xref: /linux/arch/x86/Kconfig (revision afaef01c001537fa97a25092d7f54d764dc7d8c1)
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
17341c787eSIngo Molnar	select HAVE_AOUT
18341c787eSIngo Molnar	select HAVE_GENERIC_DMA_COHERENT
19341c787eSIngo Molnar	select MODULES_USE_ELF_REL
20341c787eSIngo Molnar	select OLD_SIGACTION
21daa93fabSSam Ravnborg
22daa93fabSSam Ravnborgconfig X86_64
233120e25eSJan Beulich	def_bool y
243120e25eSJan Beulich	depends on 64BIT
25d94e0685SIngo Molnar	# Options that are inherently 64-bit kernel only:
26e1073d1eSAneesh Kumar K.V	select ARCH_HAS_GIGANTIC_PAGE if (MEMORY_ISOLATION && COMPACTION) || CMA
27d94e0685SIngo Molnar	select ARCH_SUPPORTS_INT128
28d94e0685SIngo Molnar	select ARCH_USE_CMPXCHG_LOCKREF
29d94e0685SIngo Molnar	select HAVE_ARCH_SOFT_DIRTY
30d94e0685SIngo Molnar	select MODULES_USE_ELF_RELA
31f616ab59SChristoph Hellwig	select NEED_DMA_MAP_STATE
3209230cbcSChristoph Hellwig	select SWIOTLB
33d94e0685SIngo Molnar	select X86_DEV_DMA_OPS
34f8781c4aSDominik Brodowski	select ARCH_HAS_SYSCALL_WRAPPER
351032c0baSSam Ravnborg
36d94e0685SIngo Molnar#
37d94e0685SIngo Molnar# Arch settings
38d94e0685SIngo Molnar#
39d94e0685SIngo Molnar# ( Note that options that are marked 'if X86_64' could in principle be
40d94e0685SIngo Molnar#   ported to 32-bit as well. )
41d94e0685SIngo Molnar#
428d5fffb9SSam Ravnborgconfig X86
433c2362e6SHarvey Harrison	def_bool y
44c763ea26SIngo Molnar	#
45c763ea26SIngo Molnar	# Note: keep this list sorted alphabetically
46c763ea26SIngo Molnar	#
476471b825SIngo Molnar	select ACPI_LEGACY_TABLES_LOOKUP	if ACPI
486e0a0ea1SGraeme Gregory	select ACPI_SYSTEM_POWER_STATES_SUPPORT	if ACPI
496471b825SIngo Molnar	select ANON_INODES
506471b825SIngo Molnar	select ARCH_CLOCKSOURCE_DATA
516471b825SIngo Molnar	select ARCH_DISCARD_MEMBLOCK
5291dda51aSAleksey Makarov	select ARCH_HAS_ACPI_TABLE_UPGRADE	if ACPI
53fa5b6ec9SLaura Abbott	select ARCH_HAS_DEBUG_VIRTUAL
5421266be9SDan Williams	select ARCH_HAS_DEVMEM_IS_ALLOWED
556471b825SIngo Molnar	select ARCH_HAS_ELF_RANDOMIZE
5672d93104SLinus Torvalds	select ARCH_HAS_FAST_MULTIPLIER
57316d097cSDave Hansen	select ARCH_HAS_FILTER_PGPROT
586974f0c4SDaniel Micay	select ARCH_HAS_FORTIFY_SOURCE
59957e3facSRiku Voipio	select ARCH_HAS_GCOV_PROFILE_ALL
605c9a8750SDmitry Vyukov	select ARCH_HAS_KCOV			if X86_64
6110bcc80eSMathieu Desnoyers	select ARCH_HAS_MEMBARRIER_SYNC_CORE
62c763ea26SIngo Molnar	select ARCH_HAS_PMEM_API		if X86_64
633010a5eaSLaurent Dufour	select ARCH_HAS_PTE_SPECIAL
6439208aa7SKees Cook	select ARCH_HAS_REFCOUNT
650aed55afSDan Williams	select ARCH_HAS_UACCESS_FLUSHCACHE	if X86_64
66092b31aaSDan Williams	select ARCH_HAS_UACCESS_MCSAFE		if X86_64 && X86_MCE
67d2852a22SDaniel Borkmann	select ARCH_HAS_SET_MEMORY
686471b825SIngo Molnar	select ARCH_HAS_SG_CHAIN
69ad21fc4fSLaura Abbott	select ARCH_HAS_STRICT_KERNEL_RWX
70ad21fc4fSLaura Abbott	select ARCH_HAS_STRICT_MODULE_RWX
71ac1ab12aSMathieu Desnoyers	select ARCH_HAS_SYNC_CORE_BEFORE_USERMODE
72c6d30853SAndrey Ryabinin	select ARCH_HAS_UBSAN_SANITIZE_ALL
7365f7d049SOliver O'Halloran	select ARCH_HAS_ZONE_DEVICE		if X86_64
746471b825SIngo Molnar	select ARCH_HAVE_NMI_SAFE_CMPXCHG
756471b825SIngo Molnar	select ARCH_MIGHT_HAVE_ACPI_PDC		if ACPI
7677fbbc81SMark Salter	select ARCH_MIGHT_HAVE_PC_PARPORT
775e2c18c0SMark Salter	select ARCH_MIGHT_HAVE_PC_SERIO
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
92fec777c3SChristoph Hellwig	select DMA_DIRECT_OPS
9345471cd9SLinus Torvalds	select EDAC_ATOMIC_SCRUB
9445471cd9SLinus Torvalds	select EDAC_SUPPORT
956471b825SIngo Molnar	select GENERIC_CLOCKEVENTS
966471b825SIngo Molnar	select GENERIC_CLOCKEVENTS_BROADCAST	if X86_64 || (X86_32 && X86_LOCAL_APIC)
976471b825SIngo Molnar	select GENERIC_CLOCKEVENTS_MIN_ADJUST
986471b825SIngo Molnar	select GENERIC_CMOS_UPDATE
996471b825SIngo Molnar	select GENERIC_CPU_AUTOPROBE
10061dc0f55SThomas Gleixner	select GENERIC_CPU_VULNERABILITIES
1016471b825SIngo Molnar	select GENERIC_EARLY_IOREMAP
1026471b825SIngo Molnar	select GENERIC_FIND_FIRST_BIT
1036471b825SIngo Molnar	select GENERIC_IOMAP
104c7d6c9ddSThomas Gleixner	select GENERIC_IRQ_EFFECTIVE_AFF_MASK	if SMP
1050fa115daSThomas Gleixner	select GENERIC_IRQ_MATRIX_ALLOCATOR	if X86_LOCAL_APIC
106ad7a929fSThomas Gleixner	select GENERIC_IRQ_MIGRATION		if SMP
1076471b825SIngo Molnar	select GENERIC_IRQ_PROBE
108c201c917SThomas Gleixner	select GENERIC_IRQ_RESERVATION_MODE
1096471b825SIngo Molnar	select GENERIC_IRQ_SHOW
1106471b825SIngo Molnar	select GENERIC_PENDING_IRQ		if SMP
1116471b825SIngo Molnar	select GENERIC_SMP_IDLE_THREAD
1126471b825SIngo Molnar	select GENERIC_STRNCPY_FROM_USER
1136471b825SIngo Molnar	select GENERIC_STRNLEN_USER
1146471b825SIngo Molnar	select GENERIC_TIME_VSYSCALL
1157edaeb68SThomas Gleixner	select HARDLOCKUP_CHECK_TIMESTAMP	if X86_64
1166471b825SIngo Molnar	select HAVE_ACPI_APEI			if ACPI
1176471b825SIngo Molnar	select HAVE_ACPI_APEI_NMI		if ACPI
1186471b825SIngo Molnar	select HAVE_ALIGNED_STRUCT_PAGE		if SLUB
1196471b825SIngo Molnar	select HAVE_ARCH_AUDITSYSCALL
1206471b825SIngo Molnar	select HAVE_ARCH_HUGE_VMAP		if X86_64 || X86_PAE
1216471b825SIngo Molnar	select HAVE_ARCH_JUMP_LABEL
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
130*afaef01cSAlexander 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
1426471b825SIngo Molnar	select HAVE_DEBUG_STACKOVERFLOW
1439c5a3621SAkinobu Mita	select HAVE_DMA_CONTIGUOUS
144677aa9f7SSteven Rostedt	select HAVE_DYNAMIC_FTRACE
14506aeaaeaSMasami Hiramatsu	select HAVE_DYNAMIC_FTRACE_WITH_REGS
14603f5781bSWang YanQing	select HAVE_EBPF_JIT
14758340a07SJohannes Berg	select HAVE_EFFICIENT_UNALIGNED_ACCESS
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
1726471b825SIngo Molnar	select HAVE_MEMBLOCK_NODE_MAP
1730102752eSFrederic Weisbecker	select HAVE_MIXED_BREAKPOINTS_REGS
174ee9f8fceSJosh Poimboeuf	select HAVE_MOD_ARCH_SPECIFIC
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
182c5e63197SJiri Olsa	select HAVE_PERF_REGS
183c5ebcedbSJiri Olsa	select HAVE_PERF_USER_STACK_DUMP
18448a8b97cSPeter Zijlstra	select HAVE_RCU_TABLE_FREE		if PARAVIRT
185d86564a2SPeter Zijlstra	select HAVE_RCU_TABLE_INVALIDATE	if HAVE_RCU_TABLE_FREE
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
188d148eac0SMasahiro Yamada	select HAVE_STACKPROTECTOR		if CC_HAS_SANE_STACKPROTECTOR
189c763ea26SIngo Molnar	select HAVE_STACK_VALIDATION		if X86_64
190d6761b8fSMathieu Desnoyers	select HAVE_RSEQ
1916471b825SIngo Molnar	select HAVE_SYSCALL_TRACEPOINTS
1926471b825SIngo Molnar	select HAVE_UNSTABLE_SCHED_CLOCK
1937c68af6eSAvi Kivity	select HAVE_USER_RETURN_NOTIFIER
19405736e4aSThomas Gleixner	select HOTPLUG_SMT			if SMP
195c0185808SThomas Gleixner	select IRQ_FORCED_THREADING
19686596f0aSChristoph Hellwig	select NEED_SG_DMA_LENGTH
197df65c1bcSThomas Gleixner	select PCI_LOCKLESS_CONFIG
1986471b825SIngo Molnar	select PERF_EVENTS
1993195ef59SPrarit Bhargava	select RTC_LIB
200d6faca40SArnd Bergmann	select RTC_MC146818_LIB
2016471b825SIngo Molnar	select SPARSE_IRQ
20283fe27eaSPranith Kumar	select SRCU
2036471b825SIngo Molnar	select SYSCTL_EXCEPTION_TRACE
20415f4eae7SAndy Lutomirski	select THREAD_INFO_IN_TASK
2056471b825SIngo Molnar	select USER_STACKTRACE_SUPPORT
2066471b825SIngo Molnar	select VIRT_TO_BUS
2076471b825SIngo Molnar	select X86_FEATURE_NAMES		if PROC_FS
2087d8330a5SBalbir Singh
209ba7e4d13SIngo Molnarconfig INSTRUCTION_DECODER
2103120e25eSJan Beulich	def_bool y
2113120e25eSJan Beulich	depends on KPROBES || PERF_EVENTS || UPROBES
212ba7e4d13SIngo Molnar
21351b26adaSLinus Torvaldsconfig OUTPUT_FORMAT
21451b26adaSLinus Torvalds	string
21551b26adaSLinus Torvalds	default "elf32-i386" if X86_32
21651b26adaSLinus Torvalds	default "elf64-x86-64" if X86_64
21751b26adaSLinus Torvalds
21873531905SSam Ravnborgconfig ARCH_DEFCONFIG
219b9b39bfbSSam Ravnborg	string
22073531905SSam Ravnborg	default "arch/x86/configs/i386_defconfig" if X86_32
22173531905SSam Ravnborg	default "arch/x86/configs/x86_64_defconfig" if X86_64
222b9b39bfbSSam Ravnborg
2238d5fffb9SSam Ravnborgconfig LOCKDEP_SUPPORT
2243c2362e6SHarvey Harrison	def_bool y
2258d5fffb9SSam Ravnborg
2268d5fffb9SSam Ravnborgconfig STACKTRACE_SUPPORT
2273c2362e6SHarvey Harrison	def_bool y
2288d5fffb9SSam Ravnborg
2298d5fffb9SSam Ravnborgconfig MMU
2303c2362e6SHarvey Harrison	def_bool y
2318d5fffb9SSam Ravnborg
2329e08f57dSDaniel Cashmanconfig ARCH_MMAP_RND_BITS_MIN
2339e08f57dSDaniel Cashman	default 28 if 64BIT
2349e08f57dSDaniel Cashman	default 8
2359e08f57dSDaniel Cashman
2369e08f57dSDaniel Cashmanconfig ARCH_MMAP_RND_BITS_MAX
2379e08f57dSDaniel Cashman	default 32 if 64BIT
2389e08f57dSDaniel Cashman	default 16
2399e08f57dSDaniel Cashman
2409e08f57dSDaniel Cashmanconfig ARCH_MMAP_RND_COMPAT_BITS_MIN
2419e08f57dSDaniel Cashman	default 8
2429e08f57dSDaniel Cashman
2439e08f57dSDaniel Cashmanconfig ARCH_MMAP_RND_COMPAT_BITS_MAX
2449e08f57dSDaniel Cashman	default 16
2459e08f57dSDaniel Cashman
2468d5fffb9SSam Ravnborgconfig SBUS
2478d5fffb9SSam Ravnborg	bool
2488d5fffb9SSam Ravnborg
2498d5fffb9SSam Ravnborgconfig GENERIC_ISA_DMA
2503120e25eSJan Beulich	def_bool y
2513120e25eSJan Beulich	depends on ISA_DMA_API
2528d5fffb9SSam Ravnborg
2538d5fffb9SSam Ravnborgconfig GENERIC_BUG
2543c2362e6SHarvey Harrison	def_bool y
2558d5fffb9SSam Ravnborg	depends on BUG
256b93a531eSJan Beulich	select GENERIC_BUG_RELATIVE_POINTERS if X86_64
257b93a531eSJan Beulich
258b93a531eSJan Beulichconfig GENERIC_BUG_RELATIVE_POINTERS
259b93a531eSJan Beulich	bool
2608d5fffb9SSam Ravnborg
2618d5fffb9SSam Ravnborgconfig GENERIC_HWEIGHT
2623c2362e6SHarvey Harrison	def_bool y
2638d5fffb9SSam Ravnborg
2648d5fffb9SSam Ravnborgconfig ARCH_MAY_HAVE_PC_FDC
2653120e25eSJan Beulich	def_bool y
2663120e25eSJan Beulich	depends on ISA_DMA_API
2678d5fffb9SSam Ravnborg
2681032c0baSSam Ravnborgconfig RWSEM_XCHGADD_ALGORITHM
2693120e25eSJan Beulich	def_bool y
2701032c0baSSam Ravnborg
2711032c0baSSam Ravnborgconfig GENERIC_CALIBRATE_DELAY
2721032c0baSSam Ravnborg	def_bool y
2731032c0baSSam Ravnborg
2749a0b8415Svenkatesh.pallipadi@intel.comconfig ARCH_HAS_CPU_RELAX
2759a0b8415Svenkatesh.pallipadi@intel.com	def_bool y
2768d5fffb9SSam Ravnborg
2771b27d05bSPekka Enbergconfig ARCH_HAS_CACHE_LINE_SIZE
2781b27d05bSPekka Enberg	def_bool y
2791b27d05bSPekka Enberg
280316d097cSDave Hansenconfig ARCH_HAS_FILTER_PGPROT
281316d097cSDave Hansen	def_bool y
282316d097cSDave Hansen
283dd5af90aSMike Travisconfig HAVE_SETUP_PER_CPU_AREA
28489c9c4c5SBrian Gerst	def_bool y
285b32ef636Stravis@sgi.com
28608fc4580STejun Heoconfig NEED_PER_CPU_EMBED_FIRST_CHUNK
28708fc4580STejun Heo	def_bool y
28808fc4580STejun Heo
28908fc4580STejun Heoconfig NEED_PER_CPU_PAGE_FIRST_CHUNK
29011124411STejun Heo	def_bool y
29111124411STejun Heo
292801e4062SJohannes Bergconfig ARCH_HIBERNATION_POSSIBLE
293801e4062SJohannes Berg	def_bool y
294801e4062SJohannes Berg
295f4cb5700SJohannes Bergconfig ARCH_SUSPEND_POSSIBLE
296f4cb5700SJohannes Berg	def_bool y
297f4cb5700SJohannes Berg
298cfe28c5dSSteve Capperconfig ARCH_WANT_HUGE_PMD_SHARE
299cfe28c5dSSteve Capper	def_bool y
300cfe28c5dSSteve Capper
30153313b2cSSteve Capperconfig ARCH_WANT_GENERAL_HUGETLB
30253313b2cSSteve Capper	def_bool y
30353313b2cSSteve Capper
3048d5fffb9SSam Ravnborgconfig ZONE_DMA32
305e0fd24a3SJan Beulich	def_bool y if X86_64
3068d5fffb9SSam Ravnborg
3078d5fffb9SSam Ravnborgconfig AUDIT_ARCH
308e0fd24a3SJan Beulich	def_bool y if X86_64
3098d5fffb9SSam Ravnborg
310765c68bdSIngo Molnarconfig ARCH_SUPPORTS_OPTIMIZED_INLINING
311765c68bdSIngo Molnar	def_bool y
312765c68bdSIngo Molnar
3136a11f75bSAkinobu Mitaconfig ARCH_SUPPORTS_DEBUG_PAGEALLOC
3146a11f75bSAkinobu Mita	def_bool y
3156a11f75bSAkinobu Mita
316d6f2d75aSAndrey Ryabininconfig KASAN_SHADOW_OFFSET
317d6f2d75aSAndrey Ryabinin	hex
318d6f2d75aSAndrey Ryabinin	depends on KASAN
319d6f2d75aSAndrey Ryabinin	default 0xdffffc0000000000
320d6f2d75aSAndrey Ryabinin
32169575d38SShane Wangconfig HAVE_INTEL_TXT
32269575d38SShane Wang	def_bool y
3236ea30386SKees Cook	depends on INTEL_IOMMU && ACPI
32469575d38SShane Wang
3256b0c3d44SSam Ravnborgconfig X86_32_SMP
3266b0c3d44SSam Ravnborg	def_bool y
3276b0c3d44SSam Ravnborg	depends on X86_32 && SMP
3286b0c3d44SSam Ravnborg
3296b0c3d44SSam Ravnborgconfig X86_64_SMP
3306b0c3d44SSam Ravnborg	def_bool y
3316b0c3d44SSam Ravnborg	depends on X86_64 && SMP
3326b0c3d44SSam Ravnborg
333ccbeed3aSTejun Heoconfig X86_32_LAZY_GS
334ccbeed3aSTejun Heo	def_bool y
3358458f8c2SMasahiro Yamada	depends on X86_32 && !STACKPROTECTOR
336ccbeed3aSTejun Heo
3372b144498SSrikar Dronamrajuconfig ARCH_SUPPORTS_UPROBES
3382b144498SSrikar Dronamraju	def_bool y
3392b144498SSrikar Dronamraju
340d20642f0SRob Herringconfig FIX_EARLYCON_MEM
341d20642f0SRob Herring	def_bool y
342d20642f0SRob Herring
34394d49eb3SKirill A. Shutemovconfig DYNAMIC_PHYSICAL_MASK
34494d49eb3SKirill A. Shutemov	bool
34594d49eb3SKirill A. Shutemov
34698233368SKirill A. Shutemovconfig PGTABLE_LEVELS
34798233368SKirill A. Shutemov	int
34877ef56e4SKirill A. Shutemov	default 5 if X86_5LEVEL
34998233368SKirill A. Shutemov	default 4 if X86_64
35098233368SKirill A. Shutemov	default 3 if X86_PAE
35198233368SKirill A. Shutemov	default 2
35298233368SKirill A. Shutemov
3532a61f474SMasahiro Yamadaconfig CC_HAS_SANE_STACKPROTECTOR
3542a61f474SMasahiro Yamada	bool
3552a61f474SMasahiro Yamada	default $(success,$(srctree)/scripts/gcc-x86_64-has-stack-protector.sh $(CC)) if 64BIT
3562a61f474SMasahiro Yamada	default $(success,$(srctree)/scripts/gcc-x86_32-has-stack-protector.sh $(CC))
3572a61f474SMasahiro Yamada	help
3582a61f474SMasahiro Yamada	   We have to make sure stack protector is unconditionally disabled if
3592a61f474SMasahiro Yamada	   the compiler produces broken code.
3602a61f474SMasahiro Yamada
361506f1d07SSam Ravnborgmenu "Processor type and features"
362506f1d07SSam Ravnborg
3635ee71535SRandy Dunlapconfig ZONE_DMA
3645ee71535SRandy Dunlap	bool "DMA memory allocation support" if EXPERT
3655ee71535SRandy Dunlap	default y
3665ee71535SRandy Dunlap	help
3675ee71535SRandy Dunlap	  DMA memory allocation support allows devices with less than 32-bit
3685ee71535SRandy Dunlap	  addressing to allocate within the first 16MB of address space.
3695ee71535SRandy Dunlap	  Disable if no such devices will be used.
3705ee71535SRandy Dunlap
3715ee71535SRandy Dunlap	  If unsure, say Y.
3725ee71535SRandy Dunlap
373506f1d07SSam Ravnborgconfig SMP
374506f1d07SSam Ravnborg	bool "Symmetric multi-processing support"
375506f1d07SSam Ravnborg	---help---
376506f1d07SSam Ravnborg	  This enables support for systems with more than one CPU. If you have
3774a474157SRobert Graffham	  a system with only one CPU, say N. If you have a system with more
3784a474157SRobert Graffham	  than one CPU, say Y.
379506f1d07SSam Ravnborg
3804a474157SRobert Graffham	  If you say N here, the kernel will run on uni- and multiprocessor
381506f1d07SSam Ravnborg	  machines, but will use only one CPU of a multiprocessor machine. If
382506f1d07SSam Ravnborg	  you say Y here, the kernel will run on many, but not all,
3834a474157SRobert Graffham	  uniprocessor machines. On a uniprocessor machine, the kernel
384506f1d07SSam Ravnborg	  will run faster if you say N here.
385506f1d07SSam Ravnborg
386506f1d07SSam Ravnborg	  Note that if you say Y here and choose architecture "586" or
387506f1d07SSam Ravnborg	  "Pentium" under "Processor family", the kernel will not work on 486
388506f1d07SSam Ravnborg	  architectures. Similarly, multiprocessor kernels for the "PPro"
389506f1d07SSam Ravnborg	  architecture may not work on all Pentium based boards.
390506f1d07SSam Ravnborg
391506f1d07SSam Ravnborg	  People using multiprocessor machines who say Y here should also say
392506f1d07SSam Ravnborg	  Y to "Enhanced Real Time Clock Support", below. The "Advanced Power
393506f1d07SSam Ravnborg	  Management" code will be disabled if you say Y here.
394506f1d07SSam Ravnborg
395395cf969SPaul Bolle	  See also <file:Documentation/x86/i386/IO-APIC.txt>,
396c9525a3fSBenjamin Peterson	  <file:Documentation/lockup-watchdogs.txt> and the SMP-HOWTO available at
397506f1d07SSam Ravnborg	  <http://www.tldp.org/docs.html#howto>.
398506f1d07SSam Ravnborg
399506f1d07SSam Ravnborg	  If you don't know what to do here, say N.
400506f1d07SSam Ravnborg
4019def39beSJosh Triplettconfig X86_FEATURE_NAMES
4029def39beSJosh Triplett	bool "Processor feature human-readable names" if EMBEDDED
4039def39beSJosh Triplett	default y
4049def39beSJosh Triplett	---help---
4059def39beSJosh Triplett	  This option compiles in a table of x86 feature bits and corresponding
4069def39beSJosh Triplett	  names.  This is required to support /proc/cpuinfo and a few kernel
4079def39beSJosh Triplett	  messages.  You can disable this to save space, at the expense of
4089def39beSJosh Triplett	  making those few kernel messages show numeric feature bits instead.
4099def39beSJosh Triplett
4109def39beSJosh Triplett	  If in doubt, say Y.
4119def39beSJosh Triplett
41206cd9a7dSYinghai Luconfig X86_X2APIC
41306cd9a7dSYinghai Lu	bool "Support x2apic"
41419e3d60dSJan Kiszka	depends on X86_LOCAL_APIC && X86_64 && (IRQ_REMAP || HYPERVISOR_GUEST)
41506cd9a7dSYinghai Lu	---help---
41606cd9a7dSYinghai Lu	  This enables x2apic support on CPUs that have this feature.
41706cd9a7dSYinghai Lu
41806cd9a7dSYinghai Lu	  This allows 32-bit apic IDs (so it can support very large systems),
41906cd9a7dSYinghai Lu	  and accesses the local apic via MSRs not via mmio.
42006cd9a7dSYinghai Lu
42106cd9a7dSYinghai Lu	  If you don't know what to do here, say N.
42206cd9a7dSYinghai Lu
4236695c85bSYinghai Luconfig X86_MPPARSE
4246e87f9b7SBin Gao	bool "Enable MPS table" if ACPI || SFI
4257a527688SJan Beulich	default y
4265ab74722SIngo Molnar	depends on X86_LOCAL_APIC
4278f9ca475SIngo Molnar	---help---
4286695c85bSYinghai Lu	  For old smp systems that do not have proper acpi support. Newer systems
4296695c85bSYinghai Lu	  (esp with 64bit cpus) with acpi support, MADT and DSDT will override it
4306695c85bSYinghai Lu
431ddd70cf9SJun Nakajimaconfig GOLDFISH
432ddd70cf9SJun Nakajima       def_bool y
433ddd70cf9SJun Nakajima       depends on X86_GOLDFISH
434ddd70cf9SJun Nakajima
43576b04384SDavid Woodhouseconfig RETPOLINE
43676b04384SDavid Woodhouse	bool "Avoid speculative indirect branches in kernel"
43776b04384SDavid Woodhouse	default y
438d5028ba8SPeter Zijlstra	select STACK_VALIDATION if HAVE_STACK_VALIDATION
43976b04384SDavid Woodhouse	help
44076b04384SDavid Woodhouse	  Compile kernel with the retpoline compiler options to guard against
44176b04384SDavid Woodhouse	  kernel-to-user data leaks by avoiding speculative indirect
44276b04384SDavid Woodhouse	  branches. Requires a compiler with -mindirect-branch=thunk-extern
44376b04384SDavid Woodhouse	  support for full protection. The kernel may run slower.
44476b04384SDavid Woodhouse
44576b04384SDavid Woodhouse	  Without compiler support, at least indirect branches in assembler
44676b04384SDavid Woodhouse	  code are eliminated. Since this includes the syscall entry path,
44776b04384SDavid Woodhouse	  it is not entirely pointless.
44876b04384SDavid Woodhouse
449f01d7d51SVikas Shivappaconfig INTEL_RDT
450f01d7d51SVikas Shivappa	bool "Intel Resource Director Technology support"
45178e99b4aSFenghua Yu	default n
45278e99b4aSFenghua Yu	depends on X86 && CPU_SUP_INTEL
45359fe5a77SThomas Gleixner	select KERNFS
45478e99b4aSFenghua Yu	help
455f01d7d51SVikas Shivappa	  Select to enable resource allocation and monitoring which are
456f01d7d51SVikas Shivappa	  sub-features of Intel Resource Director Technology(RDT). More
457f01d7d51SVikas Shivappa	  information about RDT can be found in the Intel x86
458f01d7d51SVikas Shivappa	  Architecture Software Developer Manual.
45978e99b4aSFenghua Yu
46078e99b4aSFenghua Yu	  Say N if unsure.
46178e99b4aSFenghua Yu
4628425091fSRavikiran G Thirumalaiif X86_32
463a0d0bb4dSRandy Dunlapconfig X86_BIGSMP
464a0d0bb4dSRandy Dunlap	bool "Support for big SMP systems with more than 8 CPUs"
465a0d0bb4dSRandy Dunlap	depends on SMP
466a0d0bb4dSRandy Dunlap	---help---
467a0d0bb4dSRandy Dunlap	  This option is needed for the systems that have more than 8 CPUs
468a0d0bb4dSRandy Dunlap
469c5c606d9SRavikiran G Thirumalaiconfig X86_EXTENDED_PLATFORM
470c5c606d9SRavikiran G Thirumalai	bool "Support for extended (non-PC) x86 platforms"
471c5c606d9SRavikiran G Thirumalai	default y
4728f9ca475SIngo Molnar	---help---
47306ac8346SIngo Molnar	  If you disable this option then the kernel will only support
47406ac8346SIngo Molnar	  standard PC platforms. (which covers the vast majority of
47506ac8346SIngo Molnar	  systems out there.)
47606ac8346SIngo Molnar
4778425091fSRavikiran G Thirumalai	  If you enable this option then you'll be able to select support
4788425091fSRavikiran G Thirumalai	  for the following (non-PC) 32 bit x86 platforms:
479cb7b8023SBen Hutchings		Goldfish (Android emulator)
4808425091fSRavikiran G Thirumalai		AMD Elan
4818425091fSRavikiran G Thirumalai		RDC R-321x SoC
4828425091fSRavikiran G Thirumalai		SGI 320/540 (Visual Workstation)
48383125a3aSAlessandro Rubini		STA2X11-based (e.g. Northville)
4843f4110a4SThomas Gleixner		Moorestown MID devices
48506ac8346SIngo Molnar
48606ac8346SIngo Molnar	  If you have one of these systems, or if you want to build a
48706ac8346SIngo Molnar	  generic distribution kernel, say Y here - otherwise say N.
4888425091fSRavikiran G Thirumalaiendif
48906ac8346SIngo Molnar
4908425091fSRavikiran G Thirumalaiif X86_64
4918425091fSRavikiran G Thirumalaiconfig X86_EXTENDED_PLATFORM
4928425091fSRavikiran G Thirumalai	bool "Support for extended (non-PC) x86 platforms"
4938425091fSRavikiran G Thirumalai	default y
4948425091fSRavikiran G Thirumalai	---help---
4958425091fSRavikiran G Thirumalai	  If you disable this option then the kernel will only support
4968425091fSRavikiran G Thirumalai	  standard PC platforms. (which covers the vast majority of
4978425091fSRavikiran G Thirumalai	  systems out there.)
4988425091fSRavikiran G Thirumalai
4998425091fSRavikiran G Thirumalai	  If you enable this option then you'll be able to select support
5008425091fSRavikiran G Thirumalai	  for the following (non-PC) 64 bit x86 platforms:
50144b111b5SSteffen Persvold		Numascale NumaChip
5028425091fSRavikiran G Thirumalai		ScaleMP vSMP
5038425091fSRavikiran G Thirumalai		SGI Ultraviolet
5048425091fSRavikiran G Thirumalai
5058425091fSRavikiran G Thirumalai	  If you have one of these systems, or if you want to build a
5068425091fSRavikiran G Thirumalai	  generic distribution kernel, say Y here - otherwise say N.
5078425091fSRavikiran G Thirumalaiendif
508c5c606d9SRavikiran G Thirumalai# This is an alphabetically sorted list of 64 bit extended platforms
509c5c606d9SRavikiran G Thirumalai# Please maintain the alphabetic order if and when there are additions
51044b111b5SSteffen Persvoldconfig X86_NUMACHIP
51144b111b5SSteffen Persvold	bool "Numascale NumaChip"
51244b111b5SSteffen Persvold	depends on X86_64
51344b111b5SSteffen Persvold	depends on X86_EXTENDED_PLATFORM
51444b111b5SSteffen Persvold	depends on NUMA
51544b111b5SSteffen Persvold	depends on SMP
51644b111b5SSteffen Persvold	depends on X86_X2APIC
517f9726bfdSDaniel J Blueman	depends on PCI_MMCONFIG
51844b111b5SSteffen Persvold	---help---
51944b111b5SSteffen Persvold	  Adds support for Numascale NumaChip large-SMP systems. Needed to
52044b111b5SSteffen Persvold	  enable more than ~168 cores.
52144b111b5SSteffen Persvold	  If you don't have one of these, you should say N here.
52203b48632SNick Piggin
5236a48565eSIngo Molnarconfig X86_VSMP
524c5c606d9SRavikiran G Thirumalai	bool "ScaleMP vSMP"
5256276a074SBorislav Petkov	select HYPERVISOR_GUEST
5266a48565eSIngo Molnar	select PARAVIRT
5276a48565eSIngo Molnar	depends on X86_64 && PCI
528c5c606d9SRavikiran G Thirumalai	depends on X86_EXTENDED_PLATFORM
529ead91d4bSShai Fultheim	depends on SMP
5308f9ca475SIngo Molnar	---help---
5316a48565eSIngo Molnar	  Support for ScaleMP vSMP systems.  Say 'Y' here if this kernel is
5326a48565eSIngo Molnar	  supposed to run on these EM64T-based machines.  Only choose this option
5336a48565eSIngo Molnar	  if you have one of these machines.
5346a48565eSIngo Molnar
535c5c606d9SRavikiran G Thirumalaiconfig X86_UV
536c5c606d9SRavikiran G Thirumalai	bool "SGI Ultraviolet"
537c5c606d9SRavikiran G Thirumalai	depends on X86_64
538c5c606d9SRavikiran G Thirumalai	depends on X86_EXTENDED_PLATFORM
53954c28d29SJack Steiner	depends on NUMA
5401ecb4ae5SAndrew Morton	depends on EFI
5419d6c26e7SSuresh Siddha	depends on X86_X2APIC
5421222e564SIngo Molnar	depends on PCI
543c5c606d9SRavikiran G Thirumalai	---help---
544c5c606d9SRavikiran G Thirumalai	  This option is needed in order to support SGI Ultraviolet systems.
545c5c606d9SRavikiran G Thirumalai	  If you don't have one of these, you should say N here.
546c5c606d9SRavikiran G Thirumalai
547c5c606d9SRavikiran G Thirumalai# Following is an alphabetically sorted list of 32 bit extended platforms
548c5c606d9SRavikiran G Thirumalai# Please maintain the alphabetic order if and when there are additions
549506f1d07SSam Ravnborg
550ddd70cf9SJun Nakajimaconfig X86_GOLDFISH
551ddd70cf9SJun Nakajima       bool "Goldfish (Virtual Platform)"
552cb7b8023SBen Hutchings       depends on X86_EXTENDED_PLATFORM
553ddd70cf9SJun Nakajima       ---help---
554ddd70cf9SJun Nakajima	 Enable support for the Goldfish virtual platform used primarily
555ddd70cf9SJun Nakajima	 for Android development. Unless you are building for the Android
556ddd70cf9SJun Nakajima	 Goldfish emulator say N here.
557ddd70cf9SJun Nakajima
558c751e17bSThomas Gleixnerconfig X86_INTEL_CE
559c751e17bSThomas Gleixner	bool "CE4100 TV platform"
560c751e17bSThomas Gleixner	depends on PCI
561c751e17bSThomas Gleixner	depends on PCI_GODIRECT
5626084a6e2SJiang Liu	depends on X86_IO_APIC
563c751e17bSThomas Gleixner	depends on X86_32
564c751e17bSThomas Gleixner	depends on X86_EXTENDED_PLATFORM
56537bc9f50SDirk Brandewie	select X86_REBOOTFIXUPS
566da6b737bSSebastian Andrzej Siewior	select OF
567da6b737bSSebastian Andrzej Siewior	select OF_EARLY_FLATTREE
568c751e17bSThomas Gleixner	---help---
569c751e17bSThomas Gleixner	  Select for the Intel CE media processor (CE4100) SOC.
570c751e17bSThomas Gleixner	  This option compiles in support for the CE4100 SOC for settop
571c751e17bSThomas Gleixner	  boxes and media devices.
572c751e17bSThomas Gleixner
5734cb9b00fSDavid Cohenconfig X86_INTEL_MID
57443605ef1SAlan Cox	bool "Intel MID platform support"
57543605ef1SAlan Cox	depends on X86_EXTENDED_PLATFORM
576edc6bc78SDavid Cohen	depends on X86_PLATFORM_DEVICES
5771ea7c673SAlan Cox	depends on PCI
5783fda5bb4SAndy Shevchenko	depends on X86_64 || (PCI_GOANY && X86_32)
5791ea7c673SAlan Cox	depends on X86_IO_APIC
5807c9c3a1eSAlan Cox	select SFI
5814cb9b00fSDavid Cohen	select I2C
5827c9c3a1eSAlan Cox	select DW_APB_TIMER
5831ea7c673SAlan Cox	select APB_TIMER
5841ea7c673SAlan Cox	select INTEL_SCU_IPC
58515a713dfSMika Westerberg	select MFD_INTEL_MSIC
5861ea7c673SAlan Cox	---help---
5874cb9b00fSDavid Cohen	  Select to build a kernel capable of supporting Intel MID (Mobile
5884cb9b00fSDavid Cohen	  Internet Device) platform systems which do not have the PCI legacy
5894cb9b00fSDavid Cohen	  interfaces. If you are building for a PC class system say N here.
5901ea7c673SAlan Cox
5914cb9b00fSDavid Cohen	  Intel MID platforms are based on an Intel processor and chipset which
5924cb9b00fSDavid Cohen	  consume less power than most of the x86 derivatives.
59343605ef1SAlan Cox
5948bbc2a13SBryan O'Donoghueconfig X86_INTEL_QUARK
5958bbc2a13SBryan O'Donoghue	bool "Intel Quark platform support"
5968bbc2a13SBryan O'Donoghue	depends on X86_32
5978bbc2a13SBryan O'Donoghue	depends on X86_EXTENDED_PLATFORM
5988bbc2a13SBryan O'Donoghue	depends on X86_PLATFORM_DEVICES
5998bbc2a13SBryan O'Donoghue	depends on X86_TSC
6008bbc2a13SBryan O'Donoghue	depends on PCI
6018bbc2a13SBryan O'Donoghue	depends on PCI_GOANY
6028bbc2a13SBryan O'Donoghue	depends on X86_IO_APIC
6038bbc2a13SBryan O'Donoghue	select IOSF_MBI
6048bbc2a13SBryan O'Donoghue	select INTEL_IMR
6059ab6eb51SAndy Shevchenko	select COMMON_CLK
6068bbc2a13SBryan O'Donoghue	---help---
6078bbc2a13SBryan O'Donoghue	  Select to include support for Quark X1000 SoC.
6088bbc2a13SBryan O'Donoghue	  Say Y here if you have a Quark based system such as the Arduino
6098bbc2a13SBryan O'Donoghue	  compatible Intel Galileo.
6108bbc2a13SBryan O'Donoghue
6113d48aab1SMika Westerbergconfig X86_INTEL_LPSS
6123d48aab1SMika Westerberg	bool "Intel Low Power Subsystem Support"
613eebb3e8dSAndy Shevchenko	depends on X86 && ACPI
6143d48aab1SMika Westerberg	select COMMON_CLK
6150f531431SMathias Nyman	select PINCTRL
616eebb3e8dSAndy Shevchenko	select IOSF_MBI
6173d48aab1SMika Westerberg	---help---
6183d48aab1SMika Westerberg	  Select to build support for Intel Low Power Subsystem such as
6193d48aab1SMika Westerberg	  found on Intel Lynxpoint PCH. Selecting this option enables
6200f531431SMathias Nyman	  things like clock tree (common clock framework) and pincontrol
6210f531431SMathias Nyman	  which are needed by the LPSS peripheral drivers.
6223d48aab1SMika Westerberg
62392082a88SKen Xueconfig X86_AMD_PLATFORM_DEVICE
62492082a88SKen Xue	bool "AMD ACPI2Platform devices support"
62592082a88SKen Xue	depends on ACPI
62692082a88SKen Xue	select COMMON_CLK
62792082a88SKen Xue	select PINCTRL
62892082a88SKen Xue	---help---
62992082a88SKen Xue	  Select to interpret AMD specific ACPI device to platform device
63092082a88SKen Xue	  such as I2C, UART, GPIO found on AMD Carrizo and later chipsets.
63192082a88SKen Xue	  I2C and UART depend on COMMON_CLK to set clock. GPIO driver is
63292082a88SKen Xue	  implemented under PINCTRL subsystem.
63392082a88SKen Xue
634ced3ce76SDavid E. Boxconfig IOSF_MBI
635ced3ce76SDavid E. Box	tristate "Intel SoC IOSF Sideband support for SoC platforms"
636ced3ce76SDavid E. Box	depends on PCI
637ced3ce76SDavid E. Box	---help---
638ced3ce76SDavid E. Box	  This option enables sideband register access support for Intel SoC
639ced3ce76SDavid E. Box	  platforms. On these platforms the IOSF sideband is used in lieu of
640ced3ce76SDavid E. Box	  MSR's for some register accesses, mostly but not limited to thermal
641ced3ce76SDavid E. Box	  and power. Drivers may query the availability of this device to
642ced3ce76SDavid E. Box	  determine if they need the sideband in order to work on these
643ced3ce76SDavid E. Box	  platforms. The sideband is available on the following SoC products.
644ced3ce76SDavid E. Box	  This list is not meant to be exclusive.
645ced3ce76SDavid E. Box	   - BayTrail
646ced3ce76SDavid E. Box	   - Braswell
647ced3ce76SDavid E. Box	   - Quark
648ced3ce76SDavid E. Box
649ced3ce76SDavid E. Box	  You should say Y if you are running a kernel on one of these SoC's.
650ced3ce76SDavid E. Box
651ed2226bdSDavid E. Boxconfig IOSF_MBI_DEBUG
652ed2226bdSDavid E. Box	bool "Enable IOSF sideband access through debugfs"
653ed2226bdSDavid E. Box	depends on IOSF_MBI && DEBUG_FS
654ed2226bdSDavid E. Box	---help---
655ed2226bdSDavid E. Box	  Select this option to expose the IOSF sideband access registers (MCR,
656ed2226bdSDavid E. Box	  MDR, MCRX) through debugfs to write and read register information from
657ed2226bdSDavid E. Box	  different units on the SoC. This is most useful for obtaining device
658ed2226bdSDavid E. Box	  state information for debug and analysis. As this is a general access
659ed2226bdSDavid E. Box	  mechanism, users of this option would have specific knowledge of the
660ed2226bdSDavid E. Box	  device they want to access.
661ed2226bdSDavid E. Box
662ed2226bdSDavid E. Box	  If you don't require the option or are in doubt, say N.
663ed2226bdSDavid E. Box
664c5c606d9SRavikiran G Thirumalaiconfig X86_RDC321X
665c5c606d9SRavikiran G Thirumalai	bool "RDC R-321x SoC"
666506f1d07SSam Ravnborg	depends on X86_32
667c5c606d9SRavikiran G Thirumalai	depends on X86_EXTENDED_PLATFORM
668c5c606d9SRavikiran G Thirumalai	select M486
669c5c606d9SRavikiran G Thirumalai	select X86_REBOOTFIXUPS
670c5c606d9SRavikiran G Thirumalai	---help---
671c5c606d9SRavikiran G Thirumalai	  This option is needed for RDC R-321x system-on-chip, also known
672c5c606d9SRavikiran G Thirumalai	  as R-8610-(G).
673c5c606d9SRavikiran G Thirumalai	  If you don't have one of these chips, you should say N here.
674c5c606d9SRavikiran G Thirumalai
675e0c7ae37SIngo Molnarconfig X86_32_NON_STANDARD
6769c398017SIngo Molnar	bool "Support non-standard 32-bit SMP architectures"
6779c398017SIngo Molnar	depends on X86_32 && SMP
678c5c606d9SRavikiran G Thirumalai	depends on X86_EXTENDED_PLATFORM
6798f9ca475SIngo Molnar	---help---
680b5660ba7SH. Peter Anvin	  This option compiles in the bigsmp and STA2X11 default
681b5660ba7SH. Peter Anvin	  subarchitectures.  It is intended for a generic binary
682b5660ba7SH. Peter Anvin	  kernel. If you select them all, kernel will probe it one by
683b5660ba7SH. Peter Anvin	  one and will fallback to default.
684d49c4288SYinghai Lu
685c5c606d9SRavikiran G Thirumalai# Alphabetically sorted list of Non standard 32 bit platforms
686d49c4288SYinghai Lu
687d949f36fSLinus Torvaldsconfig X86_SUPPORTS_MEMORY_FAILURE
6886fc108a0SJan Beulich	def_bool y
689d949f36fSLinus Torvalds	# MCE code calls memory_failure():
690d949f36fSLinus Torvalds	depends on X86_MCE
691d949f36fSLinus Torvalds	# On 32-bit this adds too big of NODES_SHIFT and we run out of page flags:
692d949f36fSLinus Torvalds	# On 32-bit SPARSEMEM adds too big of SECTIONS_WIDTH:
693d949f36fSLinus Torvalds	depends on X86_64 || !SPARSEMEM
694d949f36fSLinus Torvalds	select ARCH_SUPPORTS_MEMORY_FAILURE
695d949f36fSLinus Torvalds
69683125a3aSAlessandro Rubiniconfig STA2X11
69783125a3aSAlessandro Rubini	bool "STA2X11 Companion Chip Support"
69883125a3aSAlessandro Rubini	depends on X86_32_NON_STANDARD && PCI
699b6e05477SChristoph Hellwig	select ARCH_HAS_PHYS_TO_DMA
70083125a3aSAlessandro Rubini	select X86_DEV_DMA_OPS
70183125a3aSAlessandro Rubini	select X86_DMA_REMAP
70283125a3aSAlessandro Rubini	select SWIOTLB
70383125a3aSAlessandro Rubini	select MFD_STA2X11
7040145071bSLinus Walleij	select GPIOLIB
70583125a3aSAlessandro Rubini	default n
70683125a3aSAlessandro Rubini	---help---
70783125a3aSAlessandro Rubini	  This adds support for boards based on the STA2X11 IO-Hub,
70883125a3aSAlessandro Rubini	  a.k.a. "ConneXt". The chip is used in place of the standard
70983125a3aSAlessandro Rubini	  PC chipset, so all "standard" peripherals are missing. If this
71083125a3aSAlessandro Rubini	  option is selected the kernel will still be able to boot on
71183125a3aSAlessandro Rubini	  standard PC machines.
71283125a3aSAlessandro Rubini
71382148d1dSShérabconfig X86_32_IRIS
71482148d1dSShérab	tristate "Eurobraille/Iris poweroff module"
71582148d1dSShérab	depends on X86_32
71682148d1dSShérab	---help---
71782148d1dSShérab	  The Iris machines from EuroBraille do not have APM or ACPI support
71882148d1dSShérab	  to shut themselves down properly.  A special I/O sequence is
71982148d1dSShérab	  needed to do so, which is what this module does at
72082148d1dSShérab	  kernel shutdown.
72182148d1dSShérab
72282148d1dSShérab	  This is only for Iris machines from EuroBraille.
72382148d1dSShérab
72482148d1dSShérab	  If unused, say N.
72582148d1dSShérab
726ae1e9130SIngo Molnarconfig SCHED_OMIT_FRAME_POINTER
7273c2362e6SHarvey Harrison	def_bool y
7283c2362e6SHarvey Harrison	prompt "Single-depth WCHAN output"
729a87d0914SKen Chen	depends on X86
7308f9ca475SIngo Molnar	---help---
731506f1d07SSam Ravnborg	  Calculate simpler /proc/<PID>/wchan values. If this option
732506f1d07SSam Ravnborg	  is disabled then wchan values will recurse back to the
733506f1d07SSam Ravnborg	  caller function. This provides more accurate wchan values,
734506f1d07SSam Ravnborg	  at the expense of slightly more scheduling overhead.
735506f1d07SSam Ravnborg
736506f1d07SSam Ravnborg	  If in doubt, say "Y".
737506f1d07SSam Ravnborg
7386276a074SBorislav Petkovmenuconfig HYPERVISOR_GUEST
7396276a074SBorislav Petkov	bool "Linux guest support"
7408f9ca475SIngo Molnar	---help---
7416276a074SBorislav Petkov	  Say Y here to enable options for running Linux under various hyper-
7426276a074SBorislav Petkov	  visors. This option enables basic hypervisor detection and platform
7436276a074SBorislav Petkov	  setup.
744506f1d07SSam Ravnborg
7456276a074SBorislav Petkov	  If you say N, all options in this submenu will be skipped and
7466276a074SBorislav Petkov	  disabled, and Linux guest support won't be built in.
747506f1d07SSam Ravnborg
7486276a074SBorislav Petkovif HYPERVISOR_GUEST
749506f1d07SSam Ravnborg
750e61bd94aSEduardo Pereira Habkostconfig PARAVIRT
751e61bd94aSEduardo Pereira Habkost	bool "Enable paravirtualization code"
7528f9ca475SIngo Molnar	---help---
753e61bd94aSEduardo Pereira Habkost	  This changes the kernel so it can modify itself when it is run
754e61bd94aSEduardo Pereira Habkost	  under a hypervisor, potentially improving performance significantly
755e61bd94aSEduardo Pereira Habkost	  over full virtualization.  However, when run without a hypervisor
756e61bd94aSEduardo Pereira Habkost	  the kernel is theoretically slower and slightly larger.
757e61bd94aSEduardo Pereira Habkost
7586276a074SBorislav Petkovconfig PARAVIRT_DEBUG
7596276a074SBorislav Petkov	bool "paravirt-ops debugging"
7606276a074SBorislav Petkov	depends on PARAVIRT && DEBUG_KERNEL
7616276a074SBorislav Petkov	---help---
7626276a074SBorislav Petkov	  Enable to debug paravirt_ops internals.  Specifically, BUG if
7636276a074SBorislav Petkov	  a paravirt_op is missing when it is called.
7646276a074SBorislav Petkov
765b4ecc126SJeremy Fitzhardingeconfig PARAVIRT_SPINLOCKS
766b4ecc126SJeremy Fitzhardinge	bool "Paravirtualization layer for spinlocks"
7676ea30386SKees Cook	depends on PARAVIRT && SMP
768b4ecc126SJeremy Fitzhardinge	---help---
769b4ecc126SJeremy Fitzhardinge	  Paravirtualized spinlocks allow a pvops backend to replace the
770b4ecc126SJeremy Fitzhardinge	  spinlock implementation with something virtualization-friendly
771b4ecc126SJeremy Fitzhardinge	  (for example, block the virtual CPU rather than spinning).
772b4ecc126SJeremy Fitzhardinge
7734c4e4f61SRaghavendra K T	  It has a minimal impact on native kernels and gives a nice performance
7744c4e4f61SRaghavendra K T	  benefit on paravirtualized KVM / Xen kernels.
775b4ecc126SJeremy Fitzhardinge
7764c4e4f61SRaghavendra K T	  If you are unsure how to answer this question, answer Y.
777b4ecc126SJeremy Fitzhardinge
77845e898b7SWaiman Longconfig QUEUED_LOCK_STAT
77945e898b7SWaiman Long	bool "Paravirt queued spinlock statistics"
780cfd8983fSPeter Zijlstra	depends on PARAVIRT_SPINLOCKS && DEBUG_FS
78145e898b7SWaiman Long	---help---
78245e898b7SWaiman Long	  Enable the collection of statistical data on the slowpath
78345e898b7SWaiman Long	  behavior of paravirtualized queued spinlocks and report
78445e898b7SWaiman Long	  them on debugfs.
78545e898b7SWaiman Long
7866276a074SBorislav Petkovsource "arch/x86/xen/Kconfig"
7876276a074SBorislav Petkov
7886276a074SBorislav Petkovconfig KVM_GUEST
7896276a074SBorislav Petkov	bool "KVM Guest support (including kvmclock)"
7906276a074SBorislav Petkov	depends on PARAVIRT
7916276a074SBorislav Petkov	select PARAVIRT_CLOCK
7926276a074SBorislav Petkov	default y
7936276a074SBorislav Petkov	---help---
7946276a074SBorislav Petkov	  This option enables various optimizations for running under the KVM
7956276a074SBorislav Petkov	  hypervisor. It includes a paravirtualized clock, so that instead
7966276a074SBorislav Petkov	  of relying on a PIT (or probably other) emulation by the
7976276a074SBorislav Petkov	  underlying device model, the host provides the guest with
7986276a074SBorislav Petkov	  timing infrastructure such as time of day, and system time
7996276a074SBorislav Petkov
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	default n
8041e20eb85SSrivatsa Vaddagiri	---help---
8051e20eb85SSrivatsa Vaddagiri	  This option enables collection of various statistics for KVM guest.
8061e20eb85SSrivatsa Vaddagiri	  Statistics are displayed in debugfs filesystem. Enabling this option
8071e20eb85SSrivatsa Vaddagiri	  may incur significant overhead.
8081e20eb85SSrivatsa Vaddagiri
8096276a074SBorislav Petkovconfig PARAVIRT_TIME_ACCOUNTING
8106276a074SBorislav Petkov	bool "Paravirtual steal time accounting"
8116276a074SBorislav Petkov	depends on PARAVIRT
8126276a074SBorislav Petkov	default n
8136276a074SBorislav Petkov	---help---
8146276a074SBorislav Petkov	  Select this option to enable fine granularity task steal time
8156276a074SBorislav Petkov	  accounting. Time spent executing other tasks in parallel with
8166276a074SBorislav Petkov	  the current vCPU is discounted from the vCPU power. To account for
8176276a074SBorislav Petkov	  that, there can be a small performance impact.
8186276a074SBorislav Petkov
8196276a074SBorislav Petkov	  If in doubt, say N here.
8206276a074SBorislav Petkov
8217af192c9SGerd Hoffmannconfig PARAVIRT_CLOCK
8227af192c9SGerd Hoffmann	bool
8237af192c9SGerd Hoffmann
8244a362601SJan Kiszkaconfig JAILHOUSE_GUEST
8254a362601SJan Kiszka	bool "Jailhouse non-root cell support"
826abde587bSArnd Bergmann	depends on X86_64 && PCI
82787e65d05SJan Kiszka	select X86_PM_TIMER
8284a362601SJan Kiszka	---help---
8294a362601SJan Kiszka	  This option allows to run Linux as guest in a Jailhouse non-root
8304a362601SJan Kiszka	  cell. You can leave this option disabled if you only want to start
8314a362601SJan Kiszka	  Jailhouse and run Linux afterwards in the root cell.
8324a362601SJan Kiszka
8336276a074SBorislav Petkovendif #HYPERVISOR_GUEST
83497349135SJeremy Fitzhardinge
83508677214SYinghai Luconfig NO_BOOTMEM
836774ea0bcSYinghai Lu	def_bool y
83708677214SYinghai Lu
838506f1d07SSam Ravnborgsource "arch/x86/Kconfig.cpu"
839506f1d07SSam Ravnborg
840506f1d07SSam Ravnborgconfig HPET_TIMER
8413c2362e6SHarvey Harrison	def_bool X86_64
842506f1d07SSam Ravnborg	prompt "HPET Timer Support" if X86_32
8438f9ca475SIngo Molnar	---help---
844506f1d07SSam Ravnborg	  Use the IA-PC HPET (High Precision Event Timer) to manage
845506f1d07SSam Ravnborg	  time in preference to the PIT and RTC, if a HPET is
846506f1d07SSam Ravnborg	  present.
847506f1d07SSam Ravnborg	  HPET is the next generation timer replacing legacy 8254s.
848506f1d07SSam Ravnborg	  The HPET provides a stable time base on SMP
849506f1d07SSam Ravnborg	  systems, unlike the TSC, but it is more expensive to access,
8504e7f9df2SMichael S. Tsirkin	  as it is off-chip.  The interface used is documented
8514e7f9df2SMichael S. Tsirkin	  in the HPET spec, revision 1.
852506f1d07SSam Ravnborg
853506f1d07SSam Ravnborg	  You can safely choose Y here.  However, HPET will only be
854506f1d07SSam Ravnborg	  activated if the platform and the BIOS support this feature.
855506f1d07SSam Ravnborg	  Otherwise the 8254 will be used for timing services.
856506f1d07SSam Ravnborg
857506f1d07SSam Ravnborg	  Choose N to continue using the legacy 8254 timer.
858506f1d07SSam Ravnborg
859506f1d07SSam Ravnborgconfig HPET_EMULATE_RTC
8603c2362e6SHarvey Harrison	def_bool y
8619d8af78bSBernhard Walle	depends on HPET_TIMER && (RTC=y || RTC=m || RTC_DRV_CMOS=m || RTC_DRV_CMOS=y)
862506f1d07SSam Ravnborg
863bb24c471SJacob Panconfig APB_TIMER
864933b9463SAlan Cox       def_bool y if X86_INTEL_MID
865933b9463SAlan Cox       prompt "Intel MID APB Timer Support" if X86_INTEL_MID
86606c3df49SJamie Iles       select DW_APB_TIMER
867a0c3832aSAlan Cox       depends on X86_INTEL_MID && SFI
868bb24c471SJacob Pan       help
869bb24c471SJacob Pan         APB timer is the replacement for 8254, HPET on X86 MID platforms.
870bb24c471SJacob Pan         The APBT provides a stable time base on SMP
871bb24c471SJacob Pan         systems, unlike the TSC, but it is more expensive to access,
872bb24c471SJacob Pan         as it is off-chip. APB timers are always running regardless of CPU
873bb24c471SJacob Pan         C states, they are used as per CPU clockevent device when possible.
874bb24c471SJacob Pan
8756a108a14SDavid Rientjes# Mark as expert because too many people got it wrong.
876506f1d07SSam Ravnborg# The code disables itself when not needed.
8777ae9392cSThomas Petazzoniconfig DMI
8787ae9392cSThomas Petazzoni	default y
879cf074402SArd Biesheuvel	select DMI_SCAN_MACHINE_NON_EFI_FALLBACK
8806a108a14SDavid Rientjes	bool "Enable DMI scanning" if EXPERT
8818f9ca475SIngo Molnar	---help---
8827ae9392cSThomas Petazzoni	  Enabled scanning of DMI to identify machine quirks. Say Y
8837ae9392cSThomas Petazzoni	  here unless you have verified that your setup is not
8847ae9392cSThomas Petazzoni	  affected by entries in the DMI blacklist. Required by PNP
8857ae9392cSThomas Petazzoni	  BIOS code.
8867ae9392cSThomas Petazzoni
887506f1d07SSam Ravnborgconfig GART_IOMMU
88838901f1cSAndi Kleen	bool "Old AMD GART IOMMU support"
889a4ce5a48SChristoph Hellwig	select IOMMU_HELPER
890506f1d07SSam Ravnborg	select SWIOTLB
89123ac4ae8SAndreas Herrmann	depends on X86_64 && PCI && AMD_NB
8928f9ca475SIngo Molnar	---help---
893ced3c42cSIngo Molnar	  Provides a driver for older AMD Athlon64/Opteron/Turion/Sempron
894ced3c42cSIngo Molnar	  GART based hardware IOMMUs.
895ced3c42cSIngo Molnar
896ced3c42cSIngo Molnar	  The GART supports full DMA access for devices with 32-bit access
897ced3c42cSIngo Molnar	  limitations, on systems with more than 3 GB. This is usually needed
898ced3c42cSIngo Molnar	  for USB, sound, many IDE/SATA chipsets and some other devices.
899ced3c42cSIngo Molnar
900ced3c42cSIngo Molnar	  Newer systems typically have a modern AMD IOMMU, supported via
901ced3c42cSIngo Molnar	  the CONFIG_AMD_IOMMU=y config option.
902ced3c42cSIngo Molnar
903ced3c42cSIngo Molnar	  In normal configurations this driver is only active when needed:
904ced3c42cSIngo Molnar	  there's more than 3 GB of memory and the system contains a
905ced3c42cSIngo Molnar	  32-bit limited device.
906ced3c42cSIngo Molnar
907ced3c42cSIngo Molnar	  If unsure, say Y.
908506f1d07SSam Ravnborg
909506f1d07SSam Ravnborgconfig CALGARY_IOMMU
910506f1d07SSam Ravnborg	bool "IBM Calgary IOMMU support"
911a4ce5a48SChristoph Hellwig	select IOMMU_HELPER
912506f1d07SSam Ravnborg	select SWIOTLB
9136ea30386SKees Cook	depends on X86_64 && PCI
9148f9ca475SIngo Molnar	---help---
915506f1d07SSam Ravnborg	  Support for hardware IOMMUs in IBM's xSeries x366 and x460
916506f1d07SSam Ravnborg	  systems. Needed to run systems with more than 3GB of memory
917506f1d07SSam Ravnborg	  properly with 32-bit PCI devices that do not support DAC
918506f1d07SSam Ravnborg	  (Double Address Cycle). Calgary also supports bus level
919506f1d07SSam Ravnborg	  isolation, where all DMAs pass through the IOMMU.  This
920506f1d07SSam Ravnborg	  prevents them from going anywhere except their intended
921506f1d07SSam Ravnborg	  destination. This catches hard-to-find kernel bugs and
922506f1d07SSam Ravnborg	  mis-behaving drivers and devices that do not use the DMA-API
923506f1d07SSam Ravnborg	  properly to set up their DMA buffers.  The IOMMU can be
924506f1d07SSam Ravnborg	  turned off at boot time with the iommu=off parameter.
925506f1d07SSam Ravnborg	  Normally the kernel will make the right choice by itself.
926506f1d07SSam Ravnborg	  If unsure, say Y.
927506f1d07SSam Ravnborg
928506f1d07SSam Ravnborgconfig CALGARY_IOMMU_ENABLED_BY_DEFAULT
9293c2362e6SHarvey Harrison	def_bool y
9303c2362e6SHarvey Harrison	prompt "Should Calgary be enabled by default?"
931506f1d07SSam Ravnborg	depends on CALGARY_IOMMU
9328f9ca475SIngo Molnar	---help---
933506f1d07SSam Ravnborg	  Should Calgary be enabled by default? if you choose 'y', Calgary
934506f1d07SSam Ravnborg	  will be used (if it exists). If you choose 'n', Calgary will not be
935506f1d07SSam Ravnborg	  used even if it exists. If you choose 'n' and would like to use
936506f1d07SSam Ravnborg	  Calgary anyway, pass 'iommu=calgary' on the kernel command line.
937506f1d07SSam Ravnborg	  If unsure, say Y.
938506f1d07SSam Ravnborg
9391184dc2fSMike Travisconfig MAXSMP
940ddb0c5a6SSamuel Thibault	bool "Enable Maximum number of SMP Processors and NUMA Nodes"
9416ea30386SKees Cook	depends on X86_64 && SMP && DEBUG_KERNEL
94236f5101aSMike Travis	select CPUMASK_OFFSTACK
9438f9ca475SIngo Molnar	---help---
944ddb0c5a6SSamuel Thibault	  Enable maximum number of CPUS and NUMA Nodes for this architecture.
9451184dc2fSMike Travis	  If unsure, say N.
946506f1d07SSam Ravnborg
947aec6487eSIngo Molnar#
948aec6487eSIngo Molnar# The maximum number of CPUs supported:
949aec6487eSIngo Molnar#
950aec6487eSIngo Molnar# The main config value is NR_CPUS, which defaults to NR_CPUS_DEFAULT,
951aec6487eSIngo Molnar# and which can be configured interactively in the
952aec6487eSIngo Molnar# [NR_CPUS_RANGE_BEGIN ... NR_CPUS_RANGE_END] range.
953aec6487eSIngo Molnar#
954aec6487eSIngo Molnar# The ranges are different on 32-bit and 64-bit kernels, depending on
955aec6487eSIngo Molnar# hardware capabilities and scalability features of the kernel.
956aec6487eSIngo Molnar#
957aec6487eSIngo Molnar# ( If MAXSMP is enabled we just use the highest possible value and disable
958aec6487eSIngo Molnar#   interactive configuration. )
959aec6487eSIngo Molnar#
960a0d0bb4dSRandy Dunlap
961aec6487eSIngo Molnarconfig NR_CPUS_RANGE_BEGIN
962a0d0bb4dSRandy Dunlap	int
963aec6487eSIngo Molnar	default NR_CPUS_RANGE_END if MAXSMP
964a0d0bb4dSRandy Dunlap	default    1 if !SMP
965a0d0bb4dSRandy Dunlap	default    2
966a0d0bb4dSRandy Dunlap
967aec6487eSIngo Molnarconfig NR_CPUS_RANGE_END
968a0d0bb4dSRandy Dunlap	int
969a0d0bb4dSRandy Dunlap	depends on X86_32
970aec6487eSIngo Molnar	default   64 if  SMP &&  X86_BIGSMP
971aec6487eSIngo Molnar	default    8 if  SMP && !X86_BIGSMP
972a0d0bb4dSRandy Dunlap	default    1 if !SMP
973a0d0bb4dSRandy Dunlap
974aec6487eSIngo Molnarconfig NR_CPUS_RANGE_END
975a0d0bb4dSRandy Dunlap	int
976a0d0bb4dSRandy Dunlap	depends on X86_64
977aec6487eSIngo Molnar	default 8192 if  SMP && ( MAXSMP ||  CPUMASK_OFFSTACK)
978aec6487eSIngo Molnar	default  512 if  SMP && (!MAXSMP && !CPUMASK_OFFSTACK)
979a0d0bb4dSRandy Dunlap	default    1 if !SMP
980aec6487eSIngo Molnar
981aec6487eSIngo Molnarconfig NR_CPUS_DEFAULT
982aec6487eSIngo Molnar	int
983aec6487eSIngo Molnar	depends on X86_32
984aec6487eSIngo Molnar	default   32 if  X86_BIGSMP
985aec6487eSIngo Molnar	default    8 if  SMP
986aec6487eSIngo Molnar	default    1 if !SMP
987aec6487eSIngo Molnar
988aec6487eSIngo Molnarconfig NR_CPUS_DEFAULT
989aec6487eSIngo Molnar	int
990aec6487eSIngo Molnar	depends on X86_64
991a0d0bb4dSRandy Dunlap	default 8192 if  MAXSMP
992a0d0bb4dSRandy Dunlap	default   64 if  SMP
993aec6487eSIngo Molnar	default    1 if !SMP
994a0d0bb4dSRandy Dunlap
995506f1d07SSam Ravnborgconfig NR_CPUS
99636f5101aSMike Travis	int "Maximum number of CPUs" if SMP && !MAXSMP
997aec6487eSIngo Molnar	range NR_CPUS_RANGE_BEGIN NR_CPUS_RANGE_END
998aec6487eSIngo Molnar	default NR_CPUS_DEFAULT
9998f9ca475SIngo Molnar	---help---
1000506f1d07SSam Ravnborg	  This allows you to specify the maximum number of CPUs which this
1001bb61ccc7SJosh Boyer	  kernel will support.  If CPUMASK_OFFSTACK is enabled, the maximum
1002cad14bb9SKirill A. Shutemov	  supported value is 8192, otherwise the maximum value is 512.  The
1003506f1d07SSam Ravnborg	  minimum value which makes sense is 2.
1004506f1d07SSam Ravnborg
1005aec6487eSIngo Molnar	  This is purely to save memory: each supported CPU adds about 8KB
1006aec6487eSIngo Molnar	  to the kernel image.
1007506f1d07SSam Ravnborg
1008506f1d07SSam Ravnborgconfig SCHED_SMT
1009506f1d07SSam Ravnborg	bool "SMT (Hyperthreading) scheduler support"
1010c8e56d20SBorislav Petkov	depends on SMP
10118f9ca475SIngo Molnar	---help---
1012506f1d07SSam Ravnborg	  SMT scheduler support improves the CPU scheduler's decision making
1013506f1d07SSam Ravnborg	  when dealing with Intel Pentium 4 chips with HyperThreading at a
1014506f1d07SSam Ravnborg	  cost of slightly increased overhead in some places. If unsure say
1015506f1d07SSam Ravnborg	  N here.
1016506f1d07SSam Ravnborg
1017506f1d07SSam Ravnborgconfig SCHED_MC
10183c2362e6SHarvey Harrison	def_bool y
10193c2362e6SHarvey Harrison	prompt "Multi-core scheduler support"
1020c8e56d20SBorislav Petkov	depends on SMP
10218f9ca475SIngo Molnar	---help---
1022506f1d07SSam Ravnborg	  Multi-core scheduler support improves the CPU scheduler's decision
1023506f1d07SSam Ravnborg	  making when dealing with multi-core CPU chips at a cost of slightly
1024506f1d07SSam Ravnborg	  increased overhead in some places. If unsure say N here.
1025506f1d07SSam Ravnborg
1026de966cf4STim Chenconfig SCHED_MC_PRIO
1027de966cf4STim Chen	bool "CPU core priorities scheduler support"
10280a21fc12SIngo Molnar	depends on SCHED_MC && CPU_SUP_INTEL
10290a21fc12SIngo Molnar	select X86_INTEL_PSTATE
10300a21fc12SIngo Molnar	select CPU_FREQ
1031de966cf4STim Chen	default y
10325e76b2abSTim Chen	---help---
1033de966cf4STim Chen	  Intel Turbo Boost Max Technology 3.0 enabled CPUs have a
1034de966cf4STim Chen	  core ordering determined at manufacturing time, which allows
1035de966cf4STim Chen	  certain cores to reach higher turbo frequencies (when running
1036de966cf4STim Chen	  single threaded workloads) than others.
1037de966cf4STim Chen
1038de966cf4STim Chen	  Enabling this kernel feature teaches the scheduler about
1039de966cf4STim Chen	  the TBM3 (aka ITMT) priority order of the CPU cores and adjusts the
1040de966cf4STim Chen	  scheduler's CPU selection logic accordingly, so that higher
1041de966cf4STim Chen	  overall system performance can be achieved.
1042de966cf4STim Chen
1043de966cf4STim Chen	  This feature will have no effect on CPUs without this feature.
1044de966cf4STim Chen
1045de966cf4STim Chen	  If unsure say Y here.
10465e76b2abSTim Chen
104730b8b006SThomas Gleixnerconfig UP_LATE_INIT
104830b8b006SThomas Gleixner       def_bool y
1049ba360f88SThomas Gleixner       depends on !SMP && X86_LOCAL_APIC
105030b8b006SThomas Gleixner
1051506f1d07SSam Ravnborgconfig X86_UP_APIC
105250849eefSJan Beulich	bool "Local APIC support on uniprocessors" if !PCI_MSI
105350849eefSJan Beulich	default PCI_MSI
105438a1dfdaSBryan O'Donoghue	depends on X86_32 && !SMP && !X86_32_NON_STANDARD
10558f9ca475SIngo Molnar	---help---
1056506f1d07SSam Ravnborg	  A local APIC (Advanced Programmable Interrupt Controller) is an
1057506f1d07SSam Ravnborg	  integrated interrupt controller in the CPU. If you have a single-CPU
1058506f1d07SSam Ravnborg	  system which has a processor with a local APIC, you can say Y here to
1059506f1d07SSam Ravnborg	  enable and use it. If you say Y here even though your machine doesn't
1060506f1d07SSam Ravnborg	  have a local APIC, then the kernel will still run with no slowdown at
1061506f1d07SSam Ravnborg	  all. The local APIC supports CPU-generated self-interrupts (timer,
1062506f1d07SSam Ravnborg	  performance counters), and the NMI watchdog which detects hard
1063506f1d07SSam Ravnborg	  lockups.
1064506f1d07SSam Ravnborg
1065506f1d07SSam Ravnborgconfig X86_UP_IOAPIC
1066506f1d07SSam Ravnborg	bool "IO-APIC support on uniprocessors"
1067506f1d07SSam Ravnborg	depends on X86_UP_APIC
10688f9ca475SIngo Molnar	---help---
1069506f1d07SSam Ravnborg	  An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an
1070506f1d07SSam Ravnborg	  SMP-capable replacement for PC-style interrupt controllers. Most
1071506f1d07SSam Ravnborg	  SMP systems and many recent uniprocessor systems have one.
1072506f1d07SSam Ravnborg
1073506f1d07SSam Ravnborg	  If you have a single-CPU system with an IO-APIC, you can say Y here
1074506f1d07SSam Ravnborg	  to use it. If you say Y here even though your machine doesn't have
1075506f1d07SSam Ravnborg	  an IO-APIC, then the kernel will still run with no slowdown at all.
1076506f1d07SSam Ravnborg
1077506f1d07SSam Ravnborgconfig X86_LOCAL_APIC
10783c2362e6SHarvey Harrison	def_bool y
10790dbc6078SThomas Petazzoni	depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC || PCI_MSI
1080b5dc8e6cSJiang Liu	select IRQ_DOMAIN_HIERARCHY
108152f518a3SJiang Liu	select PCI_MSI_IRQ_DOMAIN if PCI_MSI
1082506f1d07SSam Ravnborg
1083506f1d07SSam Ravnborgconfig X86_IO_APIC
1084b1da1e71SJan Beulich	def_bool y
1085b1da1e71SJan Beulich	depends on X86_LOCAL_APIC || X86_UP_IOAPIC
1086506f1d07SSam Ravnborg
108741b9eb26SStefan Assmannconfig X86_REROUTE_FOR_BROKEN_BOOT_IRQS
108841b9eb26SStefan Assmann	bool "Reroute for broken boot IRQs"
108941b9eb26SStefan Assmann	depends on X86_IO_APIC
10908f9ca475SIngo Molnar	---help---
109141b9eb26SStefan Assmann	  This option enables a workaround that fixes a source of
109241b9eb26SStefan Assmann	  spurious interrupts. This is recommended when threaded
109341b9eb26SStefan Assmann	  interrupt handling is used on systems where the generation of
109441b9eb26SStefan Assmann	  superfluous "boot interrupts" cannot be disabled.
109541b9eb26SStefan Assmann
109641b9eb26SStefan Assmann	  Some chipsets generate a legacy INTx "boot IRQ" when the IRQ
109741b9eb26SStefan Assmann	  entry in the chipset's IO-APIC is masked (as, e.g. the RT
109841b9eb26SStefan Assmann	  kernel does during interrupt handling). On chipsets where this
109941b9eb26SStefan Assmann	  boot IRQ generation cannot be disabled, this workaround keeps
110041b9eb26SStefan Assmann	  the original IRQ line masked so that only the equivalent "boot
110141b9eb26SStefan Assmann	  IRQ" is delivered to the CPUs. The workaround also tells the
110241b9eb26SStefan Assmann	  kernel to set up the IRQ handler on the boot IRQ line. In this
110341b9eb26SStefan Assmann	  way only one interrupt is delivered to the kernel. Otherwise
110441b9eb26SStefan Assmann	  the spurious second interrupt may cause the kernel to bring
110541b9eb26SStefan Assmann	  down (vital) interrupt lines.
110641b9eb26SStefan Assmann
110741b9eb26SStefan Assmann	  Only affects "broken" chipsets. Interrupt sharing may be
110841b9eb26SStefan Assmann	  increased on these systems.
110941b9eb26SStefan Assmann
1110506f1d07SSam Ravnborgconfig X86_MCE
1111bab9bc65SAndi Kleen	bool "Machine Check / overheating reporting"
1112648ed940SChen, Gong	select GENERIC_ALLOCATOR
1113e57dbaf7SBorislav Petkov	default y
1114506f1d07SSam Ravnborg	---help---
1115bab9bc65SAndi Kleen	  Machine Check support allows the processor to notify the
1116bab9bc65SAndi Kleen	  kernel if it detects a problem (e.g. overheating, data corruption).
1117506f1d07SSam Ravnborg	  The action the kernel takes depends on the severity of the problem,
1118bab9bc65SAndi Kleen	  ranging from warning messages to halting the machine.
11194efc0670SAndi Kleen
11205de97c9fSTony Luckconfig X86_MCELOG_LEGACY
11215de97c9fSTony Luck	bool "Support for deprecated /dev/mcelog character device"
11225de97c9fSTony Luck	depends on X86_MCE
11235de97c9fSTony Luck	---help---
11245de97c9fSTony Luck	  Enable support for /dev/mcelog which is needed by the old mcelog
11255de97c9fSTony Luck	  userspace logging daemon. Consider switching to the new generation
11265de97c9fSTony Luck	  rasdaemon solution.
11275de97c9fSTony Luck
1128506f1d07SSam Ravnborgconfig X86_MCE_INTEL
11293c2362e6SHarvey Harrison	def_bool y
11303c2362e6SHarvey Harrison	prompt "Intel MCE features"
1131c1ebf835SAndi Kleen	depends on X86_MCE && X86_LOCAL_APIC
11328f9ca475SIngo Molnar	---help---
1133506f1d07SSam Ravnborg	   Additional support for intel specific MCE features such as
1134506f1d07SSam Ravnborg	   the thermal monitor.
1135506f1d07SSam Ravnborg
1136506f1d07SSam Ravnborgconfig X86_MCE_AMD
11373c2362e6SHarvey Harrison	def_bool y
11383c2362e6SHarvey Harrison	prompt "AMD MCE features"
1139f5382de9SYazen Ghannam	depends on X86_MCE && X86_LOCAL_APIC && AMD_NB
11408f9ca475SIngo Molnar	---help---
1141506f1d07SSam Ravnborg	   Additional support for AMD specific MCE features such as
1142506f1d07SSam Ravnborg	   the DRAM Error Threshold.
1143506f1d07SSam Ravnborg
11444efc0670SAndi Kleenconfig X86_ANCIENT_MCE
11456fc108a0SJan Beulich	bool "Support for old Pentium 5 / WinChip machine checks"
1146c31d9633SAndi Kleen	depends on X86_32 && X86_MCE
11474efc0670SAndi Kleen	---help---
11484efc0670SAndi Kleen	  Include support for machine check handling on old Pentium 5 or WinChip
11495065a706SMasanari Iida	  systems. These typically need to be enabled explicitly on the command
11504efc0670SAndi Kleen	  line.
11514efc0670SAndi Kleen
1152b2762686SAndi Kleenconfig X86_MCE_THRESHOLD
1153b2762686SAndi Kleen	depends on X86_MCE_AMD || X86_MCE_INTEL
11546fc108a0SJan Beulich	def_bool y
1155b2762686SAndi Kleen
1156ea149b36SAndi Kleenconfig X86_MCE_INJECT
1157bc8e80d5SBorislav Petkov	depends on X86_MCE && X86_LOCAL_APIC && DEBUG_FS
1158ea149b36SAndi Kleen	tristate "Machine check injector support"
1159ea149b36SAndi Kleen	---help---
1160ea149b36SAndi Kleen	  Provide support for injecting machine checks for testing purposes.
1161ea149b36SAndi Kleen	  If you don't know what a machine check is and you don't do kernel
1162ea149b36SAndi Kleen	  QA it is safe to say n.
1163ea149b36SAndi Kleen
11644efc0670SAndi Kleenconfig X86_THERMAL_VECTOR
11654efc0670SAndi Kleen	def_bool y
11665bb38adcSAndi Kleen	depends on X86_MCE_INTEL
11674efc0670SAndi Kleen
116807dc900eSPeter Zijlstrasource "arch/x86/events/Kconfig"
1169e633c65aSKan Liang
11705aef51c3SAndy Lutomirskiconfig X86_LEGACY_VM86
11711e642812SIngo Molnar	bool "Legacy VM86 support"
11725aef51c3SAndy Lutomirski	default n
1173506f1d07SSam Ravnborg	depends on X86_32
11748f9ca475SIngo Molnar	---help---
11755aef51c3SAndy Lutomirski	  This option allows user programs to put the CPU into V8086
11765aef51c3SAndy Lutomirski	  mode, which is an 80286-era approximation of 16-bit real mode.
11775aef51c3SAndy Lutomirski
11785aef51c3SAndy Lutomirski	  Some very old versions of X and/or vbetool require this option
11795aef51c3SAndy Lutomirski	  for user mode setting.  Similarly, DOSEMU will use it if
11805aef51c3SAndy Lutomirski	  available to accelerate real mode DOS programs.  However, any
11815aef51c3SAndy Lutomirski	  recent version of DOSEMU, X, or vbetool should be fully
11825aef51c3SAndy Lutomirski	  functional even without kernel VM86 support, as they will all
11831e642812SIngo Molnar	  fall back to software emulation. Nevertheless, if you are using
11841e642812SIngo Molnar	  a 16-bit DOS program where 16-bit performance matters, vm86
11851e642812SIngo Molnar	  mode might be faster than emulation and you might want to
11861e642812SIngo Molnar	  enable this option.
11875aef51c3SAndy Lutomirski
11881e642812SIngo Molnar	  Note that any app that works on a 64-bit kernel is unlikely to
11891e642812SIngo Molnar	  need this option, as 64-bit kernels don't, and can't, support
11901e642812SIngo Molnar	  V8086 mode. This option is also unrelated to 16-bit protected
11911e642812SIngo Molnar	  mode and is not needed to run most 16-bit programs under Wine.
11925aef51c3SAndy Lutomirski
11931e642812SIngo Molnar	  Enabling this option increases the complexity of the kernel
11941e642812SIngo Molnar	  and slows down exception handling a tiny bit.
11955aef51c3SAndy Lutomirski
11961e642812SIngo Molnar	  If unsure, say N here.
11975aef51c3SAndy Lutomirski
11985aef51c3SAndy Lutomirskiconfig VM86
11995aef51c3SAndy Lutomirski       bool
12005aef51c3SAndy Lutomirski       default X86_LEGACY_VM86
120134273f41SH. Peter Anvin
120234273f41SH. Peter Anvinconfig X86_16BIT
120334273f41SH. Peter Anvin	bool "Enable support for 16-bit segments" if EXPERT
120434273f41SH. Peter Anvin	default y
1205a5b9e5a2SAndy Lutomirski	depends on MODIFY_LDT_SYSCALL
120634273f41SH. Peter Anvin	---help---
120734273f41SH. Peter Anvin	  This option is required by programs like Wine to run 16-bit
120834273f41SH. Peter Anvin	  protected mode legacy code on x86 processors.  Disabling
120934273f41SH. Peter Anvin	  this option saves about 300 bytes on i386, or around 6K text
121034273f41SH. Peter Anvin	  plus 16K runtime memory on x86-64,
121134273f41SH. Peter Anvin
121234273f41SH. Peter Anvinconfig X86_ESPFIX32
121334273f41SH. Peter Anvin	def_bool y
121434273f41SH. Peter Anvin	depends on X86_16BIT && X86_32
1215506f1d07SSam Ravnborg
1216197725deSH. Peter Anvinconfig X86_ESPFIX64
1217197725deSH. Peter Anvin	def_bool y
121834273f41SH. Peter Anvin	depends on X86_16BIT && X86_64
1219506f1d07SSam Ravnborg
12201ad83c85SAndy Lutomirskiconfig X86_VSYSCALL_EMULATION
12211ad83c85SAndy Lutomirski       bool "Enable vsyscall emulation" if EXPERT
12221ad83c85SAndy Lutomirski       default y
12231ad83c85SAndy Lutomirski       depends on X86_64
12241ad83c85SAndy Lutomirski       ---help---
12251ad83c85SAndy Lutomirski	 This enables emulation of the legacy vsyscall page.  Disabling
12261ad83c85SAndy Lutomirski	 it is roughly equivalent to booting with vsyscall=none, except
12271ad83c85SAndy Lutomirski	 that it will also disable the helpful warning if a program
12281ad83c85SAndy Lutomirski	 tries to use a vsyscall.  With this option set to N, offending
12291ad83c85SAndy Lutomirski	 programs will just segfault, citing addresses of the form
12301ad83c85SAndy Lutomirski	 0xffffffffff600?00.
12311ad83c85SAndy Lutomirski
12321ad83c85SAndy Lutomirski	 This option is required by many programs built before 2013, and
12331ad83c85SAndy Lutomirski	 care should be used even with newer programs if set to N.
12341ad83c85SAndy Lutomirski
12351ad83c85SAndy Lutomirski	 Disabling this option saves about 7K of kernel size and
12361ad83c85SAndy Lutomirski	 possibly 4K of additional runtime pagetable memory.
12371ad83c85SAndy Lutomirski
1238506f1d07SSam Ravnborgconfig TOSHIBA
1239506f1d07SSam Ravnborg	tristate "Toshiba Laptop support"
1240506f1d07SSam Ravnborg	depends on X86_32
1241506f1d07SSam Ravnborg	---help---
1242506f1d07SSam Ravnborg	  This adds a driver to safely access the System Management Mode of
1243506f1d07SSam Ravnborg	  the CPU on Toshiba portables with a genuine Toshiba BIOS. It does
1244506f1d07SSam Ravnborg	  not work on models with a Phoenix BIOS. The System Management Mode
1245506f1d07SSam Ravnborg	  is used to set the BIOS and power saving options on Toshiba portables.
1246506f1d07SSam Ravnborg
1247506f1d07SSam Ravnborg	  For information on utilities to make use of this driver see the
1248506f1d07SSam Ravnborg	  Toshiba Linux utilities web site at:
1249506f1d07SSam Ravnborg	  <http://www.buzzard.org.uk/toshiba/>.
1250506f1d07SSam Ravnborg
1251506f1d07SSam Ravnborg	  Say Y if you intend to run this kernel on a Toshiba portable.
1252506f1d07SSam Ravnborg	  Say N otherwise.
1253506f1d07SSam Ravnborg
1254506f1d07SSam Ravnborgconfig I8K
1255039ae585SPali Rohár	tristate "Dell i8k legacy laptop support"
1256949a9d70SJean Delvare	select HWMON
1257039ae585SPali Rohár	select SENSORS_DELL_SMM
1258506f1d07SSam Ravnborg	---help---
1259039ae585SPali Rohár	  This option enables legacy /proc/i8k userspace interface in hwmon
1260039ae585SPali Rohár	  dell-smm-hwmon driver. Character file /proc/i8k reports bios version,
1261039ae585SPali Rohár	  temperature and allows controlling fan speeds of Dell laptops via
1262039ae585SPali Rohár	  System Management Mode. For old Dell laptops (like Dell Inspiron 8000)
1263039ae585SPali Rohár	  it reports also power and hotkey status. For fan speed control is
1264039ae585SPali Rohár	  needed userspace package i8kutils.
1265506f1d07SSam Ravnborg
1266039ae585SPali Rohár	  Say Y if you intend to run this kernel on old Dell laptops or want to
1267039ae585SPali Rohár	  use userspace package i8kutils.
1268506f1d07SSam Ravnborg	  Say N otherwise.
1269506f1d07SSam Ravnborg
1270506f1d07SSam Ravnborgconfig X86_REBOOTFIXUPS
12719ba16087SJan Beulich	bool "Enable X86 board specific fixups for reboot"
12729ba16087SJan Beulich	depends on X86_32
1273506f1d07SSam Ravnborg	---help---
1274506f1d07SSam Ravnborg	  This enables chipset and/or board specific fixups to be done
1275506f1d07SSam Ravnborg	  in order to get reboot to work correctly. This is only needed on
1276506f1d07SSam Ravnborg	  some combinations of hardware and BIOS. The symptom, for which
1277506f1d07SSam Ravnborg	  this config is intended, is when reboot ends with a stalled/hung
1278506f1d07SSam Ravnborg	  system.
1279506f1d07SSam Ravnborg
1280506f1d07SSam Ravnborg	  Currently, the only fixup is for the Geode machines using
12815e3a77e9SFlorian Fainelli	  CS5530A and CS5536 chipsets and the RDC R-321x SoC.
1282506f1d07SSam Ravnborg
1283506f1d07SSam Ravnborg	  Say Y if you want to enable the fixup. Currently, it's safe to
1284506f1d07SSam Ravnborg	  enable this option even if you don't need it.
1285506f1d07SSam Ravnborg	  Say N otherwise.
1286506f1d07SSam Ravnborg
1287506f1d07SSam Ravnborgconfig MICROCODE
12889a2bc335SBorislav Petkov	bool "CPU microcode loading support"
12899a2bc335SBorislav Petkov	default y
129080030e3dSBorislav Petkov	depends on CPU_SUP_AMD || CPU_SUP_INTEL
1291506f1d07SSam Ravnborg	select FW_LOADER
1292506f1d07SSam Ravnborg	---help---
1293506f1d07SSam Ravnborg	  If you say Y here, you will be able to update the microcode on
12945f9c01aaSBorislav Petkov	  Intel and AMD processors. The Intel support is for the IA32 family,
12955f9c01aaSBorislav Petkov	  e.g. Pentium Pro, Pentium II, Pentium III, Pentium 4, Xeon etc. The
12965f9c01aaSBorislav Petkov	  AMD support is for families 0x10 and later. You will obviously need
12975f9c01aaSBorislav Petkov	  the actual microcode binary data itself which is not shipped with
12985f9c01aaSBorislav Petkov	  the Linux kernel.
1299506f1d07SSam Ravnborg
13005f9c01aaSBorislav Petkov	  The preferred method to load microcode from a detached initrd is described
13011897a969SJaak Ristioja	  in Documentation/x86/microcode.txt. For that you need to enable
13025f9c01aaSBorislav Petkov	  CONFIG_BLK_DEV_INITRD in order for the loader to be able to scan the
13035f9c01aaSBorislav Petkov	  initrd for microcode blobs.
1304506f1d07SSam Ravnborg
1305c508c46eSBenjamin Gilbert	  In addition, you can build the microcode into the kernel. For that you
1306c508c46eSBenjamin Gilbert	  need to add the vendor-supplied microcode to the CONFIG_EXTRA_FIRMWARE
1307c508c46eSBenjamin Gilbert	  config option.
1308506f1d07SSam Ravnborg
13098d86f390SPeter Orubaconfig MICROCODE_INTEL
1310e43f6e67SBorislav Petkov	bool "Intel microcode loading support"
13118d86f390SPeter Oruba	depends on MICROCODE
13128d86f390SPeter Oruba	default MICROCODE
13138d86f390SPeter Oruba	select FW_LOADER
13148f9ca475SIngo Molnar	---help---
13158d86f390SPeter Oruba	  This options enables microcode patch loading support for Intel
13168d86f390SPeter Oruba	  processors.
13178d86f390SPeter Oruba
1318b8989db9SAlan	  For the current Intel microcode data package go to
1319b8989db9SAlan	  <https://downloadcenter.intel.com> and search for
1320b8989db9SAlan	  'Linux Processor Microcode Data File'.
13218d86f390SPeter Oruba
132280cc9f10SPeter Orubaconfig MICROCODE_AMD
1323e43f6e67SBorislav Petkov	bool "AMD microcode loading support"
132480cc9f10SPeter Oruba	depends on MICROCODE
132580cc9f10SPeter Oruba	select FW_LOADER
13268f9ca475SIngo Molnar	---help---
132780cc9f10SPeter Oruba	  If you select this option, microcode patch loading support for AMD
132880cc9f10SPeter Oruba	  processors will be enabled.
132980cc9f10SPeter Oruba
1330506f1d07SSam Ravnborgconfig MICROCODE_OLD_INTERFACE
13313c2362e6SHarvey Harrison	def_bool y
1332506f1d07SSam Ravnborg	depends on MICROCODE
1333506f1d07SSam Ravnborg
1334506f1d07SSam Ravnborgconfig X86_MSR
1335506f1d07SSam Ravnborg	tristate "/dev/cpu/*/msr - Model-specific register support"
13368f9ca475SIngo Molnar	---help---
1337506f1d07SSam Ravnborg	  This device gives privileged processes access to the x86
1338506f1d07SSam Ravnborg	  Model-Specific Registers (MSRs).  It is a character device with
1339506f1d07SSam Ravnborg	  major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr.
1340506f1d07SSam Ravnborg	  MSR accesses are directed to a specific CPU on multi-processor
1341506f1d07SSam Ravnborg	  systems.
1342506f1d07SSam Ravnborg
1343506f1d07SSam Ravnborgconfig X86_CPUID
1344506f1d07SSam Ravnborg	tristate "/dev/cpu/*/cpuid - CPU information support"
13458f9ca475SIngo Molnar	---help---
1346506f1d07SSam Ravnborg	  This device gives processes access to the x86 CPUID instruction to
1347506f1d07SSam Ravnborg	  be executed on a specific processor.  It is a character device
1348506f1d07SSam Ravnborg	  with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to
1349506f1d07SSam Ravnborg	  /dev/cpu/31/cpuid.
1350506f1d07SSam Ravnborg
1351506f1d07SSam Ravnborgchoice
1352506f1d07SSam Ravnborg	prompt "High Memory Support"
13536fc108a0SJan Beulich	default HIGHMEM4G
1354506f1d07SSam Ravnborg	depends on X86_32
1355506f1d07SSam Ravnborg
1356506f1d07SSam Ravnborgconfig NOHIGHMEM
1357506f1d07SSam Ravnborg	bool "off"
1358506f1d07SSam Ravnborg	---help---
1359506f1d07SSam Ravnborg	  Linux can use up to 64 Gigabytes of physical memory on x86 systems.
1360506f1d07SSam Ravnborg	  However, the address space of 32-bit x86 processors is only 4
1361506f1d07SSam Ravnborg	  Gigabytes large. That means that, if you have a large amount of
1362506f1d07SSam Ravnborg	  physical memory, not all of it can be "permanently mapped" by the
1363506f1d07SSam Ravnborg	  kernel. The physical memory that's not permanently mapped is called
1364506f1d07SSam Ravnborg	  "high memory".
1365506f1d07SSam Ravnborg
1366506f1d07SSam Ravnborg	  If you are compiling a kernel which will never run on a machine with
1367506f1d07SSam Ravnborg	  more than 1 Gigabyte total physical RAM, answer "off" here (default
1368506f1d07SSam Ravnborg	  choice and suitable for most users). This will result in a "3GB/1GB"
1369506f1d07SSam Ravnborg	  split: 3GB are mapped so that each process sees a 3GB virtual memory
1370506f1d07SSam Ravnborg	  space and the remaining part of the 4GB virtual memory space is used
1371506f1d07SSam Ravnborg	  by the kernel to permanently map as much physical memory as
1372506f1d07SSam Ravnborg	  possible.
1373506f1d07SSam Ravnborg
1374506f1d07SSam Ravnborg	  If the machine has between 1 and 4 Gigabytes physical RAM, then
1375506f1d07SSam Ravnborg	  answer "4GB" here.
1376506f1d07SSam Ravnborg
1377506f1d07SSam Ravnborg	  If more than 4 Gigabytes is used then answer "64GB" here. This
1378506f1d07SSam Ravnborg	  selection turns Intel PAE (Physical Address Extension) mode on.
1379506f1d07SSam Ravnborg	  PAE implements 3-level paging on IA32 processors. PAE is fully
1380506f1d07SSam Ravnborg	  supported by Linux, PAE mode is implemented on all recent Intel
1381506f1d07SSam Ravnborg	  processors (Pentium Pro and better). NOTE: If you say "64GB" here,
1382506f1d07SSam Ravnborg	  then the kernel will not boot on CPUs that don't support PAE!
1383506f1d07SSam Ravnborg
1384506f1d07SSam Ravnborg	  The actual amount of total physical memory will either be
1385506f1d07SSam Ravnborg	  auto detected or can be forced by using a kernel command line option
1386506f1d07SSam Ravnborg	  such as "mem=256M". (Try "man bootparam" or see the documentation of
1387506f1d07SSam Ravnborg	  your boot loader (lilo or loadlin) about how to pass options to the
1388506f1d07SSam Ravnborg	  kernel at boot time.)
1389506f1d07SSam Ravnborg
1390506f1d07SSam Ravnborg	  If unsure, say "off".
1391506f1d07SSam Ravnborg
1392506f1d07SSam Ravnborgconfig HIGHMEM4G
1393506f1d07SSam Ravnborg	bool "4GB"
13948f9ca475SIngo Molnar	---help---
1395506f1d07SSam Ravnborg	  Select this if you have a 32-bit processor and between 1 and 4
1396506f1d07SSam Ravnborg	  gigabytes of physical RAM.
1397506f1d07SSam Ravnborg
1398506f1d07SSam Ravnborgconfig HIGHMEM64G
1399506f1d07SSam Ravnborg	bool "64GB"
140069b8d3fcSMatthew Whitehead	depends on !M486 && !M586 && !M586TSC && !M586MMX && !MGEODE_LX && !MGEODEGX1 && !MCYRIXIII && !MELAN && !MWINCHIPC6 && !WINCHIP3D && !MK6
1401506f1d07SSam Ravnborg	select X86_PAE
14028f9ca475SIngo Molnar	---help---
1403506f1d07SSam Ravnborg	  Select this if you have a 32-bit processor and more than 4
1404506f1d07SSam Ravnborg	  gigabytes of physical RAM.
1405506f1d07SSam Ravnborg
1406506f1d07SSam Ravnborgendchoice
1407506f1d07SSam Ravnborg
1408506f1d07SSam Ravnborgchoice
14096a108a14SDavid Rientjes	prompt "Memory split" if EXPERT
1410506f1d07SSam Ravnborg	default VMSPLIT_3G
1411506f1d07SSam Ravnborg	depends on X86_32
14128f9ca475SIngo Molnar	---help---
1413506f1d07SSam Ravnborg	  Select the desired split between kernel and user memory.
1414506f1d07SSam Ravnborg
1415506f1d07SSam Ravnborg	  If the address range available to the kernel is less than the
1416506f1d07SSam Ravnborg	  physical memory installed, the remaining memory will be available
1417506f1d07SSam Ravnborg	  as "high memory". Accessing high memory is a little more costly
1418506f1d07SSam Ravnborg	  than low memory, as it needs to be mapped into the kernel first.
1419506f1d07SSam Ravnborg	  Note that increasing the kernel address space limits the range
1420506f1d07SSam Ravnborg	  available to user programs, making the address space there
1421506f1d07SSam Ravnborg	  tighter.  Selecting anything other than the default 3G/1G split
1422506f1d07SSam Ravnborg	  will also likely make your kernel incompatible with binary-only
1423506f1d07SSam Ravnborg	  kernel modules.
1424506f1d07SSam Ravnborg
1425506f1d07SSam Ravnborg	  If you are not absolutely sure what you are doing, leave this
1426506f1d07SSam Ravnborg	  option alone!
1427506f1d07SSam Ravnborg
1428506f1d07SSam Ravnborg	config VMSPLIT_3G
1429506f1d07SSam Ravnborg		bool "3G/1G user/kernel split"
1430506f1d07SSam Ravnborg	config VMSPLIT_3G_OPT
1431506f1d07SSam Ravnborg		depends on !X86_PAE
1432506f1d07SSam Ravnborg		bool "3G/1G user/kernel split (for full 1G low memory)"
1433506f1d07SSam Ravnborg	config VMSPLIT_2G
1434506f1d07SSam Ravnborg		bool "2G/2G user/kernel split"
1435506f1d07SSam Ravnborg	config VMSPLIT_2G_OPT
1436506f1d07SSam Ravnborg		depends on !X86_PAE
1437506f1d07SSam Ravnborg		bool "2G/2G user/kernel split (for full 2G low memory)"
1438506f1d07SSam Ravnborg	config VMSPLIT_1G
1439506f1d07SSam Ravnborg		bool "1G/3G user/kernel split"
1440506f1d07SSam Ravnborgendchoice
1441506f1d07SSam Ravnborg
1442506f1d07SSam Ravnborgconfig PAGE_OFFSET
1443506f1d07SSam Ravnborg	hex
1444506f1d07SSam Ravnborg	default 0xB0000000 if VMSPLIT_3G_OPT
1445506f1d07SSam Ravnborg	default 0x80000000 if VMSPLIT_2G
1446506f1d07SSam Ravnborg	default 0x78000000 if VMSPLIT_2G_OPT
1447506f1d07SSam Ravnborg	default 0x40000000 if VMSPLIT_1G
1448506f1d07SSam Ravnborg	default 0xC0000000
1449506f1d07SSam Ravnborg	depends on X86_32
1450506f1d07SSam Ravnborg
1451506f1d07SSam Ravnborgconfig HIGHMEM
14523c2362e6SHarvey Harrison	def_bool y
1453506f1d07SSam Ravnborg	depends on X86_32 && (HIGHMEM64G || HIGHMEM4G)
1454506f1d07SSam Ravnborg
1455506f1d07SSam Ravnborgconfig X86_PAE
14569ba16087SJan Beulich	bool "PAE (Physical Address Extension) Support"
1457506f1d07SSam Ravnborg	depends on X86_32 && !HIGHMEM4G
1458d4a451d5SChristoph Hellwig	select PHYS_ADDR_T_64BIT
14599d99c712SChristian Melki	select SWIOTLB
14608f9ca475SIngo Molnar	---help---
1461506f1d07SSam Ravnborg	  PAE is required for NX support, and furthermore enables
1462506f1d07SSam Ravnborg	  larger swapspace support for non-overcommit purposes. It
1463506f1d07SSam Ravnborg	  has the cost of more pagetable lookup overhead, and also
1464506f1d07SSam Ravnborg	  consumes more pagetable space per process.
1465506f1d07SSam Ravnborg
146677ef56e4SKirill A. Shutemovconfig X86_5LEVEL
146777ef56e4SKirill A. Shutemov	bool "Enable 5-level page tables support"
1468eedb92abSKirill A. Shutemov	select DYNAMIC_MEMORY_LAYOUT
1469162434e7SKirill A. Shutemov	select SPARSEMEM_VMEMMAP
147077ef56e4SKirill A. Shutemov	depends on X86_64
147177ef56e4SKirill A. Shutemov	---help---
147277ef56e4SKirill A. Shutemov	  5-level paging enables access to larger address space:
147377ef56e4SKirill A. Shutemov	  upto 128 PiB of virtual address space and 4 PiB of
147477ef56e4SKirill A. Shutemov	  physical address space.
147577ef56e4SKirill A. Shutemov
147677ef56e4SKirill A. Shutemov	  It will be supported by future Intel CPUs.
147777ef56e4SKirill A. Shutemov
14786657fca0SKirill A. Shutemov	  A kernel with the option enabled can be booted on machines that
14796657fca0SKirill A. Shutemov	  support 4- or 5-level paging.
148077ef56e4SKirill A. Shutemov
148177ef56e4SKirill A. Shutemov	  See Documentation/x86/x86_64/5level-paging.txt for more
148277ef56e4SKirill A. Shutemov	  information.
148377ef56e4SKirill A. Shutemov
148477ef56e4SKirill A. Shutemov	  Say N if unsure.
148577ef56e4SKirill A. Shutemov
148610971ab2SIngo Molnarconfig X86_DIRECT_GBPAGES
1487e5008abeSLuis R. Rodriguez	def_bool y
14884675ff05SLevin, Alexander (Sasha Levin)	depends on X86_64 && !DEBUG_PAGEALLOC
14898f9ca475SIngo Molnar	---help---
149010971ab2SIngo Molnar	  Certain kernel features effectively disable kernel
149110971ab2SIngo Molnar	  linear 1 GB mappings (even if the CPU otherwise
149210971ab2SIngo Molnar	  supports them), so don't confuse the user by printing
149310971ab2SIngo Molnar	  that we have them enabled.
14949e899816SNick Piggin
14957744ccdbSTom Lendackyconfig ARCH_HAS_MEM_ENCRYPT
14967744ccdbSTom Lendacky	def_bool y
14977744ccdbSTom Lendacky
14987744ccdbSTom Lendackyconfig AMD_MEM_ENCRYPT
14997744ccdbSTom Lendacky	bool "AMD Secure Memory Encryption (SME) support"
15007744ccdbSTom Lendacky	depends on X86_64 && CPU_SUP_AMD
150194d49eb3SKirill A. Shutemov	select DYNAMIC_PHYSICAL_MASK
15027744ccdbSTom Lendacky	---help---
15037744ccdbSTom Lendacky	  Say yes to enable support for the encryption of system memory.
15047744ccdbSTom Lendacky	  This requires an AMD processor that supports Secure Memory
15057744ccdbSTom Lendacky	  Encryption (SME).
15067744ccdbSTom Lendacky
15077744ccdbSTom Lendackyconfig AMD_MEM_ENCRYPT_ACTIVE_BY_DEFAULT
15087744ccdbSTom Lendacky	bool "Activate AMD Secure Memory Encryption (SME) by default"
15097744ccdbSTom Lendacky	default y
15107744ccdbSTom Lendacky	depends on AMD_MEM_ENCRYPT
15117744ccdbSTom Lendacky	---help---
15127744ccdbSTom Lendacky	  Say yes to have system memory encrypted by default if running on
15137744ccdbSTom Lendacky	  an AMD processor that supports Secure Memory Encryption (SME).
15147744ccdbSTom Lendacky
15157744ccdbSTom Lendacky	  If set to Y, then the encryption of system memory can be
15167744ccdbSTom Lendacky	  deactivated with the mem_encrypt=off command line option.
15177744ccdbSTom Lendacky
15187744ccdbSTom Lendacky	  If set to N, then the encryption of system memory can be
15197744ccdbSTom Lendacky	  activated with the mem_encrypt=on command line option.
15207744ccdbSTom Lendacky
1521f88a68faSTom Lendackyconfig ARCH_USE_MEMREMAP_PROT
1522f88a68faSTom Lendacky	def_bool y
1523f88a68faSTom Lendacky	depends on AMD_MEM_ENCRYPT
1524f88a68faSTom Lendacky
1525506f1d07SSam Ravnborg# Common NUMA Features
1526506f1d07SSam Ravnborgconfig NUMA
1527fd51b2d7SKOSAKI Motohiro	bool "Numa Memory Allocation and Scheduler Support"
1528506f1d07SSam Ravnborg	depends on SMP
1529b5660ba7SH. Peter Anvin	depends on X86_64 || (X86_32 && HIGHMEM64G && X86_BIGSMP)
1530b5660ba7SH. Peter Anvin	default y if X86_BIGSMP
15318f9ca475SIngo Molnar	---help---
1532506f1d07SSam Ravnborg	  Enable NUMA (Non Uniform Memory Access) support.
1533fd51b2d7SKOSAKI Motohiro
1534506f1d07SSam Ravnborg	  The kernel will try to allocate memory used by a CPU on the
1535506f1d07SSam Ravnborg	  local memory controller of the CPU and add some more
1536506f1d07SSam Ravnborg	  NUMA awareness to the kernel.
1537506f1d07SSam Ravnborg
1538c280ea5eSIngo Molnar	  For 64-bit this is recommended if the system is Intel Core i7
1539fd51b2d7SKOSAKI Motohiro	  (or later), AMD Opteron, or EM64T NUMA.
1540fd51b2d7SKOSAKI Motohiro
1541b5660ba7SH. Peter Anvin	  For 32-bit this is only needed if you boot a 32-bit
15427cf6c945SDavid Rientjes	  kernel on a 64-bit NUMA platform.
1543fd51b2d7SKOSAKI Motohiro
1544fd51b2d7SKOSAKI Motohiro	  Otherwise, you should say N.
1545506f1d07SSam Ravnborg
1546eec1d4faSHans Rosenfeldconfig AMD_NUMA
15473c2362e6SHarvey Harrison	def_bool y
15483c2362e6SHarvey Harrison	prompt "Old style AMD Opteron NUMA detection"
15495da0ef9aSTejun Heo	depends on X86_64 && NUMA && PCI
15508f9ca475SIngo Molnar	---help---
1551eec1d4faSHans Rosenfeld	  Enable AMD NUMA node topology detection.  You should say Y here if
1552eec1d4faSHans Rosenfeld	  you have a multi processor AMD system. This uses an old method to
1553eec1d4faSHans Rosenfeld	  read the NUMA configuration directly from the builtin Northbridge
1554eec1d4faSHans Rosenfeld	  of Opteron. It is recommended to use X86_64_ACPI_NUMA instead,
1555eec1d4faSHans Rosenfeld	  which also takes priority if both are compiled in.
1556506f1d07SSam Ravnborg
1557506f1d07SSam Ravnborgconfig X86_64_ACPI_NUMA
15583c2362e6SHarvey Harrison	def_bool y
15593c2362e6SHarvey Harrison	prompt "ACPI NUMA detection"
1560506f1d07SSam Ravnborg	depends on X86_64 && NUMA && ACPI && PCI
1561506f1d07SSam Ravnborg	select ACPI_NUMA
15628f9ca475SIngo Molnar	---help---
1563506f1d07SSam Ravnborg	  Enable ACPI SRAT based node topology detection.
1564506f1d07SSam Ravnborg
15656ec6e0d9SSuresh Siddha# Some NUMA nodes have memory ranges that span
15666ec6e0d9SSuresh Siddha# other nodes.  Even though a pfn is valid and
15676ec6e0d9SSuresh Siddha# between a node's start and end pfns, it may not
15686ec6e0d9SSuresh Siddha# reside on that node.  See memmap_init_zone()
15696ec6e0d9SSuresh Siddha# for details.
15706ec6e0d9SSuresh Siddhaconfig NODES_SPAN_OTHER_NODES
15716ec6e0d9SSuresh Siddha	def_bool y
15726ec6e0d9SSuresh Siddha	depends on X86_64_ACPI_NUMA
15736ec6e0d9SSuresh Siddha
1574506f1d07SSam Ravnborgconfig NUMA_EMU
1575506f1d07SSam Ravnborg	bool "NUMA emulation"
15761b7e03efSTejun Heo	depends on NUMA
15778f9ca475SIngo Molnar	---help---
1578506f1d07SSam Ravnborg	  Enable NUMA emulation. A flat machine will be split
1579506f1d07SSam Ravnborg	  into virtual nodes when booted with "numa=fake=N", where N is the
1580506f1d07SSam Ravnborg	  number of nodes. This is only useful for debugging.
1581506f1d07SSam Ravnborg
1582506f1d07SSam Ravnborgconfig NODES_SHIFT
1583d25e26b6SLinus Torvalds	int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP
158451591e31SDavid Rientjes	range 1 10
158551591e31SDavid Rientjes	default "10" if MAXSMP
1586506f1d07SSam Ravnborg	default "6" if X86_64
1587506f1d07SSam Ravnborg	default "3"
1588506f1d07SSam Ravnborg	depends on NEED_MULTIPLE_NODES
15898f9ca475SIngo Molnar	---help---
15901184dc2fSMike Travis	  Specify the maximum number of NUMA Nodes available on the target
1591692105b8SMatt LaPlante	  system.  Increases memory reserved to accommodate various tables.
1592506f1d07SSam Ravnborg
1593506f1d07SSam Ravnborgconfig ARCH_HAVE_MEMORY_PRESENT
15943c2362e6SHarvey Harrison	def_bool y
1595506f1d07SSam Ravnborg	depends on X86_32 && DISCONTIGMEM
1596506f1d07SSam Ravnborg
1597506f1d07SSam Ravnborgconfig ARCH_FLATMEM_ENABLE
1598506f1d07SSam Ravnborg	def_bool y
15993b16651fSTejun Heo	depends on X86_32 && !NUMA
1600506f1d07SSam Ravnborg
1601506f1d07SSam Ravnborgconfig ARCH_DISCONTIGMEM_ENABLE
1602506f1d07SSam Ravnborg	def_bool y
1603b263295dSChristoph Lameter	depends on NUMA && X86_32
1604506f1d07SSam Ravnborg
1605506f1d07SSam Ravnborgconfig ARCH_DISCONTIGMEM_DEFAULT
1606506f1d07SSam Ravnborg	def_bool y
1607b263295dSChristoph Lameter	depends on NUMA && X86_32
1608b263295dSChristoph Lameter
1609506f1d07SSam Ravnborgconfig ARCH_SPARSEMEM_ENABLE
1610506f1d07SSam Ravnborg	def_bool y
16116ea30386SKees Cook	depends on X86_64 || NUMA || X86_32 || X86_32_NON_STANDARD
1612506f1d07SSam Ravnborg	select SPARSEMEM_STATIC if X86_32
1613506f1d07SSam Ravnborg	select SPARSEMEM_VMEMMAP_ENABLE if X86_64
1614506f1d07SSam Ravnborg
16153b16651fSTejun Heoconfig ARCH_SPARSEMEM_DEFAULT
16163b16651fSTejun Heo	def_bool y
16173b16651fSTejun Heo	depends on X86_64
16183b16651fSTejun Heo
1619506f1d07SSam Ravnborgconfig ARCH_SELECT_MEMORY_MODEL
1620506f1d07SSam Ravnborg	def_bool y
1621b263295dSChristoph Lameter	depends on ARCH_SPARSEMEM_ENABLE
1622506f1d07SSam Ravnborg
1623506f1d07SSam Ravnborgconfig ARCH_MEMORY_PROBE
1624a0842b70SToshi Kani	bool "Enable sysfs memory/probe interface"
16253120e25eSJan Beulich	depends on X86_64 && MEMORY_HOTPLUG
1626a0842b70SToshi Kani	help
1627a0842b70SToshi Kani	  This option enables a sysfs memory/probe interface for testing.
1628a0842b70SToshi Kani	  See Documentation/memory-hotplug.txt for more information.
1629a0842b70SToshi Kani	  If you are unsure how to answer this question, answer N.
1630506f1d07SSam Ravnborg
16313b16651fSTejun Heoconfig ARCH_PROC_KCORE_TEXT
16323b16651fSTejun Heo	def_bool y
16333b16651fSTejun Heo	depends on X86_64 && PROC_KCORE
16343b16651fSTejun Heo
1635a29815a3SAvi Kivityconfig ILLEGAL_POINTER_VALUE
1636a29815a3SAvi Kivity       hex
1637a29815a3SAvi Kivity       default 0 if X86_32
1638a29815a3SAvi Kivity       default 0xdead000000000000 if X86_64
1639a29815a3SAvi Kivity
16407a67832cSDan Williamsconfig X86_PMEM_LEGACY_DEVICE
16417a67832cSDan Williams	bool
16427a67832cSDan Williams
1643ec776ef6SChristoph Hellwigconfig X86_PMEM_LEGACY
16447a67832cSDan Williams	tristate "Support non-standard NVDIMMs and ADR protected memory"
16459f53f9faSDan Williams	depends on PHYS_ADDR_T_64BIT
16469f53f9faSDan Williams	depends on BLK_DEV
16477a67832cSDan Williams	select X86_PMEM_LEGACY_DEVICE
16489f53f9faSDan Williams	select LIBNVDIMM
1649ec776ef6SChristoph Hellwig	help
1650ec776ef6SChristoph Hellwig	  Treat memory marked using the non-standard e820 type of 12 as used
1651ec776ef6SChristoph Hellwig	  by the Intel Sandy Bridge-EP reference BIOS as protected memory.
1652ec776ef6SChristoph Hellwig	  The kernel will offer these regions to the 'pmem' driver so
1653ec776ef6SChristoph Hellwig	  they can be used for persistent storage.
1654ec776ef6SChristoph Hellwig
1655ec776ef6SChristoph Hellwig	  Say Y if unsure.
1656ec776ef6SChristoph Hellwig
1657506f1d07SSam Ravnborgconfig HIGHPTE
1658506f1d07SSam Ravnborg	bool "Allocate 3rd-level pagetables from highmem"
16596fc108a0SJan Beulich	depends on HIGHMEM
16608f9ca475SIngo Molnar	---help---
1661506f1d07SSam Ravnborg	  The VM uses one page table entry for each page of physical memory.
1662506f1d07SSam Ravnborg	  For systems with a lot of RAM, this can be wasteful of precious
1663506f1d07SSam Ravnborg	  low memory.  Setting this option will put user-space page table
1664506f1d07SSam Ravnborg	  entries in high memory.
1665506f1d07SSam Ravnborg
16669f077871SJeremy Fitzhardingeconfig X86_CHECK_BIOS_CORRUPTION
16679f077871SJeremy Fitzhardinge	bool "Check for low memory corruption"
16688f9ca475SIngo Molnar	---help---
16699f077871SJeremy Fitzhardinge	  Periodically check for memory corruption in low memory, which
16709f077871SJeremy Fitzhardinge	  is suspected to be caused by BIOS.  Even when enabled in the
16719f077871SJeremy Fitzhardinge	  configuration, it is disabled at runtime.  Enable it by
16729f077871SJeremy Fitzhardinge	  setting "memory_corruption_check=1" on the kernel command
16739f077871SJeremy Fitzhardinge	  line.  By default it scans the low 64k of memory every 60
16749f077871SJeremy Fitzhardinge	  seconds; see the memory_corruption_check_size and
16759f077871SJeremy Fitzhardinge	  memory_corruption_check_period parameters in
16768c27ceffSMauro Carvalho Chehab	  Documentation/admin-guide/kernel-parameters.rst to adjust this.
16779f077871SJeremy Fitzhardinge
16789f077871SJeremy Fitzhardinge	  When enabled with the default parameters, this option has
16799f077871SJeremy Fitzhardinge	  almost no overhead, as it reserves a relatively small amount
16809f077871SJeremy Fitzhardinge	  of memory and scans it infrequently.  It both detects corruption
16819f077871SJeremy Fitzhardinge	  and prevents it from affecting the running system.
16829f077871SJeremy Fitzhardinge
16839f077871SJeremy Fitzhardinge	  It is, however, intended as a diagnostic tool; if repeatable
16849f077871SJeremy Fitzhardinge	  BIOS-originated corruption always affects the same memory,
16859f077871SJeremy Fitzhardinge	  you can use memmap= to prevent the kernel from using that
16869f077871SJeremy Fitzhardinge	  memory.
16879f077871SJeremy Fitzhardinge
1688c885df50SJeremy Fitzhardingeconfig X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK
1689c885df50SJeremy Fitzhardinge	bool "Set the default setting of memory_corruption_check"
1690c885df50SJeremy Fitzhardinge	depends on X86_CHECK_BIOS_CORRUPTION
1691c885df50SJeremy Fitzhardinge	default y
16928f9ca475SIngo Molnar	---help---
1693c885df50SJeremy Fitzhardinge	  Set whether the default state of memory_corruption_check is
1694c885df50SJeremy Fitzhardinge	  on or off.
1695c885df50SJeremy Fitzhardinge
16969ea77bdbSH. Peter Anvinconfig X86_RESERVE_LOW
1697d0cd7425SH. Peter Anvin	int "Amount of low memory, in kilobytes, to reserve for the BIOS"
1698d0cd7425SH. Peter Anvin	default 64
1699d0cd7425SH. Peter Anvin	range 4 640
17008f9ca475SIngo Molnar	---help---
1701d0cd7425SH. Peter Anvin	  Specify the amount of low memory to reserve for the BIOS.
1702fc381519SIngo Molnar
1703d0cd7425SH. Peter Anvin	  The first page contains BIOS data structures that the kernel
1704d0cd7425SH. Peter Anvin	  must not use, so that page must always be reserved.
1705fc381519SIngo Molnar
1706d0cd7425SH. Peter Anvin	  By default we reserve the first 64K of physical RAM, as a
1707d0cd7425SH. Peter Anvin	  number of BIOSes are known to corrupt that memory range
1708d0cd7425SH. Peter Anvin	  during events such as suspend/resume or monitor cable
1709d0cd7425SH. Peter Anvin	  insertion, so it must not be used by the kernel.
1710fc381519SIngo Molnar
1711d0cd7425SH. Peter Anvin	  You can set this to 4 if you are absolutely sure that you
1712d0cd7425SH. Peter Anvin	  trust the BIOS to get all its memory reservations and usages
1713d0cd7425SH. Peter Anvin	  right.  If you know your BIOS have problems beyond the
1714d0cd7425SH. Peter Anvin	  default 64K area, you can set this to 640 to avoid using the
1715d0cd7425SH. Peter Anvin	  entire low memory range.
1716d0cd7425SH. Peter Anvin
1717d0cd7425SH. Peter Anvin	  If you have doubts about the BIOS (e.g. suspend/resume does
1718d0cd7425SH. Peter Anvin	  not work or there's kernel crashes after certain hardware
1719d0cd7425SH. Peter Anvin	  hotplug events) then you might want to enable
1720d0cd7425SH. Peter Anvin	  X86_CHECK_BIOS_CORRUPTION=y to allow the kernel to check
1721d0cd7425SH. Peter Anvin	  typical corruption patterns.
1722d0cd7425SH. Peter Anvin
1723d0cd7425SH. Peter Anvin	  Leave this to the default value of 64 if you are unsure.
1724fc381519SIngo Molnar
1725506f1d07SSam Ravnborgconfig MATH_EMULATION
1726506f1d07SSam Ravnborg	bool
1727a5b9e5a2SAndy Lutomirski	depends on MODIFY_LDT_SYSCALL
1728506f1d07SSam Ravnborg	prompt "Math emulation" if X86_32
1729506f1d07SSam Ravnborg	---help---
1730506f1d07SSam Ravnborg	  Linux can emulate a math coprocessor (used for floating point
1731506f1d07SSam Ravnborg	  operations) if you don't have one. 486DX and Pentium processors have
1732506f1d07SSam Ravnborg	  a math coprocessor built in, 486SX and 386 do not, unless you added
1733506f1d07SSam Ravnborg	  a 487DX or 387, respectively. (The messages during boot time can
1734506f1d07SSam Ravnborg	  give you some hints here ["man dmesg"].) Everyone needs either a
1735506f1d07SSam Ravnborg	  coprocessor or this emulation.
1736506f1d07SSam Ravnborg
1737506f1d07SSam Ravnborg	  If you don't have a math coprocessor, you need to say Y here; if you
1738506f1d07SSam Ravnborg	  say Y here even though you have a coprocessor, the coprocessor will
1739506f1d07SSam Ravnborg	  be used nevertheless. (This behavior can be changed with the kernel
1740506f1d07SSam Ravnborg	  command line option "no387", which comes handy if your coprocessor
1741506f1d07SSam Ravnborg	  is broken. Try "man bootparam" or see the documentation of your boot
1742506f1d07SSam Ravnborg	  loader (lilo or loadlin) about how to pass options to the kernel at
1743506f1d07SSam Ravnborg	  boot time.) This means that it is a good idea to say Y here if you
1744506f1d07SSam Ravnborg	  intend to use this kernel on different machines.
1745506f1d07SSam Ravnborg
1746506f1d07SSam Ravnborg	  More information about the internals of the Linux math coprocessor
1747506f1d07SSam Ravnborg	  emulation can be found in <file:arch/x86/math-emu/README>.
1748506f1d07SSam Ravnborg
1749506f1d07SSam Ravnborg	  If you are not sure, say Y; apart from resulting in a 66 KB bigger
1750506f1d07SSam Ravnborg	  kernel, it won't hurt.
1751506f1d07SSam Ravnborg
1752506f1d07SSam Ravnborgconfig MTRR
17536fc108a0SJan Beulich	def_bool y
17546a108a14SDavid Rientjes	prompt "MTRR (Memory Type Range Register) support" if EXPERT
1755506f1d07SSam Ravnborg	---help---
1756506f1d07SSam Ravnborg	  On Intel P6 family processors (Pentium Pro, Pentium II and later)
1757506f1d07SSam Ravnborg	  the Memory Type Range Registers (MTRRs) may be used to control
1758506f1d07SSam Ravnborg	  processor access to memory ranges. This is most useful if you have
1759506f1d07SSam Ravnborg	  a video (VGA) card on a PCI or AGP bus. Enabling write-combining
1760506f1d07SSam Ravnborg	  allows bus write transfers to be combined into a larger transfer
1761506f1d07SSam Ravnborg	  before bursting over the PCI/AGP bus. This can increase performance
1762506f1d07SSam Ravnborg	  of image write operations 2.5 times or more. Saying Y here creates a
1763506f1d07SSam Ravnborg	  /proc/mtrr file which may be used to manipulate your processor's
1764506f1d07SSam Ravnborg	  MTRRs. Typically the X server should use this.
1765506f1d07SSam Ravnborg
1766506f1d07SSam Ravnborg	  This code has a reasonably generic interface so that similar
1767506f1d07SSam Ravnborg	  control registers on other processors can be easily supported
1768506f1d07SSam Ravnborg	  as well:
1769506f1d07SSam Ravnborg
1770506f1d07SSam Ravnborg	  The Cyrix 6x86, 6x86MX and M II processors have Address Range
1771506f1d07SSam Ravnborg	  Registers (ARRs) which provide a similar functionality to MTRRs. For
1772506f1d07SSam Ravnborg	  these, the ARRs are used to emulate the MTRRs.
1773506f1d07SSam Ravnborg	  The AMD K6-2 (stepping 8 and above) and K6-3 processors have two
1774506f1d07SSam Ravnborg	  MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing
1775506f1d07SSam Ravnborg	  write-combining. All of these processors are supported by this code
1776506f1d07SSam Ravnborg	  and it makes sense to say Y here if you have one of them.
1777506f1d07SSam Ravnborg
1778506f1d07SSam Ravnborg	  Saying Y here also fixes a problem with buggy SMP BIOSes which only
1779506f1d07SSam Ravnborg	  set the MTRRs for the boot CPU and not for the secondary CPUs. This
1780506f1d07SSam Ravnborg	  can lead to all sorts of problems, so it's good to say Y here.
1781506f1d07SSam Ravnborg
1782506f1d07SSam Ravnborg	  You can safely say Y even if your machine doesn't have MTRRs, you'll
1783506f1d07SSam Ravnborg	  just add about 9 KB to your kernel.
1784506f1d07SSam Ravnborg
17857225e751SRandy Dunlap	  See <file:Documentation/x86/mtrr.txt> for more information.
1786506f1d07SSam Ravnborg
178795ffa243SYinghai Luconfig MTRR_SANITIZER
17882ffb3501SYinghai Lu	def_bool y
178995ffa243SYinghai Lu	prompt "MTRR cleanup support"
179095ffa243SYinghai Lu	depends on MTRR
17918f9ca475SIngo Molnar	---help---
1792aba3728cSThomas Gleixner	  Convert MTRR layout from continuous to discrete, so X drivers can
1793aba3728cSThomas Gleixner	  add writeback entries.
179495ffa243SYinghai Lu
1795aba3728cSThomas Gleixner	  Can be disabled with disable_mtrr_cleanup on the kernel command line.
1796692105b8SMatt LaPlante	  The largest mtrr entry size for a continuous block can be set with
1797aba3728cSThomas Gleixner	  mtrr_chunk_size.
179895ffa243SYinghai Lu
17992ffb3501SYinghai Lu	  If unsure, say Y.
180095ffa243SYinghai Lu
180195ffa243SYinghai Luconfig MTRR_SANITIZER_ENABLE_DEFAULT
1802f5098d62SYinghai Lu	int "MTRR cleanup enable value (0-1)"
1803f5098d62SYinghai Lu	range 0 1
1804f5098d62SYinghai Lu	default "0"
180595ffa243SYinghai Lu	depends on MTRR_SANITIZER
18068f9ca475SIngo Molnar	---help---
1807f5098d62SYinghai Lu	  Enable mtrr cleanup default value
180895ffa243SYinghai Lu
180912031a62SYinghai Luconfig MTRR_SANITIZER_SPARE_REG_NR_DEFAULT
181012031a62SYinghai Lu	int "MTRR cleanup spare reg num (0-7)"
181112031a62SYinghai Lu	range 0 7
181212031a62SYinghai Lu	default "1"
181312031a62SYinghai Lu	depends on MTRR_SANITIZER
18148f9ca475SIngo Molnar	---help---
181512031a62SYinghai Lu	  mtrr cleanup spare entries default, it can be changed via
1816aba3728cSThomas Gleixner	  mtrr_spare_reg_nr=N on the kernel command line.
181712031a62SYinghai Lu
18182e5d9c85Svenkatesh.pallipadi@intel.comconfig X86_PAT
18196fc108a0SJan Beulich	def_bool y
18206a108a14SDavid Rientjes	prompt "x86 PAT support" if EXPERT
18212a8a2719SIngo Molnar	depends on MTRR
18228f9ca475SIngo Molnar	---help---
18232e5d9c85Svenkatesh.pallipadi@intel.com	  Use PAT attributes to setup page level cache control.
1824042b78e4SVenki Pallipadi
18252e5d9c85Svenkatesh.pallipadi@intel.com	  PATs are the modern equivalents of MTRRs and are much more
18262e5d9c85Svenkatesh.pallipadi@intel.com	  flexible than MTRRs.
18272e5d9c85Svenkatesh.pallipadi@intel.com
18282e5d9c85Svenkatesh.pallipadi@intel.com	  Say N here if you see bootup problems (boot crash, boot hang,
1829042b78e4SVenki Pallipadi	  spontaneous reboots) or a non-working video driver.
18302e5d9c85Svenkatesh.pallipadi@intel.com
18312e5d9c85Svenkatesh.pallipadi@intel.com	  If unsure, say Y.
18322e5d9c85Svenkatesh.pallipadi@intel.com
183346cf98cdSVenkatesh Pallipadiconfig ARCH_USES_PG_UNCACHED
183446cf98cdSVenkatesh Pallipadi	def_bool y
183546cf98cdSVenkatesh Pallipadi	depends on X86_PAT
183646cf98cdSVenkatesh Pallipadi
1837628c6246SH. Peter Anvinconfig ARCH_RANDOM
1838628c6246SH. Peter Anvin	def_bool y
1839628c6246SH. Peter Anvin	prompt "x86 architectural random number generator" if EXPERT
1840628c6246SH. Peter Anvin	---help---
1841628c6246SH. Peter Anvin	  Enable the x86 architectural RDRAND instruction
1842628c6246SH. Peter Anvin	  (Intel Bull Mountain technology) to generate random numbers.
1843628c6246SH. Peter Anvin	  If supported, this is a high bandwidth, cryptographically
1844628c6246SH. Peter Anvin	  secure hardware random number generator.
1845628c6246SH. Peter Anvin
184651ae4a2dSH. Peter Anvinconfig X86_SMAP
184751ae4a2dSH. Peter Anvin	def_bool y
184851ae4a2dSH. Peter Anvin	prompt "Supervisor Mode Access Prevention" if EXPERT
184951ae4a2dSH. Peter Anvin	---help---
185051ae4a2dSH. Peter Anvin	  Supervisor Mode Access Prevention (SMAP) is a security
185151ae4a2dSH. Peter Anvin	  feature in newer Intel processors.  There is a small
185251ae4a2dSH. Peter Anvin	  performance cost if this enabled and turned on; there is
185351ae4a2dSH. Peter Anvin	  also a small increase in the kernel size if this is enabled.
185451ae4a2dSH. Peter Anvin
185551ae4a2dSH. Peter Anvin	  If unsure, say Y.
185651ae4a2dSH. Peter Anvin
1857aa35f896SRicardo Nericonfig X86_INTEL_UMIP
1858796ebc81SRicardo Neri	def_bool y
1859aa35f896SRicardo Neri	depends on CPU_SUP_INTEL
1860aa35f896SRicardo Neri	prompt "Intel User Mode Instruction Prevention" if EXPERT
1861aa35f896SRicardo Neri	---help---
1862aa35f896SRicardo Neri	  The User Mode Instruction Prevention (UMIP) is a security
1863aa35f896SRicardo Neri	  feature in newer Intel processors. If enabled, a general
1864796ebc81SRicardo Neri	  protection fault is issued if the SGDT, SLDT, SIDT, SMSW
1865796ebc81SRicardo Neri	  or STR instructions are executed in user mode. These instructions
1866796ebc81SRicardo Neri	  unnecessarily expose information about the hardware state.
1867796ebc81SRicardo Neri
1868796ebc81SRicardo Neri	  The vast majority of applications do not use these instructions.
1869796ebc81SRicardo Neri	  For the very few that do, software emulation is provided in
1870796ebc81SRicardo Neri	  specific cases in protected and virtual-8086 modes. Emulated
1871796ebc81SRicardo Neri	  results are dummy.
1872aa35f896SRicardo Neri
187372e9b5feSDave Hansenconfig X86_INTEL_MPX
187472e9b5feSDave Hansen	prompt "Intel MPX (Memory Protection Extensions)"
187572e9b5feSDave Hansen	def_bool n
1876df3735c5SRik van Riel	# Note: only available in 64-bit mode due to VMA flags shortage
1877df3735c5SRik van Riel	depends on CPU_SUP_INTEL && X86_64
1878df3735c5SRik van Riel	select ARCH_USES_HIGH_VMA_FLAGS
187972e9b5feSDave Hansen	---help---
188072e9b5feSDave Hansen	  MPX provides hardware features that can be used in
188172e9b5feSDave Hansen	  conjunction with compiler-instrumented code to check
188272e9b5feSDave Hansen	  memory references.  It is designed to detect buffer
188372e9b5feSDave Hansen	  overflow or underflow bugs.
188472e9b5feSDave Hansen
188572e9b5feSDave Hansen	  This option enables running applications which are
188672e9b5feSDave Hansen	  instrumented or otherwise use MPX.  It does not use MPX
188772e9b5feSDave Hansen	  itself inside the kernel or to protect the kernel
188872e9b5feSDave Hansen	  against bad memory references.
188972e9b5feSDave Hansen
189072e9b5feSDave Hansen	  Enabling this option will make the kernel larger:
189172e9b5feSDave Hansen	  ~8k of kernel text and 36 bytes of data on a 64-bit
189272e9b5feSDave Hansen	  defconfig.  It adds a long to the 'mm_struct' which
189372e9b5feSDave Hansen	  will increase the kernel memory overhead of each
189472e9b5feSDave Hansen	  process and adds some branches to paths used during
189572e9b5feSDave Hansen	  exec() and munmap().
189672e9b5feSDave Hansen
189772e9b5feSDave Hansen	  For details, see Documentation/x86/intel_mpx.txt
189872e9b5feSDave Hansen
189972e9b5feSDave Hansen	  If unsure, say N.
190072e9b5feSDave Hansen
190135e97790SDave Hansenconfig X86_INTEL_MEMORY_PROTECTION_KEYS
1902284244a9SDave Hansen	prompt "Intel Memory Protection Keys"
190335e97790SDave Hansen	def_bool y
1904284244a9SDave Hansen	# Note: only available in 64-bit mode
190535e97790SDave Hansen	depends on CPU_SUP_INTEL && X86_64
190652c8e601SIngo Molnar	select ARCH_USES_HIGH_VMA_FLAGS
190752c8e601SIngo Molnar	select ARCH_HAS_PKEYS
1908284244a9SDave Hansen	---help---
1909284244a9SDave Hansen	  Memory Protection Keys provides a mechanism for enforcing
1910284244a9SDave Hansen	  page-based protections, but without requiring modification of the
1911284244a9SDave Hansen	  page tables when an application changes protection domains.
1912284244a9SDave Hansen
1913284244a9SDave Hansen	  For details, see Documentation/x86/protection-keys.txt
1914284244a9SDave Hansen
1915284244a9SDave Hansen	  If unsure, say y.
191635e97790SDave Hansen
1917506f1d07SSam Ravnborgconfig EFI
19189ba16087SJan Beulich	bool "EFI runtime service support"
19195b83683fSHuang, Ying	depends on ACPI
1920f6ce5002SSergey Vlasov	select UCS2_STRING
1921022ee6c5SArd Biesheuvel	select EFI_RUNTIME_WRAPPERS
1922506f1d07SSam Ravnborg	---help---
19238b2cb7a8SHuang, Ying	  This enables the kernel to use EFI runtime services that are
1924506f1d07SSam Ravnborg	  available (such as the EFI variable services).
1925506f1d07SSam Ravnborg
19268b2cb7a8SHuang, Ying	  This option is only useful on systems that have EFI firmware.
19278b2cb7a8SHuang, Ying	  In addition, you should use the latest ELILO loader available
19288b2cb7a8SHuang, Ying	  at <http://elilo.sourceforge.net> in order to take advantage
19298b2cb7a8SHuang, Ying	  of EFI runtime services. However, even with this option, the
19308b2cb7a8SHuang, Ying	  resultant kernel should continue to boot on existing non-EFI
19318b2cb7a8SHuang, Ying	  platforms.
1932506f1d07SSam Ravnborg
1933291f3632SMatt Flemingconfig EFI_STUB
1934291f3632SMatt Fleming       bool "EFI stub support"
1935b16d8c23SMatt Fleming       depends on EFI && !X86_USE_3DNOW
19367b2a583aSMatt Fleming       select RELOCATABLE
1937291f3632SMatt Fleming       ---help---
1938291f3632SMatt Fleming          This kernel feature allows a bzImage to be loaded directly
1939291f3632SMatt Fleming	  by EFI firmware without the use of a bootloader.
1940291f3632SMatt Fleming
19414172fe2fSRoy Franz	  See Documentation/efi-stub.txt for more information.
19420c759662SMatt Fleming
19437d453eeeSMatt Flemingconfig EFI_MIXED
19447d453eeeSMatt Fleming	bool "EFI mixed-mode support"
19457d453eeeSMatt Fleming	depends on EFI_STUB && X86_64
19467d453eeeSMatt Fleming	---help---
19477d453eeeSMatt Fleming	   Enabling this feature allows a 64-bit kernel to be booted
19487d453eeeSMatt Fleming	   on a 32-bit firmware, provided that your CPU supports 64-bit
19497d453eeeSMatt Fleming	   mode.
19507d453eeeSMatt Fleming
19517d453eeeSMatt Fleming	   Note that it is not possible to boot a mixed-mode enabled
19527d453eeeSMatt Fleming	   kernel via the EFI boot stub - a bootloader that supports
19537d453eeeSMatt Fleming	   the EFI handover protocol must be used.
19547d453eeeSMatt Fleming
19557d453eeeSMatt Fleming	   If unsure, say N.
19567d453eeeSMatt Fleming
1957506f1d07SSam Ravnborgconfig SECCOMP
19583c2362e6SHarvey Harrison	def_bool y
19593c2362e6SHarvey Harrison	prompt "Enable seccomp to safely compute untrusted bytecode"
19608f9ca475SIngo Molnar	---help---
1961506f1d07SSam Ravnborg	  This kernel feature is useful for number crunching applications
1962506f1d07SSam Ravnborg	  that may need to compute untrusted bytecode during their
1963506f1d07SSam Ravnborg	  execution. By using pipes or other transports made available to
1964506f1d07SSam Ravnborg	  the process as file descriptors supporting the read/write
1965506f1d07SSam Ravnborg	  syscalls, it's possible to isolate those applications in
1966506f1d07SSam Ravnborg	  their own address space using seccomp. Once seccomp is
19679c0bbee8SAlexey Dobriyan	  enabled via prctl(PR_SET_SECCOMP), it cannot be disabled
1968506f1d07SSam Ravnborg	  and the task is only allowed to execute a few safe syscalls
1969506f1d07SSam Ravnborg	  defined by each seccomp mode.
1970506f1d07SSam Ravnborg
1971506f1d07SSam Ravnborg	  If unsure, say Y. Only embedded should say N here.
1972506f1d07SSam Ravnborg
1973506f1d07SSam Ravnborgsource kernel/Kconfig.hz
1974506f1d07SSam Ravnborg
1975506f1d07SSam Ravnborgconfig KEXEC
1976506f1d07SSam Ravnborg	bool "kexec system call"
19772965faa5SDave Young	select KEXEC_CORE
19788f9ca475SIngo Molnar	---help---
1979506f1d07SSam Ravnborg	  kexec is a system call that implements the ability to shutdown your
1980506f1d07SSam Ravnborg	  current kernel, and to start another kernel.  It is like a reboot
1981506f1d07SSam Ravnborg	  but it is independent of the system firmware.   And like a reboot
1982506f1d07SSam Ravnborg	  you can start any kernel with it, not just Linux.
1983506f1d07SSam Ravnborg
1984506f1d07SSam Ravnborg	  The name comes from the similarity to the exec system call.
1985506f1d07SSam Ravnborg
1986506f1d07SSam Ravnborg	  It is an ongoing process to be certain the hardware in a machine
1987506f1d07SSam Ravnborg	  is properly shutdown, so do not be surprised if this code does not
1988bf220695SGeert Uytterhoeven	  initially work for you.  As of this writing the exact hardware
1989bf220695SGeert Uytterhoeven	  interface is strongly in flux, so no good recommendation can be
1990bf220695SGeert Uytterhoeven	  made.
1991506f1d07SSam Ravnborg
199274ca317cSVivek Goyalconfig KEXEC_FILE
199374ca317cSVivek Goyal	bool "kexec file based system call"
19942965faa5SDave Young	select KEXEC_CORE
199574ca317cSVivek Goyal	select BUILD_BIN2C
199674ca317cSVivek Goyal	depends on X86_64
199774ca317cSVivek Goyal	depends on CRYPTO=y
199874ca317cSVivek Goyal	depends on CRYPTO_SHA256=y
199974ca317cSVivek Goyal	---help---
200074ca317cSVivek Goyal	  This is new version of kexec system call. This system call is
200174ca317cSVivek Goyal	  file based and takes file descriptors as system call argument
200274ca317cSVivek Goyal	  for kernel and initramfs as opposed to list of segments as
200374ca317cSVivek Goyal	  accepted by previous system call.
200474ca317cSVivek Goyal
2005b799a09fSAKASHI Takahiroconfig ARCH_HAS_KEXEC_PURGATORY
2006b799a09fSAKASHI Takahiro	def_bool KEXEC_FILE
2007b799a09fSAKASHI Takahiro
20088e7d8381SVivek Goyalconfig KEXEC_VERIFY_SIG
20098e7d8381SVivek Goyal	bool "Verify kernel signature during kexec_file_load() syscall"
201074ca317cSVivek Goyal	depends on KEXEC_FILE
20118e7d8381SVivek Goyal	---help---
20128e7d8381SVivek Goyal	  This option makes kernel signature verification mandatory for
2013d8eb8940SBorislav Petkov	  the kexec_file_load() syscall.
20148e7d8381SVivek Goyal
2015d8eb8940SBorislav Petkov	  In addition to that option, you need to enable signature
2016d8eb8940SBorislav Petkov	  verification for the corresponding kernel image type being
2017d8eb8940SBorislav Petkov	  loaded in order for this to work.
20188e7d8381SVivek Goyal
20198e7d8381SVivek Goyalconfig KEXEC_BZIMAGE_VERIFY_SIG
20208e7d8381SVivek Goyal	bool "Enable bzImage signature verification support"
20218e7d8381SVivek Goyal	depends on KEXEC_VERIFY_SIG
20228e7d8381SVivek Goyal	depends on SIGNED_PE_FILE_VERIFICATION
20238e7d8381SVivek Goyal	select SYSTEM_TRUSTED_KEYRING
20248e7d8381SVivek Goyal	---help---
20258e7d8381SVivek Goyal	  Enable bzImage signature verification support.
20268e7d8381SVivek Goyal
2027506f1d07SSam Ravnborgconfig CRASH_DUMP
202804b69447SPavel Machek	bool "kernel crash dumps"
2029506f1d07SSam Ravnborg	depends on X86_64 || (X86_32 && HIGHMEM)
20308f9ca475SIngo Molnar	---help---
2031506f1d07SSam Ravnborg	  Generate crash dump after being started by kexec.
2032506f1d07SSam Ravnborg	  This should be normally only set in special crash dump kernels
2033506f1d07SSam Ravnborg	  which are loaded in the main kernel with kexec-tools into
2034506f1d07SSam Ravnborg	  a specially reserved region and then later executed after
2035506f1d07SSam Ravnborg	  a crash by kdump/kexec. The crash dump kernel must be compiled
2036506f1d07SSam Ravnborg	  to a memory address not used by the main kernel or BIOS using
2037506f1d07SSam Ravnborg	  PHYSICAL_START, or it must be built as a relocatable image
2038506f1d07SSam Ravnborg	  (CONFIG_RELOCATABLE=y).
2039506f1d07SSam Ravnborg	  For more details see Documentation/kdump/kdump.txt
2040506f1d07SSam Ravnborg
20413ab83521SHuang Yingconfig KEXEC_JUMP
20426ea30386SKees Cook	bool "kexec jump"
2043fee7b0d8SHuang Ying	depends on KEXEC && HIBERNATION
20448f9ca475SIngo Molnar	---help---
204589081d17SHuang Ying	  Jump between original kernel and kexeced kernel and invoke
204689081d17SHuang Ying	  code in physical address mode via KEXEC
20473ab83521SHuang Ying
2048506f1d07SSam Ravnborgconfig PHYSICAL_START
20496a108a14SDavid Rientjes	hex "Physical address where the kernel is loaded" if (EXPERT || CRASH_DUMP)
2050ceefccc9SH. Peter Anvin	default "0x1000000"
20518f9ca475SIngo Molnar	---help---
2052506f1d07SSam Ravnborg	  This gives the physical address where the kernel is loaded.
2053506f1d07SSam Ravnborg
2054506f1d07SSam Ravnborg	  If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then
2055506f1d07SSam Ravnborg	  bzImage will decompress itself to above physical address and
2056506f1d07SSam Ravnborg	  run from there. Otherwise, bzImage will run from the address where
2057506f1d07SSam Ravnborg	  it has been loaded by the boot loader and will ignore above physical
2058506f1d07SSam Ravnborg	  address.
2059506f1d07SSam Ravnborg
2060506f1d07SSam Ravnborg	  In normal kdump cases one does not have to set/change this option
2061506f1d07SSam Ravnborg	  as now bzImage can be compiled as a completely relocatable image
2062506f1d07SSam Ravnborg	  (CONFIG_RELOCATABLE=y) and be used to load and run from a different
2063506f1d07SSam Ravnborg	  address. This option is mainly useful for the folks who don't want
2064506f1d07SSam Ravnborg	  to use a bzImage for capturing the crash dump and want to use a
2065506f1d07SSam Ravnborg	  vmlinux instead. vmlinux is not relocatable hence a kernel needs
2066506f1d07SSam Ravnborg	  to be specifically compiled to run from a specific memory area
2067506f1d07SSam Ravnborg	  (normally a reserved region) and this option comes handy.
2068506f1d07SSam Ravnborg
2069ceefccc9SH. Peter Anvin	  So if you are using bzImage for capturing the crash dump,
2070ceefccc9SH. Peter Anvin	  leave the value here unchanged to 0x1000000 and set
2071ceefccc9SH. Peter Anvin	  CONFIG_RELOCATABLE=y.  Otherwise if you plan to use vmlinux
2072ceefccc9SH. Peter Anvin	  for capturing the crash dump change this value to start of
2073ceefccc9SH. Peter Anvin	  the reserved region.  In other words, it can be set based on
2074ceefccc9SH. Peter Anvin	  the "X" value as specified in the "crashkernel=YM@XM"
2075ceefccc9SH. Peter Anvin	  command line boot parameter passed to the panic-ed
2076ceefccc9SH. Peter Anvin	  kernel. Please take a look at Documentation/kdump/kdump.txt
2077ceefccc9SH. Peter Anvin	  for more details about crash dumps.
2078506f1d07SSam Ravnborg
2079506f1d07SSam Ravnborg	  Usage of bzImage for capturing the crash dump is recommended as
2080506f1d07SSam Ravnborg	  one does not have to build two kernels. Same kernel can be used
2081506f1d07SSam Ravnborg	  as production kernel and capture kernel. Above option should have
2082506f1d07SSam Ravnborg	  gone away after relocatable bzImage support is introduced. But it
2083506f1d07SSam Ravnborg	  is present because there are users out there who continue to use
2084506f1d07SSam Ravnborg	  vmlinux for dump capture. This option should go away down the
2085506f1d07SSam Ravnborg	  line.
2086506f1d07SSam Ravnborg
2087506f1d07SSam Ravnborg	  Don't change this unless you know what you are doing.
2088506f1d07SSam Ravnborg
2089506f1d07SSam Ravnborgconfig RELOCATABLE
209026717808SH. Peter Anvin	bool "Build a relocatable kernel"
209126717808SH. Peter Anvin	default y
20928f9ca475SIngo Molnar	---help---
2093506f1d07SSam Ravnborg	  This builds a kernel image that retains relocation information
2094506f1d07SSam Ravnborg	  so it can be loaded someplace besides the default 1MB.
2095506f1d07SSam Ravnborg	  The relocations tend to make the kernel binary about 10% larger,
2096506f1d07SSam Ravnborg	  but are discarded at runtime.
2097506f1d07SSam Ravnborg
2098506f1d07SSam Ravnborg	  One use is for the kexec on panic case where the recovery kernel
2099506f1d07SSam Ravnborg	  must live at a different physical address than the primary
2100506f1d07SSam Ravnborg	  kernel.
2101506f1d07SSam Ravnborg
2102506f1d07SSam Ravnborg	  Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address
2103506f1d07SSam Ravnborg	  it has been loaded at and the compile time physical address
21048ab3820fSKees Cook	  (CONFIG_PHYSICAL_START) is used as the minimum location.
2105506f1d07SSam Ravnborg
21068ab3820fSKees Cookconfig RANDOMIZE_BASE
2107e8581e3dSBaoquan He	bool "Randomize the address of the kernel image (KASLR)"
21088ab3820fSKees Cook	depends on RELOCATABLE
21096807c846SIngo Molnar	default y
21108ab3820fSKees Cook	---help---
2111e8581e3dSBaoquan He	  In support of Kernel Address Space Layout Randomization (KASLR),
2112e8581e3dSBaoquan He	  this randomizes the physical address at which the kernel image
2113e8581e3dSBaoquan He	  is decompressed and the virtual address where the kernel
2114e8581e3dSBaoquan He	  image is mapped, as a security feature that deters exploit
2115e8581e3dSBaoquan He	  attempts relying on knowledge of the location of kernel
2116e8581e3dSBaoquan He	  code internals.
2117e8581e3dSBaoquan He
2118ed9f007eSKees Cook	  On 64-bit, the kernel physical and virtual addresses are
2119ed9f007eSKees Cook	  randomized separately. The physical address will be anywhere
2120ed9f007eSKees Cook	  between 16MB and the top of physical memory (up to 64TB). The
2121ed9f007eSKees Cook	  virtual address will be randomized from 16MB up to 1GB (9 bits
2122ed9f007eSKees Cook	  of entropy). Note that this also reduces the memory space
2123ed9f007eSKees Cook	  available to kernel modules from 1.5GB to 1GB.
2124ed9f007eSKees Cook
2125ed9f007eSKees Cook	  On 32-bit, the kernel physical and virtual addresses are
2126ed9f007eSKees Cook	  randomized together. They will be randomized from 16MB up to
2127ed9f007eSKees Cook	  512MB (8 bits of entropy).
21288ab3820fSKees Cook
2129a653f356SKees Cook	  Entropy is generated using the RDRAND instruction if it is
2130e8581e3dSBaoquan He	  supported. If RDTSC is supported, its value is mixed into
2131e8581e3dSBaoquan He	  the entropy pool as well. If neither RDRAND nor RDTSC are
2132ed9f007eSKees Cook	  supported, then entropy is read from the i8254 timer. The
2133ed9f007eSKees Cook	  usable entropy is limited by the kernel being built using
2134ed9f007eSKees Cook	  2GB addressing, and that PHYSICAL_ALIGN must be at a
2135ed9f007eSKees Cook	  minimum of 2MB. As a result, only 10 bits of entropy are
2136ed9f007eSKees Cook	  theoretically possible, but the implementations are further
2137ed9f007eSKees Cook	  limited due to memory layouts.
2138e8581e3dSBaoquan He
21396807c846SIngo Molnar	  If unsure, say Y.
2140da2b6fb9SKees Cook
21418ab3820fSKees Cook# Relocation on x86 needs some additional build support
2142845adf72SH. Peter Anvinconfig X86_NEED_RELOCS
2143845adf72SH. Peter Anvin	def_bool y
21448ab3820fSKees Cook	depends on RANDOMIZE_BASE || (X86_32 && RELOCATABLE)
2145845adf72SH. Peter Anvin
2146506f1d07SSam Ravnborgconfig PHYSICAL_ALIGN
2147a0215061SKees Cook	hex "Alignment value to which kernel should be aligned"
21488ab3820fSKees Cook	default "0x200000"
2149a0215061SKees Cook	range 0x2000 0x1000000 if X86_32
2150a0215061SKees Cook	range 0x200000 0x1000000 if X86_64
21518f9ca475SIngo Molnar	---help---
2152506f1d07SSam Ravnborg	  This value puts the alignment restrictions on physical address
2153506f1d07SSam Ravnborg	  where kernel is loaded and run from. Kernel is compiled for an
2154506f1d07SSam Ravnborg	  address which meets above alignment restriction.
2155506f1d07SSam Ravnborg
2156506f1d07SSam Ravnborg	  If bootloader loads the kernel at a non-aligned address and
2157506f1d07SSam Ravnborg	  CONFIG_RELOCATABLE is set, kernel will move itself to nearest
2158506f1d07SSam Ravnborg	  address aligned to above value and run from there.
2159506f1d07SSam Ravnborg
2160506f1d07SSam Ravnborg	  If bootloader loads the kernel at a non-aligned address and
2161506f1d07SSam Ravnborg	  CONFIG_RELOCATABLE is not set, kernel will ignore the run time
2162506f1d07SSam Ravnborg	  load address and decompress itself to the address it has been
2163506f1d07SSam Ravnborg	  compiled for and run from there. The address for which kernel is
2164506f1d07SSam Ravnborg	  compiled already meets above alignment restrictions. Hence the
2165506f1d07SSam Ravnborg	  end result is that kernel runs from a physical address meeting
2166506f1d07SSam Ravnborg	  above alignment restrictions.
2167506f1d07SSam Ravnborg
2168a0215061SKees Cook	  On 32-bit this value must be a multiple of 0x2000. On 64-bit
2169a0215061SKees Cook	  this value must be a multiple of 0x200000.
2170a0215061SKees Cook
2171506f1d07SSam Ravnborg	  Don't change this unless you know what you are doing.
2172506f1d07SSam Ravnborg
2173eedb92abSKirill A. Shutemovconfig DYNAMIC_MEMORY_LAYOUT
2174eedb92abSKirill A. Shutemov	bool
2175eedb92abSKirill A. Shutemov	---help---
2176eedb92abSKirill A. Shutemov	  This option makes base addresses of vmalloc and vmemmap as well as
2177eedb92abSKirill A. Shutemov	  __PAGE_OFFSET movable during boot.
2178eedb92abSKirill A. Shutemov
21790483e1faSThomas Garnierconfig RANDOMIZE_MEMORY
21800483e1faSThomas Garnier	bool "Randomize the kernel memory sections"
21810483e1faSThomas Garnier	depends on X86_64
21820483e1faSThomas Garnier	depends on RANDOMIZE_BASE
2183eedb92abSKirill A. Shutemov	select DYNAMIC_MEMORY_LAYOUT
21840483e1faSThomas Garnier	default RANDOMIZE_BASE
21850483e1faSThomas Garnier	---help---
21860483e1faSThomas Garnier	   Randomizes the base virtual address of kernel memory sections
21870483e1faSThomas Garnier	   (physical memory mapping, vmalloc & vmemmap). This security feature
21880483e1faSThomas Garnier	   makes exploits relying on predictable memory locations less reliable.
21890483e1faSThomas Garnier
21900483e1faSThomas Garnier	   The order of allocations remains unchanged. Entropy is generated in
21910483e1faSThomas Garnier	   the same way as RANDOMIZE_BASE. Current implementation in the optimal
21920483e1faSThomas Garnier	   configuration have in average 30,000 different possible virtual
21930483e1faSThomas Garnier	   addresses for each memory section.
21940483e1faSThomas Garnier
21956807c846SIngo Molnar	   If unsure, say Y.
21960483e1faSThomas Garnier
219790397a41SThomas Garnierconfig RANDOMIZE_MEMORY_PHYSICAL_PADDING
219890397a41SThomas Garnier	hex "Physical memory mapping padding" if EXPERT
219990397a41SThomas Garnier	depends on RANDOMIZE_MEMORY
220090397a41SThomas Garnier	default "0xa" if MEMORY_HOTPLUG
220190397a41SThomas Garnier	default "0x0"
220290397a41SThomas Garnier	range 0x1 0x40 if MEMORY_HOTPLUG
220390397a41SThomas Garnier	range 0x0 0x40
220490397a41SThomas Garnier	---help---
220590397a41SThomas Garnier	   Define the padding in terabytes added to the existing physical
220690397a41SThomas Garnier	   memory size during kernel memory randomization. It is useful
220790397a41SThomas Garnier	   for memory hotplug support but reduces the entropy available for
220890397a41SThomas Garnier	   address randomization.
220990397a41SThomas Garnier
221090397a41SThomas Garnier	   If unsure, leave at the default value.
221190397a41SThomas Garnier
2212506f1d07SSam Ravnborgconfig HOTPLUG_CPU
22137c13e6a3SDimitri Sivanich	bool "Support for hot-pluggable CPUs"
221440b31360SStephen Rothwell	depends on SMP
2215506f1d07SSam Ravnborg	---help---
22167c13e6a3SDimitri Sivanich	  Say Y here to allow turning CPUs off and on. CPUs can be
22177c13e6a3SDimitri Sivanich	  controlled through /sys/devices/system/cpu.
22187c13e6a3SDimitri Sivanich	  ( Note: power management support will enable this option
22197c13e6a3SDimitri Sivanich	    automatically on SMP systems. )
22207c13e6a3SDimitri Sivanich	  Say N if you want to disable CPU hotplug.
2221506f1d07SSam Ravnborg
222280aa1dffSFenghua Yuconfig BOOTPARAM_HOTPLUG_CPU0
222380aa1dffSFenghua Yu	bool "Set default setting of cpu0_hotpluggable"
222480aa1dffSFenghua Yu	default n
22252c922cd0SKees Cook	depends on HOTPLUG_CPU
222680aa1dffSFenghua Yu	---help---
222780aa1dffSFenghua Yu	  Set whether default state of cpu0_hotpluggable is on or off.
222880aa1dffSFenghua Yu
222980aa1dffSFenghua Yu	  Say Y here to enable CPU0 hotplug by default. If this switch
223080aa1dffSFenghua Yu	  is turned on, there is no need to give cpu0_hotplug kernel
223180aa1dffSFenghua Yu	  parameter and the CPU0 hotplug feature is enabled by default.
223280aa1dffSFenghua Yu
223380aa1dffSFenghua Yu	  Please note: there are two known CPU0 dependencies if you want
223480aa1dffSFenghua Yu	  to enable the CPU0 hotplug feature either by this switch or by
223580aa1dffSFenghua Yu	  cpu0_hotplug kernel parameter.
223680aa1dffSFenghua Yu
223780aa1dffSFenghua Yu	  First, resume from hibernate or suspend always starts from CPU0.
223880aa1dffSFenghua Yu	  So hibernate and suspend are prevented if CPU0 is offline.
223980aa1dffSFenghua Yu
224080aa1dffSFenghua Yu	  Second dependency is PIC interrupts always go to CPU0. CPU0 can not
224180aa1dffSFenghua Yu	  offline if any interrupt can not migrate out of CPU0. There may
224280aa1dffSFenghua Yu	  be other CPU0 dependencies.
224380aa1dffSFenghua Yu
224480aa1dffSFenghua Yu	  Please make sure the dependencies are under your control before
224580aa1dffSFenghua Yu	  you enable this feature.
224680aa1dffSFenghua Yu
224780aa1dffSFenghua Yu	  Say N if you don't want to enable CPU0 hotplug feature by default.
224880aa1dffSFenghua Yu	  You still can enable the CPU0 hotplug feature at boot by kernel
224980aa1dffSFenghua Yu	  parameter cpu0_hotplug.
225080aa1dffSFenghua Yu
2251a71c8bc5SFenghua Yuconfig DEBUG_HOTPLUG_CPU0
2252a71c8bc5SFenghua Yu	def_bool n
2253a71c8bc5SFenghua Yu	prompt "Debug CPU0 hotplug"
22542c922cd0SKees Cook	depends on HOTPLUG_CPU
2255a71c8bc5SFenghua Yu	---help---
2256a71c8bc5SFenghua Yu	  Enabling this option offlines CPU0 (if CPU0 can be offlined) as
2257a71c8bc5SFenghua Yu	  soon as possible and boots up userspace with CPU0 offlined. User
2258a71c8bc5SFenghua Yu	  can online CPU0 back after boot time.
2259a71c8bc5SFenghua Yu
2260a71c8bc5SFenghua Yu	  To debug CPU0 hotplug, you need to enable CPU0 offline/online
2261a71c8bc5SFenghua Yu	  feature by either turning on CONFIG_BOOTPARAM_HOTPLUG_CPU0 during
2262a71c8bc5SFenghua Yu	  compilation or giving cpu0_hotplug kernel parameter at boot.
2263a71c8bc5SFenghua Yu
2264a71c8bc5SFenghua Yu	  If unsure, say N.
2265a71c8bc5SFenghua Yu
2266506f1d07SSam Ravnborgconfig COMPAT_VDSO
2267b0b49f26SAndy Lutomirski	def_bool n
2268b0b49f26SAndy Lutomirski	prompt "Disable the 32-bit vDSO (needed for glibc 2.3.3)"
2269953fee1dSIngo Molnar	depends on COMPAT_32
22708f9ca475SIngo Molnar	---help---
2271b0b49f26SAndy Lutomirski	  Certain buggy versions of glibc will crash if they are
2272b0b49f26SAndy Lutomirski	  presented with a 32-bit vDSO that is not mapped at the address
2273b0b49f26SAndy Lutomirski	  indicated in its segment table.
2274e84446deSRandy Dunlap
2275b0b49f26SAndy Lutomirski	  The bug was introduced by f866314b89d56845f55e6f365e18b31ec978ec3a
2276b0b49f26SAndy Lutomirski	  and fixed by 3b3ddb4f7db98ec9e912ccdf54d35df4aa30e04a and
2277b0b49f26SAndy Lutomirski	  49ad572a70b8aeb91e57483a11dd1b77e31c4468.  Glibc 2.3.3 is
2278b0b49f26SAndy Lutomirski	  the only released version with the bug, but OpenSUSE 9
2279b0b49f26SAndy Lutomirski	  contains a buggy "glibc 2.3.2".
2280506f1d07SSam Ravnborg
2281b0b49f26SAndy Lutomirski	  The symptom of the bug is that everything crashes on startup, saying:
2282b0b49f26SAndy Lutomirski	  dl_main: Assertion `(void *) ph->p_vaddr == _rtld_local._dl_sysinfo_dso' failed!
2283b0b49f26SAndy Lutomirski
2284b0b49f26SAndy Lutomirski	  Saying Y here changes the default value of the vdso32 boot
2285b0b49f26SAndy Lutomirski	  option from 1 to 0, which turns off the 32-bit vDSO entirely.
2286b0b49f26SAndy Lutomirski	  This works around the glibc bug but hurts performance.
2287b0b49f26SAndy Lutomirski
2288b0b49f26SAndy Lutomirski	  If unsure, say N: if you are compiling your own kernel, you
2289b0b49f26SAndy Lutomirski	  are unlikely to be using a buggy version of glibc.
2290506f1d07SSam Ravnborg
22913dc33bd3SKees Cookchoice
22923dc33bd3SKees Cook	prompt "vsyscall table for legacy applications"
22933dc33bd3SKees Cook	depends on X86_64
22943dc33bd3SKees Cook	default LEGACY_VSYSCALL_EMULATE
22953dc33bd3SKees Cook	help
22963dc33bd3SKees Cook	  Legacy user code that does not know how to find the vDSO expects
22973dc33bd3SKees Cook	  to be able to issue three syscalls by calling fixed addresses in
22983dc33bd3SKees Cook	  kernel space. Since this location is not randomized with ASLR,
22993dc33bd3SKees Cook	  it can be used to assist security vulnerability exploitation.
23003dc33bd3SKees Cook
23013dc33bd3SKees Cook	  This setting can be changed at boot time via the kernel command
2302076ca272SAndy Lutomirski	  line parameter vsyscall=[emulate|none].
23033dc33bd3SKees Cook
23043dc33bd3SKees Cook	  On a system with recent enough glibc (2.14 or newer) and no
23053dc33bd3SKees Cook	  static binaries, you can say None without a performance penalty
23063dc33bd3SKees Cook	  to improve security.
23073dc33bd3SKees Cook
23083dc33bd3SKees Cook	  If unsure, select "Emulate".
23093dc33bd3SKees Cook
23103dc33bd3SKees Cook	config LEGACY_VSYSCALL_EMULATE
23113dc33bd3SKees Cook		bool "Emulate"
23123dc33bd3SKees Cook		help
23133dc33bd3SKees Cook		  The kernel traps and emulates calls into the fixed
23143dc33bd3SKees Cook		  vsyscall address mapping. This makes the mapping
23153dc33bd3SKees Cook		  non-executable, but it still contains known contents,
23163dc33bd3SKees Cook		  which could be used in certain rare security vulnerability
23173dc33bd3SKees Cook		  exploits. This configuration is recommended when userspace
23183dc33bd3SKees Cook		  still uses the vsyscall area.
23193dc33bd3SKees Cook
23203dc33bd3SKees Cook	config LEGACY_VSYSCALL_NONE
23213dc33bd3SKees Cook		bool "None"
23223dc33bd3SKees Cook		help
23233dc33bd3SKees Cook		  There will be no vsyscall mapping at all. This will
23243dc33bd3SKees Cook		  eliminate any risk of ASLR bypass due to the vsyscall
23253dc33bd3SKees Cook		  fixed address mapping. Attempts to use the vsyscalls
23263dc33bd3SKees Cook		  will be reported to dmesg, so that either old or
23273dc33bd3SKees Cook		  malicious userspace programs can be identified.
23283dc33bd3SKees Cook
23293dc33bd3SKees Cookendchoice
23303dc33bd3SKees Cook
2331516cbf37STim Birdconfig CMDLINE_BOOL
2332516cbf37STim Bird	bool "Built-in kernel command line"
23338f9ca475SIngo Molnar	---help---
2334516cbf37STim Bird	  Allow for specifying boot arguments to the kernel at
2335516cbf37STim Bird	  build time.  On some systems (e.g. embedded ones), it is
2336516cbf37STim Bird	  necessary or convenient to provide some or all of the
2337516cbf37STim Bird	  kernel boot arguments with the kernel itself (that is,
2338516cbf37STim Bird	  to not rely on the boot loader to provide them.)
2339516cbf37STim Bird
2340516cbf37STim Bird	  To compile command line arguments into the kernel,
2341516cbf37STim Bird	  set this option to 'Y', then fill in the
234269711ca1SSébastien Hinderer	  boot arguments in CONFIG_CMDLINE.
2343516cbf37STim Bird
2344516cbf37STim Bird	  Systems with fully functional boot loaders (i.e. non-embedded)
2345516cbf37STim Bird	  should leave this option set to 'N'.
2346516cbf37STim Bird
2347516cbf37STim Birdconfig CMDLINE
2348516cbf37STim Bird	string "Built-in kernel command string"
2349516cbf37STim Bird	depends on CMDLINE_BOOL
2350516cbf37STim Bird	default ""
23518f9ca475SIngo Molnar	---help---
2352516cbf37STim Bird	  Enter arguments here that should be compiled into the kernel
2353516cbf37STim Bird	  image and used at boot time.  If the boot loader provides a
2354516cbf37STim Bird	  command line at boot time, it is appended to this string to
2355516cbf37STim Bird	  form the full kernel command line, when the system boots.
2356516cbf37STim Bird
2357516cbf37STim Bird	  However, you can use the CONFIG_CMDLINE_OVERRIDE option to
2358516cbf37STim Bird	  change this behavior.
2359516cbf37STim Bird
2360516cbf37STim Bird	  In most cases, the command line (whether built-in or provided
2361516cbf37STim Bird	  by the boot loader) should specify the device for the root
2362516cbf37STim Bird	  file system.
2363516cbf37STim Bird
2364516cbf37STim Birdconfig CMDLINE_OVERRIDE
2365516cbf37STim Bird	bool "Built-in command line overrides boot loader arguments"
2366516cbf37STim Bird	depends on CMDLINE_BOOL
23678f9ca475SIngo Molnar	---help---
2368516cbf37STim Bird	  Set this option to 'Y' to have the kernel ignore the boot loader
2369516cbf37STim Bird	  command line, and use ONLY the built-in command line.
2370516cbf37STim Bird
2371516cbf37STim Bird	  This is used to work around broken boot loaders.  This should
2372516cbf37STim Bird	  be set to 'N' under normal conditions.
2373516cbf37STim Bird
2374a5b9e5a2SAndy Lutomirskiconfig MODIFY_LDT_SYSCALL
2375a5b9e5a2SAndy Lutomirski	bool "Enable the LDT (local descriptor table)" if EXPERT
2376a5b9e5a2SAndy Lutomirski	default y
2377a5b9e5a2SAndy Lutomirski	---help---
2378a5b9e5a2SAndy Lutomirski	  Linux can allow user programs to install a per-process x86
2379a5b9e5a2SAndy Lutomirski	  Local Descriptor Table (LDT) using the modify_ldt(2) system
2380a5b9e5a2SAndy Lutomirski	  call.  This is required to run 16-bit or segmented code such as
2381a5b9e5a2SAndy Lutomirski	  DOSEMU or some Wine programs.  It is also used by some very old
2382a5b9e5a2SAndy Lutomirski	  threading libraries.
2383a5b9e5a2SAndy Lutomirski
2384a5b9e5a2SAndy Lutomirski	  Enabling this feature adds a small amount of overhead to
2385a5b9e5a2SAndy Lutomirski	  context switches and increases the low-level kernel attack
2386a5b9e5a2SAndy Lutomirski	  surface.  Disabling it removes the modify_ldt(2) system call.
2387a5b9e5a2SAndy Lutomirski
2388a5b9e5a2SAndy Lutomirski	  Saying 'N' here may make sense for embedded or server kernels.
2389a5b9e5a2SAndy Lutomirski
2390b700e7f0SSeth Jenningssource "kernel/livepatch/Kconfig"
2391b700e7f0SSeth Jennings
2392506f1d07SSam Ravnborgendmenu
2393506f1d07SSam Ravnborg
23943072e413SMichal Hockoconfig ARCH_HAS_ADD_PAGES
23953072e413SMichal Hocko	def_bool y
23963072e413SMichal Hocko	depends on X86_64 && ARCH_ENABLE_MEMORY_HOTPLUG
23973072e413SMichal Hocko
2398506f1d07SSam Ravnborgconfig ARCH_ENABLE_MEMORY_HOTPLUG
2399506f1d07SSam Ravnborg	def_bool y
2400506f1d07SSam Ravnborg	depends on X86_64 || (X86_32 && HIGHMEM)
2401506f1d07SSam Ravnborg
240235551053SGary Hadeconfig ARCH_ENABLE_MEMORY_HOTREMOVE
240335551053SGary Hade	def_bool y
240435551053SGary Hade	depends on MEMORY_HOTPLUG
240535551053SGary Hade
2406e534c7c5SLee Schermerhornconfig USE_PERCPU_NUMA_NODE_ID
2407645a7919STejun Heo	def_bool y
2408e534c7c5SLee Schermerhorn	depends on NUMA
2409e534c7c5SLee Schermerhorn
24109491846fSKirill A. Shutemovconfig ARCH_ENABLE_SPLIT_PMD_PTLOCK
24119491846fSKirill A. Shutemov	def_bool y
24129491846fSKirill A. Shutemov	depends on X86_64 || X86_PAE
24139491846fSKirill A. Shutemov
2414c177c81eSNaoya Horiguchiconfig ARCH_ENABLE_HUGEPAGE_MIGRATION
2415c177c81eSNaoya Horiguchi	def_bool y
2416c177c81eSNaoya Horiguchi	depends on X86_64 && HUGETLB_PAGE && MIGRATION
2417c177c81eSNaoya Horiguchi
24189c670ea3SNaoya Horiguchiconfig ARCH_ENABLE_THP_MIGRATION
24199c670ea3SNaoya Horiguchi	def_bool y
24209c670ea3SNaoya Horiguchi	depends on X86_64 && TRANSPARENT_HUGEPAGE
24219c670ea3SNaoya Horiguchi
2422da85f865SBjorn Helgaasmenu "Power management and ACPI options"
2423e279b6c1SSam Ravnborg
2424e279b6c1SSam Ravnborgconfig ARCH_HIBERNATION_HEADER
24253c2362e6SHarvey Harrison	def_bool y
2426e279b6c1SSam Ravnborg	depends on X86_64 && HIBERNATION
2427e279b6c1SSam Ravnborg
2428e279b6c1SSam Ravnborgsource "kernel/power/Kconfig"
2429e279b6c1SSam Ravnborg
2430e279b6c1SSam Ravnborgsource "drivers/acpi/Kconfig"
2431e279b6c1SSam Ravnborg
2432efafc8b2SFeng Tangsource "drivers/sfi/Kconfig"
2433efafc8b2SFeng Tang
2434a6b68076SAndi Kleenconfig X86_APM_BOOT
24356fc108a0SJan Beulich	def_bool y
2436282e5aabSPaul Bolle	depends on APM
2437a6b68076SAndi Kleen
2438e279b6c1SSam Ravnborgmenuconfig APM
2439e279b6c1SSam Ravnborg	tristate "APM (Advanced Power Management) BIOS support"
2440efefa6f6SIngo Molnar	depends on X86_32 && PM_SLEEP
2441e279b6c1SSam Ravnborg	---help---
2442e279b6c1SSam Ravnborg	  APM is a BIOS specification for saving power using several different
2443e279b6c1SSam Ravnborg	  techniques. This is mostly useful for battery powered laptops with
2444e279b6c1SSam Ravnborg	  APM compliant BIOSes. If you say Y here, the system time will be
2445e279b6c1SSam Ravnborg	  reset after a RESUME operation, the /proc/apm device will provide
2446e279b6c1SSam Ravnborg	  battery status information, and user-space programs will receive
2447e279b6c1SSam Ravnborg	  notification of APM "events" (e.g. battery status change).
2448e279b6c1SSam Ravnborg
2449e279b6c1SSam Ravnborg	  If you select "Y" here, you can disable actual use of the APM
2450e279b6c1SSam Ravnborg	  BIOS by passing the "apm=off" option to the kernel at boot time.
2451e279b6c1SSam Ravnborg
2452e279b6c1SSam Ravnborg	  Note that the APM support is almost completely disabled for
2453e279b6c1SSam Ravnborg	  machines with more than one CPU.
2454e279b6c1SSam Ravnborg
2455e279b6c1SSam Ravnborg	  In order to use APM, you will need supporting software. For location
24562dc98fd3SMichael Witten	  and more information, read <file:Documentation/power/apm-acpi.txt>
24572dc98fd3SMichael Witten	  and the Battery Powered Linux mini-HOWTO, available from
2458e279b6c1SSam Ravnborg	  <http://www.tldp.org/docs.html#howto>.
2459e279b6c1SSam Ravnborg
2460e279b6c1SSam Ravnborg	  This driver does not spin down disk drives (see the hdparm(8)
2461e279b6c1SSam Ravnborg	  manpage ("man 8 hdparm") for that), and it doesn't turn off
2462e279b6c1SSam Ravnborg	  VESA-compliant "green" monitors.
2463e279b6c1SSam Ravnborg
2464e279b6c1SSam Ravnborg	  This driver does not support the TI 4000M TravelMate and the ACER
2465e279b6c1SSam Ravnborg	  486/DX4/75 because they don't have compliant BIOSes. Many "green"
2466e279b6c1SSam Ravnborg	  desktop machines also don't have compliant BIOSes, and this driver
2467e279b6c1SSam Ravnborg	  may cause those machines to panic during the boot phase.
2468e279b6c1SSam Ravnborg
2469e279b6c1SSam Ravnborg	  Generally, if you don't have a battery in your machine, there isn't
2470e279b6c1SSam Ravnborg	  much point in using this driver and you should say N. If you get
2471e279b6c1SSam Ravnborg	  random kernel OOPSes or reboots that don't seem to be related to
2472e279b6c1SSam Ravnborg	  anything, try disabling/enabling this option (or disabling/enabling
2473e279b6c1SSam Ravnborg	  APM in your BIOS).
2474e279b6c1SSam Ravnborg
2475e279b6c1SSam Ravnborg	  Some other things you should try when experiencing seemingly random,
2476e279b6c1SSam Ravnborg	  "weird" problems:
2477e279b6c1SSam Ravnborg
2478e279b6c1SSam Ravnborg	  1) make sure that you have enough swap space and that it is
2479e279b6c1SSam Ravnborg	  enabled.
2480e279b6c1SSam Ravnborg	  2) pass the "no-hlt" option to the kernel
2481e279b6c1SSam Ravnborg	  3) switch on floating point emulation in the kernel and pass
2482e279b6c1SSam Ravnborg	  the "no387" option to the kernel
2483e279b6c1SSam Ravnborg	  4) pass the "floppy=nodma" option to the kernel
2484e279b6c1SSam Ravnborg	  5) pass the "mem=4M" option to the kernel (thereby disabling
2485e279b6c1SSam Ravnborg	  all but the first 4 MB of RAM)
2486e279b6c1SSam Ravnborg	  6) make sure that the CPU is not over clocked.
2487e279b6c1SSam Ravnborg	  7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/>
2488e279b6c1SSam Ravnborg	  8) disable the cache from your BIOS settings
2489e279b6c1SSam Ravnborg	  9) install a fan for the video card or exchange video RAM
2490e279b6c1SSam Ravnborg	  10) install a better fan for the CPU
2491e279b6c1SSam Ravnborg	  11) exchange RAM chips
2492e279b6c1SSam Ravnborg	  12) exchange the motherboard.
2493e279b6c1SSam Ravnborg
2494e279b6c1SSam Ravnborg	  To compile this driver as a module, choose M here: the
2495e279b6c1SSam Ravnborg	  module will be called apm.
2496e279b6c1SSam Ravnborg
2497e279b6c1SSam Ravnborgif APM
2498e279b6c1SSam Ravnborg
2499e279b6c1SSam Ravnborgconfig APM_IGNORE_USER_SUSPEND
2500e279b6c1SSam Ravnborg	bool "Ignore USER SUSPEND"
25018f9ca475SIngo Molnar	---help---
2502e279b6c1SSam Ravnborg	  This option will ignore USER SUSPEND requests. On machines with a
2503e279b6c1SSam Ravnborg	  compliant APM BIOS, you want to say N. However, on the NEC Versa M
2504e279b6c1SSam Ravnborg	  series notebooks, it is necessary to say Y because of a BIOS bug.
2505e279b6c1SSam Ravnborg
2506e279b6c1SSam Ravnborgconfig APM_DO_ENABLE
2507e279b6c1SSam Ravnborg	bool "Enable PM at boot time"
2508e279b6c1SSam Ravnborg	---help---
2509e279b6c1SSam Ravnborg	  Enable APM features at boot time. From page 36 of the APM BIOS
2510e279b6c1SSam Ravnborg	  specification: "When disabled, the APM BIOS does not automatically
2511e279b6c1SSam Ravnborg	  power manage devices, enter the Standby State, enter the Suspend
2512e279b6c1SSam Ravnborg	  State, or take power saving steps in response to CPU Idle calls."
2513e279b6c1SSam Ravnborg	  This driver will make CPU Idle calls when Linux is idle (unless this
2514e279b6c1SSam Ravnborg	  feature is turned off -- see "Do CPU IDLE calls", below). This
2515e279b6c1SSam Ravnborg	  should always save battery power, but more complicated APM features
2516e279b6c1SSam Ravnborg	  will be dependent on your BIOS implementation. You may need to turn
2517e279b6c1SSam Ravnborg	  this option off if your computer hangs at boot time when using APM
2518e279b6c1SSam Ravnborg	  support, or if it beeps continuously instead of suspending. Turn
2519e279b6c1SSam Ravnborg	  this off if you have a NEC UltraLite Versa 33/C or a Toshiba
2520e279b6c1SSam Ravnborg	  T400CDT. This is off by default since most machines do fine without
2521e279b6c1SSam Ravnborg	  this feature.
2522e279b6c1SSam Ravnborg
2523e279b6c1SSam Ravnborgconfig APM_CPU_IDLE
2524dd8af076SLen Brown	depends on CPU_IDLE
2525e279b6c1SSam Ravnborg	bool "Make CPU Idle calls when idle"
25268f9ca475SIngo Molnar	---help---
2527e279b6c1SSam Ravnborg	  Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop.
2528e279b6c1SSam Ravnborg	  On some machines, this can activate improved power savings, such as
2529e279b6c1SSam Ravnborg	  a slowed CPU clock rate, when the machine is idle. These idle calls
2530e279b6c1SSam Ravnborg	  are made after the idle loop has run for some length of time (e.g.,
2531e279b6c1SSam Ravnborg	  333 mS). On some machines, this will cause a hang at boot time or
2532e279b6c1SSam Ravnborg	  whenever the CPU becomes idle. (On machines with more than one CPU,
2533e279b6c1SSam Ravnborg	  this option does nothing.)
2534e279b6c1SSam Ravnborg
2535e279b6c1SSam Ravnborgconfig APM_DISPLAY_BLANK
2536e279b6c1SSam Ravnborg	bool "Enable console blanking using APM"
25378f9ca475SIngo Molnar	---help---
2538e279b6c1SSam Ravnborg	  Enable console blanking using the APM. Some laptops can use this to
2539e279b6c1SSam Ravnborg	  turn off the LCD backlight when the screen blanker of the Linux
2540e279b6c1SSam Ravnborg	  virtual console blanks the screen. Note that this is only used by
2541e279b6c1SSam Ravnborg	  the virtual console screen blanker, and won't turn off the backlight
2542e279b6c1SSam Ravnborg	  when using the X Window system. This also doesn't have anything to
2543e279b6c1SSam Ravnborg	  do with your VESA-compliant power-saving monitor. Further, this
2544e279b6c1SSam Ravnborg	  option doesn't work for all laptops -- it might not turn off your
2545e279b6c1SSam Ravnborg	  backlight at all, or it might print a lot of errors to the console,
2546e279b6c1SSam Ravnborg	  especially if you are using gpm.
2547e279b6c1SSam Ravnborg
2548e279b6c1SSam Ravnborgconfig APM_ALLOW_INTS
2549e279b6c1SSam Ravnborg	bool "Allow interrupts during APM BIOS calls"
25508f9ca475SIngo Molnar	---help---
2551e279b6c1SSam Ravnborg	  Normally we disable external interrupts while we are making calls to
2552e279b6c1SSam Ravnborg	  the APM BIOS as a measure to lessen the effects of a badly behaving
2553e279b6c1SSam Ravnborg	  BIOS implementation.  The BIOS should reenable interrupts if it
2554e279b6c1SSam Ravnborg	  needs to.  Unfortunately, some BIOSes do not -- especially those in
2555e279b6c1SSam Ravnborg	  many of the newer IBM Thinkpads.  If you experience hangs when you
2556e279b6c1SSam Ravnborg	  suspend, try setting this to Y.  Otherwise, say N.
2557e279b6c1SSam Ravnborg
2558e279b6c1SSam Ravnborgendif # APM
2559e279b6c1SSam Ravnborg
2560bb0a56ecSDave Jonessource "drivers/cpufreq/Kconfig"
2561e279b6c1SSam Ravnborg
2562e279b6c1SSam Ravnborgsource "drivers/cpuidle/Kconfig"
2563e279b6c1SSam Ravnborg
256427471fdbSAndy Henroidsource "drivers/idle/Kconfig"
256527471fdbSAndy Henroid
2566e279b6c1SSam Ravnborgendmenu
2567e279b6c1SSam Ravnborg
2568e279b6c1SSam Ravnborg
2569e279b6c1SSam Ravnborgmenu "Bus options (PCI etc.)"
2570e279b6c1SSam Ravnborg
2571e279b6c1SSam Ravnborgconfig PCI
25721ac97018SIngo Molnar	bool "PCI support"
25731c858087SAdrian Bunk	default y
25748f9ca475SIngo Molnar	---help---
2575e279b6c1SSam Ravnborg	  Find out whether you have a PCI motherboard. PCI is the name of a
2576e279b6c1SSam Ravnborg	  bus system, i.e. the way the CPU talks to the other stuff inside
2577e279b6c1SSam Ravnborg	  your box. Other bus systems are ISA, EISA, MicroChannel (MCA) or
2578e279b6c1SSam Ravnborg	  VESA. If you have PCI, say Y, otherwise N.
2579e279b6c1SSam Ravnborg
2580e279b6c1SSam Ravnborgchoice
2581e279b6c1SSam Ravnborg	prompt "PCI access mode"
2582efefa6f6SIngo Molnar	depends on X86_32 && PCI
2583e279b6c1SSam Ravnborg	default PCI_GOANY
2584e279b6c1SSam Ravnborg	---help---
2585e279b6c1SSam Ravnborg	  On PCI systems, the BIOS can be used to detect the PCI devices and
2586e279b6c1SSam Ravnborg	  determine their configuration. However, some old PCI motherboards
2587e279b6c1SSam Ravnborg	  have BIOS bugs and may crash if this is done. Also, some embedded
2588e279b6c1SSam Ravnborg	  PCI-based systems don't have any BIOS at all. Linux can also try to
2589e279b6c1SSam Ravnborg	  detect the PCI hardware directly without using the BIOS.
2590e279b6c1SSam Ravnborg
2591e279b6c1SSam Ravnborg	  With this option, you can specify how Linux should detect the
2592e279b6c1SSam Ravnborg	  PCI devices. If you choose "BIOS", the BIOS will be used,
2593e279b6c1SSam Ravnborg	  if you choose "Direct", the BIOS won't be used, and if you
2594e279b6c1SSam Ravnborg	  choose "MMConfig", then PCI Express MMCONFIG will be used.
2595e279b6c1SSam Ravnborg	  If you choose "Any", the kernel will try MMCONFIG, then the
2596e279b6c1SSam Ravnborg	  direct access method and falls back to the BIOS if that doesn't
2597e279b6c1SSam Ravnborg	  work. If unsure, go with the default, which is "Any".
2598e279b6c1SSam Ravnborg
2599e279b6c1SSam Ravnborgconfig PCI_GOBIOS
2600e279b6c1SSam Ravnborg	bool "BIOS"
2601e279b6c1SSam Ravnborg
2602e279b6c1SSam Ravnborgconfig PCI_GOMMCONFIG
2603e279b6c1SSam Ravnborg	bool "MMConfig"
2604e279b6c1SSam Ravnborg
2605e279b6c1SSam Ravnborgconfig PCI_GODIRECT
2606e279b6c1SSam Ravnborg	bool "Direct"
2607e279b6c1SSam Ravnborg
26083ef0e1f8SAndres Salomonconfig PCI_GOOLPC
260976fb6570SDaniel Drake	bool "OLPC XO-1"
26103ef0e1f8SAndres Salomon	depends on OLPC
26113ef0e1f8SAndres Salomon
26122bdd1b03SAndres Salomonconfig PCI_GOANY
26132bdd1b03SAndres Salomon	bool "Any"
26142bdd1b03SAndres Salomon
2615e279b6c1SSam Ravnborgendchoice
2616e279b6c1SSam Ravnborg
2617e279b6c1SSam Ravnborgconfig PCI_BIOS
26183c2362e6SHarvey Harrison	def_bool y
2619efefa6f6SIngo Molnar	depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY)
2620e279b6c1SSam Ravnborg
2621e279b6c1SSam Ravnborg# x86-64 doesn't support PCI BIOS access from long mode so always go direct.
2622e279b6c1SSam Ravnborgconfig PCI_DIRECT
26233c2362e6SHarvey Harrison	def_bool y
26240aba496fSShaohua Li	depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC || PCI_GOMMCONFIG))
2625e279b6c1SSam Ravnborg
2626e279b6c1SSam Ravnborgconfig PCI_MMCONFIG
2627b45c9f36SJan Kiszka	bool "Support mmconfig PCI config space access" if X86_64
2628b45c9f36SJan Kiszka	default y
26298364e1f8SJan Kiszka	depends on PCI && (ACPI || SFI || JAILHOUSE_GUEST)
2630b45c9f36SJan Kiszka	depends on X86_64 || (PCI_GOANY || PCI_GOMMCONFIG)
2631e279b6c1SSam Ravnborg
26323ef0e1f8SAndres Salomonconfig PCI_OLPC
26332bdd1b03SAndres Salomon	def_bool y
26342bdd1b03SAndres Salomon	depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY)
26353ef0e1f8SAndres Salomon
2636b5401a96SAlex Nixonconfig PCI_XEN
2637b5401a96SAlex Nixon	def_bool y
2638b5401a96SAlex Nixon	depends on PCI && XEN
2639b5401a96SAlex Nixon	select SWIOTLB_XEN
2640b5401a96SAlex Nixon
2641e279b6c1SSam Ravnborgconfig PCI_DOMAINS
26423c2362e6SHarvey Harrison	def_bool y
2643e279b6c1SSam Ravnborg	depends on PCI
2644e279b6c1SSam Ravnborg
26458364e1f8SJan Kiszkaconfig MMCONF_FAM10H
26468364e1f8SJan Kiszka	def_bool y
26478364e1f8SJan Kiszka	depends on X86_64 && PCI_MMCONFIG && ACPI
2648e279b6c1SSam Ravnborg
26493f6ea84aSIra W. Snyderconfig PCI_CNB20LE_QUIRK
26506a108a14SDavid Rientjes	bool "Read CNB20LE Host Bridge Windows" if EXPERT
26516ea30386SKees Cook	depends on PCI
26523f6ea84aSIra W. Snyder	help
26533f6ea84aSIra W. Snyder	  Read the PCI windows out of the CNB20LE host bridge. This allows
26543f6ea84aSIra W. Snyder	  PCI hotplug to work on systems with the CNB20LE chipset which do
26553f6ea84aSIra W. Snyder	  not have ACPI.
26563f6ea84aSIra W. Snyder
265764a5fed6SBjorn Helgaas	  There's no public spec for this chipset, and this functionality
265864a5fed6SBjorn Helgaas	  is known to be incomplete.
265964a5fed6SBjorn Helgaas
266064a5fed6SBjorn Helgaas	  You should say N unless you know you need this.
266164a5fed6SBjorn Helgaas
2662e279b6c1SSam Ravnborgsource "drivers/pci/Kconfig"
2663e279b6c1SSam Ravnborg
26643a495511SWilliam Breathitt Grayconfig ISA_BUS
266517a2a129SWilliam Breathitt Gray	bool "ISA bus support on modern systems" if EXPERT
26663a495511SWilliam Breathitt Gray	help
266717a2a129SWilliam Breathitt Gray	  Expose ISA bus device drivers and options available for selection and
266817a2a129SWilliam Breathitt Gray	  configuration. Enable this option if your target machine has an ISA
266917a2a129SWilliam Breathitt Gray	  bus. ISA is an older system, displaced by PCI and newer bus
267017a2a129SWilliam Breathitt Gray	  architectures -- if your target machine is modern, it probably does
267117a2a129SWilliam Breathitt Gray	  not have an ISA bus.
26723a495511SWilliam Breathitt Gray
26733a495511SWilliam Breathitt Gray	  If unsure, say N.
26743a495511SWilliam Breathitt Gray
26751c00f016SDavid Rientjes# x86_64 have no ISA slots, but can have ISA-style DMA.
2676e279b6c1SSam Ravnborgconfig ISA_DMA_API
26771c00f016SDavid Rientjes	bool "ISA-style DMA support" if (X86_64 && EXPERT)
26781c00f016SDavid Rientjes	default y
26791c00f016SDavid Rientjes	help
26801c00f016SDavid Rientjes	  Enables ISA-style DMA support for devices requiring such controllers.
26811c00f016SDavid Rientjes	  If unsure, say Y.
2682e279b6c1SSam Ravnborg
268351e68d05SLinus Torvaldsif X86_32
268451e68d05SLinus Torvalds
2685e279b6c1SSam Ravnborgconfig ISA
2686e279b6c1SSam Ravnborg	bool "ISA support"
26878f9ca475SIngo Molnar	---help---
2688e279b6c1SSam Ravnborg	  Find out whether you have ISA slots on your motherboard.  ISA is the
2689e279b6c1SSam Ravnborg	  name of a bus system, i.e. the way the CPU talks to the other stuff
2690e279b6c1SSam Ravnborg	  inside your box.  Other bus systems are PCI, EISA, MicroChannel
2691e279b6c1SSam Ravnborg	  (MCA) or VESA.  ISA is an older system, now being displaced by PCI;
2692e279b6c1SSam Ravnborg	  newer boards don't support it.  If you have ISA, say Y, otherwise N.
2693e279b6c1SSam Ravnborg
2694e279b6c1SSam Ravnborgconfig EISA
2695e279b6c1SSam Ravnborg	bool "EISA support"
2696e279b6c1SSam Ravnborg	depends on ISA
2697e279b6c1SSam Ravnborg	---help---
2698e279b6c1SSam Ravnborg	  The Extended Industry Standard Architecture (EISA) bus was
2699e279b6c1SSam Ravnborg	  developed as an open alternative to the IBM MicroChannel bus.
2700e279b6c1SSam Ravnborg
2701e279b6c1SSam Ravnborg	  The EISA bus provided some of the features of the IBM MicroChannel
2702e279b6c1SSam Ravnborg	  bus while maintaining backward compatibility with cards made for
2703e279b6c1SSam Ravnborg	  the older ISA bus.  The EISA bus saw limited use between 1988 and
2704e279b6c1SSam Ravnborg	  1995 when it was made obsolete by the PCI bus.
2705e279b6c1SSam Ravnborg
2706e279b6c1SSam Ravnborg	  Say Y here if you are building a kernel for an EISA-based machine.
2707e279b6c1SSam Ravnborg
2708e279b6c1SSam Ravnborg	  Otherwise, say N.
2709e279b6c1SSam Ravnborg
2710e279b6c1SSam Ravnborgsource "drivers/eisa/Kconfig"
2711e279b6c1SSam Ravnborg
2712e279b6c1SSam Ravnborgconfig SCx200
2713e279b6c1SSam Ravnborg	tristate "NatSemi SCx200 support"
27148f9ca475SIngo Molnar	---help---
2715e279b6c1SSam Ravnborg	  This provides basic support for National Semiconductor's
2716e279b6c1SSam Ravnborg	  (now AMD's) Geode processors.  The driver probes for the
2717e279b6c1SSam Ravnborg	  PCI-IDs of several on-chip devices, so its a good dependency
2718e279b6c1SSam Ravnborg	  for other scx200_* drivers.
2719e279b6c1SSam Ravnborg
2720e279b6c1SSam Ravnborg	  If compiled as a module, the driver is named scx200.
2721e279b6c1SSam Ravnborg
2722e279b6c1SSam Ravnborgconfig SCx200HR_TIMER
2723e279b6c1SSam Ravnborg	tristate "NatSemi SCx200 27MHz High-Resolution Timer Support"
2724592913ecSJohn Stultz	depends on SCx200
2725e279b6c1SSam Ravnborg	default y
27268f9ca475SIngo Molnar	---help---
2727e279b6c1SSam Ravnborg	  This driver provides a clocksource built upon the on-chip
2728e279b6c1SSam Ravnborg	  27MHz high-resolution timer.  Its also a workaround for
2729e279b6c1SSam Ravnborg	  NSC Geode SC-1100's buggy TSC, which loses time when the
2730e279b6c1SSam Ravnborg	  processor goes idle (as is done by the scheduler).  The
2731e279b6c1SSam Ravnborg	  other workaround is idle=poll boot option.
2732e279b6c1SSam Ravnborg
27333ef0e1f8SAndres Salomonconfig OLPC
27343ef0e1f8SAndres Salomon	bool "One Laptop Per Child support"
273554008979SThomas Gleixner	depends on !X86_PAE
27363c554946SAndres Salomon	select GPIOLIB
2737dc3119e7SThomas Gleixner	select OF
273845bb1674SDaniel Drake	select OF_PROMTREE
2739b4e51854SGrant Likely	select IRQ_DOMAIN
27408f9ca475SIngo Molnar	---help---
27413ef0e1f8SAndres Salomon	  Add support for detecting the unique features of the OLPC
27423ef0e1f8SAndres Salomon	  XO hardware.
27433ef0e1f8SAndres Salomon
2744a3128588SDaniel Drakeconfig OLPC_XO1_PM
2745a3128588SDaniel Drake	bool "OLPC XO-1 Power Management"
274697c4cb71SDaniel Drake	depends on OLPC && MFD_CS5535 && PM_SLEEP
2747a3128588SDaniel Drake	select MFD_CORE
2748bf1ebf00SDaniel Drake	---help---
274997c4cb71SDaniel Drake	  Add support for poweroff and suspend of the OLPC XO-1 laptop.
2750bf1ebf00SDaniel Drake
2751cfee9597SDaniel Drakeconfig OLPC_XO1_RTC
2752cfee9597SDaniel Drake	bool "OLPC XO-1 Real Time Clock"
2753cfee9597SDaniel Drake	depends on OLPC_XO1_PM && RTC_DRV_CMOS
2754cfee9597SDaniel Drake	---help---
2755cfee9597SDaniel Drake	  Add support for the XO-1 real time clock, which can be used as a
2756cfee9597SDaniel Drake	  programmable wakeup source.
2757cfee9597SDaniel Drake
27587feda8e9SDaniel Drakeconfig OLPC_XO1_SCI
27597feda8e9SDaniel Drake	bool "OLPC XO-1 SCI extras"
276092e830f2SArnd Bergmann	depends on OLPC && OLPC_XO1_PM && GPIO_CS5535=y
2761ed8e47feSRandy Dunlap	depends on INPUT=y
2762d8d01a63SDaniel Drake	select POWER_SUPPLY
27637feda8e9SDaniel Drake	---help---
27647feda8e9SDaniel Drake	  Add support for SCI-based features of the OLPC XO-1 laptop:
27657bc74b3dSDaniel Drake	   - EC-driven system wakeups
27667feda8e9SDaniel Drake	   - Power button
27677bc74b3dSDaniel Drake	   - Ebook switch
27682cf2baeaSDaniel Drake	   - Lid switch
2769e1040ac6SDaniel Drake	   - AC adapter status updates
2770e1040ac6SDaniel Drake	   - Battery status updates
27717feda8e9SDaniel Drake
2772a0f30f59SDaniel Drakeconfig OLPC_XO15_SCI
2773a0f30f59SDaniel Drake	bool "OLPC XO-1.5 SCI extras"
2774d8d01a63SDaniel Drake	depends on OLPC && ACPI
2775d8d01a63SDaniel Drake	select POWER_SUPPLY
2776a0f30f59SDaniel Drake	---help---
2777a0f30f59SDaniel Drake	  Add support for SCI-based features of the OLPC XO-1.5 laptop:
2778a0f30f59SDaniel Drake	   - EC-driven system wakeups
2779a0f30f59SDaniel Drake	   - AC adapter status updates
2780a0f30f59SDaniel Drake	   - Battery status updates
2781e279b6c1SSam Ravnborg
2782d4f3e350SEd Wildgooseconfig ALIX
2783d4f3e350SEd Wildgoose	bool "PCEngines ALIX System Support (LED setup)"
2784d4f3e350SEd Wildgoose	select GPIOLIB
2785d4f3e350SEd Wildgoose	---help---
2786d4f3e350SEd Wildgoose	  This option enables system support for the PCEngines ALIX.
2787d4f3e350SEd Wildgoose	  At present this just sets up LEDs for GPIO control on
2788d4f3e350SEd Wildgoose	  ALIX2/3/6 boards.  However, other system specific setup should
2789d4f3e350SEd Wildgoose	  get added here.
2790d4f3e350SEd Wildgoose
2791d4f3e350SEd Wildgoose	  Note: You must still enable the drivers for GPIO and LED support
2792d4f3e350SEd Wildgoose	  (GPIO_CS5535 & LEDS_GPIO) to actually use the LEDs
2793d4f3e350SEd Wildgoose
2794d4f3e350SEd Wildgoose	  Note: You have to set alix.force=1 for boards with Award BIOS.
2795d4f3e350SEd Wildgoose
2796da4e3302SPhilip Prindevilleconfig NET5501
2797da4e3302SPhilip Prindeville	bool "Soekris Engineering net5501 System Support (LEDS, GPIO, etc)"
2798da4e3302SPhilip Prindeville	select GPIOLIB
2799da4e3302SPhilip Prindeville	---help---
2800da4e3302SPhilip Prindeville	  This option enables system support for the Soekris Engineering net5501.
2801da4e3302SPhilip Prindeville
28023197059aSPhilip A. Prindevilleconfig GEOS
28033197059aSPhilip A. Prindeville	bool "Traverse Technologies GEOS System Support (LEDS, GPIO, etc)"
28043197059aSPhilip A. Prindeville	select GPIOLIB
28053197059aSPhilip A. Prindeville	depends on DMI
28063197059aSPhilip A. Prindeville	---help---
28073197059aSPhilip A. Prindeville	  This option enables system support for the Traverse Technologies GEOS.
28083197059aSPhilip A. Prindeville
28097d029125SVivien Didelotconfig TS5500
28107d029125SVivien Didelot	bool "Technologic Systems TS-5500 platform support"
28117d029125SVivien Didelot	depends on MELAN
28127d029125SVivien Didelot	select CHECK_SIGNATURE
28137d029125SVivien Didelot	select NEW_LEDS
28147d029125SVivien Didelot	select LEDS_CLASS
28157d029125SVivien Didelot	---help---
28167d029125SVivien Didelot	  This option enables system support for the Technologic Systems TS-5500.
28177d029125SVivien Didelot
2818e279b6c1SSam Ravnborgendif # X86_32
2819e279b6c1SSam Ravnborg
282023ac4ae8SAndreas Herrmannconfig AMD_NB
2821e279b6c1SSam Ravnborg	def_bool y
28220e152cd7SBorislav Petkov	depends on CPU_SUP_AMD && PCI
2823e279b6c1SSam Ravnborg
2824e279b6c1SSam Ravnborgsource "drivers/pcmcia/Kconfig"
2825e279b6c1SSam Ravnborg
2826388b78adSAlexandre Bounineconfig RAPIDIO
2827fdf90abcSAlexandre Bounine	tristate "RapidIO support"
2828388b78adSAlexandre Bounine	depends on PCI
2829388b78adSAlexandre Bounine	default n
2830388b78adSAlexandre Bounine	help
2831fdf90abcSAlexandre Bounine	  If enabled this option will include drivers and the core
2832388b78adSAlexandre Bounine	  infrastructure code to support RapidIO interconnect devices.
2833388b78adSAlexandre Bounine
2834388b78adSAlexandre Bouninesource "drivers/rapidio/Kconfig"
2835388b78adSAlexandre Bounine
2836e3263ab3SDavid Herrmannconfig X86_SYSFB
2837e3263ab3SDavid Herrmann	bool "Mark VGA/VBE/EFI FB as generic system framebuffer"
2838e3263ab3SDavid Herrmann	help
2839e3263ab3SDavid Herrmann	  Firmwares often provide initial graphics framebuffers so the BIOS,
2840e3263ab3SDavid Herrmann	  bootloader or kernel can show basic video-output during boot for
2841e3263ab3SDavid Herrmann	  user-guidance and debugging. Historically, x86 used the VESA BIOS
2842e3263ab3SDavid Herrmann	  Extensions and EFI-framebuffers for this, which are mostly limited
2843e3263ab3SDavid Herrmann	  to x86.
2844e3263ab3SDavid Herrmann	  This option, if enabled, marks VGA/VBE/EFI framebuffers as generic
2845e3263ab3SDavid Herrmann	  framebuffers so the new generic system-framebuffer drivers can be
2846e3263ab3SDavid Herrmann	  used on x86. If the framebuffer is not compatible with the generic
2847e3a5dc08SNikolas Nyby	  modes, it is advertised as fallback platform framebuffer so legacy
2848e3263ab3SDavid Herrmann	  drivers like efifb, vesafb and uvesafb can pick it up.
2849e3263ab3SDavid Herrmann	  If this option is not selected, all system framebuffers are always
2850e3263ab3SDavid Herrmann	  marked as fallback platform framebuffers as usual.
2851e3263ab3SDavid Herrmann
2852e3263ab3SDavid Herrmann	  Note: Legacy fbdev drivers, including vesafb, efifb, uvesafb, will
2853e3263ab3SDavid Herrmann	  not be able to pick up generic system framebuffers if this option
2854e3263ab3SDavid Herrmann	  is selected. You are highly encouraged to enable simplefb as
2855e3263ab3SDavid Herrmann	  replacement if you select this option. simplefb can correctly deal
2856e3263ab3SDavid Herrmann	  with generic system framebuffers. But you should still keep vesafb
2857e3263ab3SDavid Herrmann	  and others enabled as fallback if a system framebuffer is
2858e3263ab3SDavid Herrmann	  incompatible with simplefb.
2859e3263ab3SDavid Herrmann
2860e3263ab3SDavid Herrmann	  If unsure, say Y.
2861e3263ab3SDavid Herrmann
2862e279b6c1SSam Ravnborgendmenu
2863e279b6c1SSam Ravnborg
2864e279b6c1SSam Ravnborg
28651572497cSChristoph Hellwigmenu "Binary Emulations"
2866e279b6c1SSam Ravnborg
2867e279b6c1SSam Ravnborgconfig IA32_EMULATION
2868e279b6c1SSam Ravnborg	bool "IA32 Emulation"
2869e279b6c1SSam Ravnborg	depends on X86_64
287039f88911SIngo Molnar	select ARCH_WANT_OLD_COMPAT_IPC
2871d1603990SRandy Dunlap	select BINFMT_ELF
2872a97f52e6SRoland McGrath	select COMPAT_BINFMT_ELF
287339f88911SIngo Molnar	select COMPAT_OLD_SIGACTION
28748f9ca475SIngo Molnar	---help---
28755fd92e65SH. J. Lu	  Include code to run legacy 32-bit programs under a
28765fd92e65SH. J. Lu	  64-bit kernel. You should likely turn this on, unless you're
28775fd92e65SH. J. Lu	  100% sure that you don't have any 32-bit programs left.
2878e279b6c1SSam Ravnborg
2879e279b6c1SSam Ravnborgconfig IA32_AOUT
2880e279b6c1SSam Ravnborg	tristate "IA32 a.out support"
28816b213e1bSDavid Woodhouse	depends on IA32_EMULATION
28828f9ca475SIngo Molnar	---help---
2883e279b6c1SSam Ravnborg	  Support old a.out binaries in the 32bit emulation.
2884e279b6c1SSam Ravnborg
28850bf62763SH. Peter Anvinconfig X86_X32
28866ea30386SKees Cook	bool "x32 ABI for 64-bit mode"
28879b54050bSBrian Gerst	depends on X86_64
28885fd92e65SH. J. Lu	---help---
28895fd92e65SH. J. Lu	  Include code to run binaries for the x32 native 32-bit ABI
28905fd92e65SH. J. Lu	  for 64-bit processors.  An x32 process gets access to the
28915fd92e65SH. J. Lu	  full 64-bit register file and wide data path while leaving
28925fd92e65SH. J. Lu	  pointers at 32 bits for smaller memory footprint.
28935fd92e65SH. J. Lu
28945fd92e65SH. J. Lu	  You will need a recent binutils (2.22 or later) with
28955fd92e65SH. J. Lu	  elf32_x86_64 support enabled to compile a kernel with this
28965fd92e65SH. J. Lu	  option set.
28975fd92e65SH. J. Lu
2898953fee1dSIngo Molnarconfig COMPAT_32
2899953fee1dSIngo Molnar	def_bool y
2900953fee1dSIngo Molnar	depends on IA32_EMULATION || X86_32
2901953fee1dSIngo Molnar	select HAVE_UID16
2902953fee1dSIngo Molnar	select OLD_SIGSUSPEND3
2903953fee1dSIngo Molnar
2904e279b6c1SSam Ravnborgconfig COMPAT
29053c2362e6SHarvey Harrison	def_bool y
29060bf62763SH. Peter Anvin	depends on IA32_EMULATION || X86_X32
2907e279b6c1SSam Ravnborg
29083120e25eSJan Beulichif COMPAT
2909e279b6c1SSam Ravnborgconfig COMPAT_FOR_U64_ALIGNMENT
29103120e25eSJan Beulich	def_bool y
2911e279b6c1SSam Ravnborg
2912e279b6c1SSam Ravnborgconfig SYSVIPC_COMPAT
29133c2362e6SHarvey Harrison	def_bool y
29143120e25eSJan Beulich	depends on SYSVIPC
29153120e25eSJan Beulichendif
2916ee009e4aSDavid Howells
2917e279b6c1SSam Ravnborgendmenu
2918e279b6c1SSam Ravnborg
2919e279b6c1SSam Ravnborg
2920e5beae16SKeith Packardconfig HAVE_ATOMIC_IOMAP
2921e5beae16SKeith Packard	def_bool y
2922e5beae16SKeith Packard	depends on X86_32
2923e5beae16SKeith Packard
29244692d77fSAlessandro Rubiniconfig X86_DEV_DMA_OPS
29254692d77fSAlessandro Rubini	bool
292683125a3aSAlessandro Rubini	depends on X86_64 || STA2X11
29274692d77fSAlessandro Rubini
2928f7219a53SAlessandro Rubiniconfig X86_DMA_REMAP
2929f7219a53SAlessandro Rubini	bool
293083125a3aSAlessandro Rubini	depends on STA2X11
2931f7219a53SAlessandro Rubini
2932e585513bSKirill A. Shutemovconfig HAVE_GENERIC_GUP
2933e585513bSKirill A. Shutemov	def_bool y
2934e585513bSKirill A. Shutemov
2935e279b6c1SSam Ravnborgsource "drivers/firmware/Kconfig"
2936e279b6c1SSam Ravnborg
2937edf88417SAvi Kivitysource "arch/x86/kvm/Kconfig"
2938