xref: /linux/arch/x86/Kconfig (revision 4ca8cc8d1bbe582bfc7a4d80bd72cfd8d3d0e2e8)
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
111583bfd48SNathan Chancellor	select ARCH_SUPPORTS_LTO_CLANG
112583bfd48SNathan Chancellor	select ARCH_SUPPORTS_LTO_CLANG_THIN
1136471b825SIngo Molnar	select ARCH_USE_BUILTIN_BSWAP
114dce44566SAnshuman Khandual	select ARCH_USE_MEMTEST
1156471b825SIngo Molnar	select ARCH_USE_QUEUED_RWLOCKS
1166471b825SIngo Molnar	select ARCH_USE_QUEUED_SPINLOCKS
1172ce0d7f9SMark Brown	select ARCH_USE_SYM_ANNOTATIONS
118ce4a4e56SAndy Lutomirski	select ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH
11981c22041SDaniel Borkmann	select ARCH_WANT_DEFAULT_BPF_JIT	if X86_64
120c763ea26SIngo Molnar	select ARCH_WANTS_DYNAMIC_TASK_STRUCT
12151c2ee6dSNick Desaulniers	select ARCH_WANTS_NO_INSTR
12207431506SAnshuman Khandual	select ARCH_WANT_GENERAL_HUGETLB
1233876d4a3SAlexandre Ghiti	select ARCH_WANT_HUGE_PMD_SHARE
12447010c04SMuchun Song	select ARCH_WANT_HUGETLB_PAGE_OPTIMIZE_VMEMMAP	if X86_64
12559612b24SNathan Chancellor	select ARCH_WANT_LD_ORPHAN_WARN
12638d8b4e6SHuang Ying	select ARCH_WANTS_THP_SWAP		if X86_64
127b5f06f64SBalbir Singh	select ARCH_HAS_PARANOID_L1D_FLUSH
12810916706SShile Zhang	select BUILDTIME_TABLE_SORT
1296471b825SIngo Molnar	select CLKEVT_I8253
1306471b825SIngo Molnar	select CLOCKSOURCE_VALIDATE_LAST_CYCLE
1316471b825SIngo Molnar	select CLOCKSOURCE_WATCHDOG
1327cf8f44aSAlexander Potapenko	# Word-size accesses may read uninitialized data past the trailing \0
1337cf8f44aSAlexander Potapenko	# in strings and cause false KMSAN reports.
1347cf8f44aSAlexander Potapenko	select DCACHE_WORD_ACCESS		if !KMSAN
1353aac3ebeSThomas Gleixner	select DYNAMIC_SIGFRAME
13645471cd9SLinus Torvalds	select EDAC_ATOMIC_SCRUB
13745471cd9SLinus Torvalds	select EDAC_SUPPORT
1386471b825SIngo Molnar	select GENERIC_CLOCKEVENTS_BROADCAST	if X86_64 || (X86_32 && X86_LOCAL_APIC)
1396471b825SIngo Molnar	select GENERIC_CLOCKEVENTS_MIN_ADJUST
1406471b825SIngo Molnar	select GENERIC_CMOS_UPDATE
1416471b825SIngo Molnar	select GENERIC_CPU_AUTOPROBE
14261dc0f55SThomas Gleixner	select GENERIC_CPU_VULNERABILITIES
1436471b825SIngo Molnar	select GENERIC_EARLY_IOREMAP
14427d6b4d1SThomas Gleixner	select GENERIC_ENTRY
1456471b825SIngo Molnar	select GENERIC_IOMAP
146c7d6c9ddSThomas Gleixner	select GENERIC_IRQ_EFFECTIVE_AFF_MASK	if SMP
1470fa115daSThomas Gleixner	select GENERIC_IRQ_MATRIX_ALLOCATOR	if X86_LOCAL_APIC
148ad7a929fSThomas Gleixner	select GENERIC_IRQ_MIGRATION		if SMP
1496471b825SIngo Molnar	select GENERIC_IRQ_PROBE
150c201c917SThomas Gleixner	select GENERIC_IRQ_RESERVATION_MODE
1516471b825SIngo Molnar	select GENERIC_IRQ_SHOW
1526471b825SIngo Molnar	select GENERIC_PENDING_IRQ		if SMP
1532ae27137SSteven Price	select GENERIC_PTDUMP
1546471b825SIngo Molnar	select GENERIC_SMP_IDLE_THREAD
1556471b825SIngo Molnar	select GENERIC_TIME_VSYSCALL
1567ac87074SVincenzo Frascino	select GENERIC_GETTIMEOFDAY
157550a77a7SDmitry Safonov	select GENERIC_VDSO_TIME_NS
15839656e83SChristoph Hellwig	select GUP_GET_PTE_LOW_HIGH		if X86_PAE
15917e5888eSHans de Goede	select HARDIRQS_SW_RESEND
1607edaeb68SThomas Gleixner	select HARDLOCKUP_CHECK_TIMESTAMP	if X86_64
1616471b825SIngo Molnar	select HAVE_ACPI_APEI			if ACPI
1626471b825SIngo Molnar	select HAVE_ACPI_APEI_NMI		if ACPI
1636471b825SIngo Molnar	select HAVE_ALIGNED_STRUCT_PAGE		if SLUB
1646471b825SIngo Molnar	select HAVE_ARCH_AUDITSYSCALL
1656471b825SIngo Molnar	select HAVE_ARCH_HUGE_VMAP		if X86_64 || X86_PAE
166eed1fceeSSong Liu	select HAVE_ARCH_HUGE_VMALLOC		if X86_64
1676471b825SIngo Molnar	select HAVE_ARCH_JUMP_LABEL
168b34006c4SArd Biesheuvel	select HAVE_ARCH_JUMP_LABEL_RELATIVE
169d17a1d97SAndrey Ryabinin	select HAVE_ARCH_KASAN			if X86_64
1700609ae01SDaniel Axtens	select HAVE_ARCH_KASAN_VMALLOC		if X86_64
1711dc0da6eSAlexander Potapenko	select HAVE_ARCH_KFENCE
172*4ca8cc8dSAlexander Potapenko	select HAVE_ARCH_KMSAN			if X86_64
1736471b825SIngo Molnar	select HAVE_ARCH_KGDB
1749e08f57dSDaniel Cashman	select HAVE_ARCH_MMAP_RND_BITS		if MMU
1759e08f57dSDaniel Cashman	select HAVE_ARCH_MMAP_RND_COMPAT_BITS	if MMU && COMPAT
1761b028f78SDmitry Safonov	select HAVE_ARCH_COMPAT_MMAP_BASES	if MMU && COMPAT
177271ca788SArd Biesheuvel	select HAVE_ARCH_PREL32_RELOCATIONS
1786471b825SIngo Molnar	select HAVE_ARCH_SECCOMP_FILTER
179f7d83c1cSKees Cook	select HAVE_ARCH_THREAD_STRUCT_WHITELIST
180afaef01cSAlexander Popov	select HAVE_ARCH_STACKLEAK
1816471b825SIngo Molnar	select HAVE_ARCH_TRACEHOOK
1826471b825SIngo Molnar	select HAVE_ARCH_TRANSPARENT_HUGEPAGE
183a00cc7d9SMatthew Wilcox	select HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD if X86_64
184b64d8d1eSPeter Xu	select HAVE_ARCH_USERFAULTFD_WP         if X86_64 && USERFAULTFD
1857677f7fdSAxel Rasmussen	select HAVE_ARCH_USERFAULTFD_MINOR	if X86_64 && USERFAULTFD
186e37e43a4SAndy Lutomirski	select HAVE_ARCH_VMAP_STACK		if X86_64
187fe950f60SKees Cook	select HAVE_ARCH_RANDOMIZE_KSTACK_OFFSET
188c763ea26SIngo Molnar	select HAVE_ARCH_WITHIN_STACK_FRAMES
1892ff2b7ecSMasahiro Yamada	select HAVE_ASM_MODVERSIONS
1906471b825SIngo Molnar	select HAVE_CMPXCHG_DOUBLE
1916471b825SIngo Molnar	select HAVE_CMPXCHG_LOCAL
19224a9c541SFrederic Weisbecker	select HAVE_CONTEXT_TRACKING_USER		if X86_64
19324a9c541SFrederic Weisbecker	select HAVE_CONTEXT_TRACKING_USER_OFFSTACK	if HAVE_CONTEXT_TRACKING_USER
1946471b825SIngo Molnar	select HAVE_C_RECORDMCOUNT
19503f16cd0SJosh Poimboeuf	select HAVE_OBJTOOL_MCOUNT		if HAVE_OBJTOOL
1964ed308c4SSteven Rostedt (Google)	select HAVE_BUILDTIME_MCOUNT_SORT
1976471b825SIngo Molnar	select HAVE_DEBUG_KMEMLEAK
1989c5a3621SAkinobu Mita	select HAVE_DMA_CONTIGUOUS
199677aa9f7SSteven Rostedt	select HAVE_DYNAMIC_FTRACE
20006aeaaeaSMasami Hiramatsu	select HAVE_DYNAMIC_FTRACE_WITH_REGS
20102a474caSSteven Rostedt (VMware)	select HAVE_DYNAMIC_FTRACE_WITH_ARGS	if X86_64
202562955feSSteven Rostedt (VMware)	select HAVE_DYNAMIC_FTRACE_WITH_DIRECT_CALLS
203c316eb44SHeiko Carstens	select HAVE_SAMPLE_FTRACE_DIRECT	if X86_64
204503e4510SHeiko Carstens	select HAVE_SAMPLE_FTRACE_DIRECT_MULTI	if X86_64
20503f5781bSWang YanQing	select HAVE_EBPF_JIT
20658340a07SJohannes Berg	select HAVE_EFFICIENT_UNALIGNED_ACCESS
2076630a8e5SChristoph Hellwig	select HAVE_EISA
2085f56a5dfSJiri Slaby	select HAVE_EXIT_THREAD
20967a929e0SChristoph Hellwig	select HAVE_FAST_GUP
210644e0e8dSSteven Rostedt (VMware)	select HAVE_FENTRY			if X86_64 || DYNAMIC_FTRACE
2116471b825SIngo Molnar	select HAVE_FTRACE_MCOUNT_RECORD
2124a30e4c9SSteven Rostedt (VMware)	select HAVE_FUNCTION_GRAPH_TRACER	if X86_32 || (X86_64 && DYNAMIC_FTRACE)
2136471b825SIngo Molnar	select HAVE_FUNCTION_TRACER
2146b90bd4bSEmese Revfy	select HAVE_GCC_PLUGINS
2150067f129SK.Prasad	select HAVE_HW_BREAKPOINT
2166471b825SIngo Molnar	select HAVE_IOREMAP_PROT
217624db9eaSThomas Gleixner	select HAVE_IRQ_EXIT_ON_IRQ_STACK	if X86_64
2186471b825SIngo Molnar	select HAVE_IRQ_TIME_ACCOUNTING
2194ab7674fSJosh Poimboeuf	select HAVE_JUMP_LABEL_HACK		if HAVE_OBJTOOL
2206471b825SIngo Molnar	select HAVE_KERNEL_BZIP2
2216471b825SIngo Molnar	select HAVE_KERNEL_GZIP
2226471b825SIngo Molnar	select HAVE_KERNEL_LZ4
2236471b825SIngo Molnar	select HAVE_KERNEL_LZMA
2246471b825SIngo Molnar	select HAVE_KERNEL_LZO
2256471b825SIngo Molnar	select HAVE_KERNEL_XZ
226fb46d057SNick Terrell	select HAVE_KERNEL_ZSTD
2276471b825SIngo Molnar	select HAVE_KPROBES
2286471b825SIngo Molnar	select HAVE_KPROBES_ON_FTRACE
229540adea3SMasami Hiramatsu	select HAVE_FUNCTION_ERROR_INJECTION
2306471b825SIngo Molnar	select HAVE_KRETPROBES
231f3a112c0SMasami Hiramatsu	select HAVE_RETHOOK
2326471b825SIngo Molnar	select HAVE_KVM
2336471b825SIngo Molnar	select HAVE_LIVEPATCH			if X86_64
2340102752eSFrederic Weisbecker	select HAVE_MIXED_BREAKPOINTS_REGS
235ee9f8fceSJosh Poimboeuf	select HAVE_MOD_ARCH_SPECIFIC
2369f132f7eSJoel Fernandes (Google)	select HAVE_MOVE_PMD
237be37c98dSKalesh Singh	select HAVE_MOVE_PUD
23822102f45SJosh Poimboeuf	select HAVE_NOINSTR_HACK		if HAVE_OBJTOOL
23942a0bb3fSPetr Mladek	select HAVE_NMI
240489e355bSJosh Poimboeuf	select HAVE_NOINSTR_VALIDATION		if HAVE_OBJTOOL
24103f16cd0SJosh Poimboeuf	select HAVE_OBJTOOL			if X86_64
2426471b825SIngo Molnar	select HAVE_OPTPROBES
2436471b825SIngo Molnar	select HAVE_PCSPKR_PLATFORM
2446471b825SIngo Molnar	select HAVE_PERF_EVENTS
245c01d4323SFrederic Weisbecker	select HAVE_PERF_EVENTS_NMI
24692e5aae4SNicholas Piggin	select HAVE_HARDLOCKUP_DETECTOR_PERF	if PERF_EVENTS && HAVE_PERF_EVENTS_NMI
247eb01d42aSChristoph Hellwig	select HAVE_PCI
248c5e63197SJiri Olsa	select HAVE_PERF_REGS
249c5ebcedbSJiri Olsa	select HAVE_PERF_USER_STACK_DUMP
250ff2e6d72SPeter Zijlstra	select MMU_GATHER_RCU_TABLE_FREE	if PARAVIRT
2511e9fdf21SPeter Zijlstra	select MMU_GATHER_MERGE_VMAS
25200998085SThomas Gleixner	select HAVE_POSIX_CPU_TIMERS_TASK_WORK
2536471b825SIngo Molnar	select HAVE_REGS_AND_STACK_ACCESS_API
25403f16cd0SJosh Poimboeuf	select HAVE_RELIABLE_STACKTRACE		if UNWINDER_ORC || STACK_VALIDATION
2553c88ee19SMasami Hiramatsu	select HAVE_FUNCTION_ARG_ACCESS_API
2567ecd19cfSKefeng Wang	select HAVE_SETUP_PER_CPU_AREA
257cd1a41ceSThomas Gleixner	select HAVE_SOFTIRQ_ON_OWN_STACK
258d148eac0SMasahiro Yamada	select HAVE_STACKPROTECTOR		if CC_HAS_SANE_STACKPROTECTOR
25903f16cd0SJosh Poimboeuf	select HAVE_STACK_VALIDATION		if HAVE_OBJTOOL
260e6d6c071SJosh Poimboeuf	select HAVE_STATIC_CALL
26103f16cd0SJosh Poimboeuf	select HAVE_STATIC_CALL_INLINE		if HAVE_OBJTOOL
26299cf983cSMark Rutland	select HAVE_PREEMPT_DYNAMIC_CALL
263d6761b8fSMathieu Desnoyers	select HAVE_RSEQ
2646471b825SIngo Molnar	select HAVE_SYSCALL_TRACEPOINTS
2655f3da8c0SJosh Poimboeuf	select HAVE_UACCESS_VALIDATION		if HAVE_OBJTOOL
2666471b825SIngo Molnar	select HAVE_UNSTABLE_SCHED_CLOCK
2677c68af6eSAvi Kivity	select HAVE_USER_RETURN_NOTIFIER
2687ac87074SVincenzo Frascino	select HAVE_GENERIC_VDSO
26905736e4aSThomas Gleixner	select HOTPLUG_SMT			if SMP
270c0185808SThomas Gleixner	select IRQ_FORCED_THREADING
2717ecd19cfSKefeng Wang	select NEED_PER_CPU_EMBED_FIRST_CHUNK
2727ecd19cfSKefeng Wang	select NEED_PER_CPU_PAGE_FIRST_CHUNK
27386596f0aSChristoph Hellwig	select NEED_SG_DMA_LENGTH
2742eac9c2dSChristoph Hellwig	select PCI_DOMAINS			if PCI
275625210cfSSinan Kaya	select PCI_LOCKLESS_CONFIG		if PCI
2766471b825SIngo Molnar	select PERF_EVENTS
2773195ef59SPrarit Bhargava	select RTC_LIB
278d6faca40SArnd Bergmann	select RTC_MC146818_LIB
2796471b825SIngo Molnar	select SPARSE_IRQ
28083fe27eaSPranith Kumar	select SRCU
2816471b825SIngo Molnar	select SYSCTL_EXCEPTION_TRACE
28215f4eae7SAndy Lutomirski	select THREAD_INFO_IN_TASK
2834aae683fSMasahiro Yamada	select TRACE_IRQFLAGS_SUPPORT
2844510bffbSMark Rutland	select TRACE_IRQFLAGS_NMI_SUPPORT
2856471b825SIngo Molnar	select USER_STACKTRACE_SUPPORT
2863b02a051SIngo Molnar	select HAVE_ARCH_KCSAN			if X86_64
2876471b825SIngo Molnar	select X86_FEATURE_NAMES		if PROC_FS
2880c608dadSAubrey Li	select PROC_PID_ARCH_STATUS		if PROC_FS
28950468e43SJarkko Sakkinen	select HAVE_ARCH_NODE_DEV_GROUP		if X86_SGX
2909e2b4be3SNayna Jain	imply IMA_SECURE_AND_OR_TRUSTED_BOOT    if EFI
2917d8330a5SBalbir Singh
292ba7e4d13SIngo Molnarconfig INSTRUCTION_DECODER
2933120e25eSJan Beulich	def_bool y
2943120e25eSJan Beulich	depends on KPROBES || PERF_EVENTS || UPROBES
295ba7e4d13SIngo Molnar
29651b26adaSLinus Torvaldsconfig OUTPUT_FORMAT
29751b26adaSLinus Torvalds	string
29851b26adaSLinus Torvalds	default "elf32-i386" if X86_32
29951b26adaSLinus Torvalds	default "elf64-x86-64" if X86_64
30051b26adaSLinus Torvalds
3018d5fffb9SSam Ravnborgconfig LOCKDEP_SUPPORT
3023c2362e6SHarvey Harrison	def_bool y
3038d5fffb9SSam Ravnborg
3048d5fffb9SSam Ravnborgconfig STACKTRACE_SUPPORT
3053c2362e6SHarvey Harrison	def_bool y
3068d5fffb9SSam Ravnborg
3078d5fffb9SSam Ravnborgconfig MMU
3083c2362e6SHarvey Harrison	def_bool y
3098d5fffb9SSam Ravnborg
3109e08f57dSDaniel Cashmanconfig ARCH_MMAP_RND_BITS_MIN
3119e08f57dSDaniel Cashman	default 28 if 64BIT
3129e08f57dSDaniel Cashman	default 8
3139e08f57dSDaniel Cashman
3149e08f57dSDaniel Cashmanconfig ARCH_MMAP_RND_BITS_MAX
3159e08f57dSDaniel Cashman	default 32 if 64BIT
3169e08f57dSDaniel Cashman	default 16
3179e08f57dSDaniel Cashman
3189e08f57dSDaniel Cashmanconfig ARCH_MMAP_RND_COMPAT_BITS_MIN
3199e08f57dSDaniel Cashman	default 8
3209e08f57dSDaniel Cashman
3219e08f57dSDaniel Cashmanconfig ARCH_MMAP_RND_COMPAT_BITS_MAX
3229e08f57dSDaniel Cashman	default 16
3239e08f57dSDaniel Cashman
3248d5fffb9SSam Ravnborgconfig SBUS
3258d5fffb9SSam Ravnborg	bool
3268d5fffb9SSam Ravnborg
3278d5fffb9SSam Ravnborgconfig GENERIC_ISA_DMA
3283120e25eSJan Beulich	def_bool y
3293120e25eSJan Beulich	depends on ISA_DMA_API
3308d5fffb9SSam Ravnborg
331d911c67eSAlexander Potapenkoconfig GENERIC_CSUM
332d911c67eSAlexander Potapenko	bool
333d911c67eSAlexander Potapenko	default y if KMSAN || KASAN
334d911c67eSAlexander Potapenko
3358d5fffb9SSam Ravnborgconfig GENERIC_BUG
3363c2362e6SHarvey Harrison	def_bool y
3378d5fffb9SSam Ravnborg	depends on BUG
338b93a531eSJan Beulich	select GENERIC_BUG_RELATIVE_POINTERS if X86_64
339b93a531eSJan Beulich
340b93a531eSJan Beulichconfig GENERIC_BUG_RELATIVE_POINTERS
341b93a531eSJan Beulich	bool
3428d5fffb9SSam Ravnborg
3438d5fffb9SSam Ravnborgconfig ARCH_MAY_HAVE_PC_FDC
3443120e25eSJan Beulich	def_bool y
3453120e25eSJan Beulich	depends on ISA_DMA_API
3468d5fffb9SSam Ravnborg
3471032c0baSSam Ravnborgconfig GENERIC_CALIBRATE_DELAY
3481032c0baSSam Ravnborg	def_bool y
3491032c0baSSam Ravnborg
3509a0b8415Svenkatesh.pallipadi@intel.comconfig ARCH_HAS_CPU_RELAX
3519a0b8415Svenkatesh.pallipadi@intel.com	def_bool y
3528d5fffb9SSam Ravnborg
353801e4062SJohannes Bergconfig ARCH_HIBERNATION_POSSIBLE
354801e4062SJohannes Berg	def_bool y
355801e4062SJohannes Berg
356d7109fe3SAndy Shevchenkoconfig ARCH_NR_GPIO
357d7109fe3SAndy Shevchenko	int
358d7109fe3SAndy Shevchenko	default 1024 if X86_64
359d7109fe3SAndy Shevchenko	default 512
360d7109fe3SAndy Shevchenko
361f4cb5700SJohannes Bergconfig ARCH_SUSPEND_POSSIBLE
362f4cb5700SJohannes Berg	def_bool y
363f4cb5700SJohannes Berg
3648d5fffb9SSam Ravnborgconfig AUDIT_ARCH
365e0fd24a3SJan Beulich	def_bool y if X86_64
3668d5fffb9SSam Ravnborg
367d6f2d75aSAndrey Ryabininconfig KASAN_SHADOW_OFFSET
368d6f2d75aSAndrey Ryabinin	hex
369d6f2d75aSAndrey Ryabinin	depends on KASAN
370d6f2d75aSAndrey Ryabinin	default 0xdffffc0000000000
371d6f2d75aSAndrey Ryabinin
37269575d38SShane Wangconfig HAVE_INTEL_TXT
37369575d38SShane Wang	def_bool y
3746ea30386SKees Cook	depends on INTEL_IOMMU && ACPI
37569575d38SShane Wang
3766b0c3d44SSam Ravnborgconfig X86_32_SMP
3776b0c3d44SSam Ravnborg	def_bool y
3786b0c3d44SSam Ravnborg	depends on X86_32 && SMP
3796b0c3d44SSam Ravnborg
3806b0c3d44SSam Ravnborgconfig X86_64_SMP
3816b0c3d44SSam Ravnborg	def_bool y
3826b0c3d44SSam Ravnborg	depends on X86_64 && SMP
3836b0c3d44SSam Ravnborg
3842b144498SSrikar Dronamrajuconfig ARCH_SUPPORTS_UPROBES
3852b144498SSrikar Dronamraju	def_bool y
3862b144498SSrikar Dronamraju
387d20642f0SRob Herringconfig FIX_EARLYCON_MEM
388d20642f0SRob Herring	def_bool y
389d20642f0SRob Herring
39094d49eb3SKirill A. Shutemovconfig DYNAMIC_PHYSICAL_MASK
39194d49eb3SKirill A. Shutemov	bool
39294d49eb3SKirill A. Shutemov
39398233368SKirill A. Shutemovconfig PGTABLE_LEVELS
39498233368SKirill A. Shutemov	int
39577ef56e4SKirill A. Shutemov	default 5 if X86_5LEVEL
39698233368SKirill A. Shutemov	default 4 if X86_64
39798233368SKirill A. Shutemov	default 3 if X86_PAE
39898233368SKirill A. Shutemov	default 2
39998233368SKirill A. Shutemov
4002a61f474SMasahiro Yamadaconfig CC_HAS_SANE_STACKPROTECTOR
4012a61f474SMasahiro Yamada	bool
4021b866781SNathan Chancellor	default $(success,$(srctree)/scripts/gcc-x86_64-has-stack-protector.sh $(CC) $(CLANG_FLAGS)) if 64BIT
4031b866781SNathan Chancellor	default $(success,$(srctree)/scripts/gcc-x86_32-has-stack-protector.sh $(CC) $(CLANG_FLAGS))
4042a61f474SMasahiro Yamada	help
4052a61f474SMasahiro Yamada	  We have to make sure stack protector is unconditionally disabled if
4063fb0fdb3SAndy Lutomirski	  the compiler produces broken code or if it does not let us control
4073fb0fdb3SAndy Lutomirski	  the segment on 32-bit kernels.
4082a61f474SMasahiro Yamada
409506f1d07SSam Ravnborgmenu "Processor type and features"
410506f1d07SSam Ravnborg
411506f1d07SSam Ravnborgconfig SMP
412506f1d07SSam Ravnborg	bool "Symmetric multi-processing support"
413a7f7f624SMasahiro Yamada	help
414506f1d07SSam Ravnborg	  This enables support for systems with more than one CPU. If you have
4154a474157SRobert Graffham	  a system with only one CPU, say N. If you have a system with more
4164a474157SRobert Graffham	  than one CPU, say Y.
417506f1d07SSam Ravnborg
4184a474157SRobert Graffham	  If you say N here, the kernel will run on uni- and multiprocessor
419506f1d07SSam Ravnborg	  machines, but will use only one CPU of a multiprocessor machine. If
420506f1d07SSam Ravnborg	  you say Y here, the kernel will run on many, but not all,
4214a474157SRobert Graffham	  uniprocessor machines. On a uniprocessor machine, the kernel
422506f1d07SSam Ravnborg	  will run faster if you say N here.
423506f1d07SSam Ravnborg
424506f1d07SSam Ravnborg	  Note that if you say Y here and choose architecture "586" or
425506f1d07SSam Ravnborg	  "Pentium" under "Processor family", the kernel will not work on 486
426506f1d07SSam Ravnborg	  architectures. Similarly, multiprocessor kernels for the "PPro"
427506f1d07SSam Ravnborg	  architecture may not work on all Pentium based boards.
428506f1d07SSam Ravnborg
429506f1d07SSam Ravnborg	  People using multiprocessor machines who say Y here should also say
430506f1d07SSam Ravnborg	  Y to "Enhanced Real Time Clock Support", below. The "Advanced Power
431506f1d07SSam Ravnborg	  Management" code will be disabled if you say Y here.
432506f1d07SSam Ravnborg
433cb1aaebeSMauro Carvalho Chehab	  See also <file:Documentation/x86/i386/IO-APIC.rst>,
4344f4cfa6cSMauro Carvalho Chehab	  <file:Documentation/admin-guide/lockup-watchdogs.rst> and the SMP-HOWTO available at
435506f1d07SSam Ravnborg	  <http://www.tldp.org/docs.html#howto>.
436506f1d07SSam Ravnborg
437506f1d07SSam Ravnborg	  If you don't know what to do here, say N.
438506f1d07SSam Ravnborg
4399def39beSJosh Triplettconfig X86_FEATURE_NAMES
4409def39beSJosh Triplett	bool "Processor feature human-readable names" if EMBEDDED
4419def39beSJosh Triplett	default y
442a7f7f624SMasahiro Yamada	help
4439def39beSJosh Triplett	  This option compiles in a table of x86 feature bits and corresponding
4449def39beSJosh Triplett	  names.  This is required to support /proc/cpuinfo and a few kernel
4459def39beSJosh Triplett	  messages.  You can disable this to save space, at the expense of
4469def39beSJosh Triplett	  making those few kernel messages show numeric feature bits instead.
4479def39beSJosh Triplett
4489def39beSJosh Triplett	  If in doubt, say Y.
4499def39beSJosh Triplett
45006cd9a7dSYinghai Luconfig X86_X2APIC
45106cd9a7dSYinghai Lu	bool "Support x2apic"
45219e3d60dSJan Kiszka	depends on X86_LOCAL_APIC && X86_64 && (IRQ_REMAP || HYPERVISOR_GUEST)
453a7f7f624SMasahiro Yamada	help
45406cd9a7dSYinghai Lu	  This enables x2apic support on CPUs that have this feature.
45506cd9a7dSYinghai Lu
45606cd9a7dSYinghai Lu	  This allows 32-bit apic IDs (so it can support very large systems),
45706cd9a7dSYinghai Lu	  and accesses the local apic via MSRs not via mmio.
45806cd9a7dSYinghai Lu
45906cd9a7dSYinghai Lu	  If you don't know what to do here, say N.
46006cd9a7dSYinghai Lu
4616695c85bSYinghai Luconfig X86_MPPARSE
4624590d98fSAndy Shevchenko	bool "Enable MPS table" if ACPI
4637a527688SJan Beulich	default y
4645ab74722SIngo Molnar	depends on X86_LOCAL_APIC
465a7f7f624SMasahiro Yamada	help
4666695c85bSYinghai Lu	  For old smp systems that do not have proper acpi support. Newer systems
4676695c85bSYinghai Lu	  (esp with 64bit cpus) with acpi support, MADT and DSDT will override it
4686695c85bSYinghai Lu
469ddd70cf9SJun Nakajimaconfig GOLDFISH
470ddd70cf9SJun Nakajima	def_bool y
471ddd70cf9SJun Nakajima	depends on X86_GOLDFISH
472ddd70cf9SJun Nakajima
473e6d42931SJohannes Weinerconfig X86_CPU_RESCTRL
474e6d42931SJohannes Weiner	bool "x86 CPU resource control support"
4756fe07ce3SBabu Moger	depends on X86 && (CPU_SUP_INTEL || CPU_SUP_AMD)
47659fe5a77SThomas Gleixner	select KERNFS
477e79f15a4SChen Yu	select PROC_CPU_RESCTRL		if PROC_FS
47878e99b4aSFenghua Yu	help
479e6d42931SJohannes Weiner	  Enable x86 CPU resource control support.
4806fe07ce3SBabu Moger
4816fe07ce3SBabu Moger	  Provide support for the allocation and monitoring of system resources
4826fe07ce3SBabu Moger	  usage by the CPU.
4836fe07ce3SBabu Moger
4846fe07ce3SBabu Moger	  Intel calls this Intel Resource Director Technology
4856fe07ce3SBabu Moger	  (Intel(R) RDT). More information about RDT can be found in the
4866fe07ce3SBabu Moger	  Intel x86 Architecture Software Developer Manual.
4876fe07ce3SBabu Moger
4886fe07ce3SBabu Moger	  AMD calls this AMD Platform Quality of Service (AMD QoS).
4896fe07ce3SBabu Moger	  More information about AMD QoS can be found in the AMD64 Technology
4906fe07ce3SBabu Moger	  Platform Quality of Service Extensions manual.
49178e99b4aSFenghua Yu
49278e99b4aSFenghua Yu	  Say N if unsure.
49378e99b4aSFenghua Yu
4948425091fSRavikiran G Thirumalaiif X86_32
495a0d0bb4dSRandy Dunlapconfig X86_BIGSMP
496a0d0bb4dSRandy Dunlap	bool "Support for big SMP systems with more than 8 CPUs"
497a0d0bb4dSRandy Dunlap	depends on SMP
498a7f7f624SMasahiro Yamada	help
499e133f6eaSRandy Dunlap	  This option is needed for the systems that have more than 8 CPUs.
500a0d0bb4dSRandy Dunlap
501c5c606d9SRavikiran G Thirumalaiconfig X86_EXTENDED_PLATFORM
502c5c606d9SRavikiran G Thirumalai	bool "Support for extended (non-PC) x86 platforms"
503c5c606d9SRavikiran G Thirumalai	default y
504a7f7f624SMasahiro Yamada	help
50506ac8346SIngo Molnar	  If you disable this option then the kernel will only support
50606ac8346SIngo Molnar	  standard PC platforms. (which covers the vast majority of
50706ac8346SIngo Molnar	  systems out there.)
50806ac8346SIngo Molnar
5098425091fSRavikiran G Thirumalai	  If you enable this option then you'll be able to select support
5108425091fSRavikiran G Thirumalai	  for the following (non-PC) 32 bit x86 platforms:
511cb7b8023SBen Hutchings		Goldfish (Android emulator)
5128425091fSRavikiran G Thirumalai		AMD Elan
5138425091fSRavikiran G Thirumalai		RDC R-321x SoC
5148425091fSRavikiran G Thirumalai		SGI 320/540 (Visual Workstation)
51583125a3aSAlessandro Rubini		STA2X11-based (e.g. Northville)
5163f4110a4SThomas Gleixner		Moorestown MID devices
51706ac8346SIngo Molnar
51806ac8346SIngo Molnar	  If you have one of these systems, or if you want to build a
51906ac8346SIngo Molnar	  generic distribution kernel, say Y here - otherwise say N.
520758cd94aSJuerg Haefligerendif # X86_32
52106ac8346SIngo Molnar
5228425091fSRavikiran G Thirumalaiif X86_64
5238425091fSRavikiran G Thirumalaiconfig X86_EXTENDED_PLATFORM
5248425091fSRavikiran G Thirumalai	bool "Support for extended (non-PC) x86 platforms"
5258425091fSRavikiran G Thirumalai	default y
526a7f7f624SMasahiro Yamada	help
5278425091fSRavikiran G Thirumalai	  If you disable this option then the kernel will only support
5288425091fSRavikiran G Thirumalai	  standard PC platforms. (which covers the vast majority of
5298425091fSRavikiran G Thirumalai	  systems out there.)
5308425091fSRavikiran G Thirumalai
5318425091fSRavikiran G Thirumalai	  If you enable this option then you'll be able to select support
5328425091fSRavikiran G Thirumalai	  for the following (non-PC) 64 bit x86 platforms:
53344b111b5SSteffen Persvold		Numascale NumaChip
5348425091fSRavikiran G Thirumalai		ScaleMP vSMP
5358425091fSRavikiran G Thirumalai		SGI Ultraviolet
5368425091fSRavikiran G Thirumalai
5378425091fSRavikiran G Thirumalai	  If you have one of these systems, or if you want to build a
5388425091fSRavikiran G Thirumalai	  generic distribution kernel, say Y here - otherwise say N.
539758cd94aSJuerg Haefligerendif # X86_64
540c5c606d9SRavikiran G Thirumalai# This is an alphabetically sorted list of 64 bit extended platforms
541c5c606d9SRavikiran G Thirumalai# Please maintain the alphabetic order if and when there are additions
54244b111b5SSteffen Persvoldconfig X86_NUMACHIP
54344b111b5SSteffen Persvold	bool "Numascale NumaChip"
54444b111b5SSteffen Persvold	depends on X86_64
54544b111b5SSteffen Persvold	depends on X86_EXTENDED_PLATFORM
54644b111b5SSteffen Persvold	depends on NUMA
54744b111b5SSteffen Persvold	depends on SMP
54844b111b5SSteffen Persvold	depends on X86_X2APIC
549f9726bfdSDaniel J Blueman	depends on PCI_MMCONFIG
550a7f7f624SMasahiro Yamada	help
55144b111b5SSteffen Persvold	  Adds support for Numascale NumaChip large-SMP systems. Needed to
55244b111b5SSteffen Persvold	  enable more than ~168 cores.
55344b111b5SSteffen Persvold	  If you don't have one of these, you should say N here.
55403b48632SNick Piggin
5556a48565eSIngo Molnarconfig X86_VSMP
556c5c606d9SRavikiran G Thirumalai	bool "ScaleMP vSMP"
5576276a074SBorislav Petkov	select HYPERVISOR_GUEST
5586a48565eSIngo Molnar	select PARAVIRT
5596a48565eSIngo Molnar	depends on X86_64 && PCI
560c5c606d9SRavikiran G Thirumalai	depends on X86_EXTENDED_PLATFORM
561ead91d4bSShai Fultheim	depends on SMP
562a7f7f624SMasahiro Yamada	help
5636a48565eSIngo Molnar	  Support for ScaleMP vSMP systems.  Say 'Y' here if this kernel is
5646a48565eSIngo Molnar	  supposed to run on these EM64T-based machines.  Only choose this option
5656a48565eSIngo Molnar	  if you have one of these machines.
5666a48565eSIngo Molnar
567c5c606d9SRavikiran G Thirumalaiconfig X86_UV
568c5c606d9SRavikiran G Thirumalai	bool "SGI Ultraviolet"
569c5c606d9SRavikiran G Thirumalai	depends on X86_64
570c5c606d9SRavikiran G Thirumalai	depends on X86_EXTENDED_PLATFORM
57154c28d29SJack Steiner	depends on NUMA
5721ecb4ae5SAndrew Morton	depends on EFI
573c2209ea5SIngo Molnar	depends on KEXEC_CORE
5749d6c26e7SSuresh Siddha	depends on X86_X2APIC
5751222e564SIngo Molnar	depends on PCI
576a7f7f624SMasahiro Yamada	help
577c5c606d9SRavikiran G Thirumalai	  This option is needed in order to support SGI Ultraviolet systems.
578c5c606d9SRavikiran G Thirumalai	  If you don't have one of these, you should say N here.
579c5c606d9SRavikiran G Thirumalai
580c5c606d9SRavikiran G Thirumalai# Following is an alphabetically sorted list of 32 bit extended platforms
581c5c606d9SRavikiran G Thirumalai# Please maintain the alphabetic order if and when there are additions
582506f1d07SSam Ravnborg
583ddd70cf9SJun Nakajimaconfig X86_GOLDFISH
584ddd70cf9SJun Nakajima	bool "Goldfish (Virtual Platform)"
585cb7b8023SBen Hutchings	depends on X86_EXTENDED_PLATFORM
586a7f7f624SMasahiro Yamada	help
587ddd70cf9SJun Nakajima	  Enable support for the Goldfish virtual platform used primarily
588ddd70cf9SJun Nakajima	  for Android development. Unless you are building for the Android
589ddd70cf9SJun Nakajima	  Goldfish emulator say N here.
590ddd70cf9SJun Nakajima
591c751e17bSThomas Gleixnerconfig X86_INTEL_CE
592c751e17bSThomas Gleixner	bool "CE4100 TV platform"
593c751e17bSThomas Gleixner	depends on PCI
594c751e17bSThomas Gleixner	depends on PCI_GODIRECT
5956084a6e2SJiang Liu	depends on X86_IO_APIC
596c751e17bSThomas Gleixner	depends on X86_32
597c751e17bSThomas Gleixner	depends on X86_EXTENDED_PLATFORM
59837bc9f50SDirk Brandewie	select X86_REBOOTFIXUPS
599da6b737bSSebastian Andrzej Siewior	select OF
600da6b737bSSebastian Andrzej Siewior	select OF_EARLY_FLATTREE
601a7f7f624SMasahiro Yamada	help
602c751e17bSThomas Gleixner	  Select for the Intel CE media processor (CE4100) SOC.
603c751e17bSThomas Gleixner	  This option compiles in support for the CE4100 SOC for settop
604c751e17bSThomas Gleixner	  boxes and media devices.
605c751e17bSThomas Gleixner
6064cb9b00fSDavid Cohenconfig X86_INTEL_MID
60743605ef1SAlan Cox	bool "Intel MID platform support"
60843605ef1SAlan Cox	depends on X86_EXTENDED_PLATFORM
609edc6bc78SDavid Cohen	depends on X86_PLATFORM_DEVICES
6101ea7c673SAlan Cox	depends on PCI
6113fda5bb4SAndy Shevchenko	depends on X86_64 || (PCI_GOANY && X86_32)
6121ea7c673SAlan Cox	depends on X86_IO_APIC
6134cb9b00fSDavid Cohen	select I2C
6147c9c3a1eSAlan Cox	select DW_APB_TIMER
61554b34aa0SMika Westerberg	select INTEL_SCU_PCI
616a7f7f624SMasahiro Yamada	help
6174cb9b00fSDavid Cohen	  Select to build a kernel capable of supporting Intel MID (Mobile
6184cb9b00fSDavid Cohen	  Internet Device) platform systems which do not have the PCI legacy
6194cb9b00fSDavid Cohen	  interfaces. If you are building for a PC class system say N here.
6201ea7c673SAlan Cox
6214cb9b00fSDavid Cohen	  Intel MID platforms are based on an Intel processor and chipset which
6224cb9b00fSDavid Cohen	  consume less power than most of the x86 derivatives.
62343605ef1SAlan Cox
6248bbc2a13SBryan O'Donoghueconfig X86_INTEL_QUARK
6258bbc2a13SBryan O'Donoghue	bool "Intel Quark platform support"
6268bbc2a13SBryan O'Donoghue	depends on X86_32
6278bbc2a13SBryan O'Donoghue	depends on X86_EXTENDED_PLATFORM
6288bbc2a13SBryan O'Donoghue	depends on X86_PLATFORM_DEVICES
6298bbc2a13SBryan O'Donoghue	depends on X86_TSC
6308bbc2a13SBryan O'Donoghue	depends on PCI
6318bbc2a13SBryan O'Donoghue	depends on PCI_GOANY
6328bbc2a13SBryan O'Donoghue	depends on X86_IO_APIC
6338bbc2a13SBryan O'Donoghue	select IOSF_MBI
6348bbc2a13SBryan O'Donoghue	select INTEL_IMR
6359ab6eb51SAndy Shevchenko	select COMMON_CLK
636a7f7f624SMasahiro Yamada	help
6378bbc2a13SBryan O'Donoghue	  Select to include support for Quark X1000 SoC.
6388bbc2a13SBryan O'Donoghue	  Say Y here if you have a Quark based system such as the Arduino
6398bbc2a13SBryan O'Donoghue	  compatible Intel Galileo.
6408bbc2a13SBryan O'Donoghue
6413d48aab1SMika Westerbergconfig X86_INTEL_LPSS
6423d48aab1SMika Westerberg	bool "Intel Low Power Subsystem Support"
6435962dd22SSinan Kaya	depends on X86 && ACPI && PCI
6443d48aab1SMika Westerberg	select COMMON_CLK
6450f531431SMathias Nyman	select PINCTRL
646eebb3e8dSAndy Shevchenko	select IOSF_MBI
647a7f7f624SMasahiro Yamada	help
6483d48aab1SMika Westerberg	  Select to build support for Intel Low Power Subsystem such as
6493d48aab1SMika Westerberg	  found on Intel Lynxpoint PCH. Selecting this option enables
6500f531431SMathias Nyman	  things like clock tree (common clock framework) and pincontrol
6510f531431SMathias Nyman	  which are needed by the LPSS peripheral drivers.
6523d48aab1SMika Westerberg
65392082a88SKen Xueconfig X86_AMD_PLATFORM_DEVICE
65492082a88SKen Xue	bool "AMD ACPI2Platform devices support"
65592082a88SKen Xue	depends on ACPI
65692082a88SKen Xue	select COMMON_CLK
65792082a88SKen Xue	select PINCTRL
658a7f7f624SMasahiro Yamada	help
65992082a88SKen Xue	  Select to interpret AMD specific ACPI device to platform device
66092082a88SKen Xue	  such as I2C, UART, GPIO found on AMD Carrizo and later chipsets.
66192082a88SKen Xue	  I2C and UART depend on COMMON_CLK to set clock. GPIO driver is
66292082a88SKen Xue	  implemented under PINCTRL subsystem.
66392082a88SKen Xue
664ced3ce76SDavid E. Boxconfig IOSF_MBI
665ced3ce76SDavid E. Box	tristate "Intel SoC IOSF Sideband support for SoC platforms"
666ced3ce76SDavid E. Box	depends on PCI
667a7f7f624SMasahiro Yamada	help
668ced3ce76SDavid E. Box	  This option enables sideband register access support for Intel SoC
669ced3ce76SDavid E. Box	  platforms. On these platforms the IOSF sideband is used in lieu of
670ced3ce76SDavid E. Box	  MSR's for some register accesses, mostly but not limited to thermal
671ced3ce76SDavid E. Box	  and power. Drivers may query the availability of this device to
672ced3ce76SDavid E. Box	  determine if they need the sideband in order to work on these
673ced3ce76SDavid E. Box	  platforms. The sideband is available on the following SoC products.
674ced3ce76SDavid E. Box	  This list is not meant to be exclusive.
675ced3ce76SDavid E. Box	   - BayTrail
676ced3ce76SDavid E. Box	   - Braswell
677ced3ce76SDavid E. Box	   - Quark
678ced3ce76SDavid E. Box
679ced3ce76SDavid E. Box	  You should say Y if you are running a kernel on one of these SoC's.
680ced3ce76SDavid E. Box
681ed2226bdSDavid E. Boxconfig IOSF_MBI_DEBUG
682ed2226bdSDavid E. Box	bool "Enable IOSF sideband access through debugfs"
683ed2226bdSDavid E. Box	depends on IOSF_MBI && DEBUG_FS
684a7f7f624SMasahiro Yamada	help
685ed2226bdSDavid E. Box	  Select this option to expose the IOSF sideband access registers (MCR,
686ed2226bdSDavid E. Box	  MDR, MCRX) through debugfs to write and read register information from
687ed2226bdSDavid E. Box	  different units on the SoC. This is most useful for obtaining device
688ed2226bdSDavid E. Box	  state information for debug and analysis. As this is a general access
689ed2226bdSDavid E. Box	  mechanism, users of this option would have specific knowledge of the
690ed2226bdSDavid E. Box	  device they want to access.
691ed2226bdSDavid E. Box
692ed2226bdSDavid E. Box	  If you don't require the option or are in doubt, say N.
693ed2226bdSDavid E. Box
694c5c606d9SRavikiran G Thirumalaiconfig X86_RDC321X
695c5c606d9SRavikiran G Thirumalai	bool "RDC R-321x SoC"
696506f1d07SSam Ravnborg	depends on X86_32
697c5c606d9SRavikiran G Thirumalai	depends on X86_EXTENDED_PLATFORM
698c5c606d9SRavikiran G Thirumalai	select M486
699c5c606d9SRavikiran G Thirumalai	select X86_REBOOTFIXUPS
700a7f7f624SMasahiro Yamada	help
701c5c606d9SRavikiran G Thirumalai	  This option is needed for RDC R-321x system-on-chip, also known
702c5c606d9SRavikiran G Thirumalai	  as R-8610-(G).
703c5c606d9SRavikiran G Thirumalai	  If you don't have one of these chips, you should say N here.
704c5c606d9SRavikiran G Thirumalai
705e0c7ae37SIngo Molnarconfig X86_32_NON_STANDARD
7069c398017SIngo Molnar	bool "Support non-standard 32-bit SMP architectures"
7079c398017SIngo Molnar	depends on X86_32 && SMP
708c5c606d9SRavikiran G Thirumalai	depends on X86_EXTENDED_PLATFORM
709a7f7f624SMasahiro Yamada	help
710b5660ba7SH. Peter Anvin	  This option compiles in the bigsmp and STA2X11 default
711b5660ba7SH. Peter Anvin	  subarchitectures.  It is intended for a generic binary
712b5660ba7SH. Peter Anvin	  kernel. If you select them all, kernel will probe it one by
713b5660ba7SH. Peter Anvin	  one and will fallback to default.
714d49c4288SYinghai Lu
715c5c606d9SRavikiran G Thirumalai# Alphabetically sorted list of Non standard 32 bit platforms
716d49c4288SYinghai Lu
717d949f36fSLinus Torvaldsconfig X86_SUPPORTS_MEMORY_FAILURE
7186fc108a0SJan Beulich	def_bool y
719d949f36fSLinus Torvalds	# MCE code calls memory_failure():
720d949f36fSLinus Torvalds	depends on X86_MCE
721d949f36fSLinus Torvalds	# On 32-bit this adds too big of NODES_SHIFT and we run out of page flags:
722d949f36fSLinus Torvalds	# On 32-bit SPARSEMEM adds too big of SECTIONS_WIDTH:
723d949f36fSLinus Torvalds	depends on X86_64 || !SPARSEMEM
724d949f36fSLinus Torvalds	select ARCH_SUPPORTS_MEMORY_FAILURE
725d949f36fSLinus Torvalds
72683125a3aSAlessandro Rubiniconfig STA2X11
72783125a3aSAlessandro Rubini	bool "STA2X11 Companion Chip Support"
72883125a3aSAlessandro Rubini	depends on X86_32_NON_STANDARD && PCI
72983125a3aSAlessandro Rubini	select SWIOTLB
73083125a3aSAlessandro Rubini	select MFD_STA2X11
7310145071bSLinus Walleij	select GPIOLIB
732a7f7f624SMasahiro Yamada	help
73383125a3aSAlessandro Rubini	  This adds support for boards based on the STA2X11 IO-Hub,
73483125a3aSAlessandro Rubini	  a.k.a. "ConneXt". The chip is used in place of the standard
73583125a3aSAlessandro Rubini	  PC chipset, so all "standard" peripherals are missing. If this
73683125a3aSAlessandro Rubini	  option is selected the kernel will still be able to boot on
73783125a3aSAlessandro Rubini	  standard PC machines.
73883125a3aSAlessandro Rubini
73982148d1dSShérabconfig X86_32_IRIS
74082148d1dSShérab	tristate "Eurobraille/Iris poweroff module"
74182148d1dSShérab	depends on X86_32
742a7f7f624SMasahiro Yamada	help
74382148d1dSShérab	  The Iris machines from EuroBraille do not have APM or ACPI support
74482148d1dSShérab	  to shut themselves down properly.  A special I/O sequence is
74582148d1dSShérab	  needed to do so, which is what this module does at
74682148d1dSShérab	  kernel shutdown.
74782148d1dSShérab
74882148d1dSShérab	  This is only for Iris machines from EuroBraille.
74982148d1dSShérab
75082148d1dSShérab	  If unused, say N.
75182148d1dSShérab
752ae1e9130SIngo Molnarconfig SCHED_OMIT_FRAME_POINTER
7533c2362e6SHarvey Harrison	def_bool y
7543c2362e6SHarvey Harrison	prompt "Single-depth WCHAN output"
755a87d0914SKen Chen	depends on X86
756a7f7f624SMasahiro Yamada	help
757506f1d07SSam Ravnborg	  Calculate simpler /proc/<PID>/wchan values. If this option
758506f1d07SSam Ravnborg	  is disabled then wchan values will recurse back to the
759506f1d07SSam Ravnborg	  caller function. This provides more accurate wchan values,
760506f1d07SSam Ravnborg	  at the expense of slightly more scheduling overhead.
761506f1d07SSam Ravnborg
762506f1d07SSam Ravnborg	  If in doubt, say "Y".
763506f1d07SSam Ravnborg
7646276a074SBorislav Petkovmenuconfig HYPERVISOR_GUEST
7656276a074SBorislav Petkov	bool "Linux guest support"
766a7f7f624SMasahiro Yamada	help
7676276a074SBorislav Petkov	  Say Y here to enable options for running Linux under various hyper-
7686276a074SBorislav Petkov	  visors. This option enables basic hypervisor detection and platform
7696276a074SBorislav Petkov	  setup.
770506f1d07SSam Ravnborg
7716276a074SBorislav Petkov	  If you say N, all options in this submenu will be skipped and
7726276a074SBorislav Petkov	  disabled, and Linux guest support won't be built in.
773506f1d07SSam Ravnborg
7746276a074SBorislav Petkovif HYPERVISOR_GUEST
775506f1d07SSam Ravnborg
776e61bd94aSEduardo Pereira Habkostconfig PARAVIRT
777e61bd94aSEduardo Pereira Habkost	bool "Enable paravirtualization code"
778a0e2bf7cSJuergen Gross	depends on HAVE_STATIC_CALL
779a7f7f624SMasahiro Yamada	help
780e61bd94aSEduardo Pereira Habkost	  This changes the kernel so it can modify itself when it is run
781e61bd94aSEduardo Pereira Habkost	  under a hypervisor, potentially improving performance significantly
782e61bd94aSEduardo Pereira Habkost	  over full virtualization.  However, when run without a hypervisor
783e61bd94aSEduardo Pereira Habkost	  the kernel is theoretically slower and slightly larger.
784e61bd94aSEduardo Pereira Habkost
785c00a280aSJuergen Grossconfig PARAVIRT_XXL
786c00a280aSJuergen Gross	bool
787c00a280aSJuergen Gross
7886276a074SBorislav Petkovconfig PARAVIRT_DEBUG
7896276a074SBorislav Petkov	bool "paravirt-ops debugging"
7906276a074SBorislav Petkov	depends on PARAVIRT && DEBUG_KERNEL
791a7f7f624SMasahiro Yamada	help
7926276a074SBorislav Petkov	  Enable to debug paravirt_ops internals.  Specifically, BUG if
7936276a074SBorislav Petkov	  a paravirt_op is missing when it is called.
7946276a074SBorislav Petkov
795b4ecc126SJeremy Fitzhardingeconfig PARAVIRT_SPINLOCKS
796b4ecc126SJeremy Fitzhardinge	bool "Paravirtualization layer for spinlocks"
7976ea30386SKees Cook	depends on PARAVIRT && SMP
798a7f7f624SMasahiro Yamada	help
799b4ecc126SJeremy Fitzhardinge	  Paravirtualized spinlocks allow a pvops backend to replace the
800b4ecc126SJeremy Fitzhardinge	  spinlock implementation with something virtualization-friendly
801b4ecc126SJeremy Fitzhardinge	  (for example, block the virtual CPU rather than spinning).
802b4ecc126SJeremy Fitzhardinge
8034c4e4f61SRaghavendra K T	  It has a minimal impact on native kernels and gives a nice performance
8044c4e4f61SRaghavendra K T	  benefit on paravirtualized KVM / Xen kernels.
805b4ecc126SJeremy Fitzhardinge
8064c4e4f61SRaghavendra K T	  If you are unsure how to answer this question, answer Y.
807b4ecc126SJeremy Fitzhardinge
808ecca2502SZhao Yakuiconfig X86_HV_CALLBACK_VECTOR
809ecca2502SZhao Yakui	def_bool n
810ecca2502SZhao Yakui
8116276a074SBorislav Petkovsource "arch/x86/xen/Kconfig"
8126276a074SBorislav Petkov
8136276a074SBorislav Petkovconfig KVM_GUEST
8146276a074SBorislav Petkov	bool "KVM Guest support (including kvmclock)"
8156276a074SBorislav Petkov	depends on PARAVIRT
8166276a074SBorislav Petkov	select PARAVIRT_CLOCK
817a1c4423bSMarcelo Tosatti	select ARCH_CPUIDLE_HALTPOLL
818b1d40575SVitaly Kuznetsov	select X86_HV_CALLBACK_VECTOR
8196276a074SBorislav Petkov	default y
820a7f7f624SMasahiro Yamada	help
8216276a074SBorislav Petkov	  This option enables various optimizations for running under the KVM
8226276a074SBorislav Petkov	  hypervisor. It includes a paravirtualized clock, so that instead
8236276a074SBorislav Petkov	  of relying on a PIT (or probably other) emulation by the
8246276a074SBorislav Petkov	  underlying device model, the host provides the guest with
8256276a074SBorislav Petkov	  timing infrastructure such as time of day, and system time
8266276a074SBorislav Petkov
827a1c4423bSMarcelo Tosatticonfig ARCH_CPUIDLE_HALTPOLL
828a1c4423bSMarcelo Tosatti	def_bool n
829a1c4423bSMarcelo Tosatti	prompt "Disable host haltpoll when loading haltpoll driver"
830a1c4423bSMarcelo Tosatti	help
831a1c4423bSMarcelo Tosatti	  If virtualized under KVM, disable host haltpoll.
832a1c4423bSMarcelo Tosatti
8337733607fSMaran Wilsonconfig PVH
8347733607fSMaran Wilson	bool "Support for running PVH guests"
835a7f7f624SMasahiro Yamada	help
8367733607fSMaran Wilson	  This option enables the PVH entry point for guest virtual machines
8377733607fSMaran Wilson	  as specified in the x86/HVM direct boot ABI.
8387733607fSMaran Wilson
8396276a074SBorislav Petkovconfig PARAVIRT_TIME_ACCOUNTING
8406276a074SBorislav Petkov	bool "Paravirtual steal time accounting"
8416276a074SBorislav Petkov	depends on PARAVIRT
842a7f7f624SMasahiro Yamada	help
8436276a074SBorislav Petkov	  Select this option to enable fine granularity task steal time
8446276a074SBorislav Petkov	  accounting. Time spent executing other tasks in parallel with
8456276a074SBorislav Petkov	  the current vCPU is discounted from the vCPU power. To account for
8466276a074SBorislav Petkov	  that, there can be a small performance impact.
8476276a074SBorislav Petkov
8486276a074SBorislav Petkov	  If in doubt, say N here.
8496276a074SBorislav Petkov
8507af192c9SGerd Hoffmannconfig PARAVIRT_CLOCK
8517af192c9SGerd Hoffmann	bool
8527af192c9SGerd Hoffmann
8534a362601SJan Kiszkaconfig JAILHOUSE_GUEST
8544a362601SJan Kiszka	bool "Jailhouse non-root cell support"
855abde587bSArnd Bergmann	depends on X86_64 && PCI
85687e65d05SJan Kiszka	select X86_PM_TIMER
857a7f7f624SMasahiro Yamada	help
8584a362601SJan Kiszka	  This option allows to run Linux as guest in a Jailhouse non-root
8594a362601SJan Kiszka	  cell. You can leave this option disabled if you only want to start
8604a362601SJan Kiszka	  Jailhouse and run Linux afterwards in the root cell.
8614a362601SJan Kiszka
862ec7972c9SZhao Yakuiconfig ACRN_GUEST
863ec7972c9SZhao Yakui	bool "ACRN Guest support"
864ec7972c9SZhao Yakui	depends on X86_64
865498ad393SZhao Yakui	select X86_HV_CALLBACK_VECTOR
866ec7972c9SZhao Yakui	help
867ec7972c9SZhao Yakui	  This option allows to run Linux as guest in the ACRN hypervisor. ACRN is
868ec7972c9SZhao Yakui	  a flexible, lightweight reference open-source hypervisor, built with
869ec7972c9SZhao Yakui	  real-time and safety-criticality in mind. It is built for embedded
870ec7972c9SZhao Yakui	  IOT with small footprint and real-time features. More details can be
871ec7972c9SZhao Yakui	  found in https://projectacrn.org/.
872ec7972c9SZhao Yakui
87359bd54a8SKuppuswamy Sathyanarayananconfig INTEL_TDX_GUEST
87459bd54a8SKuppuswamy Sathyanarayanan	bool "Intel TDX (Trust Domain Extensions) - Guest Support"
87559bd54a8SKuppuswamy Sathyanarayanan	depends on X86_64 && CPU_SUP_INTEL
87659bd54a8SKuppuswamy Sathyanarayanan	depends on X86_X2APIC
87741394e33SKirill A. Shutemov	select ARCH_HAS_CC_PLATFORM
878968b4931SKirill A. Shutemov	select X86_MEM_ENCRYPT
87977a512e3SSean Christopherson	select X86_MCE
88059bd54a8SKuppuswamy Sathyanarayanan	help
88159bd54a8SKuppuswamy Sathyanarayanan	  Support running as a guest under Intel TDX.  Without this support,
88259bd54a8SKuppuswamy Sathyanarayanan	  the guest kernel can not boot or run under TDX.
88359bd54a8SKuppuswamy Sathyanarayanan	  TDX includes memory encryption and integrity capabilities
88459bd54a8SKuppuswamy Sathyanarayanan	  which protect the confidentiality and integrity of guest
88559bd54a8SKuppuswamy Sathyanarayanan	  memory contents and CPU state. TDX guests are protected from
88659bd54a8SKuppuswamy Sathyanarayanan	  some attacks from the VMM.
88759bd54a8SKuppuswamy Sathyanarayanan
8886276a074SBorislav Petkovendif # HYPERVISOR_GUEST
88997349135SJeremy Fitzhardinge
890506f1d07SSam Ravnborgsource "arch/x86/Kconfig.cpu"
891506f1d07SSam Ravnborg
892506f1d07SSam Ravnborgconfig HPET_TIMER
8933c2362e6SHarvey Harrison	def_bool X86_64
894506f1d07SSam Ravnborg	prompt "HPET Timer Support" if X86_32
895a7f7f624SMasahiro Yamada	help
896506f1d07SSam Ravnborg	  Use the IA-PC HPET (High Precision Event Timer) to manage
897506f1d07SSam Ravnborg	  time in preference to the PIT and RTC, if a HPET is
898506f1d07SSam Ravnborg	  present.
899506f1d07SSam Ravnborg	  HPET is the next generation timer replacing legacy 8254s.
900506f1d07SSam Ravnborg	  The HPET provides a stable time base on SMP
901506f1d07SSam Ravnborg	  systems, unlike the TSC, but it is more expensive to access,
9024e7f9df2SMichael S. Tsirkin	  as it is off-chip.  The interface used is documented
9034e7f9df2SMichael S. Tsirkin	  in the HPET spec, revision 1.
904506f1d07SSam Ravnborg
905506f1d07SSam Ravnborg	  You can safely choose Y here.  However, HPET will only be
906506f1d07SSam Ravnborg	  activated if the platform and the BIOS support this feature.
907506f1d07SSam Ravnborg	  Otherwise the 8254 will be used for timing services.
908506f1d07SSam Ravnborg
909506f1d07SSam Ravnborg	  Choose N to continue using the legacy 8254 timer.
910506f1d07SSam Ravnborg
911506f1d07SSam Ravnborgconfig HPET_EMULATE_RTC
9123c2362e6SHarvey Harrison	def_bool y
9133228e1dcSAnand K Mistry	depends on HPET_TIMER && (RTC_DRV_CMOS=m || RTC_DRV_CMOS=y)
914506f1d07SSam Ravnborg
9156a108a14SDavid Rientjes# Mark as expert because too many people got it wrong.
916506f1d07SSam Ravnborg# The code disables itself when not needed.
9177ae9392cSThomas Petazzoniconfig DMI
9187ae9392cSThomas Petazzoni	default y
919cf074402SArd Biesheuvel	select DMI_SCAN_MACHINE_NON_EFI_FALLBACK
9206a108a14SDavid Rientjes	bool "Enable DMI scanning" if EXPERT
921a7f7f624SMasahiro Yamada	help
9227ae9392cSThomas Petazzoni	  Enabled scanning of DMI to identify machine quirks. Say Y
9237ae9392cSThomas Petazzoni	  here unless you have verified that your setup is not
9247ae9392cSThomas Petazzoni	  affected by entries in the DMI blacklist. Required by PNP
9257ae9392cSThomas Petazzoni	  BIOS code.
9267ae9392cSThomas Petazzoni
927506f1d07SSam Ravnborgconfig GART_IOMMU
92838901f1cSAndi Kleen	bool "Old AMD GART IOMMU support"
9292f9237d4SChristoph Hellwig	select DMA_OPS
930a4ce5a48SChristoph Hellwig	select IOMMU_HELPER
931506f1d07SSam Ravnborg	select SWIOTLB
93223ac4ae8SAndreas Herrmann	depends on X86_64 && PCI && AMD_NB
933a7f7f624SMasahiro Yamada	help
934ced3c42cSIngo Molnar	  Provides a driver for older AMD Athlon64/Opteron/Turion/Sempron
935ced3c42cSIngo Molnar	  GART based hardware IOMMUs.
936ced3c42cSIngo Molnar
937ced3c42cSIngo Molnar	  The GART supports full DMA access for devices with 32-bit access
938ced3c42cSIngo Molnar	  limitations, on systems with more than 3 GB. This is usually needed
939ced3c42cSIngo Molnar	  for USB, sound, many IDE/SATA chipsets and some other devices.
940ced3c42cSIngo Molnar
941ced3c42cSIngo Molnar	  Newer systems typically have a modern AMD IOMMU, supported via
942ced3c42cSIngo Molnar	  the CONFIG_AMD_IOMMU=y config option.
943ced3c42cSIngo Molnar
944ced3c42cSIngo Molnar	  In normal configurations this driver is only active when needed:
945ced3c42cSIngo Molnar	  there's more than 3 GB of memory and the system contains a
946ced3c42cSIngo Molnar	  32-bit limited device.
947ced3c42cSIngo Molnar
948ced3c42cSIngo Molnar	  If unsure, say Y.
949506f1d07SSam Ravnborg
9508b766b0fSMichal Suchanekconfig BOOT_VESA_SUPPORT
9518b766b0fSMichal Suchanek	bool
9528b766b0fSMichal Suchanek	help
9538b766b0fSMichal Suchanek	  If true, at least one selected framebuffer driver can take advantage
9548b766b0fSMichal Suchanek	  of VESA video modes set at an early boot stage via the vga= parameter.
9558b766b0fSMichal Suchanek
9561184dc2fSMike Travisconfig MAXSMP
957ddb0c5a6SSamuel Thibault	bool "Enable Maximum number of SMP Processors and NUMA Nodes"
9586ea30386SKees Cook	depends on X86_64 && SMP && DEBUG_KERNEL
95936f5101aSMike Travis	select CPUMASK_OFFSTACK
960a7f7f624SMasahiro Yamada	help
961ddb0c5a6SSamuel Thibault	  Enable maximum number of CPUS and NUMA Nodes for this architecture.
9621184dc2fSMike Travis	  If unsure, say N.
963506f1d07SSam Ravnborg
964aec6487eSIngo Molnar#
965aec6487eSIngo Molnar# The maximum number of CPUs supported:
966aec6487eSIngo Molnar#
967aec6487eSIngo Molnar# The main config value is NR_CPUS, which defaults to NR_CPUS_DEFAULT,
968aec6487eSIngo Molnar# and which can be configured interactively in the
969aec6487eSIngo Molnar# [NR_CPUS_RANGE_BEGIN ... NR_CPUS_RANGE_END] range.
970aec6487eSIngo Molnar#
971aec6487eSIngo Molnar# The ranges are different on 32-bit and 64-bit kernels, depending on
972aec6487eSIngo Molnar# hardware capabilities and scalability features of the kernel.
973aec6487eSIngo Molnar#
974aec6487eSIngo Molnar# ( If MAXSMP is enabled we just use the highest possible value and disable
975aec6487eSIngo Molnar#   interactive configuration. )
976aec6487eSIngo Molnar#
977a0d0bb4dSRandy Dunlap
978aec6487eSIngo Molnarconfig NR_CPUS_RANGE_BEGIN
979a0d0bb4dSRandy Dunlap	int
980aec6487eSIngo Molnar	default NR_CPUS_RANGE_END if MAXSMP
981a0d0bb4dSRandy Dunlap	default    1 if !SMP
982a0d0bb4dSRandy Dunlap	default    2
983a0d0bb4dSRandy Dunlap
984aec6487eSIngo Molnarconfig NR_CPUS_RANGE_END
985a0d0bb4dSRandy Dunlap	int
986a0d0bb4dSRandy Dunlap	depends on X86_32
987aec6487eSIngo Molnar	default   64 if  SMP &&  X86_BIGSMP
988aec6487eSIngo Molnar	default    8 if  SMP && !X86_BIGSMP
989a0d0bb4dSRandy Dunlap	default    1 if !SMP
990a0d0bb4dSRandy Dunlap
991aec6487eSIngo Molnarconfig NR_CPUS_RANGE_END
992a0d0bb4dSRandy Dunlap	int
993a0d0bb4dSRandy Dunlap	depends on X86_64
9941edae1aeSScott Wood	default 8192 if  SMP && CPUMASK_OFFSTACK
9951edae1aeSScott Wood	default  512 if  SMP && !CPUMASK_OFFSTACK
996a0d0bb4dSRandy Dunlap	default    1 if !SMP
997aec6487eSIngo Molnar
998aec6487eSIngo Molnarconfig NR_CPUS_DEFAULT
999aec6487eSIngo Molnar	int
1000aec6487eSIngo Molnar	depends on X86_32
1001aec6487eSIngo Molnar	default   32 if  X86_BIGSMP
1002aec6487eSIngo Molnar	default    8 if  SMP
1003aec6487eSIngo Molnar	default    1 if !SMP
1004aec6487eSIngo Molnar
1005aec6487eSIngo Molnarconfig NR_CPUS_DEFAULT
1006aec6487eSIngo Molnar	int
1007aec6487eSIngo Molnar	depends on X86_64
1008a0d0bb4dSRandy Dunlap	default 8192 if  MAXSMP
1009a0d0bb4dSRandy Dunlap	default   64 if  SMP
1010aec6487eSIngo Molnar	default    1 if !SMP
1011a0d0bb4dSRandy Dunlap
1012506f1d07SSam Ravnborgconfig NR_CPUS
101336f5101aSMike Travis	int "Maximum number of CPUs" if SMP && !MAXSMP
1014aec6487eSIngo Molnar	range NR_CPUS_RANGE_BEGIN NR_CPUS_RANGE_END
1015aec6487eSIngo Molnar	default NR_CPUS_DEFAULT
1016a7f7f624SMasahiro Yamada	help
1017506f1d07SSam Ravnborg	  This allows you to specify the maximum number of CPUs which this
1018bb61ccc7SJosh Boyer	  kernel will support.  If CPUMASK_OFFSTACK is enabled, the maximum
1019cad14bb9SKirill A. Shutemov	  supported value is 8192, otherwise the maximum value is 512.  The
1020506f1d07SSam Ravnborg	  minimum value which makes sense is 2.
1021506f1d07SSam Ravnborg
1022aec6487eSIngo Molnar	  This is purely to save memory: each supported CPU adds about 8KB
1023aec6487eSIngo Molnar	  to the kernel image.
1024506f1d07SSam Ravnborg
102566558b73STim Chenconfig SCHED_CLUSTER
102666558b73STim Chen	bool "Cluster scheduler support"
102766558b73STim Chen	depends on SMP
102866558b73STim Chen	default y
102966558b73STim Chen	help
103066558b73STim Chen	  Cluster scheduler support improves the CPU scheduler's decision
103166558b73STim Chen	  making when dealing with machines that have clusters of CPUs.
103266558b73STim Chen	  Cluster usually means a couple of CPUs which are placed closely
103366558b73STim Chen	  by sharing mid-level caches, last-level cache tags or internal
103466558b73STim Chen	  busses.
103566558b73STim Chen
1036506f1d07SSam Ravnborgconfig SCHED_SMT
1037dbe73364SThomas Gleixner	def_bool y if SMP
1038506f1d07SSam Ravnborg
1039506f1d07SSam Ravnborgconfig SCHED_MC
10403c2362e6SHarvey Harrison	def_bool y
10413c2362e6SHarvey Harrison	prompt "Multi-core scheduler support"
1042c8e56d20SBorislav Petkov	depends on SMP
1043a7f7f624SMasahiro Yamada	help
1044506f1d07SSam Ravnborg	  Multi-core scheduler support improves the CPU scheduler's decision
1045506f1d07SSam Ravnborg	  making when dealing with multi-core CPU chips at a cost of slightly
1046506f1d07SSam Ravnborg	  increased overhead in some places. If unsure say N here.
1047506f1d07SSam Ravnborg
1048de966cf4STim Chenconfig SCHED_MC_PRIO
1049de966cf4STim Chen	bool "CPU core priorities scheduler support"
10500a21fc12SIngo Molnar	depends on SCHED_MC && CPU_SUP_INTEL
10510a21fc12SIngo Molnar	select X86_INTEL_PSTATE
10520a21fc12SIngo Molnar	select CPU_FREQ
1053de966cf4STim Chen	default y
1054a7f7f624SMasahiro Yamada	help
1055de966cf4STim Chen	  Intel Turbo Boost Max Technology 3.0 enabled CPUs have a
1056de966cf4STim Chen	  core ordering determined at manufacturing time, which allows
1057de966cf4STim Chen	  certain cores to reach higher turbo frequencies (when running
1058de966cf4STim Chen	  single threaded workloads) than others.
1059de966cf4STim Chen
1060de966cf4STim Chen	  Enabling this kernel feature teaches the scheduler about
1061de966cf4STim Chen	  the TBM3 (aka ITMT) priority order of the CPU cores and adjusts the
1062de966cf4STim Chen	  scheduler's CPU selection logic accordingly, so that higher
1063de966cf4STim Chen	  overall system performance can be achieved.
1064de966cf4STim Chen
1065de966cf4STim Chen	  This feature will have no effect on CPUs without this feature.
1066de966cf4STim Chen
1067de966cf4STim Chen	  If unsure say Y here.
10685e76b2abSTim Chen
106930b8b006SThomas Gleixnerconfig UP_LATE_INIT
107030b8b006SThomas Gleixner	def_bool y
1071ba360f88SThomas Gleixner	depends on !SMP && X86_LOCAL_APIC
107230b8b006SThomas Gleixner
1073506f1d07SSam Ravnborgconfig X86_UP_APIC
107450849eefSJan Beulich	bool "Local APIC support on uniprocessors" if !PCI_MSI
107550849eefSJan Beulich	default PCI_MSI
107638a1dfdaSBryan O'Donoghue	depends on X86_32 && !SMP && !X86_32_NON_STANDARD
1077a7f7f624SMasahiro Yamada	help
1078506f1d07SSam Ravnborg	  A local APIC (Advanced Programmable Interrupt Controller) is an
1079506f1d07SSam Ravnborg	  integrated interrupt controller in the CPU. If you have a single-CPU
1080506f1d07SSam Ravnborg	  system which has a processor with a local APIC, you can say Y here to
1081506f1d07SSam Ravnborg	  enable and use it. If you say Y here even though your machine doesn't
1082506f1d07SSam Ravnborg	  have a local APIC, then the kernel will still run with no slowdown at
1083506f1d07SSam Ravnborg	  all. The local APIC supports CPU-generated self-interrupts (timer,
1084506f1d07SSam Ravnborg	  performance counters), and the NMI watchdog which detects hard
1085506f1d07SSam Ravnborg	  lockups.
1086506f1d07SSam Ravnborg
1087506f1d07SSam Ravnborgconfig X86_UP_IOAPIC
1088506f1d07SSam Ravnborg	bool "IO-APIC support on uniprocessors"
1089506f1d07SSam Ravnborg	depends on X86_UP_APIC
1090a7f7f624SMasahiro Yamada	help
1091506f1d07SSam Ravnborg	  An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an
1092506f1d07SSam Ravnborg	  SMP-capable replacement for PC-style interrupt controllers. Most
1093506f1d07SSam Ravnborg	  SMP systems and many recent uniprocessor systems have one.
1094506f1d07SSam Ravnborg
1095506f1d07SSam Ravnborg	  If you have a single-CPU system with an IO-APIC, you can say Y here
1096506f1d07SSam Ravnborg	  to use it. If you say Y here even though your machine doesn't have
1097506f1d07SSam Ravnborg	  an IO-APIC, then the kernel will still run with no slowdown at all.
1098506f1d07SSam Ravnborg
1099506f1d07SSam Ravnborgconfig X86_LOCAL_APIC
11003c2362e6SHarvey Harrison	def_bool y
11010dbc6078SThomas Petazzoni	depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC || PCI_MSI
1102b5dc8e6cSJiang Liu	select IRQ_DOMAIN_HIERARCHY
110352f518a3SJiang Liu	select PCI_MSI_IRQ_DOMAIN if PCI_MSI
1104506f1d07SSam Ravnborg
1105506f1d07SSam Ravnborgconfig X86_IO_APIC
1106b1da1e71SJan Beulich	def_bool y
1107b1da1e71SJan Beulich	depends on X86_LOCAL_APIC || X86_UP_IOAPIC
1108506f1d07SSam Ravnborg
110941b9eb26SStefan Assmannconfig X86_REROUTE_FOR_BROKEN_BOOT_IRQS
111041b9eb26SStefan Assmann	bool "Reroute for broken boot IRQs"
111141b9eb26SStefan Assmann	depends on X86_IO_APIC
1112a7f7f624SMasahiro Yamada	help
111341b9eb26SStefan Assmann	  This option enables a workaround that fixes a source of
111441b9eb26SStefan Assmann	  spurious interrupts. This is recommended when threaded
111541b9eb26SStefan Assmann	  interrupt handling is used on systems where the generation of
111641b9eb26SStefan Assmann	  superfluous "boot interrupts" cannot be disabled.
111741b9eb26SStefan Assmann
111841b9eb26SStefan Assmann	  Some chipsets generate a legacy INTx "boot IRQ" when the IRQ
111941b9eb26SStefan Assmann	  entry in the chipset's IO-APIC is masked (as, e.g. the RT
112041b9eb26SStefan Assmann	  kernel does during interrupt handling). On chipsets where this
112141b9eb26SStefan Assmann	  boot IRQ generation cannot be disabled, this workaround keeps
112241b9eb26SStefan Assmann	  the original IRQ line masked so that only the equivalent "boot
112341b9eb26SStefan Assmann	  IRQ" is delivered to the CPUs. The workaround also tells the
112441b9eb26SStefan Assmann	  kernel to set up the IRQ handler on the boot IRQ line. In this
112541b9eb26SStefan Assmann	  way only one interrupt is delivered to the kernel. Otherwise
112641b9eb26SStefan Assmann	  the spurious second interrupt may cause the kernel to bring
112741b9eb26SStefan Assmann	  down (vital) interrupt lines.
112841b9eb26SStefan Assmann
112941b9eb26SStefan Assmann	  Only affects "broken" chipsets. Interrupt sharing may be
113041b9eb26SStefan Assmann	  increased on these systems.
113141b9eb26SStefan Assmann
1132506f1d07SSam Ravnborgconfig X86_MCE
1133bab9bc65SAndi Kleen	bool "Machine Check / overheating reporting"
1134648ed940SChen, Gong	select GENERIC_ALLOCATOR
1135e57dbaf7SBorislav Petkov	default y
1136a7f7f624SMasahiro Yamada	help
1137bab9bc65SAndi Kleen	  Machine Check support allows the processor to notify the
1138bab9bc65SAndi Kleen	  kernel if it detects a problem (e.g. overheating, data corruption).
1139506f1d07SSam Ravnborg	  The action the kernel takes depends on the severity of the problem,
1140bab9bc65SAndi Kleen	  ranging from warning messages to halting the machine.
11414efc0670SAndi Kleen
11425de97c9fSTony Luckconfig X86_MCELOG_LEGACY
11435de97c9fSTony Luck	bool "Support for deprecated /dev/mcelog character device"
11445de97c9fSTony Luck	depends on X86_MCE
1145a7f7f624SMasahiro Yamada	help
11465de97c9fSTony Luck	  Enable support for /dev/mcelog which is needed by the old mcelog
11475de97c9fSTony Luck	  userspace logging daemon. Consider switching to the new generation
11485de97c9fSTony Luck	  rasdaemon solution.
11495de97c9fSTony Luck
1150506f1d07SSam Ravnborgconfig X86_MCE_INTEL
11513c2362e6SHarvey Harrison	def_bool y
11523c2362e6SHarvey Harrison	prompt "Intel MCE features"
1153c1ebf835SAndi Kleen	depends on X86_MCE && X86_LOCAL_APIC
1154a7f7f624SMasahiro Yamada	help
1155506f1d07SSam Ravnborg	  Additional support for intel specific MCE features such as
1156506f1d07SSam Ravnborg	  the thermal monitor.
1157506f1d07SSam Ravnborg
1158506f1d07SSam Ravnborgconfig X86_MCE_AMD
11593c2362e6SHarvey Harrison	def_bool y
11603c2362e6SHarvey Harrison	prompt "AMD MCE features"
1161f5382de9SYazen Ghannam	depends on X86_MCE && X86_LOCAL_APIC && AMD_NB
1162a7f7f624SMasahiro Yamada	help
1163506f1d07SSam Ravnborg	  Additional support for AMD specific MCE features such as
1164506f1d07SSam Ravnborg	  the DRAM Error Threshold.
1165506f1d07SSam Ravnborg
11664efc0670SAndi Kleenconfig X86_ANCIENT_MCE
11676fc108a0SJan Beulich	bool "Support for old Pentium 5 / WinChip machine checks"
1168c31d9633SAndi Kleen	depends on X86_32 && X86_MCE
1169a7f7f624SMasahiro Yamada	help
11704efc0670SAndi Kleen	  Include support for machine check handling on old Pentium 5 or WinChip
11715065a706SMasanari Iida	  systems. These typically need to be enabled explicitly on the command
11724efc0670SAndi Kleen	  line.
11734efc0670SAndi Kleen
1174b2762686SAndi Kleenconfig X86_MCE_THRESHOLD
1175b2762686SAndi Kleen	depends on X86_MCE_AMD || X86_MCE_INTEL
11766fc108a0SJan Beulich	def_bool y
1177b2762686SAndi Kleen
1178ea149b36SAndi Kleenconfig X86_MCE_INJECT
1179bc8e80d5SBorislav Petkov	depends on X86_MCE && X86_LOCAL_APIC && DEBUG_FS
1180ea149b36SAndi Kleen	tristate "Machine check injector support"
1181a7f7f624SMasahiro Yamada	help
1182ea149b36SAndi Kleen	  Provide support for injecting machine checks for testing purposes.
1183ea149b36SAndi Kleen	  If you don't know what a machine check is and you don't do kernel
1184ea149b36SAndi Kleen	  QA it is safe to say n.
1185ea149b36SAndi Kleen
118607dc900eSPeter Zijlstrasource "arch/x86/events/Kconfig"
1187e633c65aSKan Liang
11885aef51c3SAndy Lutomirskiconfig X86_LEGACY_VM86
11891e642812SIngo Molnar	bool "Legacy VM86 support"
1190506f1d07SSam Ravnborg	depends on X86_32
1191a7f7f624SMasahiro Yamada	help
11925aef51c3SAndy Lutomirski	  This option allows user programs to put the CPU into V8086
11935aef51c3SAndy Lutomirski	  mode, which is an 80286-era approximation of 16-bit real mode.
11945aef51c3SAndy Lutomirski
11955aef51c3SAndy Lutomirski	  Some very old versions of X and/or vbetool require this option
11965aef51c3SAndy Lutomirski	  for user mode setting.  Similarly, DOSEMU will use it if
11975aef51c3SAndy Lutomirski	  available to accelerate real mode DOS programs.  However, any
11985aef51c3SAndy Lutomirski	  recent version of DOSEMU, X, or vbetool should be fully
11995aef51c3SAndy Lutomirski	  functional even without kernel VM86 support, as they will all
12001e642812SIngo Molnar	  fall back to software emulation. Nevertheless, if you are using
12011e642812SIngo Molnar	  a 16-bit DOS program where 16-bit performance matters, vm86
12021e642812SIngo Molnar	  mode might be faster than emulation and you might want to
12031e642812SIngo Molnar	  enable this option.
12045aef51c3SAndy Lutomirski
12051e642812SIngo Molnar	  Note that any app that works on a 64-bit kernel is unlikely to
12061e642812SIngo Molnar	  need this option, as 64-bit kernels don't, and can't, support
12071e642812SIngo Molnar	  V8086 mode. This option is also unrelated to 16-bit protected
12081e642812SIngo Molnar	  mode and is not needed to run most 16-bit programs under Wine.
12095aef51c3SAndy Lutomirski
12101e642812SIngo Molnar	  Enabling this option increases the complexity of the kernel
12111e642812SIngo Molnar	  and slows down exception handling a tiny bit.
12125aef51c3SAndy Lutomirski
12131e642812SIngo Molnar	  If unsure, say N here.
12145aef51c3SAndy Lutomirski
12155aef51c3SAndy Lutomirskiconfig VM86
12165aef51c3SAndy Lutomirski	bool
12175aef51c3SAndy Lutomirski	default X86_LEGACY_VM86
121834273f41SH. Peter Anvin
121934273f41SH. Peter Anvinconfig X86_16BIT
122034273f41SH. Peter Anvin	bool "Enable support for 16-bit segments" if EXPERT
122134273f41SH. Peter Anvin	default y
1222a5b9e5a2SAndy Lutomirski	depends on MODIFY_LDT_SYSCALL
1223a7f7f624SMasahiro Yamada	help
122434273f41SH. Peter Anvin	  This option is required by programs like Wine to run 16-bit
122534273f41SH. Peter Anvin	  protected mode legacy code on x86 processors.  Disabling
122634273f41SH. Peter Anvin	  this option saves about 300 bytes on i386, or around 6K text
122734273f41SH. Peter Anvin	  plus 16K runtime memory on x86-64,
122834273f41SH. Peter Anvin
122934273f41SH. Peter Anvinconfig X86_ESPFIX32
123034273f41SH. Peter Anvin	def_bool y
123134273f41SH. Peter Anvin	depends on X86_16BIT && X86_32
1232506f1d07SSam Ravnborg
1233197725deSH. Peter Anvinconfig X86_ESPFIX64
1234197725deSH. Peter Anvin	def_bool y
123534273f41SH. Peter Anvin	depends on X86_16BIT && X86_64
1236506f1d07SSam Ravnborg
12371ad83c85SAndy Lutomirskiconfig X86_VSYSCALL_EMULATION
12381ad83c85SAndy Lutomirski	bool "Enable vsyscall emulation" if EXPERT
12391ad83c85SAndy Lutomirski	default y
12401ad83c85SAndy Lutomirski	depends on X86_64
1241a7f7f624SMasahiro Yamada	help
12421ad83c85SAndy Lutomirski	  This enables emulation of the legacy vsyscall page.  Disabling
12431ad83c85SAndy Lutomirski	  it is roughly equivalent to booting with vsyscall=none, except
12441ad83c85SAndy Lutomirski	  that it will also disable the helpful warning if a program
12451ad83c85SAndy Lutomirski	  tries to use a vsyscall.  With this option set to N, offending
12461ad83c85SAndy Lutomirski	  programs will just segfault, citing addresses of the form
12471ad83c85SAndy Lutomirski	  0xffffffffff600?00.
12481ad83c85SAndy Lutomirski
12491ad83c85SAndy Lutomirski	  This option is required by many programs built before 2013, and
12501ad83c85SAndy Lutomirski	  care should be used even with newer programs if set to N.
12511ad83c85SAndy Lutomirski
12521ad83c85SAndy Lutomirski	  Disabling this option saves about 7K of kernel size and
12531ad83c85SAndy Lutomirski	  possibly 4K of additional runtime pagetable memory.
12541ad83c85SAndy Lutomirski
1255111e7b15SThomas Gleixnerconfig X86_IOPL_IOPERM
1256111e7b15SThomas Gleixner	bool "IOPERM and IOPL Emulation"
1257a24ca997SThomas Gleixner	default y
1258a7f7f624SMasahiro Yamada	help
1259111e7b15SThomas Gleixner	  This enables the ioperm() and iopl() syscalls which are necessary
1260111e7b15SThomas Gleixner	  for legacy applications.
1261111e7b15SThomas Gleixner
1262c8137aceSThomas Gleixner	  Legacy IOPL support is an overbroad mechanism which allows user
1263c8137aceSThomas Gleixner	  space aside of accessing all 65536 I/O ports also to disable
1264c8137aceSThomas Gleixner	  interrupts. To gain this access the caller needs CAP_SYS_RAWIO
1265c8137aceSThomas Gleixner	  capabilities and permission from potentially active security
1266c8137aceSThomas Gleixner	  modules.
1267c8137aceSThomas Gleixner
1268c8137aceSThomas Gleixner	  The emulation restricts the functionality of the syscall to
1269c8137aceSThomas Gleixner	  only allowing the full range I/O port access, but prevents the
1270a24ca997SThomas Gleixner	  ability to disable interrupts from user space which would be
1271a24ca997SThomas Gleixner	  granted if the hardware IOPL mechanism would be used.
1272c8137aceSThomas Gleixner
1273506f1d07SSam Ravnborgconfig TOSHIBA
1274506f1d07SSam Ravnborg	tristate "Toshiba Laptop support"
1275506f1d07SSam Ravnborg	depends on X86_32
1276a7f7f624SMasahiro Yamada	help
1277506f1d07SSam Ravnborg	  This adds a driver to safely access the System Management Mode of
1278506f1d07SSam Ravnborg	  the CPU on Toshiba portables with a genuine Toshiba BIOS. It does
1279506f1d07SSam Ravnborg	  not work on models with a Phoenix BIOS. The System Management Mode
1280506f1d07SSam Ravnborg	  is used to set the BIOS and power saving options on Toshiba portables.
1281506f1d07SSam Ravnborg
1282506f1d07SSam Ravnborg	  For information on utilities to make use of this driver see the
1283506f1d07SSam Ravnborg	  Toshiba Linux utilities web site at:
1284506f1d07SSam Ravnborg	  <http://www.buzzard.org.uk/toshiba/>.
1285506f1d07SSam Ravnborg
1286506f1d07SSam Ravnborg	  Say Y if you intend to run this kernel on a Toshiba portable.
1287506f1d07SSam Ravnborg	  Say N otherwise.
1288506f1d07SSam Ravnborg
1289506f1d07SSam Ravnborgconfig X86_REBOOTFIXUPS
12909ba16087SJan Beulich	bool "Enable X86 board specific fixups for reboot"
12919ba16087SJan Beulich	depends on X86_32
1292a7f7f624SMasahiro Yamada	help
1293506f1d07SSam Ravnborg	  This enables chipset and/or board specific fixups to be done
1294506f1d07SSam Ravnborg	  in order to get reboot to work correctly. This is only needed on
1295506f1d07SSam Ravnborg	  some combinations of hardware and BIOS. The symptom, for which
1296506f1d07SSam Ravnborg	  this config is intended, is when reboot ends with a stalled/hung
1297506f1d07SSam Ravnborg	  system.
1298506f1d07SSam Ravnborg
1299506f1d07SSam Ravnborg	  Currently, the only fixup is for the Geode machines using
13005e3a77e9SFlorian Fainelli	  CS5530A and CS5536 chipsets and the RDC R-321x SoC.
1301506f1d07SSam Ravnborg
1302506f1d07SSam Ravnborg	  Say Y if you want to enable the fixup. Currently, it's safe to
1303506f1d07SSam Ravnborg	  enable this option even if you don't need it.
1304506f1d07SSam Ravnborg	  Say N otherwise.
1305506f1d07SSam Ravnborg
1306506f1d07SSam Ravnborgconfig MICROCODE
13079a2bc335SBorislav Petkov	bool "CPU microcode loading support"
13089a2bc335SBorislav Petkov	default y
130980030e3dSBorislav Petkov	depends on CPU_SUP_AMD || CPU_SUP_INTEL
1310a7f7f624SMasahiro Yamada	help
1311506f1d07SSam Ravnborg	  If you say Y here, you will be able to update the microcode on
13125f9c01aaSBorislav Petkov	  Intel and AMD processors. The Intel support is for the IA32 family,
13135f9c01aaSBorislav Petkov	  e.g. Pentium Pro, Pentium II, Pentium III, Pentium 4, Xeon etc. The
13145f9c01aaSBorislav Petkov	  AMD support is for families 0x10 and later. You will obviously need
13155f9c01aaSBorislav Petkov	  the actual microcode binary data itself which is not shipped with
13165f9c01aaSBorislav Petkov	  the Linux kernel.
1317506f1d07SSam Ravnborg
13185f9c01aaSBorislav Petkov	  The preferred method to load microcode from a detached initrd is described
1319cb1aaebeSMauro Carvalho Chehab	  in Documentation/x86/microcode.rst. For that you need to enable
13205f9c01aaSBorislav Petkov	  CONFIG_BLK_DEV_INITRD in order for the loader to be able to scan the
13215f9c01aaSBorislav Petkov	  initrd for microcode blobs.
1322506f1d07SSam Ravnborg
1323c508c46eSBenjamin Gilbert	  In addition, you can build the microcode into the kernel. For that you
1324c508c46eSBenjamin Gilbert	  need to add the vendor-supplied microcode to the CONFIG_EXTRA_FIRMWARE
1325c508c46eSBenjamin Gilbert	  config option.
1326506f1d07SSam Ravnborg
13278d86f390SPeter Orubaconfig MICROCODE_INTEL
1328e43f6e67SBorislav Petkov	bool "Intel microcode loading support"
13299c55d99eSBorislav Petkov	depends on CPU_SUP_INTEL && MICROCODE
13308d86f390SPeter Oruba	default MICROCODE
1331a7f7f624SMasahiro Yamada	help
13328d86f390SPeter Oruba	  This options enables microcode patch loading support for Intel
13338d86f390SPeter Oruba	  processors.
13348d86f390SPeter Oruba
1335b8989db9SAlan	  For the current Intel microcode data package go to
1336b8989db9SAlan	  <https://downloadcenter.intel.com> and search for
1337b8989db9SAlan	  'Linux Processor Microcode Data File'.
13388d86f390SPeter Oruba
133980cc9f10SPeter Orubaconfig MICROCODE_AMD
1340e43f6e67SBorislav Petkov	bool "AMD microcode loading support"
13419c55d99eSBorislav Petkov	depends on CPU_SUP_AMD && MICROCODE
1342a7f7f624SMasahiro Yamada	help
134380cc9f10SPeter Oruba	  If you select this option, microcode patch loading support for AMD
134480cc9f10SPeter Oruba	  processors will be enabled.
134580cc9f10SPeter Oruba
1346a77a94f8SBorislav Petkovconfig MICROCODE_LATE_LOADING
1347a77a94f8SBorislav Petkov	bool "Late microcode loading (DANGEROUS)"
1348c02f48e0SBorislav Petkov	default n
1349506f1d07SSam Ravnborg	depends on MICROCODE
1350a7f7f624SMasahiro Yamada	help
1351a77a94f8SBorislav Petkov	  Loading microcode late, when the system is up and executing instructions
1352a77a94f8SBorislav Petkov	  is a tricky business and should be avoided if possible. Just the sequence
1353a77a94f8SBorislav Petkov	  of synchronizing all cores and SMT threads is one fragile dance which does
1354a77a94f8SBorislav Petkov	  not guarantee that cores might not softlock after the loading. Therefore,
1355a77a94f8SBorislav Petkov	  use this at your own risk. Late loading taints the kernel too.
1356506f1d07SSam Ravnborg
1357506f1d07SSam Ravnborgconfig X86_MSR
1358506f1d07SSam Ravnborg	tristate "/dev/cpu/*/msr - Model-specific register support"
1359a7f7f624SMasahiro Yamada	help
1360506f1d07SSam Ravnborg	  This device gives privileged processes access to the x86
1361506f1d07SSam Ravnborg	  Model-Specific Registers (MSRs).  It is a character device with
1362506f1d07SSam Ravnborg	  major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr.
1363506f1d07SSam Ravnborg	  MSR accesses are directed to a specific CPU on multi-processor
1364506f1d07SSam Ravnborg	  systems.
1365506f1d07SSam Ravnborg
1366506f1d07SSam Ravnborgconfig X86_CPUID
1367506f1d07SSam Ravnborg	tristate "/dev/cpu/*/cpuid - CPU information support"
1368a7f7f624SMasahiro Yamada	help
1369506f1d07SSam Ravnborg	  This device gives processes access to the x86 CPUID instruction to
1370506f1d07SSam Ravnborg	  be executed on a specific processor.  It is a character device
1371506f1d07SSam Ravnborg	  with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to
1372506f1d07SSam Ravnborg	  /dev/cpu/31/cpuid.
1373506f1d07SSam Ravnborg
1374506f1d07SSam Ravnborgchoice
1375506f1d07SSam Ravnborg	prompt "High Memory Support"
13766fc108a0SJan Beulich	default HIGHMEM4G
1377506f1d07SSam Ravnborg	depends on X86_32
1378506f1d07SSam Ravnborg
1379506f1d07SSam Ravnborgconfig NOHIGHMEM
1380506f1d07SSam Ravnborg	bool "off"
1381a7f7f624SMasahiro Yamada	help
1382506f1d07SSam Ravnborg	  Linux can use up to 64 Gigabytes of physical memory on x86 systems.
1383506f1d07SSam Ravnborg	  However, the address space of 32-bit x86 processors is only 4
1384506f1d07SSam Ravnborg	  Gigabytes large. That means that, if you have a large amount of
1385506f1d07SSam Ravnborg	  physical memory, not all of it can be "permanently mapped" by the
1386506f1d07SSam Ravnborg	  kernel. The physical memory that's not permanently mapped is called
1387506f1d07SSam Ravnborg	  "high memory".
1388506f1d07SSam Ravnborg
1389506f1d07SSam Ravnborg	  If you are compiling a kernel which will never run on a machine with
1390506f1d07SSam Ravnborg	  more than 1 Gigabyte total physical RAM, answer "off" here (default
1391506f1d07SSam Ravnborg	  choice and suitable for most users). This will result in a "3GB/1GB"
1392506f1d07SSam Ravnborg	  split: 3GB are mapped so that each process sees a 3GB virtual memory
1393506f1d07SSam Ravnborg	  space and the remaining part of the 4GB virtual memory space is used
1394506f1d07SSam Ravnborg	  by the kernel to permanently map as much physical memory as
1395506f1d07SSam Ravnborg	  possible.
1396506f1d07SSam Ravnborg
1397506f1d07SSam Ravnborg	  If the machine has between 1 and 4 Gigabytes physical RAM, then
1398506f1d07SSam Ravnborg	  answer "4GB" here.
1399506f1d07SSam Ravnborg
1400506f1d07SSam Ravnborg	  If more than 4 Gigabytes is used then answer "64GB" here. This
1401506f1d07SSam Ravnborg	  selection turns Intel PAE (Physical Address Extension) mode on.
1402506f1d07SSam Ravnborg	  PAE implements 3-level paging on IA32 processors. PAE is fully
1403506f1d07SSam Ravnborg	  supported by Linux, PAE mode is implemented on all recent Intel
1404506f1d07SSam Ravnborg	  processors (Pentium Pro and better). NOTE: If you say "64GB" here,
1405506f1d07SSam Ravnborg	  then the kernel will not boot on CPUs that don't support PAE!
1406506f1d07SSam Ravnborg
1407506f1d07SSam Ravnborg	  The actual amount of total physical memory will either be
1408506f1d07SSam Ravnborg	  auto detected or can be forced by using a kernel command line option
1409506f1d07SSam Ravnborg	  such as "mem=256M". (Try "man bootparam" or see the documentation of
1410506f1d07SSam Ravnborg	  your boot loader (lilo or loadlin) about how to pass options to the
1411506f1d07SSam Ravnborg	  kernel at boot time.)
1412506f1d07SSam Ravnborg
1413506f1d07SSam Ravnborg	  If unsure, say "off".
1414506f1d07SSam Ravnborg
1415506f1d07SSam Ravnborgconfig HIGHMEM4G
1416506f1d07SSam Ravnborg	bool "4GB"
1417a7f7f624SMasahiro Yamada	help
1418506f1d07SSam Ravnborg	  Select this if you have a 32-bit processor and between 1 and 4
1419506f1d07SSam Ravnborg	  gigabytes of physical RAM.
1420506f1d07SSam Ravnborg
1421506f1d07SSam Ravnborgconfig HIGHMEM64G
1422506f1d07SSam Ravnborg	bool "64GB"
1423225bac2dSLukas Bulwahn	depends on !M486SX && !M486 && !M586 && !M586TSC && !M586MMX && !MGEODE_LX && !MGEODEGX1 && !MCYRIXIII && !MELAN && !MWINCHIPC6 && !MWINCHIP3D && !MK6
1424506f1d07SSam Ravnborg	select X86_PAE
1425a7f7f624SMasahiro Yamada	help
1426506f1d07SSam Ravnborg	  Select this if you have a 32-bit processor and more than 4
1427506f1d07SSam Ravnborg	  gigabytes of physical RAM.
1428506f1d07SSam Ravnborg
1429506f1d07SSam Ravnborgendchoice
1430506f1d07SSam Ravnborg
1431506f1d07SSam Ravnborgchoice
14326a108a14SDavid Rientjes	prompt "Memory split" if EXPERT
1433506f1d07SSam Ravnborg	default VMSPLIT_3G
1434506f1d07SSam Ravnborg	depends on X86_32
1435a7f7f624SMasahiro Yamada	help
1436506f1d07SSam Ravnborg	  Select the desired split between kernel and user memory.
1437506f1d07SSam Ravnborg
1438506f1d07SSam Ravnborg	  If the address range available to the kernel is less than the
1439506f1d07SSam Ravnborg	  physical memory installed, the remaining memory will be available
1440506f1d07SSam Ravnborg	  as "high memory". Accessing high memory is a little more costly
1441506f1d07SSam Ravnborg	  than low memory, as it needs to be mapped into the kernel first.
1442506f1d07SSam Ravnborg	  Note that increasing the kernel address space limits the range
1443506f1d07SSam Ravnborg	  available to user programs, making the address space there
1444506f1d07SSam Ravnborg	  tighter.  Selecting anything other than the default 3G/1G split
1445506f1d07SSam Ravnborg	  will also likely make your kernel incompatible with binary-only
1446506f1d07SSam Ravnborg	  kernel modules.
1447506f1d07SSam Ravnborg
1448506f1d07SSam Ravnborg	  If you are not absolutely sure what you are doing, leave this
1449506f1d07SSam Ravnborg	  option alone!
1450506f1d07SSam Ravnborg
1451506f1d07SSam Ravnborg	config VMSPLIT_3G
1452506f1d07SSam Ravnborg		bool "3G/1G user/kernel split"
1453506f1d07SSam Ravnborg	config VMSPLIT_3G_OPT
1454506f1d07SSam Ravnborg		depends on !X86_PAE
1455506f1d07SSam Ravnborg		bool "3G/1G user/kernel split (for full 1G low memory)"
1456506f1d07SSam Ravnborg	config VMSPLIT_2G
1457506f1d07SSam Ravnborg		bool "2G/2G user/kernel split"
1458506f1d07SSam Ravnborg	config VMSPLIT_2G_OPT
1459506f1d07SSam Ravnborg		depends on !X86_PAE
1460506f1d07SSam Ravnborg		bool "2G/2G user/kernel split (for full 2G low memory)"
1461506f1d07SSam Ravnborg	config VMSPLIT_1G
1462506f1d07SSam Ravnborg		bool "1G/3G user/kernel split"
1463506f1d07SSam Ravnborgendchoice
1464506f1d07SSam Ravnborg
1465506f1d07SSam Ravnborgconfig PAGE_OFFSET
1466506f1d07SSam Ravnborg	hex
1467506f1d07SSam Ravnborg	default 0xB0000000 if VMSPLIT_3G_OPT
1468506f1d07SSam Ravnborg	default 0x80000000 if VMSPLIT_2G
1469506f1d07SSam Ravnborg	default 0x78000000 if VMSPLIT_2G_OPT
1470506f1d07SSam Ravnborg	default 0x40000000 if VMSPLIT_1G
1471506f1d07SSam Ravnborg	default 0xC0000000
1472506f1d07SSam Ravnborg	depends on X86_32
1473506f1d07SSam Ravnborg
1474506f1d07SSam Ravnborgconfig HIGHMEM
14753c2362e6SHarvey Harrison	def_bool y
1476506f1d07SSam Ravnborg	depends on X86_32 && (HIGHMEM64G || HIGHMEM4G)
1477506f1d07SSam Ravnborg
1478506f1d07SSam Ravnborgconfig X86_PAE
14799ba16087SJan Beulich	bool "PAE (Physical Address Extension) Support"
1480506f1d07SSam Ravnborg	depends on X86_32 && !HIGHMEM4G
1481d4a451d5SChristoph Hellwig	select PHYS_ADDR_T_64BIT
14829d99c712SChristian Melki	select SWIOTLB
1483a7f7f624SMasahiro Yamada	help
1484506f1d07SSam Ravnborg	  PAE is required for NX support, and furthermore enables
1485506f1d07SSam Ravnborg	  larger swapspace support for non-overcommit purposes. It
1486506f1d07SSam Ravnborg	  has the cost of more pagetable lookup overhead, and also
1487506f1d07SSam Ravnborg	  consumes more pagetable space per process.
1488506f1d07SSam Ravnborg
148977ef56e4SKirill A. Shutemovconfig X86_5LEVEL
149077ef56e4SKirill A. Shutemov	bool "Enable 5-level page tables support"
149118ec1eafSKirill A. Shutemov	default y
1492eedb92abSKirill A. Shutemov	select DYNAMIC_MEMORY_LAYOUT
1493162434e7SKirill A. Shutemov	select SPARSEMEM_VMEMMAP
149477ef56e4SKirill A. Shutemov	depends on X86_64
1495a7f7f624SMasahiro Yamada	help
149677ef56e4SKirill A. Shutemov	  5-level paging enables access to larger address space:
149777ef56e4SKirill A. Shutemov	  upto 128 PiB of virtual address space and 4 PiB of
149877ef56e4SKirill A. Shutemov	  physical address space.
149977ef56e4SKirill A. Shutemov
150077ef56e4SKirill A. Shutemov	  It will be supported by future Intel CPUs.
150177ef56e4SKirill A. Shutemov
15026657fca0SKirill A. Shutemov	  A kernel with the option enabled can be booted on machines that
15036657fca0SKirill A. Shutemov	  support 4- or 5-level paging.
150477ef56e4SKirill A. Shutemov
1505cb1aaebeSMauro Carvalho Chehab	  See Documentation/x86/x86_64/5level-paging.rst for more
150677ef56e4SKirill A. Shutemov	  information.
150777ef56e4SKirill A. Shutemov
150877ef56e4SKirill A. Shutemov	  Say N if unsure.
150977ef56e4SKirill A. Shutemov
151010971ab2SIngo Molnarconfig X86_DIRECT_GBPAGES
1511e5008abeSLuis R. Rodriguez	def_bool y
15122e1da13fSVlastimil Babka	depends on X86_64
1513a7f7f624SMasahiro Yamada	help
151410971ab2SIngo Molnar	  Certain kernel features effectively disable kernel
151510971ab2SIngo Molnar	  linear 1 GB mappings (even if the CPU otherwise
151610971ab2SIngo Molnar	  supports them), so don't confuse the user by printing
151710971ab2SIngo Molnar	  that we have them enabled.
15189e899816SNick Piggin
15195c280cf6SThomas Gleixnerconfig X86_CPA_STATISTICS
15205c280cf6SThomas Gleixner	bool "Enable statistic for Change Page Attribute"
15215c280cf6SThomas Gleixner	depends on DEBUG_FS
1522a7f7f624SMasahiro Yamada	help
1523b75baaf3SIngo Molnar	  Expose statistics about the Change Page Attribute mechanism, which
1524a943245aSColin Ian King	  helps to determine the effectiveness of preserving large and huge
15255c280cf6SThomas Gleixner	  page mappings when mapping protections are changed.
15265c280cf6SThomas Gleixner
152720f07a04SKirill A. Shutemovconfig X86_MEM_ENCRYPT
152820f07a04SKirill A. Shutemov	select ARCH_HAS_FORCE_DMA_UNENCRYPTED
152920f07a04SKirill A. Shutemov	select DYNAMIC_PHYSICAL_MASK
153020f07a04SKirill A. Shutemov	def_bool n
153120f07a04SKirill A. Shutemov
15327744ccdbSTom Lendackyconfig AMD_MEM_ENCRYPT
15337744ccdbSTom Lendacky	bool "AMD Secure Memory Encryption (SME) support"
15347744ccdbSTom Lendacky	depends on X86_64 && CPU_SUP_AMD
153582fef0adSDavid Rientjes	select DMA_COHERENT_POOL
1536ce9084baSArd Biesheuvel	select ARCH_USE_MEMREMAP_PROT
1537597cfe48SJoerg Roedel	select INSTRUCTION_DECODER
1538aa5a4611STom Lendacky	select ARCH_HAS_CC_PLATFORM
153920f07a04SKirill A. Shutemov	select X86_MEM_ENCRYPT
1540a7f7f624SMasahiro Yamada	help
15417744ccdbSTom Lendacky	  Say yes to enable support for the encryption of system memory.
15427744ccdbSTom Lendacky	  This requires an AMD processor that supports Secure Memory
15437744ccdbSTom Lendacky	  Encryption (SME).
15447744ccdbSTom Lendacky
15457744ccdbSTom Lendackyconfig AMD_MEM_ENCRYPT_ACTIVE_BY_DEFAULT
15467744ccdbSTom Lendacky	bool "Activate AMD Secure Memory Encryption (SME) by default"
15477744ccdbSTom Lendacky	depends on AMD_MEM_ENCRYPT
1548a7f7f624SMasahiro Yamada	help
15497744ccdbSTom Lendacky	  Say yes to have system memory encrypted by default if running on
15507744ccdbSTom Lendacky	  an AMD processor that supports Secure Memory Encryption (SME).
15517744ccdbSTom Lendacky
15527744ccdbSTom Lendacky	  If set to Y, then the encryption of system memory can be
15537744ccdbSTom Lendacky	  deactivated with the mem_encrypt=off command line option.
15547744ccdbSTom Lendacky
15557744ccdbSTom Lendacky	  If set to N, then the encryption of system memory can be
15567744ccdbSTom Lendacky	  activated with the mem_encrypt=on command line option.
15577744ccdbSTom Lendacky
1558506f1d07SSam Ravnborg# Common NUMA Features
1559506f1d07SSam Ravnborgconfig NUMA
1560e133f6eaSRandy Dunlap	bool "NUMA Memory Allocation and Scheduler Support"
1561506f1d07SSam Ravnborg	depends on SMP
1562b5660ba7SH. Peter Anvin	depends on X86_64 || (X86_32 && HIGHMEM64G && X86_BIGSMP)
1563b5660ba7SH. Peter Anvin	default y if X86_BIGSMP
15647ecd19cfSKefeng Wang	select USE_PERCPU_NUMA_NODE_ID
1565a7f7f624SMasahiro Yamada	help
1566e133f6eaSRandy Dunlap	  Enable NUMA (Non-Uniform Memory Access) support.
1567fd51b2d7SKOSAKI Motohiro
1568506f1d07SSam Ravnborg	  The kernel will try to allocate memory used by a CPU on the
1569506f1d07SSam Ravnborg	  local memory controller of the CPU and add some more
1570506f1d07SSam Ravnborg	  NUMA awareness to the kernel.
1571506f1d07SSam Ravnborg
1572c280ea5eSIngo Molnar	  For 64-bit this is recommended if the system is Intel Core i7
1573fd51b2d7SKOSAKI Motohiro	  (or later), AMD Opteron, or EM64T NUMA.
1574fd51b2d7SKOSAKI Motohiro
1575b5660ba7SH. Peter Anvin	  For 32-bit this is only needed if you boot a 32-bit
15767cf6c945SDavid Rientjes	  kernel on a 64-bit NUMA platform.
1577fd51b2d7SKOSAKI Motohiro
1578fd51b2d7SKOSAKI Motohiro	  Otherwise, you should say N.
1579506f1d07SSam Ravnborg
1580eec1d4faSHans Rosenfeldconfig AMD_NUMA
15813c2362e6SHarvey Harrison	def_bool y
15823c2362e6SHarvey Harrison	prompt "Old style AMD Opteron NUMA detection"
15835da0ef9aSTejun Heo	depends on X86_64 && NUMA && PCI
1584a7f7f624SMasahiro Yamada	help
1585eec1d4faSHans Rosenfeld	  Enable AMD NUMA node topology detection.  You should say Y here if
1586eec1d4faSHans Rosenfeld	  you have a multi processor AMD system. This uses an old method to
1587eec1d4faSHans Rosenfeld	  read the NUMA configuration directly from the builtin Northbridge
1588eec1d4faSHans Rosenfeld	  of Opteron. It is recommended to use X86_64_ACPI_NUMA instead,
1589eec1d4faSHans Rosenfeld	  which also takes priority if both are compiled in.
1590506f1d07SSam Ravnborg
1591506f1d07SSam Ravnborgconfig X86_64_ACPI_NUMA
15923c2362e6SHarvey Harrison	def_bool y
15933c2362e6SHarvey Harrison	prompt "ACPI NUMA detection"
1594506f1d07SSam Ravnborg	depends on X86_64 && NUMA && ACPI && PCI
1595506f1d07SSam Ravnborg	select ACPI_NUMA
1596a7f7f624SMasahiro Yamada	help
1597506f1d07SSam Ravnborg	  Enable ACPI SRAT based node topology detection.
1598506f1d07SSam Ravnborg
1599506f1d07SSam Ravnborgconfig NUMA_EMU
1600506f1d07SSam Ravnborg	bool "NUMA emulation"
16011b7e03efSTejun Heo	depends on NUMA
1602a7f7f624SMasahiro Yamada	help
1603506f1d07SSam Ravnborg	  Enable NUMA emulation. A flat machine will be split
1604506f1d07SSam Ravnborg	  into virtual nodes when booted with "numa=fake=N", where N is the
1605506f1d07SSam Ravnborg	  number of nodes. This is only useful for debugging.
1606506f1d07SSam Ravnborg
1607506f1d07SSam Ravnborgconfig NODES_SHIFT
1608d25e26b6SLinus Torvalds	int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP
160951591e31SDavid Rientjes	range 1 10
161051591e31SDavid Rientjes	default "10" if MAXSMP
1611506f1d07SSam Ravnborg	default "6" if X86_64
1612506f1d07SSam Ravnborg	default "3"
1613a9ee6cf5SMike Rapoport	depends on NUMA
1614a7f7f624SMasahiro Yamada	help
16151184dc2fSMike Travis	  Specify the maximum number of NUMA Nodes available on the target
1616692105b8SMatt LaPlante	  system.  Increases memory reserved to accommodate various tables.
1617506f1d07SSam Ravnborg
1618506f1d07SSam Ravnborgconfig ARCH_FLATMEM_ENABLE
1619506f1d07SSam Ravnborg	def_bool y
16203b16651fSTejun Heo	depends on X86_32 && !NUMA
1621506f1d07SSam Ravnborg
1622506f1d07SSam Ravnborgconfig ARCH_SPARSEMEM_ENABLE
1623506f1d07SSam Ravnborg	def_bool y
16246ea30386SKees Cook	depends on X86_64 || NUMA || X86_32 || X86_32_NON_STANDARD
1625506f1d07SSam Ravnborg	select SPARSEMEM_STATIC if X86_32
1626506f1d07SSam Ravnborg	select SPARSEMEM_VMEMMAP_ENABLE if X86_64
1627506f1d07SSam Ravnborg
16283b16651fSTejun Heoconfig ARCH_SPARSEMEM_DEFAULT
16296ad57f7fSMike Rapoport	def_bool X86_64 || (NUMA && X86_32)
16303b16651fSTejun Heo
1631506f1d07SSam Ravnborgconfig ARCH_SELECT_MEMORY_MODEL
1632506f1d07SSam Ravnborg	def_bool y
16334eda2bc3SDavid Hildenbrand	depends on ARCH_SPARSEMEM_ENABLE && ARCH_FLATMEM_ENABLE
1634506f1d07SSam Ravnborg
1635506f1d07SSam Ravnborgconfig ARCH_MEMORY_PROBE
1636a0842b70SToshi Kani	bool "Enable sysfs memory/probe interface"
16375c11f00bSDavid Hildenbrand	depends on MEMORY_HOTPLUG
1638a0842b70SToshi Kani	help
1639a0842b70SToshi Kani	  This option enables a sysfs memory/probe interface for testing.
1640cb1aaebeSMauro Carvalho Chehab	  See Documentation/admin-guide/mm/memory-hotplug.rst for more information.
1641a0842b70SToshi Kani	  If you are unsure how to answer this question, answer N.
1642506f1d07SSam Ravnborg
16433b16651fSTejun Heoconfig ARCH_PROC_KCORE_TEXT
16443b16651fSTejun Heo	def_bool y
16453b16651fSTejun Heo	depends on X86_64 && PROC_KCORE
16463b16651fSTejun Heo
1647a29815a3SAvi Kivityconfig ILLEGAL_POINTER_VALUE
1648a29815a3SAvi Kivity	hex
1649a29815a3SAvi Kivity	default 0 if X86_32
1650a29815a3SAvi Kivity	default 0xdead000000000000 if X86_64
1651a29815a3SAvi Kivity
16527a67832cSDan Williamsconfig X86_PMEM_LEGACY_DEVICE
16537a67832cSDan Williams	bool
16547a67832cSDan Williams
1655ec776ef6SChristoph Hellwigconfig X86_PMEM_LEGACY
16567a67832cSDan Williams	tristate "Support non-standard NVDIMMs and ADR protected memory"
16579f53f9faSDan Williams	depends on PHYS_ADDR_T_64BIT
16589f53f9faSDan Williams	depends on BLK_DEV
16597a67832cSDan Williams	select X86_PMEM_LEGACY_DEVICE
16607b27a862SDan Williams	select NUMA_KEEP_MEMINFO if NUMA
16619f53f9faSDan Williams	select LIBNVDIMM
1662ec776ef6SChristoph Hellwig	help
1663ec776ef6SChristoph Hellwig	  Treat memory marked using the non-standard e820 type of 12 as used
1664ec776ef6SChristoph Hellwig	  by the Intel Sandy Bridge-EP reference BIOS as protected memory.
1665ec776ef6SChristoph Hellwig	  The kernel will offer these regions to the 'pmem' driver so
1666ec776ef6SChristoph Hellwig	  they can be used for persistent storage.
1667ec776ef6SChristoph Hellwig
1668ec776ef6SChristoph Hellwig	  Say Y if unsure.
1669ec776ef6SChristoph Hellwig
1670506f1d07SSam Ravnborgconfig HIGHPTE
1671506f1d07SSam Ravnborg	bool "Allocate 3rd-level pagetables from highmem"
16726fc108a0SJan Beulich	depends on HIGHMEM
1673a7f7f624SMasahiro Yamada	help
1674506f1d07SSam Ravnborg	  The VM uses one page table entry for each page of physical memory.
1675506f1d07SSam Ravnborg	  For systems with a lot of RAM, this can be wasteful of precious
1676506f1d07SSam Ravnborg	  low memory.  Setting this option will put user-space page table
1677506f1d07SSam Ravnborg	  entries in high memory.
1678506f1d07SSam Ravnborg
16799f077871SJeremy Fitzhardingeconfig X86_CHECK_BIOS_CORRUPTION
16809f077871SJeremy Fitzhardinge	bool "Check for low memory corruption"
1681a7f7f624SMasahiro Yamada	help
16829f077871SJeremy Fitzhardinge	  Periodically check for memory corruption in low memory, which
16839f077871SJeremy Fitzhardinge	  is suspected to be caused by BIOS.  Even when enabled in the
16849f077871SJeremy Fitzhardinge	  configuration, it is disabled at runtime.  Enable it by
16859f077871SJeremy Fitzhardinge	  setting "memory_corruption_check=1" on the kernel command
16869f077871SJeremy Fitzhardinge	  line.  By default it scans the low 64k of memory every 60
16879f077871SJeremy Fitzhardinge	  seconds; see the memory_corruption_check_size and
16889f077871SJeremy Fitzhardinge	  memory_corruption_check_period parameters in
16898c27ceffSMauro Carvalho Chehab	  Documentation/admin-guide/kernel-parameters.rst to adjust this.
16909f077871SJeremy Fitzhardinge
16919f077871SJeremy Fitzhardinge	  When enabled with the default parameters, this option has
16929f077871SJeremy Fitzhardinge	  almost no overhead, as it reserves a relatively small amount
16939f077871SJeremy Fitzhardinge	  of memory and scans it infrequently.  It both detects corruption
16949f077871SJeremy Fitzhardinge	  and prevents it from affecting the running system.
16959f077871SJeremy Fitzhardinge
16969f077871SJeremy Fitzhardinge	  It is, however, intended as a diagnostic tool; if repeatable
16979f077871SJeremy Fitzhardinge	  BIOS-originated corruption always affects the same memory,
16989f077871SJeremy Fitzhardinge	  you can use memmap= to prevent the kernel from using that
16999f077871SJeremy Fitzhardinge	  memory.
17009f077871SJeremy Fitzhardinge
1701c885df50SJeremy Fitzhardingeconfig X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK
1702c885df50SJeremy Fitzhardinge	bool "Set the default setting of memory_corruption_check"
1703c885df50SJeremy Fitzhardinge	depends on X86_CHECK_BIOS_CORRUPTION
1704c885df50SJeremy Fitzhardinge	default y
1705a7f7f624SMasahiro Yamada	help
1706c885df50SJeremy Fitzhardinge	  Set whether the default state of memory_corruption_check is
1707c885df50SJeremy Fitzhardinge	  on or off.
1708c885df50SJeremy Fitzhardinge
1709506f1d07SSam Ravnborgconfig MATH_EMULATION
1710506f1d07SSam Ravnborg	bool
1711a5b9e5a2SAndy Lutomirski	depends on MODIFY_LDT_SYSCALL
171287d6021bSArnd Bergmann	prompt "Math emulation" if X86_32 && (M486SX || MELAN)
1713a7f7f624SMasahiro Yamada	help
1714506f1d07SSam Ravnborg	  Linux can emulate a math coprocessor (used for floating point
1715506f1d07SSam Ravnborg	  operations) if you don't have one. 486DX and Pentium processors have
1716506f1d07SSam Ravnborg	  a math coprocessor built in, 486SX and 386 do not, unless you added
1717506f1d07SSam Ravnborg	  a 487DX or 387, respectively. (The messages during boot time can
1718506f1d07SSam Ravnborg	  give you some hints here ["man dmesg"].) Everyone needs either a
1719506f1d07SSam Ravnborg	  coprocessor or this emulation.
1720506f1d07SSam Ravnborg
1721506f1d07SSam Ravnborg	  If you don't have a math coprocessor, you need to say Y here; if you
1722506f1d07SSam Ravnborg	  say Y here even though you have a coprocessor, the coprocessor will
1723506f1d07SSam Ravnborg	  be used nevertheless. (This behavior can be changed with the kernel
1724506f1d07SSam Ravnborg	  command line option "no387", which comes handy if your coprocessor
1725506f1d07SSam Ravnborg	  is broken. Try "man bootparam" or see the documentation of your boot
1726506f1d07SSam Ravnborg	  loader (lilo or loadlin) about how to pass options to the kernel at
1727506f1d07SSam Ravnborg	  boot time.) This means that it is a good idea to say Y here if you
1728506f1d07SSam Ravnborg	  intend to use this kernel on different machines.
1729506f1d07SSam Ravnborg
1730506f1d07SSam Ravnborg	  More information about the internals of the Linux math coprocessor
1731506f1d07SSam Ravnborg	  emulation can be found in <file:arch/x86/math-emu/README>.
1732506f1d07SSam Ravnborg
1733506f1d07SSam Ravnborg	  If you are not sure, say Y; apart from resulting in a 66 KB bigger
1734506f1d07SSam Ravnborg	  kernel, it won't hurt.
1735506f1d07SSam Ravnborg
1736506f1d07SSam Ravnborgconfig MTRR
17376fc108a0SJan Beulich	def_bool y
17386a108a14SDavid Rientjes	prompt "MTRR (Memory Type Range Register) support" if EXPERT
1739a7f7f624SMasahiro Yamada	help
1740506f1d07SSam Ravnborg	  On Intel P6 family processors (Pentium Pro, Pentium II and later)
1741506f1d07SSam Ravnborg	  the Memory Type Range Registers (MTRRs) may be used to control
1742506f1d07SSam Ravnborg	  processor access to memory ranges. This is most useful if you have
1743506f1d07SSam Ravnborg	  a video (VGA) card on a PCI or AGP bus. Enabling write-combining
1744506f1d07SSam Ravnborg	  allows bus write transfers to be combined into a larger transfer
1745506f1d07SSam Ravnborg	  before bursting over the PCI/AGP bus. This can increase performance
1746506f1d07SSam Ravnborg	  of image write operations 2.5 times or more. Saying Y here creates a
1747506f1d07SSam Ravnborg	  /proc/mtrr file which may be used to manipulate your processor's
1748506f1d07SSam Ravnborg	  MTRRs. Typically the X server should use this.
1749506f1d07SSam Ravnborg
1750506f1d07SSam Ravnborg	  This code has a reasonably generic interface so that similar
1751506f1d07SSam Ravnborg	  control registers on other processors can be easily supported
1752506f1d07SSam Ravnborg	  as well:
1753506f1d07SSam Ravnborg
1754506f1d07SSam Ravnborg	  The Cyrix 6x86, 6x86MX and M II processors have Address Range
1755506f1d07SSam Ravnborg	  Registers (ARRs) which provide a similar functionality to MTRRs. For
1756506f1d07SSam Ravnborg	  these, the ARRs are used to emulate the MTRRs.
1757506f1d07SSam Ravnborg	  The AMD K6-2 (stepping 8 and above) and K6-3 processors have two
1758506f1d07SSam Ravnborg	  MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing
1759506f1d07SSam Ravnborg	  write-combining. All of these processors are supported by this code
1760506f1d07SSam Ravnborg	  and it makes sense to say Y here if you have one of them.
1761506f1d07SSam Ravnborg
1762506f1d07SSam Ravnborg	  Saying Y here also fixes a problem with buggy SMP BIOSes which only
1763506f1d07SSam Ravnborg	  set the MTRRs for the boot CPU and not for the secondary CPUs. This
1764506f1d07SSam Ravnborg	  can lead to all sorts of problems, so it's good to say Y here.
1765506f1d07SSam Ravnborg
1766506f1d07SSam Ravnborg	  You can safely say Y even if your machine doesn't have MTRRs, you'll
1767506f1d07SSam Ravnborg	  just add about 9 KB to your kernel.
1768506f1d07SSam Ravnborg
1769cb1aaebeSMauro Carvalho Chehab	  See <file:Documentation/x86/mtrr.rst> for more information.
1770506f1d07SSam Ravnborg
177195ffa243SYinghai Luconfig MTRR_SANITIZER
17722ffb3501SYinghai Lu	def_bool y
177395ffa243SYinghai Lu	prompt "MTRR cleanup support"
177495ffa243SYinghai Lu	depends on MTRR
1775a7f7f624SMasahiro Yamada	help
1776aba3728cSThomas Gleixner	  Convert MTRR layout from continuous to discrete, so X drivers can
1777aba3728cSThomas Gleixner	  add writeback entries.
177895ffa243SYinghai Lu
1779aba3728cSThomas Gleixner	  Can be disabled with disable_mtrr_cleanup on the kernel command line.
1780692105b8SMatt LaPlante	  The largest mtrr entry size for a continuous block can be set with
1781aba3728cSThomas Gleixner	  mtrr_chunk_size.
178295ffa243SYinghai Lu
17832ffb3501SYinghai Lu	  If unsure, say Y.
178495ffa243SYinghai Lu
178595ffa243SYinghai Luconfig MTRR_SANITIZER_ENABLE_DEFAULT
1786f5098d62SYinghai Lu	int "MTRR cleanup enable value (0-1)"
1787f5098d62SYinghai Lu	range 0 1
1788f5098d62SYinghai Lu	default "0"
178995ffa243SYinghai Lu	depends on MTRR_SANITIZER
1790a7f7f624SMasahiro Yamada	help
1791f5098d62SYinghai Lu	  Enable mtrr cleanup default value
179295ffa243SYinghai Lu
179312031a62SYinghai Luconfig MTRR_SANITIZER_SPARE_REG_NR_DEFAULT
179412031a62SYinghai Lu	int "MTRR cleanup spare reg num (0-7)"
179512031a62SYinghai Lu	range 0 7
179612031a62SYinghai Lu	default "1"
179712031a62SYinghai Lu	depends on MTRR_SANITIZER
1798a7f7f624SMasahiro Yamada	help
179912031a62SYinghai Lu	  mtrr cleanup spare entries default, it can be changed via
1800aba3728cSThomas Gleixner	  mtrr_spare_reg_nr=N on the kernel command line.
180112031a62SYinghai Lu
18022e5d9c85Svenkatesh.pallipadi@intel.comconfig X86_PAT
18036fc108a0SJan Beulich	def_bool y
18046a108a14SDavid Rientjes	prompt "x86 PAT support" if EXPERT
18052a8a2719SIngo Molnar	depends on MTRR
1806a7f7f624SMasahiro Yamada	help
18072e5d9c85Svenkatesh.pallipadi@intel.com	  Use PAT attributes to setup page level cache control.
1808042b78e4SVenki Pallipadi
18092e5d9c85Svenkatesh.pallipadi@intel.com	  PATs are the modern equivalents of MTRRs and are much more
18102e5d9c85Svenkatesh.pallipadi@intel.com	  flexible than MTRRs.
18112e5d9c85Svenkatesh.pallipadi@intel.com
18122e5d9c85Svenkatesh.pallipadi@intel.com	  Say N here if you see bootup problems (boot crash, boot hang,
1813042b78e4SVenki Pallipadi	  spontaneous reboots) or a non-working video driver.
18142e5d9c85Svenkatesh.pallipadi@intel.com
18152e5d9c85Svenkatesh.pallipadi@intel.com	  If unsure, say Y.
18162e5d9c85Svenkatesh.pallipadi@intel.com
181746cf98cdSVenkatesh Pallipadiconfig ARCH_USES_PG_UNCACHED
181846cf98cdSVenkatesh Pallipadi	def_bool y
181946cf98cdSVenkatesh Pallipadi	depends on X86_PAT
182046cf98cdSVenkatesh Pallipadi
1821b971880fSBabu Mogerconfig X86_UMIP
1822796ebc81SRicardo Neri	def_bool y
1823b971880fSBabu Moger	prompt "User Mode Instruction Prevention" if EXPERT
1824a7f7f624SMasahiro Yamada	help
1825b971880fSBabu Moger	  User Mode Instruction Prevention (UMIP) is a security feature in
1826b971880fSBabu Moger	  some x86 processors. If enabled, a general protection fault is
1827b971880fSBabu Moger	  issued if the SGDT, SLDT, SIDT, SMSW or STR instructions are
1828b971880fSBabu Moger	  executed in user mode. These instructions unnecessarily expose
1829b971880fSBabu Moger	  information about the hardware state.
1830796ebc81SRicardo Neri
1831796ebc81SRicardo Neri	  The vast majority of applications do not use these instructions.
1832796ebc81SRicardo Neri	  For the very few that do, software emulation is provided in
1833796ebc81SRicardo Neri	  specific cases in protected and virtual-8086 modes. Emulated
1834796ebc81SRicardo Neri	  results are dummy.
1835aa35f896SRicardo Neri
1836156ff4a5SPeter Zijlstraconfig CC_HAS_IBT
1837156ff4a5SPeter Zijlstra	# GCC >= 9 and binutils >= 2.29
1838156ff4a5SPeter Zijlstra	# Retpoline check to work around https://gcc.gnu.org/bugzilla/show_bug.cgi?id=93654
1839156ff4a5SPeter Zijlstra	# Clang/LLVM >= 14
1840262448f3SNathan Chancellor	# https://github.com/llvm/llvm-project/commit/e0b89df2e0f0130881bf6c39bf31d7f6aac00e0f
1841262448f3SNathan Chancellor	# https://github.com/llvm/llvm-project/commit/dfcf69770bc522b9e411c66454934a37c1f35332
1842156ff4a5SPeter Zijlstra	def_bool ((CC_IS_GCC && $(cc-option, -fcf-protection=branch -mindirect-branch-register)) || \
1843262448f3SNathan Chancellor		  (CC_IS_CLANG && CLANG_VERSION >= 140000)) && \
1844156ff4a5SPeter Zijlstra		  $(as-instr,endbr64)
1845156ff4a5SPeter Zijlstra
1846156ff4a5SPeter Zijlstraconfig X86_KERNEL_IBT
1847156ff4a5SPeter Zijlstra	prompt "Indirect Branch Tracking"
1848156ff4a5SPeter Zijlstra	bool
184903f16cd0SJosh Poimboeuf	depends on X86_64 && CC_HAS_IBT && HAVE_OBJTOOL
1850f6a2c2b2SNathan Chancellor	# https://github.com/llvm/llvm-project/commit/9d7001eba9c4cb311e03cd8cdc231f9e579f2d0f
1851f6a2c2b2SNathan Chancellor	depends on !LD_IS_LLD || LLD_VERSION >= 140000
185203f16cd0SJosh Poimboeuf	select OBJTOOL
1853156ff4a5SPeter Zijlstra	help
1854156ff4a5SPeter Zijlstra	  Build the kernel with support for Indirect Branch Tracking, a
1855156ff4a5SPeter Zijlstra	  hardware support course-grain forward-edge Control Flow Integrity
1856156ff4a5SPeter Zijlstra	  protection. It enforces that all indirect calls must land on
1857156ff4a5SPeter Zijlstra	  an ENDBR instruction, as such, the compiler will instrument the
1858156ff4a5SPeter Zijlstra	  code with them to make this happen.
1859156ff4a5SPeter Zijlstra
1860ed53a0d9SPeter Zijlstra	  In addition to building the kernel with IBT, seal all functions that
18614cdfc11bSNur Hussein	  are not indirect call targets, avoiding them ever becoming one.
1862ed53a0d9SPeter Zijlstra
1863ed53a0d9SPeter Zijlstra	  This requires LTO like objtool runs and will slow down the build. It
1864ed53a0d9SPeter Zijlstra	  does significantly reduce the number of ENDBR instructions in the
1865ed53a0d9SPeter Zijlstra	  kernel image.
1866ed53a0d9SPeter Zijlstra
186735e97790SDave Hansenconfig X86_INTEL_MEMORY_PROTECTION_KEYS
186838f3e775SBabu Moger	prompt "Memory Protection Keys"
186935e97790SDave Hansen	def_bool y
1870284244a9SDave Hansen	# Note: only available in 64-bit mode
187138f3e775SBabu Moger	depends on X86_64 && (CPU_SUP_INTEL || CPU_SUP_AMD)
187252c8e601SIngo Molnar	select ARCH_USES_HIGH_VMA_FLAGS
187352c8e601SIngo Molnar	select ARCH_HAS_PKEYS
1874a7f7f624SMasahiro Yamada	help
1875284244a9SDave Hansen	  Memory Protection Keys provides a mechanism for enforcing
1876284244a9SDave Hansen	  page-based protections, but without requiring modification of the
1877284244a9SDave Hansen	  page tables when an application changes protection domains.
1878284244a9SDave Hansen
18791eecbcdcSMauro Carvalho Chehab	  For details, see Documentation/core-api/protection-keys.rst
1880284244a9SDave Hansen
1881284244a9SDave Hansen	  If unsure, say y.
188235e97790SDave Hansen
1883db616173SMichal Hockochoice
1884db616173SMichal Hocko	prompt "TSX enable mode"
1885db616173SMichal Hocko	depends on CPU_SUP_INTEL
1886db616173SMichal Hocko	default X86_INTEL_TSX_MODE_OFF
1887db616173SMichal Hocko	help
1888db616173SMichal Hocko	  Intel's TSX (Transactional Synchronization Extensions) feature
1889db616173SMichal Hocko	  allows to optimize locking protocols through lock elision which
1890db616173SMichal Hocko	  can lead to a noticeable performance boost.
1891db616173SMichal Hocko
1892db616173SMichal Hocko	  On the other hand it has been shown that TSX can be exploited
1893db616173SMichal Hocko	  to form side channel attacks (e.g. TAA) and chances are there
1894db616173SMichal Hocko	  will be more of those attacks discovered in the future.
1895db616173SMichal Hocko
1896db616173SMichal Hocko	  Therefore TSX is not enabled by default (aka tsx=off). An admin
1897db616173SMichal Hocko	  might override this decision by tsx=on the command line parameter.
1898db616173SMichal Hocko	  Even with TSX enabled, the kernel will attempt to enable the best
1899db616173SMichal Hocko	  possible TAA mitigation setting depending on the microcode available
1900db616173SMichal Hocko	  for the particular machine.
1901db616173SMichal Hocko
1902db616173SMichal Hocko	  This option allows to set the default tsx mode between tsx=on, =off
1903db616173SMichal Hocko	  and =auto. See Documentation/admin-guide/kernel-parameters.txt for more
1904db616173SMichal Hocko	  details.
1905db616173SMichal Hocko
1906db616173SMichal Hocko	  Say off if not sure, auto if TSX is in use but it should be used on safe
1907db616173SMichal Hocko	  platforms or on if TSX is in use and the security aspect of tsx is not
1908db616173SMichal Hocko	  relevant.
1909db616173SMichal Hocko
1910db616173SMichal Hockoconfig X86_INTEL_TSX_MODE_OFF
1911db616173SMichal Hocko	bool "off"
1912db616173SMichal Hocko	help
1913db616173SMichal Hocko	  TSX is disabled if possible - equals to tsx=off command line parameter.
1914db616173SMichal Hocko
1915db616173SMichal Hockoconfig X86_INTEL_TSX_MODE_ON
1916db616173SMichal Hocko	bool "on"
1917db616173SMichal Hocko	help
1918db616173SMichal Hocko	  TSX is always enabled on TSX capable HW - equals the tsx=on command
1919db616173SMichal Hocko	  line parameter.
1920db616173SMichal Hocko
1921db616173SMichal Hockoconfig X86_INTEL_TSX_MODE_AUTO
1922db616173SMichal Hocko	bool "auto"
1923db616173SMichal Hocko	help
1924db616173SMichal Hocko	  TSX is enabled on TSX capable HW that is believed to be safe against
1925db616173SMichal Hocko	  side channel attacks- equals the tsx=auto command line parameter.
1926db616173SMichal Hockoendchoice
1927db616173SMichal Hocko
1928e7e05452SSean Christophersonconfig X86_SGX
1929e7e05452SSean Christopherson	bool "Software Guard eXtensions (SGX)"
1930e7e05452SSean Christopherson	depends on X86_64 && CPU_SUP_INTEL
1931e7e05452SSean Christopherson	depends on CRYPTO=y
1932e7e05452SSean Christopherson	depends on CRYPTO_SHA256=y
1933e7e05452SSean Christopherson	select SRCU
1934e7e05452SSean Christopherson	select MMU_NOTIFIER
1935901ddbb9SJarkko Sakkinen	select NUMA_KEEP_MEMINFO if NUMA
193640e0e784STony Luck	select XARRAY_MULTI
1937e7e05452SSean Christopherson	help
1938e7e05452SSean Christopherson	  Intel(R) Software Guard eXtensions (SGX) is a set of CPU instructions
1939e7e05452SSean Christopherson	  that can be used by applications to set aside private regions of code
1940e7e05452SSean Christopherson	  and data, referred to as enclaves. An enclave's private memory can
1941e7e05452SSean Christopherson	  only be accessed by code running within the enclave. Accesses from
1942e7e05452SSean Christopherson	  outside the enclave, including other enclaves, are disallowed by
1943e7e05452SSean Christopherson	  hardware.
1944e7e05452SSean Christopherson
1945e7e05452SSean Christopherson	  If unsure, say N.
1946e7e05452SSean Christopherson
1947506f1d07SSam Ravnborgconfig EFI
19489ba16087SJan Beulich	bool "EFI runtime service support"
19495b83683fSHuang, Ying	depends on ACPI
1950f6ce5002SSergey Vlasov	select UCS2_STRING
1951022ee6c5SArd Biesheuvel	select EFI_RUNTIME_WRAPPERS
19521ff2fc02STom Lendacky	select ARCH_USE_MEMREMAP_PROT
1953a7f7f624SMasahiro Yamada	help
19548b2cb7a8SHuang, Ying	  This enables the kernel to use EFI runtime services that are
1955506f1d07SSam Ravnborg	  available (such as the EFI variable services).
1956506f1d07SSam Ravnborg
19578b2cb7a8SHuang, Ying	  This option is only useful on systems that have EFI firmware.
19588b2cb7a8SHuang, Ying	  In addition, you should use the latest ELILO loader available
19598b2cb7a8SHuang, Ying	  at <http://elilo.sourceforge.net> in order to take advantage
19608b2cb7a8SHuang, Ying	  of EFI runtime services. However, even with this option, the
19618b2cb7a8SHuang, Ying	  resultant kernel should continue to boot on existing non-EFI
19628b2cb7a8SHuang, Ying	  platforms.
1963506f1d07SSam Ravnborg
1964291f3632SMatt Flemingconfig EFI_STUB
1965291f3632SMatt Fleming	bool "EFI stub support"
1966c6dbd3e5SPeter Zijlstra	depends on EFI
19678f24f8c2SArd Biesheuvel	depends on $(cc-option,-mabi=ms) || X86_32
19687b2a583aSMatt Fleming	select RELOCATABLE
1969a7f7f624SMasahiro Yamada	help
1970291f3632SMatt Fleming	  This kernel feature allows a bzImage to be loaded directly
1971291f3632SMatt Fleming	  by EFI firmware without the use of a bootloader.
1972291f3632SMatt Fleming
19734f4cfa6cSMauro Carvalho Chehab	  See Documentation/admin-guide/efi-stub.rst for more information.
19740c759662SMatt Fleming
19757d453eeeSMatt Flemingconfig EFI_MIXED
19767d453eeeSMatt Fleming	bool "EFI mixed-mode support"
19777d453eeeSMatt Fleming	depends on EFI_STUB && X86_64
1978a7f7f624SMasahiro Yamada	help
19797d453eeeSMatt Fleming	  Enabling this feature allows a 64-bit kernel to be booted
19807d453eeeSMatt Fleming	  on a 32-bit firmware, provided that your CPU supports 64-bit
19817d453eeeSMatt Fleming	  mode.
19827d453eeeSMatt Fleming
19837d453eeeSMatt Fleming	  Note that it is not possible to boot a mixed-mode enabled
19847d453eeeSMatt Fleming	  kernel via the EFI boot stub - a bootloader that supports
19857d453eeeSMatt Fleming	  the EFI handover protocol must be used.
19867d453eeeSMatt Fleming
19877d453eeeSMatt Fleming	  If unsure, say N.
19887d453eeeSMatt Fleming
19898636a1f9SMasahiro Yamadasource "kernel/Kconfig.hz"
1990506f1d07SSam Ravnborg
1991506f1d07SSam Ravnborgconfig KEXEC
1992506f1d07SSam Ravnborg	bool "kexec system call"
19932965faa5SDave Young	select KEXEC_CORE
1994a7f7f624SMasahiro Yamada	help
1995506f1d07SSam Ravnborg	  kexec is a system call that implements the ability to shutdown your
1996506f1d07SSam Ravnborg	  current kernel, and to start another kernel.  It is like a reboot
1997506f1d07SSam Ravnborg	  but it is independent of the system firmware.   And like a reboot
1998506f1d07SSam Ravnborg	  you can start any kernel with it, not just Linux.
1999506f1d07SSam Ravnborg
2000506f1d07SSam Ravnborg	  The name comes from the similarity to the exec system call.
2001506f1d07SSam Ravnborg
2002506f1d07SSam Ravnborg	  It is an ongoing process to be certain the hardware in a machine
2003506f1d07SSam Ravnborg	  is properly shutdown, so do not be surprised if this code does not
2004bf220695SGeert Uytterhoeven	  initially work for you.  As of this writing the exact hardware
2005bf220695SGeert Uytterhoeven	  interface is strongly in flux, so no good recommendation can be
2006bf220695SGeert Uytterhoeven	  made.
2007506f1d07SSam Ravnborg
200874ca317cSVivek Goyalconfig KEXEC_FILE
200974ca317cSVivek Goyal	bool "kexec file based system call"
20102965faa5SDave Young	select KEXEC_CORE
2011b69a2afdSJonathan McDowell	select HAVE_IMA_KEXEC if IMA
201274ca317cSVivek Goyal	depends on X86_64
201374ca317cSVivek Goyal	depends on CRYPTO=y
201474ca317cSVivek Goyal	depends on CRYPTO_SHA256=y
2015a7f7f624SMasahiro Yamada	help
201674ca317cSVivek Goyal	  This is new version of kexec system call. This system call is
201774ca317cSVivek Goyal	  file based and takes file descriptors as system call argument
201874ca317cSVivek Goyal	  for kernel and initramfs as opposed to list of segments as
201974ca317cSVivek Goyal	  accepted by previous system call.
202074ca317cSVivek Goyal
2021b799a09fSAKASHI Takahiroconfig ARCH_HAS_KEXEC_PURGATORY
2022b799a09fSAKASHI Takahiro	def_bool KEXEC_FILE
2023b799a09fSAKASHI Takahiro
202499d5cadfSJiri Bohacconfig KEXEC_SIG
20258e7d8381SVivek Goyal	bool "Verify kernel signature during kexec_file_load() syscall"
202674ca317cSVivek Goyal	depends on KEXEC_FILE
2027a7f7f624SMasahiro Yamada	help
202899d5cadfSJiri Bohac
202999d5cadfSJiri Bohac	  This option makes the kexec_file_load() syscall check for a valid
203099d5cadfSJiri Bohac	  signature of the kernel image.  The image can still be loaded without
203199d5cadfSJiri Bohac	  a valid signature unless you also enable KEXEC_SIG_FORCE, though if
203299d5cadfSJiri Bohac	  there's a signature that we can check, then it must be valid.
203399d5cadfSJiri Bohac
203499d5cadfSJiri Bohac	  In addition to this option, you need to enable signature
203599d5cadfSJiri Bohac	  verification for the corresponding kernel image type being
203699d5cadfSJiri Bohac	  loaded in order for this to work.
203799d5cadfSJiri Bohac
203899d5cadfSJiri Bohacconfig KEXEC_SIG_FORCE
203999d5cadfSJiri Bohac	bool "Require a valid signature in kexec_file_load() syscall"
204099d5cadfSJiri Bohac	depends on KEXEC_SIG
2041a7f7f624SMasahiro Yamada	help
20428e7d8381SVivek Goyal	  This option makes kernel signature verification mandatory for
2043d8eb8940SBorislav Petkov	  the kexec_file_load() syscall.
20448e7d8381SVivek Goyal
20458e7d8381SVivek Goyalconfig KEXEC_BZIMAGE_VERIFY_SIG
20468e7d8381SVivek Goyal	bool "Enable bzImage signature verification support"
204799d5cadfSJiri Bohac	depends on KEXEC_SIG
20488e7d8381SVivek Goyal	depends on SIGNED_PE_FILE_VERIFICATION
20498e7d8381SVivek Goyal	select SYSTEM_TRUSTED_KEYRING
2050a7f7f624SMasahiro Yamada	help
20518e7d8381SVivek Goyal	  Enable bzImage signature verification support.
20528e7d8381SVivek Goyal
2053506f1d07SSam Ravnborgconfig CRASH_DUMP
205404b69447SPavel Machek	bool "kernel crash dumps"
2055506f1d07SSam Ravnborg	depends on X86_64 || (X86_32 && HIGHMEM)
2056a7f7f624SMasahiro Yamada	help
2057506f1d07SSam Ravnborg	  Generate crash dump after being started by kexec.
2058506f1d07SSam Ravnborg	  This should be normally only set in special crash dump kernels
2059506f1d07SSam Ravnborg	  which are loaded in the main kernel with kexec-tools into
2060506f1d07SSam Ravnborg	  a specially reserved region and then later executed after
2061506f1d07SSam Ravnborg	  a crash by kdump/kexec. The crash dump kernel must be compiled
2062506f1d07SSam Ravnborg	  to a memory address not used by the main kernel or BIOS using
2063506f1d07SSam Ravnborg	  PHYSICAL_START, or it must be built as a relocatable image
2064506f1d07SSam Ravnborg	  (CONFIG_RELOCATABLE=y).
2065330d4810SMauro Carvalho Chehab	  For more details see Documentation/admin-guide/kdump/kdump.rst
2066506f1d07SSam Ravnborg
20673ab83521SHuang Yingconfig KEXEC_JUMP
20686ea30386SKees Cook	bool "kexec jump"
2069fee7b0d8SHuang Ying	depends on KEXEC && HIBERNATION
2070a7f7f624SMasahiro Yamada	help
207189081d17SHuang Ying	  Jump between original kernel and kexeced kernel and invoke
207289081d17SHuang Ying	  code in physical address mode via KEXEC
20733ab83521SHuang Ying
2074506f1d07SSam Ravnborgconfig PHYSICAL_START
20756a108a14SDavid Rientjes	hex "Physical address where the kernel is loaded" if (EXPERT || CRASH_DUMP)
2076ceefccc9SH. Peter Anvin	default "0x1000000"
2077a7f7f624SMasahiro Yamada	help
2078506f1d07SSam Ravnborg	  This gives the physical address where the kernel is loaded.
2079506f1d07SSam Ravnborg
2080506f1d07SSam Ravnborg	  If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then
2081506f1d07SSam Ravnborg	  bzImage will decompress itself to above physical address and
2082506f1d07SSam Ravnborg	  run from there. Otherwise, bzImage will run from the address where
2083506f1d07SSam Ravnborg	  it has been loaded by the boot loader and will ignore above physical
2084506f1d07SSam Ravnborg	  address.
2085506f1d07SSam Ravnborg
2086506f1d07SSam Ravnborg	  In normal kdump cases one does not have to set/change this option
2087506f1d07SSam Ravnborg	  as now bzImage can be compiled as a completely relocatable image
2088506f1d07SSam Ravnborg	  (CONFIG_RELOCATABLE=y) and be used to load and run from a different
2089506f1d07SSam Ravnborg	  address. This option is mainly useful for the folks who don't want
2090506f1d07SSam Ravnborg	  to use a bzImage for capturing the crash dump and want to use a
2091506f1d07SSam Ravnborg	  vmlinux instead. vmlinux is not relocatable hence a kernel needs
2092506f1d07SSam Ravnborg	  to be specifically compiled to run from a specific memory area
2093506f1d07SSam Ravnborg	  (normally a reserved region) and this option comes handy.
2094506f1d07SSam Ravnborg
2095ceefccc9SH. Peter Anvin	  So if you are using bzImage for capturing the crash dump,
2096ceefccc9SH. Peter Anvin	  leave the value here unchanged to 0x1000000 and set
2097ceefccc9SH. Peter Anvin	  CONFIG_RELOCATABLE=y.  Otherwise if you plan to use vmlinux
2098ceefccc9SH. Peter Anvin	  for capturing the crash dump change this value to start of
2099ceefccc9SH. Peter Anvin	  the reserved region.  In other words, it can be set based on
2100ceefccc9SH. Peter Anvin	  the "X" value as specified in the "crashkernel=YM@XM"
2101ceefccc9SH. Peter Anvin	  command line boot parameter passed to the panic-ed
2102330d4810SMauro Carvalho Chehab	  kernel. Please take a look at Documentation/admin-guide/kdump/kdump.rst
2103ceefccc9SH. Peter Anvin	  for more details about crash dumps.
2104506f1d07SSam Ravnborg
2105506f1d07SSam Ravnborg	  Usage of bzImage for capturing the crash dump is recommended as
2106506f1d07SSam Ravnborg	  one does not have to build two kernels. Same kernel can be used
2107506f1d07SSam Ravnborg	  as production kernel and capture kernel. Above option should have
2108506f1d07SSam Ravnborg	  gone away after relocatable bzImage support is introduced. But it
2109506f1d07SSam Ravnborg	  is present because there are users out there who continue to use
2110506f1d07SSam Ravnborg	  vmlinux for dump capture. This option should go away down the
2111506f1d07SSam Ravnborg	  line.
2112506f1d07SSam Ravnborg
2113506f1d07SSam Ravnborg	  Don't change this unless you know what you are doing.
2114506f1d07SSam Ravnborg
2115506f1d07SSam Ravnborgconfig RELOCATABLE
211626717808SH. Peter Anvin	bool "Build a relocatable kernel"
211726717808SH. Peter Anvin	default y
2118a7f7f624SMasahiro Yamada	help
2119506f1d07SSam Ravnborg	  This builds a kernel image that retains relocation information
2120506f1d07SSam Ravnborg	  so it can be loaded someplace besides the default 1MB.
2121506f1d07SSam Ravnborg	  The relocations tend to make the kernel binary about 10% larger,
2122506f1d07SSam Ravnborg	  but are discarded at runtime.
2123506f1d07SSam Ravnborg
2124506f1d07SSam Ravnborg	  One use is for the kexec on panic case where the recovery kernel
2125506f1d07SSam Ravnborg	  must live at a different physical address than the primary
2126506f1d07SSam Ravnborg	  kernel.
2127506f1d07SSam Ravnborg
2128506f1d07SSam Ravnborg	  Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address
2129506f1d07SSam Ravnborg	  it has been loaded at and the compile time physical address
21308ab3820fSKees Cook	  (CONFIG_PHYSICAL_START) is used as the minimum location.
2131506f1d07SSam Ravnborg
21328ab3820fSKees Cookconfig RANDOMIZE_BASE
2133e8581e3dSBaoquan He	bool "Randomize the address of the kernel image (KASLR)"
21348ab3820fSKees Cook	depends on RELOCATABLE
21356807c846SIngo Molnar	default y
2136a7f7f624SMasahiro Yamada	help
2137e8581e3dSBaoquan He	  In support of Kernel Address Space Layout Randomization (KASLR),
2138e8581e3dSBaoquan He	  this randomizes the physical address at which the kernel image
2139e8581e3dSBaoquan He	  is decompressed and the virtual address where the kernel
2140e8581e3dSBaoquan He	  image is mapped, as a security feature that deters exploit
2141e8581e3dSBaoquan He	  attempts relying on knowledge of the location of kernel
2142e8581e3dSBaoquan He	  code internals.
2143e8581e3dSBaoquan He
2144ed9f007eSKees Cook	  On 64-bit, the kernel physical and virtual addresses are
2145ed9f007eSKees Cook	  randomized separately. The physical address will be anywhere
2146ed9f007eSKees Cook	  between 16MB and the top of physical memory (up to 64TB). The
2147ed9f007eSKees Cook	  virtual address will be randomized from 16MB up to 1GB (9 bits
2148ed9f007eSKees Cook	  of entropy). Note that this also reduces the memory space
2149ed9f007eSKees Cook	  available to kernel modules from 1.5GB to 1GB.
2150ed9f007eSKees Cook
2151ed9f007eSKees Cook	  On 32-bit, the kernel physical and virtual addresses are
2152ed9f007eSKees Cook	  randomized together. They will be randomized from 16MB up to
2153ed9f007eSKees Cook	  512MB (8 bits of entropy).
21548ab3820fSKees Cook
2155a653f356SKees Cook	  Entropy is generated using the RDRAND instruction if it is
2156e8581e3dSBaoquan He	  supported. If RDTSC is supported, its value is mixed into
2157e8581e3dSBaoquan He	  the entropy pool as well. If neither RDRAND nor RDTSC are
2158ed9f007eSKees Cook	  supported, then entropy is read from the i8254 timer. The
2159ed9f007eSKees Cook	  usable entropy is limited by the kernel being built using
2160ed9f007eSKees Cook	  2GB addressing, and that PHYSICAL_ALIGN must be at a
2161ed9f007eSKees Cook	  minimum of 2MB. As a result, only 10 bits of entropy are
2162ed9f007eSKees Cook	  theoretically possible, but the implementations are further
2163ed9f007eSKees Cook	  limited due to memory layouts.
2164e8581e3dSBaoquan He
21656807c846SIngo Molnar	  If unsure, say Y.
2166da2b6fb9SKees Cook
21678ab3820fSKees Cook# Relocation on x86 needs some additional build support
2168845adf72SH. Peter Anvinconfig X86_NEED_RELOCS
2169845adf72SH. Peter Anvin	def_bool y
21708ab3820fSKees Cook	depends on RANDOMIZE_BASE || (X86_32 && RELOCATABLE)
2171845adf72SH. Peter Anvin
2172506f1d07SSam Ravnborgconfig PHYSICAL_ALIGN
2173a0215061SKees Cook	hex "Alignment value to which kernel should be aligned"
21748ab3820fSKees Cook	default "0x200000"
2175a0215061SKees Cook	range 0x2000 0x1000000 if X86_32
2176a0215061SKees Cook	range 0x200000 0x1000000 if X86_64
2177a7f7f624SMasahiro Yamada	help
2178506f1d07SSam Ravnborg	  This value puts the alignment restrictions on physical address
2179506f1d07SSam Ravnborg	  where kernel is loaded and run from. Kernel is compiled for an
2180506f1d07SSam Ravnborg	  address which meets above alignment restriction.
2181506f1d07SSam Ravnborg
2182506f1d07SSam Ravnborg	  If bootloader loads the kernel at a non-aligned address and
2183506f1d07SSam Ravnborg	  CONFIG_RELOCATABLE is set, kernel will move itself to nearest
2184506f1d07SSam Ravnborg	  address aligned to above value and run from there.
2185506f1d07SSam Ravnborg
2186506f1d07SSam Ravnborg	  If bootloader loads the kernel at a non-aligned address and
2187506f1d07SSam Ravnborg	  CONFIG_RELOCATABLE is not set, kernel will ignore the run time
2188506f1d07SSam Ravnborg	  load address and decompress itself to the address it has been
2189506f1d07SSam Ravnborg	  compiled for and run from there. The address for which kernel is
2190506f1d07SSam Ravnborg	  compiled already meets above alignment restrictions. Hence the
2191506f1d07SSam Ravnborg	  end result is that kernel runs from a physical address meeting
2192506f1d07SSam Ravnborg	  above alignment restrictions.
2193506f1d07SSam Ravnborg
2194a0215061SKees Cook	  On 32-bit this value must be a multiple of 0x2000. On 64-bit
2195a0215061SKees Cook	  this value must be a multiple of 0x200000.
2196a0215061SKees Cook
2197506f1d07SSam Ravnborg	  Don't change this unless you know what you are doing.
2198506f1d07SSam Ravnborg
2199eedb92abSKirill A. Shutemovconfig DYNAMIC_MEMORY_LAYOUT
2200eedb92abSKirill A. Shutemov	bool
2201a7f7f624SMasahiro Yamada	help
2202eedb92abSKirill A. Shutemov	  This option makes base addresses of vmalloc and vmemmap as well as
2203eedb92abSKirill A. Shutemov	  __PAGE_OFFSET movable during boot.
2204eedb92abSKirill A. Shutemov
22050483e1faSThomas Garnierconfig RANDOMIZE_MEMORY
22060483e1faSThomas Garnier	bool "Randomize the kernel memory sections"
22070483e1faSThomas Garnier	depends on X86_64
22080483e1faSThomas Garnier	depends on RANDOMIZE_BASE
2209eedb92abSKirill A. Shutemov	select DYNAMIC_MEMORY_LAYOUT
22100483e1faSThomas Garnier	default RANDOMIZE_BASE
2211a7f7f624SMasahiro Yamada	help
22120483e1faSThomas Garnier	  Randomizes the base virtual address of kernel memory sections
22130483e1faSThomas Garnier	  (physical memory mapping, vmalloc & vmemmap). This security feature
22140483e1faSThomas Garnier	  makes exploits relying on predictable memory locations less reliable.
22150483e1faSThomas Garnier
22160483e1faSThomas Garnier	  The order of allocations remains unchanged. Entropy is generated in
22170483e1faSThomas Garnier	  the same way as RANDOMIZE_BASE. Current implementation in the optimal
22180483e1faSThomas Garnier	  configuration have in average 30,000 different possible virtual
22190483e1faSThomas Garnier	  addresses for each memory section.
22200483e1faSThomas Garnier
22216807c846SIngo Molnar	  If unsure, say Y.
22220483e1faSThomas Garnier
222390397a41SThomas Garnierconfig RANDOMIZE_MEMORY_PHYSICAL_PADDING
222490397a41SThomas Garnier	hex "Physical memory mapping padding" if EXPERT
222590397a41SThomas Garnier	depends on RANDOMIZE_MEMORY
222690397a41SThomas Garnier	default "0xa" if MEMORY_HOTPLUG
222790397a41SThomas Garnier	default "0x0"
222890397a41SThomas Garnier	range 0x1 0x40 if MEMORY_HOTPLUG
222990397a41SThomas Garnier	range 0x0 0x40
2230a7f7f624SMasahiro Yamada	help
223190397a41SThomas Garnier	  Define the padding in terabytes added to the existing physical
223290397a41SThomas Garnier	  memory size during kernel memory randomization. It is useful
223390397a41SThomas Garnier	  for memory hotplug support but reduces the entropy available for
223490397a41SThomas Garnier	  address randomization.
223590397a41SThomas Garnier
223690397a41SThomas Garnier	  If unsure, leave at the default value.
223790397a41SThomas Garnier
2238506f1d07SSam Ravnborgconfig HOTPLUG_CPU
2239bebd024eSThomas Gleixner	def_bool y
224040b31360SStephen Rothwell	depends on SMP
2241506f1d07SSam Ravnborg
224280aa1dffSFenghua Yuconfig BOOTPARAM_HOTPLUG_CPU0
224380aa1dffSFenghua Yu	bool "Set default setting of cpu0_hotpluggable"
22442c922cd0SKees Cook	depends on HOTPLUG_CPU
2245a7f7f624SMasahiro Yamada	help
224680aa1dffSFenghua Yu	  Set whether default state of cpu0_hotpluggable is on or off.
224780aa1dffSFenghua Yu
224880aa1dffSFenghua Yu	  Say Y here to enable CPU0 hotplug by default. If this switch
224980aa1dffSFenghua Yu	  is turned on, there is no need to give cpu0_hotplug kernel
225080aa1dffSFenghua Yu	  parameter and the CPU0 hotplug feature is enabled by default.
225180aa1dffSFenghua Yu
225280aa1dffSFenghua Yu	  Please note: there are two known CPU0 dependencies if you want
225380aa1dffSFenghua Yu	  to enable the CPU0 hotplug feature either by this switch or by
225480aa1dffSFenghua Yu	  cpu0_hotplug kernel parameter.
225580aa1dffSFenghua Yu
225680aa1dffSFenghua Yu	  First, resume from hibernate or suspend always starts from CPU0.
225780aa1dffSFenghua Yu	  So hibernate and suspend are prevented if CPU0 is offline.
225880aa1dffSFenghua Yu
225980aa1dffSFenghua Yu	  Second dependency is PIC interrupts always go to CPU0. CPU0 can not
226080aa1dffSFenghua Yu	  offline if any interrupt can not migrate out of CPU0. There may
226180aa1dffSFenghua Yu	  be other CPU0 dependencies.
226280aa1dffSFenghua Yu
226380aa1dffSFenghua Yu	  Please make sure the dependencies are under your control before
226480aa1dffSFenghua Yu	  you enable this feature.
226580aa1dffSFenghua Yu
226680aa1dffSFenghua Yu	  Say N if you don't want to enable CPU0 hotplug feature by default.
226780aa1dffSFenghua Yu	  You still can enable the CPU0 hotplug feature at boot by kernel
226880aa1dffSFenghua Yu	  parameter cpu0_hotplug.
226980aa1dffSFenghua Yu
2270a71c8bc5SFenghua Yuconfig DEBUG_HOTPLUG_CPU0
2271a71c8bc5SFenghua Yu	def_bool n
2272a71c8bc5SFenghua Yu	prompt "Debug CPU0 hotplug"
22732c922cd0SKees Cook	depends on HOTPLUG_CPU
2274a7f7f624SMasahiro Yamada	help
2275a71c8bc5SFenghua Yu	  Enabling this option offlines CPU0 (if CPU0 can be offlined) as
2276a71c8bc5SFenghua Yu	  soon as possible and boots up userspace with CPU0 offlined. User
2277a71c8bc5SFenghua Yu	  can online CPU0 back after boot time.
2278a71c8bc5SFenghua Yu
2279a71c8bc5SFenghua Yu	  To debug CPU0 hotplug, you need to enable CPU0 offline/online
2280a71c8bc5SFenghua Yu	  feature by either turning on CONFIG_BOOTPARAM_HOTPLUG_CPU0 during
2281a71c8bc5SFenghua Yu	  compilation or giving cpu0_hotplug kernel parameter at boot.
2282a71c8bc5SFenghua Yu
2283a71c8bc5SFenghua Yu	  If unsure, say N.
2284a71c8bc5SFenghua Yu
2285506f1d07SSam Ravnborgconfig COMPAT_VDSO
2286b0b49f26SAndy Lutomirski	def_bool n
2287b0b49f26SAndy Lutomirski	prompt "Disable the 32-bit vDSO (needed for glibc 2.3.3)"
2288953fee1dSIngo Molnar	depends on COMPAT_32
2289a7f7f624SMasahiro Yamada	help
2290b0b49f26SAndy Lutomirski	  Certain buggy versions of glibc will crash if they are
2291b0b49f26SAndy Lutomirski	  presented with a 32-bit vDSO that is not mapped at the address
2292b0b49f26SAndy Lutomirski	  indicated in its segment table.
2293e84446deSRandy Dunlap
2294b0b49f26SAndy Lutomirski	  The bug was introduced by f866314b89d56845f55e6f365e18b31ec978ec3a
2295b0b49f26SAndy Lutomirski	  and fixed by 3b3ddb4f7db98ec9e912ccdf54d35df4aa30e04a and
2296b0b49f26SAndy Lutomirski	  49ad572a70b8aeb91e57483a11dd1b77e31c4468.  Glibc 2.3.3 is
2297b0b49f26SAndy Lutomirski	  the only released version with the bug, but OpenSUSE 9
2298b0b49f26SAndy Lutomirski	  contains a buggy "glibc 2.3.2".
2299506f1d07SSam Ravnborg
2300b0b49f26SAndy Lutomirski	  The symptom of the bug is that everything crashes on startup, saying:
2301b0b49f26SAndy Lutomirski	  dl_main: Assertion `(void *) ph->p_vaddr == _rtld_local._dl_sysinfo_dso' failed!
2302b0b49f26SAndy Lutomirski
2303b0b49f26SAndy Lutomirski	  Saying Y here changes the default value of the vdso32 boot
2304b0b49f26SAndy Lutomirski	  option from 1 to 0, which turns off the 32-bit vDSO entirely.
2305b0b49f26SAndy Lutomirski	  This works around the glibc bug but hurts performance.
2306b0b49f26SAndy Lutomirski
2307b0b49f26SAndy Lutomirski	  If unsure, say N: if you are compiling your own kernel, you
2308b0b49f26SAndy Lutomirski	  are unlikely to be using a buggy version of glibc.
2309506f1d07SSam Ravnborg
23103dc33bd3SKees Cookchoice
23113dc33bd3SKees Cook	prompt "vsyscall table for legacy applications"
23123dc33bd3SKees Cook	depends on X86_64
2313625b7b7fSAndy Lutomirski	default LEGACY_VSYSCALL_XONLY
23143dc33bd3SKees Cook	help
23153dc33bd3SKees Cook	  Legacy user code that does not know how to find the vDSO expects
23163dc33bd3SKees Cook	  to be able to issue three syscalls by calling fixed addresses in
23173dc33bd3SKees Cook	  kernel space. Since this location is not randomized with ASLR,
23183dc33bd3SKees Cook	  it can be used to assist security vulnerability exploitation.
23193dc33bd3SKees Cook
23203dc33bd3SKees Cook	  This setting can be changed at boot time via the kernel command
2321bf00745eSAndy Lutomirski	  line parameter vsyscall=[emulate|xonly|none].  Emulate mode
2322bf00745eSAndy Lutomirski	  is deprecated and can only be enabled using the kernel command
2323bf00745eSAndy Lutomirski	  line.
23243dc33bd3SKees Cook
23253dc33bd3SKees Cook	  On a system with recent enough glibc (2.14 or newer) and no
23263dc33bd3SKees Cook	  static binaries, you can say None without a performance penalty
23273dc33bd3SKees Cook	  to improve security.
23283dc33bd3SKees Cook
2329bd49e16eSAndy Lutomirski	  If unsure, select "Emulate execution only".
23303dc33bd3SKees Cook
2331bd49e16eSAndy Lutomirski	config LEGACY_VSYSCALL_XONLY
2332bd49e16eSAndy Lutomirski		bool "Emulate execution only"
2333bd49e16eSAndy Lutomirski		help
2334bd49e16eSAndy Lutomirski		  The kernel traps and emulates calls into the fixed vsyscall
2335bd49e16eSAndy Lutomirski		  address mapping and does not allow reads.  This
2336bd49e16eSAndy Lutomirski		  configuration is recommended when userspace might use the
2337bd49e16eSAndy Lutomirski		  legacy vsyscall area but support for legacy binary
2338bd49e16eSAndy Lutomirski		  instrumentation of legacy code is not needed.  It mitigates
2339bd49e16eSAndy Lutomirski		  certain uses of the vsyscall area as an ASLR-bypassing
2340bd49e16eSAndy Lutomirski		  buffer.
23413dc33bd3SKees Cook
23423dc33bd3SKees Cook	config LEGACY_VSYSCALL_NONE
23433dc33bd3SKees Cook		bool "None"
23443dc33bd3SKees Cook		help
23453dc33bd3SKees Cook		  There will be no vsyscall mapping at all. This will
23463dc33bd3SKees Cook		  eliminate any risk of ASLR bypass due to the vsyscall
23473dc33bd3SKees Cook		  fixed address mapping. Attempts to use the vsyscalls
23483dc33bd3SKees Cook		  will be reported to dmesg, so that either old or
23493dc33bd3SKees Cook		  malicious userspace programs can be identified.
23503dc33bd3SKees Cook
23513dc33bd3SKees Cookendchoice
23523dc33bd3SKees Cook
2353516cbf37STim Birdconfig CMDLINE_BOOL
2354516cbf37STim Bird	bool "Built-in kernel command line"
2355a7f7f624SMasahiro Yamada	help
2356516cbf37STim Bird	  Allow for specifying boot arguments to the kernel at
2357516cbf37STim Bird	  build time.  On some systems (e.g. embedded ones), it is
2358516cbf37STim Bird	  necessary or convenient to provide some or all of the
2359516cbf37STim Bird	  kernel boot arguments with the kernel itself (that is,
2360516cbf37STim Bird	  to not rely on the boot loader to provide them.)
2361516cbf37STim Bird
2362516cbf37STim Bird	  To compile command line arguments into the kernel,
2363516cbf37STim Bird	  set this option to 'Y', then fill in the
236469711ca1SSébastien Hinderer	  boot arguments in CONFIG_CMDLINE.
2365516cbf37STim Bird
2366516cbf37STim Bird	  Systems with fully functional boot loaders (i.e. non-embedded)
2367516cbf37STim Bird	  should leave this option set to 'N'.
2368516cbf37STim Bird
2369516cbf37STim Birdconfig CMDLINE
2370516cbf37STim Bird	string "Built-in kernel command string"
2371516cbf37STim Bird	depends on CMDLINE_BOOL
2372516cbf37STim Bird	default ""
2373a7f7f624SMasahiro Yamada	help
2374516cbf37STim Bird	  Enter arguments here that should be compiled into the kernel
2375516cbf37STim Bird	  image and used at boot time.  If the boot loader provides a
2376516cbf37STim Bird	  command line at boot time, it is appended to this string to
2377516cbf37STim Bird	  form the full kernel command line, when the system boots.
2378516cbf37STim Bird
2379516cbf37STim Bird	  However, you can use the CONFIG_CMDLINE_OVERRIDE option to
2380516cbf37STim Bird	  change this behavior.
2381516cbf37STim Bird
2382516cbf37STim Bird	  In most cases, the command line (whether built-in or provided
2383516cbf37STim Bird	  by the boot loader) should specify the device for the root
2384516cbf37STim Bird	  file system.
2385516cbf37STim Bird
2386516cbf37STim Birdconfig CMDLINE_OVERRIDE
2387516cbf37STim Bird	bool "Built-in command line overrides boot loader arguments"
2388645e6466SAnders Roxell	depends on CMDLINE_BOOL && CMDLINE != ""
2389a7f7f624SMasahiro Yamada	help
2390516cbf37STim Bird	  Set this option to 'Y' to have the kernel ignore the boot loader
2391516cbf37STim Bird	  command line, and use ONLY the built-in command line.
2392516cbf37STim Bird
2393516cbf37STim Bird	  This is used to work around broken boot loaders.  This should
2394516cbf37STim Bird	  be set to 'N' under normal conditions.
2395516cbf37STim Bird
2396a5b9e5a2SAndy Lutomirskiconfig MODIFY_LDT_SYSCALL
2397a5b9e5a2SAndy Lutomirski	bool "Enable the LDT (local descriptor table)" if EXPERT
2398a5b9e5a2SAndy Lutomirski	default y
2399a7f7f624SMasahiro Yamada	help
2400a5b9e5a2SAndy Lutomirski	  Linux can allow user programs to install a per-process x86
2401a5b9e5a2SAndy Lutomirski	  Local Descriptor Table (LDT) using the modify_ldt(2) system
2402a5b9e5a2SAndy Lutomirski	  call.  This is required to run 16-bit or segmented code such as
2403a5b9e5a2SAndy Lutomirski	  DOSEMU or some Wine programs.  It is also used by some very old
2404a5b9e5a2SAndy Lutomirski	  threading libraries.
2405a5b9e5a2SAndy Lutomirski
2406a5b9e5a2SAndy Lutomirski	  Enabling this feature adds a small amount of overhead to
2407a5b9e5a2SAndy Lutomirski	  context switches and increases the low-level kernel attack
2408a5b9e5a2SAndy Lutomirski	  surface.  Disabling it removes the modify_ldt(2) system call.
2409a5b9e5a2SAndy Lutomirski
2410a5b9e5a2SAndy Lutomirski	  Saying 'N' here may make sense for embedded or server kernels.
2411a5b9e5a2SAndy Lutomirski
24123aac3ebeSThomas Gleixnerconfig STRICT_SIGALTSTACK_SIZE
24133aac3ebeSThomas Gleixner	bool "Enforce strict size checking for sigaltstack"
24143aac3ebeSThomas Gleixner	depends on DYNAMIC_SIGFRAME
24153aac3ebeSThomas Gleixner	help
24163aac3ebeSThomas Gleixner	  For historical reasons MINSIGSTKSZ is a constant which became
24173aac3ebeSThomas Gleixner	  already too small with AVX512 support. Add a mechanism to
24183aac3ebeSThomas Gleixner	  enforce strict checking of the sigaltstack size against the
24193aac3ebeSThomas Gleixner	  real size of the FPU frame. This option enables the check
24203aac3ebeSThomas Gleixner	  by default. It can also be controlled via the kernel command
24213aac3ebeSThomas Gleixner	  line option 'strict_sas_size' independent of this config
24223aac3ebeSThomas Gleixner	  switch. Enabling it might break existing applications which
24233aac3ebeSThomas Gleixner	  allocate a too small sigaltstack but 'work' because they
24243aac3ebeSThomas Gleixner	  never get a signal delivered.
24253aac3ebeSThomas Gleixner
24263aac3ebeSThomas Gleixner	  Say 'N' unless you want to really enforce this check.
24273aac3ebeSThomas Gleixner
2428b700e7f0SSeth Jenningssource "kernel/livepatch/Kconfig"
2429b700e7f0SSeth Jennings
2430506f1d07SSam Ravnborgendmenu
2431506f1d07SSam Ravnborg
2432f43b9876SPeter Zijlstraconfig CC_HAS_SLS
2433f43b9876SPeter Zijlstra	def_bool $(cc-option,-mharden-sls=all)
2434f43b9876SPeter Zijlstra
2435f43b9876SPeter Zijlstraconfig CC_HAS_RETURN_THUNK
2436f43b9876SPeter Zijlstra	def_bool $(cc-option,-mfunction-return=thunk-extern)
2437f43b9876SPeter Zijlstra
2438f43b9876SPeter Zijlstramenuconfig SPECULATION_MITIGATIONS
2439f43b9876SPeter Zijlstra	bool "Mitigations for speculative execution vulnerabilities"
2440f43b9876SPeter Zijlstra	default y
2441f43b9876SPeter Zijlstra	help
2442f43b9876SPeter Zijlstra	  Say Y here to enable options which enable mitigations for
2443f43b9876SPeter Zijlstra	  speculative execution hardware vulnerabilities.
2444f43b9876SPeter Zijlstra
2445f43b9876SPeter Zijlstra	  If you say N, all mitigations will be disabled. You really
2446f43b9876SPeter Zijlstra	  should know what you are doing to say so.
2447f43b9876SPeter Zijlstra
2448f43b9876SPeter Zijlstraif SPECULATION_MITIGATIONS
2449f43b9876SPeter Zijlstra
2450f43b9876SPeter Zijlstraconfig PAGE_TABLE_ISOLATION
2451f43b9876SPeter Zijlstra	bool "Remove the kernel mapping in user mode"
2452f43b9876SPeter Zijlstra	default y
2453f43b9876SPeter Zijlstra	depends on (X86_64 || X86_PAE)
2454f43b9876SPeter Zijlstra	help
2455f43b9876SPeter Zijlstra	  This feature reduces the number of hardware side channels by
2456f43b9876SPeter Zijlstra	  ensuring that the majority of kernel addresses are not mapped
2457f43b9876SPeter Zijlstra	  into userspace.
2458f43b9876SPeter Zijlstra
2459f43b9876SPeter Zijlstra	  See Documentation/x86/pti.rst for more details.
2460f43b9876SPeter Zijlstra
2461f43b9876SPeter Zijlstraconfig RETPOLINE
2462f43b9876SPeter Zijlstra	bool "Avoid speculative indirect branches in kernel"
2463f43b9876SPeter Zijlstra	select OBJTOOL if HAVE_OBJTOOL
2464f43b9876SPeter Zijlstra	default y
2465f43b9876SPeter Zijlstra	help
2466f43b9876SPeter Zijlstra	  Compile kernel with the retpoline compiler options to guard against
2467f43b9876SPeter Zijlstra	  kernel-to-user data leaks by avoiding speculative indirect
2468f43b9876SPeter Zijlstra	  branches. Requires a compiler with -mindirect-branch=thunk-extern
2469f43b9876SPeter Zijlstra	  support for full protection. The kernel may run slower.
2470f43b9876SPeter Zijlstra
2471f43b9876SPeter Zijlstraconfig RETHUNK
2472f43b9876SPeter Zijlstra	bool "Enable return-thunks"
2473f43b9876SPeter Zijlstra	depends on RETPOLINE && CC_HAS_RETURN_THUNK
2474f43b9876SPeter Zijlstra	select OBJTOOL if HAVE_OBJTOOL
2475b648ab48SBen Hutchings	default y if X86_64
2476f43b9876SPeter Zijlstra	help
2477f43b9876SPeter Zijlstra	  Compile the kernel with the return-thunks compiler option to guard
2478f43b9876SPeter Zijlstra	  against kernel-to-user data leaks by avoiding return speculation.
2479f43b9876SPeter Zijlstra	  Requires a compiler with -mfunction-return=thunk-extern
2480f43b9876SPeter Zijlstra	  support for full protection. The kernel may run slower.
2481f43b9876SPeter Zijlstra
2482f43b9876SPeter Zijlstraconfig CPU_UNRET_ENTRY
2483f43b9876SPeter Zijlstra	bool "Enable UNRET on kernel entry"
2484b648ab48SBen Hutchings	depends on CPU_SUP_AMD && RETHUNK && X86_64
2485f43b9876SPeter Zijlstra	default y
2486f43b9876SPeter Zijlstra	help
2487f43b9876SPeter Zijlstra	  Compile the kernel with support for the retbleed=unret mitigation.
2488f43b9876SPeter Zijlstra
2489f43b9876SPeter Zijlstraconfig CPU_IBPB_ENTRY
2490f43b9876SPeter Zijlstra	bool "Enable IBPB on kernel entry"
2491b648ab48SBen Hutchings	depends on CPU_SUP_AMD && X86_64
2492f43b9876SPeter Zijlstra	default y
2493f43b9876SPeter Zijlstra	help
2494f43b9876SPeter Zijlstra	  Compile the kernel with support for the retbleed=ibpb mitigation.
2495f43b9876SPeter Zijlstra
2496f43b9876SPeter Zijlstraconfig CPU_IBRS_ENTRY
2497f43b9876SPeter Zijlstra	bool "Enable IBRS on kernel entry"
2498b648ab48SBen Hutchings	depends on CPU_SUP_INTEL && X86_64
2499f43b9876SPeter Zijlstra	default y
2500f43b9876SPeter Zijlstra	help
2501f43b9876SPeter Zijlstra	  Compile the kernel with support for the spectre_v2=ibrs mitigation.
2502f43b9876SPeter Zijlstra	  This mitigates both spectre_v2 and retbleed at great cost to
2503f43b9876SPeter Zijlstra	  performance.
2504f43b9876SPeter Zijlstra
2505f43b9876SPeter Zijlstraconfig SLS
2506f43b9876SPeter Zijlstra	bool "Mitigate Straight-Line-Speculation"
2507f43b9876SPeter Zijlstra	depends on CC_HAS_SLS && X86_64
2508f43b9876SPeter Zijlstra	select OBJTOOL if HAVE_OBJTOOL
2509f43b9876SPeter Zijlstra	default n
2510f43b9876SPeter Zijlstra	help
2511f43b9876SPeter Zijlstra	  Compile the kernel with straight-line-speculation options to guard
2512f43b9876SPeter Zijlstra	  against straight line speculation. The kernel image might be slightly
2513f43b9876SPeter Zijlstra	  larger.
2514f43b9876SPeter Zijlstra
2515f43b9876SPeter Zijlstraendif
2516f43b9876SPeter Zijlstra
25173072e413SMichal Hockoconfig ARCH_HAS_ADD_PAGES
25183072e413SMichal Hocko	def_bool y
25195c11f00bSDavid Hildenbrand	depends on ARCH_ENABLE_MEMORY_HOTPLUG
25203072e413SMichal Hocko
2521f91ef222SOscar Salvadorconfig ARCH_MHP_MEMMAP_ON_MEMORY_ENABLE
2522f91ef222SOscar Salvador	def_bool y
2523f91ef222SOscar Salvador
2524da85f865SBjorn Helgaasmenu "Power management and ACPI options"
2525e279b6c1SSam Ravnborg
2526e279b6c1SSam Ravnborgconfig ARCH_HIBERNATION_HEADER
25273c2362e6SHarvey Harrison	def_bool y
252844556530SZhimin Gu	depends on HIBERNATION
2529e279b6c1SSam Ravnborg
2530e279b6c1SSam Ravnborgsource "kernel/power/Kconfig"
2531e279b6c1SSam Ravnborg
2532e279b6c1SSam Ravnborgsource "drivers/acpi/Kconfig"
2533e279b6c1SSam Ravnborg
2534a6b68076SAndi Kleenconfig X86_APM_BOOT
25356fc108a0SJan Beulich	def_bool y
2536282e5aabSPaul Bolle	depends on APM
2537a6b68076SAndi Kleen
2538e279b6c1SSam Ravnborgmenuconfig APM
2539e279b6c1SSam Ravnborg	tristate "APM (Advanced Power Management) BIOS support"
2540efefa6f6SIngo Molnar	depends on X86_32 && PM_SLEEP
2541a7f7f624SMasahiro Yamada	help
2542e279b6c1SSam Ravnborg	  APM is a BIOS specification for saving power using several different
2543e279b6c1SSam Ravnborg	  techniques. This is mostly useful for battery powered laptops with
2544e279b6c1SSam Ravnborg	  APM compliant BIOSes. If you say Y here, the system time will be
2545e279b6c1SSam Ravnborg	  reset after a RESUME operation, the /proc/apm device will provide
2546e279b6c1SSam Ravnborg	  battery status information, and user-space programs will receive
2547e279b6c1SSam Ravnborg	  notification of APM "events" (e.g. battery status change).
2548e279b6c1SSam Ravnborg
2549e279b6c1SSam Ravnborg	  If you select "Y" here, you can disable actual use of the APM
2550e279b6c1SSam Ravnborg	  BIOS by passing the "apm=off" option to the kernel at boot time.
2551e279b6c1SSam Ravnborg
2552e279b6c1SSam Ravnborg	  Note that the APM support is almost completely disabled for
2553e279b6c1SSam Ravnborg	  machines with more than one CPU.
2554e279b6c1SSam Ravnborg
2555e279b6c1SSam Ravnborg	  In order to use APM, you will need supporting software. For location
2556151f4e2bSMauro Carvalho Chehab	  and more information, read <file:Documentation/power/apm-acpi.rst>
25572dc98fd3SMichael Witten	  and the Battery Powered Linux mini-HOWTO, available from
2558e279b6c1SSam Ravnborg	  <http://www.tldp.org/docs.html#howto>.
2559e279b6c1SSam Ravnborg
2560e279b6c1SSam Ravnborg	  This driver does not spin down disk drives (see the hdparm(8)
2561e279b6c1SSam Ravnborg	  manpage ("man 8 hdparm") for that), and it doesn't turn off
2562e279b6c1SSam Ravnborg	  VESA-compliant "green" monitors.
2563e279b6c1SSam Ravnborg
2564e279b6c1SSam Ravnborg	  This driver does not support the TI 4000M TravelMate and the ACER
2565e279b6c1SSam Ravnborg	  486/DX4/75 because they don't have compliant BIOSes. Many "green"
2566e279b6c1SSam Ravnborg	  desktop machines also don't have compliant BIOSes, and this driver
2567e279b6c1SSam Ravnborg	  may cause those machines to panic during the boot phase.
2568e279b6c1SSam Ravnborg
2569e279b6c1SSam Ravnborg	  Generally, if you don't have a battery in your machine, there isn't
2570e279b6c1SSam Ravnborg	  much point in using this driver and you should say N. If you get
2571e279b6c1SSam Ravnborg	  random kernel OOPSes or reboots that don't seem to be related to
2572e279b6c1SSam Ravnborg	  anything, try disabling/enabling this option (or disabling/enabling
2573e279b6c1SSam Ravnborg	  APM in your BIOS).
2574e279b6c1SSam Ravnborg
2575e279b6c1SSam Ravnborg	  Some other things you should try when experiencing seemingly random,
2576e279b6c1SSam Ravnborg	  "weird" problems:
2577e279b6c1SSam Ravnborg
2578e279b6c1SSam Ravnborg	  1) make sure that you have enough swap space and that it is
2579e279b6c1SSam Ravnborg	  enabled.
2580e279b6c1SSam Ravnborg	  2) pass the "no-hlt" option to the kernel
2581e279b6c1SSam Ravnborg	  3) switch on floating point emulation in the kernel and pass
2582e279b6c1SSam Ravnborg	  the "no387" option to the kernel
2583e279b6c1SSam Ravnborg	  4) pass the "floppy=nodma" option to the kernel
2584e279b6c1SSam Ravnborg	  5) pass the "mem=4M" option to the kernel (thereby disabling
2585e279b6c1SSam Ravnborg	  all but the first 4 MB of RAM)
2586e279b6c1SSam Ravnborg	  6) make sure that the CPU is not over clocked.
2587e279b6c1SSam Ravnborg	  7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/>
2588e279b6c1SSam Ravnborg	  8) disable the cache from your BIOS settings
2589e279b6c1SSam Ravnborg	  9) install a fan for the video card or exchange video RAM
2590e279b6c1SSam Ravnborg	  10) install a better fan for the CPU
2591e279b6c1SSam Ravnborg	  11) exchange RAM chips
2592e279b6c1SSam Ravnborg	  12) exchange the motherboard.
2593e279b6c1SSam Ravnborg
2594e279b6c1SSam Ravnborg	  To compile this driver as a module, choose M here: the
2595e279b6c1SSam Ravnborg	  module will be called apm.
2596e279b6c1SSam Ravnborg
2597e279b6c1SSam Ravnborgif APM
2598e279b6c1SSam Ravnborg
2599e279b6c1SSam Ravnborgconfig APM_IGNORE_USER_SUSPEND
2600e279b6c1SSam Ravnborg	bool "Ignore USER SUSPEND"
2601a7f7f624SMasahiro Yamada	help
2602e279b6c1SSam Ravnborg	  This option will ignore USER SUSPEND requests. On machines with a
2603e279b6c1SSam Ravnborg	  compliant APM BIOS, you want to say N. However, on the NEC Versa M
2604e279b6c1SSam Ravnborg	  series notebooks, it is necessary to say Y because of a BIOS bug.
2605e279b6c1SSam Ravnborg
2606e279b6c1SSam Ravnborgconfig APM_DO_ENABLE
2607e279b6c1SSam Ravnborg	bool "Enable PM at boot time"
2608a7f7f624SMasahiro Yamada	help
2609e279b6c1SSam Ravnborg	  Enable APM features at boot time. From page 36 of the APM BIOS
2610e279b6c1SSam Ravnborg	  specification: "When disabled, the APM BIOS does not automatically
2611e279b6c1SSam Ravnborg	  power manage devices, enter the Standby State, enter the Suspend
2612e279b6c1SSam Ravnborg	  State, or take power saving steps in response to CPU Idle calls."
2613e279b6c1SSam Ravnborg	  This driver will make CPU Idle calls when Linux is idle (unless this
2614e279b6c1SSam Ravnborg	  feature is turned off -- see "Do CPU IDLE calls", below). This
2615e279b6c1SSam Ravnborg	  should always save battery power, but more complicated APM features
2616e279b6c1SSam Ravnborg	  will be dependent on your BIOS implementation. You may need to turn
2617e279b6c1SSam Ravnborg	  this option off if your computer hangs at boot time when using APM
2618e279b6c1SSam Ravnborg	  support, or if it beeps continuously instead of suspending. Turn
2619e279b6c1SSam Ravnborg	  this off if you have a NEC UltraLite Versa 33/C or a Toshiba
2620e279b6c1SSam Ravnborg	  T400CDT. This is off by default since most machines do fine without
2621e279b6c1SSam Ravnborg	  this feature.
2622e279b6c1SSam Ravnborg
2623e279b6c1SSam Ravnborgconfig APM_CPU_IDLE
2624dd8af076SLen Brown	depends on CPU_IDLE
2625e279b6c1SSam Ravnborg	bool "Make CPU Idle calls when idle"
2626a7f7f624SMasahiro Yamada	help
2627e279b6c1SSam Ravnborg	  Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop.
2628e279b6c1SSam Ravnborg	  On some machines, this can activate improved power savings, such as
2629e279b6c1SSam Ravnborg	  a slowed CPU clock rate, when the machine is idle. These idle calls
2630e279b6c1SSam Ravnborg	  are made after the idle loop has run for some length of time (e.g.,
2631e279b6c1SSam Ravnborg	  333 mS). On some machines, this will cause a hang at boot time or
2632e279b6c1SSam Ravnborg	  whenever the CPU becomes idle. (On machines with more than one CPU,
2633e279b6c1SSam Ravnborg	  this option does nothing.)
2634e279b6c1SSam Ravnborg
2635e279b6c1SSam Ravnborgconfig APM_DISPLAY_BLANK
2636e279b6c1SSam Ravnborg	bool "Enable console blanking using APM"
2637a7f7f624SMasahiro Yamada	help
2638e279b6c1SSam Ravnborg	  Enable console blanking using the APM. Some laptops can use this to
2639e279b6c1SSam Ravnborg	  turn off the LCD backlight when the screen blanker of the Linux
2640e279b6c1SSam Ravnborg	  virtual console blanks the screen. Note that this is only used by
2641e279b6c1SSam Ravnborg	  the virtual console screen blanker, and won't turn off the backlight
2642e279b6c1SSam Ravnborg	  when using the X Window system. This also doesn't have anything to
2643e279b6c1SSam Ravnborg	  do with your VESA-compliant power-saving monitor. Further, this
2644e279b6c1SSam Ravnborg	  option doesn't work for all laptops -- it might not turn off your
2645e279b6c1SSam Ravnborg	  backlight at all, or it might print a lot of errors to the console,
2646e279b6c1SSam Ravnborg	  especially if you are using gpm.
2647e279b6c1SSam Ravnborg
2648e279b6c1SSam Ravnborgconfig APM_ALLOW_INTS
2649e279b6c1SSam Ravnborg	bool "Allow interrupts during APM BIOS calls"
2650a7f7f624SMasahiro Yamada	help
2651e279b6c1SSam Ravnborg	  Normally we disable external interrupts while we are making calls to
2652e279b6c1SSam Ravnborg	  the APM BIOS as a measure to lessen the effects of a badly behaving
2653e279b6c1SSam Ravnborg	  BIOS implementation.  The BIOS should reenable interrupts if it
2654e279b6c1SSam Ravnborg	  needs to.  Unfortunately, some BIOSes do not -- especially those in
2655e279b6c1SSam Ravnborg	  many of the newer IBM Thinkpads.  If you experience hangs when you
2656e279b6c1SSam Ravnborg	  suspend, try setting this to Y.  Otherwise, say N.
2657e279b6c1SSam Ravnborg
2658e279b6c1SSam Ravnborgendif # APM
2659e279b6c1SSam Ravnborg
2660bb0a56ecSDave Jonessource "drivers/cpufreq/Kconfig"
2661e279b6c1SSam Ravnborg
2662e279b6c1SSam Ravnborgsource "drivers/cpuidle/Kconfig"
2663e279b6c1SSam Ravnborg
266427471fdbSAndy Henroidsource "drivers/idle/Kconfig"
266527471fdbSAndy Henroid
2666e279b6c1SSam Ravnborgendmenu
2667e279b6c1SSam Ravnborg
2668e279b6c1SSam Ravnborgmenu "Bus options (PCI etc.)"
2669e279b6c1SSam Ravnborg
2670e279b6c1SSam Ravnborgchoice
2671e279b6c1SSam Ravnborg	prompt "PCI access mode"
2672efefa6f6SIngo Molnar	depends on X86_32 && PCI
2673e279b6c1SSam Ravnborg	default PCI_GOANY
2674a7f7f624SMasahiro Yamada	help
2675e279b6c1SSam Ravnborg	  On PCI systems, the BIOS can be used to detect the PCI devices and
2676e279b6c1SSam Ravnborg	  determine their configuration. However, some old PCI motherboards
2677e279b6c1SSam Ravnborg	  have BIOS bugs and may crash if this is done. Also, some embedded
2678e279b6c1SSam Ravnborg	  PCI-based systems don't have any BIOS at all. Linux can also try to
2679e279b6c1SSam Ravnborg	  detect the PCI hardware directly without using the BIOS.
2680e279b6c1SSam Ravnborg
2681e279b6c1SSam Ravnborg	  With this option, you can specify how Linux should detect the
2682e279b6c1SSam Ravnborg	  PCI devices. If you choose "BIOS", the BIOS will be used,
2683e279b6c1SSam Ravnborg	  if you choose "Direct", the BIOS won't be used, and if you
2684e279b6c1SSam Ravnborg	  choose "MMConfig", then PCI Express MMCONFIG will be used.
2685e279b6c1SSam Ravnborg	  If you choose "Any", the kernel will try MMCONFIG, then the
2686e279b6c1SSam Ravnborg	  direct access method and falls back to the BIOS if that doesn't
2687e279b6c1SSam Ravnborg	  work. If unsure, go with the default, which is "Any".
2688e279b6c1SSam Ravnborg
2689e279b6c1SSam Ravnborgconfig PCI_GOBIOS
2690e279b6c1SSam Ravnborg	bool "BIOS"
2691e279b6c1SSam Ravnborg
2692e279b6c1SSam Ravnborgconfig PCI_GOMMCONFIG
2693e279b6c1SSam Ravnborg	bool "MMConfig"
2694e279b6c1SSam Ravnborg
2695e279b6c1SSam Ravnborgconfig PCI_GODIRECT
2696e279b6c1SSam Ravnborg	bool "Direct"
2697e279b6c1SSam Ravnborg
26983ef0e1f8SAndres Salomonconfig PCI_GOOLPC
269976fb6570SDaniel Drake	bool "OLPC XO-1"
27003ef0e1f8SAndres Salomon	depends on OLPC
27013ef0e1f8SAndres Salomon
27022bdd1b03SAndres Salomonconfig PCI_GOANY
27032bdd1b03SAndres Salomon	bool "Any"
27042bdd1b03SAndres Salomon
2705e279b6c1SSam Ravnborgendchoice
2706e279b6c1SSam Ravnborg
2707e279b6c1SSam Ravnborgconfig PCI_BIOS
27083c2362e6SHarvey Harrison	def_bool y
2709efefa6f6SIngo Molnar	depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY)
2710e279b6c1SSam Ravnborg
2711e279b6c1SSam Ravnborg# x86-64 doesn't support PCI BIOS access from long mode so always go direct.
2712e279b6c1SSam Ravnborgconfig PCI_DIRECT
27133c2362e6SHarvey Harrison	def_bool y
27140aba496fSShaohua Li	depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC || PCI_GOMMCONFIG))
2715e279b6c1SSam Ravnborg
2716e279b6c1SSam Ravnborgconfig PCI_MMCONFIG
2717b45c9f36SJan Kiszka	bool "Support mmconfig PCI config space access" if X86_64
2718b45c9f36SJan Kiszka	default y
27194590d98fSAndy Shevchenko	depends on PCI && (ACPI || JAILHOUSE_GUEST)
2720b45c9f36SJan Kiszka	depends on X86_64 || (PCI_GOANY || PCI_GOMMCONFIG)
2721e279b6c1SSam Ravnborg
27223ef0e1f8SAndres Salomonconfig PCI_OLPC
27232bdd1b03SAndres Salomon	def_bool y
27242bdd1b03SAndres Salomon	depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY)
27253ef0e1f8SAndres Salomon
2726b5401a96SAlex Nixonconfig PCI_XEN
2727b5401a96SAlex Nixon	def_bool y
2728b5401a96SAlex Nixon	depends on PCI && XEN
2729b5401a96SAlex Nixon
27308364e1f8SJan Kiszkaconfig MMCONF_FAM10H
27318364e1f8SJan Kiszka	def_bool y
27328364e1f8SJan Kiszka	depends on X86_64 && PCI_MMCONFIG && ACPI
2733e279b6c1SSam Ravnborg
27343f6ea84aSIra W. Snyderconfig PCI_CNB20LE_QUIRK
27356a108a14SDavid Rientjes	bool "Read CNB20LE Host Bridge Windows" if EXPERT
27366ea30386SKees Cook	depends on PCI
27373f6ea84aSIra W. Snyder	help
27383f6ea84aSIra W. Snyder	  Read the PCI windows out of the CNB20LE host bridge. This allows
27393f6ea84aSIra W. Snyder	  PCI hotplug to work on systems with the CNB20LE chipset which do
27403f6ea84aSIra W. Snyder	  not have ACPI.
27413f6ea84aSIra W. Snyder
274264a5fed6SBjorn Helgaas	  There's no public spec for this chipset, and this functionality
274364a5fed6SBjorn Helgaas	  is known to be incomplete.
274464a5fed6SBjorn Helgaas
274564a5fed6SBjorn Helgaas	  You should say N unless you know you need this.
274664a5fed6SBjorn Helgaas
27473a495511SWilliam Breathitt Grayconfig ISA_BUS
274817a2a129SWilliam Breathitt Gray	bool "ISA bus support on modern systems" if EXPERT
27493a495511SWilliam Breathitt Gray	help
275017a2a129SWilliam Breathitt Gray	  Expose ISA bus device drivers and options available for selection and
275117a2a129SWilliam Breathitt Gray	  configuration. Enable this option if your target machine has an ISA
275217a2a129SWilliam Breathitt Gray	  bus. ISA is an older system, displaced by PCI and newer bus
275317a2a129SWilliam Breathitt Gray	  architectures -- if your target machine is modern, it probably does
275417a2a129SWilliam Breathitt Gray	  not have an ISA bus.
27553a495511SWilliam Breathitt Gray
27563a495511SWilliam Breathitt Gray	  If unsure, say N.
27573a495511SWilliam Breathitt Gray
27581c00f016SDavid Rientjes# x86_64 have no ISA slots, but can have ISA-style DMA.
2759e279b6c1SSam Ravnborgconfig ISA_DMA_API
27601c00f016SDavid Rientjes	bool "ISA-style DMA support" if (X86_64 && EXPERT)
27611c00f016SDavid Rientjes	default y
27621c00f016SDavid Rientjes	help
27631c00f016SDavid Rientjes	  Enables ISA-style DMA support for devices requiring such controllers.
27641c00f016SDavid Rientjes	  If unsure, say Y.
2765e279b6c1SSam Ravnborg
276651e68d05SLinus Torvaldsif X86_32
276751e68d05SLinus Torvalds
2768e279b6c1SSam Ravnborgconfig ISA
2769e279b6c1SSam Ravnborg	bool "ISA support"
2770a7f7f624SMasahiro Yamada	help
2771e279b6c1SSam Ravnborg	  Find out whether you have ISA slots on your motherboard.  ISA is the
2772e279b6c1SSam Ravnborg	  name of a bus system, i.e. the way the CPU talks to the other stuff
2773e279b6c1SSam Ravnborg	  inside your box.  Other bus systems are PCI, EISA, MicroChannel
2774e279b6c1SSam Ravnborg	  (MCA) or VESA.  ISA is an older system, now being displaced by PCI;
2775e279b6c1SSam Ravnborg	  newer boards don't support it.  If you have ISA, say Y, otherwise N.
2776e279b6c1SSam Ravnborg
2777e279b6c1SSam Ravnborgconfig SCx200
2778e279b6c1SSam Ravnborg	tristate "NatSemi SCx200 support"
2779a7f7f624SMasahiro Yamada	help
2780e279b6c1SSam Ravnborg	  This provides basic support for National Semiconductor's
2781e279b6c1SSam Ravnborg	  (now AMD's) Geode processors.  The driver probes for the
2782e279b6c1SSam Ravnborg	  PCI-IDs of several on-chip devices, so its a good dependency
2783e279b6c1SSam Ravnborg	  for other scx200_* drivers.
2784e279b6c1SSam Ravnborg
2785e279b6c1SSam Ravnborg	  If compiled as a module, the driver is named scx200.
2786e279b6c1SSam Ravnborg
2787e279b6c1SSam Ravnborgconfig SCx200HR_TIMER
2788e279b6c1SSam Ravnborg	tristate "NatSemi SCx200 27MHz High-Resolution Timer Support"
2789592913ecSJohn Stultz	depends on SCx200
2790e279b6c1SSam Ravnborg	default y
2791a7f7f624SMasahiro Yamada	help
2792e279b6c1SSam Ravnborg	  This driver provides a clocksource built upon the on-chip
2793e279b6c1SSam Ravnborg	  27MHz high-resolution timer.  Its also a workaround for
2794e279b6c1SSam Ravnborg	  NSC Geode SC-1100's buggy TSC, which loses time when the
2795e279b6c1SSam Ravnborg	  processor goes idle (as is done by the scheduler).  The
2796e279b6c1SSam Ravnborg	  other workaround is idle=poll boot option.
2797e279b6c1SSam Ravnborg
27983ef0e1f8SAndres Salomonconfig OLPC
27993ef0e1f8SAndres Salomon	bool "One Laptop Per Child support"
280054008979SThomas Gleixner	depends on !X86_PAE
28013c554946SAndres Salomon	select GPIOLIB
2802dc3119e7SThomas Gleixner	select OF
280345bb1674SDaniel Drake	select OF_PROMTREE
2804b4e51854SGrant Likely	select IRQ_DOMAIN
28050c3d931bSLubomir Rintel	select OLPC_EC
2806a7f7f624SMasahiro Yamada	help
28073ef0e1f8SAndres Salomon	  Add support for detecting the unique features of the OLPC
28083ef0e1f8SAndres Salomon	  XO hardware.
28093ef0e1f8SAndres Salomon
2810a3128588SDaniel Drakeconfig OLPC_XO1_PM
2811a3128588SDaniel Drake	bool "OLPC XO-1 Power Management"
2812fa112cf1SBorislav Petkov	depends on OLPC && MFD_CS5535=y && PM_SLEEP
2813a7f7f624SMasahiro Yamada	help
281497c4cb71SDaniel Drake	  Add support for poweroff and suspend of the OLPC XO-1 laptop.
2815bf1ebf00SDaniel Drake
2816cfee9597SDaniel Drakeconfig OLPC_XO1_RTC
2817cfee9597SDaniel Drake	bool "OLPC XO-1 Real Time Clock"
2818cfee9597SDaniel Drake	depends on OLPC_XO1_PM && RTC_DRV_CMOS
2819a7f7f624SMasahiro Yamada	help
2820cfee9597SDaniel Drake	  Add support for the XO-1 real time clock, which can be used as a
2821cfee9597SDaniel Drake	  programmable wakeup source.
2822cfee9597SDaniel Drake
28237feda8e9SDaniel Drakeconfig OLPC_XO1_SCI
28247feda8e9SDaniel Drake	bool "OLPC XO-1 SCI extras"
282592e830f2SArnd Bergmann	depends on OLPC && OLPC_XO1_PM && GPIO_CS5535=y
2826ed8e47feSRandy Dunlap	depends on INPUT=y
2827d8d01a63SDaniel Drake	select POWER_SUPPLY
2828a7f7f624SMasahiro Yamada	help
28297feda8e9SDaniel Drake	  Add support for SCI-based features of the OLPC XO-1 laptop:
28307bc74b3dSDaniel Drake	   - EC-driven system wakeups
28317feda8e9SDaniel Drake	   - Power button
28327bc74b3dSDaniel Drake	   - Ebook switch
28332cf2baeaSDaniel Drake	   - Lid switch
2834e1040ac6SDaniel Drake	   - AC adapter status updates
2835e1040ac6SDaniel Drake	   - Battery status updates
28367feda8e9SDaniel Drake
2837a0f30f59SDaniel Drakeconfig OLPC_XO15_SCI
2838a0f30f59SDaniel Drake	bool "OLPC XO-1.5 SCI extras"
2839d8d01a63SDaniel Drake	depends on OLPC && ACPI
2840d8d01a63SDaniel Drake	select POWER_SUPPLY
2841a7f7f624SMasahiro Yamada	help
2842a0f30f59SDaniel Drake	  Add support for SCI-based features of the OLPC XO-1.5 laptop:
2843a0f30f59SDaniel Drake	   - EC-driven system wakeups
2844a0f30f59SDaniel Drake	   - AC adapter status updates
2845a0f30f59SDaniel Drake	   - Battery status updates
2846e279b6c1SSam Ravnborg
2847d4f3e350SEd Wildgooseconfig ALIX
2848d4f3e350SEd Wildgoose	bool "PCEngines ALIX System Support (LED setup)"
2849d4f3e350SEd Wildgoose	select GPIOLIB
2850a7f7f624SMasahiro Yamada	help
2851d4f3e350SEd Wildgoose	  This option enables system support for the PCEngines ALIX.
2852d4f3e350SEd Wildgoose	  At present this just sets up LEDs for GPIO control on
2853d4f3e350SEd Wildgoose	  ALIX2/3/6 boards.  However, other system specific setup should
2854d4f3e350SEd Wildgoose	  get added here.
2855d4f3e350SEd Wildgoose
2856d4f3e350SEd Wildgoose	  Note: You must still enable the drivers for GPIO and LED support
2857d4f3e350SEd Wildgoose	  (GPIO_CS5535 & LEDS_GPIO) to actually use the LEDs
2858d4f3e350SEd Wildgoose
2859d4f3e350SEd Wildgoose	  Note: You have to set alix.force=1 for boards with Award BIOS.
2860d4f3e350SEd Wildgoose
2861da4e3302SPhilip Prindevilleconfig NET5501
2862da4e3302SPhilip Prindeville	bool "Soekris Engineering net5501 System Support (LEDS, GPIO, etc)"
2863da4e3302SPhilip Prindeville	select GPIOLIB
2864a7f7f624SMasahiro Yamada	help
2865da4e3302SPhilip Prindeville	  This option enables system support for the Soekris Engineering net5501.
2866da4e3302SPhilip Prindeville
28673197059aSPhilip A. Prindevilleconfig GEOS
28683197059aSPhilip A. Prindeville	bool "Traverse Technologies GEOS System Support (LEDS, GPIO, etc)"
28693197059aSPhilip A. Prindeville	select GPIOLIB
28703197059aSPhilip A. Prindeville	depends on DMI
2871a7f7f624SMasahiro Yamada	help
28723197059aSPhilip A. Prindeville	  This option enables system support for the Traverse Technologies GEOS.
28733197059aSPhilip A. Prindeville
28747d029125SVivien Didelotconfig TS5500
28757d029125SVivien Didelot	bool "Technologic Systems TS-5500 platform support"
28767d029125SVivien Didelot	depends on MELAN
28777d029125SVivien Didelot	select CHECK_SIGNATURE
28787d029125SVivien Didelot	select NEW_LEDS
28797d029125SVivien Didelot	select LEDS_CLASS
2880a7f7f624SMasahiro Yamada	help
28817d029125SVivien Didelot	  This option enables system support for the Technologic Systems TS-5500.
28827d029125SVivien Didelot
2883e279b6c1SSam Ravnborgendif # X86_32
2884e279b6c1SSam Ravnborg
288523ac4ae8SAndreas Herrmannconfig AMD_NB
2886e279b6c1SSam Ravnborg	def_bool y
28870e152cd7SBorislav Petkov	depends on CPU_SUP_AMD && PCI
2888e279b6c1SSam Ravnborg
2889e279b6c1SSam Ravnborgendmenu
2890e279b6c1SSam Ravnborg
28911572497cSChristoph Hellwigmenu "Binary Emulations"
2892e279b6c1SSam Ravnborg
2893e279b6c1SSam Ravnborgconfig IA32_EMULATION
2894e279b6c1SSam Ravnborg	bool "IA32 Emulation"
2895e279b6c1SSam Ravnborg	depends on X86_64
289639f88911SIngo Molnar	select ARCH_WANT_OLD_COMPAT_IPC
2897d1603990SRandy Dunlap	select BINFMT_ELF
289839f88911SIngo Molnar	select COMPAT_OLD_SIGACTION
2899a7f7f624SMasahiro Yamada	help
29005fd92e65SH. J. Lu	  Include code to run legacy 32-bit programs under a
29015fd92e65SH. J. Lu	  64-bit kernel. You should likely turn this on, unless you're
29025fd92e65SH. J. Lu	  100% sure that you don't have any 32-bit programs left.
2903e279b6c1SSam Ravnborg
290483a44a4fSMasahiro Yamadaconfig X86_X32_ABI
29056ea30386SKees Cook	bool "x32 ABI for 64-bit mode"
29069b54050bSBrian Gerst	depends on X86_64
2907aaeed6ecSNathan Chancellor	# llvm-objcopy does not convert x86_64 .note.gnu.property or
2908aaeed6ecSNathan Chancellor	# compressed debug sections to x86_x32 properly:
2909aaeed6ecSNathan Chancellor	# https://github.com/ClangBuiltLinux/linux/issues/514
2910aaeed6ecSNathan Chancellor	# https://github.com/ClangBuiltLinux/linux/issues/1141
2911aaeed6ecSNathan Chancellor	depends on $(success,$(OBJCOPY) --version | head -n1 | grep -qv llvm)
2912a7f7f624SMasahiro Yamada	help
29135fd92e65SH. J. Lu	  Include code to run binaries for the x32 native 32-bit ABI
29145fd92e65SH. J. Lu	  for 64-bit processors.  An x32 process gets access to the
29155fd92e65SH. J. Lu	  full 64-bit register file and wide data path while leaving
29165fd92e65SH. J. Lu	  pointers at 32 bits for smaller memory footprint.
29175fd92e65SH. J. Lu
2918953fee1dSIngo Molnarconfig COMPAT_32
2919953fee1dSIngo Molnar	def_bool y
2920953fee1dSIngo Molnar	depends on IA32_EMULATION || X86_32
2921953fee1dSIngo Molnar	select HAVE_UID16
2922953fee1dSIngo Molnar	select OLD_SIGSUSPEND3
2923953fee1dSIngo Molnar
2924e279b6c1SSam Ravnborgconfig COMPAT
29253c2362e6SHarvey Harrison	def_bool y
292683a44a4fSMasahiro Yamada	depends on IA32_EMULATION || X86_X32_ABI
2927e279b6c1SSam Ravnborg
2928e279b6c1SSam Ravnborgconfig COMPAT_FOR_U64_ALIGNMENT
29293120e25eSJan Beulich	def_bool y
2930a9251280SLinus Torvalds	depends on COMPAT
2931ee009e4aSDavid Howells
2932e279b6c1SSam Ravnborgendmenu
2933e279b6c1SSam Ravnborg
2934e5beae16SKeith Packardconfig HAVE_ATOMIC_IOMAP
2935e5beae16SKeith Packard	def_bool y
2936e5beae16SKeith Packard	depends on X86_32
2937e5beae16SKeith Packard
2938edf88417SAvi Kivitysource "arch/x86/kvm/Kconfig"
29395e8ebd84SJason A. Donenfeld
29405e8ebd84SJason A. Donenfeldsource "arch/x86/Kconfig.assembler"
2941