669e279b6c1SSam Ravnborgconfig SCx200
2670e279b6c1SSam Ravnborg	tristate "NatSemi SCx200 support"
26718f9ca475SIngo Molnar	---help---
2672e279b6c1SSam Ravnborg	  This provides basic support for National Semiconductor's
2673e279b6c1SSam Ravnborg	  (now AMD's) Geode processors.  The driver probes for the
2674e279b6c1SSam Ravnborg	  PCI-IDs of several on-chip devices, so its a good dependency
2675e279b6c1SSam Ravnborg	  for other scx200_* drivers.
2676e279b6c1SSam Ravnborg
2677e279b6c1SSam Ravnborg	  If compiled as a module, the driver is named scx200.
2678e279b6c1SSam Ravnborg
2679e279b6c1SSam Ravnborgconfig SCx200HR_TIMER
2680e279b6c1SSam Ravnborg	tristate "NatSemi SCx200 27MHz High-Resolution Timer Support"
2681592913ecSJohn Stultz	depends on SCx200
2682e279b6c1SSam Ravnborg	default y
26838f9ca475SIngo Molnar	---help---
2684e279b6c1SSam Ravnborg	  This driver provides a clocksource built upon the on-chip
2685e279b6c1SSam Ravnborg	  27MHz high-resolution timer.  Its also a workaround for
2686e279b6c1SSam Ravnborg	  NSC Geode SC-1100's buggy TSC, which loses time when the
2687e279b6c1SSam Ravnborg	  processor goes idle (as is done by the scheduler).  The
2688e279b6c1SSam Ravnborg	  other workaround is idle=poll boot option.
2689e279b6c1SSam Ravnborg
26903ef0e1f8SAndres Salomonconfig OLPC
26913ef0e1f8SAndres Salomon	bool "One Laptop Per Child support"
269254008979SThomas Gleixner	depends on !X86_PAE
26933c554946SAndres Salomon	select GPIOLIB
2694dc3119e7SThomas Gleixner	select OF
269545bb1674SDaniel Drake	select OF_PROMTREE
2696b4e51854SGrant Likely	select IRQ_DOMAIN
26978f9ca475SIngo Molnar	---help---
26983ef0e1f8SAndres Salomon	  Add support for detecting the unique features of the OLPC
26993ef0e1f8SAndres Salomon	  XO hardware.
27003ef0e1f8SAndres Salomon
2701a3128588SDaniel Drakeconfig OLPC_XO1_PM
2702a3128588SDaniel Drake	bool "OLPC XO-1 Power Management"
2703fa112cf1SBorislav Petkov	depends on OLPC && MFD_CS5535=y && PM_SLEEP
2704bf1ebf00SDaniel Drake	---help---
270597c4cb71SDaniel Drake	  Add support for poweroff and suspend of the OLPC XO-1 laptop.
2706bf1ebf00SDaniel Drake
2707cfee9597SDaniel Drakeconfig OLPC_XO1_RTC
2708cfee9597SDaniel Drake	bool "OLPC XO-1 Real Time Clock"
2709cfee9597SDaniel Drake	depends on OLPC_XO1_PM && RTC_DRV_CMOS
2710cfee9597SDaniel Drake	---help---
2711cfee9597SDaniel Drake	  Add support for the XO-1 real time clock, which can be used as a
2712cfee9597SDaniel Drake	  programmable wakeup source.
2713cfee9597SDaniel Drake
27147feda8e9SDaniel Drakeconfig OLPC_XO1_SCI
27157feda8e9SDaniel Drake	bool "OLPC XO-1 SCI extras"
271692e830f2SArnd Bergmann	depends on OLPC && OLPC_XO1_PM && GPIO_CS5535=y
2717ed8e47feSRandy Dunlap	depends on INPUT=y
2718d8d01a63SDaniel Drake	select POWER_SUPPLY
27197feda8e9SDaniel Drake	---help---
27207feda8e9SDaniel Drake	  Add support for SCI-based features of the OLPC XO-1 laptop:
27217bc74b3dSDaniel Drake	   - EC-driven system wakeups
27227feda8e9SDaniel Drake	   - Power button
27237bc74b3dSDaniel Drake	   - Ebook switch
27242cf2baeaSDaniel Drake	   - Lid switch
2725e1040ac6SDaniel Drake	   - AC adapter status updates
2726e1040ac6SDaniel Drake	   - Battery status updates
27277feda8e9SDaniel Drake
2728a0f30f59SDaniel Drakeconfig OLPC_XO15_SCI
2729a0f30f59SDaniel Drake	bool "OLPC XO-1.5 SCI extras"
2730d8d01a63SDaniel Drake	depends on OLPC && ACPI
2731d8d01a63SDaniel Drake	select POWER_SUPPLY
2732a0f30f59SDaniel Drake	---help---
2733a0f30f59SDaniel Drake	  Add support for SCI-based features of the OLPC XO-1.5 laptop:
2734a0f30f59SDaniel Drake	   - EC-driven system wakeups
2735a0f30f59SDaniel Drake	   - AC adapter status updates
2736a0f30f59SDaniel Drake	   - Battery status updates
2737e279b6c1SSam Ravnborg
2738d4f3e350SEd Wildgooseconfig ALIX
2739d4f3e350SEd Wildgoose	bool "PCEngines ALIX System Support (LED setup)"
2740d4f3e350SEd Wildgoose	select GPIOLIB
2741d4f3e350SEd Wildgoose	---help---
2742d4f3e350SEd Wildgoose	  This option enables system support for the PCEngines ALIX.
2743d4f3e350SEd Wildgoose	  At present this just sets up LEDs for GPIO control on
2744d4f3e350SEd Wildgoose	  ALIX2/3/6 boards.  However, other system specific setup should
2745d4f3e350SEd Wildgoose	  get added here.
2746d4f3e350SEd Wildgoose
2747d4f3e350SEd Wildgoose	  Note: You must still enable the drivers for GPIO and LED support
2748d4f3e350SEd Wildgoose	  (GPIO_CS5535 & LEDS_GPIO) to actually use the LEDs
2749d4f3e350SEd Wildgoose
2750d4f3e350SEd Wildgoose	  Note: You have to set alix.force=1 for boards with Award BIOS.
2751d4f3e350SEd Wildgoose
2752da4e3302SPhilip Prindevilleconfig NET5501
2753da4e3302SPhilip Prindeville	bool "Soekris Engineering net5501 System Support (LEDS, GPIO, etc)"
2754da4e3302SPhilip Prindeville	select GPIOLIB
2755da4e3302SPhilip Prindeville	---help---
2756da4e3302SPhilip Prindeville	  This option enables system support for the Soekris Engineering net5501.
2757da4e3302SPhilip Prindeville
27583197059aSPhilip A. Prindevilleconfig GEOS
27593197059aSPhilip A. Prindeville	bool "Traverse Technologies GEOS System Support (LEDS, GPIO, etc)"
27603197059aSPhilip A. Prindeville	select GPIOLIB
27613197059aSPhilip A. Prindeville	depends on DMI
27623197059aSPhilip A. Prindeville	---help---
27633197059aSPhilip A. Prindeville	  This option enables system support for the Traverse Technologies GEOS.
27643197059aSPhilip A. Prindeville
27657d029125SVivien Didelotconfig TS5500
27667d029125SVivien Didelot	bool "Technologic Systems TS-5500 platform support"
27677d029125SVivien Didelot	depends on MELAN
27687d029125SVivien Didelot	select CHECK_SIGNATURE
27697d029125SVivien Didelot	select NEW_LEDS
27707d029125SVivien Didelot	select LEDS_CLASS
27717d029125SVivien Didelot	---help---
27727d029125SVivien Didelot	  This option enables system support for the Technologic Systems TS-5500.
27737d029125SVivien Didelot
2774e279b6c1SSam Ravnborgendif # X86_32
2775e279b6c1SSam Ravnborg
277623ac4ae8SAndreas Herrmannconfig AMD_NB
2777e279b6c1SSam Ravnborg	def_bool y
27780e152cd7SBorislav Petkov	depends on CPU_SUP_AMD && PCI
2779e279b6c1SSam Ravnborg
2780e3263ab3SDavid Herrmannconfig X86_SYSFB
2781e3263ab3SDavid Herrmann	bool "Mark VGA/VBE/EFI FB as generic system framebuffer"
2782e3263ab3SDavid Herrmann	help
2783e3263ab3SDavid Herrmann	  Firmwares often provide initial graphics framebuffers so the BIOS,
2784e3263ab3SDavid Herrmann	  bootloader or kernel can show basic video-output during boot for
2785e3263ab3SDavid Herrmann	  user-guidance and debugging. Historically, x86 used the VESA BIOS
2786e3263ab3SDavid Herrmann	  Extensions and EFI-framebuffers for this, which are mostly limited
2787e3263ab3SDavid Herrmann	  to x86.
2788e3263ab3SDavid Herrmann	  This option, if enabled, marks VGA/VBE/EFI framebuffers as generic
2789e3263ab3SDavid Herrmann	  framebuffers so the new generic system-framebuffer drivers can be
2790e3263ab3SDavid Herrmann	  used on x86. If the framebuffer is not compatible with the generic
2791e3a5dc08SNikolas Nyby	  modes, it is advertised as fallback platform framebuffer so legacy
2792e3263ab3SDavid Herrmann	  drivers like efifb, vesafb and uvesafb can pick it up.
2793e3263ab3SDavid Herrmann	  If this option is not selected, all system framebuffers are always
2794e3263ab3SDavid Herrmann	  marked as fallback platform framebuffers as usual.
2795e3263ab3SDavid Herrmann
2796e3263ab3SDavid Herrmann	  Note: Legacy fbdev drivers, including vesafb, efifb, uvesafb, will
2797e3263ab3SDavid Herrmann	  not be able to pick up generic system framebuffers if this option
2798e3263ab3SDavid Herrmann	  is selected. You are highly encouraged to enable simplefb as
2799e3263ab3SDavid Herrmann	  replacement if you select this option. simplefb can correctly deal
2800e3263ab3SDavid Herrmann	  with generic system framebuffers. But you should still keep vesafb
2801e3263ab3SDavid Herrmann	  and others enabled as fallback if a system framebuffer is
2802e3263ab3SDavid Herrmann	  incompatible with simplefb.
2803e3263ab3SDavid Herrmann
2804e3263ab3SDavid Herrmann	  If unsure, say Y.
2805e3263ab3SDavid Herrmann
2806e279b6c1SSam Ravnborgendmenu
2807e279b6c1SSam Ravnborg
2808e279b6c1SSam Ravnborg
28091572497cSChristoph Hellwigmenu "Binary Emulations"
2810e279b6c1SSam Ravnborg
2811e279b6c1SSam Ravnborgconfig IA32_EMULATION
2812e279b6c1SSam Ravnborg	bool "IA32 Emulation"
2813e279b6c1SSam Ravnborg	depends on X86_64
281439f88911SIngo Molnar	select ARCH_WANT_OLD_COMPAT_IPC
2815d1603990SRandy Dunlap	select BINFMT_ELF
2816a97f52e6SRoland McGrath	select COMPAT_BINFMT_ELF
281739f88911SIngo Molnar	select COMPAT_OLD_SIGACTION
28188f9ca475SIngo Molnar	---help---
28195fd92e65SH. J. Lu	  Include code to run legacy 32-bit programs under a
28205fd92e65SH. J. Lu	  64-bit kernel. You should likely turn this on, unless you're
28215fd92e65SH. J. Lu	  100% sure that you don't have any 32-bit programs left.
2822e279b6c1SSam Ravnborg
2823e279b6c1SSam Ravnborgconfig IA32_AOUT
2824e279b6c1SSam Ravnborg	tristate "IA32 a.out support"
28256b213e1bSDavid Woodhouse	depends on IA32_EMULATION
2826eac61655SBorislav Petkov	depends on BROKEN
28278f9ca475SIngo Molnar	---help---
2828e279b6c1SSam Ravnborg	  Support old a.out binaries in the 32bit emulation.
2829e279b6c1SSam Ravnborg
28300bf62763SH. Peter Anvinconfig X86_X32
28316ea30386SKees Cook	bool "x32 ABI for 64-bit mode"
28329b54050bSBrian Gerst	depends on X86_64
28335fd92e65SH. J. Lu	---help---
28345fd92e65SH. J. Lu	  Include code to run binaries for the x32 native 32-bit ABI
28355fd92e65SH. J. Lu	  for 64-bit processors.  An x32 process gets access to the
28365fd92e65SH. J. Lu	  full 64-bit register file and wide data path while leaving
28375fd92e65SH. J. Lu	  pointers at 32 bits for smaller memory footprint.
28385fd92e65SH. J. Lu
28395fd92e65SH. J. Lu	  You will need a recent binutils (2.22 or later) with
28405fd92e65SH. J. Lu	  elf32_x86_64 support enabled to compile a kernel with this
28415fd92e65SH. J. Lu	  option set.
28425fd92e65SH. J. Lu
2843953fee1dSIngo Molnarconfig COMPAT_32
2844953fee1dSIngo Molnar	def_bool y
2845953fee1dSIngo Molnar	depends on IA32_EMULATION || X86_32
2846953fee1dSIngo Molnar	select HAVE_UID16
2847953fee1dSIngo Molnar	select OLD_SIGSUSPEND3
2848953fee1dSIngo Molnar
2849e279b6c1SSam Ravnborgconfig COMPAT
28503c2362e6SHarvey Harrison	def_bool y
28510bf62763SH. Peter Anvin	depends on IA32_EMULATION || X86_X32
2852e279b6c1SSam Ravnborg
28533120e25eSJan Beulichif COMPAT
2854e279b6c1SSam Ravnborgconfig COMPAT_FOR_U64_ALIGNMENT
28553120e25eSJan Beulich	def_bool y
2856e279b6c1SSam Ravnborg
2857e279b6c1SSam Ravnborgconfig SYSVIPC_COMPAT
28583c2362e6SHarvey Harrison	def_bool y
28593120e25eSJan Beulich	depends on SYSVIPC
28603120e25eSJan Beulichendif
2861ee009e4aSDavid Howells
2862e279b6c1SSam Ravnborgendmenu
2863e279b6c1SSam Ravnborg
2864e279b6c1SSam Ravnborg
2865e5beae16SKeith Packardconfig HAVE_ATOMIC_IOMAP
2866e5beae16SKeith Packard	def_bool y
2867e5beae16SKeith Packard	depends on X86_32
2868e5beae16SKeith Packard
28694692d77fSAlessandro Rubiniconfig X86_DEV_DMA_OPS
28704692d77fSAlessandro Rubini	bool
2871f7219a53SAlessandro Rubini
2872e585513bSKirill A. Shutemovconfig HAVE_GENERIC_GUP
2873e585513bSKirill A. Shutemov	def_bool y
2874e585513bSKirill A. Shutemov
2875e279b6c1SSam Ravnborgsource "drivers/firmware/Kconfig"
2876e279b6c1SSam Ravnborg
2877edf88417SAvi Kivitysource "arch/x86/kvm/Kconfig"
2878