xref: /linux/arch/x86/Kconfig (revision 6ad57f7f2cbf65daced27f023cc99360742a24b9)
1b2441318SGreg Kroah-Hartman# SPDX-License-Identifier: GPL-2.0
2daa93fabSSam Ravnborg# Select 32 or 64 bit
3daa93fabSSam Ravnborgconfig 64BIT
4104daea1SMasahiro Yamada	bool "64-bit kernel" if "$(ARCH)" = "x86"
5104daea1SMasahiro Yamada	default "$(ARCH)" != "i386"
68f9ca475SIngo Molnar	---help---
7daa93fabSSam Ravnborg	  Say yes to build a 64-bit kernel - formerly known as x86_64
8daa93fabSSam Ravnborg	  Say no to build a 32-bit kernel - formerly known as i386
9daa93fabSSam Ravnborg
10daa93fabSSam Ravnborgconfig X86_32
113120e25eSJan Beulich	def_bool y
123120e25eSJan Beulich	depends on !64BIT
13341c787eSIngo Molnar	# Options that are inherently 32-bit kernel only:
14341c787eSIngo Molnar	select ARCH_WANT_IPC_PARSE_VERSION
15341c787eSIngo Molnar	select CLKSRC_I8253
16341c787eSIngo Molnar	select CLONE_BACKWARDS
17341c787eSIngo Molnar	select MODULES_USE_ELF_REL
18341c787eSIngo Molnar	select OLD_SIGACTION
19daa93fabSSam Ravnborg
20daa93fabSSam Ravnborgconfig X86_64
213120e25eSJan Beulich	def_bool y
223120e25eSJan Beulich	depends on 64BIT
23d94e0685SIngo Molnar	# Options that are inherently 64-bit kernel only:
24e1073d1eSAneesh Kumar K.V	select ARCH_HAS_GIGANTIC_PAGE if (MEMORY_ISOLATION && COMPACTION) || CMA
25d94e0685SIngo Molnar	select ARCH_SUPPORTS_INT128
26d94e0685SIngo Molnar	select ARCH_USE_CMPXCHG_LOCKREF
27d94e0685SIngo Molnar	select HAVE_ARCH_SOFT_DIRTY
28d94e0685SIngo Molnar	select MODULES_USE_ELF_RELA
29f616ab59SChristoph Hellwig	select NEED_DMA_MAP_STATE
3009230cbcSChristoph Hellwig	select SWIOTLB
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
48942fa985SYury Norov	select ARCH_32BIT_OFF_T			if X86_32
496471b825SIngo Molnar	select ARCH_CLOCKSOURCE_DATA
502a21ad57SThomas Gleixner	select ARCH_CLOCKSOURCE_INIT
516471b825SIngo Molnar	select ARCH_DISCARD_MEMBLOCK
5291dda51aSAleksey Makarov	select ARCH_HAS_ACPI_TABLE_UPGRADE	if ACPI
53fa5b6ec9SLaura Abbott	select ARCH_HAS_DEBUG_VIRTUAL
5421266be9SDan Williams	select ARCH_HAS_DEVMEM_IS_ALLOWED
556471b825SIngo Molnar	select ARCH_HAS_ELF_RANDOMIZE
5672d93104SLinus Torvalds	select ARCH_HAS_FAST_MULTIPLIER
57316d097cSDave Hansen	select ARCH_HAS_FILTER_PGPROT
586974f0c4SDaniel Micay	select ARCH_HAS_FORTIFY_SOURCE
59957e3facSRiku Voipio	select ARCH_HAS_GCOV_PROFILE_ALL
605c9a8750SDmitry Vyukov	select ARCH_HAS_KCOV			if X86_64
6110bcc80eSMathieu Desnoyers	select ARCH_HAS_MEMBARRIER_SYNC_CORE
62c763ea26SIngo Molnar	select ARCH_HAS_PMEM_API		if X86_64
633010a5eaSLaurent Dufour	select ARCH_HAS_PTE_SPECIAL
6439208aa7SKees Cook	select ARCH_HAS_REFCOUNT
650aed55afSDan Williams	select ARCH_HAS_UACCESS_FLUSHCACHE	if X86_64
66092b31aaSDan Williams	select ARCH_HAS_UACCESS_MCSAFE		if X86_64 && X86_MCE
67d2852a22SDaniel Borkmann	select ARCH_HAS_SET_MEMORY
68ad21fc4fSLaura Abbott	select ARCH_HAS_STRICT_KERNEL_RWX
69ad21fc4fSLaura Abbott	select ARCH_HAS_STRICT_MODULE_RWX
70ac1ab12aSMathieu Desnoyers	select ARCH_HAS_SYNC_CORE_BEFORE_USERMODE
71c6d30853SAndrey Ryabinin	select ARCH_HAS_UBSAN_SANITIZE_ALL
7265f7d049SOliver O'Halloran	select ARCH_HAS_ZONE_DEVICE		if X86_64
736471b825SIngo Molnar	select ARCH_HAVE_NMI_SAFE_CMPXCHG
746471b825SIngo Molnar	select ARCH_MIGHT_HAVE_ACPI_PDC		if ACPI
7577fbbc81SMark Salter	select ARCH_MIGHT_HAVE_PC_PARPORT
765e2c18c0SMark Salter	select ARCH_MIGHT_HAVE_PC_SERIO
772c870e61SArnd Bergmann	select ARCH_SUPPORTS_ACPI
786471b825SIngo Molnar	select ARCH_SUPPORTS_ATOMIC_RMW
796471b825SIngo Molnar	select ARCH_SUPPORTS_NUMA_BALANCING	if X86_64
806471b825SIngo Molnar	select ARCH_USE_BUILTIN_BSWAP
816471b825SIngo Molnar	select ARCH_USE_QUEUED_RWLOCKS
826471b825SIngo Molnar	select ARCH_USE_QUEUED_SPINLOCKS
83ce4a4e56SAndy Lutomirski	select ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH
84c763ea26SIngo Molnar	select ARCH_WANTS_DYNAMIC_TASK_STRUCT
8538d8b4e6SHuang Ying	select ARCH_WANTS_THP_SWAP		if X86_64
866471b825SIngo Molnar	select BUILDTIME_EXTABLE_SORT
876471b825SIngo Molnar	select CLKEVT_I8253
886471b825SIngo Molnar	select CLOCKSOURCE_VALIDATE_LAST_CYCLE
896471b825SIngo Molnar	select CLOCKSOURCE_WATCHDOG
906471b825SIngo Molnar	select DCACHE_WORD_ACCESS
9145471cd9SLinus Torvalds	select EDAC_ATOMIC_SCRUB
9245471cd9SLinus Torvalds	select EDAC_SUPPORT
936471b825SIngo Molnar	select GENERIC_CLOCKEVENTS
946471b825SIngo Molnar	select GENERIC_CLOCKEVENTS_BROADCAST	if X86_64 || (X86_32 && X86_LOCAL_APIC)
956471b825SIngo Molnar	select GENERIC_CLOCKEVENTS_MIN_ADJUST
966471b825SIngo Molnar	select GENERIC_CMOS_UPDATE
976471b825SIngo Molnar	select GENERIC_CPU_AUTOPROBE
9861dc0f55SThomas Gleixner	select GENERIC_CPU_VULNERABILITIES
996471b825SIngo Molnar	select GENERIC_EARLY_IOREMAP
1006471b825SIngo Molnar	select GENERIC_FIND_FIRST_BIT
1016471b825SIngo Molnar	select GENERIC_IOMAP
102c7d6c9ddSThomas Gleixner	select GENERIC_IRQ_EFFECTIVE_AFF_MASK	if SMP
1030fa115daSThomas Gleixner	select GENERIC_IRQ_MATRIX_ALLOCATOR	if X86_LOCAL_APIC
104ad7a929fSThomas Gleixner	select GENERIC_IRQ_MIGRATION		if SMP
1056471b825SIngo Molnar	select GENERIC_IRQ_PROBE
106c201c917SThomas Gleixner	select GENERIC_IRQ_RESERVATION_MODE
1076471b825SIngo Molnar	select GENERIC_IRQ_SHOW
1086471b825SIngo Molnar	select GENERIC_PENDING_IRQ		if SMP
1096471b825SIngo Molnar	select GENERIC_SMP_IDLE_THREAD
1106471b825SIngo Molnar	select GENERIC_STRNCPY_FROM_USER
1116471b825SIngo Molnar	select GENERIC_STRNLEN_USER
1126471b825SIngo Molnar	select GENERIC_TIME_VSYSCALL
1137edaeb68SThomas Gleixner	select HARDLOCKUP_CHECK_TIMESTAMP	if X86_64
1146471b825SIngo Molnar	select HAVE_ACPI_APEI			if ACPI
1156471b825SIngo Molnar	select HAVE_ACPI_APEI_NMI		if ACPI
1166471b825SIngo Molnar	select HAVE_ALIGNED_STRUCT_PAGE		if SLUB
1176471b825SIngo Molnar	select HAVE_ARCH_AUDITSYSCALL
1186471b825SIngo Molnar	select HAVE_ARCH_HUGE_VMAP		if X86_64 || X86_PAE
1196471b825SIngo Molnar	select HAVE_ARCH_JUMP_LABEL
120b34006c4SArd Biesheuvel	select HAVE_ARCH_JUMP_LABEL_RELATIVE
121d17a1d97SAndrey Ryabinin	select HAVE_ARCH_KASAN			if X86_64
1226471b825SIngo Molnar	select HAVE_ARCH_KGDB
1239e08f57dSDaniel Cashman	select HAVE_ARCH_MMAP_RND_BITS		if MMU
1249e08f57dSDaniel Cashman	select HAVE_ARCH_MMAP_RND_COMPAT_BITS	if MMU && COMPAT
1251b028f78SDmitry Safonov	select HAVE_ARCH_COMPAT_MMAP_BASES	if MMU && COMPAT
126271ca788SArd Biesheuvel	select HAVE_ARCH_PREL32_RELOCATIONS
1276471b825SIngo Molnar	select HAVE_ARCH_SECCOMP_FILTER
128f7d83c1cSKees Cook	select HAVE_ARCH_THREAD_STRUCT_WHITELIST
129afaef01cSAlexander Popov	select HAVE_ARCH_STACKLEAK
1306471b825SIngo Molnar	select HAVE_ARCH_TRACEHOOK
1316471b825SIngo Molnar	select HAVE_ARCH_TRANSPARENT_HUGEPAGE
132a00cc7d9SMatthew Wilcox	select HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD if X86_64
133e37e43a4SAndy Lutomirski	select HAVE_ARCH_VMAP_STACK		if X86_64
134c763ea26SIngo Molnar	select HAVE_ARCH_WITHIN_STACK_FRAMES
1356471b825SIngo Molnar	select HAVE_CMPXCHG_DOUBLE
1366471b825SIngo Molnar	select HAVE_CMPXCHG_LOCAL
1376471b825SIngo Molnar	select HAVE_CONTEXT_TRACKING		if X86_64
138c1bd55f9SJosh Triplett	select HAVE_COPY_THREAD_TLS
1396471b825SIngo Molnar	select HAVE_C_RECORDMCOUNT
1406471b825SIngo Molnar	select HAVE_DEBUG_KMEMLEAK
1416471b825SIngo Molnar	select HAVE_DEBUG_STACKOVERFLOW
1429c5a3621SAkinobu Mita	select HAVE_DMA_CONTIGUOUS
143677aa9f7SSteven Rostedt	select HAVE_DYNAMIC_FTRACE
14406aeaaeaSMasami Hiramatsu	select HAVE_DYNAMIC_FTRACE_WITH_REGS
14503f5781bSWang YanQing	select HAVE_EBPF_JIT
14658340a07SJohannes Berg	select HAVE_EFFICIENT_UNALIGNED_ACCESS
1476630a8e5SChristoph Hellwig	select HAVE_EISA
1485f56a5dfSJiri Slaby	select HAVE_EXIT_THREAD
149644e0e8dSSteven Rostedt (VMware)	select HAVE_FENTRY			if X86_64 || DYNAMIC_FTRACE
1506471b825SIngo Molnar	select HAVE_FTRACE_MCOUNT_RECORD
1516471b825SIngo Molnar	select HAVE_FUNCTION_GRAPH_TRACER
1526471b825SIngo Molnar	select HAVE_FUNCTION_TRACER
1536b90bd4bSEmese Revfy	select HAVE_GCC_PLUGINS
1540067f129SK.Prasad	select HAVE_HW_BREAKPOINT
1556471b825SIngo Molnar	select HAVE_IDE
1566471b825SIngo Molnar	select HAVE_IOREMAP_PROT
1576471b825SIngo Molnar	select HAVE_IRQ_EXIT_ON_IRQ_STACK	if X86_64
1586471b825SIngo Molnar	select HAVE_IRQ_TIME_ACCOUNTING
1596471b825SIngo Molnar	select HAVE_KERNEL_BZIP2
1606471b825SIngo Molnar	select HAVE_KERNEL_GZIP
1616471b825SIngo Molnar	select HAVE_KERNEL_LZ4
1626471b825SIngo Molnar	select HAVE_KERNEL_LZMA
1636471b825SIngo Molnar	select HAVE_KERNEL_LZO
1646471b825SIngo Molnar	select HAVE_KERNEL_XZ
1656471b825SIngo Molnar	select HAVE_KPROBES
1666471b825SIngo Molnar	select HAVE_KPROBES_ON_FTRACE
167540adea3SMasami Hiramatsu	select HAVE_FUNCTION_ERROR_INJECTION
1686471b825SIngo Molnar	select HAVE_KRETPROBES
1696471b825SIngo Molnar	select HAVE_KVM
1706471b825SIngo Molnar	select HAVE_LIVEPATCH			if X86_64
1716471b825SIngo Molnar	select HAVE_MEMBLOCK_NODE_MAP
1720102752eSFrederic Weisbecker	select HAVE_MIXED_BREAKPOINTS_REGS
173ee9f8fceSJosh Poimboeuf	select HAVE_MOD_ARCH_SPECIFIC
1749f132f7eSJoel Fernandes (Google)	select HAVE_MOVE_PMD
17542a0bb3fSPetr Mladek	select HAVE_NMI
1766471b825SIngo Molnar	select HAVE_OPROFILE
1776471b825SIngo Molnar	select HAVE_OPTPROBES
1786471b825SIngo Molnar	select HAVE_PCSPKR_PLATFORM
1796471b825SIngo Molnar	select HAVE_PERF_EVENTS
180c01d4323SFrederic Weisbecker	select HAVE_PERF_EVENTS_NMI
18192e5aae4SNicholas Piggin	select HAVE_HARDLOCKUP_DETECTOR_PERF	if PERF_EVENTS && HAVE_PERF_EVENTS_NMI
182eb01d42aSChristoph Hellwig	select HAVE_PCI
183c5e63197SJiri Olsa	select HAVE_PERF_REGS
184c5ebcedbSJiri Olsa	select HAVE_PERF_USER_STACK_DUMP
18548a8b97cSPeter Zijlstra	select HAVE_RCU_TABLE_FREE		if PARAVIRT
186d86564a2SPeter Zijlstra	select HAVE_RCU_TABLE_INVALIDATE	if HAVE_RCU_TABLE_FREE
1876471b825SIngo Molnar	select HAVE_REGS_AND_STACK_ACCESS_API
1886415b38bSJiri Slaby	select HAVE_RELIABLE_STACKTRACE		if X86_64 && (UNWINDER_FRAME_POINTER || UNWINDER_ORC) && STACK_VALIDATION
1893c88ee19SMasami Hiramatsu	select HAVE_FUNCTION_ARG_ACCESS_API
190d148eac0SMasahiro Yamada	select HAVE_STACKPROTECTOR		if CC_HAS_SANE_STACKPROTECTOR
191c763ea26SIngo Molnar	select HAVE_STACK_VALIDATION		if X86_64
192d6761b8fSMathieu Desnoyers	select HAVE_RSEQ
1936471b825SIngo Molnar	select HAVE_SYSCALL_TRACEPOINTS
1946471b825SIngo Molnar	select HAVE_UNSTABLE_SCHED_CLOCK
1957c68af6eSAvi Kivity	select HAVE_USER_RETURN_NOTIFIER
19605736e4aSThomas Gleixner	select HOTPLUG_SMT			if SMP
197c0185808SThomas Gleixner	select IRQ_FORCED_THREADING
19886596f0aSChristoph Hellwig	select NEED_SG_DMA_LENGTH
1992eac9c2dSChristoph Hellwig	select PCI_DOMAINS			if PCI
200625210cfSSinan Kaya	select PCI_LOCKLESS_CONFIG		if PCI
2016471b825SIngo Molnar	select PERF_EVENTS
2023195ef59SPrarit Bhargava	select RTC_LIB
203d6faca40SArnd Bergmann	select RTC_MC146818_LIB
2046471b825SIngo Molnar	select SPARSE_IRQ
20583fe27eaSPranith Kumar	select SRCU
2066471b825SIngo Molnar	select SYSCTL_EXCEPTION_TRACE
20715f4eae7SAndy Lutomirski	select THREAD_INFO_IN_TASK
2086471b825SIngo Molnar	select USER_STACKTRACE_SUPPORT
2096471b825SIngo Molnar	select VIRT_TO_BUS
2106471b825SIngo Molnar	select X86_FEATURE_NAMES		if PROC_FS
2117d8330a5SBalbir Singh
212ba7e4d13SIngo Molnarconfig INSTRUCTION_DECODER
2133120e25eSJan Beulich	def_bool y
2143120e25eSJan Beulich	depends on KPROBES || PERF_EVENTS || UPROBES
215ba7e4d13SIngo Molnar
21651b26adaSLinus Torvaldsconfig OUTPUT_FORMAT
21751b26adaSLinus Torvalds	string
21851b26adaSLinus Torvalds	default "elf32-i386" if X86_32
21951b26adaSLinus Torvalds	default "elf64-x86-64" if X86_64
22051b26adaSLinus Torvalds
22173531905SSam Ravnborgconfig ARCH_DEFCONFIG
222b9b39bfbSSam Ravnborg	string
22373531905SSam Ravnborg	default "arch/x86/configs/i386_defconfig" if X86_32
22473531905SSam Ravnborg	default "arch/x86/configs/x86_64_defconfig" if X86_64
225b9b39bfbSSam Ravnborg
2268d5fffb9SSam Ravnborgconfig LOCKDEP_SUPPORT
2273c2362e6SHarvey Harrison	def_bool y
2288d5fffb9SSam Ravnborg
2298d5fffb9SSam Ravnborgconfig STACKTRACE_SUPPORT
2303c2362e6SHarvey Harrison	def_bool y
2318d5fffb9SSam Ravnborg
2328d5fffb9SSam Ravnborgconfig MMU
2333c2362e6SHarvey Harrison	def_bool y
2348d5fffb9SSam Ravnborg
2359e08f57dSDaniel Cashmanconfig ARCH_MMAP_RND_BITS_MIN
2369e08f57dSDaniel Cashman	default 28 if 64BIT
2379e08f57dSDaniel Cashman	default 8
2389e08f57dSDaniel Cashman
2399e08f57dSDaniel Cashmanconfig ARCH_MMAP_RND_BITS_MAX
2409e08f57dSDaniel Cashman	default 32 if 64BIT
2419e08f57dSDaniel Cashman	default 16
2429e08f57dSDaniel Cashman
2439e08f57dSDaniel Cashmanconfig ARCH_MMAP_RND_COMPAT_BITS_MIN
2449e08f57dSDaniel Cashman	default 8
2459e08f57dSDaniel Cashman
2469e08f57dSDaniel Cashmanconfig ARCH_MMAP_RND_COMPAT_BITS_MAX
2479e08f57dSDaniel Cashman	default 16
2489e08f57dSDaniel Cashman
2498d5fffb9SSam Ravnborgconfig SBUS
2508d5fffb9SSam Ravnborg	bool
2518d5fffb9SSam Ravnborg
2528d5fffb9SSam Ravnborgconfig GENERIC_ISA_DMA
2533120e25eSJan Beulich	def_bool y
2543120e25eSJan Beulich	depends on ISA_DMA_API
2558d5fffb9SSam Ravnborg
2568d5fffb9SSam Ravnborgconfig GENERIC_BUG
2573c2362e6SHarvey Harrison	def_bool y
2588d5fffb9SSam Ravnborg	depends on BUG
259b93a531eSJan Beulich	select GENERIC_BUG_RELATIVE_POINTERS if X86_64
260b93a531eSJan Beulich
261b93a531eSJan Beulichconfig GENERIC_BUG_RELATIVE_POINTERS
262b93a531eSJan Beulich	bool
2638d5fffb9SSam Ravnborg
2648d5fffb9SSam Ravnborgconfig GENERIC_HWEIGHT
2653c2362e6SHarvey Harrison	def_bool y
2668d5fffb9SSam Ravnborg
2678d5fffb9SSam Ravnborgconfig ARCH_MAY_HAVE_PC_FDC
2683120e25eSJan Beulich	def_bool y
2693120e25eSJan Beulich	depends on ISA_DMA_API
2708d5fffb9SSam Ravnborg
2711032c0baSSam Ravnborgconfig RWSEM_XCHGADD_ALGORITHM
2723120e25eSJan Beulich	def_bool y
2731032c0baSSam Ravnborg
2741032c0baSSam Ravnborgconfig GENERIC_CALIBRATE_DELAY
2751032c0baSSam Ravnborg	def_bool y
2761032c0baSSam Ravnborg
2779a0b8415Svenkatesh.pallipadi@intel.comconfig ARCH_HAS_CPU_RELAX
2789a0b8415Svenkatesh.pallipadi@intel.com	def_bool y
2798d5fffb9SSam Ravnborg
2801b27d05bSPekka Enbergconfig ARCH_HAS_CACHE_LINE_SIZE
2811b27d05bSPekka Enberg	def_bool y
2821b27d05bSPekka Enberg
283316d097cSDave Hansenconfig ARCH_HAS_FILTER_PGPROT
284316d097cSDave Hansen	def_bool y
285316d097cSDave Hansen
286dd5af90aSMike Travisconfig HAVE_SETUP_PER_CPU_AREA
28789c9c4c5SBrian Gerst	def_bool y
288b32ef636Stravis@sgi.com
28908fc4580STejun Heoconfig NEED_PER_CPU_EMBED_FIRST_CHUNK
29008fc4580STejun Heo	def_bool y
29108fc4580STejun Heo
29208fc4580STejun Heoconfig NEED_PER_CPU_PAGE_FIRST_CHUNK
29311124411STejun Heo	def_bool y
29411124411STejun Heo
295801e4062SJohannes Bergconfig ARCH_HIBERNATION_POSSIBLE
296801e4062SJohannes Berg	def_bool y
297801e4062SJohannes Berg
298f4cb5700SJohannes Bergconfig ARCH_SUSPEND_POSSIBLE
299f4cb5700SJohannes Berg	def_bool y
300f4cb5700SJohannes Berg
301cfe28c5dSSteve Capperconfig ARCH_WANT_HUGE_PMD_SHARE
302cfe28c5dSSteve Capper	def_bool y
303cfe28c5dSSteve Capper
30453313b2cSSteve Capperconfig ARCH_WANT_GENERAL_HUGETLB
30553313b2cSSteve Capper	def_bool y
30653313b2cSSteve Capper
3078d5fffb9SSam Ravnborgconfig ZONE_DMA32
308e0fd24a3SJan Beulich	def_bool y if X86_64
3098d5fffb9SSam Ravnborg
3108d5fffb9SSam Ravnborgconfig AUDIT_ARCH
311e0fd24a3SJan Beulich	def_bool y if X86_64
3128d5fffb9SSam Ravnborg
313765c68bdSIngo Molnarconfig ARCH_SUPPORTS_OPTIMIZED_INLINING
314765c68bdSIngo Molnar	def_bool y
315765c68bdSIngo Molnar
3166a11f75bSAkinobu Mitaconfig ARCH_SUPPORTS_DEBUG_PAGEALLOC
3176a11f75bSAkinobu Mita	def_bool y
3186a11f75bSAkinobu Mita
319d6f2d75aSAndrey Ryabininconfig KASAN_SHADOW_OFFSET
320d6f2d75aSAndrey Ryabinin	hex
321d6f2d75aSAndrey Ryabinin	depends on KASAN
322d6f2d75aSAndrey Ryabinin	default 0xdffffc0000000000
323d6f2d75aSAndrey Ryabinin
32469575d38SShane Wangconfig HAVE_INTEL_TXT
32569575d38SShane Wang	def_bool y
3266ea30386SKees Cook	depends on INTEL_IOMMU && ACPI
32769575d38SShane Wang
3286b0c3d44SSam Ravnborgconfig X86_32_SMP
3296b0c3d44SSam Ravnborg	def_bool y
3306b0c3d44SSam Ravnborg	depends on X86_32 && SMP
3316b0c3d44SSam Ravnborg
3326b0c3d44SSam Ravnborgconfig X86_64_SMP
3336b0c3d44SSam Ravnborg	def_bool y
3346b0c3d44SSam Ravnborg	depends on X86_64 && SMP
3356b0c3d44SSam Ravnborg
336ccbeed3aSTejun Heoconfig X86_32_LAZY_GS
337ccbeed3aSTejun Heo	def_bool y
3388458f8c2SMasahiro Yamada	depends on X86_32 && !STACKPROTECTOR
339ccbeed3aSTejun Heo
3402b144498SSrikar Dronamrajuconfig ARCH_SUPPORTS_UPROBES
3412b144498SSrikar Dronamraju	def_bool y
3422b144498SSrikar Dronamraju
343d20642f0SRob Herringconfig FIX_EARLYCON_MEM
344d20642f0SRob Herring	def_bool y
345d20642f0SRob Herring
34694d49eb3SKirill A. Shutemovconfig DYNAMIC_PHYSICAL_MASK
34794d49eb3SKirill A. Shutemov	bool
34894d49eb3SKirill A. Shutemov
34998233368SKirill A. Shutemovconfig PGTABLE_LEVELS
35098233368SKirill A. Shutemov	int
35177ef56e4SKirill A. Shutemov	default 5 if X86_5LEVEL
35298233368SKirill A. Shutemov	default 4 if X86_64
35398233368SKirill A. Shutemov	default 3 if X86_PAE
35498233368SKirill A. Shutemov	default 2
35598233368SKirill A. Shutemov
3562a61f474SMasahiro Yamadaconfig CC_HAS_SANE_STACKPROTECTOR
3572a61f474SMasahiro Yamada	bool
3582a61f474SMasahiro Yamada	default $(success,$(srctree)/scripts/gcc-x86_64-has-stack-protector.sh $(CC)) if 64BIT
3592a61f474SMasahiro Yamada	default $(success,$(srctree)/scripts/gcc-x86_32-has-stack-protector.sh $(CC))
3602a61f474SMasahiro Yamada	help
3612a61f474SMasahiro Yamada	   We have to make sure stack protector is unconditionally disabled if
3622a61f474SMasahiro Yamada	   the compiler produces broken code.
3632a61f474SMasahiro Yamada
364506f1d07SSam Ravnborgmenu "Processor type and features"
365506f1d07SSam Ravnborg
3665ee71535SRandy Dunlapconfig ZONE_DMA
3675ee71535SRandy Dunlap	bool "DMA memory allocation support" if EXPERT
3685ee71535SRandy Dunlap	default y
3695ee71535SRandy Dunlap	help
3705ee71535SRandy Dunlap	  DMA memory allocation support allows devices with less than 32-bit
3715ee71535SRandy Dunlap	  addressing to allocate within the first 16MB of address space.
3725ee71535SRandy Dunlap	  Disable if no such devices will be used.
3735ee71535SRandy Dunlap
3745ee71535SRandy Dunlap	  If unsure, say Y.
3755ee71535SRandy Dunlap
376506f1d07SSam Ravnborgconfig SMP
377506f1d07SSam Ravnborg	bool "Symmetric multi-processing support"
378506f1d07SSam Ravnborg	---help---
379506f1d07SSam Ravnborg	  This enables support for systems with more than one CPU. If you have
3804a474157SRobert Graffham	  a system with only one CPU, say N. If you have a system with more
3814a474157SRobert Graffham	  than one CPU, say Y.
382506f1d07SSam Ravnborg
3834a474157SRobert Graffham	  If you say N here, the kernel will run on uni- and multiprocessor
384506f1d07SSam Ravnborg	  machines, but will use only one CPU of a multiprocessor machine. If
385506f1d07SSam Ravnborg	  you say Y here, the kernel will run on many, but not all,
3864a474157SRobert Graffham	  uniprocessor machines. On a uniprocessor machine, the kernel
387506f1d07SSam Ravnborg	  will run faster if you say N here.
388506f1d07SSam Ravnborg
389506f1d07SSam Ravnborg	  Note that if you say Y here and choose architecture "586" or
390506f1d07SSam Ravnborg	  "Pentium" under "Processor family", the kernel will not work on 486
391506f1d07SSam Ravnborg	  architectures. Similarly, multiprocessor kernels for the "PPro"
392506f1d07SSam Ravnborg	  architecture may not work on all Pentium based boards.
393506f1d07SSam Ravnborg
394506f1d07SSam Ravnborg	  People using multiprocessor machines who say Y here should also say
395506f1d07SSam Ravnborg	  Y to "Enhanced Real Time Clock Support", below. The "Advanced Power
396506f1d07SSam Ravnborg	  Management" code will be disabled if you say Y here.
397506f1d07SSam Ravnborg
398395cf969SPaul Bolle	  See also <file:Documentation/x86/i386/IO-APIC.txt>,
399c9525a3fSBenjamin Peterson	  <file:Documentation/lockup-watchdogs.txt> and the SMP-HOWTO available at
400506f1d07SSam Ravnborg	  <http://www.tldp.org/docs.html#howto>.
401506f1d07SSam Ravnborg
402506f1d07SSam Ravnborg	  If you don't know what to do here, say N.
403506f1d07SSam Ravnborg
4049def39beSJosh Triplettconfig X86_FEATURE_NAMES
4059def39beSJosh Triplett	bool "Processor feature human-readable names" if EMBEDDED
4069def39beSJosh Triplett	default y
4079def39beSJosh Triplett	---help---
4089def39beSJosh Triplett	  This option compiles in a table of x86 feature bits and corresponding
4099def39beSJosh Triplett	  names.  This is required to support /proc/cpuinfo and a few kernel
4109def39beSJosh Triplett	  messages.  You can disable this to save space, at the expense of
4119def39beSJosh Triplett	  making those few kernel messages show numeric feature bits instead.
4129def39beSJosh Triplett
4139def39beSJosh Triplett	  If in doubt, say Y.
4149def39beSJosh Triplett
41506cd9a7dSYinghai Luconfig X86_X2APIC
41606cd9a7dSYinghai Lu	bool "Support x2apic"
41719e3d60dSJan Kiszka	depends on X86_LOCAL_APIC && X86_64 && (IRQ_REMAP || HYPERVISOR_GUEST)
41806cd9a7dSYinghai Lu	---help---
41906cd9a7dSYinghai Lu	  This enables x2apic support on CPUs that have this feature.
42006cd9a7dSYinghai Lu
42106cd9a7dSYinghai Lu	  This allows 32-bit apic IDs (so it can support very large systems),
42206cd9a7dSYinghai Lu	  and accesses the local apic via MSRs not via mmio.
42306cd9a7dSYinghai Lu
42406cd9a7dSYinghai Lu	  If you don't know what to do here, say N.
42506cd9a7dSYinghai Lu
4266695c85bSYinghai Luconfig X86_MPPARSE
4276e87f9b7SBin Gao	bool "Enable MPS table" if ACPI || SFI
4287a527688SJan Beulich	default y
4295ab74722SIngo Molnar	depends on X86_LOCAL_APIC
4308f9ca475SIngo Molnar	---help---
4316695c85bSYinghai Lu	  For old smp systems that do not have proper acpi support. Newer systems
4326695c85bSYinghai Lu	  (esp with 64bit cpus) with acpi support, MADT and DSDT will override it
4336695c85bSYinghai Lu
434ddd70cf9SJun Nakajimaconfig GOLDFISH
435ddd70cf9SJun Nakajima       def_bool y
436ddd70cf9SJun Nakajima       depends on X86_GOLDFISH
437ddd70cf9SJun Nakajima
43876b04384SDavid Woodhouseconfig RETPOLINE
43976b04384SDavid Woodhouse	bool "Avoid speculative indirect branches in kernel"
44076b04384SDavid Woodhouse	default y
441d5028ba8SPeter Zijlstra	select STACK_VALIDATION if HAVE_STACK_VALIDATION
44276b04384SDavid Woodhouse	help
44376b04384SDavid Woodhouse	  Compile kernel with the retpoline compiler options to guard against
44476b04384SDavid Woodhouse	  kernel-to-user data leaks by avoiding speculative indirect
44576b04384SDavid Woodhouse	  branches. Requires a compiler with -mindirect-branch=thunk-extern
44676b04384SDavid Woodhouse	  support for full protection. The kernel may run slower.
44776b04384SDavid Woodhouse
448e6d42931SJohannes Weinerconfig X86_CPU_RESCTRL
449e6d42931SJohannes Weiner	bool "x86 CPU resource control support"
4506fe07ce3SBabu Moger	depends on X86 && (CPU_SUP_INTEL || CPU_SUP_AMD)
45159fe5a77SThomas Gleixner	select KERNFS
45278e99b4aSFenghua Yu	help
453e6d42931SJohannes Weiner	  Enable x86 CPU resource control support.
4546fe07ce3SBabu Moger
4556fe07ce3SBabu Moger	  Provide support for the allocation and monitoring of system resources
4566fe07ce3SBabu Moger	  usage by the CPU.
4576fe07ce3SBabu Moger
4586fe07ce3SBabu Moger	  Intel calls this Intel Resource Director Technology
4596fe07ce3SBabu Moger	  (Intel(R) RDT). More information about RDT can be found in the
4606fe07ce3SBabu Moger	  Intel x86 Architecture Software Developer Manual.
4616fe07ce3SBabu Moger
4626fe07ce3SBabu Moger	  AMD calls this AMD Platform Quality of Service (AMD QoS).
4636fe07ce3SBabu Moger	  More information about AMD QoS can be found in the AMD64 Technology
4646fe07ce3SBabu Moger	  Platform Quality of Service Extensions manual.
46578e99b4aSFenghua Yu
46678e99b4aSFenghua Yu	  Say N if unsure.
46778e99b4aSFenghua Yu
4688425091fSRavikiran G Thirumalaiif X86_32
469a0d0bb4dSRandy Dunlapconfig X86_BIGSMP
470a0d0bb4dSRandy Dunlap	bool "Support for big SMP systems with more than 8 CPUs"
471a0d0bb4dSRandy Dunlap	depends on SMP
472a0d0bb4dSRandy Dunlap	---help---
473a0d0bb4dSRandy Dunlap	  This option is needed for the systems that have more than 8 CPUs
474a0d0bb4dSRandy Dunlap
475c5c606d9SRavikiran G Thirumalaiconfig X86_EXTENDED_PLATFORM
476c5c606d9SRavikiran G Thirumalai	bool "Support for extended (non-PC) x86 platforms"
477c5c606d9SRavikiran G Thirumalai	default y
4788f9ca475SIngo Molnar	---help---
47906ac8346SIngo Molnar	  If you disable this option then the kernel will only support
48006ac8346SIngo Molnar	  standard PC platforms. (which covers the vast majority of
48106ac8346SIngo Molnar	  systems out there.)
48206ac8346SIngo Molnar
4838425091fSRavikiran G Thirumalai	  If you enable this option then you'll be able to select support
4848425091fSRavikiran G Thirumalai	  for the following (non-PC) 32 bit x86 platforms:
485cb7b8023SBen Hutchings		Goldfish (Android emulator)
4868425091fSRavikiran G Thirumalai		AMD Elan
4878425091fSRavikiran G Thirumalai		RDC R-321x SoC
4888425091fSRavikiran G Thirumalai		SGI 320/540 (Visual Workstation)
48983125a3aSAlessandro Rubini		STA2X11-based (e.g. Northville)
4903f4110a4SThomas Gleixner		Moorestown MID devices
49106ac8346SIngo Molnar
49206ac8346SIngo Molnar	  If you have one of these systems, or if you want to build a
49306ac8346SIngo Molnar	  generic distribution kernel, say Y here - otherwise say N.
4948425091fSRavikiran G Thirumalaiendif
49506ac8346SIngo Molnar
4968425091fSRavikiran G Thirumalaiif X86_64
4978425091fSRavikiran G Thirumalaiconfig X86_EXTENDED_PLATFORM
4988425091fSRavikiran G Thirumalai	bool "Support for extended (non-PC) x86 platforms"
4998425091fSRavikiran G Thirumalai	default y
5008425091fSRavikiran G Thirumalai	---help---
5018425091fSRavikiran G Thirumalai	  If you disable this option then the kernel will only support
5028425091fSRavikiran G Thirumalai	  standard PC platforms. (which covers the vast majority of
5038425091fSRavikiran G Thirumalai	  systems out there.)
5048425091fSRavikiran G Thirumalai
5058425091fSRavikiran G Thirumalai	  If you enable this option then you'll be able to select support
5068425091fSRavikiran G Thirumalai	  for the following (non-PC) 64 bit x86 platforms:
50744b111b5SSteffen Persvold		Numascale NumaChip
5088425091fSRavikiran G Thirumalai		ScaleMP vSMP
5098425091fSRavikiran G Thirumalai		SGI Ultraviolet
5108425091fSRavikiran G Thirumalai
5118425091fSRavikiran G Thirumalai	  If you have one of these systems, or if you want to build a
5128425091fSRavikiran G Thirumalai	  generic distribution kernel, say Y here - otherwise say N.
5138425091fSRavikiran G Thirumalaiendif
514c5c606d9SRavikiran G Thirumalai# This is an alphabetically sorted list of 64 bit extended platforms
515c5c606d9SRavikiran G Thirumalai# Please maintain the alphabetic order if and when there are additions
51644b111b5SSteffen Persvoldconfig X86_NUMACHIP
51744b111b5SSteffen Persvold	bool "Numascale NumaChip"
51844b111b5SSteffen Persvold	depends on X86_64
51944b111b5SSteffen Persvold	depends on X86_EXTENDED_PLATFORM
52044b111b5SSteffen Persvold	depends on NUMA
52144b111b5SSteffen Persvold	depends on SMP
52244b111b5SSteffen Persvold	depends on X86_X2APIC
523f9726bfdSDaniel J Blueman	depends on PCI_MMCONFIG
52444b111b5SSteffen Persvold	---help---
52544b111b5SSteffen Persvold	  Adds support for Numascale NumaChip large-SMP systems. Needed to
52644b111b5SSteffen Persvold	  enable more than ~168 cores.
52744b111b5SSteffen Persvold	  If you don't have one of these, you should say N here.
52803b48632SNick Piggin
5296a48565eSIngo Molnarconfig X86_VSMP
530c5c606d9SRavikiran G Thirumalai	bool "ScaleMP vSMP"
5316276a074SBorislav Petkov	select HYPERVISOR_GUEST
5326a48565eSIngo Molnar	select PARAVIRT
5336a48565eSIngo Molnar	depends on X86_64 && PCI
534c5c606d9SRavikiran G Thirumalai	depends on X86_EXTENDED_PLATFORM
535ead91d4bSShai Fultheim	depends on SMP
5368f9ca475SIngo Molnar	---help---
5376a48565eSIngo Molnar	  Support for ScaleMP vSMP systems.  Say 'Y' here if this kernel is
5386a48565eSIngo Molnar	  supposed to run on these EM64T-based machines.  Only choose this option
5396a48565eSIngo Molnar	  if you have one of these machines.
5406a48565eSIngo Molnar
541c5c606d9SRavikiran G Thirumalaiconfig X86_UV
542c5c606d9SRavikiran G Thirumalai	bool "SGI Ultraviolet"
543c5c606d9SRavikiran G Thirumalai	depends on X86_64
544c5c606d9SRavikiran G Thirumalai	depends on X86_EXTENDED_PLATFORM
54554c28d29SJack Steiner	depends on NUMA
5461ecb4ae5SAndrew Morton	depends on EFI
5479d6c26e7SSuresh Siddha	depends on X86_X2APIC
5481222e564SIngo Molnar	depends on PCI
549c5c606d9SRavikiran G Thirumalai	---help---
550c5c606d9SRavikiran G Thirumalai	  This option is needed in order to support SGI Ultraviolet systems.
551c5c606d9SRavikiran G Thirumalai	  If you don't have one of these, you should say N here.
552c5c606d9SRavikiran G Thirumalai
553c5c606d9SRavikiran G Thirumalai# Following is an alphabetically sorted list of 32 bit extended platforms
554c5c606d9SRavikiran G Thirumalai# Please maintain the alphabetic order if and when there are additions
555506f1d07SSam Ravnborg
556ddd70cf9SJun Nakajimaconfig X86_GOLDFISH
557ddd70cf9SJun Nakajima       bool "Goldfish (Virtual Platform)"
558cb7b8023SBen Hutchings       depends on X86_EXTENDED_PLATFORM
559ddd70cf9SJun Nakajima       ---help---
560ddd70cf9SJun Nakajima	 Enable support for the Goldfish virtual platform used primarily
561ddd70cf9SJun Nakajima	 for Android development. Unless you are building for the Android
562ddd70cf9SJun Nakajima	 Goldfish emulator say N here.
563ddd70cf9SJun Nakajima
564c751e17bSThomas Gleixnerconfig X86_INTEL_CE
565c751e17bSThomas Gleixner	bool "CE4100 TV platform"
566c751e17bSThomas Gleixner	depends on PCI
567c751e17bSThomas Gleixner	depends on PCI_GODIRECT
5686084a6e2SJiang Liu	depends on X86_IO_APIC
569c751e17bSThomas Gleixner	depends on X86_32
570c751e17bSThomas Gleixner	depends on X86_EXTENDED_PLATFORM
57137bc9f50SDirk Brandewie	select X86_REBOOTFIXUPS
572da6b737bSSebastian Andrzej Siewior	select OF
573da6b737bSSebastian Andrzej Siewior	select OF_EARLY_FLATTREE
574c751e17bSThomas Gleixner	---help---
575c751e17bSThomas Gleixner	  Select for the Intel CE media processor (CE4100) SOC.
576c751e17bSThomas Gleixner	  This option compiles in support for the CE4100 SOC for settop
577c751e17bSThomas Gleixner	  boxes and media devices.
578c751e17bSThomas Gleixner
5794cb9b00fSDavid Cohenconfig X86_INTEL_MID
58043605ef1SAlan Cox	bool "Intel MID platform support"
58143605ef1SAlan Cox	depends on X86_EXTENDED_PLATFORM
582edc6bc78SDavid Cohen	depends on X86_PLATFORM_DEVICES
5831ea7c673SAlan Cox	depends on PCI
5843fda5bb4SAndy Shevchenko	depends on X86_64 || (PCI_GOANY && X86_32)
5851ea7c673SAlan Cox	depends on X86_IO_APIC
5867c9c3a1eSAlan Cox	select SFI
5874cb9b00fSDavid Cohen	select I2C
5887c9c3a1eSAlan Cox	select DW_APB_TIMER
5891ea7c673SAlan Cox	select APB_TIMER
5901ea7c673SAlan Cox	select INTEL_SCU_IPC
59115a713dfSMika Westerberg	select MFD_INTEL_MSIC
5921ea7c673SAlan Cox	---help---
5934cb9b00fSDavid Cohen	  Select to build a kernel capable of supporting Intel MID (Mobile
5944cb9b00fSDavid Cohen	  Internet Device) platform systems which do not have the PCI legacy
5954cb9b00fSDavid Cohen	  interfaces. If you are building for a PC class system say N here.
5961ea7c673SAlan Cox
5974cb9b00fSDavid Cohen	  Intel MID platforms are based on an Intel processor and chipset which
5984cb9b00fSDavid Cohen	  consume less power than most of the x86 derivatives.
59943605ef1SAlan Cox
6008bbc2a13SBryan O'Donoghueconfig X86_INTEL_QUARK
6018bbc2a13SBryan O'Donoghue	bool "Intel Quark platform support"
6028bbc2a13SBryan O'Donoghue	depends on X86_32
6038bbc2a13SBryan O'Donoghue	depends on X86_EXTENDED_PLATFORM
6048bbc2a13SBryan O'Donoghue	depends on X86_PLATFORM_DEVICES
6058bbc2a13SBryan O'Donoghue	depends on X86_TSC
6068bbc2a13SBryan O'Donoghue	depends on PCI
6078bbc2a13SBryan O'Donoghue	depends on PCI_GOANY
6088bbc2a13SBryan O'Donoghue	depends on X86_IO_APIC
6098bbc2a13SBryan O'Donoghue	select IOSF_MBI
6108bbc2a13SBryan O'Donoghue	select INTEL_IMR
6119ab6eb51SAndy Shevchenko	select COMMON_CLK
6128bbc2a13SBryan O'Donoghue	---help---
6138bbc2a13SBryan O'Donoghue	  Select to include support for Quark X1000 SoC.
6148bbc2a13SBryan O'Donoghue	  Say Y here if you have a Quark based system such as the Arduino
6158bbc2a13SBryan O'Donoghue	  compatible Intel Galileo.
6168bbc2a13SBryan O'Donoghue
6173d48aab1SMika Westerbergconfig X86_INTEL_LPSS
6183d48aab1SMika Westerberg	bool "Intel Low Power Subsystem Support"
6195962dd22SSinan Kaya	depends on X86 && ACPI && PCI
6203d48aab1SMika Westerberg	select COMMON_CLK
6210f531431SMathias Nyman	select PINCTRL
622eebb3e8dSAndy Shevchenko	select IOSF_MBI
6233d48aab1SMika Westerberg	---help---
6243d48aab1SMika Westerberg	  Select to build support for Intel Low Power Subsystem such as
6253d48aab1SMika Westerberg	  found on Intel Lynxpoint PCH. Selecting this option enables
6260f531431SMathias Nyman	  things like clock tree (common clock framework) and pincontrol
6270f531431SMathias Nyman	  which are needed by the LPSS peripheral drivers.
6283d48aab1SMika Westerberg
62992082a88SKen Xueconfig X86_AMD_PLATFORM_DEVICE
63092082a88SKen Xue	bool "AMD ACPI2Platform devices support"
63192082a88SKen Xue	depends on ACPI
63292082a88SKen Xue	select COMMON_CLK
63392082a88SKen Xue	select PINCTRL
63492082a88SKen Xue	---help---
63592082a88SKen Xue	  Select to interpret AMD specific ACPI device to platform device
63692082a88SKen Xue	  such as I2C, UART, GPIO found on AMD Carrizo and later chipsets.
63792082a88SKen Xue	  I2C and UART depend on COMMON_CLK to set clock. GPIO driver is
63892082a88SKen Xue	  implemented under PINCTRL subsystem.
63992082a88SKen Xue
640ced3ce76SDavid E. Boxconfig IOSF_MBI
641ced3ce76SDavid E. Box	tristate "Intel SoC IOSF Sideband support for SoC platforms"
642ced3ce76SDavid E. Box	depends on PCI
643ced3ce76SDavid E. Box	---help---
644ced3ce76SDavid E. Box	  This option enables sideband register access support for Intel SoC
645ced3ce76SDavid E. Box	  platforms. On these platforms the IOSF sideband is used in lieu of
646ced3ce76SDavid E. Box	  MSR's for some register accesses, mostly but not limited to thermal
647ced3ce76SDavid E. Box	  and power. Drivers may query the availability of this device to
648ced3ce76SDavid E. Box	  determine if they need the sideband in order to work on these
649ced3ce76SDavid E. Box	  platforms. The sideband is available on the following SoC products.
650ced3ce76SDavid E. Box	  This list is not meant to be exclusive.
651ced3ce76SDavid E. Box	   - BayTrail
652ced3ce76SDavid E. Box	   - Braswell
653ced3ce76SDavid E. Box	   - Quark
654ced3ce76SDavid E. Box
655ced3ce76SDavid E. Box	  You should say Y if you are running a kernel on one of these SoC's.
656ced3ce76SDavid E. Box
657ed2226bdSDavid E. Boxconfig IOSF_MBI_DEBUG
658ed2226bdSDavid E. Box	bool "Enable IOSF sideband access through debugfs"
659ed2226bdSDavid E. Box	depends on IOSF_MBI && DEBUG_FS
660ed2226bdSDavid E. Box	---help---
661ed2226bdSDavid E. Box	  Select this option to expose the IOSF sideband access registers (MCR,
662ed2226bdSDavid E. Box	  MDR, MCRX) through debugfs to write and read register information from
663ed2226bdSDavid E. Box	  different units on the SoC. This is most useful for obtaining device
664ed2226bdSDavid E. Box	  state information for debug and analysis. As this is a general access
665ed2226bdSDavid E. Box	  mechanism, users of this option would have specific knowledge of the
666ed2226bdSDavid E. Box	  device they want to access.
667ed2226bdSDavid E. Box
668ed2226bdSDavid E. Box	  If you don't require the option or are in doubt, say N.
669ed2226bdSDavid E. Box
670c5c606d9SRavikiran G Thirumalaiconfig X86_RDC321X
671c5c606d9SRavikiran G Thirumalai	bool "RDC R-321x SoC"
672506f1d07SSam Ravnborg	depends on X86_32
673c5c606d9SRavikiran G Thirumalai	depends on X86_EXTENDED_PLATFORM
674c5c606d9SRavikiran G Thirumalai	select M486
675c5c606d9SRavikiran G Thirumalai	select X86_REBOOTFIXUPS
676c5c606d9SRavikiran G Thirumalai	---help---
677c5c606d9SRavikiran G Thirumalai	  This option is needed for RDC R-321x system-on-chip, also known
678c5c606d9SRavikiran G Thirumalai	  as R-8610-(G).
679c5c606d9SRavikiran G Thirumalai	  If you don't have one of these chips, you should say N here.
680c5c606d9SRavikiran G Thirumalai
681e0c7ae37SIngo Molnarconfig X86_32_NON_STANDARD
6829c398017SIngo Molnar	bool "Support non-standard 32-bit SMP architectures"
6839c398017SIngo Molnar	depends on X86_32 && SMP
684c5c606d9SRavikiran G Thirumalai	depends on X86_EXTENDED_PLATFORM
6858f9ca475SIngo Molnar	---help---
686b5660ba7SH. Peter Anvin	  This option compiles in the bigsmp and STA2X11 default
687b5660ba7SH. Peter Anvin	  subarchitectures.  It is intended for a generic binary
688b5660ba7SH. Peter Anvin	  kernel. If you select them all, kernel will probe it one by
689b5660ba7SH. Peter Anvin	  one and will fallback to default.
690d49c4288SYinghai Lu
691c5c606d9SRavikiran G Thirumalai# Alphabetically sorted list of Non standard 32 bit platforms
692d49c4288SYinghai Lu
693d949f36fSLinus Torvaldsconfig X86_SUPPORTS_MEMORY_FAILURE
6946fc108a0SJan Beulich	def_bool y
695d949f36fSLinus Torvalds	# MCE code calls memory_failure():
696d949f36fSLinus Torvalds	depends on X86_MCE
697d949f36fSLinus Torvalds	# On 32-bit this adds too big of NODES_SHIFT and we run out of page flags:
698d949f36fSLinus Torvalds	# On 32-bit SPARSEMEM adds too big of SECTIONS_WIDTH:
699d949f36fSLinus Torvalds	depends on X86_64 || !SPARSEMEM
700d949f36fSLinus Torvalds	select ARCH_SUPPORTS_MEMORY_FAILURE
701d949f36fSLinus Torvalds
70283125a3aSAlessandro Rubiniconfig STA2X11
70383125a3aSAlessandro Rubini	bool "STA2X11 Companion Chip Support"
70483125a3aSAlessandro Rubini	depends on X86_32_NON_STANDARD && PCI
705b6e05477SChristoph Hellwig	select ARCH_HAS_PHYS_TO_DMA
70683125a3aSAlessandro Rubini	select X86_DEV_DMA_OPS
70783125a3aSAlessandro Rubini	select X86_DMA_REMAP
70883125a3aSAlessandro Rubini	select SWIOTLB
70983125a3aSAlessandro Rubini	select MFD_STA2X11
7100145071bSLinus Walleij	select GPIOLIB
71183125a3aSAlessandro Rubini	---help---
71283125a3aSAlessandro Rubini	  This adds support for boards based on the STA2X11 IO-Hub,
71383125a3aSAlessandro Rubini	  a.k.a. "ConneXt". The chip is used in place of the standard
71483125a3aSAlessandro Rubini	  PC chipset, so all "standard" peripherals are missing. If this
71583125a3aSAlessandro Rubini	  option is selected the kernel will still be able to boot on
71683125a3aSAlessandro Rubini	  standard PC machines.
71783125a3aSAlessandro Rubini
71882148d1dSShérabconfig X86_32_IRIS
71982148d1dSShérab	tristate "Eurobraille/Iris poweroff module"
72082148d1dSShérab	depends on X86_32
72182148d1dSShérab	---help---
72282148d1dSShérab	  The Iris machines from EuroBraille do not have APM or ACPI support
72382148d1dSShérab	  to shut themselves down properly.  A special I/O sequence is
72482148d1dSShérab	  needed to do so, which is what this module does at
72582148d1dSShérab	  kernel shutdown.
72682148d1dSShérab
72782148d1dSShérab	  This is only for Iris machines from EuroBraille.
72882148d1dSShérab
72982148d1dSShérab	  If unused, say N.
73082148d1dSShérab
731ae1e9130SIngo Molnarconfig SCHED_OMIT_FRAME_POINTER
7323c2362e6SHarvey Harrison	def_bool y
7333c2362e6SHarvey Harrison	prompt "Single-depth WCHAN output"
734a87d0914SKen Chen	depends on X86
7358f9ca475SIngo Molnar	---help---
736506f1d07SSam Ravnborg	  Calculate simpler /proc/<PID>/wchan values. If this option
737506f1d07SSam Ravnborg	  is disabled then wchan values will recurse back to the
738506f1d07SSam Ravnborg	  caller function. This provides more accurate wchan values,
739506f1d07SSam Ravnborg	  at the expense of slightly more scheduling overhead.
740506f1d07SSam Ravnborg
741506f1d07SSam Ravnborg	  If in doubt, say "Y".
742506f1d07SSam Ravnborg
7436276a074SBorislav Petkovmenuconfig HYPERVISOR_GUEST
7446276a074SBorislav Petkov	bool "Linux guest support"
7458f9ca475SIngo Molnar	---help---
7466276a074SBorislav Petkov	  Say Y here to enable options for running Linux under various hyper-
7476276a074SBorislav Petkov	  visors. This option enables basic hypervisor detection and platform
7486276a074SBorislav Petkov	  setup.
749506f1d07SSam Ravnborg
7506276a074SBorislav Petkov	  If you say N, all options in this submenu will be skipped and
7516276a074SBorislav Petkov	  disabled, and Linux guest support won't be built in.
752506f1d07SSam Ravnborg
7536276a074SBorislav Petkovif HYPERVISOR_GUEST
754506f1d07SSam Ravnborg
755e61bd94aSEduardo Pereira Habkostconfig PARAVIRT
756e61bd94aSEduardo Pereira Habkost	bool "Enable paravirtualization code"
7578f9ca475SIngo Molnar	---help---
758e61bd94aSEduardo Pereira Habkost	  This changes the kernel so it can modify itself when it is run
759e61bd94aSEduardo Pereira Habkost	  under a hypervisor, potentially improving performance significantly
760e61bd94aSEduardo Pereira Habkost	  over full virtualization.  However, when run without a hypervisor
761e61bd94aSEduardo Pereira Habkost	  the kernel is theoretically slower and slightly larger.
762e61bd94aSEduardo Pereira Habkost
763c00a280aSJuergen Grossconfig PARAVIRT_XXL
764c00a280aSJuergen Gross	bool
765c00a280aSJuergen Gross
7666276a074SBorislav Petkovconfig PARAVIRT_DEBUG
7676276a074SBorislav Petkov	bool "paravirt-ops debugging"
7686276a074SBorislav Petkov	depends on PARAVIRT && DEBUG_KERNEL
7696276a074SBorislav Petkov	---help---
7706276a074SBorislav Petkov	  Enable to debug paravirt_ops internals.  Specifically, BUG if
7716276a074SBorislav Petkov	  a paravirt_op is missing when it is called.
7726276a074SBorislav Petkov
773b4ecc126SJeremy Fitzhardingeconfig PARAVIRT_SPINLOCKS
774b4ecc126SJeremy Fitzhardinge	bool "Paravirtualization layer for spinlocks"
7756ea30386SKees Cook	depends on PARAVIRT && SMP
776b4ecc126SJeremy Fitzhardinge	---help---
777b4ecc126SJeremy Fitzhardinge	  Paravirtualized spinlocks allow a pvops backend to replace the
778b4ecc126SJeremy Fitzhardinge	  spinlock implementation with something virtualization-friendly
779b4ecc126SJeremy Fitzhardinge	  (for example, block the virtual CPU rather than spinning).
780b4ecc126SJeremy Fitzhardinge
7814c4e4f61SRaghavendra K T	  It has a minimal impact on native kernels and gives a nice performance
7824c4e4f61SRaghavendra K T	  benefit on paravirtualized KVM / Xen kernels.
783b4ecc126SJeremy Fitzhardinge
7844c4e4f61SRaghavendra K T	  If you are unsure how to answer this question, answer Y.
785b4ecc126SJeremy Fitzhardinge
78645e898b7SWaiman Longconfig QUEUED_LOCK_STAT
78745e898b7SWaiman Long	bool "Paravirt queued spinlock statistics"
788cfd8983fSPeter Zijlstra	depends on PARAVIRT_SPINLOCKS && DEBUG_FS
78945e898b7SWaiman Long	---help---
79045e898b7SWaiman Long	  Enable the collection of statistical data on the slowpath
79145e898b7SWaiman Long	  behavior of paravirtualized queued spinlocks and report
79245e898b7SWaiman Long	  them on debugfs.
79345e898b7SWaiman Long
7946276a074SBorislav Petkovsource "arch/x86/xen/Kconfig"
7956276a074SBorislav Petkov
7966276a074SBorislav Petkovconfig KVM_GUEST
7976276a074SBorislav Petkov	bool "KVM Guest support (including kvmclock)"
7986276a074SBorislav Petkov	depends on PARAVIRT
7996276a074SBorislav Petkov	select PARAVIRT_CLOCK
8006276a074SBorislav Petkov	default y
8016276a074SBorislav Petkov	---help---
8026276a074SBorislav Petkov	  This option enables various optimizations for running under the KVM
8036276a074SBorislav Petkov	  hypervisor. It includes a paravirtualized clock, so that instead
8046276a074SBorislav Petkov	  of relying on a PIT (or probably other) emulation by the
8056276a074SBorislav Petkov	  underlying device model, the host provides the guest with
8066276a074SBorislav Petkov	  timing infrastructure such as time of day, and system time
8076276a074SBorislav Petkov
8087733607fSMaran Wilsonconfig PVH
8097733607fSMaran Wilson	bool "Support for running PVH guests"
8107733607fSMaran Wilson	---help---
8117733607fSMaran Wilson	  This option enables the PVH entry point for guest virtual machines
8127733607fSMaran Wilson	  as specified in the x86/HVM direct boot ABI.
8137733607fSMaran Wilson
8141e20eb85SSrivatsa Vaddagiriconfig KVM_DEBUG_FS
8151e20eb85SSrivatsa Vaddagiri	bool "Enable debug information for KVM Guests in debugfs"
8161e20eb85SSrivatsa Vaddagiri	depends on KVM_GUEST && DEBUG_FS
8171e20eb85SSrivatsa Vaddagiri	---help---
8181e20eb85SSrivatsa Vaddagiri	  This option enables collection of various statistics for KVM guest.
8191e20eb85SSrivatsa Vaddagiri	  Statistics are displayed in debugfs filesystem. Enabling this option
8201e20eb85SSrivatsa Vaddagiri	  may incur significant overhead.
8211e20eb85SSrivatsa Vaddagiri
8226276a074SBorislav Petkovconfig PARAVIRT_TIME_ACCOUNTING
8236276a074SBorislav Petkov	bool "Paravirtual steal time accounting"
8246276a074SBorislav Petkov	depends on PARAVIRT
8256276a074SBorislav Petkov	---help---
8266276a074SBorislav Petkov	  Select this option to enable fine granularity task steal time
8276276a074SBorislav Petkov	  accounting. Time spent executing other tasks in parallel with
8286276a074SBorislav Petkov	  the current vCPU is discounted from the vCPU power. To account for
8296276a074SBorislav Petkov	  that, there can be a small performance impact.
8306276a074SBorislav Petkov
8316276a074SBorislav Petkov	  If in doubt, say N here.
8326276a074SBorislav Petkov
8337af192c9SGerd Hoffmannconfig PARAVIRT_CLOCK
8347af192c9SGerd Hoffmann	bool
8357af192c9SGerd Hoffmann
8364a362601SJan Kiszkaconfig JAILHOUSE_GUEST
8374a362601SJan Kiszka	bool "Jailhouse non-root cell support"
838abde587bSArnd Bergmann	depends on X86_64 && PCI
83987e65d05SJan Kiszka	select X86_PM_TIMER
8404a362601SJan Kiszka	---help---
8414a362601SJan Kiszka	  This option allows to run Linux as guest in a Jailhouse non-root
8424a362601SJan Kiszka	  cell. You can leave this option disabled if you only want to start
8434a362601SJan Kiszka	  Jailhouse and run Linux afterwards in the root cell.
8444a362601SJan Kiszka
8456276a074SBorislav Petkovendif #HYPERVISOR_GUEST
84697349135SJeremy Fitzhardinge
847506f1d07SSam Ravnborgsource "arch/x86/Kconfig.cpu"
848506f1d07SSam Ravnborg
849506f1d07SSam Ravnborgconfig HPET_TIMER
8503c2362e6SHarvey Harrison	def_bool X86_64
851506f1d07SSam Ravnborg	prompt "HPET Timer Support" if X86_32
8528f9ca475SIngo Molnar	---help---
853506f1d07SSam Ravnborg	  Use the IA-PC HPET (High Precision Event Timer) to manage
854506f1d07SSam Ravnborg	  time in preference to the PIT and RTC, if a HPET is
855506f1d07SSam Ravnborg	  present.
856506f1d07SSam Ravnborg	  HPET is the next generation timer replacing legacy 8254s.
857506f1d07SSam Ravnborg	  The HPET provides a stable time base on SMP
858506f1d07SSam Ravnborg	  systems, unlike the TSC, but it is more expensive to access,
8594e7f9df2SMichael S. Tsirkin	  as it is off-chip.  The interface used is documented
8604e7f9df2SMichael S. Tsirkin	  in the HPET spec, revision 1.
861506f1d07SSam Ravnborg
862506f1d07SSam Ravnborg	  You can safely choose Y here.  However, HPET will only be
863506f1d07SSam Ravnborg	  activated if the platform and the BIOS support this feature.
864506f1d07SSam Ravnborg	  Otherwise the 8254 will be used for timing services.
865506f1d07SSam Ravnborg
866506f1d07SSam Ravnborg	  Choose N to continue using the legacy 8254 timer.
867506f1d07SSam Ravnborg
868506f1d07SSam Ravnborgconfig HPET_EMULATE_RTC
8693c2362e6SHarvey Harrison	def_bool y
8709d8af78bSBernhard Walle	depends on HPET_TIMER && (RTC=y || RTC=m || RTC_DRV_CMOS=m || RTC_DRV_CMOS=y)
871506f1d07SSam Ravnborg
872bb24c471SJacob Panconfig APB_TIMER
873933b9463SAlan Cox       def_bool y if X86_INTEL_MID
874933b9463SAlan Cox       prompt "Intel MID APB Timer Support" if X86_INTEL_MID
87506c3df49SJamie Iles       select DW_APB_TIMER
876a0c3832aSAlan Cox       depends on X86_INTEL_MID && SFI
877bb24c471SJacob Pan       help
878bb24c471SJacob Pan         APB timer is the replacement for 8254, HPET on X86 MID platforms.
879bb24c471SJacob Pan         The APBT provides a stable time base on SMP
880bb24c471SJacob Pan         systems, unlike the TSC, but it is more expensive to access,
881bb24c471SJacob Pan         as it is off-chip. APB timers are always running regardless of CPU
882bb24c471SJacob Pan         C states, they are used as per CPU clockevent device when possible.
883bb24c471SJacob Pan
8846a108a14SDavid Rientjes# Mark as expert because too many people got it wrong.
885506f1d07SSam Ravnborg# The code disables itself when not needed.
8867ae9392cSThomas Petazzoniconfig DMI
8877ae9392cSThomas Petazzoni	default y
888cf074402SArd Biesheuvel	select DMI_SCAN_MACHINE_NON_EFI_FALLBACK
8896a108a14SDavid Rientjes	bool "Enable DMI scanning" if EXPERT
8908f9ca475SIngo Molnar	---help---
8917ae9392cSThomas Petazzoni	  Enabled scanning of DMI to identify machine quirks. Say Y
8927ae9392cSThomas Petazzoni	  here unless you have verified that your setup is not
8937ae9392cSThomas Petazzoni	  affected by entries in the DMI blacklist. Required by PNP
8947ae9392cSThomas Petazzoni	  BIOS code.
8957ae9392cSThomas Petazzoni
896506f1d07SSam Ravnborgconfig GART_IOMMU
89738901f1cSAndi Kleen	bool "Old AMD GART IOMMU support"
898a4ce5a48SChristoph Hellwig	select IOMMU_HELPER
899506f1d07SSam Ravnborg	select SWIOTLB
90023ac4ae8SAndreas Herrmann	depends on X86_64 && PCI && AMD_NB
9018f9ca475SIngo Molnar	---help---
902ced3c42cSIngo Molnar	  Provides a driver for older AMD Athlon64/Opteron/Turion/Sempron
903ced3c42cSIngo Molnar	  GART based hardware IOMMUs.
904ced3c42cSIngo Molnar
905ced3c42cSIngo Molnar	  The GART supports full DMA access for devices with 32-bit access
906ced3c42cSIngo Molnar	  limitations, on systems with more than 3 GB. This is usually needed
907ced3c42cSIngo Molnar	  for USB, sound, many IDE/SATA chipsets and some other devices.
908ced3c42cSIngo Molnar
909ced3c42cSIngo Molnar	  Newer systems typically have a modern AMD IOMMU, supported via
910ced3c42cSIngo Molnar	  the CONFIG_AMD_IOMMU=y config option.
911ced3c42cSIngo Molnar
912ced3c42cSIngo Molnar	  In normal configurations this driver is only active when needed:
913ced3c42cSIngo Molnar	  there's more than 3 GB of memory and the system contains a
914ced3c42cSIngo Molnar	  32-bit limited device.
915ced3c42cSIngo Molnar
916ced3c42cSIngo Molnar	  If unsure, say Y.
917506f1d07SSam Ravnborg
918506f1d07SSam Ravnborgconfig CALGARY_IOMMU
919506f1d07SSam Ravnborg	bool "IBM Calgary IOMMU support"
920a4ce5a48SChristoph Hellwig	select IOMMU_HELPER
921506f1d07SSam Ravnborg	select SWIOTLB
9226ea30386SKees Cook	depends on X86_64 && PCI
9238f9ca475SIngo Molnar	---help---
924506f1d07SSam Ravnborg	  Support for hardware IOMMUs in IBM's xSeries x366 and x460
925506f1d07SSam Ravnborg	  systems. Needed to run systems with more than 3GB of memory
926506f1d07SSam Ravnborg	  properly with 32-bit PCI devices that do not support DAC
927506f1d07SSam Ravnborg	  (Double Address Cycle). Calgary also supports bus level
928506f1d07SSam Ravnborg	  isolation, where all DMAs pass through the IOMMU.  This
929506f1d07SSam Ravnborg	  prevents them from going anywhere except their intended
930506f1d07SSam Ravnborg	  destination. This catches hard-to-find kernel bugs and
931506f1d07SSam Ravnborg	  mis-behaving drivers and devices that do not use the DMA-API
932506f1d07SSam Ravnborg	  properly to set up their DMA buffers.  The IOMMU can be
933506f1d07SSam Ravnborg	  turned off at boot time with the iommu=off parameter.
934506f1d07SSam Ravnborg	  Normally the kernel will make the right choice by itself.
935506f1d07SSam Ravnborg	  If unsure, say Y.
936506f1d07SSam Ravnborg
937506f1d07SSam Ravnborgconfig CALGARY_IOMMU_ENABLED_BY_DEFAULT
9383c2362e6SHarvey Harrison	def_bool y
9393c2362e6SHarvey Harrison	prompt "Should Calgary be enabled by default?"
940506f1d07SSam Ravnborg	depends on CALGARY_IOMMU
9418f9ca475SIngo Molnar	---help---
942506f1d07SSam Ravnborg	  Should Calgary be enabled by default? if you choose 'y', Calgary
943506f1d07SSam Ravnborg	  will be used (if it exists). If you choose 'n', Calgary will not be
944506f1d07SSam Ravnborg	  used even if it exists. If you choose 'n' and would like to use
945506f1d07SSam Ravnborg	  Calgary anyway, pass 'iommu=calgary' on the kernel command line.
946506f1d07SSam Ravnborg	  If unsure, say Y.
947506f1d07SSam Ravnborg
9481184dc2fSMike Travisconfig MAXSMP
949ddb0c5a6SSamuel Thibault	bool "Enable Maximum number of SMP Processors and NUMA Nodes"
9506ea30386SKees Cook	depends on X86_64 && SMP && DEBUG_KERNEL
95136f5101aSMike Travis	select CPUMASK_OFFSTACK
9528f9ca475SIngo Molnar	---help---
953ddb0c5a6SSamuel Thibault	  Enable maximum number of CPUS and NUMA Nodes for this architecture.
9541184dc2fSMike Travis	  If unsure, say N.
955506f1d07SSam Ravnborg
956aec6487eSIngo Molnar#
957aec6487eSIngo Molnar# The maximum number of CPUs supported:
958aec6487eSIngo Molnar#
959aec6487eSIngo Molnar# The main config value is NR_CPUS, which defaults to NR_CPUS_DEFAULT,
960aec6487eSIngo Molnar# and which can be configured interactively in the
961aec6487eSIngo Molnar# [NR_CPUS_RANGE_BEGIN ... NR_CPUS_RANGE_END] range.
962aec6487eSIngo Molnar#
963aec6487eSIngo Molnar# The ranges are different on 32-bit and 64-bit kernels, depending on
964aec6487eSIngo Molnar# hardware capabilities and scalability features of the kernel.
965aec6487eSIngo Molnar#
966aec6487eSIngo Molnar# ( If MAXSMP is enabled we just use the highest possible value and disable
967aec6487eSIngo Molnar#   interactive configuration. )
968aec6487eSIngo Molnar#
969a0d0bb4dSRandy Dunlap
970aec6487eSIngo Molnarconfig NR_CPUS_RANGE_BEGIN
971a0d0bb4dSRandy Dunlap	int
972aec6487eSIngo Molnar	default NR_CPUS_RANGE_END if MAXSMP
973a0d0bb4dSRandy Dunlap	default    1 if !SMP
974a0d0bb4dSRandy Dunlap	default    2
975a0d0bb4dSRandy Dunlap
976aec6487eSIngo Molnarconfig NR_CPUS_RANGE_END
977a0d0bb4dSRandy Dunlap	int
978a0d0bb4dSRandy Dunlap	depends on X86_32
979aec6487eSIngo Molnar	default   64 if  SMP &&  X86_BIGSMP
980aec6487eSIngo Molnar	default    8 if  SMP && !X86_BIGSMP
981a0d0bb4dSRandy Dunlap	default    1 if !SMP
982a0d0bb4dSRandy Dunlap
983aec6487eSIngo Molnarconfig NR_CPUS_RANGE_END
984a0d0bb4dSRandy Dunlap	int
985a0d0bb4dSRandy Dunlap	depends on X86_64
986aec6487eSIngo Molnar	default 8192 if  SMP && ( MAXSMP ||  CPUMASK_OFFSTACK)
987aec6487eSIngo Molnar	default  512 if  SMP && (!MAXSMP && !CPUMASK_OFFSTACK)
988a0d0bb4dSRandy Dunlap	default    1 if !SMP
989aec6487eSIngo Molnar
990aec6487eSIngo Molnarconfig NR_CPUS_DEFAULT
991aec6487eSIngo Molnar	int
992aec6487eSIngo Molnar	depends on X86_32
993aec6487eSIngo Molnar	default   32 if  X86_BIGSMP
994aec6487eSIngo Molnar	default    8 if  SMP
995aec6487eSIngo Molnar	default    1 if !SMP
996aec6487eSIngo Molnar
997aec6487eSIngo Molnarconfig NR_CPUS_DEFAULT
998aec6487eSIngo Molnar	int
999aec6487eSIngo Molnar	depends on X86_64
1000a0d0bb4dSRandy Dunlap	default 8192 if  MAXSMP
1001a0d0bb4dSRandy Dunlap	default   64 if  SMP
1002aec6487eSIngo Molnar	default    1 if !SMP
1003a0d0bb4dSRandy Dunlap
1004506f1d07SSam Ravnborgconfig NR_CPUS
100536f5101aSMike Travis	int "Maximum number of CPUs" if SMP && !MAXSMP
1006aec6487eSIngo Molnar	range NR_CPUS_RANGE_BEGIN NR_CPUS_RANGE_END
1007aec6487eSIngo Molnar	default NR_CPUS_DEFAULT
10088f9ca475SIngo Molnar	---help---
1009506f1d07SSam Ravnborg	  This allows you to specify the maximum number of CPUs which this
1010bb61ccc7SJosh Boyer	  kernel will support.  If CPUMASK_OFFSTACK is enabled, the maximum
1011cad14bb9SKirill A. Shutemov	  supported value is 8192, otherwise the maximum value is 512.  The
1012506f1d07SSam Ravnborg	  minimum value which makes sense is 2.
1013506f1d07SSam Ravnborg
1014aec6487eSIngo Molnar	  This is purely to save memory: each supported CPU adds about 8KB
1015aec6487eSIngo Molnar	  to the kernel image.
1016506f1d07SSam Ravnborg
1017506f1d07SSam Ravnborgconfig SCHED_SMT
1018dbe73364SThomas Gleixner	def_bool y if SMP
1019506f1d07SSam Ravnborg
1020506f1d07SSam Ravnborgconfig SCHED_MC
10213c2362e6SHarvey Harrison	def_bool y
10223c2362e6SHarvey Harrison	prompt "Multi-core scheduler support"
1023c8e56d20SBorislav Petkov	depends on SMP
10248f9ca475SIngo Molnar	---help---
1025506f1d07SSam Ravnborg	  Multi-core scheduler support improves the CPU scheduler's decision
1026506f1d07SSam Ravnborg	  making when dealing with multi-core CPU chips at a cost of slightly
1027506f1d07SSam Ravnborg	  increased overhead in some places. If unsure say N here.
1028506f1d07SSam Ravnborg
1029de966cf4STim Chenconfig SCHED_MC_PRIO
1030de966cf4STim Chen	bool "CPU core priorities scheduler support"
10310a21fc12SIngo Molnar	depends on SCHED_MC && CPU_SUP_INTEL
10320a21fc12SIngo Molnar	select X86_INTEL_PSTATE
10330a21fc12SIngo Molnar	select CPU_FREQ
1034de966cf4STim Chen	default y
10355e76b2abSTim Chen	---help---
1036de966cf4STim Chen	  Intel Turbo Boost Max Technology 3.0 enabled CPUs have a
1037de966cf4STim Chen	  core ordering determined at manufacturing time, which allows
1038de966cf4STim Chen	  certain cores to reach higher turbo frequencies (when running
1039de966cf4STim Chen	  single threaded workloads) than others.
1040de966cf4STim Chen
1041de966cf4STim Chen	  Enabling this kernel feature teaches the scheduler about
1042de966cf4STim Chen	  the TBM3 (aka ITMT) priority order of the CPU cores and adjusts the
1043de966cf4STim Chen	  scheduler's CPU selection logic accordingly, so that higher
1044de966cf4STim Chen	  overall system performance can be achieved.
1045de966cf4STim Chen
1046de966cf4STim Chen	  This feature will have no effect on CPUs without this feature.
1047de966cf4STim Chen
1048de966cf4STim Chen	  If unsure say Y here.
10495e76b2abSTim Chen
105030b8b006SThomas Gleixnerconfig UP_LATE_INIT
105130b8b006SThomas Gleixner       def_bool y
1052ba360f88SThomas Gleixner       depends on !SMP && X86_LOCAL_APIC
105330b8b006SThomas Gleixner
1054506f1d07SSam Ravnborgconfig X86_UP_APIC
105550849eefSJan Beulich	bool "Local APIC support on uniprocessors" if !PCI_MSI
105650849eefSJan Beulich	default PCI_MSI
105738a1dfdaSBryan O'Donoghue	depends on X86_32 && !SMP && !X86_32_NON_STANDARD
10588f9ca475SIngo Molnar	---help---
1059506f1d07SSam Ravnborg	  A local APIC (Advanced Programmable Interrupt Controller) is an
1060506f1d07SSam Ravnborg	  integrated interrupt controller in the CPU. If you have a single-CPU
1061506f1d07SSam Ravnborg	  system which has a processor with a local APIC, you can say Y here to
1062506f1d07SSam Ravnborg	  enable and use it. If you say Y here even though your machine doesn't
1063506f1d07SSam Ravnborg	  have a local APIC, then the kernel will still run with no slowdown at
1064506f1d07SSam Ravnborg	  all. The local APIC supports CPU-generated self-interrupts (timer,
1065506f1d07SSam Ravnborg	  performance counters), and the NMI watchdog which detects hard
1066506f1d07SSam Ravnborg	  lockups.
1067506f1d07SSam Ravnborg
1068506f1d07SSam Ravnborgconfig X86_UP_IOAPIC
1069506f1d07SSam Ravnborg	bool "IO-APIC support on uniprocessors"
1070506f1d07SSam Ravnborg	depends on X86_UP_APIC
10718f9ca475SIngo Molnar	---help---
1072506f1d07SSam Ravnborg	  An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an
1073506f1d07SSam Ravnborg	  SMP-capable replacement for PC-style interrupt controllers. Most
1074506f1d07SSam Ravnborg	  SMP systems and many recent uniprocessor systems have one.
1075506f1d07SSam Ravnborg
1076506f1d07SSam Ravnborg	  If you have a single-CPU system with an IO-APIC, you can say Y here
1077506f1d07SSam Ravnborg	  to use it. If you say Y here even though your machine doesn't have
1078506f1d07SSam Ravnborg	  an IO-APIC, then the kernel will still run with no slowdown at all.
1079506f1d07SSam Ravnborg
1080506f1d07SSam Ravnborgconfig X86_LOCAL_APIC
10813c2362e6SHarvey Harrison	def_bool y
10820dbc6078SThomas Petazzoni	depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC || PCI_MSI
1083b5dc8e6cSJiang Liu	select IRQ_DOMAIN_HIERARCHY
108452f518a3SJiang Liu	select PCI_MSI_IRQ_DOMAIN if PCI_MSI
1085506f1d07SSam Ravnborg
1086506f1d07SSam Ravnborgconfig X86_IO_APIC
1087b1da1e71SJan Beulich	def_bool y
1088b1da1e71SJan Beulich	depends on X86_LOCAL_APIC || X86_UP_IOAPIC
1089506f1d07SSam Ravnborg
109041b9eb26SStefan Assmannconfig X86_REROUTE_FOR_BROKEN_BOOT_IRQS
109141b9eb26SStefan Assmann	bool "Reroute for broken boot IRQs"
109241b9eb26SStefan Assmann	depends on X86_IO_APIC
10938f9ca475SIngo Molnar	---help---
109441b9eb26SStefan Assmann	  This option enables a workaround that fixes a source of
109541b9eb26SStefan Assmann	  spurious interrupts. This is recommended when threaded
109641b9eb26SStefan Assmann	  interrupt handling is used on systems where the generation of
109741b9eb26SStefan Assmann	  superfluous "boot interrupts" cannot be disabled.
109841b9eb26SStefan Assmann
109941b9eb26SStefan Assmann	  Some chipsets generate a legacy INTx "boot IRQ" when the IRQ
110041b9eb26SStefan Assmann	  entry in the chipset's IO-APIC is masked (as, e.g. the RT
110141b9eb26SStefan Assmann	  kernel does during interrupt handling). On chipsets where this
110241b9eb26SStefan Assmann	  boot IRQ generation cannot be disabled, this workaround keeps
110341b9eb26SStefan Assmann	  the original IRQ line masked so that only the equivalent "boot
110441b9eb26SStefan Assmann	  IRQ" is delivered to the CPUs. The workaround also tells the
110541b9eb26SStefan Assmann	  kernel to set up the IRQ handler on the boot IRQ line. In this
110641b9eb26SStefan Assmann	  way only one interrupt is delivered to the kernel. Otherwise
110741b9eb26SStefan Assmann	  the spurious second interrupt may cause the kernel to bring
110841b9eb26SStefan Assmann	  down (vital) interrupt lines.
110941b9eb26SStefan Assmann
111041b9eb26SStefan Assmann	  Only affects "broken" chipsets. Interrupt sharing may be
111141b9eb26SStefan Assmann	  increased on these systems.
111241b9eb26SStefan Assmann
1113506f1d07SSam Ravnborgconfig X86_MCE
1114bab9bc65SAndi Kleen	bool "Machine Check / overheating reporting"
1115648ed940SChen, Gong	select GENERIC_ALLOCATOR
1116e57dbaf7SBorislav Petkov	default y
1117506f1d07SSam Ravnborg	---help---
1118bab9bc65SAndi Kleen	  Machine Check support allows the processor to notify the
1119bab9bc65SAndi Kleen	  kernel if it detects a problem (e.g. overheating, data corruption).
1120506f1d07SSam Ravnborg	  The action the kernel takes depends on the severity of the problem,
1121bab9bc65SAndi Kleen	  ranging from warning messages to halting the machine.
11224efc0670SAndi Kleen
11235de97c9fSTony Luckconfig X86_MCELOG_LEGACY
11245de97c9fSTony Luck	bool "Support for deprecated /dev/mcelog character device"
11255de97c9fSTony Luck	depends on X86_MCE
11265de97c9fSTony Luck	---help---
11275de97c9fSTony Luck	  Enable support for /dev/mcelog which is needed by the old mcelog
11285de97c9fSTony Luck	  userspace logging daemon. Consider switching to the new generation
11295de97c9fSTony Luck	  rasdaemon solution.
11305de97c9fSTony Luck
1131506f1d07SSam Ravnborgconfig X86_MCE_INTEL
11323c2362e6SHarvey Harrison	def_bool y
11333c2362e6SHarvey Harrison	prompt "Intel MCE features"
1134c1ebf835SAndi Kleen	depends on X86_MCE && X86_LOCAL_APIC
11358f9ca475SIngo Molnar	---help---
1136506f1d07SSam Ravnborg	   Additional support for intel specific MCE features such as
1137506f1d07SSam Ravnborg	   the thermal monitor.
1138506f1d07SSam Ravnborg
1139506f1d07SSam Ravnborgconfig X86_MCE_AMD
11403c2362e6SHarvey Harrison	def_bool y
11413c2362e6SHarvey Harrison	prompt "AMD MCE features"
1142f5382de9SYazen Ghannam	depends on X86_MCE && X86_LOCAL_APIC && AMD_NB
11438f9ca475SIngo Molnar	---help---
1144506f1d07SSam Ravnborg	   Additional support for AMD specific MCE features such as
1145506f1d07SSam Ravnborg	   the DRAM Error Threshold.
1146506f1d07SSam Ravnborg
11474efc0670SAndi Kleenconfig X86_ANCIENT_MCE
11486fc108a0SJan Beulich	bool "Support for old Pentium 5 / WinChip machine checks"
1149c31d9633SAndi Kleen	depends on X86_32 && X86_MCE
11504efc0670SAndi Kleen	---help---
11514efc0670SAndi Kleen	  Include support for machine check handling on old Pentium 5 or WinChip
11525065a706SMasanari Iida	  systems. These typically need to be enabled explicitly on the command
11534efc0670SAndi Kleen	  line.
11544efc0670SAndi Kleen
1155b2762686SAndi Kleenconfig X86_MCE_THRESHOLD
1156b2762686SAndi Kleen	depends on X86_MCE_AMD || X86_MCE_INTEL
11576fc108a0SJan Beulich	def_bool y
1158b2762686SAndi Kleen
1159ea149b36SAndi Kleenconfig X86_MCE_INJECT
1160bc8e80d5SBorislav Petkov	depends on X86_MCE && X86_LOCAL_APIC && DEBUG_FS
1161ea149b36SAndi Kleen	tristate "Machine check injector support"
1162ea149b36SAndi Kleen	---help---
1163ea149b36SAndi Kleen	  Provide support for injecting machine checks for testing purposes.
1164ea149b36SAndi Kleen	  If you don't know what a machine check is and you don't do kernel
1165ea149b36SAndi Kleen	  QA it is safe to say n.
1166ea149b36SAndi Kleen
11674efc0670SAndi Kleenconfig X86_THERMAL_VECTOR
11684efc0670SAndi Kleen	def_bool y
11695bb38adcSAndi Kleen	depends on X86_MCE_INTEL
11704efc0670SAndi Kleen
117107dc900eSPeter Zijlstrasource "arch/x86/events/Kconfig"
1172e633c65aSKan Liang
11735aef51c3SAndy Lutomirskiconfig X86_LEGACY_VM86
11741e642812SIngo Molnar	bool "Legacy VM86 support"
1175506f1d07SSam Ravnborg	depends on X86_32
11768f9ca475SIngo Molnar	---help---
11775aef51c3SAndy Lutomirski	  This option allows user programs to put the CPU into V8086
11785aef51c3SAndy Lutomirski	  mode, which is an 80286-era approximation of 16-bit real mode.
11795aef51c3SAndy Lutomirski
11805aef51c3SAndy Lutomirski	  Some very old versions of X and/or vbetool require this option
11815aef51c3SAndy Lutomirski	  for user mode setting.  Similarly, DOSEMU will use it if
11825aef51c3SAndy Lutomirski	  available to accelerate real mode DOS programs.  However, any
11835aef51c3SAndy Lutomirski	  recent version of DOSEMU, X, or vbetool should be fully
11845aef51c3SAndy Lutomirski	  functional even without kernel VM86 support, as they will all
11851e642812SIngo Molnar	  fall back to software emulation. Nevertheless, if you are using
11861e642812SIngo Molnar	  a 16-bit DOS program where 16-bit performance matters, vm86
11871e642812SIngo Molnar	  mode might be faster than emulation and you might want to
11881e642812SIngo Molnar	  enable this option.
11895aef51c3SAndy Lutomirski
11901e642812SIngo Molnar	  Note that any app that works on a 64-bit kernel is unlikely to
11911e642812SIngo Molnar	  need this option, as 64-bit kernels don't, and can't, support
11921e642812SIngo Molnar	  V8086 mode. This option is also unrelated to 16-bit protected
11931e642812SIngo Molnar	  mode and is not needed to run most 16-bit programs under Wine.
11945aef51c3SAndy Lutomirski
11951e642812SIngo Molnar	  Enabling this option increases the complexity of the kernel
11961e642812SIngo Molnar	  and slows down exception handling a tiny bit.
11975aef51c3SAndy Lutomirski
11981e642812SIngo Molnar	  If unsure, say N here.
11995aef51c3SAndy Lutomirski
12005aef51c3SAndy Lutomirskiconfig VM86
12015aef51c3SAndy Lutomirski       bool
12025aef51c3SAndy Lutomirski       default X86_LEGACY_VM86
120334273f41SH. Peter Anvin
120434273f41SH. Peter Anvinconfig X86_16BIT
120534273f41SH. Peter Anvin	bool "Enable support for 16-bit segments" if EXPERT
120634273f41SH. Peter Anvin	default y
1207a5b9e5a2SAndy Lutomirski	depends on MODIFY_LDT_SYSCALL
120834273f41SH. Peter Anvin	---help---
120934273f41SH. Peter Anvin	  This option is required by programs like Wine to run 16-bit
121034273f41SH. Peter Anvin	  protected mode legacy code on x86 processors.  Disabling
121134273f41SH. Peter Anvin	  this option saves about 300 bytes on i386, or around 6K text
121234273f41SH. Peter Anvin	  plus 16K runtime memory on x86-64,
121334273f41SH. Peter Anvin
121434273f41SH. Peter Anvinconfig X86_ESPFIX32
121534273f41SH. Peter Anvin	def_bool y
121634273f41SH. Peter Anvin	depends on X86_16BIT && X86_32
1217506f1d07SSam Ravnborg
1218197725deSH. Peter Anvinconfig X86_ESPFIX64
1219197725deSH. Peter Anvin	def_bool y
122034273f41SH. Peter Anvin	depends on X86_16BIT && X86_64
1221506f1d07SSam Ravnborg
12221ad83c85SAndy Lutomirskiconfig X86_VSYSCALL_EMULATION
12231ad83c85SAndy Lutomirski       bool "Enable vsyscall emulation" if EXPERT
12241ad83c85SAndy Lutomirski       default y
12251ad83c85SAndy Lutomirski       depends on X86_64
12261ad83c85SAndy Lutomirski       ---help---
12271ad83c85SAndy Lutomirski	 This enables emulation of the legacy vsyscall page.  Disabling
12281ad83c85SAndy Lutomirski	 it is roughly equivalent to booting with vsyscall=none, except
12291ad83c85SAndy Lutomirski	 that it will also disable the helpful warning if a program
12301ad83c85SAndy Lutomirski	 tries to use a vsyscall.  With this option set to N, offending
12311ad83c85SAndy Lutomirski	 programs will just segfault, citing addresses of the form
12321ad83c85SAndy Lutomirski	 0xffffffffff600?00.
12331ad83c85SAndy Lutomirski
12341ad83c85SAndy Lutomirski	 This option is required by many programs built before 2013, and
12351ad83c85SAndy Lutomirski	 care should be used even with newer programs if set to N.
12361ad83c85SAndy Lutomirski
12371ad83c85SAndy Lutomirski	 Disabling this option saves about 7K of kernel size and
12381ad83c85SAndy Lutomirski	 possibly 4K of additional runtime pagetable memory.
12391ad83c85SAndy Lutomirski
1240506f1d07SSam Ravnborgconfig TOSHIBA
1241506f1d07SSam Ravnborg	tristate "Toshiba Laptop support"
1242506f1d07SSam Ravnborg	depends on X86_32
1243506f1d07SSam Ravnborg	---help---
1244506f1d07SSam Ravnborg	  This adds a driver to safely access the System Management Mode of
1245506f1d07SSam Ravnborg	  the CPU on Toshiba portables with a genuine Toshiba BIOS. It does
1246506f1d07SSam Ravnborg	  not work on models with a Phoenix BIOS. The System Management Mode
1247506f1d07SSam Ravnborg	  is used to set the BIOS and power saving options on Toshiba portables.
1248506f1d07SSam Ravnborg
1249506f1d07SSam Ravnborg	  For information on utilities to make use of this driver see the
1250506f1d07SSam Ravnborg	  Toshiba Linux utilities web site at:
1251506f1d07SSam Ravnborg	  <http://www.buzzard.org.uk/toshiba/>.
1252506f1d07SSam Ravnborg
1253506f1d07SSam Ravnborg	  Say Y if you intend to run this kernel on a Toshiba portable.
1254506f1d07SSam Ravnborg	  Say N otherwise.
1255506f1d07SSam Ravnborg
1256506f1d07SSam Ravnborgconfig I8K
1257039ae585SPali Rohár	tristate "Dell i8k legacy laptop support"
1258949a9d70SJean Delvare	select HWMON
1259039ae585SPali Rohár	select SENSORS_DELL_SMM
1260506f1d07SSam Ravnborg	---help---
1261039ae585SPali Rohár	  This option enables legacy /proc/i8k userspace interface in hwmon
1262039ae585SPali Rohár	  dell-smm-hwmon driver. Character file /proc/i8k reports bios version,
1263039ae585SPali Rohár	  temperature and allows controlling fan speeds of Dell laptops via
1264039ae585SPali Rohár	  System Management Mode. For old Dell laptops (like Dell Inspiron 8000)
1265039ae585SPali Rohár	  it reports also power and hotkey status. For fan speed control is
1266039ae585SPali Rohár	  needed userspace package i8kutils.
1267506f1d07SSam Ravnborg
1268039ae585SPali Rohár	  Say Y if you intend to run this kernel on old Dell laptops or want to
1269039ae585SPali Rohár	  use userspace package i8kutils.
1270506f1d07SSam Ravnborg	  Say N otherwise.
1271506f1d07SSam Ravnborg
1272506f1d07SSam Ravnborgconfig X86_REBOOTFIXUPS
12739ba16087SJan Beulich	bool "Enable X86 board specific fixups for reboot"
12749ba16087SJan Beulich	depends on X86_32
1275506f1d07SSam Ravnborg	---help---
1276506f1d07SSam Ravnborg	  This enables chipset and/or board specific fixups to be done
1277506f1d07SSam Ravnborg	  in order to get reboot to work correctly. This is only needed on
1278506f1d07SSam Ravnborg	  some combinations of hardware and BIOS. The symptom, for which
1279506f1d07SSam Ravnborg	  this config is intended, is when reboot ends with a stalled/hung
1280506f1d07SSam Ravnborg	  system.
1281506f1d07SSam Ravnborg
1282506f1d07SSam Ravnborg	  Currently, the only fixup is for the Geode machines using
12835e3a77e9SFlorian Fainelli	  CS5530A and CS5536 chipsets and the RDC R-321x SoC.
1284506f1d07SSam Ravnborg
1285506f1d07SSam Ravnborg	  Say Y if you want to enable the fixup. Currently, it's safe to
1286506f1d07SSam Ravnborg	  enable this option even if you don't need it.
1287506f1d07SSam Ravnborg	  Say N otherwise.
1288506f1d07SSam Ravnborg
1289506f1d07SSam Ravnborgconfig MICROCODE
12909a2bc335SBorislav Petkov	bool "CPU microcode loading support"
12919a2bc335SBorislav Petkov	default y
129280030e3dSBorislav Petkov	depends on CPU_SUP_AMD || CPU_SUP_INTEL
1293506f1d07SSam Ravnborg	select FW_LOADER
1294506f1d07SSam Ravnborg	---help---
1295506f1d07SSam Ravnborg	  If you say Y here, you will be able to update the microcode on
12965f9c01aaSBorislav Petkov	  Intel and AMD processors. The Intel support is for the IA32 family,
12975f9c01aaSBorislav Petkov	  e.g. Pentium Pro, Pentium II, Pentium III, Pentium 4, Xeon etc. The
12985f9c01aaSBorislav Petkov	  AMD support is for families 0x10 and later. You will obviously need
12995f9c01aaSBorislav Petkov	  the actual microcode binary data itself which is not shipped with
13005f9c01aaSBorislav Petkov	  the Linux kernel.
1301506f1d07SSam Ravnborg
13025f9c01aaSBorislav Petkov	  The preferred method to load microcode from a detached initrd is described
13031897a969SJaak Ristioja	  in Documentation/x86/microcode.txt. For that you need to enable
13045f9c01aaSBorislav Petkov	  CONFIG_BLK_DEV_INITRD in order for the loader to be able to scan the
13055f9c01aaSBorislav Petkov	  initrd for microcode blobs.
1306506f1d07SSam Ravnborg
1307c508c46eSBenjamin Gilbert	  In addition, you can build the microcode into the kernel. For that you
1308c508c46eSBenjamin Gilbert	  need to add the vendor-supplied microcode to the CONFIG_EXTRA_FIRMWARE
1309c508c46eSBenjamin Gilbert	  config option.
1310506f1d07SSam Ravnborg
13118d86f390SPeter Orubaconfig MICROCODE_INTEL
1312e43f6e67SBorislav Petkov	bool "Intel microcode loading support"
13138d86f390SPeter Oruba	depends on MICROCODE
13148d86f390SPeter Oruba	default MICROCODE
13158d86f390SPeter Oruba	select FW_LOADER
13168f9ca475SIngo Molnar	---help---
13178d86f390SPeter Oruba	  This options enables microcode patch loading support for Intel
13188d86f390SPeter Oruba	  processors.
13198d86f390SPeter Oruba
1320b8989db9SAlan	  For the current Intel microcode data package go to
1321b8989db9SAlan	  <https://downloadcenter.intel.com> and search for
1322b8989db9SAlan	  'Linux Processor Microcode Data File'.
13238d86f390SPeter Oruba
132480cc9f10SPeter Orubaconfig MICROCODE_AMD
1325e43f6e67SBorislav Petkov	bool "AMD microcode loading support"
132680cc9f10SPeter Oruba	depends on MICROCODE
132780cc9f10SPeter Oruba	select FW_LOADER
13288f9ca475SIngo Molnar	---help---
132980cc9f10SPeter Oruba	  If you select this option, microcode patch loading support for AMD
133080cc9f10SPeter Oruba	  processors will be enabled.
133180cc9f10SPeter Oruba
1332506f1d07SSam Ravnborgconfig MICROCODE_OLD_INTERFACE
13333c2362e6SHarvey Harrison	def_bool y
1334506f1d07SSam Ravnborg	depends on MICROCODE
1335506f1d07SSam Ravnborg
1336506f1d07SSam Ravnborgconfig X86_MSR
1337506f1d07SSam Ravnborg	tristate "/dev/cpu/*/msr - Model-specific register support"
13388f9ca475SIngo Molnar	---help---
1339506f1d07SSam Ravnborg	  This device gives privileged processes access to the x86
1340506f1d07SSam Ravnborg	  Model-Specific Registers (MSRs).  It is a character device with
1341506f1d07SSam Ravnborg	  major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr.
1342506f1d07SSam Ravnborg	  MSR accesses are directed to a specific CPU on multi-processor
1343506f1d07SSam Ravnborg	  systems.
1344506f1d07SSam Ravnborg
1345506f1d07SSam Ravnborgconfig X86_CPUID
1346506f1d07SSam Ravnborg	tristate "/dev/cpu/*/cpuid - CPU information support"
13478f9ca475SIngo Molnar	---help---
1348506f1d07SSam Ravnborg	  This device gives processes access to the x86 CPUID instruction to
1349506f1d07SSam Ravnborg	  be executed on a specific processor.  It is a character device
1350506f1d07SSam Ravnborg	  with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to
1351506f1d07SSam Ravnborg	  /dev/cpu/31/cpuid.
1352506f1d07SSam Ravnborg
1353506f1d07SSam Ravnborgchoice
1354506f1d07SSam Ravnborg	prompt "High Memory Support"
13556fc108a0SJan Beulich	default HIGHMEM4G
1356506f1d07SSam Ravnborg	depends on X86_32
1357506f1d07SSam Ravnborg
1358506f1d07SSam Ravnborgconfig NOHIGHMEM
1359506f1d07SSam Ravnborg	bool "off"
1360506f1d07SSam Ravnborg	---help---
1361506f1d07SSam Ravnborg	  Linux can use up to 64 Gigabytes of physical memory on x86 systems.
1362506f1d07SSam Ravnborg	  However, the address space of 32-bit x86 processors is only 4
1363506f1d07SSam Ravnborg	  Gigabytes large. That means that, if you have a large amount of
1364506f1d07SSam Ravnborg	  physical memory, not all of it can be "permanently mapped" by the
1365506f1d07SSam Ravnborg	  kernel. The physical memory that's not permanently mapped is called
1366506f1d07SSam Ravnborg	  "high memory".
1367506f1d07SSam Ravnborg
1368506f1d07SSam Ravnborg	  If you are compiling a kernel which will never run on a machine with
1369506f1d07SSam Ravnborg	  more than 1 Gigabyte total physical RAM, answer "off" here (default
1370506f1d07SSam Ravnborg	  choice and suitable for most users). This will result in a "3GB/1GB"
1371506f1d07SSam Ravnborg	  split: 3GB are mapped so that each process sees a 3GB virtual memory
1372506f1d07SSam Ravnborg	  space and the remaining part of the 4GB virtual memory space is used
1373506f1d07SSam Ravnborg	  by the kernel to permanently map as much physical memory as
1374506f1d07SSam Ravnborg	  possible.
1375506f1d07SSam Ravnborg
1376506f1d07SSam Ravnborg	  If the machine has between 1 and 4 Gigabytes physical RAM, then
1377506f1d07SSam Ravnborg	  answer "4GB" here.
1378506f1d07SSam Ravnborg
1379506f1d07SSam Ravnborg	  If more than 4 Gigabytes is used then answer "64GB" here. This
1380506f1d07SSam Ravnborg	  selection turns Intel PAE (Physical Address Extension) mode on.
1381506f1d07SSam Ravnborg	  PAE implements 3-level paging on IA32 processors. PAE is fully
1382506f1d07SSam Ravnborg	  supported by Linux, PAE mode is implemented on all recent Intel
1383506f1d07SSam Ravnborg	  processors (Pentium Pro and better). NOTE: If you say "64GB" here,
1384506f1d07SSam Ravnborg	  then the kernel will not boot on CPUs that don't support PAE!
1385506f1d07SSam Ravnborg
1386506f1d07SSam Ravnborg	  The actual amount of total physical memory will either be
1387506f1d07SSam Ravnborg	  auto detected or can be forced by using a kernel command line option
1388506f1d07SSam Ravnborg	  such as "mem=256M". (Try "man bootparam" or see the documentation of
1389506f1d07SSam Ravnborg	  your boot loader (lilo or loadlin) about how to pass options to the
1390506f1d07SSam Ravnborg	  kernel at boot time.)
1391506f1d07SSam Ravnborg
1392506f1d07SSam Ravnborg	  If unsure, say "off".
1393506f1d07SSam Ravnborg
1394506f1d07SSam Ravnborgconfig HIGHMEM4G
1395506f1d07SSam Ravnborg	bool "4GB"
13968f9ca475SIngo Molnar	---help---
1397506f1d07SSam Ravnborg	  Select this if you have a 32-bit processor and between 1 and 4
1398506f1d07SSam Ravnborg	  gigabytes of physical RAM.
1399506f1d07SSam Ravnborg
1400506f1d07SSam Ravnborgconfig HIGHMEM64G
1401506f1d07SSam Ravnborg	bool "64GB"
140269b8d3fcSMatthew Whitehead	depends on !M486 && !M586 && !M586TSC && !M586MMX && !MGEODE_LX && !MGEODEGX1 && !MCYRIXIII && !MELAN && !MWINCHIPC6 && !WINCHIP3D && !MK6
1403506f1d07SSam Ravnborg	select X86_PAE
14048f9ca475SIngo Molnar	---help---
1405506f1d07SSam Ravnborg	  Select this if you have a 32-bit processor and more than 4
1406506f1d07SSam Ravnborg	  gigabytes of physical RAM.
1407506f1d07SSam Ravnborg
1408506f1d07SSam Ravnborgendchoice
1409506f1d07SSam Ravnborg
1410506f1d07SSam Ravnborgchoice
14116a108a14SDavid Rientjes	prompt "Memory split" if EXPERT
1412506f1d07SSam Ravnborg	default VMSPLIT_3G
1413506f1d07SSam Ravnborg	depends on X86_32
14148f9ca475SIngo Molnar	---help---
1415506f1d07SSam Ravnborg	  Select the desired split between kernel and user memory.
1416506f1d07SSam Ravnborg
1417506f1d07SSam Ravnborg	  If the address range available to the kernel is less than the
1418506f1d07SSam Ravnborg	  physical memory installed, the remaining memory will be available
1419506f1d07SSam Ravnborg	  as "high memory". Accessing high memory is a little more costly
1420506f1d07SSam Ravnborg	  than low memory, as it needs to be mapped into the kernel first.
1421506f1d07SSam Ravnborg	  Note that increasing the kernel address space limits the range
1422506f1d07SSam Ravnborg	  available to user programs, making the address space there
1423506f1d07SSam Ravnborg	  tighter.  Selecting anything other than the default 3G/1G split
1424506f1d07SSam Ravnborg	  will also likely make your kernel incompatible with binary-only
1425506f1d07SSam Ravnborg	  kernel modules.
1426506f1d07SSam Ravnborg
1427506f1d07SSam Ravnborg	  If you are not absolutely sure what you are doing, leave this
1428506f1d07SSam Ravnborg	  option alone!
1429506f1d07SSam Ravnborg
1430506f1d07SSam Ravnborg	config VMSPLIT_3G
1431506f1d07SSam Ravnborg		bool "3G/1G user/kernel split"
1432506f1d07SSam Ravnborg	config VMSPLIT_3G_OPT
1433506f1d07SSam Ravnborg		depends on !X86_PAE
1434506f1d07SSam Ravnborg		bool "3G/1G user/kernel split (for full 1G low memory)"
1435506f1d07SSam Ravnborg	config VMSPLIT_2G
1436506f1d07SSam Ravnborg		bool "2G/2G user/kernel split"
1437506f1d07SSam Ravnborg	config VMSPLIT_2G_OPT
1438506f1d07SSam Ravnborg		depends on !X86_PAE
1439506f1d07SSam Ravnborg		bool "2G/2G user/kernel split (for full 2G low memory)"
1440506f1d07SSam Ravnborg	config VMSPLIT_1G
1441506f1d07SSam Ravnborg		bool "1G/3G user/kernel split"
1442506f1d07SSam Ravnborgendchoice
1443506f1d07SSam Ravnborg
1444506f1d07SSam Ravnborgconfig PAGE_OFFSET
1445506f1d07SSam Ravnborg	hex
1446506f1d07SSam Ravnborg	default 0xB0000000 if VMSPLIT_3G_OPT
1447506f1d07SSam Ravnborg	default 0x80000000 if VMSPLIT_2G
1448506f1d07SSam Ravnborg	default 0x78000000 if VMSPLIT_2G_OPT
1449506f1d07SSam Ravnborg	default 0x40000000 if VMSPLIT_1G
1450506f1d07SSam Ravnborg	default 0xC0000000
1451506f1d07SSam Ravnborg	depends on X86_32
1452506f1d07SSam Ravnborg
1453506f1d07SSam Ravnborgconfig HIGHMEM
14543c2362e6SHarvey Harrison	def_bool y
1455506f1d07SSam Ravnborg	depends on X86_32 && (HIGHMEM64G || HIGHMEM4G)
1456506f1d07SSam Ravnborg
1457506f1d07SSam Ravnborgconfig X86_PAE
14589ba16087SJan Beulich	bool "PAE (Physical Address Extension) Support"
1459506f1d07SSam Ravnborg	depends on X86_32 && !HIGHMEM4G
1460d4a451d5SChristoph Hellwig	select PHYS_ADDR_T_64BIT
14619d99c712SChristian Melki	select SWIOTLB
14628f9ca475SIngo Molnar	---help---
1463506f1d07SSam Ravnborg	  PAE is required for NX support, and furthermore enables
1464506f1d07SSam Ravnborg	  larger swapspace support for non-overcommit purposes. It
1465506f1d07SSam Ravnborg	  has the cost of more pagetable lookup overhead, and also
1466506f1d07SSam Ravnborg	  consumes more pagetable space per process.
1467506f1d07SSam Ravnborg
146877ef56e4SKirill A. Shutemovconfig X86_5LEVEL
146977ef56e4SKirill A. Shutemov	bool "Enable 5-level page tables support"
1470eedb92abSKirill A. Shutemov	select DYNAMIC_MEMORY_LAYOUT
1471162434e7SKirill A. Shutemov	select SPARSEMEM_VMEMMAP
147277ef56e4SKirill A. Shutemov	depends on X86_64
147377ef56e4SKirill A. Shutemov	---help---
147477ef56e4SKirill A. Shutemov	  5-level paging enables access to larger address space:
147577ef56e4SKirill A. Shutemov	  upto 128 PiB of virtual address space and 4 PiB of
147677ef56e4SKirill A. Shutemov	  physical address space.
147777ef56e4SKirill A. Shutemov
147877ef56e4SKirill A. Shutemov	  It will be supported by future Intel CPUs.
147977ef56e4SKirill A. Shutemov
14806657fca0SKirill A. Shutemov	  A kernel with the option enabled can be booted on machines that
14816657fca0SKirill A. Shutemov	  support 4- or 5-level paging.
148277ef56e4SKirill A. Shutemov
148377ef56e4SKirill A. Shutemov	  See Documentation/x86/x86_64/5level-paging.txt for more
148477ef56e4SKirill A. Shutemov	  information.
148577ef56e4SKirill A. Shutemov
148677ef56e4SKirill A. Shutemov	  Say N if unsure.
148777ef56e4SKirill A. Shutemov
148810971ab2SIngo Molnarconfig X86_DIRECT_GBPAGES
1489e5008abeSLuis R. Rodriguez	def_bool y
14904675ff05SLevin, Alexander (Sasha Levin)	depends on X86_64 && !DEBUG_PAGEALLOC
14918f9ca475SIngo Molnar	---help---
149210971ab2SIngo Molnar	  Certain kernel features effectively disable kernel
149310971ab2SIngo Molnar	  linear 1 GB mappings (even if the CPU otherwise
149410971ab2SIngo Molnar	  supports them), so don't confuse the user by printing
149510971ab2SIngo Molnar	  that we have them enabled.
14969e899816SNick Piggin
14975c280cf6SThomas Gleixnerconfig X86_CPA_STATISTICS
14985c280cf6SThomas Gleixner	bool "Enable statistic for Change Page Attribute"
14995c280cf6SThomas Gleixner	depends on DEBUG_FS
15005c280cf6SThomas Gleixner	---help---
15015c280cf6SThomas Gleixner	  Expose statistics about the Change Page Attribute mechanims, which
15025c280cf6SThomas Gleixner	  helps to determine the effectivness of preserving large and huge
15035c280cf6SThomas Gleixner	  page mappings when mapping protections are changed.
15045c280cf6SThomas Gleixner
15057744ccdbSTom Lendackyconfig ARCH_HAS_MEM_ENCRYPT
15067744ccdbSTom Lendacky	def_bool y
15077744ccdbSTom Lendacky
15087744ccdbSTom Lendackyconfig AMD_MEM_ENCRYPT
15097744ccdbSTom Lendacky	bool "AMD Secure Memory Encryption (SME) support"
15107744ccdbSTom Lendacky	depends on X86_64 && CPU_SUP_AMD
151194d49eb3SKirill A. Shutemov	select DYNAMIC_PHYSICAL_MASK
1512ce9084baSArd Biesheuvel	select ARCH_USE_MEMREMAP_PROT
15137744ccdbSTom Lendacky	---help---
15147744ccdbSTom Lendacky	  Say yes to enable support for the encryption of system memory.
15157744ccdbSTom Lendacky	  This requires an AMD processor that supports Secure Memory
15167744ccdbSTom Lendacky	  Encryption (SME).
15177744ccdbSTom Lendacky
15187744ccdbSTom Lendackyconfig AMD_MEM_ENCRYPT_ACTIVE_BY_DEFAULT
15197744ccdbSTom Lendacky	bool "Activate AMD Secure Memory Encryption (SME) by default"
15207744ccdbSTom Lendacky	default y
15217744ccdbSTom Lendacky	depends on AMD_MEM_ENCRYPT
15227744ccdbSTom Lendacky	---help---
15237744ccdbSTom Lendacky	  Say yes to have system memory encrypted by default if running on
15247744ccdbSTom Lendacky	  an AMD processor that supports Secure Memory Encryption (SME).
15257744ccdbSTom Lendacky
15267744ccdbSTom Lendacky	  If set to Y, then the encryption of system memory can be
15277744ccdbSTom Lendacky	  deactivated with the mem_encrypt=off command line option.
15287744ccdbSTom Lendacky
15297744ccdbSTom Lendacky	  If set to N, then the encryption of system memory can be
15307744ccdbSTom Lendacky	  activated with the mem_encrypt=on command line option.
15317744ccdbSTom Lendacky
1532506f1d07SSam Ravnborg# Common NUMA Features
1533506f1d07SSam Ravnborgconfig NUMA
1534fd51b2d7SKOSAKI Motohiro	bool "Numa Memory Allocation and Scheduler Support"
1535506f1d07SSam Ravnborg	depends on SMP
1536b5660ba7SH. Peter Anvin	depends on X86_64 || (X86_32 && HIGHMEM64G && X86_BIGSMP)
1537b5660ba7SH. Peter Anvin	default y if X86_BIGSMP
15388f9ca475SIngo Molnar	---help---
1539506f1d07SSam Ravnborg	  Enable NUMA (Non Uniform Memory Access) support.
1540fd51b2d7SKOSAKI Motohiro
1541506f1d07SSam Ravnborg	  The kernel will try to allocate memory used by a CPU on the
1542506f1d07SSam Ravnborg	  local memory controller of the CPU and add some more
1543506f1d07SSam Ravnborg	  NUMA awareness to the kernel.
1544506f1d07SSam Ravnborg
1545c280ea5eSIngo Molnar	  For 64-bit this is recommended if the system is Intel Core i7
1546fd51b2d7SKOSAKI Motohiro	  (or later), AMD Opteron, or EM64T NUMA.
1547fd51b2d7SKOSAKI Motohiro
1548b5660ba7SH. Peter Anvin	  For 32-bit this is only needed if you boot a 32-bit
15497cf6c945SDavid Rientjes	  kernel on a 64-bit NUMA platform.
1550fd51b2d7SKOSAKI Motohiro
1551fd51b2d7SKOSAKI Motohiro	  Otherwise, you should say N.
1552506f1d07SSam Ravnborg
1553eec1d4faSHans Rosenfeldconfig AMD_NUMA
15543c2362e6SHarvey Harrison	def_bool y
15553c2362e6SHarvey Harrison	prompt "Old style AMD Opteron NUMA detection"
15565da0ef9aSTejun Heo	depends on X86_64 && NUMA && PCI
15578f9ca475SIngo Molnar	---help---
1558eec1d4faSHans Rosenfeld	  Enable AMD NUMA node topology detection.  You should say Y here if
1559eec1d4faSHans Rosenfeld	  you have a multi processor AMD system. This uses an old method to
1560eec1d4faSHans Rosenfeld	  read the NUMA configuration directly from the builtin Northbridge
1561eec1d4faSHans Rosenfeld	  of Opteron. It is recommended to use X86_64_ACPI_NUMA instead,
1562eec1d4faSHans Rosenfeld	  which also takes priority if both are compiled in.
1563506f1d07SSam Ravnborg
1564506f1d07SSam Ravnborgconfig X86_64_ACPI_NUMA
15653c2362e6SHarvey Harrison	def_bool y
15663c2362e6SHarvey Harrison	prompt "ACPI NUMA detection"
1567506f1d07SSam Ravnborg	depends on X86_64 && NUMA && ACPI && PCI
1568506f1d07SSam Ravnborg	select ACPI_NUMA
15698f9ca475SIngo Molnar	---help---
1570506f1d07SSam Ravnborg	  Enable ACPI SRAT based node topology detection.
1571506f1d07SSam Ravnborg
15726ec6e0d9SSuresh Siddha# Some NUMA nodes have memory ranges that span
15736ec6e0d9SSuresh Siddha# other nodes.  Even though a pfn is valid and
15746ec6e0d9SSuresh Siddha# between a node's start and end pfns, it may not
15756ec6e0d9SSuresh Siddha# reside on that node.  See memmap_init_zone()
15766ec6e0d9SSuresh Siddha# for details.
15776ec6e0d9SSuresh Siddhaconfig NODES_SPAN_OTHER_NODES
15786ec6e0d9SSuresh Siddha	def_bool y
15796ec6e0d9SSuresh Siddha	depends on X86_64_ACPI_NUMA
15806ec6e0d9SSuresh Siddha
1581506f1d07SSam Ravnborgconfig NUMA_EMU
1582506f1d07SSam Ravnborg	bool "NUMA emulation"
15831b7e03efSTejun Heo	depends on NUMA
15848f9ca475SIngo Molnar	---help---
1585506f1d07SSam Ravnborg	  Enable NUMA emulation. A flat machine will be split
1586506f1d07SSam Ravnborg	  into virtual nodes when booted with "numa=fake=N", where N is the
1587506f1d07SSam Ravnborg	  number of nodes. This is only useful for debugging.
1588506f1d07SSam Ravnborg
1589506f1d07SSam Ravnborgconfig NODES_SHIFT
1590d25e26b6SLinus Torvalds	int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP
159151591e31SDavid Rientjes	range 1 10
159251591e31SDavid Rientjes	default "10" if MAXSMP
1593506f1d07SSam Ravnborg	default "6" if X86_64
1594506f1d07SSam Ravnborg	default "3"
1595506f1d07SSam Ravnborg	depends on NEED_MULTIPLE_NODES
15968f9ca475SIngo Molnar	---help---
15971184dc2fSMike Travis	  Specify the maximum number of NUMA Nodes available on the target
1598692105b8SMatt LaPlante	  system.  Increases memory reserved to accommodate various tables.
1599506f1d07SSam Ravnborg
1600506f1d07SSam Ravnborgconfig ARCH_HAVE_MEMORY_PRESENT
16013c2362e6SHarvey Harrison	def_bool y
1602506f1d07SSam Ravnborg	depends on X86_32 && DISCONTIGMEM
1603506f1d07SSam Ravnborg
1604506f1d07SSam Ravnborgconfig ARCH_FLATMEM_ENABLE
1605506f1d07SSam Ravnborg	def_bool y
16063b16651fSTejun Heo	depends on X86_32 && !NUMA
1607506f1d07SSam Ravnborg
1608506f1d07SSam Ravnborgconfig ARCH_DISCONTIGMEM_ENABLE
1609506f1d07SSam Ravnborg	def_bool y
1610b263295dSChristoph Lameter	depends on NUMA && X86_32
1611506f1d07SSam Ravnborg
1612506f1d07SSam Ravnborgconfig ARCH_SPARSEMEM_ENABLE
1613506f1d07SSam Ravnborg	def_bool y
16146ea30386SKees Cook	depends on X86_64 || NUMA || X86_32 || X86_32_NON_STANDARD
1615506f1d07SSam Ravnborg	select SPARSEMEM_STATIC if X86_32
1616506f1d07SSam Ravnborg	select SPARSEMEM_VMEMMAP_ENABLE if X86_64
1617506f1d07SSam Ravnborg
16183b16651fSTejun Heoconfig ARCH_SPARSEMEM_DEFAULT
1619*6ad57f7fSMike Rapoport	def_bool X86_64 || (NUMA && X86_32)
16203b16651fSTejun Heo
1621506f1d07SSam Ravnborgconfig ARCH_SELECT_MEMORY_MODEL
1622506f1d07SSam Ravnborg	def_bool y
1623b263295dSChristoph Lameter	depends on ARCH_SPARSEMEM_ENABLE
1624506f1d07SSam Ravnborg
1625506f1d07SSam Ravnborgconfig ARCH_MEMORY_PROBE
1626a0842b70SToshi Kani	bool "Enable sysfs memory/probe interface"
16273120e25eSJan Beulich	depends on X86_64 && MEMORY_HOTPLUG
1628a0842b70SToshi Kani	help
1629a0842b70SToshi Kani	  This option enables a sysfs memory/probe interface for testing.
1630a0842b70SToshi Kani	  See Documentation/memory-hotplug.txt for more information.
1631a0842b70SToshi Kani	  If you are unsure how to answer this question, answer N.
1632506f1d07SSam Ravnborg
16333b16651fSTejun Heoconfig ARCH_PROC_KCORE_TEXT
16343b16651fSTejun Heo	def_bool y
16353b16651fSTejun Heo	depends on X86_64 && PROC_KCORE
16363b16651fSTejun Heo
1637a29815a3SAvi Kivityconfig ILLEGAL_POINTER_VALUE
1638a29815a3SAvi Kivity       hex
1639a29815a3SAvi Kivity       default 0 if X86_32
1640a29815a3SAvi Kivity       default 0xdead000000000000 if X86_64
1641a29815a3SAvi Kivity
16427a67832cSDan Williamsconfig X86_PMEM_LEGACY_DEVICE
16437a67832cSDan Williams	bool
16447a67832cSDan Williams
1645ec776ef6SChristoph Hellwigconfig X86_PMEM_LEGACY
16467a67832cSDan Williams	tristate "Support non-standard NVDIMMs and ADR protected memory"
16479f53f9faSDan Williams	depends on PHYS_ADDR_T_64BIT
16489f53f9faSDan Williams	depends on BLK_DEV
16497a67832cSDan Williams	select X86_PMEM_LEGACY_DEVICE
16509f53f9faSDan Williams	select LIBNVDIMM
1651ec776ef6SChristoph Hellwig	help
1652ec776ef6SChristoph Hellwig	  Treat memory marked using the non-standard e820 type of 12 as used
1653ec776ef6SChristoph Hellwig	  by the Intel Sandy Bridge-EP reference BIOS as protected memory.
1654ec776ef6SChristoph Hellwig	  The kernel will offer these regions to the 'pmem' driver so
1655ec776ef6SChristoph Hellwig	  they can be used for persistent storage.
1656ec776ef6SChristoph Hellwig
1657ec776ef6SChristoph Hellwig	  Say Y if unsure.
1658ec776ef6SChristoph Hellwig
1659506f1d07SSam Ravnborgconfig HIGHPTE
1660506f1d07SSam Ravnborg	bool "Allocate 3rd-level pagetables from highmem"
16616fc108a0SJan Beulich	depends on HIGHMEM
16628f9ca475SIngo Molnar	---help---
1663506f1d07SSam Ravnborg	  The VM uses one page table entry for each page of physical memory.
1664506f1d07SSam Ravnborg	  For systems with a lot of RAM, this can be wasteful of precious
1665506f1d07SSam Ravnborg	  low memory.  Setting this option will put user-space page table
1666506f1d07SSam Ravnborg	  entries in high memory.
1667506f1d07SSam Ravnborg
16689f077871SJeremy Fitzhardingeconfig X86_CHECK_BIOS_CORRUPTION
16699f077871SJeremy Fitzhardinge	bool "Check for low memory corruption"
16708f9ca475SIngo Molnar	---help---
16719f077871SJeremy Fitzhardinge	  Periodically check for memory corruption in low memory, which
16729f077871SJeremy Fitzhardinge	  is suspected to be caused by BIOS.  Even when enabled in the
16739f077871SJeremy Fitzhardinge	  configuration, it is disabled at runtime.  Enable it by
16749f077871SJeremy Fitzhardinge	  setting "memory_corruption_check=1" on the kernel command
16759f077871SJeremy Fitzhardinge	  line.  By default it scans the low 64k of memory every 60
16769f077871SJeremy Fitzhardinge	  seconds; see the memory_corruption_check_size and
16779f077871SJeremy Fitzhardinge	  memory_corruption_check_period parameters in
16788c27ceffSMauro Carvalho Chehab	  Documentation/admin-guide/kernel-parameters.rst to adjust this.
16799f077871SJeremy Fitzhardinge
16809f077871SJeremy Fitzhardinge	  When enabled with the default parameters, this option has
16819f077871SJeremy Fitzhardinge	  almost no overhead, as it reserves a relatively small amount
16829f077871SJeremy Fitzhardinge	  of memory and scans it infrequently.  It both detects corruption
16839f077871SJeremy Fitzhardinge	  and prevents it from affecting the running system.
16849f077871SJeremy Fitzhardinge
16859f077871SJeremy Fitzhardinge	  It is, however, intended as a diagnostic tool; if repeatable
16869f077871SJeremy Fitzhardinge	  BIOS-originated corruption always affects the same memory,
16879f077871SJeremy Fitzhardinge	  you can use memmap= to prevent the kernel from using that
16889f077871SJeremy Fitzhardinge	  memory.
16899f077871SJeremy Fitzhardinge
1690c885df50SJeremy Fitzhardingeconfig X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK
1691c885df50SJeremy Fitzhardinge	bool "Set the default setting of memory_corruption_check"
1692c885df50SJeremy Fitzhardinge	depends on X86_CHECK_BIOS_CORRUPTION
1693c885df50SJeremy Fitzhardinge	default y
16948f9ca475SIngo Molnar	---help---
1695c885df50SJeremy Fitzhardinge	  Set whether the default state of memory_corruption_check is
1696c885df50SJeremy Fitzhardinge	  on or off.
1697c885df50SJeremy Fitzhardinge
16989ea77bdbSH. Peter Anvinconfig X86_RESERVE_LOW
1699d0cd7425SH. Peter Anvin	int "Amount of low memory, in kilobytes, to reserve for the BIOS"
1700d0cd7425SH. Peter Anvin	default 64
1701d0cd7425SH. Peter Anvin	range 4 640
17028f9ca475SIngo Molnar	---help---
1703d0cd7425SH. Peter Anvin	  Specify the amount of low memory to reserve for the BIOS.
1704fc381519SIngo Molnar
1705d0cd7425SH. Peter Anvin	  The first page contains BIOS data structures that the kernel
1706d0cd7425SH. Peter Anvin	  must not use, so that page must always be reserved.
1707fc381519SIngo Molnar
1708d0cd7425SH. Peter Anvin	  By default we reserve the first 64K of physical RAM, as a
1709d0cd7425SH. Peter Anvin	  number of BIOSes are known to corrupt that memory range
1710d0cd7425SH. Peter Anvin	  during events such as suspend/resume or monitor cable
1711d0cd7425SH. Peter Anvin	  insertion, so it must not be used by the kernel.
1712fc381519SIngo Molnar
1713d0cd7425SH. Peter Anvin	  You can set this to 4 if you are absolutely sure that you
1714d0cd7425SH. Peter Anvin	  trust the BIOS to get all its memory reservations and usages
1715d0cd7425SH. Peter Anvin	  right.  If you know your BIOS have problems beyond the
1716d0cd7425SH. Peter Anvin	  default 64K area, you can set this to 640 to avoid using the
1717d0cd7425SH. Peter Anvin	  entire low memory range.
1718d0cd7425SH. Peter Anvin
1719d0cd7425SH. Peter Anvin	  If you have doubts about the BIOS (e.g. suspend/resume does
1720d0cd7425SH. Peter Anvin	  not work or there's kernel crashes after certain hardware
1721d0cd7425SH. Peter Anvin	  hotplug events) then you might want to enable
1722d0cd7425SH. Peter Anvin	  X86_CHECK_BIOS_CORRUPTION=y to allow the kernel to check
1723d0cd7425SH. Peter Anvin	  typical corruption patterns.
1724d0cd7425SH. Peter Anvin
1725d0cd7425SH. Peter Anvin	  Leave this to the default value of 64 if you are unsure.
1726fc381519SIngo Molnar
1727506f1d07SSam Ravnborgconfig MATH_EMULATION
1728506f1d07SSam Ravnborg	bool
1729a5b9e5a2SAndy Lutomirski	depends on MODIFY_LDT_SYSCALL
1730506f1d07SSam Ravnborg	prompt "Math emulation" if X86_32
1731506f1d07SSam Ravnborg	---help---
1732506f1d07SSam Ravnborg	  Linux can emulate a math coprocessor (used for floating point
1733506f1d07SSam Ravnborg	  operations) if you don't have one. 486DX and Pentium processors have
1734506f1d07SSam Ravnborg	  a math coprocessor built in, 486SX and 386 do not, unless you added
1735506f1d07SSam Ravnborg	  a 487DX or 387, respectively. (The messages during boot time can
1736506f1d07SSam Ravnborg	  give you some hints here ["man dmesg"].) Everyone needs either a
1737506f1d07SSam Ravnborg	  coprocessor or this emulation.
1738506f1d07SSam Ravnborg
1739506f1d07SSam Ravnborg	  If you don't have a math coprocessor, you need to say Y here; if you
1740506f1d07SSam Ravnborg	  say Y here even though you have a coprocessor, the coprocessor will
1741506f1d07SSam Ravnborg	  be used nevertheless. (This behavior can be changed with the kernel
1742506f1d07SSam Ravnborg	  command line option "no387", which comes handy if your coprocessor
1743506f1d07SSam Ravnborg	  is broken. Try "man bootparam" or see the documentation of your boot
1744506f1d07SSam Ravnborg	  loader (lilo or loadlin) about how to pass options to the kernel at
1745506f1d07SSam Ravnborg	  boot time.) This means that it is a good idea to say Y here if you
1746506f1d07SSam Ravnborg	  intend to use this kernel on different machines.
1747506f1d07SSam Ravnborg
1748506f1d07SSam Ravnborg	  More information about the internals of the Linux math coprocessor
1749506f1d07SSam Ravnborg	  emulation can be found in <file:arch/x86/math-emu/README>.
1750506f1d07SSam Ravnborg
1751506f1d07SSam Ravnborg	  If you are not sure, say Y; apart from resulting in a 66 KB bigger
1752506f1d07SSam Ravnborg	  kernel, it won't hurt.
1753506f1d07SSam Ravnborg
1754506f1d07SSam Ravnborgconfig MTRR
17556fc108a0SJan Beulich	def_bool y
17566a108a14SDavid Rientjes	prompt "MTRR (Memory Type Range Register) support" if EXPERT
1757506f1d07SSam Ravnborg	---help---
1758506f1d07SSam Ravnborg	  On Intel P6 family processors (Pentium Pro, Pentium II and later)
1759506f1d07SSam Ravnborg	  the Memory Type Range Registers (MTRRs) may be used to control
1760506f1d07SSam Ravnborg	  processor access to memory ranges. This is most useful if you have
1761506f1d07SSam Ravnborg	  a video (VGA) card on a PCI or AGP bus. Enabling write-combining
1762506f1d07SSam Ravnborg	  allows bus write transfers to be combined into a larger transfer
1763506f1d07SSam Ravnborg	  before bursting over the PCI/AGP bus. This can increase performance
1764506f1d07SSam Ravnborg	  of image write operations 2.5 times or more. Saying Y here creates a
1765506f1d07SSam Ravnborg	  /proc/mtrr file which may be used to manipulate your processor's
1766506f1d07SSam Ravnborg	  MTRRs. Typically the X server should use this.
1767506f1d07SSam Ravnborg
1768506f1d07SSam Ravnborg	  This code has a reasonably generic interface so that similar
1769506f1d07SSam Ravnborg	  control registers on other processors can be easily supported
1770506f1d07SSam Ravnborg	  as well:
1771506f1d07SSam Ravnborg
1772506f1d07SSam Ravnborg	  The Cyrix 6x86, 6x86MX and M II processors have Address Range
1773506f1d07SSam Ravnborg	  Registers (ARRs) which provide a similar functionality to MTRRs. For
1774506f1d07SSam Ravnborg	  these, the ARRs are used to emulate the MTRRs.
1775506f1d07SSam Ravnborg	  The AMD K6-2 (stepping 8 and above) and K6-3 processors have two
1776506f1d07SSam Ravnborg	  MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing
1777506f1d07SSam Ravnborg	  write-combining. All of these processors are supported by this code
1778506f1d07SSam Ravnborg	  and it makes sense to say Y here if you have one of them.
1779506f1d07SSam Ravnborg
1780506f1d07SSam Ravnborg	  Saying Y here also fixes a problem with buggy SMP BIOSes which only
1781506f1d07SSam Ravnborg	  set the MTRRs for the boot CPU and not for the secondary CPUs. This
1782506f1d07SSam Ravnborg	  can lead to all sorts of problems, so it's good to say Y here.
1783506f1d07SSam Ravnborg
1784506f1d07SSam Ravnborg	  You can safely say Y even if your machine doesn't have MTRRs, you'll
1785506f1d07SSam Ravnborg	  just add about 9 KB to your kernel.
1786506f1d07SSam Ravnborg
17877225e751SRandy Dunlap	  See <file:Documentation/x86/mtrr.txt> for more information.
1788506f1d07SSam Ravnborg
178995ffa243SYinghai Luconfig MTRR_SANITIZER
17902ffb3501SYinghai Lu	def_bool y
179195ffa243SYinghai Lu	prompt "MTRR cleanup support"
179295ffa243SYinghai Lu	depends on MTRR
17938f9ca475SIngo Molnar	---help---
1794aba3728cSThomas Gleixner	  Convert MTRR layout from continuous to discrete, so X drivers can
1795aba3728cSThomas Gleixner	  add writeback entries.
179695ffa243SYinghai Lu
1797aba3728cSThomas Gleixner	  Can be disabled with disable_mtrr_cleanup on the kernel command line.
1798692105b8SMatt LaPlante	  The largest mtrr entry size for a continuous block can be set with
1799aba3728cSThomas Gleixner	  mtrr_chunk_size.
180095ffa243SYinghai Lu
18012ffb3501SYinghai Lu	  If unsure, say Y.
180295ffa243SYinghai Lu
180395ffa243SYinghai Luconfig MTRR_SANITIZER_ENABLE_DEFAULT
1804f5098d62SYinghai Lu	int "MTRR cleanup enable value (0-1)"
1805f5098d62SYinghai Lu	range 0 1
1806f5098d62SYinghai Lu	default "0"
180795ffa243SYinghai Lu	depends on MTRR_SANITIZER
18088f9ca475SIngo Molnar	---help---
1809f5098d62SYinghai Lu	  Enable mtrr cleanup default value
181095ffa243SYinghai Lu
181112031a62SYinghai Luconfig MTRR_SANITIZER_SPARE_REG_NR_DEFAULT
181212031a62SYinghai Lu	int "MTRR cleanup spare reg num (0-7)"
181312031a62SYinghai Lu	range 0 7
181412031a62SYinghai Lu	default "1"
181512031a62SYinghai Lu	depends on MTRR_SANITIZER
18168f9ca475SIngo Molnar	---help---
181712031a62SYinghai Lu	  mtrr cleanup spare entries default, it can be changed via
1818aba3728cSThomas Gleixner	  mtrr_spare_reg_nr=N on the kernel command line.
181912031a62SYinghai Lu
18202e5d9c85Svenkatesh.pallipadi@intel.comconfig X86_PAT
18216fc108a0SJan Beulich	def_bool y
18226a108a14SDavid Rientjes	prompt "x86 PAT support" if EXPERT
18232a8a2719SIngo Molnar	depends on MTRR
18248f9ca475SIngo Molnar	---help---
18252e5d9c85Svenkatesh.pallipadi@intel.com	  Use PAT attributes to setup page level cache control.
1826042b78e4SVenki Pallipadi
18272e5d9c85Svenkatesh.pallipadi@intel.com	  PATs are the modern equivalents of MTRRs and are much more
18282e5d9c85Svenkatesh.pallipadi@intel.com	  flexible than MTRRs.
18292e5d9c85Svenkatesh.pallipadi@intel.com
18302e5d9c85Svenkatesh.pallipadi@intel.com	  Say N here if you see bootup problems (boot crash, boot hang,
1831042b78e4SVenki Pallipadi	  spontaneous reboots) or a non-working video driver.
18322e5d9c85Svenkatesh.pallipadi@intel.com
18332e5d9c85Svenkatesh.pallipadi@intel.com	  If unsure, say Y.
18342e5d9c85Svenkatesh.pallipadi@intel.com
183546cf98cdSVenkatesh Pallipadiconfig ARCH_USES_PG_UNCACHED
183646cf98cdSVenkatesh Pallipadi	def_bool y
183746cf98cdSVenkatesh Pallipadi	depends on X86_PAT
183846cf98cdSVenkatesh Pallipadi
1839628c6246SH. Peter Anvinconfig ARCH_RANDOM
1840628c6246SH. Peter Anvin	def_bool y
1841628c6246SH. Peter Anvin	prompt "x86 architectural random number generator" if EXPERT
1842628c6246SH. Peter Anvin	---help---
1843628c6246SH. Peter Anvin	  Enable the x86 architectural RDRAND instruction
1844628c6246SH. Peter Anvin	  (Intel Bull Mountain technology) to generate random numbers.
1845628c6246SH. Peter Anvin	  If supported, this is a high bandwidth, cryptographically
1846628c6246SH. Peter Anvin	  secure hardware random number generator.
1847628c6246SH. Peter Anvin
184851ae4a2dSH. Peter Anvinconfig X86_SMAP
184951ae4a2dSH. Peter Anvin	def_bool y
185051ae4a2dSH. Peter Anvin	prompt "Supervisor Mode Access Prevention" if EXPERT
185151ae4a2dSH. Peter Anvin	---help---
185251ae4a2dSH. Peter Anvin	  Supervisor Mode Access Prevention (SMAP) is a security
185351ae4a2dSH. Peter Anvin	  feature in newer Intel processors.  There is a small
185451ae4a2dSH. Peter Anvin	  performance cost if this enabled and turned on; there is
185551ae4a2dSH. Peter Anvin	  also a small increase in the kernel size if this is enabled.
185651ae4a2dSH. Peter Anvin
185751ae4a2dSH. Peter Anvin	  If unsure, say Y.
185851ae4a2dSH. Peter Anvin
1859aa35f896SRicardo Nericonfig X86_INTEL_UMIP
1860796ebc81SRicardo Neri	def_bool y
1861aa35f896SRicardo Neri	depends on CPU_SUP_INTEL
1862aa35f896SRicardo Neri	prompt "Intel User Mode Instruction Prevention" if EXPERT
1863aa35f896SRicardo Neri	---help---
1864aa35f896SRicardo Neri	  The User Mode Instruction Prevention (UMIP) is a security
1865aa35f896SRicardo Neri	  feature in newer Intel processors. If enabled, a general
1866796ebc81SRicardo Neri	  protection fault is issued if the SGDT, SLDT, SIDT, SMSW
1867796ebc81SRicardo Neri	  or STR instructions are executed in user mode. These instructions
1868796ebc81SRicardo Neri	  unnecessarily expose information about the hardware state.
1869796ebc81SRicardo Neri
1870796ebc81SRicardo Neri	  The vast majority of applications do not use these instructions.
1871796ebc81SRicardo Neri	  For the very few that do, software emulation is provided in
1872796ebc81SRicardo Neri	  specific cases in protected and virtual-8086 modes. Emulated
1873796ebc81SRicardo Neri	  results are dummy.
1874aa35f896SRicardo Neri
187572e9b5feSDave Hansenconfig X86_INTEL_MPX
187672e9b5feSDave Hansen	prompt "Intel MPX (Memory Protection Extensions)"
187772e9b5feSDave Hansen	def_bool n
1878df3735c5SRik van Riel	# Note: only available in 64-bit mode due to VMA flags shortage
1879df3735c5SRik van Riel	depends on CPU_SUP_INTEL && X86_64
1880df3735c5SRik van Riel	select ARCH_USES_HIGH_VMA_FLAGS
188172e9b5feSDave Hansen	---help---
188272e9b5feSDave Hansen	  MPX provides hardware features that can be used in
188372e9b5feSDave Hansen	  conjunction with compiler-instrumented code to check
188472e9b5feSDave Hansen	  memory references.  It is designed to detect buffer
188572e9b5feSDave Hansen	  overflow or underflow bugs.
188672e9b5feSDave Hansen
188772e9b5feSDave Hansen	  This option enables running applications which are
188872e9b5feSDave Hansen	  instrumented or otherwise use MPX.  It does not use MPX
188972e9b5feSDave Hansen	  itself inside the kernel or to protect the kernel
189072e9b5feSDave Hansen	  against bad memory references.
189172e9b5feSDave Hansen
189272e9b5feSDave Hansen	  Enabling this option will make the kernel larger:
189372e9b5feSDave Hansen	  ~8k of kernel text and 36 bytes of data on a 64-bit
189472e9b5feSDave Hansen	  defconfig.  It adds a long to the 'mm_struct' which
189572e9b5feSDave Hansen	  will increase the kernel memory overhead of each
189672e9b5feSDave Hansen	  process and adds some branches to paths used during
189772e9b5feSDave Hansen	  exec() and munmap().
189872e9b5feSDave Hansen
189972e9b5feSDave Hansen	  For details, see Documentation/x86/intel_mpx.txt
190072e9b5feSDave Hansen
190172e9b5feSDave Hansen	  If unsure, say N.
190272e9b5feSDave Hansen
190335e97790SDave Hansenconfig X86_INTEL_MEMORY_PROTECTION_KEYS
1904284244a9SDave Hansen	prompt "Intel Memory Protection Keys"
190535e97790SDave Hansen	def_bool y
1906284244a9SDave Hansen	# Note: only available in 64-bit mode
190735e97790SDave Hansen	depends on CPU_SUP_INTEL && X86_64
190852c8e601SIngo Molnar	select ARCH_USES_HIGH_VMA_FLAGS
190952c8e601SIngo Molnar	select ARCH_HAS_PKEYS
1910284244a9SDave Hansen	---help---
1911284244a9SDave Hansen	  Memory Protection Keys provides a mechanism for enforcing
1912284244a9SDave Hansen	  page-based protections, but without requiring modification of the
1913284244a9SDave Hansen	  page tables when an application changes protection domains.
1914284244a9SDave Hansen
1915284244a9SDave Hansen	  For details, see Documentation/x86/protection-keys.txt
1916284244a9SDave Hansen
1917284244a9SDave Hansen	  If unsure, say y.
191835e97790SDave Hansen
1919506f1d07SSam Ravnborgconfig EFI
19209ba16087SJan Beulich	bool "EFI runtime service support"
19215b83683fSHuang, Ying	depends on ACPI
1922f6ce5002SSergey Vlasov	select UCS2_STRING
1923022ee6c5SArd Biesheuvel	select EFI_RUNTIME_WRAPPERS
1924506f1d07SSam Ravnborg	---help---
19258b2cb7a8SHuang, Ying	  This enables the kernel to use EFI runtime services that are
1926506f1d07SSam Ravnborg	  available (such as the EFI variable services).
1927506f1d07SSam Ravnborg
19288b2cb7a8SHuang, Ying	  This option is only useful on systems that have EFI firmware.
19298b2cb7a8SHuang, Ying	  In addition, you should use the latest ELILO loader available
19308b2cb7a8SHuang, Ying	  at <http://elilo.sourceforge.net> in order to take advantage
19318b2cb7a8SHuang, Ying	  of EFI runtime services. However, even with this option, the
19328b2cb7a8SHuang, Ying	  resultant kernel should continue to boot on existing non-EFI
19338b2cb7a8SHuang, Ying	  platforms.
1934506f1d07SSam Ravnborg
1935291f3632SMatt Flemingconfig EFI_STUB
1936291f3632SMatt Fleming       bool "EFI stub support"
1937b16d8c23SMatt Fleming       depends on EFI && !X86_USE_3DNOW
19387b2a583aSMatt Fleming       select RELOCATABLE
1939291f3632SMatt Fleming       ---help---
1940291f3632SMatt Fleming          This kernel feature allows a bzImage to be loaded directly
1941291f3632SMatt Fleming	  by EFI firmware without the use of a bootloader.
1942291f3632SMatt Fleming
19434172fe2fSRoy Franz	  See Documentation/efi-stub.txt for more information.
19440c759662SMatt Fleming
19457d453eeeSMatt Flemingconfig EFI_MIXED
19467d453eeeSMatt Fleming	bool "EFI mixed-mode support"
19477d453eeeSMatt Fleming	depends on EFI_STUB && X86_64
19487d453eeeSMatt Fleming	---help---
19497d453eeeSMatt Fleming	   Enabling this feature allows a 64-bit kernel to be booted
19507d453eeeSMatt Fleming	   on a 32-bit firmware, provided that your CPU supports 64-bit
19517d453eeeSMatt Fleming	   mode.
19527d453eeeSMatt Fleming
19537d453eeeSMatt Fleming	   Note that it is not possible to boot a mixed-mode enabled
19547d453eeeSMatt Fleming	   kernel via the EFI boot stub - a bootloader that supports
19557d453eeeSMatt Fleming	   the EFI handover protocol must be used.
19567d453eeeSMatt Fleming
19577d453eeeSMatt Fleming	   If unsure, say N.
19587d453eeeSMatt Fleming
1959506f1d07SSam Ravnborgconfig SECCOMP
19603c2362e6SHarvey Harrison	def_bool y
19613c2362e6SHarvey Harrison	prompt "Enable seccomp to safely compute untrusted bytecode"
19628f9ca475SIngo Molnar	---help---
1963506f1d07SSam Ravnborg	  This kernel feature is useful for number crunching applications
1964506f1d07SSam Ravnborg	  that may need to compute untrusted bytecode during their
1965506f1d07SSam Ravnborg	  execution. By using pipes or other transports made available to
1966506f1d07SSam Ravnborg	  the process as file descriptors supporting the read/write
1967506f1d07SSam Ravnborg	  syscalls, it's possible to isolate those applications in
1968506f1d07SSam Ravnborg	  their own address space using seccomp. Once seccomp is
19699c0bbee8SAlexey Dobriyan	  enabled via prctl(PR_SET_SECCOMP), it cannot be disabled
1970506f1d07SSam Ravnborg	  and the task is only allowed to execute a few safe syscalls
1971506f1d07SSam Ravnborg	  defined by each seccomp mode.
1972506f1d07SSam Ravnborg
1973506f1d07SSam Ravnborg	  If unsure, say Y. Only embedded should say N here.
1974506f1d07SSam Ravnborg
19758636a1f9SMasahiro Yamadasource "kernel/Kconfig.hz"
1976506f1d07SSam Ravnborg
1977506f1d07SSam Ravnborgconfig KEXEC
1978506f1d07SSam Ravnborg	bool "kexec system call"
19792965faa5SDave Young	select KEXEC_CORE
19808f9ca475SIngo Molnar	---help---
1981506f1d07SSam Ravnborg	  kexec is a system call that implements the ability to shutdown your
1982506f1d07SSam Ravnborg	  current kernel, and to start another kernel.  It is like a reboot
1983506f1d07SSam Ravnborg	  but it is independent of the system firmware.   And like a reboot
1984506f1d07SSam Ravnborg	  you can start any kernel with it, not just Linux.
1985506f1d07SSam Ravnborg
1986506f1d07SSam Ravnborg	  The name comes from the similarity to the exec system call.
1987506f1d07SSam Ravnborg
1988506f1d07SSam Ravnborg	  It is an ongoing process to be certain the hardware in a machine
1989506f1d07SSam Ravnborg	  is properly shutdown, so do not be surprised if this code does not
1990bf220695SGeert Uytterhoeven	  initially work for you.  As of this writing the exact hardware
1991bf220695SGeert Uytterhoeven	  interface is strongly in flux, so no good recommendation can be
1992bf220695SGeert Uytterhoeven	  made.
1993506f1d07SSam Ravnborg
199474ca317cSVivek Goyalconfig KEXEC_FILE
199574ca317cSVivek Goyal	bool "kexec file based system call"
19962965faa5SDave Young	select KEXEC_CORE
199774ca317cSVivek Goyal	select BUILD_BIN2C
199874ca317cSVivek Goyal	depends on X86_64
199974ca317cSVivek Goyal	depends on CRYPTO=y
200074ca317cSVivek Goyal	depends on CRYPTO_SHA256=y
200174ca317cSVivek Goyal	---help---
200274ca317cSVivek Goyal	  This is new version of kexec system call. This system call is
200374ca317cSVivek Goyal	  file based and takes file descriptors as system call argument
200474ca317cSVivek Goyal	  for kernel and initramfs as opposed to list of segments as
200574ca317cSVivek Goyal	  accepted by previous system call.
200674ca317cSVivek Goyal
2007b799a09fSAKASHI Takahiroconfig ARCH_HAS_KEXEC_PURGATORY
2008b799a09fSAKASHI Takahiro	def_bool KEXEC_FILE
2009b799a09fSAKASHI Takahiro
20108e7d8381SVivek Goyalconfig KEXEC_VERIFY_SIG
20118e7d8381SVivek Goyal	bool "Verify kernel signature during kexec_file_load() syscall"
201274ca317cSVivek Goyal	depends on KEXEC_FILE
20138e7d8381SVivek Goyal	---help---
20148e7d8381SVivek Goyal	  This option makes kernel signature verification mandatory for
2015d8eb8940SBorislav Petkov	  the kexec_file_load() syscall.
20168e7d8381SVivek Goyal
2017d8eb8940SBorislav Petkov	  In addition to that option, you need to enable signature
2018d8eb8940SBorislav Petkov	  verification for the corresponding kernel image type being
2019d8eb8940SBorislav Petkov	  loaded in order for this to work.
20208e7d8381SVivek Goyal
20218e7d8381SVivek Goyalconfig KEXEC_BZIMAGE_VERIFY_SIG
20228e7d8381SVivek Goyal	bool "Enable bzImage signature verification support"
20238e7d8381SVivek Goyal	depends on KEXEC_VERIFY_SIG
20248e7d8381SVivek Goyal	depends on SIGNED_PE_FILE_VERIFICATION
20258e7d8381SVivek Goyal	select SYSTEM_TRUSTED_KEYRING
20268e7d8381SVivek Goyal	---help---
20278e7d8381SVivek Goyal	  Enable bzImage signature verification support.
20288e7d8381SVivek Goyal
2029506f1d07SSam Ravnborgconfig CRASH_DUMP
203004b69447SPavel Machek	bool "kernel crash dumps"
2031506f1d07SSam Ravnborg	depends on X86_64 || (X86_32 && HIGHMEM)
20328f9ca475SIngo Molnar	---help---
2033506f1d07SSam Ravnborg	  Generate crash dump after being started by kexec.
2034506f1d07SSam Ravnborg	  This should be normally only set in special crash dump kernels
2035506f1d07SSam Ravnborg	  which are loaded in the main kernel with kexec-tools into
2036506f1d07SSam Ravnborg	  a specially reserved region and then later executed after
2037506f1d07SSam Ravnborg	  a crash by kdump/kexec. The crash dump kernel must be compiled
2038506f1d07SSam Ravnborg	  to a memory address not used by the main kernel or BIOS using
2039506f1d07SSam Ravnborg	  PHYSICAL_START, or it must be built as a relocatable image
2040506f1d07SSam Ravnborg	  (CONFIG_RELOCATABLE=y).
2041506f1d07SSam Ravnborg	  For more details see Documentation/kdump/kdump.txt
2042506f1d07SSam Ravnborg
20433ab83521SHuang Yingconfig KEXEC_JUMP
20446ea30386SKees Cook	bool "kexec jump"
2045fee7b0d8SHuang Ying	depends on KEXEC && HIBERNATION
20468f9ca475SIngo Molnar	---help---
204789081d17SHuang Ying	  Jump between original kernel and kexeced kernel and invoke
204889081d17SHuang Ying	  code in physical address mode via KEXEC
20493ab83521SHuang Ying
2050506f1d07SSam Ravnborgconfig PHYSICAL_START
20516a108a14SDavid Rientjes	hex "Physical address where the kernel is loaded" if (EXPERT || CRASH_DUMP)
2052ceefccc9SH. Peter Anvin	default "0x1000000"
20538f9ca475SIngo Molnar	---help---
2054506f1d07SSam Ravnborg	  This gives the physical address where the kernel is loaded.
2055506f1d07SSam Ravnborg
2056506f1d07SSam Ravnborg	  If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then
2057506f1d07SSam Ravnborg	  bzImage will decompress itself to above physical address and
2058506f1d07SSam Ravnborg	  run from there. Otherwise, bzImage will run from the address where
2059506f1d07SSam Ravnborg	  it has been loaded by the boot loader and will ignore above physical
2060506f1d07SSam Ravnborg	  address.
2061506f1d07SSam Ravnborg
2062506f1d07SSam Ravnborg	  In normal kdump cases one does not have to set/change this option
2063506f1d07SSam Ravnborg	  as now bzImage can be compiled as a completely relocatable image
2064506f1d07SSam Ravnborg	  (CONFIG_RELOCATABLE=y) and be used to load and run from a different
2065506f1d07SSam Ravnborg	  address. This option is mainly useful for the folks who don't want
2066506f1d07SSam Ravnborg	  to use a bzImage for capturing the crash dump and want to use a
2067506f1d07SSam Ravnborg	  vmlinux instead. vmlinux is not relocatable hence a kernel needs
2068506f1d07SSam Ravnborg	  to be specifically compiled to run from a specific memory area
2069506f1d07SSam Ravnborg	  (normally a reserved region) and this option comes handy.
2070506f1d07SSam Ravnborg
2071ceefccc9SH. Peter Anvin	  So if you are using bzImage for capturing the crash dump,
2072ceefccc9SH. Peter Anvin	  leave the value here unchanged to 0x1000000 and set
2073ceefccc9SH. Peter Anvin	  CONFIG_RELOCATABLE=y.  Otherwise if you plan to use vmlinux
2074ceefccc9SH. Peter Anvin	  for capturing the crash dump change this value to start of
2075ceefccc9SH. Peter Anvin	  the reserved region.  In other words, it can be set based on
2076ceefccc9SH. Peter Anvin	  the "X" value as specified in the "crashkernel=YM@XM"
2077ceefccc9SH. Peter Anvin	  command line boot parameter passed to the panic-ed
2078ceefccc9SH. Peter Anvin	  kernel. Please take a look at Documentation/kdump/kdump.txt
2079ceefccc9SH. Peter Anvin	  for more details about crash dumps.
2080506f1d07SSam Ravnborg
2081506f1d07SSam Ravnborg	  Usage of bzImage for capturing the crash dump is recommended as
2082506f1d07SSam Ravnborg	  one does not have to build two kernels. Same kernel can be used
2083506f1d07SSam Ravnborg	  as production kernel and capture kernel. Above option should have
2084506f1d07SSam Ravnborg	  gone away after relocatable bzImage support is introduced. But it
2085506f1d07SSam Ravnborg	  is present because there are users out there who continue to use
2086506f1d07SSam Ravnborg	  vmlinux for dump capture. This option should go away down the
2087506f1d07SSam Ravnborg	  line.
2088506f1d07SSam Ravnborg
2089506f1d07SSam Ravnborg	  Don't change this unless you know what you are doing.
2090506f1d07SSam Ravnborg
2091506f1d07SSam Ravnborgconfig RELOCATABLE
209226717808SH. Peter Anvin	bool "Build a relocatable kernel"
209326717808SH. Peter Anvin	default y
20948f9ca475SIngo Molnar	---help---
2095506f1d07SSam Ravnborg	  This builds a kernel image that retains relocation information
2096506f1d07SSam Ravnborg	  so it can be loaded someplace besides the default 1MB.
2097506f1d07SSam Ravnborg	  The relocations tend to make the kernel binary about 10% larger,
2098506f1d07SSam Ravnborg	  but are discarded at runtime.
2099506f1d07SSam Ravnborg
2100506f1d07SSam Ravnborg	  One use is for the kexec on panic case where the recovery kernel
2101506f1d07SSam Ravnborg	  must live at a different physical address than the primary
2102506f1d07SSam Ravnborg	  kernel.
2103506f1d07SSam Ravnborg
2104506f1d07SSam Ravnborg	  Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address
2105506f1d07SSam Ravnborg	  it has been loaded at and the compile time physical address
21068ab3820fSKees Cook	  (CONFIG_PHYSICAL_START) is used as the minimum location.
2107506f1d07SSam Ravnborg
21088ab3820fSKees Cookconfig RANDOMIZE_BASE
2109e8581e3dSBaoquan He	bool "Randomize the address of the kernel image (KASLR)"
21108ab3820fSKees Cook	depends on RELOCATABLE
21116807c846SIngo Molnar	default y
21128ab3820fSKees Cook	---help---
2113e8581e3dSBaoquan He	  In support of Kernel Address Space Layout Randomization (KASLR),
2114e8581e3dSBaoquan He	  this randomizes the physical address at which the kernel image
2115e8581e3dSBaoquan He	  is decompressed and the virtual address where the kernel
2116e8581e3dSBaoquan He	  image is mapped, as a security feature that deters exploit
2117e8581e3dSBaoquan He	  attempts relying on knowledge of the location of kernel
2118e8581e3dSBaoquan He	  code internals.
2119e8581e3dSBaoquan He
2120ed9f007eSKees Cook	  On 64-bit, the kernel physical and virtual addresses are
2121ed9f007eSKees Cook	  randomized separately. The physical address will be anywhere
2122ed9f007eSKees Cook	  between 16MB and the top of physical memory (up to 64TB). The
2123ed9f007eSKees Cook	  virtual address will be randomized from 16MB up to 1GB (9 bits
2124ed9f007eSKees Cook	  of entropy). Note that this also reduces the memory space
2125ed9f007eSKees Cook	  available to kernel modules from 1.5GB to 1GB.
2126ed9f007eSKees Cook
2127ed9f007eSKees Cook	  On 32-bit, the kernel physical and virtual addresses are
2128ed9f007eSKees Cook	  randomized together. They will be randomized from 16MB up to
2129ed9f007eSKees Cook	  512MB (8 bits of entropy).
21308ab3820fSKees Cook
2131a653f356SKees Cook	  Entropy is generated using the RDRAND instruction if it is
2132e8581e3dSBaoquan He	  supported. If RDTSC is supported, its value is mixed into
2133e8581e3dSBaoquan He	  the entropy pool as well. If neither RDRAND nor RDTSC are
2134ed9f007eSKees Cook	  supported, then entropy is read from the i8254 timer. The
2135ed9f007eSKees Cook	  usable entropy is limited by the kernel being built using
2136ed9f007eSKees Cook	  2GB addressing, and that PHYSICAL_ALIGN must be at a
2137ed9f007eSKees Cook	  minimum of 2MB. As a result, only 10 bits of entropy are
2138ed9f007eSKees Cook	  theoretically possible, but the implementations are further
2139ed9f007eSKees Cook	  limited due to memory layouts.
2140e8581e3dSBaoquan He
21416807c846SIngo Molnar	  If unsure, say Y.
2142da2b6fb9SKees Cook
21438ab3820fSKees Cook# Relocation on x86 needs some additional build support
2144845adf72SH. Peter Anvinconfig X86_NEED_RELOCS
2145845adf72SH. Peter Anvin	def_bool y
21468ab3820fSKees Cook	depends on RANDOMIZE_BASE || (X86_32 && RELOCATABLE)
2147845adf72SH. Peter Anvin
2148506f1d07SSam Ravnborgconfig PHYSICAL_ALIGN
2149a0215061SKees Cook	hex "Alignment value to which kernel should be aligned"
21508ab3820fSKees Cook	default "0x200000"
2151a0215061SKees Cook	range 0x2000 0x1000000 if X86_32
2152a0215061SKees Cook	range 0x200000 0x1000000 if X86_64
21538f9ca475SIngo Molnar	---help---
2154506f1d07SSam Ravnborg	  This value puts the alignment restrictions on physical address
2155506f1d07SSam Ravnborg	  where kernel is loaded and run from. Kernel is compiled for an
2156506f1d07SSam Ravnborg	  address which meets above alignment restriction.
2157506f1d07SSam Ravnborg
2158506f1d07SSam Ravnborg	  If bootloader loads the kernel at a non-aligned address and
2159506f1d07SSam Ravnborg	  CONFIG_RELOCATABLE is set, kernel will move itself to nearest
2160506f1d07SSam Ravnborg	  address aligned to above value and run from there.
2161506f1d07SSam Ravnborg
2162506f1d07SSam Ravnborg	  If bootloader loads the kernel at a non-aligned address and
2163506f1d07SSam Ravnborg	  CONFIG_RELOCATABLE is not set, kernel will ignore the run time
2164506f1d07SSam Ravnborg	  load address and decompress itself to the address it has been
2165506f1d07SSam Ravnborg	  compiled for and run from there. The address for which kernel is
2166506f1d07SSam Ravnborg	  compiled already meets above alignment restrictions. Hence the
2167506f1d07SSam Ravnborg	  end result is that kernel runs from a physical address meeting
2168506f1d07SSam Ravnborg	  above alignment restrictions.
2169506f1d07SSam Ravnborg
2170a0215061SKees Cook	  On 32-bit this value must be a multiple of 0x2000. On 64-bit
2171a0215061SKees Cook	  this value must be a multiple of 0x200000.
2172a0215061SKees Cook
2173506f1d07SSam Ravnborg	  Don't change this unless you know what you are doing.
2174506f1d07SSam Ravnborg
2175eedb92abSKirill A. Shutemovconfig DYNAMIC_MEMORY_LAYOUT
2176eedb92abSKirill A. Shutemov	bool
2177eedb92abSKirill A. Shutemov	---help---
2178eedb92abSKirill A. Shutemov	  This option makes base addresses of vmalloc and vmemmap as well as
2179eedb92abSKirill A. Shutemov	  __PAGE_OFFSET movable during boot.
2180eedb92abSKirill A. Shutemov
21810483e1faSThomas Garnierconfig RANDOMIZE_MEMORY
21820483e1faSThomas Garnier	bool "Randomize the kernel memory sections"
21830483e1faSThomas Garnier	depends on X86_64
21840483e1faSThomas Garnier	depends on RANDOMIZE_BASE
2185eedb92abSKirill A. Shutemov	select DYNAMIC_MEMORY_LAYOUT
21860483e1faSThomas Garnier	default RANDOMIZE_BASE
21870483e1faSThomas Garnier	---help---
21880483e1faSThomas Garnier	   Randomizes the base virtual address of kernel memory sections
21890483e1faSThomas Garnier	   (physical memory mapping, vmalloc & vmemmap). This security feature
21900483e1faSThomas Garnier	   makes exploits relying on predictable memory locations less reliable.
21910483e1faSThomas Garnier
21920483e1faSThomas Garnier	   The order of allocations remains unchanged. Entropy is generated in
21930483e1faSThomas Garnier	   the same way as RANDOMIZE_BASE. Current implementation in the optimal
21940483e1faSThomas Garnier	   configuration have in average 30,000 different possible virtual
21950483e1faSThomas Garnier	   addresses for each memory section.
21960483e1faSThomas Garnier
21976807c846SIngo Molnar	   If unsure, say Y.
21980483e1faSThomas Garnier
219990397a41SThomas Garnierconfig RANDOMIZE_MEMORY_PHYSICAL_PADDING
220090397a41SThomas Garnier	hex "Physical memory mapping padding" if EXPERT
220190397a41SThomas Garnier	depends on RANDOMIZE_MEMORY
220290397a41SThomas Garnier	default "0xa" if MEMORY_HOTPLUG
220390397a41SThomas Garnier	default "0x0"
220490397a41SThomas Garnier	range 0x1 0x40 if MEMORY_HOTPLUG
220590397a41SThomas Garnier	range 0x0 0x40
220690397a41SThomas Garnier	---help---
220790397a41SThomas Garnier	   Define the padding in terabytes added to the existing physical
220890397a41SThomas Garnier	   memory size during kernel memory randomization. It is useful
220990397a41SThomas Garnier	   for memory hotplug support but reduces the entropy available for
221090397a41SThomas Garnier	   address randomization.
221190397a41SThomas Garnier
221290397a41SThomas Garnier	   If unsure, leave at the default value.
221390397a41SThomas Garnier
2214506f1d07SSam Ravnborgconfig HOTPLUG_CPU
2215bebd024eSThomas Gleixner	def_bool y
221640b31360SStephen Rothwell	depends on SMP
2217506f1d07SSam Ravnborg
221880aa1dffSFenghua Yuconfig BOOTPARAM_HOTPLUG_CPU0
221980aa1dffSFenghua Yu	bool "Set default setting of cpu0_hotpluggable"
22202c922cd0SKees Cook	depends on HOTPLUG_CPU
222180aa1dffSFenghua Yu	---help---
222280aa1dffSFenghua Yu	  Set whether default state of cpu0_hotpluggable is on or off.
222380aa1dffSFenghua Yu
222480aa1dffSFenghua Yu	  Say Y here to enable CPU0 hotplug by default. If this switch
222580aa1dffSFenghua Yu	  is turned on, there is no need to give cpu0_hotplug kernel
222680aa1dffSFenghua Yu	  parameter and the CPU0 hotplug feature is enabled by default.
222780aa1dffSFenghua Yu
222880aa1dffSFenghua Yu	  Please note: there are two known CPU0 dependencies if you want
222980aa1dffSFenghua Yu	  to enable the CPU0 hotplug feature either by this switch or by
223080aa1dffSFenghua Yu	  cpu0_hotplug kernel parameter.
223180aa1dffSFenghua Yu
223280aa1dffSFenghua Yu	  First, resume from hibernate or suspend always starts from CPU0.
223380aa1dffSFenghua Yu	  So hibernate and suspend are prevented if CPU0 is offline.
223480aa1dffSFenghua Yu
223580aa1dffSFenghua Yu	  Second dependency is PIC interrupts always go to CPU0. CPU0 can not
223680aa1dffSFenghua Yu	  offline if any interrupt can not migrate out of CPU0. There may
223780aa1dffSFenghua Yu	  be other CPU0 dependencies.
223880aa1dffSFenghua Yu
223980aa1dffSFenghua Yu	  Please make sure the dependencies are under your control before
224080aa1dffSFenghua Yu	  you enable this feature.
224180aa1dffSFenghua Yu
224280aa1dffSFenghua Yu	  Say N if you don't want to enable CPU0 hotplug feature by default.
224380aa1dffSFenghua Yu	  You still can enable the CPU0 hotplug feature at boot by kernel
224480aa1dffSFenghua Yu	  parameter cpu0_hotplug.
224580aa1dffSFenghua Yu
2246a71c8bc5SFenghua Yuconfig DEBUG_HOTPLUG_CPU0
2247a71c8bc5SFenghua Yu	def_bool n
2248a71c8bc5SFenghua Yu	prompt "Debug CPU0 hotplug"
22492c922cd0SKees Cook	depends on HOTPLUG_CPU
2250a71c8bc5SFenghua Yu	---help---
2251a71c8bc5SFenghua Yu	  Enabling this option offlines CPU0 (if CPU0 can be offlined) as
2252a71c8bc5SFenghua Yu	  soon as possible and boots up userspace with CPU0 offlined. User
2253a71c8bc5SFenghua Yu	  can online CPU0 back after boot time.
2254a71c8bc5SFenghua Yu
2255a71c8bc5SFenghua Yu	  To debug CPU0 hotplug, you need to enable CPU0 offline/online
2256a71c8bc5SFenghua Yu	  feature by either turning on CONFIG_BOOTPARAM_HOTPLUG_CPU0 during
2257a71c8bc5SFenghua Yu	  compilation or giving cpu0_hotplug kernel parameter at boot.
2258a71c8bc5SFenghua Yu
2259a71c8bc5SFenghua Yu	  If unsure, say N.
2260a71c8bc5SFenghua Yu
2261506f1d07SSam Ravnborgconfig COMPAT_VDSO
2262b0b49f26SAndy Lutomirski	def_bool n
2263b0b49f26SAndy Lutomirski	prompt "Disable the 32-bit vDSO (needed for glibc 2.3.3)"
2264953fee1dSIngo Molnar	depends on COMPAT_32
22658f9ca475SIngo Molnar	---help---
2266b0b49f26SAndy Lutomirski	  Certain buggy versions of glibc will crash if they are
2267b0b49f26SAndy Lutomirski	  presented with a 32-bit vDSO that is not mapped at the address
2268b0b49f26SAndy Lutomirski	  indicated in its segment table.
2269e84446deSRandy Dunlap
2270b0b49f26SAndy Lutomirski	  The bug was introduced by f866314b89d56845f55e6f365e18b31ec978ec3a
2271b0b49f26SAndy Lutomirski	  and fixed by 3b3ddb4f7db98ec9e912ccdf54d35df4aa30e04a and
2272b0b49f26SAndy Lutomirski	  49ad572a70b8aeb91e57483a11dd1b77e31c4468.  Glibc 2.3.3 is
2273b0b49f26SAndy Lutomirski	  the only released version with the bug, but OpenSUSE 9
2274b0b49f26SAndy Lutomirski	  contains a buggy "glibc 2.3.2".
2275506f1d07SSam Ravnborg
2276b0b49f26SAndy Lutomirski	  The symptom of the bug is that everything crashes on startup, saying:
2277b0b49f26SAndy Lutomirski	  dl_main: Assertion `(void *) ph->p_vaddr == _rtld_local._dl_sysinfo_dso' failed!
2278b0b49f26SAndy Lutomirski
2279b0b49f26SAndy Lutomirski	  Saying Y here changes the default value of the vdso32 boot
2280b0b49f26SAndy Lutomirski	  option from 1 to 0, which turns off the 32-bit vDSO entirely.
2281b0b49f26SAndy Lutomirski	  This works around the glibc bug but hurts performance.
2282b0b49f26SAndy Lutomirski
2283b0b49f26SAndy Lutomirski	  If unsure, say N: if you are compiling your own kernel, you
2284b0b49f26SAndy Lutomirski	  are unlikely to be using a buggy version of glibc.
2285506f1d07SSam Ravnborg
22863dc33bd3SKees Cookchoice
22873dc33bd3SKees Cook	prompt "vsyscall table for legacy applications"
22883dc33bd3SKees Cook	depends on X86_64
22893dc33bd3SKees Cook	default LEGACY_VSYSCALL_EMULATE
22903dc33bd3SKees Cook	help
22913dc33bd3SKees Cook	  Legacy user code that does not know how to find the vDSO expects
22923dc33bd3SKees Cook	  to be able to issue three syscalls by calling fixed addresses in
22933dc33bd3SKees Cook	  kernel space. Since this location is not randomized with ASLR,
22943dc33bd3SKees Cook	  it can be used to assist security vulnerability exploitation.
22953dc33bd3SKees Cook
22963dc33bd3SKees Cook	  This setting can be changed at boot time via the kernel command
2297076ca272SAndy Lutomirski	  line parameter vsyscall=[emulate|none].
22983dc33bd3SKees Cook
22993dc33bd3SKees Cook	  On a system with recent enough glibc (2.14 or newer) and no
23003dc33bd3SKees Cook	  static binaries, you can say None without a performance penalty
23013dc33bd3SKees Cook	  to improve security.
23023dc33bd3SKees Cook
23033dc33bd3SKees Cook	  If unsure, select "Emulate".
23043dc33bd3SKees Cook
23053dc33bd3SKees Cook	config LEGACY_VSYSCALL_EMULATE
23063dc33bd3SKees Cook		bool "Emulate"
23073dc33bd3SKees Cook		help
23083dc33bd3SKees Cook		  The kernel traps and emulates calls into the fixed
23093dc33bd3SKees Cook		  vsyscall address mapping. This makes the mapping
23103dc33bd3SKees Cook		  non-executable, but it still contains known contents,
23113dc33bd3SKees Cook		  which could be used in certain rare security vulnerability
23123dc33bd3SKees Cook		  exploits. This configuration is recommended when userspace
23133dc33bd3SKees Cook		  still uses the vsyscall area.
23143dc33bd3SKees Cook
23153dc33bd3SKees Cook	config LEGACY_VSYSCALL_NONE
23163dc33bd3SKees Cook		bool "None"
23173dc33bd3SKees Cook		help
23183dc33bd3SKees Cook		  There will be no vsyscall mapping at all. This will
23193dc33bd3SKees Cook		  eliminate any risk of ASLR bypass due to the vsyscall
23203dc33bd3SKees Cook		  fixed address mapping. Attempts to use the vsyscalls
23213dc33bd3SKees Cook		  will be reported to dmesg, so that either old or
23223dc33bd3SKees Cook		  malicious userspace programs can be identified.
23233dc33bd3SKees Cook
23243dc33bd3SKees Cookendchoice
23253dc33bd3SKees Cook
2326516cbf37STim Birdconfig CMDLINE_BOOL
2327516cbf37STim Bird	bool "Built-in kernel command line"
23288f9ca475SIngo Molnar	---help---
2329516cbf37STim Bird	  Allow for specifying boot arguments to the kernel at
2330516cbf37STim Bird	  build time.  On some systems (e.g. embedded ones), it is
2331516cbf37STim Bird	  necessary or convenient to provide some or all of the
2332516cbf37STim Bird	  kernel boot arguments with the kernel itself (that is,
2333516cbf37STim Bird	  to not rely on the boot loader to provide them.)
2334516cbf37STim Bird
2335516cbf37STim Bird	  To compile command line arguments into the kernel,
2336516cbf37STim Bird	  set this option to 'Y', then fill in the
233769711ca1SSébastien Hinderer	  boot arguments in CONFIG_CMDLINE.
2338516cbf37STim Bird
2339516cbf37STim Bird	  Systems with fully functional boot loaders (i.e. non-embedded)
2340516cbf37STim Bird	  should leave this option set to 'N'.
2341516cbf37STim Bird
2342516cbf37STim Birdconfig CMDLINE
2343516cbf37STim Bird	string "Built-in kernel command string"
2344516cbf37STim Bird	depends on CMDLINE_BOOL
2345516cbf37STim Bird	default ""
23468f9ca475SIngo Molnar	---help---
2347516cbf37STim Bird	  Enter arguments here that should be compiled into the kernel
2348516cbf37STim Bird	  image and used at boot time.  If the boot loader provides a
2349516cbf37STim Bird	  command line at boot time, it is appended to this string to
2350516cbf37STim Bird	  form the full kernel command line, when the system boots.
2351516cbf37STim Bird
2352516cbf37STim Bird	  However, you can use the CONFIG_CMDLINE_OVERRIDE option to
2353516cbf37STim Bird	  change this behavior.
2354516cbf37STim Bird
2355516cbf37STim Bird	  In most cases, the command line (whether built-in or provided
2356516cbf37STim Bird	  by the boot loader) should specify the device for the root
2357516cbf37STim Bird	  file system.
2358516cbf37STim Bird
2359516cbf37STim Birdconfig CMDLINE_OVERRIDE
2360516cbf37STim Bird	bool "Built-in command line overrides boot loader arguments"
2361516cbf37STim Bird	depends on CMDLINE_BOOL
23628f9ca475SIngo Molnar	---help---
2363516cbf37STim Bird	  Set this option to 'Y' to have the kernel ignore the boot loader
2364516cbf37STim Bird	  command line, and use ONLY the built-in command line.
2365516cbf37STim Bird
2366516cbf37STim Bird	  This is used to work around broken boot loaders.  This should
2367516cbf37STim Bird	  be set to 'N' under normal conditions.
2368516cbf37STim Bird
2369a5b9e5a2SAndy Lutomirskiconfig MODIFY_LDT_SYSCALL
2370a5b9e5a2SAndy Lutomirski	bool "Enable the LDT (local descriptor table)" if EXPERT
2371a5b9e5a2SAndy Lutomirski	default y
2372a5b9e5a2SAndy Lutomirski	---help---
2373a5b9e5a2SAndy Lutomirski	  Linux can allow user programs to install a per-process x86
2374a5b9e5a2SAndy Lutomirski	  Local Descriptor Table (LDT) using the modify_ldt(2) system
2375a5b9e5a2SAndy Lutomirski	  call.  This is required to run 16-bit or segmented code such as
2376a5b9e5a2SAndy Lutomirski	  DOSEMU or some Wine programs.  It is also used by some very old
2377a5b9e5a2SAndy Lutomirski	  threading libraries.
2378a5b9e5a2SAndy Lutomirski
2379a5b9e5a2SAndy Lutomirski	  Enabling this feature adds a small amount of overhead to
2380a5b9e5a2SAndy Lutomirski	  context switches and increases the low-level kernel attack
2381a5b9e5a2SAndy Lutomirski	  surface.  Disabling it removes the modify_ldt(2) system call.
2382a5b9e5a2SAndy Lutomirski
2383a5b9e5a2SAndy Lutomirski	  Saying 'N' here may make sense for embedded or server kernels.
2384a5b9e5a2SAndy Lutomirski
2385b700e7f0SSeth Jenningssource "kernel/livepatch/Kconfig"
2386b700e7f0SSeth Jennings
2387506f1d07SSam Ravnborgendmenu
2388506f1d07SSam Ravnborg
23893072e413SMichal Hockoconfig ARCH_HAS_ADD_PAGES
23903072e413SMichal Hocko	def_bool y
23913072e413SMichal Hocko	depends on X86_64 && ARCH_ENABLE_MEMORY_HOTPLUG
23923072e413SMichal Hocko
2393506f1d07SSam Ravnborgconfig ARCH_ENABLE_MEMORY_HOTPLUG
2394506f1d07SSam Ravnborg	def_bool y
2395506f1d07SSam Ravnborg	depends on X86_64 || (X86_32 && HIGHMEM)
2396506f1d07SSam Ravnborg
239735551053SGary Hadeconfig ARCH_ENABLE_MEMORY_HOTREMOVE
239835551053SGary Hade	def_bool y
239935551053SGary Hade	depends on MEMORY_HOTPLUG
240035551053SGary Hade
2401e534c7c5SLee Schermerhornconfig USE_PERCPU_NUMA_NODE_ID
2402645a7919STejun Heo	def_bool y
2403e534c7c5SLee Schermerhorn	depends on NUMA
2404e534c7c5SLee Schermerhorn
24059491846fSKirill A. Shutemovconfig ARCH_ENABLE_SPLIT_PMD_PTLOCK
24069491846fSKirill A. Shutemov	def_bool y
24079491846fSKirill A. Shutemov	depends on X86_64 || X86_PAE
24089491846fSKirill A. Shutemov
2409c177c81eSNaoya Horiguchiconfig ARCH_ENABLE_HUGEPAGE_MIGRATION
2410c177c81eSNaoya Horiguchi	def_bool y
2411c177c81eSNaoya Horiguchi	depends on X86_64 && HUGETLB_PAGE && MIGRATION
2412c177c81eSNaoya Horiguchi
24139c670ea3SNaoya Horiguchiconfig ARCH_ENABLE_THP_MIGRATION
24149c670ea3SNaoya Horiguchi	def_bool y
24159c670ea3SNaoya Horiguchi	depends on X86_64 && TRANSPARENT_HUGEPAGE
24169c670ea3SNaoya Horiguchi
2417da85f865SBjorn Helgaasmenu "Power management and ACPI options"
2418e279b6c1SSam Ravnborg
2419e279b6c1SSam Ravnborgconfig ARCH_HIBERNATION_HEADER
24203c2362e6SHarvey Harrison	def_bool y
242144556530SZhimin Gu	depends on HIBERNATION
2422e279b6c1SSam Ravnborg
2423e279b6c1SSam Ravnborgsource "kernel/power/Kconfig"
2424e279b6c1SSam Ravnborg
2425e279b6c1SSam Ravnborgsource "drivers/acpi/Kconfig"
2426e279b6c1SSam Ravnborg
2427efafc8b2SFeng Tangsource "drivers/sfi/Kconfig"
2428efafc8b2SFeng Tang
2429a6b68076SAndi Kleenconfig X86_APM_BOOT
24306fc108a0SJan Beulich	def_bool y
2431282e5aabSPaul Bolle	depends on APM
2432a6b68076SAndi Kleen
2433e279b6c1SSam Ravnborgmenuconfig APM
2434e279b6c1SSam Ravnborg	tristate "APM (Advanced Power Management) BIOS support"
2435efefa6f6SIngo Molnar	depends on X86_32 && PM_SLEEP
2436e279b6c1SSam Ravnborg	---help---
2437e279b6c1SSam Ravnborg	  APM is a BIOS specification for saving power using several different
2438e279b6c1SSam Ravnborg	  techniques. This is mostly useful for battery powered laptops with
2439e279b6c1SSam Ravnborg	  APM compliant BIOSes. If you say Y here, the system time will be
2440e279b6c1SSam Ravnborg	  reset after a RESUME operation, the /proc/apm device will provide
2441e279b6c1SSam Ravnborg	  battery status information, and user-space programs will receive
2442e279b6c1SSam Ravnborg	  notification of APM "events" (e.g. battery status change).
2443e279b6c1SSam Ravnborg
2444e279b6c1SSam Ravnborg	  If you select "Y" here, you can disable actual use of the APM
2445e279b6c1SSam Ravnborg	  BIOS by passing the "apm=off" option to the kernel at boot time.
2446e279b6c1SSam Ravnborg
2447e279b6c1SSam Ravnborg	  Note that the APM support is almost completely disabled for
2448e279b6c1SSam Ravnborg	  machines with more than one CPU.
2449e279b6c1SSam Ravnborg
2450e279b6c1SSam Ravnborg	  In order to use APM, you will need supporting software. For location
24512dc98fd3SMichael Witten	  and more information, read <file:Documentation/power/apm-acpi.txt>
24522dc98fd3SMichael Witten	  and the Battery Powered Linux mini-HOWTO, available from
2453e279b6c1SSam Ravnborg	  <http://www.tldp.org/docs.html#howto>.
2454e279b6c1SSam Ravnborg
2455e279b6c1SSam Ravnborg	  This driver does not spin down disk drives (see the hdparm(8)
2456e279b6c1SSam Ravnborg	  manpage ("man 8 hdparm") for that), and it doesn't turn off
2457e279b6c1SSam Ravnborg	  VESA-compliant "green" monitors.
2458e279b6c1SSam Ravnborg
2459e279b6c1SSam Ravnborg	  This driver does not support the TI 4000M TravelMate and the ACER
2460e279b6c1SSam Ravnborg	  486/DX4/75 because they don't have compliant BIOSes. Many "green"
2461e279b6c1SSam Ravnborg	  desktop machines also don't have compliant BIOSes, and this driver
2462e279b6c1SSam Ravnborg	  may cause those machines to panic during the boot phase.
2463e279b6c1SSam Ravnborg
2464e279b6c1SSam Ravnborg	  Generally, if you don't have a battery in your machine, there isn't
2465e279b6c1SSam Ravnborg	  much point in using this driver and you should say N. If you get
2466e279b6c1SSam Ravnborg	  random kernel OOPSes or reboots that don't seem to be related to
2467e279b6c1SSam Ravnborg	  anything, try disabling/enabling this option (or disabling/enabling
2468e279b6c1SSam Ravnborg	  APM in your BIOS).
2469e279b6c1SSam Ravnborg
2470e279b6c1SSam Ravnborg	  Some other things you should try when experiencing seemingly random,
2471e279b6c1SSam Ravnborg	  "weird" problems:
2472e279b6c1SSam Ravnborg
2473e279b6c1SSam Ravnborg	  1) make sure that you have enough swap space and that it is
2474e279b6c1SSam Ravnborg	  enabled.
2475e279b6c1SSam Ravnborg	  2) pass the "no-hlt" option to the kernel
2476e279b6c1SSam Ravnborg	  3) switch on floating point emulation in the kernel and pass
2477e279b6c1SSam Ravnborg	  the "no387" option to the kernel
2478e279b6c1SSam Ravnborg	  4) pass the "floppy=nodma" option to the kernel
2479e279b6c1SSam Ravnborg	  5) pass the "mem=4M" option to the kernel (thereby disabling
2480e279b6c1SSam Ravnborg	  all but the first 4 MB of RAM)
2481e279b6c1SSam Ravnborg	  6) make sure that the CPU is not over clocked.
2482e279b6c1SSam Ravnborg	  7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/>
2483e279b6c1SSam Ravnborg	  8) disable the cache from your BIOS settings
2484e279b6c1SSam Ravnborg	  9) install a fan for the video card or exchange video RAM
2485e279b6c1SSam Ravnborg	  10) install a better fan for the CPU
2486e279b6c1SSam Ravnborg	  11) exchange RAM chips
2487e279b6c1SSam Ravnborg	  12) exchange the motherboard.
2488e279b6c1SSam Ravnborg
2489e279b6c1SSam Ravnborg	  To compile this driver as a module, choose M here: the
2490e279b6c1SSam Ravnborg	  module will be called apm.
2491e279b6c1SSam Ravnborg
2492e279b6c1SSam Ravnborgif APM
2493e279b6c1SSam Ravnborg
2494e279b6c1SSam Ravnborgconfig APM_IGNORE_USER_SUSPEND
2495e279b6c1SSam Ravnborg	bool "Ignore USER SUSPEND"
24968f9ca475SIngo Molnar	---help---
2497e279b6c1SSam Ravnborg	  This option will ignore USER SUSPEND requests. On machines with a
2498e279b6c1SSam Ravnborg	  compliant APM BIOS, you want to say N. However, on the NEC Versa M
2499e279b6c1SSam Ravnborg	  series notebooks, it is necessary to say Y because of a BIOS bug.
2500e279b6c1SSam Ravnborg
2501e279b6c1SSam Ravnborgconfig APM_DO_ENABLE
2502e279b6c1SSam Ravnborg	bool "Enable PM at boot time"
2503e279b6c1SSam Ravnborg	---help---
2504e279b6c1SSam Ravnborg	  Enable APM features at boot time. From page 36 of the APM BIOS
2505e279b6c1SSam Ravnborg	  specification: "When disabled, the APM BIOS does not automatically
2506e279b6c1SSam Ravnborg	  power manage devices, enter the Standby State, enter the Suspend
2507e279b6c1SSam Ravnborg	  State, or take power saving steps in response to CPU Idle calls."
2508e279b6c1SSam Ravnborg	  This driver will make CPU Idle calls when Linux is idle (unless this
2509e279b6c1SSam Ravnborg	  feature is turned off -- see "Do CPU IDLE calls", below). This
2510e279b6c1SSam Ravnborg	  should always save battery power, but more complicated APM features
2511e279b6c1SSam Ravnborg	  will be dependent on your BIOS implementation. You may need to turn
2512e279b6c1SSam Ravnborg	  this option off if your computer hangs at boot time when using APM
2513e279b6c1SSam Ravnborg	  support, or if it beeps continuously instead of suspending. Turn
2514e279b6c1SSam Ravnborg	  this off if you have a NEC UltraLite Versa 33/C or a Toshiba
2515e279b6c1SSam Ravnborg	  T400CDT. This is off by default since most machines do fine without
2516e279b6c1SSam Ravnborg	  this feature.
2517e279b6c1SSam Ravnborg
2518e279b6c1SSam Ravnborgconfig APM_CPU_IDLE
2519dd8af076SLen Brown	depends on CPU_IDLE
2520e279b6c1SSam Ravnborg	bool "Make CPU Idle calls when idle"
25218f9ca475SIngo Molnar	---help---
2522e279b6c1SSam Ravnborg	  Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop.
2523e279b6c1SSam Ravnborg	  On some machines, this can activate improved power savings, such as
2524e279b6c1SSam Ravnborg	  a slowed CPU clock rate, when the machine is idle. These idle calls
2525e279b6c1SSam Ravnborg	  are made after the idle loop has run for some length of time (e.g.,
2526e279b6c1SSam Ravnborg	  333 mS). On some machines, this will cause a hang at boot time or
2527e279b6c1SSam Ravnborg	  whenever the CPU becomes idle. (On machines with more than one CPU,
2528e279b6c1SSam Ravnborg	  this option does nothing.)
2529e279b6c1SSam Ravnborg
2530e279b6c1SSam Ravnborgconfig APM_DISPLAY_BLANK
2531e279b6c1SSam Ravnborg	bool "Enable console blanking using APM"
25328f9ca475SIngo Molnar	---help---
2533e279b6c1SSam Ravnborg	  Enable console blanking using the APM. Some laptops can use this to
2534e279b6c1SSam Ravnborg	  turn off the LCD backlight when the screen blanker of the Linux
2535e279b6c1SSam Ravnborg	  virtual console blanks the screen. Note that this is only used by
2536e279b6c1SSam Ravnborg	  the virtual console screen blanker, and won't turn off the backlight
2537e279b6c1SSam Ravnborg	  when using the X Window system. This also doesn't have anything to
2538e279b6c1SSam Ravnborg	  do with your VESA-compliant power-saving monitor. Further, this
2539e279b6c1SSam Ravnborg	  option doesn't work for all laptops -- it might not turn off your
2540e279b6c1SSam Ravnborg	  backlight at all, or it might print a lot of errors to the console,
2541e279b6c1SSam Ravnborg	  especially if you are using gpm.
2542e279b6c1SSam Ravnborg
2543e279b6c1SSam Ravnborgconfig APM_ALLOW_INTS
2544e279b6c1SSam Ravnborg	bool "Allow interrupts during APM BIOS calls"
25458f9ca475SIngo Molnar	---help---
2546e279b6c1SSam Ravnborg	  Normally we disable external interrupts while we are making calls to
2547e279b6c1SSam Ravnborg	  the APM BIOS as a measure to lessen the effects of a badly behaving
2548e279b6c1SSam Ravnborg	  BIOS implementation.  The BIOS should reenable interrupts if it
2549e279b6c1SSam Ravnborg	  needs to.  Unfortunately, some BIOSes do not -- especially those in
2550e279b6c1SSam Ravnborg	  many of the newer IBM Thinkpads.  If you experience hangs when you
2551e279b6c1SSam Ravnborg	  suspend, try setting this to Y.  Otherwise, say N.
2552e279b6c1SSam Ravnborg
2553e279b6c1SSam Ravnborgendif # APM
2554e279b6c1SSam Ravnborg
2555bb0a56ecSDave Jonessource "drivers/cpufreq/Kconfig"
2556e279b6c1SSam Ravnborg
2557e279b6c1SSam Ravnborgsource "drivers/cpuidle/Kconfig"
2558e279b6c1SSam Ravnborg
255927471fdbSAndy Henroidsource "drivers/idle/Kconfig"
256027471fdbSAndy Henroid
2561e279b6c1SSam Ravnborgendmenu
2562e279b6c1SSam Ravnborg
2563e279b6c1SSam Ravnborg
2564e279b6c1SSam Ravnborgmenu "Bus options (PCI etc.)"
2565e279b6c1SSam Ravnborg
2566e279b6c1SSam Ravnborgchoice
2567e279b6c1SSam Ravnborg	prompt "PCI access mode"
2568efefa6f6SIngo Molnar	depends on X86_32 && PCI
2569e279b6c1SSam Ravnborg	default PCI_GOANY
2570e279b6c1SSam Ravnborg	---help---
2571e279b6c1SSam Ravnborg	  On PCI systems, the BIOS can be used to detect the PCI devices and
2572e279b6c1SSam Ravnborg	  determine their configuration. However, some old PCI motherboards
2573e279b6c1SSam Ravnborg	  have BIOS bugs and may crash if this is done. Also, some embedded
2574e279b6c1SSam Ravnborg	  PCI-based systems don't have any BIOS at all. Linux can also try to
2575e279b6c1SSam Ravnborg	  detect the PCI hardware directly without using the BIOS.
2576e279b6c1SSam Ravnborg
2577e279b6c1SSam Ravnborg	  With this option, you can specify how Linux should detect the
2578e279b6c1SSam Ravnborg	  PCI devices. If you choose "BIOS", the BIOS will be used,
2579e279b6c1SSam Ravnborg	  if you choose "Direct", the BIOS won't be used, and if you
2580e279b6c1SSam Ravnborg	  choose "MMConfig", then PCI Express MMCONFIG will be used.
2581e279b6c1SSam Ravnborg	  If you choose "Any", the kernel will try MMCONFIG, then the
2582e279b6c1SSam Ravnborg	  direct access method and falls back to the BIOS if that doesn't
2583e279b6c1SSam Ravnborg	  work. If unsure, go with the default, which is "Any".
2584e279b6c1SSam Ravnborg
2585e279b6c1SSam Ravnborgconfig PCI_GOBIOS
2586e279b6c1SSam Ravnborg	bool "BIOS"
2587e279b6c1SSam Ravnborg
2588e279b6c1SSam Ravnborgconfig PCI_GOMMCONFIG
2589e279b6c1SSam Ravnborg	bool "MMConfig"
2590e279b6c1SSam Ravnborg
2591e279b6c1SSam Ravnborgconfig PCI_GODIRECT
2592e279b6c1SSam Ravnborg	bool "Direct"
2593e279b6c1SSam Ravnborg
25943ef0e1f8SAndres Salomonconfig PCI_GOOLPC
259576fb6570SDaniel Drake	bool "OLPC XO-1"
25963ef0e1f8SAndres Salomon	depends on OLPC
25973ef0e1f8SAndres Salomon
25982bdd1b03SAndres Salomonconfig PCI_GOANY
25992bdd1b03SAndres Salomon	bool "Any"
26002bdd1b03SAndres Salomon
2601e279b6c1SSam Ravnborgendchoice
2602e279b6c1SSam Ravnborg
2603e279b6c1SSam Ravnborgconfig PCI_BIOS
26043c2362e6SHarvey Harrison	def_bool y
2605efefa6f6SIngo Molnar	depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY)
2606e279b6c1SSam Ravnborg
2607e279b6c1SSam Ravnborg# x86-64 doesn't support PCI BIOS access from long mode so always go direct.
2608e279b6c1SSam Ravnborgconfig PCI_DIRECT
26093c2362e6SHarvey Harrison	def_bool y
26100aba496fSShaohua Li	depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC || PCI_GOMMCONFIG))
2611e279b6c1SSam Ravnborg
2612e279b6c1SSam Ravnborgconfig PCI_MMCONFIG
2613b45c9f36SJan Kiszka	bool "Support mmconfig PCI config space access" if X86_64
2614b45c9f36SJan Kiszka	default y
26158364e1f8SJan Kiszka	depends on PCI && (ACPI || SFI || JAILHOUSE_GUEST)
2616b45c9f36SJan Kiszka	depends on X86_64 || (PCI_GOANY || PCI_GOMMCONFIG)
2617e279b6c1SSam Ravnborg
26183ef0e1f8SAndres Salomonconfig PCI_OLPC
26192bdd1b03SAndres Salomon	def_bool y
26202bdd1b03SAndres Salomon	depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY)
26213ef0e1f8SAndres Salomon
2622b5401a96SAlex Nixonconfig PCI_XEN
2623b5401a96SAlex Nixon	def_bool y
2624b5401a96SAlex Nixon	depends on PCI && XEN
2625b5401a96SAlex Nixon	select SWIOTLB_XEN
2626b5401a96SAlex Nixon
26278364e1f8SJan Kiszkaconfig MMCONF_FAM10H
26288364e1f8SJan Kiszka	def_bool y
26298364e1f8SJan Kiszka	depends on X86_64 && PCI_MMCONFIG && ACPI
2630e279b6c1SSam Ravnborg
26313f6ea84aSIra W. Snyderconfig PCI_CNB20LE_QUIRK
26326a108a14SDavid Rientjes	bool "Read CNB20LE Host Bridge Windows" if EXPERT
26336ea30386SKees Cook	depends on PCI
26343f6ea84aSIra W. Snyder	help
26353f6ea84aSIra W. Snyder	  Read the PCI windows out of the CNB20LE host bridge. This allows
26363f6ea84aSIra W. Snyder	  PCI hotplug to work on systems with the CNB20LE chipset which do
26373f6ea84aSIra W. Snyder	  not have ACPI.
26383f6ea84aSIra W. Snyder
263964a5fed6SBjorn Helgaas	  There's no public spec for this chipset, and this functionality
264064a5fed6SBjorn Helgaas	  is known to be incomplete.
264164a5fed6SBjorn Helgaas
264264a5fed6SBjorn Helgaas	  You should say N unless you know you need this.
264364a5fed6SBjorn Helgaas
26443a495511SWilliam Breathitt Grayconfig ISA_BUS
264517a2a129SWilliam Breathitt Gray	bool "ISA bus support on modern systems" if EXPERT
26463a495511SWilliam Breathitt Gray	help
264717a2a129SWilliam Breathitt Gray	  Expose ISA bus device drivers and options available for selection and
264817a2a129SWilliam Breathitt Gray	  configuration. Enable this option if your target machine has an ISA
264917a2a129SWilliam Breathitt Gray	  bus. ISA is an older system, displaced by PCI and newer bus
265017a2a129SWilliam Breathitt Gray	  architectures -- if your target machine is modern, it probably does
265117a2a129SWilliam Breathitt Gray	  not have an ISA bus.
26523a495511SWilliam Breathitt Gray
26533a495511SWilliam Breathitt Gray	  If unsure, say N.
26543a495511SWilliam Breathitt Gray
26551c00f016SDavid Rientjes# x86_64 have no ISA slots, but can have ISA-style DMA.
2656e279b6c1SSam Ravnborgconfig ISA_DMA_API
26571c00f016SDavid Rientjes	bool "ISA-style DMA support" if (X86_64 && EXPERT)
26581c00f016SDavid Rientjes	default y
26591c00f016SDavid Rientjes	help
26601c00f016SDavid Rientjes	  Enables ISA-style DMA support for devices requiring such controllers.
26611c00f016SDavid Rientjes	  If unsure, say Y.
2662e279b6c1SSam Ravnborg
266351e68d05SLinus Torvaldsif X86_32
266451e68d05SLinus Torvalds
2665e279b6c1SSam Ravnborgconfig ISA
2666e279b6c1SSam Ravnborg	bool "ISA support"
26678f9ca475SIngo Molnar	---help---
2668e279b6c1SSam Ravnborg	  Find out whether you have ISA slots on your motherboard.  ISA is the
2669e279b6c1SSam Ravnborg	  name of a bus system, i.e. the way the CPU talks to the other stuff
2670e279b6c1SSam Ravnborg	  inside your box.  Other bus systems are PCI, EISA, MicroChannel
2671e279b6c1SSam Ravnborg	  (MCA) or VESA.  ISA is an older system, now being displaced by PCI;
2672e279b6c1SSam Ravnborg	  newer boards don't support it.  If you have ISA, say Y, otherwise N.
2673e279b6c1SSam Ravnborg
2674e279b6c1SSam Ravnborgconfig SCx200
2675e279b6c1SSam Ravnborg	tristate "NatSemi SCx200 support"
26768f9ca475SIngo Molnar	---help---
2677e279b6c1SSam Ravnborg	  This provides basic support for National Semiconductor's
2678e279b6c1SSam Ravnborg	  (now AMD's) Geode processors.  The driver probes for the
2679e279b6c1SSam Ravnborg	  PCI-IDs of several on-chip devices, so its a good dependency
2680e279b6c1SSam Ravnborg	  for other scx200_* drivers.
2681e279b6c1SSam Ravnborg
2682e279b6c1SSam Ravnborg	  If compiled as a module, the driver is named scx200.
2683e279b6c1SSam Ravnborg
2684e279b6c1SSam Ravnborgconfig SCx200HR_TIMER
2685e279b6c1SSam Ravnborg	tristate "NatSemi SCx200 27MHz High-Resolution Timer Support"
2686592913ecSJohn Stultz	depends on SCx200
2687e279b6c1SSam Ravnborg	default y
26888f9ca475SIngo Molnar	---help---
2689e279b6c1SSam Ravnborg	  This driver provides a clocksource built upon the on-chip
2690e279b6c1SSam Ravnborg	  27MHz high-resolution timer.  Its also a workaround for
2691e279b6c1SSam Ravnborg	  NSC Geode SC-1100's buggy TSC, which loses time when the
2692e279b6c1SSam Ravnborg	  processor goes idle (as is done by the scheduler).  The
2693e279b6c1SSam Ravnborg	  other workaround is idle=poll boot option.
2694e279b6c1SSam Ravnborg
26953ef0e1f8SAndres Salomonconfig OLPC
26963ef0e1f8SAndres Salomon	bool "One Laptop Per Child support"
269754008979SThomas Gleixner	depends on !X86_PAE
26983c554946SAndres Salomon	select GPIOLIB
2699dc3119e7SThomas Gleixner	select OF
270045bb1674SDaniel Drake	select OF_PROMTREE
2701b4e51854SGrant Likely	select IRQ_DOMAIN
27028f9ca475SIngo Molnar	---help---
27033ef0e1f8SAndres Salomon	  Add support for detecting the unique features of the OLPC
27043ef0e1f8SAndres Salomon	  XO hardware.
27053ef0e1f8SAndres Salomon
2706a3128588SDaniel Drakeconfig OLPC_XO1_PM
2707a3128588SDaniel Drake	bool "OLPC XO-1 Power Management"
2708fa112cf1SBorislav Petkov	depends on OLPC && MFD_CS5535=y && PM_SLEEP
2709bf1ebf00SDaniel Drake	---help---
271097c4cb71SDaniel Drake	  Add support for poweroff and suspend of the OLPC XO-1 laptop.
2711bf1ebf00SDaniel Drake
2712cfee9597SDaniel Drakeconfig OLPC_XO1_RTC
2713cfee9597SDaniel Drake	bool "OLPC XO-1 Real Time Clock"
2714cfee9597SDaniel Drake	depends on OLPC_XO1_PM && RTC_DRV_CMOS
2715cfee9597SDaniel Drake	---help---
2716cfee9597SDaniel Drake	  Add support for the XO-1 real time clock, which can be used as a
2717cfee9597SDaniel Drake	  programmable wakeup source.
2718cfee9597SDaniel Drake
27197feda8e9SDaniel Drakeconfig OLPC_XO1_SCI
27207feda8e9SDaniel Drake	bool "OLPC XO-1 SCI extras"
272192e830f2SArnd Bergmann	depends on OLPC && OLPC_XO1_PM && GPIO_CS5535=y
2722ed8e47feSRandy Dunlap	depends on INPUT=y
2723d8d01a63SDaniel Drake	select POWER_SUPPLY
27247feda8e9SDaniel Drake	---help---
27257feda8e9SDaniel Drake	  Add support for SCI-based features of the OLPC XO-1 laptop:
27267bc74b3dSDaniel Drake	   - EC-driven system wakeups
27277feda8e9SDaniel Drake	   - Power button
27287bc74b3dSDaniel Drake	   - Ebook switch
27292cf2baeaSDaniel Drake	   - Lid switch
2730e1040ac6SDaniel Drake	   - AC adapter status updates
2731e1040ac6SDaniel Drake	   - Battery status updates
27327feda8e9SDaniel Drake
2733a0f30f59SDaniel Drakeconfig OLPC_XO15_SCI
2734a0f30f59SDaniel Drake	bool "OLPC XO-1.5 SCI extras"
2735d8d01a63SDaniel Drake	depends on OLPC && ACPI
2736d8d01a63SDaniel Drake	select POWER_SUPPLY
2737a0f30f59SDaniel Drake	---help---
2738a0f30f59SDaniel Drake	  Add support for SCI-based features of the OLPC XO-1.5 laptop:
2739a0f30f59SDaniel Drake	   - EC-driven system wakeups
2740a0f30f59SDaniel Drake	   - AC adapter status updates
2741a0f30f59SDaniel Drake	   - Battery status updates
2742e279b6c1SSam Ravnborg
2743d4f3e350SEd Wildgooseconfig ALIX
2744d4f3e350SEd Wildgoose	bool "PCEngines ALIX System Support (LED setup)"
2745d4f3e350SEd Wildgoose	select GPIOLIB
2746d4f3e350SEd Wildgoose	---help---
2747d4f3e350SEd Wildgoose	  This option enables system support for the PCEngines ALIX.
2748d4f3e350SEd Wildgoose	  At present this just sets up LEDs for GPIO control on
2749d4f3e350SEd Wildgoose	  ALIX2/3/6 boards.  However, other system specific setup should
2750d4f3e350SEd Wildgoose	  get added here.
2751d4f3e350SEd Wildgoose
2752d4f3e350SEd Wildgoose	  Note: You must still enable the drivers for GPIO and LED support
2753d4f3e350SEd Wildgoose	  (GPIO_CS5535 & LEDS_GPIO) to actually use the LEDs
2754d4f3e350SEd Wildgoose
2755d4f3e350SEd Wildgoose	  Note: You have to set alix.force=1 for boards with Award BIOS.
2756d4f3e350SEd Wildgoose
2757da4e3302SPhilip Prindevilleconfig NET5501
2758da4e3302SPhilip Prindeville	bool "Soekris Engineering net5501 System Support (LEDS, GPIO, etc)"
2759da4e3302SPhilip Prindeville	select GPIOLIB
2760da4e3302SPhilip Prindeville	---help---
2761da4e3302SPhilip Prindeville	  This option enables system support for the Soekris Engineering net5501.
2762da4e3302SPhilip Prindeville
27633197059aSPhilip A. Prindevilleconfig GEOS
27643197059aSPhilip A. Prindeville	bool "Traverse Technologies GEOS System Support (LEDS, GPIO, etc)"
27653197059aSPhilip A. Prindeville	select GPIOLIB
27663197059aSPhilip A. Prindeville	depends on DMI
27673197059aSPhilip A. Prindeville	---help---
27683197059aSPhilip A. Prindeville	  This option enables system support for the Traverse Technologies GEOS.
27693197059aSPhilip A. Prindeville
27707d029125SVivien Didelotconfig TS5500
27717d029125SVivien Didelot	bool "Technologic Systems TS-5500 platform support"
27727d029125SVivien Didelot	depends on MELAN
27737d029125SVivien Didelot	select CHECK_SIGNATURE
27747d029125SVivien Didelot	select NEW_LEDS
27757d029125SVivien Didelot	select LEDS_CLASS
27767d029125SVivien Didelot	---help---
27777d029125SVivien Didelot	  This option enables system support for the Technologic Systems TS-5500.
27787d029125SVivien Didelot
2779e279b6c1SSam Ravnborgendif # X86_32
2780e279b6c1SSam Ravnborg
278123ac4ae8SAndreas Herrmannconfig AMD_NB
2782e279b6c1SSam Ravnborg	def_bool y
27830e152cd7SBorislav Petkov	depends on CPU_SUP_AMD && PCI
2784e279b6c1SSam Ravnborg
2785e3263ab3SDavid Herrmannconfig X86_SYSFB
2786e3263ab3SDavid Herrmann	bool "Mark VGA/VBE/EFI FB as generic system framebuffer"
2787e3263ab3SDavid Herrmann	help
2788e3263ab3SDavid Herrmann	  Firmwares often provide initial graphics framebuffers so the BIOS,
2789e3263ab3SDavid Herrmann	  bootloader or kernel can show basic video-output during boot for
2790e3263ab3SDavid Herrmann	  user-guidance and debugging. Historically, x86 used the VESA BIOS
2791e3263ab3SDavid Herrmann	  Extensions and EFI-framebuffers for this, which are mostly limited
2792e3263ab3SDavid Herrmann	  to x86.
2793e3263ab3SDavid Herrmann	  This option, if enabled, marks VGA/VBE/EFI framebuffers as generic
2794e3263ab3SDavid Herrmann	  framebuffers so the new generic system-framebuffer drivers can be
2795e3263ab3SDavid Herrmann	  used on x86. If the framebuffer is not compatible with the generic
2796e3a5dc08SNikolas Nyby	  modes, it is advertised as fallback platform framebuffer so legacy
2797e3263ab3SDavid Herrmann	  drivers like efifb, vesafb and uvesafb can pick it up.
2798e3263ab3SDavid Herrmann	  If this option is not selected, all system framebuffers are always
2799e3263ab3SDavid Herrmann	  marked as fallback platform framebuffers as usual.
2800e3263ab3SDavid Herrmann
2801e3263ab3SDavid Herrmann	  Note: Legacy fbdev drivers, including vesafb, efifb, uvesafb, will
2802e3263ab3SDavid Herrmann	  not be able to pick up generic system framebuffers if this option
2803e3263ab3SDavid Herrmann	  is selected. You are highly encouraged to enable simplefb as
2804e3263ab3SDavid Herrmann	  replacement if you select this option. simplefb can correctly deal
2805e3263ab3SDavid Herrmann	  with generic system framebuffers. But you should still keep vesafb
2806e3263ab3SDavid Herrmann	  and others enabled as fallback if a system framebuffer is
2807e3263ab3SDavid Herrmann	  incompatible with simplefb.
2808e3263ab3SDavid Herrmann
2809e3263ab3SDavid Herrmann	  If unsure, say Y.
2810e3263ab3SDavid Herrmann
2811e279b6c1SSam Ravnborgendmenu
2812e279b6c1SSam Ravnborg
2813e279b6c1SSam Ravnborg
28141572497cSChristoph Hellwigmenu "Binary Emulations"
2815e279b6c1SSam Ravnborg
2816e279b6c1SSam Ravnborgconfig IA32_EMULATION
2817e279b6c1SSam Ravnborg	bool "IA32 Emulation"
2818e279b6c1SSam Ravnborg	depends on X86_64
281939f88911SIngo Molnar	select ARCH_WANT_OLD_COMPAT_IPC
2820d1603990SRandy Dunlap	select BINFMT_ELF
2821a97f52e6SRoland McGrath	select COMPAT_BINFMT_ELF
282239f88911SIngo Molnar	select COMPAT_OLD_SIGACTION
28238f9ca475SIngo Molnar	---help---
28245fd92e65SH. J. Lu	  Include code to run legacy 32-bit programs under a
28255fd92e65SH. J. Lu	  64-bit kernel. You should likely turn this on, unless you're
28265fd92e65SH. J. Lu	  100% sure that you don't have any 32-bit programs left.
2827e279b6c1SSam Ravnborg
2828e279b6c1SSam Ravnborgconfig IA32_AOUT
2829e279b6c1SSam Ravnborg	tristate "IA32 a.out support"
28306b213e1bSDavid Woodhouse	depends on IA32_EMULATION
2831eac61655SBorislav Petkov	depends on BROKEN
28328f9ca475SIngo Molnar	---help---
2833e279b6c1SSam Ravnborg	  Support old a.out binaries in the 32bit emulation.
2834e279b6c1SSam Ravnborg
28350bf62763SH. Peter Anvinconfig X86_X32
28366ea30386SKees Cook	bool "x32 ABI for 64-bit mode"
28379b54050bSBrian Gerst	depends on X86_64
28385fd92e65SH. J. Lu	---help---
28395fd92e65SH. J. Lu	  Include code to run binaries for the x32 native 32-bit ABI
28405fd92e65SH. J. Lu	  for 64-bit processors.  An x32 process gets access to the
28415fd92e65SH. J. Lu	  full 64-bit register file and wide data path while leaving
28425fd92e65SH. J. Lu	  pointers at 32 bits for smaller memory footprint.
28435fd92e65SH. J. Lu
28445fd92e65SH. J. Lu	  You will need a recent binutils (2.22 or later) with
28455fd92e65SH. J. Lu	  elf32_x86_64 support enabled to compile a kernel with this
28465fd92e65SH. J. Lu	  option set.
28475fd92e65SH. J. Lu
2848953fee1dSIngo Molnarconfig COMPAT_32
2849953fee1dSIngo Molnar	def_bool y
2850953fee1dSIngo Molnar	depends on IA32_EMULATION || X86_32
2851953fee1dSIngo Molnar	select HAVE_UID16
2852953fee1dSIngo Molnar	select OLD_SIGSUSPEND3
2853953fee1dSIngo Molnar
2854e279b6c1SSam Ravnborgconfig COMPAT
28553c2362e6SHarvey Harrison	def_bool y
28560bf62763SH. Peter Anvin	depends on IA32_EMULATION || X86_X32
2857e279b6c1SSam Ravnborg
28583120e25eSJan Beulichif COMPAT
2859e279b6c1SSam Ravnborgconfig COMPAT_FOR_U64_ALIGNMENT
28603120e25eSJan Beulich	def_bool y
2861e279b6c1SSam Ravnborg
2862e279b6c1SSam Ravnborgconfig SYSVIPC_COMPAT
28633c2362e6SHarvey Harrison	def_bool y
28643120e25eSJan Beulich	depends on SYSVIPC
28653120e25eSJan Beulichendif
2866ee009e4aSDavid Howells
2867e279b6c1SSam Ravnborgendmenu
2868e279b6c1SSam Ravnborg
2869e279b6c1SSam Ravnborg
2870e5beae16SKeith Packardconfig HAVE_ATOMIC_IOMAP
2871e5beae16SKeith Packard	def_bool y
2872e5beae16SKeith Packard	depends on X86_32
2873e5beae16SKeith Packard
28744692d77fSAlessandro Rubiniconfig X86_DEV_DMA_OPS
28754692d77fSAlessandro Rubini	bool
287683125a3aSAlessandro Rubini	depends on X86_64 || STA2X11
28774692d77fSAlessandro Rubini
2878f7219a53SAlessandro Rubiniconfig X86_DMA_REMAP
2879f7219a53SAlessandro Rubini	bool
288083125a3aSAlessandro Rubini	depends on STA2X11
2881f7219a53SAlessandro Rubini
2882e585513bSKirill A. Shutemovconfig HAVE_GENERIC_GUP
2883e585513bSKirill A. Shutemov	def_bool y
2884e585513bSKirill A. Shutemov
2885e279b6c1SSam Ravnborgsource "drivers/firmware/Kconfig"
2886e279b6c1SSam Ravnborg
2887edf88417SAvi Kivitysource "arch/x86/kvm/Kconfig"
2888