xref: /linux/arch/x86/Kconfig (revision 05736e4ac13c08a4a9b1ef2de26dd31a32cbee57)
1b2441318SGreg Kroah-Hartman# SPDX-License-Identifier: GPL-2.0
2daa93fabSSam Ravnborg# Select 32 or 64 bit
3daa93fabSSam Ravnborgconfig 64BIT
4104daea1SMasahiro Yamada	bool "64-bit kernel" if "$(ARCH)" = "x86"
5104daea1SMasahiro Yamada	default "$(ARCH)" != "i386"
68f9ca475SIngo Molnar	---help---
7daa93fabSSam Ravnborg	  Say yes to build a 64-bit kernel - formerly known as x86_64
8daa93fabSSam Ravnborg	  Say no to build a 32-bit kernel - formerly known as i386
9daa93fabSSam Ravnborg
10daa93fabSSam Ravnborgconfig X86_32
113120e25eSJan Beulich	def_bool y
123120e25eSJan Beulich	depends on !64BIT
13341c787eSIngo Molnar	# Options that are inherently 32-bit kernel only:
14341c787eSIngo Molnar	select ARCH_WANT_IPC_PARSE_VERSION
15341c787eSIngo Molnar	select CLKSRC_I8253
16341c787eSIngo Molnar	select CLONE_BACKWARDS
17341c787eSIngo Molnar	select HAVE_AOUT
18341c787eSIngo Molnar	select HAVE_GENERIC_DMA_COHERENT
19341c787eSIngo Molnar	select MODULES_USE_ELF_REL
20341c787eSIngo Molnar	select OLD_SIGACTION
21daa93fabSSam Ravnborg
22daa93fabSSam Ravnborgconfig X86_64
233120e25eSJan Beulich	def_bool y
243120e25eSJan Beulich	depends on 64BIT
25d94e0685SIngo Molnar	# Options that are inherently 64-bit kernel only:
26e1073d1eSAneesh Kumar K.V	select ARCH_HAS_GIGANTIC_PAGE if (MEMORY_ISOLATION && COMPACTION) || CMA
27d94e0685SIngo Molnar	select ARCH_SUPPORTS_INT128
28d94e0685SIngo Molnar	select ARCH_USE_CMPXCHG_LOCKREF
29d94e0685SIngo Molnar	select HAVE_ARCH_SOFT_DIRTY
30d94e0685SIngo Molnar	select MODULES_USE_ELF_RELA
31f616ab59SChristoph Hellwig	select NEED_DMA_MAP_STATE
3209230cbcSChristoph Hellwig	select SWIOTLB
33d94e0685SIngo Molnar	select X86_DEV_DMA_OPS
34f8781c4aSDominik Brodowski	select ARCH_HAS_SYSCALL_WRAPPER
351032c0baSSam Ravnborg
36d94e0685SIngo Molnar#
37d94e0685SIngo Molnar# Arch settings
38d94e0685SIngo Molnar#
39d94e0685SIngo Molnar# ( Note that options that are marked 'if X86_64' could in principle be
40d94e0685SIngo Molnar#   ported to 32-bit as well. )
41d94e0685SIngo Molnar#
428d5fffb9SSam Ravnborgconfig X86
433c2362e6SHarvey Harrison	def_bool y
44c763ea26SIngo Molnar	#
45c763ea26SIngo Molnar	# Note: keep this list sorted alphabetically
46c763ea26SIngo Molnar	#
476471b825SIngo Molnar	select ACPI_LEGACY_TABLES_LOOKUP	if ACPI
486e0a0ea1SGraeme Gregory	select ACPI_SYSTEM_POWER_STATES_SUPPORT	if ACPI
496471b825SIngo Molnar	select ANON_INODES
506471b825SIngo Molnar	select ARCH_CLOCKSOURCE_DATA
516471b825SIngo Molnar	select ARCH_DISCARD_MEMBLOCK
5291dda51aSAleksey Makarov	select ARCH_HAS_ACPI_TABLE_UPGRADE	if ACPI
53fa5b6ec9SLaura Abbott	select ARCH_HAS_DEBUG_VIRTUAL
5421266be9SDan Williams	select ARCH_HAS_DEVMEM_IS_ALLOWED
556471b825SIngo Molnar	select ARCH_HAS_ELF_RANDOMIZE
5672d93104SLinus Torvalds	select ARCH_HAS_FAST_MULTIPLIER
57316d097cSDave Hansen	select ARCH_HAS_FILTER_PGPROT
586974f0c4SDaniel Micay	select ARCH_HAS_FORTIFY_SOURCE
59957e3facSRiku Voipio	select ARCH_HAS_GCOV_PROFILE_ALL
605c9a8750SDmitry Vyukov	select ARCH_HAS_KCOV			if X86_64
6110bcc80eSMathieu Desnoyers	select ARCH_HAS_MEMBARRIER_SYNC_CORE
62c763ea26SIngo Molnar	select ARCH_HAS_PMEM_API		if X86_64
633010a5eaSLaurent Dufour	select ARCH_HAS_PTE_SPECIAL
6439208aa7SKees Cook	select ARCH_HAS_REFCOUNT
650aed55afSDan Williams	select ARCH_HAS_UACCESS_FLUSHCACHE	if X86_64
668780356eSDan Williams	select ARCH_HAS_UACCESS_MCSAFE		if X86_64
67d2852a22SDaniel Borkmann	select ARCH_HAS_SET_MEMORY
686471b825SIngo Molnar	select ARCH_HAS_SG_CHAIN
69ad21fc4fSLaura Abbott	select ARCH_HAS_STRICT_KERNEL_RWX
70ad21fc4fSLaura Abbott	select ARCH_HAS_STRICT_MODULE_RWX
71ac1ab12aSMathieu Desnoyers	select ARCH_HAS_SYNC_CORE_BEFORE_USERMODE
72c6d30853SAndrey Ryabinin	select ARCH_HAS_UBSAN_SANITIZE_ALL
7365f7d049SOliver O'Halloran	select ARCH_HAS_ZONE_DEVICE		if X86_64
746471b825SIngo Molnar	select ARCH_HAVE_NMI_SAFE_CMPXCHG
756471b825SIngo Molnar	select ARCH_MIGHT_HAVE_ACPI_PDC		if ACPI
7677fbbc81SMark Salter	select ARCH_MIGHT_HAVE_PC_PARPORT
775e2c18c0SMark Salter	select ARCH_MIGHT_HAVE_PC_SERIO
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
91fec777c3SChristoph Hellwig	select DMA_DIRECT_OPS
9245471cd9SLinus Torvalds	select EDAC_ATOMIC_SCRUB
9345471cd9SLinus Torvalds	select EDAC_SUPPORT
946471b825SIngo Molnar	select GENERIC_CLOCKEVENTS
956471b825SIngo Molnar	select GENERIC_CLOCKEVENTS_BROADCAST	if X86_64 || (X86_32 && X86_LOCAL_APIC)
966471b825SIngo Molnar	select GENERIC_CLOCKEVENTS_MIN_ADJUST
976471b825SIngo Molnar	select GENERIC_CMOS_UPDATE
986471b825SIngo Molnar	select GENERIC_CPU_AUTOPROBE
9961dc0f55SThomas Gleixner	select GENERIC_CPU_VULNERABILITIES
1006471b825SIngo Molnar	select GENERIC_EARLY_IOREMAP
1016471b825SIngo Molnar	select GENERIC_FIND_FIRST_BIT
1026471b825SIngo Molnar	select GENERIC_IOMAP
103c7d6c9ddSThomas Gleixner	select GENERIC_IRQ_EFFECTIVE_AFF_MASK	if SMP
1040fa115daSThomas Gleixner	select GENERIC_IRQ_MATRIX_ALLOCATOR	if X86_LOCAL_APIC
105ad7a929fSThomas Gleixner	select GENERIC_IRQ_MIGRATION		if SMP
1066471b825SIngo Molnar	select GENERIC_IRQ_PROBE
107c201c917SThomas Gleixner	select GENERIC_IRQ_RESERVATION_MODE
1086471b825SIngo Molnar	select GENERIC_IRQ_SHOW
1096471b825SIngo Molnar	select GENERIC_PENDING_IRQ		if SMP
1106471b825SIngo Molnar	select GENERIC_SMP_IDLE_THREAD
1116471b825SIngo Molnar	select GENERIC_STRNCPY_FROM_USER
1126471b825SIngo Molnar	select GENERIC_STRNLEN_USER
1136471b825SIngo Molnar	select GENERIC_TIME_VSYSCALL
1147edaeb68SThomas Gleixner	select HARDLOCKUP_CHECK_TIMESTAMP	if X86_64
1156471b825SIngo Molnar	select HAVE_ACPI_APEI			if ACPI
1166471b825SIngo Molnar	select HAVE_ACPI_APEI_NMI		if ACPI
1176471b825SIngo Molnar	select HAVE_ALIGNED_STRUCT_PAGE		if SLUB
1186471b825SIngo Molnar	select HAVE_ARCH_AUDITSYSCALL
1196471b825SIngo Molnar	select HAVE_ARCH_HUGE_VMAP		if X86_64 || X86_PAE
1206471b825SIngo Molnar	select HAVE_ARCH_JUMP_LABEL
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
1266471b825SIngo Molnar	select HAVE_ARCH_SECCOMP_FILTER
127f7d83c1cSKees Cook	select HAVE_ARCH_THREAD_STRUCT_WHITELIST
1286471b825SIngo Molnar	select HAVE_ARCH_TRACEHOOK
1296471b825SIngo Molnar	select HAVE_ARCH_TRANSPARENT_HUGEPAGE
130a00cc7d9SMatthew Wilcox	select HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD if X86_64
131e37e43a4SAndy Lutomirski	select HAVE_ARCH_VMAP_STACK		if X86_64
132c763ea26SIngo Molnar	select HAVE_ARCH_WITHIN_STACK_FRAMES
1336471b825SIngo Molnar	select HAVE_CMPXCHG_DOUBLE
1346471b825SIngo Molnar	select HAVE_CMPXCHG_LOCAL
1356471b825SIngo Molnar	select HAVE_CONTEXT_TRACKING		if X86_64
136c1bd55f9SJosh Triplett	select HAVE_COPY_THREAD_TLS
1376471b825SIngo Molnar	select HAVE_C_RECORDMCOUNT
1386471b825SIngo Molnar	select HAVE_DEBUG_KMEMLEAK
1396471b825SIngo Molnar	select HAVE_DEBUG_STACKOVERFLOW
1409c5a3621SAkinobu Mita	select HAVE_DMA_CONTIGUOUS
141677aa9f7SSteven Rostedt	select HAVE_DYNAMIC_FTRACE
14206aeaaeaSMasami Hiramatsu	select HAVE_DYNAMIC_FTRACE_WITH_REGS
14303f5781bSWang YanQing	select HAVE_EBPF_JIT
14458340a07SJohannes Berg	select HAVE_EFFICIENT_UNALIGNED_ACCESS
1455f56a5dfSJiri Slaby	select HAVE_EXIT_THREAD
146644e0e8dSSteven Rostedt (VMware)	select HAVE_FENTRY			if X86_64 || DYNAMIC_FTRACE
1476471b825SIngo Molnar	select HAVE_FTRACE_MCOUNT_RECORD
1486471b825SIngo Molnar	select HAVE_FUNCTION_GRAPH_TRACER
1496471b825SIngo Molnar	select HAVE_FUNCTION_TRACER
1506b90bd4bSEmese Revfy	select HAVE_GCC_PLUGINS
1510067f129SK.Prasad	select HAVE_HW_BREAKPOINT
1526471b825SIngo Molnar	select HAVE_IDE
1536471b825SIngo Molnar	select HAVE_IOREMAP_PROT
1546471b825SIngo Molnar	select HAVE_IRQ_EXIT_ON_IRQ_STACK	if X86_64
1556471b825SIngo Molnar	select HAVE_IRQ_TIME_ACCOUNTING
1566471b825SIngo Molnar	select HAVE_KERNEL_BZIP2
1576471b825SIngo Molnar	select HAVE_KERNEL_GZIP
1586471b825SIngo Molnar	select HAVE_KERNEL_LZ4
1596471b825SIngo Molnar	select HAVE_KERNEL_LZMA
1606471b825SIngo Molnar	select HAVE_KERNEL_LZO
1616471b825SIngo Molnar	select HAVE_KERNEL_XZ
1626471b825SIngo Molnar	select HAVE_KPROBES
1636471b825SIngo Molnar	select HAVE_KPROBES_ON_FTRACE
164540adea3SMasami Hiramatsu	select HAVE_FUNCTION_ERROR_INJECTION
1656471b825SIngo Molnar	select HAVE_KRETPROBES
1666471b825SIngo Molnar	select HAVE_KVM
1676471b825SIngo Molnar	select HAVE_LIVEPATCH			if X86_64
1686471b825SIngo Molnar	select HAVE_MEMBLOCK
1696471b825SIngo Molnar	select HAVE_MEMBLOCK_NODE_MAP
1700102752eSFrederic Weisbecker	select HAVE_MIXED_BREAKPOINTS_REGS
171ee9f8fceSJosh Poimboeuf	select HAVE_MOD_ARCH_SPECIFIC
17242a0bb3fSPetr Mladek	select HAVE_NMI
1736471b825SIngo Molnar	select HAVE_OPROFILE
1746471b825SIngo Molnar	select HAVE_OPTPROBES
1756471b825SIngo Molnar	select HAVE_PCSPKR_PLATFORM
1766471b825SIngo Molnar	select HAVE_PERF_EVENTS
177c01d4323SFrederic Weisbecker	select HAVE_PERF_EVENTS_NMI
17892e5aae4SNicholas Piggin	select HAVE_HARDLOCKUP_DETECTOR_PERF	if PERF_EVENTS && HAVE_PERF_EVENTS_NMI
179c5e63197SJiri Olsa	select HAVE_PERF_REGS
180c5ebcedbSJiri Olsa	select HAVE_PERF_USER_STACK_DUMP
1819e52fc2bSVitaly Kuznetsov	select HAVE_RCU_TABLE_FREE
1826471b825SIngo Molnar	select HAVE_REGS_AND_STACK_ACCESS_API
18311af8474SJosh Poimboeuf	select HAVE_RELIABLE_STACKTRACE		if X86_64 && UNWINDER_FRAME_POINTER && STACK_VALIDATION
184d148eac0SMasahiro Yamada	select HAVE_STACKPROTECTOR		if CC_HAS_SANE_STACKPROTECTOR
185c763ea26SIngo Molnar	select HAVE_STACK_VALIDATION		if X86_64
186d6761b8fSMathieu Desnoyers	select HAVE_RSEQ
1876471b825SIngo Molnar	select HAVE_SYSCALL_TRACEPOINTS
1886471b825SIngo Molnar	select HAVE_UNSTABLE_SCHED_CLOCK
1897c68af6eSAvi Kivity	select HAVE_USER_RETURN_NOTIFIER
190*05736e4aSThomas Gleixner	select HOTPLUG_SMT			if SMP
191c0185808SThomas Gleixner	select IRQ_FORCED_THREADING
19286596f0aSChristoph Hellwig	select NEED_SG_DMA_LENGTH
193df65c1bcSThomas Gleixner	select PCI_LOCKLESS_CONFIG
1946471b825SIngo Molnar	select PERF_EVENTS
1953195ef59SPrarit Bhargava	select RTC_LIB
196d6faca40SArnd Bergmann	select RTC_MC146818_LIB
1976471b825SIngo Molnar	select SPARSE_IRQ
19883fe27eaSPranith Kumar	select SRCU
1996471b825SIngo Molnar	select SYSCTL_EXCEPTION_TRACE
20015f4eae7SAndy Lutomirski	select THREAD_INFO_IN_TASK
2016471b825SIngo Molnar	select USER_STACKTRACE_SUPPORT
2026471b825SIngo Molnar	select VIRT_TO_BUS
2036471b825SIngo Molnar	select X86_FEATURE_NAMES		if PROC_FS
2047d8330a5SBalbir Singh
205ba7e4d13SIngo Molnarconfig INSTRUCTION_DECODER
2063120e25eSJan Beulich	def_bool y
2073120e25eSJan Beulich	depends on KPROBES || PERF_EVENTS || UPROBES
208ba7e4d13SIngo Molnar
20951b26adaSLinus Torvaldsconfig OUTPUT_FORMAT
21051b26adaSLinus Torvalds	string
21151b26adaSLinus Torvalds	default "elf32-i386" if X86_32
21251b26adaSLinus Torvalds	default "elf64-x86-64" if X86_64
21351b26adaSLinus Torvalds
21473531905SSam Ravnborgconfig ARCH_DEFCONFIG
215b9b39bfbSSam Ravnborg	string
21673531905SSam Ravnborg	default "arch/x86/configs/i386_defconfig" if X86_32
21773531905SSam Ravnborg	default "arch/x86/configs/x86_64_defconfig" if X86_64
218b9b39bfbSSam Ravnborg
2198d5fffb9SSam Ravnborgconfig LOCKDEP_SUPPORT
2203c2362e6SHarvey Harrison	def_bool y
2218d5fffb9SSam Ravnborg
2228d5fffb9SSam Ravnborgconfig STACKTRACE_SUPPORT
2233c2362e6SHarvey Harrison	def_bool y
2248d5fffb9SSam Ravnborg
2258d5fffb9SSam Ravnborgconfig MMU
2263c2362e6SHarvey Harrison	def_bool y
2278d5fffb9SSam Ravnborg
2289e08f57dSDaniel Cashmanconfig ARCH_MMAP_RND_BITS_MIN
2299e08f57dSDaniel Cashman	default 28 if 64BIT
2309e08f57dSDaniel Cashman	default 8
2319e08f57dSDaniel Cashman
2329e08f57dSDaniel Cashmanconfig ARCH_MMAP_RND_BITS_MAX
2339e08f57dSDaniel Cashman	default 32 if 64BIT
2349e08f57dSDaniel Cashman	default 16
2359e08f57dSDaniel Cashman
2369e08f57dSDaniel Cashmanconfig ARCH_MMAP_RND_COMPAT_BITS_MIN
2379e08f57dSDaniel Cashman	default 8
2389e08f57dSDaniel Cashman
2399e08f57dSDaniel Cashmanconfig ARCH_MMAP_RND_COMPAT_BITS_MAX
2409e08f57dSDaniel Cashman	default 16
2419e08f57dSDaniel Cashman
2428d5fffb9SSam Ravnborgconfig SBUS
2438d5fffb9SSam Ravnborg	bool
2448d5fffb9SSam Ravnborg
2458d5fffb9SSam Ravnborgconfig GENERIC_ISA_DMA
2463120e25eSJan Beulich	def_bool y
2473120e25eSJan Beulich	depends on ISA_DMA_API
2488d5fffb9SSam Ravnborg
2498d5fffb9SSam Ravnborgconfig GENERIC_BUG
2503c2362e6SHarvey Harrison	def_bool y
2518d5fffb9SSam Ravnborg	depends on BUG
252b93a531eSJan Beulich	select GENERIC_BUG_RELATIVE_POINTERS if X86_64
253b93a531eSJan Beulich
254b93a531eSJan Beulichconfig GENERIC_BUG_RELATIVE_POINTERS
255b93a531eSJan Beulich	bool
2568d5fffb9SSam Ravnborg
2578d5fffb9SSam Ravnborgconfig GENERIC_HWEIGHT
2583c2362e6SHarvey Harrison	def_bool y
2598d5fffb9SSam Ravnborg
2608d5fffb9SSam Ravnborgconfig ARCH_MAY_HAVE_PC_FDC
2613120e25eSJan Beulich	def_bool y
2623120e25eSJan Beulich	depends on ISA_DMA_API
2638d5fffb9SSam Ravnborg
2641032c0baSSam Ravnborgconfig RWSEM_XCHGADD_ALGORITHM
2653120e25eSJan Beulich	def_bool y
2661032c0baSSam Ravnborg
2671032c0baSSam Ravnborgconfig GENERIC_CALIBRATE_DELAY
2681032c0baSSam Ravnborg	def_bool y
2691032c0baSSam Ravnborg
2709a0b8415Svenkatesh.pallipadi@intel.comconfig ARCH_HAS_CPU_RELAX
2719a0b8415Svenkatesh.pallipadi@intel.com	def_bool y
2728d5fffb9SSam Ravnborg
2731b27d05bSPekka Enbergconfig ARCH_HAS_CACHE_LINE_SIZE
2741b27d05bSPekka Enberg	def_bool y
2751b27d05bSPekka Enberg
276316d097cSDave Hansenconfig ARCH_HAS_FILTER_PGPROT
277316d097cSDave Hansen	def_bool y
278316d097cSDave Hansen
279dd5af90aSMike Travisconfig HAVE_SETUP_PER_CPU_AREA
28089c9c4c5SBrian Gerst	def_bool y
281b32ef636Stravis@sgi.com
28208fc4580STejun Heoconfig NEED_PER_CPU_EMBED_FIRST_CHUNK
28308fc4580STejun Heo	def_bool y
28408fc4580STejun Heo
28508fc4580STejun Heoconfig NEED_PER_CPU_PAGE_FIRST_CHUNK
28611124411STejun Heo	def_bool y
28711124411STejun Heo
288801e4062SJohannes Bergconfig ARCH_HIBERNATION_POSSIBLE
289801e4062SJohannes Berg	def_bool y
290801e4062SJohannes Berg
291f4cb5700SJohannes Bergconfig ARCH_SUSPEND_POSSIBLE
292f4cb5700SJohannes Berg	def_bool y
293f4cb5700SJohannes Berg
294cfe28c5dSSteve Capperconfig ARCH_WANT_HUGE_PMD_SHARE
295cfe28c5dSSteve Capper	def_bool y
296cfe28c5dSSteve Capper
29753313b2cSSteve Capperconfig ARCH_WANT_GENERAL_HUGETLB
29853313b2cSSteve Capper	def_bool y
29953313b2cSSteve Capper
3008d5fffb9SSam Ravnborgconfig ZONE_DMA32
301e0fd24a3SJan Beulich	def_bool y if X86_64
3028d5fffb9SSam Ravnborg
3038d5fffb9SSam Ravnborgconfig AUDIT_ARCH
304e0fd24a3SJan Beulich	def_bool y if X86_64
3058d5fffb9SSam Ravnborg
306765c68bdSIngo Molnarconfig ARCH_SUPPORTS_OPTIMIZED_INLINING
307765c68bdSIngo Molnar	def_bool y
308765c68bdSIngo Molnar
3096a11f75bSAkinobu Mitaconfig ARCH_SUPPORTS_DEBUG_PAGEALLOC
3106a11f75bSAkinobu Mita	def_bool y
3116a11f75bSAkinobu Mita
312d6f2d75aSAndrey Ryabininconfig KASAN_SHADOW_OFFSET
313d6f2d75aSAndrey Ryabinin	hex
314d6f2d75aSAndrey Ryabinin	depends on KASAN
315d6f2d75aSAndrey Ryabinin	default 0xdffffc0000000000
316d6f2d75aSAndrey Ryabinin
31769575d38SShane Wangconfig HAVE_INTEL_TXT
31869575d38SShane Wang	def_bool y
3196ea30386SKees Cook	depends on INTEL_IOMMU && ACPI
32069575d38SShane Wang
3216b0c3d44SSam Ravnborgconfig X86_32_SMP
3226b0c3d44SSam Ravnborg	def_bool y
3236b0c3d44SSam Ravnborg	depends on X86_32 && SMP
3246b0c3d44SSam Ravnborg
3256b0c3d44SSam Ravnborgconfig X86_64_SMP
3266b0c3d44SSam Ravnborg	def_bool y
3276b0c3d44SSam Ravnborg	depends on X86_64 && SMP
3286b0c3d44SSam Ravnborg
329ccbeed3aSTejun Heoconfig X86_32_LAZY_GS
330ccbeed3aSTejun Heo	def_bool y
3318458f8c2SMasahiro Yamada	depends on X86_32 && !STACKPROTECTOR
332ccbeed3aSTejun Heo
3332b144498SSrikar Dronamrajuconfig ARCH_SUPPORTS_UPROBES
3342b144498SSrikar Dronamraju	def_bool y
3352b144498SSrikar Dronamraju
336d20642f0SRob Herringconfig FIX_EARLYCON_MEM
337d20642f0SRob Herring	def_bool y
338d20642f0SRob Herring
33994d49eb3SKirill A. Shutemovconfig DYNAMIC_PHYSICAL_MASK
34094d49eb3SKirill A. Shutemov	bool
34194d49eb3SKirill A. Shutemov
34298233368SKirill A. Shutemovconfig PGTABLE_LEVELS
34398233368SKirill A. Shutemov	int
34477ef56e4SKirill A. Shutemov	default 5 if X86_5LEVEL
34598233368SKirill A. Shutemov	default 4 if X86_64
34698233368SKirill A. Shutemov	default 3 if X86_PAE
34798233368SKirill A. Shutemov	default 2
34898233368SKirill A. Shutemov
349506f1d07SSam Ravnborgsource "init/Kconfig"
3502a61f474SMasahiro Yamada
3512a61f474SMasahiro Yamadaconfig CC_HAS_SANE_STACKPROTECTOR
3522a61f474SMasahiro Yamada	bool
3532a61f474SMasahiro Yamada	default $(success,$(srctree)/scripts/gcc-x86_64-has-stack-protector.sh $(CC)) if 64BIT
3542a61f474SMasahiro Yamada	default $(success,$(srctree)/scripts/gcc-x86_32-has-stack-protector.sh $(CC))
3552a61f474SMasahiro Yamada	help
3562a61f474SMasahiro Yamada	   We have to make sure stack protector is unconditionally disabled if
3572a61f474SMasahiro Yamada	   the compiler produces broken code.
3582a61f474SMasahiro Yamada
359dc52ddc0SMatt Helsleysource "kernel/Kconfig.freezer"
3608d5fffb9SSam Ravnborg
361506f1d07SSam Ravnborgmenu "Processor type and features"
362506f1d07SSam Ravnborg
3635ee71535SRandy Dunlapconfig ZONE_DMA
3645ee71535SRandy Dunlap	bool "DMA memory allocation support" if EXPERT
3655ee71535SRandy Dunlap	default y
3665ee71535SRandy Dunlap	help
3675ee71535SRandy Dunlap	  DMA memory allocation support allows devices with less than 32-bit
3685ee71535SRandy Dunlap	  addressing to allocate within the first 16MB of address space.
3695ee71535SRandy Dunlap	  Disable if no such devices will be used.
3705ee71535SRandy Dunlap
3715ee71535SRandy Dunlap	  If unsure, say Y.
3725ee71535SRandy Dunlap
373506f1d07SSam Ravnborgconfig SMP
374506f1d07SSam Ravnborg	bool "Symmetric multi-processing support"
375506f1d07SSam Ravnborg	---help---
376506f1d07SSam Ravnborg	  This enables support for systems with more than one CPU. If you have
3774a474157SRobert Graffham	  a system with only one CPU, say N. If you have a system with more
3784a474157SRobert Graffham	  than one CPU, say Y.
379506f1d07SSam Ravnborg
3804a474157SRobert Graffham	  If you say N here, the kernel will run on uni- and multiprocessor
381506f1d07SSam Ravnborg	  machines, but will use only one CPU of a multiprocessor machine. If
382506f1d07SSam Ravnborg	  you say Y here, the kernel will run on many, but not all,
3834a474157SRobert Graffham	  uniprocessor machines. On a uniprocessor machine, the kernel
384506f1d07SSam Ravnborg	  will run faster if you say N here.
385506f1d07SSam Ravnborg
386506f1d07SSam Ravnborg	  Note that if you say Y here and choose architecture "586" or
387506f1d07SSam Ravnborg	  "Pentium" under "Processor family", the kernel will not work on 486
388506f1d07SSam Ravnborg	  architectures. Similarly, multiprocessor kernels for the "PPro"
389506f1d07SSam Ravnborg	  architecture may not work on all Pentium based boards.
390506f1d07SSam Ravnborg
391506f1d07SSam Ravnborg	  People using multiprocessor machines who say Y here should also say
392506f1d07SSam Ravnborg	  Y to "Enhanced Real Time Clock Support", below. The "Advanced Power
393506f1d07SSam Ravnborg	  Management" code will be disabled if you say Y here.
394506f1d07SSam Ravnborg
395395cf969SPaul Bolle	  See also <file:Documentation/x86/i386/IO-APIC.txt>,
396c9525a3fSBenjamin Peterson	  <file:Documentation/lockup-watchdogs.txt> and the SMP-HOWTO available at
397506f1d07SSam Ravnborg	  <http://www.tldp.org/docs.html#howto>.
398506f1d07SSam Ravnborg
399506f1d07SSam Ravnborg	  If you don't know what to do here, say N.
400506f1d07SSam Ravnborg
4019def39beSJosh Triplettconfig X86_FEATURE_NAMES
4029def39beSJosh Triplett	bool "Processor feature human-readable names" if EMBEDDED
4039def39beSJosh Triplett	default y
4049def39beSJosh Triplett	---help---
4059def39beSJosh Triplett	  This option compiles in a table of x86 feature bits and corresponding
4069def39beSJosh Triplett	  names.  This is required to support /proc/cpuinfo and a few kernel
4079def39beSJosh Triplett	  messages.  You can disable this to save space, at the expense of
4089def39beSJosh Triplett	  making those few kernel messages show numeric feature bits instead.
4099def39beSJosh Triplett
4109def39beSJosh Triplett	  If in doubt, say Y.
4119def39beSJosh Triplett
41206cd9a7dSYinghai Luconfig X86_X2APIC
41306cd9a7dSYinghai Lu	bool "Support x2apic"
41419e3d60dSJan Kiszka	depends on X86_LOCAL_APIC && X86_64 && (IRQ_REMAP || HYPERVISOR_GUEST)
41506cd9a7dSYinghai Lu	---help---
41606cd9a7dSYinghai Lu	  This enables x2apic support on CPUs that have this feature.
41706cd9a7dSYinghai Lu
41806cd9a7dSYinghai Lu	  This allows 32-bit apic IDs (so it can support very large systems),
41906cd9a7dSYinghai Lu	  and accesses the local apic via MSRs not via mmio.
42006cd9a7dSYinghai Lu
42106cd9a7dSYinghai Lu	  If you don't know what to do here, say N.
42206cd9a7dSYinghai Lu
4236695c85bSYinghai Luconfig X86_MPPARSE
4246e87f9b7SBin Gao	bool "Enable MPS table" if ACPI || SFI
4257a527688SJan Beulich	default y
4265ab74722SIngo Molnar	depends on X86_LOCAL_APIC
4278f9ca475SIngo Molnar	---help---
4286695c85bSYinghai Lu	  For old smp systems that do not have proper acpi support. Newer systems
4296695c85bSYinghai Lu	  (esp with 64bit cpus) with acpi support, MADT and DSDT will override it
4306695c85bSYinghai Lu
431ddd70cf9SJun Nakajimaconfig GOLDFISH
432ddd70cf9SJun Nakajima       def_bool y
433ddd70cf9SJun Nakajima       depends on X86_GOLDFISH
434ddd70cf9SJun Nakajima
43576b04384SDavid Woodhouseconfig RETPOLINE
43676b04384SDavid Woodhouse	bool "Avoid speculative indirect branches in kernel"
43776b04384SDavid Woodhouse	default y
438d5028ba8SPeter Zijlstra	select STACK_VALIDATION if HAVE_STACK_VALIDATION
43976b04384SDavid Woodhouse	help
44076b04384SDavid Woodhouse	  Compile kernel with the retpoline compiler options to guard against
44176b04384SDavid Woodhouse	  kernel-to-user data leaks by avoiding speculative indirect
44276b04384SDavid Woodhouse	  branches. Requires a compiler with -mindirect-branch=thunk-extern
44376b04384SDavid Woodhouse	  support for full protection. The kernel may run slower.
44476b04384SDavid Woodhouse
44576b04384SDavid Woodhouse	  Without compiler support, at least indirect branches in assembler
44676b04384SDavid Woodhouse	  code are eliminated. Since this includes the syscall entry path,
44776b04384SDavid Woodhouse	  it is not entirely pointless.
44876b04384SDavid Woodhouse
449f01d7d51SVikas Shivappaconfig INTEL_RDT
450f01d7d51SVikas Shivappa	bool "Intel Resource Director Technology support"
45178e99b4aSFenghua Yu	default n
45278e99b4aSFenghua Yu	depends on X86 && CPU_SUP_INTEL
45359fe5a77SThomas Gleixner	select KERNFS
45478e99b4aSFenghua Yu	help
455f01d7d51SVikas Shivappa	  Select to enable resource allocation and monitoring which are
456f01d7d51SVikas Shivappa	  sub-features of Intel Resource Director Technology(RDT). More
457f01d7d51SVikas Shivappa	  information about RDT can be found in the Intel x86
458f01d7d51SVikas Shivappa	  Architecture Software Developer Manual.
45978e99b4aSFenghua Yu
46078e99b4aSFenghua Yu	  Say N if unsure.
46178e99b4aSFenghua Yu
4628425091fSRavikiran G Thirumalaiif X86_32
463a0d0bb4dSRandy Dunlapconfig X86_BIGSMP
464a0d0bb4dSRandy Dunlap	bool "Support for big SMP systems with more than 8 CPUs"
465a0d0bb4dSRandy Dunlap	depends on SMP
466a0d0bb4dSRandy Dunlap	---help---
467a0d0bb4dSRandy Dunlap	  This option is needed for the systems that have more than 8 CPUs
468a0d0bb4dSRandy Dunlap
469c5c606d9SRavikiran G Thirumalaiconfig X86_EXTENDED_PLATFORM
470c5c606d9SRavikiran G Thirumalai	bool "Support for extended (non-PC) x86 platforms"
471c5c606d9SRavikiran G Thirumalai	default y
4728f9ca475SIngo Molnar	---help---
47306ac8346SIngo Molnar	  If you disable this option then the kernel will only support
47406ac8346SIngo Molnar	  standard PC platforms. (which covers the vast majority of
47506ac8346SIngo Molnar	  systems out there.)
47606ac8346SIngo Molnar
4778425091fSRavikiran G Thirumalai	  If you enable this option then you'll be able to select support
4788425091fSRavikiran G Thirumalai	  for the following (non-PC) 32 bit x86 platforms:
479cb7b8023SBen Hutchings		Goldfish (Android emulator)
4808425091fSRavikiran G Thirumalai		AMD Elan
4818425091fSRavikiran G Thirumalai		RDC R-321x SoC
4828425091fSRavikiran G Thirumalai		SGI 320/540 (Visual Workstation)
48383125a3aSAlessandro Rubini		STA2X11-based (e.g. Northville)
4843f4110a4SThomas Gleixner		Moorestown MID devices
48506ac8346SIngo Molnar
48606ac8346SIngo Molnar	  If you have one of these systems, or if you want to build a
48706ac8346SIngo Molnar	  generic distribution kernel, say Y here - otherwise say N.
4888425091fSRavikiran G Thirumalaiendif
48906ac8346SIngo Molnar
4908425091fSRavikiran G Thirumalaiif X86_64
4918425091fSRavikiran G Thirumalaiconfig X86_EXTENDED_PLATFORM
4928425091fSRavikiran G Thirumalai	bool "Support for extended (non-PC) x86 platforms"
4938425091fSRavikiran G Thirumalai	default y
4948425091fSRavikiran G Thirumalai	---help---
4958425091fSRavikiran G Thirumalai	  If you disable this option then the kernel will only support
4968425091fSRavikiran G Thirumalai	  standard PC platforms. (which covers the vast majority of
4978425091fSRavikiran G Thirumalai	  systems out there.)
4988425091fSRavikiran G Thirumalai
4998425091fSRavikiran G Thirumalai	  If you enable this option then you'll be able to select support
5008425091fSRavikiran G Thirumalai	  for the following (non-PC) 64 bit x86 platforms:
50144b111b5SSteffen Persvold		Numascale NumaChip
5028425091fSRavikiran G Thirumalai		ScaleMP vSMP
5038425091fSRavikiran G Thirumalai		SGI Ultraviolet
5048425091fSRavikiran G Thirumalai
5058425091fSRavikiran G Thirumalai	  If you have one of these systems, or if you want to build a
5068425091fSRavikiran G Thirumalai	  generic distribution kernel, say Y here - otherwise say N.
5078425091fSRavikiran G Thirumalaiendif
508c5c606d9SRavikiran G Thirumalai# This is an alphabetically sorted list of 64 bit extended platforms
509c5c606d9SRavikiran G Thirumalai# Please maintain the alphabetic order if and when there are additions
51044b111b5SSteffen Persvoldconfig X86_NUMACHIP
51144b111b5SSteffen Persvold	bool "Numascale NumaChip"
51244b111b5SSteffen Persvold	depends on X86_64
51344b111b5SSteffen Persvold	depends on X86_EXTENDED_PLATFORM
51444b111b5SSteffen Persvold	depends on NUMA
51544b111b5SSteffen Persvold	depends on SMP
51644b111b5SSteffen Persvold	depends on X86_X2APIC
517f9726bfdSDaniel J Blueman	depends on PCI_MMCONFIG
51844b111b5SSteffen Persvold	---help---
51944b111b5SSteffen Persvold	  Adds support for Numascale NumaChip large-SMP systems. Needed to
52044b111b5SSteffen Persvold	  enable more than ~168 cores.
52144b111b5SSteffen Persvold	  If you don't have one of these, you should say N here.
52203b48632SNick Piggin
5236a48565eSIngo Molnarconfig X86_VSMP
524c5c606d9SRavikiran G Thirumalai	bool "ScaleMP vSMP"
5256276a074SBorislav Petkov	select HYPERVISOR_GUEST
5266a48565eSIngo Molnar	select PARAVIRT
5276a48565eSIngo Molnar	depends on X86_64 && PCI
528c5c606d9SRavikiran G Thirumalai	depends on X86_EXTENDED_PLATFORM
529ead91d4bSShai Fultheim	depends on SMP
5308f9ca475SIngo Molnar	---help---
5316a48565eSIngo Molnar	  Support for ScaleMP vSMP systems.  Say 'Y' here if this kernel is
5326a48565eSIngo Molnar	  supposed to run on these EM64T-based machines.  Only choose this option
5336a48565eSIngo Molnar	  if you have one of these machines.
5346a48565eSIngo Molnar
535c5c606d9SRavikiran G Thirumalaiconfig X86_UV
536c5c606d9SRavikiran G Thirumalai	bool "SGI Ultraviolet"
537c5c606d9SRavikiran G Thirumalai	depends on X86_64
538c5c606d9SRavikiran G Thirumalai	depends on X86_EXTENDED_PLATFORM
53954c28d29SJack Steiner	depends on NUMA
5401ecb4ae5SAndrew Morton	depends on EFI
5419d6c26e7SSuresh Siddha	depends on X86_X2APIC
5421222e564SIngo Molnar	depends on PCI
543c5c606d9SRavikiran G Thirumalai	---help---
544c5c606d9SRavikiran G Thirumalai	  This option is needed in order to support SGI Ultraviolet systems.
545c5c606d9SRavikiran G Thirumalai	  If you don't have one of these, you should say N here.
546c5c606d9SRavikiran G Thirumalai
547c5c606d9SRavikiran G Thirumalai# Following is an alphabetically sorted list of 32 bit extended platforms
548c5c606d9SRavikiran G Thirumalai# Please maintain the alphabetic order if and when there are additions
549506f1d07SSam Ravnborg
550ddd70cf9SJun Nakajimaconfig X86_GOLDFISH
551ddd70cf9SJun Nakajima       bool "Goldfish (Virtual Platform)"
552cb7b8023SBen Hutchings       depends on X86_EXTENDED_PLATFORM
553ddd70cf9SJun Nakajima       ---help---
554ddd70cf9SJun Nakajima	 Enable support for the Goldfish virtual platform used primarily
555ddd70cf9SJun Nakajima	 for Android development. Unless you are building for the Android
556ddd70cf9SJun Nakajima	 Goldfish emulator say N here.
557ddd70cf9SJun Nakajima
558c751e17bSThomas Gleixnerconfig X86_INTEL_CE
559c751e17bSThomas Gleixner	bool "CE4100 TV platform"
560c751e17bSThomas Gleixner	depends on PCI
561c751e17bSThomas Gleixner	depends on PCI_GODIRECT
5626084a6e2SJiang Liu	depends on X86_IO_APIC
563c751e17bSThomas Gleixner	depends on X86_32
564c751e17bSThomas Gleixner	depends on X86_EXTENDED_PLATFORM
56537bc9f50SDirk Brandewie	select X86_REBOOTFIXUPS
566da6b737bSSebastian Andrzej Siewior	select OF
567da6b737bSSebastian Andrzej Siewior	select OF_EARLY_FLATTREE
568c751e17bSThomas Gleixner	---help---
569c751e17bSThomas Gleixner	  Select for the Intel CE media processor (CE4100) SOC.
570c751e17bSThomas Gleixner	  This option compiles in support for the CE4100 SOC for settop
571c751e17bSThomas Gleixner	  boxes and media devices.
572c751e17bSThomas Gleixner
5734cb9b00fSDavid Cohenconfig X86_INTEL_MID
57443605ef1SAlan Cox	bool "Intel MID platform support"
57543605ef1SAlan Cox	depends on X86_EXTENDED_PLATFORM
576edc6bc78SDavid Cohen	depends on X86_PLATFORM_DEVICES
5771ea7c673SAlan Cox	depends on PCI
5783fda5bb4SAndy Shevchenko	depends on X86_64 || (PCI_GOANY && X86_32)
5791ea7c673SAlan Cox	depends on X86_IO_APIC
5807c9c3a1eSAlan Cox	select SFI
5814cb9b00fSDavid Cohen	select I2C
5827c9c3a1eSAlan Cox	select DW_APB_TIMER
5831ea7c673SAlan Cox	select APB_TIMER
5841ea7c673SAlan Cox	select INTEL_SCU_IPC
58515a713dfSMika Westerberg	select MFD_INTEL_MSIC
5861ea7c673SAlan Cox	---help---
5874cb9b00fSDavid Cohen	  Select to build a kernel capable of supporting Intel MID (Mobile
5884cb9b00fSDavid Cohen	  Internet Device) platform systems which do not have the PCI legacy
5894cb9b00fSDavid Cohen	  interfaces. If you are building for a PC class system say N here.
5901ea7c673SAlan Cox
5914cb9b00fSDavid Cohen	  Intel MID platforms are based on an Intel processor and chipset which
5924cb9b00fSDavid Cohen	  consume less power than most of the x86 derivatives.
59343605ef1SAlan Cox
5948bbc2a13SBryan O'Donoghueconfig X86_INTEL_QUARK
5958bbc2a13SBryan O'Donoghue	bool "Intel Quark platform support"
5968bbc2a13SBryan O'Donoghue	depends on X86_32
5978bbc2a13SBryan O'Donoghue	depends on X86_EXTENDED_PLATFORM
5988bbc2a13SBryan O'Donoghue	depends on X86_PLATFORM_DEVICES
5998bbc2a13SBryan O'Donoghue	depends on X86_TSC
6008bbc2a13SBryan O'Donoghue	depends on PCI
6018bbc2a13SBryan O'Donoghue	depends on PCI_GOANY
6028bbc2a13SBryan O'Donoghue	depends on X86_IO_APIC
6038bbc2a13SBryan O'Donoghue	select IOSF_MBI
6048bbc2a13SBryan O'Donoghue	select INTEL_IMR
6059ab6eb51SAndy Shevchenko	select COMMON_CLK
6068bbc2a13SBryan O'Donoghue	---help---
6078bbc2a13SBryan O'Donoghue	  Select to include support for Quark X1000 SoC.
6088bbc2a13SBryan O'Donoghue	  Say Y here if you have a Quark based system such as the Arduino
6098bbc2a13SBryan O'Donoghue	  compatible Intel Galileo.
6108bbc2a13SBryan O'Donoghue
6113d48aab1SMika Westerbergconfig X86_INTEL_LPSS
6123d48aab1SMika Westerberg	bool "Intel Low Power Subsystem Support"
613eebb3e8dSAndy Shevchenko	depends on X86 && ACPI
6143d48aab1SMika Westerberg	select COMMON_CLK
6150f531431SMathias Nyman	select PINCTRL
616eebb3e8dSAndy Shevchenko	select IOSF_MBI
6173d48aab1SMika Westerberg	---help---
6183d48aab1SMika Westerberg	  Select to build support for Intel Low Power Subsystem such as
6193d48aab1SMika Westerberg	  found on Intel Lynxpoint PCH. Selecting this option enables
6200f531431SMathias Nyman	  things like clock tree (common clock framework) and pincontrol
6210f531431SMathias Nyman	  which are needed by the LPSS peripheral drivers.
6223d48aab1SMika Westerberg
62392082a88SKen Xueconfig X86_AMD_PLATFORM_DEVICE
62492082a88SKen Xue	bool "AMD ACPI2Platform devices support"
62592082a88SKen Xue	depends on ACPI
62692082a88SKen Xue	select COMMON_CLK
62792082a88SKen Xue	select PINCTRL
62892082a88SKen Xue	---help---
62992082a88SKen Xue	  Select to interpret AMD specific ACPI device to platform device
63092082a88SKen Xue	  such as I2C, UART, GPIO found on AMD Carrizo and later chipsets.
63192082a88SKen Xue	  I2C and UART depend on COMMON_CLK to set clock. GPIO driver is
63292082a88SKen Xue	  implemented under PINCTRL subsystem.
63392082a88SKen Xue
634ced3ce76SDavid E. Boxconfig IOSF_MBI
635ced3ce76SDavid E. Box	tristate "Intel SoC IOSF Sideband support for SoC platforms"
636ced3ce76SDavid E. Box	depends on PCI
637ced3ce76SDavid E. Box	---help---
638ced3ce76SDavid E. Box	  This option enables sideband register access support for Intel SoC
639ced3ce76SDavid E. Box	  platforms. On these platforms the IOSF sideband is used in lieu of
640ced3ce76SDavid E. Box	  MSR's for some register accesses, mostly but not limited to thermal
641ced3ce76SDavid E. Box	  and power. Drivers may query the availability of this device to
642ced3ce76SDavid E. Box	  determine if they need the sideband in order to work on these
643ced3ce76SDavid E. Box	  platforms. The sideband is available on the following SoC products.
644ced3ce76SDavid E. Box	  This list is not meant to be exclusive.
645ced3ce76SDavid E. Box	   - BayTrail
646ced3ce76SDavid E. Box	   - Braswell
647ced3ce76SDavid E. Box	   - Quark
648ced3ce76SDavid E. Box
649ced3ce76SDavid E. Box	  You should say Y if you are running a kernel on one of these SoC's.
650ced3ce76SDavid E. Box
651ed2226bdSDavid E. Boxconfig IOSF_MBI_DEBUG
652ed2226bdSDavid E. Box	bool "Enable IOSF sideband access through debugfs"
653ed2226bdSDavid E. Box	depends on IOSF_MBI && DEBUG_FS
654ed2226bdSDavid E. Box	---help---
655ed2226bdSDavid E. Box	  Select this option to expose the IOSF sideband access registers (MCR,
656ed2226bdSDavid E. Box	  MDR, MCRX) through debugfs to write and read register information from
657ed2226bdSDavid E. Box	  different units on the SoC. This is most useful for obtaining device
658ed2226bdSDavid E. Box	  state information for debug and analysis. As this is a general access
659ed2226bdSDavid E. Box	  mechanism, users of this option would have specific knowledge of the
660ed2226bdSDavid E. Box	  device they want to access.
661ed2226bdSDavid E. Box
662ed2226bdSDavid E. Box	  If you don't require the option or are in doubt, say N.
663ed2226bdSDavid E. Box
664c5c606d9SRavikiran G Thirumalaiconfig X86_RDC321X
665c5c606d9SRavikiran G Thirumalai	bool "RDC R-321x SoC"
666506f1d07SSam Ravnborg	depends on X86_32
667c5c606d9SRavikiran G Thirumalai	depends on X86_EXTENDED_PLATFORM
668c5c606d9SRavikiran G Thirumalai	select M486
669c5c606d9SRavikiran G Thirumalai	select X86_REBOOTFIXUPS
670c5c606d9SRavikiran G Thirumalai	---help---
671c5c606d9SRavikiran G Thirumalai	  This option is needed for RDC R-321x system-on-chip, also known
672c5c606d9SRavikiran G Thirumalai	  as R-8610-(G).
673c5c606d9SRavikiran G Thirumalai	  If you don't have one of these chips, you should say N here.
674c5c606d9SRavikiran G Thirumalai
675e0c7ae37SIngo Molnarconfig X86_32_NON_STANDARD
6769c398017SIngo Molnar	bool "Support non-standard 32-bit SMP architectures"
6779c398017SIngo Molnar	depends on X86_32 && SMP
678c5c606d9SRavikiran G Thirumalai	depends on X86_EXTENDED_PLATFORM
6798f9ca475SIngo Molnar	---help---
680b5660ba7SH. Peter Anvin	  This option compiles in the bigsmp and STA2X11 default
681b5660ba7SH. Peter Anvin	  subarchitectures.  It is intended for a generic binary
682b5660ba7SH. Peter Anvin	  kernel. If you select them all, kernel will probe it one by
683b5660ba7SH. Peter Anvin	  one and will fallback to default.
684d49c4288SYinghai Lu
685c5c606d9SRavikiran G Thirumalai# Alphabetically sorted list of Non standard 32 bit platforms
686d49c4288SYinghai Lu
687d949f36fSLinus Torvaldsconfig X86_SUPPORTS_MEMORY_FAILURE
6886fc108a0SJan Beulich	def_bool y
689d949f36fSLinus Torvalds	# MCE code calls memory_failure():
690d949f36fSLinus Torvalds	depends on X86_MCE
691d949f36fSLinus Torvalds	# On 32-bit this adds too big of NODES_SHIFT and we run out of page flags:
692d949f36fSLinus Torvalds	# On 32-bit SPARSEMEM adds too big of SECTIONS_WIDTH:
693d949f36fSLinus Torvalds	depends on X86_64 || !SPARSEMEM
694d949f36fSLinus Torvalds	select ARCH_SUPPORTS_MEMORY_FAILURE
695d949f36fSLinus Torvalds
69683125a3aSAlessandro Rubiniconfig STA2X11
69783125a3aSAlessandro Rubini	bool "STA2X11 Companion Chip Support"
69883125a3aSAlessandro Rubini	depends on X86_32_NON_STANDARD && PCI
699b6e05477SChristoph Hellwig	select ARCH_HAS_PHYS_TO_DMA
70083125a3aSAlessandro Rubini	select X86_DEV_DMA_OPS
70183125a3aSAlessandro Rubini	select X86_DMA_REMAP
70283125a3aSAlessandro Rubini	select SWIOTLB
70383125a3aSAlessandro Rubini	select MFD_STA2X11
7040145071bSLinus Walleij	select GPIOLIB
70583125a3aSAlessandro Rubini	default n
70683125a3aSAlessandro Rubini	---help---
70783125a3aSAlessandro Rubini	  This adds support for boards based on the STA2X11 IO-Hub,
70883125a3aSAlessandro Rubini	  a.k.a. "ConneXt". The chip is used in place of the standard
70983125a3aSAlessandro Rubini	  PC chipset, so all "standard" peripherals are missing. If this
71083125a3aSAlessandro Rubini	  option is selected the kernel will still be able to boot on
71183125a3aSAlessandro Rubini	  standard PC machines.
71283125a3aSAlessandro Rubini
71382148d1dSShérabconfig X86_32_IRIS
71482148d1dSShérab	tristate "Eurobraille/Iris poweroff module"
71582148d1dSShérab	depends on X86_32
71682148d1dSShérab	---help---
71782148d1dSShérab	  The Iris machines from EuroBraille do not have APM or ACPI support
71882148d1dSShérab	  to shut themselves down properly.  A special I/O sequence is
71982148d1dSShérab	  needed to do so, which is what this module does at
72082148d1dSShérab	  kernel shutdown.
72182148d1dSShérab
72282148d1dSShérab	  This is only for Iris machines from EuroBraille.
72382148d1dSShérab
72482148d1dSShérab	  If unused, say N.
72582148d1dSShérab
726ae1e9130SIngo Molnarconfig SCHED_OMIT_FRAME_POINTER
7273c2362e6SHarvey Harrison	def_bool y
7283c2362e6SHarvey Harrison	prompt "Single-depth WCHAN output"
729a87d0914SKen Chen	depends on X86
7308f9ca475SIngo Molnar	---help---
731506f1d07SSam Ravnborg	  Calculate simpler /proc/<PID>/wchan values. If this option
732506f1d07SSam Ravnborg	  is disabled then wchan values will recurse back to the
733506f1d07SSam Ravnborg	  caller function. This provides more accurate wchan values,
734506f1d07SSam Ravnborg	  at the expense of slightly more scheduling overhead.
735506f1d07SSam Ravnborg
736506f1d07SSam Ravnborg	  If in doubt, say "Y".
737506f1d07SSam Ravnborg
7386276a074SBorislav Petkovmenuconfig HYPERVISOR_GUEST
7396276a074SBorislav Petkov	bool "Linux guest support"
7408f9ca475SIngo Molnar	---help---
7416276a074SBorislav Petkov	  Say Y here to enable options for running Linux under various hyper-
7426276a074SBorislav Petkov	  visors. This option enables basic hypervisor detection and platform
7436276a074SBorislav Petkov	  setup.
744506f1d07SSam Ravnborg
7456276a074SBorislav Petkov	  If you say N, all options in this submenu will be skipped and
7466276a074SBorislav Petkov	  disabled, and Linux guest support won't be built in.
747506f1d07SSam Ravnborg
7486276a074SBorislav Petkovif HYPERVISOR_GUEST
749506f1d07SSam Ravnborg
750e61bd94aSEduardo Pereira Habkostconfig PARAVIRT
751e61bd94aSEduardo Pereira Habkost	bool "Enable paravirtualization code"
7528f9ca475SIngo Molnar	---help---
753e61bd94aSEduardo Pereira Habkost	  This changes the kernel so it can modify itself when it is run
754e61bd94aSEduardo Pereira Habkost	  under a hypervisor, potentially improving performance significantly
755e61bd94aSEduardo Pereira Habkost	  over full virtualization.  However, when run without a hypervisor
756e61bd94aSEduardo Pereira Habkost	  the kernel is theoretically slower and slightly larger.
757e61bd94aSEduardo Pereira Habkost
7586276a074SBorislav Petkovconfig PARAVIRT_DEBUG
7596276a074SBorislav Petkov	bool "paravirt-ops debugging"
7606276a074SBorislav Petkov	depends on PARAVIRT && DEBUG_KERNEL
7616276a074SBorislav Petkov	---help---
7626276a074SBorislav Petkov	  Enable to debug paravirt_ops internals.  Specifically, BUG if
7636276a074SBorislav Petkov	  a paravirt_op is missing when it is called.
7646276a074SBorislav Petkov
765b4ecc126SJeremy Fitzhardingeconfig PARAVIRT_SPINLOCKS
766b4ecc126SJeremy Fitzhardinge	bool "Paravirtualization layer for spinlocks"
7676ea30386SKees Cook	depends on PARAVIRT && SMP
768b4ecc126SJeremy Fitzhardinge	---help---
769b4ecc126SJeremy Fitzhardinge	  Paravirtualized spinlocks allow a pvops backend to replace the
770b4ecc126SJeremy Fitzhardinge	  spinlock implementation with something virtualization-friendly
771b4ecc126SJeremy Fitzhardinge	  (for example, block the virtual CPU rather than spinning).
772b4ecc126SJeremy Fitzhardinge
7734c4e4f61SRaghavendra K T	  It has a minimal impact on native kernels and gives a nice performance
7744c4e4f61SRaghavendra K T	  benefit on paravirtualized KVM / Xen kernels.
775b4ecc126SJeremy Fitzhardinge
7764c4e4f61SRaghavendra K T	  If you are unsure how to answer this question, answer Y.
777b4ecc126SJeremy Fitzhardinge
77845e898b7SWaiman Longconfig QUEUED_LOCK_STAT
77945e898b7SWaiman Long	bool "Paravirt queued spinlock statistics"
780cfd8983fSPeter Zijlstra	depends on PARAVIRT_SPINLOCKS && DEBUG_FS
78145e898b7SWaiman Long	---help---
78245e898b7SWaiman Long	  Enable the collection of statistical data on the slowpath
78345e898b7SWaiman Long	  behavior of paravirtualized queued spinlocks and report
78445e898b7SWaiman Long	  them on debugfs.
78545e898b7SWaiman Long
7866276a074SBorislav Petkovsource "arch/x86/xen/Kconfig"
7876276a074SBorislav Petkov
7886276a074SBorislav Petkovconfig KVM_GUEST
7896276a074SBorislav Petkov	bool "KVM Guest support (including kvmclock)"
7906276a074SBorislav Petkov	depends on PARAVIRT
7916276a074SBorislav Petkov	select PARAVIRT_CLOCK
7926276a074SBorislav Petkov	default y
7936276a074SBorislav Petkov	---help---
7946276a074SBorislav Petkov	  This option enables various optimizations for running under the KVM
7956276a074SBorislav Petkov	  hypervisor. It includes a paravirtualized clock, so that instead
7966276a074SBorislav Petkov	  of relying on a PIT (or probably other) emulation by the
7976276a074SBorislav Petkov	  underlying device model, the host provides the guest with
7986276a074SBorislav Petkov	  timing infrastructure such as time of day, and system time
7996276a074SBorislav Petkov
8001e20eb85SSrivatsa Vaddagiriconfig KVM_DEBUG_FS
8011e20eb85SSrivatsa Vaddagiri	bool "Enable debug information for KVM Guests in debugfs"
8021e20eb85SSrivatsa Vaddagiri	depends on KVM_GUEST && DEBUG_FS
8031e20eb85SSrivatsa Vaddagiri	default n
8041e20eb85SSrivatsa Vaddagiri	---help---
8051e20eb85SSrivatsa Vaddagiri	  This option enables collection of various statistics for KVM guest.
8061e20eb85SSrivatsa Vaddagiri	  Statistics are displayed in debugfs filesystem. Enabling this option
8071e20eb85SSrivatsa Vaddagiri	  may incur significant overhead.
8081e20eb85SSrivatsa Vaddagiri
8096276a074SBorislav Petkovconfig PARAVIRT_TIME_ACCOUNTING
8106276a074SBorislav Petkov	bool "Paravirtual steal time accounting"
8116276a074SBorislav Petkov	depends on PARAVIRT
8126276a074SBorislav Petkov	default n
8136276a074SBorislav Petkov	---help---
8146276a074SBorislav Petkov	  Select this option to enable fine granularity task steal time
8156276a074SBorislav Petkov	  accounting. Time spent executing other tasks in parallel with
8166276a074SBorislav Petkov	  the current vCPU is discounted from the vCPU power. To account for
8176276a074SBorislav Petkov	  that, there can be a small performance impact.
8186276a074SBorislav Petkov
8196276a074SBorislav Petkov	  If in doubt, say N here.
8206276a074SBorislav Petkov
8217af192c9SGerd Hoffmannconfig PARAVIRT_CLOCK
8227af192c9SGerd Hoffmann	bool
8237af192c9SGerd Hoffmann
8244a362601SJan Kiszkaconfig JAILHOUSE_GUEST
8254a362601SJan Kiszka	bool "Jailhouse non-root cell support"
826abde587bSArnd Bergmann	depends on X86_64 && PCI
82787e65d05SJan Kiszka	select X86_PM_TIMER
8284a362601SJan Kiszka	---help---
8294a362601SJan Kiszka	  This option allows to run Linux as guest in a Jailhouse non-root
8304a362601SJan Kiszka	  cell. You can leave this option disabled if you only want to start
8314a362601SJan Kiszka	  Jailhouse and run Linux afterwards in the root cell.
8324a362601SJan Kiszka
8336276a074SBorislav Petkovendif #HYPERVISOR_GUEST
83497349135SJeremy Fitzhardinge
83508677214SYinghai Luconfig NO_BOOTMEM
836774ea0bcSYinghai Lu	def_bool y
83708677214SYinghai Lu
838506f1d07SSam Ravnborgsource "arch/x86/Kconfig.cpu"
839506f1d07SSam Ravnborg
840506f1d07SSam Ravnborgconfig HPET_TIMER
8413c2362e6SHarvey Harrison	def_bool X86_64
842506f1d07SSam Ravnborg	prompt "HPET Timer Support" if X86_32
8438f9ca475SIngo Molnar	---help---
844506f1d07SSam Ravnborg	  Use the IA-PC HPET (High Precision Event Timer) to manage
845506f1d07SSam Ravnborg	  time in preference to the PIT and RTC, if a HPET is
846506f1d07SSam Ravnborg	  present.
847506f1d07SSam Ravnborg	  HPET is the next generation timer replacing legacy 8254s.
848506f1d07SSam Ravnborg	  The HPET provides a stable time base on SMP
849506f1d07SSam Ravnborg	  systems, unlike the TSC, but it is more expensive to access,
8504e7f9df2SMichael S. Tsirkin	  as it is off-chip.  The interface used is documented
8514e7f9df2SMichael S. Tsirkin	  in the HPET spec, revision 1.
852506f1d07SSam Ravnborg
853506f1d07SSam Ravnborg	  You can safely choose Y here.  However, HPET will only be
854506f1d07SSam Ravnborg	  activated if the platform and the BIOS support this feature.
855506f1d07SSam Ravnborg	  Otherwise the 8254 will be used for timing services.
856506f1d07SSam Ravnborg
857506f1d07SSam Ravnborg	  Choose N to continue using the legacy 8254 timer.
858506f1d07SSam Ravnborg
859506f1d07SSam Ravnborgconfig HPET_EMULATE_RTC
8603c2362e6SHarvey Harrison	def_bool y
8619d8af78bSBernhard Walle	depends on HPET_TIMER && (RTC=y || RTC=m || RTC_DRV_CMOS=m || RTC_DRV_CMOS=y)
862506f1d07SSam Ravnborg
863bb24c471SJacob Panconfig APB_TIMER
864933b9463SAlan Cox       def_bool y if X86_INTEL_MID
865933b9463SAlan Cox       prompt "Intel MID APB Timer Support" if X86_INTEL_MID
86606c3df49SJamie Iles       select DW_APB_TIMER
867a0c3832aSAlan Cox       depends on X86_INTEL_MID && SFI
868bb24c471SJacob Pan       help
869bb24c471SJacob Pan         APB timer is the replacement for 8254, HPET on X86 MID platforms.
870bb24c471SJacob Pan         The APBT provides a stable time base on SMP
871bb24c471SJacob Pan         systems, unlike the TSC, but it is more expensive to access,
872bb24c471SJacob Pan         as it is off-chip. APB timers are always running regardless of CPU
873bb24c471SJacob Pan         C states, they are used as per CPU clockevent device when possible.
874bb24c471SJacob Pan
8756a108a14SDavid Rientjes# Mark as expert because too many people got it wrong.
876506f1d07SSam Ravnborg# The code disables itself when not needed.
8777ae9392cSThomas Petazzoniconfig DMI
8787ae9392cSThomas Petazzoni	default y
879cf074402SArd Biesheuvel	select DMI_SCAN_MACHINE_NON_EFI_FALLBACK
8806a108a14SDavid Rientjes	bool "Enable DMI scanning" if EXPERT
8818f9ca475SIngo Molnar	---help---
8827ae9392cSThomas Petazzoni	  Enabled scanning of DMI to identify machine quirks. Say Y
8837ae9392cSThomas Petazzoni	  here unless you have verified that your setup is not
8847ae9392cSThomas Petazzoni	  affected by entries in the DMI blacklist. Required by PNP
8857ae9392cSThomas Petazzoni	  BIOS code.
8867ae9392cSThomas Petazzoni
887506f1d07SSam Ravnborgconfig GART_IOMMU
88838901f1cSAndi Kleen	bool "Old AMD GART IOMMU support"
889a4ce5a48SChristoph Hellwig	select IOMMU_HELPER
890506f1d07SSam Ravnborg	select SWIOTLB
89123ac4ae8SAndreas Herrmann	depends on X86_64 && PCI && AMD_NB
8928f9ca475SIngo Molnar	---help---
893ced3c42cSIngo Molnar	  Provides a driver for older AMD Athlon64/Opteron/Turion/Sempron
894ced3c42cSIngo Molnar	  GART based hardware IOMMUs.
895ced3c42cSIngo Molnar
896ced3c42cSIngo Molnar	  The GART supports full DMA access for devices with 32-bit access
897ced3c42cSIngo Molnar	  limitations, on systems with more than 3 GB. This is usually needed
898ced3c42cSIngo Molnar	  for USB, sound, many IDE/SATA chipsets and some other devices.
899ced3c42cSIngo Molnar
900ced3c42cSIngo Molnar	  Newer systems typically have a modern AMD IOMMU, supported via
901ced3c42cSIngo Molnar	  the CONFIG_AMD_IOMMU=y config option.
902ced3c42cSIngo Molnar
903ced3c42cSIngo Molnar	  In normal configurations this driver is only active when needed:
904ced3c42cSIngo Molnar	  there's more than 3 GB of memory and the system contains a
905ced3c42cSIngo Molnar	  32-bit limited device.
906ced3c42cSIngo Molnar
907ced3c42cSIngo Molnar	  If unsure, say Y.
908506f1d07SSam Ravnborg
909506f1d07SSam Ravnborgconfig CALGARY_IOMMU
910506f1d07SSam Ravnborg	bool "IBM Calgary IOMMU support"
911a4ce5a48SChristoph Hellwig	select IOMMU_HELPER
912506f1d07SSam Ravnborg	select SWIOTLB
9136ea30386SKees Cook	depends on X86_64 && PCI
9148f9ca475SIngo Molnar	---help---
915506f1d07SSam Ravnborg	  Support for hardware IOMMUs in IBM's xSeries x366 and x460
916506f1d07SSam Ravnborg	  systems. Needed to run systems with more than 3GB of memory
917506f1d07SSam Ravnborg	  properly with 32-bit PCI devices that do not support DAC
918506f1d07SSam Ravnborg	  (Double Address Cycle). Calgary also supports bus level
919506f1d07SSam Ravnborg	  isolation, where all DMAs pass through the IOMMU.  This
920506f1d07SSam Ravnborg	  prevents them from going anywhere except their intended
921506f1d07SSam Ravnborg	  destination. This catches hard-to-find kernel bugs and
922506f1d07SSam Ravnborg	  mis-behaving drivers and devices that do not use the DMA-API
923506f1d07SSam Ravnborg	  properly to set up their DMA buffers.  The IOMMU can be
924506f1d07SSam Ravnborg	  turned off at boot time with the iommu=off parameter.
925506f1d07SSam Ravnborg	  Normally the kernel will make the right choice by itself.
926506f1d07SSam Ravnborg	  If unsure, say Y.
927506f1d07SSam Ravnborg
928506f1d07SSam Ravnborgconfig CALGARY_IOMMU_ENABLED_BY_DEFAULT
9293c2362e6SHarvey Harrison	def_bool y
9303c2362e6SHarvey Harrison	prompt "Should Calgary be enabled by default?"
931506f1d07SSam Ravnborg	depends on CALGARY_IOMMU
9328f9ca475SIngo Molnar	---help---
933506f1d07SSam Ravnborg	  Should Calgary be enabled by default? if you choose 'y', Calgary
934506f1d07SSam Ravnborg	  will be used (if it exists). If you choose 'n', Calgary will not be
935506f1d07SSam Ravnborg	  used even if it exists. If you choose 'n' and would like to use
936506f1d07SSam Ravnborg	  Calgary anyway, pass 'iommu=calgary' on the kernel command line.
937506f1d07SSam Ravnborg	  If unsure, say Y.
938506f1d07SSam Ravnborg
9391184dc2fSMike Travisconfig MAXSMP
940ddb0c5a6SSamuel Thibault	bool "Enable Maximum number of SMP Processors and NUMA Nodes"
9416ea30386SKees Cook	depends on X86_64 && SMP && DEBUG_KERNEL
94236f5101aSMike Travis	select CPUMASK_OFFSTACK
9438f9ca475SIngo Molnar	---help---
944ddb0c5a6SSamuel Thibault	  Enable maximum number of CPUS and NUMA Nodes for this architecture.
9451184dc2fSMike Travis	  If unsure, say N.
946506f1d07SSam Ravnborg
947aec6487eSIngo Molnar#
948aec6487eSIngo Molnar# The maximum number of CPUs supported:
949aec6487eSIngo Molnar#
950aec6487eSIngo Molnar# The main config value is NR_CPUS, which defaults to NR_CPUS_DEFAULT,
951aec6487eSIngo Molnar# and which can be configured interactively in the
952aec6487eSIngo Molnar# [NR_CPUS_RANGE_BEGIN ... NR_CPUS_RANGE_END] range.
953aec6487eSIngo Molnar#
954aec6487eSIngo Molnar# The ranges are different on 32-bit and 64-bit kernels, depending on
955aec6487eSIngo Molnar# hardware capabilities and scalability features of the kernel.
956aec6487eSIngo Molnar#
957aec6487eSIngo Molnar# ( If MAXSMP is enabled we just use the highest possible value and disable
958aec6487eSIngo Molnar#   interactive configuration. )
959aec6487eSIngo Molnar#
960a0d0bb4dSRandy Dunlap
961aec6487eSIngo Molnarconfig NR_CPUS_RANGE_BEGIN
962a0d0bb4dSRandy Dunlap	int
963aec6487eSIngo Molnar	default NR_CPUS_RANGE_END if MAXSMP
964a0d0bb4dSRandy Dunlap	default    1 if !SMP
965a0d0bb4dSRandy Dunlap	default    2
966a0d0bb4dSRandy Dunlap
967aec6487eSIngo Molnarconfig NR_CPUS_RANGE_END
968a0d0bb4dSRandy Dunlap	int
969a0d0bb4dSRandy Dunlap	depends on X86_32
970aec6487eSIngo Molnar	default   64 if  SMP &&  X86_BIGSMP
971aec6487eSIngo Molnar	default    8 if  SMP && !X86_BIGSMP
972a0d0bb4dSRandy Dunlap	default    1 if !SMP
973a0d0bb4dSRandy Dunlap
974aec6487eSIngo Molnarconfig NR_CPUS_RANGE_END
975a0d0bb4dSRandy Dunlap	int
976a0d0bb4dSRandy Dunlap	depends on X86_64
977aec6487eSIngo Molnar	default 8192 if  SMP && ( MAXSMP ||  CPUMASK_OFFSTACK)
978aec6487eSIngo Molnar	default  512 if  SMP && (!MAXSMP && !CPUMASK_OFFSTACK)
979a0d0bb4dSRandy Dunlap	default    1 if !SMP
980aec6487eSIngo Molnar
981aec6487eSIngo Molnarconfig NR_CPUS_DEFAULT
982aec6487eSIngo Molnar	int
983aec6487eSIngo Molnar	depends on X86_32
984aec6487eSIngo Molnar	default   32 if  X86_BIGSMP
985aec6487eSIngo Molnar	default    8 if  SMP
986aec6487eSIngo Molnar	default    1 if !SMP
987aec6487eSIngo Molnar
988aec6487eSIngo Molnarconfig NR_CPUS_DEFAULT
989aec6487eSIngo Molnar	int
990aec6487eSIngo Molnar	depends on X86_64
991a0d0bb4dSRandy Dunlap	default 8192 if  MAXSMP
992a0d0bb4dSRandy Dunlap	default   64 if  SMP
993aec6487eSIngo Molnar	default    1 if !SMP
994a0d0bb4dSRandy Dunlap
995506f1d07SSam Ravnborgconfig NR_CPUS
99636f5101aSMike Travis	int "Maximum number of CPUs" if SMP && !MAXSMP
997aec6487eSIngo Molnar	range NR_CPUS_RANGE_BEGIN NR_CPUS_RANGE_END
998aec6487eSIngo Molnar	default NR_CPUS_DEFAULT
9998f9ca475SIngo Molnar	---help---
1000506f1d07SSam Ravnborg	  This allows you to specify the maximum number of CPUs which this
1001bb61ccc7SJosh Boyer	  kernel will support.  If CPUMASK_OFFSTACK is enabled, the maximum
1002cad14bb9SKirill A. Shutemov	  supported value is 8192, otherwise the maximum value is 512.  The
1003506f1d07SSam Ravnborg	  minimum value which makes sense is 2.
1004506f1d07SSam Ravnborg
1005aec6487eSIngo Molnar	  This is purely to save memory: each supported CPU adds about 8KB
1006aec6487eSIngo Molnar	  to the kernel image.
1007506f1d07SSam Ravnborg
1008506f1d07SSam Ravnborgconfig SCHED_SMT
1009506f1d07SSam Ravnborg	bool "SMT (Hyperthreading) scheduler support"
1010c8e56d20SBorislav Petkov	depends on SMP
10118f9ca475SIngo Molnar	---help---
1012506f1d07SSam Ravnborg	  SMT scheduler support improves the CPU scheduler's decision making
1013506f1d07SSam Ravnborg	  when dealing with Intel Pentium 4 chips with HyperThreading at a
1014506f1d07SSam Ravnborg	  cost of slightly increased overhead in some places. If unsure say
1015506f1d07SSam Ravnborg	  N here.
1016506f1d07SSam Ravnborg
1017506f1d07SSam Ravnborgconfig SCHED_MC
10183c2362e6SHarvey Harrison	def_bool y
10193c2362e6SHarvey Harrison	prompt "Multi-core scheduler support"
1020c8e56d20SBorislav Petkov	depends on SMP
10218f9ca475SIngo Molnar	---help---
1022506f1d07SSam Ravnborg	  Multi-core scheduler support improves the CPU scheduler's decision
1023506f1d07SSam Ravnborg	  making when dealing with multi-core CPU chips at a cost of slightly
1024506f1d07SSam Ravnborg	  increased overhead in some places. If unsure say N here.
1025506f1d07SSam Ravnborg
1026de966cf4STim Chenconfig SCHED_MC_PRIO
1027de966cf4STim Chen	bool "CPU core priorities scheduler support"
10280a21fc12SIngo Molnar	depends on SCHED_MC && CPU_SUP_INTEL
10290a21fc12SIngo Molnar	select X86_INTEL_PSTATE
10300a21fc12SIngo Molnar	select CPU_FREQ
1031de966cf4STim Chen	default y
10325e76b2abSTim Chen	---help---
1033de966cf4STim Chen	  Intel Turbo Boost Max Technology 3.0 enabled CPUs have a
1034de966cf4STim Chen	  core ordering determined at manufacturing time, which allows
1035de966cf4STim Chen	  certain cores to reach higher turbo frequencies (when running
1036de966cf4STim Chen	  single threaded workloads) than others.
1037de966cf4STim Chen
1038de966cf4STim Chen	  Enabling this kernel feature teaches the scheduler about
1039de966cf4STim Chen	  the TBM3 (aka ITMT) priority order of the CPU cores and adjusts the
1040de966cf4STim Chen	  scheduler's CPU selection logic accordingly, so that higher
1041de966cf4STim Chen	  overall system performance can be achieved.
1042de966cf4STim Chen
1043de966cf4STim Chen	  This feature will have no effect on CPUs without this feature.
1044de966cf4STim Chen
1045de966cf4STim Chen	  If unsure say Y here.
10465e76b2abSTim Chen
1047506f1d07SSam Ravnborgsource "kernel/Kconfig.preempt"
1048506f1d07SSam Ravnborg
104930b8b006SThomas Gleixnerconfig UP_LATE_INIT
105030b8b006SThomas Gleixner       def_bool y
1051ba360f88SThomas Gleixner       depends on !SMP && X86_LOCAL_APIC
105230b8b006SThomas Gleixner
1053506f1d07SSam Ravnborgconfig X86_UP_APIC
105450849eefSJan Beulich	bool "Local APIC support on uniprocessors" if !PCI_MSI
105550849eefSJan Beulich	default PCI_MSI
105638a1dfdaSBryan O'Donoghue	depends on X86_32 && !SMP && !X86_32_NON_STANDARD
10578f9ca475SIngo Molnar	---help---
1058506f1d07SSam Ravnborg	  A local APIC (Advanced Programmable Interrupt Controller) is an
1059506f1d07SSam Ravnborg	  integrated interrupt controller in the CPU. If you have a single-CPU
1060506f1d07SSam Ravnborg	  system which has a processor with a local APIC, you can say Y here to
1061506f1d07SSam Ravnborg	  enable and use it. If you say Y here even though your machine doesn't
1062506f1d07SSam Ravnborg	  have a local APIC, then the kernel will still run with no slowdown at
1063506f1d07SSam Ravnborg	  all. The local APIC supports CPU-generated self-interrupts (timer,
1064506f1d07SSam Ravnborg	  performance counters), and the NMI watchdog which detects hard
1065506f1d07SSam Ravnborg	  lockups.
1066506f1d07SSam Ravnborg
1067506f1d07SSam Ravnborgconfig X86_UP_IOAPIC
1068506f1d07SSam Ravnborg	bool "IO-APIC support on uniprocessors"
1069506f1d07SSam Ravnborg	depends on X86_UP_APIC
10708f9ca475SIngo Molnar	---help---
1071506f1d07SSam Ravnborg	  An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an
1072506f1d07SSam Ravnborg	  SMP-capable replacement for PC-style interrupt controllers. Most
1073506f1d07SSam Ravnborg	  SMP systems and many recent uniprocessor systems have one.
1074506f1d07SSam Ravnborg
1075506f1d07SSam Ravnborg	  If you have a single-CPU system with an IO-APIC, you can say Y here
1076506f1d07SSam Ravnborg	  to use it. If you say Y here even though your machine doesn't have
1077506f1d07SSam Ravnborg	  an IO-APIC, then the kernel will still run with no slowdown at all.
1078506f1d07SSam Ravnborg
1079506f1d07SSam Ravnborgconfig X86_LOCAL_APIC
10803c2362e6SHarvey Harrison	def_bool y
10810dbc6078SThomas Petazzoni	depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC || PCI_MSI
1082b5dc8e6cSJiang Liu	select IRQ_DOMAIN_HIERARCHY
108352f518a3SJiang Liu	select PCI_MSI_IRQ_DOMAIN if PCI_MSI
1084506f1d07SSam Ravnborg
1085506f1d07SSam Ravnborgconfig X86_IO_APIC
1086b1da1e71SJan Beulich	def_bool y
1087b1da1e71SJan Beulich	depends on X86_LOCAL_APIC || X86_UP_IOAPIC
1088506f1d07SSam Ravnborg
108941b9eb26SStefan Assmannconfig X86_REROUTE_FOR_BROKEN_BOOT_IRQS
109041b9eb26SStefan Assmann	bool "Reroute for broken boot IRQs"
109141b9eb26SStefan Assmann	depends on X86_IO_APIC
10928f9ca475SIngo Molnar	---help---
109341b9eb26SStefan Assmann	  This option enables a workaround that fixes a source of
109441b9eb26SStefan Assmann	  spurious interrupts. This is recommended when threaded
109541b9eb26SStefan Assmann	  interrupt handling is used on systems where the generation of
109641b9eb26SStefan Assmann	  superfluous "boot interrupts" cannot be disabled.
109741b9eb26SStefan Assmann
109841b9eb26SStefan Assmann	  Some chipsets generate a legacy INTx "boot IRQ" when the IRQ
109941b9eb26SStefan Assmann	  entry in the chipset's IO-APIC is masked (as, e.g. the RT
110041b9eb26SStefan Assmann	  kernel does during interrupt handling). On chipsets where this
110141b9eb26SStefan Assmann	  boot IRQ generation cannot be disabled, this workaround keeps
110241b9eb26SStefan Assmann	  the original IRQ line masked so that only the equivalent "boot
110341b9eb26SStefan Assmann	  IRQ" is delivered to the CPUs. The workaround also tells the
110441b9eb26SStefan Assmann	  kernel to set up the IRQ handler on the boot IRQ line. In this
110541b9eb26SStefan Assmann	  way only one interrupt is delivered to the kernel. Otherwise
110641b9eb26SStefan Assmann	  the spurious second interrupt may cause the kernel to bring
110741b9eb26SStefan Assmann	  down (vital) interrupt lines.
110841b9eb26SStefan Assmann
110941b9eb26SStefan Assmann	  Only affects "broken" chipsets. Interrupt sharing may be
111041b9eb26SStefan Assmann	  increased on these systems.
111141b9eb26SStefan Assmann
1112506f1d07SSam Ravnborgconfig X86_MCE
1113bab9bc65SAndi Kleen	bool "Machine Check / overheating reporting"
1114648ed940SChen, Gong	select GENERIC_ALLOCATOR
1115e57dbaf7SBorislav Petkov	default y
1116506f1d07SSam Ravnborg	---help---
1117bab9bc65SAndi Kleen	  Machine Check support allows the processor to notify the
1118bab9bc65SAndi Kleen	  kernel if it detects a problem (e.g. overheating, data corruption).
1119506f1d07SSam Ravnborg	  The action the kernel takes depends on the severity of the problem,
1120bab9bc65SAndi Kleen	  ranging from warning messages to halting the machine.
11214efc0670SAndi Kleen
11225de97c9fSTony Luckconfig X86_MCELOG_LEGACY
11235de97c9fSTony Luck	bool "Support for deprecated /dev/mcelog character device"
11245de97c9fSTony Luck	depends on X86_MCE
11255de97c9fSTony Luck	---help---
11265de97c9fSTony Luck	  Enable support for /dev/mcelog which is needed by the old mcelog
11275de97c9fSTony Luck	  userspace logging daemon. Consider switching to the new generation
11285de97c9fSTony Luck	  rasdaemon solution.
11295de97c9fSTony Luck
1130506f1d07SSam Ravnborgconfig X86_MCE_INTEL
11313c2362e6SHarvey Harrison	def_bool y
11323c2362e6SHarvey Harrison	prompt "Intel MCE features"
1133c1ebf835SAndi Kleen	depends on X86_MCE && X86_LOCAL_APIC
11348f9ca475SIngo Molnar	---help---
1135506f1d07SSam Ravnborg	   Additional support for intel specific MCE features such as
1136506f1d07SSam Ravnborg	   the thermal monitor.
1137506f1d07SSam Ravnborg
1138506f1d07SSam Ravnborgconfig X86_MCE_AMD
11393c2362e6SHarvey Harrison	def_bool y
11403c2362e6SHarvey Harrison	prompt "AMD MCE features"
1141f5382de9SYazen Ghannam	depends on X86_MCE && X86_LOCAL_APIC && AMD_NB
11428f9ca475SIngo Molnar	---help---
1143506f1d07SSam Ravnborg	   Additional support for AMD specific MCE features such as
1144506f1d07SSam Ravnborg	   the DRAM Error Threshold.
1145506f1d07SSam Ravnborg
11464efc0670SAndi Kleenconfig X86_ANCIENT_MCE
11476fc108a0SJan Beulich	bool "Support for old Pentium 5 / WinChip machine checks"
1148c31d9633SAndi Kleen	depends on X86_32 && X86_MCE
11494efc0670SAndi Kleen	---help---
11504efc0670SAndi Kleen	  Include support for machine check handling on old Pentium 5 or WinChip
11515065a706SMasanari Iida	  systems. These typically need to be enabled explicitly on the command
11524efc0670SAndi Kleen	  line.
11534efc0670SAndi Kleen
1154b2762686SAndi Kleenconfig X86_MCE_THRESHOLD
1155b2762686SAndi Kleen	depends on X86_MCE_AMD || X86_MCE_INTEL
11566fc108a0SJan Beulich	def_bool y
1157b2762686SAndi Kleen
1158ea149b36SAndi Kleenconfig X86_MCE_INJECT
1159bc8e80d5SBorislav Petkov	depends on X86_MCE && X86_LOCAL_APIC && DEBUG_FS
1160ea149b36SAndi Kleen	tristate "Machine check injector support"
1161ea149b36SAndi Kleen	---help---
1162ea149b36SAndi Kleen	  Provide support for injecting machine checks for testing purposes.
1163ea149b36SAndi Kleen	  If you don't know what a machine check is and you don't do kernel
1164ea149b36SAndi Kleen	  QA it is safe to say n.
1165ea149b36SAndi Kleen
11664efc0670SAndi Kleenconfig X86_THERMAL_VECTOR
11674efc0670SAndi Kleen	def_bool y
11685bb38adcSAndi Kleen	depends on X86_MCE_INTEL
11694efc0670SAndi Kleen
117007dc900eSPeter Zijlstrasource "arch/x86/events/Kconfig"
1171e633c65aSKan Liang
11725aef51c3SAndy Lutomirskiconfig X86_LEGACY_VM86
11731e642812SIngo Molnar	bool "Legacy VM86 support"
11745aef51c3SAndy Lutomirski	default n
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
14977744ccdbSTom Lendackyconfig ARCH_HAS_MEM_ENCRYPT
14987744ccdbSTom Lendacky	def_bool y
14997744ccdbSTom Lendacky
15007744ccdbSTom Lendackyconfig AMD_MEM_ENCRYPT
15017744ccdbSTom Lendacky	bool "AMD Secure Memory Encryption (SME) support"
15027744ccdbSTom Lendacky	depends on X86_64 && CPU_SUP_AMD
150394d49eb3SKirill A. Shutemov	select DYNAMIC_PHYSICAL_MASK
15047744ccdbSTom Lendacky	---help---
15057744ccdbSTom Lendacky	  Say yes to enable support for the encryption of system memory.
15067744ccdbSTom Lendacky	  This requires an AMD processor that supports Secure Memory
15077744ccdbSTom Lendacky	  Encryption (SME).
15087744ccdbSTom Lendacky
15097744ccdbSTom Lendackyconfig AMD_MEM_ENCRYPT_ACTIVE_BY_DEFAULT
15107744ccdbSTom Lendacky	bool "Activate AMD Secure Memory Encryption (SME) by default"
15117744ccdbSTom Lendacky	default y
15127744ccdbSTom Lendacky	depends on AMD_MEM_ENCRYPT
15137744ccdbSTom Lendacky	---help---
15147744ccdbSTom Lendacky	  Say yes to have system memory encrypted by default if running on
15157744ccdbSTom Lendacky	  an AMD processor that supports Secure Memory Encryption (SME).
15167744ccdbSTom Lendacky
15177744ccdbSTom Lendacky	  If set to Y, then the encryption of system memory can be
15187744ccdbSTom Lendacky	  deactivated with the mem_encrypt=off command line option.
15197744ccdbSTom Lendacky
15207744ccdbSTom Lendacky	  If set to N, then the encryption of system memory can be
15217744ccdbSTom Lendacky	  activated with the mem_encrypt=on command line option.
15227744ccdbSTom Lendacky
1523f88a68faSTom Lendackyconfig ARCH_USE_MEMREMAP_PROT
1524f88a68faSTom Lendacky	def_bool y
1525f88a68faSTom Lendacky	depends on AMD_MEM_ENCRYPT
1526f88a68faSTom Lendacky
1527506f1d07SSam Ravnborg# Common NUMA Features
1528506f1d07SSam Ravnborgconfig NUMA
1529fd51b2d7SKOSAKI Motohiro	bool "Numa Memory Allocation and Scheduler Support"
1530506f1d07SSam Ravnborg	depends on SMP
1531b5660ba7SH. Peter Anvin	depends on X86_64 || (X86_32 && HIGHMEM64G && X86_BIGSMP)
1532b5660ba7SH. Peter Anvin	default y if X86_BIGSMP
15338f9ca475SIngo Molnar	---help---
1534506f1d07SSam Ravnborg	  Enable NUMA (Non Uniform Memory Access) support.
1535fd51b2d7SKOSAKI Motohiro
1536506f1d07SSam Ravnborg	  The kernel will try to allocate memory used by a CPU on the
1537506f1d07SSam Ravnborg	  local memory controller of the CPU and add some more
1538506f1d07SSam Ravnborg	  NUMA awareness to the kernel.
1539506f1d07SSam Ravnborg
1540c280ea5eSIngo Molnar	  For 64-bit this is recommended if the system is Intel Core i7
1541fd51b2d7SKOSAKI Motohiro	  (or later), AMD Opteron, or EM64T NUMA.
1542fd51b2d7SKOSAKI Motohiro
1543b5660ba7SH. Peter Anvin	  For 32-bit this is only needed if you boot a 32-bit
15447cf6c945SDavid Rientjes	  kernel on a 64-bit NUMA platform.
1545fd51b2d7SKOSAKI Motohiro
1546fd51b2d7SKOSAKI Motohiro	  Otherwise, you should say N.
1547506f1d07SSam Ravnborg
1548eec1d4faSHans Rosenfeldconfig AMD_NUMA
15493c2362e6SHarvey Harrison	def_bool y
15503c2362e6SHarvey Harrison	prompt "Old style AMD Opteron NUMA detection"
15515da0ef9aSTejun Heo	depends on X86_64 && NUMA && PCI
15528f9ca475SIngo Molnar	---help---
1553eec1d4faSHans Rosenfeld	  Enable AMD NUMA node topology detection.  You should say Y here if
1554eec1d4faSHans Rosenfeld	  you have a multi processor AMD system. This uses an old method to
1555eec1d4faSHans Rosenfeld	  read the NUMA configuration directly from the builtin Northbridge
1556eec1d4faSHans Rosenfeld	  of Opteron. It is recommended to use X86_64_ACPI_NUMA instead,
1557eec1d4faSHans Rosenfeld	  which also takes priority if both are compiled in.
1558506f1d07SSam Ravnborg
1559506f1d07SSam Ravnborgconfig X86_64_ACPI_NUMA
15603c2362e6SHarvey Harrison	def_bool y
15613c2362e6SHarvey Harrison	prompt "ACPI NUMA detection"
1562506f1d07SSam Ravnborg	depends on X86_64 && NUMA && ACPI && PCI
1563506f1d07SSam Ravnborg	select ACPI_NUMA
15648f9ca475SIngo Molnar	---help---
1565506f1d07SSam Ravnborg	  Enable ACPI SRAT based node topology detection.
1566506f1d07SSam Ravnborg
15676ec6e0d9SSuresh Siddha# Some NUMA nodes have memory ranges that span
15686ec6e0d9SSuresh Siddha# other nodes.  Even though a pfn is valid and
15696ec6e0d9SSuresh Siddha# between a node's start and end pfns, it may not
15706ec6e0d9SSuresh Siddha# reside on that node.  See memmap_init_zone()
15716ec6e0d9SSuresh Siddha# for details.
15726ec6e0d9SSuresh Siddhaconfig NODES_SPAN_OTHER_NODES
15736ec6e0d9SSuresh Siddha	def_bool y
15746ec6e0d9SSuresh Siddha	depends on X86_64_ACPI_NUMA
15756ec6e0d9SSuresh Siddha
1576506f1d07SSam Ravnborgconfig NUMA_EMU
1577506f1d07SSam Ravnborg	bool "NUMA emulation"
15781b7e03efSTejun Heo	depends on NUMA
15798f9ca475SIngo Molnar	---help---
1580506f1d07SSam Ravnborg	  Enable NUMA emulation. A flat machine will be split
1581506f1d07SSam Ravnborg	  into virtual nodes when booted with "numa=fake=N", where N is the
1582506f1d07SSam Ravnborg	  number of nodes. This is only useful for debugging.
1583506f1d07SSam Ravnborg
1584506f1d07SSam Ravnborgconfig NODES_SHIFT
1585d25e26b6SLinus Torvalds	int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP
158651591e31SDavid Rientjes	range 1 10
158751591e31SDavid Rientjes	default "10" if MAXSMP
1588506f1d07SSam Ravnborg	default "6" if X86_64
1589506f1d07SSam Ravnborg	default "3"
1590506f1d07SSam Ravnborg	depends on NEED_MULTIPLE_NODES
15918f9ca475SIngo Molnar	---help---
15921184dc2fSMike Travis	  Specify the maximum number of NUMA Nodes available on the target
1593692105b8SMatt LaPlante	  system.  Increases memory reserved to accommodate various tables.
1594506f1d07SSam Ravnborg
1595506f1d07SSam Ravnborgconfig ARCH_HAVE_MEMORY_PRESENT
15963c2362e6SHarvey Harrison	def_bool y
1597506f1d07SSam Ravnborg	depends on X86_32 && DISCONTIGMEM
1598506f1d07SSam Ravnborg
1599506f1d07SSam Ravnborgconfig ARCH_FLATMEM_ENABLE
1600506f1d07SSam Ravnborg	def_bool y
16013b16651fSTejun Heo	depends on X86_32 && !NUMA
1602506f1d07SSam Ravnborg
1603506f1d07SSam Ravnborgconfig ARCH_DISCONTIGMEM_ENABLE
1604506f1d07SSam Ravnborg	def_bool y
1605b263295dSChristoph Lameter	depends on NUMA && X86_32
1606506f1d07SSam Ravnborg
1607506f1d07SSam Ravnborgconfig ARCH_DISCONTIGMEM_DEFAULT
1608506f1d07SSam Ravnborg	def_bool y
1609b263295dSChristoph Lameter	depends on NUMA && X86_32
1610b263295dSChristoph Lameter
1611506f1d07SSam Ravnborgconfig ARCH_SPARSEMEM_ENABLE
1612506f1d07SSam Ravnborg	def_bool y
16136ea30386SKees Cook	depends on X86_64 || NUMA || X86_32 || X86_32_NON_STANDARD
1614506f1d07SSam Ravnborg	select SPARSEMEM_STATIC if X86_32
1615506f1d07SSam Ravnborg	select SPARSEMEM_VMEMMAP_ENABLE if X86_64
1616506f1d07SSam Ravnborg
16173b16651fSTejun Heoconfig ARCH_SPARSEMEM_DEFAULT
16183b16651fSTejun Heo	def_bool y
16193b16651fSTejun Heo	depends on X86_64
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
1642506f1d07SSam Ravnborgsource "mm/Kconfig"
1643506f1d07SSam Ravnborg
16447a67832cSDan Williamsconfig X86_PMEM_LEGACY_DEVICE
16457a67832cSDan Williams	bool
16467a67832cSDan Williams
1647ec776ef6SChristoph Hellwigconfig X86_PMEM_LEGACY
16487a67832cSDan Williams	tristate "Support non-standard NVDIMMs and ADR protected memory"
16499f53f9faSDan Williams	depends on PHYS_ADDR_T_64BIT
16509f53f9faSDan Williams	depends on BLK_DEV
16517a67832cSDan Williams	select X86_PMEM_LEGACY_DEVICE
16529f53f9faSDan Williams	select LIBNVDIMM
1653ec776ef6SChristoph Hellwig	help
1654ec776ef6SChristoph Hellwig	  Treat memory marked using the non-standard e820 type of 12 as used
1655ec776ef6SChristoph Hellwig	  by the Intel Sandy Bridge-EP reference BIOS as protected memory.
1656ec776ef6SChristoph Hellwig	  The kernel will offer these regions to the 'pmem' driver so
1657ec776ef6SChristoph Hellwig	  they can be used for persistent storage.
1658ec776ef6SChristoph Hellwig
1659ec776ef6SChristoph Hellwig	  Say Y if unsure.
1660ec776ef6SChristoph Hellwig
1661506f1d07SSam Ravnborgconfig HIGHPTE
1662506f1d07SSam Ravnborg	bool "Allocate 3rd-level pagetables from highmem"
16636fc108a0SJan Beulich	depends on HIGHMEM
16648f9ca475SIngo Molnar	---help---
1665506f1d07SSam Ravnborg	  The VM uses one page table entry for each page of physical memory.
1666506f1d07SSam Ravnborg	  For systems with a lot of RAM, this can be wasteful of precious
1667506f1d07SSam Ravnborg	  low memory.  Setting this option will put user-space page table
1668506f1d07SSam Ravnborg	  entries in high memory.
1669506f1d07SSam Ravnborg
16709f077871SJeremy Fitzhardingeconfig X86_CHECK_BIOS_CORRUPTION
16719f077871SJeremy Fitzhardinge	bool "Check for low memory corruption"
16728f9ca475SIngo Molnar	---help---
16739f077871SJeremy Fitzhardinge	  Periodically check for memory corruption in low memory, which
16749f077871SJeremy Fitzhardinge	  is suspected to be caused by BIOS.  Even when enabled in the
16759f077871SJeremy Fitzhardinge	  configuration, it is disabled at runtime.  Enable it by
16769f077871SJeremy Fitzhardinge	  setting "memory_corruption_check=1" on the kernel command
16779f077871SJeremy Fitzhardinge	  line.  By default it scans the low 64k of memory every 60
16789f077871SJeremy Fitzhardinge	  seconds; see the memory_corruption_check_size and
16799f077871SJeremy Fitzhardinge	  memory_corruption_check_period parameters in
16808c27ceffSMauro Carvalho Chehab	  Documentation/admin-guide/kernel-parameters.rst to adjust this.
16819f077871SJeremy Fitzhardinge
16829f077871SJeremy Fitzhardinge	  When enabled with the default parameters, this option has
16839f077871SJeremy Fitzhardinge	  almost no overhead, as it reserves a relatively small amount
16849f077871SJeremy Fitzhardinge	  of memory and scans it infrequently.  It both detects corruption
16859f077871SJeremy Fitzhardinge	  and prevents it from affecting the running system.
16869f077871SJeremy Fitzhardinge
16879f077871SJeremy Fitzhardinge	  It is, however, intended as a diagnostic tool; if repeatable
16889f077871SJeremy Fitzhardinge	  BIOS-originated corruption always affects the same memory,
16899f077871SJeremy Fitzhardinge	  you can use memmap= to prevent the kernel from using that
16909f077871SJeremy Fitzhardinge	  memory.
16919f077871SJeremy Fitzhardinge
1692c885df50SJeremy Fitzhardingeconfig X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK
1693c885df50SJeremy Fitzhardinge	bool "Set the default setting of memory_corruption_check"
1694c885df50SJeremy Fitzhardinge	depends on X86_CHECK_BIOS_CORRUPTION
1695c885df50SJeremy Fitzhardinge	default y
16968f9ca475SIngo Molnar	---help---
1697c885df50SJeremy Fitzhardinge	  Set whether the default state of memory_corruption_check is
1698c885df50SJeremy Fitzhardinge	  on or off.
1699c885df50SJeremy Fitzhardinge
17009ea77bdbSH. Peter Anvinconfig X86_RESERVE_LOW
1701d0cd7425SH. Peter Anvin	int "Amount of low memory, in kilobytes, to reserve for the BIOS"
1702d0cd7425SH. Peter Anvin	default 64
1703d0cd7425SH. Peter Anvin	range 4 640
17048f9ca475SIngo Molnar	---help---
1705d0cd7425SH. Peter Anvin	  Specify the amount of low memory to reserve for the BIOS.
1706fc381519SIngo Molnar
1707d0cd7425SH. Peter Anvin	  The first page contains BIOS data structures that the kernel
1708d0cd7425SH. Peter Anvin	  must not use, so that page must always be reserved.
1709fc381519SIngo Molnar
1710d0cd7425SH. Peter Anvin	  By default we reserve the first 64K of physical RAM, as a
1711d0cd7425SH. Peter Anvin	  number of BIOSes are known to corrupt that memory range
1712d0cd7425SH. Peter Anvin	  during events such as suspend/resume or monitor cable
1713d0cd7425SH. Peter Anvin	  insertion, so it must not be used by the kernel.
1714fc381519SIngo Molnar
1715d0cd7425SH. Peter Anvin	  You can set this to 4 if you are absolutely sure that you
1716d0cd7425SH. Peter Anvin	  trust the BIOS to get all its memory reservations and usages
1717d0cd7425SH. Peter Anvin	  right.  If you know your BIOS have problems beyond the
1718d0cd7425SH. Peter Anvin	  default 64K area, you can set this to 640 to avoid using the
1719d0cd7425SH. Peter Anvin	  entire low memory range.
1720d0cd7425SH. Peter Anvin
1721d0cd7425SH. Peter Anvin	  If you have doubts about the BIOS (e.g. suspend/resume does
1722d0cd7425SH. Peter Anvin	  not work or there's kernel crashes after certain hardware
1723d0cd7425SH. Peter Anvin	  hotplug events) then you might want to enable
1724d0cd7425SH. Peter Anvin	  X86_CHECK_BIOS_CORRUPTION=y to allow the kernel to check
1725d0cd7425SH. Peter Anvin	  typical corruption patterns.
1726d0cd7425SH. Peter Anvin
1727d0cd7425SH. Peter Anvin	  Leave this to the default value of 64 if you are unsure.
1728fc381519SIngo Molnar
1729506f1d07SSam Ravnborgconfig MATH_EMULATION
1730506f1d07SSam Ravnborg	bool
1731a5b9e5a2SAndy Lutomirski	depends on MODIFY_LDT_SYSCALL
1732506f1d07SSam Ravnborg	prompt "Math emulation" if X86_32
1733506f1d07SSam Ravnborg	---help---
1734506f1d07SSam Ravnborg	  Linux can emulate a math coprocessor (used for floating point
1735506f1d07SSam Ravnborg	  operations) if you don't have one. 486DX and Pentium processors have
1736506f1d07SSam Ravnborg	  a math coprocessor built in, 486SX and 386 do not, unless you added
1737506f1d07SSam Ravnborg	  a 487DX or 387, respectively. (The messages during boot time can
1738506f1d07SSam Ravnborg	  give you some hints here ["man dmesg"].) Everyone needs either a
1739506f1d07SSam Ravnborg	  coprocessor or this emulation.
1740506f1d07SSam Ravnborg
1741506f1d07SSam Ravnborg	  If you don't have a math coprocessor, you need to say Y here; if you
1742506f1d07SSam Ravnborg	  say Y here even though you have a coprocessor, the coprocessor will
1743506f1d07SSam Ravnborg	  be used nevertheless. (This behavior can be changed with the kernel
1744506f1d07SSam Ravnborg	  command line option "no387", which comes handy if your coprocessor
1745506f1d07SSam Ravnborg	  is broken. Try "man bootparam" or see the documentation of your boot
1746506f1d07SSam Ravnborg	  loader (lilo or loadlin) about how to pass options to the kernel at
1747506f1d07SSam Ravnborg	  boot time.) This means that it is a good idea to say Y here if you
1748506f1d07SSam Ravnborg	  intend to use this kernel on different machines.
1749506f1d07SSam Ravnborg
1750506f1d07SSam Ravnborg	  More information about the internals of the Linux math coprocessor
1751506f1d07SSam Ravnborg	  emulation can be found in <file:arch/x86/math-emu/README>.
1752506f1d07SSam Ravnborg
1753506f1d07SSam Ravnborg	  If you are not sure, say Y; apart from resulting in a 66 KB bigger
1754506f1d07SSam Ravnborg	  kernel, it won't hurt.
1755506f1d07SSam Ravnborg
1756506f1d07SSam Ravnborgconfig MTRR
17576fc108a0SJan Beulich	def_bool y
17586a108a14SDavid Rientjes	prompt "MTRR (Memory Type Range Register) support" if EXPERT
1759506f1d07SSam Ravnborg	---help---
1760506f1d07SSam Ravnborg	  On Intel P6 family processors (Pentium Pro, Pentium II and later)
1761506f1d07SSam Ravnborg	  the Memory Type Range Registers (MTRRs) may be used to control
1762506f1d07SSam Ravnborg	  processor access to memory ranges. This is most useful if you have
1763506f1d07SSam Ravnborg	  a video (VGA) card on a PCI or AGP bus. Enabling write-combining
1764506f1d07SSam Ravnborg	  allows bus write transfers to be combined into a larger transfer
1765506f1d07SSam Ravnborg	  before bursting over the PCI/AGP bus. This can increase performance
1766506f1d07SSam Ravnborg	  of image write operations 2.5 times or more. Saying Y here creates a
1767506f1d07SSam Ravnborg	  /proc/mtrr file which may be used to manipulate your processor's
1768506f1d07SSam Ravnborg	  MTRRs. Typically the X server should use this.
1769506f1d07SSam Ravnborg
1770506f1d07SSam Ravnborg	  This code has a reasonably generic interface so that similar
1771506f1d07SSam Ravnborg	  control registers on other processors can be easily supported
1772506f1d07SSam Ravnborg	  as well:
1773506f1d07SSam Ravnborg
1774506f1d07SSam Ravnborg	  The Cyrix 6x86, 6x86MX and M II processors have Address Range
1775506f1d07SSam Ravnborg	  Registers (ARRs) which provide a similar functionality to MTRRs. For
1776506f1d07SSam Ravnborg	  these, the ARRs are used to emulate the MTRRs.
1777506f1d07SSam Ravnborg	  The AMD K6-2 (stepping 8 and above) and K6-3 processors have two
1778506f1d07SSam Ravnborg	  MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing
1779506f1d07SSam Ravnborg	  write-combining. All of these processors are supported by this code
1780506f1d07SSam Ravnborg	  and it makes sense to say Y here if you have one of them.
1781506f1d07SSam Ravnborg
1782506f1d07SSam Ravnborg	  Saying Y here also fixes a problem with buggy SMP BIOSes which only
1783506f1d07SSam Ravnborg	  set the MTRRs for the boot CPU and not for the secondary CPUs. This
1784506f1d07SSam Ravnborg	  can lead to all sorts of problems, so it's good to say Y here.
1785506f1d07SSam Ravnborg
1786506f1d07SSam Ravnborg	  You can safely say Y even if your machine doesn't have MTRRs, you'll
1787506f1d07SSam Ravnborg	  just add about 9 KB to your kernel.
1788506f1d07SSam Ravnborg
17897225e751SRandy Dunlap	  See <file:Documentation/x86/mtrr.txt> for more information.
1790506f1d07SSam Ravnborg
179195ffa243SYinghai Luconfig MTRR_SANITIZER
17922ffb3501SYinghai Lu	def_bool y
179395ffa243SYinghai Lu	prompt "MTRR cleanup support"
179495ffa243SYinghai Lu	depends on MTRR
17958f9ca475SIngo Molnar	---help---
1796aba3728cSThomas Gleixner	  Convert MTRR layout from continuous to discrete, so X drivers can
1797aba3728cSThomas Gleixner	  add writeback entries.
179895ffa243SYinghai Lu
1799aba3728cSThomas Gleixner	  Can be disabled with disable_mtrr_cleanup on the kernel command line.
1800692105b8SMatt LaPlante	  The largest mtrr entry size for a continuous block can be set with
1801aba3728cSThomas Gleixner	  mtrr_chunk_size.
180295ffa243SYinghai Lu
18032ffb3501SYinghai Lu	  If unsure, say Y.
180495ffa243SYinghai Lu
180595ffa243SYinghai Luconfig MTRR_SANITIZER_ENABLE_DEFAULT
1806f5098d62SYinghai Lu	int "MTRR cleanup enable value (0-1)"
1807f5098d62SYinghai Lu	range 0 1
1808f5098d62SYinghai Lu	default "0"
180995ffa243SYinghai Lu	depends on MTRR_SANITIZER
18108f9ca475SIngo Molnar	---help---
1811f5098d62SYinghai Lu	  Enable mtrr cleanup default value
181295ffa243SYinghai Lu
181312031a62SYinghai Luconfig MTRR_SANITIZER_SPARE_REG_NR_DEFAULT
181412031a62SYinghai Lu	int "MTRR cleanup spare reg num (0-7)"
181512031a62SYinghai Lu	range 0 7
181612031a62SYinghai Lu	default "1"
181712031a62SYinghai Lu	depends on MTRR_SANITIZER
18188f9ca475SIngo Molnar	---help---
181912031a62SYinghai Lu	  mtrr cleanup spare entries default, it can be changed via
1820aba3728cSThomas Gleixner	  mtrr_spare_reg_nr=N on the kernel command line.
182112031a62SYinghai Lu
18222e5d9c85Svenkatesh.pallipadi@intel.comconfig X86_PAT
18236fc108a0SJan Beulich	def_bool y
18246a108a14SDavid Rientjes	prompt "x86 PAT support" if EXPERT
18252a8a2719SIngo Molnar	depends on MTRR
18268f9ca475SIngo Molnar	---help---
18272e5d9c85Svenkatesh.pallipadi@intel.com	  Use PAT attributes to setup page level cache control.
1828042b78e4SVenki Pallipadi
18292e5d9c85Svenkatesh.pallipadi@intel.com	  PATs are the modern equivalents of MTRRs and are much more
18302e5d9c85Svenkatesh.pallipadi@intel.com	  flexible than MTRRs.
18312e5d9c85Svenkatesh.pallipadi@intel.com
18322e5d9c85Svenkatesh.pallipadi@intel.com	  Say N here if you see bootup problems (boot crash, boot hang,
1833042b78e4SVenki Pallipadi	  spontaneous reboots) or a non-working video driver.
18342e5d9c85Svenkatesh.pallipadi@intel.com
18352e5d9c85Svenkatesh.pallipadi@intel.com	  If unsure, say Y.
18362e5d9c85Svenkatesh.pallipadi@intel.com
183746cf98cdSVenkatesh Pallipadiconfig ARCH_USES_PG_UNCACHED
183846cf98cdSVenkatesh Pallipadi	def_bool y
183946cf98cdSVenkatesh Pallipadi	depends on X86_PAT
184046cf98cdSVenkatesh Pallipadi
1841628c6246SH. Peter Anvinconfig ARCH_RANDOM
1842628c6246SH. Peter Anvin	def_bool y
1843628c6246SH. Peter Anvin	prompt "x86 architectural random number generator" if EXPERT
1844628c6246SH. Peter Anvin	---help---
1845628c6246SH. Peter Anvin	  Enable the x86 architectural RDRAND instruction
1846628c6246SH. Peter Anvin	  (Intel Bull Mountain technology) to generate random numbers.
1847628c6246SH. Peter Anvin	  If supported, this is a high bandwidth, cryptographically
1848628c6246SH. Peter Anvin	  secure hardware random number generator.
1849628c6246SH. Peter Anvin
185051ae4a2dSH. Peter Anvinconfig X86_SMAP
185151ae4a2dSH. Peter Anvin	def_bool y
185251ae4a2dSH. Peter Anvin	prompt "Supervisor Mode Access Prevention" if EXPERT
185351ae4a2dSH. Peter Anvin	---help---
185451ae4a2dSH. Peter Anvin	  Supervisor Mode Access Prevention (SMAP) is a security
185551ae4a2dSH. Peter Anvin	  feature in newer Intel processors.  There is a small
185651ae4a2dSH. Peter Anvin	  performance cost if this enabled and turned on; there is
185751ae4a2dSH. Peter Anvin	  also a small increase in the kernel size if this is enabled.
185851ae4a2dSH. Peter Anvin
185951ae4a2dSH. Peter Anvin	  If unsure, say Y.
186051ae4a2dSH. Peter Anvin
1861aa35f896SRicardo Nericonfig X86_INTEL_UMIP
1862796ebc81SRicardo Neri	def_bool y
1863aa35f896SRicardo Neri	depends on CPU_SUP_INTEL
1864aa35f896SRicardo Neri	prompt "Intel User Mode Instruction Prevention" if EXPERT
1865aa35f896SRicardo Neri	---help---
1866aa35f896SRicardo Neri	  The User Mode Instruction Prevention (UMIP) is a security
1867aa35f896SRicardo Neri	  feature in newer Intel processors. If enabled, a general
1868796ebc81SRicardo Neri	  protection fault is issued if the SGDT, SLDT, SIDT, SMSW
1869796ebc81SRicardo Neri	  or STR instructions are executed in user mode. These instructions
1870796ebc81SRicardo Neri	  unnecessarily expose information about the hardware state.
1871796ebc81SRicardo Neri
1872796ebc81SRicardo Neri	  The vast majority of applications do not use these instructions.
1873796ebc81SRicardo Neri	  For the very few that do, software emulation is provided in
1874796ebc81SRicardo Neri	  specific cases in protected and virtual-8086 modes. Emulated
1875796ebc81SRicardo Neri	  results are dummy.
1876aa35f896SRicardo Neri
187772e9b5feSDave Hansenconfig X86_INTEL_MPX
187872e9b5feSDave Hansen	prompt "Intel MPX (Memory Protection Extensions)"
187972e9b5feSDave Hansen	def_bool n
1880df3735c5SRik van Riel	# Note: only available in 64-bit mode due to VMA flags shortage
1881df3735c5SRik van Riel	depends on CPU_SUP_INTEL && X86_64
1882df3735c5SRik van Riel	select ARCH_USES_HIGH_VMA_FLAGS
188372e9b5feSDave Hansen	---help---
188472e9b5feSDave Hansen	  MPX provides hardware features that can be used in
188572e9b5feSDave Hansen	  conjunction with compiler-instrumented code to check
188672e9b5feSDave Hansen	  memory references.  It is designed to detect buffer
188772e9b5feSDave Hansen	  overflow or underflow bugs.
188872e9b5feSDave Hansen
188972e9b5feSDave Hansen	  This option enables running applications which are
189072e9b5feSDave Hansen	  instrumented or otherwise use MPX.  It does not use MPX
189172e9b5feSDave Hansen	  itself inside the kernel or to protect the kernel
189272e9b5feSDave Hansen	  against bad memory references.
189372e9b5feSDave Hansen
189472e9b5feSDave Hansen	  Enabling this option will make the kernel larger:
189572e9b5feSDave Hansen	  ~8k of kernel text and 36 bytes of data on a 64-bit
189672e9b5feSDave Hansen	  defconfig.  It adds a long to the 'mm_struct' which
189772e9b5feSDave Hansen	  will increase the kernel memory overhead of each
189872e9b5feSDave Hansen	  process and adds some branches to paths used during
189972e9b5feSDave Hansen	  exec() and munmap().
190072e9b5feSDave Hansen
190172e9b5feSDave Hansen	  For details, see Documentation/x86/intel_mpx.txt
190272e9b5feSDave Hansen
190372e9b5feSDave Hansen	  If unsure, say N.
190472e9b5feSDave Hansen
190535e97790SDave Hansenconfig X86_INTEL_MEMORY_PROTECTION_KEYS
1906284244a9SDave Hansen	prompt "Intel Memory Protection Keys"
190735e97790SDave Hansen	def_bool y
1908284244a9SDave Hansen	# Note: only available in 64-bit mode
190935e97790SDave Hansen	depends on CPU_SUP_INTEL && X86_64
191052c8e601SIngo Molnar	select ARCH_USES_HIGH_VMA_FLAGS
191152c8e601SIngo Molnar	select ARCH_HAS_PKEYS
1912284244a9SDave Hansen	---help---
1913284244a9SDave Hansen	  Memory Protection Keys provides a mechanism for enforcing
1914284244a9SDave Hansen	  page-based protections, but without requiring modification of the
1915284244a9SDave Hansen	  page tables when an application changes protection domains.
1916284244a9SDave Hansen
1917284244a9SDave Hansen	  For details, see Documentation/x86/protection-keys.txt
1918284244a9SDave Hansen
1919284244a9SDave Hansen	  If unsure, say y.
192035e97790SDave Hansen
1921506f1d07SSam Ravnborgconfig EFI
19229ba16087SJan Beulich	bool "EFI runtime service support"
19235b83683fSHuang, Ying	depends on ACPI
1924f6ce5002SSergey Vlasov	select UCS2_STRING
1925022ee6c5SArd Biesheuvel	select EFI_RUNTIME_WRAPPERS
1926506f1d07SSam Ravnborg	---help---
19278b2cb7a8SHuang, Ying	  This enables the kernel to use EFI runtime services that are
1928506f1d07SSam Ravnborg	  available (such as the EFI variable services).
1929506f1d07SSam Ravnborg
19308b2cb7a8SHuang, Ying	  This option is only useful on systems that have EFI firmware.
19318b2cb7a8SHuang, Ying	  In addition, you should use the latest ELILO loader available
19328b2cb7a8SHuang, Ying	  at <http://elilo.sourceforge.net> in order to take advantage
19338b2cb7a8SHuang, Ying	  of EFI runtime services. However, even with this option, the
19348b2cb7a8SHuang, Ying	  resultant kernel should continue to boot on existing non-EFI
19358b2cb7a8SHuang, Ying	  platforms.
1936506f1d07SSam Ravnborg
1937291f3632SMatt Flemingconfig EFI_STUB
1938291f3632SMatt Fleming       bool "EFI stub support"
1939b16d8c23SMatt Fleming       depends on EFI && !X86_USE_3DNOW
19407b2a583aSMatt Fleming       select RELOCATABLE
1941291f3632SMatt Fleming       ---help---
1942291f3632SMatt Fleming          This kernel feature allows a bzImage to be loaded directly
1943291f3632SMatt Fleming	  by EFI firmware without the use of a bootloader.
1944291f3632SMatt Fleming
19454172fe2fSRoy Franz	  See Documentation/efi-stub.txt for more information.
19460c759662SMatt Fleming
19477d453eeeSMatt Flemingconfig EFI_MIXED
19487d453eeeSMatt Fleming	bool "EFI mixed-mode support"
19497d453eeeSMatt Fleming	depends on EFI_STUB && X86_64
19507d453eeeSMatt Fleming	---help---
19517d453eeeSMatt Fleming	   Enabling this feature allows a 64-bit kernel to be booted
19527d453eeeSMatt Fleming	   on a 32-bit firmware, provided that your CPU supports 64-bit
19537d453eeeSMatt Fleming	   mode.
19547d453eeeSMatt Fleming
19557d453eeeSMatt Fleming	   Note that it is not possible to boot a mixed-mode enabled
19567d453eeeSMatt Fleming	   kernel via the EFI boot stub - a bootloader that supports
19577d453eeeSMatt Fleming	   the EFI handover protocol must be used.
19587d453eeeSMatt Fleming
19597d453eeeSMatt Fleming	   If unsure, say N.
19607d453eeeSMatt Fleming
1961506f1d07SSam Ravnborgconfig SECCOMP
19623c2362e6SHarvey Harrison	def_bool y
19633c2362e6SHarvey Harrison	prompt "Enable seccomp to safely compute untrusted bytecode"
19648f9ca475SIngo Molnar	---help---
1965506f1d07SSam Ravnborg	  This kernel feature is useful for number crunching applications
1966506f1d07SSam Ravnborg	  that may need to compute untrusted bytecode during their
1967506f1d07SSam Ravnborg	  execution. By using pipes or other transports made available to
1968506f1d07SSam Ravnborg	  the process as file descriptors supporting the read/write
1969506f1d07SSam Ravnborg	  syscalls, it's possible to isolate those applications in
1970506f1d07SSam Ravnborg	  their own address space using seccomp. Once seccomp is
19719c0bbee8SAlexey Dobriyan	  enabled via prctl(PR_SET_SECCOMP), it cannot be disabled
1972506f1d07SSam Ravnborg	  and the task is only allowed to execute a few safe syscalls
1973506f1d07SSam Ravnborg	  defined by each seccomp mode.
1974506f1d07SSam Ravnborg
1975506f1d07SSam Ravnborg	  If unsure, say Y. Only embedded should say N here.
1976506f1d07SSam Ravnborg
1977506f1d07SSam Ravnborgsource kernel/Kconfig.hz
1978506f1d07SSam Ravnborg
1979506f1d07SSam Ravnborgconfig KEXEC
1980506f1d07SSam Ravnborg	bool "kexec system call"
19812965faa5SDave Young	select KEXEC_CORE
19828f9ca475SIngo Molnar	---help---
1983506f1d07SSam Ravnborg	  kexec is a system call that implements the ability to shutdown your
1984506f1d07SSam Ravnborg	  current kernel, and to start another kernel.  It is like a reboot
1985506f1d07SSam Ravnborg	  but it is independent of the system firmware.   And like a reboot
1986506f1d07SSam Ravnborg	  you can start any kernel with it, not just Linux.
1987506f1d07SSam Ravnborg
1988506f1d07SSam Ravnborg	  The name comes from the similarity to the exec system call.
1989506f1d07SSam Ravnborg
1990506f1d07SSam Ravnborg	  It is an ongoing process to be certain the hardware in a machine
1991506f1d07SSam Ravnborg	  is properly shutdown, so do not be surprised if this code does not
1992bf220695SGeert Uytterhoeven	  initially work for you.  As of this writing the exact hardware
1993bf220695SGeert Uytterhoeven	  interface is strongly in flux, so no good recommendation can be
1994bf220695SGeert Uytterhoeven	  made.
1995506f1d07SSam Ravnborg
199674ca317cSVivek Goyalconfig KEXEC_FILE
199774ca317cSVivek Goyal	bool "kexec file based system call"
19982965faa5SDave Young	select KEXEC_CORE
199974ca317cSVivek Goyal	select BUILD_BIN2C
200074ca317cSVivek Goyal	depends on X86_64
200174ca317cSVivek Goyal	depends on CRYPTO=y
200274ca317cSVivek Goyal	depends on CRYPTO_SHA256=y
200374ca317cSVivek Goyal	---help---
200474ca317cSVivek Goyal	  This is new version of kexec system call. This system call is
200574ca317cSVivek Goyal	  file based and takes file descriptors as system call argument
200674ca317cSVivek Goyal	  for kernel and initramfs as opposed to list of segments as
200774ca317cSVivek Goyal	  accepted by previous system call.
200874ca317cSVivek Goyal
2009b799a09fSAKASHI Takahiroconfig ARCH_HAS_KEXEC_PURGATORY
2010b799a09fSAKASHI Takahiro	def_bool KEXEC_FILE
2011b799a09fSAKASHI Takahiro
20128e7d8381SVivek Goyalconfig KEXEC_VERIFY_SIG
20138e7d8381SVivek Goyal	bool "Verify kernel signature during kexec_file_load() syscall"
201474ca317cSVivek Goyal	depends on KEXEC_FILE
20158e7d8381SVivek Goyal	---help---
20168e7d8381SVivek Goyal	  This option makes kernel signature verification mandatory for
2017d8eb8940SBorislav Petkov	  the kexec_file_load() syscall.
20188e7d8381SVivek Goyal
2019d8eb8940SBorislav Petkov	  In addition to that option, you need to enable signature
2020d8eb8940SBorislav Petkov	  verification for the corresponding kernel image type being
2021d8eb8940SBorislav Petkov	  loaded in order for this to work.
20228e7d8381SVivek Goyal
20238e7d8381SVivek Goyalconfig KEXEC_BZIMAGE_VERIFY_SIG
20248e7d8381SVivek Goyal	bool "Enable bzImage signature verification support"
20258e7d8381SVivek Goyal	depends on KEXEC_VERIFY_SIG
20268e7d8381SVivek Goyal	depends on SIGNED_PE_FILE_VERIFICATION
20278e7d8381SVivek Goyal	select SYSTEM_TRUSTED_KEYRING
20288e7d8381SVivek Goyal	---help---
20298e7d8381SVivek Goyal	  Enable bzImage signature verification support.
20308e7d8381SVivek Goyal
2031506f1d07SSam Ravnborgconfig CRASH_DUMP
203204b69447SPavel Machek	bool "kernel crash dumps"
2033506f1d07SSam Ravnborg	depends on X86_64 || (X86_32 && HIGHMEM)
20348f9ca475SIngo Molnar	---help---
2035506f1d07SSam Ravnborg	  Generate crash dump after being started by kexec.
2036506f1d07SSam Ravnborg	  This should be normally only set in special crash dump kernels
2037506f1d07SSam Ravnborg	  which are loaded in the main kernel with kexec-tools into
2038506f1d07SSam Ravnborg	  a specially reserved region and then later executed after
2039506f1d07SSam Ravnborg	  a crash by kdump/kexec. The crash dump kernel must be compiled
2040506f1d07SSam Ravnborg	  to a memory address not used by the main kernel or BIOS using
2041506f1d07SSam Ravnborg	  PHYSICAL_START, or it must be built as a relocatable image
2042506f1d07SSam Ravnborg	  (CONFIG_RELOCATABLE=y).
2043506f1d07SSam Ravnborg	  For more details see Documentation/kdump/kdump.txt
2044506f1d07SSam Ravnborg
20453ab83521SHuang Yingconfig KEXEC_JUMP
20466ea30386SKees Cook	bool "kexec jump"
2047fee7b0d8SHuang Ying	depends on KEXEC && HIBERNATION
20488f9ca475SIngo Molnar	---help---
204989081d17SHuang Ying	  Jump between original kernel and kexeced kernel and invoke
205089081d17SHuang Ying	  code in physical address mode via KEXEC
20513ab83521SHuang Ying
2052506f1d07SSam Ravnborgconfig PHYSICAL_START
20536a108a14SDavid Rientjes	hex "Physical address where the kernel is loaded" if (EXPERT || CRASH_DUMP)
2054ceefccc9SH. Peter Anvin	default "0x1000000"
20558f9ca475SIngo Molnar	---help---
2056506f1d07SSam Ravnborg	  This gives the physical address where the kernel is loaded.
2057506f1d07SSam Ravnborg
2058506f1d07SSam Ravnborg	  If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then
2059506f1d07SSam Ravnborg	  bzImage will decompress itself to above physical address and
2060506f1d07SSam Ravnborg	  run from there. Otherwise, bzImage will run from the address where
2061506f1d07SSam Ravnborg	  it has been loaded by the boot loader and will ignore above physical
2062506f1d07SSam Ravnborg	  address.
2063506f1d07SSam Ravnborg
2064506f1d07SSam Ravnborg	  In normal kdump cases one does not have to set/change this option
2065506f1d07SSam Ravnborg	  as now bzImage can be compiled as a completely relocatable image
2066506f1d07SSam Ravnborg	  (CONFIG_RELOCATABLE=y) and be used to load and run from a different
2067506f1d07SSam Ravnborg	  address. This option is mainly useful for the folks who don't want
2068506f1d07SSam Ravnborg	  to use a bzImage for capturing the crash dump and want to use a
2069506f1d07SSam Ravnborg	  vmlinux instead. vmlinux is not relocatable hence a kernel needs
2070506f1d07SSam Ravnborg	  to be specifically compiled to run from a specific memory area
2071506f1d07SSam Ravnborg	  (normally a reserved region) and this option comes handy.
2072506f1d07SSam Ravnborg
2073ceefccc9SH. Peter Anvin	  So if you are using bzImage for capturing the crash dump,
2074ceefccc9SH. Peter Anvin	  leave the value here unchanged to 0x1000000 and set
2075ceefccc9SH. Peter Anvin	  CONFIG_RELOCATABLE=y.  Otherwise if you plan to use vmlinux
2076ceefccc9SH. Peter Anvin	  for capturing the crash dump change this value to start of
2077ceefccc9SH. Peter Anvin	  the reserved region.  In other words, it can be set based on
2078ceefccc9SH. Peter Anvin	  the "X" value as specified in the "crashkernel=YM@XM"
2079ceefccc9SH. Peter Anvin	  command line boot parameter passed to the panic-ed
2080ceefccc9SH. Peter Anvin	  kernel. Please take a look at Documentation/kdump/kdump.txt
2081ceefccc9SH. Peter Anvin	  for more details about crash dumps.
2082506f1d07SSam Ravnborg
2083506f1d07SSam Ravnborg	  Usage of bzImage for capturing the crash dump is recommended as
2084506f1d07SSam Ravnborg	  one does not have to build two kernels. Same kernel can be used
2085506f1d07SSam Ravnborg	  as production kernel and capture kernel. Above option should have
2086506f1d07SSam Ravnborg	  gone away after relocatable bzImage support is introduced. But it
2087506f1d07SSam Ravnborg	  is present because there are users out there who continue to use
2088506f1d07SSam Ravnborg	  vmlinux for dump capture. This option should go away down the
2089506f1d07SSam Ravnborg	  line.
2090506f1d07SSam Ravnborg
2091506f1d07SSam Ravnborg	  Don't change this unless you know what you are doing.
2092506f1d07SSam Ravnborg
2093506f1d07SSam Ravnborgconfig RELOCATABLE
209426717808SH. Peter Anvin	bool "Build a relocatable kernel"
209526717808SH. Peter Anvin	default y
20968f9ca475SIngo Molnar	---help---
2097506f1d07SSam Ravnborg	  This builds a kernel image that retains relocation information
2098506f1d07SSam Ravnborg	  so it can be loaded someplace besides the default 1MB.
2099506f1d07SSam Ravnborg	  The relocations tend to make the kernel binary about 10% larger,
2100506f1d07SSam Ravnborg	  but are discarded at runtime.
2101506f1d07SSam Ravnborg
2102506f1d07SSam Ravnborg	  One use is for the kexec on panic case where the recovery kernel
2103506f1d07SSam Ravnborg	  must live at a different physical address than the primary
2104506f1d07SSam Ravnborg	  kernel.
2105506f1d07SSam Ravnborg
2106506f1d07SSam Ravnborg	  Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address
2107506f1d07SSam Ravnborg	  it has been loaded at and the compile time physical address
21088ab3820fSKees Cook	  (CONFIG_PHYSICAL_START) is used as the minimum location.
2109506f1d07SSam Ravnborg
21108ab3820fSKees Cookconfig RANDOMIZE_BASE
2111e8581e3dSBaoquan He	bool "Randomize the address of the kernel image (KASLR)"
21128ab3820fSKees Cook	depends on RELOCATABLE
21136807c846SIngo Molnar	default y
21148ab3820fSKees Cook	---help---
2115e8581e3dSBaoquan He	  In support of Kernel Address Space Layout Randomization (KASLR),
2116e8581e3dSBaoquan He	  this randomizes the physical address at which the kernel image
2117e8581e3dSBaoquan He	  is decompressed and the virtual address where the kernel
2118e8581e3dSBaoquan He	  image is mapped, as a security feature that deters exploit
2119e8581e3dSBaoquan He	  attempts relying on knowledge of the location of kernel
2120e8581e3dSBaoquan He	  code internals.
2121e8581e3dSBaoquan He
2122ed9f007eSKees Cook	  On 64-bit, the kernel physical and virtual addresses are
2123ed9f007eSKees Cook	  randomized separately. The physical address will be anywhere
2124ed9f007eSKees Cook	  between 16MB and the top of physical memory (up to 64TB). The
2125ed9f007eSKees Cook	  virtual address will be randomized from 16MB up to 1GB (9 bits
2126ed9f007eSKees Cook	  of entropy). Note that this also reduces the memory space
2127ed9f007eSKees Cook	  available to kernel modules from 1.5GB to 1GB.
2128ed9f007eSKees Cook
2129ed9f007eSKees Cook	  On 32-bit, the kernel physical and virtual addresses are
2130ed9f007eSKees Cook	  randomized together. They will be randomized from 16MB up to
2131ed9f007eSKees Cook	  512MB (8 bits of entropy).
21328ab3820fSKees Cook
2133a653f356SKees Cook	  Entropy is generated using the RDRAND instruction if it is
2134e8581e3dSBaoquan He	  supported. If RDTSC is supported, its value is mixed into
2135e8581e3dSBaoquan He	  the entropy pool as well. If neither RDRAND nor RDTSC are
2136ed9f007eSKees Cook	  supported, then entropy is read from the i8254 timer. The
2137ed9f007eSKees Cook	  usable entropy is limited by the kernel being built using
2138ed9f007eSKees Cook	  2GB addressing, and that PHYSICAL_ALIGN must be at a
2139ed9f007eSKees Cook	  minimum of 2MB. As a result, only 10 bits of entropy are
2140ed9f007eSKees Cook	  theoretically possible, but the implementations are further
2141ed9f007eSKees Cook	  limited due to memory layouts.
2142e8581e3dSBaoquan He
21436807c846SIngo Molnar	  If unsure, say Y.
2144da2b6fb9SKees Cook
21458ab3820fSKees Cook# Relocation on x86 needs some additional build support
2146845adf72SH. Peter Anvinconfig X86_NEED_RELOCS
2147845adf72SH. Peter Anvin	def_bool y
21488ab3820fSKees Cook	depends on RANDOMIZE_BASE || (X86_32 && RELOCATABLE)
2149845adf72SH. Peter Anvin
2150506f1d07SSam Ravnborgconfig PHYSICAL_ALIGN
2151a0215061SKees Cook	hex "Alignment value to which kernel should be aligned"
21528ab3820fSKees Cook	default "0x200000"
2153a0215061SKees Cook	range 0x2000 0x1000000 if X86_32
2154a0215061SKees Cook	range 0x200000 0x1000000 if X86_64
21558f9ca475SIngo Molnar	---help---
2156506f1d07SSam Ravnborg	  This value puts the alignment restrictions on physical address
2157506f1d07SSam Ravnborg	  where kernel is loaded and run from. Kernel is compiled for an
2158506f1d07SSam Ravnborg	  address which meets above alignment restriction.
2159506f1d07SSam Ravnborg
2160506f1d07SSam Ravnborg	  If bootloader loads the kernel at a non-aligned address and
2161506f1d07SSam Ravnborg	  CONFIG_RELOCATABLE is set, kernel will move itself to nearest
2162506f1d07SSam Ravnborg	  address aligned to above value and run from there.
2163506f1d07SSam Ravnborg
2164506f1d07SSam Ravnborg	  If bootloader loads the kernel at a non-aligned address and
2165506f1d07SSam Ravnborg	  CONFIG_RELOCATABLE is not set, kernel will ignore the run time
2166506f1d07SSam Ravnborg	  load address and decompress itself to the address it has been
2167506f1d07SSam Ravnborg	  compiled for and run from there. The address for which kernel is
2168506f1d07SSam Ravnborg	  compiled already meets above alignment restrictions. Hence the
2169506f1d07SSam Ravnborg	  end result is that kernel runs from a physical address meeting
2170506f1d07SSam Ravnborg	  above alignment restrictions.
2171506f1d07SSam Ravnborg
2172a0215061SKees Cook	  On 32-bit this value must be a multiple of 0x2000. On 64-bit
2173a0215061SKees Cook	  this value must be a multiple of 0x200000.
2174a0215061SKees Cook
2175506f1d07SSam Ravnborg	  Don't change this unless you know what you are doing.
2176506f1d07SSam Ravnborg
2177eedb92abSKirill A. Shutemovconfig DYNAMIC_MEMORY_LAYOUT
2178eedb92abSKirill A. Shutemov	bool
2179eedb92abSKirill A. Shutemov	---help---
2180eedb92abSKirill A. Shutemov	  This option makes base addresses of vmalloc and vmemmap as well as
2181eedb92abSKirill A. Shutemov	  __PAGE_OFFSET movable during boot.
2182eedb92abSKirill A. Shutemov
21830483e1faSThomas Garnierconfig RANDOMIZE_MEMORY
21840483e1faSThomas Garnier	bool "Randomize the kernel memory sections"
21850483e1faSThomas Garnier	depends on X86_64
21860483e1faSThomas Garnier	depends on RANDOMIZE_BASE
2187eedb92abSKirill A. Shutemov	select DYNAMIC_MEMORY_LAYOUT
21880483e1faSThomas Garnier	default RANDOMIZE_BASE
21890483e1faSThomas Garnier	---help---
21900483e1faSThomas Garnier	   Randomizes the base virtual address of kernel memory sections
21910483e1faSThomas Garnier	   (physical memory mapping, vmalloc & vmemmap). This security feature
21920483e1faSThomas Garnier	   makes exploits relying on predictable memory locations less reliable.
21930483e1faSThomas Garnier
21940483e1faSThomas Garnier	   The order of allocations remains unchanged. Entropy is generated in
21950483e1faSThomas Garnier	   the same way as RANDOMIZE_BASE. Current implementation in the optimal
21960483e1faSThomas Garnier	   configuration have in average 30,000 different possible virtual
21970483e1faSThomas Garnier	   addresses for each memory section.
21980483e1faSThomas Garnier
21996807c846SIngo Molnar	   If unsure, say Y.
22000483e1faSThomas Garnier
220190397a41SThomas Garnierconfig RANDOMIZE_MEMORY_PHYSICAL_PADDING
220290397a41SThomas Garnier	hex "Physical memory mapping padding" if EXPERT
220390397a41SThomas Garnier	depends on RANDOMIZE_MEMORY
220490397a41SThomas Garnier	default "0xa" if MEMORY_HOTPLUG
220590397a41SThomas Garnier	default "0x0"
220690397a41SThomas Garnier	range 0x1 0x40 if MEMORY_HOTPLUG
220790397a41SThomas Garnier	range 0x0 0x40
220890397a41SThomas Garnier	---help---
220990397a41SThomas Garnier	   Define the padding in terabytes added to the existing physical
221090397a41SThomas Garnier	   memory size during kernel memory randomization. It is useful
221190397a41SThomas Garnier	   for memory hotplug support but reduces the entropy available for
221290397a41SThomas Garnier	   address randomization.
221390397a41SThomas Garnier
221490397a41SThomas Garnier	   If unsure, leave at the default value.
221590397a41SThomas Garnier
2216506f1d07SSam Ravnborgconfig HOTPLUG_CPU
22177c13e6a3SDimitri Sivanich	bool "Support for hot-pluggable CPUs"
221840b31360SStephen Rothwell	depends on SMP
2219506f1d07SSam Ravnborg	---help---
22207c13e6a3SDimitri Sivanich	  Say Y here to allow turning CPUs off and on. CPUs can be
22217c13e6a3SDimitri Sivanich	  controlled through /sys/devices/system/cpu.
22227c13e6a3SDimitri Sivanich	  ( Note: power management support will enable this option
22237c13e6a3SDimitri Sivanich	    automatically on SMP systems. )
22247c13e6a3SDimitri Sivanich	  Say N if you want to disable CPU hotplug.
2225506f1d07SSam Ravnborg
222680aa1dffSFenghua Yuconfig BOOTPARAM_HOTPLUG_CPU0
222780aa1dffSFenghua Yu	bool "Set default setting of cpu0_hotpluggable"
222880aa1dffSFenghua Yu	default n
22292c922cd0SKees Cook	depends on HOTPLUG_CPU
223080aa1dffSFenghua Yu	---help---
223180aa1dffSFenghua Yu	  Set whether default state of cpu0_hotpluggable is on or off.
223280aa1dffSFenghua Yu
223380aa1dffSFenghua Yu	  Say Y here to enable CPU0 hotplug by default. If this switch
223480aa1dffSFenghua Yu	  is turned on, there is no need to give cpu0_hotplug kernel
223580aa1dffSFenghua Yu	  parameter and the CPU0 hotplug feature is enabled by default.
223680aa1dffSFenghua Yu
223780aa1dffSFenghua Yu	  Please note: there are two known CPU0 dependencies if you want
223880aa1dffSFenghua Yu	  to enable the CPU0 hotplug feature either by this switch or by
223980aa1dffSFenghua Yu	  cpu0_hotplug kernel parameter.
224080aa1dffSFenghua Yu
224180aa1dffSFenghua Yu	  First, resume from hibernate or suspend always starts from CPU0.
224280aa1dffSFenghua Yu	  So hibernate and suspend are prevented if CPU0 is offline.
224380aa1dffSFenghua Yu
224480aa1dffSFenghua Yu	  Second dependency is PIC interrupts always go to CPU0. CPU0 can not
224580aa1dffSFenghua Yu	  offline if any interrupt can not migrate out of CPU0. There may
224680aa1dffSFenghua Yu	  be other CPU0 dependencies.
224780aa1dffSFenghua Yu
224880aa1dffSFenghua Yu	  Please make sure the dependencies are under your control before
224980aa1dffSFenghua Yu	  you enable this feature.
225080aa1dffSFenghua Yu
225180aa1dffSFenghua Yu	  Say N if you don't want to enable CPU0 hotplug feature by default.
225280aa1dffSFenghua Yu	  You still can enable the CPU0 hotplug feature at boot by kernel
225380aa1dffSFenghua Yu	  parameter cpu0_hotplug.
225480aa1dffSFenghua Yu
2255a71c8bc5SFenghua Yuconfig DEBUG_HOTPLUG_CPU0
2256a71c8bc5SFenghua Yu	def_bool n
2257a71c8bc5SFenghua Yu	prompt "Debug CPU0 hotplug"
22582c922cd0SKees Cook	depends on HOTPLUG_CPU
2259a71c8bc5SFenghua Yu	---help---
2260a71c8bc5SFenghua Yu	  Enabling this option offlines CPU0 (if CPU0 can be offlined) as
2261a71c8bc5SFenghua Yu	  soon as possible and boots up userspace with CPU0 offlined. User
2262a71c8bc5SFenghua Yu	  can online CPU0 back after boot time.
2263a71c8bc5SFenghua Yu
2264a71c8bc5SFenghua Yu	  To debug CPU0 hotplug, you need to enable CPU0 offline/online
2265a71c8bc5SFenghua Yu	  feature by either turning on CONFIG_BOOTPARAM_HOTPLUG_CPU0 during
2266a71c8bc5SFenghua Yu	  compilation or giving cpu0_hotplug kernel parameter at boot.
2267a71c8bc5SFenghua Yu
2268a71c8bc5SFenghua Yu	  If unsure, say N.
2269a71c8bc5SFenghua Yu
2270506f1d07SSam Ravnborgconfig COMPAT_VDSO
2271b0b49f26SAndy Lutomirski	def_bool n
2272b0b49f26SAndy Lutomirski	prompt "Disable the 32-bit vDSO (needed for glibc 2.3.3)"
2273953fee1dSIngo Molnar	depends on COMPAT_32
22748f9ca475SIngo Molnar	---help---
2275b0b49f26SAndy Lutomirski	  Certain buggy versions of glibc will crash if they are
2276b0b49f26SAndy Lutomirski	  presented with a 32-bit vDSO that is not mapped at the address
2277b0b49f26SAndy Lutomirski	  indicated in its segment table.
2278e84446deSRandy Dunlap
2279b0b49f26SAndy Lutomirski	  The bug was introduced by f866314b89d56845f55e6f365e18b31ec978ec3a
2280b0b49f26SAndy Lutomirski	  and fixed by 3b3ddb4f7db98ec9e912ccdf54d35df4aa30e04a and
2281b0b49f26SAndy Lutomirski	  49ad572a70b8aeb91e57483a11dd1b77e31c4468.  Glibc 2.3.3 is
2282b0b49f26SAndy Lutomirski	  the only released version with the bug, but OpenSUSE 9
2283b0b49f26SAndy Lutomirski	  contains a buggy "glibc 2.3.2".
2284506f1d07SSam Ravnborg
2285b0b49f26SAndy Lutomirski	  The symptom of the bug is that everything crashes on startup, saying:
2286b0b49f26SAndy Lutomirski	  dl_main: Assertion `(void *) ph->p_vaddr == _rtld_local._dl_sysinfo_dso' failed!
2287b0b49f26SAndy Lutomirski
2288b0b49f26SAndy Lutomirski	  Saying Y here changes the default value of the vdso32 boot
2289b0b49f26SAndy Lutomirski	  option from 1 to 0, which turns off the 32-bit vDSO entirely.
2290b0b49f26SAndy Lutomirski	  This works around the glibc bug but hurts performance.
2291b0b49f26SAndy Lutomirski
2292b0b49f26SAndy Lutomirski	  If unsure, say N: if you are compiling your own kernel, you
2293b0b49f26SAndy Lutomirski	  are unlikely to be using a buggy version of glibc.
2294506f1d07SSam Ravnborg
22953dc33bd3SKees Cookchoice
22963dc33bd3SKees Cook	prompt "vsyscall table for legacy applications"
22973dc33bd3SKees Cook	depends on X86_64
22983dc33bd3SKees Cook	default LEGACY_VSYSCALL_EMULATE
22993dc33bd3SKees Cook	help
23003dc33bd3SKees Cook	  Legacy user code that does not know how to find the vDSO expects
23013dc33bd3SKees Cook	  to be able to issue three syscalls by calling fixed addresses in
23023dc33bd3SKees Cook	  kernel space. Since this location is not randomized with ASLR,
23033dc33bd3SKees Cook	  it can be used to assist security vulnerability exploitation.
23043dc33bd3SKees Cook
23053dc33bd3SKees Cook	  This setting can be changed at boot time via the kernel command
2306076ca272SAndy Lutomirski	  line parameter vsyscall=[emulate|none].
23073dc33bd3SKees Cook
23083dc33bd3SKees Cook	  On a system with recent enough glibc (2.14 or newer) and no
23093dc33bd3SKees Cook	  static binaries, you can say None without a performance penalty
23103dc33bd3SKees Cook	  to improve security.
23113dc33bd3SKees Cook
23123dc33bd3SKees Cook	  If unsure, select "Emulate".
23133dc33bd3SKees Cook
23143dc33bd3SKees Cook	config LEGACY_VSYSCALL_EMULATE
23153dc33bd3SKees Cook		bool "Emulate"
23163dc33bd3SKees Cook		help
23173dc33bd3SKees Cook		  The kernel traps and emulates calls into the fixed
23183dc33bd3SKees Cook		  vsyscall address mapping. This makes the mapping
23193dc33bd3SKees Cook		  non-executable, but it still contains known contents,
23203dc33bd3SKees Cook		  which could be used in certain rare security vulnerability
23213dc33bd3SKees Cook		  exploits. This configuration is recommended when userspace
23223dc33bd3SKees Cook		  still uses the vsyscall area.
23233dc33bd3SKees Cook
23243dc33bd3SKees Cook	config LEGACY_VSYSCALL_NONE
23253dc33bd3SKees Cook		bool "None"
23263dc33bd3SKees Cook		help
23273dc33bd3SKees Cook		  There will be no vsyscall mapping at all. This will
23283dc33bd3SKees Cook		  eliminate any risk of ASLR bypass due to the vsyscall
23293dc33bd3SKees Cook		  fixed address mapping. Attempts to use the vsyscalls
23303dc33bd3SKees Cook		  will be reported to dmesg, so that either old or
23313dc33bd3SKees Cook		  malicious userspace programs can be identified.
23323dc33bd3SKees Cook
23333dc33bd3SKees Cookendchoice
23343dc33bd3SKees Cook
2335516cbf37STim Birdconfig CMDLINE_BOOL
2336516cbf37STim Bird	bool "Built-in kernel command line"
23378f9ca475SIngo Molnar	---help---
2338516cbf37STim Bird	  Allow for specifying boot arguments to the kernel at
2339516cbf37STim Bird	  build time.  On some systems (e.g. embedded ones), it is
2340516cbf37STim Bird	  necessary or convenient to provide some or all of the
2341516cbf37STim Bird	  kernel boot arguments with the kernel itself (that is,
2342516cbf37STim Bird	  to not rely on the boot loader to provide them.)
2343516cbf37STim Bird
2344516cbf37STim Bird	  To compile command line arguments into the kernel,
2345516cbf37STim Bird	  set this option to 'Y', then fill in the
234669711ca1SSébastien Hinderer	  boot arguments in CONFIG_CMDLINE.
2347516cbf37STim Bird
2348516cbf37STim Bird	  Systems with fully functional boot loaders (i.e. non-embedded)
2349516cbf37STim Bird	  should leave this option set to 'N'.
2350516cbf37STim Bird
2351516cbf37STim Birdconfig CMDLINE
2352516cbf37STim Bird	string "Built-in kernel command string"
2353516cbf37STim Bird	depends on CMDLINE_BOOL
2354516cbf37STim Bird	default ""
23558f9ca475SIngo Molnar	---help---
2356516cbf37STim Bird	  Enter arguments here that should be compiled into the kernel
2357516cbf37STim Bird	  image and used at boot time.  If the boot loader provides a
2358516cbf37STim Bird	  command line at boot time, it is appended to this string to
2359516cbf37STim Bird	  form the full kernel command line, when the system boots.
2360516cbf37STim Bird
2361516cbf37STim Bird	  However, you can use the CONFIG_CMDLINE_OVERRIDE option to
2362516cbf37STim Bird	  change this behavior.
2363516cbf37STim Bird
2364516cbf37STim Bird	  In most cases, the command line (whether built-in or provided
2365516cbf37STim Bird	  by the boot loader) should specify the device for the root
2366516cbf37STim Bird	  file system.
2367516cbf37STim Bird
2368516cbf37STim Birdconfig CMDLINE_OVERRIDE
2369516cbf37STim Bird	bool "Built-in command line overrides boot loader arguments"
2370516cbf37STim Bird	depends on CMDLINE_BOOL
23718f9ca475SIngo Molnar	---help---
2372516cbf37STim Bird	  Set this option to 'Y' to have the kernel ignore the boot loader
2373516cbf37STim Bird	  command line, and use ONLY the built-in command line.
2374516cbf37STim Bird
2375516cbf37STim Bird	  This is used to work around broken boot loaders.  This should
2376516cbf37STim Bird	  be set to 'N' under normal conditions.
2377516cbf37STim Bird
2378a5b9e5a2SAndy Lutomirskiconfig MODIFY_LDT_SYSCALL
2379a5b9e5a2SAndy Lutomirski	bool "Enable the LDT (local descriptor table)" if EXPERT
2380a5b9e5a2SAndy Lutomirski	default y
2381a5b9e5a2SAndy Lutomirski	---help---
2382a5b9e5a2SAndy Lutomirski	  Linux can allow user programs to install a per-process x86
2383a5b9e5a2SAndy Lutomirski	  Local Descriptor Table (LDT) using the modify_ldt(2) system
2384a5b9e5a2SAndy Lutomirski	  call.  This is required to run 16-bit or segmented code such as
2385a5b9e5a2SAndy Lutomirski	  DOSEMU or some Wine programs.  It is also used by some very old
2386a5b9e5a2SAndy Lutomirski	  threading libraries.
2387a5b9e5a2SAndy Lutomirski
2388a5b9e5a2SAndy Lutomirski	  Enabling this feature adds a small amount of overhead to
2389a5b9e5a2SAndy Lutomirski	  context switches and increases the low-level kernel attack
2390a5b9e5a2SAndy Lutomirski	  surface.  Disabling it removes the modify_ldt(2) system call.
2391a5b9e5a2SAndy Lutomirski
2392a5b9e5a2SAndy Lutomirski	  Saying 'N' here may make sense for embedded or server kernels.
2393a5b9e5a2SAndy Lutomirski
2394b700e7f0SSeth Jenningssource "kernel/livepatch/Kconfig"
2395b700e7f0SSeth Jennings
2396506f1d07SSam Ravnborgendmenu
2397506f1d07SSam Ravnborg
23983072e413SMichal Hockoconfig ARCH_HAS_ADD_PAGES
23993072e413SMichal Hocko	def_bool y
24003072e413SMichal Hocko	depends on X86_64 && ARCH_ENABLE_MEMORY_HOTPLUG
24013072e413SMichal Hocko
2402506f1d07SSam Ravnborgconfig ARCH_ENABLE_MEMORY_HOTPLUG
2403506f1d07SSam Ravnborg	def_bool y
2404506f1d07SSam Ravnborg	depends on X86_64 || (X86_32 && HIGHMEM)
2405506f1d07SSam Ravnborg
240635551053SGary Hadeconfig ARCH_ENABLE_MEMORY_HOTREMOVE
240735551053SGary Hade	def_bool y
240835551053SGary Hade	depends on MEMORY_HOTPLUG
240935551053SGary Hade
2410e534c7c5SLee Schermerhornconfig USE_PERCPU_NUMA_NODE_ID
2411645a7919STejun Heo	def_bool y
2412e534c7c5SLee Schermerhorn	depends on NUMA
2413e534c7c5SLee Schermerhorn
24149491846fSKirill A. Shutemovconfig ARCH_ENABLE_SPLIT_PMD_PTLOCK
24159491846fSKirill A. Shutemov	def_bool y
24169491846fSKirill A. Shutemov	depends on X86_64 || X86_PAE
24179491846fSKirill A. Shutemov
2418c177c81eSNaoya Horiguchiconfig ARCH_ENABLE_HUGEPAGE_MIGRATION
2419c177c81eSNaoya Horiguchi	def_bool y
2420c177c81eSNaoya Horiguchi	depends on X86_64 && HUGETLB_PAGE && MIGRATION
2421c177c81eSNaoya Horiguchi
24229c670ea3SNaoya Horiguchiconfig ARCH_ENABLE_THP_MIGRATION
24239c670ea3SNaoya Horiguchi	def_bool y
24249c670ea3SNaoya Horiguchi	depends on X86_64 && TRANSPARENT_HUGEPAGE
24259c670ea3SNaoya Horiguchi
2426da85f865SBjorn Helgaasmenu "Power management and ACPI options"
2427e279b6c1SSam Ravnborg
2428e279b6c1SSam Ravnborgconfig ARCH_HIBERNATION_HEADER
24293c2362e6SHarvey Harrison	def_bool y
2430e279b6c1SSam Ravnborg	depends on X86_64 && HIBERNATION
2431e279b6c1SSam Ravnborg
2432e279b6c1SSam Ravnborgsource "kernel/power/Kconfig"
2433e279b6c1SSam Ravnborg
2434e279b6c1SSam Ravnborgsource "drivers/acpi/Kconfig"
2435e279b6c1SSam Ravnborg
2436efafc8b2SFeng Tangsource "drivers/sfi/Kconfig"
2437efafc8b2SFeng Tang
2438a6b68076SAndi Kleenconfig X86_APM_BOOT
24396fc108a0SJan Beulich	def_bool y
2440282e5aabSPaul Bolle	depends on APM
2441a6b68076SAndi Kleen
2442e279b6c1SSam Ravnborgmenuconfig APM
2443e279b6c1SSam Ravnborg	tristate "APM (Advanced Power Management) BIOS support"
2444efefa6f6SIngo Molnar	depends on X86_32 && PM_SLEEP
2445e279b6c1SSam Ravnborg	---help---
2446e279b6c1SSam Ravnborg	  APM is a BIOS specification for saving power using several different
2447e279b6c1SSam Ravnborg	  techniques. This is mostly useful for battery powered laptops with
2448e279b6c1SSam Ravnborg	  APM compliant BIOSes. If you say Y here, the system time will be
2449e279b6c1SSam Ravnborg	  reset after a RESUME operation, the /proc/apm device will provide
2450e279b6c1SSam Ravnborg	  battery status information, and user-space programs will receive
2451e279b6c1SSam Ravnborg	  notification of APM "events" (e.g. battery status change).
2452e279b6c1SSam Ravnborg
2453e279b6c1SSam Ravnborg	  If you select "Y" here, you can disable actual use of the APM
2454e279b6c1SSam Ravnborg	  BIOS by passing the "apm=off" option to the kernel at boot time.
2455e279b6c1SSam Ravnborg
2456e279b6c1SSam Ravnborg	  Note that the APM support is almost completely disabled for
2457e279b6c1SSam Ravnborg	  machines with more than one CPU.
2458e279b6c1SSam Ravnborg
2459e279b6c1SSam Ravnborg	  In order to use APM, you will need supporting software. For location
24602dc98fd3SMichael Witten	  and more information, read <file:Documentation/power/apm-acpi.txt>
24612dc98fd3SMichael Witten	  and the Battery Powered Linux mini-HOWTO, available from
2462e279b6c1SSam Ravnborg	  <http://www.tldp.org/docs.html#howto>.
2463e279b6c1SSam Ravnborg
2464e279b6c1SSam Ravnborg	  This driver does not spin down disk drives (see the hdparm(8)
2465e279b6c1SSam Ravnborg	  manpage ("man 8 hdparm") for that), and it doesn't turn off
2466e279b6c1SSam Ravnborg	  VESA-compliant "green" monitors.
2467e279b6c1SSam Ravnborg
2468e279b6c1SSam Ravnborg	  This driver does not support the TI 4000M TravelMate and the ACER
2469e279b6c1SSam Ravnborg	  486/DX4/75 because they don't have compliant BIOSes. Many "green"
2470e279b6c1SSam Ravnborg	  desktop machines also don't have compliant BIOSes, and this driver
2471e279b6c1SSam Ravnborg	  may cause those machines to panic during the boot phase.
2472e279b6c1SSam Ravnborg
2473e279b6c1SSam Ravnborg	  Generally, if you don't have a battery in your machine, there isn't
2474e279b6c1SSam Ravnborg	  much point in using this driver and you should say N. If you get
2475e279b6c1SSam Ravnborg	  random kernel OOPSes or reboots that don't seem to be related to
2476e279b6c1SSam Ravnborg	  anything, try disabling/enabling this option (or disabling/enabling
2477e279b6c1SSam Ravnborg	  APM in your BIOS).
2478e279b6c1SSam Ravnborg
2479e279b6c1SSam Ravnborg	  Some other things you should try when experiencing seemingly random,
2480e279b6c1SSam Ravnborg	  "weird" problems:
2481e279b6c1SSam Ravnborg
2482e279b6c1SSam Ravnborg	  1) make sure that you have enough swap space and that it is
2483e279b6c1SSam Ravnborg	  enabled.
2484e279b6c1SSam Ravnborg	  2) pass the "no-hlt" option to the kernel
2485e279b6c1SSam Ravnborg	  3) switch on floating point emulation in the kernel and pass
2486e279b6c1SSam Ravnborg	  the "no387" option to the kernel
2487e279b6c1SSam Ravnborg	  4) pass the "floppy=nodma" option to the kernel
2488e279b6c1SSam Ravnborg	  5) pass the "mem=4M" option to the kernel (thereby disabling
2489e279b6c1SSam Ravnborg	  all but the first 4 MB of RAM)
2490e279b6c1SSam Ravnborg	  6) make sure that the CPU is not over clocked.
2491e279b6c1SSam Ravnborg	  7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/>
2492e279b6c1SSam Ravnborg	  8) disable the cache from your BIOS settings
2493e279b6c1SSam Ravnborg	  9) install a fan for the video card or exchange video RAM
2494e279b6c1SSam Ravnborg	  10) install a better fan for the CPU
2495e279b6c1SSam Ravnborg	  11) exchange RAM chips
2496e279b6c1SSam Ravnborg	  12) exchange the motherboard.
2497e279b6c1SSam Ravnborg
2498e279b6c1SSam Ravnborg	  To compile this driver as a module, choose M here: the
2499e279b6c1SSam Ravnborg	  module will be called apm.
2500e279b6c1SSam Ravnborg
2501e279b6c1SSam Ravnborgif APM
2502e279b6c1SSam Ravnborg
2503e279b6c1SSam Ravnborgconfig APM_IGNORE_USER_SUSPEND
2504e279b6c1SSam Ravnborg	bool "Ignore USER SUSPEND"
25058f9ca475SIngo Molnar	---help---
2506e279b6c1SSam Ravnborg	  This option will ignore USER SUSPEND requests. On machines with a
2507e279b6c1SSam Ravnborg	  compliant APM BIOS, you want to say N. However, on the NEC Versa M
2508e279b6c1SSam Ravnborg	  series notebooks, it is necessary to say Y because of a BIOS bug.
2509e279b6c1SSam Ravnborg
2510e279b6c1SSam Ravnborgconfig APM_DO_ENABLE
2511e279b6c1SSam Ravnborg	bool "Enable PM at boot time"
2512e279b6c1SSam Ravnborg	---help---
2513e279b6c1SSam Ravnborg	  Enable APM features at boot time. From page 36 of the APM BIOS
2514e279b6c1SSam Ravnborg	  specification: "When disabled, the APM BIOS does not automatically
2515e279b6c1SSam Ravnborg	  power manage devices, enter the Standby State, enter the Suspend
2516e279b6c1SSam Ravnborg	  State, or take power saving steps in response to CPU Idle calls."
2517e279b6c1SSam Ravnborg	  This driver will make CPU Idle calls when Linux is idle (unless this
2518e279b6c1SSam Ravnborg	  feature is turned off -- see "Do CPU IDLE calls", below). This
2519e279b6c1SSam Ravnborg	  should always save battery power, but more complicated APM features
2520e279b6c1SSam Ravnborg	  will be dependent on your BIOS implementation. You may need to turn
2521e279b6c1SSam Ravnborg	  this option off if your computer hangs at boot time when using APM
2522e279b6c1SSam Ravnborg	  support, or if it beeps continuously instead of suspending. Turn
2523e279b6c1SSam Ravnborg	  this off if you have a NEC UltraLite Versa 33/C or a Toshiba
2524e279b6c1SSam Ravnborg	  T400CDT. This is off by default since most machines do fine without
2525e279b6c1SSam Ravnborg	  this feature.
2526e279b6c1SSam Ravnborg
2527e279b6c1SSam Ravnborgconfig APM_CPU_IDLE
2528dd8af076SLen Brown	depends on CPU_IDLE
2529e279b6c1SSam Ravnborg	bool "Make CPU Idle calls when idle"
25308f9ca475SIngo Molnar	---help---
2531e279b6c1SSam Ravnborg	  Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop.
2532e279b6c1SSam Ravnborg	  On some machines, this can activate improved power savings, such as
2533e279b6c1SSam Ravnborg	  a slowed CPU clock rate, when the machine is idle. These idle calls
2534e279b6c1SSam Ravnborg	  are made after the idle loop has run for some length of time (e.g.,
2535e279b6c1SSam Ravnborg	  333 mS). On some machines, this will cause a hang at boot time or
2536e279b6c1SSam Ravnborg	  whenever the CPU becomes idle. (On machines with more than one CPU,
2537e279b6c1SSam Ravnborg	  this option does nothing.)
2538e279b6c1SSam Ravnborg
2539e279b6c1SSam Ravnborgconfig APM_DISPLAY_BLANK
2540e279b6c1SSam Ravnborg	bool "Enable console blanking using APM"
25418f9ca475SIngo Molnar	---help---
2542e279b6c1SSam Ravnborg	  Enable console blanking using the APM. Some laptops can use this to
2543e279b6c1SSam Ravnborg	  turn off the LCD backlight when the screen blanker of the Linux
2544e279b6c1SSam Ravnborg	  virtual console blanks the screen. Note that this is only used by
2545e279b6c1SSam Ravnborg	  the virtual console screen blanker, and won't turn off the backlight
2546e279b6c1SSam Ravnborg	  when using the X Window system. This also doesn't have anything to
2547e279b6c1SSam Ravnborg	  do with your VESA-compliant power-saving monitor. Further, this
2548e279b6c1SSam Ravnborg	  option doesn't work for all laptops -- it might not turn off your
2549e279b6c1SSam Ravnborg	  backlight at all, or it might print a lot of errors to the console,
2550e279b6c1SSam Ravnborg	  especially if you are using gpm.
2551e279b6c1SSam Ravnborg
2552e279b6c1SSam Ravnborgconfig APM_ALLOW_INTS
2553e279b6c1SSam Ravnborg	bool "Allow interrupts during APM BIOS calls"
25548f9ca475SIngo Molnar	---help---
2555e279b6c1SSam Ravnborg	  Normally we disable external interrupts while we are making calls to
2556e279b6c1SSam Ravnborg	  the APM BIOS as a measure to lessen the effects of a badly behaving
2557e279b6c1SSam Ravnborg	  BIOS implementation.  The BIOS should reenable interrupts if it
2558e279b6c1SSam Ravnborg	  needs to.  Unfortunately, some BIOSes do not -- especially those in
2559e279b6c1SSam Ravnborg	  many of the newer IBM Thinkpads.  If you experience hangs when you
2560e279b6c1SSam Ravnborg	  suspend, try setting this to Y.  Otherwise, say N.
2561e279b6c1SSam Ravnborg
2562e279b6c1SSam Ravnborgendif # APM
2563e279b6c1SSam Ravnborg
2564bb0a56ecSDave Jonessource "drivers/cpufreq/Kconfig"
2565e279b6c1SSam Ravnborg
2566e279b6c1SSam Ravnborgsource "drivers/cpuidle/Kconfig"
2567e279b6c1SSam Ravnborg
256827471fdbSAndy Henroidsource "drivers/idle/Kconfig"
256927471fdbSAndy Henroid
2570e279b6c1SSam Ravnborgendmenu
2571e279b6c1SSam Ravnborg
2572e279b6c1SSam Ravnborg
2573e279b6c1SSam Ravnborgmenu "Bus options (PCI etc.)"
2574e279b6c1SSam Ravnborg
2575e279b6c1SSam Ravnborgconfig PCI
25761ac97018SIngo Molnar	bool "PCI support"
25771c858087SAdrian Bunk	default y
25788f9ca475SIngo Molnar	---help---
2579e279b6c1SSam Ravnborg	  Find out whether you have a PCI motherboard. PCI is the name of a
2580e279b6c1SSam Ravnborg	  bus system, i.e. the way the CPU talks to the other stuff inside
2581e279b6c1SSam Ravnborg	  your box. Other bus systems are ISA, EISA, MicroChannel (MCA) or
2582e279b6c1SSam Ravnborg	  VESA. If you have PCI, say Y, otherwise N.
2583e279b6c1SSam Ravnborg
2584e279b6c1SSam Ravnborgchoice
2585e279b6c1SSam Ravnborg	prompt "PCI access mode"
2586efefa6f6SIngo Molnar	depends on X86_32 && PCI
2587e279b6c1SSam Ravnborg	default PCI_GOANY
2588e279b6c1SSam Ravnborg	---help---
2589e279b6c1SSam Ravnborg	  On PCI systems, the BIOS can be used to detect the PCI devices and
2590e279b6c1SSam Ravnborg	  determine their configuration. However, some old PCI motherboards
2591e279b6c1SSam Ravnborg	  have BIOS bugs and may crash if this is done. Also, some embedded
2592e279b6c1SSam Ravnborg	  PCI-based systems don't have any BIOS at all. Linux can also try to
2593e279b6c1SSam Ravnborg	  detect the PCI hardware directly without using the BIOS.
2594e279b6c1SSam Ravnborg
2595e279b6c1SSam Ravnborg	  With this option, you can specify how Linux should detect the
2596e279b6c1SSam Ravnborg	  PCI devices. If you choose "BIOS", the BIOS will be used,
2597e279b6c1SSam Ravnborg	  if you choose "Direct", the BIOS won't be used, and if you
2598e279b6c1SSam Ravnborg	  choose "MMConfig", then PCI Express MMCONFIG will be used.
2599e279b6c1SSam Ravnborg	  If you choose "Any", the kernel will try MMCONFIG, then the
2600e279b6c1SSam Ravnborg	  direct access method and falls back to the BIOS if that doesn't
2601e279b6c1SSam Ravnborg	  work. If unsure, go with the default, which is "Any".
2602e279b6c1SSam Ravnborg
2603e279b6c1SSam Ravnborgconfig PCI_GOBIOS
2604e279b6c1SSam Ravnborg	bool "BIOS"
2605e279b6c1SSam Ravnborg
2606e279b6c1SSam Ravnborgconfig PCI_GOMMCONFIG
2607e279b6c1SSam Ravnborg	bool "MMConfig"
2608e279b6c1SSam Ravnborg
2609e279b6c1SSam Ravnborgconfig PCI_GODIRECT
2610e279b6c1SSam Ravnborg	bool "Direct"
2611e279b6c1SSam Ravnborg
26123ef0e1f8SAndres Salomonconfig PCI_GOOLPC
261376fb6570SDaniel Drake	bool "OLPC XO-1"
26143ef0e1f8SAndres Salomon	depends on OLPC
26153ef0e1f8SAndres Salomon
26162bdd1b03SAndres Salomonconfig PCI_GOANY
26172bdd1b03SAndres Salomon	bool "Any"
26182bdd1b03SAndres Salomon
2619e279b6c1SSam Ravnborgendchoice
2620e279b6c1SSam Ravnborg
2621e279b6c1SSam Ravnborgconfig PCI_BIOS
26223c2362e6SHarvey Harrison	def_bool y
2623efefa6f6SIngo Molnar	depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY)
2624e279b6c1SSam Ravnborg
2625e279b6c1SSam Ravnborg# x86-64 doesn't support PCI BIOS access from long mode so always go direct.
2626e279b6c1SSam Ravnborgconfig PCI_DIRECT
26273c2362e6SHarvey Harrison	def_bool y
26280aba496fSShaohua Li	depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC || PCI_GOMMCONFIG))
2629e279b6c1SSam Ravnborg
2630e279b6c1SSam Ravnborgconfig PCI_MMCONFIG
2631b45c9f36SJan Kiszka	bool "Support mmconfig PCI config space access" if X86_64
2632b45c9f36SJan Kiszka	default y
26338364e1f8SJan Kiszka	depends on PCI && (ACPI || SFI || JAILHOUSE_GUEST)
2634b45c9f36SJan Kiszka	depends on X86_64 || (PCI_GOANY || PCI_GOMMCONFIG)
2635e279b6c1SSam Ravnborg
26363ef0e1f8SAndres Salomonconfig PCI_OLPC
26372bdd1b03SAndres Salomon	def_bool y
26382bdd1b03SAndres Salomon	depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY)
26393ef0e1f8SAndres Salomon
2640b5401a96SAlex Nixonconfig PCI_XEN
2641b5401a96SAlex Nixon	def_bool y
2642b5401a96SAlex Nixon	depends on PCI && XEN
2643b5401a96SAlex Nixon	select SWIOTLB_XEN
2644b5401a96SAlex Nixon
2645e279b6c1SSam Ravnborgconfig PCI_DOMAINS
26463c2362e6SHarvey Harrison	def_bool y
2647e279b6c1SSam Ravnborg	depends on PCI
2648e279b6c1SSam Ravnborg
26498364e1f8SJan Kiszkaconfig MMCONF_FAM10H
26508364e1f8SJan Kiszka	def_bool y
26518364e1f8SJan Kiszka	depends on X86_64 && PCI_MMCONFIG && ACPI
2652e279b6c1SSam Ravnborg
26533f6ea84aSIra W. Snyderconfig PCI_CNB20LE_QUIRK
26546a108a14SDavid Rientjes	bool "Read CNB20LE Host Bridge Windows" if EXPERT
26556ea30386SKees Cook	depends on PCI
26563f6ea84aSIra W. Snyder	help
26573f6ea84aSIra W. Snyder	  Read the PCI windows out of the CNB20LE host bridge. This allows
26583f6ea84aSIra W. Snyder	  PCI hotplug to work on systems with the CNB20LE chipset which do
26593f6ea84aSIra W. Snyder	  not have ACPI.
26603f6ea84aSIra W. Snyder
266164a5fed6SBjorn Helgaas	  There's no public spec for this chipset, and this functionality
266264a5fed6SBjorn Helgaas	  is known to be incomplete.
266364a5fed6SBjorn Helgaas
266464a5fed6SBjorn Helgaas	  You should say N unless you know you need this.
266564a5fed6SBjorn Helgaas
2666e279b6c1SSam Ravnborgsource "drivers/pci/Kconfig"
2667e279b6c1SSam Ravnborg
26683a495511SWilliam Breathitt Grayconfig ISA_BUS
266917a2a129SWilliam Breathitt Gray	bool "ISA bus support on modern systems" if EXPERT
26703a495511SWilliam Breathitt Gray	help
267117a2a129SWilliam Breathitt Gray	  Expose ISA bus device drivers and options available for selection and
267217a2a129SWilliam Breathitt Gray	  configuration. Enable this option if your target machine has an ISA
267317a2a129SWilliam Breathitt Gray	  bus. ISA is an older system, displaced by PCI and newer bus
267417a2a129SWilliam Breathitt Gray	  architectures -- if your target machine is modern, it probably does
267517a2a129SWilliam Breathitt Gray	  not have an ISA bus.
26763a495511SWilliam Breathitt Gray
26773a495511SWilliam Breathitt Gray	  If unsure, say N.
26783a495511SWilliam Breathitt Gray
26791c00f016SDavid Rientjes# x86_64 have no ISA slots, but can have ISA-style DMA.
2680e279b6c1SSam Ravnborgconfig ISA_DMA_API
26811c00f016SDavid Rientjes	bool "ISA-style DMA support" if (X86_64 && EXPERT)
26821c00f016SDavid Rientjes	default y
26831c00f016SDavid Rientjes	help
26841c00f016SDavid Rientjes	  Enables ISA-style DMA support for devices requiring such controllers.
26851c00f016SDavid Rientjes	  If unsure, say Y.
2686e279b6c1SSam Ravnborg
268751e68d05SLinus Torvaldsif X86_32
268851e68d05SLinus Torvalds
2689e279b6c1SSam Ravnborgconfig ISA
2690e279b6c1SSam Ravnborg	bool "ISA support"
26918f9ca475SIngo Molnar	---help---
2692e279b6c1SSam Ravnborg	  Find out whether you have ISA slots on your motherboard.  ISA is the
2693e279b6c1SSam Ravnborg	  name of a bus system, i.e. the way the CPU talks to the other stuff
2694e279b6c1SSam Ravnborg	  inside your box.  Other bus systems are PCI, EISA, MicroChannel
2695e279b6c1SSam Ravnborg	  (MCA) or VESA.  ISA is an older system, now being displaced by PCI;
2696e279b6c1SSam Ravnborg	  newer boards don't support it.  If you have ISA, say Y, otherwise N.
2697e279b6c1SSam Ravnborg
2698e279b6c1SSam Ravnborgconfig EISA
2699e279b6c1SSam Ravnborg	bool "EISA support"
2700e279b6c1SSam Ravnborg	depends on ISA
2701e279b6c1SSam Ravnborg	---help---
2702e279b6c1SSam Ravnborg	  The Extended Industry Standard Architecture (EISA) bus was
2703e279b6c1SSam Ravnborg	  developed as an open alternative to the IBM MicroChannel bus.
2704e279b6c1SSam Ravnborg
2705e279b6c1SSam Ravnborg	  The EISA bus provided some of the features of the IBM MicroChannel
2706e279b6c1SSam Ravnborg	  bus while maintaining backward compatibility with cards made for
2707e279b6c1SSam Ravnborg	  the older ISA bus.  The EISA bus saw limited use between 1988 and
2708e279b6c1SSam Ravnborg	  1995 when it was made obsolete by the PCI bus.
2709e279b6c1SSam Ravnborg
2710e279b6c1SSam Ravnborg	  Say Y here if you are building a kernel for an EISA-based machine.
2711e279b6c1SSam Ravnborg
2712e279b6c1SSam Ravnborg	  Otherwise, say N.
2713e279b6c1SSam Ravnborg
2714e279b6c1SSam Ravnborgsource "drivers/eisa/Kconfig"
2715e279b6c1SSam Ravnborg
2716e279b6c1SSam Ravnborgconfig SCx200
2717e279b6c1SSam Ravnborg	tristate "NatSemi SCx200 support"
27188f9ca475SIngo Molnar	---help---
2719e279b6c1SSam Ravnborg	  This provides basic support for National Semiconductor's
2720e279b6c1SSam Ravnborg	  (now AMD's) Geode processors.  The driver probes for the
2721e279b6c1SSam Ravnborg	  PCI-IDs of several on-chip devices, so its a good dependency
2722e279b6c1SSam Ravnborg	  for other scx200_* drivers.
2723e279b6c1SSam Ravnborg
2724e279b6c1SSam Ravnborg	  If compiled as a module, the driver is named scx200.
2725e279b6c1SSam Ravnborg
2726e279b6c1SSam Ravnborgconfig SCx200HR_TIMER
2727e279b6c1SSam Ravnborg	tristate "NatSemi SCx200 27MHz High-Resolution Timer Support"
2728592913ecSJohn Stultz	depends on SCx200
2729e279b6c1SSam Ravnborg	default y
27308f9ca475SIngo Molnar	---help---
2731e279b6c1SSam Ravnborg	  This driver provides a clocksource built upon the on-chip
2732e279b6c1SSam Ravnborg	  27MHz high-resolution timer.  Its also a workaround for
2733e279b6c1SSam Ravnborg	  NSC Geode SC-1100's buggy TSC, which loses time when the
2734e279b6c1SSam Ravnborg	  processor goes idle (as is done by the scheduler).  The
2735e279b6c1SSam Ravnborg	  other workaround is idle=poll boot option.
2736e279b6c1SSam Ravnborg
27373ef0e1f8SAndres Salomonconfig OLPC
27383ef0e1f8SAndres Salomon	bool "One Laptop Per Child support"
273954008979SThomas Gleixner	depends on !X86_PAE
27403c554946SAndres Salomon	select GPIOLIB
2741dc3119e7SThomas Gleixner	select OF
274245bb1674SDaniel Drake	select OF_PROMTREE
2743b4e51854SGrant Likely	select IRQ_DOMAIN
27448f9ca475SIngo Molnar	---help---
27453ef0e1f8SAndres Salomon	  Add support for detecting the unique features of the OLPC
27463ef0e1f8SAndres Salomon	  XO hardware.
27473ef0e1f8SAndres Salomon
2748a3128588SDaniel Drakeconfig OLPC_XO1_PM
2749a3128588SDaniel Drake	bool "OLPC XO-1 Power Management"
275097c4cb71SDaniel Drake	depends on OLPC && MFD_CS5535 && PM_SLEEP
2751a3128588SDaniel Drake	select MFD_CORE
2752bf1ebf00SDaniel Drake	---help---
275397c4cb71SDaniel Drake	  Add support for poweroff and suspend of the OLPC XO-1 laptop.
2754bf1ebf00SDaniel Drake
2755cfee9597SDaniel Drakeconfig OLPC_XO1_RTC
2756cfee9597SDaniel Drake	bool "OLPC XO-1 Real Time Clock"
2757cfee9597SDaniel Drake	depends on OLPC_XO1_PM && RTC_DRV_CMOS
2758cfee9597SDaniel Drake	---help---
2759cfee9597SDaniel Drake	  Add support for the XO-1 real time clock, which can be used as a
2760cfee9597SDaniel Drake	  programmable wakeup source.
2761cfee9597SDaniel Drake
27627feda8e9SDaniel Drakeconfig OLPC_XO1_SCI
27637feda8e9SDaniel Drake	bool "OLPC XO-1 SCI extras"
276492e830f2SArnd Bergmann	depends on OLPC && OLPC_XO1_PM && GPIO_CS5535=y
2765ed8e47feSRandy Dunlap	depends on INPUT=y
2766d8d01a63SDaniel Drake	select POWER_SUPPLY
27677feda8e9SDaniel Drake	---help---
27687feda8e9SDaniel Drake	  Add support for SCI-based features of the OLPC XO-1 laptop:
27697bc74b3dSDaniel Drake	   - EC-driven system wakeups
27707feda8e9SDaniel Drake	   - Power button
27717bc74b3dSDaniel Drake	   - Ebook switch
27722cf2baeaSDaniel Drake	   - Lid switch
2773e1040ac6SDaniel Drake	   - AC adapter status updates
2774e1040ac6SDaniel Drake	   - Battery status updates
27757feda8e9SDaniel Drake
2776a0f30f59SDaniel Drakeconfig OLPC_XO15_SCI
2777a0f30f59SDaniel Drake	bool "OLPC XO-1.5 SCI extras"
2778d8d01a63SDaniel Drake	depends on OLPC && ACPI
2779d8d01a63SDaniel Drake	select POWER_SUPPLY
2780a0f30f59SDaniel Drake	---help---
2781a0f30f59SDaniel Drake	  Add support for SCI-based features of the OLPC XO-1.5 laptop:
2782a0f30f59SDaniel Drake	   - EC-driven system wakeups
2783a0f30f59SDaniel Drake	   - AC adapter status updates
2784a0f30f59SDaniel Drake	   - Battery status updates
2785e279b6c1SSam Ravnborg
2786d4f3e350SEd Wildgooseconfig ALIX
2787d4f3e350SEd Wildgoose	bool "PCEngines ALIX System Support (LED setup)"
2788d4f3e350SEd Wildgoose	select GPIOLIB
2789d4f3e350SEd Wildgoose	---help---
2790d4f3e350SEd Wildgoose	  This option enables system support for the PCEngines ALIX.
2791d4f3e350SEd Wildgoose	  At present this just sets up LEDs for GPIO control on
2792d4f3e350SEd Wildgoose	  ALIX2/3/6 boards.  However, other system specific setup should
2793d4f3e350SEd Wildgoose	  get added here.
2794d4f3e350SEd Wildgoose
2795d4f3e350SEd Wildgoose	  Note: You must still enable the drivers for GPIO and LED support
2796d4f3e350SEd Wildgoose	  (GPIO_CS5535 & LEDS_GPIO) to actually use the LEDs
2797d4f3e350SEd Wildgoose
2798d4f3e350SEd Wildgoose	  Note: You have to set alix.force=1 for boards with Award BIOS.
2799d4f3e350SEd Wildgoose
2800da4e3302SPhilip Prindevilleconfig NET5501
2801da4e3302SPhilip Prindeville	bool "Soekris Engineering net5501 System Support (LEDS, GPIO, etc)"
2802da4e3302SPhilip Prindeville	select GPIOLIB
2803da4e3302SPhilip Prindeville	---help---
2804da4e3302SPhilip Prindeville	  This option enables system support for the Soekris Engineering net5501.
2805da4e3302SPhilip Prindeville
28063197059aSPhilip A. Prindevilleconfig GEOS
28073197059aSPhilip A. Prindeville	bool "Traverse Technologies GEOS System Support (LEDS, GPIO, etc)"
28083197059aSPhilip A. Prindeville	select GPIOLIB
28093197059aSPhilip A. Prindeville	depends on DMI
28103197059aSPhilip A. Prindeville	---help---
28113197059aSPhilip A. Prindeville	  This option enables system support for the Traverse Technologies GEOS.
28123197059aSPhilip A. Prindeville
28137d029125SVivien Didelotconfig TS5500
28147d029125SVivien Didelot	bool "Technologic Systems TS-5500 platform support"
28157d029125SVivien Didelot	depends on MELAN
28167d029125SVivien Didelot	select CHECK_SIGNATURE
28177d029125SVivien Didelot	select NEW_LEDS
28187d029125SVivien Didelot	select LEDS_CLASS
28197d029125SVivien Didelot	---help---
28207d029125SVivien Didelot	  This option enables system support for the Technologic Systems TS-5500.
28217d029125SVivien Didelot
2822e279b6c1SSam Ravnborgendif # X86_32
2823e279b6c1SSam Ravnborg
282423ac4ae8SAndreas Herrmannconfig AMD_NB
2825e279b6c1SSam Ravnborg	def_bool y
28260e152cd7SBorislav Petkov	depends on CPU_SUP_AMD && PCI
2827e279b6c1SSam Ravnborg
2828e279b6c1SSam Ravnborgsource "drivers/pcmcia/Kconfig"
2829e279b6c1SSam Ravnborg
2830388b78adSAlexandre Bounineconfig RAPIDIO
2831fdf90abcSAlexandre Bounine	tristate "RapidIO support"
2832388b78adSAlexandre Bounine	depends on PCI
2833388b78adSAlexandre Bounine	default n
2834388b78adSAlexandre Bounine	help
2835fdf90abcSAlexandre Bounine	  If enabled this option will include drivers and the core
2836388b78adSAlexandre Bounine	  infrastructure code to support RapidIO interconnect devices.
2837388b78adSAlexandre Bounine
2838388b78adSAlexandre Bouninesource "drivers/rapidio/Kconfig"
2839388b78adSAlexandre Bounine
2840e3263ab3SDavid Herrmannconfig X86_SYSFB
2841e3263ab3SDavid Herrmann	bool "Mark VGA/VBE/EFI FB as generic system framebuffer"
2842e3263ab3SDavid Herrmann	help
2843e3263ab3SDavid Herrmann	  Firmwares often provide initial graphics framebuffers so the BIOS,
2844e3263ab3SDavid Herrmann	  bootloader or kernel can show basic video-output during boot for
2845e3263ab3SDavid Herrmann	  user-guidance and debugging. Historically, x86 used the VESA BIOS
2846e3263ab3SDavid Herrmann	  Extensions and EFI-framebuffers for this, which are mostly limited
2847e3263ab3SDavid Herrmann	  to x86.
2848e3263ab3SDavid Herrmann	  This option, if enabled, marks VGA/VBE/EFI framebuffers as generic
2849e3263ab3SDavid Herrmann	  framebuffers so the new generic system-framebuffer drivers can be
2850e3263ab3SDavid Herrmann	  used on x86. If the framebuffer is not compatible with the generic
2851e3263ab3SDavid Herrmann	  modes, it is adverticed as fallback platform framebuffer so legacy
2852e3263ab3SDavid Herrmann	  drivers like efifb, vesafb and uvesafb can pick it up.
2853e3263ab3SDavid Herrmann	  If this option is not selected, all system framebuffers are always
2854e3263ab3SDavid Herrmann	  marked as fallback platform framebuffers as usual.
2855e3263ab3SDavid Herrmann
2856e3263ab3SDavid Herrmann	  Note: Legacy fbdev drivers, including vesafb, efifb, uvesafb, will
2857e3263ab3SDavid Herrmann	  not be able to pick up generic system framebuffers if this option
2858e3263ab3SDavid Herrmann	  is selected. You are highly encouraged to enable simplefb as
2859e3263ab3SDavid Herrmann	  replacement if you select this option. simplefb can correctly deal
2860e3263ab3SDavid Herrmann	  with generic system framebuffers. But you should still keep vesafb
2861e3263ab3SDavid Herrmann	  and others enabled as fallback if a system framebuffer is
2862e3263ab3SDavid Herrmann	  incompatible with simplefb.
2863e3263ab3SDavid Herrmann
2864e3263ab3SDavid Herrmann	  If unsure, say Y.
2865e3263ab3SDavid Herrmann
2866e279b6c1SSam Ravnborgendmenu
2867e279b6c1SSam Ravnborg
2868e279b6c1SSam Ravnborg
2869e279b6c1SSam Ravnborgmenu "Executable file formats / Emulations"
2870e279b6c1SSam Ravnborg
2871e279b6c1SSam Ravnborgsource "fs/Kconfig.binfmt"
2872e279b6c1SSam Ravnborg
2873e279b6c1SSam Ravnborgconfig IA32_EMULATION
2874e279b6c1SSam Ravnborg	bool "IA32 Emulation"
2875e279b6c1SSam Ravnborg	depends on X86_64
287639f88911SIngo Molnar	select ARCH_WANT_OLD_COMPAT_IPC
2877d1603990SRandy Dunlap	select BINFMT_ELF
2878a97f52e6SRoland McGrath	select COMPAT_BINFMT_ELF
287939f88911SIngo Molnar	select COMPAT_OLD_SIGACTION
28808f9ca475SIngo Molnar	---help---
28815fd92e65SH. J. Lu	  Include code to run legacy 32-bit programs under a
28825fd92e65SH. J. Lu	  64-bit kernel. You should likely turn this on, unless you're
28835fd92e65SH. J. Lu	  100% sure that you don't have any 32-bit programs left.
2884e279b6c1SSam Ravnborg
2885e279b6c1SSam Ravnborgconfig IA32_AOUT
2886e279b6c1SSam Ravnborg	tristate "IA32 a.out support"
28876b213e1bSDavid Woodhouse	depends on IA32_EMULATION
28888f9ca475SIngo Molnar	---help---
2889e279b6c1SSam Ravnborg	  Support old a.out binaries in the 32bit emulation.
2890e279b6c1SSam Ravnborg
28910bf62763SH. Peter Anvinconfig X86_X32
28926ea30386SKees Cook	bool "x32 ABI for 64-bit mode"
28939b54050bSBrian Gerst	depends on X86_64
28945fd92e65SH. J. Lu	---help---
28955fd92e65SH. J. Lu	  Include code to run binaries for the x32 native 32-bit ABI
28965fd92e65SH. J. Lu	  for 64-bit processors.  An x32 process gets access to the
28975fd92e65SH. J. Lu	  full 64-bit register file and wide data path while leaving
28985fd92e65SH. J. Lu	  pointers at 32 bits for smaller memory footprint.
28995fd92e65SH. J. Lu
29005fd92e65SH. J. Lu	  You will need a recent binutils (2.22 or later) with
29015fd92e65SH. J. Lu	  elf32_x86_64 support enabled to compile a kernel with this
29025fd92e65SH. J. Lu	  option set.
29035fd92e65SH. J. Lu
2904953fee1dSIngo Molnarconfig COMPAT_32
2905953fee1dSIngo Molnar	def_bool y
2906953fee1dSIngo Molnar	depends on IA32_EMULATION || X86_32
2907953fee1dSIngo Molnar	select HAVE_UID16
2908953fee1dSIngo Molnar	select OLD_SIGSUSPEND3
2909953fee1dSIngo Molnar
2910e279b6c1SSam Ravnborgconfig COMPAT
29113c2362e6SHarvey Harrison	def_bool y
29120bf62763SH. Peter Anvin	depends on IA32_EMULATION || X86_X32
2913e279b6c1SSam Ravnborg
29143120e25eSJan Beulichif COMPAT
2915e279b6c1SSam Ravnborgconfig COMPAT_FOR_U64_ALIGNMENT
29163120e25eSJan Beulich	def_bool y
2917e279b6c1SSam Ravnborg
2918e279b6c1SSam Ravnborgconfig SYSVIPC_COMPAT
29193c2362e6SHarvey Harrison	def_bool y
29203120e25eSJan Beulich	depends on SYSVIPC
29213120e25eSJan Beulichendif
2922ee009e4aSDavid Howells
2923e279b6c1SSam Ravnborgendmenu
2924e279b6c1SSam Ravnborg
2925e279b6c1SSam Ravnborg
2926e5beae16SKeith Packardconfig HAVE_ATOMIC_IOMAP
2927e5beae16SKeith Packard	def_bool y
2928e5beae16SKeith Packard	depends on X86_32
2929e5beae16SKeith Packard
29304692d77fSAlessandro Rubiniconfig X86_DEV_DMA_OPS
29314692d77fSAlessandro Rubini	bool
293283125a3aSAlessandro Rubini	depends on X86_64 || STA2X11
29334692d77fSAlessandro Rubini
2934f7219a53SAlessandro Rubiniconfig X86_DMA_REMAP
2935f7219a53SAlessandro Rubini	bool
293683125a3aSAlessandro Rubini	depends on STA2X11
2937f7219a53SAlessandro Rubini
2938e585513bSKirill A. Shutemovconfig HAVE_GENERIC_GUP
2939e585513bSKirill A. Shutemov	def_bool y
2940e585513bSKirill A. Shutemov
2941e279b6c1SSam Ravnborgsource "net/Kconfig"
2942e279b6c1SSam Ravnborg
2943e279b6c1SSam Ravnborgsource "drivers/Kconfig"
2944e279b6c1SSam Ravnborg
2945e279b6c1SSam Ravnborgsource "drivers/firmware/Kconfig"
2946e279b6c1SSam Ravnborg
2947e279b6c1SSam Ravnborgsource "fs/Kconfig"
2948e279b6c1SSam Ravnborg
2949e279b6c1SSam Ravnborgsource "arch/x86/Kconfig.debug"
2950e279b6c1SSam Ravnborg
2951e279b6c1SSam Ravnborgsource "security/Kconfig"
2952e279b6c1SSam Ravnborg
2953e279b6c1SSam Ravnborgsource "crypto/Kconfig"
2954e279b6c1SSam Ravnborg
2955edf88417SAvi Kivitysource "arch/x86/kvm/Kconfig"
2956edf88417SAvi Kivity
2957e279b6c1SSam Ravnborgsource "lib/Kconfig"
2958