xref: /linux/arch/x86/Kconfig (revision 47010c040dec8af6347ec6259104fc13f7e7e30a)
1b2441318SGreg Kroah-Hartman# SPDX-License-Identifier: GPL-2.0
2daa93fabSSam Ravnborg# Select 32 or 64 bit
3daa93fabSSam Ravnborgconfig 64BIT
4104daea1SMasahiro Yamada	bool "64-bit kernel" if "$(ARCH)" = "x86"
5104daea1SMasahiro Yamada	default "$(ARCH)" != "i386"
6a7f7f624SMasahiro Yamada	help
7daa93fabSSam Ravnborg	  Say yes to build a 64-bit kernel - formerly known as x86_64
8daa93fabSSam Ravnborg	  Say no to build a 32-bit kernel - formerly known as i386
9daa93fabSSam Ravnborg
10daa93fabSSam Ravnborgconfig X86_32
113120e25eSJan Beulich	def_bool y
123120e25eSJan Beulich	depends on !64BIT
13341c787eSIngo Molnar	# Options that are inherently 32-bit kernel only:
14341c787eSIngo Molnar	select ARCH_WANT_IPC_PARSE_VERSION
15341c787eSIngo Molnar	select CLKSRC_I8253
16341c787eSIngo Molnar	select CLONE_BACKWARDS
17157e118bSThomas Gleixner	select GENERIC_VDSO_32
18117ed454SThomas Gleixner	select HAVE_DEBUG_STACKOVERFLOW
19157e118bSThomas Gleixner	select KMAP_LOCAL
20341c787eSIngo Molnar	select MODULES_USE_ELF_REL
21341c787eSIngo Molnar	select OLD_SIGACTION
222ca408d9SBrian Gerst	select ARCH_SPLIT_ARG64
23daa93fabSSam Ravnborg
24daa93fabSSam Ravnborgconfig X86_64
253120e25eSJan Beulich	def_bool y
263120e25eSJan Beulich	depends on 64BIT
27d94e0685SIngo Molnar	# Options that are inherently 64-bit kernel only:
284eb0716eSAlexandre Ghiti	select ARCH_HAS_GIGANTIC_PAGE
29c12d3362SArd Biesheuvel	select ARCH_SUPPORTS_INT128 if CC_HAS_INT128
30d94e0685SIngo Molnar	select ARCH_USE_CMPXCHG_LOCKREF
31d94e0685SIngo Molnar	select HAVE_ARCH_SOFT_DIRTY
32d94e0685SIngo Molnar	select MODULES_USE_ELF_RELA
33f616ab59SChristoph Hellwig	select NEED_DMA_MAP_STATE
3409230cbcSChristoph Hellwig	select SWIOTLB
357facdc42SAl Viro	select ARCH_HAS_ELFCORE_COMPAT
3663703f37SKefeng Wang	select ZONE_DMA32
371032c0baSSam Ravnborg
38518049d9SSteven Rostedt (VMware)config FORCE_DYNAMIC_FTRACE
39518049d9SSteven Rostedt (VMware)	def_bool y
40518049d9SSteven Rostedt (VMware)	depends on X86_32
41518049d9SSteven Rostedt (VMware)	depends on FUNCTION_TRACER
42518049d9SSteven Rostedt (VMware)	select DYNAMIC_FTRACE
43518049d9SSteven Rostedt (VMware)	help
44518049d9SSteven Rostedt (VMware)	 We keep the static function tracing (!DYNAMIC_FTRACE) around
45518049d9SSteven Rostedt (VMware)	 in order to test the non static function tracing in the
46518049d9SSteven Rostedt (VMware)	 generic code, as other architectures still use it. But we
47518049d9SSteven Rostedt (VMware)	 only need to keep it around for x86_64. No need to keep it
48518049d9SSteven Rostedt (VMware)	 for x86_32. For x86_32, force DYNAMIC_FTRACE.
49d94e0685SIngo Molnar#
50d94e0685SIngo Molnar# Arch settings
51d94e0685SIngo Molnar#
52d94e0685SIngo Molnar# ( Note that options that are marked 'if X86_64' could in principle be
53d94e0685SIngo Molnar#   ported to 32-bit as well. )
54d94e0685SIngo Molnar#
558d5fffb9SSam Ravnborgconfig X86
563c2362e6SHarvey Harrison	def_bool y
57c763ea26SIngo Molnar	#
58c763ea26SIngo Molnar	# Note: keep this list sorted alphabetically
59c763ea26SIngo Molnar	#
606471b825SIngo Molnar	select ACPI_LEGACY_TABLES_LOOKUP	if ACPI
616e0a0ea1SGraeme Gregory	select ACPI_SYSTEM_POWER_STATES_SUPPORT	if ACPI
62942fa985SYury Norov	select ARCH_32BIT_OFF_T			if X86_32
632a21ad57SThomas Gleixner	select ARCH_CLOCKSOURCE_INIT
641f6d3a8fSMasami Hiramatsu	select ARCH_CORRECT_STACKTRACE_ON_KRETPROBE
651e866974SAnshuman Khandual	select ARCH_ENABLE_HUGEPAGE_MIGRATION if X86_64 && HUGETLB_PAGE && MIGRATION
665c11f00bSDavid Hildenbrand	select ARCH_ENABLE_MEMORY_HOTPLUG if X86_64
6791024b3cSAnshuman Khandual	select ARCH_ENABLE_MEMORY_HOTREMOVE if MEMORY_HOTPLUG
68cebc774fSAnshuman Khandual	select ARCH_ENABLE_SPLIT_PMD_PTLOCK if (PGTABLE_LEVELS > 2) && (X86_64 || X86_PAE)
691e866974SAnshuman Khandual	select ARCH_ENABLE_THP_MIGRATION if X86_64 && TRANSPARENT_HUGEPAGE
7091dda51aSAleksey Makarov	select ARCH_HAS_ACPI_TABLE_UPGRADE	if ACPI
71c2280be8SAnshuman Khandual	select ARCH_HAS_CACHE_LINE_SIZE
722792d84eSKees Cook	select ARCH_HAS_CURRENT_STACK_POINTER
73fa5b6ec9SLaura Abbott	select ARCH_HAS_DEBUG_VIRTUAL
74399145f9SAnshuman Khandual	select ARCH_HAS_DEBUG_VM_PGTABLE	if !X86_PAE
7521266be9SDan Williams	select ARCH_HAS_DEVMEM_IS_ALLOWED
76b1a57bbfSDouglas Anderson	select ARCH_HAS_EARLY_DEBUG		if KGDB
776471b825SIngo Molnar	select ARCH_HAS_ELF_RANDOMIZE
7872d93104SLinus Torvalds	select ARCH_HAS_FAST_MULTIPLIER
796974f0c4SDaniel Micay	select ARCH_HAS_FORTIFY_SOURCE
80957e3facSRiku Voipio	select ARCH_HAS_GCOV_PROFILE_ALL
81bece04b5SMarco Elver	select ARCH_HAS_KCOV			if X86_64
820c9c1d56SThiago Jung Bauermann	select ARCH_HAS_MEM_ENCRYPT
8310bcc80eSMathieu Desnoyers	select ARCH_HAS_MEMBARRIER_SYNC_CORE
840ebeea8cSDaniel Borkmann	select ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE
85c763ea26SIngo Molnar	select ARCH_HAS_PMEM_API		if X86_64
8617596731SRobin Murphy	select ARCH_HAS_PTE_DEVMAP		if X86_64
873010a5eaSLaurent Dufour	select ARCH_HAS_PTE_SPECIAL
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
97e10cd4b0SChristoph Hellwig	select ARCH_HAS_VM_GET_PAGE_PROT
987e01ccb4SZong Li	select ARCH_HAS_DEBUG_WX
9963703f37SKefeng Wang	select ARCH_HAS_ZONE_DMA_SET if EXPERT
1006471b825SIngo Molnar	select ARCH_HAVE_NMI_SAFE_CMPXCHG
1016471b825SIngo Molnar	select ARCH_MIGHT_HAVE_ACPI_PDC		if ACPI
10277fbbc81SMark Salter	select ARCH_MIGHT_HAVE_PC_PARPORT
1035e2c18c0SMark Salter	select ARCH_MIGHT_HAVE_PC_SERIO
1043599fe12SThomas Gleixner	select ARCH_STACKWALK
1052c870e61SArnd Bergmann	select ARCH_SUPPORTS_ACPI
1066471b825SIngo Molnar	select ARCH_SUPPORTS_ATOMIC_RMW
1075d6ad668SMike Rapoport	select ARCH_SUPPORTS_DEBUG_PAGEALLOC
108d283d422SPasha Tatashin	select ARCH_SUPPORTS_PAGE_TABLE_CHECK	if X86_64
1096471b825SIngo Molnar	select ARCH_SUPPORTS_NUMA_BALANCING	if X86_64
11014df3267SThomas Gleixner	select ARCH_SUPPORTS_KMAP_LOCAL_FORCE_MAP	if NR_CPUS <= 4096
111583bfd48SNathan Chancellor	select ARCH_SUPPORTS_LTO_CLANG
112583bfd48SNathan Chancellor	select ARCH_SUPPORTS_LTO_CLANG_THIN
1136471b825SIngo Molnar	select ARCH_USE_BUILTIN_BSWAP
114dce44566SAnshuman Khandual	select ARCH_USE_MEMTEST
1156471b825SIngo Molnar	select ARCH_USE_QUEUED_RWLOCKS
1166471b825SIngo Molnar	select ARCH_USE_QUEUED_SPINLOCKS
1172ce0d7f9SMark Brown	select ARCH_USE_SYM_ANNOTATIONS
118ce4a4e56SAndy Lutomirski	select ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH
11981c22041SDaniel Borkmann	select ARCH_WANT_DEFAULT_BPF_JIT	if X86_64
120c763ea26SIngo Molnar	select ARCH_WANTS_DYNAMIC_TASK_STRUCT
12151c2ee6dSNick Desaulniers	select ARCH_WANTS_NO_INSTR
12207431506SAnshuman Khandual	select ARCH_WANT_GENERAL_HUGETLB
1233876d4a3SAlexandre Ghiti	select ARCH_WANT_HUGE_PMD_SHARE
124*47010c04SMuchun Song	select ARCH_WANT_HUGETLB_PAGE_OPTIMIZE_VMEMMAP	if X86_64
12559612b24SNathan Chancellor	select ARCH_WANT_LD_ORPHAN_WARN
12638d8b4e6SHuang Ying	select ARCH_WANTS_THP_SWAP		if X86_64
127b5f06f64SBalbir Singh	select ARCH_HAS_PARANOID_L1D_FLUSH
12810916706SShile Zhang	select BUILDTIME_TABLE_SORT
1296471b825SIngo Molnar	select CLKEVT_I8253
1306471b825SIngo Molnar	select CLOCKSOURCE_VALIDATE_LAST_CYCLE
1316471b825SIngo Molnar	select CLOCKSOURCE_WATCHDOG
1326471b825SIngo Molnar	select DCACHE_WORD_ACCESS
1333aac3ebeSThomas Gleixner	select DYNAMIC_SIGFRAME
13445471cd9SLinus Torvalds	select EDAC_ATOMIC_SCRUB
13545471cd9SLinus Torvalds	select EDAC_SUPPORT
1366471b825SIngo Molnar	select GENERIC_CLOCKEVENTS_BROADCAST	if X86_64 || (X86_32 && X86_LOCAL_APIC)
1376471b825SIngo Molnar	select GENERIC_CLOCKEVENTS_MIN_ADJUST
1386471b825SIngo Molnar	select GENERIC_CMOS_UPDATE
1396471b825SIngo Molnar	select GENERIC_CPU_AUTOPROBE
14061dc0f55SThomas Gleixner	select GENERIC_CPU_VULNERABILITIES
1416471b825SIngo Molnar	select GENERIC_EARLY_IOREMAP
14227d6b4d1SThomas Gleixner	select GENERIC_ENTRY
1436471b825SIngo Molnar	select GENERIC_IOMAP
144c7d6c9ddSThomas Gleixner	select GENERIC_IRQ_EFFECTIVE_AFF_MASK	if SMP
1450fa115daSThomas Gleixner	select GENERIC_IRQ_MATRIX_ALLOCATOR	if X86_LOCAL_APIC
146ad7a929fSThomas Gleixner	select GENERIC_IRQ_MIGRATION		if SMP
1476471b825SIngo Molnar	select GENERIC_IRQ_PROBE
148c201c917SThomas Gleixner	select GENERIC_IRQ_RESERVATION_MODE
1496471b825SIngo Molnar	select GENERIC_IRQ_SHOW
1506471b825SIngo Molnar	select GENERIC_PENDING_IRQ		if SMP
1512ae27137SSteven Price	select GENERIC_PTDUMP
1526471b825SIngo Molnar	select GENERIC_SMP_IDLE_THREAD
1536471b825SIngo Molnar	select GENERIC_TIME_VSYSCALL
1547ac87074SVincenzo Frascino	select GENERIC_GETTIMEOFDAY
155550a77a7SDmitry Safonov	select GENERIC_VDSO_TIME_NS
15639656e83SChristoph Hellwig	select GUP_GET_PTE_LOW_HIGH		if X86_PAE
15717e5888eSHans de Goede	select HARDIRQS_SW_RESEND
1587edaeb68SThomas Gleixner	select HARDLOCKUP_CHECK_TIMESTAMP	if X86_64
1596471b825SIngo Molnar	select HAVE_ACPI_APEI			if ACPI
1606471b825SIngo Molnar	select HAVE_ACPI_APEI_NMI		if ACPI
1616471b825SIngo Molnar	select HAVE_ALIGNED_STRUCT_PAGE		if SLUB
1626471b825SIngo Molnar	select HAVE_ARCH_AUDITSYSCALL
1636471b825SIngo Molnar	select HAVE_ARCH_HUGE_VMAP		if X86_64 || X86_PAE
164eed1fceeSSong Liu	select HAVE_ARCH_HUGE_VMALLOC		if X86_64
1656471b825SIngo Molnar	select HAVE_ARCH_JUMP_LABEL
166b34006c4SArd Biesheuvel	select HAVE_ARCH_JUMP_LABEL_RELATIVE
167d17a1d97SAndrey Ryabinin	select HAVE_ARCH_KASAN			if X86_64
1680609ae01SDaniel Axtens	select HAVE_ARCH_KASAN_VMALLOC		if X86_64
1691dc0da6eSAlexander Potapenko	select HAVE_ARCH_KFENCE
1706471b825SIngo Molnar	select HAVE_ARCH_KGDB
1719e08f57dSDaniel Cashman	select HAVE_ARCH_MMAP_RND_BITS		if MMU
1729e08f57dSDaniel Cashman	select HAVE_ARCH_MMAP_RND_COMPAT_BITS	if MMU && COMPAT
1731b028f78SDmitry Safonov	select HAVE_ARCH_COMPAT_MMAP_BASES	if MMU && COMPAT
174271ca788SArd Biesheuvel	select HAVE_ARCH_PREL32_RELOCATIONS
1756471b825SIngo Molnar	select HAVE_ARCH_SECCOMP_FILTER
176f7d83c1cSKees Cook	select HAVE_ARCH_THREAD_STRUCT_WHITELIST
177afaef01cSAlexander Popov	select HAVE_ARCH_STACKLEAK
1786471b825SIngo Molnar	select HAVE_ARCH_TRACEHOOK
1796471b825SIngo Molnar	select HAVE_ARCH_TRANSPARENT_HUGEPAGE
180a00cc7d9SMatthew Wilcox	select HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD if X86_64
181b64d8d1eSPeter Xu	select HAVE_ARCH_USERFAULTFD_WP         if X86_64 && USERFAULTFD
1827677f7fdSAxel Rasmussen	select HAVE_ARCH_USERFAULTFD_MINOR	if X86_64 && USERFAULTFD
183e37e43a4SAndy Lutomirski	select HAVE_ARCH_VMAP_STACK		if X86_64
184fe950f60SKees Cook	select HAVE_ARCH_RANDOMIZE_KSTACK_OFFSET
185c763ea26SIngo Molnar	select HAVE_ARCH_WITHIN_STACK_FRAMES
1862ff2b7ecSMasahiro Yamada	select HAVE_ASM_MODVERSIONS
1876471b825SIngo Molnar	select HAVE_CMPXCHG_DOUBLE
1886471b825SIngo Molnar	select HAVE_CMPXCHG_LOCAL
1896471b825SIngo Molnar	select HAVE_CONTEXT_TRACKING		if X86_64
190d1f250e2SFrederic Weisbecker	select HAVE_CONTEXT_TRACKING_OFFSTACK	if HAVE_CONTEXT_TRACKING
1916471b825SIngo Molnar	select HAVE_C_RECORDMCOUNT
1926dafca97SSami Tolvanen	select HAVE_OBJTOOL_MCOUNT		if STACK_VALIDATION
1934ed308c4SSteven Rostedt (Google)	select HAVE_BUILDTIME_MCOUNT_SORT
1946471b825SIngo Molnar	select HAVE_DEBUG_KMEMLEAK
1959c5a3621SAkinobu Mita	select HAVE_DMA_CONTIGUOUS
196677aa9f7SSteven Rostedt	select HAVE_DYNAMIC_FTRACE
19706aeaaeaSMasami Hiramatsu	select HAVE_DYNAMIC_FTRACE_WITH_REGS
19802a474caSSteven Rostedt (VMware)	select HAVE_DYNAMIC_FTRACE_WITH_ARGS	if X86_64
199562955feSSteven Rostedt (VMware)	select HAVE_DYNAMIC_FTRACE_WITH_DIRECT_CALLS
200c316eb44SHeiko Carstens	select HAVE_SAMPLE_FTRACE_DIRECT	if X86_64
201503e4510SHeiko Carstens	select HAVE_SAMPLE_FTRACE_DIRECT_MULTI	if X86_64
20203f5781bSWang YanQing	select HAVE_EBPF_JIT
20358340a07SJohannes Berg	select HAVE_EFFICIENT_UNALIGNED_ACCESS
2046630a8e5SChristoph Hellwig	select HAVE_EISA
2055f56a5dfSJiri Slaby	select HAVE_EXIT_THREAD
20667a929e0SChristoph Hellwig	select HAVE_FAST_GUP
207644e0e8dSSteven Rostedt (VMware)	select HAVE_FENTRY			if X86_64 || DYNAMIC_FTRACE
2086471b825SIngo Molnar	select HAVE_FTRACE_MCOUNT_RECORD
2094a30e4c9SSteven Rostedt (VMware)	select HAVE_FUNCTION_GRAPH_TRACER	if X86_32 || (X86_64 && DYNAMIC_FTRACE)
2106471b825SIngo Molnar	select HAVE_FUNCTION_TRACER
2116b90bd4bSEmese Revfy	select HAVE_GCC_PLUGINS
2120067f129SK.Prasad	select HAVE_HW_BREAKPOINT
2136471b825SIngo Molnar	select HAVE_IOREMAP_PROT
214624db9eaSThomas Gleixner	select HAVE_IRQ_EXIT_ON_IRQ_STACK	if X86_64
2156471b825SIngo Molnar	select HAVE_IRQ_TIME_ACCOUNTING
2166471b825SIngo Molnar	select HAVE_KERNEL_BZIP2
2176471b825SIngo Molnar	select HAVE_KERNEL_GZIP
2186471b825SIngo Molnar	select HAVE_KERNEL_LZ4
2196471b825SIngo Molnar	select HAVE_KERNEL_LZMA
2206471b825SIngo Molnar	select HAVE_KERNEL_LZO
2216471b825SIngo Molnar	select HAVE_KERNEL_XZ
222fb46d057SNick Terrell	select HAVE_KERNEL_ZSTD
2236471b825SIngo Molnar	select HAVE_KPROBES
2246471b825SIngo Molnar	select HAVE_KPROBES_ON_FTRACE
225540adea3SMasami Hiramatsu	select HAVE_FUNCTION_ERROR_INJECTION
2266471b825SIngo Molnar	select HAVE_KRETPROBES
227f3a112c0SMasami Hiramatsu	select HAVE_RETHOOK
2286471b825SIngo Molnar	select HAVE_KVM
2296471b825SIngo Molnar	select HAVE_LIVEPATCH			if X86_64
2300102752eSFrederic Weisbecker	select HAVE_MIXED_BREAKPOINTS_REGS
231ee9f8fceSJosh Poimboeuf	select HAVE_MOD_ARCH_SPECIFIC
2329f132f7eSJoel Fernandes (Google)	select HAVE_MOVE_PMD
233be37c98dSKalesh Singh	select HAVE_MOVE_PUD
23442a0bb3fSPetr Mladek	select HAVE_NMI
2356471b825SIngo Molnar	select HAVE_OPTPROBES
2366471b825SIngo Molnar	select HAVE_PCSPKR_PLATFORM
2376471b825SIngo Molnar	select HAVE_PERF_EVENTS
238c01d4323SFrederic Weisbecker	select HAVE_PERF_EVENTS_NMI
23992e5aae4SNicholas Piggin	select HAVE_HARDLOCKUP_DETECTOR_PERF	if PERF_EVENTS && HAVE_PERF_EVENTS_NMI
240eb01d42aSChristoph Hellwig	select HAVE_PCI
241c5e63197SJiri Olsa	select HAVE_PERF_REGS
242c5ebcedbSJiri Olsa	select HAVE_PERF_USER_STACK_DUMP
243ff2e6d72SPeter Zijlstra	select MMU_GATHER_RCU_TABLE_FREE		if PARAVIRT
24400998085SThomas Gleixner	select HAVE_POSIX_CPU_TIMERS_TASK_WORK
2456471b825SIngo Molnar	select HAVE_REGS_AND_STACK_ACCESS_API
2466415b38bSJiri Slaby	select HAVE_RELIABLE_STACKTRACE		if X86_64 && (UNWINDER_FRAME_POINTER || UNWINDER_ORC) && STACK_VALIDATION
2473c88ee19SMasami Hiramatsu	select HAVE_FUNCTION_ARG_ACCESS_API
2487ecd19cfSKefeng Wang	select HAVE_SETUP_PER_CPU_AREA
249cd1a41ceSThomas Gleixner	select HAVE_SOFTIRQ_ON_OWN_STACK
250d148eac0SMasahiro Yamada	select HAVE_STACKPROTECTOR		if CC_HAS_SANE_STACKPROTECTOR
251c763ea26SIngo Molnar	select HAVE_STACK_VALIDATION		if X86_64
252e6d6c071SJosh Poimboeuf	select HAVE_STATIC_CALL
2531e7e4788SJosh Poimboeuf	select HAVE_STATIC_CALL_INLINE		if HAVE_STACK_VALIDATION
25499cf983cSMark Rutland	select HAVE_PREEMPT_DYNAMIC_CALL
255d6761b8fSMathieu Desnoyers	select HAVE_RSEQ
2566471b825SIngo Molnar	select HAVE_SYSCALL_TRACEPOINTS
2576471b825SIngo Molnar	select HAVE_UNSTABLE_SCHED_CLOCK
2587c68af6eSAvi Kivity	select HAVE_USER_RETURN_NOTIFIER
2597ac87074SVincenzo Frascino	select HAVE_GENERIC_VDSO
26005736e4aSThomas Gleixner	select HOTPLUG_SMT			if SMP
261c0185808SThomas Gleixner	select IRQ_FORCED_THREADING
2627ecd19cfSKefeng Wang	select NEED_PER_CPU_EMBED_FIRST_CHUNK
2637ecd19cfSKefeng Wang	select NEED_PER_CPU_PAGE_FIRST_CHUNK
26486596f0aSChristoph Hellwig	select NEED_SG_DMA_LENGTH
2652eac9c2dSChristoph Hellwig	select PCI_DOMAINS			if PCI
266625210cfSSinan Kaya	select PCI_LOCKLESS_CONFIG		if PCI
2676471b825SIngo Molnar	select PERF_EVENTS
2683195ef59SPrarit Bhargava	select RTC_LIB
269d6faca40SArnd Bergmann	select RTC_MC146818_LIB
2706471b825SIngo Molnar	select SPARSE_IRQ
27183fe27eaSPranith Kumar	select SRCU
2721e7e4788SJosh Poimboeuf	select STACK_VALIDATION			if HAVE_STACK_VALIDATION && (HAVE_STATIC_CALL_INLINE || RETPOLINE)
2736471b825SIngo Molnar	select SYSCTL_EXCEPTION_TRACE
27415f4eae7SAndy Lutomirski	select THREAD_INFO_IN_TASK
2754aae683fSMasahiro Yamada	select TRACE_IRQFLAGS_SUPPORT
2766471b825SIngo Molnar	select USER_STACKTRACE_SUPPORT
2776471b825SIngo Molnar	select VIRT_TO_BUS
2783b02a051SIngo Molnar	select HAVE_ARCH_KCSAN			if X86_64
2796471b825SIngo Molnar	select X86_FEATURE_NAMES		if PROC_FS
2800c608dadSAubrey Li	select PROC_PID_ARCH_STATUS		if PROC_FS
28150468e43SJarkko Sakkinen	select HAVE_ARCH_NODE_DEV_GROUP		if X86_SGX
2829e2b4be3SNayna Jain	imply IMA_SECURE_AND_OR_TRUSTED_BOOT    if EFI
2837d8330a5SBalbir Singh
284ba7e4d13SIngo Molnarconfig INSTRUCTION_DECODER
2853120e25eSJan Beulich	def_bool y
2863120e25eSJan Beulich	depends on KPROBES || PERF_EVENTS || UPROBES
287ba7e4d13SIngo Molnar
28851b26adaSLinus Torvaldsconfig OUTPUT_FORMAT
28951b26adaSLinus Torvalds	string
29051b26adaSLinus Torvalds	default "elf32-i386" if X86_32
29151b26adaSLinus Torvalds	default "elf64-x86-64" if X86_64
29251b26adaSLinus Torvalds
2938d5fffb9SSam Ravnborgconfig LOCKDEP_SUPPORT
2943c2362e6SHarvey Harrison	def_bool y
2958d5fffb9SSam Ravnborg
2968d5fffb9SSam Ravnborgconfig STACKTRACE_SUPPORT
2973c2362e6SHarvey Harrison	def_bool y
2988d5fffb9SSam Ravnborg
2998d5fffb9SSam Ravnborgconfig MMU
3003c2362e6SHarvey Harrison	def_bool y
3018d5fffb9SSam Ravnborg
3029e08f57dSDaniel Cashmanconfig ARCH_MMAP_RND_BITS_MIN
3039e08f57dSDaniel Cashman	default 28 if 64BIT
3049e08f57dSDaniel Cashman	default 8
3059e08f57dSDaniel Cashman
3069e08f57dSDaniel Cashmanconfig ARCH_MMAP_RND_BITS_MAX
3079e08f57dSDaniel Cashman	default 32 if 64BIT
3089e08f57dSDaniel Cashman	default 16
3099e08f57dSDaniel Cashman
3109e08f57dSDaniel Cashmanconfig ARCH_MMAP_RND_COMPAT_BITS_MIN
3119e08f57dSDaniel Cashman	default 8
3129e08f57dSDaniel Cashman
3139e08f57dSDaniel Cashmanconfig ARCH_MMAP_RND_COMPAT_BITS_MAX
3149e08f57dSDaniel Cashman	default 16
3159e08f57dSDaniel Cashman
3168d5fffb9SSam Ravnborgconfig SBUS
3178d5fffb9SSam Ravnborg	bool
3188d5fffb9SSam Ravnborg
3198d5fffb9SSam Ravnborgconfig GENERIC_ISA_DMA
3203120e25eSJan Beulich	def_bool y
3213120e25eSJan Beulich	depends on ISA_DMA_API
3228d5fffb9SSam Ravnborg
3238d5fffb9SSam Ravnborgconfig GENERIC_BUG
3243c2362e6SHarvey Harrison	def_bool y
3258d5fffb9SSam Ravnborg	depends on BUG
326b93a531eSJan Beulich	select GENERIC_BUG_RELATIVE_POINTERS if X86_64
327b93a531eSJan Beulich
328b93a531eSJan Beulichconfig GENERIC_BUG_RELATIVE_POINTERS
329b93a531eSJan Beulich	bool
3308d5fffb9SSam Ravnborg
3318d5fffb9SSam Ravnborgconfig ARCH_MAY_HAVE_PC_FDC
3323120e25eSJan Beulich	def_bool y
3333120e25eSJan Beulich	depends on ISA_DMA_API
3348d5fffb9SSam Ravnborg
3351032c0baSSam Ravnborgconfig GENERIC_CALIBRATE_DELAY
3361032c0baSSam Ravnborg	def_bool y
3371032c0baSSam Ravnborg
3389a0b8415Svenkatesh.pallipadi@intel.comconfig ARCH_HAS_CPU_RELAX
3399a0b8415Svenkatesh.pallipadi@intel.com	def_bool y
3408d5fffb9SSam Ravnborg
341801e4062SJohannes Bergconfig ARCH_HIBERNATION_POSSIBLE
342801e4062SJohannes Berg	def_bool y
343801e4062SJohannes Berg
344d7109fe3SAndy Shevchenkoconfig ARCH_NR_GPIO
345d7109fe3SAndy Shevchenko	int
346d7109fe3SAndy Shevchenko	default 1024 if X86_64
347d7109fe3SAndy Shevchenko	default 512
348d7109fe3SAndy Shevchenko
349f4cb5700SJohannes Bergconfig ARCH_SUSPEND_POSSIBLE
350f4cb5700SJohannes Berg	def_bool y
351f4cb5700SJohannes Berg
3528d5fffb9SSam Ravnborgconfig AUDIT_ARCH
353e0fd24a3SJan Beulich	def_bool y if X86_64
3548d5fffb9SSam Ravnborg
355d6f2d75aSAndrey Ryabininconfig KASAN_SHADOW_OFFSET
356d6f2d75aSAndrey Ryabinin	hex
357d6f2d75aSAndrey Ryabinin	depends on KASAN
358d6f2d75aSAndrey Ryabinin	default 0xdffffc0000000000
359d6f2d75aSAndrey Ryabinin
36069575d38SShane Wangconfig HAVE_INTEL_TXT
36169575d38SShane Wang	def_bool y
3626ea30386SKees Cook	depends on INTEL_IOMMU && ACPI
36369575d38SShane Wang
3646b0c3d44SSam Ravnborgconfig X86_32_SMP
3656b0c3d44SSam Ravnborg	def_bool y
3666b0c3d44SSam Ravnborg	depends on X86_32 && SMP
3676b0c3d44SSam Ravnborg
3686b0c3d44SSam Ravnborgconfig X86_64_SMP
3696b0c3d44SSam Ravnborg	def_bool y
3706b0c3d44SSam Ravnborg	depends on X86_64 && SMP
3716b0c3d44SSam Ravnborg
3722b144498SSrikar Dronamrajuconfig ARCH_SUPPORTS_UPROBES
3732b144498SSrikar Dronamraju	def_bool y
3742b144498SSrikar Dronamraju
375d20642f0SRob Herringconfig FIX_EARLYCON_MEM
376d20642f0SRob Herring	def_bool y
377d20642f0SRob Herring
37894d49eb3SKirill A. Shutemovconfig DYNAMIC_PHYSICAL_MASK
37994d49eb3SKirill A. Shutemov	bool
38094d49eb3SKirill A. Shutemov
38198233368SKirill A. Shutemovconfig PGTABLE_LEVELS
38298233368SKirill A. Shutemov	int
38377ef56e4SKirill A. Shutemov	default 5 if X86_5LEVEL
38498233368SKirill A. Shutemov	default 4 if X86_64
38598233368SKirill A. Shutemov	default 3 if X86_PAE
38698233368SKirill A. Shutemov	default 2
38798233368SKirill A. Shutemov
3882a61f474SMasahiro Yamadaconfig CC_HAS_SANE_STACKPROTECTOR
3892a61f474SMasahiro Yamada	bool
3902a61f474SMasahiro Yamada	default $(success,$(srctree)/scripts/gcc-x86_64-has-stack-protector.sh $(CC)) if 64BIT
3912a61f474SMasahiro Yamada	default $(success,$(srctree)/scripts/gcc-x86_32-has-stack-protector.sh $(CC))
3922a61f474SMasahiro Yamada	help
3932a61f474SMasahiro Yamada	   We have to make sure stack protector is unconditionally disabled if
3943fb0fdb3SAndy Lutomirski	   the compiler produces broken code or if it does not let us control
3953fb0fdb3SAndy Lutomirski	   the segment on 32-bit kernels.
3962a61f474SMasahiro Yamada
397506f1d07SSam Ravnborgmenu "Processor type and features"
398506f1d07SSam Ravnborg
399506f1d07SSam Ravnborgconfig SMP
400506f1d07SSam Ravnborg	bool "Symmetric multi-processing support"
401a7f7f624SMasahiro Yamada	help
402506f1d07SSam Ravnborg	  This enables support for systems with more than one CPU. If you have
4034a474157SRobert Graffham	  a system with only one CPU, say N. If you have a system with more
4044a474157SRobert Graffham	  than one CPU, say Y.
405506f1d07SSam Ravnborg
4064a474157SRobert Graffham	  If you say N here, the kernel will run on uni- and multiprocessor
407506f1d07SSam Ravnborg	  machines, but will use only one CPU of a multiprocessor machine. If
408506f1d07SSam Ravnborg	  you say Y here, the kernel will run on many, but not all,
4094a474157SRobert Graffham	  uniprocessor machines. On a uniprocessor machine, the kernel
410506f1d07SSam Ravnborg	  will run faster if you say N here.
411506f1d07SSam Ravnborg
412506f1d07SSam Ravnborg	  Note that if you say Y here and choose architecture "586" or
413506f1d07SSam Ravnborg	  "Pentium" under "Processor family", the kernel will not work on 486
414506f1d07SSam Ravnborg	  architectures. Similarly, multiprocessor kernels for the "PPro"
415506f1d07SSam Ravnborg	  architecture may not work on all Pentium based boards.
416506f1d07SSam Ravnborg
417506f1d07SSam Ravnborg	  People using multiprocessor machines who say Y here should also say
418506f1d07SSam Ravnborg	  Y to "Enhanced Real Time Clock Support", below. The "Advanced Power
419506f1d07SSam Ravnborg	  Management" code will be disabled if you say Y here.
420506f1d07SSam Ravnborg
421cb1aaebeSMauro Carvalho Chehab	  See also <file:Documentation/x86/i386/IO-APIC.rst>,
4224f4cfa6cSMauro Carvalho Chehab	  <file:Documentation/admin-guide/lockup-watchdogs.rst> and the SMP-HOWTO available at
423506f1d07SSam Ravnborg	  <http://www.tldp.org/docs.html#howto>.
424506f1d07SSam Ravnborg
425506f1d07SSam Ravnborg	  If you don't know what to do here, say N.
426506f1d07SSam Ravnborg
4279def39beSJosh Triplettconfig X86_FEATURE_NAMES
4289def39beSJosh Triplett	bool "Processor feature human-readable names" if EMBEDDED
4299def39beSJosh Triplett	default y
430a7f7f624SMasahiro Yamada	help
4319def39beSJosh Triplett	  This option compiles in a table of x86 feature bits and corresponding
4329def39beSJosh Triplett	  names.  This is required to support /proc/cpuinfo and a few kernel
4339def39beSJosh Triplett	  messages.  You can disable this to save space, at the expense of
4349def39beSJosh Triplett	  making those few kernel messages show numeric feature bits instead.
4359def39beSJosh Triplett
4369def39beSJosh Triplett	  If in doubt, say Y.
4379def39beSJosh Triplett
43806cd9a7dSYinghai Luconfig X86_X2APIC
43906cd9a7dSYinghai Lu	bool "Support x2apic"
44019e3d60dSJan Kiszka	depends on X86_LOCAL_APIC && X86_64 && (IRQ_REMAP || HYPERVISOR_GUEST)
441a7f7f624SMasahiro Yamada	help
44206cd9a7dSYinghai Lu	  This enables x2apic support on CPUs that have this feature.
44306cd9a7dSYinghai Lu
44406cd9a7dSYinghai Lu	  This allows 32-bit apic IDs (so it can support very large systems),
44506cd9a7dSYinghai Lu	  and accesses the local apic via MSRs not via mmio.
44606cd9a7dSYinghai Lu
44706cd9a7dSYinghai Lu	  If you don't know what to do here, say N.
44806cd9a7dSYinghai Lu
4496695c85bSYinghai Luconfig X86_MPPARSE
4504590d98fSAndy Shevchenko	bool "Enable MPS table" if ACPI
4517a527688SJan Beulich	default y
4525ab74722SIngo Molnar	depends on X86_LOCAL_APIC
453a7f7f624SMasahiro Yamada	help
4546695c85bSYinghai Lu	  For old smp systems that do not have proper acpi support. Newer systems
4556695c85bSYinghai Lu	  (esp with 64bit cpus) with acpi support, MADT and DSDT will override it
4566695c85bSYinghai Lu
457ddd70cf9SJun Nakajimaconfig GOLDFISH
458ddd70cf9SJun Nakajima	def_bool y
459ddd70cf9SJun Nakajima	depends on X86_GOLDFISH
460ddd70cf9SJun Nakajima
46176b04384SDavid Woodhouseconfig RETPOLINE
46276b04384SDavid Woodhouse	bool "Avoid speculative indirect branches in kernel"
46376b04384SDavid Woodhouse	default y
46476b04384SDavid Woodhouse	help
46576b04384SDavid Woodhouse	  Compile kernel with the retpoline compiler options to guard against
46676b04384SDavid Woodhouse	  kernel-to-user data leaks by avoiding speculative indirect
46776b04384SDavid Woodhouse	  branches. Requires a compiler with -mindirect-branch=thunk-extern
46876b04384SDavid Woodhouse	  support for full protection. The kernel may run slower.
46976b04384SDavid Woodhouse
470e463a09aSPeter Zijlstraconfig CC_HAS_SLS
471e463a09aSPeter Zijlstra	def_bool $(cc-option,-mharden-sls=all)
472e463a09aSPeter Zijlstra
473e463a09aSPeter Zijlstraconfig SLS
474e463a09aSPeter Zijlstra	bool "Mitigate Straight-Line-Speculation"
475e463a09aSPeter Zijlstra	depends on CC_HAS_SLS && X86_64
476e463a09aSPeter Zijlstra	default n
477e463a09aSPeter Zijlstra	help
478e463a09aSPeter Zijlstra	  Compile the kernel with straight-line-speculation options to guard
479e463a09aSPeter Zijlstra	  against straight line speculation. The kernel image might be slightly
480e463a09aSPeter Zijlstra	  larger.
481e463a09aSPeter Zijlstra
482e6d42931SJohannes Weinerconfig X86_CPU_RESCTRL
483e6d42931SJohannes Weiner	bool "x86 CPU resource control support"
4846fe07ce3SBabu Moger	depends on X86 && (CPU_SUP_INTEL || CPU_SUP_AMD)
48559fe5a77SThomas Gleixner	select KERNFS
486e79f15a4SChen Yu	select PROC_CPU_RESCTRL		if PROC_FS
48778e99b4aSFenghua Yu	help
488e6d42931SJohannes Weiner	  Enable x86 CPU resource control support.
4896fe07ce3SBabu Moger
4906fe07ce3SBabu Moger	  Provide support for the allocation and monitoring of system resources
4916fe07ce3SBabu Moger	  usage by the CPU.
4926fe07ce3SBabu Moger
4936fe07ce3SBabu Moger	  Intel calls this Intel Resource Director Technology
4946fe07ce3SBabu Moger	  (Intel(R) RDT). More information about RDT can be found in the
4956fe07ce3SBabu Moger	  Intel x86 Architecture Software Developer Manual.
4966fe07ce3SBabu Moger
4976fe07ce3SBabu Moger	  AMD calls this AMD Platform Quality of Service (AMD QoS).
4986fe07ce3SBabu Moger	  More information about AMD QoS can be found in the AMD64 Technology
4996fe07ce3SBabu Moger	  Platform Quality of Service Extensions manual.
50078e99b4aSFenghua Yu
50178e99b4aSFenghua Yu	  Say N if unsure.
50278e99b4aSFenghua Yu
5038425091fSRavikiran G Thirumalaiif X86_32
504a0d0bb4dSRandy Dunlapconfig X86_BIGSMP
505a0d0bb4dSRandy Dunlap	bool "Support for big SMP systems with more than 8 CPUs"
506a0d0bb4dSRandy Dunlap	depends on SMP
507a7f7f624SMasahiro Yamada	help
508e133f6eaSRandy Dunlap	  This option is needed for the systems that have more than 8 CPUs.
509a0d0bb4dSRandy Dunlap
510c5c606d9SRavikiran G Thirumalaiconfig X86_EXTENDED_PLATFORM
511c5c606d9SRavikiran G Thirumalai	bool "Support for extended (non-PC) x86 platforms"
512c5c606d9SRavikiran G Thirumalai	default y
513a7f7f624SMasahiro Yamada	help
51406ac8346SIngo Molnar	  If you disable this option then the kernel will only support
51506ac8346SIngo Molnar	  standard PC platforms. (which covers the vast majority of
51606ac8346SIngo Molnar	  systems out there.)
51706ac8346SIngo Molnar
5188425091fSRavikiran G Thirumalai	  If you enable this option then you'll be able to select support
5198425091fSRavikiran G Thirumalai	  for the following (non-PC) 32 bit x86 platforms:
520cb7b8023SBen Hutchings		Goldfish (Android emulator)
5218425091fSRavikiran G Thirumalai		AMD Elan
5228425091fSRavikiran G Thirumalai		RDC R-321x SoC
5238425091fSRavikiran G Thirumalai		SGI 320/540 (Visual Workstation)
52483125a3aSAlessandro Rubini		STA2X11-based (e.g. Northville)
5253f4110a4SThomas Gleixner		Moorestown MID devices
52606ac8346SIngo Molnar
52706ac8346SIngo Molnar	  If you have one of these systems, or if you want to build a
52806ac8346SIngo Molnar	  generic distribution kernel, say Y here - otherwise say N.
5298425091fSRavikiran G Thirumalaiendif
53006ac8346SIngo Molnar
5318425091fSRavikiran G Thirumalaiif X86_64
5328425091fSRavikiran G Thirumalaiconfig X86_EXTENDED_PLATFORM
5338425091fSRavikiran G Thirumalai	bool "Support for extended (non-PC) x86 platforms"
5348425091fSRavikiran G Thirumalai	default y
535a7f7f624SMasahiro Yamada	help
5368425091fSRavikiran G Thirumalai	  If you disable this option then the kernel will only support
5378425091fSRavikiran G Thirumalai	  standard PC platforms. (which covers the vast majority of
5388425091fSRavikiran G Thirumalai	  systems out there.)
5398425091fSRavikiran G Thirumalai
5408425091fSRavikiran G Thirumalai	  If you enable this option then you'll be able to select support
5418425091fSRavikiran G Thirumalai	  for the following (non-PC) 64 bit x86 platforms:
54244b111b5SSteffen Persvold		Numascale NumaChip
5438425091fSRavikiran G Thirumalai		ScaleMP vSMP
5448425091fSRavikiran G Thirumalai		SGI Ultraviolet
5458425091fSRavikiran G Thirumalai
5468425091fSRavikiran G Thirumalai	  If you have one of these systems, or if you want to build a
5478425091fSRavikiran G Thirumalai	  generic distribution kernel, say Y here - otherwise say N.
5488425091fSRavikiran G Thirumalaiendif
549c5c606d9SRavikiran G Thirumalai# This is an alphabetically sorted list of 64 bit extended platforms
550c5c606d9SRavikiran G Thirumalai# Please maintain the alphabetic order if and when there are additions
55144b111b5SSteffen Persvoldconfig X86_NUMACHIP
55244b111b5SSteffen Persvold	bool "Numascale NumaChip"
55344b111b5SSteffen Persvold	depends on X86_64
55444b111b5SSteffen Persvold	depends on X86_EXTENDED_PLATFORM
55544b111b5SSteffen Persvold	depends on NUMA
55644b111b5SSteffen Persvold	depends on SMP
55744b111b5SSteffen Persvold	depends on X86_X2APIC
558f9726bfdSDaniel J Blueman	depends on PCI_MMCONFIG
559a7f7f624SMasahiro Yamada	help
56044b111b5SSteffen Persvold	  Adds support for Numascale NumaChip large-SMP systems. Needed to
56144b111b5SSteffen Persvold	  enable more than ~168 cores.
56244b111b5SSteffen Persvold	  If you don't have one of these, you should say N here.
56303b48632SNick Piggin
5646a48565eSIngo Molnarconfig X86_VSMP
565c5c606d9SRavikiran G Thirumalai	bool "ScaleMP vSMP"
5666276a074SBorislav Petkov	select HYPERVISOR_GUEST
5676a48565eSIngo Molnar	select PARAVIRT
5686a48565eSIngo Molnar	depends on X86_64 && PCI
569c5c606d9SRavikiran G Thirumalai	depends on X86_EXTENDED_PLATFORM
570ead91d4bSShai Fultheim	depends on SMP
571a7f7f624SMasahiro Yamada	help
5726a48565eSIngo Molnar	  Support for ScaleMP vSMP systems.  Say 'Y' here if this kernel is
5736a48565eSIngo Molnar	  supposed to run on these EM64T-based machines.  Only choose this option
5746a48565eSIngo Molnar	  if you have one of these machines.
5756a48565eSIngo Molnar
576c5c606d9SRavikiran G Thirumalaiconfig X86_UV
577c5c606d9SRavikiran G Thirumalai	bool "SGI Ultraviolet"
578c5c606d9SRavikiran G Thirumalai	depends on X86_64
579c5c606d9SRavikiran G Thirumalai	depends on X86_EXTENDED_PLATFORM
58054c28d29SJack Steiner	depends on NUMA
5811ecb4ae5SAndrew Morton	depends on EFI
582c2209ea5SIngo Molnar	depends on KEXEC_CORE
5839d6c26e7SSuresh Siddha	depends on X86_X2APIC
5841222e564SIngo Molnar	depends on PCI
585a7f7f624SMasahiro Yamada	help
586c5c606d9SRavikiran G Thirumalai	  This option is needed in order to support SGI Ultraviolet systems.
587c5c606d9SRavikiran G Thirumalai	  If you don't have one of these, you should say N here.
588c5c606d9SRavikiran G Thirumalai
589c5c606d9SRavikiran G Thirumalai# Following is an alphabetically sorted list of 32 bit extended platforms
590c5c606d9SRavikiran G Thirumalai# Please maintain the alphabetic order if and when there are additions
591506f1d07SSam Ravnborg
592ddd70cf9SJun Nakajimaconfig X86_GOLDFISH
593ddd70cf9SJun Nakajima	bool "Goldfish (Virtual Platform)"
594cb7b8023SBen Hutchings	depends on X86_EXTENDED_PLATFORM
595a7f7f624SMasahiro Yamada	help
596ddd70cf9SJun Nakajima	 Enable support for the Goldfish virtual platform used primarily
597ddd70cf9SJun Nakajima	 for Android development. Unless you are building for the Android
598ddd70cf9SJun Nakajima	 Goldfish emulator say N here.
599ddd70cf9SJun Nakajima
600c751e17bSThomas Gleixnerconfig X86_INTEL_CE
601c751e17bSThomas Gleixner	bool "CE4100 TV platform"
602c751e17bSThomas Gleixner	depends on PCI
603c751e17bSThomas Gleixner	depends on PCI_GODIRECT
6046084a6e2SJiang Liu	depends on X86_IO_APIC
605c751e17bSThomas Gleixner	depends on X86_32
606c751e17bSThomas Gleixner	depends on X86_EXTENDED_PLATFORM
60737bc9f50SDirk Brandewie	select X86_REBOOTFIXUPS
608da6b737bSSebastian Andrzej Siewior	select OF
609da6b737bSSebastian Andrzej Siewior	select OF_EARLY_FLATTREE
610a7f7f624SMasahiro Yamada	help
611c751e17bSThomas Gleixner	  Select for the Intel CE media processor (CE4100) SOC.
612c751e17bSThomas Gleixner	  This option compiles in support for the CE4100 SOC for settop
613c751e17bSThomas Gleixner	  boxes and media devices.
614c751e17bSThomas Gleixner
6154cb9b00fSDavid Cohenconfig X86_INTEL_MID
61643605ef1SAlan Cox	bool "Intel MID platform support"
61743605ef1SAlan Cox	depends on X86_EXTENDED_PLATFORM
618edc6bc78SDavid Cohen	depends on X86_PLATFORM_DEVICES
6191ea7c673SAlan Cox	depends on PCI
6203fda5bb4SAndy Shevchenko	depends on X86_64 || (PCI_GOANY && X86_32)
6211ea7c673SAlan Cox	depends on X86_IO_APIC
6224cb9b00fSDavid Cohen	select I2C
6237c9c3a1eSAlan Cox	select DW_APB_TIMER
62454b34aa0SMika Westerberg	select INTEL_SCU_PCI
625a7f7f624SMasahiro Yamada	help
6264cb9b00fSDavid Cohen	  Select to build a kernel capable of supporting Intel MID (Mobile
6274cb9b00fSDavid Cohen	  Internet Device) platform systems which do not have the PCI legacy
6284cb9b00fSDavid Cohen	  interfaces. If you are building for a PC class system say N here.
6291ea7c673SAlan Cox
6304cb9b00fSDavid Cohen	  Intel MID platforms are based on an Intel processor and chipset which
6314cb9b00fSDavid Cohen	  consume less power than most of the x86 derivatives.
63243605ef1SAlan Cox
6338bbc2a13SBryan O'Donoghueconfig X86_INTEL_QUARK
6348bbc2a13SBryan O'Donoghue	bool "Intel Quark platform support"
6358bbc2a13SBryan O'Donoghue	depends on X86_32
6368bbc2a13SBryan O'Donoghue	depends on X86_EXTENDED_PLATFORM
6378bbc2a13SBryan O'Donoghue	depends on X86_PLATFORM_DEVICES
6388bbc2a13SBryan O'Donoghue	depends on X86_TSC
6398bbc2a13SBryan O'Donoghue	depends on PCI
6408bbc2a13SBryan O'Donoghue	depends on PCI_GOANY
6418bbc2a13SBryan O'Donoghue	depends on X86_IO_APIC
6428bbc2a13SBryan O'Donoghue	select IOSF_MBI
6438bbc2a13SBryan O'Donoghue	select INTEL_IMR
6449ab6eb51SAndy Shevchenko	select COMMON_CLK
645a7f7f624SMasahiro Yamada	help
6468bbc2a13SBryan O'Donoghue	  Select to include support for Quark X1000 SoC.
6478bbc2a13SBryan O'Donoghue	  Say Y here if you have a Quark based system such as the Arduino
6488bbc2a13SBryan O'Donoghue	  compatible Intel Galileo.
6498bbc2a13SBryan O'Donoghue
6503d48aab1SMika Westerbergconfig X86_INTEL_LPSS
6513d48aab1SMika Westerberg	bool "Intel Low Power Subsystem Support"
6525962dd22SSinan Kaya	depends on X86 && ACPI && PCI
6533d48aab1SMika Westerberg	select COMMON_CLK
6540f531431SMathias Nyman	select PINCTRL
655eebb3e8dSAndy Shevchenko	select IOSF_MBI
656a7f7f624SMasahiro Yamada	help
6573d48aab1SMika Westerberg	  Select to build support for Intel Low Power Subsystem such as
6583d48aab1SMika Westerberg	  found on Intel Lynxpoint PCH. Selecting this option enables
6590f531431SMathias Nyman	  things like clock tree (common clock framework) and pincontrol
6600f531431SMathias Nyman	  which are needed by the LPSS peripheral drivers.
6613d48aab1SMika Westerberg
66292082a88SKen Xueconfig X86_AMD_PLATFORM_DEVICE
66392082a88SKen Xue	bool "AMD ACPI2Platform devices support"
66492082a88SKen Xue	depends on ACPI
66592082a88SKen Xue	select COMMON_CLK
66692082a88SKen Xue	select PINCTRL
667a7f7f624SMasahiro Yamada	help
66892082a88SKen Xue	  Select to interpret AMD specific ACPI device to platform device
66992082a88SKen Xue	  such as I2C, UART, GPIO found on AMD Carrizo and later chipsets.
67092082a88SKen Xue	  I2C and UART depend on COMMON_CLK to set clock. GPIO driver is
67192082a88SKen Xue	  implemented under PINCTRL subsystem.
67292082a88SKen Xue
673ced3ce76SDavid E. Boxconfig IOSF_MBI
674ced3ce76SDavid E. Box	tristate "Intel SoC IOSF Sideband support for SoC platforms"
675ced3ce76SDavid E. Box	depends on PCI
676a7f7f624SMasahiro Yamada	help
677ced3ce76SDavid E. Box	  This option enables sideband register access support for Intel SoC
678ced3ce76SDavid E. Box	  platforms. On these platforms the IOSF sideband is used in lieu of
679ced3ce76SDavid E. Box	  MSR's for some register accesses, mostly but not limited to thermal
680ced3ce76SDavid E. Box	  and power. Drivers may query the availability of this device to
681ced3ce76SDavid E. Box	  determine if they need the sideband in order to work on these
682ced3ce76SDavid E. Box	  platforms. The sideband is available on the following SoC products.
683ced3ce76SDavid E. Box	  This list is not meant to be exclusive.
684ced3ce76SDavid E. Box	   - BayTrail
685ced3ce76SDavid E. Box	   - Braswell
686ced3ce76SDavid E. Box	   - Quark
687ced3ce76SDavid E. Box
688ced3ce76SDavid E. Box	  You should say Y if you are running a kernel on one of these SoC's.
689ced3ce76SDavid E. Box
690ed2226bdSDavid E. Boxconfig IOSF_MBI_DEBUG
691ed2226bdSDavid E. Box	bool "Enable IOSF sideband access through debugfs"
692ed2226bdSDavid E. Box	depends on IOSF_MBI && DEBUG_FS
693a7f7f624SMasahiro Yamada	help
694ed2226bdSDavid E. Box	  Select this option to expose the IOSF sideband access registers (MCR,
695ed2226bdSDavid E. Box	  MDR, MCRX) through debugfs to write and read register information from
696ed2226bdSDavid E. Box	  different units on the SoC. This is most useful for obtaining device
697ed2226bdSDavid E. Box	  state information for debug and analysis. As this is a general access
698ed2226bdSDavid E. Box	  mechanism, users of this option would have specific knowledge of the
699ed2226bdSDavid E. Box	  device they want to access.
700ed2226bdSDavid E. Box
701ed2226bdSDavid E. Box	  If you don't require the option or are in doubt, say N.
702ed2226bdSDavid E. Box
703c5c606d9SRavikiran G Thirumalaiconfig X86_RDC321X
704c5c606d9SRavikiran G Thirumalai	bool "RDC R-321x SoC"
705506f1d07SSam Ravnborg	depends on X86_32
706c5c606d9SRavikiran G Thirumalai	depends on X86_EXTENDED_PLATFORM
707c5c606d9SRavikiran G Thirumalai	select M486
708c5c606d9SRavikiran G Thirumalai	select X86_REBOOTFIXUPS
709a7f7f624SMasahiro Yamada	help
710c5c606d9SRavikiran G Thirumalai	  This option is needed for RDC R-321x system-on-chip, also known
711c5c606d9SRavikiran G Thirumalai	  as R-8610-(G).
712c5c606d9SRavikiran G Thirumalai	  If you don't have one of these chips, you should say N here.
713c5c606d9SRavikiran G Thirumalai
714e0c7ae37SIngo Molnarconfig X86_32_NON_STANDARD
7159c398017SIngo Molnar	bool "Support non-standard 32-bit SMP architectures"
7169c398017SIngo Molnar	depends on X86_32 && SMP
717c5c606d9SRavikiran G Thirumalai	depends on X86_EXTENDED_PLATFORM
718a7f7f624SMasahiro Yamada	help
719b5660ba7SH. Peter Anvin	  This option compiles in the bigsmp and STA2X11 default
720b5660ba7SH. Peter Anvin	  subarchitectures.  It is intended for a generic binary
721b5660ba7SH. Peter Anvin	  kernel. If you select them all, kernel will probe it one by
722b5660ba7SH. Peter Anvin	  one and will fallback to default.
723d49c4288SYinghai Lu
724c5c606d9SRavikiran G Thirumalai# Alphabetically sorted list of Non standard 32 bit platforms
725d49c4288SYinghai Lu
726d949f36fSLinus Torvaldsconfig X86_SUPPORTS_MEMORY_FAILURE
7276fc108a0SJan Beulich	def_bool y
728d949f36fSLinus Torvalds	# MCE code calls memory_failure():
729d949f36fSLinus Torvalds	depends on X86_MCE
730d949f36fSLinus Torvalds	# On 32-bit this adds too big of NODES_SHIFT and we run out of page flags:
731d949f36fSLinus Torvalds	# On 32-bit SPARSEMEM adds too big of SECTIONS_WIDTH:
732d949f36fSLinus Torvalds	depends on X86_64 || !SPARSEMEM
733d949f36fSLinus Torvalds	select ARCH_SUPPORTS_MEMORY_FAILURE
734d949f36fSLinus Torvalds
73583125a3aSAlessandro Rubiniconfig STA2X11
73683125a3aSAlessandro Rubini	bool "STA2X11 Companion Chip Support"
73783125a3aSAlessandro Rubini	depends on X86_32_NON_STANDARD && PCI
73883125a3aSAlessandro Rubini	select SWIOTLB
73983125a3aSAlessandro Rubini	select MFD_STA2X11
7400145071bSLinus Walleij	select GPIOLIB
741a7f7f624SMasahiro Yamada	help
74283125a3aSAlessandro Rubini	  This adds support for boards based on the STA2X11 IO-Hub,
74383125a3aSAlessandro Rubini	  a.k.a. "ConneXt". The chip is used in place of the standard
74483125a3aSAlessandro Rubini	  PC chipset, so all "standard" peripherals are missing. If this
74583125a3aSAlessandro Rubini	  option is selected the kernel will still be able to boot on
74683125a3aSAlessandro Rubini	  standard PC machines.
74783125a3aSAlessandro Rubini
74882148d1dSShérabconfig X86_32_IRIS
74982148d1dSShérab	tristate "Eurobraille/Iris poweroff module"
75082148d1dSShérab	depends on X86_32
751a7f7f624SMasahiro Yamada	help
75282148d1dSShérab	  The Iris machines from EuroBraille do not have APM or ACPI support
75382148d1dSShérab	  to shut themselves down properly.  A special I/O sequence is
75482148d1dSShérab	  needed to do so, which is what this module does at
75582148d1dSShérab	  kernel shutdown.
75682148d1dSShérab
75782148d1dSShérab	  This is only for Iris machines from EuroBraille.
75882148d1dSShérab
75982148d1dSShérab	  If unused, say N.
76082148d1dSShérab
761ae1e9130SIngo Molnarconfig SCHED_OMIT_FRAME_POINTER
7623c2362e6SHarvey Harrison	def_bool y
7633c2362e6SHarvey Harrison	prompt "Single-depth WCHAN output"
764a87d0914SKen Chen	depends on X86
765a7f7f624SMasahiro Yamada	help
766506f1d07SSam Ravnborg	  Calculate simpler /proc/<PID>/wchan values. If this option
767506f1d07SSam Ravnborg	  is disabled then wchan values will recurse back to the
768506f1d07SSam Ravnborg	  caller function. This provides more accurate wchan values,
769506f1d07SSam Ravnborg	  at the expense of slightly more scheduling overhead.
770506f1d07SSam Ravnborg
771506f1d07SSam Ravnborg	  If in doubt, say "Y".
772506f1d07SSam Ravnborg
7736276a074SBorislav Petkovmenuconfig HYPERVISOR_GUEST
7746276a074SBorislav Petkov	bool "Linux guest support"
775a7f7f624SMasahiro Yamada	help
7766276a074SBorislav Petkov	  Say Y here to enable options for running Linux under various hyper-
7776276a074SBorislav Petkov	  visors. This option enables basic hypervisor detection and platform
7786276a074SBorislav Petkov	  setup.
779506f1d07SSam Ravnborg
7806276a074SBorislav Petkov	  If you say N, all options in this submenu will be skipped and
7816276a074SBorislav Petkov	  disabled, and Linux guest support won't be built in.
782506f1d07SSam Ravnborg
7836276a074SBorislav Petkovif HYPERVISOR_GUEST
784506f1d07SSam Ravnborg
785e61bd94aSEduardo Pereira Habkostconfig PARAVIRT
786e61bd94aSEduardo Pereira Habkost	bool "Enable paravirtualization code"
787a0e2bf7cSJuergen Gross	depends on HAVE_STATIC_CALL
788a7f7f624SMasahiro Yamada	help
789e61bd94aSEduardo Pereira Habkost	  This changes the kernel so it can modify itself when it is run
790e61bd94aSEduardo Pereira Habkost	  under a hypervisor, potentially improving performance significantly
791e61bd94aSEduardo Pereira Habkost	  over full virtualization.  However, when run without a hypervisor
792e61bd94aSEduardo Pereira Habkost	  the kernel is theoretically slower and slightly larger.
793e61bd94aSEduardo Pereira Habkost
794c00a280aSJuergen Grossconfig PARAVIRT_XXL
795c00a280aSJuergen Gross	bool
796c00a280aSJuergen Gross
7976276a074SBorislav Petkovconfig PARAVIRT_DEBUG
7986276a074SBorislav Petkov	bool "paravirt-ops debugging"
7996276a074SBorislav Petkov	depends on PARAVIRT && DEBUG_KERNEL
800a7f7f624SMasahiro Yamada	help
8016276a074SBorislav Petkov	  Enable to debug paravirt_ops internals.  Specifically, BUG if
8026276a074SBorislav Petkov	  a paravirt_op is missing when it is called.
8036276a074SBorislav Petkov
804b4ecc126SJeremy Fitzhardingeconfig PARAVIRT_SPINLOCKS
805b4ecc126SJeremy Fitzhardinge	bool "Paravirtualization layer for spinlocks"
8066ea30386SKees Cook	depends on PARAVIRT && SMP
807a7f7f624SMasahiro Yamada	help
808b4ecc126SJeremy Fitzhardinge	  Paravirtualized spinlocks allow a pvops backend to replace the
809b4ecc126SJeremy Fitzhardinge	  spinlock implementation with something virtualization-friendly
810b4ecc126SJeremy Fitzhardinge	  (for example, block the virtual CPU rather than spinning).
811b4ecc126SJeremy Fitzhardinge
8124c4e4f61SRaghavendra K T	  It has a minimal impact on native kernels and gives a nice performance
8134c4e4f61SRaghavendra K T	  benefit on paravirtualized KVM / Xen kernels.
814b4ecc126SJeremy Fitzhardinge
8154c4e4f61SRaghavendra K T	  If you are unsure how to answer this question, answer Y.
816b4ecc126SJeremy Fitzhardinge
817ecca2502SZhao Yakuiconfig X86_HV_CALLBACK_VECTOR
818ecca2502SZhao Yakui	def_bool n
819ecca2502SZhao Yakui
8206276a074SBorislav Petkovsource "arch/x86/xen/Kconfig"
8216276a074SBorislav Petkov
8226276a074SBorislav Petkovconfig KVM_GUEST
8236276a074SBorislav Petkov	bool "KVM Guest support (including kvmclock)"
8246276a074SBorislav Petkov	depends on PARAVIRT
8256276a074SBorislav Petkov	select PARAVIRT_CLOCK
826a1c4423bSMarcelo Tosatti	select ARCH_CPUIDLE_HALTPOLL
827b1d40575SVitaly Kuznetsov	select X86_HV_CALLBACK_VECTOR
8286276a074SBorislav Petkov	default y
829a7f7f624SMasahiro Yamada	help
8306276a074SBorislav Petkov	  This option enables various optimizations for running under the KVM
8316276a074SBorislav Petkov	  hypervisor. It includes a paravirtualized clock, so that instead
8326276a074SBorislav Petkov	  of relying on a PIT (or probably other) emulation by the
8336276a074SBorislav Petkov	  underlying device model, the host provides the guest with
8346276a074SBorislav Petkov	  timing infrastructure such as time of day, and system time
8356276a074SBorislav Petkov
836a1c4423bSMarcelo Tosatticonfig ARCH_CPUIDLE_HALTPOLL
837a1c4423bSMarcelo Tosatti	def_bool n
838a1c4423bSMarcelo Tosatti	prompt "Disable host haltpoll when loading haltpoll driver"
839a1c4423bSMarcelo Tosatti	help
840a1c4423bSMarcelo Tosatti	  If virtualized under KVM, disable host haltpoll.
841a1c4423bSMarcelo Tosatti
8427733607fSMaran Wilsonconfig PVH
8437733607fSMaran Wilson	bool "Support for running PVH guests"
844a7f7f624SMasahiro Yamada	help
8457733607fSMaran Wilson	  This option enables the PVH entry point for guest virtual machines
8467733607fSMaran Wilson	  as specified in the x86/HVM direct boot ABI.
8477733607fSMaran Wilson
8486276a074SBorislav Petkovconfig PARAVIRT_TIME_ACCOUNTING
8496276a074SBorislav Petkov	bool "Paravirtual steal time accounting"
8506276a074SBorislav Petkov	depends on PARAVIRT
851a7f7f624SMasahiro Yamada	help
8526276a074SBorislav Petkov	  Select this option to enable fine granularity task steal time
8536276a074SBorislav Petkov	  accounting. Time spent executing other tasks in parallel with
8546276a074SBorislav Petkov	  the current vCPU is discounted from the vCPU power. To account for
8556276a074SBorislav Petkov	  that, there can be a small performance impact.
8566276a074SBorislav Petkov
8576276a074SBorislav Petkov	  If in doubt, say N here.
8586276a074SBorislav Petkov
8597af192c9SGerd Hoffmannconfig PARAVIRT_CLOCK
8607af192c9SGerd Hoffmann	bool
8617af192c9SGerd Hoffmann
8624a362601SJan Kiszkaconfig JAILHOUSE_GUEST
8634a362601SJan Kiszka	bool "Jailhouse non-root cell support"
864abde587bSArnd Bergmann	depends on X86_64 && PCI
86587e65d05SJan Kiszka	select X86_PM_TIMER
866a7f7f624SMasahiro Yamada	help
8674a362601SJan Kiszka	  This option allows to run Linux as guest in a Jailhouse non-root
8684a362601SJan Kiszka	  cell. You can leave this option disabled if you only want to start
8694a362601SJan Kiszka	  Jailhouse and run Linux afterwards in the root cell.
8704a362601SJan Kiszka
871ec7972c9SZhao Yakuiconfig ACRN_GUEST
872ec7972c9SZhao Yakui	bool "ACRN Guest support"
873ec7972c9SZhao Yakui	depends on X86_64
874498ad393SZhao Yakui	select X86_HV_CALLBACK_VECTOR
875ec7972c9SZhao Yakui	help
876ec7972c9SZhao Yakui	  This option allows to run Linux as guest in the ACRN hypervisor. ACRN is
877ec7972c9SZhao Yakui	  a flexible, lightweight reference open-source hypervisor, built with
878ec7972c9SZhao Yakui	  real-time and safety-criticality in mind. It is built for embedded
879ec7972c9SZhao Yakui	  IOT with small footprint and real-time features. More details can be
880ec7972c9SZhao Yakui	  found in https://projectacrn.org/.
881ec7972c9SZhao Yakui
8826276a074SBorislav Petkovendif #HYPERVISOR_GUEST
88397349135SJeremy Fitzhardinge
884506f1d07SSam Ravnborgsource "arch/x86/Kconfig.cpu"
885506f1d07SSam Ravnborg
886506f1d07SSam Ravnborgconfig HPET_TIMER
8873c2362e6SHarvey Harrison	def_bool X86_64
888506f1d07SSam Ravnborg	prompt "HPET Timer Support" if X86_32
889a7f7f624SMasahiro Yamada	help
890506f1d07SSam Ravnborg	  Use the IA-PC HPET (High Precision Event Timer) to manage
891506f1d07SSam Ravnborg	  time in preference to the PIT and RTC, if a HPET is
892506f1d07SSam Ravnborg	  present.
893506f1d07SSam Ravnborg	  HPET is the next generation timer replacing legacy 8254s.
894506f1d07SSam Ravnborg	  The HPET provides a stable time base on SMP
895506f1d07SSam Ravnborg	  systems, unlike the TSC, but it is more expensive to access,
8964e7f9df2SMichael S. Tsirkin	  as it is off-chip.  The interface used is documented
8974e7f9df2SMichael S. Tsirkin	  in the HPET spec, revision 1.
898506f1d07SSam Ravnborg
899506f1d07SSam Ravnborg	  You can safely choose Y here.  However, HPET will only be
900506f1d07SSam Ravnborg	  activated if the platform and the BIOS support this feature.
901506f1d07SSam Ravnborg	  Otherwise the 8254 will be used for timing services.
902506f1d07SSam Ravnborg
903506f1d07SSam Ravnborg	  Choose N to continue using the legacy 8254 timer.
904506f1d07SSam Ravnborg
905506f1d07SSam Ravnborgconfig HPET_EMULATE_RTC
9063c2362e6SHarvey Harrison	def_bool y
9073228e1dcSAnand K Mistry	depends on HPET_TIMER && (RTC_DRV_CMOS=m || RTC_DRV_CMOS=y)
908506f1d07SSam Ravnborg
9096a108a14SDavid Rientjes# Mark as expert because too many people got it wrong.
910506f1d07SSam Ravnborg# The code disables itself when not needed.
9117ae9392cSThomas Petazzoniconfig DMI
9127ae9392cSThomas Petazzoni	default y
913cf074402SArd Biesheuvel	select DMI_SCAN_MACHINE_NON_EFI_FALLBACK
9146a108a14SDavid Rientjes	bool "Enable DMI scanning" if EXPERT
915a7f7f624SMasahiro Yamada	help
9167ae9392cSThomas Petazzoni	  Enabled scanning of DMI to identify machine quirks. Say Y
9177ae9392cSThomas Petazzoni	  here unless you have verified that your setup is not
9187ae9392cSThomas Petazzoni	  affected by entries in the DMI blacklist. Required by PNP
9197ae9392cSThomas Petazzoni	  BIOS code.
9207ae9392cSThomas Petazzoni
921506f1d07SSam Ravnborgconfig GART_IOMMU
92238901f1cSAndi Kleen	bool "Old AMD GART IOMMU support"
9232f9237d4SChristoph Hellwig	select DMA_OPS
924a4ce5a48SChristoph Hellwig	select IOMMU_HELPER
925506f1d07SSam Ravnborg	select SWIOTLB
92623ac4ae8SAndreas Herrmann	depends on X86_64 && PCI && AMD_NB
927a7f7f624SMasahiro Yamada	help
928ced3c42cSIngo Molnar	  Provides a driver for older AMD Athlon64/Opteron/Turion/Sempron
929ced3c42cSIngo Molnar	  GART based hardware IOMMUs.
930ced3c42cSIngo Molnar
931ced3c42cSIngo Molnar	  The GART supports full DMA access for devices with 32-bit access
932ced3c42cSIngo Molnar	  limitations, on systems with more than 3 GB. This is usually needed
933ced3c42cSIngo Molnar	  for USB, sound, many IDE/SATA chipsets and some other devices.
934ced3c42cSIngo Molnar
935ced3c42cSIngo Molnar	  Newer systems typically have a modern AMD IOMMU, supported via
936ced3c42cSIngo Molnar	  the CONFIG_AMD_IOMMU=y config option.
937ced3c42cSIngo Molnar
938ced3c42cSIngo Molnar	  In normal configurations this driver is only active when needed:
939ced3c42cSIngo Molnar	  there's more than 3 GB of memory and the system contains a
940ced3c42cSIngo Molnar	  32-bit limited device.
941ced3c42cSIngo Molnar
942ced3c42cSIngo Molnar	  If unsure, say Y.
943506f1d07SSam Ravnborg
9441184dc2fSMike Travisconfig MAXSMP
945ddb0c5a6SSamuel Thibault	bool "Enable Maximum number of SMP Processors and NUMA Nodes"
9466ea30386SKees Cook	depends on X86_64 && SMP && DEBUG_KERNEL
94736f5101aSMike Travis	select CPUMASK_OFFSTACK
948a7f7f624SMasahiro Yamada	help
949ddb0c5a6SSamuel Thibault	  Enable maximum number of CPUS and NUMA Nodes for this architecture.
9501184dc2fSMike Travis	  If unsure, say N.
951506f1d07SSam Ravnborg
952aec6487eSIngo Molnar#
953aec6487eSIngo Molnar# The maximum number of CPUs supported:
954aec6487eSIngo Molnar#
955aec6487eSIngo Molnar# The main config value is NR_CPUS, which defaults to NR_CPUS_DEFAULT,
956aec6487eSIngo Molnar# and which can be configured interactively in the
957aec6487eSIngo Molnar# [NR_CPUS_RANGE_BEGIN ... NR_CPUS_RANGE_END] range.
958aec6487eSIngo Molnar#
959aec6487eSIngo Molnar# The ranges are different on 32-bit and 64-bit kernels, depending on
960aec6487eSIngo Molnar# hardware capabilities and scalability features of the kernel.
961aec6487eSIngo Molnar#
962aec6487eSIngo Molnar# ( If MAXSMP is enabled we just use the highest possible value and disable
963aec6487eSIngo Molnar#   interactive configuration. )
964aec6487eSIngo Molnar#
965a0d0bb4dSRandy Dunlap
966aec6487eSIngo Molnarconfig NR_CPUS_RANGE_BEGIN
967a0d0bb4dSRandy Dunlap	int
968aec6487eSIngo Molnar	default NR_CPUS_RANGE_END if MAXSMP
969a0d0bb4dSRandy Dunlap	default    1 if !SMP
970a0d0bb4dSRandy Dunlap	default    2
971a0d0bb4dSRandy Dunlap
972aec6487eSIngo Molnarconfig NR_CPUS_RANGE_END
973a0d0bb4dSRandy Dunlap	int
974a0d0bb4dSRandy Dunlap	depends on X86_32
975aec6487eSIngo Molnar	default   64 if  SMP &&  X86_BIGSMP
976aec6487eSIngo Molnar	default    8 if  SMP && !X86_BIGSMP
977a0d0bb4dSRandy Dunlap	default    1 if !SMP
978a0d0bb4dSRandy Dunlap
979aec6487eSIngo Molnarconfig NR_CPUS_RANGE_END
980a0d0bb4dSRandy Dunlap	int
981a0d0bb4dSRandy Dunlap	depends on X86_64
9821edae1aeSScott Wood	default 8192 if  SMP && CPUMASK_OFFSTACK
9831edae1aeSScott Wood	default  512 if  SMP && !CPUMASK_OFFSTACK
984a0d0bb4dSRandy Dunlap	default    1 if !SMP
985aec6487eSIngo Molnar
986aec6487eSIngo Molnarconfig NR_CPUS_DEFAULT
987aec6487eSIngo Molnar	int
988aec6487eSIngo Molnar	depends on X86_32
989aec6487eSIngo Molnar	default   32 if  X86_BIGSMP
990aec6487eSIngo Molnar	default    8 if  SMP
991aec6487eSIngo Molnar	default    1 if !SMP
992aec6487eSIngo Molnar
993aec6487eSIngo Molnarconfig NR_CPUS_DEFAULT
994aec6487eSIngo Molnar	int
995aec6487eSIngo Molnar	depends on X86_64
996a0d0bb4dSRandy Dunlap	default 8192 if  MAXSMP
997a0d0bb4dSRandy Dunlap	default   64 if  SMP
998aec6487eSIngo Molnar	default    1 if !SMP
999a0d0bb4dSRandy Dunlap
1000506f1d07SSam Ravnborgconfig NR_CPUS
100136f5101aSMike Travis	int "Maximum number of CPUs" if SMP && !MAXSMP
1002aec6487eSIngo Molnar	range NR_CPUS_RANGE_BEGIN NR_CPUS_RANGE_END
1003aec6487eSIngo Molnar	default NR_CPUS_DEFAULT
1004a7f7f624SMasahiro Yamada	help
1005506f1d07SSam Ravnborg	  This allows you to specify the maximum number of CPUs which this
1006bb61ccc7SJosh Boyer	  kernel will support.  If CPUMASK_OFFSTACK is enabled, the maximum
1007cad14bb9SKirill A. Shutemov	  supported value is 8192, otherwise the maximum value is 512.  The
1008506f1d07SSam Ravnborg	  minimum value which makes sense is 2.
1009506f1d07SSam Ravnborg
1010aec6487eSIngo Molnar	  This is purely to save memory: each supported CPU adds about 8KB
1011aec6487eSIngo Molnar	  to the kernel image.
1012506f1d07SSam Ravnborg
101366558b73STim Chenconfig SCHED_CLUSTER
101466558b73STim Chen	bool "Cluster scheduler support"
101566558b73STim Chen	depends on SMP
101666558b73STim Chen	default y
101766558b73STim Chen	help
101866558b73STim Chen	  Cluster scheduler support improves the CPU scheduler's decision
101966558b73STim Chen	  making when dealing with machines that have clusters of CPUs.
102066558b73STim Chen	  Cluster usually means a couple of CPUs which are placed closely
102166558b73STim Chen	  by sharing mid-level caches, last-level cache tags or internal
102266558b73STim Chen	  busses.
102366558b73STim Chen
1024506f1d07SSam Ravnborgconfig SCHED_SMT
1025dbe73364SThomas Gleixner	def_bool y if SMP
1026506f1d07SSam Ravnborg
1027506f1d07SSam Ravnborgconfig SCHED_MC
10283c2362e6SHarvey Harrison	def_bool y
10293c2362e6SHarvey Harrison	prompt "Multi-core scheduler support"
1030c8e56d20SBorislav Petkov	depends on SMP
1031a7f7f624SMasahiro Yamada	help
1032506f1d07SSam Ravnborg	  Multi-core scheduler support improves the CPU scheduler's decision
1033506f1d07SSam Ravnborg	  making when dealing with multi-core CPU chips at a cost of slightly
1034506f1d07SSam Ravnborg	  increased overhead in some places. If unsure say N here.
1035506f1d07SSam Ravnborg
1036de966cf4STim Chenconfig SCHED_MC_PRIO
1037de966cf4STim Chen	bool "CPU core priorities scheduler support"
10380a21fc12SIngo Molnar	depends on SCHED_MC && CPU_SUP_INTEL
10390a21fc12SIngo Molnar	select X86_INTEL_PSTATE
10400a21fc12SIngo Molnar	select CPU_FREQ
1041de966cf4STim Chen	default y
1042a7f7f624SMasahiro Yamada	help
1043de966cf4STim Chen	  Intel Turbo Boost Max Technology 3.0 enabled CPUs have a
1044de966cf4STim Chen	  core ordering determined at manufacturing time, which allows
1045de966cf4STim Chen	  certain cores to reach higher turbo frequencies (when running
1046de966cf4STim Chen	  single threaded workloads) than others.
1047de966cf4STim Chen
1048de966cf4STim Chen	  Enabling this kernel feature teaches the scheduler about
1049de966cf4STim Chen	  the TBM3 (aka ITMT) priority order of the CPU cores and adjusts the
1050de966cf4STim Chen	  scheduler's CPU selection logic accordingly, so that higher
1051de966cf4STim Chen	  overall system performance can be achieved.
1052de966cf4STim Chen
1053de966cf4STim Chen	  This feature will have no effect on CPUs without this feature.
1054de966cf4STim Chen
1055de966cf4STim Chen	  If unsure say Y here.
10565e76b2abSTim Chen
105730b8b006SThomas Gleixnerconfig UP_LATE_INIT
105830b8b006SThomas Gleixner	def_bool y
1059ba360f88SThomas Gleixner	depends on !SMP && X86_LOCAL_APIC
106030b8b006SThomas Gleixner
1061506f1d07SSam Ravnborgconfig X86_UP_APIC
106250849eefSJan Beulich	bool "Local APIC support on uniprocessors" if !PCI_MSI
106350849eefSJan Beulich	default PCI_MSI
106438a1dfdaSBryan O'Donoghue	depends on X86_32 && !SMP && !X86_32_NON_STANDARD
1065a7f7f624SMasahiro Yamada	help
1066506f1d07SSam Ravnborg	  A local APIC (Advanced Programmable Interrupt Controller) is an
1067506f1d07SSam Ravnborg	  integrated interrupt controller in the CPU. If you have a single-CPU
1068506f1d07SSam Ravnborg	  system which has a processor with a local APIC, you can say Y here to
1069506f1d07SSam Ravnborg	  enable and use it. If you say Y here even though your machine doesn't
1070506f1d07SSam Ravnborg	  have a local APIC, then the kernel will still run with no slowdown at
1071506f1d07SSam Ravnborg	  all. The local APIC supports CPU-generated self-interrupts (timer,
1072506f1d07SSam Ravnborg	  performance counters), and the NMI watchdog which detects hard
1073506f1d07SSam Ravnborg	  lockups.
1074506f1d07SSam Ravnborg
1075506f1d07SSam Ravnborgconfig X86_UP_IOAPIC
1076506f1d07SSam Ravnborg	bool "IO-APIC support on uniprocessors"
1077506f1d07SSam Ravnborg	depends on X86_UP_APIC
1078a7f7f624SMasahiro Yamada	help
1079506f1d07SSam Ravnborg	  An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an
1080506f1d07SSam Ravnborg	  SMP-capable replacement for PC-style interrupt controllers. Most
1081506f1d07SSam Ravnborg	  SMP systems and many recent uniprocessor systems have one.
1082506f1d07SSam Ravnborg
1083506f1d07SSam Ravnborg	  If you have a single-CPU system with an IO-APIC, you can say Y here
1084506f1d07SSam Ravnborg	  to use it. If you say Y here even though your machine doesn't have
1085506f1d07SSam Ravnborg	  an IO-APIC, then the kernel will still run with no slowdown at all.
1086506f1d07SSam Ravnborg
1087506f1d07SSam Ravnborgconfig X86_LOCAL_APIC
10883c2362e6SHarvey Harrison	def_bool y
10890dbc6078SThomas Petazzoni	depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC || PCI_MSI
1090b5dc8e6cSJiang Liu	select IRQ_DOMAIN_HIERARCHY
109152f518a3SJiang Liu	select PCI_MSI_IRQ_DOMAIN if PCI_MSI
1092506f1d07SSam Ravnborg
1093506f1d07SSam Ravnborgconfig X86_IO_APIC
1094b1da1e71SJan Beulich	def_bool y
1095b1da1e71SJan Beulich	depends on X86_LOCAL_APIC || X86_UP_IOAPIC
1096506f1d07SSam Ravnborg
109741b9eb26SStefan Assmannconfig X86_REROUTE_FOR_BROKEN_BOOT_IRQS
109841b9eb26SStefan Assmann	bool "Reroute for broken boot IRQs"
109941b9eb26SStefan Assmann	depends on X86_IO_APIC
1100a7f7f624SMasahiro Yamada	help
110141b9eb26SStefan Assmann	  This option enables a workaround that fixes a source of
110241b9eb26SStefan Assmann	  spurious interrupts. This is recommended when threaded
110341b9eb26SStefan Assmann	  interrupt handling is used on systems where the generation of
110441b9eb26SStefan Assmann	  superfluous "boot interrupts" cannot be disabled.
110541b9eb26SStefan Assmann
110641b9eb26SStefan Assmann	  Some chipsets generate a legacy INTx "boot IRQ" when the IRQ
110741b9eb26SStefan Assmann	  entry in the chipset's IO-APIC is masked (as, e.g. the RT
110841b9eb26SStefan Assmann	  kernel does during interrupt handling). On chipsets where this
110941b9eb26SStefan Assmann	  boot IRQ generation cannot be disabled, this workaround keeps
111041b9eb26SStefan Assmann	  the original IRQ line masked so that only the equivalent "boot
111141b9eb26SStefan Assmann	  IRQ" is delivered to the CPUs. The workaround also tells the
111241b9eb26SStefan Assmann	  kernel to set up the IRQ handler on the boot IRQ line. In this
111341b9eb26SStefan Assmann	  way only one interrupt is delivered to the kernel. Otherwise
111441b9eb26SStefan Assmann	  the spurious second interrupt may cause the kernel to bring
111541b9eb26SStefan Assmann	  down (vital) interrupt lines.
111641b9eb26SStefan Assmann
111741b9eb26SStefan Assmann	  Only affects "broken" chipsets. Interrupt sharing may be
111841b9eb26SStefan Assmann	  increased on these systems.
111941b9eb26SStefan Assmann
1120506f1d07SSam Ravnborgconfig X86_MCE
1121bab9bc65SAndi Kleen	bool "Machine Check / overheating reporting"
1122648ed940SChen, Gong	select GENERIC_ALLOCATOR
1123e57dbaf7SBorislav Petkov	default y
1124a7f7f624SMasahiro Yamada	help
1125bab9bc65SAndi Kleen	  Machine Check support allows the processor to notify the
1126bab9bc65SAndi Kleen	  kernel if it detects a problem (e.g. overheating, data corruption).
1127506f1d07SSam Ravnborg	  The action the kernel takes depends on the severity of the problem,
1128bab9bc65SAndi Kleen	  ranging from warning messages to halting the machine.
11294efc0670SAndi Kleen
11305de97c9fSTony Luckconfig X86_MCELOG_LEGACY
11315de97c9fSTony Luck	bool "Support for deprecated /dev/mcelog character device"
11325de97c9fSTony Luck	depends on X86_MCE
1133a7f7f624SMasahiro Yamada	help
11345de97c9fSTony Luck	  Enable support for /dev/mcelog which is needed by the old mcelog
11355de97c9fSTony Luck	  userspace logging daemon. Consider switching to the new generation
11365de97c9fSTony Luck	  rasdaemon solution.
11375de97c9fSTony Luck
1138506f1d07SSam Ravnborgconfig X86_MCE_INTEL
11393c2362e6SHarvey Harrison	def_bool y
11403c2362e6SHarvey Harrison	prompt "Intel MCE features"
1141c1ebf835SAndi Kleen	depends on X86_MCE && X86_LOCAL_APIC
1142a7f7f624SMasahiro Yamada	help
1143506f1d07SSam Ravnborg	   Additional support for intel specific MCE features such as
1144506f1d07SSam Ravnborg	   the thermal monitor.
1145506f1d07SSam Ravnborg
1146506f1d07SSam Ravnborgconfig X86_MCE_AMD
11473c2362e6SHarvey Harrison	def_bool y
11483c2362e6SHarvey Harrison	prompt "AMD MCE features"
1149f5382de9SYazen Ghannam	depends on X86_MCE && X86_LOCAL_APIC && AMD_NB
1150a7f7f624SMasahiro Yamada	help
1151506f1d07SSam Ravnborg	   Additional support for AMD specific MCE features such as
1152506f1d07SSam Ravnborg	   the DRAM Error Threshold.
1153506f1d07SSam Ravnborg
11544efc0670SAndi Kleenconfig X86_ANCIENT_MCE
11556fc108a0SJan Beulich	bool "Support for old Pentium 5 / WinChip machine checks"
1156c31d9633SAndi Kleen	depends on X86_32 && X86_MCE
1157a7f7f624SMasahiro Yamada	help
11584efc0670SAndi Kleen	  Include support for machine check handling on old Pentium 5 or WinChip
11595065a706SMasanari Iida	  systems. These typically need to be enabled explicitly on the command
11604efc0670SAndi Kleen	  line.
11614efc0670SAndi Kleen
1162b2762686SAndi Kleenconfig X86_MCE_THRESHOLD
1163b2762686SAndi Kleen	depends on X86_MCE_AMD || X86_MCE_INTEL
11646fc108a0SJan Beulich	def_bool y
1165b2762686SAndi Kleen
1166ea149b36SAndi Kleenconfig X86_MCE_INJECT
1167bc8e80d5SBorislav Petkov	depends on X86_MCE && X86_LOCAL_APIC && DEBUG_FS
1168ea149b36SAndi Kleen	tristate "Machine check injector support"
1169a7f7f624SMasahiro Yamada	help
1170ea149b36SAndi Kleen	  Provide support for injecting machine checks for testing purposes.
1171ea149b36SAndi Kleen	  If you don't know what a machine check is and you don't do kernel
1172ea149b36SAndi Kleen	  QA it is safe to say n.
1173ea149b36SAndi Kleen
117407dc900eSPeter Zijlstrasource "arch/x86/events/Kconfig"
1175e633c65aSKan Liang
11765aef51c3SAndy Lutomirskiconfig X86_LEGACY_VM86
11771e642812SIngo Molnar	bool "Legacy VM86 support"
1178506f1d07SSam Ravnborg	depends on X86_32
1179a7f7f624SMasahiro Yamada	help
11805aef51c3SAndy Lutomirski	  This option allows user programs to put the CPU into V8086
11815aef51c3SAndy Lutomirski	  mode, which is an 80286-era approximation of 16-bit real mode.
11825aef51c3SAndy Lutomirski
11835aef51c3SAndy Lutomirski	  Some very old versions of X and/or vbetool require this option
11845aef51c3SAndy Lutomirski	  for user mode setting.  Similarly, DOSEMU will use it if
11855aef51c3SAndy Lutomirski	  available to accelerate real mode DOS programs.  However, any
11865aef51c3SAndy Lutomirski	  recent version of DOSEMU, X, or vbetool should be fully
11875aef51c3SAndy Lutomirski	  functional even without kernel VM86 support, as they will all
11881e642812SIngo Molnar	  fall back to software emulation. Nevertheless, if you are using
11891e642812SIngo Molnar	  a 16-bit DOS program where 16-bit performance matters, vm86
11901e642812SIngo Molnar	  mode might be faster than emulation and you might want to
11911e642812SIngo Molnar	  enable this option.
11925aef51c3SAndy Lutomirski
11931e642812SIngo Molnar	  Note that any app that works on a 64-bit kernel is unlikely to
11941e642812SIngo Molnar	  need this option, as 64-bit kernels don't, and can't, support
11951e642812SIngo Molnar	  V8086 mode. This option is also unrelated to 16-bit protected
11961e642812SIngo Molnar	  mode and is not needed to run most 16-bit programs under Wine.
11975aef51c3SAndy Lutomirski
11981e642812SIngo Molnar	  Enabling this option increases the complexity of the kernel
11991e642812SIngo Molnar	  and slows down exception handling a tiny bit.
12005aef51c3SAndy Lutomirski
12011e642812SIngo Molnar	  If unsure, say N here.
12025aef51c3SAndy Lutomirski
12035aef51c3SAndy Lutomirskiconfig VM86
12045aef51c3SAndy Lutomirski	bool
12055aef51c3SAndy Lutomirski	default X86_LEGACY_VM86
120634273f41SH. Peter Anvin
120734273f41SH. Peter Anvinconfig X86_16BIT
120834273f41SH. Peter Anvin	bool "Enable support for 16-bit segments" if EXPERT
120934273f41SH. Peter Anvin	default y
1210a5b9e5a2SAndy Lutomirski	depends on MODIFY_LDT_SYSCALL
1211a7f7f624SMasahiro Yamada	help
121234273f41SH. Peter Anvin	  This option is required by programs like Wine to run 16-bit
121334273f41SH. Peter Anvin	  protected mode legacy code on x86 processors.  Disabling
121434273f41SH. Peter Anvin	  this option saves about 300 bytes on i386, or around 6K text
121534273f41SH. Peter Anvin	  plus 16K runtime memory on x86-64,
121634273f41SH. Peter Anvin
121734273f41SH. Peter Anvinconfig X86_ESPFIX32
121834273f41SH. Peter Anvin	def_bool y
121934273f41SH. Peter Anvin	depends on X86_16BIT && X86_32
1220506f1d07SSam Ravnborg
1221197725deSH. Peter Anvinconfig X86_ESPFIX64
1222197725deSH. Peter Anvin	def_bool y
122334273f41SH. Peter Anvin	depends on X86_16BIT && X86_64
1224506f1d07SSam Ravnborg
12251ad83c85SAndy Lutomirskiconfig X86_VSYSCALL_EMULATION
12261ad83c85SAndy Lutomirski	bool "Enable vsyscall emulation" if EXPERT
12271ad83c85SAndy Lutomirski	default y
12281ad83c85SAndy Lutomirski	depends on X86_64
1229a7f7f624SMasahiro Yamada	help
12301ad83c85SAndy Lutomirski	 This enables emulation of the legacy vsyscall page.  Disabling
12311ad83c85SAndy Lutomirski	 it is roughly equivalent to booting with vsyscall=none, except
12321ad83c85SAndy Lutomirski	 that it will also disable the helpful warning if a program
12331ad83c85SAndy Lutomirski	 tries to use a vsyscall.  With this option set to N, offending
12341ad83c85SAndy Lutomirski	 programs will just segfault, citing addresses of the form
12351ad83c85SAndy Lutomirski	 0xffffffffff600?00.
12361ad83c85SAndy Lutomirski
12371ad83c85SAndy Lutomirski	 This option is required by many programs built before 2013, and
12381ad83c85SAndy Lutomirski	 care should be used even with newer programs if set to N.
12391ad83c85SAndy Lutomirski
12401ad83c85SAndy Lutomirski	 Disabling this option saves about 7K of kernel size and
12411ad83c85SAndy Lutomirski	 possibly 4K of additional runtime pagetable memory.
12421ad83c85SAndy Lutomirski
1243111e7b15SThomas Gleixnerconfig X86_IOPL_IOPERM
1244111e7b15SThomas Gleixner	bool "IOPERM and IOPL Emulation"
1245a24ca997SThomas Gleixner	default y
1246a7f7f624SMasahiro Yamada	help
1247111e7b15SThomas Gleixner	  This enables the ioperm() and iopl() syscalls which are necessary
1248111e7b15SThomas Gleixner	  for legacy applications.
1249111e7b15SThomas Gleixner
1250c8137aceSThomas Gleixner	  Legacy IOPL support is an overbroad mechanism which allows user
1251c8137aceSThomas Gleixner	  space aside of accessing all 65536 I/O ports also to disable
1252c8137aceSThomas Gleixner	  interrupts. To gain this access the caller needs CAP_SYS_RAWIO
1253c8137aceSThomas Gleixner	  capabilities and permission from potentially active security
1254c8137aceSThomas Gleixner	  modules.
1255c8137aceSThomas Gleixner
1256c8137aceSThomas Gleixner	  The emulation restricts the functionality of the syscall to
1257c8137aceSThomas Gleixner	  only allowing the full range I/O port access, but prevents the
1258a24ca997SThomas Gleixner	  ability to disable interrupts from user space which would be
1259a24ca997SThomas Gleixner	  granted if the hardware IOPL mechanism would be used.
1260c8137aceSThomas Gleixner
1261506f1d07SSam Ravnborgconfig TOSHIBA
1262506f1d07SSam Ravnborg	tristate "Toshiba Laptop support"
1263506f1d07SSam Ravnborg	depends on X86_32
1264a7f7f624SMasahiro Yamada	help
1265506f1d07SSam Ravnborg	  This adds a driver to safely access the System Management Mode of
1266506f1d07SSam Ravnborg	  the CPU on Toshiba portables with a genuine Toshiba BIOS. It does
1267506f1d07SSam Ravnborg	  not work on models with a Phoenix BIOS. The System Management Mode
1268506f1d07SSam Ravnborg	  is used to set the BIOS and power saving options on Toshiba portables.
1269506f1d07SSam Ravnborg
1270506f1d07SSam Ravnborg	  For information on utilities to make use of this driver see the
1271506f1d07SSam Ravnborg	  Toshiba Linux utilities web site at:
1272506f1d07SSam Ravnborg	  <http://www.buzzard.org.uk/toshiba/>.
1273506f1d07SSam Ravnborg
1274506f1d07SSam Ravnborg	  Say Y if you intend to run this kernel on a Toshiba portable.
1275506f1d07SSam Ravnborg	  Say N otherwise.
1276506f1d07SSam Ravnborg
1277506f1d07SSam Ravnborgconfig X86_REBOOTFIXUPS
12789ba16087SJan Beulich	bool "Enable X86 board specific fixups for reboot"
12799ba16087SJan Beulich	depends on X86_32
1280a7f7f624SMasahiro Yamada	help
1281506f1d07SSam Ravnborg	  This enables chipset and/or board specific fixups to be done
1282506f1d07SSam Ravnborg	  in order to get reboot to work correctly. This is only needed on
1283506f1d07SSam Ravnborg	  some combinations of hardware and BIOS. The symptom, for which
1284506f1d07SSam Ravnborg	  this config is intended, is when reboot ends with a stalled/hung
1285506f1d07SSam Ravnborg	  system.
1286506f1d07SSam Ravnborg
1287506f1d07SSam Ravnborg	  Currently, the only fixup is for the Geode machines using
12885e3a77e9SFlorian Fainelli	  CS5530A and CS5536 chipsets and the RDC R-321x SoC.
1289506f1d07SSam Ravnborg
1290506f1d07SSam Ravnborg	  Say Y if you want to enable the fixup. Currently, it's safe to
1291506f1d07SSam Ravnborg	  enable this option even if you don't need it.
1292506f1d07SSam Ravnborg	  Say N otherwise.
1293506f1d07SSam Ravnborg
1294506f1d07SSam Ravnborgconfig MICROCODE
12959a2bc335SBorislav Petkov	bool "CPU microcode loading support"
12969a2bc335SBorislav Petkov	default y
129780030e3dSBorislav Petkov	depends on CPU_SUP_AMD || CPU_SUP_INTEL
1298a7f7f624SMasahiro Yamada	help
1299506f1d07SSam Ravnborg	  If you say Y here, you will be able to update the microcode on
13005f9c01aaSBorislav Petkov	  Intel and AMD processors. The Intel support is for the IA32 family,
13015f9c01aaSBorislav Petkov	  e.g. Pentium Pro, Pentium II, Pentium III, Pentium 4, Xeon etc. The
13025f9c01aaSBorislav Petkov	  AMD support is for families 0x10 and later. You will obviously need
13035f9c01aaSBorislav Petkov	  the actual microcode binary data itself which is not shipped with
13045f9c01aaSBorislav Petkov	  the Linux kernel.
1305506f1d07SSam Ravnborg
13065f9c01aaSBorislav Petkov	  The preferred method to load microcode from a detached initrd is described
1307cb1aaebeSMauro Carvalho Chehab	  in Documentation/x86/microcode.rst. For that you need to enable
13085f9c01aaSBorislav Petkov	  CONFIG_BLK_DEV_INITRD in order for the loader to be able to scan the
13095f9c01aaSBorislav Petkov	  initrd for microcode blobs.
1310506f1d07SSam Ravnborg
1311c508c46eSBenjamin Gilbert	  In addition, you can build the microcode into the kernel. For that you
1312c508c46eSBenjamin Gilbert	  need to add the vendor-supplied microcode to the CONFIG_EXTRA_FIRMWARE
1313c508c46eSBenjamin Gilbert	  config option.
1314506f1d07SSam Ravnborg
13158d86f390SPeter Orubaconfig MICROCODE_INTEL
1316e43f6e67SBorislav Petkov	bool "Intel microcode loading support"
13178d86f390SPeter Oruba	depends on MICROCODE
13188d86f390SPeter Oruba	default MICROCODE
1319a7f7f624SMasahiro Yamada	help
13208d86f390SPeter Oruba	  This options enables microcode patch loading support for Intel
13218d86f390SPeter Oruba	  processors.
13228d86f390SPeter Oruba
1323b8989db9SAlan	  For the current Intel microcode data package go to
1324b8989db9SAlan	  <https://downloadcenter.intel.com> and search for
1325b8989db9SAlan	  'Linux Processor Microcode Data File'.
13268d86f390SPeter Oruba
132780cc9f10SPeter Orubaconfig MICROCODE_AMD
1328e43f6e67SBorislav Petkov	bool "AMD microcode loading support"
132980cc9f10SPeter Oruba	depends on MICROCODE
1330a7f7f624SMasahiro Yamada	help
133180cc9f10SPeter Oruba	  If you select this option, microcode patch loading support for AMD
133280cc9f10SPeter Oruba	  processors will be enabled.
133380cc9f10SPeter Oruba
1334506f1d07SSam Ravnborgconfig MICROCODE_OLD_INTERFACE
1335c02f48e0SBorislav Petkov	bool "Ancient loading interface (DEPRECATED)"
1336c02f48e0SBorislav Petkov	default n
1337506f1d07SSam Ravnborg	depends on MICROCODE
1338a7f7f624SMasahiro Yamada	help
1339c02f48e0SBorislav Petkov	  DO NOT USE THIS! This is the ancient /dev/cpu/microcode interface
1340c02f48e0SBorislav Petkov	  which was used by userspace tools like iucode_tool and microcode.ctl.
1341c02f48e0SBorislav Petkov	  It is inadequate because it runs too late to be able to properly
1342c02f48e0SBorislav Petkov	  load microcode on a machine and it needs special tools. Instead, you
1343c02f48e0SBorislav Petkov	  should've switched to the early loading method with the initrd or
1344cb1aaebeSMauro Carvalho Chehab	  builtin microcode by now: Documentation/x86/microcode.rst
1345506f1d07SSam Ravnborg
1346506f1d07SSam Ravnborgconfig X86_MSR
1347506f1d07SSam Ravnborg	tristate "/dev/cpu/*/msr - Model-specific register support"
1348a7f7f624SMasahiro Yamada	help
1349506f1d07SSam Ravnborg	  This device gives privileged processes access to the x86
1350506f1d07SSam Ravnborg	  Model-Specific Registers (MSRs).  It is a character device with
1351506f1d07SSam Ravnborg	  major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr.
1352506f1d07SSam Ravnborg	  MSR accesses are directed to a specific CPU on multi-processor
1353506f1d07SSam Ravnborg	  systems.
1354506f1d07SSam Ravnborg
1355506f1d07SSam Ravnborgconfig X86_CPUID
1356506f1d07SSam Ravnborg	tristate "/dev/cpu/*/cpuid - CPU information support"
1357a7f7f624SMasahiro Yamada	help
1358506f1d07SSam Ravnborg	  This device gives processes access to the x86 CPUID instruction to
1359506f1d07SSam Ravnborg	  be executed on a specific processor.  It is a character device
1360506f1d07SSam Ravnborg	  with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to
1361506f1d07SSam Ravnborg	  /dev/cpu/31/cpuid.
1362506f1d07SSam Ravnborg
1363506f1d07SSam Ravnborgchoice
1364506f1d07SSam Ravnborg	prompt "High Memory Support"
13656fc108a0SJan Beulich	default HIGHMEM4G
1366506f1d07SSam Ravnborg	depends on X86_32
1367506f1d07SSam Ravnborg
1368506f1d07SSam Ravnborgconfig NOHIGHMEM
1369506f1d07SSam Ravnborg	bool "off"
1370a7f7f624SMasahiro Yamada	help
1371506f1d07SSam Ravnborg	  Linux can use up to 64 Gigabytes of physical memory on x86 systems.
1372506f1d07SSam Ravnborg	  However, the address space of 32-bit x86 processors is only 4
1373506f1d07SSam Ravnborg	  Gigabytes large. That means that, if you have a large amount of
1374506f1d07SSam Ravnborg	  physical memory, not all of it can be "permanently mapped" by the
1375506f1d07SSam Ravnborg	  kernel. The physical memory that's not permanently mapped is called
1376506f1d07SSam Ravnborg	  "high memory".
1377506f1d07SSam Ravnborg
1378506f1d07SSam Ravnborg	  If you are compiling a kernel which will never run on a machine with
1379506f1d07SSam Ravnborg	  more than 1 Gigabyte total physical RAM, answer "off" here (default
1380506f1d07SSam Ravnborg	  choice and suitable for most users). This will result in a "3GB/1GB"
1381506f1d07SSam Ravnborg	  split: 3GB are mapped so that each process sees a 3GB virtual memory
1382506f1d07SSam Ravnborg	  space and the remaining part of the 4GB virtual memory space is used
1383506f1d07SSam Ravnborg	  by the kernel to permanently map as much physical memory as
1384506f1d07SSam Ravnborg	  possible.
1385506f1d07SSam Ravnborg
1386506f1d07SSam Ravnborg	  If the machine has between 1 and 4 Gigabytes physical RAM, then
1387506f1d07SSam Ravnborg	  answer "4GB" here.
1388506f1d07SSam Ravnborg
1389506f1d07SSam Ravnborg	  If more than 4 Gigabytes is used then answer "64GB" here. This
1390506f1d07SSam Ravnborg	  selection turns Intel PAE (Physical Address Extension) mode on.
1391506f1d07SSam Ravnborg	  PAE implements 3-level paging on IA32 processors. PAE is fully
1392506f1d07SSam Ravnborg	  supported by Linux, PAE mode is implemented on all recent Intel
1393506f1d07SSam Ravnborg	  processors (Pentium Pro and better). NOTE: If you say "64GB" here,
1394506f1d07SSam Ravnborg	  then the kernel will not boot on CPUs that don't support PAE!
1395506f1d07SSam Ravnborg
1396506f1d07SSam Ravnborg	  The actual amount of total physical memory will either be
1397506f1d07SSam Ravnborg	  auto detected or can be forced by using a kernel command line option
1398506f1d07SSam Ravnborg	  such as "mem=256M". (Try "man bootparam" or see the documentation of
1399506f1d07SSam Ravnborg	  your boot loader (lilo or loadlin) about how to pass options to the
1400506f1d07SSam Ravnborg	  kernel at boot time.)
1401506f1d07SSam Ravnborg
1402506f1d07SSam Ravnborg	  If unsure, say "off".
1403506f1d07SSam Ravnborg
1404506f1d07SSam Ravnborgconfig HIGHMEM4G
1405506f1d07SSam Ravnborg	bool "4GB"
1406a7f7f624SMasahiro Yamada	help
1407506f1d07SSam Ravnborg	  Select this if you have a 32-bit processor and between 1 and 4
1408506f1d07SSam Ravnborg	  gigabytes of physical RAM.
1409506f1d07SSam Ravnborg
1410506f1d07SSam Ravnborgconfig HIGHMEM64G
1411506f1d07SSam Ravnborg	bool "64GB"
1412225bac2dSLukas Bulwahn	depends on !M486SX && !M486 && !M586 && !M586TSC && !M586MMX && !MGEODE_LX && !MGEODEGX1 && !MCYRIXIII && !MELAN && !MWINCHIPC6 && !MWINCHIP3D && !MK6
1413506f1d07SSam Ravnborg	select X86_PAE
1414a7f7f624SMasahiro Yamada	help
1415506f1d07SSam Ravnborg	  Select this if you have a 32-bit processor and more than 4
1416506f1d07SSam Ravnborg	  gigabytes of physical RAM.
1417506f1d07SSam Ravnborg
1418506f1d07SSam Ravnborgendchoice
1419506f1d07SSam Ravnborg
1420506f1d07SSam Ravnborgchoice
14216a108a14SDavid Rientjes	prompt "Memory split" if EXPERT
1422506f1d07SSam Ravnborg	default VMSPLIT_3G
1423506f1d07SSam Ravnborg	depends on X86_32
1424a7f7f624SMasahiro Yamada	help
1425506f1d07SSam Ravnborg	  Select the desired split between kernel and user memory.
1426506f1d07SSam Ravnborg
1427506f1d07SSam Ravnborg	  If the address range available to the kernel is less than the
1428506f1d07SSam Ravnborg	  physical memory installed, the remaining memory will be available
1429506f1d07SSam Ravnborg	  as "high memory". Accessing high memory is a little more costly
1430506f1d07SSam Ravnborg	  than low memory, as it needs to be mapped into the kernel first.
1431506f1d07SSam Ravnborg	  Note that increasing the kernel address space limits the range
1432506f1d07SSam Ravnborg	  available to user programs, making the address space there
1433506f1d07SSam Ravnborg	  tighter.  Selecting anything other than the default 3G/1G split
1434506f1d07SSam Ravnborg	  will also likely make your kernel incompatible with binary-only
1435506f1d07SSam Ravnborg	  kernel modules.
1436506f1d07SSam Ravnborg
1437506f1d07SSam Ravnborg	  If you are not absolutely sure what you are doing, leave this
1438506f1d07SSam Ravnborg	  option alone!
1439506f1d07SSam Ravnborg
1440506f1d07SSam Ravnborg	config VMSPLIT_3G
1441506f1d07SSam Ravnborg		bool "3G/1G user/kernel split"
1442506f1d07SSam Ravnborg	config VMSPLIT_3G_OPT
1443506f1d07SSam Ravnborg		depends on !X86_PAE
1444506f1d07SSam Ravnborg		bool "3G/1G user/kernel split (for full 1G low memory)"
1445506f1d07SSam Ravnborg	config VMSPLIT_2G
1446506f1d07SSam Ravnborg		bool "2G/2G user/kernel split"
1447506f1d07SSam Ravnborg	config VMSPLIT_2G_OPT
1448506f1d07SSam Ravnborg		depends on !X86_PAE
1449506f1d07SSam Ravnborg		bool "2G/2G user/kernel split (for full 2G low memory)"
1450506f1d07SSam Ravnborg	config VMSPLIT_1G
1451506f1d07SSam Ravnborg		bool "1G/3G user/kernel split"
1452506f1d07SSam Ravnborgendchoice
1453506f1d07SSam Ravnborg
1454506f1d07SSam Ravnborgconfig PAGE_OFFSET
1455506f1d07SSam Ravnborg	hex
1456506f1d07SSam Ravnborg	default 0xB0000000 if VMSPLIT_3G_OPT
1457506f1d07SSam Ravnborg	default 0x80000000 if VMSPLIT_2G
1458506f1d07SSam Ravnborg	default 0x78000000 if VMSPLIT_2G_OPT
1459506f1d07SSam Ravnborg	default 0x40000000 if VMSPLIT_1G
1460506f1d07SSam Ravnborg	default 0xC0000000
1461506f1d07SSam Ravnborg	depends on X86_32
1462506f1d07SSam Ravnborg
1463506f1d07SSam Ravnborgconfig HIGHMEM
14643c2362e6SHarvey Harrison	def_bool y
1465506f1d07SSam Ravnborg	depends on X86_32 && (HIGHMEM64G || HIGHMEM4G)
1466506f1d07SSam Ravnborg
1467506f1d07SSam Ravnborgconfig X86_PAE
14689ba16087SJan Beulich	bool "PAE (Physical Address Extension) Support"
1469506f1d07SSam Ravnborg	depends on X86_32 && !HIGHMEM4G
1470d4a451d5SChristoph Hellwig	select PHYS_ADDR_T_64BIT
14719d99c712SChristian Melki	select SWIOTLB
1472a7f7f624SMasahiro Yamada	help
1473506f1d07SSam Ravnborg	  PAE is required for NX support, and furthermore enables
1474506f1d07SSam Ravnborg	  larger swapspace support for non-overcommit purposes. It
1475506f1d07SSam Ravnborg	  has the cost of more pagetable lookup overhead, and also
1476506f1d07SSam Ravnborg	  consumes more pagetable space per process.
1477506f1d07SSam Ravnborg
147877ef56e4SKirill A. Shutemovconfig X86_5LEVEL
147977ef56e4SKirill A. Shutemov	bool "Enable 5-level page tables support"
148018ec1eafSKirill A. Shutemov	default y
1481eedb92abSKirill A. Shutemov	select DYNAMIC_MEMORY_LAYOUT
1482162434e7SKirill A. Shutemov	select SPARSEMEM_VMEMMAP
148377ef56e4SKirill A. Shutemov	depends on X86_64
1484a7f7f624SMasahiro Yamada	help
148577ef56e4SKirill A. Shutemov	  5-level paging enables access to larger address space:
148677ef56e4SKirill A. Shutemov	  upto 128 PiB of virtual address space and 4 PiB of
148777ef56e4SKirill A. Shutemov	  physical address space.
148877ef56e4SKirill A. Shutemov
148977ef56e4SKirill A. Shutemov	  It will be supported by future Intel CPUs.
149077ef56e4SKirill A. Shutemov
14916657fca0SKirill A. Shutemov	  A kernel with the option enabled can be booted on machines that
14926657fca0SKirill A. Shutemov	  support 4- or 5-level paging.
149377ef56e4SKirill A. Shutemov
1494cb1aaebeSMauro Carvalho Chehab	  See Documentation/x86/x86_64/5level-paging.rst for more
149577ef56e4SKirill A. Shutemov	  information.
149677ef56e4SKirill A. Shutemov
149777ef56e4SKirill A. Shutemov	  Say N if unsure.
149877ef56e4SKirill A. Shutemov
149910971ab2SIngo Molnarconfig X86_DIRECT_GBPAGES
1500e5008abeSLuis R. Rodriguez	def_bool y
15012e1da13fSVlastimil Babka	depends on X86_64
1502a7f7f624SMasahiro Yamada	help
150310971ab2SIngo Molnar	  Certain kernel features effectively disable kernel
150410971ab2SIngo Molnar	  linear 1 GB mappings (even if the CPU otherwise
150510971ab2SIngo Molnar	  supports them), so don't confuse the user by printing
150610971ab2SIngo Molnar	  that we have them enabled.
15079e899816SNick Piggin
15085c280cf6SThomas Gleixnerconfig X86_CPA_STATISTICS
15095c280cf6SThomas Gleixner	bool "Enable statistic for Change Page Attribute"
15105c280cf6SThomas Gleixner	depends on DEBUG_FS
1511a7f7f624SMasahiro Yamada	help
1512b75baaf3SIngo Molnar	  Expose statistics about the Change Page Attribute mechanism, which
1513a943245aSColin Ian King	  helps to determine the effectiveness of preserving large and huge
15145c280cf6SThomas Gleixner	  page mappings when mapping protections are changed.
15155c280cf6SThomas Gleixner
151620f07a04SKirill A. Shutemovconfig X86_MEM_ENCRYPT
151720f07a04SKirill A. Shutemov	select ARCH_HAS_FORCE_DMA_UNENCRYPTED
151820f07a04SKirill A. Shutemov	select DYNAMIC_PHYSICAL_MASK
151920f07a04SKirill A. Shutemov	select ARCH_HAS_RESTRICTED_VIRTIO_MEMORY_ACCESS
152020f07a04SKirill A. Shutemov	def_bool n
152120f07a04SKirill A. Shutemov
15227744ccdbSTom Lendackyconfig AMD_MEM_ENCRYPT
15237744ccdbSTom Lendacky	bool "AMD Secure Memory Encryption (SME) support"
15247744ccdbSTom Lendacky	depends on X86_64 && CPU_SUP_AMD
152582fef0adSDavid Rientjes	select DMA_COHERENT_POOL
1526ce9084baSArd Biesheuvel	select ARCH_USE_MEMREMAP_PROT
1527597cfe48SJoerg Roedel	select INSTRUCTION_DECODER
1528aa5a4611STom Lendacky	select ARCH_HAS_CC_PLATFORM
152920f07a04SKirill A. Shutemov	select X86_MEM_ENCRYPT
1530a7f7f624SMasahiro Yamada	help
15317744ccdbSTom Lendacky	  Say yes to enable support for the encryption of system memory.
15327744ccdbSTom Lendacky	  This requires an AMD processor that supports Secure Memory
15337744ccdbSTom Lendacky	  Encryption (SME).
15347744ccdbSTom Lendacky
15357744ccdbSTom Lendackyconfig AMD_MEM_ENCRYPT_ACTIVE_BY_DEFAULT
15367744ccdbSTom Lendacky	bool "Activate AMD Secure Memory Encryption (SME) by default"
15377744ccdbSTom Lendacky	depends on AMD_MEM_ENCRYPT
1538a7f7f624SMasahiro Yamada	help
15397744ccdbSTom Lendacky	  Say yes to have system memory encrypted by default if running on
15407744ccdbSTom Lendacky	  an AMD processor that supports Secure Memory Encryption (SME).
15417744ccdbSTom Lendacky
15427744ccdbSTom Lendacky	  If set to Y, then the encryption of system memory can be
15437744ccdbSTom Lendacky	  deactivated with the mem_encrypt=off command line option.
15447744ccdbSTom Lendacky
15457744ccdbSTom Lendacky	  If set to N, then the encryption of system memory can be
15467744ccdbSTom Lendacky	  activated with the mem_encrypt=on command line option.
15477744ccdbSTom Lendacky
1548506f1d07SSam Ravnborg# Common NUMA Features
1549506f1d07SSam Ravnborgconfig NUMA
1550e133f6eaSRandy Dunlap	bool "NUMA Memory Allocation and Scheduler Support"
1551506f1d07SSam Ravnborg	depends on SMP
1552b5660ba7SH. Peter Anvin	depends on X86_64 || (X86_32 && HIGHMEM64G && X86_BIGSMP)
1553b5660ba7SH. Peter Anvin	default y if X86_BIGSMP
15547ecd19cfSKefeng Wang	select USE_PERCPU_NUMA_NODE_ID
1555a7f7f624SMasahiro Yamada	help
1556e133f6eaSRandy Dunlap	  Enable NUMA (Non-Uniform Memory Access) support.
1557fd51b2d7SKOSAKI Motohiro
1558506f1d07SSam Ravnborg	  The kernel will try to allocate memory used by a CPU on the
1559506f1d07SSam Ravnborg	  local memory controller of the CPU and add some more
1560506f1d07SSam Ravnborg	  NUMA awareness to the kernel.
1561506f1d07SSam Ravnborg
1562c280ea5eSIngo Molnar	  For 64-bit this is recommended if the system is Intel Core i7
1563fd51b2d7SKOSAKI Motohiro	  (or later), AMD Opteron, or EM64T NUMA.
1564fd51b2d7SKOSAKI Motohiro
1565b5660ba7SH. Peter Anvin	  For 32-bit this is only needed if you boot a 32-bit
15667cf6c945SDavid Rientjes	  kernel on a 64-bit NUMA platform.
1567fd51b2d7SKOSAKI Motohiro
1568fd51b2d7SKOSAKI Motohiro	  Otherwise, you should say N.
1569506f1d07SSam Ravnborg
1570eec1d4faSHans Rosenfeldconfig AMD_NUMA
15713c2362e6SHarvey Harrison	def_bool y
15723c2362e6SHarvey Harrison	prompt "Old style AMD Opteron NUMA detection"
15735da0ef9aSTejun Heo	depends on X86_64 && NUMA && PCI
1574a7f7f624SMasahiro Yamada	help
1575eec1d4faSHans Rosenfeld	  Enable AMD NUMA node topology detection.  You should say Y here if
1576eec1d4faSHans Rosenfeld	  you have a multi processor AMD system. This uses an old method to
1577eec1d4faSHans Rosenfeld	  read the NUMA configuration directly from the builtin Northbridge
1578eec1d4faSHans Rosenfeld	  of Opteron. It is recommended to use X86_64_ACPI_NUMA instead,
1579eec1d4faSHans Rosenfeld	  which also takes priority if both are compiled in.
1580506f1d07SSam Ravnborg
1581506f1d07SSam Ravnborgconfig X86_64_ACPI_NUMA
15823c2362e6SHarvey Harrison	def_bool y
15833c2362e6SHarvey Harrison	prompt "ACPI NUMA detection"
1584506f1d07SSam Ravnborg	depends on X86_64 && NUMA && ACPI && PCI
1585506f1d07SSam Ravnborg	select ACPI_NUMA
1586a7f7f624SMasahiro Yamada	help
1587506f1d07SSam Ravnborg	  Enable ACPI SRAT based node topology detection.
1588506f1d07SSam Ravnborg
1589506f1d07SSam Ravnborgconfig NUMA_EMU
1590506f1d07SSam Ravnborg	bool "NUMA emulation"
15911b7e03efSTejun Heo	depends on NUMA
1592a7f7f624SMasahiro Yamada	help
1593506f1d07SSam Ravnborg	  Enable NUMA emulation. A flat machine will be split
1594506f1d07SSam Ravnborg	  into virtual nodes when booted with "numa=fake=N", where N is the
1595506f1d07SSam Ravnborg	  number of nodes. This is only useful for debugging.
1596506f1d07SSam Ravnborg
1597506f1d07SSam Ravnborgconfig NODES_SHIFT
1598d25e26b6SLinus Torvalds	int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP
159951591e31SDavid Rientjes	range 1 10
160051591e31SDavid Rientjes	default "10" if MAXSMP
1601506f1d07SSam Ravnborg	default "6" if X86_64
1602506f1d07SSam Ravnborg	default "3"
1603a9ee6cf5SMike Rapoport	depends on NUMA
1604a7f7f624SMasahiro Yamada	help
16051184dc2fSMike Travis	  Specify the maximum number of NUMA Nodes available on the target
1606692105b8SMatt LaPlante	  system.  Increases memory reserved to accommodate various tables.
1607506f1d07SSam Ravnborg
1608506f1d07SSam Ravnborgconfig ARCH_FLATMEM_ENABLE
1609506f1d07SSam Ravnborg	def_bool y
16103b16651fSTejun Heo	depends on X86_32 && !NUMA
1611506f1d07SSam Ravnborg
1612506f1d07SSam Ravnborgconfig ARCH_SPARSEMEM_ENABLE
1613506f1d07SSam Ravnborg	def_bool y
16146ea30386SKees Cook	depends on X86_64 || NUMA || X86_32 || X86_32_NON_STANDARD
1615506f1d07SSam Ravnborg	select SPARSEMEM_STATIC if X86_32
1616506f1d07SSam Ravnborg	select SPARSEMEM_VMEMMAP_ENABLE if X86_64
1617506f1d07SSam Ravnborg
16183b16651fSTejun Heoconfig ARCH_SPARSEMEM_DEFAULT
16196ad57f7fSMike Rapoport	def_bool X86_64 || (NUMA && X86_32)
16203b16651fSTejun Heo
1621506f1d07SSam Ravnborgconfig ARCH_SELECT_MEMORY_MODEL
1622506f1d07SSam Ravnborg	def_bool y
16234eda2bc3SDavid Hildenbrand	depends on ARCH_SPARSEMEM_ENABLE && ARCH_FLATMEM_ENABLE
1624506f1d07SSam Ravnborg
1625506f1d07SSam Ravnborgconfig ARCH_MEMORY_PROBE
1626a0842b70SToshi Kani	bool "Enable sysfs memory/probe interface"
16275c11f00bSDavid Hildenbrand	depends on MEMORY_HOTPLUG
1628a0842b70SToshi Kani	help
1629a0842b70SToshi Kani	  This option enables a sysfs memory/probe interface for testing.
1630cb1aaebeSMauro Carvalho Chehab	  See Documentation/admin-guide/mm/memory-hotplug.rst for more information.
1631a0842b70SToshi Kani	  If you are unsure how to answer this question, answer N.
1632506f1d07SSam Ravnborg
16333b16651fSTejun Heoconfig ARCH_PROC_KCORE_TEXT
16343b16651fSTejun Heo	def_bool y
16353b16651fSTejun Heo	depends on X86_64 && PROC_KCORE
16363b16651fSTejun Heo
1637a29815a3SAvi Kivityconfig ILLEGAL_POINTER_VALUE
1638a29815a3SAvi Kivity	hex
1639a29815a3SAvi Kivity	default 0 if X86_32
1640a29815a3SAvi Kivity	default 0xdead000000000000 if X86_64
1641a29815a3SAvi Kivity
16427a67832cSDan Williamsconfig X86_PMEM_LEGACY_DEVICE
16437a67832cSDan Williams	bool
16447a67832cSDan Williams
1645ec776ef6SChristoph Hellwigconfig X86_PMEM_LEGACY
16467a67832cSDan Williams	tristate "Support non-standard NVDIMMs and ADR protected memory"
16479f53f9faSDan Williams	depends on PHYS_ADDR_T_64BIT
16489f53f9faSDan Williams	depends on BLK_DEV
16497a67832cSDan Williams	select X86_PMEM_LEGACY_DEVICE
16507b27a862SDan Williams	select NUMA_KEEP_MEMINFO if NUMA
16519f53f9faSDan Williams	select LIBNVDIMM
1652ec776ef6SChristoph Hellwig	help
1653ec776ef6SChristoph Hellwig	  Treat memory marked using the non-standard e820 type of 12 as used
1654ec776ef6SChristoph Hellwig	  by the Intel Sandy Bridge-EP reference BIOS as protected memory.
1655ec776ef6SChristoph Hellwig	  The kernel will offer these regions to the 'pmem' driver so
1656ec776ef6SChristoph Hellwig	  they can be used for persistent storage.
1657ec776ef6SChristoph Hellwig
1658ec776ef6SChristoph Hellwig	  Say Y if unsure.
1659ec776ef6SChristoph Hellwig
1660506f1d07SSam Ravnborgconfig HIGHPTE
1661506f1d07SSam Ravnborg	bool "Allocate 3rd-level pagetables from highmem"
16626fc108a0SJan Beulich	depends on HIGHMEM
1663a7f7f624SMasahiro Yamada	help
1664506f1d07SSam Ravnborg	  The VM uses one page table entry for each page of physical memory.
1665506f1d07SSam Ravnborg	  For systems with a lot of RAM, this can be wasteful of precious
1666506f1d07SSam Ravnborg	  low memory.  Setting this option will put user-space page table
1667506f1d07SSam Ravnborg	  entries in high memory.
1668506f1d07SSam Ravnborg
16699f077871SJeremy Fitzhardingeconfig X86_CHECK_BIOS_CORRUPTION
16709f077871SJeremy Fitzhardinge	bool "Check for low memory corruption"
1671a7f7f624SMasahiro Yamada	help
16729f077871SJeremy Fitzhardinge	  Periodically check for memory corruption in low memory, which
16739f077871SJeremy Fitzhardinge	  is suspected to be caused by BIOS.  Even when enabled in the
16749f077871SJeremy Fitzhardinge	  configuration, it is disabled at runtime.  Enable it by
16759f077871SJeremy Fitzhardinge	  setting "memory_corruption_check=1" on the kernel command
16769f077871SJeremy Fitzhardinge	  line.  By default it scans the low 64k of memory every 60
16779f077871SJeremy Fitzhardinge	  seconds; see the memory_corruption_check_size and
16789f077871SJeremy Fitzhardinge	  memory_corruption_check_period parameters in
16798c27ceffSMauro Carvalho Chehab	  Documentation/admin-guide/kernel-parameters.rst to adjust this.
16809f077871SJeremy Fitzhardinge
16819f077871SJeremy Fitzhardinge	  When enabled with the default parameters, this option has
16829f077871SJeremy Fitzhardinge	  almost no overhead, as it reserves a relatively small amount
16839f077871SJeremy Fitzhardinge	  of memory and scans it infrequently.  It both detects corruption
16849f077871SJeremy Fitzhardinge	  and prevents it from affecting the running system.
16859f077871SJeremy Fitzhardinge
16869f077871SJeremy Fitzhardinge	  It is, however, intended as a diagnostic tool; if repeatable
16879f077871SJeremy Fitzhardinge	  BIOS-originated corruption always affects the same memory,
16889f077871SJeremy Fitzhardinge	  you can use memmap= to prevent the kernel from using that
16899f077871SJeremy Fitzhardinge	  memory.
16909f077871SJeremy Fitzhardinge
1691c885df50SJeremy Fitzhardingeconfig X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK
1692c885df50SJeremy Fitzhardinge	bool "Set the default setting of memory_corruption_check"
1693c885df50SJeremy Fitzhardinge	depends on X86_CHECK_BIOS_CORRUPTION
1694c885df50SJeremy Fitzhardinge	default y
1695a7f7f624SMasahiro Yamada	help
1696c885df50SJeremy Fitzhardinge	  Set whether the default state of memory_corruption_check is
1697c885df50SJeremy Fitzhardinge	  on or off.
1698c885df50SJeremy Fitzhardinge
1699506f1d07SSam Ravnborgconfig MATH_EMULATION
1700506f1d07SSam Ravnborg	bool
1701a5b9e5a2SAndy Lutomirski	depends on MODIFY_LDT_SYSCALL
170287d6021bSArnd Bergmann	prompt "Math emulation" if X86_32 && (M486SX || MELAN)
1703a7f7f624SMasahiro Yamada	help
1704506f1d07SSam Ravnborg	  Linux can emulate a math coprocessor (used for floating point
1705506f1d07SSam Ravnborg	  operations) if you don't have one. 486DX and Pentium processors have
1706506f1d07SSam Ravnborg	  a math coprocessor built in, 486SX and 386 do not, unless you added
1707506f1d07SSam Ravnborg	  a 487DX or 387, respectively. (The messages during boot time can
1708506f1d07SSam Ravnborg	  give you some hints here ["man dmesg"].) Everyone needs either a
1709506f1d07SSam Ravnborg	  coprocessor or this emulation.
1710506f1d07SSam Ravnborg
1711506f1d07SSam Ravnborg	  If you don't have a math coprocessor, you need to say Y here; if you
1712506f1d07SSam Ravnborg	  say Y here even though you have a coprocessor, the coprocessor will
1713506f1d07SSam Ravnborg	  be used nevertheless. (This behavior can be changed with the kernel
1714506f1d07SSam Ravnborg	  command line option "no387", which comes handy if your coprocessor
1715506f1d07SSam Ravnborg	  is broken. Try "man bootparam" or see the documentation of your boot
1716506f1d07SSam Ravnborg	  loader (lilo or loadlin) about how to pass options to the kernel at
1717506f1d07SSam Ravnborg	  boot time.) This means that it is a good idea to say Y here if you
1718506f1d07SSam Ravnborg	  intend to use this kernel on different machines.
1719506f1d07SSam Ravnborg
1720506f1d07SSam Ravnborg	  More information about the internals of the Linux math coprocessor
1721506f1d07SSam Ravnborg	  emulation can be found in <file:arch/x86/math-emu/README>.
1722506f1d07SSam Ravnborg
1723506f1d07SSam Ravnborg	  If you are not sure, say Y; apart from resulting in a 66 KB bigger
1724506f1d07SSam Ravnborg	  kernel, it won't hurt.
1725506f1d07SSam Ravnborg
1726506f1d07SSam Ravnborgconfig MTRR
17276fc108a0SJan Beulich	def_bool y
17286a108a14SDavid Rientjes	prompt "MTRR (Memory Type Range Register) support" if EXPERT
1729a7f7f624SMasahiro Yamada	help
1730506f1d07SSam Ravnborg	  On Intel P6 family processors (Pentium Pro, Pentium II and later)
1731506f1d07SSam Ravnborg	  the Memory Type Range Registers (MTRRs) may be used to control
1732506f1d07SSam Ravnborg	  processor access to memory ranges. This is most useful if you have
1733506f1d07SSam Ravnborg	  a video (VGA) card on a PCI or AGP bus. Enabling write-combining
1734506f1d07SSam Ravnborg	  allows bus write transfers to be combined into a larger transfer
1735506f1d07SSam Ravnborg	  before bursting over the PCI/AGP bus. This can increase performance
1736506f1d07SSam Ravnborg	  of image write operations 2.5 times or more. Saying Y here creates a
1737506f1d07SSam Ravnborg	  /proc/mtrr file which may be used to manipulate your processor's
1738506f1d07SSam Ravnborg	  MTRRs. Typically the X server should use this.
1739506f1d07SSam Ravnborg
1740506f1d07SSam Ravnborg	  This code has a reasonably generic interface so that similar
1741506f1d07SSam Ravnborg	  control registers on other processors can be easily supported
1742506f1d07SSam Ravnborg	  as well:
1743506f1d07SSam Ravnborg
1744506f1d07SSam Ravnborg	  The Cyrix 6x86, 6x86MX and M II processors have Address Range
1745506f1d07SSam Ravnborg	  Registers (ARRs) which provide a similar functionality to MTRRs. For
1746506f1d07SSam Ravnborg	  these, the ARRs are used to emulate the MTRRs.
1747506f1d07SSam Ravnborg	  The AMD K6-2 (stepping 8 and above) and K6-3 processors have two
1748506f1d07SSam Ravnborg	  MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing
1749506f1d07SSam Ravnborg	  write-combining. All of these processors are supported by this code
1750506f1d07SSam Ravnborg	  and it makes sense to say Y here if you have one of them.
1751506f1d07SSam Ravnborg
1752506f1d07SSam Ravnborg	  Saying Y here also fixes a problem with buggy SMP BIOSes which only
1753506f1d07SSam Ravnborg	  set the MTRRs for the boot CPU and not for the secondary CPUs. This
1754506f1d07SSam Ravnborg	  can lead to all sorts of problems, so it's good to say Y here.
1755506f1d07SSam Ravnborg
1756506f1d07SSam Ravnborg	  You can safely say Y even if your machine doesn't have MTRRs, you'll
1757506f1d07SSam Ravnborg	  just add about 9 KB to your kernel.
1758506f1d07SSam Ravnborg
1759cb1aaebeSMauro Carvalho Chehab	  See <file:Documentation/x86/mtrr.rst> for more information.
1760506f1d07SSam Ravnborg
176195ffa243SYinghai Luconfig MTRR_SANITIZER
17622ffb3501SYinghai Lu	def_bool y
176395ffa243SYinghai Lu	prompt "MTRR cleanup support"
176495ffa243SYinghai Lu	depends on MTRR
1765a7f7f624SMasahiro Yamada	help
1766aba3728cSThomas Gleixner	  Convert MTRR layout from continuous to discrete, so X drivers can
1767aba3728cSThomas Gleixner	  add writeback entries.
176895ffa243SYinghai Lu
1769aba3728cSThomas Gleixner	  Can be disabled with disable_mtrr_cleanup on the kernel command line.
1770692105b8SMatt LaPlante	  The largest mtrr entry size for a continuous block can be set with
1771aba3728cSThomas Gleixner	  mtrr_chunk_size.
177295ffa243SYinghai Lu
17732ffb3501SYinghai Lu	  If unsure, say Y.
177495ffa243SYinghai Lu
177595ffa243SYinghai Luconfig MTRR_SANITIZER_ENABLE_DEFAULT
1776f5098d62SYinghai Lu	int "MTRR cleanup enable value (0-1)"
1777f5098d62SYinghai Lu	range 0 1
1778f5098d62SYinghai Lu	default "0"
177995ffa243SYinghai Lu	depends on MTRR_SANITIZER
1780a7f7f624SMasahiro Yamada	help
1781f5098d62SYinghai Lu	  Enable mtrr cleanup default value
178295ffa243SYinghai Lu
178312031a62SYinghai Luconfig MTRR_SANITIZER_SPARE_REG_NR_DEFAULT
178412031a62SYinghai Lu	int "MTRR cleanup spare reg num (0-7)"
178512031a62SYinghai Lu	range 0 7
178612031a62SYinghai Lu	default "1"
178712031a62SYinghai Lu	depends on MTRR_SANITIZER
1788a7f7f624SMasahiro Yamada	help
178912031a62SYinghai Lu	  mtrr cleanup spare entries default, it can be changed via
1790aba3728cSThomas Gleixner	  mtrr_spare_reg_nr=N on the kernel command line.
179112031a62SYinghai Lu
17922e5d9c85Svenkatesh.pallipadi@intel.comconfig X86_PAT
17936fc108a0SJan Beulich	def_bool y
17946a108a14SDavid Rientjes	prompt "x86 PAT support" if EXPERT
17952a8a2719SIngo Molnar	depends on MTRR
1796a7f7f624SMasahiro Yamada	help
17972e5d9c85Svenkatesh.pallipadi@intel.com	  Use PAT attributes to setup page level cache control.
1798042b78e4SVenki Pallipadi
17992e5d9c85Svenkatesh.pallipadi@intel.com	  PATs are the modern equivalents of MTRRs and are much more
18002e5d9c85Svenkatesh.pallipadi@intel.com	  flexible than MTRRs.
18012e5d9c85Svenkatesh.pallipadi@intel.com
18022e5d9c85Svenkatesh.pallipadi@intel.com	  Say N here if you see bootup problems (boot crash, boot hang,
1803042b78e4SVenki Pallipadi	  spontaneous reboots) or a non-working video driver.
18042e5d9c85Svenkatesh.pallipadi@intel.com
18052e5d9c85Svenkatesh.pallipadi@intel.com	  If unsure, say Y.
18062e5d9c85Svenkatesh.pallipadi@intel.com
180746cf98cdSVenkatesh Pallipadiconfig ARCH_USES_PG_UNCACHED
180846cf98cdSVenkatesh Pallipadi	def_bool y
180946cf98cdSVenkatesh Pallipadi	depends on X86_PAT
181046cf98cdSVenkatesh Pallipadi
1811628c6246SH. Peter Anvinconfig ARCH_RANDOM
1812628c6246SH. Peter Anvin	def_bool y
1813628c6246SH. Peter Anvin	prompt "x86 architectural random number generator" if EXPERT
1814a7f7f624SMasahiro Yamada	help
1815628c6246SH. Peter Anvin	  Enable the x86 architectural RDRAND instruction
1816628c6246SH. Peter Anvin	  (Intel Bull Mountain technology) to generate random numbers.
1817628c6246SH. Peter Anvin	  If supported, this is a high bandwidth, cryptographically
1818628c6246SH. Peter Anvin	  secure hardware random number generator.
1819628c6246SH. Peter Anvin
182051ae4a2dSH. Peter Anvinconfig X86_SMAP
182151ae4a2dSH. Peter Anvin	def_bool y
182251ae4a2dSH. Peter Anvin	prompt "Supervisor Mode Access Prevention" if EXPERT
1823a7f7f624SMasahiro Yamada	help
182451ae4a2dSH. Peter Anvin	  Supervisor Mode Access Prevention (SMAP) is a security
182551ae4a2dSH. Peter Anvin	  feature in newer Intel processors.  There is a small
182651ae4a2dSH. Peter Anvin	  performance cost if this enabled and turned on; there is
182751ae4a2dSH. Peter Anvin	  also a small increase in the kernel size if this is enabled.
182851ae4a2dSH. Peter Anvin
182951ae4a2dSH. Peter Anvin	  If unsure, say Y.
183051ae4a2dSH. Peter Anvin
1831b971880fSBabu Mogerconfig X86_UMIP
1832796ebc81SRicardo Neri	def_bool y
1833b971880fSBabu Moger	prompt "User Mode Instruction Prevention" if EXPERT
1834a7f7f624SMasahiro Yamada	help
1835b971880fSBabu Moger	  User Mode Instruction Prevention (UMIP) is a security feature in
1836b971880fSBabu Moger	  some x86 processors. If enabled, a general protection fault is
1837b971880fSBabu Moger	  issued if the SGDT, SLDT, SIDT, SMSW or STR instructions are
1838b971880fSBabu Moger	  executed in user mode. These instructions unnecessarily expose
1839b971880fSBabu Moger	  information about the hardware state.
1840796ebc81SRicardo Neri
1841796ebc81SRicardo Neri	  The vast majority of applications do not use these instructions.
1842796ebc81SRicardo Neri	  For the very few that do, software emulation is provided in
1843796ebc81SRicardo Neri	  specific cases in protected and virtual-8086 modes. Emulated
1844796ebc81SRicardo Neri	  results are dummy.
1845aa35f896SRicardo Neri
1846156ff4a5SPeter Zijlstraconfig CC_HAS_IBT
1847156ff4a5SPeter Zijlstra	# GCC >= 9 and binutils >= 2.29
1848156ff4a5SPeter Zijlstra	# Retpoline check to work around https://gcc.gnu.org/bugzilla/show_bug.cgi?id=93654
1849156ff4a5SPeter Zijlstra	# Clang/LLVM >= 14
1850262448f3SNathan Chancellor	# https://github.com/llvm/llvm-project/commit/e0b89df2e0f0130881bf6c39bf31d7f6aac00e0f
1851262448f3SNathan Chancellor	# https://github.com/llvm/llvm-project/commit/dfcf69770bc522b9e411c66454934a37c1f35332
1852156ff4a5SPeter Zijlstra	def_bool ((CC_IS_GCC && $(cc-option, -fcf-protection=branch -mindirect-branch-register)) || \
1853262448f3SNathan Chancellor		  (CC_IS_CLANG && CLANG_VERSION >= 140000)) && \
1854156ff4a5SPeter Zijlstra		  $(as-instr,endbr64)
1855156ff4a5SPeter Zijlstra
1856156ff4a5SPeter Zijlstraconfig X86_KERNEL_IBT
1857156ff4a5SPeter Zijlstra	prompt "Indirect Branch Tracking"
1858156ff4a5SPeter Zijlstra	bool
1859ed53a0d9SPeter Zijlstra	depends on X86_64 && CC_HAS_IBT && STACK_VALIDATION
1860f6a2c2b2SNathan Chancellor	# https://github.com/llvm/llvm-project/commit/9d7001eba9c4cb311e03cd8cdc231f9e579f2d0f
1861f6a2c2b2SNathan Chancellor	depends on !LD_IS_LLD || LLD_VERSION >= 140000
1862156ff4a5SPeter Zijlstra	help
1863156ff4a5SPeter Zijlstra	  Build the kernel with support for Indirect Branch Tracking, a
1864156ff4a5SPeter Zijlstra	  hardware support course-grain forward-edge Control Flow Integrity
1865156ff4a5SPeter Zijlstra	  protection. It enforces that all indirect calls must land on
1866156ff4a5SPeter Zijlstra	  an ENDBR instruction, as such, the compiler will instrument the
1867156ff4a5SPeter Zijlstra	  code with them to make this happen.
1868156ff4a5SPeter Zijlstra
1869ed53a0d9SPeter Zijlstra	  In addition to building the kernel with IBT, seal all functions that
1870ed53a0d9SPeter Zijlstra	  are not indirect call targets, avoiding them ever becomming one.
1871ed53a0d9SPeter Zijlstra
1872ed53a0d9SPeter Zijlstra	  This requires LTO like objtool runs and will slow down the build. It
1873ed53a0d9SPeter Zijlstra	  does significantly reduce the number of ENDBR instructions in the
1874ed53a0d9SPeter Zijlstra	  kernel image.
1875ed53a0d9SPeter Zijlstra
187635e97790SDave Hansenconfig X86_INTEL_MEMORY_PROTECTION_KEYS
187738f3e775SBabu Moger	prompt "Memory Protection Keys"
187835e97790SDave Hansen	def_bool y
1879284244a9SDave Hansen	# Note: only available in 64-bit mode
188038f3e775SBabu Moger	depends on X86_64 && (CPU_SUP_INTEL || CPU_SUP_AMD)
188152c8e601SIngo Molnar	select ARCH_USES_HIGH_VMA_FLAGS
188252c8e601SIngo Molnar	select ARCH_HAS_PKEYS
1883a7f7f624SMasahiro Yamada	help
1884284244a9SDave Hansen	  Memory Protection Keys provides a mechanism for enforcing
1885284244a9SDave Hansen	  page-based protections, but without requiring modification of the
1886284244a9SDave Hansen	  page tables when an application changes protection domains.
1887284244a9SDave Hansen
18881eecbcdcSMauro Carvalho Chehab	  For details, see Documentation/core-api/protection-keys.rst
1889284244a9SDave Hansen
1890284244a9SDave Hansen	  If unsure, say y.
189135e97790SDave Hansen
1892db616173SMichal Hockochoice
1893db616173SMichal Hocko	prompt "TSX enable mode"
1894db616173SMichal Hocko	depends on CPU_SUP_INTEL
1895db616173SMichal Hocko	default X86_INTEL_TSX_MODE_OFF
1896db616173SMichal Hocko	help
1897db616173SMichal Hocko	  Intel's TSX (Transactional Synchronization Extensions) feature
1898db616173SMichal Hocko	  allows to optimize locking protocols through lock elision which
1899db616173SMichal Hocko	  can lead to a noticeable performance boost.
1900db616173SMichal Hocko
1901db616173SMichal Hocko	  On the other hand it has been shown that TSX can be exploited
1902db616173SMichal Hocko	  to form side channel attacks (e.g. TAA) and chances are there
1903db616173SMichal Hocko	  will be more of those attacks discovered in the future.
1904db616173SMichal Hocko
1905db616173SMichal Hocko	  Therefore TSX is not enabled by default (aka tsx=off). An admin
1906db616173SMichal Hocko	  might override this decision by tsx=on the command line parameter.
1907db616173SMichal Hocko	  Even with TSX enabled, the kernel will attempt to enable the best
1908db616173SMichal Hocko	  possible TAA mitigation setting depending on the microcode available
1909db616173SMichal Hocko	  for the particular machine.
1910db616173SMichal Hocko
1911db616173SMichal Hocko	  This option allows to set the default tsx mode between tsx=on, =off
1912db616173SMichal Hocko	  and =auto. See Documentation/admin-guide/kernel-parameters.txt for more
1913db616173SMichal Hocko	  details.
1914db616173SMichal Hocko
1915db616173SMichal Hocko	  Say off if not sure, auto if TSX is in use but it should be used on safe
1916db616173SMichal Hocko	  platforms or on if TSX is in use and the security aspect of tsx is not
1917db616173SMichal Hocko	  relevant.
1918db616173SMichal Hocko
1919db616173SMichal Hockoconfig X86_INTEL_TSX_MODE_OFF
1920db616173SMichal Hocko	bool "off"
1921db616173SMichal Hocko	help
1922db616173SMichal Hocko	  TSX is disabled if possible - equals to tsx=off command line parameter.
1923db616173SMichal Hocko
1924db616173SMichal Hockoconfig X86_INTEL_TSX_MODE_ON
1925db616173SMichal Hocko	bool "on"
1926db616173SMichal Hocko	help
1927db616173SMichal Hocko	  TSX is always enabled on TSX capable HW - equals the tsx=on command
1928db616173SMichal Hocko	  line parameter.
1929db616173SMichal Hocko
1930db616173SMichal Hockoconfig X86_INTEL_TSX_MODE_AUTO
1931db616173SMichal Hocko	bool "auto"
1932db616173SMichal Hocko	help
1933db616173SMichal Hocko	  TSX is enabled on TSX capable HW that is believed to be safe against
1934db616173SMichal Hocko	  side channel attacks- equals the tsx=auto command line parameter.
1935db616173SMichal Hockoendchoice
1936db616173SMichal Hocko
1937e7e05452SSean Christophersonconfig X86_SGX
1938e7e05452SSean Christopherson	bool "Software Guard eXtensions (SGX)"
1939e7e05452SSean Christopherson	depends on X86_64 && CPU_SUP_INTEL
1940e7e05452SSean Christopherson	depends on CRYPTO=y
1941e7e05452SSean Christopherson	depends on CRYPTO_SHA256=y
1942e7e05452SSean Christopherson	select SRCU
1943e7e05452SSean Christopherson	select MMU_NOTIFIER
1944901ddbb9SJarkko Sakkinen	select NUMA_KEEP_MEMINFO if NUMA
194540e0e784STony Luck	select XARRAY_MULTI
1946e7e05452SSean Christopherson	help
1947e7e05452SSean Christopherson	  Intel(R) Software Guard eXtensions (SGX) is a set of CPU instructions
1948e7e05452SSean Christopherson	  that can be used by applications to set aside private regions of code
1949e7e05452SSean Christopherson	  and data, referred to as enclaves. An enclave's private memory can
1950e7e05452SSean Christopherson	  only be accessed by code running within the enclave. Accesses from
1951e7e05452SSean Christopherson	  outside the enclave, including other enclaves, are disallowed by
1952e7e05452SSean Christopherson	  hardware.
1953e7e05452SSean Christopherson
1954e7e05452SSean Christopherson	  If unsure, say N.
1955e7e05452SSean Christopherson
1956506f1d07SSam Ravnborgconfig EFI
19579ba16087SJan Beulich	bool "EFI runtime service support"
19585b83683fSHuang, Ying	depends on ACPI
1959f6ce5002SSergey Vlasov	select UCS2_STRING
1960022ee6c5SArd Biesheuvel	select EFI_RUNTIME_WRAPPERS
19611ff2fc02STom Lendacky	select ARCH_USE_MEMREMAP_PROT
1962a7f7f624SMasahiro Yamada	help
19638b2cb7a8SHuang, Ying	  This enables the kernel to use EFI runtime services that are
1964506f1d07SSam Ravnborg	  available (such as the EFI variable services).
1965506f1d07SSam Ravnborg
19668b2cb7a8SHuang, Ying	  This option is only useful on systems that have EFI firmware.
19678b2cb7a8SHuang, Ying	  In addition, you should use the latest ELILO loader available
19688b2cb7a8SHuang, Ying	  at <http://elilo.sourceforge.net> in order to take advantage
19698b2cb7a8SHuang, Ying	  of EFI runtime services. However, even with this option, the
19708b2cb7a8SHuang, Ying	  resultant kernel should continue to boot on existing non-EFI
19718b2cb7a8SHuang, Ying	  platforms.
1972506f1d07SSam Ravnborg
1973291f3632SMatt Flemingconfig EFI_STUB
1974291f3632SMatt Fleming	bool "EFI stub support"
1975c6dbd3e5SPeter Zijlstra	depends on EFI
19768f24f8c2SArd Biesheuvel	depends on $(cc-option,-mabi=ms) || X86_32
19777b2a583aSMatt Fleming	select RELOCATABLE
1978a7f7f624SMasahiro Yamada	help
1979291f3632SMatt Fleming	  This kernel feature allows a bzImage to be loaded directly
1980291f3632SMatt Fleming	  by EFI firmware without the use of a bootloader.
1981291f3632SMatt Fleming
19824f4cfa6cSMauro Carvalho Chehab	  See Documentation/admin-guide/efi-stub.rst for more information.
19830c759662SMatt Fleming
19847d453eeeSMatt Flemingconfig EFI_MIXED
19857d453eeeSMatt Fleming	bool "EFI mixed-mode support"
19867d453eeeSMatt Fleming	depends on EFI_STUB && X86_64
1987a7f7f624SMasahiro Yamada	help
19887d453eeeSMatt Fleming	   Enabling this feature allows a 64-bit kernel to be booted
19897d453eeeSMatt Fleming	   on a 32-bit firmware, provided that your CPU supports 64-bit
19907d453eeeSMatt Fleming	   mode.
19917d453eeeSMatt Fleming
19927d453eeeSMatt Fleming	   Note that it is not possible to boot a mixed-mode enabled
19937d453eeeSMatt Fleming	   kernel via the EFI boot stub - a bootloader that supports
19947d453eeeSMatt Fleming	   the EFI handover protocol must be used.
19957d453eeeSMatt Fleming
19967d453eeeSMatt Fleming	   If unsure, say N.
19977d453eeeSMatt Fleming
19988636a1f9SMasahiro Yamadasource "kernel/Kconfig.hz"
1999506f1d07SSam Ravnborg
2000506f1d07SSam Ravnborgconfig KEXEC
2001506f1d07SSam Ravnborg	bool "kexec system call"
20022965faa5SDave Young	select KEXEC_CORE
2003a7f7f624SMasahiro Yamada	help
2004506f1d07SSam Ravnborg	  kexec is a system call that implements the ability to shutdown your
2005506f1d07SSam Ravnborg	  current kernel, and to start another kernel.  It is like a reboot
2006506f1d07SSam Ravnborg	  but it is independent of the system firmware.   And like a reboot
2007506f1d07SSam Ravnborg	  you can start any kernel with it, not just Linux.
2008506f1d07SSam Ravnborg
2009506f1d07SSam Ravnborg	  The name comes from the similarity to the exec system call.
2010506f1d07SSam Ravnborg
2011506f1d07SSam Ravnborg	  It is an ongoing process to be certain the hardware in a machine
2012506f1d07SSam Ravnborg	  is properly shutdown, so do not be surprised if this code does not
2013bf220695SGeert Uytterhoeven	  initially work for you.  As of this writing the exact hardware
2014bf220695SGeert Uytterhoeven	  interface is strongly in flux, so no good recommendation can be
2015bf220695SGeert Uytterhoeven	  made.
2016506f1d07SSam Ravnborg
201774ca317cSVivek Goyalconfig KEXEC_FILE
201874ca317cSVivek Goyal	bool "kexec file based system call"
20192965faa5SDave Young	select KEXEC_CORE
202074ca317cSVivek Goyal	select BUILD_BIN2C
202174ca317cSVivek Goyal	depends on X86_64
202274ca317cSVivek Goyal	depends on CRYPTO=y
202374ca317cSVivek Goyal	depends on CRYPTO_SHA256=y
2024a7f7f624SMasahiro Yamada	help
202574ca317cSVivek Goyal	  This is new version of kexec system call. This system call is
202674ca317cSVivek Goyal	  file based and takes file descriptors as system call argument
202774ca317cSVivek Goyal	  for kernel and initramfs as opposed to list of segments as
202874ca317cSVivek Goyal	  accepted by previous system call.
202974ca317cSVivek Goyal
2030b799a09fSAKASHI Takahiroconfig ARCH_HAS_KEXEC_PURGATORY
2031b799a09fSAKASHI Takahiro	def_bool KEXEC_FILE
2032b799a09fSAKASHI Takahiro
203399d5cadfSJiri Bohacconfig KEXEC_SIG
20348e7d8381SVivek Goyal	bool "Verify kernel signature during kexec_file_load() syscall"
203574ca317cSVivek Goyal	depends on KEXEC_FILE
2036a7f7f624SMasahiro Yamada	help
203799d5cadfSJiri Bohac
203899d5cadfSJiri Bohac	  This option makes the kexec_file_load() syscall check for a valid
203999d5cadfSJiri Bohac	  signature of the kernel image.  The image can still be loaded without
204099d5cadfSJiri Bohac	  a valid signature unless you also enable KEXEC_SIG_FORCE, though if
204199d5cadfSJiri Bohac	  there's a signature that we can check, then it must be valid.
204299d5cadfSJiri Bohac
204399d5cadfSJiri Bohac	  In addition to this option, you need to enable signature
204499d5cadfSJiri Bohac	  verification for the corresponding kernel image type being
204599d5cadfSJiri Bohac	  loaded in order for this to work.
204699d5cadfSJiri Bohac
204799d5cadfSJiri Bohacconfig KEXEC_SIG_FORCE
204899d5cadfSJiri Bohac	bool "Require a valid signature in kexec_file_load() syscall"
204999d5cadfSJiri Bohac	depends on KEXEC_SIG
2050a7f7f624SMasahiro Yamada	help
20518e7d8381SVivek Goyal	  This option makes kernel signature verification mandatory for
2052d8eb8940SBorislav Petkov	  the kexec_file_load() syscall.
20538e7d8381SVivek Goyal
20548e7d8381SVivek Goyalconfig KEXEC_BZIMAGE_VERIFY_SIG
20558e7d8381SVivek Goyal	bool "Enable bzImage signature verification support"
205699d5cadfSJiri Bohac	depends on KEXEC_SIG
20578e7d8381SVivek Goyal	depends on SIGNED_PE_FILE_VERIFICATION
20588e7d8381SVivek Goyal	select SYSTEM_TRUSTED_KEYRING
2059a7f7f624SMasahiro Yamada	help
20608e7d8381SVivek Goyal	  Enable bzImage signature verification support.
20618e7d8381SVivek Goyal
2062506f1d07SSam Ravnborgconfig CRASH_DUMP
206304b69447SPavel Machek	bool "kernel crash dumps"
2064506f1d07SSam Ravnborg	depends on X86_64 || (X86_32 && HIGHMEM)
2065a7f7f624SMasahiro Yamada	help
2066506f1d07SSam Ravnborg	  Generate crash dump after being started by kexec.
2067506f1d07SSam Ravnborg	  This should be normally only set in special crash dump kernels
2068506f1d07SSam Ravnborg	  which are loaded in the main kernel with kexec-tools into
2069506f1d07SSam Ravnborg	  a specially reserved region and then later executed after
2070506f1d07SSam Ravnborg	  a crash by kdump/kexec. The crash dump kernel must be compiled
2071506f1d07SSam Ravnborg	  to a memory address not used by the main kernel or BIOS using
2072506f1d07SSam Ravnborg	  PHYSICAL_START, or it must be built as a relocatable image
2073506f1d07SSam Ravnborg	  (CONFIG_RELOCATABLE=y).
2074330d4810SMauro Carvalho Chehab	  For more details see Documentation/admin-guide/kdump/kdump.rst
2075506f1d07SSam Ravnborg
20763ab83521SHuang Yingconfig KEXEC_JUMP
20776ea30386SKees Cook	bool "kexec jump"
2078fee7b0d8SHuang Ying	depends on KEXEC && HIBERNATION
2079a7f7f624SMasahiro Yamada	help
208089081d17SHuang Ying	  Jump between original kernel and kexeced kernel and invoke
208189081d17SHuang Ying	  code in physical address mode via KEXEC
20823ab83521SHuang Ying
2083506f1d07SSam Ravnborgconfig PHYSICAL_START
20846a108a14SDavid Rientjes	hex "Physical address where the kernel is loaded" if (EXPERT || CRASH_DUMP)
2085ceefccc9SH. Peter Anvin	default "0x1000000"
2086a7f7f624SMasahiro Yamada	help
2087506f1d07SSam Ravnborg	  This gives the physical address where the kernel is loaded.
2088506f1d07SSam Ravnborg
2089506f1d07SSam Ravnborg	  If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then
2090506f1d07SSam Ravnborg	  bzImage will decompress itself to above physical address and
2091506f1d07SSam Ravnborg	  run from there. Otherwise, bzImage will run from the address where
2092506f1d07SSam Ravnborg	  it has been loaded by the boot loader and will ignore above physical
2093506f1d07SSam Ravnborg	  address.
2094506f1d07SSam Ravnborg
2095506f1d07SSam Ravnborg	  In normal kdump cases one does not have to set/change this option
2096506f1d07SSam Ravnborg	  as now bzImage can be compiled as a completely relocatable image
2097506f1d07SSam Ravnborg	  (CONFIG_RELOCATABLE=y) and be used to load and run from a different
2098506f1d07SSam Ravnborg	  address. This option is mainly useful for the folks who don't want
2099506f1d07SSam Ravnborg	  to use a bzImage for capturing the crash dump and want to use a
2100506f1d07SSam Ravnborg	  vmlinux instead. vmlinux is not relocatable hence a kernel needs
2101506f1d07SSam Ravnborg	  to be specifically compiled to run from a specific memory area
2102506f1d07SSam Ravnborg	  (normally a reserved region) and this option comes handy.
2103506f1d07SSam Ravnborg
2104ceefccc9SH. Peter Anvin	  So if you are using bzImage for capturing the crash dump,
2105ceefccc9SH. Peter Anvin	  leave the value here unchanged to 0x1000000 and set
2106ceefccc9SH. Peter Anvin	  CONFIG_RELOCATABLE=y.  Otherwise if you plan to use vmlinux
2107ceefccc9SH. Peter Anvin	  for capturing the crash dump change this value to start of
2108ceefccc9SH. Peter Anvin	  the reserved region.  In other words, it can be set based on
2109ceefccc9SH. Peter Anvin	  the "X" value as specified in the "crashkernel=YM@XM"
2110ceefccc9SH. Peter Anvin	  command line boot parameter passed to the panic-ed
2111330d4810SMauro Carvalho Chehab	  kernel. Please take a look at Documentation/admin-guide/kdump/kdump.rst
2112ceefccc9SH. Peter Anvin	  for more details about crash dumps.
2113506f1d07SSam Ravnborg
2114506f1d07SSam Ravnborg	  Usage of bzImage for capturing the crash dump is recommended as
2115506f1d07SSam Ravnborg	  one does not have to build two kernels. Same kernel can be used
2116506f1d07SSam Ravnborg	  as production kernel and capture kernel. Above option should have
2117506f1d07SSam Ravnborg	  gone away after relocatable bzImage support is introduced. But it
2118506f1d07SSam Ravnborg	  is present because there are users out there who continue to use
2119506f1d07SSam Ravnborg	  vmlinux for dump capture. This option should go away down the
2120506f1d07SSam Ravnborg	  line.
2121506f1d07SSam Ravnborg
2122506f1d07SSam Ravnborg	  Don't change this unless you know what you are doing.
2123506f1d07SSam Ravnborg
2124506f1d07SSam Ravnborgconfig RELOCATABLE
212526717808SH. Peter Anvin	bool "Build a relocatable kernel"
212626717808SH. Peter Anvin	default y
2127a7f7f624SMasahiro Yamada	help
2128506f1d07SSam Ravnborg	  This builds a kernel image that retains relocation information
2129506f1d07SSam Ravnborg	  so it can be loaded someplace besides the default 1MB.
2130506f1d07SSam Ravnborg	  The relocations tend to make the kernel binary about 10% larger,
2131506f1d07SSam Ravnborg	  but are discarded at runtime.
2132506f1d07SSam Ravnborg
2133506f1d07SSam Ravnborg	  One use is for the kexec on panic case where the recovery kernel
2134506f1d07SSam Ravnborg	  must live at a different physical address than the primary
2135506f1d07SSam Ravnborg	  kernel.
2136506f1d07SSam Ravnborg
2137506f1d07SSam Ravnborg	  Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address
2138506f1d07SSam Ravnborg	  it has been loaded at and the compile time physical address
21398ab3820fSKees Cook	  (CONFIG_PHYSICAL_START) is used as the minimum location.
2140506f1d07SSam Ravnborg
21418ab3820fSKees Cookconfig RANDOMIZE_BASE
2142e8581e3dSBaoquan He	bool "Randomize the address of the kernel image (KASLR)"
21438ab3820fSKees Cook	depends on RELOCATABLE
21446807c846SIngo Molnar	default y
2145a7f7f624SMasahiro Yamada	help
2146e8581e3dSBaoquan He	  In support of Kernel Address Space Layout Randomization (KASLR),
2147e8581e3dSBaoquan He	  this randomizes the physical address at which the kernel image
2148e8581e3dSBaoquan He	  is decompressed and the virtual address where the kernel
2149e8581e3dSBaoquan He	  image is mapped, as a security feature that deters exploit
2150e8581e3dSBaoquan He	  attempts relying on knowledge of the location of kernel
2151e8581e3dSBaoquan He	  code internals.
2152e8581e3dSBaoquan He
2153ed9f007eSKees Cook	  On 64-bit, the kernel physical and virtual addresses are
2154ed9f007eSKees Cook	  randomized separately. The physical address will be anywhere
2155ed9f007eSKees Cook	  between 16MB and the top of physical memory (up to 64TB). The
2156ed9f007eSKees Cook	  virtual address will be randomized from 16MB up to 1GB (9 bits
2157ed9f007eSKees Cook	  of entropy). Note that this also reduces the memory space
2158ed9f007eSKees Cook	  available to kernel modules from 1.5GB to 1GB.
2159ed9f007eSKees Cook
2160ed9f007eSKees Cook	  On 32-bit, the kernel physical and virtual addresses are
2161ed9f007eSKees Cook	  randomized together. They will be randomized from 16MB up to
2162ed9f007eSKees Cook	  512MB (8 bits of entropy).
21638ab3820fSKees Cook
2164a653f356SKees Cook	  Entropy is generated using the RDRAND instruction if it is
2165e8581e3dSBaoquan He	  supported. If RDTSC is supported, its value is mixed into
2166e8581e3dSBaoquan He	  the entropy pool as well. If neither RDRAND nor RDTSC are
2167ed9f007eSKees Cook	  supported, then entropy is read from the i8254 timer. The
2168ed9f007eSKees Cook	  usable entropy is limited by the kernel being built using
2169ed9f007eSKees Cook	  2GB addressing, and that PHYSICAL_ALIGN must be at a
2170ed9f007eSKees Cook	  minimum of 2MB. As a result, only 10 bits of entropy are
2171ed9f007eSKees Cook	  theoretically possible, but the implementations are further
2172ed9f007eSKees Cook	  limited due to memory layouts.
2173e8581e3dSBaoquan He
21746807c846SIngo Molnar	  If unsure, say Y.
2175da2b6fb9SKees Cook
21768ab3820fSKees Cook# Relocation on x86 needs some additional build support
2177845adf72SH. Peter Anvinconfig X86_NEED_RELOCS
2178845adf72SH. Peter Anvin	def_bool y
21798ab3820fSKees Cook	depends on RANDOMIZE_BASE || (X86_32 && RELOCATABLE)
2180845adf72SH. Peter Anvin
2181506f1d07SSam Ravnborgconfig PHYSICAL_ALIGN
2182a0215061SKees Cook	hex "Alignment value to which kernel should be aligned"
21838ab3820fSKees Cook	default "0x200000"
2184a0215061SKees Cook	range 0x2000 0x1000000 if X86_32
2185a0215061SKees Cook	range 0x200000 0x1000000 if X86_64
2186a7f7f624SMasahiro Yamada	help
2187506f1d07SSam Ravnborg	  This value puts the alignment restrictions on physical address
2188506f1d07SSam Ravnborg	  where kernel is loaded and run from. Kernel is compiled for an
2189506f1d07SSam Ravnborg	  address which meets above alignment restriction.
2190506f1d07SSam Ravnborg
2191506f1d07SSam Ravnborg	  If bootloader loads the kernel at a non-aligned address and
2192506f1d07SSam Ravnborg	  CONFIG_RELOCATABLE is set, kernel will move itself to nearest
2193506f1d07SSam Ravnborg	  address aligned to above value and run from there.
2194506f1d07SSam Ravnborg
2195506f1d07SSam Ravnborg	  If bootloader loads the kernel at a non-aligned address and
2196506f1d07SSam Ravnborg	  CONFIG_RELOCATABLE is not set, kernel will ignore the run time
2197506f1d07SSam Ravnborg	  load address and decompress itself to the address it has been
2198506f1d07SSam Ravnborg	  compiled for and run from there. The address for which kernel is
2199506f1d07SSam Ravnborg	  compiled already meets above alignment restrictions. Hence the
2200506f1d07SSam Ravnborg	  end result is that kernel runs from a physical address meeting
2201506f1d07SSam Ravnborg	  above alignment restrictions.
2202506f1d07SSam Ravnborg
2203a0215061SKees Cook	  On 32-bit this value must be a multiple of 0x2000. On 64-bit
2204a0215061SKees Cook	  this value must be a multiple of 0x200000.
2205a0215061SKees Cook
2206506f1d07SSam Ravnborg	  Don't change this unless you know what you are doing.
2207506f1d07SSam Ravnborg
2208eedb92abSKirill A. Shutemovconfig DYNAMIC_MEMORY_LAYOUT
2209eedb92abSKirill A. Shutemov	bool
2210a7f7f624SMasahiro Yamada	help
2211eedb92abSKirill A. Shutemov	  This option makes base addresses of vmalloc and vmemmap as well as
2212eedb92abSKirill A. Shutemov	  __PAGE_OFFSET movable during boot.
2213eedb92abSKirill A. Shutemov
22140483e1faSThomas Garnierconfig RANDOMIZE_MEMORY
22150483e1faSThomas Garnier	bool "Randomize the kernel memory sections"
22160483e1faSThomas Garnier	depends on X86_64
22170483e1faSThomas Garnier	depends on RANDOMIZE_BASE
2218eedb92abSKirill A. Shutemov	select DYNAMIC_MEMORY_LAYOUT
22190483e1faSThomas Garnier	default RANDOMIZE_BASE
2220a7f7f624SMasahiro Yamada	help
22210483e1faSThomas Garnier	   Randomizes the base virtual address of kernel memory sections
22220483e1faSThomas Garnier	   (physical memory mapping, vmalloc & vmemmap). This security feature
22230483e1faSThomas Garnier	   makes exploits relying on predictable memory locations less reliable.
22240483e1faSThomas Garnier
22250483e1faSThomas Garnier	   The order of allocations remains unchanged. Entropy is generated in
22260483e1faSThomas Garnier	   the same way as RANDOMIZE_BASE. Current implementation in the optimal
22270483e1faSThomas Garnier	   configuration have in average 30,000 different possible virtual
22280483e1faSThomas Garnier	   addresses for each memory section.
22290483e1faSThomas Garnier
22306807c846SIngo Molnar	   If unsure, say Y.
22310483e1faSThomas Garnier
223290397a41SThomas Garnierconfig RANDOMIZE_MEMORY_PHYSICAL_PADDING
223390397a41SThomas Garnier	hex "Physical memory mapping padding" if EXPERT
223490397a41SThomas Garnier	depends on RANDOMIZE_MEMORY
223590397a41SThomas Garnier	default "0xa" if MEMORY_HOTPLUG
223690397a41SThomas Garnier	default "0x0"
223790397a41SThomas Garnier	range 0x1 0x40 if MEMORY_HOTPLUG
223890397a41SThomas Garnier	range 0x0 0x40
2239a7f7f624SMasahiro Yamada	help
224090397a41SThomas Garnier	   Define the padding in terabytes added to the existing physical
224190397a41SThomas Garnier	   memory size during kernel memory randomization. It is useful
224290397a41SThomas Garnier	   for memory hotplug support but reduces the entropy available for
224390397a41SThomas Garnier	   address randomization.
224490397a41SThomas Garnier
224590397a41SThomas Garnier	   If unsure, leave at the default value.
224690397a41SThomas Garnier
2247506f1d07SSam Ravnborgconfig HOTPLUG_CPU
2248bebd024eSThomas Gleixner	def_bool y
224940b31360SStephen Rothwell	depends on SMP
2250506f1d07SSam Ravnborg
225180aa1dffSFenghua Yuconfig BOOTPARAM_HOTPLUG_CPU0
225280aa1dffSFenghua Yu	bool "Set default setting of cpu0_hotpluggable"
22532c922cd0SKees Cook	depends on HOTPLUG_CPU
2254a7f7f624SMasahiro Yamada	help
225580aa1dffSFenghua Yu	  Set whether default state of cpu0_hotpluggable is on or off.
225680aa1dffSFenghua Yu
225780aa1dffSFenghua Yu	  Say Y here to enable CPU0 hotplug by default. If this switch
225880aa1dffSFenghua Yu	  is turned on, there is no need to give cpu0_hotplug kernel
225980aa1dffSFenghua Yu	  parameter and the CPU0 hotplug feature is enabled by default.
226080aa1dffSFenghua Yu
226180aa1dffSFenghua Yu	  Please note: there are two known CPU0 dependencies if you want
226280aa1dffSFenghua Yu	  to enable the CPU0 hotplug feature either by this switch or by
226380aa1dffSFenghua Yu	  cpu0_hotplug kernel parameter.
226480aa1dffSFenghua Yu
226580aa1dffSFenghua Yu	  First, resume from hibernate or suspend always starts from CPU0.
226680aa1dffSFenghua Yu	  So hibernate and suspend are prevented if CPU0 is offline.
226780aa1dffSFenghua Yu
226880aa1dffSFenghua Yu	  Second dependency is PIC interrupts always go to CPU0. CPU0 can not
226980aa1dffSFenghua Yu	  offline if any interrupt can not migrate out of CPU0. There may
227080aa1dffSFenghua Yu	  be other CPU0 dependencies.
227180aa1dffSFenghua Yu
227280aa1dffSFenghua Yu	  Please make sure the dependencies are under your control before
227380aa1dffSFenghua Yu	  you enable this feature.
227480aa1dffSFenghua Yu
227580aa1dffSFenghua Yu	  Say N if you don't want to enable CPU0 hotplug feature by default.
227680aa1dffSFenghua Yu	  You still can enable the CPU0 hotplug feature at boot by kernel
227780aa1dffSFenghua Yu	  parameter cpu0_hotplug.
227880aa1dffSFenghua Yu
2279a71c8bc5SFenghua Yuconfig DEBUG_HOTPLUG_CPU0
2280a71c8bc5SFenghua Yu	def_bool n
2281a71c8bc5SFenghua Yu	prompt "Debug CPU0 hotplug"
22822c922cd0SKees Cook	depends on HOTPLUG_CPU
2283a7f7f624SMasahiro Yamada	help
2284a71c8bc5SFenghua Yu	  Enabling this option offlines CPU0 (if CPU0 can be offlined) as
2285a71c8bc5SFenghua Yu	  soon as possible and boots up userspace with CPU0 offlined. User
2286a71c8bc5SFenghua Yu	  can online CPU0 back after boot time.
2287a71c8bc5SFenghua Yu
2288a71c8bc5SFenghua Yu	  To debug CPU0 hotplug, you need to enable CPU0 offline/online
2289a71c8bc5SFenghua Yu	  feature by either turning on CONFIG_BOOTPARAM_HOTPLUG_CPU0 during
2290a71c8bc5SFenghua Yu	  compilation or giving cpu0_hotplug kernel parameter at boot.
2291a71c8bc5SFenghua Yu
2292a71c8bc5SFenghua Yu	  If unsure, say N.
2293a71c8bc5SFenghua Yu
2294506f1d07SSam Ravnborgconfig COMPAT_VDSO
2295b0b49f26SAndy Lutomirski	def_bool n
2296b0b49f26SAndy Lutomirski	prompt "Disable the 32-bit vDSO (needed for glibc 2.3.3)"
2297953fee1dSIngo Molnar	depends on COMPAT_32
2298a7f7f624SMasahiro Yamada	help
2299b0b49f26SAndy Lutomirski	  Certain buggy versions of glibc will crash if they are
2300b0b49f26SAndy Lutomirski	  presented with a 32-bit vDSO that is not mapped at the address
2301b0b49f26SAndy Lutomirski	  indicated in its segment table.
2302e84446deSRandy Dunlap
2303b0b49f26SAndy Lutomirski	  The bug was introduced by f866314b89d56845f55e6f365e18b31ec978ec3a
2304b0b49f26SAndy Lutomirski	  and fixed by 3b3ddb4f7db98ec9e912ccdf54d35df4aa30e04a and
2305b0b49f26SAndy Lutomirski	  49ad572a70b8aeb91e57483a11dd1b77e31c4468.  Glibc 2.3.3 is
2306b0b49f26SAndy Lutomirski	  the only released version with the bug, but OpenSUSE 9
2307b0b49f26SAndy Lutomirski	  contains a buggy "glibc 2.3.2".
2308506f1d07SSam Ravnborg
2309b0b49f26SAndy Lutomirski	  The symptom of the bug is that everything crashes on startup, saying:
2310b0b49f26SAndy Lutomirski	  dl_main: Assertion `(void *) ph->p_vaddr == _rtld_local._dl_sysinfo_dso' failed!
2311b0b49f26SAndy Lutomirski
2312b0b49f26SAndy Lutomirski	  Saying Y here changes the default value of the vdso32 boot
2313b0b49f26SAndy Lutomirski	  option from 1 to 0, which turns off the 32-bit vDSO entirely.
2314b0b49f26SAndy Lutomirski	  This works around the glibc bug but hurts performance.
2315b0b49f26SAndy Lutomirski
2316b0b49f26SAndy Lutomirski	  If unsure, say N: if you are compiling your own kernel, you
2317b0b49f26SAndy Lutomirski	  are unlikely to be using a buggy version of glibc.
2318506f1d07SSam Ravnborg
23193dc33bd3SKees Cookchoice
23203dc33bd3SKees Cook	prompt "vsyscall table for legacy applications"
23213dc33bd3SKees Cook	depends on X86_64
2322625b7b7fSAndy Lutomirski	default LEGACY_VSYSCALL_XONLY
23233dc33bd3SKees Cook	help
23243dc33bd3SKees Cook	  Legacy user code that does not know how to find the vDSO expects
23253dc33bd3SKees Cook	  to be able to issue three syscalls by calling fixed addresses in
23263dc33bd3SKees Cook	  kernel space. Since this location is not randomized with ASLR,
23273dc33bd3SKees Cook	  it can be used to assist security vulnerability exploitation.
23283dc33bd3SKees Cook
23293dc33bd3SKees Cook	  This setting can be changed at boot time via the kernel command
2330bd49e16eSAndy Lutomirski	  line parameter vsyscall=[emulate|xonly|none].
23313dc33bd3SKees Cook
23323dc33bd3SKees Cook	  On a system with recent enough glibc (2.14 or newer) and no
23333dc33bd3SKees Cook	  static binaries, you can say None without a performance penalty
23343dc33bd3SKees Cook	  to improve security.
23353dc33bd3SKees Cook
2336bd49e16eSAndy Lutomirski	  If unsure, select "Emulate execution only".
23373dc33bd3SKees Cook
23383dc33bd3SKees Cook	config LEGACY_VSYSCALL_EMULATE
2339bd49e16eSAndy Lutomirski		bool "Full emulation"
23403dc33bd3SKees Cook		help
2341bd49e16eSAndy Lutomirski		  The kernel traps and emulates calls into the fixed vsyscall
2342bd49e16eSAndy Lutomirski		  address mapping. This makes the mapping non-executable, but
2343bd49e16eSAndy Lutomirski		  it still contains readable known contents, which could be
2344bd49e16eSAndy Lutomirski		  used in certain rare security vulnerability exploits. This
2345bd49e16eSAndy Lutomirski		  configuration is recommended when using legacy userspace
2346bd49e16eSAndy Lutomirski		  that still uses vsyscalls along with legacy binary
2347bd49e16eSAndy Lutomirski		  instrumentation tools that require code to be readable.
2348bd49e16eSAndy Lutomirski
2349bd49e16eSAndy Lutomirski		  An example of this type of legacy userspace is running
2350bd49e16eSAndy Lutomirski		  Pin on an old binary that still uses vsyscalls.
2351bd49e16eSAndy Lutomirski
2352bd49e16eSAndy Lutomirski	config LEGACY_VSYSCALL_XONLY
2353bd49e16eSAndy Lutomirski		bool "Emulate execution only"
2354bd49e16eSAndy Lutomirski		help
2355bd49e16eSAndy Lutomirski		  The kernel traps and emulates calls into the fixed vsyscall
2356bd49e16eSAndy Lutomirski		  address mapping and does not allow reads.  This
2357bd49e16eSAndy Lutomirski		  configuration is recommended when userspace might use the
2358bd49e16eSAndy Lutomirski		  legacy vsyscall area but support for legacy binary
2359bd49e16eSAndy Lutomirski		  instrumentation of legacy code is not needed.  It mitigates
2360bd49e16eSAndy Lutomirski		  certain uses of the vsyscall area as an ASLR-bypassing
2361bd49e16eSAndy Lutomirski		  buffer.
23623dc33bd3SKees Cook
23633dc33bd3SKees Cook	config LEGACY_VSYSCALL_NONE
23643dc33bd3SKees Cook		bool "None"
23653dc33bd3SKees Cook		help
23663dc33bd3SKees Cook		  There will be no vsyscall mapping at all. This will
23673dc33bd3SKees Cook		  eliminate any risk of ASLR bypass due to the vsyscall
23683dc33bd3SKees Cook		  fixed address mapping. Attempts to use the vsyscalls
23693dc33bd3SKees Cook		  will be reported to dmesg, so that either old or
23703dc33bd3SKees Cook		  malicious userspace programs can be identified.
23713dc33bd3SKees Cook
23723dc33bd3SKees Cookendchoice
23733dc33bd3SKees Cook
2374516cbf37STim Birdconfig CMDLINE_BOOL
2375516cbf37STim Bird	bool "Built-in kernel command line"
2376a7f7f624SMasahiro Yamada	help
2377516cbf37STim Bird	  Allow for specifying boot arguments to the kernel at
2378516cbf37STim Bird	  build time.  On some systems (e.g. embedded ones), it is
2379516cbf37STim Bird	  necessary or convenient to provide some or all of the
2380516cbf37STim Bird	  kernel boot arguments with the kernel itself (that is,
2381516cbf37STim Bird	  to not rely on the boot loader to provide them.)
2382516cbf37STim Bird
2383516cbf37STim Bird	  To compile command line arguments into the kernel,
2384516cbf37STim Bird	  set this option to 'Y', then fill in the
238569711ca1SSébastien Hinderer	  boot arguments in CONFIG_CMDLINE.
2386516cbf37STim Bird
2387516cbf37STim Bird	  Systems with fully functional boot loaders (i.e. non-embedded)
2388516cbf37STim Bird	  should leave this option set to 'N'.
2389516cbf37STim Bird
2390516cbf37STim Birdconfig CMDLINE
2391516cbf37STim Bird	string "Built-in kernel command string"
2392516cbf37STim Bird	depends on CMDLINE_BOOL
2393516cbf37STim Bird	default ""
2394a7f7f624SMasahiro Yamada	help
2395516cbf37STim Bird	  Enter arguments here that should be compiled into the kernel
2396516cbf37STim Bird	  image and used at boot time.  If the boot loader provides a
2397516cbf37STim Bird	  command line at boot time, it is appended to this string to
2398516cbf37STim Bird	  form the full kernel command line, when the system boots.
2399516cbf37STim Bird
2400516cbf37STim Bird	  However, you can use the CONFIG_CMDLINE_OVERRIDE option to
2401516cbf37STim Bird	  change this behavior.
2402516cbf37STim Bird
2403516cbf37STim Bird	  In most cases, the command line (whether built-in or provided
2404516cbf37STim Bird	  by the boot loader) should specify the device for the root
2405516cbf37STim Bird	  file system.
2406516cbf37STim Bird
2407516cbf37STim Birdconfig CMDLINE_OVERRIDE
2408516cbf37STim Bird	bool "Built-in command line overrides boot loader arguments"
2409645e6466SAnders Roxell	depends on CMDLINE_BOOL && CMDLINE != ""
2410a7f7f624SMasahiro Yamada	help
2411516cbf37STim Bird	  Set this option to 'Y' to have the kernel ignore the boot loader
2412516cbf37STim Bird	  command line, and use ONLY the built-in command line.
2413516cbf37STim Bird
2414516cbf37STim Bird	  This is used to work around broken boot loaders.  This should
2415516cbf37STim Bird	  be set to 'N' under normal conditions.
2416516cbf37STim Bird
2417a5b9e5a2SAndy Lutomirskiconfig MODIFY_LDT_SYSCALL
2418a5b9e5a2SAndy Lutomirski	bool "Enable the LDT (local descriptor table)" if EXPERT
2419a5b9e5a2SAndy Lutomirski	default y
2420a7f7f624SMasahiro Yamada	help
2421a5b9e5a2SAndy Lutomirski	  Linux can allow user programs to install a per-process x86
2422a5b9e5a2SAndy Lutomirski	  Local Descriptor Table (LDT) using the modify_ldt(2) system
2423a5b9e5a2SAndy Lutomirski	  call.  This is required to run 16-bit or segmented code such as
2424a5b9e5a2SAndy Lutomirski	  DOSEMU or some Wine programs.  It is also used by some very old
2425a5b9e5a2SAndy Lutomirski	  threading libraries.
2426a5b9e5a2SAndy Lutomirski
2427a5b9e5a2SAndy Lutomirski	  Enabling this feature adds a small amount of overhead to
2428a5b9e5a2SAndy Lutomirski	  context switches and increases the low-level kernel attack
2429a5b9e5a2SAndy Lutomirski	  surface.  Disabling it removes the modify_ldt(2) system call.
2430a5b9e5a2SAndy Lutomirski
2431a5b9e5a2SAndy Lutomirski	  Saying 'N' here may make sense for embedded or server kernels.
2432a5b9e5a2SAndy Lutomirski
24333aac3ebeSThomas Gleixnerconfig STRICT_SIGALTSTACK_SIZE
24343aac3ebeSThomas Gleixner	bool "Enforce strict size checking for sigaltstack"
24353aac3ebeSThomas Gleixner	depends on DYNAMIC_SIGFRAME
24363aac3ebeSThomas Gleixner	help
24373aac3ebeSThomas Gleixner	  For historical reasons MINSIGSTKSZ is a constant which became
24383aac3ebeSThomas Gleixner	  already too small with AVX512 support. Add a mechanism to
24393aac3ebeSThomas Gleixner	  enforce strict checking of the sigaltstack size against the
24403aac3ebeSThomas Gleixner	  real size of the FPU frame. This option enables the check
24413aac3ebeSThomas Gleixner	  by default. It can also be controlled via the kernel command
24423aac3ebeSThomas Gleixner	  line option 'strict_sas_size' independent of this config
24433aac3ebeSThomas Gleixner	  switch. Enabling it might break existing applications which
24443aac3ebeSThomas Gleixner	  allocate a too small sigaltstack but 'work' because they
24453aac3ebeSThomas Gleixner	  never get a signal delivered.
24463aac3ebeSThomas Gleixner
24473aac3ebeSThomas Gleixner	  Say 'N' unless you want to really enforce this check.
24483aac3ebeSThomas Gleixner
2449b700e7f0SSeth Jenningssource "kernel/livepatch/Kconfig"
2450b700e7f0SSeth Jennings
2451506f1d07SSam Ravnborgendmenu
2452506f1d07SSam Ravnborg
24533072e413SMichal Hockoconfig ARCH_HAS_ADD_PAGES
24543072e413SMichal Hocko	def_bool y
24555c11f00bSDavid Hildenbrand	depends on ARCH_ENABLE_MEMORY_HOTPLUG
24563072e413SMichal Hocko
2457f91ef222SOscar Salvadorconfig ARCH_MHP_MEMMAP_ON_MEMORY_ENABLE
2458f91ef222SOscar Salvador	def_bool y
2459f91ef222SOscar Salvador
2460da85f865SBjorn Helgaasmenu "Power management and ACPI options"
2461e279b6c1SSam Ravnborg
2462e279b6c1SSam Ravnborgconfig ARCH_HIBERNATION_HEADER
24633c2362e6SHarvey Harrison	def_bool y
246444556530SZhimin Gu	depends on HIBERNATION
2465e279b6c1SSam Ravnborg
2466e279b6c1SSam Ravnborgsource "kernel/power/Kconfig"
2467e279b6c1SSam Ravnborg
2468e279b6c1SSam Ravnborgsource "drivers/acpi/Kconfig"
2469e279b6c1SSam Ravnborg
2470a6b68076SAndi Kleenconfig X86_APM_BOOT
24716fc108a0SJan Beulich	def_bool y
2472282e5aabSPaul Bolle	depends on APM
2473a6b68076SAndi Kleen
2474e279b6c1SSam Ravnborgmenuconfig APM
2475e279b6c1SSam Ravnborg	tristate "APM (Advanced Power Management) BIOS support"
2476efefa6f6SIngo Molnar	depends on X86_32 && PM_SLEEP
2477a7f7f624SMasahiro Yamada	help
2478e279b6c1SSam Ravnborg	  APM is a BIOS specification for saving power using several different
2479e279b6c1SSam Ravnborg	  techniques. This is mostly useful for battery powered laptops with
2480e279b6c1SSam Ravnborg	  APM compliant BIOSes. If you say Y here, the system time will be
2481e279b6c1SSam Ravnborg	  reset after a RESUME operation, the /proc/apm device will provide
2482e279b6c1SSam Ravnborg	  battery status information, and user-space programs will receive
2483e279b6c1SSam Ravnborg	  notification of APM "events" (e.g. battery status change).
2484e279b6c1SSam Ravnborg
2485e279b6c1SSam Ravnborg	  If you select "Y" here, you can disable actual use of the APM
2486e279b6c1SSam Ravnborg	  BIOS by passing the "apm=off" option to the kernel at boot time.
2487e279b6c1SSam Ravnborg
2488e279b6c1SSam Ravnborg	  Note that the APM support is almost completely disabled for
2489e279b6c1SSam Ravnborg	  machines with more than one CPU.
2490e279b6c1SSam Ravnborg
2491e279b6c1SSam Ravnborg	  In order to use APM, you will need supporting software. For location
2492151f4e2bSMauro Carvalho Chehab	  and more information, read <file:Documentation/power/apm-acpi.rst>
24932dc98fd3SMichael Witten	  and the Battery Powered Linux mini-HOWTO, available from
2494e279b6c1SSam Ravnborg	  <http://www.tldp.org/docs.html#howto>.
2495e279b6c1SSam Ravnborg
2496e279b6c1SSam Ravnborg	  This driver does not spin down disk drives (see the hdparm(8)
2497e279b6c1SSam Ravnborg	  manpage ("man 8 hdparm") for that), and it doesn't turn off
2498e279b6c1SSam Ravnborg	  VESA-compliant "green" monitors.
2499e279b6c1SSam Ravnborg
2500e279b6c1SSam Ravnborg	  This driver does not support the TI 4000M TravelMate and the ACER
2501e279b6c1SSam Ravnborg	  486/DX4/75 because they don't have compliant BIOSes. Many "green"
2502e279b6c1SSam Ravnborg	  desktop machines also don't have compliant BIOSes, and this driver
2503e279b6c1SSam Ravnborg	  may cause those machines to panic during the boot phase.
2504e279b6c1SSam Ravnborg
2505e279b6c1SSam Ravnborg	  Generally, if you don't have a battery in your machine, there isn't
2506e279b6c1SSam Ravnborg	  much point in using this driver and you should say N. If you get
2507e279b6c1SSam Ravnborg	  random kernel OOPSes or reboots that don't seem to be related to
2508e279b6c1SSam Ravnborg	  anything, try disabling/enabling this option (or disabling/enabling
2509e279b6c1SSam Ravnborg	  APM in your BIOS).
2510e279b6c1SSam Ravnborg
2511e279b6c1SSam Ravnborg	  Some other things you should try when experiencing seemingly random,
2512e279b6c1SSam Ravnborg	  "weird" problems:
2513e279b6c1SSam Ravnborg
2514e279b6c1SSam Ravnborg	  1) make sure that you have enough swap space and that it is
2515e279b6c1SSam Ravnborg	  enabled.
2516e279b6c1SSam Ravnborg	  2) pass the "no-hlt" option to the kernel
2517e279b6c1SSam Ravnborg	  3) switch on floating point emulation in the kernel and pass
2518e279b6c1SSam Ravnborg	  the "no387" option to the kernel
2519e279b6c1SSam Ravnborg	  4) pass the "floppy=nodma" option to the kernel
2520e279b6c1SSam Ravnborg	  5) pass the "mem=4M" option to the kernel (thereby disabling
2521e279b6c1SSam Ravnborg	  all but the first 4 MB of RAM)
2522e279b6c1SSam Ravnborg	  6) make sure that the CPU is not over clocked.
2523e279b6c1SSam Ravnborg	  7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/>
2524e279b6c1SSam Ravnborg	  8) disable the cache from your BIOS settings
2525e279b6c1SSam Ravnborg	  9) install a fan for the video card or exchange video RAM
2526e279b6c1SSam Ravnborg	  10) install a better fan for the CPU
2527e279b6c1SSam Ravnborg	  11) exchange RAM chips
2528e279b6c1SSam Ravnborg	  12) exchange the motherboard.
2529e279b6c1SSam Ravnborg
2530e279b6c1SSam Ravnborg	  To compile this driver as a module, choose M here: the
2531e279b6c1SSam Ravnborg	  module will be called apm.
2532e279b6c1SSam Ravnborg
2533e279b6c1SSam Ravnborgif APM
2534e279b6c1SSam Ravnborg
2535e279b6c1SSam Ravnborgconfig APM_IGNORE_USER_SUSPEND
2536e279b6c1SSam Ravnborg	bool "Ignore USER SUSPEND"
2537a7f7f624SMasahiro Yamada	help
2538e279b6c1SSam Ravnborg	  This option will ignore USER SUSPEND requests. On machines with a
2539e279b6c1SSam Ravnborg	  compliant APM BIOS, you want to say N. However, on the NEC Versa M
2540e279b6c1SSam Ravnborg	  series notebooks, it is necessary to say Y because of a BIOS bug.
2541e279b6c1SSam Ravnborg
2542e279b6c1SSam Ravnborgconfig APM_DO_ENABLE
2543e279b6c1SSam Ravnborg	bool "Enable PM at boot time"
2544a7f7f624SMasahiro Yamada	help
2545e279b6c1SSam Ravnborg	  Enable APM features at boot time. From page 36 of the APM BIOS
2546e279b6c1SSam Ravnborg	  specification: "When disabled, the APM BIOS does not automatically
2547e279b6c1SSam Ravnborg	  power manage devices, enter the Standby State, enter the Suspend
2548e279b6c1SSam Ravnborg	  State, or take power saving steps in response to CPU Idle calls."
2549e279b6c1SSam Ravnborg	  This driver will make CPU Idle calls when Linux is idle (unless this
2550e279b6c1SSam Ravnborg	  feature is turned off -- see "Do CPU IDLE calls", below). This
2551e279b6c1SSam Ravnborg	  should always save battery power, but more complicated APM features
2552e279b6c1SSam Ravnborg	  will be dependent on your BIOS implementation. You may need to turn
2553e279b6c1SSam Ravnborg	  this option off if your computer hangs at boot time when using APM
2554e279b6c1SSam Ravnborg	  support, or if it beeps continuously instead of suspending. Turn
2555e279b6c1SSam Ravnborg	  this off if you have a NEC UltraLite Versa 33/C or a Toshiba
2556e279b6c1SSam Ravnborg	  T400CDT. This is off by default since most machines do fine without
2557e279b6c1SSam Ravnborg	  this feature.
2558e279b6c1SSam Ravnborg
2559e279b6c1SSam Ravnborgconfig APM_CPU_IDLE
2560dd8af076SLen Brown	depends on CPU_IDLE
2561e279b6c1SSam Ravnborg	bool "Make CPU Idle calls when idle"
2562a7f7f624SMasahiro Yamada	help
2563e279b6c1SSam Ravnborg	  Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop.
2564e279b6c1SSam Ravnborg	  On some machines, this can activate improved power savings, such as
2565e279b6c1SSam Ravnborg	  a slowed CPU clock rate, when the machine is idle. These idle calls
2566e279b6c1SSam Ravnborg	  are made after the idle loop has run for some length of time (e.g.,
2567e279b6c1SSam Ravnborg	  333 mS). On some machines, this will cause a hang at boot time or
2568e279b6c1SSam Ravnborg	  whenever the CPU becomes idle. (On machines with more than one CPU,
2569e279b6c1SSam Ravnborg	  this option does nothing.)
2570e279b6c1SSam Ravnborg
2571e279b6c1SSam Ravnborgconfig APM_DISPLAY_BLANK
2572e279b6c1SSam Ravnborg	bool "Enable console blanking using APM"
2573a7f7f624SMasahiro Yamada	help
2574e279b6c1SSam Ravnborg	  Enable console blanking using the APM. Some laptops can use this to
2575e279b6c1SSam Ravnborg	  turn off the LCD backlight when the screen blanker of the Linux
2576e279b6c1SSam Ravnborg	  virtual console blanks the screen. Note that this is only used by
2577e279b6c1SSam Ravnborg	  the virtual console screen blanker, and won't turn off the backlight
2578e279b6c1SSam Ravnborg	  when using the X Window system. This also doesn't have anything to
2579e279b6c1SSam Ravnborg	  do with your VESA-compliant power-saving monitor. Further, this
2580e279b6c1SSam Ravnborg	  option doesn't work for all laptops -- it might not turn off your
2581e279b6c1SSam Ravnborg	  backlight at all, or it might print a lot of errors to the console,
2582e279b6c1SSam Ravnborg	  especially if you are using gpm.
2583e279b6c1SSam Ravnborg
2584e279b6c1SSam Ravnborgconfig APM_ALLOW_INTS
2585e279b6c1SSam Ravnborg	bool "Allow interrupts during APM BIOS calls"
2586a7f7f624SMasahiro Yamada	help
2587e279b6c1SSam Ravnborg	  Normally we disable external interrupts while we are making calls to
2588e279b6c1SSam Ravnborg	  the APM BIOS as a measure to lessen the effects of a badly behaving
2589e279b6c1SSam Ravnborg	  BIOS implementation.  The BIOS should reenable interrupts if it
2590e279b6c1SSam Ravnborg	  needs to.  Unfortunately, some BIOSes do not -- especially those in
2591e279b6c1SSam Ravnborg	  many of the newer IBM Thinkpads.  If you experience hangs when you
2592e279b6c1SSam Ravnborg	  suspend, try setting this to Y.  Otherwise, say N.
2593e279b6c1SSam Ravnborg
2594e279b6c1SSam Ravnborgendif # APM
2595e279b6c1SSam Ravnborg
2596bb0a56ecSDave Jonessource "drivers/cpufreq/Kconfig"
2597e279b6c1SSam Ravnborg
2598e279b6c1SSam Ravnborgsource "drivers/cpuidle/Kconfig"
2599e279b6c1SSam Ravnborg
260027471fdbSAndy Henroidsource "drivers/idle/Kconfig"
260127471fdbSAndy Henroid
2602e279b6c1SSam Ravnborgendmenu
2603e279b6c1SSam Ravnborg
2604e279b6c1SSam Ravnborg
2605e279b6c1SSam Ravnborgmenu "Bus options (PCI etc.)"
2606e279b6c1SSam Ravnborg
2607e279b6c1SSam Ravnborgchoice
2608e279b6c1SSam Ravnborg	prompt "PCI access mode"
2609efefa6f6SIngo Molnar	depends on X86_32 && PCI
2610e279b6c1SSam Ravnborg	default PCI_GOANY
2611a7f7f624SMasahiro Yamada	help
2612e279b6c1SSam Ravnborg	  On PCI systems, the BIOS can be used to detect the PCI devices and
2613e279b6c1SSam Ravnborg	  determine their configuration. However, some old PCI motherboards
2614e279b6c1SSam Ravnborg	  have BIOS bugs and may crash if this is done. Also, some embedded
2615e279b6c1SSam Ravnborg	  PCI-based systems don't have any BIOS at all. Linux can also try to
2616e279b6c1SSam Ravnborg	  detect the PCI hardware directly without using the BIOS.
2617e279b6c1SSam Ravnborg
2618e279b6c1SSam Ravnborg	  With this option, you can specify how Linux should detect the
2619e279b6c1SSam Ravnborg	  PCI devices. If you choose "BIOS", the BIOS will be used,
2620e279b6c1SSam Ravnborg	  if you choose "Direct", the BIOS won't be used, and if you
2621e279b6c1SSam Ravnborg	  choose "MMConfig", then PCI Express MMCONFIG will be used.
2622e279b6c1SSam Ravnborg	  If you choose "Any", the kernel will try MMCONFIG, then the
2623e279b6c1SSam Ravnborg	  direct access method and falls back to the BIOS if that doesn't
2624e279b6c1SSam Ravnborg	  work. If unsure, go with the default, which is "Any".
2625e279b6c1SSam Ravnborg
2626e279b6c1SSam Ravnborgconfig PCI_GOBIOS
2627e279b6c1SSam Ravnborg	bool "BIOS"
2628e279b6c1SSam Ravnborg
2629e279b6c1SSam Ravnborgconfig PCI_GOMMCONFIG
2630e279b6c1SSam Ravnborg	bool "MMConfig"
2631e279b6c1SSam Ravnborg
2632e279b6c1SSam Ravnborgconfig PCI_GODIRECT
2633e279b6c1SSam Ravnborg	bool "Direct"
2634e279b6c1SSam Ravnborg
26353ef0e1f8SAndres Salomonconfig PCI_GOOLPC
263676fb6570SDaniel Drake	bool "OLPC XO-1"
26373ef0e1f8SAndres Salomon	depends on OLPC
26383ef0e1f8SAndres Salomon
26392bdd1b03SAndres Salomonconfig PCI_GOANY
26402bdd1b03SAndres Salomon	bool "Any"
26412bdd1b03SAndres Salomon
2642e279b6c1SSam Ravnborgendchoice
2643e279b6c1SSam Ravnborg
2644e279b6c1SSam Ravnborgconfig PCI_BIOS
26453c2362e6SHarvey Harrison	def_bool y
2646efefa6f6SIngo Molnar	depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY)
2647e279b6c1SSam Ravnborg
2648e279b6c1SSam Ravnborg# x86-64 doesn't support PCI BIOS access from long mode so always go direct.
2649e279b6c1SSam Ravnborgconfig PCI_DIRECT
26503c2362e6SHarvey Harrison	def_bool y
26510aba496fSShaohua Li	depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC || PCI_GOMMCONFIG))
2652e279b6c1SSam Ravnborg
2653e279b6c1SSam Ravnborgconfig PCI_MMCONFIG
2654b45c9f36SJan Kiszka	bool "Support mmconfig PCI config space access" if X86_64
2655b45c9f36SJan Kiszka	default y
26564590d98fSAndy Shevchenko	depends on PCI && (ACPI || JAILHOUSE_GUEST)
2657b45c9f36SJan Kiszka	depends on X86_64 || (PCI_GOANY || PCI_GOMMCONFIG)
2658e279b6c1SSam Ravnborg
26593ef0e1f8SAndres Salomonconfig PCI_OLPC
26602bdd1b03SAndres Salomon	def_bool y
26612bdd1b03SAndres Salomon	depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY)
26623ef0e1f8SAndres Salomon
2663b5401a96SAlex Nixonconfig PCI_XEN
2664b5401a96SAlex Nixon	def_bool y
2665b5401a96SAlex Nixon	depends on PCI && XEN
2666b5401a96SAlex Nixon
26678364e1f8SJan Kiszkaconfig MMCONF_FAM10H
26688364e1f8SJan Kiszka	def_bool y
26698364e1f8SJan Kiszka	depends on X86_64 && PCI_MMCONFIG && ACPI
2670e279b6c1SSam Ravnborg
26713f6ea84aSIra W. Snyderconfig PCI_CNB20LE_QUIRK
26726a108a14SDavid Rientjes	bool "Read CNB20LE Host Bridge Windows" if EXPERT
26736ea30386SKees Cook	depends on PCI
26743f6ea84aSIra W. Snyder	help
26753f6ea84aSIra W. Snyder	  Read the PCI windows out of the CNB20LE host bridge. This allows
26763f6ea84aSIra W. Snyder	  PCI hotplug to work on systems with the CNB20LE chipset which do
26773f6ea84aSIra W. Snyder	  not have ACPI.
26783f6ea84aSIra W. Snyder
267964a5fed6SBjorn Helgaas	  There's no public spec for this chipset, and this functionality
268064a5fed6SBjorn Helgaas	  is known to be incomplete.
268164a5fed6SBjorn Helgaas
268264a5fed6SBjorn Helgaas	  You should say N unless you know you need this.
268364a5fed6SBjorn Helgaas
26843a495511SWilliam Breathitt Grayconfig ISA_BUS
268517a2a129SWilliam Breathitt Gray	bool "ISA bus support on modern systems" if EXPERT
26863a495511SWilliam Breathitt Gray	help
268717a2a129SWilliam Breathitt Gray	  Expose ISA bus device drivers and options available for selection and
268817a2a129SWilliam Breathitt Gray	  configuration. Enable this option if your target machine has an ISA
268917a2a129SWilliam Breathitt Gray	  bus. ISA is an older system, displaced by PCI and newer bus
269017a2a129SWilliam Breathitt Gray	  architectures -- if your target machine is modern, it probably does
269117a2a129SWilliam Breathitt Gray	  not have an ISA bus.
26923a495511SWilliam Breathitt Gray
26933a495511SWilliam Breathitt Gray	  If unsure, say N.
26943a495511SWilliam Breathitt Gray
26951c00f016SDavid Rientjes# x86_64 have no ISA slots, but can have ISA-style DMA.
2696e279b6c1SSam Ravnborgconfig ISA_DMA_API
26971c00f016SDavid Rientjes	bool "ISA-style DMA support" if (X86_64 && EXPERT)
26981c00f016SDavid Rientjes	default y
26991c00f016SDavid Rientjes	help
27001c00f016SDavid Rientjes	  Enables ISA-style DMA support for devices requiring such controllers.
27011c00f016SDavid Rientjes	  If unsure, say Y.
2702e279b6c1SSam Ravnborg
270351e68d05SLinus Torvaldsif X86_32
270451e68d05SLinus Torvalds
2705e279b6c1SSam Ravnborgconfig ISA
2706e279b6c1SSam Ravnborg	bool "ISA support"
2707a7f7f624SMasahiro Yamada	help
2708e279b6c1SSam Ravnborg	  Find out whether you have ISA slots on your motherboard.  ISA is the
2709e279b6c1SSam Ravnborg	  name of a bus system, i.e. the way the CPU talks to the other stuff
2710e279b6c1SSam Ravnborg	  inside your box.  Other bus systems are PCI, EISA, MicroChannel
2711e279b6c1SSam Ravnborg	  (MCA) or VESA.  ISA is an older system, now being displaced by PCI;
2712e279b6c1SSam Ravnborg	  newer boards don't support it.  If you have ISA, say Y, otherwise N.
2713e279b6c1SSam Ravnborg
2714e279b6c1SSam Ravnborgconfig SCx200
2715e279b6c1SSam Ravnborg	tristate "NatSemi SCx200 support"
2716a7f7f624SMasahiro Yamada	help
2717e279b6c1SSam Ravnborg	  This provides basic support for National Semiconductor's
2718e279b6c1SSam Ravnborg	  (now AMD's) Geode processors.  The driver probes for the
2719e279b6c1SSam Ravnborg	  PCI-IDs of several on-chip devices, so its a good dependency
2720e279b6c1SSam Ravnborg	  for other scx200_* drivers.
2721e279b6c1SSam Ravnborg
2722e279b6c1SSam Ravnborg	  If compiled as a module, the driver is named scx200.
2723e279b6c1SSam Ravnborg
2724e279b6c1SSam Ravnborgconfig SCx200HR_TIMER
2725e279b6c1SSam Ravnborg	tristate "NatSemi SCx200 27MHz High-Resolution Timer Support"
2726592913ecSJohn Stultz	depends on SCx200
2727e279b6c1SSam Ravnborg	default y
2728a7f7f624SMasahiro Yamada	help
2729e279b6c1SSam Ravnborg	  This driver provides a clocksource built upon the on-chip
2730e279b6c1SSam Ravnborg	  27MHz high-resolution timer.  Its also a workaround for
2731e279b6c1SSam Ravnborg	  NSC Geode SC-1100's buggy TSC, which loses time when the
2732e279b6c1SSam Ravnborg	  processor goes idle (as is done by the scheduler).  The
2733e279b6c1SSam Ravnborg	  other workaround is idle=poll boot option.
2734e279b6c1SSam Ravnborg
27353ef0e1f8SAndres Salomonconfig OLPC
27363ef0e1f8SAndres Salomon	bool "One Laptop Per Child support"
273754008979SThomas Gleixner	depends on !X86_PAE
27383c554946SAndres Salomon	select GPIOLIB
2739dc3119e7SThomas Gleixner	select OF
274045bb1674SDaniel Drake	select OF_PROMTREE
2741b4e51854SGrant Likely	select IRQ_DOMAIN
27420c3d931bSLubomir Rintel	select OLPC_EC
2743a7f7f624SMasahiro Yamada	help
27443ef0e1f8SAndres Salomon	  Add support for detecting the unique features of the OLPC
27453ef0e1f8SAndres Salomon	  XO hardware.
27463ef0e1f8SAndres Salomon
2747a3128588SDaniel Drakeconfig OLPC_XO1_PM
2748a3128588SDaniel Drake	bool "OLPC XO-1 Power Management"
2749fa112cf1SBorislav Petkov	depends on OLPC && MFD_CS5535=y && PM_SLEEP
2750a7f7f624SMasahiro Yamada	help
275197c4cb71SDaniel Drake	  Add support for poweroff and suspend of the OLPC XO-1 laptop.
2752bf1ebf00SDaniel Drake
2753cfee9597SDaniel Drakeconfig OLPC_XO1_RTC
2754cfee9597SDaniel Drake	bool "OLPC XO-1 Real Time Clock"
2755cfee9597SDaniel Drake	depends on OLPC_XO1_PM && RTC_DRV_CMOS
2756a7f7f624SMasahiro Yamada	help
2757cfee9597SDaniel Drake	  Add support for the XO-1 real time clock, which can be used as a
2758cfee9597SDaniel Drake	  programmable wakeup source.
2759cfee9597SDaniel Drake
27607feda8e9SDaniel Drakeconfig OLPC_XO1_SCI
27617feda8e9SDaniel Drake	bool "OLPC XO-1 SCI extras"
276292e830f2SArnd Bergmann	depends on OLPC && OLPC_XO1_PM && GPIO_CS5535=y
2763ed8e47feSRandy Dunlap	depends on INPUT=y
2764d8d01a63SDaniel Drake	select POWER_SUPPLY
2765a7f7f624SMasahiro Yamada	help
27667feda8e9SDaniel Drake	  Add support for SCI-based features of the OLPC XO-1 laptop:
27677bc74b3dSDaniel Drake	   - EC-driven system wakeups
27687feda8e9SDaniel Drake	   - Power button
27697bc74b3dSDaniel Drake	   - Ebook switch
27702cf2baeaSDaniel Drake	   - Lid switch
2771e1040ac6SDaniel Drake	   - AC adapter status updates
2772e1040ac6SDaniel Drake	   - Battery status updates
27737feda8e9SDaniel Drake
2774a0f30f59SDaniel Drakeconfig OLPC_XO15_SCI
2775a0f30f59SDaniel Drake	bool "OLPC XO-1.5 SCI extras"
2776d8d01a63SDaniel Drake	depends on OLPC && ACPI
2777d8d01a63SDaniel Drake	select POWER_SUPPLY
2778a7f7f624SMasahiro Yamada	help
2779a0f30f59SDaniel Drake	  Add support for SCI-based features of the OLPC XO-1.5 laptop:
2780a0f30f59SDaniel Drake	   - EC-driven system wakeups
2781a0f30f59SDaniel Drake	   - AC adapter status updates
2782a0f30f59SDaniel Drake	   - Battery status updates
2783e279b6c1SSam Ravnborg
2784d4f3e350SEd Wildgooseconfig ALIX
2785d4f3e350SEd Wildgoose	bool "PCEngines ALIX System Support (LED setup)"
2786d4f3e350SEd Wildgoose	select GPIOLIB
2787a7f7f624SMasahiro Yamada	help
2788d4f3e350SEd Wildgoose	  This option enables system support for the PCEngines ALIX.
2789d4f3e350SEd Wildgoose	  At present this just sets up LEDs for GPIO control on
2790d4f3e350SEd Wildgoose	  ALIX2/3/6 boards.  However, other system specific setup should
2791d4f3e350SEd Wildgoose	  get added here.
2792d4f3e350SEd Wildgoose
2793d4f3e350SEd Wildgoose	  Note: You must still enable the drivers for GPIO and LED support
2794d4f3e350SEd Wildgoose	  (GPIO_CS5535 & LEDS_GPIO) to actually use the LEDs
2795d4f3e350SEd Wildgoose
2796d4f3e350SEd Wildgoose	  Note: You have to set alix.force=1 for boards with Award BIOS.
2797d4f3e350SEd Wildgoose
2798da4e3302SPhilip Prindevilleconfig NET5501
2799da4e3302SPhilip Prindeville	bool "Soekris Engineering net5501 System Support (LEDS, GPIO, etc)"
2800da4e3302SPhilip Prindeville	select GPIOLIB
2801a7f7f624SMasahiro Yamada	help
2802da4e3302SPhilip Prindeville	  This option enables system support for the Soekris Engineering net5501.
2803da4e3302SPhilip Prindeville
28043197059aSPhilip A. Prindevilleconfig GEOS
28053197059aSPhilip A. Prindeville	bool "Traverse Technologies GEOS System Support (LEDS, GPIO, etc)"
28063197059aSPhilip A. Prindeville	select GPIOLIB
28073197059aSPhilip A. Prindeville	depends on DMI
2808a7f7f624SMasahiro Yamada	help
28093197059aSPhilip A. Prindeville	  This option enables system support for the Traverse Technologies GEOS.
28103197059aSPhilip A. Prindeville
28117d029125SVivien Didelotconfig TS5500
28127d029125SVivien Didelot	bool "Technologic Systems TS-5500 platform support"
28137d029125SVivien Didelot	depends on MELAN
28147d029125SVivien Didelot	select CHECK_SIGNATURE
28157d029125SVivien Didelot	select NEW_LEDS
28167d029125SVivien Didelot	select LEDS_CLASS
2817a7f7f624SMasahiro Yamada	help
28187d029125SVivien Didelot	  This option enables system support for the Technologic Systems TS-5500.
28197d029125SVivien Didelot
2820e279b6c1SSam Ravnborgendif # X86_32
2821e279b6c1SSam Ravnborg
282223ac4ae8SAndreas Herrmannconfig AMD_NB
2823e279b6c1SSam Ravnborg	def_bool y
28240e152cd7SBorislav Petkov	depends on CPU_SUP_AMD && PCI
2825e279b6c1SSam Ravnborg
2826e279b6c1SSam Ravnborgendmenu
2827e279b6c1SSam Ravnborg
2828e279b6c1SSam Ravnborg
28291572497cSChristoph Hellwigmenu "Binary Emulations"
2830e279b6c1SSam Ravnborg
2831e279b6c1SSam Ravnborgconfig IA32_EMULATION
2832e279b6c1SSam Ravnborg	bool "IA32 Emulation"
2833e279b6c1SSam Ravnborg	depends on X86_64
283439f88911SIngo Molnar	select ARCH_WANT_OLD_COMPAT_IPC
2835d1603990SRandy Dunlap	select BINFMT_ELF
283639f88911SIngo Molnar	select COMPAT_OLD_SIGACTION
2837a7f7f624SMasahiro Yamada	help
28385fd92e65SH. J. Lu	  Include code to run legacy 32-bit programs under a
28395fd92e65SH. J. Lu	  64-bit kernel. You should likely turn this on, unless you're
28405fd92e65SH. J. Lu	  100% sure that you don't have any 32-bit programs left.
2841e279b6c1SSam Ravnborg
2842e279b6c1SSam Ravnborgconfig IA32_AOUT
2843e279b6c1SSam Ravnborg	tristate "IA32 a.out support"
28446b213e1bSDavid Woodhouse	depends on IA32_EMULATION
2845eac61655SBorislav Petkov	depends on BROKEN
2846a7f7f624SMasahiro Yamada	help
2847e279b6c1SSam Ravnborg	  Support old a.out binaries in the 32bit emulation.
2848e279b6c1SSam Ravnborg
284983a44a4fSMasahiro Yamadaconfig X86_X32_ABI
28506ea30386SKees Cook	bool "x32 ABI for 64-bit mode"
28519b54050bSBrian Gerst	depends on X86_64
2852aaeed6ecSNathan Chancellor	# llvm-objcopy does not convert x86_64 .note.gnu.property or
2853aaeed6ecSNathan Chancellor	# compressed debug sections to x86_x32 properly:
2854aaeed6ecSNathan Chancellor	# https://github.com/ClangBuiltLinux/linux/issues/514
2855aaeed6ecSNathan Chancellor	# https://github.com/ClangBuiltLinux/linux/issues/1141
2856aaeed6ecSNathan Chancellor	depends on $(success,$(OBJCOPY) --version | head -n1 | grep -qv llvm)
2857a7f7f624SMasahiro Yamada	help
28585fd92e65SH. J. Lu	  Include code to run binaries for the x32 native 32-bit ABI
28595fd92e65SH. J. Lu	  for 64-bit processors.  An x32 process gets access to the
28605fd92e65SH. J. Lu	  full 64-bit register file and wide data path while leaving
28615fd92e65SH. J. Lu	  pointers at 32 bits for smaller memory footprint.
28625fd92e65SH. J. Lu
2863953fee1dSIngo Molnarconfig COMPAT_32
2864953fee1dSIngo Molnar	def_bool y
2865953fee1dSIngo Molnar	depends on IA32_EMULATION || X86_32
2866953fee1dSIngo Molnar	select HAVE_UID16
2867953fee1dSIngo Molnar	select OLD_SIGSUSPEND3
2868953fee1dSIngo Molnar
2869e279b6c1SSam Ravnborgconfig COMPAT
28703c2362e6SHarvey Harrison	def_bool y
287183a44a4fSMasahiro Yamada	depends on IA32_EMULATION || X86_X32_ABI
2872e279b6c1SSam Ravnborg
28733120e25eSJan Beulichif COMPAT
2874e279b6c1SSam Ravnborgconfig COMPAT_FOR_U64_ALIGNMENT
28753120e25eSJan Beulich	def_bool y
2876e279b6c1SSam Ravnborg
2877e279b6c1SSam Ravnborgconfig SYSVIPC_COMPAT
28783c2362e6SHarvey Harrison	def_bool y
28793120e25eSJan Beulich	depends on SYSVIPC
28803120e25eSJan Beulichendif
2881ee009e4aSDavid Howells
2882e279b6c1SSam Ravnborgendmenu
2883e279b6c1SSam Ravnborg
2884e279b6c1SSam Ravnborg
2885e5beae16SKeith Packardconfig HAVE_ATOMIC_IOMAP
2886e5beae16SKeith Packard	def_bool y
2887e5beae16SKeith Packard	depends on X86_32
2888e5beae16SKeith Packard
2889edf88417SAvi Kivitysource "arch/x86/kvm/Kconfig"
28905e8ebd84SJason A. Donenfeld
28915e8ebd84SJason A. Donenfeldsource "arch/x86/Kconfig.assembler"
2892