xref: /linux/arch/x86/Kconfig (revision 8b766b0f8eece55155146f7628610ce54a065e0f)
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
72fa5b6ec9SLaura Abbott	select ARCH_HAS_DEBUG_VIRTUAL
73399145f9SAnshuman Khandual	select ARCH_HAS_DEBUG_VM_PGTABLE	if !X86_PAE
7421266be9SDan Williams	select ARCH_HAS_DEVMEM_IS_ALLOWED
75b1a57bbfSDouglas Anderson	select ARCH_HAS_EARLY_DEBUG		if KGDB
766471b825SIngo Molnar	select ARCH_HAS_ELF_RANDOMIZE
7772d93104SLinus Torvalds	select ARCH_HAS_FAST_MULTIPLIER
78316d097cSDave Hansen	select ARCH_HAS_FILTER_PGPROT
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
880aed55afSDan Williams	select ARCH_HAS_UACCESS_FLUSHCACHE	if X86_64
89ec6347bbSDan Williams	select ARCH_HAS_COPY_MC			if X86_64
90d2852a22SDaniel Borkmann	select ARCH_HAS_SET_MEMORY
91d253ca0cSRick Edgecombe	select ARCH_HAS_SET_DIRECT_MAP
92ad21fc4fSLaura Abbott	select ARCH_HAS_STRICT_KERNEL_RWX
93ad21fc4fSLaura Abbott	select ARCH_HAS_STRICT_MODULE_RWX
94ac1ab12aSMathieu Desnoyers	select ARCH_HAS_SYNC_CORE_BEFORE_USERMODE
9525c619e5SBrian Gerst	select ARCH_HAS_SYSCALL_WRAPPER
96c6d30853SAndrey Ryabinin	select ARCH_HAS_UBSAN_SANITIZE_ALL
977e01ccb4SZong Li	select ARCH_HAS_DEBUG_WX
9863703f37SKefeng Wang	select ARCH_HAS_ZONE_DMA_SET if EXPERT
996471b825SIngo Molnar	select ARCH_HAVE_NMI_SAFE_CMPXCHG
1006471b825SIngo Molnar	select ARCH_MIGHT_HAVE_ACPI_PDC		if ACPI
10177fbbc81SMark Salter	select ARCH_MIGHT_HAVE_PC_PARPORT
1025e2c18c0SMark Salter	select ARCH_MIGHT_HAVE_PC_SERIO
1033599fe12SThomas Gleixner	select ARCH_STACKWALK
1042c870e61SArnd Bergmann	select ARCH_SUPPORTS_ACPI
1056471b825SIngo Molnar	select ARCH_SUPPORTS_ATOMIC_RMW
1065d6ad668SMike Rapoport	select ARCH_SUPPORTS_DEBUG_PAGEALLOC
107d283d422SPasha Tatashin	select ARCH_SUPPORTS_PAGE_TABLE_CHECK	if X86_64
1086471b825SIngo Molnar	select ARCH_SUPPORTS_NUMA_BALANCING	if X86_64
10914df3267SThomas Gleixner	select ARCH_SUPPORTS_KMAP_LOCAL_FORCE_MAP	if NR_CPUS <= 4096
110583bfd48SNathan Chancellor	select ARCH_SUPPORTS_LTO_CLANG
111583bfd48SNathan Chancellor	select ARCH_SUPPORTS_LTO_CLANG_THIN
1126471b825SIngo Molnar	select ARCH_USE_BUILTIN_BSWAP
113dce44566SAnshuman Khandual	select ARCH_USE_MEMTEST
1146471b825SIngo Molnar	select ARCH_USE_QUEUED_RWLOCKS
1156471b825SIngo Molnar	select ARCH_USE_QUEUED_SPINLOCKS
1162ce0d7f9SMark Brown	select ARCH_USE_SYM_ANNOTATIONS
117ce4a4e56SAndy Lutomirski	select ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH
11881c22041SDaniel Borkmann	select ARCH_WANT_DEFAULT_BPF_JIT	if X86_64
119c763ea26SIngo Molnar	select ARCH_WANTS_DYNAMIC_TASK_STRUCT
12051c2ee6dSNick Desaulniers	select ARCH_WANTS_NO_INSTR
1213876d4a3SAlexandre Ghiti	select ARCH_WANT_HUGE_PMD_SHARE
12259612b24SNathan Chancellor	select ARCH_WANT_LD_ORPHAN_WARN
12338d8b4e6SHuang Ying	select ARCH_WANTS_THP_SWAP		if X86_64
124b5f06f64SBalbir Singh	select ARCH_HAS_PARANOID_L1D_FLUSH
12510916706SShile Zhang	select BUILDTIME_TABLE_SORT
1266471b825SIngo Molnar	select CLKEVT_I8253
1276471b825SIngo Molnar	select CLOCKSOURCE_VALIDATE_LAST_CYCLE
1286471b825SIngo Molnar	select CLOCKSOURCE_WATCHDOG
1296471b825SIngo Molnar	select DCACHE_WORD_ACCESS
1303aac3ebeSThomas Gleixner	select DYNAMIC_SIGFRAME
13145471cd9SLinus Torvalds	select EDAC_ATOMIC_SCRUB
13245471cd9SLinus Torvalds	select EDAC_SUPPORT
1336471b825SIngo Molnar	select GENERIC_CLOCKEVENTS_BROADCAST	if X86_64 || (X86_32 && X86_LOCAL_APIC)
1346471b825SIngo Molnar	select GENERIC_CLOCKEVENTS_MIN_ADJUST
1356471b825SIngo Molnar	select GENERIC_CMOS_UPDATE
1366471b825SIngo Molnar	select GENERIC_CPU_AUTOPROBE
13761dc0f55SThomas Gleixner	select GENERIC_CPU_VULNERABILITIES
1386471b825SIngo Molnar	select GENERIC_EARLY_IOREMAP
13927d6b4d1SThomas Gleixner	select GENERIC_ENTRY
1406471b825SIngo Molnar	select GENERIC_IOMAP
141c7d6c9ddSThomas Gleixner	select GENERIC_IRQ_EFFECTIVE_AFF_MASK	if SMP
1420fa115daSThomas Gleixner	select GENERIC_IRQ_MATRIX_ALLOCATOR	if X86_LOCAL_APIC
143ad7a929fSThomas Gleixner	select GENERIC_IRQ_MIGRATION		if SMP
1446471b825SIngo Molnar	select GENERIC_IRQ_PROBE
145c201c917SThomas Gleixner	select GENERIC_IRQ_RESERVATION_MODE
1466471b825SIngo Molnar	select GENERIC_IRQ_SHOW
1476471b825SIngo Molnar	select GENERIC_PENDING_IRQ		if SMP
1482ae27137SSteven Price	select GENERIC_PTDUMP
1496471b825SIngo Molnar	select GENERIC_SMP_IDLE_THREAD
1506471b825SIngo Molnar	select GENERIC_TIME_VSYSCALL
1517ac87074SVincenzo Frascino	select GENERIC_GETTIMEOFDAY
152550a77a7SDmitry Safonov	select GENERIC_VDSO_TIME_NS
15339656e83SChristoph Hellwig	select GUP_GET_PTE_LOW_HIGH		if X86_PAE
15417e5888eSHans de Goede	select HARDIRQS_SW_RESEND
1557edaeb68SThomas Gleixner	select HARDLOCKUP_CHECK_TIMESTAMP	if X86_64
1566471b825SIngo Molnar	select HAVE_ACPI_APEI			if ACPI
1576471b825SIngo Molnar	select HAVE_ACPI_APEI_NMI		if ACPI
1586471b825SIngo Molnar	select HAVE_ALIGNED_STRUCT_PAGE		if SLUB
1596471b825SIngo Molnar	select HAVE_ARCH_AUDITSYSCALL
1606471b825SIngo Molnar	select HAVE_ARCH_HUGE_VMAP		if X86_64 || X86_PAE
1616471b825SIngo Molnar	select HAVE_ARCH_JUMP_LABEL
162b34006c4SArd Biesheuvel	select HAVE_ARCH_JUMP_LABEL_RELATIVE
163d17a1d97SAndrey Ryabinin	select HAVE_ARCH_KASAN			if X86_64
1640609ae01SDaniel Axtens	select HAVE_ARCH_KASAN_VMALLOC		if X86_64
1651dc0da6eSAlexander Potapenko	select HAVE_ARCH_KFENCE
1666471b825SIngo Molnar	select HAVE_ARCH_KGDB
1679e08f57dSDaniel Cashman	select HAVE_ARCH_MMAP_RND_BITS		if MMU
1689e08f57dSDaniel Cashman	select HAVE_ARCH_MMAP_RND_COMPAT_BITS	if MMU && COMPAT
1691b028f78SDmitry Safonov	select HAVE_ARCH_COMPAT_MMAP_BASES	if MMU && COMPAT
170271ca788SArd Biesheuvel	select HAVE_ARCH_PREL32_RELOCATIONS
1716471b825SIngo Molnar	select HAVE_ARCH_SECCOMP_FILTER
172f7d83c1cSKees Cook	select HAVE_ARCH_THREAD_STRUCT_WHITELIST
173afaef01cSAlexander Popov	select HAVE_ARCH_STACKLEAK
1746471b825SIngo Molnar	select HAVE_ARCH_TRACEHOOK
1756471b825SIngo Molnar	select HAVE_ARCH_TRANSPARENT_HUGEPAGE
176a00cc7d9SMatthew Wilcox	select HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD if X86_64
177b64d8d1eSPeter Xu	select HAVE_ARCH_USERFAULTFD_WP         if X86_64 && USERFAULTFD
1787677f7fdSAxel Rasmussen	select HAVE_ARCH_USERFAULTFD_MINOR	if X86_64 && USERFAULTFD
179e37e43a4SAndy Lutomirski	select HAVE_ARCH_VMAP_STACK		if X86_64
180fe950f60SKees Cook	select HAVE_ARCH_RANDOMIZE_KSTACK_OFFSET
181c763ea26SIngo Molnar	select HAVE_ARCH_WITHIN_STACK_FRAMES
1822ff2b7ecSMasahiro Yamada	select HAVE_ASM_MODVERSIONS
1836471b825SIngo Molnar	select HAVE_CMPXCHG_DOUBLE
1846471b825SIngo Molnar	select HAVE_CMPXCHG_LOCAL
1856471b825SIngo Molnar	select HAVE_CONTEXT_TRACKING		if X86_64
186d1f250e2SFrederic Weisbecker	select HAVE_CONTEXT_TRACKING_OFFSTACK	if HAVE_CONTEXT_TRACKING
1876471b825SIngo Molnar	select HAVE_C_RECORDMCOUNT
1886dafca97SSami Tolvanen	select HAVE_OBJTOOL_MCOUNT		if STACK_VALIDATION
1894ed308c4SSteven Rostedt (Google)	select HAVE_BUILDTIME_MCOUNT_SORT
1906471b825SIngo Molnar	select HAVE_DEBUG_KMEMLEAK
1919c5a3621SAkinobu Mita	select HAVE_DMA_CONTIGUOUS
192677aa9f7SSteven Rostedt	select HAVE_DYNAMIC_FTRACE
19306aeaaeaSMasami Hiramatsu	select HAVE_DYNAMIC_FTRACE_WITH_REGS
19402a474caSSteven Rostedt (VMware)	select HAVE_DYNAMIC_FTRACE_WITH_ARGS	if X86_64
195562955feSSteven Rostedt (VMware)	select HAVE_DYNAMIC_FTRACE_WITH_DIRECT_CALLS
196c316eb44SHeiko Carstens	select HAVE_SAMPLE_FTRACE_DIRECT	if X86_64
197503e4510SHeiko Carstens	select HAVE_SAMPLE_FTRACE_DIRECT_MULTI	if X86_64
19803f5781bSWang YanQing	select HAVE_EBPF_JIT
19958340a07SJohannes Berg	select HAVE_EFFICIENT_UNALIGNED_ACCESS
2006630a8e5SChristoph Hellwig	select HAVE_EISA
2015f56a5dfSJiri Slaby	select HAVE_EXIT_THREAD
20267a929e0SChristoph Hellwig	select HAVE_FAST_GUP
203644e0e8dSSteven Rostedt (VMware)	select HAVE_FENTRY			if X86_64 || DYNAMIC_FTRACE
2046471b825SIngo Molnar	select HAVE_FTRACE_MCOUNT_RECORD
2054a30e4c9SSteven Rostedt (VMware)	select HAVE_FUNCTION_GRAPH_TRACER	if X86_32 || (X86_64 && DYNAMIC_FTRACE)
2066471b825SIngo Molnar	select HAVE_FUNCTION_TRACER
2076b90bd4bSEmese Revfy	select HAVE_GCC_PLUGINS
2080067f129SK.Prasad	select HAVE_HW_BREAKPOINT
2096471b825SIngo Molnar	select HAVE_IOREMAP_PROT
210624db9eaSThomas Gleixner	select HAVE_IRQ_EXIT_ON_IRQ_STACK	if X86_64
2116471b825SIngo Molnar	select HAVE_IRQ_TIME_ACCOUNTING
2126471b825SIngo Molnar	select HAVE_KERNEL_BZIP2
2136471b825SIngo Molnar	select HAVE_KERNEL_GZIP
2146471b825SIngo Molnar	select HAVE_KERNEL_LZ4
2156471b825SIngo Molnar	select HAVE_KERNEL_LZMA
2166471b825SIngo Molnar	select HAVE_KERNEL_LZO
2176471b825SIngo Molnar	select HAVE_KERNEL_XZ
218fb46d057SNick Terrell	select HAVE_KERNEL_ZSTD
2196471b825SIngo Molnar	select HAVE_KPROBES
2206471b825SIngo Molnar	select HAVE_KPROBES_ON_FTRACE
221540adea3SMasami Hiramatsu	select HAVE_FUNCTION_ERROR_INJECTION
2226471b825SIngo Molnar	select HAVE_KRETPROBES
2236471b825SIngo Molnar	select HAVE_KVM
2246471b825SIngo Molnar	select HAVE_LIVEPATCH			if X86_64
2250102752eSFrederic Weisbecker	select HAVE_MIXED_BREAKPOINTS_REGS
226ee9f8fceSJosh Poimboeuf	select HAVE_MOD_ARCH_SPECIFIC
2279f132f7eSJoel Fernandes (Google)	select HAVE_MOVE_PMD
228be37c98dSKalesh Singh	select HAVE_MOVE_PUD
22942a0bb3fSPetr Mladek	select HAVE_NMI
2306471b825SIngo Molnar	select HAVE_OPTPROBES
2316471b825SIngo Molnar	select HAVE_PCSPKR_PLATFORM
2326471b825SIngo Molnar	select HAVE_PERF_EVENTS
233c01d4323SFrederic Weisbecker	select HAVE_PERF_EVENTS_NMI
23492e5aae4SNicholas Piggin	select HAVE_HARDLOCKUP_DETECTOR_PERF	if PERF_EVENTS && HAVE_PERF_EVENTS_NMI
235eb01d42aSChristoph Hellwig	select HAVE_PCI
236c5e63197SJiri Olsa	select HAVE_PERF_REGS
237c5ebcedbSJiri Olsa	select HAVE_PERF_USER_STACK_DUMP
238ff2e6d72SPeter Zijlstra	select MMU_GATHER_RCU_TABLE_FREE		if PARAVIRT
23900998085SThomas Gleixner	select HAVE_POSIX_CPU_TIMERS_TASK_WORK
2406471b825SIngo Molnar	select HAVE_REGS_AND_STACK_ACCESS_API
2416415b38bSJiri Slaby	select HAVE_RELIABLE_STACKTRACE		if X86_64 && (UNWINDER_FRAME_POINTER || UNWINDER_ORC) && STACK_VALIDATION
2423c88ee19SMasami Hiramatsu	select HAVE_FUNCTION_ARG_ACCESS_API
2437ecd19cfSKefeng Wang	select HAVE_SETUP_PER_CPU_AREA
244cd1a41ceSThomas Gleixner	select HAVE_SOFTIRQ_ON_OWN_STACK
245d148eac0SMasahiro Yamada	select HAVE_STACKPROTECTOR		if CC_HAS_SANE_STACKPROTECTOR
246c763ea26SIngo Molnar	select HAVE_STACK_VALIDATION		if X86_64
247e6d6c071SJosh Poimboeuf	select HAVE_STATIC_CALL
2481e7e4788SJosh Poimboeuf	select HAVE_STATIC_CALL_INLINE		if HAVE_STACK_VALIDATION
2496ef869e0SMichal Hocko	select HAVE_PREEMPT_DYNAMIC
250d6761b8fSMathieu Desnoyers	select HAVE_RSEQ
2516471b825SIngo Molnar	select HAVE_SYSCALL_TRACEPOINTS
2526471b825SIngo Molnar	select HAVE_UNSTABLE_SCHED_CLOCK
2537c68af6eSAvi Kivity	select HAVE_USER_RETURN_NOTIFIER
2547ac87074SVincenzo Frascino	select HAVE_GENERIC_VDSO
25505736e4aSThomas Gleixner	select HOTPLUG_SMT			if SMP
256c0185808SThomas Gleixner	select IRQ_FORCED_THREADING
2577ecd19cfSKefeng Wang	select NEED_PER_CPU_EMBED_FIRST_CHUNK
2587ecd19cfSKefeng Wang	select NEED_PER_CPU_PAGE_FIRST_CHUNK
25986596f0aSChristoph Hellwig	select NEED_SG_DMA_LENGTH
2602eac9c2dSChristoph Hellwig	select PCI_DOMAINS			if PCI
261625210cfSSinan Kaya	select PCI_LOCKLESS_CONFIG		if PCI
2626471b825SIngo Molnar	select PERF_EVENTS
2633195ef59SPrarit Bhargava	select RTC_LIB
264d6faca40SArnd Bergmann	select RTC_MC146818_LIB
2656471b825SIngo Molnar	select SPARSE_IRQ
26683fe27eaSPranith Kumar	select SRCU
2671e7e4788SJosh Poimboeuf	select STACK_VALIDATION			if HAVE_STACK_VALIDATION && (HAVE_STATIC_CALL_INLINE || RETPOLINE)
2686471b825SIngo Molnar	select SYSCTL_EXCEPTION_TRACE
26915f4eae7SAndy Lutomirski	select THREAD_INFO_IN_TASK
2704aae683fSMasahiro Yamada	select TRACE_IRQFLAGS_SUPPORT
2716471b825SIngo Molnar	select USER_STACKTRACE_SUPPORT
2726471b825SIngo Molnar	select VIRT_TO_BUS
2733b02a051SIngo Molnar	select HAVE_ARCH_KCSAN			if X86_64
2746471b825SIngo Molnar	select X86_FEATURE_NAMES		if PROC_FS
2750c608dadSAubrey Li	select PROC_PID_ARCH_STATUS		if PROC_FS
27650468e43SJarkko Sakkinen	select HAVE_ARCH_NODE_DEV_GROUP		if X86_SGX
2779e2b4be3SNayna Jain	imply IMA_SECURE_AND_OR_TRUSTED_BOOT    if EFI
2787d8330a5SBalbir Singh
279ba7e4d13SIngo Molnarconfig INSTRUCTION_DECODER
2803120e25eSJan Beulich	def_bool y
2813120e25eSJan Beulich	depends on KPROBES || PERF_EVENTS || UPROBES
282ba7e4d13SIngo Molnar
28351b26adaSLinus Torvaldsconfig OUTPUT_FORMAT
28451b26adaSLinus Torvalds	string
28551b26adaSLinus Torvalds	default "elf32-i386" if X86_32
28651b26adaSLinus Torvalds	default "elf64-x86-64" if X86_64
28751b26adaSLinus Torvalds
2888d5fffb9SSam Ravnborgconfig LOCKDEP_SUPPORT
2893c2362e6SHarvey Harrison	def_bool y
2908d5fffb9SSam Ravnborg
2918d5fffb9SSam Ravnborgconfig STACKTRACE_SUPPORT
2923c2362e6SHarvey Harrison	def_bool y
2938d5fffb9SSam Ravnborg
2948d5fffb9SSam Ravnborgconfig MMU
2953c2362e6SHarvey Harrison	def_bool y
2968d5fffb9SSam Ravnborg
2979e08f57dSDaniel Cashmanconfig ARCH_MMAP_RND_BITS_MIN
2989e08f57dSDaniel Cashman	default 28 if 64BIT
2999e08f57dSDaniel Cashman	default 8
3009e08f57dSDaniel Cashman
3019e08f57dSDaniel Cashmanconfig ARCH_MMAP_RND_BITS_MAX
3029e08f57dSDaniel Cashman	default 32 if 64BIT
3039e08f57dSDaniel Cashman	default 16
3049e08f57dSDaniel Cashman
3059e08f57dSDaniel Cashmanconfig ARCH_MMAP_RND_COMPAT_BITS_MIN
3069e08f57dSDaniel Cashman	default 8
3079e08f57dSDaniel Cashman
3089e08f57dSDaniel Cashmanconfig ARCH_MMAP_RND_COMPAT_BITS_MAX
3099e08f57dSDaniel Cashman	default 16
3109e08f57dSDaniel Cashman
3118d5fffb9SSam Ravnborgconfig SBUS
3128d5fffb9SSam Ravnborg	bool
3138d5fffb9SSam Ravnborg
3148d5fffb9SSam Ravnborgconfig GENERIC_ISA_DMA
3153120e25eSJan Beulich	def_bool y
3163120e25eSJan Beulich	depends on ISA_DMA_API
3178d5fffb9SSam Ravnborg
3188d5fffb9SSam Ravnborgconfig GENERIC_BUG
3193c2362e6SHarvey Harrison	def_bool y
3208d5fffb9SSam Ravnborg	depends on BUG
321b93a531eSJan Beulich	select GENERIC_BUG_RELATIVE_POINTERS if X86_64
322b93a531eSJan Beulich
323b93a531eSJan Beulichconfig GENERIC_BUG_RELATIVE_POINTERS
324b93a531eSJan Beulich	bool
3258d5fffb9SSam Ravnborg
3268d5fffb9SSam Ravnborgconfig ARCH_MAY_HAVE_PC_FDC
3273120e25eSJan Beulich	def_bool y
3283120e25eSJan Beulich	depends on ISA_DMA_API
3298d5fffb9SSam Ravnborg
3301032c0baSSam Ravnborgconfig GENERIC_CALIBRATE_DELAY
3311032c0baSSam Ravnborg	def_bool y
3321032c0baSSam Ravnborg
3339a0b8415Svenkatesh.pallipadi@intel.comconfig ARCH_HAS_CPU_RELAX
3349a0b8415Svenkatesh.pallipadi@intel.com	def_bool y
3358d5fffb9SSam Ravnborg
336316d097cSDave Hansenconfig ARCH_HAS_FILTER_PGPROT
337316d097cSDave Hansen	def_bool y
338316d097cSDave Hansen
339801e4062SJohannes Bergconfig ARCH_HIBERNATION_POSSIBLE
340801e4062SJohannes Berg	def_bool y
341801e4062SJohannes Berg
342d7109fe3SAndy Shevchenkoconfig ARCH_NR_GPIO
343d7109fe3SAndy Shevchenko	int
344d7109fe3SAndy Shevchenko	default 1024 if X86_64
345d7109fe3SAndy Shevchenko	default 512
346d7109fe3SAndy Shevchenko
347f4cb5700SJohannes Bergconfig ARCH_SUSPEND_POSSIBLE
348f4cb5700SJohannes Berg	def_bool y
349f4cb5700SJohannes Berg
35053313b2cSSteve Capperconfig ARCH_WANT_GENERAL_HUGETLB
35153313b2cSSteve Capper	def_bool y
35253313b2cSSteve Capper
3538d5fffb9SSam Ravnborgconfig AUDIT_ARCH
354e0fd24a3SJan Beulich	def_bool y if X86_64
3558d5fffb9SSam Ravnborg
356d6f2d75aSAndrey Ryabininconfig KASAN_SHADOW_OFFSET
357d6f2d75aSAndrey Ryabinin	hex
358d6f2d75aSAndrey Ryabinin	depends on KASAN
359d6f2d75aSAndrey Ryabinin	default 0xdffffc0000000000
360d6f2d75aSAndrey Ryabinin
36169575d38SShane Wangconfig HAVE_INTEL_TXT
36269575d38SShane Wang	def_bool y
3636ea30386SKees Cook	depends on INTEL_IOMMU && ACPI
36469575d38SShane Wang
3656b0c3d44SSam Ravnborgconfig X86_32_SMP
3666b0c3d44SSam Ravnborg	def_bool y
3676b0c3d44SSam Ravnborg	depends on X86_32 && SMP
3686b0c3d44SSam Ravnborg
3696b0c3d44SSam Ravnborgconfig X86_64_SMP
3706b0c3d44SSam Ravnborg	def_bool y
3716b0c3d44SSam Ravnborg	depends on X86_64 && SMP
3726b0c3d44SSam Ravnborg
3732b144498SSrikar Dronamrajuconfig ARCH_SUPPORTS_UPROBES
3742b144498SSrikar Dronamraju	def_bool y
3752b144498SSrikar Dronamraju
376d20642f0SRob Herringconfig FIX_EARLYCON_MEM
377d20642f0SRob Herring	def_bool y
378d20642f0SRob Herring
37994d49eb3SKirill A. Shutemovconfig DYNAMIC_PHYSICAL_MASK
38094d49eb3SKirill A. Shutemov	bool
38194d49eb3SKirill A. Shutemov
38298233368SKirill A. Shutemovconfig PGTABLE_LEVELS
38398233368SKirill A. Shutemov	int
38477ef56e4SKirill A. Shutemov	default 5 if X86_5LEVEL
38598233368SKirill A. Shutemov	default 4 if X86_64
38698233368SKirill A. Shutemov	default 3 if X86_PAE
38798233368SKirill A. Shutemov	default 2
38898233368SKirill A. Shutemov
3892a61f474SMasahiro Yamadaconfig CC_HAS_SANE_STACKPROTECTOR
3902a61f474SMasahiro Yamada	bool
3912a61f474SMasahiro Yamada	default $(success,$(srctree)/scripts/gcc-x86_64-has-stack-protector.sh $(CC)) if 64BIT
3922a61f474SMasahiro Yamada	default $(success,$(srctree)/scripts/gcc-x86_32-has-stack-protector.sh $(CC))
3932a61f474SMasahiro Yamada	help
3942a61f474SMasahiro Yamada	   We have to make sure stack protector is unconditionally disabled if
3953fb0fdb3SAndy Lutomirski	   the compiler produces broken code or if it does not let us control
3963fb0fdb3SAndy Lutomirski	   the segment on 32-bit kernels.
3972a61f474SMasahiro Yamada
398506f1d07SSam Ravnborgmenu "Processor type and features"
399506f1d07SSam Ravnborg
400506f1d07SSam Ravnborgconfig SMP
401506f1d07SSam Ravnborg	bool "Symmetric multi-processing support"
402a7f7f624SMasahiro Yamada	help
403506f1d07SSam Ravnborg	  This enables support for systems with more than one CPU. If you have
4044a474157SRobert Graffham	  a system with only one CPU, say N. If you have a system with more
4054a474157SRobert Graffham	  than one CPU, say Y.
406506f1d07SSam Ravnborg
4074a474157SRobert Graffham	  If you say N here, the kernel will run on uni- and multiprocessor
408506f1d07SSam Ravnborg	  machines, but will use only one CPU of a multiprocessor machine. If
409506f1d07SSam Ravnborg	  you say Y here, the kernel will run on many, but not all,
4104a474157SRobert Graffham	  uniprocessor machines. On a uniprocessor machine, the kernel
411506f1d07SSam Ravnborg	  will run faster if you say N here.
412506f1d07SSam Ravnborg
413506f1d07SSam Ravnborg	  Note that if you say Y here and choose architecture "586" or
414506f1d07SSam Ravnborg	  "Pentium" under "Processor family", the kernel will not work on 486
415506f1d07SSam Ravnborg	  architectures. Similarly, multiprocessor kernels for the "PPro"
416506f1d07SSam Ravnborg	  architecture may not work on all Pentium based boards.
417506f1d07SSam Ravnborg
418506f1d07SSam Ravnborg	  People using multiprocessor machines who say Y here should also say
419506f1d07SSam Ravnborg	  Y to "Enhanced Real Time Clock Support", below. The "Advanced Power
420506f1d07SSam Ravnborg	  Management" code will be disabled if you say Y here.
421506f1d07SSam Ravnborg
422cb1aaebeSMauro Carvalho Chehab	  See also <file:Documentation/x86/i386/IO-APIC.rst>,
4234f4cfa6cSMauro Carvalho Chehab	  <file:Documentation/admin-guide/lockup-watchdogs.rst> and the SMP-HOWTO available at
424506f1d07SSam Ravnborg	  <http://www.tldp.org/docs.html#howto>.
425506f1d07SSam Ravnborg
426506f1d07SSam Ravnborg	  If you don't know what to do here, say N.
427506f1d07SSam Ravnborg
4289def39beSJosh Triplettconfig X86_FEATURE_NAMES
4299def39beSJosh Triplett	bool "Processor feature human-readable names" if EMBEDDED
4309def39beSJosh Triplett	default y
431a7f7f624SMasahiro Yamada	help
4329def39beSJosh Triplett	  This option compiles in a table of x86 feature bits and corresponding
4339def39beSJosh Triplett	  names.  This is required to support /proc/cpuinfo and a few kernel
4349def39beSJosh Triplett	  messages.  You can disable this to save space, at the expense of
4359def39beSJosh Triplett	  making those few kernel messages show numeric feature bits instead.
4369def39beSJosh Triplett
4379def39beSJosh Triplett	  If in doubt, say Y.
4389def39beSJosh Triplett
43906cd9a7dSYinghai Luconfig X86_X2APIC
44006cd9a7dSYinghai Lu	bool "Support x2apic"
44119e3d60dSJan Kiszka	depends on X86_LOCAL_APIC && X86_64 && (IRQ_REMAP || HYPERVISOR_GUEST)
442a7f7f624SMasahiro Yamada	help
44306cd9a7dSYinghai Lu	  This enables x2apic support on CPUs that have this feature.
44406cd9a7dSYinghai Lu
44506cd9a7dSYinghai Lu	  This allows 32-bit apic IDs (so it can support very large systems),
44606cd9a7dSYinghai Lu	  and accesses the local apic via MSRs not via mmio.
44706cd9a7dSYinghai Lu
44806cd9a7dSYinghai Lu	  If you don't know what to do here, say N.
44906cd9a7dSYinghai Lu
4506695c85bSYinghai Luconfig X86_MPPARSE
4514590d98fSAndy Shevchenko	bool "Enable MPS table" if ACPI
4527a527688SJan Beulich	default y
4535ab74722SIngo Molnar	depends on X86_LOCAL_APIC
454a7f7f624SMasahiro Yamada	help
4556695c85bSYinghai Lu	  For old smp systems that do not have proper acpi support. Newer systems
4566695c85bSYinghai Lu	  (esp with 64bit cpus) with acpi support, MADT and DSDT will override it
4576695c85bSYinghai Lu
458ddd70cf9SJun Nakajimaconfig GOLDFISH
459ddd70cf9SJun Nakajima	def_bool y
460ddd70cf9SJun Nakajima	depends on X86_GOLDFISH
461ddd70cf9SJun Nakajima
46276b04384SDavid Woodhouseconfig RETPOLINE
46376b04384SDavid Woodhouse	bool "Avoid speculative indirect branches in kernel"
46476b04384SDavid Woodhouse	default y
46576b04384SDavid Woodhouse	help
46676b04384SDavid Woodhouse	  Compile kernel with the retpoline compiler options to guard against
46776b04384SDavid Woodhouse	  kernel-to-user data leaks by avoiding speculative indirect
46876b04384SDavid Woodhouse	  branches. Requires a compiler with -mindirect-branch=thunk-extern
46976b04384SDavid Woodhouse	  support for full protection. The kernel may run slower.
47076b04384SDavid Woodhouse
471e463a09aSPeter Zijlstraconfig CC_HAS_SLS
472e463a09aSPeter Zijlstra	def_bool $(cc-option,-mharden-sls=all)
473e463a09aSPeter Zijlstra
474e463a09aSPeter Zijlstraconfig SLS
475e463a09aSPeter Zijlstra	bool "Mitigate Straight-Line-Speculation"
476e463a09aSPeter Zijlstra	depends on CC_HAS_SLS && X86_64
477e463a09aSPeter Zijlstra	default n
478e463a09aSPeter Zijlstra	help
479e463a09aSPeter Zijlstra	  Compile the kernel with straight-line-speculation options to guard
480e463a09aSPeter Zijlstra	  against straight line speculation. The kernel image might be slightly
481e463a09aSPeter Zijlstra	  larger.
482e463a09aSPeter Zijlstra
483e6d42931SJohannes Weinerconfig X86_CPU_RESCTRL
484e6d42931SJohannes Weiner	bool "x86 CPU resource control support"
4856fe07ce3SBabu Moger	depends on X86 && (CPU_SUP_INTEL || CPU_SUP_AMD)
48659fe5a77SThomas Gleixner	select KERNFS
487e79f15a4SChen Yu	select PROC_CPU_RESCTRL		if PROC_FS
48878e99b4aSFenghua Yu	help
489e6d42931SJohannes Weiner	  Enable x86 CPU resource control support.
4906fe07ce3SBabu Moger
4916fe07ce3SBabu Moger	  Provide support for the allocation and monitoring of system resources
4926fe07ce3SBabu Moger	  usage by the CPU.
4936fe07ce3SBabu Moger
4946fe07ce3SBabu Moger	  Intel calls this Intel Resource Director Technology
4956fe07ce3SBabu Moger	  (Intel(R) RDT). More information about RDT can be found in the
4966fe07ce3SBabu Moger	  Intel x86 Architecture Software Developer Manual.
4976fe07ce3SBabu Moger
4986fe07ce3SBabu Moger	  AMD calls this AMD Platform Quality of Service (AMD QoS).
4996fe07ce3SBabu Moger	  More information about AMD QoS can be found in the AMD64 Technology
5006fe07ce3SBabu Moger	  Platform Quality of Service Extensions manual.
50178e99b4aSFenghua Yu
50278e99b4aSFenghua Yu	  Say N if unsure.
50378e99b4aSFenghua Yu
5048425091fSRavikiran G Thirumalaiif X86_32
505a0d0bb4dSRandy Dunlapconfig X86_BIGSMP
506a0d0bb4dSRandy Dunlap	bool "Support for big SMP systems with more than 8 CPUs"
507a0d0bb4dSRandy Dunlap	depends on SMP
508a7f7f624SMasahiro Yamada	help
509e133f6eaSRandy Dunlap	  This option is needed for the systems that have more than 8 CPUs.
510a0d0bb4dSRandy Dunlap
511c5c606d9SRavikiran G Thirumalaiconfig X86_EXTENDED_PLATFORM
512c5c606d9SRavikiran G Thirumalai	bool "Support for extended (non-PC) x86 platforms"
513c5c606d9SRavikiran G Thirumalai	default y
514a7f7f624SMasahiro Yamada	help
51506ac8346SIngo Molnar	  If you disable this option then the kernel will only support
51606ac8346SIngo Molnar	  standard PC platforms. (which covers the vast majority of
51706ac8346SIngo Molnar	  systems out there.)
51806ac8346SIngo Molnar
5198425091fSRavikiran G Thirumalai	  If you enable this option then you'll be able to select support
5208425091fSRavikiran G Thirumalai	  for the following (non-PC) 32 bit x86 platforms:
521cb7b8023SBen Hutchings		Goldfish (Android emulator)
5228425091fSRavikiran G Thirumalai		AMD Elan
5238425091fSRavikiran G Thirumalai		RDC R-321x SoC
5248425091fSRavikiran G Thirumalai		SGI 320/540 (Visual Workstation)
52583125a3aSAlessandro Rubini		STA2X11-based (e.g. Northville)
5263f4110a4SThomas Gleixner		Moorestown MID devices
52706ac8346SIngo Molnar
52806ac8346SIngo Molnar	  If you have one of these systems, or if you want to build a
52906ac8346SIngo Molnar	  generic distribution kernel, say Y here - otherwise say N.
5308425091fSRavikiran G Thirumalaiendif
53106ac8346SIngo Molnar
5328425091fSRavikiran G Thirumalaiif X86_64
5338425091fSRavikiran G Thirumalaiconfig X86_EXTENDED_PLATFORM
5348425091fSRavikiran G Thirumalai	bool "Support for extended (non-PC) x86 platforms"
5358425091fSRavikiran G Thirumalai	default y
536a7f7f624SMasahiro Yamada	help
5378425091fSRavikiran G Thirumalai	  If you disable this option then the kernel will only support
5388425091fSRavikiran G Thirumalai	  standard PC platforms. (which covers the vast majority of
5398425091fSRavikiran G Thirumalai	  systems out there.)
5408425091fSRavikiran G Thirumalai
5418425091fSRavikiran G Thirumalai	  If you enable this option then you'll be able to select support
5428425091fSRavikiran G Thirumalai	  for the following (non-PC) 64 bit x86 platforms:
54344b111b5SSteffen Persvold		Numascale NumaChip
5448425091fSRavikiran G Thirumalai		ScaleMP vSMP
5458425091fSRavikiran G Thirumalai		SGI Ultraviolet
5468425091fSRavikiran G Thirumalai
5478425091fSRavikiran G Thirumalai	  If you have one of these systems, or if you want to build a
5488425091fSRavikiran G Thirumalai	  generic distribution kernel, say Y here - otherwise say N.
5498425091fSRavikiran G Thirumalaiendif
550c5c606d9SRavikiran G Thirumalai# This is an alphabetically sorted list of 64 bit extended platforms
551c5c606d9SRavikiran G Thirumalai# Please maintain the alphabetic order if and when there are additions
55244b111b5SSteffen Persvoldconfig X86_NUMACHIP
55344b111b5SSteffen Persvold	bool "Numascale NumaChip"
55444b111b5SSteffen Persvold	depends on X86_64
55544b111b5SSteffen Persvold	depends on X86_EXTENDED_PLATFORM
55644b111b5SSteffen Persvold	depends on NUMA
55744b111b5SSteffen Persvold	depends on SMP
55844b111b5SSteffen Persvold	depends on X86_X2APIC
559f9726bfdSDaniel J Blueman	depends on PCI_MMCONFIG
560a7f7f624SMasahiro Yamada	help
56144b111b5SSteffen Persvold	  Adds support for Numascale NumaChip large-SMP systems. Needed to
56244b111b5SSteffen Persvold	  enable more than ~168 cores.
56344b111b5SSteffen Persvold	  If you don't have one of these, you should say N here.
56403b48632SNick Piggin
5656a48565eSIngo Molnarconfig X86_VSMP
566c5c606d9SRavikiran G Thirumalai	bool "ScaleMP vSMP"
5676276a074SBorislav Petkov	select HYPERVISOR_GUEST
5686a48565eSIngo Molnar	select PARAVIRT
5696a48565eSIngo Molnar	depends on X86_64 && PCI
570c5c606d9SRavikiran G Thirumalai	depends on X86_EXTENDED_PLATFORM
571ead91d4bSShai Fultheim	depends on SMP
572a7f7f624SMasahiro Yamada	help
5736a48565eSIngo Molnar	  Support for ScaleMP vSMP systems.  Say 'Y' here if this kernel is
5746a48565eSIngo Molnar	  supposed to run on these EM64T-based machines.  Only choose this option
5756a48565eSIngo Molnar	  if you have one of these machines.
5766a48565eSIngo Molnar
577c5c606d9SRavikiran G Thirumalaiconfig X86_UV
578c5c606d9SRavikiran G Thirumalai	bool "SGI Ultraviolet"
579c5c606d9SRavikiran G Thirumalai	depends on X86_64
580c5c606d9SRavikiran G Thirumalai	depends on X86_EXTENDED_PLATFORM
58154c28d29SJack Steiner	depends on NUMA
5821ecb4ae5SAndrew Morton	depends on EFI
583c2209ea5SIngo Molnar	depends on KEXEC_CORE
5849d6c26e7SSuresh Siddha	depends on X86_X2APIC
5851222e564SIngo Molnar	depends on PCI
586a7f7f624SMasahiro Yamada	help
587c5c606d9SRavikiran G Thirumalai	  This option is needed in order to support SGI Ultraviolet systems.
588c5c606d9SRavikiran G Thirumalai	  If you don't have one of these, you should say N here.
589c5c606d9SRavikiran G Thirumalai
590c5c606d9SRavikiran G Thirumalai# Following is an alphabetically sorted list of 32 bit extended platforms
591c5c606d9SRavikiran G Thirumalai# Please maintain the alphabetic order if and when there are additions
592506f1d07SSam Ravnborg
593ddd70cf9SJun Nakajimaconfig X86_GOLDFISH
594ddd70cf9SJun Nakajima	bool "Goldfish (Virtual Platform)"
595cb7b8023SBen Hutchings	depends on X86_EXTENDED_PLATFORM
596a7f7f624SMasahiro Yamada	help
597ddd70cf9SJun Nakajima	 Enable support for the Goldfish virtual platform used primarily
598ddd70cf9SJun Nakajima	 for Android development. Unless you are building for the Android
599ddd70cf9SJun Nakajima	 Goldfish emulator say N here.
600ddd70cf9SJun Nakajima
601c751e17bSThomas Gleixnerconfig X86_INTEL_CE
602c751e17bSThomas Gleixner	bool "CE4100 TV platform"
603c751e17bSThomas Gleixner	depends on PCI
604c751e17bSThomas Gleixner	depends on PCI_GODIRECT
6056084a6e2SJiang Liu	depends on X86_IO_APIC
606c751e17bSThomas Gleixner	depends on X86_32
607c751e17bSThomas Gleixner	depends on X86_EXTENDED_PLATFORM
60837bc9f50SDirk Brandewie	select X86_REBOOTFIXUPS
609da6b737bSSebastian Andrzej Siewior	select OF
610da6b737bSSebastian Andrzej Siewior	select OF_EARLY_FLATTREE
611a7f7f624SMasahiro Yamada	help
612c751e17bSThomas Gleixner	  Select for the Intel CE media processor (CE4100) SOC.
613c751e17bSThomas Gleixner	  This option compiles in support for the CE4100 SOC for settop
614c751e17bSThomas Gleixner	  boxes and media devices.
615c751e17bSThomas Gleixner
6164cb9b00fSDavid Cohenconfig X86_INTEL_MID
61743605ef1SAlan Cox	bool "Intel MID platform support"
61843605ef1SAlan Cox	depends on X86_EXTENDED_PLATFORM
619edc6bc78SDavid Cohen	depends on X86_PLATFORM_DEVICES
6201ea7c673SAlan Cox	depends on PCI
6213fda5bb4SAndy Shevchenko	depends on X86_64 || (PCI_GOANY && X86_32)
6221ea7c673SAlan Cox	depends on X86_IO_APIC
6234cb9b00fSDavid Cohen	select I2C
6247c9c3a1eSAlan Cox	select DW_APB_TIMER
62554b34aa0SMika Westerberg	select INTEL_SCU_PCI
626a7f7f624SMasahiro Yamada	help
6274cb9b00fSDavid Cohen	  Select to build a kernel capable of supporting Intel MID (Mobile
6284cb9b00fSDavid Cohen	  Internet Device) platform systems which do not have the PCI legacy
6294cb9b00fSDavid Cohen	  interfaces. If you are building for a PC class system say N here.
6301ea7c673SAlan Cox
6314cb9b00fSDavid Cohen	  Intel MID platforms are based on an Intel processor and chipset which
6324cb9b00fSDavid Cohen	  consume less power than most of the x86 derivatives.
63343605ef1SAlan Cox
6348bbc2a13SBryan O'Donoghueconfig X86_INTEL_QUARK
6358bbc2a13SBryan O'Donoghue	bool "Intel Quark platform support"
6368bbc2a13SBryan O'Donoghue	depends on X86_32
6378bbc2a13SBryan O'Donoghue	depends on X86_EXTENDED_PLATFORM
6388bbc2a13SBryan O'Donoghue	depends on X86_PLATFORM_DEVICES
6398bbc2a13SBryan O'Donoghue	depends on X86_TSC
6408bbc2a13SBryan O'Donoghue	depends on PCI
6418bbc2a13SBryan O'Donoghue	depends on PCI_GOANY
6428bbc2a13SBryan O'Donoghue	depends on X86_IO_APIC
6438bbc2a13SBryan O'Donoghue	select IOSF_MBI
6448bbc2a13SBryan O'Donoghue	select INTEL_IMR
6459ab6eb51SAndy Shevchenko	select COMMON_CLK
646a7f7f624SMasahiro Yamada	help
6478bbc2a13SBryan O'Donoghue	  Select to include support for Quark X1000 SoC.
6488bbc2a13SBryan O'Donoghue	  Say Y here if you have a Quark based system such as the Arduino
6498bbc2a13SBryan O'Donoghue	  compatible Intel Galileo.
6508bbc2a13SBryan O'Donoghue
6513d48aab1SMika Westerbergconfig X86_INTEL_LPSS
6523d48aab1SMika Westerberg	bool "Intel Low Power Subsystem Support"
6535962dd22SSinan Kaya	depends on X86 && ACPI && PCI
6543d48aab1SMika Westerberg	select COMMON_CLK
6550f531431SMathias Nyman	select PINCTRL
656eebb3e8dSAndy Shevchenko	select IOSF_MBI
657a7f7f624SMasahiro Yamada	help
6583d48aab1SMika Westerberg	  Select to build support for Intel Low Power Subsystem such as
6593d48aab1SMika Westerberg	  found on Intel Lynxpoint PCH. Selecting this option enables
6600f531431SMathias Nyman	  things like clock tree (common clock framework) and pincontrol
6610f531431SMathias Nyman	  which are needed by the LPSS peripheral drivers.
6623d48aab1SMika Westerberg
66392082a88SKen Xueconfig X86_AMD_PLATFORM_DEVICE
66492082a88SKen Xue	bool "AMD ACPI2Platform devices support"
66592082a88SKen Xue	depends on ACPI
66692082a88SKen Xue	select COMMON_CLK
66792082a88SKen Xue	select PINCTRL
668a7f7f624SMasahiro Yamada	help
66992082a88SKen Xue	  Select to interpret AMD specific ACPI device to platform device
67092082a88SKen Xue	  such as I2C, UART, GPIO found on AMD Carrizo and later chipsets.
67192082a88SKen Xue	  I2C and UART depend on COMMON_CLK to set clock. GPIO driver is
67292082a88SKen Xue	  implemented under PINCTRL subsystem.
67392082a88SKen Xue
674ced3ce76SDavid E. Boxconfig IOSF_MBI
675ced3ce76SDavid E. Box	tristate "Intel SoC IOSF Sideband support for SoC platforms"
676ced3ce76SDavid E. Box	depends on PCI
677a7f7f624SMasahiro Yamada	help
678ced3ce76SDavid E. Box	  This option enables sideband register access support for Intel SoC
679ced3ce76SDavid E. Box	  platforms. On these platforms the IOSF sideband is used in lieu of
680ced3ce76SDavid E. Box	  MSR's for some register accesses, mostly but not limited to thermal
681ced3ce76SDavid E. Box	  and power. Drivers may query the availability of this device to
682ced3ce76SDavid E. Box	  determine if they need the sideband in order to work on these
683ced3ce76SDavid E. Box	  platforms. The sideband is available on the following SoC products.
684ced3ce76SDavid E. Box	  This list is not meant to be exclusive.
685ced3ce76SDavid E. Box	   - BayTrail
686ced3ce76SDavid E. Box	   - Braswell
687ced3ce76SDavid E. Box	   - Quark
688ced3ce76SDavid E. Box
689ced3ce76SDavid E. Box	  You should say Y if you are running a kernel on one of these SoC's.
690ced3ce76SDavid E. Box
691ed2226bdSDavid E. Boxconfig IOSF_MBI_DEBUG
692ed2226bdSDavid E. Box	bool "Enable IOSF sideband access through debugfs"
693ed2226bdSDavid E. Box	depends on IOSF_MBI && DEBUG_FS
694a7f7f624SMasahiro Yamada	help
695ed2226bdSDavid E. Box	  Select this option to expose the IOSF sideband access registers (MCR,
696ed2226bdSDavid E. Box	  MDR, MCRX) through debugfs to write and read register information from
697ed2226bdSDavid E. Box	  different units on the SoC. This is most useful for obtaining device
698ed2226bdSDavid E. Box	  state information for debug and analysis. As this is a general access
699ed2226bdSDavid E. Box	  mechanism, users of this option would have specific knowledge of the
700ed2226bdSDavid E. Box	  device they want to access.
701ed2226bdSDavid E. Box
702ed2226bdSDavid E. Box	  If you don't require the option or are in doubt, say N.
703ed2226bdSDavid E. Box
704c5c606d9SRavikiran G Thirumalaiconfig X86_RDC321X
705c5c606d9SRavikiran G Thirumalai	bool "RDC R-321x SoC"
706506f1d07SSam Ravnborg	depends on X86_32
707c5c606d9SRavikiran G Thirumalai	depends on X86_EXTENDED_PLATFORM
708c5c606d9SRavikiran G Thirumalai	select M486
709c5c606d9SRavikiran G Thirumalai	select X86_REBOOTFIXUPS
710a7f7f624SMasahiro Yamada	help
711c5c606d9SRavikiran G Thirumalai	  This option is needed for RDC R-321x system-on-chip, also known
712c5c606d9SRavikiran G Thirumalai	  as R-8610-(G).
713c5c606d9SRavikiran G Thirumalai	  If you don't have one of these chips, you should say N here.
714c5c606d9SRavikiran G Thirumalai
715e0c7ae37SIngo Molnarconfig X86_32_NON_STANDARD
7169c398017SIngo Molnar	bool "Support non-standard 32-bit SMP architectures"
7179c398017SIngo Molnar	depends on X86_32 && SMP
718c5c606d9SRavikiran G Thirumalai	depends on X86_EXTENDED_PLATFORM
719a7f7f624SMasahiro Yamada	help
720b5660ba7SH. Peter Anvin	  This option compiles in the bigsmp and STA2X11 default
721b5660ba7SH. Peter Anvin	  subarchitectures.  It is intended for a generic binary
722b5660ba7SH. Peter Anvin	  kernel. If you select them all, kernel will probe it one by
723b5660ba7SH. Peter Anvin	  one and will fallback to default.
724d49c4288SYinghai Lu
725c5c606d9SRavikiran G Thirumalai# Alphabetically sorted list of Non standard 32 bit platforms
726d49c4288SYinghai Lu
727d949f36fSLinus Torvaldsconfig X86_SUPPORTS_MEMORY_FAILURE
7286fc108a0SJan Beulich	def_bool y
729d949f36fSLinus Torvalds	# MCE code calls memory_failure():
730d949f36fSLinus Torvalds	depends on X86_MCE
731d949f36fSLinus Torvalds	# On 32-bit this adds too big of NODES_SHIFT and we run out of page flags:
732d949f36fSLinus Torvalds	# On 32-bit SPARSEMEM adds too big of SECTIONS_WIDTH:
733d949f36fSLinus Torvalds	depends on X86_64 || !SPARSEMEM
734d949f36fSLinus Torvalds	select ARCH_SUPPORTS_MEMORY_FAILURE
735d949f36fSLinus Torvalds
73683125a3aSAlessandro Rubiniconfig STA2X11
73783125a3aSAlessandro Rubini	bool "STA2X11 Companion Chip Support"
73883125a3aSAlessandro Rubini	depends on X86_32_NON_STANDARD && PCI
73983125a3aSAlessandro Rubini	select SWIOTLB
74083125a3aSAlessandro Rubini	select MFD_STA2X11
7410145071bSLinus Walleij	select GPIOLIB
742a7f7f624SMasahiro Yamada	help
74383125a3aSAlessandro Rubini	  This adds support for boards based on the STA2X11 IO-Hub,
74483125a3aSAlessandro Rubini	  a.k.a. "ConneXt". The chip is used in place of the standard
74583125a3aSAlessandro Rubini	  PC chipset, so all "standard" peripherals are missing. If this
74683125a3aSAlessandro Rubini	  option is selected the kernel will still be able to boot on
74783125a3aSAlessandro Rubini	  standard PC machines.
74883125a3aSAlessandro Rubini
74982148d1dSShérabconfig X86_32_IRIS
75082148d1dSShérab	tristate "Eurobraille/Iris poweroff module"
75182148d1dSShérab	depends on X86_32
752a7f7f624SMasahiro Yamada	help
75382148d1dSShérab	  The Iris machines from EuroBraille do not have APM or ACPI support
75482148d1dSShérab	  to shut themselves down properly.  A special I/O sequence is
75582148d1dSShérab	  needed to do so, which is what this module does at
75682148d1dSShérab	  kernel shutdown.
75782148d1dSShérab
75882148d1dSShérab	  This is only for Iris machines from EuroBraille.
75982148d1dSShérab
76082148d1dSShérab	  If unused, say N.
76182148d1dSShérab
762ae1e9130SIngo Molnarconfig SCHED_OMIT_FRAME_POINTER
7633c2362e6SHarvey Harrison	def_bool y
7643c2362e6SHarvey Harrison	prompt "Single-depth WCHAN output"
765a87d0914SKen Chen	depends on X86
766a7f7f624SMasahiro Yamada	help
767506f1d07SSam Ravnborg	  Calculate simpler /proc/<PID>/wchan values. If this option
768506f1d07SSam Ravnborg	  is disabled then wchan values will recurse back to the
769506f1d07SSam Ravnborg	  caller function. This provides more accurate wchan values,
770506f1d07SSam Ravnborg	  at the expense of slightly more scheduling overhead.
771506f1d07SSam Ravnborg
772506f1d07SSam Ravnborg	  If in doubt, say "Y".
773506f1d07SSam Ravnborg
7746276a074SBorislav Petkovmenuconfig HYPERVISOR_GUEST
7756276a074SBorislav Petkov	bool "Linux guest support"
776a7f7f624SMasahiro Yamada	help
7776276a074SBorislav Petkov	  Say Y here to enable options for running Linux under various hyper-
7786276a074SBorislav Petkov	  visors. This option enables basic hypervisor detection and platform
7796276a074SBorislav Petkov	  setup.
780506f1d07SSam Ravnborg
7816276a074SBorislav Petkov	  If you say N, all options in this submenu will be skipped and
7826276a074SBorislav Petkov	  disabled, and Linux guest support won't be built in.
783506f1d07SSam Ravnborg
7846276a074SBorislav Petkovif HYPERVISOR_GUEST
785506f1d07SSam Ravnborg
786e61bd94aSEduardo Pereira Habkostconfig PARAVIRT
787e61bd94aSEduardo Pereira Habkost	bool "Enable paravirtualization code"
788a0e2bf7cSJuergen Gross	depends on HAVE_STATIC_CALL
789a7f7f624SMasahiro Yamada	help
790e61bd94aSEduardo Pereira Habkost	  This changes the kernel so it can modify itself when it is run
791e61bd94aSEduardo Pereira Habkost	  under a hypervisor, potentially improving performance significantly
792e61bd94aSEduardo Pereira Habkost	  over full virtualization.  However, when run without a hypervisor
793e61bd94aSEduardo Pereira Habkost	  the kernel is theoretically slower and slightly larger.
794e61bd94aSEduardo Pereira Habkost
795c00a280aSJuergen Grossconfig PARAVIRT_XXL
796c00a280aSJuergen Gross	bool
797c00a280aSJuergen Gross
7986276a074SBorislav Petkovconfig PARAVIRT_DEBUG
7996276a074SBorislav Petkov	bool "paravirt-ops debugging"
8006276a074SBorislav Petkov	depends on PARAVIRT && DEBUG_KERNEL
801a7f7f624SMasahiro Yamada	help
8026276a074SBorislav Petkov	  Enable to debug paravirt_ops internals.  Specifically, BUG if
8036276a074SBorislav Petkov	  a paravirt_op is missing when it is called.
8046276a074SBorislav Petkov
805b4ecc126SJeremy Fitzhardingeconfig PARAVIRT_SPINLOCKS
806b4ecc126SJeremy Fitzhardinge	bool "Paravirtualization layer for spinlocks"
8076ea30386SKees Cook	depends on PARAVIRT && SMP
808a7f7f624SMasahiro Yamada	help
809b4ecc126SJeremy Fitzhardinge	  Paravirtualized spinlocks allow a pvops backend to replace the
810b4ecc126SJeremy Fitzhardinge	  spinlock implementation with something virtualization-friendly
811b4ecc126SJeremy Fitzhardinge	  (for example, block the virtual CPU rather than spinning).
812b4ecc126SJeremy Fitzhardinge
8134c4e4f61SRaghavendra K T	  It has a minimal impact on native kernels and gives a nice performance
8144c4e4f61SRaghavendra K T	  benefit on paravirtualized KVM / Xen kernels.
815b4ecc126SJeremy Fitzhardinge
8164c4e4f61SRaghavendra K T	  If you are unsure how to answer this question, answer Y.
817b4ecc126SJeremy Fitzhardinge
818ecca2502SZhao Yakuiconfig X86_HV_CALLBACK_VECTOR
819ecca2502SZhao Yakui	def_bool n
820ecca2502SZhao Yakui
8216276a074SBorislav Petkovsource "arch/x86/xen/Kconfig"
8226276a074SBorislav Petkov
8236276a074SBorislav Petkovconfig KVM_GUEST
8246276a074SBorislav Petkov	bool "KVM Guest support (including kvmclock)"
8256276a074SBorislav Petkov	depends on PARAVIRT
8266276a074SBorislav Petkov	select PARAVIRT_CLOCK
827a1c4423bSMarcelo Tosatti	select ARCH_CPUIDLE_HALTPOLL
828b1d40575SVitaly Kuznetsov	select X86_HV_CALLBACK_VECTOR
8296276a074SBorislav Petkov	default y
830a7f7f624SMasahiro Yamada	help
8316276a074SBorislav Petkov	  This option enables various optimizations for running under the KVM
8326276a074SBorislav Petkov	  hypervisor. It includes a paravirtualized clock, so that instead
8336276a074SBorislav Petkov	  of relying on a PIT (or probably other) emulation by the
8346276a074SBorislav Petkov	  underlying device model, the host provides the guest with
8356276a074SBorislav Petkov	  timing infrastructure such as time of day, and system time
8366276a074SBorislav Petkov
837a1c4423bSMarcelo Tosatticonfig ARCH_CPUIDLE_HALTPOLL
838a1c4423bSMarcelo Tosatti	def_bool n
839a1c4423bSMarcelo Tosatti	prompt "Disable host haltpoll when loading haltpoll driver"
840a1c4423bSMarcelo Tosatti	help
841a1c4423bSMarcelo Tosatti	  If virtualized under KVM, disable host haltpoll.
842a1c4423bSMarcelo Tosatti
8437733607fSMaran Wilsonconfig PVH
8447733607fSMaran Wilson	bool "Support for running PVH guests"
845a7f7f624SMasahiro Yamada	help
8467733607fSMaran Wilson	  This option enables the PVH entry point for guest virtual machines
8477733607fSMaran Wilson	  as specified in the x86/HVM direct boot ABI.
8487733607fSMaran Wilson
8496276a074SBorislav Petkovconfig PARAVIRT_TIME_ACCOUNTING
8506276a074SBorislav Petkov	bool "Paravirtual steal time accounting"
8516276a074SBorislav Petkov	depends on PARAVIRT
852a7f7f624SMasahiro Yamada	help
8536276a074SBorislav Petkov	  Select this option to enable fine granularity task steal time
8546276a074SBorislav Petkov	  accounting. Time spent executing other tasks in parallel with
8556276a074SBorislav Petkov	  the current vCPU is discounted from the vCPU power. To account for
8566276a074SBorislav Petkov	  that, there can be a small performance impact.
8576276a074SBorislav Petkov
8586276a074SBorislav Petkov	  If in doubt, say N here.
8596276a074SBorislav Petkov
8607af192c9SGerd Hoffmannconfig PARAVIRT_CLOCK
8617af192c9SGerd Hoffmann	bool
8627af192c9SGerd Hoffmann
8634a362601SJan Kiszkaconfig JAILHOUSE_GUEST
8644a362601SJan Kiszka	bool "Jailhouse non-root cell support"
865abde587bSArnd Bergmann	depends on X86_64 && PCI
86687e65d05SJan Kiszka	select X86_PM_TIMER
867a7f7f624SMasahiro Yamada	help
8684a362601SJan Kiszka	  This option allows to run Linux as guest in a Jailhouse non-root
8694a362601SJan Kiszka	  cell. You can leave this option disabled if you only want to start
8704a362601SJan Kiszka	  Jailhouse and run Linux afterwards in the root cell.
8714a362601SJan Kiszka
872ec7972c9SZhao Yakuiconfig ACRN_GUEST
873ec7972c9SZhao Yakui	bool "ACRN Guest support"
874ec7972c9SZhao Yakui	depends on X86_64
875498ad393SZhao Yakui	select X86_HV_CALLBACK_VECTOR
876ec7972c9SZhao Yakui	help
877ec7972c9SZhao Yakui	  This option allows to run Linux as guest in the ACRN hypervisor. ACRN is
878ec7972c9SZhao Yakui	  a flexible, lightweight reference open-source hypervisor, built with
879ec7972c9SZhao Yakui	  real-time and safety-criticality in mind. It is built for embedded
880ec7972c9SZhao Yakui	  IOT with small footprint and real-time features. More details can be
881ec7972c9SZhao Yakui	  found in https://projectacrn.org/.
882ec7972c9SZhao Yakui
8836276a074SBorislav Petkovendif #HYPERVISOR_GUEST
88497349135SJeremy Fitzhardinge
885506f1d07SSam Ravnborgsource "arch/x86/Kconfig.cpu"
886506f1d07SSam Ravnborg
887506f1d07SSam Ravnborgconfig HPET_TIMER
8883c2362e6SHarvey Harrison	def_bool X86_64
889506f1d07SSam Ravnborg	prompt "HPET Timer Support" if X86_32
890a7f7f624SMasahiro Yamada	help
891506f1d07SSam Ravnborg	  Use the IA-PC HPET (High Precision Event Timer) to manage
892506f1d07SSam Ravnborg	  time in preference to the PIT and RTC, if a HPET is
893506f1d07SSam Ravnborg	  present.
894506f1d07SSam Ravnborg	  HPET is the next generation timer replacing legacy 8254s.
895506f1d07SSam Ravnborg	  The HPET provides a stable time base on SMP
896506f1d07SSam Ravnborg	  systems, unlike the TSC, but it is more expensive to access,
8974e7f9df2SMichael S. Tsirkin	  as it is off-chip.  The interface used is documented
8984e7f9df2SMichael S. Tsirkin	  in the HPET spec, revision 1.
899506f1d07SSam Ravnborg
900506f1d07SSam Ravnborg	  You can safely choose Y here.  However, HPET will only be
901506f1d07SSam Ravnborg	  activated if the platform and the BIOS support this feature.
902506f1d07SSam Ravnborg	  Otherwise the 8254 will be used for timing services.
903506f1d07SSam Ravnborg
904506f1d07SSam Ravnborg	  Choose N to continue using the legacy 8254 timer.
905506f1d07SSam Ravnborg
906506f1d07SSam Ravnborgconfig HPET_EMULATE_RTC
9073c2362e6SHarvey Harrison	def_bool y
9083228e1dcSAnand K Mistry	depends on HPET_TIMER && (RTC_DRV_CMOS=m || RTC_DRV_CMOS=y)
909506f1d07SSam Ravnborg
9106a108a14SDavid Rientjes# Mark as expert because too many people got it wrong.
911506f1d07SSam Ravnborg# The code disables itself when not needed.
9127ae9392cSThomas Petazzoniconfig DMI
9137ae9392cSThomas Petazzoni	default y
914cf074402SArd Biesheuvel	select DMI_SCAN_MACHINE_NON_EFI_FALLBACK
9156a108a14SDavid Rientjes	bool "Enable DMI scanning" if EXPERT
916a7f7f624SMasahiro Yamada	help
9177ae9392cSThomas Petazzoni	  Enabled scanning of DMI to identify machine quirks. Say Y
9187ae9392cSThomas Petazzoni	  here unless you have verified that your setup is not
9197ae9392cSThomas Petazzoni	  affected by entries in the DMI blacklist. Required by PNP
9207ae9392cSThomas Petazzoni	  BIOS code.
9217ae9392cSThomas Petazzoni
922506f1d07SSam Ravnborgconfig GART_IOMMU
92338901f1cSAndi Kleen	bool "Old AMD GART IOMMU support"
9242f9237d4SChristoph Hellwig	select DMA_OPS
925a4ce5a48SChristoph Hellwig	select IOMMU_HELPER
926506f1d07SSam Ravnborg	select SWIOTLB
92723ac4ae8SAndreas Herrmann	depends on X86_64 && PCI && AMD_NB
928a7f7f624SMasahiro Yamada	help
929ced3c42cSIngo Molnar	  Provides a driver for older AMD Athlon64/Opteron/Turion/Sempron
930ced3c42cSIngo Molnar	  GART based hardware IOMMUs.
931ced3c42cSIngo Molnar
932ced3c42cSIngo Molnar	  The GART supports full DMA access for devices with 32-bit access
933ced3c42cSIngo Molnar	  limitations, on systems with more than 3 GB. This is usually needed
934ced3c42cSIngo Molnar	  for USB, sound, many IDE/SATA chipsets and some other devices.
935ced3c42cSIngo Molnar
936ced3c42cSIngo Molnar	  Newer systems typically have a modern AMD IOMMU, supported via
937ced3c42cSIngo Molnar	  the CONFIG_AMD_IOMMU=y config option.
938ced3c42cSIngo Molnar
939ced3c42cSIngo Molnar	  In normal configurations this driver is only active when needed:
940ced3c42cSIngo Molnar	  there's more than 3 GB of memory and the system contains a
941ced3c42cSIngo Molnar	  32-bit limited device.
942ced3c42cSIngo Molnar
943ced3c42cSIngo Molnar	  If unsure, say Y.
944506f1d07SSam Ravnborg
945*8b766b0fSMichal Suchanekconfig BOOT_VESA_SUPPORT
946*8b766b0fSMichal Suchanek	bool
947*8b766b0fSMichal Suchanek	help
948*8b766b0fSMichal Suchanek	  If true, at least one selected framebuffer driver can take advantage
949*8b766b0fSMichal Suchanek	  of VESA video modes set at an early boot stage via the vga= parameter.
950*8b766b0fSMichal Suchanek
9511184dc2fSMike Travisconfig MAXSMP
952ddb0c5a6SSamuel Thibault	bool "Enable Maximum number of SMP Processors and NUMA Nodes"
9536ea30386SKees Cook	depends on X86_64 && SMP && DEBUG_KERNEL
95436f5101aSMike Travis	select CPUMASK_OFFSTACK
955a7f7f624SMasahiro Yamada	help
956ddb0c5a6SSamuel Thibault	  Enable maximum number of CPUS and NUMA Nodes for this architecture.
9571184dc2fSMike Travis	  If unsure, say N.
958506f1d07SSam Ravnborg
959aec6487eSIngo Molnar#
960aec6487eSIngo Molnar# The maximum number of CPUs supported:
961aec6487eSIngo Molnar#
962aec6487eSIngo Molnar# The main config value is NR_CPUS, which defaults to NR_CPUS_DEFAULT,
963aec6487eSIngo Molnar# and which can be configured interactively in the
964aec6487eSIngo Molnar# [NR_CPUS_RANGE_BEGIN ... NR_CPUS_RANGE_END] range.
965aec6487eSIngo Molnar#
966aec6487eSIngo Molnar# The ranges are different on 32-bit and 64-bit kernels, depending on
967aec6487eSIngo Molnar# hardware capabilities and scalability features of the kernel.
968aec6487eSIngo Molnar#
969aec6487eSIngo Molnar# ( If MAXSMP is enabled we just use the highest possible value and disable
970aec6487eSIngo Molnar#   interactive configuration. )
971aec6487eSIngo Molnar#
972a0d0bb4dSRandy Dunlap
973aec6487eSIngo Molnarconfig NR_CPUS_RANGE_BEGIN
974a0d0bb4dSRandy Dunlap	int
975aec6487eSIngo Molnar	default NR_CPUS_RANGE_END if MAXSMP
976a0d0bb4dSRandy Dunlap	default    1 if !SMP
977a0d0bb4dSRandy Dunlap	default    2
978a0d0bb4dSRandy Dunlap
979aec6487eSIngo Molnarconfig NR_CPUS_RANGE_END
980a0d0bb4dSRandy Dunlap	int
981a0d0bb4dSRandy Dunlap	depends on X86_32
982aec6487eSIngo Molnar	default   64 if  SMP &&  X86_BIGSMP
983aec6487eSIngo Molnar	default    8 if  SMP && !X86_BIGSMP
984a0d0bb4dSRandy Dunlap	default    1 if !SMP
985a0d0bb4dSRandy Dunlap
986aec6487eSIngo Molnarconfig NR_CPUS_RANGE_END
987a0d0bb4dSRandy Dunlap	int
988a0d0bb4dSRandy Dunlap	depends on X86_64
9891edae1aeSScott Wood	default 8192 if  SMP && CPUMASK_OFFSTACK
9901edae1aeSScott Wood	default  512 if  SMP && !CPUMASK_OFFSTACK
991a0d0bb4dSRandy Dunlap	default    1 if !SMP
992aec6487eSIngo Molnar
993aec6487eSIngo Molnarconfig NR_CPUS_DEFAULT
994aec6487eSIngo Molnar	int
995aec6487eSIngo Molnar	depends on X86_32
996aec6487eSIngo Molnar	default   32 if  X86_BIGSMP
997aec6487eSIngo Molnar	default    8 if  SMP
998aec6487eSIngo Molnar	default    1 if !SMP
999aec6487eSIngo Molnar
1000aec6487eSIngo Molnarconfig NR_CPUS_DEFAULT
1001aec6487eSIngo Molnar	int
1002aec6487eSIngo Molnar	depends on X86_64
1003a0d0bb4dSRandy Dunlap	default 8192 if  MAXSMP
1004a0d0bb4dSRandy Dunlap	default   64 if  SMP
1005aec6487eSIngo Molnar	default    1 if !SMP
1006a0d0bb4dSRandy Dunlap
1007506f1d07SSam Ravnborgconfig NR_CPUS
100836f5101aSMike Travis	int "Maximum number of CPUs" if SMP && !MAXSMP
1009aec6487eSIngo Molnar	range NR_CPUS_RANGE_BEGIN NR_CPUS_RANGE_END
1010aec6487eSIngo Molnar	default NR_CPUS_DEFAULT
1011a7f7f624SMasahiro Yamada	help
1012506f1d07SSam Ravnborg	  This allows you to specify the maximum number of CPUs which this
1013bb61ccc7SJosh Boyer	  kernel will support.  If CPUMASK_OFFSTACK is enabled, the maximum
1014cad14bb9SKirill A. Shutemov	  supported value is 8192, otherwise the maximum value is 512.  The
1015506f1d07SSam Ravnborg	  minimum value which makes sense is 2.
1016506f1d07SSam Ravnborg
1017aec6487eSIngo Molnar	  This is purely to save memory: each supported CPU adds about 8KB
1018aec6487eSIngo Molnar	  to the kernel image.
1019506f1d07SSam Ravnborg
102066558b73STim Chenconfig SCHED_CLUSTER
102166558b73STim Chen	bool "Cluster scheduler support"
102266558b73STim Chen	depends on SMP
102366558b73STim Chen	default y
102466558b73STim Chen	help
102566558b73STim Chen	  Cluster scheduler support improves the CPU scheduler's decision
102666558b73STim Chen	  making when dealing with machines that have clusters of CPUs.
102766558b73STim Chen	  Cluster usually means a couple of CPUs which are placed closely
102866558b73STim Chen	  by sharing mid-level caches, last-level cache tags or internal
102966558b73STim Chen	  busses.
103066558b73STim Chen
1031506f1d07SSam Ravnborgconfig SCHED_SMT
1032dbe73364SThomas Gleixner	def_bool y if SMP
1033506f1d07SSam Ravnborg
1034506f1d07SSam Ravnborgconfig SCHED_MC
10353c2362e6SHarvey Harrison	def_bool y
10363c2362e6SHarvey Harrison	prompt "Multi-core scheduler support"
1037c8e56d20SBorislav Petkov	depends on SMP
1038a7f7f624SMasahiro Yamada	help
1039506f1d07SSam Ravnborg	  Multi-core scheduler support improves the CPU scheduler's decision
1040506f1d07SSam Ravnborg	  making when dealing with multi-core CPU chips at a cost of slightly
1041506f1d07SSam Ravnborg	  increased overhead in some places. If unsure say N here.
1042506f1d07SSam Ravnborg
1043de966cf4STim Chenconfig SCHED_MC_PRIO
1044de966cf4STim Chen	bool "CPU core priorities scheduler support"
10450a21fc12SIngo Molnar	depends on SCHED_MC && CPU_SUP_INTEL
10460a21fc12SIngo Molnar	select X86_INTEL_PSTATE
10470a21fc12SIngo Molnar	select CPU_FREQ
1048de966cf4STim Chen	default y
1049a7f7f624SMasahiro Yamada	help
1050de966cf4STim Chen	  Intel Turbo Boost Max Technology 3.0 enabled CPUs have a
1051de966cf4STim Chen	  core ordering determined at manufacturing time, which allows
1052de966cf4STim Chen	  certain cores to reach higher turbo frequencies (when running
1053de966cf4STim Chen	  single threaded workloads) than others.
1054de966cf4STim Chen
1055de966cf4STim Chen	  Enabling this kernel feature teaches the scheduler about
1056de966cf4STim Chen	  the TBM3 (aka ITMT) priority order of the CPU cores and adjusts the
1057de966cf4STim Chen	  scheduler's CPU selection logic accordingly, so that higher
1058de966cf4STim Chen	  overall system performance can be achieved.
1059de966cf4STim Chen
1060de966cf4STim Chen	  This feature will have no effect on CPUs without this feature.
1061de966cf4STim Chen
1062de966cf4STim Chen	  If unsure say Y here.
10635e76b2abSTim Chen
106430b8b006SThomas Gleixnerconfig UP_LATE_INIT
106530b8b006SThomas Gleixner	def_bool y
1066ba360f88SThomas Gleixner	depends on !SMP && X86_LOCAL_APIC
106730b8b006SThomas Gleixner
1068506f1d07SSam Ravnborgconfig X86_UP_APIC
106950849eefSJan Beulich	bool "Local APIC support on uniprocessors" if !PCI_MSI
107050849eefSJan Beulich	default PCI_MSI
107138a1dfdaSBryan O'Donoghue	depends on X86_32 && !SMP && !X86_32_NON_STANDARD
1072a7f7f624SMasahiro Yamada	help
1073506f1d07SSam Ravnborg	  A local APIC (Advanced Programmable Interrupt Controller) is an
1074506f1d07SSam Ravnborg	  integrated interrupt controller in the CPU. If you have a single-CPU
1075506f1d07SSam Ravnborg	  system which has a processor with a local APIC, you can say Y here to
1076506f1d07SSam Ravnborg	  enable and use it. If you say Y here even though your machine doesn't
1077506f1d07SSam Ravnborg	  have a local APIC, then the kernel will still run with no slowdown at
1078506f1d07SSam Ravnborg	  all. The local APIC supports CPU-generated self-interrupts (timer,
1079506f1d07SSam Ravnborg	  performance counters), and the NMI watchdog which detects hard
1080506f1d07SSam Ravnborg	  lockups.
1081506f1d07SSam Ravnborg
1082506f1d07SSam Ravnborgconfig X86_UP_IOAPIC
1083506f1d07SSam Ravnborg	bool "IO-APIC support on uniprocessors"
1084506f1d07SSam Ravnborg	depends on X86_UP_APIC
1085a7f7f624SMasahiro Yamada	help
1086506f1d07SSam Ravnborg	  An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an
1087506f1d07SSam Ravnborg	  SMP-capable replacement for PC-style interrupt controllers. Most
1088506f1d07SSam Ravnborg	  SMP systems and many recent uniprocessor systems have one.
1089506f1d07SSam Ravnborg
1090506f1d07SSam Ravnborg	  If you have a single-CPU system with an IO-APIC, you can say Y here
1091506f1d07SSam Ravnborg	  to use it. If you say Y here even though your machine doesn't have
1092506f1d07SSam Ravnborg	  an IO-APIC, then the kernel will still run with no slowdown at all.
1093506f1d07SSam Ravnborg
1094506f1d07SSam Ravnborgconfig X86_LOCAL_APIC
10953c2362e6SHarvey Harrison	def_bool y
10960dbc6078SThomas Petazzoni	depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC || PCI_MSI
1097b5dc8e6cSJiang Liu	select IRQ_DOMAIN_HIERARCHY
109852f518a3SJiang Liu	select PCI_MSI_IRQ_DOMAIN if PCI_MSI
1099506f1d07SSam Ravnborg
1100506f1d07SSam Ravnborgconfig X86_IO_APIC
1101b1da1e71SJan Beulich	def_bool y
1102b1da1e71SJan Beulich	depends on X86_LOCAL_APIC || X86_UP_IOAPIC
1103506f1d07SSam Ravnborg
110441b9eb26SStefan Assmannconfig X86_REROUTE_FOR_BROKEN_BOOT_IRQS
110541b9eb26SStefan Assmann	bool "Reroute for broken boot IRQs"
110641b9eb26SStefan Assmann	depends on X86_IO_APIC
1107a7f7f624SMasahiro Yamada	help
110841b9eb26SStefan Assmann	  This option enables a workaround that fixes a source of
110941b9eb26SStefan Assmann	  spurious interrupts. This is recommended when threaded
111041b9eb26SStefan Assmann	  interrupt handling is used on systems where the generation of
111141b9eb26SStefan Assmann	  superfluous "boot interrupts" cannot be disabled.
111241b9eb26SStefan Assmann
111341b9eb26SStefan Assmann	  Some chipsets generate a legacy INTx "boot IRQ" when the IRQ
111441b9eb26SStefan Assmann	  entry in the chipset's IO-APIC is masked (as, e.g. the RT
111541b9eb26SStefan Assmann	  kernel does during interrupt handling). On chipsets where this
111641b9eb26SStefan Assmann	  boot IRQ generation cannot be disabled, this workaround keeps
111741b9eb26SStefan Assmann	  the original IRQ line masked so that only the equivalent "boot
111841b9eb26SStefan Assmann	  IRQ" is delivered to the CPUs. The workaround also tells the
111941b9eb26SStefan Assmann	  kernel to set up the IRQ handler on the boot IRQ line. In this
112041b9eb26SStefan Assmann	  way only one interrupt is delivered to the kernel. Otherwise
112141b9eb26SStefan Assmann	  the spurious second interrupt may cause the kernel to bring
112241b9eb26SStefan Assmann	  down (vital) interrupt lines.
112341b9eb26SStefan Assmann
112441b9eb26SStefan Assmann	  Only affects "broken" chipsets. Interrupt sharing may be
112541b9eb26SStefan Assmann	  increased on these systems.
112641b9eb26SStefan Assmann
1127506f1d07SSam Ravnborgconfig X86_MCE
1128bab9bc65SAndi Kleen	bool "Machine Check / overheating reporting"
1129648ed940SChen, Gong	select GENERIC_ALLOCATOR
1130e57dbaf7SBorislav Petkov	default y
1131a7f7f624SMasahiro Yamada	help
1132bab9bc65SAndi Kleen	  Machine Check support allows the processor to notify the
1133bab9bc65SAndi Kleen	  kernel if it detects a problem (e.g. overheating, data corruption).
1134506f1d07SSam Ravnborg	  The action the kernel takes depends on the severity of the problem,
1135bab9bc65SAndi Kleen	  ranging from warning messages to halting the machine.
11364efc0670SAndi Kleen
11375de97c9fSTony Luckconfig X86_MCELOG_LEGACY
11385de97c9fSTony Luck	bool "Support for deprecated /dev/mcelog character device"
11395de97c9fSTony Luck	depends on X86_MCE
1140a7f7f624SMasahiro Yamada	help
11415de97c9fSTony Luck	  Enable support for /dev/mcelog which is needed by the old mcelog
11425de97c9fSTony Luck	  userspace logging daemon. Consider switching to the new generation
11435de97c9fSTony Luck	  rasdaemon solution.
11445de97c9fSTony Luck
1145506f1d07SSam Ravnborgconfig X86_MCE_INTEL
11463c2362e6SHarvey Harrison	def_bool y
11473c2362e6SHarvey Harrison	prompt "Intel MCE features"
1148c1ebf835SAndi Kleen	depends on X86_MCE && X86_LOCAL_APIC
1149a7f7f624SMasahiro Yamada	help
1150506f1d07SSam Ravnborg	   Additional support for intel specific MCE features such as
1151506f1d07SSam Ravnborg	   the thermal monitor.
1152506f1d07SSam Ravnborg
1153506f1d07SSam Ravnborgconfig X86_MCE_AMD
11543c2362e6SHarvey Harrison	def_bool y
11553c2362e6SHarvey Harrison	prompt "AMD MCE features"
1156f5382de9SYazen Ghannam	depends on X86_MCE && X86_LOCAL_APIC && AMD_NB
1157a7f7f624SMasahiro Yamada	help
1158506f1d07SSam Ravnborg	   Additional support for AMD specific MCE features such as
1159506f1d07SSam Ravnborg	   the DRAM Error Threshold.
1160506f1d07SSam Ravnborg
11614efc0670SAndi Kleenconfig X86_ANCIENT_MCE
11626fc108a0SJan Beulich	bool "Support for old Pentium 5 / WinChip machine checks"
1163c31d9633SAndi Kleen	depends on X86_32 && X86_MCE
1164a7f7f624SMasahiro Yamada	help
11654efc0670SAndi Kleen	  Include support for machine check handling on old Pentium 5 or WinChip
11665065a706SMasanari Iida	  systems. These typically need to be enabled explicitly on the command
11674efc0670SAndi Kleen	  line.
11684efc0670SAndi Kleen
1169b2762686SAndi Kleenconfig X86_MCE_THRESHOLD
1170b2762686SAndi Kleen	depends on X86_MCE_AMD || X86_MCE_INTEL
11716fc108a0SJan Beulich	def_bool y
1172b2762686SAndi Kleen
1173ea149b36SAndi Kleenconfig X86_MCE_INJECT
1174bc8e80d5SBorislav Petkov	depends on X86_MCE && X86_LOCAL_APIC && DEBUG_FS
1175ea149b36SAndi Kleen	tristate "Machine check injector support"
1176a7f7f624SMasahiro Yamada	help
1177ea149b36SAndi Kleen	  Provide support for injecting machine checks for testing purposes.
1178ea149b36SAndi Kleen	  If you don't know what a machine check is and you don't do kernel
1179ea149b36SAndi Kleen	  QA it is safe to say n.
1180ea149b36SAndi Kleen
118107dc900eSPeter Zijlstrasource "arch/x86/events/Kconfig"
1182e633c65aSKan Liang
11835aef51c3SAndy Lutomirskiconfig X86_LEGACY_VM86
11841e642812SIngo Molnar	bool "Legacy VM86 support"
1185506f1d07SSam Ravnborg	depends on X86_32
1186a7f7f624SMasahiro Yamada	help
11875aef51c3SAndy Lutomirski	  This option allows user programs to put the CPU into V8086
11885aef51c3SAndy Lutomirski	  mode, which is an 80286-era approximation of 16-bit real mode.
11895aef51c3SAndy Lutomirski
11905aef51c3SAndy Lutomirski	  Some very old versions of X and/or vbetool require this option
11915aef51c3SAndy Lutomirski	  for user mode setting.  Similarly, DOSEMU will use it if
11925aef51c3SAndy Lutomirski	  available to accelerate real mode DOS programs.  However, any
11935aef51c3SAndy Lutomirski	  recent version of DOSEMU, X, or vbetool should be fully
11945aef51c3SAndy Lutomirski	  functional even without kernel VM86 support, as they will all
11951e642812SIngo Molnar	  fall back to software emulation. Nevertheless, if you are using
11961e642812SIngo Molnar	  a 16-bit DOS program where 16-bit performance matters, vm86
11971e642812SIngo Molnar	  mode might be faster than emulation and you might want to
11981e642812SIngo Molnar	  enable this option.
11995aef51c3SAndy Lutomirski
12001e642812SIngo Molnar	  Note that any app that works on a 64-bit kernel is unlikely to
12011e642812SIngo Molnar	  need this option, as 64-bit kernels don't, and can't, support
12021e642812SIngo Molnar	  V8086 mode. This option is also unrelated to 16-bit protected
12031e642812SIngo Molnar	  mode and is not needed to run most 16-bit programs under Wine.
12045aef51c3SAndy Lutomirski
12051e642812SIngo Molnar	  Enabling this option increases the complexity of the kernel
12061e642812SIngo Molnar	  and slows down exception handling a tiny bit.
12075aef51c3SAndy Lutomirski
12081e642812SIngo Molnar	  If unsure, say N here.
12095aef51c3SAndy Lutomirski
12105aef51c3SAndy Lutomirskiconfig VM86
12115aef51c3SAndy Lutomirski	bool
12125aef51c3SAndy Lutomirski	default X86_LEGACY_VM86
121334273f41SH. Peter Anvin
121434273f41SH. Peter Anvinconfig X86_16BIT
121534273f41SH. Peter Anvin	bool "Enable support for 16-bit segments" if EXPERT
121634273f41SH. Peter Anvin	default y
1217a5b9e5a2SAndy Lutomirski	depends on MODIFY_LDT_SYSCALL
1218a7f7f624SMasahiro Yamada	help
121934273f41SH. Peter Anvin	  This option is required by programs like Wine to run 16-bit
122034273f41SH. Peter Anvin	  protected mode legacy code on x86 processors.  Disabling
122134273f41SH. Peter Anvin	  this option saves about 300 bytes on i386, or around 6K text
122234273f41SH. Peter Anvin	  plus 16K runtime memory on x86-64,
122334273f41SH. Peter Anvin
122434273f41SH. Peter Anvinconfig X86_ESPFIX32
122534273f41SH. Peter Anvin	def_bool y
122634273f41SH. Peter Anvin	depends on X86_16BIT && X86_32
1227506f1d07SSam Ravnborg
1228197725deSH. Peter Anvinconfig X86_ESPFIX64
1229197725deSH. Peter Anvin	def_bool y
123034273f41SH. Peter Anvin	depends on X86_16BIT && X86_64
1231506f1d07SSam Ravnborg
12321ad83c85SAndy Lutomirskiconfig X86_VSYSCALL_EMULATION
12331ad83c85SAndy Lutomirski	bool "Enable vsyscall emulation" if EXPERT
12341ad83c85SAndy Lutomirski	default y
12351ad83c85SAndy Lutomirski	depends on X86_64
1236a7f7f624SMasahiro Yamada	help
12371ad83c85SAndy Lutomirski	 This enables emulation of the legacy vsyscall page.  Disabling
12381ad83c85SAndy Lutomirski	 it is roughly equivalent to booting with vsyscall=none, except
12391ad83c85SAndy Lutomirski	 that it will also disable the helpful warning if a program
12401ad83c85SAndy Lutomirski	 tries to use a vsyscall.  With this option set to N, offending
12411ad83c85SAndy Lutomirski	 programs will just segfault, citing addresses of the form
12421ad83c85SAndy Lutomirski	 0xffffffffff600?00.
12431ad83c85SAndy Lutomirski
12441ad83c85SAndy Lutomirski	 This option is required by many programs built before 2013, and
12451ad83c85SAndy Lutomirski	 care should be used even with newer programs if set to N.
12461ad83c85SAndy Lutomirski
12471ad83c85SAndy Lutomirski	 Disabling this option saves about 7K of kernel size and
12481ad83c85SAndy Lutomirski	 possibly 4K of additional runtime pagetable memory.
12491ad83c85SAndy Lutomirski
1250111e7b15SThomas Gleixnerconfig X86_IOPL_IOPERM
1251111e7b15SThomas Gleixner	bool "IOPERM and IOPL Emulation"
1252a24ca997SThomas Gleixner	default y
1253a7f7f624SMasahiro Yamada	help
1254111e7b15SThomas Gleixner	  This enables the ioperm() and iopl() syscalls which are necessary
1255111e7b15SThomas Gleixner	  for legacy applications.
1256111e7b15SThomas Gleixner
1257c8137aceSThomas Gleixner	  Legacy IOPL support is an overbroad mechanism which allows user
1258c8137aceSThomas Gleixner	  space aside of accessing all 65536 I/O ports also to disable
1259c8137aceSThomas Gleixner	  interrupts. To gain this access the caller needs CAP_SYS_RAWIO
1260c8137aceSThomas Gleixner	  capabilities and permission from potentially active security
1261c8137aceSThomas Gleixner	  modules.
1262c8137aceSThomas Gleixner
1263c8137aceSThomas Gleixner	  The emulation restricts the functionality of the syscall to
1264c8137aceSThomas Gleixner	  only allowing the full range I/O port access, but prevents the
1265a24ca997SThomas Gleixner	  ability to disable interrupts from user space which would be
1266a24ca997SThomas Gleixner	  granted if the hardware IOPL mechanism would be used.
1267c8137aceSThomas Gleixner
1268506f1d07SSam Ravnborgconfig TOSHIBA
1269506f1d07SSam Ravnborg	tristate "Toshiba Laptop support"
1270506f1d07SSam Ravnborg	depends on X86_32
1271a7f7f624SMasahiro Yamada	help
1272506f1d07SSam Ravnborg	  This adds a driver to safely access the System Management Mode of
1273506f1d07SSam Ravnborg	  the CPU on Toshiba portables with a genuine Toshiba BIOS. It does
1274506f1d07SSam Ravnborg	  not work on models with a Phoenix BIOS. The System Management Mode
1275506f1d07SSam Ravnborg	  is used to set the BIOS and power saving options on Toshiba portables.
1276506f1d07SSam Ravnborg
1277506f1d07SSam Ravnborg	  For information on utilities to make use of this driver see the
1278506f1d07SSam Ravnborg	  Toshiba Linux utilities web site at:
1279506f1d07SSam Ravnborg	  <http://www.buzzard.org.uk/toshiba/>.
1280506f1d07SSam Ravnborg
1281506f1d07SSam Ravnborg	  Say Y if you intend to run this kernel on a Toshiba portable.
1282506f1d07SSam Ravnborg	  Say N otherwise.
1283506f1d07SSam Ravnborg
1284506f1d07SSam Ravnborgconfig I8K
1285039ae585SPali Rohár	tristate "Dell i8k legacy laptop support"
1286ef775a0eSRandy Dunlap	depends on HWMON
1287ef775a0eSRandy Dunlap	depends on PROC_FS
1288039ae585SPali Rohár	select SENSORS_DELL_SMM
1289a7f7f624SMasahiro Yamada	help
1290039ae585SPali Rohár	  This option enables legacy /proc/i8k userspace interface in hwmon
1291039ae585SPali Rohár	  dell-smm-hwmon driver. Character file /proc/i8k reports bios version,
1292039ae585SPali Rohár	  temperature and allows controlling fan speeds of Dell laptops via
1293039ae585SPali Rohár	  System Management Mode. For old Dell laptops (like Dell Inspiron 8000)
1294039ae585SPali Rohár	  it reports also power and hotkey status. For fan speed control is
1295039ae585SPali Rohár	  needed userspace package i8kutils.
1296506f1d07SSam Ravnborg
1297039ae585SPali Rohár	  Say Y if you intend to run this kernel on old Dell laptops or want to
1298039ae585SPali Rohár	  use userspace package i8kutils.
1299506f1d07SSam Ravnborg	  Say N otherwise.
1300506f1d07SSam Ravnborg
1301506f1d07SSam Ravnborgconfig X86_REBOOTFIXUPS
13029ba16087SJan Beulich	bool "Enable X86 board specific fixups for reboot"
13039ba16087SJan Beulich	depends on X86_32
1304a7f7f624SMasahiro Yamada	help
1305506f1d07SSam Ravnborg	  This enables chipset and/or board specific fixups to be done
1306506f1d07SSam Ravnborg	  in order to get reboot to work correctly. This is only needed on
1307506f1d07SSam Ravnborg	  some combinations of hardware and BIOS. The symptom, for which
1308506f1d07SSam Ravnborg	  this config is intended, is when reboot ends with a stalled/hung
1309506f1d07SSam Ravnborg	  system.
1310506f1d07SSam Ravnborg
1311506f1d07SSam Ravnborg	  Currently, the only fixup is for the Geode machines using
13125e3a77e9SFlorian Fainelli	  CS5530A and CS5536 chipsets and the RDC R-321x SoC.
1313506f1d07SSam Ravnborg
1314506f1d07SSam Ravnborg	  Say Y if you want to enable the fixup. Currently, it's safe to
1315506f1d07SSam Ravnborg	  enable this option even if you don't need it.
1316506f1d07SSam Ravnborg	  Say N otherwise.
1317506f1d07SSam Ravnborg
1318506f1d07SSam Ravnborgconfig MICROCODE
13199a2bc335SBorislav Petkov	bool "CPU microcode loading support"
13209a2bc335SBorislav Petkov	default y
132180030e3dSBorislav Petkov	depends on CPU_SUP_AMD || CPU_SUP_INTEL
1322a7f7f624SMasahiro Yamada	help
1323506f1d07SSam Ravnborg	  If you say Y here, you will be able to update the microcode on
13245f9c01aaSBorislav Petkov	  Intel and AMD processors. The Intel support is for the IA32 family,
13255f9c01aaSBorislav Petkov	  e.g. Pentium Pro, Pentium II, Pentium III, Pentium 4, Xeon etc. The
13265f9c01aaSBorislav Petkov	  AMD support is for families 0x10 and later. You will obviously need
13275f9c01aaSBorislav Petkov	  the actual microcode binary data itself which is not shipped with
13285f9c01aaSBorislav Petkov	  the Linux kernel.
1329506f1d07SSam Ravnborg
13305f9c01aaSBorislav Petkov	  The preferred method to load microcode from a detached initrd is described
1331cb1aaebeSMauro Carvalho Chehab	  in Documentation/x86/microcode.rst. For that you need to enable
13325f9c01aaSBorislav Petkov	  CONFIG_BLK_DEV_INITRD in order for the loader to be able to scan the
13335f9c01aaSBorislav Petkov	  initrd for microcode blobs.
1334506f1d07SSam Ravnborg
1335c508c46eSBenjamin Gilbert	  In addition, you can build the microcode into the kernel. For that you
1336c508c46eSBenjamin Gilbert	  need to add the vendor-supplied microcode to the CONFIG_EXTRA_FIRMWARE
1337c508c46eSBenjamin Gilbert	  config option.
1338506f1d07SSam Ravnborg
13398d86f390SPeter Orubaconfig MICROCODE_INTEL
1340e43f6e67SBorislav Petkov	bool "Intel microcode loading support"
13418d86f390SPeter Oruba	depends on MICROCODE
13428d86f390SPeter Oruba	default MICROCODE
1343a7f7f624SMasahiro Yamada	help
13448d86f390SPeter Oruba	  This options enables microcode patch loading support for Intel
13458d86f390SPeter Oruba	  processors.
13468d86f390SPeter Oruba
1347b8989db9SAlan	  For the current Intel microcode data package go to
1348b8989db9SAlan	  <https://downloadcenter.intel.com> and search for
1349b8989db9SAlan	  'Linux Processor Microcode Data File'.
13508d86f390SPeter Oruba
135180cc9f10SPeter Orubaconfig MICROCODE_AMD
1352e43f6e67SBorislav Petkov	bool "AMD microcode loading support"
135380cc9f10SPeter Oruba	depends on MICROCODE
1354a7f7f624SMasahiro Yamada	help
135580cc9f10SPeter Oruba	  If you select this option, microcode patch loading support for AMD
135680cc9f10SPeter Oruba	  processors will be enabled.
135780cc9f10SPeter Oruba
1358506f1d07SSam Ravnborgconfig MICROCODE_OLD_INTERFACE
1359c02f48e0SBorislav Petkov	bool "Ancient loading interface (DEPRECATED)"
1360c02f48e0SBorislav Petkov	default n
1361506f1d07SSam Ravnborg	depends on MICROCODE
1362a7f7f624SMasahiro Yamada	help
1363c02f48e0SBorislav Petkov	  DO NOT USE THIS! This is the ancient /dev/cpu/microcode interface
1364c02f48e0SBorislav Petkov	  which was used by userspace tools like iucode_tool and microcode.ctl.
1365c02f48e0SBorislav Petkov	  It is inadequate because it runs too late to be able to properly
1366c02f48e0SBorislav Petkov	  load microcode on a machine and it needs special tools. Instead, you
1367c02f48e0SBorislav Petkov	  should've switched to the early loading method with the initrd or
1368cb1aaebeSMauro Carvalho Chehab	  builtin microcode by now: Documentation/x86/microcode.rst
1369506f1d07SSam Ravnborg
1370506f1d07SSam Ravnborgconfig X86_MSR
1371506f1d07SSam Ravnborg	tristate "/dev/cpu/*/msr - Model-specific register support"
1372a7f7f624SMasahiro Yamada	help
1373506f1d07SSam Ravnborg	  This device gives privileged processes access to the x86
1374506f1d07SSam Ravnborg	  Model-Specific Registers (MSRs).  It is a character device with
1375506f1d07SSam Ravnborg	  major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr.
1376506f1d07SSam Ravnborg	  MSR accesses are directed to a specific CPU on multi-processor
1377506f1d07SSam Ravnborg	  systems.
1378506f1d07SSam Ravnborg
1379506f1d07SSam Ravnborgconfig X86_CPUID
1380506f1d07SSam Ravnborg	tristate "/dev/cpu/*/cpuid - CPU information support"
1381a7f7f624SMasahiro Yamada	help
1382506f1d07SSam Ravnborg	  This device gives processes access to the x86 CPUID instruction to
1383506f1d07SSam Ravnborg	  be executed on a specific processor.  It is a character device
1384506f1d07SSam Ravnborg	  with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to
1385506f1d07SSam Ravnborg	  /dev/cpu/31/cpuid.
1386506f1d07SSam Ravnborg
1387506f1d07SSam Ravnborgchoice
1388506f1d07SSam Ravnborg	prompt "High Memory Support"
13896fc108a0SJan Beulich	default HIGHMEM4G
1390506f1d07SSam Ravnborg	depends on X86_32
1391506f1d07SSam Ravnborg
1392506f1d07SSam Ravnborgconfig NOHIGHMEM
1393506f1d07SSam Ravnborg	bool "off"
1394a7f7f624SMasahiro Yamada	help
1395506f1d07SSam Ravnborg	  Linux can use up to 64 Gigabytes of physical memory on x86 systems.
1396506f1d07SSam Ravnborg	  However, the address space of 32-bit x86 processors is only 4
1397506f1d07SSam Ravnborg	  Gigabytes large. That means that, if you have a large amount of
1398506f1d07SSam Ravnborg	  physical memory, not all of it can be "permanently mapped" by the
1399506f1d07SSam Ravnborg	  kernel. The physical memory that's not permanently mapped is called
1400506f1d07SSam Ravnborg	  "high memory".
1401506f1d07SSam Ravnborg
1402506f1d07SSam Ravnborg	  If you are compiling a kernel which will never run on a machine with
1403506f1d07SSam Ravnborg	  more than 1 Gigabyte total physical RAM, answer "off" here (default
1404506f1d07SSam Ravnborg	  choice and suitable for most users). This will result in a "3GB/1GB"
1405506f1d07SSam Ravnborg	  split: 3GB are mapped so that each process sees a 3GB virtual memory
1406506f1d07SSam Ravnborg	  space and the remaining part of the 4GB virtual memory space is used
1407506f1d07SSam Ravnborg	  by the kernel to permanently map as much physical memory as
1408506f1d07SSam Ravnborg	  possible.
1409506f1d07SSam Ravnborg
1410506f1d07SSam Ravnborg	  If the machine has between 1 and 4 Gigabytes physical RAM, then
1411506f1d07SSam Ravnborg	  answer "4GB" here.
1412506f1d07SSam Ravnborg
1413506f1d07SSam Ravnborg	  If more than 4 Gigabytes is used then answer "64GB" here. This
1414506f1d07SSam Ravnborg	  selection turns Intel PAE (Physical Address Extension) mode on.
1415506f1d07SSam Ravnborg	  PAE implements 3-level paging on IA32 processors. PAE is fully
1416506f1d07SSam Ravnborg	  supported by Linux, PAE mode is implemented on all recent Intel
1417506f1d07SSam Ravnborg	  processors (Pentium Pro and better). NOTE: If you say "64GB" here,
1418506f1d07SSam Ravnborg	  then the kernel will not boot on CPUs that don't support PAE!
1419506f1d07SSam Ravnborg
1420506f1d07SSam Ravnborg	  The actual amount of total physical memory will either be
1421506f1d07SSam Ravnborg	  auto detected or can be forced by using a kernel command line option
1422506f1d07SSam Ravnborg	  such as "mem=256M". (Try "man bootparam" or see the documentation of
1423506f1d07SSam Ravnborg	  your boot loader (lilo or loadlin) about how to pass options to the
1424506f1d07SSam Ravnborg	  kernel at boot time.)
1425506f1d07SSam Ravnborg
1426506f1d07SSam Ravnborg	  If unsure, say "off".
1427506f1d07SSam Ravnborg
1428506f1d07SSam Ravnborgconfig HIGHMEM4G
1429506f1d07SSam Ravnborg	bool "4GB"
1430a7f7f624SMasahiro Yamada	help
1431506f1d07SSam Ravnborg	  Select this if you have a 32-bit processor and between 1 and 4
1432506f1d07SSam Ravnborg	  gigabytes of physical RAM.
1433506f1d07SSam Ravnborg
1434506f1d07SSam Ravnborgconfig HIGHMEM64G
1435506f1d07SSam Ravnborg	bool "64GB"
1436225bac2dSLukas Bulwahn	depends on !M486SX && !M486 && !M586 && !M586TSC && !M586MMX && !MGEODE_LX && !MGEODEGX1 && !MCYRIXIII && !MELAN && !MWINCHIPC6 && !MWINCHIP3D && !MK6
1437506f1d07SSam Ravnborg	select X86_PAE
1438a7f7f624SMasahiro Yamada	help
1439506f1d07SSam Ravnborg	  Select this if you have a 32-bit processor and more than 4
1440506f1d07SSam Ravnborg	  gigabytes of physical RAM.
1441506f1d07SSam Ravnborg
1442506f1d07SSam Ravnborgendchoice
1443506f1d07SSam Ravnborg
1444506f1d07SSam Ravnborgchoice
14456a108a14SDavid Rientjes	prompt "Memory split" if EXPERT
1446506f1d07SSam Ravnborg	default VMSPLIT_3G
1447506f1d07SSam Ravnborg	depends on X86_32
1448a7f7f624SMasahiro Yamada	help
1449506f1d07SSam Ravnborg	  Select the desired split between kernel and user memory.
1450506f1d07SSam Ravnborg
1451506f1d07SSam Ravnborg	  If the address range available to the kernel is less than the
1452506f1d07SSam Ravnborg	  physical memory installed, the remaining memory will be available
1453506f1d07SSam Ravnborg	  as "high memory". Accessing high memory is a little more costly
1454506f1d07SSam Ravnborg	  than low memory, as it needs to be mapped into the kernel first.
1455506f1d07SSam Ravnborg	  Note that increasing the kernel address space limits the range
1456506f1d07SSam Ravnborg	  available to user programs, making the address space there
1457506f1d07SSam Ravnborg	  tighter.  Selecting anything other than the default 3G/1G split
1458506f1d07SSam Ravnborg	  will also likely make your kernel incompatible with binary-only
1459506f1d07SSam Ravnborg	  kernel modules.
1460506f1d07SSam Ravnborg
1461506f1d07SSam Ravnborg	  If you are not absolutely sure what you are doing, leave this
1462506f1d07SSam Ravnborg	  option alone!
1463506f1d07SSam Ravnborg
1464506f1d07SSam Ravnborg	config VMSPLIT_3G
1465506f1d07SSam Ravnborg		bool "3G/1G user/kernel split"
1466506f1d07SSam Ravnborg	config VMSPLIT_3G_OPT
1467506f1d07SSam Ravnborg		depends on !X86_PAE
1468506f1d07SSam Ravnborg		bool "3G/1G user/kernel split (for full 1G low memory)"
1469506f1d07SSam Ravnborg	config VMSPLIT_2G
1470506f1d07SSam Ravnborg		bool "2G/2G user/kernel split"
1471506f1d07SSam Ravnborg	config VMSPLIT_2G_OPT
1472506f1d07SSam Ravnborg		depends on !X86_PAE
1473506f1d07SSam Ravnborg		bool "2G/2G user/kernel split (for full 2G low memory)"
1474506f1d07SSam Ravnborg	config VMSPLIT_1G
1475506f1d07SSam Ravnborg		bool "1G/3G user/kernel split"
1476506f1d07SSam Ravnborgendchoice
1477506f1d07SSam Ravnborg
1478506f1d07SSam Ravnborgconfig PAGE_OFFSET
1479506f1d07SSam Ravnborg	hex
1480506f1d07SSam Ravnborg	default 0xB0000000 if VMSPLIT_3G_OPT
1481506f1d07SSam Ravnborg	default 0x80000000 if VMSPLIT_2G
1482506f1d07SSam Ravnborg	default 0x78000000 if VMSPLIT_2G_OPT
1483506f1d07SSam Ravnborg	default 0x40000000 if VMSPLIT_1G
1484506f1d07SSam Ravnborg	default 0xC0000000
1485506f1d07SSam Ravnborg	depends on X86_32
1486506f1d07SSam Ravnborg
1487506f1d07SSam Ravnborgconfig HIGHMEM
14883c2362e6SHarvey Harrison	def_bool y
1489506f1d07SSam Ravnborg	depends on X86_32 && (HIGHMEM64G || HIGHMEM4G)
1490506f1d07SSam Ravnborg
1491506f1d07SSam Ravnborgconfig X86_PAE
14929ba16087SJan Beulich	bool "PAE (Physical Address Extension) Support"
1493506f1d07SSam Ravnborg	depends on X86_32 && !HIGHMEM4G
1494d4a451d5SChristoph Hellwig	select PHYS_ADDR_T_64BIT
14959d99c712SChristian Melki	select SWIOTLB
1496a7f7f624SMasahiro Yamada	help
1497506f1d07SSam Ravnborg	  PAE is required for NX support, and furthermore enables
1498506f1d07SSam Ravnborg	  larger swapspace support for non-overcommit purposes. It
1499506f1d07SSam Ravnborg	  has the cost of more pagetable lookup overhead, and also
1500506f1d07SSam Ravnborg	  consumes more pagetable space per process.
1501506f1d07SSam Ravnborg
150277ef56e4SKirill A. Shutemovconfig X86_5LEVEL
150377ef56e4SKirill A. Shutemov	bool "Enable 5-level page tables support"
150418ec1eafSKirill A. Shutemov	default y
1505eedb92abSKirill A. Shutemov	select DYNAMIC_MEMORY_LAYOUT
1506162434e7SKirill A. Shutemov	select SPARSEMEM_VMEMMAP
150777ef56e4SKirill A. Shutemov	depends on X86_64
1508a7f7f624SMasahiro Yamada	help
150977ef56e4SKirill A. Shutemov	  5-level paging enables access to larger address space:
151077ef56e4SKirill A. Shutemov	  upto 128 PiB of virtual address space and 4 PiB of
151177ef56e4SKirill A. Shutemov	  physical address space.
151277ef56e4SKirill A. Shutemov
151377ef56e4SKirill A. Shutemov	  It will be supported by future Intel CPUs.
151477ef56e4SKirill A. Shutemov
15156657fca0SKirill A. Shutemov	  A kernel with the option enabled can be booted on machines that
15166657fca0SKirill A. Shutemov	  support 4- or 5-level paging.
151777ef56e4SKirill A. Shutemov
1518cb1aaebeSMauro Carvalho Chehab	  See Documentation/x86/x86_64/5level-paging.rst for more
151977ef56e4SKirill A. Shutemov	  information.
152077ef56e4SKirill A. Shutemov
152177ef56e4SKirill A. Shutemov	  Say N if unsure.
152277ef56e4SKirill A. Shutemov
152310971ab2SIngo Molnarconfig X86_DIRECT_GBPAGES
1524e5008abeSLuis R. Rodriguez	def_bool y
15252e1da13fSVlastimil Babka	depends on X86_64
1526a7f7f624SMasahiro Yamada	help
152710971ab2SIngo Molnar	  Certain kernel features effectively disable kernel
152810971ab2SIngo Molnar	  linear 1 GB mappings (even if the CPU otherwise
152910971ab2SIngo Molnar	  supports them), so don't confuse the user by printing
153010971ab2SIngo Molnar	  that we have them enabled.
15319e899816SNick Piggin
15325c280cf6SThomas Gleixnerconfig X86_CPA_STATISTICS
15335c280cf6SThomas Gleixner	bool "Enable statistic for Change Page Attribute"
15345c280cf6SThomas Gleixner	depends on DEBUG_FS
1535a7f7f624SMasahiro Yamada	help
1536b75baaf3SIngo Molnar	  Expose statistics about the Change Page Attribute mechanism, which
1537a943245aSColin Ian King	  helps to determine the effectiveness of preserving large and huge
15385c280cf6SThomas Gleixner	  page mappings when mapping protections are changed.
15395c280cf6SThomas Gleixner
154020f07a04SKirill A. Shutemovconfig X86_MEM_ENCRYPT
154120f07a04SKirill A. Shutemov	select ARCH_HAS_FORCE_DMA_UNENCRYPTED
154220f07a04SKirill A. Shutemov	select DYNAMIC_PHYSICAL_MASK
154320f07a04SKirill A. Shutemov	select ARCH_HAS_RESTRICTED_VIRTIO_MEMORY_ACCESS
154420f07a04SKirill A. Shutemov	def_bool n
154520f07a04SKirill A. Shutemov
15467744ccdbSTom Lendackyconfig AMD_MEM_ENCRYPT
15477744ccdbSTom Lendacky	bool "AMD Secure Memory Encryption (SME) support"
15487744ccdbSTom Lendacky	depends on X86_64 && CPU_SUP_AMD
154982fef0adSDavid Rientjes	select DMA_COHERENT_POOL
1550ce9084baSArd Biesheuvel	select ARCH_USE_MEMREMAP_PROT
1551597cfe48SJoerg Roedel	select INSTRUCTION_DECODER
1552aa5a4611STom Lendacky	select ARCH_HAS_CC_PLATFORM
155320f07a04SKirill A. Shutemov	select X86_MEM_ENCRYPT
1554a7f7f624SMasahiro Yamada	help
15557744ccdbSTom Lendacky	  Say yes to enable support for the encryption of system memory.
15567744ccdbSTom Lendacky	  This requires an AMD processor that supports Secure Memory
15577744ccdbSTom Lendacky	  Encryption (SME).
15587744ccdbSTom Lendacky
15597744ccdbSTom Lendackyconfig AMD_MEM_ENCRYPT_ACTIVE_BY_DEFAULT
15607744ccdbSTom Lendacky	bool "Activate AMD Secure Memory Encryption (SME) by default"
15617744ccdbSTom Lendacky	depends on AMD_MEM_ENCRYPT
1562a7f7f624SMasahiro Yamada	help
15637744ccdbSTom Lendacky	  Say yes to have system memory encrypted by default if running on
15647744ccdbSTom Lendacky	  an AMD processor that supports Secure Memory Encryption (SME).
15657744ccdbSTom Lendacky
15667744ccdbSTom Lendacky	  If set to Y, then the encryption of system memory can be
15677744ccdbSTom Lendacky	  deactivated with the mem_encrypt=off command line option.
15687744ccdbSTom Lendacky
15697744ccdbSTom Lendacky	  If set to N, then the encryption of system memory can be
15707744ccdbSTom Lendacky	  activated with the mem_encrypt=on command line option.
15717744ccdbSTom Lendacky
1572506f1d07SSam Ravnborg# Common NUMA Features
1573506f1d07SSam Ravnborgconfig NUMA
1574e133f6eaSRandy Dunlap	bool "NUMA Memory Allocation and Scheduler Support"
1575506f1d07SSam Ravnborg	depends on SMP
1576b5660ba7SH. Peter Anvin	depends on X86_64 || (X86_32 && HIGHMEM64G && X86_BIGSMP)
1577b5660ba7SH. Peter Anvin	default y if X86_BIGSMP
15787ecd19cfSKefeng Wang	select USE_PERCPU_NUMA_NODE_ID
1579a7f7f624SMasahiro Yamada	help
1580e133f6eaSRandy Dunlap	  Enable NUMA (Non-Uniform Memory Access) support.
1581fd51b2d7SKOSAKI Motohiro
1582506f1d07SSam Ravnborg	  The kernel will try to allocate memory used by a CPU on the
1583506f1d07SSam Ravnborg	  local memory controller of the CPU and add some more
1584506f1d07SSam Ravnborg	  NUMA awareness to the kernel.
1585506f1d07SSam Ravnborg
1586c280ea5eSIngo Molnar	  For 64-bit this is recommended if the system is Intel Core i7
1587fd51b2d7SKOSAKI Motohiro	  (or later), AMD Opteron, or EM64T NUMA.
1588fd51b2d7SKOSAKI Motohiro
1589b5660ba7SH. Peter Anvin	  For 32-bit this is only needed if you boot a 32-bit
15907cf6c945SDavid Rientjes	  kernel on a 64-bit NUMA platform.
1591fd51b2d7SKOSAKI Motohiro
1592fd51b2d7SKOSAKI Motohiro	  Otherwise, you should say N.
1593506f1d07SSam Ravnborg
1594eec1d4faSHans Rosenfeldconfig AMD_NUMA
15953c2362e6SHarvey Harrison	def_bool y
15963c2362e6SHarvey Harrison	prompt "Old style AMD Opteron NUMA detection"
15975da0ef9aSTejun Heo	depends on X86_64 && NUMA && PCI
1598a7f7f624SMasahiro Yamada	help
1599eec1d4faSHans Rosenfeld	  Enable AMD NUMA node topology detection.  You should say Y here if
1600eec1d4faSHans Rosenfeld	  you have a multi processor AMD system. This uses an old method to
1601eec1d4faSHans Rosenfeld	  read the NUMA configuration directly from the builtin Northbridge
1602eec1d4faSHans Rosenfeld	  of Opteron. It is recommended to use X86_64_ACPI_NUMA instead,
1603eec1d4faSHans Rosenfeld	  which also takes priority if both are compiled in.
1604506f1d07SSam Ravnborg
1605506f1d07SSam Ravnborgconfig X86_64_ACPI_NUMA
16063c2362e6SHarvey Harrison	def_bool y
16073c2362e6SHarvey Harrison	prompt "ACPI NUMA detection"
1608506f1d07SSam Ravnborg	depends on X86_64 && NUMA && ACPI && PCI
1609506f1d07SSam Ravnborg	select ACPI_NUMA
1610a7f7f624SMasahiro Yamada	help
1611506f1d07SSam Ravnborg	  Enable ACPI SRAT based node topology detection.
1612506f1d07SSam Ravnborg
1613506f1d07SSam Ravnborgconfig NUMA_EMU
1614506f1d07SSam Ravnborg	bool "NUMA emulation"
16151b7e03efSTejun Heo	depends on NUMA
1616a7f7f624SMasahiro Yamada	help
1617506f1d07SSam Ravnborg	  Enable NUMA emulation. A flat machine will be split
1618506f1d07SSam Ravnborg	  into virtual nodes when booted with "numa=fake=N", where N is the
1619506f1d07SSam Ravnborg	  number of nodes. This is only useful for debugging.
1620506f1d07SSam Ravnborg
1621506f1d07SSam Ravnborgconfig NODES_SHIFT
1622d25e26b6SLinus Torvalds	int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP
162351591e31SDavid Rientjes	range 1 10
162451591e31SDavid Rientjes	default "10" if MAXSMP
1625506f1d07SSam Ravnborg	default "6" if X86_64
1626506f1d07SSam Ravnborg	default "3"
1627a9ee6cf5SMike Rapoport	depends on NUMA
1628a7f7f624SMasahiro Yamada	help
16291184dc2fSMike Travis	  Specify the maximum number of NUMA Nodes available on the target
1630692105b8SMatt LaPlante	  system.  Increases memory reserved to accommodate various tables.
1631506f1d07SSam Ravnborg
1632506f1d07SSam Ravnborgconfig ARCH_FLATMEM_ENABLE
1633506f1d07SSam Ravnborg	def_bool y
16343b16651fSTejun Heo	depends on X86_32 && !NUMA
1635506f1d07SSam Ravnborg
1636506f1d07SSam Ravnborgconfig ARCH_SPARSEMEM_ENABLE
1637506f1d07SSam Ravnborg	def_bool y
16386ea30386SKees Cook	depends on X86_64 || NUMA || X86_32 || X86_32_NON_STANDARD
1639506f1d07SSam Ravnborg	select SPARSEMEM_STATIC if X86_32
1640506f1d07SSam Ravnborg	select SPARSEMEM_VMEMMAP_ENABLE if X86_64
1641506f1d07SSam Ravnborg
16423b16651fSTejun Heoconfig ARCH_SPARSEMEM_DEFAULT
16436ad57f7fSMike Rapoport	def_bool X86_64 || (NUMA && X86_32)
16443b16651fSTejun Heo
1645506f1d07SSam Ravnborgconfig ARCH_SELECT_MEMORY_MODEL
1646506f1d07SSam Ravnborg	def_bool y
1647b263295dSChristoph Lameter	depends on ARCH_SPARSEMEM_ENABLE
1648506f1d07SSam Ravnborg
1649506f1d07SSam Ravnborgconfig ARCH_MEMORY_PROBE
1650a0842b70SToshi Kani	bool "Enable sysfs memory/probe interface"
16515c11f00bSDavid Hildenbrand	depends on MEMORY_HOTPLUG
1652a0842b70SToshi Kani	help
1653a0842b70SToshi Kani	  This option enables a sysfs memory/probe interface for testing.
1654cb1aaebeSMauro Carvalho Chehab	  See Documentation/admin-guide/mm/memory-hotplug.rst for more information.
1655a0842b70SToshi Kani	  If you are unsure how to answer this question, answer N.
1656506f1d07SSam Ravnborg
16573b16651fSTejun Heoconfig ARCH_PROC_KCORE_TEXT
16583b16651fSTejun Heo	def_bool y
16593b16651fSTejun Heo	depends on X86_64 && PROC_KCORE
16603b16651fSTejun Heo
1661a29815a3SAvi Kivityconfig ILLEGAL_POINTER_VALUE
1662a29815a3SAvi Kivity	hex
1663a29815a3SAvi Kivity	default 0 if X86_32
1664a29815a3SAvi Kivity	default 0xdead000000000000 if X86_64
1665a29815a3SAvi Kivity
16667a67832cSDan Williamsconfig X86_PMEM_LEGACY_DEVICE
16677a67832cSDan Williams	bool
16687a67832cSDan Williams
1669ec776ef6SChristoph Hellwigconfig X86_PMEM_LEGACY
16707a67832cSDan Williams	tristate "Support non-standard NVDIMMs and ADR protected memory"
16719f53f9faSDan Williams	depends on PHYS_ADDR_T_64BIT
16729f53f9faSDan Williams	depends on BLK_DEV
16737a67832cSDan Williams	select X86_PMEM_LEGACY_DEVICE
16747b27a862SDan Williams	select NUMA_KEEP_MEMINFO if NUMA
16759f53f9faSDan Williams	select LIBNVDIMM
1676ec776ef6SChristoph Hellwig	help
1677ec776ef6SChristoph Hellwig	  Treat memory marked using the non-standard e820 type of 12 as used
1678ec776ef6SChristoph Hellwig	  by the Intel Sandy Bridge-EP reference BIOS as protected memory.
1679ec776ef6SChristoph Hellwig	  The kernel will offer these regions to the 'pmem' driver so
1680ec776ef6SChristoph Hellwig	  they can be used for persistent storage.
1681ec776ef6SChristoph Hellwig
1682ec776ef6SChristoph Hellwig	  Say Y if unsure.
1683ec776ef6SChristoph Hellwig
1684506f1d07SSam Ravnborgconfig HIGHPTE
1685506f1d07SSam Ravnborg	bool "Allocate 3rd-level pagetables from highmem"
16866fc108a0SJan Beulich	depends on HIGHMEM
1687a7f7f624SMasahiro Yamada	help
1688506f1d07SSam Ravnborg	  The VM uses one page table entry for each page of physical memory.
1689506f1d07SSam Ravnborg	  For systems with a lot of RAM, this can be wasteful of precious
1690506f1d07SSam Ravnborg	  low memory.  Setting this option will put user-space page table
1691506f1d07SSam Ravnborg	  entries in high memory.
1692506f1d07SSam Ravnborg
16939f077871SJeremy Fitzhardingeconfig X86_CHECK_BIOS_CORRUPTION
16949f077871SJeremy Fitzhardinge	bool "Check for low memory corruption"
1695a7f7f624SMasahiro Yamada	help
16969f077871SJeremy Fitzhardinge	  Periodically check for memory corruption in low memory, which
16979f077871SJeremy Fitzhardinge	  is suspected to be caused by BIOS.  Even when enabled in the
16989f077871SJeremy Fitzhardinge	  configuration, it is disabled at runtime.  Enable it by
16999f077871SJeremy Fitzhardinge	  setting "memory_corruption_check=1" on the kernel command
17009f077871SJeremy Fitzhardinge	  line.  By default it scans the low 64k of memory every 60
17019f077871SJeremy Fitzhardinge	  seconds; see the memory_corruption_check_size and
17029f077871SJeremy Fitzhardinge	  memory_corruption_check_period parameters in
17038c27ceffSMauro Carvalho Chehab	  Documentation/admin-guide/kernel-parameters.rst to adjust this.
17049f077871SJeremy Fitzhardinge
17059f077871SJeremy Fitzhardinge	  When enabled with the default parameters, this option has
17069f077871SJeremy Fitzhardinge	  almost no overhead, as it reserves a relatively small amount
17079f077871SJeremy Fitzhardinge	  of memory and scans it infrequently.  It both detects corruption
17089f077871SJeremy Fitzhardinge	  and prevents it from affecting the running system.
17099f077871SJeremy Fitzhardinge
17109f077871SJeremy Fitzhardinge	  It is, however, intended as a diagnostic tool; if repeatable
17119f077871SJeremy Fitzhardinge	  BIOS-originated corruption always affects the same memory,
17129f077871SJeremy Fitzhardinge	  you can use memmap= to prevent the kernel from using that
17139f077871SJeremy Fitzhardinge	  memory.
17149f077871SJeremy Fitzhardinge
1715c885df50SJeremy Fitzhardingeconfig X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK
1716c885df50SJeremy Fitzhardinge	bool "Set the default setting of memory_corruption_check"
1717c885df50SJeremy Fitzhardinge	depends on X86_CHECK_BIOS_CORRUPTION
1718c885df50SJeremy Fitzhardinge	default y
1719a7f7f624SMasahiro Yamada	help
1720c885df50SJeremy Fitzhardinge	  Set whether the default state of memory_corruption_check is
1721c885df50SJeremy Fitzhardinge	  on or off.
1722c885df50SJeremy Fitzhardinge
1723506f1d07SSam Ravnborgconfig MATH_EMULATION
1724506f1d07SSam Ravnborg	bool
1725a5b9e5a2SAndy Lutomirski	depends on MODIFY_LDT_SYSCALL
172687d6021bSArnd Bergmann	prompt "Math emulation" if X86_32 && (M486SX || MELAN)
1727a7f7f624SMasahiro Yamada	help
1728506f1d07SSam Ravnborg	  Linux can emulate a math coprocessor (used for floating point
1729506f1d07SSam Ravnborg	  operations) if you don't have one. 486DX and Pentium processors have
1730506f1d07SSam Ravnborg	  a math coprocessor built in, 486SX and 386 do not, unless you added
1731506f1d07SSam Ravnborg	  a 487DX or 387, respectively. (The messages during boot time can
1732506f1d07SSam Ravnborg	  give you some hints here ["man dmesg"].) Everyone needs either a
1733506f1d07SSam Ravnborg	  coprocessor or this emulation.
1734506f1d07SSam Ravnborg
1735506f1d07SSam Ravnborg	  If you don't have a math coprocessor, you need to say Y here; if you
1736506f1d07SSam Ravnborg	  say Y here even though you have a coprocessor, the coprocessor will
1737506f1d07SSam Ravnborg	  be used nevertheless. (This behavior can be changed with the kernel
1738506f1d07SSam Ravnborg	  command line option "no387", which comes handy if your coprocessor
1739506f1d07SSam Ravnborg	  is broken. Try "man bootparam" or see the documentation of your boot
1740506f1d07SSam Ravnborg	  loader (lilo or loadlin) about how to pass options to the kernel at
1741506f1d07SSam Ravnborg	  boot time.) This means that it is a good idea to say Y here if you
1742506f1d07SSam Ravnborg	  intend to use this kernel on different machines.
1743506f1d07SSam Ravnborg
1744506f1d07SSam Ravnborg	  More information about the internals of the Linux math coprocessor
1745506f1d07SSam Ravnborg	  emulation can be found in <file:arch/x86/math-emu/README>.
1746506f1d07SSam Ravnborg
1747506f1d07SSam Ravnborg	  If you are not sure, say Y; apart from resulting in a 66 KB bigger
1748506f1d07SSam Ravnborg	  kernel, it won't hurt.
1749506f1d07SSam Ravnborg
1750506f1d07SSam Ravnborgconfig MTRR
17516fc108a0SJan Beulich	def_bool y
17526a108a14SDavid Rientjes	prompt "MTRR (Memory Type Range Register) support" if EXPERT
1753a7f7f624SMasahiro Yamada	help
1754506f1d07SSam Ravnborg	  On Intel P6 family processors (Pentium Pro, Pentium II and later)
1755506f1d07SSam Ravnborg	  the Memory Type Range Registers (MTRRs) may be used to control
1756506f1d07SSam Ravnborg	  processor access to memory ranges. This is most useful if you have
1757506f1d07SSam Ravnborg	  a video (VGA) card on a PCI or AGP bus. Enabling write-combining
1758506f1d07SSam Ravnborg	  allows bus write transfers to be combined into a larger transfer
1759506f1d07SSam Ravnborg	  before bursting over the PCI/AGP bus. This can increase performance
1760506f1d07SSam Ravnborg	  of image write operations 2.5 times or more. Saying Y here creates a
1761506f1d07SSam Ravnborg	  /proc/mtrr file which may be used to manipulate your processor's
1762506f1d07SSam Ravnborg	  MTRRs. Typically the X server should use this.
1763506f1d07SSam Ravnborg
1764506f1d07SSam Ravnborg	  This code has a reasonably generic interface so that similar
1765506f1d07SSam Ravnborg	  control registers on other processors can be easily supported
1766506f1d07SSam Ravnborg	  as well:
1767506f1d07SSam Ravnborg
1768506f1d07SSam Ravnborg	  The Cyrix 6x86, 6x86MX and M II processors have Address Range
1769506f1d07SSam Ravnborg	  Registers (ARRs) which provide a similar functionality to MTRRs. For
1770506f1d07SSam Ravnborg	  these, the ARRs are used to emulate the MTRRs.
1771506f1d07SSam Ravnborg	  The AMD K6-2 (stepping 8 and above) and K6-3 processors have two
1772506f1d07SSam Ravnborg	  MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing
1773506f1d07SSam Ravnborg	  write-combining. All of these processors are supported by this code
1774506f1d07SSam Ravnborg	  and it makes sense to say Y here if you have one of them.
1775506f1d07SSam Ravnborg
1776506f1d07SSam Ravnborg	  Saying Y here also fixes a problem with buggy SMP BIOSes which only
1777506f1d07SSam Ravnborg	  set the MTRRs for the boot CPU and not for the secondary CPUs. This
1778506f1d07SSam Ravnborg	  can lead to all sorts of problems, so it's good to say Y here.
1779506f1d07SSam Ravnborg
1780506f1d07SSam Ravnborg	  You can safely say Y even if your machine doesn't have MTRRs, you'll
1781506f1d07SSam Ravnborg	  just add about 9 KB to your kernel.
1782506f1d07SSam Ravnborg
1783cb1aaebeSMauro Carvalho Chehab	  See <file:Documentation/x86/mtrr.rst> for more information.
1784506f1d07SSam Ravnborg
178595ffa243SYinghai Luconfig MTRR_SANITIZER
17862ffb3501SYinghai Lu	def_bool y
178795ffa243SYinghai Lu	prompt "MTRR cleanup support"
178895ffa243SYinghai Lu	depends on MTRR
1789a7f7f624SMasahiro Yamada	help
1790aba3728cSThomas Gleixner	  Convert MTRR layout from continuous to discrete, so X drivers can
1791aba3728cSThomas Gleixner	  add writeback entries.
179295ffa243SYinghai Lu
1793aba3728cSThomas Gleixner	  Can be disabled with disable_mtrr_cleanup on the kernel command line.
1794692105b8SMatt LaPlante	  The largest mtrr entry size for a continuous block can be set with
1795aba3728cSThomas Gleixner	  mtrr_chunk_size.
179695ffa243SYinghai Lu
17972ffb3501SYinghai Lu	  If unsure, say Y.
179895ffa243SYinghai Lu
179995ffa243SYinghai Luconfig MTRR_SANITIZER_ENABLE_DEFAULT
1800f5098d62SYinghai Lu	int "MTRR cleanup enable value (0-1)"
1801f5098d62SYinghai Lu	range 0 1
1802f5098d62SYinghai Lu	default "0"
180395ffa243SYinghai Lu	depends on MTRR_SANITIZER
1804a7f7f624SMasahiro Yamada	help
1805f5098d62SYinghai Lu	  Enable mtrr cleanup default value
180695ffa243SYinghai Lu
180712031a62SYinghai Luconfig MTRR_SANITIZER_SPARE_REG_NR_DEFAULT
180812031a62SYinghai Lu	int "MTRR cleanup spare reg num (0-7)"
180912031a62SYinghai Lu	range 0 7
181012031a62SYinghai Lu	default "1"
181112031a62SYinghai Lu	depends on MTRR_SANITIZER
1812a7f7f624SMasahiro Yamada	help
181312031a62SYinghai Lu	  mtrr cleanup spare entries default, it can be changed via
1814aba3728cSThomas Gleixner	  mtrr_spare_reg_nr=N on the kernel command line.
181512031a62SYinghai Lu
18162e5d9c85Svenkatesh.pallipadi@intel.comconfig X86_PAT
18176fc108a0SJan Beulich	def_bool y
18186a108a14SDavid Rientjes	prompt "x86 PAT support" if EXPERT
18192a8a2719SIngo Molnar	depends on MTRR
1820a7f7f624SMasahiro Yamada	help
18212e5d9c85Svenkatesh.pallipadi@intel.com	  Use PAT attributes to setup page level cache control.
1822042b78e4SVenki Pallipadi
18232e5d9c85Svenkatesh.pallipadi@intel.com	  PATs are the modern equivalents of MTRRs and are much more
18242e5d9c85Svenkatesh.pallipadi@intel.com	  flexible than MTRRs.
18252e5d9c85Svenkatesh.pallipadi@intel.com
18262e5d9c85Svenkatesh.pallipadi@intel.com	  Say N here if you see bootup problems (boot crash, boot hang,
1827042b78e4SVenki Pallipadi	  spontaneous reboots) or a non-working video driver.
18282e5d9c85Svenkatesh.pallipadi@intel.com
18292e5d9c85Svenkatesh.pallipadi@intel.com	  If unsure, say Y.
18302e5d9c85Svenkatesh.pallipadi@intel.com
183146cf98cdSVenkatesh Pallipadiconfig ARCH_USES_PG_UNCACHED
183246cf98cdSVenkatesh Pallipadi	def_bool y
183346cf98cdSVenkatesh Pallipadi	depends on X86_PAT
183446cf98cdSVenkatesh Pallipadi
1835628c6246SH. Peter Anvinconfig ARCH_RANDOM
1836628c6246SH. Peter Anvin	def_bool y
1837628c6246SH. Peter Anvin	prompt "x86 architectural random number generator" if EXPERT
1838a7f7f624SMasahiro Yamada	help
1839628c6246SH. Peter Anvin	  Enable the x86 architectural RDRAND instruction
1840628c6246SH. Peter Anvin	  (Intel Bull Mountain technology) to generate random numbers.
1841628c6246SH. Peter Anvin	  If supported, this is a high bandwidth, cryptographically
1842628c6246SH. Peter Anvin	  secure hardware random number generator.
1843628c6246SH. Peter Anvin
184451ae4a2dSH. Peter Anvinconfig X86_SMAP
184551ae4a2dSH. Peter Anvin	def_bool y
184651ae4a2dSH. Peter Anvin	prompt "Supervisor Mode Access Prevention" if EXPERT
1847a7f7f624SMasahiro Yamada	help
184851ae4a2dSH. Peter Anvin	  Supervisor Mode Access Prevention (SMAP) is a security
184951ae4a2dSH. Peter Anvin	  feature in newer Intel processors.  There is a small
185051ae4a2dSH. Peter Anvin	  performance cost if this enabled and turned on; there is
185151ae4a2dSH. Peter Anvin	  also a small increase in the kernel size if this is enabled.
185251ae4a2dSH. Peter Anvin
185351ae4a2dSH. Peter Anvin	  If unsure, say Y.
185451ae4a2dSH. Peter Anvin
1855b971880fSBabu Mogerconfig X86_UMIP
1856796ebc81SRicardo Neri	def_bool y
1857b971880fSBabu Moger	prompt "User Mode Instruction Prevention" if EXPERT
1858a7f7f624SMasahiro Yamada	help
1859b971880fSBabu Moger	  User Mode Instruction Prevention (UMIP) is a security feature in
1860b971880fSBabu Moger	  some x86 processors. If enabled, a general protection fault is
1861b971880fSBabu Moger	  issued if the SGDT, SLDT, SIDT, SMSW or STR instructions are
1862b971880fSBabu Moger	  executed in user mode. These instructions unnecessarily expose
1863b971880fSBabu Moger	  information about the hardware state.
1864796ebc81SRicardo Neri
1865796ebc81SRicardo Neri	  The vast majority of applications do not use these instructions.
1866796ebc81SRicardo Neri	  For the very few that do, software emulation is provided in
1867796ebc81SRicardo Neri	  specific cases in protected and virtual-8086 modes. Emulated
1868796ebc81SRicardo Neri	  results are dummy.
1869aa35f896SRicardo Neri
187035e97790SDave Hansenconfig X86_INTEL_MEMORY_PROTECTION_KEYS
187138f3e775SBabu Moger	prompt "Memory Protection Keys"
187235e97790SDave Hansen	def_bool y
1873284244a9SDave Hansen	# Note: only available in 64-bit mode
187438f3e775SBabu Moger	depends on X86_64 && (CPU_SUP_INTEL || CPU_SUP_AMD)
187552c8e601SIngo Molnar	select ARCH_USES_HIGH_VMA_FLAGS
187652c8e601SIngo Molnar	select ARCH_HAS_PKEYS
1877a7f7f624SMasahiro Yamada	help
1878284244a9SDave Hansen	  Memory Protection Keys provides a mechanism for enforcing
1879284244a9SDave Hansen	  page-based protections, but without requiring modification of the
1880284244a9SDave Hansen	  page tables when an application changes protection domains.
1881284244a9SDave Hansen
18821eecbcdcSMauro Carvalho Chehab	  For details, see Documentation/core-api/protection-keys.rst
1883284244a9SDave Hansen
1884284244a9SDave Hansen	  If unsure, say y.
188535e97790SDave Hansen
1886db616173SMichal Hockochoice
1887db616173SMichal Hocko	prompt "TSX enable mode"
1888db616173SMichal Hocko	depends on CPU_SUP_INTEL
1889db616173SMichal Hocko	default X86_INTEL_TSX_MODE_OFF
1890db616173SMichal Hocko	help
1891db616173SMichal Hocko	  Intel's TSX (Transactional Synchronization Extensions) feature
1892db616173SMichal Hocko	  allows to optimize locking protocols through lock elision which
1893db616173SMichal Hocko	  can lead to a noticeable performance boost.
1894db616173SMichal Hocko
1895db616173SMichal Hocko	  On the other hand it has been shown that TSX can be exploited
1896db616173SMichal Hocko	  to form side channel attacks (e.g. TAA) and chances are there
1897db616173SMichal Hocko	  will be more of those attacks discovered in the future.
1898db616173SMichal Hocko
1899db616173SMichal Hocko	  Therefore TSX is not enabled by default (aka tsx=off). An admin
1900db616173SMichal Hocko	  might override this decision by tsx=on the command line parameter.
1901db616173SMichal Hocko	  Even with TSX enabled, the kernel will attempt to enable the best
1902db616173SMichal Hocko	  possible TAA mitigation setting depending on the microcode available
1903db616173SMichal Hocko	  for the particular machine.
1904db616173SMichal Hocko
1905db616173SMichal Hocko	  This option allows to set the default tsx mode between tsx=on, =off
1906db616173SMichal Hocko	  and =auto. See Documentation/admin-guide/kernel-parameters.txt for more
1907db616173SMichal Hocko	  details.
1908db616173SMichal Hocko
1909db616173SMichal Hocko	  Say off if not sure, auto if TSX is in use but it should be used on safe
1910db616173SMichal Hocko	  platforms or on if TSX is in use and the security aspect of tsx is not
1911db616173SMichal Hocko	  relevant.
1912db616173SMichal Hocko
1913db616173SMichal Hockoconfig X86_INTEL_TSX_MODE_OFF
1914db616173SMichal Hocko	bool "off"
1915db616173SMichal Hocko	help
1916db616173SMichal Hocko	  TSX is disabled if possible - equals to tsx=off command line parameter.
1917db616173SMichal Hocko
1918db616173SMichal Hockoconfig X86_INTEL_TSX_MODE_ON
1919db616173SMichal Hocko	bool "on"
1920db616173SMichal Hocko	help
1921db616173SMichal Hocko	  TSX is always enabled on TSX capable HW - equals the tsx=on command
1922db616173SMichal Hocko	  line parameter.
1923db616173SMichal Hocko
1924db616173SMichal Hockoconfig X86_INTEL_TSX_MODE_AUTO
1925db616173SMichal Hocko	bool "auto"
1926db616173SMichal Hocko	help
1927db616173SMichal Hocko	  TSX is enabled on TSX capable HW that is believed to be safe against
1928db616173SMichal Hocko	  side channel attacks- equals the tsx=auto command line parameter.
1929db616173SMichal Hockoendchoice
1930db616173SMichal Hocko
1931e7e05452SSean Christophersonconfig X86_SGX
1932e7e05452SSean Christopherson	bool "Software Guard eXtensions (SGX)"
1933e7e05452SSean Christopherson	depends on X86_64 && CPU_SUP_INTEL
1934e7e05452SSean Christopherson	depends on CRYPTO=y
1935e7e05452SSean Christopherson	depends on CRYPTO_SHA256=y
1936e7e05452SSean Christopherson	select SRCU
1937e7e05452SSean Christopherson	select MMU_NOTIFIER
1938901ddbb9SJarkko Sakkinen	select NUMA_KEEP_MEMINFO if NUMA
193940e0e784STony Luck	select XARRAY_MULTI
1940e7e05452SSean Christopherson	help
1941e7e05452SSean Christopherson	  Intel(R) Software Guard eXtensions (SGX) is a set of CPU instructions
1942e7e05452SSean Christopherson	  that can be used by applications to set aside private regions of code
1943e7e05452SSean Christopherson	  and data, referred to as enclaves. An enclave's private memory can
1944e7e05452SSean Christopherson	  only be accessed by code running within the enclave. Accesses from
1945e7e05452SSean Christopherson	  outside the enclave, including other enclaves, are disallowed by
1946e7e05452SSean Christopherson	  hardware.
1947e7e05452SSean Christopherson
1948e7e05452SSean Christopherson	  If unsure, say N.
1949e7e05452SSean Christopherson
1950506f1d07SSam Ravnborgconfig EFI
19519ba16087SJan Beulich	bool "EFI runtime service support"
19525b83683fSHuang, Ying	depends on ACPI
1953f6ce5002SSergey Vlasov	select UCS2_STRING
1954022ee6c5SArd Biesheuvel	select EFI_RUNTIME_WRAPPERS
19551ff2fc02STom Lendacky	select ARCH_USE_MEMREMAP_PROT
1956a7f7f624SMasahiro Yamada	help
19578b2cb7a8SHuang, Ying	  This enables the kernel to use EFI runtime services that are
1958506f1d07SSam Ravnborg	  available (such as the EFI variable services).
1959506f1d07SSam Ravnborg
19608b2cb7a8SHuang, Ying	  This option is only useful on systems that have EFI firmware.
19618b2cb7a8SHuang, Ying	  In addition, you should use the latest ELILO loader available
19628b2cb7a8SHuang, Ying	  at <http://elilo.sourceforge.net> in order to take advantage
19638b2cb7a8SHuang, Ying	  of EFI runtime services. However, even with this option, the
19648b2cb7a8SHuang, Ying	  resultant kernel should continue to boot on existing non-EFI
19658b2cb7a8SHuang, Ying	  platforms.
1966506f1d07SSam Ravnborg
1967291f3632SMatt Flemingconfig EFI_STUB
1968291f3632SMatt Fleming	bool "EFI stub support"
1969c6dbd3e5SPeter Zijlstra	depends on EFI
19708f24f8c2SArd Biesheuvel	depends on $(cc-option,-mabi=ms) || X86_32
19717b2a583aSMatt Fleming	select RELOCATABLE
1972a7f7f624SMasahiro Yamada	help
1973291f3632SMatt Fleming	  This kernel feature allows a bzImage to be loaded directly
1974291f3632SMatt Fleming	  by EFI firmware without the use of a bootloader.
1975291f3632SMatt Fleming
19764f4cfa6cSMauro Carvalho Chehab	  See Documentation/admin-guide/efi-stub.rst for more information.
19770c759662SMatt Fleming
19787d453eeeSMatt Flemingconfig EFI_MIXED
19797d453eeeSMatt Fleming	bool "EFI mixed-mode support"
19807d453eeeSMatt Fleming	depends on EFI_STUB && X86_64
1981a7f7f624SMasahiro Yamada	help
19827d453eeeSMatt Fleming	   Enabling this feature allows a 64-bit kernel to be booted
19837d453eeeSMatt Fleming	   on a 32-bit firmware, provided that your CPU supports 64-bit
19847d453eeeSMatt Fleming	   mode.
19857d453eeeSMatt Fleming
19867d453eeeSMatt Fleming	   Note that it is not possible to boot a mixed-mode enabled
19877d453eeeSMatt Fleming	   kernel via the EFI boot stub - a bootloader that supports
19887d453eeeSMatt Fleming	   the EFI handover protocol must be used.
19897d453eeeSMatt Fleming
19907d453eeeSMatt Fleming	   If unsure, say N.
19917d453eeeSMatt Fleming
19928636a1f9SMasahiro Yamadasource "kernel/Kconfig.hz"
1993506f1d07SSam Ravnborg
1994506f1d07SSam Ravnborgconfig KEXEC
1995506f1d07SSam Ravnborg	bool "kexec system call"
19962965faa5SDave Young	select KEXEC_CORE
1997a7f7f624SMasahiro Yamada	help
1998506f1d07SSam Ravnborg	  kexec is a system call that implements the ability to shutdown your
1999506f1d07SSam Ravnborg	  current kernel, and to start another kernel.  It is like a reboot
2000506f1d07SSam Ravnborg	  but it is independent of the system firmware.   And like a reboot
2001506f1d07SSam Ravnborg	  you can start any kernel with it, not just Linux.
2002506f1d07SSam Ravnborg
2003506f1d07SSam Ravnborg	  The name comes from the similarity to the exec system call.
2004506f1d07SSam Ravnborg
2005506f1d07SSam Ravnborg	  It is an ongoing process to be certain the hardware in a machine
2006506f1d07SSam Ravnborg	  is properly shutdown, so do not be surprised if this code does not
2007bf220695SGeert Uytterhoeven	  initially work for you.  As of this writing the exact hardware
2008bf220695SGeert Uytterhoeven	  interface is strongly in flux, so no good recommendation can be
2009bf220695SGeert Uytterhoeven	  made.
2010506f1d07SSam Ravnborg
201174ca317cSVivek Goyalconfig KEXEC_FILE
201274ca317cSVivek Goyal	bool "kexec file based system call"
20132965faa5SDave Young	select KEXEC_CORE
201474ca317cSVivek Goyal	select BUILD_BIN2C
201574ca317cSVivek Goyal	depends on X86_64
201674ca317cSVivek Goyal	depends on CRYPTO=y
201774ca317cSVivek Goyal	depends on CRYPTO_SHA256=y
2018a7f7f624SMasahiro Yamada	help
201974ca317cSVivek Goyal	  This is new version of kexec system call. This system call is
202074ca317cSVivek Goyal	  file based and takes file descriptors as system call argument
202174ca317cSVivek Goyal	  for kernel and initramfs as opposed to list of segments as
202274ca317cSVivek Goyal	  accepted by previous system call.
202374ca317cSVivek Goyal
2024b799a09fSAKASHI Takahiroconfig ARCH_HAS_KEXEC_PURGATORY
2025b799a09fSAKASHI Takahiro	def_bool KEXEC_FILE
2026b799a09fSAKASHI Takahiro
202799d5cadfSJiri Bohacconfig KEXEC_SIG
20288e7d8381SVivek Goyal	bool "Verify kernel signature during kexec_file_load() syscall"
202974ca317cSVivek Goyal	depends on KEXEC_FILE
2030a7f7f624SMasahiro Yamada	help
203199d5cadfSJiri Bohac
203299d5cadfSJiri Bohac	  This option makes the kexec_file_load() syscall check for a valid
203399d5cadfSJiri Bohac	  signature of the kernel image.  The image can still be loaded without
203499d5cadfSJiri Bohac	  a valid signature unless you also enable KEXEC_SIG_FORCE, though if
203599d5cadfSJiri Bohac	  there's a signature that we can check, then it must be valid.
203699d5cadfSJiri Bohac
203799d5cadfSJiri Bohac	  In addition to this option, you need to enable signature
203899d5cadfSJiri Bohac	  verification for the corresponding kernel image type being
203999d5cadfSJiri Bohac	  loaded in order for this to work.
204099d5cadfSJiri Bohac
204199d5cadfSJiri Bohacconfig KEXEC_SIG_FORCE
204299d5cadfSJiri Bohac	bool "Require a valid signature in kexec_file_load() syscall"
204399d5cadfSJiri Bohac	depends on KEXEC_SIG
2044a7f7f624SMasahiro Yamada	help
20458e7d8381SVivek Goyal	  This option makes kernel signature verification mandatory for
2046d8eb8940SBorislav Petkov	  the kexec_file_load() syscall.
20478e7d8381SVivek Goyal
20488e7d8381SVivek Goyalconfig KEXEC_BZIMAGE_VERIFY_SIG
20498e7d8381SVivek Goyal	bool "Enable bzImage signature verification support"
205099d5cadfSJiri Bohac	depends on KEXEC_SIG
20518e7d8381SVivek Goyal	depends on SIGNED_PE_FILE_VERIFICATION
20528e7d8381SVivek Goyal	select SYSTEM_TRUSTED_KEYRING
2053a7f7f624SMasahiro Yamada	help
20548e7d8381SVivek Goyal	  Enable bzImage signature verification support.
20558e7d8381SVivek Goyal
2056506f1d07SSam Ravnborgconfig CRASH_DUMP
205704b69447SPavel Machek	bool "kernel crash dumps"
2058506f1d07SSam Ravnborg	depends on X86_64 || (X86_32 && HIGHMEM)
2059a7f7f624SMasahiro Yamada	help
2060506f1d07SSam Ravnborg	  Generate crash dump after being started by kexec.
2061506f1d07SSam Ravnborg	  This should be normally only set in special crash dump kernels
2062506f1d07SSam Ravnborg	  which are loaded in the main kernel with kexec-tools into
2063506f1d07SSam Ravnborg	  a specially reserved region and then later executed after
2064506f1d07SSam Ravnborg	  a crash by kdump/kexec. The crash dump kernel must be compiled
2065506f1d07SSam Ravnborg	  to a memory address not used by the main kernel or BIOS using
2066506f1d07SSam Ravnborg	  PHYSICAL_START, or it must be built as a relocatable image
2067506f1d07SSam Ravnborg	  (CONFIG_RELOCATABLE=y).
2068330d4810SMauro Carvalho Chehab	  For more details see Documentation/admin-guide/kdump/kdump.rst
2069506f1d07SSam Ravnborg
20703ab83521SHuang Yingconfig KEXEC_JUMP
20716ea30386SKees Cook	bool "kexec jump"
2072fee7b0d8SHuang Ying	depends on KEXEC && HIBERNATION
2073a7f7f624SMasahiro Yamada	help
207489081d17SHuang Ying	  Jump between original kernel and kexeced kernel and invoke
207589081d17SHuang Ying	  code in physical address mode via KEXEC
20763ab83521SHuang Ying
2077506f1d07SSam Ravnborgconfig PHYSICAL_START
20786a108a14SDavid Rientjes	hex "Physical address where the kernel is loaded" if (EXPERT || CRASH_DUMP)
2079ceefccc9SH. Peter Anvin	default "0x1000000"
2080a7f7f624SMasahiro Yamada	help
2081506f1d07SSam Ravnborg	  This gives the physical address where the kernel is loaded.
2082506f1d07SSam Ravnborg
2083506f1d07SSam Ravnborg	  If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then
2084506f1d07SSam Ravnborg	  bzImage will decompress itself to above physical address and
2085506f1d07SSam Ravnborg	  run from there. Otherwise, bzImage will run from the address where
2086506f1d07SSam Ravnborg	  it has been loaded by the boot loader and will ignore above physical
2087506f1d07SSam Ravnborg	  address.
2088506f1d07SSam Ravnborg
2089506f1d07SSam Ravnborg	  In normal kdump cases one does not have to set/change this option
2090506f1d07SSam Ravnborg	  as now bzImage can be compiled as a completely relocatable image
2091506f1d07SSam Ravnborg	  (CONFIG_RELOCATABLE=y) and be used to load and run from a different
2092506f1d07SSam Ravnborg	  address. This option is mainly useful for the folks who don't want
2093506f1d07SSam Ravnborg	  to use a bzImage for capturing the crash dump and want to use a
2094506f1d07SSam Ravnborg	  vmlinux instead. vmlinux is not relocatable hence a kernel needs
2095506f1d07SSam Ravnborg	  to be specifically compiled to run from a specific memory area
2096506f1d07SSam Ravnborg	  (normally a reserved region) and this option comes handy.
2097506f1d07SSam Ravnborg
2098ceefccc9SH. Peter Anvin	  So if you are using bzImage for capturing the crash dump,
2099ceefccc9SH. Peter Anvin	  leave the value here unchanged to 0x1000000 and set
2100ceefccc9SH. Peter Anvin	  CONFIG_RELOCATABLE=y.  Otherwise if you plan to use vmlinux
2101ceefccc9SH. Peter Anvin	  for capturing the crash dump change this value to start of
2102ceefccc9SH. Peter Anvin	  the reserved region.  In other words, it can be set based on
2103ceefccc9SH. Peter Anvin	  the "X" value as specified in the "crashkernel=YM@XM"
2104ceefccc9SH. Peter Anvin	  command line boot parameter passed to the panic-ed
2105330d4810SMauro Carvalho Chehab	  kernel. Please take a look at Documentation/admin-guide/kdump/kdump.rst
2106ceefccc9SH. Peter Anvin	  for more details about crash dumps.
2107506f1d07SSam Ravnborg
2108506f1d07SSam Ravnborg	  Usage of bzImage for capturing the crash dump is recommended as
2109506f1d07SSam Ravnborg	  one does not have to build two kernels. Same kernel can be used
2110506f1d07SSam Ravnborg	  as production kernel and capture kernel. Above option should have
2111506f1d07SSam Ravnborg	  gone away after relocatable bzImage support is introduced. But it
2112506f1d07SSam Ravnborg	  is present because there are users out there who continue to use
2113506f1d07SSam Ravnborg	  vmlinux for dump capture. This option should go away down the
2114506f1d07SSam Ravnborg	  line.
2115506f1d07SSam Ravnborg
2116506f1d07SSam Ravnborg	  Don't change this unless you know what you are doing.
2117506f1d07SSam Ravnborg
2118506f1d07SSam Ravnborgconfig RELOCATABLE
211926717808SH. Peter Anvin	bool "Build a relocatable kernel"
212026717808SH. Peter Anvin	default y
2121a7f7f624SMasahiro Yamada	help
2122506f1d07SSam Ravnborg	  This builds a kernel image that retains relocation information
2123506f1d07SSam Ravnborg	  so it can be loaded someplace besides the default 1MB.
2124506f1d07SSam Ravnborg	  The relocations tend to make the kernel binary about 10% larger,
2125506f1d07SSam Ravnborg	  but are discarded at runtime.
2126506f1d07SSam Ravnborg
2127506f1d07SSam Ravnborg	  One use is for the kexec on panic case where the recovery kernel
2128506f1d07SSam Ravnborg	  must live at a different physical address than the primary
2129506f1d07SSam Ravnborg	  kernel.
2130506f1d07SSam Ravnborg
2131506f1d07SSam Ravnborg	  Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address
2132506f1d07SSam Ravnborg	  it has been loaded at and the compile time physical address
21338ab3820fSKees Cook	  (CONFIG_PHYSICAL_START) is used as the minimum location.
2134506f1d07SSam Ravnborg
21358ab3820fSKees Cookconfig RANDOMIZE_BASE
2136e8581e3dSBaoquan He	bool "Randomize the address of the kernel image (KASLR)"
21378ab3820fSKees Cook	depends on RELOCATABLE
21386807c846SIngo Molnar	default y
2139a7f7f624SMasahiro Yamada	help
2140e8581e3dSBaoquan He	  In support of Kernel Address Space Layout Randomization (KASLR),
2141e8581e3dSBaoquan He	  this randomizes the physical address at which the kernel image
2142e8581e3dSBaoquan He	  is decompressed and the virtual address where the kernel
2143e8581e3dSBaoquan He	  image is mapped, as a security feature that deters exploit
2144e8581e3dSBaoquan He	  attempts relying on knowledge of the location of kernel
2145e8581e3dSBaoquan He	  code internals.
2146e8581e3dSBaoquan He
2147ed9f007eSKees Cook	  On 64-bit, the kernel physical and virtual addresses are
2148ed9f007eSKees Cook	  randomized separately. The physical address will be anywhere
2149ed9f007eSKees Cook	  between 16MB and the top of physical memory (up to 64TB). The
2150ed9f007eSKees Cook	  virtual address will be randomized from 16MB up to 1GB (9 bits
2151ed9f007eSKees Cook	  of entropy). Note that this also reduces the memory space
2152ed9f007eSKees Cook	  available to kernel modules from 1.5GB to 1GB.
2153ed9f007eSKees Cook
2154ed9f007eSKees Cook	  On 32-bit, the kernel physical and virtual addresses are
2155ed9f007eSKees Cook	  randomized together. They will be randomized from 16MB up to
2156ed9f007eSKees Cook	  512MB (8 bits of entropy).
21578ab3820fSKees Cook
2158a653f356SKees Cook	  Entropy is generated using the RDRAND instruction if it is
2159e8581e3dSBaoquan He	  supported. If RDTSC is supported, its value is mixed into
2160e8581e3dSBaoquan He	  the entropy pool as well. If neither RDRAND nor RDTSC are
2161ed9f007eSKees Cook	  supported, then entropy is read from the i8254 timer. The
2162ed9f007eSKees Cook	  usable entropy is limited by the kernel being built using
2163ed9f007eSKees Cook	  2GB addressing, and that PHYSICAL_ALIGN must be at a
2164ed9f007eSKees Cook	  minimum of 2MB. As a result, only 10 bits of entropy are
2165ed9f007eSKees Cook	  theoretically possible, but the implementations are further
2166ed9f007eSKees Cook	  limited due to memory layouts.
2167e8581e3dSBaoquan He
21686807c846SIngo Molnar	  If unsure, say Y.
2169da2b6fb9SKees Cook
21708ab3820fSKees Cook# Relocation on x86 needs some additional build support
2171845adf72SH. Peter Anvinconfig X86_NEED_RELOCS
2172845adf72SH. Peter Anvin	def_bool y
21738ab3820fSKees Cook	depends on RANDOMIZE_BASE || (X86_32 && RELOCATABLE)
2174845adf72SH. Peter Anvin
2175506f1d07SSam Ravnborgconfig PHYSICAL_ALIGN
2176a0215061SKees Cook	hex "Alignment value to which kernel should be aligned"
21778ab3820fSKees Cook	default "0x200000"
2178a0215061SKees Cook	range 0x2000 0x1000000 if X86_32
2179a0215061SKees Cook	range 0x200000 0x1000000 if X86_64
2180a7f7f624SMasahiro Yamada	help
2181506f1d07SSam Ravnborg	  This value puts the alignment restrictions on physical address
2182506f1d07SSam Ravnborg	  where kernel is loaded and run from. Kernel is compiled for an
2183506f1d07SSam Ravnborg	  address which meets above alignment restriction.
2184506f1d07SSam Ravnborg
2185506f1d07SSam Ravnborg	  If bootloader loads the kernel at a non-aligned address and
2186506f1d07SSam Ravnborg	  CONFIG_RELOCATABLE is set, kernel will move itself to nearest
2187506f1d07SSam Ravnborg	  address aligned to above value and run from there.
2188506f1d07SSam Ravnborg
2189506f1d07SSam Ravnborg	  If bootloader loads the kernel at a non-aligned address and
2190506f1d07SSam Ravnborg	  CONFIG_RELOCATABLE is not set, kernel will ignore the run time
2191506f1d07SSam Ravnborg	  load address and decompress itself to the address it has been
2192506f1d07SSam Ravnborg	  compiled for and run from there. The address for which kernel is
2193506f1d07SSam Ravnborg	  compiled already meets above alignment restrictions. Hence the
2194506f1d07SSam Ravnborg	  end result is that kernel runs from a physical address meeting
2195506f1d07SSam Ravnborg	  above alignment restrictions.
2196506f1d07SSam Ravnborg
2197a0215061SKees Cook	  On 32-bit this value must be a multiple of 0x2000. On 64-bit
2198a0215061SKees Cook	  this value must be a multiple of 0x200000.
2199a0215061SKees Cook
2200506f1d07SSam Ravnborg	  Don't change this unless you know what you are doing.
2201506f1d07SSam Ravnborg
2202eedb92abSKirill A. Shutemovconfig DYNAMIC_MEMORY_LAYOUT
2203eedb92abSKirill A. Shutemov	bool
2204a7f7f624SMasahiro Yamada	help
2205eedb92abSKirill A. Shutemov	  This option makes base addresses of vmalloc and vmemmap as well as
2206eedb92abSKirill A. Shutemov	  __PAGE_OFFSET movable during boot.
2207eedb92abSKirill A. Shutemov
22080483e1faSThomas Garnierconfig RANDOMIZE_MEMORY
22090483e1faSThomas Garnier	bool "Randomize the kernel memory sections"
22100483e1faSThomas Garnier	depends on X86_64
22110483e1faSThomas Garnier	depends on RANDOMIZE_BASE
2212eedb92abSKirill A. Shutemov	select DYNAMIC_MEMORY_LAYOUT
22130483e1faSThomas Garnier	default RANDOMIZE_BASE
2214a7f7f624SMasahiro Yamada	help
22150483e1faSThomas Garnier	   Randomizes the base virtual address of kernel memory sections
22160483e1faSThomas Garnier	   (physical memory mapping, vmalloc & vmemmap). This security feature
22170483e1faSThomas Garnier	   makes exploits relying on predictable memory locations less reliable.
22180483e1faSThomas Garnier
22190483e1faSThomas Garnier	   The order of allocations remains unchanged. Entropy is generated in
22200483e1faSThomas Garnier	   the same way as RANDOMIZE_BASE. Current implementation in the optimal
22210483e1faSThomas Garnier	   configuration have in average 30,000 different possible virtual
22220483e1faSThomas Garnier	   addresses for each memory section.
22230483e1faSThomas Garnier
22246807c846SIngo Molnar	   If unsure, say Y.
22250483e1faSThomas Garnier
222690397a41SThomas Garnierconfig RANDOMIZE_MEMORY_PHYSICAL_PADDING
222790397a41SThomas Garnier	hex "Physical memory mapping padding" if EXPERT
222890397a41SThomas Garnier	depends on RANDOMIZE_MEMORY
222990397a41SThomas Garnier	default "0xa" if MEMORY_HOTPLUG
223090397a41SThomas Garnier	default "0x0"
223190397a41SThomas Garnier	range 0x1 0x40 if MEMORY_HOTPLUG
223290397a41SThomas Garnier	range 0x0 0x40
2233a7f7f624SMasahiro Yamada	help
223490397a41SThomas Garnier	   Define the padding in terabytes added to the existing physical
223590397a41SThomas Garnier	   memory size during kernel memory randomization. It is useful
223690397a41SThomas Garnier	   for memory hotplug support but reduces the entropy available for
223790397a41SThomas Garnier	   address randomization.
223890397a41SThomas Garnier
223990397a41SThomas Garnier	   If unsure, leave at the default value.
224090397a41SThomas Garnier
2241506f1d07SSam Ravnborgconfig HOTPLUG_CPU
2242bebd024eSThomas Gleixner	def_bool y
224340b31360SStephen Rothwell	depends on SMP
2244506f1d07SSam Ravnborg
224580aa1dffSFenghua Yuconfig BOOTPARAM_HOTPLUG_CPU0
224680aa1dffSFenghua Yu	bool "Set default setting of cpu0_hotpluggable"
22472c922cd0SKees Cook	depends on HOTPLUG_CPU
2248a7f7f624SMasahiro Yamada	help
224980aa1dffSFenghua Yu	  Set whether default state of cpu0_hotpluggable is on or off.
225080aa1dffSFenghua Yu
225180aa1dffSFenghua Yu	  Say Y here to enable CPU0 hotplug by default. If this switch
225280aa1dffSFenghua Yu	  is turned on, there is no need to give cpu0_hotplug kernel
225380aa1dffSFenghua Yu	  parameter and the CPU0 hotplug feature is enabled by default.
225480aa1dffSFenghua Yu
225580aa1dffSFenghua Yu	  Please note: there are two known CPU0 dependencies if you want
225680aa1dffSFenghua Yu	  to enable the CPU0 hotplug feature either by this switch or by
225780aa1dffSFenghua Yu	  cpu0_hotplug kernel parameter.
225880aa1dffSFenghua Yu
225980aa1dffSFenghua Yu	  First, resume from hibernate or suspend always starts from CPU0.
226080aa1dffSFenghua Yu	  So hibernate and suspend are prevented if CPU0 is offline.
226180aa1dffSFenghua Yu
226280aa1dffSFenghua Yu	  Second dependency is PIC interrupts always go to CPU0. CPU0 can not
226380aa1dffSFenghua Yu	  offline if any interrupt can not migrate out of CPU0. There may
226480aa1dffSFenghua Yu	  be other CPU0 dependencies.
226580aa1dffSFenghua Yu
226680aa1dffSFenghua Yu	  Please make sure the dependencies are under your control before
226780aa1dffSFenghua Yu	  you enable this feature.
226880aa1dffSFenghua Yu
226980aa1dffSFenghua Yu	  Say N if you don't want to enable CPU0 hotplug feature by default.
227080aa1dffSFenghua Yu	  You still can enable the CPU0 hotplug feature at boot by kernel
227180aa1dffSFenghua Yu	  parameter cpu0_hotplug.
227280aa1dffSFenghua Yu
2273a71c8bc5SFenghua Yuconfig DEBUG_HOTPLUG_CPU0
2274a71c8bc5SFenghua Yu	def_bool n
2275a71c8bc5SFenghua Yu	prompt "Debug CPU0 hotplug"
22762c922cd0SKees Cook	depends on HOTPLUG_CPU
2277a7f7f624SMasahiro Yamada	help
2278a71c8bc5SFenghua Yu	  Enabling this option offlines CPU0 (if CPU0 can be offlined) as
2279a71c8bc5SFenghua Yu	  soon as possible and boots up userspace with CPU0 offlined. User
2280a71c8bc5SFenghua Yu	  can online CPU0 back after boot time.
2281a71c8bc5SFenghua Yu
2282a71c8bc5SFenghua Yu	  To debug CPU0 hotplug, you need to enable CPU0 offline/online
2283a71c8bc5SFenghua Yu	  feature by either turning on CONFIG_BOOTPARAM_HOTPLUG_CPU0 during
2284a71c8bc5SFenghua Yu	  compilation or giving cpu0_hotplug kernel parameter at boot.
2285a71c8bc5SFenghua Yu
2286a71c8bc5SFenghua Yu	  If unsure, say N.
2287a71c8bc5SFenghua Yu
2288506f1d07SSam Ravnborgconfig COMPAT_VDSO
2289b0b49f26SAndy Lutomirski	def_bool n
2290b0b49f26SAndy Lutomirski	prompt "Disable the 32-bit vDSO (needed for glibc 2.3.3)"
2291953fee1dSIngo Molnar	depends on COMPAT_32
2292a7f7f624SMasahiro Yamada	help
2293b0b49f26SAndy Lutomirski	  Certain buggy versions of glibc will crash if they are
2294b0b49f26SAndy Lutomirski	  presented with a 32-bit vDSO that is not mapped at the address
2295b0b49f26SAndy Lutomirski	  indicated in its segment table.
2296e84446deSRandy Dunlap
2297b0b49f26SAndy Lutomirski	  The bug was introduced by f866314b89d56845f55e6f365e18b31ec978ec3a
2298b0b49f26SAndy Lutomirski	  and fixed by 3b3ddb4f7db98ec9e912ccdf54d35df4aa30e04a and
2299b0b49f26SAndy Lutomirski	  49ad572a70b8aeb91e57483a11dd1b77e31c4468.  Glibc 2.3.3 is
2300b0b49f26SAndy Lutomirski	  the only released version with the bug, but OpenSUSE 9
2301b0b49f26SAndy Lutomirski	  contains a buggy "glibc 2.3.2".
2302506f1d07SSam Ravnborg
2303b0b49f26SAndy Lutomirski	  The symptom of the bug is that everything crashes on startup, saying:
2304b0b49f26SAndy Lutomirski	  dl_main: Assertion `(void *) ph->p_vaddr == _rtld_local._dl_sysinfo_dso' failed!
2305b0b49f26SAndy Lutomirski
2306b0b49f26SAndy Lutomirski	  Saying Y here changes the default value of the vdso32 boot
2307b0b49f26SAndy Lutomirski	  option from 1 to 0, which turns off the 32-bit vDSO entirely.
2308b0b49f26SAndy Lutomirski	  This works around the glibc bug but hurts performance.
2309b0b49f26SAndy Lutomirski
2310b0b49f26SAndy Lutomirski	  If unsure, say N: if you are compiling your own kernel, you
2311b0b49f26SAndy Lutomirski	  are unlikely to be using a buggy version of glibc.
2312506f1d07SSam Ravnborg
23133dc33bd3SKees Cookchoice
23143dc33bd3SKees Cook	prompt "vsyscall table for legacy applications"
23153dc33bd3SKees Cook	depends on X86_64
2316625b7b7fSAndy Lutomirski	default LEGACY_VSYSCALL_XONLY
23173dc33bd3SKees Cook	help
23183dc33bd3SKees Cook	  Legacy user code that does not know how to find the vDSO expects
23193dc33bd3SKees Cook	  to be able to issue three syscalls by calling fixed addresses in
23203dc33bd3SKees Cook	  kernel space. Since this location is not randomized with ASLR,
23213dc33bd3SKees Cook	  it can be used to assist security vulnerability exploitation.
23223dc33bd3SKees Cook
23233dc33bd3SKees Cook	  This setting can be changed at boot time via the kernel command
2324bd49e16eSAndy Lutomirski	  line parameter vsyscall=[emulate|xonly|none].
23253dc33bd3SKees Cook
23263dc33bd3SKees Cook	  On a system with recent enough glibc (2.14 or newer) and no
23273dc33bd3SKees Cook	  static binaries, you can say None without a performance penalty
23283dc33bd3SKees Cook	  to improve security.
23293dc33bd3SKees Cook
2330bd49e16eSAndy Lutomirski	  If unsure, select "Emulate execution only".
23313dc33bd3SKees Cook
23323dc33bd3SKees Cook	config LEGACY_VSYSCALL_EMULATE
2333bd49e16eSAndy Lutomirski		bool "Full emulation"
23343dc33bd3SKees Cook		help
2335bd49e16eSAndy Lutomirski		  The kernel traps and emulates calls into the fixed vsyscall
2336bd49e16eSAndy Lutomirski		  address mapping. This makes the mapping non-executable, but
2337bd49e16eSAndy Lutomirski		  it still contains readable known contents, which could be
2338bd49e16eSAndy Lutomirski		  used in certain rare security vulnerability exploits. This
2339bd49e16eSAndy Lutomirski		  configuration is recommended when using legacy userspace
2340bd49e16eSAndy Lutomirski		  that still uses vsyscalls along with legacy binary
2341bd49e16eSAndy Lutomirski		  instrumentation tools that require code to be readable.
2342bd49e16eSAndy Lutomirski
2343bd49e16eSAndy Lutomirski		  An example of this type of legacy userspace is running
2344bd49e16eSAndy Lutomirski		  Pin on an old binary that still uses vsyscalls.
2345bd49e16eSAndy Lutomirski
2346bd49e16eSAndy Lutomirski	config LEGACY_VSYSCALL_XONLY
2347bd49e16eSAndy Lutomirski		bool "Emulate execution only"
2348bd49e16eSAndy Lutomirski		help
2349bd49e16eSAndy Lutomirski		  The kernel traps and emulates calls into the fixed vsyscall
2350bd49e16eSAndy Lutomirski		  address mapping and does not allow reads.  This
2351bd49e16eSAndy Lutomirski		  configuration is recommended when userspace might use the
2352bd49e16eSAndy Lutomirski		  legacy vsyscall area but support for legacy binary
2353bd49e16eSAndy Lutomirski		  instrumentation of legacy code is not needed.  It mitigates
2354bd49e16eSAndy Lutomirski		  certain uses of the vsyscall area as an ASLR-bypassing
2355bd49e16eSAndy Lutomirski		  buffer.
23563dc33bd3SKees Cook
23573dc33bd3SKees Cook	config LEGACY_VSYSCALL_NONE
23583dc33bd3SKees Cook		bool "None"
23593dc33bd3SKees Cook		help
23603dc33bd3SKees Cook		  There will be no vsyscall mapping at all. This will
23613dc33bd3SKees Cook		  eliminate any risk of ASLR bypass due to the vsyscall
23623dc33bd3SKees Cook		  fixed address mapping. Attempts to use the vsyscalls
23633dc33bd3SKees Cook		  will be reported to dmesg, so that either old or
23643dc33bd3SKees Cook		  malicious userspace programs can be identified.
23653dc33bd3SKees Cook
23663dc33bd3SKees Cookendchoice
23673dc33bd3SKees Cook
2368516cbf37STim Birdconfig CMDLINE_BOOL
2369516cbf37STim Bird	bool "Built-in kernel command line"
2370a7f7f624SMasahiro Yamada	help
2371516cbf37STim Bird	  Allow for specifying boot arguments to the kernel at
2372516cbf37STim Bird	  build time.  On some systems (e.g. embedded ones), it is
2373516cbf37STim Bird	  necessary or convenient to provide some or all of the
2374516cbf37STim Bird	  kernel boot arguments with the kernel itself (that is,
2375516cbf37STim Bird	  to not rely on the boot loader to provide them.)
2376516cbf37STim Bird
2377516cbf37STim Bird	  To compile command line arguments into the kernel,
2378516cbf37STim Bird	  set this option to 'Y', then fill in the
237969711ca1SSébastien Hinderer	  boot arguments in CONFIG_CMDLINE.
2380516cbf37STim Bird
2381516cbf37STim Bird	  Systems with fully functional boot loaders (i.e. non-embedded)
2382516cbf37STim Bird	  should leave this option set to 'N'.
2383516cbf37STim Bird
2384516cbf37STim Birdconfig CMDLINE
2385516cbf37STim Bird	string "Built-in kernel command string"
2386516cbf37STim Bird	depends on CMDLINE_BOOL
2387516cbf37STim Bird	default ""
2388a7f7f624SMasahiro Yamada	help
2389516cbf37STim Bird	  Enter arguments here that should be compiled into the kernel
2390516cbf37STim Bird	  image and used at boot time.  If the boot loader provides a
2391516cbf37STim Bird	  command line at boot time, it is appended to this string to
2392516cbf37STim Bird	  form the full kernel command line, when the system boots.
2393516cbf37STim Bird
2394516cbf37STim Bird	  However, you can use the CONFIG_CMDLINE_OVERRIDE option to
2395516cbf37STim Bird	  change this behavior.
2396516cbf37STim Bird
2397516cbf37STim Bird	  In most cases, the command line (whether built-in or provided
2398516cbf37STim Bird	  by the boot loader) should specify the device for the root
2399516cbf37STim Bird	  file system.
2400516cbf37STim Bird
2401516cbf37STim Birdconfig CMDLINE_OVERRIDE
2402516cbf37STim Bird	bool "Built-in command line overrides boot loader arguments"
2403645e6466SAnders Roxell	depends on CMDLINE_BOOL && CMDLINE != ""
2404a7f7f624SMasahiro Yamada	help
2405516cbf37STim Bird	  Set this option to 'Y' to have the kernel ignore the boot loader
2406516cbf37STim Bird	  command line, and use ONLY the built-in command line.
2407516cbf37STim Bird
2408516cbf37STim Bird	  This is used to work around broken boot loaders.  This should
2409516cbf37STim Bird	  be set to 'N' under normal conditions.
2410516cbf37STim Bird
2411a5b9e5a2SAndy Lutomirskiconfig MODIFY_LDT_SYSCALL
2412a5b9e5a2SAndy Lutomirski	bool "Enable the LDT (local descriptor table)" if EXPERT
2413a5b9e5a2SAndy Lutomirski	default y
2414a7f7f624SMasahiro Yamada	help
2415a5b9e5a2SAndy Lutomirski	  Linux can allow user programs to install a per-process x86
2416a5b9e5a2SAndy Lutomirski	  Local Descriptor Table (LDT) using the modify_ldt(2) system
2417a5b9e5a2SAndy Lutomirski	  call.  This is required to run 16-bit or segmented code such as
2418a5b9e5a2SAndy Lutomirski	  DOSEMU or some Wine programs.  It is also used by some very old
2419a5b9e5a2SAndy Lutomirski	  threading libraries.
2420a5b9e5a2SAndy Lutomirski
2421a5b9e5a2SAndy Lutomirski	  Enabling this feature adds a small amount of overhead to
2422a5b9e5a2SAndy Lutomirski	  context switches and increases the low-level kernel attack
2423a5b9e5a2SAndy Lutomirski	  surface.  Disabling it removes the modify_ldt(2) system call.
2424a5b9e5a2SAndy Lutomirski
2425a5b9e5a2SAndy Lutomirski	  Saying 'N' here may make sense for embedded or server kernels.
2426a5b9e5a2SAndy Lutomirski
24273aac3ebeSThomas Gleixnerconfig STRICT_SIGALTSTACK_SIZE
24283aac3ebeSThomas Gleixner	bool "Enforce strict size checking for sigaltstack"
24293aac3ebeSThomas Gleixner	depends on DYNAMIC_SIGFRAME
24303aac3ebeSThomas Gleixner	help
24313aac3ebeSThomas Gleixner	  For historical reasons MINSIGSTKSZ is a constant which became
24323aac3ebeSThomas Gleixner	  already too small with AVX512 support. Add a mechanism to
24333aac3ebeSThomas Gleixner	  enforce strict checking of the sigaltstack size against the
24343aac3ebeSThomas Gleixner	  real size of the FPU frame. This option enables the check
24353aac3ebeSThomas Gleixner	  by default. It can also be controlled via the kernel command
24363aac3ebeSThomas Gleixner	  line option 'strict_sas_size' independent of this config
24373aac3ebeSThomas Gleixner	  switch. Enabling it might break existing applications which
24383aac3ebeSThomas Gleixner	  allocate a too small sigaltstack but 'work' because they
24393aac3ebeSThomas Gleixner	  never get a signal delivered.
24403aac3ebeSThomas Gleixner
24413aac3ebeSThomas Gleixner	  Say 'N' unless you want to really enforce this check.
24423aac3ebeSThomas Gleixner
2443b700e7f0SSeth Jenningssource "kernel/livepatch/Kconfig"
2444b700e7f0SSeth Jennings
2445506f1d07SSam Ravnborgendmenu
2446506f1d07SSam Ravnborg
24473072e413SMichal Hockoconfig ARCH_HAS_ADD_PAGES
24483072e413SMichal Hocko	def_bool y
24495c11f00bSDavid Hildenbrand	depends on ARCH_ENABLE_MEMORY_HOTPLUG
24503072e413SMichal Hocko
2451f91ef222SOscar Salvadorconfig ARCH_MHP_MEMMAP_ON_MEMORY_ENABLE
2452f91ef222SOscar Salvador	def_bool y
2453f91ef222SOscar Salvador
2454da85f865SBjorn Helgaasmenu "Power management and ACPI options"
2455e279b6c1SSam Ravnborg
2456e279b6c1SSam Ravnborgconfig ARCH_HIBERNATION_HEADER
24573c2362e6SHarvey Harrison	def_bool y
245844556530SZhimin Gu	depends on HIBERNATION
2459e279b6c1SSam Ravnborg
2460e279b6c1SSam Ravnborgsource "kernel/power/Kconfig"
2461e279b6c1SSam Ravnborg
2462e279b6c1SSam Ravnborgsource "drivers/acpi/Kconfig"
2463e279b6c1SSam Ravnborg
2464a6b68076SAndi Kleenconfig X86_APM_BOOT
24656fc108a0SJan Beulich	def_bool y
2466282e5aabSPaul Bolle	depends on APM
2467a6b68076SAndi Kleen
2468e279b6c1SSam Ravnborgmenuconfig APM
2469e279b6c1SSam Ravnborg	tristate "APM (Advanced Power Management) BIOS support"
2470efefa6f6SIngo Molnar	depends on X86_32 && PM_SLEEP
2471a7f7f624SMasahiro Yamada	help
2472e279b6c1SSam Ravnborg	  APM is a BIOS specification for saving power using several different
2473e279b6c1SSam Ravnborg	  techniques. This is mostly useful for battery powered laptops with
2474e279b6c1SSam Ravnborg	  APM compliant BIOSes. If you say Y here, the system time will be
2475e279b6c1SSam Ravnborg	  reset after a RESUME operation, the /proc/apm device will provide
2476e279b6c1SSam Ravnborg	  battery status information, and user-space programs will receive
2477e279b6c1SSam Ravnborg	  notification of APM "events" (e.g. battery status change).
2478e279b6c1SSam Ravnborg
2479e279b6c1SSam Ravnborg	  If you select "Y" here, you can disable actual use of the APM
2480e279b6c1SSam Ravnborg	  BIOS by passing the "apm=off" option to the kernel at boot time.
2481e279b6c1SSam Ravnborg
2482e279b6c1SSam Ravnborg	  Note that the APM support is almost completely disabled for
2483e279b6c1SSam Ravnborg	  machines with more than one CPU.
2484e279b6c1SSam Ravnborg
2485e279b6c1SSam Ravnborg	  In order to use APM, you will need supporting software. For location
2486151f4e2bSMauro Carvalho Chehab	  and more information, read <file:Documentation/power/apm-acpi.rst>
24872dc98fd3SMichael Witten	  and the Battery Powered Linux mini-HOWTO, available from
2488e279b6c1SSam Ravnborg	  <http://www.tldp.org/docs.html#howto>.
2489e279b6c1SSam Ravnborg
2490e279b6c1SSam Ravnborg	  This driver does not spin down disk drives (see the hdparm(8)
2491e279b6c1SSam Ravnborg	  manpage ("man 8 hdparm") for that), and it doesn't turn off
2492e279b6c1SSam Ravnborg	  VESA-compliant "green" monitors.
2493e279b6c1SSam Ravnborg
2494e279b6c1SSam Ravnborg	  This driver does not support the TI 4000M TravelMate and the ACER
2495e279b6c1SSam Ravnborg	  486/DX4/75 because they don't have compliant BIOSes. Many "green"
2496e279b6c1SSam Ravnborg	  desktop machines also don't have compliant BIOSes, and this driver
2497e279b6c1SSam Ravnborg	  may cause those machines to panic during the boot phase.
2498e279b6c1SSam Ravnborg
2499e279b6c1SSam Ravnborg	  Generally, if you don't have a battery in your machine, there isn't
2500e279b6c1SSam Ravnborg	  much point in using this driver and you should say N. If you get
2501e279b6c1SSam Ravnborg	  random kernel OOPSes or reboots that don't seem to be related to
2502e279b6c1SSam Ravnborg	  anything, try disabling/enabling this option (or disabling/enabling
2503e279b6c1SSam Ravnborg	  APM in your BIOS).
2504e279b6c1SSam Ravnborg
2505e279b6c1SSam Ravnborg	  Some other things you should try when experiencing seemingly random,
2506e279b6c1SSam Ravnborg	  "weird" problems:
2507e279b6c1SSam Ravnborg
2508e279b6c1SSam Ravnborg	  1) make sure that you have enough swap space and that it is
2509e279b6c1SSam Ravnborg	  enabled.
2510e279b6c1SSam Ravnborg	  2) pass the "no-hlt" option to the kernel
2511e279b6c1SSam Ravnborg	  3) switch on floating point emulation in the kernel and pass
2512e279b6c1SSam Ravnborg	  the "no387" option to the kernel
2513e279b6c1SSam Ravnborg	  4) pass the "floppy=nodma" option to the kernel
2514e279b6c1SSam Ravnborg	  5) pass the "mem=4M" option to the kernel (thereby disabling
2515e279b6c1SSam Ravnborg	  all but the first 4 MB of RAM)
2516e279b6c1SSam Ravnborg	  6) make sure that the CPU is not over clocked.
2517e279b6c1SSam Ravnborg	  7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/>
2518e279b6c1SSam Ravnborg	  8) disable the cache from your BIOS settings
2519e279b6c1SSam Ravnborg	  9) install a fan for the video card or exchange video RAM
2520e279b6c1SSam Ravnborg	  10) install a better fan for the CPU
2521e279b6c1SSam Ravnborg	  11) exchange RAM chips
2522e279b6c1SSam Ravnborg	  12) exchange the motherboard.
2523e279b6c1SSam Ravnborg
2524e279b6c1SSam Ravnborg	  To compile this driver as a module, choose M here: the
2525e279b6c1SSam Ravnborg	  module will be called apm.
2526e279b6c1SSam Ravnborg
2527e279b6c1SSam Ravnborgif APM
2528e279b6c1SSam Ravnborg
2529e279b6c1SSam Ravnborgconfig APM_IGNORE_USER_SUSPEND
2530e279b6c1SSam Ravnborg	bool "Ignore USER SUSPEND"
2531a7f7f624SMasahiro Yamada	help
2532e279b6c1SSam Ravnborg	  This option will ignore USER SUSPEND requests. On machines with a
2533e279b6c1SSam Ravnborg	  compliant APM BIOS, you want to say N. However, on the NEC Versa M
2534e279b6c1SSam Ravnborg	  series notebooks, it is necessary to say Y because of a BIOS bug.
2535e279b6c1SSam Ravnborg
2536e279b6c1SSam Ravnborgconfig APM_DO_ENABLE
2537e279b6c1SSam Ravnborg	bool "Enable PM at boot time"
2538a7f7f624SMasahiro Yamada	help
2539e279b6c1SSam Ravnborg	  Enable APM features at boot time. From page 36 of the APM BIOS
2540e279b6c1SSam Ravnborg	  specification: "When disabled, the APM BIOS does not automatically
2541e279b6c1SSam Ravnborg	  power manage devices, enter the Standby State, enter the Suspend
2542e279b6c1SSam Ravnborg	  State, or take power saving steps in response to CPU Idle calls."
2543e279b6c1SSam Ravnborg	  This driver will make CPU Idle calls when Linux is idle (unless this
2544e279b6c1SSam Ravnborg	  feature is turned off -- see "Do CPU IDLE calls", below). This
2545e279b6c1SSam Ravnborg	  should always save battery power, but more complicated APM features
2546e279b6c1SSam Ravnborg	  will be dependent on your BIOS implementation. You may need to turn
2547e279b6c1SSam Ravnborg	  this option off if your computer hangs at boot time when using APM
2548e279b6c1SSam Ravnborg	  support, or if it beeps continuously instead of suspending. Turn
2549e279b6c1SSam Ravnborg	  this off if you have a NEC UltraLite Versa 33/C or a Toshiba
2550e279b6c1SSam Ravnborg	  T400CDT. This is off by default since most machines do fine without
2551e279b6c1SSam Ravnborg	  this feature.
2552e279b6c1SSam Ravnborg
2553e279b6c1SSam Ravnborgconfig APM_CPU_IDLE
2554dd8af076SLen Brown	depends on CPU_IDLE
2555e279b6c1SSam Ravnborg	bool "Make CPU Idle calls when idle"
2556a7f7f624SMasahiro Yamada	help
2557e279b6c1SSam Ravnborg	  Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop.
2558e279b6c1SSam Ravnborg	  On some machines, this can activate improved power savings, such as
2559e279b6c1SSam Ravnborg	  a slowed CPU clock rate, when the machine is idle. These idle calls
2560e279b6c1SSam Ravnborg	  are made after the idle loop has run for some length of time (e.g.,
2561e279b6c1SSam Ravnborg	  333 mS). On some machines, this will cause a hang at boot time or
2562e279b6c1SSam Ravnborg	  whenever the CPU becomes idle. (On machines with more than one CPU,
2563e279b6c1SSam Ravnborg	  this option does nothing.)
2564e279b6c1SSam Ravnborg
2565e279b6c1SSam Ravnborgconfig APM_DISPLAY_BLANK
2566e279b6c1SSam Ravnborg	bool "Enable console blanking using APM"
2567a7f7f624SMasahiro Yamada	help
2568e279b6c1SSam Ravnborg	  Enable console blanking using the APM. Some laptops can use this to
2569e279b6c1SSam Ravnborg	  turn off the LCD backlight when the screen blanker of the Linux
2570e279b6c1SSam Ravnborg	  virtual console blanks the screen. Note that this is only used by
2571e279b6c1SSam Ravnborg	  the virtual console screen blanker, and won't turn off the backlight
2572e279b6c1SSam Ravnborg	  when using the X Window system. This also doesn't have anything to
2573e279b6c1SSam Ravnborg	  do with your VESA-compliant power-saving monitor. Further, this
2574e279b6c1SSam Ravnborg	  option doesn't work for all laptops -- it might not turn off your
2575e279b6c1SSam Ravnborg	  backlight at all, or it might print a lot of errors to the console,
2576e279b6c1SSam Ravnborg	  especially if you are using gpm.
2577e279b6c1SSam Ravnborg
2578e279b6c1SSam Ravnborgconfig APM_ALLOW_INTS
2579e279b6c1SSam Ravnborg	bool "Allow interrupts during APM BIOS calls"
2580a7f7f624SMasahiro Yamada	help
2581e279b6c1SSam Ravnborg	  Normally we disable external interrupts while we are making calls to
2582e279b6c1SSam Ravnborg	  the APM BIOS as a measure to lessen the effects of a badly behaving
2583e279b6c1SSam Ravnborg	  BIOS implementation.  The BIOS should reenable interrupts if it
2584e279b6c1SSam Ravnborg	  needs to.  Unfortunately, some BIOSes do not -- especially those in
2585e279b6c1SSam Ravnborg	  many of the newer IBM Thinkpads.  If you experience hangs when you
2586e279b6c1SSam Ravnborg	  suspend, try setting this to Y.  Otherwise, say N.
2587e279b6c1SSam Ravnborg
2588e279b6c1SSam Ravnborgendif # APM
2589e279b6c1SSam Ravnborg
2590bb0a56ecSDave Jonessource "drivers/cpufreq/Kconfig"
2591e279b6c1SSam Ravnborg
2592e279b6c1SSam Ravnborgsource "drivers/cpuidle/Kconfig"
2593e279b6c1SSam Ravnborg
259427471fdbSAndy Henroidsource "drivers/idle/Kconfig"
259527471fdbSAndy Henroid
2596e279b6c1SSam Ravnborgendmenu
2597e279b6c1SSam Ravnborg
2598e279b6c1SSam Ravnborg
2599e279b6c1SSam Ravnborgmenu "Bus options (PCI etc.)"
2600e279b6c1SSam Ravnborg
2601e279b6c1SSam Ravnborgchoice
2602e279b6c1SSam Ravnborg	prompt "PCI access mode"
2603efefa6f6SIngo Molnar	depends on X86_32 && PCI
2604e279b6c1SSam Ravnborg	default PCI_GOANY
2605a7f7f624SMasahiro Yamada	help
2606e279b6c1SSam Ravnborg	  On PCI systems, the BIOS can be used to detect the PCI devices and
2607e279b6c1SSam Ravnborg	  determine their configuration. However, some old PCI motherboards
2608e279b6c1SSam Ravnborg	  have BIOS bugs and may crash if this is done. Also, some embedded
2609e279b6c1SSam Ravnborg	  PCI-based systems don't have any BIOS at all. Linux can also try to
2610e279b6c1SSam Ravnborg	  detect the PCI hardware directly without using the BIOS.
2611e279b6c1SSam Ravnborg
2612e279b6c1SSam Ravnborg	  With this option, you can specify how Linux should detect the
2613e279b6c1SSam Ravnborg	  PCI devices. If you choose "BIOS", the BIOS will be used,
2614e279b6c1SSam Ravnborg	  if you choose "Direct", the BIOS won't be used, and if you
2615e279b6c1SSam Ravnborg	  choose "MMConfig", then PCI Express MMCONFIG will be used.
2616e279b6c1SSam Ravnborg	  If you choose "Any", the kernel will try MMCONFIG, then the
2617e279b6c1SSam Ravnborg	  direct access method and falls back to the BIOS if that doesn't
2618e279b6c1SSam Ravnborg	  work. If unsure, go with the default, which is "Any".
2619e279b6c1SSam Ravnborg
2620e279b6c1SSam Ravnborgconfig PCI_GOBIOS
2621e279b6c1SSam Ravnborg	bool "BIOS"
2622e279b6c1SSam Ravnborg
2623e279b6c1SSam Ravnborgconfig PCI_GOMMCONFIG
2624e279b6c1SSam Ravnborg	bool "MMConfig"
2625e279b6c1SSam Ravnborg
2626e279b6c1SSam Ravnborgconfig PCI_GODIRECT
2627e279b6c1SSam Ravnborg	bool "Direct"
2628e279b6c1SSam Ravnborg
26293ef0e1f8SAndres Salomonconfig PCI_GOOLPC
263076fb6570SDaniel Drake	bool "OLPC XO-1"
26313ef0e1f8SAndres Salomon	depends on OLPC
26323ef0e1f8SAndres Salomon
26332bdd1b03SAndres Salomonconfig PCI_GOANY
26342bdd1b03SAndres Salomon	bool "Any"
26352bdd1b03SAndres Salomon
2636e279b6c1SSam Ravnborgendchoice
2637e279b6c1SSam Ravnborg
2638e279b6c1SSam Ravnborgconfig PCI_BIOS
26393c2362e6SHarvey Harrison	def_bool y
2640efefa6f6SIngo Molnar	depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY)
2641e279b6c1SSam Ravnborg
2642e279b6c1SSam Ravnborg# x86-64 doesn't support PCI BIOS access from long mode so always go direct.
2643e279b6c1SSam Ravnborgconfig PCI_DIRECT
26443c2362e6SHarvey Harrison	def_bool y
26450aba496fSShaohua Li	depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC || PCI_GOMMCONFIG))
2646e279b6c1SSam Ravnborg
2647e279b6c1SSam Ravnborgconfig PCI_MMCONFIG
2648b45c9f36SJan Kiszka	bool "Support mmconfig PCI config space access" if X86_64
2649b45c9f36SJan Kiszka	default y
26504590d98fSAndy Shevchenko	depends on PCI && (ACPI || JAILHOUSE_GUEST)
2651b45c9f36SJan Kiszka	depends on X86_64 || (PCI_GOANY || PCI_GOMMCONFIG)
2652e279b6c1SSam Ravnborg
26533ef0e1f8SAndres Salomonconfig PCI_OLPC
26542bdd1b03SAndres Salomon	def_bool y
26552bdd1b03SAndres Salomon	depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY)
26563ef0e1f8SAndres Salomon
2657b5401a96SAlex Nixonconfig PCI_XEN
2658b5401a96SAlex Nixon	def_bool y
2659b5401a96SAlex Nixon	depends on PCI && XEN
2660b5401a96SAlex Nixon
26618364e1f8SJan Kiszkaconfig MMCONF_FAM10H
26628364e1f8SJan Kiszka	def_bool y
26638364e1f8SJan Kiszka	depends on X86_64 && PCI_MMCONFIG && ACPI
2664e279b6c1SSam Ravnborg
26653f6ea84aSIra W. Snyderconfig PCI_CNB20LE_QUIRK
26666a108a14SDavid Rientjes	bool "Read CNB20LE Host Bridge Windows" if EXPERT
26676ea30386SKees Cook	depends on PCI
26683f6ea84aSIra W. Snyder	help
26693f6ea84aSIra W. Snyder	  Read the PCI windows out of the CNB20LE host bridge. This allows
26703f6ea84aSIra W. Snyder	  PCI hotplug to work on systems with the CNB20LE chipset which do
26713f6ea84aSIra W. Snyder	  not have ACPI.
26723f6ea84aSIra W. Snyder
267364a5fed6SBjorn Helgaas	  There's no public spec for this chipset, and this functionality
267464a5fed6SBjorn Helgaas	  is known to be incomplete.
267564a5fed6SBjorn Helgaas
267664a5fed6SBjorn Helgaas	  You should say N unless you know you need this.
267764a5fed6SBjorn Helgaas
26783a495511SWilliam Breathitt Grayconfig ISA_BUS
267917a2a129SWilliam Breathitt Gray	bool "ISA bus support on modern systems" if EXPERT
26803a495511SWilliam Breathitt Gray	help
268117a2a129SWilliam Breathitt Gray	  Expose ISA bus device drivers and options available for selection and
268217a2a129SWilliam Breathitt Gray	  configuration. Enable this option if your target machine has an ISA
268317a2a129SWilliam Breathitt Gray	  bus. ISA is an older system, displaced by PCI and newer bus
268417a2a129SWilliam Breathitt Gray	  architectures -- if your target machine is modern, it probably does
268517a2a129SWilliam Breathitt Gray	  not have an ISA bus.
26863a495511SWilliam Breathitt Gray
26873a495511SWilliam Breathitt Gray	  If unsure, say N.
26883a495511SWilliam Breathitt Gray
26891c00f016SDavid Rientjes# x86_64 have no ISA slots, but can have ISA-style DMA.
2690e279b6c1SSam Ravnborgconfig ISA_DMA_API
26911c00f016SDavid Rientjes	bool "ISA-style DMA support" if (X86_64 && EXPERT)
26921c00f016SDavid Rientjes	default y
26931c00f016SDavid Rientjes	help
26941c00f016SDavid Rientjes	  Enables ISA-style DMA support for devices requiring such controllers.
26951c00f016SDavid Rientjes	  If unsure, say Y.
2696e279b6c1SSam Ravnborg
269751e68d05SLinus Torvaldsif X86_32
269851e68d05SLinus Torvalds
2699e279b6c1SSam Ravnborgconfig ISA
2700e279b6c1SSam Ravnborg	bool "ISA support"
2701a7f7f624SMasahiro Yamada	help
2702e279b6c1SSam Ravnborg	  Find out whether you have ISA slots on your motherboard.  ISA is the
2703e279b6c1SSam Ravnborg	  name of a bus system, i.e. the way the CPU talks to the other stuff
2704e279b6c1SSam Ravnborg	  inside your box.  Other bus systems are PCI, EISA, MicroChannel
2705e279b6c1SSam Ravnborg	  (MCA) or VESA.  ISA is an older system, now being displaced by PCI;
2706e279b6c1SSam Ravnborg	  newer boards don't support it.  If you have ISA, say Y, otherwise N.
2707e279b6c1SSam Ravnborg
2708e279b6c1SSam Ravnborgconfig SCx200
2709e279b6c1SSam Ravnborg	tristate "NatSemi SCx200 support"
2710a7f7f624SMasahiro Yamada	help
2711e279b6c1SSam Ravnborg	  This provides basic support for National Semiconductor's
2712e279b6c1SSam Ravnborg	  (now AMD's) Geode processors.  The driver probes for the
2713e279b6c1SSam Ravnborg	  PCI-IDs of several on-chip devices, so its a good dependency
2714e279b6c1SSam Ravnborg	  for other scx200_* drivers.
2715e279b6c1SSam Ravnborg
2716e279b6c1SSam Ravnborg	  If compiled as a module, the driver is named scx200.
2717e279b6c1SSam Ravnborg
2718e279b6c1SSam Ravnborgconfig SCx200HR_TIMER
2719e279b6c1SSam Ravnborg	tristate "NatSemi SCx200 27MHz High-Resolution Timer Support"
2720592913ecSJohn Stultz	depends on SCx200
2721e279b6c1SSam Ravnborg	default y
2722a7f7f624SMasahiro Yamada	help
2723e279b6c1SSam Ravnborg	  This driver provides a clocksource built upon the on-chip
2724e279b6c1SSam Ravnborg	  27MHz high-resolution timer.  Its also a workaround for
2725e279b6c1SSam Ravnborg	  NSC Geode SC-1100's buggy TSC, which loses time when the
2726e279b6c1SSam Ravnborg	  processor goes idle (as is done by the scheduler).  The
2727e279b6c1SSam Ravnborg	  other workaround is idle=poll boot option.
2728e279b6c1SSam Ravnborg
27293ef0e1f8SAndres Salomonconfig OLPC
27303ef0e1f8SAndres Salomon	bool "One Laptop Per Child support"
273154008979SThomas Gleixner	depends on !X86_PAE
27323c554946SAndres Salomon	select GPIOLIB
2733dc3119e7SThomas Gleixner	select OF
273445bb1674SDaniel Drake	select OF_PROMTREE
2735b4e51854SGrant Likely	select IRQ_DOMAIN
27360c3d931bSLubomir Rintel	select OLPC_EC
2737a7f7f624SMasahiro Yamada	help
27383ef0e1f8SAndres Salomon	  Add support for detecting the unique features of the OLPC
27393ef0e1f8SAndres Salomon	  XO hardware.
27403ef0e1f8SAndres Salomon
2741a3128588SDaniel Drakeconfig OLPC_XO1_PM
2742a3128588SDaniel Drake	bool "OLPC XO-1 Power Management"
2743fa112cf1SBorislav Petkov	depends on OLPC && MFD_CS5535=y && PM_SLEEP
2744a7f7f624SMasahiro Yamada	help
274597c4cb71SDaniel Drake	  Add support for poweroff and suspend of the OLPC XO-1 laptop.
2746bf1ebf00SDaniel Drake
2747cfee9597SDaniel Drakeconfig OLPC_XO1_RTC
2748cfee9597SDaniel Drake	bool "OLPC XO-1 Real Time Clock"
2749cfee9597SDaniel Drake	depends on OLPC_XO1_PM && RTC_DRV_CMOS
2750a7f7f624SMasahiro Yamada	help
2751cfee9597SDaniel Drake	  Add support for the XO-1 real time clock, which can be used as a
2752cfee9597SDaniel Drake	  programmable wakeup source.
2753cfee9597SDaniel Drake
27547feda8e9SDaniel Drakeconfig OLPC_XO1_SCI
27557feda8e9SDaniel Drake	bool "OLPC XO-1 SCI extras"
275692e830f2SArnd Bergmann	depends on OLPC && OLPC_XO1_PM && GPIO_CS5535=y
2757ed8e47feSRandy Dunlap	depends on INPUT=y
2758d8d01a63SDaniel Drake	select POWER_SUPPLY
2759a7f7f624SMasahiro Yamada	help
27607feda8e9SDaniel Drake	  Add support for SCI-based features of the OLPC XO-1 laptop:
27617bc74b3dSDaniel Drake	   - EC-driven system wakeups
27627feda8e9SDaniel Drake	   - Power button
27637bc74b3dSDaniel Drake	   - Ebook switch
27642cf2baeaSDaniel Drake	   - Lid switch
2765e1040ac6SDaniel Drake	   - AC adapter status updates
2766e1040ac6SDaniel Drake	   - Battery status updates
27677feda8e9SDaniel Drake
2768a0f30f59SDaniel Drakeconfig OLPC_XO15_SCI
2769a0f30f59SDaniel Drake	bool "OLPC XO-1.5 SCI extras"
2770d8d01a63SDaniel Drake	depends on OLPC && ACPI
2771d8d01a63SDaniel Drake	select POWER_SUPPLY
2772a7f7f624SMasahiro Yamada	help
2773a0f30f59SDaniel Drake	  Add support for SCI-based features of the OLPC XO-1.5 laptop:
2774a0f30f59SDaniel Drake	   - EC-driven system wakeups
2775a0f30f59SDaniel Drake	   - AC adapter status updates
2776a0f30f59SDaniel Drake	   - Battery status updates
2777e279b6c1SSam Ravnborg
2778d4f3e350SEd Wildgooseconfig ALIX
2779d4f3e350SEd Wildgoose	bool "PCEngines ALIX System Support (LED setup)"
2780d4f3e350SEd Wildgoose	select GPIOLIB
2781a7f7f624SMasahiro Yamada	help
2782d4f3e350SEd Wildgoose	  This option enables system support for the PCEngines ALIX.
2783d4f3e350SEd Wildgoose	  At present this just sets up LEDs for GPIO control on
2784d4f3e350SEd Wildgoose	  ALIX2/3/6 boards.  However, other system specific setup should
2785d4f3e350SEd Wildgoose	  get added here.
2786d4f3e350SEd Wildgoose
2787d4f3e350SEd Wildgoose	  Note: You must still enable the drivers for GPIO and LED support
2788d4f3e350SEd Wildgoose	  (GPIO_CS5535 & LEDS_GPIO) to actually use the LEDs
2789d4f3e350SEd Wildgoose
2790d4f3e350SEd Wildgoose	  Note: You have to set alix.force=1 for boards with Award BIOS.
2791d4f3e350SEd Wildgoose
2792da4e3302SPhilip Prindevilleconfig NET5501
2793da4e3302SPhilip Prindeville	bool "Soekris Engineering net5501 System Support (LEDS, GPIO, etc)"
2794da4e3302SPhilip Prindeville	select GPIOLIB
2795a7f7f624SMasahiro Yamada	help
2796da4e3302SPhilip Prindeville	  This option enables system support for the Soekris Engineering net5501.
2797da4e3302SPhilip Prindeville
27983197059aSPhilip A. Prindevilleconfig GEOS
27993197059aSPhilip A. Prindeville	bool "Traverse Technologies GEOS System Support (LEDS, GPIO, etc)"
28003197059aSPhilip A. Prindeville	select GPIOLIB
28013197059aSPhilip A. Prindeville	depends on DMI
2802a7f7f624SMasahiro Yamada	help
28033197059aSPhilip A. Prindeville	  This option enables system support for the Traverse Technologies GEOS.
28043197059aSPhilip A. Prindeville
28057d029125SVivien Didelotconfig TS5500
28067d029125SVivien Didelot	bool "Technologic Systems TS-5500 platform support"
28077d029125SVivien Didelot	depends on MELAN
28087d029125SVivien Didelot	select CHECK_SIGNATURE
28097d029125SVivien Didelot	select NEW_LEDS
28107d029125SVivien Didelot	select LEDS_CLASS
2811a7f7f624SMasahiro Yamada	help
28127d029125SVivien Didelot	  This option enables system support for the Technologic Systems TS-5500.
28137d029125SVivien Didelot
2814e279b6c1SSam Ravnborgendif # X86_32
2815e279b6c1SSam Ravnborg
281623ac4ae8SAndreas Herrmannconfig AMD_NB
2817e279b6c1SSam Ravnborg	def_bool y
28180e152cd7SBorislav Petkov	depends on CPU_SUP_AMD && PCI
2819e279b6c1SSam Ravnborg
2820e279b6c1SSam Ravnborgendmenu
2821e279b6c1SSam Ravnborg
2822e279b6c1SSam Ravnborg
28231572497cSChristoph Hellwigmenu "Binary Emulations"
2824e279b6c1SSam Ravnborg
2825e279b6c1SSam Ravnborgconfig IA32_EMULATION
2826e279b6c1SSam Ravnborg	bool "IA32 Emulation"
2827e279b6c1SSam Ravnborg	depends on X86_64
282839f88911SIngo Molnar	select ARCH_WANT_OLD_COMPAT_IPC
2829d1603990SRandy Dunlap	select BINFMT_ELF
283039f88911SIngo Molnar	select COMPAT_OLD_SIGACTION
2831a7f7f624SMasahiro Yamada	help
28325fd92e65SH. J. Lu	  Include code to run legacy 32-bit programs under a
28335fd92e65SH. J. Lu	  64-bit kernel. You should likely turn this on, unless you're
28345fd92e65SH. J. Lu	  100% sure that you don't have any 32-bit programs left.
2835e279b6c1SSam Ravnborg
2836e279b6c1SSam Ravnborgconfig IA32_AOUT
2837e279b6c1SSam Ravnborg	tristate "IA32 a.out support"
28386b213e1bSDavid Woodhouse	depends on IA32_EMULATION
2839eac61655SBorislav Petkov	depends on BROKEN
2840a7f7f624SMasahiro Yamada	help
2841e279b6c1SSam Ravnborg	  Support old a.out binaries in the 32bit emulation.
2842e279b6c1SSam Ravnborg
28430bf62763SH. Peter Anvinconfig X86_X32
28446ea30386SKees Cook	bool "x32 ABI for 64-bit mode"
28459b54050bSBrian Gerst	depends on X86_64
2846a7f7f624SMasahiro Yamada	help
28475fd92e65SH. J. Lu	  Include code to run binaries for the x32 native 32-bit ABI
28485fd92e65SH. J. Lu	  for 64-bit processors.  An x32 process gets access to the
28495fd92e65SH. J. Lu	  full 64-bit register file and wide data path while leaving
28505fd92e65SH. J. Lu	  pointers at 32 bits for smaller memory footprint.
28515fd92e65SH. J. Lu
28525fd92e65SH. J. Lu	  You will need a recent binutils (2.22 or later) with
28535fd92e65SH. J. Lu	  elf32_x86_64 support enabled to compile a kernel with this
28545fd92e65SH. J. Lu	  option set.
28555fd92e65SH. J. Lu
2856953fee1dSIngo Molnarconfig COMPAT_32
2857953fee1dSIngo Molnar	def_bool y
2858953fee1dSIngo Molnar	depends on IA32_EMULATION || X86_32
2859953fee1dSIngo Molnar	select HAVE_UID16
2860953fee1dSIngo Molnar	select OLD_SIGSUSPEND3
2861953fee1dSIngo Molnar
2862e279b6c1SSam Ravnborgconfig COMPAT
28633c2362e6SHarvey Harrison	def_bool y
28640bf62763SH. Peter Anvin	depends on IA32_EMULATION || X86_X32
2865e279b6c1SSam Ravnborg
28663120e25eSJan Beulichif COMPAT
2867e279b6c1SSam Ravnborgconfig COMPAT_FOR_U64_ALIGNMENT
28683120e25eSJan Beulich	def_bool y
2869e279b6c1SSam Ravnborg
2870e279b6c1SSam Ravnborgconfig SYSVIPC_COMPAT
28713c2362e6SHarvey Harrison	def_bool y
28723120e25eSJan Beulich	depends on SYSVIPC
28733120e25eSJan Beulichendif
2874ee009e4aSDavid Howells
2875e279b6c1SSam Ravnborgendmenu
2876e279b6c1SSam Ravnborg
2877e279b6c1SSam Ravnborg
2878e5beae16SKeith Packardconfig HAVE_ATOMIC_IOMAP
2879e5beae16SKeith Packard	def_bool y
2880e5beae16SKeith Packard	depends on X86_32
2881e5beae16SKeith Packard
2882edf88417SAvi Kivitysource "arch/x86/kvm/Kconfig"
28835e8ebd84SJason A. Donenfeld
28845e8ebd84SJason A. Donenfeldsource "arch/x86/Kconfig.assembler"
2885