xref: /linux/arch/x86/Kconfig (revision e79f15a4598c1f3f3f7f3319ca308c63c91fdaf2)
1b2441318SGreg Kroah-Hartman# SPDX-License-Identifier: GPL-2.0
2daa93fabSSam Ravnborg# Select 32 or 64 bit
3daa93fabSSam Ravnborgconfig 64BIT
4104daea1SMasahiro Yamada	bool "64-bit kernel" if "$(ARCH)" = "x86"
5104daea1SMasahiro Yamada	default "$(ARCH)" != "i386"
68f9ca475SIngo Molnar	---help---
7daa93fabSSam Ravnborg	  Say yes to build a 64-bit kernel - formerly known as x86_64
8daa93fabSSam Ravnborg	  Say no to build a 32-bit kernel - formerly known as i386
9daa93fabSSam Ravnborg
10daa93fabSSam Ravnborgconfig X86_32
113120e25eSJan Beulich	def_bool y
123120e25eSJan Beulich	depends on !64BIT
13341c787eSIngo Molnar	# Options that are inherently 32-bit kernel only:
14341c787eSIngo Molnar	select ARCH_WANT_IPC_PARSE_VERSION
15341c787eSIngo Molnar	select CLKSRC_I8253
16341c787eSIngo Molnar	select CLONE_BACKWARDS
17117ed454SThomas Gleixner	select HAVE_DEBUG_STACKOVERFLOW
18341c787eSIngo Molnar	select MODULES_USE_ELF_REL
19341c787eSIngo Molnar	select OLD_SIGACTION
207ac87074SVincenzo Frascino	select GENERIC_VDSO_32
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:
264eb0716eSAlexandre Ghiti	select ARCH_HAS_GIGANTIC_PAGE
27c12d3362SArd Biesheuvel	select ARCH_SUPPORTS_INT128 if CC_HAS_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
33f8781c4aSDominik Brodowski	select ARCH_HAS_SYSCALL_WRAPPER
341032c0baSSam Ravnborg
35518049d9SSteven Rostedt (VMware)config FORCE_DYNAMIC_FTRACE
36518049d9SSteven Rostedt (VMware)	def_bool y
37518049d9SSteven Rostedt (VMware)	depends on X86_32
38518049d9SSteven Rostedt (VMware)	depends on FUNCTION_TRACER
39518049d9SSteven Rostedt (VMware)	select DYNAMIC_FTRACE
40518049d9SSteven Rostedt (VMware)	help
41518049d9SSteven Rostedt (VMware)	 We keep the static function tracing (!DYNAMIC_FTRACE) around
42518049d9SSteven Rostedt (VMware)	 in order to test the non static function tracing in the
43518049d9SSteven Rostedt (VMware)	 generic code, as other architectures still use it. But we
44518049d9SSteven Rostedt (VMware)	 only need to keep it around for x86_64. No need to keep it
45518049d9SSteven Rostedt (VMware)	 for x86_32. For x86_32, force DYNAMIC_FTRACE.
46d94e0685SIngo Molnar#
47d94e0685SIngo Molnar# Arch settings
48d94e0685SIngo Molnar#
49d94e0685SIngo Molnar# ( Note that options that are marked 'if X86_64' could in principle be
50d94e0685SIngo Molnar#   ported to 32-bit as well. )
51d94e0685SIngo Molnar#
528d5fffb9SSam Ravnborgconfig X86
533c2362e6SHarvey Harrison	def_bool y
54c763ea26SIngo Molnar	#
55c763ea26SIngo Molnar	# Note: keep this list sorted alphabetically
56c763ea26SIngo Molnar	#
576471b825SIngo Molnar	select ACPI_LEGACY_TABLES_LOOKUP	if ACPI
586e0a0ea1SGraeme Gregory	select ACPI_SYSTEM_POWER_STATES_SUPPORT	if ACPI
59942fa985SYury Norov	select ARCH_32BIT_OFF_T			if X86_32
606471b825SIngo Molnar	select ARCH_CLOCKSOURCE_DATA
612a21ad57SThomas Gleixner	select ARCH_CLOCKSOURCE_INIT
6291dda51aSAleksey Makarov	select ARCH_HAS_ACPI_TABLE_UPGRADE	if ACPI
63fa5b6ec9SLaura Abbott	select ARCH_HAS_DEBUG_VIRTUAL
6421266be9SDan Williams	select ARCH_HAS_DEVMEM_IS_ALLOWED
656471b825SIngo Molnar	select ARCH_HAS_ELF_RANDOMIZE
6672d93104SLinus Torvalds	select ARCH_HAS_FAST_MULTIPLIER
67316d097cSDave Hansen	select ARCH_HAS_FILTER_PGPROT
686974f0c4SDaniel Micay	select ARCH_HAS_FORTIFY_SOURCE
69957e3facSRiku Voipio	select ARCH_HAS_GCOV_PROFILE_ALL
705c9a8750SDmitry Vyukov	select ARCH_HAS_KCOV			if X86_64
710c9c1d56SThiago Jung Bauermann	select ARCH_HAS_MEM_ENCRYPT
7210bcc80eSMathieu Desnoyers	select ARCH_HAS_MEMBARRIER_SYNC_CORE
73c763ea26SIngo Molnar	select ARCH_HAS_PMEM_API		if X86_64
7417596731SRobin Murphy	select ARCH_HAS_PTE_DEVMAP		if X86_64
753010a5eaSLaurent Dufour	select ARCH_HAS_PTE_SPECIAL
760aed55afSDan Williams	select ARCH_HAS_UACCESS_FLUSHCACHE	if X86_64
77092b31aaSDan Williams	select ARCH_HAS_UACCESS_MCSAFE		if X86_64 && X86_MCE
78d2852a22SDaniel Borkmann	select ARCH_HAS_SET_MEMORY
79d253ca0cSRick Edgecombe	select ARCH_HAS_SET_DIRECT_MAP
80ad21fc4fSLaura Abbott	select ARCH_HAS_STRICT_KERNEL_RWX
81ad21fc4fSLaura Abbott	select ARCH_HAS_STRICT_MODULE_RWX
82ac1ab12aSMathieu Desnoyers	select ARCH_HAS_SYNC_CORE_BEFORE_USERMODE
83c6d30853SAndrey Ryabinin	select ARCH_HAS_UBSAN_SANITIZE_ALL
846471b825SIngo Molnar	select ARCH_HAVE_NMI_SAFE_CMPXCHG
856471b825SIngo Molnar	select ARCH_MIGHT_HAVE_ACPI_PDC		if ACPI
8677fbbc81SMark Salter	select ARCH_MIGHT_HAVE_PC_PARPORT
875e2c18c0SMark Salter	select ARCH_MIGHT_HAVE_PC_SERIO
883599fe12SThomas Gleixner	select ARCH_STACKWALK
892c870e61SArnd Bergmann	select ARCH_SUPPORTS_ACPI
906471b825SIngo Molnar	select ARCH_SUPPORTS_ATOMIC_RMW
916471b825SIngo Molnar	select ARCH_SUPPORTS_NUMA_BALANCING	if X86_64
926471b825SIngo Molnar	select ARCH_USE_BUILTIN_BSWAP
936471b825SIngo Molnar	select ARCH_USE_QUEUED_RWLOCKS
946471b825SIngo Molnar	select ARCH_USE_QUEUED_SPINLOCKS
95ce4a4e56SAndy Lutomirski	select ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH
96c763ea26SIngo Molnar	select ARCH_WANTS_DYNAMIC_TASK_STRUCT
973876d4a3SAlexandre Ghiti	select ARCH_WANT_HUGE_PMD_SHARE
9838d8b4e6SHuang Ying	select ARCH_WANTS_THP_SWAP		if X86_64
996471b825SIngo Molnar	select BUILDTIME_EXTABLE_SORT
1006471b825SIngo Molnar	select CLKEVT_I8253
1016471b825SIngo Molnar	select CLOCKSOURCE_VALIDATE_LAST_CYCLE
1026471b825SIngo Molnar	select CLOCKSOURCE_WATCHDOG
1036471b825SIngo Molnar	select DCACHE_WORD_ACCESS
10445471cd9SLinus Torvalds	select EDAC_ATOMIC_SCRUB
10545471cd9SLinus Torvalds	select EDAC_SUPPORT
1066471b825SIngo Molnar	select GENERIC_CLOCKEVENTS
1076471b825SIngo Molnar	select GENERIC_CLOCKEVENTS_BROADCAST	if X86_64 || (X86_32 && X86_LOCAL_APIC)
1086471b825SIngo Molnar	select GENERIC_CLOCKEVENTS_MIN_ADJUST
1096471b825SIngo Molnar	select GENERIC_CMOS_UPDATE
1106471b825SIngo Molnar	select GENERIC_CPU_AUTOPROBE
11161dc0f55SThomas Gleixner	select GENERIC_CPU_VULNERABILITIES
1126471b825SIngo Molnar	select GENERIC_EARLY_IOREMAP
1136471b825SIngo Molnar	select GENERIC_FIND_FIRST_BIT
1146471b825SIngo Molnar	select GENERIC_IOMAP
115c7d6c9ddSThomas Gleixner	select GENERIC_IRQ_EFFECTIVE_AFF_MASK	if SMP
1160fa115daSThomas Gleixner	select GENERIC_IRQ_MATRIX_ALLOCATOR	if X86_LOCAL_APIC
117ad7a929fSThomas Gleixner	select GENERIC_IRQ_MIGRATION		if SMP
1186471b825SIngo Molnar	select GENERIC_IRQ_PROBE
119c201c917SThomas Gleixner	select GENERIC_IRQ_RESERVATION_MODE
1206471b825SIngo Molnar	select GENERIC_IRQ_SHOW
1216471b825SIngo Molnar	select GENERIC_PENDING_IRQ		if SMP
1226471b825SIngo Molnar	select GENERIC_SMP_IDLE_THREAD
1236471b825SIngo Molnar	select GENERIC_STRNCPY_FROM_USER
1246471b825SIngo Molnar	select GENERIC_STRNLEN_USER
1256471b825SIngo Molnar	select GENERIC_TIME_VSYSCALL
1267ac87074SVincenzo Frascino	select GENERIC_GETTIMEOFDAY
12739656e83SChristoph Hellwig	select GUP_GET_PTE_LOW_HIGH		if X86_PAE
1287edaeb68SThomas Gleixner	select HARDLOCKUP_CHECK_TIMESTAMP	if X86_64
1296471b825SIngo Molnar	select HAVE_ACPI_APEI			if ACPI
1306471b825SIngo Molnar	select HAVE_ACPI_APEI_NMI		if ACPI
1316471b825SIngo Molnar	select HAVE_ALIGNED_STRUCT_PAGE		if SLUB
1326471b825SIngo Molnar	select HAVE_ARCH_AUDITSYSCALL
1336471b825SIngo Molnar	select HAVE_ARCH_HUGE_VMAP		if X86_64 || X86_PAE
1346471b825SIngo Molnar	select HAVE_ARCH_JUMP_LABEL
135b34006c4SArd Biesheuvel	select HAVE_ARCH_JUMP_LABEL_RELATIVE
136d17a1d97SAndrey Ryabinin	select HAVE_ARCH_KASAN			if X86_64
1370609ae01SDaniel Axtens	select HAVE_ARCH_KASAN_VMALLOC		if X86_64
1386471b825SIngo Molnar	select HAVE_ARCH_KGDB
1399e08f57dSDaniel Cashman	select HAVE_ARCH_MMAP_RND_BITS		if MMU
1409e08f57dSDaniel Cashman	select HAVE_ARCH_MMAP_RND_COMPAT_BITS	if MMU && COMPAT
1411b028f78SDmitry Safonov	select HAVE_ARCH_COMPAT_MMAP_BASES	if MMU && COMPAT
142271ca788SArd Biesheuvel	select HAVE_ARCH_PREL32_RELOCATIONS
1436471b825SIngo Molnar	select HAVE_ARCH_SECCOMP_FILTER
144f7d83c1cSKees Cook	select HAVE_ARCH_THREAD_STRUCT_WHITELIST
145afaef01cSAlexander Popov	select HAVE_ARCH_STACKLEAK
1466471b825SIngo Molnar	select HAVE_ARCH_TRACEHOOK
1476471b825SIngo Molnar	select HAVE_ARCH_TRANSPARENT_HUGEPAGE
148a00cc7d9SMatthew Wilcox	select HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD if X86_64
149e37e43a4SAndy Lutomirski	select HAVE_ARCH_VMAP_STACK		if X86_64
150c763ea26SIngo Molnar	select HAVE_ARCH_WITHIN_STACK_FRAMES
1512ff2b7ecSMasahiro Yamada	select HAVE_ASM_MODVERSIONS
1526471b825SIngo Molnar	select HAVE_CMPXCHG_DOUBLE
1536471b825SIngo Molnar	select HAVE_CMPXCHG_LOCAL
1546471b825SIngo Molnar	select HAVE_CONTEXT_TRACKING		if X86_64
155c1bd55f9SJosh Triplett	select HAVE_COPY_THREAD_TLS
1566471b825SIngo Molnar	select HAVE_C_RECORDMCOUNT
1576471b825SIngo Molnar	select HAVE_DEBUG_KMEMLEAK
1589c5a3621SAkinobu Mita	select HAVE_DMA_CONTIGUOUS
159677aa9f7SSteven Rostedt	select HAVE_DYNAMIC_FTRACE
16006aeaaeaSMasami Hiramatsu	select HAVE_DYNAMIC_FTRACE_WITH_REGS
161562955feSSteven Rostedt (VMware)	select HAVE_DYNAMIC_FTRACE_WITH_DIRECT_CALLS
16203f5781bSWang YanQing	select HAVE_EBPF_JIT
16358340a07SJohannes Berg	select HAVE_EFFICIENT_UNALIGNED_ACCESS
1646630a8e5SChristoph Hellwig	select HAVE_EISA
1655f56a5dfSJiri Slaby	select HAVE_EXIT_THREAD
16667a929e0SChristoph Hellwig	select HAVE_FAST_GUP
167644e0e8dSSteven Rostedt (VMware)	select HAVE_FENTRY			if X86_64 || DYNAMIC_FTRACE
1686471b825SIngo Molnar	select HAVE_FTRACE_MCOUNT_RECORD
1696471b825SIngo Molnar	select HAVE_FUNCTION_GRAPH_TRACER
1706471b825SIngo Molnar	select HAVE_FUNCTION_TRACER
1716b90bd4bSEmese Revfy	select HAVE_GCC_PLUGINS
1720067f129SK.Prasad	select HAVE_HW_BREAKPOINT
1736471b825SIngo Molnar	select HAVE_IDE
1746471b825SIngo Molnar	select HAVE_IOREMAP_PROT
1756471b825SIngo Molnar	select HAVE_IRQ_EXIT_ON_IRQ_STACK	if X86_64
1766471b825SIngo Molnar	select HAVE_IRQ_TIME_ACCOUNTING
1776471b825SIngo Molnar	select HAVE_KERNEL_BZIP2
1786471b825SIngo Molnar	select HAVE_KERNEL_GZIP
1796471b825SIngo Molnar	select HAVE_KERNEL_LZ4
1806471b825SIngo Molnar	select HAVE_KERNEL_LZMA
1816471b825SIngo Molnar	select HAVE_KERNEL_LZO
1826471b825SIngo Molnar	select HAVE_KERNEL_XZ
1836471b825SIngo Molnar	select HAVE_KPROBES
1846471b825SIngo Molnar	select HAVE_KPROBES_ON_FTRACE
185540adea3SMasami Hiramatsu	select HAVE_FUNCTION_ERROR_INJECTION
1866471b825SIngo Molnar	select HAVE_KRETPROBES
1876471b825SIngo Molnar	select HAVE_KVM
1886471b825SIngo Molnar	select HAVE_LIVEPATCH			if X86_64
1896471b825SIngo Molnar	select HAVE_MEMBLOCK_NODE_MAP
1900102752eSFrederic Weisbecker	select HAVE_MIXED_BREAKPOINTS_REGS
191ee9f8fceSJosh Poimboeuf	select HAVE_MOD_ARCH_SPECIFIC
1929f132f7eSJoel Fernandes (Google)	select HAVE_MOVE_PMD
19342a0bb3fSPetr Mladek	select HAVE_NMI
1946471b825SIngo Molnar	select HAVE_OPROFILE
1956471b825SIngo Molnar	select HAVE_OPTPROBES
1966471b825SIngo Molnar	select HAVE_PCSPKR_PLATFORM
1976471b825SIngo Molnar	select HAVE_PERF_EVENTS
198c01d4323SFrederic Weisbecker	select HAVE_PERF_EVENTS_NMI
19992e5aae4SNicholas Piggin	select HAVE_HARDLOCKUP_DETECTOR_PERF	if PERF_EVENTS && HAVE_PERF_EVENTS_NMI
200eb01d42aSChristoph Hellwig	select HAVE_PCI
201c5e63197SJiri Olsa	select HAVE_PERF_REGS
202c5ebcedbSJiri Olsa	select HAVE_PERF_USER_STACK_DUMP
20348a8b97cSPeter Zijlstra	select HAVE_RCU_TABLE_FREE		if PARAVIRT
2046471b825SIngo Molnar	select HAVE_REGS_AND_STACK_ACCESS_API
2056415b38bSJiri Slaby	select HAVE_RELIABLE_STACKTRACE		if X86_64 && (UNWINDER_FRAME_POINTER || UNWINDER_ORC) && STACK_VALIDATION
2063c88ee19SMasami Hiramatsu	select HAVE_FUNCTION_ARG_ACCESS_API
207d148eac0SMasahiro Yamada	select HAVE_STACKPROTECTOR		if CC_HAS_SANE_STACKPROTECTOR
208c763ea26SIngo Molnar	select HAVE_STACK_VALIDATION		if X86_64
209d6761b8fSMathieu Desnoyers	select HAVE_RSEQ
2106471b825SIngo Molnar	select HAVE_SYSCALL_TRACEPOINTS
2116471b825SIngo Molnar	select HAVE_UNSTABLE_SCHED_CLOCK
2127c68af6eSAvi Kivity	select HAVE_USER_RETURN_NOTIFIER
2137ac87074SVincenzo Frascino	select HAVE_GENERIC_VDSO
21405736e4aSThomas Gleixner	select HOTPLUG_SMT			if SMP
215c0185808SThomas Gleixner	select IRQ_FORCED_THREADING
21686596f0aSChristoph Hellwig	select NEED_SG_DMA_LENGTH
2172eac9c2dSChristoph Hellwig	select PCI_DOMAINS			if PCI
218625210cfSSinan Kaya	select PCI_LOCKLESS_CONFIG		if PCI
2196471b825SIngo Molnar	select PERF_EVENTS
2203195ef59SPrarit Bhargava	select RTC_LIB
221d6faca40SArnd Bergmann	select RTC_MC146818_LIB
2226471b825SIngo Molnar	select SPARSE_IRQ
22383fe27eaSPranith Kumar	select SRCU
2246471b825SIngo Molnar	select SYSCTL_EXCEPTION_TRACE
22515f4eae7SAndy Lutomirski	select THREAD_INFO_IN_TASK
2266471b825SIngo Molnar	select USER_STACKTRACE_SUPPORT
2276471b825SIngo Molnar	select VIRT_TO_BUS
2286471b825SIngo Molnar	select X86_FEATURE_NAMES		if PROC_FS
2290c608dadSAubrey Li	select PROC_PID_ARCH_STATUS		if PROC_FS
2307d8330a5SBalbir Singh
231ba7e4d13SIngo Molnarconfig INSTRUCTION_DECODER
2323120e25eSJan Beulich	def_bool y
2333120e25eSJan Beulich	depends on KPROBES || PERF_EVENTS || UPROBES
234ba7e4d13SIngo Molnar
23551b26adaSLinus Torvaldsconfig OUTPUT_FORMAT
23651b26adaSLinus Torvalds	string
23751b26adaSLinus Torvalds	default "elf32-i386" if X86_32
23851b26adaSLinus Torvalds	default "elf64-x86-64" if X86_64
23951b26adaSLinus Torvalds
24073531905SSam Ravnborgconfig ARCH_DEFCONFIG
241b9b39bfbSSam Ravnborg	string
24273531905SSam Ravnborg	default "arch/x86/configs/i386_defconfig" if X86_32
24373531905SSam Ravnborg	default "arch/x86/configs/x86_64_defconfig" if X86_64
244b9b39bfbSSam Ravnborg
2458d5fffb9SSam Ravnborgconfig LOCKDEP_SUPPORT
2463c2362e6SHarvey Harrison	def_bool y
2478d5fffb9SSam Ravnborg
2488d5fffb9SSam Ravnborgconfig STACKTRACE_SUPPORT
2493c2362e6SHarvey Harrison	def_bool y
2508d5fffb9SSam Ravnborg
2518d5fffb9SSam Ravnborgconfig MMU
2523c2362e6SHarvey Harrison	def_bool y
2538d5fffb9SSam Ravnborg
2549e08f57dSDaniel Cashmanconfig ARCH_MMAP_RND_BITS_MIN
2559e08f57dSDaniel Cashman	default 28 if 64BIT
2569e08f57dSDaniel Cashman	default 8
2579e08f57dSDaniel Cashman
2589e08f57dSDaniel Cashmanconfig ARCH_MMAP_RND_BITS_MAX
2599e08f57dSDaniel Cashman	default 32 if 64BIT
2609e08f57dSDaniel Cashman	default 16
2619e08f57dSDaniel Cashman
2629e08f57dSDaniel Cashmanconfig ARCH_MMAP_RND_COMPAT_BITS_MIN
2639e08f57dSDaniel Cashman	default 8
2649e08f57dSDaniel Cashman
2659e08f57dSDaniel Cashmanconfig ARCH_MMAP_RND_COMPAT_BITS_MAX
2669e08f57dSDaniel Cashman	default 16
2679e08f57dSDaniel Cashman
2688d5fffb9SSam Ravnborgconfig SBUS
2698d5fffb9SSam Ravnborg	bool
2708d5fffb9SSam Ravnborg
2718d5fffb9SSam Ravnborgconfig GENERIC_ISA_DMA
2723120e25eSJan Beulich	def_bool y
2733120e25eSJan Beulich	depends on ISA_DMA_API
2748d5fffb9SSam Ravnborg
2758d5fffb9SSam Ravnborgconfig GENERIC_BUG
2763c2362e6SHarvey Harrison	def_bool y
2778d5fffb9SSam Ravnborg	depends on BUG
278b93a531eSJan Beulich	select GENERIC_BUG_RELATIVE_POINTERS if X86_64
279b93a531eSJan Beulich
280b93a531eSJan Beulichconfig GENERIC_BUG_RELATIVE_POINTERS
281b93a531eSJan Beulich	bool
2828d5fffb9SSam Ravnborg
2838d5fffb9SSam Ravnborgconfig ARCH_MAY_HAVE_PC_FDC
2843120e25eSJan Beulich	def_bool y
2853120e25eSJan Beulich	depends on ISA_DMA_API
2868d5fffb9SSam Ravnborg
2871032c0baSSam Ravnborgconfig GENERIC_CALIBRATE_DELAY
2881032c0baSSam Ravnborg	def_bool y
2891032c0baSSam Ravnborg
2909a0b8415Svenkatesh.pallipadi@intel.comconfig ARCH_HAS_CPU_RELAX
2919a0b8415Svenkatesh.pallipadi@intel.com	def_bool y
2928d5fffb9SSam Ravnborg
2931b27d05bSPekka Enbergconfig ARCH_HAS_CACHE_LINE_SIZE
2941b27d05bSPekka Enberg	def_bool y
2951b27d05bSPekka Enberg
296316d097cSDave Hansenconfig ARCH_HAS_FILTER_PGPROT
297316d097cSDave Hansen	def_bool y
298316d097cSDave Hansen
299dd5af90aSMike Travisconfig HAVE_SETUP_PER_CPU_AREA
30089c9c4c5SBrian Gerst	def_bool y
301b32ef636Stravis@sgi.com
30208fc4580STejun Heoconfig NEED_PER_CPU_EMBED_FIRST_CHUNK
30308fc4580STejun Heo	def_bool y
30408fc4580STejun Heo
30508fc4580STejun Heoconfig NEED_PER_CPU_PAGE_FIRST_CHUNK
30611124411STejun Heo	def_bool y
30711124411STejun Heo
308801e4062SJohannes Bergconfig ARCH_HIBERNATION_POSSIBLE
309801e4062SJohannes Berg	def_bool y
310801e4062SJohannes Berg
311f4cb5700SJohannes Bergconfig ARCH_SUSPEND_POSSIBLE
312f4cb5700SJohannes Berg	def_bool y
313f4cb5700SJohannes Berg
31453313b2cSSteve Capperconfig ARCH_WANT_GENERAL_HUGETLB
31553313b2cSSteve Capper	def_bool y
31653313b2cSSteve Capper
3178d5fffb9SSam Ravnborgconfig ZONE_DMA32
318e0fd24a3SJan Beulich	def_bool y if X86_64
3198d5fffb9SSam Ravnborg
3208d5fffb9SSam Ravnborgconfig AUDIT_ARCH
321e0fd24a3SJan Beulich	def_bool y if X86_64
3228d5fffb9SSam Ravnborg
3236a11f75bSAkinobu Mitaconfig ARCH_SUPPORTS_DEBUG_PAGEALLOC
3246a11f75bSAkinobu Mita	def_bool y
3256a11f75bSAkinobu Mita
326d6f2d75aSAndrey Ryabininconfig KASAN_SHADOW_OFFSET
327d6f2d75aSAndrey Ryabinin	hex
328d6f2d75aSAndrey Ryabinin	depends on KASAN
329d6f2d75aSAndrey Ryabinin	default 0xdffffc0000000000
330d6f2d75aSAndrey Ryabinin
33169575d38SShane Wangconfig HAVE_INTEL_TXT
33269575d38SShane Wang	def_bool y
3336ea30386SKees Cook	depends on INTEL_IOMMU && ACPI
33469575d38SShane Wang
3356b0c3d44SSam Ravnborgconfig X86_32_SMP
3366b0c3d44SSam Ravnborg	def_bool y
3376b0c3d44SSam Ravnborg	depends on X86_32 && SMP
3386b0c3d44SSam Ravnborg
3396b0c3d44SSam Ravnborgconfig X86_64_SMP
3406b0c3d44SSam Ravnborg	def_bool y
3416b0c3d44SSam Ravnborg	depends on X86_64 && SMP
3426b0c3d44SSam Ravnborg
343ccbeed3aSTejun Heoconfig X86_32_LAZY_GS
344ccbeed3aSTejun Heo	def_bool y
3458458f8c2SMasahiro Yamada	depends on X86_32 && !STACKPROTECTOR
346ccbeed3aSTejun Heo
3472b144498SSrikar Dronamrajuconfig ARCH_SUPPORTS_UPROBES
3482b144498SSrikar Dronamraju	def_bool y
3492b144498SSrikar Dronamraju
350d20642f0SRob Herringconfig FIX_EARLYCON_MEM
351d20642f0SRob Herring	def_bool y
352d20642f0SRob Herring
35394d49eb3SKirill A. Shutemovconfig DYNAMIC_PHYSICAL_MASK
35494d49eb3SKirill A. Shutemov	bool
35594d49eb3SKirill A. Shutemov
35698233368SKirill A. Shutemovconfig PGTABLE_LEVELS
35798233368SKirill A. Shutemov	int
35877ef56e4SKirill A. Shutemov	default 5 if X86_5LEVEL
35998233368SKirill A. Shutemov	default 4 if X86_64
36098233368SKirill A. Shutemov	default 3 if X86_PAE
36198233368SKirill A. Shutemov	default 2
36298233368SKirill A. Shutemov
3632a61f474SMasahiro Yamadaconfig CC_HAS_SANE_STACKPROTECTOR
3642a61f474SMasahiro Yamada	bool
3652a61f474SMasahiro Yamada	default $(success,$(srctree)/scripts/gcc-x86_64-has-stack-protector.sh $(CC)) if 64BIT
3662a61f474SMasahiro Yamada	default $(success,$(srctree)/scripts/gcc-x86_32-has-stack-protector.sh $(CC))
3672a61f474SMasahiro Yamada	help
3682a61f474SMasahiro Yamada	   We have to make sure stack protector is unconditionally disabled if
3692a61f474SMasahiro Yamada	   the compiler produces broken code.
3702a61f474SMasahiro Yamada
371506f1d07SSam Ravnborgmenu "Processor type and features"
372506f1d07SSam Ravnborg
3735ee71535SRandy Dunlapconfig ZONE_DMA
3745ee71535SRandy Dunlap	bool "DMA memory allocation support" if EXPERT
3755ee71535SRandy Dunlap	default y
3765ee71535SRandy Dunlap	help
3775ee71535SRandy Dunlap	  DMA memory allocation support allows devices with less than 32-bit
3785ee71535SRandy Dunlap	  addressing to allocate within the first 16MB of address space.
3795ee71535SRandy Dunlap	  Disable if no such devices will be used.
3805ee71535SRandy Dunlap
3815ee71535SRandy Dunlap	  If unsure, say Y.
3825ee71535SRandy Dunlap
383506f1d07SSam Ravnborgconfig SMP
384506f1d07SSam Ravnborg	bool "Symmetric multi-processing support"
385506f1d07SSam Ravnborg	---help---
386506f1d07SSam Ravnborg	  This enables support for systems with more than one CPU. If you have
3874a474157SRobert Graffham	  a system with only one CPU, say N. If you have a system with more
3884a474157SRobert Graffham	  than one CPU, say Y.
389506f1d07SSam Ravnborg
3904a474157SRobert Graffham	  If you say N here, the kernel will run on uni- and multiprocessor
391506f1d07SSam Ravnborg	  machines, but will use only one CPU of a multiprocessor machine. If
392506f1d07SSam Ravnborg	  you say Y here, the kernel will run on many, but not all,
3934a474157SRobert Graffham	  uniprocessor machines. On a uniprocessor machine, the kernel
394506f1d07SSam Ravnborg	  will run faster if you say N here.
395506f1d07SSam Ravnborg
396506f1d07SSam Ravnborg	  Note that if you say Y here and choose architecture "586" or
397506f1d07SSam Ravnborg	  "Pentium" under "Processor family", the kernel will not work on 486
398506f1d07SSam Ravnborg	  architectures. Similarly, multiprocessor kernels for the "PPro"
399506f1d07SSam Ravnborg	  architecture may not work on all Pentium based boards.
400506f1d07SSam Ravnborg
401506f1d07SSam Ravnborg	  People using multiprocessor machines who say Y here should also say
402506f1d07SSam Ravnborg	  Y to "Enhanced Real Time Clock Support", below. The "Advanced Power
403506f1d07SSam Ravnborg	  Management" code will be disabled if you say Y here.
404506f1d07SSam Ravnborg
405cb1aaebeSMauro Carvalho Chehab	  See also <file:Documentation/x86/i386/IO-APIC.rst>,
4064f4cfa6cSMauro Carvalho Chehab	  <file:Documentation/admin-guide/lockup-watchdogs.rst> and the SMP-HOWTO available at
407506f1d07SSam Ravnborg	  <http://www.tldp.org/docs.html#howto>.
408506f1d07SSam Ravnborg
409506f1d07SSam Ravnborg	  If you don't know what to do here, say N.
410506f1d07SSam Ravnborg
4119def39beSJosh Triplettconfig X86_FEATURE_NAMES
4129def39beSJosh Triplett	bool "Processor feature human-readable names" if EMBEDDED
4139def39beSJosh Triplett	default y
4149def39beSJosh Triplett	---help---
4159def39beSJosh Triplett	  This option compiles in a table of x86 feature bits and corresponding
4169def39beSJosh Triplett	  names.  This is required to support /proc/cpuinfo and a few kernel
4179def39beSJosh Triplett	  messages.  You can disable this to save space, at the expense of
4189def39beSJosh Triplett	  making those few kernel messages show numeric feature bits instead.
4199def39beSJosh Triplett
4209def39beSJosh Triplett	  If in doubt, say Y.
4219def39beSJosh Triplett
42206cd9a7dSYinghai Luconfig X86_X2APIC
42306cd9a7dSYinghai Lu	bool "Support x2apic"
42419e3d60dSJan Kiszka	depends on X86_LOCAL_APIC && X86_64 && (IRQ_REMAP || HYPERVISOR_GUEST)
42506cd9a7dSYinghai Lu	---help---
42606cd9a7dSYinghai Lu	  This enables x2apic support on CPUs that have this feature.
42706cd9a7dSYinghai Lu
42806cd9a7dSYinghai Lu	  This allows 32-bit apic IDs (so it can support very large systems),
42906cd9a7dSYinghai Lu	  and accesses the local apic via MSRs not via mmio.
43006cd9a7dSYinghai Lu
43106cd9a7dSYinghai Lu	  If you don't know what to do here, say N.
43206cd9a7dSYinghai Lu
4336695c85bSYinghai Luconfig X86_MPPARSE
4346e87f9b7SBin Gao	bool "Enable MPS table" if ACPI || SFI
4357a527688SJan Beulich	default y
4365ab74722SIngo Molnar	depends on X86_LOCAL_APIC
4378f9ca475SIngo Molnar	---help---
4386695c85bSYinghai Lu	  For old smp systems that do not have proper acpi support. Newer systems
4396695c85bSYinghai Lu	  (esp with 64bit cpus) with acpi support, MADT and DSDT will override it
4406695c85bSYinghai Lu
441ddd70cf9SJun Nakajimaconfig GOLDFISH
442ddd70cf9SJun Nakajima       def_bool y
443ddd70cf9SJun Nakajima       depends on X86_GOLDFISH
444ddd70cf9SJun Nakajima
44576b04384SDavid Woodhouseconfig RETPOLINE
44676b04384SDavid Woodhouse	bool "Avoid speculative indirect branches in kernel"
44776b04384SDavid Woodhouse	default y
448d5028ba8SPeter Zijlstra	select STACK_VALIDATION if HAVE_STACK_VALIDATION
44976b04384SDavid Woodhouse	help
45076b04384SDavid Woodhouse	  Compile kernel with the retpoline compiler options to guard against
45176b04384SDavid Woodhouse	  kernel-to-user data leaks by avoiding speculative indirect
45276b04384SDavid Woodhouse	  branches. Requires a compiler with -mindirect-branch=thunk-extern
45376b04384SDavid Woodhouse	  support for full protection. The kernel may run slower.
45476b04384SDavid Woodhouse
455e6d42931SJohannes Weinerconfig X86_CPU_RESCTRL
456e6d42931SJohannes Weiner	bool "x86 CPU resource control support"
4576fe07ce3SBabu Moger	depends on X86 && (CPU_SUP_INTEL || CPU_SUP_AMD)
45859fe5a77SThomas Gleixner	select KERNFS
459*e79f15a4SChen Yu	select PROC_CPU_RESCTRL		if PROC_FS
46078e99b4aSFenghua Yu	help
461e6d42931SJohannes Weiner	  Enable x86 CPU resource control support.
4626fe07ce3SBabu Moger
4636fe07ce3SBabu Moger	  Provide support for the allocation and monitoring of system resources
4646fe07ce3SBabu Moger	  usage by the CPU.
4656fe07ce3SBabu Moger
4666fe07ce3SBabu Moger	  Intel calls this Intel Resource Director Technology
4676fe07ce3SBabu Moger	  (Intel(R) RDT). More information about RDT can be found in the
4686fe07ce3SBabu Moger	  Intel x86 Architecture Software Developer Manual.
4696fe07ce3SBabu Moger
4706fe07ce3SBabu Moger	  AMD calls this AMD Platform Quality of Service (AMD QoS).
4716fe07ce3SBabu Moger	  More information about AMD QoS can be found in the AMD64 Technology
4726fe07ce3SBabu Moger	  Platform Quality of Service Extensions manual.
47378e99b4aSFenghua Yu
47478e99b4aSFenghua Yu	  Say N if unsure.
47578e99b4aSFenghua Yu
4768425091fSRavikiran G Thirumalaiif X86_32
477a0d0bb4dSRandy Dunlapconfig X86_BIGSMP
478a0d0bb4dSRandy Dunlap	bool "Support for big SMP systems with more than 8 CPUs"
479a0d0bb4dSRandy Dunlap	depends on SMP
480a0d0bb4dSRandy Dunlap	---help---
481a0d0bb4dSRandy Dunlap	  This option is needed for the systems that have more than 8 CPUs
482a0d0bb4dSRandy Dunlap
483c5c606d9SRavikiran G Thirumalaiconfig X86_EXTENDED_PLATFORM
484c5c606d9SRavikiran G Thirumalai	bool "Support for extended (non-PC) x86 platforms"
485c5c606d9SRavikiran G Thirumalai	default y
4868f9ca475SIngo Molnar	---help---
48706ac8346SIngo Molnar	  If you disable this option then the kernel will only support
48806ac8346SIngo Molnar	  standard PC platforms. (which covers the vast majority of
48906ac8346SIngo Molnar	  systems out there.)
49006ac8346SIngo Molnar
4918425091fSRavikiran G Thirumalai	  If you enable this option then you'll be able to select support
4928425091fSRavikiran G Thirumalai	  for the following (non-PC) 32 bit x86 platforms:
493cb7b8023SBen Hutchings		Goldfish (Android emulator)
4948425091fSRavikiran G Thirumalai		AMD Elan
4958425091fSRavikiran G Thirumalai		RDC R-321x SoC
4968425091fSRavikiran G Thirumalai		SGI 320/540 (Visual Workstation)
49783125a3aSAlessandro Rubini		STA2X11-based (e.g. Northville)
4983f4110a4SThomas Gleixner		Moorestown MID devices
49906ac8346SIngo Molnar
50006ac8346SIngo Molnar	  If you have one of these systems, or if you want to build a
50106ac8346SIngo Molnar	  generic distribution kernel, say Y here - otherwise say N.
5028425091fSRavikiran G Thirumalaiendif
50306ac8346SIngo Molnar
5048425091fSRavikiran G Thirumalaiif X86_64
5058425091fSRavikiran G Thirumalaiconfig X86_EXTENDED_PLATFORM
5068425091fSRavikiran G Thirumalai	bool "Support for extended (non-PC) x86 platforms"
5078425091fSRavikiran G Thirumalai	default y
5088425091fSRavikiran G Thirumalai	---help---
5098425091fSRavikiran G Thirumalai	  If you disable this option then the kernel will only support
5108425091fSRavikiran G Thirumalai	  standard PC platforms. (which covers the vast majority of
5118425091fSRavikiran G Thirumalai	  systems out there.)
5128425091fSRavikiran G Thirumalai
5138425091fSRavikiran G Thirumalai	  If you enable this option then you'll be able to select support
5148425091fSRavikiran G Thirumalai	  for the following (non-PC) 64 bit x86 platforms:
51544b111b5SSteffen Persvold		Numascale NumaChip
5168425091fSRavikiran G Thirumalai		ScaleMP vSMP
5178425091fSRavikiran G Thirumalai		SGI Ultraviolet
5188425091fSRavikiran G Thirumalai
5198425091fSRavikiran G Thirumalai	  If you have one of these systems, or if you want to build a
5208425091fSRavikiran G Thirumalai	  generic distribution kernel, say Y here - otherwise say N.
5218425091fSRavikiran G Thirumalaiendif
522c5c606d9SRavikiran G Thirumalai# This is an alphabetically sorted list of 64 bit extended platforms
523c5c606d9SRavikiran G Thirumalai# Please maintain the alphabetic order if and when there are additions
52444b111b5SSteffen Persvoldconfig X86_NUMACHIP
52544b111b5SSteffen Persvold	bool "Numascale NumaChip"
52644b111b5SSteffen Persvold	depends on X86_64
52744b111b5SSteffen Persvold	depends on X86_EXTENDED_PLATFORM
52844b111b5SSteffen Persvold	depends on NUMA
52944b111b5SSteffen Persvold	depends on SMP
53044b111b5SSteffen Persvold	depends on X86_X2APIC
531f9726bfdSDaniel J Blueman	depends on PCI_MMCONFIG
53244b111b5SSteffen Persvold	---help---
53344b111b5SSteffen Persvold	  Adds support for Numascale NumaChip large-SMP systems. Needed to
53444b111b5SSteffen Persvold	  enable more than ~168 cores.
53544b111b5SSteffen Persvold	  If you don't have one of these, you should say N here.
53603b48632SNick Piggin
5376a48565eSIngo Molnarconfig X86_VSMP
538c5c606d9SRavikiran G Thirumalai	bool "ScaleMP vSMP"
5396276a074SBorislav Petkov	select HYPERVISOR_GUEST
5406a48565eSIngo Molnar	select PARAVIRT
5416a48565eSIngo Molnar	depends on X86_64 && PCI
542c5c606d9SRavikiran G Thirumalai	depends on X86_EXTENDED_PLATFORM
543ead91d4bSShai Fultheim	depends on SMP
5448f9ca475SIngo Molnar	---help---
5456a48565eSIngo Molnar	  Support for ScaleMP vSMP systems.  Say 'Y' here if this kernel is
5466a48565eSIngo Molnar	  supposed to run on these EM64T-based machines.  Only choose this option
5476a48565eSIngo Molnar	  if you have one of these machines.
5486a48565eSIngo Molnar
549c5c606d9SRavikiran G Thirumalaiconfig X86_UV
550c5c606d9SRavikiran G Thirumalai	bool "SGI Ultraviolet"
551c5c606d9SRavikiran G Thirumalai	depends on X86_64
552c5c606d9SRavikiran G Thirumalai	depends on X86_EXTENDED_PLATFORM
55354c28d29SJack Steiner	depends on NUMA
5541ecb4ae5SAndrew Morton	depends on EFI
5559d6c26e7SSuresh Siddha	depends on X86_X2APIC
5561222e564SIngo Molnar	depends on PCI
557c5c606d9SRavikiran G Thirumalai	---help---
558c5c606d9SRavikiran G Thirumalai	  This option is needed in order to support SGI Ultraviolet systems.
559c5c606d9SRavikiran G Thirumalai	  If you don't have one of these, you should say N here.
560c5c606d9SRavikiran G Thirumalai
561c5c606d9SRavikiran G Thirumalai# Following is an alphabetically sorted list of 32 bit extended platforms
562c5c606d9SRavikiran G Thirumalai# Please maintain the alphabetic order if and when there are additions
563506f1d07SSam Ravnborg
564ddd70cf9SJun Nakajimaconfig X86_GOLDFISH
565ddd70cf9SJun Nakajima       bool "Goldfish (Virtual Platform)"
566cb7b8023SBen Hutchings       depends on X86_EXTENDED_PLATFORM
567ddd70cf9SJun Nakajima       ---help---
568ddd70cf9SJun Nakajima	 Enable support for the Goldfish virtual platform used primarily
569ddd70cf9SJun Nakajima	 for Android development. Unless you are building for the Android
570ddd70cf9SJun Nakajima	 Goldfish emulator say N here.
571ddd70cf9SJun Nakajima
572c751e17bSThomas Gleixnerconfig X86_INTEL_CE
573c751e17bSThomas Gleixner	bool "CE4100 TV platform"
574c751e17bSThomas Gleixner	depends on PCI
575c751e17bSThomas Gleixner	depends on PCI_GODIRECT
5766084a6e2SJiang Liu	depends on X86_IO_APIC
577c751e17bSThomas Gleixner	depends on X86_32
578c751e17bSThomas Gleixner	depends on X86_EXTENDED_PLATFORM
57937bc9f50SDirk Brandewie	select X86_REBOOTFIXUPS
580da6b737bSSebastian Andrzej Siewior	select OF
581da6b737bSSebastian Andrzej Siewior	select OF_EARLY_FLATTREE
582c751e17bSThomas Gleixner	---help---
583c751e17bSThomas Gleixner	  Select for the Intel CE media processor (CE4100) SOC.
584c751e17bSThomas Gleixner	  This option compiles in support for the CE4100 SOC for settop
585c751e17bSThomas Gleixner	  boxes and media devices.
586c751e17bSThomas Gleixner
5874cb9b00fSDavid Cohenconfig X86_INTEL_MID
58843605ef1SAlan Cox	bool "Intel MID platform support"
58943605ef1SAlan Cox	depends on X86_EXTENDED_PLATFORM
590edc6bc78SDavid Cohen	depends on X86_PLATFORM_DEVICES
5911ea7c673SAlan Cox	depends on PCI
5923fda5bb4SAndy Shevchenko	depends on X86_64 || (PCI_GOANY && X86_32)
5931ea7c673SAlan Cox	depends on X86_IO_APIC
5947c9c3a1eSAlan Cox	select SFI
5954cb9b00fSDavid Cohen	select I2C
5967c9c3a1eSAlan Cox	select DW_APB_TIMER
5971ea7c673SAlan Cox	select APB_TIMER
5981ea7c673SAlan Cox	select INTEL_SCU_IPC
59915a713dfSMika Westerberg	select MFD_INTEL_MSIC
6001ea7c673SAlan Cox	---help---
6014cb9b00fSDavid Cohen	  Select to build a kernel capable of supporting Intel MID (Mobile
6024cb9b00fSDavid Cohen	  Internet Device) platform systems which do not have the PCI legacy
6034cb9b00fSDavid Cohen	  interfaces. If you are building for a PC class system say N here.
6041ea7c673SAlan Cox
6054cb9b00fSDavid Cohen	  Intel MID platforms are based on an Intel processor and chipset which
6064cb9b00fSDavid Cohen	  consume less power than most of the x86 derivatives.
60743605ef1SAlan Cox
6088bbc2a13SBryan O'Donoghueconfig X86_INTEL_QUARK
6098bbc2a13SBryan O'Donoghue	bool "Intel Quark platform support"
6108bbc2a13SBryan O'Donoghue	depends on X86_32
6118bbc2a13SBryan O'Donoghue	depends on X86_EXTENDED_PLATFORM
6128bbc2a13SBryan O'Donoghue	depends on X86_PLATFORM_DEVICES
6138bbc2a13SBryan O'Donoghue	depends on X86_TSC
6148bbc2a13SBryan O'Donoghue	depends on PCI
6158bbc2a13SBryan O'Donoghue	depends on PCI_GOANY
6168bbc2a13SBryan O'Donoghue	depends on X86_IO_APIC
6178bbc2a13SBryan O'Donoghue	select IOSF_MBI
6188bbc2a13SBryan O'Donoghue	select INTEL_IMR
6199ab6eb51SAndy Shevchenko	select COMMON_CLK
6208bbc2a13SBryan O'Donoghue	---help---
6218bbc2a13SBryan O'Donoghue	  Select to include support for Quark X1000 SoC.
6228bbc2a13SBryan O'Donoghue	  Say Y here if you have a Quark based system such as the Arduino
6238bbc2a13SBryan O'Donoghue	  compatible Intel Galileo.
6248bbc2a13SBryan O'Donoghue
6253d48aab1SMika Westerbergconfig X86_INTEL_LPSS
6263d48aab1SMika Westerberg	bool "Intel Low Power Subsystem Support"
6275962dd22SSinan Kaya	depends on X86 && ACPI && PCI
6283d48aab1SMika Westerberg	select COMMON_CLK
6290f531431SMathias Nyman	select PINCTRL
630eebb3e8dSAndy Shevchenko	select IOSF_MBI
6313d48aab1SMika Westerberg	---help---
6323d48aab1SMika Westerberg	  Select to build support for Intel Low Power Subsystem such as
6333d48aab1SMika Westerberg	  found on Intel Lynxpoint PCH. Selecting this option enables
6340f531431SMathias Nyman	  things like clock tree (common clock framework) and pincontrol
6350f531431SMathias Nyman	  which are needed by the LPSS peripheral drivers.
6363d48aab1SMika Westerberg
63792082a88SKen Xueconfig X86_AMD_PLATFORM_DEVICE
63892082a88SKen Xue	bool "AMD ACPI2Platform devices support"
63992082a88SKen Xue	depends on ACPI
64092082a88SKen Xue	select COMMON_CLK
64192082a88SKen Xue	select PINCTRL
64292082a88SKen Xue	---help---
64392082a88SKen Xue	  Select to interpret AMD specific ACPI device to platform device
64492082a88SKen Xue	  such as I2C, UART, GPIO found on AMD Carrizo and later chipsets.
64592082a88SKen Xue	  I2C and UART depend on COMMON_CLK to set clock. GPIO driver is
64692082a88SKen Xue	  implemented under PINCTRL subsystem.
64792082a88SKen Xue
648ced3ce76SDavid E. Boxconfig IOSF_MBI
649ced3ce76SDavid E. Box	tristate "Intel SoC IOSF Sideband support for SoC platforms"
650ced3ce76SDavid E. Box	depends on PCI
651ced3ce76SDavid E. Box	---help---
652ced3ce76SDavid E. Box	  This option enables sideband register access support for Intel SoC
653ced3ce76SDavid E. Box	  platforms. On these platforms the IOSF sideband is used in lieu of
654ced3ce76SDavid E. Box	  MSR's for some register accesses, mostly but not limited to thermal
655ced3ce76SDavid E. Box	  and power. Drivers may query the availability of this device to
656ced3ce76SDavid E. Box	  determine if they need the sideband in order to work on these
657ced3ce76SDavid E. Box	  platforms. The sideband is available on the following SoC products.
658ced3ce76SDavid E. Box	  This list is not meant to be exclusive.
659ced3ce76SDavid E. Box	   - BayTrail
660ced3ce76SDavid E. Box	   - Braswell
661ced3ce76SDavid E. Box	   - Quark
662ced3ce76SDavid E. Box
663ced3ce76SDavid E. Box	  You should say Y if you are running a kernel on one of these SoC's.
664ced3ce76SDavid E. Box
665ed2226bdSDavid E. Boxconfig IOSF_MBI_DEBUG
666ed2226bdSDavid E. Box	bool "Enable IOSF sideband access through debugfs"
667ed2226bdSDavid E. Box	depends on IOSF_MBI && DEBUG_FS
668ed2226bdSDavid E. Box	---help---
669ed2226bdSDavid E. Box	  Select this option to expose the IOSF sideband access registers (MCR,
670ed2226bdSDavid E. Box	  MDR, MCRX) through debugfs to write and read register information from
671ed2226bdSDavid E. Box	  different units on the SoC. This is most useful for obtaining device
672ed2226bdSDavid E. Box	  state information for debug and analysis. As this is a general access
673ed2226bdSDavid E. Box	  mechanism, users of this option would have specific knowledge of the
674ed2226bdSDavid E. Box	  device they want to access.
675ed2226bdSDavid E. Box
676ed2226bdSDavid E. Box	  If you don't require the option or are in doubt, say N.
677ed2226bdSDavid E. Box
678c5c606d9SRavikiran G Thirumalaiconfig X86_RDC321X
679c5c606d9SRavikiran G Thirumalai	bool "RDC R-321x SoC"
680506f1d07SSam Ravnborg	depends on X86_32
681c5c606d9SRavikiran G Thirumalai	depends on X86_EXTENDED_PLATFORM
682c5c606d9SRavikiran G Thirumalai	select M486
683c5c606d9SRavikiran G Thirumalai	select X86_REBOOTFIXUPS
684c5c606d9SRavikiran G Thirumalai	---help---
685c5c606d9SRavikiran G Thirumalai	  This option is needed for RDC R-321x system-on-chip, also known
686c5c606d9SRavikiran G Thirumalai	  as R-8610-(G).
687c5c606d9SRavikiran G Thirumalai	  If you don't have one of these chips, you should say N here.
688c5c606d9SRavikiran G Thirumalai
689e0c7ae37SIngo Molnarconfig X86_32_NON_STANDARD
6909c398017SIngo Molnar	bool "Support non-standard 32-bit SMP architectures"
6919c398017SIngo Molnar	depends on X86_32 && SMP
692c5c606d9SRavikiran G Thirumalai	depends on X86_EXTENDED_PLATFORM
6938f9ca475SIngo Molnar	---help---
694b5660ba7SH. Peter Anvin	  This option compiles in the bigsmp and STA2X11 default
695b5660ba7SH. Peter Anvin	  subarchitectures.  It is intended for a generic binary
696b5660ba7SH. Peter Anvin	  kernel. If you select them all, kernel will probe it one by
697b5660ba7SH. Peter Anvin	  one and will fallback to default.
698d49c4288SYinghai Lu
699c5c606d9SRavikiran G Thirumalai# Alphabetically sorted list of Non standard 32 bit platforms
700d49c4288SYinghai Lu
701d949f36fSLinus Torvaldsconfig X86_SUPPORTS_MEMORY_FAILURE
7026fc108a0SJan Beulich	def_bool y
703d949f36fSLinus Torvalds	# MCE code calls memory_failure():
704d949f36fSLinus Torvalds	depends on X86_MCE
705d949f36fSLinus Torvalds	# On 32-bit this adds too big of NODES_SHIFT and we run out of page flags:
706d949f36fSLinus Torvalds	# On 32-bit SPARSEMEM adds too big of SECTIONS_WIDTH:
707d949f36fSLinus Torvalds	depends on X86_64 || !SPARSEMEM
708d949f36fSLinus Torvalds	select ARCH_SUPPORTS_MEMORY_FAILURE
709d949f36fSLinus Torvalds
71083125a3aSAlessandro Rubiniconfig STA2X11
71183125a3aSAlessandro Rubini	bool "STA2X11 Companion Chip Support"
71283125a3aSAlessandro Rubini	depends on X86_32_NON_STANDARD && PCI
71383125a3aSAlessandro Rubini	select SWIOTLB
71483125a3aSAlessandro Rubini	select MFD_STA2X11
7150145071bSLinus Walleij	select GPIOLIB
71683125a3aSAlessandro Rubini	---help---
71783125a3aSAlessandro Rubini	  This adds support for boards based on the STA2X11 IO-Hub,
71883125a3aSAlessandro Rubini	  a.k.a. "ConneXt". The chip is used in place of the standard
71983125a3aSAlessandro Rubini	  PC chipset, so all "standard" peripherals are missing. If this
72083125a3aSAlessandro Rubini	  option is selected the kernel will still be able to boot on
72183125a3aSAlessandro Rubini	  standard PC machines.
72283125a3aSAlessandro Rubini
72382148d1dSShérabconfig X86_32_IRIS
72482148d1dSShérab	tristate "Eurobraille/Iris poweroff module"
72582148d1dSShérab	depends on X86_32
72682148d1dSShérab	---help---
72782148d1dSShérab	  The Iris machines from EuroBraille do not have APM or ACPI support
72882148d1dSShérab	  to shut themselves down properly.  A special I/O sequence is
72982148d1dSShérab	  needed to do so, which is what this module does at
73082148d1dSShérab	  kernel shutdown.
73182148d1dSShérab
73282148d1dSShérab	  This is only for Iris machines from EuroBraille.
73382148d1dSShérab
73482148d1dSShérab	  If unused, say N.
73582148d1dSShérab
736ae1e9130SIngo Molnarconfig SCHED_OMIT_FRAME_POINTER
7373c2362e6SHarvey Harrison	def_bool y
7383c2362e6SHarvey Harrison	prompt "Single-depth WCHAN output"
739a87d0914SKen Chen	depends on X86
7408f9ca475SIngo Molnar	---help---
741506f1d07SSam Ravnborg	  Calculate simpler /proc/<PID>/wchan values. If this option
742506f1d07SSam Ravnborg	  is disabled then wchan values will recurse back to the
743506f1d07SSam Ravnborg	  caller function. This provides more accurate wchan values,
744506f1d07SSam Ravnborg	  at the expense of slightly more scheduling overhead.
745506f1d07SSam Ravnborg
746506f1d07SSam Ravnborg	  If in doubt, say "Y".
747506f1d07SSam Ravnborg
7486276a074SBorislav Petkovmenuconfig HYPERVISOR_GUEST
7496276a074SBorislav Petkov	bool "Linux guest support"
7508f9ca475SIngo Molnar	---help---
7516276a074SBorislav Petkov	  Say Y here to enable options for running Linux under various hyper-
7526276a074SBorislav Petkov	  visors. This option enables basic hypervisor detection and platform
7536276a074SBorislav Petkov	  setup.
754506f1d07SSam Ravnborg
7556276a074SBorislav Petkov	  If you say N, all options in this submenu will be skipped and
7566276a074SBorislav Petkov	  disabled, and Linux guest support won't be built in.
757506f1d07SSam Ravnborg
7586276a074SBorislav Petkovif HYPERVISOR_GUEST
759506f1d07SSam Ravnborg
760e61bd94aSEduardo Pereira Habkostconfig PARAVIRT
761e61bd94aSEduardo Pereira Habkost	bool "Enable paravirtualization code"
7628f9ca475SIngo Molnar	---help---
763e61bd94aSEduardo Pereira Habkost	  This changes the kernel so it can modify itself when it is run
764e61bd94aSEduardo Pereira Habkost	  under a hypervisor, potentially improving performance significantly
765e61bd94aSEduardo Pereira Habkost	  over full virtualization.  However, when run without a hypervisor
766e61bd94aSEduardo Pereira Habkost	  the kernel is theoretically slower and slightly larger.
767e61bd94aSEduardo Pereira Habkost
768c00a280aSJuergen Grossconfig PARAVIRT_XXL
769c00a280aSJuergen Gross	bool
770c00a280aSJuergen Gross
7716276a074SBorislav Petkovconfig PARAVIRT_DEBUG
7726276a074SBorislav Petkov	bool "paravirt-ops debugging"
7736276a074SBorislav Petkov	depends on PARAVIRT && DEBUG_KERNEL
7746276a074SBorislav Petkov	---help---
7756276a074SBorislav Petkov	  Enable to debug paravirt_ops internals.  Specifically, BUG if
7766276a074SBorislav Petkov	  a paravirt_op is missing when it is called.
7776276a074SBorislav Petkov
778b4ecc126SJeremy Fitzhardingeconfig PARAVIRT_SPINLOCKS
779b4ecc126SJeremy Fitzhardinge	bool "Paravirtualization layer for spinlocks"
7806ea30386SKees Cook	depends on PARAVIRT && SMP
781b4ecc126SJeremy Fitzhardinge	---help---
782b4ecc126SJeremy Fitzhardinge	  Paravirtualized spinlocks allow a pvops backend to replace the
783b4ecc126SJeremy Fitzhardinge	  spinlock implementation with something virtualization-friendly
784b4ecc126SJeremy Fitzhardinge	  (for example, block the virtual CPU rather than spinning).
785b4ecc126SJeremy Fitzhardinge
7864c4e4f61SRaghavendra K T	  It has a minimal impact on native kernels and gives a nice performance
7874c4e4f61SRaghavendra K T	  benefit on paravirtualized KVM / Xen kernels.
788b4ecc126SJeremy Fitzhardinge
7894c4e4f61SRaghavendra K T	  If you are unsure how to answer this question, answer Y.
790b4ecc126SJeremy Fitzhardinge
791ecca2502SZhao Yakuiconfig X86_HV_CALLBACK_VECTOR
792ecca2502SZhao Yakui	def_bool n
793ecca2502SZhao Yakui
7946276a074SBorislav Petkovsource "arch/x86/xen/Kconfig"
7956276a074SBorislav Petkov
7966276a074SBorislav Petkovconfig KVM_GUEST
7976276a074SBorislav Petkov	bool "KVM Guest support (including kvmclock)"
7986276a074SBorislav Petkov	depends on PARAVIRT
7996276a074SBorislav Petkov	select PARAVIRT_CLOCK
800a1c4423bSMarcelo Tosatti	select ARCH_CPUIDLE_HALTPOLL
8016276a074SBorislav Petkov	default y
8026276a074SBorislav Petkov	---help---
8036276a074SBorislav Petkov	  This option enables various optimizations for running under the KVM
8046276a074SBorislav Petkov	  hypervisor. It includes a paravirtualized clock, so that instead
8056276a074SBorislav Petkov	  of relying on a PIT (or probably other) emulation by the
8066276a074SBorislav Petkov	  underlying device model, the host provides the guest with
8076276a074SBorislav Petkov	  timing infrastructure such as time of day, and system time
8086276a074SBorislav Petkov
809a1c4423bSMarcelo Tosatticonfig ARCH_CPUIDLE_HALTPOLL
810a1c4423bSMarcelo Tosatti        def_bool n
811a1c4423bSMarcelo Tosatti        prompt "Disable host haltpoll when loading haltpoll driver"
812a1c4423bSMarcelo Tosatti        help
813a1c4423bSMarcelo Tosatti	  If virtualized under KVM, disable host haltpoll.
814a1c4423bSMarcelo Tosatti
8157733607fSMaran Wilsonconfig PVH
8167733607fSMaran Wilson	bool "Support for running PVH guests"
8177733607fSMaran Wilson	---help---
8187733607fSMaran Wilson	  This option enables the PVH entry point for guest virtual machines
8197733607fSMaran Wilson	  as specified in the x86/HVM direct boot ABI.
8207733607fSMaran Wilson
8211e20eb85SSrivatsa Vaddagiriconfig KVM_DEBUG_FS
8221e20eb85SSrivatsa Vaddagiri	bool "Enable debug information for KVM Guests in debugfs"
8231e20eb85SSrivatsa Vaddagiri	depends on KVM_GUEST && DEBUG_FS
8241e20eb85SSrivatsa Vaddagiri	---help---
8251e20eb85SSrivatsa Vaddagiri	  This option enables collection of various statistics for KVM guest.
8261e20eb85SSrivatsa Vaddagiri	  Statistics are displayed in debugfs filesystem. Enabling this option
8271e20eb85SSrivatsa Vaddagiri	  may incur significant overhead.
8281e20eb85SSrivatsa Vaddagiri
8296276a074SBorislav Petkovconfig PARAVIRT_TIME_ACCOUNTING
8306276a074SBorislav Petkov	bool "Paravirtual steal time accounting"
8316276a074SBorislav Petkov	depends on PARAVIRT
8326276a074SBorislav Petkov	---help---
8336276a074SBorislav Petkov	  Select this option to enable fine granularity task steal time
8346276a074SBorislav Petkov	  accounting. Time spent executing other tasks in parallel with
8356276a074SBorislav Petkov	  the current vCPU is discounted from the vCPU power. To account for
8366276a074SBorislav Petkov	  that, there can be a small performance impact.
8376276a074SBorislav Petkov
8386276a074SBorislav Petkov	  If in doubt, say N here.
8396276a074SBorislav Petkov
8407af192c9SGerd Hoffmannconfig PARAVIRT_CLOCK
8417af192c9SGerd Hoffmann	bool
8427af192c9SGerd Hoffmann
8434a362601SJan Kiszkaconfig JAILHOUSE_GUEST
8444a362601SJan Kiszka	bool "Jailhouse non-root cell support"
845abde587bSArnd Bergmann	depends on X86_64 && PCI
84687e65d05SJan Kiszka	select X86_PM_TIMER
8474a362601SJan Kiszka	---help---
8484a362601SJan Kiszka	  This option allows to run Linux as guest in a Jailhouse non-root
8494a362601SJan Kiszka	  cell. You can leave this option disabled if you only want to start
8504a362601SJan Kiszka	  Jailhouse and run Linux afterwards in the root cell.
8514a362601SJan Kiszka
852ec7972c9SZhao Yakuiconfig ACRN_GUEST
853ec7972c9SZhao Yakui	bool "ACRN Guest support"
854ec7972c9SZhao Yakui	depends on X86_64
855498ad393SZhao Yakui	select X86_HV_CALLBACK_VECTOR
856ec7972c9SZhao Yakui	help
857ec7972c9SZhao Yakui	  This option allows to run Linux as guest in the ACRN hypervisor. ACRN is
858ec7972c9SZhao Yakui	  a flexible, lightweight reference open-source hypervisor, built with
859ec7972c9SZhao Yakui	  real-time and safety-criticality in mind. It is built for embedded
860ec7972c9SZhao Yakui	  IOT with small footprint and real-time features. More details can be
861ec7972c9SZhao Yakui	  found in https://projectacrn.org/.
862ec7972c9SZhao Yakui
8636276a074SBorislav Petkovendif #HYPERVISOR_GUEST
86497349135SJeremy Fitzhardinge
865506f1d07SSam Ravnborgsource "arch/x86/Kconfig.cpu"
866506f1d07SSam Ravnborg
867506f1d07SSam Ravnborgconfig HPET_TIMER
8683c2362e6SHarvey Harrison	def_bool X86_64
869506f1d07SSam Ravnborg	prompt "HPET Timer Support" if X86_32
8708f9ca475SIngo Molnar	---help---
871506f1d07SSam Ravnborg	  Use the IA-PC HPET (High Precision Event Timer) to manage
872506f1d07SSam Ravnborg	  time in preference to the PIT and RTC, if a HPET is
873506f1d07SSam Ravnborg	  present.
874506f1d07SSam Ravnborg	  HPET is the next generation timer replacing legacy 8254s.
875506f1d07SSam Ravnborg	  The HPET provides a stable time base on SMP
876506f1d07SSam Ravnborg	  systems, unlike the TSC, but it is more expensive to access,
8774e7f9df2SMichael S. Tsirkin	  as it is off-chip.  The interface used is documented
8784e7f9df2SMichael S. Tsirkin	  in the HPET spec, revision 1.
879506f1d07SSam Ravnborg
880506f1d07SSam Ravnborg	  You can safely choose Y here.  However, HPET will only be
881506f1d07SSam Ravnborg	  activated if the platform and the BIOS support this feature.
882506f1d07SSam Ravnborg	  Otherwise the 8254 will be used for timing services.
883506f1d07SSam Ravnborg
884506f1d07SSam Ravnborg	  Choose N to continue using the legacy 8254 timer.
885506f1d07SSam Ravnborg
886506f1d07SSam Ravnborgconfig HPET_EMULATE_RTC
8873c2362e6SHarvey Harrison	def_bool y
8889d8af78bSBernhard Walle	depends on HPET_TIMER && (RTC=y || RTC=m || RTC_DRV_CMOS=m || RTC_DRV_CMOS=y)
889506f1d07SSam Ravnborg
890bb24c471SJacob Panconfig APB_TIMER
891933b9463SAlan Cox       def_bool y if X86_INTEL_MID
892933b9463SAlan Cox       prompt "Intel MID APB Timer Support" if X86_INTEL_MID
89306c3df49SJamie Iles       select DW_APB_TIMER
894a0c3832aSAlan Cox       depends on X86_INTEL_MID && SFI
895bb24c471SJacob Pan       help
896bb24c471SJacob Pan         APB timer is the replacement for 8254, HPET on X86 MID platforms.
897bb24c471SJacob Pan         The APBT provides a stable time base on SMP
898bb24c471SJacob Pan         systems, unlike the TSC, but it is more expensive to access,
899bb24c471SJacob Pan         as it is off-chip. APB timers are always running regardless of CPU
900bb24c471SJacob Pan         C states, they are used as per CPU clockevent device when possible.
901bb24c471SJacob Pan
9026a108a14SDavid Rientjes# Mark as expert because too many people got it wrong.
903506f1d07SSam Ravnborg# The code disables itself when not needed.
9047ae9392cSThomas Petazzoniconfig DMI
9057ae9392cSThomas Petazzoni	default y
906cf074402SArd Biesheuvel	select DMI_SCAN_MACHINE_NON_EFI_FALLBACK
9076a108a14SDavid Rientjes	bool "Enable DMI scanning" if EXPERT
9088f9ca475SIngo Molnar	---help---
9097ae9392cSThomas Petazzoni	  Enabled scanning of DMI to identify machine quirks. Say Y
9107ae9392cSThomas Petazzoni	  here unless you have verified that your setup is not
9117ae9392cSThomas Petazzoni	  affected by entries in the DMI blacklist. Required by PNP
9127ae9392cSThomas Petazzoni	  BIOS code.
9137ae9392cSThomas Petazzoni
914506f1d07SSam Ravnborgconfig GART_IOMMU
91538901f1cSAndi Kleen	bool "Old AMD GART IOMMU support"
916a4ce5a48SChristoph Hellwig	select IOMMU_HELPER
917506f1d07SSam Ravnborg	select SWIOTLB
91823ac4ae8SAndreas Herrmann	depends on X86_64 && PCI && AMD_NB
9198f9ca475SIngo Molnar	---help---
920ced3c42cSIngo Molnar	  Provides a driver for older AMD Athlon64/Opteron/Turion/Sempron
921ced3c42cSIngo Molnar	  GART based hardware IOMMUs.
922ced3c42cSIngo Molnar
923ced3c42cSIngo Molnar	  The GART supports full DMA access for devices with 32-bit access
924ced3c42cSIngo Molnar	  limitations, on systems with more than 3 GB. This is usually needed
925ced3c42cSIngo Molnar	  for USB, sound, many IDE/SATA chipsets and some other devices.
926ced3c42cSIngo Molnar
927ced3c42cSIngo Molnar	  Newer systems typically have a modern AMD IOMMU, supported via
928ced3c42cSIngo Molnar	  the CONFIG_AMD_IOMMU=y config option.
929ced3c42cSIngo Molnar
930ced3c42cSIngo Molnar	  In normal configurations this driver is only active when needed:
931ced3c42cSIngo Molnar	  there's more than 3 GB of memory and the system contains a
932ced3c42cSIngo Molnar	  32-bit limited device.
933ced3c42cSIngo Molnar
934ced3c42cSIngo Molnar	  If unsure, say Y.
935506f1d07SSam Ravnborg
9361184dc2fSMike Travisconfig MAXSMP
937ddb0c5a6SSamuel Thibault	bool "Enable Maximum number of SMP Processors and NUMA Nodes"
9386ea30386SKees Cook	depends on X86_64 && SMP && DEBUG_KERNEL
93936f5101aSMike Travis	select CPUMASK_OFFSTACK
9408f9ca475SIngo Molnar	---help---
941ddb0c5a6SSamuel Thibault	  Enable maximum number of CPUS and NUMA Nodes for this architecture.
9421184dc2fSMike Travis	  If unsure, say N.
943506f1d07SSam Ravnborg
944aec6487eSIngo Molnar#
945aec6487eSIngo Molnar# The maximum number of CPUs supported:
946aec6487eSIngo Molnar#
947aec6487eSIngo Molnar# The main config value is NR_CPUS, which defaults to NR_CPUS_DEFAULT,
948aec6487eSIngo Molnar# and which can be configured interactively in the
949aec6487eSIngo Molnar# [NR_CPUS_RANGE_BEGIN ... NR_CPUS_RANGE_END] range.
950aec6487eSIngo Molnar#
951aec6487eSIngo Molnar# The ranges are different on 32-bit and 64-bit kernels, depending on
952aec6487eSIngo Molnar# hardware capabilities and scalability features of the kernel.
953aec6487eSIngo Molnar#
954aec6487eSIngo Molnar# ( If MAXSMP is enabled we just use the highest possible value and disable
955aec6487eSIngo Molnar#   interactive configuration. )
956aec6487eSIngo Molnar#
957a0d0bb4dSRandy Dunlap
958aec6487eSIngo Molnarconfig NR_CPUS_RANGE_BEGIN
959a0d0bb4dSRandy Dunlap	int
960aec6487eSIngo Molnar	default NR_CPUS_RANGE_END if MAXSMP
961a0d0bb4dSRandy Dunlap	default    1 if !SMP
962a0d0bb4dSRandy Dunlap	default    2
963a0d0bb4dSRandy Dunlap
964aec6487eSIngo Molnarconfig NR_CPUS_RANGE_END
965a0d0bb4dSRandy Dunlap	int
966a0d0bb4dSRandy Dunlap	depends on X86_32
967aec6487eSIngo Molnar	default   64 if  SMP &&  X86_BIGSMP
968aec6487eSIngo Molnar	default    8 if  SMP && !X86_BIGSMP
969a0d0bb4dSRandy Dunlap	default    1 if !SMP
970a0d0bb4dSRandy Dunlap
971aec6487eSIngo Molnarconfig NR_CPUS_RANGE_END
972a0d0bb4dSRandy Dunlap	int
973a0d0bb4dSRandy Dunlap	depends on X86_64
9741edae1aeSScott Wood	default 8192 if  SMP && CPUMASK_OFFSTACK
9751edae1aeSScott Wood	default  512 if  SMP && !CPUMASK_OFFSTACK
976a0d0bb4dSRandy Dunlap	default    1 if !SMP
977aec6487eSIngo Molnar
978aec6487eSIngo Molnarconfig NR_CPUS_DEFAULT
979aec6487eSIngo Molnar	int
980aec6487eSIngo Molnar	depends on X86_32
981aec6487eSIngo Molnar	default   32 if  X86_BIGSMP
982aec6487eSIngo Molnar	default    8 if  SMP
983aec6487eSIngo Molnar	default    1 if !SMP
984aec6487eSIngo Molnar
985aec6487eSIngo Molnarconfig NR_CPUS_DEFAULT
986aec6487eSIngo Molnar	int
987aec6487eSIngo Molnar	depends on X86_64
988a0d0bb4dSRandy Dunlap	default 8192 if  MAXSMP
989a0d0bb4dSRandy Dunlap	default   64 if  SMP
990aec6487eSIngo Molnar	default    1 if !SMP
991a0d0bb4dSRandy Dunlap
992506f1d07SSam Ravnborgconfig NR_CPUS
99336f5101aSMike Travis	int "Maximum number of CPUs" if SMP && !MAXSMP
994aec6487eSIngo Molnar	range NR_CPUS_RANGE_BEGIN NR_CPUS_RANGE_END
995aec6487eSIngo Molnar	default NR_CPUS_DEFAULT
9968f9ca475SIngo Molnar	---help---
997506f1d07SSam Ravnborg	  This allows you to specify the maximum number of CPUs which this
998bb61ccc7SJosh Boyer	  kernel will support.  If CPUMASK_OFFSTACK is enabled, the maximum
999cad14bb9SKirill A. Shutemov	  supported value is 8192, otherwise the maximum value is 512.  The
1000506f1d07SSam Ravnborg	  minimum value which makes sense is 2.
1001506f1d07SSam Ravnborg
1002aec6487eSIngo Molnar	  This is purely to save memory: each supported CPU adds about 8KB
1003aec6487eSIngo Molnar	  to the kernel image.
1004506f1d07SSam Ravnborg
1005506f1d07SSam Ravnborgconfig SCHED_SMT
1006dbe73364SThomas Gleixner	def_bool y if SMP
1007506f1d07SSam Ravnborg
1008506f1d07SSam Ravnborgconfig SCHED_MC
10093c2362e6SHarvey Harrison	def_bool y
10103c2362e6SHarvey Harrison	prompt "Multi-core scheduler support"
1011c8e56d20SBorislav Petkov	depends on SMP
10128f9ca475SIngo Molnar	---help---
1013506f1d07SSam Ravnborg	  Multi-core scheduler support improves the CPU scheduler's decision
1014506f1d07SSam Ravnborg	  making when dealing with multi-core CPU chips at a cost of slightly
1015506f1d07SSam Ravnborg	  increased overhead in some places. If unsure say N here.
1016506f1d07SSam Ravnborg
1017de966cf4STim Chenconfig SCHED_MC_PRIO
1018de966cf4STim Chen	bool "CPU core priorities scheduler support"
10190a21fc12SIngo Molnar	depends on SCHED_MC && CPU_SUP_INTEL
10200a21fc12SIngo Molnar	select X86_INTEL_PSTATE
10210a21fc12SIngo Molnar	select CPU_FREQ
1022de966cf4STim Chen	default y
10235e76b2abSTim Chen	---help---
1024de966cf4STim Chen	  Intel Turbo Boost Max Technology 3.0 enabled CPUs have a
1025de966cf4STim Chen	  core ordering determined at manufacturing time, which allows
1026de966cf4STim Chen	  certain cores to reach higher turbo frequencies (when running
1027de966cf4STim Chen	  single threaded workloads) than others.
1028de966cf4STim Chen
1029de966cf4STim Chen	  Enabling this kernel feature teaches the scheduler about
1030de966cf4STim Chen	  the TBM3 (aka ITMT) priority order of the CPU cores and adjusts the
1031de966cf4STim Chen	  scheduler's CPU selection logic accordingly, so that higher
1032de966cf4STim Chen	  overall system performance can be achieved.
1033de966cf4STim Chen
1034de966cf4STim Chen	  This feature will have no effect on CPUs without this feature.
1035de966cf4STim Chen
1036de966cf4STim Chen	  If unsure say Y here.
10375e76b2abSTim Chen
103830b8b006SThomas Gleixnerconfig UP_LATE_INIT
103930b8b006SThomas Gleixner       def_bool y
1040ba360f88SThomas Gleixner       depends on !SMP && X86_LOCAL_APIC
104130b8b006SThomas Gleixner
1042506f1d07SSam Ravnborgconfig X86_UP_APIC
104350849eefSJan Beulich	bool "Local APIC support on uniprocessors" if !PCI_MSI
104450849eefSJan Beulich	default PCI_MSI
104538a1dfdaSBryan O'Donoghue	depends on X86_32 && !SMP && !X86_32_NON_STANDARD
10468f9ca475SIngo Molnar	---help---
1047506f1d07SSam Ravnborg	  A local APIC (Advanced Programmable Interrupt Controller) is an
1048506f1d07SSam Ravnborg	  integrated interrupt controller in the CPU. If you have a single-CPU
1049506f1d07SSam Ravnborg	  system which has a processor with a local APIC, you can say Y here to
1050506f1d07SSam Ravnborg	  enable and use it. If you say Y here even though your machine doesn't
1051506f1d07SSam Ravnborg	  have a local APIC, then the kernel will still run with no slowdown at
1052506f1d07SSam Ravnborg	  all. The local APIC supports CPU-generated self-interrupts (timer,
1053506f1d07SSam Ravnborg	  performance counters), and the NMI watchdog which detects hard
1054506f1d07SSam Ravnborg	  lockups.
1055506f1d07SSam Ravnborg
1056506f1d07SSam Ravnborgconfig X86_UP_IOAPIC
1057506f1d07SSam Ravnborg	bool "IO-APIC support on uniprocessors"
1058506f1d07SSam Ravnborg	depends on X86_UP_APIC
10598f9ca475SIngo Molnar	---help---
1060506f1d07SSam Ravnborg	  An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an
1061506f1d07SSam Ravnborg	  SMP-capable replacement for PC-style interrupt controllers. Most
1062506f1d07SSam Ravnborg	  SMP systems and many recent uniprocessor systems have one.
1063506f1d07SSam Ravnborg
1064506f1d07SSam Ravnborg	  If you have a single-CPU system with an IO-APIC, you can say Y here
1065506f1d07SSam Ravnborg	  to use it. If you say Y here even though your machine doesn't have
1066506f1d07SSam Ravnborg	  an IO-APIC, then the kernel will still run with no slowdown at all.
1067506f1d07SSam Ravnborg
1068506f1d07SSam Ravnborgconfig X86_LOCAL_APIC
10693c2362e6SHarvey Harrison	def_bool y
10700dbc6078SThomas Petazzoni	depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC || PCI_MSI
1071b5dc8e6cSJiang Liu	select IRQ_DOMAIN_HIERARCHY
107252f518a3SJiang Liu	select PCI_MSI_IRQ_DOMAIN if PCI_MSI
1073506f1d07SSam Ravnborg
1074506f1d07SSam Ravnborgconfig X86_IO_APIC
1075b1da1e71SJan Beulich	def_bool y
1076b1da1e71SJan Beulich	depends on X86_LOCAL_APIC || X86_UP_IOAPIC
1077506f1d07SSam Ravnborg
107841b9eb26SStefan Assmannconfig X86_REROUTE_FOR_BROKEN_BOOT_IRQS
107941b9eb26SStefan Assmann	bool "Reroute for broken boot IRQs"
108041b9eb26SStefan Assmann	depends on X86_IO_APIC
10818f9ca475SIngo Molnar	---help---
108241b9eb26SStefan Assmann	  This option enables a workaround that fixes a source of
108341b9eb26SStefan Assmann	  spurious interrupts. This is recommended when threaded
108441b9eb26SStefan Assmann	  interrupt handling is used on systems where the generation of
108541b9eb26SStefan Assmann	  superfluous "boot interrupts" cannot be disabled.
108641b9eb26SStefan Assmann
108741b9eb26SStefan Assmann	  Some chipsets generate a legacy INTx "boot IRQ" when the IRQ
108841b9eb26SStefan Assmann	  entry in the chipset's IO-APIC is masked (as, e.g. the RT
108941b9eb26SStefan Assmann	  kernel does during interrupt handling). On chipsets where this
109041b9eb26SStefan Assmann	  boot IRQ generation cannot be disabled, this workaround keeps
109141b9eb26SStefan Assmann	  the original IRQ line masked so that only the equivalent "boot
109241b9eb26SStefan Assmann	  IRQ" is delivered to the CPUs. The workaround also tells the
109341b9eb26SStefan Assmann	  kernel to set up the IRQ handler on the boot IRQ line. In this
109441b9eb26SStefan Assmann	  way only one interrupt is delivered to the kernel. Otherwise
109541b9eb26SStefan Assmann	  the spurious second interrupt may cause the kernel to bring
109641b9eb26SStefan Assmann	  down (vital) interrupt lines.
109741b9eb26SStefan Assmann
109841b9eb26SStefan Assmann	  Only affects "broken" chipsets. Interrupt sharing may be
109941b9eb26SStefan Assmann	  increased on these systems.
110041b9eb26SStefan Assmann
1101506f1d07SSam Ravnborgconfig X86_MCE
1102bab9bc65SAndi Kleen	bool "Machine Check / overheating reporting"
1103648ed940SChen, Gong	select GENERIC_ALLOCATOR
1104e57dbaf7SBorislav Petkov	default y
1105506f1d07SSam Ravnborg	---help---
1106bab9bc65SAndi Kleen	  Machine Check support allows the processor to notify the
1107bab9bc65SAndi Kleen	  kernel if it detects a problem (e.g. overheating, data corruption).
1108506f1d07SSam Ravnborg	  The action the kernel takes depends on the severity of the problem,
1109bab9bc65SAndi Kleen	  ranging from warning messages to halting the machine.
11104efc0670SAndi Kleen
11115de97c9fSTony Luckconfig X86_MCELOG_LEGACY
11125de97c9fSTony Luck	bool "Support for deprecated /dev/mcelog character device"
11135de97c9fSTony Luck	depends on X86_MCE
11145de97c9fSTony Luck	---help---
11155de97c9fSTony Luck	  Enable support for /dev/mcelog which is needed by the old mcelog
11165de97c9fSTony Luck	  userspace logging daemon. Consider switching to the new generation
11175de97c9fSTony Luck	  rasdaemon solution.
11185de97c9fSTony Luck
1119506f1d07SSam Ravnborgconfig X86_MCE_INTEL
11203c2362e6SHarvey Harrison	def_bool y
11213c2362e6SHarvey Harrison	prompt "Intel MCE features"
1122c1ebf835SAndi Kleen	depends on X86_MCE && X86_LOCAL_APIC
11238f9ca475SIngo Molnar	---help---
1124506f1d07SSam Ravnborg	   Additional support for intel specific MCE features such as
1125506f1d07SSam Ravnborg	   the thermal monitor.
1126506f1d07SSam Ravnborg
1127506f1d07SSam Ravnborgconfig X86_MCE_AMD
11283c2362e6SHarvey Harrison	def_bool y
11293c2362e6SHarvey Harrison	prompt "AMD MCE features"
1130f5382de9SYazen Ghannam	depends on X86_MCE && X86_LOCAL_APIC && AMD_NB
11318f9ca475SIngo Molnar	---help---
1132506f1d07SSam Ravnborg	   Additional support for AMD specific MCE features such as
1133506f1d07SSam Ravnborg	   the DRAM Error Threshold.
1134506f1d07SSam Ravnborg
11354efc0670SAndi Kleenconfig X86_ANCIENT_MCE
11366fc108a0SJan Beulich	bool "Support for old Pentium 5 / WinChip machine checks"
1137c31d9633SAndi Kleen	depends on X86_32 && X86_MCE
11384efc0670SAndi Kleen	---help---
11394efc0670SAndi Kleen	  Include support for machine check handling on old Pentium 5 or WinChip
11405065a706SMasanari Iida	  systems. These typically need to be enabled explicitly on the command
11414efc0670SAndi Kleen	  line.
11424efc0670SAndi Kleen
1143b2762686SAndi Kleenconfig X86_MCE_THRESHOLD
1144b2762686SAndi Kleen	depends on X86_MCE_AMD || X86_MCE_INTEL
11456fc108a0SJan Beulich	def_bool y
1146b2762686SAndi Kleen
1147ea149b36SAndi Kleenconfig X86_MCE_INJECT
1148bc8e80d5SBorislav Petkov	depends on X86_MCE && X86_LOCAL_APIC && DEBUG_FS
1149ea149b36SAndi Kleen	tristate "Machine check injector support"
1150ea149b36SAndi Kleen	---help---
1151ea149b36SAndi Kleen	  Provide support for injecting machine checks for testing purposes.
1152ea149b36SAndi Kleen	  If you don't know what a machine check is and you don't do kernel
1153ea149b36SAndi Kleen	  QA it is safe to say n.
1154ea149b36SAndi Kleen
11554efc0670SAndi Kleenconfig X86_THERMAL_VECTOR
11564efc0670SAndi Kleen	def_bool y
11575bb38adcSAndi Kleen	depends on X86_MCE_INTEL
11584efc0670SAndi Kleen
115907dc900eSPeter Zijlstrasource "arch/x86/events/Kconfig"
1160e633c65aSKan Liang
11615aef51c3SAndy Lutomirskiconfig X86_LEGACY_VM86
11621e642812SIngo Molnar	bool "Legacy VM86 support"
1163506f1d07SSam Ravnborg	depends on X86_32
11648f9ca475SIngo Molnar	---help---
11655aef51c3SAndy Lutomirski	  This option allows user programs to put the CPU into V8086
11665aef51c3SAndy Lutomirski	  mode, which is an 80286-era approximation of 16-bit real mode.
11675aef51c3SAndy Lutomirski
11685aef51c3SAndy Lutomirski	  Some very old versions of X and/or vbetool require this option
11695aef51c3SAndy Lutomirski	  for user mode setting.  Similarly, DOSEMU will use it if
11705aef51c3SAndy Lutomirski	  available to accelerate real mode DOS programs.  However, any
11715aef51c3SAndy Lutomirski	  recent version of DOSEMU, X, or vbetool should be fully
11725aef51c3SAndy Lutomirski	  functional even without kernel VM86 support, as they will all
11731e642812SIngo Molnar	  fall back to software emulation. Nevertheless, if you are using
11741e642812SIngo Molnar	  a 16-bit DOS program where 16-bit performance matters, vm86
11751e642812SIngo Molnar	  mode might be faster than emulation and you might want to
11761e642812SIngo Molnar	  enable this option.
11775aef51c3SAndy Lutomirski
11781e642812SIngo Molnar	  Note that any app that works on a 64-bit kernel is unlikely to
11791e642812SIngo Molnar	  need this option, as 64-bit kernels don't, and can't, support
11801e642812SIngo Molnar	  V8086 mode. This option is also unrelated to 16-bit protected
11811e642812SIngo Molnar	  mode and is not needed to run most 16-bit programs under Wine.
11825aef51c3SAndy Lutomirski
11831e642812SIngo Molnar	  Enabling this option increases the complexity of the kernel
11841e642812SIngo Molnar	  and slows down exception handling a tiny bit.
11855aef51c3SAndy Lutomirski
11861e642812SIngo Molnar	  If unsure, say N here.
11875aef51c3SAndy Lutomirski
11885aef51c3SAndy Lutomirskiconfig VM86
11895aef51c3SAndy Lutomirski       bool
11905aef51c3SAndy Lutomirski       default X86_LEGACY_VM86
119134273f41SH. Peter Anvin
119234273f41SH. Peter Anvinconfig X86_16BIT
119334273f41SH. Peter Anvin	bool "Enable support for 16-bit segments" if EXPERT
119434273f41SH. Peter Anvin	default y
1195a5b9e5a2SAndy Lutomirski	depends on MODIFY_LDT_SYSCALL
119634273f41SH. Peter Anvin	---help---
119734273f41SH. Peter Anvin	  This option is required by programs like Wine to run 16-bit
119834273f41SH. Peter Anvin	  protected mode legacy code on x86 processors.  Disabling
119934273f41SH. Peter Anvin	  this option saves about 300 bytes on i386, or around 6K text
120034273f41SH. Peter Anvin	  plus 16K runtime memory on x86-64,
120134273f41SH. Peter Anvin
120234273f41SH. Peter Anvinconfig X86_ESPFIX32
120334273f41SH. Peter Anvin	def_bool y
120434273f41SH. Peter Anvin	depends on X86_16BIT && X86_32
1205506f1d07SSam Ravnborg
1206197725deSH. Peter Anvinconfig X86_ESPFIX64
1207197725deSH. Peter Anvin	def_bool y
120834273f41SH. Peter Anvin	depends on X86_16BIT && X86_64
1209506f1d07SSam Ravnborg
12101ad83c85SAndy Lutomirskiconfig X86_VSYSCALL_EMULATION
12111ad83c85SAndy Lutomirski       bool "Enable vsyscall emulation" if EXPERT
12121ad83c85SAndy Lutomirski       default y
12131ad83c85SAndy Lutomirski       depends on X86_64
12141ad83c85SAndy Lutomirski       ---help---
12151ad83c85SAndy Lutomirski	 This enables emulation of the legacy vsyscall page.  Disabling
12161ad83c85SAndy Lutomirski	 it is roughly equivalent to booting with vsyscall=none, except
12171ad83c85SAndy Lutomirski	 that it will also disable the helpful warning if a program
12181ad83c85SAndy Lutomirski	 tries to use a vsyscall.  With this option set to N, offending
12191ad83c85SAndy Lutomirski	 programs will just segfault, citing addresses of the form
12201ad83c85SAndy Lutomirski	 0xffffffffff600?00.
12211ad83c85SAndy Lutomirski
12221ad83c85SAndy Lutomirski	 This option is required by many programs built before 2013, and
12231ad83c85SAndy Lutomirski	 care should be used even with newer programs if set to N.
12241ad83c85SAndy Lutomirski
12251ad83c85SAndy Lutomirski	 Disabling this option saves about 7K of kernel size and
12261ad83c85SAndy Lutomirski	 possibly 4K of additional runtime pagetable memory.
12271ad83c85SAndy Lutomirski
1228111e7b15SThomas Gleixnerconfig X86_IOPL_IOPERM
1229111e7b15SThomas Gleixner	bool "IOPERM and IOPL Emulation"
1230a24ca997SThomas Gleixner	default y
1231c8137aceSThomas Gleixner	---help---
1232111e7b15SThomas Gleixner	  This enables the ioperm() and iopl() syscalls which are necessary
1233111e7b15SThomas Gleixner	  for legacy applications.
1234111e7b15SThomas Gleixner
1235c8137aceSThomas Gleixner	  Legacy IOPL support is an overbroad mechanism which allows user
1236c8137aceSThomas Gleixner	  space aside of accessing all 65536 I/O ports also to disable
1237c8137aceSThomas Gleixner	  interrupts. To gain this access the caller needs CAP_SYS_RAWIO
1238c8137aceSThomas Gleixner	  capabilities and permission from potentially active security
1239c8137aceSThomas Gleixner	  modules.
1240c8137aceSThomas Gleixner
1241c8137aceSThomas Gleixner	  The emulation restricts the functionality of the syscall to
1242c8137aceSThomas Gleixner	  only allowing the full range I/O port access, but prevents the
1243a24ca997SThomas Gleixner	  ability to disable interrupts from user space which would be
1244a24ca997SThomas Gleixner	  granted if the hardware IOPL mechanism would be used.
1245c8137aceSThomas Gleixner
1246506f1d07SSam Ravnborgconfig TOSHIBA
1247506f1d07SSam Ravnborg	tristate "Toshiba Laptop support"
1248506f1d07SSam Ravnborg	depends on X86_32
1249506f1d07SSam Ravnborg	---help---
1250506f1d07SSam Ravnborg	  This adds a driver to safely access the System Management Mode of
1251506f1d07SSam Ravnborg	  the CPU on Toshiba portables with a genuine Toshiba BIOS. It does
1252506f1d07SSam Ravnborg	  not work on models with a Phoenix BIOS. The System Management Mode
1253506f1d07SSam Ravnborg	  is used to set the BIOS and power saving options on Toshiba portables.
1254506f1d07SSam Ravnborg
1255506f1d07SSam Ravnborg	  For information on utilities to make use of this driver see the
1256506f1d07SSam Ravnborg	  Toshiba Linux utilities web site at:
1257506f1d07SSam Ravnborg	  <http://www.buzzard.org.uk/toshiba/>.
1258506f1d07SSam Ravnborg
1259506f1d07SSam Ravnborg	  Say Y if you intend to run this kernel on a Toshiba portable.
1260506f1d07SSam Ravnborg	  Say N otherwise.
1261506f1d07SSam Ravnborg
1262506f1d07SSam Ravnborgconfig I8K
1263039ae585SPali Rohár	tristate "Dell i8k legacy laptop support"
1264949a9d70SJean Delvare	select HWMON
1265039ae585SPali Rohár	select SENSORS_DELL_SMM
1266506f1d07SSam Ravnborg	---help---
1267039ae585SPali Rohár	  This option enables legacy /proc/i8k userspace interface in hwmon
1268039ae585SPali Rohár	  dell-smm-hwmon driver. Character file /proc/i8k reports bios version,
1269039ae585SPali Rohár	  temperature and allows controlling fan speeds of Dell laptops via
1270039ae585SPali Rohár	  System Management Mode. For old Dell laptops (like Dell Inspiron 8000)
1271039ae585SPali Rohár	  it reports also power and hotkey status. For fan speed control is
1272039ae585SPali Rohár	  needed userspace package i8kutils.
1273506f1d07SSam Ravnborg
1274039ae585SPali Rohár	  Say Y if you intend to run this kernel on old Dell laptops or want to
1275039ae585SPali Rohár	  use userspace package i8kutils.
1276506f1d07SSam Ravnborg	  Say N otherwise.
1277506f1d07SSam Ravnborg
1278506f1d07SSam Ravnborgconfig X86_REBOOTFIXUPS
12799ba16087SJan Beulich	bool "Enable X86 board specific fixups for reboot"
12809ba16087SJan Beulich	depends on X86_32
1281506f1d07SSam Ravnborg	---help---
1282506f1d07SSam Ravnborg	  This enables chipset and/or board specific fixups to be done
1283506f1d07SSam Ravnborg	  in order to get reboot to work correctly. This is only needed on
1284506f1d07SSam Ravnborg	  some combinations of hardware and BIOS. The symptom, for which
1285506f1d07SSam Ravnborg	  this config is intended, is when reboot ends with a stalled/hung
1286506f1d07SSam Ravnborg	  system.
1287506f1d07SSam Ravnborg
1288506f1d07SSam Ravnborg	  Currently, the only fixup is for the Geode machines using
12895e3a77e9SFlorian Fainelli	  CS5530A and CS5536 chipsets and the RDC R-321x SoC.
1290506f1d07SSam Ravnborg
1291506f1d07SSam Ravnborg	  Say Y if you want to enable the fixup. Currently, it's safe to
1292506f1d07SSam Ravnborg	  enable this option even if you don't need it.
1293506f1d07SSam Ravnborg	  Say N otherwise.
1294506f1d07SSam Ravnborg
1295506f1d07SSam Ravnborgconfig MICROCODE
12969a2bc335SBorislav Petkov	bool "CPU microcode loading support"
12979a2bc335SBorislav Petkov	default y
129880030e3dSBorislav Petkov	depends on CPU_SUP_AMD || CPU_SUP_INTEL
1299506f1d07SSam Ravnborg	select FW_LOADER
1300506f1d07SSam Ravnborg	---help---
1301506f1d07SSam Ravnborg	  If you say Y here, you will be able to update the microcode on
13025f9c01aaSBorislav Petkov	  Intel and AMD processors. The Intel support is for the IA32 family,
13035f9c01aaSBorislav Petkov	  e.g. Pentium Pro, Pentium II, Pentium III, Pentium 4, Xeon etc. The
13045f9c01aaSBorislav Petkov	  AMD support is for families 0x10 and later. You will obviously need
13055f9c01aaSBorislav Petkov	  the actual microcode binary data itself which is not shipped with
13065f9c01aaSBorislav Petkov	  the Linux kernel.
1307506f1d07SSam Ravnborg
13085f9c01aaSBorislav Petkov	  The preferred method to load microcode from a detached initrd is described
1309cb1aaebeSMauro Carvalho Chehab	  in Documentation/x86/microcode.rst. For that you need to enable
13105f9c01aaSBorislav Petkov	  CONFIG_BLK_DEV_INITRD in order for the loader to be able to scan the
13115f9c01aaSBorislav Petkov	  initrd for microcode blobs.
1312506f1d07SSam Ravnborg
1313c508c46eSBenjamin Gilbert	  In addition, you can build the microcode into the kernel. For that you
1314c508c46eSBenjamin Gilbert	  need to add the vendor-supplied microcode to the CONFIG_EXTRA_FIRMWARE
1315c508c46eSBenjamin Gilbert	  config option.
1316506f1d07SSam Ravnborg
13178d86f390SPeter Orubaconfig MICROCODE_INTEL
1318e43f6e67SBorislav Petkov	bool "Intel microcode loading support"
13198d86f390SPeter Oruba	depends on MICROCODE
13208d86f390SPeter Oruba	default MICROCODE
13218d86f390SPeter Oruba	select FW_LOADER
13228f9ca475SIngo Molnar	---help---
13238d86f390SPeter Oruba	  This options enables microcode patch loading support for Intel
13248d86f390SPeter Oruba	  processors.
13258d86f390SPeter Oruba
1326b8989db9SAlan	  For the current Intel microcode data package go to
1327b8989db9SAlan	  <https://downloadcenter.intel.com> and search for
1328b8989db9SAlan	  'Linux Processor Microcode Data File'.
13298d86f390SPeter Oruba
133080cc9f10SPeter Orubaconfig MICROCODE_AMD
1331e43f6e67SBorislav Petkov	bool "AMD microcode loading support"
133280cc9f10SPeter Oruba	depends on MICROCODE
133380cc9f10SPeter Oruba	select FW_LOADER
13348f9ca475SIngo Molnar	---help---
133580cc9f10SPeter Oruba	  If you select this option, microcode patch loading support for AMD
133680cc9f10SPeter Oruba	  processors will be enabled.
133780cc9f10SPeter Oruba
1338506f1d07SSam Ravnborgconfig MICROCODE_OLD_INTERFACE
1339c02f48e0SBorislav Petkov	bool "Ancient loading interface (DEPRECATED)"
1340c02f48e0SBorislav Petkov	default n
1341506f1d07SSam Ravnborg	depends on MICROCODE
1342c02f48e0SBorislav Petkov	---help---
1343c02f48e0SBorislav Petkov	  DO NOT USE THIS! This is the ancient /dev/cpu/microcode interface
1344c02f48e0SBorislav Petkov	  which was used by userspace tools like iucode_tool and microcode.ctl.
1345c02f48e0SBorislav Petkov	  It is inadequate because it runs too late to be able to properly
1346c02f48e0SBorislav Petkov	  load microcode on a machine and it needs special tools. Instead, you
1347c02f48e0SBorislav Petkov	  should've switched to the early loading method with the initrd or
1348cb1aaebeSMauro Carvalho Chehab	  builtin microcode by now: Documentation/x86/microcode.rst
1349506f1d07SSam Ravnborg
1350506f1d07SSam Ravnborgconfig X86_MSR
1351506f1d07SSam Ravnborg	tristate "/dev/cpu/*/msr - Model-specific register support"
13528f9ca475SIngo Molnar	---help---
1353506f1d07SSam Ravnborg	  This device gives privileged processes access to the x86
1354506f1d07SSam Ravnborg	  Model-Specific Registers (MSRs).  It is a character device with
1355506f1d07SSam Ravnborg	  major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr.
1356506f1d07SSam Ravnborg	  MSR accesses are directed to a specific CPU on multi-processor
1357506f1d07SSam Ravnborg	  systems.
1358506f1d07SSam Ravnborg
1359506f1d07SSam Ravnborgconfig X86_CPUID
1360506f1d07SSam Ravnborg	tristate "/dev/cpu/*/cpuid - CPU information support"
13618f9ca475SIngo Molnar	---help---
1362506f1d07SSam Ravnborg	  This device gives processes access to the x86 CPUID instruction to
1363506f1d07SSam Ravnborg	  be executed on a specific processor.  It is a character device
1364506f1d07SSam Ravnborg	  with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to
1365506f1d07SSam Ravnborg	  /dev/cpu/31/cpuid.
1366506f1d07SSam Ravnborg
1367506f1d07SSam Ravnborgchoice
1368506f1d07SSam Ravnborg	prompt "High Memory Support"
13696fc108a0SJan Beulich	default HIGHMEM4G
1370506f1d07SSam Ravnborg	depends on X86_32
1371506f1d07SSam Ravnborg
1372506f1d07SSam Ravnborgconfig NOHIGHMEM
1373506f1d07SSam Ravnborg	bool "off"
1374506f1d07SSam Ravnborg	---help---
1375506f1d07SSam Ravnborg	  Linux can use up to 64 Gigabytes of physical memory on x86 systems.
1376506f1d07SSam Ravnborg	  However, the address space of 32-bit x86 processors is only 4
1377506f1d07SSam Ravnborg	  Gigabytes large. That means that, if you have a large amount of
1378506f1d07SSam Ravnborg	  physical memory, not all of it can be "permanently mapped" by the
1379506f1d07SSam Ravnborg	  kernel. The physical memory that's not permanently mapped is called
1380506f1d07SSam Ravnborg	  "high memory".
1381506f1d07SSam Ravnborg
1382506f1d07SSam Ravnborg	  If you are compiling a kernel which will never run on a machine with
1383506f1d07SSam Ravnborg	  more than 1 Gigabyte total physical RAM, answer "off" here (default
1384506f1d07SSam Ravnborg	  choice and suitable for most users). This will result in a "3GB/1GB"
1385506f1d07SSam Ravnborg	  split: 3GB are mapped so that each process sees a 3GB virtual memory
1386506f1d07SSam Ravnborg	  space and the remaining part of the 4GB virtual memory space is used
1387506f1d07SSam Ravnborg	  by the kernel to permanently map as much physical memory as
1388506f1d07SSam Ravnborg	  possible.
1389506f1d07SSam Ravnborg
1390506f1d07SSam Ravnborg	  If the machine has between 1 and 4 Gigabytes physical RAM, then
1391506f1d07SSam Ravnborg	  answer "4GB" here.
1392506f1d07SSam Ravnborg
1393506f1d07SSam Ravnborg	  If more than 4 Gigabytes is used then answer "64GB" here. This
1394506f1d07SSam Ravnborg	  selection turns Intel PAE (Physical Address Extension) mode on.
1395506f1d07SSam Ravnborg	  PAE implements 3-level paging on IA32 processors. PAE is fully
1396506f1d07SSam Ravnborg	  supported by Linux, PAE mode is implemented on all recent Intel
1397506f1d07SSam Ravnborg	  processors (Pentium Pro and better). NOTE: If you say "64GB" here,
1398506f1d07SSam Ravnborg	  then the kernel will not boot on CPUs that don't support PAE!
1399506f1d07SSam Ravnborg
1400506f1d07SSam Ravnborg	  The actual amount of total physical memory will either be
1401506f1d07SSam Ravnborg	  auto detected or can be forced by using a kernel command line option
1402506f1d07SSam Ravnborg	  such as "mem=256M". (Try "man bootparam" or see the documentation of
1403506f1d07SSam Ravnborg	  your boot loader (lilo or loadlin) about how to pass options to the
1404506f1d07SSam Ravnborg	  kernel at boot time.)
1405506f1d07SSam Ravnborg
1406506f1d07SSam Ravnborg	  If unsure, say "off".
1407506f1d07SSam Ravnborg
1408506f1d07SSam Ravnborgconfig HIGHMEM4G
1409506f1d07SSam Ravnborg	bool "4GB"
14108f9ca475SIngo Molnar	---help---
1411506f1d07SSam Ravnborg	  Select this if you have a 32-bit processor and between 1 and 4
1412506f1d07SSam Ravnborg	  gigabytes of physical RAM.
1413506f1d07SSam Ravnborg
1414506f1d07SSam Ravnborgconfig HIGHMEM64G
1415506f1d07SSam Ravnborg	bool "64GB"
141669b8d3fcSMatthew Whitehead	depends on !M486 && !M586 && !M586TSC && !M586MMX && !MGEODE_LX && !MGEODEGX1 && !MCYRIXIII && !MELAN && !MWINCHIPC6 && !WINCHIP3D && !MK6
1417506f1d07SSam Ravnborg	select X86_PAE
14188f9ca475SIngo Molnar	---help---
1419506f1d07SSam Ravnborg	  Select this if you have a 32-bit processor and more than 4
1420506f1d07SSam Ravnborg	  gigabytes of physical RAM.
1421506f1d07SSam Ravnborg
1422506f1d07SSam Ravnborgendchoice
1423506f1d07SSam Ravnborg
1424506f1d07SSam Ravnborgchoice
14256a108a14SDavid Rientjes	prompt "Memory split" if EXPERT
1426506f1d07SSam Ravnborg	default VMSPLIT_3G
1427506f1d07SSam Ravnborg	depends on X86_32
14288f9ca475SIngo Molnar	---help---
1429506f1d07SSam Ravnborg	  Select the desired split between kernel and user memory.
1430506f1d07SSam Ravnborg
1431506f1d07SSam Ravnborg	  If the address range available to the kernel is less than the
1432506f1d07SSam Ravnborg	  physical memory installed, the remaining memory will be available
1433506f1d07SSam Ravnborg	  as "high memory". Accessing high memory is a little more costly
1434506f1d07SSam Ravnborg	  than low memory, as it needs to be mapped into the kernel first.
1435506f1d07SSam Ravnborg	  Note that increasing the kernel address space limits the range
1436506f1d07SSam Ravnborg	  available to user programs, making the address space there
1437506f1d07SSam Ravnborg	  tighter.  Selecting anything other than the default 3G/1G split
1438506f1d07SSam Ravnborg	  will also likely make your kernel incompatible with binary-only
1439506f1d07SSam Ravnborg	  kernel modules.
1440506f1d07SSam Ravnborg
1441506f1d07SSam Ravnborg	  If you are not absolutely sure what you are doing, leave this
1442506f1d07SSam Ravnborg	  option alone!
1443506f1d07SSam Ravnborg
1444506f1d07SSam Ravnborg	config VMSPLIT_3G
1445506f1d07SSam Ravnborg		bool "3G/1G user/kernel split"
1446506f1d07SSam Ravnborg	config VMSPLIT_3G_OPT
1447506f1d07SSam Ravnborg		depends on !X86_PAE
1448506f1d07SSam Ravnborg		bool "3G/1G user/kernel split (for full 1G low memory)"
1449506f1d07SSam Ravnborg	config VMSPLIT_2G
1450506f1d07SSam Ravnborg		bool "2G/2G user/kernel split"
1451506f1d07SSam Ravnborg	config VMSPLIT_2G_OPT
1452506f1d07SSam Ravnborg		depends on !X86_PAE
1453506f1d07SSam Ravnborg		bool "2G/2G user/kernel split (for full 2G low memory)"
1454506f1d07SSam Ravnborg	config VMSPLIT_1G
1455506f1d07SSam Ravnborg		bool "1G/3G user/kernel split"
1456506f1d07SSam Ravnborgendchoice
1457506f1d07SSam Ravnborg
1458506f1d07SSam Ravnborgconfig PAGE_OFFSET
1459506f1d07SSam Ravnborg	hex
1460506f1d07SSam Ravnborg	default 0xB0000000 if VMSPLIT_3G_OPT
1461506f1d07SSam Ravnborg	default 0x80000000 if VMSPLIT_2G
1462506f1d07SSam Ravnborg	default 0x78000000 if VMSPLIT_2G_OPT
1463506f1d07SSam Ravnborg	default 0x40000000 if VMSPLIT_1G
1464506f1d07SSam Ravnborg	default 0xC0000000
1465506f1d07SSam Ravnborg	depends on X86_32
1466506f1d07SSam Ravnborg
1467506f1d07SSam Ravnborgconfig HIGHMEM
14683c2362e6SHarvey Harrison	def_bool y
1469506f1d07SSam Ravnborg	depends on X86_32 && (HIGHMEM64G || HIGHMEM4G)
1470506f1d07SSam Ravnborg
1471506f1d07SSam Ravnborgconfig X86_PAE
14729ba16087SJan Beulich	bool "PAE (Physical Address Extension) Support"
1473506f1d07SSam Ravnborg	depends on X86_32 && !HIGHMEM4G
1474d4a451d5SChristoph Hellwig	select PHYS_ADDR_T_64BIT
14759d99c712SChristian Melki	select SWIOTLB
14768f9ca475SIngo Molnar	---help---
1477506f1d07SSam Ravnborg	  PAE is required for NX support, and furthermore enables
1478506f1d07SSam Ravnborg	  larger swapspace support for non-overcommit purposes. It
1479506f1d07SSam Ravnborg	  has the cost of more pagetable lookup overhead, and also
1480506f1d07SSam Ravnborg	  consumes more pagetable space per process.
1481506f1d07SSam Ravnborg
148277ef56e4SKirill A. Shutemovconfig X86_5LEVEL
148377ef56e4SKirill A. Shutemov	bool "Enable 5-level page tables support"
148418ec1eafSKirill A. Shutemov	default y
1485eedb92abSKirill A. Shutemov	select DYNAMIC_MEMORY_LAYOUT
1486162434e7SKirill A. Shutemov	select SPARSEMEM_VMEMMAP
148777ef56e4SKirill A. Shutemov	depends on X86_64
148877ef56e4SKirill A. Shutemov	---help---
148977ef56e4SKirill A. Shutemov	  5-level paging enables access to larger address space:
149077ef56e4SKirill A. Shutemov	  upto 128 PiB of virtual address space and 4 PiB of
149177ef56e4SKirill A. Shutemov	  physical address space.
149277ef56e4SKirill A. Shutemov
149377ef56e4SKirill A. Shutemov	  It will be supported by future Intel CPUs.
149477ef56e4SKirill A. Shutemov
14956657fca0SKirill A. Shutemov	  A kernel with the option enabled can be booted on machines that
14966657fca0SKirill A. Shutemov	  support 4- or 5-level paging.
149777ef56e4SKirill A. Shutemov
1498cb1aaebeSMauro Carvalho Chehab	  See Documentation/x86/x86_64/5level-paging.rst for more
149977ef56e4SKirill A. Shutemov	  information.
150077ef56e4SKirill A. Shutemov
150177ef56e4SKirill A. Shutemov	  Say N if unsure.
150277ef56e4SKirill A. Shutemov
150310971ab2SIngo Molnarconfig X86_DIRECT_GBPAGES
1504e5008abeSLuis R. Rodriguez	def_bool y
15052e1da13fSVlastimil Babka	depends on X86_64
15068f9ca475SIngo Molnar	---help---
150710971ab2SIngo Molnar	  Certain kernel features effectively disable kernel
150810971ab2SIngo Molnar	  linear 1 GB mappings (even if the CPU otherwise
150910971ab2SIngo Molnar	  supports them), so don't confuse the user by printing
151010971ab2SIngo Molnar	  that we have them enabled.
15119e899816SNick Piggin
15125c280cf6SThomas Gleixnerconfig X86_CPA_STATISTICS
15135c280cf6SThomas Gleixner	bool "Enable statistic for Change Page Attribute"
15145c280cf6SThomas Gleixner	depends on DEBUG_FS
15155c280cf6SThomas Gleixner	---help---
15165c280cf6SThomas Gleixner	  Expose statistics about the Change Page Attribute mechanims, which
1517a943245aSColin Ian King	  helps to determine the effectiveness of preserving large and huge
15185c280cf6SThomas Gleixner	  page mappings when mapping protections are changed.
15195c280cf6SThomas Gleixner
15207744ccdbSTom Lendackyconfig AMD_MEM_ENCRYPT
15217744ccdbSTom Lendacky	bool "AMD Secure Memory Encryption (SME) support"
15227744ccdbSTom Lendacky	depends on X86_64 && CPU_SUP_AMD
152394d49eb3SKirill A. Shutemov	select DYNAMIC_PHYSICAL_MASK
1524ce9084baSArd Biesheuvel	select ARCH_USE_MEMREMAP_PROT
15259087c375STom Lendacky	select ARCH_HAS_FORCE_DMA_UNENCRYPTED
15267744ccdbSTom Lendacky	---help---
15277744ccdbSTom Lendacky	  Say yes to enable support for the encryption of system memory.
15287744ccdbSTom Lendacky	  This requires an AMD processor that supports Secure Memory
15297744ccdbSTom Lendacky	  Encryption (SME).
15307744ccdbSTom Lendacky
15317744ccdbSTom Lendackyconfig AMD_MEM_ENCRYPT_ACTIVE_BY_DEFAULT
15327744ccdbSTom Lendacky	bool "Activate AMD Secure Memory Encryption (SME) by default"
15337744ccdbSTom Lendacky	default y
15347744ccdbSTom Lendacky	depends on AMD_MEM_ENCRYPT
15357744ccdbSTom Lendacky	---help---
15367744ccdbSTom Lendacky	  Say yes to have system memory encrypted by default if running on
15377744ccdbSTom Lendacky	  an AMD processor that supports Secure Memory Encryption (SME).
15387744ccdbSTom Lendacky
15397744ccdbSTom Lendacky	  If set to Y, then the encryption of system memory can be
15407744ccdbSTom Lendacky	  deactivated with the mem_encrypt=off command line option.
15417744ccdbSTom Lendacky
15427744ccdbSTom Lendacky	  If set to N, then the encryption of system memory can be
15437744ccdbSTom Lendacky	  activated with the mem_encrypt=on command line option.
15447744ccdbSTom Lendacky
1545506f1d07SSam Ravnborg# Common NUMA Features
1546506f1d07SSam Ravnborgconfig NUMA
1547fd51b2d7SKOSAKI Motohiro	bool "Numa Memory Allocation and Scheduler Support"
1548506f1d07SSam Ravnborg	depends on SMP
1549b5660ba7SH. Peter Anvin	depends on X86_64 || (X86_32 && HIGHMEM64G && X86_BIGSMP)
1550b5660ba7SH. Peter Anvin	default y if X86_BIGSMP
15518f9ca475SIngo Molnar	---help---
1552506f1d07SSam Ravnborg	  Enable NUMA (Non Uniform Memory Access) support.
1553fd51b2d7SKOSAKI Motohiro
1554506f1d07SSam Ravnborg	  The kernel will try to allocate memory used by a CPU on the
1555506f1d07SSam Ravnborg	  local memory controller of the CPU and add some more
1556506f1d07SSam Ravnborg	  NUMA awareness to the kernel.
1557506f1d07SSam Ravnborg
1558c280ea5eSIngo Molnar	  For 64-bit this is recommended if the system is Intel Core i7
1559fd51b2d7SKOSAKI Motohiro	  (or later), AMD Opteron, or EM64T NUMA.
1560fd51b2d7SKOSAKI Motohiro
1561b5660ba7SH. Peter Anvin	  For 32-bit this is only needed if you boot a 32-bit
15627cf6c945SDavid Rientjes	  kernel on a 64-bit NUMA platform.
1563fd51b2d7SKOSAKI Motohiro
1564fd51b2d7SKOSAKI Motohiro	  Otherwise, you should say N.
1565506f1d07SSam Ravnborg
1566eec1d4faSHans Rosenfeldconfig AMD_NUMA
15673c2362e6SHarvey Harrison	def_bool y
15683c2362e6SHarvey Harrison	prompt "Old style AMD Opteron NUMA detection"
15695da0ef9aSTejun Heo	depends on X86_64 && NUMA && PCI
15708f9ca475SIngo Molnar	---help---
1571eec1d4faSHans Rosenfeld	  Enable AMD NUMA node topology detection.  You should say Y here if
1572eec1d4faSHans Rosenfeld	  you have a multi processor AMD system. This uses an old method to
1573eec1d4faSHans Rosenfeld	  read the NUMA configuration directly from the builtin Northbridge
1574eec1d4faSHans Rosenfeld	  of Opteron. It is recommended to use X86_64_ACPI_NUMA instead,
1575eec1d4faSHans Rosenfeld	  which also takes priority if both are compiled in.
1576506f1d07SSam Ravnborg
1577506f1d07SSam Ravnborgconfig X86_64_ACPI_NUMA
15783c2362e6SHarvey Harrison	def_bool y
15793c2362e6SHarvey Harrison	prompt "ACPI NUMA detection"
1580506f1d07SSam Ravnborg	depends on X86_64 && NUMA && ACPI && PCI
1581506f1d07SSam Ravnborg	select ACPI_NUMA
15828f9ca475SIngo Molnar	---help---
1583506f1d07SSam Ravnborg	  Enable ACPI SRAT based node topology detection.
1584506f1d07SSam Ravnborg
15856ec6e0d9SSuresh Siddha# Some NUMA nodes have memory ranges that span
15866ec6e0d9SSuresh Siddha# other nodes.  Even though a pfn is valid and
15876ec6e0d9SSuresh Siddha# between a node's start and end pfns, it may not
15886ec6e0d9SSuresh Siddha# reside on that node.  See memmap_init_zone()
15896ec6e0d9SSuresh Siddha# for details.
15906ec6e0d9SSuresh Siddhaconfig NODES_SPAN_OTHER_NODES
15916ec6e0d9SSuresh Siddha	def_bool y
15926ec6e0d9SSuresh Siddha	depends on X86_64_ACPI_NUMA
15936ec6e0d9SSuresh Siddha
1594506f1d07SSam Ravnborgconfig NUMA_EMU
1595506f1d07SSam Ravnborg	bool "NUMA emulation"
15961b7e03efSTejun Heo	depends on NUMA
15978f9ca475SIngo Molnar	---help---
1598506f1d07SSam Ravnborg	  Enable NUMA emulation. A flat machine will be split
1599506f1d07SSam Ravnborg	  into virtual nodes when booted with "numa=fake=N", where N is the
1600506f1d07SSam Ravnborg	  number of nodes. This is only useful for debugging.
1601506f1d07SSam Ravnborg
1602506f1d07SSam Ravnborgconfig NODES_SHIFT
1603d25e26b6SLinus Torvalds	int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP
160451591e31SDavid Rientjes	range 1 10
160551591e31SDavid Rientjes	default "10" if MAXSMP
1606506f1d07SSam Ravnborg	default "6" if X86_64
1607506f1d07SSam Ravnborg	default "3"
1608506f1d07SSam Ravnborg	depends on NEED_MULTIPLE_NODES
16098f9ca475SIngo Molnar	---help---
16101184dc2fSMike Travis	  Specify the maximum number of NUMA Nodes available on the target
1611692105b8SMatt LaPlante	  system.  Increases memory reserved to accommodate various tables.
1612506f1d07SSam Ravnborg
1613506f1d07SSam Ravnborgconfig ARCH_HAVE_MEMORY_PRESENT
16143c2362e6SHarvey Harrison	def_bool y
1615506f1d07SSam Ravnborg	depends on X86_32 && DISCONTIGMEM
1616506f1d07SSam Ravnborg
1617506f1d07SSam Ravnborgconfig ARCH_FLATMEM_ENABLE
1618506f1d07SSam Ravnborg	def_bool y
16193b16651fSTejun Heo	depends on X86_32 && !NUMA
1620506f1d07SSam Ravnborg
1621506f1d07SSam Ravnborgconfig ARCH_DISCONTIGMEM_ENABLE
16222792107dSMike Rapoport	def_bool n
1623b263295dSChristoph Lameter	depends on NUMA && X86_32
16242792107dSMike Rapoport	depends on BROKEN
1625b263295dSChristoph Lameter
1626506f1d07SSam Ravnborgconfig ARCH_SPARSEMEM_ENABLE
1627506f1d07SSam Ravnborg	def_bool y
16286ea30386SKees Cook	depends on X86_64 || NUMA || X86_32 || X86_32_NON_STANDARD
1629506f1d07SSam Ravnborg	select SPARSEMEM_STATIC if X86_32
1630506f1d07SSam Ravnborg	select SPARSEMEM_VMEMMAP_ENABLE if X86_64
1631506f1d07SSam Ravnborg
16323b16651fSTejun Heoconfig ARCH_SPARSEMEM_DEFAULT
16336ad57f7fSMike Rapoport	def_bool X86_64 || (NUMA && X86_32)
16343b16651fSTejun Heo
1635506f1d07SSam Ravnborgconfig ARCH_SELECT_MEMORY_MODEL
1636506f1d07SSam Ravnborg	def_bool y
1637b263295dSChristoph Lameter	depends on ARCH_SPARSEMEM_ENABLE
1638506f1d07SSam Ravnborg
1639506f1d07SSam Ravnborgconfig ARCH_MEMORY_PROBE
1640a0842b70SToshi Kani	bool "Enable sysfs memory/probe interface"
16413120e25eSJan Beulich	depends on X86_64 && MEMORY_HOTPLUG
1642a0842b70SToshi Kani	help
1643a0842b70SToshi Kani	  This option enables a sysfs memory/probe interface for testing.
1644cb1aaebeSMauro Carvalho Chehab	  See Documentation/admin-guide/mm/memory-hotplug.rst for more information.
1645a0842b70SToshi Kani	  If you are unsure how to answer this question, answer N.
1646506f1d07SSam Ravnborg
16473b16651fSTejun Heoconfig ARCH_PROC_KCORE_TEXT
16483b16651fSTejun Heo	def_bool y
16493b16651fSTejun Heo	depends on X86_64 && PROC_KCORE
16503b16651fSTejun Heo
1651a29815a3SAvi Kivityconfig ILLEGAL_POINTER_VALUE
1652a29815a3SAvi Kivity       hex
1653a29815a3SAvi Kivity       default 0 if X86_32
1654a29815a3SAvi Kivity       default 0xdead000000000000 if X86_64
1655a29815a3SAvi Kivity
16567a67832cSDan Williamsconfig X86_PMEM_LEGACY_DEVICE
16577a67832cSDan Williams	bool
16587a67832cSDan Williams
1659ec776ef6SChristoph Hellwigconfig X86_PMEM_LEGACY
16607a67832cSDan Williams	tristate "Support non-standard NVDIMMs and ADR protected memory"
16619f53f9faSDan Williams	depends on PHYS_ADDR_T_64BIT
16629f53f9faSDan Williams	depends on BLK_DEV
16637a67832cSDan Williams	select X86_PMEM_LEGACY_DEVICE
16649f53f9faSDan Williams	select LIBNVDIMM
1665ec776ef6SChristoph Hellwig	help
1666ec776ef6SChristoph Hellwig	  Treat memory marked using the non-standard e820 type of 12 as used
1667ec776ef6SChristoph Hellwig	  by the Intel Sandy Bridge-EP reference BIOS as protected memory.
1668ec776ef6SChristoph Hellwig	  The kernel will offer these regions to the 'pmem' driver so
1669ec776ef6SChristoph Hellwig	  they can be used for persistent storage.
1670ec776ef6SChristoph Hellwig
1671ec776ef6SChristoph Hellwig	  Say Y if unsure.
1672ec776ef6SChristoph Hellwig
1673506f1d07SSam Ravnborgconfig HIGHPTE
1674506f1d07SSam Ravnborg	bool "Allocate 3rd-level pagetables from highmem"
16756fc108a0SJan Beulich	depends on HIGHMEM
16768f9ca475SIngo Molnar	---help---
1677506f1d07SSam Ravnborg	  The VM uses one page table entry for each page of physical memory.
1678506f1d07SSam Ravnborg	  For systems with a lot of RAM, this can be wasteful of precious
1679506f1d07SSam Ravnborg	  low memory.  Setting this option will put user-space page table
1680506f1d07SSam Ravnborg	  entries in high memory.
1681506f1d07SSam Ravnborg
16829f077871SJeremy Fitzhardingeconfig X86_CHECK_BIOS_CORRUPTION
16839f077871SJeremy Fitzhardinge	bool "Check for low memory corruption"
16848f9ca475SIngo Molnar	---help---
16859f077871SJeremy Fitzhardinge	  Periodically check for memory corruption in low memory, which
16869f077871SJeremy Fitzhardinge	  is suspected to be caused by BIOS.  Even when enabled in the
16879f077871SJeremy Fitzhardinge	  configuration, it is disabled at runtime.  Enable it by
16889f077871SJeremy Fitzhardinge	  setting "memory_corruption_check=1" on the kernel command
16899f077871SJeremy Fitzhardinge	  line.  By default it scans the low 64k of memory every 60
16909f077871SJeremy Fitzhardinge	  seconds; see the memory_corruption_check_size and
16919f077871SJeremy Fitzhardinge	  memory_corruption_check_period parameters in
16928c27ceffSMauro Carvalho Chehab	  Documentation/admin-guide/kernel-parameters.rst to adjust this.
16939f077871SJeremy Fitzhardinge
16949f077871SJeremy Fitzhardinge	  When enabled with the default parameters, this option has
16959f077871SJeremy Fitzhardinge	  almost no overhead, as it reserves a relatively small amount
16969f077871SJeremy Fitzhardinge	  of memory and scans it infrequently.  It both detects corruption
16979f077871SJeremy Fitzhardinge	  and prevents it from affecting the running system.
16989f077871SJeremy Fitzhardinge
16999f077871SJeremy Fitzhardinge	  It is, however, intended as a diagnostic tool; if repeatable
17009f077871SJeremy Fitzhardinge	  BIOS-originated corruption always affects the same memory,
17019f077871SJeremy Fitzhardinge	  you can use memmap= to prevent the kernel from using that
17029f077871SJeremy Fitzhardinge	  memory.
17039f077871SJeremy Fitzhardinge
1704c885df50SJeremy Fitzhardingeconfig X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK
1705c885df50SJeremy Fitzhardinge	bool "Set the default setting of memory_corruption_check"
1706c885df50SJeremy Fitzhardinge	depends on X86_CHECK_BIOS_CORRUPTION
1707c885df50SJeremy Fitzhardinge	default y
17088f9ca475SIngo Molnar	---help---
1709c885df50SJeremy Fitzhardinge	  Set whether the default state of memory_corruption_check is
1710c885df50SJeremy Fitzhardinge	  on or off.
1711c885df50SJeremy Fitzhardinge
17129ea77bdbSH. Peter Anvinconfig X86_RESERVE_LOW
1713d0cd7425SH. Peter Anvin	int "Amount of low memory, in kilobytes, to reserve for the BIOS"
1714d0cd7425SH. Peter Anvin	default 64
1715d0cd7425SH. Peter Anvin	range 4 640
17168f9ca475SIngo Molnar	---help---
1717d0cd7425SH. Peter Anvin	  Specify the amount of low memory to reserve for the BIOS.
1718fc381519SIngo Molnar
1719d0cd7425SH. Peter Anvin	  The first page contains BIOS data structures that the kernel
1720d0cd7425SH. Peter Anvin	  must not use, so that page must always be reserved.
1721fc381519SIngo Molnar
1722d0cd7425SH. Peter Anvin	  By default we reserve the first 64K of physical RAM, as a
1723d0cd7425SH. Peter Anvin	  number of BIOSes are known to corrupt that memory range
1724d0cd7425SH. Peter Anvin	  during events such as suspend/resume or monitor cable
1725d0cd7425SH. Peter Anvin	  insertion, so it must not be used by the kernel.
1726fc381519SIngo Molnar
1727d0cd7425SH. Peter Anvin	  You can set this to 4 if you are absolutely sure that you
1728d0cd7425SH. Peter Anvin	  trust the BIOS to get all its memory reservations and usages
1729d0cd7425SH. Peter Anvin	  right.  If you know your BIOS have problems beyond the
1730d0cd7425SH. Peter Anvin	  default 64K area, you can set this to 640 to avoid using the
1731d0cd7425SH. Peter Anvin	  entire low memory range.
1732d0cd7425SH. Peter Anvin
1733d0cd7425SH. Peter Anvin	  If you have doubts about the BIOS (e.g. suspend/resume does
1734d0cd7425SH. Peter Anvin	  not work or there's kernel crashes after certain hardware
1735d0cd7425SH. Peter Anvin	  hotplug events) then you might want to enable
1736d0cd7425SH. Peter Anvin	  X86_CHECK_BIOS_CORRUPTION=y to allow the kernel to check
1737d0cd7425SH. Peter Anvin	  typical corruption patterns.
1738d0cd7425SH. Peter Anvin
1739d0cd7425SH. Peter Anvin	  Leave this to the default value of 64 if you are unsure.
1740fc381519SIngo Molnar
1741506f1d07SSam Ravnborgconfig MATH_EMULATION
1742506f1d07SSam Ravnborg	bool
1743a5b9e5a2SAndy Lutomirski	depends on MODIFY_LDT_SYSCALL
174487d6021bSArnd Bergmann	prompt "Math emulation" if X86_32 && (M486SX || MELAN)
1745506f1d07SSam Ravnborg	---help---
1746506f1d07SSam Ravnborg	  Linux can emulate a math coprocessor (used for floating point
1747506f1d07SSam Ravnborg	  operations) if you don't have one. 486DX and Pentium processors have
1748506f1d07SSam Ravnborg	  a math coprocessor built in, 486SX and 386 do not, unless you added
1749506f1d07SSam Ravnborg	  a 487DX or 387, respectively. (The messages during boot time can
1750506f1d07SSam Ravnborg	  give you some hints here ["man dmesg"].) Everyone needs either a
1751506f1d07SSam Ravnborg	  coprocessor or this emulation.
1752506f1d07SSam Ravnborg
1753506f1d07SSam Ravnborg	  If you don't have a math coprocessor, you need to say Y here; if you
1754506f1d07SSam Ravnborg	  say Y here even though you have a coprocessor, the coprocessor will
1755506f1d07SSam Ravnborg	  be used nevertheless. (This behavior can be changed with the kernel
1756506f1d07SSam Ravnborg	  command line option "no387", which comes handy if your coprocessor
1757506f1d07SSam Ravnborg	  is broken. Try "man bootparam" or see the documentation of your boot
1758506f1d07SSam Ravnborg	  loader (lilo or loadlin) about how to pass options to the kernel at
1759506f1d07SSam Ravnborg	  boot time.) This means that it is a good idea to say Y here if you
1760506f1d07SSam Ravnborg	  intend to use this kernel on different machines.
1761506f1d07SSam Ravnborg
1762506f1d07SSam Ravnborg	  More information about the internals of the Linux math coprocessor
1763506f1d07SSam Ravnborg	  emulation can be found in <file:arch/x86/math-emu/README>.
1764506f1d07SSam Ravnborg
1765506f1d07SSam Ravnborg	  If you are not sure, say Y; apart from resulting in a 66 KB bigger
1766506f1d07SSam Ravnborg	  kernel, it won't hurt.
1767506f1d07SSam Ravnborg
1768506f1d07SSam Ravnborgconfig MTRR
17696fc108a0SJan Beulich	def_bool y
17706a108a14SDavid Rientjes	prompt "MTRR (Memory Type Range Register) support" if EXPERT
1771506f1d07SSam Ravnborg	---help---
1772506f1d07SSam Ravnborg	  On Intel P6 family processors (Pentium Pro, Pentium II and later)
1773506f1d07SSam Ravnborg	  the Memory Type Range Registers (MTRRs) may be used to control
1774506f1d07SSam Ravnborg	  processor access to memory ranges. This is most useful if you have
1775506f1d07SSam Ravnborg	  a video (VGA) card on a PCI or AGP bus. Enabling write-combining
1776506f1d07SSam Ravnborg	  allows bus write transfers to be combined into a larger transfer
1777506f1d07SSam Ravnborg	  before bursting over the PCI/AGP bus. This can increase performance
1778506f1d07SSam Ravnborg	  of image write operations 2.5 times or more. Saying Y here creates a
1779506f1d07SSam Ravnborg	  /proc/mtrr file which may be used to manipulate your processor's
1780506f1d07SSam Ravnborg	  MTRRs. Typically the X server should use this.
1781506f1d07SSam Ravnborg
1782506f1d07SSam Ravnborg	  This code has a reasonably generic interface so that similar
1783506f1d07SSam Ravnborg	  control registers on other processors can be easily supported
1784506f1d07SSam Ravnborg	  as well:
1785506f1d07SSam Ravnborg
1786506f1d07SSam Ravnborg	  The Cyrix 6x86, 6x86MX and M II processors have Address Range
1787506f1d07SSam Ravnborg	  Registers (ARRs) which provide a similar functionality to MTRRs. For
1788506f1d07SSam Ravnborg	  these, the ARRs are used to emulate the MTRRs.
1789506f1d07SSam Ravnborg	  The AMD K6-2 (stepping 8 and above) and K6-3 processors have two
1790506f1d07SSam Ravnborg	  MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing
1791506f1d07SSam Ravnborg	  write-combining. All of these processors are supported by this code
1792506f1d07SSam Ravnborg	  and it makes sense to say Y here if you have one of them.
1793506f1d07SSam Ravnborg
1794506f1d07SSam Ravnborg	  Saying Y here also fixes a problem with buggy SMP BIOSes which only
1795506f1d07SSam Ravnborg	  set the MTRRs for the boot CPU and not for the secondary CPUs. This
1796506f1d07SSam Ravnborg	  can lead to all sorts of problems, so it's good to say Y here.
1797506f1d07SSam Ravnborg
1798506f1d07SSam Ravnborg	  You can safely say Y even if your machine doesn't have MTRRs, you'll
1799506f1d07SSam Ravnborg	  just add about 9 KB to your kernel.
1800506f1d07SSam Ravnborg
1801cb1aaebeSMauro Carvalho Chehab	  See <file:Documentation/x86/mtrr.rst> for more information.
1802506f1d07SSam Ravnborg
180395ffa243SYinghai Luconfig MTRR_SANITIZER
18042ffb3501SYinghai Lu	def_bool y
180595ffa243SYinghai Lu	prompt "MTRR cleanup support"
180695ffa243SYinghai Lu	depends on MTRR
18078f9ca475SIngo Molnar	---help---
1808aba3728cSThomas Gleixner	  Convert MTRR layout from continuous to discrete, so X drivers can
1809aba3728cSThomas Gleixner	  add writeback entries.
181095ffa243SYinghai Lu
1811aba3728cSThomas Gleixner	  Can be disabled with disable_mtrr_cleanup on the kernel command line.
1812692105b8SMatt LaPlante	  The largest mtrr entry size for a continuous block can be set with
1813aba3728cSThomas Gleixner	  mtrr_chunk_size.
181495ffa243SYinghai Lu
18152ffb3501SYinghai Lu	  If unsure, say Y.
181695ffa243SYinghai Lu
181795ffa243SYinghai Luconfig MTRR_SANITIZER_ENABLE_DEFAULT
1818f5098d62SYinghai Lu	int "MTRR cleanup enable value (0-1)"
1819f5098d62SYinghai Lu	range 0 1
1820f5098d62SYinghai Lu	default "0"
182195ffa243SYinghai Lu	depends on MTRR_SANITIZER
18228f9ca475SIngo Molnar	---help---
1823f5098d62SYinghai Lu	  Enable mtrr cleanup default value
182495ffa243SYinghai Lu
182512031a62SYinghai Luconfig MTRR_SANITIZER_SPARE_REG_NR_DEFAULT
182612031a62SYinghai Lu	int "MTRR cleanup spare reg num (0-7)"
182712031a62SYinghai Lu	range 0 7
182812031a62SYinghai Lu	default "1"
182912031a62SYinghai Lu	depends on MTRR_SANITIZER
18308f9ca475SIngo Molnar	---help---
183112031a62SYinghai Lu	  mtrr cleanup spare entries default, it can be changed via
1832aba3728cSThomas Gleixner	  mtrr_spare_reg_nr=N on the kernel command line.
183312031a62SYinghai Lu
18342e5d9c85Svenkatesh.pallipadi@intel.comconfig X86_PAT
18356fc108a0SJan Beulich	def_bool y
18366a108a14SDavid Rientjes	prompt "x86 PAT support" if EXPERT
18372a8a2719SIngo Molnar	depends on MTRR
18388f9ca475SIngo Molnar	---help---
18392e5d9c85Svenkatesh.pallipadi@intel.com	  Use PAT attributes to setup page level cache control.
1840042b78e4SVenki Pallipadi
18412e5d9c85Svenkatesh.pallipadi@intel.com	  PATs are the modern equivalents of MTRRs and are much more
18422e5d9c85Svenkatesh.pallipadi@intel.com	  flexible than MTRRs.
18432e5d9c85Svenkatesh.pallipadi@intel.com
18442e5d9c85Svenkatesh.pallipadi@intel.com	  Say N here if you see bootup problems (boot crash, boot hang,
1845042b78e4SVenki Pallipadi	  spontaneous reboots) or a non-working video driver.
18462e5d9c85Svenkatesh.pallipadi@intel.com
18472e5d9c85Svenkatesh.pallipadi@intel.com	  If unsure, say Y.
18482e5d9c85Svenkatesh.pallipadi@intel.com
184946cf98cdSVenkatesh Pallipadiconfig ARCH_USES_PG_UNCACHED
185046cf98cdSVenkatesh Pallipadi	def_bool y
185146cf98cdSVenkatesh Pallipadi	depends on X86_PAT
185246cf98cdSVenkatesh Pallipadi
1853628c6246SH. Peter Anvinconfig ARCH_RANDOM
1854628c6246SH. Peter Anvin	def_bool y
1855628c6246SH. Peter Anvin	prompt "x86 architectural random number generator" if EXPERT
1856628c6246SH. Peter Anvin	---help---
1857628c6246SH. Peter Anvin	  Enable the x86 architectural RDRAND instruction
1858628c6246SH. Peter Anvin	  (Intel Bull Mountain technology) to generate random numbers.
1859628c6246SH. Peter Anvin	  If supported, this is a high bandwidth, cryptographically
1860628c6246SH. Peter Anvin	  secure hardware random number generator.
1861628c6246SH. Peter Anvin
186251ae4a2dSH. Peter Anvinconfig X86_SMAP
186351ae4a2dSH. Peter Anvin	def_bool y
186451ae4a2dSH. Peter Anvin	prompt "Supervisor Mode Access Prevention" if EXPERT
186551ae4a2dSH. Peter Anvin	---help---
186651ae4a2dSH. Peter Anvin	  Supervisor Mode Access Prevention (SMAP) is a security
186751ae4a2dSH. Peter Anvin	  feature in newer Intel processors.  There is a small
186851ae4a2dSH. Peter Anvin	  performance cost if this enabled and turned on; there is
186951ae4a2dSH. Peter Anvin	  also a small increase in the kernel size if this is enabled.
187051ae4a2dSH. Peter Anvin
187151ae4a2dSH. Peter Anvin	  If unsure, say Y.
187251ae4a2dSH. Peter Anvin
1873b971880fSBabu Mogerconfig X86_UMIP
1874796ebc81SRicardo Neri	def_bool y
1875b971880fSBabu Moger	depends on CPU_SUP_INTEL || CPU_SUP_AMD
1876b971880fSBabu Moger	prompt "User Mode Instruction Prevention" if EXPERT
1877aa35f896SRicardo Neri	---help---
1878b971880fSBabu Moger	  User Mode Instruction Prevention (UMIP) is a security feature in
1879b971880fSBabu Moger	  some x86 processors. If enabled, a general protection fault is
1880b971880fSBabu Moger	  issued if the SGDT, SLDT, SIDT, SMSW or STR instructions are
1881b971880fSBabu Moger	  executed in user mode. These instructions unnecessarily expose
1882b971880fSBabu Moger	  information about the hardware state.
1883796ebc81SRicardo Neri
1884796ebc81SRicardo Neri	  The vast majority of applications do not use these instructions.
1885796ebc81SRicardo Neri	  For the very few that do, software emulation is provided in
1886796ebc81SRicardo Neri	  specific cases in protected and virtual-8086 modes. Emulated
1887796ebc81SRicardo Neri	  results are dummy.
1888aa35f896SRicardo Neri
188972e9b5feSDave Hansenconfig X86_INTEL_MPX
189072e9b5feSDave Hansen	prompt "Intel MPX (Memory Protection Extensions)"
189172e9b5feSDave Hansen	def_bool n
1892df3735c5SRik van Riel	# Note: only available in 64-bit mode due to VMA flags shortage
1893df3735c5SRik van Riel	depends on CPU_SUP_INTEL && X86_64
1894df3735c5SRik van Riel	select ARCH_USES_HIGH_VMA_FLAGS
189572e9b5feSDave Hansen	---help---
189672e9b5feSDave Hansen	  MPX provides hardware features that can be used in
189772e9b5feSDave Hansen	  conjunction with compiler-instrumented code to check
189872e9b5feSDave Hansen	  memory references.  It is designed to detect buffer
189972e9b5feSDave Hansen	  overflow or underflow bugs.
190072e9b5feSDave Hansen
190172e9b5feSDave Hansen	  This option enables running applications which are
190272e9b5feSDave Hansen	  instrumented or otherwise use MPX.  It does not use MPX
190372e9b5feSDave Hansen	  itself inside the kernel or to protect the kernel
190472e9b5feSDave Hansen	  against bad memory references.
190572e9b5feSDave Hansen
190672e9b5feSDave Hansen	  Enabling this option will make the kernel larger:
190772e9b5feSDave Hansen	  ~8k of kernel text and 36 bytes of data on a 64-bit
190872e9b5feSDave Hansen	  defconfig.  It adds a long to the 'mm_struct' which
190972e9b5feSDave Hansen	  will increase the kernel memory overhead of each
191072e9b5feSDave Hansen	  process and adds some branches to paths used during
191172e9b5feSDave Hansen	  exec() and munmap().
191272e9b5feSDave Hansen
1913cb1aaebeSMauro Carvalho Chehab	  For details, see Documentation/x86/intel_mpx.rst
191472e9b5feSDave Hansen
191572e9b5feSDave Hansen	  If unsure, say N.
191672e9b5feSDave Hansen
191735e97790SDave Hansenconfig X86_INTEL_MEMORY_PROTECTION_KEYS
1918284244a9SDave Hansen	prompt "Intel Memory Protection Keys"
191935e97790SDave Hansen	def_bool y
1920284244a9SDave Hansen	# Note: only available in 64-bit mode
192135e97790SDave Hansen	depends on CPU_SUP_INTEL && X86_64
192252c8e601SIngo Molnar	select ARCH_USES_HIGH_VMA_FLAGS
192352c8e601SIngo Molnar	select ARCH_HAS_PKEYS
1924284244a9SDave Hansen	---help---
1925284244a9SDave Hansen	  Memory Protection Keys provides a mechanism for enforcing
1926284244a9SDave Hansen	  page-based protections, but without requiring modification of the
1927284244a9SDave Hansen	  page tables when an application changes protection domains.
1928284244a9SDave Hansen
19291eecbcdcSMauro Carvalho Chehab	  For details, see Documentation/core-api/protection-keys.rst
1930284244a9SDave Hansen
1931284244a9SDave Hansen	  If unsure, say y.
193235e97790SDave Hansen
1933db616173SMichal Hockochoice
1934db616173SMichal Hocko	prompt "TSX enable mode"
1935db616173SMichal Hocko	depends on CPU_SUP_INTEL
1936db616173SMichal Hocko	default X86_INTEL_TSX_MODE_OFF
1937db616173SMichal Hocko	help
1938db616173SMichal Hocko	  Intel's TSX (Transactional Synchronization Extensions) feature
1939db616173SMichal Hocko	  allows to optimize locking protocols through lock elision which
1940db616173SMichal Hocko	  can lead to a noticeable performance boost.
1941db616173SMichal Hocko
1942db616173SMichal Hocko	  On the other hand it has been shown that TSX can be exploited
1943db616173SMichal Hocko	  to form side channel attacks (e.g. TAA) and chances are there
1944db616173SMichal Hocko	  will be more of those attacks discovered in the future.
1945db616173SMichal Hocko
1946db616173SMichal Hocko	  Therefore TSX is not enabled by default (aka tsx=off). An admin
1947db616173SMichal Hocko	  might override this decision by tsx=on the command line parameter.
1948db616173SMichal Hocko	  Even with TSX enabled, the kernel will attempt to enable the best
1949db616173SMichal Hocko	  possible TAA mitigation setting depending on the microcode available
1950db616173SMichal Hocko	  for the particular machine.
1951db616173SMichal Hocko
1952db616173SMichal Hocko	  This option allows to set the default tsx mode between tsx=on, =off
1953db616173SMichal Hocko	  and =auto. See Documentation/admin-guide/kernel-parameters.txt for more
1954db616173SMichal Hocko	  details.
1955db616173SMichal Hocko
1956db616173SMichal Hocko	  Say off if not sure, auto if TSX is in use but it should be used on safe
1957db616173SMichal Hocko	  platforms or on if TSX is in use and the security aspect of tsx is not
1958db616173SMichal Hocko	  relevant.
1959db616173SMichal Hocko
1960db616173SMichal Hockoconfig X86_INTEL_TSX_MODE_OFF
1961db616173SMichal Hocko	bool "off"
1962db616173SMichal Hocko	help
1963db616173SMichal Hocko	  TSX is disabled if possible - equals to tsx=off command line parameter.
1964db616173SMichal Hocko
1965db616173SMichal Hockoconfig X86_INTEL_TSX_MODE_ON
1966db616173SMichal Hocko	bool "on"
1967db616173SMichal Hocko	help
1968db616173SMichal Hocko	  TSX is always enabled on TSX capable HW - equals the tsx=on command
1969db616173SMichal Hocko	  line parameter.
1970db616173SMichal Hocko
1971db616173SMichal Hockoconfig X86_INTEL_TSX_MODE_AUTO
1972db616173SMichal Hocko	bool "auto"
1973db616173SMichal Hocko	help
1974db616173SMichal Hocko	  TSX is enabled on TSX capable HW that is believed to be safe against
1975db616173SMichal Hocko	  side channel attacks- equals the tsx=auto command line parameter.
1976db616173SMichal Hockoendchoice
1977db616173SMichal Hocko
1978506f1d07SSam Ravnborgconfig EFI
19799ba16087SJan Beulich	bool "EFI runtime service support"
19805b83683fSHuang, Ying	depends on ACPI
1981f6ce5002SSergey Vlasov	select UCS2_STRING
1982022ee6c5SArd Biesheuvel	select EFI_RUNTIME_WRAPPERS
1983506f1d07SSam Ravnborg	---help---
19848b2cb7a8SHuang, Ying	  This enables the kernel to use EFI runtime services that are
1985506f1d07SSam Ravnborg	  available (such as the EFI variable services).
1986506f1d07SSam Ravnborg
19878b2cb7a8SHuang, Ying	  This option is only useful on systems that have EFI firmware.
19888b2cb7a8SHuang, Ying	  In addition, you should use the latest ELILO loader available
19898b2cb7a8SHuang, Ying	  at <http://elilo.sourceforge.net> in order to take advantage
19908b2cb7a8SHuang, Ying	  of EFI runtime services. However, even with this option, the
19918b2cb7a8SHuang, Ying	  resultant kernel should continue to boot on existing non-EFI
19928b2cb7a8SHuang, Ying	  platforms.
1993506f1d07SSam Ravnborg
1994291f3632SMatt Flemingconfig EFI_STUB
1995291f3632SMatt Fleming       bool "EFI stub support"
1996b16d8c23SMatt Fleming       depends on EFI && !X86_USE_3DNOW
19977b2a583aSMatt Fleming       select RELOCATABLE
1998291f3632SMatt Fleming       ---help---
1999291f3632SMatt Fleming          This kernel feature allows a bzImage to be loaded directly
2000291f3632SMatt Fleming	  by EFI firmware without the use of a bootloader.
2001291f3632SMatt Fleming
20024f4cfa6cSMauro Carvalho Chehab	  See Documentation/admin-guide/efi-stub.rst for more information.
20030c759662SMatt Fleming
20047d453eeeSMatt Flemingconfig EFI_MIXED
20057d453eeeSMatt Fleming	bool "EFI mixed-mode support"
20067d453eeeSMatt Fleming	depends on EFI_STUB && X86_64
20077d453eeeSMatt Fleming	---help---
20087d453eeeSMatt Fleming	   Enabling this feature allows a 64-bit kernel to be booted
20097d453eeeSMatt Fleming	   on a 32-bit firmware, provided that your CPU supports 64-bit
20107d453eeeSMatt Fleming	   mode.
20117d453eeeSMatt Fleming
20127d453eeeSMatt Fleming	   Note that it is not possible to boot a mixed-mode enabled
20137d453eeeSMatt Fleming	   kernel via the EFI boot stub - a bootloader that supports
20147d453eeeSMatt Fleming	   the EFI handover protocol must be used.
20157d453eeeSMatt Fleming
20167d453eeeSMatt Fleming	   If unsure, say N.
20177d453eeeSMatt Fleming
2018506f1d07SSam Ravnborgconfig SECCOMP
20193c2362e6SHarvey Harrison	def_bool y
20203c2362e6SHarvey Harrison	prompt "Enable seccomp to safely compute untrusted bytecode"
20218f9ca475SIngo Molnar	---help---
2022506f1d07SSam Ravnborg	  This kernel feature is useful for number crunching applications
2023506f1d07SSam Ravnborg	  that may need to compute untrusted bytecode during their
2024506f1d07SSam Ravnborg	  execution. By using pipes or other transports made available to
2025506f1d07SSam Ravnborg	  the process as file descriptors supporting the read/write
2026506f1d07SSam Ravnborg	  syscalls, it's possible to isolate those applications in
2027506f1d07SSam Ravnborg	  their own address space using seccomp. Once seccomp is
20289c0bbee8SAlexey Dobriyan	  enabled via prctl(PR_SET_SECCOMP), it cannot be disabled
2029506f1d07SSam Ravnborg	  and the task is only allowed to execute a few safe syscalls
2030506f1d07SSam Ravnborg	  defined by each seccomp mode.
2031506f1d07SSam Ravnborg
2032506f1d07SSam Ravnborg	  If unsure, say Y. Only embedded should say N here.
2033506f1d07SSam Ravnborg
20348636a1f9SMasahiro Yamadasource "kernel/Kconfig.hz"
2035506f1d07SSam Ravnborg
2036506f1d07SSam Ravnborgconfig KEXEC
2037506f1d07SSam Ravnborg	bool "kexec system call"
20382965faa5SDave Young	select KEXEC_CORE
20398f9ca475SIngo Molnar	---help---
2040506f1d07SSam Ravnborg	  kexec is a system call that implements the ability to shutdown your
2041506f1d07SSam Ravnborg	  current kernel, and to start another kernel.  It is like a reboot
2042506f1d07SSam Ravnborg	  but it is independent of the system firmware.   And like a reboot
2043506f1d07SSam Ravnborg	  you can start any kernel with it, not just Linux.
2044506f1d07SSam Ravnborg
2045506f1d07SSam Ravnborg	  The name comes from the similarity to the exec system call.
2046506f1d07SSam Ravnborg
2047506f1d07SSam Ravnborg	  It is an ongoing process to be certain the hardware in a machine
2048506f1d07SSam Ravnborg	  is properly shutdown, so do not be surprised if this code does not
2049bf220695SGeert Uytterhoeven	  initially work for you.  As of this writing the exact hardware
2050bf220695SGeert Uytterhoeven	  interface is strongly in flux, so no good recommendation can be
2051bf220695SGeert Uytterhoeven	  made.
2052506f1d07SSam Ravnborg
205374ca317cSVivek Goyalconfig KEXEC_FILE
205474ca317cSVivek Goyal	bool "kexec file based system call"
20552965faa5SDave Young	select KEXEC_CORE
205674ca317cSVivek Goyal	select BUILD_BIN2C
205774ca317cSVivek Goyal	depends on X86_64
205874ca317cSVivek Goyal	depends on CRYPTO=y
205974ca317cSVivek Goyal	depends on CRYPTO_SHA256=y
206074ca317cSVivek Goyal	---help---
206174ca317cSVivek Goyal	  This is new version of kexec system call. This system call is
206274ca317cSVivek Goyal	  file based and takes file descriptors as system call argument
206374ca317cSVivek Goyal	  for kernel and initramfs as opposed to list of segments as
206474ca317cSVivek Goyal	  accepted by previous system call.
206574ca317cSVivek Goyal
2066b799a09fSAKASHI Takahiroconfig ARCH_HAS_KEXEC_PURGATORY
2067b799a09fSAKASHI Takahiro	def_bool KEXEC_FILE
2068b799a09fSAKASHI Takahiro
206999d5cadfSJiri Bohacconfig KEXEC_SIG
20708e7d8381SVivek Goyal	bool "Verify kernel signature during kexec_file_load() syscall"
207174ca317cSVivek Goyal	depends on KEXEC_FILE
20728e7d8381SVivek Goyal	---help---
207399d5cadfSJiri Bohac
207499d5cadfSJiri Bohac	  This option makes the kexec_file_load() syscall check for a valid
207599d5cadfSJiri Bohac	  signature of the kernel image.  The image can still be loaded without
207699d5cadfSJiri Bohac	  a valid signature unless you also enable KEXEC_SIG_FORCE, though if
207799d5cadfSJiri Bohac	  there's a signature that we can check, then it must be valid.
207899d5cadfSJiri Bohac
207999d5cadfSJiri Bohac	  In addition to this option, you need to enable signature
208099d5cadfSJiri Bohac	  verification for the corresponding kernel image type being
208199d5cadfSJiri Bohac	  loaded in order for this to work.
208299d5cadfSJiri Bohac
208399d5cadfSJiri Bohacconfig KEXEC_SIG_FORCE
208499d5cadfSJiri Bohac	bool "Require a valid signature in kexec_file_load() syscall"
208599d5cadfSJiri Bohac	depends on KEXEC_SIG
208699d5cadfSJiri Bohac	---help---
20878e7d8381SVivek Goyal	  This option makes kernel signature verification mandatory for
2088d8eb8940SBorislav Petkov	  the kexec_file_load() syscall.
20898e7d8381SVivek Goyal
20908e7d8381SVivek Goyalconfig KEXEC_BZIMAGE_VERIFY_SIG
20918e7d8381SVivek Goyal	bool "Enable bzImage signature verification support"
209299d5cadfSJiri Bohac	depends on KEXEC_SIG
20938e7d8381SVivek Goyal	depends on SIGNED_PE_FILE_VERIFICATION
20948e7d8381SVivek Goyal	select SYSTEM_TRUSTED_KEYRING
20958e7d8381SVivek Goyal	---help---
20968e7d8381SVivek Goyal	  Enable bzImage signature verification support.
20978e7d8381SVivek Goyal
2098506f1d07SSam Ravnborgconfig CRASH_DUMP
209904b69447SPavel Machek	bool "kernel crash dumps"
2100506f1d07SSam Ravnborg	depends on X86_64 || (X86_32 && HIGHMEM)
21018f9ca475SIngo Molnar	---help---
2102506f1d07SSam Ravnborg	  Generate crash dump after being started by kexec.
2103506f1d07SSam Ravnborg	  This should be normally only set in special crash dump kernels
2104506f1d07SSam Ravnborg	  which are loaded in the main kernel with kexec-tools into
2105506f1d07SSam Ravnborg	  a specially reserved region and then later executed after
2106506f1d07SSam Ravnborg	  a crash by kdump/kexec. The crash dump kernel must be compiled
2107506f1d07SSam Ravnborg	  to a memory address not used by the main kernel or BIOS using
2108506f1d07SSam Ravnborg	  PHYSICAL_START, or it must be built as a relocatable image
2109506f1d07SSam Ravnborg	  (CONFIG_RELOCATABLE=y).
2110330d4810SMauro Carvalho Chehab	  For more details see Documentation/admin-guide/kdump/kdump.rst
2111506f1d07SSam Ravnborg
21123ab83521SHuang Yingconfig KEXEC_JUMP
21136ea30386SKees Cook	bool "kexec jump"
2114fee7b0d8SHuang Ying	depends on KEXEC && HIBERNATION
21158f9ca475SIngo Molnar	---help---
211689081d17SHuang Ying	  Jump between original kernel and kexeced kernel and invoke
211789081d17SHuang Ying	  code in physical address mode via KEXEC
21183ab83521SHuang Ying
2119506f1d07SSam Ravnborgconfig PHYSICAL_START
21206a108a14SDavid Rientjes	hex "Physical address where the kernel is loaded" if (EXPERT || CRASH_DUMP)
2121ceefccc9SH. Peter Anvin	default "0x1000000"
21228f9ca475SIngo Molnar	---help---
2123506f1d07SSam Ravnborg	  This gives the physical address where the kernel is loaded.
2124506f1d07SSam Ravnborg
2125506f1d07SSam Ravnborg	  If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then
2126506f1d07SSam Ravnborg	  bzImage will decompress itself to above physical address and
2127506f1d07SSam Ravnborg	  run from there. Otherwise, bzImage will run from the address where
2128506f1d07SSam Ravnborg	  it has been loaded by the boot loader and will ignore above physical
2129506f1d07SSam Ravnborg	  address.
2130506f1d07SSam Ravnborg
2131506f1d07SSam Ravnborg	  In normal kdump cases one does not have to set/change this option
2132506f1d07SSam Ravnborg	  as now bzImage can be compiled as a completely relocatable image
2133506f1d07SSam Ravnborg	  (CONFIG_RELOCATABLE=y) and be used to load and run from a different
2134506f1d07SSam Ravnborg	  address. This option is mainly useful for the folks who don't want
2135506f1d07SSam Ravnborg	  to use a bzImage for capturing the crash dump and want to use a
2136506f1d07SSam Ravnborg	  vmlinux instead. vmlinux is not relocatable hence a kernel needs
2137506f1d07SSam Ravnborg	  to be specifically compiled to run from a specific memory area
2138506f1d07SSam Ravnborg	  (normally a reserved region) and this option comes handy.
2139506f1d07SSam Ravnborg
2140ceefccc9SH. Peter Anvin	  So if you are using bzImage for capturing the crash dump,
2141ceefccc9SH. Peter Anvin	  leave the value here unchanged to 0x1000000 and set
2142ceefccc9SH. Peter Anvin	  CONFIG_RELOCATABLE=y.  Otherwise if you plan to use vmlinux
2143ceefccc9SH. Peter Anvin	  for capturing the crash dump change this value to start of
2144ceefccc9SH. Peter Anvin	  the reserved region.  In other words, it can be set based on
2145ceefccc9SH. Peter Anvin	  the "X" value as specified in the "crashkernel=YM@XM"
2146ceefccc9SH. Peter Anvin	  command line boot parameter passed to the panic-ed
2147330d4810SMauro Carvalho Chehab	  kernel. Please take a look at Documentation/admin-guide/kdump/kdump.rst
2148ceefccc9SH. Peter Anvin	  for more details about crash dumps.
2149506f1d07SSam Ravnborg
2150506f1d07SSam Ravnborg	  Usage of bzImage for capturing the crash dump is recommended as
2151506f1d07SSam Ravnborg	  one does not have to build two kernels. Same kernel can be used
2152506f1d07SSam Ravnborg	  as production kernel and capture kernel. Above option should have
2153506f1d07SSam Ravnborg	  gone away after relocatable bzImage support is introduced. But it
2154506f1d07SSam Ravnborg	  is present because there are users out there who continue to use
2155506f1d07SSam Ravnborg	  vmlinux for dump capture. This option should go away down the
2156506f1d07SSam Ravnborg	  line.
2157506f1d07SSam Ravnborg
2158506f1d07SSam Ravnborg	  Don't change this unless you know what you are doing.
2159506f1d07SSam Ravnborg
2160506f1d07SSam Ravnborgconfig RELOCATABLE
216126717808SH. Peter Anvin	bool "Build a relocatable kernel"
216226717808SH. Peter Anvin	default y
21638f9ca475SIngo Molnar	---help---
2164506f1d07SSam Ravnborg	  This builds a kernel image that retains relocation information
2165506f1d07SSam Ravnborg	  so it can be loaded someplace besides the default 1MB.
2166506f1d07SSam Ravnborg	  The relocations tend to make the kernel binary about 10% larger,
2167506f1d07SSam Ravnborg	  but are discarded at runtime.
2168506f1d07SSam Ravnborg
2169506f1d07SSam Ravnborg	  One use is for the kexec on panic case where the recovery kernel
2170506f1d07SSam Ravnborg	  must live at a different physical address than the primary
2171506f1d07SSam Ravnborg	  kernel.
2172506f1d07SSam Ravnborg
2173506f1d07SSam Ravnborg	  Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address
2174506f1d07SSam Ravnborg	  it has been loaded at and the compile time physical address
21758ab3820fSKees Cook	  (CONFIG_PHYSICAL_START) is used as the minimum location.
2176506f1d07SSam Ravnborg
21778ab3820fSKees Cookconfig RANDOMIZE_BASE
2178e8581e3dSBaoquan He	bool "Randomize the address of the kernel image (KASLR)"
21798ab3820fSKees Cook	depends on RELOCATABLE
21806807c846SIngo Molnar	default y
21818ab3820fSKees Cook	---help---
2182e8581e3dSBaoquan He	  In support of Kernel Address Space Layout Randomization (KASLR),
2183e8581e3dSBaoquan He	  this randomizes the physical address at which the kernel image
2184e8581e3dSBaoquan He	  is decompressed and the virtual address where the kernel
2185e8581e3dSBaoquan He	  image is mapped, as a security feature that deters exploit
2186e8581e3dSBaoquan He	  attempts relying on knowledge of the location of kernel
2187e8581e3dSBaoquan He	  code internals.
2188e8581e3dSBaoquan He
2189ed9f007eSKees Cook	  On 64-bit, the kernel physical and virtual addresses are
2190ed9f007eSKees Cook	  randomized separately. The physical address will be anywhere
2191ed9f007eSKees Cook	  between 16MB and the top of physical memory (up to 64TB). The
2192ed9f007eSKees Cook	  virtual address will be randomized from 16MB up to 1GB (9 bits
2193ed9f007eSKees Cook	  of entropy). Note that this also reduces the memory space
2194ed9f007eSKees Cook	  available to kernel modules from 1.5GB to 1GB.
2195ed9f007eSKees Cook
2196ed9f007eSKees Cook	  On 32-bit, the kernel physical and virtual addresses are
2197ed9f007eSKees Cook	  randomized together. They will be randomized from 16MB up to
2198ed9f007eSKees Cook	  512MB (8 bits of entropy).
21998ab3820fSKees Cook
2200a653f356SKees Cook	  Entropy is generated using the RDRAND instruction if it is
2201e8581e3dSBaoquan He	  supported. If RDTSC is supported, its value is mixed into
2202e8581e3dSBaoquan He	  the entropy pool as well. If neither RDRAND nor RDTSC are
2203ed9f007eSKees Cook	  supported, then entropy is read from the i8254 timer. The
2204ed9f007eSKees Cook	  usable entropy is limited by the kernel being built using
2205ed9f007eSKees Cook	  2GB addressing, and that PHYSICAL_ALIGN must be at a
2206ed9f007eSKees Cook	  minimum of 2MB. As a result, only 10 bits of entropy are
2207ed9f007eSKees Cook	  theoretically possible, but the implementations are further
2208ed9f007eSKees Cook	  limited due to memory layouts.
2209e8581e3dSBaoquan He
22106807c846SIngo Molnar	  If unsure, say Y.
2211da2b6fb9SKees Cook
22128ab3820fSKees Cook# Relocation on x86 needs some additional build support
2213845adf72SH. Peter Anvinconfig X86_NEED_RELOCS
2214845adf72SH. Peter Anvin	def_bool y
22158ab3820fSKees Cook	depends on RANDOMIZE_BASE || (X86_32 && RELOCATABLE)
2216845adf72SH. Peter Anvin
2217506f1d07SSam Ravnborgconfig PHYSICAL_ALIGN
2218a0215061SKees Cook	hex "Alignment value to which kernel should be aligned"
22198ab3820fSKees Cook	default "0x200000"
2220a0215061SKees Cook	range 0x2000 0x1000000 if X86_32
2221a0215061SKees Cook	range 0x200000 0x1000000 if X86_64
22228f9ca475SIngo Molnar	---help---
2223506f1d07SSam Ravnborg	  This value puts the alignment restrictions on physical address
2224506f1d07SSam Ravnborg	  where kernel is loaded and run from. Kernel is compiled for an
2225506f1d07SSam Ravnborg	  address which meets above alignment restriction.
2226506f1d07SSam Ravnborg
2227506f1d07SSam Ravnborg	  If bootloader loads the kernel at a non-aligned address and
2228506f1d07SSam Ravnborg	  CONFIG_RELOCATABLE is set, kernel will move itself to nearest
2229506f1d07SSam Ravnborg	  address aligned to above value and run from there.
2230506f1d07SSam Ravnborg
2231506f1d07SSam Ravnborg	  If bootloader loads the kernel at a non-aligned address and
2232506f1d07SSam Ravnborg	  CONFIG_RELOCATABLE is not set, kernel will ignore the run time
2233506f1d07SSam Ravnborg	  load address and decompress itself to the address it has been
2234506f1d07SSam Ravnborg	  compiled for and run from there. The address for which kernel is
2235506f1d07SSam Ravnborg	  compiled already meets above alignment restrictions. Hence the
2236506f1d07SSam Ravnborg	  end result is that kernel runs from a physical address meeting
2237506f1d07SSam Ravnborg	  above alignment restrictions.
2238506f1d07SSam Ravnborg
2239a0215061SKees Cook	  On 32-bit this value must be a multiple of 0x2000. On 64-bit
2240a0215061SKees Cook	  this value must be a multiple of 0x200000.
2241a0215061SKees Cook
2242506f1d07SSam Ravnborg	  Don't change this unless you know what you are doing.
2243506f1d07SSam Ravnborg
2244eedb92abSKirill A. Shutemovconfig DYNAMIC_MEMORY_LAYOUT
2245eedb92abSKirill A. Shutemov	bool
2246eedb92abSKirill A. Shutemov	---help---
2247eedb92abSKirill A. Shutemov	  This option makes base addresses of vmalloc and vmemmap as well as
2248eedb92abSKirill A. Shutemov	  __PAGE_OFFSET movable during boot.
2249eedb92abSKirill A. Shutemov
22500483e1faSThomas Garnierconfig RANDOMIZE_MEMORY
22510483e1faSThomas Garnier	bool "Randomize the kernel memory sections"
22520483e1faSThomas Garnier	depends on X86_64
22530483e1faSThomas Garnier	depends on RANDOMIZE_BASE
2254eedb92abSKirill A. Shutemov	select DYNAMIC_MEMORY_LAYOUT
22550483e1faSThomas Garnier	default RANDOMIZE_BASE
22560483e1faSThomas Garnier	---help---
22570483e1faSThomas Garnier	   Randomizes the base virtual address of kernel memory sections
22580483e1faSThomas Garnier	   (physical memory mapping, vmalloc & vmemmap). This security feature
22590483e1faSThomas Garnier	   makes exploits relying on predictable memory locations less reliable.
22600483e1faSThomas Garnier
22610483e1faSThomas Garnier	   The order of allocations remains unchanged. Entropy is generated in
22620483e1faSThomas Garnier	   the same way as RANDOMIZE_BASE. Current implementation in the optimal
22630483e1faSThomas Garnier	   configuration have in average 30,000 different possible virtual
22640483e1faSThomas Garnier	   addresses for each memory section.
22650483e1faSThomas Garnier
22666807c846SIngo Molnar	   If unsure, say Y.
22670483e1faSThomas Garnier
226890397a41SThomas Garnierconfig RANDOMIZE_MEMORY_PHYSICAL_PADDING
226990397a41SThomas Garnier	hex "Physical memory mapping padding" if EXPERT
227090397a41SThomas Garnier	depends on RANDOMIZE_MEMORY
227190397a41SThomas Garnier	default "0xa" if MEMORY_HOTPLUG
227290397a41SThomas Garnier	default "0x0"
227390397a41SThomas Garnier	range 0x1 0x40 if MEMORY_HOTPLUG
227490397a41SThomas Garnier	range 0x0 0x40
227590397a41SThomas Garnier	---help---
227690397a41SThomas Garnier	   Define the padding in terabytes added to the existing physical
227790397a41SThomas Garnier	   memory size during kernel memory randomization. It is useful
227890397a41SThomas Garnier	   for memory hotplug support but reduces the entropy available for
227990397a41SThomas Garnier	   address randomization.
228090397a41SThomas Garnier
228190397a41SThomas Garnier	   If unsure, leave at the default value.
228290397a41SThomas Garnier
2283506f1d07SSam Ravnborgconfig HOTPLUG_CPU
2284bebd024eSThomas Gleixner	def_bool y
228540b31360SStephen Rothwell	depends on SMP
2286506f1d07SSam Ravnborg
228780aa1dffSFenghua Yuconfig BOOTPARAM_HOTPLUG_CPU0
228880aa1dffSFenghua Yu	bool "Set default setting of cpu0_hotpluggable"
22892c922cd0SKees Cook	depends on HOTPLUG_CPU
229080aa1dffSFenghua Yu	---help---
229180aa1dffSFenghua Yu	  Set whether default state of cpu0_hotpluggable is on or off.
229280aa1dffSFenghua Yu
229380aa1dffSFenghua Yu	  Say Y here to enable CPU0 hotplug by default. If this switch
229480aa1dffSFenghua Yu	  is turned on, there is no need to give cpu0_hotplug kernel
229580aa1dffSFenghua Yu	  parameter and the CPU0 hotplug feature is enabled by default.
229680aa1dffSFenghua Yu
229780aa1dffSFenghua Yu	  Please note: there are two known CPU0 dependencies if you want
229880aa1dffSFenghua Yu	  to enable the CPU0 hotplug feature either by this switch or by
229980aa1dffSFenghua Yu	  cpu0_hotplug kernel parameter.
230080aa1dffSFenghua Yu
230180aa1dffSFenghua Yu	  First, resume from hibernate or suspend always starts from CPU0.
230280aa1dffSFenghua Yu	  So hibernate and suspend are prevented if CPU0 is offline.
230380aa1dffSFenghua Yu
230480aa1dffSFenghua Yu	  Second dependency is PIC interrupts always go to CPU0. CPU0 can not
230580aa1dffSFenghua Yu	  offline if any interrupt can not migrate out of CPU0. There may
230680aa1dffSFenghua Yu	  be other CPU0 dependencies.
230780aa1dffSFenghua Yu
230880aa1dffSFenghua Yu	  Please make sure the dependencies are under your control before
230980aa1dffSFenghua Yu	  you enable this feature.
231080aa1dffSFenghua Yu
231180aa1dffSFenghua Yu	  Say N if you don't want to enable CPU0 hotplug feature by default.
231280aa1dffSFenghua Yu	  You still can enable the CPU0 hotplug feature at boot by kernel
231380aa1dffSFenghua Yu	  parameter cpu0_hotplug.
231480aa1dffSFenghua Yu
2315a71c8bc5SFenghua Yuconfig DEBUG_HOTPLUG_CPU0
2316a71c8bc5SFenghua Yu	def_bool n
2317a71c8bc5SFenghua Yu	prompt "Debug CPU0 hotplug"
23182c922cd0SKees Cook	depends on HOTPLUG_CPU
2319a71c8bc5SFenghua Yu	---help---
2320a71c8bc5SFenghua Yu	  Enabling this option offlines CPU0 (if CPU0 can be offlined) as
2321a71c8bc5SFenghua Yu	  soon as possible and boots up userspace with CPU0 offlined. User
2322a71c8bc5SFenghua Yu	  can online CPU0 back after boot time.
2323a71c8bc5SFenghua Yu
2324a71c8bc5SFenghua Yu	  To debug CPU0 hotplug, you need to enable CPU0 offline/online
2325a71c8bc5SFenghua Yu	  feature by either turning on CONFIG_BOOTPARAM_HOTPLUG_CPU0 during
2326a71c8bc5SFenghua Yu	  compilation or giving cpu0_hotplug kernel parameter at boot.
2327a71c8bc5SFenghua Yu
2328a71c8bc5SFenghua Yu	  If unsure, say N.
2329a71c8bc5SFenghua Yu
2330506f1d07SSam Ravnborgconfig COMPAT_VDSO
2331b0b49f26SAndy Lutomirski	def_bool n
2332b0b49f26SAndy Lutomirski	prompt "Disable the 32-bit vDSO (needed for glibc 2.3.3)"
2333953fee1dSIngo Molnar	depends on COMPAT_32
23348f9ca475SIngo Molnar	---help---
2335b0b49f26SAndy Lutomirski	  Certain buggy versions of glibc will crash if they are
2336b0b49f26SAndy Lutomirski	  presented with a 32-bit vDSO that is not mapped at the address
2337b0b49f26SAndy Lutomirski	  indicated in its segment table.
2338e84446deSRandy Dunlap
2339b0b49f26SAndy Lutomirski	  The bug was introduced by f866314b89d56845f55e6f365e18b31ec978ec3a
2340b0b49f26SAndy Lutomirski	  and fixed by 3b3ddb4f7db98ec9e912ccdf54d35df4aa30e04a and
2341b0b49f26SAndy Lutomirski	  49ad572a70b8aeb91e57483a11dd1b77e31c4468.  Glibc 2.3.3 is
2342b0b49f26SAndy Lutomirski	  the only released version with the bug, but OpenSUSE 9
2343b0b49f26SAndy Lutomirski	  contains a buggy "glibc 2.3.2".
2344506f1d07SSam Ravnborg
2345b0b49f26SAndy Lutomirski	  The symptom of the bug is that everything crashes on startup, saying:
2346b0b49f26SAndy Lutomirski	  dl_main: Assertion `(void *) ph->p_vaddr == _rtld_local._dl_sysinfo_dso' failed!
2347b0b49f26SAndy Lutomirski
2348b0b49f26SAndy Lutomirski	  Saying Y here changes the default value of the vdso32 boot
2349b0b49f26SAndy Lutomirski	  option from 1 to 0, which turns off the 32-bit vDSO entirely.
2350b0b49f26SAndy Lutomirski	  This works around the glibc bug but hurts performance.
2351b0b49f26SAndy Lutomirski
2352b0b49f26SAndy Lutomirski	  If unsure, say N: if you are compiling your own kernel, you
2353b0b49f26SAndy Lutomirski	  are unlikely to be using a buggy version of glibc.
2354506f1d07SSam Ravnborg
23553dc33bd3SKees Cookchoice
23563dc33bd3SKees Cook	prompt "vsyscall table for legacy applications"
23573dc33bd3SKees Cook	depends on X86_64
2358625b7b7fSAndy Lutomirski	default LEGACY_VSYSCALL_XONLY
23593dc33bd3SKees Cook	help
23603dc33bd3SKees Cook	  Legacy user code that does not know how to find the vDSO expects
23613dc33bd3SKees Cook	  to be able to issue three syscalls by calling fixed addresses in
23623dc33bd3SKees Cook	  kernel space. Since this location is not randomized with ASLR,
23633dc33bd3SKees Cook	  it can be used to assist security vulnerability exploitation.
23643dc33bd3SKees Cook
23653dc33bd3SKees Cook	  This setting can be changed at boot time via the kernel command
2366bd49e16eSAndy Lutomirski	  line parameter vsyscall=[emulate|xonly|none].
23673dc33bd3SKees Cook
23683dc33bd3SKees Cook	  On a system with recent enough glibc (2.14 or newer) and no
23693dc33bd3SKees Cook	  static binaries, you can say None without a performance penalty
23703dc33bd3SKees Cook	  to improve security.
23713dc33bd3SKees Cook
2372bd49e16eSAndy Lutomirski	  If unsure, select "Emulate execution only".
23733dc33bd3SKees Cook
23743dc33bd3SKees Cook	config LEGACY_VSYSCALL_EMULATE
2375bd49e16eSAndy Lutomirski		bool "Full emulation"
23763dc33bd3SKees Cook		help
2377bd49e16eSAndy Lutomirski		  The kernel traps and emulates calls into the fixed vsyscall
2378bd49e16eSAndy Lutomirski		  address mapping. This makes the mapping non-executable, but
2379bd49e16eSAndy Lutomirski		  it still contains readable known contents, which could be
2380bd49e16eSAndy Lutomirski		  used in certain rare security vulnerability exploits. This
2381bd49e16eSAndy Lutomirski		  configuration is recommended when using legacy userspace
2382bd49e16eSAndy Lutomirski		  that still uses vsyscalls along with legacy binary
2383bd49e16eSAndy Lutomirski		  instrumentation tools that require code to be readable.
2384bd49e16eSAndy Lutomirski
2385bd49e16eSAndy Lutomirski		  An example of this type of legacy userspace is running
2386bd49e16eSAndy Lutomirski		  Pin on an old binary that still uses vsyscalls.
2387bd49e16eSAndy Lutomirski
2388bd49e16eSAndy Lutomirski	config LEGACY_VSYSCALL_XONLY
2389bd49e16eSAndy Lutomirski		bool "Emulate execution only"
2390bd49e16eSAndy Lutomirski		help
2391bd49e16eSAndy Lutomirski		  The kernel traps and emulates calls into the fixed vsyscall
2392bd49e16eSAndy Lutomirski		  address mapping and does not allow reads.  This
2393bd49e16eSAndy Lutomirski		  configuration is recommended when userspace might use the
2394bd49e16eSAndy Lutomirski		  legacy vsyscall area but support for legacy binary
2395bd49e16eSAndy Lutomirski		  instrumentation of legacy code is not needed.  It mitigates
2396bd49e16eSAndy Lutomirski		  certain uses of the vsyscall area as an ASLR-bypassing
2397bd49e16eSAndy Lutomirski		  buffer.
23983dc33bd3SKees Cook
23993dc33bd3SKees Cook	config LEGACY_VSYSCALL_NONE
24003dc33bd3SKees Cook		bool "None"
24013dc33bd3SKees Cook		help
24023dc33bd3SKees Cook		  There will be no vsyscall mapping at all. This will
24033dc33bd3SKees Cook		  eliminate any risk of ASLR bypass due to the vsyscall
24043dc33bd3SKees Cook		  fixed address mapping. Attempts to use the vsyscalls
24053dc33bd3SKees Cook		  will be reported to dmesg, so that either old or
24063dc33bd3SKees Cook		  malicious userspace programs can be identified.
24073dc33bd3SKees Cook
24083dc33bd3SKees Cookendchoice
24093dc33bd3SKees Cook
2410516cbf37STim Birdconfig CMDLINE_BOOL
2411516cbf37STim Bird	bool "Built-in kernel command line"
24128f9ca475SIngo Molnar	---help---
2413516cbf37STim Bird	  Allow for specifying boot arguments to the kernel at
2414516cbf37STim Bird	  build time.  On some systems (e.g. embedded ones), it is
2415516cbf37STim Bird	  necessary or convenient to provide some or all of the
2416516cbf37STim Bird	  kernel boot arguments with the kernel itself (that is,
2417516cbf37STim Bird	  to not rely on the boot loader to provide them.)
2418516cbf37STim Bird
2419516cbf37STim Bird	  To compile command line arguments into the kernel,
2420516cbf37STim Bird	  set this option to 'Y', then fill in the
242169711ca1SSébastien Hinderer	  boot arguments in CONFIG_CMDLINE.
2422516cbf37STim Bird
2423516cbf37STim Bird	  Systems with fully functional boot loaders (i.e. non-embedded)
2424516cbf37STim Bird	  should leave this option set to 'N'.
2425516cbf37STim Bird
2426516cbf37STim Birdconfig CMDLINE
2427516cbf37STim Bird	string "Built-in kernel command string"
2428516cbf37STim Bird	depends on CMDLINE_BOOL
2429516cbf37STim Bird	default ""
24308f9ca475SIngo Molnar	---help---
2431516cbf37STim Bird	  Enter arguments here that should be compiled into the kernel
2432516cbf37STim Bird	  image and used at boot time.  If the boot loader provides a
2433516cbf37STim Bird	  command line at boot time, it is appended to this string to
2434516cbf37STim Bird	  form the full kernel command line, when the system boots.
2435516cbf37STim Bird
2436516cbf37STim Bird	  However, you can use the CONFIG_CMDLINE_OVERRIDE option to
2437516cbf37STim Bird	  change this behavior.
2438516cbf37STim Bird
2439516cbf37STim Bird	  In most cases, the command line (whether built-in or provided
2440516cbf37STim Bird	  by the boot loader) should specify the device for the root
2441516cbf37STim Bird	  file system.
2442516cbf37STim Bird
2443516cbf37STim Birdconfig CMDLINE_OVERRIDE
2444516cbf37STim Bird	bool "Built-in command line overrides boot loader arguments"
2445516cbf37STim Bird	depends on CMDLINE_BOOL
24468f9ca475SIngo Molnar	---help---
2447516cbf37STim Bird	  Set this option to 'Y' to have the kernel ignore the boot loader
2448516cbf37STim Bird	  command line, and use ONLY the built-in command line.
2449516cbf37STim Bird
2450516cbf37STim Bird	  This is used to work around broken boot loaders.  This should
2451516cbf37STim Bird	  be set to 'N' under normal conditions.
2452516cbf37STim Bird
2453a5b9e5a2SAndy Lutomirskiconfig MODIFY_LDT_SYSCALL
2454a5b9e5a2SAndy Lutomirski	bool "Enable the LDT (local descriptor table)" if EXPERT
2455a5b9e5a2SAndy Lutomirski	default y
2456a5b9e5a2SAndy Lutomirski	---help---
2457a5b9e5a2SAndy Lutomirski	  Linux can allow user programs to install a per-process x86
2458a5b9e5a2SAndy Lutomirski	  Local Descriptor Table (LDT) using the modify_ldt(2) system
2459a5b9e5a2SAndy Lutomirski	  call.  This is required to run 16-bit or segmented code such as
2460a5b9e5a2SAndy Lutomirski	  DOSEMU or some Wine programs.  It is also used by some very old
2461a5b9e5a2SAndy Lutomirski	  threading libraries.
2462a5b9e5a2SAndy Lutomirski
2463a5b9e5a2SAndy Lutomirski	  Enabling this feature adds a small amount of overhead to
2464a5b9e5a2SAndy Lutomirski	  context switches and increases the low-level kernel attack
2465a5b9e5a2SAndy Lutomirski	  surface.  Disabling it removes the modify_ldt(2) system call.
2466a5b9e5a2SAndy Lutomirski
2467a5b9e5a2SAndy Lutomirski	  Saying 'N' here may make sense for embedded or server kernels.
2468a5b9e5a2SAndy Lutomirski
2469b700e7f0SSeth Jenningssource "kernel/livepatch/Kconfig"
2470b700e7f0SSeth Jennings
2471506f1d07SSam Ravnborgendmenu
2472506f1d07SSam Ravnborg
24733072e413SMichal Hockoconfig ARCH_HAS_ADD_PAGES
24743072e413SMichal Hocko	def_bool y
24753072e413SMichal Hocko	depends on X86_64 && ARCH_ENABLE_MEMORY_HOTPLUG
24763072e413SMichal Hocko
2477506f1d07SSam Ravnborgconfig ARCH_ENABLE_MEMORY_HOTPLUG
2478506f1d07SSam Ravnborg	def_bool y
2479506f1d07SSam Ravnborg	depends on X86_64 || (X86_32 && HIGHMEM)
2480506f1d07SSam Ravnborg
248135551053SGary Hadeconfig ARCH_ENABLE_MEMORY_HOTREMOVE
248235551053SGary Hade	def_bool y
248335551053SGary Hade	depends on MEMORY_HOTPLUG
248435551053SGary Hade
2485e534c7c5SLee Schermerhornconfig USE_PERCPU_NUMA_NODE_ID
2486645a7919STejun Heo	def_bool y
2487e534c7c5SLee Schermerhorn	depends on NUMA
2488e534c7c5SLee Schermerhorn
24899491846fSKirill A. Shutemovconfig ARCH_ENABLE_SPLIT_PMD_PTLOCK
24909491846fSKirill A. Shutemov	def_bool y
24919491846fSKirill A. Shutemov	depends on X86_64 || X86_PAE
24929491846fSKirill A. Shutemov
2493c177c81eSNaoya Horiguchiconfig ARCH_ENABLE_HUGEPAGE_MIGRATION
2494c177c81eSNaoya Horiguchi	def_bool y
2495c177c81eSNaoya Horiguchi	depends on X86_64 && HUGETLB_PAGE && MIGRATION
2496c177c81eSNaoya Horiguchi
24979c670ea3SNaoya Horiguchiconfig ARCH_ENABLE_THP_MIGRATION
24989c670ea3SNaoya Horiguchi	def_bool y
24999c670ea3SNaoya Horiguchi	depends on X86_64 && TRANSPARENT_HUGEPAGE
25009c670ea3SNaoya Horiguchi
2501da85f865SBjorn Helgaasmenu "Power management and ACPI options"
2502e279b6c1SSam Ravnborg
2503e279b6c1SSam Ravnborgconfig ARCH_HIBERNATION_HEADER
25043c2362e6SHarvey Harrison	def_bool y
250544556530SZhimin Gu	depends on HIBERNATION
2506e279b6c1SSam Ravnborg
2507e279b6c1SSam Ravnborgsource "kernel/power/Kconfig"
2508e279b6c1SSam Ravnborg
2509e279b6c1SSam Ravnborgsource "drivers/acpi/Kconfig"
2510e279b6c1SSam Ravnborg
2511efafc8b2SFeng Tangsource "drivers/sfi/Kconfig"
2512efafc8b2SFeng Tang
2513a6b68076SAndi Kleenconfig X86_APM_BOOT
25146fc108a0SJan Beulich	def_bool y
2515282e5aabSPaul Bolle	depends on APM
2516a6b68076SAndi Kleen
2517e279b6c1SSam Ravnborgmenuconfig APM
2518e279b6c1SSam Ravnborg	tristate "APM (Advanced Power Management) BIOS support"
2519efefa6f6SIngo Molnar	depends on X86_32 && PM_SLEEP
2520e279b6c1SSam Ravnborg	---help---
2521e279b6c1SSam Ravnborg	  APM is a BIOS specification for saving power using several different
2522e279b6c1SSam Ravnborg	  techniques. This is mostly useful for battery powered laptops with
2523e279b6c1SSam Ravnborg	  APM compliant BIOSes. If you say Y here, the system time will be
2524e279b6c1SSam Ravnborg	  reset after a RESUME operation, the /proc/apm device will provide
2525e279b6c1SSam Ravnborg	  battery status information, and user-space programs will receive
2526e279b6c1SSam Ravnborg	  notification of APM "events" (e.g. battery status change).
2527e279b6c1SSam Ravnborg
2528e279b6c1SSam Ravnborg	  If you select "Y" here, you can disable actual use of the APM
2529e279b6c1SSam Ravnborg	  BIOS by passing the "apm=off" option to the kernel at boot time.
2530e279b6c1SSam Ravnborg
2531e279b6c1SSam Ravnborg	  Note that the APM support is almost completely disabled for
2532e279b6c1SSam Ravnborg	  machines with more than one CPU.
2533e279b6c1SSam Ravnborg
2534e279b6c1SSam Ravnborg	  In order to use APM, you will need supporting software. For location
2535151f4e2bSMauro Carvalho Chehab	  and more information, read <file:Documentation/power/apm-acpi.rst>
25362dc98fd3SMichael Witten	  and the Battery Powered Linux mini-HOWTO, available from
2537e279b6c1SSam Ravnborg	  <http://www.tldp.org/docs.html#howto>.
2538e279b6c1SSam Ravnborg
2539e279b6c1SSam Ravnborg	  This driver does not spin down disk drives (see the hdparm(8)
2540e279b6c1SSam Ravnborg	  manpage ("man 8 hdparm") for that), and it doesn't turn off
2541e279b6c1SSam Ravnborg	  VESA-compliant "green" monitors.
2542e279b6c1SSam Ravnborg
2543e279b6c1SSam Ravnborg	  This driver does not support the TI 4000M TravelMate and the ACER
2544e279b6c1SSam Ravnborg	  486/DX4/75 because they don't have compliant BIOSes. Many "green"
2545e279b6c1SSam Ravnborg	  desktop machines also don't have compliant BIOSes, and this driver
2546e279b6c1SSam Ravnborg	  may cause those machines to panic during the boot phase.
2547e279b6c1SSam Ravnborg
2548e279b6c1SSam Ravnborg	  Generally, if you don't have a battery in your machine, there isn't
2549e279b6c1SSam Ravnborg	  much point in using this driver and you should say N. If you get
2550e279b6c1SSam Ravnborg	  random kernel OOPSes or reboots that don't seem to be related to
2551e279b6c1SSam Ravnborg	  anything, try disabling/enabling this option (or disabling/enabling
2552e279b6c1SSam Ravnborg	  APM in your BIOS).
2553e279b6c1SSam Ravnborg
2554e279b6c1SSam Ravnborg	  Some other things you should try when experiencing seemingly random,
2555e279b6c1SSam Ravnborg	  "weird" problems:
2556e279b6c1SSam Ravnborg
2557e279b6c1SSam Ravnborg	  1) make sure that you have enough swap space and that it is
2558e279b6c1SSam Ravnborg	  enabled.
2559e279b6c1SSam Ravnborg	  2) pass the "no-hlt" option to the kernel
2560e279b6c1SSam Ravnborg	  3) switch on floating point emulation in the kernel and pass
2561e279b6c1SSam Ravnborg	  the "no387" option to the kernel
2562e279b6c1SSam Ravnborg	  4) pass the "floppy=nodma" option to the kernel
2563e279b6c1SSam Ravnborg	  5) pass the "mem=4M" option to the kernel (thereby disabling
2564e279b6c1SSam Ravnborg	  all but the first 4 MB of RAM)
2565e279b6c1SSam Ravnborg	  6) make sure that the CPU is not over clocked.
2566e279b6c1SSam Ravnborg	  7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/>
2567e279b6c1SSam Ravnborg	  8) disable the cache from your BIOS settings
2568e279b6c1SSam Ravnborg	  9) install a fan for the video card or exchange video RAM
2569e279b6c1SSam Ravnborg	  10) install a better fan for the CPU
2570e279b6c1SSam Ravnborg	  11) exchange RAM chips
2571e279b6c1SSam Ravnborg	  12) exchange the motherboard.
2572e279b6c1SSam Ravnborg
2573e279b6c1SSam Ravnborg	  To compile this driver as a module, choose M here: the
2574e279b6c1SSam Ravnborg	  module will be called apm.
2575e279b6c1SSam Ravnborg
2576e279b6c1SSam Ravnborgif APM
2577e279b6c1SSam Ravnborg
2578e279b6c1SSam Ravnborgconfig APM_IGNORE_USER_SUSPEND
2579e279b6c1SSam Ravnborg	bool "Ignore USER SUSPEND"
25808f9ca475SIngo Molnar	---help---
2581e279b6c1SSam Ravnborg	  This option will ignore USER SUSPEND requests. On machines with a
2582e279b6c1SSam Ravnborg	  compliant APM BIOS, you want to say N. However, on the NEC Versa M
2583e279b6c1SSam Ravnborg	  series notebooks, it is necessary to say Y because of a BIOS bug.
2584e279b6c1SSam Ravnborg
2585e279b6c1SSam Ravnborgconfig APM_DO_ENABLE
2586e279b6c1SSam Ravnborg	bool "Enable PM at boot time"
2587e279b6c1SSam Ravnborg	---help---
2588e279b6c1SSam Ravnborg	  Enable APM features at boot time. From page 36 of the APM BIOS
2589e279b6c1SSam Ravnborg	  specification: "When disabled, the APM BIOS does not automatically
2590e279b6c1SSam Ravnborg	  power manage devices, enter the Standby State, enter the Suspend
2591e279b6c1SSam Ravnborg	  State, or take power saving steps in response to CPU Idle calls."
2592e279b6c1SSam Ravnborg	  This driver will make CPU Idle calls when Linux is idle (unless this
2593e279b6c1SSam Ravnborg	  feature is turned off -- see "Do CPU IDLE calls", below). This
2594e279b6c1SSam Ravnborg	  should always save battery power, but more complicated APM features
2595e279b6c1SSam Ravnborg	  will be dependent on your BIOS implementation. You may need to turn
2596e279b6c1SSam Ravnborg	  this option off if your computer hangs at boot time when using APM
2597e279b6c1SSam Ravnborg	  support, or if it beeps continuously instead of suspending. Turn
2598e279b6c1SSam Ravnborg	  this off if you have a NEC UltraLite Versa 33/C or a Toshiba
2599e279b6c1SSam Ravnborg	  T400CDT. This is off by default since most machines do fine without
2600e279b6c1SSam Ravnborg	  this feature.
2601e279b6c1SSam Ravnborg
2602e279b6c1SSam Ravnborgconfig APM_CPU_IDLE
2603dd8af076SLen Brown	depends on CPU_IDLE
2604e279b6c1SSam Ravnborg	bool "Make CPU Idle calls when idle"
26058f9ca475SIngo Molnar	---help---
2606e279b6c1SSam Ravnborg	  Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop.
2607e279b6c1SSam Ravnborg	  On some machines, this can activate improved power savings, such as
2608e279b6c1SSam Ravnborg	  a slowed CPU clock rate, when the machine is idle. These idle calls
2609e279b6c1SSam Ravnborg	  are made after the idle loop has run for some length of time (e.g.,
2610e279b6c1SSam Ravnborg	  333 mS). On some machines, this will cause a hang at boot time or
2611e279b6c1SSam Ravnborg	  whenever the CPU becomes idle. (On machines with more than one CPU,
2612e279b6c1SSam Ravnborg	  this option does nothing.)
2613e279b6c1SSam Ravnborg
2614e279b6c1SSam Ravnborgconfig APM_DISPLAY_BLANK
2615e279b6c1SSam Ravnborg	bool "Enable console blanking using APM"
26168f9ca475SIngo Molnar	---help---
2617e279b6c1SSam Ravnborg	  Enable console blanking using the APM. Some laptops can use this to
2618e279b6c1SSam Ravnborg	  turn off the LCD backlight when the screen blanker of the Linux
2619e279b6c1SSam Ravnborg	  virtual console blanks the screen. Note that this is only used by
2620e279b6c1SSam Ravnborg	  the virtual console screen blanker, and won't turn off the backlight
2621e279b6c1SSam Ravnborg	  when using the X Window system. This also doesn't have anything to
2622e279b6c1SSam Ravnborg	  do with your VESA-compliant power-saving monitor. Further, this
2623e279b6c1SSam Ravnborg	  option doesn't work for all laptops -- it might not turn off your
2624e279b6c1SSam Ravnborg	  backlight at all, or it might print a lot of errors to the console,
2625e279b6c1SSam Ravnborg	  especially if you are using gpm.
2626e279b6c1SSam Ravnborg
2627e279b6c1SSam Ravnborgconfig APM_ALLOW_INTS
2628e279b6c1SSam Ravnborg	bool "Allow interrupts during APM BIOS calls"
26298f9ca475SIngo Molnar	---help---
2630e279b6c1SSam Ravnborg	  Normally we disable external interrupts while we are making calls to
2631e279b6c1SSam Ravnborg	  the APM BIOS as a measure to lessen the effects of a badly behaving
2632e279b6c1SSam Ravnborg	  BIOS implementation.  The BIOS should reenable interrupts if it
2633e279b6c1SSam Ravnborg	  needs to.  Unfortunately, some BIOSes do not -- especially those in
2634e279b6c1SSam Ravnborg	  many of the newer IBM Thinkpads.  If you experience hangs when you
2635e279b6c1SSam Ravnborg	  suspend, try setting this to Y.  Otherwise, say N.
2636e279b6c1SSam Ravnborg
2637e279b6c1SSam Ravnborgendif # APM
2638e279b6c1SSam Ravnborg
2639bb0a56ecSDave Jonessource "drivers/cpufreq/Kconfig"
2640e279b6c1SSam Ravnborg
2641e279b6c1SSam Ravnborgsource "drivers/cpuidle/Kconfig"
2642e279b6c1SSam Ravnborg
264327471fdbSAndy Henroidsource "drivers/idle/Kconfig"
264427471fdbSAndy Henroid
2645e279b6c1SSam Ravnborgendmenu
2646e279b6c1SSam Ravnborg
2647e279b6c1SSam Ravnborg
2648e279b6c1SSam Ravnborgmenu "Bus options (PCI etc.)"
2649e279b6c1SSam Ravnborg
2650e279b6c1SSam Ravnborgchoice
2651e279b6c1SSam Ravnborg	prompt "PCI access mode"
2652efefa6f6SIngo Molnar	depends on X86_32 && PCI
2653e279b6c1SSam Ravnborg	default PCI_GOANY
2654e279b6c1SSam Ravnborg	---help---
2655e279b6c1SSam Ravnborg	  On PCI systems, the BIOS can be used to detect the PCI devices and
2656e279b6c1SSam Ravnborg	  determine their configuration. However, some old PCI motherboards
2657e279b6c1SSam Ravnborg	  have BIOS bugs and may crash if this is done. Also, some embedded
2658e279b6c1SSam Ravnborg	  PCI-based systems don't have any BIOS at all. Linux can also try to
2659e279b6c1SSam Ravnborg	  detect the PCI hardware directly without using the BIOS.
2660e279b6c1SSam Ravnborg
2661e279b6c1SSam Ravnborg	  With this option, you can specify how Linux should detect the
2662e279b6c1SSam Ravnborg	  PCI devices. If you choose "BIOS", the BIOS will be used,
2663e279b6c1SSam Ravnborg	  if you choose "Direct", the BIOS won't be used, and if you
2664e279b6c1SSam Ravnborg	  choose "MMConfig", then PCI Express MMCONFIG will be used.
2665e279b6c1SSam Ravnborg	  If you choose "Any", the kernel will try MMCONFIG, then the
2666e279b6c1SSam Ravnborg	  direct access method and falls back to the BIOS if that doesn't
2667e279b6c1SSam Ravnborg	  work. If unsure, go with the default, which is "Any".
2668e279b6c1SSam Ravnborg
2669e279b6c1SSam Ravnborgconfig PCI_GOBIOS
2670e279b6c1SSam Ravnborg	bool "BIOS"
2671e279b6c1SSam Ravnborg
2672e279b6c1SSam Ravnborgconfig PCI_GOMMCONFIG
2673e279b6c1SSam Ravnborg	bool "MMConfig"
2674e279b6c1SSam Ravnborg
2675e279b6c1SSam Ravnborgconfig PCI_GODIRECT
2676e279b6c1SSam Ravnborg	bool "Direct"
2677e279b6c1SSam Ravnborg
26783ef0e1f8SAndres Salomonconfig PCI_GOOLPC
267976fb6570SDaniel Drake	bool "OLPC XO-1"
26803ef0e1f8SAndres Salomon	depends on OLPC
26813ef0e1f8SAndres Salomon
26822bdd1b03SAndres Salomonconfig PCI_GOANY
26832bdd1b03SAndres Salomon	bool "Any"
26842bdd1b03SAndres Salomon
2685e279b6c1SSam Ravnborgendchoice
2686e279b6c1SSam Ravnborg
2687e279b6c1SSam Ravnborgconfig PCI_BIOS
26883c2362e6SHarvey Harrison	def_bool y
2689efefa6f6SIngo Molnar	depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY)
2690e279b6c1SSam Ravnborg
2691e279b6c1SSam Ravnborg# x86-64 doesn't support PCI BIOS access from long mode so always go direct.
2692e279b6c1SSam Ravnborgconfig PCI_DIRECT
26933c2362e6SHarvey Harrison	def_bool y
26940aba496fSShaohua Li	depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC || PCI_GOMMCONFIG))
2695e279b6c1SSam Ravnborg
2696e279b6c1SSam Ravnborgconfig PCI_MMCONFIG
2697b45c9f36SJan Kiszka	bool "Support mmconfig PCI config space access" if X86_64
2698b45c9f36SJan Kiszka	default y
26998364e1f8SJan Kiszka	depends on PCI && (ACPI || SFI || JAILHOUSE_GUEST)
2700b45c9f36SJan Kiszka	depends on X86_64 || (PCI_GOANY || PCI_GOMMCONFIG)
2701e279b6c1SSam Ravnborg
27023ef0e1f8SAndres Salomonconfig PCI_OLPC
27032bdd1b03SAndres Salomon	def_bool y
27042bdd1b03SAndres Salomon	depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY)
27053ef0e1f8SAndres Salomon
2706b5401a96SAlex Nixonconfig PCI_XEN
2707b5401a96SAlex Nixon	def_bool y
2708b5401a96SAlex Nixon	depends on PCI && XEN
2709b5401a96SAlex Nixon	select SWIOTLB_XEN
2710b5401a96SAlex Nixon
27118364e1f8SJan Kiszkaconfig MMCONF_FAM10H
27128364e1f8SJan Kiszka	def_bool y
27138364e1f8SJan Kiszka	depends on X86_64 && PCI_MMCONFIG && ACPI
2714e279b6c1SSam Ravnborg
27153f6ea84aSIra W. Snyderconfig PCI_CNB20LE_QUIRK
27166a108a14SDavid Rientjes	bool "Read CNB20LE Host Bridge Windows" if EXPERT
27176ea30386SKees Cook	depends on PCI
27183f6ea84aSIra W. Snyder	help
27193f6ea84aSIra W. Snyder	  Read the PCI windows out of the CNB20LE host bridge. This allows
27203f6ea84aSIra W. Snyder	  PCI hotplug to work on systems with the CNB20LE chipset which do
27213f6ea84aSIra W. Snyder	  not have ACPI.
27223f6ea84aSIra W. Snyder
272364a5fed6SBjorn Helgaas	  There's no public spec for this chipset, and this functionality
272464a5fed6SBjorn Helgaas	  is known to be incomplete.
272564a5fed6SBjorn Helgaas
272664a5fed6SBjorn Helgaas	  You should say N unless you know you need this.
272764a5fed6SBjorn Helgaas
27283a495511SWilliam Breathitt Grayconfig ISA_BUS
272917a2a129SWilliam Breathitt Gray	bool "ISA bus support on modern systems" if EXPERT
27303a495511SWilliam Breathitt Gray	help
273117a2a129SWilliam Breathitt Gray	  Expose ISA bus device drivers and options available for selection and
273217a2a129SWilliam Breathitt Gray	  configuration. Enable this option if your target machine has an ISA
273317a2a129SWilliam Breathitt Gray	  bus. ISA is an older system, displaced by PCI and newer bus
273417a2a129SWilliam Breathitt Gray	  architectures -- if your target machine is modern, it probably does
273517a2a129SWilliam Breathitt Gray	  not have an ISA bus.
27363a495511SWilliam Breathitt Gray
27373a495511SWilliam Breathitt Gray	  If unsure, say N.
27383a495511SWilliam Breathitt Gray
27391c00f016SDavid Rientjes# x86_64 have no ISA slots, but can have ISA-style DMA.
2740e279b6c1SSam Ravnborgconfig ISA_DMA_API
27411c00f016SDavid Rientjes	bool "ISA-style DMA support" if (X86_64 && EXPERT)
27421c00f016SDavid Rientjes	default y
27431c00f016SDavid Rientjes	help
27441c00f016SDavid Rientjes	  Enables ISA-style DMA support for devices requiring such controllers.
27451c00f016SDavid Rientjes	  If unsure, say Y.
2746e279b6c1SSam Ravnborg
274751e68d05SLinus Torvaldsif X86_32
274851e68d05SLinus Torvalds
2749e279b6c1SSam Ravnborgconfig ISA
2750e279b6c1SSam Ravnborg	bool "ISA support"
27518f9ca475SIngo Molnar	---help---
2752e279b6c1SSam Ravnborg	  Find out whether you have ISA slots on your motherboard.  ISA is the
2753e279b6c1SSam Ravnborg	  name of a bus system, i.e. the way the CPU talks to the other stuff
2754e279b6c1SSam Ravnborg	  inside your box.  Other bus systems are PCI, EISA, MicroChannel
2755e279b6c1SSam Ravnborg	  (MCA) or VESA.  ISA is an older system, now being displaced by PCI;
2756e279b6c1SSam Ravnborg	  newer boards don't support it.  If you have ISA, say Y, otherwise N.
2757e279b6c1SSam Ravnborg
2758e279b6c1SSam Ravnborgconfig SCx200
2759e279b6c1SSam Ravnborg	tristate "NatSemi SCx200 support"
27608f9ca475SIngo Molnar	---help---
2761e279b6c1SSam Ravnborg	  This provides basic support for National Semiconductor's
2762e279b6c1SSam Ravnborg	  (now AMD's) Geode processors.  The driver probes for the
2763e279b6c1SSam Ravnborg	  PCI-IDs of several on-chip devices, so its a good dependency
2764e279b6c1SSam Ravnborg	  for other scx200_* drivers.
2765e279b6c1SSam Ravnborg
2766e279b6c1SSam Ravnborg	  If compiled as a module, the driver is named scx200.
2767e279b6c1SSam Ravnborg
2768e279b6c1SSam Ravnborgconfig SCx200HR_TIMER
2769e279b6c1SSam Ravnborg	tristate "NatSemi SCx200 27MHz High-Resolution Timer Support"
2770592913ecSJohn Stultz	depends on SCx200
2771e279b6c1SSam Ravnborg	default y
27728f9ca475SIngo Molnar	---help---
2773e279b6c1SSam Ravnborg	  This driver provides a clocksource built upon the on-chip
2774e279b6c1SSam Ravnborg	  27MHz high-resolution timer.  Its also a workaround for
2775e279b6c1SSam Ravnborg	  NSC Geode SC-1100's buggy TSC, which loses time when the
2776e279b6c1SSam Ravnborg	  processor goes idle (as is done by the scheduler).  The
2777e279b6c1SSam Ravnborg	  other workaround is idle=poll boot option.
2778e279b6c1SSam Ravnborg
27793ef0e1f8SAndres Salomonconfig OLPC
27803ef0e1f8SAndres Salomon	bool "One Laptop Per Child support"
278154008979SThomas Gleixner	depends on !X86_PAE
27823c554946SAndres Salomon	select GPIOLIB
2783dc3119e7SThomas Gleixner	select OF
278445bb1674SDaniel Drake	select OF_PROMTREE
2785b4e51854SGrant Likely	select IRQ_DOMAIN
27860c3d931bSLubomir Rintel	select OLPC_EC
27878f9ca475SIngo Molnar	---help---
27883ef0e1f8SAndres Salomon	  Add support for detecting the unique features of the OLPC
27893ef0e1f8SAndres Salomon	  XO hardware.
27903ef0e1f8SAndres Salomon
2791a3128588SDaniel Drakeconfig OLPC_XO1_PM
2792a3128588SDaniel Drake	bool "OLPC XO-1 Power Management"
2793fa112cf1SBorislav Petkov	depends on OLPC && MFD_CS5535=y && PM_SLEEP
2794bf1ebf00SDaniel Drake	---help---
279597c4cb71SDaniel Drake	  Add support for poweroff and suspend of the OLPC XO-1 laptop.
2796bf1ebf00SDaniel Drake
2797cfee9597SDaniel Drakeconfig OLPC_XO1_RTC
2798cfee9597SDaniel Drake	bool "OLPC XO-1 Real Time Clock"
2799cfee9597SDaniel Drake	depends on OLPC_XO1_PM && RTC_DRV_CMOS
2800cfee9597SDaniel Drake	---help---
2801cfee9597SDaniel Drake	  Add support for the XO-1 real time clock, which can be used as a
2802cfee9597SDaniel Drake	  programmable wakeup source.
2803cfee9597SDaniel Drake
28047feda8e9SDaniel Drakeconfig OLPC_XO1_SCI
28057feda8e9SDaniel Drake	bool "OLPC XO-1 SCI extras"
280692e830f2SArnd Bergmann	depends on OLPC && OLPC_XO1_PM && GPIO_CS5535=y
2807ed8e47feSRandy Dunlap	depends on INPUT=y
2808d8d01a63SDaniel Drake	select POWER_SUPPLY
28097feda8e9SDaniel Drake	---help---
28107feda8e9SDaniel Drake	  Add support for SCI-based features of the OLPC XO-1 laptop:
28117bc74b3dSDaniel Drake	   - EC-driven system wakeups
28127feda8e9SDaniel Drake	   - Power button
28137bc74b3dSDaniel Drake	   - Ebook switch
28142cf2baeaSDaniel Drake	   - Lid switch
2815e1040ac6SDaniel Drake	   - AC adapter status updates
2816e1040ac6SDaniel Drake	   - Battery status updates
28177feda8e9SDaniel Drake
2818a0f30f59SDaniel Drakeconfig OLPC_XO15_SCI
2819a0f30f59SDaniel Drake	bool "OLPC XO-1.5 SCI extras"
2820d8d01a63SDaniel Drake	depends on OLPC && ACPI
2821d8d01a63SDaniel Drake	select POWER_SUPPLY
2822a0f30f59SDaniel Drake	---help---
2823a0f30f59SDaniel Drake	  Add support for SCI-based features of the OLPC XO-1.5 laptop:
2824a0f30f59SDaniel Drake	   - EC-driven system wakeups
2825a0f30f59SDaniel Drake	   - AC adapter status updates
2826a0f30f59SDaniel Drake	   - Battery status updates
2827e279b6c1SSam Ravnborg
2828d4f3e350SEd Wildgooseconfig ALIX
2829d4f3e350SEd Wildgoose	bool "PCEngines ALIX System Support (LED setup)"
2830d4f3e350SEd Wildgoose	select GPIOLIB
2831d4f3e350SEd Wildgoose	---help---
2832d4f3e350SEd Wildgoose	  This option enables system support for the PCEngines ALIX.
2833d4f3e350SEd Wildgoose	  At present this just sets up LEDs for GPIO control on
2834d4f3e350SEd Wildgoose	  ALIX2/3/6 boards.  However, other system specific setup should
2835d4f3e350SEd Wildgoose	  get added here.
2836d4f3e350SEd Wildgoose
2837d4f3e350SEd Wildgoose	  Note: You must still enable the drivers for GPIO and LED support
2838d4f3e350SEd Wildgoose	  (GPIO_CS5535 & LEDS_GPIO) to actually use the LEDs
2839d4f3e350SEd Wildgoose
2840d4f3e350SEd Wildgoose	  Note: You have to set alix.force=1 for boards with Award BIOS.
2841d4f3e350SEd Wildgoose
2842da4e3302SPhilip Prindevilleconfig NET5501
2843da4e3302SPhilip Prindeville	bool "Soekris Engineering net5501 System Support (LEDS, GPIO, etc)"
2844da4e3302SPhilip Prindeville	select GPIOLIB
2845da4e3302SPhilip Prindeville	---help---
2846da4e3302SPhilip Prindeville	  This option enables system support for the Soekris Engineering net5501.
2847da4e3302SPhilip Prindeville
28483197059aSPhilip A. Prindevilleconfig GEOS
28493197059aSPhilip A. Prindeville	bool "Traverse Technologies GEOS System Support (LEDS, GPIO, etc)"
28503197059aSPhilip A. Prindeville	select GPIOLIB
28513197059aSPhilip A. Prindeville	depends on DMI
28523197059aSPhilip A. Prindeville	---help---
28533197059aSPhilip A. Prindeville	  This option enables system support for the Traverse Technologies GEOS.
28543197059aSPhilip A. Prindeville
28557d029125SVivien Didelotconfig TS5500
28567d029125SVivien Didelot	bool "Technologic Systems TS-5500 platform support"
28577d029125SVivien Didelot	depends on MELAN
28587d029125SVivien Didelot	select CHECK_SIGNATURE
28597d029125SVivien Didelot	select NEW_LEDS
28607d029125SVivien Didelot	select LEDS_CLASS
28617d029125SVivien Didelot	---help---
28627d029125SVivien Didelot	  This option enables system support for the Technologic Systems TS-5500.
28637d029125SVivien Didelot
2864e279b6c1SSam Ravnborgendif # X86_32
2865e279b6c1SSam Ravnborg
286623ac4ae8SAndreas Herrmannconfig AMD_NB
2867e279b6c1SSam Ravnborg	def_bool y
28680e152cd7SBorislav Petkov	depends on CPU_SUP_AMD && PCI
2869e279b6c1SSam Ravnborg
2870e3263ab3SDavid Herrmannconfig X86_SYSFB
2871e3263ab3SDavid Herrmann	bool "Mark VGA/VBE/EFI FB as generic system framebuffer"
2872e3263ab3SDavid Herrmann	help
2873e3263ab3SDavid Herrmann	  Firmwares often provide initial graphics framebuffers so the BIOS,
2874e3263ab3SDavid Herrmann	  bootloader or kernel can show basic video-output during boot for
2875e3263ab3SDavid Herrmann	  user-guidance and debugging. Historically, x86 used the VESA BIOS
2876e3263ab3SDavid Herrmann	  Extensions and EFI-framebuffers for this, which are mostly limited
2877e3263ab3SDavid Herrmann	  to x86.
2878e3263ab3SDavid Herrmann	  This option, if enabled, marks VGA/VBE/EFI framebuffers as generic
2879e3263ab3SDavid Herrmann	  framebuffers so the new generic system-framebuffer drivers can be
2880e3263ab3SDavid Herrmann	  used on x86. If the framebuffer is not compatible with the generic
2881e3a5dc08SNikolas Nyby	  modes, it is advertised as fallback platform framebuffer so legacy
2882e3263ab3SDavid Herrmann	  drivers like efifb, vesafb and uvesafb can pick it up.
2883e3263ab3SDavid Herrmann	  If this option is not selected, all system framebuffers are always
2884e3263ab3SDavid Herrmann	  marked as fallback platform framebuffers as usual.
2885e3263ab3SDavid Herrmann
2886e3263ab3SDavid Herrmann	  Note: Legacy fbdev drivers, including vesafb, efifb, uvesafb, will
2887e3263ab3SDavid Herrmann	  not be able to pick up generic system framebuffers if this option
2888e3263ab3SDavid Herrmann	  is selected. You are highly encouraged to enable simplefb as
2889e3263ab3SDavid Herrmann	  replacement if you select this option. simplefb can correctly deal
2890e3263ab3SDavid Herrmann	  with generic system framebuffers. But you should still keep vesafb
2891e3263ab3SDavid Herrmann	  and others enabled as fallback if a system framebuffer is
2892e3263ab3SDavid Herrmann	  incompatible with simplefb.
2893e3263ab3SDavid Herrmann
2894e3263ab3SDavid Herrmann	  If unsure, say Y.
2895e3263ab3SDavid Herrmann
2896e279b6c1SSam Ravnborgendmenu
2897e279b6c1SSam Ravnborg
2898e279b6c1SSam Ravnborg
28991572497cSChristoph Hellwigmenu "Binary Emulations"
2900e279b6c1SSam Ravnborg
2901e279b6c1SSam Ravnborgconfig IA32_EMULATION
2902e279b6c1SSam Ravnborg	bool "IA32 Emulation"
2903e279b6c1SSam Ravnborg	depends on X86_64
290439f88911SIngo Molnar	select ARCH_WANT_OLD_COMPAT_IPC
2905d1603990SRandy Dunlap	select BINFMT_ELF
2906a97f52e6SRoland McGrath	select COMPAT_BINFMT_ELF
290739f88911SIngo Molnar	select COMPAT_OLD_SIGACTION
29088f9ca475SIngo Molnar	---help---
29095fd92e65SH. J. Lu	  Include code to run legacy 32-bit programs under a
29105fd92e65SH. J. Lu	  64-bit kernel. You should likely turn this on, unless you're
29115fd92e65SH. J. Lu	  100% sure that you don't have any 32-bit programs left.
2912e279b6c1SSam Ravnborg
2913e279b6c1SSam Ravnborgconfig IA32_AOUT
2914e279b6c1SSam Ravnborg	tristate "IA32 a.out support"
29156b213e1bSDavid Woodhouse	depends on IA32_EMULATION
2916eac61655SBorislav Petkov	depends on BROKEN
29178f9ca475SIngo Molnar	---help---
2918e279b6c1SSam Ravnborg	  Support old a.out binaries in the 32bit emulation.
2919e279b6c1SSam Ravnborg
29200bf62763SH. Peter Anvinconfig X86_X32
29216ea30386SKees Cook	bool "x32 ABI for 64-bit mode"
29229b54050bSBrian Gerst	depends on X86_64
29235fd92e65SH. J. Lu	---help---
29245fd92e65SH. J. Lu	  Include code to run binaries for the x32 native 32-bit ABI
29255fd92e65SH. J. Lu	  for 64-bit processors.  An x32 process gets access to the
29265fd92e65SH. J. Lu	  full 64-bit register file and wide data path while leaving
29275fd92e65SH. J. Lu	  pointers at 32 bits for smaller memory footprint.
29285fd92e65SH. J. Lu
29295fd92e65SH. J. Lu	  You will need a recent binutils (2.22 or later) with
29305fd92e65SH. J. Lu	  elf32_x86_64 support enabled to compile a kernel with this
29315fd92e65SH. J. Lu	  option set.
29325fd92e65SH. J. Lu
2933953fee1dSIngo Molnarconfig COMPAT_32
2934953fee1dSIngo Molnar	def_bool y
2935953fee1dSIngo Molnar	depends on IA32_EMULATION || X86_32
2936953fee1dSIngo Molnar	select HAVE_UID16
2937953fee1dSIngo Molnar	select OLD_SIGSUSPEND3
2938953fee1dSIngo Molnar
2939e279b6c1SSam Ravnborgconfig COMPAT
29403c2362e6SHarvey Harrison	def_bool y
29410bf62763SH. Peter Anvin	depends on IA32_EMULATION || X86_X32
2942e279b6c1SSam Ravnborg
29433120e25eSJan Beulichif COMPAT
2944e279b6c1SSam Ravnborgconfig COMPAT_FOR_U64_ALIGNMENT
29453120e25eSJan Beulich	def_bool y
2946e279b6c1SSam Ravnborg
2947e279b6c1SSam Ravnborgconfig SYSVIPC_COMPAT
29483c2362e6SHarvey Harrison	def_bool y
29493120e25eSJan Beulich	depends on SYSVIPC
29503120e25eSJan Beulichendif
2951ee009e4aSDavid Howells
2952e279b6c1SSam Ravnborgendmenu
2953e279b6c1SSam Ravnborg
2954e279b6c1SSam Ravnborg
2955e5beae16SKeith Packardconfig HAVE_ATOMIC_IOMAP
2956e5beae16SKeith Packard	def_bool y
2957e5beae16SKeith Packard	depends on X86_32
2958e5beae16SKeith Packard
29594692d77fSAlessandro Rubiniconfig X86_DEV_DMA_OPS
29604692d77fSAlessandro Rubini	bool
2961f7219a53SAlessandro Rubini
2962e279b6c1SSam Ravnborgsource "drivers/firmware/Kconfig"
2963e279b6c1SSam Ravnborg
2964edf88417SAvi Kivitysource "arch/x86/kvm/Kconfig"
2965