xref: /linux/arch/x86/Kconfig (revision 3228e1dc80983ee1f5d2e533d010b3bd8b50f0e2)
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
22daa93fabSSam Ravnborg
23daa93fabSSam Ravnborgconfig X86_64
243120e25eSJan Beulich	def_bool y
253120e25eSJan Beulich	depends on 64BIT
26d94e0685SIngo Molnar	# Options that are inherently 64-bit kernel only:
274eb0716eSAlexandre Ghiti	select ARCH_HAS_GIGANTIC_PAGE
28c12d3362SArd Biesheuvel	select ARCH_SUPPORTS_INT128 if CC_HAS_INT128
29d94e0685SIngo Molnar	select ARCH_USE_CMPXCHG_LOCKREF
30d94e0685SIngo Molnar	select HAVE_ARCH_SOFT_DIRTY
31d94e0685SIngo Molnar	select MODULES_USE_ELF_RELA
32f616ab59SChristoph Hellwig	select NEED_DMA_MAP_STATE
3309230cbcSChristoph Hellwig	select SWIOTLB
341032c0baSSam Ravnborg
35518049d9SSteven Rostedt (VMware)config FORCE_DYNAMIC_FTRACE
36518049d9SSteven Rostedt (VMware)	def_bool y
37518049d9SSteven Rostedt (VMware)	depends on X86_32
38518049d9SSteven Rostedt (VMware)	depends on FUNCTION_TRACER
39518049d9SSteven Rostedt (VMware)	select DYNAMIC_FTRACE
40518049d9SSteven Rostedt (VMware)	help
41518049d9SSteven Rostedt (VMware)	 We keep the static function tracing (!DYNAMIC_FTRACE) around
42518049d9SSteven Rostedt (VMware)	 in order to test the non static function tracing in the
43518049d9SSteven Rostedt (VMware)	 generic code, as other architectures still use it. But we
44518049d9SSteven Rostedt (VMware)	 only need to keep it around for x86_64. No need to keep it
45518049d9SSteven Rostedt (VMware)	 for x86_32. For x86_32, force DYNAMIC_FTRACE.
46d94e0685SIngo Molnar#
47d94e0685SIngo Molnar# Arch settings
48d94e0685SIngo Molnar#
49d94e0685SIngo Molnar# ( Note that options that are marked 'if X86_64' could in principle be
50d94e0685SIngo Molnar#   ported to 32-bit as well. )
51d94e0685SIngo Molnar#
528d5fffb9SSam Ravnborgconfig X86
533c2362e6SHarvey Harrison	def_bool y
54c763ea26SIngo Molnar	#
55c763ea26SIngo Molnar	# Note: keep this list sorted alphabetically
56c763ea26SIngo Molnar	#
576471b825SIngo Molnar	select ACPI_LEGACY_TABLES_LOOKUP	if ACPI
586e0a0ea1SGraeme Gregory	select ACPI_SYSTEM_POWER_STATES_SUPPORT	if ACPI
59942fa985SYury Norov	select ARCH_32BIT_OFF_T			if X86_32
602a21ad57SThomas Gleixner	select ARCH_CLOCKSOURCE_INIT
6191dda51aSAleksey Makarov	select ARCH_HAS_ACPI_TABLE_UPGRADE	if ACPI
62fa5b6ec9SLaura Abbott	select ARCH_HAS_DEBUG_VIRTUAL
63399145f9SAnshuman Khandual	select ARCH_HAS_DEBUG_VM_PGTABLE	if !X86_PAE
6421266be9SDan Williams	select ARCH_HAS_DEVMEM_IS_ALLOWED
65b1a57bbfSDouglas Anderson	select ARCH_HAS_EARLY_DEBUG		if KGDB
666471b825SIngo Molnar	select ARCH_HAS_ELF_RANDOMIZE
6772d93104SLinus Torvalds	select ARCH_HAS_FAST_MULTIPLIER
68316d097cSDave Hansen	select ARCH_HAS_FILTER_PGPROT
696974f0c4SDaniel Micay	select ARCH_HAS_FORTIFY_SOURCE
70957e3facSRiku Voipio	select ARCH_HAS_GCOV_PROFILE_ALL
710f1441b4SPeter Zijlstra	select ARCH_HAS_KCOV			if X86_64 && STACK_VALIDATION
720c9c1d56SThiago Jung Bauermann	select ARCH_HAS_MEM_ENCRYPT
7310bcc80eSMathieu Desnoyers	select ARCH_HAS_MEMBARRIER_SYNC_CORE
740ebeea8cSDaniel Borkmann	select ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE
75c763ea26SIngo Molnar	select ARCH_HAS_PMEM_API		if X86_64
7617596731SRobin Murphy	select ARCH_HAS_PTE_DEVMAP		if X86_64
773010a5eaSLaurent Dufour	select ARCH_HAS_PTE_SPECIAL
780aed55afSDan Williams	select ARCH_HAS_UACCESS_FLUSHCACHE	if X86_64
79ec6347bbSDan Williams	select ARCH_HAS_COPY_MC			if X86_64
80d2852a22SDaniel Borkmann	select ARCH_HAS_SET_MEMORY
81d253ca0cSRick Edgecombe	select ARCH_HAS_SET_DIRECT_MAP
82ad21fc4fSLaura Abbott	select ARCH_HAS_STRICT_KERNEL_RWX
83ad21fc4fSLaura Abbott	select ARCH_HAS_STRICT_MODULE_RWX
84ac1ab12aSMathieu Desnoyers	select ARCH_HAS_SYNC_CORE_BEFORE_USERMODE
8525c619e5SBrian Gerst	select ARCH_HAS_SYSCALL_WRAPPER
86c6d30853SAndrey Ryabinin	select ARCH_HAS_UBSAN_SANITIZE_ALL
877e01ccb4SZong Li	select ARCH_HAS_DEBUG_WX
886471b825SIngo Molnar	select ARCH_HAVE_NMI_SAFE_CMPXCHG
896471b825SIngo Molnar	select ARCH_MIGHT_HAVE_ACPI_PDC		if ACPI
9077fbbc81SMark Salter	select ARCH_MIGHT_HAVE_PC_PARPORT
915e2c18c0SMark Salter	select ARCH_MIGHT_HAVE_PC_SERIO
923599fe12SThomas Gleixner	select ARCH_STACKWALK
932c870e61SArnd Bergmann	select ARCH_SUPPORTS_ACPI
946471b825SIngo Molnar	select ARCH_SUPPORTS_ATOMIC_RMW
955d6ad668SMike Rapoport	select ARCH_SUPPORTS_DEBUG_PAGEALLOC
966471b825SIngo Molnar	select ARCH_SUPPORTS_NUMA_BALANCING	if X86_64
9714df3267SThomas Gleixner	select ARCH_SUPPORTS_KMAP_LOCAL_FORCE_MAP	if NR_CPUS <= 4096
986471b825SIngo Molnar	select ARCH_USE_BUILTIN_BSWAP
996471b825SIngo Molnar	select ARCH_USE_QUEUED_RWLOCKS
1006471b825SIngo Molnar	select ARCH_USE_QUEUED_SPINLOCKS
1012ce0d7f9SMark Brown	select ARCH_USE_SYM_ANNOTATIONS
102ce4a4e56SAndy Lutomirski	select ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH
10381c22041SDaniel Borkmann	select ARCH_WANT_DEFAULT_BPF_JIT	if X86_64
104c763ea26SIngo Molnar	select ARCH_WANTS_DYNAMIC_TASK_STRUCT
1053876d4a3SAlexandre Ghiti	select ARCH_WANT_HUGE_PMD_SHARE
10659612b24SNathan Chancellor	select ARCH_WANT_LD_ORPHAN_WARN
10738d8b4e6SHuang Ying	select ARCH_WANTS_THP_SWAP		if X86_64
10810916706SShile Zhang	select BUILDTIME_TABLE_SORT
1096471b825SIngo Molnar	select CLKEVT_I8253
1106471b825SIngo Molnar	select CLOCKSOURCE_VALIDATE_LAST_CYCLE
1116471b825SIngo Molnar	select CLOCKSOURCE_WATCHDOG
1126471b825SIngo Molnar	select DCACHE_WORD_ACCESS
11345471cd9SLinus Torvalds	select EDAC_ATOMIC_SCRUB
11445471cd9SLinus Torvalds	select EDAC_SUPPORT
1156471b825SIngo Molnar	select GENERIC_CLOCKEVENTS_BROADCAST	if X86_64 || (X86_32 && X86_LOCAL_APIC)
1166471b825SIngo Molnar	select GENERIC_CLOCKEVENTS_MIN_ADJUST
1176471b825SIngo Molnar	select GENERIC_CMOS_UPDATE
1186471b825SIngo Molnar	select GENERIC_CPU_AUTOPROBE
11961dc0f55SThomas Gleixner	select GENERIC_CPU_VULNERABILITIES
1206471b825SIngo Molnar	select GENERIC_EARLY_IOREMAP
12127d6b4d1SThomas Gleixner	select GENERIC_ENTRY
1226471b825SIngo Molnar	select GENERIC_FIND_FIRST_BIT
1236471b825SIngo Molnar	select GENERIC_IOMAP
124c7d6c9ddSThomas Gleixner	select GENERIC_IRQ_EFFECTIVE_AFF_MASK	if SMP
1250fa115daSThomas Gleixner	select GENERIC_IRQ_MATRIX_ALLOCATOR	if X86_LOCAL_APIC
126ad7a929fSThomas Gleixner	select GENERIC_IRQ_MIGRATION		if SMP
1276471b825SIngo Molnar	select GENERIC_IRQ_PROBE
128c201c917SThomas Gleixner	select GENERIC_IRQ_RESERVATION_MODE
1296471b825SIngo Molnar	select GENERIC_IRQ_SHOW
1306471b825SIngo Molnar	select GENERIC_PENDING_IRQ		if SMP
1312ae27137SSteven Price	select GENERIC_PTDUMP
1326471b825SIngo Molnar	select GENERIC_SMP_IDLE_THREAD
1336471b825SIngo Molnar	select GENERIC_STRNCPY_FROM_USER
1346471b825SIngo Molnar	select GENERIC_STRNLEN_USER
1356471b825SIngo Molnar	select GENERIC_TIME_VSYSCALL
1367ac87074SVincenzo Frascino	select GENERIC_GETTIMEOFDAY
137550a77a7SDmitry Safonov	select GENERIC_VDSO_TIME_NS
13839656e83SChristoph Hellwig	select GUP_GET_PTE_LOW_HIGH		if X86_PAE
13917e5888eSHans de Goede	select HARDIRQS_SW_RESEND
1407edaeb68SThomas Gleixner	select HARDLOCKUP_CHECK_TIMESTAMP	if X86_64
1416471b825SIngo Molnar	select HAVE_ACPI_APEI			if ACPI
1426471b825SIngo Molnar	select HAVE_ACPI_APEI_NMI		if ACPI
1436471b825SIngo Molnar	select HAVE_ALIGNED_STRUCT_PAGE		if SLUB
1446471b825SIngo Molnar	select HAVE_ARCH_AUDITSYSCALL
1456471b825SIngo Molnar	select HAVE_ARCH_HUGE_VMAP		if X86_64 || X86_PAE
1466471b825SIngo Molnar	select HAVE_ARCH_JUMP_LABEL
147b34006c4SArd Biesheuvel	select HAVE_ARCH_JUMP_LABEL_RELATIVE
148d17a1d97SAndrey Ryabinin	select HAVE_ARCH_KASAN			if X86_64
1490609ae01SDaniel Axtens	select HAVE_ARCH_KASAN_VMALLOC		if X86_64
1506471b825SIngo Molnar	select HAVE_ARCH_KGDB
1519e08f57dSDaniel Cashman	select HAVE_ARCH_MMAP_RND_BITS		if MMU
1529e08f57dSDaniel Cashman	select HAVE_ARCH_MMAP_RND_COMPAT_BITS	if MMU && COMPAT
1531b028f78SDmitry Safonov	select HAVE_ARCH_COMPAT_MMAP_BASES	if MMU && COMPAT
154271ca788SArd Biesheuvel	select HAVE_ARCH_PREL32_RELOCATIONS
1556471b825SIngo Molnar	select HAVE_ARCH_SECCOMP_FILTER
156f7d83c1cSKees Cook	select HAVE_ARCH_THREAD_STRUCT_WHITELIST
157afaef01cSAlexander Popov	select HAVE_ARCH_STACKLEAK
1586471b825SIngo Molnar	select HAVE_ARCH_TRACEHOOK
1596471b825SIngo Molnar	select HAVE_ARCH_TRANSPARENT_HUGEPAGE
160a00cc7d9SMatthew Wilcox	select HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD if X86_64
161b64d8d1eSPeter Xu	select HAVE_ARCH_USERFAULTFD_WP         if X86_64 && USERFAULTFD
162e37e43a4SAndy Lutomirski	select HAVE_ARCH_VMAP_STACK		if X86_64
163c763ea26SIngo Molnar	select HAVE_ARCH_WITHIN_STACK_FRAMES
1642ff2b7ecSMasahiro Yamada	select HAVE_ASM_MODVERSIONS
1656471b825SIngo Molnar	select HAVE_CMPXCHG_DOUBLE
1666471b825SIngo Molnar	select HAVE_CMPXCHG_LOCAL
1676471b825SIngo Molnar	select HAVE_CONTEXT_TRACKING		if X86_64
168d1f250e2SFrederic Weisbecker	select HAVE_CONTEXT_TRACKING_OFFSTACK	if HAVE_CONTEXT_TRACKING
1696471b825SIngo Molnar	select HAVE_C_RECORDMCOUNT
1706471b825SIngo Molnar	select HAVE_DEBUG_KMEMLEAK
1719c5a3621SAkinobu Mita	select HAVE_DMA_CONTIGUOUS
172677aa9f7SSteven Rostedt	select HAVE_DYNAMIC_FTRACE
17306aeaaeaSMasami Hiramatsu	select HAVE_DYNAMIC_FTRACE_WITH_REGS
17402a474caSSteven Rostedt (VMware)	select HAVE_DYNAMIC_FTRACE_WITH_ARGS	if X86_64
175562955feSSteven Rostedt (VMware)	select HAVE_DYNAMIC_FTRACE_WITH_DIRECT_CALLS
17603f5781bSWang YanQing	select HAVE_EBPF_JIT
17758340a07SJohannes Berg	select HAVE_EFFICIENT_UNALIGNED_ACCESS
1786630a8e5SChristoph Hellwig	select HAVE_EISA
1795f56a5dfSJiri Slaby	select HAVE_EXIT_THREAD
18067a929e0SChristoph Hellwig	select HAVE_FAST_GUP
181644e0e8dSSteven Rostedt (VMware)	select HAVE_FENTRY			if X86_64 || DYNAMIC_FTRACE
1826471b825SIngo Molnar	select HAVE_FTRACE_MCOUNT_RECORD
1836471b825SIngo Molnar	select HAVE_FUNCTION_GRAPH_TRACER
1846471b825SIngo Molnar	select HAVE_FUNCTION_TRACER
1856b90bd4bSEmese Revfy	select HAVE_GCC_PLUGINS
1860067f129SK.Prasad	select HAVE_HW_BREAKPOINT
1876471b825SIngo Molnar	select HAVE_IDE
1886471b825SIngo Molnar	select HAVE_IOREMAP_PROT
1896471b825SIngo Molnar	select HAVE_IRQ_TIME_ACCOUNTING
1906471b825SIngo Molnar	select HAVE_KERNEL_BZIP2
1916471b825SIngo Molnar	select HAVE_KERNEL_GZIP
1926471b825SIngo Molnar	select HAVE_KERNEL_LZ4
1936471b825SIngo Molnar	select HAVE_KERNEL_LZMA
1946471b825SIngo Molnar	select HAVE_KERNEL_LZO
1956471b825SIngo Molnar	select HAVE_KERNEL_XZ
196fb46d057SNick Terrell	select HAVE_KERNEL_ZSTD
1976471b825SIngo Molnar	select HAVE_KPROBES
1986471b825SIngo Molnar	select HAVE_KPROBES_ON_FTRACE
199540adea3SMasami Hiramatsu	select HAVE_FUNCTION_ERROR_INJECTION
2006471b825SIngo Molnar	select HAVE_KRETPROBES
2016471b825SIngo Molnar	select HAVE_KVM
2026471b825SIngo Molnar	select HAVE_LIVEPATCH			if X86_64
2030102752eSFrederic Weisbecker	select HAVE_MIXED_BREAKPOINTS_REGS
204ee9f8fceSJosh Poimboeuf	select HAVE_MOD_ARCH_SPECIFIC
2059f132f7eSJoel Fernandes (Google)	select HAVE_MOVE_PMD
206be37c98dSKalesh Singh	select HAVE_MOVE_PUD
20742a0bb3fSPetr Mladek	select HAVE_NMI
2086471b825SIngo Molnar	select HAVE_OPROFILE
2096471b825SIngo Molnar	select HAVE_OPTPROBES
2106471b825SIngo Molnar	select HAVE_PCSPKR_PLATFORM
2116471b825SIngo Molnar	select HAVE_PERF_EVENTS
212c01d4323SFrederic Weisbecker	select HAVE_PERF_EVENTS_NMI
21392e5aae4SNicholas Piggin	select HAVE_HARDLOCKUP_DETECTOR_PERF	if PERF_EVENTS && HAVE_PERF_EVENTS_NMI
214eb01d42aSChristoph Hellwig	select HAVE_PCI
215c5e63197SJiri Olsa	select HAVE_PERF_REGS
216c5ebcedbSJiri Olsa	select HAVE_PERF_USER_STACK_DUMP
217ff2e6d72SPeter Zijlstra	select MMU_GATHER_RCU_TABLE_FREE		if PARAVIRT
21800998085SThomas Gleixner	select HAVE_POSIX_CPU_TIMERS_TASK_WORK
2196471b825SIngo Molnar	select HAVE_REGS_AND_STACK_ACCESS_API
2206415b38bSJiri Slaby	select HAVE_RELIABLE_STACKTRACE		if X86_64 && (UNWINDER_FRAME_POINTER || UNWINDER_ORC) && STACK_VALIDATION
2213c88ee19SMasami Hiramatsu	select HAVE_FUNCTION_ARG_ACCESS_API
222d148eac0SMasahiro Yamada	select HAVE_STACKPROTECTOR		if CC_HAS_SANE_STACKPROTECTOR
223c763ea26SIngo Molnar	select HAVE_STACK_VALIDATION		if X86_64
224e6d6c071SJosh Poimboeuf	select HAVE_STATIC_CALL
2251e7e4788SJosh Poimboeuf	select HAVE_STATIC_CALL_INLINE		if HAVE_STACK_VALIDATION
226d6761b8fSMathieu Desnoyers	select HAVE_RSEQ
2276471b825SIngo Molnar	select HAVE_SYSCALL_TRACEPOINTS
2286471b825SIngo Molnar	select HAVE_UNSTABLE_SCHED_CLOCK
2297c68af6eSAvi Kivity	select HAVE_USER_RETURN_NOTIFIER
2307ac87074SVincenzo Frascino	select HAVE_GENERIC_VDSO
23105736e4aSThomas Gleixner	select HOTPLUG_SMT			if SMP
232c0185808SThomas Gleixner	select IRQ_FORCED_THREADING
23386596f0aSChristoph Hellwig	select NEED_SG_DMA_LENGTH
2342eac9c2dSChristoph Hellwig	select PCI_DOMAINS			if PCI
235625210cfSSinan Kaya	select PCI_LOCKLESS_CONFIG		if PCI
2366471b825SIngo Molnar	select PERF_EVENTS
2373195ef59SPrarit Bhargava	select RTC_LIB
238d6faca40SArnd Bergmann	select RTC_MC146818_LIB
2396471b825SIngo Molnar	select SPARSE_IRQ
24083fe27eaSPranith Kumar	select SRCU
2411e7e4788SJosh Poimboeuf	select STACK_VALIDATION			if HAVE_STACK_VALIDATION && (HAVE_STATIC_CALL_INLINE || RETPOLINE)
2426471b825SIngo Molnar	select SYSCTL_EXCEPTION_TRACE
24315f4eae7SAndy Lutomirski	select THREAD_INFO_IN_TASK
2446471b825SIngo Molnar	select USER_STACKTRACE_SUPPORT
2456471b825SIngo Molnar	select VIRT_TO_BUS
2463b02a051SIngo Molnar	select HAVE_ARCH_KCSAN			if X86_64
2476471b825SIngo Molnar	select X86_FEATURE_NAMES		if PROC_FS
2480c608dadSAubrey Li	select PROC_PID_ARCH_STATUS		if PROC_FS
2499e2b4be3SNayna Jain	imply IMA_SECURE_AND_OR_TRUSTED_BOOT    if EFI
2507d8330a5SBalbir Singh
251ba7e4d13SIngo Molnarconfig INSTRUCTION_DECODER
2523120e25eSJan Beulich	def_bool y
2533120e25eSJan Beulich	depends on KPROBES || PERF_EVENTS || UPROBES
254ba7e4d13SIngo Molnar
25551b26adaSLinus Torvaldsconfig OUTPUT_FORMAT
25651b26adaSLinus Torvalds	string
25751b26adaSLinus Torvalds	default "elf32-i386" if X86_32
25851b26adaSLinus Torvalds	default "elf64-x86-64" if X86_64
25951b26adaSLinus Torvalds
2608d5fffb9SSam Ravnborgconfig LOCKDEP_SUPPORT
2613c2362e6SHarvey Harrison	def_bool y
2628d5fffb9SSam Ravnborg
2638d5fffb9SSam Ravnborgconfig STACKTRACE_SUPPORT
2643c2362e6SHarvey Harrison	def_bool y
2658d5fffb9SSam Ravnborg
2668d5fffb9SSam Ravnborgconfig MMU
2673c2362e6SHarvey Harrison	def_bool y
2688d5fffb9SSam Ravnborg
2699e08f57dSDaniel Cashmanconfig ARCH_MMAP_RND_BITS_MIN
2709e08f57dSDaniel Cashman	default 28 if 64BIT
2719e08f57dSDaniel Cashman	default 8
2729e08f57dSDaniel Cashman
2739e08f57dSDaniel Cashmanconfig ARCH_MMAP_RND_BITS_MAX
2749e08f57dSDaniel Cashman	default 32 if 64BIT
2759e08f57dSDaniel Cashman	default 16
2769e08f57dSDaniel Cashman
2779e08f57dSDaniel Cashmanconfig ARCH_MMAP_RND_COMPAT_BITS_MIN
2789e08f57dSDaniel Cashman	default 8
2799e08f57dSDaniel Cashman
2809e08f57dSDaniel Cashmanconfig ARCH_MMAP_RND_COMPAT_BITS_MAX
2819e08f57dSDaniel Cashman	default 16
2829e08f57dSDaniel Cashman
2838d5fffb9SSam Ravnborgconfig SBUS
2848d5fffb9SSam Ravnborg	bool
2858d5fffb9SSam Ravnborg
2868d5fffb9SSam Ravnborgconfig GENERIC_ISA_DMA
2873120e25eSJan Beulich	def_bool y
2883120e25eSJan Beulich	depends on ISA_DMA_API
2898d5fffb9SSam Ravnborg
2908d5fffb9SSam Ravnborgconfig GENERIC_BUG
2913c2362e6SHarvey Harrison	def_bool y
2928d5fffb9SSam Ravnborg	depends on BUG
293b93a531eSJan Beulich	select GENERIC_BUG_RELATIVE_POINTERS if X86_64
294b93a531eSJan Beulich
295b93a531eSJan Beulichconfig GENERIC_BUG_RELATIVE_POINTERS
296b93a531eSJan Beulich	bool
2978d5fffb9SSam Ravnborg
2988d5fffb9SSam Ravnborgconfig ARCH_MAY_HAVE_PC_FDC
2993120e25eSJan Beulich	def_bool y
3003120e25eSJan Beulich	depends on ISA_DMA_API
3018d5fffb9SSam Ravnborg
3021032c0baSSam Ravnborgconfig GENERIC_CALIBRATE_DELAY
3031032c0baSSam Ravnborg	def_bool y
3041032c0baSSam Ravnborg
3059a0b8415Svenkatesh.pallipadi@intel.comconfig ARCH_HAS_CPU_RELAX
3069a0b8415Svenkatesh.pallipadi@intel.com	def_bool y
3078d5fffb9SSam Ravnborg
3081b27d05bSPekka Enbergconfig ARCH_HAS_CACHE_LINE_SIZE
3091b27d05bSPekka Enberg	def_bool y
3101b27d05bSPekka Enberg
311316d097cSDave Hansenconfig ARCH_HAS_FILTER_PGPROT
312316d097cSDave Hansen	def_bool y
313316d097cSDave Hansen
314dd5af90aSMike Travisconfig HAVE_SETUP_PER_CPU_AREA
31589c9c4c5SBrian Gerst	def_bool y
316b32ef636Stravis@sgi.com
31708fc4580STejun Heoconfig NEED_PER_CPU_EMBED_FIRST_CHUNK
31808fc4580STejun Heo	def_bool y
31908fc4580STejun Heo
32008fc4580STejun Heoconfig NEED_PER_CPU_PAGE_FIRST_CHUNK
32111124411STejun Heo	def_bool y
32211124411STejun Heo
323801e4062SJohannes Bergconfig ARCH_HIBERNATION_POSSIBLE
324801e4062SJohannes Berg	def_bool y
325801e4062SJohannes Berg
326f4cb5700SJohannes Bergconfig ARCH_SUSPEND_POSSIBLE
327f4cb5700SJohannes Berg	def_bool y
328f4cb5700SJohannes Berg
32953313b2cSSteve Capperconfig ARCH_WANT_GENERAL_HUGETLB
33053313b2cSSteve Capper	def_bool y
33153313b2cSSteve Capper
3328d5fffb9SSam Ravnborgconfig ZONE_DMA32
333e0fd24a3SJan Beulich	def_bool y if X86_64
3348d5fffb9SSam Ravnborg
3358d5fffb9SSam Ravnborgconfig AUDIT_ARCH
336e0fd24a3SJan Beulich	def_bool y if X86_64
3378d5fffb9SSam Ravnborg
338d6f2d75aSAndrey Ryabininconfig KASAN_SHADOW_OFFSET
339d6f2d75aSAndrey Ryabinin	hex
340d6f2d75aSAndrey Ryabinin	depends on KASAN
341d6f2d75aSAndrey Ryabinin	default 0xdffffc0000000000
342d6f2d75aSAndrey Ryabinin
34369575d38SShane Wangconfig HAVE_INTEL_TXT
34469575d38SShane Wang	def_bool y
3456ea30386SKees Cook	depends on INTEL_IOMMU && ACPI
34669575d38SShane Wang
3476b0c3d44SSam Ravnborgconfig X86_32_SMP
3486b0c3d44SSam Ravnborg	def_bool y
3496b0c3d44SSam Ravnborg	depends on X86_32 && SMP
3506b0c3d44SSam Ravnborg
3516b0c3d44SSam Ravnborgconfig X86_64_SMP
3526b0c3d44SSam Ravnborg	def_bool y
3536b0c3d44SSam Ravnborg	depends on X86_64 && SMP
3546b0c3d44SSam Ravnborg
355ccbeed3aSTejun Heoconfig X86_32_LAZY_GS
356ccbeed3aSTejun Heo	def_bool y
3578458f8c2SMasahiro Yamada	depends on X86_32 && !STACKPROTECTOR
358ccbeed3aSTejun Heo
3592b144498SSrikar Dronamrajuconfig ARCH_SUPPORTS_UPROBES
3602b144498SSrikar Dronamraju	def_bool y
3612b144498SSrikar Dronamraju
362d20642f0SRob Herringconfig FIX_EARLYCON_MEM
363d20642f0SRob Herring	def_bool y
364d20642f0SRob Herring
36594d49eb3SKirill A. Shutemovconfig DYNAMIC_PHYSICAL_MASK
36694d49eb3SKirill A. Shutemov	bool
36794d49eb3SKirill A. Shutemov
36898233368SKirill A. Shutemovconfig PGTABLE_LEVELS
36998233368SKirill A. Shutemov	int
37077ef56e4SKirill A. Shutemov	default 5 if X86_5LEVEL
37198233368SKirill A. Shutemov	default 4 if X86_64
37298233368SKirill A. Shutemov	default 3 if X86_PAE
37398233368SKirill A. Shutemov	default 2
37498233368SKirill A. Shutemov
3752a61f474SMasahiro Yamadaconfig CC_HAS_SANE_STACKPROTECTOR
3762a61f474SMasahiro Yamada	bool
3772a61f474SMasahiro Yamada	default $(success,$(srctree)/scripts/gcc-x86_64-has-stack-protector.sh $(CC)) if 64BIT
3782a61f474SMasahiro Yamada	default $(success,$(srctree)/scripts/gcc-x86_32-has-stack-protector.sh $(CC))
3792a61f474SMasahiro Yamada	help
3802a61f474SMasahiro Yamada	   We have to make sure stack protector is unconditionally disabled if
3812a61f474SMasahiro Yamada	   the compiler produces broken code.
3822a61f474SMasahiro Yamada
383506f1d07SSam Ravnborgmenu "Processor type and features"
384506f1d07SSam Ravnborg
3855ee71535SRandy Dunlapconfig ZONE_DMA
3865ee71535SRandy Dunlap	bool "DMA memory allocation support" if EXPERT
3875ee71535SRandy Dunlap	default y
3885ee71535SRandy Dunlap	help
3895ee71535SRandy Dunlap	  DMA memory allocation support allows devices with less than 32-bit
3905ee71535SRandy Dunlap	  addressing to allocate within the first 16MB of address space.
3915ee71535SRandy Dunlap	  Disable if no such devices will be used.
3925ee71535SRandy Dunlap
3935ee71535SRandy Dunlap	  If unsure, say Y.
3945ee71535SRandy Dunlap
395506f1d07SSam Ravnborgconfig SMP
396506f1d07SSam Ravnborg	bool "Symmetric multi-processing support"
397a7f7f624SMasahiro Yamada	help
398506f1d07SSam Ravnborg	  This enables support for systems with more than one CPU. If you have
3994a474157SRobert Graffham	  a system with only one CPU, say N. If you have a system with more
4004a474157SRobert Graffham	  than one CPU, say Y.
401506f1d07SSam Ravnborg
4024a474157SRobert Graffham	  If you say N here, the kernel will run on uni- and multiprocessor
403506f1d07SSam Ravnborg	  machines, but will use only one CPU of a multiprocessor machine. If
404506f1d07SSam Ravnborg	  you say Y here, the kernel will run on many, but not all,
4054a474157SRobert Graffham	  uniprocessor machines. On a uniprocessor machine, the kernel
406506f1d07SSam Ravnborg	  will run faster if you say N here.
407506f1d07SSam Ravnborg
408506f1d07SSam Ravnborg	  Note that if you say Y here and choose architecture "586" or
409506f1d07SSam Ravnborg	  "Pentium" under "Processor family", the kernel will not work on 486
410506f1d07SSam Ravnborg	  architectures. Similarly, multiprocessor kernels for the "PPro"
411506f1d07SSam Ravnborg	  architecture may not work on all Pentium based boards.
412506f1d07SSam Ravnborg
413506f1d07SSam Ravnborg	  People using multiprocessor machines who say Y here should also say
414506f1d07SSam Ravnborg	  Y to "Enhanced Real Time Clock Support", below. The "Advanced Power
415506f1d07SSam Ravnborg	  Management" code will be disabled if you say Y here.
416506f1d07SSam Ravnborg
417cb1aaebeSMauro Carvalho Chehab	  See also <file:Documentation/x86/i386/IO-APIC.rst>,
4184f4cfa6cSMauro Carvalho Chehab	  <file:Documentation/admin-guide/lockup-watchdogs.rst> and the SMP-HOWTO available at
419506f1d07SSam Ravnborg	  <http://www.tldp.org/docs.html#howto>.
420506f1d07SSam Ravnborg
421506f1d07SSam Ravnborg	  If you don't know what to do here, say N.
422506f1d07SSam Ravnborg
4239def39beSJosh Triplettconfig X86_FEATURE_NAMES
4249def39beSJosh Triplett	bool "Processor feature human-readable names" if EMBEDDED
4259def39beSJosh Triplett	default y
426a7f7f624SMasahiro Yamada	help
4279def39beSJosh Triplett	  This option compiles in a table of x86 feature bits and corresponding
4289def39beSJosh Triplett	  names.  This is required to support /proc/cpuinfo and a few kernel
4299def39beSJosh Triplett	  messages.  You can disable this to save space, at the expense of
4309def39beSJosh Triplett	  making those few kernel messages show numeric feature bits instead.
4319def39beSJosh Triplett
4329def39beSJosh Triplett	  If in doubt, say Y.
4339def39beSJosh Triplett
43406cd9a7dSYinghai Luconfig X86_X2APIC
43506cd9a7dSYinghai Lu	bool "Support x2apic"
43619e3d60dSJan Kiszka	depends on X86_LOCAL_APIC && X86_64 && (IRQ_REMAP || HYPERVISOR_GUEST)
437a7f7f624SMasahiro Yamada	help
43806cd9a7dSYinghai Lu	  This enables x2apic support on CPUs that have this feature.
43906cd9a7dSYinghai Lu
44006cd9a7dSYinghai Lu	  This allows 32-bit apic IDs (so it can support very large systems),
44106cd9a7dSYinghai Lu	  and accesses the local apic via MSRs not via mmio.
44206cd9a7dSYinghai Lu
44306cd9a7dSYinghai Lu	  If you don't know what to do here, say N.
44406cd9a7dSYinghai Lu
4456695c85bSYinghai Luconfig X86_MPPARSE
4466e87f9b7SBin Gao	bool "Enable MPS table" if ACPI || SFI
4477a527688SJan Beulich	default y
4485ab74722SIngo Molnar	depends on X86_LOCAL_APIC
449a7f7f624SMasahiro Yamada	help
4506695c85bSYinghai Lu	  For old smp systems that do not have proper acpi support. Newer systems
4516695c85bSYinghai Lu	  (esp with 64bit cpus) with acpi support, MADT and DSDT will override it
4526695c85bSYinghai Lu
453ddd70cf9SJun Nakajimaconfig GOLDFISH
454ddd70cf9SJun Nakajima	def_bool y
455ddd70cf9SJun Nakajima	depends on X86_GOLDFISH
456ddd70cf9SJun Nakajima
45776b04384SDavid Woodhouseconfig RETPOLINE
45876b04384SDavid Woodhouse	bool "Avoid speculative indirect branches in kernel"
45976b04384SDavid Woodhouse	default y
46076b04384SDavid Woodhouse	help
46176b04384SDavid Woodhouse	  Compile kernel with the retpoline compiler options to guard against
46276b04384SDavid Woodhouse	  kernel-to-user data leaks by avoiding speculative indirect
46376b04384SDavid Woodhouse	  branches. Requires a compiler with -mindirect-branch=thunk-extern
46476b04384SDavid Woodhouse	  support for full protection. The kernel may run slower.
46576b04384SDavid Woodhouse
466e6d42931SJohannes Weinerconfig X86_CPU_RESCTRL
467e6d42931SJohannes Weiner	bool "x86 CPU resource control support"
4686fe07ce3SBabu Moger	depends on X86 && (CPU_SUP_INTEL || CPU_SUP_AMD)
46959fe5a77SThomas Gleixner	select KERNFS
470e79f15a4SChen Yu	select PROC_CPU_RESCTRL		if PROC_FS
47178e99b4aSFenghua Yu	help
472e6d42931SJohannes Weiner	  Enable x86 CPU resource control support.
4736fe07ce3SBabu Moger
4746fe07ce3SBabu Moger	  Provide support for the allocation and monitoring of system resources
4756fe07ce3SBabu Moger	  usage by the CPU.
4766fe07ce3SBabu Moger
4776fe07ce3SBabu Moger	  Intel calls this Intel Resource Director Technology
4786fe07ce3SBabu Moger	  (Intel(R) RDT). More information about RDT can be found in the
4796fe07ce3SBabu Moger	  Intel x86 Architecture Software Developer Manual.
4806fe07ce3SBabu Moger
4816fe07ce3SBabu Moger	  AMD calls this AMD Platform Quality of Service (AMD QoS).
4826fe07ce3SBabu Moger	  More information about AMD QoS can be found in the AMD64 Technology
4836fe07ce3SBabu Moger	  Platform Quality of Service Extensions manual.
48478e99b4aSFenghua Yu
48578e99b4aSFenghua Yu	  Say N if unsure.
48678e99b4aSFenghua Yu
4878425091fSRavikiran G Thirumalaiif X86_32
488a0d0bb4dSRandy Dunlapconfig X86_BIGSMP
489a0d0bb4dSRandy Dunlap	bool "Support for big SMP systems with more than 8 CPUs"
490a0d0bb4dSRandy Dunlap	depends on SMP
491a7f7f624SMasahiro Yamada	help
492e133f6eaSRandy Dunlap	  This option is needed for the systems that have more than 8 CPUs.
493a0d0bb4dSRandy Dunlap
494c5c606d9SRavikiran G Thirumalaiconfig X86_EXTENDED_PLATFORM
495c5c606d9SRavikiran G Thirumalai	bool "Support for extended (non-PC) x86 platforms"
496c5c606d9SRavikiran G Thirumalai	default y
497a7f7f624SMasahiro Yamada	help
49806ac8346SIngo Molnar	  If you disable this option then the kernel will only support
49906ac8346SIngo Molnar	  standard PC platforms. (which covers the vast majority of
50006ac8346SIngo Molnar	  systems out there.)
50106ac8346SIngo Molnar
5028425091fSRavikiran G Thirumalai	  If you enable this option then you'll be able to select support
5038425091fSRavikiran G Thirumalai	  for the following (non-PC) 32 bit x86 platforms:
504cb7b8023SBen Hutchings		Goldfish (Android emulator)
5058425091fSRavikiran G Thirumalai		AMD Elan
5068425091fSRavikiran G Thirumalai		RDC R-321x SoC
5078425091fSRavikiran G Thirumalai		SGI 320/540 (Visual Workstation)
50883125a3aSAlessandro Rubini		STA2X11-based (e.g. Northville)
5093f4110a4SThomas Gleixner		Moorestown MID devices
51006ac8346SIngo Molnar
51106ac8346SIngo Molnar	  If you have one of these systems, or if you want to build a
51206ac8346SIngo Molnar	  generic distribution kernel, say Y here - otherwise say N.
5138425091fSRavikiran G Thirumalaiendif
51406ac8346SIngo Molnar
5158425091fSRavikiran G Thirumalaiif X86_64
5168425091fSRavikiran G Thirumalaiconfig X86_EXTENDED_PLATFORM
5178425091fSRavikiran G Thirumalai	bool "Support for extended (non-PC) x86 platforms"
5188425091fSRavikiran G Thirumalai	default y
519a7f7f624SMasahiro Yamada	help
5208425091fSRavikiran G Thirumalai	  If you disable this option then the kernel will only support
5218425091fSRavikiran G Thirumalai	  standard PC platforms. (which covers the vast majority of
5228425091fSRavikiran G Thirumalai	  systems out there.)
5238425091fSRavikiran G Thirumalai
5248425091fSRavikiran G Thirumalai	  If you enable this option then you'll be able to select support
5258425091fSRavikiran G Thirumalai	  for the following (non-PC) 64 bit x86 platforms:
52644b111b5SSteffen Persvold		Numascale NumaChip
5278425091fSRavikiran G Thirumalai		ScaleMP vSMP
5288425091fSRavikiran G Thirumalai		SGI Ultraviolet
5298425091fSRavikiran G Thirumalai
5308425091fSRavikiran G Thirumalai	  If you have one of these systems, or if you want to build a
5318425091fSRavikiran G Thirumalai	  generic distribution kernel, say Y here - otherwise say N.
5328425091fSRavikiran G Thirumalaiendif
533c5c606d9SRavikiran G Thirumalai# This is an alphabetically sorted list of 64 bit extended platforms
534c5c606d9SRavikiran G Thirumalai# Please maintain the alphabetic order if and when there are additions
53544b111b5SSteffen Persvoldconfig X86_NUMACHIP
53644b111b5SSteffen Persvold	bool "Numascale NumaChip"
53744b111b5SSteffen Persvold	depends on X86_64
53844b111b5SSteffen Persvold	depends on X86_EXTENDED_PLATFORM
53944b111b5SSteffen Persvold	depends on NUMA
54044b111b5SSteffen Persvold	depends on SMP
54144b111b5SSteffen Persvold	depends on X86_X2APIC
542f9726bfdSDaniel J Blueman	depends on PCI_MMCONFIG
543a7f7f624SMasahiro Yamada	help
54444b111b5SSteffen Persvold	  Adds support for Numascale NumaChip large-SMP systems. Needed to
54544b111b5SSteffen Persvold	  enable more than ~168 cores.
54644b111b5SSteffen Persvold	  If you don't have one of these, you should say N here.
54703b48632SNick Piggin
5486a48565eSIngo Molnarconfig X86_VSMP
549c5c606d9SRavikiran G Thirumalai	bool "ScaleMP vSMP"
5506276a074SBorislav Petkov	select HYPERVISOR_GUEST
5516a48565eSIngo Molnar	select PARAVIRT
5526a48565eSIngo Molnar	depends on X86_64 && PCI
553c5c606d9SRavikiran G Thirumalai	depends on X86_EXTENDED_PLATFORM
554ead91d4bSShai Fultheim	depends on SMP
555a7f7f624SMasahiro Yamada	help
5566a48565eSIngo Molnar	  Support for ScaleMP vSMP systems.  Say 'Y' here if this kernel is
5576a48565eSIngo Molnar	  supposed to run on these EM64T-based machines.  Only choose this option
5586a48565eSIngo Molnar	  if you have one of these machines.
5596a48565eSIngo Molnar
560c5c606d9SRavikiran G Thirumalaiconfig X86_UV
561c5c606d9SRavikiran G Thirumalai	bool "SGI Ultraviolet"
562c5c606d9SRavikiran G Thirumalai	depends on X86_64
563c5c606d9SRavikiran G Thirumalai	depends on X86_EXTENDED_PLATFORM
56454c28d29SJack Steiner	depends on NUMA
5651ecb4ae5SAndrew Morton	depends on EFI
5669d6c26e7SSuresh Siddha	depends on X86_X2APIC
5671222e564SIngo Molnar	depends on PCI
568a7f7f624SMasahiro Yamada	help
569c5c606d9SRavikiran G Thirumalai	  This option is needed in order to support SGI Ultraviolet systems.
570c5c606d9SRavikiran G Thirumalai	  If you don't have one of these, you should say N here.
571c5c606d9SRavikiran G Thirumalai
572c5c606d9SRavikiran G Thirumalai# Following is an alphabetically sorted list of 32 bit extended platforms
573c5c606d9SRavikiran G Thirumalai# Please maintain the alphabetic order if and when there are additions
574506f1d07SSam Ravnborg
575ddd70cf9SJun Nakajimaconfig X86_GOLDFISH
576ddd70cf9SJun Nakajima	bool "Goldfish (Virtual Platform)"
577cb7b8023SBen Hutchings	depends on X86_EXTENDED_PLATFORM
578a7f7f624SMasahiro Yamada	help
579ddd70cf9SJun Nakajima	 Enable support for the Goldfish virtual platform used primarily
580ddd70cf9SJun Nakajima	 for Android development. Unless you are building for the Android
581ddd70cf9SJun Nakajima	 Goldfish emulator say N here.
582ddd70cf9SJun Nakajima
583c751e17bSThomas Gleixnerconfig X86_INTEL_CE
584c751e17bSThomas Gleixner	bool "CE4100 TV platform"
585c751e17bSThomas Gleixner	depends on PCI
586c751e17bSThomas Gleixner	depends on PCI_GODIRECT
5876084a6e2SJiang Liu	depends on X86_IO_APIC
588c751e17bSThomas Gleixner	depends on X86_32
589c751e17bSThomas Gleixner	depends on X86_EXTENDED_PLATFORM
59037bc9f50SDirk Brandewie	select X86_REBOOTFIXUPS
591da6b737bSSebastian Andrzej Siewior	select OF
592da6b737bSSebastian Andrzej Siewior	select OF_EARLY_FLATTREE
593a7f7f624SMasahiro Yamada	help
594c751e17bSThomas Gleixner	  Select for the Intel CE media processor (CE4100) SOC.
595c751e17bSThomas Gleixner	  This option compiles in support for the CE4100 SOC for settop
596c751e17bSThomas Gleixner	  boxes and media devices.
597c751e17bSThomas Gleixner
5984cb9b00fSDavid Cohenconfig X86_INTEL_MID
59943605ef1SAlan Cox	bool "Intel MID platform support"
60043605ef1SAlan Cox	depends on X86_EXTENDED_PLATFORM
601edc6bc78SDavid Cohen	depends on X86_PLATFORM_DEVICES
6021ea7c673SAlan Cox	depends on PCI
6033fda5bb4SAndy Shevchenko	depends on X86_64 || (PCI_GOANY && X86_32)
6041ea7c673SAlan Cox	depends on X86_IO_APIC
6057c9c3a1eSAlan Cox	select SFI
6064cb9b00fSDavid Cohen	select I2C
6077c9c3a1eSAlan Cox	select DW_APB_TIMER
6081ea7c673SAlan Cox	select APB_TIMER
60954b34aa0SMika Westerberg	select INTEL_SCU_PCI
61015a713dfSMika Westerberg	select MFD_INTEL_MSIC
611a7f7f624SMasahiro Yamada	help
6124cb9b00fSDavid Cohen	  Select to build a kernel capable of supporting Intel MID (Mobile
6134cb9b00fSDavid Cohen	  Internet Device) platform systems which do not have the PCI legacy
6144cb9b00fSDavid Cohen	  interfaces. If you are building for a PC class system say N here.
6151ea7c673SAlan Cox
6164cb9b00fSDavid Cohen	  Intel MID platforms are based on an Intel processor and chipset which
6174cb9b00fSDavid Cohen	  consume less power than most of the x86 derivatives.
61843605ef1SAlan Cox
6198bbc2a13SBryan O'Donoghueconfig X86_INTEL_QUARK
6208bbc2a13SBryan O'Donoghue	bool "Intel Quark platform support"
6218bbc2a13SBryan O'Donoghue	depends on X86_32
6228bbc2a13SBryan O'Donoghue	depends on X86_EXTENDED_PLATFORM
6238bbc2a13SBryan O'Donoghue	depends on X86_PLATFORM_DEVICES
6248bbc2a13SBryan O'Donoghue	depends on X86_TSC
6258bbc2a13SBryan O'Donoghue	depends on PCI
6268bbc2a13SBryan O'Donoghue	depends on PCI_GOANY
6278bbc2a13SBryan O'Donoghue	depends on X86_IO_APIC
6288bbc2a13SBryan O'Donoghue	select IOSF_MBI
6298bbc2a13SBryan O'Donoghue	select INTEL_IMR
6309ab6eb51SAndy Shevchenko	select COMMON_CLK
631a7f7f624SMasahiro Yamada	help
6328bbc2a13SBryan O'Donoghue	  Select to include support for Quark X1000 SoC.
6338bbc2a13SBryan O'Donoghue	  Say Y here if you have a Quark based system such as the Arduino
6348bbc2a13SBryan O'Donoghue	  compatible Intel Galileo.
6358bbc2a13SBryan O'Donoghue
6363d48aab1SMika Westerbergconfig X86_INTEL_LPSS
6373d48aab1SMika Westerberg	bool "Intel Low Power Subsystem Support"
6385962dd22SSinan Kaya	depends on X86 && ACPI && PCI
6393d48aab1SMika Westerberg	select COMMON_CLK
6400f531431SMathias Nyman	select PINCTRL
641eebb3e8dSAndy Shevchenko	select IOSF_MBI
642a7f7f624SMasahiro Yamada	help
6433d48aab1SMika Westerberg	  Select to build support for Intel Low Power Subsystem such as
6443d48aab1SMika Westerberg	  found on Intel Lynxpoint PCH. Selecting this option enables
6450f531431SMathias Nyman	  things like clock tree (common clock framework) and pincontrol
6460f531431SMathias Nyman	  which are needed by the LPSS peripheral drivers.
6473d48aab1SMika Westerberg
64892082a88SKen Xueconfig X86_AMD_PLATFORM_DEVICE
64992082a88SKen Xue	bool "AMD ACPI2Platform devices support"
65092082a88SKen Xue	depends on ACPI
65192082a88SKen Xue	select COMMON_CLK
65292082a88SKen Xue	select PINCTRL
653a7f7f624SMasahiro Yamada	help
65492082a88SKen Xue	  Select to interpret AMD specific ACPI device to platform device
65592082a88SKen Xue	  such as I2C, UART, GPIO found on AMD Carrizo and later chipsets.
65692082a88SKen Xue	  I2C and UART depend on COMMON_CLK to set clock. GPIO driver is
65792082a88SKen Xue	  implemented under PINCTRL subsystem.
65892082a88SKen Xue
659ced3ce76SDavid E. Boxconfig IOSF_MBI
660ced3ce76SDavid E. Box	tristate "Intel SoC IOSF Sideband support for SoC platforms"
661ced3ce76SDavid E. Box	depends on PCI
662a7f7f624SMasahiro Yamada	help
663ced3ce76SDavid E. Box	  This option enables sideband register access support for Intel SoC
664ced3ce76SDavid E. Box	  platforms. On these platforms the IOSF sideband is used in lieu of
665ced3ce76SDavid E. Box	  MSR's for some register accesses, mostly but not limited to thermal
666ced3ce76SDavid E. Box	  and power. Drivers may query the availability of this device to
667ced3ce76SDavid E. Box	  determine if they need the sideband in order to work on these
668ced3ce76SDavid E. Box	  platforms. The sideband is available on the following SoC products.
669ced3ce76SDavid E. Box	  This list is not meant to be exclusive.
670ced3ce76SDavid E. Box	   - BayTrail
671ced3ce76SDavid E. Box	   - Braswell
672ced3ce76SDavid E. Box	   - Quark
673ced3ce76SDavid E. Box
674ced3ce76SDavid E. Box	  You should say Y if you are running a kernel on one of these SoC's.
675ced3ce76SDavid E. Box
676ed2226bdSDavid E. Boxconfig IOSF_MBI_DEBUG
677ed2226bdSDavid E. Box	bool "Enable IOSF sideband access through debugfs"
678ed2226bdSDavid E. Box	depends on IOSF_MBI && DEBUG_FS
679a7f7f624SMasahiro Yamada	help
680ed2226bdSDavid E. Box	  Select this option to expose the IOSF sideband access registers (MCR,
681ed2226bdSDavid E. Box	  MDR, MCRX) through debugfs to write and read register information from
682ed2226bdSDavid E. Box	  different units on the SoC. This is most useful for obtaining device
683ed2226bdSDavid E. Box	  state information for debug and analysis. As this is a general access
684ed2226bdSDavid E. Box	  mechanism, users of this option would have specific knowledge of the
685ed2226bdSDavid E. Box	  device they want to access.
686ed2226bdSDavid E. Box
687ed2226bdSDavid E. Box	  If you don't require the option or are in doubt, say N.
688ed2226bdSDavid E. Box
689c5c606d9SRavikiran G Thirumalaiconfig X86_RDC321X
690c5c606d9SRavikiran G Thirumalai	bool "RDC R-321x SoC"
691506f1d07SSam Ravnborg	depends on X86_32
692c5c606d9SRavikiran G Thirumalai	depends on X86_EXTENDED_PLATFORM
693c5c606d9SRavikiran G Thirumalai	select M486
694c5c606d9SRavikiran G Thirumalai	select X86_REBOOTFIXUPS
695a7f7f624SMasahiro Yamada	help
696c5c606d9SRavikiran G Thirumalai	  This option is needed for RDC R-321x system-on-chip, also known
697c5c606d9SRavikiran G Thirumalai	  as R-8610-(G).
698c5c606d9SRavikiran G Thirumalai	  If you don't have one of these chips, you should say N here.
699c5c606d9SRavikiran G Thirumalai
700e0c7ae37SIngo Molnarconfig X86_32_NON_STANDARD
7019c398017SIngo Molnar	bool "Support non-standard 32-bit SMP architectures"
7029c398017SIngo Molnar	depends on X86_32 && SMP
703c5c606d9SRavikiran G Thirumalai	depends on X86_EXTENDED_PLATFORM
704a7f7f624SMasahiro Yamada	help
705b5660ba7SH. Peter Anvin	  This option compiles in the bigsmp and STA2X11 default
706b5660ba7SH. Peter Anvin	  subarchitectures.  It is intended for a generic binary
707b5660ba7SH. Peter Anvin	  kernel. If you select them all, kernel will probe it one by
708b5660ba7SH. Peter Anvin	  one and will fallback to default.
709d49c4288SYinghai Lu
710c5c606d9SRavikiran G Thirumalai# Alphabetically sorted list of Non standard 32 bit platforms
711d49c4288SYinghai Lu
712d949f36fSLinus Torvaldsconfig X86_SUPPORTS_MEMORY_FAILURE
7136fc108a0SJan Beulich	def_bool y
714d949f36fSLinus Torvalds	# MCE code calls memory_failure():
715d949f36fSLinus Torvalds	depends on X86_MCE
716d949f36fSLinus Torvalds	# On 32-bit this adds too big of NODES_SHIFT and we run out of page flags:
717d949f36fSLinus Torvalds	# On 32-bit SPARSEMEM adds too big of SECTIONS_WIDTH:
718d949f36fSLinus Torvalds	depends on X86_64 || !SPARSEMEM
719d949f36fSLinus Torvalds	select ARCH_SUPPORTS_MEMORY_FAILURE
720d949f36fSLinus Torvalds
72183125a3aSAlessandro Rubiniconfig STA2X11
72283125a3aSAlessandro Rubini	bool "STA2X11 Companion Chip Support"
72383125a3aSAlessandro Rubini	depends on X86_32_NON_STANDARD && PCI
72483125a3aSAlessandro Rubini	select SWIOTLB
72583125a3aSAlessandro Rubini	select MFD_STA2X11
7260145071bSLinus Walleij	select GPIOLIB
727a7f7f624SMasahiro Yamada	help
72883125a3aSAlessandro Rubini	  This adds support for boards based on the STA2X11 IO-Hub,
72983125a3aSAlessandro Rubini	  a.k.a. "ConneXt". The chip is used in place of the standard
73083125a3aSAlessandro Rubini	  PC chipset, so all "standard" peripherals are missing. If this
73183125a3aSAlessandro Rubini	  option is selected the kernel will still be able to boot on
73283125a3aSAlessandro Rubini	  standard PC machines.
73383125a3aSAlessandro Rubini
73482148d1dSShérabconfig X86_32_IRIS
73582148d1dSShérab	tristate "Eurobraille/Iris poweroff module"
73682148d1dSShérab	depends on X86_32
737a7f7f624SMasahiro Yamada	help
73882148d1dSShérab	  The Iris machines from EuroBraille do not have APM or ACPI support
73982148d1dSShérab	  to shut themselves down properly.  A special I/O sequence is
74082148d1dSShérab	  needed to do so, which is what this module does at
74182148d1dSShérab	  kernel shutdown.
74282148d1dSShérab
74382148d1dSShérab	  This is only for Iris machines from EuroBraille.
74482148d1dSShérab
74582148d1dSShérab	  If unused, say N.
74682148d1dSShérab
747ae1e9130SIngo Molnarconfig SCHED_OMIT_FRAME_POINTER
7483c2362e6SHarvey Harrison	def_bool y
7493c2362e6SHarvey Harrison	prompt "Single-depth WCHAN output"
750a87d0914SKen Chen	depends on X86
751a7f7f624SMasahiro Yamada	help
752506f1d07SSam Ravnborg	  Calculate simpler /proc/<PID>/wchan values. If this option
753506f1d07SSam Ravnborg	  is disabled then wchan values will recurse back to the
754506f1d07SSam Ravnborg	  caller function. This provides more accurate wchan values,
755506f1d07SSam Ravnborg	  at the expense of slightly more scheduling overhead.
756506f1d07SSam Ravnborg
757506f1d07SSam Ravnborg	  If in doubt, say "Y".
758506f1d07SSam Ravnborg
7596276a074SBorislav Petkovmenuconfig HYPERVISOR_GUEST
7606276a074SBorislav Petkov	bool "Linux guest support"
761a7f7f624SMasahiro Yamada	help
7626276a074SBorislav Petkov	  Say Y here to enable options for running Linux under various hyper-
7636276a074SBorislav Petkov	  visors. This option enables basic hypervisor detection and platform
7646276a074SBorislav Petkov	  setup.
765506f1d07SSam Ravnborg
7666276a074SBorislav Petkov	  If you say N, all options in this submenu will be skipped and
7676276a074SBorislav Petkov	  disabled, and Linux guest support won't be built in.
768506f1d07SSam Ravnborg
7696276a074SBorislav Petkovif HYPERVISOR_GUEST
770506f1d07SSam Ravnborg
771e61bd94aSEduardo Pereira Habkostconfig PARAVIRT
772e61bd94aSEduardo Pereira Habkost	bool "Enable paravirtualization code"
773a7f7f624SMasahiro Yamada	help
774e61bd94aSEduardo Pereira Habkost	  This changes the kernel so it can modify itself when it is run
775e61bd94aSEduardo Pereira Habkost	  under a hypervisor, potentially improving performance significantly
776e61bd94aSEduardo Pereira Habkost	  over full virtualization.  However, when run without a hypervisor
777e61bd94aSEduardo Pereira Habkost	  the kernel is theoretically slower and slightly larger.
778e61bd94aSEduardo Pereira Habkost
779c00a280aSJuergen Grossconfig PARAVIRT_XXL
780c00a280aSJuergen Gross	bool
781c00a280aSJuergen Gross
7826276a074SBorislav Petkovconfig PARAVIRT_DEBUG
7836276a074SBorislav Petkov	bool "paravirt-ops debugging"
7846276a074SBorislav Petkov	depends on PARAVIRT && DEBUG_KERNEL
785a7f7f624SMasahiro Yamada	help
7866276a074SBorislav Petkov	  Enable to debug paravirt_ops internals.  Specifically, BUG if
7876276a074SBorislav Petkov	  a paravirt_op is missing when it is called.
7886276a074SBorislav Petkov
789b4ecc126SJeremy Fitzhardingeconfig PARAVIRT_SPINLOCKS
790b4ecc126SJeremy Fitzhardinge	bool "Paravirtualization layer for spinlocks"
7916ea30386SKees Cook	depends on PARAVIRT && SMP
792a7f7f624SMasahiro Yamada	help
793b4ecc126SJeremy Fitzhardinge	  Paravirtualized spinlocks allow a pvops backend to replace the
794b4ecc126SJeremy Fitzhardinge	  spinlock implementation with something virtualization-friendly
795b4ecc126SJeremy Fitzhardinge	  (for example, block the virtual CPU rather than spinning).
796b4ecc126SJeremy Fitzhardinge
7974c4e4f61SRaghavendra K T	  It has a minimal impact on native kernels and gives a nice performance
7984c4e4f61SRaghavendra K T	  benefit on paravirtualized KVM / Xen kernels.
799b4ecc126SJeremy Fitzhardinge
8004c4e4f61SRaghavendra K T	  If you are unsure how to answer this question, answer Y.
801b4ecc126SJeremy Fitzhardinge
802ecca2502SZhao Yakuiconfig X86_HV_CALLBACK_VECTOR
803ecca2502SZhao Yakui	def_bool n
804ecca2502SZhao Yakui
8056276a074SBorislav Petkovsource "arch/x86/xen/Kconfig"
8066276a074SBorislav Petkov
8076276a074SBorislav Petkovconfig KVM_GUEST
8086276a074SBorislav Petkov	bool "KVM Guest support (including kvmclock)"
8096276a074SBorislav Petkov	depends on PARAVIRT
8106276a074SBorislav Petkov	select PARAVIRT_CLOCK
811a1c4423bSMarcelo Tosatti	select ARCH_CPUIDLE_HALTPOLL
812b1d40575SVitaly Kuznetsov	select X86_HV_CALLBACK_VECTOR
8136276a074SBorislav Petkov	default y
814a7f7f624SMasahiro Yamada	help
8156276a074SBorislav Petkov	  This option enables various optimizations for running under the KVM
8166276a074SBorislav Petkov	  hypervisor. It includes a paravirtualized clock, so that instead
8176276a074SBorislav Petkov	  of relying on a PIT (or probably other) emulation by the
8186276a074SBorislav Petkov	  underlying device model, the host provides the guest with
8196276a074SBorislav Petkov	  timing infrastructure such as time of day, and system time
8206276a074SBorislav Petkov
821a1c4423bSMarcelo Tosatticonfig ARCH_CPUIDLE_HALTPOLL
822a1c4423bSMarcelo Tosatti	def_bool n
823a1c4423bSMarcelo Tosatti	prompt "Disable host haltpoll when loading haltpoll driver"
824a1c4423bSMarcelo Tosatti	help
825a1c4423bSMarcelo Tosatti	  If virtualized under KVM, disable host haltpoll.
826a1c4423bSMarcelo Tosatti
8277733607fSMaran Wilsonconfig PVH
8287733607fSMaran Wilson	bool "Support for running PVH guests"
829a7f7f624SMasahiro Yamada	help
8307733607fSMaran Wilson	  This option enables the PVH entry point for guest virtual machines
8317733607fSMaran Wilson	  as specified in the x86/HVM direct boot ABI.
8327733607fSMaran Wilson
8336276a074SBorislav Petkovconfig PARAVIRT_TIME_ACCOUNTING
8346276a074SBorislav Petkov	bool "Paravirtual steal time accounting"
8356276a074SBorislav Petkov	depends on PARAVIRT
836a7f7f624SMasahiro Yamada	help
8376276a074SBorislav Petkov	  Select this option to enable fine granularity task steal time
8386276a074SBorislav Petkov	  accounting. Time spent executing other tasks in parallel with
8396276a074SBorislav Petkov	  the current vCPU is discounted from the vCPU power. To account for
8406276a074SBorislav Petkov	  that, there can be a small performance impact.
8416276a074SBorislav Petkov
8426276a074SBorislav Petkov	  If in doubt, say N here.
8436276a074SBorislav Petkov
8447af192c9SGerd Hoffmannconfig PARAVIRT_CLOCK
8457af192c9SGerd Hoffmann	bool
8467af192c9SGerd Hoffmann
8474a362601SJan Kiszkaconfig JAILHOUSE_GUEST
8484a362601SJan Kiszka	bool "Jailhouse non-root cell support"
849abde587bSArnd Bergmann	depends on X86_64 && PCI
85087e65d05SJan Kiszka	select X86_PM_TIMER
851a7f7f624SMasahiro Yamada	help
8524a362601SJan Kiszka	  This option allows to run Linux as guest in a Jailhouse non-root
8534a362601SJan Kiszka	  cell. You can leave this option disabled if you only want to start
8544a362601SJan Kiszka	  Jailhouse and run Linux afterwards in the root cell.
8554a362601SJan Kiszka
856ec7972c9SZhao Yakuiconfig ACRN_GUEST
857ec7972c9SZhao Yakui	bool "ACRN Guest support"
858ec7972c9SZhao Yakui	depends on X86_64
859498ad393SZhao Yakui	select X86_HV_CALLBACK_VECTOR
860ec7972c9SZhao Yakui	help
861ec7972c9SZhao Yakui	  This option allows to run Linux as guest in the ACRN hypervisor. ACRN is
862ec7972c9SZhao Yakui	  a flexible, lightweight reference open-source hypervisor, built with
863ec7972c9SZhao Yakui	  real-time and safety-criticality in mind. It is built for embedded
864ec7972c9SZhao Yakui	  IOT with small footprint and real-time features. More details can be
865ec7972c9SZhao Yakui	  found in https://projectacrn.org/.
866ec7972c9SZhao Yakui
8676276a074SBorislav Petkovendif #HYPERVISOR_GUEST
86897349135SJeremy Fitzhardinge
869506f1d07SSam Ravnborgsource "arch/x86/Kconfig.cpu"
870506f1d07SSam Ravnborg
871506f1d07SSam Ravnborgconfig HPET_TIMER
8723c2362e6SHarvey Harrison	def_bool X86_64
873506f1d07SSam Ravnborg	prompt "HPET Timer Support" if X86_32
874a7f7f624SMasahiro Yamada	help
875506f1d07SSam Ravnborg	  Use the IA-PC HPET (High Precision Event Timer) to manage
876506f1d07SSam Ravnborg	  time in preference to the PIT and RTC, if a HPET is
877506f1d07SSam Ravnborg	  present.
878506f1d07SSam Ravnborg	  HPET is the next generation timer replacing legacy 8254s.
879506f1d07SSam Ravnborg	  The HPET provides a stable time base on SMP
880506f1d07SSam Ravnborg	  systems, unlike the TSC, but it is more expensive to access,
8814e7f9df2SMichael S. Tsirkin	  as it is off-chip.  The interface used is documented
8824e7f9df2SMichael S. Tsirkin	  in the HPET spec, revision 1.
883506f1d07SSam Ravnborg
884506f1d07SSam Ravnborg	  You can safely choose Y here.  However, HPET will only be
885506f1d07SSam Ravnborg	  activated if the platform and the BIOS support this feature.
886506f1d07SSam Ravnborg	  Otherwise the 8254 will be used for timing services.
887506f1d07SSam Ravnborg
888506f1d07SSam Ravnborg	  Choose N to continue using the legacy 8254 timer.
889506f1d07SSam Ravnborg
890506f1d07SSam Ravnborgconfig HPET_EMULATE_RTC
8913c2362e6SHarvey Harrison	def_bool y
892*3228e1dcSAnand K Mistry	depends on HPET_TIMER && (RTC_DRV_CMOS=m || RTC_DRV_CMOS=y)
893506f1d07SSam Ravnborg
894bb24c471SJacob Panconfig APB_TIMER
895933b9463SAlan Cox	def_bool y if X86_INTEL_MID
896933b9463SAlan Cox	prompt "Intel MID APB Timer Support" if X86_INTEL_MID
89706c3df49SJamie Iles	select DW_APB_TIMER
898a0c3832aSAlan Cox	depends on X86_INTEL_MID && SFI
899bb24c471SJacob Pan	help
900bb24c471SJacob Pan	 APB timer is the replacement for 8254, HPET on X86 MID platforms.
901bb24c471SJacob Pan	 The APBT provides a stable time base on SMP
902bb24c471SJacob Pan	 systems, unlike the TSC, but it is more expensive to access,
903bb24c471SJacob Pan	 as it is off-chip. APB timers are always running regardless of CPU
904bb24c471SJacob Pan	 C states, they are used as per CPU clockevent device when possible.
905bb24c471SJacob Pan
9066a108a14SDavid Rientjes# Mark as expert because too many people got it wrong.
907506f1d07SSam Ravnborg# The code disables itself when not needed.
9087ae9392cSThomas Petazzoniconfig DMI
9097ae9392cSThomas Petazzoni	default y
910cf074402SArd Biesheuvel	select DMI_SCAN_MACHINE_NON_EFI_FALLBACK
9116a108a14SDavid Rientjes	bool "Enable DMI scanning" if EXPERT
912a7f7f624SMasahiro Yamada	help
9137ae9392cSThomas Petazzoni	  Enabled scanning of DMI to identify machine quirks. Say Y
9147ae9392cSThomas Petazzoni	  here unless you have verified that your setup is not
9157ae9392cSThomas Petazzoni	  affected by entries in the DMI blacklist. Required by PNP
9167ae9392cSThomas Petazzoni	  BIOS code.
9177ae9392cSThomas Petazzoni
918506f1d07SSam Ravnborgconfig GART_IOMMU
91938901f1cSAndi Kleen	bool "Old AMD GART IOMMU support"
9202f9237d4SChristoph Hellwig	select DMA_OPS
921a4ce5a48SChristoph Hellwig	select IOMMU_HELPER
922506f1d07SSam Ravnborg	select SWIOTLB
92323ac4ae8SAndreas Herrmann	depends on X86_64 && PCI && AMD_NB
924a7f7f624SMasahiro Yamada	help
925ced3c42cSIngo Molnar	  Provides a driver for older AMD Athlon64/Opteron/Turion/Sempron
926ced3c42cSIngo Molnar	  GART based hardware IOMMUs.
927ced3c42cSIngo Molnar
928ced3c42cSIngo Molnar	  The GART supports full DMA access for devices with 32-bit access
929ced3c42cSIngo Molnar	  limitations, on systems with more than 3 GB. This is usually needed
930ced3c42cSIngo Molnar	  for USB, sound, many IDE/SATA chipsets and some other devices.
931ced3c42cSIngo Molnar
932ced3c42cSIngo Molnar	  Newer systems typically have a modern AMD IOMMU, supported via
933ced3c42cSIngo Molnar	  the CONFIG_AMD_IOMMU=y config option.
934ced3c42cSIngo Molnar
935ced3c42cSIngo Molnar	  In normal configurations this driver is only active when needed:
936ced3c42cSIngo Molnar	  there's more than 3 GB of memory and the system contains a
937ced3c42cSIngo Molnar	  32-bit limited device.
938ced3c42cSIngo Molnar
939ced3c42cSIngo Molnar	  If unsure, say Y.
940506f1d07SSam Ravnborg
9411184dc2fSMike Travisconfig MAXSMP
942ddb0c5a6SSamuel Thibault	bool "Enable Maximum number of SMP Processors and NUMA Nodes"
9436ea30386SKees Cook	depends on X86_64 && SMP && DEBUG_KERNEL
94436f5101aSMike Travis	select CPUMASK_OFFSTACK
945a7f7f624SMasahiro Yamada	help
946ddb0c5a6SSamuel Thibault	  Enable maximum number of CPUS and NUMA Nodes for this architecture.
9471184dc2fSMike Travis	  If unsure, say N.
948506f1d07SSam Ravnborg
949aec6487eSIngo Molnar#
950aec6487eSIngo Molnar# The maximum number of CPUs supported:
951aec6487eSIngo Molnar#
952aec6487eSIngo Molnar# The main config value is NR_CPUS, which defaults to NR_CPUS_DEFAULT,
953aec6487eSIngo Molnar# and which can be configured interactively in the
954aec6487eSIngo Molnar# [NR_CPUS_RANGE_BEGIN ... NR_CPUS_RANGE_END] range.
955aec6487eSIngo Molnar#
956aec6487eSIngo Molnar# The ranges are different on 32-bit and 64-bit kernels, depending on
957aec6487eSIngo Molnar# hardware capabilities and scalability features of the kernel.
958aec6487eSIngo Molnar#
959aec6487eSIngo Molnar# ( If MAXSMP is enabled we just use the highest possible value and disable
960aec6487eSIngo Molnar#   interactive configuration. )
961aec6487eSIngo Molnar#
962a0d0bb4dSRandy Dunlap
963aec6487eSIngo Molnarconfig NR_CPUS_RANGE_BEGIN
964a0d0bb4dSRandy Dunlap	int
965aec6487eSIngo Molnar	default NR_CPUS_RANGE_END if MAXSMP
966a0d0bb4dSRandy Dunlap	default    1 if !SMP
967a0d0bb4dSRandy Dunlap	default    2
968a0d0bb4dSRandy Dunlap
969aec6487eSIngo Molnarconfig NR_CPUS_RANGE_END
970a0d0bb4dSRandy Dunlap	int
971a0d0bb4dSRandy Dunlap	depends on X86_32
972aec6487eSIngo Molnar	default   64 if  SMP &&  X86_BIGSMP
973aec6487eSIngo Molnar	default    8 if  SMP && !X86_BIGSMP
974a0d0bb4dSRandy Dunlap	default    1 if !SMP
975a0d0bb4dSRandy Dunlap
976aec6487eSIngo Molnarconfig NR_CPUS_RANGE_END
977a0d0bb4dSRandy Dunlap	int
978a0d0bb4dSRandy Dunlap	depends on X86_64
9791edae1aeSScott Wood	default 8192 if  SMP && CPUMASK_OFFSTACK
9801edae1aeSScott Wood	default  512 if  SMP && !CPUMASK_OFFSTACK
981a0d0bb4dSRandy Dunlap	default    1 if !SMP
982aec6487eSIngo Molnar
983aec6487eSIngo Molnarconfig NR_CPUS_DEFAULT
984aec6487eSIngo Molnar	int
985aec6487eSIngo Molnar	depends on X86_32
986aec6487eSIngo Molnar	default   32 if  X86_BIGSMP
987aec6487eSIngo Molnar	default    8 if  SMP
988aec6487eSIngo Molnar	default    1 if !SMP
989aec6487eSIngo Molnar
990aec6487eSIngo Molnarconfig NR_CPUS_DEFAULT
991aec6487eSIngo Molnar	int
992aec6487eSIngo Molnar	depends on X86_64
993a0d0bb4dSRandy Dunlap	default 8192 if  MAXSMP
994a0d0bb4dSRandy Dunlap	default   64 if  SMP
995aec6487eSIngo Molnar	default    1 if !SMP
996a0d0bb4dSRandy Dunlap
997506f1d07SSam Ravnborgconfig NR_CPUS
99836f5101aSMike Travis	int "Maximum number of CPUs" if SMP && !MAXSMP
999aec6487eSIngo Molnar	range NR_CPUS_RANGE_BEGIN NR_CPUS_RANGE_END
1000aec6487eSIngo Molnar	default NR_CPUS_DEFAULT
1001a7f7f624SMasahiro Yamada	help
1002506f1d07SSam Ravnborg	  This allows you to specify the maximum number of CPUs which this
1003bb61ccc7SJosh Boyer	  kernel will support.  If CPUMASK_OFFSTACK is enabled, the maximum
1004cad14bb9SKirill A. Shutemov	  supported value is 8192, otherwise the maximum value is 512.  The
1005506f1d07SSam Ravnborg	  minimum value which makes sense is 2.
1006506f1d07SSam Ravnborg
1007aec6487eSIngo Molnar	  This is purely to save memory: each supported CPU adds about 8KB
1008aec6487eSIngo Molnar	  to the kernel image.
1009506f1d07SSam Ravnborg
1010506f1d07SSam Ravnborgconfig SCHED_SMT
1011dbe73364SThomas Gleixner	def_bool y if SMP
1012506f1d07SSam Ravnborg
1013506f1d07SSam Ravnborgconfig SCHED_MC
10143c2362e6SHarvey Harrison	def_bool y
10153c2362e6SHarvey Harrison	prompt "Multi-core scheduler support"
1016c8e56d20SBorislav Petkov	depends on SMP
1017a7f7f624SMasahiro Yamada	help
1018506f1d07SSam Ravnborg	  Multi-core scheduler support improves the CPU scheduler's decision
1019506f1d07SSam Ravnborg	  making when dealing with multi-core CPU chips at a cost of slightly
1020506f1d07SSam Ravnborg	  increased overhead in some places. If unsure say N here.
1021506f1d07SSam Ravnborg
1022de966cf4STim Chenconfig SCHED_MC_PRIO
1023de966cf4STim Chen	bool "CPU core priorities scheduler support"
10240a21fc12SIngo Molnar	depends on SCHED_MC && CPU_SUP_INTEL
10250a21fc12SIngo Molnar	select X86_INTEL_PSTATE
10260a21fc12SIngo Molnar	select CPU_FREQ
1027de966cf4STim Chen	default y
1028a7f7f624SMasahiro Yamada	help
1029de966cf4STim Chen	  Intel Turbo Boost Max Technology 3.0 enabled CPUs have a
1030de966cf4STim Chen	  core ordering determined at manufacturing time, which allows
1031de966cf4STim Chen	  certain cores to reach higher turbo frequencies (when running
1032de966cf4STim Chen	  single threaded workloads) than others.
1033de966cf4STim Chen
1034de966cf4STim Chen	  Enabling this kernel feature teaches the scheduler about
1035de966cf4STim Chen	  the TBM3 (aka ITMT) priority order of the CPU cores and adjusts the
1036de966cf4STim Chen	  scheduler's CPU selection logic accordingly, so that higher
1037de966cf4STim Chen	  overall system performance can be achieved.
1038de966cf4STim Chen
1039de966cf4STim Chen	  This feature will have no effect on CPUs without this feature.
1040de966cf4STim Chen
1041de966cf4STim Chen	  If unsure say Y here.
10425e76b2abSTim Chen
104330b8b006SThomas Gleixnerconfig UP_LATE_INIT
104430b8b006SThomas Gleixner	def_bool y
1045ba360f88SThomas Gleixner	depends on !SMP && X86_LOCAL_APIC
104630b8b006SThomas Gleixner
1047506f1d07SSam Ravnborgconfig X86_UP_APIC
104850849eefSJan Beulich	bool "Local APIC support on uniprocessors" if !PCI_MSI
104950849eefSJan Beulich	default PCI_MSI
105038a1dfdaSBryan O'Donoghue	depends on X86_32 && !SMP && !X86_32_NON_STANDARD
1051a7f7f624SMasahiro Yamada	help
1052506f1d07SSam Ravnborg	  A local APIC (Advanced Programmable Interrupt Controller) is an
1053506f1d07SSam Ravnborg	  integrated interrupt controller in the CPU. If you have a single-CPU
1054506f1d07SSam Ravnborg	  system which has a processor with a local APIC, you can say Y here to
1055506f1d07SSam Ravnborg	  enable and use it. If you say Y here even though your machine doesn't
1056506f1d07SSam Ravnborg	  have a local APIC, then the kernel will still run with no slowdown at
1057506f1d07SSam Ravnborg	  all. The local APIC supports CPU-generated self-interrupts (timer,
1058506f1d07SSam Ravnborg	  performance counters), and the NMI watchdog which detects hard
1059506f1d07SSam Ravnborg	  lockups.
1060506f1d07SSam Ravnborg
1061506f1d07SSam Ravnborgconfig X86_UP_IOAPIC
1062506f1d07SSam Ravnborg	bool "IO-APIC support on uniprocessors"
1063506f1d07SSam Ravnborg	depends on X86_UP_APIC
1064a7f7f624SMasahiro Yamada	help
1065506f1d07SSam Ravnborg	  An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an
1066506f1d07SSam Ravnborg	  SMP-capable replacement for PC-style interrupt controllers. Most
1067506f1d07SSam Ravnborg	  SMP systems and many recent uniprocessor systems have one.
1068506f1d07SSam Ravnborg
1069506f1d07SSam Ravnborg	  If you have a single-CPU system with an IO-APIC, you can say Y here
1070506f1d07SSam Ravnborg	  to use it. If you say Y here even though your machine doesn't have
1071506f1d07SSam Ravnborg	  an IO-APIC, then the kernel will still run with no slowdown at all.
1072506f1d07SSam Ravnborg
1073506f1d07SSam Ravnborgconfig X86_LOCAL_APIC
10743c2362e6SHarvey Harrison	def_bool y
10750dbc6078SThomas Petazzoni	depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC || PCI_MSI
1076b5dc8e6cSJiang Liu	select IRQ_DOMAIN_HIERARCHY
107752f518a3SJiang Liu	select PCI_MSI_IRQ_DOMAIN if PCI_MSI
1078506f1d07SSam Ravnborg
1079506f1d07SSam Ravnborgconfig X86_IO_APIC
1080b1da1e71SJan Beulich	def_bool y
1081b1da1e71SJan Beulich	depends on X86_LOCAL_APIC || X86_UP_IOAPIC
1082506f1d07SSam Ravnborg
108341b9eb26SStefan Assmannconfig X86_REROUTE_FOR_BROKEN_BOOT_IRQS
108441b9eb26SStefan Assmann	bool "Reroute for broken boot IRQs"
108541b9eb26SStefan Assmann	depends on X86_IO_APIC
1086a7f7f624SMasahiro Yamada	help
108741b9eb26SStefan Assmann	  This option enables a workaround that fixes a source of
108841b9eb26SStefan Assmann	  spurious interrupts. This is recommended when threaded
108941b9eb26SStefan Assmann	  interrupt handling is used on systems where the generation of
109041b9eb26SStefan Assmann	  superfluous "boot interrupts" cannot be disabled.
109141b9eb26SStefan Assmann
109241b9eb26SStefan Assmann	  Some chipsets generate a legacy INTx "boot IRQ" when the IRQ
109341b9eb26SStefan Assmann	  entry in the chipset's IO-APIC is masked (as, e.g. the RT
109441b9eb26SStefan Assmann	  kernel does during interrupt handling). On chipsets where this
109541b9eb26SStefan Assmann	  boot IRQ generation cannot be disabled, this workaround keeps
109641b9eb26SStefan Assmann	  the original IRQ line masked so that only the equivalent "boot
109741b9eb26SStefan Assmann	  IRQ" is delivered to the CPUs. The workaround also tells the
109841b9eb26SStefan Assmann	  kernel to set up the IRQ handler on the boot IRQ line. In this
109941b9eb26SStefan Assmann	  way only one interrupt is delivered to the kernel. Otherwise
110041b9eb26SStefan Assmann	  the spurious second interrupt may cause the kernel to bring
110141b9eb26SStefan Assmann	  down (vital) interrupt lines.
110241b9eb26SStefan Assmann
110341b9eb26SStefan Assmann	  Only affects "broken" chipsets. Interrupt sharing may be
110441b9eb26SStefan Assmann	  increased on these systems.
110541b9eb26SStefan Assmann
1106506f1d07SSam Ravnborgconfig X86_MCE
1107bab9bc65SAndi Kleen	bool "Machine Check / overheating reporting"
1108648ed940SChen, Gong	select GENERIC_ALLOCATOR
1109e57dbaf7SBorislav Petkov	default y
1110a7f7f624SMasahiro Yamada	help
1111bab9bc65SAndi Kleen	  Machine Check support allows the processor to notify the
1112bab9bc65SAndi Kleen	  kernel if it detects a problem (e.g. overheating, data corruption).
1113506f1d07SSam Ravnborg	  The action the kernel takes depends on the severity of the problem,
1114bab9bc65SAndi Kleen	  ranging from warning messages to halting the machine.
11154efc0670SAndi Kleen
11165de97c9fSTony Luckconfig X86_MCELOG_LEGACY
11175de97c9fSTony Luck	bool "Support for deprecated /dev/mcelog character device"
11185de97c9fSTony Luck	depends on X86_MCE
1119a7f7f624SMasahiro Yamada	help
11205de97c9fSTony Luck	  Enable support for /dev/mcelog which is needed by the old mcelog
11215de97c9fSTony Luck	  userspace logging daemon. Consider switching to the new generation
11225de97c9fSTony Luck	  rasdaemon solution.
11235de97c9fSTony Luck
1124506f1d07SSam Ravnborgconfig X86_MCE_INTEL
11253c2362e6SHarvey Harrison	def_bool y
11263c2362e6SHarvey Harrison	prompt "Intel MCE features"
1127c1ebf835SAndi Kleen	depends on X86_MCE && X86_LOCAL_APIC
1128a7f7f624SMasahiro Yamada	help
1129506f1d07SSam Ravnborg	   Additional support for intel specific MCE features such as
1130506f1d07SSam Ravnborg	   the thermal monitor.
1131506f1d07SSam Ravnborg
1132506f1d07SSam Ravnborgconfig X86_MCE_AMD
11333c2362e6SHarvey Harrison	def_bool y
11343c2362e6SHarvey Harrison	prompt "AMD MCE features"
1135f5382de9SYazen Ghannam	depends on X86_MCE && X86_LOCAL_APIC && AMD_NB
1136a7f7f624SMasahiro Yamada	help
1137506f1d07SSam Ravnborg	   Additional support for AMD specific MCE features such as
1138506f1d07SSam Ravnborg	   the DRAM Error Threshold.
1139506f1d07SSam Ravnborg
11404efc0670SAndi Kleenconfig X86_ANCIENT_MCE
11416fc108a0SJan Beulich	bool "Support for old Pentium 5 / WinChip machine checks"
1142c31d9633SAndi Kleen	depends on X86_32 && X86_MCE
1143a7f7f624SMasahiro Yamada	help
11444efc0670SAndi Kleen	  Include support for machine check handling on old Pentium 5 or WinChip
11455065a706SMasanari Iida	  systems. These typically need to be enabled explicitly on the command
11464efc0670SAndi Kleen	  line.
11474efc0670SAndi Kleen
1148b2762686SAndi Kleenconfig X86_MCE_THRESHOLD
1149b2762686SAndi Kleen	depends on X86_MCE_AMD || X86_MCE_INTEL
11506fc108a0SJan Beulich	def_bool y
1151b2762686SAndi Kleen
1152ea149b36SAndi Kleenconfig X86_MCE_INJECT
1153bc8e80d5SBorislav Petkov	depends on X86_MCE && X86_LOCAL_APIC && DEBUG_FS
1154ea149b36SAndi Kleen	tristate "Machine check injector support"
1155a7f7f624SMasahiro Yamada	help
1156ea149b36SAndi Kleen	  Provide support for injecting machine checks for testing purposes.
1157ea149b36SAndi Kleen	  If you don't know what a machine check is and you don't do kernel
1158ea149b36SAndi Kleen	  QA it is safe to say n.
1159ea149b36SAndi Kleen
11604efc0670SAndi Kleenconfig X86_THERMAL_VECTOR
11614efc0670SAndi Kleen	def_bool y
11625bb38adcSAndi Kleen	depends on X86_MCE_INTEL
11634efc0670SAndi Kleen
116407dc900eSPeter Zijlstrasource "arch/x86/events/Kconfig"
1165e633c65aSKan Liang
11665aef51c3SAndy Lutomirskiconfig X86_LEGACY_VM86
11671e642812SIngo Molnar	bool "Legacy VM86 support"
1168506f1d07SSam Ravnborg	depends on X86_32
1169a7f7f624SMasahiro Yamada	help
11705aef51c3SAndy Lutomirski	  This option allows user programs to put the CPU into V8086
11715aef51c3SAndy Lutomirski	  mode, which is an 80286-era approximation of 16-bit real mode.
11725aef51c3SAndy Lutomirski
11735aef51c3SAndy Lutomirski	  Some very old versions of X and/or vbetool require this option
11745aef51c3SAndy Lutomirski	  for user mode setting.  Similarly, DOSEMU will use it if
11755aef51c3SAndy Lutomirski	  available to accelerate real mode DOS programs.  However, any
11765aef51c3SAndy Lutomirski	  recent version of DOSEMU, X, or vbetool should be fully
11775aef51c3SAndy Lutomirski	  functional even without kernel VM86 support, as they will all
11781e642812SIngo Molnar	  fall back to software emulation. Nevertheless, if you are using
11791e642812SIngo Molnar	  a 16-bit DOS program where 16-bit performance matters, vm86
11801e642812SIngo Molnar	  mode might be faster than emulation and you might want to
11811e642812SIngo Molnar	  enable this option.
11825aef51c3SAndy Lutomirski
11831e642812SIngo Molnar	  Note that any app that works on a 64-bit kernel is unlikely to
11841e642812SIngo Molnar	  need this option, as 64-bit kernels don't, and can't, support
11851e642812SIngo Molnar	  V8086 mode. This option is also unrelated to 16-bit protected
11861e642812SIngo Molnar	  mode and is not needed to run most 16-bit programs under Wine.
11875aef51c3SAndy Lutomirski
11881e642812SIngo Molnar	  Enabling this option increases the complexity of the kernel
11891e642812SIngo Molnar	  and slows down exception handling a tiny bit.
11905aef51c3SAndy Lutomirski
11911e642812SIngo Molnar	  If unsure, say N here.
11925aef51c3SAndy Lutomirski
11935aef51c3SAndy Lutomirskiconfig VM86
11945aef51c3SAndy Lutomirski	bool
11955aef51c3SAndy Lutomirski	default X86_LEGACY_VM86
119634273f41SH. Peter Anvin
119734273f41SH. Peter Anvinconfig X86_16BIT
119834273f41SH. Peter Anvin	bool "Enable support for 16-bit segments" if EXPERT
119934273f41SH. Peter Anvin	default y
1200a5b9e5a2SAndy Lutomirski	depends on MODIFY_LDT_SYSCALL
1201a7f7f624SMasahiro Yamada	help
120234273f41SH. Peter Anvin	  This option is required by programs like Wine to run 16-bit
120334273f41SH. Peter Anvin	  protected mode legacy code on x86 processors.  Disabling
120434273f41SH. Peter Anvin	  this option saves about 300 bytes on i386, or around 6K text
120534273f41SH. Peter Anvin	  plus 16K runtime memory on x86-64,
120634273f41SH. Peter Anvin
120734273f41SH. Peter Anvinconfig X86_ESPFIX32
120834273f41SH. Peter Anvin	def_bool y
120934273f41SH. Peter Anvin	depends on X86_16BIT && X86_32
1210506f1d07SSam Ravnborg
1211197725deSH. Peter Anvinconfig X86_ESPFIX64
1212197725deSH. Peter Anvin	def_bool y
121334273f41SH. Peter Anvin	depends on X86_16BIT && X86_64
1214506f1d07SSam Ravnborg
12151ad83c85SAndy Lutomirskiconfig X86_VSYSCALL_EMULATION
12161ad83c85SAndy Lutomirski	bool "Enable vsyscall emulation" if EXPERT
12171ad83c85SAndy Lutomirski	default y
12181ad83c85SAndy Lutomirski	depends on X86_64
1219a7f7f624SMasahiro Yamada	help
12201ad83c85SAndy Lutomirski	 This enables emulation of the legacy vsyscall page.  Disabling
12211ad83c85SAndy Lutomirski	 it is roughly equivalent to booting with vsyscall=none, except
12221ad83c85SAndy Lutomirski	 that it will also disable the helpful warning if a program
12231ad83c85SAndy Lutomirski	 tries to use a vsyscall.  With this option set to N, offending
12241ad83c85SAndy Lutomirski	 programs will just segfault, citing addresses of the form
12251ad83c85SAndy Lutomirski	 0xffffffffff600?00.
12261ad83c85SAndy Lutomirski
12271ad83c85SAndy Lutomirski	 This option is required by many programs built before 2013, and
12281ad83c85SAndy Lutomirski	 care should be used even with newer programs if set to N.
12291ad83c85SAndy Lutomirski
12301ad83c85SAndy Lutomirski	 Disabling this option saves about 7K of kernel size and
12311ad83c85SAndy Lutomirski	 possibly 4K of additional runtime pagetable memory.
12321ad83c85SAndy Lutomirski
1233111e7b15SThomas Gleixnerconfig X86_IOPL_IOPERM
1234111e7b15SThomas Gleixner	bool "IOPERM and IOPL Emulation"
1235a24ca997SThomas Gleixner	default y
1236a7f7f624SMasahiro Yamada	help
1237111e7b15SThomas Gleixner	  This enables the ioperm() and iopl() syscalls which are necessary
1238111e7b15SThomas Gleixner	  for legacy applications.
1239111e7b15SThomas Gleixner
1240c8137aceSThomas Gleixner	  Legacy IOPL support is an overbroad mechanism which allows user
1241c8137aceSThomas Gleixner	  space aside of accessing all 65536 I/O ports also to disable
1242c8137aceSThomas Gleixner	  interrupts. To gain this access the caller needs CAP_SYS_RAWIO
1243c8137aceSThomas Gleixner	  capabilities and permission from potentially active security
1244c8137aceSThomas Gleixner	  modules.
1245c8137aceSThomas Gleixner
1246c8137aceSThomas Gleixner	  The emulation restricts the functionality of the syscall to
1247c8137aceSThomas Gleixner	  only allowing the full range I/O port access, but prevents the
1248a24ca997SThomas Gleixner	  ability to disable interrupts from user space which would be
1249a24ca997SThomas Gleixner	  granted if the hardware IOPL mechanism would be used.
1250c8137aceSThomas Gleixner
1251506f1d07SSam Ravnborgconfig TOSHIBA
1252506f1d07SSam Ravnborg	tristate "Toshiba Laptop support"
1253506f1d07SSam Ravnborg	depends on X86_32
1254a7f7f624SMasahiro Yamada	help
1255506f1d07SSam Ravnborg	  This adds a driver to safely access the System Management Mode of
1256506f1d07SSam Ravnborg	  the CPU on Toshiba portables with a genuine Toshiba BIOS. It does
1257506f1d07SSam Ravnborg	  not work on models with a Phoenix BIOS. The System Management Mode
1258506f1d07SSam Ravnborg	  is used to set the BIOS and power saving options on Toshiba portables.
1259506f1d07SSam Ravnborg
1260506f1d07SSam Ravnborg	  For information on utilities to make use of this driver see the
1261506f1d07SSam Ravnborg	  Toshiba Linux utilities web site at:
1262506f1d07SSam Ravnborg	  <http://www.buzzard.org.uk/toshiba/>.
1263506f1d07SSam Ravnborg
1264506f1d07SSam Ravnborg	  Say Y if you intend to run this kernel on a Toshiba portable.
1265506f1d07SSam Ravnborg	  Say N otherwise.
1266506f1d07SSam Ravnborg
1267506f1d07SSam Ravnborgconfig I8K
1268039ae585SPali Rohár	tristate "Dell i8k legacy laptop support"
1269949a9d70SJean Delvare	select HWMON
1270039ae585SPali Rohár	select SENSORS_DELL_SMM
1271a7f7f624SMasahiro Yamada	help
1272039ae585SPali Rohár	  This option enables legacy /proc/i8k userspace interface in hwmon
1273039ae585SPali Rohár	  dell-smm-hwmon driver. Character file /proc/i8k reports bios version,
1274039ae585SPali Rohár	  temperature and allows controlling fan speeds of Dell laptops via
1275039ae585SPali Rohár	  System Management Mode. For old Dell laptops (like Dell Inspiron 8000)
1276039ae585SPali Rohár	  it reports also power and hotkey status. For fan speed control is
1277039ae585SPali Rohár	  needed userspace package i8kutils.
1278506f1d07SSam Ravnborg
1279039ae585SPali Rohár	  Say Y if you intend to run this kernel on old Dell laptops or want to
1280039ae585SPali Rohár	  use userspace package i8kutils.
1281506f1d07SSam Ravnborg	  Say N otherwise.
1282506f1d07SSam Ravnborg
1283506f1d07SSam Ravnborgconfig X86_REBOOTFIXUPS
12849ba16087SJan Beulich	bool "Enable X86 board specific fixups for reboot"
12859ba16087SJan Beulich	depends on X86_32
1286a7f7f624SMasahiro Yamada	help
1287506f1d07SSam Ravnborg	  This enables chipset and/or board specific fixups to be done
1288506f1d07SSam Ravnborg	  in order to get reboot to work correctly. This is only needed on
1289506f1d07SSam Ravnborg	  some combinations of hardware and BIOS. The symptom, for which
1290506f1d07SSam Ravnborg	  this config is intended, is when reboot ends with a stalled/hung
1291506f1d07SSam Ravnborg	  system.
1292506f1d07SSam Ravnborg
1293506f1d07SSam Ravnborg	  Currently, the only fixup is for the Geode machines using
12945e3a77e9SFlorian Fainelli	  CS5530A and CS5536 chipsets and the RDC R-321x SoC.
1295506f1d07SSam Ravnborg
1296506f1d07SSam Ravnborg	  Say Y if you want to enable the fixup. Currently, it's safe to
1297506f1d07SSam Ravnborg	  enable this option even if you don't need it.
1298506f1d07SSam Ravnborg	  Say N otherwise.
1299506f1d07SSam Ravnborg
1300506f1d07SSam Ravnborgconfig MICROCODE
13019a2bc335SBorislav Petkov	bool "CPU microcode loading support"
13029a2bc335SBorislav Petkov	default y
130380030e3dSBorislav Petkov	depends on CPU_SUP_AMD || CPU_SUP_INTEL
1304a7f7f624SMasahiro Yamada	help
1305506f1d07SSam Ravnborg	  If you say Y here, you will be able to update the microcode on
13065f9c01aaSBorislav Petkov	  Intel and AMD processors. The Intel support is for the IA32 family,
13075f9c01aaSBorislav Petkov	  e.g. Pentium Pro, Pentium II, Pentium III, Pentium 4, Xeon etc. The
13085f9c01aaSBorislav Petkov	  AMD support is for families 0x10 and later. You will obviously need
13095f9c01aaSBorislav Petkov	  the actual microcode binary data itself which is not shipped with
13105f9c01aaSBorislav Petkov	  the Linux kernel.
1311506f1d07SSam Ravnborg
13125f9c01aaSBorislav Petkov	  The preferred method to load microcode from a detached initrd is described
1313cb1aaebeSMauro Carvalho Chehab	  in Documentation/x86/microcode.rst. For that you need to enable
13145f9c01aaSBorislav Petkov	  CONFIG_BLK_DEV_INITRD in order for the loader to be able to scan the
13155f9c01aaSBorislav Petkov	  initrd for microcode blobs.
1316506f1d07SSam Ravnborg
1317c508c46eSBenjamin Gilbert	  In addition, you can build the microcode into the kernel. For that you
1318c508c46eSBenjamin Gilbert	  need to add the vendor-supplied microcode to the CONFIG_EXTRA_FIRMWARE
1319c508c46eSBenjamin Gilbert	  config option.
1320506f1d07SSam Ravnborg
13218d86f390SPeter Orubaconfig MICROCODE_INTEL
1322e43f6e67SBorislav Petkov	bool "Intel microcode loading support"
13238d86f390SPeter Oruba	depends on MICROCODE
13248d86f390SPeter Oruba	default MICROCODE
1325a7f7f624SMasahiro Yamada	help
13268d86f390SPeter Oruba	  This options enables microcode patch loading support for Intel
13278d86f390SPeter Oruba	  processors.
13288d86f390SPeter Oruba
1329b8989db9SAlan	  For the current Intel microcode data package go to
1330b8989db9SAlan	  <https://downloadcenter.intel.com> and search for
1331b8989db9SAlan	  'Linux Processor Microcode Data File'.
13328d86f390SPeter Oruba
133380cc9f10SPeter Orubaconfig MICROCODE_AMD
1334e43f6e67SBorislav Petkov	bool "AMD microcode loading support"
133580cc9f10SPeter Oruba	depends on MICROCODE
1336a7f7f624SMasahiro Yamada	help
133780cc9f10SPeter Oruba	  If you select this option, microcode patch loading support for AMD
133880cc9f10SPeter Oruba	  processors will be enabled.
133980cc9f10SPeter Oruba
1340506f1d07SSam Ravnborgconfig MICROCODE_OLD_INTERFACE
1341c02f48e0SBorislav Petkov	bool "Ancient loading interface (DEPRECATED)"
1342c02f48e0SBorislav Petkov	default n
1343506f1d07SSam Ravnborg	depends on MICROCODE
1344a7f7f624SMasahiro Yamada	help
1345c02f48e0SBorislav Petkov	  DO NOT USE THIS! This is the ancient /dev/cpu/microcode interface
1346c02f48e0SBorislav Petkov	  which was used by userspace tools like iucode_tool and microcode.ctl.
1347c02f48e0SBorislav Petkov	  It is inadequate because it runs too late to be able to properly
1348c02f48e0SBorislav Petkov	  load microcode on a machine and it needs special tools. Instead, you
1349c02f48e0SBorislav Petkov	  should've switched to the early loading method with the initrd or
1350cb1aaebeSMauro Carvalho Chehab	  builtin microcode by now: Documentation/x86/microcode.rst
1351506f1d07SSam Ravnborg
1352506f1d07SSam Ravnborgconfig X86_MSR
1353506f1d07SSam Ravnborg	tristate "/dev/cpu/*/msr - Model-specific register support"
1354a7f7f624SMasahiro Yamada	help
1355506f1d07SSam Ravnborg	  This device gives privileged processes access to the x86
1356506f1d07SSam Ravnborg	  Model-Specific Registers (MSRs).  It is a character device with
1357506f1d07SSam Ravnborg	  major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr.
1358506f1d07SSam Ravnborg	  MSR accesses are directed to a specific CPU on multi-processor
1359506f1d07SSam Ravnborg	  systems.
1360506f1d07SSam Ravnborg
1361506f1d07SSam Ravnborgconfig X86_CPUID
1362506f1d07SSam Ravnborg	tristate "/dev/cpu/*/cpuid - CPU information support"
1363a7f7f624SMasahiro Yamada	help
1364506f1d07SSam Ravnborg	  This device gives processes access to the x86 CPUID instruction to
1365506f1d07SSam Ravnborg	  be executed on a specific processor.  It is a character device
1366506f1d07SSam Ravnborg	  with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to
1367506f1d07SSam Ravnborg	  /dev/cpu/31/cpuid.
1368506f1d07SSam Ravnborg
1369506f1d07SSam Ravnborgchoice
1370506f1d07SSam Ravnborg	prompt "High Memory Support"
13716fc108a0SJan Beulich	default HIGHMEM4G
1372506f1d07SSam Ravnborg	depends on X86_32
1373506f1d07SSam Ravnborg
1374506f1d07SSam Ravnborgconfig NOHIGHMEM
1375506f1d07SSam Ravnborg	bool "off"
1376a7f7f624SMasahiro Yamada	help
1377506f1d07SSam Ravnborg	  Linux can use up to 64 Gigabytes of physical memory on x86 systems.
1378506f1d07SSam Ravnborg	  However, the address space of 32-bit x86 processors is only 4
1379506f1d07SSam Ravnborg	  Gigabytes large. That means that, if you have a large amount of
1380506f1d07SSam Ravnborg	  physical memory, not all of it can be "permanently mapped" by the
1381506f1d07SSam Ravnborg	  kernel. The physical memory that's not permanently mapped is called
1382506f1d07SSam Ravnborg	  "high memory".
1383506f1d07SSam Ravnborg
1384506f1d07SSam Ravnborg	  If you are compiling a kernel which will never run on a machine with
1385506f1d07SSam Ravnborg	  more than 1 Gigabyte total physical RAM, answer "off" here (default
1386506f1d07SSam Ravnborg	  choice and suitable for most users). This will result in a "3GB/1GB"
1387506f1d07SSam Ravnborg	  split: 3GB are mapped so that each process sees a 3GB virtual memory
1388506f1d07SSam Ravnborg	  space and the remaining part of the 4GB virtual memory space is used
1389506f1d07SSam Ravnborg	  by the kernel to permanently map as much physical memory as
1390506f1d07SSam Ravnborg	  possible.
1391506f1d07SSam Ravnborg
1392506f1d07SSam Ravnborg	  If the machine has between 1 and 4 Gigabytes physical RAM, then
1393506f1d07SSam Ravnborg	  answer "4GB" here.
1394506f1d07SSam Ravnborg
1395506f1d07SSam Ravnborg	  If more than 4 Gigabytes is used then answer "64GB" here. This
1396506f1d07SSam Ravnborg	  selection turns Intel PAE (Physical Address Extension) mode on.
1397506f1d07SSam Ravnborg	  PAE implements 3-level paging on IA32 processors. PAE is fully
1398506f1d07SSam Ravnborg	  supported by Linux, PAE mode is implemented on all recent Intel
1399506f1d07SSam Ravnborg	  processors (Pentium Pro and better). NOTE: If you say "64GB" here,
1400506f1d07SSam Ravnborg	  then the kernel will not boot on CPUs that don't support PAE!
1401506f1d07SSam Ravnborg
1402506f1d07SSam Ravnborg	  The actual amount of total physical memory will either be
1403506f1d07SSam Ravnborg	  auto detected or can be forced by using a kernel command line option
1404506f1d07SSam Ravnborg	  such as "mem=256M". (Try "man bootparam" or see the documentation of
1405506f1d07SSam Ravnborg	  your boot loader (lilo or loadlin) about how to pass options to the
1406506f1d07SSam Ravnborg	  kernel at boot time.)
1407506f1d07SSam Ravnborg
1408506f1d07SSam Ravnborg	  If unsure, say "off".
1409506f1d07SSam Ravnborg
1410506f1d07SSam Ravnborgconfig HIGHMEM4G
1411506f1d07SSam Ravnborg	bool "4GB"
1412a7f7f624SMasahiro Yamada	help
1413506f1d07SSam Ravnborg	  Select this if you have a 32-bit processor and between 1 and 4
1414506f1d07SSam Ravnborg	  gigabytes of physical RAM.
1415506f1d07SSam Ravnborg
1416506f1d07SSam Ravnborgconfig HIGHMEM64G
1417506f1d07SSam Ravnborg	bool "64GB"
141869b8d3fcSMatthew Whitehead	depends on !M486 && !M586 && !M586TSC && !M586MMX && !MGEODE_LX && !MGEODEGX1 && !MCYRIXIII && !MELAN && !MWINCHIPC6 && !WINCHIP3D && !MK6
1419506f1d07SSam Ravnborg	select X86_PAE
1420a7f7f624SMasahiro Yamada	help
1421506f1d07SSam Ravnborg	  Select this if you have a 32-bit processor and more than 4
1422506f1d07SSam Ravnborg	  gigabytes of physical RAM.
1423506f1d07SSam Ravnborg
1424506f1d07SSam Ravnborgendchoice
1425506f1d07SSam Ravnborg
1426506f1d07SSam Ravnborgchoice
14276a108a14SDavid Rientjes	prompt "Memory split" if EXPERT
1428506f1d07SSam Ravnborg	default VMSPLIT_3G
1429506f1d07SSam Ravnborg	depends on X86_32
1430a7f7f624SMasahiro Yamada	help
1431506f1d07SSam Ravnborg	  Select the desired split between kernel and user memory.
1432506f1d07SSam Ravnborg
1433506f1d07SSam Ravnborg	  If the address range available to the kernel is less than the
1434506f1d07SSam Ravnborg	  physical memory installed, the remaining memory will be available
1435506f1d07SSam Ravnborg	  as "high memory". Accessing high memory is a little more costly
1436506f1d07SSam Ravnborg	  than low memory, as it needs to be mapped into the kernel first.
1437506f1d07SSam Ravnborg	  Note that increasing the kernel address space limits the range
1438506f1d07SSam Ravnborg	  available to user programs, making the address space there
1439506f1d07SSam Ravnborg	  tighter.  Selecting anything other than the default 3G/1G split
1440506f1d07SSam Ravnborg	  will also likely make your kernel incompatible with binary-only
1441506f1d07SSam Ravnborg	  kernel modules.
1442506f1d07SSam Ravnborg
1443506f1d07SSam Ravnborg	  If you are not absolutely sure what you are doing, leave this
1444506f1d07SSam Ravnborg	  option alone!
1445506f1d07SSam Ravnborg
1446506f1d07SSam Ravnborg	config VMSPLIT_3G
1447506f1d07SSam Ravnborg		bool "3G/1G user/kernel split"
1448506f1d07SSam Ravnborg	config VMSPLIT_3G_OPT
1449506f1d07SSam Ravnborg		depends on !X86_PAE
1450506f1d07SSam Ravnborg		bool "3G/1G user/kernel split (for full 1G low memory)"
1451506f1d07SSam Ravnborg	config VMSPLIT_2G
1452506f1d07SSam Ravnborg		bool "2G/2G user/kernel split"
1453506f1d07SSam Ravnborg	config VMSPLIT_2G_OPT
1454506f1d07SSam Ravnborg		depends on !X86_PAE
1455506f1d07SSam Ravnborg		bool "2G/2G user/kernel split (for full 2G low memory)"
1456506f1d07SSam Ravnborg	config VMSPLIT_1G
1457506f1d07SSam Ravnborg		bool "1G/3G user/kernel split"
1458506f1d07SSam Ravnborgendchoice
1459506f1d07SSam Ravnborg
1460506f1d07SSam Ravnborgconfig PAGE_OFFSET
1461506f1d07SSam Ravnborg	hex
1462506f1d07SSam Ravnborg	default 0xB0000000 if VMSPLIT_3G_OPT
1463506f1d07SSam Ravnborg	default 0x80000000 if VMSPLIT_2G
1464506f1d07SSam Ravnborg	default 0x78000000 if VMSPLIT_2G_OPT
1465506f1d07SSam Ravnborg	default 0x40000000 if VMSPLIT_1G
1466506f1d07SSam Ravnborg	default 0xC0000000
1467506f1d07SSam Ravnborg	depends on X86_32
1468506f1d07SSam Ravnborg
1469506f1d07SSam Ravnborgconfig HIGHMEM
14703c2362e6SHarvey Harrison	def_bool y
1471506f1d07SSam Ravnborg	depends on X86_32 && (HIGHMEM64G || HIGHMEM4G)
1472506f1d07SSam Ravnborg
1473506f1d07SSam Ravnborgconfig X86_PAE
14749ba16087SJan Beulich	bool "PAE (Physical Address Extension) Support"
1475506f1d07SSam Ravnborg	depends on X86_32 && !HIGHMEM4G
1476d4a451d5SChristoph Hellwig	select PHYS_ADDR_T_64BIT
14779d99c712SChristian Melki	select SWIOTLB
1478a7f7f624SMasahiro Yamada	help
1479506f1d07SSam Ravnborg	  PAE is required for NX support, and furthermore enables
1480506f1d07SSam Ravnborg	  larger swapspace support for non-overcommit purposes. It
1481506f1d07SSam Ravnborg	  has the cost of more pagetable lookup overhead, and also
1482506f1d07SSam Ravnborg	  consumes more pagetable space per process.
1483506f1d07SSam Ravnborg
148477ef56e4SKirill A. Shutemovconfig X86_5LEVEL
148577ef56e4SKirill A. Shutemov	bool "Enable 5-level page tables support"
148618ec1eafSKirill A. Shutemov	default y
1487eedb92abSKirill A. Shutemov	select DYNAMIC_MEMORY_LAYOUT
1488162434e7SKirill A. Shutemov	select SPARSEMEM_VMEMMAP
148977ef56e4SKirill A. Shutemov	depends on X86_64
1490a7f7f624SMasahiro Yamada	help
149177ef56e4SKirill A. Shutemov	  5-level paging enables access to larger address space:
149277ef56e4SKirill A. Shutemov	  upto 128 PiB of virtual address space and 4 PiB of
149377ef56e4SKirill A. Shutemov	  physical address space.
149477ef56e4SKirill A. Shutemov
149577ef56e4SKirill A. Shutemov	  It will be supported by future Intel CPUs.
149677ef56e4SKirill A. Shutemov
14976657fca0SKirill A. Shutemov	  A kernel with the option enabled can be booted on machines that
14986657fca0SKirill A. Shutemov	  support 4- or 5-level paging.
149977ef56e4SKirill A. Shutemov
1500cb1aaebeSMauro Carvalho Chehab	  See Documentation/x86/x86_64/5level-paging.rst for more
150177ef56e4SKirill A. Shutemov	  information.
150277ef56e4SKirill A. Shutemov
150377ef56e4SKirill A. Shutemov	  Say N if unsure.
150477ef56e4SKirill A. Shutemov
150510971ab2SIngo Molnarconfig X86_DIRECT_GBPAGES
1506e5008abeSLuis R. Rodriguez	def_bool y
15072e1da13fSVlastimil Babka	depends on X86_64
1508a7f7f624SMasahiro Yamada	help
150910971ab2SIngo Molnar	  Certain kernel features effectively disable kernel
151010971ab2SIngo Molnar	  linear 1 GB mappings (even if the CPU otherwise
151110971ab2SIngo Molnar	  supports them), so don't confuse the user by printing
151210971ab2SIngo Molnar	  that we have them enabled.
15139e899816SNick Piggin
15145c280cf6SThomas Gleixnerconfig X86_CPA_STATISTICS
15155c280cf6SThomas Gleixner	bool "Enable statistic for Change Page Attribute"
15165c280cf6SThomas Gleixner	depends on DEBUG_FS
1517a7f7f624SMasahiro Yamada	help
1518b75baaf3SIngo Molnar	  Expose statistics about the Change Page Attribute mechanism, which
1519a943245aSColin Ian King	  helps to determine the effectiveness of preserving large and huge
15205c280cf6SThomas Gleixner	  page mappings when mapping protections are changed.
15215c280cf6SThomas Gleixner
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
152694d49eb3SKirill A. Shutemov	select DYNAMIC_PHYSICAL_MASK
1527ce9084baSArd Biesheuvel	select ARCH_USE_MEMREMAP_PROT
15289087c375STom Lendacky	select ARCH_HAS_FORCE_DMA_UNENCRYPTED
1529597cfe48SJoerg Roedel	select INSTRUCTION_DECODER
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	default y
15387744ccdbSTom Lendacky	depends on AMD_MEM_ENCRYPT
1539a7f7f624SMasahiro Yamada	help
15407744ccdbSTom Lendacky	  Say yes to have system memory encrypted by default if running on
15417744ccdbSTom Lendacky	  an AMD processor that supports Secure Memory Encryption (SME).
15427744ccdbSTom Lendacky
15437744ccdbSTom Lendacky	  If set to Y, then the encryption of system memory can be
15447744ccdbSTom Lendacky	  deactivated with the mem_encrypt=off command line option.
15457744ccdbSTom Lendacky
15467744ccdbSTom Lendacky	  If set to N, then the encryption of system memory can be
15477744ccdbSTom Lendacky	  activated with the mem_encrypt=on command line option.
15487744ccdbSTom Lendacky
1549506f1d07SSam Ravnborg# Common NUMA Features
1550506f1d07SSam Ravnborgconfig NUMA
1551e133f6eaSRandy Dunlap	bool "NUMA Memory Allocation and Scheduler Support"
1552506f1d07SSam Ravnborg	depends on SMP
1553b5660ba7SH. Peter Anvin	depends on X86_64 || (X86_32 && HIGHMEM64G && X86_BIGSMP)
1554b5660ba7SH. Peter Anvin	default y if X86_BIGSMP
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"
1603506f1d07SSam Ravnborg	depends on NEED_MULTIPLE_NODES
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
1623b263295dSChristoph Lameter	depends on ARCH_SPARSEMEM_ENABLE
1624506f1d07SSam Ravnborg
1625506f1d07SSam Ravnborgconfig ARCH_MEMORY_PROBE
1626a0842b70SToshi Kani	bool "Enable sysfs memory/probe interface"
16273120e25eSJan Beulich	depends on X86_64 && 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
16999ea77bdbSH. Peter Anvinconfig X86_RESERVE_LOW
1700d0cd7425SH. Peter Anvin	int "Amount of low memory, in kilobytes, to reserve for the BIOS"
1701d0cd7425SH. Peter Anvin	default 64
1702d0cd7425SH. Peter Anvin	range 4 640
1703a7f7f624SMasahiro Yamada	help
1704d0cd7425SH. Peter Anvin	  Specify the amount of low memory to reserve for the BIOS.
1705fc381519SIngo Molnar
1706d0cd7425SH. Peter Anvin	  The first page contains BIOS data structures that the kernel
1707d0cd7425SH. Peter Anvin	  must not use, so that page must always be reserved.
1708fc381519SIngo Molnar
1709d0cd7425SH. Peter Anvin	  By default we reserve the first 64K of physical RAM, as a
1710d0cd7425SH. Peter Anvin	  number of BIOSes are known to corrupt that memory range
1711d0cd7425SH. Peter Anvin	  during events such as suspend/resume or monitor cable
1712d0cd7425SH. Peter Anvin	  insertion, so it must not be used by the kernel.
1713fc381519SIngo Molnar
1714d0cd7425SH. Peter Anvin	  You can set this to 4 if you are absolutely sure that you
1715d0cd7425SH. Peter Anvin	  trust the BIOS to get all its memory reservations and usages
1716d0cd7425SH. Peter Anvin	  right.  If you know your BIOS have problems beyond the
1717d0cd7425SH. Peter Anvin	  default 64K area, you can set this to 640 to avoid using the
1718d0cd7425SH. Peter Anvin	  entire low memory range.
1719d0cd7425SH. Peter Anvin
1720d0cd7425SH. Peter Anvin	  If you have doubts about the BIOS (e.g. suspend/resume does
1721d0cd7425SH. Peter Anvin	  not work or there's kernel crashes after certain hardware
1722d0cd7425SH. Peter Anvin	  hotplug events) then you might want to enable
1723d0cd7425SH. Peter Anvin	  X86_CHECK_BIOS_CORRUPTION=y to allow the kernel to check
1724d0cd7425SH. Peter Anvin	  typical corruption patterns.
1725d0cd7425SH. Peter Anvin
1726d0cd7425SH. Peter Anvin	  Leave this to the default value of 64 if you are unsure.
1727fc381519SIngo Molnar
1728506f1d07SSam Ravnborgconfig MATH_EMULATION
1729506f1d07SSam Ravnborg	bool
1730a5b9e5a2SAndy Lutomirski	depends on MODIFY_LDT_SYSCALL
173187d6021bSArnd Bergmann	prompt "Math emulation" if X86_32 && (M486SX || MELAN)
1732a7f7f624SMasahiro Yamada	help
1733506f1d07SSam Ravnborg	  Linux can emulate a math coprocessor (used for floating point
1734506f1d07SSam Ravnborg	  operations) if you don't have one. 486DX and Pentium processors have
1735506f1d07SSam Ravnborg	  a math coprocessor built in, 486SX and 386 do not, unless you added
1736506f1d07SSam Ravnborg	  a 487DX or 387, respectively. (The messages during boot time can
1737506f1d07SSam Ravnborg	  give you some hints here ["man dmesg"].) Everyone needs either a
1738506f1d07SSam Ravnborg	  coprocessor or this emulation.
1739506f1d07SSam Ravnborg
1740506f1d07SSam Ravnborg	  If you don't have a math coprocessor, you need to say Y here; if you
1741506f1d07SSam Ravnborg	  say Y here even though you have a coprocessor, the coprocessor will
1742506f1d07SSam Ravnborg	  be used nevertheless. (This behavior can be changed with the kernel
1743506f1d07SSam Ravnborg	  command line option "no387", which comes handy if your coprocessor
1744506f1d07SSam Ravnborg	  is broken. Try "man bootparam" or see the documentation of your boot
1745506f1d07SSam Ravnborg	  loader (lilo or loadlin) about how to pass options to the kernel at
1746506f1d07SSam Ravnborg	  boot time.) This means that it is a good idea to say Y here if you
1747506f1d07SSam Ravnborg	  intend to use this kernel on different machines.
1748506f1d07SSam Ravnborg
1749506f1d07SSam Ravnborg	  More information about the internals of the Linux math coprocessor
1750506f1d07SSam Ravnborg	  emulation can be found in <file:arch/x86/math-emu/README>.
1751506f1d07SSam Ravnborg
1752506f1d07SSam Ravnborg	  If you are not sure, say Y; apart from resulting in a 66 KB bigger
1753506f1d07SSam Ravnborg	  kernel, it won't hurt.
1754506f1d07SSam Ravnborg
1755506f1d07SSam Ravnborgconfig MTRR
17566fc108a0SJan Beulich	def_bool y
17576a108a14SDavid Rientjes	prompt "MTRR (Memory Type Range Register) support" if EXPERT
1758a7f7f624SMasahiro Yamada	help
1759506f1d07SSam Ravnborg	  On Intel P6 family processors (Pentium Pro, Pentium II and later)
1760506f1d07SSam Ravnborg	  the Memory Type Range Registers (MTRRs) may be used to control
1761506f1d07SSam Ravnborg	  processor access to memory ranges. This is most useful if you have
1762506f1d07SSam Ravnborg	  a video (VGA) card on a PCI or AGP bus. Enabling write-combining
1763506f1d07SSam Ravnborg	  allows bus write transfers to be combined into a larger transfer
1764506f1d07SSam Ravnborg	  before bursting over the PCI/AGP bus. This can increase performance
1765506f1d07SSam Ravnborg	  of image write operations 2.5 times or more. Saying Y here creates a
1766506f1d07SSam Ravnborg	  /proc/mtrr file which may be used to manipulate your processor's
1767506f1d07SSam Ravnborg	  MTRRs. Typically the X server should use this.
1768506f1d07SSam Ravnborg
1769506f1d07SSam Ravnborg	  This code has a reasonably generic interface so that similar
1770506f1d07SSam Ravnborg	  control registers on other processors can be easily supported
1771506f1d07SSam Ravnborg	  as well:
1772506f1d07SSam Ravnborg
1773506f1d07SSam Ravnborg	  The Cyrix 6x86, 6x86MX and M II processors have Address Range
1774506f1d07SSam Ravnborg	  Registers (ARRs) which provide a similar functionality to MTRRs. For
1775506f1d07SSam Ravnborg	  these, the ARRs are used to emulate the MTRRs.
1776506f1d07SSam Ravnborg	  The AMD K6-2 (stepping 8 and above) and K6-3 processors have two
1777506f1d07SSam Ravnborg	  MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing
1778506f1d07SSam Ravnborg	  write-combining. All of these processors are supported by this code
1779506f1d07SSam Ravnborg	  and it makes sense to say Y here if you have one of them.
1780506f1d07SSam Ravnborg
1781506f1d07SSam Ravnborg	  Saying Y here also fixes a problem with buggy SMP BIOSes which only
1782506f1d07SSam Ravnborg	  set the MTRRs for the boot CPU and not for the secondary CPUs. This
1783506f1d07SSam Ravnborg	  can lead to all sorts of problems, so it's good to say Y here.
1784506f1d07SSam Ravnborg
1785506f1d07SSam Ravnborg	  You can safely say Y even if your machine doesn't have MTRRs, you'll
1786506f1d07SSam Ravnborg	  just add about 9 KB to your kernel.
1787506f1d07SSam Ravnborg
1788cb1aaebeSMauro Carvalho Chehab	  See <file:Documentation/x86/mtrr.rst> for more information.
1789506f1d07SSam Ravnborg
179095ffa243SYinghai Luconfig MTRR_SANITIZER
17912ffb3501SYinghai Lu	def_bool y
179295ffa243SYinghai Lu	prompt "MTRR cleanup support"
179395ffa243SYinghai Lu	depends on MTRR
1794a7f7f624SMasahiro Yamada	help
1795aba3728cSThomas Gleixner	  Convert MTRR layout from continuous to discrete, so X drivers can
1796aba3728cSThomas Gleixner	  add writeback entries.
179795ffa243SYinghai Lu
1798aba3728cSThomas Gleixner	  Can be disabled with disable_mtrr_cleanup on the kernel command line.
1799692105b8SMatt LaPlante	  The largest mtrr entry size for a continuous block can be set with
1800aba3728cSThomas Gleixner	  mtrr_chunk_size.
180195ffa243SYinghai Lu
18022ffb3501SYinghai Lu	  If unsure, say Y.
180395ffa243SYinghai Lu
180495ffa243SYinghai Luconfig MTRR_SANITIZER_ENABLE_DEFAULT
1805f5098d62SYinghai Lu	int "MTRR cleanup enable value (0-1)"
1806f5098d62SYinghai Lu	range 0 1
1807f5098d62SYinghai Lu	default "0"
180895ffa243SYinghai Lu	depends on MTRR_SANITIZER
1809a7f7f624SMasahiro Yamada	help
1810f5098d62SYinghai Lu	  Enable mtrr cleanup default value
181195ffa243SYinghai Lu
181212031a62SYinghai Luconfig MTRR_SANITIZER_SPARE_REG_NR_DEFAULT
181312031a62SYinghai Lu	int "MTRR cleanup spare reg num (0-7)"
181412031a62SYinghai Lu	range 0 7
181512031a62SYinghai Lu	default "1"
181612031a62SYinghai Lu	depends on MTRR_SANITIZER
1817a7f7f624SMasahiro Yamada	help
181812031a62SYinghai Lu	  mtrr cleanup spare entries default, it can be changed via
1819aba3728cSThomas Gleixner	  mtrr_spare_reg_nr=N on the kernel command line.
182012031a62SYinghai Lu
18212e5d9c85Svenkatesh.pallipadi@intel.comconfig X86_PAT
18226fc108a0SJan Beulich	def_bool y
18236a108a14SDavid Rientjes	prompt "x86 PAT support" if EXPERT
18242a8a2719SIngo Molnar	depends on MTRR
1825a7f7f624SMasahiro Yamada	help
18262e5d9c85Svenkatesh.pallipadi@intel.com	  Use PAT attributes to setup page level cache control.
1827042b78e4SVenki Pallipadi
18282e5d9c85Svenkatesh.pallipadi@intel.com	  PATs are the modern equivalents of MTRRs and are much more
18292e5d9c85Svenkatesh.pallipadi@intel.com	  flexible than MTRRs.
18302e5d9c85Svenkatesh.pallipadi@intel.com
18312e5d9c85Svenkatesh.pallipadi@intel.com	  Say N here if you see bootup problems (boot crash, boot hang,
1832042b78e4SVenki Pallipadi	  spontaneous reboots) or a non-working video driver.
18332e5d9c85Svenkatesh.pallipadi@intel.com
18342e5d9c85Svenkatesh.pallipadi@intel.com	  If unsure, say Y.
18352e5d9c85Svenkatesh.pallipadi@intel.com
183646cf98cdSVenkatesh Pallipadiconfig ARCH_USES_PG_UNCACHED
183746cf98cdSVenkatesh Pallipadi	def_bool y
183846cf98cdSVenkatesh Pallipadi	depends on X86_PAT
183946cf98cdSVenkatesh Pallipadi
1840628c6246SH. Peter Anvinconfig ARCH_RANDOM
1841628c6246SH. Peter Anvin	def_bool y
1842628c6246SH. Peter Anvin	prompt "x86 architectural random number generator" if EXPERT
1843a7f7f624SMasahiro Yamada	help
1844628c6246SH. Peter Anvin	  Enable the x86 architectural RDRAND instruction
1845628c6246SH. Peter Anvin	  (Intel Bull Mountain technology) to generate random numbers.
1846628c6246SH. Peter Anvin	  If supported, this is a high bandwidth, cryptographically
1847628c6246SH. Peter Anvin	  secure hardware random number generator.
1848628c6246SH. Peter Anvin
184951ae4a2dSH. Peter Anvinconfig X86_SMAP
185051ae4a2dSH. Peter Anvin	def_bool y
185151ae4a2dSH. Peter Anvin	prompt "Supervisor Mode Access Prevention" if EXPERT
1852a7f7f624SMasahiro Yamada	help
185351ae4a2dSH. Peter Anvin	  Supervisor Mode Access Prevention (SMAP) is a security
185451ae4a2dSH. Peter Anvin	  feature in newer Intel processors.  There is a small
185551ae4a2dSH. Peter Anvin	  performance cost if this enabled and turned on; there is
185651ae4a2dSH. Peter Anvin	  also a small increase in the kernel size if this is enabled.
185751ae4a2dSH. Peter Anvin
185851ae4a2dSH. Peter Anvin	  If unsure, say Y.
185951ae4a2dSH. Peter Anvin
1860b971880fSBabu Mogerconfig X86_UMIP
1861796ebc81SRicardo Neri	def_bool y
1862b971880fSBabu Moger	prompt "User Mode Instruction Prevention" if EXPERT
1863a7f7f624SMasahiro Yamada	help
1864b971880fSBabu Moger	  User Mode Instruction Prevention (UMIP) is a security feature in
1865b971880fSBabu Moger	  some x86 processors. If enabled, a general protection fault is
1866b971880fSBabu Moger	  issued if the SGDT, SLDT, SIDT, SMSW or STR instructions are
1867b971880fSBabu Moger	  executed in user mode. These instructions unnecessarily expose
1868b971880fSBabu Moger	  information about the hardware state.
1869796ebc81SRicardo Neri
1870796ebc81SRicardo Neri	  The vast majority of applications do not use these instructions.
1871796ebc81SRicardo Neri	  For the very few that do, software emulation is provided in
1872796ebc81SRicardo Neri	  specific cases in protected and virtual-8086 modes. Emulated
1873796ebc81SRicardo Neri	  results are dummy.
1874aa35f896SRicardo Neri
187535e97790SDave Hansenconfig X86_INTEL_MEMORY_PROTECTION_KEYS
187638f3e775SBabu Moger	prompt "Memory Protection Keys"
187735e97790SDave Hansen	def_bool y
1878284244a9SDave Hansen	# Note: only available in 64-bit mode
187938f3e775SBabu Moger	depends on X86_64 && (CPU_SUP_INTEL || CPU_SUP_AMD)
188052c8e601SIngo Molnar	select ARCH_USES_HIGH_VMA_FLAGS
188152c8e601SIngo Molnar	select ARCH_HAS_PKEYS
1882a7f7f624SMasahiro Yamada	help
1883284244a9SDave Hansen	  Memory Protection Keys provides a mechanism for enforcing
1884284244a9SDave Hansen	  page-based protections, but without requiring modification of the
1885284244a9SDave Hansen	  page tables when an application changes protection domains.
1886284244a9SDave Hansen
18871eecbcdcSMauro Carvalho Chehab	  For details, see Documentation/core-api/protection-keys.rst
1888284244a9SDave Hansen
1889284244a9SDave Hansen	  If unsure, say y.
189035e97790SDave Hansen
1891db616173SMichal Hockochoice
1892db616173SMichal Hocko	prompt "TSX enable mode"
1893db616173SMichal Hocko	depends on CPU_SUP_INTEL
1894db616173SMichal Hocko	default X86_INTEL_TSX_MODE_OFF
1895db616173SMichal Hocko	help
1896db616173SMichal Hocko	  Intel's TSX (Transactional Synchronization Extensions) feature
1897db616173SMichal Hocko	  allows to optimize locking protocols through lock elision which
1898db616173SMichal Hocko	  can lead to a noticeable performance boost.
1899db616173SMichal Hocko
1900db616173SMichal Hocko	  On the other hand it has been shown that TSX can be exploited
1901db616173SMichal Hocko	  to form side channel attacks (e.g. TAA) and chances are there
1902db616173SMichal Hocko	  will be more of those attacks discovered in the future.
1903db616173SMichal Hocko
1904db616173SMichal Hocko	  Therefore TSX is not enabled by default (aka tsx=off). An admin
1905db616173SMichal Hocko	  might override this decision by tsx=on the command line parameter.
1906db616173SMichal Hocko	  Even with TSX enabled, the kernel will attempt to enable the best
1907db616173SMichal Hocko	  possible TAA mitigation setting depending on the microcode available
1908db616173SMichal Hocko	  for the particular machine.
1909db616173SMichal Hocko
1910db616173SMichal Hocko	  This option allows to set the default tsx mode between tsx=on, =off
1911db616173SMichal Hocko	  and =auto. See Documentation/admin-guide/kernel-parameters.txt for more
1912db616173SMichal Hocko	  details.
1913db616173SMichal Hocko
1914db616173SMichal Hocko	  Say off if not sure, auto if TSX is in use but it should be used on safe
1915db616173SMichal Hocko	  platforms or on if TSX is in use and the security aspect of tsx is not
1916db616173SMichal Hocko	  relevant.
1917db616173SMichal Hocko
1918db616173SMichal Hockoconfig X86_INTEL_TSX_MODE_OFF
1919db616173SMichal Hocko	bool "off"
1920db616173SMichal Hocko	help
1921db616173SMichal Hocko	  TSX is disabled if possible - equals to tsx=off command line parameter.
1922db616173SMichal Hocko
1923db616173SMichal Hockoconfig X86_INTEL_TSX_MODE_ON
1924db616173SMichal Hocko	bool "on"
1925db616173SMichal Hocko	help
1926db616173SMichal Hocko	  TSX is always enabled on TSX capable HW - equals the tsx=on command
1927db616173SMichal Hocko	  line parameter.
1928db616173SMichal Hocko
1929db616173SMichal Hockoconfig X86_INTEL_TSX_MODE_AUTO
1930db616173SMichal Hocko	bool "auto"
1931db616173SMichal Hocko	help
1932db616173SMichal Hocko	  TSX is enabled on TSX capable HW that is believed to be safe against
1933db616173SMichal Hocko	  side channel attacks- equals the tsx=auto command line parameter.
1934db616173SMichal Hockoendchoice
1935db616173SMichal Hocko
1936e7e05452SSean Christophersonconfig X86_SGX
1937e7e05452SSean Christopherson	bool "Software Guard eXtensions (SGX)"
1938e7e05452SSean Christopherson	depends on X86_64 && CPU_SUP_INTEL
1939e7e05452SSean Christopherson	depends on CRYPTO=y
1940e7e05452SSean Christopherson	depends on CRYPTO_SHA256=y
1941e7e05452SSean Christopherson	select SRCU
1942e7e05452SSean Christopherson	select MMU_NOTIFIER
1943e7e05452SSean Christopherson	help
1944e7e05452SSean Christopherson	  Intel(R) Software Guard eXtensions (SGX) is a set of CPU instructions
1945e7e05452SSean Christopherson	  that can be used by applications to set aside private regions of code
1946e7e05452SSean Christopherson	  and data, referred to as enclaves. An enclave's private memory can
1947e7e05452SSean Christopherson	  only be accessed by code running within the enclave. Accesses from
1948e7e05452SSean Christopherson	  outside the enclave, including other enclaves, are disallowed by
1949e7e05452SSean Christopherson	  hardware.
1950e7e05452SSean Christopherson
1951e7e05452SSean Christopherson	  If unsure, say N.
1952e7e05452SSean Christopherson
1953506f1d07SSam Ravnborgconfig EFI
19549ba16087SJan Beulich	bool "EFI runtime service support"
19555b83683fSHuang, Ying	depends on ACPI
1956f6ce5002SSergey Vlasov	select UCS2_STRING
1957022ee6c5SArd Biesheuvel	select EFI_RUNTIME_WRAPPERS
1958a7f7f624SMasahiro Yamada	help
19598b2cb7a8SHuang, Ying	  This enables the kernel to use EFI runtime services that are
1960506f1d07SSam Ravnborg	  available (such as the EFI variable services).
1961506f1d07SSam Ravnborg
19628b2cb7a8SHuang, Ying	  This option is only useful on systems that have EFI firmware.
19638b2cb7a8SHuang, Ying	  In addition, you should use the latest ELILO loader available
19648b2cb7a8SHuang, Ying	  at <http://elilo.sourceforge.net> in order to take advantage
19658b2cb7a8SHuang, Ying	  of EFI runtime services. However, even with this option, the
19668b2cb7a8SHuang, Ying	  resultant kernel should continue to boot on existing non-EFI
19678b2cb7a8SHuang, Ying	  platforms.
1968506f1d07SSam Ravnborg
1969291f3632SMatt Flemingconfig EFI_STUB
1970291f3632SMatt Fleming	bool "EFI stub support"
1971b16d8c23SMatt Fleming	depends on EFI && !X86_USE_3DNOW
19728f24f8c2SArd Biesheuvel	depends on $(cc-option,-mabi=ms) || X86_32
19737b2a583aSMatt Fleming	select RELOCATABLE
1974a7f7f624SMasahiro Yamada	help
1975291f3632SMatt Fleming	  This kernel feature allows a bzImage to be loaded directly
1976291f3632SMatt Fleming	  by EFI firmware without the use of a bootloader.
1977291f3632SMatt Fleming
19784f4cfa6cSMauro Carvalho Chehab	  See Documentation/admin-guide/efi-stub.rst for more information.
19790c759662SMatt Fleming
19807d453eeeSMatt Flemingconfig EFI_MIXED
19817d453eeeSMatt Fleming	bool "EFI mixed-mode support"
19827d453eeeSMatt Fleming	depends on EFI_STUB && X86_64
1983a7f7f624SMasahiro Yamada	help
19847d453eeeSMatt Fleming	   Enabling this feature allows a 64-bit kernel to be booted
19857d453eeeSMatt Fleming	   on a 32-bit firmware, provided that your CPU supports 64-bit
19867d453eeeSMatt Fleming	   mode.
19877d453eeeSMatt Fleming
19887d453eeeSMatt Fleming	   Note that it is not possible to boot a mixed-mode enabled
19897d453eeeSMatt Fleming	   kernel via the EFI boot stub - a bootloader that supports
19907d453eeeSMatt Fleming	   the EFI handover protocol must be used.
19917d453eeeSMatt Fleming
19927d453eeeSMatt Fleming	   If unsure, say N.
19937d453eeeSMatt Fleming
19948636a1f9SMasahiro Yamadasource "kernel/Kconfig.hz"
1995506f1d07SSam Ravnborg
1996506f1d07SSam Ravnborgconfig KEXEC
1997506f1d07SSam Ravnborg	bool "kexec system call"
19982965faa5SDave Young	select KEXEC_CORE
1999a7f7f624SMasahiro Yamada	help
2000506f1d07SSam Ravnborg	  kexec is a system call that implements the ability to shutdown your
2001506f1d07SSam Ravnborg	  current kernel, and to start another kernel.  It is like a reboot
2002506f1d07SSam Ravnborg	  but it is independent of the system firmware.   And like a reboot
2003506f1d07SSam Ravnborg	  you can start any kernel with it, not just Linux.
2004506f1d07SSam Ravnborg
2005506f1d07SSam Ravnborg	  The name comes from the similarity to the exec system call.
2006506f1d07SSam Ravnborg
2007506f1d07SSam Ravnborg	  It is an ongoing process to be certain the hardware in a machine
2008506f1d07SSam Ravnborg	  is properly shutdown, so do not be surprised if this code does not
2009bf220695SGeert Uytterhoeven	  initially work for you.  As of this writing the exact hardware
2010bf220695SGeert Uytterhoeven	  interface is strongly in flux, so no good recommendation can be
2011bf220695SGeert Uytterhoeven	  made.
2012506f1d07SSam Ravnborg
201374ca317cSVivek Goyalconfig KEXEC_FILE
201474ca317cSVivek Goyal	bool "kexec file based system call"
20152965faa5SDave Young	select KEXEC_CORE
201674ca317cSVivek Goyal	select BUILD_BIN2C
201774ca317cSVivek Goyal	depends on X86_64
201874ca317cSVivek Goyal	depends on CRYPTO=y
201974ca317cSVivek Goyal	depends on CRYPTO_SHA256=y
2020a7f7f624SMasahiro Yamada	help
202174ca317cSVivek Goyal	  This is new version of kexec system call. This system call is
202274ca317cSVivek Goyal	  file based and takes file descriptors as system call argument
202374ca317cSVivek Goyal	  for kernel and initramfs as opposed to list of segments as
202474ca317cSVivek Goyal	  accepted by previous system call.
202574ca317cSVivek Goyal
2026b799a09fSAKASHI Takahiroconfig ARCH_HAS_KEXEC_PURGATORY
2027b799a09fSAKASHI Takahiro	def_bool KEXEC_FILE
2028b799a09fSAKASHI Takahiro
202999d5cadfSJiri Bohacconfig KEXEC_SIG
20308e7d8381SVivek Goyal	bool "Verify kernel signature during kexec_file_load() syscall"
203174ca317cSVivek Goyal	depends on KEXEC_FILE
2032a7f7f624SMasahiro Yamada	help
203399d5cadfSJiri Bohac
203499d5cadfSJiri Bohac	  This option makes the kexec_file_load() syscall check for a valid
203599d5cadfSJiri Bohac	  signature of the kernel image.  The image can still be loaded without
203699d5cadfSJiri Bohac	  a valid signature unless you also enable KEXEC_SIG_FORCE, though if
203799d5cadfSJiri Bohac	  there's a signature that we can check, then it must be valid.
203899d5cadfSJiri Bohac
203999d5cadfSJiri Bohac	  In addition to this option, you need to enable signature
204099d5cadfSJiri Bohac	  verification for the corresponding kernel image type being
204199d5cadfSJiri Bohac	  loaded in order for this to work.
204299d5cadfSJiri Bohac
204399d5cadfSJiri Bohacconfig KEXEC_SIG_FORCE
204499d5cadfSJiri Bohac	bool "Require a valid signature in kexec_file_load() syscall"
204599d5cadfSJiri Bohac	depends on KEXEC_SIG
2046a7f7f624SMasahiro Yamada	help
20478e7d8381SVivek Goyal	  This option makes kernel signature verification mandatory for
2048d8eb8940SBorislav Petkov	  the kexec_file_load() syscall.
20498e7d8381SVivek Goyal
20508e7d8381SVivek Goyalconfig KEXEC_BZIMAGE_VERIFY_SIG
20518e7d8381SVivek Goyal	bool "Enable bzImage signature verification support"
205299d5cadfSJiri Bohac	depends on KEXEC_SIG
20538e7d8381SVivek Goyal	depends on SIGNED_PE_FILE_VERIFICATION
20548e7d8381SVivek Goyal	select SYSTEM_TRUSTED_KEYRING
2055a7f7f624SMasahiro Yamada	help
20568e7d8381SVivek Goyal	  Enable bzImage signature verification support.
20578e7d8381SVivek Goyal
2058506f1d07SSam Ravnborgconfig CRASH_DUMP
205904b69447SPavel Machek	bool "kernel crash dumps"
2060506f1d07SSam Ravnborg	depends on X86_64 || (X86_32 && HIGHMEM)
2061a7f7f624SMasahiro Yamada	help
2062506f1d07SSam Ravnborg	  Generate crash dump after being started by kexec.
2063506f1d07SSam Ravnborg	  This should be normally only set in special crash dump kernels
2064506f1d07SSam Ravnborg	  which are loaded in the main kernel with kexec-tools into
2065506f1d07SSam Ravnborg	  a specially reserved region and then later executed after
2066506f1d07SSam Ravnborg	  a crash by kdump/kexec. The crash dump kernel must be compiled
2067506f1d07SSam Ravnborg	  to a memory address not used by the main kernel or BIOS using
2068506f1d07SSam Ravnborg	  PHYSICAL_START, or it must be built as a relocatable image
2069506f1d07SSam Ravnborg	  (CONFIG_RELOCATABLE=y).
2070330d4810SMauro Carvalho Chehab	  For more details see Documentation/admin-guide/kdump/kdump.rst
2071506f1d07SSam Ravnborg
20723ab83521SHuang Yingconfig KEXEC_JUMP
20736ea30386SKees Cook	bool "kexec jump"
2074fee7b0d8SHuang Ying	depends on KEXEC && HIBERNATION
2075a7f7f624SMasahiro Yamada	help
207689081d17SHuang Ying	  Jump between original kernel and kexeced kernel and invoke
207789081d17SHuang Ying	  code in physical address mode via KEXEC
20783ab83521SHuang Ying
2079506f1d07SSam Ravnborgconfig PHYSICAL_START
20806a108a14SDavid Rientjes	hex "Physical address where the kernel is loaded" if (EXPERT || CRASH_DUMP)
2081ceefccc9SH. Peter Anvin	default "0x1000000"
2082a7f7f624SMasahiro Yamada	help
2083506f1d07SSam Ravnborg	  This gives the physical address where the kernel is loaded.
2084506f1d07SSam Ravnborg
2085506f1d07SSam Ravnborg	  If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then
2086506f1d07SSam Ravnborg	  bzImage will decompress itself to above physical address and
2087506f1d07SSam Ravnborg	  run from there. Otherwise, bzImage will run from the address where
2088506f1d07SSam Ravnborg	  it has been loaded by the boot loader and will ignore above physical
2089506f1d07SSam Ravnborg	  address.
2090506f1d07SSam Ravnborg
2091506f1d07SSam Ravnborg	  In normal kdump cases one does not have to set/change this option
2092506f1d07SSam Ravnborg	  as now bzImage can be compiled as a completely relocatable image
2093506f1d07SSam Ravnborg	  (CONFIG_RELOCATABLE=y) and be used to load and run from a different
2094506f1d07SSam Ravnborg	  address. This option is mainly useful for the folks who don't want
2095506f1d07SSam Ravnborg	  to use a bzImage for capturing the crash dump and want to use a
2096506f1d07SSam Ravnborg	  vmlinux instead. vmlinux is not relocatable hence a kernel needs
2097506f1d07SSam Ravnborg	  to be specifically compiled to run from a specific memory area
2098506f1d07SSam Ravnborg	  (normally a reserved region) and this option comes handy.
2099506f1d07SSam Ravnborg
2100ceefccc9SH. Peter Anvin	  So if you are using bzImage for capturing the crash dump,
2101ceefccc9SH. Peter Anvin	  leave the value here unchanged to 0x1000000 and set
2102ceefccc9SH. Peter Anvin	  CONFIG_RELOCATABLE=y.  Otherwise if you plan to use vmlinux
2103ceefccc9SH. Peter Anvin	  for capturing the crash dump change this value to start of
2104ceefccc9SH. Peter Anvin	  the reserved region.  In other words, it can be set based on
2105ceefccc9SH. Peter Anvin	  the "X" value as specified in the "crashkernel=YM@XM"
2106ceefccc9SH. Peter Anvin	  command line boot parameter passed to the panic-ed
2107330d4810SMauro Carvalho Chehab	  kernel. Please take a look at Documentation/admin-guide/kdump/kdump.rst
2108ceefccc9SH. Peter Anvin	  for more details about crash dumps.
2109506f1d07SSam Ravnborg
2110506f1d07SSam Ravnborg	  Usage of bzImage for capturing the crash dump is recommended as
2111506f1d07SSam Ravnborg	  one does not have to build two kernels. Same kernel can be used
2112506f1d07SSam Ravnborg	  as production kernel and capture kernel. Above option should have
2113506f1d07SSam Ravnborg	  gone away after relocatable bzImage support is introduced. But it
2114506f1d07SSam Ravnborg	  is present because there are users out there who continue to use
2115506f1d07SSam Ravnborg	  vmlinux for dump capture. This option should go away down the
2116506f1d07SSam Ravnborg	  line.
2117506f1d07SSam Ravnborg
2118506f1d07SSam Ravnborg	  Don't change this unless you know what you are doing.
2119506f1d07SSam Ravnborg
2120506f1d07SSam Ravnborgconfig RELOCATABLE
212126717808SH. Peter Anvin	bool "Build a relocatable kernel"
212226717808SH. Peter Anvin	default y
2123a7f7f624SMasahiro Yamada	help
2124506f1d07SSam Ravnborg	  This builds a kernel image that retains relocation information
2125506f1d07SSam Ravnborg	  so it can be loaded someplace besides the default 1MB.
2126506f1d07SSam Ravnborg	  The relocations tend to make the kernel binary about 10% larger,
2127506f1d07SSam Ravnborg	  but are discarded at runtime.
2128506f1d07SSam Ravnborg
2129506f1d07SSam Ravnborg	  One use is for the kexec on panic case where the recovery kernel
2130506f1d07SSam Ravnborg	  must live at a different physical address than the primary
2131506f1d07SSam Ravnborg	  kernel.
2132506f1d07SSam Ravnborg
2133506f1d07SSam Ravnborg	  Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address
2134506f1d07SSam Ravnborg	  it has been loaded at and the compile time physical address
21358ab3820fSKees Cook	  (CONFIG_PHYSICAL_START) is used as the minimum location.
2136506f1d07SSam Ravnborg
21378ab3820fSKees Cookconfig RANDOMIZE_BASE
2138e8581e3dSBaoquan He	bool "Randomize the address of the kernel image (KASLR)"
21398ab3820fSKees Cook	depends on RELOCATABLE
21406807c846SIngo Molnar	default y
2141a7f7f624SMasahiro Yamada	help
2142e8581e3dSBaoquan He	  In support of Kernel Address Space Layout Randomization (KASLR),
2143e8581e3dSBaoquan He	  this randomizes the physical address at which the kernel image
2144e8581e3dSBaoquan He	  is decompressed and the virtual address where the kernel
2145e8581e3dSBaoquan He	  image is mapped, as a security feature that deters exploit
2146e8581e3dSBaoquan He	  attempts relying on knowledge of the location of kernel
2147e8581e3dSBaoquan He	  code internals.
2148e8581e3dSBaoquan He
2149ed9f007eSKees Cook	  On 64-bit, the kernel physical and virtual addresses are
2150ed9f007eSKees Cook	  randomized separately. The physical address will be anywhere
2151ed9f007eSKees Cook	  between 16MB and the top of physical memory (up to 64TB). The
2152ed9f007eSKees Cook	  virtual address will be randomized from 16MB up to 1GB (9 bits
2153ed9f007eSKees Cook	  of entropy). Note that this also reduces the memory space
2154ed9f007eSKees Cook	  available to kernel modules from 1.5GB to 1GB.
2155ed9f007eSKees Cook
2156ed9f007eSKees Cook	  On 32-bit, the kernel physical and virtual addresses are
2157ed9f007eSKees Cook	  randomized together. They will be randomized from 16MB up to
2158ed9f007eSKees Cook	  512MB (8 bits of entropy).
21598ab3820fSKees Cook
2160a653f356SKees Cook	  Entropy is generated using the RDRAND instruction if it is
2161e8581e3dSBaoquan He	  supported. If RDTSC is supported, its value is mixed into
2162e8581e3dSBaoquan He	  the entropy pool as well. If neither RDRAND nor RDTSC are
2163ed9f007eSKees Cook	  supported, then entropy is read from the i8254 timer. The
2164ed9f007eSKees Cook	  usable entropy is limited by the kernel being built using
2165ed9f007eSKees Cook	  2GB addressing, and that PHYSICAL_ALIGN must be at a
2166ed9f007eSKees Cook	  minimum of 2MB. As a result, only 10 bits of entropy are
2167ed9f007eSKees Cook	  theoretically possible, but the implementations are further
2168ed9f007eSKees Cook	  limited due to memory layouts.
2169e8581e3dSBaoquan He
21706807c846SIngo Molnar	  If unsure, say Y.
2171da2b6fb9SKees Cook
21728ab3820fSKees Cook# Relocation on x86 needs some additional build support
2173845adf72SH. Peter Anvinconfig X86_NEED_RELOCS
2174845adf72SH. Peter Anvin	def_bool y
21758ab3820fSKees Cook	depends on RANDOMIZE_BASE || (X86_32 && RELOCATABLE)
2176845adf72SH. Peter Anvin
2177506f1d07SSam Ravnborgconfig PHYSICAL_ALIGN
2178a0215061SKees Cook	hex "Alignment value to which kernel should be aligned"
21798ab3820fSKees Cook	default "0x200000"
2180a0215061SKees Cook	range 0x2000 0x1000000 if X86_32
2181a0215061SKees Cook	range 0x200000 0x1000000 if X86_64
2182a7f7f624SMasahiro Yamada	help
2183506f1d07SSam Ravnborg	  This value puts the alignment restrictions on physical address
2184506f1d07SSam Ravnborg	  where kernel is loaded and run from. Kernel is compiled for an
2185506f1d07SSam Ravnborg	  address which meets above alignment restriction.
2186506f1d07SSam Ravnborg
2187506f1d07SSam Ravnborg	  If bootloader loads the kernel at a non-aligned address and
2188506f1d07SSam Ravnborg	  CONFIG_RELOCATABLE is set, kernel will move itself to nearest
2189506f1d07SSam Ravnborg	  address aligned to above value and run from there.
2190506f1d07SSam Ravnborg
2191506f1d07SSam Ravnborg	  If bootloader loads the kernel at a non-aligned address and
2192506f1d07SSam Ravnborg	  CONFIG_RELOCATABLE is not set, kernel will ignore the run time
2193506f1d07SSam Ravnborg	  load address and decompress itself to the address it has been
2194506f1d07SSam Ravnborg	  compiled for and run from there. The address for which kernel is
2195506f1d07SSam Ravnborg	  compiled already meets above alignment restrictions. Hence the
2196506f1d07SSam Ravnborg	  end result is that kernel runs from a physical address meeting
2197506f1d07SSam Ravnborg	  above alignment restrictions.
2198506f1d07SSam Ravnborg
2199a0215061SKees Cook	  On 32-bit this value must be a multiple of 0x2000. On 64-bit
2200a0215061SKees Cook	  this value must be a multiple of 0x200000.
2201a0215061SKees Cook
2202506f1d07SSam Ravnborg	  Don't change this unless you know what you are doing.
2203506f1d07SSam Ravnborg
2204eedb92abSKirill A. Shutemovconfig DYNAMIC_MEMORY_LAYOUT
2205eedb92abSKirill A. Shutemov	bool
2206a7f7f624SMasahiro Yamada	help
2207eedb92abSKirill A. Shutemov	  This option makes base addresses of vmalloc and vmemmap as well as
2208eedb92abSKirill A. Shutemov	  __PAGE_OFFSET movable during boot.
2209eedb92abSKirill A. Shutemov
22100483e1faSThomas Garnierconfig RANDOMIZE_MEMORY
22110483e1faSThomas Garnier	bool "Randomize the kernel memory sections"
22120483e1faSThomas Garnier	depends on X86_64
22130483e1faSThomas Garnier	depends on RANDOMIZE_BASE
2214eedb92abSKirill A. Shutemov	select DYNAMIC_MEMORY_LAYOUT
22150483e1faSThomas Garnier	default RANDOMIZE_BASE
2216a7f7f624SMasahiro Yamada	help
22170483e1faSThomas Garnier	   Randomizes the base virtual address of kernel memory sections
22180483e1faSThomas Garnier	   (physical memory mapping, vmalloc & vmemmap). This security feature
22190483e1faSThomas Garnier	   makes exploits relying on predictable memory locations less reliable.
22200483e1faSThomas Garnier
22210483e1faSThomas Garnier	   The order of allocations remains unchanged. Entropy is generated in
22220483e1faSThomas Garnier	   the same way as RANDOMIZE_BASE. Current implementation in the optimal
22230483e1faSThomas Garnier	   configuration have in average 30,000 different possible virtual
22240483e1faSThomas Garnier	   addresses for each memory section.
22250483e1faSThomas Garnier
22266807c846SIngo Molnar	   If unsure, say Y.
22270483e1faSThomas Garnier
222890397a41SThomas Garnierconfig RANDOMIZE_MEMORY_PHYSICAL_PADDING
222990397a41SThomas Garnier	hex "Physical memory mapping padding" if EXPERT
223090397a41SThomas Garnier	depends on RANDOMIZE_MEMORY
223190397a41SThomas Garnier	default "0xa" if MEMORY_HOTPLUG
223290397a41SThomas Garnier	default "0x0"
223390397a41SThomas Garnier	range 0x1 0x40 if MEMORY_HOTPLUG
223490397a41SThomas Garnier	range 0x0 0x40
2235a7f7f624SMasahiro Yamada	help
223690397a41SThomas Garnier	   Define the padding in terabytes added to the existing physical
223790397a41SThomas Garnier	   memory size during kernel memory randomization. It is useful
223890397a41SThomas Garnier	   for memory hotplug support but reduces the entropy available for
223990397a41SThomas Garnier	   address randomization.
224090397a41SThomas Garnier
224190397a41SThomas Garnier	   If unsure, leave at the default value.
224290397a41SThomas Garnier
2243506f1d07SSam Ravnborgconfig HOTPLUG_CPU
2244bebd024eSThomas Gleixner	def_bool y
224540b31360SStephen Rothwell	depends on SMP
2246506f1d07SSam Ravnborg
224780aa1dffSFenghua Yuconfig BOOTPARAM_HOTPLUG_CPU0
224880aa1dffSFenghua Yu	bool "Set default setting of cpu0_hotpluggable"
22492c922cd0SKees Cook	depends on HOTPLUG_CPU
2250a7f7f624SMasahiro Yamada	help
225180aa1dffSFenghua Yu	  Set whether default state of cpu0_hotpluggable is on or off.
225280aa1dffSFenghua Yu
225380aa1dffSFenghua Yu	  Say Y here to enable CPU0 hotplug by default. If this switch
225480aa1dffSFenghua Yu	  is turned on, there is no need to give cpu0_hotplug kernel
225580aa1dffSFenghua Yu	  parameter and the CPU0 hotplug feature is enabled by default.
225680aa1dffSFenghua Yu
225780aa1dffSFenghua Yu	  Please note: there are two known CPU0 dependencies if you want
225880aa1dffSFenghua Yu	  to enable the CPU0 hotplug feature either by this switch or by
225980aa1dffSFenghua Yu	  cpu0_hotplug kernel parameter.
226080aa1dffSFenghua Yu
226180aa1dffSFenghua Yu	  First, resume from hibernate or suspend always starts from CPU0.
226280aa1dffSFenghua Yu	  So hibernate and suspend are prevented if CPU0 is offline.
226380aa1dffSFenghua Yu
226480aa1dffSFenghua Yu	  Second dependency is PIC interrupts always go to CPU0. CPU0 can not
226580aa1dffSFenghua Yu	  offline if any interrupt can not migrate out of CPU0. There may
226680aa1dffSFenghua Yu	  be other CPU0 dependencies.
226780aa1dffSFenghua Yu
226880aa1dffSFenghua Yu	  Please make sure the dependencies are under your control before
226980aa1dffSFenghua Yu	  you enable this feature.
227080aa1dffSFenghua Yu
227180aa1dffSFenghua Yu	  Say N if you don't want to enable CPU0 hotplug feature by default.
227280aa1dffSFenghua Yu	  You still can enable the CPU0 hotplug feature at boot by kernel
227380aa1dffSFenghua Yu	  parameter cpu0_hotplug.
227480aa1dffSFenghua Yu
2275a71c8bc5SFenghua Yuconfig DEBUG_HOTPLUG_CPU0
2276a71c8bc5SFenghua Yu	def_bool n
2277a71c8bc5SFenghua Yu	prompt "Debug CPU0 hotplug"
22782c922cd0SKees Cook	depends on HOTPLUG_CPU
2279a7f7f624SMasahiro Yamada	help
2280a71c8bc5SFenghua Yu	  Enabling this option offlines CPU0 (if CPU0 can be offlined) as
2281a71c8bc5SFenghua Yu	  soon as possible and boots up userspace with CPU0 offlined. User
2282a71c8bc5SFenghua Yu	  can online CPU0 back after boot time.
2283a71c8bc5SFenghua Yu
2284a71c8bc5SFenghua Yu	  To debug CPU0 hotplug, you need to enable CPU0 offline/online
2285a71c8bc5SFenghua Yu	  feature by either turning on CONFIG_BOOTPARAM_HOTPLUG_CPU0 during
2286a71c8bc5SFenghua Yu	  compilation or giving cpu0_hotplug kernel parameter at boot.
2287a71c8bc5SFenghua Yu
2288a71c8bc5SFenghua Yu	  If unsure, say N.
2289a71c8bc5SFenghua Yu
2290506f1d07SSam Ravnborgconfig COMPAT_VDSO
2291b0b49f26SAndy Lutomirski	def_bool n
2292b0b49f26SAndy Lutomirski	prompt "Disable the 32-bit vDSO (needed for glibc 2.3.3)"
2293953fee1dSIngo Molnar	depends on COMPAT_32
2294a7f7f624SMasahiro Yamada	help
2295b0b49f26SAndy Lutomirski	  Certain buggy versions of glibc will crash if they are
2296b0b49f26SAndy Lutomirski	  presented with a 32-bit vDSO that is not mapped at the address
2297b0b49f26SAndy Lutomirski	  indicated in its segment table.
2298e84446deSRandy Dunlap
2299b0b49f26SAndy Lutomirski	  The bug was introduced by f866314b89d56845f55e6f365e18b31ec978ec3a
2300b0b49f26SAndy Lutomirski	  and fixed by 3b3ddb4f7db98ec9e912ccdf54d35df4aa30e04a and
2301b0b49f26SAndy Lutomirski	  49ad572a70b8aeb91e57483a11dd1b77e31c4468.  Glibc 2.3.3 is
2302b0b49f26SAndy Lutomirski	  the only released version with the bug, but OpenSUSE 9
2303b0b49f26SAndy Lutomirski	  contains a buggy "glibc 2.3.2".
2304506f1d07SSam Ravnborg
2305b0b49f26SAndy Lutomirski	  The symptom of the bug is that everything crashes on startup, saying:
2306b0b49f26SAndy Lutomirski	  dl_main: Assertion `(void *) ph->p_vaddr == _rtld_local._dl_sysinfo_dso' failed!
2307b0b49f26SAndy Lutomirski
2308b0b49f26SAndy Lutomirski	  Saying Y here changes the default value of the vdso32 boot
2309b0b49f26SAndy Lutomirski	  option from 1 to 0, which turns off the 32-bit vDSO entirely.
2310b0b49f26SAndy Lutomirski	  This works around the glibc bug but hurts performance.
2311b0b49f26SAndy Lutomirski
2312b0b49f26SAndy Lutomirski	  If unsure, say N: if you are compiling your own kernel, you
2313b0b49f26SAndy Lutomirski	  are unlikely to be using a buggy version of glibc.
2314506f1d07SSam Ravnborg
23153dc33bd3SKees Cookchoice
23163dc33bd3SKees Cook	prompt "vsyscall table for legacy applications"
23173dc33bd3SKees Cook	depends on X86_64
2318625b7b7fSAndy Lutomirski	default LEGACY_VSYSCALL_XONLY
23193dc33bd3SKees Cook	help
23203dc33bd3SKees Cook	  Legacy user code that does not know how to find the vDSO expects
23213dc33bd3SKees Cook	  to be able to issue three syscalls by calling fixed addresses in
23223dc33bd3SKees Cook	  kernel space. Since this location is not randomized with ASLR,
23233dc33bd3SKees Cook	  it can be used to assist security vulnerability exploitation.
23243dc33bd3SKees Cook
23253dc33bd3SKees Cook	  This setting can be changed at boot time via the kernel command
2326bd49e16eSAndy Lutomirski	  line parameter vsyscall=[emulate|xonly|none].
23273dc33bd3SKees Cook
23283dc33bd3SKees Cook	  On a system with recent enough glibc (2.14 or newer) and no
23293dc33bd3SKees Cook	  static binaries, you can say None without a performance penalty
23303dc33bd3SKees Cook	  to improve security.
23313dc33bd3SKees Cook
2332bd49e16eSAndy Lutomirski	  If unsure, select "Emulate execution only".
23333dc33bd3SKees Cook
23343dc33bd3SKees Cook	config LEGACY_VSYSCALL_EMULATE
2335bd49e16eSAndy Lutomirski		bool "Full emulation"
23363dc33bd3SKees Cook		help
2337bd49e16eSAndy Lutomirski		  The kernel traps and emulates calls into the fixed vsyscall
2338bd49e16eSAndy Lutomirski		  address mapping. This makes the mapping non-executable, but
2339bd49e16eSAndy Lutomirski		  it still contains readable known contents, which could be
2340bd49e16eSAndy Lutomirski		  used in certain rare security vulnerability exploits. This
2341bd49e16eSAndy Lutomirski		  configuration is recommended when using legacy userspace
2342bd49e16eSAndy Lutomirski		  that still uses vsyscalls along with legacy binary
2343bd49e16eSAndy Lutomirski		  instrumentation tools that require code to be readable.
2344bd49e16eSAndy Lutomirski
2345bd49e16eSAndy Lutomirski		  An example of this type of legacy userspace is running
2346bd49e16eSAndy Lutomirski		  Pin on an old binary that still uses vsyscalls.
2347bd49e16eSAndy Lutomirski
2348bd49e16eSAndy Lutomirski	config LEGACY_VSYSCALL_XONLY
2349bd49e16eSAndy Lutomirski		bool "Emulate execution only"
2350bd49e16eSAndy Lutomirski		help
2351bd49e16eSAndy Lutomirski		  The kernel traps and emulates calls into the fixed vsyscall
2352bd49e16eSAndy Lutomirski		  address mapping and does not allow reads.  This
2353bd49e16eSAndy Lutomirski		  configuration is recommended when userspace might use the
2354bd49e16eSAndy Lutomirski		  legacy vsyscall area but support for legacy binary
2355bd49e16eSAndy Lutomirski		  instrumentation of legacy code is not needed.  It mitigates
2356bd49e16eSAndy Lutomirski		  certain uses of the vsyscall area as an ASLR-bypassing
2357bd49e16eSAndy Lutomirski		  buffer.
23583dc33bd3SKees Cook
23593dc33bd3SKees Cook	config LEGACY_VSYSCALL_NONE
23603dc33bd3SKees Cook		bool "None"
23613dc33bd3SKees Cook		help
23623dc33bd3SKees Cook		  There will be no vsyscall mapping at all. This will
23633dc33bd3SKees Cook		  eliminate any risk of ASLR bypass due to the vsyscall
23643dc33bd3SKees Cook		  fixed address mapping. Attempts to use the vsyscalls
23653dc33bd3SKees Cook		  will be reported to dmesg, so that either old or
23663dc33bd3SKees Cook		  malicious userspace programs can be identified.
23673dc33bd3SKees Cook
23683dc33bd3SKees Cookendchoice
23693dc33bd3SKees Cook
2370516cbf37STim Birdconfig CMDLINE_BOOL
2371516cbf37STim Bird	bool "Built-in kernel command line"
2372a7f7f624SMasahiro Yamada	help
2373516cbf37STim Bird	  Allow for specifying boot arguments to the kernel at
2374516cbf37STim Bird	  build time.  On some systems (e.g. embedded ones), it is
2375516cbf37STim Bird	  necessary or convenient to provide some or all of the
2376516cbf37STim Bird	  kernel boot arguments with the kernel itself (that is,
2377516cbf37STim Bird	  to not rely on the boot loader to provide them.)
2378516cbf37STim Bird
2379516cbf37STim Bird	  To compile command line arguments into the kernel,
2380516cbf37STim Bird	  set this option to 'Y', then fill in the
238169711ca1SSébastien Hinderer	  boot arguments in CONFIG_CMDLINE.
2382516cbf37STim Bird
2383516cbf37STim Bird	  Systems with fully functional boot loaders (i.e. non-embedded)
2384516cbf37STim Bird	  should leave this option set to 'N'.
2385516cbf37STim Bird
2386516cbf37STim Birdconfig CMDLINE
2387516cbf37STim Bird	string "Built-in kernel command string"
2388516cbf37STim Bird	depends on CMDLINE_BOOL
2389516cbf37STim Bird	default ""
2390a7f7f624SMasahiro Yamada	help
2391516cbf37STim Bird	  Enter arguments here that should be compiled into the kernel
2392516cbf37STim Bird	  image and used at boot time.  If the boot loader provides a
2393516cbf37STim Bird	  command line at boot time, it is appended to this string to
2394516cbf37STim Bird	  form the full kernel command line, when the system boots.
2395516cbf37STim Bird
2396516cbf37STim Bird	  However, you can use the CONFIG_CMDLINE_OVERRIDE option to
2397516cbf37STim Bird	  change this behavior.
2398516cbf37STim Bird
2399516cbf37STim Bird	  In most cases, the command line (whether built-in or provided
2400516cbf37STim Bird	  by the boot loader) should specify the device for the root
2401516cbf37STim Bird	  file system.
2402516cbf37STim Bird
2403516cbf37STim Birdconfig CMDLINE_OVERRIDE
2404516cbf37STim Bird	bool "Built-in command line overrides boot loader arguments"
2405645e6466SAnders Roxell	depends on CMDLINE_BOOL && CMDLINE != ""
2406a7f7f624SMasahiro Yamada	help
2407516cbf37STim Bird	  Set this option to 'Y' to have the kernel ignore the boot loader
2408516cbf37STim Bird	  command line, and use ONLY the built-in command line.
2409516cbf37STim Bird
2410516cbf37STim Bird	  This is used to work around broken boot loaders.  This should
2411516cbf37STim Bird	  be set to 'N' under normal conditions.
2412516cbf37STim Bird
2413a5b9e5a2SAndy Lutomirskiconfig MODIFY_LDT_SYSCALL
2414a5b9e5a2SAndy Lutomirski	bool "Enable the LDT (local descriptor table)" if EXPERT
2415a5b9e5a2SAndy Lutomirski	default y
2416a7f7f624SMasahiro Yamada	help
2417a5b9e5a2SAndy Lutomirski	  Linux can allow user programs to install a per-process x86
2418a5b9e5a2SAndy Lutomirski	  Local Descriptor Table (LDT) using the modify_ldt(2) system
2419a5b9e5a2SAndy Lutomirski	  call.  This is required to run 16-bit or segmented code such as
2420a5b9e5a2SAndy Lutomirski	  DOSEMU or some Wine programs.  It is also used by some very old
2421a5b9e5a2SAndy Lutomirski	  threading libraries.
2422a5b9e5a2SAndy Lutomirski
2423a5b9e5a2SAndy Lutomirski	  Enabling this feature adds a small amount of overhead to
2424a5b9e5a2SAndy Lutomirski	  context switches and increases the low-level kernel attack
2425a5b9e5a2SAndy Lutomirski	  surface.  Disabling it removes the modify_ldt(2) system call.
2426a5b9e5a2SAndy Lutomirski
2427a5b9e5a2SAndy Lutomirski	  Saying 'N' here may make sense for embedded or server kernels.
2428a5b9e5a2SAndy Lutomirski
2429b700e7f0SSeth Jenningssource "kernel/livepatch/Kconfig"
2430b700e7f0SSeth Jennings
2431506f1d07SSam Ravnborgendmenu
2432506f1d07SSam Ravnborg
24333072e413SMichal Hockoconfig ARCH_HAS_ADD_PAGES
24343072e413SMichal Hocko	def_bool y
24353072e413SMichal Hocko	depends on X86_64 && ARCH_ENABLE_MEMORY_HOTPLUG
24363072e413SMichal Hocko
2437506f1d07SSam Ravnborgconfig ARCH_ENABLE_MEMORY_HOTPLUG
2438506f1d07SSam Ravnborg	def_bool y
2439506f1d07SSam Ravnborg	depends on X86_64 || (X86_32 && HIGHMEM)
2440506f1d07SSam Ravnborg
244135551053SGary Hadeconfig ARCH_ENABLE_MEMORY_HOTREMOVE
244235551053SGary Hade	def_bool y
244335551053SGary Hade	depends on MEMORY_HOTPLUG
244435551053SGary Hade
2445e534c7c5SLee Schermerhornconfig USE_PERCPU_NUMA_NODE_ID
2446645a7919STejun Heo	def_bool y
2447e534c7c5SLee Schermerhorn	depends on NUMA
2448e534c7c5SLee Schermerhorn
24499491846fSKirill A. Shutemovconfig ARCH_ENABLE_SPLIT_PMD_PTLOCK
24509491846fSKirill A. Shutemov	def_bool y
24519491846fSKirill A. Shutemov	depends on X86_64 || X86_PAE
24529491846fSKirill A. Shutemov
2453c177c81eSNaoya Horiguchiconfig ARCH_ENABLE_HUGEPAGE_MIGRATION
2454c177c81eSNaoya Horiguchi	def_bool y
2455c177c81eSNaoya Horiguchi	depends on X86_64 && HUGETLB_PAGE && MIGRATION
2456c177c81eSNaoya Horiguchi
24579c670ea3SNaoya Horiguchiconfig ARCH_ENABLE_THP_MIGRATION
24589c670ea3SNaoya Horiguchi	def_bool y
24599c670ea3SNaoya Horiguchi	depends on X86_64 && TRANSPARENT_HUGEPAGE
24609c670ea3SNaoya Horiguchi
2461da85f865SBjorn Helgaasmenu "Power management and ACPI options"
2462e279b6c1SSam Ravnborg
2463e279b6c1SSam Ravnborgconfig ARCH_HIBERNATION_HEADER
24643c2362e6SHarvey Harrison	def_bool y
246544556530SZhimin Gu	depends on HIBERNATION
2466e279b6c1SSam Ravnborg
2467e279b6c1SSam Ravnborgsource "kernel/power/Kconfig"
2468e279b6c1SSam Ravnborg
2469e279b6c1SSam Ravnborgsource "drivers/acpi/Kconfig"
2470e279b6c1SSam Ravnborg
2471efafc8b2SFeng Tangsource "drivers/sfi/Kconfig"
2472efafc8b2SFeng Tang
2473a6b68076SAndi Kleenconfig X86_APM_BOOT
24746fc108a0SJan Beulich	def_bool y
2475282e5aabSPaul Bolle	depends on APM
2476a6b68076SAndi Kleen
2477e279b6c1SSam Ravnborgmenuconfig APM
2478e279b6c1SSam Ravnborg	tristate "APM (Advanced Power Management) BIOS support"
2479efefa6f6SIngo Molnar	depends on X86_32 && PM_SLEEP
2480a7f7f624SMasahiro Yamada	help
2481e279b6c1SSam Ravnborg	  APM is a BIOS specification for saving power using several different
2482e279b6c1SSam Ravnborg	  techniques. This is mostly useful for battery powered laptops with
2483e279b6c1SSam Ravnborg	  APM compliant BIOSes. If you say Y here, the system time will be
2484e279b6c1SSam Ravnborg	  reset after a RESUME operation, the /proc/apm device will provide
2485e279b6c1SSam Ravnborg	  battery status information, and user-space programs will receive
2486e279b6c1SSam Ravnborg	  notification of APM "events" (e.g. battery status change).
2487e279b6c1SSam Ravnborg
2488e279b6c1SSam Ravnborg	  If you select "Y" here, you can disable actual use of the APM
2489e279b6c1SSam Ravnborg	  BIOS by passing the "apm=off" option to the kernel at boot time.
2490e279b6c1SSam Ravnborg
2491e279b6c1SSam Ravnborg	  Note that the APM support is almost completely disabled for
2492e279b6c1SSam Ravnborg	  machines with more than one CPU.
2493e279b6c1SSam Ravnborg
2494e279b6c1SSam Ravnborg	  In order to use APM, you will need supporting software. For location
2495151f4e2bSMauro Carvalho Chehab	  and more information, read <file:Documentation/power/apm-acpi.rst>
24962dc98fd3SMichael Witten	  and the Battery Powered Linux mini-HOWTO, available from
2497e279b6c1SSam Ravnborg	  <http://www.tldp.org/docs.html#howto>.
2498e279b6c1SSam Ravnborg
2499e279b6c1SSam Ravnborg	  This driver does not spin down disk drives (see the hdparm(8)
2500e279b6c1SSam Ravnborg	  manpage ("man 8 hdparm") for that), and it doesn't turn off
2501e279b6c1SSam Ravnborg	  VESA-compliant "green" monitors.
2502e279b6c1SSam Ravnborg
2503e279b6c1SSam Ravnborg	  This driver does not support the TI 4000M TravelMate and the ACER
2504e279b6c1SSam Ravnborg	  486/DX4/75 because they don't have compliant BIOSes. Many "green"
2505e279b6c1SSam Ravnborg	  desktop machines also don't have compliant BIOSes, and this driver
2506e279b6c1SSam Ravnborg	  may cause those machines to panic during the boot phase.
2507e279b6c1SSam Ravnborg
2508e279b6c1SSam Ravnborg	  Generally, if you don't have a battery in your machine, there isn't
2509e279b6c1SSam Ravnborg	  much point in using this driver and you should say N. If you get
2510e279b6c1SSam Ravnborg	  random kernel OOPSes or reboots that don't seem to be related to
2511e279b6c1SSam Ravnborg	  anything, try disabling/enabling this option (or disabling/enabling
2512e279b6c1SSam Ravnborg	  APM in your BIOS).
2513e279b6c1SSam Ravnborg
2514e279b6c1SSam Ravnborg	  Some other things you should try when experiencing seemingly random,
2515e279b6c1SSam Ravnborg	  "weird" problems:
2516e279b6c1SSam Ravnborg
2517e279b6c1SSam Ravnborg	  1) make sure that you have enough swap space and that it is
2518e279b6c1SSam Ravnborg	  enabled.
2519e279b6c1SSam Ravnborg	  2) pass the "no-hlt" option to the kernel
2520e279b6c1SSam Ravnborg	  3) switch on floating point emulation in the kernel and pass
2521e279b6c1SSam Ravnborg	  the "no387" option to the kernel
2522e279b6c1SSam Ravnborg	  4) pass the "floppy=nodma" option to the kernel
2523e279b6c1SSam Ravnborg	  5) pass the "mem=4M" option to the kernel (thereby disabling
2524e279b6c1SSam Ravnborg	  all but the first 4 MB of RAM)
2525e279b6c1SSam Ravnborg	  6) make sure that the CPU is not over clocked.
2526e279b6c1SSam Ravnborg	  7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/>
2527e279b6c1SSam Ravnborg	  8) disable the cache from your BIOS settings
2528e279b6c1SSam Ravnborg	  9) install a fan for the video card or exchange video RAM
2529e279b6c1SSam Ravnborg	  10) install a better fan for the CPU
2530e279b6c1SSam Ravnborg	  11) exchange RAM chips
2531e279b6c1SSam Ravnborg	  12) exchange the motherboard.
2532e279b6c1SSam Ravnborg
2533e279b6c1SSam Ravnborg	  To compile this driver as a module, choose M here: the
2534e279b6c1SSam Ravnborg	  module will be called apm.
2535e279b6c1SSam Ravnborg
2536e279b6c1SSam Ravnborgif APM
2537e279b6c1SSam Ravnborg
2538e279b6c1SSam Ravnborgconfig APM_IGNORE_USER_SUSPEND
2539e279b6c1SSam Ravnborg	bool "Ignore USER SUSPEND"
2540a7f7f624SMasahiro Yamada	help
2541e279b6c1SSam Ravnborg	  This option will ignore USER SUSPEND requests. On machines with a
2542e279b6c1SSam Ravnborg	  compliant APM BIOS, you want to say N. However, on the NEC Versa M
2543e279b6c1SSam Ravnborg	  series notebooks, it is necessary to say Y because of a BIOS bug.
2544e279b6c1SSam Ravnborg
2545e279b6c1SSam Ravnborgconfig APM_DO_ENABLE
2546e279b6c1SSam Ravnborg	bool "Enable PM at boot time"
2547a7f7f624SMasahiro Yamada	help
2548e279b6c1SSam Ravnborg	  Enable APM features at boot time. From page 36 of the APM BIOS
2549e279b6c1SSam Ravnborg	  specification: "When disabled, the APM BIOS does not automatically
2550e279b6c1SSam Ravnborg	  power manage devices, enter the Standby State, enter the Suspend
2551e279b6c1SSam Ravnborg	  State, or take power saving steps in response to CPU Idle calls."
2552e279b6c1SSam Ravnborg	  This driver will make CPU Idle calls when Linux is idle (unless this
2553e279b6c1SSam Ravnborg	  feature is turned off -- see "Do CPU IDLE calls", below). This
2554e279b6c1SSam Ravnborg	  should always save battery power, but more complicated APM features
2555e279b6c1SSam Ravnborg	  will be dependent on your BIOS implementation. You may need to turn
2556e279b6c1SSam Ravnborg	  this option off if your computer hangs at boot time when using APM
2557e279b6c1SSam Ravnborg	  support, or if it beeps continuously instead of suspending. Turn
2558e279b6c1SSam Ravnborg	  this off if you have a NEC UltraLite Versa 33/C or a Toshiba
2559e279b6c1SSam Ravnborg	  T400CDT. This is off by default since most machines do fine without
2560e279b6c1SSam Ravnborg	  this feature.
2561e279b6c1SSam Ravnborg
2562e279b6c1SSam Ravnborgconfig APM_CPU_IDLE
2563dd8af076SLen Brown	depends on CPU_IDLE
2564e279b6c1SSam Ravnborg	bool "Make CPU Idle calls when idle"
2565a7f7f624SMasahiro Yamada	help
2566e279b6c1SSam Ravnborg	  Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop.
2567e279b6c1SSam Ravnborg	  On some machines, this can activate improved power savings, such as
2568e279b6c1SSam Ravnborg	  a slowed CPU clock rate, when the machine is idle. These idle calls
2569e279b6c1SSam Ravnborg	  are made after the idle loop has run for some length of time (e.g.,
2570e279b6c1SSam Ravnborg	  333 mS). On some machines, this will cause a hang at boot time or
2571e279b6c1SSam Ravnborg	  whenever the CPU becomes idle. (On machines with more than one CPU,
2572e279b6c1SSam Ravnborg	  this option does nothing.)
2573e279b6c1SSam Ravnborg
2574e279b6c1SSam Ravnborgconfig APM_DISPLAY_BLANK
2575e279b6c1SSam Ravnborg	bool "Enable console blanking using APM"
2576a7f7f624SMasahiro Yamada	help
2577e279b6c1SSam Ravnborg	  Enable console blanking using the APM. Some laptops can use this to
2578e279b6c1SSam Ravnborg	  turn off the LCD backlight when the screen blanker of the Linux
2579e279b6c1SSam Ravnborg	  virtual console blanks the screen. Note that this is only used by
2580e279b6c1SSam Ravnborg	  the virtual console screen blanker, and won't turn off the backlight
2581e279b6c1SSam Ravnborg	  when using the X Window system. This also doesn't have anything to
2582e279b6c1SSam Ravnborg	  do with your VESA-compliant power-saving monitor. Further, this
2583e279b6c1SSam Ravnborg	  option doesn't work for all laptops -- it might not turn off your
2584e279b6c1SSam Ravnborg	  backlight at all, or it might print a lot of errors to the console,
2585e279b6c1SSam Ravnborg	  especially if you are using gpm.
2586e279b6c1SSam Ravnborg
2587e279b6c1SSam Ravnborgconfig APM_ALLOW_INTS
2588e279b6c1SSam Ravnborg	bool "Allow interrupts during APM BIOS calls"
2589a7f7f624SMasahiro Yamada	help
2590e279b6c1SSam Ravnborg	  Normally we disable external interrupts while we are making calls to
2591e279b6c1SSam Ravnborg	  the APM BIOS as a measure to lessen the effects of a badly behaving
2592e279b6c1SSam Ravnborg	  BIOS implementation.  The BIOS should reenable interrupts if it
2593e279b6c1SSam Ravnborg	  needs to.  Unfortunately, some BIOSes do not -- especially those in
2594e279b6c1SSam Ravnborg	  many of the newer IBM Thinkpads.  If you experience hangs when you
2595e279b6c1SSam Ravnborg	  suspend, try setting this to Y.  Otherwise, say N.
2596e279b6c1SSam Ravnborg
2597e279b6c1SSam Ravnborgendif # APM
2598e279b6c1SSam Ravnborg
2599bb0a56ecSDave Jonessource "drivers/cpufreq/Kconfig"
2600e279b6c1SSam Ravnborg
2601e279b6c1SSam Ravnborgsource "drivers/cpuidle/Kconfig"
2602e279b6c1SSam Ravnborg
260327471fdbSAndy Henroidsource "drivers/idle/Kconfig"
260427471fdbSAndy Henroid
2605e279b6c1SSam Ravnborgendmenu
2606e279b6c1SSam Ravnborg
2607e279b6c1SSam Ravnborg
2608e279b6c1SSam Ravnborgmenu "Bus options (PCI etc.)"
2609e279b6c1SSam Ravnborg
2610e279b6c1SSam Ravnborgchoice
2611e279b6c1SSam Ravnborg	prompt "PCI access mode"
2612efefa6f6SIngo Molnar	depends on X86_32 && PCI
2613e279b6c1SSam Ravnborg	default PCI_GOANY
2614a7f7f624SMasahiro Yamada	help
2615e279b6c1SSam Ravnborg	  On PCI systems, the BIOS can be used to detect the PCI devices and
2616e279b6c1SSam Ravnborg	  determine their configuration. However, some old PCI motherboards
2617e279b6c1SSam Ravnborg	  have BIOS bugs and may crash if this is done. Also, some embedded
2618e279b6c1SSam Ravnborg	  PCI-based systems don't have any BIOS at all. Linux can also try to
2619e279b6c1SSam Ravnborg	  detect the PCI hardware directly without using the BIOS.
2620e279b6c1SSam Ravnborg
2621e279b6c1SSam Ravnborg	  With this option, you can specify how Linux should detect the
2622e279b6c1SSam Ravnborg	  PCI devices. If you choose "BIOS", the BIOS will be used,
2623e279b6c1SSam Ravnborg	  if you choose "Direct", the BIOS won't be used, and if you
2624e279b6c1SSam Ravnborg	  choose "MMConfig", then PCI Express MMCONFIG will be used.
2625e279b6c1SSam Ravnborg	  If you choose "Any", the kernel will try MMCONFIG, then the
2626e279b6c1SSam Ravnborg	  direct access method and falls back to the BIOS if that doesn't
2627e279b6c1SSam Ravnborg	  work. If unsure, go with the default, which is "Any".
2628e279b6c1SSam Ravnborg
2629e279b6c1SSam Ravnborgconfig PCI_GOBIOS
2630e279b6c1SSam Ravnborg	bool "BIOS"
2631e279b6c1SSam Ravnborg
2632e279b6c1SSam Ravnborgconfig PCI_GOMMCONFIG
2633e279b6c1SSam Ravnborg	bool "MMConfig"
2634e279b6c1SSam Ravnborg
2635e279b6c1SSam Ravnborgconfig PCI_GODIRECT
2636e279b6c1SSam Ravnborg	bool "Direct"
2637e279b6c1SSam Ravnborg
26383ef0e1f8SAndres Salomonconfig PCI_GOOLPC
263976fb6570SDaniel Drake	bool "OLPC XO-1"
26403ef0e1f8SAndres Salomon	depends on OLPC
26413ef0e1f8SAndres Salomon
26422bdd1b03SAndres Salomonconfig PCI_GOANY
26432bdd1b03SAndres Salomon	bool "Any"
26442bdd1b03SAndres Salomon
2645e279b6c1SSam Ravnborgendchoice
2646e279b6c1SSam Ravnborg
2647e279b6c1SSam Ravnborgconfig PCI_BIOS
26483c2362e6SHarvey Harrison	def_bool y
2649efefa6f6SIngo Molnar	depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY)
2650e279b6c1SSam Ravnborg
2651e279b6c1SSam Ravnborg# x86-64 doesn't support PCI BIOS access from long mode so always go direct.
2652e279b6c1SSam Ravnborgconfig PCI_DIRECT
26533c2362e6SHarvey Harrison	def_bool y
26540aba496fSShaohua Li	depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC || PCI_GOMMCONFIG))
2655e279b6c1SSam Ravnborg
2656e279b6c1SSam Ravnborgconfig PCI_MMCONFIG
2657b45c9f36SJan Kiszka	bool "Support mmconfig PCI config space access" if X86_64
2658b45c9f36SJan Kiszka	default y
26598364e1f8SJan Kiszka	depends on PCI && (ACPI || SFI || JAILHOUSE_GUEST)
2660b45c9f36SJan Kiszka	depends on X86_64 || (PCI_GOANY || PCI_GOMMCONFIG)
2661e279b6c1SSam Ravnborg
26623ef0e1f8SAndres Salomonconfig PCI_OLPC
26632bdd1b03SAndres Salomon	def_bool y
26642bdd1b03SAndres Salomon	depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY)
26653ef0e1f8SAndres Salomon
2666b5401a96SAlex Nixonconfig PCI_XEN
2667b5401a96SAlex Nixon	def_bool y
2668b5401a96SAlex Nixon	depends on PCI && XEN
2669b5401a96SAlex Nixon	select SWIOTLB_XEN
2670b5401a96SAlex Nixon
26718364e1f8SJan Kiszkaconfig MMCONF_FAM10H
26728364e1f8SJan Kiszka	def_bool y
26738364e1f8SJan Kiszka	depends on X86_64 && PCI_MMCONFIG && ACPI
2674e279b6c1SSam Ravnborg
26753f6ea84aSIra W. Snyderconfig PCI_CNB20LE_QUIRK
26766a108a14SDavid Rientjes	bool "Read CNB20LE Host Bridge Windows" if EXPERT
26776ea30386SKees Cook	depends on PCI
26783f6ea84aSIra W. Snyder	help
26793f6ea84aSIra W. Snyder	  Read the PCI windows out of the CNB20LE host bridge. This allows
26803f6ea84aSIra W. Snyder	  PCI hotplug to work on systems with the CNB20LE chipset which do
26813f6ea84aSIra W. Snyder	  not have ACPI.
26823f6ea84aSIra W. Snyder
268364a5fed6SBjorn Helgaas	  There's no public spec for this chipset, and this functionality
268464a5fed6SBjorn Helgaas	  is known to be incomplete.
268564a5fed6SBjorn Helgaas
268664a5fed6SBjorn Helgaas	  You should say N unless you know you need this.
268764a5fed6SBjorn Helgaas
26883a495511SWilliam Breathitt Grayconfig ISA_BUS
268917a2a129SWilliam Breathitt Gray	bool "ISA bus support on modern systems" if EXPERT
26903a495511SWilliam Breathitt Gray	help
269117a2a129SWilliam Breathitt Gray	  Expose ISA bus device drivers and options available for selection and
269217a2a129SWilliam Breathitt Gray	  configuration. Enable this option if your target machine has an ISA
269317a2a129SWilliam Breathitt Gray	  bus. ISA is an older system, displaced by PCI and newer bus
269417a2a129SWilliam Breathitt Gray	  architectures -- if your target machine is modern, it probably does
269517a2a129SWilliam Breathitt Gray	  not have an ISA bus.
26963a495511SWilliam Breathitt Gray
26973a495511SWilliam Breathitt Gray	  If unsure, say N.
26983a495511SWilliam Breathitt Gray
26991c00f016SDavid Rientjes# x86_64 have no ISA slots, but can have ISA-style DMA.
2700e279b6c1SSam Ravnborgconfig ISA_DMA_API
27011c00f016SDavid Rientjes	bool "ISA-style DMA support" if (X86_64 && EXPERT)
27021c00f016SDavid Rientjes	default y
27031c00f016SDavid Rientjes	help
27041c00f016SDavid Rientjes	  Enables ISA-style DMA support for devices requiring such controllers.
27051c00f016SDavid Rientjes	  If unsure, say Y.
2706e279b6c1SSam Ravnborg
270751e68d05SLinus Torvaldsif X86_32
270851e68d05SLinus Torvalds
2709e279b6c1SSam Ravnborgconfig ISA
2710e279b6c1SSam Ravnborg	bool "ISA support"
2711a7f7f624SMasahiro Yamada	help
2712e279b6c1SSam Ravnborg	  Find out whether you have ISA slots on your motherboard.  ISA is the
2713e279b6c1SSam Ravnborg	  name of a bus system, i.e. the way the CPU talks to the other stuff
2714e279b6c1SSam Ravnborg	  inside your box.  Other bus systems are PCI, EISA, MicroChannel
2715e279b6c1SSam Ravnborg	  (MCA) or VESA.  ISA is an older system, now being displaced by PCI;
2716e279b6c1SSam Ravnborg	  newer boards don't support it.  If you have ISA, say Y, otherwise N.
2717e279b6c1SSam Ravnborg
2718e279b6c1SSam Ravnborgconfig SCx200
2719e279b6c1SSam Ravnborg	tristate "NatSemi SCx200 support"
2720a7f7f624SMasahiro Yamada	help
2721e279b6c1SSam Ravnborg	  This provides basic support for National Semiconductor's
2722e279b6c1SSam Ravnborg	  (now AMD's) Geode processors.  The driver probes for the
2723e279b6c1SSam Ravnborg	  PCI-IDs of several on-chip devices, so its a good dependency
2724e279b6c1SSam Ravnborg	  for other scx200_* drivers.
2725e279b6c1SSam Ravnborg
2726e279b6c1SSam Ravnborg	  If compiled as a module, the driver is named scx200.
2727e279b6c1SSam Ravnborg
2728e279b6c1SSam Ravnborgconfig SCx200HR_TIMER
2729e279b6c1SSam Ravnborg	tristate "NatSemi SCx200 27MHz High-Resolution Timer Support"
2730592913ecSJohn Stultz	depends on SCx200
2731e279b6c1SSam Ravnborg	default y
2732a7f7f624SMasahiro Yamada	help
2733e279b6c1SSam Ravnborg	  This driver provides a clocksource built upon the on-chip
2734e279b6c1SSam Ravnborg	  27MHz high-resolution timer.  Its also a workaround for
2735e279b6c1SSam Ravnborg	  NSC Geode SC-1100's buggy TSC, which loses time when the
2736e279b6c1SSam Ravnborg	  processor goes idle (as is done by the scheduler).  The
2737e279b6c1SSam Ravnborg	  other workaround is idle=poll boot option.
2738e279b6c1SSam Ravnborg
27393ef0e1f8SAndres Salomonconfig OLPC
27403ef0e1f8SAndres Salomon	bool "One Laptop Per Child support"
274154008979SThomas Gleixner	depends on !X86_PAE
27423c554946SAndres Salomon	select GPIOLIB
2743dc3119e7SThomas Gleixner	select OF
274445bb1674SDaniel Drake	select OF_PROMTREE
2745b4e51854SGrant Likely	select IRQ_DOMAIN
27460c3d931bSLubomir Rintel	select OLPC_EC
2747a7f7f624SMasahiro Yamada	help
27483ef0e1f8SAndres Salomon	  Add support for detecting the unique features of the OLPC
27493ef0e1f8SAndres Salomon	  XO hardware.
27503ef0e1f8SAndres Salomon
2751a3128588SDaniel Drakeconfig OLPC_XO1_PM
2752a3128588SDaniel Drake	bool "OLPC XO-1 Power Management"
2753fa112cf1SBorislav Petkov	depends on OLPC && MFD_CS5535=y && PM_SLEEP
2754a7f7f624SMasahiro Yamada	help
275597c4cb71SDaniel Drake	  Add support for poweroff and suspend of the OLPC XO-1 laptop.
2756bf1ebf00SDaniel Drake
2757cfee9597SDaniel Drakeconfig OLPC_XO1_RTC
2758cfee9597SDaniel Drake	bool "OLPC XO-1 Real Time Clock"
2759cfee9597SDaniel Drake	depends on OLPC_XO1_PM && RTC_DRV_CMOS
2760a7f7f624SMasahiro Yamada	help
2761cfee9597SDaniel Drake	  Add support for the XO-1 real time clock, which can be used as a
2762cfee9597SDaniel Drake	  programmable wakeup source.
2763cfee9597SDaniel Drake
27647feda8e9SDaniel Drakeconfig OLPC_XO1_SCI
27657feda8e9SDaniel Drake	bool "OLPC XO-1 SCI extras"
276692e830f2SArnd Bergmann	depends on OLPC && OLPC_XO1_PM && GPIO_CS5535=y
2767ed8e47feSRandy Dunlap	depends on INPUT=y
2768d8d01a63SDaniel Drake	select POWER_SUPPLY
2769a7f7f624SMasahiro Yamada	help
27707feda8e9SDaniel Drake	  Add support for SCI-based features of the OLPC XO-1 laptop:
27717bc74b3dSDaniel Drake	   - EC-driven system wakeups
27727feda8e9SDaniel Drake	   - Power button
27737bc74b3dSDaniel Drake	   - Ebook switch
27742cf2baeaSDaniel Drake	   - Lid switch
2775e1040ac6SDaniel Drake	   - AC adapter status updates
2776e1040ac6SDaniel Drake	   - Battery status updates
27777feda8e9SDaniel Drake
2778a0f30f59SDaniel Drakeconfig OLPC_XO15_SCI
2779a0f30f59SDaniel Drake	bool "OLPC XO-1.5 SCI extras"
2780d8d01a63SDaniel Drake	depends on OLPC && ACPI
2781d8d01a63SDaniel Drake	select POWER_SUPPLY
2782a7f7f624SMasahiro Yamada	help
2783a0f30f59SDaniel Drake	  Add support for SCI-based features of the OLPC XO-1.5 laptop:
2784a0f30f59SDaniel Drake	   - EC-driven system wakeups
2785a0f30f59SDaniel Drake	   - AC adapter status updates
2786a0f30f59SDaniel Drake	   - Battery status updates
2787e279b6c1SSam Ravnborg
2788d4f3e350SEd Wildgooseconfig ALIX
2789d4f3e350SEd Wildgoose	bool "PCEngines ALIX System Support (LED setup)"
2790d4f3e350SEd Wildgoose	select GPIOLIB
2791a7f7f624SMasahiro Yamada	help
2792d4f3e350SEd Wildgoose	  This option enables system support for the PCEngines ALIX.
2793d4f3e350SEd Wildgoose	  At present this just sets up LEDs for GPIO control on
2794d4f3e350SEd Wildgoose	  ALIX2/3/6 boards.  However, other system specific setup should
2795d4f3e350SEd Wildgoose	  get added here.
2796d4f3e350SEd Wildgoose
2797d4f3e350SEd Wildgoose	  Note: You must still enable the drivers for GPIO and LED support
2798d4f3e350SEd Wildgoose	  (GPIO_CS5535 & LEDS_GPIO) to actually use the LEDs
2799d4f3e350SEd Wildgoose
2800d4f3e350SEd Wildgoose	  Note: You have to set alix.force=1 for boards with Award BIOS.
2801d4f3e350SEd Wildgoose
2802da4e3302SPhilip Prindevilleconfig NET5501
2803da4e3302SPhilip Prindeville	bool "Soekris Engineering net5501 System Support (LEDS, GPIO, etc)"
2804da4e3302SPhilip Prindeville	select GPIOLIB
2805a7f7f624SMasahiro Yamada	help
2806da4e3302SPhilip Prindeville	  This option enables system support for the Soekris Engineering net5501.
2807da4e3302SPhilip Prindeville
28083197059aSPhilip A. Prindevilleconfig GEOS
28093197059aSPhilip A. Prindeville	bool "Traverse Technologies GEOS System Support (LEDS, GPIO, etc)"
28103197059aSPhilip A. Prindeville	select GPIOLIB
28113197059aSPhilip A. Prindeville	depends on DMI
2812a7f7f624SMasahiro Yamada	help
28133197059aSPhilip A. Prindeville	  This option enables system support for the Traverse Technologies GEOS.
28143197059aSPhilip A. Prindeville
28157d029125SVivien Didelotconfig TS5500
28167d029125SVivien Didelot	bool "Technologic Systems TS-5500 platform support"
28177d029125SVivien Didelot	depends on MELAN
28187d029125SVivien Didelot	select CHECK_SIGNATURE
28197d029125SVivien Didelot	select NEW_LEDS
28207d029125SVivien Didelot	select LEDS_CLASS
2821a7f7f624SMasahiro Yamada	help
28227d029125SVivien Didelot	  This option enables system support for the Technologic Systems TS-5500.
28237d029125SVivien Didelot
2824e279b6c1SSam Ravnborgendif # X86_32
2825e279b6c1SSam Ravnborg
282623ac4ae8SAndreas Herrmannconfig AMD_NB
2827e279b6c1SSam Ravnborg	def_bool y
28280e152cd7SBorislav Petkov	depends on CPU_SUP_AMD && PCI
2829e279b6c1SSam Ravnborg
2830e3263ab3SDavid Herrmannconfig X86_SYSFB
2831e3263ab3SDavid Herrmann	bool "Mark VGA/VBE/EFI FB as generic system framebuffer"
2832e3263ab3SDavid Herrmann	help
2833e3263ab3SDavid Herrmann	  Firmwares often provide initial graphics framebuffers so the BIOS,
2834e3263ab3SDavid Herrmann	  bootloader or kernel can show basic video-output during boot for
2835e3263ab3SDavid Herrmann	  user-guidance and debugging. Historically, x86 used the VESA BIOS
2836e3263ab3SDavid Herrmann	  Extensions and EFI-framebuffers for this, which are mostly limited
2837e3263ab3SDavid Herrmann	  to x86.
2838e3263ab3SDavid Herrmann	  This option, if enabled, marks VGA/VBE/EFI framebuffers as generic
2839e3263ab3SDavid Herrmann	  framebuffers so the new generic system-framebuffer drivers can be
2840e3263ab3SDavid Herrmann	  used on x86. If the framebuffer is not compatible with the generic
2841e3a5dc08SNikolas Nyby	  modes, it is advertised as fallback platform framebuffer so legacy
2842e3263ab3SDavid Herrmann	  drivers like efifb, vesafb and uvesafb can pick it up.
2843e3263ab3SDavid Herrmann	  If this option is not selected, all system framebuffers are always
2844e3263ab3SDavid Herrmann	  marked as fallback platform framebuffers as usual.
2845e3263ab3SDavid Herrmann
2846e3263ab3SDavid Herrmann	  Note: Legacy fbdev drivers, including vesafb, efifb, uvesafb, will
2847e3263ab3SDavid Herrmann	  not be able to pick up generic system framebuffers if this option
2848e3263ab3SDavid Herrmann	  is selected. You are highly encouraged to enable simplefb as
2849e3263ab3SDavid Herrmann	  replacement if you select this option. simplefb can correctly deal
2850e3263ab3SDavid Herrmann	  with generic system framebuffers. But you should still keep vesafb
2851e3263ab3SDavid Herrmann	  and others enabled as fallback if a system framebuffer is
2852e3263ab3SDavid Herrmann	  incompatible with simplefb.
2853e3263ab3SDavid Herrmann
2854e3263ab3SDavid Herrmann	  If unsure, say Y.
2855e3263ab3SDavid Herrmann
2856e279b6c1SSam Ravnborgendmenu
2857e279b6c1SSam Ravnborg
2858e279b6c1SSam Ravnborg
28591572497cSChristoph Hellwigmenu "Binary Emulations"
2860e279b6c1SSam Ravnborg
2861e279b6c1SSam Ravnborgconfig IA32_EMULATION
2862e279b6c1SSam Ravnborg	bool "IA32 Emulation"
2863e279b6c1SSam Ravnborg	depends on X86_64
286439f88911SIngo Molnar	select ARCH_WANT_OLD_COMPAT_IPC
2865d1603990SRandy Dunlap	select BINFMT_ELF
2866a97f52e6SRoland McGrath	select COMPAT_BINFMT_ELF
286739f88911SIngo Molnar	select COMPAT_OLD_SIGACTION
2868a7f7f624SMasahiro Yamada	help
28695fd92e65SH. J. Lu	  Include code to run legacy 32-bit programs under a
28705fd92e65SH. J. Lu	  64-bit kernel. You should likely turn this on, unless you're
28715fd92e65SH. J. Lu	  100% sure that you don't have any 32-bit programs left.
2872e279b6c1SSam Ravnborg
2873e279b6c1SSam Ravnborgconfig IA32_AOUT
2874e279b6c1SSam Ravnborg	tristate "IA32 a.out support"
28756b213e1bSDavid Woodhouse	depends on IA32_EMULATION
2876eac61655SBorislav Petkov	depends on BROKEN
2877a7f7f624SMasahiro Yamada	help
2878e279b6c1SSam Ravnborg	  Support old a.out binaries in the 32bit emulation.
2879e279b6c1SSam Ravnborg
28800bf62763SH. Peter Anvinconfig X86_X32
28816ea30386SKees Cook	bool "x32 ABI for 64-bit mode"
28829b54050bSBrian Gerst	depends on X86_64
2883a7f7f624SMasahiro Yamada	help
28845fd92e65SH. J. Lu	  Include code to run binaries for the x32 native 32-bit ABI
28855fd92e65SH. J. Lu	  for 64-bit processors.  An x32 process gets access to the
28865fd92e65SH. J. Lu	  full 64-bit register file and wide data path while leaving
28875fd92e65SH. J. Lu	  pointers at 32 bits for smaller memory footprint.
28885fd92e65SH. J. Lu
28895fd92e65SH. J. Lu	  You will need a recent binutils (2.22 or later) with
28905fd92e65SH. J. Lu	  elf32_x86_64 support enabled to compile a kernel with this
28915fd92e65SH. J. Lu	  option set.
28925fd92e65SH. J. Lu
2893953fee1dSIngo Molnarconfig COMPAT_32
2894953fee1dSIngo Molnar	def_bool y
2895953fee1dSIngo Molnar	depends on IA32_EMULATION || X86_32
2896953fee1dSIngo Molnar	select HAVE_UID16
2897953fee1dSIngo Molnar	select OLD_SIGSUSPEND3
2898953fee1dSIngo Molnar
2899e279b6c1SSam Ravnborgconfig COMPAT
29003c2362e6SHarvey Harrison	def_bool y
29010bf62763SH. Peter Anvin	depends on IA32_EMULATION || X86_X32
2902e279b6c1SSam Ravnborg
29033120e25eSJan Beulichif COMPAT
2904e279b6c1SSam Ravnborgconfig COMPAT_FOR_U64_ALIGNMENT
29053120e25eSJan Beulich	def_bool y
2906e279b6c1SSam Ravnborg
2907e279b6c1SSam Ravnborgconfig SYSVIPC_COMPAT
29083c2362e6SHarvey Harrison	def_bool y
29093120e25eSJan Beulich	depends on SYSVIPC
29103120e25eSJan Beulichendif
2911ee009e4aSDavid Howells
2912e279b6c1SSam Ravnborgendmenu
2913e279b6c1SSam Ravnborg
2914e279b6c1SSam Ravnborg
2915e5beae16SKeith Packardconfig HAVE_ATOMIC_IOMAP
2916e5beae16SKeith Packard	def_bool y
2917e5beae16SKeith Packard	depends on X86_32
2918e5beae16SKeith Packard
2919e279b6c1SSam Ravnborgsource "drivers/firmware/Kconfig"
2920e279b6c1SSam Ravnborg
2921edf88417SAvi Kivitysource "arch/x86/kvm/Kconfig"
29225e8ebd84SJason A. Donenfeld
29235e8ebd84SJason A. Donenfeldsource "arch/x86/Kconfig.assembler"
2924