xref: /linux/arch/x86/Kconfig (revision 86596f0a2833300568837f9b2970541bf42cbc42)
1b2441318SGreg Kroah-Hartman# SPDX-License-Identifier: GPL-2.0
2daa93fabSSam Ravnborg# Select 32 or 64 bit
3daa93fabSSam Ravnborgconfig 64BIT
46840999bSSam Ravnborg	bool "64-bit kernel" if ARCH = "x86"
5ffee0de4SDavid Woodhouse	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
31d94e0685SIngo Molnar	select X86_DEV_DMA_OPS
32f8781c4aSDominik Brodowski	select ARCH_HAS_SYSCALL_WRAPPER
331032c0baSSam Ravnborg
34d94e0685SIngo Molnar#
35d94e0685SIngo Molnar# Arch settings
36d94e0685SIngo Molnar#
37d94e0685SIngo Molnar# ( Note that options that are marked 'if X86_64' could in principle be
38d94e0685SIngo Molnar#   ported to 32-bit as well. )
39d94e0685SIngo Molnar#
408d5fffb9SSam Ravnborgconfig X86
413c2362e6SHarvey Harrison	def_bool y
42c763ea26SIngo Molnar	#
43c763ea26SIngo Molnar	# Note: keep this list sorted alphabetically
44c763ea26SIngo Molnar	#
456471b825SIngo Molnar	select ACPI_LEGACY_TABLES_LOOKUP	if ACPI
466e0a0ea1SGraeme Gregory	select ACPI_SYSTEM_POWER_STATES_SUPPORT	if ACPI
476471b825SIngo Molnar	select ANON_INODES
486471b825SIngo Molnar	select ARCH_CLOCKSOURCE_DATA
496471b825SIngo Molnar	select ARCH_DISCARD_MEMBLOCK
5091dda51aSAleksey Makarov	select ARCH_HAS_ACPI_TABLE_UPGRADE	if ACPI
51fa5b6ec9SLaura Abbott	select ARCH_HAS_DEBUG_VIRTUAL
5221266be9SDan Williams	select ARCH_HAS_DEVMEM_IS_ALLOWED
536471b825SIngo Molnar	select ARCH_HAS_ELF_RANDOMIZE
5472d93104SLinus Torvalds	select ARCH_HAS_FAST_MULTIPLIER
55316d097cSDave Hansen	select ARCH_HAS_FILTER_PGPROT
566974f0c4SDaniel Micay	select ARCH_HAS_FORTIFY_SOURCE
57957e3facSRiku Voipio	select ARCH_HAS_GCOV_PROFILE_ALL
585c9a8750SDmitry Vyukov	select ARCH_HAS_KCOV			if X86_64
5910bcc80eSMathieu Desnoyers	select ARCH_HAS_MEMBARRIER_SYNC_CORE
60c763ea26SIngo Molnar	select ARCH_HAS_PMEM_API		if X86_64
6139208aa7SKees Cook	select ARCH_HAS_REFCOUNT
620aed55afSDan Williams	select ARCH_HAS_UACCESS_FLUSHCACHE	if X86_64
63d2852a22SDaniel Borkmann	select ARCH_HAS_SET_MEMORY
646471b825SIngo Molnar	select ARCH_HAS_SG_CHAIN
65ad21fc4fSLaura Abbott	select ARCH_HAS_STRICT_KERNEL_RWX
66ad21fc4fSLaura Abbott	select ARCH_HAS_STRICT_MODULE_RWX
67ac1ab12aSMathieu Desnoyers	select ARCH_HAS_SYNC_CORE_BEFORE_USERMODE
68c6d30853SAndrey Ryabinin	select ARCH_HAS_UBSAN_SANITIZE_ALL
6965f7d049SOliver O'Halloran	select ARCH_HAS_ZONE_DEVICE		if X86_64
706471b825SIngo Molnar	select ARCH_HAVE_NMI_SAFE_CMPXCHG
716471b825SIngo Molnar	select ARCH_MIGHT_HAVE_ACPI_PDC		if ACPI
7277fbbc81SMark Salter	select ARCH_MIGHT_HAVE_PC_PARPORT
735e2c18c0SMark Salter	select ARCH_MIGHT_HAVE_PC_SERIO
746471b825SIngo Molnar	select ARCH_SUPPORTS_ATOMIC_RMW
756471b825SIngo Molnar	select ARCH_SUPPORTS_NUMA_BALANCING	if X86_64
766471b825SIngo Molnar	select ARCH_USE_BUILTIN_BSWAP
776471b825SIngo Molnar	select ARCH_USE_QUEUED_RWLOCKS
786471b825SIngo Molnar	select ARCH_USE_QUEUED_SPINLOCKS
79ce4a4e56SAndy Lutomirski	select ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH
80c763ea26SIngo Molnar	select ARCH_WANTS_DYNAMIC_TASK_STRUCT
8138d8b4e6SHuang Ying	select ARCH_WANTS_THP_SWAP		if X86_64
826471b825SIngo Molnar	select BUILDTIME_EXTABLE_SORT
836471b825SIngo Molnar	select CLKEVT_I8253
846471b825SIngo Molnar	select CLOCKSOURCE_VALIDATE_LAST_CYCLE
856471b825SIngo Molnar	select CLOCKSOURCE_WATCHDOG
866471b825SIngo Molnar	select DCACHE_WORD_ACCESS
87fec777c3SChristoph Hellwig	select DMA_DIRECT_OPS
8845471cd9SLinus Torvalds	select EDAC_ATOMIC_SCRUB
8945471cd9SLinus Torvalds	select EDAC_SUPPORT
906471b825SIngo Molnar	select GENERIC_CLOCKEVENTS
916471b825SIngo Molnar	select GENERIC_CLOCKEVENTS_BROADCAST	if X86_64 || (X86_32 && X86_LOCAL_APIC)
926471b825SIngo Molnar	select GENERIC_CLOCKEVENTS_MIN_ADJUST
936471b825SIngo Molnar	select GENERIC_CMOS_UPDATE
946471b825SIngo Molnar	select GENERIC_CPU_AUTOPROBE
9561dc0f55SThomas Gleixner	select GENERIC_CPU_VULNERABILITIES
966471b825SIngo Molnar	select GENERIC_EARLY_IOREMAP
976471b825SIngo Molnar	select GENERIC_FIND_FIRST_BIT
986471b825SIngo Molnar	select GENERIC_IOMAP
99c7d6c9ddSThomas Gleixner	select GENERIC_IRQ_EFFECTIVE_AFF_MASK	if SMP
1000fa115daSThomas Gleixner	select GENERIC_IRQ_MATRIX_ALLOCATOR	if X86_LOCAL_APIC
101ad7a929fSThomas Gleixner	select GENERIC_IRQ_MIGRATION		if SMP
1026471b825SIngo Molnar	select GENERIC_IRQ_PROBE
103c201c917SThomas Gleixner	select GENERIC_IRQ_RESERVATION_MODE
1046471b825SIngo Molnar	select GENERIC_IRQ_SHOW
1056471b825SIngo Molnar	select GENERIC_PENDING_IRQ		if SMP
1066471b825SIngo Molnar	select GENERIC_SMP_IDLE_THREAD
1076471b825SIngo Molnar	select GENERIC_STRNCPY_FROM_USER
1086471b825SIngo Molnar	select GENERIC_STRNLEN_USER
1096471b825SIngo Molnar	select GENERIC_TIME_VSYSCALL
1107edaeb68SThomas Gleixner	select HARDLOCKUP_CHECK_TIMESTAMP	if X86_64
1116471b825SIngo Molnar	select HAVE_ACPI_APEI			if ACPI
1126471b825SIngo Molnar	select HAVE_ACPI_APEI_NMI		if ACPI
1136471b825SIngo Molnar	select HAVE_ALIGNED_STRUCT_PAGE		if SLUB
1146471b825SIngo Molnar	select HAVE_ARCH_AUDITSYSCALL
1156471b825SIngo Molnar	select HAVE_ARCH_HUGE_VMAP		if X86_64 || X86_PAE
1166471b825SIngo Molnar	select HAVE_ARCH_JUMP_LABEL
117d17a1d97SAndrey Ryabinin	select HAVE_ARCH_KASAN			if X86_64
1186471b825SIngo Molnar	select HAVE_ARCH_KGDB
1199e08f57dSDaniel Cashman	select HAVE_ARCH_MMAP_RND_BITS		if MMU
1209e08f57dSDaniel Cashman	select HAVE_ARCH_MMAP_RND_COMPAT_BITS	if MMU && COMPAT
1211b028f78SDmitry Safonov	select HAVE_ARCH_COMPAT_MMAP_BASES	if MMU && COMPAT
1226471b825SIngo Molnar	select HAVE_ARCH_SECCOMP_FILTER
123f7d83c1cSKees Cook	select HAVE_ARCH_THREAD_STRUCT_WHITELIST
1246471b825SIngo Molnar	select HAVE_ARCH_TRACEHOOK
1256471b825SIngo Molnar	select HAVE_ARCH_TRANSPARENT_HUGEPAGE
126a00cc7d9SMatthew Wilcox	select HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD if X86_64
127e37e43a4SAndy Lutomirski	select HAVE_ARCH_VMAP_STACK		if X86_64
128c763ea26SIngo Molnar	select HAVE_ARCH_WITHIN_STACK_FRAMES
1296471b825SIngo Molnar	select HAVE_CC_STACKPROTECTOR
1306471b825SIngo Molnar	select HAVE_CMPXCHG_DOUBLE
1316471b825SIngo Molnar	select HAVE_CMPXCHG_LOCAL
1326471b825SIngo Molnar	select HAVE_CONTEXT_TRACKING		if X86_64
133c1bd55f9SJosh Triplett	select HAVE_COPY_THREAD_TLS
1346471b825SIngo Molnar	select HAVE_C_RECORDMCOUNT
1356471b825SIngo Molnar	select HAVE_DEBUG_KMEMLEAK
1366471b825SIngo Molnar	select HAVE_DEBUG_STACKOVERFLOW
1379c5a3621SAkinobu Mita	select HAVE_DMA_CONTIGUOUS
138677aa9f7SSteven Rostedt	select HAVE_DYNAMIC_FTRACE
13906aeaaeaSMasami Hiramatsu	select HAVE_DYNAMIC_FTRACE_WITH_REGS
140c763ea26SIngo Molnar	select HAVE_EBPF_JIT			if X86_64
14158340a07SJohannes Berg	select HAVE_EFFICIENT_UNALIGNED_ACCESS
1425f56a5dfSJiri Slaby	select HAVE_EXIT_THREAD
143644e0e8dSSteven Rostedt (VMware)	select HAVE_FENTRY			if X86_64 || DYNAMIC_FTRACE
1446471b825SIngo Molnar	select HAVE_FTRACE_MCOUNT_RECORD
1456471b825SIngo Molnar	select HAVE_FUNCTION_GRAPH_TRACER
1466471b825SIngo Molnar	select HAVE_FUNCTION_TRACER
1476b90bd4bSEmese Revfy	select HAVE_GCC_PLUGINS
1480067f129SK.Prasad	select HAVE_HW_BREAKPOINT
1496471b825SIngo Molnar	select HAVE_IDE
1506471b825SIngo Molnar	select HAVE_IOREMAP_PROT
1516471b825SIngo Molnar	select HAVE_IRQ_EXIT_ON_IRQ_STACK	if X86_64
1526471b825SIngo Molnar	select HAVE_IRQ_TIME_ACCOUNTING
1536471b825SIngo Molnar	select HAVE_KERNEL_BZIP2
1546471b825SIngo Molnar	select HAVE_KERNEL_GZIP
1556471b825SIngo Molnar	select HAVE_KERNEL_LZ4
1566471b825SIngo Molnar	select HAVE_KERNEL_LZMA
1576471b825SIngo Molnar	select HAVE_KERNEL_LZO
1586471b825SIngo Molnar	select HAVE_KERNEL_XZ
1596471b825SIngo Molnar	select HAVE_KPROBES
1606471b825SIngo Molnar	select HAVE_KPROBES_ON_FTRACE
161540adea3SMasami Hiramatsu	select HAVE_FUNCTION_ERROR_INJECTION
1626471b825SIngo Molnar	select HAVE_KRETPROBES
1636471b825SIngo Molnar	select HAVE_KVM
1646471b825SIngo Molnar	select HAVE_LIVEPATCH			if X86_64
1656471b825SIngo Molnar	select HAVE_MEMBLOCK
1666471b825SIngo Molnar	select HAVE_MEMBLOCK_NODE_MAP
1670102752eSFrederic Weisbecker	select HAVE_MIXED_BREAKPOINTS_REGS
168ee9f8fceSJosh Poimboeuf	select HAVE_MOD_ARCH_SPECIFIC
16942a0bb3fSPetr Mladek	select HAVE_NMI
1706471b825SIngo Molnar	select HAVE_OPROFILE
1716471b825SIngo Molnar	select HAVE_OPTPROBES
1726471b825SIngo Molnar	select HAVE_PCSPKR_PLATFORM
1736471b825SIngo Molnar	select HAVE_PERF_EVENTS
174c01d4323SFrederic Weisbecker	select HAVE_PERF_EVENTS_NMI
17592e5aae4SNicholas Piggin	select HAVE_HARDLOCKUP_DETECTOR_PERF	if PERF_EVENTS && HAVE_PERF_EVENTS_NMI
176c5e63197SJiri Olsa	select HAVE_PERF_REGS
177c5ebcedbSJiri Olsa	select HAVE_PERF_USER_STACK_DUMP
1789e52fc2bSVitaly Kuznetsov	select HAVE_RCU_TABLE_FREE
1796471b825SIngo Molnar	select HAVE_REGS_AND_STACK_ACCESS_API
18011af8474SJosh Poimboeuf	select HAVE_RELIABLE_STACKTRACE		if X86_64 && UNWINDER_FRAME_POINTER && STACK_VALIDATION
181c763ea26SIngo Molnar	select HAVE_STACK_VALIDATION		if X86_64
1826471b825SIngo Molnar	select HAVE_SYSCALL_TRACEPOINTS
1836471b825SIngo Molnar	select HAVE_UNSTABLE_SCHED_CLOCK
1847c68af6eSAvi Kivity	select HAVE_USER_RETURN_NOTIFIER
185c0185808SThomas Gleixner	select IRQ_FORCED_THREADING
186*86596f0aSChristoph Hellwig	select NEED_SG_DMA_LENGTH
187df65c1bcSThomas Gleixner	select PCI_LOCKLESS_CONFIG
1886471b825SIngo Molnar	select PERF_EVENTS
1893195ef59SPrarit Bhargava	select RTC_LIB
190d6faca40SArnd Bergmann	select RTC_MC146818_LIB
1916471b825SIngo Molnar	select SPARSE_IRQ
19283fe27eaSPranith Kumar	select SRCU
1936471b825SIngo Molnar	select SYSCTL_EXCEPTION_TRACE
19415f4eae7SAndy Lutomirski	select THREAD_INFO_IN_TASK
1956471b825SIngo Molnar	select USER_STACKTRACE_SUPPORT
1966471b825SIngo Molnar	select VIRT_TO_BUS
1976471b825SIngo Molnar	select X86_FEATURE_NAMES		if PROC_FS
1987d8330a5SBalbir Singh
199ba7e4d13SIngo Molnarconfig INSTRUCTION_DECODER
2003120e25eSJan Beulich	def_bool y
2013120e25eSJan Beulich	depends on KPROBES || PERF_EVENTS || UPROBES
202ba7e4d13SIngo Molnar
20351b26adaSLinus Torvaldsconfig OUTPUT_FORMAT
20451b26adaSLinus Torvalds	string
20551b26adaSLinus Torvalds	default "elf32-i386" if X86_32
20651b26adaSLinus Torvalds	default "elf64-x86-64" if X86_64
20751b26adaSLinus Torvalds
20873531905SSam Ravnborgconfig ARCH_DEFCONFIG
209b9b39bfbSSam Ravnborg	string
21073531905SSam Ravnborg	default "arch/x86/configs/i386_defconfig" if X86_32
21173531905SSam Ravnborg	default "arch/x86/configs/x86_64_defconfig" if X86_64
212b9b39bfbSSam Ravnborg
2138d5fffb9SSam Ravnborgconfig LOCKDEP_SUPPORT
2143c2362e6SHarvey Harrison	def_bool y
2158d5fffb9SSam Ravnborg
2168d5fffb9SSam Ravnborgconfig STACKTRACE_SUPPORT
2173c2362e6SHarvey Harrison	def_bool y
2188d5fffb9SSam Ravnborg
2198d5fffb9SSam Ravnborgconfig MMU
2203c2362e6SHarvey Harrison	def_bool y
2218d5fffb9SSam Ravnborg
2229e08f57dSDaniel Cashmanconfig ARCH_MMAP_RND_BITS_MIN
2239e08f57dSDaniel Cashman	default 28 if 64BIT
2249e08f57dSDaniel Cashman	default 8
2259e08f57dSDaniel Cashman
2269e08f57dSDaniel Cashmanconfig ARCH_MMAP_RND_BITS_MAX
2279e08f57dSDaniel Cashman	default 32 if 64BIT
2289e08f57dSDaniel Cashman	default 16
2299e08f57dSDaniel Cashman
2309e08f57dSDaniel Cashmanconfig ARCH_MMAP_RND_COMPAT_BITS_MIN
2319e08f57dSDaniel Cashman	default 8
2329e08f57dSDaniel Cashman
2339e08f57dSDaniel Cashmanconfig ARCH_MMAP_RND_COMPAT_BITS_MAX
2349e08f57dSDaniel Cashman	default 16
2359e08f57dSDaniel Cashman
2368d5fffb9SSam Ravnborgconfig SBUS
2378d5fffb9SSam Ravnborg	bool
2388d5fffb9SSam Ravnborg
2393bc4e459SFUJITA Tomonoriconfig NEED_DMA_MAP_STATE
2403120e25eSJan Beulich	def_bool y
241a6dfa128SKonrad Rzeszutek Wilk	depends on X86_64 || INTEL_IOMMU || DMA_API_DEBUG || SWIOTLB
2423bc4e459SFUJITA Tomonori
2438d5fffb9SSam Ravnborgconfig GENERIC_ISA_DMA
2443120e25eSJan Beulich	def_bool y
2453120e25eSJan Beulich	depends on ISA_DMA_API
2468d5fffb9SSam Ravnborg
2478d5fffb9SSam Ravnborgconfig GENERIC_BUG
2483c2362e6SHarvey Harrison	def_bool y
2498d5fffb9SSam Ravnborg	depends on BUG
250b93a531eSJan Beulich	select GENERIC_BUG_RELATIVE_POINTERS if X86_64
251b93a531eSJan Beulich
252b93a531eSJan Beulichconfig GENERIC_BUG_RELATIVE_POINTERS
253b93a531eSJan Beulich	bool
2548d5fffb9SSam Ravnborg
2558d5fffb9SSam Ravnborgconfig GENERIC_HWEIGHT
2563c2362e6SHarvey Harrison	def_bool y
2578d5fffb9SSam Ravnborg
2588d5fffb9SSam Ravnborgconfig ARCH_MAY_HAVE_PC_FDC
2593120e25eSJan Beulich	def_bool y
2603120e25eSJan Beulich	depends on ISA_DMA_API
2618d5fffb9SSam Ravnborg
2621032c0baSSam Ravnborgconfig RWSEM_XCHGADD_ALGORITHM
2633120e25eSJan Beulich	def_bool y
2641032c0baSSam Ravnborg
2651032c0baSSam Ravnborgconfig GENERIC_CALIBRATE_DELAY
2661032c0baSSam Ravnborg	def_bool y
2671032c0baSSam Ravnborg
2689a0b8415Svenkatesh.pallipadi@intel.comconfig ARCH_HAS_CPU_RELAX
2699a0b8415Svenkatesh.pallipadi@intel.com	def_bool y
2708d5fffb9SSam Ravnborg
2711b27d05bSPekka Enbergconfig ARCH_HAS_CACHE_LINE_SIZE
2721b27d05bSPekka Enberg	def_bool y
2731b27d05bSPekka Enberg
274316d097cSDave Hansenconfig ARCH_HAS_FILTER_PGPROT
275316d097cSDave Hansen	def_bool y
276316d097cSDave Hansen
277dd5af90aSMike Travisconfig HAVE_SETUP_PER_CPU_AREA
27889c9c4c5SBrian Gerst	def_bool y
279b32ef636Stravis@sgi.com
28008fc4580STejun Heoconfig NEED_PER_CPU_EMBED_FIRST_CHUNK
28108fc4580STejun Heo	def_bool y
28208fc4580STejun Heo
28308fc4580STejun Heoconfig NEED_PER_CPU_PAGE_FIRST_CHUNK
28411124411STejun Heo	def_bool y
28511124411STejun Heo
286801e4062SJohannes Bergconfig ARCH_HIBERNATION_POSSIBLE
287801e4062SJohannes Berg	def_bool y
288801e4062SJohannes Berg
289f4cb5700SJohannes Bergconfig ARCH_SUSPEND_POSSIBLE
290f4cb5700SJohannes Berg	def_bool y
291f4cb5700SJohannes Berg
292cfe28c5dSSteve Capperconfig ARCH_WANT_HUGE_PMD_SHARE
293cfe28c5dSSteve Capper	def_bool y
294cfe28c5dSSteve Capper
29553313b2cSSteve Capperconfig ARCH_WANT_GENERAL_HUGETLB
29653313b2cSSteve Capper	def_bool y
29753313b2cSSteve Capper
2988d5fffb9SSam Ravnborgconfig ZONE_DMA32
299e0fd24a3SJan Beulich	def_bool y if X86_64
3008d5fffb9SSam Ravnborg
3018d5fffb9SSam Ravnborgconfig AUDIT_ARCH
302e0fd24a3SJan Beulich	def_bool y if X86_64
3038d5fffb9SSam Ravnborg
304765c68bdSIngo Molnarconfig ARCH_SUPPORTS_OPTIMIZED_INLINING
305765c68bdSIngo Molnar	def_bool y
306765c68bdSIngo Molnar
3076a11f75bSAkinobu Mitaconfig ARCH_SUPPORTS_DEBUG_PAGEALLOC
3086a11f75bSAkinobu Mita	def_bool y
3096a11f75bSAkinobu Mita
310d6f2d75aSAndrey Ryabininconfig KASAN_SHADOW_OFFSET
311d6f2d75aSAndrey Ryabinin	hex
312d6f2d75aSAndrey Ryabinin	depends on KASAN
313d6f2d75aSAndrey Ryabinin	default 0xdffffc0000000000
314d6f2d75aSAndrey Ryabinin
31569575d38SShane Wangconfig HAVE_INTEL_TXT
31669575d38SShane Wang	def_bool y
3176ea30386SKees Cook	depends on INTEL_IOMMU && ACPI
31869575d38SShane Wang
3196b0c3d44SSam Ravnborgconfig X86_32_SMP
3206b0c3d44SSam Ravnborg	def_bool y
3216b0c3d44SSam Ravnborg	depends on X86_32 && SMP
3226b0c3d44SSam Ravnborg
3236b0c3d44SSam Ravnborgconfig X86_64_SMP
3246b0c3d44SSam Ravnborg	def_bool y
3256b0c3d44SSam Ravnborg	depends on X86_64 && SMP
3266b0c3d44SSam Ravnborg
327ccbeed3aSTejun Heoconfig X86_32_LAZY_GS
328ccbeed3aSTejun Heo	def_bool y
3292bc2f688SKees Cook	depends on X86_32 && CC_STACKPROTECTOR_NONE
330ccbeed3aSTejun Heo
3312b144498SSrikar Dronamrajuconfig ARCH_SUPPORTS_UPROBES
3322b144498SSrikar Dronamraju	def_bool y
3332b144498SSrikar Dronamraju
334d20642f0SRob Herringconfig FIX_EARLYCON_MEM
335d20642f0SRob Herring	def_bool y
336d20642f0SRob Herring
33798233368SKirill A. Shutemovconfig PGTABLE_LEVELS
33898233368SKirill A. Shutemov	int
33977ef56e4SKirill A. Shutemov	default 5 if X86_5LEVEL
34098233368SKirill A. Shutemov	default 4 if X86_64
34198233368SKirill A. Shutemov	default 3 if X86_PAE
34298233368SKirill A. Shutemov	default 2
34398233368SKirill A. Shutemov
344506f1d07SSam Ravnborgsource "init/Kconfig"
345dc52ddc0SMatt Helsleysource "kernel/Kconfig.freezer"
3468d5fffb9SSam Ravnborg
347506f1d07SSam Ravnborgmenu "Processor type and features"
348506f1d07SSam Ravnborg
3495ee71535SRandy Dunlapconfig ZONE_DMA
3505ee71535SRandy Dunlap	bool "DMA memory allocation support" if EXPERT
3515ee71535SRandy Dunlap	default y
3525ee71535SRandy Dunlap	help
3535ee71535SRandy Dunlap	  DMA memory allocation support allows devices with less than 32-bit
3545ee71535SRandy Dunlap	  addressing to allocate within the first 16MB of address space.
3555ee71535SRandy Dunlap	  Disable if no such devices will be used.
3565ee71535SRandy Dunlap
3575ee71535SRandy Dunlap	  If unsure, say Y.
3585ee71535SRandy Dunlap
359506f1d07SSam Ravnborgconfig SMP
360506f1d07SSam Ravnborg	bool "Symmetric multi-processing support"
361506f1d07SSam Ravnborg	---help---
362506f1d07SSam Ravnborg	  This enables support for systems with more than one CPU. If you have
3634a474157SRobert Graffham	  a system with only one CPU, say N. If you have a system with more
3644a474157SRobert Graffham	  than one CPU, say Y.
365506f1d07SSam Ravnborg
3664a474157SRobert Graffham	  If you say N here, the kernel will run on uni- and multiprocessor
367506f1d07SSam Ravnborg	  machines, but will use only one CPU of a multiprocessor machine. If
368506f1d07SSam Ravnborg	  you say Y here, the kernel will run on many, but not all,
3694a474157SRobert Graffham	  uniprocessor machines. On a uniprocessor machine, the kernel
370506f1d07SSam Ravnborg	  will run faster if you say N here.
371506f1d07SSam Ravnborg
372506f1d07SSam Ravnborg	  Note that if you say Y here and choose architecture "586" or
373506f1d07SSam Ravnborg	  "Pentium" under "Processor family", the kernel will not work on 486
374506f1d07SSam Ravnborg	  architectures. Similarly, multiprocessor kernels for the "PPro"
375506f1d07SSam Ravnborg	  architecture may not work on all Pentium based boards.
376506f1d07SSam Ravnborg
377506f1d07SSam Ravnborg	  People using multiprocessor machines who say Y here should also say
378506f1d07SSam Ravnborg	  Y to "Enhanced Real Time Clock Support", below. The "Advanced Power
379506f1d07SSam Ravnborg	  Management" code will be disabled if you say Y here.
380506f1d07SSam Ravnborg
381395cf969SPaul Bolle	  See also <file:Documentation/x86/i386/IO-APIC.txt>,
382c9525a3fSBenjamin Peterson	  <file:Documentation/lockup-watchdogs.txt> and the SMP-HOWTO available at
383506f1d07SSam Ravnborg	  <http://www.tldp.org/docs.html#howto>.
384506f1d07SSam Ravnborg
385506f1d07SSam Ravnborg	  If you don't know what to do here, say N.
386506f1d07SSam Ravnborg
3879def39beSJosh Triplettconfig X86_FEATURE_NAMES
3889def39beSJosh Triplett	bool "Processor feature human-readable names" if EMBEDDED
3899def39beSJosh Triplett	default y
3909def39beSJosh Triplett	---help---
3919def39beSJosh Triplett	  This option compiles in a table of x86 feature bits and corresponding
3929def39beSJosh Triplett	  names.  This is required to support /proc/cpuinfo and a few kernel
3939def39beSJosh Triplett	  messages.  You can disable this to save space, at the expense of
3949def39beSJosh Triplett	  making those few kernel messages show numeric feature bits instead.
3959def39beSJosh Triplett
3969def39beSJosh Triplett	  If in doubt, say Y.
3979def39beSJosh Triplett
39806cd9a7dSYinghai Luconfig X86_X2APIC
39906cd9a7dSYinghai Lu	bool "Support x2apic"
40019e3d60dSJan Kiszka	depends on X86_LOCAL_APIC && X86_64 && (IRQ_REMAP || HYPERVISOR_GUEST)
40106cd9a7dSYinghai Lu	---help---
40206cd9a7dSYinghai Lu	  This enables x2apic support on CPUs that have this feature.
40306cd9a7dSYinghai Lu
40406cd9a7dSYinghai Lu	  This allows 32-bit apic IDs (so it can support very large systems),
40506cd9a7dSYinghai Lu	  and accesses the local apic via MSRs not via mmio.
40606cd9a7dSYinghai Lu
40706cd9a7dSYinghai Lu	  If you don't know what to do here, say N.
40806cd9a7dSYinghai Lu
4096695c85bSYinghai Luconfig X86_MPPARSE
4106e87f9b7SBin Gao	bool "Enable MPS table" if ACPI || SFI
4117a527688SJan Beulich	default y
4125ab74722SIngo Molnar	depends on X86_LOCAL_APIC
4138f9ca475SIngo Molnar	---help---
4146695c85bSYinghai Lu	  For old smp systems that do not have proper acpi support. Newer systems
4156695c85bSYinghai Lu	  (esp with 64bit cpus) with acpi support, MADT and DSDT will override it
4166695c85bSYinghai Lu
417ddd70cf9SJun Nakajimaconfig GOLDFISH
418ddd70cf9SJun Nakajima       def_bool y
419ddd70cf9SJun Nakajima       depends on X86_GOLDFISH
420ddd70cf9SJun Nakajima
42176b04384SDavid Woodhouseconfig RETPOLINE
42276b04384SDavid Woodhouse	bool "Avoid speculative indirect branches in kernel"
42376b04384SDavid Woodhouse	default y
424d5028ba8SPeter Zijlstra	select STACK_VALIDATION if HAVE_STACK_VALIDATION
42576b04384SDavid Woodhouse	help
42676b04384SDavid Woodhouse	  Compile kernel with the retpoline compiler options to guard against
42776b04384SDavid Woodhouse	  kernel-to-user data leaks by avoiding speculative indirect
42876b04384SDavid Woodhouse	  branches. Requires a compiler with -mindirect-branch=thunk-extern
42976b04384SDavid Woodhouse	  support for full protection. The kernel may run slower.
43076b04384SDavid Woodhouse
43176b04384SDavid Woodhouse	  Without compiler support, at least indirect branches in assembler
43276b04384SDavid Woodhouse	  code are eliminated. Since this includes the syscall entry path,
43376b04384SDavid Woodhouse	  it is not entirely pointless.
43476b04384SDavid Woodhouse
435f01d7d51SVikas Shivappaconfig INTEL_RDT
436f01d7d51SVikas Shivappa	bool "Intel Resource Director Technology support"
43778e99b4aSFenghua Yu	default n
43878e99b4aSFenghua Yu	depends on X86 && CPU_SUP_INTEL
43959fe5a77SThomas Gleixner	select KERNFS
44078e99b4aSFenghua Yu	help
441f01d7d51SVikas Shivappa	  Select to enable resource allocation and monitoring which are
442f01d7d51SVikas Shivappa	  sub-features of Intel Resource Director Technology(RDT). More
443f01d7d51SVikas Shivappa	  information about RDT can be found in the Intel x86
444f01d7d51SVikas Shivappa	  Architecture Software Developer Manual.
44578e99b4aSFenghua Yu
44678e99b4aSFenghua Yu	  Say N if unsure.
44778e99b4aSFenghua Yu
4488425091fSRavikiran G Thirumalaiif X86_32
449a0d0bb4dSRandy Dunlapconfig X86_BIGSMP
450a0d0bb4dSRandy Dunlap	bool "Support for big SMP systems with more than 8 CPUs"
451a0d0bb4dSRandy Dunlap	depends on SMP
452a0d0bb4dSRandy Dunlap	---help---
453a0d0bb4dSRandy Dunlap	  This option is needed for the systems that have more than 8 CPUs
454a0d0bb4dSRandy Dunlap
455c5c606d9SRavikiran G Thirumalaiconfig X86_EXTENDED_PLATFORM
456c5c606d9SRavikiran G Thirumalai	bool "Support for extended (non-PC) x86 platforms"
457c5c606d9SRavikiran G Thirumalai	default y
4588f9ca475SIngo Molnar	---help---
45906ac8346SIngo Molnar	  If you disable this option then the kernel will only support
46006ac8346SIngo Molnar	  standard PC platforms. (which covers the vast majority of
46106ac8346SIngo Molnar	  systems out there.)
46206ac8346SIngo Molnar
4638425091fSRavikiran G Thirumalai	  If you enable this option then you'll be able to select support
4648425091fSRavikiran G Thirumalai	  for the following (non-PC) 32 bit x86 platforms:
465cb7b8023SBen Hutchings		Goldfish (Android emulator)
4668425091fSRavikiran G Thirumalai		AMD Elan
4678425091fSRavikiran G Thirumalai		RDC R-321x SoC
4688425091fSRavikiran G Thirumalai		SGI 320/540 (Visual Workstation)
46983125a3aSAlessandro Rubini		STA2X11-based (e.g. Northville)
4703f4110a4SThomas Gleixner		Moorestown MID devices
47106ac8346SIngo Molnar
47206ac8346SIngo Molnar	  If you have one of these systems, or if you want to build a
47306ac8346SIngo Molnar	  generic distribution kernel, say Y here - otherwise say N.
4748425091fSRavikiran G Thirumalaiendif
47506ac8346SIngo Molnar
4768425091fSRavikiran G Thirumalaiif X86_64
4778425091fSRavikiran G Thirumalaiconfig X86_EXTENDED_PLATFORM
4788425091fSRavikiran G Thirumalai	bool "Support for extended (non-PC) x86 platforms"
4798425091fSRavikiran G Thirumalai	default y
4808425091fSRavikiran G Thirumalai	---help---
4818425091fSRavikiran G Thirumalai	  If you disable this option then the kernel will only support
4828425091fSRavikiran G Thirumalai	  standard PC platforms. (which covers the vast majority of
4838425091fSRavikiran G Thirumalai	  systems out there.)
4848425091fSRavikiran G Thirumalai
4858425091fSRavikiran G Thirumalai	  If you enable this option then you'll be able to select support
4868425091fSRavikiran G Thirumalai	  for the following (non-PC) 64 bit x86 platforms:
48744b111b5SSteffen Persvold		Numascale NumaChip
4888425091fSRavikiran G Thirumalai		ScaleMP vSMP
4898425091fSRavikiran G Thirumalai		SGI Ultraviolet
4908425091fSRavikiran G Thirumalai
4918425091fSRavikiran G Thirumalai	  If you have one of these systems, or if you want to build a
4928425091fSRavikiran G Thirumalai	  generic distribution kernel, say Y here - otherwise say N.
4938425091fSRavikiran G Thirumalaiendif
494c5c606d9SRavikiran G Thirumalai# This is an alphabetically sorted list of 64 bit extended platforms
495c5c606d9SRavikiran G Thirumalai# Please maintain the alphabetic order if and when there are additions
49644b111b5SSteffen Persvoldconfig X86_NUMACHIP
49744b111b5SSteffen Persvold	bool "Numascale NumaChip"
49844b111b5SSteffen Persvold	depends on X86_64
49944b111b5SSteffen Persvold	depends on X86_EXTENDED_PLATFORM
50044b111b5SSteffen Persvold	depends on NUMA
50144b111b5SSteffen Persvold	depends on SMP
50244b111b5SSteffen Persvold	depends on X86_X2APIC
503f9726bfdSDaniel J Blueman	depends on PCI_MMCONFIG
50444b111b5SSteffen Persvold	---help---
50544b111b5SSteffen Persvold	  Adds support for Numascale NumaChip large-SMP systems. Needed to
50644b111b5SSteffen Persvold	  enable more than ~168 cores.
50744b111b5SSteffen Persvold	  If you don't have one of these, you should say N here.
50803b48632SNick Piggin
5096a48565eSIngo Molnarconfig X86_VSMP
510c5c606d9SRavikiran G Thirumalai	bool "ScaleMP vSMP"
5116276a074SBorislav Petkov	select HYPERVISOR_GUEST
5126a48565eSIngo Molnar	select PARAVIRT
5136a48565eSIngo Molnar	depends on X86_64 && PCI
514c5c606d9SRavikiran G Thirumalai	depends on X86_EXTENDED_PLATFORM
515ead91d4bSShai Fultheim	depends on SMP
5168f9ca475SIngo Molnar	---help---
5176a48565eSIngo Molnar	  Support for ScaleMP vSMP systems.  Say 'Y' here if this kernel is
5186a48565eSIngo Molnar	  supposed to run on these EM64T-based machines.  Only choose this option
5196a48565eSIngo Molnar	  if you have one of these machines.
5206a48565eSIngo Molnar
521c5c606d9SRavikiran G Thirumalaiconfig X86_UV
522c5c606d9SRavikiran G Thirumalai	bool "SGI Ultraviolet"
523c5c606d9SRavikiran G Thirumalai	depends on X86_64
524c5c606d9SRavikiran G Thirumalai	depends on X86_EXTENDED_PLATFORM
52554c28d29SJack Steiner	depends on NUMA
5261ecb4ae5SAndrew Morton	depends on EFI
5279d6c26e7SSuresh Siddha	depends on X86_X2APIC
5281222e564SIngo Molnar	depends on PCI
529c5c606d9SRavikiran G Thirumalai	---help---
530c5c606d9SRavikiran G Thirumalai	  This option is needed in order to support SGI Ultraviolet systems.
531c5c606d9SRavikiran G Thirumalai	  If you don't have one of these, you should say N here.
532c5c606d9SRavikiran G Thirumalai
533c5c606d9SRavikiran G Thirumalai# Following is an alphabetically sorted list of 32 bit extended platforms
534c5c606d9SRavikiran G Thirumalai# Please maintain the alphabetic order if and when there are additions
535506f1d07SSam Ravnborg
536ddd70cf9SJun Nakajimaconfig X86_GOLDFISH
537ddd70cf9SJun Nakajima       bool "Goldfish (Virtual Platform)"
538cb7b8023SBen Hutchings       depends on X86_EXTENDED_PLATFORM
539ddd70cf9SJun Nakajima       ---help---
540ddd70cf9SJun Nakajima	 Enable support for the Goldfish virtual platform used primarily
541ddd70cf9SJun Nakajima	 for Android development. Unless you are building for the Android
542ddd70cf9SJun Nakajima	 Goldfish emulator say N here.
543ddd70cf9SJun Nakajima
544c751e17bSThomas Gleixnerconfig X86_INTEL_CE
545c751e17bSThomas Gleixner	bool "CE4100 TV platform"
546c751e17bSThomas Gleixner	depends on PCI
547c751e17bSThomas Gleixner	depends on PCI_GODIRECT
5486084a6e2SJiang Liu	depends on X86_IO_APIC
549c751e17bSThomas Gleixner	depends on X86_32
550c751e17bSThomas Gleixner	depends on X86_EXTENDED_PLATFORM
55137bc9f50SDirk Brandewie	select X86_REBOOTFIXUPS
552da6b737bSSebastian Andrzej Siewior	select OF
553da6b737bSSebastian Andrzej Siewior	select OF_EARLY_FLATTREE
554c751e17bSThomas Gleixner	---help---
555c751e17bSThomas Gleixner	  Select for the Intel CE media processor (CE4100) SOC.
556c751e17bSThomas Gleixner	  This option compiles in support for the CE4100 SOC for settop
557c751e17bSThomas Gleixner	  boxes and media devices.
558c751e17bSThomas Gleixner
5594cb9b00fSDavid Cohenconfig X86_INTEL_MID
56043605ef1SAlan Cox	bool "Intel MID platform support"
56143605ef1SAlan Cox	depends on X86_EXTENDED_PLATFORM
562edc6bc78SDavid Cohen	depends on X86_PLATFORM_DEVICES
5631ea7c673SAlan Cox	depends on PCI
5643fda5bb4SAndy Shevchenko	depends on X86_64 || (PCI_GOANY && X86_32)
5651ea7c673SAlan Cox	depends on X86_IO_APIC
5667c9c3a1eSAlan Cox	select SFI
5674cb9b00fSDavid Cohen	select I2C
5687c9c3a1eSAlan Cox	select DW_APB_TIMER
5691ea7c673SAlan Cox	select APB_TIMER
5701ea7c673SAlan Cox	select INTEL_SCU_IPC
57115a713dfSMika Westerberg	select MFD_INTEL_MSIC
5721ea7c673SAlan Cox	---help---
5734cb9b00fSDavid Cohen	  Select to build a kernel capable of supporting Intel MID (Mobile
5744cb9b00fSDavid Cohen	  Internet Device) platform systems which do not have the PCI legacy
5754cb9b00fSDavid Cohen	  interfaces. If you are building for a PC class system say N here.
5761ea7c673SAlan Cox
5774cb9b00fSDavid Cohen	  Intel MID platforms are based on an Intel processor and chipset which
5784cb9b00fSDavid Cohen	  consume less power than most of the x86 derivatives.
57943605ef1SAlan Cox
5808bbc2a13SBryan O'Donoghueconfig X86_INTEL_QUARK
5818bbc2a13SBryan O'Donoghue	bool "Intel Quark platform support"
5828bbc2a13SBryan O'Donoghue	depends on X86_32
5838bbc2a13SBryan O'Donoghue	depends on X86_EXTENDED_PLATFORM
5848bbc2a13SBryan O'Donoghue	depends on X86_PLATFORM_DEVICES
5858bbc2a13SBryan O'Donoghue	depends on X86_TSC
5868bbc2a13SBryan O'Donoghue	depends on PCI
5878bbc2a13SBryan O'Donoghue	depends on PCI_GOANY
5888bbc2a13SBryan O'Donoghue	depends on X86_IO_APIC
5898bbc2a13SBryan O'Donoghue	select IOSF_MBI
5908bbc2a13SBryan O'Donoghue	select INTEL_IMR
5919ab6eb51SAndy Shevchenko	select COMMON_CLK
5928bbc2a13SBryan O'Donoghue	---help---
5938bbc2a13SBryan O'Donoghue	  Select to include support for Quark X1000 SoC.
5948bbc2a13SBryan O'Donoghue	  Say Y here if you have a Quark based system such as the Arduino
5958bbc2a13SBryan O'Donoghue	  compatible Intel Galileo.
5968bbc2a13SBryan O'Donoghue
5973d48aab1SMika Westerbergconfig X86_INTEL_LPSS
5983d48aab1SMika Westerberg	bool "Intel Low Power Subsystem Support"
599eebb3e8dSAndy Shevchenko	depends on X86 && ACPI
6003d48aab1SMika Westerberg	select COMMON_CLK
6010f531431SMathias Nyman	select PINCTRL
602eebb3e8dSAndy Shevchenko	select IOSF_MBI
6033d48aab1SMika Westerberg	---help---
6043d48aab1SMika Westerberg	  Select to build support for Intel Low Power Subsystem such as
6053d48aab1SMika Westerberg	  found on Intel Lynxpoint PCH. Selecting this option enables
6060f531431SMathias Nyman	  things like clock tree (common clock framework) and pincontrol
6070f531431SMathias Nyman	  which are needed by the LPSS peripheral drivers.
6083d48aab1SMika Westerberg
60992082a88SKen Xueconfig X86_AMD_PLATFORM_DEVICE
61092082a88SKen Xue	bool "AMD ACPI2Platform devices support"
61192082a88SKen Xue	depends on ACPI
61292082a88SKen Xue	select COMMON_CLK
61392082a88SKen Xue	select PINCTRL
61492082a88SKen Xue	---help---
61592082a88SKen Xue	  Select to interpret AMD specific ACPI device to platform device
61692082a88SKen Xue	  such as I2C, UART, GPIO found on AMD Carrizo and later chipsets.
61792082a88SKen Xue	  I2C and UART depend on COMMON_CLK to set clock. GPIO driver is
61892082a88SKen Xue	  implemented under PINCTRL subsystem.
61992082a88SKen Xue
620ced3ce76SDavid E. Boxconfig IOSF_MBI
621ced3ce76SDavid E. Box	tristate "Intel SoC IOSF Sideband support for SoC platforms"
622ced3ce76SDavid E. Box	depends on PCI
623ced3ce76SDavid E. Box	---help---
624ced3ce76SDavid E. Box	  This option enables sideband register access support for Intel SoC
625ced3ce76SDavid E. Box	  platforms. On these platforms the IOSF sideband is used in lieu of
626ced3ce76SDavid E. Box	  MSR's for some register accesses, mostly but not limited to thermal
627ced3ce76SDavid E. Box	  and power. Drivers may query the availability of this device to
628ced3ce76SDavid E. Box	  determine if they need the sideband in order to work on these
629ced3ce76SDavid E. Box	  platforms. The sideband is available on the following SoC products.
630ced3ce76SDavid E. Box	  This list is not meant to be exclusive.
631ced3ce76SDavid E. Box	   - BayTrail
632ced3ce76SDavid E. Box	   - Braswell
633ced3ce76SDavid E. Box	   - Quark
634ced3ce76SDavid E. Box
635ced3ce76SDavid E. Box	  You should say Y if you are running a kernel on one of these SoC's.
636ced3ce76SDavid E. Box
637ed2226bdSDavid E. Boxconfig IOSF_MBI_DEBUG
638ed2226bdSDavid E. Box	bool "Enable IOSF sideband access through debugfs"
639ed2226bdSDavid E. Box	depends on IOSF_MBI && DEBUG_FS
640ed2226bdSDavid E. Box	---help---
641ed2226bdSDavid E. Box	  Select this option to expose the IOSF sideband access registers (MCR,
642ed2226bdSDavid E. Box	  MDR, MCRX) through debugfs to write and read register information from
643ed2226bdSDavid E. Box	  different units on the SoC. This is most useful for obtaining device
644ed2226bdSDavid E. Box	  state information for debug and analysis. As this is a general access
645ed2226bdSDavid E. Box	  mechanism, users of this option would have specific knowledge of the
646ed2226bdSDavid E. Box	  device they want to access.
647ed2226bdSDavid E. Box
648ed2226bdSDavid E. Box	  If you don't require the option or are in doubt, say N.
649ed2226bdSDavid E. Box
650c5c606d9SRavikiran G Thirumalaiconfig X86_RDC321X
651c5c606d9SRavikiran G Thirumalai	bool "RDC R-321x SoC"
652506f1d07SSam Ravnborg	depends on X86_32
653c5c606d9SRavikiran G Thirumalai	depends on X86_EXTENDED_PLATFORM
654c5c606d9SRavikiran G Thirumalai	select M486
655c5c606d9SRavikiran G Thirumalai	select X86_REBOOTFIXUPS
656c5c606d9SRavikiran G Thirumalai	---help---
657c5c606d9SRavikiran G Thirumalai	  This option is needed for RDC R-321x system-on-chip, also known
658c5c606d9SRavikiran G Thirumalai	  as R-8610-(G).
659c5c606d9SRavikiran G Thirumalai	  If you don't have one of these chips, you should say N here.
660c5c606d9SRavikiran G Thirumalai
661e0c7ae37SIngo Molnarconfig X86_32_NON_STANDARD
6629c398017SIngo Molnar	bool "Support non-standard 32-bit SMP architectures"
6639c398017SIngo Molnar	depends on X86_32 && SMP
664c5c606d9SRavikiran G Thirumalai	depends on X86_EXTENDED_PLATFORM
6658f9ca475SIngo Molnar	---help---
666b5660ba7SH. Peter Anvin	  This option compiles in the bigsmp and STA2X11 default
667b5660ba7SH. Peter Anvin	  subarchitectures.  It is intended for a generic binary
668b5660ba7SH. Peter Anvin	  kernel. If you select them all, kernel will probe it one by
669b5660ba7SH. Peter Anvin	  one and will fallback to default.
670d49c4288SYinghai Lu
671c5c606d9SRavikiran G Thirumalai# Alphabetically sorted list of Non standard 32 bit platforms
672d49c4288SYinghai Lu
673d949f36fSLinus Torvaldsconfig X86_SUPPORTS_MEMORY_FAILURE
6746fc108a0SJan Beulich	def_bool y
675d949f36fSLinus Torvalds	# MCE code calls memory_failure():
676d949f36fSLinus Torvalds	depends on X86_MCE
677d949f36fSLinus Torvalds	# On 32-bit this adds too big of NODES_SHIFT and we run out of page flags:
678d949f36fSLinus Torvalds	# On 32-bit SPARSEMEM adds too big of SECTIONS_WIDTH:
679d949f36fSLinus Torvalds	depends on X86_64 || !SPARSEMEM
680d949f36fSLinus Torvalds	select ARCH_SUPPORTS_MEMORY_FAILURE
681d949f36fSLinus Torvalds
68283125a3aSAlessandro Rubiniconfig STA2X11
68383125a3aSAlessandro Rubini	bool "STA2X11 Companion Chip Support"
68483125a3aSAlessandro Rubini	depends on X86_32_NON_STANDARD && PCI
685b6e05477SChristoph Hellwig	select ARCH_HAS_PHYS_TO_DMA
68683125a3aSAlessandro Rubini	select X86_DEV_DMA_OPS
68783125a3aSAlessandro Rubini	select X86_DMA_REMAP
68883125a3aSAlessandro Rubini	select SWIOTLB
68983125a3aSAlessandro Rubini	select MFD_STA2X11
6900145071bSLinus Walleij	select GPIOLIB
69183125a3aSAlessandro Rubini	default n
69283125a3aSAlessandro Rubini	---help---
69383125a3aSAlessandro Rubini	  This adds support for boards based on the STA2X11 IO-Hub,
69483125a3aSAlessandro Rubini	  a.k.a. "ConneXt". The chip is used in place of the standard
69583125a3aSAlessandro Rubini	  PC chipset, so all "standard" peripherals are missing. If this
69683125a3aSAlessandro Rubini	  option is selected the kernel will still be able to boot on
69783125a3aSAlessandro Rubini	  standard PC machines.
69883125a3aSAlessandro Rubini
69982148d1dSShérabconfig X86_32_IRIS
70082148d1dSShérab	tristate "Eurobraille/Iris poweroff module"
70182148d1dSShérab	depends on X86_32
70282148d1dSShérab	---help---
70382148d1dSShérab	  The Iris machines from EuroBraille do not have APM or ACPI support
70482148d1dSShérab	  to shut themselves down properly.  A special I/O sequence is
70582148d1dSShérab	  needed to do so, which is what this module does at
70682148d1dSShérab	  kernel shutdown.
70782148d1dSShérab
70882148d1dSShérab	  This is only for Iris machines from EuroBraille.
70982148d1dSShérab
71082148d1dSShérab	  If unused, say N.
71182148d1dSShérab
712ae1e9130SIngo Molnarconfig SCHED_OMIT_FRAME_POINTER
7133c2362e6SHarvey Harrison	def_bool y
7143c2362e6SHarvey Harrison	prompt "Single-depth WCHAN output"
715a87d0914SKen Chen	depends on X86
7168f9ca475SIngo Molnar	---help---
717506f1d07SSam Ravnborg	  Calculate simpler /proc/<PID>/wchan values. If this option
718506f1d07SSam Ravnborg	  is disabled then wchan values will recurse back to the
719506f1d07SSam Ravnborg	  caller function. This provides more accurate wchan values,
720506f1d07SSam Ravnborg	  at the expense of slightly more scheduling overhead.
721506f1d07SSam Ravnborg
722506f1d07SSam Ravnborg	  If in doubt, say "Y".
723506f1d07SSam Ravnborg
7246276a074SBorislav Petkovmenuconfig HYPERVISOR_GUEST
7256276a074SBorislav Petkov	bool "Linux guest support"
7268f9ca475SIngo Molnar	---help---
7276276a074SBorislav Petkov	  Say Y here to enable options for running Linux under various hyper-
7286276a074SBorislav Petkov	  visors. This option enables basic hypervisor detection and platform
7296276a074SBorislav Petkov	  setup.
730506f1d07SSam Ravnborg
7316276a074SBorislav Petkov	  If you say N, all options in this submenu will be skipped and
7326276a074SBorislav Petkov	  disabled, and Linux guest support won't be built in.
733506f1d07SSam Ravnborg
7346276a074SBorislav Petkovif HYPERVISOR_GUEST
735506f1d07SSam Ravnborg
736e61bd94aSEduardo Pereira Habkostconfig PARAVIRT
737e61bd94aSEduardo Pereira Habkost	bool "Enable paravirtualization code"
7388f9ca475SIngo Molnar	---help---
739e61bd94aSEduardo Pereira Habkost	  This changes the kernel so it can modify itself when it is run
740e61bd94aSEduardo Pereira Habkost	  under a hypervisor, potentially improving performance significantly
741e61bd94aSEduardo Pereira Habkost	  over full virtualization.  However, when run without a hypervisor
742e61bd94aSEduardo Pereira Habkost	  the kernel is theoretically slower and slightly larger.
743e61bd94aSEduardo Pereira Habkost
7446276a074SBorislav Petkovconfig PARAVIRT_DEBUG
7456276a074SBorislav Petkov	bool "paravirt-ops debugging"
7466276a074SBorislav Petkov	depends on PARAVIRT && DEBUG_KERNEL
7476276a074SBorislav Petkov	---help---
7486276a074SBorislav Petkov	  Enable to debug paravirt_ops internals.  Specifically, BUG if
7496276a074SBorislav Petkov	  a paravirt_op is missing when it is called.
7506276a074SBorislav Petkov
751b4ecc126SJeremy Fitzhardingeconfig PARAVIRT_SPINLOCKS
752b4ecc126SJeremy Fitzhardinge	bool "Paravirtualization layer for spinlocks"
7536ea30386SKees Cook	depends on PARAVIRT && SMP
754b4ecc126SJeremy Fitzhardinge	---help---
755b4ecc126SJeremy Fitzhardinge	  Paravirtualized spinlocks allow a pvops backend to replace the
756b4ecc126SJeremy Fitzhardinge	  spinlock implementation with something virtualization-friendly
757b4ecc126SJeremy Fitzhardinge	  (for example, block the virtual CPU rather than spinning).
758b4ecc126SJeremy Fitzhardinge
7594c4e4f61SRaghavendra K T	  It has a minimal impact on native kernels and gives a nice performance
7604c4e4f61SRaghavendra K T	  benefit on paravirtualized KVM / Xen kernels.
761b4ecc126SJeremy Fitzhardinge
7624c4e4f61SRaghavendra K T	  If you are unsure how to answer this question, answer Y.
763b4ecc126SJeremy Fitzhardinge
76445e898b7SWaiman Longconfig QUEUED_LOCK_STAT
76545e898b7SWaiman Long	bool "Paravirt queued spinlock statistics"
766cfd8983fSPeter Zijlstra	depends on PARAVIRT_SPINLOCKS && DEBUG_FS
76745e898b7SWaiman Long	---help---
76845e898b7SWaiman Long	  Enable the collection of statistical data on the slowpath
76945e898b7SWaiman Long	  behavior of paravirtualized queued spinlocks and report
77045e898b7SWaiman Long	  them on debugfs.
77145e898b7SWaiman Long
7726276a074SBorislav Petkovsource "arch/x86/xen/Kconfig"
7736276a074SBorislav Petkov
7746276a074SBorislav Petkovconfig KVM_GUEST
7756276a074SBorislav Petkov	bool "KVM Guest support (including kvmclock)"
7766276a074SBorislav Petkov	depends on PARAVIRT
7776276a074SBorislav Petkov	select PARAVIRT_CLOCK
7786276a074SBorislav Petkov	default y
7796276a074SBorislav Petkov	---help---
7806276a074SBorislav Petkov	  This option enables various optimizations for running under the KVM
7816276a074SBorislav Petkov	  hypervisor. It includes a paravirtualized clock, so that instead
7826276a074SBorislav Petkov	  of relying on a PIT (or probably other) emulation by the
7836276a074SBorislav Petkov	  underlying device model, the host provides the guest with
7846276a074SBorislav Petkov	  timing infrastructure such as time of day, and system time
7856276a074SBorislav Petkov
7861e20eb85SSrivatsa Vaddagiriconfig KVM_DEBUG_FS
7871e20eb85SSrivatsa Vaddagiri	bool "Enable debug information for KVM Guests in debugfs"
7881e20eb85SSrivatsa Vaddagiri	depends on KVM_GUEST && DEBUG_FS
7891e20eb85SSrivatsa Vaddagiri	default n
7901e20eb85SSrivatsa Vaddagiri	---help---
7911e20eb85SSrivatsa Vaddagiri	  This option enables collection of various statistics for KVM guest.
7921e20eb85SSrivatsa Vaddagiri	  Statistics are displayed in debugfs filesystem. Enabling this option
7931e20eb85SSrivatsa Vaddagiri	  may incur significant overhead.
7941e20eb85SSrivatsa Vaddagiri
7956276a074SBorislav Petkovconfig PARAVIRT_TIME_ACCOUNTING
7966276a074SBorislav Petkov	bool "Paravirtual steal time accounting"
7976276a074SBorislav Petkov	depends on PARAVIRT
7986276a074SBorislav Petkov	default n
7996276a074SBorislav Petkov	---help---
8006276a074SBorislav Petkov	  Select this option to enable fine granularity task steal time
8016276a074SBorislav Petkov	  accounting. Time spent executing other tasks in parallel with
8026276a074SBorislav Petkov	  the current vCPU is discounted from the vCPU power. To account for
8036276a074SBorislav Petkov	  that, there can be a small performance impact.
8046276a074SBorislav Petkov
8056276a074SBorislav Petkov	  If in doubt, say N here.
8066276a074SBorislav Petkov
8077af192c9SGerd Hoffmannconfig PARAVIRT_CLOCK
8087af192c9SGerd Hoffmann	bool
8097af192c9SGerd Hoffmann
8104a362601SJan Kiszkaconfig JAILHOUSE_GUEST
8114a362601SJan Kiszka	bool "Jailhouse non-root cell support"
812abde587bSArnd Bergmann	depends on X86_64 && PCI
81387e65d05SJan Kiszka	select X86_PM_TIMER
8144a362601SJan Kiszka	---help---
8154a362601SJan Kiszka	  This option allows to run Linux as guest in a Jailhouse non-root
8164a362601SJan Kiszka	  cell. You can leave this option disabled if you only want to start
8174a362601SJan Kiszka	  Jailhouse and run Linux afterwards in the root cell.
8184a362601SJan Kiszka
8196276a074SBorislav Petkovendif #HYPERVISOR_GUEST
82097349135SJeremy Fitzhardinge
82108677214SYinghai Luconfig NO_BOOTMEM
822774ea0bcSYinghai Lu	def_bool y
82308677214SYinghai Lu
824506f1d07SSam Ravnborgsource "arch/x86/Kconfig.cpu"
825506f1d07SSam Ravnborg
826506f1d07SSam Ravnborgconfig HPET_TIMER
8273c2362e6SHarvey Harrison	def_bool X86_64
828506f1d07SSam Ravnborg	prompt "HPET Timer Support" if X86_32
8298f9ca475SIngo Molnar	---help---
830506f1d07SSam Ravnborg	  Use the IA-PC HPET (High Precision Event Timer) to manage
831506f1d07SSam Ravnborg	  time in preference to the PIT and RTC, if a HPET is
832506f1d07SSam Ravnborg	  present.
833506f1d07SSam Ravnborg	  HPET is the next generation timer replacing legacy 8254s.
834506f1d07SSam Ravnborg	  The HPET provides a stable time base on SMP
835506f1d07SSam Ravnborg	  systems, unlike the TSC, but it is more expensive to access,
8364e7f9df2SMichael S. Tsirkin	  as it is off-chip.  The interface used is documented
8374e7f9df2SMichael S. Tsirkin	  in the HPET spec, revision 1.
838506f1d07SSam Ravnborg
839506f1d07SSam Ravnborg	  You can safely choose Y here.  However, HPET will only be
840506f1d07SSam Ravnborg	  activated if the platform and the BIOS support this feature.
841506f1d07SSam Ravnborg	  Otherwise the 8254 will be used for timing services.
842506f1d07SSam Ravnborg
843506f1d07SSam Ravnborg	  Choose N to continue using the legacy 8254 timer.
844506f1d07SSam Ravnborg
845506f1d07SSam Ravnborgconfig HPET_EMULATE_RTC
8463c2362e6SHarvey Harrison	def_bool y
8479d8af78bSBernhard Walle	depends on HPET_TIMER && (RTC=y || RTC=m || RTC_DRV_CMOS=m || RTC_DRV_CMOS=y)
848506f1d07SSam Ravnborg
849bb24c471SJacob Panconfig APB_TIMER
850933b9463SAlan Cox       def_bool y if X86_INTEL_MID
851933b9463SAlan Cox       prompt "Intel MID APB Timer Support" if X86_INTEL_MID
85206c3df49SJamie Iles       select DW_APB_TIMER
853a0c3832aSAlan Cox       depends on X86_INTEL_MID && SFI
854bb24c471SJacob Pan       help
855bb24c471SJacob Pan         APB timer is the replacement for 8254, HPET on X86 MID platforms.
856bb24c471SJacob Pan         The APBT provides a stable time base on SMP
857bb24c471SJacob Pan         systems, unlike the TSC, but it is more expensive to access,
858bb24c471SJacob Pan         as it is off-chip. APB timers are always running regardless of CPU
859bb24c471SJacob Pan         C states, they are used as per CPU clockevent device when possible.
860bb24c471SJacob Pan
8616a108a14SDavid Rientjes# Mark as expert because too many people got it wrong.
862506f1d07SSam Ravnborg# The code disables itself when not needed.
8637ae9392cSThomas Petazzoniconfig DMI
8647ae9392cSThomas Petazzoni	default y
865cf074402SArd Biesheuvel	select DMI_SCAN_MACHINE_NON_EFI_FALLBACK
8666a108a14SDavid Rientjes	bool "Enable DMI scanning" if EXPERT
8678f9ca475SIngo Molnar	---help---
8687ae9392cSThomas Petazzoni	  Enabled scanning of DMI to identify machine quirks. Say Y
8697ae9392cSThomas Petazzoni	  here unless you have verified that your setup is not
8707ae9392cSThomas Petazzoni	  affected by entries in the DMI blacklist. Required by PNP
8717ae9392cSThomas Petazzoni	  BIOS code.
8727ae9392cSThomas Petazzoni
873506f1d07SSam Ravnborgconfig GART_IOMMU
87438901f1cSAndi Kleen	bool "Old AMD GART IOMMU support"
875a4ce5a48SChristoph Hellwig	select IOMMU_HELPER
876506f1d07SSam Ravnborg	select SWIOTLB
87723ac4ae8SAndreas Herrmann	depends on X86_64 && PCI && AMD_NB
8788f9ca475SIngo Molnar	---help---
879ced3c42cSIngo Molnar	  Provides a driver for older AMD Athlon64/Opteron/Turion/Sempron
880ced3c42cSIngo Molnar	  GART based hardware IOMMUs.
881ced3c42cSIngo Molnar
882ced3c42cSIngo Molnar	  The GART supports full DMA access for devices with 32-bit access
883ced3c42cSIngo Molnar	  limitations, on systems with more than 3 GB. This is usually needed
884ced3c42cSIngo Molnar	  for USB, sound, many IDE/SATA chipsets and some other devices.
885ced3c42cSIngo Molnar
886ced3c42cSIngo Molnar	  Newer systems typically have a modern AMD IOMMU, supported via
887ced3c42cSIngo Molnar	  the CONFIG_AMD_IOMMU=y config option.
888ced3c42cSIngo Molnar
889ced3c42cSIngo Molnar	  In normal configurations this driver is only active when needed:
890ced3c42cSIngo Molnar	  there's more than 3 GB of memory and the system contains a
891ced3c42cSIngo Molnar	  32-bit limited device.
892ced3c42cSIngo Molnar
893ced3c42cSIngo Molnar	  If unsure, say Y.
894506f1d07SSam Ravnborg
895506f1d07SSam Ravnborgconfig CALGARY_IOMMU
896506f1d07SSam Ravnborg	bool "IBM Calgary IOMMU support"
897a4ce5a48SChristoph Hellwig	select IOMMU_HELPER
898506f1d07SSam Ravnborg	select SWIOTLB
8996ea30386SKees Cook	depends on X86_64 && PCI
9008f9ca475SIngo Molnar	---help---
901506f1d07SSam Ravnborg	  Support for hardware IOMMUs in IBM's xSeries x366 and x460
902506f1d07SSam Ravnborg	  systems. Needed to run systems with more than 3GB of memory
903506f1d07SSam Ravnborg	  properly with 32-bit PCI devices that do not support DAC
904506f1d07SSam Ravnborg	  (Double Address Cycle). Calgary also supports bus level
905506f1d07SSam Ravnborg	  isolation, where all DMAs pass through the IOMMU.  This
906506f1d07SSam Ravnborg	  prevents them from going anywhere except their intended
907506f1d07SSam Ravnborg	  destination. This catches hard-to-find kernel bugs and
908506f1d07SSam Ravnborg	  mis-behaving drivers and devices that do not use the DMA-API
909506f1d07SSam Ravnborg	  properly to set up their DMA buffers.  The IOMMU can be
910506f1d07SSam Ravnborg	  turned off at boot time with the iommu=off parameter.
911506f1d07SSam Ravnborg	  Normally the kernel will make the right choice by itself.
912506f1d07SSam Ravnborg	  If unsure, say Y.
913506f1d07SSam Ravnborg
914506f1d07SSam Ravnborgconfig CALGARY_IOMMU_ENABLED_BY_DEFAULT
9153c2362e6SHarvey Harrison	def_bool y
9163c2362e6SHarvey Harrison	prompt "Should Calgary be enabled by default?"
917506f1d07SSam Ravnborg	depends on CALGARY_IOMMU
9188f9ca475SIngo Molnar	---help---
919506f1d07SSam Ravnborg	  Should Calgary be enabled by default? if you choose 'y', Calgary
920506f1d07SSam Ravnborg	  will be used (if it exists). If you choose 'n', Calgary will not be
921506f1d07SSam Ravnborg	  used even if it exists. If you choose 'n' and would like to use
922506f1d07SSam Ravnborg	  Calgary anyway, pass 'iommu=calgary' on the kernel command line.
923506f1d07SSam Ravnborg	  If unsure, say Y.
924506f1d07SSam Ravnborg
925506f1d07SSam Ravnborg# need this always selected by IOMMU for the VIA workaround
926506f1d07SSam Ravnborgconfig SWIOTLB
927a1afd01cSJoerg Roedel	def_bool y if X86_64
9288f9ca475SIngo Molnar	---help---
929506f1d07SSam Ravnborg	  Support for software bounce buffers used on x86-64 systems
9304454d327SJoe Millenbach	  which don't have a hardware IOMMU. Using this PCI devices
9314454d327SJoe Millenbach	  which can only access 32-bits of memory can be used on systems
9324454d327SJoe Millenbach	  with more than 3 GB of memory.
9334454d327SJoe Millenbach	  If unsure, say Y.
934506f1d07SSam Ravnborg
9351184dc2fSMike Travisconfig MAXSMP
936ddb0c5a6SSamuel Thibault	bool "Enable Maximum number of SMP Processors and NUMA Nodes"
9376ea30386SKees Cook	depends on X86_64 && SMP && DEBUG_KERNEL
93836f5101aSMike Travis	select CPUMASK_OFFSTACK
9398f9ca475SIngo Molnar	---help---
940ddb0c5a6SSamuel Thibault	  Enable maximum number of CPUS and NUMA Nodes for this architecture.
9411184dc2fSMike Travis	  If unsure, say N.
942506f1d07SSam Ravnborg
943aec6487eSIngo Molnar#
944aec6487eSIngo Molnar# The maximum number of CPUs supported:
945aec6487eSIngo Molnar#
946aec6487eSIngo Molnar# The main config value is NR_CPUS, which defaults to NR_CPUS_DEFAULT,
947aec6487eSIngo Molnar# and which can be configured interactively in the
948aec6487eSIngo Molnar# [NR_CPUS_RANGE_BEGIN ... NR_CPUS_RANGE_END] range.
949aec6487eSIngo Molnar#
950aec6487eSIngo Molnar# The ranges are different on 32-bit and 64-bit kernels, depending on
951aec6487eSIngo Molnar# hardware capabilities and scalability features of the kernel.
952aec6487eSIngo Molnar#
953aec6487eSIngo Molnar# ( If MAXSMP is enabled we just use the highest possible value and disable
954aec6487eSIngo Molnar#   interactive configuration. )
955aec6487eSIngo Molnar#
956a0d0bb4dSRandy Dunlap
957aec6487eSIngo Molnarconfig NR_CPUS_RANGE_BEGIN
958a0d0bb4dSRandy Dunlap	int
959aec6487eSIngo Molnar	default NR_CPUS_RANGE_END if MAXSMP
960a0d0bb4dSRandy Dunlap	default    1 if !SMP
961a0d0bb4dSRandy Dunlap	default    2
962a0d0bb4dSRandy Dunlap
963aec6487eSIngo Molnarconfig NR_CPUS_RANGE_END
964a0d0bb4dSRandy Dunlap	int
965a0d0bb4dSRandy Dunlap	depends on X86_32
966aec6487eSIngo Molnar	default   64 if  SMP &&  X86_BIGSMP
967aec6487eSIngo Molnar	default    8 if  SMP && !X86_BIGSMP
968a0d0bb4dSRandy Dunlap	default    1 if !SMP
969a0d0bb4dSRandy Dunlap
970aec6487eSIngo Molnarconfig NR_CPUS_RANGE_END
971a0d0bb4dSRandy Dunlap	int
972a0d0bb4dSRandy Dunlap	depends on X86_64
973aec6487eSIngo Molnar	default 8192 if  SMP && ( MAXSMP ||  CPUMASK_OFFSTACK)
974aec6487eSIngo Molnar	default  512 if  SMP && (!MAXSMP && !CPUMASK_OFFSTACK)
975a0d0bb4dSRandy Dunlap	default    1 if !SMP
976aec6487eSIngo Molnar
977aec6487eSIngo Molnarconfig NR_CPUS_DEFAULT
978aec6487eSIngo Molnar	int
979aec6487eSIngo Molnar	depends on X86_32
980aec6487eSIngo Molnar	default   32 if  X86_BIGSMP
981aec6487eSIngo Molnar	default    8 if  SMP
982aec6487eSIngo Molnar	default    1 if !SMP
983aec6487eSIngo Molnar
984aec6487eSIngo Molnarconfig NR_CPUS_DEFAULT
985aec6487eSIngo Molnar	int
986aec6487eSIngo Molnar	depends on X86_64
987a0d0bb4dSRandy Dunlap	default 8192 if  MAXSMP
988a0d0bb4dSRandy Dunlap	default   64 if  SMP
989aec6487eSIngo Molnar	default    1 if !SMP
990a0d0bb4dSRandy Dunlap
991506f1d07SSam Ravnborgconfig NR_CPUS
99236f5101aSMike Travis	int "Maximum number of CPUs" if SMP && !MAXSMP
993aec6487eSIngo Molnar	range NR_CPUS_RANGE_BEGIN NR_CPUS_RANGE_END
994aec6487eSIngo Molnar	default NR_CPUS_DEFAULT
9958f9ca475SIngo Molnar	---help---
996506f1d07SSam Ravnborg	  This allows you to specify the maximum number of CPUs which this
997bb61ccc7SJosh Boyer	  kernel will support.  If CPUMASK_OFFSTACK is enabled, the maximum
998cad14bb9SKirill A. Shutemov	  supported value is 8192, otherwise the maximum value is 512.  The
999506f1d07SSam Ravnborg	  minimum value which makes sense is 2.
1000506f1d07SSam Ravnborg
1001aec6487eSIngo Molnar	  This is purely to save memory: each supported CPU adds about 8KB
1002aec6487eSIngo Molnar	  to the kernel image.
1003506f1d07SSam Ravnborg
1004506f1d07SSam Ravnborgconfig SCHED_SMT
1005506f1d07SSam Ravnborg	bool "SMT (Hyperthreading) scheduler support"
1006c8e56d20SBorislav Petkov	depends on SMP
10078f9ca475SIngo Molnar	---help---
1008506f1d07SSam Ravnborg	  SMT scheduler support improves the CPU scheduler's decision making
1009506f1d07SSam Ravnborg	  when dealing with Intel Pentium 4 chips with HyperThreading at a
1010506f1d07SSam Ravnborg	  cost of slightly increased overhead in some places. If unsure say
1011506f1d07SSam Ravnborg	  N here.
1012506f1d07SSam Ravnborg
1013506f1d07SSam Ravnborgconfig SCHED_MC
10143c2362e6SHarvey Harrison	def_bool y
10153c2362e6SHarvey Harrison	prompt "Multi-core scheduler support"
1016c8e56d20SBorislav Petkov	depends on SMP
10178f9ca475SIngo Molnar	---help---
1018506f1d07SSam Ravnborg	  Multi-core scheduler support improves the CPU scheduler's decision
1019506f1d07SSam Ravnborg	  making when dealing with multi-core CPU chips at a cost of slightly
1020506f1d07SSam Ravnborg	  increased overhead in some places. If unsure say N here.
1021506f1d07SSam Ravnborg
1022de966cf4STim Chenconfig SCHED_MC_PRIO
1023de966cf4STim Chen	bool "CPU core priorities scheduler support"
10240a21fc12SIngo Molnar	depends on SCHED_MC && CPU_SUP_INTEL
10250a21fc12SIngo Molnar	select X86_INTEL_PSTATE
10260a21fc12SIngo Molnar	select CPU_FREQ
1027de966cf4STim Chen	default y
10285e76b2abSTim Chen	---help---
1029de966cf4STim Chen	  Intel Turbo Boost Max Technology 3.0 enabled CPUs have a
1030de966cf4STim Chen	  core ordering determined at manufacturing time, which allows
1031de966cf4STim Chen	  certain cores to reach higher turbo frequencies (when running
1032de966cf4STim Chen	  single threaded workloads) than others.
1033de966cf4STim Chen
1034de966cf4STim Chen	  Enabling this kernel feature teaches the scheduler about
1035de966cf4STim Chen	  the TBM3 (aka ITMT) priority order of the CPU cores and adjusts the
1036de966cf4STim Chen	  scheduler's CPU selection logic accordingly, so that higher
1037de966cf4STim Chen	  overall system performance can be achieved.
1038de966cf4STim Chen
1039de966cf4STim Chen	  This feature will have no effect on CPUs without this feature.
1040de966cf4STim Chen
1041de966cf4STim Chen	  If unsure say Y here.
10425e76b2abSTim Chen
1043506f1d07SSam Ravnborgsource "kernel/Kconfig.preempt"
1044506f1d07SSam Ravnborg
104530b8b006SThomas Gleixnerconfig UP_LATE_INIT
104630b8b006SThomas Gleixner       def_bool y
1047ba360f88SThomas Gleixner       depends on !SMP && X86_LOCAL_APIC
104830b8b006SThomas Gleixner
1049506f1d07SSam Ravnborgconfig X86_UP_APIC
105050849eefSJan Beulich	bool "Local APIC support on uniprocessors" if !PCI_MSI
105150849eefSJan Beulich	default PCI_MSI
105238a1dfdaSBryan O'Donoghue	depends on X86_32 && !SMP && !X86_32_NON_STANDARD
10538f9ca475SIngo Molnar	---help---
1054506f1d07SSam Ravnborg	  A local APIC (Advanced Programmable Interrupt Controller) is an
1055506f1d07SSam Ravnborg	  integrated interrupt controller in the CPU. If you have a single-CPU
1056506f1d07SSam Ravnborg	  system which has a processor with a local APIC, you can say Y here to
1057506f1d07SSam Ravnborg	  enable and use it. If you say Y here even though your machine doesn't
1058506f1d07SSam Ravnborg	  have a local APIC, then the kernel will still run with no slowdown at
1059506f1d07SSam Ravnborg	  all. The local APIC supports CPU-generated self-interrupts (timer,
1060506f1d07SSam Ravnborg	  performance counters), and the NMI watchdog which detects hard
1061506f1d07SSam Ravnborg	  lockups.
1062506f1d07SSam Ravnborg
1063506f1d07SSam Ravnborgconfig X86_UP_IOAPIC
1064506f1d07SSam Ravnborg	bool "IO-APIC support on uniprocessors"
1065506f1d07SSam Ravnborg	depends on X86_UP_APIC
10668f9ca475SIngo Molnar	---help---
1067506f1d07SSam Ravnborg	  An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an
1068506f1d07SSam Ravnborg	  SMP-capable replacement for PC-style interrupt controllers. Most
1069506f1d07SSam Ravnborg	  SMP systems and many recent uniprocessor systems have one.
1070506f1d07SSam Ravnborg
1071506f1d07SSam Ravnborg	  If you have a single-CPU system with an IO-APIC, you can say Y here
1072506f1d07SSam Ravnborg	  to use it. If you say Y here even though your machine doesn't have
1073506f1d07SSam Ravnborg	  an IO-APIC, then the kernel will still run with no slowdown at all.
1074506f1d07SSam Ravnborg
1075506f1d07SSam Ravnborgconfig X86_LOCAL_APIC
10763c2362e6SHarvey Harrison	def_bool y
10770dbc6078SThomas Petazzoni	depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC || PCI_MSI
1078b5dc8e6cSJiang Liu	select IRQ_DOMAIN_HIERARCHY
107952f518a3SJiang Liu	select PCI_MSI_IRQ_DOMAIN if PCI_MSI
1080506f1d07SSam Ravnborg
1081506f1d07SSam Ravnborgconfig X86_IO_APIC
1082b1da1e71SJan Beulich	def_bool y
1083b1da1e71SJan Beulich	depends on X86_LOCAL_APIC || X86_UP_IOAPIC
1084506f1d07SSam Ravnborg
108541b9eb26SStefan Assmannconfig X86_REROUTE_FOR_BROKEN_BOOT_IRQS
108641b9eb26SStefan Assmann	bool "Reroute for broken boot IRQs"
108741b9eb26SStefan Assmann	depends on X86_IO_APIC
10888f9ca475SIngo Molnar	---help---
108941b9eb26SStefan Assmann	  This option enables a workaround that fixes a source of
109041b9eb26SStefan Assmann	  spurious interrupts. This is recommended when threaded
109141b9eb26SStefan Assmann	  interrupt handling is used on systems where the generation of
109241b9eb26SStefan Assmann	  superfluous "boot interrupts" cannot be disabled.
109341b9eb26SStefan Assmann
109441b9eb26SStefan Assmann	  Some chipsets generate a legacy INTx "boot IRQ" when the IRQ
109541b9eb26SStefan Assmann	  entry in the chipset's IO-APIC is masked (as, e.g. the RT
109641b9eb26SStefan Assmann	  kernel does during interrupt handling). On chipsets where this
109741b9eb26SStefan Assmann	  boot IRQ generation cannot be disabled, this workaround keeps
109841b9eb26SStefan Assmann	  the original IRQ line masked so that only the equivalent "boot
109941b9eb26SStefan Assmann	  IRQ" is delivered to the CPUs. The workaround also tells the
110041b9eb26SStefan Assmann	  kernel to set up the IRQ handler on the boot IRQ line. In this
110141b9eb26SStefan Assmann	  way only one interrupt is delivered to the kernel. Otherwise
110241b9eb26SStefan Assmann	  the spurious second interrupt may cause the kernel to bring
110341b9eb26SStefan Assmann	  down (vital) interrupt lines.
110441b9eb26SStefan Assmann
110541b9eb26SStefan Assmann	  Only affects "broken" chipsets. Interrupt sharing may be
110641b9eb26SStefan Assmann	  increased on these systems.
110741b9eb26SStefan Assmann
1108506f1d07SSam Ravnborgconfig X86_MCE
1109bab9bc65SAndi Kleen	bool "Machine Check / overheating reporting"
1110648ed940SChen, Gong	select GENERIC_ALLOCATOR
1111e57dbaf7SBorislav Petkov	default y
1112506f1d07SSam Ravnborg	---help---
1113bab9bc65SAndi Kleen	  Machine Check support allows the processor to notify the
1114bab9bc65SAndi Kleen	  kernel if it detects a problem (e.g. overheating, data corruption).
1115506f1d07SSam Ravnborg	  The action the kernel takes depends on the severity of the problem,
1116bab9bc65SAndi Kleen	  ranging from warning messages to halting the machine.
11174efc0670SAndi Kleen
11185de97c9fSTony Luckconfig X86_MCELOG_LEGACY
11195de97c9fSTony Luck	bool "Support for deprecated /dev/mcelog character device"
11205de97c9fSTony Luck	depends on X86_MCE
11215de97c9fSTony Luck	---help---
11225de97c9fSTony Luck	  Enable support for /dev/mcelog which is needed by the old mcelog
11235de97c9fSTony Luck	  userspace logging daemon. Consider switching to the new generation
11245de97c9fSTony Luck	  rasdaemon solution.
11255de97c9fSTony Luck
1126506f1d07SSam Ravnborgconfig X86_MCE_INTEL
11273c2362e6SHarvey Harrison	def_bool y
11283c2362e6SHarvey Harrison	prompt "Intel MCE features"
1129c1ebf835SAndi Kleen	depends on X86_MCE && X86_LOCAL_APIC
11308f9ca475SIngo Molnar	---help---
1131506f1d07SSam Ravnborg	   Additional support for intel specific MCE features such as
1132506f1d07SSam Ravnborg	   the thermal monitor.
1133506f1d07SSam Ravnborg
1134506f1d07SSam Ravnborgconfig X86_MCE_AMD
11353c2362e6SHarvey Harrison	def_bool y
11363c2362e6SHarvey Harrison	prompt "AMD MCE features"
1137f5382de9SYazen Ghannam	depends on X86_MCE && X86_LOCAL_APIC && AMD_NB
11388f9ca475SIngo Molnar	---help---
1139506f1d07SSam Ravnborg	   Additional support for AMD specific MCE features such as
1140506f1d07SSam Ravnborg	   the DRAM Error Threshold.
1141506f1d07SSam Ravnborg
11424efc0670SAndi Kleenconfig X86_ANCIENT_MCE
11436fc108a0SJan Beulich	bool "Support for old Pentium 5 / WinChip machine checks"
1144c31d9633SAndi Kleen	depends on X86_32 && X86_MCE
11454efc0670SAndi Kleen	---help---
11464efc0670SAndi Kleen	  Include support for machine check handling on old Pentium 5 or WinChip
11475065a706SMasanari Iida	  systems. These typically need to be enabled explicitly on the command
11484efc0670SAndi Kleen	  line.
11494efc0670SAndi Kleen
1150b2762686SAndi Kleenconfig X86_MCE_THRESHOLD
1151b2762686SAndi Kleen	depends on X86_MCE_AMD || X86_MCE_INTEL
11526fc108a0SJan Beulich	def_bool y
1153b2762686SAndi Kleen
1154ea149b36SAndi Kleenconfig X86_MCE_INJECT
1155bc8e80d5SBorislav Petkov	depends on X86_MCE && X86_LOCAL_APIC && DEBUG_FS
1156ea149b36SAndi Kleen	tristate "Machine check injector support"
1157ea149b36SAndi Kleen	---help---
1158ea149b36SAndi Kleen	  Provide support for injecting machine checks for testing purposes.
1159ea149b36SAndi Kleen	  If you don't know what a machine check is and you don't do kernel
1160ea149b36SAndi Kleen	  QA it is safe to say n.
1161ea149b36SAndi Kleen
11624efc0670SAndi Kleenconfig X86_THERMAL_VECTOR
11634efc0670SAndi Kleen	def_bool y
11645bb38adcSAndi Kleen	depends on X86_MCE_INTEL
11654efc0670SAndi Kleen
116607dc900eSPeter Zijlstrasource "arch/x86/events/Kconfig"
1167e633c65aSKan Liang
11685aef51c3SAndy Lutomirskiconfig X86_LEGACY_VM86
11691e642812SIngo Molnar	bool "Legacy VM86 support"
11705aef51c3SAndy Lutomirski	default n
1171506f1d07SSam Ravnborg	depends on X86_32
11728f9ca475SIngo Molnar	---help---
11735aef51c3SAndy Lutomirski	  This option allows user programs to put the CPU into V8086
11745aef51c3SAndy Lutomirski	  mode, which is an 80286-era approximation of 16-bit real mode.
11755aef51c3SAndy Lutomirski
11765aef51c3SAndy Lutomirski	  Some very old versions of X and/or vbetool require this option
11775aef51c3SAndy Lutomirski	  for user mode setting.  Similarly, DOSEMU will use it if
11785aef51c3SAndy Lutomirski	  available to accelerate real mode DOS programs.  However, any
11795aef51c3SAndy Lutomirski	  recent version of DOSEMU, X, or vbetool should be fully
11805aef51c3SAndy Lutomirski	  functional even without kernel VM86 support, as they will all
11811e642812SIngo Molnar	  fall back to software emulation. Nevertheless, if you are using
11821e642812SIngo Molnar	  a 16-bit DOS program where 16-bit performance matters, vm86
11831e642812SIngo Molnar	  mode might be faster than emulation and you might want to
11841e642812SIngo Molnar	  enable this option.
11855aef51c3SAndy Lutomirski
11861e642812SIngo Molnar	  Note that any app that works on a 64-bit kernel is unlikely to
11871e642812SIngo Molnar	  need this option, as 64-bit kernels don't, and can't, support
11881e642812SIngo Molnar	  V8086 mode. This option is also unrelated to 16-bit protected
11891e642812SIngo Molnar	  mode and is not needed to run most 16-bit programs under Wine.
11905aef51c3SAndy Lutomirski
11911e642812SIngo Molnar	  Enabling this option increases the complexity of the kernel
11921e642812SIngo Molnar	  and slows down exception handling a tiny bit.
11935aef51c3SAndy Lutomirski
11941e642812SIngo Molnar	  If unsure, say N here.
11955aef51c3SAndy Lutomirski
11965aef51c3SAndy Lutomirskiconfig VM86
11975aef51c3SAndy Lutomirski       bool
11985aef51c3SAndy Lutomirski       default X86_LEGACY_VM86
119934273f41SH. Peter Anvin
120034273f41SH. Peter Anvinconfig X86_16BIT
120134273f41SH. Peter Anvin	bool "Enable support for 16-bit segments" if EXPERT
120234273f41SH. Peter Anvin	default y
1203a5b9e5a2SAndy Lutomirski	depends on MODIFY_LDT_SYSCALL
120434273f41SH. Peter Anvin	---help---
120534273f41SH. Peter Anvin	  This option is required by programs like Wine to run 16-bit
120634273f41SH. Peter Anvin	  protected mode legacy code on x86 processors.  Disabling
120734273f41SH. Peter Anvin	  this option saves about 300 bytes on i386, or around 6K text
120834273f41SH. Peter Anvin	  plus 16K runtime memory on x86-64,
120934273f41SH. Peter Anvin
121034273f41SH. Peter Anvinconfig X86_ESPFIX32
121134273f41SH. Peter Anvin	def_bool y
121234273f41SH. Peter Anvin	depends on X86_16BIT && X86_32
1213506f1d07SSam Ravnborg
1214197725deSH. Peter Anvinconfig X86_ESPFIX64
1215197725deSH. Peter Anvin	def_bool y
121634273f41SH. Peter Anvin	depends on X86_16BIT && X86_64
1217506f1d07SSam Ravnborg
12181ad83c85SAndy Lutomirskiconfig X86_VSYSCALL_EMULATION
12191ad83c85SAndy Lutomirski       bool "Enable vsyscall emulation" if EXPERT
12201ad83c85SAndy Lutomirski       default y
12211ad83c85SAndy Lutomirski       depends on X86_64
12221ad83c85SAndy Lutomirski       ---help---
12231ad83c85SAndy Lutomirski	 This enables emulation of the legacy vsyscall page.  Disabling
12241ad83c85SAndy Lutomirski	 it is roughly equivalent to booting with vsyscall=none, except
12251ad83c85SAndy Lutomirski	 that it will also disable the helpful warning if a program
12261ad83c85SAndy Lutomirski	 tries to use a vsyscall.  With this option set to N, offending
12271ad83c85SAndy Lutomirski	 programs will just segfault, citing addresses of the form
12281ad83c85SAndy Lutomirski	 0xffffffffff600?00.
12291ad83c85SAndy Lutomirski
12301ad83c85SAndy Lutomirski	 This option is required by many programs built before 2013, and
12311ad83c85SAndy Lutomirski	 care should be used even with newer programs if set to N.
12321ad83c85SAndy Lutomirski
12331ad83c85SAndy Lutomirski	 Disabling this option saves about 7K of kernel size and
12341ad83c85SAndy Lutomirski	 possibly 4K of additional runtime pagetable memory.
12351ad83c85SAndy Lutomirski
1236506f1d07SSam Ravnborgconfig TOSHIBA
1237506f1d07SSam Ravnborg	tristate "Toshiba Laptop support"
1238506f1d07SSam Ravnborg	depends on X86_32
1239506f1d07SSam Ravnborg	---help---
1240506f1d07SSam Ravnborg	  This adds a driver to safely access the System Management Mode of
1241506f1d07SSam Ravnborg	  the CPU on Toshiba portables with a genuine Toshiba BIOS. It does
1242506f1d07SSam Ravnborg	  not work on models with a Phoenix BIOS. The System Management Mode
1243506f1d07SSam Ravnborg	  is used to set the BIOS and power saving options on Toshiba portables.
1244506f1d07SSam Ravnborg
1245506f1d07SSam Ravnborg	  For information on utilities to make use of this driver see the
1246506f1d07SSam Ravnborg	  Toshiba Linux utilities web site at:
1247506f1d07SSam Ravnborg	  <http://www.buzzard.org.uk/toshiba/>.
1248506f1d07SSam Ravnborg
1249506f1d07SSam Ravnborg	  Say Y if you intend to run this kernel on a Toshiba portable.
1250506f1d07SSam Ravnborg	  Say N otherwise.
1251506f1d07SSam Ravnborg
1252506f1d07SSam Ravnborgconfig I8K
1253039ae585SPali Rohár	tristate "Dell i8k legacy laptop support"
1254949a9d70SJean Delvare	select HWMON
1255039ae585SPali Rohár	select SENSORS_DELL_SMM
1256506f1d07SSam Ravnborg	---help---
1257039ae585SPali Rohár	  This option enables legacy /proc/i8k userspace interface in hwmon
1258039ae585SPali Rohár	  dell-smm-hwmon driver. Character file /proc/i8k reports bios version,
1259039ae585SPali Rohár	  temperature and allows controlling fan speeds of Dell laptops via
1260039ae585SPali Rohár	  System Management Mode. For old Dell laptops (like Dell Inspiron 8000)
1261039ae585SPali Rohár	  it reports also power and hotkey status. For fan speed control is
1262039ae585SPali Rohár	  needed userspace package i8kutils.
1263506f1d07SSam Ravnborg
1264039ae585SPali Rohár	  Say Y if you intend to run this kernel on old Dell laptops or want to
1265039ae585SPali Rohár	  use userspace package i8kutils.
1266506f1d07SSam Ravnborg	  Say N otherwise.
1267506f1d07SSam Ravnborg
1268506f1d07SSam Ravnborgconfig X86_REBOOTFIXUPS
12699ba16087SJan Beulich	bool "Enable X86 board specific fixups for reboot"
12709ba16087SJan Beulich	depends on X86_32
1271506f1d07SSam Ravnborg	---help---
1272506f1d07SSam Ravnborg	  This enables chipset and/or board specific fixups to be done
1273506f1d07SSam Ravnborg	  in order to get reboot to work correctly. This is only needed on
1274506f1d07SSam Ravnborg	  some combinations of hardware and BIOS. The symptom, for which
1275506f1d07SSam Ravnborg	  this config is intended, is when reboot ends with a stalled/hung
1276506f1d07SSam Ravnborg	  system.
1277506f1d07SSam Ravnborg
1278506f1d07SSam Ravnborg	  Currently, the only fixup is for the Geode machines using
12795e3a77e9SFlorian Fainelli	  CS5530A and CS5536 chipsets and the RDC R-321x SoC.
1280506f1d07SSam Ravnborg
1281506f1d07SSam Ravnborg	  Say Y if you want to enable the fixup. Currently, it's safe to
1282506f1d07SSam Ravnborg	  enable this option even if you don't need it.
1283506f1d07SSam Ravnborg	  Say N otherwise.
1284506f1d07SSam Ravnborg
1285506f1d07SSam Ravnborgconfig MICROCODE
12869a2bc335SBorislav Petkov	bool "CPU microcode loading support"
12879a2bc335SBorislav Petkov	default y
128880030e3dSBorislav Petkov	depends on CPU_SUP_AMD || CPU_SUP_INTEL
1289506f1d07SSam Ravnborg	select FW_LOADER
1290506f1d07SSam Ravnborg	---help---
1291506f1d07SSam Ravnborg	  If you say Y here, you will be able to update the microcode on
12925f9c01aaSBorislav Petkov	  Intel and AMD processors. The Intel support is for the IA32 family,
12935f9c01aaSBorislav Petkov	  e.g. Pentium Pro, Pentium II, Pentium III, Pentium 4, Xeon etc. The
12945f9c01aaSBorislav Petkov	  AMD support is for families 0x10 and later. You will obviously need
12955f9c01aaSBorislav Petkov	  the actual microcode binary data itself which is not shipped with
12965f9c01aaSBorislav Petkov	  the Linux kernel.
1297506f1d07SSam Ravnborg
12985f9c01aaSBorislav Petkov	  The preferred method to load microcode from a detached initrd is described
12991897a969SJaak Ristioja	  in Documentation/x86/microcode.txt. For that you need to enable
13005f9c01aaSBorislav Petkov	  CONFIG_BLK_DEV_INITRD in order for the loader to be able to scan the
13015f9c01aaSBorislav Petkov	  initrd for microcode blobs.
1302506f1d07SSam Ravnborg
1303c508c46eSBenjamin Gilbert	  In addition, you can build the microcode into the kernel. For that you
1304c508c46eSBenjamin Gilbert	  need to add the vendor-supplied microcode to the CONFIG_EXTRA_FIRMWARE
1305c508c46eSBenjamin Gilbert	  config option.
1306506f1d07SSam Ravnborg
13078d86f390SPeter Orubaconfig MICROCODE_INTEL
1308e43f6e67SBorislav Petkov	bool "Intel microcode loading support"
13098d86f390SPeter Oruba	depends on MICROCODE
13108d86f390SPeter Oruba	default MICROCODE
13118d86f390SPeter Oruba	select FW_LOADER
13128f9ca475SIngo Molnar	---help---
13138d86f390SPeter Oruba	  This options enables microcode patch loading support for Intel
13148d86f390SPeter Oruba	  processors.
13158d86f390SPeter Oruba
1316b8989db9SAlan	  For the current Intel microcode data package go to
1317b8989db9SAlan	  <https://downloadcenter.intel.com> and search for
1318b8989db9SAlan	  'Linux Processor Microcode Data File'.
13198d86f390SPeter Oruba
132080cc9f10SPeter Orubaconfig MICROCODE_AMD
1321e43f6e67SBorislav Petkov	bool "AMD microcode loading support"
132280cc9f10SPeter Oruba	depends on MICROCODE
132380cc9f10SPeter Oruba	select FW_LOADER
13248f9ca475SIngo Molnar	---help---
132580cc9f10SPeter Oruba	  If you select this option, microcode patch loading support for AMD
132680cc9f10SPeter Oruba	  processors will be enabled.
132780cc9f10SPeter Oruba
1328506f1d07SSam Ravnborgconfig MICROCODE_OLD_INTERFACE
13293c2362e6SHarvey Harrison	def_bool y
1330506f1d07SSam Ravnborg	depends on MICROCODE
1331506f1d07SSam Ravnborg
1332506f1d07SSam Ravnborgconfig X86_MSR
1333506f1d07SSam Ravnborg	tristate "/dev/cpu/*/msr - Model-specific register support"
13348f9ca475SIngo Molnar	---help---
1335506f1d07SSam Ravnborg	  This device gives privileged processes access to the x86
1336506f1d07SSam Ravnborg	  Model-Specific Registers (MSRs).  It is a character device with
1337506f1d07SSam Ravnborg	  major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr.
1338506f1d07SSam Ravnborg	  MSR accesses are directed to a specific CPU on multi-processor
1339506f1d07SSam Ravnborg	  systems.
1340506f1d07SSam Ravnborg
1341506f1d07SSam Ravnborgconfig X86_CPUID
1342506f1d07SSam Ravnborg	tristate "/dev/cpu/*/cpuid - CPU information support"
13438f9ca475SIngo Molnar	---help---
1344506f1d07SSam Ravnborg	  This device gives processes access to the x86 CPUID instruction to
1345506f1d07SSam Ravnborg	  be executed on a specific processor.  It is a character device
1346506f1d07SSam Ravnborg	  with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to
1347506f1d07SSam Ravnborg	  /dev/cpu/31/cpuid.
1348506f1d07SSam Ravnborg
1349506f1d07SSam Ravnborgchoice
1350506f1d07SSam Ravnborg	prompt "High Memory Support"
13516fc108a0SJan Beulich	default HIGHMEM4G
1352506f1d07SSam Ravnborg	depends on X86_32
1353506f1d07SSam Ravnborg
1354506f1d07SSam Ravnborgconfig NOHIGHMEM
1355506f1d07SSam Ravnborg	bool "off"
1356506f1d07SSam Ravnborg	---help---
1357506f1d07SSam Ravnborg	  Linux can use up to 64 Gigabytes of physical memory on x86 systems.
1358506f1d07SSam Ravnborg	  However, the address space of 32-bit x86 processors is only 4
1359506f1d07SSam Ravnborg	  Gigabytes large. That means that, if you have a large amount of
1360506f1d07SSam Ravnborg	  physical memory, not all of it can be "permanently mapped" by the
1361506f1d07SSam Ravnborg	  kernel. The physical memory that's not permanently mapped is called
1362506f1d07SSam Ravnborg	  "high memory".
1363506f1d07SSam Ravnborg
1364506f1d07SSam Ravnborg	  If you are compiling a kernel which will never run on a machine with
1365506f1d07SSam Ravnborg	  more than 1 Gigabyte total physical RAM, answer "off" here (default
1366506f1d07SSam Ravnborg	  choice and suitable for most users). This will result in a "3GB/1GB"
1367506f1d07SSam Ravnborg	  split: 3GB are mapped so that each process sees a 3GB virtual memory
1368506f1d07SSam Ravnborg	  space and the remaining part of the 4GB virtual memory space is used
1369506f1d07SSam Ravnborg	  by the kernel to permanently map as much physical memory as
1370506f1d07SSam Ravnborg	  possible.
1371506f1d07SSam Ravnborg
1372506f1d07SSam Ravnborg	  If the machine has between 1 and 4 Gigabytes physical RAM, then
1373506f1d07SSam Ravnborg	  answer "4GB" here.
1374506f1d07SSam Ravnborg
1375506f1d07SSam Ravnborg	  If more than 4 Gigabytes is used then answer "64GB" here. This
1376506f1d07SSam Ravnborg	  selection turns Intel PAE (Physical Address Extension) mode on.
1377506f1d07SSam Ravnborg	  PAE implements 3-level paging on IA32 processors. PAE is fully
1378506f1d07SSam Ravnborg	  supported by Linux, PAE mode is implemented on all recent Intel
1379506f1d07SSam Ravnborg	  processors (Pentium Pro and better). NOTE: If you say "64GB" here,
1380506f1d07SSam Ravnborg	  then the kernel will not boot on CPUs that don't support PAE!
1381506f1d07SSam Ravnborg
1382506f1d07SSam Ravnborg	  The actual amount of total physical memory will either be
1383506f1d07SSam Ravnborg	  auto detected or can be forced by using a kernel command line option
1384506f1d07SSam Ravnborg	  such as "mem=256M". (Try "man bootparam" or see the documentation of
1385506f1d07SSam Ravnborg	  your boot loader (lilo or loadlin) about how to pass options to the
1386506f1d07SSam Ravnborg	  kernel at boot time.)
1387506f1d07SSam Ravnborg
1388506f1d07SSam Ravnborg	  If unsure, say "off".
1389506f1d07SSam Ravnborg
1390506f1d07SSam Ravnborgconfig HIGHMEM4G
1391506f1d07SSam Ravnborg	bool "4GB"
13928f9ca475SIngo Molnar	---help---
1393506f1d07SSam Ravnborg	  Select this if you have a 32-bit processor and between 1 and 4
1394506f1d07SSam Ravnborg	  gigabytes of physical RAM.
1395506f1d07SSam Ravnborg
1396506f1d07SSam Ravnborgconfig HIGHMEM64G
1397506f1d07SSam Ravnborg	bool "64GB"
139869b8d3fcSMatthew Whitehead	depends on !M486 && !M586 && !M586TSC && !M586MMX && !MGEODE_LX && !MGEODEGX1 && !MCYRIXIII && !MELAN && !MWINCHIPC6 && !WINCHIP3D && !MK6
1399506f1d07SSam Ravnborg	select X86_PAE
14008f9ca475SIngo Molnar	---help---
1401506f1d07SSam Ravnborg	  Select this if you have a 32-bit processor and more than 4
1402506f1d07SSam Ravnborg	  gigabytes of physical RAM.
1403506f1d07SSam Ravnborg
1404506f1d07SSam Ravnborgendchoice
1405506f1d07SSam Ravnborg
1406506f1d07SSam Ravnborgchoice
14076a108a14SDavid Rientjes	prompt "Memory split" if EXPERT
1408506f1d07SSam Ravnborg	default VMSPLIT_3G
1409506f1d07SSam Ravnborg	depends on X86_32
14108f9ca475SIngo Molnar	---help---
1411506f1d07SSam Ravnborg	  Select the desired split between kernel and user memory.
1412506f1d07SSam Ravnborg
1413506f1d07SSam Ravnborg	  If the address range available to the kernel is less than the
1414506f1d07SSam Ravnborg	  physical memory installed, the remaining memory will be available
1415506f1d07SSam Ravnborg	  as "high memory". Accessing high memory is a little more costly
1416506f1d07SSam Ravnborg	  than low memory, as it needs to be mapped into the kernel first.
1417506f1d07SSam Ravnborg	  Note that increasing the kernel address space limits the range
1418506f1d07SSam Ravnborg	  available to user programs, making the address space there
1419506f1d07SSam Ravnborg	  tighter.  Selecting anything other than the default 3G/1G split
1420506f1d07SSam Ravnborg	  will also likely make your kernel incompatible with binary-only
1421506f1d07SSam Ravnborg	  kernel modules.
1422506f1d07SSam Ravnborg
1423506f1d07SSam Ravnborg	  If you are not absolutely sure what you are doing, leave this
1424506f1d07SSam Ravnborg	  option alone!
1425506f1d07SSam Ravnborg
1426506f1d07SSam Ravnborg	config VMSPLIT_3G
1427506f1d07SSam Ravnborg		bool "3G/1G user/kernel split"
1428506f1d07SSam Ravnborg	config VMSPLIT_3G_OPT
1429506f1d07SSam Ravnborg		depends on !X86_PAE
1430506f1d07SSam Ravnborg		bool "3G/1G user/kernel split (for full 1G low memory)"
1431506f1d07SSam Ravnborg	config VMSPLIT_2G
1432506f1d07SSam Ravnborg		bool "2G/2G user/kernel split"
1433506f1d07SSam Ravnborg	config VMSPLIT_2G_OPT
1434506f1d07SSam Ravnborg		depends on !X86_PAE
1435506f1d07SSam Ravnborg		bool "2G/2G user/kernel split (for full 2G low memory)"
1436506f1d07SSam Ravnborg	config VMSPLIT_1G
1437506f1d07SSam Ravnborg		bool "1G/3G user/kernel split"
1438506f1d07SSam Ravnborgendchoice
1439506f1d07SSam Ravnborg
1440506f1d07SSam Ravnborgconfig PAGE_OFFSET
1441506f1d07SSam Ravnborg	hex
1442506f1d07SSam Ravnborg	default 0xB0000000 if VMSPLIT_3G_OPT
1443506f1d07SSam Ravnborg	default 0x80000000 if VMSPLIT_2G
1444506f1d07SSam Ravnborg	default 0x78000000 if VMSPLIT_2G_OPT
1445506f1d07SSam Ravnborg	default 0x40000000 if VMSPLIT_1G
1446506f1d07SSam Ravnborg	default 0xC0000000
1447506f1d07SSam Ravnborg	depends on X86_32
1448506f1d07SSam Ravnborg
1449506f1d07SSam Ravnborgconfig HIGHMEM
14503c2362e6SHarvey Harrison	def_bool y
1451506f1d07SSam Ravnborg	depends on X86_32 && (HIGHMEM64G || HIGHMEM4G)
1452506f1d07SSam Ravnborg
1453506f1d07SSam Ravnborgconfig X86_PAE
14549ba16087SJan Beulich	bool "PAE (Physical Address Extension) Support"
1455506f1d07SSam Ravnborg	depends on X86_32 && !HIGHMEM4G
14569d99c712SChristian Melki	select SWIOTLB
14578f9ca475SIngo Molnar	---help---
1458506f1d07SSam Ravnborg	  PAE is required for NX support, and furthermore enables
1459506f1d07SSam Ravnborg	  larger swapspace support for non-overcommit purposes. It
1460506f1d07SSam Ravnborg	  has the cost of more pagetable lookup overhead, and also
1461506f1d07SSam Ravnborg	  consumes more pagetable space per process.
1462506f1d07SSam Ravnborg
146377ef56e4SKirill A. Shutemovconfig X86_5LEVEL
146477ef56e4SKirill A. Shutemov	bool "Enable 5-level page tables support"
1465eedb92abSKirill A. Shutemov	select DYNAMIC_MEMORY_LAYOUT
1466162434e7SKirill A. Shutemov	select SPARSEMEM_VMEMMAP
146777ef56e4SKirill A. Shutemov	depends on X86_64
146877ef56e4SKirill A. Shutemov	---help---
146977ef56e4SKirill A. Shutemov	  5-level paging enables access to larger address space:
147077ef56e4SKirill A. Shutemov	  upto 128 PiB of virtual address space and 4 PiB of
147177ef56e4SKirill A. Shutemov	  physical address space.
147277ef56e4SKirill A. Shutemov
147377ef56e4SKirill A. Shutemov	  It will be supported by future Intel CPUs.
147477ef56e4SKirill A. Shutemov
14756657fca0SKirill A. Shutemov	  A kernel with the option enabled can be booted on machines that
14766657fca0SKirill A. Shutemov	  support 4- or 5-level paging.
147777ef56e4SKirill A. Shutemov
147877ef56e4SKirill A. Shutemov	  See Documentation/x86/x86_64/5level-paging.txt for more
147977ef56e4SKirill A. Shutemov	  information.
148077ef56e4SKirill A. Shutemov
148177ef56e4SKirill A. Shutemov	  Say N if unsure.
148277ef56e4SKirill A. Shutemov
1483600715dcSJeremy Fitzhardingeconfig ARCH_PHYS_ADDR_T_64BIT
14843120e25eSJan Beulich	def_bool y
14853120e25eSJan Beulich	depends on X86_64 || X86_PAE
1486600715dcSJeremy Fitzhardinge
148766f2b061SFUJITA Tomonoriconfig ARCH_DMA_ADDR_T_64BIT
14883120e25eSJan Beulich	def_bool y
14893120e25eSJan Beulich	depends on X86_64 || HIGHMEM64G
149066f2b061SFUJITA Tomonori
149110971ab2SIngo Molnarconfig X86_DIRECT_GBPAGES
1492e5008abeSLuis R. Rodriguez	def_bool y
14934675ff05SLevin, Alexander (Sasha Levin)	depends on X86_64 && !DEBUG_PAGEALLOC
14948f9ca475SIngo Molnar	---help---
149510971ab2SIngo Molnar	  Certain kernel features effectively disable kernel
149610971ab2SIngo Molnar	  linear 1 GB mappings (even if the CPU otherwise
149710971ab2SIngo Molnar	  supports them), so don't confuse the user by printing
149810971ab2SIngo Molnar	  that we have them enabled.
14999e899816SNick Piggin
15007744ccdbSTom Lendackyconfig ARCH_HAS_MEM_ENCRYPT
15017744ccdbSTom Lendacky	def_bool y
15027744ccdbSTom Lendacky
15037744ccdbSTom Lendackyconfig AMD_MEM_ENCRYPT
15047744ccdbSTom Lendacky	bool "AMD Secure Memory Encryption (SME) support"
15057744ccdbSTom Lendacky	depends on X86_64 && CPU_SUP_AMD
15067744ccdbSTom Lendacky	---help---
15077744ccdbSTom Lendacky	  Say yes to enable support for the encryption of system memory.
15087744ccdbSTom Lendacky	  This requires an AMD processor that supports Secure Memory
15097744ccdbSTom Lendacky	  Encryption (SME).
15107744ccdbSTom Lendacky
15117744ccdbSTom Lendackyconfig AMD_MEM_ENCRYPT_ACTIVE_BY_DEFAULT
15127744ccdbSTom Lendacky	bool "Activate AMD Secure Memory Encryption (SME) by default"
15137744ccdbSTom Lendacky	default y
15147744ccdbSTom Lendacky	depends on AMD_MEM_ENCRYPT
15157744ccdbSTom Lendacky	---help---
15167744ccdbSTom Lendacky	  Say yes to have system memory encrypted by default if running on
15177744ccdbSTom Lendacky	  an AMD processor that supports Secure Memory Encryption (SME).
15187744ccdbSTom Lendacky
15197744ccdbSTom Lendacky	  If set to Y, then the encryption of system memory can be
15207744ccdbSTom Lendacky	  deactivated with the mem_encrypt=off command line option.
15217744ccdbSTom Lendacky
15227744ccdbSTom Lendacky	  If set to N, then the encryption of system memory can be
15237744ccdbSTom Lendacky	  activated with the mem_encrypt=on command line option.
15247744ccdbSTom Lendacky
1525f88a68faSTom Lendackyconfig ARCH_USE_MEMREMAP_PROT
1526f88a68faSTom Lendacky	def_bool y
1527f88a68faSTom Lendacky	depends on AMD_MEM_ENCRYPT
1528f88a68faSTom Lendacky
1529506f1d07SSam Ravnborg# Common NUMA Features
1530506f1d07SSam Ravnborgconfig NUMA
1531fd51b2d7SKOSAKI Motohiro	bool "Numa Memory Allocation and Scheduler Support"
1532506f1d07SSam Ravnborg	depends on SMP
1533b5660ba7SH. Peter Anvin	depends on X86_64 || (X86_32 && HIGHMEM64G && X86_BIGSMP)
1534b5660ba7SH. Peter Anvin	default y if X86_BIGSMP
15358f9ca475SIngo Molnar	---help---
1536506f1d07SSam Ravnborg	  Enable NUMA (Non Uniform Memory Access) support.
1537fd51b2d7SKOSAKI Motohiro
1538506f1d07SSam Ravnborg	  The kernel will try to allocate memory used by a CPU on the
1539506f1d07SSam Ravnborg	  local memory controller of the CPU and add some more
1540506f1d07SSam Ravnborg	  NUMA awareness to the kernel.
1541506f1d07SSam Ravnborg
1542c280ea5eSIngo Molnar	  For 64-bit this is recommended if the system is Intel Core i7
1543fd51b2d7SKOSAKI Motohiro	  (or later), AMD Opteron, or EM64T NUMA.
1544fd51b2d7SKOSAKI Motohiro
1545b5660ba7SH. Peter Anvin	  For 32-bit this is only needed if you boot a 32-bit
15467cf6c945SDavid Rientjes	  kernel on a 64-bit NUMA platform.
1547fd51b2d7SKOSAKI Motohiro
1548fd51b2d7SKOSAKI Motohiro	  Otherwise, you should say N.
1549506f1d07SSam Ravnborg
1550eec1d4faSHans Rosenfeldconfig AMD_NUMA
15513c2362e6SHarvey Harrison	def_bool y
15523c2362e6SHarvey Harrison	prompt "Old style AMD Opteron NUMA detection"
15535da0ef9aSTejun Heo	depends on X86_64 && NUMA && PCI
15548f9ca475SIngo Molnar	---help---
1555eec1d4faSHans Rosenfeld	  Enable AMD NUMA node topology detection.  You should say Y here if
1556eec1d4faSHans Rosenfeld	  you have a multi processor AMD system. This uses an old method to
1557eec1d4faSHans Rosenfeld	  read the NUMA configuration directly from the builtin Northbridge
1558eec1d4faSHans Rosenfeld	  of Opteron. It is recommended to use X86_64_ACPI_NUMA instead,
1559eec1d4faSHans Rosenfeld	  which also takes priority if both are compiled in.
1560506f1d07SSam Ravnborg
1561506f1d07SSam Ravnborgconfig X86_64_ACPI_NUMA
15623c2362e6SHarvey Harrison	def_bool y
15633c2362e6SHarvey Harrison	prompt "ACPI NUMA detection"
1564506f1d07SSam Ravnborg	depends on X86_64 && NUMA && ACPI && PCI
1565506f1d07SSam Ravnborg	select ACPI_NUMA
15668f9ca475SIngo Molnar	---help---
1567506f1d07SSam Ravnborg	  Enable ACPI SRAT based node topology detection.
1568506f1d07SSam Ravnborg
15696ec6e0d9SSuresh Siddha# Some NUMA nodes have memory ranges that span
15706ec6e0d9SSuresh Siddha# other nodes.  Even though a pfn is valid and
15716ec6e0d9SSuresh Siddha# between a node's start and end pfns, it may not
15726ec6e0d9SSuresh Siddha# reside on that node.  See memmap_init_zone()
15736ec6e0d9SSuresh Siddha# for details.
15746ec6e0d9SSuresh Siddhaconfig NODES_SPAN_OTHER_NODES
15756ec6e0d9SSuresh Siddha	def_bool y
15766ec6e0d9SSuresh Siddha	depends on X86_64_ACPI_NUMA
15776ec6e0d9SSuresh Siddha
1578506f1d07SSam Ravnborgconfig NUMA_EMU
1579506f1d07SSam Ravnborg	bool "NUMA emulation"
15801b7e03efSTejun Heo	depends on NUMA
15818f9ca475SIngo Molnar	---help---
1582506f1d07SSam Ravnborg	  Enable NUMA emulation. A flat machine will be split
1583506f1d07SSam Ravnborg	  into virtual nodes when booted with "numa=fake=N", where N is the
1584506f1d07SSam Ravnborg	  number of nodes. This is only useful for debugging.
1585506f1d07SSam Ravnborg
1586506f1d07SSam Ravnborgconfig NODES_SHIFT
1587d25e26b6SLinus Torvalds	int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP
158851591e31SDavid Rientjes	range 1 10
158951591e31SDavid Rientjes	default "10" if MAXSMP
1590506f1d07SSam Ravnborg	default "6" if X86_64
1591506f1d07SSam Ravnborg	default "3"
1592506f1d07SSam Ravnborg	depends on NEED_MULTIPLE_NODES
15938f9ca475SIngo Molnar	---help---
15941184dc2fSMike Travis	  Specify the maximum number of NUMA Nodes available on the target
1595692105b8SMatt LaPlante	  system.  Increases memory reserved to accommodate various tables.
1596506f1d07SSam Ravnborg
1597506f1d07SSam Ravnborgconfig ARCH_HAVE_MEMORY_PRESENT
15983c2362e6SHarvey Harrison	def_bool y
1599506f1d07SSam Ravnborg	depends on X86_32 && DISCONTIGMEM
1600506f1d07SSam Ravnborg
1601506f1d07SSam Ravnborgconfig ARCH_FLATMEM_ENABLE
1602506f1d07SSam Ravnborg	def_bool y
16033b16651fSTejun Heo	depends on X86_32 && !NUMA
1604506f1d07SSam Ravnborg
1605506f1d07SSam Ravnborgconfig ARCH_DISCONTIGMEM_ENABLE
1606506f1d07SSam Ravnborg	def_bool y
1607b263295dSChristoph Lameter	depends on NUMA && X86_32
1608506f1d07SSam Ravnborg
1609506f1d07SSam Ravnborgconfig ARCH_DISCONTIGMEM_DEFAULT
1610506f1d07SSam Ravnborg	def_bool y
1611b263295dSChristoph Lameter	depends on NUMA && X86_32
1612b263295dSChristoph Lameter
1613506f1d07SSam Ravnborgconfig ARCH_SPARSEMEM_ENABLE
1614506f1d07SSam Ravnborg	def_bool y
16156ea30386SKees Cook	depends on X86_64 || NUMA || X86_32 || X86_32_NON_STANDARD
1616506f1d07SSam Ravnborg	select SPARSEMEM_STATIC if X86_32
1617506f1d07SSam Ravnborg	select SPARSEMEM_VMEMMAP_ENABLE if X86_64
1618506f1d07SSam Ravnborg
16193b16651fSTejun Heoconfig ARCH_SPARSEMEM_DEFAULT
16203b16651fSTejun Heo	def_bool y
16213b16651fSTejun Heo	depends on X86_64
16223b16651fSTejun Heo
1623506f1d07SSam Ravnborgconfig ARCH_SELECT_MEMORY_MODEL
1624506f1d07SSam Ravnborg	def_bool y
1625b263295dSChristoph Lameter	depends on ARCH_SPARSEMEM_ENABLE
1626506f1d07SSam Ravnborg
1627506f1d07SSam Ravnborgconfig ARCH_MEMORY_PROBE
1628a0842b70SToshi Kani	bool "Enable sysfs memory/probe interface"
16293120e25eSJan Beulich	depends on X86_64 && MEMORY_HOTPLUG
1630a0842b70SToshi Kani	help
1631a0842b70SToshi Kani	  This option enables a sysfs memory/probe interface for testing.
1632a0842b70SToshi Kani	  See Documentation/memory-hotplug.txt for more information.
1633a0842b70SToshi Kani	  If you are unsure how to answer this question, answer N.
1634506f1d07SSam Ravnborg
16353b16651fSTejun Heoconfig ARCH_PROC_KCORE_TEXT
16363b16651fSTejun Heo	def_bool y
16373b16651fSTejun Heo	depends on X86_64 && PROC_KCORE
16383b16651fSTejun Heo
1639a29815a3SAvi Kivityconfig ILLEGAL_POINTER_VALUE
1640a29815a3SAvi Kivity       hex
1641a29815a3SAvi Kivity       default 0 if X86_32
1642a29815a3SAvi Kivity       default 0xdead000000000000 if X86_64
1643a29815a3SAvi Kivity
1644506f1d07SSam Ravnborgsource "mm/Kconfig"
1645506f1d07SSam Ravnborg
16467a67832cSDan Williamsconfig X86_PMEM_LEGACY_DEVICE
16477a67832cSDan Williams	bool
16487a67832cSDan Williams
1649ec776ef6SChristoph Hellwigconfig X86_PMEM_LEGACY
16507a67832cSDan Williams	tristate "Support non-standard NVDIMMs and ADR protected memory"
16519f53f9faSDan Williams	depends on PHYS_ADDR_T_64BIT
16529f53f9faSDan Williams	depends on BLK_DEV
16537a67832cSDan Williams	select X86_PMEM_LEGACY_DEVICE
16549f53f9faSDan Williams	select LIBNVDIMM
1655ec776ef6SChristoph Hellwig	help
1656ec776ef6SChristoph Hellwig	  Treat memory marked using the non-standard e820 type of 12 as used
1657ec776ef6SChristoph Hellwig	  by the Intel Sandy Bridge-EP reference BIOS as protected memory.
1658ec776ef6SChristoph Hellwig	  The kernel will offer these regions to the 'pmem' driver so
1659ec776ef6SChristoph Hellwig	  they can be used for persistent storage.
1660ec776ef6SChristoph Hellwig
1661ec776ef6SChristoph Hellwig	  Say Y if unsure.
1662ec776ef6SChristoph Hellwig
1663506f1d07SSam Ravnborgconfig HIGHPTE
1664506f1d07SSam Ravnborg	bool "Allocate 3rd-level pagetables from highmem"
16656fc108a0SJan Beulich	depends on HIGHMEM
16668f9ca475SIngo Molnar	---help---
1667506f1d07SSam Ravnborg	  The VM uses one page table entry for each page of physical memory.
1668506f1d07SSam Ravnborg	  For systems with a lot of RAM, this can be wasteful of precious
1669506f1d07SSam Ravnborg	  low memory.  Setting this option will put user-space page table
1670506f1d07SSam Ravnborg	  entries in high memory.
1671506f1d07SSam Ravnborg
16729f077871SJeremy Fitzhardingeconfig X86_CHECK_BIOS_CORRUPTION
16739f077871SJeremy Fitzhardinge	bool "Check for low memory corruption"
16748f9ca475SIngo Molnar	---help---
16759f077871SJeremy Fitzhardinge	  Periodically check for memory corruption in low memory, which
16769f077871SJeremy Fitzhardinge	  is suspected to be caused by BIOS.  Even when enabled in the
16779f077871SJeremy Fitzhardinge	  configuration, it is disabled at runtime.  Enable it by
16789f077871SJeremy Fitzhardinge	  setting "memory_corruption_check=1" on the kernel command
16799f077871SJeremy Fitzhardinge	  line.  By default it scans the low 64k of memory every 60
16809f077871SJeremy Fitzhardinge	  seconds; see the memory_corruption_check_size and
16819f077871SJeremy Fitzhardinge	  memory_corruption_check_period parameters in
16828c27ceffSMauro Carvalho Chehab	  Documentation/admin-guide/kernel-parameters.rst to adjust this.
16839f077871SJeremy Fitzhardinge
16849f077871SJeremy Fitzhardinge	  When enabled with the default parameters, this option has
16859f077871SJeremy Fitzhardinge	  almost no overhead, as it reserves a relatively small amount
16869f077871SJeremy Fitzhardinge	  of memory and scans it infrequently.  It both detects corruption
16879f077871SJeremy Fitzhardinge	  and prevents it from affecting the running system.
16889f077871SJeremy Fitzhardinge
16899f077871SJeremy Fitzhardinge	  It is, however, intended as a diagnostic tool; if repeatable
16909f077871SJeremy Fitzhardinge	  BIOS-originated corruption always affects the same memory,
16919f077871SJeremy Fitzhardinge	  you can use memmap= to prevent the kernel from using that
16929f077871SJeremy Fitzhardinge	  memory.
16939f077871SJeremy Fitzhardinge
1694c885df50SJeremy Fitzhardingeconfig X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK
1695c885df50SJeremy Fitzhardinge	bool "Set the default setting of memory_corruption_check"
1696c885df50SJeremy Fitzhardinge	depends on X86_CHECK_BIOS_CORRUPTION
1697c885df50SJeremy Fitzhardinge	default y
16988f9ca475SIngo Molnar	---help---
1699c885df50SJeremy Fitzhardinge	  Set whether the default state of memory_corruption_check is
1700c885df50SJeremy Fitzhardinge	  on or off.
1701c885df50SJeremy Fitzhardinge
17029ea77bdbSH. Peter Anvinconfig X86_RESERVE_LOW
1703d0cd7425SH. Peter Anvin	int "Amount of low memory, in kilobytes, to reserve for the BIOS"
1704d0cd7425SH. Peter Anvin	default 64
1705d0cd7425SH. Peter Anvin	range 4 640
17068f9ca475SIngo Molnar	---help---
1707d0cd7425SH. Peter Anvin	  Specify the amount of low memory to reserve for the BIOS.
1708fc381519SIngo Molnar
1709d0cd7425SH. Peter Anvin	  The first page contains BIOS data structures that the kernel
1710d0cd7425SH. Peter Anvin	  must not use, so that page must always be reserved.
1711fc381519SIngo Molnar
1712d0cd7425SH. Peter Anvin	  By default we reserve the first 64K of physical RAM, as a
1713d0cd7425SH. Peter Anvin	  number of BIOSes are known to corrupt that memory range
1714d0cd7425SH. Peter Anvin	  during events such as suspend/resume or monitor cable
1715d0cd7425SH. Peter Anvin	  insertion, so it must not be used by the kernel.
1716fc381519SIngo Molnar
1717d0cd7425SH. Peter Anvin	  You can set this to 4 if you are absolutely sure that you
1718d0cd7425SH. Peter Anvin	  trust the BIOS to get all its memory reservations and usages
1719d0cd7425SH. Peter Anvin	  right.  If you know your BIOS have problems beyond the
1720d0cd7425SH. Peter Anvin	  default 64K area, you can set this to 640 to avoid using the
1721d0cd7425SH. Peter Anvin	  entire low memory range.
1722d0cd7425SH. Peter Anvin
1723d0cd7425SH. Peter Anvin	  If you have doubts about the BIOS (e.g. suspend/resume does
1724d0cd7425SH. Peter Anvin	  not work or there's kernel crashes after certain hardware
1725d0cd7425SH. Peter Anvin	  hotplug events) then you might want to enable
1726d0cd7425SH. Peter Anvin	  X86_CHECK_BIOS_CORRUPTION=y to allow the kernel to check
1727d0cd7425SH. Peter Anvin	  typical corruption patterns.
1728d0cd7425SH. Peter Anvin
1729d0cd7425SH. Peter Anvin	  Leave this to the default value of 64 if you are unsure.
1730fc381519SIngo Molnar
1731506f1d07SSam Ravnborgconfig MATH_EMULATION
1732506f1d07SSam Ravnborg	bool
1733a5b9e5a2SAndy Lutomirski	depends on MODIFY_LDT_SYSCALL
1734506f1d07SSam Ravnborg	prompt "Math emulation" if X86_32
1735506f1d07SSam Ravnborg	---help---
1736506f1d07SSam Ravnborg	  Linux can emulate a math coprocessor (used for floating point
1737506f1d07SSam Ravnborg	  operations) if you don't have one. 486DX and Pentium processors have
1738506f1d07SSam Ravnborg	  a math coprocessor built in, 486SX and 386 do not, unless you added
1739506f1d07SSam Ravnborg	  a 487DX or 387, respectively. (The messages during boot time can
1740506f1d07SSam Ravnborg	  give you some hints here ["man dmesg"].) Everyone needs either a
1741506f1d07SSam Ravnborg	  coprocessor or this emulation.
1742506f1d07SSam Ravnborg
1743506f1d07SSam Ravnborg	  If you don't have a math coprocessor, you need to say Y here; if you
1744506f1d07SSam Ravnborg	  say Y here even though you have a coprocessor, the coprocessor will
1745506f1d07SSam Ravnborg	  be used nevertheless. (This behavior can be changed with the kernel
1746506f1d07SSam Ravnborg	  command line option "no387", which comes handy if your coprocessor
1747506f1d07SSam Ravnborg	  is broken. Try "man bootparam" or see the documentation of your boot
1748506f1d07SSam Ravnborg	  loader (lilo or loadlin) about how to pass options to the kernel at
1749506f1d07SSam Ravnborg	  boot time.) This means that it is a good idea to say Y here if you
1750506f1d07SSam Ravnborg	  intend to use this kernel on different machines.
1751506f1d07SSam Ravnborg
1752506f1d07SSam Ravnborg	  More information about the internals of the Linux math coprocessor
1753506f1d07SSam Ravnborg	  emulation can be found in <file:arch/x86/math-emu/README>.
1754506f1d07SSam Ravnborg
1755506f1d07SSam Ravnborg	  If you are not sure, say Y; apart from resulting in a 66 KB bigger
1756506f1d07SSam Ravnborg	  kernel, it won't hurt.
1757506f1d07SSam Ravnborg
1758506f1d07SSam Ravnborgconfig MTRR
17596fc108a0SJan Beulich	def_bool y
17606a108a14SDavid Rientjes	prompt "MTRR (Memory Type Range Register) support" if EXPERT
1761506f1d07SSam Ravnborg	---help---
1762506f1d07SSam Ravnborg	  On Intel P6 family processors (Pentium Pro, Pentium II and later)
1763506f1d07SSam Ravnborg	  the Memory Type Range Registers (MTRRs) may be used to control
1764506f1d07SSam Ravnborg	  processor access to memory ranges. This is most useful if you have
1765506f1d07SSam Ravnborg	  a video (VGA) card on a PCI or AGP bus. Enabling write-combining
1766506f1d07SSam Ravnborg	  allows bus write transfers to be combined into a larger transfer
1767506f1d07SSam Ravnborg	  before bursting over the PCI/AGP bus. This can increase performance
1768506f1d07SSam Ravnborg	  of image write operations 2.5 times or more. Saying Y here creates a
1769506f1d07SSam Ravnborg	  /proc/mtrr file which may be used to manipulate your processor's
1770506f1d07SSam Ravnborg	  MTRRs. Typically the X server should use this.
1771506f1d07SSam Ravnborg
1772506f1d07SSam Ravnborg	  This code has a reasonably generic interface so that similar
1773506f1d07SSam Ravnborg	  control registers on other processors can be easily supported
1774506f1d07SSam Ravnborg	  as well:
1775506f1d07SSam Ravnborg
1776506f1d07SSam Ravnborg	  The Cyrix 6x86, 6x86MX and M II processors have Address Range
1777506f1d07SSam Ravnborg	  Registers (ARRs) which provide a similar functionality to MTRRs. For
1778506f1d07SSam Ravnborg	  these, the ARRs are used to emulate the MTRRs.
1779506f1d07SSam Ravnborg	  The AMD K6-2 (stepping 8 and above) and K6-3 processors have two
1780506f1d07SSam Ravnborg	  MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing
1781506f1d07SSam Ravnborg	  write-combining. All of these processors are supported by this code
1782506f1d07SSam Ravnborg	  and it makes sense to say Y here if you have one of them.
1783506f1d07SSam Ravnborg
1784506f1d07SSam Ravnborg	  Saying Y here also fixes a problem with buggy SMP BIOSes which only
1785506f1d07SSam Ravnborg	  set the MTRRs for the boot CPU and not for the secondary CPUs. This
1786506f1d07SSam Ravnborg	  can lead to all sorts of problems, so it's good to say Y here.
1787506f1d07SSam Ravnborg
1788506f1d07SSam Ravnborg	  You can safely say Y even if your machine doesn't have MTRRs, you'll
1789506f1d07SSam Ravnborg	  just add about 9 KB to your kernel.
1790506f1d07SSam Ravnborg
17917225e751SRandy Dunlap	  See <file:Documentation/x86/mtrr.txt> for more information.
1792506f1d07SSam Ravnborg
179395ffa243SYinghai Luconfig MTRR_SANITIZER
17942ffb3501SYinghai Lu	def_bool y
179595ffa243SYinghai Lu	prompt "MTRR cleanup support"
179695ffa243SYinghai Lu	depends on MTRR
17978f9ca475SIngo Molnar	---help---
1798aba3728cSThomas Gleixner	  Convert MTRR layout from continuous to discrete, so X drivers can
1799aba3728cSThomas Gleixner	  add writeback entries.
180095ffa243SYinghai Lu
1801aba3728cSThomas Gleixner	  Can be disabled with disable_mtrr_cleanup on the kernel command line.
1802692105b8SMatt LaPlante	  The largest mtrr entry size for a continuous block can be set with
1803aba3728cSThomas Gleixner	  mtrr_chunk_size.
180495ffa243SYinghai Lu
18052ffb3501SYinghai Lu	  If unsure, say Y.
180695ffa243SYinghai Lu
180795ffa243SYinghai Luconfig MTRR_SANITIZER_ENABLE_DEFAULT
1808f5098d62SYinghai Lu	int "MTRR cleanup enable value (0-1)"
1809f5098d62SYinghai Lu	range 0 1
1810f5098d62SYinghai Lu	default "0"
181195ffa243SYinghai Lu	depends on MTRR_SANITIZER
18128f9ca475SIngo Molnar	---help---
1813f5098d62SYinghai Lu	  Enable mtrr cleanup default value
181495ffa243SYinghai Lu
181512031a62SYinghai Luconfig MTRR_SANITIZER_SPARE_REG_NR_DEFAULT
181612031a62SYinghai Lu	int "MTRR cleanup spare reg num (0-7)"
181712031a62SYinghai Lu	range 0 7
181812031a62SYinghai Lu	default "1"
181912031a62SYinghai Lu	depends on MTRR_SANITIZER
18208f9ca475SIngo Molnar	---help---
182112031a62SYinghai Lu	  mtrr cleanup spare entries default, it can be changed via
1822aba3728cSThomas Gleixner	  mtrr_spare_reg_nr=N on the kernel command line.
182312031a62SYinghai Lu
18242e5d9c85Svenkatesh.pallipadi@intel.comconfig X86_PAT
18256fc108a0SJan Beulich	def_bool y
18266a108a14SDavid Rientjes	prompt "x86 PAT support" if EXPERT
18272a8a2719SIngo Molnar	depends on MTRR
18288f9ca475SIngo Molnar	---help---
18292e5d9c85Svenkatesh.pallipadi@intel.com	  Use PAT attributes to setup page level cache control.
1830042b78e4SVenki Pallipadi
18312e5d9c85Svenkatesh.pallipadi@intel.com	  PATs are the modern equivalents of MTRRs and are much more
18322e5d9c85Svenkatesh.pallipadi@intel.com	  flexible than MTRRs.
18332e5d9c85Svenkatesh.pallipadi@intel.com
18342e5d9c85Svenkatesh.pallipadi@intel.com	  Say N here if you see bootup problems (boot crash, boot hang,
1835042b78e4SVenki Pallipadi	  spontaneous reboots) or a non-working video driver.
18362e5d9c85Svenkatesh.pallipadi@intel.com
18372e5d9c85Svenkatesh.pallipadi@intel.com	  If unsure, say Y.
18382e5d9c85Svenkatesh.pallipadi@intel.com
183946cf98cdSVenkatesh Pallipadiconfig ARCH_USES_PG_UNCACHED
184046cf98cdSVenkatesh Pallipadi	def_bool y
184146cf98cdSVenkatesh Pallipadi	depends on X86_PAT
184246cf98cdSVenkatesh Pallipadi
1843628c6246SH. Peter Anvinconfig ARCH_RANDOM
1844628c6246SH. Peter Anvin	def_bool y
1845628c6246SH. Peter Anvin	prompt "x86 architectural random number generator" if EXPERT
1846628c6246SH. Peter Anvin	---help---
1847628c6246SH. Peter Anvin	  Enable the x86 architectural RDRAND instruction
1848628c6246SH. Peter Anvin	  (Intel Bull Mountain technology) to generate random numbers.
1849628c6246SH. Peter Anvin	  If supported, this is a high bandwidth, cryptographically
1850628c6246SH. Peter Anvin	  secure hardware random number generator.
1851628c6246SH. Peter Anvin
185251ae4a2dSH. Peter Anvinconfig X86_SMAP
185351ae4a2dSH. Peter Anvin	def_bool y
185451ae4a2dSH. Peter Anvin	prompt "Supervisor Mode Access Prevention" if EXPERT
185551ae4a2dSH. Peter Anvin	---help---
185651ae4a2dSH. Peter Anvin	  Supervisor Mode Access Prevention (SMAP) is a security
185751ae4a2dSH. Peter Anvin	  feature in newer Intel processors.  There is a small
185851ae4a2dSH. Peter Anvin	  performance cost if this enabled and turned on; there is
185951ae4a2dSH. Peter Anvin	  also a small increase in the kernel size if this is enabled.
186051ae4a2dSH. Peter Anvin
186151ae4a2dSH. Peter Anvin	  If unsure, say Y.
186251ae4a2dSH. Peter Anvin
1863aa35f896SRicardo Nericonfig X86_INTEL_UMIP
1864796ebc81SRicardo Neri	def_bool y
1865aa35f896SRicardo Neri	depends on CPU_SUP_INTEL
1866aa35f896SRicardo Neri	prompt "Intel User Mode Instruction Prevention" if EXPERT
1867aa35f896SRicardo Neri	---help---
1868aa35f896SRicardo Neri	  The User Mode Instruction Prevention (UMIP) is a security
1869aa35f896SRicardo Neri	  feature in newer Intel processors. If enabled, a general
1870796ebc81SRicardo Neri	  protection fault is issued if the SGDT, SLDT, SIDT, SMSW
1871796ebc81SRicardo Neri	  or STR instructions are executed in user mode. These instructions
1872796ebc81SRicardo Neri	  unnecessarily expose information about the hardware state.
1873796ebc81SRicardo Neri
1874796ebc81SRicardo Neri	  The vast majority of applications do not use these instructions.
1875796ebc81SRicardo Neri	  For the very few that do, software emulation is provided in
1876796ebc81SRicardo Neri	  specific cases in protected and virtual-8086 modes. Emulated
1877796ebc81SRicardo Neri	  results are dummy.
1878aa35f896SRicardo Neri
187972e9b5feSDave Hansenconfig X86_INTEL_MPX
188072e9b5feSDave Hansen	prompt "Intel MPX (Memory Protection Extensions)"
188172e9b5feSDave Hansen	def_bool n
1882df3735c5SRik van Riel	# Note: only available in 64-bit mode due to VMA flags shortage
1883df3735c5SRik van Riel	depends on CPU_SUP_INTEL && X86_64
1884df3735c5SRik van Riel	select ARCH_USES_HIGH_VMA_FLAGS
188572e9b5feSDave Hansen	---help---
188672e9b5feSDave Hansen	  MPX provides hardware features that can be used in
188772e9b5feSDave Hansen	  conjunction with compiler-instrumented code to check
188872e9b5feSDave Hansen	  memory references.  It is designed to detect buffer
188972e9b5feSDave Hansen	  overflow or underflow bugs.
189072e9b5feSDave Hansen
189172e9b5feSDave Hansen	  This option enables running applications which are
189272e9b5feSDave Hansen	  instrumented or otherwise use MPX.  It does not use MPX
189372e9b5feSDave Hansen	  itself inside the kernel or to protect the kernel
189472e9b5feSDave Hansen	  against bad memory references.
189572e9b5feSDave Hansen
189672e9b5feSDave Hansen	  Enabling this option will make the kernel larger:
189772e9b5feSDave Hansen	  ~8k of kernel text and 36 bytes of data on a 64-bit
189872e9b5feSDave Hansen	  defconfig.  It adds a long to the 'mm_struct' which
189972e9b5feSDave Hansen	  will increase the kernel memory overhead of each
190072e9b5feSDave Hansen	  process and adds some branches to paths used during
190172e9b5feSDave Hansen	  exec() and munmap().
190272e9b5feSDave Hansen
190372e9b5feSDave Hansen	  For details, see Documentation/x86/intel_mpx.txt
190472e9b5feSDave Hansen
190572e9b5feSDave Hansen	  If unsure, say N.
190672e9b5feSDave Hansen
190735e97790SDave Hansenconfig X86_INTEL_MEMORY_PROTECTION_KEYS
1908284244a9SDave Hansen	prompt "Intel Memory Protection Keys"
190935e97790SDave Hansen	def_bool y
1910284244a9SDave Hansen	# Note: only available in 64-bit mode
191135e97790SDave Hansen	depends on CPU_SUP_INTEL && X86_64
191252c8e601SIngo Molnar	select ARCH_USES_HIGH_VMA_FLAGS
191352c8e601SIngo Molnar	select ARCH_HAS_PKEYS
1914284244a9SDave Hansen	---help---
1915284244a9SDave Hansen	  Memory Protection Keys provides a mechanism for enforcing
1916284244a9SDave Hansen	  page-based protections, but without requiring modification of the
1917284244a9SDave Hansen	  page tables when an application changes protection domains.
1918284244a9SDave Hansen
1919284244a9SDave Hansen	  For details, see Documentation/x86/protection-keys.txt
1920284244a9SDave Hansen
1921284244a9SDave Hansen	  If unsure, say y.
192235e97790SDave Hansen
1923506f1d07SSam Ravnborgconfig EFI
19249ba16087SJan Beulich	bool "EFI runtime service support"
19255b83683fSHuang, Ying	depends on ACPI
1926f6ce5002SSergey Vlasov	select UCS2_STRING
1927022ee6c5SArd Biesheuvel	select EFI_RUNTIME_WRAPPERS
1928506f1d07SSam Ravnborg	---help---
19298b2cb7a8SHuang, Ying	  This enables the kernel to use EFI runtime services that are
1930506f1d07SSam Ravnborg	  available (such as the EFI variable services).
1931506f1d07SSam Ravnborg
19328b2cb7a8SHuang, Ying	  This option is only useful on systems that have EFI firmware.
19338b2cb7a8SHuang, Ying	  In addition, you should use the latest ELILO loader available
19348b2cb7a8SHuang, Ying	  at <http://elilo.sourceforge.net> in order to take advantage
19358b2cb7a8SHuang, Ying	  of EFI runtime services. However, even with this option, the
19368b2cb7a8SHuang, Ying	  resultant kernel should continue to boot on existing non-EFI
19378b2cb7a8SHuang, Ying	  platforms.
1938506f1d07SSam Ravnborg
1939291f3632SMatt Flemingconfig EFI_STUB
1940291f3632SMatt Fleming       bool "EFI stub support"
1941b16d8c23SMatt Fleming       depends on EFI && !X86_USE_3DNOW
19427b2a583aSMatt Fleming       select RELOCATABLE
1943291f3632SMatt Fleming       ---help---
1944291f3632SMatt Fleming          This kernel feature allows a bzImage to be loaded directly
1945291f3632SMatt Fleming	  by EFI firmware without the use of a bootloader.
1946291f3632SMatt Fleming
19474172fe2fSRoy Franz	  See Documentation/efi-stub.txt for more information.
19480c759662SMatt Fleming
19497d453eeeSMatt Flemingconfig EFI_MIXED
19507d453eeeSMatt Fleming	bool "EFI mixed-mode support"
19517d453eeeSMatt Fleming	depends on EFI_STUB && X86_64
19527d453eeeSMatt Fleming	---help---
19537d453eeeSMatt Fleming	   Enabling this feature allows a 64-bit kernel to be booted
19547d453eeeSMatt Fleming	   on a 32-bit firmware, provided that your CPU supports 64-bit
19557d453eeeSMatt Fleming	   mode.
19567d453eeeSMatt Fleming
19577d453eeeSMatt Fleming	   Note that it is not possible to boot a mixed-mode enabled
19587d453eeeSMatt Fleming	   kernel via the EFI boot stub - a bootloader that supports
19597d453eeeSMatt Fleming	   the EFI handover protocol must be used.
19607d453eeeSMatt Fleming
19617d453eeeSMatt Fleming	   If unsure, say N.
19627d453eeeSMatt Fleming
1963506f1d07SSam Ravnborgconfig SECCOMP
19643c2362e6SHarvey Harrison	def_bool y
19653c2362e6SHarvey Harrison	prompt "Enable seccomp to safely compute untrusted bytecode"
19668f9ca475SIngo Molnar	---help---
1967506f1d07SSam Ravnborg	  This kernel feature is useful for number crunching applications
1968506f1d07SSam Ravnborg	  that may need to compute untrusted bytecode during their
1969506f1d07SSam Ravnborg	  execution. By using pipes or other transports made available to
1970506f1d07SSam Ravnborg	  the process as file descriptors supporting the read/write
1971506f1d07SSam Ravnborg	  syscalls, it's possible to isolate those applications in
1972506f1d07SSam Ravnborg	  their own address space using seccomp. Once seccomp is
19739c0bbee8SAlexey Dobriyan	  enabled via prctl(PR_SET_SECCOMP), it cannot be disabled
1974506f1d07SSam Ravnborg	  and the task is only allowed to execute a few safe syscalls
1975506f1d07SSam Ravnborg	  defined by each seccomp mode.
1976506f1d07SSam Ravnborg
1977506f1d07SSam Ravnborg	  If unsure, say Y. Only embedded should say N here.
1978506f1d07SSam Ravnborg
1979506f1d07SSam Ravnborgsource kernel/Kconfig.hz
1980506f1d07SSam Ravnborg
1981506f1d07SSam Ravnborgconfig KEXEC
1982506f1d07SSam Ravnborg	bool "kexec system call"
19832965faa5SDave Young	select KEXEC_CORE
19848f9ca475SIngo Molnar	---help---
1985506f1d07SSam Ravnborg	  kexec is a system call that implements the ability to shutdown your
1986506f1d07SSam Ravnborg	  current kernel, and to start another kernel.  It is like a reboot
1987506f1d07SSam Ravnborg	  but it is independent of the system firmware.   And like a reboot
1988506f1d07SSam Ravnborg	  you can start any kernel with it, not just Linux.
1989506f1d07SSam Ravnborg
1990506f1d07SSam Ravnborg	  The name comes from the similarity to the exec system call.
1991506f1d07SSam Ravnborg
1992506f1d07SSam Ravnborg	  It is an ongoing process to be certain the hardware in a machine
1993506f1d07SSam Ravnborg	  is properly shutdown, so do not be surprised if this code does not
1994bf220695SGeert Uytterhoeven	  initially work for you.  As of this writing the exact hardware
1995bf220695SGeert Uytterhoeven	  interface is strongly in flux, so no good recommendation can be
1996bf220695SGeert Uytterhoeven	  made.
1997506f1d07SSam Ravnborg
199874ca317cSVivek Goyalconfig KEXEC_FILE
199974ca317cSVivek Goyal	bool "kexec file based system call"
20002965faa5SDave Young	select KEXEC_CORE
200174ca317cSVivek Goyal	select BUILD_BIN2C
200274ca317cSVivek Goyal	depends on X86_64
200374ca317cSVivek Goyal	depends on CRYPTO=y
200474ca317cSVivek Goyal	depends on CRYPTO_SHA256=y
200574ca317cSVivek Goyal	---help---
200674ca317cSVivek Goyal	  This is new version of kexec system call. This system call is
200774ca317cSVivek Goyal	  file based and takes file descriptors as system call argument
200874ca317cSVivek Goyal	  for kernel and initramfs as opposed to list of segments as
200974ca317cSVivek Goyal	  accepted by previous system call.
201074ca317cSVivek Goyal
2011b799a09fSAKASHI Takahiroconfig ARCH_HAS_KEXEC_PURGATORY
2012b799a09fSAKASHI Takahiro	def_bool KEXEC_FILE
2013b799a09fSAKASHI Takahiro
20148e7d8381SVivek Goyalconfig KEXEC_VERIFY_SIG
20158e7d8381SVivek Goyal	bool "Verify kernel signature during kexec_file_load() syscall"
201674ca317cSVivek Goyal	depends on KEXEC_FILE
20178e7d8381SVivek Goyal	---help---
20188e7d8381SVivek Goyal	  This option makes kernel signature verification mandatory for
2019d8eb8940SBorislav Petkov	  the kexec_file_load() syscall.
20208e7d8381SVivek Goyal
2021d8eb8940SBorislav Petkov	  In addition to that option, you need to enable signature
2022d8eb8940SBorislav Petkov	  verification for the corresponding kernel image type being
2023d8eb8940SBorislav Petkov	  loaded in order for this to work.
20248e7d8381SVivek Goyal
20258e7d8381SVivek Goyalconfig KEXEC_BZIMAGE_VERIFY_SIG
20268e7d8381SVivek Goyal	bool "Enable bzImage signature verification support"
20278e7d8381SVivek Goyal	depends on KEXEC_VERIFY_SIG
20288e7d8381SVivek Goyal	depends on SIGNED_PE_FILE_VERIFICATION
20298e7d8381SVivek Goyal	select SYSTEM_TRUSTED_KEYRING
20308e7d8381SVivek Goyal	---help---
20318e7d8381SVivek Goyal	  Enable bzImage signature verification support.
20328e7d8381SVivek Goyal
2033506f1d07SSam Ravnborgconfig CRASH_DUMP
203404b69447SPavel Machek	bool "kernel crash dumps"
2035506f1d07SSam Ravnborg	depends on X86_64 || (X86_32 && HIGHMEM)
20368f9ca475SIngo Molnar	---help---
2037506f1d07SSam Ravnborg	  Generate crash dump after being started by kexec.
2038506f1d07SSam Ravnborg	  This should be normally only set in special crash dump kernels
2039506f1d07SSam Ravnborg	  which are loaded in the main kernel with kexec-tools into
2040506f1d07SSam Ravnborg	  a specially reserved region and then later executed after
2041506f1d07SSam Ravnborg	  a crash by kdump/kexec. The crash dump kernel must be compiled
2042506f1d07SSam Ravnborg	  to a memory address not used by the main kernel or BIOS using
2043506f1d07SSam Ravnborg	  PHYSICAL_START, or it must be built as a relocatable image
2044506f1d07SSam Ravnborg	  (CONFIG_RELOCATABLE=y).
2045506f1d07SSam Ravnborg	  For more details see Documentation/kdump/kdump.txt
2046506f1d07SSam Ravnborg
20473ab83521SHuang Yingconfig KEXEC_JUMP
20486ea30386SKees Cook	bool "kexec jump"
2049fee7b0d8SHuang Ying	depends on KEXEC && HIBERNATION
20508f9ca475SIngo Molnar	---help---
205189081d17SHuang Ying	  Jump between original kernel and kexeced kernel and invoke
205289081d17SHuang Ying	  code in physical address mode via KEXEC
20533ab83521SHuang Ying
2054506f1d07SSam Ravnborgconfig PHYSICAL_START
20556a108a14SDavid Rientjes	hex "Physical address where the kernel is loaded" if (EXPERT || CRASH_DUMP)
2056ceefccc9SH. Peter Anvin	default "0x1000000"
20578f9ca475SIngo Molnar	---help---
2058506f1d07SSam Ravnborg	  This gives the physical address where the kernel is loaded.
2059506f1d07SSam Ravnborg
2060506f1d07SSam Ravnborg	  If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then
2061506f1d07SSam Ravnborg	  bzImage will decompress itself to above physical address and
2062506f1d07SSam Ravnborg	  run from there. Otherwise, bzImage will run from the address where
2063506f1d07SSam Ravnborg	  it has been loaded by the boot loader and will ignore above physical
2064506f1d07SSam Ravnborg	  address.
2065506f1d07SSam Ravnborg
2066506f1d07SSam Ravnborg	  In normal kdump cases one does not have to set/change this option
2067506f1d07SSam Ravnborg	  as now bzImage can be compiled as a completely relocatable image
2068506f1d07SSam Ravnborg	  (CONFIG_RELOCATABLE=y) and be used to load and run from a different
2069506f1d07SSam Ravnborg	  address. This option is mainly useful for the folks who don't want
2070506f1d07SSam Ravnborg	  to use a bzImage for capturing the crash dump and want to use a
2071506f1d07SSam Ravnborg	  vmlinux instead. vmlinux is not relocatable hence a kernel needs
2072506f1d07SSam Ravnborg	  to be specifically compiled to run from a specific memory area
2073506f1d07SSam Ravnborg	  (normally a reserved region) and this option comes handy.
2074506f1d07SSam Ravnborg
2075ceefccc9SH. Peter Anvin	  So if you are using bzImage for capturing the crash dump,
2076ceefccc9SH. Peter Anvin	  leave the value here unchanged to 0x1000000 and set
2077ceefccc9SH. Peter Anvin	  CONFIG_RELOCATABLE=y.  Otherwise if you plan to use vmlinux
2078ceefccc9SH. Peter Anvin	  for capturing the crash dump change this value to start of
2079ceefccc9SH. Peter Anvin	  the reserved region.  In other words, it can be set based on
2080ceefccc9SH. Peter Anvin	  the "X" value as specified in the "crashkernel=YM@XM"
2081ceefccc9SH. Peter Anvin	  command line boot parameter passed to the panic-ed
2082ceefccc9SH. Peter Anvin	  kernel. Please take a look at Documentation/kdump/kdump.txt
2083ceefccc9SH. Peter Anvin	  for more details about crash dumps.
2084506f1d07SSam Ravnborg
2085506f1d07SSam Ravnborg	  Usage of bzImage for capturing the crash dump is recommended as
2086506f1d07SSam Ravnborg	  one does not have to build two kernels. Same kernel can be used
2087506f1d07SSam Ravnborg	  as production kernel and capture kernel. Above option should have
2088506f1d07SSam Ravnborg	  gone away after relocatable bzImage support is introduced. But it
2089506f1d07SSam Ravnborg	  is present because there are users out there who continue to use
2090506f1d07SSam Ravnborg	  vmlinux for dump capture. This option should go away down the
2091506f1d07SSam Ravnborg	  line.
2092506f1d07SSam Ravnborg
2093506f1d07SSam Ravnborg	  Don't change this unless you know what you are doing.
2094506f1d07SSam Ravnborg
2095506f1d07SSam Ravnborgconfig RELOCATABLE
209626717808SH. Peter Anvin	bool "Build a relocatable kernel"
209726717808SH. Peter Anvin	default y
20988f9ca475SIngo Molnar	---help---
2099506f1d07SSam Ravnborg	  This builds a kernel image that retains relocation information
2100506f1d07SSam Ravnborg	  so it can be loaded someplace besides the default 1MB.
2101506f1d07SSam Ravnborg	  The relocations tend to make the kernel binary about 10% larger,
2102506f1d07SSam Ravnborg	  but are discarded at runtime.
2103506f1d07SSam Ravnborg
2104506f1d07SSam Ravnborg	  One use is for the kexec on panic case where the recovery kernel
2105506f1d07SSam Ravnborg	  must live at a different physical address than the primary
2106506f1d07SSam Ravnborg	  kernel.
2107506f1d07SSam Ravnborg
2108506f1d07SSam Ravnborg	  Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address
2109506f1d07SSam Ravnborg	  it has been loaded at and the compile time physical address
21108ab3820fSKees Cook	  (CONFIG_PHYSICAL_START) is used as the minimum location.
2111506f1d07SSam Ravnborg
21128ab3820fSKees Cookconfig RANDOMIZE_BASE
2113e8581e3dSBaoquan He	bool "Randomize the address of the kernel image (KASLR)"
21148ab3820fSKees Cook	depends on RELOCATABLE
21156807c846SIngo Molnar	default y
21168ab3820fSKees Cook	---help---
2117e8581e3dSBaoquan He	  In support of Kernel Address Space Layout Randomization (KASLR),
2118e8581e3dSBaoquan He	  this randomizes the physical address at which the kernel image
2119e8581e3dSBaoquan He	  is decompressed and the virtual address where the kernel
2120e8581e3dSBaoquan He	  image is mapped, as a security feature that deters exploit
2121e8581e3dSBaoquan He	  attempts relying on knowledge of the location of kernel
2122e8581e3dSBaoquan He	  code internals.
2123e8581e3dSBaoquan He
2124ed9f007eSKees Cook	  On 64-bit, the kernel physical and virtual addresses are
2125ed9f007eSKees Cook	  randomized separately. The physical address will be anywhere
2126ed9f007eSKees Cook	  between 16MB and the top of physical memory (up to 64TB). The
2127ed9f007eSKees Cook	  virtual address will be randomized from 16MB up to 1GB (9 bits
2128ed9f007eSKees Cook	  of entropy). Note that this also reduces the memory space
2129ed9f007eSKees Cook	  available to kernel modules from 1.5GB to 1GB.
2130ed9f007eSKees Cook
2131ed9f007eSKees Cook	  On 32-bit, the kernel physical and virtual addresses are
2132ed9f007eSKees Cook	  randomized together. They will be randomized from 16MB up to
2133ed9f007eSKees Cook	  512MB (8 bits of entropy).
21348ab3820fSKees Cook
2135a653f356SKees Cook	  Entropy is generated using the RDRAND instruction if it is
2136e8581e3dSBaoquan He	  supported. If RDTSC is supported, its value is mixed into
2137e8581e3dSBaoquan He	  the entropy pool as well. If neither RDRAND nor RDTSC are
2138ed9f007eSKees Cook	  supported, then entropy is read from the i8254 timer. The
2139ed9f007eSKees Cook	  usable entropy is limited by the kernel being built using
2140ed9f007eSKees Cook	  2GB addressing, and that PHYSICAL_ALIGN must be at a
2141ed9f007eSKees Cook	  minimum of 2MB. As a result, only 10 bits of entropy are
2142ed9f007eSKees Cook	  theoretically possible, but the implementations are further
2143ed9f007eSKees Cook	  limited due to memory layouts.
2144e8581e3dSBaoquan He
21456807c846SIngo Molnar	  If unsure, say Y.
2146da2b6fb9SKees Cook
21478ab3820fSKees Cook# Relocation on x86 needs some additional build support
2148845adf72SH. Peter Anvinconfig X86_NEED_RELOCS
2149845adf72SH. Peter Anvin	def_bool y
21508ab3820fSKees Cook	depends on RANDOMIZE_BASE || (X86_32 && RELOCATABLE)
2151845adf72SH. Peter Anvin
2152506f1d07SSam Ravnborgconfig PHYSICAL_ALIGN
2153a0215061SKees Cook	hex "Alignment value to which kernel should be aligned"
21548ab3820fSKees Cook	default "0x200000"
2155a0215061SKees Cook	range 0x2000 0x1000000 if X86_32
2156a0215061SKees Cook	range 0x200000 0x1000000 if X86_64
21578f9ca475SIngo Molnar	---help---
2158506f1d07SSam Ravnborg	  This value puts the alignment restrictions on physical address
2159506f1d07SSam Ravnborg	  where kernel is loaded and run from. Kernel is compiled for an
2160506f1d07SSam Ravnborg	  address which meets above alignment restriction.
2161506f1d07SSam Ravnborg
2162506f1d07SSam Ravnborg	  If bootloader loads the kernel at a non-aligned address and
2163506f1d07SSam Ravnborg	  CONFIG_RELOCATABLE is set, kernel will move itself to nearest
2164506f1d07SSam Ravnborg	  address aligned to above value and run from there.
2165506f1d07SSam Ravnborg
2166506f1d07SSam Ravnborg	  If bootloader loads the kernel at a non-aligned address and
2167506f1d07SSam Ravnborg	  CONFIG_RELOCATABLE is not set, kernel will ignore the run time
2168506f1d07SSam Ravnborg	  load address and decompress itself to the address it has been
2169506f1d07SSam Ravnborg	  compiled for and run from there. The address for which kernel is
2170506f1d07SSam Ravnborg	  compiled already meets above alignment restrictions. Hence the
2171506f1d07SSam Ravnborg	  end result is that kernel runs from a physical address meeting
2172506f1d07SSam Ravnborg	  above alignment restrictions.
2173506f1d07SSam Ravnborg
2174a0215061SKees Cook	  On 32-bit this value must be a multiple of 0x2000. On 64-bit
2175a0215061SKees Cook	  this value must be a multiple of 0x200000.
2176a0215061SKees Cook
2177506f1d07SSam Ravnborg	  Don't change this unless you know what you are doing.
2178506f1d07SSam Ravnborg
2179eedb92abSKirill A. Shutemovconfig DYNAMIC_MEMORY_LAYOUT
2180eedb92abSKirill A. Shutemov	bool
2181eedb92abSKirill A. Shutemov	---help---
2182eedb92abSKirill A. Shutemov	  This option makes base addresses of vmalloc and vmemmap as well as
2183eedb92abSKirill A. Shutemov	  __PAGE_OFFSET movable during boot.
2184eedb92abSKirill A. Shutemov
21850483e1faSThomas Garnierconfig RANDOMIZE_MEMORY
21860483e1faSThomas Garnier	bool "Randomize the kernel memory sections"
21870483e1faSThomas Garnier	depends on X86_64
21880483e1faSThomas Garnier	depends on RANDOMIZE_BASE
2189eedb92abSKirill A. Shutemov	select DYNAMIC_MEMORY_LAYOUT
21900483e1faSThomas Garnier	default RANDOMIZE_BASE
21910483e1faSThomas Garnier	---help---
21920483e1faSThomas Garnier	   Randomizes the base virtual address of kernel memory sections
21930483e1faSThomas Garnier	   (physical memory mapping, vmalloc & vmemmap). This security feature
21940483e1faSThomas Garnier	   makes exploits relying on predictable memory locations less reliable.
21950483e1faSThomas Garnier
21960483e1faSThomas Garnier	   The order of allocations remains unchanged. Entropy is generated in
21970483e1faSThomas Garnier	   the same way as RANDOMIZE_BASE. Current implementation in the optimal
21980483e1faSThomas Garnier	   configuration have in average 30,000 different possible virtual
21990483e1faSThomas Garnier	   addresses for each memory section.
22000483e1faSThomas Garnier
22016807c846SIngo Molnar	   If unsure, say Y.
22020483e1faSThomas Garnier
220390397a41SThomas Garnierconfig RANDOMIZE_MEMORY_PHYSICAL_PADDING
220490397a41SThomas Garnier	hex "Physical memory mapping padding" if EXPERT
220590397a41SThomas Garnier	depends on RANDOMIZE_MEMORY
220690397a41SThomas Garnier	default "0xa" if MEMORY_HOTPLUG
220790397a41SThomas Garnier	default "0x0"
220890397a41SThomas Garnier	range 0x1 0x40 if MEMORY_HOTPLUG
220990397a41SThomas Garnier	range 0x0 0x40
221090397a41SThomas Garnier	---help---
221190397a41SThomas Garnier	   Define the padding in terabytes added to the existing physical
221290397a41SThomas Garnier	   memory size during kernel memory randomization. It is useful
221390397a41SThomas Garnier	   for memory hotplug support but reduces the entropy available for
221490397a41SThomas Garnier	   address randomization.
221590397a41SThomas Garnier
221690397a41SThomas Garnier	   If unsure, leave at the default value.
221790397a41SThomas Garnier
2218506f1d07SSam Ravnborgconfig HOTPLUG_CPU
22197c13e6a3SDimitri Sivanich	bool "Support for hot-pluggable CPUs"
222040b31360SStephen Rothwell	depends on SMP
2221506f1d07SSam Ravnborg	---help---
22227c13e6a3SDimitri Sivanich	  Say Y here to allow turning CPUs off and on. CPUs can be
22237c13e6a3SDimitri Sivanich	  controlled through /sys/devices/system/cpu.
22247c13e6a3SDimitri Sivanich	  ( Note: power management support will enable this option
22257c13e6a3SDimitri Sivanich	    automatically on SMP systems. )
22267c13e6a3SDimitri Sivanich	  Say N if you want to disable CPU hotplug.
2227506f1d07SSam Ravnborg
222880aa1dffSFenghua Yuconfig BOOTPARAM_HOTPLUG_CPU0
222980aa1dffSFenghua Yu	bool "Set default setting of cpu0_hotpluggable"
223080aa1dffSFenghua Yu	default n
22312c922cd0SKees Cook	depends on HOTPLUG_CPU
223280aa1dffSFenghua Yu	---help---
223380aa1dffSFenghua Yu	  Set whether default state of cpu0_hotpluggable is on or off.
223480aa1dffSFenghua Yu
223580aa1dffSFenghua Yu	  Say Y here to enable CPU0 hotplug by default. If this switch
223680aa1dffSFenghua Yu	  is turned on, there is no need to give cpu0_hotplug kernel
223780aa1dffSFenghua Yu	  parameter and the CPU0 hotplug feature is enabled by default.
223880aa1dffSFenghua Yu
223980aa1dffSFenghua Yu	  Please note: there are two known CPU0 dependencies if you want
224080aa1dffSFenghua Yu	  to enable the CPU0 hotplug feature either by this switch or by
224180aa1dffSFenghua Yu	  cpu0_hotplug kernel parameter.
224280aa1dffSFenghua Yu
224380aa1dffSFenghua Yu	  First, resume from hibernate or suspend always starts from CPU0.
224480aa1dffSFenghua Yu	  So hibernate and suspend are prevented if CPU0 is offline.
224580aa1dffSFenghua Yu
224680aa1dffSFenghua Yu	  Second dependency is PIC interrupts always go to CPU0. CPU0 can not
224780aa1dffSFenghua Yu	  offline if any interrupt can not migrate out of CPU0. There may
224880aa1dffSFenghua Yu	  be other CPU0 dependencies.
224980aa1dffSFenghua Yu
225080aa1dffSFenghua Yu	  Please make sure the dependencies are under your control before
225180aa1dffSFenghua Yu	  you enable this feature.
225280aa1dffSFenghua Yu
225380aa1dffSFenghua Yu	  Say N if you don't want to enable CPU0 hotplug feature by default.
225480aa1dffSFenghua Yu	  You still can enable the CPU0 hotplug feature at boot by kernel
225580aa1dffSFenghua Yu	  parameter cpu0_hotplug.
225680aa1dffSFenghua Yu
2257a71c8bc5SFenghua Yuconfig DEBUG_HOTPLUG_CPU0
2258a71c8bc5SFenghua Yu	def_bool n
2259a71c8bc5SFenghua Yu	prompt "Debug CPU0 hotplug"
22602c922cd0SKees Cook	depends on HOTPLUG_CPU
2261a71c8bc5SFenghua Yu	---help---
2262a71c8bc5SFenghua Yu	  Enabling this option offlines CPU0 (if CPU0 can be offlined) as
2263a71c8bc5SFenghua Yu	  soon as possible and boots up userspace with CPU0 offlined. User
2264a71c8bc5SFenghua Yu	  can online CPU0 back after boot time.
2265a71c8bc5SFenghua Yu
2266a71c8bc5SFenghua Yu	  To debug CPU0 hotplug, you need to enable CPU0 offline/online
2267a71c8bc5SFenghua Yu	  feature by either turning on CONFIG_BOOTPARAM_HOTPLUG_CPU0 during
2268a71c8bc5SFenghua Yu	  compilation or giving cpu0_hotplug kernel parameter at boot.
2269a71c8bc5SFenghua Yu
2270a71c8bc5SFenghua Yu	  If unsure, say N.
2271a71c8bc5SFenghua Yu
2272506f1d07SSam Ravnborgconfig COMPAT_VDSO
2273b0b49f26SAndy Lutomirski	def_bool n
2274b0b49f26SAndy Lutomirski	prompt "Disable the 32-bit vDSO (needed for glibc 2.3.3)"
2275953fee1dSIngo Molnar	depends on COMPAT_32
22768f9ca475SIngo Molnar	---help---
2277b0b49f26SAndy Lutomirski	  Certain buggy versions of glibc will crash if they are
2278b0b49f26SAndy Lutomirski	  presented with a 32-bit vDSO that is not mapped at the address
2279b0b49f26SAndy Lutomirski	  indicated in its segment table.
2280e84446deSRandy Dunlap
2281b0b49f26SAndy Lutomirski	  The bug was introduced by f866314b89d56845f55e6f365e18b31ec978ec3a
2282b0b49f26SAndy Lutomirski	  and fixed by 3b3ddb4f7db98ec9e912ccdf54d35df4aa30e04a and
2283b0b49f26SAndy Lutomirski	  49ad572a70b8aeb91e57483a11dd1b77e31c4468.  Glibc 2.3.3 is
2284b0b49f26SAndy Lutomirski	  the only released version with the bug, but OpenSUSE 9
2285b0b49f26SAndy Lutomirski	  contains a buggy "glibc 2.3.2".
2286506f1d07SSam Ravnborg
2287b0b49f26SAndy Lutomirski	  The symptom of the bug is that everything crashes on startup, saying:
2288b0b49f26SAndy Lutomirski	  dl_main: Assertion `(void *) ph->p_vaddr == _rtld_local._dl_sysinfo_dso' failed!
2289b0b49f26SAndy Lutomirski
2290b0b49f26SAndy Lutomirski	  Saying Y here changes the default value of the vdso32 boot
2291b0b49f26SAndy Lutomirski	  option from 1 to 0, which turns off the 32-bit vDSO entirely.
2292b0b49f26SAndy Lutomirski	  This works around the glibc bug but hurts performance.
2293b0b49f26SAndy Lutomirski
2294b0b49f26SAndy Lutomirski	  If unsure, say N: if you are compiling your own kernel, you
2295b0b49f26SAndy Lutomirski	  are unlikely to be using a buggy version of glibc.
2296506f1d07SSam Ravnborg
22973dc33bd3SKees Cookchoice
22983dc33bd3SKees Cook	prompt "vsyscall table for legacy applications"
22993dc33bd3SKees Cook	depends on X86_64
23003dc33bd3SKees Cook	default LEGACY_VSYSCALL_EMULATE
23013dc33bd3SKees Cook	help
23023dc33bd3SKees Cook	  Legacy user code that does not know how to find the vDSO expects
23033dc33bd3SKees Cook	  to be able to issue three syscalls by calling fixed addresses in
23043dc33bd3SKees Cook	  kernel space. Since this location is not randomized with ASLR,
23053dc33bd3SKees Cook	  it can be used to assist security vulnerability exploitation.
23063dc33bd3SKees Cook
23073dc33bd3SKees Cook	  This setting can be changed at boot time via the kernel command
2308076ca272SAndy Lutomirski	  line parameter vsyscall=[emulate|none].
23093dc33bd3SKees Cook
23103dc33bd3SKees Cook	  On a system with recent enough glibc (2.14 or newer) and no
23113dc33bd3SKees Cook	  static binaries, you can say None without a performance penalty
23123dc33bd3SKees Cook	  to improve security.
23133dc33bd3SKees Cook
23143dc33bd3SKees Cook	  If unsure, select "Emulate".
23153dc33bd3SKees Cook
23163dc33bd3SKees Cook	config LEGACY_VSYSCALL_EMULATE
23173dc33bd3SKees Cook		bool "Emulate"
23183dc33bd3SKees Cook		help
23193dc33bd3SKees Cook		  The kernel traps and emulates calls into the fixed
23203dc33bd3SKees Cook		  vsyscall address mapping. This makes the mapping
23213dc33bd3SKees Cook		  non-executable, but it still contains known contents,
23223dc33bd3SKees Cook		  which could be used in certain rare security vulnerability
23233dc33bd3SKees Cook		  exploits. This configuration is recommended when userspace
23243dc33bd3SKees Cook		  still uses the vsyscall area.
23253dc33bd3SKees Cook
23263dc33bd3SKees Cook	config LEGACY_VSYSCALL_NONE
23273dc33bd3SKees Cook		bool "None"
23283dc33bd3SKees Cook		help
23293dc33bd3SKees Cook		  There will be no vsyscall mapping at all. This will
23303dc33bd3SKees Cook		  eliminate any risk of ASLR bypass due to the vsyscall
23313dc33bd3SKees Cook		  fixed address mapping. Attempts to use the vsyscalls
23323dc33bd3SKees Cook		  will be reported to dmesg, so that either old or
23333dc33bd3SKees Cook		  malicious userspace programs can be identified.
23343dc33bd3SKees Cook
23353dc33bd3SKees Cookendchoice
23363dc33bd3SKees Cook
2337516cbf37STim Birdconfig CMDLINE_BOOL
2338516cbf37STim Bird	bool "Built-in kernel command line"
23398f9ca475SIngo Molnar	---help---
2340516cbf37STim Bird	  Allow for specifying boot arguments to the kernel at
2341516cbf37STim Bird	  build time.  On some systems (e.g. embedded ones), it is
2342516cbf37STim Bird	  necessary or convenient to provide some or all of the
2343516cbf37STim Bird	  kernel boot arguments with the kernel itself (that is,
2344516cbf37STim Bird	  to not rely on the boot loader to provide them.)
2345516cbf37STim Bird
2346516cbf37STim Bird	  To compile command line arguments into the kernel,
2347516cbf37STim Bird	  set this option to 'Y', then fill in the
234869711ca1SSébastien Hinderer	  boot arguments in CONFIG_CMDLINE.
2349516cbf37STim Bird
2350516cbf37STim Bird	  Systems with fully functional boot loaders (i.e. non-embedded)
2351516cbf37STim Bird	  should leave this option set to 'N'.
2352516cbf37STim Bird
2353516cbf37STim Birdconfig CMDLINE
2354516cbf37STim Bird	string "Built-in kernel command string"
2355516cbf37STim Bird	depends on CMDLINE_BOOL
2356516cbf37STim Bird	default ""
23578f9ca475SIngo Molnar	---help---
2358516cbf37STim Bird	  Enter arguments here that should be compiled into the kernel
2359516cbf37STim Bird	  image and used at boot time.  If the boot loader provides a
2360516cbf37STim Bird	  command line at boot time, it is appended to this string to
2361516cbf37STim Bird	  form the full kernel command line, when the system boots.
2362516cbf37STim Bird
2363516cbf37STim Bird	  However, you can use the CONFIG_CMDLINE_OVERRIDE option to
2364516cbf37STim Bird	  change this behavior.
2365516cbf37STim Bird
2366516cbf37STim Bird	  In most cases, the command line (whether built-in or provided
2367516cbf37STim Bird	  by the boot loader) should specify the device for the root
2368516cbf37STim Bird	  file system.
2369516cbf37STim Bird
2370516cbf37STim Birdconfig CMDLINE_OVERRIDE
2371516cbf37STim Bird	bool "Built-in command line overrides boot loader arguments"
2372516cbf37STim Bird	depends on CMDLINE_BOOL
23738f9ca475SIngo Molnar	---help---
2374516cbf37STim Bird	  Set this option to 'Y' to have the kernel ignore the boot loader
2375516cbf37STim Bird	  command line, and use ONLY the built-in command line.
2376516cbf37STim Bird
2377516cbf37STim Bird	  This is used to work around broken boot loaders.  This should
2378516cbf37STim Bird	  be set to 'N' under normal conditions.
2379516cbf37STim Bird
2380a5b9e5a2SAndy Lutomirskiconfig MODIFY_LDT_SYSCALL
2381a5b9e5a2SAndy Lutomirski	bool "Enable the LDT (local descriptor table)" if EXPERT
2382a5b9e5a2SAndy Lutomirski	default y
2383a5b9e5a2SAndy Lutomirski	---help---
2384a5b9e5a2SAndy Lutomirski	  Linux can allow user programs to install a per-process x86
2385a5b9e5a2SAndy Lutomirski	  Local Descriptor Table (LDT) using the modify_ldt(2) system
2386a5b9e5a2SAndy Lutomirski	  call.  This is required to run 16-bit or segmented code such as
2387a5b9e5a2SAndy Lutomirski	  DOSEMU or some Wine programs.  It is also used by some very old
2388a5b9e5a2SAndy Lutomirski	  threading libraries.
2389a5b9e5a2SAndy Lutomirski
2390a5b9e5a2SAndy Lutomirski	  Enabling this feature adds a small amount of overhead to
2391a5b9e5a2SAndy Lutomirski	  context switches and increases the low-level kernel attack
2392a5b9e5a2SAndy Lutomirski	  surface.  Disabling it removes the modify_ldt(2) system call.
2393a5b9e5a2SAndy Lutomirski
2394a5b9e5a2SAndy Lutomirski	  Saying 'N' here may make sense for embedded or server kernels.
2395a5b9e5a2SAndy Lutomirski
2396b700e7f0SSeth Jenningssource "kernel/livepatch/Kconfig"
2397b700e7f0SSeth Jennings
2398506f1d07SSam Ravnborgendmenu
2399506f1d07SSam Ravnborg
24003072e413SMichal Hockoconfig ARCH_HAS_ADD_PAGES
24013072e413SMichal Hocko	def_bool y
24023072e413SMichal Hocko	depends on X86_64 && ARCH_ENABLE_MEMORY_HOTPLUG
24033072e413SMichal Hocko
2404506f1d07SSam Ravnborgconfig ARCH_ENABLE_MEMORY_HOTPLUG
2405506f1d07SSam Ravnborg	def_bool y
2406506f1d07SSam Ravnborg	depends on X86_64 || (X86_32 && HIGHMEM)
2407506f1d07SSam Ravnborg
240835551053SGary Hadeconfig ARCH_ENABLE_MEMORY_HOTREMOVE
240935551053SGary Hade	def_bool y
241035551053SGary Hade	depends on MEMORY_HOTPLUG
241135551053SGary Hade
2412e534c7c5SLee Schermerhornconfig USE_PERCPU_NUMA_NODE_ID
2413645a7919STejun Heo	def_bool y
2414e534c7c5SLee Schermerhorn	depends on NUMA
2415e534c7c5SLee Schermerhorn
24169491846fSKirill A. Shutemovconfig ARCH_ENABLE_SPLIT_PMD_PTLOCK
24179491846fSKirill A. Shutemov	def_bool y
24189491846fSKirill A. Shutemov	depends on X86_64 || X86_PAE
24199491846fSKirill A. Shutemov
2420c177c81eSNaoya Horiguchiconfig ARCH_ENABLE_HUGEPAGE_MIGRATION
2421c177c81eSNaoya Horiguchi	def_bool y
2422c177c81eSNaoya Horiguchi	depends on X86_64 && HUGETLB_PAGE && MIGRATION
2423c177c81eSNaoya Horiguchi
24249c670ea3SNaoya Horiguchiconfig ARCH_ENABLE_THP_MIGRATION
24259c670ea3SNaoya Horiguchi	def_bool y
24269c670ea3SNaoya Horiguchi	depends on X86_64 && TRANSPARENT_HUGEPAGE
24279c670ea3SNaoya Horiguchi
2428da85f865SBjorn Helgaasmenu "Power management and ACPI options"
2429e279b6c1SSam Ravnborg
2430e279b6c1SSam Ravnborgconfig ARCH_HIBERNATION_HEADER
24313c2362e6SHarvey Harrison	def_bool y
2432e279b6c1SSam Ravnborg	depends on X86_64 && HIBERNATION
2433e279b6c1SSam Ravnborg
2434e279b6c1SSam Ravnborgsource "kernel/power/Kconfig"
2435e279b6c1SSam Ravnborg
2436e279b6c1SSam Ravnborgsource "drivers/acpi/Kconfig"
2437e279b6c1SSam Ravnborg
2438efafc8b2SFeng Tangsource "drivers/sfi/Kconfig"
2439efafc8b2SFeng Tang
2440a6b68076SAndi Kleenconfig X86_APM_BOOT
24416fc108a0SJan Beulich	def_bool y
2442282e5aabSPaul Bolle	depends on APM
2443a6b68076SAndi Kleen
2444e279b6c1SSam Ravnborgmenuconfig APM
2445e279b6c1SSam Ravnborg	tristate "APM (Advanced Power Management) BIOS support"
2446efefa6f6SIngo Molnar	depends on X86_32 && PM_SLEEP
2447e279b6c1SSam Ravnborg	---help---
2448e279b6c1SSam Ravnborg	  APM is a BIOS specification for saving power using several different
2449e279b6c1SSam Ravnborg	  techniques. This is mostly useful for battery powered laptops with
2450e279b6c1SSam Ravnborg	  APM compliant BIOSes. If you say Y here, the system time will be
2451e279b6c1SSam Ravnborg	  reset after a RESUME operation, the /proc/apm device will provide
2452e279b6c1SSam Ravnborg	  battery status information, and user-space programs will receive
2453e279b6c1SSam Ravnborg	  notification of APM "events" (e.g. battery status change).
2454e279b6c1SSam Ravnborg
2455e279b6c1SSam Ravnborg	  If you select "Y" here, you can disable actual use of the APM
2456e279b6c1SSam Ravnborg	  BIOS by passing the "apm=off" option to the kernel at boot time.
2457e279b6c1SSam Ravnborg
2458e279b6c1SSam Ravnborg	  Note that the APM support is almost completely disabled for
2459e279b6c1SSam Ravnborg	  machines with more than one CPU.
2460e279b6c1SSam Ravnborg
2461e279b6c1SSam Ravnborg	  In order to use APM, you will need supporting software. For location
24622dc98fd3SMichael Witten	  and more information, read <file:Documentation/power/apm-acpi.txt>
24632dc98fd3SMichael Witten	  and the Battery Powered Linux mini-HOWTO, available from
2464e279b6c1SSam Ravnborg	  <http://www.tldp.org/docs.html#howto>.
2465e279b6c1SSam Ravnborg
2466e279b6c1SSam Ravnborg	  This driver does not spin down disk drives (see the hdparm(8)
2467e279b6c1SSam Ravnborg	  manpage ("man 8 hdparm") for that), and it doesn't turn off
2468e279b6c1SSam Ravnborg	  VESA-compliant "green" monitors.
2469e279b6c1SSam Ravnborg
2470e279b6c1SSam Ravnborg	  This driver does not support the TI 4000M TravelMate and the ACER
2471e279b6c1SSam Ravnborg	  486/DX4/75 because they don't have compliant BIOSes. Many "green"
2472e279b6c1SSam Ravnborg	  desktop machines also don't have compliant BIOSes, and this driver
2473e279b6c1SSam Ravnborg	  may cause those machines to panic during the boot phase.
2474e279b6c1SSam Ravnborg
2475e279b6c1SSam Ravnborg	  Generally, if you don't have a battery in your machine, there isn't
2476e279b6c1SSam Ravnborg	  much point in using this driver and you should say N. If you get
2477e279b6c1SSam Ravnborg	  random kernel OOPSes or reboots that don't seem to be related to
2478e279b6c1SSam Ravnborg	  anything, try disabling/enabling this option (or disabling/enabling
2479e279b6c1SSam Ravnborg	  APM in your BIOS).
2480e279b6c1SSam Ravnborg
2481e279b6c1SSam Ravnborg	  Some other things you should try when experiencing seemingly random,
2482e279b6c1SSam Ravnborg	  "weird" problems:
2483e279b6c1SSam Ravnborg
2484e279b6c1SSam Ravnborg	  1) make sure that you have enough swap space and that it is
2485e279b6c1SSam Ravnborg	  enabled.
2486e279b6c1SSam Ravnborg	  2) pass the "no-hlt" option to the kernel
2487e279b6c1SSam Ravnborg	  3) switch on floating point emulation in the kernel and pass
2488e279b6c1SSam Ravnborg	  the "no387" option to the kernel
2489e279b6c1SSam Ravnborg	  4) pass the "floppy=nodma" option to the kernel
2490e279b6c1SSam Ravnborg	  5) pass the "mem=4M" option to the kernel (thereby disabling
2491e279b6c1SSam Ravnborg	  all but the first 4 MB of RAM)
2492e279b6c1SSam Ravnborg	  6) make sure that the CPU is not over clocked.
2493e279b6c1SSam Ravnborg	  7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/>
2494e279b6c1SSam Ravnborg	  8) disable the cache from your BIOS settings
2495e279b6c1SSam Ravnborg	  9) install a fan for the video card or exchange video RAM
2496e279b6c1SSam Ravnborg	  10) install a better fan for the CPU
2497e279b6c1SSam Ravnborg	  11) exchange RAM chips
2498e279b6c1SSam Ravnborg	  12) exchange the motherboard.
2499e279b6c1SSam Ravnborg
2500e279b6c1SSam Ravnborg	  To compile this driver as a module, choose M here: the
2501e279b6c1SSam Ravnborg	  module will be called apm.
2502e279b6c1SSam Ravnborg
2503e279b6c1SSam Ravnborgif APM
2504e279b6c1SSam Ravnborg
2505e279b6c1SSam Ravnborgconfig APM_IGNORE_USER_SUSPEND
2506e279b6c1SSam Ravnborg	bool "Ignore USER SUSPEND"
25078f9ca475SIngo Molnar	---help---
2508e279b6c1SSam Ravnborg	  This option will ignore USER SUSPEND requests. On machines with a
2509e279b6c1SSam Ravnborg	  compliant APM BIOS, you want to say N. However, on the NEC Versa M
2510e279b6c1SSam Ravnborg	  series notebooks, it is necessary to say Y because of a BIOS bug.
2511e279b6c1SSam Ravnborg
2512e279b6c1SSam Ravnborgconfig APM_DO_ENABLE
2513e279b6c1SSam Ravnborg	bool "Enable PM at boot time"
2514e279b6c1SSam Ravnborg	---help---
2515e279b6c1SSam Ravnborg	  Enable APM features at boot time. From page 36 of the APM BIOS
2516e279b6c1SSam Ravnborg	  specification: "When disabled, the APM BIOS does not automatically
2517e279b6c1SSam Ravnborg	  power manage devices, enter the Standby State, enter the Suspend
2518e279b6c1SSam Ravnborg	  State, or take power saving steps in response to CPU Idle calls."
2519e279b6c1SSam Ravnborg	  This driver will make CPU Idle calls when Linux is idle (unless this
2520e279b6c1SSam Ravnborg	  feature is turned off -- see "Do CPU IDLE calls", below). This
2521e279b6c1SSam Ravnborg	  should always save battery power, but more complicated APM features
2522e279b6c1SSam Ravnborg	  will be dependent on your BIOS implementation. You may need to turn
2523e279b6c1SSam Ravnborg	  this option off if your computer hangs at boot time when using APM
2524e279b6c1SSam Ravnborg	  support, or if it beeps continuously instead of suspending. Turn
2525e279b6c1SSam Ravnborg	  this off if you have a NEC UltraLite Versa 33/C or a Toshiba
2526e279b6c1SSam Ravnborg	  T400CDT. This is off by default since most machines do fine without
2527e279b6c1SSam Ravnborg	  this feature.
2528e279b6c1SSam Ravnborg
2529e279b6c1SSam Ravnborgconfig APM_CPU_IDLE
2530dd8af076SLen Brown	depends on CPU_IDLE
2531e279b6c1SSam Ravnborg	bool "Make CPU Idle calls when idle"
25328f9ca475SIngo Molnar	---help---
2533e279b6c1SSam Ravnborg	  Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop.
2534e279b6c1SSam Ravnborg	  On some machines, this can activate improved power savings, such as
2535e279b6c1SSam Ravnborg	  a slowed CPU clock rate, when the machine is idle. These idle calls
2536e279b6c1SSam Ravnborg	  are made after the idle loop has run for some length of time (e.g.,
2537e279b6c1SSam Ravnborg	  333 mS). On some machines, this will cause a hang at boot time or
2538e279b6c1SSam Ravnborg	  whenever the CPU becomes idle. (On machines with more than one CPU,
2539e279b6c1SSam Ravnborg	  this option does nothing.)
2540e279b6c1SSam Ravnborg
2541e279b6c1SSam Ravnborgconfig APM_DISPLAY_BLANK
2542e279b6c1SSam Ravnborg	bool "Enable console blanking using APM"
25438f9ca475SIngo Molnar	---help---
2544e279b6c1SSam Ravnborg	  Enable console blanking using the APM. Some laptops can use this to
2545e279b6c1SSam Ravnborg	  turn off the LCD backlight when the screen blanker of the Linux
2546e279b6c1SSam Ravnborg	  virtual console blanks the screen. Note that this is only used by
2547e279b6c1SSam Ravnborg	  the virtual console screen blanker, and won't turn off the backlight
2548e279b6c1SSam Ravnborg	  when using the X Window system. This also doesn't have anything to
2549e279b6c1SSam Ravnborg	  do with your VESA-compliant power-saving monitor. Further, this
2550e279b6c1SSam Ravnborg	  option doesn't work for all laptops -- it might not turn off your
2551e279b6c1SSam Ravnborg	  backlight at all, or it might print a lot of errors to the console,
2552e279b6c1SSam Ravnborg	  especially if you are using gpm.
2553e279b6c1SSam Ravnborg
2554e279b6c1SSam Ravnborgconfig APM_ALLOW_INTS
2555e279b6c1SSam Ravnborg	bool "Allow interrupts during APM BIOS calls"
25568f9ca475SIngo Molnar	---help---
2557e279b6c1SSam Ravnborg	  Normally we disable external interrupts while we are making calls to
2558e279b6c1SSam Ravnborg	  the APM BIOS as a measure to lessen the effects of a badly behaving
2559e279b6c1SSam Ravnborg	  BIOS implementation.  The BIOS should reenable interrupts if it
2560e279b6c1SSam Ravnborg	  needs to.  Unfortunately, some BIOSes do not -- especially those in
2561e279b6c1SSam Ravnborg	  many of the newer IBM Thinkpads.  If you experience hangs when you
2562e279b6c1SSam Ravnborg	  suspend, try setting this to Y.  Otherwise, say N.
2563e279b6c1SSam Ravnborg
2564e279b6c1SSam Ravnborgendif # APM
2565e279b6c1SSam Ravnborg
2566bb0a56ecSDave Jonessource "drivers/cpufreq/Kconfig"
2567e279b6c1SSam Ravnborg
2568e279b6c1SSam Ravnborgsource "drivers/cpuidle/Kconfig"
2569e279b6c1SSam Ravnborg
257027471fdbSAndy Henroidsource "drivers/idle/Kconfig"
257127471fdbSAndy Henroid
2572e279b6c1SSam Ravnborgendmenu
2573e279b6c1SSam Ravnborg
2574e279b6c1SSam Ravnborg
2575e279b6c1SSam Ravnborgmenu "Bus options (PCI etc.)"
2576e279b6c1SSam Ravnborg
2577e279b6c1SSam Ravnborgconfig PCI
25781ac97018SIngo Molnar	bool "PCI support"
25791c858087SAdrian Bunk	default y
25808f9ca475SIngo Molnar	---help---
2581e279b6c1SSam Ravnborg	  Find out whether you have a PCI motherboard. PCI is the name of a
2582e279b6c1SSam Ravnborg	  bus system, i.e. the way the CPU talks to the other stuff inside
2583e279b6c1SSam Ravnborg	  your box. Other bus systems are ISA, EISA, MicroChannel (MCA) or
2584e279b6c1SSam Ravnborg	  VESA. If you have PCI, say Y, otherwise N.
2585e279b6c1SSam Ravnborg
2586e279b6c1SSam Ravnborgchoice
2587e279b6c1SSam Ravnborg	prompt "PCI access mode"
2588efefa6f6SIngo Molnar	depends on X86_32 && PCI
2589e279b6c1SSam Ravnborg	default PCI_GOANY
2590e279b6c1SSam Ravnborg	---help---
2591e279b6c1SSam Ravnborg	  On PCI systems, the BIOS can be used to detect the PCI devices and
2592e279b6c1SSam Ravnborg	  determine their configuration. However, some old PCI motherboards
2593e279b6c1SSam Ravnborg	  have BIOS bugs and may crash if this is done. Also, some embedded
2594e279b6c1SSam Ravnborg	  PCI-based systems don't have any BIOS at all. Linux can also try to
2595e279b6c1SSam Ravnborg	  detect the PCI hardware directly without using the BIOS.
2596e279b6c1SSam Ravnborg
2597e279b6c1SSam Ravnborg	  With this option, you can specify how Linux should detect the
2598e279b6c1SSam Ravnborg	  PCI devices. If you choose "BIOS", the BIOS will be used,
2599e279b6c1SSam Ravnborg	  if you choose "Direct", the BIOS won't be used, and if you
2600e279b6c1SSam Ravnborg	  choose "MMConfig", then PCI Express MMCONFIG will be used.
2601e279b6c1SSam Ravnborg	  If you choose "Any", the kernel will try MMCONFIG, then the
2602e279b6c1SSam Ravnborg	  direct access method and falls back to the BIOS if that doesn't
2603e279b6c1SSam Ravnborg	  work. If unsure, go with the default, which is "Any".
2604e279b6c1SSam Ravnborg
2605e279b6c1SSam Ravnborgconfig PCI_GOBIOS
2606e279b6c1SSam Ravnborg	bool "BIOS"
2607e279b6c1SSam Ravnborg
2608e279b6c1SSam Ravnborgconfig PCI_GOMMCONFIG
2609e279b6c1SSam Ravnborg	bool "MMConfig"
2610e279b6c1SSam Ravnborg
2611e279b6c1SSam Ravnborgconfig PCI_GODIRECT
2612e279b6c1SSam Ravnborg	bool "Direct"
2613e279b6c1SSam Ravnborg
26143ef0e1f8SAndres Salomonconfig PCI_GOOLPC
261576fb6570SDaniel Drake	bool "OLPC XO-1"
26163ef0e1f8SAndres Salomon	depends on OLPC
26173ef0e1f8SAndres Salomon
26182bdd1b03SAndres Salomonconfig PCI_GOANY
26192bdd1b03SAndres Salomon	bool "Any"
26202bdd1b03SAndres Salomon
2621e279b6c1SSam Ravnborgendchoice
2622e279b6c1SSam Ravnborg
2623e279b6c1SSam Ravnborgconfig PCI_BIOS
26243c2362e6SHarvey Harrison	def_bool y
2625efefa6f6SIngo Molnar	depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY)
2626e279b6c1SSam Ravnborg
2627e279b6c1SSam Ravnborg# x86-64 doesn't support PCI BIOS access from long mode so always go direct.
2628e279b6c1SSam Ravnborgconfig PCI_DIRECT
26293c2362e6SHarvey Harrison	def_bool y
26300aba496fSShaohua Li	depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC || PCI_GOMMCONFIG))
2631e279b6c1SSam Ravnborg
2632e279b6c1SSam Ravnborgconfig PCI_MMCONFIG
2633b45c9f36SJan Kiszka	bool "Support mmconfig PCI config space access" if X86_64
2634b45c9f36SJan Kiszka	default y
26358364e1f8SJan Kiszka	depends on PCI && (ACPI || SFI || JAILHOUSE_GUEST)
2636b45c9f36SJan Kiszka	depends on X86_64 || (PCI_GOANY || PCI_GOMMCONFIG)
2637e279b6c1SSam Ravnborg
26383ef0e1f8SAndres Salomonconfig PCI_OLPC
26392bdd1b03SAndres Salomon	def_bool y
26402bdd1b03SAndres Salomon	depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY)
26413ef0e1f8SAndres Salomon
2642b5401a96SAlex Nixonconfig PCI_XEN
2643b5401a96SAlex Nixon	def_bool y
2644b5401a96SAlex Nixon	depends on PCI && XEN
2645b5401a96SAlex Nixon	select SWIOTLB_XEN
2646b5401a96SAlex Nixon
2647e279b6c1SSam Ravnborgconfig PCI_DOMAINS
26483c2362e6SHarvey Harrison	def_bool y
2649e279b6c1SSam Ravnborg	depends on PCI
2650e279b6c1SSam Ravnborg
26518364e1f8SJan Kiszkaconfig MMCONF_FAM10H
26528364e1f8SJan Kiszka	def_bool y
26538364e1f8SJan Kiszka	depends on X86_64 && PCI_MMCONFIG && ACPI
2654e279b6c1SSam Ravnborg
26553f6ea84aSIra W. Snyderconfig PCI_CNB20LE_QUIRK
26566a108a14SDavid Rientjes	bool "Read CNB20LE Host Bridge Windows" if EXPERT
26576ea30386SKees Cook	depends on PCI
26583f6ea84aSIra W. Snyder	help
26593f6ea84aSIra W. Snyder	  Read the PCI windows out of the CNB20LE host bridge. This allows
26603f6ea84aSIra W. Snyder	  PCI hotplug to work on systems with the CNB20LE chipset which do
26613f6ea84aSIra W. Snyder	  not have ACPI.
26623f6ea84aSIra W. Snyder
266364a5fed6SBjorn Helgaas	  There's no public spec for this chipset, and this functionality
266464a5fed6SBjorn Helgaas	  is known to be incomplete.
266564a5fed6SBjorn Helgaas
266664a5fed6SBjorn Helgaas	  You should say N unless you know you need this.
266764a5fed6SBjorn Helgaas
2668e279b6c1SSam Ravnborgsource "drivers/pci/Kconfig"
2669e279b6c1SSam Ravnborg
26703a495511SWilliam Breathitt Grayconfig ISA_BUS
267117a2a129SWilliam Breathitt Gray	bool "ISA bus support on modern systems" if EXPERT
26723a495511SWilliam Breathitt Gray	help
267317a2a129SWilliam Breathitt Gray	  Expose ISA bus device drivers and options available for selection and
267417a2a129SWilliam Breathitt Gray	  configuration. Enable this option if your target machine has an ISA
267517a2a129SWilliam Breathitt Gray	  bus. ISA is an older system, displaced by PCI and newer bus
267617a2a129SWilliam Breathitt Gray	  architectures -- if your target machine is modern, it probably does
267717a2a129SWilliam Breathitt Gray	  not have an ISA bus.
26783a495511SWilliam Breathitt Gray
26793a495511SWilliam Breathitt Gray	  If unsure, say N.
26803a495511SWilliam Breathitt Gray
26811c00f016SDavid Rientjes# x86_64 have no ISA slots, but can have ISA-style DMA.
2682e279b6c1SSam Ravnborgconfig ISA_DMA_API
26831c00f016SDavid Rientjes	bool "ISA-style DMA support" if (X86_64 && EXPERT)
26841c00f016SDavid Rientjes	default y
26851c00f016SDavid Rientjes	help
26861c00f016SDavid Rientjes	  Enables ISA-style DMA support for devices requiring such controllers.
26871c00f016SDavid Rientjes	  If unsure, say Y.
2688e279b6c1SSam Ravnborg
268951e68d05SLinus Torvaldsif X86_32
269051e68d05SLinus Torvalds
2691e279b6c1SSam Ravnborgconfig ISA
2692e279b6c1SSam Ravnborg	bool "ISA support"
26938f9ca475SIngo Molnar	---help---
2694e279b6c1SSam Ravnborg	  Find out whether you have ISA slots on your motherboard.  ISA is the
2695e279b6c1SSam Ravnborg	  name of a bus system, i.e. the way the CPU talks to the other stuff
2696e279b6c1SSam Ravnborg	  inside your box.  Other bus systems are PCI, EISA, MicroChannel
2697e279b6c1SSam Ravnborg	  (MCA) or VESA.  ISA is an older system, now being displaced by PCI;
2698e279b6c1SSam Ravnborg	  newer boards don't support it.  If you have ISA, say Y, otherwise N.
2699e279b6c1SSam Ravnborg
2700e279b6c1SSam Ravnborgconfig EISA
2701e279b6c1SSam Ravnborg	bool "EISA support"
2702e279b6c1SSam Ravnborg	depends on ISA
2703e279b6c1SSam Ravnborg	---help---
2704e279b6c1SSam Ravnborg	  The Extended Industry Standard Architecture (EISA) bus was
2705e279b6c1SSam Ravnborg	  developed as an open alternative to the IBM MicroChannel bus.
2706e279b6c1SSam Ravnborg
2707e279b6c1SSam Ravnborg	  The EISA bus provided some of the features of the IBM MicroChannel
2708e279b6c1SSam Ravnborg	  bus while maintaining backward compatibility with cards made for
2709e279b6c1SSam Ravnborg	  the older ISA bus.  The EISA bus saw limited use between 1988 and
2710e279b6c1SSam Ravnborg	  1995 when it was made obsolete by the PCI bus.
2711e279b6c1SSam Ravnborg
2712e279b6c1SSam Ravnborg	  Say Y here if you are building a kernel for an EISA-based machine.
2713e279b6c1SSam Ravnborg
2714e279b6c1SSam Ravnborg	  Otherwise, say N.
2715e279b6c1SSam Ravnborg
2716e279b6c1SSam Ravnborgsource "drivers/eisa/Kconfig"
2717e279b6c1SSam Ravnborg
2718e279b6c1SSam Ravnborgconfig SCx200
2719e279b6c1SSam Ravnborg	tristate "NatSemi SCx200 support"
27208f9ca475SIngo Molnar	---help---
2721e279b6c1SSam Ravnborg	  This provides basic support for National Semiconductor's
2722e279b6c1SSam Ravnborg	  (now AMD's) Geode processors.  The driver probes for the
2723e279b6c1SSam Ravnborg	  PCI-IDs of several on-chip devices, so its a good dependency
2724e279b6c1SSam Ravnborg	  for other scx200_* drivers.
2725e279b6c1SSam Ravnborg
2726e279b6c1SSam Ravnborg	  If compiled as a module, the driver is named scx200.
2727e279b6c1SSam Ravnborg
2728e279b6c1SSam Ravnborgconfig SCx200HR_TIMER
2729e279b6c1SSam Ravnborg	tristate "NatSemi SCx200 27MHz High-Resolution Timer Support"
2730592913ecSJohn Stultz	depends on SCx200
2731e279b6c1SSam Ravnborg	default y
27328f9ca475SIngo Molnar	---help---
2733e279b6c1SSam Ravnborg	  This driver provides a clocksource built upon the on-chip
2734e279b6c1SSam Ravnborg	  27MHz high-resolution timer.  Its also a workaround for
2735e279b6c1SSam Ravnborg	  NSC Geode SC-1100's buggy TSC, which loses time when the
2736e279b6c1SSam Ravnborg	  processor goes idle (as is done by the scheduler).  The
2737e279b6c1SSam Ravnborg	  other workaround is idle=poll boot option.
2738e279b6c1SSam Ravnborg
27393ef0e1f8SAndres Salomonconfig OLPC
27403ef0e1f8SAndres Salomon	bool "One Laptop Per Child support"
274154008979SThomas Gleixner	depends on !X86_PAE
27423c554946SAndres Salomon	select GPIOLIB
2743dc3119e7SThomas Gleixner	select OF
274445bb1674SDaniel Drake	select OF_PROMTREE
2745b4e51854SGrant Likely	select IRQ_DOMAIN
27468f9ca475SIngo Molnar	---help---
27473ef0e1f8SAndres Salomon	  Add support for detecting the unique features of the OLPC
27483ef0e1f8SAndres Salomon	  XO hardware.
27493ef0e1f8SAndres Salomon
2750a3128588SDaniel Drakeconfig OLPC_XO1_PM
2751a3128588SDaniel Drake	bool "OLPC XO-1 Power Management"
275297c4cb71SDaniel Drake	depends on OLPC && MFD_CS5535 && PM_SLEEP
2753a3128588SDaniel Drake	select MFD_CORE
2754bf1ebf00SDaniel Drake	---help---
275597c4cb71SDaniel Drake	  Add support for poweroff and suspend of the OLPC XO-1 laptop.
2756bf1ebf00SDaniel Drake
2757cfee9597SDaniel Drakeconfig OLPC_XO1_RTC
2758cfee9597SDaniel Drake	bool "OLPC XO-1 Real Time Clock"
2759cfee9597SDaniel Drake	depends on OLPC_XO1_PM && RTC_DRV_CMOS
2760cfee9597SDaniel Drake	---help---
2761cfee9597SDaniel Drake	  Add support for the XO-1 real time clock, which can be used as a
2762cfee9597SDaniel Drake	  programmable wakeup source.
2763cfee9597SDaniel Drake
27647feda8e9SDaniel Drakeconfig OLPC_XO1_SCI
27657feda8e9SDaniel Drake	bool "OLPC XO-1 SCI extras"
276692e830f2SArnd Bergmann	depends on OLPC && OLPC_XO1_PM && GPIO_CS5535=y
2767ed8e47feSRandy Dunlap	depends on INPUT=y
2768d8d01a63SDaniel Drake	select POWER_SUPPLY
27697feda8e9SDaniel Drake	---help---
27707feda8e9SDaniel Drake	  Add support for SCI-based features of the OLPC XO-1 laptop:
27717bc74b3dSDaniel Drake	   - EC-driven system wakeups
27727feda8e9SDaniel Drake	   - Power button
27737bc74b3dSDaniel Drake	   - Ebook switch
27742cf2baeaSDaniel Drake	   - Lid switch
2775e1040ac6SDaniel Drake	   - AC adapter status updates
2776e1040ac6SDaniel Drake	   - Battery status updates
27777feda8e9SDaniel Drake
2778a0f30f59SDaniel Drakeconfig OLPC_XO15_SCI
2779a0f30f59SDaniel Drake	bool "OLPC XO-1.5 SCI extras"
2780d8d01a63SDaniel Drake	depends on OLPC && ACPI
2781d8d01a63SDaniel Drake	select POWER_SUPPLY
2782a0f30f59SDaniel Drake	---help---
2783a0f30f59SDaniel Drake	  Add support for SCI-based features of the OLPC XO-1.5 laptop:
2784a0f30f59SDaniel Drake	   - EC-driven system wakeups
2785a0f30f59SDaniel Drake	   - AC adapter status updates
2786a0f30f59SDaniel Drake	   - Battery status updates
2787e279b6c1SSam Ravnborg
2788d4f3e350SEd Wildgooseconfig ALIX
2789d4f3e350SEd Wildgoose	bool "PCEngines ALIX System Support (LED setup)"
2790d4f3e350SEd Wildgoose	select GPIOLIB
2791d4f3e350SEd Wildgoose	---help---
2792d4f3e350SEd Wildgoose	  This option enables system support for the PCEngines ALIX.
2793d4f3e350SEd Wildgoose	  At present this just sets up LEDs for GPIO control on
2794d4f3e350SEd Wildgoose	  ALIX2/3/6 boards.  However, other system specific setup should
2795d4f3e350SEd Wildgoose	  get added here.
2796d4f3e350SEd Wildgoose
2797d4f3e350SEd Wildgoose	  Note: You must still enable the drivers for GPIO and LED support
2798d4f3e350SEd Wildgoose	  (GPIO_CS5535 & LEDS_GPIO) to actually use the LEDs
2799d4f3e350SEd Wildgoose
2800d4f3e350SEd Wildgoose	  Note: You have to set alix.force=1 for boards with Award BIOS.
2801d4f3e350SEd Wildgoose
2802da4e3302SPhilip Prindevilleconfig NET5501
2803da4e3302SPhilip Prindeville	bool "Soekris Engineering net5501 System Support (LEDS, GPIO, etc)"
2804da4e3302SPhilip Prindeville	select GPIOLIB
2805da4e3302SPhilip Prindeville	---help---
2806da4e3302SPhilip Prindeville	  This option enables system support for the Soekris Engineering net5501.
2807da4e3302SPhilip Prindeville
28083197059aSPhilip A. Prindevilleconfig GEOS
28093197059aSPhilip A. Prindeville	bool "Traverse Technologies GEOS System Support (LEDS, GPIO, etc)"
28103197059aSPhilip A. Prindeville	select GPIOLIB
28113197059aSPhilip A. Prindeville	depends on DMI
28123197059aSPhilip A. Prindeville	---help---
28133197059aSPhilip A. Prindeville	  This option enables system support for the Traverse Technologies GEOS.
28143197059aSPhilip A. Prindeville
28157d029125SVivien Didelotconfig TS5500
28167d029125SVivien Didelot	bool "Technologic Systems TS-5500 platform support"
28177d029125SVivien Didelot	depends on MELAN
28187d029125SVivien Didelot	select CHECK_SIGNATURE
28197d029125SVivien Didelot	select NEW_LEDS
28207d029125SVivien Didelot	select LEDS_CLASS
28217d029125SVivien Didelot	---help---
28227d029125SVivien Didelot	  This option enables system support for the Technologic Systems TS-5500.
28237d029125SVivien Didelot
2824e279b6c1SSam Ravnborgendif # X86_32
2825e279b6c1SSam Ravnborg
282623ac4ae8SAndreas Herrmannconfig AMD_NB
2827e279b6c1SSam Ravnborg	def_bool y
28280e152cd7SBorislav Petkov	depends on CPU_SUP_AMD && PCI
2829e279b6c1SSam Ravnborg
2830e279b6c1SSam Ravnborgsource "drivers/pcmcia/Kconfig"
2831e279b6c1SSam Ravnborg
2832388b78adSAlexandre Bounineconfig RAPIDIO
2833fdf90abcSAlexandre Bounine	tristate "RapidIO support"
2834388b78adSAlexandre Bounine	depends on PCI
2835388b78adSAlexandre Bounine	default n
2836388b78adSAlexandre Bounine	help
2837fdf90abcSAlexandre Bounine	  If enabled this option will include drivers and the core
2838388b78adSAlexandre Bounine	  infrastructure code to support RapidIO interconnect devices.
2839388b78adSAlexandre Bounine
2840388b78adSAlexandre Bouninesource "drivers/rapidio/Kconfig"
2841388b78adSAlexandre Bounine
2842e3263ab3SDavid Herrmannconfig X86_SYSFB
2843e3263ab3SDavid Herrmann	bool "Mark VGA/VBE/EFI FB as generic system framebuffer"
2844e3263ab3SDavid Herrmann	help
2845e3263ab3SDavid Herrmann	  Firmwares often provide initial graphics framebuffers so the BIOS,
2846e3263ab3SDavid Herrmann	  bootloader or kernel can show basic video-output during boot for
2847e3263ab3SDavid Herrmann	  user-guidance and debugging. Historically, x86 used the VESA BIOS
2848e3263ab3SDavid Herrmann	  Extensions and EFI-framebuffers for this, which are mostly limited
2849e3263ab3SDavid Herrmann	  to x86.
2850e3263ab3SDavid Herrmann	  This option, if enabled, marks VGA/VBE/EFI framebuffers as generic
2851e3263ab3SDavid Herrmann	  framebuffers so the new generic system-framebuffer drivers can be
2852e3263ab3SDavid Herrmann	  used on x86. If the framebuffer is not compatible with the generic
2853e3263ab3SDavid Herrmann	  modes, it is adverticed as fallback platform framebuffer so legacy
2854e3263ab3SDavid Herrmann	  drivers like efifb, vesafb and uvesafb can pick it up.
2855e3263ab3SDavid Herrmann	  If this option is not selected, all system framebuffers are always
2856e3263ab3SDavid Herrmann	  marked as fallback platform framebuffers as usual.
2857e3263ab3SDavid Herrmann
2858e3263ab3SDavid Herrmann	  Note: Legacy fbdev drivers, including vesafb, efifb, uvesafb, will
2859e3263ab3SDavid Herrmann	  not be able to pick up generic system framebuffers if this option
2860e3263ab3SDavid Herrmann	  is selected. You are highly encouraged to enable simplefb as
2861e3263ab3SDavid Herrmann	  replacement if you select this option. simplefb can correctly deal
2862e3263ab3SDavid Herrmann	  with generic system framebuffers. But you should still keep vesafb
2863e3263ab3SDavid Herrmann	  and others enabled as fallback if a system framebuffer is
2864e3263ab3SDavid Herrmann	  incompatible with simplefb.
2865e3263ab3SDavid Herrmann
2866e3263ab3SDavid Herrmann	  If unsure, say Y.
2867e3263ab3SDavid Herrmann
2868e279b6c1SSam Ravnborgendmenu
2869e279b6c1SSam Ravnborg
2870e279b6c1SSam Ravnborg
2871e279b6c1SSam Ravnborgmenu "Executable file formats / Emulations"
2872e279b6c1SSam Ravnborg
2873e279b6c1SSam Ravnborgsource "fs/Kconfig.binfmt"
2874e279b6c1SSam Ravnborg
2875e279b6c1SSam Ravnborgconfig IA32_EMULATION
2876e279b6c1SSam Ravnborg	bool "IA32 Emulation"
2877e279b6c1SSam Ravnborg	depends on X86_64
287839f88911SIngo Molnar	select ARCH_WANT_OLD_COMPAT_IPC
2879d1603990SRandy Dunlap	select BINFMT_ELF
2880a97f52e6SRoland McGrath	select COMPAT_BINFMT_ELF
288139f88911SIngo Molnar	select COMPAT_OLD_SIGACTION
28828f9ca475SIngo Molnar	---help---
28835fd92e65SH. J. Lu	  Include code to run legacy 32-bit programs under a
28845fd92e65SH. J. Lu	  64-bit kernel. You should likely turn this on, unless you're
28855fd92e65SH. J. Lu	  100% sure that you don't have any 32-bit programs left.
2886e279b6c1SSam Ravnborg
2887e279b6c1SSam Ravnborgconfig IA32_AOUT
2888e279b6c1SSam Ravnborg	tristate "IA32 a.out support"
28896b213e1bSDavid Woodhouse	depends on IA32_EMULATION
28908f9ca475SIngo Molnar	---help---
2891e279b6c1SSam Ravnborg	  Support old a.out binaries in the 32bit emulation.
2892e279b6c1SSam Ravnborg
28930bf62763SH. Peter Anvinconfig X86_X32
28946ea30386SKees Cook	bool "x32 ABI for 64-bit mode"
28959b54050bSBrian Gerst	depends on X86_64
28965fd92e65SH. J. Lu	---help---
28975fd92e65SH. J. Lu	  Include code to run binaries for the x32 native 32-bit ABI
28985fd92e65SH. J. Lu	  for 64-bit processors.  An x32 process gets access to the
28995fd92e65SH. J. Lu	  full 64-bit register file and wide data path while leaving
29005fd92e65SH. J. Lu	  pointers at 32 bits for smaller memory footprint.
29015fd92e65SH. J. Lu
29025fd92e65SH. J. Lu	  You will need a recent binutils (2.22 or later) with
29035fd92e65SH. J. Lu	  elf32_x86_64 support enabled to compile a kernel with this
29045fd92e65SH. J. Lu	  option set.
29055fd92e65SH. J. Lu
2906953fee1dSIngo Molnarconfig COMPAT_32
2907953fee1dSIngo Molnar	def_bool y
2908953fee1dSIngo Molnar	depends on IA32_EMULATION || X86_32
2909953fee1dSIngo Molnar	select HAVE_UID16
2910953fee1dSIngo Molnar	select OLD_SIGSUSPEND3
2911953fee1dSIngo Molnar
2912e279b6c1SSam Ravnborgconfig COMPAT
29133c2362e6SHarvey Harrison	def_bool y
29140bf62763SH. Peter Anvin	depends on IA32_EMULATION || X86_X32
2915e279b6c1SSam Ravnborg
29163120e25eSJan Beulichif COMPAT
2917e279b6c1SSam Ravnborgconfig COMPAT_FOR_U64_ALIGNMENT
29183120e25eSJan Beulich	def_bool y
2919e279b6c1SSam Ravnborg
2920e279b6c1SSam Ravnborgconfig SYSVIPC_COMPAT
29213c2362e6SHarvey Harrison	def_bool y
29223120e25eSJan Beulich	depends on SYSVIPC
29233120e25eSJan Beulichendif
2924ee009e4aSDavid Howells
2925e279b6c1SSam Ravnborgendmenu
2926e279b6c1SSam Ravnborg
2927e279b6c1SSam Ravnborg
2928e5beae16SKeith Packardconfig HAVE_ATOMIC_IOMAP
2929e5beae16SKeith Packard	def_bool y
2930e5beae16SKeith Packard	depends on X86_32
2931e5beae16SKeith Packard
29324692d77fSAlessandro Rubiniconfig X86_DEV_DMA_OPS
29334692d77fSAlessandro Rubini	bool
293483125a3aSAlessandro Rubini	depends on X86_64 || STA2X11
29354692d77fSAlessandro Rubini
2936f7219a53SAlessandro Rubiniconfig X86_DMA_REMAP
2937f7219a53SAlessandro Rubini	bool
293883125a3aSAlessandro Rubini	depends on STA2X11
2939f7219a53SAlessandro Rubini
2940e585513bSKirill A. Shutemovconfig HAVE_GENERIC_GUP
2941e585513bSKirill A. Shutemov	def_bool y
2942e585513bSKirill A. Shutemov
2943e279b6c1SSam Ravnborgsource "net/Kconfig"
2944e279b6c1SSam Ravnborg
2945e279b6c1SSam Ravnborgsource "drivers/Kconfig"
2946e279b6c1SSam Ravnborg
2947e279b6c1SSam Ravnborgsource "drivers/firmware/Kconfig"
2948e279b6c1SSam Ravnborg
2949e279b6c1SSam Ravnborgsource "fs/Kconfig"
2950e279b6c1SSam Ravnborg
2951e279b6c1SSam Ravnborgsource "arch/x86/Kconfig.debug"
2952e279b6c1SSam Ravnborg
2953e279b6c1SSam Ravnborgsource "security/Kconfig"
2954e279b6c1SSam Ravnborg
2955e279b6c1SSam Ravnborgsource "crypto/Kconfig"
2956e279b6c1SSam Ravnborg
2957edf88417SAvi Kivitysource "arch/x86/kvm/Kconfig"
2958edf88417SAvi Kivity
2959e279b6c1SSam Ravnborgsource "lib/Kconfig"
2960