xref: /linux/arch/x86/Kconfig (revision d49a0626216b95cd4bf696f6acf55f39a16ab0bb)
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
30d94e0685SIngo Molnar	select ARCH_USE_CMPXCHG_LOCKREF
31d94e0685SIngo Molnar	select HAVE_ARCH_SOFT_DIRTY
32d94e0685SIngo Molnar	select MODULES_USE_ELF_RELA
33f616ab59SChristoph Hellwig	select NEED_DMA_MAP_STATE
3409230cbcSChristoph Hellwig	select SWIOTLB
357facdc42SAl Viro	select ARCH_HAS_ELFCORE_COMPAT
3663703f37SKefeng Wang	select ZONE_DMA32
371032c0baSSam Ravnborg
38518049d9SSteven Rostedt (VMware)config FORCE_DYNAMIC_FTRACE
39518049d9SSteven Rostedt (VMware)	def_bool y
40518049d9SSteven Rostedt (VMware)	depends on X86_32
41518049d9SSteven Rostedt (VMware)	depends on FUNCTION_TRACER
42518049d9SSteven Rostedt (VMware)	select DYNAMIC_FTRACE
43518049d9SSteven Rostedt (VMware)	help
44518049d9SSteven Rostedt (VMware)	  We keep the static function tracing (!DYNAMIC_FTRACE) around
45518049d9SSteven Rostedt (VMware)	  in order to test the non static function tracing in the
46518049d9SSteven Rostedt (VMware)	  generic code, as other architectures still use it. But we
47518049d9SSteven Rostedt (VMware)	  only need to keep it around for x86_64. No need to keep it
48518049d9SSteven Rostedt (VMware)	  for x86_32. For x86_32, force DYNAMIC_FTRACE.
49d94e0685SIngo Molnar#
50d94e0685SIngo Molnar# Arch settings
51d94e0685SIngo Molnar#
52d94e0685SIngo Molnar# ( Note that options that are marked 'if X86_64' could in principle be
53d94e0685SIngo Molnar#   ported to 32-bit as well. )
54d94e0685SIngo Molnar#
558d5fffb9SSam Ravnborgconfig X86
563c2362e6SHarvey Harrison	def_bool y
57c763ea26SIngo Molnar	#
58c763ea26SIngo Molnar	# Note: keep this list sorted alphabetically
59c763ea26SIngo Molnar	#
606471b825SIngo Molnar	select ACPI_LEGACY_TABLES_LOOKUP	if ACPI
616e0a0ea1SGraeme Gregory	select ACPI_SYSTEM_POWER_STATES_SUPPORT	if ACPI
62942fa985SYury Norov	select ARCH_32BIT_OFF_T			if X86_32
632a21ad57SThomas Gleixner	select ARCH_CLOCKSOURCE_INIT
641f6d3a8fSMasami Hiramatsu	select ARCH_CORRECT_STACKTRACE_ON_KRETPROBE
651e866974SAnshuman Khandual	select ARCH_ENABLE_HUGEPAGE_MIGRATION if X86_64 && HUGETLB_PAGE && MIGRATION
665c11f00bSDavid Hildenbrand	select ARCH_ENABLE_MEMORY_HOTPLUG if X86_64
6791024b3cSAnshuman Khandual	select ARCH_ENABLE_MEMORY_HOTREMOVE if MEMORY_HOTPLUG
68cebc774fSAnshuman Khandual	select ARCH_ENABLE_SPLIT_PMD_PTLOCK if (PGTABLE_LEVELS > 2) && (X86_64 || X86_PAE)
691e866974SAnshuman Khandual	select ARCH_ENABLE_THP_MIGRATION if X86_64 && TRANSPARENT_HUGEPAGE
7091dda51aSAleksey Makarov	select ARCH_HAS_ACPI_TABLE_UPGRADE	if ACPI
71c2280be8SAnshuman Khandual	select ARCH_HAS_CACHE_LINE_SIZE
722792d84eSKees Cook	select ARCH_HAS_CURRENT_STACK_POINTER
73fa5b6ec9SLaura Abbott	select ARCH_HAS_DEBUG_VIRTUAL
74399145f9SAnshuman Khandual	select ARCH_HAS_DEBUG_VM_PGTABLE	if !X86_PAE
7521266be9SDan Williams	select ARCH_HAS_DEVMEM_IS_ALLOWED
76b1a57bbfSDouglas Anderson	select ARCH_HAS_EARLY_DEBUG		if KGDB
776471b825SIngo Molnar	select ARCH_HAS_ELF_RANDOMIZE
7872d93104SLinus Torvalds	select ARCH_HAS_FAST_MULTIPLIER
796974f0c4SDaniel Micay	select ARCH_HAS_FORTIFY_SOURCE
80957e3facSRiku Voipio	select ARCH_HAS_GCOV_PROFILE_ALL
81bece04b5SMarco Elver	select ARCH_HAS_KCOV			if X86_64
820c9c1d56SThiago Jung Bauermann	select ARCH_HAS_MEM_ENCRYPT
8310bcc80eSMathieu Desnoyers	select ARCH_HAS_MEMBARRIER_SYNC_CORE
840ebeea8cSDaniel Borkmann	select ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE
85c763ea26SIngo Molnar	select ARCH_HAS_PMEM_API		if X86_64
8617596731SRobin Murphy	select ARCH_HAS_PTE_DEVMAP		if X86_64
873010a5eaSLaurent Dufour	select ARCH_HAS_PTE_SPECIAL
88eed9a328SYu Zhao	select ARCH_HAS_NONLEAF_PMD_YOUNG	if PGTABLE_LEVELS > 2
890aed55afSDan Williams	select ARCH_HAS_UACCESS_FLUSHCACHE	if X86_64
90ec6347bbSDan Williams	select ARCH_HAS_COPY_MC			if X86_64
91d2852a22SDaniel Borkmann	select ARCH_HAS_SET_MEMORY
92d253ca0cSRick Edgecombe	select ARCH_HAS_SET_DIRECT_MAP
93ad21fc4fSLaura Abbott	select ARCH_HAS_STRICT_KERNEL_RWX
94ad21fc4fSLaura Abbott	select ARCH_HAS_STRICT_MODULE_RWX
95ac1ab12aSMathieu Desnoyers	select ARCH_HAS_SYNC_CORE_BEFORE_USERMODE
9625c619e5SBrian Gerst	select ARCH_HAS_SYSCALL_WRAPPER
97c6d30853SAndrey Ryabinin	select ARCH_HAS_UBSAN_SANITIZE_ALL
987e01ccb4SZong Li	select ARCH_HAS_DEBUG_WX
9963703f37SKefeng Wang	select ARCH_HAS_ZONE_DMA_SET if EXPERT
1006471b825SIngo Molnar	select ARCH_HAVE_NMI_SAFE_CMPXCHG
1016471b825SIngo Molnar	select ARCH_MIGHT_HAVE_ACPI_PDC		if ACPI
10277fbbc81SMark Salter	select ARCH_MIGHT_HAVE_PC_PARPORT
1035e2c18c0SMark Salter	select ARCH_MIGHT_HAVE_PC_SERIO
1043599fe12SThomas Gleixner	select ARCH_STACKWALK
1052c870e61SArnd Bergmann	select ARCH_SUPPORTS_ACPI
1066471b825SIngo Molnar	select ARCH_SUPPORTS_ATOMIC_RMW
1075d6ad668SMike Rapoport	select ARCH_SUPPORTS_DEBUG_PAGEALLOC
108d283d422SPasha Tatashin	select ARCH_SUPPORTS_PAGE_TABLE_CHECK	if X86_64
1096471b825SIngo Molnar	select ARCH_SUPPORTS_NUMA_BALANCING	if X86_64
11014df3267SThomas Gleixner	select ARCH_SUPPORTS_KMAP_LOCAL_FORCE_MAP	if NR_CPUS <= 4096
1113c516f89SSami Tolvanen	select ARCH_SUPPORTS_CFI_CLANG		if X86_64
1123c516f89SSami Tolvanen	select ARCH_USES_CFI_TRAPS		if X86_64 && CFI_CLANG
113583bfd48SNathan Chancellor	select ARCH_SUPPORTS_LTO_CLANG
114583bfd48SNathan Chancellor	select ARCH_SUPPORTS_LTO_CLANG_THIN
1156471b825SIngo Molnar	select ARCH_USE_BUILTIN_BSWAP
116dce44566SAnshuman Khandual	select ARCH_USE_MEMTEST
1176471b825SIngo Molnar	select ARCH_USE_QUEUED_RWLOCKS
1186471b825SIngo Molnar	select ARCH_USE_QUEUED_SPINLOCKS
1192ce0d7f9SMark Brown	select ARCH_USE_SYM_ANNOTATIONS
120ce4a4e56SAndy Lutomirski	select ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH
12181c22041SDaniel Borkmann	select ARCH_WANT_DEFAULT_BPF_JIT	if X86_64
122c763ea26SIngo Molnar	select ARCH_WANTS_DYNAMIC_TASK_STRUCT
12351c2ee6dSNick Desaulniers	select ARCH_WANTS_NO_INSTR
12407431506SAnshuman Khandual	select ARCH_WANT_GENERAL_HUGETLB
1253876d4a3SAlexandre Ghiti	select ARCH_WANT_HUGE_PMD_SHARE
12647010c04SMuchun Song	select ARCH_WANT_HUGETLB_PAGE_OPTIMIZE_VMEMMAP	if X86_64
12759612b24SNathan Chancellor	select ARCH_WANT_LD_ORPHAN_WARN
12838d8b4e6SHuang Ying	select ARCH_WANTS_THP_SWAP		if X86_64
129b5f06f64SBalbir Singh	select ARCH_HAS_PARANOID_L1D_FLUSH
13010916706SShile Zhang	select BUILDTIME_TABLE_SORT
1316471b825SIngo Molnar	select CLKEVT_I8253
1326471b825SIngo Molnar	select CLOCKSOURCE_VALIDATE_LAST_CYCLE
1336471b825SIngo Molnar	select CLOCKSOURCE_WATCHDOG
1347cf8f44aSAlexander Potapenko	# Word-size accesses may read uninitialized data past the trailing \0
1357cf8f44aSAlexander Potapenko	# in strings and cause false KMSAN reports.
1367cf8f44aSAlexander Potapenko	select DCACHE_WORD_ACCESS		if !KMSAN
1373aac3ebeSThomas Gleixner	select DYNAMIC_SIGFRAME
13845471cd9SLinus Torvalds	select EDAC_ATOMIC_SCRUB
13945471cd9SLinus Torvalds	select EDAC_SUPPORT
1406471b825SIngo Molnar	select GENERIC_CLOCKEVENTS_BROADCAST	if X86_64 || (X86_32 && X86_LOCAL_APIC)
1416471b825SIngo Molnar	select GENERIC_CLOCKEVENTS_MIN_ADJUST
1426471b825SIngo Molnar	select GENERIC_CMOS_UPDATE
1436471b825SIngo Molnar	select GENERIC_CPU_AUTOPROBE
14461dc0f55SThomas Gleixner	select GENERIC_CPU_VULNERABILITIES
1456471b825SIngo Molnar	select GENERIC_EARLY_IOREMAP
14627d6b4d1SThomas Gleixner	select GENERIC_ENTRY
1476471b825SIngo Molnar	select GENERIC_IOMAP
148c7d6c9ddSThomas Gleixner	select GENERIC_IRQ_EFFECTIVE_AFF_MASK	if SMP
1490fa115daSThomas Gleixner	select GENERIC_IRQ_MATRIX_ALLOCATOR	if X86_LOCAL_APIC
150ad7a929fSThomas Gleixner	select GENERIC_IRQ_MIGRATION		if SMP
1516471b825SIngo Molnar	select GENERIC_IRQ_PROBE
152c201c917SThomas Gleixner	select GENERIC_IRQ_RESERVATION_MODE
1536471b825SIngo Molnar	select GENERIC_IRQ_SHOW
1546471b825SIngo Molnar	select GENERIC_PENDING_IRQ		if SMP
1552ae27137SSteven Price	select GENERIC_PTDUMP
1566471b825SIngo Molnar	select GENERIC_SMP_IDLE_THREAD
1576471b825SIngo Molnar	select GENERIC_TIME_VSYSCALL
1587ac87074SVincenzo Frascino	select GENERIC_GETTIMEOFDAY
159550a77a7SDmitry Safonov	select GENERIC_VDSO_TIME_NS
16039656e83SChristoph Hellwig	select GUP_GET_PTE_LOW_HIGH		if X86_PAE
16117e5888eSHans de Goede	select HARDIRQS_SW_RESEND
1627edaeb68SThomas Gleixner	select HARDLOCKUP_CHECK_TIMESTAMP	if X86_64
1636471b825SIngo Molnar	select HAVE_ACPI_APEI			if ACPI
1646471b825SIngo Molnar	select HAVE_ACPI_APEI_NMI		if ACPI
1656471b825SIngo Molnar	select HAVE_ALIGNED_STRUCT_PAGE		if SLUB
1666471b825SIngo Molnar	select HAVE_ARCH_AUDITSYSCALL
1676471b825SIngo Molnar	select HAVE_ARCH_HUGE_VMAP		if X86_64 || X86_PAE
168eed1fceeSSong Liu	select HAVE_ARCH_HUGE_VMALLOC		if X86_64
1696471b825SIngo Molnar	select HAVE_ARCH_JUMP_LABEL
170b34006c4SArd Biesheuvel	select HAVE_ARCH_JUMP_LABEL_RELATIVE
171d17a1d97SAndrey Ryabinin	select HAVE_ARCH_KASAN			if X86_64
1720609ae01SDaniel Axtens	select HAVE_ARCH_KASAN_VMALLOC		if X86_64
1731dc0da6eSAlexander Potapenko	select HAVE_ARCH_KFENCE
1744ca8cc8dSAlexander Potapenko	select HAVE_ARCH_KMSAN			if X86_64
1756471b825SIngo Molnar	select HAVE_ARCH_KGDB
1769e08f57dSDaniel Cashman	select HAVE_ARCH_MMAP_RND_BITS		if MMU
1779e08f57dSDaniel Cashman	select HAVE_ARCH_MMAP_RND_COMPAT_BITS	if MMU && COMPAT
1781b028f78SDmitry Safonov	select HAVE_ARCH_COMPAT_MMAP_BASES	if MMU && COMPAT
179271ca788SArd Biesheuvel	select HAVE_ARCH_PREL32_RELOCATIONS
1806471b825SIngo Molnar	select HAVE_ARCH_SECCOMP_FILTER
181f7d83c1cSKees Cook	select HAVE_ARCH_THREAD_STRUCT_WHITELIST
182afaef01cSAlexander Popov	select HAVE_ARCH_STACKLEAK
1836471b825SIngo Molnar	select HAVE_ARCH_TRACEHOOK
1846471b825SIngo Molnar	select HAVE_ARCH_TRANSPARENT_HUGEPAGE
185a00cc7d9SMatthew Wilcox	select HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD if X86_64
186b64d8d1eSPeter Xu	select HAVE_ARCH_USERFAULTFD_WP         if X86_64 && USERFAULTFD
1877677f7fdSAxel Rasmussen	select HAVE_ARCH_USERFAULTFD_MINOR	if X86_64 && USERFAULTFD
188e37e43a4SAndy Lutomirski	select HAVE_ARCH_VMAP_STACK		if X86_64
189fe950f60SKees Cook	select HAVE_ARCH_RANDOMIZE_KSTACK_OFFSET
190c763ea26SIngo Molnar	select HAVE_ARCH_WITHIN_STACK_FRAMES
1912ff2b7ecSMasahiro Yamada	select HAVE_ASM_MODVERSIONS
1926471b825SIngo Molnar	select HAVE_CMPXCHG_DOUBLE
1936471b825SIngo Molnar	select HAVE_CMPXCHG_LOCAL
19424a9c541SFrederic Weisbecker	select HAVE_CONTEXT_TRACKING_USER		if X86_64
19524a9c541SFrederic Weisbecker	select HAVE_CONTEXT_TRACKING_USER_OFFSTACK	if HAVE_CONTEXT_TRACKING_USER
1966471b825SIngo Molnar	select HAVE_C_RECORDMCOUNT
19703f16cd0SJosh Poimboeuf	select HAVE_OBJTOOL_MCOUNT		if HAVE_OBJTOOL
1984ed308c4SSteven Rostedt (Google)	select HAVE_BUILDTIME_MCOUNT_SORT
1996471b825SIngo Molnar	select HAVE_DEBUG_KMEMLEAK
2009c5a3621SAkinobu Mita	select HAVE_DMA_CONTIGUOUS
201677aa9f7SSteven Rostedt	select HAVE_DYNAMIC_FTRACE
20206aeaaeaSMasami Hiramatsu	select HAVE_DYNAMIC_FTRACE_WITH_REGS
20302a474caSSteven Rostedt (VMware)	select HAVE_DYNAMIC_FTRACE_WITH_ARGS	if X86_64
204562955feSSteven Rostedt (VMware)	select HAVE_DYNAMIC_FTRACE_WITH_DIRECT_CALLS
205c316eb44SHeiko Carstens	select HAVE_SAMPLE_FTRACE_DIRECT	if X86_64
206503e4510SHeiko Carstens	select HAVE_SAMPLE_FTRACE_DIRECT_MULTI	if X86_64
20703f5781bSWang YanQing	select HAVE_EBPF_JIT
20858340a07SJohannes Berg	select HAVE_EFFICIENT_UNALIGNED_ACCESS
2096630a8e5SChristoph Hellwig	select HAVE_EISA
2105f56a5dfSJiri Slaby	select HAVE_EXIT_THREAD
21167a929e0SChristoph Hellwig	select HAVE_FAST_GUP
212644e0e8dSSteven Rostedt (VMware)	select HAVE_FENTRY			if X86_64 || DYNAMIC_FTRACE
2136471b825SIngo Molnar	select HAVE_FTRACE_MCOUNT_RECORD
2144a30e4c9SSteven Rostedt (VMware)	select HAVE_FUNCTION_GRAPH_TRACER	if X86_32 || (X86_64 && DYNAMIC_FTRACE)
2156471b825SIngo Molnar	select HAVE_FUNCTION_TRACER
2166b90bd4bSEmese Revfy	select HAVE_GCC_PLUGINS
2170067f129SK.Prasad	select HAVE_HW_BREAKPOINT
2186471b825SIngo Molnar	select HAVE_IOREMAP_PROT
219624db9eaSThomas Gleixner	select HAVE_IRQ_EXIT_ON_IRQ_STACK	if X86_64
2206471b825SIngo Molnar	select HAVE_IRQ_TIME_ACCOUNTING
2214ab7674fSJosh Poimboeuf	select HAVE_JUMP_LABEL_HACK		if HAVE_OBJTOOL
2226471b825SIngo Molnar	select HAVE_KERNEL_BZIP2
2236471b825SIngo Molnar	select HAVE_KERNEL_GZIP
2246471b825SIngo Molnar	select HAVE_KERNEL_LZ4
2256471b825SIngo Molnar	select HAVE_KERNEL_LZMA
2266471b825SIngo Molnar	select HAVE_KERNEL_LZO
2276471b825SIngo Molnar	select HAVE_KERNEL_XZ
228fb46d057SNick Terrell	select HAVE_KERNEL_ZSTD
2296471b825SIngo Molnar	select HAVE_KPROBES
2306471b825SIngo Molnar	select HAVE_KPROBES_ON_FTRACE
231540adea3SMasami Hiramatsu	select HAVE_FUNCTION_ERROR_INJECTION
2326471b825SIngo Molnar	select HAVE_KRETPROBES
233f3a112c0SMasami Hiramatsu	select HAVE_RETHOOK
2346471b825SIngo Molnar	select HAVE_KVM
2356471b825SIngo Molnar	select HAVE_LIVEPATCH			if X86_64
2360102752eSFrederic Weisbecker	select HAVE_MIXED_BREAKPOINTS_REGS
237ee9f8fceSJosh Poimboeuf	select HAVE_MOD_ARCH_SPECIFIC
2389f132f7eSJoel Fernandes (Google)	select HAVE_MOVE_PMD
239be37c98dSKalesh Singh	select HAVE_MOVE_PUD
24022102f45SJosh Poimboeuf	select HAVE_NOINSTR_HACK		if HAVE_OBJTOOL
24142a0bb3fSPetr Mladek	select HAVE_NMI
242489e355bSJosh Poimboeuf	select HAVE_NOINSTR_VALIDATION		if HAVE_OBJTOOL
24303f16cd0SJosh Poimboeuf	select HAVE_OBJTOOL			if X86_64
2446471b825SIngo Molnar	select HAVE_OPTPROBES
2456471b825SIngo Molnar	select HAVE_PCSPKR_PLATFORM
2466471b825SIngo Molnar	select HAVE_PERF_EVENTS
247c01d4323SFrederic Weisbecker	select HAVE_PERF_EVENTS_NMI
24892e5aae4SNicholas Piggin	select HAVE_HARDLOCKUP_DETECTOR_PERF	if PERF_EVENTS && HAVE_PERF_EVENTS_NMI
249eb01d42aSChristoph Hellwig	select HAVE_PCI
250c5e63197SJiri Olsa	select HAVE_PERF_REGS
251c5ebcedbSJiri Olsa	select HAVE_PERF_USER_STACK_DUMP
252ff2e6d72SPeter Zijlstra	select MMU_GATHER_RCU_TABLE_FREE	if PARAVIRT
2531e9fdf21SPeter Zijlstra	select MMU_GATHER_MERGE_VMAS
25400998085SThomas Gleixner	select HAVE_POSIX_CPU_TIMERS_TASK_WORK
2556471b825SIngo Molnar	select HAVE_REGS_AND_STACK_ACCESS_API
25603f16cd0SJosh Poimboeuf	select HAVE_RELIABLE_STACKTRACE		if UNWINDER_ORC || STACK_VALIDATION
2573c88ee19SMasami Hiramatsu	select HAVE_FUNCTION_ARG_ACCESS_API
2587ecd19cfSKefeng Wang	select HAVE_SETUP_PER_CPU_AREA
259cd1a41ceSThomas Gleixner	select HAVE_SOFTIRQ_ON_OWN_STACK
260d148eac0SMasahiro Yamada	select HAVE_STACKPROTECTOR		if CC_HAS_SANE_STACKPROTECTOR
26103f16cd0SJosh Poimboeuf	select HAVE_STACK_VALIDATION		if HAVE_OBJTOOL
262e6d6c071SJosh Poimboeuf	select HAVE_STATIC_CALL
26303f16cd0SJosh Poimboeuf	select HAVE_STATIC_CALL_INLINE		if HAVE_OBJTOOL
26499cf983cSMark Rutland	select HAVE_PREEMPT_DYNAMIC_CALL
265d6761b8fSMathieu Desnoyers	select HAVE_RSEQ
26609498135SMiguel Ojeda	select HAVE_RUST			if X86_64
2676471b825SIngo Molnar	select HAVE_SYSCALL_TRACEPOINTS
2685f3da8c0SJosh Poimboeuf	select HAVE_UACCESS_VALIDATION		if HAVE_OBJTOOL
2696471b825SIngo Molnar	select HAVE_UNSTABLE_SCHED_CLOCK
2707c68af6eSAvi Kivity	select HAVE_USER_RETURN_NOTIFIER
2717ac87074SVincenzo Frascino	select HAVE_GENERIC_VDSO
27205736e4aSThomas Gleixner	select HOTPLUG_SMT			if SMP
273c0185808SThomas Gleixner	select IRQ_FORCED_THREADING
2747ecd19cfSKefeng Wang	select NEED_PER_CPU_EMBED_FIRST_CHUNK
2757ecd19cfSKefeng Wang	select NEED_PER_CPU_PAGE_FIRST_CHUNK
27686596f0aSChristoph Hellwig	select NEED_SG_DMA_LENGTH
2772eac9c2dSChristoph Hellwig	select PCI_DOMAINS			if PCI
278625210cfSSinan Kaya	select PCI_LOCKLESS_CONFIG		if PCI
2796471b825SIngo Molnar	select PERF_EVENTS
2803195ef59SPrarit Bhargava	select RTC_LIB
281d6faca40SArnd Bergmann	select RTC_MC146818_LIB
2826471b825SIngo Molnar	select SPARSE_IRQ
28383fe27eaSPranith Kumar	select SRCU
2846471b825SIngo Molnar	select SYSCTL_EXCEPTION_TRACE
28515f4eae7SAndy Lutomirski	select THREAD_INFO_IN_TASK
2864aae683fSMasahiro Yamada	select TRACE_IRQFLAGS_SUPPORT
2874510bffbSMark Rutland	select TRACE_IRQFLAGS_NMI_SUPPORT
2886471b825SIngo Molnar	select USER_STACKTRACE_SUPPORT
2893b02a051SIngo Molnar	select HAVE_ARCH_KCSAN			if X86_64
2906471b825SIngo Molnar	select X86_FEATURE_NAMES		if PROC_FS
2910c608dadSAubrey Li	select PROC_PID_ARCH_STATUS		if PROC_FS
29250468e43SJarkko Sakkinen	select HAVE_ARCH_NODE_DEV_GROUP		if X86_SGX
293*d49a0626SPeter Zijlstra	select FUNCTION_ALIGNMENT_16B		if X86_64 || X86_ALIGNMENT_16
294*d49a0626SPeter Zijlstra	select FUNCTION_ALIGNMENT_4B
2959e2b4be3SNayna Jain	imply IMA_SECURE_AND_OR_TRUSTED_BOOT    if EFI
296ceea991aSJiri Olsa	select HAVE_DYNAMIC_FTRACE_NO_PATCHABLE
2977d8330a5SBalbir Singh
298ba7e4d13SIngo Molnarconfig INSTRUCTION_DECODER
2993120e25eSJan Beulich	def_bool y
3003120e25eSJan Beulich	depends on KPROBES || PERF_EVENTS || UPROBES
301ba7e4d13SIngo Molnar
30251b26adaSLinus Torvaldsconfig OUTPUT_FORMAT
30351b26adaSLinus Torvalds	string
30451b26adaSLinus Torvalds	default "elf32-i386" if X86_32
30551b26adaSLinus Torvalds	default "elf64-x86-64" if X86_64
30651b26adaSLinus Torvalds
3078d5fffb9SSam Ravnborgconfig LOCKDEP_SUPPORT
3083c2362e6SHarvey Harrison	def_bool y
3098d5fffb9SSam Ravnborg
3108d5fffb9SSam Ravnborgconfig STACKTRACE_SUPPORT
3113c2362e6SHarvey Harrison	def_bool y
3128d5fffb9SSam Ravnborg
3138d5fffb9SSam Ravnborgconfig MMU
3143c2362e6SHarvey Harrison	def_bool y
3158d5fffb9SSam Ravnborg
3169e08f57dSDaniel Cashmanconfig ARCH_MMAP_RND_BITS_MIN
3179e08f57dSDaniel Cashman	default 28 if 64BIT
3189e08f57dSDaniel Cashman	default 8
3199e08f57dSDaniel Cashman
3209e08f57dSDaniel Cashmanconfig ARCH_MMAP_RND_BITS_MAX
3219e08f57dSDaniel Cashman	default 32 if 64BIT
3229e08f57dSDaniel Cashman	default 16
3239e08f57dSDaniel Cashman
3249e08f57dSDaniel Cashmanconfig ARCH_MMAP_RND_COMPAT_BITS_MIN
3259e08f57dSDaniel Cashman	default 8
3269e08f57dSDaniel Cashman
3279e08f57dSDaniel Cashmanconfig ARCH_MMAP_RND_COMPAT_BITS_MAX
3289e08f57dSDaniel Cashman	default 16
3299e08f57dSDaniel Cashman
3308d5fffb9SSam Ravnborgconfig SBUS
3318d5fffb9SSam Ravnborg	bool
3328d5fffb9SSam Ravnborg
3338d5fffb9SSam Ravnborgconfig GENERIC_ISA_DMA
3343120e25eSJan Beulich	def_bool y
3353120e25eSJan Beulich	depends on ISA_DMA_API
3368d5fffb9SSam Ravnborg
337d911c67eSAlexander Potapenkoconfig GENERIC_CSUM
338d911c67eSAlexander Potapenko	bool
339d911c67eSAlexander Potapenko	default y if KMSAN || KASAN
340d911c67eSAlexander Potapenko
3418d5fffb9SSam Ravnborgconfig GENERIC_BUG
3423c2362e6SHarvey Harrison	def_bool y
3438d5fffb9SSam Ravnborg	depends on BUG
344b93a531eSJan Beulich	select GENERIC_BUG_RELATIVE_POINTERS if X86_64
345b93a531eSJan Beulich
346b93a531eSJan Beulichconfig GENERIC_BUG_RELATIVE_POINTERS
347b93a531eSJan Beulich	bool
3488d5fffb9SSam Ravnborg
3498d5fffb9SSam Ravnborgconfig ARCH_MAY_HAVE_PC_FDC
3503120e25eSJan Beulich	def_bool y
3513120e25eSJan Beulich	depends on ISA_DMA_API
3528d5fffb9SSam Ravnborg
3531032c0baSSam Ravnborgconfig GENERIC_CALIBRATE_DELAY
3541032c0baSSam Ravnborg	def_bool y
3551032c0baSSam Ravnborg
3569a0b8415Svenkatesh.pallipadi@intel.comconfig ARCH_HAS_CPU_RELAX
3579a0b8415Svenkatesh.pallipadi@intel.com	def_bool y
3588d5fffb9SSam Ravnborg
359801e4062SJohannes Bergconfig ARCH_HIBERNATION_POSSIBLE
360801e4062SJohannes Berg	def_bool y
361801e4062SJohannes Berg
362d7109fe3SAndy Shevchenkoconfig ARCH_NR_GPIO
363d7109fe3SAndy Shevchenko	int
364d7109fe3SAndy Shevchenko	default 1024 if X86_64
365d7109fe3SAndy Shevchenko	default 512
366d7109fe3SAndy Shevchenko
367f4cb5700SJohannes Bergconfig ARCH_SUSPEND_POSSIBLE
368f4cb5700SJohannes Berg	def_bool y
369f4cb5700SJohannes Berg
3708d5fffb9SSam Ravnborgconfig AUDIT_ARCH
371e0fd24a3SJan Beulich	def_bool y if X86_64
3728d5fffb9SSam Ravnborg
373d6f2d75aSAndrey Ryabininconfig KASAN_SHADOW_OFFSET
374d6f2d75aSAndrey Ryabinin	hex
375d6f2d75aSAndrey Ryabinin	depends on KASAN
376d6f2d75aSAndrey Ryabinin	default 0xdffffc0000000000
377d6f2d75aSAndrey Ryabinin
37869575d38SShane Wangconfig HAVE_INTEL_TXT
37969575d38SShane Wang	def_bool y
3806ea30386SKees Cook	depends on INTEL_IOMMU && ACPI
38169575d38SShane Wang
3826b0c3d44SSam Ravnborgconfig X86_32_SMP
3836b0c3d44SSam Ravnborg	def_bool y
3846b0c3d44SSam Ravnborg	depends on X86_32 && SMP
3856b0c3d44SSam Ravnborg
3866b0c3d44SSam Ravnborgconfig X86_64_SMP
3876b0c3d44SSam Ravnborg	def_bool y
3886b0c3d44SSam Ravnborg	depends on X86_64 && SMP
3896b0c3d44SSam Ravnborg
3902b144498SSrikar Dronamrajuconfig ARCH_SUPPORTS_UPROBES
3912b144498SSrikar Dronamraju	def_bool y
3922b144498SSrikar Dronamraju
393d20642f0SRob Herringconfig FIX_EARLYCON_MEM
394d20642f0SRob Herring	def_bool y
395d20642f0SRob Herring
39694d49eb3SKirill A. Shutemovconfig DYNAMIC_PHYSICAL_MASK
39794d49eb3SKirill A. Shutemov	bool
39894d49eb3SKirill A. Shutemov
39998233368SKirill A. Shutemovconfig PGTABLE_LEVELS
40098233368SKirill A. Shutemov	int
40177ef56e4SKirill A. Shutemov	default 5 if X86_5LEVEL
40298233368SKirill A. Shutemov	default 4 if X86_64
40398233368SKirill A. Shutemov	default 3 if X86_PAE
40498233368SKirill A. Shutemov	default 2
40598233368SKirill A. Shutemov
4062a61f474SMasahiro Yamadaconfig CC_HAS_SANE_STACKPROTECTOR
4072a61f474SMasahiro Yamada	bool
4081b866781SNathan Chancellor	default $(success,$(srctree)/scripts/gcc-x86_64-has-stack-protector.sh $(CC) $(CLANG_FLAGS)) if 64BIT
4091b866781SNathan Chancellor	default $(success,$(srctree)/scripts/gcc-x86_32-has-stack-protector.sh $(CC) $(CLANG_FLAGS))
4102a61f474SMasahiro Yamada	help
4112a61f474SMasahiro Yamada	  We have to make sure stack protector is unconditionally disabled if
4123fb0fdb3SAndy Lutomirski	  the compiler produces broken code or if it does not let us control
4133fb0fdb3SAndy Lutomirski	  the segment on 32-bit kernels.
4142a61f474SMasahiro Yamada
415506f1d07SSam Ravnborgmenu "Processor type and features"
416506f1d07SSam Ravnborg
417506f1d07SSam Ravnborgconfig SMP
418506f1d07SSam Ravnborg	bool "Symmetric multi-processing support"
419a7f7f624SMasahiro Yamada	help
420506f1d07SSam Ravnborg	  This enables support for systems with more than one CPU. If you have
4214a474157SRobert Graffham	  a system with only one CPU, say N. If you have a system with more
4224a474157SRobert Graffham	  than one CPU, say Y.
423506f1d07SSam Ravnborg
4244a474157SRobert Graffham	  If you say N here, the kernel will run on uni- and multiprocessor
425506f1d07SSam Ravnborg	  machines, but will use only one CPU of a multiprocessor machine. If
426506f1d07SSam Ravnborg	  you say Y here, the kernel will run on many, but not all,
4274a474157SRobert Graffham	  uniprocessor machines. On a uniprocessor machine, the kernel
428506f1d07SSam Ravnborg	  will run faster if you say N here.
429506f1d07SSam Ravnborg
430506f1d07SSam Ravnborg	  Note that if you say Y here and choose architecture "586" or
431506f1d07SSam Ravnborg	  "Pentium" under "Processor family", the kernel will not work on 486
432506f1d07SSam Ravnborg	  architectures. Similarly, multiprocessor kernels for the "PPro"
433506f1d07SSam Ravnborg	  architecture may not work on all Pentium based boards.
434506f1d07SSam Ravnborg
435506f1d07SSam Ravnborg	  People using multiprocessor machines who say Y here should also say
436506f1d07SSam Ravnborg	  Y to "Enhanced Real Time Clock Support", below. The "Advanced Power
437506f1d07SSam Ravnborg	  Management" code will be disabled if you say Y here.
438506f1d07SSam Ravnborg
439cb1aaebeSMauro Carvalho Chehab	  See also <file:Documentation/x86/i386/IO-APIC.rst>,
4404f4cfa6cSMauro Carvalho Chehab	  <file:Documentation/admin-guide/lockup-watchdogs.rst> and the SMP-HOWTO available at
441506f1d07SSam Ravnborg	  <http://www.tldp.org/docs.html#howto>.
442506f1d07SSam Ravnborg
443506f1d07SSam Ravnborg	  If you don't know what to do here, say N.
444506f1d07SSam Ravnborg
4459def39beSJosh Triplettconfig X86_FEATURE_NAMES
4469def39beSJosh Triplett	bool "Processor feature human-readable names" if EMBEDDED
4479def39beSJosh Triplett	default y
448a7f7f624SMasahiro Yamada	help
4499def39beSJosh Triplett	  This option compiles in a table of x86 feature bits and corresponding
4509def39beSJosh Triplett	  names.  This is required to support /proc/cpuinfo and a few kernel
4519def39beSJosh Triplett	  messages.  You can disable this to save space, at the expense of
4529def39beSJosh Triplett	  making those few kernel messages show numeric feature bits instead.
4539def39beSJosh Triplett
4549def39beSJosh Triplett	  If in doubt, say Y.
4559def39beSJosh Triplett
45606cd9a7dSYinghai Luconfig X86_X2APIC
45706cd9a7dSYinghai Lu	bool "Support x2apic"
45819e3d60dSJan Kiszka	depends on X86_LOCAL_APIC && X86_64 && (IRQ_REMAP || HYPERVISOR_GUEST)
459a7f7f624SMasahiro Yamada	help
46006cd9a7dSYinghai Lu	  This enables x2apic support on CPUs that have this feature.
46106cd9a7dSYinghai Lu
46206cd9a7dSYinghai Lu	  This allows 32-bit apic IDs (so it can support very large systems),
46306cd9a7dSYinghai Lu	  and accesses the local apic via MSRs not via mmio.
46406cd9a7dSYinghai Lu
465b8d1d163SDaniel Sneddon	  Some Intel systems circa 2022 and later are locked into x2APIC mode
466b8d1d163SDaniel Sneddon	  and can not fall back to the legacy APIC modes if SGX or TDX are
467b8d1d163SDaniel Sneddon	  enabled in the BIOS.  They will be unable to boot without enabling
468b8d1d163SDaniel Sneddon	  this option.
469b8d1d163SDaniel Sneddon
47006cd9a7dSYinghai Lu	  If you don't know what to do here, say N.
47106cd9a7dSYinghai Lu
4726695c85bSYinghai Luconfig X86_MPPARSE
4734590d98fSAndy Shevchenko	bool "Enable MPS table" if ACPI
4747a527688SJan Beulich	default y
4755ab74722SIngo Molnar	depends on X86_LOCAL_APIC
476a7f7f624SMasahiro Yamada	help
4776695c85bSYinghai Lu	  For old smp systems that do not have proper acpi support. Newer systems
4786695c85bSYinghai Lu	  (esp with 64bit cpus) with acpi support, MADT and DSDT will override it
4796695c85bSYinghai Lu
480ddd70cf9SJun Nakajimaconfig GOLDFISH
481ddd70cf9SJun Nakajima	def_bool y
482ddd70cf9SJun Nakajima	depends on X86_GOLDFISH
483ddd70cf9SJun Nakajima
484e6d42931SJohannes Weinerconfig X86_CPU_RESCTRL
485e6d42931SJohannes Weiner	bool "x86 CPU resource control support"
4866fe07ce3SBabu Moger	depends on X86 && (CPU_SUP_INTEL || CPU_SUP_AMD)
48759fe5a77SThomas Gleixner	select KERNFS
488e79f15a4SChen Yu	select PROC_CPU_RESCTRL		if PROC_FS
48978e99b4aSFenghua Yu	help
490e6d42931SJohannes Weiner	  Enable x86 CPU resource control support.
4916fe07ce3SBabu Moger
4926fe07ce3SBabu Moger	  Provide support for the allocation and monitoring of system resources
4936fe07ce3SBabu Moger	  usage by the CPU.
4946fe07ce3SBabu Moger
4956fe07ce3SBabu Moger	  Intel calls this Intel Resource Director Technology
4966fe07ce3SBabu Moger	  (Intel(R) RDT). More information about RDT can be found in the
4976fe07ce3SBabu Moger	  Intel x86 Architecture Software Developer Manual.
4986fe07ce3SBabu Moger
4996fe07ce3SBabu Moger	  AMD calls this AMD Platform Quality of Service (AMD QoS).
5006fe07ce3SBabu Moger	  More information about AMD QoS can be found in the AMD64 Technology
5016fe07ce3SBabu Moger	  Platform Quality of Service Extensions manual.
50278e99b4aSFenghua Yu
50378e99b4aSFenghua Yu	  Say N if unsure.
50478e99b4aSFenghua Yu
5058425091fSRavikiran G Thirumalaiif X86_32
506a0d0bb4dSRandy Dunlapconfig X86_BIGSMP
507a0d0bb4dSRandy Dunlap	bool "Support for big SMP systems with more than 8 CPUs"
508a0d0bb4dSRandy Dunlap	depends on SMP
509a7f7f624SMasahiro Yamada	help
510e133f6eaSRandy Dunlap	  This option is needed for the systems that have more than 8 CPUs.
511a0d0bb4dSRandy Dunlap
512c5c606d9SRavikiran G Thirumalaiconfig X86_EXTENDED_PLATFORM
513c5c606d9SRavikiran G Thirumalai	bool "Support for extended (non-PC) x86 platforms"
514c5c606d9SRavikiran G Thirumalai	default y
515a7f7f624SMasahiro Yamada	help
51606ac8346SIngo Molnar	  If you disable this option then the kernel will only support
51706ac8346SIngo Molnar	  standard PC platforms. (which covers the vast majority of
51806ac8346SIngo Molnar	  systems out there.)
51906ac8346SIngo Molnar
5208425091fSRavikiran G Thirumalai	  If you enable this option then you'll be able to select support
5218425091fSRavikiran G Thirumalai	  for the following (non-PC) 32 bit x86 platforms:
522cb7b8023SBen Hutchings		Goldfish (Android emulator)
5238425091fSRavikiran G Thirumalai		AMD Elan
5248425091fSRavikiran G Thirumalai		RDC R-321x SoC
5258425091fSRavikiran G Thirumalai		SGI 320/540 (Visual Workstation)
52683125a3aSAlessandro Rubini		STA2X11-based (e.g. Northville)
5273f4110a4SThomas Gleixner		Moorestown MID devices
52806ac8346SIngo Molnar
52906ac8346SIngo Molnar	  If you have one of these systems, or if you want to build a
53006ac8346SIngo Molnar	  generic distribution kernel, say Y here - otherwise say N.
531758cd94aSJuerg Haefligerendif # X86_32
53206ac8346SIngo Molnar
5338425091fSRavikiran G Thirumalaiif X86_64
5348425091fSRavikiran G Thirumalaiconfig X86_EXTENDED_PLATFORM
5358425091fSRavikiran G Thirumalai	bool "Support for extended (non-PC) x86 platforms"
5368425091fSRavikiran G Thirumalai	default y
537a7f7f624SMasahiro Yamada	help
5388425091fSRavikiran G Thirumalai	  If you disable this option then the kernel will only support
5398425091fSRavikiran G Thirumalai	  standard PC platforms. (which covers the vast majority of
5408425091fSRavikiran G Thirumalai	  systems out there.)
5418425091fSRavikiran G Thirumalai
5428425091fSRavikiran G Thirumalai	  If you enable this option then you'll be able to select support
5438425091fSRavikiran G Thirumalai	  for the following (non-PC) 64 bit x86 platforms:
54444b111b5SSteffen Persvold		Numascale NumaChip
5458425091fSRavikiran G Thirumalai		ScaleMP vSMP
5468425091fSRavikiran G Thirumalai		SGI Ultraviolet
5478425091fSRavikiran G Thirumalai
5488425091fSRavikiran G Thirumalai	  If you have one of these systems, or if you want to build a
5498425091fSRavikiran G Thirumalai	  generic distribution kernel, say Y here - otherwise say N.
550758cd94aSJuerg Haefligerendif # X86_64
551c5c606d9SRavikiran G Thirumalai# This is an alphabetically sorted list of 64 bit extended platforms
552c5c606d9SRavikiran G Thirumalai# Please maintain the alphabetic order if and when there are additions
55344b111b5SSteffen Persvoldconfig X86_NUMACHIP
55444b111b5SSteffen Persvold	bool "Numascale NumaChip"
55544b111b5SSteffen Persvold	depends on X86_64
55644b111b5SSteffen Persvold	depends on X86_EXTENDED_PLATFORM
55744b111b5SSteffen Persvold	depends on NUMA
55844b111b5SSteffen Persvold	depends on SMP
55944b111b5SSteffen Persvold	depends on X86_X2APIC
560f9726bfdSDaniel J Blueman	depends on PCI_MMCONFIG
561a7f7f624SMasahiro Yamada	help
56244b111b5SSteffen Persvold	  Adds support for Numascale NumaChip large-SMP systems. Needed to
56344b111b5SSteffen Persvold	  enable more than ~168 cores.
56444b111b5SSteffen Persvold	  If you don't have one of these, you should say N here.
56503b48632SNick Piggin
5666a48565eSIngo Molnarconfig X86_VSMP
567c5c606d9SRavikiran G Thirumalai	bool "ScaleMP vSMP"
5686276a074SBorislav Petkov	select HYPERVISOR_GUEST
5696a48565eSIngo Molnar	select PARAVIRT
5706a48565eSIngo Molnar	depends on X86_64 && PCI
571c5c606d9SRavikiran G Thirumalai	depends on X86_EXTENDED_PLATFORM
572ead91d4bSShai Fultheim	depends on SMP
573a7f7f624SMasahiro Yamada	help
5746a48565eSIngo Molnar	  Support for ScaleMP vSMP systems.  Say 'Y' here if this kernel is
5756a48565eSIngo Molnar	  supposed to run on these EM64T-based machines.  Only choose this option
5766a48565eSIngo Molnar	  if you have one of these machines.
5776a48565eSIngo Molnar
578c5c606d9SRavikiran G Thirumalaiconfig X86_UV
579c5c606d9SRavikiran G Thirumalai	bool "SGI Ultraviolet"
580c5c606d9SRavikiran G Thirumalai	depends on X86_64
581c5c606d9SRavikiran G Thirumalai	depends on X86_EXTENDED_PLATFORM
58254c28d29SJack Steiner	depends on NUMA
5831ecb4ae5SAndrew Morton	depends on EFI
584c2209ea5SIngo Molnar	depends on KEXEC_CORE
5859d6c26e7SSuresh Siddha	depends on X86_X2APIC
5861222e564SIngo Molnar	depends on PCI
587a7f7f624SMasahiro Yamada	help
588c5c606d9SRavikiran G Thirumalai	  This option is needed in order to support SGI Ultraviolet systems.
589c5c606d9SRavikiran G Thirumalai	  If you don't have one of these, you should say N here.
590c5c606d9SRavikiran G Thirumalai
591c5c606d9SRavikiran G Thirumalai# Following is an alphabetically sorted list of 32 bit extended platforms
592c5c606d9SRavikiran G Thirumalai# Please maintain the alphabetic order if and when there are additions
593506f1d07SSam Ravnborg
594ddd70cf9SJun Nakajimaconfig X86_GOLDFISH
595ddd70cf9SJun Nakajima	bool "Goldfish (Virtual Platform)"
596cb7b8023SBen Hutchings	depends on X86_EXTENDED_PLATFORM
597a7f7f624SMasahiro Yamada	help
598ddd70cf9SJun Nakajima	  Enable support for the Goldfish virtual platform used primarily
599ddd70cf9SJun Nakajima	  for Android development. Unless you are building for the Android
600ddd70cf9SJun Nakajima	  Goldfish emulator say N here.
601ddd70cf9SJun Nakajima
602c751e17bSThomas Gleixnerconfig X86_INTEL_CE
603c751e17bSThomas Gleixner	bool "CE4100 TV platform"
604c751e17bSThomas Gleixner	depends on PCI
605c751e17bSThomas Gleixner	depends on PCI_GODIRECT
6066084a6e2SJiang Liu	depends on X86_IO_APIC
607c751e17bSThomas Gleixner	depends on X86_32
608c751e17bSThomas Gleixner	depends on X86_EXTENDED_PLATFORM
60937bc9f50SDirk Brandewie	select X86_REBOOTFIXUPS
610da6b737bSSebastian Andrzej Siewior	select OF
611da6b737bSSebastian Andrzej Siewior	select OF_EARLY_FLATTREE
612a7f7f624SMasahiro Yamada	help
613c751e17bSThomas Gleixner	  Select for the Intel CE media processor (CE4100) SOC.
614c751e17bSThomas Gleixner	  This option compiles in support for the CE4100 SOC for settop
615c751e17bSThomas Gleixner	  boxes and media devices.
616c751e17bSThomas Gleixner
6174cb9b00fSDavid Cohenconfig X86_INTEL_MID
61843605ef1SAlan Cox	bool "Intel MID platform support"
61943605ef1SAlan Cox	depends on X86_EXTENDED_PLATFORM
620edc6bc78SDavid Cohen	depends on X86_PLATFORM_DEVICES
6211ea7c673SAlan Cox	depends on PCI
6223fda5bb4SAndy Shevchenko	depends on X86_64 || (PCI_GOANY && X86_32)
6231ea7c673SAlan Cox	depends on X86_IO_APIC
6244cb9b00fSDavid Cohen	select I2C
6257c9c3a1eSAlan Cox	select DW_APB_TIMER
62654b34aa0SMika Westerberg	select INTEL_SCU_PCI
627a7f7f624SMasahiro Yamada	help
6284cb9b00fSDavid Cohen	  Select to build a kernel capable of supporting Intel MID (Mobile
6294cb9b00fSDavid Cohen	  Internet Device) platform systems which do not have the PCI legacy
6304cb9b00fSDavid Cohen	  interfaces. If you are building for a PC class system say N here.
6311ea7c673SAlan Cox
6324cb9b00fSDavid Cohen	  Intel MID platforms are based on an Intel processor and chipset which
6334cb9b00fSDavid Cohen	  consume less power than most of the x86 derivatives.
63443605ef1SAlan Cox
6358bbc2a13SBryan O'Donoghueconfig X86_INTEL_QUARK
6368bbc2a13SBryan O'Donoghue	bool "Intel Quark platform support"
6378bbc2a13SBryan O'Donoghue	depends on X86_32
6388bbc2a13SBryan O'Donoghue	depends on X86_EXTENDED_PLATFORM
6398bbc2a13SBryan O'Donoghue	depends on X86_PLATFORM_DEVICES
6408bbc2a13SBryan O'Donoghue	depends on X86_TSC
6418bbc2a13SBryan O'Donoghue	depends on PCI
6428bbc2a13SBryan O'Donoghue	depends on PCI_GOANY
6438bbc2a13SBryan O'Donoghue	depends on X86_IO_APIC
6448bbc2a13SBryan O'Donoghue	select IOSF_MBI
6458bbc2a13SBryan O'Donoghue	select INTEL_IMR
6469ab6eb51SAndy Shevchenko	select COMMON_CLK
647a7f7f624SMasahiro Yamada	help
6488bbc2a13SBryan O'Donoghue	  Select to include support for Quark X1000 SoC.
6498bbc2a13SBryan O'Donoghue	  Say Y here if you have a Quark based system such as the Arduino
6508bbc2a13SBryan O'Donoghue	  compatible Intel Galileo.
6518bbc2a13SBryan O'Donoghue
6523d48aab1SMika Westerbergconfig X86_INTEL_LPSS
6533d48aab1SMika Westerberg	bool "Intel Low Power Subsystem Support"
6545962dd22SSinan Kaya	depends on X86 && ACPI && PCI
6553d48aab1SMika Westerberg	select COMMON_CLK
6560f531431SMathias Nyman	select PINCTRL
657eebb3e8dSAndy Shevchenko	select IOSF_MBI
658a7f7f624SMasahiro Yamada	help
6593d48aab1SMika Westerberg	  Select to build support for Intel Low Power Subsystem such as
6603d48aab1SMika Westerberg	  found on Intel Lynxpoint PCH. Selecting this option enables
6610f531431SMathias Nyman	  things like clock tree (common clock framework) and pincontrol
6620f531431SMathias Nyman	  which are needed by the LPSS peripheral drivers.
6633d48aab1SMika Westerberg
66492082a88SKen Xueconfig X86_AMD_PLATFORM_DEVICE
66592082a88SKen Xue	bool "AMD ACPI2Platform devices support"
66692082a88SKen Xue	depends on ACPI
66792082a88SKen Xue	select COMMON_CLK
66892082a88SKen Xue	select PINCTRL
669a7f7f624SMasahiro Yamada	help
67092082a88SKen Xue	  Select to interpret AMD specific ACPI device to platform device
67192082a88SKen Xue	  such as I2C, UART, GPIO found on AMD Carrizo and later chipsets.
67292082a88SKen Xue	  I2C and UART depend on COMMON_CLK to set clock. GPIO driver is
67392082a88SKen Xue	  implemented under PINCTRL subsystem.
67492082a88SKen Xue
675ced3ce76SDavid E. Boxconfig IOSF_MBI
676ced3ce76SDavid E. Box	tristate "Intel SoC IOSF Sideband support for SoC platforms"
677ced3ce76SDavid E. Box	depends on PCI
678a7f7f624SMasahiro Yamada	help
679ced3ce76SDavid E. Box	  This option enables sideband register access support for Intel SoC
680ced3ce76SDavid E. Box	  platforms. On these platforms the IOSF sideband is used in lieu of
681ced3ce76SDavid E. Box	  MSR's for some register accesses, mostly but not limited to thermal
682ced3ce76SDavid E. Box	  and power. Drivers may query the availability of this device to
683ced3ce76SDavid E. Box	  determine if they need the sideband in order to work on these
684ced3ce76SDavid E. Box	  platforms. The sideband is available on the following SoC products.
685ced3ce76SDavid E. Box	  This list is not meant to be exclusive.
686ced3ce76SDavid E. Box	   - BayTrail
687ced3ce76SDavid E. Box	   - Braswell
688ced3ce76SDavid E. Box	   - Quark
689ced3ce76SDavid E. Box
690ced3ce76SDavid E. Box	  You should say Y if you are running a kernel on one of these SoC's.
691ced3ce76SDavid E. Box
692ed2226bdSDavid E. Boxconfig IOSF_MBI_DEBUG
693ed2226bdSDavid E. Box	bool "Enable IOSF sideband access through debugfs"
694ed2226bdSDavid E. Box	depends on IOSF_MBI && DEBUG_FS
695a7f7f624SMasahiro Yamada	help
696ed2226bdSDavid E. Box	  Select this option to expose the IOSF sideband access registers (MCR,
697ed2226bdSDavid E. Box	  MDR, MCRX) through debugfs to write and read register information from
698ed2226bdSDavid E. Box	  different units on the SoC. This is most useful for obtaining device
699ed2226bdSDavid E. Box	  state information for debug and analysis. As this is a general access
700ed2226bdSDavid E. Box	  mechanism, users of this option would have specific knowledge of the
701ed2226bdSDavid E. Box	  device they want to access.
702ed2226bdSDavid E. Box
703ed2226bdSDavid E. Box	  If you don't require the option or are in doubt, say N.
704ed2226bdSDavid E. Box
705c5c606d9SRavikiran G Thirumalaiconfig X86_RDC321X
706c5c606d9SRavikiran G Thirumalai	bool "RDC R-321x SoC"
707506f1d07SSam Ravnborg	depends on X86_32
708c5c606d9SRavikiran G Thirumalai	depends on X86_EXTENDED_PLATFORM
709c5c606d9SRavikiran G Thirumalai	select M486
710c5c606d9SRavikiran G Thirumalai	select X86_REBOOTFIXUPS
711a7f7f624SMasahiro Yamada	help
712c5c606d9SRavikiran G Thirumalai	  This option is needed for RDC R-321x system-on-chip, also known
713c5c606d9SRavikiran G Thirumalai	  as R-8610-(G).
714c5c606d9SRavikiran G Thirumalai	  If you don't have one of these chips, you should say N here.
715c5c606d9SRavikiran G Thirumalai
716e0c7ae37SIngo Molnarconfig X86_32_NON_STANDARD
7179c398017SIngo Molnar	bool "Support non-standard 32-bit SMP architectures"
7189c398017SIngo Molnar	depends on X86_32 && SMP
719c5c606d9SRavikiran G Thirumalai	depends on X86_EXTENDED_PLATFORM
720a7f7f624SMasahiro Yamada	help
721b5660ba7SH. Peter Anvin	  This option compiles in the bigsmp and STA2X11 default
722b5660ba7SH. Peter Anvin	  subarchitectures.  It is intended for a generic binary
723b5660ba7SH. Peter Anvin	  kernel. If you select them all, kernel will probe it one by
724b5660ba7SH. Peter Anvin	  one and will fallback to default.
725d49c4288SYinghai Lu
726c5c606d9SRavikiran G Thirumalai# Alphabetically sorted list of Non standard 32 bit platforms
727d49c4288SYinghai Lu
728d949f36fSLinus Torvaldsconfig X86_SUPPORTS_MEMORY_FAILURE
7296fc108a0SJan Beulich	def_bool y
730d949f36fSLinus Torvalds	# MCE code calls memory_failure():
731d949f36fSLinus Torvalds	depends on X86_MCE
732d949f36fSLinus Torvalds	# On 32-bit this adds too big of NODES_SHIFT and we run out of page flags:
733d949f36fSLinus Torvalds	# On 32-bit SPARSEMEM adds too big of SECTIONS_WIDTH:
734d949f36fSLinus Torvalds	depends on X86_64 || !SPARSEMEM
735d949f36fSLinus Torvalds	select ARCH_SUPPORTS_MEMORY_FAILURE
736d949f36fSLinus Torvalds
73783125a3aSAlessandro Rubiniconfig STA2X11
73883125a3aSAlessandro Rubini	bool "STA2X11 Companion Chip Support"
73983125a3aSAlessandro Rubini	depends on X86_32_NON_STANDARD && PCI
74083125a3aSAlessandro Rubini	select SWIOTLB
74183125a3aSAlessandro Rubini	select MFD_STA2X11
7420145071bSLinus Walleij	select GPIOLIB
743a7f7f624SMasahiro Yamada	help
74483125a3aSAlessandro Rubini	  This adds support for boards based on the STA2X11 IO-Hub,
74583125a3aSAlessandro Rubini	  a.k.a. "ConneXt". The chip is used in place of the standard
74683125a3aSAlessandro Rubini	  PC chipset, so all "standard" peripherals are missing. If this
74783125a3aSAlessandro Rubini	  option is selected the kernel will still be able to boot on
74883125a3aSAlessandro Rubini	  standard PC machines.
74983125a3aSAlessandro Rubini
75082148d1dSShérabconfig X86_32_IRIS
75182148d1dSShérab	tristate "Eurobraille/Iris poweroff module"
75282148d1dSShérab	depends on X86_32
753a7f7f624SMasahiro Yamada	help
75482148d1dSShérab	  The Iris machines from EuroBraille do not have APM or ACPI support
75582148d1dSShérab	  to shut themselves down properly.  A special I/O sequence is
75682148d1dSShérab	  needed to do so, which is what this module does at
75782148d1dSShérab	  kernel shutdown.
75882148d1dSShérab
75982148d1dSShérab	  This is only for Iris machines from EuroBraille.
76082148d1dSShérab
76182148d1dSShérab	  If unused, say N.
76282148d1dSShérab
763ae1e9130SIngo Molnarconfig SCHED_OMIT_FRAME_POINTER
7643c2362e6SHarvey Harrison	def_bool y
7653c2362e6SHarvey Harrison	prompt "Single-depth WCHAN output"
766a87d0914SKen Chen	depends on X86
767a7f7f624SMasahiro Yamada	help
768506f1d07SSam Ravnborg	  Calculate simpler /proc/<PID>/wchan values. If this option
769506f1d07SSam Ravnborg	  is disabled then wchan values will recurse back to the
770506f1d07SSam Ravnborg	  caller function. This provides more accurate wchan values,
771506f1d07SSam Ravnborg	  at the expense of slightly more scheduling overhead.
772506f1d07SSam Ravnborg
773506f1d07SSam Ravnborg	  If in doubt, say "Y".
774506f1d07SSam Ravnborg
7756276a074SBorislav Petkovmenuconfig HYPERVISOR_GUEST
7766276a074SBorislav Petkov	bool "Linux guest support"
777a7f7f624SMasahiro Yamada	help
7786276a074SBorislav Petkov	  Say Y here to enable options for running Linux under various hyper-
7796276a074SBorislav Petkov	  visors. This option enables basic hypervisor detection and platform
7806276a074SBorislav Petkov	  setup.
781506f1d07SSam Ravnborg
7826276a074SBorislav Petkov	  If you say N, all options in this submenu will be skipped and
7836276a074SBorislav Petkov	  disabled, and Linux guest support won't be built in.
784506f1d07SSam Ravnborg
7856276a074SBorislav Petkovif HYPERVISOR_GUEST
786506f1d07SSam Ravnborg
787e61bd94aSEduardo Pereira Habkostconfig PARAVIRT
788e61bd94aSEduardo Pereira Habkost	bool "Enable paravirtualization code"
789a0e2bf7cSJuergen Gross	depends on HAVE_STATIC_CALL
790a7f7f624SMasahiro Yamada	help
791e61bd94aSEduardo Pereira Habkost	  This changes the kernel so it can modify itself when it is run
792e61bd94aSEduardo Pereira Habkost	  under a hypervisor, potentially improving performance significantly
793e61bd94aSEduardo Pereira Habkost	  over full virtualization.  However, when run without a hypervisor
794e61bd94aSEduardo Pereira Habkost	  the kernel is theoretically slower and slightly larger.
795e61bd94aSEduardo Pereira Habkost
796c00a280aSJuergen Grossconfig PARAVIRT_XXL
797c00a280aSJuergen Gross	bool
798c00a280aSJuergen Gross
7996276a074SBorislav Petkovconfig PARAVIRT_DEBUG
8006276a074SBorislav Petkov	bool "paravirt-ops debugging"
8016276a074SBorislav Petkov	depends on PARAVIRT && DEBUG_KERNEL
802a7f7f624SMasahiro Yamada	help
8036276a074SBorislav Petkov	  Enable to debug paravirt_ops internals.  Specifically, BUG if
8046276a074SBorislav Petkov	  a paravirt_op is missing when it is called.
8056276a074SBorislav Petkov
806b4ecc126SJeremy Fitzhardingeconfig PARAVIRT_SPINLOCKS
807b4ecc126SJeremy Fitzhardinge	bool "Paravirtualization layer for spinlocks"
8086ea30386SKees Cook	depends on PARAVIRT && SMP
809a7f7f624SMasahiro Yamada	help
810b4ecc126SJeremy Fitzhardinge	  Paravirtualized spinlocks allow a pvops backend to replace the
811b4ecc126SJeremy Fitzhardinge	  spinlock implementation with something virtualization-friendly
812b4ecc126SJeremy Fitzhardinge	  (for example, block the virtual CPU rather than spinning).
813b4ecc126SJeremy Fitzhardinge
8144c4e4f61SRaghavendra K T	  It has a minimal impact on native kernels and gives a nice performance
8154c4e4f61SRaghavendra K T	  benefit on paravirtualized KVM / Xen kernels.
816b4ecc126SJeremy Fitzhardinge
8174c4e4f61SRaghavendra K T	  If you are unsure how to answer this question, answer Y.
818b4ecc126SJeremy Fitzhardinge
819ecca2502SZhao Yakuiconfig X86_HV_CALLBACK_VECTOR
820ecca2502SZhao Yakui	def_bool n
821ecca2502SZhao Yakui
8226276a074SBorislav Petkovsource "arch/x86/xen/Kconfig"
8236276a074SBorislav Petkov
8246276a074SBorislav Petkovconfig KVM_GUEST
8256276a074SBorislav Petkov	bool "KVM Guest support (including kvmclock)"
8266276a074SBorislav Petkov	depends on PARAVIRT
8276276a074SBorislav Petkov	select PARAVIRT_CLOCK
828a1c4423bSMarcelo Tosatti	select ARCH_CPUIDLE_HALTPOLL
829b1d40575SVitaly Kuznetsov	select X86_HV_CALLBACK_VECTOR
8306276a074SBorislav Petkov	default y
831a7f7f624SMasahiro Yamada	help
8326276a074SBorislav Petkov	  This option enables various optimizations for running under the KVM
8336276a074SBorislav Petkov	  hypervisor. It includes a paravirtualized clock, so that instead
8346276a074SBorislav Petkov	  of relying on a PIT (or probably other) emulation by the
8356276a074SBorislav Petkov	  underlying device model, the host provides the guest with
8366276a074SBorislav Petkov	  timing infrastructure such as time of day, and system time
8376276a074SBorislav Petkov
838a1c4423bSMarcelo Tosatticonfig ARCH_CPUIDLE_HALTPOLL
839a1c4423bSMarcelo Tosatti	def_bool n
840a1c4423bSMarcelo Tosatti	prompt "Disable host haltpoll when loading haltpoll driver"
841a1c4423bSMarcelo Tosatti	help
842a1c4423bSMarcelo Tosatti	  If virtualized under KVM, disable host haltpoll.
843a1c4423bSMarcelo Tosatti
8447733607fSMaran Wilsonconfig PVH
8457733607fSMaran Wilson	bool "Support for running PVH guests"
846a7f7f624SMasahiro Yamada	help
8477733607fSMaran Wilson	  This option enables the PVH entry point for guest virtual machines
8487733607fSMaran Wilson	  as specified in the x86/HVM direct boot ABI.
8497733607fSMaran Wilson
8506276a074SBorislav Petkovconfig PARAVIRT_TIME_ACCOUNTING
8516276a074SBorislav Petkov	bool "Paravirtual steal time accounting"
8526276a074SBorislav Petkov	depends on PARAVIRT
853a7f7f624SMasahiro Yamada	help
8546276a074SBorislav Petkov	  Select this option to enable fine granularity task steal time
8556276a074SBorislav Petkov	  accounting. Time spent executing other tasks in parallel with
8566276a074SBorislav Petkov	  the current vCPU is discounted from the vCPU power. To account for
8576276a074SBorislav Petkov	  that, there can be a small performance impact.
8586276a074SBorislav Petkov
8596276a074SBorislav Petkov	  If in doubt, say N here.
8606276a074SBorislav Petkov
8617af192c9SGerd Hoffmannconfig PARAVIRT_CLOCK
8627af192c9SGerd Hoffmann	bool
8637af192c9SGerd Hoffmann
8644a362601SJan Kiszkaconfig JAILHOUSE_GUEST
8654a362601SJan Kiszka	bool "Jailhouse non-root cell support"
866abde587bSArnd Bergmann	depends on X86_64 && PCI
86787e65d05SJan Kiszka	select X86_PM_TIMER
868a7f7f624SMasahiro Yamada	help
8694a362601SJan Kiszka	  This option allows to run Linux as guest in a Jailhouse non-root
8704a362601SJan Kiszka	  cell. You can leave this option disabled if you only want to start
8714a362601SJan Kiszka	  Jailhouse and run Linux afterwards in the root cell.
8724a362601SJan Kiszka
873ec7972c9SZhao Yakuiconfig ACRN_GUEST
874ec7972c9SZhao Yakui	bool "ACRN Guest support"
875ec7972c9SZhao Yakui	depends on X86_64
876498ad393SZhao Yakui	select X86_HV_CALLBACK_VECTOR
877ec7972c9SZhao Yakui	help
878ec7972c9SZhao Yakui	  This option allows to run Linux as guest in the ACRN hypervisor. ACRN is
879ec7972c9SZhao Yakui	  a flexible, lightweight reference open-source hypervisor, built with
880ec7972c9SZhao Yakui	  real-time and safety-criticality in mind. It is built for embedded
881ec7972c9SZhao Yakui	  IOT with small footprint and real-time features. More details can be
882ec7972c9SZhao Yakui	  found in https://projectacrn.org/.
883ec7972c9SZhao Yakui
88459bd54a8SKuppuswamy Sathyanarayananconfig INTEL_TDX_GUEST
88559bd54a8SKuppuswamy Sathyanarayanan	bool "Intel TDX (Trust Domain Extensions) - Guest Support"
88659bd54a8SKuppuswamy Sathyanarayanan	depends on X86_64 && CPU_SUP_INTEL
88759bd54a8SKuppuswamy Sathyanarayanan	depends on X86_X2APIC
88841394e33SKirill A. Shutemov	select ARCH_HAS_CC_PLATFORM
889968b4931SKirill A. Shutemov	select X86_MEM_ENCRYPT
89077a512e3SSean Christopherson	select X86_MCE
89159bd54a8SKuppuswamy Sathyanarayanan	help
89259bd54a8SKuppuswamy Sathyanarayanan	  Support running as a guest under Intel TDX.  Without this support,
89359bd54a8SKuppuswamy Sathyanarayanan	  the guest kernel can not boot or run under TDX.
89459bd54a8SKuppuswamy Sathyanarayanan	  TDX includes memory encryption and integrity capabilities
89559bd54a8SKuppuswamy Sathyanarayanan	  which protect the confidentiality and integrity of guest
89659bd54a8SKuppuswamy Sathyanarayanan	  memory contents and CPU state. TDX guests are protected from
89759bd54a8SKuppuswamy Sathyanarayanan	  some attacks from the VMM.
89859bd54a8SKuppuswamy Sathyanarayanan
8996276a074SBorislav Petkovendif # HYPERVISOR_GUEST
90097349135SJeremy Fitzhardinge
901506f1d07SSam Ravnborgsource "arch/x86/Kconfig.cpu"
902506f1d07SSam Ravnborg
903506f1d07SSam Ravnborgconfig HPET_TIMER
9043c2362e6SHarvey Harrison	def_bool X86_64
905506f1d07SSam Ravnborg	prompt "HPET Timer Support" if X86_32
906a7f7f624SMasahiro Yamada	help
907506f1d07SSam Ravnborg	  Use the IA-PC HPET (High Precision Event Timer) to manage
908506f1d07SSam Ravnborg	  time in preference to the PIT and RTC, if a HPET is
909506f1d07SSam Ravnborg	  present.
910506f1d07SSam Ravnborg	  HPET is the next generation timer replacing legacy 8254s.
911506f1d07SSam Ravnborg	  The HPET provides a stable time base on SMP
912506f1d07SSam Ravnborg	  systems, unlike the TSC, but it is more expensive to access,
9134e7f9df2SMichael S. Tsirkin	  as it is off-chip.  The interface used is documented
9144e7f9df2SMichael S. Tsirkin	  in the HPET spec, revision 1.
915506f1d07SSam Ravnborg
916506f1d07SSam Ravnborg	  You can safely choose Y here.  However, HPET will only be
917506f1d07SSam Ravnborg	  activated if the platform and the BIOS support this feature.
918506f1d07SSam Ravnborg	  Otherwise the 8254 will be used for timing services.
919506f1d07SSam Ravnborg
920506f1d07SSam Ravnborg	  Choose N to continue using the legacy 8254 timer.
921506f1d07SSam Ravnborg
922506f1d07SSam Ravnborgconfig HPET_EMULATE_RTC
9233c2362e6SHarvey Harrison	def_bool y
9243228e1dcSAnand K Mistry	depends on HPET_TIMER && (RTC_DRV_CMOS=m || RTC_DRV_CMOS=y)
925506f1d07SSam Ravnborg
9266a108a14SDavid Rientjes# Mark as expert because too many people got it wrong.
927506f1d07SSam Ravnborg# The code disables itself when not needed.
9287ae9392cSThomas Petazzoniconfig DMI
9297ae9392cSThomas Petazzoni	default y
930cf074402SArd Biesheuvel	select DMI_SCAN_MACHINE_NON_EFI_FALLBACK
9316a108a14SDavid Rientjes	bool "Enable DMI scanning" if EXPERT
932a7f7f624SMasahiro Yamada	help
9337ae9392cSThomas Petazzoni	  Enabled scanning of DMI to identify machine quirks. Say Y
9347ae9392cSThomas Petazzoni	  here unless you have verified that your setup is not
9357ae9392cSThomas Petazzoni	  affected by entries in the DMI blacklist. Required by PNP
9367ae9392cSThomas Petazzoni	  BIOS code.
9377ae9392cSThomas Petazzoni
938506f1d07SSam Ravnborgconfig GART_IOMMU
93938901f1cSAndi Kleen	bool "Old AMD GART IOMMU support"
9402f9237d4SChristoph Hellwig	select DMA_OPS
941a4ce5a48SChristoph Hellwig	select IOMMU_HELPER
942506f1d07SSam Ravnborg	select SWIOTLB
94323ac4ae8SAndreas Herrmann	depends on X86_64 && PCI && AMD_NB
944a7f7f624SMasahiro Yamada	help
945ced3c42cSIngo Molnar	  Provides a driver for older AMD Athlon64/Opteron/Turion/Sempron
946ced3c42cSIngo Molnar	  GART based hardware IOMMUs.
947ced3c42cSIngo Molnar
948ced3c42cSIngo Molnar	  The GART supports full DMA access for devices with 32-bit access
949ced3c42cSIngo Molnar	  limitations, on systems with more than 3 GB. This is usually needed
950ced3c42cSIngo Molnar	  for USB, sound, many IDE/SATA chipsets and some other devices.
951ced3c42cSIngo Molnar
952ced3c42cSIngo Molnar	  Newer systems typically have a modern AMD IOMMU, supported via
953ced3c42cSIngo Molnar	  the CONFIG_AMD_IOMMU=y config option.
954ced3c42cSIngo Molnar
955ced3c42cSIngo Molnar	  In normal configurations this driver is only active when needed:
956ced3c42cSIngo Molnar	  there's more than 3 GB of memory and the system contains a
957ced3c42cSIngo Molnar	  32-bit limited device.
958ced3c42cSIngo Molnar
959ced3c42cSIngo Molnar	  If unsure, say Y.
960506f1d07SSam Ravnborg
9618b766b0fSMichal Suchanekconfig BOOT_VESA_SUPPORT
9628b766b0fSMichal Suchanek	bool
9638b766b0fSMichal Suchanek	help
9648b766b0fSMichal Suchanek	  If true, at least one selected framebuffer driver can take advantage
9658b766b0fSMichal Suchanek	  of VESA video modes set at an early boot stage via the vga= parameter.
9668b766b0fSMichal Suchanek
9671184dc2fSMike Travisconfig MAXSMP
968ddb0c5a6SSamuel Thibault	bool "Enable Maximum number of SMP Processors and NUMA Nodes"
9696ea30386SKees Cook	depends on X86_64 && SMP && DEBUG_KERNEL
97036f5101aSMike Travis	select CPUMASK_OFFSTACK
971a7f7f624SMasahiro Yamada	help
972ddb0c5a6SSamuel Thibault	  Enable maximum number of CPUS and NUMA Nodes for this architecture.
9731184dc2fSMike Travis	  If unsure, say N.
974506f1d07SSam Ravnborg
975aec6487eSIngo Molnar#
976aec6487eSIngo Molnar# The maximum number of CPUs supported:
977aec6487eSIngo Molnar#
978aec6487eSIngo Molnar# The main config value is NR_CPUS, which defaults to NR_CPUS_DEFAULT,
979aec6487eSIngo Molnar# and which can be configured interactively in the
980aec6487eSIngo Molnar# [NR_CPUS_RANGE_BEGIN ... NR_CPUS_RANGE_END] range.
981aec6487eSIngo Molnar#
982aec6487eSIngo Molnar# The ranges are different on 32-bit and 64-bit kernels, depending on
983aec6487eSIngo Molnar# hardware capabilities and scalability features of the kernel.
984aec6487eSIngo Molnar#
985aec6487eSIngo Molnar# ( If MAXSMP is enabled we just use the highest possible value and disable
986aec6487eSIngo Molnar#   interactive configuration. )
987aec6487eSIngo Molnar#
988a0d0bb4dSRandy Dunlap
989aec6487eSIngo Molnarconfig NR_CPUS_RANGE_BEGIN
990a0d0bb4dSRandy Dunlap	int
991aec6487eSIngo Molnar	default NR_CPUS_RANGE_END if MAXSMP
992a0d0bb4dSRandy Dunlap	default    1 if !SMP
993a0d0bb4dSRandy Dunlap	default    2
994a0d0bb4dSRandy Dunlap
995aec6487eSIngo Molnarconfig NR_CPUS_RANGE_END
996a0d0bb4dSRandy Dunlap	int
997a0d0bb4dSRandy Dunlap	depends on X86_32
998aec6487eSIngo Molnar	default   64 if  SMP &&  X86_BIGSMP
999aec6487eSIngo Molnar	default    8 if  SMP && !X86_BIGSMP
1000a0d0bb4dSRandy Dunlap	default    1 if !SMP
1001a0d0bb4dSRandy Dunlap
1002aec6487eSIngo Molnarconfig NR_CPUS_RANGE_END
1003a0d0bb4dSRandy Dunlap	int
1004a0d0bb4dSRandy Dunlap	depends on X86_64
10051edae1aeSScott Wood	default 8192 if  SMP && CPUMASK_OFFSTACK
10061edae1aeSScott Wood	default  512 if  SMP && !CPUMASK_OFFSTACK
1007a0d0bb4dSRandy Dunlap	default    1 if !SMP
1008aec6487eSIngo Molnar
1009aec6487eSIngo Molnarconfig NR_CPUS_DEFAULT
1010aec6487eSIngo Molnar	int
1011aec6487eSIngo Molnar	depends on X86_32
1012aec6487eSIngo Molnar	default   32 if  X86_BIGSMP
1013aec6487eSIngo Molnar	default    8 if  SMP
1014aec6487eSIngo Molnar	default    1 if !SMP
1015aec6487eSIngo Molnar
1016aec6487eSIngo Molnarconfig NR_CPUS_DEFAULT
1017aec6487eSIngo Molnar	int
1018aec6487eSIngo Molnar	depends on X86_64
1019a0d0bb4dSRandy Dunlap	default 8192 if  MAXSMP
1020a0d0bb4dSRandy Dunlap	default   64 if  SMP
1021aec6487eSIngo Molnar	default    1 if !SMP
1022a0d0bb4dSRandy Dunlap
1023506f1d07SSam Ravnborgconfig NR_CPUS
102436f5101aSMike Travis	int "Maximum number of CPUs" if SMP && !MAXSMP
1025aec6487eSIngo Molnar	range NR_CPUS_RANGE_BEGIN NR_CPUS_RANGE_END
1026aec6487eSIngo Molnar	default NR_CPUS_DEFAULT
1027a7f7f624SMasahiro Yamada	help
1028506f1d07SSam Ravnborg	  This allows you to specify the maximum number of CPUs which this
1029bb61ccc7SJosh Boyer	  kernel will support.  If CPUMASK_OFFSTACK is enabled, the maximum
1030cad14bb9SKirill A. Shutemov	  supported value is 8192, otherwise the maximum value is 512.  The
1031506f1d07SSam Ravnborg	  minimum value which makes sense is 2.
1032506f1d07SSam Ravnborg
1033aec6487eSIngo Molnar	  This is purely to save memory: each supported CPU adds about 8KB
1034aec6487eSIngo Molnar	  to the kernel image.
1035506f1d07SSam Ravnborg
103666558b73STim Chenconfig SCHED_CLUSTER
103766558b73STim Chen	bool "Cluster scheduler support"
103866558b73STim Chen	depends on SMP
103966558b73STim Chen	default y
104066558b73STim Chen	help
104166558b73STim Chen	  Cluster scheduler support improves the CPU scheduler's decision
104266558b73STim Chen	  making when dealing with machines that have clusters of CPUs.
104366558b73STim Chen	  Cluster usually means a couple of CPUs which are placed closely
104466558b73STim Chen	  by sharing mid-level caches, last-level cache tags or internal
104566558b73STim Chen	  busses.
104666558b73STim Chen
1047506f1d07SSam Ravnborgconfig SCHED_SMT
1048dbe73364SThomas Gleixner	def_bool y if SMP
1049506f1d07SSam Ravnborg
1050506f1d07SSam Ravnborgconfig SCHED_MC
10513c2362e6SHarvey Harrison	def_bool y
10523c2362e6SHarvey Harrison	prompt "Multi-core scheduler support"
1053c8e56d20SBorislav Petkov	depends on SMP
1054a7f7f624SMasahiro Yamada	help
1055506f1d07SSam Ravnborg	  Multi-core scheduler support improves the CPU scheduler's decision
1056506f1d07SSam Ravnborg	  making when dealing with multi-core CPU chips at a cost of slightly
1057506f1d07SSam Ravnborg	  increased overhead in some places. If unsure say N here.
1058506f1d07SSam Ravnborg
1059de966cf4STim Chenconfig SCHED_MC_PRIO
1060de966cf4STim Chen	bool "CPU core priorities scheduler support"
10610a21fc12SIngo Molnar	depends on SCHED_MC && CPU_SUP_INTEL
10620a21fc12SIngo Molnar	select X86_INTEL_PSTATE
10630a21fc12SIngo Molnar	select CPU_FREQ
1064de966cf4STim Chen	default y
1065a7f7f624SMasahiro Yamada	help
1066de966cf4STim Chen	  Intel Turbo Boost Max Technology 3.0 enabled CPUs have a
1067de966cf4STim Chen	  core ordering determined at manufacturing time, which allows
1068de966cf4STim Chen	  certain cores to reach higher turbo frequencies (when running
1069de966cf4STim Chen	  single threaded workloads) than others.
1070de966cf4STim Chen
1071de966cf4STim Chen	  Enabling this kernel feature teaches the scheduler about
1072de966cf4STim Chen	  the TBM3 (aka ITMT) priority order of the CPU cores and adjusts the
1073de966cf4STim Chen	  scheduler's CPU selection logic accordingly, so that higher
1074de966cf4STim Chen	  overall system performance can be achieved.
1075de966cf4STim Chen
1076de966cf4STim Chen	  This feature will have no effect on CPUs without this feature.
1077de966cf4STim Chen
1078de966cf4STim Chen	  If unsure say Y here.
10795e76b2abSTim Chen
108030b8b006SThomas Gleixnerconfig UP_LATE_INIT
108130b8b006SThomas Gleixner	def_bool y
1082ba360f88SThomas Gleixner	depends on !SMP && X86_LOCAL_APIC
108330b8b006SThomas Gleixner
1084506f1d07SSam Ravnborgconfig X86_UP_APIC
108550849eefSJan Beulich	bool "Local APIC support on uniprocessors" if !PCI_MSI
108650849eefSJan Beulich	default PCI_MSI
108738a1dfdaSBryan O'Donoghue	depends on X86_32 && !SMP && !X86_32_NON_STANDARD
1088a7f7f624SMasahiro Yamada	help
1089506f1d07SSam Ravnborg	  A local APIC (Advanced Programmable Interrupt Controller) is an
1090506f1d07SSam Ravnborg	  integrated interrupt controller in the CPU. If you have a single-CPU
1091506f1d07SSam Ravnborg	  system which has a processor with a local APIC, you can say Y here to
1092506f1d07SSam Ravnborg	  enable and use it. If you say Y here even though your machine doesn't
1093506f1d07SSam Ravnborg	  have a local APIC, then the kernel will still run with no slowdown at
1094506f1d07SSam Ravnborg	  all. The local APIC supports CPU-generated self-interrupts (timer,
1095506f1d07SSam Ravnborg	  performance counters), and the NMI watchdog which detects hard
1096506f1d07SSam Ravnborg	  lockups.
1097506f1d07SSam Ravnborg
1098506f1d07SSam Ravnborgconfig X86_UP_IOAPIC
1099506f1d07SSam Ravnborg	bool "IO-APIC support on uniprocessors"
1100506f1d07SSam Ravnborg	depends on X86_UP_APIC
1101a7f7f624SMasahiro Yamada	help
1102506f1d07SSam Ravnborg	  An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an
1103506f1d07SSam Ravnborg	  SMP-capable replacement for PC-style interrupt controllers. Most
1104506f1d07SSam Ravnborg	  SMP systems and many recent uniprocessor systems have one.
1105506f1d07SSam Ravnborg
1106506f1d07SSam Ravnborg	  If you have a single-CPU system with an IO-APIC, you can say Y here
1107506f1d07SSam Ravnborg	  to use it. If you say Y here even though your machine doesn't have
1108506f1d07SSam Ravnborg	  an IO-APIC, then the kernel will still run with no slowdown at all.
1109506f1d07SSam Ravnborg
1110506f1d07SSam Ravnborgconfig X86_LOCAL_APIC
11113c2362e6SHarvey Harrison	def_bool y
11120dbc6078SThomas Petazzoni	depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC || PCI_MSI
1113b5dc8e6cSJiang Liu	select IRQ_DOMAIN_HIERARCHY
111452f518a3SJiang Liu	select PCI_MSI_IRQ_DOMAIN if PCI_MSI
1115506f1d07SSam Ravnborg
1116506f1d07SSam Ravnborgconfig X86_IO_APIC
1117b1da1e71SJan Beulich	def_bool y
1118b1da1e71SJan Beulich	depends on X86_LOCAL_APIC || X86_UP_IOAPIC
1119506f1d07SSam Ravnborg
112041b9eb26SStefan Assmannconfig X86_REROUTE_FOR_BROKEN_BOOT_IRQS
112141b9eb26SStefan Assmann	bool "Reroute for broken boot IRQs"
112241b9eb26SStefan Assmann	depends on X86_IO_APIC
1123a7f7f624SMasahiro Yamada	help
112441b9eb26SStefan Assmann	  This option enables a workaround that fixes a source of
112541b9eb26SStefan Assmann	  spurious interrupts. This is recommended when threaded
112641b9eb26SStefan Assmann	  interrupt handling is used on systems where the generation of
112741b9eb26SStefan Assmann	  superfluous "boot interrupts" cannot be disabled.
112841b9eb26SStefan Assmann
112941b9eb26SStefan Assmann	  Some chipsets generate a legacy INTx "boot IRQ" when the IRQ
113041b9eb26SStefan Assmann	  entry in the chipset's IO-APIC is masked (as, e.g. the RT
113141b9eb26SStefan Assmann	  kernel does during interrupt handling). On chipsets where this
113241b9eb26SStefan Assmann	  boot IRQ generation cannot be disabled, this workaround keeps
113341b9eb26SStefan Assmann	  the original IRQ line masked so that only the equivalent "boot
113441b9eb26SStefan Assmann	  IRQ" is delivered to the CPUs. The workaround also tells the
113541b9eb26SStefan Assmann	  kernel to set up the IRQ handler on the boot IRQ line. In this
113641b9eb26SStefan Assmann	  way only one interrupt is delivered to the kernel. Otherwise
113741b9eb26SStefan Assmann	  the spurious second interrupt may cause the kernel to bring
113841b9eb26SStefan Assmann	  down (vital) interrupt lines.
113941b9eb26SStefan Assmann
114041b9eb26SStefan Assmann	  Only affects "broken" chipsets. Interrupt sharing may be
114141b9eb26SStefan Assmann	  increased on these systems.
114241b9eb26SStefan Assmann
1143506f1d07SSam Ravnborgconfig X86_MCE
1144bab9bc65SAndi Kleen	bool "Machine Check / overheating reporting"
1145648ed940SChen, Gong	select GENERIC_ALLOCATOR
1146e57dbaf7SBorislav Petkov	default y
1147a7f7f624SMasahiro Yamada	help
1148bab9bc65SAndi Kleen	  Machine Check support allows the processor to notify the
1149bab9bc65SAndi Kleen	  kernel if it detects a problem (e.g. overheating, data corruption).
1150506f1d07SSam Ravnborg	  The action the kernel takes depends on the severity of the problem,
1151bab9bc65SAndi Kleen	  ranging from warning messages to halting the machine.
11524efc0670SAndi Kleen
11535de97c9fSTony Luckconfig X86_MCELOG_LEGACY
11545de97c9fSTony Luck	bool "Support for deprecated /dev/mcelog character device"
11555de97c9fSTony Luck	depends on X86_MCE
1156a7f7f624SMasahiro Yamada	help
11575de97c9fSTony Luck	  Enable support for /dev/mcelog which is needed by the old mcelog
11585de97c9fSTony Luck	  userspace logging daemon. Consider switching to the new generation
11595de97c9fSTony Luck	  rasdaemon solution.
11605de97c9fSTony Luck
1161506f1d07SSam Ravnborgconfig X86_MCE_INTEL
11623c2362e6SHarvey Harrison	def_bool y
11633c2362e6SHarvey Harrison	prompt "Intel MCE features"
1164c1ebf835SAndi Kleen	depends on X86_MCE && X86_LOCAL_APIC
1165a7f7f624SMasahiro Yamada	help
1166506f1d07SSam Ravnborg	  Additional support for intel specific MCE features such as
1167506f1d07SSam Ravnborg	  the thermal monitor.
1168506f1d07SSam Ravnborg
1169506f1d07SSam Ravnborgconfig X86_MCE_AMD
11703c2362e6SHarvey Harrison	def_bool y
11713c2362e6SHarvey Harrison	prompt "AMD MCE features"
1172f5382de9SYazen Ghannam	depends on X86_MCE && X86_LOCAL_APIC && AMD_NB
1173a7f7f624SMasahiro Yamada	help
1174506f1d07SSam Ravnborg	  Additional support for AMD specific MCE features such as
1175506f1d07SSam Ravnborg	  the DRAM Error Threshold.
1176506f1d07SSam Ravnborg
11774efc0670SAndi Kleenconfig X86_ANCIENT_MCE
11786fc108a0SJan Beulich	bool "Support for old Pentium 5 / WinChip machine checks"
1179c31d9633SAndi Kleen	depends on X86_32 && X86_MCE
1180a7f7f624SMasahiro Yamada	help
11814efc0670SAndi Kleen	  Include support for machine check handling on old Pentium 5 or WinChip
11825065a706SMasanari Iida	  systems. These typically need to be enabled explicitly on the command
11834efc0670SAndi Kleen	  line.
11844efc0670SAndi Kleen
1185b2762686SAndi Kleenconfig X86_MCE_THRESHOLD
1186b2762686SAndi Kleen	depends on X86_MCE_AMD || X86_MCE_INTEL
11876fc108a0SJan Beulich	def_bool y
1188b2762686SAndi Kleen
1189ea149b36SAndi Kleenconfig X86_MCE_INJECT
1190bc8e80d5SBorislav Petkov	depends on X86_MCE && X86_LOCAL_APIC && DEBUG_FS
1191ea149b36SAndi Kleen	tristate "Machine check injector support"
1192a7f7f624SMasahiro Yamada	help
1193ea149b36SAndi Kleen	  Provide support for injecting machine checks for testing purposes.
1194ea149b36SAndi Kleen	  If you don't know what a machine check is and you don't do kernel
1195ea149b36SAndi Kleen	  QA it is safe to say n.
1196ea149b36SAndi Kleen
119707dc900eSPeter Zijlstrasource "arch/x86/events/Kconfig"
1198e633c65aSKan Liang
11995aef51c3SAndy Lutomirskiconfig X86_LEGACY_VM86
12001e642812SIngo Molnar	bool "Legacy VM86 support"
1201506f1d07SSam Ravnborg	depends on X86_32
1202a7f7f624SMasahiro Yamada	help
12035aef51c3SAndy Lutomirski	  This option allows user programs to put the CPU into V8086
12045aef51c3SAndy Lutomirski	  mode, which is an 80286-era approximation of 16-bit real mode.
12055aef51c3SAndy Lutomirski
12065aef51c3SAndy Lutomirski	  Some very old versions of X and/or vbetool require this option
12075aef51c3SAndy Lutomirski	  for user mode setting.  Similarly, DOSEMU will use it if
12085aef51c3SAndy Lutomirski	  available to accelerate real mode DOS programs.  However, any
12095aef51c3SAndy Lutomirski	  recent version of DOSEMU, X, or vbetool should be fully
12105aef51c3SAndy Lutomirski	  functional even without kernel VM86 support, as they will all
12111e642812SIngo Molnar	  fall back to software emulation. Nevertheless, if you are using
12121e642812SIngo Molnar	  a 16-bit DOS program where 16-bit performance matters, vm86
12131e642812SIngo Molnar	  mode might be faster than emulation and you might want to
12141e642812SIngo Molnar	  enable this option.
12155aef51c3SAndy Lutomirski
12161e642812SIngo Molnar	  Note that any app that works on a 64-bit kernel is unlikely to
12171e642812SIngo Molnar	  need this option, as 64-bit kernels don't, and can't, support
12181e642812SIngo Molnar	  V8086 mode. This option is also unrelated to 16-bit protected
12191e642812SIngo Molnar	  mode and is not needed to run most 16-bit programs under Wine.
12205aef51c3SAndy Lutomirski
12211e642812SIngo Molnar	  Enabling this option increases the complexity of the kernel
12221e642812SIngo Molnar	  and slows down exception handling a tiny bit.
12235aef51c3SAndy Lutomirski
12241e642812SIngo Molnar	  If unsure, say N here.
12255aef51c3SAndy Lutomirski
12265aef51c3SAndy Lutomirskiconfig VM86
12275aef51c3SAndy Lutomirski	bool
12285aef51c3SAndy Lutomirski	default X86_LEGACY_VM86
122934273f41SH. Peter Anvin
123034273f41SH. Peter Anvinconfig X86_16BIT
123134273f41SH. Peter Anvin	bool "Enable support for 16-bit segments" if EXPERT
123234273f41SH. Peter Anvin	default y
1233a5b9e5a2SAndy Lutomirski	depends on MODIFY_LDT_SYSCALL
1234a7f7f624SMasahiro Yamada	help
123534273f41SH. Peter Anvin	  This option is required by programs like Wine to run 16-bit
123634273f41SH. Peter Anvin	  protected mode legacy code on x86 processors.  Disabling
123734273f41SH. Peter Anvin	  this option saves about 300 bytes on i386, or around 6K text
123834273f41SH. Peter Anvin	  plus 16K runtime memory on x86-64,
123934273f41SH. Peter Anvin
124034273f41SH. Peter Anvinconfig X86_ESPFIX32
124134273f41SH. Peter Anvin	def_bool y
124234273f41SH. Peter Anvin	depends on X86_16BIT && X86_32
1243506f1d07SSam Ravnborg
1244197725deSH. Peter Anvinconfig X86_ESPFIX64
1245197725deSH. Peter Anvin	def_bool y
124634273f41SH. Peter Anvin	depends on X86_16BIT && X86_64
1247506f1d07SSam Ravnborg
12481ad83c85SAndy Lutomirskiconfig X86_VSYSCALL_EMULATION
12491ad83c85SAndy Lutomirski	bool "Enable vsyscall emulation" if EXPERT
12501ad83c85SAndy Lutomirski	default y
12511ad83c85SAndy Lutomirski	depends on X86_64
1252a7f7f624SMasahiro Yamada	help
12531ad83c85SAndy Lutomirski	  This enables emulation of the legacy vsyscall page.  Disabling
12541ad83c85SAndy Lutomirski	  it is roughly equivalent to booting with vsyscall=none, except
12551ad83c85SAndy Lutomirski	  that it will also disable the helpful warning if a program
12561ad83c85SAndy Lutomirski	  tries to use a vsyscall.  With this option set to N, offending
12571ad83c85SAndy Lutomirski	  programs will just segfault, citing addresses of the form
12581ad83c85SAndy Lutomirski	  0xffffffffff600?00.
12591ad83c85SAndy Lutomirski
12601ad83c85SAndy Lutomirski	  This option is required by many programs built before 2013, and
12611ad83c85SAndy Lutomirski	  care should be used even with newer programs if set to N.
12621ad83c85SAndy Lutomirski
12631ad83c85SAndy Lutomirski	  Disabling this option saves about 7K of kernel size and
12641ad83c85SAndy Lutomirski	  possibly 4K of additional runtime pagetable memory.
12651ad83c85SAndy Lutomirski
1266111e7b15SThomas Gleixnerconfig X86_IOPL_IOPERM
1267111e7b15SThomas Gleixner	bool "IOPERM and IOPL Emulation"
1268a24ca997SThomas Gleixner	default y
1269a7f7f624SMasahiro Yamada	help
1270111e7b15SThomas Gleixner	  This enables the ioperm() and iopl() syscalls which are necessary
1271111e7b15SThomas Gleixner	  for legacy applications.
1272111e7b15SThomas Gleixner
1273c8137aceSThomas Gleixner	  Legacy IOPL support is an overbroad mechanism which allows user
1274c8137aceSThomas Gleixner	  space aside of accessing all 65536 I/O ports also to disable
1275c8137aceSThomas Gleixner	  interrupts. To gain this access the caller needs CAP_SYS_RAWIO
1276c8137aceSThomas Gleixner	  capabilities and permission from potentially active security
1277c8137aceSThomas Gleixner	  modules.
1278c8137aceSThomas Gleixner
1279c8137aceSThomas Gleixner	  The emulation restricts the functionality of the syscall to
1280c8137aceSThomas Gleixner	  only allowing the full range I/O port access, but prevents the
1281a24ca997SThomas Gleixner	  ability to disable interrupts from user space which would be
1282a24ca997SThomas Gleixner	  granted if the hardware IOPL mechanism would be used.
1283c8137aceSThomas Gleixner
1284506f1d07SSam Ravnborgconfig TOSHIBA
1285506f1d07SSam Ravnborg	tristate "Toshiba Laptop support"
1286506f1d07SSam Ravnborg	depends on X86_32
1287a7f7f624SMasahiro Yamada	help
1288506f1d07SSam Ravnborg	  This adds a driver to safely access the System Management Mode of
1289506f1d07SSam Ravnborg	  the CPU on Toshiba portables with a genuine Toshiba BIOS. It does
1290506f1d07SSam Ravnborg	  not work on models with a Phoenix BIOS. The System Management Mode
1291506f1d07SSam Ravnborg	  is used to set the BIOS and power saving options on Toshiba portables.
1292506f1d07SSam Ravnborg
1293506f1d07SSam Ravnborg	  For information on utilities to make use of this driver see the
1294506f1d07SSam Ravnborg	  Toshiba Linux utilities web site at:
1295506f1d07SSam Ravnborg	  <http://www.buzzard.org.uk/toshiba/>.
1296506f1d07SSam Ravnborg
1297506f1d07SSam Ravnborg	  Say Y if you intend to run this kernel on a Toshiba portable.
1298506f1d07SSam Ravnborg	  Say N otherwise.
1299506f1d07SSam Ravnborg
1300506f1d07SSam Ravnborgconfig X86_REBOOTFIXUPS
13019ba16087SJan Beulich	bool "Enable X86 board specific fixups for reboot"
13029ba16087SJan Beulich	depends on X86_32
1303a7f7f624SMasahiro Yamada	help
1304506f1d07SSam Ravnborg	  This enables chipset and/or board specific fixups to be done
1305506f1d07SSam Ravnborg	  in order to get reboot to work correctly. This is only needed on
1306506f1d07SSam Ravnborg	  some combinations of hardware and BIOS. The symptom, for which
1307506f1d07SSam Ravnborg	  this config is intended, is when reboot ends with a stalled/hung
1308506f1d07SSam Ravnborg	  system.
1309506f1d07SSam Ravnborg
1310506f1d07SSam Ravnborg	  Currently, the only fixup is for the Geode machines using
13115e3a77e9SFlorian Fainelli	  CS5530A and CS5536 chipsets and the RDC R-321x SoC.
1312506f1d07SSam Ravnborg
1313506f1d07SSam Ravnborg	  Say Y if you want to enable the fixup. Currently, it's safe to
1314506f1d07SSam Ravnborg	  enable this option even if you don't need it.
1315506f1d07SSam Ravnborg	  Say N otherwise.
1316506f1d07SSam Ravnborg
1317506f1d07SSam Ravnborgconfig MICROCODE
13189a2bc335SBorislav Petkov	bool "CPU microcode loading support"
13199a2bc335SBorislav Petkov	default y
132080030e3dSBorislav Petkov	depends on CPU_SUP_AMD || CPU_SUP_INTEL
1321a7f7f624SMasahiro Yamada	help
1322506f1d07SSam Ravnborg	  If you say Y here, you will be able to update the microcode on
13235f9c01aaSBorislav Petkov	  Intel and AMD processors. The Intel support is for the IA32 family,
13245f9c01aaSBorislav Petkov	  e.g. Pentium Pro, Pentium II, Pentium III, Pentium 4, Xeon etc. The
13255f9c01aaSBorislav Petkov	  AMD support is for families 0x10 and later. You will obviously need
13265f9c01aaSBorislav Petkov	  the actual microcode binary data itself which is not shipped with
13275f9c01aaSBorislav Petkov	  the Linux kernel.
1328506f1d07SSam Ravnborg
13295f9c01aaSBorislav Petkov	  The preferred method to load microcode from a detached initrd is described
1330cb1aaebeSMauro Carvalho Chehab	  in Documentation/x86/microcode.rst. For that you need to enable
13315f9c01aaSBorislav Petkov	  CONFIG_BLK_DEV_INITRD in order for the loader to be able to scan the
13325f9c01aaSBorislav Petkov	  initrd for microcode blobs.
1333506f1d07SSam Ravnborg
1334c508c46eSBenjamin Gilbert	  In addition, you can build the microcode into the kernel. For that you
1335c508c46eSBenjamin Gilbert	  need to add the vendor-supplied microcode to the CONFIG_EXTRA_FIRMWARE
1336c508c46eSBenjamin Gilbert	  config option.
1337506f1d07SSam Ravnborg
13388d86f390SPeter Orubaconfig MICROCODE_INTEL
1339e43f6e67SBorislav Petkov	bool "Intel microcode loading support"
13409c55d99eSBorislav Petkov	depends on CPU_SUP_INTEL && MICROCODE
13418d86f390SPeter Oruba	default MICROCODE
1342a7f7f624SMasahiro Yamada	help
13438d86f390SPeter Oruba	  This options enables microcode patch loading support for Intel
13448d86f390SPeter Oruba	  processors.
13458d86f390SPeter Oruba
1346b8989db9SAlan	  For the current Intel microcode data package go to
1347b8989db9SAlan	  <https://downloadcenter.intel.com> and search for
1348b8989db9SAlan	  'Linux Processor Microcode Data File'.
13498d86f390SPeter Oruba
135080cc9f10SPeter Orubaconfig MICROCODE_AMD
1351e43f6e67SBorislav Petkov	bool "AMD microcode loading support"
13529c55d99eSBorislav Petkov	depends on CPU_SUP_AMD && MICROCODE
1353a7f7f624SMasahiro Yamada	help
135480cc9f10SPeter Oruba	  If you select this option, microcode patch loading support for AMD
135580cc9f10SPeter Oruba	  processors will be enabled.
135680cc9f10SPeter Oruba
1357a77a94f8SBorislav Petkovconfig MICROCODE_LATE_LOADING
1358a77a94f8SBorislav Petkov	bool "Late microcode loading (DANGEROUS)"
1359c02f48e0SBorislav Petkov	default n
1360506f1d07SSam Ravnborg	depends on MICROCODE
1361a7f7f624SMasahiro Yamada	help
1362a77a94f8SBorislav Petkov	  Loading microcode late, when the system is up and executing instructions
1363a77a94f8SBorislav Petkov	  is a tricky business and should be avoided if possible. Just the sequence
1364a77a94f8SBorislav Petkov	  of synchronizing all cores and SMT threads is one fragile dance which does
1365a77a94f8SBorislav Petkov	  not guarantee that cores might not softlock after the loading. Therefore,
1366a77a94f8SBorislav Petkov	  use this at your own risk. Late loading taints the kernel too.
1367506f1d07SSam Ravnborg
1368506f1d07SSam Ravnborgconfig X86_MSR
1369506f1d07SSam Ravnborg	tristate "/dev/cpu/*/msr - Model-specific register support"
1370a7f7f624SMasahiro Yamada	help
1371506f1d07SSam Ravnborg	  This device gives privileged processes access to the x86
1372506f1d07SSam Ravnborg	  Model-Specific Registers (MSRs).  It is a character device with
1373506f1d07SSam Ravnborg	  major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr.
1374506f1d07SSam Ravnborg	  MSR accesses are directed to a specific CPU on multi-processor
1375506f1d07SSam Ravnborg	  systems.
1376506f1d07SSam Ravnborg
1377506f1d07SSam Ravnborgconfig X86_CPUID
1378506f1d07SSam Ravnborg	tristate "/dev/cpu/*/cpuid - CPU information support"
1379a7f7f624SMasahiro Yamada	help
1380506f1d07SSam Ravnborg	  This device gives processes access to the x86 CPUID instruction to
1381506f1d07SSam Ravnborg	  be executed on a specific processor.  It is a character device
1382506f1d07SSam Ravnborg	  with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to
1383506f1d07SSam Ravnborg	  /dev/cpu/31/cpuid.
1384506f1d07SSam Ravnborg
1385506f1d07SSam Ravnborgchoice
1386506f1d07SSam Ravnborg	prompt "High Memory Support"
13876fc108a0SJan Beulich	default HIGHMEM4G
1388506f1d07SSam Ravnborg	depends on X86_32
1389506f1d07SSam Ravnborg
1390506f1d07SSam Ravnborgconfig NOHIGHMEM
1391506f1d07SSam Ravnborg	bool "off"
1392a7f7f624SMasahiro Yamada	help
1393506f1d07SSam Ravnborg	  Linux can use up to 64 Gigabytes of physical memory on x86 systems.
1394506f1d07SSam Ravnborg	  However, the address space of 32-bit x86 processors is only 4
1395506f1d07SSam Ravnborg	  Gigabytes large. That means that, if you have a large amount of
1396506f1d07SSam Ravnborg	  physical memory, not all of it can be "permanently mapped" by the
1397506f1d07SSam Ravnborg	  kernel. The physical memory that's not permanently mapped is called
1398506f1d07SSam Ravnborg	  "high memory".
1399506f1d07SSam Ravnborg
1400506f1d07SSam Ravnborg	  If you are compiling a kernel which will never run on a machine with
1401506f1d07SSam Ravnborg	  more than 1 Gigabyte total physical RAM, answer "off" here (default
1402506f1d07SSam Ravnborg	  choice and suitable for most users). This will result in a "3GB/1GB"
1403506f1d07SSam Ravnborg	  split: 3GB are mapped so that each process sees a 3GB virtual memory
1404506f1d07SSam Ravnborg	  space and the remaining part of the 4GB virtual memory space is used
1405506f1d07SSam Ravnborg	  by the kernel to permanently map as much physical memory as
1406506f1d07SSam Ravnborg	  possible.
1407506f1d07SSam Ravnborg
1408506f1d07SSam Ravnborg	  If the machine has between 1 and 4 Gigabytes physical RAM, then
1409506f1d07SSam Ravnborg	  answer "4GB" here.
1410506f1d07SSam Ravnborg
1411506f1d07SSam Ravnborg	  If more than 4 Gigabytes is used then answer "64GB" here. This
1412506f1d07SSam Ravnborg	  selection turns Intel PAE (Physical Address Extension) mode on.
1413506f1d07SSam Ravnborg	  PAE implements 3-level paging on IA32 processors. PAE is fully
1414506f1d07SSam Ravnborg	  supported by Linux, PAE mode is implemented on all recent Intel
1415506f1d07SSam Ravnborg	  processors (Pentium Pro and better). NOTE: If you say "64GB" here,
1416506f1d07SSam Ravnborg	  then the kernel will not boot on CPUs that don't support PAE!
1417506f1d07SSam Ravnborg
1418506f1d07SSam Ravnborg	  The actual amount of total physical memory will either be
1419506f1d07SSam Ravnborg	  auto detected or can be forced by using a kernel command line option
1420506f1d07SSam Ravnborg	  such as "mem=256M". (Try "man bootparam" or see the documentation of
1421506f1d07SSam Ravnborg	  your boot loader (lilo or loadlin) about how to pass options to the
1422506f1d07SSam Ravnborg	  kernel at boot time.)
1423506f1d07SSam Ravnborg
1424506f1d07SSam Ravnborg	  If unsure, say "off".
1425506f1d07SSam Ravnborg
1426506f1d07SSam Ravnborgconfig HIGHMEM4G
1427506f1d07SSam Ravnborg	bool "4GB"
1428a7f7f624SMasahiro Yamada	help
1429506f1d07SSam Ravnborg	  Select this if you have a 32-bit processor and between 1 and 4
1430506f1d07SSam Ravnborg	  gigabytes of physical RAM.
1431506f1d07SSam Ravnborg
1432506f1d07SSam Ravnborgconfig HIGHMEM64G
1433506f1d07SSam Ravnborg	bool "64GB"
1434225bac2dSLukas Bulwahn	depends on !M486SX && !M486 && !M586 && !M586TSC && !M586MMX && !MGEODE_LX && !MGEODEGX1 && !MCYRIXIII && !MELAN && !MWINCHIPC6 && !MWINCHIP3D && !MK6
1435506f1d07SSam Ravnborg	select X86_PAE
1436a7f7f624SMasahiro Yamada	help
1437506f1d07SSam Ravnborg	  Select this if you have a 32-bit processor and more than 4
1438506f1d07SSam Ravnborg	  gigabytes of physical RAM.
1439506f1d07SSam Ravnborg
1440506f1d07SSam Ravnborgendchoice
1441506f1d07SSam Ravnborg
1442506f1d07SSam Ravnborgchoice
14436a108a14SDavid Rientjes	prompt "Memory split" if EXPERT
1444506f1d07SSam Ravnborg	default VMSPLIT_3G
1445506f1d07SSam Ravnborg	depends on X86_32
1446a7f7f624SMasahiro Yamada	help
1447506f1d07SSam Ravnborg	  Select the desired split between kernel and user memory.
1448506f1d07SSam Ravnborg
1449506f1d07SSam Ravnborg	  If the address range available to the kernel is less than the
1450506f1d07SSam Ravnborg	  physical memory installed, the remaining memory will be available
1451506f1d07SSam Ravnborg	  as "high memory". Accessing high memory is a little more costly
1452506f1d07SSam Ravnborg	  than low memory, as it needs to be mapped into the kernel first.
1453506f1d07SSam Ravnborg	  Note that increasing the kernel address space limits the range
1454506f1d07SSam Ravnborg	  available to user programs, making the address space there
1455506f1d07SSam Ravnborg	  tighter.  Selecting anything other than the default 3G/1G split
1456506f1d07SSam Ravnborg	  will also likely make your kernel incompatible with binary-only
1457506f1d07SSam Ravnborg	  kernel modules.
1458506f1d07SSam Ravnborg
1459506f1d07SSam Ravnborg	  If you are not absolutely sure what you are doing, leave this
1460506f1d07SSam Ravnborg	  option alone!
1461506f1d07SSam Ravnborg
1462506f1d07SSam Ravnborg	config VMSPLIT_3G
1463506f1d07SSam Ravnborg		bool "3G/1G user/kernel split"
1464506f1d07SSam Ravnborg	config VMSPLIT_3G_OPT
1465506f1d07SSam Ravnborg		depends on !X86_PAE
1466506f1d07SSam Ravnborg		bool "3G/1G user/kernel split (for full 1G low memory)"
1467506f1d07SSam Ravnborg	config VMSPLIT_2G
1468506f1d07SSam Ravnborg		bool "2G/2G user/kernel split"
1469506f1d07SSam Ravnborg	config VMSPLIT_2G_OPT
1470506f1d07SSam Ravnborg		depends on !X86_PAE
1471506f1d07SSam Ravnborg		bool "2G/2G user/kernel split (for full 2G low memory)"
1472506f1d07SSam Ravnborg	config VMSPLIT_1G
1473506f1d07SSam Ravnborg		bool "1G/3G user/kernel split"
1474506f1d07SSam Ravnborgendchoice
1475506f1d07SSam Ravnborg
1476506f1d07SSam Ravnborgconfig PAGE_OFFSET
1477506f1d07SSam Ravnborg	hex
1478506f1d07SSam Ravnborg	default 0xB0000000 if VMSPLIT_3G_OPT
1479506f1d07SSam Ravnborg	default 0x80000000 if VMSPLIT_2G
1480506f1d07SSam Ravnborg	default 0x78000000 if VMSPLIT_2G_OPT
1481506f1d07SSam Ravnborg	default 0x40000000 if VMSPLIT_1G
1482506f1d07SSam Ravnborg	default 0xC0000000
1483506f1d07SSam Ravnborg	depends on X86_32
1484506f1d07SSam Ravnborg
1485506f1d07SSam Ravnborgconfig HIGHMEM
14863c2362e6SHarvey Harrison	def_bool y
1487506f1d07SSam Ravnborg	depends on X86_32 && (HIGHMEM64G || HIGHMEM4G)
1488506f1d07SSam Ravnborg
1489506f1d07SSam Ravnborgconfig X86_PAE
14909ba16087SJan Beulich	bool "PAE (Physical Address Extension) Support"
1491506f1d07SSam Ravnborg	depends on X86_32 && !HIGHMEM4G
1492d4a451d5SChristoph Hellwig	select PHYS_ADDR_T_64BIT
14939d99c712SChristian Melki	select SWIOTLB
1494a7f7f624SMasahiro Yamada	help
1495506f1d07SSam Ravnborg	  PAE is required for NX support, and furthermore enables
1496506f1d07SSam Ravnborg	  larger swapspace support for non-overcommit purposes. It
1497506f1d07SSam Ravnborg	  has the cost of more pagetable lookup overhead, and also
1498506f1d07SSam Ravnborg	  consumes more pagetable space per process.
1499506f1d07SSam Ravnborg
150077ef56e4SKirill A. Shutemovconfig X86_5LEVEL
150177ef56e4SKirill A. Shutemov	bool "Enable 5-level page tables support"
150218ec1eafSKirill A. Shutemov	default y
1503eedb92abSKirill A. Shutemov	select DYNAMIC_MEMORY_LAYOUT
1504162434e7SKirill A. Shutemov	select SPARSEMEM_VMEMMAP
150577ef56e4SKirill A. Shutemov	depends on X86_64
1506a7f7f624SMasahiro Yamada	help
150777ef56e4SKirill A. Shutemov	  5-level paging enables access to larger address space:
150877ef56e4SKirill A. Shutemov	  upto 128 PiB of virtual address space and 4 PiB of
150977ef56e4SKirill A. Shutemov	  physical address space.
151077ef56e4SKirill A. Shutemov
151177ef56e4SKirill A. Shutemov	  It will be supported by future Intel CPUs.
151277ef56e4SKirill A. Shutemov
15136657fca0SKirill A. Shutemov	  A kernel with the option enabled can be booted on machines that
15146657fca0SKirill A. Shutemov	  support 4- or 5-level paging.
151577ef56e4SKirill A. Shutemov
1516cb1aaebeSMauro Carvalho Chehab	  See Documentation/x86/x86_64/5level-paging.rst for more
151777ef56e4SKirill A. Shutemov	  information.
151877ef56e4SKirill A. Shutemov
151977ef56e4SKirill A. Shutemov	  Say N if unsure.
152077ef56e4SKirill A. Shutemov
152110971ab2SIngo Molnarconfig X86_DIRECT_GBPAGES
1522e5008abeSLuis R. Rodriguez	def_bool y
15232e1da13fSVlastimil Babka	depends on X86_64
1524a7f7f624SMasahiro Yamada	help
152510971ab2SIngo Molnar	  Certain kernel features effectively disable kernel
152610971ab2SIngo Molnar	  linear 1 GB mappings (even if the CPU otherwise
152710971ab2SIngo Molnar	  supports them), so don't confuse the user by printing
152810971ab2SIngo Molnar	  that we have them enabled.
15299e899816SNick Piggin
15305c280cf6SThomas Gleixnerconfig X86_CPA_STATISTICS
15315c280cf6SThomas Gleixner	bool "Enable statistic for Change Page Attribute"
15325c280cf6SThomas Gleixner	depends on DEBUG_FS
1533a7f7f624SMasahiro Yamada	help
1534b75baaf3SIngo Molnar	  Expose statistics about the Change Page Attribute mechanism, which
1535a943245aSColin Ian King	  helps to determine the effectiveness of preserving large and huge
15365c280cf6SThomas Gleixner	  page mappings when mapping protections are changed.
15375c280cf6SThomas Gleixner
153820f07a04SKirill A. Shutemovconfig X86_MEM_ENCRYPT
153920f07a04SKirill A. Shutemov	select ARCH_HAS_FORCE_DMA_UNENCRYPTED
154020f07a04SKirill A. Shutemov	select DYNAMIC_PHYSICAL_MASK
154120f07a04SKirill A. Shutemov	def_bool n
154220f07a04SKirill A. Shutemov
15437744ccdbSTom Lendackyconfig AMD_MEM_ENCRYPT
15447744ccdbSTom Lendacky	bool "AMD Secure Memory Encryption (SME) support"
15457744ccdbSTom Lendacky	depends on X86_64 && CPU_SUP_AMD
154682fef0adSDavid Rientjes	select DMA_COHERENT_POOL
1547ce9084baSArd Biesheuvel	select ARCH_USE_MEMREMAP_PROT
1548597cfe48SJoerg Roedel	select INSTRUCTION_DECODER
1549aa5a4611STom Lendacky	select ARCH_HAS_CC_PLATFORM
155020f07a04SKirill A. Shutemov	select X86_MEM_ENCRYPT
1551a7f7f624SMasahiro Yamada	help
15527744ccdbSTom Lendacky	  Say yes to enable support for the encryption of system memory.
15537744ccdbSTom Lendacky	  This requires an AMD processor that supports Secure Memory
15547744ccdbSTom Lendacky	  Encryption (SME).
15557744ccdbSTom Lendacky
15567744ccdbSTom Lendackyconfig AMD_MEM_ENCRYPT_ACTIVE_BY_DEFAULT
15577744ccdbSTom Lendacky	bool "Activate AMD Secure Memory Encryption (SME) by default"
15587744ccdbSTom Lendacky	depends on AMD_MEM_ENCRYPT
1559a7f7f624SMasahiro Yamada	help
15607744ccdbSTom Lendacky	  Say yes to have system memory encrypted by default if running on
15617744ccdbSTom Lendacky	  an AMD processor that supports Secure Memory Encryption (SME).
15627744ccdbSTom Lendacky
15637744ccdbSTom Lendacky	  If set to Y, then the encryption of system memory can be
15647744ccdbSTom Lendacky	  deactivated with the mem_encrypt=off command line option.
15657744ccdbSTom Lendacky
15667744ccdbSTom Lendacky	  If set to N, then the encryption of system memory can be
15677744ccdbSTom Lendacky	  activated with the mem_encrypt=on command line option.
15687744ccdbSTom Lendacky
1569506f1d07SSam Ravnborg# Common NUMA Features
1570506f1d07SSam Ravnborgconfig NUMA
1571e133f6eaSRandy Dunlap	bool "NUMA Memory Allocation and Scheduler Support"
1572506f1d07SSam Ravnborg	depends on SMP
1573b5660ba7SH. Peter Anvin	depends on X86_64 || (X86_32 && HIGHMEM64G && X86_BIGSMP)
1574b5660ba7SH. Peter Anvin	default y if X86_BIGSMP
15757ecd19cfSKefeng Wang	select USE_PERCPU_NUMA_NODE_ID
1576a7f7f624SMasahiro Yamada	help
1577e133f6eaSRandy Dunlap	  Enable NUMA (Non-Uniform Memory Access) support.
1578fd51b2d7SKOSAKI Motohiro
1579506f1d07SSam Ravnborg	  The kernel will try to allocate memory used by a CPU on the
1580506f1d07SSam Ravnborg	  local memory controller of the CPU and add some more
1581506f1d07SSam Ravnborg	  NUMA awareness to the kernel.
1582506f1d07SSam Ravnborg
1583c280ea5eSIngo Molnar	  For 64-bit this is recommended if the system is Intel Core i7
1584fd51b2d7SKOSAKI Motohiro	  (or later), AMD Opteron, or EM64T NUMA.
1585fd51b2d7SKOSAKI Motohiro
1586b5660ba7SH. Peter Anvin	  For 32-bit this is only needed if you boot a 32-bit
15877cf6c945SDavid Rientjes	  kernel on a 64-bit NUMA platform.
1588fd51b2d7SKOSAKI Motohiro
1589fd51b2d7SKOSAKI Motohiro	  Otherwise, you should say N.
1590506f1d07SSam Ravnborg
1591eec1d4faSHans Rosenfeldconfig AMD_NUMA
15923c2362e6SHarvey Harrison	def_bool y
15933c2362e6SHarvey Harrison	prompt "Old style AMD Opteron NUMA detection"
15945da0ef9aSTejun Heo	depends on X86_64 && NUMA && PCI
1595a7f7f624SMasahiro Yamada	help
1596eec1d4faSHans Rosenfeld	  Enable AMD NUMA node topology detection.  You should say Y here if
1597eec1d4faSHans Rosenfeld	  you have a multi processor AMD system. This uses an old method to
1598eec1d4faSHans Rosenfeld	  read the NUMA configuration directly from the builtin Northbridge
1599eec1d4faSHans Rosenfeld	  of Opteron. It is recommended to use X86_64_ACPI_NUMA instead,
1600eec1d4faSHans Rosenfeld	  which also takes priority if both are compiled in.
1601506f1d07SSam Ravnborg
1602506f1d07SSam Ravnborgconfig X86_64_ACPI_NUMA
16033c2362e6SHarvey Harrison	def_bool y
16043c2362e6SHarvey Harrison	prompt "ACPI NUMA detection"
1605506f1d07SSam Ravnborg	depends on X86_64 && NUMA && ACPI && PCI
1606506f1d07SSam Ravnborg	select ACPI_NUMA
1607a7f7f624SMasahiro Yamada	help
1608506f1d07SSam Ravnborg	  Enable ACPI SRAT based node topology detection.
1609506f1d07SSam Ravnborg
1610506f1d07SSam Ravnborgconfig NUMA_EMU
1611506f1d07SSam Ravnborg	bool "NUMA emulation"
16121b7e03efSTejun Heo	depends on NUMA
1613a7f7f624SMasahiro Yamada	help
1614506f1d07SSam Ravnborg	  Enable NUMA emulation. A flat machine will be split
1615506f1d07SSam Ravnborg	  into virtual nodes when booted with "numa=fake=N", where N is the
1616506f1d07SSam Ravnborg	  number of nodes. This is only useful for debugging.
1617506f1d07SSam Ravnborg
1618506f1d07SSam Ravnborgconfig NODES_SHIFT
1619d25e26b6SLinus Torvalds	int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP
162051591e31SDavid Rientjes	range 1 10
162151591e31SDavid Rientjes	default "10" if MAXSMP
1622506f1d07SSam Ravnborg	default "6" if X86_64
1623506f1d07SSam Ravnborg	default "3"
1624a9ee6cf5SMike Rapoport	depends on NUMA
1625a7f7f624SMasahiro Yamada	help
16261184dc2fSMike Travis	  Specify the maximum number of NUMA Nodes available on the target
1627692105b8SMatt LaPlante	  system.  Increases memory reserved to accommodate various tables.
1628506f1d07SSam Ravnborg
1629506f1d07SSam Ravnborgconfig ARCH_FLATMEM_ENABLE
1630506f1d07SSam Ravnborg	def_bool y
16313b16651fSTejun Heo	depends on X86_32 && !NUMA
1632506f1d07SSam Ravnborg
1633506f1d07SSam Ravnborgconfig ARCH_SPARSEMEM_ENABLE
1634506f1d07SSam Ravnborg	def_bool y
16356ea30386SKees Cook	depends on X86_64 || NUMA || X86_32 || X86_32_NON_STANDARD
1636506f1d07SSam Ravnborg	select SPARSEMEM_STATIC if X86_32
1637506f1d07SSam Ravnborg	select SPARSEMEM_VMEMMAP_ENABLE if X86_64
1638506f1d07SSam Ravnborg
16393b16651fSTejun Heoconfig ARCH_SPARSEMEM_DEFAULT
16406ad57f7fSMike Rapoport	def_bool X86_64 || (NUMA && X86_32)
16413b16651fSTejun Heo
1642506f1d07SSam Ravnborgconfig ARCH_SELECT_MEMORY_MODEL
1643506f1d07SSam Ravnborg	def_bool y
16444eda2bc3SDavid Hildenbrand	depends on ARCH_SPARSEMEM_ENABLE && ARCH_FLATMEM_ENABLE
1645506f1d07SSam Ravnborg
1646506f1d07SSam Ravnborgconfig ARCH_MEMORY_PROBE
1647a0842b70SToshi Kani	bool "Enable sysfs memory/probe interface"
16485c11f00bSDavid Hildenbrand	depends on MEMORY_HOTPLUG
1649a0842b70SToshi Kani	help
1650a0842b70SToshi Kani	  This option enables a sysfs memory/probe interface for testing.
1651cb1aaebeSMauro Carvalho Chehab	  See Documentation/admin-guide/mm/memory-hotplug.rst for more information.
1652a0842b70SToshi Kani	  If you are unsure how to answer this question, answer N.
1653506f1d07SSam Ravnborg
16543b16651fSTejun Heoconfig ARCH_PROC_KCORE_TEXT
16553b16651fSTejun Heo	def_bool y
16563b16651fSTejun Heo	depends on X86_64 && PROC_KCORE
16573b16651fSTejun Heo
1658a29815a3SAvi Kivityconfig ILLEGAL_POINTER_VALUE
1659a29815a3SAvi Kivity	hex
1660a29815a3SAvi Kivity	default 0 if X86_32
1661a29815a3SAvi Kivity	default 0xdead000000000000 if X86_64
1662a29815a3SAvi Kivity
16637a67832cSDan Williamsconfig X86_PMEM_LEGACY_DEVICE
16647a67832cSDan Williams	bool
16657a67832cSDan Williams
1666ec776ef6SChristoph Hellwigconfig X86_PMEM_LEGACY
16677a67832cSDan Williams	tristate "Support non-standard NVDIMMs and ADR protected memory"
16689f53f9faSDan Williams	depends on PHYS_ADDR_T_64BIT
16699f53f9faSDan Williams	depends on BLK_DEV
16707a67832cSDan Williams	select X86_PMEM_LEGACY_DEVICE
16717b27a862SDan Williams	select NUMA_KEEP_MEMINFO if NUMA
16729f53f9faSDan Williams	select LIBNVDIMM
1673ec776ef6SChristoph Hellwig	help
1674ec776ef6SChristoph Hellwig	  Treat memory marked using the non-standard e820 type of 12 as used
1675ec776ef6SChristoph Hellwig	  by the Intel Sandy Bridge-EP reference BIOS as protected memory.
1676ec776ef6SChristoph Hellwig	  The kernel will offer these regions to the 'pmem' driver so
1677ec776ef6SChristoph Hellwig	  they can be used for persistent storage.
1678ec776ef6SChristoph Hellwig
1679ec776ef6SChristoph Hellwig	  Say Y if unsure.
1680ec776ef6SChristoph Hellwig
1681506f1d07SSam Ravnborgconfig HIGHPTE
1682506f1d07SSam Ravnborg	bool "Allocate 3rd-level pagetables from highmem"
16836fc108a0SJan Beulich	depends on HIGHMEM
1684a7f7f624SMasahiro Yamada	help
1685506f1d07SSam Ravnborg	  The VM uses one page table entry for each page of physical memory.
1686506f1d07SSam Ravnborg	  For systems with a lot of RAM, this can be wasteful of precious
1687506f1d07SSam Ravnborg	  low memory.  Setting this option will put user-space page table
1688506f1d07SSam Ravnborg	  entries in high memory.
1689506f1d07SSam Ravnborg
16909f077871SJeremy Fitzhardingeconfig X86_CHECK_BIOS_CORRUPTION
16919f077871SJeremy Fitzhardinge	bool "Check for low memory corruption"
1692a7f7f624SMasahiro Yamada	help
16939f077871SJeremy Fitzhardinge	  Periodically check for memory corruption in low memory, which
16949f077871SJeremy Fitzhardinge	  is suspected to be caused by BIOS.  Even when enabled in the
16959f077871SJeremy Fitzhardinge	  configuration, it is disabled at runtime.  Enable it by
16969f077871SJeremy Fitzhardinge	  setting "memory_corruption_check=1" on the kernel command
16979f077871SJeremy Fitzhardinge	  line.  By default it scans the low 64k of memory every 60
16989f077871SJeremy Fitzhardinge	  seconds; see the memory_corruption_check_size and
16999f077871SJeremy Fitzhardinge	  memory_corruption_check_period parameters in
17008c27ceffSMauro Carvalho Chehab	  Documentation/admin-guide/kernel-parameters.rst to adjust this.
17019f077871SJeremy Fitzhardinge
17029f077871SJeremy Fitzhardinge	  When enabled with the default parameters, this option has
17039f077871SJeremy Fitzhardinge	  almost no overhead, as it reserves a relatively small amount
17049f077871SJeremy Fitzhardinge	  of memory and scans it infrequently.  It both detects corruption
17059f077871SJeremy Fitzhardinge	  and prevents it from affecting the running system.
17069f077871SJeremy Fitzhardinge
17079f077871SJeremy Fitzhardinge	  It is, however, intended as a diagnostic tool; if repeatable
17089f077871SJeremy Fitzhardinge	  BIOS-originated corruption always affects the same memory,
17099f077871SJeremy Fitzhardinge	  you can use memmap= to prevent the kernel from using that
17109f077871SJeremy Fitzhardinge	  memory.
17119f077871SJeremy Fitzhardinge
1712c885df50SJeremy Fitzhardingeconfig X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK
1713c885df50SJeremy Fitzhardinge	bool "Set the default setting of memory_corruption_check"
1714c885df50SJeremy Fitzhardinge	depends on X86_CHECK_BIOS_CORRUPTION
1715c885df50SJeremy Fitzhardinge	default y
1716a7f7f624SMasahiro Yamada	help
1717c885df50SJeremy Fitzhardinge	  Set whether the default state of memory_corruption_check is
1718c885df50SJeremy Fitzhardinge	  on or off.
1719c885df50SJeremy Fitzhardinge
1720506f1d07SSam Ravnborgconfig MATH_EMULATION
1721506f1d07SSam Ravnborg	bool
1722a5b9e5a2SAndy Lutomirski	depends on MODIFY_LDT_SYSCALL
172387d6021bSArnd Bergmann	prompt "Math emulation" if X86_32 && (M486SX || MELAN)
1724a7f7f624SMasahiro Yamada	help
1725506f1d07SSam Ravnborg	  Linux can emulate a math coprocessor (used for floating point
1726506f1d07SSam Ravnborg	  operations) if you don't have one. 486DX and Pentium processors have
1727506f1d07SSam Ravnborg	  a math coprocessor built in, 486SX and 386 do not, unless you added
1728506f1d07SSam Ravnborg	  a 487DX or 387, respectively. (The messages during boot time can
1729506f1d07SSam Ravnborg	  give you some hints here ["man dmesg"].) Everyone needs either a
1730506f1d07SSam Ravnborg	  coprocessor or this emulation.
1731506f1d07SSam Ravnborg
1732506f1d07SSam Ravnborg	  If you don't have a math coprocessor, you need to say Y here; if you
1733506f1d07SSam Ravnborg	  say Y here even though you have a coprocessor, the coprocessor will
1734506f1d07SSam Ravnborg	  be used nevertheless. (This behavior can be changed with the kernel
1735506f1d07SSam Ravnborg	  command line option "no387", which comes handy if your coprocessor
1736506f1d07SSam Ravnborg	  is broken. Try "man bootparam" or see the documentation of your boot
1737506f1d07SSam Ravnborg	  loader (lilo or loadlin) about how to pass options to the kernel at
1738506f1d07SSam Ravnborg	  boot time.) This means that it is a good idea to say Y here if you
1739506f1d07SSam Ravnborg	  intend to use this kernel on different machines.
1740506f1d07SSam Ravnborg
1741506f1d07SSam Ravnborg	  More information about the internals of the Linux math coprocessor
1742506f1d07SSam Ravnborg	  emulation can be found in <file:arch/x86/math-emu/README>.
1743506f1d07SSam Ravnborg
1744506f1d07SSam Ravnborg	  If you are not sure, say Y; apart from resulting in a 66 KB bigger
1745506f1d07SSam Ravnborg	  kernel, it won't hurt.
1746506f1d07SSam Ravnborg
1747506f1d07SSam Ravnborgconfig MTRR
17486fc108a0SJan Beulich	def_bool y
17496a108a14SDavid Rientjes	prompt "MTRR (Memory Type Range Register) support" if EXPERT
1750a7f7f624SMasahiro Yamada	help
1751506f1d07SSam Ravnborg	  On Intel P6 family processors (Pentium Pro, Pentium II and later)
1752506f1d07SSam Ravnborg	  the Memory Type Range Registers (MTRRs) may be used to control
1753506f1d07SSam Ravnborg	  processor access to memory ranges. This is most useful if you have
1754506f1d07SSam Ravnborg	  a video (VGA) card on a PCI or AGP bus. Enabling write-combining
1755506f1d07SSam Ravnborg	  allows bus write transfers to be combined into a larger transfer
1756506f1d07SSam Ravnborg	  before bursting over the PCI/AGP bus. This can increase performance
1757506f1d07SSam Ravnborg	  of image write operations 2.5 times or more. Saying Y here creates a
1758506f1d07SSam Ravnborg	  /proc/mtrr file which may be used to manipulate your processor's
1759506f1d07SSam Ravnborg	  MTRRs. Typically the X server should use this.
1760506f1d07SSam Ravnborg
1761506f1d07SSam Ravnborg	  This code has a reasonably generic interface so that similar
1762506f1d07SSam Ravnborg	  control registers on other processors can be easily supported
1763506f1d07SSam Ravnborg	  as well:
1764506f1d07SSam Ravnborg
1765506f1d07SSam Ravnborg	  The Cyrix 6x86, 6x86MX and M II processors have Address Range
1766506f1d07SSam Ravnborg	  Registers (ARRs) which provide a similar functionality to MTRRs. For
1767506f1d07SSam Ravnborg	  these, the ARRs are used to emulate the MTRRs.
1768506f1d07SSam Ravnborg	  The AMD K6-2 (stepping 8 and above) and K6-3 processors have two
1769506f1d07SSam Ravnborg	  MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing
1770506f1d07SSam Ravnborg	  write-combining. All of these processors are supported by this code
1771506f1d07SSam Ravnborg	  and it makes sense to say Y here if you have one of them.
1772506f1d07SSam Ravnborg
1773506f1d07SSam Ravnborg	  Saying Y here also fixes a problem with buggy SMP BIOSes which only
1774506f1d07SSam Ravnborg	  set the MTRRs for the boot CPU and not for the secondary CPUs. This
1775506f1d07SSam Ravnborg	  can lead to all sorts of problems, so it's good to say Y here.
1776506f1d07SSam Ravnborg
1777506f1d07SSam Ravnborg	  You can safely say Y even if your machine doesn't have MTRRs, you'll
1778506f1d07SSam Ravnborg	  just add about 9 KB to your kernel.
1779506f1d07SSam Ravnborg
1780cb1aaebeSMauro Carvalho Chehab	  See <file:Documentation/x86/mtrr.rst> for more information.
1781506f1d07SSam Ravnborg
178295ffa243SYinghai Luconfig MTRR_SANITIZER
17832ffb3501SYinghai Lu	def_bool y
178495ffa243SYinghai Lu	prompt "MTRR cleanup support"
178595ffa243SYinghai Lu	depends on MTRR
1786a7f7f624SMasahiro Yamada	help
1787aba3728cSThomas Gleixner	  Convert MTRR layout from continuous to discrete, so X drivers can
1788aba3728cSThomas Gleixner	  add writeback entries.
178995ffa243SYinghai Lu
1790aba3728cSThomas Gleixner	  Can be disabled with disable_mtrr_cleanup on the kernel command line.
1791692105b8SMatt LaPlante	  The largest mtrr entry size for a continuous block can be set with
1792aba3728cSThomas Gleixner	  mtrr_chunk_size.
179395ffa243SYinghai Lu
17942ffb3501SYinghai Lu	  If unsure, say Y.
179595ffa243SYinghai Lu
179695ffa243SYinghai Luconfig MTRR_SANITIZER_ENABLE_DEFAULT
1797f5098d62SYinghai Lu	int "MTRR cleanup enable value (0-1)"
1798f5098d62SYinghai Lu	range 0 1
1799f5098d62SYinghai Lu	default "0"
180095ffa243SYinghai Lu	depends on MTRR_SANITIZER
1801a7f7f624SMasahiro Yamada	help
1802f5098d62SYinghai Lu	  Enable mtrr cleanup default value
180395ffa243SYinghai Lu
180412031a62SYinghai Luconfig MTRR_SANITIZER_SPARE_REG_NR_DEFAULT
180512031a62SYinghai Lu	int "MTRR cleanup spare reg num (0-7)"
180612031a62SYinghai Lu	range 0 7
180712031a62SYinghai Lu	default "1"
180812031a62SYinghai Lu	depends on MTRR_SANITIZER
1809a7f7f624SMasahiro Yamada	help
181012031a62SYinghai Lu	  mtrr cleanup spare entries default, it can be changed via
1811aba3728cSThomas Gleixner	  mtrr_spare_reg_nr=N on the kernel command line.
181212031a62SYinghai Lu
18132e5d9c85Svenkatesh.pallipadi@intel.comconfig X86_PAT
18146fc108a0SJan Beulich	def_bool y
18156a108a14SDavid Rientjes	prompt "x86 PAT support" if EXPERT
18162a8a2719SIngo Molnar	depends on MTRR
1817a7f7f624SMasahiro Yamada	help
18182e5d9c85Svenkatesh.pallipadi@intel.com	  Use PAT attributes to setup page level cache control.
1819042b78e4SVenki Pallipadi
18202e5d9c85Svenkatesh.pallipadi@intel.com	  PATs are the modern equivalents of MTRRs and are much more
18212e5d9c85Svenkatesh.pallipadi@intel.com	  flexible than MTRRs.
18222e5d9c85Svenkatesh.pallipadi@intel.com
18232e5d9c85Svenkatesh.pallipadi@intel.com	  Say N here if you see bootup problems (boot crash, boot hang,
1824042b78e4SVenki Pallipadi	  spontaneous reboots) or a non-working video driver.
18252e5d9c85Svenkatesh.pallipadi@intel.com
18262e5d9c85Svenkatesh.pallipadi@intel.com	  If unsure, say Y.
18272e5d9c85Svenkatesh.pallipadi@intel.com
182846cf98cdSVenkatesh Pallipadiconfig ARCH_USES_PG_UNCACHED
182946cf98cdSVenkatesh Pallipadi	def_bool y
183046cf98cdSVenkatesh Pallipadi	depends on X86_PAT
183146cf98cdSVenkatesh Pallipadi
1832b971880fSBabu Mogerconfig X86_UMIP
1833796ebc81SRicardo Neri	def_bool y
1834b971880fSBabu Moger	prompt "User Mode Instruction Prevention" if EXPERT
1835a7f7f624SMasahiro Yamada	help
1836b971880fSBabu Moger	  User Mode Instruction Prevention (UMIP) is a security feature in
1837b971880fSBabu Moger	  some x86 processors. If enabled, a general protection fault is
1838b971880fSBabu Moger	  issued if the SGDT, SLDT, SIDT, SMSW or STR instructions are
1839b971880fSBabu Moger	  executed in user mode. These instructions unnecessarily expose
1840b971880fSBabu Moger	  information about the hardware state.
1841796ebc81SRicardo Neri
1842796ebc81SRicardo Neri	  The vast majority of applications do not use these instructions.
1843796ebc81SRicardo Neri	  For the very few that do, software emulation is provided in
1844796ebc81SRicardo Neri	  specific cases in protected and virtual-8086 modes. Emulated
1845796ebc81SRicardo Neri	  results are dummy.
1846aa35f896SRicardo Neri
1847156ff4a5SPeter Zijlstraconfig CC_HAS_IBT
1848156ff4a5SPeter Zijlstra	# GCC >= 9 and binutils >= 2.29
1849156ff4a5SPeter Zijlstra	# Retpoline check to work around https://gcc.gnu.org/bugzilla/show_bug.cgi?id=93654
1850156ff4a5SPeter Zijlstra	# Clang/LLVM >= 14
1851262448f3SNathan Chancellor	# https://github.com/llvm/llvm-project/commit/e0b89df2e0f0130881bf6c39bf31d7f6aac00e0f
1852262448f3SNathan Chancellor	# https://github.com/llvm/llvm-project/commit/dfcf69770bc522b9e411c66454934a37c1f35332
1853156ff4a5SPeter Zijlstra	def_bool ((CC_IS_GCC && $(cc-option, -fcf-protection=branch -mindirect-branch-register)) || \
1854262448f3SNathan Chancellor		  (CC_IS_CLANG && CLANG_VERSION >= 140000)) && \
1855156ff4a5SPeter Zijlstra		  $(as-instr,endbr64)
1856156ff4a5SPeter Zijlstra
1857156ff4a5SPeter Zijlstraconfig X86_KERNEL_IBT
1858156ff4a5SPeter Zijlstra	prompt "Indirect Branch Tracking"
1859156ff4a5SPeter Zijlstra	bool
186003f16cd0SJosh Poimboeuf	depends on X86_64 && CC_HAS_IBT && HAVE_OBJTOOL
1861f6a2c2b2SNathan Chancellor	# https://github.com/llvm/llvm-project/commit/9d7001eba9c4cb311e03cd8cdc231f9e579f2d0f
1862f6a2c2b2SNathan Chancellor	depends on !LD_IS_LLD || LLD_VERSION >= 140000
186303f16cd0SJosh Poimboeuf	select OBJTOOL
1864156ff4a5SPeter Zijlstra	help
1865156ff4a5SPeter Zijlstra	  Build the kernel with support for Indirect Branch Tracking, a
1866156ff4a5SPeter Zijlstra	  hardware support course-grain forward-edge Control Flow Integrity
1867156ff4a5SPeter Zijlstra	  protection. It enforces that all indirect calls must land on
1868156ff4a5SPeter Zijlstra	  an ENDBR instruction, as such, the compiler will instrument the
1869156ff4a5SPeter Zijlstra	  code with them to make this happen.
1870156ff4a5SPeter Zijlstra
1871ed53a0d9SPeter Zijlstra	  In addition to building the kernel with IBT, seal all functions that
18724cdfc11bSNur Hussein	  are not indirect call targets, avoiding them ever becoming one.
1873ed53a0d9SPeter Zijlstra
1874ed53a0d9SPeter Zijlstra	  This requires LTO like objtool runs and will slow down the build. It
1875ed53a0d9SPeter Zijlstra	  does significantly reduce the number of ENDBR instructions in the
1876ed53a0d9SPeter Zijlstra	  kernel image.
1877ed53a0d9SPeter Zijlstra
187835e97790SDave Hansenconfig X86_INTEL_MEMORY_PROTECTION_KEYS
187938f3e775SBabu Moger	prompt "Memory Protection Keys"
188035e97790SDave Hansen	def_bool y
1881284244a9SDave Hansen	# Note: only available in 64-bit mode
188238f3e775SBabu Moger	depends on X86_64 && (CPU_SUP_INTEL || CPU_SUP_AMD)
188352c8e601SIngo Molnar	select ARCH_USES_HIGH_VMA_FLAGS
188452c8e601SIngo Molnar	select ARCH_HAS_PKEYS
1885a7f7f624SMasahiro Yamada	help
1886284244a9SDave Hansen	  Memory Protection Keys provides a mechanism for enforcing
1887284244a9SDave Hansen	  page-based protections, but without requiring modification of the
1888284244a9SDave Hansen	  page tables when an application changes protection domains.
1889284244a9SDave Hansen
18901eecbcdcSMauro Carvalho Chehab	  For details, see Documentation/core-api/protection-keys.rst
1891284244a9SDave Hansen
1892284244a9SDave Hansen	  If unsure, say y.
189335e97790SDave Hansen
1894db616173SMichal Hockochoice
1895db616173SMichal Hocko	prompt "TSX enable mode"
1896db616173SMichal Hocko	depends on CPU_SUP_INTEL
1897db616173SMichal Hocko	default X86_INTEL_TSX_MODE_OFF
1898db616173SMichal Hocko	help
1899db616173SMichal Hocko	  Intel's TSX (Transactional Synchronization Extensions) feature
1900db616173SMichal Hocko	  allows to optimize locking protocols through lock elision which
1901db616173SMichal Hocko	  can lead to a noticeable performance boost.
1902db616173SMichal Hocko
1903db616173SMichal Hocko	  On the other hand it has been shown that TSX can be exploited
1904db616173SMichal Hocko	  to form side channel attacks (e.g. TAA) and chances are there
1905db616173SMichal Hocko	  will be more of those attacks discovered in the future.
1906db616173SMichal Hocko
1907db616173SMichal Hocko	  Therefore TSX is not enabled by default (aka tsx=off). An admin
1908db616173SMichal Hocko	  might override this decision by tsx=on the command line parameter.
1909db616173SMichal Hocko	  Even with TSX enabled, the kernel will attempt to enable the best
1910db616173SMichal Hocko	  possible TAA mitigation setting depending on the microcode available
1911db616173SMichal Hocko	  for the particular machine.
1912db616173SMichal Hocko
1913db616173SMichal Hocko	  This option allows to set the default tsx mode between tsx=on, =off
1914db616173SMichal Hocko	  and =auto. See Documentation/admin-guide/kernel-parameters.txt for more
1915db616173SMichal Hocko	  details.
1916db616173SMichal Hocko
1917db616173SMichal Hocko	  Say off if not sure, auto if TSX is in use but it should be used on safe
1918db616173SMichal Hocko	  platforms or on if TSX is in use and the security aspect of tsx is not
1919db616173SMichal Hocko	  relevant.
1920db616173SMichal Hocko
1921db616173SMichal Hockoconfig X86_INTEL_TSX_MODE_OFF
1922db616173SMichal Hocko	bool "off"
1923db616173SMichal Hocko	help
1924db616173SMichal Hocko	  TSX is disabled if possible - equals to tsx=off command line parameter.
1925db616173SMichal Hocko
1926db616173SMichal Hockoconfig X86_INTEL_TSX_MODE_ON
1927db616173SMichal Hocko	bool "on"
1928db616173SMichal Hocko	help
1929db616173SMichal Hocko	  TSX is always enabled on TSX capable HW - equals the tsx=on command
1930db616173SMichal Hocko	  line parameter.
1931db616173SMichal Hocko
1932db616173SMichal Hockoconfig X86_INTEL_TSX_MODE_AUTO
1933db616173SMichal Hocko	bool "auto"
1934db616173SMichal Hocko	help
1935db616173SMichal Hocko	  TSX is enabled on TSX capable HW that is believed to be safe against
1936db616173SMichal Hocko	  side channel attacks- equals the tsx=auto command line parameter.
1937db616173SMichal Hockoendchoice
1938db616173SMichal Hocko
1939e7e05452SSean Christophersonconfig X86_SGX
1940e7e05452SSean Christopherson	bool "Software Guard eXtensions (SGX)"
1941b8d1d163SDaniel Sneddon	depends on X86_64 && CPU_SUP_INTEL && X86_X2APIC
1942e7e05452SSean Christopherson	depends on CRYPTO=y
1943e7e05452SSean Christopherson	depends on CRYPTO_SHA256=y
1944e7e05452SSean Christopherson	select SRCU
1945e7e05452SSean Christopherson	select MMU_NOTIFIER
1946901ddbb9SJarkko Sakkinen	select NUMA_KEEP_MEMINFO if NUMA
194740e0e784STony Luck	select XARRAY_MULTI
1948e7e05452SSean Christopherson	help
1949e7e05452SSean Christopherson	  Intel(R) Software Guard eXtensions (SGX) is a set of CPU instructions
1950e7e05452SSean Christopherson	  that can be used by applications to set aside private regions of code
1951e7e05452SSean Christopherson	  and data, referred to as enclaves. An enclave's private memory can
1952e7e05452SSean Christopherson	  only be accessed by code running within the enclave. Accesses from
1953e7e05452SSean Christopherson	  outside the enclave, including other enclaves, are disallowed by
1954e7e05452SSean Christopherson	  hardware.
1955e7e05452SSean Christopherson
1956e7e05452SSean Christopherson	  If unsure, say N.
1957e7e05452SSean Christopherson
1958506f1d07SSam Ravnborgconfig EFI
19599ba16087SJan Beulich	bool "EFI runtime service support"
19605b83683fSHuang, Ying	depends on ACPI
1961f6ce5002SSergey Vlasov	select UCS2_STRING
1962022ee6c5SArd Biesheuvel	select EFI_RUNTIME_WRAPPERS
19631ff2fc02STom Lendacky	select ARCH_USE_MEMREMAP_PROT
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
19788f24f8c2SArd Biesheuvel	depends on $(cc-option,-mabi=ms) || X86_32
19797b2a583aSMatt Fleming	select RELOCATABLE
1980a7f7f624SMasahiro Yamada	help
1981291f3632SMatt Fleming	  This kernel feature allows a bzImage to be loaded directly
1982291f3632SMatt Fleming	  by EFI firmware without the use of a bootloader.
1983291f3632SMatt Fleming
19844f4cfa6cSMauro Carvalho Chehab	  See Documentation/admin-guide/efi-stub.rst for more information.
19850c759662SMatt Fleming
19867d453eeeSMatt Flemingconfig EFI_MIXED
19877d453eeeSMatt Fleming	bool "EFI mixed-mode support"
19887d453eeeSMatt Fleming	depends on EFI_STUB && X86_64
1989a7f7f624SMasahiro Yamada	help
19907d453eeeSMatt Fleming	  Enabling this feature allows a 64-bit kernel to be booted
19917d453eeeSMatt Fleming	  on a 32-bit firmware, provided that your CPU supports 64-bit
19927d453eeeSMatt Fleming	  mode.
19937d453eeeSMatt Fleming
19947d453eeeSMatt Fleming	  Note that it is not possible to boot a mixed-mode enabled
19957d453eeeSMatt Fleming	  kernel via the EFI boot stub - a bootloader that supports
19967d453eeeSMatt Fleming	  the EFI handover protocol must be used.
19977d453eeeSMatt Fleming
19987d453eeeSMatt Fleming	  If unsure, say N.
19997d453eeeSMatt Fleming
20008636a1f9SMasahiro Yamadasource "kernel/Kconfig.hz"
2001506f1d07SSam Ravnborg
2002506f1d07SSam Ravnborgconfig KEXEC
2003506f1d07SSam Ravnborg	bool "kexec system call"
20042965faa5SDave Young	select KEXEC_CORE
2005a7f7f624SMasahiro Yamada	help
2006506f1d07SSam Ravnborg	  kexec is a system call that implements the ability to shutdown your
2007506f1d07SSam Ravnborg	  current kernel, and to start another kernel.  It is like a reboot
2008506f1d07SSam Ravnborg	  but it is independent of the system firmware.   And like a reboot
2009506f1d07SSam Ravnborg	  you can start any kernel with it, not just Linux.
2010506f1d07SSam Ravnborg
2011506f1d07SSam Ravnborg	  The name comes from the similarity to the exec system call.
2012506f1d07SSam Ravnborg
2013506f1d07SSam Ravnborg	  It is an ongoing process to be certain the hardware in a machine
2014506f1d07SSam Ravnborg	  is properly shutdown, so do not be surprised if this code does not
2015bf220695SGeert Uytterhoeven	  initially work for you.  As of this writing the exact hardware
2016bf220695SGeert Uytterhoeven	  interface is strongly in flux, so no good recommendation can be
2017bf220695SGeert Uytterhoeven	  made.
2018506f1d07SSam Ravnborg
201974ca317cSVivek Goyalconfig KEXEC_FILE
202074ca317cSVivek Goyal	bool "kexec file based system call"
20212965faa5SDave Young	select KEXEC_CORE
2022b69a2afdSJonathan McDowell	select HAVE_IMA_KEXEC if IMA
202374ca317cSVivek Goyal	depends on X86_64
202474ca317cSVivek Goyal	depends on CRYPTO=y
202574ca317cSVivek Goyal	depends on CRYPTO_SHA256=y
2026a7f7f624SMasahiro Yamada	help
202774ca317cSVivek Goyal	  This is new version of kexec system call. This system call is
202874ca317cSVivek Goyal	  file based and takes file descriptors as system call argument
202974ca317cSVivek Goyal	  for kernel and initramfs as opposed to list of segments as
203074ca317cSVivek Goyal	  accepted by previous system call.
203174ca317cSVivek Goyal
2032b799a09fSAKASHI Takahiroconfig ARCH_HAS_KEXEC_PURGATORY
2033b799a09fSAKASHI Takahiro	def_bool KEXEC_FILE
2034b799a09fSAKASHI Takahiro
203599d5cadfSJiri Bohacconfig KEXEC_SIG
20368e7d8381SVivek Goyal	bool "Verify kernel signature during kexec_file_load() syscall"
203774ca317cSVivek Goyal	depends on KEXEC_FILE
2038a7f7f624SMasahiro Yamada	help
203999d5cadfSJiri Bohac
204099d5cadfSJiri Bohac	  This option makes the kexec_file_load() syscall check for a valid
204199d5cadfSJiri Bohac	  signature of the kernel image.  The image can still be loaded without
204299d5cadfSJiri Bohac	  a valid signature unless you also enable KEXEC_SIG_FORCE, though if
204399d5cadfSJiri Bohac	  there's a signature that we can check, then it must be valid.
204499d5cadfSJiri Bohac
204599d5cadfSJiri Bohac	  In addition to this option, you need to enable signature
204699d5cadfSJiri Bohac	  verification for the corresponding kernel image type being
204799d5cadfSJiri Bohac	  loaded in order for this to work.
204899d5cadfSJiri Bohac
204999d5cadfSJiri Bohacconfig KEXEC_SIG_FORCE
205099d5cadfSJiri Bohac	bool "Require a valid signature in kexec_file_load() syscall"
205199d5cadfSJiri Bohac	depends on KEXEC_SIG
2052a7f7f624SMasahiro Yamada	help
20538e7d8381SVivek Goyal	  This option makes kernel signature verification mandatory for
2054d8eb8940SBorislav Petkov	  the kexec_file_load() syscall.
20558e7d8381SVivek Goyal
20568e7d8381SVivek Goyalconfig KEXEC_BZIMAGE_VERIFY_SIG
20578e7d8381SVivek Goyal	bool "Enable bzImage signature verification support"
205899d5cadfSJiri Bohac	depends on KEXEC_SIG
20598e7d8381SVivek Goyal	depends on SIGNED_PE_FILE_VERIFICATION
20608e7d8381SVivek Goyal	select SYSTEM_TRUSTED_KEYRING
2061a7f7f624SMasahiro Yamada	help
20628e7d8381SVivek Goyal	  Enable bzImage signature verification support.
20638e7d8381SVivek Goyal
2064506f1d07SSam Ravnborgconfig CRASH_DUMP
206504b69447SPavel Machek	bool "kernel crash dumps"
2066506f1d07SSam Ravnborg	depends on X86_64 || (X86_32 && HIGHMEM)
2067a7f7f624SMasahiro Yamada	help
2068506f1d07SSam Ravnborg	  Generate crash dump after being started by kexec.
2069506f1d07SSam Ravnborg	  This should be normally only set in special crash dump kernels
2070506f1d07SSam Ravnborg	  which are loaded in the main kernel with kexec-tools into
2071506f1d07SSam Ravnborg	  a specially reserved region and then later executed after
2072506f1d07SSam Ravnborg	  a crash by kdump/kexec. The crash dump kernel must be compiled
2073506f1d07SSam Ravnborg	  to a memory address not used by the main kernel or BIOS using
2074506f1d07SSam Ravnborg	  PHYSICAL_START, or it must be built as a relocatable image
2075506f1d07SSam Ravnborg	  (CONFIG_RELOCATABLE=y).
2076330d4810SMauro Carvalho Chehab	  For more details see Documentation/admin-guide/kdump/kdump.rst
2077506f1d07SSam Ravnborg
20783ab83521SHuang Yingconfig KEXEC_JUMP
20796ea30386SKees Cook	bool "kexec jump"
2080fee7b0d8SHuang Ying	depends on KEXEC && HIBERNATION
2081a7f7f624SMasahiro Yamada	help
208289081d17SHuang Ying	  Jump between original kernel and kexeced kernel and invoke
208389081d17SHuang Ying	  code in physical address mode via KEXEC
20843ab83521SHuang Ying
2085506f1d07SSam Ravnborgconfig PHYSICAL_START
20866a108a14SDavid Rientjes	hex "Physical address where the kernel is loaded" if (EXPERT || CRASH_DUMP)
2087ceefccc9SH. Peter Anvin	default "0x1000000"
2088a7f7f624SMasahiro Yamada	help
2089506f1d07SSam Ravnborg	  This gives the physical address where the kernel is loaded.
2090506f1d07SSam Ravnborg
2091506f1d07SSam Ravnborg	  If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then
2092506f1d07SSam Ravnborg	  bzImage will decompress itself to above physical address and
2093506f1d07SSam Ravnborg	  run from there. Otherwise, bzImage will run from the address where
2094506f1d07SSam Ravnborg	  it has been loaded by the boot loader and will ignore above physical
2095506f1d07SSam Ravnborg	  address.
2096506f1d07SSam Ravnborg
2097506f1d07SSam Ravnborg	  In normal kdump cases one does not have to set/change this option
2098506f1d07SSam Ravnborg	  as now bzImage can be compiled as a completely relocatable image
2099506f1d07SSam Ravnborg	  (CONFIG_RELOCATABLE=y) and be used to load and run from a different
2100506f1d07SSam Ravnborg	  address. This option is mainly useful for the folks who don't want
2101506f1d07SSam Ravnborg	  to use a bzImage for capturing the crash dump and want to use a
2102506f1d07SSam Ravnborg	  vmlinux instead. vmlinux is not relocatable hence a kernel needs
2103506f1d07SSam Ravnborg	  to be specifically compiled to run from a specific memory area
2104506f1d07SSam Ravnborg	  (normally a reserved region) and this option comes handy.
2105506f1d07SSam Ravnborg
2106ceefccc9SH. Peter Anvin	  So if you are using bzImage for capturing the crash dump,
2107ceefccc9SH. Peter Anvin	  leave the value here unchanged to 0x1000000 and set
2108ceefccc9SH. Peter Anvin	  CONFIG_RELOCATABLE=y.  Otherwise if you plan to use vmlinux
2109ceefccc9SH. Peter Anvin	  for capturing the crash dump change this value to start of
2110ceefccc9SH. Peter Anvin	  the reserved region.  In other words, it can be set based on
2111ceefccc9SH. Peter Anvin	  the "X" value as specified in the "crashkernel=YM@XM"
2112ceefccc9SH. Peter Anvin	  command line boot parameter passed to the panic-ed
2113330d4810SMauro Carvalho Chehab	  kernel. Please take a look at Documentation/admin-guide/kdump/kdump.rst
2114ceefccc9SH. Peter Anvin	  for more details about crash dumps.
2115506f1d07SSam Ravnborg
2116506f1d07SSam Ravnborg	  Usage of bzImage for capturing the crash dump is recommended as
2117506f1d07SSam Ravnborg	  one does not have to build two kernels. Same kernel can be used
2118506f1d07SSam Ravnborg	  as production kernel and capture kernel. Above option should have
2119506f1d07SSam Ravnborg	  gone away after relocatable bzImage support is introduced. But it
2120506f1d07SSam Ravnborg	  is present because there are users out there who continue to use
2121506f1d07SSam Ravnborg	  vmlinux for dump capture. This option should go away down the
2122506f1d07SSam Ravnborg	  line.
2123506f1d07SSam Ravnborg
2124506f1d07SSam Ravnborg	  Don't change this unless you know what you are doing.
2125506f1d07SSam Ravnborg
2126506f1d07SSam Ravnborgconfig RELOCATABLE
212726717808SH. Peter Anvin	bool "Build a relocatable kernel"
212826717808SH. Peter Anvin	default y
2129a7f7f624SMasahiro Yamada	help
2130506f1d07SSam Ravnborg	  This builds a kernel image that retains relocation information
2131506f1d07SSam Ravnborg	  so it can be loaded someplace besides the default 1MB.
2132506f1d07SSam Ravnborg	  The relocations tend to make the kernel binary about 10% larger,
2133506f1d07SSam Ravnborg	  but are discarded at runtime.
2134506f1d07SSam Ravnborg
2135506f1d07SSam Ravnborg	  One use is for the kexec on panic case where the recovery kernel
2136506f1d07SSam Ravnborg	  must live at a different physical address than the primary
2137506f1d07SSam Ravnborg	  kernel.
2138506f1d07SSam Ravnborg
2139506f1d07SSam Ravnborg	  Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address
2140506f1d07SSam Ravnborg	  it has been loaded at and the compile time physical address
21418ab3820fSKees Cook	  (CONFIG_PHYSICAL_START) is used as the minimum location.
2142506f1d07SSam Ravnborg
21438ab3820fSKees Cookconfig RANDOMIZE_BASE
2144e8581e3dSBaoquan He	bool "Randomize the address of the kernel image (KASLR)"
21458ab3820fSKees Cook	depends on RELOCATABLE
21466807c846SIngo Molnar	default y
2147a7f7f624SMasahiro Yamada	help
2148e8581e3dSBaoquan He	  In support of Kernel Address Space Layout Randomization (KASLR),
2149e8581e3dSBaoquan He	  this randomizes the physical address at which the kernel image
2150e8581e3dSBaoquan He	  is decompressed and the virtual address where the kernel
2151e8581e3dSBaoquan He	  image is mapped, as a security feature that deters exploit
2152e8581e3dSBaoquan He	  attempts relying on knowledge of the location of kernel
2153e8581e3dSBaoquan He	  code internals.
2154e8581e3dSBaoquan He
2155ed9f007eSKees Cook	  On 64-bit, the kernel physical and virtual addresses are
2156ed9f007eSKees Cook	  randomized separately. The physical address will be anywhere
2157ed9f007eSKees Cook	  between 16MB and the top of physical memory (up to 64TB). The
2158ed9f007eSKees Cook	  virtual address will be randomized from 16MB up to 1GB (9 bits
2159ed9f007eSKees Cook	  of entropy). Note that this also reduces the memory space
2160ed9f007eSKees Cook	  available to kernel modules from 1.5GB to 1GB.
2161ed9f007eSKees Cook
2162ed9f007eSKees Cook	  On 32-bit, the kernel physical and virtual addresses are
2163ed9f007eSKees Cook	  randomized together. They will be randomized from 16MB up to
2164ed9f007eSKees Cook	  512MB (8 bits of entropy).
21658ab3820fSKees Cook
2166a653f356SKees Cook	  Entropy is generated using the RDRAND instruction if it is
2167e8581e3dSBaoquan He	  supported. If RDTSC is supported, its value is mixed into
2168e8581e3dSBaoquan He	  the entropy pool as well. If neither RDRAND nor RDTSC are
2169ed9f007eSKees Cook	  supported, then entropy is read from the i8254 timer. The
2170ed9f007eSKees Cook	  usable entropy is limited by the kernel being built using
2171ed9f007eSKees Cook	  2GB addressing, and that PHYSICAL_ALIGN must be at a
2172ed9f007eSKees Cook	  minimum of 2MB. As a result, only 10 bits of entropy are
2173ed9f007eSKees Cook	  theoretically possible, but the implementations are further
2174ed9f007eSKees Cook	  limited due to memory layouts.
2175e8581e3dSBaoquan He
21766807c846SIngo Molnar	  If unsure, say Y.
2177da2b6fb9SKees Cook
21788ab3820fSKees Cook# Relocation on x86 needs some additional build support
2179845adf72SH. Peter Anvinconfig X86_NEED_RELOCS
2180845adf72SH. Peter Anvin	def_bool y
21818ab3820fSKees Cook	depends on RANDOMIZE_BASE || (X86_32 && RELOCATABLE)
2182845adf72SH. Peter Anvin
2183506f1d07SSam Ravnborgconfig PHYSICAL_ALIGN
2184a0215061SKees Cook	hex "Alignment value to which kernel should be aligned"
21858ab3820fSKees Cook	default "0x200000"
2186a0215061SKees Cook	range 0x2000 0x1000000 if X86_32
2187a0215061SKees Cook	range 0x200000 0x1000000 if X86_64
2188a7f7f624SMasahiro Yamada	help
2189506f1d07SSam Ravnborg	  This value puts the alignment restrictions on physical address
2190506f1d07SSam Ravnborg	  where kernel is loaded and run from. Kernel is compiled for an
2191506f1d07SSam Ravnborg	  address which meets above alignment restriction.
2192506f1d07SSam Ravnborg
2193506f1d07SSam Ravnborg	  If bootloader loads the kernel at a non-aligned address and
2194506f1d07SSam Ravnborg	  CONFIG_RELOCATABLE is set, kernel will move itself to nearest
2195506f1d07SSam Ravnborg	  address aligned to above value and run from there.
2196506f1d07SSam Ravnborg
2197506f1d07SSam Ravnborg	  If bootloader loads the kernel at a non-aligned address and
2198506f1d07SSam Ravnborg	  CONFIG_RELOCATABLE is not set, kernel will ignore the run time
2199506f1d07SSam Ravnborg	  load address and decompress itself to the address it has been
2200506f1d07SSam Ravnborg	  compiled for and run from there. The address for which kernel is
2201506f1d07SSam Ravnborg	  compiled already meets above alignment restrictions. Hence the
2202506f1d07SSam Ravnborg	  end result is that kernel runs from a physical address meeting
2203506f1d07SSam Ravnborg	  above alignment restrictions.
2204506f1d07SSam Ravnborg
2205a0215061SKees Cook	  On 32-bit this value must be a multiple of 0x2000. On 64-bit
2206a0215061SKees Cook	  this value must be a multiple of 0x200000.
2207a0215061SKees Cook
2208506f1d07SSam Ravnborg	  Don't change this unless you know what you are doing.
2209506f1d07SSam Ravnborg
2210eedb92abSKirill A. Shutemovconfig DYNAMIC_MEMORY_LAYOUT
2211eedb92abSKirill A. Shutemov	bool
2212a7f7f624SMasahiro Yamada	help
2213eedb92abSKirill A. Shutemov	  This option makes base addresses of vmalloc and vmemmap as well as
2214eedb92abSKirill A. Shutemov	  __PAGE_OFFSET movable during boot.
2215eedb92abSKirill A. Shutemov
22160483e1faSThomas Garnierconfig RANDOMIZE_MEMORY
22170483e1faSThomas Garnier	bool "Randomize the kernel memory sections"
22180483e1faSThomas Garnier	depends on X86_64
22190483e1faSThomas Garnier	depends on RANDOMIZE_BASE
2220eedb92abSKirill A. Shutemov	select DYNAMIC_MEMORY_LAYOUT
22210483e1faSThomas Garnier	default RANDOMIZE_BASE
2222a7f7f624SMasahiro Yamada	help
22230483e1faSThomas Garnier	  Randomizes the base virtual address of kernel memory sections
22240483e1faSThomas Garnier	  (physical memory mapping, vmalloc & vmemmap). This security feature
22250483e1faSThomas Garnier	  makes exploits relying on predictable memory locations less reliable.
22260483e1faSThomas Garnier
22270483e1faSThomas Garnier	  The order of allocations remains unchanged. Entropy is generated in
22280483e1faSThomas Garnier	  the same way as RANDOMIZE_BASE. Current implementation in the optimal
22290483e1faSThomas Garnier	  configuration have in average 30,000 different possible virtual
22300483e1faSThomas Garnier	  addresses for each memory section.
22310483e1faSThomas Garnier
22326807c846SIngo Molnar	  If unsure, say Y.
22330483e1faSThomas Garnier
223490397a41SThomas Garnierconfig RANDOMIZE_MEMORY_PHYSICAL_PADDING
223590397a41SThomas Garnier	hex "Physical memory mapping padding" if EXPERT
223690397a41SThomas Garnier	depends on RANDOMIZE_MEMORY
223790397a41SThomas Garnier	default "0xa" if MEMORY_HOTPLUG
223890397a41SThomas Garnier	default "0x0"
223990397a41SThomas Garnier	range 0x1 0x40 if MEMORY_HOTPLUG
224090397a41SThomas Garnier	range 0x0 0x40
2241a7f7f624SMasahiro Yamada	help
224290397a41SThomas Garnier	  Define the padding in terabytes added to the existing physical
224390397a41SThomas Garnier	  memory size during kernel memory randomization. It is useful
224490397a41SThomas Garnier	  for memory hotplug support but reduces the entropy available for
224590397a41SThomas Garnier	  address randomization.
224690397a41SThomas Garnier
224790397a41SThomas Garnier	  If unsure, leave at the default value.
224890397a41SThomas Garnier
2249506f1d07SSam Ravnborgconfig HOTPLUG_CPU
2250bebd024eSThomas Gleixner	def_bool y
225140b31360SStephen Rothwell	depends on SMP
2252506f1d07SSam Ravnborg
225380aa1dffSFenghua Yuconfig BOOTPARAM_HOTPLUG_CPU0
225480aa1dffSFenghua Yu	bool "Set default setting of cpu0_hotpluggable"
22552c922cd0SKees Cook	depends on HOTPLUG_CPU
2256a7f7f624SMasahiro Yamada	help
225780aa1dffSFenghua Yu	  Set whether default state of cpu0_hotpluggable is on or off.
225880aa1dffSFenghua Yu
225980aa1dffSFenghua Yu	  Say Y here to enable CPU0 hotplug by default. If this switch
226080aa1dffSFenghua Yu	  is turned on, there is no need to give cpu0_hotplug kernel
226180aa1dffSFenghua Yu	  parameter and the CPU0 hotplug feature is enabled by default.
226280aa1dffSFenghua Yu
226380aa1dffSFenghua Yu	  Please note: there are two known CPU0 dependencies if you want
226480aa1dffSFenghua Yu	  to enable the CPU0 hotplug feature either by this switch or by
226580aa1dffSFenghua Yu	  cpu0_hotplug kernel parameter.
226680aa1dffSFenghua Yu
226780aa1dffSFenghua Yu	  First, resume from hibernate or suspend always starts from CPU0.
226880aa1dffSFenghua Yu	  So hibernate and suspend are prevented if CPU0 is offline.
226980aa1dffSFenghua Yu
227080aa1dffSFenghua Yu	  Second dependency is PIC interrupts always go to CPU0. CPU0 can not
227180aa1dffSFenghua Yu	  offline if any interrupt can not migrate out of CPU0. There may
227280aa1dffSFenghua Yu	  be other CPU0 dependencies.
227380aa1dffSFenghua Yu
227480aa1dffSFenghua Yu	  Please make sure the dependencies are under your control before
227580aa1dffSFenghua Yu	  you enable this feature.
227680aa1dffSFenghua Yu
227780aa1dffSFenghua Yu	  Say N if you don't want to enable CPU0 hotplug feature by default.
227880aa1dffSFenghua Yu	  You still can enable the CPU0 hotplug feature at boot by kernel
227980aa1dffSFenghua Yu	  parameter cpu0_hotplug.
228080aa1dffSFenghua Yu
2281a71c8bc5SFenghua Yuconfig DEBUG_HOTPLUG_CPU0
2282a71c8bc5SFenghua Yu	def_bool n
2283a71c8bc5SFenghua Yu	prompt "Debug CPU0 hotplug"
22842c922cd0SKees Cook	depends on HOTPLUG_CPU
2285a7f7f624SMasahiro Yamada	help
2286a71c8bc5SFenghua Yu	  Enabling this option offlines CPU0 (if CPU0 can be offlined) as
2287a71c8bc5SFenghua Yu	  soon as possible and boots up userspace with CPU0 offlined. User
2288a71c8bc5SFenghua Yu	  can online CPU0 back after boot time.
2289a71c8bc5SFenghua Yu
2290a71c8bc5SFenghua Yu	  To debug CPU0 hotplug, you need to enable CPU0 offline/online
2291a71c8bc5SFenghua Yu	  feature by either turning on CONFIG_BOOTPARAM_HOTPLUG_CPU0 during
2292a71c8bc5SFenghua Yu	  compilation or giving cpu0_hotplug kernel parameter at boot.
2293a71c8bc5SFenghua Yu
2294a71c8bc5SFenghua Yu	  If unsure, say N.
2295a71c8bc5SFenghua Yu
2296506f1d07SSam Ravnborgconfig COMPAT_VDSO
2297b0b49f26SAndy Lutomirski	def_bool n
2298b0b49f26SAndy Lutomirski	prompt "Disable the 32-bit vDSO (needed for glibc 2.3.3)"
2299953fee1dSIngo Molnar	depends on COMPAT_32
2300a7f7f624SMasahiro Yamada	help
2301b0b49f26SAndy Lutomirski	  Certain buggy versions of glibc will crash if they are
2302b0b49f26SAndy Lutomirski	  presented with a 32-bit vDSO that is not mapped at the address
2303b0b49f26SAndy Lutomirski	  indicated in its segment table.
2304e84446deSRandy Dunlap
2305b0b49f26SAndy Lutomirski	  The bug was introduced by f866314b89d56845f55e6f365e18b31ec978ec3a
2306b0b49f26SAndy Lutomirski	  and fixed by 3b3ddb4f7db98ec9e912ccdf54d35df4aa30e04a and
2307b0b49f26SAndy Lutomirski	  49ad572a70b8aeb91e57483a11dd1b77e31c4468.  Glibc 2.3.3 is
2308b0b49f26SAndy Lutomirski	  the only released version with the bug, but OpenSUSE 9
2309b0b49f26SAndy Lutomirski	  contains a buggy "glibc 2.3.2".
2310506f1d07SSam Ravnborg
2311b0b49f26SAndy Lutomirski	  The symptom of the bug is that everything crashes on startup, saying:
2312b0b49f26SAndy Lutomirski	  dl_main: Assertion `(void *) ph->p_vaddr == _rtld_local._dl_sysinfo_dso' failed!
2313b0b49f26SAndy Lutomirski
2314b0b49f26SAndy Lutomirski	  Saying Y here changes the default value of the vdso32 boot
2315b0b49f26SAndy Lutomirski	  option from 1 to 0, which turns off the 32-bit vDSO entirely.
2316b0b49f26SAndy Lutomirski	  This works around the glibc bug but hurts performance.
2317b0b49f26SAndy Lutomirski
2318b0b49f26SAndy Lutomirski	  If unsure, say N: if you are compiling your own kernel, you
2319b0b49f26SAndy Lutomirski	  are unlikely to be using a buggy version of glibc.
2320506f1d07SSam Ravnborg
23213dc33bd3SKees Cookchoice
23223dc33bd3SKees Cook	prompt "vsyscall table for legacy applications"
23233dc33bd3SKees Cook	depends on X86_64
2324625b7b7fSAndy Lutomirski	default LEGACY_VSYSCALL_XONLY
23253dc33bd3SKees Cook	help
23263dc33bd3SKees Cook	  Legacy user code that does not know how to find the vDSO expects
23273dc33bd3SKees Cook	  to be able to issue three syscalls by calling fixed addresses in
23283dc33bd3SKees Cook	  kernel space. Since this location is not randomized with ASLR,
23293dc33bd3SKees Cook	  it can be used to assist security vulnerability exploitation.
23303dc33bd3SKees Cook
23313dc33bd3SKees Cook	  This setting can be changed at boot time via the kernel command
2332bf00745eSAndy Lutomirski	  line parameter vsyscall=[emulate|xonly|none].  Emulate mode
2333bf00745eSAndy Lutomirski	  is deprecated and can only be enabled using the kernel command
2334bf00745eSAndy Lutomirski	  line.
23353dc33bd3SKees Cook
23363dc33bd3SKees Cook	  On a system with recent enough glibc (2.14 or newer) and no
23373dc33bd3SKees Cook	  static binaries, you can say None without a performance penalty
23383dc33bd3SKees Cook	  to improve security.
23393dc33bd3SKees Cook
2340bd49e16eSAndy Lutomirski	  If unsure, select "Emulate execution only".
23413dc33bd3SKees Cook
2342bd49e16eSAndy Lutomirski	config LEGACY_VSYSCALL_XONLY
2343bd49e16eSAndy Lutomirski		bool "Emulate execution only"
2344bd49e16eSAndy Lutomirski		help
2345bd49e16eSAndy Lutomirski		  The kernel traps and emulates calls into the fixed vsyscall
2346bd49e16eSAndy Lutomirski		  address mapping and does not allow reads.  This
2347bd49e16eSAndy Lutomirski		  configuration is recommended when userspace might use the
2348bd49e16eSAndy Lutomirski		  legacy vsyscall area but support for legacy binary
2349bd49e16eSAndy Lutomirski		  instrumentation of legacy code is not needed.  It mitigates
2350bd49e16eSAndy Lutomirski		  certain uses of the vsyscall area as an ASLR-bypassing
2351bd49e16eSAndy Lutomirski		  buffer.
23523dc33bd3SKees Cook
23533dc33bd3SKees Cook	config LEGACY_VSYSCALL_NONE
23543dc33bd3SKees Cook		bool "None"
23553dc33bd3SKees Cook		help
23563dc33bd3SKees Cook		  There will be no vsyscall mapping at all. This will
23573dc33bd3SKees Cook		  eliminate any risk of ASLR bypass due to the vsyscall
23583dc33bd3SKees Cook		  fixed address mapping. Attempts to use the vsyscalls
23593dc33bd3SKees Cook		  will be reported to dmesg, so that either old or
23603dc33bd3SKees Cook		  malicious userspace programs can be identified.
23613dc33bd3SKees Cook
23623dc33bd3SKees Cookendchoice
23633dc33bd3SKees Cook
2364516cbf37STim Birdconfig CMDLINE_BOOL
2365516cbf37STim Bird	bool "Built-in kernel command line"
2366a7f7f624SMasahiro Yamada	help
2367516cbf37STim Bird	  Allow for specifying boot arguments to the kernel at
2368516cbf37STim Bird	  build time.  On some systems (e.g. embedded ones), it is
2369516cbf37STim Bird	  necessary or convenient to provide some or all of the
2370516cbf37STim Bird	  kernel boot arguments with the kernel itself (that is,
2371516cbf37STim Bird	  to not rely on the boot loader to provide them.)
2372516cbf37STim Bird
2373516cbf37STim Bird	  To compile command line arguments into the kernel,
2374516cbf37STim Bird	  set this option to 'Y', then fill in the
237569711ca1SSébastien Hinderer	  boot arguments in CONFIG_CMDLINE.
2376516cbf37STim Bird
2377516cbf37STim Bird	  Systems with fully functional boot loaders (i.e. non-embedded)
2378516cbf37STim Bird	  should leave this option set to 'N'.
2379516cbf37STim Bird
2380516cbf37STim Birdconfig CMDLINE
2381516cbf37STim Bird	string "Built-in kernel command string"
2382516cbf37STim Bird	depends on CMDLINE_BOOL
2383516cbf37STim Bird	default ""
2384a7f7f624SMasahiro Yamada	help
2385516cbf37STim Bird	  Enter arguments here that should be compiled into the kernel
2386516cbf37STim Bird	  image and used at boot time.  If the boot loader provides a
2387516cbf37STim Bird	  command line at boot time, it is appended to this string to
2388516cbf37STim Bird	  form the full kernel command line, when the system boots.
2389516cbf37STim Bird
2390516cbf37STim Bird	  However, you can use the CONFIG_CMDLINE_OVERRIDE option to
2391516cbf37STim Bird	  change this behavior.
2392516cbf37STim Bird
2393516cbf37STim Bird	  In most cases, the command line (whether built-in or provided
2394516cbf37STim Bird	  by the boot loader) should specify the device for the root
2395516cbf37STim Bird	  file system.
2396516cbf37STim Bird
2397516cbf37STim Birdconfig CMDLINE_OVERRIDE
2398516cbf37STim Bird	bool "Built-in command line overrides boot loader arguments"
2399645e6466SAnders Roxell	depends on CMDLINE_BOOL && CMDLINE != ""
2400a7f7f624SMasahiro Yamada	help
2401516cbf37STim Bird	  Set this option to 'Y' to have the kernel ignore the boot loader
2402516cbf37STim Bird	  command line, and use ONLY the built-in command line.
2403516cbf37STim Bird
2404516cbf37STim Bird	  This is used to work around broken boot loaders.  This should
2405516cbf37STim Bird	  be set to 'N' under normal conditions.
2406516cbf37STim Bird
2407a5b9e5a2SAndy Lutomirskiconfig MODIFY_LDT_SYSCALL
2408a5b9e5a2SAndy Lutomirski	bool "Enable the LDT (local descriptor table)" if EXPERT
2409a5b9e5a2SAndy Lutomirski	default y
2410a7f7f624SMasahiro Yamada	help
2411a5b9e5a2SAndy Lutomirski	  Linux can allow user programs to install a per-process x86
2412a5b9e5a2SAndy Lutomirski	  Local Descriptor Table (LDT) using the modify_ldt(2) system
2413a5b9e5a2SAndy Lutomirski	  call.  This is required to run 16-bit or segmented code such as
2414a5b9e5a2SAndy Lutomirski	  DOSEMU or some Wine programs.  It is also used by some very old
2415a5b9e5a2SAndy Lutomirski	  threading libraries.
2416a5b9e5a2SAndy Lutomirski
2417a5b9e5a2SAndy Lutomirski	  Enabling this feature adds a small amount of overhead to
2418a5b9e5a2SAndy Lutomirski	  context switches and increases the low-level kernel attack
2419a5b9e5a2SAndy Lutomirski	  surface.  Disabling it removes the modify_ldt(2) system call.
2420a5b9e5a2SAndy Lutomirski
2421a5b9e5a2SAndy Lutomirski	  Saying 'N' here may make sense for embedded or server kernels.
2422a5b9e5a2SAndy Lutomirski
24233aac3ebeSThomas Gleixnerconfig STRICT_SIGALTSTACK_SIZE
24243aac3ebeSThomas Gleixner	bool "Enforce strict size checking for sigaltstack"
24253aac3ebeSThomas Gleixner	depends on DYNAMIC_SIGFRAME
24263aac3ebeSThomas Gleixner	help
24273aac3ebeSThomas Gleixner	  For historical reasons MINSIGSTKSZ is a constant which became
24283aac3ebeSThomas Gleixner	  already too small with AVX512 support. Add a mechanism to
24293aac3ebeSThomas Gleixner	  enforce strict checking of the sigaltstack size against the
24303aac3ebeSThomas Gleixner	  real size of the FPU frame. This option enables the check
24313aac3ebeSThomas Gleixner	  by default. It can also be controlled via the kernel command
24323aac3ebeSThomas Gleixner	  line option 'strict_sas_size' independent of this config
24333aac3ebeSThomas Gleixner	  switch. Enabling it might break existing applications which
24343aac3ebeSThomas Gleixner	  allocate a too small sigaltstack but 'work' because they
24353aac3ebeSThomas Gleixner	  never get a signal delivered.
24363aac3ebeSThomas Gleixner
24373aac3ebeSThomas Gleixner	  Say 'N' unless you want to really enforce this check.
24383aac3ebeSThomas Gleixner
2439b700e7f0SSeth Jenningssource "kernel/livepatch/Kconfig"
2440b700e7f0SSeth Jennings
2441506f1d07SSam Ravnborgendmenu
2442506f1d07SSam Ravnborg
2443f43b9876SPeter Zijlstraconfig CC_HAS_SLS
2444f43b9876SPeter Zijlstra	def_bool $(cc-option,-mharden-sls=all)
2445f43b9876SPeter Zijlstra
2446f43b9876SPeter Zijlstraconfig CC_HAS_RETURN_THUNK
2447f43b9876SPeter Zijlstra	def_bool $(cc-option,-mfunction-return=thunk-extern)
2448f43b9876SPeter Zijlstra
2449f43b9876SPeter Zijlstramenuconfig SPECULATION_MITIGATIONS
2450f43b9876SPeter Zijlstra	bool "Mitigations for speculative execution vulnerabilities"
2451f43b9876SPeter Zijlstra	default y
2452f43b9876SPeter Zijlstra	help
2453f43b9876SPeter Zijlstra	  Say Y here to enable options which enable mitigations for
2454f43b9876SPeter Zijlstra	  speculative execution hardware vulnerabilities.
2455f43b9876SPeter Zijlstra
2456f43b9876SPeter Zijlstra	  If you say N, all mitigations will be disabled. You really
2457f43b9876SPeter Zijlstra	  should know what you are doing to say so.
2458f43b9876SPeter Zijlstra
2459f43b9876SPeter Zijlstraif SPECULATION_MITIGATIONS
2460f43b9876SPeter Zijlstra
2461f43b9876SPeter Zijlstraconfig PAGE_TABLE_ISOLATION
2462f43b9876SPeter Zijlstra	bool "Remove the kernel mapping in user mode"
2463f43b9876SPeter Zijlstra	default y
2464f43b9876SPeter Zijlstra	depends on (X86_64 || X86_PAE)
2465f43b9876SPeter Zijlstra	help
2466f43b9876SPeter Zijlstra	  This feature reduces the number of hardware side channels by
2467f43b9876SPeter Zijlstra	  ensuring that the majority of kernel addresses are not mapped
2468f43b9876SPeter Zijlstra	  into userspace.
2469f43b9876SPeter Zijlstra
2470f43b9876SPeter Zijlstra	  See Documentation/x86/pti.rst for more details.
2471f43b9876SPeter Zijlstra
2472f43b9876SPeter Zijlstraconfig RETPOLINE
2473f43b9876SPeter Zijlstra	bool "Avoid speculative indirect branches in kernel"
2474f43b9876SPeter Zijlstra	select OBJTOOL if HAVE_OBJTOOL
2475f43b9876SPeter Zijlstra	default y
2476f43b9876SPeter Zijlstra	help
2477f43b9876SPeter Zijlstra	  Compile kernel with the retpoline compiler options to guard against
2478f43b9876SPeter Zijlstra	  kernel-to-user data leaks by avoiding speculative indirect
2479f43b9876SPeter Zijlstra	  branches. Requires a compiler with -mindirect-branch=thunk-extern
2480f43b9876SPeter Zijlstra	  support for full protection. The kernel may run slower.
2481f43b9876SPeter Zijlstra
2482f43b9876SPeter Zijlstraconfig RETHUNK
2483f43b9876SPeter Zijlstra	bool "Enable return-thunks"
2484f43b9876SPeter Zijlstra	depends on RETPOLINE && CC_HAS_RETURN_THUNK
2485f43b9876SPeter Zijlstra	select OBJTOOL if HAVE_OBJTOOL
2486b648ab48SBen Hutchings	default y if X86_64
2487f43b9876SPeter Zijlstra	help
2488f43b9876SPeter Zijlstra	  Compile the kernel with the return-thunks compiler option to guard
2489f43b9876SPeter Zijlstra	  against kernel-to-user data leaks by avoiding return speculation.
2490f43b9876SPeter Zijlstra	  Requires a compiler with -mfunction-return=thunk-extern
2491f43b9876SPeter Zijlstra	  support for full protection. The kernel may run slower.
2492f43b9876SPeter Zijlstra
2493f43b9876SPeter Zijlstraconfig CPU_UNRET_ENTRY
2494f43b9876SPeter Zijlstra	bool "Enable UNRET on kernel entry"
2495b648ab48SBen Hutchings	depends on CPU_SUP_AMD && RETHUNK && X86_64
2496f43b9876SPeter Zijlstra	default y
2497f43b9876SPeter Zijlstra	help
2498f43b9876SPeter Zijlstra	  Compile the kernel with support for the retbleed=unret mitigation.
2499f43b9876SPeter Zijlstra
2500f43b9876SPeter Zijlstraconfig CPU_IBPB_ENTRY
2501f43b9876SPeter Zijlstra	bool "Enable IBPB on kernel entry"
2502b648ab48SBen Hutchings	depends on CPU_SUP_AMD && X86_64
2503f43b9876SPeter Zijlstra	default y
2504f43b9876SPeter Zijlstra	help
2505f43b9876SPeter Zijlstra	  Compile the kernel with support for the retbleed=ibpb mitigation.
2506f43b9876SPeter Zijlstra
2507f43b9876SPeter Zijlstraconfig CPU_IBRS_ENTRY
2508f43b9876SPeter Zijlstra	bool "Enable IBRS on kernel entry"
2509b648ab48SBen Hutchings	depends on CPU_SUP_INTEL && X86_64
2510f43b9876SPeter Zijlstra	default y
2511f43b9876SPeter Zijlstra	help
2512f43b9876SPeter Zijlstra	  Compile the kernel with support for the spectre_v2=ibrs mitigation.
2513f43b9876SPeter Zijlstra	  This mitigates both spectre_v2 and retbleed at great cost to
2514f43b9876SPeter Zijlstra	  performance.
2515f43b9876SPeter Zijlstra
2516f43b9876SPeter Zijlstraconfig SLS
2517f43b9876SPeter Zijlstra	bool "Mitigate Straight-Line-Speculation"
2518f43b9876SPeter Zijlstra	depends on CC_HAS_SLS && X86_64
2519f43b9876SPeter Zijlstra	select OBJTOOL if HAVE_OBJTOOL
2520f43b9876SPeter Zijlstra	default n
2521f43b9876SPeter Zijlstra	help
2522f43b9876SPeter Zijlstra	  Compile the kernel with straight-line-speculation options to guard
2523f43b9876SPeter Zijlstra	  against straight line speculation. The kernel image might be slightly
2524f43b9876SPeter Zijlstra	  larger.
2525f43b9876SPeter Zijlstra
2526f43b9876SPeter Zijlstraendif
2527f43b9876SPeter Zijlstra
25283072e413SMichal Hockoconfig ARCH_HAS_ADD_PAGES
25293072e413SMichal Hocko	def_bool y
25305c11f00bSDavid Hildenbrand	depends on ARCH_ENABLE_MEMORY_HOTPLUG
25313072e413SMichal Hocko
2532f91ef222SOscar Salvadorconfig ARCH_MHP_MEMMAP_ON_MEMORY_ENABLE
2533f91ef222SOscar Salvador	def_bool y
2534f91ef222SOscar Salvador
2535da85f865SBjorn Helgaasmenu "Power management and ACPI options"
2536e279b6c1SSam Ravnborg
2537e279b6c1SSam Ravnborgconfig ARCH_HIBERNATION_HEADER
25383c2362e6SHarvey Harrison	def_bool y
253944556530SZhimin Gu	depends on HIBERNATION
2540e279b6c1SSam Ravnborg
2541e279b6c1SSam Ravnborgsource "kernel/power/Kconfig"
2542e279b6c1SSam Ravnborg
2543e279b6c1SSam Ravnborgsource "drivers/acpi/Kconfig"
2544e279b6c1SSam Ravnborg
2545a6b68076SAndi Kleenconfig X86_APM_BOOT
25466fc108a0SJan Beulich	def_bool y
2547282e5aabSPaul Bolle	depends on APM
2548a6b68076SAndi Kleen
2549e279b6c1SSam Ravnborgmenuconfig APM
2550e279b6c1SSam Ravnborg	tristate "APM (Advanced Power Management) BIOS support"
2551efefa6f6SIngo Molnar	depends on X86_32 && PM_SLEEP
2552a7f7f624SMasahiro Yamada	help
2553e279b6c1SSam Ravnborg	  APM is a BIOS specification for saving power using several different
2554e279b6c1SSam Ravnborg	  techniques. This is mostly useful for battery powered laptops with
2555e279b6c1SSam Ravnborg	  APM compliant BIOSes. If you say Y here, the system time will be
2556e279b6c1SSam Ravnborg	  reset after a RESUME operation, the /proc/apm device will provide
2557e279b6c1SSam Ravnborg	  battery status information, and user-space programs will receive
2558e279b6c1SSam Ravnborg	  notification of APM "events" (e.g. battery status change).
2559e279b6c1SSam Ravnborg
2560e279b6c1SSam Ravnborg	  If you select "Y" here, you can disable actual use of the APM
2561e279b6c1SSam Ravnborg	  BIOS by passing the "apm=off" option to the kernel at boot time.
2562e279b6c1SSam Ravnborg
2563e279b6c1SSam Ravnborg	  Note that the APM support is almost completely disabled for
2564e279b6c1SSam Ravnborg	  machines with more than one CPU.
2565e279b6c1SSam Ravnborg
2566e279b6c1SSam Ravnborg	  In order to use APM, you will need supporting software. For location
2567151f4e2bSMauro Carvalho Chehab	  and more information, read <file:Documentation/power/apm-acpi.rst>
25682dc98fd3SMichael Witten	  and the Battery Powered Linux mini-HOWTO, available from
2569e279b6c1SSam Ravnborg	  <http://www.tldp.org/docs.html#howto>.
2570e279b6c1SSam Ravnborg
2571e279b6c1SSam Ravnborg	  This driver does not spin down disk drives (see the hdparm(8)
2572e279b6c1SSam Ravnborg	  manpage ("man 8 hdparm") for that), and it doesn't turn off
2573e279b6c1SSam Ravnborg	  VESA-compliant "green" monitors.
2574e279b6c1SSam Ravnborg
2575e279b6c1SSam Ravnborg	  This driver does not support the TI 4000M TravelMate and the ACER
2576e279b6c1SSam Ravnborg	  486/DX4/75 because they don't have compliant BIOSes. Many "green"
2577e279b6c1SSam Ravnborg	  desktop machines also don't have compliant BIOSes, and this driver
2578e279b6c1SSam Ravnborg	  may cause those machines to panic during the boot phase.
2579e279b6c1SSam Ravnborg
2580e279b6c1SSam Ravnborg	  Generally, if you don't have a battery in your machine, there isn't
2581e279b6c1SSam Ravnborg	  much point in using this driver and you should say N. If you get
2582e279b6c1SSam Ravnborg	  random kernel OOPSes or reboots that don't seem to be related to
2583e279b6c1SSam Ravnborg	  anything, try disabling/enabling this option (or disabling/enabling
2584e279b6c1SSam Ravnborg	  APM in your BIOS).
2585e279b6c1SSam Ravnborg
2586e279b6c1SSam Ravnborg	  Some other things you should try when experiencing seemingly random,
2587e279b6c1SSam Ravnborg	  "weird" problems:
2588e279b6c1SSam Ravnborg
2589e279b6c1SSam Ravnborg	  1) make sure that you have enough swap space and that it is
2590e279b6c1SSam Ravnborg	  enabled.
25917987448fSStephen Kitt	  2) pass the "idle=poll" option to the kernel
2592e279b6c1SSam Ravnborg	  3) switch on floating point emulation in the kernel and pass
2593e279b6c1SSam Ravnborg	  the "no387" option to the kernel
2594e279b6c1SSam Ravnborg	  4) pass the "floppy=nodma" option to the kernel
2595e279b6c1SSam Ravnborg	  5) pass the "mem=4M" option to the kernel (thereby disabling
2596e279b6c1SSam Ravnborg	  all but the first 4 MB of RAM)
2597e279b6c1SSam Ravnborg	  6) make sure that the CPU is not over clocked.
2598e279b6c1SSam Ravnborg	  7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/>
2599e279b6c1SSam Ravnborg	  8) disable the cache from your BIOS settings
2600e279b6c1SSam Ravnborg	  9) install a fan for the video card or exchange video RAM
2601e279b6c1SSam Ravnborg	  10) install a better fan for the CPU
2602e279b6c1SSam Ravnborg	  11) exchange RAM chips
2603e279b6c1SSam Ravnborg	  12) exchange the motherboard.
2604e279b6c1SSam Ravnborg
2605e279b6c1SSam Ravnborg	  To compile this driver as a module, choose M here: the
2606e279b6c1SSam Ravnborg	  module will be called apm.
2607e279b6c1SSam Ravnborg
2608e279b6c1SSam Ravnborgif APM
2609e279b6c1SSam Ravnborg
2610e279b6c1SSam Ravnborgconfig APM_IGNORE_USER_SUSPEND
2611e279b6c1SSam Ravnborg	bool "Ignore USER SUSPEND"
2612a7f7f624SMasahiro Yamada	help
2613e279b6c1SSam Ravnborg	  This option will ignore USER SUSPEND requests. On machines with a
2614e279b6c1SSam Ravnborg	  compliant APM BIOS, you want to say N. However, on the NEC Versa M
2615e279b6c1SSam Ravnborg	  series notebooks, it is necessary to say Y because of a BIOS bug.
2616e279b6c1SSam Ravnborg
2617e279b6c1SSam Ravnborgconfig APM_DO_ENABLE
2618e279b6c1SSam Ravnborg	bool "Enable PM at boot time"
2619a7f7f624SMasahiro Yamada	help
2620e279b6c1SSam Ravnborg	  Enable APM features at boot time. From page 36 of the APM BIOS
2621e279b6c1SSam Ravnborg	  specification: "When disabled, the APM BIOS does not automatically
2622e279b6c1SSam Ravnborg	  power manage devices, enter the Standby State, enter the Suspend
2623e279b6c1SSam Ravnborg	  State, or take power saving steps in response to CPU Idle calls."
2624e279b6c1SSam Ravnborg	  This driver will make CPU Idle calls when Linux is idle (unless this
2625e279b6c1SSam Ravnborg	  feature is turned off -- see "Do CPU IDLE calls", below). This
2626e279b6c1SSam Ravnborg	  should always save battery power, but more complicated APM features
2627e279b6c1SSam Ravnborg	  will be dependent on your BIOS implementation. You may need to turn
2628e279b6c1SSam Ravnborg	  this option off if your computer hangs at boot time when using APM
2629e279b6c1SSam Ravnborg	  support, or if it beeps continuously instead of suspending. Turn
2630e279b6c1SSam Ravnborg	  this off if you have a NEC UltraLite Versa 33/C or a Toshiba
2631e279b6c1SSam Ravnborg	  T400CDT. This is off by default since most machines do fine without
2632e279b6c1SSam Ravnborg	  this feature.
2633e279b6c1SSam Ravnborg
2634e279b6c1SSam Ravnborgconfig APM_CPU_IDLE
2635dd8af076SLen Brown	depends on CPU_IDLE
2636e279b6c1SSam Ravnborg	bool "Make CPU Idle calls when idle"
2637a7f7f624SMasahiro Yamada	help
2638e279b6c1SSam Ravnborg	  Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop.
2639e279b6c1SSam Ravnborg	  On some machines, this can activate improved power savings, such as
2640e279b6c1SSam Ravnborg	  a slowed CPU clock rate, when the machine is idle. These idle calls
2641e279b6c1SSam Ravnborg	  are made after the idle loop has run for some length of time (e.g.,
2642e279b6c1SSam Ravnborg	  333 mS). On some machines, this will cause a hang at boot time or
2643e279b6c1SSam Ravnborg	  whenever the CPU becomes idle. (On machines with more than one CPU,
2644e279b6c1SSam Ravnborg	  this option does nothing.)
2645e279b6c1SSam Ravnborg
2646e279b6c1SSam Ravnborgconfig APM_DISPLAY_BLANK
2647e279b6c1SSam Ravnborg	bool "Enable console blanking using APM"
2648a7f7f624SMasahiro Yamada	help
2649e279b6c1SSam Ravnborg	  Enable console blanking using the APM. Some laptops can use this to
2650e279b6c1SSam Ravnborg	  turn off the LCD backlight when the screen blanker of the Linux
2651e279b6c1SSam Ravnborg	  virtual console blanks the screen. Note that this is only used by
2652e279b6c1SSam Ravnborg	  the virtual console screen blanker, and won't turn off the backlight
2653e279b6c1SSam Ravnborg	  when using the X Window system. This also doesn't have anything to
2654e279b6c1SSam Ravnborg	  do with your VESA-compliant power-saving monitor. Further, this
2655e279b6c1SSam Ravnborg	  option doesn't work for all laptops -- it might not turn off your
2656e279b6c1SSam Ravnborg	  backlight at all, or it might print a lot of errors to the console,
2657e279b6c1SSam Ravnborg	  especially if you are using gpm.
2658e279b6c1SSam Ravnborg
2659e279b6c1SSam Ravnborgconfig APM_ALLOW_INTS
2660e279b6c1SSam Ravnborg	bool "Allow interrupts during APM BIOS calls"
2661a7f7f624SMasahiro Yamada	help
2662e279b6c1SSam Ravnborg	  Normally we disable external interrupts while we are making calls to
2663e279b6c1SSam Ravnborg	  the APM BIOS as a measure to lessen the effects of a badly behaving
2664e279b6c1SSam Ravnborg	  BIOS implementation.  The BIOS should reenable interrupts if it
2665e279b6c1SSam Ravnborg	  needs to.  Unfortunately, some BIOSes do not -- especially those in
2666e279b6c1SSam Ravnborg	  many of the newer IBM Thinkpads.  If you experience hangs when you
2667e279b6c1SSam Ravnborg	  suspend, try setting this to Y.  Otherwise, say N.
2668e279b6c1SSam Ravnborg
2669e279b6c1SSam Ravnborgendif # APM
2670e279b6c1SSam Ravnborg
2671bb0a56ecSDave Jonessource "drivers/cpufreq/Kconfig"
2672e279b6c1SSam Ravnborg
2673e279b6c1SSam Ravnborgsource "drivers/cpuidle/Kconfig"
2674e279b6c1SSam Ravnborg
267527471fdbSAndy Henroidsource "drivers/idle/Kconfig"
267627471fdbSAndy Henroid
2677e279b6c1SSam Ravnborgendmenu
2678e279b6c1SSam Ravnborg
2679e279b6c1SSam Ravnborgmenu "Bus options (PCI etc.)"
2680e279b6c1SSam Ravnborg
2681e279b6c1SSam Ravnborgchoice
2682e279b6c1SSam Ravnborg	prompt "PCI access mode"
2683efefa6f6SIngo Molnar	depends on X86_32 && PCI
2684e279b6c1SSam Ravnborg	default PCI_GOANY
2685a7f7f624SMasahiro Yamada	help
2686e279b6c1SSam Ravnborg	  On PCI systems, the BIOS can be used to detect the PCI devices and
2687e279b6c1SSam Ravnborg	  determine their configuration. However, some old PCI motherboards
2688e279b6c1SSam Ravnborg	  have BIOS bugs and may crash if this is done. Also, some embedded
2689e279b6c1SSam Ravnborg	  PCI-based systems don't have any BIOS at all. Linux can also try to
2690e279b6c1SSam Ravnborg	  detect the PCI hardware directly without using the BIOS.
2691e279b6c1SSam Ravnborg
2692e279b6c1SSam Ravnborg	  With this option, you can specify how Linux should detect the
2693e279b6c1SSam Ravnborg	  PCI devices. If you choose "BIOS", the BIOS will be used,
2694e279b6c1SSam Ravnborg	  if you choose "Direct", the BIOS won't be used, and if you
2695e279b6c1SSam Ravnborg	  choose "MMConfig", then PCI Express MMCONFIG will be used.
2696e279b6c1SSam Ravnborg	  If you choose "Any", the kernel will try MMCONFIG, then the
2697e279b6c1SSam Ravnborg	  direct access method and falls back to the BIOS if that doesn't
2698e279b6c1SSam Ravnborg	  work. If unsure, go with the default, which is "Any".
2699e279b6c1SSam Ravnborg
2700e279b6c1SSam Ravnborgconfig PCI_GOBIOS
2701e279b6c1SSam Ravnborg	bool "BIOS"
2702e279b6c1SSam Ravnborg
2703e279b6c1SSam Ravnborgconfig PCI_GOMMCONFIG
2704e279b6c1SSam Ravnborg	bool "MMConfig"
2705e279b6c1SSam Ravnborg
2706e279b6c1SSam Ravnborgconfig PCI_GODIRECT
2707e279b6c1SSam Ravnborg	bool "Direct"
2708e279b6c1SSam Ravnborg
27093ef0e1f8SAndres Salomonconfig PCI_GOOLPC
271076fb6570SDaniel Drake	bool "OLPC XO-1"
27113ef0e1f8SAndres Salomon	depends on OLPC
27123ef0e1f8SAndres Salomon
27132bdd1b03SAndres Salomonconfig PCI_GOANY
27142bdd1b03SAndres Salomon	bool "Any"
27152bdd1b03SAndres Salomon
2716e279b6c1SSam Ravnborgendchoice
2717e279b6c1SSam Ravnborg
2718e279b6c1SSam Ravnborgconfig PCI_BIOS
27193c2362e6SHarvey Harrison	def_bool y
2720efefa6f6SIngo Molnar	depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY)
2721e279b6c1SSam Ravnborg
2722e279b6c1SSam Ravnborg# x86-64 doesn't support PCI BIOS access from long mode so always go direct.
2723e279b6c1SSam Ravnborgconfig PCI_DIRECT
27243c2362e6SHarvey Harrison	def_bool y
27250aba496fSShaohua Li	depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC || PCI_GOMMCONFIG))
2726e279b6c1SSam Ravnborg
2727e279b6c1SSam Ravnborgconfig PCI_MMCONFIG
2728b45c9f36SJan Kiszka	bool "Support mmconfig PCI config space access" if X86_64
2729b45c9f36SJan Kiszka	default y
27304590d98fSAndy Shevchenko	depends on PCI && (ACPI || JAILHOUSE_GUEST)
2731b45c9f36SJan Kiszka	depends on X86_64 || (PCI_GOANY || PCI_GOMMCONFIG)
2732e279b6c1SSam Ravnborg
27333ef0e1f8SAndres Salomonconfig PCI_OLPC
27342bdd1b03SAndres Salomon	def_bool y
27352bdd1b03SAndres Salomon	depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY)
27363ef0e1f8SAndres Salomon
2737b5401a96SAlex Nixonconfig PCI_XEN
2738b5401a96SAlex Nixon	def_bool y
2739b5401a96SAlex Nixon	depends on PCI && XEN
2740b5401a96SAlex Nixon
27418364e1f8SJan Kiszkaconfig MMCONF_FAM10H
27428364e1f8SJan Kiszka	def_bool y
27438364e1f8SJan Kiszka	depends on X86_64 && PCI_MMCONFIG && ACPI
2744e279b6c1SSam Ravnborg
27453f6ea84aSIra W. Snyderconfig PCI_CNB20LE_QUIRK
27466a108a14SDavid Rientjes	bool "Read CNB20LE Host Bridge Windows" if EXPERT
27476ea30386SKees Cook	depends on PCI
27483f6ea84aSIra W. Snyder	help
27493f6ea84aSIra W. Snyder	  Read the PCI windows out of the CNB20LE host bridge. This allows
27503f6ea84aSIra W. Snyder	  PCI hotplug to work on systems with the CNB20LE chipset which do
27513f6ea84aSIra W. Snyder	  not have ACPI.
27523f6ea84aSIra W. Snyder
275364a5fed6SBjorn Helgaas	  There's no public spec for this chipset, and this functionality
275464a5fed6SBjorn Helgaas	  is known to be incomplete.
275564a5fed6SBjorn Helgaas
275664a5fed6SBjorn Helgaas	  You should say N unless you know you need this.
275764a5fed6SBjorn Helgaas
27583a495511SWilliam Breathitt Grayconfig ISA_BUS
275917a2a129SWilliam Breathitt Gray	bool "ISA bus support on modern systems" if EXPERT
27603a495511SWilliam Breathitt Gray	help
276117a2a129SWilliam Breathitt Gray	  Expose ISA bus device drivers and options available for selection and
276217a2a129SWilliam Breathitt Gray	  configuration. Enable this option if your target machine has an ISA
276317a2a129SWilliam Breathitt Gray	  bus. ISA is an older system, displaced by PCI and newer bus
276417a2a129SWilliam Breathitt Gray	  architectures -- if your target machine is modern, it probably does
276517a2a129SWilliam Breathitt Gray	  not have an ISA bus.
27663a495511SWilliam Breathitt Gray
27673a495511SWilliam Breathitt Gray	  If unsure, say N.
27683a495511SWilliam Breathitt Gray
27691c00f016SDavid Rientjes# x86_64 have no ISA slots, but can have ISA-style DMA.
2770e279b6c1SSam Ravnborgconfig ISA_DMA_API
27711c00f016SDavid Rientjes	bool "ISA-style DMA support" if (X86_64 && EXPERT)
27721c00f016SDavid Rientjes	default y
27731c00f016SDavid Rientjes	help
27741c00f016SDavid Rientjes	  Enables ISA-style DMA support for devices requiring such controllers.
27751c00f016SDavid Rientjes	  If unsure, say Y.
2776e279b6c1SSam Ravnborg
277751e68d05SLinus Torvaldsif X86_32
277851e68d05SLinus Torvalds
2779e279b6c1SSam Ravnborgconfig ISA
2780e279b6c1SSam Ravnborg	bool "ISA support"
2781a7f7f624SMasahiro Yamada	help
2782e279b6c1SSam Ravnborg	  Find out whether you have ISA slots on your motherboard.  ISA is the
2783e279b6c1SSam Ravnborg	  name of a bus system, i.e. the way the CPU talks to the other stuff
2784e279b6c1SSam Ravnborg	  inside your box.  Other bus systems are PCI, EISA, MicroChannel
2785e279b6c1SSam Ravnborg	  (MCA) or VESA.  ISA is an older system, now being displaced by PCI;
2786e279b6c1SSam Ravnborg	  newer boards don't support it.  If you have ISA, say Y, otherwise N.
2787e279b6c1SSam Ravnborg
2788e279b6c1SSam Ravnborgconfig SCx200
2789e279b6c1SSam Ravnborg	tristate "NatSemi SCx200 support"
2790a7f7f624SMasahiro Yamada	help
2791e279b6c1SSam Ravnborg	  This provides basic support for National Semiconductor's
2792e279b6c1SSam Ravnborg	  (now AMD's) Geode processors.  The driver probes for the
2793e279b6c1SSam Ravnborg	  PCI-IDs of several on-chip devices, so its a good dependency
2794e279b6c1SSam Ravnborg	  for other scx200_* drivers.
2795e279b6c1SSam Ravnborg
2796e279b6c1SSam Ravnborg	  If compiled as a module, the driver is named scx200.
2797e279b6c1SSam Ravnborg
2798e279b6c1SSam Ravnborgconfig SCx200HR_TIMER
2799e279b6c1SSam Ravnborg	tristate "NatSemi SCx200 27MHz High-Resolution Timer Support"
2800592913ecSJohn Stultz	depends on SCx200
2801e279b6c1SSam Ravnborg	default y
2802a7f7f624SMasahiro Yamada	help
2803e279b6c1SSam Ravnborg	  This driver provides a clocksource built upon the on-chip
2804e279b6c1SSam Ravnborg	  27MHz high-resolution timer.  Its also a workaround for
2805e279b6c1SSam Ravnborg	  NSC Geode SC-1100's buggy TSC, which loses time when the
2806e279b6c1SSam Ravnborg	  processor goes idle (as is done by the scheduler).  The
2807e279b6c1SSam Ravnborg	  other workaround is idle=poll boot option.
2808e279b6c1SSam Ravnborg
28093ef0e1f8SAndres Salomonconfig OLPC
28103ef0e1f8SAndres Salomon	bool "One Laptop Per Child support"
281154008979SThomas Gleixner	depends on !X86_PAE
28123c554946SAndres Salomon	select GPIOLIB
2813dc3119e7SThomas Gleixner	select OF
281445bb1674SDaniel Drake	select OF_PROMTREE
2815b4e51854SGrant Likely	select IRQ_DOMAIN
28160c3d931bSLubomir Rintel	select OLPC_EC
2817a7f7f624SMasahiro Yamada	help
28183ef0e1f8SAndres Salomon	  Add support for detecting the unique features of the OLPC
28193ef0e1f8SAndres Salomon	  XO hardware.
28203ef0e1f8SAndres Salomon
2821a3128588SDaniel Drakeconfig OLPC_XO1_PM
2822a3128588SDaniel Drake	bool "OLPC XO-1 Power Management"
2823fa112cf1SBorislav Petkov	depends on OLPC && MFD_CS5535=y && PM_SLEEP
2824a7f7f624SMasahiro Yamada	help
282597c4cb71SDaniel Drake	  Add support for poweroff and suspend of the OLPC XO-1 laptop.
2826bf1ebf00SDaniel Drake
2827cfee9597SDaniel Drakeconfig OLPC_XO1_RTC
2828cfee9597SDaniel Drake	bool "OLPC XO-1 Real Time Clock"
2829cfee9597SDaniel Drake	depends on OLPC_XO1_PM && RTC_DRV_CMOS
2830a7f7f624SMasahiro Yamada	help
2831cfee9597SDaniel Drake	  Add support for the XO-1 real time clock, which can be used as a
2832cfee9597SDaniel Drake	  programmable wakeup source.
2833cfee9597SDaniel Drake
28347feda8e9SDaniel Drakeconfig OLPC_XO1_SCI
28357feda8e9SDaniel Drake	bool "OLPC XO-1 SCI extras"
283692e830f2SArnd Bergmann	depends on OLPC && OLPC_XO1_PM && GPIO_CS5535=y
2837ed8e47feSRandy Dunlap	depends on INPUT=y
2838d8d01a63SDaniel Drake	select POWER_SUPPLY
2839a7f7f624SMasahiro Yamada	help
28407feda8e9SDaniel Drake	  Add support for SCI-based features of the OLPC XO-1 laptop:
28417bc74b3dSDaniel Drake	   - EC-driven system wakeups
28427feda8e9SDaniel Drake	   - Power button
28437bc74b3dSDaniel Drake	   - Ebook switch
28442cf2baeaSDaniel Drake	   - Lid switch
2845e1040ac6SDaniel Drake	   - AC adapter status updates
2846e1040ac6SDaniel Drake	   - Battery status updates
28477feda8e9SDaniel Drake
2848a0f30f59SDaniel Drakeconfig OLPC_XO15_SCI
2849a0f30f59SDaniel Drake	bool "OLPC XO-1.5 SCI extras"
2850d8d01a63SDaniel Drake	depends on OLPC && ACPI
2851d8d01a63SDaniel Drake	select POWER_SUPPLY
2852a7f7f624SMasahiro Yamada	help
2853a0f30f59SDaniel Drake	  Add support for SCI-based features of the OLPC XO-1.5 laptop:
2854a0f30f59SDaniel Drake	   - EC-driven system wakeups
2855a0f30f59SDaniel Drake	   - AC adapter status updates
2856a0f30f59SDaniel Drake	   - Battery status updates
2857e279b6c1SSam Ravnborg
2858d4f3e350SEd Wildgooseconfig ALIX
2859d4f3e350SEd Wildgoose	bool "PCEngines ALIX System Support (LED setup)"
2860d4f3e350SEd Wildgoose	select GPIOLIB
2861a7f7f624SMasahiro Yamada	help
2862d4f3e350SEd Wildgoose	  This option enables system support for the PCEngines ALIX.
2863d4f3e350SEd Wildgoose	  At present this just sets up LEDs for GPIO control on
2864d4f3e350SEd Wildgoose	  ALIX2/3/6 boards.  However, other system specific setup should
2865d4f3e350SEd Wildgoose	  get added here.
2866d4f3e350SEd Wildgoose
2867d4f3e350SEd Wildgoose	  Note: You must still enable the drivers for GPIO and LED support
2868d4f3e350SEd Wildgoose	  (GPIO_CS5535 & LEDS_GPIO) to actually use the LEDs
2869d4f3e350SEd Wildgoose
2870d4f3e350SEd Wildgoose	  Note: You have to set alix.force=1 for boards with Award BIOS.
2871d4f3e350SEd Wildgoose
2872da4e3302SPhilip Prindevilleconfig NET5501
2873da4e3302SPhilip Prindeville	bool "Soekris Engineering net5501 System Support (LEDS, GPIO, etc)"
2874da4e3302SPhilip Prindeville	select GPIOLIB
2875a7f7f624SMasahiro Yamada	help
2876da4e3302SPhilip Prindeville	  This option enables system support for the Soekris Engineering net5501.
2877da4e3302SPhilip Prindeville
28783197059aSPhilip A. Prindevilleconfig GEOS
28793197059aSPhilip A. Prindeville	bool "Traverse Technologies GEOS System Support (LEDS, GPIO, etc)"
28803197059aSPhilip A. Prindeville	select GPIOLIB
28813197059aSPhilip A. Prindeville	depends on DMI
2882a7f7f624SMasahiro Yamada	help
28833197059aSPhilip A. Prindeville	  This option enables system support for the Traverse Technologies GEOS.
28843197059aSPhilip A. Prindeville
28857d029125SVivien Didelotconfig TS5500
28867d029125SVivien Didelot	bool "Technologic Systems TS-5500 platform support"
28877d029125SVivien Didelot	depends on MELAN
28887d029125SVivien Didelot	select CHECK_SIGNATURE
28897d029125SVivien Didelot	select NEW_LEDS
28907d029125SVivien Didelot	select LEDS_CLASS
2891a7f7f624SMasahiro Yamada	help
28927d029125SVivien Didelot	  This option enables system support for the Technologic Systems TS-5500.
28937d029125SVivien Didelot
2894e279b6c1SSam Ravnborgendif # X86_32
2895e279b6c1SSam Ravnborg
289623ac4ae8SAndreas Herrmannconfig AMD_NB
2897e279b6c1SSam Ravnborg	def_bool y
28980e152cd7SBorislav Petkov	depends on CPU_SUP_AMD && PCI
2899e279b6c1SSam Ravnborg
2900e279b6c1SSam Ravnborgendmenu
2901e279b6c1SSam Ravnborg
29021572497cSChristoph Hellwigmenu "Binary Emulations"
2903e279b6c1SSam Ravnborg
2904e279b6c1SSam Ravnborgconfig IA32_EMULATION
2905e279b6c1SSam Ravnborg	bool "IA32 Emulation"
2906e279b6c1SSam Ravnborg	depends on X86_64
290739f88911SIngo Molnar	select ARCH_WANT_OLD_COMPAT_IPC
2908d1603990SRandy Dunlap	select BINFMT_ELF
290939f88911SIngo Molnar	select COMPAT_OLD_SIGACTION
2910a7f7f624SMasahiro Yamada	help
29115fd92e65SH. J. Lu	  Include code to run legacy 32-bit programs under a
29125fd92e65SH. J. Lu	  64-bit kernel. You should likely turn this on, unless you're
29135fd92e65SH. J. Lu	  100% sure that you don't have any 32-bit programs left.
2914e279b6c1SSam Ravnborg
291583a44a4fSMasahiro Yamadaconfig X86_X32_ABI
29166ea30386SKees Cook	bool "x32 ABI for 64-bit mode"
29179b54050bSBrian Gerst	depends on X86_64
2918aaeed6ecSNathan Chancellor	# llvm-objcopy does not convert x86_64 .note.gnu.property or
2919aaeed6ecSNathan Chancellor	# compressed debug sections to x86_x32 properly:
2920aaeed6ecSNathan Chancellor	# https://github.com/ClangBuiltLinux/linux/issues/514
2921aaeed6ecSNathan Chancellor	# https://github.com/ClangBuiltLinux/linux/issues/1141
2922aaeed6ecSNathan Chancellor	depends on $(success,$(OBJCOPY) --version | head -n1 | grep -qv llvm)
2923a7f7f624SMasahiro Yamada	help
29245fd92e65SH. J. Lu	  Include code to run binaries for the x32 native 32-bit ABI
29255fd92e65SH. J. Lu	  for 64-bit processors.  An x32 process gets access to the
29265fd92e65SH. J. Lu	  full 64-bit register file and wide data path while leaving
29275fd92e65SH. J. Lu	  pointers at 32 bits for smaller memory footprint.
29285fd92e65SH. J. Lu
2929953fee1dSIngo Molnarconfig COMPAT_32
2930953fee1dSIngo Molnar	def_bool y
2931953fee1dSIngo Molnar	depends on IA32_EMULATION || X86_32
2932953fee1dSIngo Molnar	select HAVE_UID16
2933953fee1dSIngo Molnar	select OLD_SIGSUSPEND3
2934953fee1dSIngo Molnar
2935e279b6c1SSam Ravnborgconfig COMPAT
29363c2362e6SHarvey Harrison	def_bool y
293783a44a4fSMasahiro Yamada	depends on IA32_EMULATION || X86_X32_ABI
2938e279b6c1SSam Ravnborg
2939e279b6c1SSam Ravnborgconfig COMPAT_FOR_U64_ALIGNMENT
29403120e25eSJan Beulich	def_bool y
2941a9251280SLinus Torvalds	depends on COMPAT
2942ee009e4aSDavid Howells
2943e279b6c1SSam Ravnborgendmenu
2944e279b6c1SSam Ravnborg
2945e5beae16SKeith Packardconfig HAVE_ATOMIC_IOMAP
2946e5beae16SKeith Packard	def_bool y
2947e5beae16SKeith Packard	depends on X86_32
2948e5beae16SKeith Packard
2949edf88417SAvi Kivitysource "arch/x86/kvm/Kconfig"
29505e8ebd84SJason A. Donenfeld
29515e8ebd84SJason A. Donenfeldsource "arch/x86/Kconfig.assembler"
2952