xref: /linux/arch/x86/Kconfig (revision 50468e4313355b161cac8a5155a45832995b7f25)
1b2441318SGreg Kroah-Hartman# SPDX-License-Identifier: GPL-2.0
2daa93fabSSam Ravnborg# Select 32 or 64 bit
3daa93fabSSam Ravnborgconfig 64BIT
4104daea1SMasahiro Yamada	bool "64-bit kernel" if "$(ARCH)" = "x86"
5104daea1SMasahiro Yamada	default "$(ARCH)" != "i386"
6a7f7f624SMasahiro Yamada	help
7daa93fabSSam Ravnborg	  Say yes to build a 64-bit kernel - formerly known as x86_64
8daa93fabSSam Ravnborg	  Say no to build a 32-bit kernel - formerly known as i386
9daa93fabSSam Ravnborg
10daa93fabSSam Ravnborgconfig X86_32
113120e25eSJan Beulich	def_bool y
123120e25eSJan Beulich	depends on !64BIT
13341c787eSIngo Molnar	# Options that are inherently 32-bit kernel only:
14341c787eSIngo Molnar	select ARCH_WANT_IPC_PARSE_VERSION
15341c787eSIngo Molnar	select CLKSRC_I8253
16341c787eSIngo Molnar	select CLONE_BACKWARDS
17157e118bSThomas Gleixner	select GENERIC_VDSO_32
18117ed454SThomas Gleixner	select HAVE_DEBUG_STACKOVERFLOW
19157e118bSThomas Gleixner	select KMAP_LOCAL
20341c787eSIngo Molnar	select MODULES_USE_ELF_REL
21341c787eSIngo Molnar	select OLD_SIGACTION
222ca408d9SBrian Gerst	select ARCH_SPLIT_ARG64
23daa93fabSSam Ravnborg
24daa93fabSSam Ravnborgconfig X86_64
253120e25eSJan Beulich	def_bool y
263120e25eSJan Beulich	depends on 64BIT
27d94e0685SIngo Molnar	# Options that are inherently 64-bit kernel only:
284eb0716eSAlexandre Ghiti	select ARCH_HAS_GIGANTIC_PAGE
29c12d3362SArd Biesheuvel	select ARCH_SUPPORTS_INT128 if CC_HAS_INT128
30d94e0685SIngo Molnar	select ARCH_USE_CMPXCHG_LOCKREF
31d94e0685SIngo Molnar	select HAVE_ARCH_SOFT_DIRTY
32d94e0685SIngo Molnar	select MODULES_USE_ELF_RELA
33f616ab59SChristoph Hellwig	select NEED_DMA_MAP_STATE
3409230cbcSChristoph Hellwig	select SWIOTLB
357facdc42SAl Viro	select ARCH_HAS_ELFCORE_COMPAT
3663703f37SKefeng Wang	select ZONE_DMA32
371032c0baSSam Ravnborg
38518049d9SSteven Rostedt (VMware)config FORCE_DYNAMIC_FTRACE
39518049d9SSteven Rostedt (VMware)	def_bool y
40518049d9SSteven Rostedt (VMware)	depends on X86_32
41518049d9SSteven Rostedt (VMware)	depends on FUNCTION_TRACER
42518049d9SSteven Rostedt (VMware)	select DYNAMIC_FTRACE
43518049d9SSteven Rostedt (VMware)	help
44518049d9SSteven Rostedt (VMware)	 We keep the static function tracing (!DYNAMIC_FTRACE) around
45518049d9SSteven Rostedt (VMware)	 in order to test the non static function tracing in the
46518049d9SSteven Rostedt (VMware)	 generic code, as other architectures still use it. But we
47518049d9SSteven Rostedt (VMware)	 only need to keep it around for x86_64. No need to keep it
48518049d9SSteven Rostedt (VMware)	 for x86_32. For x86_32, force DYNAMIC_FTRACE.
49d94e0685SIngo Molnar#
50d94e0685SIngo Molnar# Arch settings
51d94e0685SIngo Molnar#
52d94e0685SIngo Molnar# ( Note that options that are marked 'if X86_64' could in principle be
53d94e0685SIngo Molnar#   ported to 32-bit as well. )
54d94e0685SIngo Molnar#
558d5fffb9SSam Ravnborgconfig X86
563c2362e6SHarvey Harrison	def_bool y
57c763ea26SIngo Molnar	#
58c763ea26SIngo Molnar	# Note: keep this list sorted alphabetically
59c763ea26SIngo Molnar	#
606471b825SIngo Molnar	select ACPI_LEGACY_TABLES_LOOKUP	if ACPI
616e0a0ea1SGraeme Gregory	select ACPI_SYSTEM_POWER_STATES_SUPPORT	if ACPI
62942fa985SYury Norov	select ARCH_32BIT_OFF_T			if X86_32
632a21ad57SThomas Gleixner	select ARCH_CLOCKSOURCE_INIT
641f6d3a8fSMasami Hiramatsu	select ARCH_CORRECT_STACKTRACE_ON_KRETPROBE
651e866974SAnshuman Khandual	select ARCH_ENABLE_HUGEPAGE_MIGRATION if X86_64 && HUGETLB_PAGE && MIGRATION
665c11f00bSDavid Hildenbrand	select ARCH_ENABLE_MEMORY_HOTPLUG if X86_64
6791024b3cSAnshuman Khandual	select ARCH_ENABLE_MEMORY_HOTREMOVE if MEMORY_HOTPLUG
68cebc774fSAnshuman Khandual	select ARCH_ENABLE_SPLIT_PMD_PTLOCK if (PGTABLE_LEVELS > 2) && (X86_64 || X86_PAE)
691e866974SAnshuman Khandual	select ARCH_ENABLE_THP_MIGRATION if X86_64 && TRANSPARENT_HUGEPAGE
7091dda51aSAleksey Makarov	select ARCH_HAS_ACPI_TABLE_UPGRADE	if ACPI
71c2280be8SAnshuman Khandual	select ARCH_HAS_CACHE_LINE_SIZE
72fa5b6ec9SLaura Abbott	select ARCH_HAS_DEBUG_VIRTUAL
73399145f9SAnshuman Khandual	select ARCH_HAS_DEBUG_VM_PGTABLE	if !X86_PAE
7421266be9SDan Williams	select ARCH_HAS_DEVMEM_IS_ALLOWED
75b1a57bbfSDouglas Anderson	select ARCH_HAS_EARLY_DEBUG		if KGDB
766471b825SIngo Molnar	select ARCH_HAS_ELF_RANDOMIZE
7772d93104SLinus Torvalds	select ARCH_HAS_FAST_MULTIPLIER
78316d097cSDave Hansen	select ARCH_HAS_FILTER_PGPROT
796974f0c4SDaniel Micay	select ARCH_HAS_FORTIFY_SOURCE
80957e3facSRiku Voipio	select ARCH_HAS_GCOV_PROFILE_ALL
810f1441b4SPeter Zijlstra	select ARCH_HAS_KCOV			if X86_64 && STACK_VALIDATION
820c9c1d56SThiago Jung Bauermann	select ARCH_HAS_MEM_ENCRYPT
8310bcc80eSMathieu Desnoyers	select ARCH_HAS_MEMBARRIER_SYNC_CORE
840ebeea8cSDaniel Borkmann	select ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE
85c763ea26SIngo Molnar	select ARCH_HAS_PMEM_API		if X86_64
8617596731SRobin Murphy	select ARCH_HAS_PTE_DEVMAP		if X86_64
873010a5eaSLaurent Dufour	select ARCH_HAS_PTE_SPECIAL
880aed55afSDan Williams	select ARCH_HAS_UACCESS_FLUSHCACHE	if X86_64
89ec6347bbSDan Williams	select ARCH_HAS_COPY_MC			if X86_64
90d2852a22SDaniel Borkmann	select ARCH_HAS_SET_MEMORY
91d253ca0cSRick Edgecombe	select ARCH_HAS_SET_DIRECT_MAP
92ad21fc4fSLaura Abbott	select ARCH_HAS_STRICT_KERNEL_RWX
93ad21fc4fSLaura Abbott	select ARCH_HAS_STRICT_MODULE_RWX
94ac1ab12aSMathieu Desnoyers	select ARCH_HAS_SYNC_CORE_BEFORE_USERMODE
9525c619e5SBrian Gerst	select ARCH_HAS_SYSCALL_WRAPPER
96c6d30853SAndrey Ryabinin	select ARCH_HAS_UBSAN_SANITIZE_ALL
977e01ccb4SZong Li	select ARCH_HAS_DEBUG_WX
9863703f37SKefeng Wang	select ARCH_HAS_ZONE_DMA_SET if EXPERT
996471b825SIngo Molnar	select ARCH_HAVE_NMI_SAFE_CMPXCHG
1006471b825SIngo Molnar	select ARCH_MIGHT_HAVE_ACPI_PDC		if ACPI
10177fbbc81SMark Salter	select ARCH_MIGHT_HAVE_PC_PARPORT
1025e2c18c0SMark Salter	select ARCH_MIGHT_HAVE_PC_SERIO
1033599fe12SThomas Gleixner	select ARCH_STACKWALK
1042c870e61SArnd Bergmann	select ARCH_SUPPORTS_ACPI
1056471b825SIngo Molnar	select ARCH_SUPPORTS_ATOMIC_RMW
1065d6ad668SMike Rapoport	select ARCH_SUPPORTS_DEBUG_PAGEALLOC
1076471b825SIngo Molnar	select ARCH_SUPPORTS_NUMA_BALANCING	if X86_64
10814df3267SThomas Gleixner	select ARCH_SUPPORTS_KMAP_LOCAL_FORCE_MAP	if NR_CPUS <= 4096
109583bfd48SNathan Chancellor	select ARCH_SUPPORTS_LTO_CLANG
110583bfd48SNathan Chancellor	select ARCH_SUPPORTS_LTO_CLANG_THIN
1116471b825SIngo Molnar	select ARCH_USE_BUILTIN_BSWAP
112dce44566SAnshuman Khandual	select ARCH_USE_MEMTEST
1136471b825SIngo Molnar	select ARCH_USE_QUEUED_RWLOCKS
1146471b825SIngo Molnar	select ARCH_USE_QUEUED_SPINLOCKS
1152ce0d7f9SMark Brown	select ARCH_USE_SYM_ANNOTATIONS
116ce4a4e56SAndy Lutomirski	select ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH
11781c22041SDaniel Borkmann	select ARCH_WANT_DEFAULT_BPF_JIT	if X86_64
118c763ea26SIngo Molnar	select ARCH_WANTS_DYNAMIC_TASK_STRUCT
11951c2ee6dSNick Desaulniers	select ARCH_WANTS_NO_INSTR
1203876d4a3SAlexandre Ghiti	select ARCH_WANT_HUGE_PMD_SHARE
12159612b24SNathan Chancellor	select ARCH_WANT_LD_ORPHAN_WARN
12238d8b4e6SHuang Ying	select ARCH_WANTS_THP_SWAP		if X86_64
123b5f06f64SBalbir Singh	select ARCH_HAS_PARANOID_L1D_FLUSH
12410916706SShile Zhang	select BUILDTIME_TABLE_SORT
1256471b825SIngo Molnar	select CLKEVT_I8253
1266471b825SIngo Molnar	select CLOCKSOURCE_VALIDATE_LAST_CYCLE
1276471b825SIngo Molnar	select CLOCKSOURCE_WATCHDOG
1286471b825SIngo Molnar	select DCACHE_WORD_ACCESS
1293aac3ebeSThomas Gleixner	select DYNAMIC_SIGFRAME
13045471cd9SLinus Torvalds	select EDAC_ATOMIC_SCRUB
13145471cd9SLinus Torvalds	select EDAC_SUPPORT
1326471b825SIngo Molnar	select GENERIC_CLOCKEVENTS_BROADCAST	if X86_64 || (X86_32 && X86_LOCAL_APIC)
1336471b825SIngo Molnar	select GENERIC_CLOCKEVENTS_MIN_ADJUST
1346471b825SIngo Molnar	select GENERIC_CMOS_UPDATE
1356471b825SIngo Molnar	select GENERIC_CPU_AUTOPROBE
13661dc0f55SThomas Gleixner	select GENERIC_CPU_VULNERABILITIES
1376471b825SIngo Molnar	select GENERIC_EARLY_IOREMAP
13827d6b4d1SThomas Gleixner	select GENERIC_ENTRY
1396471b825SIngo Molnar	select GENERIC_FIND_FIRST_BIT
1406471b825SIngo Molnar	select GENERIC_IOMAP
141c7d6c9ddSThomas Gleixner	select GENERIC_IRQ_EFFECTIVE_AFF_MASK	if SMP
1420fa115daSThomas Gleixner	select GENERIC_IRQ_MATRIX_ALLOCATOR	if X86_LOCAL_APIC
143ad7a929fSThomas Gleixner	select GENERIC_IRQ_MIGRATION		if SMP
1446471b825SIngo Molnar	select GENERIC_IRQ_PROBE
145c201c917SThomas Gleixner	select GENERIC_IRQ_RESERVATION_MODE
1466471b825SIngo Molnar	select GENERIC_IRQ_SHOW
1476471b825SIngo Molnar	select GENERIC_PENDING_IRQ		if SMP
1482ae27137SSteven Price	select GENERIC_PTDUMP
1496471b825SIngo Molnar	select GENERIC_SMP_IDLE_THREAD
1506471b825SIngo Molnar	select GENERIC_TIME_VSYSCALL
1517ac87074SVincenzo Frascino	select GENERIC_GETTIMEOFDAY
152550a77a7SDmitry Safonov	select GENERIC_VDSO_TIME_NS
15339656e83SChristoph Hellwig	select GUP_GET_PTE_LOW_HIGH		if X86_PAE
15417e5888eSHans de Goede	select HARDIRQS_SW_RESEND
1557edaeb68SThomas Gleixner	select HARDLOCKUP_CHECK_TIMESTAMP	if X86_64
1566471b825SIngo Molnar	select HAVE_ACPI_APEI			if ACPI
1576471b825SIngo Molnar	select HAVE_ACPI_APEI_NMI		if ACPI
1586471b825SIngo Molnar	select HAVE_ALIGNED_STRUCT_PAGE		if SLUB
1596471b825SIngo Molnar	select HAVE_ARCH_AUDITSYSCALL
1606471b825SIngo Molnar	select HAVE_ARCH_HUGE_VMAP		if X86_64 || X86_PAE
1616471b825SIngo Molnar	select HAVE_ARCH_JUMP_LABEL
162b34006c4SArd Biesheuvel	select HAVE_ARCH_JUMP_LABEL_RELATIVE
163d17a1d97SAndrey Ryabinin	select HAVE_ARCH_KASAN			if X86_64
1640609ae01SDaniel Axtens	select HAVE_ARCH_KASAN_VMALLOC		if X86_64
1651dc0da6eSAlexander Potapenko	select HAVE_ARCH_KFENCE
1666471b825SIngo Molnar	select HAVE_ARCH_KGDB
1679e08f57dSDaniel Cashman	select HAVE_ARCH_MMAP_RND_BITS		if MMU
1689e08f57dSDaniel Cashman	select HAVE_ARCH_MMAP_RND_COMPAT_BITS	if MMU && COMPAT
1691b028f78SDmitry Safonov	select HAVE_ARCH_COMPAT_MMAP_BASES	if MMU && COMPAT
170271ca788SArd Biesheuvel	select HAVE_ARCH_PREL32_RELOCATIONS
1716471b825SIngo Molnar	select HAVE_ARCH_SECCOMP_FILTER
172f7d83c1cSKees Cook	select HAVE_ARCH_THREAD_STRUCT_WHITELIST
173afaef01cSAlexander Popov	select HAVE_ARCH_STACKLEAK
1746471b825SIngo Molnar	select HAVE_ARCH_TRACEHOOK
1756471b825SIngo Molnar	select HAVE_ARCH_TRANSPARENT_HUGEPAGE
176a00cc7d9SMatthew Wilcox	select HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD if X86_64
177b64d8d1eSPeter Xu	select HAVE_ARCH_USERFAULTFD_WP         if X86_64 && USERFAULTFD
1787677f7fdSAxel Rasmussen	select HAVE_ARCH_USERFAULTFD_MINOR	if X86_64 && USERFAULTFD
179e37e43a4SAndy Lutomirski	select HAVE_ARCH_VMAP_STACK		if X86_64
180fe950f60SKees Cook	select HAVE_ARCH_RANDOMIZE_KSTACK_OFFSET
181c763ea26SIngo Molnar	select HAVE_ARCH_WITHIN_STACK_FRAMES
1822ff2b7ecSMasahiro Yamada	select HAVE_ASM_MODVERSIONS
1836471b825SIngo Molnar	select HAVE_CMPXCHG_DOUBLE
1846471b825SIngo Molnar	select HAVE_CMPXCHG_LOCAL
1856471b825SIngo Molnar	select HAVE_CONTEXT_TRACKING		if X86_64
186d1f250e2SFrederic Weisbecker	select HAVE_CONTEXT_TRACKING_OFFSTACK	if HAVE_CONTEXT_TRACKING
1876471b825SIngo Molnar	select HAVE_C_RECORDMCOUNT
1886dafca97SSami Tolvanen	select HAVE_OBJTOOL_MCOUNT		if STACK_VALIDATION
1896471b825SIngo Molnar	select HAVE_DEBUG_KMEMLEAK
1909c5a3621SAkinobu Mita	select HAVE_DMA_CONTIGUOUS
191677aa9f7SSteven Rostedt	select HAVE_DYNAMIC_FTRACE
19206aeaaeaSMasami Hiramatsu	select HAVE_DYNAMIC_FTRACE_WITH_REGS
19302a474caSSteven Rostedt (VMware)	select HAVE_DYNAMIC_FTRACE_WITH_ARGS	if X86_64
194562955feSSteven Rostedt (VMware)	select HAVE_DYNAMIC_FTRACE_WITH_DIRECT_CALLS
195c316eb44SHeiko Carstens	select HAVE_SAMPLE_FTRACE_DIRECT	if X86_64
1960b707e57SLinus Torvalds	select HAVE_SAMPLE_FTRACE_MULTI_DIRECT	if X86_64
19703f5781bSWang YanQing	select HAVE_EBPF_JIT
19858340a07SJohannes Berg	select HAVE_EFFICIENT_UNALIGNED_ACCESS
1996630a8e5SChristoph Hellwig	select HAVE_EISA
2005f56a5dfSJiri Slaby	select HAVE_EXIT_THREAD
20167a929e0SChristoph Hellwig	select HAVE_FAST_GUP
202644e0e8dSSteven Rostedt (VMware)	select HAVE_FENTRY			if X86_64 || DYNAMIC_FTRACE
2036471b825SIngo Molnar	select HAVE_FTRACE_MCOUNT_RECORD
2044a30e4c9SSteven Rostedt (VMware)	select HAVE_FUNCTION_GRAPH_TRACER	if X86_32 || (X86_64 && DYNAMIC_FTRACE)
2056471b825SIngo Molnar	select HAVE_FUNCTION_TRACER
2066b90bd4bSEmese Revfy	select HAVE_GCC_PLUGINS
2070067f129SK.Prasad	select HAVE_HW_BREAKPOINT
2086471b825SIngo Molnar	select HAVE_IOREMAP_PROT
209624db9eaSThomas Gleixner	select HAVE_IRQ_EXIT_ON_IRQ_STACK	if X86_64
2106471b825SIngo Molnar	select HAVE_IRQ_TIME_ACCOUNTING
2116471b825SIngo Molnar	select HAVE_KERNEL_BZIP2
2126471b825SIngo Molnar	select HAVE_KERNEL_GZIP
2136471b825SIngo Molnar	select HAVE_KERNEL_LZ4
2146471b825SIngo Molnar	select HAVE_KERNEL_LZMA
2156471b825SIngo Molnar	select HAVE_KERNEL_LZO
2166471b825SIngo Molnar	select HAVE_KERNEL_XZ
217fb46d057SNick Terrell	select HAVE_KERNEL_ZSTD
2186471b825SIngo Molnar	select HAVE_KPROBES
2196471b825SIngo Molnar	select HAVE_KPROBES_ON_FTRACE
220540adea3SMasami Hiramatsu	select HAVE_FUNCTION_ERROR_INJECTION
2216471b825SIngo Molnar	select HAVE_KRETPROBES
2226471b825SIngo Molnar	select HAVE_KVM
2236471b825SIngo Molnar	select HAVE_LIVEPATCH			if X86_64
2240102752eSFrederic Weisbecker	select HAVE_MIXED_BREAKPOINTS_REGS
225ee9f8fceSJosh Poimboeuf	select HAVE_MOD_ARCH_SPECIFIC
2269f132f7eSJoel Fernandes (Google)	select HAVE_MOVE_PMD
227be37c98dSKalesh Singh	select HAVE_MOVE_PUD
22842a0bb3fSPetr Mladek	select HAVE_NMI
2296471b825SIngo Molnar	select HAVE_OPTPROBES
2306471b825SIngo Molnar	select HAVE_PCSPKR_PLATFORM
2316471b825SIngo Molnar	select HAVE_PERF_EVENTS
232c01d4323SFrederic Weisbecker	select HAVE_PERF_EVENTS_NMI
23392e5aae4SNicholas Piggin	select HAVE_HARDLOCKUP_DETECTOR_PERF	if PERF_EVENTS && HAVE_PERF_EVENTS_NMI
234eb01d42aSChristoph Hellwig	select HAVE_PCI
235c5e63197SJiri Olsa	select HAVE_PERF_REGS
236c5ebcedbSJiri Olsa	select HAVE_PERF_USER_STACK_DUMP
237ff2e6d72SPeter Zijlstra	select MMU_GATHER_RCU_TABLE_FREE		if PARAVIRT
23800998085SThomas Gleixner	select HAVE_POSIX_CPU_TIMERS_TASK_WORK
2396471b825SIngo Molnar	select HAVE_REGS_AND_STACK_ACCESS_API
2406415b38bSJiri Slaby	select HAVE_RELIABLE_STACKTRACE		if X86_64 && (UNWINDER_FRAME_POINTER || UNWINDER_ORC) && STACK_VALIDATION
2413c88ee19SMasami Hiramatsu	select HAVE_FUNCTION_ARG_ACCESS_API
242cd1a41ceSThomas Gleixner	select HAVE_SOFTIRQ_ON_OWN_STACK
243d148eac0SMasahiro Yamada	select HAVE_STACKPROTECTOR		if CC_HAS_SANE_STACKPROTECTOR
244c763ea26SIngo Molnar	select HAVE_STACK_VALIDATION		if X86_64
245e6d6c071SJosh Poimboeuf	select HAVE_STATIC_CALL
2461e7e4788SJosh Poimboeuf	select HAVE_STATIC_CALL_INLINE		if HAVE_STACK_VALIDATION
2476ef869e0SMichal Hocko	select HAVE_PREEMPT_DYNAMIC
248d6761b8fSMathieu Desnoyers	select HAVE_RSEQ
2496471b825SIngo Molnar	select HAVE_SYSCALL_TRACEPOINTS
2506471b825SIngo Molnar	select HAVE_UNSTABLE_SCHED_CLOCK
2517c68af6eSAvi Kivity	select HAVE_USER_RETURN_NOTIFIER
2527ac87074SVincenzo Frascino	select HAVE_GENERIC_VDSO
25305736e4aSThomas Gleixner	select HOTPLUG_SMT			if SMP
254c0185808SThomas Gleixner	select IRQ_FORCED_THREADING
25586596f0aSChristoph Hellwig	select NEED_SG_DMA_LENGTH
2562eac9c2dSChristoph Hellwig	select PCI_DOMAINS			if PCI
257625210cfSSinan Kaya	select PCI_LOCKLESS_CONFIG		if PCI
2586471b825SIngo Molnar	select PERF_EVENTS
2593195ef59SPrarit Bhargava	select RTC_LIB
260d6faca40SArnd Bergmann	select RTC_MC146818_LIB
2616471b825SIngo Molnar	select SPARSE_IRQ
26283fe27eaSPranith Kumar	select SRCU
2631e7e4788SJosh Poimboeuf	select STACK_VALIDATION			if HAVE_STACK_VALIDATION && (HAVE_STATIC_CALL_INLINE || RETPOLINE)
2646471b825SIngo Molnar	select SYSCTL_EXCEPTION_TRACE
26515f4eae7SAndy Lutomirski	select THREAD_INFO_IN_TASK
2664aae683fSMasahiro Yamada	select TRACE_IRQFLAGS_SUPPORT
2676471b825SIngo Molnar	select USER_STACKTRACE_SUPPORT
2686471b825SIngo Molnar	select VIRT_TO_BUS
2693b02a051SIngo Molnar	select HAVE_ARCH_KCSAN			if X86_64
2706471b825SIngo Molnar	select X86_FEATURE_NAMES		if PROC_FS
2710c608dadSAubrey Li	select PROC_PID_ARCH_STATUS		if PROC_FS
272*50468e43SJarkko Sakkinen	select HAVE_ARCH_NODE_DEV_GROUP		if X86_SGX
2739e2b4be3SNayna Jain	imply IMA_SECURE_AND_OR_TRUSTED_BOOT    if EFI
2747d8330a5SBalbir Singh
275ba7e4d13SIngo Molnarconfig INSTRUCTION_DECODER
2763120e25eSJan Beulich	def_bool y
2773120e25eSJan Beulich	depends on KPROBES || PERF_EVENTS || UPROBES
278ba7e4d13SIngo Molnar
27951b26adaSLinus Torvaldsconfig OUTPUT_FORMAT
28051b26adaSLinus Torvalds	string
28151b26adaSLinus Torvalds	default "elf32-i386" if X86_32
28251b26adaSLinus Torvalds	default "elf64-x86-64" if X86_64
28351b26adaSLinus Torvalds
2848d5fffb9SSam Ravnborgconfig LOCKDEP_SUPPORT
2853c2362e6SHarvey Harrison	def_bool y
2868d5fffb9SSam Ravnborg
2878d5fffb9SSam Ravnborgconfig STACKTRACE_SUPPORT
2883c2362e6SHarvey Harrison	def_bool y
2898d5fffb9SSam Ravnborg
2908d5fffb9SSam Ravnborgconfig MMU
2913c2362e6SHarvey Harrison	def_bool y
2928d5fffb9SSam Ravnborg
2939e08f57dSDaniel Cashmanconfig ARCH_MMAP_RND_BITS_MIN
2949e08f57dSDaniel Cashman	default 28 if 64BIT
2959e08f57dSDaniel Cashman	default 8
2969e08f57dSDaniel Cashman
2979e08f57dSDaniel Cashmanconfig ARCH_MMAP_RND_BITS_MAX
2989e08f57dSDaniel Cashman	default 32 if 64BIT
2999e08f57dSDaniel Cashman	default 16
3009e08f57dSDaniel Cashman
3019e08f57dSDaniel Cashmanconfig ARCH_MMAP_RND_COMPAT_BITS_MIN
3029e08f57dSDaniel Cashman	default 8
3039e08f57dSDaniel Cashman
3049e08f57dSDaniel Cashmanconfig ARCH_MMAP_RND_COMPAT_BITS_MAX
3059e08f57dSDaniel Cashman	default 16
3069e08f57dSDaniel Cashman
3078d5fffb9SSam Ravnborgconfig SBUS
3088d5fffb9SSam Ravnborg	bool
3098d5fffb9SSam Ravnborg
3108d5fffb9SSam Ravnborgconfig GENERIC_ISA_DMA
3113120e25eSJan Beulich	def_bool y
3123120e25eSJan Beulich	depends on ISA_DMA_API
3138d5fffb9SSam Ravnborg
3148d5fffb9SSam Ravnborgconfig GENERIC_BUG
3153c2362e6SHarvey Harrison	def_bool y
3168d5fffb9SSam Ravnborg	depends on BUG
317b93a531eSJan Beulich	select GENERIC_BUG_RELATIVE_POINTERS if X86_64
318b93a531eSJan Beulich
319b93a531eSJan Beulichconfig GENERIC_BUG_RELATIVE_POINTERS
320b93a531eSJan Beulich	bool
3218d5fffb9SSam Ravnborg
3228d5fffb9SSam Ravnborgconfig ARCH_MAY_HAVE_PC_FDC
3233120e25eSJan Beulich	def_bool y
3243120e25eSJan Beulich	depends on ISA_DMA_API
3258d5fffb9SSam Ravnborg
3261032c0baSSam Ravnborgconfig GENERIC_CALIBRATE_DELAY
3271032c0baSSam Ravnborg	def_bool y
3281032c0baSSam Ravnborg
3299a0b8415Svenkatesh.pallipadi@intel.comconfig ARCH_HAS_CPU_RELAX
3309a0b8415Svenkatesh.pallipadi@intel.com	def_bool y
3318d5fffb9SSam Ravnborg
332316d097cSDave Hansenconfig ARCH_HAS_FILTER_PGPROT
333316d097cSDave Hansen	def_bool y
334316d097cSDave Hansen
335dd5af90aSMike Travisconfig HAVE_SETUP_PER_CPU_AREA
33689c9c4c5SBrian Gerst	def_bool y
337b32ef636Stravis@sgi.com
33808fc4580STejun Heoconfig NEED_PER_CPU_EMBED_FIRST_CHUNK
33908fc4580STejun Heo	def_bool y
34008fc4580STejun Heo
34108fc4580STejun Heoconfig NEED_PER_CPU_PAGE_FIRST_CHUNK
34211124411STejun Heo	def_bool y
34311124411STejun Heo
344801e4062SJohannes Bergconfig ARCH_HIBERNATION_POSSIBLE
345801e4062SJohannes Berg	def_bool y
346801e4062SJohannes Berg
347d7109fe3SAndy Shevchenkoconfig ARCH_NR_GPIO
348d7109fe3SAndy Shevchenko	int
349d7109fe3SAndy Shevchenko	default 1024 if X86_64
350d7109fe3SAndy Shevchenko	default 512
351d7109fe3SAndy Shevchenko
352f4cb5700SJohannes Bergconfig ARCH_SUSPEND_POSSIBLE
353f4cb5700SJohannes Berg	def_bool y
354f4cb5700SJohannes Berg
35553313b2cSSteve Capperconfig ARCH_WANT_GENERAL_HUGETLB
35653313b2cSSteve Capper	def_bool y
35753313b2cSSteve Capper
3588d5fffb9SSam Ravnborgconfig AUDIT_ARCH
359e0fd24a3SJan Beulich	def_bool y if X86_64
3608d5fffb9SSam Ravnborg
361d6f2d75aSAndrey Ryabininconfig KASAN_SHADOW_OFFSET
362d6f2d75aSAndrey Ryabinin	hex
363d6f2d75aSAndrey Ryabinin	depends on KASAN
364d6f2d75aSAndrey Ryabinin	default 0xdffffc0000000000
365d6f2d75aSAndrey Ryabinin
36669575d38SShane Wangconfig HAVE_INTEL_TXT
36769575d38SShane Wang	def_bool y
3686ea30386SKees Cook	depends on INTEL_IOMMU && ACPI
36969575d38SShane Wang
3706b0c3d44SSam Ravnborgconfig X86_32_SMP
3716b0c3d44SSam Ravnborg	def_bool y
3726b0c3d44SSam Ravnborg	depends on X86_32 && SMP
3736b0c3d44SSam Ravnborg
3746b0c3d44SSam Ravnborgconfig X86_64_SMP
3756b0c3d44SSam Ravnborg	def_bool y
3766b0c3d44SSam Ravnborg	depends on X86_64 && SMP
3776b0c3d44SSam Ravnborg
3782b144498SSrikar Dronamrajuconfig ARCH_SUPPORTS_UPROBES
3792b144498SSrikar Dronamraju	def_bool y
3802b144498SSrikar Dronamraju
381d20642f0SRob Herringconfig FIX_EARLYCON_MEM
382d20642f0SRob Herring	def_bool y
383d20642f0SRob Herring
38494d49eb3SKirill A. Shutemovconfig DYNAMIC_PHYSICAL_MASK
38594d49eb3SKirill A. Shutemov	bool
38694d49eb3SKirill A. Shutemov
38798233368SKirill A. Shutemovconfig PGTABLE_LEVELS
38898233368SKirill A. Shutemov	int
38977ef56e4SKirill A. Shutemov	default 5 if X86_5LEVEL
39098233368SKirill A. Shutemov	default 4 if X86_64
39198233368SKirill A. Shutemov	default 3 if X86_PAE
39298233368SKirill A. Shutemov	default 2
39398233368SKirill A. Shutemov
3942a61f474SMasahiro Yamadaconfig CC_HAS_SANE_STACKPROTECTOR
3952a61f474SMasahiro Yamada	bool
3962a61f474SMasahiro Yamada	default $(success,$(srctree)/scripts/gcc-x86_64-has-stack-protector.sh $(CC)) if 64BIT
3972a61f474SMasahiro Yamada	default $(success,$(srctree)/scripts/gcc-x86_32-has-stack-protector.sh $(CC))
3982a61f474SMasahiro Yamada	help
3992a61f474SMasahiro Yamada	   We have to make sure stack protector is unconditionally disabled if
4003fb0fdb3SAndy Lutomirski	   the compiler produces broken code or if it does not let us control
4013fb0fdb3SAndy Lutomirski	   the segment on 32-bit kernels.
4022a61f474SMasahiro Yamada
403506f1d07SSam Ravnborgmenu "Processor type and features"
404506f1d07SSam Ravnborg
405506f1d07SSam Ravnborgconfig SMP
406506f1d07SSam Ravnborg	bool "Symmetric multi-processing support"
407a7f7f624SMasahiro Yamada	help
408506f1d07SSam Ravnborg	  This enables support for systems with more than one CPU. If you have
4094a474157SRobert Graffham	  a system with only one CPU, say N. If you have a system with more
4104a474157SRobert Graffham	  than one CPU, say Y.
411506f1d07SSam Ravnborg
4124a474157SRobert Graffham	  If you say N here, the kernel will run on uni- and multiprocessor
413506f1d07SSam Ravnborg	  machines, but will use only one CPU of a multiprocessor machine. If
414506f1d07SSam Ravnborg	  you say Y here, the kernel will run on many, but not all,
4154a474157SRobert Graffham	  uniprocessor machines. On a uniprocessor machine, the kernel
416506f1d07SSam Ravnborg	  will run faster if you say N here.
417506f1d07SSam Ravnborg
418506f1d07SSam Ravnborg	  Note that if you say Y here and choose architecture "586" or
419506f1d07SSam Ravnborg	  "Pentium" under "Processor family", the kernel will not work on 486
420506f1d07SSam Ravnborg	  architectures. Similarly, multiprocessor kernels for the "PPro"
421506f1d07SSam Ravnborg	  architecture may not work on all Pentium based boards.
422506f1d07SSam Ravnborg
423506f1d07SSam Ravnborg	  People using multiprocessor machines who say Y here should also say
424506f1d07SSam Ravnborg	  Y to "Enhanced Real Time Clock Support", below. The "Advanced Power
425506f1d07SSam Ravnborg	  Management" code will be disabled if you say Y here.
426506f1d07SSam Ravnborg
427cb1aaebeSMauro Carvalho Chehab	  See also <file:Documentation/x86/i386/IO-APIC.rst>,
4284f4cfa6cSMauro Carvalho Chehab	  <file:Documentation/admin-guide/lockup-watchdogs.rst> and the SMP-HOWTO available at
429506f1d07SSam Ravnborg	  <http://www.tldp.org/docs.html#howto>.
430506f1d07SSam Ravnborg
431506f1d07SSam Ravnborg	  If you don't know what to do here, say N.
432506f1d07SSam Ravnborg
4339def39beSJosh Triplettconfig X86_FEATURE_NAMES
4349def39beSJosh Triplett	bool "Processor feature human-readable names" if EMBEDDED
4359def39beSJosh Triplett	default y
436a7f7f624SMasahiro Yamada	help
4379def39beSJosh Triplett	  This option compiles in a table of x86 feature bits and corresponding
4389def39beSJosh Triplett	  names.  This is required to support /proc/cpuinfo and a few kernel
4399def39beSJosh Triplett	  messages.  You can disable this to save space, at the expense of
4409def39beSJosh Triplett	  making those few kernel messages show numeric feature bits instead.
4419def39beSJosh Triplett
4429def39beSJosh Triplett	  If in doubt, say Y.
4439def39beSJosh Triplett
44406cd9a7dSYinghai Luconfig X86_X2APIC
44506cd9a7dSYinghai Lu	bool "Support x2apic"
44619e3d60dSJan Kiszka	depends on X86_LOCAL_APIC && X86_64 && (IRQ_REMAP || HYPERVISOR_GUEST)
447a7f7f624SMasahiro Yamada	help
44806cd9a7dSYinghai Lu	  This enables x2apic support on CPUs that have this feature.
44906cd9a7dSYinghai Lu
45006cd9a7dSYinghai Lu	  This allows 32-bit apic IDs (so it can support very large systems),
45106cd9a7dSYinghai Lu	  and accesses the local apic via MSRs not via mmio.
45206cd9a7dSYinghai Lu
45306cd9a7dSYinghai Lu	  If you don't know what to do here, say N.
45406cd9a7dSYinghai Lu
4556695c85bSYinghai Luconfig X86_MPPARSE
4564590d98fSAndy Shevchenko	bool "Enable MPS table" if ACPI
4577a527688SJan Beulich	default y
4585ab74722SIngo Molnar	depends on X86_LOCAL_APIC
459a7f7f624SMasahiro Yamada	help
4606695c85bSYinghai Lu	  For old smp systems that do not have proper acpi support. Newer systems
4616695c85bSYinghai Lu	  (esp with 64bit cpus) with acpi support, MADT and DSDT will override it
4626695c85bSYinghai Lu
463ddd70cf9SJun Nakajimaconfig GOLDFISH
464ddd70cf9SJun Nakajima	def_bool y
465ddd70cf9SJun Nakajima	depends on X86_GOLDFISH
466ddd70cf9SJun Nakajima
46776b04384SDavid Woodhouseconfig RETPOLINE
46876b04384SDavid Woodhouse	bool "Avoid speculative indirect branches in kernel"
46976b04384SDavid Woodhouse	default y
47076b04384SDavid Woodhouse	help
47176b04384SDavid Woodhouse	  Compile kernel with the retpoline compiler options to guard against
47276b04384SDavid Woodhouse	  kernel-to-user data leaks by avoiding speculative indirect
47376b04384SDavid Woodhouse	  branches. Requires a compiler with -mindirect-branch=thunk-extern
47476b04384SDavid Woodhouse	  support for full protection. The kernel may run slower.
47576b04384SDavid Woodhouse
476e6d42931SJohannes Weinerconfig X86_CPU_RESCTRL
477e6d42931SJohannes Weiner	bool "x86 CPU resource control support"
4786fe07ce3SBabu Moger	depends on X86 && (CPU_SUP_INTEL || CPU_SUP_AMD)
47959fe5a77SThomas Gleixner	select KERNFS
480e79f15a4SChen Yu	select PROC_CPU_RESCTRL		if PROC_FS
48178e99b4aSFenghua Yu	help
482e6d42931SJohannes Weiner	  Enable x86 CPU resource control support.
4836fe07ce3SBabu Moger
4846fe07ce3SBabu Moger	  Provide support for the allocation and monitoring of system resources
4856fe07ce3SBabu Moger	  usage by the CPU.
4866fe07ce3SBabu Moger
4876fe07ce3SBabu Moger	  Intel calls this Intel Resource Director Technology
4886fe07ce3SBabu Moger	  (Intel(R) RDT). More information about RDT can be found in the
4896fe07ce3SBabu Moger	  Intel x86 Architecture Software Developer Manual.
4906fe07ce3SBabu Moger
4916fe07ce3SBabu Moger	  AMD calls this AMD Platform Quality of Service (AMD QoS).
4926fe07ce3SBabu Moger	  More information about AMD QoS can be found in the AMD64 Technology
4936fe07ce3SBabu Moger	  Platform Quality of Service Extensions manual.
49478e99b4aSFenghua Yu
49578e99b4aSFenghua Yu	  Say N if unsure.
49678e99b4aSFenghua Yu
4978425091fSRavikiran G Thirumalaiif X86_32
498a0d0bb4dSRandy Dunlapconfig X86_BIGSMP
499a0d0bb4dSRandy Dunlap	bool "Support for big SMP systems with more than 8 CPUs"
500a0d0bb4dSRandy Dunlap	depends on SMP
501a7f7f624SMasahiro Yamada	help
502e133f6eaSRandy Dunlap	  This option is needed for the systems that have more than 8 CPUs.
503a0d0bb4dSRandy Dunlap
504c5c606d9SRavikiran G Thirumalaiconfig X86_EXTENDED_PLATFORM
505c5c606d9SRavikiran G Thirumalai	bool "Support for extended (non-PC) x86 platforms"
506c5c606d9SRavikiran G Thirumalai	default y
507a7f7f624SMasahiro Yamada	help
50806ac8346SIngo Molnar	  If you disable this option then the kernel will only support
50906ac8346SIngo Molnar	  standard PC platforms. (which covers the vast majority of
51006ac8346SIngo Molnar	  systems out there.)
51106ac8346SIngo Molnar
5128425091fSRavikiran G Thirumalai	  If you enable this option then you'll be able to select support
5138425091fSRavikiran G Thirumalai	  for the following (non-PC) 32 bit x86 platforms:
514cb7b8023SBen Hutchings		Goldfish (Android emulator)
5158425091fSRavikiran G Thirumalai		AMD Elan
5168425091fSRavikiran G Thirumalai		RDC R-321x SoC
5178425091fSRavikiran G Thirumalai		SGI 320/540 (Visual Workstation)
51883125a3aSAlessandro Rubini		STA2X11-based (e.g. Northville)
5193f4110a4SThomas Gleixner		Moorestown MID devices
52006ac8346SIngo Molnar
52106ac8346SIngo Molnar	  If you have one of these systems, or if you want to build a
52206ac8346SIngo Molnar	  generic distribution kernel, say Y here - otherwise say N.
5238425091fSRavikiran G Thirumalaiendif
52406ac8346SIngo Molnar
5258425091fSRavikiran G Thirumalaiif X86_64
5268425091fSRavikiran G Thirumalaiconfig X86_EXTENDED_PLATFORM
5278425091fSRavikiran G Thirumalai	bool "Support for extended (non-PC) x86 platforms"
5288425091fSRavikiran G Thirumalai	default y
529a7f7f624SMasahiro Yamada	help
5308425091fSRavikiran G Thirumalai	  If you disable this option then the kernel will only support
5318425091fSRavikiran G Thirumalai	  standard PC platforms. (which covers the vast majority of
5328425091fSRavikiran G Thirumalai	  systems out there.)
5338425091fSRavikiran G Thirumalai
5348425091fSRavikiran G Thirumalai	  If you enable this option then you'll be able to select support
5358425091fSRavikiran G Thirumalai	  for the following (non-PC) 64 bit x86 platforms:
53644b111b5SSteffen Persvold		Numascale NumaChip
5378425091fSRavikiran G Thirumalai		ScaleMP vSMP
5388425091fSRavikiran G Thirumalai		SGI Ultraviolet
5398425091fSRavikiran G Thirumalai
5408425091fSRavikiran G Thirumalai	  If you have one of these systems, or if you want to build a
5418425091fSRavikiran G Thirumalai	  generic distribution kernel, say Y here - otherwise say N.
5428425091fSRavikiran G Thirumalaiendif
543c5c606d9SRavikiran G Thirumalai# This is an alphabetically sorted list of 64 bit extended platforms
544c5c606d9SRavikiran G Thirumalai# Please maintain the alphabetic order if and when there are additions
54544b111b5SSteffen Persvoldconfig X86_NUMACHIP
54644b111b5SSteffen Persvold	bool "Numascale NumaChip"
54744b111b5SSteffen Persvold	depends on X86_64
54844b111b5SSteffen Persvold	depends on X86_EXTENDED_PLATFORM
54944b111b5SSteffen Persvold	depends on NUMA
55044b111b5SSteffen Persvold	depends on SMP
55144b111b5SSteffen Persvold	depends on X86_X2APIC
552f9726bfdSDaniel J Blueman	depends on PCI_MMCONFIG
553a7f7f624SMasahiro Yamada	help
55444b111b5SSteffen Persvold	  Adds support for Numascale NumaChip large-SMP systems. Needed to
55544b111b5SSteffen Persvold	  enable more than ~168 cores.
55644b111b5SSteffen Persvold	  If you don't have one of these, you should say N here.
55703b48632SNick Piggin
5586a48565eSIngo Molnarconfig X86_VSMP
559c5c606d9SRavikiran G Thirumalai	bool "ScaleMP vSMP"
5606276a074SBorislav Petkov	select HYPERVISOR_GUEST
5616a48565eSIngo Molnar	select PARAVIRT
5626a48565eSIngo Molnar	depends on X86_64 && PCI
563c5c606d9SRavikiran G Thirumalai	depends on X86_EXTENDED_PLATFORM
564ead91d4bSShai Fultheim	depends on SMP
565a7f7f624SMasahiro Yamada	help
5666a48565eSIngo Molnar	  Support for ScaleMP vSMP systems.  Say 'Y' here if this kernel is
5676a48565eSIngo Molnar	  supposed to run on these EM64T-based machines.  Only choose this option
5686a48565eSIngo Molnar	  if you have one of these machines.
5696a48565eSIngo Molnar
570c5c606d9SRavikiran G Thirumalaiconfig X86_UV
571c5c606d9SRavikiran G Thirumalai	bool "SGI Ultraviolet"
572c5c606d9SRavikiran G Thirumalai	depends on X86_64
573c5c606d9SRavikiran G Thirumalai	depends on X86_EXTENDED_PLATFORM
57454c28d29SJack Steiner	depends on NUMA
5751ecb4ae5SAndrew Morton	depends on EFI
576c2209ea5SIngo Molnar	depends on KEXEC_CORE
5779d6c26e7SSuresh Siddha	depends on X86_X2APIC
5781222e564SIngo Molnar	depends on PCI
579a7f7f624SMasahiro Yamada	help
580c5c606d9SRavikiran G Thirumalai	  This option is needed in order to support SGI Ultraviolet systems.
581c5c606d9SRavikiran G Thirumalai	  If you don't have one of these, you should say N here.
582c5c606d9SRavikiran G Thirumalai
583c5c606d9SRavikiran G Thirumalai# Following is an alphabetically sorted list of 32 bit extended platforms
584c5c606d9SRavikiran G Thirumalai# Please maintain the alphabetic order if and when there are additions
585506f1d07SSam Ravnborg
586ddd70cf9SJun Nakajimaconfig X86_GOLDFISH
587ddd70cf9SJun Nakajima	bool "Goldfish (Virtual Platform)"
588cb7b8023SBen Hutchings	depends on X86_EXTENDED_PLATFORM
589a7f7f624SMasahiro Yamada	help
590ddd70cf9SJun Nakajima	 Enable support for the Goldfish virtual platform used primarily
591ddd70cf9SJun Nakajima	 for Android development. Unless you are building for the Android
592ddd70cf9SJun Nakajima	 Goldfish emulator say N here.
593ddd70cf9SJun Nakajima
594c751e17bSThomas Gleixnerconfig X86_INTEL_CE
595c751e17bSThomas Gleixner	bool "CE4100 TV platform"
596c751e17bSThomas Gleixner	depends on PCI
597c751e17bSThomas Gleixner	depends on PCI_GODIRECT
5986084a6e2SJiang Liu	depends on X86_IO_APIC
599c751e17bSThomas Gleixner	depends on X86_32
600c751e17bSThomas Gleixner	depends on X86_EXTENDED_PLATFORM
60137bc9f50SDirk Brandewie	select X86_REBOOTFIXUPS
602da6b737bSSebastian Andrzej Siewior	select OF
603da6b737bSSebastian Andrzej Siewior	select OF_EARLY_FLATTREE
604a7f7f624SMasahiro Yamada	help
605c751e17bSThomas Gleixner	  Select for the Intel CE media processor (CE4100) SOC.
606c751e17bSThomas Gleixner	  This option compiles in support for the CE4100 SOC for settop
607c751e17bSThomas Gleixner	  boxes and media devices.
608c751e17bSThomas Gleixner
6094cb9b00fSDavid Cohenconfig X86_INTEL_MID
61043605ef1SAlan Cox	bool "Intel MID platform support"
61143605ef1SAlan Cox	depends on X86_EXTENDED_PLATFORM
612edc6bc78SDavid Cohen	depends on X86_PLATFORM_DEVICES
6131ea7c673SAlan Cox	depends on PCI
6143fda5bb4SAndy Shevchenko	depends on X86_64 || (PCI_GOANY && X86_32)
6151ea7c673SAlan Cox	depends on X86_IO_APIC
6164cb9b00fSDavid Cohen	select I2C
6177c9c3a1eSAlan Cox	select DW_APB_TIMER
61854b34aa0SMika Westerberg	select INTEL_SCU_PCI
619a7f7f624SMasahiro Yamada	help
6204cb9b00fSDavid Cohen	  Select to build a kernel capable of supporting Intel MID (Mobile
6214cb9b00fSDavid Cohen	  Internet Device) platform systems which do not have the PCI legacy
6224cb9b00fSDavid Cohen	  interfaces. If you are building for a PC class system say N here.
6231ea7c673SAlan Cox
6244cb9b00fSDavid Cohen	  Intel MID platforms are based on an Intel processor and chipset which
6254cb9b00fSDavid Cohen	  consume less power than most of the x86 derivatives.
62643605ef1SAlan Cox
6278bbc2a13SBryan O'Donoghueconfig X86_INTEL_QUARK
6288bbc2a13SBryan O'Donoghue	bool "Intel Quark platform support"
6298bbc2a13SBryan O'Donoghue	depends on X86_32
6308bbc2a13SBryan O'Donoghue	depends on X86_EXTENDED_PLATFORM
6318bbc2a13SBryan O'Donoghue	depends on X86_PLATFORM_DEVICES
6328bbc2a13SBryan O'Donoghue	depends on X86_TSC
6338bbc2a13SBryan O'Donoghue	depends on PCI
6348bbc2a13SBryan O'Donoghue	depends on PCI_GOANY
6358bbc2a13SBryan O'Donoghue	depends on X86_IO_APIC
6368bbc2a13SBryan O'Donoghue	select IOSF_MBI
6378bbc2a13SBryan O'Donoghue	select INTEL_IMR
6389ab6eb51SAndy Shevchenko	select COMMON_CLK
639a7f7f624SMasahiro Yamada	help
6408bbc2a13SBryan O'Donoghue	  Select to include support for Quark X1000 SoC.
6418bbc2a13SBryan O'Donoghue	  Say Y here if you have a Quark based system such as the Arduino
6428bbc2a13SBryan O'Donoghue	  compatible Intel Galileo.
6438bbc2a13SBryan O'Donoghue
6443d48aab1SMika Westerbergconfig X86_INTEL_LPSS
6453d48aab1SMika Westerberg	bool "Intel Low Power Subsystem Support"
6465962dd22SSinan Kaya	depends on X86 && ACPI && PCI
6473d48aab1SMika Westerberg	select COMMON_CLK
6480f531431SMathias Nyman	select PINCTRL
649eebb3e8dSAndy Shevchenko	select IOSF_MBI
650a7f7f624SMasahiro Yamada	help
6513d48aab1SMika Westerberg	  Select to build support for Intel Low Power Subsystem such as
6523d48aab1SMika Westerberg	  found on Intel Lynxpoint PCH. Selecting this option enables
6530f531431SMathias Nyman	  things like clock tree (common clock framework) and pincontrol
6540f531431SMathias Nyman	  which are needed by the LPSS peripheral drivers.
6553d48aab1SMika Westerberg
65692082a88SKen Xueconfig X86_AMD_PLATFORM_DEVICE
65792082a88SKen Xue	bool "AMD ACPI2Platform devices support"
65892082a88SKen Xue	depends on ACPI
65992082a88SKen Xue	select COMMON_CLK
66092082a88SKen Xue	select PINCTRL
661a7f7f624SMasahiro Yamada	help
66292082a88SKen Xue	  Select to interpret AMD specific ACPI device to platform device
66392082a88SKen Xue	  such as I2C, UART, GPIO found on AMD Carrizo and later chipsets.
66492082a88SKen Xue	  I2C and UART depend on COMMON_CLK to set clock. GPIO driver is
66592082a88SKen Xue	  implemented under PINCTRL subsystem.
66692082a88SKen Xue
667ced3ce76SDavid E. Boxconfig IOSF_MBI
668ced3ce76SDavid E. Box	tristate "Intel SoC IOSF Sideband support for SoC platforms"
669ced3ce76SDavid E. Box	depends on PCI
670a7f7f624SMasahiro Yamada	help
671ced3ce76SDavid E. Box	  This option enables sideband register access support for Intel SoC
672ced3ce76SDavid E. Box	  platforms. On these platforms the IOSF sideband is used in lieu of
673ced3ce76SDavid E. Box	  MSR's for some register accesses, mostly but not limited to thermal
674ced3ce76SDavid E. Box	  and power. Drivers may query the availability of this device to
675ced3ce76SDavid E. Box	  determine if they need the sideband in order to work on these
676ced3ce76SDavid E. Box	  platforms. The sideband is available on the following SoC products.
677ced3ce76SDavid E. Box	  This list is not meant to be exclusive.
678ced3ce76SDavid E. Box	   - BayTrail
679ced3ce76SDavid E. Box	   - Braswell
680ced3ce76SDavid E. Box	   - Quark
681ced3ce76SDavid E. Box
682ced3ce76SDavid E. Box	  You should say Y if you are running a kernel on one of these SoC's.
683ced3ce76SDavid E. Box
684ed2226bdSDavid E. Boxconfig IOSF_MBI_DEBUG
685ed2226bdSDavid E. Box	bool "Enable IOSF sideband access through debugfs"
686ed2226bdSDavid E. Box	depends on IOSF_MBI && DEBUG_FS
687a7f7f624SMasahiro Yamada	help
688ed2226bdSDavid E. Box	  Select this option to expose the IOSF sideband access registers (MCR,
689ed2226bdSDavid E. Box	  MDR, MCRX) through debugfs to write and read register information from
690ed2226bdSDavid E. Box	  different units on the SoC. This is most useful for obtaining device
691ed2226bdSDavid E. Box	  state information for debug and analysis. As this is a general access
692ed2226bdSDavid E. Box	  mechanism, users of this option would have specific knowledge of the
693ed2226bdSDavid E. Box	  device they want to access.
694ed2226bdSDavid E. Box
695ed2226bdSDavid E. Box	  If you don't require the option or are in doubt, say N.
696ed2226bdSDavid E. Box
697c5c606d9SRavikiran G Thirumalaiconfig X86_RDC321X
698c5c606d9SRavikiran G Thirumalai	bool "RDC R-321x SoC"
699506f1d07SSam Ravnborg	depends on X86_32
700c5c606d9SRavikiran G Thirumalai	depends on X86_EXTENDED_PLATFORM
701c5c606d9SRavikiran G Thirumalai	select M486
702c5c606d9SRavikiran G Thirumalai	select X86_REBOOTFIXUPS
703a7f7f624SMasahiro Yamada	help
704c5c606d9SRavikiran G Thirumalai	  This option is needed for RDC R-321x system-on-chip, also known
705c5c606d9SRavikiran G Thirumalai	  as R-8610-(G).
706c5c606d9SRavikiran G Thirumalai	  If you don't have one of these chips, you should say N here.
707c5c606d9SRavikiran G Thirumalai
708e0c7ae37SIngo Molnarconfig X86_32_NON_STANDARD
7099c398017SIngo Molnar	bool "Support non-standard 32-bit SMP architectures"
7109c398017SIngo Molnar	depends on X86_32 && SMP
711c5c606d9SRavikiran G Thirumalai	depends on X86_EXTENDED_PLATFORM
712a7f7f624SMasahiro Yamada	help
713b5660ba7SH. Peter Anvin	  This option compiles in the bigsmp and STA2X11 default
714b5660ba7SH. Peter Anvin	  subarchitectures.  It is intended for a generic binary
715b5660ba7SH. Peter Anvin	  kernel. If you select them all, kernel will probe it one by
716b5660ba7SH. Peter Anvin	  one and will fallback to default.
717d49c4288SYinghai Lu
718c5c606d9SRavikiran G Thirumalai# Alphabetically sorted list of Non standard 32 bit platforms
719d49c4288SYinghai Lu
720d949f36fSLinus Torvaldsconfig X86_SUPPORTS_MEMORY_FAILURE
7216fc108a0SJan Beulich	def_bool y
722d949f36fSLinus Torvalds	# MCE code calls memory_failure():
723d949f36fSLinus Torvalds	depends on X86_MCE
724d949f36fSLinus Torvalds	# On 32-bit this adds too big of NODES_SHIFT and we run out of page flags:
725d949f36fSLinus Torvalds	# On 32-bit SPARSEMEM adds too big of SECTIONS_WIDTH:
726d949f36fSLinus Torvalds	depends on X86_64 || !SPARSEMEM
727d949f36fSLinus Torvalds	select ARCH_SUPPORTS_MEMORY_FAILURE
728d949f36fSLinus Torvalds
72983125a3aSAlessandro Rubiniconfig STA2X11
73083125a3aSAlessandro Rubini	bool "STA2X11 Companion Chip Support"
73183125a3aSAlessandro Rubini	depends on X86_32_NON_STANDARD && PCI
73283125a3aSAlessandro Rubini	select SWIOTLB
73383125a3aSAlessandro Rubini	select MFD_STA2X11
7340145071bSLinus Walleij	select GPIOLIB
735a7f7f624SMasahiro Yamada	help
73683125a3aSAlessandro Rubini	  This adds support for boards based on the STA2X11 IO-Hub,
73783125a3aSAlessandro Rubini	  a.k.a. "ConneXt". The chip is used in place of the standard
73883125a3aSAlessandro Rubini	  PC chipset, so all "standard" peripherals are missing. If this
73983125a3aSAlessandro Rubini	  option is selected the kernel will still be able to boot on
74083125a3aSAlessandro Rubini	  standard PC machines.
74183125a3aSAlessandro Rubini
74282148d1dSShérabconfig X86_32_IRIS
74382148d1dSShérab	tristate "Eurobraille/Iris poweroff module"
74482148d1dSShérab	depends on X86_32
745a7f7f624SMasahiro Yamada	help
74682148d1dSShérab	  The Iris machines from EuroBraille do not have APM or ACPI support
74782148d1dSShérab	  to shut themselves down properly.  A special I/O sequence is
74882148d1dSShérab	  needed to do so, which is what this module does at
74982148d1dSShérab	  kernel shutdown.
75082148d1dSShérab
75182148d1dSShérab	  This is only for Iris machines from EuroBraille.
75282148d1dSShérab
75382148d1dSShérab	  If unused, say N.
75482148d1dSShérab
755ae1e9130SIngo Molnarconfig SCHED_OMIT_FRAME_POINTER
7563c2362e6SHarvey Harrison	def_bool y
7573c2362e6SHarvey Harrison	prompt "Single-depth WCHAN output"
758a87d0914SKen Chen	depends on X86
759a7f7f624SMasahiro Yamada	help
760506f1d07SSam Ravnborg	  Calculate simpler /proc/<PID>/wchan values. If this option
761506f1d07SSam Ravnborg	  is disabled then wchan values will recurse back to the
762506f1d07SSam Ravnborg	  caller function. This provides more accurate wchan values,
763506f1d07SSam Ravnborg	  at the expense of slightly more scheduling overhead.
764506f1d07SSam Ravnborg
765506f1d07SSam Ravnborg	  If in doubt, say "Y".
766506f1d07SSam Ravnborg
7676276a074SBorislav Petkovmenuconfig HYPERVISOR_GUEST
7686276a074SBorislav Petkov	bool "Linux guest support"
769a7f7f624SMasahiro Yamada	help
7706276a074SBorislav Petkov	  Say Y here to enable options for running Linux under various hyper-
7716276a074SBorislav Petkov	  visors. This option enables basic hypervisor detection and platform
7726276a074SBorislav Petkov	  setup.
773506f1d07SSam Ravnborg
7746276a074SBorislav Petkov	  If you say N, all options in this submenu will be skipped and
7756276a074SBorislav Petkov	  disabled, and Linux guest support won't be built in.
776506f1d07SSam Ravnborg
7776276a074SBorislav Petkovif HYPERVISOR_GUEST
778506f1d07SSam Ravnborg
779e61bd94aSEduardo Pereira Habkostconfig PARAVIRT
780e61bd94aSEduardo Pereira Habkost	bool "Enable paravirtualization code"
781a0e2bf7cSJuergen Gross	depends on HAVE_STATIC_CALL
782a7f7f624SMasahiro Yamada	help
783e61bd94aSEduardo Pereira Habkost	  This changes the kernel so it can modify itself when it is run
784e61bd94aSEduardo Pereira Habkost	  under a hypervisor, potentially improving performance significantly
785e61bd94aSEduardo Pereira Habkost	  over full virtualization.  However, when run without a hypervisor
786e61bd94aSEduardo Pereira Habkost	  the kernel is theoretically slower and slightly larger.
787e61bd94aSEduardo Pereira Habkost
788c00a280aSJuergen Grossconfig PARAVIRT_XXL
789c00a280aSJuergen Gross	bool
790c00a280aSJuergen Gross
7916276a074SBorislav Petkovconfig PARAVIRT_DEBUG
7926276a074SBorislav Petkov	bool "paravirt-ops debugging"
7936276a074SBorislav Petkov	depends on PARAVIRT && DEBUG_KERNEL
794a7f7f624SMasahiro Yamada	help
7956276a074SBorislav Petkov	  Enable to debug paravirt_ops internals.  Specifically, BUG if
7966276a074SBorislav Petkov	  a paravirt_op is missing when it is called.
7976276a074SBorislav Petkov
798b4ecc126SJeremy Fitzhardingeconfig PARAVIRT_SPINLOCKS
799b4ecc126SJeremy Fitzhardinge	bool "Paravirtualization layer for spinlocks"
8006ea30386SKees Cook	depends on PARAVIRT && SMP
801a7f7f624SMasahiro Yamada	help
802b4ecc126SJeremy Fitzhardinge	  Paravirtualized spinlocks allow a pvops backend to replace the
803b4ecc126SJeremy Fitzhardinge	  spinlock implementation with something virtualization-friendly
804b4ecc126SJeremy Fitzhardinge	  (for example, block the virtual CPU rather than spinning).
805b4ecc126SJeremy Fitzhardinge
8064c4e4f61SRaghavendra K T	  It has a minimal impact on native kernels and gives a nice performance
8074c4e4f61SRaghavendra K T	  benefit on paravirtualized KVM / Xen kernels.
808b4ecc126SJeremy Fitzhardinge
8094c4e4f61SRaghavendra K T	  If you are unsure how to answer this question, answer Y.
810b4ecc126SJeremy Fitzhardinge
811ecca2502SZhao Yakuiconfig X86_HV_CALLBACK_VECTOR
812ecca2502SZhao Yakui	def_bool n
813ecca2502SZhao Yakui
8146276a074SBorislav Petkovsource "arch/x86/xen/Kconfig"
8156276a074SBorislav Petkov
8166276a074SBorislav Petkovconfig KVM_GUEST
8176276a074SBorislav Petkov	bool "KVM Guest support (including kvmclock)"
8186276a074SBorislav Petkov	depends on PARAVIRT
8196276a074SBorislav Petkov	select PARAVIRT_CLOCK
820a1c4423bSMarcelo Tosatti	select ARCH_CPUIDLE_HALTPOLL
821b1d40575SVitaly Kuznetsov	select X86_HV_CALLBACK_VECTOR
8226276a074SBorislav Petkov	default y
823a7f7f624SMasahiro Yamada	help
8246276a074SBorislav Petkov	  This option enables various optimizations for running under the KVM
8256276a074SBorislav Petkov	  hypervisor. It includes a paravirtualized clock, so that instead
8266276a074SBorislav Petkov	  of relying on a PIT (or probably other) emulation by the
8276276a074SBorislav Petkov	  underlying device model, the host provides the guest with
8286276a074SBorislav Petkov	  timing infrastructure such as time of day, and system time
8296276a074SBorislav Petkov
830a1c4423bSMarcelo Tosatticonfig ARCH_CPUIDLE_HALTPOLL
831a1c4423bSMarcelo Tosatti	def_bool n
832a1c4423bSMarcelo Tosatti	prompt "Disable host haltpoll when loading haltpoll driver"
833a1c4423bSMarcelo Tosatti	help
834a1c4423bSMarcelo Tosatti	  If virtualized under KVM, disable host haltpoll.
835a1c4423bSMarcelo Tosatti
8367733607fSMaran Wilsonconfig PVH
8377733607fSMaran Wilson	bool "Support for running PVH guests"
838a7f7f624SMasahiro Yamada	help
8397733607fSMaran Wilson	  This option enables the PVH entry point for guest virtual machines
8407733607fSMaran Wilson	  as specified in the x86/HVM direct boot ABI.
8417733607fSMaran Wilson
8426276a074SBorislav Petkovconfig PARAVIRT_TIME_ACCOUNTING
8436276a074SBorislav Petkov	bool "Paravirtual steal time accounting"
8446276a074SBorislav Petkov	depends on PARAVIRT
845a7f7f624SMasahiro Yamada	help
8466276a074SBorislav Petkov	  Select this option to enable fine granularity task steal time
8476276a074SBorislav Petkov	  accounting. Time spent executing other tasks in parallel with
8486276a074SBorislav Petkov	  the current vCPU is discounted from the vCPU power. To account for
8496276a074SBorislav Petkov	  that, there can be a small performance impact.
8506276a074SBorislav Petkov
8516276a074SBorislav Petkov	  If in doubt, say N here.
8526276a074SBorislav Petkov
8537af192c9SGerd Hoffmannconfig PARAVIRT_CLOCK
8547af192c9SGerd Hoffmann	bool
8557af192c9SGerd Hoffmann
8564a362601SJan Kiszkaconfig JAILHOUSE_GUEST
8574a362601SJan Kiszka	bool "Jailhouse non-root cell support"
858abde587bSArnd Bergmann	depends on X86_64 && PCI
85987e65d05SJan Kiszka	select X86_PM_TIMER
860a7f7f624SMasahiro Yamada	help
8614a362601SJan Kiszka	  This option allows to run Linux as guest in a Jailhouse non-root
8624a362601SJan Kiszka	  cell. You can leave this option disabled if you only want to start
8634a362601SJan Kiszka	  Jailhouse and run Linux afterwards in the root cell.
8644a362601SJan Kiszka
865ec7972c9SZhao Yakuiconfig ACRN_GUEST
866ec7972c9SZhao Yakui	bool "ACRN Guest support"
867ec7972c9SZhao Yakui	depends on X86_64
868498ad393SZhao Yakui	select X86_HV_CALLBACK_VECTOR
869ec7972c9SZhao Yakui	help
870ec7972c9SZhao Yakui	  This option allows to run Linux as guest in the ACRN hypervisor. ACRN is
871ec7972c9SZhao Yakui	  a flexible, lightweight reference open-source hypervisor, built with
872ec7972c9SZhao Yakui	  real-time and safety-criticality in mind. It is built for embedded
873ec7972c9SZhao Yakui	  IOT with small footprint and real-time features. More details can be
874ec7972c9SZhao Yakui	  found in https://projectacrn.org/.
875ec7972c9SZhao Yakui
8766276a074SBorislav Petkovendif #HYPERVISOR_GUEST
87797349135SJeremy Fitzhardinge
878506f1d07SSam Ravnborgsource "arch/x86/Kconfig.cpu"
879506f1d07SSam Ravnborg
880506f1d07SSam Ravnborgconfig HPET_TIMER
8813c2362e6SHarvey Harrison	def_bool X86_64
882506f1d07SSam Ravnborg	prompt "HPET Timer Support" if X86_32
883a7f7f624SMasahiro Yamada	help
884506f1d07SSam Ravnborg	  Use the IA-PC HPET (High Precision Event Timer) to manage
885506f1d07SSam Ravnborg	  time in preference to the PIT and RTC, if a HPET is
886506f1d07SSam Ravnborg	  present.
887506f1d07SSam Ravnborg	  HPET is the next generation timer replacing legacy 8254s.
888506f1d07SSam Ravnborg	  The HPET provides a stable time base on SMP
889506f1d07SSam Ravnborg	  systems, unlike the TSC, but it is more expensive to access,
8904e7f9df2SMichael S. Tsirkin	  as it is off-chip.  The interface used is documented
8914e7f9df2SMichael S. Tsirkin	  in the HPET spec, revision 1.
892506f1d07SSam Ravnborg
893506f1d07SSam Ravnborg	  You can safely choose Y here.  However, HPET will only be
894506f1d07SSam Ravnborg	  activated if the platform and the BIOS support this feature.
895506f1d07SSam Ravnborg	  Otherwise the 8254 will be used for timing services.
896506f1d07SSam Ravnborg
897506f1d07SSam Ravnborg	  Choose N to continue using the legacy 8254 timer.
898506f1d07SSam Ravnborg
899506f1d07SSam Ravnborgconfig HPET_EMULATE_RTC
9003c2362e6SHarvey Harrison	def_bool y
9013228e1dcSAnand K Mistry	depends on HPET_TIMER && (RTC_DRV_CMOS=m || RTC_DRV_CMOS=y)
902506f1d07SSam Ravnborg
9036a108a14SDavid Rientjes# Mark as expert because too many people got it wrong.
904506f1d07SSam Ravnborg# The code disables itself when not needed.
9057ae9392cSThomas Petazzoniconfig DMI
9067ae9392cSThomas Petazzoni	default y
907cf074402SArd Biesheuvel	select DMI_SCAN_MACHINE_NON_EFI_FALLBACK
9086a108a14SDavid Rientjes	bool "Enable DMI scanning" if EXPERT
909a7f7f624SMasahiro Yamada	help
9107ae9392cSThomas Petazzoni	  Enabled scanning of DMI to identify machine quirks. Say Y
9117ae9392cSThomas Petazzoni	  here unless you have verified that your setup is not
9127ae9392cSThomas Petazzoni	  affected by entries in the DMI blacklist. Required by PNP
9137ae9392cSThomas Petazzoni	  BIOS code.
9147ae9392cSThomas Petazzoni
915506f1d07SSam Ravnborgconfig GART_IOMMU
91638901f1cSAndi Kleen	bool "Old AMD GART IOMMU support"
9172f9237d4SChristoph Hellwig	select DMA_OPS
918a4ce5a48SChristoph Hellwig	select IOMMU_HELPER
919506f1d07SSam Ravnborg	select SWIOTLB
92023ac4ae8SAndreas Herrmann	depends on X86_64 && PCI && AMD_NB
921a7f7f624SMasahiro Yamada	help
922ced3c42cSIngo Molnar	  Provides a driver for older AMD Athlon64/Opteron/Turion/Sempron
923ced3c42cSIngo Molnar	  GART based hardware IOMMUs.
924ced3c42cSIngo Molnar
925ced3c42cSIngo Molnar	  The GART supports full DMA access for devices with 32-bit access
926ced3c42cSIngo Molnar	  limitations, on systems with more than 3 GB. This is usually needed
927ced3c42cSIngo Molnar	  for USB, sound, many IDE/SATA chipsets and some other devices.
928ced3c42cSIngo Molnar
929ced3c42cSIngo Molnar	  Newer systems typically have a modern AMD IOMMU, supported via
930ced3c42cSIngo Molnar	  the CONFIG_AMD_IOMMU=y config option.
931ced3c42cSIngo Molnar
932ced3c42cSIngo Molnar	  In normal configurations this driver is only active when needed:
933ced3c42cSIngo Molnar	  there's more than 3 GB of memory and the system contains a
934ced3c42cSIngo Molnar	  32-bit limited device.
935ced3c42cSIngo Molnar
936ced3c42cSIngo Molnar	  If unsure, say Y.
937506f1d07SSam Ravnborg
9381184dc2fSMike Travisconfig MAXSMP
939ddb0c5a6SSamuel Thibault	bool "Enable Maximum number of SMP Processors and NUMA Nodes"
9406ea30386SKees Cook	depends on X86_64 && SMP && DEBUG_KERNEL
94136f5101aSMike Travis	select CPUMASK_OFFSTACK
942a7f7f624SMasahiro Yamada	help
943ddb0c5a6SSamuel Thibault	  Enable maximum number of CPUS and NUMA Nodes for this architecture.
9441184dc2fSMike Travis	  If unsure, say N.
945506f1d07SSam Ravnborg
946aec6487eSIngo Molnar#
947aec6487eSIngo Molnar# The maximum number of CPUs supported:
948aec6487eSIngo Molnar#
949aec6487eSIngo Molnar# The main config value is NR_CPUS, which defaults to NR_CPUS_DEFAULT,
950aec6487eSIngo Molnar# and which can be configured interactively in the
951aec6487eSIngo Molnar# [NR_CPUS_RANGE_BEGIN ... NR_CPUS_RANGE_END] range.
952aec6487eSIngo Molnar#
953aec6487eSIngo Molnar# The ranges are different on 32-bit and 64-bit kernels, depending on
954aec6487eSIngo Molnar# hardware capabilities and scalability features of the kernel.
955aec6487eSIngo Molnar#
956aec6487eSIngo Molnar# ( If MAXSMP is enabled we just use the highest possible value and disable
957aec6487eSIngo Molnar#   interactive configuration. )
958aec6487eSIngo Molnar#
959a0d0bb4dSRandy Dunlap
960aec6487eSIngo Molnarconfig NR_CPUS_RANGE_BEGIN
961a0d0bb4dSRandy Dunlap	int
962aec6487eSIngo Molnar	default NR_CPUS_RANGE_END if MAXSMP
963a0d0bb4dSRandy Dunlap	default    1 if !SMP
964a0d0bb4dSRandy Dunlap	default    2
965a0d0bb4dSRandy Dunlap
966aec6487eSIngo Molnarconfig NR_CPUS_RANGE_END
967a0d0bb4dSRandy Dunlap	int
968a0d0bb4dSRandy Dunlap	depends on X86_32
969aec6487eSIngo Molnar	default   64 if  SMP &&  X86_BIGSMP
970aec6487eSIngo Molnar	default    8 if  SMP && !X86_BIGSMP
971a0d0bb4dSRandy Dunlap	default    1 if !SMP
972a0d0bb4dSRandy Dunlap
973aec6487eSIngo Molnarconfig NR_CPUS_RANGE_END
974a0d0bb4dSRandy Dunlap	int
975a0d0bb4dSRandy Dunlap	depends on X86_64
9761edae1aeSScott Wood	default 8192 if  SMP && CPUMASK_OFFSTACK
9771edae1aeSScott Wood	default  512 if  SMP && !CPUMASK_OFFSTACK
978a0d0bb4dSRandy Dunlap	default    1 if !SMP
979aec6487eSIngo Molnar
980aec6487eSIngo Molnarconfig NR_CPUS_DEFAULT
981aec6487eSIngo Molnar	int
982aec6487eSIngo Molnar	depends on X86_32
983aec6487eSIngo Molnar	default   32 if  X86_BIGSMP
984aec6487eSIngo Molnar	default    8 if  SMP
985aec6487eSIngo Molnar	default    1 if !SMP
986aec6487eSIngo Molnar
987aec6487eSIngo Molnarconfig NR_CPUS_DEFAULT
988aec6487eSIngo Molnar	int
989aec6487eSIngo Molnar	depends on X86_64
990a0d0bb4dSRandy Dunlap	default 8192 if  MAXSMP
991a0d0bb4dSRandy Dunlap	default   64 if  SMP
992aec6487eSIngo Molnar	default    1 if !SMP
993a0d0bb4dSRandy Dunlap
994506f1d07SSam Ravnborgconfig NR_CPUS
99536f5101aSMike Travis	int "Maximum number of CPUs" if SMP && !MAXSMP
996aec6487eSIngo Molnar	range NR_CPUS_RANGE_BEGIN NR_CPUS_RANGE_END
997aec6487eSIngo Molnar	default NR_CPUS_DEFAULT
998a7f7f624SMasahiro Yamada	help
999506f1d07SSam Ravnborg	  This allows you to specify the maximum number of CPUs which this
1000bb61ccc7SJosh Boyer	  kernel will support.  If CPUMASK_OFFSTACK is enabled, the maximum
1001cad14bb9SKirill A. Shutemov	  supported value is 8192, otherwise the maximum value is 512.  The
1002506f1d07SSam Ravnborg	  minimum value which makes sense is 2.
1003506f1d07SSam Ravnborg
1004aec6487eSIngo Molnar	  This is purely to save memory: each supported CPU adds about 8KB
1005aec6487eSIngo Molnar	  to the kernel image.
1006506f1d07SSam Ravnborg
100766558b73STim Chenconfig SCHED_CLUSTER
100866558b73STim Chen	bool "Cluster scheduler support"
100966558b73STim Chen	depends on SMP
101066558b73STim Chen	default y
101166558b73STim Chen	help
101266558b73STim Chen	  Cluster scheduler support improves the CPU scheduler's decision
101366558b73STim Chen	  making when dealing with machines that have clusters of CPUs.
101466558b73STim Chen	  Cluster usually means a couple of CPUs which are placed closely
101566558b73STim Chen	  by sharing mid-level caches, last-level cache tags or internal
101666558b73STim Chen	  busses.
101766558b73STim Chen
1018506f1d07SSam Ravnborgconfig SCHED_SMT
1019dbe73364SThomas Gleixner	def_bool y if SMP
1020506f1d07SSam Ravnborg
1021506f1d07SSam Ravnborgconfig SCHED_MC
10223c2362e6SHarvey Harrison	def_bool y
10233c2362e6SHarvey Harrison	prompt "Multi-core scheduler support"
1024c8e56d20SBorislav Petkov	depends on SMP
1025a7f7f624SMasahiro Yamada	help
1026506f1d07SSam Ravnborg	  Multi-core scheduler support improves the CPU scheduler's decision
1027506f1d07SSam Ravnborg	  making when dealing with multi-core CPU chips at a cost of slightly
1028506f1d07SSam Ravnborg	  increased overhead in some places. If unsure say N here.
1029506f1d07SSam Ravnborg
1030de966cf4STim Chenconfig SCHED_MC_PRIO
1031de966cf4STim Chen	bool "CPU core priorities scheduler support"
10320a21fc12SIngo Molnar	depends on SCHED_MC && CPU_SUP_INTEL
10330a21fc12SIngo Molnar	select X86_INTEL_PSTATE
10340a21fc12SIngo Molnar	select CPU_FREQ
1035de966cf4STim Chen	default y
1036a7f7f624SMasahiro Yamada	help
1037de966cf4STim Chen	  Intel Turbo Boost Max Technology 3.0 enabled CPUs have a
1038de966cf4STim Chen	  core ordering determined at manufacturing time, which allows
1039de966cf4STim Chen	  certain cores to reach higher turbo frequencies (when running
1040de966cf4STim Chen	  single threaded workloads) than others.
1041de966cf4STim Chen
1042de966cf4STim Chen	  Enabling this kernel feature teaches the scheduler about
1043de966cf4STim Chen	  the TBM3 (aka ITMT) priority order of the CPU cores and adjusts the
1044de966cf4STim Chen	  scheduler's CPU selection logic accordingly, so that higher
1045de966cf4STim Chen	  overall system performance can be achieved.
1046de966cf4STim Chen
1047de966cf4STim Chen	  This feature will have no effect on CPUs without this feature.
1048de966cf4STim Chen
1049de966cf4STim Chen	  If unsure say Y here.
10505e76b2abSTim Chen
105130b8b006SThomas Gleixnerconfig UP_LATE_INIT
105230b8b006SThomas Gleixner	def_bool y
1053ba360f88SThomas Gleixner	depends on !SMP && X86_LOCAL_APIC
105430b8b006SThomas Gleixner
1055506f1d07SSam Ravnborgconfig X86_UP_APIC
105650849eefSJan Beulich	bool "Local APIC support on uniprocessors" if !PCI_MSI
105750849eefSJan Beulich	default PCI_MSI
105838a1dfdaSBryan O'Donoghue	depends on X86_32 && !SMP && !X86_32_NON_STANDARD
1059a7f7f624SMasahiro Yamada	help
1060506f1d07SSam Ravnborg	  A local APIC (Advanced Programmable Interrupt Controller) is an
1061506f1d07SSam Ravnborg	  integrated interrupt controller in the CPU. If you have a single-CPU
1062506f1d07SSam Ravnborg	  system which has a processor with a local APIC, you can say Y here to
1063506f1d07SSam Ravnborg	  enable and use it. If you say Y here even though your machine doesn't
1064506f1d07SSam Ravnborg	  have a local APIC, then the kernel will still run with no slowdown at
1065506f1d07SSam Ravnborg	  all. The local APIC supports CPU-generated self-interrupts (timer,
1066506f1d07SSam Ravnborg	  performance counters), and the NMI watchdog which detects hard
1067506f1d07SSam Ravnborg	  lockups.
1068506f1d07SSam Ravnborg
1069506f1d07SSam Ravnborgconfig X86_UP_IOAPIC
1070506f1d07SSam Ravnborg	bool "IO-APIC support on uniprocessors"
1071506f1d07SSam Ravnborg	depends on X86_UP_APIC
1072a7f7f624SMasahiro Yamada	help
1073506f1d07SSam Ravnborg	  An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an
1074506f1d07SSam Ravnborg	  SMP-capable replacement for PC-style interrupt controllers. Most
1075506f1d07SSam Ravnborg	  SMP systems and many recent uniprocessor systems have one.
1076506f1d07SSam Ravnborg
1077506f1d07SSam Ravnborg	  If you have a single-CPU system with an IO-APIC, you can say Y here
1078506f1d07SSam Ravnborg	  to use it. If you say Y here even though your machine doesn't have
1079506f1d07SSam Ravnborg	  an IO-APIC, then the kernel will still run with no slowdown at all.
1080506f1d07SSam Ravnborg
1081506f1d07SSam Ravnborgconfig X86_LOCAL_APIC
10823c2362e6SHarvey Harrison	def_bool y
10830dbc6078SThomas Petazzoni	depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC || PCI_MSI
1084b5dc8e6cSJiang Liu	select IRQ_DOMAIN_HIERARCHY
108552f518a3SJiang Liu	select PCI_MSI_IRQ_DOMAIN if PCI_MSI
1086506f1d07SSam Ravnborg
1087506f1d07SSam Ravnborgconfig X86_IO_APIC
1088b1da1e71SJan Beulich	def_bool y
1089b1da1e71SJan Beulich	depends on X86_LOCAL_APIC || X86_UP_IOAPIC
1090506f1d07SSam Ravnborg
109141b9eb26SStefan Assmannconfig X86_REROUTE_FOR_BROKEN_BOOT_IRQS
109241b9eb26SStefan Assmann	bool "Reroute for broken boot IRQs"
109341b9eb26SStefan Assmann	depends on X86_IO_APIC
1094a7f7f624SMasahiro Yamada	help
109541b9eb26SStefan Assmann	  This option enables a workaround that fixes a source of
109641b9eb26SStefan Assmann	  spurious interrupts. This is recommended when threaded
109741b9eb26SStefan Assmann	  interrupt handling is used on systems where the generation of
109841b9eb26SStefan Assmann	  superfluous "boot interrupts" cannot be disabled.
109941b9eb26SStefan Assmann
110041b9eb26SStefan Assmann	  Some chipsets generate a legacy INTx "boot IRQ" when the IRQ
110141b9eb26SStefan Assmann	  entry in the chipset's IO-APIC is masked (as, e.g. the RT
110241b9eb26SStefan Assmann	  kernel does during interrupt handling). On chipsets where this
110341b9eb26SStefan Assmann	  boot IRQ generation cannot be disabled, this workaround keeps
110441b9eb26SStefan Assmann	  the original IRQ line masked so that only the equivalent "boot
110541b9eb26SStefan Assmann	  IRQ" is delivered to the CPUs. The workaround also tells the
110641b9eb26SStefan Assmann	  kernel to set up the IRQ handler on the boot IRQ line. In this
110741b9eb26SStefan Assmann	  way only one interrupt is delivered to the kernel. Otherwise
110841b9eb26SStefan Assmann	  the spurious second interrupt may cause the kernel to bring
110941b9eb26SStefan Assmann	  down (vital) interrupt lines.
111041b9eb26SStefan Assmann
111141b9eb26SStefan Assmann	  Only affects "broken" chipsets. Interrupt sharing may be
111241b9eb26SStefan Assmann	  increased on these systems.
111341b9eb26SStefan Assmann
1114506f1d07SSam Ravnborgconfig X86_MCE
1115bab9bc65SAndi Kleen	bool "Machine Check / overheating reporting"
1116648ed940SChen, Gong	select GENERIC_ALLOCATOR
1117e57dbaf7SBorislav Petkov	default y
1118a7f7f624SMasahiro Yamada	help
1119bab9bc65SAndi Kleen	  Machine Check support allows the processor to notify the
1120bab9bc65SAndi Kleen	  kernel if it detects a problem (e.g. overheating, data corruption).
1121506f1d07SSam Ravnborg	  The action the kernel takes depends on the severity of the problem,
1122bab9bc65SAndi Kleen	  ranging from warning messages to halting the machine.
11234efc0670SAndi Kleen
11245de97c9fSTony Luckconfig X86_MCELOG_LEGACY
11255de97c9fSTony Luck	bool "Support for deprecated /dev/mcelog character device"
11265de97c9fSTony Luck	depends on X86_MCE
1127a7f7f624SMasahiro Yamada	help
11285de97c9fSTony Luck	  Enable support for /dev/mcelog which is needed by the old mcelog
11295de97c9fSTony Luck	  userspace logging daemon. Consider switching to the new generation
11305de97c9fSTony Luck	  rasdaemon solution.
11315de97c9fSTony Luck
1132506f1d07SSam Ravnborgconfig X86_MCE_INTEL
11333c2362e6SHarvey Harrison	def_bool y
11343c2362e6SHarvey Harrison	prompt "Intel MCE features"
1135c1ebf835SAndi Kleen	depends on X86_MCE && X86_LOCAL_APIC
1136a7f7f624SMasahiro Yamada	help
1137506f1d07SSam Ravnborg	   Additional support for intel specific MCE features such as
1138506f1d07SSam Ravnborg	   the thermal monitor.
1139506f1d07SSam Ravnborg
1140506f1d07SSam Ravnborgconfig X86_MCE_AMD
11413c2362e6SHarvey Harrison	def_bool y
11423c2362e6SHarvey Harrison	prompt "AMD MCE features"
1143f5382de9SYazen Ghannam	depends on X86_MCE && X86_LOCAL_APIC && AMD_NB
1144a7f7f624SMasahiro Yamada	help
1145506f1d07SSam Ravnborg	   Additional support for AMD specific MCE features such as
1146506f1d07SSam Ravnborg	   the DRAM Error Threshold.
1147506f1d07SSam Ravnborg
11484efc0670SAndi Kleenconfig X86_ANCIENT_MCE
11496fc108a0SJan Beulich	bool "Support for old Pentium 5 / WinChip machine checks"
1150c31d9633SAndi Kleen	depends on X86_32 && X86_MCE
1151a7f7f624SMasahiro Yamada	help
11524efc0670SAndi Kleen	  Include support for machine check handling on old Pentium 5 or WinChip
11535065a706SMasanari Iida	  systems. These typically need to be enabled explicitly on the command
11544efc0670SAndi Kleen	  line.
11554efc0670SAndi Kleen
1156b2762686SAndi Kleenconfig X86_MCE_THRESHOLD
1157b2762686SAndi Kleen	depends on X86_MCE_AMD || X86_MCE_INTEL
11586fc108a0SJan Beulich	def_bool y
1159b2762686SAndi Kleen
1160ea149b36SAndi Kleenconfig X86_MCE_INJECT
1161bc8e80d5SBorislav Petkov	depends on X86_MCE && X86_LOCAL_APIC && DEBUG_FS
1162ea149b36SAndi Kleen	tristate "Machine check injector support"
1163a7f7f624SMasahiro Yamada	help
1164ea149b36SAndi Kleen	  Provide support for injecting machine checks for testing purposes.
1165ea149b36SAndi Kleen	  If you don't know what a machine check is and you don't do kernel
1166ea149b36SAndi Kleen	  QA it is safe to say n.
1167ea149b36SAndi Kleen
116807dc900eSPeter Zijlstrasource "arch/x86/events/Kconfig"
1169e633c65aSKan Liang
11705aef51c3SAndy Lutomirskiconfig X86_LEGACY_VM86
11711e642812SIngo Molnar	bool "Legacy VM86 support"
1172506f1d07SSam Ravnborg	depends on X86_32
1173a7f7f624SMasahiro Yamada	help
11745aef51c3SAndy Lutomirski	  This option allows user programs to put the CPU into V8086
11755aef51c3SAndy Lutomirski	  mode, which is an 80286-era approximation of 16-bit real mode.
11765aef51c3SAndy Lutomirski
11775aef51c3SAndy Lutomirski	  Some very old versions of X and/or vbetool require this option
11785aef51c3SAndy Lutomirski	  for user mode setting.  Similarly, DOSEMU will use it if
11795aef51c3SAndy Lutomirski	  available to accelerate real mode DOS programs.  However, any
11805aef51c3SAndy Lutomirski	  recent version of DOSEMU, X, or vbetool should be fully
11815aef51c3SAndy Lutomirski	  functional even without kernel VM86 support, as they will all
11821e642812SIngo Molnar	  fall back to software emulation. Nevertheless, if you are using
11831e642812SIngo Molnar	  a 16-bit DOS program where 16-bit performance matters, vm86
11841e642812SIngo Molnar	  mode might be faster than emulation and you might want to
11851e642812SIngo Molnar	  enable this option.
11865aef51c3SAndy Lutomirski
11871e642812SIngo Molnar	  Note that any app that works on a 64-bit kernel is unlikely to
11881e642812SIngo Molnar	  need this option, as 64-bit kernels don't, and can't, support
11891e642812SIngo Molnar	  V8086 mode. This option is also unrelated to 16-bit protected
11901e642812SIngo Molnar	  mode and is not needed to run most 16-bit programs under Wine.
11915aef51c3SAndy Lutomirski
11921e642812SIngo Molnar	  Enabling this option increases the complexity of the kernel
11931e642812SIngo Molnar	  and slows down exception handling a tiny bit.
11945aef51c3SAndy Lutomirski
11951e642812SIngo Molnar	  If unsure, say N here.
11965aef51c3SAndy Lutomirski
11975aef51c3SAndy Lutomirskiconfig VM86
11985aef51c3SAndy Lutomirski	bool
11995aef51c3SAndy Lutomirski	default X86_LEGACY_VM86
120034273f41SH. Peter Anvin
120134273f41SH. Peter Anvinconfig X86_16BIT
120234273f41SH. Peter Anvin	bool "Enable support for 16-bit segments" if EXPERT
120334273f41SH. Peter Anvin	default y
1204a5b9e5a2SAndy Lutomirski	depends on MODIFY_LDT_SYSCALL
1205a7f7f624SMasahiro Yamada	help
120634273f41SH. Peter Anvin	  This option is required by programs like Wine to run 16-bit
120734273f41SH. Peter Anvin	  protected mode legacy code on x86 processors.  Disabling
120834273f41SH. Peter Anvin	  this option saves about 300 bytes on i386, or around 6K text
120934273f41SH. Peter Anvin	  plus 16K runtime memory on x86-64,
121034273f41SH. Peter Anvin
121134273f41SH. Peter Anvinconfig X86_ESPFIX32
121234273f41SH. Peter Anvin	def_bool y
121334273f41SH. Peter Anvin	depends on X86_16BIT && X86_32
1214506f1d07SSam Ravnborg
1215197725deSH. Peter Anvinconfig X86_ESPFIX64
1216197725deSH. Peter Anvin	def_bool y
121734273f41SH. Peter Anvin	depends on X86_16BIT && X86_64
1218506f1d07SSam Ravnborg
12191ad83c85SAndy Lutomirskiconfig X86_VSYSCALL_EMULATION
12201ad83c85SAndy Lutomirski	bool "Enable vsyscall emulation" if EXPERT
12211ad83c85SAndy Lutomirski	default y
12221ad83c85SAndy Lutomirski	depends on X86_64
1223a7f7f624SMasahiro Yamada	help
12241ad83c85SAndy Lutomirski	 This enables emulation of the legacy vsyscall page.  Disabling
12251ad83c85SAndy Lutomirski	 it is roughly equivalent to booting with vsyscall=none, except
12261ad83c85SAndy Lutomirski	 that it will also disable the helpful warning if a program
12271ad83c85SAndy Lutomirski	 tries to use a vsyscall.  With this option set to N, offending
12281ad83c85SAndy Lutomirski	 programs will just segfault, citing addresses of the form
12291ad83c85SAndy Lutomirski	 0xffffffffff600?00.
12301ad83c85SAndy Lutomirski
12311ad83c85SAndy Lutomirski	 This option is required by many programs built before 2013, and
12321ad83c85SAndy Lutomirski	 care should be used even with newer programs if set to N.
12331ad83c85SAndy Lutomirski
12341ad83c85SAndy Lutomirski	 Disabling this option saves about 7K of kernel size and
12351ad83c85SAndy Lutomirski	 possibly 4K of additional runtime pagetable memory.
12361ad83c85SAndy Lutomirski
1237111e7b15SThomas Gleixnerconfig X86_IOPL_IOPERM
1238111e7b15SThomas Gleixner	bool "IOPERM and IOPL Emulation"
1239a24ca997SThomas Gleixner	default y
1240a7f7f624SMasahiro Yamada	help
1241111e7b15SThomas Gleixner	  This enables the ioperm() and iopl() syscalls which are necessary
1242111e7b15SThomas Gleixner	  for legacy applications.
1243111e7b15SThomas Gleixner
1244c8137aceSThomas Gleixner	  Legacy IOPL support is an overbroad mechanism which allows user
1245c8137aceSThomas Gleixner	  space aside of accessing all 65536 I/O ports also to disable
1246c8137aceSThomas Gleixner	  interrupts. To gain this access the caller needs CAP_SYS_RAWIO
1247c8137aceSThomas Gleixner	  capabilities and permission from potentially active security
1248c8137aceSThomas Gleixner	  modules.
1249c8137aceSThomas Gleixner
1250c8137aceSThomas Gleixner	  The emulation restricts the functionality of the syscall to
1251c8137aceSThomas Gleixner	  only allowing the full range I/O port access, but prevents the
1252a24ca997SThomas Gleixner	  ability to disable interrupts from user space which would be
1253a24ca997SThomas Gleixner	  granted if the hardware IOPL mechanism would be used.
1254c8137aceSThomas Gleixner
1255506f1d07SSam Ravnborgconfig TOSHIBA
1256506f1d07SSam Ravnborg	tristate "Toshiba Laptop support"
1257506f1d07SSam Ravnborg	depends on X86_32
1258a7f7f624SMasahiro Yamada	help
1259506f1d07SSam Ravnborg	  This adds a driver to safely access the System Management Mode of
1260506f1d07SSam Ravnborg	  the CPU on Toshiba portables with a genuine Toshiba BIOS. It does
1261506f1d07SSam Ravnborg	  not work on models with a Phoenix BIOS. The System Management Mode
1262506f1d07SSam Ravnborg	  is used to set the BIOS and power saving options on Toshiba portables.
1263506f1d07SSam Ravnborg
1264506f1d07SSam Ravnborg	  For information on utilities to make use of this driver see the
1265506f1d07SSam Ravnborg	  Toshiba Linux utilities web site at:
1266506f1d07SSam Ravnborg	  <http://www.buzzard.org.uk/toshiba/>.
1267506f1d07SSam Ravnborg
1268506f1d07SSam Ravnborg	  Say Y if you intend to run this kernel on a Toshiba portable.
1269506f1d07SSam Ravnborg	  Say N otherwise.
1270506f1d07SSam Ravnborg
1271506f1d07SSam Ravnborgconfig I8K
1272039ae585SPali Rohár	tristate "Dell i8k legacy laptop support"
1273ef775a0eSRandy Dunlap	depends on HWMON
1274ef775a0eSRandy Dunlap	depends on PROC_FS
1275039ae585SPali Rohár	select SENSORS_DELL_SMM
1276a7f7f624SMasahiro Yamada	help
1277039ae585SPali Rohár	  This option enables legacy /proc/i8k userspace interface in hwmon
1278039ae585SPali Rohár	  dell-smm-hwmon driver. Character file /proc/i8k reports bios version,
1279039ae585SPali Rohár	  temperature and allows controlling fan speeds of Dell laptops via
1280039ae585SPali Rohár	  System Management Mode. For old Dell laptops (like Dell Inspiron 8000)
1281039ae585SPali Rohár	  it reports also power and hotkey status. For fan speed control is
1282039ae585SPali Rohár	  needed userspace package i8kutils.
1283506f1d07SSam Ravnborg
1284039ae585SPali Rohár	  Say Y if you intend to run this kernel on old Dell laptops or want to
1285039ae585SPali Rohár	  use userspace package i8kutils.
1286506f1d07SSam Ravnborg	  Say N otherwise.
1287506f1d07SSam Ravnborg
1288506f1d07SSam Ravnborgconfig X86_REBOOTFIXUPS
12899ba16087SJan Beulich	bool "Enable X86 board specific fixups for reboot"
12909ba16087SJan Beulich	depends on X86_32
1291a7f7f624SMasahiro Yamada	help
1292506f1d07SSam Ravnborg	  This enables chipset and/or board specific fixups to be done
1293506f1d07SSam Ravnborg	  in order to get reboot to work correctly. This is only needed on
1294506f1d07SSam Ravnborg	  some combinations of hardware and BIOS. The symptom, for which
1295506f1d07SSam Ravnborg	  this config is intended, is when reboot ends with a stalled/hung
1296506f1d07SSam Ravnborg	  system.
1297506f1d07SSam Ravnborg
1298506f1d07SSam Ravnborg	  Currently, the only fixup is for the Geode machines using
12995e3a77e9SFlorian Fainelli	  CS5530A and CS5536 chipsets and the RDC R-321x SoC.
1300506f1d07SSam Ravnborg
1301506f1d07SSam Ravnborg	  Say Y if you want to enable the fixup. Currently, it's safe to
1302506f1d07SSam Ravnborg	  enable this option even if you don't need it.
1303506f1d07SSam Ravnborg	  Say N otherwise.
1304506f1d07SSam Ravnborg
1305506f1d07SSam Ravnborgconfig MICROCODE
13069a2bc335SBorislav Petkov	bool "CPU microcode loading support"
13079a2bc335SBorislav Petkov	default y
130880030e3dSBorislav Petkov	depends on CPU_SUP_AMD || CPU_SUP_INTEL
1309a7f7f624SMasahiro Yamada	help
1310506f1d07SSam Ravnborg	  If you say Y here, you will be able to update the microcode on
13115f9c01aaSBorislav Petkov	  Intel and AMD processors. The Intel support is for the IA32 family,
13125f9c01aaSBorislav Petkov	  e.g. Pentium Pro, Pentium II, Pentium III, Pentium 4, Xeon etc. The
13135f9c01aaSBorislav Petkov	  AMD support is for families 0x10 and later. You will obviously need
13145f9c01aaSBorislav Petkov	  the actual microcode binary data itself which is not shipped with
13155f9c01aaSBorislav Petkov	  the Linux kernel.
1316506f1d07SSam Ravnborg
13175f9c01aaSBorislav Petkov	  The preferred method to load microcode from a detached initrd is described
1318cb1aaebeSMauro Carvalho Chehab	  in Documentation/x86/microcode.rst. For that you need to enable
13195f9c01aaSBorislav Petkov	  CONFIG_BLK_DEV_INITRD in order for the loader to be able to scan the
13205f9c01aaSBorislav Petkov	  initrd for microcode blobs.
1321506f1d07SSam Ravnborg
1322c508c46eSBenjamin Gilbert	  In addition, you can build the microcode into the kernel. For that you
1323c508c46eSBenjamin Gilbert	  need to add the vendor-supplied microcode to the CONFIG_EXTRA_FIRMWARE
1324c508c46eSBenjamin Gilbert	  config option.
1325506f1d07SSam Ravnborg
13268d86f390SPeter Orubaconfig MICROCODE_INTEL
1327e43f6e67SBorislav Petkov	bool "Intel microcode loading support"
13288d86f390SPeter Oruba	depends on MICROCODE
13298d86f390SPeter Oruba	default MICROCODE
1330a7f7f624SMasahiro Yamada	help
13318d86f390SPeter Oruba	  This options enables microcode patch loading support for Intel
13328d86f390SPeter Oruba	  processors.
13338d86f390SPeter Oruba
1334b8989db9SAlan	  For the current Intel microcode data package go to
1335b8989db9SAlan	  <https://downloadcenter.intel.com> and search for
1336b8989db9SAlan	  'Linux Processor Microcode Data File'.
13378d86f390SPeter Oruba
133880cc9f10SPeter Orubaconfig MICROCODE_AMD
1339e43f6e67SBorislav Petkov	bool "AMD microcode loading support"
134080cc9f10SPeter Oruba	depends on MICROCODE
1341a7f7f624SMasahiro Yamada	help
134280cc9f10SPeter Oruba	  If you select this option, microcode patch loading support for AMD
134380cc9f10SPeter Oruba	  processors will be enabled.
134480cc9f10SPeter Oruba
1345506f1d07SSam Ravnborgconfig MICROCODE_OLD_INTERFACE
1346c02f48e0SBorislav Petkov	bool "Ancient loading interface (DEPRECATED)"
1347c02f48e0SBorislav Petkov	default n
1348506f1d07SSam Ravnborg	depends on MICROCODE
1349a7f7f624SMasahiro Yamada	help
1350c02f48e0SBorislav Petkov	  DO NOT USE THIS! This is the ancient /dev/cpu/microcode interface
1351c02f48e0SBorislav Petkov	  which was used by userspace tools like iucode_tool and microcode.ctl.
1352c02f48e0SBorislav Petkov	  It is inadequate because it runs too late to be able to properly
1353c02f48e0SBorislav Petkov	  load microcode on a machine and it needs special tools. Instead, you
1354c02f48e0SBorislav Petkov	  should've switched to the early loading method with the initrd or
1355cb1aaebeSMauro Carvalho Chehab	  builtin microcode by now: Documentation/x86/microcode.rst
1356506f1d07SSam Ravnborg
1357506f1d07SSam Ravnborgconfig X86_MSR
1358506f1d07SSam Ravnborg	tristate "/dev/cpu/*/msr - Model-specific register support"
1359a7f7f624SMasahiro Yamada	help
1360506f1d07SSam Ravnborg	  This device gives privileged processes access to the x86
1361506f1d07SSam Ravnborg	  Model-Specific Registers (MSRs).  It is a character device with
1362506f1d07SSam Ravnborg	  major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr.
1363506f1d07SSam Ravnborg	  MSR accesses are directed to a specific CPU on multi-processor
1364506f1d07SSam Ravnborg	  systems.
1365506f1d07SSam Ravnborg
1366506f1d07SSam Ravnborgconfig X86_CPUID
1367506f1d07SSam Ravnborg	tristate "/dev/cpu/*/cpuid - CPU information support"
1368a7f7f624SMasahiro Yamada	help
1369506f1d07SSam Ravnborg	  This device gives processes access to the x86 CPUID instruction to
1370506f1d07SSam Ravnborg	  be executed on a specific processor.  It is a character device
1371506f1d07SSam Ravnborg	  with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to
1372506f1d07SSam Ravnborg	  /dev/cpu/31/cpuid.
1373506f1d07SSam Ravnborg
1374506f1d07SSam Ravnborgchoice
1375506f1d07SSam Ravnborg	prompt "High Memory Support"
13766fc108a0SJan Beulich	default HIGHMEM4G
1377506f1d07SSam Ravnborg	depends on X86_32
1378506f1d07SSam Ravnborg
1379506f1d07SSam Ravnborgconfig NOHIGHMEM
1380506f1d07SSam Ravnborg	bool "off"
1381a7f7f624SMasahiro Yamada	help
1382506f1d07SSam Ravnborg	  Linux can use up to 64 Gigabytes of physical memory on x86 systems.
1383506f1d07SSam Ravnborg	  However, the address space of 32-bit x86 processors is only 4
1384506f1d07SSam Ravnborg	  Gigabytes large. That means that, if you have a large amount of
1385506f1d07SSam Ravnborg	  physical memory, not all of it can be "permanently mapped" by the
1386506f1d07SSam Ravnborg	  kernel. The physical memory that's not permanently mapped is called
1387506f1d07SSam Ravnborg	  "high memory".
1388506f1d07SSam Ravnborg
1389506f1d07SSam Ravnborg	  If you are compiling a kernel which will never run on a machine with
1390506f1d07SSam Ravnborg	  more than 1 Gigabyte total physical RAM, answer "off" here (default
1391506f1d07SSam Ravnborg	  choice and suitable for most users). This will result in a "3GB/1GB"
1392506f1d07SSam Ravnborg	  split: 3GB are mapped so that each process sees a 3GB virtual memory
1393506f1d07SSam Ravnborg	  space and the remaining part of the 4GB virtual memory space is used
1394506f1d07SSam Ravnborg	  by the kernel to permanently map as much physical memory as
1395506f1d07SSam Ravnborg	  possible.
1396506f1d07SSam Ravnborg
1397506f1d07SSam Ravnborg	  If the machine has between 1 and 4 Gigabytes physical RAM, then
1398506f1d07SSam Ravnborg	  answer "4GB" here.
1399506f1d07SSam Ravnborg
1400506f1d07SSam Ravnborg	  If more than 4 Gigabytes is used then answer "64GB" here. This
1401506f1d07SSam Ravnborg	  selection turns Intel PAE (Physical Address Extension) mode on.
1402506f1d07SSam Ravnborg	  PAE implements 3-level paging on IA32 processors. PAE is fully
1403506f1d07SSam Ravnborg	  supported by Linux, PAE mode is implemented on all recent Intel
1404506f1d07SSam Ravnborg	  processors (Pentium Pro and better). NOTE: If you say "64GB" here,
1405506f1d07SSam Ravnborg	  then the kernel will not boot on CPUs that don't support PAE!
1406506f1d07SSam Ravnborg
1407506f1d07SSam Ravnborg	  The actual amount of total physical memory will either be
1408506f1d07SSam Ravnborg	  auto detected or can be forced by using a kernel command line option
1409506f1d07SSam Ravnborg	  such as "mem=256M". (Try "man bootparam" or see the documentation of
1410506f1d07SSam Ravnborg	  your boot loader (lilo or loadlin) about how to pass options to the
1411506f1d07SSam Ravnborg	  kernel at boot time.)
1412506f1d07SSam Ravnborg
1413506f1d07SSam Ravnborg	  If unsure, say "off".
1414506f1d07SSam Ravnborg
1415506f1d07SSam Ravnborgconfig HIGHMEM4G
1416506f1d07SSam Ravnborg	bool "4GB"
1417a7f7f624SMasahiro Yamada	help
1418506f1d07SSam Ravnborg	  Select this if you have a 32-bit processor and between 1 and 4
1419506f1d07SSam Ravnborg	  gigabytes of physical RAM.
1420506f1d07SSam Ravnborg
1421506f1d07SSam Ravnborgconfig HIGHMEM64G
1422506f1d07SSam Ravnborg	bool "64GB"
1423225bac2dSLukas Bulwahn	depends on !M486SX && !M486 && !M586 && !M586TSC && !M586MMX && !MGEODE_LX && !MGEODEGX1 && !MCYRIXIII && !MELAN && !MWINCHIPC6 && !MWINCHIP3D && !MK6
1424506f1d07SSam Ravnborg	select X86_PAE
1425a7f7f624SMasahiro Yamada	help
1426506f1d07SSam Ravnborg	  Select this if you have a 32-bit processor and more than 4
1427506f1d07SSam Ravnborg	  gigabytes of physical RAM.
1428506f1d07SSam Ravnborg
1429506f1d07SSam Ravnborgendchoice
1430506f1d07SSam Ravnborg
1431506f1d07SSam Ravnborgchoice
14326a108a14SDavid Rientjes	prompt "Memory split" if EXPERT
1433506f1d07SSam Ravnborg	default VMSPLIT_3G
1434506f1d07SSam Ravnborg	depends on X86_32
1435a7f7f624SMasahiro Yamada	help
1436506f1d07SSam Ravnborg	  Select the desired split between kernel and user memory.
1437506f1d07SSam Ravnborg
1438506f1d07SSam Ravnborg	  If the address range available to the kernel is less than the
1439506f1d07SSam Ravnborg	  physical memory installed, the remaining memory will be available
1440506f1d07SSam Ravnborg	  as "high memory". Accessing high memory is a little more costly
1441506f1d07SSam Ravnborg	  than low memory, as it needs to be mapped into the kernel first.
1442506f1d07SSam Ravnborg	  Note that increasing the kernel address space limits the range
1443506f1d07SSam Ravnborg	  available to user programs, making the address space there
1444506f1d07SSam Ravnborg	  tighter.  Selecting anything other than the default 3G/1G split
1445506f1d07SSam Ravnborg	  will also likely make your kernel incompatible with binary-only
1446506f1d07SSam Ravnborg	  kernel modules.
1447506f1d07SSam Ravnborg
1448506f1d07SSam Ravnborg	  If you are not absolutely sure what you are doing, leave this
1449506f1d07SSam Ravnborg	  option alone!
1450506f1d07SSam Ravnborg
1451506f1d07SSam Ravnborg	config VMSPLIT_3G
1452506f1d07SSam Ravnborg		bool "3G/1G user/kernel split"
1453506f1d07SSam Ravnborg	config VMSPLIT_3G_OPT
1454506f1d07SSam Ravnborg		depends on !X86_PAE
1455506f1d07SSam Ravnborg		bool "3G/1G user/kernel split (for full 1G low memory)"
1456506f1d07SSam Ravnborg	config VMSPLIT_2G
1457506f1d07SSam Ravnborg		bool "2G/2G user/kernel split"
1458506f1d07SSam Ravnborg	config VMSPLIT_2G_OPT
1459506f1d07SSam Ravnborg		depends on !X86_PAE
1460506f1d07SSam Ravnborg		bool "2G/2G user/kernel split (for full 2G low memory)"
1461506f1d07SSam Ravnborg	config VMSPLIT_1G
1462506f1d07SSam Ravnborg		bool "1G/3G user/kernel split"
1463506f1d07SSam Ravnborgendchoice
1464506f1d07SSam Ravnborg
1465506f1d07SSam Ravnborgconfig PAGE_OFFSET
1466506f1d07SSam Ravnborg	hex
1467506f1d07SSam Ravnborg	default 0xB0000000 if VMSPLIT_3G_OPT
1468506f1d07SSam Ravnborg	default 0x80000000 if VMSPLIT_2G
1469506f1d07SSam Ravnborg	default 0x78000000 if VMSPLIT_2G_OPT
1470506f1d07SSam Ravnborg	default 0x40000000 if VMSPLIT_1G
1471506f1d07SSam Ravnborg	default 0xC0000000
1472506f1d07SSam Ravnborg	depends on X86_32
1473506f1d07SSam Ravnborg
1474506f1d07SSam Ravnborgconfig HIGHMEM
14753c2362e6SHarvey Harrison	def_bool y
1476506f1d07SSam Ravnborg	depends on X86_32 && (HIGHMEM64G || HIGHMEM4G)
1477506f1d07SSam Ravnborg
1478506f1d07SSam Ravnborgconfig X86_PAE
14799ba16087SJan Beulich	bool "PAE (Physical Address Extension) Support"
1480506f1d07SSam Ravnborg	depends on X86_32 && !HIGHMEM4G
1481d4a451d5SChristoph Hellwig	select PHYS_ADDR_T_64BIT
14829d99c712SChristian Melki	select SWIOTLB
1483a7f7f624SMasahiro Yamada	help
1484506f1d07SSam Ravnborg	  PAE is required for NX support, and furthermore enables
1485506f1d07SSam Ravnborg	  larger swapspace support for non-overcommit purposes. It
1486506f1d07SSam Ravnborg	  has the cost of more pagetable lookup overhead, and also
1487506f1d07SSam Ravnborg	  consumes more pagetable space per process.
1488506f1d07SSam Ravnborg
148977ef56e4SKirill A. Shutemovconfig X86_5LEVEL
149077ef56e4SKirill A. Shutemov	bool "Enable 5-level page tables support"
149118ec1eafSKirill A. Shutemov	default y
1492eedb92abSKirill A. Shutemov	select DYNAMIC_MEMORY_LAYOUT
1493162434e7SKirill A. Shutemov	select SPARSEMEM_VMEMMAP
149477ef56e4SKirill A. Shutemov	depends on X86_64
1495a7f7f624SMasahiro Yamada	help
149677ef56e4SKirill A. Shutemov	  5-level paging enables access to larger address space:
149777ef56e4SKirill A. Shutemov	  upto 128 PiB of virtual address space and 4 PiB of
149877ef56e4SKirill A. Shutemov	  physical address space.
149977ef56e4SKirill A. Shutemov
150077ef56e4SKirill A. Shutemov	  It will be supported by future Intel CPUs.
150177ef56e4SKirill A. Shutemov
15026657fca0SKirill A. Shutemov	  A kernel with the option enabled can be booted on machines that
15036657fca0SKirill A. Shutemov	  support 4- or 5-level paging.
150477ef56e4SKirill A. Shutemov
1505cb1aaebeSMauro Carvalho Chehab	  See Documentation/x86/x86_64/5level-paging.rst for more
150677ef56e4SKirill A. Shutemov	  information.
150777ef56e4SKirill A. Shutemov
150877ef56e4SKirill A. Shutemov	  Say N if unsure.
150977ef56e4SKirill A. Shutemov
151010971ab2SIngo Molnarconfig X86_DIRECT_GBPAGES
1511e5008abeSLuis R. Rodriguez	def_bool y
15122e1da13fSVlastimil Babka	depends on X86_64
1513a7f7f624SMasahiro Yamada	help
151410971ab2SIngo Molnar	  Certain kernel features effectively disable kernel
151510971ab2SIngo Molnar	  linear 1 GB mappings (even if the CPU otherwise
151610971ab2SIngo Molnar	  supports them), so don't confuse the user by printing
151710971ab2SIngo Molnar	  that we have them enabled.
15189e899816SNick Piggin
15195c280cf6SThomas Gleixnerconfig X86_CPA_STATISTICS
15205c280cf6SThomas Gleixner	bool "Enable statistic for Change Page Attribute"
15215c280cf6SThomas Gleixner	depends on DEBUG_FS
1522a7f7f624SMasahiro Yamada	help
1523b75baaf3SIngo Molnar	  Expose statistics about the Change Page Attribute mechanism, which
1524a943245aSColin Ian King	  helps to determine the effectiveness of preserving large and huge
15255c280cf6SThomas Gleixner	  page mappings when mapping protections are changed.
15265c280cf6SThomas Gleixner
15277744ccdbSTom Lendackyconfig AMD_MEM_ENCRYPT
15287744ccdbSTom Lendacky	bool "AMD Secure Memory Encryption (SME) support"
15297744ccdbSTom Lendacky	depends on X86_64 && CPU_SUP_AMD
153082fef0adSDavid Rientjes	select DMA_COHERENT_POOL
153194d49eb3SKirill A. Shutemov	select DYNAMIC_PHYSICAL_MASK
1532ce9084baSArd Biesheuvel	select ARCH_USE_MEMREMAP_PROT
15339087c375STom Lendacky	select ARCH_HAS_FORCE_DMA_UNENCRYPTED
1534597cfe48SJoerg Roedel	select INSTRUCTION_DECODER
153522916417STom Lendacky	select ARCH_HAS_RESTRICTED_VIRTIO_MEMORY_ACCESS
1536aa5a4611STom Lendacky	select ARCH_HAS_CC_PLATFORM
1537a7f7f624SMasahiro Yamada	help
15387744ccdbSTom Lendacky	  Say yes to enable support for the encryption of system memory.
15397744ccdbSTom Lendacky	  This requires an AMD processor that supports Secure Memory
15407744ccdbSTom Lendacky	  Encryption (SME).
15417744ccdbSTom Lendacky
15427744ccdbSTom Lendackyconfig AMD_MEM_ENCRYPT_ACTIVE_BY_DEFAULT
15437744ccdbSTom Lendacky	bool "Activate AMD Secure Memory Encryption (SME) by default"
15447744ccdbSTom Lendacky	depends on AMD_MEM_ENCRYPT
1545a7f7f624SMasahiro Yamada	help
15467744ccdbSTom Lendacky	  Say yes to have system memory encrypted by default if running on
15477744ccdbSTom Lendacky	  an AMD processor that supports Secure Memory Encryption (SME).
15487744ccdbSTom Lendacky
15497744ccdbSTom Lendacky	  If set to Y, then the encryption of system memory can be
15507744ccdbSTom Lendacky	  deactivated with the mem_encrypt=off command line option.
15517744ccdbSTom Lendacky
15527744ccdbSTom Lendacky	  If set to N, then the encryption of system memory can be
15537744ccdbSTom Lendacky	  activated with the mem_encrypt=on command line option.
15547744ccdbSTom Lendacky
1555506f1d07SSam Ravnborg# Common NUMA Features
1556506f1d07SSam Ravnborgconfig NUMA
1557e133f6eaSRandy Dunlap	bool "NUMA Memory Allocation and Scheduler Support"
1558506f1d07SSam Ravnborg	depends on SMP
1559b5660ba7SH. Peter Anvin	depends on X86_64 || (X86_32 && HIGHMEM64G && X86_BIGSMP)
1560b5660ba7SH. Peter Anvin	default y if X86_BIGSMP
1561a7f7f624SMasahiro Yamada	help
1562e133f6eaSRandy Dunlap	  Enable NUMA (Non-Uniform Memory Access) support.
1563fd51b2d7SKOSAKI Motohiro
1564506f1d07SSam Ravnborg	  The kernel will try to allocate memory used by a CPU on the
1565506f1d07SSam Ravnborg	  local memory controller of the CPU and add some more
1566506f1d07SSam Ravnborg	  NUMA awareness to the kernel.
1567506f1d07SSam Ravnborg
1568c280ea5eSIngo Molnar	  For 64-bit this is recommended if the system is Intel Core i7
1569fd51b2d7SKOSAKI Motohiro	  (or later), AMD Opteron, or EM64T NUMA.
1570fd51b2d7SKOSAKI Motohiro
1571b5660ba7SH. Peter Anvin	  For 32-bit this is only needed if you boot a 32-bit
15727cf6c945SDavid Rientjes	  kernel on a 64-bit NUMA platform.
1573fd51b2d7SKOSAKI Motohiro
1574fd51b2d7SKOSAKI Motohiro	  Otherwise, you should say N.
1575506f1d07SSam Ravnborg
1576eec1d4faSHans Rosenfeldconfig AMD_NUMA
15773c2362e6SHarvey Harrison	def_bool y
15783c2362e6SHarvey Harrison	prompt "Old style AMD Opteron NUMA detection"
15795da0ef9aSTejun Heo	depends on X86_64 && NUMA && PCI
1580a7f7f624SMasahiro Yamada	help
1581eec1d4faSHans Rosenfeld	  Enable AMD NUMA node topology detection.  You should say Y here if
1582eec1d4faSHans Rosenfeld	  you have a multi processor AMD system. This uses an old method to
1583eec1d4faSHans Rosenfeld	  read the NUMA configuration directly from the builtin Northbridge
1584eec1d4faSHans Rosenfeld	  of Opteron. It is recommended to use X86_64_ACPI_NUMA instead,
1585eec1d4faSHans Rosenfeld	  which also takes priority if both are compiled in.
1586506f1d07SSam Ravnborg
1587506f1d07SSam Ravnborgconfig X86_64_ACPI_NUMA
15883c2362e6SHarvey Harrison	def_bool y
15893c2362e6SHarvey Harrison	prompt "ACPI NUMA detection"
1590506f1d07SSam Ravnborg	depends on X86_64 && NUMA && ACPI && PCI
1591506f1d07SSam Ravnborg	select ACPI_NUMA
1592a7f7f624SMasahiro Yamada	help
1593506f1d07SSam Ravnborg	  Enable ACPI SRAT based node topology detection.
1594506f1d07SSam Ravnborg
1595506f1d07SSam Ravnborgconfig NUMA_EMU
1596506f1d07SSam Ravnborg	bool "NUMA emulation"
15971b7e03efSTejun Heo	depends on NUMA
1598a7f7f624SMasahiro Yamada	help
1599506f1d07SSam Ravnborg	  Enable NUMA emulation. A flat machine will be split
1600506f1d07SSam Ravnborg	  into virtual nodes when booted with "numa=fake=N", where N is the
1601506f1d07SSam Ravnborg	  number of nodes. This is only useful for debugging.
1602506f1d07SSam Ravnborg
1603506f1d07SSam Ravnborgconfig NODES_SHIFT
1604d25e26b6SLinus Torvalds	int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP
160551591e31SDavid Rientjes	range 1 10
160651591e31SDavid Rientjes	default "10" if MAXSMP
1607506f1d07SSam Ravnborg	default "6" if X86_64
1608506f1d07SSam Ravnborg	default "3"
1609a9ee6cf5SMike Rapoport	depends on NUMA
1610a7f7f624SMasahiro Yamada	help
16111184dc2fSMike Travis	  Specify the maximum number of NUMA Nodes available on the target
1612692105b8SMatt LaPlante	  system.  Increases memory reserved to accommodate various tables.
1613506f1d07SSam Ravnborg
1614506f1d07SSam Ravnborgconfig ARCH_FLATMEM_ENABLE
1615506f1d07SSam Ravnborg	def_bool y
16163b16651fSTejun Heo	depends on X86_32 && !NUMA
1617506f1d07SSam Ravnborg
1618506f1d07SSam Ravnborgconfig ARCH_SPARSEMEM_ENABLE
1619506f1d07SSam Ravnborg	def_bool y
16206ea30386SKees Cook	depends on X86_64 || NUMA || X86_32 || X86_32_NON_STANDARD
1621506f1d07SSam Ravnborg	select SPARSEMEM_STATIC if X86_32
1622506f1d07SSam Ravnborg	select SPARSEMEM_VMEMMAP_ENABLE if X86_64
1623506f1d07SSam Ravnborg
16243b16651fSTejun Heoconfig ARCH_SPARSEMEM_DEFAULT
16256ad57f7fSMike Rapoport	def_bool X86_64 || (NUMA && X86_32)
16263b16651fSTejun Heo
1627506f1d07SSam Ravnborgconfig ARCH_SELECT_MEMORY_MODEL
1628506f1d07SSam Ravnborg	def_bool y
1629b263295dSChristoph Lameter	depends on ARCH_SPARSEMEM_ENABLE
1630506f1d07SSam Ravnborg
1631506f1d07SSam Ravnborgconfig ARCH_MEMORY_PROBE
1632a0842b70SToshi Kani	bool "Enable sysfs memory/probe interface"
16335c11f00bSDavid Hildenbrand	depends on MEMORY_HOTPLUG
1634a0842b70SToshi Kani	help
1635a0842b70SToshi Kani	  This option enables a sysfs memory/probe interface for testing.
1636cb1aaebeSMauro Carvalho Chehab	  See Documentation/admin-guide/mm/memory-hotplug.rst for more information.
1637a0842b70SToshi Kani	  If you are unsure how to answer this question, answer N.
1638506f1d07SSam Ravnborg
16393b16651fSTejun Heoconfig ARCH_PROC_KCORE_TEXT
16403b16651fSTejun Heo	def_bool y
16413b16651fSTejun Heo	depends on X86_64 && PROC_KCORE
16423b16651fSTejun Heo
1643a29815a3SAvi Kivityconfig ILLEGAL_POINTER_VALUE
1644a29815a3SAvi Kivity	hex
1645a29815a3SAvi Kivity	default 0 if X86_32
1646a29815a3SAvi Kivity	default 0xdead000000000000 if X86_64
1647a29815a3SAvi Kivity
16487a67832cSDan Williamsconfig X86_PMEM_LEGACY_DEVICE
16497a67832cSDan Williams	bool
16507a67832cSDan Williams
1651ec776ef6SChristoph Hellwigconfig X86_PMEM_LEGACY
16527a67832cSDan Williams	tristate "Support non-standard NVDIMMs and ADR protected memory"
16539f53f9faSDan Williams	depends on PHYS_ADDR_T_64BIT
16549f53f9faSDan Williams	depends on BLK_DEV
16557a67832cSDan Williams	select X86_PMEM_LEGACY_DEVICE
16567b27a862SDan Williams	select NUMA_KEEP_MEMINFO if NUMA
16579f53f9faSDan Williams	select LIBNVDIMM
1658ec776ef6SChristoph Hellwig	help
1659ec776ef6SChristoph Hellwig	  Treat memory marked using the non-standard e820 type of 12 as used
1660ec776ef6SChristoph Hellwig	  by the Intel Sandy Bridge-EP reference BIOS as protected memory.
1661ec776ef6SChristoph Hellwig	  The kernel will offer these regions to the 'pmem' driver so
1662ec776ef6SChristoph Hellwig	  they can be used for persistent storage.
1663ec776ef6SChristoph Hellwig
1664ec776ef6SChristoph Hellwig	  Say Y if unsure.
1665ec776ef6SChristoph Hellwig
1666506f1d07SSam Ravnborgconfig HIGHPTE
1667506f1d07SSam Ravnborg	bool "Allocate 3rd-level pagetables from highmem"
16686fc108a0SJan Beulich	depends on HIGHMEM
1669a7f7f624SMasahiro Yamada	help
1670506f1d07SSam Ravnborg	  The VM uses one page table entry for each page of physical memory.
1671506f1d07SSam Ravnborg	  For systems with a lot of RAM, this can be wasteful of precious
1672506f1d07SSam Ravnborg	  low memory.  Setting this option will put user-space page table
1673506f1d07SSam Ravnborg	  entries in high memory.
1674506f1d07SSam Ravnborg
16759f077871SJeremy Fitzhardingeconfig X86_CHECK_BIOS_CORRUPTION
16769f077871SJeremy Fitzhardinge	bool "Check for low memory corruption"
1677a7f7f624SMasahiro Yamada	help
16789f077871SJeremy Fitzhardinge	  Periodically check for memory corruption in low memory, which
16799f077871SJeremy Fitzhardinge	  is suspected to be caused by BIOS.  Even when enabled in the
16809f077871SJeremy Fitzhardinge	  configuration, it is disabled at runtime.  Enable it by
16819f077871SJeremy Fitzhardinge	  setting "memory_corruption_check=1" on the kernel command
16829f077871SJeremy Fitzhardinge	  line.  By default it scans the low 64k of memory every 60
16839f077871SJeremy Fitzhardinge	  seconds; see the memory_corruption_check_size and
16849f077871SJeremy Fitzhardinge	  memory_corruption_check_period parameters in
16858c27ceffSMauro Carvalho Chehab	  Documentation/admin-guide/kernel-parameters.rst to adjust this.
16869f077871SJeremy Fitzhardinge
16879f077871SJeremy Fitzhardinge	  When enabled with the default parameters, this option has
16889f077871SJeremy Fitzhardinge	  almost no overhead, as it reserves a relatively small amount
16899f077871SJeremy Fitzhardinge	  of memory and scans it infrequently.  It both detects corruption
16909f077871SJeremy Fitzhardinge	  and prevents it from affecting the running system.
16919f077871SJeremy Fitzhardinge
16929f077871SJeremy Fitzhardinge	  It is, however, intended as a diagnostic tool; if repeatable
16939f077871SJeremy Fitzhardinge	  BIOS-originated corruption always affects the same memory,
16949f077871SJeremy Fitzhardinge	  you can use memmap= to prevent the kernel from using that
16959f077871SJeremy Fitzhardinge	  memory.
16969f077871SJeremy Fitzhardinge
1697c885df50SJeremy Fitzhardingeconfig X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK
1698c885df50SJeremy Fitzhardinge	bool "Set the default setting of memory_corruption_check"
1699c885df50SJeremy Fitzhardinge	depends on X86_CHECK_BIOS_CORRUPTION
1700c885df50SJeremy Fitzhardinge	default y
1701a7f7f624SMasahiro Yamada	help
1702c885df50SJeremy Fitzhardinge	  Set whether the default state of memory_corruption_check is
1703c885df50SJeremy Fitzhardinge	  on or off.
1704c885df50SJeremy Fitzhardinge
1705506f1d07SSam Ravnborgconfig MATH_EMULATION
1706506f1d07SSam Ravnborg	bool
1707a5b9e5a2SAndy Lutomirski	depends on MODIFY_LDT_SYSCALL
170887d6021bSArnd Bergmann	prompt "Math emulation" if X86_32 && (M486SX || MELAN)
1709a7f7f624SMasahiro Yamada	help
1710506f1d07SSam Ravnborg	  Linux can emulate a math coprocessor (used for floating point
1711506f1d07SSam Ravnborg	  operations) if you don't have one. 486DX and Pentium processors have
1712506f1d07SSam Ravnborg	  a math coprocessor built in, 486SX and 386 do not, unless you added
1713506f1d07SSam Ravnborg	  a 487DX or 387, respectively. (The messages during boot time can
1714506f1d07SSam Ravnborg	  give you some hints here ["man dmesg"].) Everyone needs either a
1715506f1d07SSam Ravnborg	  coprocessor or this emulation.
1716506f1d07SSam Ravnborg
1717506f1d07SSam Ravnborg	  If you don't have a math coprocessor, you need to say Y here; if you
1718506f1d07SSam Ravnborg	  say Y here even though you have a coprocessor, the coprocessor will
1719506f1d07SSam Ravnborg	  be used nevertheless. (This behavior can be changed with the kernel
1720506f1d07SSam Ravnborg	  command line option "no387", which comes handy if your coprocessor
1721506f1d07SSam Ravnborg	  is broken. Try "man bootparam" or see the documentation of your boot
1722506f1d07SSam Ravnborg	  loader (lilo or loadlin) about how to pass options to the kernel at
1723506f1d07SSam Ravnborg	  boot time.) This means that it is a good idea to say Y here if you
1724506f1d07SSam Ravnborg	  intend to use this kernel on different machines.
1725506f1d07SSam Ravnborg
1726506f1d07SSam Ravnborg	  More information about the internals of the Linux math coprocessor
1727506f1d07SSam Ravnborg	  emulation can be found in <file:arch/x86/math-emu/README>.
1728506f1d07SSam Ravnborg
1729506f1d07SSam Ravnborg	  If you are not sure, say Y; apart from resulting in a 66 KB bigger
1730506f1d07SSam Ravnborg	  kernel, it won't hurt.
1731506f1d07SSam Ravnborg
1732506f1d07SSam Ravnborgconfig MTRR
17336fc108a0SJan Beulich	def_bool y
17346a108a14SDavid Rientjes	prompt "MTRR (Memory Type Range Register) support" if EXPERT
1735a7f7f624SMasahiro Yamada	help
1736506f1d07SSam Ravnborg	  On Intel P6 family processors (Pentium Pro, Pentium II and later)
1737506f1d07SSam Ravnborg	  the Memory Type Range Registers (MTRRs) may be used to control
1738506f1d07SSam Ravnborg	  processor access to memory ranges. This is most useful if you have
1739506f1d07SSam Ravnborg	  a video (VGA) card on a PCI or AGP bus. Enabling write-combining
1740506f1d07SSam Ravnborg	  allows bus write transfers to be combined into a larger transfer
1741506f1d07SSam Ravnborg	  before bursting over the PCI/AGP bus. This can increase performance
1742506f1d07SSam Ravnborg	  of image write operations 2.5 times or more. Saying Y here creates a
1743506f1d07SSam Ravnborg	  /proc/mtrr file which may be used to manipulate your processor's
1744506f1d07SSam Ravnborg	  MTRRs. Typically the X server should use this.
1745506f1d07SSam Ravnborg
1746506f1d07SSam Ravnborg	  This code has a reasonably generic interface so that similar
1747506f1d07SSam Ravnborg	  control registers on other processors can be easily supported
1748506f1d07SSam Ravnborg	  as well:
1749506f1d07SSam Ravnborg
1750506f1d07SSam Ravnborg	  The Cyrix 6x86, 6x86MX and M II processors have Address Range
1751506f1d07SSam Ravnborg	  Registers (ARRs) which provide a similar functionality to MTRRs. For
1752506f1d07SSam Ravnborg	  these, the ARRs are used to emulate the MTRRs.
1753506f1d07SSam Ravnborg	  The AMD K6-2 (stepping 8 and above) and K6-3 processors have two
1754506f1d07SSam Ravnborg	  MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing
1755506f1d07SSam Ravnborg	  write-combining. All of these processors are supported by this code
1756506f1d07SSam Ravnborg	  and it makes sense to say Y here if you have one of them.
1757506f1d07SSam Ravnborg
1758506f1d07SSam Ravnborg	  Saying Y here also fixes a problem with buggy SMP BIOSes which only
1759506f1d07SSam Ravnborg	  set the MTRRs for the boot CPU and not for the secondary CPUs. This
1760506f1d07SSam Ravnborg	  can lead to all sorts of problems, so it's good to say Y here.
1761506f1d07SSam Ravnborg
1762506f1d07SSam Ravnborg	  You can safely say Y even if your machine doesn't have MTRRs, you'll
1763506f1d07SSam Ravnborg	  just add about 9 KB to your kernel.
1764506f1d07SSam Ravnborg
1765cb1aaebeSMauro Carvalho Chehab	  See <file:Documentation/x86/mtrr.rst> for more information.
1766506f1d07SSam Ravnborg
176795ffa243SYinghai Luconfig MTRR_SANITIZER
17682ffb3501SYinghai Lu	def_bool y
176995ffa243SYinghai Lu	prompt "MTRR cleanup support"
177095ffa243SYinghai Lu	depends on MTRR
1771a7f7f624SMasahiro Yamada	help
1772aba3728cSThomas Gleixner	  Convert MTRR layout from continuous to discrete, so X drivers can
1773aba3728cSThomas Gleixner	  add writeback entries.
177495ffa243SYinghai Lu
1775aba3728cSThomas Gleixner	  Can be disabled with disable_mtrr_cleanup on the kernel command line.
1776692105b8SMatt LaPlante	  The largest mtrr entry size for a continuous block can be set with
1777aba3728cSThomas Gleixner	  mtrr_chunk_size.
177895ffa243SYinghai Lu
17792ffb3501SYinghai Lu	  If unsure, say Y.
178095ffa243SYinghai Lu
178195ffa243SYinghai Luconfig MTRR_SANITIZER_ENABLE_DEFAULT
1782f5098d62SYinghai Lu	int "MTRR cleanup enable value (0-1)"
1783f5098d62SYinghai Lu	range 0 1
1784f5098d62SYinghai Lu	default "0"
178595ffa243SYinghai Lu	depends on MTRR_SANITIZER
1786a7f7f624SMasahiro Yamada	help
1787f5098d62SYinghai Lu	  Enable mtrr cleanup default value
178895ffa243SYinghai Lu
178912031a62SYinghai Luconfig MTRR_SANITIZER_SPARE_REG_NR_DEFAULT
179012031a62SYinghai Lu	int "MTRR cleanup spare reg num (0-7)"
179112031a62SYinghai Lu	range 0 7
179212031a62SYinghai Lu	default "1"
179312031a62SYinghai Lu	depends on MTRR_SANITIZER
1794a7f7f624SMasahiro Yamada	help
179512031a62SYinghai Lu	  mtrr cleanup spare entries default, it can be changed via
1796aba3728cSThomas Gleixner	  mtrr_spare_reg_nr=N on the kernel command line.
179712031a62SYinghai Lu
17982e5d9c85Svenkatesh.pallipadi@intel.comconfig X86_PAT
17996fc108a0SJan Beulich	def_bool y
18006a108a14SDavid Rientjes	prompt "x86 PAT support" if EXPERT
18012a8a2719SIngo Molnar	depends on MTRR
1802a7f7f624SMasahiro Yamada	help
18032e5d9c85Svenkatesh.pallipadi@intel.com	  Use PAT attributes to setup page level cache control.
1804042b78e4SVenki Pallipadi
18052e5d9c85Svenkatesh.pallipadi@intel.com	  PATs are the modern equivalents of MTRRs and are much more
18062e5d9c85Svenkatesh.pallipadi@intel.com	  flexible than MTRRs.
18072e5d9c85Svenkatesh.pallipadi@intel.com
18082e5d9c85Svenkatesh.pallipadi@intel.com	  Say N here if you see bootup problems (boot crash, boot hang,
1809042b78e4SVenki Pallipadi	  spontaneous reboots) or a non-working video driver.
18102e5d9c85Svenkatesh.pallipadi@intel.com
18112e5d9c85Svenkatesh.pallipadi@intel.com	  If unsure, say Y.
18122e5d9c85Svenkatesh.pallipadi@intel.com
181346cf98cdSVenkatesh Pallipadiconfig ARCH_USES_PG_UNCACHED
181446cf98cdSVenkatesh Pallipadi	def_bool y
181546cf98cdSVenkatesh Pallipadi	depends on X86_PAT
181646cf98cdSVenkatesh Pallipadi
1817628c6246SH. Peter Anvinconfig ARCH_RANDOM
1818628c6246SH. Peter Anvin	def_bool y
1819628c6246SH. Peter Anvin	prompt "x86 architectural random number generator" if EXPERT
1820a7f7f624SMasahiro Yamada	help
1821628c6246SH. Peter Anvin	  Enable the x86 architectural RDRAND instruction
1822628c6246SH. Peter Anvin	  (Intel Bull Mountain technology) to generate random numbers.
1823628c6246SH. Peter Anvin	  If supported, this is a high bandwidth, cryptographically
1824628c6246SH. Peter Anvin	  secure hardware random number generator.
1825628c6246SH. Peter Anvin
182651ae4a2dSH. Peter Anvinconfig X86_SMAP
182751ae4a2dSH. Peter Anvin	def_bool y
182851ae4a2dSH. Peter Anvin	prompt "Supervisor Mode Access Prevention" if EXPERT
1829a7f7f624SMasahiro Yamada	help
183051ae4a2dSH. Peter Anvin	  Supervisor Mode Access Prevention (SMAP) is a security
183151ae4a2dSH. Peter Anvin	  feature in newer Intel processors.  There is a small
183251ae4a2dSH. Peter Anvin	  performance cost if this enabled and turned on; there is
183351ae4a2dSH. Peter Anvin	  also a small increase in the kernel size if this is enabled.
183451ae4a2dSH. Peter Anvin
183551ae4a2dSH. Peter Anvin	  If unsure, say Y.
183651ae4a2dSH. Peter Anvin
1837b971880fSBabu Mogerconfig X86_UMIP
1838796ebc81SRicardo Neri	def_bool y
1839b971880fSBabu Moger	prompt "User Mode Instruction Prevention" if EXPERT
1840a7f7f624SMasahiro Yamada	help
1841b971880fSBabu Moger	  User Mode Instruction Prevention (UMIP) is a security feature in
1842b971880fSBabu Moger	  some x86 processors. If enabled, a general protection fault is
1843b971880fSBabu Moger	  issued if the SGDT, SLDT, SIDT, SMSW or STR instructions are
1844b971880fSBabu Moger	  executed in user mode. These instructions unnecessarily expose
1845b971880fSBabu Moger	  information about the hardware state.
1846796ebc81SRicardo Neri
1847796ebc81SRicardo Neri	  The vast majority of applications do not use these instructions.
1848796ebc81SRicardo Neri	  For the very few that do, software emulation is provided in
1849796ebc81SRicardo Neri	  specific cases in protected and virtual-8086 modes. Emulated
1850796ebc81SRicardo Neri	  results are dummy.
1851aa35f896SRicardo Neri
185235e97790SDave Hansenconfig X86_INTEL_MEMORY_PROTECTION_KEYS
185338f3e775SBabu Moger	prompt "Memory Protection Keys"
185435e97790SDave Hansen	def_bool y
1855284244a9SDave Hansen	# Note: only available in 64-bit mode
185638f3e775SBabu Moger	depends on X86_64 && (CPU_SUP_INTEL || CPU_SUP_AMD)
185752c8e601SIngo Molnar	select ARCH_USES_HIGH_VMA_FLAGS
185852c8e601SIngo Molnar	select ARCH_HAS_PKEYS
1859a7f7f624SMasahiro Yamada	help
1860284244a9SDave Hansen	  Memory Protection Keys provides a mechanism for enforcing
1861284244a9SDave Hansen	  page-based protections, but without requiring modification of the
1862284244a9SDave Hansen	  page tables when an application changes protection domains.
1863284244a9SDave Hansen
18641eecbcdcSMauro Carvalho Chehab	  For details, see Documentation/core-api/protection-keys.rst
1865284244a9SDave Hansen
1866284244a9SDave Hansen	  If unsure, say y.
186735e97790SDave Hansen
1868db616173SMichal Hockochoice
1869db616173SMichal Hocko	prompt "TSX enable mode"
1870db616173SMichal Hocko	depends on CPU_SUP_INTEL
1871db616173SMichal Hocko	default X86_INTEL_TSX_MODE_OFF
1872db616173SMichal Hocko	help
1873db616173SMichal Hocko	  Intel's TSX (Transactional Synchronization Extensions) feature
1874db616173SMichal Hocko	  allows to optimize locking protocols through lock elision which
1875db616173SMichal Hocko	  can lead to a noticeable performance boost.
1876db616173SMichal Hocko
1877db616173SMichal Hocko	  On the other hand it has been shown that TSX can be exploited
1878db616173SMichal Hocko	  to form side channel attacks (e.g. TAA) and chances are there
1879db616173SMichal Hocko	  will be more of those attacks discovered in the future.
1880db616173SMichal Hocko
1881db616173SMichal Hocko	  Therefore TSX is not enabled by default (aka tsx=off). An admin
1882db616173SMichal Hocko	  might override this decision by tsx=on the command line parameter.
1883db616173SMichal Hocko	  Even with TSX enabled, the kernel will attempt to enable the best
1884db616173SMichal Hocko	  possible TAA mitigation setting depending on the microcode available
1885db616173SMichal Hocko	  for the particular machine.
1886db616173SMichal Hocko
1887db616173SMichal Hocko	  This option allows to set the default tsx mode between tsx=on, =off
1888db616173SMichal Hocko	  and =auto. See Documentation/admin-guide/kernel-parameters.txt for more
1889db616173SMichal Hocko	  details.
1890db616173SMichal Hocko
1891db616173SMichal Hocko	  Say off if not sure, auto if TSX is in use but it should be used on safe
1892db616173SMichal Hocko	  platforms or on if TSX is in use and the security aspect of tsx is not
1893db616173SMichal Hocko	  relevant.
1894db616173SMichal Hocko
1895db616173SMichal Hockoconfig X86_INTEL_TSX_MODE_OFF
1896db616173SMichal Hocko	bool "off"
1897db616173SMichal Hocko	help
1898db616173SMichal Hocko	  TSX is disabled if possible - equals to tsx=off command line parameter.
1899db616173SMichal Hocko
1900db616173SMichal Hockoconfig X86_INTEL_TSX_MODE_ON
1901db616173SMichal Hocko	bool "on"
1902db616173SMichal Hocko	help
1903db616173SMichal Hocko	  TSX is always enabled on TSX capable HW - equals the tsx=on command
1904db616173SMichal Hocko	  line parameter.
1905db616173SMichal Hocko
1906db616173SMichal Hockoconfig X86_INTEL_TSX_MODE_AUTO
1907db616173SMichal Hocko	bool "auto"
1908db616173SMichal Hocko	help
1909db616173SMichal Hocko	  TSX is enabled on TSX capable HW that is believed to be safe against
1910db616173SMichal Hocko	  side channel attacks- equals the tsx=auto command line parameter.
1911db616173SMichal Hockoendchoice
1912db616173SMichal Hocko
1913e7e05452SSean Christophersonconfig X86_SGX
1914e7e05452SSean Christopherson	bool "Software Guard eXtensions (SGX)"
1915e7e05452SSean Christopherson	depends on X86_64 && CPU_SUP_INTEL
1916e7e05452SSean Christopherson	depends on CRYPTO=y
1917e7e05452SSean Christopherson	depends on CRYPTO_SHA256=y
1918e7e05452SSean Christopherson	select SRCU
1919e7e05452SSean Christopherson	select MMU_NOTIFIER
1920901ddbb9SJarkko Sakkinen	select NUMA_KEEP_MEMINFO if NUMA
192140e0e784STony Luck	select XARRAY_MULTI
1922e7e05452SSean Christopherson	help
1923e7e05452SSean Christopherson	  Intel(R) Software Guard eXtensions (SGX) is a set of CPU instructions
1924e7e05452SSean Christopherson	  that can be used by applications to set aside private regions of code
1925e7e05452SSean Christopherson	  and data, referred to as enclaves. An enclave's private memory can
1926e7e05452SSean Christopherson	  only be accessed by code running within the enclave. Accesses from
1927e7e05452SSean Christopherson	  outside the enclave, including other enclaves, are disallowed by
1928e7e05452SSean Christopherson	  hardware.
1929e7e05452SSean Christopherson
1930e7e05452SSean Christopherson	  If unsure, say N.
1931e7e05452SSean Christopherson
1932506f1d07SSam Ravnborgconfig EFI
19339ba16087SJan Beulich	bool "EFI runtime service support"
19345b83683fSHuang, Ying	depends on ACPI
1935f6ce5002SSergey Vlasov	select UCS2_STRING
1936022ee6c5SArd Biesheuvel	select EFI_RUNTIME_WRAPPERS
1937a7f7f624SMasahiro Yamada	help
19388b2cb7a8SHuang, Ying	  This enables the kernel to use EFI runtime services that are
1939506f1d07SSam Ravnborg	  available (such as the EFI variable services).
1940506f1d07SSam Ravnborg
19418b2cb7a8SHuang, Ying	  This option is only useful on systems that have EFI firmware.
19428b2cb7a8SHuang, Ying	  In addition, you should use the latest ELILO loader available
19438b2cb7a8SHuang, Ying	  at <http://elilo.sourceforge.net> in order to take advantage
19448b2cb7a8SHuang, Ying	  of EFI runtime services. However, even with this option, the
19458b2cb7a8SHuang, Ying	  resultant kernel should continue to boot on existing non-EFI
19468b2cb7a8SHuang, Ying	  platforms.
1947506f1d07SSam Ravnborg
1948291f3632SMatt Flemingconfig EFI_STUB
1949291f3632SMatt Fleming	bool "EFI stub support"
1950b16d8c23SMatt Fleming	depends on EFI && !X86_USE_3DNOW
19518f24f8c2SArd Biesheuvel	depends on $(cc-option,-mabi=ms) || X86_32
19527b2a583aSMatt Fleming	select RELOCATABLE
1953a7f7f624SMasahiro Yamada	help
1954291f3632SMatt Fleming	  This kernel feature allows a bzImage to be loaded directly
1955291f3632SMatt Fleming	  by EFI firmware without the use of a bootloader.
1956291f3632SMatt Fleming
19574f4cfa6cSMauro Carvalho Chehab	  See Documentation/admin-guide/efi-stub.rst for more information.
19580c759662SMatt Fleming
19597d453eeeSMatt Flemingconfig EFI_MIXED
19607d453eeeSMatt Fleming	bool "EFI mixed-mode support"
19617d453eeeSMatt Fleming	depends on EFI_STUB && X86_64
1962a7f7f624SMasahiro Yamada	help
19637d453eeeSMatt Fleming	   Enabling this feature allows a 64-bit kernel to be booted
19647d453eeeSMatt Fleming	   on a 32-bit firmware, provided that your CPU supports 64-bit
19657d453eeeSMatt Fleming	   mode.
19667d453eeeSMatt Fleming
19677d453eeeSMatt Fleming	   Note that it is not possible to boot a mixed-mode enabled
19687d453eeeSMatt Fleming	   kernel via the EFI boot stub - a bootloader that supports
19697d453eeeSMatt Fleming	   the EFI handover protocol must be used.
19707d453eeeSMatt Fleming
19717d453eeeSMatt Fleming	   If unsure, say N.
19727d453eeeSMatt Fleming
19738636a1f9SMasahiro Yamadasource "kernel/Kconfig.hz"
1974506f1d07SSam Ravnborg
1975506f1d07SSam Ravnborgconfig KEXEC
1976506f1d07SSam Ravnborg	bool "kexec system call"
19772965faa5SDave Young	select KEXEC_CORE
1978a7f7f624SMasahiro Yamada	help
1979506f1d07SSam Ravnborg	  kexec is a system call that implements the ability to shutdown your
1980506f1d07SSam Ravnborg	  current kernel, and to start another kernel.  It is like a reboot
1981506f1d07SSam Ravnborg	  but it is independent of the system firmware.   And like a reboot
1982506f1d07SSam Ravnborg	  you can start any kernel with it, not just Linux.
1983506f1d07SSam Ravnborg
1984506f1d07SSam Ravnborg	  The name comes from the similarity to the exec system call.
1985506f1d07SSam Ravnborg
1986506f1d07SSam Ravnborg	  It is an ongoing process to be certain the hardware in a machine
1987506f1d07SSam Ravnborg	  is properly shutdown, so do not be surprised if this code does not
1988bf220695SGeert Uytterhoeven	  initially work for you.  As of this writing the exact hardware
1989bf220695SGeert Uytterhoeven	  interface is strongly in flux, so no good recommendation can be
1990bf220695SGeert Uytterhoeven	  made.
1991506f1d07SSam Ravnborg
199274ca317cSVivek Goyalconfig KEXEC_FILE
199374ca317cSVivek Goyal	bool "kexec file based system call"
19942965faa5SDave Young	select KEXEC_CORE
199574ca317cSVivek Goyal	select BUILD_BIN2C
199674ca317cSVivek Goyal	depends on X86_64
199774ca317cSVivek Goyal	depends on CRYPTO=y
199874ca317cSVivek Goyal	depends on CRYPTO_SHA256=y
1999a7f7f624SMasahiro Yamada	help
200074ca317cSVivek Goyal	  This is new version of kexec system call. This system call is
200174ca317cSVivek Goyal	  file based and takes file descriptors as system call argument
200274ca317cSVivek Goyal	  for kernel and initramfs as opposed to list of segments as
200374ca317cSVivek Goyal	  accepted by previous system call.
200474ca317cSVivek Goyal
2005b799a09fSAKASHI Takahiroconfig ARCH_HAS_KEXEC_PURGATORY
2006b799a09fSAKASHI Takahiro	def_bool KEXEC_FILE
2007b799a09fSAKASHI Takahiro
200899d5cadfSJiri Bohacconfig KEXEC_SIG
20098e7d8381SVivek Goyal	bool "Verify kernel signature during kexec_file_load() syscall"
201074ca317cSVivek Goyal	depends on KEXEC_FILE
2011a7f7f624SMasahiro Yamada	help
201299d5cadfSJiri Bohac
201399d5cadfSJiri Bohac	  This option makes the kexec_file_load() syscall check for a valid
201499d5cadfSJiri Bohac	  signature of the kernel image.  The image can still be loaded without
201599d5cadfSJiri Bohac	  a valid signature unless you also enable KEXEC_SIG_FORCE, though if
201699d5cadfSJiri Bohac	  there's a signature that we can check, then it must be valid.
201799d5cadfSJiri Bohac
201899d5cadfSJiri Bohac	  In addition to this option, you need to enable signature
201999d5cadfSJiri Bohac	  verification for the corresponding kernel image type being
202099d5cadfSJiri Bohac	  loaded in order for this to work.
202199d5cadfSJiri Bohac
202299d5cadfSJiri Bohacconfig KEXEC_SIG_FORCE
202399d5cadfSJiri Bohac	bool "Require a valid signature in kexec_file_load() syscall"
202499d5cadfSJiri Bohac	depends on KEXEC_SIG
2025a7f7f624SMasahiro Yamada	help
20268e7d8381SVivek Goyal	  This option makes kernel signature verification mandatory for
2027d8eb8940SBorislav Petkov	  the kexec_file_load() syscall.
20288e7d8381SVivek Goyal
20298e7d8381SVivek Goyalconfig KEXEC_BZIMAGE_VERIFY_SIG
20308e7d8381SVivek Goyal	bool "Enable bzImage signature verification support"
203199d5cadfSJiri Bohac	depends on KEXEC_SIG
20328e7d8381SVivek Goyal	depends on SIGNED_PE_FILE_VERIFICATION
20338e7d8381SVivek Goyal	select SYSTEM_TRUSTED_KEYRING
2034a7f7f624SMasahiro Yamada	help
20358e7d8381SVivek Goyal	  Enable bzImage signature verification support.
20368e7d8381SVivek Goyal
2037506f1d07SSam Ravnborgconfig CRASH_DUMP
203804b69447SPavel Machek	bool "kernel crash dumps"
2039506f1d07SSam Ravnborg	depends on X86_64 || (X86_32 && HIGHMEM)
2040a7f7f624SMasahiro Yamada	help
2041506f1d07SSam Ravnborg	  Generate crash dump after being started by kexec.
2042506f1d07SSam Ravnborg	  This should be normally only set in special crash dump kernels
2043506f1d07SSam Ravnborg	  which are loaded in the main kernel with kexec-tools into
2044506f1d07SSam Ravnborg	  a specially reserved region and then later executed after
2045506f1d07SSam Ravnborg	  a crash by kdump/kexec. The crash dump kernel must be compiled
2046506f1d07SSam Ravnborg	  to a memory address not used by the main kernel or BIOS using
2047506f1d07SSam Ravnborg	  PHYSICAL_START, or it must be built as a relocatable image
2048506f1d07SSam Ravnborg	  (CONFIG_RELOCATABLE=y).
2049330d4810SMauro Carvalho Chehab	  For more details see Documentation/admin-guide/kdump/kdump.rst
2050506f1d07SSam Ravnborg
20513ab83521SHuang Yingconfig KEXEC_JUMP
20526ea30386SKees Cook	bool "kexec jump"
2053fee7b0d8SHuang Ying	depends on KEXEC && HIBERNATION
2054a7f7f624SMasahiro Yamada	help
205589081d17SHuang Ying	  Jump between original kernel and kexeced kernel and invoke
205689081d17SHuang Ying	  code in physical address mode via KEXEC
20573ab83521SHuang Ying
2058506f1d07SSam Ravnborgconfig PHYSICAL_START
20596a108a14SDavid Rientjes	hex "Physical address where the kernel is loaded" if (EXPERT || CRASH_DUMP)
2060ceefccc9SH. Peter Anvin	default "0x1000000"
2061a7f7f624SMasahiro Yamada	help
2062506f1d07SSam Ravnborg	  This gives the physical address where the kernel is loaded.
2063506f1d07SSam Ravnborg
2064506f1d07SSam Ravnborg	  If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then
2065506f1d07SSam Ravnborg	  bzImage will decompress itself to above physical address and
2066506f1d07SSam Ravnborg	  run from there. Otherwise, bzImage will run from the address where
2067506f1d07SSam Ravnborg	  it has been loaded by the boot loader and will ignore above physical
2068506f1d07SSam Ravnborg	  address.
2069506f1d07SSam Ravnborg
2070506f1d07SSam Ravnborg	  In normal kdump cases one does not have to set/change this option
2071506f1d07SSam Ravnborg	  as now bzImage can be compiled as a completely relocatable image
2072506f1d07SSam Ravnborg	  (CONFIG_RELOCATABLE=y) and be used to load and run from a different
2073506f1d07SSam Ravnborg	  address. This option is mainly useful for the folks who don't want
2074506f1d07SSam Ravnborg	  to use a bzImage for capturing the crash dump and want to use a
2075506f1d07SSam Ravnborg	  vmlinux instead. vmlinux is not relocatable hence a kernel needs
2076506f1d07SSam Ravnborg	  to be specifically compiled to run from a specific memory area
2077506f1d07SSam Ravnborg	  (normally a reserved region) and this option comes handy.
2078506f1d07SSam Ravnborg
2079ceefccc9SH. Peter Anvin	  So if you are using bzImage for capturing the crash dump,
2080ceefccc9SH. Peter Anvin	  leave the value here unchanged to 0x1000000 and set
2081ceefccc9SH. Peter Anvin	  CONFIG_RELOCATABLE=y.  Otherwise if you plan to use vmlinux
2082ceefccc9SH. Peter Anvin	  for capturing the crash dump change this value to start of
2083ceefccc9SH. Peter Anvin	  the reserved region.  In other words, it can be set based on
2084ceefccc9SH. Peter Anvin	  the "X" value as specified in the "crashkernel=YM@XM"
2085ceefccc9SH. Peter Anvin	  command line boot parameter passed to the panic-ed
2086330d4810SMauro Carvalho Chehab	  kernel. Please take a look at Documentation/admin-guide/kdump/kdump.rst
2087ceefccc9SH. Peter Anvin	  for more details about crash dumps.
2088506f1d07SSam Ravnborg
2089506f1d07SSam Ravnborg	  Usage of bzImage for capturing the crash dump is recommended as
2090506f1d07SSam Ravnborg	  one does not have to build two kernels. Same kernel can be used
2091506f1d07SSam Ravnborg	  as production kernel and capture kernel. Above option should have
2092506f1d07SSam Ravnborg	  gone away after relocatable bzImage support is introduced. But it
2093506f1d07SSam Ravnborg	  is present because there are users out there who continue to use
2094506f1d07SSam Ravnborg	  vmlinux for dump capture. This option should go away down the
2095506f1d07SSam Ravnborg	  line.
2096506f1d07SSam Ravnborg
2097506f1d07SSam Ravnborg	  Don't change this unless you know what you are doing.
2098506f1d07SSam Ravnborg
2099506f1d07SSam Ravnborgconfig RELOCATABLE
210026717808SH. Peter Anvin	bool "Build a relocatable kernel"
210126717808SH. Peter Anvin	default y
2102a7f7f624SMasahiro Yamada	help
2103506f1d07SSam Ravnborg	  This builds a kernel image that retains relocation information
2104506f1d07SSam Ravnborg	  so it can be loaded someplace besides the default 1MB.
2105506f1d07SSam Ravnborg	  The relocations tend to make the kernel binary about 10% larger,
2106506f1d07SSam Ravnborg	  but are discarded at runtime.
2107506f1d07SSam Ravnborg
2108506f1d07SSam Ravnborg	  One use is for the kexec on panic case where the recovery kernel
2109506f1d07SSam Ravnborg	  must live at a different physical address than the primary
2110506f1d07SSam Ravnborg	  kernel.
2111506f1d07SSam Ravnborg
2112506f1d07SSam Ravnborg	  Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address
2113506f1d07SSam Ravnborg	  it has been loaded at and the compile time physical address
21148ab3820fSKees Cook	  (CONFIG_PHYSICAL_START) is used as the minimum location.
2115506f1d07SSam Ravnborg
21168ab3820fSKees Cookconfig RANDOMIZE_BASE
2117e8581e3dSBaoquan He	bool "Randomize the address of the kernel image (KASLR)"
21188ab3820fSKees Cook	depends on RELOCATABLE
21196807c846SIngo Molnar	default y
2120a7f7f624SMasahiro Yamada	help
2121e8581e3dSBaoquan He	  In support of Kernel Address Space Layout Randomization (KASLR),
2122e8581e3dSBaoquan He	  this randomizes the physical address at which the kernel image
2123e8581e3dSBaoquan He	  is decompressed and the virtual address where the kernel
2124e8581e3dSBaoquan He	  image is mapped, as a security feature that deters exploit
2125e8581e3dSBaoquan He	  attempts relying on knowledge of the location of kernel
2126e8581e3dSBaoquan He	  code internals.
2127e8581e3dSBaoquan He
2128ed9f007eSKees Cook	  On 64-bit, the kernel physical and virtual addresses are
2129ed9f007eSKees Cook	  randomized separately. The physical address will be anywhere
2130ed9f007eSKees Cook	  between 16MB and the top of physical memory (up to 64TB). The
2131ed9f007eSKees Cook	  virtual address will be randomized from 16MB up to 1GB (9 bits
2132ed9f007eSKees Cook	  of entropy). Note that this also reduces the memory space
2133ed9f007eSKees Cook	  available to kernel modules from 1.5GB to 1GB.
2134ed9f007eSKees Cook
2135ed9f007eSKees Cook	  On 32-bit, the kernel physical and virtual addresses are
2136ed9f007eSKees Cook	  randomized together. They will be randomized from 16MB up to
2137ed9f007eSKees Cook	  512MB (8 bits of entropy).
21388ab3820fSKees Cook
2139a653f356SKees Cook	  Entropy is generated using the RDRAND instruction if it is
2140e8581e3dSBaoquan He	  supported. If RDTSC is supported, its value is mixed into
2141e8581e3dSBaoquan He	  the entropy pool as well. If neither RDRAND nor RDTSC are
2142ed9f007eSKees Cook	  supported, then entropy is read from the i8254 timer. The
2143ed9f007eSKees Cook	  usable entropy is limited by the kernel being built using
2144ed9f007eSKees Cook	  2GB addressing, and that PHYSICAL_ALIGN must be at a
2145ed9f007eSKees Cook	  minimum of 2MB. As a result, only 10 bits of entropy are
2146ed9f007eSKees Cook	  theoretically possible, but the implementations are further
2147ed9f007eSKees Cook	  limited due to memory layouts.
2148e8581e3dSBaoquan He
21496807c846SIngo Molnar	  If unsure, say Y.
2150da2b6fb9SKees Cook
21518ab3820fSKees Cook# Relocation on x86 needs some additional build support
2152845adf72SH. Peter Anvinconfig X86_NEED_RELOCS
2153845adf72SH. Peter Anvin	def_bool y
21548ab3820fSKees Cook	depends on RANDOMIZE_BASE || (X86_32 && RELOCATABLE)
2155845adf72SH. Peter Anvin
2156506f1d07SSam Ravnborgconfig PHYSICAL_ALIGN
2157a0215061SKees Cook	hex "Alignment value to which kernel should be aligned"
21588ab3820fSKees Cook	default "0x200000"
2159a0215061SKees Cook	range 0x2000 0x1000000 if X86_32
2160a0215061SKees Cook	range 0x200000 0x1000000 if X86_64
2161a7f7f624SMasahiro Yamada	help
2162506f1d07SSam Ravnborg	  This value puts the alignment restrictions on physical address
2163506f1d07SSam Ravnborg	  where kernel is loaded and run from. Kernel is compiled for an
2164506f1d07SSam Ravnborg	  address which meets above alignment restriction.
2165506f1d07SSam Ravnborg
2166506f1d07SSam Ravnborg	  If bootloader loads the kernel at a non-aligned address and
2167506f1d07SSam Ravnborg	  CONFIG_RELOCATABLE is set, kernel will move itself to nearest
2168506f1d07SSam Ravnborg	  address aligned to above value and run from there.
2169506f1d07SSam Ravnborg
2170506f1d07SSam Ravnborg	  If bootloader loads the kernel at a non-aligned address and
2171506f1d07SSam Ravnborg	  CONFIG_RELOCATABLE is not set, kernel will ignore the run time
2172506f1d07SSam Ravnborg	  load address and decompress itself to the address it has been
2173506f1d07SSam Ravnborg	  compiled for and run from there. The address for which kernel is
2174506f1d07SSam Ravnborg	  compiled already meets above alignment restrictions. Hence the
2175506f1d07SSam Ravnborg	  end result is that kernel runs from a physical address meeting
2176506f1d07SSam Ravnborg	  above alignment restrictions.
2177506f1d07SSam Ravnborg
2178a0215061SKees Cook	  On 32-bit this value must be a multiple of 0x2000. On 64-bit
2179a0215061SKees Cook	  this value must be a multiple of 0x200000.
2180a0215061SKees Cook
2181506f1d07SSam Ravnborg	  Don't change this unless you know what you are doing.
2182506f1d07SSam Ravnborg
2183eedb92abSKirill A. Shutemovconfig DYNAMIC_MEMORY_LAYOUT
2184eedb92abSKirill A. Shutemov	bool
2185a7f7f624SMasahiro Yamada	help
2186eedb92abSKirill A. Shutemov	  This option makes base addresses of vmalloc and vmemmap as well as
2187eedb92abSKirill A. Shutemov	  __PAGE_OFFSET movable during boot.
2188eedb92abSKirill A. Shutemov
21890483e1faSThomas Garnierconfig RANDOMIZE_MEMORY
21900483e1faSThomas Garnier	bool "Randomize the kernel memory sections"
21910483e1faSThomas Garnier	depends on X86_64
21920483e1faSThomas Garnier	depends on RANDOMIZE_BASE
2193eedb92abSKirill A. Shutemov	select DYNAMIC_MEMORY_LAYOUT
21940483e1faSThomas Garnier	default RANDOMIZE_BASE
2195a7f7f624SMasahiro Yamada	help
21960483e1faSThomas Garnier	   Randomizes the base virtual address of kernel memory sections
21970483e1faSThomas Garnier	   (physical memory mapping, vmalloc & vmemmap). This security feature
21980483e1faSThomas Garnier	   makes exploits relying on predictable memory locations less reliable.
21990483e1faSThomas Garnier
22000483e1faSThomas Garnier	   The order of allocations remains unchanged. Entropy is generated in
22010483e1faSThomas Garnier	   the same way as RANDOMIZE_BASE. Current implementation in the optimal
22020483e1faSThomas Garnier	   configuration have in average 30,000 different possible virtual
22030483e1faSThomas Garnier	   addresses for each memory section.
22040483e1faSThomas Garnier
22056807c846SIngo Molnar	   If unsure, say Y.
22060483e1faSThomas Garnier
220790397a41SThomas Garnierconfig RANDOMIZE_MEMORY_PHYSICAL_PADDING
220890397a41SThomas Garnier	hex "Physical memory mapping padding" if EXPERT
220990397a41SThomas Garnier	depends on RANDOMIZE_MEMORY
221090397a41SThomas Garnier	default "0xa" if MEMORY_HOTPLUG
221190397a41SThomas Garnier	default "0x0"
221290397a41SThomas Garnier	range 0x1 0x40 if MEMORY_HOTPLUG
221390397a41SThomas Garnier	range 0x0 0x40
2214a7f7f624SMasahiro Yamada	help
221590397a41SThomas Garnier	   Define the padding in terabytes added to the existing physical
221690397a41SThomas Garnier	   memory size during kernel memory randomization. It is useful
221790397a41SThomas Garnier	   for memory hotplug support but reduces the entropy available for
221890397a41SThomas Garnier	   address randomization.
221990397a41SThomas Garnier
222090397a41SThomas Garnier	   If unsure, leave at the default value.
222190397a41SThomas Garnier
2222506f1d07SSam Ravnborgconfig HOTPLUG_CPU
2223bebd024eSThomas Gleixner	def_bool y
222440b31360SStephen Rothwell	depends on SMP
2225506f1d07SSam Ravnborg
222680aa1dffSFenghua Yuconfig BOOTPARAM_HOTPLUG_CPU0
222780aa1dffSFenghua Yu	bool "Set default setting of cpu0_hotpluggable"
22282c922cd0SKees Cook	depends on HOTPLUG_CPU
2229a7f7f624SMasahiro Yamada	help
223080aa1dffSFenghua Yu	  Set whether default state of cpu0_hotpluggable is on or off.
223180aa1dffSFenghua Yu
223280aa1dffSFenghua Yu	  Say Y here to enable CPU0 hotplug by default. If this switch
223380aa1dffSFenghua Yu	  is turned on, there is no need to give cpu0_hotplug kernel
223480aa1dffSFenghua Yu	  parameter and the CPU0 hotplug feature is enabled by default.
223580aa1dffSFenghua Yu
223680aa1dffSFenghua Yu	  Please note: there are two known CPU0 dependencies if you want
223780aa1dffSFenghua Yu	  to enable the CPU0 hotplug feature either by this switch or by
223880aa1dffSFenghua Yu	  cpu0_hotplug kernel parameter.
223980aa1dffSFenghua Yu
224080aa1dffSFenghua Yu	  First, resume from hibernate or suspend always starts from CPU0.
224180aa1dffSFenghua Yu	  So hibernate and suspend are prevented if CPU0 is offline.
224280aa1dffSFenghua Yu
224380aa1dffSFenghua Yu	  Second dependency is PIC interrupts always go to CPU0. CPU0 can not
224480aa1dffSFenghua Yu	  offline if any interrupt can not migrate out of CPU0. There may
224580aa1dffSFenghua Yu	  be other CPU0 dependencies.
224680aa1dffSFenghua Yu
224780aa1dffSFenghua Yu	  Please make sure the dependencies are under your control before
224880aa1dffSFenghua Yu	  you enable this feature.
224980aa1dffSFenghua Yu
225080aa1dffSFenghua Yu	  Say N if you don't want to enable CPU0 hotplug feature by default.
225180aa1dffSFenghua Yu	  You still can enable the CPU0 hotplug feature at boot by kernel
225280aa1dffSFenghua Yu	  parameter cpu0_hotplug.
225380aa1dffSFenghua Yu
2254a71c8bc5SFenghua Yuconfig DEBUG_HOTPLUG_CPU0
2255a71c8bc5SFenghua Yu	def_bool n
2256a71c8bc5SFenghua Yu	prompt "Debug CPU0 hotplug"
22572c922cd0SKees Cook	depends on HOTPLUG_CPU
2258a7f7f624SMasahiro Yamada	help
2259a71c8bc5SFenghua Yu	  Enabling this option offlines CPU0 (if CPU0 can be offlined) as
2260a71c8bc5SFenghua Yu	  soon as possible and boots up userspace with CPU0 offlined. User
2261a71c8bc5SFenghua Yu	  can online CPU0 back after boot time.
2262a71c8bc5SFenghua Yu
2263a71c8bc5SFenghua Yu	  To debug CPU0 hotplug, you need to enable CPU0 offline/online
2264a71c8bc5SFenghua Yu	  feature by either turning on CONFIG_BOOTPARAM_HOTPLUG_CPU0 during
2265a71c8bc5SFenghua Yu	  compilation or giving cpu0_hotplug kernel parameter at boot.
2266a71c8bc5SFenghua Yu
2267a71c8bc5SFenghua Yu	  If unsure, say N.
2268a71c8bc5SFenghua Yu
2269506f1d07SSam Ravnborgconfig COMPAT_VDSO
2270b0b49f26SAndy Lutomirski	def_bool n
2271b0b49f26SAndy Lutomirski	prompt "Disable the 32-bit vDSO (needed for glibc 2.3.3)"
2272953fee1dSIngo Molnar	depends on COMPAT_32
2273a7f7f624SMasahiro Yamada	help
2274b0b49f26SAndy Lutomirski	  Certain buggy versions of glibc will crash if they are
2275b0b49f26SAndy Lutomirski	  presented with a 32-bit vDSO that is not mapped at the address
2276b0b49f26SAndy Lutomirski	  indicated in its segment table.
2277e84446deSRandy Dunlap
2278b0b49f26SAndy Lutomirski	  The bug was introduced by f866314b89d56845f55e6f365e18b31ec978ec3a
2279b0b49f26SAndy Lutomirski	  and fixed by 3b3ddb4f7db98ec9e912ccdf54d35df4aa30e04a and
2280b0b49f26SAndy Lutomirski	  49ad572a70b8aeb91e57483a11dd1b77e31c4468.  Glibc 2.3.3 is
2281b0b49f26SAndy Lutomirski	  the only released version with the bug, but OpenSUSE 9
2282b0b49f26SAndy Lutomirski	  contains a buggy "glibc 2.3.2".
2283506f1d07SSam Ravnborg
2284b0b49f26SAndy Lutomirski	  The symptom of the bug is that everything crashes on startup, saying:
2285b0b49f26SAndy Lutomirski	  dl_main: Assertion `(void *) ph->p_vaddr == _rtld_local._dl_sysinfo_dso' failed!
2286b0b49f26SAndy Lutomirski
2287b0b49f26SAndy Lutomirski	  Saying Y here changes the default value of the vdso32 boot
2288b0b49f26SAndy Lutomirski	  option from 1 to 0, which turns off the 32-bit vDSO entirely.
2289b0b49f26SAndy Lutomirski	  This works around the glibc bug but hurts performance.
2290b0b49f26SAndy Lutomirski
2291b0b49f26SAndy Lutomirski	  If unsure, say N: if you are compiling your own kernel, you
2292b0b49f26SAndy Lutomirski	  are unlikely to be using a buggy version of glibc.
2293506f1d07SSam Ravnborg
22943dc33bd3SKees Cookchoice
22953dc33bd3SKees Cook	prompt "vsyscall table for legacy applications"
22963dc33bd3SKees Cook	depends on X86_64
2297625b7b7fSAndy Lutomirski	default LEGACY_VSYSCALL_XONLY
22983dc33bd3SKees Cook	help
22993dc33bd3SKees Cook	  Legacy user code that does not know how to find the vDSO expects
23003dc33bd3SKees Cook	  to be able to issue three syscalls by calling fixed addresses in
23013dc33bd3SKees Cook	  kernel space. Since this location is not randomized with ASLR,
23023dc33bd3SKees Cook	  it can be used to assist security vulnerability exploitation.
23033dc33bd3SKees Cook
23043dc33bd3SKees Cook	  This setting can be changed at boot time via the kernel command
2305bd49e16eSAndy Lutomirski	  line parameter vsyscall=[emulate|xonly|none].
23063dc33bd3SKees Cook
23073dc33bd3SKees Cook	  On a system with recent enough glibc (2.14 or newer) and no
23083dc33bd3SKees Cook	  static binaries, you can say None without a performance penalty
23093dc33bd3SKees Cook	  to improve security.
23103dc33bd3SKees Cook
2311bd49e16eSAndy Lutomirski	  If unsure, select "Emulate execution only".
23123dc33bd3SKees Cook
23133dc33bd3SKees Cook	config LEGACY_VSYSCALL_EMULATE
2314bd49e16eSAndy Lutomirski		bool "Full emulation"
23153dc33bd3SKees Cook		help
2316bd49e16eSAndy Lutomirski		  The kernel traps and emulates calls into the fixed vsyscall
2317bd49e16eSAndy Lutomirski		  address mapping. This makes the mapping non-executable, but
2318bd49e16eSAndy Lutomirski		  it still contains readable known contents, which could be
2319bd49e16eSAndy Lutomirski		  used in certain rare security vulnerability exploits. This
2320bd49e16eSAndy Lutomirski		  configuration is recommended when using legacy userspace
2321bd49e16eSAndy Lutomirski		  that still uses vsyscalls along with legacy binary
2322bd49e16eSAndy Lutomirski		  instrumentation tools that require code to be readable.
2323bd49e16eSAndy Lutomirski
2324bd49e16eSAndy Lutomirski		  An example of this type of legacy userspace is running
2325bd49e16eSAndy Lutomirski		  Pin on an old binary that still uses vsyscalls.
2326bd49e16eSAndy Lutomirski
2327bd49e16eSAndy Lutomirski	config LEGACY_VSYSCALL_XONLY
2328bd49e16eSAndy Lutomirski		bool "Emulate execution only"
2329bd49e16eSAndy Lutomirski		help
2330bd49e16eSAndy Lutomirski		  The kernel traps and emulates calls into the fixed vsyscall
2331bd49e16eSAndy Lutomirski		  address mapping and does not allow reads.  This
2332bd49e16eSAndy Lutomirski		  configuration is recommended when userspace might use the
2333bd49e16eSAndy Lutomirski		  legacy vsyscall area but support for legacy binary
2334bd49e16eSAndy Lutomirski		  instrumentation of legacy code is not needed.  It mitigates
2335bd49e16eSAndy Lutomirski		  certain uses of the vsyscall area as an ASLR-bypassing
2336bd49e16eSAndy Lutomirski		  buffer.
23373dc33bd3SKees Cook
23383dc33bd3SKees Cook	config LEGACY_VSYSCALL_NONE
23393dc33bd3SKees Cook		bool "None"
23403dc33bd3SKees Cook		help
23413dc33bd3SKees Cook		  There will be no vsyscall mapping at all. This will
23423dc33bd3SKees Cook		  eliminate any risk of ASLR bypass due to the vsyscall
23433dc33bd3SKees Cook		  fixed address mapping. Attempts to use the vsyscalls
23443dc33bd3SKees Cook		  will be reported to dmesg, so that either old or
23453dc33bd3SKees Cook		  malicious userspace programs can be identified.
23463dc33bd3SKees Cook
23473dc33bd3SKees Cookendchoice
23483dc33bd3SKees Cook
2349516cbf37STim Birdconfig CMDLINE_BOOL
2350516cbf37STim Bird	bool "Built-in kernel command line"
2351a7f7f624SMasahiro Yamada	help
2352516cbf37STim Bird	  Allow for specifying boot arguments to the kernel at
2353516cbf37STim Bird	  build time.  On some systems (e.g. embedded ones), it is
2354516cbf37STim Bird	  necessary or convenient to provide some or all of the
2355516cbf37STim Bird	  kernel boot arguments with the kernel itself (that is,
2356516cbf37STim Bird	  to not rely on the boot loader to provide them.)
2357516cbf37STim Bird
2358516cbf37STim Bird	  To compile command line arguments into the kernel,
2359516cbf37STim Bird	  set this option to 'Y', then fill in the
236069711ca1SSébastien Hinderer	  boot arguments in CONFIG_CMDLINE.
2361516cbf37STim Bird
2362516cbf37STim Bird	  Systems with fully functional boot loaders (i.e. non-embedded)
2363516cbf37STim Bird	  should leave this option set to 'N'.
2364516cbf37STim Bird
2365516cbf37STim Birdconfig CMDLINE
2366516cbf37STim Bird	string "Built-in kernel command string"
2367516cbf37STim Bird	depends on CMDLINE_BOOL
2368516cbf37STim Bird	default ""
2369a7f7f624SMasahiro Yamada	help
2370516cbf37STim Bird	  Enter arguments here that should be compiled into the kernel
2371516cbf37STim Bird	  image and used at boot time.  If the boot loader provides a
2372516cbf37STim Bird	  command line at boot time, it is appended to this string to
2373516cbf37STim Bird	  form the full kernel command line, when the system boots.
2374516cbf37STim Bird
2375516cbf37STim Bird	  However, you can use the CONFIG_CMDLINE_OVERRIDE option to
2376516cbf37STim Bird	  change this behavior.
2377516cbf37STim Bird
2378516cbf37STim Bird	  In most cases, the command line (whether built-in or provided
2379516cbf37STim Bird	  by the boot loader) should specify the device for the root
2380516cbf37STim Bird	  file system.
2381516cbf37STim Bird
2382516cbf37STim Birdconfig CMDLINE_OVERRIDE
2383516cbf37STim Bird	bool "Built-in command line overrides boot loader arguments"
2384645e6466SAnders Roxell	depends on CMDLINE_BOOL && CMDLINE != ""
2385a7f7f624SMasahiro Yamada	help
2386516cbf37STim Bird	  Set this option to 'Y' to have the kernel ignore the boot loader
2387516cbf37STim Bird	  command line, and use ONLY the built-in command line.
2388516cbf37STim Bird
2389516cbf37STim Bird	  This is used to work around broken boot loaders.  This should
2390516cbf37STim Bird	  be set to 'N' under normal conditions.
2391516cbf37STim Bird
2392a5b9e5a2SAndy Lutomirskiconfig MODIFY_LDT_SYSCALL
2393a5b9e5a2SAndy Lutomirski	bool "Enable the LDT (local descriptor table)" if EXPERT
2394a5b9e5a2SAndy Lutomirski	default y
2395a7f7f624SMasahiro Yamada	help
2396a5b9e5a2SAndy Lutomirski	  Linux can allow user programs to install a per-process x86
2397a5b9e5a2SAndy Lutomirski	  Local Descriptor Table (LDT) using the modify_ldt(2) system
2398a5b9e5a2SAndy Lutomirski	  call.  This is required to run 16-bit or segmented code such as
2399a5b9e5a2SAndy Lutomirski	  DOSEMU or some Wine programs.  It is also used by some very old
2400a5b9e5a2SAndy Lutomirski	  threading libraries.
2401a5b9e5a2SAndy Lutomirski
2402a5b9e5a2SAndy Lutomirski	  Enabling this feature adds a small amount of overhead to
2403a5b9e5a2SAndy Lutomirski	  context switches and increases the low-level kernel attack
2404a5b9e5a2SAndy Lutomirski	  surface.  Disabling it removes the modify_ldt(2) system call.
2405a5b9e5a2SAndy Lutomirski
2406a5b9e5a2SAndy Lutomirski	  Saying 'N' here may make sense for embedded or server kernels.
2407a5b9e5a2SAndy Lutomirski
24083aac3ebeSThomas Gleixnerconfig STRICT_SIGALTSTACK_SIZE
24093aac3ebeSThomas Gleixner	bool "Enforce strict size checking for sigaltstack"
24103aac3ebeSThomas Gleixner	depends on DYNAMIC_SIGFRAME
24113aac3ebeSThomas Gleixner	help
24123aac3ebeSThomas Gleixner	  For historical reasons MINSIGSTKSZ is a constant which became
24133aac3ebeSThomas Gleixner	  already too small with AVX512 support. Add a mechanism to
24143aac3ebeSThomas Gleixner	  enforce strict checking of the sigaltstack size against the
24153aac3ebeSThomas Gleixner	  real size of the FPU frame. This option enables the check
24163aac3ebeSThomas Gleixner	  by default. It can also be controlled via the kernel command
24173aac3ebeSThomas Gleixner	  line option 'strict_sas_size' independent of this config
24183aac3ebeSThomas Gleixner	  switch. Enabling it might break existing applications which
24193aac3ebeSThomas Gleixner	  allocate a too small sigaltstack but 'work' because they
24203aac3ebeSThomas Gleixner	  never get a signal delivered.
24213aac3ebeSThomas Gleixner
24223aac3ebeSThomas Gleixner	  Say 'N' unless you want to really enforce this check.
24233aac3ebeSThomas Gleixner
2424b700e7f0SSeth Jenningssource "kernel/livepatch/Kconfig"
2425b700e7f0SSeth Jennings
2426506f1d07SSam Ravnborgendmenu
2427506f1d07SSam Ravnborg
24283072e413SMichal Hockoconfig ARCH_HAS_ADD_PAGES
24293072e413SMichal Hocko	def_bool y
24305c11f00bSDavid Hildenbrand	depends on ARCH_ENABLE_MEMORY_HOTPLUG
24313072e413SMichal Hocko
2432f91ef222SOscar Salvadorconfig ARCH_MHP_MEMMAP_ON_MEMORY_ENABLE
2433f91ef222SOscar Salvador	def_bool y
2434f91ef222SOscar Salvador
2435e534c7c5SLee Schermerhornconfig USE_PERCPU_NUMA_NODE_ID
2436645a7919STejun Heo	def_bool y
2437e534c7c5SLee Schermerhorn	depends on NUMA
2438e534c7c5SLee Schermerhorn
2439da85f865SBjorn Helgaasmenu "Power management and ACPI options"
2440e279b6c1SSam Ravnborg
2441e279b6c1SSam Ravnborgconfig ARCH_HIBERNATION_HEADER
24423c2362e6SHarvey Harrison	def_bool y
244344556530SZhimin Gu	depends on HIBERNATION
2444e279b6c1SSam Ravnborg
2445e279b6c1SSam Ravnborgsource "kernel/power/Kconfig"
2446e279b6c1SSam Ravnborg
2447e279b6c1SSam Ravnborgsource "drivers/acpi/Kconfig"
2448e279b6c1SSam Ravnborg
2449a6b68076SAndi Kleenconfig X86_APM_BOOT
24506fc108a0SJan Beulich	def_bool y
2451282e5aabSPaul Bolle	depends on APM
2452a6b68076SAndi Kleen
2453e279b6c1SSam Ravnborgmenuconfig APM
2454e279b6c1SSam Ravnborg	tristate "APM (Advanced Power Management) BIOS support"
2455efefa6f6SIngo Molnar	depends on X86_32 && PM_SLEEP
2456a7f7f624SMasahiro Yamada	help
2457e279b6c1SSam Ravnborg	  APM is a BIOS specification for saving power using several different
2458e279b6c1SSam Ravnborg	  techniques. This is mostly useful for battery powered laptops with
2459e279b6c1SSam Ravnborg	  APM compliant BIOSes. If you say Y here, the system time will be
2460e279b6c1SSam Ravnborg	  reset after a RESUME operation, the /proc/apm device will provide
2461e279b6c1SSam Ravnborg	  battery status information, and user-space programs will receive
2462e279b6c1SSam Ravnborg	  notification of APM "events" (e.g. battery status change).
2463e279b6c1SSam Ravnborg
2464e279b6c1SSam Ravnborg	  If you select "Y" here, you can disable actual use of the APM
2465e279b6c1SSam Ravnborg	  BIOS by passing the "apm=off" option to the kernel at boot time.
2466e279b6c1SSam Ravnborg
2467e279b6c1SSam Ravnborg	  Note that the APM support is almost completely disabled for
2468e279b6c1SSam Ravnborg	  machines with more than one CPU.
2469e279b6c1SSam Ravnborg
2470e279b6c1SSam Ravnborg	  In order to use APM, you will need supporting software. For location
2471151f4e2bSMauro Carvalho Chehab	  and more information, read <file:Documentation/power/apm-acpi.rst>
24722dc98fd3SMichael Witten	  and the Battery Powered Linux mini-HOWTO, available from
2473e279b6c1SSam Ravnborg	  <http://www.tldp.org/docs.html#howto>.
2474e279b6c1SSam Ravnborg
2475e279b6c1SSam Ravnborg	  This driver does not spin down disk drives (see the hdparm(8)
2476e279b6c1SSam Ravnborg	  manpage ("man 8 hdparm") for that), and it doesn't turn off
2477e279b6c1SSam Ravnborg	  VESA-compliant "green" monitors.
2478e279b6c1SSam Ravnborg
2479e279b6c1SSam Ravnborg	  This driver does not support the TI 4000M TravelMate and the ACER
2480e279b6c1SSam Ravnborg	  486/DX4/75 because they don't have compliant BIOSes. Many "green"
2481e279b6c1SSam Ravnborg	  desktop machines also don't have compliant BIOSes, and this driver
2482e279b6c1SSam Ravnborg	  may cause those machines to panic during the boot phase.
2483e279b6c1SSam Ravnborg
2484e279b6c1SSam Ravnborg	  Generally, if you don't have a battery in your machine, there isn't
2485e279b6c1SSam Ravnborg	  much point in using this driver and you should say N. If you get
2486e279b6c1SSam Ravnborg	  random kernel OOPSes or reboots that don't seem to be related to
2487e279b6c1SSam Ravnborg	  anything, try disabling/enabling this option (or disabling/enabling
2488e279b6c1SSam Ravnborg	  APM in your BIOS).
2489e279b6c1SSam Ravnborg
2490e279b6c1SSam Ravnborg	  Some other things you should try when experiencing seemingly random,
2491e279b6c1SSam Ravnborg	  "weird" problems:
2492e279b6c1SSam Ravnborg
2493e279b6c1SSam Ravnborg	  1) make sure that you have enough swap space and that it is
2494e279b6c1SSam Ravnborg	  enabled.
2495e279b6c1SSam Ravnborg	  2) pass the "no-hlt" option to the kernel
2496e279b6c1SSam Ravnborg	  3) switch on floating point emulation in the kernel and pass
2497e279b6c1SSam Ravnborg	  the "no387" option to the kernel
2498e279b6c1SSam Ravnborg	  4) pass the "floppy=nodma" option to the kernel
2499e279b6c1SSam Ravnborg	  5) pass the "mem=4M" option to the kernel (thereby disabling
2500e279b6c1SSam Ravnborg	  all but the first 4 MB of RAM)
2501e279b6c1SSam Ravnborg	  6) make sure that the CPU is not over clocked.
2502e279b6c1SSam Ravnborg	  7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/>
2503e279b6c1SSam Ravnborg	  8) disable the cache from your BIOS settings
2504e279b6c1SSam Ravnborg	  9) install a fan for the video card or exchange video RAM
2505e279b6c1SSam Ravnborg	  10) install a better fan for the CPU
2506e279b6c1SSam Ravnborg	  11) exchange RAM chips
2507e279b6c1SSam Ravnborg	  12) exchange the motherboard.
2508e279b6c1SSam Ravnborg
2509e279b6c1SSam Ravnborg	  To compile this driver as a module, choose M here: the
2510e279b6c1SSam Ravnborg	  module will be called apm.
2511e279b6c1SSam Ravnborg
2512e279b6c1SSam Ravnborgif APM
2513e279b6c1SSam Ravnborg
2514e279b6c1SSam Ravnborgconfig APM_IGNORE_USER_SUSPEND
2515e279b6c1SSam Ravnborg	bool "Ignore USER SUSPEND"
2516a7f7f624SMasahiro Yamada	help
2517e279b6c1SSam Ravnborg	  This option will ignore USER SUSPEND requests. On machines with a
2518e279b6c1SSam Ravnborg	  compliant APM BIOS, you want to say N. However, on the NEC Versa M
2519e279b6c1SSam Ravnborg	  series notebooks, it is necessary to say Y because of a BIOS bug.
2520e279b6c1SSam Ravnborg
2521e279b6c1SSam Ravnborgconfig APM_DO_ENABLE
2522e279b6c1SSam Ravnborg	bool "Enable PM at boot time"
2523a7f7f624SMasahiro Yamada	help
2524e279b6c1SSam Ravnborg	  Enable APM features at boot time. From page 36 of the APM BIOS
2525e279b6c1SSam Ravnborg	  specification: "When disabled, the APM BIOS does not automatically
2526e279b6c1SSam Ravnborg	  power manage devices, enter the Standby State, enter the Suspend
2527e279b6c1SSam Ravnborg	  State, or take power saving steps in response to CPU Idle calls."
2528e279b6c1SSam Ravnborg	  This driver will make CPU Idle calls when Linux is idle (unless this
2529e279b6c1SSam Ravnborg	  feature is turned off -- see "Do CPU IDLE calls", below). This
2530e279b6c1SSam Ravnborg	  should always save battery power, but more complicated APM features
2531e279b6c1SSam Ravnborg	  will be dependent on your BIOS implementation. You may need to turn
2532e279b6c1SSam Ravnborg	  this option off if your computer hangs at boot time when using APM
2533e279b6c1SSam Ravnborg	  support, or if it beeps continuously instead of suspending. Turn
2534e279b6c1SSam Ravnborg	  this off if you have a NEC UltraLite Versa 33/C or a Toshiba
2535e279b6c1SSam Ravnborg	  T400CDT. This is off by default since most machines do fine without
2536e279b6c1SSam Ravnborg	  this feature.
2537e279b6c1SSam Ravnborg
2538e279b6c1SSam Ravnborgconfig APM_CPU_IDLE
2539dd8af076SLen Brown	depends on CPU_IDLE
2540e279b6c1SSam Ravnborg	bool "Make CPU Idle calls when idle"
2541a7f7f624SMasahiro Yamada	help
2542e279b6c1SSam Ravnborg	  Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop.
2543e279b6c1SSam Ravnborg	  On some machines, this can activate improved power savings, such as
2544e279b6c1SSam Ravnborg	  a slowed CPU clock rate, when the machine is idle. These idle calls
2545e279b6c1SSam Ravnborg	  are made after the idle loop has run for some length of time (e.g.,
2546e279b6c1SSam Ravnborg	  333 mS). On some machines, this will cause a hang at boot time or
2547e279b6c1SSam Ravnborg	  whenever the CPU becomes idle. (On machines with more than one CPU,
2548e279b6c1SSam Ravnborg	  this option does nothing.)
2549e279b6c1SSam Ravnborg
2550e279b6c1SSam Ravnborgconfig APM_DISPLAY_BLANK
2551e279b6c1SSam Ravnborg	bool "Enable console blanking using APM"
2552a7f7f624SMasahiro Yamada	help
2553e279b6c1SSam Ravnborg	  Enable console blanking using the APM. Some laptops can use this to
2554e279b6c1SSam Ravnborg	  turn off the LCD backlight when the screen blanker of the Linux
2555e279b6c1SSam Ravnborg	  virtual console blanks the screen. Note that this is only used by
2556e279b6c1SSam Ravnborg	  the virtual console screen blanker, and won't turn off the backlight
2557e279b6c1SSam Ravnborg	  when using the X Window system. This also doesn't have anything to
2558e279b6c1SSam Ravnborg	  do with your VESA-compliant power-saving monitor. Further, this
2559e279b6c1SSam Ravnborg	  option doesn't work for all laptops -- it might not turn off your
2560e279b6c1SSam Ravnborg	  backlight at all, or it might print a lot of errors to the console,
2561e279b6c1SSam Ravnborg	  especially if you are using gpm.
2562e279b6c1SSam Ravnborg
2563e279b6c1SSam Ravnborgconfig APM_ALLOW_INTS
2564e279b6c1SSam Ravnborg	bool "Allow interrupts during APM BIOS calls"
2565a7f7f624SMasahiro Yamada	help
2566e279b6c1SSam Ravnborg	  Normally we disable external interrupts while we are making calls to
2567e279b6c1SSam Ravnborg	  the APM BIOS as a measure to lessen the effects of a badly behaving
2568e279b6c1SSam Ravnborg	  BIOS implementation.  The BIOS should reenable interrupts if it
2569e279b6c1SSam Ravnborg	  needs to.  Unfortunately, some BIOSes do not -- especially those in
2570e279b6c1SSam Ravnborg	  many of the newer IBM Thinkpads.  If you experience hangs when you
2571e279b6c1SSam Ravnborg	  suspend, try setting this to Y.  Otherwise, say N.
2572e279b6c1SSam Ravnborg
2573e279b6c1SSam Ravnborgendif # APM
2574e279b6c1SSam Ravnborg
2575bb0a56ecSDave Jonessource "drivers/cpufreq/Kconfig"
2576e279b6c1SSam Ravnborg
2577e279b6c1SSam Ravnborgsource "drivers/cpuidle/Kconfig"
2578e279b6c1SSam Ravnborg
257927471fdbSAndy Henroidsource "drivers/idle/Kconfig"
258027471fdbSAndy Henroid
2581e279b6c1SSam Ravnborgendmenu
2582e279b6c1SSam Ravnborg
2583e279b6c1SSam Ravnborg
2584e279b6c1SSam Ravnborgmenu "Bus options (PCI etc.)"
2585e279b6c1SSam Ravnborg
2586e279b6c1SSam Ravnborgchoice
2587e279b6c1SSam Ravnborg	prompt "PCI access mode"
2588efefa6f6SIngo Molnar	depends on X86_32 && PCI
2589e279b6c1SSam Ravnborg	default PCI_GOANY
2590a7f7f624SMasahiro Yamada	help
2591e279b6c1SSam Ravnborg	  On PCI systems, the BIOS can be used to detect the PCI devices and
2592e279b6c1SSam Ravnborg	  determine their configuration. However, some old PCI motherboards
2593e279b6c1SSam Ravnborg	  have BIOS bugs and may crash if this is done. Also, some embedded
2594e279b6c1SSam Ravnborg	  PCI-based systems don't have any BIOS at all. Linux can also try to
2595e279b6c1SSam Ravnborg	  detect the PCI hardware directly without using the BIOS.
2596e279b6c1SSam Ravnborg
2597e279b6c1SSam Ravnborg	  With this option, you can specify how Linux should detect the
2598e279b6c1SSam Ravnborg	  PCI devices. If you choose "BIOS", the BIOS will be used,
2599e279b6c1SSam Ravnborg	  if you choose "Direct", the BIOS won't be used, and if you
2600e279b6c1SSam Ravnborg	  choose "MMConfig", then PCI Express MMCONFIG will be used.
2601e279b6c1SSam Ravnborg	  If you choose "Any", the kernel will try MMCONFIG, then the
2602e279b6c1SSam Ravnborg	  direct access method and falls back to the BIOS if that doesn't
2603e279b6c1SSam Ravnborg	  work. If unsure, go with the default, which is "Any".
2604e279b6c1SSam Ravnborg
2605e279b6c1SSam Ravnborgconfig PCI_GOBIOS
2606e279b6c1SSam Ravnborg	bool "BIOS"
2607e279b6c1SSam Ravnborg
2608e279b6c1SSam Ravnborgconfig PCI_GOMMCONFIG
2609e279b6c1SSam Ravnborg	bool "MMConfig"
2610e279b6c1SSam Ravnborg
2611e279b6c1SSam Ravnborgconfig PCI_GODIRECT
2612e279b6c1SSam Ravnborg	bool "Direct"
2613e279b6c1SSam Ravnborg
26143ef0e1f8SAndres Salomonconfig PCI_GOOLPC
261576fb6570SDaniel Drake	bool "OLPC XO-1"
26163ef0e1f8SAndres Salomon	depends on OLPC
26173ef0e1f8SAndres Salomon
26182bdd1b03SAndres Salomonconfig PCI_GOANY
26192bdd1b03SAndres Salomon	bool "Any"
26202bdd1b03SAndres Salomon
2621e279b6c1SSam Ravnborgendchoice
2622e279b6c1SSam Ravnborg
2623e279b6c1SSam Ravnborgconfig PCI_BIOS
26243c2362e6SHarvey Harrison	def_bool y
2625efefa6f6SIngo Molnar	depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY)
2626e279b6c1SSam Ravnborg
2627e279b6c1SSam Ravnborg# x86-64 doesn't support PCI BIOS access from long mode so always go direct.
2628e279b6c1SSam Ravnborgconfig PCI_DIRECT
26293c2362e6SHarvey Harrison	def_bool y
26300aba496fSShaohua Li	depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC || PCI_GOMMCONFIG))
2631e279b6c1SSam Ravnborg
2632e279b6c1SSam Ravnborgconfig PCI_MMCONFIG
2633b45c9f36SJan Kiszka	bool "Support mmconfig PCI config space access" if X86_64
2634b45c9f36SJan Kiszka	default y
26354590d98fSAndy Shevchenko	depends on PCI && (ACPI || JAILHOUSE_GUEST)
2636b45c9f36SJan Kiszka	depends on X86_64 || (PCI_GOANY || PCI_GOMMCONFIG)
2637e279b6c1SSam Ravnborg
26383ef0e1f8SAndres Salomonconfig PCI_OLPC
26392bdd1b03SAndres Salomon	def_bool y
26402bdd1b03SAndres Salomon	depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY)
26413ef0e1f8SAndres Salomon
2642b5401a96SAlex Nixonconfig PCI_XEN
2643b5401a96SAlex Nixon	def_bool y
2644b5401a96SAlex Nixon	depends on PCI && XEN
2645b5401a96SAlex Nixon
26468364e1f8SJan Kiszkaconfig MMCONF_FAM10H
26478364e1f8SJan Kiszka	def_bool y
26488364e1f8SJan Kiszka	depends on X86_64 && PCI_MMCONFIG && ACPI
2649e279b6c1SSam Ravnborg
26503f6ea84aSIra W. Snyderconfig PCI_CNB20LE_QUIRK
26516a108a14SDavid Rientjes	bool "Read CNB20LE Host Bridge Windows" if EXPERT
26526ea30386SKees Cook	depends on PCI
26533f6ea84aSIra W. Snyder	help
26543f6ea84aSIra W. Snyder	  Read the PCI windows out of the CNB20LE host bridge. This allows
26553f6ea84aSIra W. Snyder	  PCI hotplug to work on systems with the CNB20LE chipset which do
26563f6ea84aSIra W. Snyder	  not have ACPI.
26573f6ea84aSIra W. Snyder
265864a5fed6SBjorn Helgaas	  There's no public spec for this chipset, and this functionality
265964a5fed6SBjorn Helgaas	  is known to be incomplete.
266064a5fed6SBjorn Helgaas
266164a5fed6SBjorn Helgaas	  You should say N unless you know you need this.
266264a5fed6SBjorn Helgaas
26633a495511SWilliam Breathitt Grayconfig ISA_BUS
266417a2a129SWilliam Breathitt Gray	bool "ISA bus support on modern systems" if EXPERT
26653a495511SWilliam Breathitt Gray	help
266617a2a129SWilliam Breathitt Gray	  Expose ISA bus device drivers and options available for selection and
266717a2a129SWilliam Breathitt Gray	  configuration. Enable this option if your target machine has an ISA
266817a2a129SWilliam Breathitt Gray	  bus. ISA is an older system, displaced by PCI and newer bus
266917a2a129SWilliam Breathitt Gray	  architectures -- if your target machine is modern, it probably does
267017a2a129SWilliam Breathitt Gray	  not have an ISA bus.
26713a495511SWilliam Breathitt Gray
26723a495511SWilliam Breathitt Gray	  If unsure, say N.
26733a495511SWilliam Breathitt Gray
26741c00f016SDavid Rientjes# x86_64 have no ISA slots, but can have ISA-style DMA.
2675e279b6c1SSam Ravnborgconfig ISA_DMA_API
26761c00f016SDavid Rientjes	bool "ISA-style DMA support" if (X86_64 && EXPERT)
26771c00f016SDavid Rientjes	default y
26781c00f016SDavid Rientjes	help
26791c00f016SDavid Rientjes	  Enables ISA-style DMA support for devices requiring such controllers.
26801c00f016SDavid Rientjes	  If unsure, say Y.
2681e279b6c1SSam Ravnborg
268251e68d05SLinus Torvaldsif X86_32
268351e68d05SLinus Torvalds
2684e279b6c1SSam Ravnborgconfig ISA
2685e279b6c1SSam Ravnborg	bool "ISA support"
2686a7f7f624SMasahiro Yamada	help
2687e279b6c1SSam Ravnborg	  Find out whether you have ISA slots on your motherboard.  ISA is the
2688e279b6c1SSam Ravnborg	  name of a bus system, i.e. the way the CPU talks to the other stuff
2689e279b6c1SSam Ravnborg	  inside your box.  Other bus systems are PCI, EISA, MicroChannel
2690e279b6c1SSam Ravnborg	  (MCA) or VESA.  ISA is an older system, now being displaced by PCI;
2691e279b6c1SSam Ravnborg	  newer boards don't support it.  If you have ISA, say Y, otherwise N.
2692e279b6c1SSam Ravnborg
2693e279b6c1SSam Ravnborgconfig SCx200
2694e279b6c1SSam Ravnborg	tristate "NatSemi SCx200 support"
2695a7f7f624SMasahiro Yamada	help
2696e279b6c1SSam Ravnborg	  This provides basic support for National Semiconductor's
2697e279b6c1SSam Ravnborg	  (now AMD's) Geode processors.  The driver probes for the
2698e279b6c1SSam Ravnborg	  PCI-IDs of several on-chip devices, so its a good dependency
2699e279b6c1SSam Ravnborg	  for other scx200_* drivers.
2700e279b6c1SSam Ravnborg
2701e279b6c1SSam Ravnborg	  If compiled as a module, the driver is named scx200.
2702e279b6c1SSam Ravnborg
2703e279b6c1SSam Ravnborgconfig SCx200HR_TIMER
2704e279b6c1SSam Ravnborg	tristate "NatSemi SCx200 27MHz High-Resolution Timer Support"
2705592913ecSJohn Stultz	depends on SCx200
2706e279b6c1SSam Ravnborg	default y
2707a7f7f624SMasahiro Yamada	help
2708e279b6c1SSam Ravnborg	  This driver provides a clocksource built upon the on-chip
2709e279b6c1SSam Ravnborg	  27MHz high-resolution timer.  Its also a workaround for
2710e279b6c1SSam Ravnborg	  NSC Geode SC-1100's buggy TSC, which loses time when the
2711e279b6c1SSam Ravnborg	  processor goes idle (as is done by the scheduler).  The
2712e279b6c1SSam Ravnborg	  other workaround is idle=poll boot option.
2713e279b6c1SSam Ravnborg
27143ef0e1f8SAndres Salomonconfig OLPC
27153ef0e1f8SAndres Salomon	bool "One Laptop Per Child support"
271654008979SThomas Gleixner	depends on !X86_PAE
27173c554946SAndres Salomon	select GPIOLIB
2718dc3119e7SThomas Gleixner	select OF
271945bb1674SDaniel Drake	select OF_PROMTREE
2720b4e51854SGrant Likely	select IRQ_DOMAIN
27210c3d931bSLubomir Rintel	select OLPC_EC
2722a7f7f624SMasahiro Yamada	help
27233ef0e1f8SAndres Salomon	  Add support for detecting the unique features of the OLPC
27243ef0e1f8SAndres Salomon	  XO hardware.
27253ef0e1f8SAndres Salomon
2726a3128588SDaniel Drakeconfig OLPC_XO1_PM
2727a3128588SDaniel Drake	bool "OLPC XO-1 Power Management"
2728fa112cf1SBorislav Petkov	depends on OLPC && MFD_CS5535=y && PM_SLEEP
2729a7f7f624SMasahiro Yamada	help
273097c4cb71SDaniel Drake	  Add support for poweroff and suspend of the OLPC XO-1 laptop.
2731bf1ebf00SDaniel Drake
2732cfee9597SDaniel Drakeconfig OLPC_XO1_RTC
2733cfee9597SDaniel Drake	bool "OLPC XO-1 Real Time Clock"
2734cfee9597SDaniel Drake	depends on OLPC_XO1_PM && RTC_DRV_CMOS
2735a7f7f624SMasahiro Yamada	help
2736cfee9597SDaniel Drake	  Add support for the XO-1 real time clock, which can be used as a
2737cfee9597SDaniel Drake	  programmable wakeup source.
2738cfee9597SDaniel Drake
27397feda8e9SDaniel Drakeconfig OLPC_XO1_SCI
27407feda8e9SDaniel Drake	bool "OLPC XO-1 SCI extras"
274192e830f2SArnd Bergmann	depends on OLPC && OLPC_XO1_PM && GPIO_CS5535=y
2742ed8e47feSRandy Dunlap	depends on INPUT=y
2743d8d01a63SDaniel Drake	select POWER_SUPPLY
2744a7f7f624SMasahiro Yamada	help
27457feda8e9SDaniel Drake	  Add support for SCI-based features of the OLPC XO-1 laptop:
27467bc74b3dSDaniel Drake	   - EC-driven system wakeups
27477feda8e9SDaniel Drake	   - Power button
27487bc74b3dSDaniel Drake	   - Ebook switch
27492cf2baeaSDaniel Drake	   - Lid switch
2750e1040ac6SDaniel Drake	   - AC adapter status updates
2751e1040ac6SDaniel Drake	   - Battery status updates
27527feda8e9SDaniel Drake
2753a0f30f59SDaniel Drakeconfig OLPC_XO15_SCI
2754a0f30f59SDaniel Drake	bool "OLPC XO-1.5 SCI extras"
2755d8d01a63SDaniel Drake	depends on OLPC && ACPI
2756d8d01a63SDaniel Drake	select POWER_SUPPLY
2757a7f7f624SMasahiro Yamada	help
2758a0f30f59SDaniel Drake	  Add support for SCI-based features of the OLPC XO-1.5 laptop:
2759a0f30f59SDaniel Drake	   - EC-driven system wakeups
2760a0f30f59SDaniel Drake	   - AC adapter status updates
2761a0f30f59SDaniel Drake	   - Battery status updates
2762e279b6c1SSam Ravnborg
2763d4f3e350SEd Wildgooseconfig ALIX
2764d4f3e350SEd Wildgoose	bool "PCEngines ALIX System Support (LED setup)"
2765d4f3e350SEd Wildgoose	select GPIOLIB
2766a7f7f624SMasahiro Yamada	help
2767d4f3e350SEd Wildgoose	  This option enables system support for the PCEngines ALIX.
2768d4f3e350SEd Wildgoose	  At present this just sets up LEDs for GPIO control on
2769d4f3e350SEd Wildgoose	  ALIX2/3/6 boards.  However, other system specific setup should
2770d4f3e350SEd Wildgoose	  get added here.
2771d4f3e350SEd Wildgoose
2772d4f3e350SEd Wildgoose	  Note: You must still enable the drivers for GPIO and LED support
2773d4f3e350SEd Wildgoose	  (GPIO_CS5535 & LEDS_GPIO) to actually use the LEDs
2774d4f3e350SEd Wildgoose
2775d4f3e350SEd Wildgoose	  Note: You have to set alix.force=1 for boards with Award BIOS.
2776d4f3e350SEd Wildgoose
2777da4e3302SPhilip Prindevilleconfig NET5501
2778da4e3302SPhilip Prindeville	bool "Soekris Engineering net5501 System Support (LEDS, GPIO, etc)"
2779da4e3302SPhilip Prindeville	select GPIOLIB
2780a7f7f624SMasahiro Yamada	help
2781da4e3302SPhilip Prindeville	  This option enables system support for the Soekris Engineering net5501.
2782da4e3302SPhilip Prindeville
27833197059aSPhilip A. Prindevilleconfig GEOS
27843197059aSPhilip A. Prindeville	bool "Traverse Technologies GEOS System Support (LEDS, GPIO, etc)"
27853197059aSPhilip A. Prindeville	select GPIOLIB
27863197059aSPhilip A. Prindeville	depends on DMI
2787a7f7f624SMasahiro Yamada	help
27883197059aSPhilip A. Prindeville	  This option enables system support for the Traverse Technologies GEOS.
27893197059aSPhilip A. Prindeville
27907d029125SVivien Didelotconfig TS5500
27917d029125SVivien Didelot	bool "Technologic Systems TS-5500 platform support"
27927d029125SVivien Didelot	depends on MELAN
27937d029125SVivien Didelot	select CHECK_SIGNATURE
27947d029125SVivien Didelot	select NEW_LEDS
27957d029125SVivien Didelot	select LEDS_CLASS
2796a7f7f624SMasahiro Yamada	help
27977d029125SVivien Didelot	  This option enables system support for the Technologic Systems TS-5500.
27987d029125SVivien Didelot
2799e279b6c1SSam Ravnborgendif # X86_32
2800e279b6c1SSam Ravnborg
280123ac4ae8SAndreas Herrmannconfig AMD_NB
2802e279b6c1SSam Ravnborg	def_bool y
28030e152cd7SBorislav Petkov	depends on CPU_SUP_AMD && PCI
2804e279b6c1SSam Ravnborg
2805e279b6c1SSam Ravnborgendmenu
2806e279b6c1SSam Ravnborg
2807e279b6c1SSam Ravnborg
28081572497cSChristoph Hellwigmenu "Binary Emulations"
2809e279b6c1SSam Ravnborg
2810e279b6c1SSam Ravnborgconfig IA32_EMULATION
2811e279b6c1SSam Ravnborg	bool "IA32 Emulation"
2812e279b6c1SSam Ravnborg	depends on X86_64
281339f88911SIngo Molnar	select ARCH_WANT_OLD_COMPAT_IPC
2814d1603990SRandy Dunlap	select BINFMT_ELF
281539f88911SIngo Molnar	select COMPAT_OLD_SIGACTION
2816a7f7f624SMasahiro Yamada	help
28175fd92e65SH. J. Lu	  Include code to run legacy 32-bit programs under a
28185fd92e65SH. J. Lu	  64-bit kernel. You should likely turn this on, unless you're
28195fd92e65SH. J. Lu	  100% sure that you don't have any 32-bit programs left.
2820e279b6c1SSam Ravnborg
2821e279b6c1SSam Ravnborgconfig IA32_AOUT
2822e279b6c1SSam Ravnborg	tristate "IA32 a.out support"
28236b213e1bSDavid Woodhouse	depends on IA32_EMULATION
2824eac61655SBorislav Petkov	depends on BROKEN
2825a7f7f624SMasahiro Yamada	help
2826e279b6c1SSam Ravnborg	  Support old a.out binaries in the 32bit emulation.
2827e279b6c1SSam Ravnborg
28280bf62763SH. Peter Anvinconfig X86_X32
28296ea30386SKees Cook	bool "x32 ABI for 64-bit mode"
28309b54050bSBrian Gerst	depends on X86_64
2831a7f7f624SMasahiro Yamada	help
28325fd92e65SH. J. Lu	  Include code to run binaries for the x32 native 32-bit ABI
28335fd92e65SH. J. Lu	  for 64-bit processors.  An x32 process gets access to the
28345fd92e65SH. J. Lu	  full 64-bit register file and wide data path while leaving
28355fd92e65SH. J. Lu	  pointers at 32 bits for smaller memory footprint.
28365fd92e65SH. J. Lu
28375fd92e65SH. J. Lu	  You will need a recent binutils (2.22 or later) with
28385fd92e65SH. J. Lu	  elf32_x86_64 support enabled to compile a kernel with this
28395fd92e65SH. J. Lu	  option set.
28405fd92e65SH. J. Lu
2841953fee1dSIngo Molnarconfig COMPAT_32
2842953fee1dSIngo Molnar	def_bool y
2843953fee1dSIngo Molnar	depends on IA32_EMULATION || X86_32
2844953fee1dSIngo Molnar	select HAVE_UID16
2845953fee1dSIngo Molnar	select OLD_SIGSUSPEND3
2846953fee1dSIngo Molnar
2847e279b6c1SSam Ravnborgconfig COMPAT
28483c2362e6SHarvey Harrison	def_bool y
28490bf62763SH. Peter Anvin	depends on IA32_EMULATION || X86_X32
2850e279b6c1SSam Ravnborg
28513120e25eSJan Beulichif COMPAT
2852e279b6c1SSam Ravnborgconfig COMPAT_FOR_U64_ALIGNMENT
28533120e25eSJan Beulich	def_bool y
2854e279b6c1SSam Ravnborg
2855e279b6c1SSam Ravnborgconfig SYSVIPC_COMPAT
28563c2362e6SHarvey Harrison	def_bool y
28573120e25eSJan Beulich	depends on SYSVIPC
28583120e25eSJan Beulichendif
2859ee009e4aSDavid Howells
2860e279b6c1SSam Ravnborgendmenu
2861e279b6c1SSam Ravnborg
2862e279b6c1SSam Ravnborg
2863e5beae16SKeith Packardconfig HAVE_ATOMIC_IOMAP
2864e5beae16SKeith Packard	def_bool y
2865e5beae16SKeith Packard	depends on X86_32
2866e5beae16SKeith Packard
2867edf88417SAvi Kivitysource "arch/x86/kvm/Kconfig"
28685e8ebd84SJason A. Donenfeld
28695e8ebd84SJason A. Donenfeldsource "arch/x86/Kconfig.assembler"
2870