xref: /openbmc/linux/arch/x86/Kconfig (revision 098c0a373cdd51d3a735da7394acd6e57fae45a0)
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"
6a7f7f624SMasahiro Yamada	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
17157e118bSThomas Gleixner	select GENERIC_VDSO_32
18117ed454SThomas Gleixner	select HAVE_DEBUG_STACKOVERFLOW
19157e118bSThomas Gleixner	select KMAP_LOCAL
20341c787eSIngo Molnar	select MODULES_USE_ELF_REL
21341c787eSIngo Molnar	select OLD_SIGACTION
222ca408d9SBrian Gerst	select ARCH_SPLIT_ARG64
23daa93fabSSam Ravnborg
24daa93fabSSam Ravnborgconfig X86_64
253120e25eSJan Beulich	def_bool y
263120e25eSJan Beulich	depends on 64BIT
27d94e0685SIngo Molnar	# Options that are inherently 64-bit kernel only:
284eb0716eSAlexandre Ghiti	select ARCH_HAS_GIGANTIC_PAGE
29c12d3362SArd Biesheuvel	select ARCH_SUPPORTS_INT128 if CC_HAS_INT128
300bff0aaeSSuren Baghdasaryan	select ARCH_SUPPORTS_PER_VMA_LOCK
31d94e0685SIngo Molnar	select ARCH_USE_CMPXCHG_LOCKREF
32d94e0685SIngo Molnar	select HAVE_ARCH_SOFT_DIRTY
33d94e0685SIngo Molnar	select MODULES_USE_ELF_RELA
34f616ab59SChristoph Hellwig	select NEED_DMA_MAP_STATE
3509230cbcSChristoph Hellwig	select SWIOTLB
367facdc42SAl Viro	select ARCH_HAS_ELFCORE_COMPAT
3763703f37SKefeng Wang	select ZONE_DMA32
381032c0baSSam Ravnborg
39518049d9SSteven Rostedt (VMware)config FORCE_DYNAMIC_FTRACE
40518049d9SSteven Rostedt (VMware)	def_bool y
41518049d9SSteven Rostedt (VMware)	depends on X86_32
42518049d9SSteven Rostedt (VMware)	depends on FUNCTION_TRACER
43518049d9SSteven Rostedt (VMware)	select DYNAMIC_FTRACE
44518049d9SSteven Rostedt (VMware)	help
45518049d9SSteven Rostedt (VMware)	  We keep the static function tracing (!DYNAMIC_FTRACE) around
46518049d9SSteven Rostedt (VMware)	  in order to test the non static function tracing in the
47518049d9SSteven Rostedt (VMware)	  generic code, as other architectures still use it. But we
48518049d9SSteven Rostedt (VMware)	  only need to keep it around for x86_64. No need to keep it
49518049d9SSteven Rostedt (VMware)	  for x86_32. For x86_32, force DYNAMIC_FTRACE.
50d94e0685SIngo Molnar#
51d94e0685SIngo Molnar# Arch settings
52d94e0685SIngo Molnar#
53d94e0685SIngo Molnar# ( Note that options that are marked 'if X86_64' could in principle be
54d94e0685SIngo Molnar#   ported to 32-bit as well. )
55d94e0685SIngo Molnar#
568d5fffb9SSam Ravnborgconfig X86
573c2362e6SHarvey Harrison	def_bool y
58c763ea26SIngo Molnar	#
59c763ea26SIngo Molnar	# Note: keep this list sorted alphabetically
60c763ea26SIngo Molnar	#
616471b825SIngo Molnar	select ACPI_LEGACY_TABLES_LOOKUP	if ACPI
626e0a0ea1SGraeme Gregory	select ACPI_SYSTEM_POWER_STATES_SUPPORT	if ACPI
63942fa985SYury Norov	select ARCH_32BIT_OFF_T			if X86_32
642a21ad57SThomas Gleixner	select ARCH_CLOCKSOURCE_INIT
658292f4f8SSean Christopherson	select ARCH_CONFIGURES_CPU_MITIGATIONS
661f6d3a8fSMasami Hiramatsu	select ARCH_CORRECT_STACKTRACE_ON_KRETPROBE
671e866974SAnshuman Khandual	select ARCH_ENABLE_HUGEPAGE_MIGRATION if X86_64 && HUGETLB_PAGE && MIGRATION
685c11f00bSDavid Hildenbrand	select ARCH_ENABLE_MEMORY_HOTPLUG if X86_64
6991024b3cSAnshuman Khandual	select ARCH_ENABLE_MEMORY_HOTREMOVE if MEMORY_HOTPLUG
70cebc774fSAnshuman Khandual	select ARCH_ENABLE_SPLIT_PMD_PTLOCK if (PGTABLE_LEVELS > 2) && (X86_64 || X86_PAE)
711e866974SAnshuman Khandual	select ARCH_ENABLE_THP_MIGRATION if X86_64 && TRANSPARENT_HUGEPAGE
7291dda51aSAleksey Makarov	select ARCH_HAS_ACPI_TABLE_UPGRADE	if ACPI
73c2280be8SAnshuman Khandual	select ARCH_HAS_CACHE_LINE_SIZE
741156b441SDavidlohr Bueso	select ARCH_HAS_CPU_CACHE_INVALIDATE_MEMREGION
757c7077a7SThomas Gleixner	select ARCH_HAS_CPU_FINALIZE_INIT
762792d84eSKees Cook	select ARCH_HAS_CURRENT_STACK_POINTER
77fa5b6ec9SLaura Abbott	select ARCH_HAS_DEBUG_VIRTUAL
78399145f9SAnshuman Khandual	select ARCH_HAS_DEBUG_VM_PGTABLE	if !X86_PAE
7921266be9SDan Williams	select ARCH_HAS_DEVMEM_IS_ALLOWED
80b1a57bbfSDouglas Anderson	select ARCH_HAS_EARLY_DEBUG		if KGDB
816471b825SIngo Molnar	select ARCH_HAS_ELF_RANDOMIZE
8272d93104SLinus Torvalds	select ARCH_HAS_FAST_MULTIPLIER
836974f0c4SDaniel Micay	select ARCH_HAS_FORTIFY_SOURCE
84957e3facSRiku Voipio	select ARCH_HAS_GCOV_PROFILE_ALL
85bece04b5SMarco Elver	select ARCH_HAS_KCOV			if X86_64
860c9c1d56SThiago Jung Bauermann	select ARCH_HAS_MEM_ENCRYPT
8710bcc80eSMathieu Desnoyers	select ARCH_HAS_MEMBARRIER_SYNC_CORE
8849f88c70SPaul E. McKenney	select ARCH_HAS_NMI_SAFE_THIS_CPU_OPS
890ebeea8cSDaniel Borkmann	select ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE
90c763ea26SIngo Molnar	select ARCH_HAS_PMEM_API		if X86_64
9117596731SRobin Murphy	select ARCH_HAS_PTE_DEVMAP		if X86_64
923010a5eaSLaurent Dufour	select ARCH_HAS_PTE_SPECIAL
93eed9a328SYu Zhao	select ARCH_HAS_NONLEAF_PMD_YOUNG	if PGTABLE_LEVELS > 2
940aed55afSDan Williams	select ARCH_HAS_UACCESS_FLUSHCACHE	if X86_64
95ec6347bbSDan Williams	select ARCH_HAS_COPY_MC			if X86_64
96d2852a22SDaniel Borkmann	select ARCH_HAS_SET_MEMORY
97d253ca0cSRick Edgecombe	select ARCH_HAS_SET_DIRECT_MAP
98ad21fc4fSLaura Abbott	select ARCH_HAS_STRICT_KERNEL_RWX
99ad21fc4fSLaura Abbott	select ARCH_HAS_STRICT_MODULE_RWX
100ac1ab12aSMathieu Desnoyers	select ARCH_HAS_SYNC_CORE_BEFORE_USERMODE
10125c619e5SBrian Gerst	select ARCH_HAS_SYSCALL_WRAPPER
102c6d30853SAndrey Ryabinin	select ARCH_HAS_UBSAN_SANITIZE_ALL
1037e01ccb4SZong Li	select ARCH_HAS_DEBUG_WX
10463703f37SKefeng Wang	select ARCH_HAS_ZONE_DMA_SET if EXPERT
1056471b825SIngo Molnar	select ARCH_HAVE_NMI_SAFE_CMPXCHG
10604d5ea46SAneesh Kumar K.V	select ARCH_MHP_MEMMAP_ON_MEMORY_ENABLE
1076471b825SIngo Molnar	select ARCH_MIGHT_HAVE_ACPI_PDC		if ACPI
10877fbbc81SMark Salter	select ARCH_MIGHT_HAVE_PC_PARPORT
1095e2c18c0SMark Salter	select ARCH_MIGHT_HAVE_PC_SERIO
1103599fe12SThomas Gleixner	select ARCH_STACKWALK
1112c870e61SArnd Bergmann	select ARCH_SUPPORTS_ACPI
1126471b825SIngo Molnar	select ARCH_SUPPORTS_ATOMIC_RMW
1135d6ad668SMike Rapoport	select ARCH_SUPPORTS_DEBUG_PAGEALLOC
114d283d422SPasha Tatashin	select ARCH_SUPPORTS_PAGE_TABLE_CHECK	if X86_64
1156471b825SIngo Molnar	select ARCH_SUPPORTS_NUMA_BALANCING	if X86_64
11614df3267SThomas Gleixner	select ARCH_SUPPORTS_KMAP_LOCAL_FORCE_MAP	if NR_CPUS <= 4096
1173c516f89SSami Tolvanen	select ARCH_SUPPORTS_CFI_CLANG		if X86_64
1183c516f89SSami Tolvanen	select ARCH_USES_CFI_TRAPS		if X86_64 && CFI_CLANG
119583bfd48SNathan Chancellor	select ARCH_SUPPORTS_LTO_CLANG
120583bfd48SNathan Chancellor	select ARCH_SUPPORTS_LTO_CLANG_THIN
1216471b825SIngo Molnar	select ARCH_USE_BUILTIN_BSWAP
122dce44566SAnshuman Khandual	select ARCH_USE_MEMTEST
1236471b825SIngo Molnar	select ARCH_USE_QUEUED_RWLOCKS
1246471b825SIngo Molnar	select ARCH_USE_QUEUED_SPINLOCKS
1252ce0d7f9SMark Brown	select ARCH_USE_SYM_ANNOTATIONS
126ce4a4e56SAndy Lutomirski	select ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH
12781c22041SDaniel Borkmann	select ARCH_WANT_DEFAULT_BPF_JIT	if X86_64
128c763ea26SIngo Molnar	select ARCH_WANTS_DYNAMIC_TASK_STRUCT
12951c2ee6dSNick Desaulniers	select ARCH_WANTS_NO_INSTR
13007431506SAnshuman Khandual	select ARCH_WANT_GENERAL_HUGETLB
1313876d4a3SAlexandre Ghiti	select ARCH_WANT_HUGE_PMD_SHARE
13259612b24SNathan Chancellor	select ARCH_WANT_LD_ORPHAN_WARN
1330b6f1582SAneesh Kumar K.V	select ARCH_WANT_OPTIMIZE_DAX_VMEMMAP	if X86_64
1340b6f1582SAneesh Kumar K.V	select ARCH_WANT_OPTIMIZE_HUGETLB_VMEMMAP	if X86_64
13538d8b4e6SHuang Ying	select ARCH_WANTS_THP_SWAP		if X86_64
136b5f06f64SBalbir Singh	select ARCH_HAS_PARANOID_L1D_FLUSH
13710916706SShile Zhang	select BUILDTIME_TABLE_SORT
1386471b825SIngo Molnar	select CLKEVT_I8253
1396471b825SIngo Molnar	select CLOCKSOURCE_VALIDATE_LAST_CYCLE
1406471b825SIngo Molnar	select CLOCKSOURCE_WATCHDOG
1417cf8f44aSAlexander Potapenko	# Word-size accesses may read uninitialized data past the trailing \0
1427cf8f44aSAlexander Potapenko	# in strings and cause false KMSAN reports.
1437cf8f44aSAlexander Potapenko	select DCACHE_WORD_ACCESS		if !KMSAN
1443aac3ebeSThomas Gleixner	select DYNAMIC_SIGFRAME
14545471cd9SLinus Torvalds	select EDAC_ATOMIC_SCRUB
14645471cd9SLinus Torvalds	select EDAC_SUPPORT
1476471b825SIngo Molnar	select GENERIC_CLOCKEVENTS_BROADCAST	if X86_64 || (X86_32 && X86_LOCAL_APIC)
1486471b825SIngo Molnar	select GENERIC_CLOCKEVENTS_MIN_ADJUST
1496471b825SIngo Molnar	select GENERIC_CMOS_UPDATE
1506471b825SIngo Molnar	select GENERIC_CPU_AUTOPROBE
15161dc0f55SThomas Gleixner	select GENERIC_CPU_VULNERABILITIES
1526471b825SIngo Molnar	select GENERIC_EARLY_IOREMAP
15327d6b4d1SThomas Gleixner	select GENERIC_ENTRY
1546471b825SIngo Molnar	select GENERIC_IOMAP
155c7d6c9ddSThomas Gleixner	select GENERIC_IRQ_EFFECTIVE_AFF_MASK	if SMP
1560fa115daSThomas Gleixner	select GENERIC_IRQ_MATRIX_ALLOCATOR	if X86_LOCAL_APIC
157ad7a929fSThomas Gleixner	select GENERIC_IRQ_MIGRATION		if SMP
1586471b825SIngo Molnar	select GENERIC_IRQ_PROBE
159c201c917SThomas Gleixner	select GENERIC_IRQ_RESERVATION_MODE
1606471b825SIngo Molnar	select GENERIC_IRQ_SHOW
1616471b825SIngo Molnar	select GENERIC_PENDING_IRQ		if SMP
1622ae27137SSteven Price	select GENERIC_PTDUMP
1636471b825SIngo Molnar	select GENERIC_SMP_IDLE_THREAD
1646471b825SIngo Molnar	select GENERIC_TIME_VSYSCALL
1657ac87074SVincenzo Frascino	select GENERIC_GETTIMEOFDAY
166550a77a7SDmitry Safonov	select GENERIC_VDSO_TIME_NS
1676ca297d4SPeter Zijlstra	select GUP_GET_PXX_LOW_HIGH		if X86_PAE
16817e5888eSHans de Goede	select HARDIRQS_SW_RESEND
1697edaeb68SThomas Gleixner	select HARDLOCKUP_CHECK_TIMESTAMP	if X86_64
170fcbfe812SNiklas Schnelle	select HAS_IOPORT
1716471b825SIngo Molnar	select HAVE_ACPI_APEI			if ACPI
1726471b825SIngo Molnar	select HAVE_ACPI_APEI_NMI		if ACPI
1736471b825SIngo Molnar	select HAVE_ALIGNED_STRUCT_PAGE		if SLUB
1746471b825SIngo Molnar	select HAVE_ARCH_AUDITSYSCALL
1756471b825SIngo Molnar	select HAVE_ARCH_HUGE_VMAP		if X86_64 || X86_PAE
176eed1fceeSSong Liu	select HAVE_ARCH_HUGE_VMALLOC		if X86_64
1776471b825SIngo Molnar	select HAVE_ARCH_JUMP_LABEL
178b34006c4SArd Biesheuvel	select HAVE_ARCH_JUMP_LABEL_RELATIVE
179d17a1d97SAndrey Ryabinin	select HAVE_ARCH_KASAN			if X86_64
1800609ae01SDaniel Axtens	select HAVE_ARCH_KASAN_VMALLOC		if X86_64
1811dc0da6eSAlexander Potapenko	select HAVE_ARCH_KFENCE
1824ca8cc8dSAlexander Potapenko	select HAVE_ARCH_KMSAN			if X86_64
1836471b825SIngo Molnar	select HAVE_ARCH_KGDB
1849e08f57dSDaniel Cashman	select HAVE_ARCH_MMAP_RND_BITS		if MMU
1859e08f57dSDaniel Cashman	select HAVE_ARCH_MMAP_RND_COMPAT_BITS	if MMU && COMPAT
1861b028f78SDmitry Safonov	select HAVE_ARCH_COMPAT_MMAP_BASES	if MMU && COMPAT
187271ca788SArd Biesheuvel	select HAVE_ARCH_PREL32_RELOCATIONS
1886471b825SIngo Molnar	select HAVE_ARCH_SECCOMP_FILTER
189f7d83c1cSKees Cook	select HAVE_ARCH_THREAD_STRUCT_WHITELIST
190afaef01cSAlexander Popov	select HAVE_ARCH_STACKLEAK
1916471b825SIngo Molnar	select HAVE_ARCH_TRACEHOOK
1926471b825SIngo Molnar	select HAVE_ARCH_TRANSPARENT_HUGEPAGE
193a00cc7d9SMatthew Wilcox	select HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD if X86_64
194b64d8d1eSPeter Xu	select HAVE_ARCH_USERFAULTFD_WP         if X86_64 && USERFAULTFD
1957677f7fdSAxel Rasmussen	select HAVE_ARCH_USERFAULTFD_MINOR	if X86_64 && USERFAULTFD
196e37e43a4SAndy Lutomirski	select HAVE_ARCH_VMAP_STACK		if X86_64
197fe950f60SKees Cook	select HAVE_ARCH_RANDOMIZE_KSTACK_OFFSET
198c763ea26SIngo Molnar	select HAVE_ARCH_WITHIN_STACK_FRAMES
1992ff2b7ecSMasahiro Yamada	select HAVE_ASM_MODVERSIONS
2006471b825SIngo Molnar	select HAVE_CMPXCHG_DOUBLE
2016471b825SIngo Molnar	select HAVE_CMPXCHG_LOCAL
20224a9c541SFrederic Weisbecker	select HAVE_CONTEXT_TRACKING_USER		if X86_64
20324a9c541SFrederic Weisbecker	select HAVE_CONTEXT_TRACKING_USER_OFFSTACK	if HAVE_CONTEXT_TRACKING_USER
2046471b825SIngo Molnar	select HAVE_C_RECORDMCOUNT
20503f16cd0SJosh Poimboeuf	select HAVE_OBJTOOL_MCOUNT		if HAVE_OBJTOOL
206280981d6SSathvika Vasireddy	select HAVE_OBJTOOL_NOP_MCOUNT		if HAVE_OBJTOOL_MCOUNT
2074ed308c4SSteven Rostedt (Google)	select HAVE_BUILDTIME_MCOUNT_SORT
2086471b825SIngo Molnar	select HAVE_DEBUG_KMEMLEAK
2099c5a3621SAkinobu Mita	select HAVE_DMA_CONTIGUOUS
210677aa9f7SSteven Rostedt	select HAVE_DYNAMIC_FTRACE
21106aeaaeaSMasami Hiramatsu	select HAVE_DYNAMIC_FTRACE_WITH_REGS
21202a474caSSteven Rostedt (VMware)	select HAVE_DYNAMIC_FTRACE_WITH_ARGS	if X86_64
213562955feSSteven Rostedt (VMware)	select HAVE_DYNAMIC_FTRACE_WITH_DIRECT_CALLS
214c316eb44SHeiko Carstens	select HAVE_SAMPLE_FTRACE_DIRECT	if X86_64
215503e4510SHeiko Carstens	select HAVE_SAMPLE_FTRACE_DIRECT_MULTI	if X86_64
21603f5781bSWang YanQing	select HAVE_EBPF_JIT
21758340a07SJohannes Berg	select HAVE_EFFICIENT_UNALIGNED_ACCESS
2187c376f91SArnd Bergmann	select HAVE_EISA			if X86_32
2195f56a5dfSJiri Slaby	select HAVE_EXIT_THREAD
22067a929e0SChristoph Hellwig	select HAVE_FAST_GUP
221644e0e8dSSteven Rostedt (VMware)	select HAVE_FENTRY			if X86_64 || DYNAMIC_FTRACE
2226471b825SIngo Molnar	select HAVE_FTRACE_MCOUNT_RECORD
223d938ba17SDonglin Peng	select HAVE_FUNCTION_GRAPH_RETVAL	if HAVE_FUNCTION_GRAPH_TRACER
2244a30e4c9SSteven Rostedt (VMware)	select HAVE_FUNCTION_GRAPH_TRACER	if X86_32 || (X86_64 && DYNAMIC_FTRACE)
2256471b825SIngo Molnar	select HAVE_FUNCTION_TRACER
2266b90bd4bSEmese Revfy	select HAVE_GCC_PLUGINS
2270067f129SK.Prasad	select HAVE_HW_BREAKPOINT
2286471b825SIngo Molnar	select HAVE_IOREMAP_PROT
229624db9eaSThomas Gleixner	select HAVE_IRQ_EXIT_ON_IRQ_STACK	if X86_64
2306471b825SIngo Molnar	select HAVE_IRQ_TIME_ACCOUNTING
2314ab7674fSJosh Poimboeuf	select HAVE_JUMP_LABEL_HACK		if HAVE_OBJTOOL
2326471b825SIngo Molnar	select HAVE_KERNEL_BZIP2
2336471b825SIngo Molnar	select HAVE_KERNEL_GZIP
2346471b825SIngo Molnar	select HAVE_KERNEL_LZ4
2356471b825SIngo Molnar	select HAVE_KERNEL_LZMA
2366471b825SIngo Molnar	select HAVE_KERNEL_LZO
2376471b825SIngo Molnar	select HAVE_KERNEL_XZ
238fb46d057SNick Terrell	select HAVE_KERNEL_ZSTD
2396471b825SIngo Molnar	select HAVE_KPROBES
2406471b825SIngo Molnar	select HAVE_KPROBES_ON_FTRACE
241540adea3SMasami Hiramatsu	select HAVE_FUNCTION_ERROR_INJECTION
2426471b825SIngo Molnar	select HAVE_KRETPROBES
243f3a112c0SMasami Hiramatsu	select HAVE_RETHOOK
2446471b825SIngo Molnar	select HAVE_KVM
2456471b825SIngo Molnar	select HAVE_LIVEPATCH			if X86_64
2460102752eSFrederic Weisbecker	select HAVE_MIXED_BREAKPOINTS_REGS
247ee9f8fceSJosh Poimboeuf	select HAVE_MOD_ARCH_SPECIFIC
2489f132f7eSJoel Fernandes (Google)	select HAVE_MOVE_PMD
249be37c98dSKalesh Singh	select HAVE_MOVE_PUD
25022102f45SJosh Poimboeuf	select HAVE_NOINSTR_HACK		if HAVE_OBJTOOL
25142a0bb3fSPetr Mladek	select HAVE_NMI
252489e355bSJosh Poimboeuf	select HAVE_NOINSTR_VALIDATION		if HAVE_OBJTOOL
25303f16cd0SJosh Poimboeuf	select HAVE_OBJTOOL			if X86_64
2546471b825SIngo Molnar	select HAVE_OPTPROBES
2556471b825SIngo Molnar	select HAVE_PCSPKR_PLATFORM
2566471b825SIngo Molnar	select HAVE_PERF_EVENTS
257c01d4323SFrederic Weisbecker	select HAVE_PERF_EVENTS_NMI
25892e5aae4SNicholas Piggin	select HAVE_HARDLOCKUP_DETECTOR_PERF	if PERF_EVENTS && HAVE_PERF_EVENTS_NMI
259eb01d42aSChristoph Hellwig	select HAVE_PCI
260c5e63197SJiri Olsa	select HAVE_PERF_REGS
261c5ebcedbSJiri Olsa	select HAVE_PERF_USER_STACK_DUMP
262ff2e6d72SPeter Zijlstra	select MMU_GATHER_RCU_TABLE_FREE	if PARAVIRT
2631e9fdf21SPeter Zijlstra	select MMU_GATHER_MERGE_VMAS
26400998085SThomas Gleixner	select HAVE_POSIX_CPU_TIMERS_TASK_WORK
2656471b825SIngo Molnar	select HAVE_REGS_AND_STACK_ACCESS_API
26603f16cd0SJosh Poimboeuf	select HAVE_RELIABLE_STACKTRACE		if UNWINDER_ORC || STACK_VALIDATION
2673c88ee19SMasami Hiramatsu	select HAVE_FUNCTION_ARG_ACCESS_API
2687ecd19cfSKefeng Wang	select HAVE_SETUP_PER_CPU_AREA
269cd1a41ceSThomas Gleixner	select HAVE_SOFTIRQ_ON_OWN_STACK
270d148eac0SMasahiro Yamada	select HAVE_STACKPROTECTOR		if CC_HAS_SANE_STACKPROTECTOR
27103f16cd0SJosh Poimboeuf	select HAVE_STACK_VALIDATION		if HAVE_OBJTOOL
272e6d6c071SJosh Poimboeuf	select HAVE_STATIC_CALL
27303f16cd0SJosh Poimboeuf	select HAVE_STATIC_CALL_INLINE		if HAVE_OBJTOOL
27499cf983cSMark Rutland	select HAVE_PREEMPT_DYNAMIC_CALL
275d6761b8fSMathieu Desnoyers	select HAVE_RSEQ
27609498135SMiguel Ojeda	select HAVE_RUST			if X86_64
2776471b825SIngo Molnar	select HAVE_SYSCALL_TRACEPOINTS
2785f3da8c0SJosh Poimboeuf	select HAVE_UACCESS_VALIDATION		if HAVE_OBJTOOL
2796471b825SIngo Molnar	select HAVE_UNSTABLE_SCHED_CLOCK
2807c68af6eSAvi Kivity	select HAVE_USER_RETURN_NOTIFIER
2817ac87074SVincenzo Frascino	select HAVE_GENERIC_VDSO
2820c7ffa32SThomas Gleixner	select HOTPLUG_PARALLEL			if SMP && X86_64
28305736e4aSThomas Gleixner	select HOTPLUG_SMT			if SMP
2840c7ffa32SThomas Gleixner	select HOTPLUG_SPLIT_STARTUP		if SMP && X86_32
285c0185808SThomas Gleixner	select IRQ_FORCED_THREADING
286c2508ec5SLinus Torvalds	select LOCK_MM_AND_FIND_VMA
2877ecd19cfSKefeng Wang	select NEED_PER_CPU_EMBED_FIRST_CHUNK
2887ecd19cfSKefeng Wang	select NEED_PER_CPU_PAGE_FIRST_CHUNK
28986596f0aSChristoph Hellwig	select NEED_SG_DMA_LENGTH
2902eac9c2dSChristoph Hellwig	select PCI_DOMAINS			if PCI
291625210cfSSinan Kaya	select PCI_LOCKLESS_CONFIG		if PCI
2926471b825SIngo Molnar	select PERF_EVENTS
2933195ef59SPrarit Bhargava	select RTC_LIB
294d6faca40SArnd Bergmann	select RTC_MC146818_LIB
2956471b825SIngo Molnar	select SPARSE_IRQ
2966471b825SIngo Molnar	select SYSCTL_EXCEPTION_TRACE
29715f4eae7SAndy Lutomirski	select THREAD_INFO_IN_TASK
2984aae683fSMasahiro Yamada	select TRACE_IRQFLAGS_SUPPORT
2994510bffbSMark Rutland	select TRACE_IRQFLAGS_NMI_SUPPORT
3006471b825SIngo Molnar	select USER_STACKTRACE_SUPPORT
3013b02a051SIngo Molnar	select HAVE_ARCH_KCSAN			if X86_64
3020c608dadSAubrey Li	select PROC_PID_ARCH_STATUS		if PROC_FS
30350468e43SJarkko Sakkinen	select HAVE_ARCH_NODE_DEV_GROUP		if X86_SGX
304d49a0626SPeter Zijlstra	select FUNCTION_ALIGNMENT_16B		if X86_64 || X86_ALIGNMENT_16
305d49a0626SPeter Zijlstra	select FUNCTION_ALIGNMENT_4B
3069e2b4be3SNayna Jain	imply IMA_SECURE_AND_OR_TRUSTED_BOOT    if EFI
307ceea991aSJiri Olsa	select HAVE_DYNAMIC_FTRACE_NO_PATCHABLE
3087d8330a5SBalbir Singh
309ba7e4d13SIngo Molnarconfig INSTRUCTION_DECODER
3103120e25eSJan Beulich	def_bool y
3113120e25eSJan Beulich	depends on KPROBES || PERF_EVENTS || UPROBES
312ba7e4d13SIngo Molnar
31351b26adaSLinus Torvaldsconfig OUTPUT_FORMAT
31451b26adaSLinus Torvalds	string
31551b26adaSLinus Torvalds	default "elf32-i386" if X86_32
31651b26adaSLinus Torvalds	default "elf64-x86-64" if X86_64
31751b26adaSLinus Torvalds
3188d5fffb9SSam Ravnborgconfig LOCKDEP_SUPPORT
3193c2362e6SHarvey Harrison	def_bool y
3208d5fffb9SSam Ravnborg
3218d5fffb9SSam Ravnborgconfig STACKTRACE_SUPPORT
3223c2362e6SHarvey Harrison	def_bool y
3238d5fffb9SSam Ravnborg
3248d5fffb9SSam Ravnborgconfig MMU
3253c2362e6SHarvey Harrison	def_bool y
3268d5fffb9SSam Ravnborg
3279e08f57dSDaniel Cashmanconfig ARCH_MMAP_RND_BITS_MIN
3289e08f57dSDaniel Cashman	default 28 if 64BIT
3299e08f57dSDaniel Cashman	default 8
3309e08f57dSDaniel Cashman
3319e08f57dSDaniel Cashmanconfig ARCH_MMAP_RND_BITS_MAX
3329e08f57dSDaniel Cashman	default 32 if 64BIT
3339e08f57dSDaniel Cashman	default 16
3349e08f57dSDaniel Cashman
3359e08f57dSDaniel Cashmanconfig ARCH_MMAP_RND_COMPAT_BITS_MIN
3369e08f57dSDaniel Cashman	default 8
3379e08f57dSDaniel Cashman
3389e08f57dSDaniel Cashmanconfig ARCH_MMAP_RND_COMPAT_BITS_MAX
3399e08f57dSDaniel Cashman	default 16
3409e08f57dSDaniel Cashman
3418d5fffb9SSam Ravnborgconfig SBUS
3428d5fffb9SSam Ravnborg	bool
3438d5fffb9SSam Ravnborg
3448d5fffb9SSam Ravnborgconfig GENERIC_ISA_DMA
3453120e25eSJan Beulich	def_bool y
3463120e25eSJan Beulich	depends on ISA_DMA_API
3478d5fffb9SSam Ravnborg
348d911c67eSAlexander Potapenkoconfig GENERIC_CSUM
349d911c67eSAlexander Potapenko	bool
350d911c67eSAlexander Potapenko	default y if KMSAN || KASAN
351d911c67eSAlexander Potapenko
3528d5fffb9SSam Ravnborgconfig GENERIC_BUG
3533c2362e6SHarvey Harrison	def_bool y
3548d5fffb9SSam Ravnborg	depends on BUG
355b93a531eSJan Beulich	select GENERIC_BUG_RELATIVE_POINTERS if X86_64
356b93a531eSJan Beulich
357b93a531eSJan Beulichconfig GENERIC_BUG_RELATIVE_POINTERS
358b93a531eSJan Beulich	bool
3598d5fffb9SSam Ravnborg
3608d5fffb9SSam Ravnborgconfig ARCH_MAY_HAVE_PC_FDC
3613120e25eSJan Beulich	def_bool y
3623120e25eSJan Beulich	depends on ISA_DMA_API
3638d5fffb9SSam Ravnborg
3641032c0baSSam Ravnborgconfig GENERIC_CALIBRATE_DELAY
3651032c0baSSam Ravnborg	def_bool y
3661032c0baSSam Ravnborg
3679a0b8415Svenkatesh.pallipadi@intel.comconfig ARCH_HAS_CPU_RELAX
3689a0b8415Svenkatesh.pallipadi@intel.com	def_bool y
3698d5fffb9SSam Ravnborg
370801e4062SJohannes Bergconfig ARCH_HIBERNATION_POSSIBLE
371801e4062SJohannes Berg	def_bool y
372801e4062SJohannes Berg
373f4cb5700SJohannes Bergconfig ARCH_SUSPEND_POSSIBLE
374f4cb5700SJohannes Berg	def_bool y
375f4cb5700SJohannes Berg
3768d5fffb9SSam Ravnborgconfig AUDIT_ARCH
377e0fd24a3SJan Beulich	def_bool y if X86_64
3788d5fffb9SSam Ravnborg
379d6f2d75aSAndrey Ryabininconfig KASAN_SHADOW_OFFSET
380d6f2d75aSAndrey Ryabinin	hex
381d6f2d75aSAndrey Ryabinin	depends on KASAN
382d6f2d75aSAndrey Ryabinin	default 0xdffffc0000000000
383d6f2d75aSAndrey Ryabinin
38469575d38SShane Wangconfig HAVE_INTEL_TXT
38569575d38SShane Wang	def_bool y
3866ea30386SKees Cook	depends on INTEL_IOMMU && ACPI
38769575d38SShane Wang
3886b0c3d44SSam Ravnborgconfig X86_32_SMP
3896b0c3d44SSam Ravnborg	def_bool y
3906b0c3d44SSam Ravnborg	depends on X86_32 && SMP
3916b0c3d44SSam Ravnborg
3926b0c3d44SSam Ravnborgconfig X86_64_SMP
3936b0c3d44SSam Ravnborg	def_bool y
3946b0c3d44SSam Ravnborg	depends on X86_64 && SMP
3956b0c3d44SSam Ravnborg
3962b144498SSrikar Dronamrajuconfig ARCH_SUPPORTS_UPROBES
3972b144498SSrikar Dronamraju	def_bool y
3982b144498SSrikar Dronamraju
399d20642f0SRob Herringconfig FIX_EARLYCON_MEM
400d20642f0SRob Herring	def_bool y
401d20642f0SRob Herring
40294d49eb3SKirill A. Shutemovconfig DYNAMIC_PHYSICAL_MASK
40394d49eb3SKirill A. Shutemov	bool
40494d49eb3SKirill A. Shutemov
40598233368SKirill A. Shutemovconfig PGTABLE_LEVELS
40698233368SKirill A. Shutemov	int
40777ef56e4SKirill A. Shutemov	default 5 if X86_5LEVEL
40898233368SKirill A. Shutemov	default 4 if X86_64
40998233368SKirill A. Shutemov	default 3 if X86_PAE
41098233368SKirill A. Shutemov	default 2
41198233368SKirill A. Shutemov
4122a61f474SMasahiro Yamadaconfig CC_HAS_SANE_STACKPROTECTOR
4132a61f474SMasahiro Yamada	bool
4141b866781SNathan Chancellor	default $(success,$(srctree)/scripts/gcc-x86_64-has-stack-protector.sh $(CC) $(CLANG_FLAGS)) if 64BIT
4151b866781SNathan Chancellor	default $(success,$(srctree)/scripts/gcc-x86_32-has-stack-protector.sh $(CC) $(CLANG_FLAGS))
4162a61f474SMasahiro Yamada	help
4172a61f474SMasahiro Yamada	  We have to make sure stack protector is unconditionally disabled if
4183fb0fdb3SAndy Lutomirski	  the compiler produces broken code or if it does not let us control
4193fb0fdb3SAndy Lutomirski	  the segment on 32-bit kernels.
4202a61f474SMasahiro Yamada
421506f1d07SSam Ravnborgmenu "Processor type and features"
422506f1d07SSam Ravnborg
423506f1d07SSam Ravnborgconfig SMP
424506f1d07SSam Ravnborg	bool "Symmetric multi-processing support"
425a7f7f624SMasahiro Yamada	help
426506f1d07SSam Ravnborg	  This enables support for systems with more than one CPU. If you have
4274a474157SRobert Graffham	  a system with only one CPU, say N. If you have a system with more
4284a474157SRobert Graffham	  than one CPU, say Y.
429506f1d07SSam Ravnborg
4304a474157SRobert Graffham	  If you say N here, the kernel will run on uni- and multiprocessor
431506f1d07SSam Ravnborg	  machines, but will use only one CPU of a multiprocessor machine. If
432506f1d07SSam Ravnborg	  you say Y here, the kernel will run on many, but not all,
4334a474157SRobert Graffham	  uniprocessor machines. On a uniprocessor machine, the kernel
434506f1d07SSam Ravnborg	  will run faster if you say N here.
435506f1d07SSam Ravnborg
436506f1d07SSam Ravnborg	  Note that if you say Y here and choose architecture "586" or
437506f1d07SSam Ravnborg	  "Pentium" under "Processor family", the kernel will not work on 486
438506f1d07SSam Ravnborg	  architectures. Similarly, multiprocessor kernels for the "PPro"
439506f1d07SSam Ravnborg	  architecture may not work on all Pentium based boards.
440506f1d07SSam Ravnborg
441506f1d07SSam Ravnborg	  People using multiprocessor machines who say Y here should also say
442506f1d07SSam Ravnborg	  Y to "Enhanced Real Time Clock Support", below. The "Advanced Power
443506f1d07SSam Ravnborg	  Management" code will be disabled if you say Y here.
444506f1d07SSam Ravnborg
445ff61f079SJonathan Corbet	  See also <file:Documentation/arch/x86/i386/IO-APIC.rst>,
4464f4cfa6cSMauro Carvalho Chehab	  <file:Documentation/admin-guide/lockup-watchdogs.rst> and the SMP-HOWTO available at
447506f1d07SSam Ravnborg	  <http://www.tldp.org/docs.html#howto>.
448506f1d07SSam Ravnborg
449506f1d07SSam Ravnborg	  If you don't know what to do here, say N.
450506f1d07SSam Ravnborg
45106cd9a7dSYinghai Luconfig X86_X2APIC
45206cd9a7dSYinghai Lu	bool "Support x2apic"
45319e3d60dSJan Kiszka	depends on X86_LOCAL_APIC && X86_64 && (IRQ_REMAP || HYPERVISOR_GUEST)
454a7f7f624SMasahiro Yamada	help
45506cd9a7dSYinghai Lu	  This enables x2apic support on CPUs that have this feature.
45606cd9a7dSYinghai Lu
45706cd9a7dSYinghai Lu	  This allows 32-bit apic IDs (so it can support very large systems),
45806cd9a7dSYinghai Lu	  and accesses the local apic via MSRs not via mmio.
45906cd9a7dSYinghai Lu
460b8d1d163SDaniel Sneddon	  Some Intel systems circa 2022 and later are locked into x2APIC mode
461b8d1d163SDaniel Sneddon	  and can not fall back to the legacy APIC modes if SGX or TDX are
462e3998434SMateusz Jończyk	  enabled in the BIOS. They will boot with very reduced functionality
463e3998434SMateusz Jończyk	  without enabling this option.
464b8d1d163SDaniel Sneddon
46506cd9a7dSYinghai Lu	  If you don't know what to do here, say N.
46606cd9a7dSYinghai Lu
4676695c85bSYinghai Luconfig X86_MPPARSE
4684590d98fSAndy Shevchenko	bool "Enable MPS table" if ACPI
4697a527688SJan Beulich	default y
4705ab74722SIngo Molnar	depends on X86_LOCAL_APIC
471a7f7f624SMasahiro Yamada	help
4726695c85bSYinghai Lu	  For old smp systems that do not have proper acpi support. Newer systems
4736695c85bSYinghai Lu	  (esp with 64bit cpus) with acpi support, MADT and DSDT will override it
4746695c85bSYinghai Lu
475ddd70cf9SJun Nakajimaconfig GOLDFISH
476ddd70cf9SJun Nakajima	def_bool y
477ddd70cf9SJun Nakajima	depends on X86_GOLDFISH
478ddd70cf9SJun Nakajima
479e6d42931SJohannes Weinerconfig X86_CPU_RESCTRL
480e6d42931SJohannes Weiner	bool "x86 CPU resource control support"
4816fe07ce3SBabu Moger	depends on X86 && (CPU_SUP_INTEL || CPU_SUP_AMD)
48259fe5a77SThomas Gleixner	select KERNFS
483e79f15a4SChen Yu	select PROC_CPU_RESCTRL		if PROC_FS
48478e99b4aSFenghua Yu	help
485e6d42931SJohannes Weiner	  Enable x86 CPU resource control support.
4866fe07ce3SBabu Moger
4876fe07ce3SBabu Moger	  Provide support for the allocation and monitoring of system resources
4886fe07ce3SBabu Moger	  usage by the CPU.
4896fe07ce3SBabu Moger
4906fe07ce3SBabu Moger	  Intel calls this Intel Resource Director Technology
4916fe07ce3SBabu Moger	  (Intel(R) RDT). More information about RDT can be found in the
4926fe07ce3SBabu Moger	  Intel x86 Architecture Software Developer Manual.
4936fe07ce3SBabu Moger
4946fe07ce3SBabu Moger	  AMD calls this AMD Platform Quality of Service (AMD QoS).
4956fe07ce3SBabu Moger	  More information about AMD QoS can be found in the AMD64 Technology
4966fe07ce3SBabu Moger	  Platform Quality of Service Extensions manual.
49778e99b4aSFenghua Yu
49878e99b4aSFenghua Yu	  Say N if unsure.
49978e99b4aSFenghua Yu
5008425091fSRavikiran G Thirumalaiif X86_32
501a0d0bb4dSRandy Dunlapconfig X86_BIGSMP
502a0d0bb4dSRandy Dunlap	bool "Support for big SMP systems with more than 8 CPUs"
503a0d0bb4dSRandy Dunlap	depends on SMP
504a7f7f624SMasahiro Yamada	help
505e133f6eaSRandy Dunlap	  This option is needed for the systems that have more than 8 CPUs.
506a0d0bb4dSRandy Dunlap
507c5c606d9SRavikiran G Thirumalaiconfig X86_EXTENDED_PLATFORM
508c5c606d9SRavikiran G Thirumalai	bool "Support for extended (non-PC) x86 platforms"
509c5c606d9SRavikiran G Thirumalai	default y
510a7f7f624SMasahiro Yamada	help
51106ac8346SIngo Molnar	  If you disable this option then the kernel will only support
51206ac8346SIngo Molnar	  standard PC platforms. (which covers the vast majority of
51306ac8346SIngo Molnar	  systems out there.)
51406ac8346SIngo Molnar
5158425091fSRavikiran G Thirumalai	  If you enable this option then you'll be able to select support
5168425091fSRavikiran G Thirumalai	  for the following (non-PC) 32 bit x86 platforms:
517cb7b8023SBen Hutchings		Goldfish (Android emulator)
5188425091fSRavikiran G Thirumalai		AMD Elan
5198425091fSRavikiran G Thirumalai		RDC R-321x SoC
5208425091fSRavikiran G Thirumalai		SGI 320/540 (Visual Workstation)
52183125a3aSAlessandro Rubini		STA2X11-based (e.g. Northville)
5223f4110a4SThomas Gleixner		Moorestown MID devices
52306ac8346SIngo Molnar
52406ac8346SIngo Molnar	  If you have one of these systems, or if you want to build a
52506ac8346SIngo Molnar	  generic distribution kernel, say Y here - otherwise say N.
526758cd94aSJuerg Haefligerendif # X86_32
52706ac8346SIngo Molnar
5288425091fSRavikiran G Thirumalaiif X86_64
5298425091fSRavikiran G Thirumalaiconfig X86_EXTENDED_PLATFORM
5308425091fSRavikiran G Thirumalai	bool "Support for extended (non-PC) x86 platforms"
5318425091fSRavikiran G Thirumalai	default y
532a7f7f624SMasahiro Yamada	help
5338425091fSRavikiran G Thirumalai	  If you disable this option then the kernel will only support
5348425091fSRavikiran G Thirumalai	  standard PC platforms. (which covers the vast majority of
5358425091fSRavikiran G Thirumalai	  systems out there.)
5368425091fSRavikiran G Thirumalai
5378425091fSRavikiran G Thirumalai	  If you enable this option then you'll be able to select support
5388425091fSRavikiran G Thirumalai	  for the following (non-PC) 64 bit x86 platforms:
53944b111b5SSteffen Persvold		Numascale NumaChip
5408425091fSRavikiran G Thirumalai		ScaleMP vSMP
5418425091fSRavikiran G Thirumalai		SGI Ultraviolet
5428425091fSRavikiran G Thirumalai
5438425091fSRavikiran G Thirumalai	  If you have one of these systems, or if you want to build a
5448425091fSRavikiran G Thirumalai	  generic distribution kernel, say Y here - otherwise say N.
545758cd94aSJuerg Haefligerendif # X86_64
546c5c606d9SRavikiran G Thirumalai# This is an alphabetically sorted list of 64 bit extended platforms
547c5c606d9SRavikiran G Thirumalai# Please maintain the alphabetic order if and when there are additions
54844b111b5SSteffen Persvoldconfig X86_NUMACHIP
54944b111b5SSteffen Persvold	bool "Numascale NumaChip"
55044b111b5SSteffen Persvold	depends on X86_64
55144b111b5SSteffen Persvold	depends on X86_EXTENDED_PLATFORM
55244b111b5SSteffen Persvold	depends on NUMA
55344b111b5SSteffen Persvold	depends on SMP
55444b111b5SSteffen Persvold	depends on X86_X2APIC
555f9726bfdSDaniel J Blueman	depends on PCI_MMCONFIG
556a7f7f624SMasahiro Yamada	help
55744b111b5SSteffen Persvold	  Adds support for Numascale NumaChip large-SMP systems. Needed to
55844b111b5SSteffen Persvold	  enable more than ~168 cores.
55944b111b5SSteffen Persvold	  If you don't have one of these, you should say N here.
56003b48632SNick Piggin
5616a48565eSIngo Molnarconfig X86_VSMP
562c5c606d9SRavikiran G Thirumalai	bool "ScaleMP vSMP"
5636276a074SBorislav Petkov	select HYPERVISOR_GUEST
5646a48565eSIngo Molnar	select PARAVIRT
5656a48565eSIngo Molnar	depends on X86_64 && PCI
566c5c606d9SRavikiran G Thirumalai	depends on X86_EXTENDED_PLATFORM
567ead91d4bSShai Fultheim	depends on SMP
568a7f7f624SMasahiro Yamada	help
5696a48565eSIngo Molnar	  Support for ScaleMP vSMP systems.  Say 'Y' here if this kernel is
5706a48565eSIngo Molnar	  supposed to run on these EM64T-based machines.  Only choose this option
5716a48565eSIngo Molnar	  if you have one of these machines.
5726a48565eSIngo Molnar
573c5c606d9SRavikiran G Thirumalaiconfig X86_UV
574c5c606d9SRavikiran G Thirumalai	bool "SGI Ultraviolet"
575c5c606d9SRavikiran G Thirumalai	depends on X86_64
576c5c606d9SRavikiran G Thirumalai	depends on X86_EXTENDED_PLATFORM
57754c28d29SJack Steiner	depends on NUMA
5781ecb4ae5SAndrew Morton	depends on EFI
579c2209ea5SIngo Molnar	depends on KEXEC_CORE
5809d6c26e7SSuresh Siddha	depends on X86_X2APIC
5811222e564SIngo Molnar	depends on PCI
582a7f7f624SMasahiro Yamada	help
583c5c606d9SRavikiran G Thirumalai	  This option is needed in order to support SGI Ultraviolet systems.
584c5c606d9SRavikiran G Thirumalai	  If you don't have one of these, you should say N here.
585c5c606d9SRavikiran G Thirumalai
586c5c606d9SRavikiran G Thirumalai# Following is an alphabetically sorted list of 32 bit extended platforms
587c5c606d9SRavikiran G Thirumalai# Please maintain the alphabetic order if and when there are additions
588506f1d07SSam Ravnborg
589ddd70cf9SJun Nakajimaconfig X86_GOLDFISH
590ddd70cf9SJun Nakajima	bool "Goldfish (Virtual Platform)"
591cb7b8023SBen Hutchings	depends on X86_EXTENDED_PLATFORM
592a7f7f624SMasahiro Yamada	help
593ddd70cf9SJun Nakajima	  Enable support for the Goldfish virtual platform used primarily
594ddd70cf9SJun Nakajima	  for Android development. Unless you are building for the Android
595ddd70cf9SJun Nakajima	  Goldfish emulator say N here.
596ddd70cf9SJun Nakajima
597c751e17bSThomas Gleixnerconfig X86_INTEL_CE
598c751e17bSThomas Gleixner	bool "CE4100 TV platform"
599c751e17bSThomas Gleixner	depends on PCI
600c751e17bSThomas Gleixner	depends on PCI_GODIRECT
6016084a6e2SJiang Liu	depends on X86_IO_APIC
602c751e17bSThomas Gleixner	depends on X86_32
603c751e17bSThomas Gleixner	depends on X86_EXTENDED_PLATFORM
60437bc9f50SDirk Brandewie	select X86_REBOOTFIXUPS
605da6b737bSSebastian Andrzej Siewior	select OF
606da6b737bSSebastian Andrzej Siewior	select OF_EARLY_FLATTREE
607a7f7f624SMasahiro Yamada	help
608c751e17bSThomas Gleixner	  Select for the Intel CE media processor (CE4100) SOC.
609c751e17bSThomas Gleixner	  This option compiles in support for the CE4100 SOC for settop
610c751e17bSThomas Gleixner	  boxes and media devices.
611c751e17bSThomas Gleixner
6124cb9b00fSDavid Cohenconfig X86_INTEL_MID
61343605ef1SAlan Cox	bool "Intel MID platform support"
61443605ef1SAlan Cox	depends on X86_EXTENDED_PLATFORM
615edc6bc78SDavid Cohen	depends on X86_PLATFORM_DEVICES
6161ea7c673SAlan Cox	depends on PCI
6173fda5bb4SAndy Shevchenko	depends on X86_64 || (PCI_GOANY && X86_32)
6181ea7c673SAlan Cox	depends on X86_IO_APIC
6194cb9b00fSDavid Cohen	select I2C
6207c9c3a1eSAlan Cox	select DW_APB_TIMER
62154b34aa0SMika Westerberg	select INTEL_SCU_PCI
622a7f7f624SMasahiro Yamada	help
6234cb9b00fSDavid Cohen	  Select to build a kernel capable of supporting Intel MID (Mobile
6244cb9b00fSDavid Cohen	  Internet Device) platform systems which do not have the PCI legacy
6254cb9b00fSDavid Cohen	  interfaces. If you are building for a PC class system say N here.
6261ea7c673SAlan Cox
6274cb9b00fSDavid Cohen	  Intel MID platforms are based on an Intel processor and chipset which
6284cb9b00fSDavid Cohen	  consume less power than most of the x86 derivatives.
62943605ef1SAlan Cox
6308bbc2a13SBryan O'Donoghueconfig X86_INTEL_QUARK
6318bbc2a13SBryan O'Donoghue	bool "Intel Quark platform support"
6328bbc2a13SBryan O'Donoghue	depends on X86_32
6338bbc2a13SBryan O'Donoghue	depends on X86_EXTENDED_PLATFORM
6348bbc2a13SBryan O'Donoghue	depends on X86_PLATFORM_DEVICES
6358bbc2a13SBryan O'Donoghue	depends on X86_TSC
6368bbc2a13SBryan O'Donoghue	depends on PCI
6378bbc2a13SBryan O'Donoghue	depends on PCI_GOANY
6388bbc2a13SBryan O'Donoghue	depends on X86_IO_APIC
6398bbc2a13SBryan O'Donoghue	select IOSF_MBI
6408bbc2a13SBryan O'Donoghue	select INTEL_IMR
6419ab6eb51SAndy Shevchenko	select COMMON_CLK
642a7f7f624SMasahiro Yamada	help
6438bbc2a13SBryan O'Donoghue	  Select to include support for Quark X1000 SoC.
6448bbc2a13SBryan O'Donoghue	  Say Y here if you have a Quark based system such as the Arduino
6458bbc2a13SBryan O'Donoghue	  compatible Intel Galileo.
6468bbc2a13SBryan O'Donoghue
6473d48aab1SMika Westerbergconfig X86_INTEL_LPSS
6483d48aab1SMika Westerberg	bool "Intel Low Power Subsystem Support"
6495962dd22SSinan Kaya	depends on X86 && ACPI && PCI
6503d48aab1SMika Westerberg	select COMMON_CLK
6510f531431SMathias Nyman	select PINCTRL
652eebb3e8dSAndy Shevchenko	select IOSF_MBI
653a7f7f624SMasahiro Yamada	help
6543d48aab1SMika Westerberg	  Select to build support for Intel Low Power Subsystem such as
6553d48aab1SMika Westerberg	  found on Intel Lynxpoint PCH. Selecting this option enables
6560f531431SMathias Nyman	  things like clock tree (common clock framework) and pincontrol
6570f531431SMathias Nyman	  which are needed by the LPSS peripheral drivers.
6583d48aab1SMika Westerberg
65992082a88SKen Xueconfig X86_AMD_PLATFORM_DEVICE
66092082a88SKen Xue	bool "AMD ACPI2Platform devices support"
66192082a88SKen Xue	depends on ACPI
66292082a88SKen Xue	select COMMON_CLK
66392082a88SKen Xue	select PINCTRL
664a7f7f624SMasahiro Yamada	help
66592082a88SKen Xue	  Select to interpret AMD specific ACPI device to platform device
66692082a88SKen Xue	  such as I2C, UART, GPIO found on AMD Carrizo and later chipsets.
66792082a88SKen Xue	  I2C and UART depend on COMMON_CLK to set clock. GPIO driver is
66892082a88SKen Xue	  implemented under PINCTRL subsystem.
66992082a88SKen Xue
670ced3ce76SDavid E. Boxconfig IOSF_MBI
671ced3ce76SDavid E. Box	tristate "Intel SoC IOSF Sideband support for SoC platforms"
672ced3ce76SDavid E. Box	depends on PCI
673a7f7f624SMasahiro Yamada	help
674ced3ce76SDavid E. Box	  This option enables sideband register access support for Intel SoC
675ced3ce76SDavid E. Box	  platforms. On these platforms the IOSF sideband is used in lieu of
676ced3ce76SDavid E. Box	  MSR's for some register accesses, mostly but not limited to thermal
677ced3ce76SDavid E. Box	  and power. Drivers may query the availability of this device to
678ced3ce76SDavid E. Box	  determine if they need the sideband in order to work on these
679ced3ce76SDavid E. Box	  platforms. The sideband is available on the following SoC products.
680ced3ce76SDavid E. Box	  This list is not meant to be exclusive.
681ced3ce76SDavid E. Box	   - BayTrail
682ced3ce76SDavid E. Box	   - Braswell
683ced3ce76SDavid E. Box	   - Quark
684ced3ce76SDavid E. Box
685ced3ce76SDavid E. Box	  You should say Y if you are running a kernel on one of these SoC's.
686ced3ce76SDavid E. Box
687ed2226bdSDavid E. Boxconfig IOSF_MBI_DEBUG
688ed2226bdSDavid E. Box	bool "Enable IOSF sideband access through debugfs"
689ed2226bdSDavid E. Box	depends on IOSF_MBI && DEBUG_FS
690a7f7f624SMasahiro Yamada	help
691ed2226bdSDavid E. Box	  Select this option to expose the IOSF sideband access registers (MCR,
692ed2226bdSDavid E. Box	  MDR, MCRX) through debugfs to write and read register information from
693ed2226bdSDavid E. Box	  different units on the SoC. This is most useful for obtaining device
694ed2226bdSDavid E. Box	  state information for debug and analysis. As this is a general access
695ed2226bdSDavid E. Box	  mechanism, users of this option would have specific knowledge of the
696ed2226bdSDavid E. Box	  device they want to access.
697ed2226bdSDavid E. Box
698ed2226bdSDavid E. Box	  If you don't require the option or are in doubt, say N.
699ed2226bdSDavid E. Box
700c5c606d9SRavikiran G Thirumalaiconfig X86_RDC321X
701c5c606d9SRavikiran G Thirumalai	bool "RDC R-321x SoC"
702506f1d07SSam Ravnborg	depends on X86_32
703c5c606d9SRavikiran G Thirumalai	depends on X86_EXTENDED_PLATFORM
704c5c606d9SRavikiran G Thirumalai	select M486
705c5c606d9SRavikiran G Thirumalai	select X86_REBOOTFIXUPS
706a7f7f624SMasahiro Yamada	help
707c5c606d9SRavikiran G Thirumalai	  This option is needed for RDC R-321x system-on-chip, also known
708c5c606d9SRavikiran G Thirumalai	  as R-8610-(G).
709c5c606d9SRavikiran G Thirumalai	  If you don't have one of these chips, you should say N here.
710c5c606d9SRavikiran G Thirumalai
711e0c7ae37SIngo Molnarconfig X86_32_NON_STANDARD
7129c398017SIngo Molnar	bool "Support non-standard 32-bit SMP architectures"
7139c398017SIngo Molnar	depends on X86_32 && SMP
714c5c606d9SRavikiran G Thirumalai	depends on X86_EXTENDED_PLATFORM
715a7f7f624SMasahiro Yamada	help
716b5660ba7SH. Peter Anvin	  This option compiles in the bigsmp and STA2X11 default
717b5660ba7SH. Peter Anvin	  subarchitectures.  It is intended for a generic binary
718b5660ba7SH. Peter Anvin	  kernel. If you select them all, kernel will probe it one by
719b5660ba7SH. Peter Anvin	  one and will fallback to default.
720d49c4288SYinghai Lu
721c5c606d9SRavikiran G Thirumalai# Alphabetically sorted list of Non standard 32 bit platforms
722d49c4288SYinghai Lu
723d949f36fSLinus Torvaldsconfig X86_SUPPORTS_MEMORY_FAILURE
7246fc108a0SJan Beulich	def_bool y
725d949f36fSLinus Torvalds	# MCE code calls memory_failure():
726d949f36fSLinus Torvalds	depends on X86_MCE
727d949f36fSLinus Torvalds	# On 32-bit this adds too big of NODES_SHIFT and we run out of page flags:
728d949f36fSLinus Torvalds	# On 32-bit SPARSEMEM adds too big of SECTIONS_WIDTH:
729d949f36fSLinus Torvalds	depends on X86_64 || !SPARSEMEM
730d949f36fSLinus Torvalds	select ARCH_SUPPORTS_MEMORY_FAILURE
731d949f36fSLinus Torvalds
73283125a3aSAlessandro Rubiniconfig STA2X11
73383125a3aSAlessandro Rubini	bool "STA2X11 Companion Chip Support"
73483125a3aSAlessandro Rubini	depends on X86_32_NON_STANDARD && PCI
73583125a3aSAlessandro Rubini	select SWIOTLB
73683125a3aSAlessandro Rubini	select MFD_STA2X11
7370145071bSLinus Walleij	select GPIOLIB
738a7f7f624SMasahiro Yamada	help
73983125a3aSAlessandro Rubini	  This adds support for boards based on the STA2X11 IO-Hub,
74083125a3aSAlessandro Rubini	  a.k.a. "ConneXt". The chip is used in place of the standard
74183125a3aSAlessandro Rubini	  PC chipset, so all "standard" peripherals are missing. If this
74283125a3aSAlessandro Rubini	  option is selected the kernel will still be able to boot on
74383125a3aSAlessandro Rubini	  standard PC machines.
74483125a3aSAlessandro Rubini
74582148d1dSShérabconfig X86_32_IRIS
74682148d1dSShérab	tristate "Eurobraille/Iris poweroff module"
74782148d1dSShérab	depends on X86_32
748a7f7f624SMasahiro Yamada	help
74982148d1dSShérab	  The Iris machines from EuroBraille do not have APM or ACPI support
75082148d1dSShérab	  to shut themselves down properly.  A special I/O sequence is
75182148d1dSShérab	  needed to do so, which is what this module does at
75282148d1dSShérab	  kernel shutdown.
75382148d1dSShérab
75482148d1dSShérab	  This is only for Iris machines from EuroBraille.
75582148d1dSShérab
75682148d1dSShérab	  If unused, say N.
75782148d1dSShérab
758ae1e9130SIngo Molnarconfig SCHED_OMIT_FRAME_POINTER
7593c2362e6SHarvey Harrison	def_bool y
7603c2362e6SHarvey Harrison	prompt "Single-depth WCHAN output"
761a87d0914SKen Chen	depends on X86
762a7f7f624SMasahiro Yamada	help
763506f1d07SSam Ravnborg	  Calculate simpler /proc/<PID>/wchan values. If this option
764506f1d07SSam Ravnborg	  is disabled then wchan values will recurse back to the
765506f1d07SSam Ravnborg	  caller function. This provides more accurate wchan values,
766506f1d07SSam Ravnborg	  at the expense of slightly more scheduling overhead.
767506f1d07SSam Ravnborg
768506f1d07SSam Ravnborg	  If in doubt, say "Y".
769506f1d07SSam Ravnborg
7706276a074SBorislav Petkovmenuconfig HYPERVISOR_GUEST
7716276a074SBorislav Petkov	bool "Linux guest support"
772a7f7f624SMasahiro Yamada	help
7736276a074SBorislav Petkov	  Say Y here to enable options for running Linux under various hyper-
7746276a074SBorislav Petkov	  visors. This option enables basic hypervisor detection and platform
7756276a074SBorislav Petkov	  setup.
776506f1d07SSam Ravnborg
7776276a074SBorislav Petkov	  If you say N, all options in this submenu will be skipped and
7786276a074SBorislav Petkov	  disabled, and Linux guest support won't be built in.
779506f1d07SSam Ravnborg
7806276a074SBorislav Petkovif HYPERVISOR_GUEST
781506f1d07SSam Ravnborg
782e61bd94aSEduardo Pereira Habkostconfig PARAVIRT
783e61bd94aSEduardo Pereira Habkost	bool "Enable paravirtualization code"
784a0e2bf7cSJuergen Gross	depends on HAVE_STATIC_CALL
785a7f7f624SMasahiro Yamada	help
786e61bd94aSEduardo Pereira Habkost	  This changes the kernel so it can modify itself when it is run
787e61bd94aSEduardo Pereira Habkost	  under a hypervisor, potentially improving performance significantly
788e61bd94aSEduardo Pereira Habkost	  over full virtualization.  However, when run without a hypervisor
789e61bd94aSEduardo Pereira Habkost	  the kernel is theoretically slower and slightly larger.
790e61bd94aSEduardo Pereira Habkost
791c00a280aSJuergen Grossconfig PARAVIRT_XXL
792c00a280aSJuergen Gross	bool
793c00a280aSJuergen Gross
7946276a074SBorislav Petkovconfig PARAVIRT_DEBUG
7956276a074SBorislav Petkov	bool "paravirt-ops debugging"
7966276a074SBorislav Petkov	depends on PARAVIRT && DEBUG_KERNEL
797a7f7f624SMasahiro Yamada	help
7986276a074SBorislav Petkov	  Enable to debug paravirt_ops internals.  Specifically, BUG if
7996276a074SBorislav Petkov	  a paravirt_op is missing when it is called.
8006276a074SBorislav Petkov
801b4ecc126SJeremy Fitzhardingeconfig PARAVIRT_SPINLOCKS
802b4ecc126SJeremy Fitzhardinge	bool "Paravirtualization layer for spinlocks"
8036ea30386SKees Cook	depends on PARAVIRT && SMP
804a7f7f624SMasahiro Yamada	help
805b4ecc126SJeremy Fitzhardinge	  Paravirtualized spinlocks allow a pvops backend to replace the
806b4ecc126SJeremy Fitzhardinge	  spinlock implementation with something virtualization-friendly
807b4ecc126SJeremy Fitzhardinge	  (for example, block the virtual CPU rather than spinning).
808b4ecc126SJeremy Fitzhardinge
8094c4e4f61SRaghavendra K T	  It has a minimal impact on native kernels and gives a nice performance
8104c4e4f61SRaghavendra K T	  benefit on paravirtualized KVM / Xen kernels.
811b4ecc126SJeremy Fitzhardinge
8124c4e4f61SRaghavendra K T	  If you are unsure how to answer this question, answer Y.
813b4ecc126SJeremy Fitzhardinge
814ecca2502SZhao Yakuiconfig X86_HV_CALLBACK_VECTOR
815ecca2502SZhao Yakui	def_bool n
816ecca2502SZhao Yakui
8176276a074SBorislav Petkovsource "arch/x86/xen/Kconfig"
8186276a074SBorislav Petkov
8196276a074SBorislav Petkovconfig KVM_GUEST
8206276a074SBorislav Petkov	bool "KVM Guest support (including kvmclock)"
8216276a074SBorislav Petkov	depends on PARAVIRT
8226276a074SBorislav Petkov	select PARAVIRT_CLOCK
823a1c4423bSMarcelo Tosatti	select ARCH_CPUIDLE_HALTPOLL
824b1d40575SVitaly Kuznetsov	select X86_HV_CALLBACK_VECTOR
8256276a074SBorislav Petkov	default y
826a7f7f624SMasahiro Yamada	help
8276276a074SBorislav Petkov	  This option enables various optimizations for running under the KVM
8286276a074SBorislav Petkov	  hypervisor. It includes a paravirtualized clock, so that instead
8296276a074SBorislav Petkov	  of relying on a PIT (or probably other) emulation by the
8306276a074SBorislav Petkov	  underlying device model, the host provides the guest with
8316276a074SBorislav Petkov	  timing infrastructure such as time of day, and system time
8326276a074SBorislav Petkov
833a1c4423bSMarcelo Tosatticonfig ARCH_CPUIDLE_HALTPOLL
834a1c4423bSMarcelo Tosatti	def_bool n
835a1c4423bSMarcelo Tosatti	prompt "Disable host haltpoll when loading haltpoll driver"
836a1c4423bSMarcelo Tosatti	help
837a1c4423bSMarcelo Tosatti	  If virtualized under KVM, disable host haltpoll.
838a1c4423bSMarcelo Tosatti
8397733607fSMaran Wilsonconfig PVH
8407733607fSMaran Wilson	bool "Support for running PVH guests"
841a7f7f624SMasahiro Yamada	help
8427733607fSMaran Wilson	  This option enables the PVH entry point for guest virtual machines
8437733607fSMaran Wilson	  as specified in the x86/HVM direct boot ABI.
8447733607fSMaran Wilson
8456276a074SBorislav Petkovconfig PARAVIRT_TIME_ACCOUNTING
8466276a074SBorislav Petkov	bool "Paravirtual steal time accounting"
8476276a074SBorislav Petkov	depends on PARAVIRT
848a7f7f624SMasahiro Yamada	help
8496276a074SBorislav Petkov	  Select this option to enable fine granularity task steal time
8506276a074SBorislav Petkov	  accounting. Time spent executing other tasks in parallel with
8516276a074SBorislav Petkov	  the current vCPU is discounted from the vCPU power. To account for
8526276a074SBorislav Petkov	  that, there can be a small performance impact.
8536276a074SBorislav Petkov
8546276a074SBorislav Petkov	  If in doubt, say N here.
8556276a074SBorislav Petkov
8567af192c9SGerd Hoffmannconfig PARAVIRT_CLOCK
8577af192c9SGerd Hoffmann	bool
8587af192c9SGerd Hoffmann
8594a362601SJan Kiszkaconfig JAILHOUSE_GUEST
8604a362601SJan Kiszka	bool "Jailhouse non-root cell support"
861abde587bSArnd Bergmann	depends on X86_64 && PCI
86287e65d05SJan Kiszka	select X86_PM_TIMER
863a7f7f624SMasahiro Yamada	help
8644a362601SJan Kiszka	  This option allows to run Linux as guest in a Jailhouse non-root
8654a362601SJan Kiszka	  cell. You can leave this option disabled if you only want to start
8664a362601SJan Kiszka	  Jailhouse and run Linux afterwards in the root cell.
8674a362601SJan Kiszka
868ec7972c9SZhao Yakuiconfig ACRN_GUEST
869ec7972c9SZhao Yakui	bool "ACRN Guest support"
870ec7972c9SZhao Yakui	depends on X86_64
871498ad393SZhao Yakui	select X86_HV_CALLBACK_VECTOR
872ec7972c9SZhao Yakui	help
873ec7972c9SZhao Yakui	  This option allows to run Linux as guest in the ACRN hypervisor. ACRN is
874ec7972c9SZhao Yakui	  a flexible, lightweight reference open-source hypervisor, built with
875ec7972c9SZhao Yakui	  real-time and safety-criticality in mind. It is built for embedded
876ec7972c9SZhao Yakui	  IOT with small footprint and real-time features. More details can be
877ec7972c9SZhao Yakui	  found in https://projectacrn.org/.
878ec7972c9SZhao Yakui
87959bd54a8SKuppuswamy Sathyanarayananconfig INTEL_TDX_GUEST
88059bd54a8SKuppuswamy Sathyanarayanan	bool "Intel TDX (Trust Domain Extensions) - Guest Support"
88159bd54a8SKuppuswamy Sathyanarayanan	depends on X86_64 && CPU_SUP_INTEL
88259bd54a8SKuppuswamy Sathyanarayanan	depends on X86_X2APIC
88375d090fdSKirill A. Shutemov	depends on EFI_STUB
88429f040d4SVishal Annapurve	depends on PARAVIRT
88541394e33SKirill A. Shutemov	select ARCH_HAS_CC_PLATFORM
886968b4931SKirill A. Shutemov	select X86_MEM_ENCRYPT
88777a512e3SSean Christopherson	select X86_MCE
88875d090fdSKirill A. Shutemov	select UNACCEPTED_MEMORY
88959bd54a8SKuppuswamy Sathyanarayanan	help
89059bd54a8SKuppuswamy Sathyanarayanan	  Support running as a guest under Intel TDX.  Without this support,
89159bd54a8SKuppuswamy Sathyanarayanan	  the guest kernel can not boot or run under TDX.
89259bd54a8SKuppuswamy Sathyanarayanan	  TDX includes memory encryption and integrity capabilities
89359bd54a8SKuppuswamy Sathyanarayanan	  which protect the confidentiality and integrity of guest
89459bd54a8SKuppuswamy Sathyanarayanan	  memory contents and CPU state. TDX guests are protected from
89559bd54a8SKuppuswamy Sathyanarayanan	  some attacks from the VMM.
89659bd54a8SKuppuswamy Sathyanarayanan
8976276a074SBorislav Petkovendif # HYPERVISOR_GUEST
89897349135SJeremy Fitzhardinge
899506f1d07SSam Ravnborgsource "arch/x86/Kconfig.cpu"
900506f1d07SSam Ravnborg
901506f1d07SSam Ravnborgconfig HPET_TIMER
9023c2362e6SHarvey Harrison	def_bool X86_64
903506f1d07SSam Ravnborg	prompt "HPET Timer Support" if X86_32
904a7f7f624SMasahiro Yamada	help
905506f1d07SSam Ravnborg	  Use the IA-PC HPET (High Precision Event Timer) to manage
906506f1d07SSam Ravnborg	  time in preference to the PIT and RTC, if a HPET is
907506f1d07SSam Ravnborg	  present.
908506f1d07SSam Ravnborg	  HPET is the next generation timer replacing legacy 8254s.
909506f1d07SSam Ravnborg	  The HPET provides a stable time base on SMP
910506f1d07SSam Ravnborg	  systems, unlike the TSC, but it is more expensive to access,
9114e7f9df2SMichael S. Tsirkin	  as it is off-chip.  The interface used is documented
9124e7f9df2SMichael S. Tsirkin	  in the HPET spec, revision 1.
913506f1d07SSam Ravnborg
914506f1d07SSam Ravnborg	  You can safely choose Y here.  However, HPET will only be
915506f1d07SSam Ravnborg	  activated if the platform and the BIOS support this feature.
916506f1d07SSam Ravnborg	  Otherwise the 8254 will be used for timing services.
917506f1d07SSam Ravnborg
918506f1d07SSam Ravnborg	  Choose N to continue using the legacy 8254 timer.
919506f1d07SSam Ravnborg
920506f1d07SSam Ravnborgconfig HPET_EMULATE_RTC
9213c2362e6SHarvey Harrison	def_bool y
9223228e1dcSAnand K Mistry	depends on HPET_TIMER && (RTC_DRV_CMOS=m || RTC_DRV_CMOS=y)
923506f1d07SSam Ravnborg
9246a108a14SDavid Rientjes# Mark as expert because too many people got it wrong.
925506f1d07SSam Ravnborg# The code disables itself when not needed.
9267ae9392cSThomas Petazzoniconfig DMI
9277ae9392cSThomas Petazzoni	default y
928cf074402SArd Biesheuvel	select DMI_SCAN_MACHINE_NON_EFI_FALLBACK
9296a108a14SDavid Rientjes	bool "Enable DMI scanning" if EXPERT
930a7f7f624SMasahiro Yamada	help
9317ae9392cSThomas Petazzoni	  Enabled scanning of DMI to identify machine quirks. Say Y
9327ae9392cSThomas Petazzoni	  here unless you have verified that your setup is not
9337ae9392cSThomas Petazzoni	  affected by entries in the DMI blacklist. Required by PNP
9347ae9392cSThomas Petazzoni	  BIOS code.
9357ae9392cSThomas Petazzoni
936506f1d07SSam Ravnborgconfig GART_IOMMU
93738901f1cSAndi Kleen	bool "Old AMD GART IOMMU support"
9382f9237d4SChristoph Hellwig	select DMA_OPS
939a4ce5a48SChristoph Hellwig	select IOMMU_HELPER
940506f1d07SSam Ravnborg	select SWIOTLB
94123ac4ae8SAndreas Herrmann	depends on X86_64 && PCI && AMD_NB
942a7f7f624SMasahiro Yamada	help
943ced3c42cSIngo Molnar	  Provides a driver for older AMD Athlon64/Opteron/Turion/Sempron
944ced3c42cSIngo Molnar	  GART based hardware IOMMUs.
945ced3c42cSIngo Molnar
946ced3c42cSIngo Molnar	  The GART supports full DMA access for devices with 32-bit access
947ced3c42cSIngo Molnar	  limitations, on systems with more than 3 GB. This is usually needed
948ced3c42cSIngo Molnar	  for USB, sound, many IDE/SATA chipsets and some other devices.
949ced3c42cSIngo Molnar
950ced3c42cSIngo Molnar	  Newer systems typically have a modern AMD IOMMU, supported via
951ced3c42cSIngo Molnar	  the CONFIG_AMD_IOMMU=y config option.
952ced3c42cSIngo Molnar
953ced3c42cSIngo Molnar	  In normal configurations this driver is only active when needed:
954ced3c42cSIngo Molnar	  there's more than 3 GB of memory and the system contains a
955ced3c42cSIngo Molnar	  32-bit limited device.
956ced3c42cSIngo Molnar
957ced3c42cSIngo Molnar	  If unsure, say Y.
958506f1d07SSam Ravnborg
9598b766b0fSMichal Suchanekconfig BOOT_VESA_SUPPORT
9608b766b0fSMichal Suchanek	bool
9618b766b0fSMichal Suchanek	help
9628b766b0fSMichal Suchanek	  If true, at least one selected framebuffer driver can take advantage
9638b766b0fSMichal Suchanek	  of VESA video modes set at an early boot stage via the vga= parameter.
9648b766b0fSMichal Suchanek
9651184dc2fSMike Travisconfig MAXSMP
966ddb0c5a6SSamuel Thibault	bool "Enable Maximum number of SMP Processors and NUMA Nodes"
9676ea30386SKees Cook	depends on X86_64 && SMP && DEBUG_KERNEL
96836f5101aSMike Travis	select CPUMASK_OFFSTACK
969a7f7f624SMasahiro Yamada	help
970ddb0c5a6SSamuel Thibault	  Enable maximum number of CPUS and NUMA Nodes for this architecture.
9711184dc2fSMike Travis	  If unsure, say N.
972506f1d07SSam Ravnborg
973aec6487eSIngo Molnar#
974aec6487eSIngo Molnar# The maximum number of CPUs supported:
975aec6487eSIngo Molnar#
976aec6487eSIngo Molnar# The main config value is NR_CPUS, which defaults to NR_CPUS_DEFAULT,
977aec6487eSIngo Molnar# and which can be configured interactively in the
978aec6487eSIngo Molnar# [NR_CPUS_RANGE_BEGIN ... NR_CPUS_RANGE_END] range.
979aec6487eSIngo Molnar#
980aec6487eSIngo Molnar# The ranges are different on 32-bit and 64-bit kernels, depending on
981aec6487eSIngo Molnar# hardware capabilities and scalability features of the kernel.
982aec6487eSIngo Molnar#
983aec6487eSIngo Molnar# ( If MAXSMP is enabled we just use the highest possible value and disable
984aec6487eSIngo Molnar#   interactive configuration. )
985aec6487eSIngo Molnar#
986a0d0bb4dSRandy Dunlap
987aec6487eSIngo Molnarconfig NR_CPUS_RANGE_BEGIN
988a0d0bb4dSRandy Dunlap	int
989aec6487eSIngo Molnar	default NR_CPUS_RANGE_END if MAXSMP
990a0d0bb4dSRandy Dunlap	default    1 if !SMP
991a0d0bb4dSRandy Dunlap	default    2
992a0d0bb4dSRandy Dunlap
993aec6487eSIngo Molnarconfig NR_CPUS_RANGE_END
994a0d0bb4dSRandy Dunlap	int
995a0d0bb4dSRandy Dunlap	depends on X86_32
996aec6487eSIngo Molnar	default   64 if  SMP &&  X86_BIGSMP
997aec6487eSIngo Molnar	default    8 if  SMP && !X86_BIGSMP
998a0d0bb4dSRandy Dunlap	default    1 if !SMP
999a0d0bb4dSRandy Dunlap
1000aec6487eSIngo Molnarconfig NR_CPUS_RANGE_END
1001a0d0bb4dSRandy Dunlap	int
1002a0d0bb4dSRandy Dunlap	depends on X86_64
10031edae1aeSScott Wood	default 8192 if  SMP && CPUMASK_OFFSTACK
10041edae1aeSScott Wood	default  512 if  SMP && !CPUMASK_OFFSTACK
1005a0d0bb4dSRandy Dunlap	default    1 if !SMP
1006aec6487eSIngo Molnar
1007aec6487eSIngo Molnarconfig NR_CPUS_DEFAULT
1008aec6487eSIngo Molnar	int
1009aec6487eSIngo Molnar	depends on X86_32
1010aec6487eSIngo Molnar	default   32 if  X86_BIGSMP
1011aec6487eSIngo Molnar	default    8 if  SMP
1012aec6487eSIngo Molnar	default    1 if !SMP
1013aec6487eSIngo Molnar
1014aec6487eSIngo Molnarconfig NR_CPUS_DEFAULT
1015aec6487eSIngo Molnar	int
1016aec6487eSIngo Molnar	depends on X86_64
1017a0d0bb4dSRandy Dunlap	default 8192 if  MAXSMP
1018a0d0bb4dSRandy Dunlap	default   64 if  SMP
1019aec6487eSIngo Molnar	default    1 if !SMP
1020a0d0bb4dSRandy Dunlap
1021506f1d07SSam Ravnborgconfig NR_CPUS
102236f5101aSMike Travis	int "Maximum number of CPUs" if SMP && !MAXSMP
1023aec6487eSIngo Molnar	range NR_CPUS_RANGE_BEGIN NR_CPUS_RANGE_END
1024aec6487eSIngo Molnar	default NR_CPUS_DEFAULT
1025a7f7f624SMasahiro Yamada	help
1026506f1d07SSam Ravnborg	  This allows you to specify the maximum number of CPUs which this
1027bb61ccc7SJosh Boyer	  kernel will support.  If CPUMASK_OFFSTACK is enabled, the maximum
1028cad14bb9SKirill A. Shutemov	  supported value is 8192, otherwise the maximum value is 512.  The
1029506f1d07SSam Ravnborg	  minimum value which makes sense is 2.
1030506f1d07SSam Ravnborg
1031aec6487eSIngo Molnar	  This is purely to save memory: each supported CPU adds about 8KB
1032aec6487eSIngo Molnar	  to the kernel image.
1033506f1d07SSam Ravnborg
103466558b73STim Chenconfig SCHED_CLUSTER
103566558b73STim Chen	bool "Cluster scheduler support"
103666558b73STim Chen	depends on SMP
103766558b73STim Chen	default y
103866558b73STim Chen	help
103966558b73STim Chen	  Cluster scheduler support improves the CPU scheduler's decision
104066558b73STim Chen	  making when dealing with machines that have clusters of CPUs.
104166558b73STim Chen	  Cluster usually means a couple of CPUs which are placed closely
104266558b73STim Chen	  by sharing mid-level caches, last-level cache tags or internal
104366558b73STim Chen	  busses.
104466558b73STim Chen
1045506f1d07SSam Ravnborgconfig SCHED_SMT
1046dbe73364SThomas Gleixner	def_bool y if SMP
1047506f1d07SSam Ravnborg
1048506f1d07SSam Ravnborgconfig SCHED_MC
10493c2362e6SHarvey Harrison	def_bool y
10503c2362e6SHarvey Harrison	prompt "Multi-core scheduler support"
1051c8e56d20SBorislav Petkov	depends on SMP
1052a7f7f624SMasahiro Yamada	help
1053506f1d07SSam Ravnborg	  Multi-core scheduler support improves the CPU scheduler's decision
1054506f1d07SSam Ravnborg	  making when dealing with multi-core CPU chips at a cost of slightly
1055506f1d07SSam Ravnborg	  increased overhead in some places. If unsure say N here.
1056506f1d07SSam Ravnborg
1057de966cf4STim Chenconfig SCHED_MC_PRIO
1058de966cf4STim Chen	bool "CPU core priorities scheduler support"
10590a21fc12SIngo Molnar	depends on SCHED_MC && CPU_SUP_INTEL
10600a21fc12SIngo Molnar	select X86_INTEL_PSTATE
10610a21fc12SIngo Molnar	select CPU_FREQ
1062de966cf4STim Chen	default y
1063a7f7f624SMasahiro Yamada	help
1064de966cf4STim Chen	  Intel Turbo Boost Max Technology 3.0 enabled CPUs have a
1065de966cf4STim Chen	  core ordering determined at manufacturing time, which allows
1066de966cf4STim Chen	  certain cores to reach higher turbo frequencies (when running
1067de966cf4STim Chen	  single threaded workloads) than others.
1068de966cf4STim Chen
1069de966cf4STim Chen	  Enabling this kernel feature teaches the scheduler about
1070de966cf4STim Chen	  the TBM3 (aka ITMT) priority order of the CPU cores and adjusts the
1071de966cf4STim Chen	  scheduler's CPU selection logic accordingly, so that higher
1072de966cf4STim Chen	  overall system performance can be achieved.
1073de966cf4STim Chen
1074de966cf4STim Chen	  This feature will have no effect on CPUs without this feature.
1075de966cf4STim Chen
1076de966cf4STim Chen	  If unsure say Y here.
10775e76b2abSTim Chen
107830b8b006SThomas Gleixnerconfig UP_LATE_INIT
107930b8b006SThomas Gleixner	def_bool y
1080ba360f88SThomas Gleixner	depends on !SMP && X86_LOCAL_APIC
108130b8b006SThomas Gleixner
1082506f1d07SSam Ravnborgconfig X86_UP_APIC
108350849eefSJan Beulich	bool "Local APIC support on uniprocessors" if !PCI_MSI
108450849eefSJan Beulich	default PCI_MSI
108538a1dfdaSBryan O'Donoghue	depends on X86_32 && !SMP && !X86_32_NON_STANDARD
1086a7f7f624SMasahiro Yamada	help
1087506f1d07SSam Ravnborg	  A local APIC (Advanced Programmable Interrupt Controller) is an
1088506f1d07SSam Ravnborg	  integrated interrupt controller in the CPU. If you have a single-CPU
1089506f1d07SSam Ravnborg	  system which has a processor with a local APIC, you can say Y here to
1090506f1d07SSam Ravnborg	  enable and use it. If you say Y here even though your machine doesn't
1091506f1d07SSam Ravnborg	  have a local APIC, then the kernel will still run with no slowdown at
1092506f1d07SSam Ravnborg	  all. The local APIC supports CPU-generated self-interrupts (timer,
1093506f1d07SSam Ravnborg	  performance counters), and the NMI watchdog which detects hard
1094506f1d07SSam Ravnborg	  lockups.
1095506f1d07SSam Ravnborg
1096506f1d07SSam Ravnborgconfig X86_UP_IOAPIC
1097506f1d07SSam Ravnborg	bool "IO-APIC support on uniprocessors"
1098506f1d07SSam Ravnborg	depends on X86_UP_APIC
1099a7f7f624SMasahiro Yamada	help
1100506f1d07SSam Ravnborg	  An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an
1101506f1d07SSam Ravnborg	  SMP-capable replacement for PC-style interrupt controllers. Most
1102506f1d07SSam Ravnborg	  SMP systems and many recent uniprocessor systems have one.
1103506f1d07SSam Ravnborg
1104506f1d07SSam Ravnborg	  If you have a single-CPU system with an IO-APIC, you can say Y here
1105506f1d07SSam Ravnborg	  to use it. If you say Y here even though your machine doesn't have
1106506f1d07SSam Ravnborg	  an IO-APIC, then the kernel will still run with no slowdown at all.
1107506f1d07SSam Ravnborg
1108506f1d07SSam Ravnborgconfig X86_LOCAL_APIC
11093c2362e6SHarvey Harrison	def_bool y
11100dbc6078SThomas Petazzoni	depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC || PCI_MSI
1111b5dc8e6cSJiang Liu	select IRQ_DOMAIN_HIERARCHY
1112506f1d07SSam Ravnborg
1113506f1d07SSam Ravnborgconfig X86_IO_APIC
1114b1da1e71SJan Beulich	def_bool y
1115b1da1e71SJan Beulich	depends on X86_LOCAL_APIC || X86_UP_IOAPIC
1116506f1d07SSam Ravnborg
111741b9eb26SStefan Assmannconfig X86_REROUTE_FOR_BROKEN_BOOT_IRQS
111841b9eb26SStefan Assmann	bool "Reroute for broken boot IRQs"
111941b9eb26SStefan Assmann	depends on X86_IO_APIC
1120a7f7f624SMasahiro Yamada	help
112141b9eb26SStefan Assmann	  This option enables a workaround that fixes a source of
112241b9eb26SStefan Assmann	  spurious interrupts. This is recommended when threaded
112341b9eb26SStefan Assmann	  interrupt handling is used on systems where the generation of
112441b9eb26SStefan Assmann	  superfluous "boot interrupts" cannot be disabled.
112541b9eb26SStefan Assmann
112641b9eb26SStefan Assmann	  Some chipsets generate a legacy INTx "boot IRQ" when the IRQ
112741b9eb26SStefan Assmann	  entry in the chipset's IO-APIC is masked (as, e.g. the RT
112841b9eb26SStefan Assmann	  kernel does during interrupt handling). On chipsets where this
112941b9eb26SStefan Assmann	  boot IRQ generation cannot be disabled, this workaround keeps
113041b9eb26SStefan Assmann	  the original IRQ line masked so that only the equivalent "boot
113141b9eb26SStefan Assmann	  IRQ" is delivered to the CPUs. The workaround also tells the
113241b9eb26SStefan Assmann	  kernel to set up the IRQ handler on the boot IRQ line. In this
113341b9eb26SStefan Assmann	  way only one interrupt is delivered to the kernel. Otherwise
113441b9eb26SStefan Assmann	  the spurious second interrupt may cause the kernel to bring
113541b9eb26SStefan Assmann	  down (vital) interrupt lines.
113641b9eb26SStefan Assmann
113741b9eb26SStefan Assmann	  Only affects "broken" chipsets. Interrupt sharing may be
113841b9eb26SStefan Assmann	  increased on these systems.
113941b9eb26SStefan Assmann
1140506f1d07SSam Ravnborgconfig X86_MCE
1141bab9bc65SAndi Kleen	bool "Machine Check / overheating reporting"
1142648ed940SChen, Gong	select GENERIC_ALLOCATOR
1143e57dbaf7SBorislav Petkov	default y
1144a7f7f624SMasahiro Yamada	help
1145bab9bc65SAndi Kleen	  Machine Check support allows the processor to notify the
1146bab9bc65SAndi Kleen	  kernel if it detects a problem (e.g. overheating, data corruption).
1147506f1d07SSam Ravnborg	  The action the kernel takes depends on the severity of the problem,
1148bab9bc65SAndi Kleen	  ranging from warning messages to halting the machine.
11494efc0670SAndi Kleen
11505de97c9fSTony Luckconfig X86_MCELOG_LEGACY
11515de97c9fSTony Luck	bool "Support for deprecated /dev/mcelog character device"
11525de97c9fSTony Luck	depends on X86_MCE
1153a7f7f624SMasahiro Yamada	help
11545de97c9fSTony Luck	  Enable support for /dev/mcelog which is needed by the old mcelog
11555de97c9fSTony Luck	  userspace logging daemon. Consider switching to the new generation
11565de97c9fSTony Luck	  rasdaemon solution.
11575de97c9fSTony Luck
1158506f1d07SSam Ravnborgconfig X86_MCE_INTEL
11593c2362e6SHarvey Harrison	def_bool y
11603c2362e6SHarvey Harrison	prompt "Intel MCE features"
1161c1ebf835SAndi Kleen	depends on X86_MCE && X86_LOCAL_APIC
1162a7f7f624SMasahiro Yamada	help
1163506f1d07SSam Ravnborg	  Additional support for intel specific MCE features such as
1164506f1d07SSam Ravnborg	  the thermal monitor.
1165506f1d07SSam Ravnborg
1166506f1d07SSam Ravnborgconfig X86_MCE_AMD
11673c2362e6SHarvey Harrison	def_bool y
11683c2362e6SHarvey Harrison	prompt "AMD MCE features"
1169f5382de9SYazen Ghannam	depends on X86_MCE && X86_LOCAL_APIC && AMD_NB
1170a7f7f624SMasahiro Yamada	help
1171506f1d07SSam Ravnborg	  Additional support for AMD specific MCE features such as
1172506f1d07SSam Ravnborg	  the DRAM Error Threshold.
1173506f1d07SSam Ravnborg
11744efc0670SAndi Kleenconfig X86_ANCIENT_MCE
11756fc108a0SJan Beulich	bool "Support for old Pentium 5 / WinChip machine checks"
1176c31d9633SAndi Kleen	depends on X86_32 && X86_MCE
1177a7f7f624SMasahiro Yamada	help
11784efc0670SAndi Kleen	  Include support for machine check handling on old Pentium 5 or WinChip
11795065a706SMasanari Iida	  systems. These typically need to be enabled explicitly on the command
11804efc0670SAndi Kleen	  line.
11814efc0670SAndi Kleen
1182b2762686SAndi Kleenconfig X86_MCE_THRESHOLD
1183b2762686SAndi Kleen	depends on X86_MCE_AMD || X86_MCE_INTEL
11846fc108a0SJan Beulich	def_bool y
1185b2762686SAndi Kleen
1186ea149b36SAndi Kleenconfig X86_MCE_INJECT
1187bc8e80d5SBorislav Petkov	depends on X86_MCE && X86_LOCAL_APIC && DEBUG_FS
1188ea149b36SAndi Kleen	tristate "Machine check injector support"
1189a7f7f624SMasahiro Yamada	help
1190ea149b36SAndi Kleen	  Provide support for injecting machine checks for testing purposes.
1191ea149b36SAndi Kleen	  If you don't know what a machine check is and you don't do kernel
1192ea149b36SAndi Kleen	  QA it is safe to say n.
1193ea149b36SAndi Kleen
119407dc900eSPeter Zijlstrasource "arch/x86/events/Kconfig"
1195e633c65aSKan Liang
11965aef51c3SAndy Lutomirskiconfig X86_LEGACY_VM86
11971e642812SIngo Molnar	bool "Legacy VM86 support"
1198506f1d07SSam Ravnborg	depends on X86_32
1199a7f7f624SMasahiro Yamada	help
12005aef51c3SAndy Lutomirski	  This option allows user programs to put the CPU into V8086
12015aef51c3SAndy Lutomirski	  mode, which is an 80286-era approximation of 16-bit real mode.
12025aef51c3SAndy Lutomirski
12035aef51c3SAndy Lutomirski	  Some very old versions of X and/or vbetool require this option
12045aef51c3SAndy Lutomirski	  for user mode setting.  Similarly, DOSEMU will use it if
12055aef51c3SAndy Lutomirski	  available to accelerate real mode DOS programs.  However, any
12065aef51c3SAndy Lutomirski	  recent version of DOSEMU, X, or vbetool should be fully
12075aef51c3SAndy Lutomirski	  functional even without kernel VM86 support, as they will all
12081e642812SIngo Molnar	  fall back to software emulation. Nevertheless, if you are using
12091e642812SIngo Molnar	  a 16-bit DOS program where 16-bit performance matters, vm86
12101e642812SIngo Molnar	  mode might be faster than emulation and you might want to
12111e642812SIngo Molnar	  enable this option.
12125aef51c3SAndy Lutomirski
12131e642812SIngo Molnar	  Note that any app that works on a 64-bit kernel is unlikely to
12141e642812SIngo Molnar	  need this option, as 64-bit kernels don't, and can't, support
12151e642812SIngo Molnar	  V8086 mode. This option is also unrelated to 16-bit protected
12161e642812SIngo Molnar	  mode and is not needed to run most 16-bit programs under Wine.
12175aef51c3SAndy Lutomirski
12181e642812SIngo Molnar	  Enabling this option increases the complexity of the kernel
12191e642812SIngo Molnar	  and slows down exception handling a tiny bit.
12205aef51c3SAndy Lutomirski
12211e642812SIngo Molnar	  If unsure, say N here.
12225aef51c3SAndy Lutomirski
12235aef51c3SAndy Lutomirskiconfig VM86
12245aef51c3SAndy Lutomirski	bool
12255aef51c3SAndy Lutomirski	default X86_LEGACY_VM86
122634273f41SH. Peter Anvin
122734273f41SH. Peter Anvinconfig X86_16BIT
122834273f41SH. Peter Anvin	bool "Enable support for 16-bit segments" if EXPERT
122934273f41SH. Peter Anvin	default y
1230a5b9e5a2SAndy Lutomirski	depends on MODIFY_LDT_SYSCALL
1231a7f7f624SMasahiro Yamada	help
123234273f41SH. Peter Anvin	  This option is required by programs like Wine to run 16-bit
123334273f41SH. Peter Anvin	  protected mode legacy code on x86 processors.  Disabling
123434273f41SH. Peter Anvin	  this option saves about 300 bytes on i386, or around 6K text
123534273f41SH. Peter Anvin	  plus 16K runtime memory on x86-64,
123634273f41SH. Peter Anvin
123734273f41SH. Peter Anvinconfig X86_ESPFIX32
123834273f41SH. Peter Anvin	def_bool y
123934273f41SH. Peter Anvin	depends on X86_16BIT && X86_32
1240506f1d07SSam Ravnborg
1241197725deSH. Peter Anvinconfig X86_ESPFIX64
1242197725deSH. Peter Anvin	def_bool y
124334273f41SH. Peter Anvin	depends on X86_16BIT && X86_64
1244506f1d07SSam Ravnborg
12451ad83c85SAndy Lutomirskiconfig X86_VSYSCALL_EMULATION
12461ad83c85SAndy Lutomirski	bool "Enable vsyscall emulation" if EXPERT
12471ad83c85SAndy Lutomirski	default y
12481ad83c85SAndy Lutomirski	depends on X86_64
1249a7f7f624SMasahiro Yamada	help
12501ad83c85SAndy Lutomirski	  This enables emulation of the legacy vsyscall page.  Disabling
12511ad83c85SAndy Lutomirski	  it is roughly equivalent to booting with vsyscall=none, except
12521ad83c85SAndy Lutomirski	  that it will also disable the helpful warning if a program
12531ad83c85SAndy Lutomirski	  tries to use a vsyscall.  With this option set to N, offending
12541ad83c85SAndy Lutomirski	  programs will just segfault, citing addresses of the form
12551ad83c85SAndy Lutomirski	  0xffffffffff600?00.
12561ad83c85SAndy Lutomirski
12571ad83c85SAndy Lutomirski	  This option is required by many programs built before 2013, and
12581ad83c85SAndy Lutomirski	  care should be used even with newer programs if set to N.
12591ad83c85SAndy Lutomirski
12601ad83c85SAndy Lutomirski	  Disabling this option saves about 7K of kernel size and
12611ad83c85SAndy Lutomirski	  possibly 4K of additional runtime pagetable memory.
12621ad83c85SAndy Lutomirski
1263111e7b15SThomas Gleixnerconfig X86_IOPL_IOPERM
1264111e7b15SThomas Gleixner	bool "IOPERM and IOPL Emulation"
1265a24ca997SThomas Gleixner	default y
1266a7f7f624SMasahiro Yamada	help
1267111e7b15SThomas Gleixner	  This enables the ioperm() and iopl() syscalls which are necessary
1268111e7b15SThomas Gleixner	  for legacy applications.
1269111e7b15SThomas Gleixner
1270c8137aceSThomas Gleixner	  Legacy IOPL support is an overbroad mechanism which allows user
1271c8137aceSThomas Gleixner	  space aside of accessing all 65536 I/O ports also to disable
1272c8137aceSThomas Gleixner	  interrupts. To gain this access the caller needs CAP_SYS_RAWIO
1273c8137aceSThomas Gleixner	  capabilities and permission from potentially active security
1274c8137aceSThomas Gleixner	  modules.
1275c8137aceSThomas Gleixner
1276c8137aceSThomas Gleixner	  The emulation restricts the functionality of the syscall to
1277c8137aceSThomas Gleixner	  only allowing the full range I/O port access, but prevents the
1278a24ca997SThomas Gleixner	  ability to disable interrupts from user space which would be
1279a24ca997SThomas Gleixner	  granted if the hardware IOPL mechanism would be used.
1280c8137aceSThomas Gleixner
1281506f1d07SSam Ravnborgconfig TOSHIBA
1282506f1d07SSam Ravnborg	tristate "Toshiba Laptop support"
1283506f1d07SSam Ravnborg	depends on X86_32
1284a7f7f624SMasahiro Yamada	help
1285506f1d07SSam Ravnborg	  This adds a driver to safely access the System Management Mode of
1286506f1d07SSam Ravnborg	  the CPU on Toshiba portables with a genuine Toshiba BIOS. It does
1287506f1d07SSam Ravnborg	  not work on models with a Phoenix BIOS. The System Management Mode
1288506f1d07SSam Ravnborg	  is used to set the BIOS and power saving options on Toshiba portables.
1289506f1d07SSam Ravnborg
1290506f1d07SSam Ravnborg	  For information on utilities to make use of this driver see the
1291506f1d07SSam Ravnborg	  Toshiba Linux utilities web site at:
1292506f1d07SSam Ravnborg	  <http://www.buzzard.org.uk/toshiba/>.
1293506f1d07SSam Ravnborg
1294506f1d07SSam Ravnborg	  Say Y if you intend to run this kernel on a Toshiba portable.
1295506f1d07SSam Ravnborg	  Say N otherwise.
1296506f1d07SSam Ravnborg
1297506f1d07SSam Ravnborgconfig X86_REBOOTFIXUPS
12989ba16087SJan Beulich	bool "Enable X86 board specific fixups for reboot"
12999ba16087SJan Beulich	depends on X86_32
1300a7f7f624SMasahiro Yamada	help
1301506f1d07SSam Ravnborg	  This enables chipset and/or board specific fixups to be done
1302506f1d07SSam Ravnborg	  in order to get reboot to work correctly. This is only needed on
1303506f1d07SSam Ravnborg	  some combinations of hardware and BIOS. The symptom, for which
1304506f1d07SSam Ravnborg	  this config is intended, is when reboot ends with a stalled/hung
1305506f1d07SSam Ravnborg	  system.
1306506f1d07SSam Ravnborg
1307506f1d07SSam Ravnborg	  Currently, the only fixup is for the Geode machines using
13085e3a77e9SFlorian Fainelli	  CS5530A and CS5536 chipsets and the RDC R-321x SoC.
1309506f1d07SSam Ravnborg
1310506f1d07SSam Ravnborg	  Say Y if you want to enable the fixup. Currently, it's safe to
1311506f1d07SSam Ravnborg	  enable this option even if you don't need it.
1312506f1d07SSam Ravnborg	  Say N otherwise.
1313506f1d07SSam Ravnborg
1314506f1d07SSam Ravnborgconfig MICROCODE
1315e6bcfdd7SThomas Gleixner	def_bool y
131680030e3dSBorislav Petkov	depends on CPU_SUP_AMD || CPU_SUP_INTEL
1317bef83014SBorislav Petkov (AMD)	select CRYPTO_LIB_SHA256 if CPU_SUP_AMD
131880cc9f10SPeter Oruba
1319d4c860bbSThomas Gleixnerconfig MICROCODE_INITRD32
1320d4c860bbSThomas Gleixner	def_bool y
1321d4c860bbSThomas Gleixner	depends on MICROCODE && X86_32 && BLK_DEV_INITRD
1322d4c860bbSThomas Gleixner
1323a77a94f8SBorislav Petkovconfig MICROCODE_LATE_LOADING
1324a77a94f8SBorislav Petkov	bool "Late microcode loading (DANGEROUS)"
1325c02f48e0SBorislav Petkov	default n
13267412a65dSThomas Gleixner	depends on MICROCODE && SMP
1327a7f7f624SMasahiro Yamada	help
1328a77a94f8SBorislav Petkov	  Loading microcode late, when the system is up and executing instructions
1329a77a94f8SBorislav Petkov	  is a tricky business and should be avoided if possible. Just the sequence
1330a77a94f8SBorislav Petkov	  of synchronizing all cores and SMT threads is one fragile dance which does
1331a77a94f8SBorislav Petkov	  not guarantee that cores might not softlock after the loading. Therefore,
1332fba6e6fcSThomas Gleixner	  use this at your own risk. Late loading taints the kernel unless the
1333fba6e6fcSThomas Gleixner	  microcode header indicates that it is safe for late loading via the
1334fba6e6fcSThomas Gleixner	  minimal revision check. This minimal revision check can be enforced on
1335fba6e6fcSThomas Gleixner	  the kernel command line with "microcode.minrev=Y".
1336fba6e6fcSThomas Gleixner
1337fba6e6fcSThomas Gleixnerconfig MICROCODE_LATE_FORCE_MINREV
1338fba6e6fcSThomas Gleixner	bool "Enforce late microcode loading minimal revision check"
1339fba6e6fcSThomas Gleixner	default n
1340fba6e6fcSThomas Gleixner	depends on MICROCODE_LATE_LOADING
1341fba6e6fcSThomas Gleixner	help
1342fba6e6fcSThomas Gleixner	  To prevent that users load microcode late which modifies already
1343fba6e6fcSThomas Gleixner	  in use features, newer microcode patches have a minimum revision field
1344fba6e6fcSThomas Gleixner	  in the microcode header, which tells the kernel which minimum
1345fba6e6fcSThomas Gleixner	  revision must be active in the CPU to safely load that new microcode
1346fba6e6fcSThomas Gleixner	  late into the running system. If disabled the check will not
1347fba6e6fcSThomas Gleixner	  be enforced but the kernel will be tainted when the minimal
1348fba6e6fcSThomas Gleixner	  revision check fails.
1349fba6e6fcSThomas Gleixner
1350fba6e6fcSThomas Gleixner	  This minimal revision check can also be controlled via the
1351fba6e6fcSThomas Gleixner	  "microcode.minrev" parameter on the kernel command line.
1352fba6e6fcSThomas Gleixner
1353fba6e6fcSThomas Gleixner	  If unsure say Y.
1354506f1d07SSam Ravnborg
1355506f1d07SSam Ravnborgconfig X86_MSR
1356506f1d07SSam Ravnborg	tristate "/dev/cpu/*/msr - Model-specific register support"
1357a7f7f624SMasahiro Yamada	help
1358506f1d07SSam Ravnborg	  This device gives privileged processes access to the x86
1359506f1d07SSam Ravnborg	  Model-Specific Registers (MSRs).  It is a character device with
1360506f1d07SSam Ravnborg	  major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr.
1361506f1d07SSam Ravnborg	  MSR accesses are directed to a specific CPU on multi-processor
1362506f1d07SSam Ravnborg	  systems.
1363506f1d07SSam Ravnborg
1364506f1d07SSam Ravnborgconfig X86_CPUID
1365506f1d07SSam Ravnborg	tristate "/dev/cpu/*/cpuid - CPU information support"
1366a7f7f624SMasahiro Yamada	help
1367506f1d07SSam Ravnborg	  This device gives processes access to the x86 CPUID instruction to
1368506f1d07SSam Ravnborg	  be executed on a specific processor.  It is a character device
1369506f1d07SSam Ravnborg	  with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to
1370506f1d07SSam Ravnborg	  /dev/cpu/31/cpuid.
1371506f1d07SSam Ravnborg
1372506f1d07SSam Ravnborgchoice
1373506f1d07SSam Ravnborg	prompt "High Memory Support"
13746fc108a0SJan Beulich	default HIGHMEM4G
1375506f1d07SSam Ravnborg	depends on X86_32
1376506f1d07SSam Ravnborg
1377506f1d07SSam Ravnborgconfig NOHIGHMEM
1378506f1d07SSam Ravnborg	bool "off"
1379a7f7f624SMasahiro Yamada	help
1380506f1d07SSam Ravnborg	  Linux can use up to 64 Gigabytes of physical memory on x86 systems.
1381506f1d07SSam Ravnborg	  However, the address space of 32-bit x86 processors is only 4
1382506f1d07SSam Ravnborg	  Gigabytes large. That means that, if you have a large amount of
1383506f1d07SSam Ravnborg	  physical memory, not all of it can be "permanently mapped" by the
1384506f1d07SSam Ravnborg	  kernel. The physical memory that's not permanently mapped is called
1385506f1d07SSam Ravnborg	  "high memory".
1386506f1d07SSam Ravnborg
1387506f1d07SSam Ravnborg	  If you are compiling a kernel which will never run on a machine with
1388506f1d07SSam Ravnborg	  more than 1 Gigabyte total physical RAM, answer "off" here (default
1389506f1d07SSam Ravnborg	  choice and suitable for most users). This will result in a "3GB/1GB"
1390506f1d07SSam Ravnborg	  split: 3GB are mapped so that each process sees a 3GB virtual memory
1391506f1d07SSam Ravnborg	  space and the remaining part of the 4GB virtual memory space is used
1392506f1d07SSam Ravnborg	  by the kernel to permanently map as much physical memory as
1393506f1d07SSam Ravnborg	  possible.
1394506f1d07SSam Ravnborg
1395506f1d07SSam Ravnborg	  If the machine has between 1 and 4 Gigabytes physical RAM, then
1396506f1d07SSam Ravnborg	  answer "4GB" here.
1397506f1d07SSam Ravnborg
1398506f1d07SSam Ravnborg	  If more than 4 Gigabytes is used then answer "64GB" here. This
1399506f1d07SSam Ravnborg	  selection turns Intel PAE (Physical Address Extension) mode on.
1400506f1d07SSam Ravnborg	  PAE implements 3-level paging on IA32 processors. PAE is fully
1401506f1d07SSam Ravnborg	  supported by Linux, PAE mode is implemented on all recent Intel
1402506f1d07SSam Ravnborg	  processors (Pentium Pro and better). NOTE: If you say "64GB" here,
1403506f1d07SSam Ravnborg	  then the kernel will not boot on CPUs that don't support PAE!
1404506f1d07SSam Ravnborg
1405506f1d07SSam Ravnborg	  The actual amount of total physical memory will either be
1406506f1d07SSam Ravnborg	  auto detected or can be forced by using a kernel command line option
1407506f1d07SSam Ravnborg	  such as "mem=256M". (Try "man bootparam" or see the documentation of
1408506f1d07SSam Ravnborg	  your boot loader (lilo or loadlin) about how to pass options to the
1409506f1d07SSam Ravnborg	  kernel at boot time.)
1410506f1d07SSam Ravnborg
1411506f1d07SSam Ravnborg	  If unsure, say "off".
1412506f1d07SSam Ravnborg
1413506f1d07SSam Ravnborgconfig HIGHMEM4G
1414506f1d07SSam Ravnborg	bool "4GB"
1415a7f7f624SMasahiro Yamada	help
1416506f1d07SSam Ravnborg	  Select this if you have a 32-bit processor and between 1 and 4
1417506f1d07SSam Ravnborg	  gigabytes of physical RAM.
1418506f1d07SSam Ravnborg
1419506f1d07SSam Ravnborgconfig HIGHMEM64G
1420506f1d07SSam Ravnborg	bool "64GB"
1421225bac2dSLukas Bulwahn	depends on !M486SX && !M486 && !M586 && !M586TSC && !M586MMX && !MGEODE_LX && !MGEODEGX1 && !MCYRIXIII && !MELAN && !MWINCHIPC6 && !MWINCHIP3D && !MK6
1422506f1d07SSam Ravnborg	select X86_PAE
1423a7f7f624SMasahiro Yamada	help
1424506f1d07SSam Ravnborg	  Select this if you have a 32-bit processor and more than 4
1425506f1d07SSam Ravnborg	  gigabytes of physical RAM.
1426506f1d07SSam Ravnborg
1427506f1d07SSam Ravnborgendchoice
1428506f1d07SSam Ravnborg
1429506f1d07SSam Ravnborgchoice
14306a108a14SDavid Rientjes	prompt "Memory split" if EXPERT
1431506f1d07SSam Ravnborg	default VMSPLIT_3G
1432506f1d07SSam Ravnborg	depends on X86_32
1433a7f7f624SMasahiro Yamada	help
1434506f1d07SSam Ravnborg	  Select the desired split between kernel and user memory.
1435506f1d07SSam Ravnborg
1436506f1d07SSam Ravnborg	  If the address range available to the kernel is less than the
1437506f1d07SSam Ravnborg	  physical memory installed, the remaining memory will be available
1438506f1d07SSam Ravnborg	  as "high memory". Accessing high memory is a little more costly
1439506f1d07SSam Ravnborg	  than low memory, as it needs to be mapped into the kernel first.
1440506f1d07SSam Ravnborg	  Note that increasing the kernel address space limits the range
1441506f1d07SSam Ravnborg	  available to user programs, making the address space there
1442506f1d07SSam Ravnborg	  tighter.  Selecting anything other than the default 3G/1G split
1443506f1d07SSam Ravnborg	  will also likely make your kernel incompatible with binary-only
1444506f1d07SSam Ravnborg	  kernel modules.
1445506f1d07SSam Ravnborg
1446506f1d07SSam Ravnborg	  If you are not absolutely sure what you are doing, leave this
1447506f1d07SSam Ravnborg	  option alone!
1448506f1d07SSam Ravnborg
1449506f1d07SSam Ravnborg	config VMSPLIT_3G
1450506f1d07SSam Ravnborg		bool "3G/1G user/kernel split"
1451506f1d07SSam Ravnborg	config VMSPLIT_3G_OPT
1452506f1d07SSam Ravnborg		depends on !X86_PAE
1453506f1d07SSam Ravnborg		bool "3G/1G user/kernel split (for full 1G low memory)"
1454506f1d07SSam Ravnborg	config VMSPLIT_2G
1455506f1d07SSam Ravnborg		bool "2G/2G user/kernel split"
1456506f1d07SSam Ravnborg	config VMSPLIT_2G_OPT
1457506f1d07SSam Ravnborg		depends on !X86_PAE
1458506f1d07SSam Ravnborg		bool "2G/2G user/kernel split (for full 2G low memory)"
1459506f1d07SSam Ravnborg	config VMSPLIT_1G
1460506f1d07SSam Ravnborg		bool "1G/3G user/kernel split"
1461506f1d07SSam Ravnborgendchoice
1462506f1d07SSam Ravnborg
1463506f1d07SSam Ravnborgconfig PAGE_OFFSET
1464506f1d07SSam Ravnborg	hex
1465506f1d07SSam Ravnborg	default 0xB0000000 if VMSPLIT_3G_OPT
1466506f1d07SSam Ravnborg	default 0x80000000 if VMSPLIT_2G
1467506f1d07SSam Ravnborg	default 0x78000000 if VMSPLIT_2G_OPT
1468506f1d07SSam Ravnborg	default 0x40000000 if VMSPLIT_1G
1469506f1d07SSam Ravnborg	default 0xC0000000
1470506f1d07SSam Ravnborg	depends on X86_32
1471506f1d07SSam Ravnborg
1472506f1d07SSam Ravnborgconfig HIGHMEM
14733c2362e6SHarvey Harrison	def_bool y
1474506f1d07SSam Ravnborg	depends on X86_32 && (HIGHMEM64G || HIGHMEM4G)
1475506f1d07SSam Ravnborg
1476506f1d07SSam Ravnborgconfig X86_PAE
14779ba16087SJan Beulich	bool "PAE (Physical Address Extension) Support"
1478506f1d07SSam Ravnborg	depends on X86_32 && !HIGHMEM4G
1479d4a451d5SChristoph Hellwig	select PHYS_ADDR_T_64BIT
14809d99c712SChristian Melki	select SWIOTLB
1481a7f7f624SMasahiro Yamada	help
1482506f1d07SSam Ravnborg	  PAE is required for NX support, and furthermore enables
1483506f1d07SSam Ravnborg	  larger swapspace support for non-overcommit purposes. It
1484506f1d07SSam Ravnborg	  has the cost of more pagetable lookup overhead, and also
1485506f1d07SSam Ravnborg	  consumes more pagetable space per process.
1486506f1d07SSam Ravnborg
148777ef56e4SKirill A. Shutemovconfig X86_5LEVEL
148877ef56e4SKirill A. Shutemov	bool "Enable 5-level page tables support"
148918ec1eafSKirill A. Shutemov	default y
1490eedb92abSKirill A. Shutemov	select DYNAMIC_MEMORY_LAYOUT
1491162434e7SKirill A. Shutemov	select SPARSEMEM_VMEMMAP
149277ef56e4SKirill A. Shutemov	depends on X86_64
1493a7f7f624SMasahiro Yamada	help
149477ef56e4SKirill A. Shutemov	  5-level paging enables access to larger address space:
149577ef56e4SKirill A. Shutemov	  up to 128 PiB of virtual address space and 4 PiB of
149677ef56e4SKirill A. Shutemov	  physical address space.
149777ef56e4SKirill A. Shutemov
149877ef56e4SKirill A. Shutemov	  It will be supported by future Intel CPUs.
149977ef56e4SKirill A. Shutemov
15006657fca0SKirill A. Shutemov	  A kernel with the option enabled can be booted on machines that
15016657fca0SKirill A. Shutemov	  support 4- or 5-level paging.
150277ef56e4SKirill A. Shutemov
1503ff61f079SJonathan Corbet	  See Documentation/arch/x86/x86_64/5level-paging.rst for more
150477ef56e4SKirill A. Shutemov	  information.
150577ef56e4SKirill A. Shutemov
150677ef56e4SKirill A. Shutemov	  Say N if unsure.
150777ef56e4SKirill A. Shutemov
150810971ab2SIngo Molnarconfig X86_DIRECT_GBPAGES
1509e5008abeSLuis R. Rodriguez	def_bool y
15102e1da13fSVlastimil Babka	depends on X86_64
1511a7f7f624SMasahiro Yamada	help
151210971ab2SIngo Molnar	  Certain kernel features effectively disable kernel
151310971ab2SIngo Molnar	  linear 1 GB mappings (even if the CPU otherwise
151410971ab2SIngo Molnar	  supports them), so don't confuse the user by printing
151510971ab2SIngo Molnar	  that we have them enabled.
15169e899816SNick Piggin
15175c280cf6SThomas Gleixnerconfig X86_CPA_STATISTICS
15185c280cf6SThomas Gleixner	bool "Enable statistic for Change Page Attribute"
15195c280cf6SThomas Gleixner	depends on DEBUG_FS
1520a7f7f624SMasahiro Yamada	help
1521b75baaf3SIngo Molnar	  Expose statistics about the Change Page Attribute mechanism, which
1522a943245aSColin Ian King	  helps to determine the effectiveness of preserving large and huge
15235c280cf6SThomas Gleixner	  page mappings when mapping protections are changed.
15245c280cf6SThomas Gleixner
152520f07a04SKirill A. Shutemovconfig X86_MEM_ENCRYPT
152620f07a04SKirill A. Shutemov	select ARCH_HAS_FORCE_DMA_UNENCRYPTED
152720f07a04SKirill A. Shutemov	select DYNAMIC_PHYSICAL_MASK
152820f07a04SKirill A. Shutemov	def_bool n
152920f07a04SKirill A. Shutemov
15307744ccdbSTom Lendackyconfig AMD_MEM_ENCRYPT
15317744ccdbSTom Lendacky	bool "AMD Secure Memory Encryption (SME) support"
15327744ccdbSTom Lendacky	depends on X86_64 && CPU_SUP_AMD
15336c321179STom Lendacky	depends on EFI_STUB
153482fef0adSDavid Rientjes	select DMA_COHERENT_POOL
1535ce9084baSArd Biesheuvel	select ARCH_USE_MEMREMAP_PROT
1536597cfe48SJoerg Roedel	select INSTRUCTION_DECODER
1537aa5a4611STom Lendacky	select ARCH_HAS_CC_PLATFORM
153820f07a04SKirill A. Shutemov	select X86_MEM_ENCRYPT
15396c321179STom Lendacky	select UNACCEPTED_MEMORY
1540a7f7f624SMasahiro Yamada	help
15417744ccdbSTom Lendacky	  Say yes to enable support for the encryption of system memory.
15427744ccdbSTom Lendacky	  This requires an AMD processor that supports Secure Memory
15437744ccdbSTom Lendacky	  Encryption (SME).
15447744ccdbSTom Lendacky
1545506f1d07SSam Ravnborg# Common NUMA Features
1546506f1d07SSam Ravnborgconfig NUMA
1547e133f6eaSRandy Dunlap	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
15517ecd19cfSKefeng Wang	select USE_PERCPU_NUMA_NODE_ID
1552a7f7f624SMasahiro Yamada	help
1553e133f6eaSRandy Dunlap	  Enable NUMA (Non-Uniform Memory Access) support.
1554fd51b2d7SKOSAKI Motohiro
1555506f1d07SSam Ravnborg	  The kernel will try to allocate memory used by a CPU on the
1556506f1d07SSam Ravnborg	  local memory controller of the CPU and add some more
1557506f1d07SSam Ravnborg	  NUMA awareness to the kernel.
1558506f1d07SSam Ravnborg
1559c280ea5eSIngo Molnar	  For 64-bit this is recommended if the system is Intel Core i7
1560fd51b2d7SKOSAKI Motohiro	  (or later), AMD Opteron, or EM64T NUMA.
1561fd51b2d7SKOSAKI Motohiro
1562b5660ba7SH. Peter Anvin	  For 32-bit this is only needed if you boot a 32-bit
15637cf6c945SDavid Rientjes	  kernel on a 64-bit NUMA platform.
1564fd51b2d7SKOSAKI Motohiro
1565fd51b2d7SKOSAKI Motohiro	  Otherwise, you should say N.
1566506f1d07SSam Ravnborg
1567eec1d4faSHans Rosenfeldconfig AMD_NUMA
15683c2362e6SHarvey Harrison	def_bool y
15693c2362e6SHarvey Harrison	prompt "Old style AMD Opteron NUMA detection"
15705da0ef9aSTejun Heo	depends on X86_64 && NUMA && PCI
1571a7f7f624SMasahiro Yamada	help
1572eec1d4faSHans Rosenfeld	  Enable AMD NUMA node topology detection.  You should say Y here if
1573eec1d4faSHans Rosenfeld	  you have a multi processor AMD system. This uses an old method to
1574eec1d4faSHans Rosenfeld	  read the NUMA configuration directly from the builtin Northbridge
1575eec1d4faSHans Rosenfeld	  of Opteron. It is recommended to use X86_64_ACPI_NUMA instead,
1576eec1d4faSHans Rosenfeld	  which also takes priority if both are compiled in.
1577506f1d07SSam Ravnborg
1578506f1d07SSam Ravnborgconfig X86_64_ACPI_NUMA
15793c2362e6SHarvey Harrison	def_bool y
15803c2362e6SHarvey Harrison	prompt "ACPI NUMA detection"
1581506f1d07SSam Ravnborg	depends on X86_64 && NUMA && ACPI && PCI
1582506f1d07SSam Ravnborg	select ACPI_NUMA
1583a7f7f624SMasahiro Yamada	help
1584506f1d07SSam Ravnborg	  Enable ACPI SRAT based node topology detection.
1585506f1d07SSam Ravnborg
1586506f1d07SSam Ravnborgconfig NUMA_EMU
1587506f1d07SSam Ravnborg	bool "NUMA emulation"
15881b7e03efSTejun Heo	depends on NUMA
1589a7f7f624SMasahiro Yamada	help
1590506f1d07SSam Ravnborg	  Enable NUMA emulation. A flat machine will be split
1591506f1d07SSam Ravnborg	  into virtual nodes when booted with "numa=fake=N", where N is the
1592506f1d07SSam Ravnborg	  number of nodes. This is only useful for debugging.
1593506f1d07SSam Ravnborg
1594506f1d07SSam Ravnborgconfig NODES_SHIFT
1595d25e26b6SLinus Torvalds	int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP
159651591e31SDavid Rientjes	range 1 10
159751591e31SDavid Rientjes	default "10" if MAXSMP
1598506f1d07SSam Ravnborg	default "6" if X86_64
1599506f1d07SSam Ravnborg	default "3"
1600a9ee6cf5SMike Rapoport	depends on NUMA
1601a7f7f624SMasahiro Yamada	help
16021184dc2fSMike Travis	  Specify the maximum number of NUMA Nodes available on the target
1603692105b8SMatt LaPlante	  system.  Increases memory reserved to accommodate various tables.
1604506f1d07SSam Ravnborg
1605506f1d07SSam Ravnborgconfig ARCH_FLATMEM_ENABLE
1606506f1d07SSam Ravnborg	def_bool y
16073b16651fSTejun Heo	depends on X86_32 && !NUMA
1608506f1d07SSam Ravnborg
1609506f1d07SSam Ravnborgconfig ARCH_SPARSEMEM_ENABLE
1610506f1d07SSam Ravnborg	def_bool y
16116ea30386SKees Cook	depends on X86_64 || NUMA || X86_32 || X86_32_NON_STANDARD
1612506f1d07SSam Ravnborg	select SPARSEMEM_STATIC if X86_32
1613506f1d07SSam Ravnborg	select SPARSEMEM_VMEMMAP_ENABLE if X86_64
1614506f1d07SSam Ravnborg
16153b16651fSTejun Heoconfig ARCH_SPARSEMEM_DEFAULT
16166ad57f7fSMike Rapoport	def_bool X86_64 || (NUMA && X86_32)
16173b16651fSTejun Heo
1618506f1d07SSam Ravnborgconfig ARCH_SELECT_MEMORY_MODEL
1619506f1d07SSam Ravnborg	def_bool y
16204eda2bc3SDavid Hildenbrand	depends on ARCH_SPARSEMEM_ENABLE && ARCH_FLATMEM_ENABLE
1621506f1d07SSam Ravnborg
1622506f1d07SSam Ravnborgconfig ARCH_MEMORY_PROBE
1623a0842b70SToshi Kani	bool "Enable sysfs memory/probe interface"
16245c11f00bSDavid Hildenbrand	depends on MEMORY_HOTPLUG
1625a0842b70SToshi Kani	help
1626a0842b70SToshi Kani	  This option enables a sysfs memory/probe interface for testing.
1627cb1aaebeSMauro Carvalho Chehab	  See Documentation/admin-guide/mm/memory-hotplug.rst for more information.
1628a0842b70SToshi Kani	  If you are unsure how to answer this question, answer N.
1629506f1d07SSam Ravnborg
16303b16651fSTejun Heoconfig ARCH_PROC_KCORE_TEXT
16313b16651fSTejun Heo	def_bool y
16323b16651fSTejun Heo	depends on X86_64 && PROC_KCORE
16333b16651fSTejun Heo
1634a29815a3SAvi Kivityconfig ILLEGAL_POINTER_VALUE
1635a29815a3SAvi Kivity	hex
1636a29815a3SAvi Kivity	default 0 if X86_32
1637a29815a3SAvi Kivity	default 0xdead000000000000 if X86_64
1638a29815a3SAvi Kivity
16397a67832cSDan Williamsconfig X86_PMEM_LEGACY_DEVICE
16407a67832cSDan Williams	bool
16417a67832cSDan Williams
1642ec776ef6SChristoph Hellwigconfig X86_PMEM_LEGACY
16437a67832cSDan Williams	tristate "Support non-standard NVDIMMs and ADR protected memory"
16449f53f9faSDan Williams	depends on PHYS_ADDR_T_64BIT
16459f53f9faSDan Williams	depends on BLK_DEV
16467a67832cSDan Williams	select X86_PMEM_LEGACY_DEVICE
16477b27a862SDan Williams	select NUMA_KEEP_MEMINFO if NUMA
16489f53f9faSDan Williams	select LIBNVDIMM
1649ec776ef6SChristoph Hellwig	help
1650ec776ef6SChristoph Hellwig	  Treat memory marked using the non-standard e820 type of 12 as used
1651ec776ef6SChristoph Hellwig	  by the Intel Sandy Bridge-EP reference BIOS as protected memory.
1652ec776ef6SChristoph Hellwig	  The kernel will offer these regions to the 'pmem' driver so
1653ec776ef6SChristoph Hellwig	  they can be used for persistent storage.
1654ec776ef6SChristoph Hellwig
1655ec776ef6SChristoph Hellwig	  Say Y if unsure.
1656ec776ef6SChristoph Hellwig
1657506f1d07SSam Ravnborgconfig HIGHPTE
1658506f1d07SSam Ravnborg	bool "Allocate 3rd-level pagetables from highmem"
16596fc108a0SJan Beulich	depends on HIGHMEM
1660a7f7f624SMasahiro Yamada	help
1661506f1d07SSam Ravnborg	  The VM uses one page table entry for each page of physical memory.
1662506f1d07SSam Ravnborg	  For systems with a lot of RAM, this can be wasteful of precious
1663506f1d07SSam Ravnborg	  low memory.  Setting this option will put user-space page table
1664506f1d07SSam Ravnborg	  entries in high memory.
1665506f1d07SSam Ravnborg
16669f077871SJeremy Fitzhardingeconfig X86_CHECK_BIOS_CORRUPTION
16679f077871SJeremy Fitzhardinge	bool "Check for low memory corruption"
1668a7f7f624SMasahiro Yamada	help
16699f077871SJeremy Fitzhardinge	  Periodically check for memory corruption in low memory, which
16709f077871SJeremy Fitzhardinge	  is suspected to be caused by BIOS.  Even when enabled in the
16719f077871SJeremy Fitzhardinge	  configuration, it is disabled at runtime.  Enable it by
16729f077871SJeremy Fitzhardinge	  setting "memory_corruption_check=1" on the kernel command
16739f077871SJeremy Fitzhardinge	  line.  By default it scans the low 64k of memory every 60
16749f077871SJeremy Fitzhardinge	  seconds; see the memory_corruption_check_size and
16759f077871SJeremy Fitzhardinge	  memory_corruption_check_period parameters in
16768c27ceffSMauro Carvalho Chehab	  Documentation/admin-guide/kernel-parameters.rst to adjust this.
16779f077871SJeremy Fitzhardinge
16789f077871SJeremy Fitzhardinge	  When enabled with the default parameters, this option has
16799f077871SJeremy Fitzhardinge	  almost no overhead, as it reserves a relatively small amount
16809f077871SJeremy Fitzhardinge	  of memory and scans it infrequently.  It both detects corruption
16819f077871SJeremy Fitzhardinge	  and prevents it from affecting the running system.
16829f077871SJeremy Fitzhardinge
16839f077871SJeremy Fitzhardinge	  It is, however, intended as a diagnostic tool; if repeatable
16849f077871SJeremy Fitzhardinge	  BIOS-originated corruption always affects the same memory,
16859f077871SJeremy Fitzhardinge	  you can use memmap= to prevent the kernel from using that
16869f077871SJeremy Fitzhardinge	  memory.
16879f077871SJeremy Fitzhardinge
1688c885df50SJeremy Fitzhardingeconfig X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK
1689c885df50SJeremy Fitzhardinge	bool "Set the default setting of memory_corruption_check"
1690c885df50SJeremy Fitzhardinge	depends on X86_CHECK_BIOS_CORRUPTION
1691c885df50SJeremy Fitzhardinge	default y
1692a7f7f624SMasahiro Yamada	help
1693c885df50SJeremy Fitzhardinge	  Set whether the default state of memory_corruption_check is
1694c885df50SJeremy Fitzhardinge	  on or off.
1695c885df50SJeremy Fitzhardinge
1696506f1d07SSam Ravnborgconfig MATH_EMULATION
1697506f1d07SSam Ravnborg	bool
1698a5b9e5a2SAndy Lutomirski	depends on MODIFY_LDT_SYSCALL
169987d6021bSArnd Bergmann	prompt "Math emulation" if X86_32 && (M486SX || MELAN)
1700a7f7f624SMasahiro Yamada	help
1701506f1d07SSam Ravnborg	  Linux can emulate a math coprocessor (used for floating point
1702506f1d07SSam Ravnborg	  operations) if you don't have one. 486DX and Pentium processors have
1703506f1d07SSam Ravnborg	  a math coprocessor built in, 486SX and 386 do not, unless you added
1704506f1d07SSam Ravnborg	  a 487DX or 387, respectively. (The messages during boot time can
1705506f1d07SSam Ravnborg	  give you some hints here ["man dmesg"].) Everyone needs either a
1706506f1d07SSam Ravnborg	  coprocessor or this emulation.
1707506f1d07SSam Ravnborg
1708506f1d07SSam Ravnborg	  If you don't have a math coprocessor, you need to say Y here; if you
1709506f1d07SSam Ravnborg	  say Y here even though you have a coprocessor, the coprocessor will
1710506f1d07SSam Ravnborg	  be used nevertheless. (This behavior can be changed with the kernel
1711506f1d07SSam Ravnborg	  command line option "no387", which comes handy if your coprocessor
1712506f1d07SSam Ravnborg	  is broken. Try "man bootparam" or see the documentation of your boot
1713506f1d07SSam Ravnborg	  loader (lilo or loadlin) about how to pass options to the kernel at
1714506f1d07SSam Ravnborg	  boot time.) This means that it is a good idea to say Y here if you
1715506f1d07SSam Ravnborg	  intend to use this kernel on different machines.
1716506f1d07SSam Ravnborg
1717506f1d07SSam Ravnborg	  More information about the internals of the Linux math coprocessor
1718506f1d07SSam Ravnborg	  emulation can be found in <file:arch/x86/math-emu/README>.
1719506f1d07SSam Ravnborg
1720506f1d07SSam Ravnborg	  If you are not sure, say Y; apart from resulting in a 66 KB bigger
1721506f1d07SSam Ravnborg	  kernel, it won't hurt.
1722506f1d07SSam Ravnborg
1723506f1d07SSam Ravnborgconfig MTRR
17246fc108a0SJan Beulich	def_bool y
17256a108a14SDavid Rientjes	prompt "MTRR (Memory Type Range Register) support" if EXPERT
1726a7f7f624SMasahiro Yamada	help
1727506f1d07SSam Ravnborg	  On Intel P6 family processors (Pentium Pro, Pentium II and later)
1728506f1d07SSam Ravnborg	  the Memory Type Range Registers (MTRRs) may be used to control
1729506f1d07SSam Ravnborg	  processor access to memory ranges. This is most useful if you have
1730506f1d07SSam Ravnborg	  a video (VGA) card on a PCI or AGP bus. Enabling write-combining
1731506f1d07SSam Ravnborg	  allows bus write transfers to be combined into a larger transfer
1732506f1d07SSam Ravnborg	  before bursting over the PCI/AGP bus. This can increase performance
1733506f1d07SSam Ravnborg	  of image write operations 2.5 times or more. Saying Y here creates a
1734506f1d07SSam Ravnborg	  /proc/mtrr file which may be used to manipulate your processor's
1735506f1d07SSam Ravnborg	  MTRRs. Typically the X server should use this.
1736506f1d07SSam Ravnborg
1737506f1d07SSam Ravnborg	  This code has a reasonably generic interface so that similar
1738506f1d07SSam Ravnborg	  control registers on other processors can be easily supported
1739506f1d07SSam Ravnborg	  as well:
1740506f1d07SSam Ravnborg
1741506f1d07SSam Ravnborg	  The Cyrix 6x86, 6x86MX and M II processors have Address Range
1742506f1d07SSam Ravnborg	  Registers (ARRs) which provide a similar functionality to MTRRs. For
1743506f1d07SSam Ravnborg	  these, the ARRs are used to emulate the MTRRs.
1744506f1d07SSam Ravnborg	  The AMD K6-2 (stepping 8 and above) and K6-3 processors have two
1745506f1d07SSam Ravnborg	  MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing
1746506f1d07SSam Ravnborg	  write-combining. All of these processors are supported by this code
1747506f1d07SSam Ravnborg	  and it makes sense to say Y here if you have one of them.
1748506f1d07SSam Ravnborg
1749506f1d07SSam Ravnborg	  Saying Y here also fixes a problem with buggy SMP BIOSes which only
1750506f1d07SSam Ravnborg	  set the MTRRs for the boot CPU and not for the secondary CPUs. This
1751506f1d07SSam Ravnborg	  can lead to all sorts of problems, so it's good to say Y here.
1752506f1d07SSam Ravnborg
1753506f1d07SSam Ravnborg	  You can safely say Y even if your machine doesn't have MTRRs, you'll
1754506f1d07SSam Ravnborg	  just add about 9 KB to your kernel.
1755506f1d07SSam Ravnborg
1756ff61f079SJonathan Corbet	  See <file:Documentation/arch/x86/mtrr.rst> for more information.
1757506f1d07SSam Ravnborg
175895ffa243SYinghai Luconfig MTRR_SANITIZER
17592ffb3501SYinghai Lu	def_bool y
176095ffa243SYinghai Lu	prompt "MTRR cleanup support"
176195ffa243SYinghai Lu	depends on MTRR
1762a7f7f624SMasahiro Yamada	help
1763aba3728cSThomas Gleixner	  Convert MTRR layout from continuous to discrete, so X drivers can
1764aba3728cSThomas Gleixner	  add writeback entries.
176595ffa243SYinghai Lu
1766aba3728cSThomas Gleixner	  Can be disabled with disable_mtrr_cleanup on the kernel command line.
1767692105b8SMatt LaPlante	  The largest mtrr entry size for a continuous block can be set with
1768aba3728cSThomas Gleixner	  mtrr_chunk_size.
176995ffa243SYinghai Lu
17702ffb3501SYinghai Lu	  If unsure, say Y.
177195ffa243SYinghai Lu
177295ffa243SYinghai Luconfig MTRR_SANITIZER_ENABLE_DEFAULT
1773f5098d62SYinghai Lu	int "MTRR cleanup enable value (0-1)"
1774f5098d62SYinghai Lu	range 0 1
1775f5098d62SYinghai Lu	default "0"
177695ffa243SYinghai Lu	depends on MTRR_SANITIZER
1777a7f7f624SMasahiro Yamada	help
1778f5098d62SYinghai Lu	  Enable mtrr cleanup default value
177995ffa243SYinghai Lu
178012031a62SYinghai Luconfig MTRR_SANITIZER_SPARE_REG_NR_DEFAULT
178112031a62SYinghai Lu	int "MTRR cleanup spare reg num (0-7)"
178212031a62SYinghai Lu	range 0 7
178312031a62SYinghai Lu	default "1"
178412031a62SYinghai Lu	depends on MTRR_SANITIZER
1785a7f7f624SMasahiro Yamada	help
178612031a62SYinghai Lu	  mtrr cleanup spare entries default, it can be changed via
1787aba3728cSThomas Gleixner	  mtrr_spare_reg_nr=N on the kernel command line.
178812031a62SYinghai Lu
17892e5d9c85Svenkatesh.pallipadi@intel.comconfig X86_PAT
17906fc108a0SJan Beulich	def_bool y
17916a108a14SDavid Rientjes	prompt "x86 PAT support" if EXPERT
17922a8a2719SIngo Molnar	depends on MTRR
1793a7f7f624SMasahiro Yamada	help
17942e5d9c85Svenkatesh.pallipadi@intel.com	  Use PAT attributes to setup page level cache control.
1795042b78e4SVenki Pallipadi
17962e5d9c85Svenkatesh.pallipadi@intel.com	  PATs are the modern equivalents of MTRRs and are much more
17972e5d9c85Svenkatesh.pallipadi@intel.com	  flexible than MTRRs.
17982e5d9c85Svenkatesh.pallipadi@intel.com
17992e5d9c85Svenkatesh.pallipadi@intel.com	  Say N here if you see bootup problems (boot crash, boot hang,
1800042b78e4SVenki Pallipadi	  spontaneous reboots) or a non-working video driver.
18012e5d9c85Svenkatesh.pallipadi@intel.com
18022e5d9c85Svenkatesh.pallipadi@intel.com	  If unsure, say Y.
18032e5d9c85Svenkatesh.pallipadi@intel.com
180446cf98cdSVenkatesh Pallipadiconfig ARCH_USES_PG_UNCACHED
180546cf98cdSVenkatesh Pallipadi	def_bool y
180646cf98cdSVenkatesh Pallipadi	depends on X86_PAT
180746cf98cdSVenkatesh Pallipadi
1808b971880fSBabu Mogerconfig X86_UMIP
1809796ebc81SRicardo Neri	def_bool y
1810b971880fSBabu Moger	prompt "User Mode Instruction Prevention" if EXPERT
1811a7f7f624SMasahiro Yamada	help
1812b971880fSBabu Moger	  User Mode Instruction Prevention (UMIP) is a security feature in
1813b971880fSBabu Moger	  some x86 processors. If enabled, a general protection fault is
1814b971880fSBabu Moger	  issued if the SGDT, SLDT, SIDT, SMSW or STR instructions are
1815b971880fSBabu Moger	  executed in user mode. These instructions unnecessarily expose
1816b971880fSBabu Moger	  information about the hardware state.
1817796ebc81SRicardo Neri
1818796ebc81SRicardo Neri	  The vast majority of applications do not use these instructions.
1819796ebc81SRicardo Neri	  For the very few that do, software emulation is provided in
1820796ebc81SRicardo Neri	  specific cases in protected and virtual-8086 modes. Emulated
1821796ebc81SRicardo Neri	  results are dummy.
1822aa35f896SRicardo Neri
1823156ff4a5SPeter Zijlstraconfig CC_HAS_IBT
1824156ff4a5SPeter Zijlstra	# GCC >= 9 and binutils >= 2.29
1825156ff4a5SPeter Zijlstra	# Retpoline check to work around https://gcc.gnu.org/bugzilla/show_bug.cgi?id=93654
1826156ff4a5SPeter Zijlstra	# Clang/LLVM >= 14
1827262448f3SNathan Chancellor	# https://github.com/llvm/llvm-project/commit/e0b89df2e0f0130881bf6c39bf31d7f6aac00e0f
1828262448f3SNathan Chancellor	# https://github.com/llvm/llvm-project/commit/dfcf69770bc522b9e411c66454934a37c1f35332
1829156ff4a5SPeter Zijlstra	def_bool ((CC_IS_GCC && $(cc-option, -fcf-protection=branch -mindirect-branch-register)) || \
1830262448f3SNathan Chancellor		  (CC_IS_CLANG && CLANG_VERSION >= 140000)) && \
1831156ff4a5SPeter Zijlstra		  $(as-instr,endbr64)
1832156ff4a5SPeter Zijlstra
183318e66b69SRick Edgecombeconfig X86_CET
183418e66b69SRick Edgecombe	def_bool n
183518e66b69SRick Edgecombe	help
183618e66b69SRick Edgecombe	  CET features configured (Shadow stack or IBT)
183718e66b69SRick Edgecombe
1838156ff4a5SPeter Zijlstraconfig X86_KERNEL_IBT
1839156ff4a5SPeter Zijlstra	prompt "Indirect Branch Tracking"
18404fd5f70cSKees Cook	def_bool y
184103f16cd0SJosh Poimboeuf	depends on X86_64 && CC_HAS_IBT && HAVE_OBJTOOL
1842f6a2c2b2SNathan Chancellor	# https://github.com/llvm/llvm-project/commit/9d7001eba9c4cb311e03cd8cdc231f9e579f2d0f
1843f6a2c2b2SNathan Chancellor	depends on !LD_IS_LLD || LLD_VERSION >= 140000
184403f16cd0SJosh Poimboeuf	select OBJTOOL
184518e66b69SRick Edgecombe	select X86_CET
1846156ff4a5SPeter Zijlstra	help
1847156ff4a5SPeter Zijlstra	  Build the kernel with support for Indirect Branch Tracking, a
1848156ff4a5SPeter Zijlstra	  hardware support course-grain forward-edge Control Flow Integrity
1849156ff4a5SPeter Zijlstra	  protection. It enforces that all indirect calls must land on
1850156ff4a5SPeter Zijlstra	  an ENDBR instruction, as such, the compiler will instrument the
1851156ff4a5SPeter Zijlstra	  code with them to make this happen.
1852156ff4a5SPeter Zijlstra
1853ed53a0d9SPeter Zijlstra	  In addition to building the kernel with IBT, seal all functions that
18544cdfc11bSNur Hussein	  are not indirect call targets, avoiding them ever becoming one.
1855ed53a0d9SPeter Zijlstra
1856ed53a0d9SPeter Zijlstra	  This requires LTO like objtool runs and will slow down the build. It
1857ed53a0d9SPeter Zijlstra	  does significantly reduce the number of ENDBR instructions in the
1858ed53a0d9SPeter Zijlstra	  kernel image.
1859ed53a0d9SPeter Zijlstra
186035e97790SDave Hansenconfig X86_INTEL_MEMORY_PROTECTION_KEYS
186138f3e775SBabu Moger	prompt "Memory Protection Keys"
186235e97790SDave Hansen	def_bool y
1863284244a9SDave Hansen	# Note: only available in 64-bit mode
186438f3e775SBabu Moger	depends on X86_64 && (CPU_SUP_INTEL || CPU_SUP_AMD)
186552c8e601SIngo Molnar	select ARCH_USES_HIGH_VMA_FLAGS
186652c8e601SIngo Molnar	select ARCH_HAS_PKEYS
1867a7f7f624SMasahiro Yamada	help
1868284244a9SDave Hansen	  Memory Protection Keys provides a mechanism for enforcing
1869284244a9SDave Hansen	  page-based protections, but without requiring modification of the
1870284244a9SDave Hansen	  page tables when an application changes protection domains.
1871284244a9SDave Hansen
18721eecbcdcSMauro Carvalho Chehab	  For details, see Documentation/core-api/protection-keys.rst
1873284244a9SDave Hansen
1874284244a9SDave Hansen	  If unsure, say y.
187535e97790SDave Hansen
1876db616173SMichal Hockochoice
1877db616173SMichal Hocko	prompt "TSX enable mode"
1878db616173SMichal Hocko	depends on CPU_SUP_INTEL
1879db616173SMichal Hocko	default X86_INTEL_TSX_MODE_OFF
1880db616173SMichal Hocko	help
1881db616173SMichal Hocko	  Intel's TSX (Transactional Synchronization Extensions) feature
1882db616173SMichal Hocko	  allows to optimize locking protocols through lock elision which
1883db616173SMichal Hocko	  can lead to a noticeable performance boost.
1884db616173SMichal Hocko
1885db616173SMichal Hocko	  On the other hand it has been shown that TSX can be exploited
1886db616173SMichal Hocko	  to form side channel attacks (e.g. TAA) and chances are there
1887db616173SMichal Hocko	  will be more of those attacks discovered in the future.
1888db616173SMichal Hocko
1889db616173SMichal Hocko	  Therefore TSX is not enabled by default (aka tsx=off). An admin
1890db616173SMichal Hocko	  might override this decision by tsx=on the command line parameter.
1891db616173SMichal Hocko	  Even with TSX enabled, the kernel will attempt to enable the best
1892db616173SMichal Hocko	  possible TAA mitigation setting depending on the microcode available
1893db616173SMichal Hocko	  for the particular machine.
1894db616173SMichal Hocko
1895db616173SMichal Hocko	  This option allows to set the default tsx mode between tsx=on, =off
1896db616173SMichal Hocko	  and =auto. See Documentation/admin-guide/kernel-parameters.txt for more
1897db616173SMichal Hocko	  details.
1898db616173SMichal Hocko
1899db616173SMichal Hocko	  Say off if not sure, auto if TSX is in use but it should be used on safe
1900db616173SMichal Hocko	  platforms or on if TSX is in use and the security aspect of tsx is not
1901db616173SMichal Hocko	  relevant.
1902db616173SMichal Hocko
1903db616173SMichal Hockoconfig X86_INTEL_TSX_MODE_OFF
1904db616173SMichal Hocko	bool "off"
1905db616173SMichal Hocko	help
1906db616173SMichal Hocko	  TSX is disabled if possible - equals to tsx=off command line parameter.
1907db616173SMichal Hocko
1908db616173SMichal Hockoconfig X86_INTEL_TSX_MODE_ON
1909db616173SMichal Hocko	bool "on"
1910db616173SMichal Hocko	help
1911db616173SMichal Hocko	  TSX is always enabled on TSX capable HW - equals the tsx=on command
1912db616173SMichal Hocko	  line parameter.
1913db616173SMichal Hocko
1914db616173SMichal Hockoconfig X86_INTEL_TSX_MODE_AUTO
1915db616173SMichal Hocko	bool "auto"
1916db616173SMichal Hocko	help
1917db616173SMichal Hocko	  TSX is enabled on TSX capable HW that is believed to be safe against
1918db616173SMichal Hocko	  side channel attacks- equals the tsx=auto command line parameter.
1919db616173SMichal Hockoendchoice
1920db616173SMichal Hocko
1921e7e05452SSean Christophersonconfig X86_SGX
1922e7e05452SSean Christopherson	bool "Software Guard eXtensions (SGX)"
1923b8d1d163SDaniel Sneddon	depends on X86_64 && CPU_SUP_INTEL && X86_X2APIC
1924e7e05452SSean Christopherson	depends on CRYPTO=y
1925e7e05452SSean Christopherson	depends on CRYPTO_SHA256=y
1926e7e05452SSean Christopherson	select MMU_NOTIFIER
1927901ddbb9SJarkko Sakkinen	select NUMA_KEEP_MEMINFO if NUMA
192840e0e784STony Luck	select XARRAY_MULTI
1929e7e05452SSean Christopherson	help
1930e7e05452SSean Christopherson	  Intel(R) Software Guard eXtensions (SGX) is a set of CPU instructions
1931e7e05452SSean Christopherson	  that can be used by applications to set aside private regions of code
1932e7e05452SSean Christopherson	  and data, referred to as enclaves. An enclave's private memory can
1933e7e05452SSean Christopherson	  only be accessed by code running within the enclave. Accesses from
1934e7e05452SSean Christopherson	  outside the enclave, including other enclaves, are disallowed by
1935e7e05452SSean Christopherson	  hardware.
1936e7e05452SSean Christopherson
1937e7e05452SSean Christopherson	  If unsure, say N.
1938e7e05452SSean Christopherson
193918e66b69SRick Edgecombeconfig X86_USER_SHADOW_STACK
194018e66b69SRick Edgecombe	bool "X86 userspace shadow stack"
194118e66b69SRick Edgecombe	depends on AS_WRUSS
194218e66b69SRick Edgecombe	depends on X86_64
194318e66b69SRick Edgecombe	select ARCH_USES_HIGH_VMA_FLAGS
194418e66b69SRick Edgecombe	select X86_CET
194518e66b69SRick Edgecombe	help
194618e66b69SRick Edgecombe	  Shadow stack protection is a hardware feature that detects function
194718e66b69SRick Edgecombe	  return address corruption.  This helps mitigate ROP attacks.
194818e66b69SRick Edgecombe	  Applications must be enabled to use it, and old userspace does not
194918e66b69SRick Edgecombe	  get protection "for free".
195018e66b69SRick Edgecombe
195118e66b69SRick Edgecombe	  CPUs supporting shadow stacks were first released in 2020.
195218e66b69SRick Edgecombe
195354acee60SDave Hansen	  See Documentation/arch/x86/shstk.rst for more information.
195418e66b69SRick Edgecombe
195518e66b69SRick Edgecombe	  If unsure, say N.
195618e66b69SRick Edgecombe
1957506f1d07SSam Ravnborgconfig EFI
19589ba16087SJan Beulich	bool "EFI runtime service support"
19595b83683fSHuang, Ying	depends on ACPI
1960f6ce5002SSergey Vlasov	select UCS2_STRING
1961022ee6c5SArd Biesheuvel	select EFI_RUNTIME_WRAPPERS
19621ff2fc02STom Lendacky	select ARCH_USE_MEMREMAP_PROT
1963aba7e066SArd Biesheuvel	select EFI_RUNTIME_MAP if KEXEC_CORE
1964a7f7f624SMasahiro Yamada	help
19658b2cb7a8SHuang, Ying	  This enables the kernel to use EFI runtime services that are
1966506f1d07SSam Ravnborg	  available (such as the EFI variable services).
1967506f1d07SSam Ravnborg
19688b2cb7a8SHuang, Ying	  This option is only useful on systems that have EFI firmware.
19698b2cb7a8SHuang, Ying	  In addition, you should use the latest ELILO loader available
19708b2cb7a8SHuang, Ying	  at <http://elilo.sourceforge.net> in order to take advantage
19718b2cb7a8SHuang, Ying	  of EFI runtime services. However, even with this option, the
19728b2cb7a8SHuang, Ying	  resultant kernel should continue to boot on existing non-EFI
19738b2cb7a8SHuang, Ying	  platforms.
1974506f1d07SSam Ravnborg
1975291f3632SMatt Flemingconfig EFI_STUB
1976291f3632SMatt Fleming	bool "EFI stub support"
1977c6dbd3e5SPeter Zijlstra	depends on EFI
19787b2a583aSMatt Fleming	select RELOCATABLE
1979a7f7f624SMasahiro Yamada	help
1980291f3632SMatt Fleming	  This kernel feature allows a bzImage to be loaded directly
1981291f3632SMatt Fleming	  by EFI firmware without the use of a bootloader.
1982291f3632SMatt Fleming
19834f4cfa6cSMauro Carvalho Chehab	  See Documentation/admin-guide/efi-stub.rst for more information.
19840c759662SMatt Fleming
1985cc3fdda2SArd Biesheuvelconfig EFI_HANDOVER_PROTOCOL
1986cc3fdda2SArd Biesheuvel	bool "EFI handover protocol (DEPRECATED)"
1987cc3fdda2SArd Biesheuvel	depends on EFI_STUB
1988cc3fdda2SArd Biesheuvel	default y
1989cc3fdda2SArd Biesheuvel	help
1990cc3fdda2SArd Biesheuvel	  Select this in order to include support for the deprecated EFI
1991cc3fdda2SArd Biesheuvel	  handover protocol, which defines alternative entry points into the
1992cc3fdda2SArd Biesheuvel	  EFI stub.  This is a practice that has no basis in the UEFI
1993cc3fdda2SArd Biesheuvel	  specification, and requires a priori knowledge on the part of the
1994cc3fdda2SArd Biesheuvel	  bootloader about Linux/x86 specific ways of passing the command line
1995cc3fdda2SArd Biesheuvel	  and initrd, and where in memory those assets may be loaded.
1996cc3fdda2SArd Biesheuvel
1997cc3fdda2SArd Biesheuvel	  If in doubt, say Y. Even though the corresponding support is not
1998cc3fdda2SArd Biesheuvel	  present in upstream GRUB or other bootloaders, most distros build
1999cc3fdda2SArd Biesheuvel	  GRUB with numerous downstream patches applied, and may rely on the
2000cc3fdda2SArd Biesheuvel	  handover protocol as as result.
2001cc3fdda2SArd Biesheuvel
20027d453eeeSMatt Flemingconfig EFI_MIXED
20037d453eeeSMatt Fleming	bool "EFI mixed-mode support"
20047d453eeeSMatt Fleming	depends on EFI_STUB && X86_64
2005a7f7f624SMasahiro Yamada	help
20067d453eeeSMatt Fleming	  Enabling this feature allows a 64-bit kernel to be booted
20077d453eeeSMatt Fleming	  on a 32-bit firmware, provided that your CPU supports 64-bit
20087d453eeeSMatt Fleming	  mode.
20097d453eeeSMatt Fleming
20107d453eeeSMatt Fleming	  Note that it is not possible to boot a mixed-mode enabled
20117d453eeeSMatt Fleming	  kernel via the EFI boot stub - a bootloader that supports
20127d453eeeSMatt Fleming	  the EFI handover protocol must be used.
20137d453eeeSMatt Fleming
20147d453eeeSMatt Fleming	  If unsure, say N.
20157d453eeeSMatt Fleming
20164059ba65SArd Biesheuvelconfig EFI_FAKE_MEMMAP
20174059ba65SArd Biesheuvel	bool "Enable EFI fake memory map"
20184059ba65SArd Biesheuvel	depends on EFI
20194059ba65SArd Biesheuvel	help
20204059ba65SArd Biesheuvel	  Saying Y here will enable "efi_fake_mem" boot option.  By specifying
20214059ba65SArd Biesheuvel	  this parameter, you can add arbitrary attribute to specific memory
20224059ba65SArd Biesheuvel	  range by updating original (firmware provided) EFI memmap.  This is
20234059ba65SArd Biesheuvel	  useful for debugging of EFI memmap related feature, e.g., Address
20244059ba65SArd Biesheuvel	  Range Mirroring feature.
20254059ba65SArd Biesheuvel
20264059ba65SArd Biesheuvelconfig EFI_MAX_FAKE_MEM
20274059ba65SArd Biesheuvel	int "maximum allowable number of ranges in efi_fake_mem boot option"
20284059ba65SArd Biesheuvel	depends on EFI_FAKE_MEMMAP
20294059ba65SArd Biesheuvel	range 1 128
20304059ba65SArd Biesheuvel	default 8
20314059ba65SArd Biesheuvel	help
20324059ba65SArd Biesheuvel	  Maximum allowable number of ranges in efi_fake_mem boot option.
20334059ba65SArd Biesheuvel	  Ranges can be set up to this value using comma-separated list.
20344059ba65SArd Biesheuvel	  The default value is 8.
20354059ba65SArd Biesheuvel
20361fff234dSArd Biesheuvelconfig EFI_RUNTIME_MAP
20371fff234dSArd Biesheuvel	bool "Export EFI runtime maps to sysfs" if EXPERT
20381fff234dSArd Biesheuvel	depends on EFI
20391fff234dSArd Biesheuvel	help
20401fff234dSArd Biesheuvel	  Export EFI runtime memory regions to /sys/firmware/efi/runtime-map.
20411fff234dSArd Biesheuvel	  That memory map is required by the 2nd kernel to set up EFI virtual
20421fff234dSArd Biesheuvel	  mappings after kexec, but can also be used for debugging purposes.
20431fff234dSArd Biesheuvel
20441fff234dSArd Biesheuvel	  See also Documentation/ABI/testing/sysfs-firmware-efi-runtime-map.
20451fff234dSArd Biesheuvel
20468636a1f9SMasahiro Yamadasource "kernel/Kconfig.hz"
2047506f1d07SSam Ravnborg
20486af51380SEric DeVolderconfig ARCH_SUPPORTS_KEXEC
20496af51380SEric DeVolder	def_bool y
2050506f1d07SSam Ravnborg
20516af51380SEric DeVolderconfig ARCH_SUPPORTS_KEXEC_FILE
205278422b74SArnd Bergmann	def_bool X86_64
2053506f1d07SSam Ravnborg
20546af51380SEric DeVolderconfig ARCH_SELECTS_KEXEC_FILE
20556af51380SEric DeVolder	def_bool y
20566af51380SEric DeVolder	depends on KEXEC_FILE
2057b69a2afdSJonathan McDowell	select HAVE_IMA_KEXEC if IMA
205874ca317cSVivek Goyal
2059e6265fe7SEric DeVolderconfig ARCH_SUPPORTS_KEXEC_PURGATORY
206078422b74SArnd Bergmann	def_bool y
2061b799a09fSAKASHI Takahiro
20626af51380SEric DeVolderconfig ARCH_SUPPORTS_KEXEC_SIG
20636af51380SEric DeVolder	def_bool y
206499d5cadfSJiri Bohac
20656af51380SEric DeVolderconfig ARCH_SUPPORTS_KEXEC_SIG_FORCE
20666af51380SEric DeVolder	def_bool y
206799d5cadfSJiri Bohac
20686af51380SEric DeVolderconfig ARCH_SUPPORTS_KEXEC_BZIMAGE_VERIFY_SIG
20696af51380SEric DeVolder	def_bool y
207099d5cadfSJiri Bohac
20716af51380SEric DeVolderconfig ARCH_SUPPORTS_KEXEC_JUMP
20726af51380SEric DeVolder	def_bool y
20738e7d8381SVivek Goyal
20746af51380SEric DeVolderconfig ARCH_SUPPORTS_CRASH_DUMP
20756af51380SEric DeVolder	def_bool X86_64 || (X86_32 && HIGHMEM)
20768e7d8381SVivek Goyal
2077ea53ad9cSEric DeVolderconfig ARCH_SUPPORTS_CRASH_HOTPLUG
2078ea53ad9cSEric DeVolder	def_bool y
20793ab83521SHuang Ying
2080506f1d07SSam Ravnborgconfig PHYSICAL_START
20816a108a14SDavid Rientjes	hex "Physical address where the kernel is loaded" if (EXPERT || CRASH_DUMP)
2082ceefccc9SH. Peter Anvin	default "0x1000000"
2083a7f7f624SMasahiro Yamada	help
2084506f1d07SSam Ravnborg	  This gives the physical address where the kernel is loaded.
2085506f1d07SSam Ravnborg
2086506f1d07SSam Ravnborg	  If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then
2087506f1d07SSam Ravnborg	  bzImage will decompress itself to above physical address and
2088506f1d07SSam Ravnborg	  run from there. Otherwise, bzImage will run from the address where
2089506f1d07SSam Ravnborg	  it has been loaded by the boot loader and will ignore above physical
2090506f1d07SSam Ravnborg	  address.
2091506f1d07SSam Ravnborg
2092506f1d07SSam Ravnborg	  In normal kdump cases one does not have to set/change this option
2093506f1d07SSam Ravnborg	  as now bzImage can be compiled as a completely relocatable image
2094506f1d07SSam Ravnborg	  (CONFIG_RELOCATABLE=y) and be used to load and run from a different
2095506f1d07SSam Ravnborg	  address. This option is mainly useful for the folks who don't want
2096506f1d07SSam Ravnborg	  to use a bzImage for capturing the crash dump and want to use a
2097506f1d07SSam Ravnborg	  vmlinux instead. vmlinux is not relocatable hence a kernel needs
2098506f1d07SSam Ravnborg	  to be specifically compiled to run from a specific memory area
2099506f1d07SSam Ravnborg	  (normally a reserved region) and this option comes handy.
2100506f1d07SSam Ravnborg
2101ceefccc9SH. Peter Anvin	  So if you are using bzImage for capturing the crash dump,
2102ceefccc9SH. Peter Anvin	  leave the value here unchanged to 0x1000000 and set
2103ceefccc9SH. Peter Anvin	  CONFIG_RELOCATABLE=y.  Otherwise if you plan to use vmlinux
2104ceefccc9SH. Peter Anvin	  for capturing the crash dump change this value to start of
2105ceefccc9SH. Peter Anvin	  the reserved region.  In other words, it can be set based on
2106ceefccc9SH. Peter Anvin	  the "X" value as specified in the "crashkernel=YM@XM"
2107ceefccc9SH. Peter Anvin	  command line boot parameter passed to the panic-ed
2108330d4810SMauro Carvalho Chehab	  kernel. Please take a look at Documentation/admin-guide/kdump/kdump.rst
2109ceefccc9SH. Peter Anvin	  for more details about crash dumps.
2110506f1d07SSam Ravnborg
2111506f1d07SSam Ravnborg	  Usage of bzImage for capturing the crash dump is recommended as
2112506f1d07SSam Ravnborg	  one does not have to build two kernels. Same kernel can be used
2113506f1d07SSam Ravnborg	  as production kernel and capture kernel. Above option should have
2114506f1d07SSam Ravnborg	  gone away after relocatable bzImage support is introduced. But it
2115506f1d07SSam Ravnborg	  is present because there are users out there who continue to use
2116506f1d07SSam Ravnborg	  vmlinux for dump capture. This option should go away down the
2117506f1d07SSam Ravnborg	  line.
2118506f1d07SSam Ravnborg
2119506f1d07SSam Ravnborg	  Don't change this unless you know what you are doing.
2120506f1d07SSam Ravnborg
2121506f1d07SSam Ravnborgconfig RELOCATABLE
212226717808SH. Peter Anvin	bool "Build a relocatable kernel"
212326717808SH. Peter Anvin	default y
2124a7f7f624SMasahiro Yamada	help
2125506f1d07SSam Ravnborg	  This builds a kernel image that retains relocation information
2126506f1d07SSam Ravnborg	  so it can be loaded someplace besides the default 1MB.
2127506f1d07SSam Ravnborg	  The relocations tend to make the kernel binary about 10% larger,
2128506f1d07SSam Ravnborg	  but are discarded at runtime.
2129506f1d07SSam Ravnborg
2130506f1d07SSam Ravnborg	  One use is for the kexec on panic case where the recovery kernel
2131506f1d07SSam Ravnborg	  must live at a different physical address than the primary
2132506f1d07SSam Ravnborg	  kernel.
2133506f1d07SSam Ravnborg
2134506f1d07SSam Ravnborg	  Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address
2135506f1d07SSam Ravnborg	  it has been loaded at and the compile time physical address
21368ab3820fSKees Cook	  (CONFIG_PHYSICAL_START) is used as the minimum location.
2137506f1d07SSam Ravnborg
21388ab3820fSKees Cookconfig RANDOMIZE_BASE
2139e8581e3dSBaoquan He	bool "Randomize the address of the kernel image (KASLR)"
21408ab3820fSKees Cook	depends on RELOCATABLE
21416807c846SIngo Molnar	default y
2142a7f7f624SMasahiro Yamada	help
2143e8581e3dSBaoquan He	  In support of Kernel Address Space Layout Randomization (KASLR),
2144e8581e3dSBaoquan He	  this randomizes the physical address at which the kernel image
2145e8581e3dSBaoquan He	  is decompressed and the virtual address where the kernel
2146e8581e3dSBaoquan He	  image is mapped, as a security feature that deters exploit
2147e8581e3dSBaoquan He	  attempts relying on knowledge of the location of kernel
2148e8581e3dSBaoquan He	  code internals.
2149e8581e3dSBaoquan He
2150ed9f007eSKees Cook	  On 64-bit, the kernel physical and virtual addresses are
2151ed9f007eSKees Cook	  randomized separately. The physical address will be anywhere
2152ed9f007eSKees Cook	  between 16MB and the top of physical memory (up to 64TB). The
2153ed9f007eSKees Cook	  virtual address will be randomized from 16MB up to 1GB (9 bits
2154ed9f007eSKees Cook	  of entropy). Note that this also reduces the memory space
2155ed9f007eSKees Cook	  available to kernel modules from 1.5GB to 1GB.
2156ed9f007eSKees Cook
2157ed9f007eSKees Cook	  On 32-bit, the kernel physical and virtual addresses are
2158ed9f007eSKees Cook	  randomized together. They will be randomized from 16MB up to
2159ed9f007eSKees Cook	  512MB (8 bits of entropy).
21608ab3820fSKees Cook
2161a653f356SKees Cook	  Entropy is generated using the RDRAND instruction if it is
2162e8581e3dSBaoquan He	  supported. If RDTSC is supported, its value is mixed into
2163e8581e3dSBaoquan He	  the entropy pool as well. If neither RDRAND nor RDTSC are
2164ed9f007eSKees Cook	  supported, then entropy is read from the i8254 timer. The
2165ed9f007eSKees Cook	  usable entropy is limited by the kernel being built using
2166ed9f007eSKees Cook	  2GB addressing, and that PHYSICAL_ALIGN must be at a
2167ed9f007eSKees Cook	  minimum of 2MB. As a result, only 10 bits of entropy are
2168ed9f007eSKees Cook	  theoretically possible, but the implementations are further
2169ed9f007eSKees Cook	  limited due to memory layouts.
2170e8581e3dSBaoquan He
21716807c846SIngo Molnar	  If unsure, say Y.
2172da2b6fb9SKees Cook
21738ab3820fSKees Cook# Relocation on x86 needs some additional build support
2174845adf72SH. Peter Anvinconfig X86_NEED_RELOCS
2175845adf72SH. Peter Anvin	def_bool y
21768ab3820fSKees Cook	depends on RANDOMIZE_BASE || (X86_32 && RELOCATABLE)
2177845adf72SH. Peter Anvin
2178506f1d07SSam Ravnborgconfig PHYSICAL_ALIGN
2179a0215061SKees Cook	hex "Alignment value to which kernel should be aligned"
21808ab3820fSKees Cook	default "0x200000"
2181a0215061SKees Cook	range 0x2000 0x1000000 if X86_32
2182a0215061SKees Cook	range 0x200000 0x1000000 if X86_64
2183a7f7f624SMasahiro Yamada	help
2184506f1d07SSam Ravnborg	  This value puts the alignment restrictions on physical address
2185506f1d07SSam Ravnborg	  where kernel is loaded and run from. Kernel is compiled for an
2186506f1d07SSam Ravnborg	  address which meets above alignment restriction.
2187506f1d07SSam Ravnborg
2188506f1d07SSam Ravnborg	  If bootloader loads the kernel at a non-aligned address and
2189506f1d07SSam Ravnborg	  CONFIG_RELOCATABLE is set, kernel will move itself to nearest
2190506f1d07SSam Ravnborg	  address aligned to above value and run from there.
2191506f1d07SSam Ravnborg
2192506f1d07SSam Ravnborg	  If bootloader loads the kernel at a non-aligned address and
2193506f1d07SSam Ravnborg	  CONFIG_RELOCATABLE is not set, kernel will ignore the run time
2194506f1d07SSam Ravnborg	  load address and decompress itself to the address it has been
2195506f1d07SSam Ravnborg	  compiled for and run from there. The address for which kernel is
2196506f1d07SSam Ravnborg	  compiled already meets above alignment restrictions. Hence the
2197506f1d07SSam Ravnborg	  end result is that kernel runs from a physical address meeting
2198506f1d07SSam Ravnborg	  above alignment restrictions.
2199506f1d07SSam Ravnborg
2200a0215061SKees Cook	  On 32-bit this value must be a multiple of 0x2000. On 64-bit
2201a0215061SKees Cook	  this value must be a multiple of 0x200000.
2202a0215061SKees Cook
2203506f1d07SSam Ravnborg	  Don't change this unless you know what you are doing.
2204506f1d07SSam Ravnborg
2205eedb92abSKirill A. Shutemovconfig DYNAMIC_MEMORY_LAYOUT
2206eedb92abSKirill A. Shutemov	bool
2207a7f7f624SMasahiro Yamada	help
2208eedb92abSKirill A. Shutemov	  This option makes base addresses of vmalloc and vmemmap as well as
2209eedb92abSKirill A. Shutemov	  __PAGE_OFFSET movable during boot.
2210eedb92abSKirill A. Shutemov
22110483e1faSThomas Garnierconfig RANDOMIZE_MEMORY
22120483e1faSThomas Garnier	bool "Randomize the kernel memory sections"
22130483e1faSThomas Garnier	depends on X86_64
22140483e1faSThomas Garnier	depends on RANDOMIZE_BASE
2215eedb92abSKirill A. Shutemov	select DYNAMIC_MEMORY_LAYOUT
22160483e1faSThomas Garnier	default RANDOMIZE_BASE
2217a7f7f624SMasahiro Yamada	help
22180483e1faSThomas Garnier	  Randomizes the base virtual address of kernel memory sections
22190483e1faSThomas Garnier	  (physical memory mapping, vmalloc & vmemmap). This security feature
22200483e1faSThomas Garnier	  makes exploits relying on predictable memory locations less reliable.
22210483e1faSThomas Garnier
22220483e1faSThomas Garnier	  The order of allocations remains unchanged. Entropy is generated in
22230483e1faSThomas Garnier	  the same way as RANDOMIZE_BASE. Current implementation in the optimal
22240483e1faSThomas Garnier	  configuration have in average 30,000 different possible virtual
22250483e1faSThomas Garnier	  addresses for each memory section.
22260483e1faSThomas Garnier
22276807c846SIngo Molnar	  If unsure, say Y.
22280483e1faSThomas Garnier
222990397a41SThomas Garnierconfig RANDOMIZE_MEMORY_PHYSICAL_PADDING
223090397a41SThomas Garnier	hex "Physical memory mapping padding" if EXPERT
223190397a41SThomas Garnier	depends on RANDOMIZE_MEMORY
223290397a41SThomas Garnier	default "0xa" if MEMORY_HOTPLUG
223390397a41SThomas Garnier	default "0x0"
223490397a41SThomas Garnier	range 0x1 0x40 if MEMORY_HOTPLUG
223590397a41SThomas Garnier	range 0x0 0x40
2236a7f7f624SMasahiro Yamada	help
223790397a41SThomas Garnier	  Define the padding in terabytes added to the existing physical
223890397a41SThomas Garnier	  memory size during kernel memory randomization. It is useful
223990397a41SThomas Garnier	  for memory hotplug support but reduces the entropy available for
224090397a41SThomas Garnier	  address randomization.
224190397a41SThomas Garnier
224290397a41SThomas Garnier	  If unsure, leave at the default value.
224390397a41SThomas Garnier
22446449dcb0SKirill A. Shutemovconfig ADDRESS_MASKING
22456449dcb0SKirill A. Shutemov	bool "Linear Address Masking support"
22466449dcb0SKirill A. Shutemov	depends on X86_64
224760a5ba56SPawan Gupta	depends on COMPILE_TEST || !CPU_MITIGATIONS # wait for LASS
22486449dcb0SKirill A. Shutemov	help
22496449dcb0SKirill A. Shutemov	  Linear Address Masking (LAM) modifies the checking that is applied
22506449dcb0SKirill A. Shutemov	  to 64-bit linear addresses, allowing software to use of the
22516449dcb0SKirill A. Shutemov	  untranslated address bits for metadata.
22526449dcb0SKirill A. Shutemov
22536449dcb0SKirill A. Shutemov	  The capability can be used for efficient address sanitizers (ASAN)
22546449dcb0SKirill A. Shutemov	  implementation and for optimizations in JITs.
22556449dcb0SKirill A. Shutemov
2256506f1d07SSam Ravnborgconfig HOTPLUG_CPU
2257bebd024eSThomas Gleixner	def_bool y
225840b31360SStephen Rothwell	depends on SMP
2259506f1d07SSam Ravnborg
2260506f1d07SSam Ravnborgconfig COMPAT_VDSO
2261b0b49f26SAndy Lutomirski	def_bool n
2262b0b49f26SAndy Lutomirski	prompt "Disable the 32-bit vDSO (needed for glibc 2.3.3)"
2263953fee1dSIngo Molnar	depends on COMPAT_32
2264a7f7f624SMasahiro Yamada	help
2265b0b49f26SAndy Lutomirski	  Certain buggy versions of glibc will crash if they are
2266b0b49f26SAndy Lutomirski	  presented with a 32-bit vDSO that is not mapped at the address
2267b0b49f26SAndy Lutomirski	  indicated in its segment table.
2268e84446deSRandy Dunlap
2269b0b49f26SAndy Lutomirski	  The bug was introduced by f866314b89d56845f55e6f365e18b31ec978ec3a
2270b0b49f26SAndy Lutomirski	  and fixed by 3b3ddb4f7db98ec9e912ccdf54d35df4aa30e04a and
2271b0b49f26SAndy Lutomirski	  49ad572a70b8aeb91e57483a11dd1b77e31c4468.  Glibc 2.3.3 is
2272b0b49f26SAndy Lutomirski	  the only released version with the bug, but OpenSUSE 9
2273b0b49f26SAndy Lutomirski	  contains a buggy "glibc 2.3.2".
2274506f1d07SSam Ravnborg
2275b0b49f26SAndy Lutomirski	  The symptom of the bug is that everything crashes on startup, saying:
2276b0b49f26SAndy Lutomirski	  dl_main: Assertion `(void *) ph->p_vaddr == _rtld_local._dl_sysinfo_dso' failed!
2277b0b49f26SAndy Lutomirski
2278b0b49f26SAndy Lutomirski	  Saying Y here changes the default value of the vdso32 boot
2279b0b49f26SAndy Lutomirski	  option from 1 to 0, which turns off the 32-bit vDSO entirely.
2280b0b49f26SAndy Lutomirski	  This works around the glibc bug but hurts performance.
2281b0b49f26SAndy Lutomirski
2282b0b49f26SAndy Lutomirski	  If unsure, say N: if you are compiling your own kernel, you
2283b0b49f26SAndy Lutomirski	  are unlikely to be using a buggy version of glibc.
2284506f1d07SSam Ravnborg
22853dc33bd3SKees Cookchoice
22863dc33bd3SKees Cook	prompt "vsyscall table for legacy applications"
22873dc33bd3SKees Cook	depends on X86_64
2288625b7b7fSAndy Lutomirski	default LEGACY_VSYSCALL_XONLY
22893dc33bd3SKees Cook	help
22903dc33bd3SKees Cook	  Legacy user code that does not know how to find the vDSO expects
22913dc33bd3SKees Cook	  to be able to issue three syscalls by calling fixed addresses in
22923dc33bd3SKees Cook	  kernel space. Since this location is not randomized with ASLR,
22933dc33bd3SKees Cook	  it can be used to assist security vulnerability exploitation.
22943dc33bd3SKees Cook
22953dc33bd3SKees Cook	  This setting can be changed at boot time via the kernel command
2296bf00745eSAndy Lutomirski	  line parameter vsyscall=[emulate|xonly|none].  Emulate mode
2297bf00745eSAndy Lutomirski	  is deprecated and can only be enabled using the kernel command
2298bf00745eSAndy Lutomirski	  line.
22993dc33bd3SKees Cook
23003dc33bd3SKees Cook	  On a system with recent enough glibc (2.14 or newer) and no
23013dc33bd3SKees Cook	  static binaries, you can say None without a performance penalty
23023dc33bd3SKees Cook	  to improve security.
23033dc33bd3SKees Cook
2304bd49e16eSAndy Lutomirski	  If unsure, select "Emulate execution only".
23053dc33bd3SKees Cook
2306bd49e16eSAndy Lutomirski	config LEGACY_VSYSCALL_XONLY
2307bd49e16eSAndy Lutomirski		bool "Emulate execution only"
2308bd49e16eSAndy Lutomirski		help
2309bd49e16eSAndy Lutomirski		  The kernel traps and emulates calls into the fixed vsyscall
2310bd49e16eSAndy Lutomirski		  address mapping and does not allow reads.  This
2311bd49e16eSAndy Lutomirski		  configuration is recommended when userspace might use the
2312bd49e16eSAndy Lutomirski		  legacy vsyscall area but support for legacy binary
2313bd49e16eSAndy Lutomirski		  instrumentation of legacy code is not needed.  It mitigates
2314bd49e16eSAndy Lutomirski		  certain uses of the vsyscall area as an ASLR-bypassing
2315bd49e16eSAndy Lutomirski		  buffer.
23163dc33bd3SKees Cook
23173dc33bd3SKees Cook	config LEGACY_VSYSCALL_NONE
23183dc33bd3SKees Cook		bool "None"
23193dc33bd3SKees Cook		help
23203dc33bd3SKees Cook		  There will be no vsyscall mapping at all. This will
23213dc33bd3SKees Cook		  eliminate any risk of ASLR bypass due to the vsyscall
23223dc33bd3SKees Cook		  fixed address mapping. Attempts to use the vsyscalls
23233dc33bd3SKees Cook		  will be reported to dmesg, so that either old or
23243dc33bd3SKees Cook		  malicious userspace programs can be identified.
23253dc33bd3SKees Cook
23263dc33bd3SKees Cookendchoice
23273dc33bd3SKees Cook
2328516cbf37STim Birdconfig CMDLINE_BOOL
2329516cbf37STim Bird	bool "Built-in kernel command line"
2330a7f7f624SMasahiro Yamada	help
2331516cbf37STim Bird	  Allow for specifying boot arguments to the kernel at
2332516cbf37STim Bird	  build time.  On some systems (e.g. embedded ones), it is
2333516cbf37STim Bird	  necessary or convenient to provide some or all of the
2334516cbf37STim Bird	  kernel boot arguments with the kernel itself (that is,
2335516cbf37STim Bird	  to not rely on the boot loader to provide them.)
2336516cbf37STim Bird
2337516cbf37STim Bird	  To compile command line arguments into the kernel,
2338516cbf37STim Bird	  set this option to 'Y', then fill in the
233969711ca1SSébastien Hinderer	  boot arguments in CONFIG_CMDLINE.
2340516cbf37STim Bird
2341516cbf37STim Bird	  Systems with fully functional boot loaders (i.e. non-embedded)
2342516cbf37STim Bird	  should leave this option set to 'N'.
2343516cbf37STim Bird
2344516cbf37STim Birdconfig CMDLINE
2345516cbf37STim Bird	string "Built-in kernel command string"
2346516cbf37STim Bird	depends on CMDLINE_BOOL
2347516cbf37STim Bird	default ""
2348a7f7f624SMasahiro Yamada	help
2349516cbf37STim Bird	  Enter arguments here that should be compiled into the kernel
2350516cbf37STim Bird	  image and used at boot time.  If the boot loader provides a
2351516cbf37STim Bird	  command line at boot time, it is appended to this string to
2352516cbf37STim Bird	  form the full kernel command line, when the system boots.
2353516cbf37STim Bird
2354516cbf37STim Bird	  However, you can use the CONFIG_CMDLINE_OVERRIDE option to
2355516cbf37STim Bird	  change this behavior.
2356516cbf37STim Bird
2357516cbf37STim Bird	  In most cases, the command line (whether built-in or provided
2358516cbf37STim Bird	  by the boot loader) should specify the device for the root
2359516cbf37STim Bird	  file system.
2360516cbf37STim Bird
2361516cbf37STim Birdconfig CMDLINE_OVERRIDE
2362516cbf37STim Bird	bool "Built-in command line overrides boot loader arguments"
2363645e6466SAnders Roxell	depends on CMDLINE_BOOL && CMDLINE != ""
2364a7f7f624SMasahiro Yamada	help
2365516cbf37STim Bird	  Set this option to 'Y' to have the kernel ignore the boot loader
2366516cbf37STim Bird	  command line, and use ONLY the built-in command line.
2367516cbf37STim Bird
2368516cbf37STim Bird	  This is used to work around broken boot loaders.  This should
2369516cbf37STim Bird	  be set to 'N' under normal conditions.
2370516cbf37STim Bird
2371a5b9e5a2SAndy Lutomirskiconfig MODIFY_LDT_SYSCALL
2372a5b9e5a2SAndy Lutomirski	bool "Enable the LDT (local descriptor table)" if EXPERT
2373a5b9e5a2SAndy Lutomirski	default y
2374a7f7f624SMasahiro Yamada	help
2375a5b9e5a2SAndy Lutomirski	  Linux can allow user programs to install a per-process x86
2376a5b9e5a2SAndy Lutomirski	  Local Descriptor Table (LDT) using the modify_ldt(2) system
2377a5b9e5a2SAndy Lutomirski	  call.  This is required to run 16-bit or segmented code such as
2378a5b9e5a2SAndy Lutomirski	  DOSEMU or some Wine programs.  It is also used by some very old
2379a5b9e5a2SAndy Lutomirski	  threading libraries.
2380a5b9e5a2SAndy Lutomirski
2381a5b9e5a2SAndy Lutomirski	  Enabling this feature adds a small amount of overhead to
2382a5b9e5a2SAndy Lutomirski	  context switches and increases the low-level kernel attack
2383a5b9e5a2SAndy Lutomirski	  surface.  Disabling it removes the modify_ldt(2) system call.
2384a5b9e5a2SAndy Lutomirski
2385a5b9e5a2SAndy Lutomirski	  Saying 'N' here may make sense for embedded or server kernels.
2386a5b9e5a2SAndy Lutomirski
23873aac3ebeSThomas Gleixnerconfig STRICT_SIGALTSTACK_SIZE
23883aac3ebeSThomas Gleixner	bool "Enforce strict size checking for sigaltstack"
23893aac3ebeSThomas Gleixner	depends on DYNAMIC_SIGFRAME
23903aac3ebeSThomas Gleixner	help
23913aac3ebeSThomas Gleixner	  For historical reasons MINSIGSTKSZ is a constant which became
23923aac3ebeSThomas Gleixner	  already too small with AVX512 support. Add a mechanism to
23933aac3ebeSThomas Gleixner	  enforce strict checking of the sigaltstack size against the
23943aac3ebeSThomas Gleixner	  real size of the FPU frame. This option enables the check
23953aac3ebeSThomas Gleixner	  by default. It can also be controlled via the kernel command
23963aac3ebeSThomas Gleixner	  line option 'strict_sas_size' independent of this config
23973aac3ebeSThomas Gleixner	  switch. Enabling it might break existing applications which
23983aac3ebeSThomas Gleixner	  allocate a too small sigaltstack but 'work' because they
23993aac3ebeSThomas Gleixner	  never get a signal delivered.
24003aac3ebeSThomas Gleixner
24013aac3ebeSThomas Gleixner	  Say 'N' unless you want to really enforce this check.
24023aac3ebeSThomas Gleixner
2403b700e7f0SSeth Jenningssource "kernel/livepatch/Kconfig"
2404b700e7f0SSeth Jennings
2405506f1d07SSam Ravnborgendmenu
2406506f1d07SSam Ravnborg
2407f43b9876SPeter Zijlstraconfig CC_HAS_SLS
2408f43b9876SPeter Zijlstra	def_bool $(cc-option,-mharden-sls=all)
2409f43b9876SPeter Zijlstra
2410f43b9876SPeter Zijlstraconfig CC_HAS_RETURN_THUNK
2411f43b9876SPeter Zijlstra	def_bool $(cc-option,-mfunction-return=thunk-extern)
2412f43b9876SPeter Zijlstra
2413bea75b33SThomas Gleixnerconfig CC_HAS_ENTRY_PADDING
2414bea75b33SThomas Gleixner	def_bool $(cc-option,-fpatchable-function-entry=16,16)
2415bea75b33SThomas Gleixner
2416bea75b33SThomas Gleixnerconfig FUNCTION_PADDING_CFI
2417bea75b33SThomas Gleixner	int
2418bea75b33SThomas Gleixner	default 59 if FUNCTION_ALIGNMENT_64B
2419bea75b33SThomas Gleixner	default 27 if FUNCTION_ALIGNMENT_32B
2420bea75b33SThomas Gleixner	default 11 if FUNCTION_ALIGNMENT_16B
2421bea75b33SThomas Gleixner	default  3 if FUNCTION_ALIGNMENT_8B
2422bea75b33SThomas Gleixner	default  0
2423bea75b33SThomas Gleixner
2424bea75b33SThomas Gleixner# Basically: FUNCTION_ALIGNMENT - 5*CFI_CLANG
2425bea75b33SThomas Gleixner# except Kconfig can't do arithmetic :/
2426bea75b33SThomas Gleixnerconfig FUNCTION_PADDING_BYTES
2427bea75b33SThomas Gleixner	int
2428bea75b33SThomas Gleixner	default FUNCTION_PADDING_CFI if CFI_CLANG
2429bea75b33SThomas Gleixner	default FUNCTION_ALIGNMENT
2430bea75b33SThomas Gleixner
2431931ab636SPeter Zijlstraconfig CALL_PADDING
2432931ab636SPeter Zijlstra	def_bool n
2433931ab636SPeter Zijlstra	depends on CC_HAS_ENTRY_PADDING && OBJTOOL
2434931ab636SPeter Zijlstra	select FUNCTION_ALIGNMENT_16B
2435931ab636SPeter Zijlstra
2436931ab636SPeter Zijlstraconfig FINEIBT
2437931ab636SPeter Zijlstra	def_bool y
2438931ab636SPeter Zijlstra	depends on X86_KERNEL_IBT && CFI_CLANG && RETPOLINE
2439931ab636SPeter Zijlstra	select CALL_PADDING
2440931ab636SPeter Zijlstra
24418f7c0d8bSThomas Gleixnerconfig HAVE_CALL_THUNKS
24428f7c0d8bSThomas Gleixner	def_bool y
2443bea75b33SThomas Gleixner	depends on CC_HAS_ENTRY_PADDING && RETHUNK && OBJTOOL
24448f7c0d8bSThomas Gleixner
24458f7c0d8bSThomas Gleixnerconfig CALL_THUNKS
24468f7c0d8bSThomas Gleixner	def_bool n
2447931ab636SPeter Zijlstra	select CALL_PADDING
24488f7c0d8bSThomas Gleixner
2449b341b20dSPeter Zijlstraconfig PREFIX_SYMBOLS
2450b341b20dSPeter Zijlstra	def_bool y
2451931ab636SPeter Zijlstra	depends on CALL_PADDING && !CFI_CLANG
2452b341b20dSPeter Zijlstra
24538292f4f8SSean Christophersonmenuconfig CPU_MITIGATIONS
24548292f4f8SSean Christopherson	bool "Mitigations for CPU vulnerabilities"
2455f43b9876SPeter Zijlstra	default y
2456f43b9876SPeter Zijlstra	help
24578292f4f8SSean Christopherson	  Say Y here to enable options which enable mitigations for hardware
24588292f4f8SSean Christopherson	  vulnerabilities (usually related to speculative execution).
2459976b74faSSean Christopherson	  Mitigations can be disabled or restricted to SMT systems at runtime
2460976b74faSSean Christopherson	  via the "mitigations" kernel parameter.
2461f43b9876SPeter Zijlstra
2462976b74faSSean Christopherson	  If you say N, all mitigations will be disabled.  This CANNOT be
2463976b74faSSean Christopherson	  overridden at runtime.
2464976b74faSSean Christopherson
2465976b74faSSean Christopherson	  Say 'Y', unless you really know what you are doing.
2466f43b9876SPeter Zijlstra
24678292f4f8SSean Christophersonif CPU_MITIGATIONS
2468f43b9876SPeter Zijlstra
2469f43b9876SPeter Zijlstraconfig PAGE_TABLE_ISOLATION
2470f43b9876SPeter Zijlstra	bool "Remove the kernel mapping in user mode"
2471f43b9876SPeter Zijlstra	default y
2472f43b9876SPeter Zijlstra	depends on (X86_64 || X86_PAE)
2473f43b9876SPeter Zijlstra	help
2474f43b9876SPeter Zijlstra	  This feature reduces the number of hardware side channels by
2475f43b9876SPeter Zijlstra	  ensuring that the majority of kernel addresses are not mapped
2476f43b9876SPeter Zijlstra	  into userspace.
2477f43b9876SPeter Zijlstra
2478ff61f079SJonathan Corbet	  See Documentation/arch/x86/pti.rst for more details.
2479f43b9876SPeter Zijlstra
2480f43b9876SPeter Zijlstraconfig RETPOLINE
2481f43b9876SPeter Zijlstra	bool "Avoid speculative indirect branches in kernel"
2482f43b9876SPeter Zijlstra	select OBJTOOL if HAVE_OBJTOOL
2483f43b9876SPeter Zijlstra	default y
2484f43b9876SPeter Zijlstra	help
2485f43b9876SPeter Zijlstra	  Compile kernel with the retpoline compiler options to guard against
2486f43b9876SPeter Zijlstra	  kernel-to-user data leaks by avoiding speculative indirect
2487f43b9876SPeter Zijlstra	  branches. Requires a compiler with -mindirect-branch=thunk-extern
2488f43b9876SPeter Zijlstra	  support for full protection. The kernel may run slower.
2489f43b9876SPeter Zijlstra
2490f43b9876SPeter Zijlstraconfig RETHUNK
2491f43b9876SPeter Zijlstra	bool "Enable return-thunks"
2492f43b9876SPeter Zijlstra	depends on RETPOLINE && CC_HAS_RETURN_THUNK
2493f43b9876SPeter Zijlstra	select OBJTOOL if HAVE_OBJTOOL
2494b648ab48SBen Hutchings	default y if X86_64
2495f43b9876SPeter Zijlstra	help
2496f43b9876SPeter Zijlstra	  Compile the kernel with the return-thunks compiler option to guard
2497f43b9876SPeter Zijlstra	  against kernel-to-user data leaks by avoiding return speculation.
2498f43b9876SPeter Zijlstra	  Requires a compiler with -mfunction-return=thunk-extern
2499f43b9876SPeter Zijlstra	  support for full protection. The kernel may run slower.
2500f43b9876SPeter Zijlstra
2501f43b9876SPeter Zijlstraconfig CPU_UNRET_ENTRY
2502f43b9876SPeter Zijlstra	bool "Enable UNRET on kernel entry"
2503b648ab48SBen Hutchings	depends on CPU_SUP_AMD && RETHUNK && X86_64
2504f43b9876SPeter Zijlstra	default y
2505f43b9876SPeter Zijlstra	help
2506f43b9876SPeter Zijlstra	  Compile the kernel with support for the retbleed=unret mitigation.
2507f43b9876SPeter Zijlstra
250880e4c1cdSThomas Gleixnerconfig CALL_DEPTH_TRACKING
250980e4c1cdSThomas Gleixner	bool "Mitigate RSB underflow with call depth tracking"
251080e4c1cdSThomas Gleixner	depends on CPU_SUP_INTEL && HAVE_CALL_THUNKS
251180e4c1cdSThomas Gleixner	select HAVE_DYNAMIC_FTRACE_NO_PATCHABLE
251280e4c1cdSThomas Gleixner	select CALL_THUNKS
251380e4c1cdSThomas Gleixner	default y
251480e4c1cdSThomas Gleixner	help
251580e4c1cdSThomas Gleixner	  Compile the kernel with call depth tracking to mitigate the Intel
251680e4c1cdSThomas Gleixner	  SKL Return-Speculation-Buffer (RSB) underflow issue. The
251780e4c1cdSThomas Gleixner	  mitigation is off by default and needs to be enabled on the
251880e4c1cdSThomas Gleixner	  kernel command line via the retbleed=stuff option. For
251980e4c1cdSThomas Gleixner	  non-affected systems the overhead of this option is marginal as
252080e4c1cdSThomas Gleixner	  the call depth tracking is using run-time generated call thunks
252180e4c1cdSThomas Gleixner	  in a compiler generated padding area and call patching. This
252280e4c1cdSThomas Gleixner	  increases text size by ~5%. For non affected systems this space
252380e4c1cdSThomas Gleixner	  is unused. On affected SKL systems this results in a significant
252480e4c1cdSThomas Gleixner	  performance gain over the IBRS mitigation.
252580e4c1cdSThomas Gleixner
2526e81dc127SThomas Gleixnerconfig CALL_THUNKS_DEBUG
2527e81dc127SThomas Gleixner	bool "Enable call thunks and call depth tracking debugging"
2528e81dc127SThomas Gleixner	depends on CALL_DEPTH_TRACKING
2529e81dc127SThomas Gleixner	select FUNCTION_ALIGNMENT_32B
2530e81dc127SThomas Gleixner	default n
2531e81dc127SThomas Gleixner	help
2532e81dc127SThomas Gleixner	  Enable call/ret counters for imbalance detection and build in
2533e81dc127SThomas Gleixner	  a noisy dmesg about callthunks generation and call patching for
2534e81dc127SThomas Gleixner	  trouble shooting. The debug prints need to be enabled on the
2535e81dc127SThomas Gleixner	  kernel command line with 'debug-callthunks'.
253654628de6SRandy Dunlap	  Only enable this when you are debugging call thunks as this
253754628de6SRandy Dunlap	  creates a noticeable runtime overhead. If unsure say N.
253880e4c1cdSThomas Gleixner
2539f43b9876SPeter Zijlstraconfig CPU_IBPB_ENTRY
2540f43b9876SPeter Zijlstra	bool "Enable IBPB on kernel entry"
2541b648ab48SBen Hutchings	depends on CPU_SUP_AMD && X86_64
2542f43b9876SPeter Zijlstra	default y
2543f43b9876SPeter Zijlstra	help
254460ba9b8aSPatrick Bellasi	  Compile the kernel with support for the retbleed=ibpb and
254560ba9b8aSPatrick Bellasi	  spec_rstack_overflow={ibpb,ibpb-vmexit} mitigations.
2546f43b9876SPeter Zijlstra
2547f43b9876SPeter Zijlstraconfig CPU_IBRS_ENTRY
2548f43b9876SPeter Zijlstra	bool "Enable IBRS on kernel entry"
2549b648ab48SBen Hutchings	depends on CPU_SUP_INTEL && X86_64
2550f43b9876SPeter Zijlstra	default y
2551f43b9876SPeter Zijlstra	help
2552f43b9876SPeter Zijlstra	  Compile the kernel with support for the spectre_v2=ibrs mitigation.
2553f43b9876SPeter Zijlstra	  This mitigates both spectre_v2 and retbleed at great cost to
2554f43b9876SPeter Zijlstra	  performance.
2555f43b9876SPeter Zijlstra
2556fb3bd914SBorislav Petkov (AMD)config CPU_SRSO
2557fb3bd914SBorislav Petkov (AMD)	bool "Mitigate speculative RAS overflow on AMD"
2558fb3bd914SBorislav Petkov (AMD)	depends on CPU_SUP_AMD && X86_64 && RETHUNK
2559fb3bd914SBorislav Petkov (AMD)	default y
2560fb3bd914SBorislav Petkov (AMD)	help
2561fb3bd914SBorislav Petkov (AMD)	  Enable the SRSO mitigation needed on AMD Zen1-4 machines.
2562fb3bd914SBorislav Petkov (AMD)
2563f43b9876SPeter Zijlstraconfig SLS
2564f43b9876SPeter Zijlstra	bool "Mitigate Straight-Line-Speculation"
2565f43b9876SPeter Zijlstra	depends on CC_HAS_SLS && X86_64
2566f43b9876SPeter Zijlstra	select OBJTOOL if HAVE_OBJTOOL
2567f43b9876SPeter Zijlstra	default n
2568f43b9876SPeter Zijlstra	help
2569f43b9876SPeter Zijlstra	  Compile the kernel with straight-line-speculation options to guard
2570f43b9876SPeter Zijlstra	  against straight line speculation. The kernel image might be slightly
2571f43b9876SPeter Zijlstra	  larger.
2572f43b9876SPeter Zijlstra
257353cf5797SDaniel Sneddonconfig GDS_FORCE_MITIGATION
257453cf5797SDaniel Sneddon	bool "Force GDS Mitigation"
257553cf5797SDaniel Sneddon	depends on CPU_SUP_INTEL
257653cf5797SDaniel Sneddon	default n
257753cf5797SDaniel Sneddon	help
257853cf5797SDaniel Sneddon	  Gather Data Sampling (GDS) is a hardware vulnerability which allows
257953cf5797SDaniel Sneddon	  unprivileged speculative access to data which was previously stored in
258053cf5797SDaniel Sneddon	  vector registers.
258153cf5797SDaniel Sneddon
258253cf5797SDaniel Sneddon	  This option is equivalent to setting gather_data_sampling=force on the
258353cf5797SDaniel Sneddon	  command line. The microcode mitigation is used if present, otherwise
258453cf5797SDaniel Sneddon	  AVX is disabled as a mitigation. On affected systems that are missing
258553cf5797SDaniel Sneddon	  the microcode any userspace code that unconditionally uses AVX will
258653cf5797SDaniel Sneddon	  break with this option set.
258753cf5797SDaniel Sneddon
258853cf5797SDaniel Sneddon	  Setting this option on systems not vulnerable to GDS has no effect.
258953cf5797SDaniel Sneddon
259053cf5797SDaniel Sneddon	  If in doubt, say N.
259153cf5797SDaniel Sneddon
259277018fb9SPawan Guptaconfig MITIGATION_RFDS
259377018fb9SPawan Gupta	bool "RFDS Mitigation"
259477018fb9SPawan Gupta	depends on CPU_SUP_INTEL
259577018fb9SPawan Gupta	default y
259677018fb9SPawan Gupta	help
259777018fb9SPawan Gupta	  Enable mitigation for Register File Data Sampling (RFDS) by default.
259877018fb9SPawan Gupta	  RFDS is a hardware vulnerability which affects Intel Atom CPUs. It
259977018fb9SPawan Gupta	  allows unprivileged speculative access to stale data previously
260077018fb9SPawan Gupta	  stored in floating point, vector and integer registers.
260177018fb9SPawan Gupta	  See also <file:Documentation/admin-guide/hw-vuln/reg-file-data-sampling.rst>
260277018fb9SPawan Gupta
260309e6cbe9SJosh Poimboeufconfig MITIGATION_SPECTRE_BHI
260409e6cbe9SJosh Poimboeuf	bool "Mitigate Spectre-BHB (Branch History Injection)"
2605d414b401SPawan Gupta	depends on CPU_SUP_INTEL
260609e6cbe9SJosh Poimboeuf	default y
2607d414b401SPawan Gupta	help
2608d414b401SPawan Gupta	  Enable BHI mitigations. BHI attacks are a form of Spectre V2 attacks
2609d414b401SPawan Gupta	  where the branch history buffer is poisoned to speculatively steer
2610d414b401SPawan Gupta	  indirect branches.
2611d414b401SPawan Gupta	  See <file:Documentation/admin-guide/hw-vuln/spectre.rst>
2612d414b401SPawan Gupta
2613*c5a5d807SPawan Guptaconfig MITIGATION_ITS
2614*c5a5d807SPawan Gupta	bool "Enable Indirect Target Selection mitigation"
2615*c5a5d807SPawan Gupta	depends on CPU_SUP_INTEL && X86_64
2616*c5a5d807SPawan Gupta	depends on RETPOLINE && RETHUNK
2617*c5a5d807SPawan Gupta	default y
2618*c5a5d807SPawan Gupta	help
2619*c5a5d807SPawan Gupta	  Enable Indirect Target Selection (ITS) mitigation. ITS is a bug in
2620*c5a5d807SPawan Gupta	  BPU on some Intel CPUs that may allow Spectre V2 style attacks. If
2621*c5a5d807SPawan Gupta	  disabled, mitigation cannot be enabled via cmdline.
2622*c5a5d807SPawan Gupta	  See <file:Documentation/admin-guide/hw-vuln/indirect-target-selection.rst>
2623*c5a5d807SPawan Gupta
2624f43b9876SPeter Zijlstraendif
2625f43b9876SPeter Zijlstra
26263072e413SMichal Hockoconfig ARCH_HAS_ADD_PAGES
26273072e413SMichal Hocko	def_bool y
26285c11f00bSDavid Hildenbrand	depends on ARCH_ENABLE_MEMORY_HOTPLUG
26293072e413SMichal Hocko
2630da85f865SBjorn Helgaasmenu "Power management and ACPI options"
2631e279b6c1SSam Ravnborg
2632e279b6c1SSam Ravnborgconfig ARCH_HIBERNATION_HEADER
26333c2362e6SHarvey Harrison	def_bool y
263444556530SZhimin Gu	depends on HIBERNATION
2635e279b6c1SSam Ravnborg
2636e279b6c1SSam Ravnborgsource "kernel/power/Kconfig"
2637e279b6c1SSam Ravnborg
2638e279b6c1SSam Ravnborgsource "drivers/acpi/Kconfig"
2639e279b6c1SSam Ravnborg
2640a6b68076SAndi Kleenconfig X86_APM_BOOT
26416fc108a0SJan Beulich	def_bool y
2642282e5aabSPaul Bolle	depends on APM
2643a6b68076SAndi Kleen
2644e279b6c1SSam Ravnborgmenuconfig APM
2645e279b6c1SSam Ravnborg	tristate "APM (Advanced Power Management) BIOS support"
2646efefa6f6SIngo Molnar	depends on X86_32 && PM_SLEEP
2647a7f7f624SMasahiro Yamada	help
2648e279b6c1SSam Ravnborg	  APM is a BIOS specification for saving power using several different
2649e279b6c1SSam Ravnborg	  techniques. This is mostly useful for battery powered laptops with
2650e279b6c1SSam Ravnborg	  APM compliant BIOSes. If you say Y here, the system time will be
2651e279b6c1SSam Ravnborg	  reset after a RESUME operation, the /proc/apm device will provide
2652e279b6c1SSam Ravnborg	  battery status information, and user-space programs will receive
2653e279b6c1SSam Ravnborg	  notification of APM "events" (e.g. battery status change).
2654e279b6c1SSam Ravnborg
2655e279b6c1SSam Ravnborg	  If you select "Y" here, you can disable actual use of the APM
2656e279b6c1SSam Ravnborg	  BIOS by passing the "apm=off" option to the kernel at boot time.
2657e279b6c1SSam Ravnborg
2658e279b6c1SSam Ravnborg	  Note that the APM support is almost completely disabled for
2659e279b6c1SSam Ravnborg	  machines with more than one CPU.
2660e279b6c1SSam Ravnborg
2661e279b6c1SSam Ravnborg	  In order to use APM, you will need supporting software. For location
2662151f4e2bSMauro Carvalho Chehab	  and more information, read <file:Documentation/power/apm-acpi.rst>
26632dc98fd3SMichael Witten	  and the Battery Powered Linux mini-HOWTO, available from
2664e279b6c1SSam Ravnborg	  <http://www.tldp.org/docs.html#howto>.
2665e279b6c1SSam Ravnborg
2666e279b6c1SSam Ravnborg	  This driver does not spin down disk drives (see the hdparm(8)
2667e279b6c1SSam Ravnborg	  manpage ("man 8 hdparm") for that), and it doesn't turn off
2668e279b6c1SSam Ravnborg	  VESA-compliant "green" monitors.
2669e279b6c1SSam Ravnborg
2670e279b6c1SSam Ravnborg	  This driver does not support the TI 4000M TravelMate and the ACER
2671e279b6c1SSam Ravnborg	  486/DX4/75 because they don't have compliant BIOSes. Many "green"
2672e279b6c1SSam Ravnborg	  desktop machines also don't have compliant BIOSes, and this driver
2673e279b6c1SSam Ravnborg	  may cause those machines to panic during the boot phase.
2674e279b6c1SSam Ravnborg
2675e279b6c1SSam Ravnborg	  Generally, if you don't have a battery in your machine, there isn't
2676e279b6c1SSam Ravnborg	  much point in using this driver and you should say N. If you get
2677e279b6c1SSam Ravnborg	  random kernel OOPSes or reboots that don't seem to be related to
2678e279b6c1SSam Ravnborg	  anything, try disabling/enabling this option (or disabling/enabling
2679e279b6c1SSam Ravnborg	  APM in your BIOS).
2680e279b6c1SSam Ravnborg
2681e279b6c1SSam Ravnborg	  Some other things you should try when experiencing seemingly random,
2682e279b6c1SSam Ravnborg	  "weird" problems:
2683e279b6c1SSam Ravnborg
2684e279b6c1SSam Ravnborg	  1) make sure that you have enough swap space and that it is
2685e279b6c1SSam Ravnborg	  enabled.
26867987448fSStephen Kitt	  2) pass the "idle=poll" option to the kernel
2687e279b6c1SSam Ravnborg	  3) switch on floating point emulation in the kernel and pass
2688e279b6c1SSam Ravnborg	  the "no387" option to the kernel
2689e279b6c1SSam Ravnborg	  4) pass the "floppy=nodma" option to the kernel
2690e279b6c1SSam Ravnborg	  5) pass the "mem=4M" option to the kernel (thereby disabling
2691e279b6c1SSam Ravnborg	  all but the first 4 MB of RAM)
2692e279b6c1SSam Ravnborg	  6) make sure that the CPU is not over clocked.
2693e279b6c1SSam Ravnborg	  7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/>
2694e279b6c1SSam Ravnborg	  8) disable the cache from your BIOS settings
2695e279b6c1SSam Ravnborg	  9) install a fan for the video card or exchange video RAM
2696e279b6c1SSam Ravnborg	  10) install a better fan for the CPU
2697e279b6c1SSam Ravnborg	  11) exchange RAM chips
2698e279b6c1SSam Ravnborg	  12) exchange the motherboard.
2699e279b6c1SSam Ravnborg
2700e279b6c1SSam Ravnborg	  To compile this driver as a module, choose M here: the
2701e279b6c1SSam Ravnborg	  module will be called apm.
2702e279b6c1SSam Ravnborg
2703e279b6c1SSam Ravnborgif APM
2704e279b6c1SSam Ravnborg
2705e279b6c1SSam Ravnborgconfig APM_IGNORE_USER_SUSPEND
2706e279b6c1SSam Ravnborg	bool "Ignore USER SUSPEND"
2707a7f7f624SMasahiro Yamada	help
2708e279b6c1SSam Ravnborg	  This option will ignore USER SUSPEND requests. On machines with a
2709e279b6c1SSam Ravnborg	  compliant APM BIOS, you want to say N. However, on the NEC Versa M
2710e279b6c1SSam Ravnborg	  series notebooks, it is necessary to say Y because of a BIOS bug.
2711e279b6c1SSam Ravnborg
2712e279b6c1SSam Ravnborgconfig APM_DO_ENABLE
2713e279b6c1SSam Ravnborg	bool "Enable PM at boot time"
2714a7f7f624SMasahiro Yamada	help
2715e279b6c1SSam Ravnborg	  Enable APM features at boot time. From page 36 of the APM BIOS
2716e279b6c1SSam Ravnborg	  specification: "When disabled, the APM BIOS does not automatically
2717e279b6c1SSam Ravnborg	  power manage devices, enter the Standby State, enter the Suspend
2718e279b6c1SSam Ravnborg	  State, or take power saving steps in response to CPU Idle calls."
2719e279b6c1SSam Ravnborg	  This driver will make CPU Idle calls when Linux is idle (unless this
2720e279b6c1SSam Ravnborg	  feature is turned off -- see "Do CPU IDLE calls", below). This
2721e279b6c1SSam Ravnborg	  should always save battery power, but more complicated APM features
2722e279b6c1SSam Ravnborg	  will be dependent on your BIOS implementation. You may need to turn
2723e279b6c1SSam Ravnborg	  this option off if your computer hangs at boot time when using APM
2724e279b6c1SSam Ravnborg	  support, or if it beeps continuously instead of suspending. Turn
2725e279b6c1SSam Ravnborg	  this off if you have a NEC UltraLite Versa 33/C or a Toshiba
2726e279b6c1SSam Ravnborg	  T400CDT. This is off by default since most machines do fine without
2727e279b6c1SSam Ravnborg	  this feature.
2728e279b6c1SSam Ravnborg
2729e279b6c1SSam Ravnborgconfig APM_CPU_IDLE
2730dd8af076SLen Brown	depends on CPU_IDLE
2731e279b6c1SSam Ravnborg	bool "Make CPU Idle calls when idle"
2732a7f7f624SMasahiro Yamada	help
2733e279b6c1SSam Ravnborg	  Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop.
2734e279b6c1SSam Ravnborg	  On some machines, this can activate improved power savings, such as
2735e279b6c1SSam Ravnborg	  a slowed CPU clock rate, when the machine is idle. These idle calls
2736e279b6c1SSam Ravnborg	  are made after the idle loop has run for some length of time (e.g.,
2737e279b6c1SSam Ravnborg	  333 mS). On some machines, this will cause a hang at boot time or
2738e279b6c1SSam Ravnborg	  whenever the CPU becomes idle. (On machines with more than one CPU,
2739e279b6c1SSam Ravnborg	  this option does nothing.)
2740e279b6c1SSam Ravnborg
2741e279b6c1SSam Ravnborgconfig APM_DISPLAY_BLANK
2742e279b6c1SSam Ravnborg	bool "Enable console blanking using APM"
2743a7f7f624SMasahiro Yamada	help
2744e279b6c1SSam Ravnborg	  Enable console blanking using the APM. Some laptops can use this to
2745e279b6c1SSam Ravnborg	  turn off the LCD backlight when the screen blanker of the Linux
2746e279b6c1SSam Ravnborg	  virtual console blanks the screen. Note that this is only used by
2747e279b6c1SSam Ravnborg	  the virtual console screen blanker, and won't turn off the backlight
2748e279b6c1SSam Ravnborg	  when using the X Window system. This also doesn't have anything to
2749e279b6c1SSam Ravnborg	  do with your VESA-compliant power-saving monitor. Further, this
2750e279b6c1SSam Ravnborg	  option doesn't work for all laptops -- it might not turn off your
2751e279b6c1SSam Ravnborg	  backlight at all, or it might print a lot of errors to the console,
2752e279b6c1SSam Ravnborg	  especially if you are using gpm.
2753e279b6c1SSam Ravnborg
2754e279b6c1SSam Ravnborgconfig APM_ALLOW_INTS
2755e279b6c1SSam Ravnborg	bool "Allow interrupts during APM BIOS calls"
2756a7f7f624SMasahiro Yamada	help
2757e279b6c1SSam Ravnborg	  Normally we disable external interrupts while we are making calls to
2758e279b6c1SSam Ravnborg	  the APM BIOS as a measure to lessen the effects of a badly behaving
2759e279b6c1SSam Ravnborg	  BIOS implementation.  The BIOS should reenable interrupts if it
2760e279b6c1SSam Ravnborg	  needs to.  Unfortunately, some BIOSes do not -- especially those in
2761e279b6c1SSam Ravnborg	  many of the newer IBM Thinkpads.  If you experience hangs when you
2762e279b6c1SSam Ravnborg	  suspend, try setting this to Y.  Otherwise, say N.
2763e279b6c1SSam Ravnborg
2764e279b6c1SSam Ravnborgendif # APM
2765e279b6c1SSam Ravnborg
2766bb0a56ecSDave Jonessource "drivers/cpufreq/Kconfig"
2767e279b6c1SSam Ravnborg
2768e279b6c1SSam Ravnborgsource "drivers/cpuidle/Kconfig"
2769e279b6c1SSam Ravnborg
277027471fdbSAndy Henroidsource "drivers/idle/Kconfig"
277127471fdbSAndy Henroid
2772e279b6c1SSam Ravnborgendmenu
2773e279b6c1SSam Ravnborg
2774e279b6c1SSam Ravnborgmenu "Bus options (PCI etc.)"
2775e279b6c1SSam Ravnborg
2776e279b6c1SSam Ravnborgchoice
2777e279b6c1SSam Ravnborg	prompt "PCI access mode"
2778efefa6f6SIngo Molnar	depends on X86_32 && PCI
2779e279b6c1SSam Ravnborg	default PCI_GOANY
2780a7f7f624SMasahiro Yamada	help
2781e279b6c1SSam Ravnborg	  On PCI systems, the BIOS can be used to detect the PCI devices and
2782e279b6c1SSam Ravnborg	  determine their configuration. However, some old PCI motherboards
2783e279b6c1SSam Ravnborg	  have BIOS bugs and may crash if this is done. Also, some embedded
2784e279b6c1SSam Ravnborg	  PCI-based systems don't have any BIOS at all. Linux can also try to
2785e279b6c1SSam Ravnborg	  detect the PCI hardware directly without using the BIOS.
2786e279b6c1SSam Ravnborg
2787e279b6c1SSam Ravnborg	  With this option, you can specify how Linux should detect the
2788e279b6c1SSam Ravnborg	  PCI devices. If you choose "BIOS", the BIOS will be used,
2789e279b6c1SSam Ravnborg	  if you choose "Direct", the BIOS won't be used, and if you
2790e279b6c1SSam Ravnborg	  choose "MMConfig", then PCI Express MMCONFIG will be used.
2791e279b6c1SSam Ravnborg	  If you choose "Any", the kernel will try MMCONFIG, then the
2792e279b6c1SSam Ravnborg	  direct access method and falls back to the BIOS if that doesn't
2793e279b6c1SSam Ravnborg	  work. If unsure, go with the default, which is "Any".
2794e279b6c1SSam Ravnborg
2795e279b6c1SSam Ravnborgconfig PCI_GOBIOS
2796e279b6c1SSam Ravnborg	bool "BIOS"
2797e279b6c1SSam Ravnborg
2798e279b6c1SSam Ravnborgconfig PCI_GOMMCONFIG
2799e279b6c1SSam Ravnborg	bool "MMConfig"
2800e279b6c1SSam Ravnborg
2801e279b6c1SSam Ravnborgconfig PCI_GODIRECT
2802e279b6c1SSam Ravnborg	bool "Direct"
2803e279b6c1SSam Ravnborg
28043ef0e1f8SAndres Salomonconfig PCI_GOOLPC
280576fb6570SDaniel Drake	bool "OLPC XO-1"
28063ef0e1f8SAndres Salomon	depends on OLPC
28073ef0e1f8SAndres Salomon
28082bdd1b03SAndres Salomonconfig PCI_GOANY
28092bdd1b03SAndres Salomon	bool "Any"
28102bdd1b03SAndres Salomon
2811e279b6c1SSam Ravnborgendchoice
2812e279b6c1SSam Ravnborg
2813e279b6c1SSam Ravnborgconfig PCI_BIOS
28143c2362e6SHarvey Harrison	def_bool y
2815efefa6f6SIngo Molnar	depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY)
2816e279b6c1SSam Ravnborg
2817e279b6c1SSam Ravnborg# x86-64 doesn't support PCI BIOS access from long mode so always go direct.
2818e279b6c1SSam Ravnborgconfig PCI_DIRECT
28193c2362e6SHarvey Harrison	def_bool y
28200aba496fSShaohua Li	depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC || PCI_GOMMCONFIG))
2821e279b6c1SSam Ravnborg
2822e279b6c1SSam Ravnborgconfig PCI_MMCONFIG
2823b45c9f36SJan Kiszka	bool "Support mmconfig PCI config space access" if X86_64
2824b45c9f36SJan Kiszka	default y
28254590d98fSAndy Shevchenko	depends on PCI && (ACPI || JAILHOUSE_GUEST)
2826b45c9f36SJan Kiszka	depends on X86_64 || (PCI_GOANY || PCI_GOMMCONFIG)
2827e279b6c1SSam Ravnborg
28283ef0e1f8SAndres Salomonconfig PCI_OLPC
28292bdd1b03SAndres Salomon	def_bool y
28302bdd1b03SAndres Salomon	depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY)
28313ef0e1f8SAndres Salomon
2832b5401a96SAlex Nixonconfig PCI_XEN
2833b5401a96SAlex Nixon	def_bool y
2834b5401a96SAlex Nixon	depends on PCI && XEN
2835b5401a96SAlex Nixon
28368364e1f8SJan Kiszkaconfig MMCONF_FAM10H
28378364e1f8SJan Kiszka	def_bool y
28388364e1f8SJan Kiszka	depends on X86_64 && PCI_MMCONFIG && ACPI
2839e279b6c1SSam Ravnborg
28403f6ea84aSIra W. Snyderconfig PCI_CNB20LE_QUIRK
28416a108a14SDavid Rientjes	bool "Read CNB20LE Host Bridge Windows" if EXPERT
28426ea30386SKees Cook	depends on PCI
28433f6ea84aSIra W. Snyder	help
28443f6ea84aSIra W. Snyder	  Read the PCI windows out of the CNB20LE host bridge. This allows
28453f6ea84aSIra W. Snyder	  PCI hotplug to work on systems with the CNB20LE chipset which do
28463f6ea84aSIra W. Snyder	  not have ACPI.
28473f6ea84aSIra W. Snyder
284864a5fed6SBjorn Helgaas	  There's no public spec for this chipset, and this functionality
284964a5fed6SBjorn Helgaas	  is known to be incomplete.
285064a5fed6SBjorn Helgaas
285164a5fed6SBjorn Helgaas	  You should say N unless you know you need this.
285264a5fed6SBjorn Helgaas
28533a495511SWilliam Breathitt Grayconfig ISA_BUS
285417a2a129SWilliam Breathitt Gray	bool "ISA bus support on modern systems" if EXPERT
28553a495511SWilliam Breathitt Gray	help
285617a2a129SWilliam Breathitt Gray	  Expose ISA bus device drivers and options available for selection and
285717a2a129SWilliam Breathitt Gray	  configuration. Enable this option if your target machine has an ISA
285817a2a129SWilliam Breathitt Gray	  bus. ISA is an older system, displaced by PCI and newer bus
285917a2a129SWilliam Breathitt Gray	  architectures -- if your target machine is modern, it probably does
286017a2a129SWilliam Breathitt Gray	  not have an ISA bus.
28613a495511SWilliam Breathitt Gray
28623a495511SWilliam Breathitt Gray	  If unsure, say N.
28633a495511SWilliam Breathitt Gray
28641c00f016SDavid Rientjes# x86_64 have no ISA slots, but can have ISA-style DMA.
2865e279b6c1SSam Ravnborgconfig ISA_DMA_API
28661c00f016SDavid Rientjes	bool "ISA-style DMA support" if (X86_64 && EXPERT)
28671c00f016SDavid Rientjes	default y
28681c00f016SDavid Rientjes	help
28691c00f016SDavid Rientjes	  Enables ISA-style DMA support for devices requiring such controllers.
28701c00f016SDavid Rientjes	  If unsure, say Y.
2871e279b6c1SSam Ravnborg
287251e68d05SLinus Torvaldsif X86_32
287351e68d05SLinus Torvalds
2874e279b6c1SSam Ravnborgconfig ISA
2875e279b6c1SSam Ravnborg	bool "ISA support"
2876a7f7f624SMasahiro Yamada	help
2877e279b6c1SSam Ravnborg	  Find out whether you have ISA slots on your motherboard.  ISA is the
2878e279b6c1SSam Ravnborg	  name of a bus system, i.e. the way the CPU talks to the other stuff
2879e279b6c1SSam Ravnborg	  inside your box.  Other bus systems are PCI, EISA, MicroChannel
2880e279b6c1SSam Ravnborg	  (MCA) or VESA.  ISA is an older system, now being displaced by PCI;
2881e279b6c1SSam Ravnborg	  newer boards don't support it.  If you have ISA, say Y, otherwise N.
2882e279b6c1SSam Ravnborg
2883e279b6c1SSam Ravnborgconfig SCx200
2884e279b6c1SSam Ravnborg	tristate "NatSemi SCx200 support"
2885a7f7f624SMasahiro Yamada	help
2886e279b6c1SSam Ravnborg	  This provides basic support for National Semiconductor's
2887e279b6c1SSam Ravnborg	  (now AMD's) Geode processors.  The driver probes for the
2888e279b6c1SSam Ravnborg	  PCI-IDs of several on-chip devices, so its a good dependency
2889e279b6c1SSam Ravnborg	  for other scx200_* drivers.
2890e279b6c1SSam Ravnborg
2891e279b6c1SSam Ravnborg	  If compiled as a module, the driver is named scx200.
2892e279b6c1SSam Ravnborg
2893e279b6c1SSam Ravnborgconfig SCx200HR_TIMER
2894e279b6c1SSam Ravnborg	tristate "NatSemi SCx200 27MHz High-Resolution Timer Support"
2895592913ecSJohn Stultz	depends on SCx200
2896e279b6c1SSam Ravnborg	default y
2897a7f7f624SMasahiro Yamada	help
2898e279b6c1SSam Ravnborg	  This driver provides a clocksource built upon the on-chip
2899e279b6c1SSam Ravnborg	  27MHz high-resolution timer.  Its also a workaround for
2900e279b6c1SSam Ravnborg	  NSC Geode SC-1100's buggy TSC, which loses time when the
2901e279b6c1SSam Ravnborg	  processor goes idle (as is done by the scheduler).  The
2902e279b6c1SSam Ravnborg	  other workaround is idle=poll boot option.
2903e279b6c1SSam Ravnborg
29043ef0e1f8SAndres Salomonconfig OLPC
29053ef0e1f8SAndres Salomon	bool "One Laptop Per Child support"
290654008979SThomas Gleixner	depends on !X86_PAE
29073c554946SAndres Salomon	select GPIOLIB
2908dc3119e7SThomas Gleixner	select OF
290945bb1674SDaniel Drake	select OF_PROMTREE
2910b4e51854SGrant Likely	select IRQ_DOMAIN
29110c3d931bSLubomir Rintel	select OLPC_EC
2912a7f7f624SMasahiro Yamada	help
29133ef0e1f8SAndres Salomon	  Add support for detecting the unique features of the OLPC
29143ef0e1f8SAndres Salomon	  XO hardware.
29153ef0e1f8SAndres Salomon
2916a3128588SDaniel Drakeconfig OLPC_XO1_PM
2917a3128588SDaniel Drake	bool "OLPC XO-1 Power Management"
2918fa112cf1SBorislav Petkov	depends on OLPC && MFD_CS5535=y && PM_SLEEP
2919a7f7f624SMasahiro Yamada	help
292097c4cb71SDaniel Drake	  Add support for poweroff and suspend of the OLPC XO-1 laptop.
2921bf1ebf00SDaniel Drake
2922cfee9597SDaniel Drakeconfig OLPC_XO1_RTC
2923cfee9597SDaniel Drake	bool "OLPC XO-1 Real Time Clock"
2924cfee9597SDaniel Drake	depends on OLPC_XO1_PM && RTC_DRV_CMOS
2925a7f7f624SMasahiro Yamada	help
2926cfee9597SDaniel Drake	  Add support for the XO-1 real time clock, which can be used as a
2927cfee9597SDaniel Drake	  programmable wakeup source.
2928cfee9597SDaniel Drake
29297feda8e9SDaniel Drakeconfig OLPC_XO1_SCI
29307feda8e9SDaniel Drake	bool "OLPC XO-1 SCI extras"
293192e830f2SArnd Bergmann	depends on OLPC && OLPC_XO1_PM && GPIO_CS5535=y
2932ed8e47feSRandy Dunlap	depends on INPUT=y
2933d8d01a63SDaniel Drake	select POWER_SUPPLY
2934a7f7f624SMasahiro Yamada	help
29357feda8e9SDaniel Drake	  Add support for SCI-based features of the OLPC XO-1 laptop:
29367bc74b3dSDaniel Drake	   - EC-driven system wakeups
29377feda8e9SDaniel Drake	   - Power button
29387bc74b3dSDaniel Drake	   - Ebook switch
29392cf2baeaSDaniel Drake	   - Lid switch
2940e1040ac6SDaniel Drake	   - AC adapter status updates
2941e1040ac6SDaniel Drake	   - Battery status updates
29427feda8e9SDaniel Drake
2943a0f30f59SDaniel Drakeconfig OLPC_XO15_SCI
2944a0f30f59SDaniel Drake	bool "OLPC XO-1.5 SCI extras"
2945d8d01a63SDaniel Drake	depends on OLPC && ACPI
2946d8d01a63SDaniel Drake	select POWER_SUPPLY
2947a7f7f624SMasahiro Yamada	help
2948a0f30f59SDaniel Drake	  Add support for SCI-based features of the OLPC XO-1.5 laptop:
2949a0f30f59SDaniel Drake	   - EC-driven system wakeups
2950a0f30f59SDaniel Drake	   - AC adapter status updates
2951a0f30f59SDaniel Drake	   - Battery status updates
2952e279b6c1SSam Ravnborg
2953d4f3e350SEd Wildgooseconfig ALIX
2954d4f3e350SEd Wildgoose	bool "PCEngines ALIX System Support (LED setup)"
2955d4f3e350SEd Wildgoose	select GPIOLIB
2956a7f7f624SMasahiro Yamada	help
2957d4f3e350SEd Wildgoose	  This option enables system support for the PCEngines ALIX.
2958d4f3e350SEd Wildgoose	  At present this just sets up LEDs for GPIO control on
2959d4f3e350SEd Wildgoose	  ALIX2/3/6 boards.  However, other system specific setup should
2960d4f3e350SEd Wildgoose	  get added here.
2961d4f3e350SEd Wildgoose
2962d4f3e350SEd Wildgoose	  Note: You must still enable the drivers for GPIO and LED support
2963d4f3e350SEd Wildgoose	  (GPIO_CS5535 & LEDS_GPIO) to actually use the LEDs
2964d4f3e350SEd Wildgoose
2965d4f3e350SEd Wildgoose	  Note: You have to set alix.force=1 for boards with Award BIOS.
2966d4f3e350SEd Wildgoose
2967da4e3302SPhilip Prindevilleconfig NET5501
2968da4e3302SPhilip Prindeville	bool "Soekris Engineering net5501 System Support (LEDS, GPIO, etc)"
2969da4e3302SPhilip Prindeville	select GPIOLIB
2970a7f7f624SMasahiro Yamada	help
2971da4e3302SPhilip Prindeville	  This option enables system support for the Soekris Engineering net5501.
2972da4e3302SPhilip Prindeville
29733197059aSPhilip A. Prindevilleconfig GEOS
29743197059aSPhilip A. Prindeville	bool "Traverse Technologies GEOS System Support (LEDS, GPIO, etc)"
29753197059aSPhilip A. Prindeville	select GPIOLIB
29763197059aSPhilip A. Prindeville	depends on DMI
2977a7f7f624SMasahiro Yamada	help
29783197059aSPhilip A. Prindeville	  This option enables system support for the Traverse Technologies GEOS.
29793197059aSPhilip A. Prindeville
29807d029125SVivien Didelotconfig TS5500
29817d029125SVivien Didelot	bool "Technologic Systems TS-5500 platform support"
29827d029125SVivien Didelot	depends on MELAN
29837d029125SVivien Didelot	select CHECK_SIGNATURE
29847d029125SVivien Didelot	select NEW_LEDS
29857d029125SVivien Didelot	select LEDS_CLASS
2986a7f7f624SMasahiro Yamada	help
29877d029125SVivien Didelot	  This option enables system support for the Technologic Systems TS-5500.
29887d029125SVivien Didelot
2989e279b6c1SSam Ravnborgendif # X86_32
2990e279b6c1SSam Ravnborg
299123ac4ae8SAndreas Herrmannconfig AMD_NB
2992e279b6c1SSam Ravnborg	def_bool y
29930e152cd7SBorislav Petkov	depends on CPU_SUP_AMD && PCI
2994e279b6c1SSam Ravnborg
2995e279b6c1SSam Ravnborgendmenu
2996e279b6c1SSam Ravnborg
29971572497cSChristoph Hellwigmenu "Binary Emulations"
2998e279b6c1SSam Ravnborg
2999e279b6c1SSam Ravnborgconfig IA32_EMULATION
3000e279b6c1SSam Ravnborg	bool "IA32 Emulation"
3001e279b6c1SSam Ravnborg	depends on X86_64
300239f88911SIngo Molnar	select ARCH_WANT_OLD_COMPAT_IPC
3003d1603990SRandy Dunlap	select BINFMT_ELF
300439f88911SIngo Molnar	select COMPAT_OLD_SIGACTION
3005a7f7f624SMasahiro Yamada	help
30065fd92e65SH. J. Lu	  Include code to run legacy 32-bit programs under a
30075fd92e65SH. J. Lu	  64-bit kernel. You should likely turn this on, unless you're
30085fd92e65SH. J. Lu	  100% sure that you don't have any 32-bit programs left.
3009e279b6c1SSam Ravnborg
301083a44a4fSMasahiro Yamadaconfig X86_X32_ABI
30116ea30386SKees Cook	bool "x32 ABI for 64-bit mode"
30129b54050bSBrian Gerst	depends on X86_64
3013aaeed6ecSNathan Chancellor	# llvm-objcopy does not convert x86_64 .note.gnu.property or
3014aaeed6ecSNathan Chancellor	# compressed debug sections to x86_x32 properly:
3015aaeed6ecSNathan Chancellor	# https://github.com/ClangBuiltLinux/linux/issues/514
3016aaeed6ecSNathan Chancellor	# https://github.com/ClangBuiltLinux/linux/issues/1141
3017aaeed6ecSNathan Chancellor	depends on $(success,$(OBJCOPY) --version | head -n1 | grep -qv llvm)
3018a7f7f624SMasahiro Yamada	help
30195fd92e65SH. J. Lu	  Include code to run binaries for the x32 native 32-bit ABI
30205fd92e65SH. J. Lu	  for 64-bit processors.  An x32 process gets access to the
30215fd92e65SH. J. Lu	  full 64-bit register file and wide data path while leaving
30225fd92e65SH. J. Lu	  pointers at 32 bits for smaller memory footprint.
30235fd92e65SH. J. Lu
3024953fee1dSIngo Molnarconfig COMPAT_32
3025953fee1dSIngo Molnar	def_bool y
3026953fee1dSIngo Molnar	depends on IA32_EMULATION || X86_32
3027953fee1dSIngo Molnar	select HAVE_UID16
3028953fee1dSIngo Molnar	select OLD_SIGSUSPEND3
3029953fee1dSIngo Molnar
3030e279b6c1SSam Ravnborgconfig COMPAT
30313c2362e6SHarvey Harrison	def_bool y
303283a44a4fSMasahiro Yamada	depends on IA32_EMULATION || X86_X32_ABI
3033e279b6c1SSam Ravnborg
3034e279b6c1SSam Ravnborgconfig COMPAT_FOR_U64_ALIGNMENT
30353120e25eSJan Beulich	def_bool y
3036a9251280SLinus Torvalds	depends on COMPAT
3037ee009e4aSDavid Howells
3038e279b6c1SSam Ravnborgendmenu
3039e279b6c1SSam Ravnborg
3040e5beae16SKeith Packardconfig HAVE_ATOMIC_IOMAP
3041e5beae16SKeith Packard	def_bool y
3042e5beae16SKeith Packard	depends on X86_32
3043e5beae16SKeith Packard
3044edf88417SAvi Kivitysource "arch/x86/kvm/Kconfig"
30455e8ebd84SJason A. Donenfeld
30465e8ebd84SJason A. Donenfeldsource "arch/x86/Kconfig.assembler"
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